linux/net/bridge/br_multicast.c
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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#if IS_ENABLED(CONFIG_IPV6)
  28#include <net/ipv6.h>
  29#include <net/mld.h>
  30#include <net/addrconf.h>
  31#include <net/ip6_checksum.h>
  32#endif
  33
  34#include "br_private.h"
  35
  36#define mlock_dereference(X, br) \
  37        rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))
  38
  39#if IS_ENABLED(CONFIG_IPV6)
  40static inline int ipv6_is_transient_multicast(const struct in6_addr *addr)
  41{
  42        if (ipv6_addr_is_multicast(addr) && IPV6_ADDR_MC_FLAG_TRANSIENT(addr))
  43                return 1;
  44        return 0;
  45}
  46#endif
  47
  48static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
  49{
  50        if (a->proto != b->proto)
  51                return 0;
  52        switch (a->proto) {
  53        case htons(ETH_P_IP):
  54                return a->u.ip4 == b->u.ip4;
  55#if IS_ENABLED(CONFIG_IPV6)
  56        case htons(ETH_P_IPV6):
  57                return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
  58#endif
  59        }
  60        return 0;
  61}
  62
  63static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
  64{
  65        return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);
  66}
  67
  68#if IS_ENABLED(CONFIG_IPV6)
  69static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
  70                                const struct in6_addr *ip)
  71{
  72        return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
  73}
  74#endif
  75
  76static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
  77                             struct br_ip *ip)
  78{
  79        switch (ip->proto) {
  80        case htons(ETH_P_IP):
  81                return __br_ip4_hash(mdb, ip->u.ip4);
  82#if IS_ENABLED(CONFIG_IPV6)
  83        case htons(ETH_P_IPV6):
  84                return __br_ip6_hash(mdb, &ip->u.ip6);
  85#endif
  86        }
  87        return 0;
  88}
  89
  90static struct net_bridge_mdb_entry *__br_mdb_ip_get(
  91        struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
  92{
  93        struct net_bridge_mdb_entry *mp;
  94        struct hlist_node *p;
  95
  96        hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
  97                if (br_ip_equal(&mp->addr, dst))
  98                        return mp;
  99        }
 100
 101        return NULL;
 102}
 103
 104static struct net_bridge_mdb_entry *br_mdb_ip_get(
 105        struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
 106{
 107        if (!mdb)
 108                return NULL;
 109
 110        return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
 111}
 112
 113static struct net_bridge_mdb_entry *br_mdb_ip4_get(
 114        struct net_bridge_mdb_htable *mdb, __be32 dst)
 115{
 116        struct br_ip br_dst;
 117
 118        br_dst.u.ip4 = dst;
 119        br_dst.proto = htons(ETH_P_IP);
 120
 121        return br_mdb_ip_get(mdb, &br_dst);
 122}
 123
 124#if IS_ENABLED(CONFIG_IPV6)
 125static struct net_bridge_mdb_entry *br_mdb_ip6_get(
 126        struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
 127{
 128        struct br_ip br_dst;
 129
 130        br_dst.u.ip6 = *dst;
 131        br_dst.proto = htons(ETH_P_IPV6);
 132
 133        return br_mdb_ip_get(mdb, &br_dst);
 134}
 135#endif
 136
 137struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
 138                                        struct sk_buff *skb)
 139{
 140        struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);
 141        struct br_ip ip;
 142
 143        if (br->multicast_disabled)
 144                return NULL;
 145
 146        if (BR_INPUT_SKB_CB(skb)->igmp)
 147                return NULL;
 148
 149        ip.proto = skb->protocol;
 150
 151        switch (skb->protocol) {
 152        case htons(ETH_P_IP):
 153                ip.u.ip4 = ip_hdr(skb)->daddr;
 154                break;
 155#if IS_ENABLED(CONFIG_IPV6)
 156        case htons(ETH_P_IPV6):
 157                ip.u.ip6 = ipv6_hdr(skb)->daddr;
 158                break;
 159#endif
 160        default:
 161                return NULL;
 162        }
 163
 164        return br_mdb_ip_get(mdb, &ip);
 165}
 166
 167static void br_mdb_free(struct rcu_head *head)
 168{
 169        struct net_bridge_mdb_htable *mdb =
 170                container_of(head, struct net_bridge_mdb_htable, rcu);
 171        struct net_bridge_mdb_htable *old = mdb->old;
 172
 173        mdb->old = NULL;
 174        kfree(old->mhash);
 175        kfree(old);
 176}
 177
 178static int br_mdb_copy(struct net_bridge_mdb_htable *new,
 179                       struct net_bridge_mdb_htable *old,
 180                       int elasticity)
 181{
 182        struct net_bridge_mdb_entry *mp;
 183        struct hlist_node *p;
 184        int maxlen;
 185        int len;
 186        int i;
 187
 188        for (i = 0; i < old->max; i++)
 189                hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
 190                        hlist_add_head(&mp->hlist[new->ver],
 191                                       &new->mhash[br_ip_hash(new, &mp->addr)]);
 192
 193        if (!elasticity)
 194                return 0;
 195
 196        maxlen = 0;
 197        for (i = 0; i < new->max; i++) {
 198                len = 0;
 199                hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
 200                        len++;
 201                if (len > maxlen)
 202                        maxlen = len;
 203        }
 204
 205        return maxlen > elasticity ? -EINVAL : 0;
 206}
 207
 208static void br_multicast_free_pg(struct rcu_head *head)
 209{
 210        struct net_bridge_port_group *p =
 211                container_of(head, struct net_bridge_port_group, rcu);
 212
 213        kfree(p);
 214}
 215
 216static void br_multicast_free_group(struct rcu_head *head)
 217{
 218        struct net_bridge_mdb_entry *mp =
 219                container_of(head, struct net_bridge_mdb_entry, rcu);
 220
 221        kfree(mp);
 222}
 223
 224static void br_multicast_group_expired(unsigned long data)
 225{
 226        struct net_bridge_mdb_entry *mp = (void *)data;
 227        struct net_bridge *br = mp->br;
 228        struct net_bridge_mdb_htable *mdb;
 229
 230        spin_lock(&br->multicast_lock);
 231        if (!netif_running(br->dev) || timer_pending(&mp->timer))
 232                goto out;
 233
 234        mp->mglist = false;
 235
 236        if (mp->ports)
 237                goto out;
 238
 239        mdb = mlock_dereference(br->mdb, br);
 240
 241        hlist_del_rcu(&mp->hlist[mdb->ver]);
 242        mdb->size--;
 243
 244        del_timer(&mp->query_timer);
 245        call_rcu_bh(&mp->rcu, br_multicast_free_group);
 246
 247out:
 248        spin_unlock(&br->multicast_lock);
 249}
 250
 251static void br_multicast_del_pg(struct net_bridge *br,
 252                                struct net_bridge_port_group *pg)
 253{
 254        struct net_bridge_mdb_htable *mdb;
 255        struct net_bridge_mdb_entry *mp;
 256        struct net_bridge_port_group *p;
 257        struct net_bridge_port_group __rcu **pp;
 258
 259        mdb = mlock_dereference(br->mdb, br);
 260
 261        mp = br_mdb_ip_get(mdb, &pg->addr);
 262        if (WARN_ON(!mp))
 263                return;
 264
 265        for (pp = &mp->ports;
 266             (p = mlock_dereference(*pp, br)) != NULL;
 267             pp = &p->next) {
 268                if (p != pg)
 269                        continue;
 270
 271                rcu_assign_pointer(*pp, p->next);
 272                hlist_del_init(&p->mglist);
