net/ipv4/ipmr.c

   1 /*
   2  *      IP multicast routing support for mrouted 3.6/3.8
   3  *
   4  *              (c) 1995 Alan Cox, <[email protected]>
   5  *        Linux Consultancy and Custom Driver Development
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  *
  12  *      Fixes:
  13  *      Michael Chastain        :       Incorrect size of copying.
  14  *      Alan Cox                :       Added the cache manager code
  15  *      Alan Cox                :       Fixed the clone/copy bug and device race.
  16  *      Mike McLagan            :       Routing by source
  17  *      Malcolm Beattie         :       Buffer handling fixes.
  18  *      Alexey Kuznetsov        :       Double buffer free and other fixes.
  19  *      SVR Anand               :       Fixed several multicast bugs and problems.
  20  *      Alexey Kuznetsov        :       Status, optimisations and more.
  21  *      Brad Parker             :       Better behaviour on mrouted upcall
  22  *                                      overflow.
  23  *      Carlos Picoto           :       PIMv1 Support
  24  *      Pavlin Ivanov Radoslavov:       PIMv2 Registers must checksum only PIM header
  25  *                                      Relax this requirement to work with older peers.
  26  *
  27  */
  28
  29 #include <linux/uaccess.h>
  30 #include <linux/types.h>
  31 #include <linux/capability.h>
  32 #include <linux/errno.h>
  33 #include <linux/timer.h>
  34 #include <linux/mm.h>
  35 #include <linux/kernel.h>
  36 #include <linux/fcntl.h>
  37 #include <linux/stat.h>
  38 #include <linux/socket.h>
  39 #include <linux/in.h>
  40 #include <linux/inet.h>
  41 #include <linux/netdevice.h>
  42 #include <linux/inetdevice.h>
  43 #include <linux/igmp.h>
  44 #include <linux/proc_fs.h>
  45 #include <linux/seq_file.h>
  46 #include <linux/mroute.h>
  47 #include <linux/init.h>
  48 #include <linux/if_ether.h>
  49 #include <linux/slab.h>
  50 #include <net/net_namespace.h>
  51 #include <net/ip.h>
  52 #include <net/protocol.h>
  53 #include <linux/skbuff.h>
  54 #include <net/route.h>
  55 #include <net/sock.h>
  56 #include <net/icmp.h>
  57 #include <net/udp.h>
  58 #include <net/raw.h>
  59 #include <linux/notifier.h>
  60 #include <linux/if_arp.h>
  61 #include <linux/netfilter_ipv4.h>
  62 #include <linux/compat.h>
  63 #include <linux/export.h>
  64 #include <net/ip_tunnels.h>
  65 #include <net/checksum.h>
  66 #include <net/netlink.h>
  67 #include <net/fib_rules.h>
  68 #include <linux/netconf.h>
  69 #include <net/nexthop.h>
  70
  71 struct ipmr_rule {
  72         struct fib_rule         common;
  73 };
  74
  75 struct ipmr_result {
  76         struct mr_table         *mrt;
  77 };
  78
  79 /* Big lock, protecting vif table, mrt cache and mroute socket state.
  80  * Note that the changes are semaphored via rtnl_lock.
  81  */
  82
  83 static DEFINE_RWLOCK(mrt_lock);
  84
  85 /* Multicast router control variables */
  86
  87 /* Special spinlock for queue of unresolved entries */
  88 static DEFINE_SPINLOCK(mfc_unres_lock);
  89
  90 /* We return to original Alan's scheme. Hash table of resolved
  91  * entries is changed only in process context and protected
  92  * with weak lock mrt_lock. Queue of unresolved entries is protected
  93  * with strong spinlock mfc_unres_lock.
  94  *
  95  * In this case data path is free of exclusive locks at all.
  96  */
  97
  98 static struct kmem_cache *mrt_cachep __read_mostly;
  99
 100 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
 101 static void ipmr_free_table(struct mr_table *mrt);
 102
 103 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
 104                           struct net_device *dev, struct sk_buff *skb,
 105                           struct mfc_cache *cache, int local);
 106 static int ipmr_cache_report(struct mr_table *mrt,
 107                              struct sk_buff *pkt, vifi_t vifi, int assert);
 108 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 109                               struct mfc_cache *c, struct rtmsg *rtm);
 110 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
 111                                  int cmd);
 112 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
 113 static void mroute_clean_tables(struct mr_table *mrt, bool all);
 114 static void ipmr_expire_process(unsigned long arg);
 115
 116 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 117 #define ipmr_for_each_table(mrt, net) \
 118         list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
 119
 120 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 121 {
 122         struct mr_table *mrt;
 123
 124         ipmr_for_each_table(mrt, net) {
 125                 if (mrt->id == id)
 126                         return mrt;
 127         }
 128         return NULL;
 129 }
 130
 131 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 132                            struct mr_table **mrt)
 133 {
 134         int err;
 135         struct ipmr_result res;
 136         struct fib_lookup_arg arg = {
 137                 .result = &res,
 138                 .flags = FIB_LOOKUP_NOREF,
 139         };
 140
 141         /* update flow if oif or iif point to device enslaved to l3mdev */
 142         l3mdev_update_flow(net, flowi4_to_flowi(flp4));
 143
 144         err = fib_rules_lookup(net->ipv4.mr_rules_ops,
 145                                flowi4_to_flowi(flp4), 0, &arg);
 146         if (err < 0)
 147                 return err;
 148         *mrt = res.mrt;
 149         return 0;
 150 }
 151
 152 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
 153                             int flags, struct fib_lookup_arg *arg)
 154 {
 155         struct ipmr_result *res = arg->result;
 156         struct mr_table *mrt;
 157
 158         switch (rule->action) {
 159         case FR_ACT_TO_TBL:
 160                 break;
 161         case FR_ACT_UNREACHABLE:
 162                 return -ENETUNREACH;
 163         case FR_ACT_PROHIBIT:
 164                 return -EACCES;
 165         case FR_ACT_BLACKHOLE:
 166         default:
 167                 return -EINVAL;
 168         }
 169
 170         arg->table = fib_rule_get_table(rule, arg);
 171
 172         mrt = ipmr_get_table(rule->fr_net, arg->table);
 173         if (!mrt)
 174                 return -EAGAIN;
 175         res->mrt = mrt;
 176         return 0;
 177 }
 178
 179 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 180 {
 181         return 1;
 182 }
 183
 184 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
 185         FRA_GENERIC_POLICY,
 186 };
 187
 188 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
 189                                struct fib_rule_hdr *frh, struct nlattr **tb)
 190 {
 191         return 0;
 192 }
 193
 194 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
 195                              struct nlattr **tb)
 196 {
 197         return 1;
 198 }
 199
 200 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 201                           struct fib_rule_hdr *frh)
 202 {
 203         frh->dst_len = 0;
 204         frh->src_len = 0;
 205         frh->tos     = 0;
 206         return 0;
 207 }
 208
 209 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
 210         .family         = RTNL_FAMILY_IPMR,
 211         .rule_size      = sizeof(struct ipmr_rule),
 212         .addr_size      = sizeof(u32),
 213         .action         = ipmr_rule_action,
 214         .match          = ipmr_rule_match,
 215         .configure      = ipmr_rule_configure,
 216         .compare        = ipmr_rule_compare,
 217         .fill           = ipmr_rule_fill,
 218         .nlgroup        = RTNLGRP_IPV4_RULE,
 219         .policy         = ipmr_rule_policy,
 220         .owner          = THIS_MODULE,
 221 };
 222
 223 static int __net_init ipmr_rules_init(struct net *net)
 224 {
 225         struct fib_rules_ops *ops;
 226         struct mr_table *mrt;
 227         int err;
 228
 229         ops = fib_rules_register(&ipmr_rules_ops_template, net);
 230         if (IS_ERR(ops))
 231                 return PTR_ERR(ops);
 232
 233         INIT_LIST_HEAD(&net->ipv4.mr_tables);
 234
 235         mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 236         if (IS_ERR(mrt)) {
 237                 err = PTR_ERR(mrt);
 238                 goto err1;
 239         }
 240
 241         err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
 242         if (err < 0)
 243                 goto err2;
 244
 245         net->ipv4.mr_rules_ops = ops;
 246         return 0;
 247
 248 err2:
 249         ipmr_free_table(mrt);
 250 err1:
 251         fib_rules_unregister(ops);
 252         return err;
 253 }
 254
 255 static void __net_exit ipmr_rules_exit(struct net *net)
 256 {
 257         struct mr_table *mrt, *next;
 258
 259         rtnl_lock();
 260         list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
 261                 list_del(&mrt->list);
 262                 ipmr_free_table(mrt);
 263         }
 264         fib_rules_unregister(net->ipv4.mr_rules_ops);
 265         rtnl_unlock();
 266 }
 267 #else
 268 #define ipmr_for_each_table(mrt, net) \
 269         for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
 270
 271 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 272 {
 273         return net->ipv4.mrt;
 274 }
 275
 276 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 277                            struct mr_table **mrt)
 278 {
 279         *mrt = net->ipv4.mrt;
 280         return 0;
 281 }
 282
 283 static int __net_init ipmr_rules_init(struct net *net)
 284 {
 285         struct mr_table *mrt;
 286
 287         mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 288         if (IS_ERR(mrt))
 289                 return PTR_ERR(mrt);
 290         net->ipv4.mrt = mrt;
 291         return 0;
 292 }
 293
 294 static void __net_exit ipmr_rules_exit(struct net *net)
 295 {
 296         rtnl_lock();
 297         ipmr_free_table(net->ipv4.mrt);
 298         net->ipv4.mrt = NULL;
 299         rtnl_unlock();
 300 }
 301 #endif
 302
 303 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
 304                                 const void *ptr)
 305 {
 306         const struct mfc_cache_cmp_arg *cmparg = arg->key;
 307         struct mfc_cache *c = (struct mfc_cache *)ptr;
 308
 309         return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
 310                cmparg->mfc_origin != c->mfc_origin;
 311 }
 312
 313 static const struct rhashtable_params ipmr_rht_params = {
 314         .head_offset = offsetof(struct mfc_cache, mnode),
 315         .key_offset = offsetof(struct mfc_cache, cmparg),
 316         .key_len = sizeof(struct mfc_cache_cmp_arg),
 317         .nelem_hint = 3,
 318         .locks_mul = 1,
 319         .obj_cmpfn = ipmr_hash_cmp,
 320         .automatic_shrinking = true,
 321 };
 322
 323 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 324 {
 325         struct mr_table *mrt;
 326
 327         /* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
 328         if (id != RT_TABLE_DEFAULT && id >= 1000000000)
 329                 return ERR_PTR(-EINVAL);
 330
 331         mrt = ipmr_get_table(net, id);
 332         if (mrt)
 333                 return mrt;
 334
 335         mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
 336         if (!mrt)
 337                 return ERR_PTR(-ENOMEM);
 338         write_pnet(&mrt->net, net);
 339         mrt->id = id;
 340
 341         rhltable_init(&mrt->mfc_hash, &ipmr_rht_params);
 342         INIT_LIST_HEAD(&mrt->mfc_cache_list);
 343         INIT_LIST_HEAD(&mrt->mfc_unres_queue);
 344
 345         setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
 346                     (unsigned long)mrt);
 347
 348         mrt->mroute_reg_vif_num = -1;
 349 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 350         list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
 351 #endif
 352         return mrt;
 353 }
 354
 355 static void ipmr_free_table(struct mr_table *mrt)
 356 {
 357         del_timer_sync(&mrt->ipmr_expire_timer);
 358         mroute_clean_tables(mrt, true);
 359         rhltable_destroy(&mrt->mfc_hash);
 360         kfree(mrt);
 361 }
 362
 363 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
 364
 365 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
 366 {
 367         struct net *net = dev_net(dev);
 368
 369         dev_close(dev);
 370
 371         dev = __dev_get_by_name(net, "tunl0");
 372         if (dev) {
 373                 const struct net_device_ops *ops = dev->netdev_ops;
 374                 struct ifreq ifr;
 375                 struct ip_tunnel_parm p;
 376
 377                 memset(&p, 0, sizeof(p));
 378                 p.iph.daddr = v->vifc_rmt_addr.s_addr;
 379                 p.iph.saddr = v->vifc_lcl_addr.s_addr;
 380                 p.iph.version = 4;
 381                 p.iph.ihl = 5;
 382                 p.iph.protocol = IPPROTO_IPIP;
 383                 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 384                 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 385
 386                 if (ops->ndo_do_ioctl) {
 387                         mm_segment_t oldfs = get_fs();
 388
 389                         set_fs(KERNEL_DS);
 390                         ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
 391                         set_fs(oldfs);
 392                 }
 393         }
 394 }
 395
 396 /* Initialize ipmr pimreg/tunnel in_device */
 397 static bool ipmr_init_vif_indev(const struct net_device *dev)
 398 {
 399         struct in_device *in_dev;
 400
 401         ASSERT_RTNL();
 402
 403         in_dev = __in_dev_get_rtnl(dev);
 404         if (!in_dev)
 405                 return false;
 406         ipv4_devconf_setall(in_dev);
 407         neigh_parms_data_state_setall(in_dev->arp_parms);
 408         IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 409
 410         return true;
 411 }
 412
 413 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
 414 {
 415         struct net_device  *dev;
 416
 417         dev = __dev_get_by_name(net, "tunl0");
 418
 419         if (dev) {
 420                 const struct net_device_ops *ops = dev->netdev_ops;
 421                 int err;
 422                 struct ifreq ifr;
 423                 struct ip_tunnel_parm p;
 424
 425                 memset(&p, 0, sizeof(p));
 426                 p.iph.daddr = v->vifc_rmt_addr.s_addr;
 427                 p.iph.saddr = v->vifc_lcl_addr.s_addr;
 428                 p.iph.version = 4;
 429                 p.iph.ihl = 5;
 430                 p.iph.protocol = IPPROTO_IPIP;
 431                 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 432                 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 433
 434                 if (ops->ndo_do_ioctl) {
