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   1 /*
   2  * Bridge multicast support.
   3  *
   4  * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <linux/err.h>
  14 #include <linux/if_ether.h>
  15 #include <linux/igmp.h>
  16 #include <linux/jhash.h>
  17 #include <linux/kernel.h>
  18 #include <linux/log2.h>
  19 #include <linux/netdevice.h>
  20 #include <linux/netfilter_bridge.h>
  21 #include <linux/random.h>
  22 #include <linux/rculist.h>
  23 #include <linux/skbuff.h>
  24 #include <linux/slab.h>
  25 #include <linux/timer.h>
  26 #include <net/ip.h>
  27
  28 #include "br_private.h"
  29
  30 static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
  31 {
  32         return jhash_1word(mdb->secret, (u32)ip) & (mdb->max - 1);
  33 }
  34
  35 static struct net_bridge_mdb_entry *__br_mdb_ip_get(
  36         struct net_bridge_mdb_htable *mdb, __be32 dst, int hash)
  37 {
  38         struct net_bridge_mdb_entry *mp;
  39         struct hlist_node *p;
  40
  41         hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
  42                 if (dst == mp->addr)
  43                         return mp;
  44         }
  45
  46         return NULL;
  47 }
  48
  49 static struct net_bridge_mdb_entry *br_mdb_ip_get(
  50         struct net_bridge_mdb_htable *mdb, __be32 dst)
  51 {
  52         return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
  53 }
  54
  55 struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
  56                                         struct sk_buff *skb)
  57 {
  58         struct net_bridge_mdb_htable *mdb = br->mdb;
  59
  60         if (!mdb || br->multicast_disabled)
  61                 return NULL;
  62
  63         switch (skb->protocol) {
  64         case htons(ETH_P_IP):
  65                 if (BR_INPUT_SKB_CB(skb)->igmp)
  66                         break;
  67                 return br_mdb_ip_get(mdb, ip_hdr(skb)->daddr);
  68         }
  69
  70         return NULL;
  71 }
  72
  73 static void br_mdb_free(struct rcu_head *head)
  74 {
  75         struct net_bridge_mdb_htable *mdb =
  76                 container_of(head, struct net_bridge_mdb_htable, rcu);
  77         struct net_bridge_mdb_htable *old = mdb->old;
  78
  79         mdb->old = NULL;
  80         kfree(old->mhash);
  81         kfree(old);
  82 }
  83
  84 static int br_mdb_copy(struct net_bridge_mdb_htable *new,
  85                        struct net_bridge_mdb_htable *old,
  86                        int elasticity)
  87 {
  88         struct net_bridge_mdb_entry *mp;
  89         struct hlist_node *p;
  90         int maxlen;
  91         int len;
  92         int i;
  93
  94         for (i = 0; i < old->max; i++)
  95                 hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
  96                         hlist_add_head(&mp->hlist[new->ver],
  97                                        &new->mhash[br_ip_hash(new, mp->addr)]);
  98
  99         if (!elasticity)
 100                 return 0;
 101
 102         maxlen = 0;
 103         for (i = 0; i < new->max; i++) {
 104                 len = 0;
 105                 hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
 106                         len++;
 107                 if (len > maxlen)
 108                         maxlen = len;
 109         }
 110
 111         return maxlen > elasticity ? -EINVAL : 0;
 112 }
 113
 114 static void br_multicast_free_pg(struct rcu_head *head)
 115 {
 116         struct net_bridge_port_group *p =
 117                 container_of(head, struct net_bridge_port_group, rcu);
 118
 119         kfree(p);
 120 }
 121
 122 static void br_multicast_free_group(struct rcu_head *head)
 123 {
 124         struct net_bridge_mdb_entry *mp =
 125                 container_of(head, struct net_bridge_mdb_entry, rcu);
 126
 127         kfree(mp);
 128 }
 129
 130 static void br_multicast_group_expired(unsigned long data)
 131 {
 132         struct net_bridge_mdb_entry *mp = (void *)data;
 133         struct net_bridge *br = mp->br;
 134         struct net_bridge_mdb_htable *mdb;
 135
 136         spin_lock(&br->multicast_lock);
 137         if (!netif_running(br->dev) || timer_pending(&mp->timer))
 138                 goto out;
 139
 140         if (!hlist_unhashed(&mp->mglist))
 141                 hlist_del_init(&mp->mglist);
 142
 143         if (mp->ports)
 144                 goto out;
 145
 146         mdb = br->mdb;
 147         hlist_del_rcu(&mp->hlist[mdb->ver]);
 148         mdb->size--;
 149
 150         del_timer(&mp->query_timer);
 151         call_rcu_bh(&mp->rcu, br_multicast_free_group);
 152
 153 out:
 154         spin_unlock(&br->multicast_lock);
 155 }
 156
 157 static void br_multicast_del_pg(struct net_bridge *br,
 158                                 struct net_bridge_port_group *pg)
 159 {
 160         struct net_bridge_mdb_htable *mdb = br->mdb;
 161         struct net_bridge_mdb_entry *mp;
 162         struct net_bridge_port_group *p;
 163         struct net_bridge_port_group **pp;
 164
 165         mp = br_mdb_ip_get(mdb, pg->addr);
 166         if (WARN_ON(!mp))
 167                 return;
 168
