net/core/dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      NET3    Protocol independent device support routines.
   4  *
   5  *      Derived from the non IP parts of dev.c 1.0.19
   6  *              Authors:        Ross Biro
   7  *                              Fred N. van Kempen, <[email protected]>
   8  *                              Mark Evans, <[email protected]>
   9  *
  10  *      Additional Authors:
  11  *              Florian la Roche <[email protected]>
  12  *              Alan Cox <[email protected]>
  13  *              David Hinds <[email protected]>
  14  *              Alexey Kuznetsov <[email protected]>
  15  *              Adam Sulmicki <[email protected]>
  16  *              Pekka Riikonen <[email protected]>
  17  *
  18  *      Changes:
  19  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
  20  *                                      to 2 if register_netdev gets called
  21  *                                      before net_dev_init & also removed a
  22  *                                      few lines of code in the process.
  23  *              Alan Cox        :       device private ioctl copies fields back.
  24  *              Alan Cox        :       Transmit queue code does relevant
  25  *                                      stunts to keep the queue safe.
  26  *              Alan Cox        :       Fixed double lock.
  27  *              Alan Cox        :       Fixed promisc NULL pointer trap
  28  *              ????????        :       Support the full private ioctl range
  29  *              Alan Cox        :       Moved ioctl permission check into
  30  *                                      drivers
  31  *              Tim Kordas      :       SIOCADDMULTI/SIOCDELMULTI
  32  *              Alan Cox        :       100 backlog just doesn't cut it when
  33  *                                      you start doing multicast video 8)
  34  *              Alan Cox        :       Rewrote net_bh and list manager.
  35  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
  36  *              Alan Cox        :       Took out transmit every packet pass
  37  *                                      Saved a few bytes in the ioctl handler
  38  *              Alan Cox        :       Network driver sets packet type before
  39  *                                      calling netif_rx. Saves a function
  40  *                                      call a packet.
  41  *              Alan Cox        :       Hashed net_bh()
  42  *              Richard Kooijman:       Timestamp fixes.
  43  *              Alan Cox        :       Wrong field in SIOCGIFDSTADDR
  44  *              Alan Cox        :       Device lock protection.
  45  *              Alan Cox        :       Fixed nasty side effect of device close
  46  *                                      changes.
  47  *              Rudi Cilibrasi  :       Pass the right thing to
  48  *                                      set_mac_address()
  49  *              Dave Miller     :       32bit quantity for the device lock to
  50  *                                      make it work out on a Sparc.
  51  *              Bjorn Ekwall    :       Added KERNELD hack.
  52  *              Alan Cox        :       Cleaned up the backlog initialise.
  53  *              Craig Metz      :       SIOCGIFCONF fix if space for under
  54  *                                      1 device.
  55  *          Thomas Bogendoerfer :       Return ENODEV for dev_open, if there
  56  *                                      is no device open function.
  57  *              Andi Kleen      :       Fix error reporting for SIOCGIFCONF
  58  *          Michael Chastain    :       Fix signed/unsigned for SIOCGIFCONF
  59  *              Cyrus Durgin    :       Cleaned for KMOD
  60  *              Adam Sulmicki   :       Bug Fix : Network Device Unload
  61  *                                      A network device unload needs to purge
  62  *                                      the backlog queue.
  63  *      Paul Rusty Russell      :       SIOCSIFNAME
  64  *              Pekka Riikonen  :       Netdev boot-time settings code
  65  *              Andrew Morton   :       Make unregister_netdevice wait
  66  *                                      indefinitely on dev->refcnt
  67  *              J Hadi Salim    :       - Backlog queue sampling
  68  *                                      - netif_rx() feedback
  69  */
  70
  71 #include <linux/uaccess.h>
  72 #include <linux/bitops.h>
  73 #include <linux/capability.h>
  74 #include <linux/cpu.h>
  75 #include <linux/types.h>
  76 #include <linux/kernel.h>
  77 #include <linux/hash.h>
  78 #include <linux/slab.h>
  79 #include <linux/sched.h>
  80 #include <linux/sched/mm.h>
  81 #include <linux/mutex.h>
  82 #include <linux/rwsem.h>
  83 #include <linux/string.h>
  84 #include <linux/mm.h>
  85 #include <linux/socket.h>
  86 #include <linux/sockios.h>
  87 #include <linux/errno.h>
  88 #include <linux/interrupt.h>
  89 #include <linux/if_ether.h>
  90 #include <linux/netdevice.h>
  91 #include <linux/etherdevice.h>
  92 #include <linux/ethtool.h>
  93 #include <linux/skbuff.h>
  94 #include <linux/kthread.h>
  95 #include <linux/bpf.h>
  96 #include <linux/bpf_trace.h>
  97 #include <net/net_namespace.h>
  98 #include <net/sock.h>
  99 #include <net/busy_poll.h>
 100 #include <linux/rtnetlink.h>
 101 #include <linux/stat.h>
 102 #include <net/dsa.h>
 103 #include <net/dst.h>
 104 #include <net/dst_metadata.h>
 105 #include <net/gro.h>
 106 #include <net/pkt_sched.h>
 107 #include <net/pkt_cls.h>
 108 #include <net/checksum.h>
 109 #include <net/xfrm.h>
 110 #include <linux/highmem.h>
 111 #include <linux/init.h>
 112 #include <linux/module.h>
 113 #include <linux/netpoll.h>
 114 #include <linux/rcupdate.h>
 115 #include <linux/delay.h>
 116 #include <net/iw_handler.h>
 117 #include <asm/current.h>
 118 #include <linux/audit.h>
 119 #include <linux/dmaengine.h>
 120 #include <linux/err.h>
 121 #include <linux/ctype.h>
 122 #include <linux/if_arp.h>
 123 #include <linux/if_vlan.h>
 124 #include <linux/ip.h>
 125 #include <net/ip.h>
 126 #include <net/mpls.h>
 127 #include <linux/ipv6.h>
 128 #include <linux/in.h>
 129 #include <linux/jhash.h>
 130 #include <linux/random.h>
 131 #include <trace/events/napi.h>
 132 #include <trace/events/net.h>
 133 #include <trace/events/skb.h>
 134 #include <trace/events/qdisc.h>
 135 #include <linux/inetdevice.h>
 136 #include <linux/cpu_rmap.h>
 137 #include <linux/static_key.h>
 138 #include <linux/hashtable.h>
 139 #include <linux/vmalloc.h>
 140 #include <linux/if_macvlan.h>
 141 #include <linux/errqueue.h>
 142 #include <linux/hrtimer.h>
 143 #include <linux/netfilter_netdev.h>
 144 #include <linux/crash_dump.h>
 145 #include <linux/sctp.h>
 146 #include <net/udp_tunnel.h>
 147 #include <linux/net_namespace.h>
 148 #include <linux/indirect_call_wrapper.h>
 149 #include <net/devlink.h>
 150 #include <linux/pm_runtime.h>
 151 #include <linux/prandom.h>
 152 #include <linux/once_lite.h>
 153
 154 #include "dev.h"
 155 #include "net-sysfs.h"
 156
 157
 158 static DEFINE_SPINLOCK(ptype_lock);
 159 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
 160 struct list_head ptype_all __read_mostly;       /* Taps */
 161
 162 static int netif_rx_internal(struct sk_buff *skb);
 163 static int call_netdevice_notifiers_info(unsigned long val,
 164                                          struct netdev_notifier_info *info);
 165 static int call_netdevice_notifiers_extack(unsigned long val,
 166                                            struct net_device *dev,
 167                                            struct netlink_ext_ack *extack);
 168 static struct napi_struct *napi_by_id(unsigned int napi_id);
 169
 170 /*
 171  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
 172  * semaphore.
 173  *
 174  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
 175  *
 176  * Writers must hold the rtnl semaphore while they loop through the
 177  * dev_base_head list, and hold dev_base_lock for writing when they do the
 178  * actual updates.  This allows pure readers to access the list even
 179  * while a writer is preparing to update it.
 180  *
 181  * To put it another way, dev_base_lock is held for writing only to
 182  * protect against pure readers; the rtnl semaphore provides the
 183  * protection against other writers.
 184  *
 185  * See, for example usages, register_netdevice() and
 186  * unregister_netdevice(), which must be called with the rtnl
 187  * semaphore held.
 188  */
 189 DEFINE_RWLOCK(dev_base_lock);
 190 EXPORT_SYMBOL(dev_base_lock);
 191
 192 static DEFINE_MUTEX(ifalias_mutex);
 193
 194 /* protects napi_hash addition/deletion and napi_gen_id */
 195 static DEFINE_SPINLOCK(napi_hash_lock);
 196
 197 static unsigned int napi_gen_id = NR_CPUS;
 198 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
 199
 200 static DECLARE_RWSEM(devnet_rename_sem);
 201
 202 static inline void dev_base_seq_inc(struct net *net)
 203 {
 204         while (++net->dev_base_seq == 0)
 205                 ;
 206 }
 207
 208 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
 209 {
 210         unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
 211
 212         return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
 213 }
 214
 215 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
 216 {
 217         return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
 218 }
 219
 220 static inline void rps_lock_irqsave(struct softnet_data *sd,
 221                                     unsigned long *flags)
 222 {
 223         if (IS_ENABLED(CONFIG_RPS))
 224                 spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
 225         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 226                 local_irq_save(*flags);
 227 }
 228
 229 static inline void rps_lock_irq_disable(struct softnet_data *sd)
 230 {
 231         if (IS_ENABLED(CONFIG_RPS))
 232                 spin_lock_irq(&sd->input_pkt_queue.lock);
 233         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 234                 local_irq_disable();
 235 }
 236
 237 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
 238                                           unsigned long *flags)
 239 {
 240         if (IS_ENABLED(CONFIG_RPS))
 241                 spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
 242         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 243                 local_irq_restore(*flags);
 244 }
 245
 246 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
 247 {
 248         if (IS_ENABLED(CONFIG_RPS))
 249                 spin_unlock_irq(&sd->input_pkt_queue.lock);
 250         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 251                 local_irq_enable();
 252 }
 253
 254 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
 255                                                        const char *name)
 256 {
 257         struct netdev_name_node *name_node;
 258
 259         name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
 260         if (!name_node)
 261                 return NULL;
 262         INIT_HLIST_NODE(&name_node->hlist);
 263         name_node->dev = dev;
 264         name_node->name = name;
 265         return name_node;
 266 }
 267
 268 static struct netdev_name_node *
 269 netdev_name_node_head_alloc(struct net_device *dev)
 270 {
 271         struct netdev_name_node *name_node;
 272
 273         name_node = netdev_name_node_alloc(dev, dev->name);
 274         if (!name_node)
 275                 return NULL;
 276         INIT_LIST_HEAD(&name_node->list);
 277         return name_node;
 278 }
 279
 280 static void netdev_name_node_free(struct netdev_name_node *name_node)
 281 {
 282         kfree(name_node);
 283 }
 284
 285 static void netdev_name_node_add(struct net *net,
 286                                  struct netdev_name_node *name_node)
 287 {
 288         hlist_add_head_rcu(&name_node->hlist,
 289                            dev_name_hash(net, name_node->name));
 290 }
 291
 292 static void netdev_name_node_del(struct netdev_name_node *name_node)
 293 {
 294         hlist_del_rcu(&name_node->hlist);
 295 }
 296
 297 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
 298                                                         const char *name)
 299 {
 300         struct hlist_head *head = dev_name_hash(net, name);
 301         struct netdev_name_node *name_node;
 302
 303         hlist_for_each_entry(name_node, head, hlist)
 304                 if (!strcmp(name_node->name, name))
 305                         return name_node;
 306         return NULL;
 307 }
 308
 309 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
 310                                                             const char *name)
 311 {
 312         struct hlist_head *head = dev_name_hash(net, name);
 313         struct netdev_name_node *name_node;
 314
 315         hlist_for_each_entry_rcu(name_node, head, hlist)
 316                 if (!strcmp(name_node->name, name))
 317                         return name_node;
 318         return NULL;
 319 }
 320
 321 bool netdev_name_in_use(struct net *net, const char *name)
 322 {
 323         return netdev_name_node_lookup(net, name);
 324 }
 325 EXPORT_SYMBOL(netdev_name_in_use);
 326
 327 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
 328 {
 329         struct netdev_name_node *name_node;
 330         struct net *net = dev_net(dev);
 331
 332         name_node = netdev_name_node_lookup(net, name);
 333         if (name_node)
 334                 return -EEXIST;
 335         name_node = netdev_name_node_alloc(dev, name);
 336         if (!name_node)
 337                 return -ENOMEM;
 338         netdev_name_node_add(net, name_node);
 339         /* The node that holds dev->name acts as a head of per-device list. */
 340         list_add_tail(&name_node->list, &dev->name_node->list);
 341
 342         return 0;
 343 }
 344
 345 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
 346 {
 347         list_del(&name_node->list);
 348         netdev_name_node_del(name_node);
 349         kfree(name_node->name);
 350         netdev_name_node_free(name_node);
 351 }
 352
 353 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
 354 {
 355         struct netdev_name_node *name_node;
 356         struct net *net = dev_net(dev);
 357
 358         name_node = netdev_name_node_lookup(net, name);
 359         if (!name_node)
 360                 return -ENOENT;
 361         /* lookup might have found our primary name or a name belonging
 362          * to another device.
 363          */
 364         if (name_node == dev->name_node || name_node->dev != dev)
 365                 return -EINVAL;
 366
 367         __netdev_name_node_alt_destroy(name_node);
 368
 369         return 0;
 370 }
 371
 372 static void netdev_name_node_alt_flush(struct net_device *dev)
 373 {
 374         struct netdev_name_node *name_node, *tmp;
 375
 376         list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
 377                 __netdev_name_node_alt_destroy(name_node);
 378 }
 379
 380 /* Device list insertion */
 381 static void list_netdevice(struct net_device *dev)
 382 {
 383         struct net *net = dev_net(dev);
 384
 385         ASSERT_RTNL();
 386
 387         write_lock(&dev_base_lock);
 388         list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
 389         netdev_name_node_add(net, dev->name_node);
 390         hlist_add_head_rcu(&dev->index_hlist,
 391                            dev_index_hash(net, dev->ifindex));
 392         write_unlock(&dev_base_lock);
 393
 394         dev_base_seq_inc(net);
 395 }
 396
 397 /* Device list removal
 398  * caller must respect a RCU grace period before freeing/reusing dev
 399  */
 400 static void unlist_netdevice(struct net_device *dev)
 401 {
 402         ASSERT_RTNL();
 403
 404         /* Unlink dev from the device chain */
 405         write_lock(&dev_base_lock);
 406         list_del_rcu(&dev->dev_list);
 407         netdev_name_node_del(dev->name_node);
 408         hlist_del_rcu(&dev->index_hlist);
 409         write_unlock(&dev_base_lock);
 410
 411         dev_base_seq_inc(dev_net(dev));
 412 }
 413
 414 /*
 415  *      Our notifier list
 416  */
 417
 418 static RAW_NOTIFIER_HEAD(netdev_chain);
 419
 420 /*
 421  *      Device drivers call our routines to queue packets here. We empty the
 422  *      queue in the local softnet handler.
 423  */
 424
 425 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
 426 EXPORT_PER_CPU_SYMBOL(softnet_data);
 427
 428 #ifdef CONFIG_LOCKDEP
 429 /*
 430  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
 431  * according to dev->type
 432  */
 433 static const unsigned short netdev_lock_type[] = {
 434          ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
 435          ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
 436          ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
 437          ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
 438          ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
 439          ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
 440          ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
 441          ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
 442          ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
 443          ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
 444          ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
 445          ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
 446          ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
 447          ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
 448          ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
 449
 450 static const char *const netdev_lock_name[] = {
 451         "_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
 452         "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
 453         "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
 454         "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
 455         "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
 456         "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
 457         "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
 458         "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
 459         "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
 460         "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
 461         "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
 462         "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
 463         "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
 464         "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
 465         "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
 466
 467 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
 468 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
 469
 470 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
 471 {
 472         int i;
 473
 474         for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
 475                 if (netdev_lock_type[i] == dev_type)
 476                         return i;
 477         /* the last key is used by default */
 478         return ARRAY_SIZE(netdev_lock_type) - 1;
 479 }
 480
 481 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
 482                                                  unsigned short dev_type)
 483 {
 484         int i;
 485
 486         i = netdev_lock_pos(dev_type);
 487         lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
 488                                    netdev_lock_name[i]);
 489 }
 490
 491 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 492 {
 493         int i;
 494
 495         i = netdev_lock_pos(dev->type);
 496         lockdep_set_class_and_name(&dev->addr_list_lock,
 497                                    &netdev_addr_lock_key[i],
 498                                    netdev_lock_name[i]);
 499 }
 500 #else
 501 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
 502                                                  unsigned short dev_type)
 503 {
 504 }
 505
 506 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 507 {
 508 }
 509 #endif
 510
 511 /*******************************************************************************
 512  *
 513  *              Protocol management and registration routines
 514  *
 515  *******************************************************************************/
 516
 517
 518 /*
 519  *      Add a protocol ID to the list. Now that the input handler is
 520  *      smarter we can dispense with all the messy stuff that used to be
 521  *      here.
 522  *
 523  *      BEWARE!!! Protocol handlers, mangling input packets,
 524  *      MUST BE last in hash buckets and checking protocol handlers
 525  *      MUST start from promiscuous ptype_all chain in net_bh.
 526  *      It is true now, do not change it.
 527  *      Explanation follows: if protocol handler, mangling packet, will
 528  *      be the first on list, it is not able to sense, that packet
 529  *      is cloned and should be copied-on-write, so that it will
 530  *      change it and subsequent readers will get broken packet.
 531  *                                                      --ANK (980803)
 532  */
 533
 534 static inline struct list_head *ptype_head(const struct packet_type *pt)
 535 {
 536         if (pt->type == htons(ETH_P_ALL))
 537                 return pt->dev ? &pt->dev->ptype_all : &ptype_all;
 538         else
 539                 return pt->dev ? &pt->dev->ptype_specific :
 540                                  &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
 541 }
 542
 543 /**
 544  *      dev_add_pack - add packet handler
 545  *      @pt: packet type declaration
 546  *
 547  *      Add a protocol handler to the networking stack. The passed &packet_type
 548  *      is linked into kernel lists and may not be freed until it has been
 549  *      removed from the kernel lists.
 550  *
 551  *      This call does not sleep therefore it can not
 552  *      guarantee all CPU's that are in middle of receiving packets
 553  *      will see the new packet type (until the next received packet).
 554  */
 555
 556 void dev_add_pack(struct packet_type *pt)
 557 {
 558         struct list_head *head = ptype_head(pt);
 559
 560         spin_lock(&ptype_lock);
 561         list_add_rcu(&pt->list, head);
 562         spin_unlock(&ptype_lock);
 563 }
 564 EXPORT_SYMBOL(dev_add_pack);
 565
 566 /**
 567  *      __dev_remove_pack        - remove packet handler
 568  *      @pt: packet type declaration
 569  *
 570  *      Remove a protocol handler that was previously added to the kernel
 571  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
 572  *      from the kernel lists and can be freed or reused once this function
 573  *      returns.
 574  *
 575  *      The packet type might still be in use by receivers
 576  *      and must not be freed until after all the CPU's have gone
 577  *      through a quiescent state.
 578  */
 579 void __dev_remove_pack(struct packet_type *pt)
 580 {
 581         struct list_head *head = ptype_head(pt);
 582         struct packet_type *pt1;
 583
 584         spin_lock(&ptype_lock);
 585
 586         list_for_each_entry(pt1, head, list) {
 587                 if (pt == pt1) {
 588                         list_del_rcu(&pt->list);
 589                         goto out;
 590                 }
 591         }
 592
 593         pr_warn("dev_remove_pack: %p not found\n", pt);
 594 out:
 595         spin_unlock(&ptype_lock);
 596 }
 597 EXPORT_SYMBOL(__dev_remove_pack);
 598
 599 /**
 600  *      dev_remove_pack  - remove packet handler
 601  *      @pt: packet type declaration
 602  *
 603  *      Remove a protocol handler that was previously added to the kernel
 604  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
 605  *      from the kernel lists and can be freed or reused once this function
 606  *      returns.
 607  *
 608  *      This call sleeps to guarantee that no CPU is looking at the packet
 609  *      type after return.
 610  */
 611 void dev_remove_pack(struct packet_type *pt)
 612 {
 613         __dev_remove_pack(pt);
 614
 615         synchronize_net();
 616 }
 617 EXPORT_SYMBOL(dev_remove_pack);
 618
 619
 620 /*******************************************************************************
 621  *
 622  *                          Device Interface Subroutines
 623  *
 624  *******************************************************************************/
 625
 626 /**
 627  *      dev_get_iflink  - get 'iflink' value of a interface
 628  *      @dev: targeted interface
 629  *
 630  *      Indicates the ifindex the interface is linked to.
 631  *      Physical interfaces have the same 'ifindex' and 'iflink' values.
 632  */
 633
 634 int dev_get_iflink(const struct net_device *dev)
 635 {
 636         if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
 637                 return dev->netdev_ops->ndo_get_iflink(dev);
 638
 639         return dev->ifindex;
 640 }
 641 EXPORT_SYMBOL(dev_get_iflink);
 642
 643 /**
 644  *      dev_fill_metadata_dst - Retrieve tunnel egress information.
 645  *      @dev: targeted interface
 646  *      @skb: The packet.
 647  *
 648  *      For better visibility of tunnel traffic OVS needs to retrieve
 649  *      egress tunnel information for a packet. Following API allows
 650  *      user to get this info.
 651  */
 652 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 653 {
 654         struct ip_tunnel_info *info;
 655
 656         if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
 657                 return -EINVAL;
 658
 659         info = skb_tunnel_info_unclone(skb);
 660         if (!info)
 661                 return -ENOMEM;
 662         if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
 663                 return -EINVAL;
 664
 665         return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
 666 }
 667 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
 668
 669 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
 670 {
 671         int k = stack->num_paths++;
 672
 673         if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
 674                 return NULL;
 675
 676         return &stack->path[k];
 677 }
 678
 679 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
 680                           struct net_device_path_stack *stack)
 681 {
 682         const struct net_device *last_dev;
 683         struct net_device_path_ctx ctx = {
 684                 .dev    = dev,
 685         };
 686         struct net_device_path *path;
 687         int ret = 0;
 688
 689         memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
 690         stack->num_paths = 0;
 691         while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
 692                 last_dev = ctx.dev;
 693                 path = dev_fwd_path(stack);
 694                 if (!path)
 695                         return -1;
 696
 697                 memset(path, 0, sizeof(struct net_device_path));
 698                 ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
 699                 if (ret < 0)
 700                         return -1;
 701
 702                 if (WARN_ON_ONCE(last_dev == ctx.dev))
 703                         return -1;
 704         }
 705
 706         if (!ctx.dev)
 707                 return ret;
 708
 709         path = dev_fwd_path(stack);
 710         if (!path)
 711                 return -1;
 712         path->type = DEV_PATH_ETHERNET;
 713         path->dev = ctx.dev;
 714
 715         return ret;
 716 }
 717 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
 718
 719 /**
 720  *      __dev_get_by_name       - find a device by its name
 721  *      @net: the applicable net namespace
 722  *      @name: name to find
 723  *
 724  *      Find an interface by name. Must be called under RTNL semaphore
 725  *      or @dev_base_lock. If the name is found a pointer to the device
 726  *      is returned. If the name is not found then %NULL is returned. The
 727  *      reference counters are not incremented so the caller must be
 728  *      careful with locks.
 729  */
 730
 731 struct net_device *__dev_get_by_name(struct net *net, const char *name)
 732 {
 733         struct netdev_name_node *node_name;
 734
 735         node_name = netdev_name_node_lookup(net, name);
 736         return node_name ? node_name->dev : NULL;
 737 }
 738 EXPORT_SYMBOL(__dev_get_by_name);
 739
 740 /**
 741  * dev_get_by_name_rcu  - find a device by its name
 742  * @net: the applicable net namespace
 743  * @name: name to find
 744  *
 745  * Find an interface by name.
 746  * If the name is found a pointer to the device is returned.
 747  * If the name is not found then %NULL is returned.
 748  * The reference counters are not incremented so the caller must be
 749  * careful with locks. The caller must hold RCU lock.
 750  */
 751
 752 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
 753 {
 754         struct netdev_name_node *node_name;
 755
 756         node_name = netdev_name_node_lookup_rcu(net, name);
 757         return node_name ? node_name->dev : NULL;
 758 }
 759 EXPORT_SYMBOL(dev_get_by_name_rcu);
 760
 761 /**
 762  *      dev_get_by_name         - find a device by its name
 763  *      @net: the applicable net namespace
 764  *      @name: name to find
 765  *
 766  *      Find an interface by name. This can be called from any
 767  *      context and does its own locking. The returned handle has
 768  *      the usage count incremented and the caller must use dev_put() to
 769  *      release it when it is no longer needed. %NULL is returned if no
 770  *      matching device is found.
 771  */
 772
 773 struct net_device *dev_get_by_name(struct net *net, const char *name)
 774 {
 775         struct net_device *dev;
 776
 777         rcu_read_lock();
 778         dev = dev_get_by_name_rcu(net, name);
 779         dev_hold(dev);
 780         rcu_read_unlock();
 781         return dev;
 782 }
 783 EXPORT_SYMBOL(dev_get_by_name);
 784
 785 /**
 786  *      __dev_get_by_index - find a device by its ifindex
 787  *      @net: the applicable net namespace
 788  *      @ifindex: index of device
 789  *
 790  *      Search for an interface by index. Returns %NULL if the device
 791  *      is not found or a pointer to the device. The device has not
 792  *      had its reference counter increased so the caller must be careful
 793  *      about locking. The caller must hold either the RTNL semaphore
 794  *      or @dev_base_lock.
 795  */
 796
 797 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
 798 {
 799         struct net_device *dev;
 800         struct hlist_head *head = dev_index_hash(net, ifindex);
 801
 802         hlist_for_each_entry(dev, head, index_hlist)
 803                 if (dev->ifindex == ifindex)
 804                         return dev;
 805
 806         return NULL;
 807 }
 808 EXPORT_SYMBOL(__dev_get_by_index);
 809
 810 /**
 811  *      dev_get_by_index_rcu - find a device by its ifindex
 812  *      @net: the applicable net namespace
 813  *      @ifindex: index of device
 814  *
 815  *      Search for an interface by index. Returns %NULL if the device
 816  *      is not found or a pointer to the device. The device has not
 817  *      had its reference counter increased so the caller must be careful
 818  *      about locking. The caller must hold RCU lock.
 819  */
 820
 821 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
 822 {
 823         struct net_device *dev;
 824         struct hlist_head *head = dev_index_hash(net, ifindex);
 825
 826         hlist_for_each_entry_rcu(dev, head, index_hlist)
 827                 if (dev->ifindex == ifindex)
 828                         return dev;
 829
 830         return NULL;
 831 }
 832 EXPORT_SYMBOL(dev_get_by_index_rcu);
 833
 834
 835 /**
 836  *      dev_get_by_index - find a device by its ifindex
 837  *      @net: the applicable net namespace
 838  *      @ifindex: index of device
 839  *
 840  *      Search for an interface by index. Returns NULL if the device
 841  *      is not found or a pointer to the device. The device returned has
 842  *      had a reference added and the pointer is safe until the user calls
 843  *      dev_put to indicate they have finished with it.
 844  */
 845
 846 struct net_device *dev_get_by_index(struct net *net, int ifindex)
 847 {
 848         struct net_device *dev;
 849
 850         rcu_read_lock();
 851         dev = dev_get_by_index_rcu(net, ifindex);
 852         dev_hold(dev);
 853         rcu_read_unlock();
 854         return dev;
 855 }
 856 EXPORT_SYMBOL(dev_get_by_index);
 857
 858 /**
 859  *      dev_get_by_napi_id - find a device by napi_id
 860  *      @napi_id: ID of the NAPI struct
 861  *
 862  *      Search for an interface by NAPI ID. Returns %NULL if the device
 863  *      is not found or a pointer to the device. The device has not had
 864  *      its reference counter increased so the caller must be careful
 865  *      about locking. The caller must hold RCU lock.
 866  */
 867
 868 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
 869 {
 870         struct napi_struct *napi;
 871
 872         WARN_ON_ONCE(!rcu_read_lock_held());
 873
 874         if (napi_id < MIN_NAPI_ID)
 875                 return NULL;
 876
 877         napi = napi_by_id(napi_id);
 878
 879         return napi ? napi->dev : NULL;
 880 }
 881 EXPORT_SYMBOL(dev_get_by_napi_id);
 882
 883 /**
 884  *      netdev_get_name - get a netdevice name, knowing its ifindex.
 885  *      @net: network namespace
 886  *      @name: a pointer to the buffer where the name will be stored.
 887  *      @ifindex: the ifindex of the interface to get the name from.
 888  */
 889 int netdev_get_name(struct net *net, char *name, int ifindex)
 890 {
 891         struct net_device *dev;
 892         int ret;
 893
 894         down_read(&devnet_rename_sem);
 895         rcu_read_lock();
 896
 897         dev = dev_get_by_index_rcu(net, ifindex);
 898         if (!dev) {
 899                 ret = -ENODEV;
 900                 goto out;
 901         }
 902
 903         strcpy(name, dev->name);
 904
 905         ret = 0;
 906 out:
 907         rcu_read_unlock();
 908         up_read(&devnet_rename_sem);
 909         return ret;
 910 }
 911
 912 /**
 913  *      dev_getbyhwaddr_rcu - find a device by its hardware address
 914  *      @net: the applicable net namespace
 915  *      @type: media type of device
 916  *      @ha: hardware address
 917  *
 918  *      Search for an interface by MAC address. Returns NULL if the device
 919  *      is not found or a pointer to the device.
 920  *      The caller must hold RCU or RTNL.
 921  *      The returned device has not had its ref count increased
 922  *      and the caller must therefore be careful about locking
 923  *
 924  */
 925
 926 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
 927                                        const char *ha)
 928 {
 929         struct net_device *dev;
 930
 931         for_each_netdev_rcu(net, dev)
 932                 if (dev->type == type &&
 933                     !memcmp(dev->dev_addr, ha, dev->addr_len))
 934                         return dev;
 935
 936         return NULL;
 937 }
 938 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
 939
 940 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
 941 {
 942         struct net_device *dev, *ret = NULL;
 943
 944         rcu_read_lock();
 945         for_each_netdev_rcu(net, dev)
 946                 if (dev->type == type) {
 947                         dev_hold(dev);
 948                         ret = dev;
 949                         break;
 950                 }
 951         rcu_read_unlock();
 952         return ret;
 953 }
 954 EXPORT_SYMBOL(dev_getfirstbyhwtype);
 955
 956 /**
 957  *      __dev_get_by_flags - find any device with given flags
 958  *      @net: the applicable net namespace
 959  *      @if_flags: IFF_* values
 960  *      @mask: bitmask of bits in if_flags to check
 961  *
 962  *      Search for any interface with the given flags. Returns NULL if a device
 963  *      is not found or a pointer to the device. Must be called inside
 964  *      rtnl_lock(), and result refcount is unchanged.
 965  */
 966
 967 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
 968                                       unsigned short mask)
 969 {
 970         struct net_device *dev, *ret;
 971
 972         ASSERT_RTNL();
 973
 974         ret = NULL;
 975         for_each_netdev(net, dev) {
 976                 if (((dev->flags ^ if_flags) & mask) == 0) {
 977                         ret = dev;
 978                         break;
 979                 }
 980         }
 981         return ret;
 982 }
 983 EXPORT_SYMBOL(__dev_get_by_flags);
 984
 985 /**
 986  *      dev_valid_name - check if name is okay for network device
 987  *      @name: name string
 988  *
 989  *      Network device names need to be valid file names to
 990  *      allow sysfs to work.  We also disallow any kind of
 991  *      whitespace.
 992  */
 993 bool dev_valid_name(const char *name)
 994 {
 995         if (*name == '\0')
 996                 return false;
 997         if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
 998                 return false;
 999         if (!strcmp(name, ".") || !strcmp(name, ".."))
1000                 return false;
1001
1002         while (*name) {
1003                 if (*name == '/' || *name == ':' || isspace(*name))
1004                         return false;
1005                 name++;
1006         }
1007         return true;
1008 }
1009 EXPORT_SYMBOL(dev_valid_name);
1010
1011 /**
1012  *      __dev_alloc_name - allocate a name for a device
1013  *      @net: network namespace to allocate the device name in
1014  *      @name: name format string
1015  *      @buf:  scratch buffer and result name string
1016  *
1017  *      Passed a format string - eg "lt%d" it will try and find a suitable
1018  *      id. It scans list of devices to build up a free map, then chooses
1019  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1020  *      while allocating the name and adding the device in order to avoid
1021  *      duplicates.
1022  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1023  *      Returns the number of the unit assigned or a negative errno code.
1024  */
1025
1026 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1027 {
1028         int i = 0;
1029         const char *p;
1030         const int max_netdevices = 8*PAGE_SIZE;
1031         unsigned long *inuse;
1032         struct net_device *d;
1033
1034         if (!dev_valid_name(name))
1035                 return -EINVAL;
1036
1037         p = strchr(name, '%');
1038         if (p) {
1039                 /*
1040                  * Verify the string as this thing may have come from
1041                  * the user.  There must be either one "%d" and no other "%"
1042                  * characters.
1043                  */
1044                 if (p[1] != 'd' || strchr(p + 2, '%'))
1045                         return -EINVAL;
1046
1047                 /* Use one page as a bit array of possible slots */
1048                 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1049                 if (!inuse)
1050                         return -ENOMEM;
1051
1052                 for_each_netdev(net, d) {
1053                         struct netdev_name_node *name_node;
1054                         list_for_each_entry(name_node, &d->name_node->list, list) {
1055                                 if (!sscanf(name_node->name, name, &i))
1056                                         continue;
1057                                 if (i < 0 || i >= max_netdevices)
1058                                         continue;
1059
1060                                 /*  avoid cases where sscanf is not exact inverse of printf */
1061                                 snprintf(buf, IFNAMSIZ, name, i);
1062                                 if (!strncmp(buf, name_node->name, IFNAMSIZ))
1063                                         __set_bit(i, inuse);
1064                         }
1065                         if (!sscanf(d->name, name, &i))
1066                                 continue;
1067                         if (i < 0 || i >= max_netdevices)
1068                                 continue;
1069
1070                         /*  avoid cases where sscanf is not exact inverse of printf */
1071                         snprintf(buf, IFNAMSIZ, name, i);
1072                         if (!strncmp(buf, d->name, IFNAMSIZ))
1073                                 __set_bit(i, inuse);
1074                 }
1075
1076                 i = find_first_zero_bit(inuse, max_netdevices);
1077                 free_page((unsigned long) inuse);
1078         }
1079
1080         snprintf(buf, IFNAMSIZ, name, i);
1081         if (!netdev_name_in_use(net, buf))
1082                 return i;
1083
1084         /* It is possible to run out of possible slots
1085          * when the name is long and there isn't enough space left
1086          * for the digits, or if all bits are used.
1087          */
1088         return -ENFILE;
1089 }
1090
1091 static int dev_alloc_name_ns(struct net *net,
1092                              struct net_device *dev,
1093                              const char *name)
1094 {
1095         char buf[IFNAMSIZ];
1096         int ret;
1097
1098         BUG_ON(!net);
1099         ret = __dev_alloc_name(net, name, buf);
1100         if (ret >= 0)
1101                 strlcpy(dev->name, buf, IFNAMSIZ);
1102         return ret;
1103 }
1104
1105 /**
1106  *      dev_alloc_name - allocate a name for a device
1107  *      @dev: device
1108  *      @name: name format string
1109  *
1110  *      Passed a format string - eg "lt%d" it will try and find a suitable
1111  *      id. It scans list of devices to build up a free map, then chooses
1112  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1113  *      while allocating the name and adding the device in order to avoid
1114  *      duplicates.
1115  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1116  *      Returns the number of the unit assigned or a negative errno code.
1117  */
1118
1119 int dev_alloc_name(struct net_device *dev, const char *name)
1120 {
1121         return dev_alloc_name_ns(dev_net(dev), dev, name);
1122 }
1123 EXPORT_SYMBOL(dev_alloc_name);
1124
1125 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1126                               const char *name)
1127 {
1128         BUG_ON(!net);
1129
1130         if (!dev_valid_name(name))
1131                 return -EINVAL;
1132
1133         if (strchr(name, '%'))
1134                 return dev_alloc_name_ns(net, dev, name);
1135         else if (netdev_name_in_use(net, name))
1136                 return -EEXIST;
1137         else if (dev->name != name)
1138                 strlcpy(dev->name, name, IFNAMSIZ);
1139
1140         return 0;
1141 }
1142
1143 /**
1144  *      dev_change_name - change name of a device
1145  *      @dev: device
1146  *      @newname: name (or format string) must be at least IFNAMSIZ
1147  *
1148  *      Change name of a device, can pass format strings "eth%d".
1149  *      for wildcarding.
1150  */
1151 int dev_change_name(struct net_device *dev, const char *newname)
1152 {
1153         unsigned char old_assign_type;
1154         char oldname[IFNAMSIZ];
1155         int err = 0;
1156         int ret;
1157         struct net *net;
1158
1159         ASSERT_RTNL();
1160         BUG_ON(!dev_net(dev));
1161
1162         net = dev_net(dev);
1163
1164         /* Some auto-enslaved devices e.g. failover slaves are
1165          * special, as userspace might rename the device after
1166          * the interface had been brought up and running since
1167          * the point kernel initiated auto-enslavement. Allow
1168          * live name change even when these slave devices are
1169          * up and running.
1170          *
1171          * Typically, users of these auto-enslaving devices
1172          * don't actually care about slave name change, as
1173          * they are supposed to operate on master interface
1174          * directly.
1175          */
1176         if (dev->flags & IFF_UP &&
1177             likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK)))
1178                 return -EBUSY;
1179
1180         down_write(&devnet_rename_sem);
1181
1182         if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1183                 up_write(&devnet_rename_sem);
1184                 return 0;
1185         }
1186
1187         memcpy(oldname, dev->name, IFNAMSIZ);
1188
1189         err = dev_get_valid_name(net, dev, newname);
1190         if (err < 0) {
1191                 up_write(&devnet_rename_sem);
1192                 return err;
1193         }
1194
1195         if (oldname[0] && !strchr(oldname, '%'))
1196                 netdev_info(dev, "renamed from %s\n", oldname);
1197
1198         old_assign_type = dev->name_assign_type;
1199         dev->name_assign_type = NET_NAME_RENAMED;
1200
1201 rollback:
1202         ret = device_rename(&dev->dev, dev->name);
1203         if (ret) {
1204                 memcpy(dev->name, oldname, IFNAMSIZ);
1205                 dev->name_assign_type = old_assign_type;
1206                 up_write(&devnet_rename_sem);
1207                 return ret;
1208         }
1209
1210         up_write(&devnet_rename_sem);
1211
1212         netdev_adjacent_rename_links(dev, oldname);
1213
1214         write_lock(&dev_base_lock);
1215         netdev_name_node_del(dev->name_node);
1216         write_unlock(&dev_base_lock);
1217
1218         synchronize_rcu();
1219
1220         write_lock(&dev_base_lock);
1221         netdev_name_node_add(net, dev->name_node);
1222         write_unlock(&dev_base_lock);
1223
1224         ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1225         ret = notifier_to_errno(ret);
1226
1227         if (ret) {
1228                 /* err >= 0 after dev_alloc_name() or stores the first errno */
1229                 if (err >= 0) {
1230                         err = ret;
1231                         down_write(&devnet_rename_sem);
1232                         memcpy(dev->name, oldname, IFNAMSIZ);
1233                         memcpy(oldname, newname, IFNAMSIZ);
1234                         dev->name_assign_type = old_assign_type;
1235                         old_assign_type = NET_NAME_RENAMED;
1236                         goto rollback;
1237                 } else {
1238                         netdev_err(dev, "name change rollback failed: %d\n",
1239                                    ret);
1240                 }
1241         }
1242
1243         return err;
1244 }
1245
1246 /**
1247  *      dev_set_alias - change ifalias of a device
1248  *      @dev: device
1249  *      @alias: name up to IFALIASZ
1250  *      @len: limit of bytes to copy from info
1251  *
1252  *      Set ifalias for a device,
1253  */
1254 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1255 {
1256         struct dev_ifalias *new_alias = NULL;
1257
1258         if (len >= IFALIASZ)
1259                 return -EINVAL;
1260
1261         if (len) {
1262                 new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1263                 if (!new_alias)
1264                         return -ENOMEM;
1265
1266                 memcpy(new_alias->ifalias, alias, len);
1267                 new_alias->ifalias[len] = 0;
1268         }
1269
1270         mutex_lock(&ifalias_mutex);
1271         new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1272                                         mutex_is_locked(&ifalias_mutex));
1273         mutex_unlock(&ifalias_mutex);
1274
1275         if (new_alias)
1276                 kfree_rcu(new_alias, rcuhead);
1277
1278         return len;
1279 }
1280 EXPORT_SYMBOL(dev_set_alias);
1281
1282 /**
1283  *      dev_get_alias - get ifalias of a device
1284  *      @dev: device
1285  *      @name: buffer to store name of ifalias
1286  *      @len: size of buffer
1287  *
1288  *      get ifalias for a device.  Caller must make sure dev cannot go
1289  *      away,  e.g. rcu read lock or own a reference count to device.
1290  */
1291 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1292 {
1293         const struct dev_ifalias *alias;
1294         int ret = 0;
1295
1296         rcu_read_lock();
1297         alias = rcu_dereference(dev->ifalias);
1298         if (alias)
1299                 ret = snprintf(name, len, "%s", alias->ifalias);
1300         rcu_read_unlock();
1301
1302         return ret;
1303 }
1304
1305 /**
1306  *      netdev_features_change - device changes features
1307  *      @dev: device to cause notification
1308  *
1309  *      Called to indicate a device has changed features.
1310  */
1311 void netdev_features_change(struct net_device *dev)
1312 {
1313         call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1314 }
1315 EXPORT_SYMBOL(netdev_features_change);
1316
1317 /**
1318  *      netdev_state_change - device changes state
1319  *      @dev: device to cause notification
1320  *
1321  *      Called to indicate a device has changed state. This function calls
1322  *      the notifier chains for netdev_chain and sends a NEWLINK message
1323  *      to the routing socket.
1324  */
1325 void netdev_state_change(struct net_device *dev)
1326 {
1327         if (dev->flags & IFF_UP) {
1328                 struct netdev_notifier_change_info change_info = {
1329                         .info.dev = dev,
1330                 };
1331
1332                 call_netdevice_notifiers_info(NETDEV_CHANGE,
1333                                               &change_info.info);
1334                 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
1335         }
1336 }
1337 EXPORT_SYMBOL(netdev_state_change);
1338
1339 /**
1340  * __netdev_notify_peers - notify network peers about existence of @dev,
1341  * to be called when rtnl lock is already held.
1342  * @dev: network device
1343  *
1344  * Generate traffic such that interested network peers are aware of
1345  * @dev, such as by generating a gratuitous ARP. This may be used when
1346  * a device wants to inform the rest of the network about some sort of
1347  * reconfiguration such as a failover event or virtual machine
1348  * migration.
1349  */
1350 void __netdev_notify_peers(struct net_device *dev)
1351 {
1352         ASSERT_RTNL();
1353         call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1354         call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1355 }
1356 EXPORT_SYMBOL(__netdev_notify_peers);
1357
1358 /**
1359  * netdev_notify_peers - notify network peers about existence of @dev
1360  * @dev: network device
1361  *
1362  * Generate traffic such that interested network peers are aware of
1363  * @dev, such as by generating a gratuitous ARP. This may be used when
1364  * a device wants to inform the rest of the network about some sort of
1365  * reconfiguration such as a failover event or virtual machine
1366  * migration.