 435                         mm_segment_t oldfs = get_fs();
 436
 437                         set_fs(KERNEL_DS);
 438                         err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
 439                         set_fs(oldfs);
 440                 } else {
 441                         err = -EOPNOTSUPP;
 442                 }
 443                 dev = NULL;
 444
 445                 if (err == 0 &&
 446                     (dev = __dev_get_by_name(net, p.name)) != NULL) {
 447                         dev->flags |= IFF_MULTICAST;
 448                         if (!ipmr_init_vif_indev(dev))
 449                                 goto failure;
 450                         if (dev_open(dev))
 451                                 goto failure;
 452                         dev_hold(dev);
 453                 }
 454         }
 455         return dev;
 456
 457 failure:
 458         unregister_netdevice(dev);
 459         return NULL;
 460 }
 461
 462 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
 463 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
 464 {
 465         struct net *net = dev_net(dev);
 466         struct mr_table *mrt;
 467         struct flowi4 fl4 = {
 468                 .flowi4_oif     = dev->ifindex,
 469                 .flowi4_iif     = skb->skb_iif ? : LOOPBACK_IFINDEX,
 470                 .flowi4_mark    = skb->mark,
 471         };
 472         int err;
 473
 474         err = ipmr_fib_lookup(net, &fl4, &mrt);
 475         if (err < 0) {
 476                 kfree_skb(skb);
 477                 return err;
 478         }
 479
 480         read_lock(&mrt_lock);
 481         dev->stats.tx_bytes += skb->len;
 482         dev->stats.tx_packets++;
 483         ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
 484         read_unlock(&mrt_lock);
 485         kfree_skb(skb);
 486         return NETDEV_TX_OK;
 487 }
 488
 489 static int reg_vif_get_iflink(const struct net_device *dev)
 490 {
 491         return 0;
 492 }
 493
 494 static const struct net_device_ops reg_vif_netdev_ops = {
 495         .ndo_start_xmit = reg_vif_xmit,
 496         .ndo_get_iflink = reg_vif_get_iflink,
 497 };
 498
 499 static void reg_vif_setup(struct net_device *dev)
 500 {
 501         dev->type               = ARPHRD_PIMREG;
 502         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
 503         dev->flags              = IFF_NOARP;
 504         dev->netdev_ops         = &reg_vif_netdev_ops;
 505         dev->needs_free_netdev  = true;
 506         dev->features           |= NETIF_F_NETNS_LOCAL;
 507 }
 508
 509 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 510 {
 511         struct net_device *dev;
 512         char name[IFNAMSIZ];
 513
 514         if (mrt->id == RT_TABLE_DEFAULT)
 515                 sprintf(name, "pimreg");
 516         else
 517                 sprintf(name, "pimreg%u", mrt->id);
 518
 519         dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
 520
 521         if (!dev)
 522                 return NULL;
 523
 524         dev_net_set(dev, net);
 525
 526         if (register_netdevice(dev)) {
 527                 free_netdev(dev);
 528                 return NULL;
 529         }
 530
 531         if (!ipmr_init_vif_indev(dev))
 532                 goto failure;
 533         if (dev_open(dev))
 534                 goto failure;
 535
 536         dev_hold(dev);
 537
 538         return dev;
 539
 540 failure:
 541         unregister_netdevice(dev);
 542         return NULL;
 543 }
 544
 545 /* called with rcu_read_lock() */
 546 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
 547                      unsigned int pimlen)
 548 {
 549         struct net_device *reg_dev = NULL;
 550         struct iphdr *encap;
 551
 552         encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
 553         /* Check that:
 554          * a. packet is really sent to a multicast group
 555          * b. packet is not a NULL-REGISTER
 556          * c. packet is not truncated
 557          */
 558         if (!ipv4_is_multicast(encap->daddr) ||
 559             encap->tot_len == 0 ||
 560             ntohs(encap->tot_len) + pimlen > skb->len)
 561                 return 1;
 562
 563         read_lock(&mrt_lock);
 564         if (mrt->mroute_reg_vif_num >= 0)
 565                 reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
 566         read_unlock(&mrt_lock);
 567
 568         if (!reg_dev)
 569                 return 1;
 570
 571         skb->mac_header = skb->network_header;
 572         skb_pull(skb, (u8 *)encap - skb->data);
 573         skb_reset_network_header(skb);
 574         skb->protocol = htons(ETH_P_IP);
 575         skb->ip_summed = CHECKSUM_NONE;
 576
 577         skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
 578
 579         netif_rx(skb);
 580
 581         return NET_RX_SUCCESS;
 582 }
 583 #else
 584 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 585 {
 586         return NULL;
 587 }
 588 #endif
 589
 590 /**
 591  *      vif_delete - Delete a VIF entry
 592  *      @notify: Set to 1, if the caller is a notifier_call
 593  */
 594 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
 595                       struct list_head *head)
 596 {
 597         struct vif_device *v;
 598         struct net_device *dev;
 599         struct in_device *in_dev;
 600
 601         if (vifi < 0 || vifi >= mrt->maxvif)
 602                 return -EADDRNOTAVAIL;
 603
 604         v = &mrt->vif_table[vifi];
 605
 606         write_lock_bh(&mrt_lock);
 607         dev = v->dev;
 608         v->dev = NULL;
 609
 610         if (!dev) {
 611                 write_unlock_bh(&mrt_lock);
 612                 return -EADDRNOTAVAIL;
 613         }
 614
 615         if (vifi == mrt->mroute_reg_vif_num)
 616                 mrt->mroute_reg_vif_num = -1;
 617
 618         if (vifi + 1 == mrt->maxvif) {
 619                 int tmp;
 620
 621                 for (tmp = vifi - 1; tmp >= 0; tmp--) {
 622                         if (VIF_EXISTS(mrt, tmp))
 623                                 break;
 624                 }
 625                 mrt->maxvif = tmp+1;
 626         }
 627
 628         write_unlock_bh(&mrt_lock);
 629
 630         dev_set_allmulti(dev, -1);
 631
 632         in_dev = __in_dev_get_rtnl(dev);
 633         if (in_dev) {
 634                 IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
 635                 inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
 636                                             NETCONFA_MC_FORWARDING,
 637                                             dev->ifindex, &in_dev->cnf);
 638                 ip_rt_multicast_event(in_dev);
 639         }
 640
 641         if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
 642                 unregister_netdevice_queue(dev, head);
 643
 644         dev_put(dev);
 645         return 0;
 646 }
 647
 648 static void ipmr_cache_free_rcu(struct rcu_head *head)
 649 {
 650         struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
 651
 652         kmem_cache_free(mrt_cachep, c);
 653 }
 654
 655 static inline void ipmr_cache_free(struct mfc_cache *c)
 656 {
 657         call_rcu(&c->rcu, ipmr_cache_free_rcu);
 658 }
 659
 660 /* Destroy an unresolved cache entry, killing queued skbs
 661  * and reporting error to netlink readers.
 662  */
 663 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
 664 {
 665         struct net *net = read_pnet(&mrt->net);
 666         struct sk_buff *skb;
 667         struct nlmsgerr *e;
 668
 669         atomic_dec(&mrt->cache_resolve_queue_len);
 670
 671         while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
 672                 if (ip_hdr(skb)->version == 0) {
 673                         struct nlmsghdr *nlh = skb_pull(skb,
 674                                                         sizeof(struct iphdr));
 675                         nlh->nlmsg_type = NLMSG_ERROR;
 676                         nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
 677                         skb_trim(skb, nlh->nlmsg_len);
 678                         e = nlmsg_data(nlh);
 679                         e->error = -ETIMEDOUT;
 680                         memset(&e->msg, 0, sizeof(e->msg));
 681
 682                         rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
 683                 } else {
 684                         kfree_skb(skb);
 685                 }
 686         }
 687
 688         ipmr_cache_free(c);
 689 }
 690
 691 /* Timer process for the unresolved queue. */
 692 static void ipmr_expire_process(unsigned long arg)
 693 {
 694         struct mr_table *mrt = (struct mr_table *)arg;
 695         unsigned long now;
 696         unsigned long expires;
 697         struct mfc_cache *c, *next;
 698
 699         if (!spin_trylock(&mfc_unres_lock)) {
 700                 mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
 701                 return;
 702         }
 703
 704         if (list_empty(&mrt->mfc_unres_queue))
 705                 goto out;
 706
 707         now = jiffies;
 708         expires = 10*HZ;
 709
 710         list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
 711                 if (time_after(c->mfc_un.unres.expires, now)) {
 712                         unsigned long interval = c->mfc_un.unres.expires - now;
 713                         if (interval < expires)
 714                                 expires = interval;
 715                         continue;
 716                 }
 717
 718                 list_del(&c->list);
 719                 mroute_netlink_event(mrt, c, RTM_DELROUTE);
 720                 ipmr_destroy_unres(mrt, c);
 721         }
 722
 723         if (!list_empty(&mrt->mfc_unres_queue))
 724                 mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
 725
 726 out:
 727         spin_unlock(&mfc_unres_lock);
 728 }
 729
 730 /* Fill oifs list. It is called under write locked mrt_lock. */
 731 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
 732                                    unsigned char *ttls)
 733 {
 734         int vifi;
 735
 736         cache->mfc_un.res.minvif = MAXVIFS;
 737         cache->mfc_un.res.maxvif = 0;
 738         memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
 739
 740         for (vifi = 0; vifi < mrt->maxvif; vifi++) {
 741                 if (VIF_EXISTS(mrt, vifi) &&
 742                     ttls[vifi] && ttls[vifi] < 255) {
 743                         cache->mfc_un.res.ttls[vifi] = ttls[vifi];
 744                         if (cache->mfc_un.res.minvif > vifi)
 745                                 cache->mfc_un.res.minvif = vifi;
 746                         if (cache->mfc_un.res.maxvif <= vifi)
 747                                 cache->mfc_un.res.maxvif = vifi + 1;
 748                 }
 749         }
 750         cache->mfc_un.res.lastuse = jiffies;
 751 }
 752
 753 static int vif_add(struct net *net, struct mr_table *mrt,
 754                    struct vifctl *vifc, int mrtsock)
 755 {
 756         int vifi = vifc->vifc_vifi;
 757         struct vif_device *v = &mrt->vif_table[vifi];
 758         struct net_device *dev;
 759         struct in_device *in_dev;
 760         int err;
 761
 762         /* Is vif busy ? */
 763         if (VIF_EXISTS(mrt, vifi))
 764                 return -EADDRINUSE;
 765
 766         switch (vifc->vifc_flags) {
 767         case VIFF_REGISTER:
 768                 if (!ipmr_pimsm_enabled())
 769                         return -EINVAL;
 770                 /* Special Purpose VIF in PIM
 771                  * All the packets will be sent to the daemon
 772                  */
 773                 if (mrt->mroute_reg_vif_num >= 0)
 774                         return -EADDRINUSE;
 775                 dev = ipmr_reg_vif(net, mrt);
 776                 if (!dev)
 777                         return -ENOBUFS;
 778                 err = dev_set_allmulti(dev, 1);
 779                 if (err) {
 780                         unregister_netdevice(dev);
 781                         dev_put(dev);
 782                         return err;
 783                 }
 784                 break;
 785         case VIFF_TUNNEL:
 786                 dev = ipmr_new_tunnel(net, vifc);
 787                 if (!dev)
 788                         return -ENOBUFS;
 789                 err = dev_set_allmulti(dev, 1);
 790                 if (err) {
 791                         ipmr_del_tunnel(dev, vifc);
 792                         dev_put(dev);
 793                         return err;
 794                 }
 795                 break;
 796         case VIFF_USE_IFINDEX:
 797         case 0:
 798                 if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
 799                         dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
 800                         if (dev && !__in_dev_get_rtnl(dev)) {
 801                                 dev_put(dev);
 802                                 return -EADDRNOTAVAIL;
 803                         }
 804                 } else {
 805                         dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
 806                 }
 807                 if (!dev)
 808                         return -EADDRNOTAVAIL;
 809                 err = dev_set_allmulti(dev, 1);
 810                 if (err) {
 811                         dev_put(dev);
 812                         return err;
 813                 }
 814                 break;
 815         default:
 816                 return -EINVAL;
 817         }
 818
 819         in_dev = __in_dev_get_rtnl(dev);
 820         if (!in_dev) {
 821                 dev_put(dev);
 822                 return -EADDRNOTAVAIL;
 823         }
 824         IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
 825         inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
 826                                     dev->ifindex, &in_dev->cnf);
 827         ip_rt_multicast_event(in_dev);
 828
 829         /* Fill in the VIF structures */
 830
 831         v->rate_limit = vifc->vifc_rate_limit;
 832         v->local = vifc->vifc_lcl_addr.s_addr;
 833         v->remote = vifc->vifc_rmt_addr.s_addr;
 834         v->flags = vifc->vifc_flags;
 835         if (!mrtsock)
 836                 v->flags |= VIFF_STATIC;
 837         v->threshold = vifc->vifc_threshold;
 838         v->bytes_in = 0;
 839         v->bytes_out = 0;
 840         v->pkt_in = 0;
 841         v->pkt_out = 0;
 842         v->link = dev->ifindex;
 843         if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
 844                 v->link = dev_get_iflink(dev);
 845
 846         /* And finish update writing critical data */
 847         write_lock_bh(&mrt_lock);
 848         v->dev = dev;
 849         if (v->flags & VIFF_REGISTER)
 850                 mrt->mroute_reg_vif_num = vifi;