 169         for (pp = &mp->ports; (p = *pp); pp = &p->next) {
 170                 if (p != pg)
 171                         continue;
 172
 173                 *pp = p->next;
 174                 hlist_del_init(&p->mglist);
 175                 del_timer(&p->timer);
 176                 del_timer(&p->query_timer);
 177                 call_rcu_bh(&p->rcu, br_multicast_free_pg);
 178
 179                 if (!mp->ports && hlist_unhashed(&mp->mglist) &&
 180                     netif_running(br->dev))
 181                         mod_timer(&mp->timer, jiffies);
 182
 183                 return;
 184         }
 185
 186         WARN_ON(1);
 187 }
 188
 189 static void br_multicast_port_group_expired(unsigned long data)
 190 {
 191         struct net_bridge_port_group *pg = (void *)data;
 192         struct net_bridge *br = pg->port->br;
 193
 194         spin_lock(&br->multicast_lock);
 195         if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
 196             hlist_unhashed(&pg->mglist))
 197                 goto out;
 198
 199         br_multicast_del_pg(br, pg);
 200
 201 out:
 202         spin_unlock(&br->multicast_lock);
 203 }
 204
 205 static int br_mdb_rehash(struct net_bridge_mdb_htable **mdbp, int max,
 206                          int elasticity)
 207 {
 208         struct net_bridge_mdb_htable *old = *mdbp;
 209         struct net_bridge_mdb_htable *mdb;
 210         int err;
 211
 212         mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
 213         if (!mdb)
 214                 return -ENOMEM;
 215
 216         mdb->max = max;
 217         mdb->old = old;
 218
 219         mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
 220         if (!mdb->mhash) {
 221                 kfree(mdb);
 222                 return -ENOMEM;
 223         }
 224
 225         mdb->size = old ? old->size : 0;
 226         mdb->ver = old ? old->ver ^ 1 : 0;
 227
 228         if (!old || elasticity)
 229                 get_random_bytes(&mdb->secret, sizeof(mdb->secret));
 230         else
 231                 mdb->secret = old->secret;
 232
 233         if (!old)
 234                 goto out;
 235
 236         err = br_mdb_copy(mdb, old, elasticity);
 237         if (err) {
 238                 kfree(mdb->mhash);
 239                 kfree(mdb);
 240                 return err;
 241         }
 242
 243         call_rcu_bh(&mdb->rcu, br_mdb_free);
 244
 245 out:
 246         rcu_assign_pointer(*mdbp, mdb);
 247
 248         return 0;
 249 }
 250
 251 static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
 252                                                 __be32 group)
 253 {
 254         struct sk_buff *skb;
 255         struct igmphdr *ih;
 256         struct ethhdr *eth;
 257         struct iphdr *iph;
 258
 259         skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
 260                                                  sizeof(*ih) + 4);
 261         if (!skb)
 262                 goto out;
 263
 264         skb->protocol = htons(ETH_P_IP);
 265
 266         skb_reset_mac_header(skb);
 267         eth = eth_hdr(skb);
 268
 269         memcpy(eth->h_source, br->dev->dev_addr, 6);
 270         eth->h_dest[0] = 1;
 271         eth->h_dest[1] = 0;
 272         eth->h_dest[2] = 0x5e;
 273         eth->h_dest[3] = 0;
 274         eth->h_dest[4] = 0;
 275         eth->h_dest[5] = 1;
 276         eth->h_proto = htons(ETH_P_IP);
 277         skb_put(skb, sizeof(*eth));
 278
 279         skb_set_network_header(skb, skb->len);
 280         iph = ip_hdr(skb);
 281
 282         iph->version = 4;
 283         iph->ihl = 6;
 284         iph->tos = 0xc0;
 285         iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
 286         iph->id = 0;
 287         iph->frag_off = htons(IP_DF);
 288         iph->ttl = 1;
 289         iph->protocol = IPPROTO_IGMP;
 290         iph->saddr = 0;
 291         iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
 292         ((u8 *)&iph[1])[0] = IPOPT_RA;
 293         ((u8 *)&iph[1])[1] = 4;
 294         ((u8 *)&iph[1])[2] = 0;
 295         ((u8 *)&iph[1])[3] = 0;
 296         ip_send_check(iph);
 297         skb_put(skb, 24);
 298
 299         skb_set_transport_header(skb, skb->len);
 300         ih = igmp_hdr(skb);
 301         ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
 302         ih->code = (group ? br->multicast_last_member_interval :
 303                             br->multicast_query_response_interval) /
 304                    (HZ / IGMP_TIMER_SCALE);
 305         ih->group = group;
 306         ih->csum = 0;
 307         ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
 308         skb_put(skb, sizeof(*ih));
 309
 310         __skb_pull(skb, sizeof(*eth));
 311
 312 out:
 313         return skb;
 314 }
 315
 316 static void br_multicast_send_group_query(struct net_bridge_mdb_entry *mp)
 317 {
 318         struct net_bridge *br = mp->br;
 319         struct sk_buff *skb;
 320
 321         skb = br_multicast_alloc_query(br, mp->addr);
 322         if (!skb)
 323                 goto timer;
 324
 325         netif_rx(skb);
 326
 327 timer:
 328         if (++mp->queries_sent < br->multicast_last_member_count)
 329                 mod_timer(&mp->query_timer,
 330                           jiffies + br->multicast_last_member_interval);
 331 }
 332
 333 static void br_multicast_group_query_expired(unsigned long data)
 334 {
 335         struct net_bridge_mdb_entry *mp = (void *)data;
 336         struct net_bridge *br = mp->br;
 337
 338         spin_lock(&br->multicast_lock);
 339         if (!netif_running(br->dev) || hlist_unhashed(&mp->mglist) ||
 340             mp->queries_sent >= br->multicast_last_member_count)
 341                 goto out;
 342
 343         br_multicast_send_group_query(mp);
 344
 345 out:
 346         spin_unlock(&br->multicast_lock);
 347 }
 348
 349 static void br_multicast_send_port_group_query(struct net_bridge_port_group *pg)
 350 {
 351         struct net_bridge_port *port = pg->port;
 352         struct net_bridge *br = port->br;
 353         struct sk_buff *skb;
 354
 355         skb = br_multicast_alloc_query(br, pg->addr);
 356         if (!skb)
 357                 goto timer;
 358
 359         br_deliver(port, skb);
 360
 361 timer:
 362         if (++pg->queries_sent < br->multicast_last_member_count)
 363                 mod_timer(&pg->query_timer,
 364                           jiffies + br->multicast_last_member_interval);
 365 }
 366
 367 static void br_multicast_port_group_query_expired(unsigned long data)
 368 {
 369         struct net_bridge_port_group *pg = (void *)data;
 370         struct net_bridge_port *port = pg->port;
 371         struct net_bridge *br = port->br;
 372
 373         spin_lock(&br->multicast_lock);
 374         if (!netif_running(br->dev) || hlist_unhashed(&pg->mglist) ||
 375             pg->queries_sent >= br->multicast_last_member_count)
 376                 goto out;
 377
 378         br_multicast_send_port_group_query(pg);
 379
 380 out:
 381         spin_unlock(&br->multicast_lock);
 382 }
 383
 384 static struct net_bridge_mdb_entry *br_multicast_get_group(
 385         struct net_bridge *br, struct net_bridge_port *port, __be32 group,
 386         int hash)
 387 {
 388         struct net_bridge_mdb_htable *mdb = br->mdb;
 389         struct net_bridge_mdb_entry *mp;
 390         struct hlist_node *p;
 391         unsigned count = 0;
 392         unsigned max;
 393         int elasticity;
 394         int err;
 395
 396         hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
 397                 count++;
 398                 if (unlikely(group == mp->addr)) {
 399                         return mp;
 400                 }
 401         }
 402
 403         elasticity = 0;
 404         max = mdb->max;
 405
 406         if (unlikely(count > br->hash_elasticity && count)) {
 407                 if (net_ratelimit())
 408                         printk(KERN_INFO "%s: Multicast hash table "
 409                                "chain limit reached: %s\n",
 410                                br->dev->name, port ? port->dev->name :
 411                                                      br->dev->name);
 412
 413                 elasticity = br->hash_elasticity;
 414         }
 415
 416         if (mdb->size >= max) {
 417                 max *= 2;
 418                 if (unlikely(max >= br->hash_max)) {
 419                         printk(KERN_WARNING "%s: Multicast hash table maximum "
 420                                "reached, disabling snooping: %s, %d\n",
 421                                br->dev->name, port ? port->dev->name :
 422                                                      br->dev->name,
 423                                max);
 424                         err = -E2BIG;
 425 disable:
 426                         br->multicast_disabled = 1;
 427                         goto err;
 428                 }
 429         }
 430
 431         if (max > mdb->max || elasticity) {
 432                 if (mdb->old) {
 433                         if (net_ratelimit())
 434                                 printk(KERN_INFO "%s: Multicast hash table "
 435                                        "on fire: %s\n",
 436                                        br->dev->name, port ? port->dev->name :
 437                                                              br->dev->name);
 438                         err = -EEXIST;
 439                         goto err;
 440                 }
 441
 442                 err = br_mdb_rehash(&br->mdb, max, elasticity);
 443                 if (err) {
 444                         printk(KERN_WARNING "%s: Cannot rehash multicast "
 445                                "hash table, disabling snooping: "
 446                                "%s, %d, %d\n",
 447                                br->dev->name, port ? port->dev->name :
 448                                                      br->dev->name,
 449                                mdb->size, err);
 450                         goto disable;
 451                 }
 452
 453                 err = -EAGAIN;
 454                 goto err;
 455         }
 456
 457         return NULL;
 458
 459 err:
 460         mp = ERR_PTR(err);
 461         return mp;
 462 }
 463