1367  */
1368 void netdev_notify_peers(struct net_device *dev)
1369 {
1370         rtnl_lock();
1371         __netdev_notify_peers(dev);
1372         rtnl_unlock();
1373 }
1374 EXPORT_SYMBOL(netdev_notify_peers);
1375
1376 static int napi_threaded_poll(void *data);
1377
1378 static int napi_kthread_create(struct napi_struct *n)
1379 {
1380         int err = 0;
1381
1382         /* Create and wake up the kthread once to put it in
1383          * TASK_INTERRUPTIBLE mode to avoid the blocked task
1384          * warning and work with loadavg.
1385          */
1386         n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1387                                 n->dev->name, n->napi_id);
1388         if (IS_ERR(n->thread)) {
1389                 err = PTR_ERR(n->thread);
1390                 pr_err("kthread_run failed with err %d\n", err);
1391                 n->thread = NULL;
1392         }
1393
1394         return err;
1395 }
1396
1397 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1398 {
1399         const struct net_device_ops *ops = dev->netdev_ops;
1400         int ret;
1401
1402         ASSERT_RTNL();
1403         dev_addr_check(dev);
1404
1405         if (!netif_device_present(dev)) {
1406                 /* may be detached because parent is runtime-suspended */
1407                 if (dev->dev.parent)
1408                         pm_runtime_resume(dev->dev.parent);
1409                 if (!netif_device_present(dev))
1410                         return -ENODEV;
1411         }
1412
1413         /* Block netpoll from trying to do any rx path servicing.
1414          * If we don't do this there is a chance ndo_poll_controller
1415          * or ndo_poll may be running while we open the device
1416          */
1417         netpoll_poll_disable(dev);
1418
1419         ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1420         ret = notifier_to_errno(ret);
1421         if (ret)
1422                 return ret;
1423
1424         set_bit(__LINK_STATE_START, &dev->state);
1425
1426         if (ops->ndo_validate_addr)
1427                 ret = ops->ndo_validate_addr(dev);
1428
1429         if (!ret && ops->ndo_open)
1430                 ret = ops->ndo_open(dev);
1431
1432         netpoll_poll_enable(dev);
1433
1434         if (ret)
1435                 clear_bit(__LINK_STATE_START, &dev->state);
1436         else {
1437                 dev->flags |= IFF_UP;
1438                 dev_set_rx_mode(dev);
1439                 dev_activate(dev);
1440                 add_device_randomness(dev->dev_addr, dev->addr_len);
1441         }
1442
1443         return ret;
1444 }
1445
1446 /**
1447  *      dev_open        - prepare an interface for use.
1448  *      @dev: device to open
1449  *      @extack: netlink extended ack
1450  *
1451  *      Takes a device from down to up state. The device's private open
1452  *      function is invoked and then the multicast lists are loaded. Finally
1453  *      the device is moved into the up state and a %NETDEV_UP message is
1454  *      sent to the netdev notifier chain.
1455  *
1456  *      Calling this function on an active interface is a nop. On a failure
1457  *      a negative errno code is returned.
1458  */
1459 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1460 {
1461         int ret;
1462
1463         if (dev->flags & IFF_UP)
1464                 return 0;
1465
1466         ret = __dev_open(dev, extack);
1467         if (ret < 0)
1468                 return ret;
1469
1470         rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1471         call_netdevice_notifiers(NETDEV_UP, dev);
1472
1473         return ret;
1474 }
1475 EXPORT_SYMBOL(dev_open);
1476
1477 static void __dev_close_many(struct list_head *head)
1478 {
1479         struct net_device *dev;
1480
1481         ASSERT_RTNL();
1482         might_sleep();
1483
1484         list_for_each_entry(dev, head, close_list) {
1485                 /* Temporarily disable netpoll until the interface is down */
1486                 netpoll_poll_disable(dev);
1487
1488                 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1489
1490                 clear_bit(__LINK_STATE_START, &dev->state);
1491
1492                 /* Synchronize to scheduled poll. We cannot touch poll list, it
1493                  * can be even on different cpu. So just clear netif_running().
1494                  *
1495                  * dev->stop() will invoke napi_disable() on all of it's
1496                  * napi_struct instances on this device.
1497                  */
1498                 smp_mb__after_atomic(); /* Commit netif_running(). */
1499         }
1500
1501         dev_deactivate_many(head);
1502
1503         list_for_each_entry(dev, head, close_list) {
1504                 const struct net_device_ops *ops = dev->netdev_ops;
1505
1506                 /*
1507                  *      Call the device specific close. This cannot fail.
1508                  *      Only if device is UP
1509                  *
1510                  *      We allow it to be called even after a DETACH hot-plug
1511                  *      event.
1512                  */
1513                 if (ops->ndo_stop)
1514                         ops->ndo_stop(dev);
1515
1516                 dev->flags &= ~IFF_UP;
1517                 netpoll_poll_enable(dev);
1518         }
1519 }
1520
1521 static void __dev_close(struct net_device *dev)
1522 {
1523         LIST_HEAD(single);
1524
1525         list_add(&dev->close_list, &single);
1526         __dev_close_many(&single);
1527         list_del(&single);
1528 }
1529
1530 void dev_close_many(struct list_head *head, bool unlink)
1531 {
1532         struct net_device *dev, *tmp;
1533
1534         /* Remove the devices that don't need to be closed */
1535         list_for_each_entry_safe(dev, tmp, head, close_list)
1536                 if (!(dev->flags & IFF_UP))
1537                         list_del_init(&dev->close_list);
1538
1539         __dev_close_many(head);
1540
1541         list_for_each_entry_safe(dev, tmp, head, close_list) {
1542                 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1543                 call_netdevice_notifiers(NETDEV_DOWN, dev);
1544                 if (unlink)
1545                         list_del_init(&dev->close_list);
1546         }
1547 }
1548 EXPORT_SYMBOL(dev_close_many);
1549
1550 /**
1551  *      dev_close - shutdown an interface.
1552  *      @dev: device to shutdown
1553  *
1554  *      This function moves an active device into down state. A
1555  *      %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1556  *      is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1557  *      chain.
1558  */
1559 void dev_close(struct net_device *dev)
1560 {
1561         if (dev->flags & IFF_UP) {
1562                 LIST_HEAD(single);
1563
1564                 list_add(&dev->close_list, &single);
1565                 dev_close_many(&single, true);
1566                 list_del(&single);
1567         }
1568 }
1569 EXPORT_SYMBOL(dev_close);
1570
1571
1572 /**
1573  *      dev_disable_lro - disable Large Receive Offload on a device
1574  *      @dev: device
1575  *
1576  *      Disable Large Receive Offload (LRO) on a net device.  Must be
1577  *      called under RTNL.  This is needed if received packets may be
1578  *      forwarded to another interface.
1579  */
1580 void dev_disable_lro(struct net_device *dev)
1581 {
1582         struct net_device *lower_dev;
1583         struct list_head *iter;
1584
1585         dev->wanted_features &= ~NETIF_F_LRO;
1586         netdev_update_features(dev);
1587
1588         if (unlikely(dev->features & NETIF_F_LRO))
1589                 netdev_WARN(dev, "failed to disable LRO!\n");
1590
1591         netdev_for_each_lower_dev(dev, lower_dev, iter)
1592                 dev_disable_lro(lower_dev);
1593 }
1594 EXPORT_SYMBOL(dev_disable_lro);
1595
1596 /**
1597  *      dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1598  *      @dev: device
1599  *
1600  *      Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1601  *      called under RTNL.  This is needed if Generic XDP is installed on
1602  *      the device.
1603  */
1604 static void dev_disable_gro_hw(struct net_device *dev)
1605 {
1606         dev->wanted_features &= ~NETIF_F_GRO_HW;
1607         netdev_update_features(dev);
1608
1609         if (unlikely(dev->features & NETIF_F_GRO_HW))
1610                 netdev_WARN(dev, "failed to disable GRO_HW!\n");
1611 }
1612
1613 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1614 {
1615 #define N(val)                                          \
1616         case NETDEV_##val:                              \
1617                 return "NETDEV_" __stringify(val);
1618         switch (cmd) {
1619         N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1620         N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1621         N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1622         N(POST_INIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN) N(CHANGEUPPER)
1623         N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
1624         N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
1625         N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1626         N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1627         N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1628         N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1629         N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1630         }
1631 #undef N
1632         return "UNKNOWN_NETDEV_EVENT";
1633 }
1634 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1635
1636 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1637                                    struct net_device *dev)
1638 {
1639         struct netdev_notifier_info info = {
1640                 .dev = dev,
1641         };
1642
1643         return nb->notifier_call(nb, val, &info);
1644 }
1645
1646 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1647                                              struct net_device *dev)
1648 {
1649         int err;
1650
1651         err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1652         err = notifier_to_errno(err);
1653         if (err)
1654                 return err;
1655
1656         if (!(dev->flags & IFF_UP))
1657                 return 0;
1658
1659         call_netdevice_notifier(nb, NETDEV_UP, dev);
1660         return 0;
1661 }
1662
1663 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1664                                                 struct net_device *dev)
1665 {
1666         if (dev->flags & IFF_UP) {
1667                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1668                                         dev);
1669                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1670         }
1671         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1672 }
1673
1674 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1675                                                  struct net *net)
1676 {
1677         struct net_device *dev;
1678         int err;
1679
1680         for_each_netdev(net, dev) {
1681                 err = call_netdevice_register_notifiers(nb, dev);
1682                 if (err)
1683                         goto rollback;
1684         }
1685         return 0;
1686
1687 rollback:
1688         for_each_netdev_continue_reverse(net, dev)
1689                 call_netdevice_unregister_notifiers(nb, dev);
1690         return err;
1691 }
1692
1693 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1694                                                     struct net *net)
1695 {
1696         struct net_device *dev;
1697
1698         for_each_netdev(net, dev)
1699                 call_netdevice_unregister_notifiers(nb, dev);
1700 }
1701
1702 static int dev_boot_phase = 1;
1703
1704 /**
1705  * register_netdevice_notifier - register a network notifier block
1706  * @nb: notifier
1707  *
1708  * Register a notifier to be called when network device events occur.
1709  * The notifier passed is linked into the kernel structures and must
1710  * not be reused until it has been unregistered. A negative errno code
1711  * is returned on a failure.
1712  *
1713  * When registered all registration and up events are replayed
1714  * to the new notifier to allow device to have a race free
1715  * view of the network device list.
1716  */
1717
1718 int register_netdevice_notifier(struct notifier_block *nb)
1719 {
1720         struct net *net;
1721         int err;
1722
1723         /* Close race with setup_net() and cleanup_net() */
1724         down_write(&pernet_ops_rwsem);
1725         rtnl_lock();
1726         err = raw_notifier_chain_register(&netdev_chain, nb);
1727         if (err)
1728                 goto unlock;
1729         if (dev_boot_phase)
1730                 goto unlock;
1731         for_each_net(net) {
1732                 err = call_netdevice_register_net_notifiers(nb, net);
1733                 if (err)
1734                         goto rollback;
1735         }
1736
1737 unlock:
1738         rtnl_unlock();
1739         up_write(&pernet_ops_rwsem);
1740         return err;
1741
1742 rollback:
1743         for_each_net_continue_reverse(net)
1744                 call_netdevice_unregister_net_notifiers(nb, net);
1745
1746         raw_notifier_chain_unregister(&netdev_chain, nb);
1747         goto unlock;
1748 }
1749 EXPORT_SYMBOL(register_netdevice_notifier);
1750
1751 /**
1752  * unregister_netdevice_notifier - unregister a network notifier block
1753  * @nb: notifier
1754  *
1755  * Unregister a notifier previously registered by
1756  * register_netdevice_notifier(). The notifier is unlinked into the
1757  * kernel structures and may then be reused. A negative errno code
1758  * is returned on a failure.
1759  *
1760  * After unregistering unregister and down device events are synthesized
1761  * for all devices on the device list to the removed notifier to remove
1762  * the need for special case cleanup code.
1763  */
1764
1765 int unregister_netdevice_notifier(struct notifier_block *nb)
1766 {
1767         struct net *net;
1768         int err;
1769
1770         /* Close race with setup_net() and cleanup_net() */
1771         down_write(&pernet_ops_rwsem);
1772         rtnl_lock();
1773         err = raw_notifier_chain_unregister(&netdev_chain, nb);
1774         if (err)
1775                 goto unlock;
1776
1777         for_each_net(net)
1778                 call_netdevice_unregister_net_notifiers(nb, net);
1779
1780 unlock:
1781         rtnl_unlock();
1782         up_write(&pernet_ops_rwsem);
1783         return err;
1784 }
1785 EXPORT_SYMBOL(unregister_netdevice_notifier);
1786
1787 static int __register_netdevice_notifier_net(struct net *net,
1788                                              struct notifier_block *nb,
1789                                              bool ignore_call_fail)
1790 {
1791         int err;
1792
1793         err = raw_notifier_chain_register(&net->netdev_chain, nb);
1794         if (err)
1795                 return err;
1796         if (dev_boot_phase)
1797                 return 0;
1798
1799         err = call_netdevice_register_net_notifiers(nb, net);
1800         if (err && !ignore_call_fail)
1801                 goto chain_unregister;
1802
1803         return 0;
1804
1805 chain_unregister:
1806         raw_notifier_chain_unregister(&net->netdev_chain, nb);
1807         return err;
1808 }
1809
1810 static int __unregister_netdevice_notifier_net(struct net *net,
1811                                                struct notifier_block *nb)
1812 {
1813         int err;
1814
1815         err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1816         if (err)
1817                 return err;
1818
1819         call_netdevice_unregister_net_notifiers(nb, net);
1820         return 0;
1821 }
1822
1823 /**
1824  * register_netdevice_notifier_net - register a per-netns network notifier block
1825  * @net: network namespace
1826  * @nb: notifier
1827  *
1828  * Register a notifier to be called when network device events occur.
1829  * The notifier passed is linked into the kernel structures and must
1830  * not be reused until it has been unregistered. A negative errno code
1831  * is returned on a failure.
1832  *
1833  * When registered all registration and up events are replayed
1834  * to the new notifier to allow device to have a race free
1835  * view of the network device list.
1836  */
1837
1838 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1839 {
1840         int err;
1841
1842         rtnl_lock();
1843         err = __register_netdevice_notifier_net(net, nb, false);
1844         rtnl_unlock();
1845         return err;
1846 }
1847 EXPORT_SYMBOL(register_netdevice_notifier_net);
1848
1849 /**
1850  * unregister_netdevice_notifier_net - unregister a per-netns
1851  *                                     network notifier block
1852  * @net: network namespace
1853  * @nb: notifier
1854  *
1855  * Unregister a notifier previously registered by
1856  * register_netdevice_notifier(). The notifier is unlinked into the
1857  * kernel structures and may then be reused. A negative errno code
1858  * is returned on a failure.
1859  *
1860  * After unregistering unregister and down device events are synthesized
1861  * for all devices on the device list to the removed notifier to remove
1862  * the need for special case cleanup code.
1863  */
1864
1865 int unregister_netdevice_notifier_net(struct net *net,
1866                                       struct notifier_block *nb)
1867 {
1868         int err;
1869
1870         rtnl_lock();
1871         err = __unregister_netdevice_notifier_net(net, nb);
1872         rtnl_unlock();
1873         return err;
1874 }
1875 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1876
1877 int register_netdevice_notifier_dev_net(struct net_device *dev,
1878                                         struct notifier_block *nb,
1879                                         struct netdev_net_notifier *nn)
1880 {
1881         int err;
1882
1883         rtnl_lock();
1884         err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1885         if (!err) {
1886                 nn->nb = nb;
1887                 list_add(&nn->list, &dev->net_notifier_list);
1888         }
1889         rtnl_unlock();
1890         return err;
1891 }
1892 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1893
1894 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1895                                           struct notifier_block *nb,
1896                                           struct netdev_net_notifier *nn)
1897 {
1898         int err;
1899
1900         rtnl_lock();
1901         list_del(&nn->list);
1902         err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1903         rtnl_unlock();
1904         return err;
1905 }
1906 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1907
1908 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1909                                              struct net *net)
1910 {
1911         struct netdev_net_notifier *nn;
1912
1913         list_for_each_entry(nn, &dev->net_notifier_list, list) {
1914                 __unregister_netdevice_notifier_net(dev_net(dev), nn->nb);
1915                 __register_netdevice_notifier_net(net, nn->nb, true);
1916         }
1917 }
1918
1919 /**
1920  *      call_netdevice_notifiers_info - call all network notifier blocks
1921  *      @val: value passed unmodified to notifier function
1922  *      @info: notifier information data
1923  *
1924  *      Call all network notifier blocks.  Parameters and return value
1925  *      are as for raw_notifier_call_chain().
1926  */
1927
1928 static int call_netdevice_notifiers_info(unsigned long val,
1929                                          struct netdev_notifier_info *info)
1930 {
1931         struct net *net = dev_net(info->dev);
1932         int ret;
1933
1934         ASSERT_RTNL();
1935
1936         /* Run per-netns notifier block chain first, then run the global one.
1937          * Hopefully, one day, the global one is going to be removed after
1938          * all notifier block registrators get converted to be per-netns.
1939          */
1940         ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1941         if (ret & NOTIFY_STOP_MASK)
1942                 return ret;
1943         return raw_notifier_call_chain(&netdev_chain, val, info);
1944 }
1945
1946 /**
1947  *      call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1948  *                                             for and rollback on error
1949  *      @val_up: value passed unmodified to notifier function
1950  *      @val_down: value passed unmodified to the notifier function when
1951  *                 recovering from an error on @val_up
1952  *      @info: notifier information data
1953  *
1954  *      Call all per-netns network notifier blocks, but not notifier blocks on
1955  *      the global notifier chain. Parameters and return value are as for
1956  *      raw_notifier_call_chain_robust().
1957  */
1958
1959 static int
1960 call_netdevice_notifiers_info_robust(unsigned long val_up,
1961                                      unsigned long val_down,
1962                                      struct netdev_notifier_info *info)
1963 {
1964         struct net *net = dev_net(info->dev);
1965
1966         ASSERT_RTNL();
1967
1968         return raw_notifier_call_chain_robust(&net->netdev_chain,
1969                                               val_up, val_down, info);
1970 }
1971
1972 static int call_netdevice_notifiers_extack(unsigned long val,
1973                                            struct net_device *dev,
1974                                            struct netlink_ext_ack *extack)
1975 {
1976         struct netdev_notifier_info info = {
1977                 .dev = dev,
1978                 .extack = extack,
1979         };
1980
1981         return call_netdevice_notifiers_info(val, &info);
1982 }
1983
1984 /**
1985  *      call_netdevice_notifiers - call all network notifier blocks
1986  *      @val: value passed unmodified to notifier function
1987  *      @dev: net_device pointer passed unmodified to notifier function
1988  *
1989  *      Call all network notifier blocks.  Parameters and return value
1990  *      are as for raw_notifier_call_chain().
1991  */
1992
1993 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1994 {
1995         return call_netdevice_notifiers_extack(val, dev, NULL);
1996 }
1997 EXPORT_SYMBOL(call_netdevice_notifiers);
1998
1999 /**
2000  *      call_netdevice_notifiers_mtu - call all network notifier blocks
2001  *      @val: value passed unmodified to notifier function
2002  *      @dev: net_device pointer passed unmodified to notifier function
2003  *      @arg: additional u32 argument passed to the notifier function
2004  *
2005  *      Call all network notifier blocks.  Parameters and return value
2006  *      are as for raw_notifier_call_chain().
2007  */
2008 static int call_netdevice_notifiers_mtu(unsigned long val,
2009                                         struct net_device *dev, u32 arg)
2010 {
2011         struct netdev_notifier_info_ext info = {
2012                 .info.dev = dev,
2013                 .ext.mtu = arg,
2014         };
2015
2016         BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2017
2018         return call_netdevice_notifiers_info(val, &info.info);
2019 }
2020
2021 #ifdef CONFIG_NET_INGRESS
2022 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2023
2024 void net_inc_ingress_queue(void)
2025 {
2026         static_branch_inc(&ingress_needed_key);
2027 }
2028 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2029
2030 void net_dec_ingress_queue(void)
2031 {
2032         static_branch_dec(&ingress_needed_key);
2033 }
2034 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2035 #endif
2036
2037 #ifdef CONFIG_NET_EGRESS
2038 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2039
2040 void net_inc_egress_queue(void)
2041 {
2042         static_branch_inc(&egress_needed_key);
2043 }
2044 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2045
2046 void net_dec_egress_queue(void)
2047 {
2048         static_branch_dec(&egress_needed_key);
2049 }
2050 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2051 #endif
2052
2053 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2054 EXPORT_SYMBOL(netstamp_needed_key);
2055 #ifdef CONFIG_JUMP_LABEL
2056 static atomic_t netstamp_needed_deferred;
2057 static atomic_t netstamp_wanted;
2058 static void netstamp_clear(struct work_struct *work)
2059 {
2060         int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2061         int wanted;
2062
2063         wanted = atomic_add_return(deferred, &netstamp_wanted);
2064         if (wanted > 0)
2065                 static_branch_enable(&netstamp_needed_key);
2066         else
2067                 static_branch_disable(&netstamp_needed_key);
2068 }
2069 static DECLARE_WORK(netstamp_work, netstamp_clear);
2070 #endif
2071
2072 void net_enable_timestamp(void)
2073 {
2074 #ifdef CONFIG_JUMP_LABEL
2075         int wanted;
2076
2077         while (1) {
2078                 wanted = atomic_read(&netstamp_wanted);
2079                 if (wanted <= 0)
2080                         break;
2081                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
2082                         return;
2083         }
2084         atomic_inc(&netstamp_needed_deferred);
2085         schedule_work(&netstamp_work);
2086 #else
2087         static_branch_inc(&netstamp_needed_key);
2088 #endif
2089 }
2090 EXPORT_SYMBOL(net_enable_timestamp);
2091
2092 void net_disable_timestamp(void)
2093 {
2094 #ifdef CONFIG_JUMP_LABEL
2095         int wanted;
2096
2097         while (1) {
2098                 wanted = atomic_read(&netstamp_wanted);
2099                 if (wanted <= 1)
2100                         break;
2101                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
2102                         return;
2103         }
2104         atomic_dec(&netstamp_needed_deferred);
2105         schedule_work(&netstamp_work);
2106 #else
2107         static_branch_dec(&netstamp_needed_key);
2108 #endif
2109 }
2110 EXPORT_SYMBOL(net_disable_timestamp);
2111
2112 static inline void net_timestamp_set(struct sk_buff *skb)
2113 {
2114         skb->tstamp = 0;
2115         skb->mono_delivery_time = 0;
2116         if (static_branch_unlikely(&netstamp_needed_key))
2117                 skb->tstamp = ktime_get_real();
2118 }
2119
2120 #define net_timestamp_check(COND, SKB)                          \
2121         if (static_branch_unlikely(&netstamp_needed_key)) {     \
2122                 if ((COND) && !(SKB)->tstamp)                   \
2123                         (SKB)->tstamp = ktime_get_real();       \
2124         }                                                       \
2125
2126 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2127 {
2128         return __is_skb_forwardable(dev, skb, true);
2129 }
2130 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2131
2132 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2133                               bool check_mtu)
2134 {
2135         int ret = ____dev_forward_skb(dev, skb, check_mtu);
2136
2137         if (likely(!ret)) {
2138                 skb->protocol = eth_type_trans(skb, dev);
2139                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2140         }
2141
2142         return ret;
2143 }
2144
2145 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2146 {
2147         return __dev_forward_skb2(dev, skb, true);
2148 }
2149 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2150
2151 /**
2152  * dev_forward_skb - loopback an skb to another netif
2153  *
2154  * @dev: destination network device
2155  * @skb: buffer to forward
2156  *
2157  * return values:
2158  *      NET_RX_SUCCESS  (no congestion)
2159  *      NET_RX_DROP     (packet was dropped, but freed)
2160  *
2161  * dev_forward_skb can be used for injecting an skb from the
2162  * start_xmit function of one device into the receive queue
2163  * of another device.
2164  *
2165  * The receiving device may be in another namespace, so
2166  * we have to clear all information in the skb that could
2167  * impact namespace isolation.
2168  */
2169 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2170 {
2171         return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2172 }
2173 EXPORT_SYMBOL_GPL(dev_forward_skb);
2174
2175 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2176 {
2177         return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2178 }
2179
2180 static inline int deliver_skb(struct sk_buff *skb,
2181                               struct packet_type *pt_prev,
2182                               struct net_device *orig_dev)
2183 {
2184         if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2185                 return -ENOMEM;
2186         refcount_inc(&skb->users);
2187         return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2188 }
2189
2190 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2191                                           struct packet_type **pt,
2192                                           struct net_device *orig_dev,
2193                                           __be16 type,
2194                                           struct list_head *ptype_list)
2195 {
2196         struct packet_type *ptype, *pt_prev = *pt;
2197
2198         list_for_each_entry_rcu(ptype, ptype_list, list) {
2199                 if (ptype->type != type)
2200                         continue;
2201                 if (pt_prev)
2202                         deliver_skb(skb, pt_prev, orig_dev);
2203                 pt_prev = ptype;
2204         }
2205         *pt = pt_prev;
2206 }
2207
2208 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2209 {
2210         if (!ptype->af_packet_priv || !skb->sk)
2211                 return false;
2212
2213         if (ptype->id_match)
2214                 return ptype->id_match(ptype, skb->sk);
2215         else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2216                 return true;
2217
2218         return false;
2219 }
2220
2221 /**
2222  * dev_nit_active - return true if any network interface taps are in use
2223  *
2224  * @dev: network device to check for the presence of taps
2225  */
2226 bool dev_nit_active(struct net_device *dev)
2227 {
2228         return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2229 }
2230 EXPORT_SYMBOL_GPL(dev_nit_active);
2231
2232 /*
2233  *      Support routine. Sends outgoing frames to any network
2234  *      taps currently in use.
2235  */
2236
2237 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2238 {
2239         struct packet_type *ptype;
2240         struct sk_buff *skb2 = NULL;
2241         struct packet_type *pt_prev = NULL;
2242         struct list_head *ptype_list = &ptype_all;
2243
2244         rcu_read_lock();
2245 again:
2246         list_for_each_entry_rcu(ptype, ptype_list, list) {
2247                 if (ptype->ignore_outgoing)
2248                         continue;
2249
2250                 /* Never send packets back to the socket
2251                  * they originated from - MvS ([email protected])
2252                  */
2253                 if (skb_loop_sk(ptype, skb))
2254                         continue;
2255
2256                 if (pt_prev) {
2257                         deliver_skb(skb2, pt_prev, skb->dev);
2258                         pt_prev = ptype;
2259                         continue;
2260                 }
2261
2262                 /* need to clone skb, done only once */
2263                 skb2 = skb_clone(skb, GFP_ATOMIC);
2264                 if (!skb2)
2265                         goto out_unlock;
2266
2267                 net_timestamp_set(skb2);
2268
2269                 /* skb->nh should be correctly
2270                  * set by sender, so that the second statement is
2271                  * just protection against buggy protocols.
2272                  */
2273                 skb_reset_mac_header(skb2);
2274
2275                 if (skb_network_header(skb2) < skb2->data ||
2276                     skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2277                         net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2278                                              ntohs(skb2->protocol),
2279                                              dev->name);
2280                         skb_reset_network_header(skb2);
2281                 }
2282
2283                 skb2->transport_header = skb2->network_header;
2284                 skb2->pkt_type = PACKET_OUTGOING;
2285                 pt_prev = ptype;
2286         }
2287
2288         if (ptype_list == &ptype_all) {
2289                 ptype_list = &dev->ptype_all;
2290                 goto again;
2291         }
2292 out_unlock:
2293         if (pt_prev) {
2294                 if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2295                         pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2296                 else
2297                         kfree_skb(skb2);
2298         }
2299         rcu_read_unlock();
2300 }
2301 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2302
2303 /**
2304  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2305  * @dev: Network device
2306  * @txq: number of queues available
2307  *
2308  * If real_num_tx_queues is changed the tc mappings may no longer be
2309  * valid. To resolve this verify the tc mapping remains valid and if
2310  * not NULL the mapping. With no priorities mapping to this
2311  * offset/count pair it will no longer be used. In the worst case TC0
2312  * is invalid nothing can be done so disable priority mappings. If is
2313  * expected that drivers will fix this mapping if they can before
2314  * calling netif_set_real_num_tx_queues.
2315  */
2316 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2317 {
2318         int i;
2319         struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2320
2321         /* If TC0 is invalidated disable TC mapping */
2322         if (tc->offset + tc->count > txq) {
2323                 netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2324                 dev->num_tc = 0;
2325                 return;
2326         }
2327
2328         /* Invalidated prio to tc mappings set to TC0 */
2329         for (i = 1; i < TC_BITMASK + 1; i++) {
2330                 int q = netdev_get_prio_tc_map(dev, i);
2331
2332                 tc = &dev->tc_to_txq[q];
2333                 if (tc->offset + tc->count > txq) {
2334                         netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2335                                     i, q);
2336                         netdev_set_prio_tc_map(dev, i, 0);
2337                 }
2338         }
2339 }
2340
2341 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2342 {
2343         if (dev->num_tc) {
2344                 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2345                 int i;
2346
2347                 /* walk through the TCs and see if it falls into any of them */
2348                 for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2349                         if ((txq - tc->offset) < tc->count)
2350                                 return i;
2351                 }
2352
2353                 /* didn't find it, just return -1 to indicate no match */
2354                 return -1;
2355         }
2356
2357         return 0;
2358 }
2359 EXPORT_SYMBOL(netdev_txq_to_tc);
2360
2361 #ifdef CONFIG_XPS
2362 static struct static_key xps_needed __read_mostly;
2363 static struct static_key xps_rxqs_needed __read_mostly;
2364 static DEFINE_MUTEX(xps_map_mutex);
2365 #define xmap_dereference(P)             \
2366         rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2367
2368 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2369                              struct xps_dev_maps *old_maps, int tci, u16 index)
2370 {
2371         struct xps_map *map = NULL;
2372         int pos;
2373
2374         if (dev_maps)
2375                 map = xmap_dereference(dev_maps->attr_map[tci]);
2376         if (!map)
2377                 return false;
2378
2379         for (pos = map->len; pos--;) {
2380                 if (map->queues[pos] != index)
2381                         continue;
2382
2383                 if (map->len > 1) {
2384                         map->queues[pos] = map->queues[--map->len];
2385                         break;
2386                 }
2387
2388                 if (old_maps)
2389                         RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2390                 RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2391                 kfree_rcu(map, rcu);
2392                 return false;
2393         }
2394
2395         return true;
2396 }
2397
2398 static bool remove_xps_queue_cpu(struct net_device *dev,
2399                                  struct xps_dev_maps *dev_maps,
2400                                  int cpu, u16 offset, u16 count)
2401 {
2402         int num_tc = dev_maps->num_tc;
2403         bool active = false;
2404         int tci;
2405
2406         for (tci = cpu * num_tc; num_tc--; tci++) {
2407                 int i, j;
2408
2409                 for (i = count, j = offset; i--; j++) {
2410                         if (!remove_xps_queue(dev_maps, NULL, tci, j))
2411                                 break;
2412                 }
2413
2414                 active |= i < 0;
2415         }
2416
2417         return active;
2418 }
2419
2420 static void reset_xps_maps(struct net_device *dev,
2421                            struct xps_dev_maps *dev_maps,
2422                            enum xps_map_type type)
2423 {
2424         static_key_slow_dec_cpuslocked(&xps_needed);
2425         if (type == XPS_RXQS)
2426                 static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2427
2428         RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2429
2430         kfree_rcu(dev_maps, rcu);
2431 }
2432
2433 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2434                            u16 offset, u16 count)
2435 {
2436         struct xps_dev_maps *dev_maps;
2437         bool active = false;
2438         int i, j;
2439
2440         dev_maps = xmap_dereference(dev->xps_maps[type]);
2441         if (!dev_maps)
2442                 return;
2443
2444         for (j = 0; j < dev_maps->nr_ids; j++)
2445                 active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2446         if (!active)
2447                 reset_xps_maps(dev, dev_maps, type);
2448
2449         if (type == XPS_CPUS) {
2450                 for (i = offset + (count - 1); count--; i--)
2451                         netdev_queue_numa_node_write(
2452                                 netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2453         }
2454 }
2455
2456 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2457                                    u16 count)
2458 {
2459         if (!static_key_false(&xps_needed))
2460                 return;
2461
2462         cpus_read_lock();
2463         mutex_lock(&xps_map_mutex);
2464
2465         if (static_key_false(&xps_rxqs_needed))
2466                 clean_xps_maps(dev, XPS_RXQS, offset, count);
2467
2468         clean_xps_maps(dev, XPS_CPUS, offset, count);
2469
2470         mutex_unlock(&xps_map_mutex);
2471         cpus_read_unlock();
2472 }
2473
2474 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2475 {
2476         netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2477 }
2478
2479 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2480                                       u16 index, bool is_rxqs_map)
2481 {
2482         struct xps_map *new_map;
2483         int alloc_len = XPS_MIN_MAP_ALLOC;
2484         int i, pos;
2485
2486         for (pos = 0; map && pos < map->len; pos++) {
2487                 if (map->queues[pos] != index)
2488                         continue;
2489                 return map;
2490         }
2491
2492         /* Need to add tx-queue to this CPU's/rx-queue's existing map */
2493         if (map) {
2494                 if (pos < map->alloc_len)
2495                         return map;
2496
2497                 alloc_len = map->alloc_len * 2;
2498         }
2499
2500         /* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2501          *  map
2502          */
2503         if (is_rxqs_map)
2504                 new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2505         else
2506                 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2507                                        cpu_to_node(attr_index));
2508         if (!new_map)
2509                 return NULL;
2510
2511         for (i = 0; i < pos; i++)
2512                 new_map->queues[i] = map->queues[i];
2513         new_map->alloc_len = alloc_len;
2514         new_map->len = pos;
2515
2516         return new_map;
2517 }
2518
2519 /* Copy xps maps at a given index */
2520 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2521                               struct xps_dev_maps *new_dev_maps, int index,
2522                               int tc, bool skip_tc)
2523 {
2524         int i, tci = index * dev_maps->num_tc;
2525         struct xps_map *map;
2526
2527         /* copy maps belonging to foreign traffic classes */
2528         for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2529                 if (i == tc && skip_tc)
2530                         continue;
2531
2532                 /* fill in the new device map from the old device map */
2533                 map = xmap_dereference(dev_maps->attr_map[tci]);
2534                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2535         }
2536 }
2537
2538 /* Must be called under cpus_read_lock */
2539 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2540                           u16 index, enum xps_map_type type)
2541 {
2542         struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2543         const unsigned long *online_mask = NULL;
2544         bool active = false, copy = false;
2545         int i, j, tci, numa_node_id = -2;
2546         int maps_sz, num_tc = 1, tc = 0;
2547         struct xps_map *map, *new_map;
2548         unsigned int nr_ids;
2549
2550         if (dev->num_tc) {
2551                 /* Do not allow XPS on subordinate device directly */
2552                 num_tc = dev->num_tc;
2553                 if (num_tc < 0)
2554                         return -EINVAL;
2555
2556                 /* If queue belongs to subordinate dev use its map */
2557                 dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2558
2559                 tc = netdev_txq_to_tc(dev, index);
2560                 if (tc < 0)
2561                         return -EINVAL;
2562         }
2563
2564         mutex_lock(&xps_map_mutex);
2565
2566         dev_maps = xmap_dereference(dev->xps_maps[type]);
2567         if (type == XPS_RXQS) {
2568                 maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2569                 nr_ids = dev->num_rx_queues;
2570         } else {
2571                 maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2572                 if (num_possible_cpus() > 1)
2573                         online_mask = cpumask_bits(cpu_online_mask);
2574                 nr_ids = nr_cpu_ids;
2575         }
2576
2577         if (maps_sz < L1_CACHE_BYTES)
2578                 maps_sz = L1_CACHE_BYTES;
2579
2580         /* The old dev_maps could be larger or smaller than the one we're
2581          * setting up now, as dev->num_tc or nr_ids could have been updated in
2582          * between. We could try to be smart, but let's be safe instead and only
2583          * copy foreign traffic classes if the two map sizes match.
2584          */
2585         if (dev_maps &&
2586             dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2587                 copy = true;
2588
2589         /* allocate memory for queue storage */
2590         for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2591              j < nr_ids;) {
2592                 if (!new_dev_maps) {
2593                         new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2594                         if (!new_dev_maps) {
2595                                 mutex_unlock(&xps_map_mutex);
2596                                 return -ENOMEM;
2597                         }
2598
2599                         new_dev_maps->nr_ids = nr_ids;
2600                         new_dev_maps->num_tc = num_tc;
2601                 }
2602
2603                 tci = j * num_tc + tc;
2604                 map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2605
2606                 map = expand_xps_map(map, j, index, type == XPS_RXQS);
2607                 if (!map)
2608                         goto error;
2609
2610                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2611         }
2612
2613         if (!new_dev_maps)
2614                 goto out_no_new_maps;
2615
2616         if (!dev_maps) {
2617                 /* Increment static keys at most once per type */
2618                 static_key_slow_inc_cpuslocked(&xps_needed);
2619                 if (type == XPS_RXQS)
2620                         static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2621         }
2622
2623         for (j = 0; j < nr_ids; j++) {
2624                 bool skip_tc = false;
2625
2626                 tci = j * num_tc + tc;
2627                 if (netif_attr_test_mask(j, mask, nr_ids) &&
2628                     netif_attr_test_online(j, online_mask, nr_ids)) {
2629                         /* add tx-queue to CPU/rx-queue maps */
2630                         int pos = 0;
2631
2632                         skip_tc = true;
2633
2634                         map = xmap_dereference(new_dev_maps->attr_map[tci]);
2635                         while ((pos < map->len) && (map->queues[pos] != index))
2636                                 pos++;
2637
2638                         if (pos == map->len)
2639                                 map->queues[map->len++] = index;
2640 #ifdef CONFIG_NUMA
2641                         if (type == XPS_CPUS) {
2642                                 if (numa_node_id == -2)
2643                                         numa_node_id = cpu_to_node(j);
2644                                 else if (numa_node_id != cpu_to_node(j))
2645                                         numa_node_id = -1;
2646                         }
2647 #endif
2648                 }
2649
2650                 if (copy)
2651                         xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2652                                           skip_tc);
2653         }
2654
2655         rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2656
2657         /* Cleanup old maps */
2658         if (!dev_maps)
2659                 goto out_no_old_maps;
2660
2661         for (j = 0; j < dev_maps->nr_ids; j++) {
2662                 for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2663                         map = xmap_dereference(dev_maps->attr_map[tci]);
2664                         if (!map)
2665                                 continue;
2666
2667                         if (copy) {
2668                                 new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2669                                 if (map == new_map)
2670                                         continue;
2671                         }
2672
2673                         RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2674                         kfree_rcu(map, rcu);
2675                 }
2676         }
2677
2678         old_dev_maps = dev_maps;
2679
2680 out_no_old_maps:
2681         dev_maps = new_dev_maps;
2682         active = true;
2683
2684 out_no_new_maps:
2685         if (type == XPS_CPUS)
2686                 /* update Tx queue numa node */
2687                 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2688                                              (numa_node_id >= 0) ?
2689                                              numa_node_id : NUMA_NO_NODE);
2690
2691         if (!dev_maps)
2692                 goto out_no_maps;
2693
2694         /* removes tx-queue from unused CPUs/rx-queues */
2695         for (j = 0; j < dev_maps->nr_ids; j++) {
2696                 tci = j * dev_maps->num_tc;
2697
2698                 for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2699                         if (i == tc &&
2700                             netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2701                             netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2702                                 continue;
2703
2704                         active |= remove_xps_queue(dev_maps,
2705                                                    copy ? old_dev_maps : NULL,
2706                                                    tci, index);
2707                 }
2708         }
2709
2710         if (old_dev_maps)
2711                 kfree_rcu(old_dev_maps, rcu);
2712
2713         /* free map if not active */
2714         if (!active)
2715                 reset_xps_maps(dev, dev_maps, type);
2716
2717 out_no_maps:
2718         mutex_unlock(&xps_map_mutex);
2719
2720         return 0;
2721 error:
2722         /* remove any maps that we added */
2723         for (j = 0; j < nr_ids; j++) {
2724                 for (i = num_tc, tci = j * num_tc; i--; tci++) {
2725                         new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2726                         map = copy ?
2727                               xmap_dereference(dev_maps->attr_map[tci]) :
2728                               NULL;
2729                         if (new_map && new_map != map)
2730                                 kfree(new_map);
2731                 }
2732         }
2733
2734         mutex_unlock(&xps_map_mutex);
2735
2736         kfree(new_dev_maps);
2737         return -ENOMEM;
2738 }
2739 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2740
2741 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2742                         u16 index)
2743 {
2744         int ret;
2745
2746         cpus_read_lock();
2747         ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2748         cpus_read_unlock();
2749
2750         return ret;
2751 }
2752 EXPORT_SYMBOL(netif_set_xps_queue);
2753
2754 #endif
2755 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2756 {
2757         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2758
2759         /* Unbind any subordinate channels */
2760         while (txq-- != &dev->_tx[0]) {
2761                 if (txq->sb_dev)
2762                         netdev_unbind_sb_channel(dev, txq->sb_dev);
2763         }
2764 }
2765
2766 void netdev_reset_tc(struct net_device *dev)
2767 {
2768 #ifdef CONFIG_XPS
2769         netif_reset_xps_queues_gt(dev, 0);
2770 #endif
2771         netdev_unbind_all_sb_channels(dev);
2772
2773         /* Reset TC configuration of device */
2774         dev->num_tc = 0;
2775         memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2776         memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2777 }
2778 EXPORT_SYMBOL(netdev_reset_tc);
2779
2780 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2781 {
2782         if (tc >= dev->num_tc)
2783                 return -EINVAL;
2784
2785 #ifdef CONFIG_XPS
2786         netif_reset_xps_queues(dev, offset, count);
2787 #endif
2788         dev->tc_to_txq[tc].count = count;
2789         dev->tc_to_txq[tc].offset = offset;
2790         return 0;
2791 }
2792 EXPORT_SYMBOL(netdev_set_tc_queue);
2793
2794 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2795 {
2796         if (num_tc > TC_MAX_QUEUE)
2797                 return -EINVAL;
2798
2799 #ifdef CONFIG_XPS
2800         netif_reset_xps_queues_gt(dev, 0);
2801 #endif
2802         netdev_unbind_all_sb_channels(dev);
2803
2804         dev->num_tc = num_tc;
2805         return 0;
2806 }
2807 EXPORT_SYMBOL(netdev_set_num_tc);
2808
2809 void netdev_unbind_sb_channel(struct net_device *dev,
2810                               struct net_device *sb_dev)
2811 {
2812         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2813
2814 #ifdef CONFIG_XPS
2815         netif_reset_xps_queues_gt(sb_dev, 0);
2816 #endif
2817         memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2818         memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2819
2820         while (txq-- != &dev->_tx[0]) {
2821                 if (txq->sb_dev == sb_dev)
2822                         txq->sb_dev = NULL;
2823         }
2824 }
2825 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2826
2827 int netdev_bind_sb_channel_queue(struct net_device *dev,
2828                                  struct net_device *sb_dev,
2829                                  u8 tc, u16 count, u16 offset)
2830 {
2831         /* Make certain the sb_dev and dev are already configured */
2832         if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2833                 return -EINVAL;
2834
2835         /* We cannot hand out queues we don't have */
2836         if ((offset + count) > dev->real_num_tx_queues)
2837                 return -EINVAL;
2838
2839         /* Record the mapping */
2840         sb_dev->tc_to_txq[tc].count = count;
2841         sb_dev->tc_to_txq[tc].offset = offset;
2842
2843         /* Provide a way for Tx queue to find the tc_to_txq map or
2844          * XPS map for itself.