 851         if (vifi+1 > mrt->maxvif)
 852                 mrt->maxvif = vifi+1;
 853         write_unlock_bh(&mrt_lock);
 854         return 0;
 855 }
 856
 857 /* called with rcu_read_lock() */
 858 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
 859                                          __be32 origin,
 860                                          __be32 mcastgrp)
 861 {
 862         struct mfc_cache_cmp_arg arg = {
 863                         .mfc_mcastgrp = mcastgrp,
 864                         .mfc_origin = origin
 865         };
 866         struct rhlist_head *tmp, *list;
 867         struct mfc_cache *c;
 868
 869         list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
 870         rhl_for_each_entry_rcu(c, tmp, list, mnode)
 871                 return c;
 872
 873         return NULL;
 874 }
 875
 876 /* Look for a (*,*,oif) entry */
 877 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
 878                                                     int vifi)
 879 {
 880         struct mfc_cache_cmp_arg arg = {
 881                         .mfc_mcastgrp = htonl(INADDR_ANY),
 882                         .mfc_origin = htonl(INADDR_ANY)
 883         };
 884         struct rhlist_head *tmp, *list;
 885         struct mfc_cache *c;
 886
 887         list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
 888         rhl_for_each_entry_rcu(c, tmp, list, mnode)
 889                 if (c->mfc_un.res.ttls[vifi] < 255)
 890                         return c;
 891
 892         return NULL;
 893 }
 894
 895 /* Look for a (*,G) entry */
 896 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
 897                                              __be32 mcastgrp, int vifi)
 898 {
 899         struct mfc_cache_cmp_arg arg = {
 900                         .mfc_mcastgrp = mcastgrp,
 901                         .mfc_origin = htonl(INADDR_ANY)
 902         };
 903         struct rhlist_head *tmp, *list;
 904         struct mfc_cache *c, *proxy;
 905
 906         if (mcastgrp == htonl(INADDR_ANY))
 907                 goto skip;
 908
 909         list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
 910         rhl_for_each_entry_rcu(c, tmp, list, mnode) {
 911                 if (c->mfc_un.res.ttls[vifi] < 255)
 912                         return c;
 913
 914                 /* It's ok if the vifi is part of the static tree */
 915                 proxy = ipmr_cache_find_any_parent(mrt, c->mfc_parent);
 916                 if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
 917                         return c;
 918         }
 919
 920 skip:
 921         return ipmr_cache_find_any_parent(mrt, vifi);
 922 }
 923
 924 /* Look for a (S,G,iif) entry if parent != -1 */
 925 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
 926                                                 __be32 origin, __be32 mcastgrp,
 927                                                 int parent)
 928 {
 929         struct mfc_cache_cmp_arg arg = {
 930                         .mfc_mcastgrp = mcastgrp,
 931                         .mfc_origin = origin,
 932         };
 933         struct rhlist_head *tmp, *list;
 934         struct mfc_cache *c;
 935
 936         list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
 937         rhl_for_each_entry_rcu(c, tmp, list, mnode)
 938                 if (parent == -1 || parent == c->mfc_parent)
 939                         return c;
 940
 941         return NULL;
 942 }
 943
 944 /* Allocate a multicast cache entry */
 945 static struct mfc_cache *ipmr_cache_alloc(void)
 946 {
 947         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
 948
 949         if (c) {
 950                 c->mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
 951                 c->mfc_un.res.minvif = MAXVIFS;
 952         }
 953         return c;
 954 }
 955
 956 static struct mfc_cache *ipmr_cache_alloc_unres(void)
 957 {
 958         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
 959
 960         if (c) {
 961                 skb_queue_head_init(&c->mfc_un.unres.unresolved);
 962                 c->mfc_un.unres.expires = jiffies + 10*HZ;
 963         }
 964         return c;
 965 }
 966
 967 /* A cache entry has gone into a resolved state from queued */
 968 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
 969                                struct mfc_cache *uc, struct mfc_cache *c)
 970 {
 971         struct sk_buff *skb;
 972         struct nlmsgerr *e;
 973
 974         /* Play the pending entries through our router */
 975         while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
 976                 if (ip_hdr(skb)->version == 0) {
 977                         struct nlmsghdr *nlh = skb_pull(skb,
 978                                                         sizeof(struct iphdr));
 979
 980                         if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
 981                                 nlh->nlmsg_len = skb_tail_pointer(skb) -
 982                                                  (u8 *)nlh;
 983                         } else {
 984                                 nlh->nlmsg_type = NLMSG_ERROR;
 985                                 nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
 986                                 skb_trim(skb, nlh->nlmsg_len);
 987                                 e = nlmsg_data(nlh);
 988                                 e->error = -EMSGSIZE;
 989                                 memset(&e->msg, 0, sizeof(e->msg));
 990                         }
 991
 992                         rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
 993                 } else {
 994                         ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
 995                 }
 996         }
 997 }
 998
 999 /* Bounce a cache query up to mrouted and netlink.
1000  *
1001  * Called under mrt_lock.
1002  */
1003 static int ipmr_cache_report(struct mr_table *mrt,
1004                              struct sk_buff *pkt, vifi_t vifi, int assert)
1005 {
1006         const int ihl = ip_hdrlen(pkt);
1007         struct sock *mroute_sk;
1008         struct igmphdr *igmp;
1009         struct igmpmsg *msg;
1010         struct sk_buff *skb;
1011         int ret;
1012
1013         if (assert == IGMPMSG_WHOLEPKT)
1014                 skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1015         else
1016                 skb = alloc_skb(128, GFP_ATOMIC);
1017
1018         if (!skb)
1019                 return -ENOBUFS;
1020
1021         if (assert == IGMPMSG_WHOLEPKT) {
1022                 /* Ugly, but we have no choice with this interface.
1023                  * Duplicate old header, fix ihl, length etc.
1024                  * And all this only to mangle msg->im_msgtype and
1025                  * to set msg->im_mbz to "mbz" :-)
1026                  */
1027                 skb_push(skb, sizeof(struct iphdr));
1028                 skb_reset_network_header(skb);
1029                 skb_reset_transport_header(skb);
1030                 msg = (struct igmpmsg *)skb_network_header(skb);
1031                 memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1032                 msg->im_msgtype = IGMPMSG_WHOLEPKT;
1033                 msg->im_mbz = 0;
1034                 msg->im_vif = mrt->mroute_reg_vif_num;
1035                 ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1036                 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1037                                              sizeof(struct iphdr));
1038         } else {
1039                 /* Copy the IP header */
1040                 skb_set_network_header(skb, skb->len);
1041                 skb_put(skb, ihl);
1042                 skb_copy_to_linear_data(skb, pkt->data, ihl);
1043                 /* Flag to the kernel this is a route add */
1044                 ip_hdr(skb)->protocol = 0;
1045                 msg = (struct igmpmsg *)skb_network_header(skb);
1046                 msg->im_vif = vifi;
1047                 skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1048                 /* Add our header */
1049                 igmp = skb_put(skb, sizeof(struct igmphdr));
1050                 igmp->type = assert;
1051                 msg->im_msgtype = assert;
1052                 igmp->code = 0;
1053                 ip_hdr(skb)->tot_len = htons(skb->len); /* Fix the length */
1054                 skb->transport_header = skb->network_header;
1055         }
1056
1057         rcu_read_lock();
1058         mroute_sk = rcu_dereference(mrt->mroute_sk);
1059         if (!mroute_sk) {
1060                 rcu_read_unlock();
1061                 kfree_skb(skb);
1062                 return -EINVAL;
1063         }
1064
1065         igmpmsg_netlink_event(mrt, skb);
1066
1067         /* Deliver to mrouted */
1068         ret = sock_queue_rcv_skb(mroute_sk, skb);
1069         rcu_read_unlock();
1070         if (ret < 0) {
1071                 net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1072                 kfree_skb(skb);
1073         }
1074
1075         return ret;
1076 }
1077
1078 /* Queue a packet for resolution. It gets locked cache entry! */
1079 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1080                                  struct sk_buff *skb, struct net_device *dev)
1081 {
1082         const struct iphdr *iph = ip_hdr(skb);
1083         struct mfc_cache *c;
1084         bool found = false;
1085         int err;
1086
1087         spin_lock_bh(&mfc_unres_lock);
1088         list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1089                 if (c->mfc_mcastgrp == iph->daddr &&
1090                     c->mfc_origin == iph->saddr) {
1091                         found = true;
1092                         break;
1093                 }
1094         }
1095
1096         if (!found) {
1097                 /* Create a new entry if allowable */
1098                 if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1099                     (c = ipmr_cache_alloc_unres()) == NULL) {
1100                         spin_unlock_bh(&mfc_unres_lock);
1101
1102                         kfree_skb(skb);
1103                         return -ENOBUFS;
1104                 }
1105
1106                 /* Fill in the new cache entry */
1107                 c->mfc_parent   = -1;
1108                 c->mfc_origin   = iph->saddr;
1109                 c->mfc_mcastgrp = iph->daddr;
1110
1111                 /* Reflect first query at mrouted. */
1112                 err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1113                 if (err < 0) {
1114                         /* If the report failed throw the cache entry
1115                            out - Brad Parker
1116                          */
1117                         spin_unlock_bh(&mfc_unres_lock);
1118
1119                         ipmr_cache_free(c);
1120                         kfree_skb(skb);
1121                         return err;
1122                 }
1123
1124                 atomic_inc(&mrt->cache_resolve_queue_len);
1125                 list_add(&c->list, &mrt->mfc_unres_queue);
1126                 mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1127
1128                 if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1129                         mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1130         }
1131
1132         /* See if we can append the packet */
1133         if (c->mfc_un.unres.unresolved.qlen > 3) {
1134                 kfree_skb(skb);
1135                 err = -ENOBUFS;
1136         } else {
1137                 if (dev) {
1138                         skb->dev = dev;
1139                         skb->skb_iif = dev->ifindex;
1140                 }
1141                 skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1142                 err = 0;
1143         }
1144
1145         spin_unlock_bh(&mfc_unres_lock);
1146         return err;
1147 }
1148
1149 /* MFC cache manipulation by user space mroute daemon */
1150
1151 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1152 {
1153         struct mfc_cache *c;
1154
1155         /* The entries are added/deleted only under RTNL */
1156         rcu_read_lock();
1157         c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1158                                    mfc->mfcc_mcastgrp.s_addr, parent);
1159         rcu_read_unlock();
1160         if (!c)
1161                 return -ENOENT;
1162         rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1163         list_del_rcu(&c->list);
1164         mroute_netlink_event(mrt, c, RTM_DELROUTE);
1165         ipmr_cache_free(c);
1166
1167         return 0;
1168 }
1169
1170 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1171                         struct mfcctl *mfc, int mrtsock, int parent)
1172 {
1173         struct mfc_cache *uc, *c;
1174         bool found;
1175         int ret;
1176
1177         if (mfc->mfcc_parent >= MAXVIFS)
1178                 return -ENFILE;
1179
1180         /* The entries are added/deleted only under RTNL */
1181         rcu_read_lock();
1182         c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1183                                    mfc->mfcc_mcastgrp.s_addr, parent);
1184         rcu_read_unlock();
1185         if (c) {
1186                 write_lock_bh(&mrt_lock);
1187                 c->mfc_parent = mfc->mfcc_parent;
1188                 ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1189                 if (!mrtsock)
1190                         c->mfc_flags |= MFC_STATIC;
1191                 write_unlock_bh(&mrt_lock);
1192                 mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1193                 return 0;
1194         }
1195
1196         if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1197             !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1198                 return -EINVAL;
1199
1200         c = ipmr_cache_alloc();
1201         if (!c)
1202                 return -ENOMEM;
1203
1204         c->mfc_origin = mfc->mfcc_origin.s_addr;
1205         c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1206         c->mfc_parent = mfc->mfcc_parent;
1207         ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1208         if (!mrtsock)
1209                 c->mfc_flags |= MFC_STATIC;
1210
1211         ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->mnode,
1212                                   ipmr_rht_params);
1213         if (ret) {
1214                 pr_err("ipmr: rhtable insert error %d\n", ret);
1215                 ipmr_cache_free(c);
1216                 return ret;
1217         }
1218         list_add_tail_rcu(&c->list, &mrt->mfc_cache_list);
1219         /* Check to see if we resolved a queued list. If so we
1220          * need to send on the frames and tidy up.