 273                del_timer(&p->timer);
 274                del_timer(&p->query_timer);
 275                call_rcu_bh(&p->rcu, br_multicast_free_pg);
 276
 277                if (!mp->ports && !mp->mglist &&
 278                    netif_running(br->dev))
 279                        mod_timer(&mp->timer, jiffies);
 280
 281                return;
 282        }
 283
 284        WARN_ON(1);
 285}
 286
 287static void br_multicast_port_group_expired(unsigned long data)
 288{
 289        struct net_bridge_port_group *pg = (void *)data;
 290        struct net_bridge *br = pg->port->br;
 291
 292        spin_lock(&br->multicast_lock);
 293        if (!netif_running(br->dev) || timer_pending(&pg->timer) ||
 294            hlist_unhashed(&pg->mglist))
 295                goto out;
 296
 297        br_multicast_del_pg(br, pg);
 298
 299out:
 300        spin_unlock(&br->multicast_lock);
 301}
 302
 303static int br_mdb_rehash(struct net_bridge_mdb_htable __rcu **mdbp, int max,
 304                         int elasticity)
 305{
 306        struct net_bridge_mdb_htable *old = rcu_dereference_protected(*mdbp, 1);
 307        struct net_bridge_mdb_htable *mdb;
 308        int err;
 309
 310        mdb = kmalloc(sizeof(*mdb), GFP_ATOMIC);
 311        if (!mdb)
 312                return -ENOMEM;
 313
 314        mdb->max = max;
 315        mdb->old = old;
 316
 317        mdb->mhash = kzalloc(max * sizeof(*mdb->mhash), GFP_ATOMIC);
 318        if (!mdb->mhash) {
 319                kfree(mdb);
 320                return -ENOMEM;
 321        }
 322
 323        mdb->size = old ? old->size : 0;
 324        mdb->ver = old ? old->ver ^ 1 : 0;
 325
 326        if (!old || elasticity)
 327                get_random_bytes(&mdb->secret, sizeof(mdb->secret));
 328        else
 329                mdb->secret = old->secret;
 330
 331        if (!old)
 332                goto out;
 333
 334        err = br_mdb_copy(mdb, old, elasticity);
 335        if (err) {
 336                kfree(mdb->mhash);
 337                kfree(mdb);
 338                return err;
 339        }
 340
 341        call_rcu_bh(&mdb->rcu, br_mdb_free);
 342
 343out:
 344        rcu_assign_pointer(*mdbp, mdb);
 345
 346        return 0;
 347}
 348
 349static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
 350                                                    __be32 group)
 351{
 352        struct sk_buff *skb;
 353        struct igmphdr *ih;
 354        struct ethhdr *eth;
 355        struct iphdr *iph;
 356
 357        skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
 358                                                 sizeof(*ih) + 4);
 359        if (!skb)
 360                goto out;
 361
 362        skb->protocol = htons(ETH_P_IP);
 363
 364        skb_reset_mac_header(skb);
 365        eth = eth_hdr(skb);
 366
 367        memcpy(eth->h_source, br->dev->dev_addr, 6);
 368        eth->h_dest[0] = 1;
 369        eth->h_dest[1] = 0;
 370        eth->h_dest[2] = 0x5e;
 371        eth->h_dest[3] = 0;
 372        eth->h_dest[4] = 0;
 373        eth->h_dest[5] = 1;
 374        eth->h_proto = htons(ETH_P_IP);
 375        skb_put(skb, sizeof(*eth));
 376
 377        skb_set_network_header(skb, skb->len);
 378        iph = ip_hdr(skb);
 379
 380        iph->version = 4;
 381        iph->ihl = 6;
 382        iph->tos = 0xc0;
 383        iph->tot_len = htons(sizeof(*iph) + sizeof(*ih) + 4);
 384        iph->id = 0;
 385        iph->frag_off = htons(IP_DF);
 386        iph->ttl = 1;
 387        iph->protocol = IPPROTO_IGMP;
 388        iph->saddr = 0;
 389        iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
 390        ((u8 *)&iph[1])[0] = IPOPT_RA;
 391        ((u8 *)&iph[1])[1] = 4;
 392        ((u8 *)&iph[1])[2] = 0;
 393        ((u8 *)&iph[1])[3] = 0;
 394        ip_send_check(iph);
 395        skb_put(skb, 24);
 396
 397        skb_set_transport_header(skb, skb->len);
 398        ih = igmp_hdr(skb);
 399        ih->type = IGMP_HOST_MEMBERSHIP_QUERY;
 400        ih->code = (group ? br->multicast_last_member_interval :
 401                            br->multicast_query_response_interval) /
 402                   (HZ / IGMP_TIMER_SCALE);
 403        ih->group = group;
 404        ih->csum = 0;
 405        ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
 406        skb_put(skb, sizeof(*ih));
 407
 408        __skb_pull(skb, sizeof(*eth));
 409
 410out:
 411        return skb;
 412}
 413
 414#if IS_ENABLED(CONFIG_IPV6)
 415static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
 416                                                    const struct in6_addr *group)
 417{
 418        struct sk_buff *skb;
 419        struct ipv6hdr *ip6h;
 420        struct mld_msg *mldq;
 421        struct ethhdr *eth;
 422        u8 *hopopt;
 423        unsigned long interval;
 424
 425        skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
 426                                                 8 + sizeof(*mldq));
 427        if (!skb)
 428                goto out;
 429
 430        skb->protocol = htons(ETH_P_IPV6);
 431
 432        /* Ethernet header */
 433        skb_reset_mac_header(skb);
 434        eth = eth_hdr(skb);
 435
 436        memcpy(eth->h_source, br->dev->dev_addr, 6);
 437        eth->h_proto = htons(ETH_P_IPV6);
 438        skb_put(skb, sizeof(*eth));
 439
 440        /* IPv6 header + HbH option */
 441        skb_set_network_header(skb, skb->len);
 442        ip6h = ipv6_hdr(skb);
 443
 444        *(__force __be32 *)ip6h = htonl(0x60000000);
 445        ip6h->payload_len = htons(8 + sizeof(*mldq));
 446        ip6h->nexthdr = IPPROTO_HOPOPTS;
 447        ip6h->hop_limit = 1;
 448        ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
 449        if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
 450                               &ip6h->saddr)) {
 451                kfree_skb(skb);
 452                return NULL;
 453        }
 454        ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);
 455
 456        hopopt = (u8 *)(ip6h + 1);
 457        hopopt[0] = IPPROTO_ICMPV6;             /* next hdr */
 458        hopopt[1] = 0;                          /* length of HbH */
 459        hopopt[2] = IPV6_TLV_ROUTERALERT;       /* Router Alert */
 460        hopopt[3] = 2;                          /* Length of RA Option */
 461        hopopt[4] = 0;                          /* Type = 0x0000 (MLD) */
 462        hopopt[5] = 0;
 463        hopopt[6] = IPV6_TLV_PAD0;              /* Pad0 */
 464        hopopt[7] = IPV6_TLV_PAD0;              /* Pad0 */
 465
 466        skb_put(skb, sizeof(*ip6h) + 8);
 467
 468        /* ICMPv6 */
 469        skb_set_transport_header(skb, skb->len);
 470        mldq = (struct mld_msg *) icmp6_hdr(skb);
 471
 472        interval = ipv6_addr_any(group) ? br->multicast_last_member_interval :
 473                                          br->multicast_query_response_interval;
 474
 475        mldq->mld_type = ICMPV6_MGM_QUERY;
 476        mldq->mld_code = 0;
 477        mldq->mld_cksum = 0;
 478        mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
 479        mldq->mld_reserved = 0;
 480        mldq->mld_mca = *group;
 481
 482        /* checksum */
 483        mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
 484                                          sizeof(*mldq), IPPROTO_ICMPV6,
 485                                          csum_partial(mldq,
 486                                                       sizeof(*mldq), 0));
 487        skb_put(skb, sizeof(*mldq));
 488
 489        __skb_pull(skb, sizeof(*eth));
 490
 491out:
 492        return skb;