2845          */
2846         while (count--)
2847                 netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2848
2849         return 0;
2850 }
2851 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2852
2853 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2854 {
2855         /* Do not use a multiqueue device to represent a subordinate channel */
2856         if (netif_is_multiqueue(dev))
2857                 return -ENODEV;
2858
2859         /* We allow channels 1 - 32767 to be used for subordinate channels.
2860          * Channel 0 is meant to be "native" mode and used only to represent
2861          * the main root device. We allow writing 0 to reset the device back
2862          * to normal mode after being used as a subordinate channel.
2863          */
2864         if (channel > S16_MAX)
2865                 return -EINVAL;
2866
2867         dev->num_tc = -channel;
2868
2869         return 0;
2870 }
2871 EXPORT_SYMBOL(netdev_set_sb_channel);
2872
2873 /*
2874  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2875  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2876  */
2877 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2878 {
2879         bool disabling;
2880         int rc;
2881
2882         disabling = txq < dev->real_num_tx_queues;
2883
2884         if (txq < 1 || txq > dev->num_tx_queues)
2885                 return -EINVAL;
2886
2887         if (dev->reg_state == NETREG_REGISTERED ||
2888             dev->reg_state == NETREG_UNREGISTERING) {
2889                 ASSERT_RTNL();
2890
2891                 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2892                                                   txq);
2893                 if (rc)
2894                         return rc;
2895
2896                 if (dev->num_tc)
2897                         netif_setup_tc(dev, txq);
2898
2899                 dev_qdisc_change_real_num_tx(dev, txq);
2900
2901                 dev->real_num_tx_queues = txq;
2902
2903                 if (disabling) {
2904                         synchronize_net();
2905                         qdisc_reset_all_tx_gt(dev, txq);
2906 #ifdef CONFIG_XPS
2907                         netif_reset_xps_queues_gt(dev, txq);
2908 #endif
2909                 }
2910         } else {
2911                 dev->real_num_tx_queues = txq;
2912         }
2913
2914         return 0;
2915 }
2916 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2917
2918 #ifdef CONFIG_SYSFS
2919 /**
2920  *      netif_set_real_num_rx_queues - set actual number of RX queues used
2921  *      @dev: Network device
2922  *      @rxq: Actual number of RX queues
2923  *
2924  *      This must be called either with the rtnl_lock held or before
2925  *      registration of the net device.  Returns 0 on success, or a
2926  *      negative error code.  If called before registration, it always
2927  *      succeeds.
2928  */
2929 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2930 {
2931         int rc;
2932
2933         if (rxq < 1 || rxq > dev->num_rx_queues)
2934                 return -EINVAL;
2935
2936         if (dev->reg_state == NETREG_REGISTERED) {
2937                 ASSERT_RTNL();
2938
2939                 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2940                                                   rxq);
2941                 if (rc)
2942                         return rc;
2943         }
2944
2945         dev->real_num_rx_queues = rxq;
2946         return 0;
2947 }
2948 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2949 #endif
2950
2951 /**
2952  *      netif_set_real_num_queues - set actual number of RX and TX queues used
2953  *      @dev: Network device
2954  *      @txq: Actual number of TX queues
2955  *      @rxq: Actual number of RX queues
2956  *
2957  *      Set the real number of both TX and RX queues.
2958  *      Does nothing if the number of queues is already correct.
2959  */
2960 int netif_set_real_num_queues(struct net_device *dev,
2961                               unsigned int txq, unsigned int rxq)
2962 {
2963         unsigned int old_rxq = dev->real_num_rx_queues;
2964         int err;
2965
2966         if (txq < 1 || txq > dev->num_tx_queues ||
2967             rxq < 1 || rxq > dev->num_rx_queues)
2968                 return -EINVAL;
2969
2970         /* Start from increases, so the error path only does decreases -
2971          * decreases can't fail.
2972          */
2973         if (rxq > dev->real_num_rx_queues) {
2974                 err = netif_set_real_num_rx_queues(dev, rxq);
2975                 if (err)
2976                         return err;
2977         }
2978         if (txq > dev->real_num_tx_queues) {
2979                 err = netif_set_real_num_tx_queues(dev, txq);
2980                 if (err)
2981                         goto undo_rx;
2982         }
2983         if (rxq < dev->real_num_rx_queues)
2984                 WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
2985         if (txq < dev->real_num_tx_queues)
2986                 WARN_ON(netif_set_real_num_tx_queues(dev, txq));
2987
2988         return 0;
2989 undo_rx:
2990         WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
2991         return err;
2992 }
2993 EXPORT_SYMBOL(netif_set_real_num_queues);
2994
2995 /**
2996  * netif_set_tso_max_size() - set the max size of TSO frames supported
2997  * @dev:        netdev to update
2998  * @size:       max skb->len of a TSO frame
2999  *
3000  * Set the limit on the size of TSO super-frames the device can handle.
3001  * Unless explicitly set the stack will assume the value of
3002  * %GSO_LEGACY_MAX_SIZE.
3003  */
3004 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
3005 {
3006         dev->tso_max_size = min(GSO_MAX_SIZE, size);
3007         if (size < READ_ONCE(dev->gso_max_size))
3008                 netif_set_gso_max_size(dev, size);
3009 }
3010 EXPORT_SYMBOL(netif_set_tso_max_size);
3011
3012 /**
3013  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3014  * @dev:        netdev to update
3015  * @segs:       max number of TCP segments
3016  *
3017  * Set the limit on the number of TCP segments the device can generate from
3018  * a single TSO super-frame.
3019  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3020  */
3021 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3022 {
3023         dev->tso_max_segs = segs;
3024         if (segs < READ_ONCE(dev->gso_max_segs))
3025                 netif_set_gso_max_segs(dev, segs);
3026 }
3027 EXPORT_SYMBOL(netif_set_tso_max_segs);
3028
3029 /**
3030  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3031  * @to:         netdev to update
3032  * @from:       netdev from which to copy the limits
3033  */
3034 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3035 {
3036         netif_set_tso_max_size(to, from->tso_max_size);
3037         netif_set_tso_max_segs(to, from->tso_max_segs);
3038 }
3039 EXPORT_SYMBOL(netif_inherit_tso_max);
3040
3041 /**
3042  * netif_get_num_default_rss_queues - default number of RSS queues
3043  *
3044  * Default value is the number of physical cores if there are only 1 or 2, or
3045  * divided by 2 if there are more.
3046  */
3047 int netif_get_num_default_rss_queues(void)
3048 {
3049         cpumask_var_t cpus;
3050         int cpu, count = 0;
3051
3052         if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3053                 return 1;
3054
3055         cpumask_copy(cpus, cpu_online_mask);
3056         for_each_cpu(cpu, cpus) {
3057                 ++count;
3058                 cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3059         }
3060         free_cpumask_var(cpus);
3061
3062         return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3063 }
3064 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3065
3066 static void __netif_reschedule(struct Qdisc *q)
3067 {
3068         struct softnet_data *sd;
3069         unsigned long flags;
3070
3071         local_irq_save(flags);
3072         sd = this_cpu_ptr(&softnet_data);
3073         q->next_sched = NULL;
3074         *sd->output_queue_tailp = q;
3075         sd->output_queue_tailp = &q->next_sched;
3076         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3077         local_irq_restore(flags);
3078 }
3079
3080 void __netif_schedule(struct Qdisc *q)
3081 {
3082         if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3083                 __netif_reschedule(q);
3084 }
3085 EXPORT_SYMBOL(__netif_schedule);
3086
3087 struct dev_kfree_skb_cb {
3088         enum skb_free_reason reason;
3089 };
3090
3091 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3092 {
3093         return (struct dev_kfree_skb_cb *)skb->cb;
3094 }
3095
3096 void netif_schedule_queue(struct netdev_queue *txq)
3097 {
3098         rcu_read_lock();
3099         if (!netif_xmit_stopped(txq)) {
3100                 struct Qdisc *q = rcu_dereference(txq->qdisc);
3101
3102                 __netif_schedule(q);
3103         }
3104         rcu_read_unlock();
3105 }
3106 EXPORT_SYMBOL(netif_schedule_queue);
3107
3108 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3109 {
3110         if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3111                 struct Qdisc *q;
3112
3113                 rcu_read_lock();
3114                 q = rcu_dereference(dev_queue->qdisc);
3115                 __netif_schedule(q);
3116                 rcu_read_unlock();
3117         }
3118 }
3119 EXPORT_SYMBOL(netif_tx_wake_queue);
3120
3121 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
3122 {
3123         unsigned long flags;
3124
3125         if (unlikely(!skb))
3126                 return;
3127
3128         if (likely(refcount_read(&skb->users) == 1)) {
3129                 smp_rmb();
3130                 refcount_set(&skb->users, 0);
3131         } else if (likely(!refcount_dec_and_test(&skb->users))) {
3132                 return;
3133         }
3134         get_kfree_skb_cb(skb)->reason = reason;
3135         local_irq_save(flags);
3136         skb->next = __this_cpu_read(softnet_data.completion_queue);
3137         __this_cpu_write(softnet_data.completion_queue, skb);
3138         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3139         local_irq_restore(flags);
3140 }
3141 EXPORT_SYMBOL(__dev_kfree_skb_irq);
3142
3143 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
3144 {
3145         if (in_hardirq() || irqs_disabled())
3146                 __dev_kfree_skb_irq(skb, reason);
3147         else
3148                 dev_kfree_skb(skb);
3149 }
3150 EXPORT_SYMBOL(__dev_kfree_skb_any);
3151
3152
3153 /**
3154  * netif_device_detach - mark device as removed
3155  * @dev: network device
3156  *
3157  * Mark device as removed from system and therefore no longer available.
3158  */
3159 void netif_device_detach(struct net_device *dev)
3160 {
3161         if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3162             netif_running(dev)) {
3163                 netif_tx_stop_all_queues(dev);
3164         }
3165 }
3166 EXPORT_SYMBOL(netif_device_detach);
3167
3168 /**
3169  * netif_device_attach - mark device as attached
3170  * @dev: network device
3171  *
3172  * Mark device as attached from system and restart if needed.
3173  */
3174 void netif_device_attach(struct net_device *dev)
3175 {
3176         if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3177             netif_running(dev)) {
3178                 netif_tx_wake_all_queues(dev);
3179                 __netdev_watchdog_up(dev);
3180         }
3181 }
3182 EXPORT_SYMBOL(netif_device_attach);
3183
3184 /*
3185  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3186  * to be used as a distribution range.
3187  */
3188 static u16 skb_tx_hash(const struct net_device *dev,
3189                        const struct net_device *sb_dev,
3190                        struct sk_buff *skb)
3191 {
3192         u32 hash;
3193         u16 qoffset = 0;
3194         u16 qcount = dev->real_num_tx_queues;
3195
3196         if (dev->num_tc) {
3197                 u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3198
3199                 qoffset = sb_dev->tc_to_txq[tc].offset;
3200                 qcount = sb_dev->tc_to_txq[tc].count;
3201                 if (unlikely(!qcount)) {
3202                         net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3203                                              sb_dev->name, qoffset, tc);
3204                         qoffset = 0;
3205                         qcount = dev->real_num_tx_queues;
3206                 }
3207         }
3208
3209         if (skb_rx_queue_recorded(skb)) {
3210                 hash = skb_get_rx_queue(skb);
3211                 if (hash >= qoffset)
3212                         hash -= qoffset;
3213                 while (unlikely(hash >= qcount))
3214                         hash -= qcount;
3215                 return hash + qoffset;
3216         }
3217
3218         return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3219 }
3220
3221 static void skb_warn_bad_offload(const struct sk_buff *skb)
3222 {
3223         static const netdev_features_t null_features;
3224         struct net_device *dev = skb->dev;
3225         const char *name = "";
3226
3227         if (!net_ratelimit())
3228                 return;
3229
3230         if (dev) {
3231                 if (dev->dev.parent)
3232                         name = dev_driver_string(dev->dev.parent);
3233                 else
3234                         name = netdev_name(dev);
3235         }
3236         skb_dump(KERN_WARNING, skb, false);
3237         WARN(1, "%s: caps=(%pNF, %pNF)\n",
3238              name, dev ? &dev->features : &null_features,
3239              skb->sk ? &skb->sk->sk_route_caps : &null_features);
3240 }
3241
3242 /*
3243  * Invalidate hardware checksum when packet is to be mangled, and
3244  * complete checksum manually on outgoing path.
3245  */
3246 int skb_checksum_help(struct sk_buff *skb)
3247 {
3248         __wsum csum;
3249         int ret = 0, offset;
3250
3251         if (skb->ip_summed == CHECKSUM_COMPLETE)
3252                 goto out_set_summed;
3253
3254         if (unlikely(skb_is_gso(skb))) {
3255                 skb_warn_bad_offload(skb);
3256                 return -EINVAL;
3257         }
3258
3259         /* Before computing a checksum, we should make sure no frag could
3260          * be modified by an external entity : checksum could be wrong.
3261          */
3262         if (skb_has_shared_frag(skb)) {
3263                 ret = __skb_linearize(skb);
3264                 if (ret)
3265                         goto out;
3266         }
3267
3268         offset = skb_checksum_start_offset(skb);
3269         ret = -EINVAL;
3270         if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3271                 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3272                 goto out;
3273         }
3274         csum = skb_checksum(skb, offset, skb->len - offset, 0);
3275
3276         offset += skb->csum_offset;
3277         if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
3278                 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3279                 goto out;
3280         }
3281         ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3282         if (ret)
3283                 goto out;
3284
3285         *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3286 out_set_summed:
3287         skb->ip_summed = CHECKSUM_NONE;
3288 out:
3289         return ret;
3290 }
3291 EXPORT_SYMBOL(skb_checksum_help);
3292
3293 int skb_crc32c_csum_help(struct sk_buff *skb)
3294 {
3295         __le32 crc32c_csum;
3296         int ret = 0, offset, start;
3297
3298         if (skb->ip_summed != CHECKSUM_PARTIAL)
3299                 goto out;
3300
3301         if (unlikely(skb_is_gso(skb)))
3302                 goto out;
3303
3304         /* Before computing a checksum, we should make sure no frag could
3305          * be modified by an external entity : checksum could be wrong.
3306          */
3307         if (unlikely(skb_has_shared_frag(skb))) {
3308                 ret = __skb_linearize(skb);
3309                 if (ret)
3310                         goto out;
3311         }
3312         start = skb_checksum_start_offset(skb);
3313         offset = start + offsetof(struct sctphdr, checksum);
3314         if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3315                 ret = -EINVAL;
3316                 goto out;
3317         }
3318
3319         ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3320         if (ret)
3321                 goto out;
3322
3323         crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3324                                                   skb->len - start, ~(__u32)0,
3325                                                   crc32c_csum_stub));
3326         *(__le32 *)(skb->data + offset) = crc32c_csum;
3327         skb->ip_summed = CHECKSUM_NONE;
3328         skb->csum_not_inet = 0;
3329 out:
3330         return ret;
3331 }
3332
3333 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3334 {
3335         __be16 type = skb->protocol;
3336
3337         /* Tunnel gso handlers can set protocol to ethernet. */
3338         if (type == htons(ETH_P_TEB)) {
3339                 struct ethhdr *eth;
3340
3341                 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3342                         return 0;
3343
3344                 eth = (struct ethhdr *)skb->data;
3345                 type = eth->h_proto;
3346         }
3347
3348         return __vlan_get_protocol(skb, type, depth);
3349 }
3350
3351 /* openvswitch calls this on rx path, so we need a different check.
3352  */
3353 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3354 {
3355         if (tx_path)
3356                 return skb->ip_summed != CHECKSUM_PARTIAL &&
3357                        skb->ip_summed != CHECKSUM_UNNECESSARY;
3358
3359         return skb->ip_summed == CHECKSUM_NONE;
3360 }
3361
3362 /**
3363  *      __skb_gso_segment - Perform segmentation on skb.
3364  *      @skb: buffer to segment
3365  *      @features: features for the output path (see dev->features)
3366  *      @tx_path: whether it is called in TX path
3367  *
3368  *      This function segments the given skb and returns a list of segments.
3369  *
3370  *      It may return NULL if the skb requires no segmentation.  This is
3371  *      only possible when GSO is used for verifying header integrity.
3372  *
3373  *      Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3374  */
3375 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3376                                   netdev_features_t features, bool tx_path)
3377 {
3378         struct sk_buff *segs;
3379
3380         if (unlikely(skb_needs_check(skb, tx_path))) {
3381                 int err;
3382
3383                 /* We're going to init ->check field in TCP or UDP header */
3384                 err = skb_cow_head(skb, 0);
3385                 if (err < 0)
3386                         return ERR_PTR(err);
3387         }
3388
3389         /* Only report GSO partial support if it will enable us to
3390          * support segmentation on this frame without needing additional
3391          * work.
3392          */
3393         if (features & NETIF_F_GSO_PARTIAL) {
3394                 netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3395                 struct net_device *dev = skb->dev;
3396
3397                 partial_features |= dev->features & dev->gso_partial_features;
3398                 if (!skb_gso_ok(skb, features | partial_features))
3399                         features &= ~NETIF_F_GSO_PARTIAL;
3400         }
3401
3402         BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3403                      sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3404
3405         SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3406         SKB_GSO_CB(skb)->encap_level = 0;
3407
3408         skb_reset_mac_header(skb);
3409         skb_reset_mac_len(skb);
3410
3411         segs = skb_mac_gso_segment(skb, features);
3412
3413         if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3414                 skb_warn_bad_offload(skb);
3415
3416         return segs;
3417 }
3418 EXPORT_SYMBOL(__skb_gso_segment);
3419
3420 /* Take action when hardware reception checksum errors are detected. */
3421 #ifdef CONFIG_BUG
3422 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3423 {
3424         netdev_err(dev, "hw csum failure\n");
3425         skb_dump(KERN_ERR, skb, true);
3426         dump_stack();
3427 }
3428
3429 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3430 {
3431         DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3432 }
3433 EXPORT_SYMBOL(netdev_rx_csum_fault);
3434 #endif
3435
3436 /* XXX: check that highmem exists at all on the given machine. */
3437 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3438 {
3439 #ifdef CONFIG_HIGHMEM
3440         int i;
3441
3442         if (!(dev->features & NETIF_F_HIGHDMA)) {
3443                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3444                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3445
3446                         if (PageHighMem(skb_frag_page(frag)))
3447                                 return 1;
3448                 }
3449         }
3450 #endif
3451         return 0;
3452 }
3453
3454 /* If MPLS offload request, verify we are testing hardware MPLS features
3455  * instead of standard features for the netdev.
3456  */
3457 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3458 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3459                                            netdev_features_t features,
3460                                            __be16 type)
3461 {
3462         if (eth_p_mpls(type))
3463                 features &= skb->dev->mpls_features;
3464
3465         return features;
3466 }
3467 #else
3468 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3469                                            netdev_features_t features,
3470                                            __be16 type)
3471 {
3472         return features;
3473 }
3474 #endif
3475
3476 static netdev_features_t harmonize_features(struct sk_buff *skb,
3477         netdev_features_t features)
3478 {
3479         __be16 type;
3480
3481         type = skb_network_protocol(skb, NULL);
3482         features = net_mpls_features(skb, features, type);
3483
3484         if (skb->ip_summed != CHECKSUM_NONE &&
3485             !can_checksum_protocol(features, type)) {
3486                 features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3487         }
3488         if (illegal_highdma(skb->dev, skb))
3489                 features &= ~NETIF_F_SG;
3490
3491         return features;
3492 }
3493
3494 netdev_features_t passthru_features_check(struct sk_buff *skb,
3495                                           struct net_device *dev,
3496                                           netdev_features_t features)
3497 {
3498         return features;
3499 }
3500 EXPORT_SYMBOL(passthru_features_check);
3501
3502 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3503                                              struct net_device *dev,
3504                                              netdev_features_t features)
3505 {
3506         return vlan_features_check(skb, features);
3507 }
3508
3509 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3510                                             struct net_device *dev,
3511                                             netdev_features_t features)
3512 {
3513         u16 gso_segs = skb_shinfo(skb)->gso_segs;
3514
3515         if (gso_segs > READ_ONCE(dev->gso_max_segs))
3516                 return features & ~NETIF_F_GSO_MASK;
3517
3518         if (!skb_shinfo(skb)->gso_type) {
3519                 skb_warn_bad_offload(skb);
3520                 return features & ~NETIF_F_GSO_MASK;
3521         }
3522
3523         /* Support for GSO partial features requires software
3524          * intervention before we can actually process the packets
3525          * so we need to strip support for any partial features now
3526          * and we can pull them back in after we have partially
3527          * segmented the frame.
3528          */
3529         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3530                 features &= ~dev->gso_partial_features;
3531
3532         /* Make sure to clear the IPv4 ID mangling feature if the
3533          * IPv4 header has the potential to be fragmented.
3534          */
3535         if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3536                 struct iphdr *iph = skb->encapsulation ?
3537                                     inner_ip_hdr(skb) : ip_hdr(skb);
3538
3539                 if (!(iph->frag_off & htons(IP_DF)))
3540                         features &= ~NETIF_F_TSO_MANGLEID;
3541         }
3542
3543         return features;
3544 }
3545
3546 netdev_features_t netif_skb_features(struct sk_buff *skb)
3547 {
3548         struct net_device *dev = skb->dev;
3549         netdev_features_t features = dev->features;
3550
3551         if (skb_is_gso(skb))
3552                 features = gso_features_check(skb, dev, features);
3553
3554         /* If encapsulation offload request, verify we are testing
3555          * hardware encapsulation features instead of standard
3556          * features for the netdev
3557          */
3558         if (skb->encapsulation)
3559                 features &= dev->hw_enc_features;
3560
3561         if (skb_vlan_tagged(skb))
3562                 features = netdev_intersect_features(features,
3563                                                      dev->vlan_features |
3564                                                      NETIF_F_HW_VLAN_CTAG_TX |
3565                                                      NETIF_F_HW_VLAN_STAG_TX);
3566
3567         if (dev->netdev_ops->ndo_features_check)
3568                 features &= dev->netdev_ops->ndo_features_check(skb, dev,
3569                                                                 features);
3570         else
3571                 features &= dflt_features_check(skb, dev, features);
3572
3573         return harmonize_features(skb, features);
3574 }
3575 EXPORT_SYMBOL(netif_skb_features);
3576
3577 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3578                     struct netdev_queue *txq, bool more)
3579 {
3580         unsigned int len;
3581         int rc;
3582
3583         if (dev_nit_active(dev))
3584                 dev_queue_xmit_nit(skb, dev);
3585
3586         len = skb->len;
3587         trace_net_dev_start_xmit(skb, dev);
3588         rc = netdev_start_xmit(skb, dev, txq, more);
3589         trace_net_dev_xmit(skb, rc, dev, len);
3590
3591         return rc;
3592 }
3593
3594 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3595                                     struct netdev_queue *txq, int *ret)
3596 {
3597         struct sk_buff *skb = first;
3598         int rc = NETDEV_TX_OK;
3599
3600         while (skb) {
3601                 struct sk_buff *next = skb->next;
3602
3603                 skb_mark_not_on_list(skb);
3604                 rc = xmit_one(skb, dev, txq, next != NULL);
3605                 if (unlikely(!dev_xmit_complete(rc))) {
3606                         skb->next = next;
3607                         goto out;
3608                 }
3609
3610                 skb = next;
3611                 if (netif_tx_queue_stopped(txq) && skb) {
3612                         rc = NETDEV_TX_BUSY;
3613                         break;
3614                 }
3615         }
3616
3617 out:
3618         *ret = rc;
3619         return skb;
3620 }
3621
3622 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3623                                           netdev_features_t features)
3624 {
3625         if (skb_vlan_tag_present(skb) &&
3626             !vlan_hw_offload_capable(features, skb->vlan_proto))
3627                 skb = __vlan_hwaccel_push_inside(skb);
3628         return skb;
3629 }
3630
3631 int skb_csum_hwoffload_help(struct sk_buff *skb,
3632                             const netdev_features_t features)
3633 {
3634         if (unlikely(skb_csum_is_sctp(skb)))
3635                 return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3636                         skb_crc32c_csum_help(skb);
3637
3638         if (features & NETIF_F_HW_CSUM)
3639                 return 0;
3640
3641         if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3642                 switch (skb->csum_offset) {
3643                 case offsetof(struct tcphdr, check):
3644                 case offsetof(struct udphdr, check):
3645                         return 0;
3646                 }
3647         }
3648
3649         return skb_checksum_help(skb);
3650 }
3651 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3652
3653 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3654 {
3655         netdev_features_t features;
3656
3657         features = netif_skb_features(skb);
3658         skb = validate_xmit_vlan(skb, features);
3659         if (unlikely(!skb))
3660                 goto out_null;
3661
3662         skb = sk_validate_xmit_skb(skb, dev);
3663         if (unlikely(!skb))
3664                 goto out_null;
3665
3666         if (netif_needs_gso(skb, features)) {
3667                 struct sk_buff *segs;
3668
3669                 segs = skb_gso_segment(skb, features);
3670                 if (IS_ERR(segs)) {
3671                         goto out_kfree_skb;
3672                 } else if (segs) {
3673                         consume_skb(skb);
3674                         skb = segs;
3675                 }
3676         } else {
3677                 if (skb_needs_linearize(skb, features) &&
3678                     __skb_linearize(skb))
3679                         goto out_kfree_skb;
3680
3681                 /* If packet is not checksummed and device does not
3682                  * support checksumming for this protocol, complete
3683                  * checksumming here.
3684                  */
3685                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3686                         if (skb->encapsulation)
3687                                 skb_set_inner_transport_header(skb,
3688                                                                skb_checksum_start_offset(skb));
3689                         else
3690                                 skb_set_transport_header(skb,
3691                                                          skb_checksum_start_offset(skb));
3692                         if (skb_csum_hwoffload_help(skb, features))
3693                                 goto out_kfree_skb;
3694                 }
3695         }
3696
3697         skb = validate_xmit_xfrm(skb, features, again);
3698
3699         return skb;
3700
3701 out_kfree_skb:
3702         kfree_skb(skb);
3703 out_null:
3704         dev_core_stats_tx_dropped_inc(dev);
3705         return NULL;
3706 }
3707
3708 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3709 {
3710         struct sk_buff *next, *head = NULL, *tail;
3711
3712         for (; skb != NULL; skb = next) {
3713                 next = skb->next;
3714                 skb_mark_not_on_list(skb);
3715
3716                 /* in case skb wont be segmented, point to itself */
3717                 skb->prev = skb;
3718
3719                 skb = validate_xmit_skb(skb, dev, again);
3720                 if (!skb)
3721                         continue;
3722
3723                 if (!head)
3724                         head = skb;
3725                 else
3726                         tail->next = skb;
3727                 /* If skb was segmented, skb->prev points to
3728                  * the last segment. If not, it still contains skb.
3729                  */
3730                 tail = skb->prev;
3731         }
3732         return head;
3733 }
3734 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3735
3736 static void qdisc_pkt_len_init(struct sk_buff *skb)
3737 {
3738         const struct skb_shared_info *shinfo = skb_shinfo(skb);
3739
3740         qdisc_skb_cb(skb)->pkt_len = skb->len;
3741
3742         /* To get more precise estimation of bytes sent on wire,
3743          * we add to pkt_len the headers size of all segments
3744          */
3745         if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3746                 unsigned int hdr_len;
3747                 u16 gso_segs = shinfo->gso_segs;
3748
3749                 /* mac layer + network layer */
3750                 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
3751
3752                 /* + transport layer */
3753                 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3754                         const struct tcphdr *th;
3755                         struct tcphdr _tcphdr;
3756
3757                         th = skb_header_pointer(skb, skb_transport_offset(skb),
3758                                                 sizeof(_tcphdr), &_tcphdr);
3759                         if (likely(th))
3760                                 hdr_len += __tcp_hdrlen(th);
3761                 } else {
3762                         struct udphdr _udphdr;
3763
3764                         if (skb_header_pointer(skb, skb_transport_offset(skb),
3765                                                sizeof(_udphdr), &_udphdr))
3766                                 hdr_len += sizeof(struct udphdr);
3767                 }
3768
3769                 if (shinfo->gso_type & SKB_GSO_DODGY)
3770                         gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3771                                                 shinfo->gso_size);
3772
3773                 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3774         }
3775 }
3776
3777 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3778                              struct sk_buff **to_free,
3779                              struct netdev_queue *txq)
3780 {
3781         int rc;
3782
3783         rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3784         if (rc == NET_XMIT_SUCCESS)
3785                 trace_qdisc_enqueue(q, txq, skb);
3786         return rc;
3787 }
3788
3789 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3790                                  struct net_device *dev,
3791                                  struct netdev_queue *txq)
3792 {
3793         spinlock_t *root_lock = qdisc_lock(q);
3794         struct sk_buff *to_free = NULL;
3795         bool contended;
3796         int rc;
3797
3798         qdisc_calculate_pkt_len(skb, q);
3799
3800         if (q->flags & TCQ_F_NOLOCK) {
3801                 if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3802                     qdisc_run_begin(q)) {
3803                         /* Retest nolock_qdisc_is_empty() within the protection
3804                          * of q->seqlock to protect from racing with requeuing.
3805                          */
3806                         if (unlikely(!nolock_qdisc_is_empty(q))) {
3807                                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3808                                 __qdisc_run(q);
3809                                 qdisc_run_end(q);
3810
3811                                 goto no_lock_out;
3812                         }
3813
3814                         qdisc_bstats_cpu_update(q, skb);
3815                         if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3816                             !nolock_qdisc_is_empty(q))
3817                                 __qdisc_run(q);
3818
3819                         qdisc_run_end(q);
3820                         return NET_XMIT_SUCCESS;
3821                 }
3822
3823                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3824                 qdisc_run(q);
3825
3826 no_lock_out:
3827                 if (unlikely(to_free))
3828                         kfree_skb_list_reason(to_free,
3829                                               SKB_DROP_REASON_QDISC_DROP);
3830                 return rc;
3831         }
3832
3833         /*
3834          * Heuristic to force contended enqueues to serialize on a
3835          * separate lock before trying to get qdisc main lock.
3836          * This permits qdisc->running owner to get the lock more
3837          * often and dequeue packets faster.
3838          * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3839          * and then other tasks will only enqueue packets. The packets will be
3840          * sent after the qdisc owner is scheduled again. To prevent this
3841          * scenario the task always serialize on the lock.
3842          */
3843         contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3844         if (unlikely(contended))
3845                 spin_lock(&q->busylock);
3846
3847         spin_lock(root_lock);
3848         if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3849                 __qdisc_drop(skb, &to_free);
3850                 rc = NET_XMIT_DROP;
3851         } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3852                    qdisc_run_begin(q)) {
3853                 /*
3854                  * This is a work-conserving queue; there are no old skbs
3855                  * waiting to be sent out; and the qdisc is not running -
3856                  * xmit the skb directly.
3857                  */
3858
3859                 qdisc_bstats_update(q, skb);
3860
3861                 if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3862                         if (unlikely(contended)) {
3863                                 spin_unlock(&q->busylock);
3864                                 contended = false;
3865                         }
3866                         __qdisc_run(q);
3867                 }
3868
3869                 qdisc_run_end(q);
3870                 rc = NET_XMIT_SUCCESS;
3871         } else {
3872                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3873                 if (qdisc_run_begin(q)) {
3874                         if (unlikely(contended)) {
3875                                 spin_unlock(&q->busylock);
3876                                 contended = false;
3877                         }
3878                         __qdisc_run(q);
3879                         qdisc_run_end(q);
3880                 }
3881         }
3882         spin_unlock(root_lock);
3883         if (unlikely(to_free))
3884                 kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3885         if (unlikely(contended))
3886                 spin_unlock(&q->busylock);
3887         return rc;
3888 }
3889
3890 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3891 static void skb_update_prio(struct sk_buff *skb)
3892 {
3893         const struct netprio_map *map;
3894         const struct sock *sk;
3895         unsigned int prioidx;
3896
3897         if (skb->priority)
3898                 return;
3899         map = rcu_dereference_bh(skb->dev->priomap);
3900         if (!map)
3901                 return;
3902         sk = skb_to_full_sk(skb);
3903         if (!sk)
3904                 return;
3905
3906         prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3907
3908         if (prioidx < map->priomap_len)
3909                 skb->priority = map->priomap[prioidx];
3910 }
3911 #else
3912 #define skb_update_prio(skb)
3913 #endif
3914
3915 /**
3916  *      dev_loopback_xmit - loop back @skb
3917  *      @net: network namespace this loopback is happening in
3918  *      @sk:  sk needed to be a netfilter okfn
3919  *      @skb: buffer to transmit
3920  */
3921 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3922 {
3923         skb_reset_mac_header(skb);
3924         __skb_pull(skb, skb_network_offset(skb));
3925         skb->pkt_type = PACKET_LOOPBACK;
3926         if (skb->ip_summed == CHECKSUM_NONE)
3927                 skb->ip_summed = CHECKSUM_UNNECESSARY;
3928         WARN_ON(!skb_dst(skb));
3929         skb_dst_force(skb);
3930         netif_rx(skb);
3931         return 0;
3932 }
3933 EXPORT_SYMBOL(dev_loopback_xmit);
3934
3935 #ifdef CONFIG_NET_EGRESS
3936 static struct sk_buff *
3937 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3938 {
3939 #ifdef CONFIG_NET_CLS_ACT
3940         struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3941         struct tcf_result cl_res;
3942
3943         if (!miniq)
3944                 return skb;
3945
3946         /* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3947         tc_skb_cb(skb)->mru = 0;
3948         tc_skb_cb(skb)->post_ct = false;
3949         mini_qdisc_bstats_cpu_update(miniq, skb);
3950
3951         switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3952         case TC_ACT_OK:
3953         case TC_ACT_RECLASSIFY:
3954                 skb->tc_index = TC_H_MIN(cl_res.classid);
3955                 break;
3956         case TC_ACT_SHOT:
3957                 mini_qdisc_qstats_cpu_drop(miniq);
3958                 *ret = NET_XMIT_DROP;
3959                 kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
3960                 return NULL;
3961         case TC_ACT_STOLEN:
3962         case TC_ACT_QUEUED:
3963         case TC_ACT_TRAP:
3964                 *ret = NET_XMIT_SUCCESS;
3965                 consume_skb(skb);
3966                 return NULL;
3967         case TC_ACT_REDIRECT:
3968                 /* No need to push/pop skb's mac_header here on egress! */
3969                 skb_do_redirect(skb);
3970                 *ret = NET_XMIT_SUCCESS;
3971                 return NULL;
3972         default:
3973                 break;
3974         }
3975 #endif /* CONFIG_NET_CLS_ACT */
3976
3977         return skb;
3978 }
3979
3980 static struct netdev_queue *
3981 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3982 {
3983         int qm = skb_get_queue_mapping(skb);
3984
3985         return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3986 }
3987
3988 static bool netdev_xmit_txqueue_skipped(void)
3989 {
3990         return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3991 }
3992
3993 void netdev_xmit_skip_txqueue(bool skip)
3994 {
3995         __this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3996 }
3997 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3998 #endif /* CONFIG_NET_EGRESS */
3999
4000 #ifdef CONFIG_XPS
4001 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
4002                                struct xps_dev_maps *dev_maps, unsigned int tci)
4003 {
4004         int tc = netdev_get_prio_tc_map(dev, skb->priority);
4005         struct xps_map *map;
4006         int queue_index = -1;
4007
4008         if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4009                 return queue_index;
4010
4011         tci *= dev_maps->num_tc;
4012         tci += tc;
4013
4014         map = rcu_dereference(dev_maps->attr_map[tci]);
4015         if (map) {
4016                 if (map->len == 1)
4017                         queue_index = map->queues[0];
4018                 else
4019                         queue_index = map->queues[reciprocal_scale(
4020                                                 skb_get_hash(skb), map->len)];
4021                 if (unlikely(queue_index >= dev->real_num_tx_queues))
4022                         queue_index = -1;
4023         }
4024         return queue_index;
4025 }
4026 #endif
4027
4028 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4029                          struct sk_buff *skb)
4030 {
4031 #ifdef CONFIG_XPS
4032         struct xps_dev_maps *dev_maps;
4033         struct sock *sk = skb->sk;
4034         int queue_index = -1;
4035
4036         if (!static_key_false(&xps_needed))
4037                 return -1;
4038
4039         rcu_read_lock();
4040         if (!static_key_false(&xps_rxqs_needed))
4041                 goto get_cpus_map;
4042
4043         dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4044         if (dev_maps) {
4045                 int tci = sk_rx_queue_get(sk);
4046
4047                 if (tci >= 0)
4048                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4049                                                           tci);
4050         }
4051
4052 get_cpus_map:
4053         if (queue_index < 0) {
4054                 dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4055                 if (dev_maps) {
4056                         unsigned int tci = skb->sender_cpu - 1;
4057
4058                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4059                                                           tci);
4060                 }
4061         }
4062         rcu_read_unlock();
4063
4064         return queue_index;
4065 #else
4066         return -1;
4067 #endif
4068 }
4069
4070 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4071                      struct net_device *sb_dev)
4072 {
4073         return 0;
4074 }
4075 EXPORT_SYMBOL(dev_pick_tx_zero);
4076
4077 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4078                        struct net_device *sb_dev)
4079 {
4080         return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4081 }
4082 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4083
4084 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4085                      struct net_device *sb_dev)
4086 {
4087         struct sock *sk = skb->sk;
4088         int queue_index = sk_tx_queue_get(sk);
4089
4090         sb_dev = sb_dev ? : dev;
4091
4092         if (queue_index < 0 || skb->ooo_okay ||
4093             queue_index >= dev->real_num_tx_queues) {
4094                 int new_index = get_xps_queue(dev, sb_dev, skb);
4095
4096                 if (new_index < 0)
4097                         new_index = skb_tx_hash(dev, sb_dev, skb);
4098
4099                 if (queue_index != new_index && sk &&
4100                     sk_fullsock(sk) &&
4101                     rcu_access_pointer(sk->sk_dst_cache))
4102                         sk_tx_queue_set(sk, new_index);
4103
4104                 queue_index = new_index;
4105         }
4106
4107         return queue_index;
4108 }
4109 EXPORT_SYMBOL(netdev_pick_tx);
4110
4111 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4112                                          struct sk_buff *skb,
4113                                          struct net_device *sb_dev)
4114 {
4115         int queue_index = 0;
4116
4117 #ifdef CONFIG_XPS
4118         u32 sender_cpu = skb->sender_cpu - 1;
4119
4120         if (sender_cpu >= (u32)NR_CPUS)
4121                 skb->sender_cpu = raw_smp_processor_id() + 1;
4122 #endif
4123
4124         if (dev->real_num_tx_queues != 1) {
4125                 const struct net_device_ops *ops = dev->netdev_ops;
4126
4127                 if (ops->ndo_select_queue)
4128                         queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4129                 else
4130                         queue_index = netdev_pick_tx(dev, skb, sb_dev);
4131
4132                 queue_index = netdev_cap_txqueue(dev, queue_index);
4133         }
4134
4135         skb_set_queue_mapping(skb, queue_index);
4136         return netdev_get_tx_queue(dev, queue_index);
4137 }
4138
4139 /**
4140  * __dev_queue_xmit() - transmit a buffer
4141  * @skb:        buffer to transmit
4142  * @sb_dev:     suboordinate device used for L2 forwarding offload
4143  *
4144  * Queue a buffer for transmission to a network device. The caller must
4145  * have set the device and priority and built the buffer before calling
4146  * this function. The function can be called from an interrupt.
4147  *
4148  * When calling this method, interrupts MUST be enabled. This is because
4149  * the BH enable code must have IRQs enabled so that it will not deadlock.
4150  *
4151  * Regardless of the return value, the skb is consumed, so it is currently
4152  * difficult to retry a send to this method. (You can bump the ref count
4153  * before sending to hold a reference for retry if you are careful.)
4154  *
4155  * Return:
4156  * * 0                          - buffer successfully transmitted
4157  * * positive qdisc return code - NET_XMIT_DROP etc.
4158  * * negative errno             - other errors
4159  */
4160 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4161 {
4162         struct net_device *dev = skb->dev;
4163         struct netdev_queue *txq = NULL;
4164         struct Qdisc *q;
4165         int rc = -ENOMEM;
4166         bool again = false;
4167
4168         skb_reset_mac_header(skb);
4169
4170         if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4171                 __skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4172
4173         /* Disable soft irqs for various locks below. Also
4174          * stops preemption for RCU.
4175          */
4176         rcu_read_lock_bh();
4177
4178         skb_update_prio(skb);
4179
4180         qdisc_pkt_len_init(skb);
4181 #ifdef CONFIG_NET_CLS_ACT
4182         skb->tc_at_ingress = 0;
4183 #endif
4184 #ifdef CONFIG_NET_EGRESS
4185         if (static_branch_unlikely(&egress_needed_key)) {
4186                 if (nf_hook_egress_active()) {
4187                         skb = nf_hook_egress(skb, &rc, dev);
4188                         if (!skb)
4189                                 goto out;
4190                 }
4191
4192                 netdev_xmit_skip_txqueue(false);
4193
4194                 nf_skip_egress(skb, true);
4195                 skb = sch_handle_egress(skb, &rc, dev);
4196                 if (!skb)
4197                         goto out;
4198                 nf_skip_egress(skb, false);
4199
4200                 if (netdev_xmit_txqueue_skipped())
4201                         txq = netdev_tx_queue_mapping(dev, skb);
4202         }
4203 #endif
4204         /* If device/qdisc don't need skb->dst, release it right now while
4205          * its hot in this cpu cache.
4206          */
4207         if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4208                 skb_dst_drop(skb);
4209         else
4210                 skb_dst_force(skb);
4211
4212         if (!txq)
4213                 txq = netdev_core_pick_tx(dev, skb, sb_dev);
4214
4215         q = rcu_dereference_bh(txq->qdisc);
4216
4217         trace_net_dev_queue(skb);
4218         if (q->enqueue) {
4219                 rc = __dev_xmit_skb(skb, q, dev, txq);
4220                 goto out;
4221         }
4222
4223         /* The device has no queue. Common case for software devices:
4224          * loopback, all the sorts of tunnels...
4225
4226          * Really, it is unlikely that netif_tx_lock protection is necessary
4227          * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4228          * counters.)
4229          * However, it is possible, that they rely on protection
4230          * made by us here.
4231
4232          * Check this and shot the lock. It is not prone from deadlocks.
4233          *Either shot noqueue qdisc, it is even simpler 8)
4234          */
4235         if (dev->flags & IFF_UP) {
4236                 int cpu = smp_processor_id(); /* ok because BHs are off */
4237
4238                 /* Other cpus might concurrently change txq->xmit_lock_owner
4239                  * to -1 or to their cpu id, but not to our id.