1221          */
1222         found = false;
1223         spin_lock_bh(&mfc_unres_lock);
1224         list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1225                 if (uc->mfc_origin == c->mfc_origin &&
1226                     uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1227                         list_del(&uc->list);
1228                         atomic_dec(&mrt->cache_resolve_queue_len);
1229                         found = true;
1230                         break;
1231                 }
1232         }
1233         if (list_empty(&mrt->mfc_unres_queue))
1234                 del_timer(&mrt->ipmr_expire_timer);
1235         spin_unlock_bh(&mfc_unres_lock);
1236
1237         if (found) {
1238                 ipmr_cache_resolve(net, mrt, uc, c);
1239                 ipmr_cache_free(uc);
1240         }
1241         mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1242         return 0;
1243 }
1244
1245 /* Close the multicast socket, and clear the vif tables etc */
1246 static void mroute_clean_tables(struct mr_table *mrt, bool all)
1247 {
1248         struct mfc_cache *c, *tmp;
1249         LIST_HEAD(list);
1250         int i;
1251
1252         /* Shut down all active vif entries */
1253         for (i = 0; i < mrt->maxvif; i++) {
1254                 if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
1255                         continue;
1256                 vif_delete(mrt, i, 0, &list);
1257         }
1258         unregister_netdevice_many(&list);
1259
1260         /* Wipe the cache */
1261         list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1262                 if (!all && (c->mfc_flags & MFC_STATIC))
1263                         continue;
1264                 rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1265                 list_del_rcu(&c->list);
1266                 mroute_netlink_event(mrt, c, RTM_DELROUTE);
1267                 ipmr_cache_free(c);
1268         }
1269
1270         if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1271                 spin_lock_bh(&mfc_unres_lock);
1272                 list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1273                         list_del(&c->list);
1274                         mroute_netlink_event(mrt, c, RTM_DELROUTE);
1275                         ipmr_destroy_unres(mrt, c);
1276                 }
1277                 spin_unlock_bh(&mfc_unres_lock);
1278         }
1279 }
1280
1281 /* called from ip_ra_control(), before an RCU grace period,
1282  * we dont need to call synchronize_rcu() here
1283  */
1284 static void mrtsock_destruct(struct sock *sk)
1285 {
1286         struct net *net = sock_net(sk);
1287         struct mr_table *mrt;
1288
1289         ASSERT_RTNL();
1290         ipmr_for_each_table(mrt, net) {
1291                 if (sk == rtnl_dereference(mrt->mroute_sk)) {
1292                         IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1293                         inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1294                                                     NETCONFA_MC_FORWARDING,
1295                                                     NETCONFA_IFINDEX_ALL,
1296                                                     net->ipv4.devconf_all);
1297                         RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1298                         mroute_clean_tables(mrt, false);
1299                 }
1300         }
1301 }
1302
1303 /* Socket options and virtual interface manipulation. The whole
1304  * virtual interface system is a complete heap, but unfortunately
1305  * that's how BSD mrouted happens to think. Maybe one day with a proper
1306  * MOSPF/PIM router set up we can clean this up.
1307  */
1308
1309 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
1310                          unsigned int optlen)
1311 {
1312         struct net *net = sock_net(sk);
1313         int val, ret = 0, parent = 0;
1314         struct mr_table *mrt;
1315         struct vifctl vif;
1316         struct mfcctl mfc;
1317         u32 uval;
1318
1319         /* There's one exception to the lock - MRT_DONE which needs to unlock */
1320         rtnl_lock();
1321         if (sk->sk_type != SOCK_RAW ||
1322             inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1323                 ret = -EOPNOTSUPP;
1324                 goto out_unlock;
1325         }
1326
1327         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1328         if (!mrt) {
1329                 ret = -ENOENT;
1330                 goto out_unlock;
1331         }
1332         if (optname != MRT_INIT) {
1333                 if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1334                     !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1335                         ret = -EACCES;
1336                         goto out_unlock;
1337                 }
1338         }
1339
1340         switch (optname) {
1341         case MRT_INIT:
1342                 if (optlen != sizeof(int)) {
1343                         ret = -EINVAL;
1344                         break;
1345                 }
1346                 if (rtnl_dereference(mrt->mroute_sk)) {
1347                         ret = -EADDRINUSE;
1348                         break;
1349                 }
1350
1351                 ret = ip_ra_control(sk, 1, mrtsock_destruct);
1352                 if (ret == 0) {
1353                         rcu_assign_pointer(mrt->mroute_sk, sk);
1354                         IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1355                         inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1356                                                     NETCONFA_MC_FORWARDING,
1357                                                     NETCONFA_IFINDEX_ALL,
1358                                                     net->ipv4.devconf_all);
1359                 }
1360                 break;
1361         case MRT_DONE:
1362                 if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1363                         ret = -EACCES;
1364                 } else {
1365                         ret = ip_ra_control(sk, 0, NULL);
1366                         goto out_unlock;
1367                 }
1368                 break;
1369         case MRT_ADD_VIF:
1370         case MRT_DEL_VIF:
1371                 if (optlen != sizeof(vif)) {
1372                         ret = -EINVAL;
1373                         break;
1374                 }
1375                 if (copy_from_user(&vif, optval, sizeof(vif))) {
1376                         ret = -EFAULT;
1377                         break;
1378                 }
1379                 if (vif.vifc_vifi >= MAXVIFS) {
1380                         ret = -ENFILE;
1381                         break;
1382                 }
1383                 if (optname == MRT_ADD_VIF) {
1384                         ret = vif_add(net, mrt, &vif,
1385                                       sk == rtnl_dereference(mrt->mroute_sk));
1386                 } else {
1387                         ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1388                 }
1389                 break;
1390         /* Manipulate the forwarding caches. These live
1391          * in a sort of kernel/user symbiosis.
1392          */
1393         case MRT_ADD_MFC:
1394         case MRT_DEL_MFC:
1395                 parent = -1;
1396         case MRT_ADD_MFC_PROXY:
1397         case MRT_DEL_MFC_PROXY:
1398                 if (optlen != sizeof(mfc)) {
1399                         ret = -EINVAL;
1400                         break;
1401                 }
1402                 if (copy_from_user(&mfc, optval, sizeof(mfc))) {
1403                         ret = -EFAULT;
1404                         break;
1405                 }
1406                 if (parent == 0)
1407                         parent = mfc.mfcc_parent;
1408                 if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1409                         ret = ipmr_mfc_delete(mrt, &mfc, parent);
1410                 else
1411                         ret = ipmr_mfc_add(net, mrt, &mfc,
1412                                            sk == rtnl_dereference(mrt->mroute_sk),
1413                                            parent);
1414                 break;
1415         /* Control PIM assert. */
1416         case MRT_ASSERT:
1417                 if (optlen != sizeof(val)) {
1418                         ret = -EINVAL;
1419                         break;
1420                 }
1421                 if (get_user(val, (int __user *)optval)) {
1422                         ret = -EFAULT;
1423                         break;
1424                 }
1425                 mrt->mroute_do_assert = val;
1426                 break;
1427         case MRT_PIM:
1428                 if (!ipmr_pimsm_enabled()) {
1429                         ret = -ENOPROTOOPT;
1430                         break;
1431                 }
1432                 if (optlen != sizeof(val)) {
1433                         ret = -EINVAL;
1434                         break;
1435                 }
1436                 if (get_user(val, (int __user *)optval)) {
1437                         ret = -EFAULT;
1438                         break;
1439                 }
1440
1441                 val = !!val;
1442                 if (val != mrt->mroute_do_pim) {
1443                         mrt->mroute_do_pim = val;
1444                         mrt->mroute_do_assert = val;
1445                 }
1446                 break;
1447         case MRT_TABLE:
1448                 if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1449                         ret = -ENOPROTOOPT;
1450                         break;
1451                 }
1452                 if (optlen != sizeof(uval)) {
1453                         ret = -EINVAL;
1454                         break;
1455                 }
1456                 if (get_user(uval, (u32 __user *)optval)) {
1457                         ret = -EFAULT;
1458                         break;
1459                 }
1460
1461                 if (sk == rtnl_dereference(mrt->mroute_sk)) {
1462                         ret = -EBUSY;
1463                 } else {
1464                         mrt = ipmr_new_table(net, uval);
1465                         if (IS_ERR(mrt))
1466                                 ret = PTR_ERR(mrt);
1467                         else
1468                                 raw_sk(sk)->ipmr_table = uval;
1469                 }
1470                 break;
1471         /* Spurious command, or MRT_VERSION which you cannot set. */
1472         default:
1473                 ret = -ENOPROTOOPT;
1474         }
1475 out_unlock:
1476         rtnl_unlock();
1477         return ret;
1478 }
1479
1480 /* Getsock opt support for the multicast routing system. */
1481 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1482 {
1483         int olr;
1484         int val;
1485         struct net *net = sock_net(sk);
1486         struct mr_table *mrt;
1487
1488         if (sk->sk_type != SOCK_RAW ||
1489             inet_sk(sk)->inet_num != IPPROTO_IGMP)
1490                 return -EOPNOTSUPP;
1491
1492         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1493         if (!mrt)
1494                 return -ENOENT;
1495
1496         switch (optname) {
1497         case MRT_VERSION:
1498                 val = 0x0305;
1499                 break;
1500         case MRT_PIM:
1501                 if (!ipmr_pimsm_enabled())
1502                         return -ENOPROTOOPT;
1503                 val = mrt->mroute_do_pim;
1504                 break;
1505         case MRT_ASSERT:
1506                 val = mrt->mroute_do_assert;
1507                 break;
1508         default:
1509                 return -ENOPROTOOPT;
1510         }
1511
1512         if (get_user(olr, optlen))
1513                 return -EFAULT;
1514         olr = min_t(unsigned int, olr, sizeof(int));
1515         if (olr < 0)
1516                 return -EINVAL;
1517         if (put_user(olr, optlen))
1518                 return -EFAULT;
1519         if (copy_to_user(optval, &val, olr))
1520                 return -EFAULT;
1521         return 0;
1522 }
1523
1524 /* The IP multicast ioctl support routines. */
1525 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1526 {
1527         struct sioc_sg_req sr;
1528         struct sioc_vif_req vr;
1529         struct vif_device *vif;
1530         struct mfc_cache *c;
1531         struct net *net = sock_net(sk);
1532         struct mr_table *mrt;
1533
1534         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1535         if (!mrt)
1536                 return -ENOENT;
1537
1538         switch (cmd) {
1539         case SIOCGETVIFCNT:
1540                 if (copy_from_user(&vr, arg, sizeof(vr)))
1541                         return -EFAULT;
1542                 if (vr.vifi >= mrt->maxvif)
1543                         return -EINVAL;
1544                 read_lock(&mrt_lock);
1545                 vif = &mrt->vif_table[vr.vifi];
1546                 if (VIF_EXISTS(mrt, vr.vifi)) {
1547                         vr.icount = vif->pkt_in;
1548                         vr.ocount = vif->pkt_out;
1549                         vr.ibytes = vif->bytes_in;
1550                         vr.obytes = vif->bytes_out;
1551                         read_unlock(&mrt_lock);
1552
1553                         if (copy_to_user(arg, &vr, sizeof(vr)))
1554                                 return -EFAULT;
1555                         return 0;
1556                 }
1557                 read_unlock(&mrt_lock);
1558                 return -EADDRNOTAVAIL;
1559         case SIOCGETSGCNT:
1560                 if (copy_from_user(&sr, arg, sizeof(sr)))
1561                         return -EFAULT;
1562
1563                 rcu_read_lock();
1564                 c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1565                 if (c) {
1566                         sr.pktcnt = c->mfc_un.res.pkt;
1567                         sr.bytecnt = c->mfc_un.res.bytes;