 493}
 494#endif
 495
 496static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
 497                                                struct br_ip *addr)
 498{
 499        switch (addr->proto) {
 500        case htons(ETH_P_IP):
 501                return br_ip4_multicast_alloc_query(br, addr->u.ip4);
 502#if IS_ENABLED(CONFIG_IPV6)
 503        case htons(ETH_P_IPV6):
 504                return br_ip6_multicast_alloc_query(br, &addr->u.ip6);
 505#endif
 506        }
 507        return NULL;
 508}
 509
 510static void br_multicast_send_group_query(struct net_bridge_mdb_entry *mp)
 511{
 512        struct net_bridge *br = mp->br;
 513        struct sk_buff *skb;
 514
 515        skb = br_multicast_alloc_query(br, &mp->addr);
 516        if (!skb)
 517                goto timer;
 518
 519        netif_rx(skb);
 520
 521timer:
 522        if (++mp->queries_sent < br->multicast_last_member_count)
 523                mod_timer(&mp->query_timer,
 524                          jiffies + br->multicast_last_member_interval);
 525}
 526
 527static void br_multicast_group_query_expired(unsigned long data)
 528{
 529        struct net_bridge_mdb_entry *mp = (void *)data;
 530        struct net_bridge *br = mp->br;
 531
 532        spin_lock(&br->multicast_lock);
 533        if (!netif_running(br->dev) || !mp->mglist ||
 534            mp->queries_sent >= br->multicast_last_member_count)
 535                goto out;
 536
 537        br_multicast_send_group_query(mp);
 538
 539out:
 540        spin_unlock(&br->multicast_lock);
 541}
 542
 543static void br_multicast_send_port_group_query(struct net_bridge_port_group *pg)
 544{
 545        struct net_bridge_port *port = pg->port;
 546        struct net_bridge *br = port->br;
 547        struct sk_buff *skb;
 548
 549        skb = br_multicast_alloc_query(br, &pg->addr);
 550        if (!skb)
 551                goto timer;
 552
 553        br_deliver(port, skb);
 554
 555timer:
 556        if (++pg->queries_sent < br->multicast_last_member_count)
 557                mod_timer(&pg->query_timer,
 558                          jiffies + br->multicast_last_member_interval);
 559}
 560
 561static void br_multicast_port_group_query_expired(unsigned long data)
 562{
 563        struct net_bridge_port_group *pg = (void *)data;
 564        struct net_bridge_port *port = pg->port;
 565        struct net_bridge *br = port->br;
 566
 567        spin_lock(&br->multicast_lock);
 568        if (!netif_running(br->dev) || hlist_unhashed(&pg->mglist) ||
 569            pg->queries_sent >= br->multicast_last_member_count)
 570                goto out;
 571
 572        br_multicast_send_port_group_query(pg);
 573
 574out:
 575        spin_unlock(&br->multicast_lock);
 576}
 577
 578static struct net_bridge_mdb_entry *br_multicast_get_group(
 579        struct net_bridge *br, struct net_bridge_port *port,
 580        struct br_ip *group, int hash)
 581{
 582        struct net_bridge_mdb_htable *mdb;
 583        struct net_bridge_mdb_entry *mp;
 584        struct hlist_node *p;
 585        unsigned count = 0;
 586        unsigned max;
 587        int elasticity;
 588        int err;
 589
 590        mdb = rcu_dereference_protected(br->mdb, 1);
 591        hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
 592                count++;
 593                if (unlikely(br_ip_equal(group, &mp->addr)))
 594                        return mp;
 595        }
 596
 597        elasticity = 0;
 598        max = mdb->max;
 599
 600        if (unlikely(count > br->hash_elasticity && count)) {
 601                if (net_ratelimit())
 602                        br_info(br, "Multicast hash table "
 603                                "chain limit reached: %s\n",
 604                                port ? port->dev->name : br->dev->name);
 605
 606                elasticity = br->hash_elasticity;
 607        }
 608
 609        if (mdb->size >= max) {
 610                max *= 2;
 611                if (unlikely(max >= br->hash_max)) {
 612                        br_warn(br, "Multicast hash table maximum "
 613                                "reached, disabling snooping: %s, %d\n",
 614                                port ? port->dev->name : br->dev->name, max);
 615                        err = -E2BIG;
 616disable:
 617                        br->multicast_disabled = 1;
 618                        goto err;
 619                }
 620        }
 621
 622        if (max > mdb->max || elasticity) {
 623                if (mdb->old) {
 624                        if (net_ratelimit())
 625                                br_info(br, "Multicast hash table "
 626                                        "on fire: %s\n",
 627                                        port ? port->dev->name : br->dev->name);
 628                        err = -EEXIST;
 629                        goto err;
 630                }
 631
 632                err = br_mdb_rehash(&br->mdb, max, elasticity);
 633                if (err) {
 634                        br_warn(br, "Cannot rehash multicast "
 635                                "hash table, disabling snooping: %s, %d, %d\n",
 636                                port ? port->dev->name : br->dev->name,
 637                                mdb->size, err);
 638                        goto disable;
 639                }
 640
 641                err = -EAGAIN;
 642                goto err;
 643        }
 644
 645        return NULL;
 646
 647err:
 648        mp = ERR_PTR(err);
 649        return mp;
 650}
 651
 652static struct net_bridge_mdb_entry *br_multicast_new_group(
 653        struct net_bridge *br, struct net_bridge_port *port,
 654        struct br_ip *group)
 655{
 656        struct net_bridge_mdb_htable *mdb;
 657        struct net_bridge_mdb_entry *mp;
 658        int hash;
 659        int err;
 660
 661        mdb = rcu_dereference_protected(br->mdb, 1);
 662        if (!mdb) {
 663                err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
 664                if (err)
 665                        return ERR_PTR(err);
 666                goto rehash;
 667        }
 668
 669        hash = br_ip_hash(mdb, group);
 670        mp = br_multicast_get_group(br, port, group, hash);
 671        switch (PTR_ERR(mp)) {
 672        case 0:
 673                break;
 674
 675        case -EAGAIN:
 676rehash:
 677                mdb = rcu_dereference_protected(br->mdb, 1);
 678                hash = br_ip_hash(mdb, group);
 679                break;
 680
 681        default:
 682                goto out;
 683        }
 684
 685        mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
 686        if (unlikely(!mp))
 687                return ERR_PTR(-ENOMEM);
 688
 689        mp->br = br;
 690        mp->addr = *group;
 691        setup_timer(&mp->timer, br_multicast_group_expired,
 692                    (unsigned long)mp);
 693        setup_timer(&mp->query_timer, br_multicast_group_query_expired,
 694                    (unsigned long)mp);
 695
 696        hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
 697        mdb->size++;
 698
 699out:
 700        return mp;
 701}
 702
 703static int br_multicast_add_group(struct net_bridge *br,
 704                                  struct net_bridge_port *port,
 705                                  struct br_ip *group)
 706{
 707        struct net_bridge_mdb_entry *mp;
 708        struct net_bridge_port_group *p;
 709        struct net_bridge_port_group __rcu **pp;
 710        unsigned long now = jiffies;
 711        int err;
 712
 713        spin_lock(&br->multicast_lock);
 714        if (!netif_running(br->dev) ||
