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