1568                         sr.wrong_if = c->mfc_un.res.wrong_if;
1569                         rcu_read_unlock();
1570
1571                         if (copy_to_user(arg, &sr, sizeof(sr)))
1572                                 return -EFAULT;
1573                         return 0;
1574                 }
1575                 rcu_read_unlock();
1576                 return -EADDRNOTAVAIL;
1577         default:
1578                 return -ENOIOCTLCMD;
1579         }
1580 }
1581
1582 #ifdef CONFIG_COMPAT
1583 struct compat_sioc_sg_req {
1584         struct in_addr src;
1585         struct in_addr grp;
1586         compat_ulong_t pktcnt;
1587         compat_ulong_t bytecnt;
1588         compat_ulong_t wrong_if;
1589 };
1590
1591 struct compat_sioc_vif_req {
1592         vifi_t  vifi;           /* Which iface */
1593         compat_ulong_t icount;
1594         compat_ulong_t ocount;
1595         compat_ulong_t ibytes;
1596         compat_ulong_t obytes;
1597 };
1598
1599 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1600 {
1601         struct compat_sioc_sg_req sr;
1602         struct compat_sioc_vif_req vr;
1603         struct vif_device *vif;
1604         struct mfc_cache *c;
1605         struct net *net = sock_net(sk);
1606         struct mr_table *mrt;
1607
1608         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1609         if (!mrt)
1610                 return -ENOENT;
1611
1612         switch (cmd) {
1613         case SIOCGETVIFCNT:
1614                 if (copy_from_user(&vr, arg, sizeof(vr)))
1615                         return -EFAULT;
1616                 if (vr.vifi >= mrt->maxvif)
1617                         return -EINVAL;
1618                 read_lock(&mrt_lock);
1619                 vif = &mrt->vif_table[vr.vifi];
1620                 if (VIF_EXISTS(mrt, vr.vifi)) {
1621                         vr.icount = vif->pkt_in;
1622                         vr.ocount = vif->pkt_out;
1623                         vr.ibytes = vif->bytes_in;
1624                         vr.obytes = vif->bytes_out;
1625                         read_unlock(&mrt_lock);
1626
1627                         if (copy_to_user(arg, &vr, sizeof(vr)))
1628                                 return -EFAULT;
1629                         return 0;
1630                 }
1631                 read_unlock(&mrt_lock);
1632                 return -EADDRNOTAVAIL;
1633         case SIOCGETSGCNT:
1634                 if (copy_from_user(&sr, arg, sizeof(sr)))
1635                         return -EFAULT;
1636
1637                 rcu_read_lock();
1638                 c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1639                 if (c) {
1640                         sr.pktcnt = c->mfc_un.res.pkt;
1641                         sr.bytecnt = c->mfc_un.res.bytes;
1642                         sr.wrong_if = c->mfc_un.res.wrong_if;
1643                         rcu_read_unlock();
1644
1645                         if (copy_to_user(arg, &sr, sizeof(sr)))
1646                                 return -EFAULT;
1647                         return 0;
1648                 }
1649                 rcu_read_unlock();
1650                 return -EADDRNOTAVAIL;
1651         default:
1652                 return -ENOIOCTLCMD;
1653         }
1654 }
1655 #endif
1656
1657 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1658 {
1659         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1660         struct net *net = dev_net(dev);
1661         struct mr_table *mrt;
1662         struct vif_device *v;
1663         int ct;
1664
1665         if (event != NETDEV_UNREGISTER)
1666                 return NOTIFY_DONE;
1667
1668         ipmr_for_each_table(mrt, net) {
1669                 v = &mrt->vif_table[0];
1670                 for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1671                         if (v->dev == dev)
1672                                 vif_delete(mrt, ct, 1, NULL);
1673                 }
1674         }
1675         return NOTIFY_DONE;
1676 }
1677
1678 static struct notifier_block ip_mr_notifier = {
1679         .notifier_call = ipmr_device_event,
1680 };
1681
1682 /* Encapsulate a packet by attaching a valid IPIP header to it.
1683  * This avoids tunnel drivers and other mess and gives us the speed so
1684  * important for multicast video.
1685  */
1686 static void ip_encap(struct net *net, struct sk_buff *skb,
1687                      __be32 saddr, __be32 daddr)
1688 {
1689         struct iphdr *iph;
1690         const struct iphdr *old_iph = ip_hdr(skb);
1691
1692         skb_push(skb, sizeof(struct iphdr));
1693         skb->transport_header = skb->network_header;
1694         skb_reset_network_header(skb);
1695         iph = ip_hdr(skb);
1696
1697         iph->version    =       4;
1698         iph->tos        =       old_iph->tos;
1699         iph->ttl        =       old_iph->ttl;
1700         iph->frag_off   =       0;
1701         iph->daddr      =       daddr;
1702         iph->saddr      =       saddr;
1703         iph->protocol   =       IPPROTO_IPIP;
1704         iph->ihl        =       5;
1705         iph->tot_len    =       htons(skb->len);
1706         ip_select_ident(net, skb, NULL);
1707         ip_send_check(iph);
1708
1709         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1710         nf_reset(skb);
1711 }
1712
1713 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1714                                       struct sk_buff *skb)
1715 {
1716         struct ip_options *opt = &(IPCB(skb)->opt);
1717
1718         IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1719         IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1720
1721         if (unlikely(opt->optlen))
1722                 ip_forward_options(skb);
1723
1724         return dst_output(net, sk, skb);
1725 }
1726
1727 /* Processing handlers for ipmr_forward */
1728
1729 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1730                             struct sk_buff *skb, struct mfc_cache *c, int vifi)
1731 {
1732         const struct iphdr *iph = ip_hdr(skb);
1733         struct vif_device *vif = &mrt->vif_table[vifi];
1734         struct net_device *dev;
1735         struct rtable *rt;
1736         struct flowi4 fl4;
1737         int    encap = 0;
1738
1739         if (!vif->dev)
1740                 goto out_free;
1741
1742         if (vif->flags & VIFF_REGISTER) {
1743                 vif->pkt_out++;
1744                 vif->bytes_out += skb->len;
1745                 vif->dev->stats.tx_bytes += skb->len;
1746                 vif->dev->stats.tx_packets++;
1747                 ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1748                 goto out_free;
1749         }
1750
1751         if (vif->flags & VIFF_TUNNEL) {
1752                 rt = ip_route_output_ports(net, &fl4, NULL,
1753                                            vif->remote, vif->local,
1754                                            0, 0,
1755                                            IPPROTO_IPIP,
1756                                            RT_TOS(iph->tos), vif->link);
1757                 if (IS_ERR(rt))
1758                         goto out_free;
1759                 encap = sizeof(struct iphdr);
1760         } else {
1761                 rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1762                                            0, 0,
1763                                            IPPROTO_IPIP,
1764                                            RT_TOS(iph->tos), vif->link);
1765                 if (IS_ERR(rt))
1766                         goto out_free;
1767         }
1768
1769         dev = rt->dst.dev;
1770
1771         if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1772                 /* Do not fragment multicasts. Alas, IPv4 does not
1773                  * allow to send ICMP, so that packets will disappear
1774                  * to blackhole.
1775                  */
1776                 IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1777                 ip_rt_put(rt);
1778                 goto out_free;
1779         }
1780
1781         encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1782
1783         if (skb_cow(skb, encap)) {
1784                 ip_rt_put(rt);
1785                 goto out_free;
1786         }
1787
1788         vif->pkt_out++;
1789         vif->bytes_out += skb->len;
1790
1791         skb_dst_drop(skb);
1792         skb_dst_set(skb, &rt->dst);
1793         ip_decrease_ttl(ip_hdr(skb));
1794
1795         /* FIXME: forward and output firewalls used to be called here.
1796          * What do we do with netfilter? -- RR
1797          */
1798         if (vif->flags & VIFF_TUNNEL) {
1799                 ip_encap(net, skb, vif->local, vif->remote);
1800                 /* FIXME: extra output firewall step used to be here. --RR */
1801                 vif->dev->stats.tx_packets++;
1802                 vif->dev->stats.tx_bytes += skb->len;
1803         }
1804
1805         IPCB(skb)->flags |= IPSKB_FORWARDED;
1806
1807         /* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1808          * not only before forwarding, but after forwarding on all output
1809          * interfaces. It is clear, if mrouter runs a multicasting
1810          * program, it should receive packets not depending to what interface
1811          * program is joined.
1812          * If we will not make it, the program will have to join on all
1813          * interfaces. On the other hand, multihoming host (or router, but
1814          * not mrouter) cannot join to more than one interface - it will
1815          * result in receiving multiple packets.
1816          */
1817         NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1818                 net, NULL, skb, skb->dev, dev,
1819                 ipmr_forward_finish);
1820         return;
1821
1822 out_free:
1823         kfree_skb(skb);
1824 }
1825
1826 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1827 {
1828         int ct;
1829
1830         for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1831                 if (mrt->vif_table[ct].dev == dev)
1832                         break;
1833         }
1834         return ct;
1835 }
1836
1837 /* "local" means that we should preserve one skb (for local delivery) */
1838 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1839                           struct net_device *dev, struct sk_buff *skb,
1840                           struct mfc_cache *cache, int local)
1841 {
1842         int true_vifi = ipmr_find_vif(mrt, dev);
1843         int psend = -1;
1844         int vif, ct;
1845
1846         vif = cache->mfc_parent;
1847         cache->mfc_un.res.pkt++;
1848         cache->mfc_un.res.bytes += skb->len;
1849         cache->mfc_un.res.lastuse = jiffies;
1850
1851         if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1852                 struct mfc_cache *cache_proxy;
1853
1854                 /* For an (*,G) entry, we only check that the incomming
1855                  * interface is part of the static tree.
1856                  */
1857                 cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1858                 if (cache_proxy &&
1859                     cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1860                         goto forward;
1861         }
1862
1863         /* Wrong interface: drop packet and (maybe) send PIM assert. */
1864         if (mrt->vif_table[vif].dev != dev) {
1865                 if (rt_is_output_route(skb_rtable(skb))) {
1866                         /* It is our own packet, looped back.
1867                          * Very complicated situation...
1868                          *
1869                          * The best workaround until routing daemons will be
1870                          * fixed is not to redistribute packet, if it was
1871                          * send through wrong interface. It means, that
1872                          * multicast applications WILL NOT work for
1873                          * (S,G), which have default multicast route pointing
1874                          * to wrong oif. In any case, it is not a good
1875                          * idea to use multicasting applications on router.
1876                          */
1877                         goto dont_forward;
1878                 }
1879
1880                 cache->mfc_un.res.wrong_if++;
1881
1882                 if (true_vifi >= 0 && mrt->mroute_do_assert &&
1883                     /* pimsm uses asserts, when switching from RPT to SPT,
1884                      * so that we cannot check that packet arrived on an oif.
1885                      * It is bad, but otherwise we would need to move pretty
1886                      * large chunk of pimd to kernel. Ough... --ANK
1887                      */
1888                     (mrt->mroute_do_pim ||
1889                      cache->mfc_un.res.ttls[true_vifi] < 255) &&
1890                     time_after(jiffies,
1891                                cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1892                         cache->mfc_un.res.last_assert = jiffies;
1893                         ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1894                 }
1895                 goto dont_forward;
1896         }
1897
1898 forward:
1899         mrt->vif_table[vif].pkt_in++;
1900         mrt->vif_table[vif].bytes_in += skb->len;
1901
1902         /* Forward the frame */
1903         if (cache->mfc_origin == htonl(INADDR_ANY) &&
1904             cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1905                 if (true_vifi >= 0 &&
1906                     true_vifi != cache->mfc_parent &&
1907                     ip_hdr(skb)->ttl >
1908                                 cache->mfc_un.res.ttls[cache->mfc_parent]) {
1909                         /* It's an (*,*) entry and the packet is not coming from
1910                          * the upstream: forward the packet to the upstream
1911                          * only.