 715            (port && port->state == BR_STATE_DISABLED))
 716                goto out;
 717
 718        mp = br_multicast_new_group(br, port, group);
 719        err = PTR_ERR(mp);
 720        if (IS_ERR(mp))
 721                goto err;
 722
 723        if (!port) {
 724                mp->mglist = true;
 725                mod_timer(&mp->timer, now + br->multicast_membership_interval);
 726                goto out;
 727        }
 728
 729        for (pp = &mp->ports;
 730             (p = mlock_dereference(*pp, br)) != NULL;
 731             pp = &p->next) {
 732                if (p->port == port)
 733                        goto found;
 734                if ((unsigned long)p->port < (unsigned long)port)
 735                        break;
 736        }
 737
 738        p = kzalloc(sizeof(*p), GFP_ATOMIC);
 739        err = -ENOMEM;
 740        if (unlikely(!p))
 741                goto err;
 742
 743        p->addr = *group;
 744        p->port = port;
 745        p->next = *pp;
 746        hlist_add_head(&p->mglist, &port->mglist);
 747        setup_timer(&p->timer, br_multicast_port_group_expired,
 748                    (unsigned long)p);
 749        setup_timer(&p->query_timer, br_multicast_port_group_query_expired,
 750                    (unsigned long)p);
 751
 752        rcu_assign_pointer(*pp, p);
 753
 754found:
 755        mod_timer(&p->timer, now + br->multicast_membership_interval);
 756out:
 757        err = 0;
 758
 759err:
 760        spin_unlock(&br->multicast_lock);
 761        return err;
 762}
 763
 764static int br_ip4_multicast_add_group(struct net_bridge *br,
 765                                      struct net_bridge_port *port,
 766                                      __be32 group)
 767{
 768        struct br_ip br_group;
 769
 770        if (ipv4_is_local_multicast(group))
 771                return 0;
 772
 773        br_group.u.ip4 = group;
 774        br_group.proto = htons(ETH_P_IP);
 775
 776        return br_multicast_add_group(br, port, &br_group);
 777}
 778
 779#if IS_ENABLED(CONFIG_IPV6)
 780static int br_ip6_multicast_add_group(struct net_bridge *br,
 781                                      struct net_bridge_port *port,
 782                                      const struct in6_addr *group)
 783{
 784        struct br_ip br_group;
 785
 786        if (!ipv6_is_transient_multicast(group))
 787                return 0;
 788
 789        br_group.u.ip6 = *group;
 790        br_group.proto = htons(ETH_P_IPV6);
 791
 792        return br_multicast_add_group(br, port, &br_group);
 793}
 794#endif
 795
 796static void br_multicast_router_expired(unsigned long data)
 797{
 798        struct net_bridge_port *port = (void *)data;
 799        struct net_bridge *br = port->br;
 800
 801        spin_lock(&br->multicast_lock);
 802        if (port->multicast_router != 1 ||
 803            timer_pending(&port->multicast_router_timer) ||
 804            hlist_unhashed(&port->rlist))
 805                goto out;
 806
 807        hlist_del_init_rcu(&port->rlist);
 808
 809out:
 810        spin_unlock(&br->multicast_lock);
 811}
 812
 813static void br_multicast_local_router_expired(unsigned long data)
 814{
 815}
 816
 817static void __br_multicast_send_query(struct net_bridge *br,
 818                                      struct net_bridge_port *port,
 819                                      struct br_ip *ip)
 820{
 821        struct sk_buff *skb;
 822
 823        skb = br_multicast_alloc_query(br, ip);
 824        if (!skb)
 825                return;
 826
 827        if (port) {
 828                __skb_push(skb, sizeof(struct ethhdr));
 829                skb->dev = port->dev;
 830                NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
 831                        dev_queue_xmit);
 832        } else
 833                netif_rx(skb);
 834}
 835
 836static void br_multicast_send_query(struct net_bridge *br,
 837                                    struct net_bridge_port *port, u32 sent)
 838{
 839        unsigned long time;
 840        struct br_ip br_group;
 841
 842        if (!netif_running(br->dev) || br->multicast_disabled ||
 843            timer_pending(&br->multicast_querier_timer))
 844                return;
 845
 846        memset(&br_group.u, 0, sizeof(br_group.u));
 847
 848        br_group.proto = htons(ETH_P_IP);
 849        __br_multicast_send_query(br, port, &br_group);
 850
 851#if IS_ENABLED(CONFIG_IPV6)
 852        br_group.proto = htons(ETH_P_IPV6);
 853        __br_multicast_send_query(br, port, &br_group);
 854#endif
 855
 856        time = jiffies;
 857        time += sent < br->multicast_startup_query_count ?
 858                br->multicast_startup_query_interval :
 859                br->multicast_query_interval;
 860        mod_timer(port ? &port->multicast_query_timer :
 861                         &br->multicast_query_timer, time);
 862}
 863
 864static void br_multicast_port_query_expired(unsigned long data)
 865{
 866        struct net_bridge_port *port = (void *)data;
 867        struct net_bridge *br = port->br;
 868
 869        spin_lock(&br->multicast_lock);
 870        if (port->state == BR_STATE_DISABLED ||
 871            port->state == BR_STATE_BLOCKING)
 872                goto out;
 873
 874        if (port->multicast_startup_queries_sent <
 875            br->multicast_startup_query_count)
 876                port->multicast_startup_queries_sent++;
 877
 878        br_multicast_send_query(port->br, port,
 879                                port->multicast_startup_queries_sent);
 880
 881out:
 882        spin_unlock(&br->multicast_lock);
 883}
 884
 885void br_multicast_add_port(struct net_bridge_port *port)
 886{
 887        port->multicast_router = 1;
 888
 889        setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
 890                    (unsigned long)port);
 891        setup_timer(&port->multicast_query_timer,
 892                    br_multicast_port_query_expired, (unsigned long)port);
 893}
 894
 895void br_multicast_del_port(struct net_bridge_port *port)
 896{
 897        del_timer_sync(&port->multicast_router_timer);
 898}
 899
 900static void __br_multicast_enable_port(struct net_bridge_port *port)
 901{
 902        port->multicast_startup_queries_sent = 0;
 903
 904        if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
 905            del_timer(&port->multicast_query_timer))
 906                mod_timer(&port->multicast_query_timer, jiffies);
 907}
 908
 909void br_multicast_enable_port(struct net_bridge_port *port)
 910{
 911        struct net_bridge *br = port->br;
 912
 913        spin_lock(&br->multicast_lock);
 914        if (br->multicast_disabled || !netif_running(br->dev))
 915                goto out;
 916
 917        __br_multicast_enable_port(port);
 918
 919out:
 920        spin_unlock(&br->multicast_lock);
 921}
 922
 923void br_multicast_disable_port(struct net_bridge_port *port)
 924{
 925        struct net_bridge *br = port->br;
 926        struct net_bridge_port_group *pg;
 927        struct hlist_node *p, *n;
 928
 929        spin_lock(&br->multicast_lock);
 930        hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
 931                br_multicast_del_pg(br, pg);
 932
 933        if (!hlist_unhashed(&port->rlist))
 934                hlist_del_init_rcu(&port->rlist);
 935        del_timer(&port->multicast_router_timer);
 936        del_timer(&port->multicast_query_timer);
 937        spin_unlock(&br->multicast_lock);
 938}
 939
 940static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
 941                                         struct net_bridge_port *port,