 464 static struct net_bridge_mdb_entry *br_multicast_new_group(
 465         struct net_bridge *br, struct net_bridge_port *port, __be32 group)
 466 {
 467         struct net_bridge_mdb_htable *mdb = br->mdb;
 468         struct net_bridge_mdb_entry *mp;
 469         int hash;
 470
 471         if (!mdb) {
 472                 if (br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0))
 473                         return NULL;
 474                 goto rehash;
 475         }
 476
 477         hash = br_ip_hash(mdb, group);
 478         mp = br_multicast_get_group(br, port, group, hash);
 479         switch (PTR_ERR(mp)) {
 480         case 0:
 481                 break;
 482
 483         case -EAGAIN:
 484 rehash:
 485                 mdb = br->mdb;
 486                 hash = br_ip_hash(mdb, group);
 487                 break;
 488
 489         default:
 490                 goto out;
 491         }
 492
 493         mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
 494         if (unlikely(!mp))
 495                 goto out;
 496
 497         mp->br = br;
 498         mp->addr = group;
 499         setup_timer(&mp->timer, br_multicast_group_expired,
 500                     (unsigned long)mp);
 501         setup_timer(&mp->query_timer, br_multicast_group_query_expired,
 502                     (unsigned long)mp);
 503
 504         hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
 505         mdb->size++;
 506
 507 out:
 508         return mp;
 509 }
 510
 511 static int br_multicast_add_group(struct net_bridge *br,
 512                                   struct net_bridge_port *port, __be32 group)
 513 {
 514         struct net_bridge_mdb_entry *mp;
 515         struct net_bridge_port_group *p;
 516         struct net_bridge_port_group **pp;
 517         unsigned long now = jiffies;
 518         int err;
 519
 520         if (ipv4_is_local_multicast(group))
 521                 return 0;
 522
 523         spin_lock(&br->multicast_lock);
 524         if (!netif_running(br->dev) ||
 525             (port && port->state == BR_STATE_DISABLED))
 526                 goto out;
 527
 528         mp = br_multicast_new_group(br, port, group);
 529         err = PTR_ERR(mp);
 530         if (unlikely(IS_ERR(mp) || !mp))
 531                 goto err;
 532
 533         if (!port) {
 534                 hlist_add_head(&mp->mglist, &br->mglist);
 535                 mod_timer(&mp->timer, now + br->multicast_membership_interval);
 536                 goto out;
 537         }
 538
 539         for (pp = &mp->ports; (p = *pp); pp = &p->next) {
 540                 if (p->port == port)
 541                         goto found;
 542                 if ((unsigned long)p->port < (unsigned long)port)
 543                         break;
 544         }
 545
 546         p = kzalloc(sizeof(*p), GFP_ATOMIC);
 547         err = -ENOMEM;
 548         if (unlikely(!p))
 549                 goto err;
 550
 551         p->addr = group;
 552         p->port = port;
 553         p->next = *pp;
 554         hlist_add_head(&p->mglist, &port->mglist);
 555         setup_timer(&p->timer, br_multicast_port_group_expired,
 556                     (unsigned long)p);
 557         setup_timer(&p->query_timer, br_multicast_port_group_query_expired,
 558                     (unsigned long)p);
 559
 560         rcu_assign_pointer(*pp, p);
 561
 562 found:
 563         mod_timer(&p->timer, now + br->multicast_membership_interval);
 564 out:
 565         err = 0;
 566
 567 err:
 568         spin_unlock(&br->multicast_lock);
 569         return err;
 570 }
 571
 572 static void br_multicast_router_expired(unsigned long data)
 573 {
 574         struct net_bridge_port *port = (void *)data;
 575         struct net_bridge *br = port->br;
 576
 577         spin_lock(&br->multicast_lock);
 578         if (port->multicast_router != 1 ||
 579             timer_pending(&port->multicast_router_timer) ||
 580             hlist_unhashed(&port->rlist))
 581                 goto out;
 582
 583         hlist_del_init_rcu(&port->rlist);
 584
 585 out:
 586         spin_unlock(&br->multicast_lock);
 587 }
 588
 589 static void br_multicast_local_router_expired(unsigned long data)
 590 {
 591 }
 592
 593 static void br_multicast_send_query(struct net_bridge *br,
 594                                     struct net_bridge_port *port, u32 sent)
 595 {
 596         unsigned long time;
 597         struct sk_buff *skb;
 598
 599         if (!netif_running(br->dev) || br->multicast_disabled ||
 600             timer_pending(&br->multicast_querier_timer))
 601                 return;
 602
 603         skb = br_multicast_alloc_query(br, 0);
 604         if (!skb)
 605                 goto timer;
 606
 607         if (port) {
 608                 __skb_push(skb, sizeof(struct ethhdr));
 609                 skb->dev = port->dev;
 610                 NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
 611                         dev_queue_xmit);
 612         } else
 613                 netif_rx(skb);
 614
 615 timer:
 616         time = jiffies;
 617         time += sent < br->multicast_startup_query_count ?