1912                          */
1913                         psend = cache->mfc_parent;
1914                         goto last_forward;
1915                 }
1916                 goto dont_forward;
1917         }
1918         for (ct = cache->mfc_un.res.maxvif - 1;
1919              ct >= cache->mfc_un.res.minvif; ct--) {
1920                 /* For (*,G) entry, don't forward to the incoming interface */
1921                 if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1922                      ct != true_vifi) &&
1923                     ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1924                         if (psend != -1) {
1925                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1926
1927                                 if (skb2)
1928                                         ipmr_queue_xmit(net, mrt, skb2, cache,
1929                                                         psend);
1930                         }
1931                         psend = ct;
1932                 }
1933         }
1934 last_forward:
1935         if (psend != -1) {
1936                 if (local) {
1937                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1938
1939                         if (skb2)
1940                                 ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1941                 } else {
1942                         ipmr_queue_xmit(net, mrt, skb, cache, psend);
1943                         return;
1944                 }
1945         }
1946
1947 dont_forward:
1948         if (!local)
1949                 kfree_skb(skb);
1950 }
1951
1952 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1953 {
1954         struct rtable *rt = skb_rtable(skb);
1955         struct iphdr *iph = ip_hdr(skb);
1956         struct flowi4 fl4 = {
1957                 .daddr = iph->daddr,
1958                 .saddr = iph->saddr,
1959                 .flowi4_tos = RT_TOS(iph->tos),
1960                 .flowi4_oif = (rt_is_output_route(rt) ?
1961                                skb->dev->ifindex : 0),
1962                 .flowi4_iif = (rt_is_output_route(rt) ?
1963                                LOOPBACK_IFINDEX :
1964                                skb->dev->ifindex),
1965                 .flowi4_mark = skb->mark,
1966         };
1967         struct mr_table *mrt;
1968         int err;
1969
1970         err = ipmr_fib_lookup(net, &fl4, &mrt);
1971         if (err)
1972                 return ERR_PTR(err);
1973         return mrt;
1974 }
1975
1976 /* Multicast packets for forwarding arrive here
1977  * Called with rcu_read_lock();
1978  */
1979 int ip_mr_input(struct sk_buff *skb)
1980 {
1981         struct mfc_cache *cache;
1982         struct net *net = dev_net(skb->dev);
1983         int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1984         struct mr_table *mrt;
1985         struct net_device *dev;
1986
1987         /* skb->dev passed in is the loX master dev for vrfs.
1988          * As there are no vifs associated with loopback devices,
1989          * get the proper interface that does have a vif associated with it.
1990          */
1991         dev = skb->dev;
1992         if (netif_is_l3_master(skb->dev)) {
1993                 dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
1994                 if (!dev) {
1995                         kfree_skb(skb);
1996                         return -ENODEV;
1997                 }
1998         }
1999
2000         /* Packet is looped back after forward, it should not be
2001          * forwarded second time, but still can be delivered locally.
2002          */
2003         if (IPCB(skb)->flags & IPSKB_FORWARDED)
2004                 goto dont_forward;
2005
2006         mrt = ipmr_rt_fib_lookup(net, skb);
2007         if (IS_ERR(mrt)) {
2008                 kfree_skb(skb);
2009                 return PTR_ERR(mrt);
2010         }
2011         if (!local) {
2012                 if (IPCB(skb)->opt.router_alert) {
2013                         if (ip_call_ra_chain(skb))
2014                                 return 0;
2015                 } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2016                         /* IGMPv1 (and broken IGMPv2 implementations sort of
2017                          * Cisco IOS <= 11.2(8)) do not put router alert
2018                          * option to IGMP packets destined to routable
2019                          * groups. It is very bad, because it means
2020                          * that we can forward NO IGMP messages.
2021                          */
2022                         struct sock *mroute_sk;
2023
2024                         mroute_sk = rcu_dereference(mrt->mroute_sk);
2025                         if (mroute_sk) {
2026                                 nf_reset(skb);
2027                                 raw_rcv(mroute_sk, skb);
2028                                 return 0;
2029                         }
2030                     }
2031         }
2032
2033         /* already under rcu_read_lock() */
2034         cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2035         if (!cache) {
2036                 int vif = ipmr_find_vif(mrt, dev);
2037
2038                 if (vif >= 0)
2039                         cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2040                                                     vif);
2041         }
2042
2043         /* No usable cache entry */
2044         if (!cache) {
2045                 int vif;
2046
2047                 if (local) {
2048                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2049                         ip_local_deliver(skb);
2050                         if (!skb2)
2051                                 return -ENOBUFS;
2052                         skb = skb2;
2053                 }
2054
2055                 read_lock(&mrt_lock);
2056                 vif = ipmr_find_vif(mrt, dev);
2057                 if (vif >= 0) {
2058                         int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev);
2059                         read_unlock(&mrt_lock);
2060
2061                         return err2;
2062                 }
2063                 read_unlock(&mrt_lock);
2064                 kfree_skb(skb);
2065                 return -ENODEV;
2066         }
2067
2068         read_lock(&mrt_lock);
2069         ip_mr_forward(net, mrt, dev, skb, cache, local);
2070         read_unlock(&mrt_lock);
2071
2072         if (local)
2073                 return ip_local_deliver(skb);
2074
2075         return 0;
2076
2077 dont_forward:
2078         if (local)
2079                 return ip_local_deliver(skb);
2080         kfree_skb(skb);
2081         return 0;
2082 }
2083
2084 #ifdef CONFIG_IP_PIMSM_V1
2085 /* Handle IGMP messages of PIMv1 */
2086 int pim_rcv_v1(struct sk_buff *skb)
2087 {
2088         struct igmphdr *pim;
2089         struct net *net = dev_net(skb->dev);
2090         struct mr_table *mrt;
2091
2092         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2093                 goto drop;
2094
2095         pim = igmp_hdr(skb);
2096
2097         mrt = ipmr_rt_fib_lookup(net, skb);
2098         if (IS_ERR(mrt))
2099                 goto drop;
2100         if (!mrt->mroute_do_pim ||
2101             pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2102                 goto drop;
2103
2104         if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2105 drop:
2106                 kfree_skb(skb);
2107         }
2108         return 0;
2109 }
2110 #endif
2111
2112 #ifdef CONFIG_IP_PIMSM_V2
2113 static int pim_rcv(struct sk_buff *skb)
2114 {
2115         struct pimreghdr *pim;
2116         struct net *net = dev_net(skb->dev);
2117         struct mr_table *mrt;
2118
2119         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2120                 goto drop;
2121
2122         pim = (struct pimreghdr *)skb_transport_header(skb);
2123         if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2124             (pim->flags & PIM_NULL_REGISTER) ||
2125             (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2126              csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2127                 goto drop;
2128
2129         mrt = ipmr_rt_fib_lookup(net, skb);
2130         if (IS_ERR(mrt))
2131                 goto drop;
2132         if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2133 drop:
2134                 kfree_skb(skb);
2135         }
2136         return 0;
2137 }
2138 #endif
2139
2140 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2141                               struct mfc_cache *c, struct rtmsg *rtm)
2142 {
2143         struct rta_mfc_stats mfcs;
2144         struct nlattr *mp_attr;
2145         struct rtnexthop *nhp;
2146         unsigned long lastuse;
2147         int ct;
2148
2149         /* If cache is unresolved, don't try to parse IIF and OIF */
2150         if (c->mfc_parent >= MAXVIFS) {
2151                 rtm->rtm_flags |= RTNH_F_UNRESOLVED;
2152                 return -ENOENT;
2153         }
2154
2155         if (VIF_EXISTS(mrt, c->mfc_parent) &&
2156             nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2157                 return -EMSGSIZE;
2158
2159         if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2160                 return -EMSGSIZE;
2161
2162         for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2163                 if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2164                         if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2165                                 nla_nest_cancel(skb, mp_attr);
2166                                 return -EMSGSIZE;
2167                         }
2168
2169                         nhp->rtnh_flags = 0;
2170                         nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2171                         nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2172                         nhp->rtnh_len = sizeof(*nhp);
2173                 }
2174         }
2175
2176         nla_nest_end(skb, mp_attr);
2177
2178         lastuse = READ_ONCE(c->mfc_un.res.lastuse);
2179         lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
2180
2181         mfcs.mfcs_packets = c->mfc_un.res.pkt;
2182         mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2183         mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2184         if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
2185             nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
2186                               RTA_PAD))
2187                 return -EMSGSIZE;
2188
2189         rtm->rtm_type = RTN_MULTICAST;
2190         return 1;
2191 }
2192
2193 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2194                    __be32 saddr, __be32 daddr,
2195                    struct rtmsg *rtm, u32 portid)
2196 {
2197         struct mfc_cache *cache;
2198         struct mr_table *mrt;
2199         int err;
2200
2201         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2202         if (!mrt)
2203                 return -ENOENT;
2204
2205         rcu_read_lock();
2206         cache = ipmr_cache_find(mrt, saddr, daddr);
2207         if (!cache && skb->dev) {
2208                 int vif = ipmr_find_vif(mrt, skb->dev);
2209
2210                 if (vif >= 0)
2211                         cache = ipmr_cache_find_any(mrt, daddr, vif);
2212         }
2213         if (!cache) {
2214                 struct sk_buff *skb2;
2215                 struct iphdr *iph;
2216                 struct net_device *dev;
2217                 int vif = -1;
2218
2219                 dev = skb->dev;
2220                 read_lock(&mrt_lock);
2221                 if (dev)
2222                         vif = ipmr_find_vif(mrt, dev);
2223                 if (vif < 0) {
2224                         read_unlock(&mrt_lock);
2225                         rcu_read_unlock();
2226                         return -ENODEV;
2227                 }
2228                 skb2 = skb_clone(skb, GFP_ATOMIC);
2229                 if (!skb2) {
2230                         read_unlock(&mrt_lock);
2231                         rcu_read_unlock();
2232                         return -ENOMEM;
2233                 }
2234
2235                 NETLINK_CB(skb2).portid = portid;
2236                 skb_push(skb2, sizeof(struct iphdr));
2237                 skb_reset_network_header(skb2);
2238                 iph = ip_hdr(skb2);
2239                 iph->ihl = sizeof(struct iphdr) >> 2;
2240                 iph->saddr = saddr;
2241                 iph->daddr = daddr;
2242                 iph->version = 0;
2243                 err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2244                 read_unlock(&mrt_lock);
2245                 rcu_read_unlock();
2246                 return err;
2247         }
2248
2249         read_lock(&mrt_lock);
2250         err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2251         read_unlock(&mrt_lock);
2252         rcu_read_unlock();
2253         return err;
2254 }
2255
2256 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2257                             u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2258                             int flags)
2259 {
2260         struct nlmsghdr *nlh;
2261         struct rtmsg *rtm;
2262         int err;
2263
2264         nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2265         if (!nlh)
2266                 return -EMSGSIZE;
2267
2268         rtm = nlmsg_data(nlh);
2269         rtm->rtm_family   = RTNL_FAMILY_IPMR;
2270         rtm->rtm_dst_len  = 32;
2271         rtm->rtm_src_len  = 32;
2272         rtm->rtm_tos      = 0;
2273         rtm->rtm_table    = mrt->id;
2274         if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2275                 goto nla_put_failure;
2276         rtm->rtm_type     = RTN_MULTICAST;
2277         rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2278         if (c->mfc_flags & MFC_STATIC)
2279                 rtm->rtm_protocol = RTPROT_STATIC;
2280         else
2281                 rtm->rtm_protocol = RTPROT_MROUTED;
2282         rtm->rtm_flags    = 0;
2283
2284         if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2285             nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2286                 goto nla_put_failure;
2287         err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2288         /* do not break the dump if cache is unresolved */
2289         if (err < 0 && err != -ENOENT)
2290                 goto nla_put_failure;
2291
2292         nlmsg_end(skb, nlh);
2293         return 0;
2294
2295 nla_put_failure:
2296         nlmsg_cancel(skb, nlh);
2297         return -EMSGSIZE;
2298 }
2299
2300 static size_t mroute_msgsize(bool unresolved, int maxvif)
2301 {
2302         size_t len =
2303                 NLMSG_ALIGN(sizeof(struct rtmsg))
2304                 + nla_total_size(4)     /* RTA_TABLE */
2305                 + nla_total_size(4)     /* RTA_SRC */
2306                 + nla_total_size(4)     /* RTA_DST */
2307                 ;
2308
2309         if (!unresolved)