4240                  */
4241                 if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4242                         if (dev_xmit_recursion())
4243                                 goto recursion_alert;
4244
4245                         skb = validate_xmit_skb(skb, dev, &again);
4246                         if (!skb)
4247                                 goto out;
4248
4249                         HARD_TX_LOCK(dev, txq, cpu);
4250
4251                         if (!netif_xmit_stopped(txq)) {
4252                                 dev_xmit_recursion_inc();
4253                                 skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4254                                 dev_xmit_recursion_dec();
4255                                 if (dev_xmit_complete(rc)) {
4256                                         HARD_TX_UNLOCK(dev, txq);
4257                                         goto out;
4258                                 }
4259                         }
4260                         HARD_TX_UNLOCK(dev, txq);
4261                         net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4262                                              dev->name);
4263                 } else {
4264                         /* Recursion is detected! It is possible,
4265                          * unfortunately
4266                          */
4267 recursion_alert:
4268                         net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4269                                              dev->name);
4270                 }
4271         }
4272
4273         rc = -ENETDOWN;
4274         rcu_read_unlock_bh();
4275
4276         dev_core_stats_tx_dropped_inc(dev);
4277         kfree_skb_list(skb);
4278         return rc;
4279 out:
4280         rcu_read_unlock_bh();
4281         return rc;
4282 }
4283 EXPORT_SYMBOL(__dev_queue_xmit);
4284
4285 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4286 {
4287         struct net_device *dev = skb->dev;
4288         struct sk_buff *orig_skb = skb;
4289         struct netdev_queue *txq;
4290         int ret = NETDEV_TX_BUSY;
4291         bool again = false;
4292
4293         if (unlikely(!netif_running(dev) ||
4294                      !netif_carrier_ok(dev)))
4295                 goto drop;
4296
4297         skb = validate_xmit_skb_list(skb, dev, &again);
4298         if (skb != orig_skb)
4299                 goto drop;
4300
4301         skb_set_queue_mapping(skb, queue_id);
4302         txq = skb_get_tx_queue(dev, skb);
4303
4304         local_bh_disable();
4305
4306         dev_xmit_recursion_inc();
4307         HARD_TX_LOCK(dev, txq, smp_processor_id());
4308         if (!netif_xmit_frozen_or_drv_stopped(txq))
4309                 ret = netdev_start_xmit(skb, dev, txq, false);
4310         HARD_TX_UNLOCK(dev, txq);
4311         dev_xmit_recursion_dec();
4312
4313         local_bh_enable();
4314         return ret;
4315 drop:
4316         dev_core_stats_tx_dropped_inc(dev);
4317         kfree_skb_list(skb);
4318         return NET_XMIT_DROP;
4319 }
4320 EXPORT_SYMBOL(__dev_direct_xmit);
4321
4322 /*************************************************************************
4323  *                      Receiver routines
4324  *************************************************************************/
4325
4326 int netdev_max_backlog __read_mostly = 1000;
4327 EXPORT_SYMBOL(netdev_max_backlog);
4328
4329 int netdev_tstamp_prequeue __read_mostly = 1;
4330 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4331 int netdev_budget __read_mostly = 300;
4332 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4333 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4334 int weight_p __read_mostly = 64;           /* old backlog weight */
4335 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4336 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4337 int dev_rx_weight __read_mostly = 64;
4338 int dev_tx_weight __read_mostly = 64;
4339
4340 /* Called with irq disabled */
4341 static inline void ____napi_schedule(struct softnet_data *sd,
4342                                      struct napi_struct *napi)
4343 {
4344         struct task_struct *thread;
4345
4346         lockdep_assert_irqs_disabled();
4347
4348         if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4349                 /* Paired with smp_mb__before_atomic() in
4350                  * napi_enable()/dev_set_threaded().
4351                  * Use READ_ONCE() to guarantee a complete
4352                  * read on napi->thread. Only call
4353                  * wake_up_process() when it's not NULL.
4354                  */
4355                 thread = READ_ONCE(napi->thread);
4356                 if (thread) {
4357                         /* Avoid doing set_bit() if the thread is in
4358                          * INTERRUPTIBLE state, cause napi_thread_wait()
4359                          * makes sure to proceed with napi polling
4360                          * if the thread is explicitly woken from here.
4361                          */
4362                         if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4363                                 set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4364                         wake_up_process(thread);
4365                         return;
4366                 }
4367         }
4368
4369         list_add_tail(&napi->poll_list, &sd->poll_list);
4370         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4371 }
4372
4373 #ifdef CONFIG_RPS
4374
4375 /* One global table that all flow-based protocols share. */
4376 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4377 EXPORT_SYMBOL(rps_sock_flow_table);
4378 u32 rps_cpu_mask __read_mostly;
4379 EXPORT_SYMBOL(rps_cpu_mask);
4380
4381 struct static_key_false rps_needed __read_mostly;
4382 EXPORT_SYMBOL(rps_needed);
4383 struct static_key_false rfs_needed __read_mostly;
4384 EXPORT_SYMBOL(rfs_needed);
4385
4386 static struct rps_dev_flow *
4387 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4388             struct rps_dev_flow *rflow, u16 next_cpu)
4389 {
4390         if (next_cpu < nr_cpu_ids) {
4391 #ifdef CONFIG_RFS_ACCEL
4392                 struct netdev_rx_queue *rxqueue;
4393                 struct rps_dev_flow_table *flow_table;
4394                 struct rps_dev_flow *old_rflow;
4395                 u32 flow_id;
4396                 u16 rxq_index;
4397                 int rc;
4398
4399                 /* Should we steer this flow to a different hardware queue? */
4400                 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4401                     !(dev->features & NETIF_F_NTUPLE))
4402                         goto out;
4403                 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4404                 if (rxq_index == skb_get_rx_queue(skb))
4405                         goto out;
4406
4407                 rxqueue = dev->_rx + rxq_index;
4408                 flow_table = rcu_dereference(rxqueue->rps_flow_table);
4409                 if (!flow_table)
4410                         goto out;
4411                 flow_id = skb_get_hash(skb) & flow_table->mask;
4412                 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4413                                                         rxq_index, flow_id);
4414                 if (rc < 0)
4415                         goto out;
4416                 old_rflow = rflow;
4417                 rflow = &flow_table->flows[flow_id];
4418                 rflow->filter = rc;
4419                 if (old_rflow->filter == rflow->filter)
4420                         old_rflow->filter = RPS_NO_FILTER;
4421         out:
4422 #endif
4423                 rflow->last_qtail =
4424                         per_cpu(softnet_data, next_cpu).input_queue_head;
4425         }
4426
4427         rflow->cpu = next_cpu;
4428         return rflow;
4429 }
4430
4431 /*
4432  * get_rps_cpu is called from netif_receive_skb and returns the target
4433  * CPU from the RPS map of the receiving queue for a given skb.
4434  * rcu_read_lock must be held on entry.
4435  */
4436 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4437                        struct rps_dev_flow **rflowp)
4438 {
4439         const struct rps_sock_flow_table *sock_flow_table;
4440         struct netdev_rx_queue *rxqueue = dev->_rx;
4441         struct rps_dev_flow_table *flow_table;
4442         struct rps_map *map;
4443         int cpu = -1;
4444         u32 tcpu;
4445         u32 hash;
4446
4447         if (skb_rx_queue_recorded(skb)) {
4448                 u16 index = skb_get_rx_queue(skb);
4449
4450                 if (unlikely(index >= dev->real_num_rx_queues)) {
4451                         WARN_ONCE(dev->real_num_rx_queues > 1,
4452                                   "%s received packet on queue %u, but number "
4453                                   "of RX queues is %u\n",
4454                                   dev->name, index, dev->real_num_rx_queues);
4455                         goto done;
4456                 }
4457                 rxqueue += index;
4458         }
4459
4460         /* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4461
4462         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4463         map = rcu_dereference(rxqueue->rps_map);
4464         if (!flow_table && !map)
4465                 goto done;
4466
4467         skb_reset_network_header(skb);
4468         hash = skb_get_hash(skb);
4469         if (!hash)
4470                 goto done;
4471
4472         sock_flow_table = rcu_dereference(rps_sock_flow_table);
4473         if (flow_table && sock_flow_table) {
4474                 struct rps_dev_flow *rflow;
4475                 u32 next_cpu;
4476                 u32 ident;
4477
4478                 /* First check into global flow table if there is a match */
4479                 ident = sock_flow_table->ents[hash & sock_flow_table->mask];
4480                 if ((ident ^ hash) & ~rps_cpu_mask)
4481                         goto try_rps;
4482
4483                 next_cpu = ident & rps_cpu_mask;
4484
4485                 /* OK, now we know there is a match,
4486                  * we can look at the local (per receive queue) flow table
4487                  */
4488                 rflow = &flow_table->flows[hash & flow_table->mask];
4489                 tcpu = rflow->cpu;
4490
4491                 /*
4492                  * If the desired CPU (where last recvmsg was done) is
4493                  * different from current CPU (one in the rx-queue flow
4494                  * table entry), switch if one of the following holds:
4495                  *   - Current CPU is unset (>= nr_cpu_ids).
4496                  *   - Current CPU is offline.
4497                  *   - The current CPU's queue tail has advanced beyond the
4498                  *     last packet that was enqueued using this table entry.
4499                  *     This guarantees that all previous packets for the flow
4500                  *     have been dequeued, thus preserving in order delivery.
4501                  */
4502                 if (unlikely(tcpu != next_cpu) &&
4503                     (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4504                      ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4505                       rflow->last_qtail)) >= 0)) {
4506                         tcpu = next_cpu;
4507                         rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4508                 }
4509
4510                 if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4511                         *rflowp = rflow;
4512                         cpu = tcpu;
4513                         goto done;
4514                 }
4515         }
4516
4517 try_rps:
4518
4519         if (map) {
4520                 tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4521                 if (cpu_online(tcpu)) {
4522                         cpu = tcpu;
4523                         goto done;
4524                 }
4525         }
4526
4527 done:
4528         return cpu;
4529 }
4530
4531 #ifdef CONFIG_RFS_ACCEL
4532
4533 /**
4534  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4535  * @dev: Device on which the filter was set
4536  * @rxq_index: RX queue index
4537  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4538  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4539  *
4540  * Drivers that implement ndo_rx_flow_steer() should periodically call
4541  * this function for each installed filter and remove the filters for
4542  * which it returns %true.
4543  */
4544 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4545                          u32 flow_id, u16 filter_id)
4546 {
4547         struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4548         struct rps_dev_flow_table *flow_table;
4549         struct rps_dev_flow *rflow;
4550         bool expire = true;
4551         unsigned int cpu;
4552
4553         rcu_read_lock();
4554         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4555         if (flow_table && flow_id <= flow_table->mask) {
4556                 rflow = &flow_table->flows[flow_id];
4557                 cpu = READ_ONCE(rflow->cpu);
4558                 if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4559                     ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4560                            rflow->last_qtail) <
4561                      (int)(10 * flow_table->mask)))
4562                         expire = false;
4563         }
4564         rcu_read_unlock();
4565         return expire;
4566 }
4567 EXPORT_SYMBOL(rps_may_expire_flow);
4568
4569 #endif /* CONFIG_RFS_ACCEL */
4570
4571 /* Called from hardirq (IPI) context */
4572 static void rps_trigger_softirq(void *data)
4573 {
4574         struct softnet_data *sd = data;
4575
4576         ____napi_schedule(sd, &sd->backlog);
4577         sd->received_rps++;
4578 }
4579
4580 #endif /* CONFIG_RPS */
4581
4582 /* Called from hardirq (IPI) context */
4583 static void trigger_rx_softirq(void *data)
4584 {
4585         struct softnet_data *sd = data;
4586
4587         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4588         smp_store_release(&sd->defer_ipi_scheduled, 0);
4589 }
4590
4591 /*
4592  * Check if this softnet_data structure is another cpu one
4593  * If yes, queue it to our IPI list and return 1
4594  * If no, return 0
4595  */
4596 static int napi_schedule_rps(struct softnet_data *sd)
4597 {
4598         struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4599
4600 #ifdef CONFIG_RPS
4601         if (sd != mysd) {
4602                 sd->rps_ipi_next = mysd->rps_ipi_list;
4603                 mysd->rps_ipi_list = sd;
4604
4605                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4606                 return 1;
4607         }
4608 #endif /* CONFIG_RPS */
4609         __napi_schedule_irqoff(&mysd->backlog);
4610         return 0;
4611 }
4612
4613 #ifdef CONFIG_NET_FLOW_LIMIT
4614 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4615 #endif
4616
4617 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4618 {
4619 #ifdef CONFIG_NET_FLOW_LIMIT
4620         struct sd_flow_limit *fl;
4621         struct softnet_data *sd;
4622         unsigned int old_flow, new_flow;
4623
4624         if (qlen < (netdev_max_backlog >> 1))
4625                 return false;
4626
4627         sd = this_cpu_ptr(&softnet_data);
4628
4629         rcu_read_lock();
4630         fl = rcu_dereference(sd->flow_limit);
4631         if (fl) {
4632                 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4633                 old_flow = fl->history[fl->history_head];
4634                 fl->history[fl->history_head] = new_flow;
4635
4636                 fl->history_head++;
4637                 fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4638
4639                 if (likely(fl->buckets[old_flow]))
4640                         fl->buckets[old_flow]--;
4641
4642                 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4643                         fl->count++;
4644                         rcu_read_unlock();
4645                         return true;
4646                 }
4647         }
4648         rcu_read_unlock();
4649 #endif
4650         return false;
4651 }
4652
4653 /*
4654  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4655  * queue (may be a remote CPU queue).
4656  */
4657 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4658                               unsigned int *qtail)
4659 {
4660         enum skb_drop_reason reason;
4661         struct softnet_data *sd;
4662         unsigned long flags;
4663         unsigned int qlen;
4664
4665         reason = SKB_DROP_REASON_NOT_SPECIFIED;
4666         sd = &per_cpu(softnet_data, cpu);
4667
4668         rps_lock_irqsave(sd, &flags);
4669         if (!netif_running(skb->dev))
4670                 goto drop;
4671         qlen = skb_queue_len(&sd->input_pkt_queue);
4672         if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
4673                 if (qlen) {
4674 enqueue:
4675                         __skb_queue_tail(&sd->input_pkt_queue, skb);
4676                         input_queue_tail_incr_save(sd, qtail);
4677                         rps_unlock_irq_restore(sd, &flags);
4678                         return NET_RX_SUCCESS;
4679                 }
4680
4681                 /* Schedule NAPI for backlog device
4682                  * We can use non atomic operation since we own the queue lock
4683                  */
4684                 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4685                         napi_schedule_rps(sd);
4686                 goto enqueue;
4687         }
4688         reason = SKB_DROP_REASON_CPU_BACKLOG;
4689
4690 drop:
4691         sd->dropped++;
4692         rps_unlock_irq_restore(sd, &flags);
4693
4694         dev_core_stats_rx_dropped_inc(skb->dev);
4695         kfree_skb_reason(skb, reason);
4696         return NET_RX_DROP;
4697 }
4698
4699 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4700 {
4701         struct net_device *dev = skb->dev;
4702         struct netdev_rx_queue *rxqueue;
4703
4704         rxqueue = dev->_rx;
4705
4706         if (skb_rx_queue_recorded(skb)) {
4707                 u16 index = skb_get_rx_queue(skb);
4708
4709                 if (unlikely(index >= dev->real_num_rx_queues)) {
4710                         WARN_ONCE(dev->real_num_rx_queues > 1,
4711                                   "%s received packet on queue %u, but number "
4712                                   "of RX queues is %u\n",
4713                                   dev->name, index, dev->real_num_rx_queues);
4714
4715                         return rxqueue; /* Return first rxqueue */
4716                 }
4717                 rxqueue += index;
4718         }
4719         return rxqueue;
4720 }
4721
4722 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4723                              struct bpf_prog *xdp_prog)
4724 {
4725         void *orig_data, *orig_data_end, *hard_start;
4726         struct netdev_rx_queue *rxqueue;
4727         bool orig_bcast, orig_host;
4728         u32 mac_len, frame_sz;
4729         __be16 orig_eth_type;
4730         struct ethhdr *eth;
4731         u32 metalen, act;
4732         int off;
4733
4734         /* The XDP program wants to see the packet starting at the MAC
4735          * header.
4736          */
4737         mac_len = skb->data - skb_mac_header(skb);
4738         hard_start = skb->data - skb_headroom(skb);
4739
4740         /* SKB "head" area always have tailroom for skb_shared_info */
4741         frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4742         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4743
4744         rxqueue = netif_get_rxqueue(skb);
4745         xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4746         xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4747                          skb_headlen(skb) + mac_len, true);
4748
4749         orig_data_end = xdp->data_end;
4750         orig_data = xdp->data;
4751         eth = (struct ethhdr *)xdp->data;
4752         orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4753         orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4754         orig_eth_type = eth->h_proto;
4755
4756         act = bpf_prog_run_xdp(xdp_prog, xdp);
4757
4758         /* check if bpf_xdp_adjust_head was used */
4759         off = xdp->data - orig_data;
4760         if (off) {
4761                 if (off > 0)
4762                         __skb_pull(skb, off);
4763                 else if (off < 0)
4764                         __skb_push(skb, -off);
4765
4766                 skb->mac_header += off;
4767                 skb_reset_network_header(skb);
4768         }
4769
4770         /* check if bpf_xdp_adjust_tail was used */
4771         off = xdp->data_end - orig_data_end;
4772         if (off != 0) {
4773                 skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4774                 skb->len += off; /* positive on grow, negative on shrink */
4775         }
4776
4777         /* check if XDP changed eth hdr such SKB needs update */
4778         eth = (struct ethhdr *)xdp->data;
4779         if ((orig_eth_type != eth->h_proto) ||
4780             (orig_host != ether_addr_equal_64bits(eth->h_dest,
4781                                                   skb->dev->dev_addr)) ||
4782             (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4783                 __skb_push(skb, ETH_HLEN);
4784                 skb->pkt_type = PACKET_HOST;
4785                 skb->protocol = eth_type_trans(skb, skb->dev);
4786         }
4787
4788         /* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4789          * before calling us again on redirect path. We do not call do_redirect
4790          * as we leave that up to the caller.
4791          *
4792          * Caller is responsible for managing lifetime of skb (i.e. calling
4793          * kfree_skb in response to actions it cannot handle/XDP_DROP).
4794          */
4795         switch (act) {
4796         case XDP_REDIRECT:
4797         case XDP_TX:
4798                 __skb_push(skb, mac_len);
4799                 break;
4800         case XDP_PASS:
4801                 metalen = xdp->data - xdp->data_meta;
4802                 if (metalen)
4803                         skb_metadata_set(skb, metalen);
4804                 break;
4805         }
4806
4807         return act;
4808 }
4809
4810 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4811                                      struct xdp_buff *xdp,
4812                                      struct bpf_prog *xdp_prog)
4813 {
4814         u32 act = XDP_DROP;
4815
4816         /* Reinjected packets coming from act_mirred or similar should
4817          * not get XDP generic processing.
4818          */
4819         if (skb_is_redirected(skb))
4820                 return XDP_PASS;
4821
4822         /* XDP packets must be linear and must have sufficient headroom
4823          * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4824          * native XDP provides, thus we need to do it here as well.
4825          */
4826         if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4827             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4828                 int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4829                 int troom = skb->tail + skb->data_len - skb->end;
4830
4831                 /* In case we have to go down the path and also linearize,
4832                  * then lets do the pskb_expand_head() work just once here.
4833                  */
4834                 if (pskb_expand_head(skb,
4835                                      hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4836                                      troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4837                         goto do_drop;
4838                 if (skb_linearize(skb))
4839                         goto do_drop;
4840         }
4841
4842         act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4843         switch (act) {
4844         case XDP_REDIRECT:
4845         case XDP_TX:
4846         case XDP_PASS:
4847                 break;
4848         default:
4849                 bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4850                 fallthrough;
4851         case XDP_ABORTED:
4852                 trace_xdp_exception(skb->dev, xdp_prog, act);
4853                 fallthrough;
4854         case XDP_DROP:
4855         do_drop:
4856                 kfree_skb(skb);
4857                 break;
4858         }
4859
4860         return act;
4861 }
4862
4863 /* When doing generic XDP we have to bypass the qdisc layer and the
4864  * network taps in order to match in-driver-XDP behavior.
4865  */
4866 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4867 {
4868         struct net_device *dev = skb->dev;
4869         struct netdev_queue *txq;
4870         bool free_skb = true;
4871         int cpu, rc;
4872
4873         txq = netdev_core_pick_tx(dev, skb, NULL);
4874         cpu = smp_processor_id();
4875         HARD_TX_LOCK(dev, txq, cpu);
4876         if (!netif_xmit_stopped(txq)) {
4877                 rc = netdev_start_xmit(skb, dev, txq, 0);
4878                 if (dev_xmit_complete(rc))
4879                         free_skb = false;
4880         }
4881         HARD_TX_UNLOCK(dev, txq);
4882         if (free_skb) {
4883                 trace_xdp_exception(dev, xdp_prog, XDP_TX);
4884                 kfree_skb(skb);
4885         }
4886 }
4887
4888 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4889
4890 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4891 {
4892         if (xdp_prog) {
4893                 struct xdp_buff xdp;
4894                 u32 act;
4895                 int err;
4896
4897                 act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4898                 if (act != XDP_PASS) {
4899                         switch (act) {
4900                         case XDP_REDIRECT:
4901                                 err = xdp_do_generic_redirect(skb->dev, skb,
4902                                                               &xdp, xdp_prog);
4903                                 if (err)
4904                                         goto out_redir;
4905                                 break;
4906                         case XDP_TX:
4907                                 generic_xdp_tx(skb, xdp_prog);
4908                                 break;
4909                         }
4910                         return XDP_DROP;
4911                 }
4912         }
4913         return XDP_PASS;
4914 out_redir:
4915         kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
4916         return XDP_DROP;
4917 }
4918 EXPORT_SYMBOL_GPL(do_xdp_generic);
4919
4920 static int netif_rx_internal(struct sk_buff *skb)
4921 {
4922         int ret;
4923
4924         net_timestamp_check(netdev_tstamp_prequeue, skb);
4925
4926         trace_netif_rx(skb);
4927
4928 #ifdef CONFIG_RPS
4929         if (static_branch_unlikely(&rps_needed)) {
4930                 struct rps_dev_flow voidflow, *rflow = &voidflow;
4931                 int cpu;
4932
4933                 rcu_read_lock();
4934
4935                 cpu = get_rps_cpu(skb->dev, skb, &rflow);
4936                 if (cpu < 0)
4937                         cpu = smp_processor_id();
4938
4939                 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4940
4941                 rcu_read_unlock();
4942         } else
4943 #endif
4944         {
4945                 unsigned int qtail;
4946
4947                 ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
4948         }
4949         return ret;
4950 }
4951
4952 /**
4953  *      __netif_rx      -       Slightly optimized version of netif_rx
4954  *      @skb: buffer to post
4955  *
4956  *      This behaves as netif_rx except that it does not disable bottom halves.
4957  *      As a result this function may only be invoked from the interrupt context
4958  *      (either hard or soft interrupt).
4959  */
4960 int __netif_rx(struct sk_buff *skb)
4961 {
4962         int ret;
4963
4964         lockdep_assert_once(hardirq_count() | softirq_count());
4965
4966         trace_netif_rx_entry(skb);
4967         ret = netif_rx_internal(skb);
4968         trace_netif_rx_exit(ret);
4969         return ret;
4970 }
4971 EXPORT_SYMBOL(__netif_rx);
4972
4973 /**
4974  *      netif_rx        -       post buffer to the network code
4975  *      @skb: buffer to post
4976  *
4977  *      This function receives a packet from a device driver and queues it for
4978  *      the upper (protocol) levels to process via the backlog NAPI device. It
4979  *      always succeeds. The buffer may be dropped during processing for
4980  *      congestion control or by the protocol layers.
4981  *      The network buffer is passed via the backlog NAPI device. Modern NIC
4982  *      driver should use NAPI and GRO.
4983  *      This function can used from interrupt and from process context. The
4984  *      caller from process context must not disable interrupts before invoking
4985  *      this function.
4986  *
4987  *      return values:
4988  *      NET_RX_SUCCESS  (no congestion)
4989  *      NET_RX_DROP     (packet was dropped)
4990  *
4991  */
4992 int netif_rx(struct sk_buff *skb)
4993 {
4994         bool need_bh_off = !(hardirq_count() | softirq_count());
4995         int ret;
4996
4997         if (need_bh_off)
4998                 local_bh_disable();
4999         trace_netif_rx_entry(skb);
5000         ret = netif_rx_internal(skb);
5001         trace_netif_rx_exit(ret);
5002         if (need_bh_off)
5003                 local_bh_enable();
5004         return ret;
5005 }
5006 EXPORT_SYMBOL(netif_rx);
5007
5008 static __latent_entropy void net_tx_action(struct softirq_action *h)
5009 {
5010         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5011
5012         if (sd->completion_queue) {
5013                 struct sk_buff *clist;
5014
5015                 local_irq_disable();
5016                 clist = sd->completion_queue;
5017                 sd->completion_queue = NULL;
5018                 local_irq_enable();
5019
5020                 while (clist) {
5021                         struct sk_buff *skb = clist;
5022
5023                         clist = clist->next;
5024
5025                         WARN_ON(refcount_read(&skb->users));
5026                         if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
5027                                 trace_consume_skb(skb);
5028                         else
5029                                 trace_kfree_skb(skb, net_tx_action,
5030                                                 SKB_DROP_REASON_NOT_SPECIFIED);
5031
5032                         if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5033                                 __kfree_skb(skb);
5034                         else
5035                                 __kfree_skb_defer(skb);
5036                 }
5037         }
5038
5039         if (sd->output_queue) {
5040                 struct Qdisc *head;
5041
5042                 local_irq_disable();
5043                 head = sd->output_queue;
5044                 sd->output_queue = NULL;
5045                 sd->output_queue_tailp = &sd->output_queue;
5046                 local_irq_enable();
5047
5048                 rcu_read_lock();
5049
5050                 while (head) {
5051                         struct Qdisc *q = head;
5052                         spinlock_t *root_lock = NULL;
5053
5054                         head = head->next_sched;
5055
5056                         /* We need to make sure head->next_sched is read
5057                          * before clearing __QDISC_STATE_SCHED
5058                          */
5059                         smp_mb__before_atomic();
5060
5061                         if (!(q->flags & TCQ_F_NOLOCK)) {
5062                                 root_lock = qdisc_lock(q);
5063                                 spin_lock(root_lock);
5064                         } else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5065                                                      &q->state))) {
5066                                 /* There is a synchronize_net() between
5067                                  * STATE_DEACTIVATED flag being set and
5068                                  * qdisc_reset()/some_qdisc_is_busy() in
5069                                  * dev_deactivate(), so we can safely bail out
5070                                  * early here to avoid data race between
5071                                  * qdisc_deactivate() and some_qdisc_is_busy()
5072                                  * for lockless qdisc.
5073                                  */
5074                                 clear_bit(__QDISC_STATE_SCHED, &q->state);
5075                                 continue;
5076                         }
5077
5078                         clear_bit(__QDISC_STATE_SCHED, &q->state);
5079                         qdisc_run(q);
5080                         if (root_lock)
5081                                 spin_unlock(root_lock);
5082                 }
5083
5084                 rcu_read_unlock();
5085         }
5086
5087         xfrm_dev_backlog(sd);
5088 }
5089
5090 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5091 /* This hook is defined here for ATM LANE */
5092 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5093                              unsigned char *addr) __read_mostly;
5094 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5095 #endif
5096
5097 static inline struct sk_buff *
5098 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5099                    struct net_device *orig_dev, bool *another)
5100 {
5101 #ifdef CONFIG_NET_CLS_ACT
5102         struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5103         struct tcf_result cl_res;
5104
5105         /* If there's at least one ingress present somewhere (so
5106          * we get here via enabled static key), remaining devices
5107          * that are not configured with an ingress qdisc will bail
5108          * out here.
5109          */
5110         if (!miniq)
5111                 return skb;
5112
5113         if (*pt_prev) {
5114                 *ret = deliver_skb(skb, *pt_prev, orig_dev);
5115                 *pt_prev = NULL;
5116         }
5117
5118         qdisc_skb_cb(skb)->pkt_len = skb->len;
5119         tc_skb_cb(skb)->mru = 0;
5120         tc_skb_cb(skb)->post_ct = false;
5121         skb->tc_at_ingress = 1;
5122         mini_qdisc_bstats_cpu_update(miniq, skb);
5123
5124         switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5125         case TC_ACT_OK:
5126         case TC_ACT_RECLASSIFY:
5127                 skb->tc_index = TC_H_MIN(cl_res.classid);
5128                 break;
5129         case TC_ACT_SHOT:
5130                 mini_qdisc_qstats_cpu_drop(miniq);
5131                 kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
5132                 return NULL;
5133         case TC_ACT_STOLEN:
5134         case TC_ACT_QUEUED:
5135         case TC_ACT_TRAP:
5136                 consume_skb(skb);
5137                 return NULL;
5138         case TC_ACT_REDIRECT:
5139                 /* skb_mac_header check was done by cls/act_bpf, so
5140                  * we can safely push the L2 header back before
5141                  * redirecting to another netdev
5142                  */
5143                 __skb_push(skb, skb->mac_len);
5144                 if (skb_do_redirect(skb) == -EAGAIN) {
5145                         __skb_pull(skb, skb->mac_len);
5146                         *another = true;
5147                         break;
5148                 }
5149                 return NULL;
5150         case TC_ACT_CONSUMED:
5151                 return NULL;
5152         default:
5153                 break;
5154         }
5155 #endif /* CONFIG_NET_CLS_ACT */
5156         return skb;
5157 }
5158
5159 /**
5160  *      netdev_is_rx_handler_busy - check if receive handler is registered
5161  *      @dev: device to check
5162  *
5163  *      Check if a receive handler is already registered for a given device.
5164  *      Return true if there one.
5165  *
5166  *      The caller must hold the rtnl_mutex.
5167  */
5168 bool netdev_is_rx_handler_busy(struct net_device *dev)
5169 {
5170         ASSERT_RTNL();
5171         return dev && rtnl_dereference(dev->rx_handler);
5172 }
5173 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5174
5175 /**
5176  *      netdev_rx_handler_register - register receive handler
5177  *      @dev: device to register a handler for
5178  *      @rx_handler: receive handler to register
5179  *      @rx_handler_data: data pointer that is used by rx handler
5180  *
5181  *      Register a receive handler for a device. This handler will then be
5182  *      called from __netif_receive_skb. A negative errno code is returned
5183  *      on a failure.
5184  *
5185  *      The caller must hold the rtnl_mutex.
5186  *
5187  *      For a general description of rx_handler, see enum rx_handler_result.
5188  */
5189 int netdev_rx_handler_register(struct net_device *dev,
5190                                rx_handler_func_t *rx_handler,
5191                                void *rx_handler_data)
5192 {
5193         if (netdev_is_rx_handler_busy(dev))
5194                 return -EBUSY;
5195
5196         if (dev->priv_flags & IFF_NO_RX_HANDLER)
5197                 return -EINVAL;
5198
5199         /* Note: rx_handler_data must be set before rx_handler */
5200         rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5201         rcu_assign_pointer(dev->rx_handler, rx_handler);
5202
5203         return 0;
5204 }
5205 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5206
5207 /**
5208  *      netdev_rx_handler_unregister - unregister receive handler
5209  *      @dev: device to unregister a handler from
5210  *
5211  *      Unregister a receive handler from a device.
5212  *
5213  *      The caller must hold the rtnl_mutex.
5214  */
5215 void netdev_rx_handler_unregister(struct net_device *dev)
5216 {
5217
5218         ASSERT_RTNL();
5219         RCU_INIT_POINTER(dev->rx_handler, NULL);
5220         /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5221          * section has a guarantee to see a non NULL rx_handler_data
5222          * as well.
5223          */
5224         synchronize_net();
5225         RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5226 }
5227 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5228
5229 /*
5230  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5231  * the special handling of PFMEMALLOC skbs.
5232  */
5233 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5234 {
5235         switch (skb->protocol) {
5236         case htons(ETH_P_ARP):
5237         case htons(ETH_P_IP):
5238         case htons(ETH_P_IPV6):
5239         case htons(ETH_P_8021Q):
5240         case htons(ETH_P_8021AD):
5241                 return true;
5242         default:
5243                 return false;
5244         }
5245 }
5246
5247 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5248                              int *ret, struct net_device *orig_dev)
5249 {
5250         if (nf_hook_ingress_active(skb)) {
5251                 int ingress_retval;
5252
5253                 if (*pt_prev) {
5254                         *ret = deliver_skb(skb, *pt_prev, orig_dev);
5255                         *pt_prev = NULL;
5256                 }
5257
5258                 rcu_read_lock();
5259                 ingress_retval = nf_hook_ingress(skb);
5260                 rcu_read_unlock();
5261                 return ingress_retval;
5262         }
5263         return 0;
5264 }
5265
5266 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5267                                     struct packet_type **ppt_prev)
5268 {
5269         struct packet_type *ptype, *pt_prev;
5270         rx_handler_func_t *rx_handler;
5271         struct sk_buff *skb = *pskb;
5272         struct net_device *orig_dev;
5273         bool deliver_exact = false;
5274         int ret = NET_RX_DROP;
5275         __be16 type;
5276
5277         net_timestamp_check(!netdev_tstamp_prequeue, skb);
5278
5279         trace_netif_receive_skb(skb);
5280
5281         orig_dev = skb->dev;
5282
5283         skb_reset_network_header(skb);
5284         if (!skb_transport_header_was_set(skb))
5285                 skb_reset_transport_header(skb);
5286         skb_reset_mac_len(skb);
5287
5288         pt_prev = NULL;
5289
5290 another_round:
5291         skb->skb_iif = skb->dev->ifindex;
5292
5293         __this_cpu_inc(softnet_data.processed);
5294
5295         if (static_branch_unlikely(&generic_xdp_needed_key)) {
5296                 int ret2;
5297
5298                 migrate_disable();
5299                 ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5300                 migrate_enable();
5301
5302                 if (ret2 != XDP_PASS) {
5303                         ret = NET_RX_DROP;
5304                         goto out;
5305                 }
5306         }
5307
5308         if (eth_type_vlan(skb->protocol)) {
5309                 skb = skb_vlan_untag(skb);
5310                 if (unlikely(!skb))
5311                         goto out;
5312         }
5313
5314         if (skb_skip_tc_classify(skb))
5315                 goto skip_classify;
5316
5317         if (pfmemalloc)
5318                 goto skip_taps;
5319
5320         list_for_each_entry_rcu(ptype, &ptype_all, list) {
5321                 if (pt_prev)
5322                         ret = deliver_skb(skb, pt_prev, orig_dev);
5323                 pt_prev = ptype;
5324         }
5325
5326         list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5327                 if (pt_prev)
5328                         ret = deliver_skb(skb, pt_prev, orig_dev);
5329                 pt_prev = ptype;
5330         }
5331
5332 skip_taps:
5333 #ifdef CONFIG_NET_INGRESS
5334         if (static_branch_unlikely(&ingress_needed_key)) {
5335                 bool another = false;
5336
5337                 nf_skip_egress(skb, true);
5338                 skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5339                                          &another);
5340                 if (another)
5341                         goto another_round;
5342                 if (!skb)
5343                         goto out;
5344
5345                 nf_skip_egress(skb, false);
5346                 if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5347                         goto out;
5348         }
5349 #endif
5350         skb_reset_redirect(skb);
5351 skip_classify:
5352         if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5353                 goto drop;
5354
5355         if (skb_vlan_tag_present(skb)) {
5356                 if (pt_prev) {
5357                         ret = deliver_skb(skb, pt_prev, orig_dev);
5358                         pt_prev = NULL;
5359                 }
5360                 if (vlan_do_receive(&skb))
5361                         goto another_round;
5362                 else if (unlikely(!skb))
5363                         goto out;
5364         }
5365
5366         rx_handler = rcu_dereference(skb->dev->rx_handler);
5367         if (rx_handler) {
5368                 if (pt_prev) {
5369                         ret = deliver_skb(skb, pt_prev, orig_dev);
5370                         pt_prev = NULL;
5371                 }
5372                 switch (rx_handler(&skb)) {
5373                 case RX_HANDLER_CONSUMED:
5374                         ret = NET_RX_SUCCESS;
5375                         goto out;
5376                 case RX_HANDLER_ANOTHER:
5377                         goto another_round;
5378                 case RX_HANDLER_EXACT:
5379                         deliver_exact = true;
5380                         break;
5381                 case RX_HANDLER_PASS:
5382                         break;
5383                 default:
5384                         BUG();
5385                 }
5386         }
5387
5388         if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5389 check_vlan_id:
5390                 if (skb_vlan_tag_get_id(skb)) {
5391                         /* Vlan id is non 0 and vlan_do_receive() above couldn't
5392                          * find vlan device.
5393                          */
5394                         skb->pkt_type = PACKET_OTHERHOST;
5395                 } else if (eth_type_vlan(skb->protocol)) {
5396                         /* Outer header is 802.1P with vlan 0, inner header is
5397                          * 802.1Q or 802.1AD and vlan_do_receive() above could
5398                          * not find vlan dev for vlan id 0.
5399                          */
5400                         __vlan_hwaccel_clear_tag(skb);
5401                         skb = skb_vlan_untag(skb);
5402                         if (unlikely(!skb))
5403                                 goto out;
5404                         if (vlan_do_receive(&skb))
5405                                 /* After stripping off 802.1P header with vlan 0
5406                                  * vlan dev is found for inner header.
5407                                  */
5408                                 goto another_round;
5409                         else if (unlikely(!skb))
5410                                 goto out;
5411                         else
5412                                 /* We have stripped outer 802.1P vlan 0 header.
5413                                  * But could not find vlan dev.
5414                                  * check again for vlan id to set OTHERHOST.
5415                                  */
5416                                 goto check_vlan_id;
5417                 }
5418                 /* Note: we might in the future use prio bits
5419                  * and set skb->priority like in vlan_do_receive()
5420                  * For the time being, just ignore Priority Code Point
5421                  */
5422                 __vlan_hwaccel_clear_tag(skb);
5423         }
5424
5425         type = skb->protocol;
5426
5427         /* deliver only exact match when indicated */
5428         if (likely(!deliver_exact)) {
5429                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5430                                        &ptype_base[ntohs(type) &
5431                                                    PTYPE_HASH_MASK]);
5432         }
5433
5434         deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5435                                &orig_dev->ptype_specific);
5436
5437         if (unlikely(skb->dev != orig_dev)) {
5438                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5439                                        &skb->dev->ptype_specific);
5440         }
5441
5442         if (pt_prev) {
5443                 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5444                         goto drop;
5445                 *ppt_prev = pt_prev;
5446         } else {
5447 drop:
5448                 if (!deliver_exact)
5449                         dev_core_stats_rx_dropped_inc(skb->dev);
5450                 else
5451                         dev_core_stats_rx_nohandler_inc(skb->dev);
5452                 kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5453                 /* Jamal, now you will not able to escape explaining
5454                  * me how you were going to use this. :-)
5455                  */
5456                 ret = NET_RX_DROP;
5457         }
5458
5459 out:
5460         /* The invariant here is that if *ppt_prev is not NULL
5461          * then skb should also be non-NULL.
5462          *
5463          * Apparently *ppt_prev assignment above holds this invariant due to
5464          * skb dereferencing near it.
5465          */
5466         *pskb = skb;
5467         return ret;
5468 }
5469
5470 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5471 {
5472         struct net_device *orig_dev = skb->dev;
5473         struct packet_type *pt_prev = NULL;
5474         int ret;
5475
5476         ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5477         if (pt_prev)
5478                 ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5479                                          skb->dev, pt_prev, orig_dev);
5480         return ret;
5481 }
5482
5483 /**
5484  *      netif_receive_skb_core - special purpose version of netif_receive_skb
5485  *      @skb: buffer to process
5486  *
5487  *      More direct receive version of netif_receive_skb().  It should
5488  *      only be used by callers that have a need to skip RPS and Generic XDP.
5489  *      Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5490  *
5491  *      This function may only be called from softirq context and interrupts
5492  *      should be enabled.
5493  *
5494  *      Return values (usually ignored):
5495  *      NET_RX_SUCCESS: no congestion
5496  *      NET_RX_DROP: packet was dropped
5497  */
5498 int netif_receive_skb_core(struct sk_buff *skb)
5499 {
5500         int ret;
5501
5502         rcu_read_lock();
5503         ret = __netif_receive_skb_one_core(skb, false);
5504         rcu_read_unlock();
5505
5506         return ret;
5507 }
5508 EXPORT_SYMBOL(netif_receive_skb_core);
5509
5510 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5511                                                   struct packet_type *pt_prev,
5512                                                   struct net_device *orig_dev)
5513 {
5514         struct sk_buff *skb, *next;
5515
5516         if (!pt_prev)
5517                 return;
5518         if (list_empty(head))
5519                 return;
5520         if (pt_prev->list_func != NULL)
5521                 INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5522                                    ip_list_rcv, head, pt_prev, orig_dev);
5523         else
5524                 list_for_each_entry_safe(skb, next, head, list) {
5525                         skb_list_del_init(skb);
5526                         pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5527                 }
5528 }
5529
5530 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5531 {
5532         /* Fast-path assumptions:
5533          * - There is no RX handler.
5534          * - Only one packet_type matches.
5535          * If either of these fails, we will end up doing some per-packet
5536          * processing in-line, then handling the 'last ptype' for the whole
5537          * sublist.  This can't cause out-of-order delivery to any single ptype,
5538          * because the 'last ptype' must be constant across the sublist, and all
5539          * other ptypes are handled per-packet.
5540          */
5541         /* Current (common) ptype of sublist */
5542         struct packet_type *pt_curr = NULL;
5543         /* Current (common) orig_dev of sublist */
5544         struct net_device *od_curr = NULL;
5545         struct list_head sublist;
5546         struct sk_buff *skb, *next;
5547
5548         INIT_LIST_HEAD(&sublist);
5549         list_for_each_entry_safe(skb, next, head, list) {
5550                 struct net_device *orig_dev = skb->dev;
5551                 struct packet_type *pt_prev = NULL;
5552
5553                 skb_list_del_init(skb);
5554                 __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5555                 if (!pt_prev)
5556                         continue;
5557                 if (pt_curr != pt_prev || od_curr != orig_dev) {
5558                         /* dispatch old sublist */
5559                         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5560                         /* start new sublist */
5561                         INIT_LIST_HEAD(&sublist);
5562                         pt_curr = pt_prev;
5563                         od_curr = orig_dev;
5564                 }
5565                 list_add_tail(&skb->list, &sublist);
5566         }
5567
5568         /* dispatch final sublist */
5569         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5570 }
5571
5572 static int __netif_receive_skb(struct sk_buff *skb)
5573 {
5574         int ret;
5575
5576         if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5577                 unsigned int noreclaim_flag;
5578
5579                 /*
5580                  * PFMEMALLOC skbs are special, they should
5581                  * - be delivered to SOCK_MEMALLOC sockets only
5582                  * - stay away from userspace
5583                  * - have bounded memory usage
5584                  *
5585                  * Use PF_MEMALLOC as this saves us from propagating the allocation
5586                  * context down to all allocation sites.