 618                 br->multicast_startup_query_interval :
 619                 br->multicast_query_interval;
 620         mod_timer(port ? &port->multicast_query_timer :
 621                          &br->multicast_query_timer, time);
 622 }
 623
 624 static void br_multicast_port_query_expired(unsigned long data)
 625 {
 626         struct net_bridge_port *port = (void *)data;
 627         struct net_bridge *br = port->br;
 628
 629         spin_lock(&br->multicast_lock);
 630         if (port->state == BR_STATE_DISABLED ||
 631             port->state == BR_STATE_BLOCKING)
 632                 goto out;
 633
 634         if (port->multicast_startup_queries_sent <
 635             br->multicast_startup_query_count)
 636                 port->multicast_startup_queries_sent++;
 637
 638         br_multicast_send_query(port->br, port,
 639                                 port->multicast_startup_queries_sent);
 640
 641 out:
 642         spin_unlock(&br->multicast_lock);
 643 }
 644
 645 void br_multicast_add_port(struct net_bridge_port *port)
 646 {
 647         port->multicast_router = 1;
 648
 649         setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
 650                     (unsigned long)port);
 651         setup_timer(&port->multicast_query_timer,
 652                     br_multicast_port_query_expired, (unsigned long)port);
 653 }
 654
 655 void br_multicast_del_port(struct net_bridge_port *port)
 656 {
 657         del_timer_sync(&port->multicast_router_timer);
 658 }
 659
 660 static void __br_multicast_enable_port(struct net_bridge_port *port)
 661 {
 662         port->multicast_startup_queries_sent = 0;
 663
 664         if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
 665             del_timer(&port->multicast_query_timer))
 666                 mod_timer(&port->multicast_query_timer, jiffies);
 667 }
 668
 669 void br_multicast_enable_port(struct net_bridge_port *port)
 670 {
 671         struct net_bridge *br = port->br;
 672
 673         spin_lock(&br->multicast_lock);
 674         if (br->multicast_disabled || !netif_running(br->dev))
 675                 goto out;
 676
 677         __br_multicast_enable_port(port);
 678
 679 out:
 680         spin_unlock(&br->multicast_lock);
 681 }
 682
 683 void br_multicast_disable_port(struct net_bridge_port *port)
 684 {
 685         struct net_bridge *br = port->br;
 686         struct net_bridge_port_group *pg;
 687         struct hlist_node *p, *n;
 688
 689         spin_lock(&br->multicast_lock);
 690         hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
 691                 br_multicast_del_pg(br, pg);
 692
 693         if (!hlist_unhashed(&port->rlist))
 694                 hlist_del_init_rcu(&port->rlist);
 695         del_timer(&port->multicast_router_timer);
 696         del_timer(&port->multicast_query_timer);
 697         spin_unlock(&br->multicast_lock);
 698 }
 699
 700 static int br_multicast_igmp3_report(struct net_bridge *br,
 701                                      struct net_bridge_port *port,
 702                                      struct sk_buff *skb)
 703 {
 704         struct igmpv3_report *ih;
 705         struct igmpv3_grec *grec;
 706         int i;
 707         int len;
 708         int num;
 709         int type;
 710         int err = 0;
 711         __be32 group;
 712
 713         if (!pskb_may_pull(skb, sizeof(*ih)))
 714                 return -EINVAL;
 715
 716         ih = igmpv3_report_hdr(skb);
 717         num = ntohs(ih->ngrec);
 718         len = sizeof(*ih);
 719
 720         for (i = 0; i < num; i++) {
 721                 len += sizeof(*grec);
 722                 if (!pskb_may_pull(skb, len))
 723                         return -EINVAL;
 724
 725                 grec = (void *)(skb->data + len);
 726                 group = grec->grec_mca;
 727                 type = grec->grec_type;
 728
 729                 len += grec->grec_nsrcs * 4;
 730                 if (!pskb_may_pull(skb, len))
 731                         return -EINVAL;
 732
 733                 /* We treat this as an IGMPv2 report for now. */
 734                 switch (type) {
 735                 case IGMPV3_MODE_IS_INCLUDE:
 736                 case IGMPV3_MODE_IS_EXCLUDE:
 737                 case IGMPV3_CHANGE_TO_INCLUDE:
 738                 case IGMPV3_CHANGE_TO_EXCLUDE:
 739                 case IGMPV3_ALLOW_NEW_SOURCES:
 740                 case IGMPV3_BLOCK_OLD_SOURCES:
 741                         break;
 742
 743                 default:
 744                         continue;
 745                 }
 746
 747                 err = br_multicast_add_group(br, port, group);
 748                 if (err)
 749                         break;
 750         }
 751
 752         return err;
 753 }
 754
 755 static void br_multicast_add_router(struct net_bridge *br,
 756                                     struct net_bridge_port *port)
 757 {
 758         struct hlist_node *p;
 759         struct hlist_node **h;
 760
 761         for (h = &br->router_list.first;
 762              (p = *h) &&
 763              (unsigned long)container_of(p, struct net_bridge_port, rlist) >
 764              (unsigned long)port;
 765              h = &p->next)
 766                 ;
 767
 768         port->rlist.pprev = h;
 769         port->rlist.next = p;
 770         rcu_assign_pointer(*h, &port->rlist);
 771         if (p)
 772                 p->pprev = &port->rlist.next;
 773 }
 774
 775 static void br_multicast_mark_router(struct net_bridge *br,
 776                                      struct net_bridge_port *port)