 942                                         struct sk_buff *skb)
 943{
 944        struct igmpv3_report *ih;
 945        struct igmpv3_grec *grec;
 946        int i;
 947        int len;
 948        int num;
 949        int type;
 950        int err = 0;
 951        __be32 group;
 952
 953        if (!pskb_may_pull(skb, sizeof(*ih)))
 954                return -EINVAL;
 955
 956        ih = igmpv3_report_hdr(skb);
 957        num = ntohs(ih->ngrec);
 958        len = sizeof(*ih);
 959
 960        for (i = 0; i < num; i++) {
 961                len += sizeof(*grec);
 962                if (!pskb_may_pull(skb, len))
 963                        return -EINVAL;
 964
 965                grec = (void *)(skb->data + len - sizeof(*grec));
 966                group = grec->grec_mca;
 967                type = grec->grec_type;
 968
 969                len += ntohs(grec->grec_nsrcs) * 4;
 970                if (!pskb_may_pull(skb, len))
 971                        return -EINVAL;
 972
 973                /* We treat this as an IGMPv2 report for now. */
 974                switch (type) {
 975                case IGMPV3_MODE_IS_INCLUDE:
 976                case IGMPV3_MODE_IS_EXCLUDE:
 977                case IGMPV3_CHANGE_TO_INCLUDE:
 978                case IGMPV3_CHANGE_TO_EXCLUDE:
 979                case IGMPV3_ALLOW_NEW_SOURCES:
 980                case IGMPV3_BLOCK_OLD_SOURCES:
 981                        break;
 982
 983                default:
 984                        continue;
 985                }
 986
 987                err = br_ip4_multicast_add_group(br, port, group);
 988                if (err)
 989                        break;
 990        }
 991
 992        return err;
 993}
 994
 995#if IS_ENABLED(CONFIG_IPV6)
 996static int br_ip6_multicast_mld2_report(struct net_bridge *br,
 997                                        struct net_bridge_port *port,
 998                                        struct sk_buff *skb)
 999{
1000        struct icmp6hdr *icmp6h;
1001        struct mld2_grec *grec;
1002        int i;
1003        int len;
1004        int num;
1005        int err = 0;
1006
1007        if (!pskb_may_pull(skb, sizeof(*icmp6h)))
1008                return -EINVAL;
1009
1010        icmp6h = icmp6_hdr(skb);
1011        num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
1012        len = sizeof(*icmp6h);
1013
1014        for (i = 0; i < num; i++) {
1015                __be16 *nsrcs, _nsrcs;
1016
1017                nsrcs = skb_header_pointer(skb,
1018                                           len + offsetof(struct mld2_grec,
1019                                                          grec_nsrcs),
1020                                           sizeof(_nsrcs), &_nsrcs);
1021                if (!nsrcs)
1022                        return -EINVAL;
1023
1024                if (!pskb_may_pull(skb,
1025                                   len + sizeof(*grec) +
1026                                   sizeof(struct in6_addr) * ntohs(*nsrcs)))
1027                        return -EINVAL;
1028
1029                grec = (struct mld2_grec *)(skb->data + len);
1030                len += sizeof(*grec) +
1031                       sizeof(struct in6_addr) * ntohs(*nsrcs);
1032
1033                /* We treat these as MLDv1 reports for now. */
1034                switch (grec->grec_type) {
1035                case MLD2_MODE_IS_INCLUDE:
1036                case MLD2_MODE_IS_EXCLUDE:
1037                case MLD2_CHANGE_TO_INCLUDE:
1038                case MLD2_CHANGE_TO_EXCLUDE:
1039                case MLD2_ALLOW_NEW_SOURCES:
1040                case MLD2_BLOCK_OLD_SOURCES:
1041                        break;
1042
1043                default:
1044                        continue;
1045                }
1046
1047                err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
1048                if (!err)
1049                        break;
1050        }
1051
1052        return err;
1053}
1054#endif
1055
1056/*
1057 * Add port to rotuer_list
1058 *  list is maintained ordered by pointer value
1059 *  and locked by br->multicast_lock and RCU
1060 */
1061static void br_multicast_add_router(struct net_bridge *br,
1062                                    struct net_bridge_port *port)
1063{
1064        struct net_bridge_port *p;
1065        struct hlist_node *n, *slot = NULL;
1066
1067        hlist_for_each_entry(p, n, &br->router_list, rlist) {
1068                if ((unsigned long) port >= (unsigned long) p)
1069                        break;
1070                slot = n;
1071        }
1072
1073        if (slot)
1074                hlist_add_after_rcu(slot, &port->rlist);
1075        else
1076                hlist_add_head_rcu(&port->rlist, &br->router_list);
1077}
1078
1079static void br_multicast_mark_router(struct net_bridge *br,
1080                                     struct net_bridge_port *port)
1081{
1082        unsigned long now = jiffies;
1083
1084        if (!port) {
1085                if (br->multicast_router == 1)
1086                        mod_timer(&br->multicast_router_timer,
1087                                  now + br->multicast_querier_interval);
1088                return;
1089        }
1090
1091        if (port->multicast_router != 1)
1092                return;
1093
1094        if (!hlist_unhashed(&port->rlist))
1095                goto timer;
1096
1097        br_multicast_add_router(br, port);
1098
1099timer:
1100        mod_timer(&port->multicast_router_timer,
1101                  now + br->multicast_querier_interval);
1102}
1103
1104static void br_multicast_query_received(struct net_bridge *br,
1105                                        struct net_bridge_port *port,
1106                                        int saddr)
1107{
1108        if (saddr)
1109                mod_timer(&br->multicast_querier_timer,
1110                          jiffies + br->multicast_querier_interval);
1111        else if (timer_pending(&br->multicast_querier_timer))
1112                return;
1113
1114        br_multicast_mark_router(br, port);
1115}
1116
1117static int br_ip4_multicast_query(struct net_bridge *br,
1118                                  struct net_bridge_port *port,
1119                                  struct sk_buff *skb)
1120{
1121        const struct iphdr *iph = ip_hdr(skb);
1122        struct igmphdr *ih = igmp_hdr(skb);
1123        struct net_bridge_mdb_entry *mp;
1124        struct igmpv3_query *ih3;
1125        struct net_bridge_port_group *p;
1126        struct net_bridge_port_group __rcu **pp;
1127        unsigned long max_delay;
1128        unsigned long now = jiffies;
1129        __be32 group;
1130        int err = 0;
1131
1132        spin_lock(&br->multicast_lock);
1133        if (!netif_running(br->dev) ||
1134            (port && port->state == BR_STATE_DISABLED))
1135                goto out;
1136
1137        br_multicast_query_received(br, port, !!iph->saddr);
1138
1139        group = ih->group;
1140
1141        if (skb->len == sizeof(*ih)) {
1142                max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
1143
1144                if (!max_delay) {
1145                        max_delay = 10 * HZ;
1146                        group = 0;
1147                }
1148        } else {
1149                if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
1150                        err = -EINVAL;
1151                        goto out;
1152                }
1153
1154                ih3 = igmpv3_query_hdr(skb);
1155                if (ih3->nsrcs)
1156                        goto out;
1157
1158                max_delay = ih3->code ?