5587                  */
5588                 noreclaim_flag = memalloc_noreclaim_save();
5589                 ret = __netif_receive_skb_one_core(skb, true);
5590                 memalloc_noreclaim_restore(noreclaim_flag);
5591         } else
5592                 ret = __netif_receive_skb_one_core(skb, false);
5593
5594         return ret;
5595 }
5596
5597 static void __netif_receive_skb_list(struct list_head *head)
5598 {
5599         unsigned long noreclaim_flag = 0;
5600         struct sk_buff *skb, *next;
5601         bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5602
5603         list_for_each_entry_safe(skb, next, head, list) {
5604                 if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5605                         struct list_head sublist;
5606
5607                         /* Handle the previous sublist */
5608                         list_cut_before(&sublist, head, &skb->list);
5609                         if (!list_empty(&sublist))
5610                                 __netif_receive_skb_list_core(&sublist, pfmemalloc);
5611                         pfmemalloc = !pfmemalloc;
5612                         /* See comments in __netif_receive_skb */
5613                         if (pfmemalloc)
5614                                 noreclaim_flag = memalloc_noreclaim_save();
5615                         else
5616                                 memalloc_noreclaim_restore(noreclaim_flag);
5617                 }
5618         }
5619         /* Handle the remaining sublist */
5620         if (!list_empty(head))
5621                 __netif_receive_skb_list_core(head, pfmemalloc);
5622         /* Restore pflags */
5623         if (pfmemalloc)
5624                 memalloc_noreclaim_restore(noreclaim_flag);
5625 }
5626
5627 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5628 {
5629         struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5630         struct bpf_prog *new = xdp->prog;
5631         int ret = 0;
5632
5633         switch (xdp->command) {
5634         case XDP_SETUP_PROG:
5635                 rcu_assign_pointer(dev->xdp_prog, new);
5636                 if (old)
5637                         bpf_prog_put(old);
5638
5639                 if (old && !new) {
5640                         static_branch_dec(&generic_xdp_needed_key);
5641                 } else if (new && !old) {
5642                         static_branch_inc(&generic_xdp_needed_key);
5643                         dev_disable_lro(dev);
5644                         dev_disable_gro_hw(dev);
5645                 }
5646                 break;
5647
5648         default:
5649                 ret = -EINVAL;
5650                 break;
5651         }
5652
5653         return ret;
5654 }
5655
5656 static int netif_receive_skb_internal(struct sk_buff *skb)
5657 {
5658         int ret;
5659
5660         net_timestamp_check(netdev_tstamp_prequeue, skb);
5661
5662         if (skb_defer_rx_timestamp(skb))
5663                 return NET_RX_SUCCESS;
5664
5665         rcu_read_lock();
5666 #ifdef CONFIG_RPS
5667         if (static_branch_unlikely(&rps_needed)) {
5668                 struct rps_dev_flow voidflow, *rflow = &voidflow;
5669                 int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5670
5671                 if (cpu >= 0) {
5672                         ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5673                         rcu_read_unlock();
5674                         return ret;
5675                 }
5676         }
5677 #endif
5678         ret = __netif_receive_skb(skb);
5679         rcu_read_unlock();
5680         return ret;
5681 }
5682
5683 void netif_receive_skb_list_internal(struct list_head *head)
5684 {
5685         struct sk_buff *skb, *next;
5686         struct list_head sublist;
5687
5688         INIT_LIST_HEAD(&sublist);
5689         list_for_each_entry_safe(skb, next, head, list) {
5690                 net_timestamp_check(netdev_tstamp_prequeue, skb);
5691                 skb_list_del_init(skb);
5692                 if (!skb_defer_rx_timestamp(skb))
5693                         list_add_tail(&skb->list, &sublist);
5694         }
5695         list_splice_init(&sublist, head);
5696
5697         rcu_read_lock();
5698 #ifdef CONFIG_RPS
5699         if (static_branch_unlikely(&rps_needed)) {
5700                 list_for_each_entry_safe(skb, next, head, list) {
5701                         struct rps_dev_flow voidflow, *rflow = &voidflow;
5702                         int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5703
5704                         if (cpu >= 0) {
5705                                 /* Will be handled, remove from list */
5706                                 skb_list_del_init(skb);
5707                                 enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5708                         }
5709                 }
5710         }
5711 #endif
5712         __netif_receive_skb_list(head);
5713         rcu_read_unlock();
5714 }
5715
5716 /**
5717  *      netif_receive_skb - process receive buffer from network
5718  *      @skb: buffer to process
5719  *
5720  *      netif_receive_skb() is the main receive data processing function.
5721  *      It always succeeds. The buffer may be dropped during processing
5722  *      for congestion control or by the protocol layers.
5723  *
5724  *      This function may only be called from softirq context and interrupts
5725  *      should be enabled.
5726  *
5727  *      Return values (usually ignored):
5728  *      NET_RX_SUCCESS: no congestion
5729  *      NET_RX_DROP: packet was dropped
5730  */
5731 int netif_receive_skb(struct sk_buff *skb)
5732 {
5733         int ret;
5734
5735         trace_netif_receive_skb_entry(skb);
5736
5737         ret = netif_receive_skb_internal(skb);
5738         trace_netif_receive_skb_exit(ret);
5739
5740         return ret;
5741 }
5742 EXPORT_SYMBOL(netif_receive_skb);
5743
5744 /**
5745  *      netif_receive_skb_list - process many receive buffers from network
5746  *      @head: list of skbs to process.
5747  *
5748  *      Since return value of netif_receive_skb() is normally ignored, and
5749  *      wouldn't be meaningful for a list, this function returns void.
5750  *
5751  *      This function may only be called from softirq context and interrupts
5752  *      should be enabled.
5753  */
5754 void netif_receive_skb_list(struct list_head *head)
5755 {
5756         struct sk_buff *skb;
5757
5758         if (list_empty(head))
5759                 return;
5760         if (trace_netif_receive_skb_list_entry_enabled()) {
5761                 list_for_each_entry(skb, head, list)
5762                         trace_netif_receive_skb_list_entry(skb);
5763         }
5764         netif_receive_skb_list_internal(head);
5765         trace_netif_receive_skb_list_exit(0);
5766 }
5767 EXPORT_SYMBOL(netif_receive_skb_list);
5768
5769 static DEFINE_PER_CPU(struct work_struct, flush_works);
5770
5771 /* Network device is going away, flush any packets still pending */
5772 static void flush_backlog(struct work_struct *work)
5773 {
5774         struct sk_buff *skb, *tmp;
5775         struct softnet_data *sd;
5776
5777         local_bh_disable();
5778         sd = this_cpu_ptr(&softnet_data);
5779
5780         rps_lock_irq_disable(sd);
5781         skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5782                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5783                         __skb_unlink(skb, &sd->input_pkt_queue);
5784                         dev_kfree_skb_irq(skb);
5785                         input_queue_head_incr(sd);
5786                 }
5787         }
5788         rps_unlock_irq_enable(sd);
5789
5790         skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5791                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5792                         __skb_unlink(skb, &sd->process_queue);
5793                         kfree_skb(skb);
5794                         input_queue_head_incr(sd);
5795                 }
5796         }
5797         local_bh_enable();
5798 }
5799
5800 static bool flush_required(int cpu)
5801 {
5802 #if IS_ENABLED(CONFIG_RPS)
5803         struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5804         bool do_flush;
5805
5806         rps_lock_irq_disable(sd);
5807
5808         /* as insertion into process_queue happens with the rps lock held,
5809          * process_queue access may race only with dequeue
5810          */
5811         do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5812                    !skb_queue_empty_lockless(&sd->process_queue);
5813         rps_unlock_irq_enable(sd);
5814
5815         return do_flush;
5816 #endif
5817         /* without RPS we can't safely check input_pkt_queue: during a
5818          * concurrent remote skb_queue_splice() we can detect as empty both
5819          * input_pkt_queue and process_queue even if the latter could end-up
5820          * containing a lot of packets.
5821          */
5822         return true;
5823 }
5824
5825 static void flush_all_backlogs(void)
5826 {
5827         static cpumask_t flush_cpus;
5828         unsigned int cpu;
5829
5830         /* since we are under rtnl lock protection we can use static data
5831          * for the cpumask and avoid allocating on stack the possibly
5832          * large mask
5833          */
5834         ASSERT_RTNL();
5835
5836         cpus_read_lock();
5837
5838         cpumask_clear(&flush_cpus);
5839         for_each_online_cpu(cpu) {
5840                 if (flush_required(cpu)) {
5841                         queue_work_on(cpu, system_highpri_wq,
5842                                       per_cpu_ptr(&flush_works, cpu));
5843                         cpumask_set_cpu(cpu, &flush_cpus);
5844                 }
5845         }
5846
5847         /* we can have in flight packet[s] on the cpus we are not flushing,
5848          * synchronize_net() in unregister_netdevice_many() will take care of
5849          * them
5850          */
5851         for_each_cpu(cpu, &flush_cpus)
5852                 flush_work(per_cpu_ptr(&flush_works, cpu));
5853
5854         cpus_read_unlock();
5855 }
5856
5857 static void net_rps_send_ipi(struct softnet_data *remsd)
5858 {
5859 #ifdef CONFIG_RPS
5860         while (remsd) {
5861                 struct softnet_data *next = remsd->rps_ipi_next;
5862
5863                 if (cpu_online(remsd->cpu))
5864                         smp_call_function_single_async(remsd->cpu, &remsd->csd);
5865                 remsd = next;
5866         }
5867 #endif
5868 }
5869
5870 /*
5871  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5872  * Note: called with local irq disabled, but exits with local irq enabled.
5873  */
5874 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5875 {
5876 #ifdef CONFIG_RPS
5877         struct softnet_data *remsd = sd->rps_ipi_list;
5878
5879         if (remsd) {
5880                 sd->rps_ipi_list = NULL;
5881
5882                 local_irq_enable();
5883
5884                 /* Send pending IPI's to kick RPS processing on remote cpus. */
5885                 net_rps_send_ipi(remsd);
5886         } else
5887 #endif
5888                 local_irq_enable();
5889 }
5890
5891 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5892 {
5893 #ifdef CONFIG_RPS
5894         return sd->rps_ipi_list != NULL;
5895 #else
5896         return false;
5897 #endif
5898 }
5899
5900 static int process_backlog(struct napi_struct *napi, int quota)
5901 {
5902         struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5903         bool again = true;
5904         int work = 0;
5905
5906         /* Check if we have pending ipi, its better to send them now,
5907          * not waiting net_rx_action() end.
5908          */
5909         if (sd_has_rps_ipi_waiting(sd)) {
5910                 local_irq_disable();
5911                 net_rps_action_and_irq_enable(sd);
5912         }
5913
5914         napi->weight = dev_rx_weight;
5915         while (again) {
5916                 struct sk_buff *skb;
5917
5918                 while ((skb = __skb_dequeue(&sd->process_queue))) {
5919                         rcu_read_lock();
5920                         __netif_receive_skb(skb);
5921                         rcu_read_unlock();
5922                         input_queue_head_incr(sd);
5923                         if (++work >= quota)
5924                                 return work;
5925
5926                 }
5927
5928                 rps_lock_irq_disable(sd);
5929                 if (skb_queue_empty(&sd->input_pkt_queue)) {
5930                         /*
5931                          * Inline a custom version of __napi_complete().
5932                          * only current cpu owns and manipulates this napi,
5933                          * and NAPI_STATE_SCHED is the only possible flag set
5934                          * on backlog.
5935                          * We can use a plain write instead of clear_bit(),
5936                          * and we dont need an smp_mb() memory barrier.
5937                          */
5938                         napi->state = 0;
5939                         again = false;
5940                 } else {
5941                         skb_queue_splice_tail_init(&sd->input_pkt_queue,
5942                                                    &sd->process_queue);
5943                 }
5944                 rps_unlock_irq_enable(sd);
5945         }
5946
5947         return work;
5948 }
5949
5950 /**
5951  * __napi_schedule - schedule for receive
5952  * @n: entry to schedule
5953  *
5954  * The entry's receive function will be scheduled to run.
5955  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5956  */
5957 void __napi_schedule(struct napi_struct *n)
5958 {
5959         unsigned long flags;
5960
5961         local_irq_save(flags);
5962         ____napi_schedule(this_cpu_ptr(&softnet_data), n);
5963         local_irq_restore(flags);
5964 }
5965 EXPORT_SYMBOL(__napi_schedule);
5966
5967 /**
5968  *      napi_schedule_prep - check if napi can be scheduled
5969  *      @n: napi context
5970  *
5971  * Test if NAPI routine is already running, and if not mark
5972  * it as running.  This is used as a condition variable to
5973  * insure only one NAPI poll instance runs.  We also make
5974  * sure there is no pending NAPI disable.
5975  */
5976 bool napi_schedule_prep(struct napi_struct *n)
5977 {
5978         unsigned long val, new;
5979
5980         do {
5981                 val = READ_ONCE(n->state);
5982                 if (unlikely(val & NAPIF_STATE_DISABLE))
5983                         return false;
5984                 new = val | NAPIF_STATE_SCHED;
5985
5986                 /* Sets STATE_MISSED bit if STATE_SCHED was already set
5987                  * This was suggested by Alexander Duyck, as compiler
5988                  * emits better code than :
5989                  * if (val & NAPIF_STATE_SCHED)
5990                  *     new |= NAPIF_STATE_MISSED;
5991                  */
5992                 new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
5993                                                    NAPIF_STATE_MISSED;
5994         } while (cmpxchg(&n->state, val, new) != val);
5995
5996         return !(val & NAPIF_STATE_SCHED);
5997 }
5998 EXPORT_SYMBOL(napi_schedule_prep);
5999
6000 /**
6001  * __napi_schedule_irqoff - schedule for receive
6002  * @n: entry to schedule
6003  *
6004  * Variant of __napi_schedule() assuming hard irqs are masked.
6005  *
6006  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6007  * because the interrupt disabled assumption might not be true
6008  * due to force-threaded interrupts and spinlock substitution.
6009  */
6010 void __napi_schedule_irqoff(struct napi_struct *n)
6011 {
6012         if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6013                 ____napi_schedule(this_cpu_ptr(&softnet_data), n);
6014         else
6015                 __napi_schedule(n);
6016 }
6017 EXPORT_SYMBOL(__napi_schedule_irqoff);
6018
6019 bool napi_complete_done(struct napi_struct *n, int work_done)
6020 {
6021         unsigned long flags, val, new, timeout = 0;
6022         bool ret = true;
6023
6024         /*
6025          * 1) Don't let napi dequeue from the cpu poll list
6026          *    just in case its running on a different cpu.
6027          * 2) If we are busy polling, do nothing here, we have
6028          *    the guarantee we will be called later.
6029          */
6030         if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6031                                  NAPIF_STATE_IN_BUSY_POLL)))
6032                 return false;
6033
6034         if (work_done) {
6035                 if (n->gro_bitmask)
6036                         timeout = READ_ONCE(n->dev->gro_flush_timeout);
6037                 n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6038         }
6039         if (n->defer_hard_irqs_count > 0) {
6040                 n->defer_hard_irqs_count--;
6041                 timeout = READ_ONCE(n->dev->gro_flush_timeout);
6042                 if (timeout)
6043                         ret = false;
6044         }
6045         if (n->gro_bitmask) {
6046                 /* When the NAPI instance uses a timeout and keeps postponing
6047                  * it, we need to bound somehow the time packets are kept in
6048                  * the GRO layer
6049                  */
6050                 napi_gro_flush(n, !!timeout);
6051         }
6052
6053         gro_normal_list(n);
6054
6055         if (unlikely(!list_empty(&n->poll_list))) {
6056                 /* If n->poll_list is not empty, we need to mask irqs */
6057                 local_irq_save(flags);
6058                 list_del_init(&n->poll_list);
6059                 local_irq_restore(flags);
6060         }
6061
6062         do {
6063                 val = READ_ONCE(n->state);
6064
6065                 WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6066
6067                 new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6068                               NAPIF_STATE_SCHED_THREADED |
6069                               NAPIF_STATE_PREFER_BUSY_POLL);
6070
6071                 /* If STATE_MISSED was set, leave STATE_SCHED set,
6072                  * because we will call napi->poll() one more time.
6073                  * This C code was suggested by Alexander Duyck to help gcc.
6074                  */
6075                 new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6076                                                     NAPIF_STATE_SCHED;
6077         } while (cmpxchg(&n->state, val, new) != val);
6078
6079         if (unlikely(val & NAPIF_STATE_MISSED)) {
6080                 __napi_schedule(n);
6081                 return false;
6082         }
6083
6084         if (timeout)
6085                 hrtimer_start(&n->timer, ns_to_ktime(timeout),
6086                               HRTIMER_MODE_REL_PINNED);
6087         return ret;
6088 }
6089 EXPORT_SYMBOL(napi_complete_done);
6090
6091 /* must be called under rcu_read_lock(), as we dont take a reference */
6092 static struct napi_struct *napi_by_id(unsigned int napi_id)
6093 {
6094         unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6095         struct napi_struct *napi;
6096
6097         hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6098                 if (napi->napi_id == napi_id)
6099                         return napi;
6100
6101         return NULL;
6102 }
6103
6104 #if defined(CONFIG_NET_RX_BUSY_POLL)
6105
6106 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6107 {
6108         if (!skip_schedule) {
6109                 gro_normal_list(napi);
6110                 __napi_schedule(napi);
6111                 return;
6112         }
6113
6114         if (napi->gro_bitmask) {
6115                 /* flush too old packets
6116                  * If HZ < 1000, flush all packets.
6117                  */
6118                 napi_gro_flush(napi, HZ >= 1000);
6119         }
6120
6121         gro_normal_list(napi);
6122         clear_bit(NAPI_STATE_SCHED, &napi->state);
6123 }
6124
6125 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6126                            u16 budget)
6127 {
6128         bool skip_schedule = false;
6129         unsigned long timeout;
6130         int rc;
6131
6132         /* Busy polling means there is a high chance device driver hard irq
6133          * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6134          * set in napi_schedule_prep().
6135          * Since we are about to call napi->poll() once more, we can safely
6136          * clear NAPI_STATE_MISSED.
6137          *
6138          * Note: x86 could use a single "lock and ..." instruction
6139          * to perform these two clear_bit()
6140          */
6141         clear_bit(NAPI_STATE_MISSED, &napi->state);
6142         clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6143
6144         local_bh_disable();
6145
6146         if (prefer_busy_poll) {
6147                 napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6148                 timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6149                 if (napi->defer_hard_irqs_count && timeout) {
6150                         hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6151                         skip_schedule = true;
6152                 }
6153         }
6154
6155         /* All we really want here is to re-enable device interrupts.
6156          * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6157          */
6158         rc = napi->poll(napi, budget);
6159         /* We can't gro_normal_list() here, because napi->poll() might have
6160          * rearmed the napi (napi_complete_done()) in which case it could
6161          * already be running on another CPU.
6162          */
6163         trace_napi_poll(napi, rc, budget);
6164         netpoll_poll_unlock(have_poll_lock);
6165         if (rc == budget)
6166                 __busy_poll_stop(napi, skip_schedule);
6167         local_bh_enable();
6168 }
6169
6170 void napi_busy_loop(unsigned int napi_id,
6171                     bool (*loop_end)(void *, unsigned long),
6172                     void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6173 {
6174         unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6175         int (*napi_poll)(struct napi_struct *napi, int budget);
6176         void *have_poll_lock = NULL;
6177         struct napi_struct *napi;
6178
6179 restart:
6180         napi_poll = NULL;
6181
6182         rcu_read_lock();
6183
6184         napi = napi_by_id(napi_id);
6185         if (!napi)
6186                 goto out;
6187
6188         preempt_disable();
6189         for (;;) {
6190                 int work = 0;
6191
6192                 local_bh_disable();
6193                 if (!napi_poll) {
6194                         unsigned long val = READ_ONCE(napi->state);
6195
6196                         /* If multiple threads are competing for this napi,
6197                          * we avoid dirtying napi->state as much as we can.
6198                          */
6199                         if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6200                                    NAPIF_STATE_IN_BUSY_POLL)) {
6201                                 if (prefer_busy_poll)
6202                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6203                                 goto count;
6204                         }
6205                         if (cmpxchg(&napi->state, val,
6206                                     val | NAPIF_STATE_IN_BUSY_POLL |
6207                                           NAPIF_STATE_SCHED) != val) {
6208                                 if (prefer_busy_poll)
6209                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6210                                 goto count;
6211                         }
6212                         have_poll_lock = netpoll_poll_lock(napi);
6213                         napi_poll = napi->poll;
6214                 }
6215                 work = napi_poll(napi, budget);
6216                 trace_napi_poll(napi, work, budget);
6217                 gro_normal_list(napi);
6218 count:
6219                 if (work > 0)
6220                         __NET_ADD_STATS(dev_net(napi->dev),
6221                                         LINUX_MIB_BUSYPOLLRXPACKETS, work);
6222                 local_bh_enable();
6223
6224                 if (!loop_end || loop_end(loop_end_arg, start_time))
6225                         break;
6226
6227                 if (unlikely(need_resched())) {
6228                         if (napi_poll)
6229                                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6230                         preempt_enable();
6231                         rcu_read_unlock();
6232                         cond_resched();
6233                         if (loop_end(loop_end_arg, start_time))
6234                                 return;
6235                         goto restart;
6236                 }
6237                 cpu_relax();
6238         }
6239         if (napi_poll)
6240                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6241         preempt_enable();
6242 out:
6243         rcu_read_unlock();
6244 }
6245 EXPORT_SYMBOL(napi_busy_loop);
6246
6247 #endif /* CONFIG_NET_RX_BUSY_POLL */
6248
6249 static void napi_hash_add(struct napi_struct *napi)
6250 {
6251         if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6252                 return;
6253
6254         spin_lock(&napi_hash_lock);
6255
6256         /* 0..NR_CPUS range is reserved for sender_cpu use */
6257         do {
6258                 if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6259                         napi_gen_id = MIN_NAPI_ID;
6260         } while (napi_by_id(napi_gen_id));
6261         napi->napi_id = napi_gen_id;
6262
6263         hlist_add_head_rcu(&napi->napi_hash_node,
6264                            &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6265
6266         spin_unlock(&napi_hash_lock);
6267 }
6268
6269 /* Warning : caller is responsible to make sure rcu grace period
6270  * is respected before freeing memory containing @napi
6271  */
6272 static void napi_hash_del(struct napi_struct *napi)
6273 {
6274         spin_lock(&napi_hash_lock);
6275
6276         hlist_del_init_rcu(&napi->napi_hash_node);
6277
6278         spin_unlock(&napi_hash_lock);
6279 }
6280
6281 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6282 {
6283         struct napi_struct *napi;
6284
6285         napi = container_of(timer, struct napi_struct, timer);
6286
6287         /* Note : we use a relaxed variant of napi_schedule_prep() not setting
6288          * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6289          */
6290         if (!napi_disable_pending(napi) &&
6291             !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6292                 clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6293                 __napi_schedule_irqoff(napi);
6294         }
6295
6296         return HRTIMER_NORESTART;
6297 }
6298
6299 static void init_gro_hash(struct napi_struct *napi)
6300 {
6301         int i;
6302
6303         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6304                 INIT_LIST_HEAD(&napi->gro_hash[i].list);
6305                 napi->gro_hash[i].count = 0;
6306         }
6307         napi->gro_bitmask = 0;
6308 }
6309
6310 int dev_set_threaded(struct net_device *dev, bool threaded)
6311 {
6312         struct napi_struct *napi;
6313         int err = 0;
6314
6315         if (dev->threaded == threaded)
6316                 return 0;
6317
6318         if (threaded) {
6319                 list_for_each_entry(napi, &dev->napi_list, dev_list) {
6320                         if (!napi->thread) {
6321                                 err = napi_kthread_create(napi);
6322                                 if (err) {
6323                                         threaded = false;
6324                                         break;
6325                                 }
6326                         }
6327                 }
6328         }
6329
6330         dev->threaded = threaded;
6331
6332         /* Make sure kthread is created before THREADED bit
6333          * is set.
6334          */
6335         smp_mb__before_atomic();
6336
6337         /* Setting/unsetting threaded mode on a napi might not immediately
6338          * take effect, if the current napi instance is actively being
6339          * polled. In this case, the switch between threaded mode and
6340          * softirq mode will happen in the next round of napi_schedule().
6341          * This should not cause hiccups/stalls to the live traffic.
6342          */
6343         list_for_each_entry(napi, &dev->napi_list, dev_list) {
6344                 if (threaded)
6345                         set_bit(NAPI_STATE_THREADED, &napi->state);
6346                 else
6347                         clear_bit(NAPI_STATE_THREADED, &napi->state);
6348         }
6349
6350         return err;
6351 }
6352 EXPORT_SYMBOL(dev_set_threaded);
6353
6354 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6355                            int (*poll)(struct napi_struct *, int), int weight)
6356 {
6357         if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6358                 return;
6359
6360         INIT_LIST_HEAD(&napi->poll_list);
6361         INIT_HLIST_NODE(&napi->napi_hash_node);
6362         hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6363         napi->timer.function = napi_watchdog;
6364         init_gro_hash(napi);
6365         napi->skb = NULL;
6366         INIT_LIST_HEAD(&napi->rx_list);
6367         napi->rx_count = 0;
6368         napi->poll = poll;
6369         if (weight > NAPI_POLL_WEIGHT)
6370                 netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6371                                 weight);
6372         napi->weight = weight;
6373         napi->dev = dev;
6374 #ifdef CONFIG_NETPOLL
6375         napi->poll_owner = -1;
6376 #endif
6377         set_bit(NAPI_STATE_SCHED, &napi->state);
6378         set_bit(NAPI_STATE_NPSVC, &napi->state);
6379         list_add_rcu(&napi->dev_list, &dev->napi_list);
6380         napi_hash_add(napi);
6381         /* Create kthread for this napi if dev->threaded is set.
6382          * Clear dev->threaded if kthread creation failed so that
6383          * threaded mode will not be enabled in napi_enable().
6384          */
6385         if (dev->threaded && napi_kthread_create(napi))
6386                 dev->threaded = 0;
6387 }
6388 EXPORT_SYMBOL(netif_napi_add_weight);
6389
6390 void napi_disable(struct napi_struct *n)
6391 {
6392         unsigned long val, new;
6393
6394         might_sleep();
6395         set_bit(NAPI_STATE_DISABLE, &n->state);
6396
6397         for ( ; ; ) {
6398                 val = READ_ONCE(n->state);
6399                 if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6400                         usleep_range(20, 200);
6401                         continue;
6402                 }
6403
6404                 new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6405                 new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6406
6407                 if (cmpxchg(&n->state, val, new) == val)
6408                         break;
6409         }
6410
6411         hrtimer_cancel(&n->timer);
6412
6413         clear_bit(NAPI_STATE_DISABLE, &n->state);
6414 }
6415 EXPORT_SYMBOL(napi_disable);
6416
6417 /**
6418  *      napi_enable - enable NAPI scheduling
6419  *      @n: NAPI context
6420  *
6421  * Resume NAPI from being scheduled on this context.
6422  * Must be paired with napi_disable.
6423  */
6424 void napi_enable(struct napi_struct *n)
6425 {
6426         unsigned long val, new;
6427
6428         do {
6429                 val = READ_ONCE(n->state);
6430                 BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6431
6432                 new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6433                 if (n->dev->threaded && n->thread)
6434                         new |= NAPIF_STATE_THREADED;
6435         } while (cmpxchg(&n->state, val, new) != val);
6436 }
6437 EXPORT_SYMBOL(napi_enable);
6438
6439 static void flush_gro_hash(struct napi_struct *napi)
6440 {
6441         int i;
6442
6443         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6444                 struct sk_buff *skb, *n;
6445
6446                 list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6447                         kfree_skb(skb);
6448                 napi->gro_hash[i].count = 0;
6449         }
6450 }
6451
6452 /* Must be called in process context */
6453 void __netif_napi_del(struct napi_struct *napi)
6454 {
6455         if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6456                 return;
6457
6458         napi_hash_del(napi);
6459         list_del_rcu(&napi->dev_list);
6460         napi_free_frags(napi);
6461
6462         flush_gro_hash(napi);
6463         napi->gro_bitmask = 0;
6464
6465         if (napi->thread) {
6466                 kthread_stop(napi->thread);
6467                 napi->thread = NULL;
6468         }
6469 }
6470 EXPORT_SYMBOL(__netif_napi_del);
6471
6472 static int __napi_poll(struct napi_struct *n, bool *repoll)
6473 {
6474         int work, weight;
6475
6476         weight = n->weight;
6477
6478         /* This NAPI_STATE_SCHED test is for avoiding a race
6479          * with netpoll's poll_napi().  Only the entity which
6480          * obtains the lock and sees NAPI_STATE_SCHED set will
6481          * actually make the ->poll() call.  Therefore we avoid
6482          * accidentally calling ->poll() when NAPI is not scheduled.
6483          */
6484         work = 0;
6485         if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6486                 work = n->poll(n, weight);
6487                 trace_napi_poll(n, work, weight);
6488         }
6489
6490         if (unlikely(work > weight))
6491                 netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6492                                 n->poll, work, weight);
6493
6494         if (likely(work < weight))
6495                 return work;
6496
6497         /* Drivers must not modify the NAPI state if they
6498          * consume the entire weight.  In such cases this code
6499          * still "owns" the NAPI instance and therefore can
6500          * move the instance around on the list at-will.
6501          */
6502         if (unlikely(napi_disable_pending(n))) {
6503                 napi_complete(n);
6504                 return work;
6505         }
6506
6507         /* The NAPI context has more processing work, but busy-polling
6508          * is preferred. Exit early.
6509          */
6510         if (napi_prefer_busy_poll(n)) {
6511                 if (napi_complete_done(n, work)) {
6512                         /* If timeout is not set, we need to make sure
6513                          * that the NAPI is re-scheduled.
6514                          */
6515                         napi_schedule(n);
6516                 }
6517                 return work;
6518         }
6519
6520         if (n->gro_bitmask) {
6521                 /* flush too old packets
6522                  * If HZ < 1000, flush all packets.
6523                  */
6524                 napi_gro_flush(n, HZ >= 1000);
6525         }
6526
6527         gro_normal_list(n);
6528
6529         /* Some drivers may have called napi_schedule
6530          * prior to exhausting their budget.
6531          */
6532         if (unlikely(!list_empty(&n->poll_list))) {
6533                 pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6534                              n->dev ? n->dev->name : "backlog");
6535                 return work;
6536         }
6537
6538         *repoll = true;
6539
6540         return work;
6541 }
6542
6543 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6544 {
6545         bool do_repoll = false;
6546         void *have;
6547         int work;
6548
6549         list_del_init(&n->poll_list);
6550
6551         have = netpoll_poll_lock(n);
6552
6553         work = __napi_poll(n, &do_repoll);
6554
6555         if (do_repoll)
6556                 list_add_tail(&n->poll_list, repoll);
6557
6558         netpoll_poll_unlock(have);
6559
6560         return work;
6561 }
6562
6563 static int napi_thread_wait(struct napi_struct *napi)
6564 {
6565         bool woken = false;
6566
6567         set_current_state(TASK_INTERRUPTIBLE);
6568
6569         while (!kthread_should_stop()) {
6570                 /* Testing SCHED_THREADED bit here to make sure the current
6571                  * kthread owns this napi and could poll on this napi.
6572                  * Testing SCHED bit is not enough because SCHED bit might be
6573                  * set by some other busy poll thread or by napi_disable().
6574                  */
6575                 if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6576                         WARN_ON(!list_empty(&napi->poll_list));
6577                         __set_current_state(TASK_RUNNING);
6578                         return 0;
6579                 }
6580
6581                 schedule();
6582                 /* woken being true indicates this thread owns this napi. */
6583                 woken = true;
6584                 set_current_state(TASK_INTERRUPTIBLE);
6585         }
6586         __set_current_state(TASK_RUNNING);
6587
6588         return -1;
6589 }
6590
6591 static int napi_threaded_poll(void *data)
6592 {
6593         struct napi_struct *napi = data;
6594         void *have;
6595
6596         while (!napi_thread_wait(napi)) {
6597                 for (;;) {
6598                         bool repoll = false;
6599
6600                         local_bh_disable();
6601
6602                         have = netpoll_poll_lock(napi);
6603                         __napi_poll(napi, &repoll);
6604                         netpoll_poll_unlock(have);
6605
6606                         local_bh_enable();
6607
6608                         if (!repoll)
6609                                 break;
6610
6611                         cond_resched();
6612                 }
6613         }
6614         return 0;
6615 }
6616
6617 static void skb_defer_free_flush(struct softnet_data *sd)
6618 {
6619         struct sk_buff *skb, *next;
6620         unsigned long flags;
6621
6622         /* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6623         if (!READ_ONCE(sd->defer_list))
6624                 return;
6625
6626         spin_lock_irqsave(&sd->defer_lock, flags);
6627         skb = sd->defer_list;
6628         sd->defer_list = NULL;
6629         sd->defer_count = 0;
6630         spin_unlock_irqrestore(&sd->defer_lock, flags);
6631
6632         while (skb != NULL) {
6633                 next = skb->next;
6634                 napi_consume_skb(skb, 1);
6635                 skb = next;
6636         }
6637 }
6638
6639 static __latent_entropy void net_rx_action(struct softirq_action *h)
6640 {
6641         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6642         unsigned long time_limit = jiffies +
6643                 usecs_to_jiffies(netdev_budget_usecs);
6644         int budget = netdev_budget;
6645         LIST_HEAD(list);
6646         LIST_HEAD(repoll);
6647
6648         local_irq_disable();
6649         list_splice_init(&sd->poll_list, &list);
6650         local_irq_enable();
6651
6652         for (;;) {
6653                 struct napi_struct *n;
6654
6655                 skb_defer_free_flush(sd);
6656
6657                 if (list_empty(&list)) {
6658                         if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
6659                                 goto end;
6660                         break;
6661                 }
6662
6663                 n = list_first_entry(&list, struct napi_struct, poll_list);
6664                 budget -= napi_poll(n, &repoll);
6665
6666                 /* If softirq window is exhausted then punt.
6667                  * Allow this to run for 2 jiffies since which will allow
6668                  * an average latency of 1.5/HZ.
6669                  */
6670                 if (unlikely(budget <= 0 ||
6671                              time_after_eq(jiffies, time_limit))) {
6672                         sd->time_squeeze++;
6673                         break;
6674                 }
6675         }
6676
6677         local_irq_disable();
6678
6679         list_splice_tail_init(&sd->poll_list, &list);
6680         list_splice_tail(&repoll, &list);
6681         list_splice(&list, &sd->poll_list);
6682         if (!list_empty(&sd->poll_list))
6683                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
6684
6685         net_rps_action_and_irq_enable(sd);
6686 end:;
6687 }
6688
6689 struct netdev_adjacent {
6690         struct net_device *dev;
6691         netdevice_tracker dev_tracker;
6692
6693         /* upper master flag, there can only be one master device per list */
6694         bool master;
6695
6696         /* lookup ignore flag */
6697         bool ignore;
6698
6699         /* counter for the number of times this device was added to us */
6700         u16 ref_nr;
6701
6702         /* private field for the users */
6703         void *private;
6704
6705         struct list_head list;
6706         struct rcu_head rcu;
6707 };
6708
6709 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6710                                                  struct list_head *adj_list)
6711 {
6712         struct netdev_adjacent *adj;
6713
6714         list_for_each_entry(adj, adj_list, list) {
6715                 if (adj->dev == adj_dev)
6716                         return adj;
6717         }
6718         return NULL;
6719 }
6720
6721 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6722                                     struct netdev_nested_priv *priv)
6723 {
6724         struct net_device *dev = (struct net_device *)priv->data;
6725
6726         return upper_dev == dev;
6727 }
6728
6729 /**
6730  * netdev_has_upper_dev - Check if device is linked to an upper device
6731  * @dev: device
6732  * @upper_dev: upper device to check
6733  *
6734  * Find out if a device is linked to specified upper device and return true
6735  * in case it is. Note that this checks only immediate upper device,
6736  * not through a complete stack of devices. The caller must hold the RTNL lock.
6737  */
6738 bool netdev_has_upper_dev(struct net_device *dev,
6739                           struct net_device *upper_dev)
6740 {
6741         struct netdev_nested_priv priv = {
6742                 .data = (void *)upper_dev,
6743         };
6744
6745         ASSERT_RTNL();
6746
6747         return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6748                                              &priv);
6749 }
6750 EXPORT_SYMBOL(netdev_has_upper_dev);
6751
6752 /**
6753  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6754  * @dev: device
6755  * @upper_dev: upper device to check
6756  *
6757  * Find out if a device is linked to specified upper device and return true
6758  * in case it is. Note that this checks the entire upper device chain.
6759  * The caller must hold rcu lock.
6760  */
6761
6762 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6763                                   struct net_device *upper_dev)
6764 {
6765         struct netdev_nested_priv priv = {
6766                 .data = (void *)upper_dev,
6767         };
6768
6769         return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6770                                                &priv);
6771 }
6772 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6773
6774 /**
6775  * netdev_has_any_upper_dev - Check if device is linked to some device
6776  * @dev: device
6777  *
6778  * Find out if a device is linked to an upper device and return true in case
6779  * it is. The caller must hold the RTNL lock.
6780  */
6781 bool netdev_has_any_upper_dev(struct net_device *dev)
6782 {
6783         ASSERT_RTNL();
6784
6785         return !list_empty(&dev->adj_list.upper);
6786 }
6787 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6788
6789 /**
6790  * netdev_master_upper_dev_get - Get master upper device
6791  * @dev: device
6792  *
6793  * Find a master upper device and return pointer to it or NULL in case
6794  * it's not there. The caller must hold the RTNL lock.
6795  */
6796 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6797 {
6798         struct netdev_adjacent *upper;
6799
6800         ASSERT_RTNL();
6801
6802         if (list_empty(&dev->adj_list.upper))
6803                 return NULL;
6804
6805         upper = list_first_entry(&dev->adj_list.upper,
6806                                  struct netdev_adjacent, list);
6807         if (likely(upper->master))
6808                 return upper->dev;
6809         return NULL;
6810 }
6811 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6812
6813 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6814 {
6815         struct netdev_adjacent *upper;
6816
6817         ASSERT_RTNL();
6818
6819         if (list_empty(&dev->adj_list.upper))
6820                 return NULL;
6821
6822         upper = list_first_entry(&dev->adj_list.upper,
6823                                  struct netdev_adjacent, list);
6824         if (likely(upper->master) && !upper->ignore)
6825                 return upper->dev;
6826         return NULL;
6827 }
6828
6829 /**
6830  * netdev_has_any_lower_dev - Check if device is linked to some device
6831  * @dev: device
6832  *
6833  * Find out if a device is linked to a lower device and return true in case
6834  * it is. The caller must hold the RTNL lock.
6835  */
6836 static bool netdev_has_any_lower_dev(struct net_device *dev)
6837 {
6838         ASSERT_RTNL();
6839
6840         return !list_empty(&dev->adj_list.lower);
6841 }
6842
6843 void *netdev_adjacent_get_private(struct list_head *adj_list)
6844 {
6845         struct netdev_adjacent *adj;
6846
6847         adj = list_entry(adj_list, struct netdev_adjacent, list);
6848
6849         return adj->private;
6850 }
6851 EXPORT_SYMBOL(netdev_adjacent_get_private);
6852
6853 /**
6854  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6855  * @dev: device
6856  * @iter: list_head ** of the current position
6857  *
6858  * Gets the next device from the dev's upper list, starting from iter
6859  * position. The caller must hold RCU read lock.
6860  */
6861 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6862                                                  struct list_head **iter)
6863 {
6864         struct netdev_adjacent *upper;
6865
6866         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6867
6868         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6869
6870         if (&upper->list == &dev->adj_list.upper)
6871                 return NULL;
6872
6873         *iter = &upper->list;
6874
6875         return upper->dev;
6876 }
6877 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6878
6879 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6880                                                   struct list_head **iter,
6881                                                   bool *ignore)
6882 {
6883         struct netdev_adjacent *upper;
6884
6885         upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6886
6887         if (&upper->list == &dev->adj_list.upper)
6888                 return NULL;
6889
6890         *iter = &upper->list;
6891         *ignore = upper->ignore;
6892
6893         return upper->dev;
6894 }
6895
6896 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6897                                                     struct list_head **iter)
6898 {
6899         struct netdev_adjacent *upper;
6900
6901         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6902
6903         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6904
6905         if (&upper->list == &dev->adj_list.upper)
6906                 return NULL;
6907
6908         *iter = &upper->list;
6909
6910         return upper->dev;
6911 }
6912
6913 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6914                                        int (*fn)(struct net_device *dev,
6915                                          struct netdev_nested_priv *priv),
6916                                        struct netdev_nested_priv *priv)
6917 {
6918         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6919         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6920         int ret, cur = 0;
6921         bool ignore;
6922
6923         now = dev;
6924         iter = &dev->adj_list.upper;
6925
6926         while (1) {
6927                 if (now != dev) {
6928                         ret = fn(now, priv);
6929                         if (ret)
6930                                 return ret;
6931                 }
6932
6933                 next = NULL;
6934                 while (1) {
6935                         udev = __netdev_next_upper_dev(now, &iter, &ignore);
6936                         if (!udev)
6937                                 break;
6938                         if (ignore)
6939                                 continue;
6940
6941                         next = udev;
6942                         niter = &udev->adj_list.upper;
6943                         dev_stack[cur] = now;
6944                         iter_stack[cur++] = iter;
6945                         break;
6946                 }
6947
6948                 if (!next) {
6949                         if (!cur)
6950                                 return 0;
6951                         next = dev_stack[--cur];
6952                         niter = iter_stack[cur];
6953                 }
6954
6955                 now = next;
6956                 iter = niter;
6957         }
6958
6959         return 0;
6960 }
6961
6962 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6963                                   int (*fn)(struct net_device *dev,
6964                                             struct netdev_nested_priv *priv),
6965                                   struct netdev_nested_priv *priv)
6966 {
6967         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6968         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6969         int ret, cur = 0;
6970
6971         now = dev;
6972         iter = &dev->adj_list.upper;
6973
6974         while (1) {
6975                 if (now != dev) {
6976                         ret = fn(now, priv);
6977                         if (ret)
6978                                 return ret;
6979                 }
6980
6981                 next = NULL;
6982                 while (1) {
6983                         udev = netdev_next_upper_dev_rcu(now, &iter);
6984                         if (!udev)
6985                                 break;
6986
6987                         next = udev;
6988                         niter = &udev->adj_list.upper;
6989                         dev_stack[cur] = now;
6990                         iter_stack[cur++] = iter;
6991                         break;
6992                 }
6993
6994                 if (!next) {
6995                         if (!cur)
6996                                 return 0;
6997                         next = dev_stack[--cur];
6998                         niter = iter_stack[cur];
6999                 }
7000
7001                 now = next;
7002                 iter = niter;
7003         }
7004
7005         return 0;
7006 }
7007 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7008
7009 static bool __netdev_has_upper_dev(struct net_device *dev,
7010                                    struct net_device *upper_dev)
7011 {
7012         struct netdev_nested_priv priv = {
7013                 .flags = 0,
7014                 .data = (void *)upper_dev,
7015         };
7016
7017         ASSERT_RTNL();
7018
7019         return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7020                                            &priv);
7021 }
7022
7023 /**
7024  * netdev_lower_get_next_private - Get the next ->private from the
7025  *                                 lower neighbour list
7026  * @dev: device
7027  * @iter: list_head ** of the current position
7028  *
7029  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7030  * list, starting from iter position. The caller must hold either hold the
7031  * RTNL lock or its own locking that guarantees that the neighbour lower
7032  * list will remain unchanged.
7033  */
7034 void *netdev_lower_get_next_private(struct net_device *dev,
7035                                     struct list_head **iter)
7036 {
7037         struct netdev_adjacent *lower;
7038
7039         lower = list_entry(*iter, struct netdev_adjacent, list);
7040
7041         if (&lower->list == &dev->adj_list.lower)
7042                 return NULL;
7043
7044         *iter = lower->list.next;
7045
7046         return lower->private;
7047 }
7048 EXPORT_SYMBOL(netdev_lower_get_next_private);
7049
7050 /**
7051  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7052  *                                     lower neighbour list, RCU
7053  *                                     variant
7054  * @dev: device
7055  * @iter: list_head ** of the current position
7056  *
7057  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7058  * list, starting from iter position. The caller must hold RCU read lock.
7059  */
7060 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7061                                         struct list_head **iter)
7062 {
7063         struct netdev_adjacent *lower;
7064
7065         WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7066
7067         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7068
7069         if (&lower->list == &dev->adj_list.lower)
7070                 return NULL;
7071
7072         *iter = &lower->list;
7073
7074         return lower->private;
7075 }
7076 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7077
7078 /**
7079  * netdev_lower_get_next - Get the next device from the lower neighbour
7080  *                         list
7081  * @dev: device
7082  * @iter: list_head ** of the current position
7083  *
7084  * Gets the next netdev_adjacent from the dev's lower neighbour
7085  * list, starting from iter position. The caller must hold RTNL lock or
7086  * its own locking that guarantees that the neighbour lower
7087  * list will remain unchanged.