 777 {
 778         unsigned long now = jiffies;
 779
 780         if (!port) {
 781                 if (br->multicast_router == 1)
 782                         mod_timer(&br->multicast_router_timer,
 783                                   now + br->multicast_querier_interval);
 784                 return;
 785         }
 786
 787         if (port->multicast_router != 1)
 788                 return;
 789
 790         if (!hlist_unhashed(&port->rlist))
 791                 goto timer;
 792
 793         br_multicast_add_router(br, port);
 794
 795 timer:
 796         mod_timer(&port->multicast_router_timer,
 797                   now + br->multicast_querier_interval);
 798 }
 799
 800 static void br_multicast_query_received(struct net_bridge *br,
 801                                         struct net_bridge_port *port,
 802                                         __be32 saddr)
 803 {
 804         if (saddr)
 805                 mod_timer(&br->multicast_querier_timer,
 806                           jiffies + br->multicast_querier_interval);
 807         else if (timer_pending(&br->multicast_querier_timer))
 808                 return;
 809
 810         br_multicast_mark_router(br, port);
 811 }
 812
 813 static int br_multicast_query(struct net_bridge *br,
 814                               struct net_bridge_port *port,
 815                               struct sk_buff *skb)
 816 {
 817         struct iphdr *iph = ip_hdr(skb);
 818         struct igmphdr *ih = igmp_hdr(skb);
 819         struct net_bridge_mdb_entry *mp;
 820         struct igmpv3_query *ih3;
 821         struct net_bridge_port_group *p;
 822         struct net_bridge_port_group **pp;
 823         unsigned long max_delay;
 824         unsigned long now = jiffies;
 825         __be32 group;
 826
 827         spin_lock(&br->multicast_lock);
 828         if (!netif_running(br->dev) ||
 829             (port && port->state == BR_STATE_DISABLED))
 830                 goto out;
 831
 832         br_multicast_query_received(br, port, iph->saddr);
 833
 834         group = ih->group;
 835
 836         if (skb->len == sizeof(*ih)) {
 837                 max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
 838
 839                 if (!max_delay) {
 840                         max_delay = 10 * HZ;
 841                         group = 0;
 842                 }
 843         } else {
 844                 if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
 845                         return -EINVAL;
 846
 847                 ih3 = igmpv3_query_hdr(skb);
 848                 if (ih3->nsrcs)
 849                         return 0;
 850
 851                 max_delay = ih3->code ? 1 :
 852                             IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE);
 853         }
 854
 855         if (!group)
 856                 goto out;
 857
 858         mp = br_mdb_ip_get(br->mdb, group);
 859         if (!mp)
 860                 goto out;
 861
 862         max_delay *= br->multicast_last_member_count;
 863
 864         if (!hlist_unhashed(&mp->mglist) &&
 865             (timer_pending(&mp->timer) ?
 866              time_after(mp->timer.expires, now + max_delay) :
 867              try_to_del_timer_sync(&mp->timer) >= 0))
 868                 mod_timer(&mp->timer, now + max_delay);
 869
 870         for (pp = &mp->ports; (p = *pp); pp = &p->next) {
 871                 if (timer_pending(&p->timer) ?
 872                     time_after(p->timer.expires, now + max_delay) :
 873                     try_to_del_timer_sync(&p->timer) >= 0)
 874                         mod_timer(&mp->timer, now + max_delay);
 875         }
 876
 877 out:
 878         spin_unlock(&br->multicast_lock);
 879         return 0;
 880 }
 881
 882 static void br_multicast_leave_group(struct net_bridge *br,
 883                                      struct net_bridge_port *port,
 884                                      __be32 group)
 885 {
 886         struct net_bridge_mdb_htable *mdb;
 887         struct net_bridge_mdb_entry *mp;
 888         struct net_bridge_port_group *p;
 889         unsigned long now;
 890         unsigned long time;
 891
 892         if (ipv4_is_local_multicast(group))
 893                 return;
 894
 895         spin_lock(&br->multicast_lock);
 896         if (!netif_running(br->dev) ||
 897             (port && port->state == BR_STATE_DISABLED) ||
 898             timer_pending(&br->multicast_querier_timer))
 899                 goto out;
 900
 901         mdb = br->mdb;
 902         mp = br_mdb_ip_get(mdb, group);
 903         if (!mp)
 904                 goto out;
 905
 906         now = jiffies;
 907         time = now + br->multicast_last_member_count *
 908                      br->multicast_last_member_interval;
 909
 910         if (!port) {
 911                 if (!hlist_unhashed(&mp->mglist) &&
 912                     (timer_pending(&mp->timer) ?
 913                      time_after(mp->timer.expires, time) :
 914                      try_to_del_timer_sync(&mp->timer) >= 0)) {
 915                         mod_timer(&mp->timer, time);
 916
 917                         mp->queries_sent = 0;
 918                         mod_timer(&mp->query_timer, now);
 919                 }
 920
 921                 goto out;
 922         }
 923
 924         for (p = mp->ports; p; p = p->next) {
 925                 if (p->port != port)
 926                         continue;
 927
 928                 if (!hlist_unhashed(&p->mglist) &&
 929                     (timer_pending(&p->timer) ?
