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
  39static void br_multicast_start_querier(struct net_bridge *br);
  40
  41#if IS_ENABLED(CONFIG_IPV6)
  42static inline int ipv6_is_transient_multicast(const struct in6_addr *addr)
  43{
  44        if (ipv6_addr_is_multicast(addr) && IPV6_ADDR_MC_FLAG_TRANSIENT(addr))
  45                return 1;
  46        return 0;
  47}
  48#endif
  49
  50static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
  51{
  52        if (a->proto != b->proto)
  53                return 0;
  54        switch (a->proto) {
  55        case htons(ETH_P_IP):
  56                return a->u.ip4 == b->u.ip4;
  57#if IS_ENABLED(CONFIG_IPV6)
  58        case htons(ETH_P_IPV6):
  59                return ipv6_addr_equal(&a->u.ip6, &b->u.ip6);
  60#endif
  61        }
  62        return 0;
  63}
  64
  65static inline int __br_ip4_hash(struct net_bridge_mdb_htable *mdb, __be32 ip)
  66{
  67        return jhash_1word(mdb->secret, (__force u32)ip) & (mdb->max - 1);
  68}
  69
  70#if IS_ENABLED(CONFIG_IPV6)
  71static inline int __br_ip6_hash(struct net_bridge_mdb_htable *mdb,
  72                                const struct in6_addr *ip)
  73{
  74        return jhash2((__force u32 *)ip->s6_addr32, 4, mdb->secret) & (mdb->max - 1);
  75}
  76#endif
  77
  78static inline int br_ip_hash(struct net_bridge_mdb_htable *mdb,
  79                             struct br_ip *ip)
  80{
  81        switch (ip->proto) {
  82        case htons(ETH_P_IP):
  83                return __br_ip4_hash(mdb, ip->u.ip4);
  84#if IS_ENABLED(CONFIG_IPV6)
  85        case htons(ETH_P_IPV6):
  86                return __br_ip6_hash(mdb, &ip->u.ip6);
  87#endif
  88        }
  89        return 0;
  90}
  91
  92static struct net_bridge_mdb_entry *__br_mdb_ip_get(
  93        struct net_bridge_mdb_htable *mdb, struct br_ip *dst, int hash)
  94{
  95        struct net_bridge_mdb_entry *mp;
  96        struct hlist_node *p;
  97
  98        hlist_for_each_entry_rcu(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
  99                if (br_ip_equal(&mp->addr, dst))
 100                        return mp;
 101        }
 102
 103        return NULL;
 104}
 105
 106static struct net_bridge_mdb_entry *br_mdb_ip_get(
 107        struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
 108{
 109        if (!mdb)
 110                return NULL;
 111
 112        return __br_mdb_ip_get(mdb, dst, br_ip_hash(mdb, dst));
 113}
 114
 115static struct net_bridge_mdb_entry *br_mdb_ip4_get(
 116        struct net_bridge_mdb_htable *mdb, __be32 dst)
 117{
 118        struct br_ip br_dst;
 119
 120        br_dst.u.ip4 = dst;
 121        br_dst.proto = htons(ETH_P_IP);
 122
 123        return br_mdb_ip_get(mdb, &br_dst);
 124}
 125
 126#if IS_ENABLED(CONFIG_IPV6)
 127static struct net_bridge_mdb_entry *br_mdb_ip6_get(
 128        struct net_bridge_mdb_htable *mdb, const struct in6_addr *dst)
 129{
 130        struct br_ip br_dst;
 131
 132        br_dst.u.ip6 = *dst;
 133        br_dst.proto = htons(ETH_P_IPV6);
 134
 135        return br_mdb_ip_get(mdb, &br_dst);
 136}
 137#endif
 138
 139struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,
 140                                        struct sk_buff *skb)
 141{
 142        struct net_bridge_mdb_htable *mdb = rcu_dereference(br->mdb);
 143        struct br_ip ip;
 144
 145        if (br->multicast_disabled)
 146                return NULL;
 147
 148        if (BR_INPUT_SKB_CB(skb)->igmp)
 149                return NULL;
 150
 151        ip.proto = skb->protocol;
 152
 153        switch (skb->protocol) {
 154        case htons(ETH_P_IP):
 155                ip.u.ip4 = ip_hdr(skb)->daddr;
 156                break;
 157#if IS_ENABLED(CONFIG_IPV6)
 158        case htons(ETH_P_IPV6):
 159                ip.u.ip6 = ipv6_hdr(skb)->daddr;
 160                break;
 161#endif
 162        default:
 163                return NULL;
 164        }
 165
 166        return br_mdb_ip_get(mdb, &ip);
 167}
 168
 169static void br_mdb_free(struct rcu_head *head)
 170{
 171        struct net_bridge_mdb_htable *mdb =
 172                container_of(head, struct net_bridge_mdb_htable, rcu);
 173        struct net_bridge_mdb_htable *old = mdb->old;
 174
 175        mdb->old = NULL;
 176        kfree(old->mhash);
 177        kfree(old);
 178}
 179
 180static int br_mdb_copy(struct net_bridge_mdb_htable *new,
 181                       struct net_bridge_mdb_htable *old,
 182                       int elasticity)
 183{
 184        struct net_bridge_mdb_entry *mp;
 185        struct hlist_node *p;
 186        int maxlen;