7088  */
7089 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7090 {
7091         struct netdev_adjacent *lower;
7092
7093         lower = list_entry(*iter, struct netdev_adjacent, list);
7094
7095         if (&lower->list == &dev->adj_list.lower)
7096                 return NULL;
7097
7098         *iter = lower->list.next;
7099
7100         return lower->dev;
7101 }
7102 EXPORT_SYMBOL(netdev_lower_get_next);
7103
7104 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7105                                                 struct list_head **iter)
7106 {
7107         struct netdev_adjacent *lower;
7108
7109         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7110
7111         if (&lower->list == &dev->adj_list.lower)
7112                 return NULL;
7113
7114         *iter = &lower->list;
7115
7116         return lower->dev;
7117 }
7118
7119 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7120                                                   struct list_head **iter,
7121                                                   bool *ignore)
7122 {
7123         struct netdev_adjacent *lower;
7124
7125         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7126
7127         if (&lower->list == &dev->adj_list.lower)
7128                 return NULL;
7129
7130         *iter = &lower->list;
7131         *ignore = lower->ignore;
7132
7133         return lower->dev;
7134 }
7135
7136 int netdev_walk_all_lower_dev(struct net_device *dev,
7137                               int (*fn)(struct net_device *dev,
7138                                         struct netdev_nested_priv *priv),
7139                               struct netdev_nested_priv *priv)
7140 {
7141         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7142         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7143         int ret, cur = 0;
7144
7145         now = dev;
7146         iter = &dev->adj_list.lower;
7147
7148         while (1) {
7149                 if (now != dev) {
7150                         ret = fn(now, priv);
7151                         if (ret)
7152                                 return ret;
7153                 }
7154
7155                 next = NULL;
7156                 while (1) {
7157                         ldev = netdev_next_lower_dev(now, &iter);
7158                         if (!ldev)
7159                                 break;
7160
7161                         next = ldev;
7162                         niter = &ldev->adj_list.lower;
7163                         dev_stack[cur] = now;
7164                         iter_stack[cur++] = iter;
7165                         break;
7166                 }
7167
7168                 if (!next) {
7169                         if (!cur)
7170                                 return 0;
7171                         next = dev_stack[--cur];
7172                         niter = iter_stack[cur];
7173                 }
7174
7175                 now = next;
7176                 iter = niter;
7177         }
7178
7179         return 0;
7180 }
7181 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7182
7183 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7184                                        int (*fn)(struct net_device *dev,
7185                                          struct netdev_nested_priv *priv),
7186                                        struct netdev_nested_priv *priv)
7187 {
7188         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7189         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7190         int ret, cur = 0;
7191         bool ignore;
7192
7193         now = dev;
7194         iter = &dev->adj_list.lower;
7195
7196         while (1) {
7197                 if (now != dev) {
7198                         ret = fn(now, priv);
7199                         if (ret)
7200                                 return ret;
7201                 }
7202
7203                 next = NULL;
7204                 while (1) {
7205                         ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7206                         if (!ldev)
7207                                 break;
7208                         if (ignore)
7209                                 continue;
7210
7211                         next = ldev;
7212                         niter = &ldev->adj_list.lower;
7213                         dev_stack[cur] = now;
7214                         iter_stack[cur++] = iter;
7215                         break;
7216                 }
7217
7218                 if (!next) {
7219                         if (!cur)
7220                                 return 0;
7221                         next = dev_stack[--cur];
7222                         niter = iter_stack[cur];
7223                 }
7224
7225                 now = next;
7226                 iter = niter;
7227         }
7228
7229         return 0;
7230 }
7231
7232 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7233                                              struct list_head **iter)
7234 {
7235         struct netdev_adjacent *lower;
7236
7237         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7238         if (&lower->list == &dev->adj_list.lower)
7239                 return NULL;
7240
7241         *iter = &lower->list;
7242
7243         return lower->dev;
7244 }
7245 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7246
7247 static u8 __netdev_upper_depth(struct net_device *dev)
7248 {
7249         struct net_device *udev;
7250         struct list_head *iter;
7251         u8 max_depth = 0;
7252         bool ignore;
7253
7254         for (iter = &dev->adj_list.upper,
7255              udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7256              udev;
7257              udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7258                 if (ignore)
7259                         continue;
7260                 if (max_depth < udev->upper_level)
7261                         max_depth = udev->upper_level;
7262         }
7263
7264         return max_depth;
7265 }
7266
7267 static u8 __netdev_lower_depth(struct net_device *dev)
7268 {
7269         struct net_device *ldev;
7270         struct list_head *iter;
7271         u8 max_depth = 0;
7272         bool ignore;
7273
7274         for (iter = &dev->adj_list.lower,
7275              ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7276              ldev;
7277              ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7278                 if (ignore)
7279                         continue;
7280                 if (max_depth < ldev->lower_level)
7281                         max_depth = ldev->lower_level;
7282         }
7283
7284         return max_depth;
7285 }
7286
7287 static int __netdev_update_upper_level(struct net_device *dev,
7288                                        struct netdev_nested_priv *__unused)
7289 {
7290         dev->upper_level = __netdev_upper_depth(dev) + 1;
7291         return 0;
7292 }
7293
7294 #ifdef CONFIG_LOCKDEP
7295 static LIST_HEAD(net_unlink_list);
7296
7297 static void net_unlink_todo(struct net_device *dev)
7298 {
7299         if (list_empty(&dev->unlink_list))
7300                 list_add_tail(&dev->unlink_list, &net_unlink_list);
7301 }
7302 #endif
7303
7304 static int __netdev_update_lower_level(struct net_device *dev,
7305                                        struct netdev_nested_priv *priv)
7306 {
7307         dev->lower_level = __netdev_lower_depth(dev) + 1;
7308
7309 #ifdef CONFIG_LOCKDEP
7310         if (!priv)
7311                 return 0;
7312
7313         if (priv->flags & NESTED_SYNC_IMM)
7314                 dev->nested_level = dev->lower_level - 1;
7315         if (priv->flags & NESTED_SYNC_TODO)
7316                 net_unlink_todo(dev);
7317 #endif
7318         return 0;
7319 }
7320
7321 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7322                                   int (*fn)(struct net_device *dev,
7323                                             struct netdev_nested_priv *priv),
7324                                   struct netdev_nested_priv *priv)
7325 {
7326         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7327         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7328         int ret, cur = 0;
7329
7330         now = dev;
7331         iter = &dev->adj_list.lower;
7332
7333         while (1) {
7334                 if (now != dev) {
7335                         ret = fn(now, priv);
7336                         if (ret)
7337                                 return ret;
7338                 }
7339
7340                 next = NULL;
7341                 while (1) {
7342                         ldev = netdev_next_lower_dev_rcu(now, &iter);
7343                         if (!ldev)
7344                                 break;
7345
7346                         next = ldev;
7347                         niter = &ldev->adj_list.lower;
7348                         dev_stack[cur] = now;
7349                         iter_stack[cur++] = iter;
7350                         break;
7351                 }
7352
7353                 if (!next) {
7354                         if (!cur)
7355                                 return 0;
7356                         next = dev_stack[--cur];
7357                         niter = iter_stack[cur];
7358                 }
7359
7360                 now = next;
7361                 iter = niter;
7362         }
7363
7364         return 0;
7365 }
7366 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7367
7368 /**
7369  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7370  *                                     lower neighbour list, RCU
7371  *                                     variant
7372  * @dev: device
7373  *
7374  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7375  * list. The caller must hold RCU read lock.
7376  */
7377 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7378 {
7379         struct netdev_adjacent *lower;
7380
7381         lower = list_first_or_null_rcu(&dev->adj_list.lower,
7382                         struct netdev_adjacent, list);
7383         if (lower)
7384                 return lower->private;
7385         return NULL;
7386 }
7387 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7388
7389 /**
7390  * netdev_master_upper_dev_get_rcu - Get master upper device
7391  * @dev: device
7392  *
7393  * Find a master upper device and return pointer to it or NULL in case
7394  * it's not there. The caller must hold the RCU read lock.
7395  */
7396 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7397 {
7398         struct netdev_adjacent *upper;
7399
7400         upper = list_first_or_null_rcu(&dev->adj_list.upper,
7401                                        struct netdev_adjacent, list);
7402         if (upper && likely(upper->master))
7403                 return upper->dev;
7404         return NULL;
7405 }
7406 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7407
7408 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7409                               struct net_device *adj_dev,
7410                               struct list_head *dev_list)
7411 {
7412         char linkname[IFNAMSIZ+7];
7413
7414         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7415                 "upper_%s" : "lower_%s", adj_dev->name);
7416         return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7417                                  linkname);
7418 }
7419 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7420                                char *name,
7421                                struct list_head *dev_list)
7422 {
7423         char linkname[IFNAMSIZ+7];
7424
7425         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7426                 "upper_%s" : "lower_%s", name);
7427         sysfs_remove_link(&(dev->dev.kobj), linkname);
7428 }
7429
7430 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7431                                                  struct net_device *adj_dev,
7432                                                  struct list_head *dev_list)
7433 {
7434         return (dev_list == &dev->adj_list.upper ||
7435                 dev_list == &dev->adj_list.lower) &&
7436                 net_eq(dev_net(dev), dev_net(adj_dev));
7437 }
7438
7439 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7440                                         struct net_device *adj_dev,
7441                                         struct list_head *dev_list,
7442                                         void *private, bool master)
7443 {
7444         struct netdev_adjacent *adj;
7445         int ret;
7446
7447         adj = __netdev_find_adj(adj_dev, dev_list);
7448
7449         if (adj) {
7450                 adj->ref_nr += 1;
7451                 pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7452                          dev->name, adj_dev->name, adj->ref_nr);
7453
7454                 return 0;
7455         }
7456
7457         adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7458         if (!adj)
7459                 return -ENOMEM;
7460
7461         adj->dev = adj_dev;
7462         adj->master = master;
7463         adj->ref_nr = 1;
7464         adj->private = private;
7465         adj->ignore = false;
7466         dev_hold_track(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7467
7468         pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7469                  dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7470
7471         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7472                 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7473                 if (ret)
7474                         goto free_adj;
7475         }
7476
7477         /* Ensure that master link is always the first item in list. */
7478         if (master) {
7479                 ret = sysfs_create_link(&(dev->dev.kobj),
7480                                         &(adj_dev->dev.kobj), "master");
7481                 if (ret)
7482                         goto remove_symlinks;
7483
7484                 list_add_rcu(&adj->list, dev_list);
7485         } else {
7486                 list_add_tail_rcu(&adj->list, dev_list);
7487         }
7488
7489         return 0;
7490
7491 remove_symlinks:
7492         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7493                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7494 free_adj:
7495         dev_put_track(adj_dev, &adj->dev_tracker);
7496         kfree(adj);
7497
7498         return ret;
7499 }
7500
7501 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7502                                          struct net_device *adj_dev,
7503                                          u16 ref_nr,
7504                                          struct list_head *dev_list)
7505 {
7506         struct netdev_adjacent *adj;
7507
7508         pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7509                  dev->name, adj_dev->name, ref_nr);
7510
7511         adj = __netdev_find_adj(adj_dev, dev_list);
7512
7513         if (!adj) {
7514                 pr_err("Adjacency does not exist for device %s from %s\n",
7515                        dev->name, adj_dev->name);
7516                 WARN_ON(1);
7517                 return;
7518         }
7519
7520         if (adj->ref_nr > ref_nr) {
7521                 pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7522                          dev->name, adj_dev->name, ref_nr,
7523                          adj->ref_nr - ref_nr);
7524                 adj->ref_nr -= ref_nr;
7525                 return;
7526         }
7527
7528         if (adj->master)
7529                 sysfs_remove_link(&(dev->dev.kobj), "master");
7530
7531         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7532                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7533
7534         list_del_rcu(&adj->list);
7535         pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7536                  adj_dev->name, dev->name, adj_dev->name);
7537         dev_put_track(adj_dev, &adj->dev_tracker);
7538         kfree_rcu(adj, rcu);
7539 }
7540
7541 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7542                                             struct net_device *upper_dev,
7543                                             struct list_head *up_list,
7544                                             struct list_head *down_list,
7545                                             void *private, bool master)
7546 {
7547         int ret;
7548
7549         ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7550                                            private, master);
7551         if (ret)
7552                 return ret;
7553
7554         ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7555                                            private, false);
7556         if (ret) {
7557                 __netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7558                 return ret;
7559         }
7560
7561         return 0;
7562 }
7563
7564 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7565                                                struct net_device *upper_dev,
7566                                                u16 ref_nr,
7567                                                struct list_head *up_list,
7568                                                struct list_head *down_list)
7569 {
7570         __netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7571         __netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7572 }
7573
7574 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7575                                                 struct net_device *upper_dev,
7576                                                 void *private, bool master)
7577 {
7578         return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7579                                                 &dev->adj_list.upper,
7580                                                 &upper_dev->adj_list.lower,
7581                                                 private, master);
7582 }
7583
7584 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7585                                                    struct net_device *upper_dev)
7586 {
7587         __netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7588                                            &dev->adj_list.upper,
7589                                            &upper_dev->adj_list.lower);
7590 }
7591
7592 static int __netdev_upper_dev_link(struct net_device *dev,
7593                                    struct net_device *upper_dev, bool master,
7594                                    void *upper_priv, void *upper_info,
7595                                    struct netdev_nested_priv *priv,
7596                                    struct netlink_ext_ack *extack)
7597 {
7598         struct netdev_notifier_changeupper_info changeupper_info = {
7599                 .info = {
7600                         .dev = dev,
7601                         .extack = extack,
7602                 },
7603                 .upper_dev = upper_dev,
7604                 .master = master,
7605                 .linking = true,
7606                 .upper_info = upper_info,
7607         };
7608         struct net_device *master_dev;
7609         int ret = 0;
7610
7611         ASSERT_RTNL();
7612
7613         if (dev == upper_dev)
7614                 return -EBUSY;
7615
7616         /* To prevent loops, check if dev is not upper device to upper_dev. */
7617         if (__netdev_has_upper_dev(upper_dev, dev))
7618                 return -EBUSY;
7619
7620         if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7621                 return -EMLINK;
7622
7623         if (!master) {
7624                 if (__netdev_has_upper_dev(dev, upper_dev))
7625                         return -EEXIST;
7626         } else {
7627                 master_dev = __netdev_master_upper_dev_get(dev);
7628                 if (master_dev)
7629                         return master_dev == upper_dev ? -EEXIST : -EBUSY;
7630         }
7631
7632         ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7633                                             &changeupper_info.info);
7634         ret = notifier_to_errno(ret);
7635         if (ret)
7636                 return ret;
7637
7638         ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7639                                                    master);
7640         if (ret)
7641                 return ret;
7642
7643         ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7644                                             &changeupper_info.info);
7645         ret = notifier_to_errno(ret);
7646         if (ret)
7647                 goto rollback;
7648
7649         __netdev_update_upper_level(dev, NULL);
7650         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7651
7652         __netdev_update_lower_level(upper_dev, priv);
7653         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7654                                     priv);
7655
7656         return 0;
7657
7658 rollback:
7659         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7660
7661         return ret;
7662 }
7663
7664 /**
7665  * netdev_upper_dev_link - Add a link to the upper device
7666  * @dev: device
7667  * @upper_dev: new upper device
7668  * @extack: netlink extended ack
7669  *
7670  * Adds a link to device which is upper to this one. The caller must hold
7671  * the RTNL lock. On a failure a negative errno code is returned.
7672  * On success the reference counts are adjusted and the function
7673  * returns zero.
7674  */
7675 int netdev_upper_dev_link(struct net_device *dev,
7676                           struct net_device *upper_dev,
7677                           struct netlink_ext_ack *extack)
7678 {
7679         struct netdev_nested_priv priv = {
7680                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7681                 .data = NULL,
7682         };
7683
7684         return __netdev_upper_dev_link(dev, upper_dev, false,
7685                                        NULL, NULL, &priv, extack);
7686 }
7687 EXPORT_SYMBOL(netdev_upper_dev_link);
7688
7689 /**
7690  * netdev_master_upper_dev_link - Add a master link to the upper device
7691  * @dev: device
7692  * @upper_dev: new upper device
7693  * @upper_priv: upper device private
7694  * @upper_info: upper info to be passed down via notifier
7695  * @extack: netlink extended ack
7696  *
7697  * Adds a link to device which is upper to this one. In this case, only
7698  * one master upper device can be linked, although other non-master devices
7699  * might be linked as well. The caller must hold the RTNL lock.
7700  * On a failure a negative errno code is returned. On success the reference
7701  * counts are adjusted and the function returns zero.
7702  */
7703 int netdev_master_upper_dev_link(struct net_device *dev,
7704                                  struct net_device *upper_dev,
7705                                  void *upper_priv, void *upper_info,
7706                                  struct netlink_ext_ack *extack)
7707 {
7708         struct netdev_nested_priv priv = {
7709                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7710                 .data = NULL,
7711         };
7712
7713         return __netdev_upper_dev_link(dev, upper_dev, true,
7714                                        upper_priv, upper_info, &priv, extack);
7715 }
7716 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7717
7718 static void __netdev_upper_dev_unlink(struct net_device *dev,
7719                                       struct net_device *upper_dev,
7720                                       struct netdev_nested_priv *priv)
7721 {
7722         struct netdev_notifier_changeupper_info changeupper_info = {
7723                 .info = {
7724                         .dev = dev,
7725                 },
7726                 .upper_dev = upper_dev,
7727                 .linking = false,
7728         };
7729
7730         ASSERT_RTNL();
7731
7732         changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7733
7734         call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7735                                       &changeupper_info.info);
7736
7737         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7738
7739         call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7740                                       &changeupper_info.info);
7741
7742         __netdev_update_upper_level(dev, NULL);
7743         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7744
7745         __netdev_update_lower_level(upper_dev, priv);
7746         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7747                                     priv);
7748 }
7749
7750 /**
7751  * netdev_upper_dev_unlink - Removes a link to upper device
7752  * @dev: device
7753  * @upper_dev: new upper device
7754  *
7755  * Removes a link to device which is upper to this one. The caller must hold
7756  * the RTNL lock.
7757  */
7758 void netdev_upper_dev_unlink(struct net_device *dev,
7759                              struct net_device *upper_dev)
7760 {
7761         struct netdev_nested_priv priv = {
7762                 .flags = NESTED_SYNC_TODO,
7763                 .data = NULL,
7764         };
7765
7766         __netdev_upper_dev_unlink(dev, upper_dev, &priv);
7767 }
7768 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7769
7770 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7771                                       struct net_device *lower_dev,
7772                                       bool val)
7773 {
7774         struct netdev_adjacent *adj;
7775
7776         adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7777         if (adj)
7778                 adj->ignore = val;
7779
7780         adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7781         if (adj)
7782                 adj->ignore = val;
7783 }
7784
7785 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7786                                         struct net_device *lower_dev)
7787 {
7788         __netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7789 }
7790
7791 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7792                                        struct net_device *lower_dev)
7793 {
7794         __netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7795 }
7796
7797 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7798                                    struct net_device *new_dev,
7799                                    struct net_device *dev,
7800                                    struct netlink_ext_ack *extack)
7801 {
7802         struct netdev_nested_priv priv = {
7803                 .flags = 0,
7804                 .data = NULL,
7805         };
7806         int err;
7807
7808         if (!new_dev)
7809                 return 0;
7810
7811         if (old_dev && new_dev != old_dev)
7812                 netdev_adjacent_dev_disable(dev, old_dev);
7813         err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7814                                       extack);
7815         if (err) {
7816                 if (old_dev && new_dev != old_dev)
7817                         netdev_adjacent_dev_enable(dev, old_dev);
7818                 return err;
7819         }
7820
7821         return 0;
7822 }
7823 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7824
7825 void netdev_adjacent_change_commit(struct net_device *old_dev,
7826                                    struct net_device *new_dev,
7827                                    struct net_device *dev)
7828 {
7829         struct netdev_nested_priv priv = {
7830                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7831                 .data = NULL,
7832         };
7833
7834         if (!new_dev || !old_dev)
7835                 return;
7836
7837         if (new_dev == old_dev)
7838                 return;
7839
7840         netdev_adjacent_dev_enable(dev, old_dev);
7841         __netdev_upper_dev_unlink(old_dev, dev, &priv);
7842 }
7843 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7844
7845 void netdev_adjacent_change_abort(struct net_device *old_dev,
7846                                   struct net_device *new_dev,
7847                                   struct net_device *dev)
7848 {
7849         struct netdev_nested_priv priv = {
7850                 .flags = 0,
7851                 .data = NULL,
7852         };
7853
7854         if (!new_dev)
7855                 return;
7856
7857         if (old_dev && new_dev != old_dev)
7858                 netdev_adjacent_dev_enable(dev, old_dev);
7859
7860         __netdev_upper_dev_unlink(new_dev, dev, &priv);
7861 }
7862 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7863
7864 /**
7865  * netdev_bonding_info_change - Dispatch event about slave change
7866  * @dev: device
7867  * @bonding_info: info to dispatch
7868  *
7869  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7870  * The caller must hold the RTNL lock.
7871  */
7872 void netdev_bonding_info_change(struct net_device *dev,
7873                                 struct netdev_bonding_info *bonding_info)
7874 {
7875         struct netdev_notifier_bonding_info info = {
7876                 .info.dev = dev,
7877         };
7878
7879         memcpy(&info.bonding_info, bonding_info,
7880                sizeof(struct netdev_bonding_info));
7881         call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7882                                       &info.info);
7883 }
7884 EXPORT_SYMBOL(netdev_bonding_info_change);
7885
7886 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7887                                            struct netlink_ext_ack *extack)
7888 {
7889         struct netdev_notifier_offload_xstats_info info = {
7890                 .info.dev = dev,
7891                 .info.extack = extack,
7892                 .type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7893         };
7894         int err;
7895         int rc;
7896
7897         dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7898                                          GFP_KERNEL);
7899         if (!dev->offload_xstats_l3)
7900                 return -ENOMEM;
7901
7902         rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7903                                                   NETDEV_OFFLOAD_XSTATS_DISABLE,
7904                                                   &info.info);
7905         err = notifier_to_errno(rc);
7906         if (err)
7907                 goto free_stats;
7908
7909         return 0;
7910
7911 free_stats:
7912         kfree(dev->offload_xstats_l3);
7913         dev->offload_xstats_l3 = NULL;
7914         return err;
7915 }
7916
7917 int netdev_offload_xstats_enable(struct net_device *dev,
7918                                  enum netdev_offload_xstats_type type,
7919                                  struct netlink_ext_ack *extack)
7920 {
7921         ASSERT_RTNL();
7922
7923         if (netdev_offload_xstats_enabled(dev, type))
7924                 return -EALREADY;
7925
7926         switch (type) {
7927         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7928                 return netdev_offload_xstats_enable_l3(dev, extack);
7929         }
7930
7931         WARN_ON(1);
7932         return -EINVAL;
7933 }
7934 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7935
7936 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7937 {
7938         struct netdev_notifier_offload_xstats_info info = {
7939                 .info.dev = dev,
7940                 .type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7941         };
7942
7943         call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
7944                                       &info.info);
7945         kfree(dev->offload_xstats_l3);
7946         dev->offload_xstats_l3 = NULL;
7947 }
7948
7949 int netdev_offload_xstats_disable(struct net_device *dev,
7950                                   enum netdev_offload_xstats_type type)
7951 {
7952         ASSERT_RTNL();
7953
7954         if (!netdev_offload_xstats_enabled(dev, type))
7955                 return -EALREADY;
7956
7957         switch (type) {
7958         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7959                 netdev_offload_xstats_disable_l3(dev);
7960                 return 0;
7961         }
7962
7963         WARN_ON(1);
7964         return -EINVAL;
7965 }
7966 EXPORT_SYMBOL(netdev_offload_xstats_disable);
7967
7968 static void netdev_offload_xstats_disable_all(struct net_device *dev)
7969 {
7970         netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
7971 }
7972
7973 static struct rtnl_hw_stats64 *
7974 netdev_offload_xstats_get_ptr(const struct net_device *dev,
7975                               enum netdev_offload_xstats_type type)
7976 {
7977         switch (type) {
7978         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7979                 return dev->offload_xstats_l3;
7980         }
7981
7982         WARN_ON(1);
7983         return NULL;
7984 }
7985
7986 bool netdev_offload_xstats_enabled(const struct net_device *dev,
7987                                    enum netdev_offload_xstats_type type)
7988 {
7989         ASSERT_RTNL();
7990
7991         return netdev_offload_xstats_get_ptr(dev, type);
7992 }
7993 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
7994
7995 struct netdev_notifier_offload_xstats_ru {
7996         bool used;
7997 };
7998
7999 struct netdev_notifier_offload_xstats_rd {
8000         struct rtnl_hw_stats64 stats;
8001         bool used;
8002 };
8003
8004 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8005                                   const struct rtnl_hw_stats64 *src)
8006 {
8007         dest->rx_packets          += src->rx_packets;
8008         dest->tx_packets          += src->tx_packets;
8009         dest->rx_bytes            += src->rx_bytes;
8010         dest->tx_bytes            += src->tx_bytes;
8011         dest->rx_errors           += src->rx_errors;
8012         dest->tx_errors           += src->tx_errors;
8013         dest->rx_dropped          += src->rx_dropped;
8014         dest->tx_dropped          += src->tx_dropped;
8015         dest->multicast           += src->multicast;
8016 }
8017
8018 static int netdev_offload_xstats_get_used(struct net_device *dev,
8019                                           enum netdev_offload_xstats_type type,
8020                                           bool *p_used,
8021                                           struct netlink_ext_ack *extack)
8022 {
8023         struct netdev_notifier_offload_xstats_ru report_used = {};
8024         struct netdev_notifier_offload_xstats_info info = {
8025                 .info.dev = dev,
8026                 .info.extack = extack,
8027                 .type = type,
8028                 .report_used = &report_used,
8029         };
8030         int rc;
8031
8032         WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8033         rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8034                                            &info.info);
8035         *p_used = report_used.used;
8036         return notifier_to_errno(rc);
8037 }
8038
8039 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8040                                            enum netdev_offload_xstats_type type,
8041                                            struct rtnl_hw_stats64 *p_stats,
8042                                            bool *p_used,
8043                                            struct netlink_ext_ack *extack)
8044 {
8045         struct netdev_notifier_offload_xstats_rd report_delta = {};
8046         struct netdev_notifier_offload_xstats_info info = {
8047                 .info.dev = dev,
8048                 .info.extack = extack,
8049                 .type = type,
8050                 .report_delta = &report_delta,
8051         };
8052         struct rtnl_hw_stats64 *stats;
8053         int rc;
8054
8055         stats = netdev_offload_xstats_get_ptr(dev, type);
8056         if (WARN_ON(!stats))
8057                 return -EINVAL;
8058
8059         rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8060                                            &info.info);
8061
8062         /* Cache whatever we got, even if there was an error, otherwise the
8063          * successful stats retrievals would get lost.
8064          */
8065         netdev_hw_stats64_add(stats, &report_delta.stats);
8066
8067         if (p_stats)
8068                 *p_stats = *stats;
8069         *p_used = report_delta.used;
8070
8071         return notifier_to_errno(rc);
8072 }
8073
8074 int netdev_offload_xstats_get(struct net_device *dev,
8075                               enum netdev_offload_xstats_type type,
8076                               struct rtnl_hw_stats64 *p_stats, bool *p_used,
8077                               struct netlink_ext_ack *extack)
8078 {
8079         ASSERT_RTNL();
8080
8081         if (p_stats)
8082                 return netdev_offload_xstats_get_stats(dev, type, p_stats,
8083                                                        p_used, extack);
8084         else
8085                 return netdev_offload_xstats_get_used(dev, type, p_used,
8086                                                       extack);
8087 }
8088 EXPORT_SYMBOL(netdev_offload_xstats_get);
8089
8090 void
8091 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8092                                    const struct rtnl_hw_stats64 *stats)
8093 {
8094         report_delta->used = true;
8095         netdev_hw_stats64_add(&report_delta->stats, stats);
8096 }
8097 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8098
8099 void
8100 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8101 {
8102         report_used->used = true;
8103 }
8104 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8105
8106 void netdev_offload_xstats_push_delta(struct net_device *dev,
8107                                       enum netdev_offload_xstats_type type,
8108                                       const struct rtnl_hw_stats64 *p_stats)
8109 {
8110         struct rtnl_hw_stats64 *stats;
8111
8112         ASSERT_RTNL();
8113
8114         stats = netdev_offload_xstats_get_ptr(dev, type);
8115         if (WARN_ON(!stats))
8116                 return;
8117
8118         netdev_hw_stats64_add(stats, p_stats);
8119 }
8120 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8121
8122 /**
8123  * netdev_get_xmit_slave - Get the xmit slave of master device
8124  * @dev: device
8125  * @skb: The packet
8126  * @all_slaves: assume all the slaves are active
8127  *
8128  * The reference counters are not incremented so the caller must be
8129  * careful with locks. The caller must hold RCU lock.
8130  * %NULL is returned if no slave is found.
8131  */
8132
8133 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8134                                          struct sk_buff *skb,
8135                                          bool all_slaves)
8136 {
8137         const struct net_device_ops *ops = dev->netdev_ops;
8138
8139         if (!ops->ndo_get_xmit_slave)
8140                 return NULL;
8141         return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8142 }
8143 EXPORT_SYMBOL(netdev_get_xmit_slave);
8144
8145 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8146                                                   struct sock *sk)
8147 {
8148         const struct net_device_ops *ops = dev->netdev_ops;
8149
8150         if (!ops->ndo_sk_get_lower_dev)
8151                 return NULL;
8152         return ops->ndo_sk_get_lower_dev(dev, sk);
8153 }
8154
8155 /**
8156  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8157  * @dev: device
8158  * @sk: the socket
8159  *
8160  * %NULL is returned if no lower device is found.
8161  */
8162
8163 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8164                                             struct sock *sk)
8165 {
8166         struct net_device *lower;
8167
8168         lower = netdev_sk_get_lower_dev(dev, sk);
8169         while (lower) {
8170                 dev = lower;
8171                 lower = netdev_sk_get_lower_dev(dev, sk);
8172         }
8173
8174         return dev;
8175 }
8176 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8177
8178 static void netdev_adjacent_add_links(struct net_device *dev)
8179 {
8180         struct netdev_adjacent *iter;
8181
8182         struct net *net = dev_net(dev);
8183
8184         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8185                 if (!net_eq(net, dev_net(iter->dev)))
8186                         continue;
8187                 netdev_adjacent_sysfs_add(iter->dev, dev,
8188                                           &iter->dev->adj_list.lower);
8189                 netdev_adjacent_sysfs_add(dev, iter->dev,
8190                                           &dev->adj_list.upper);
8191         }
8192
8193         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8194                 if (!net_eq(net, dev_net(iter->dev)))
8195                         continue;
8196                 netdev_adjacent_sysfs_add(iter->dev, dev,
8197                                           &iter->dev->adj_list.upper);
8198                 netdev_adjacent_sysfs_add(dev, iter->dev,
8199                                           &dev->adj_list.lower);
8200         }
8201 }
8202
8203 static void netdev_adjacent_del_links(struct net_device *dev)
8204 {
8205         struct netdev_adjacent *iter;
8206
8207         struct net *net = dev_net(dev);
8208
8209         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8210                 if (!net_eq(net, dev_net(iter->dev)))
8211                         continue;
8212                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8213                                           &iter->dev->adj_list.lower);
8214                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8215                                           &dev->adj_list.upper);
8216         }
8217
8218         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8219                 if (!net_eq(net, dev_net(iter->dev)))
8220                         continue;
8221                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8222                                           &iter->dev->adj_list.upper);
8223                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8224                                           &dev->adj_list.lower);
8225         }
8226 }
8227
8228 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8229 {
8230         struct netdev_adjacent *iter;
8231
8232         struct net *net = dev_net(dev);
8233
8234         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8235                 if (!net_eq(net, dev_net(iter->dev)))
8236                         continue;
8237                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8238                                           &iter->dev->adj_list.lower);
8239                 netdev_adjacent_sysfs_add(iter->dev, dev,
8240                                           &iter->dev->adj_list.lower);
8241         }
8242
8243         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8244                 if (!net_eq(net, dev_net(iter->dev)))
8245                         continue;
8246                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8247                                           &iter->dev->adj_list.upper);
8248                 netdev_adjacent_sysfs_add(iter->dev, dev,
8249                                           &iter->dev->adj_list.upper);
8250         }
8251 }
8252
8253 void *netdev_lower_dev_get_private(struct net_device *dev,
8254                                    struct net_device *lower_dev)
8255 {
8256         struct netdev_adjacent *lower;
8257
8258         if (!lower_dev)
8259                 return NULL;
8260         lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8261         if (!lower)
8262                 return NULL;
8263
8264         return lower->private;
8265 }
8266 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8267
8268
8269 /**
8270  * netdev_lower_state_changed - Dispatch event about lower device state change
8271  * @lower_dev: device
8272  * @lower_state_info: state to dispatch
8273  *
8274  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8275  * The caller must hold the RTNL lock.
8276  */
8277 void netdev_lower_state_changed(struct net_device *lower_dev,
8278                                 void *lower_state_info)
8279 {
8280         struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8281                 .info.dev = lower_dev,
8282         };
8283
8284         ASSERT_RTNL();
8285         changelowerstate_info.lower_state_info = lower_state_info;
8286         call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8287                                       &changelowerstate_info.info);
8288 }
8289 EXPORT_SYMBOL(netdev_lower_state_changed);
8290
8291 static void dev_change_rx_flags(struct net_device *dev, int flags)
8292 {
8293         const struct net_device_ops *ops = dev->netdev_ops;
8294
8295         if (ops->ndo_change_rx_flags)
8296                 ops->ndo_change_rx_flags(dev, flags);
8297 }
8298
8299 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8300 {
8301         unsigned int old_flags = dev->flags;
8302         kuid_t uid;
8303         kgid_t gid;
8304
8305         ASSERT_RTNL();
8306
8307         dev->flags |= IFF_PROMISC;
8308         dev->promiscuity += inc;
8309         if (dev->promiscuity == 0) {
8310                 /*
8311                  * Avoid overflow.
8312                  * If inc causes overflow, untouch promisc and return error.
8313                  */
8314                 if (inc < 0)
8315                         dev->flags &= ~IFF_PROMISC;
8316                 else {
8317                         dev->promiscuity -= inc;
8318                         netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8319                         return -EOVERFLOW;
8320                 }
8321         }
8322         if (dev->flags != old_flags) {
8323                 pr_info("device %s %s promiscuous mode\n",
8324                         dev->name,
8325                         dev->flags & IFF_PROMISC ? "entered" : "left");
8326                 if (audit_enabled) {
8327                         current_uid_gid(&uid, &gid);
8328                         audit_log(audit_context(), GFP_ATOMIC,
8329                                   AUDIT_ANOM_PROMISCUOUS,
8330                                   "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8331                                   dev->name, (dev->flags & IFF_PROMISC),
8332                                   (old_flags & IFF_PROMISC),
8333                                   from_kuid(&init_user_ns, audit_get_loginuid(current)),
8334                                   from_kuid(&init_user_ns, uid),
8335                                   from_kgid(&init_user_ns, gid),
8336                                   audit_get_sessionid(current));
8337                 }
8338
8339                 dev_change_rx_flags(dev, IFF_PROMISC);
8340         }
8341         if (notify)
8342                 __dev_notify_flags(dev, old_flags, IFF_PROMISC);
8343         return 0;
8344 }
8345
8346 /**
8347  *      dev_set_promiscuity     - update promiscuity count on a device
8348  *      @dev: device
8349  *      @inc: modifier
8350  *
8351  *      Add or remove promiscuity from a device. While the count in the device
8352  *      remains above zero the interface remains promiscuous. Once it hits zero
8353  *      the device reverts back to normal filtering operation. A negative inc
8354  *      value is used to drop promiscuity on the device.
8355  *      Return 0 if successful or a negative errno code on error.
8356  */
8357 int dev_set_promiscuity(struct net_device *dev, int inc)
8358 {
8359         unsigned int old_flags = dev->flags;
8360         int err;
8361
8362         err = __dev_set_promiscuity(dev, inc, true);
8363         if (err < 0)
8364                 return err;
8365         if (dev->flags != old_flags)
8366                 dev_set_rx_mode(dev);
8367         return err;
8368 }
8369 EXPORT_SYMBOL(dev_set_promiscuity);
8370
8371 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8372 {
8373         unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8374
8375         ASSERT_RTNL();
8376
8377         dev->flags |= IFF_ALLMULTI;
8378         dev->allmulti += inc;
8379         if (dev->allmulti == 0) {
8380                 /*
8381                  * Avoid overflow.
8382                  * If inc causes overflow, untouch allmulti and return error.
8383                  */
8384                 if (inc < 0)
8385                         dev->flags &= ~IFF_ALLMULTI;
8386                 else {
8387                         dev->allmulti -= inc;
8388                         netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8389                         return -EOVERFLOW;
8390                 }
8391         }
8392         if (dev->flags ^ old_flags) {
8393                 dev_change_rx_flags(dev, IFF_ALLMULTI);
8394                 dev_set_rx_mode(dev);
8395                 if (notify)
8396                         __dev_notify_flags(dev, old_flags,
8397                                            dev->gflags ^ old_gflags);
8398         }
8399         return 0;
8400 }
8401
8402 /**
8403  *      dev_set_allmulti        - update allmulti count on a device
8404  *      @dev: device
8405  *      @inc: modifier
8406  *
8407  *      Add or remove reception of all multicast frames to a device. While the
8408  *      count in the device remains above zero the interface remains listening
8409  *      to all interfaces. Once it hits zero the device reverts back to normal
8410  *      filtering operation. A negative @inc value is used to drop the counter
8411  *      when releasing a resource needing all multicasts.
8412  *      Return 0 if successful or a negative errno code on error.
8413  */
8414
8415 int dev_set_allmulti(struct net_device *dev, int inc)
8416 {
8417         return __dev_set_allmulti(dev, inc, true);
8418 }
8419 EXPORT_SYMBOL(dev_set_allmulti);
8420
8421 /*
8422  *      Upload unicast and multicast address lists to device and
8423  *      configure RX filtering. When the device doesn't support unicast
8424  *      filtering it is put in promiscuous mode while unicast addresses
8425  *      are present.
8426  */
8427 void __dev_set_rx_mode(struct net_device *dev)
8428 {
8429         const struct net_device_ops *ops = dev->netdev_ops;
8430
8431         /* dev_open will call this function so the list will stay sane. */
8432         if (!(dev->flags&IFF_UP))
8433                 return;
8434
8435         if (!netif_device_present(dev))
8436                 return;
8437
8438         if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8439                 /* Unicast addresses changes may only happen under the rtnl,
8440                  * therefore calling __dev_set_promiscuity here is safe.
8441                  */
8442                 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8443                         __dev_set_promiscuity(dev, 1, false);
8444                         dev->uc_promisc = true;
8445                 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8446                         __dev_set_promiscuity(dev, -1, false);
8447                         dev->uc_promisc = false;
8448                 }
8449         }
8450
8451         if (ops->ndo_set_rx_mode)
8452                 ops->ndo_set_rx_mode(dev);
8453 }
8454
8455 void dev_set_rx_mode(struct net_device *dev)
8456 {
8457         netif_addr_lock_bh(dev);
8458         __dev_set_rx_mode(dev);
8459         netif_addr_unlock_bh(dev);
8460 }
8461
8462 /**
8463  *      dev_get_flags - get flags reported to userspace
8464  *      @dev: device
8465  *
8466  *      Get the combination of flag bits exported through APIs to userspace.
8467  */
8468 unsigned int dev_get_flags(const struct net_device *dev)
8469 {
8470         unsigned int flags;
8471
8472         flags = (dev->flags & ~(IFF_PROMISC |
8473                                 IFF_ALLMULTI |
8474                                 IFF_RUNNING |
8475                                 IFF_LOWER_UP |
8476                                 IFF_DORMANT)) |
8477                 (dev->gflags & (IFF_PROMISC |
8478                                 IFF_ALLMULTI));
8479
8480         if (netif_running(dev)) {
8481                 if (netif_oper_up(dev))
8482                         flags |= IFF_RUNNING;
8483                 if (netif_carrier_ok(dev))
8484                         flags |= IFF_LOWER_UP;
8485                 if (netif_dormant(dev))
8486                         flags |= IFF_DORMANT;
8487         }
8488
8489         return flags;
8490 }
8491 EXPORT_SYMBOL(dev_get_flags);
8492
8493 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8494                        struct netlink_ext_ack *extack)
8495 {
8496         unsigned int old_flags = dev->flags;
8497         int ret;
8498
8499         ASSERT_RTNL();
8500
8501         /*
8502          *      Set the flags on our device.
8503          */
8504
8505         dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8506                                IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8507                                IFF_AUTOMEDIA)) |
8508                      (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8509                                     IFF_ALLMULTI));
8510
8511         /*
8512          *      Load in the correct multicast list now the flags have changed.
8513          */
8514
8515         if ((old_flags ^ flags) & IFF_MULTICAST)
8516                 dev_change_rx_flags(dev, IFF_MULTICAST);
8517
8518         dev_set_rx_mode(dev);
8519
8520         /*
8521          *      Have we downed the interface. We handle IFF_UP ourselves
8522          *      according to user attempts to set it, rather than blindly
8523          *      setting it.
8524          */
8525
8526         ret = 0;
8527         if ((old_flags ^ flags) & IFF_UP) {
8528                 if (old_flags & IFF_UP)
8529                         __dev_close(dev);
8530                 else
8531                         ret = __dev_open(dev, extack);
8532         }
8533
8534         if ((flags ^ dev->gflags) & IFF_PROMISC) {
8535                 int inc = (flags & IFF_PROMISC) ? 1 : -1;
8536                 unsigned int old_flags = dev->flags;
8537
8538                 dev->gflags ^= IFF_PROMISC;
8539
8540                 if (__dev_set_promiscuity(dev, inc, false) >= 0)
8541                         if (dev->flags != old_flags)
8542                                 dev_set_rx_mode(dev);
8543         }
8544
8545         /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8546          * is important. Some (broken) drivers set IFF_PROMISC, when
8547          * IFF_ALLMULTI is requested not asking us and not reporting.
8548          */
8549         if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8550                 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8551
8552                 dev->gflags ^= IFF_ALLMULTI;
8553                 __dev_set_allmulti(dev, inc, false);
8554         }
8555
8556         return ret;
8557 }
8558
8559 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8560                         unsigned int gchanges)
8561 {
8562         unsigned int changes = dev->flags ^ old_flags;
8563
8564         if (gchanges)
8565                 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
8566
8567         if (changes & IFF_UP) {
8568                 if (dev->flags & IFF_UP)
8569                         call_netdevice_notifiers(NETDEV_UP, dev);
8570                 else
8571                         call_netdevice_notifiers(NETDEV_DOWN, dev);
8572         }
8573
8574         if (dev->flags & IFF_UP &&
8575             (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8576                 struct netdev_notifier_change_info change_info = {
8577                         .info = {
8578                                 .dev = dev,
8579                         },
8580                         .flags_changed = changes,
8581                 };
8582
8583                 call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8584         }
8585 }
8586
8587 /**
8588  *      dev_change_flags - change device settings
8589  *      @dev: device
8590  *      @flags: device state flags
8591  *      @extack: netlink extended ack
8592  *
8593  *      Change settings on device based state flags. The flags are
8594  *      in the userspace exported format.