1159                            IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
1160        }
1161
1162        if (!group)
1163                goto out;
1164
1165        mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group);
1166        if (!mp)
1167                goto out;
1168
1169        max_delay *= br->multicast_last_member_count;
1170
1171        if (mp->mglist &&
1172            (timer_pending(&mp->timer) ?
1173             time_after(mp->timer.expires, now + max_delay) :
1174             try_to_del_timer_sync(&mp->timer) >= 0))
1175                mod_timer(&mp->timer, now + max_delay);
1176
1177        for (pp = &mp->ports;
1178             (p = mlock_dereference(*pp, br)) != NULL;
1179             pp = &p->next) {
1180                if (timer_pending(&p->timer) ?
1181                    time_after(p->timer.expires, now + max_delay) :
1182                    try_to_del_timer_sync(&p->timer) >= 0)
1183                        mod_timer(&p->timer, now + max_delay);
1184        }
1185
1186out:
1187        spin_unlock(&br->multicast_lock);
1188        return err;
1189}
1190
1191#if IS_ENABLED(CONFIG_IPV6)
1192static int br_ip6_multicast_query(struct net_bridge *br,
1193                                  struct net_bridge_port *port,
1194                                  struct sk_buff *skb)
1195{
1196        const struct ipv6hdr *ip6h = ipv6_hdr(skb);
1197        struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
1198        struct net_bridge_mdb_entry *mp;
1199        struct mld2_query *mld2q;
1200        struct net_bridge_port_group *p;
1201        struct net_bridge_port_group __rcu **pp;
1202        unsigned long max_delay;
1203        unsigned long now = jiffies;
1204        const struct in6_addr *group = NULL;
1205        int err = 0;
1206
1207        spin_lock(&br->multicast_lock);
1208        if (!netif_running(br->dev) ||
1209            (port && port->state == BR_STATE_DISABLED))
1210                goto out;
1211
1212        br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
1213
1214        if (skb->len == sizeof(*mld)) {
1215                if (!pskb_may_pull(skb, sizeof(*mld))) {
1216                        err = -EINVAL;
1217                        goto out;
1218                }
1219                mld = (struct mld_msg *) icmp6_hdr(skb);
1220                max_delay = msecs_to_jiffies(htons(mld->mld_maxdelay));
1221                if (max_delay)
1222                        group = &mld->mld_mca;
1223        } else if (skb->len >= sizeof(*mld2q)) {
1224                if (!pskb_may_pull(skb, sizeof(*mld2q))) {
1225                        err = -EINVAL;
1226                        goto out;
1227                }
1228                mld2q = (struct mld2_query *)icmp6_hdr(skb);
1229                if (!mld2q->mld2q_nsrcs)
1230                        group = &mld2q->mld2q_mca;
1231                max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
1232        }
1233
1234        if (!group)
1235                goto out;
1236
1237        mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group);
1238        if (!mp)
1239                goto out;
1240
1241        max_delay *= br->multicast_last_member_count;
1242        if (mp->mglist &&
1243            (timer_pending(&mp->timer) ?
1244             time_after(mp->timer.expires, now + max_delay) :
1245             try_to_del_timer_sync(&mp->timer) >= 0))
1246                mod_timer(&mp->timer, now + max_delay);
1247
1248        for (pp = &mp->ports;
1249             (p = mlock_dereference(*pp, br)) != NULL;
1250             pp = &p->next) {
1251                if (timer_pending(&p->timer) ?
1252                    time_after(p->timer.expires, now + max_delay) :
1253                    try_to_del_timer_sync(&p->timer) >= 0)
1254                        mod_timer(&p->timer, now + max_delay);
1255        }
1256
1257out:
1258        spin_unlock(&br->multicast_lock);
1259        return err;
1260}
1261#endif
1262
1263static void br_multicast_leave_group(struct net_bridge *br,
1264                                     struct net_bridge_port *port,
1265                                     struct br_ip *group)
1266{
1267        struct net_bridge_mdb_htable *mdb;
1268        struct net_bridge_mdb_entry *mp;
1269        struct net_bridge_port_group *p;
1270        unsigned long now;
1271        unsigned long time;
1272
1273        spin_lock(&br->multicast_lock);
1274        if (!netif_running(br->dev) ||
1275            (port && port->state == BR_STATE_DISABLED) ||
1276            timer_pending(&br->multicast_querier_timer))
1277                goto out;
1278
1279        mdb = mlock_dereference(br->mdb, br);
1280        mp = br_mdb_ip_get(mdb, group);
1281        if (!mp)
1282                goto out;
1283
1284        now = jiffies;
1285        time = now + br->multicast_last_member_count *
1286                     br->multicast_last_member_interval;
1287
1288        if (!port) {
1289                if (mp->mglist &&
1290                    (timer_pending(&mp->timer) ?
1291                     time_after(mp->timer.expires, time) :
1292                     try_to_del_timer_sync(&mp->timer) >= 0)) {
1293                        mod_timer(&mp->timer, time);
1294
1295                        mp->queries_sent = 0;
1296                        mod_timer(&mp->query_timer, now);
1297                }
1298
1299                goto out;
1300        }
1301
1302        for (p = mlock_dereference(mp->ports, br);
1303             p != NULL;
1304             p = mlock_dereference(p->next, br)) {
1305                if (p->port != port)
1306                        continue;
1307
1308                if (!hlist_unhashed(&p->mglist) &&
1309                    (timer_pending(&p->timer) ?