2310                 len = len
2311                       + nla_total_size(4)       /* RTA_IIF */
2312                       + nla_total_size(0)       /* RTA_MULTIPATH */
2313                       + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2314                                                 /* RTA_MFC_STATS */
2315                       + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2316                 ;
2317
2318         return len;
2319 }
2320
2321 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2322                                  int cmd)
2323 {
2324         struct net *net = read_pnet(&mrt->net);
2325         struct sk_buff *skb;
2326         int err = -ENOBUFS;
2327
2328         skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2329                         GFP_ATOMIC);
2330         if (!skb)
2331                 goto errout;
2332
2333         err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2334         if (err < 0)
2335                 goto errout;
2336
2337         rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2338         return;
2339
2340 errout:
2341         kfree_skb(skb);
2342         if (err < 0)
2343                 rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2344 }
2345
2346 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2347 {
2348         size_t len =
2349                 NLMSG_ALIGN(sizeof(struct rtgenmsg))
2350                 + nla_total_size(1)     /* IPMRA_CREPORT_MSGTYPE */
2351                 + nla_total_size(4)     /* IPMRA_CREPORT_VIF_ID */
2352                 + nla_total_size(4)     /* IPMRA_CREPORT_SRC_ADDR */
2353                 + nla_total_size(4)     /* IPMRA_CREPORT_DST_ADDR */
2354                                         /* IPMRA_CREPORT_PKT */
2355                 + nla_total_size(payloadlen)
2356                 ;
2357
2358         return len;
2359 }
2360
2361 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2362 {
2363         struct net *net = read_pnet(&mrt->net);
2364         struct nlmsghdr *nlh;
2365         struct rtgenmsg *rtgenm;
2366         struct igmpmsg *msg;
2367         struct sk_buff *skb;
2368         struct nlattr *nla;
2369         int payloadlen;
2370
2371         payloadlen = pkt->len - sizeof(struct igmpmsg);
2372         msg = (struct igmpmsg *)skb_network_header(pkt);
2373
2374         skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2375         if (!skb)
2376                 goto errout;
2377
2378         nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2379                         sizeof(struct rtgenmsg), 0);
2380         if (!nlh)
2381                 goto errout;
2382         rtgenm = nlmsg_data(nlh);
2383         rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2384         if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2385             nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif) ||
2386             nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2387                             msg->im_src.s_addr) ||
2388             nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2389                             msg->im_dst.s_addr))
2390                 goto nla_put_failure;
2391
2392         nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2393         if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2394                                   nla_data(nla), payloadlen))
2395                 goto nla_put_failure;
2396
2397         nlmsg_end(skb, nlh);
2398
2399         rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2400         return;
2401
2402 nla_put_failure:
2403         nlmsg_cancel(skb, nlh);
2404 errout:
2405         kfree_skb(skb);
2406         rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2407 }
2408
2409 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2410                              struct netlink_ext_ack *extack)
2411 {
2412         struct net *net = sock_net(in_skb->sk);
2413         struct nlattr *tb[RTA_MAX + 1];
2414         struct sk_buff *skb = NULL;
2415         struct mfc_cache *cache;
2416         struct mr_table *mrt;
2417         struct rtmsg *rtm;
2418         __be32 src, grp;
2419         u32 tableid;
2420         int err;
2421
2422         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
2423                           rtm_ipv4_policy, extack);
2424         if (err < 0)
2425                 goto errout;
2426
2427         rtm = nlmsg_data(nlh);
2428
2429         src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2430         grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2431         tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2432
2433         mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2434         if (IS_ERR(mrt)) {
2435                 err = PTR_ERR(mrt);
2436                 goto errout_free;
2437         }
2438
2439         /* entries are added/deleted only under RTNL */
2440         rcu_read_lock();
2441         cache = ipmr_cache_find(mrt, src, grp);
2442         rcu_read_unlock();
2443         if (!cache) {
2444                 err = -ENOENT;
2445                 goto errout_free;
2446         }
2447
2448         skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2449         if (!skb) {
2450                 err = -ENOBUFS;
2451                 goto errout_free;
2452         }
2453
2454         err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2455                                nlh->nlmsg_seq, cache,
2456                                RTM_NEWROUTE, 0);
2457         if (err < 0)
2458                 goto errout_free;
2459
2460         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2461
2462 errout:
2463         return err;
2464
2465 errout_free:
2466         kfree_skb(skb);
2467         goto errout;
2468 }
2469
2470 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2471 {
2472         struct net *net = sock_net(skb->sk);
2473         struct mr_table *mrt;
2474         struct mfc_cache *mfc;
2475         unsigned int t = 0, s_t;
2476         unsigned int e = 0, s_e;
2477
2478         s_t = cb->args[0];
2479         s_e = cb->args[1];
2480
2481         rcu_read_lock();
2482         ipmr_for_each_table(mrt, net) {
2483                 if (t < s_t)
2484                         goto next_table;
2485                 list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
2486                         if (e < s_e)
2487                                 goto next_entry;
2488                         if (ipmr_fill_mroute(mrt, skb,
2489                                              NETLINK_CB(cb->skb).portid,
2490                                              cb->nlh->nlmsg_seq,
2491                                              mfc, RTM_NEWROUTE,
2492                                              NLM_F_MULTI) < 0)
2493                                 goto done;
2494 next_entry:
2495                         e++;
2496                 }
2497                 e = 0;
2498                 s_e = 0;
2499
2500                 spin_lock_bh(&mfc_unres_lock);
2501                 list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2502                         if (e < s_e)
2503                                 goto next_entry2;
2504                         if (ipmr_fill_mroute(mrt, skb,
2505                                              NETLINK_CB(cb->skb).portid,
2506                                              cb->nlh->nlmsg_seq,
2507                                              mfc, RTM_NEWROUTE,
2508                                              NLM_F_MULTI) < 0) {
2509                                 spin_unlock_bh(&mfc_unres_lock);
2510                                 goto done;
2511                         }
2512 next_entry2:
2513                         e++;
2514                 }
2515                 spin_unlock_bh(&mfc_unres_lock);
2516                 e = 0;
2517                 s_e = 0;
2518 next_table:
2519                 t++;
2520         }
2521 done:
2522         rcu_read_unlock();
2523
2524         cb->args[1] = e;
2525         cb->args[0] = t;
2526
2527         return skb->len;
2528 }
2529
2530 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2531         [RTA_SRC]       = { .type = NLA_U32 },
2532         [RTA_DST]       = { .type = NLA_U32 },
2533         [RTA_IIF]       = { .type = NLA_U32 },
2534         [RTA_TABLE]     = { .type = NLA_U32 },
2535         [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
2536 };
2537
2538 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2539 {
2540         switch (rtm_protocol) {
2541         case RTPROT_STATIC:
2542         case RTPROT_MROUTED:
2543                 return true;
2544         }
2545         return false;
2546 }
2547
2548 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2549 {
2550         struct rtnexthop *rtnh = nla_data(nla);
2551         int remaining = nla_len(nla), vifi = 0;
2552
2553         while (rtnh_ok(rtnh, remaining)) {
2554                 mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2555                 if (++vifi == MAXVIFS)
2556                         break;
2557                 rtnh = rtnh_next(rtnh, &remaining);
2558         }
2559
2560         return remaining > 0 ? -EINVAL : vifi;
2561 }
2562
2563 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2564 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2565                             struct mfcctl *mfcc, int *mrtsock,
2566                             struct mr_table **mrtret,
2567                             struct netlink_ext_ack *extack)
2568 {
2569         struct net_device *dev = NULL;
2570         u32 tblid = RT_TABLE_DEFAULT;
2571         struct mr_table *mrt;
2572         struct nlattr *attr;
2573         struct rtmsg *rtm;
2574         int ret, rem;
2575
2576         ret = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy,
2577                              extack);
2578         if (ret < 0)
2579                 goto out;
2580         rtm = nlmsg_data(nlh);
2581
2582         ret = -EINVAL;
2583         if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2584             rtm->rtm_type != RTN_MULTICAST ||
2585             rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2586             !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2587                 goto out;
2588
2589         memset(mfcc, 0, sizeof(*mfcc));
2590         mfcc->mfcc_parent = -1;
2591         ret = 0;
2592         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2593                 switch (nla_type(attr)) {
2594                 case RTA_SRC:
2595                         mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2596                         break;
2597                 case RTA_DST:
2598                         mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2599                         break;
2600                 case RTA_IIF:
2601                         dev = __dev_get_by_index(net, nla_get_u32(attr));
2602                         if (!dev) {
2603                                 ret = -ENODEV;
2604                                 goto out;
2605                         }
2606                         break;
2607                 case RTA_MULTIPATH:
2608                         if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2609                                 ret = -EINVAL;
2610                                 goto out;
2611                         }
2612                         break;
2613                 case RTA_PREFSRC:
2614                         ret = 1;
2615                         break;
2616                 case RTA_TABLE:
2617                         tblid = nla_get_u32(attr);
2618                         break;
2619                 }
2620         }
2621         mrt = ipmr_get_table(net, tblid);
2622         if (!mrt) {
2623                 ret = -ENOENT;
2624                 goto out;
2625         }
2626         *mrtret = mrt;
2627         *mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2628         if (dev)
2629                 mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2630
2631 out:
2632         return ret;
2633 }
2634
2635 /* takes care of both newroute and delroute */
2636 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2637                           struct netlink_ext_ack *extack)
2638 {
2639         struct net *net = sock_net(skb->sk);
2640         int ret, mrtsock, parent;
2641         struct mr_table *tbl;
2642         struct mfcctl mfcc;
2643
2644         mrtsock = 0;
2645         tbl = NULL;
2646         ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2647         if (ret < 0)
2648                 return ret;
2649
2650         parent = ret ? mfcc.mfcc_parent : -1;
2651         if (nlh->nlmsg_type == RTM_NEWROUTE)
2652                 return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2653         else
2654                 return ipmr_mfc_delete(tbl, &mfcc, parent);
2655 }
2656
2657 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2658 {
2659         u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2660
2661         if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2662             nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2663             nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2664                         mrt->mroute_reg_vif_num) ||
2665             nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2666                        mrt->mroute_do_assert) ||
2667             nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim))
2668                 return false;
2669
2670         return true;
2671 }
2672
2673 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2674 {
2675         struct nlattr *vif_nest;
2676         struct vif_device *vif;
2677
2678         /* if the VIF doesn't exist just continue */
2679         if (!VIF_EXISTS(mrt, vifid))
2680                 return true;
2681
2682         vif = &mrt->vif_table[vifid];
2683         vif_nest = nla_nest_start(skb, IPMRA_VIF);
2684         if (!vif_nest)
2685                 return false;
2686         if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) ||
2687             nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2688             nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2689             nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2690                               IPMRA_VIFA_PAD) ||
2691             nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2692                               IPMRA_VIFA_PAD) ||
2693             nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2694                               IPMRA_VIFA_PAD) ||
2695             nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2696                               IPMRA_VIFA_PAD) ||
2697             nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2698             nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2699                 nla_nest_cancel(skb, vif_nest);
2700                 return false;
2701         }
2702         nla_nest_end(skb, vif_nest);
2703
2704         return true;
2705 }
2706