8595  */
8596 int dev_change_flags(struct net_device *dev, unsigned int flags,
8597                      struct netlink_ext_ack *extack)
8598 {
8599         int ret;
8600         unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8601
8602         ret = __dev_change_flags(dev, flags, extack);
8603         if (ret < 0)
8604                 return ret;
8605
8606         changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8607         __dev_notify_flags(dev, old_flags, changes);
8608         return ret;
8609 }
8610 EXPORT_SYMBOL(dev_change_flags);
8611
8612 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8613 {
8614         const struct net_device_ops *ops = dev->netdev_ops;
8615
8616         if (ops->ndo_change_mtu)
8617                 return ops->ndo_change_mtu(dev, new_mtu);
8618
8619         /* Pairs with all the lockless reads of dev->mtu in the stack */
8620         WRITE_ONCE(dev->mtu, new_mtu);
8621         return 0;
8622 }
8623 EXPORT_SYMBOL(__dev_set_mtu);
8624
8625 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8626                      struct netlink_ext_ack *extack)
8627 {
8628         /* MTU must be positive, and in range */
8629         if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8630                 NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8631                 return -EINVAL;
8632         }
8633
8634         if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8635                 NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8636                 return -EINVAL;
8637         }
8638         return 0;
8639 }
8640
8641 /**
8642  *      dev_set_mtu_ext - Change maximum transfer unit
8643  *      @dev: device
8644  *      @new_mtu: new transfer unit
8645  *      @extack: netlink extended ack
8646  *
8647  *      Change the maximum transfer size of the network device.
8648  */
8649 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8650                     struct netlink_ext_ack *extack)
8651 {
8652         int err, orig_mtu;
8653
8654         if (new_mtu == dev->mtu)
8655                 return 0;
8656
8657         err = dev_validate_mtu(dev, new_mtu, extack);
8658         if (err)
8659                 return err;
8660
8661         if (!netif_device_present(dev))
8662                 return -ENODEV;
8663
8664         err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8665         err = notifier_to_errno(err);
8666         if (err)
8667                 return err;
8668
8669         orig_mtu = dev->mtu;
8670         err = __dev_set_mtu(dev, new_mtu);
8671
8672         if (!err) {
8673                 err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8674                                                    orig_mtu);
8675                 err = notifier_to_errno(err);
8676                 if (err) {
8677                         /* setting mtu back and notifying everyone again,
8678                          * so that they have a chance to revert changes.
8679                          */
8680                         __dev_set_mtu(dev, orig_mtu);
8681                         call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8682                                                      new_mtu);
8683                 }
8684         }
8685         return err;
8686 }
8687
8688 int dev_set_mtu(struct net_device *dev, int new_mtu)
8689 {
8690         struct netlink_ext_ack extack;
8691         int err;
8692
8693         memset(&extack, 0, sizeof(extack));
8694         err = dev_set_mtu_ext(dev, new_mtu, &extack);
8695         if (err && extack._msg)
8696                 net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8697         return err;
8698 }
8699 EXPORT_SYMBOL(dev_set_mtu);
8700
8701 /**
8702  *      dev_change_tx_queue_len - Change TX queue length of a netdevice
8703  *      @dev: device
8704  *      @new_len: new tx queue length
8705  */
8706 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8707 {
8708         unsigned int orig_len = dev->tx_queue_len;
8709         int res;
8710
8711         if (new_len != (unsigned int)new_len)
8712                 return -ERANGE;
8713
8714         if (new_len != orig_len) {
8715                 dev->tx_queue_len = new_len;
8716                 res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8717                 res = notifier_to_errno(res);
8718                 if (res)
8719                         goto err_rollback;
8720                 res = dev_qdisc_change_tx_queue_len(dev);
8721                 if (res)
8722                         goto err_rollback;
8723         }
8724
8725         return 0;
8726
8727 err_rollback:
8728         netdev_err(dev, "refused to change device tx_queue_len\n");
8729         dev->tx_queue_len = orig_len;
8730         return res;
8731 }
8732
8733 /**
8734  *      dev_set_group - Change group this device belongs to
8735  *      @dev: device
8736  *      @new_group: group this device should belong to
8737  */
8738 void dev_set_group(struct net_device *dev, int new_group)
8739 {
8740         dev->group = new_group;
8741 }
8742
8743 /**
8744  *      dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8745  *      @dev: device
8746  *      @addr: new address
8747  *      @extack: netlink extended ack
8748  */
8749 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8750                               struct netlink_ext_ack *extack)
8751 {
8752         struct netdev_notifier_pre_changeaddr_info info = {
8753                 .info.dev = dev,
8754                 .info.extack = extack,
8755                 .dev_addr = addr,
8756         };
8757         int rc;
8758
8759         rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8760         return notifier_to_errno(rc);
8761 }
8762 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8763
8764 /**
8765  *      dev_set_mac_address - Change Media Access Control Address
8766  *      @dev: device
8767  *      @sa: new address
8768  *      @extack: netlink extended ack
8769  *
8770  *      Change the hardware (MAC) address of the device
8771  */
8772 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8773                         struct netlink_ext_ack *extack)
8774 {
8775         const struct net_device_ops *ops = dev->netdev_ops;
8776         int err;
8777
8778         if (!ops->ndo_set_mac_address)
8779                 return -EOPNOTSUPP;
8780         if (sa->sa_family != dev->type)
8781                 return -EINVAL;
8782         if (!netif_device_present(dev))
8783                 return -ENODEV;
8784         err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8785         if (err)
8786                 return err;
8787         err = ops->ndo_set_mac_address(dev, sa);
8788         if (err)
8789                 return err;
8790         dev->addr_assign_type = NET_ADDR_SET;
8791         call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8792         add_device_randomness(dev->dev_addr, dev->addr_len);
8793         return 0;
8794 }
8795 EXPORT_SYMBOL(dev_set_mac_address);
8796
8797 static DECLARE_RWSEM(dev_addr_sem);
8798
8799 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8800                              struct netlink_ext_ack *extack)
8801 {
8802         int ret;
8803
8804         down_write(&dev_addr_sem);
8805         ret = dev_set_mac_address(dev, sa, extack);
8806         up_write(&dev_addr_sem);
8807         return ret;
8808 }
8809 EXPORT_SYMBOL(dev_set_mac_address_user);
8810
8811 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8812 {
8813         size_t size = sizeof(sa->sa_data);
8814         struct net_device *dev;
8815         int ret = 0;
8816
8817         down_read(&dev_addr_sem);
8818         rcu_read_lock();
8819
8820         dev = dev_get_by_name_rcu(net, dev_name);
8821         if (!dev) {
8822                 ret = -ENODEV;
8823                 goto unlock;
8824         }
8825         if (!dev->addr_len)
8826                 memset(sa->sa_data, 0, size);
8827         else
8828                 memcpy(sa->sa_data, dev->dev_addr,
8829                        min_t(size_t, size, dev->addr_len));
8830         sa->sa_family = dev->type;
8831
8832 unlock:
8833         rcu_read_unlock();
8834         up_read(&dev_addr_sem);
8835         return ret;
8836 }
8837 EXPORT_SYMBOL(dev_get_mac_address);
8838
8839 /**
8840  *      dev_change_carrier - Change device carrier
8841  *      @dev: device
8842  *      @new_carrier: new value
8843  *
8844  *      Change device carrier
8845  */
8846 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8847 {
8848         const struct net_device_ops *ops = dev->netdev_ops;
8849
8850         if (!ops->ndo_change_carrier)
8851                 return -EOPNOTSUPP;
8852         if (!netif_device_present(dev))
8853                 return -ENODEV;
8854         return ops->ndo_change_carrier(dev, new_carrier);
8855 }
8856
8857 /**
8858  *      dev_get_phys_port_id - Get device physical port ID
8859  *      @dev: device
8860  *      @ppid: port ID
8861  *
8862  *      Get device physical port ID
8863  */
8864 int dev_get_phys_port_id(struct net_device *dev,
8865                          struct netdev_phys_item_id *ppid)
8866 {
8867         const struct net_device_ops *ops = dev->netdev_ops;
8868
8869         if (!ops->ndo_get_phys_port_id)
8870                 return -EOPNOTSUPP;
8871         return ops->ndo_get_phys_port_id(dev, ppid);
8872 }
8873
8874 /**
8875  *      dev_get_phys_port_name - Get device physical port name
8876  *      @dev: device
8877  *      @name: port name
8878  *      @len: limit of bytes to copy to name
8879  *
8880  *      Get device physical port name
8881  */
8882 int dev_get_phys_port_name(struct net_device *dev,
8883                            char *name, size_t len)
8884 {
8885         const struct net_device_ops *ops = dev->netdev_ops;
8886         int err;
8887
8888         if (ops->ndo_get_phys_port_name) {
8889                 err = ops->ndo_get_phys_port_name(dev, name, len);
8890                 if (err != -EOPNOTSUPP)
8891                         return err;
8892         }
8893         return devlink_compat_phys_port_name_get(dev, name, len);
8894 }
8895
8896 /**
8897  *      dev_get_port_parent_id - Get the device's port parent identifier
8898  *      @dev: network device
8899  *      @ppid: pointer to a storage for the port's parent identifier
8900  *      @recurse: allow/disallow recursion to lower devices
8901  *
8902  *      Get the devices's port parent identifier
8903  */
8904 int dev_get_port_parent_id(struct net_device *dev,
8905                            struct netdev_phys_item_id *ppid,
8906                            bool recurse)
8907 {
8908         const struct net_device_ops *ops = dev->netdev_ops;
8909         struct netdev_phys_item_id first = { };
8910         struct net_device *lower_dev;
8911         struct list_head *iter;
8912         int err;
8913
8914         if (ops->ndo_get_port_parent_id) {
8915                 err = ops->ndo_get_port_parent_id(dev, ppid);
8916                 if (err != -EOPNOTSUPP)
8917                         return err;
8918         }
8919
8920         err = devlink_compat_switch_id_get(dev, ppid);
8921         if (!recurse || err != -EOPNOTSUPP)
8922                 return err;
8923
8924         netdev_for_each_lower_dev(dev, lower_dev, iter) {
8925                 err = dev_get_port_parent_id(lower_dev, ppid, true);
8926                 if (err)
8927                         break;
8928                 if (!first.id_len)
8929                         first = *ppid;
8930                 else if (memcmp(&first, ppid, sizeof(*ppid)))
8931                         return -EOPNOTSUPP;
8932         }
8933
8934         return err;
8935 }
8936 EXPORT_SYMBOL(dev_get_port_parent_id);
8937
8938 /**
8939  *      netdev_port_same_parent_id - Indicate if two network devices have
8940  *      the same port parent identifier
8941  *      @a: first network device
8942  *      @b: second network device
8943  */
8944 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
8945 {
8946         struct netdev_phys_item_id a_id = { };
8947         struct netdev_phys_item_id b_id = { };
8948
8949         if (dev_get_port_parent_id(a, &a_id, true) ||
8950             dev_get_port_parent_id(b, &b_id, true))
8951                 return false;
8952
8953         return netdev_phys_item_id_same(&a_id, &b_id);
8954 }
8955 EXPORT_SYMBOL(netdev_port_same_parent_id);
8956
8957 /**
8958  *      dev_change_proto_down - set carrier according to proto_down.
8959  *
8960  *      @dev: device
8961  *      @proto_down: new value
8962  */
8963 int dev_change_proto_down(struct net_device *dev, bool proto_down)
8964 {
8965         if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
8966                 return -EOPNOTSUPP;
8967         if (!netif_device_present(dev))
8968                 return -ENODEV;
8969         if (proto_down)
8970                 netif_carrier_off(dev);
8971         else
8972                 netif_carrier_on(dev);
8973         dev->proto_down = proto_down;
8974         return 0;
8975 }
8976
8977 /**
8978  *      dev_change_proto_down_reason - proto down reason
8979  *
8980  *      @dev: device
8981  *      @mask: proto down mask
8982  *      @value: proto down value
8983  */
8984 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
8985                                   u32 value)
8986 {
8987         int b;
8988
8989         if (!mask) {
8990                 dev->proto_down_reason = value;
8991         } else {
8992                 for_each_set_bit(b, &mask, 32) {
8993                         if (value & (1 << b))
8994                                 dev->proto_down_reason |= BIT(b);
8995                         else
8996                                 dev->proto_down_reason &= ~BIT(b);
8997                 }
8998         }
8999 }
9000
9001 struct bpf_xdp_link {
9002         struct bpf_link link;
9003         struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9004         int flags;
9005 };
9006
9007 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9008 {
9009         if (flags & XDP_FLAGS_HW_MODE)
9010                 return XDP_MODE_HW;
9011         if (flags & XDP_FLAGS_DRV_MODE)
9012                 return XDP_MODE_DRV;
9013         if (flags & XDP_FLAGS_SKB_MODE)
9014                 return XDP_MODE_SKB;
9015         return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9016 }
9017
9018 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9019 {
9020         switch (mode) {
9021         case XDP_MODE_SKB:
9022                 return generic_xdp_install;
9023         case XDP_MODE_DRV:
9024         case XDP_MODE_HW:
9025                 return dev->netdev_ops->ndo_bpf;
9026         default:
9027                 return NULL;
9028         }
9029 }
9030
9031 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9032                                          enum bpf_xdp_mode mode)
9033 {
9034         return dev->xdp_state[mode].link;
9035 }
9036
9037 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9038                                      enum bpf_xdp_mode mode)
9039 {
9040         struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9041
9042         if (link)
9043                 return link->link.prog;
9044         return dev->xdp_state[mode].prog;
9045 }
9046
9047 u8 dev_xdp_prog_count(struct net_device *dev)
9048 {
9049         u8 count = 0;
9050         int i;
9051
9052         for (i = 0; i < __MAX_XDP_MODE; i++)
9053                 if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9054                         count++;
9055         return count;
9056 }
9057 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9058
9059 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9060 {
9061         struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9062
9063         return prog ? prog->aux->id : 0;
9064 }
9065
9066 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9067                              struct bpf_xdp_link *link)
9068 {
9069         dev->xdp_state[mode].link = link;
9070         dev->xdp_state[mode].prog = NULL;
9071 }
9072
9073 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9074                              struct bpf_prog *prog)
9075 {
9076         dev->xdp_state[mode].link = NULL;
9077         dev->xdp_state[mode].prog = prog;
9078 }
9079
9080 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9081                            bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9082                            u32 flags, struct bpf_prog *prog)
9083 {
9084         struct netdev_bpf xdp;
9085         int err;
9086
9087         memset(&xdp, 0, sizeof(xdp));
9088         xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9089         xdp.extack = extack;
9090         xdp.flags = flags;
9091         xdp.prog = prog;
9092
9093         /* Drivers assume refcnt is already incremented (i.e, prog pointer is
9094          * "moved" into driver), so they don't increment it on their own, but
9095          * they do decrement refcnt when program is detached or replaced.
9096          * Given net_device also owns link/prog, we need to bump refcnt here
9097          * to prevent drivers from underflowing it.
9098          */
9099         if (prog)
9100                 bpf_prog_inc(prog);
9101         err = bpf_op(dev, &xdp);
9102         if (err) {
9103                 if (prog)
9104                         bpf_prog_put(prog);
9105                 return err;
9106         }
9107
9108         if (mode != XDP_MODE_HW)
9109                 bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9110
9111         return 0;
9112 }
9113
9114 static void dev_xdp_uninstall(struct net_device *dev)
9115 {
9116         struct bpf_xdp_link *link;
9117         struct bpf_prog *prog;
9118         enum bpf_xdp_mode mode;
9119         bpf_op_t bpf_op;
9120
9121         ASSERT_RTNL();
9122
9123         for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9124                 prog = dev_xdp_prog(dev, mode);
9125                 if (!prog)
9126                         continue;
9127
9128                 bpf_op = dev_xdp_bpf_op(dev, mode);
9129                 if (!bpf_op)
9130                         continue;
9131
9132                 WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9133
9134                 /* auto-detach link from net device */
9135                 link = dev_xdp_link(dev, mode);
9136                 if (link)
9137                         link->dev = NULL;
9138                 else
9139                         bpf_prog_put(prog);
9140
9141                 dev_xdp_set_link(dev, mode, NULL);
9142         }
9143 }
9144
9145 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9146                           struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9147                           struct bpf_prog *old_prog, u32 flags)
9148 {
9149         unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9150         struct bpf_prog *cur_prog;
9151         struct net_device *upper;
9152         struct list_head *iter;
9153         enum bpf_xdp_mode mode;
9154         bpf_op_t bpf_op;
9155         int err;
9156
9157         ASSERT_RTNL();
9158
9159         /* either link or prog attachment, never both */
9160         if (link && (new_prog || old_prog))
9161                 return -EINVAL;
9162         /* link supports only XDP mode flags */
9163         if (link && (flags & ~XDP_FLAGS_MODES)) {
9164                 NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9165                 return -EINVAL;
9166         }
9167         /* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9168         if (num_modes > 1) {
9169                 NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9170                 return -EINVAL;
9171         }
9172         /* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9173         if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9174                 NL_SET_ERR_MSG(extack,
9175                                "More than one program loaded, unset mode is ambiguous");
9176                 return -EINVAL;
9177         }
9178         /* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9179         if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9180                 NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9181                 return -EINVAL;
9182         }
9183
9184         mode = dev_xdp_mode(dev, flags);
9185         /* can't replace attached link */
9186         if (dev_xdp_link(dev, mode)) {
9187                 NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9188                 return -EBUSY;
9189         }
9190
9191         /* don't allow if an upper device already has a program */
9192         netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9193                 if (dev_xdp_prog_count(upper) > 0) {
9194                         NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9195                         return -EEXIST;
9196                 }
9197         }
9198
9199         cur_prog = dev_xdp_prog(dev, mode);
9200         /* can't replace attached prog with link */
9201         if (link && cur_prog) {
9202                 NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9203                 return -EBUSY;
9204         }
9205         if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9206                 NL_SET_ERR_MSG(extack, "Active program does not match expected");
9207                 return -EEXIST;
9208         }
9209
9210         /* put effective new program into new_prog */
9211         if (link)
9212                 new_prog = link->link.prog;
9213
9214         if (new_prog) {
9215                 bool offload = mode == XDP_MODE_HW;
9216                 enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9217                                                ? XDP_MODE_DRV : XDP_MODE_SKB;
9218
9219                 if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9220                         NL_SET_ERR_MSG(extack, "XDP program already attached");
9221                         return -EBUSY;
9222                 }
9223                 if (!offload && dev_xdp_prog(dev, other_mode)) {
9224                         NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9225                         return -EEXIST;
9226                 }
9227                 if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
9228                         NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
9229                         return -EINVAL;
9230                 }
9231                 if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9232                         NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9233                         return -EINVAL;
9234                 }
9235                 if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9236                         NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9237                         return -EINVAL;
9238                 }
9239         }
9240
9241         /* don't call drivers if the effective program didn't change */
9242         if (new_prog != cur_prog) {
9243                 bpf_op = dev_xdp_bpf_op(dev, mode);
9244                 if (!bpf_op) {
9245                         NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9246                         return -EOPNOTSUPP;
9247                 }
9248
9249                 err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9250                 if (err)
9251                         return err;
9252         }
9253
9254         if (link)
9255                 dev_xdp_set_link(dev, mode, link);
9256         else
9257                 dev_xdp_set_prog(dev, mode, new_prog);
9258         if (cur_prog)
9259                 bpf_prog_put(cur_prog);
9260
9261         return 0;
9262 }
9263
9264 static int dev_xdp_attach_link(struct net_device *dev,
9265                                struct netlink_ext_ack *extack,
9266                                struct bpf_xdp_link *link)
9267 {
9268         return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9269 }
9270
9271 static int dev_xdp_detach_link(struct net_device *dev,
9272                                struct netlink_ext_ack *extack,
9273                                struct bpf_xdp_link *link)
9274 {
9275         enum bpf_xdp_mode mode;
9276         bpf_op_t bpf_op;
9277
9278         ASSERT_RTNL();
9279
9280         mode = dev_xdp_mode(dev, link->flags);
9281         if (dev_xdp_link(dev, mode) != link)
9282                 return -EINVAL;
9283
9284         bpf_op = dev_xdp_bpf_op(dev, mode);
9285         WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9286         dev_xdp_set_link(dev, mode, NULL);
9287         return 0;
9288 }
9289
9290 static void bpf_xdp_link_release(struct bpf_link *link)
9291 {
9292         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9293
9294         rtnl_lock();
9295
9296         /* if racing with net_device's tear down, xdp_link->dev might be
9297          * already NULL, in which case link was already auto-detached
9298          */
9299         if (xdp_link->dev) {
9300                 WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9301                 xdp_link->dev = NULL;
9302         }
9303
9304         rtnl_unlock();
9305 }
9306
9307 static int bpf_xdp_link_detach(struct bpf_link *link)
9308 {
9309         bpf_xdp_link_release(link);
9310         return 0;
9311 }
9312
9313 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9314 {
9315         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9316
9317         kfree(xdp_link);
9318 }
9319
9320 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9321                                      struct seq_file *seq)
9322 {
9323         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9324         u32 ifindex = 0;
9325
9326         rtnl_lock();
9327         if (xdp_link->dev)
9328                 ifindex = xdp_link->dev->ifindex;
9329         rtnl_unlock();
9330
9331         seq_printf(seq, "ifindex:\t%u\n", ifindex);
9332 }
9333
9334 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9335                                        struct bpf_link_info *info)
9336 {
9337         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9338         u32 ifindex = 0;
9339
9340         rtnl_lock();
9341         if (xdp_link->dev)
9342                 ifindex = xdp_link->dev->ifindex;
9343         rtnl_unlock();
9344
9345         info->xdp.ifindex = ifindex;
9346         return 0;
9347 }
9348
9349 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9350                                struct bpf_prog *old_prog)
9351 {
9352         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9353         enum bpf_xdp_mode mode;
9354         bpf_op_t bpf_op;
9355         int err = 0;
9356
9357         rtnl_lock();
9358
9359         /* link might have been auto-released already, so fail */
9360         if (!xdp_link->dev) {
9361                 err = -ENOLINK;
9362                 goto out_unlock;
9363         }
9364
9365         if (old_prog && link->prog != old_prog) {
9366                 err = -EPERM;
9367                 goto out_unlock;
9368         }
9369         old_prog = link->prog;
9370         if (old_prog->type != new_prog->type ||
9371             old_prog->expected_attach_type != new_prog->expected_attach_type) {
9372                 err = -EINVAL;
9373                 goto out_unlock;
9374         }
9375
9376         if (old_prog == new_prog) {
9377                 /* no-op, don't disturb drivers */
9378                 bpf_prog_put(new_prog);
9379                 goto out_unlock;
9380         }
9381
9382         mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9383         bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9384         err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9385                               xdp_link->flags, new_prog);
9386         if (err)
9387                 goto out_unlock;
9388
9389         old_prog = xchg(&link->prog, new_prog);
9390         bpf_prog_put(old_prog);
9391
9392 out_unlock:
9393         rtnl_unlock();
9394         return err;
9395 }
9396
9397 static const struct bpf_link_ops bpf_xdp_link_lops = {
9398         .release = bpf_xdp_link_release,
9399         .dealloc = bpf_xdp_link_dealloc,
9400         .detach = bpf_xdp_link_detach,
9401         .show_fdinfo = bpf_xdp_link_show_fdinfo,
9402         .fill_link_info = bpf_xdp_link_fill_link_info,
9403         .update_prog = bpf_xdp_link_update,
9404 };
9405
9406 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9407 {
9408         struct net *net = current->nsproxy->net_ns;
9409         struct bpf_link_primer link_primer;
9410         struct bpf_xdp_link *link;
9411         struct net_device *dev;
9412         int err, fd;
9413
9414         rtnl_lock();
9415         dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9416         if (!dev) {
9417                 rtnl_unlock();
9418                 return -EINVAL;
9419         }
9420
9421         link = kzalloc(sizeof(*link), GFP_USER);
9422         if (!link) {
9423                 err = -ENOMEM;
9424                 goto unlock;
9425         }
9426
9427         bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9428         link->dev = dev;
9429         link->flags = attr->link_create.flags;
9430
9431         err = bpf_link_prime(&link->link, &link_primer);
9432         if (err) {
9433                 kfree(link);
9434                 goto unlock;
9435         }
9436
9437         err = dev_xdp_attach_link(dev, NULL, link);
9438         rtnl_unlock();
9439
9440         if (err) {
9441                 link->dev = NULL;
9442                 bpf_link_cleanup(&link_primer);
9443                 goto out_put_dev;
9444         }
9445
9446         fd = bpf_link_settle(&link_primer);
9447         /* link itself doesn't hold dev's refcnt to not complicate shutdown */
9448         dev_put(dev);
9449         return fd;
9450
9451 unlock:
9452         rtnl_unlock();
9453
9454 out_put_dev:
9455         dev_put(dev);
9456         return err;
9457 }
9458
9459 /**
9460  *      dev_change_xdp_fd - set or clear a bpf program for a device rx path
9461  *      @dev: device
9462  *      @extack: netlink extended ack
9463  *      @fd: new program fd or negative value to clear
9464  *      @expected_fd: old program fd that userspace expects to replace or clear
9465  *      @flags: xdp-related flags
9466  *
9467  *      Set or clear a bpf program for a device
9468  */
9469 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9470                       int fd, int expected_fd, u32 flags)
9471 {
9472         enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9473         struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9474         int err;
9475
9476         ASSERT_RTNL();
9477
9478         if (fd >= 0) {
9479                 new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9480                                                  mode != XDP_MODE_SKB);
9481                 if (IS_ERR(new_prog))
9482                         return PTR_ERR(new_prog);
9483         }
9484
9485         if (expected_fd >= 0) {
9486                 old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9487                                                  mode != XDP_MODE_SKB);
9488                 if (IS_ERR(old_prog)) {
9489                         err = PTR_ERR(old_prog);
9490                         old_prog = NULL;
9491                         goto err_out;
9492                 }
9493         }
9494
9495         err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9496
9497 err_out:
9498         if (err && new_prog)
9499                 bpf_prog_put(new_prog);
9500         if (old_prog)
9501                 bpf_prog_put(old_prog);
9502         return err;
9503 }
9504
9505 /**
9506  *      dev_new_index   -       allocate an ifindex
9507  *      @net: the applicable net namespace
9508  *
9509  *      Returns a suitable unique value for a new device interface
9510  *      number.  The caller must hold the rtnl semaphore or the
9511  *      dev_base_lock to be sure it remains unique.
9512  */
9513 static int dev_new_index(struct net *net)
9514 {
9515         int ifindex = net->ifindex;
9516
9517         for (;;) {
9518                 if (++ifindex <= 0)
9519                         ifindex = 1;
9520                 if (!__dev_get_by_index(net, ifindex))
9521                         return net->ifindex = ifindex;
9522         }
9523 }
9524
9525 /* Delayed registration/unregisteration */
9526 LIST_HEAD(net_todo_list);
9527 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9528
9529 static void net_set_todo(struct net_device *dev)
9530 {
9531         list_add_tail(&dev->todo_list, &net_todo_list);
9532         atomic_inc(&dev_net(dev)->dev_unreg_count);
9533 }
9534
9535 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9536         struct net_device *upper, netdev_features_t features)
9537 {
9538         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9539         netdev_features_t feature;
9540         int feature_bit;
9541
9542         for_each_netdev_feature(upper_disables, feature_bit) {
9543                 feature = __NETIF_F_BIT(feature_bit);
9544                 if (!(upper->wanted_features & feature)
9545                     && (features & feature)) {
9546                         netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9547                                    &feature, upper->name);
9548                         features &= ~feature;
9549                 }
9550         }
9551
9552         return features;
9553 }
9554
9555 static void netdev_sync_lower_features(struct net_device *upper,
9556         struct net_device *lower, netdev_features_t features)
9557 {
9558         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9559         netdev_features_t feature;
9560         int feature_bit;
9561
9562         for_each_netdev_feature(upper_disables, feature_bit) {
9563                 feature = __NETIF_F_BIT(feature_bit);
9564                 if (!(features & feature) && (lower->features & feature)) {
9565                         netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9566                                    &feature, lower->name);
9567                         lower->wanted_features &= ~feature;
9568                         __netdev_update_features(lower);
9569
9570                         if (unlikely(lower->features & feature))
9571                                 netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9572                                             &feature, lower->name);
9573                         else
9574                                 netdev_features_change(lower);
9575                 }
9576         }
9577 }
9578
9579 static netdev_features_t netdev_fix_features(struct net_device *dev,
9580         netdev_features_t features)
9581 {
9582         /* Fix illegal checksum combinations */
9583         if ((features & NETIF_F_HW_CSUM) &&
9584             (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9585                 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9586                 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9587         }
9588
9589         /* TSO requires that SG is present as well. */
9590         if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9591                 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9592                 features &= ~NETIF_F_ALL_TSO;
9593         }
9594
9595         if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9596                                         !(features & NETIF_F_IP_CSUM)) {
9597                 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9598                 features &= ~NETIF_F_TSO;
9599                 features &= ~NETIF_F_TSO_ECN;
9600         }
9601
9602         if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9603                                          !(features & NETIF_F_IPV6_CSUM)) {
9604                 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9605                 features &= ~NETIF_F_TSO6;
9606         }
9607
9608         /* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9609         if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9610                 features &= ~NETIF_F_TSO_MANGLEID;
9611
9612         /* TSO ECN requires that TSO is present as well. */
9613         if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9614                 features &= ~NETIF_F_TSO_ECN;
9615
9616         /* Software GSO depends on SG. */
9617         if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9618                 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9619                 features &= ~NETIF_F_GSO;
9620         }
9621
9622         /* GSO partial features require GSO partial be set */
9623         if ((features & dev->gso_partial_features) &&
9624             !(features & NETIF_F_GSO_PARTIAL)) {
9625                 netdev_dbg(dev,
9626                            "Dropping partially supported GSO features since no GSO partial.\n");
9627                 features &= ~dev->gso_partial_features;
9628         }
9629
9630         if (!(features & NETIF_F_RXCSUM)) {
9631                 /* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9632                  * successfully merged by hardware must also have the
9633                  * checksum verified by hardware.  If the user does not
9634                  * want to enable RXCSUM, logically, we should disable GRO_HW.
9635                  */
9636                 if (features & NETIF_F_GRO_HW) {
9637                         netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9638                         features &= ~NETIF_F_GRO_HW;
9639                 }
9640         }
9641
9642         /* LRO/HW-GRO features cannot be combined with RX-FCS */
9643         if (features & NETIF_F_RXFCS) {
9644                 if (features & NETIF_F_LRO) {
9645                         netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9646                         features &= ~NETIF_F_LRO;
9647                 }
9648
9649                 if (features & NETIF_F_GRO_HW) {
9650                         netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9651                         features &= ~NETIF_F_GRO_HW;
9652                 }
9653         }
9654
9655         if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9656                 netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9657                 features &= ~NETIF_F_LRO;
9658         }
9659
9660         if (features & NETIF_F_HW_TLS_TX) {
9661                 bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9662                         (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9663                 bool hw_csum = features & NETIF_F_HW_CSUM;
9664
9665                 if (!ip_csum && !hw_csum) {
9666                         netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9667                         features &= ~NETIF_F_HW_TLS_TX;
9668                 }
9669         }
9670
9671         if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9672                 netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9673                 features &= ~NETIF_F_HW_TLS_RX;
9674         }
9675
9676         return features;
9677 }
9678
9679 int __netdev_update_features(struct net_device *dev)
9680 {
9681         struct net_device *upper, *lower;
9682         netdev_features_t features;
9683         struct list_head *iter;
9684         int err = -1;
9685
9686         ASSERT_RTNL();
9687
9688         features = netdev_get_wanted_features(dev);
9689
9690         if (dev->netdev_ops->ndo_fix_features)
9691                 features = dev->netdev_ops->ndo_fix_features(dev, features);
9692
9693         /* driver might be less strict about feature dependencies */
9694         features = netdev_fix_features(dev, features);
9695
9696         /* some features can't be enabled if they're off on an upper device */
9697         netdev_for_each_upper_dev_rcu(dev, upper, iter)
9698                 features = netdev_sync_upper_features(dev, upper, features);
9699
9700         if (dev->features == features)
9701                 goto sync_lower;
9702
9703         netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9704                 &dev->features, &features);
9705
9706         if (dev->netdev_ops->ndo_set_features)
9707                 err = dev->netdev_ops->ndo_set_features(dev, features);
9708         else
9709                 err = 0;
9710
9711         if (unlikely(err < 0)) {
9712                 netdev_err(dev,
9713                         "set_features() failed (%d); wanted %pNF, left %pNF\n",
9714                         err, &features, &dev->features);
9715                 /* return non-0 since some features might have changed and
9716                  * it's better to fire a spurious notification than miss it
9717                  */
9718                 return -1;
9719         }
9720
9721 sync_lower:
9722         /* some features must be disabled on lower devices when disabled
9723          * on an upper device (think: bonding master or bridge)
9724          */
9725         netdev_for_each_lower_dev(dev, lower, iter)
9726                 netdev_sync_lower_features(dev, lower, features);
9727
9728         if (!err) {
9729                 netdev_features_t diff = features ^ dev->features;
9730
9731                 if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9732                         /* udp_tunnel_{get,drop}_rx_info both need
9733                          * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9734                          * device, or they won't do anything.
9735                          * Thus we need to update dev->features
9736                          * *before* calling udp_tunnel_get_rx_info,
9737                          * but *after* calling udp_tunnel_drop_rx_info.
9738                          */
9739                         if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9740                                 dev->features = features;
9741                                 udp_tunnel_get_rx_info(dev);
9742                         } else {
9743                                 udp_tunnel_drop_rx_info(dev);
9744                         }
9745                 }
9746
9747                 if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9748                         if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9749                                 dev->features = features;
9750                                 err |= vlan_get_rx_ctag_filter_info(dev);
9751                         } else {
9752                                 vlan_drop_rx_ctag_filter_info(dev);
9753                         }
9754                 }
9755
9756                 if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9757                         if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9758                                 dev->features = features;
9759                                 err |= vlan_get_rx_stag_filter_info(dev);
9760                         } else {
9761                                 vlan_drop_rx_stag_filter_info(dev);
9762                         }
9763                 }
9764
9765                 dev->features = features;
9766         }
9767
9768         return err < 0 ? 0 : 1;
9769 }
9770
9771 /**
9772  *      netdev_update_features - recalculate device features
9773  *      @dev: the device to check
9774  *
9775  *      Recalculate dev->features set and send notifications if it
9776  *      has changed. Should be called after driver or hardware dependent
9777  *      conditions might have changed that influence the features.
9778  */
9779 void netdev_update_features(struct net_device *dev)
9780 {
9781         if (__netdev_update_features(dev))
9782                 netdev_features_change(dev);
9783 }
9784 EXPORT_SYMBOL(netdev_update_features);
9785
9786 /**
9787  *      netdev_change_features - recalculate device features
9788  *      @dev: the device to check
9789  *
9790  *      Recalculate dev->features set and send notifications even
9791  *      if they have not changed. Should be called instead of
9792  *      netdev_update_features() if also dev->vlan_features might
9793  *      have changed to allow the changes to be propagated to stacked
9794  *      VLAN devices.
9795  */
9796 void netdev_change_features(struct net_device *dev)
9797 {
9798         __netdev_update_features(dev);
9799         netdev_features_change(dev);
9800 }
9801 EXPORT_SYMBOL(netdev_change_features);
9802
9803 /**
9804  *      netif_stacked_transfer_operstate -      transfer operstate
9805  *      @rootdev: the root or lower level device to transfer state from
9806  *      @dev: the device to transfer operstate to
9807  *
9808  *      Transfer operational state from root to device. This is normally
9809  *      called when a stacking relationship exists between the root
9810  *      device and the device(a leaf device).
9811  */
9812 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9813                                         struct net_device *dev)
9814 {
9815         if (rootdev->operstate == IF_OPER_DORMANT)
9816                 netif_dormant_on(dev);
9817         else
9818                 netif_dormant_off(dev);
9819
9820         if (rootdev->operstate == IF_OPER_TESTING)
9821                 netif_testing_on(dev);
9822         else
9823                 netif_testing_off(dev);
9824
9825         if (netif_carrier_ok(rootdev))
9826                 netif_carrier_on(dev);
9827         else
9828                 netif_carrier_off(dev);
9829 }
9830 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9831
9832 static int netif_alloc_rx_queues(struct net_device *dev)
9833 {
9834         unsigned int i, count = dev->num_rx_queues;
9835         struct netdev_rx_queue *rx;
9836         size_t sz = count * sizeof(*rx);
9837         int err = 0;
9838
9839         BUG_ON(count < 1);
9840
9841         rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9842         if (!rx)
9843                 return -ENOMEM;
9844
9845         dev->_rx = rx;
9846
9847         for (i = 0; i < count; i++) {
9848                 rx[i].dev = dev;
9849
9850                 /* XDP RX-queue setup */
9851                 err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9852                 if (err < 0)
9853                         goto err_rxq_info;
9854         }
9855         return 0;
9856
9857 err_rxq_info:
9858         /* Rollback successful reg's and free other resources */
9859         while (i--)
9860                 xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9861         kvfree(dev->_rx);
9862         dev->_rx = NULL;
9863         return err;
9864 }
9865
9866 static void netif_free_rx_queues(struct net_device *dev)
9867 {
9868         unsigned int i, count = dev->num_rx_queues;
9869
9870         /* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9871         if (!dev->_rx)
9872                 return;
9873
9874         for (i = 0; i < count; i++)
9875                 xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9876
9877         kvfree(dev->_rx);
9878 }
9879
9880 static void netdev_init_one_queue(struct net_device *dev,
9881                                   struct netdev_queue *queue, void *_unused)
9882 {
9883         /* Initialize queue lock */
9884         spin_lock_init(&queue->_xmit_lock);
9885         netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9886         queue->xmit_lock_owner = -1;
9887         netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9888         queue->dev = dev;
9889 #ifdef CONFIG_BQL
9890         dql_init(&queue->dql, HZ);
9891 #endif
9892 }
9893
9894 static void netif_free_tx_queues(struct net_device *dev)
9895 {
9896         kvfree(dev->_tx);
9897 }
9898
9899 static int netif_alloc_netdev_queues(struct net_device *dev)
9900 {
9901         unsigned int count = dev->num_tx_queues;
9902         struct netdev_queue *tx;
9903         size_t sz = count * sizeof(*tx);
9904
9905         if (count < 1 || count > 0xffff)
9906                 return -EINVAL;
9907
9908         tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9909         if (!tx)
9910                 return -ENOMEM;
9911
9912         dev->_tx = tx;
9913
9914         netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
9915         spin_lock_init(&dev->tx_global_lock);
9916
9917         return 0;
9918 }
9919
9920 void netif_tx_stop_all_queues(struct net_device *dev)
9921 {
9922         unsigned int i;
9923
9924         for (i = 0; i < dev->num_tx_queues; i++) {
9925                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
9926
9927                 netif_tx_stop_queue(txq);
9928         }
9929 }
9930 EXPORT_SYMBOL(netif_tx_stop_all_queues);
9931
9932 /**
9933  * register_netdevice() - register a network device
9934  * @dev: device to register
9935  *
9936  * Take a prepared network device structure and make it externally accessible.
9937  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
9938  * Callers must hold the rtnl lock - you may want register_netdev()
9939  * instead of this.
9940  */
9941 int register_netdevice(struct net_device *dev)
9942 {
9943         int ret;
9944         struct net *net = dev_net(dev);
9945
9946         BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
9947                      NETDEV_FEATURE_COUNT);
9948         BUG_ON(dev_boot_phase);
9949         ASSERT_RTNL();
9950
9951         might_sleep();
9952
9953         /* When net_device's are persistent, this will be fatal. */
9954         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
9955         BUG_ON(!net);
9956
9957         ret = ethtool_check_ops(dev->ethtool_ops);
9958         if (ret)
9959                 return ret;
9960
9961         spin_lock_init(&dev->addr_list_lock);
9962         netdev_set_addr_lockdep_class(dev);
9963
9964         ret = dev_get_valid_name(net, dev, dev->name);
9965         if (ret < 0)
9966                 goto out;
9967
9968         ret = -ENOMEM;
9969         dev->name_node = netdev_name_node_head_alloc(dev);
9970         if (!dev->name_node)
9971                 goto out;
9972
9973         /* Init, if this function is available */
9974         if (dev->netdev_ops->ndo_init) {
9975                 ret = dev->netdev_ops->ndo_init(dev);
9976                 if (ret) {
9977                         if (ret > 0)
9978                                 ret = -EIO;
9979                         goto err_free_name;
9980                 }
9981         }
9982
9983         if (((dev->hw_features | dev->features) &
9984              NETIF_F_HW_VLAN_CTAG_FILTER) &&
9985             (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
9986              !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
9987                 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
9988                 ret = -EINVAL;
9989                 goto err_uninit;
9990         }
9991
9992         ret = -EBUSY;
9993         if (!dev->ifindex)
9994                 dev->ifindex = dev_new_index(net);
9995         else if (__dev_get_by_index(net, dev->ifindex))
9996                 goto err_uninit;
9997
9998         /* Transfer changeable features to wanted_features and enable
9999          * software offloads (GSO and GRO).
10000          */
10001         dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10002         dev->features |= NETIF_F_SOFT_FEATURES;
10003
10004         if (dev->udp_tunnel_nic_info) {
10005                 dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10006                 dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10007         }
10008
10009         dev->wanted_features = dev->features & dev->hw_features;
10010
10011         if (!(dev->flags & IFF_LOOPBACK))
10012                 dev->hw_features |= NETIF_F_NOCACHE_COPY;
10013
10014         /* If IPv4 TCP segmentation offload is supported we should also
10015          * allow the device to enable segmenting the frame with the option
10016          * of ignoring a static IP ID value.  This doesn't enable the
10017          * feature itself but allows the user to enable it later.
10018          */
10019         if (dev->hw_features & NETIF_F_TSO)
10020                 dev->hw_features |= NETIF_F_TSO_MANGLEID;
10021         if (dev->vlan_features & NETIF_F_TSO)
10022                 dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10023         if (dev->mpls_features & NETIF_F_TSO)
10024                 dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10025         if (dev->hw_enc_features & NETIF_F_TSO)
10026                 dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10027
10028         /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10029          */
10030         dev->vlan_features |= NETIF_F_HIGHDMA;
10031
10032         /* Make NETIF_F_SG inheritable to tunnel devices.
10033          */
10034         dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10035
10036         /* Make NETIF_F_SG inheritable to MPLS.
10037          */
10038         dev->mpls_features |= NETIF_F_SG;
10039
10040         ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10041         ret = notifier_to_errno(ret);
10042         if (ret)
10043                 goto err_uninit;
10044
10045         ret = netdev_register_kobject(dev);
10046         if (ret) {
10047                 dev->reg_state = NETREG_UNREGISTERED;
10048                 goto err_uninit;
10049         }
10050         dev->reg_state = NETREG_REGISTERED;
10051
10052         __netdev_update_features(dev);
10053
10054         /*
10055          *      Default initial state at registry is that the
10056          *      device is present.
10057          */
10058
10059         set_bit(__LINK_STATE_PRESENT, &dev->state);
10060
10061         linkwatch_init_dev(dev);
10062
10063         dev_init_scheduler(dev);
10064
10065         dev_hold_track(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10066         list_netdevice(dev);
10067
10068         add_device_randomness(dev->dev_addr, dev->addr_len);
10069
10070         /* If the device has permanent device address, driver should
10071          * set dev_addr and also addr_assign_type should be set to
10072          * NET_ADDR_PERM (default value).
10073          */
10074         if (dev->addr_assign_type == NET_ADDR_PERM)
10075                 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10076
10077         /* Notify protocols, that a new device appeared. */
10078         ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10079         ret = notifier_to_errno(ret);
10080         if (ret) {
10081                 /* Expect explicit free_netdev() on failure */
10082                 dev->needs_free_netdev = false;
10083                 unregister_netdevice_queue(dev, NULL);
10084                 goto out;
10085         }
10086         /*
10087          *      Prevent userspace races by waiting until the network
10088          *      device is fully setup before sending notifications.