1310                     time_after(p->timer.expires, time) :
1311                     try_to_del_timer_sync(&p->timer) >= 0)) {
1312                        mod_timer(&p->timer, time);
1313
1314                        p->queries_sent = 0;
1315                        mod_timer(&p->query_timer, now);
1316                }
1317
1318                break;
1319        }
1320
1321out:
1322        spin_unlock(&br->multicast_lock);
1323}
1324
1325static void br_ip4_multicast_leave_group(struct net_bridge *br,
1326                                         struct net_bridge_port *port,
1327                                         __be32 group)
1328{
1329        struct br_ip br_group;
1330
1331        if (ipv4_is_local_multicast(group))
1332                return;
1333
1334        br_group.u.ip4 = group;
1335        br_group.proto = htons(ETH_P_IP);
1336
1337        br_multicast_leave_group(br, port, &br_group);
1338}
1339
1340#if IS_ENABLED(CONFIG_IPV6)
1341static void br_ip6_multicast_leave_group(struct net_bridge *br,
1342                                         struct net_bridge_port *port,
1343                                         const struct in6_addr *group)
1344{
1345        struct br_ip br_group;
1346
1347        if (!ipv6_is_transient_multicast(group))
1348                return;
1349
1350        br_group.u.ip6 = *group;
1351        br_group.proto = htons(ETH_P_IPV6);
1352
1353        br_multicast_leave_group(br, port, &br_group);
1354}
1355#endif
1356
1357static int br_multicast_ipv4_rcv(struct net_bridge *br,
1358                                 struct net_bridge_port *port,
1359                                 struct sk_buff *skb)
1360{
1361        struct sk_buff *skb2 = skb;
1362        const struct iphdr *iph;
1363        struct igmphdr *ih;
1364        unsigned len;
1365        unsigned offset;
1366        int err;
1367
1368        /* We treat OOM as packet loss for now. */
1369        if (!pskb_may_pull(skb, sizeof(*iph)))
1370                return -EINVAL;
1371
1372        iph = ip_hdr(skb);
1373
1374        if (iph->ihl < 5 || iph->version != 4)
1375                return -EINVAL;
1376
1377        if (!pskb_may_pull(skb, ip_hdrlen(skb)))
1378                return -EINVAL;
1379
1380        iph = ip_hdr(skb);
1381
1382        if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1383                return -EINVAL;
1384
1385        if (iph->protocol != IPPROTO_IGMP) {
1386                if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP)
1387                        BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1388                return 0;
1389        }
1390
1391        len = ntohs(iph->tot_len);
1392        if (skb->len < len || len < ip_hdrlen(skb))
1393                return -EINVAL;
1394
1395        if (skb->len > len) {
1396                skb2 = skb_clone(skb, GFP_ATOMIC);
1397                if (!skb2)
1398                        return -ENOMEM;
1399
1400                err = pskb_trim_rcsum(skb2, len);
1401                if (err)
1402                        goto err_out;
1403        }
1404
1405        len -= ip_hdrlen(skb2);
1406        offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
1407        __skb_pull(skb2, offset);
1408        skb_reset_transport_header(skb2);
1409
1410        err = -EINVAL;
1411        if (!pskb_may_pull(skb2, sizeof(*ih)))
1412                goto out;
1413
1414        switch (skb2->ip_summed) {
1415        case CHECKSUM_COMPLETE:
1416                if (!csum_fold(skb2->csum))
1417                        break;
1418                /* fall through */
1419        case CHECKSUM_NONE:
1420                skb2->csum = 0;
1421                if (skb_checksum_complete(skb2))
1422                        goto out;
1423        }
1424
1425        err = 0;
1426
1427        BR_INPUT_SKB_CB(skb)->igmp = 1;
1428        ih = igmp_hdr(skb2);
1429
1430        switch (ih->type) {
1431        case IGMP_HOST_MEMBERSHIP_REPORT:
1432        case IGMPV2_HOST_MEMBERSHIP_REPORT:
1433                BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1434                err = br_ip4_multicast_add_group(br, port, ih->group);
1435                break;
1436        case IGMPV3_HOST_MEMBERSHIP_REPORT:
1437                err = br_ip4_multicast_igmp3_report(br, port, skb2);
1438                break;
1439        case IGMP_HOST_MEMBERSHIP_QUERY:
1440                err = br_ip4_multicast_query(br, port, skb2);
1441                break;
1442        case IGMP_HOST_LEAVE_MESSAGE:
1443                br_ip4_multicast_leave_group(br, port, ih->group);
1444                break;
1445        }
1446
1447out:
1448        __skb_push(skb2, offset);
1449err_out:
1450        if (skb2 != skb)
1451                kfree_skb(skb2);
1452        return err;
1453}
1454
1455#if IS_ENABLED(CONFIG_IPV6)
1456static int br_multicast_ipv6_rcv(struct net_bridge *br,
1457                                 struct net_bridge_port *port,
1458                                 struct sk_buff *skb)
1459{
1460        struct sk_buff *skb2;
1461        const struct ipv6hdr *ip6h;
1462        u8 icmp6_type;
1463        u8 nexthdr;
1464        __be16 frag_off;
1465        unsigned len;
1466        int offset;
1467        int err;
1468
1469        if (!pskb_may_pull(skb, sizeof(*ip6h)))
1470                return -EINVAL;
1471
1472        ip6h = ipv6_hdr(skb);
1473
1474        /*
1475         * We're interested in MLD messages only.
1476         *  - Version is 6
1477         *  - MLD has always Router Alert hop-by-hop option
1478         *  - But we do not support jumbrograms.
1479         */
1480        if (ip6h->version != 6 ||
1481            ip6h->nexthdr != IPPROTO_HOPOPTS ||
1482            ip6h->payload_len == 0)
1483                return 0;
1484
1485        len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
1486        if (skb->len < len)
1487                return -EINVAL;
1488
1489        nexthdr = ip6h->nexthdr;
1490        offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
1491
1492        if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
1493                return 0;
1494
1495        /* Okay, we found ICMPv6 header */
1496        skb2 = skb_clone(skb, GFP_ATOMIC);
1497        if (!skb2)
1498                return -ENOMEM;
1499
1500        err = -EINVAL;
1501        if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
1502                goto out;
1503
1504        len -= offset - skb_network_offset(skb2);
1505
1506        __skb_pull(skb2, offset);
1507        skb_reset_transport_header(skb2);
1508        skb_postpull_rcsum(skb2, skb_network_header(skb2),
1509                           skb_network_header_len(skb2));
1510
1511        icmp6_type = icmp6_hdr(skb2)->icmp6_type;
1512
1513        switch (icmp6_type) {
1514        case ICMPV6_MGM_QUERY:
1515        case ICMPV6_MGM_REPORT:
1516        case ICMPV6_MGM_REDUCTION:
1517        case ICMPV6_MLD2_REPORT:
1518                break;
1519        default:
1520                err = 0;
1521                goto out;
1522        }
1523
1524        /* Okay, we found MLD message. Check further. */
1525        if (skb2->len > len) {
1526                err = pskb_trim_rcsum(skb2, len);
1527                if (err)
1528                        goto out;
1529                err = -EINVAL;
1530        }
1531
1532        ip6h = ipv6_hdr(skb2);
1533
1534        switch (skb2->ip_summed) {
1535        case CHECKSUM_COMPLETE:
1536                if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
1537                                        IPPROTO_ICMPV6, skb2->csum))
1538                        break;
1539                /*FALLTHROUGH*/
1540        case CHECKSUM_NONE:
1541                skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
1542                                                        &ip6h->daddr,
1543                                                        skb2->len,
1544                                                        IPPROTO_ICMPV6, 0));
1545                if (__skb_checksum_complete(skb2))
1546                        goto out;
1547        }
1548
1549        err = 0;
1550
1551        BR_INPUT_SKB_CB(skb)->igmp = 1;
1552
1553        switch (icmp6_type) {
1554        case ICMPV6_MGM_REPORT:
1555            {
1556                struct mld_msg *mld;
1557                if (!pskb_may_pull(skb2, sizeof(*mld))) {
1558                        err = -EINVAL;
1559                        goto out;
1560                }
1561                mld = (struct mld_msg *)skb_transport_header(skb2);
1562                BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1563                err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
1564                break;
1565            }
1566        case ICMPV6_MLD2_REPORT:
1567                err = br_ip6_multicast_mld2_report(br, port, skb2);
1568                break;