2707 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2708 {
2709         struct net *net = sock_net(skb->sk);
2710         struct nlmsghdr *nlh = NULL;
2711         unsigned int t = 0, s_t;
2712         unsigned int e = 0, s_e;
2713         struct mr_table *mrt;
2714
2715         s_t = cb->args[0];
2716         s_e = cb->args[1];
2717
2718         ipmr_for_each_table(mrt, net) {
2719                 struct nlattr *vifs, *af;
2720                 struct ifinfomsg *hdr;
2721                 u32 i;
2722
2723                 if (t < s_t)
2724                         goto skip_table;
2725                 nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2726                                 cb->nlh->nlmsg_seq, RTM_NEWLINK,
2727                                 sizeof(*hdr), NLM_F_MULTI);
2728                 if (!nlh)
2729                         break;
2730
2731                 hdr = nlmsg_data(nlh);
2732                 memset(hdr, 0, sizeof(*hdr));
2733                 hdr->ifi_family = RTNL_FAMILY_IPMR;
2734
2735                 af = nla_nest_start(skb, IFLA_AF_SPEC);
2736                 if (!af) {
2737                         nlmsg_cancel(skb, nlh);
2738                         goto out;
2739                 }
2740
2741                 if (!ipmr_fill_table(mrt, skb)) {
2742                         nlmsg_cancel(skb, nlh);
2743                         goto out;
2744                 }
2745
2746                 vifs = nla_nest_start(skb, IPMRA_TABLE_VIFS);
2747                 if (!vifs) {
2748                         nla_nest_end(skb, af);
2749                         nlmsg_end(skb, nlh);
2750                         goto out;
2751                 }
2752                 for (i = 0; i < mrt->maxvif; i++) {
2753                         if (e < s_e)
2754                                 goto skip_entry;
2755                         if (!ipmr_fill_vif(mrt, i, skb)) {
2756                                 nla_nest_end(skb, vifs);
2757                                 nla_nest_end(skb, af);
2758                                 nlmsg_end(skb, nlh);
2759                                 goto out;
2760                         }
2761 skip_entry:
2762                         e++;
2763                 }
2764                 s_e = 0;
2765                 e = 0;
2766                 nla_nest_end(skb, vifs);
2767                 nla_nest_end(skb, af);
2768                 nlmsg_end(skb, nlh);
2769 skip_table:
2770                 t++;
2771         }
2772
2773 out:
2774         cb->args[1] = e;
2775         cb->args[0] = t;
2776
2777         return skb->len;
2778 }
2779
2780 #ifdef CONFIG_PROC_FS
2781 /* The /proc interfaces to multicast routing :
2782  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2783  */
2784 struct ipmr_vif_iter {
2785         struct seq_net_private p;
2786         struct mr_table *mrt;
2787         int ct;
2788 };
2789
2790 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2791                                            struct ipmr_vif_iter *iter,
2792                                            loff_t pos)
2793 {
2794         struct mr_table *mrt = iter->mrt;
2795
2796         for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2797                 if (!VIF_EXISTS(mrt, iter->ct))
2798                         continue;
2799                 if (pos-- == 0)
2800                         return &mrt->vif_table[iter->ct];
2801         }
2802         return NULL;
2803 }
2804
2805 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2806         __acquires(mrt_lock)
2807 {
2808         struct ipmr_vif_iter *iter = seq->private;
2809         struct net *net = seq_file_net(seq);
2810         struct mr_table *mrt;
2811
2812         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2813         if (!mrt)
2814                 return ERR_PTR(-ENOENT);
2815
2816         iter->mrt = mrt;
2817
2818         read_lock(&mrt_lock);
2819         return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2820                 : SEQ_START_TOKEN;
2821 }
2822
2823 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2824 {
2825         struct ipmr_vif_iter *iter = seq->private;
2826         struct net *net = seq_file_net(seq);
2827         struct mr_table *mrt = iter->mrt;
2828
2829         ++*pos;
2830         if (v == SEQ_START_TOKEN)
2831                 return ipmr_vif_seq_idx(net, iter, 0);
2832
2833         while (++iter->ct < mrt->maxvif) {
2834                 if (!VIF_EXISTS(mrt, iter->ct))
2835                         continue;
2836                 return &mrt->vif_table[iter->ct];
2837         }
2838         return NULL;
2839 }
2840
2841 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2842         __releases(mrt_lock)
2843 {
2844         read_unlock(&mrt_lock);
2845 }
2846
2847 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2848 {
2849         struct ipmr_vif_iter *iter = seq->private;
2850         struct mr_table *mrt = iter->mrt;
2851
2852         if (v == SEQ_START_TOKEN) {
2853                 seq_puts(seq,
2854                          "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2855         } else {
2856                 const struct vif_device *vif = v;
2857                 const char *name =  vif->dev ? vif->dev->name : "none";
2858
2859                 seq_printf(seq,
2860                            "%2zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2861                            vif - mrt->vif_table,
2862                            name, vif->bytes_in, vif->pkt_in,
2863                            vif->bytes_out, vif->pkt_out,
2864                            vif->flags, vif->local, vif->remote);
2865         }
2866         return 0;
2867 }
2868
2869 static const struct seq_operations ipmr_vif_seq_ops = {
2870         .start = ipmr_vif_seq_start,
2871         .next  = ipmr_vif_seq_next,
2872         .stop  = ipmr_vif_seq_stop,
2873         .show  = ipmr_vif_seq_show,
2874 };
2875
2876 static int ipmr_vif_open(struct inode *inode, struct file *file)
2877 {
2878         return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2879                             sizeof(struct ipmr_vif_iter));
2880 }
2881
2882 static const struct file_operations ipmr_vif_fops = {
2883         .owner   = THIS_MODULE,
2884         .open    = ipmr_vif_open,
2885         .read    = seq_read,
2886         .llseek  = seq_lseek,
2887         .release = seq_release_net,
2888 };
2889
2890 struct ipmr_mfc_iter {
2891         struct seq_net_private p;
2892         struct mr_table *mrt;
2893         struct list_head *cache;
2894 };
2895
2896 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2897                                           struct ipmr_mfc_iter *it, loff_t pos)
2898 {
2899         struct mr_table *mrt = it->mrt;
2900         struct mfc_cache *mfc;
2901
2902         rcu_read_lock();
2903         it->cache = &mrt->mfc_cache_list;
2904         list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
2905                 if (pos-- == 0)
2906                         return mfc;
2907         rcu_read_unlock();
2908
2909         spin_lock_bh(&mfc_unres_lock);
2910         it->cache = &mrt->mfc_unres_queue;
2911         list_for_each_entry(mfc, it->cache, list)
2912                 if (pos-- == 0)
2913                         return mfc;
2914         spin_unlock_bh(&mfc_unres_lock);
2915
2916         it->cache = NULL;
2917         return NULL;
2918 }
2919
2920
2921 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2922 {
2923         struct ipmr_mfc_iter *it = seq->private;
2924         struct net *net = seq_file_net(seq);
2925         struct mr_table *mrt;
2926
2927         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2928         if (!mrt)
2929                 return ERR_PTR(-ENOENT);
2930
2931         it->mrt = mrt;
2932         it->cache = NULL;
2933         return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2934                 : SEQ_START_TOKEN;
2935 }
2936
2937 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2938 {
2939         struct ipmr_mfc_iter *it = seq->private;
2940         struct net *net = seq_file_net(seq);
2941         struct mr_table *mrt = it->mrt;
2942         struct mfc_cache *mfc = v;
2943
2944         ++*pos;
2945
2946         if (v == SEQ_START_TOKEN)
2947                 return ipmr_mfc_seq_idx(net, seq->private, 0);
2948
2949         if (mfc->list.next != it->cache)
2950                 return list_entry(mfc->list.next, struct mfc_cache, list);
2951
2952         if (it->cache == &mrt->mfc_unres_queue)
2953                 goto end_of_list;
2954
2955         /* exhausted cache_array, show unresolved */
2956         rcu_read_unlock();
2957         it->cache = &mrt->mfc_unres_queue;
2958
2959         spin_lock_bh(&mfc_unres_lock);
2960         if (!list_empty(it->cache))
2961                 return list_first_entry(it->cache, struct mfc_cache, list);
2962
2963 end_of_list:
2964         spin_unlock_bh(&mfc_unres_lock);
2965         it->cache = NULL;
2966
2967         return NULL;
2968 }
2969
2970 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2971 {
2972         struct ipmr_mfc_iter *it = seq->private;
2973         struct mr_table *mrt = it->mrt;
2974
2975         if (it->cache == &mrt->mfc_unres_queue)
2976                 spin_unlock_bh(&mfc_unres_lock);
2977         else if (it->cache == &mrt->mfc_cache_list)
2978                 rcu_read_unlock();
2979 }
2980
2981 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2982 {
2983         int n;
2984
2985         if (v == SEQ_START_TOKEN) {
2986                 seq_puts(seq,
2987                  "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2988         } else {
2989                 const struct mfc_cache *mfc = v;
2990                 const struct ipmr_mfc_iter *it = seq->private;
2991                 const struct mr_table *mrt = it->mrt;
2992
2993                 seq_printf(seq, "%08X %08X %-3hd",
2994                            (__force u32) mfc->mfc_mcastgrp,
2995                            (__force u32) mfc->mfc_origin,
2996                            mfc->mfc_parent);
2997
2998                 if (it->cache != &mrt->mfc_unres_queue) {
2999                         seq_printf(seq, " %8lu %8lu %8lu",
3000                                    mfc->mfc_un.res.pkt,
3001                                    mfc->mfc_un.res.bytes,
3002                                    mfc->mfc_un.res.wrong_if);
3003                         for (n = mfc->mfc_un.res.minvif;
3004                              n < mfc->mfc_un.res.maxvif; n++) {
3005                                 if (VIF_EXISTS(mrt, n) &&
3006                                     mfc->mfc_un.res.ttls[n] < 255)
3007                                         seq_printf(seq,
3008                                            " %2d:%-3d",
3009                                            n, mfc->mfc_un.res.ttls[n]);
3010                         }
3011                 } else {
3012                         /* unresolved mfc_caches don't contain
3013                          * pkt, bytes and wrong_if values
3014                          */
3015                         seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3016                 }
3017                 seq_putc(seq, '\n');
3018         }
3019         return 0;
3020 }
3021
3022 static const struct seq_operations ipmr_mfc_seq_ops = {
3023         .start = ipmr_mfc_seq_start,
3024         .next  = ipmr_mfc_seq_next,
3025         .stop  = ipmr_mfc_seq_stop,
3026         .show  = ipmr_mfc_seq_show,
3027 };
3028
3029 static int ipmr_mfc_open(struct inode *inode, struct file *file)
3030 {
3031         return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
3032                             sizeof(struct ipmr_mfc_iter));
3033 }
3034
3035 static const struct file_operations ipmr_mfc_fops = {
3036         .owner   = THIS_MODULE,
3037         .open    = ipmr_mfc_open,
3038         .read    = seq_read,
3039         .llseek  = seq_lseek,
3040         .release = seq_release_net,
3041 };
3042 #endif
3043
3044 #ifdef CONFIG_IP_PIMSM_V2
3045 static const struct net_protocol pim_protocol = {
3046         .handler        =       pim_rcv,
3047         .netns_ok       =       1,
3048 };
3049 #endif
3050
3051 /* Setup for IP multicast routing */
3052 static int __net_init ipmr_net_init(struct net *net)
3053 {
3054         int err;
3055
3056         err = ipmr_rules_init(net);
3057         if (err < 0)
3058                 goto fail;
3059
3060 #ifdef CONFIG_PROC_FS
3061         err = -ENOMEM;
3062         if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
3063                 goto proc_vif_fail;
3064         if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
3065                 goto proc_cache_fail;
3066 #endif
3067         return 0;
3068
3069 #ifdef CONFIG_PROC_FS
3070 proc_cache_fail:
3071         remove_proc_entry("ip_mr_vif", net->proc_net);
3072 proc_vif_fail:
3073         ipmr_rules_exit(net);
3074 #endif
3075 fail:
3076         return err;
3077 }
3078
3079 static void __net_exit ipmr_net_exit(struct net *net)
3080 {
3081 #ifdef CONFIG_PROC_FS
3082         remove_proc_entry("ip_mr_cache", net->proc_net);
3083         remove_proc_entry("ip_mr_vif", net->proc_net);
3084 #endif
3085         ipmr_rules_exit(net);
3086 }
3087
3088 static struct pernet_operations ipmr_net_ops = {
3089         .init = ipmr_net_init,
3090         .exit = ipmr_net_exit,
3091 };
3092
3093 int __init ip_mr_init(void)
3094 {
3095         int err;
3096
3097         mrt_cachep = kmem_cache_create("ip_mrt_cache",
3098                                        sizeof(struct mfc_cache),
3099                                        0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3100                                        NULL);
3101
3102         err = register_pernet_subsys(&ipmr_net_ops);
3103         if (err)
3104                 goto reg_pernet_fail;
3105
3106         err = register_netdevice_notifier(&ip_mr_notifier);
3107         if (err)
3108                 goto reg_notif_fail;
3109 #ifdef CONFIG_IP_PIMSM_V2
3110         if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3111                 pr_err("%s: can't add PIM protocol\n", __func__);
3112                 err = -EAGAIN;
3113                 goto add_proto_fail;
3114         }
3115 #endif
3116         rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3117                       ipmr_rtm_getroute, ipmr_rtm_dumproute, NULL);
3118         rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3119                       ipmr_rtm_route, NULL, NULL);
3120         rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3121                       ipmr_rtm_route, NULL, NULL);
3122
3123         rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3124                       NULL, ipmr_rtm_dumplink, NULL);
3125         return 0;
3126
3127 #ifdef CONFIG_IP_PIMSM_V2
3128 add_proto_fail:
3129         unregister_netdevice_notifier(&ip_mr_notifier);
3130 #endif
3131 reg_notif_fail:
3132         unregister_pernet_subsys(&ipmr_net_ops);
3133 reg_pernet_fail:
3134         kmem_cache_destroy(mrt_cachep);
3135         return err;
3136 }