10089          */
10090         if (!dev->rtnl_link_ops ||
10091             dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10092                 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
10093
10094 out:
10095         return ret;
10096
10097 err_uninit:
10098         if (dev->netdev_ops->ndo_uninit)
10099                 dev->netdev_ops->ndo_uninit(dev);
10100         if (dev->priv_destructor)
10101                 dev->priv_destructor(dev);
10102 err_free_name:
10103         netdev_name_node_free(dev->name_node);
10104         goto out;
10105 }
10106 EXPORT_SYMBOL(register_netdevice);
10107
10108 /**
10109  *      init_dummy_netdev       - init a dummy network device for NAPI
10110  *      @dev: device to init
10111  *
10112  *      This takes a network device structure and initialize the minimum
10113  *      amount of fields so it can be used to schedule NAPI polls without
10114  *      registering a full blown interface. This is to be used by drivers
10115  *      that need to tie several hardware interfaces to a single NAPI
10116  *      poll scheduler due to HW limitations.
10117  */
10118 int init_dummy_netdev(struct net_device *dev)
10119 {
10120         /* Clear everything. Note we don't initialize spinlocks
10121          * are they aren't supposed to be taken by any of the
10122          * NAPI code and this dummy netdev is supposed to be
10123          * only ever used for NAPI polls
10124          */
10125         memset(dev, 0, sizeof(struct net_device));
10126
10127         /* make sure we BUG if trying to hit standard
10128          * register/unregister code path
10129          */
10130         dev->reg_state = NETREG_DUMMY;
10131
10132         /* NAPI wants this */
10133         INIT_LIST_HEAD(&dev->napi_list);
10134
10135         /* a dummy interface is started by default */
10136         set_bit(__LINK_STATE_PRESENT, &dev->state);
10137         set_bit(__LINK_STATE_START, &dev->state);
10138
10139         /* napi_busy_loop stats accounting wants this */
10140         dev_net_set(dev, &init_net);
10141
10142         /* Note : We dont allocate pcpu_refcnt for dummy devices,
10143          * because users of this 'device' dont need to change
10144          * its refcount.
10145          */
10146
10147         return 0;
10148 }
10149 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10150
10151
10152 /**
10153  *      register_netdev - register a network device
10154  *      @dev: device to register
10155  *
10156  *      Take a completed network device structure and add it to the kernel
10157  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10158  *      chain. 0 is returned on success. A negative errno code is returned
10159  *      on a failure to set up the device, or if the name is a duplicate.
10160  *
10161  *      This is a wrapper around register_netdevice that takes the rtnl semaphore
10162  *      and expands the device name if you passed a format string to
10163  *      alloc_netdev.
10164  */
10165 int register_netdev(struct net_device *dev)
10166 {
10167         int err;
10168
10169         if (rtnl_lock_killable())
10170                 return -EINTR;
10171         err = register_netdevice(dev);
10172         rtnl_unlock();
10173         return err;
10174 }
10175 EXPORT_SYMBOL(register_netdev);
10176
10177 int netdev_refcnt_read(const struct net_device *dev)
10178 {
10179 #ifdef CONFIG_PCPU_DEV_REFCNT
10180         int i, refcnt = 0;
10181
10182         for_each_possible_cpu(i)
10183                 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10184         return refcnt;
10185 #else
10186         return refcount_read(&dev->dev_refcnt);
10187 #endif
10188 }
10189 EXPORT_SYMBOL(netdev_refcnt_read);
10190
10191 int netdev_unregister_timeout_secs __read_mostly = 10;
10192
10193 #define WAIT_REFS_MIN_MSECS 1
10194 #define WAIT_REFS_MAX_MSECS 250
10195 /**
10196  * netdev_wait_allrefs_any - wait until all references are gone.
10197  * @list: list of net_devices to wait on
10198  *
10199  * This is called when unregistering network devices.
10200  *
10201  * Any protocol or device that holds a reference should register
10202  * for netdevice notification, and cleanup and put back the
10203  * reference if they receive an UNREGISTER event.
10204  * We can get stuck here if buggy protocols don't correctly
10205  * call dev_put.
10206  */
10207 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10208 {
10209         unsigned long rebroadcast_time, warning_time;
10210         struct net_device *dev;
10211         int wait = 0;
10212
10213         rebroadcast_time = warning_time = jiffies;
10214
10215         list_for_each_entry(dev, list, todo_list)
10216                 if (netdev_refcnt_read(dev) == 1)
10217                         return dev;
10218
10219         while (true) {
10220                 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10221                         rtnl_lock();
10222
10223                         /* Rebroadcast unregister notification */
10224                         list_for_each_entry(dev, list, todo_list)
10225                                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10226
10227                         __rtnl_unlock();
10228                         rcu_barrier();
10229                         rtnl_lock();
10230
10231                         list_for_each_entry(dev, list, todo_list)
10232                                 if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10233                                              &dev->state)) {
10234                                         /* We must not have linkwatch events
10235                                          * pending on unregister. If this
10236                                          * happens, we simply run the queue
10237                                          * unscheduled, resulting in a noop
10238                                          * for this device.
10239                                          */
10240                                         linkwatch_run_queue();
10241                                         break;
10242                                 }
10243
10244                         __rtnl_unlock();
10245
10246                         rebroadcast_time = jiffies;
10247                 }
10248
10249                 if (!wait) {
10250                         rcu_barrier();
10251                         wait = WAIT_REFS_MIN_MSECS;
10252                 } else {
10253                         msleep(wait);
10254                         wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10255                 }
10256
10257                 list_for_each_entry(dev, list, todo_list)
10258                         if (netdev_refcnt_read(dev) == 1)
10259                                 return dev;
10260
10261                 if (time_after(jiffies, warning_time +
10262                                netdev_unregister_timeout_secs * HZ)) {
10263                         list_for_each_entry(dev, list, todo_list) {
10264                                 pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10265                                          dev->name, netdev_refcnt_read(dev));
10266                                 ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10267                         }
10268
10269                         warning_time = jiffies;
10270                 }
10271         }
10272 }
10273
10274 /* The sequence is:
10275  *
10276  *      rtnl_lock();
10277  *      ...
10278  *      register_netdevice(x1);
10279  *      register_netdevice(x2);
10280  *      ...
10281  *      unregister_netdevice(y1);
10282  *      unregister_netdevice(y2);
10283  *      ...
10284  *      rtnl_unlock();
10285  *      free_netdev(y1);
10286  *      free_netdev(y2);
10287  *
10288  * We are invoked by rtnl_unlock().
10289  * This allows us to deal with problems:
10290  * 1) We can delete sysfs objects which invoke hotplug
10291  *    without deadlocking with linkwatch via keventd.
10292  * 2) Since we run with the RTNL semaphore not held, we can sleep
10293  *    safely in order to wait for the netdev refcnt to drop to zero.
10294  *
10295  * We must not return until all unregister events added during
10296  * the interval the lock was held have been completed.
10297  */
10298 void netdev_run_todo(void)
10299 {
10300         struct net_device *dev, *tmp;
10301         struct list_head list;
10302 #ifdef CONFIG_LOCKDEP
10303         struct list_head unlink_list;
10304
10305         list_replace_init(&net_unlink_list, &unlink_list);
10306
10307         while (!list_empty(&unlink_list)) {
10308                 struct net_device *dev = list_first_entry(&unlink_list,
10309                                                           struct net_device,
10310                                                           unlink_list);
10311                 list_del_init(&dev->unlink_list);
10312                 dev->nested_level = dev->lower_level - 1;
10313         }
10314 #endif
10315
10316         /* Snapshot list, allow later requests */
10317         list_replace_init(&net_todo_list, &list);
10318
10319         __rtnl_unlock();
10320
10321         /* Wait for rcu callbacks to finish before next phase */
10322         if (!list_empty(&list))
10323                 rcu_barrier();
10324
10325         list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10326                 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10327                         netdev_WARN(dev, "run_todo but not unregistering\n");
10328                         list_del(&dev->todo_list);
10329                         continue;
10330                 }
10331
10332                 dev->reg_state = NETREG_UNREGISTERED;
10333                 linkwatch_forget_dev(dev);
10334         }
10335
10336         while (!list_empty(&list)) {
10337                 dev = netdev_wait_allrefs_any(&list);
10338                 list_del(&dev->todo_list);
10339
10340                 /* paranoia */
10341                 BUG_ON(netdev_refcnt_read(dev) != 1);
10342                 BUG_ON(!list_empty(&dev->ptype_all));
10343                 BUG_ON(!list_empty(&dev->ptype_specific));
10344                 WARN_ON(rcu_access_pointer(dev->ip_ptr));
10345                 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10346 #if IS_ENABLED(CONFIG_DECNET)
10347                 WARN_ON(dev->dn_ptr);
10348 #endif
10349                 if (dev->priv_destructor)
10350                         dev->priv_destructor(dev);
10351                 if (dev->needs_free_netdev)
10352                         free_netdev(dev);
10353
10354                 if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10355                         wake_up(&netdev_unregistering_wq);
10356
10357                 /* Free network device */
10358                 kobject_put(&dev->dev.kobj);
10359         }
10360 }
10361
10362 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10363  * all the same fields in the same order as net_device_stats, with only
10364  * the type differing, but rtnl_link_stats64 may have additional fields
10365  * at the end for newer counters.
10366  */
10367 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10368                              const struct net_device_stats *netdev_stats)
10369 {
10370 #if BITS_PER_LONG == 64
10371         BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats));
10372         memcpy(stats64, netdev_stats, sizeof(*netdev_stats));
10373         /* zero out counters that only exist in rtnl_link_stats64 */
10374         memset((char *)stats64 + sizeof(*netdev_stats), 0,
10375                sizeof(*stats64) - sizeof(*netdev_stats));
10376 #else
10377         size_t i, n = sizeof(*netdev_stats) / sizeof(unsigned long);
10378         const unsigned long *src = (const unsigned long *)netdev_stats;
10379         u64 *dst = (u64 *)stats64;
10380
10381         BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10382         for (i = 0; i < n; i++)
10383                 dst[i] = src[i];
10384         /* zero out counters that only exist in rtnl_link_stats64 */
10385         memset((char *)stats64 + n * sizeof(u64), 0,
10386                sizeof(*stats64) - n * sizeof(u64));
10387 #endif
10388 }
10389 EXPORT_SYMBOL(netdev_stats_to_stats64);
10390
10391 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10392 {
10393         struct net_device_core_stats __percpu *p;
10394
10395         p = alloc_percpu_gfp(struct net_device_core_stats,
10396                              GFP_ATOMIC | __GFP_NOWARN);
10397
10398         if (p && cmpxchg(&dev->core_stats, NULL, p))
10399                 free_percpu(p);
10400
10401         /* This READ_ONCE() pairs with the cmpxchg() above */
10402         return READ_ONCE(dev->core_stats);
10403 }
10404 EXPORT_SYMBOL(netdev_core_stats_alloc);
10405
10406 /**
10407  *      dev_get_stats   - get network device statistics
10408  *      @dev: device to get statistics from
10409  *      @storage: place to store stats
10410  *
10411  *      Get network statistics from device. Return @storage.
10412  *      The device driver may provide its own method by setting
10413  *      dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10414  *      otherwise the internal statistics structure is used.
10415  */
10416 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10417                                         struct rtnl_link_stats64 *storage)
10418 {
10419         const struct net_device_ops *ops = dev->netdev_ops;
10420         const struct net_device_core_stats __percpu *p;
10421
10422         if (ops->ndo_get_stats64) {
10423                 memset(storage, 0, sizeof(*storage));
10424                 ops->ndo_get_stats64(dev, storage);
10425         } else if (ops->ndo_get_stats) {
10426                 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10427         } else {
10428                 netdev_stats_to_stats64(storage, &dev->stats);
10429         }
10430
10431         /* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10432         p = READ_ONCE(dev->core_stats);
10433         if (p) {
10434                 const struct net_device_core_stats *core_stats;
10435                 int i;
10436
10437                 for_each_possible_cpu(i) {
10438                         core_stats = per_cpu_ptr(p, i);
10439                         storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10440                         storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10441                         storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10442                         storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10443                 }
10444         }
10445         return storage;
10446 }
10447 EXPORT_SYMBOL(dev_get_stats);
10448
10449 /**
10450  *      dev_fetch_sw_netstats - get per-cpu network device statistics
10451  *      @s: place to store stats
10452  *      @netstats: per-cpu network stats to read from
10453  *
10454  *      Read per-cpu network statistics and populate the related fields in @s.
10455  */
10456 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10457                            const struct pcpu_sw_netstats __percpu *netstats)
10458 {
10459         int cpu;
10460
10461         for_each_possible_cpu(cpu) {
10462                 const struct pcpu_sw_netstats *stats;
10463                 struct pcpu_sw_netstats tmp;
10464                 unsigned int start;
10465
10466                 stats = per_cpu_ptr(netstats, cpu);
10467                 do {
10468                         start = u64_stats_fetch_begin_irq(&stats->syncp);
10469                         tmp.rx_packets = stats->rx_packets;
10470                         tmp.rx_bytes   = stats->rx_bytes;
10471                         tmp.tx_packets = stats->tx_packets;
10472                         tmp.tx_bytes   = stats->tx_bytes;
10473                 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
10474
10475                 s->rx_packets += tmp.rx_packets;
10476                 s->rx_bytes   += tmp.rx_bytes;
10477                 s->tx_packets += tmp.tx_packets;
10478                 s->tx_bytes   += tmp.tx_bytes;
10479         }
10480 }
10481 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10482
10483 /**
10484  *      dev_get_tstats64 - ndo_get_stats64 implementation
10485  *      @dev: device to get statistics from
10486  *      @s: place to store stats
10487  *
10488  *      Populate @s from dev->stats and dev->tstats. Can be used as
10489  *      ndo_get_stats64() callback.
10490  */
10491 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10492 {
10493         netdev_stats_to_stats64(s, &dev->stats);
10494         dev_fetch_sw_netstats(s, dev->tstats);
10495 }
10496 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10497
10498 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10499 {
10500         struct netdev_queue *queue = dev_ingress_queue(dev);
10501
10502 #ifdef CONFIG_NET_CLS_ACT
10503         if (queue)
10504                 return queue;
10505         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10506         if (!queue)
10507                 return NULL;
10508         netdev_init_one_queue(dev, queue, NULL);
10509         RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10510         queue->qdisc_sleeping = &noop_qdisc;
10511         rcu_assign_pointer(dev->ingress_queue, queue);
10512 #endif
10513         return queue;
10514 }
10515
10516 static const struct ethtool_ops default_ethtool_ops;
10517
10518 void netdev_set_default_ethtool_ops(struct net_device *dev,
10519                                     const struct ethtool_ops *ops)
10520 {
10521         if (dev->ethtool_ops == &default_ethtool_ops)
10522                 dev->ethtool_ops = ops;
10523 }
10524 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10525
10526 void netdev_freemem(struct net_device *dev)
10527 {
10528         char *addr = (char *)dev - dev->padded;
10529
10530         kvfree(addr);
10531 }
10532
10533 /**
10534  * alloc_netdev_mqs - allocate network device
10535  * @sizeof_priv: size of private data to allocate space for
10536  * @name: device name format string
10537  * @name_assign_type: origin of device name
10538  * @setup: callback to initialize device
10539  * @txqs: the number of TX subqueues to allocate
10540  * @rxqs: the number of RX subqueues to allocate
10541  *
10542  * Allocates a struct net_device with private data area for driver use
10543  * and performs basic initialization.  Also allocates subqueue structs
10544  * for each queue on the device.
10545  */
10546 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10547                 unsigned char name_assign_type,
10548                 void (*setup)(struct net_device *),
10549                 unsigned int txqs, unsigned int rxqs)
10550 {
10551         struct net_device *dev;
10552         unsigned int alloc_size;
10553         struct net_device *p;
10554
10555         BUG_ON(strlen(name) >= sizeof(dev->name));
10556
10557         if (txqs < 1) {
10558                 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10559                 return NULL;
10560         }
10561
10562         if (rxqs < 1) {
10563                 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10564                 return NULL;
10565         }
10566
10567         alloc_size = sizeof(struct net_device);
10568         if (sizeof_priv) {
10569                 /* ensure 32-byte alignment of private area */
10570                 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10571                 alloc_size += sizeof_priv;
10572         }
10573         /* ensure 32-byte alignment of whole construct */
10574         alloc_size += NETDEV_ALIGN - 1;
10575
10576         p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10577         if (!p)
10578                 return NULL;
10579
10580         dev = PTR_ALIGN(p, NETDEV_ALIGN);
10581         dev->padded = (char *)dev - (char *)p;
10582
10583         ref_tracker_dir_init(&dev->refcnt_tracker, 128);
10584 #ifdef CONFIG_PCPU_DEV_REFCNT
10585         dev->pcpu_refcnt = alloc_percpu(int);
10586         if (!dev->pcpu_refcnt)
10587                 goto free_dev;
10588         __dev_hold(dev);
10589 #else
10590         refcount_set(&dev->dev_refcnt, 1);
10591 #endif
10592
10593         if (dev_addr_init(dev))
10594                 goto free_pcpu;
10595
10596         dev_mc_init(dev);
10597         dev_uc_init(dev);
10598
10599         dev_net_set(dev, &init_net);
10600
10601         dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10602         dev->gso_max_segs = GSO_MAX_SEGS;
10603         dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10604         dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10605         dev->tso_max_segs = TSO_MAX_SEGS;
10606         dev->upper_level = 1;
10607         dev->lower_level = 1;
10608 #ifdef CONFIG_LOCKDEP
10609         dev->nested_level = 0;
10610         INIT_LIST_HEAD(&dev->unlink_list);
10611 #endif
10612
10613         INIT_LIST_HEAD(&dev->napi_list);
10614         INIT_LIST_HEAD(&dev->unreg_list);
10615         INIT_LIST_HEAD(&dev->close_list);
10616         INIT_LIST_HEAD(&dev->link_watch_list);
10617         INIT_LIST_HEAD(&dev->adj_list.upper);
10618         INIT_LIST_HEAD(&dev->adj_list.lower);
10619         INIT_LIST_HEAD(&dev->ptype_all);
10620         INIT_LIST_HEAD(&dev->ptype_specific);
10621         INIT_LIST_HEAD(&dev->net_notifier_list);
10622 #ifdef CONFIG_NET_SCHED
10623         hash_init(dev->qdisc_hash);
10624 #endif
10625         dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10626         setup(dev);
10627
10628         if (!dev->tx_queue_len) {
10629                 dev->priv_flags |= IFF_NO_QUEUE;
10630                 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10631         }
10632
10633         dev->num_tx_queues = txqs;
10634         dev->real_num_tx_queues = txqs;
10635         if (netif_alloc_netdev_queues(dev))
10636                 goto free_all;
10637
10638         dev->num_rx_queues = rxqs;
10639         dev->real_num_rx_queues = rxqs;
10640         if (netif_alloc_rx_queues(dev))
10641                 goto free_all;
10642
10643         strcpy(dev->name, name);
10644         dev->name_assign_type = name_assign_type;
10645         dev->group = INIT_NETDEV_GROUP;
10646         if (!dev->ethtool_ops)
10647                 dev->ethtool_ops = &default_ethtool_ops;
10648
10649         nf_hook_netdev_init(dev);
10650
10651         return dev;
10652
10653 free_all:
10654         free_netdev(dev);
10655         return NULL;
10656
10657 free_pcpu:
10658 #ifdef CONFIG_PCPU_DEV_REFCNT
10659         free_percpu(dev->pcpu_refcnt);
10660 free_dev:
10661 #endif
10662         netdev_freemem(dev);
10663         return NULL;
10664 }
10665 EXPORT_SYMBOL(alloc_netdev_mqs);
10666
10667 /**
10668  * free_netdev - free network device
10669  * @dev: device
10670  *
10671  * This function does the last stage of destroying an allocated device
10672  * interface. The reference to the device object is released. If this
10673  * is the last reference then it will be freed.Must be called in process
10674  * context.
10675  */
10676 void free_netdev(struct net_device *dev)
10677 {
10678         struct napi_struct *p, *n;
10679
10680         might_sleep();
10681
10682         /* When called immediately after register_netdevice() failed the unwind
10683          * handling may still be dismantling the device. Handle that case by
10684          * deferring the free.
10685          */
10686         if (dev->reg_state == NETREG_UNREGISTERING) {
10687                 ASSERT_RTNL();
10688                 dev->needs_free_netdev = true;
10689                 return;
10690         }
10691
10692         netif_free_tx_queues(dev);
10693         netif_free_rx_queues(dev);
10694
10695         kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10696
10697         /* Flush device addresses */
10698         dev_addr_flush(dev);
10699
10700         list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10701                 netif_napi_del(p);
10702
10703         ref_tracker_dir_exit(&dev->refcnt_tracker);
10704 #ifdef CONFIG_PCPU_DEV_REFCNT
10705         free_percpu(dev->pcpu_refcnt);
10706         dev->pcpu_refcnt = NULL;
10707 #endif
10708         free_percpu(dev->core_stats);
10709         dev->core_stats = NULL;
10710         free_percpu(dev->xdp_bulkq);
10711         dev->xdp_bulkq = NULL;
10712
10713         /*  Compatibility with error handling in drivers */
10714         if (dev->reg_state == NETREG_UNINITIALIZED) {
10715                 netdev_freemem(dev);
10716                 return;
10717         }
10718
10719         BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10720         dev->reg_state = NETREG_RELEASED;
10721
10722         /* will free via device release */
10723         put_device(&dev->dev);
10724 }
10725 EXPORT_SYMBOL(free_netdev);
10726
10727 /**
10728  *      synchronize_net -  Synchronize with packet receive processing
10729  *
10730  *      Wait for packets currently being received to be done.
10731  *      Does not block later packets from starting.
10732  */
10733 void synchronize_net(void)
10734 {
10735         might_sleep();
10736         if (rtnl_is_locked())
10737                 synchronize_rcu_expedited();
10738         else
10739                 synchronize_rcu();
10740 }
10741 EXPORT_SYMBOL(synchronize_net);
10742
10743 /**
10744  *      unregister_netdevice_queue - remove device from the kernel
10745  *      @dev: device
10746  *      @head: list
10747  *
10748  *      This function shuts down a device interface and removes it
10749  *      from the kernel tables.
10750  *      If head not NULL, device is queued to be unregistered later.
10751  *
10752  *      Callers must hold the rtnl semaphore.  You may want
10753  *      unregister_netdev() instead of this.
10754  */
10755
10756 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10757 {
10758         ASSERT_RTNL();
10759
10760         if (head) {
10761                 list_move_tail(&dev->unreg_list, head);
10762         } else {
10763                 LIST_HEAD(single);
10764
10765                 list_add(&dev->unreg_list, &single);
10766                 unregister_netdevice_many(&single);
10767         }
10768 }
10769 EXPORT_SYMBOL(unregister_netdevice_queue);
10770
10771 /**
10772  *      unregister_netdevice_many - unregister many devices
10773  *      @head: list of devices
10774  *
10775  *  Note: As most callers use a stack allocated list_head,
10776  *  we force a list_del() to make sure stack wont be corrupted later.
10777  */
10778 void unregister_netdevice_many(struct list_head *head)
10779 {
10780         struct net_device *dev, *tmp;
10781         LIST_HEAD(close_head);
10782
10783         BUG_ON(dev_boot_phase);
10784         ASSERT_RTNL();
10785
10786         if (list_empty(head))
10787                 return;
10788
10789         list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10790                 /* Some devices call without registering
10791                  * for initialization unwind. Remove those
10792                  * devices and proceed with the remaining.
10793                  */
10794                 if (dev->reg_state == NETREG_UNINITIALIZED) {
10795                         pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10796                                  dev->name, dev);
10797
10798                         WARN_ON(1);
10799                         list_del(&dev->unreg_list);
10800                         continue;
10801                 }
10802                 dev->dismantle = true;
10803                 BUG_ON(dev->reg_state != NETREG_REGISTERED);
10804         }
10805
10806         /* If device is running, close it first. */
10807         list_for_each_entry(dev, head, unreg_list)
10808                 list_add_tail(&dev->close_list, &close_head);
10809         dev_close_many(&close_head, true);
10810
10811         list_for_each_entry(dev, head, unreg_list) {
10812                 /* And unlink it from device chain. */
10813                 unlist_netdevice(dev);
10814
10815                 dev->reg_state = NETREG_UNREGISTERING;
10816         }
10817         flush_all_backlogs();
10818
10819         synchronize_net();
10820
10821         list_for_each_entry(dev, head, unreg_list) {
10822                 struct sk_buff *skb = NULL;
10823
10824                 /* Shutdown queueing discipline. */
10825                 dev_shutdown(dev);
10826
10827                 dev_xdp_uninstall(dev);
10828
10829                 netdev_offload_xstats_disable_all(dev);
10830
10831                 /* Notify protocols, that we are about to destroy
10832                  * this device. They should clean all the things.
10833                  */
10834                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10835
10836                 if (!dev->rtnl_link_ops ||
10837                     dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10838                         skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10839                                                      GFP_KERNEL, NULL, 0);
10840
10841                 /*
10842                  *      Flush the unicast and multicast chains
10843                  */
10844                 dev_uc_flush(dev);
10845                 dev_mc_flush(dev);
10846
10847                 netdev_name_node_alt_flush(dev);
10848                 netdev_name_node_free(dev->name_node);
10849
10850                 if (dev->netdev_ops->ndo_uninit)
10851                         dev->netdev_ops->ndo_uninit(dev);
10852
10853                 if (skb)
10854                         rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
10855
10856                 /* Notifier chain MUST detach us all upper devices. */
10857                 WARN_ON(netdev_has_any_upper_dev(dev));
10858                 WARN_ON(netdev_has_any_lower_dev(dev));
10859
10860                 /* Remove entries from kobject tree */
10861                 netdev_unregister_kobject(dev);
10862 #ifdef CONFIG_XPS
10863                 /* Remove XPS queueing entries */
10864                 netif_reset_xps_queues_gt(dev, 0);
10865 #endif
10866         }
10867
10868         synchronize_net();
10869
10870         list_for_each_entry(dev, head, unreg_list) {
10871                 dev_put_track(dev, &dev->dev_registered_tracker);
10872                 net_set_todo(dev);
10873         }
10874
10875         list_del(head);
10876 }
10877 EXPORT_SYMBOL(unregister_netdevice_many);
10878
10879 /**
10880  *      unregister_netdev - remove device from the kernel
10881  *      @dev: device
10882  *
10883  *      This function shuts down a device interface and removes it
10884  *      from the kernel tables.
10885  *
10886  *      This is just a wrapper for unregister_netdevice that takes
10887  *      the rtnl semaphore.  In general you want to use this and not
10888  *      unregister_netdevice.
10889  */
10890 void unregister_netdev(struct net_device *dev)
10891 {
10892         rtnl_lock();
10893         unregister_netdevice(dev);
10894         rtnl_unlock();
10895 }
10896 EXPORT_SYMBOL(unregister_netdev);
10897
10898 /**
10899  *      __dev_change_net_namespace - move device to different nethost namespace
10900  *      @dev: device
10901  *      @net: network namespace
10902  *      @pat: If not NULL name pattern to try if the current device name
10903  *            is already taken in the destination network namespace.
10904  *      @new_ifindex: If not zero, specifies device index in the target
10905  *                    namespace.
10906  *
10907  *      This function shuts down a device interface and moves it
10908  *      to a new network namespace. On success 0 is returned, on
10909  *      a failure a netagive errno code is returned.
10910  *
10911  *      Callers must hold the rtnl semaphore.
10912  */
10913
10914 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
10915                                const char *pat, int new_ifindex)
10916 {
10917         struct net *net_old = dev_net(dev);
10918         int err, new_nsid;
10919
10920         ASSERT_RTNL();
10921
10922         /* Don't allow namespace local devices to be moved. */
10923         err = -EINVAL;
10924         if (dev->features & NETIF_F_NETNS_LOCAL)
10925                 goto out;
10926
10927         /* Ensure the device has been registrered */
10928         if (dev->reg_state != NETREG_REGISTERED)
10929                 goto out;
10930
10931         /* Get out if there is nothing todo */
10932         err = 0;
10933         if (net_eq(net_old, net))
10934                 goto out;
10935
10936         /* Pick the destination device name, and ensure
10937          * we can use it in the destination network namespace.
10938          */
10939         err = -EEXIST;
10940         if (netdev_name_in_use(net, dev->name)) {
10941                 /* We get here if we can't use the current device name */
10942                 if (!pat)
10943                         goto out;
10944                 err = dev_get_valid_name(net, dev, pat);
10945                 if (err < 0)
10946                         goto out;
10947         }
10948
10949         /* Check that new_ifindex isn't used yet. */
10950         err = -EBUSY;
10951         if (new_ifindex && __dev_get_by_index(net, new_ifindex))
10952                 goto out;
10953
10954         /*
10955          * And now a mini version of register_netdevice unregister_netdevice.
10956          */
10957
10958         /* If device is running close it first. */
10959         dev_close(dev);
10960
10961         /* And unlink it from device chain */
10962         unlist_netdevice(dev);
10963
10964         synchronize_net();
10965
10966         /* Shutdown queueing discipline. */
10967         dev_shutdown(dev);
10968
10969         /* Notify protocols, that we are about to destroy
10970          * this device. They should clean all the things.
10971          *
10972          * Note that dev->reg_state stays at NETREG_REGISTERED.
10973          * This is wanted because this way 8021q and macvlan know
10974          * the device is just moving and can keep their slaves up.
10975          */
10976         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10977         rcu_barrier();
10978
10979         new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
10980         /* If there is an ifindex conflict assign a new one */
10981         if (!new_ifindex) {
10982                 if (__dev_get_by_index(net, dev->ifindex))
10983                         new_ifindex = dev_new_index(net);
10984                 else
10985                         new_ifindex = dev->ifindex;
10986         }
10987
10988         rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
10989                             new_ifindex);
10990
10991         /*
10992          *      Flush the unicast and multicast chains
10993          */
10994         dev_uc_flush(dev);
10995         dev_mc_flush(dev);
10996
10997         /* Send a netdev-removed uevent to the old namespace */
10998         kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
10999         netdev_adjacent_del_links(dev);
11000
11001         /* Move per-net netdevice notifiers that are following the netdevice */
11002         move_netdevice_notifiers_dev_net(dev, net);
11003
11004         /* Actually switch the network namespace */
11005         dev_net_set(dev, net);
11006         dev->ifindex = new_ifindex;
11007
11008         /* Send a netdev-add uevent to the new namespace */
11009         kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11010         netdev_adjacent_add_links(dev);
11011
11012         /* Fixup kobjects */
11013         err = device_rename(&dev->dev, dev->name);
11014         WARN_ON(err);
11015
11016         /* Adapt owner in case owning user namespace of target network
11017          * namespace is different from the original one.
11018          */
11019         err = netdev_change_owner(dev, net_old, net);
11020         WARN_ON(err);
11021
11022         /* Add the device back in the hashes */
11023         list_netdevice(dev);
11024
11025         /* Notify protocols, that a new device appeared. */
11026         call_netdevice_notifiers(NETDEV_REGISTER, dev);
11027
11028         /*
11029          *      Prevent userspace races by waiting until the network
11030          *      device is fully setup before sending notifications.
11031          */
11032         rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
11033
11034         synchronize_net();
11035         err = 0;
11036 out:
11037         return err;
11038 }
11039 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11040
11041 static int dev_cpu_dead(unsigned int oldcpu)
11042 {
11043         struct sk_buff **list_skb;
11044         struct sk_buff *skb;
11045         unsigned int cpu;
11046         struct softnet_data *sd, *oldsd, *remsd = NULL;
11047
11048         local_irq_disable();
11049         cpu = smp_processor_id();
11050         sd = &per_cpu(softnet_data, cpu);
11051         oldsd = &per_cpu(softnet_data, oldcpu);
11052
11053         /* Find end of our completion_queue. */
11054         list_skb = &sd->completion_queue;
11055         while (*list_skb)
11056                 list_skb = &(*list_skb)->next;
11057         /* Append completion queue from offline CPU. */
11058         *list_skb = oldsd->completion_queue;
11059         oldsd->completion_queue = NULL;
11060
11061         /* Append output queue from offline CPU. */
11062         if (oldsd->output_queue) {
11063                 *sd->output_queue_tailp = oldsd->output_queue;
11064                 sd->output_queue_tailp = oldsd->output_queue_tailp;
11065                 oldsd->output_queue = NULL;
11066                 oldsd->output_queue_tailp = &oldsd->output_queue;
11067         }
11068         /* Append NAPI poll list from offline CPU, with one exception :
11069          * process_backlog() must be called by cpu owning percpu backlog.
11070          * We properly handle process_queue & input_pkt_queue later.
11071          */
11072         while (!list_empty(&oldsd->poll_list)) {
11073                 struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11074                                                             struct napi_struct,
11075                                                             poll_list);
11076
11077                 list_del_init(&napi->poll_list);
11078                 if (napi->poll == process_backlog)
11079                         napi->state = 0;
11080                 else
11081                         ____napi_schedule(sd, napi);
11082         }
11083
11084         raise_softirq_irqoff(NET_TX_SOFTIRQ);
11085         local_irq_enable();
11086
11087 #ifdef CONFIG_RPS
11088         remsd = oldsd->rps_ipi_list;
11089         oldsd->rps_ipi_list = NULL;
11090 #endif
11091         /* send out pending IPI's on offline CPU */
11092         net_rps_send_ipi(remsd);
11093
11094         /* Process offline CPU's input_pkt_queue */
11095         while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11096                 netif_rx(skb);
11097                 input_queue_head_incr(oldsd);
11098         }
11099         while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11100                 netif_rx(skb);
11101                 input_queue_head_incr(oldsd);
11102         }
11103
11104         return 0;
11105 }
11106
11107 /**
11108  *      netdev_increment_features - increment feature set by one
11109  *      @all: current feature set
11110  *      @one: new feature set
11111  *      @mask: mask feature set
11112  *
11113  *      Computes a new feature set after adding a device with feature set
11114  *      @one to the master device with current feature set @all.  Will not
11115  *      enable anything that is off in @mask. Returns the new feature set.
11116  */
11117 netdev_features_t netdev_increment_features(netdev_features_t all,
11118         netdev_features_t one, netdev_features_t mask)
11119 {
11120         if (mask & NETIF_F_HW_CSUM)
11121                 mask |= NETIF_F_CSUM_MASK;
11122         mask |= NETIF_F_VLAN_CHALLENGED;
11123
11124         all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11125         all &= one | ~NETIF_F_ALL_FOR_ALL;
11126
11127         /* If one device supports hw checksumming, set for all. */
11128         if (all & NETIF_F_HW_CSUM)
11129                 all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11130
11131         return all;
11132 }
11133 EXPORT_SYMBOL(netdev_increment_features);
11134
11135 static struct hlist_head * __net_init netdev_create_hash(void)
11136 {
11137         int i;
11138         struct hlist_head *hash;
11139
11140         hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11141         if (hash != NULL)
11142                 for (i = 0; i < NETDEV_HASHENTRIES; i++)
11143                         INIT_HLIST_HEAD(&hash[i]);
11144
11145         return hash;
11146 }
11147
11148 /* Initialize per network namespace state */
11149 static int __net_init netdev_init(struct net *net)
11150 {
11151         BUILD_BUG_ON(GRO_HASH_BUCKETS >
11152                      8 * sizeof_field(struct napi_struct, gro_bitmask));
11153
11154         INIT_LIST_HEAD(&net->dev_base_head);
11155
11156         net->dev_name_head = netdev_create_hash();
11157         if (net->dev_name_head == NULL)
11158                 goto err_name;
11159
11160         net->dev_index_head = netdev_create_hash();
11161         if (net->dev_index_head == NULL)
11162                 goto err_idx;
11163
11164         RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11165
11166         return 0;
11167
11168 err_idx:
11169         kfree(net->dev_name_head);
11170 err_name:
11171         return -ENOMEM;
11172 }
11173
11174 /**
11175  *      netdev_drivername - network driver for the device
11176  *      @dev: network device
11177  *
11178  *      Determine network driver for device.
11179  */
11180 const char *netdev_drivername(const struct net_device *dev)
11181 {
11182         const struct device_driver *driver;
11183         const struct device *parent;
11184         const char *empty = "";
11185
11186         parent = dev->dev.parent;
11187         if (!parent)
11188                 return empty;
11189
11190         driver = parent->driver;
11191         if (driver && driver->name)
11192                 return driver->name;
11193         return empty;
11194 }
11195
11196 static void __netdev_printk(const char *level, const struct net_device *dev,
11197                             struct va_format *vaf)
11198 {
11199         if (dev && dev->dev.parent) {
11200                 dev_printk_emit(level[1] - '0',
11201                                 dev->dev.parent,
11202                                 "%s %s %s%s: %pV",
11203                                 dev_driver_string(dev->dev.parent),
11204                                 dev_name(dev->dev.parent),
11205                                 netdev_name(dev), netdev_reg_state(dev),
11206                                 vaf);
11207         } else if (dev) {
11208                 printk("%s%s%s: %pV",
11209                        level, netdev_name(dev), netdev_reg_state(dev), vaf);
11210         } else {
11211                 printk("%s(NULL net_device): %pV", level, vaf);
11212         }
11213 }
11214
11215 void netdev_printk(const char *level, const struct net_device *dev,
11216                    const char *format, ...)
11217 {
11218         struct va_format vaf;
11219         va_list args;
11220
11221         va_start(args, format);
11222
11223         vaf.fmt = format;
11224         vaf.va = &args;
11225
11226         __netdev_printk(level, dev, &vaf);
11227
11228         va_end(args);
11229 }
11230 EXPORT_SYMBOL(netdev_printk);
11231
11232 #define define_netdev_printk_level(func, level)                 \
11233 void func(const struct net_device *dev, const char *fmt, ...)   \
11234 {                                                               \
11235         struct va_format vaf;                                   \
11236         va_list args;                                           \
11237                                                                 \
11238         va_start(args, fmt);                                    \
11239                                                                 \
11240         vaf.fmt = fmt;                                          \
11241         vaf.va = &args;                                         \
11242                                                                 \
11243         __netdev_printk(level, dev, &vaf);                      \
11244                                                                 \
11245         va_end(args);                                           \
11246 }                                                               \
11247 EXPORT_SYMBOL(func);
11248
11249 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11250 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11251 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11252 define_netdev_printk_level(netdev_err, KERN_ERR);
11253 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11254 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11255 define_netdev_printk_level(netdev_info, KERN_INFO);
11256
11257 static void __net_exit netdev_exit(struct net *net)
11258 {
11259         kfree(net->dev_name_head);
11260         kfree(net->dev_index_head);
11261         if (net != &init_net)
11262                 WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11263 }
11264
11265 static struct pernet_operations __net_initdata netdev_net_ops = {
11266         .init = netdev_init,
11267         .exit = netdev_exit,
11268 };
11269
11270 static void __net_exit default_device_exit_net(struct net *net)
11271 {
11272         struct net_device *dev, *aux;
11273         /*
11274          * Push all migratable network devices back to the
11275          * initial network namespace
11276          */
11277         ASSERT_RTNL();
11278         for_each_netdev_safe(net, dev, aux) {
11279                 int err;
11280                 char fb_name[IFNAMSIZ];
11281
11282                 /* Ignore unmoveable devices (i.e. loopback) */
11283                 if (dev->features & NETIF_F_NETNS_LOCAL)
11284                         continue;
11285
11286                 /* Leave virtual devices for the generic cleanup */
11287                 if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11288                         continue;
11289
11290                 /* Push remaining network devices to init_net */
11291                 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11292                 if (netdev_name_in_use(&init_net, fb_name))
11293                         snprintf(fb_name, IFNAMSIZ, "dev%%d");
11294                 err = dev_change_net_namespace(dev, &init_net, fb_name);
11295                 if (err) {
11296                         pr_emerg("%s: failed to move %s to init_net: %d\n",
11297                                  __func__, dev->name, err);
11298                         BUG();
11299                 }
11300         }
11301 }
11302
11303 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11304 {
11305         /* At exit all network devices most be removed from a network
11306          * namespace.  Do this in the reverse order of registration.
11307          * Do this across as many network namespaces as possible to
11308          * improve batching efficiency.
11309          */
11310         struct net_device *dev;
11311         struct net *net;
11312         LIST_HEAD(dev_kill_list);
11313
11314         rtnl_lock();
11315         list_for_each_entry(net, net_list, exit_list) {
11316                 default_device_exit_net(net);
11317                 cond_resched();
11318         }
11319
11320         list_for_each_entry(net, net_list, exit_list) {
11321                 for_each_netdev_reverse(net, dev) {
11322                         if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11323                                 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11324                         else
11325                                 unregister_netdevice_queue(dev, &dev_kill_list);
11326                 }
11327         }
11328         unregister_netdevice_many(&dev_kill_list);
11329         rtnl_unlock();
11330 }
11331
11332 static struct pernet_operations __net_initdata default_device_ops = {
11333         .exit_batch = default_device_exit_batch,
11334 };
11335
11336 /*
11337  *      Initialize the DEV module. At boot time this walks the device list and
11338  *      unhooks any devices that fail to initialise (normally hardware not
11339  *      present) and leaves us with a valid list of present and active devices.
11340  *
11341  */
11342
11343 /*
11344  *       This is called single threaded during boot, so no need
11345  *       to take the rtnl semaphore.
11346  */
11347 static int __init net_dev_init(void)
11348 {
11349         int i, rc = -ENOMEM;
11350
11351         BUG_ON(!dev_boot_phase);
11352
11353         if (dev_proc_init())
11354                 goto out;
11355
11356         if (netdev_kobject_init())
11357                 goto out;
11358
11359         INIT_LIST_HEAD(&ptype_all);
11360         for (i = 0; i < PTYPE_HASH_SIZE; i++)
11361                 INIT_LIST_HEAD(&ptype_base[i]);
11362
11363         if (register_pernet_subsys(&netdev_net_ops))
11364                 goto out;
11365
11366         /*
11367          *      Initialise the packet receive queues.
11368          */
11369
11370         for_each_possible_cpu(i) {
11371                 struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11372                 struct softnet_data *sd = &per_cpu(softnet_data, i);
11373
11374                 INIT_WORK(flush, flush_backlog);
11375
11376                 skb_queue_head_init(&sd->input_pkt_queue);
11377                 skb_queue_head_init(&sd->process_queue);
11378 #ifdef CONFIG_XFRM_OFFLOAD
11379                 skb_queue_head_init(&sd->xfrm_backlog);
11380 #endif
11381                 INIT_LIST_HEAD(&sd->poll_list);
11382                 sd->output_queue_tailp = &sd->output_queue;
11383 #ifdef CONFIG_RPS
11384                 INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11385                 sd->cpu = i;
11386 #endif
11387                 INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11388                 spin_lock_init(&sd->defer_lock);
11389
11390                 init_gro_hash(&sd->backlog);
11391                 sd->backlog.poll = process_backlog;
11392                 sd->backlog.weight = weight_p;
11393         }
11394
11395         dev_boot_phase = 0;
11396
11397         /* The loopback device is special if any other network devices
11398          * is present in a network namespace the loopback device must
11399          * be present. Since we now dynamically allocate and free the
11400          * loopback device ensure this invariant is maintained by
11401          * keeping the loopback device as the first device on the
11402          * list of network devices.  Ensuring the loopback devices
11403          * is the first device that appears and the last network device
11404          * that disappears.
11405          */
11406         if (register_pernet_device(&loopback_net_ops))
11407                 goto out;
11408
11409         if (register_pernet_device(&default_device_ops))
11410                 goto out;
11411
11412         open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11413         open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11414
11415         rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11416                                        NULL, dev_cpu_dead);
11417         WARN_ON(rc < 0);
11418         rc = 0;
11419 out:
11420         return rc;
11421 }
11422
11423 subsys_initcall(net_dev_init);