1569        case ICMPV6_MGM_QUERY:
1570                err = br_ip6_multicast_query(br, port, skb2);
1571                break;
1572        case ICMPV6_MGM_REDUCTION:
1573            {
1574                struct mld_msg *mld;
1575                if (!pskb_may_pull(skb2, sizeof(*mld))) {
1576                        err = -EINVAL;
1577                        goto out;
1578                }
1579                mld = (struct mld_msg *)skb_transport_header(skb2);
1580                br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
1581            }
1582        }
1583
1584out:
1585        kfree_skb(skb2);
1586        return err;
1587}
1588#endif
1589
1590int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1591                     struct sk_buff *skb)
1592{
1593        BR_INPUT_SKB_CB(skb)->igmp = 0;
1594        BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
1595
1596        if (br->multicast_disabled)
1597                return 0;
1598
1599        switch (skb->protocol) {
1600        case htons(ETH_P_IP):
1601                return br_multicast_ipv4_rcv(br, port, skb);
1602#if IS_ENABLED(CONFIG_IPV6)
1603        case htons(ETH_P_IPV6):
1604                return br_multicast_ipv6_rcv(br, port, skb);
1605#endif
1606        }
1607
1608        return 0;
1609}
1610
1611static void br_multicast_query_expired(unsigned long data)
1612{
1613        struct net_bridge *br = (void *)data;
1614
1615        spin_lock(&br->multicast_lock);
1616        if (br->multicast_startup_queries_sent <
1617            br->multicast_startup_query_count)
1618                br->multicast_startup_queries_sent++;
1619
1620        br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1621
1622        spin_unlock(&br->multicast_lock);
1623}
1624
1625void br_multicast_init(struct net_bridge *br)
1626{
1627        br->hash_elasticity = 4;
1628        br->hash_max = 512;
1629
1630        br->multicast_router = 1;
1631        br->multicast_last_member_count = 2;
1632        br->multicast_startup_query_count = 2;
1633
1634        br->multicast_last_member_interval = HZ;
1635        br->multicast_query_response_interval = 10 * HZ;
1636        br->multicast_startup_query_interval = 125 * HZ / 4;
1637        br->multicast_query_interval = 125 * HZ;
1638        br->multicast_querier_interval = 255 * HZ;
1639        br->multicast_membership_interval = 260 * HZ;
1640
1641        spin_lock_init(&br->multicast_lock);
1642        setup_timer(&br->multicast_router_timer,
1643                    br_multicast_local_router_expired, 0);
1644        setup_timer(&br->multicast_querier_timer,
1645                    br_multicast_local_router_expired, 0);
1646        setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1647                    (unsigned long)br);
1648}
1649
1650void br_multicast_open(struct net_bridge *br)
1651{
1652        br->multicast_startup_queries_sent = 0;
1653
1654        if (br->multicast_disabled)
1655                return;
1656
1657        mod_timer(&br->multicast_query_timer, jiffies);
1658}
1659
1660void br_multicast_stop(struct net_bridge *br)
1661{
1662        struct net_bridge_mdb_htable *mdb;
1663        struct net_bridge_mdb_entry *mp;
1664        struct hlist_node *p, *n;
1665        u32 ver;
1666        int i;
1667
1668        del_timer_sync(&br->multicast_router_timer);
1669        del_timer_sync(&br->multicast_querier_timer);
1670        del_timer_sync(&br->multicast_query_timer);
1671
1672        spin_lock_bh(&br->multicast_lock);
1673        mdb = mlock_dereference(br->mdb, br);
1674        if (!mdb)
1675                goto out;
1676
1677        br->mdb = NULL;
1678
1679        ver = mdb->ver;
1680        for (i = 0; i < mdb->max; i++) {
1681                hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1682                                          hlist[ver]) {
1683                        del_timer(&mp->timer);
1684                        del_timer(&mp->query_timer);
1685                        call_rcu_bh(&mp->rcu, br_multicast_free_group);
1686                }
1687        }
1688
1689        if (mdb->old) {
1690                spin_unlock_bh(&br->multicast_lock);
1691                rcu_barrier_bh();
1692                spin_lock_bh(&br->multicast_lock);
1693                WARN_ON(mdb->old);
1694        }
1695
1696        mdb->old = mdb;
1697        call_rcu_bh(&mdb->rcu, br_mdb_free);
1698
1699out:
1700        spin_unlock_bh(&br->multicast_lock);
1701}
1702
1703int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1704{
1705        int err = -ENOENT;
1706
1707        spin_lock_bh(&br->multicast_lock);
1708        if (!netif_running(br->dev))
1709                goto unlock;
1710
1711        switch (val) {
1712        case 0:
1713        case 2:
1714                del_timer(&br->multicast_router_timer);
1715                /* fall through */
1716        case 1:
1717                br->multicast_router = val;
1718                err = 0;
1719                break;
1720
1721        default:
1722                err = -EINVAL;
1723                break;
1724        }
1725
1726unlock:
1727        spin_unlock_bh(&br->multicast_lock);
1728
1729        return err;
1730}
1731
1732int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1733{
1734        struct net_bridge *br = p->br;
1735        int err = -ENOENT;
1736
1737        spin_lock(&br->multicast_lock);
1738        if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1739                goto unlock;
1740
1741        switch (val) {
1742        case 0:
1743        case 1:
1744        case 2:
1745                p->multicast_router = val;
1746                err = 0;
1747
1748                if (val < 2 && !hlist_unhashed(&p->rlist))
1749                        hlist_del_init_rcu(&p->rlist);
1750
1751                if (val == 1)
1752                        break;
1753
1754                del_timer(&p->multicast_router_timer);
1755
1756                if (val == 0)
1757                        break;
1758
1759                br_multicast_add_router(br, p);
1760                break;
1761
1762        default:
1763                err = -EINVAL;
1764                break;
1765        }
1766
1767unlock:
1768        spin_unlock(&br->multicast_lock);
1769
1770        return err;
1771}
1772
1773int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1774{
1775        struct net_bridge_port *port;
1776        int err = 0;
1777        struct net_bridge_mdb_htable *mdb;
1778
1779        spin_lock_bh(&br->multicast_lock);
1780        if (br->multicast_disabled == !val)
1781                goto unlock;
1782
1783        br->multicast_disabled = !val;
1784        if (br->multicast_disabled)
1785                goto unlock;
1786
1787        if (!netif_running(br->dev))
1788                goto unlock;
1789
1790        mdb = mlock_dereference(br->mdb, br);
1791        if (mdb) {
1792                if (mdb->old) {
1793                        err = -EEXIST;
1794rollback:
1795                        br->multicast_disabled = !!val;
1796                        goto unlock;
1797                }
1798
1799                err = br_mdb_rehash(&br->mdb, mdb->max,
1800                                    br->hash_elasticity);
1801                if (err)
1802                        goto rollback;
1803        }
1804
1805        br_multicast_open(br);
1806        list_for_each_entry(port, &br->port_list, list) {
1807                if (port->state == BR_STATE_DISABLED ||
1808                    port->state == BR_STATE_BLOCKING)
1809                        continue;
1810
1811                __br_multicast_enable_port(port);
1812        }
1813
1814unlock:
1815        spin_unlock_bh(&br->multicast_lock);
1816
1817        return err;
1818}
1819
1820int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1821{
1822        int err = -ENOENT;
1823        u32 old;
1824        struct net_bridge_mdb_htable *mdb;
1825
1826        spin_lock(&br->multicast_lock);
1827        if (!netif_running(br->dev))
1828                goto unlock;
1829
1830        err = -EINVAL;
1831        if (!is_power_of_2(val))
1832                goto unlock;
1833
1834        mdb = mlock_dereference(br->mdb, br);
1835        if (mdb && val < mdb->size)
1836                goto unlock;
1837
1838        err = 0;
1839
1840        old = br->hash_max;
1841        br->hash_max = val;
1842
1843        if (mdb) {
1844                if (mdb->old) {
1845                        err = -EEXIST;
1846rollback:
1847                        br->hash_max = old;
1848                        goto unlock;
1849                }
1850
1851                err = br_mdb_rehash(&br->mdb, br->hash_max,
1852                                    br->hash_elasticity);
1853                if (err)
1854                        goto rollback;
1855        }
1856
1857unlock:
1858        spin_unlock(&br->multicast_lock);
1859
1860        return err;
1861}
1862