 930                      time_after(p->timer.expires, time) :
 931                      try_to_del_timer_sync(&p->timer) >= 0)) {
 932                         mod_timer(&p->timer, time);
 933
 934                         p->queries_sent = 0;
 935                         mod_timer(&p->query_timer, now);
 936                 }
 937
 938                 break;
 939         }
 940
 941 out:
 942         spin_unlock(&br->multicast_lock);
 943 }
 944
 945 static int br_multicast_ipv4_rcv(struct net_bridge *br,
 946                                  struct net_bridge_port *port,
 947                                  struct sk_buff *skb)
 948 {
 949         struct sk_buff *skb2 = skb;
 950         struct iphdr *iph;
 951         struct igmphdr *ih;
 952         unsigned len;
 953         unsigned offset;
 954         int err;
 955
 956         BR_INPUT_SKB_CB(skb)->igmp = 0;
 957         BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
 958
 959         /* We treat OOM as packet loss for now. */
 960         if (!pskb_may_pull(skb, sizeof(*iph)))
 961                 return -EINVAL;
 962
 963         iph = ip_hdr(skb);
 964
 965         if (iph->ihl < 5 || iph->version != 4)
 966                 return -EINVAL;
 967
 968         if (!pskb_may_pull(skb, ip_hdrlen(skb)))
 969                 return -EINVAL;
 970
 971         iph = ip_hdr(skb);
 972
 973         if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
 974                 return -EINVAL;
 975
 976         if (iph->protocol != IPPROTO_IGMP)
 977                 return 0;
 978
 979         len = ntohs(iph->tot_len);
 980         if (skb->len < len || len < ip_hdrlen(skb))
 981                 return -EINVAL;
 982
 983         if (skb->len > len) {
 984                 skb2 = skb_clone(skb, GFP_ATOMIC);
 985                 if (!skb2)
 986                         return -ENOMEM;
 987
 988                 err = pskb_trim_rcsum(skb2, len);
 989                 if (err)
 990                         return err;
 991         }
 992
 993         len -= ip_hdrlen(skb2);
 994         offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
 995         __skb_pull(skb2, offset);
 996         skb_reset_transport_header(skb2);
 997
 998         err = -EINVAL;
 999         if (!pskb_may_pull(skb2, sizeof(*ih)))
1000                 goto out;
1001
1002         iph = ip_hdr(skb2);
1003
1004         switch (skb2->ip_summed) {
1005         case CHECKSUM_COMPLETE:
1006                 if (!csum_fold(skb2->csum))
1007                         break;
1008                 /* fall through */
1009         case CHECKSUM_NONE:
1010                 skb2->csum = 0;
1011                 if (skb_checksum_complete(skb2))
1012                         return -EINVAL;
1013         }
1014
1015         err = 0;
1016
1017         BR_INPUT_SKB_CB(skb)->igmp = 1;
1018         ih = igmp_hdr(skb2);
1019
1020         switch (ih->type) {
1021         case IGMP_HOST_MEMBERSHIP_REPORT:
1022         case IGMPV2_HOST_MEMBERSHIP_REPORT:
1023                 BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
1024                 err = br_multicast_add_group(br, port, ih->group);
1025                 break;
1026         case IGMPV3_HOST_MEMBERSHIP_REPORT:
1027                 err = br_multicast_igmp3_report(br, port, skb2);
1028                 break;
1029         case IGMP_HOST_MEMBERSHIP_QUERY:
1030                 err = br_multicast_query(br, port, skb2);
1031                 break;
1032         case IGMP_HOST_LEAVE_MESSAGE:
1033                 br_multicast_leave_group(br, port, ih->group);
1034                 break;
1035         }
1036
1037 out:
1038         __skb_push(skb2, offset);
1039         if (skb2 != skb)
1040                 kfree_skb(skb2);
1041         return err;
1042 }
1043
1044 int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1045                      struct sk_buff *skb)
1046 {
1047         if (br->multicast_disabled)
1048                 return 0;
1049
1050         switch (skb->protocol) {
1051         case htons(ETH_P_IP):
1052                 return br_multicast_ipv4_rcv(br, port, skb);
1053         }
1054
1055         return 0;
1056 }
1057
1058 static void br_multicast_query_expired(unsigned long data)
1059 {
1060         struct net_bridge *br = (void *)data;
1061
1062         spin_lock(&br->multicast_lock);
1063         if (br->multicast_startup_queries_sent <
1064             br->multicast_startup_query_count)
1065                 br->multicast_startup_queries_sent++;
1066
1067         br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1068
1069         spin_unlock(&br->multicast_lock);
1070 }
1071
1072 void br_multicast_init(struct net_bridge *br)
1073 {
1074         br->hash_elasticity = 4;
1075         br->hash_max = 512;
1076
1077         br->multicast_router = 1;
1078         br->multicast_last_member_count = 2;
1079         br->multicast_startup_query_count = 2;
1080
1081         br->multicast_last_member_interval = HZ;
1082         br->multicast_query_response_interval = 10 * HZ;
1083         br->multicast_startup_query_interval = 125 * HZ / 4;
1084         br->multicast_query_interval = 125 * HZ;
1085         br->multicast_querier_interval = 255 * HZ;
1086         br->multicast_membership_interval = 260 * HZ;
1087
1088         spin_lock_init(&br->multicast_lock);
1089         setup_timer(&br->multicast_router_timer,
1090                     br_multicast_local_router_expired, 0);
1091         setup_timer(&br->multicast_querier_timer,
1092                     br_multicast_local_router_expired, 0);
1093         setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1094                     (unsigned long)br);
1095 }
1096
1097 void br_multicast_open(struct net_bridge *br)
1098 {
1099         br->multicast_startup_queries_sent = 0;
1100
1101         if (br->multicast_disabled)
1102                 return;
1103
1104         mod_timer(&br->multicast_query_timer, jiffies);
1105 }
1106
1107 void br_multicast_stop(struct net_bridge *br)
1108 {
1109         struct net_bridge_mdb_htable *mdb;
1110         struct net_bridge_mdb_entry *mp;
1111         struct hlist_node *p, *n;
1112         u32 ver;
1113         int i;
1114
1115         del_timer_sync(&br->multicast_router_timer);
1116         del_timer_sync(&br->multicast_querier_timer);
1117         del_timer_sync(&br->multicast_query_timer);
1118
1119         spin_lock_bh(&br->multicast_lock);
1120         mdb = br->mdb;
1121         if (!mdb)
1122                 goto out;
1123
1124         br->mdb = NULL;
1125
1126         ver = mdb->ver;
1127         for (i = 0; i < mdb->max; i++) {
1128                 hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1129                                           hlist[ver]) {
1130                         del_timer(&mp->timer);
1131                         del_timer(&mp->query_timer);
1132                         call_rcu_bh(&mp->rcu, br_multicast_free_group);
1133                 }
1134         }
1135
1136         if (mdb->old) {
1137                 spin_unlock_bh(&br->multicast_lock);
1138                 synchronize_rcu_bh();
1139                 spin_lock_bh(&br->multicast_lock);
1140                 WARN_ON(mdb->old);
1141         }
1142
1143         mdb->old = mdb;
1144         call_rcu_bh(&mdb->rcu, br_mdb_free);
1145
1146 out:
1147         spin_unlock_bh(&br->multicast_lock);
1148 }
1149
1150 int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1151 {
1152         int err = -ENOENT;
1153
1154         spin_lock_bh(&br->multicast_lock);
1155         if (!netif_running(br->dev))
1156                 goto unlock;
1157
1158         switch (val) {
1159         case 0:
1160         case 2:
1161                 del_timer(&br->multicast_router_timer);
1162                 /* fall through */
1163         case 1:
1164                 br->multicast_router = val;
1165                 err = 0;
1166                 break;
1167
1168         default:
1169                 err = -EINVAL;
1170                 break;
1171         }
1172
1173 unlock:
1174         spin_unlock_bh(&br->multicast_lock);
1175
1176         return err;
1177 }
1178
1179 int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1180 {
1181         struct net_bridge *br = p->br;
1182         int err = -ENOENT;
1183
1184         spin_lock(&br->multicast_lock);
1185         if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1186                 goto unlock;
1187
1188         switch (val) {
1189         case 0:
1190         case 1:
1191         case 2:
1192                 p->multicast_router = val;
1193                 err = 0;
1194
1195                 if (val < 2 && !hlist_unhashed(&p->rlist))
1196                         hlist_del_init_rcu(&p->rlist);
1197
1198                 if (val == 1)
1199                         break;
1200
1201                 del_timer(&p->multicast_router_timer);
1202
1203                 if (val == 0)
1204                         break;
1205
1206                 br_multicast_add_router(br, p);
1207                 break;
1208
1209         default:
1210                 err = -EINVAL;
1211                 break;
1212         }
1213
1214 unlock:
1215         spin_unlock(&br->multicast_lock);
1216
1217         return err;
1218 }
1219
1220 int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1221 {
1222         struct net_bridge_port *port;
1223         int err = -ENOENT;
1224
1225         spin_lock(&br->multicast_lock);
1226         if (!netif_running(br->dev))
1227                 goto unlock;
1228
1229         err = 0;
1230         if (br->multicast_disabled == !val)
1231                 goto unlock;
1232
1233         br->multicast_disabled = !val;
1234         if (br->multicast_disabled)
1235                 goto unlock;
1236
1237         if (br->mdb) {
1238                 if (br->mdb->old) {
1239                         err = -EEXIST;
1240 rollback:
1241                         br->multicast_disabled = !!val;
1242                         goto unlock;
1243                 }
1244
1245                 err = br_mdb_rehash(&br->mdb, br->mdb->max,
1246                                     br->hash_elasticity);
1247                 if (err)
1248                         goto rollback;
1249         }
1250
1251         br_multicast_open(br);
1252         list_for_each_entry(port, &br->port_list, list) {
1253                 if (port->state == BR_STATE_DISABLED ||
1254                     port->state == BR_STATE_BLOCKING)
1255                         continue;
1256
1257                 __br_multicast_enable_port(port);
1258         }
1259
1260 unlock:
1261         spin_unlock(&br->multicast_lock);
1262
1263         return err;
1264 }
1265
1266 int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1267 {
1268         int err = -ENOENT;
1269         u32 old;
1270
1271         spin_lock(&br->multicast_lock);
1272         if (!netif_running(br->dev))
1273                 goto unlock;
1274
1275         err = -EINVAL;
1276         if (!is_power_of_2(val))
1277                 goto unlock;
1278         if (br->mdb && val < br->mdb->size)
1279                 goto unlock;
1280
1281         err = 0;
1282
1283         old = br->hash_max;
1284         br->hash_max = val;
1285
1286         if (br->mdb) {
1287                 if (br->mdb->old) {
1288                         err = -EEXIST;
1289 rollback:
1290                         br->hash_max = old;
1291                         goto unlock;
1292                 }
1293
1294                 err = br_mdb_rehash(&br->mdb, br->hash_max,
1295                                     br->hash_elasticity);
1296                 if (err)
1297                         goto rollback;
1298         }
1299
1300 unlock:
1301         spin_unlock(&br->multicast_lock);
1302
1303         return err;
1304 }