 187        int len;
 188        int i;
 189
 190        for (i = 0; i < old->max; i++)
 191                hlist_for_each_entry(mp, p, &old->mhash[i], hlist[old->ver])
 192                        hlist_add_head(&mp->hlist[new->ver],
 193                                       &new->mhash[br_ip_hash(new, &mp->addr)]);
 194
 195        if (!elasticity)
 196                return 0;
 197
 198        maxlen = 0;
 199        for (i = 0; i < new->max; i++) {
 200                len = 0;
 201                hlist_for_each_entry(mp, p, &new->mhash[i], hlist[new->ver])
 202                        len++;
 203                if (len > maxlen)
 204                        maxlen = len;
 205        }
 206
 207        return maxlen > elasticity ? -EINVAL : 0;
 208}
 209
 210static void br_multicast_free_pg(struct rcu_head *head)
 211{
 212        struct net_bridge_port_group *p =
 213                container_of(head, struct net_bridge_port_group, rcu);
 214
 215        kfree(p);
 216}
 217
 218static void br_multicast_free_group(struct rcu_head *head)
 219{
 220        struct net_bridge_mdb_entry *mp =
 221                container_of(head, struct net_bridge_mdb_entry, rcu);
 222
 223        kfree(mp);
 224}
 225
 226static void br_multicast_group_expired(unsigned long data)
 227{
 228        struct net_bridge_mdb_entry *mp = (void *)data;
 229        struct net_bridge *br = mp->br;
 230        struct net_bridge_mdb_htable *mdb;
 231
 232        spin_lock(&br->multicast_lock);
 233        if (!netif_running(br->dev) || timer_pending(&mp->timer))
 234                goto out;
 235
 236        mp->mglist = false;
 237
 238        if (mp->ports)
 239                goto out;
 240
 241        mdb = mlock_dereference(br->mdb, br);
 242
 243        hlist_del_rcu(&mp->hlist[mdb->ver]);
 244        mdb->size--;
 245
 246        call_rcu_bh(&mp->rcu, br_multicast_free_group);
 247
 248out:
 249        spin_unlock(&br->multicast_lock);
 250}
 251
 252static void br_multicast_del_pg(struct net_bridge *br,
 253                                struct net_bridge_port_group *pg)
 254{
 255        struct net_bridge_mdb_htable *mdb;
 256        struct net_bridge_mdb_entry *mp;
 257        struct net_bridge_port_group *p;
 258        struct net_bridge_port_group __rcu **pp;
 259
 260        mdb = mlock_dereference(br->mdb, br);
 261
 262        mp = br_mdb_ip_get(mdb, &pg->addr);
 263        if (WARN_ON(!mp))
 264                return;
 265
 266        for (pp = &mp->ports;
 267             (p = mlock_dereference(*pp, br)) != NULL;
 268             pp = &p->next) {
 269                if (p != pg)
 270                        continue;
 271
 272                rcu_assign_pointer(*pp, p->next);
 273                hlist_del_init(&p->mglist);
 274                del_timer(&p->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_PAD1;              /* Pad1 */
 464        hopopt[7] = IPV6_TLV_PAD1;              /* Pad1 */
 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 struct net_bridge_mdb_entry *br_multicast_get_group(
 511        struct net_bridge *br, struct net_bridge_port *port,
 512        struct br_ip *group, int hash)
 513{
 514        struct net_bridge_mdb_htable *mdb;
 515        struct net_bridge_mdb_entry *mp;
 516        struct hlist_node *p;
 517        unsigned int count = 0;
 518        unsigned int max;
 519        int elasticity;
 520        int err;
 521
 522        mdb = rcu_dereference_protected(br->mdb, 1);
 523        hlist_for_each_entry(mp, p, &mdb->mhash[hash], hlist[mdb->ver]) {
 524                count++;
 525                if (unlikely(br_ip_equal(group, &mp->addr)))
 526                        return mp;
 527        }
 528
 529        elasticity = 0;
 530        max = mdb->max;
 531
 532        if (unlikely(count > br->hash_elasticity && count)) {
 533                if (net_ratelimit())
 534                        br_info(br, "Multicast hash table "
 535                                "chain limit reached: %s\n",
 536                                port ? port->dev->name : br->dev->name);
 537
 538                elasticity = br->hash_elasticity;
 539        }
 540
 541        if (mdb->size >= max) {
 542                max *= 2;
 543                if (unlikely(max > br->hash_max)) {
 544                        br_warn(br, "Multicast hash table maximum of %d "
 545                                "reached, disabling snooping: %s\n",
 546                                br->hash_max,
 547                                port ? port->dev->name : br->dev->name);
 548                        err = -E2BIG;
 549disable:
 550                        br->multicast_disabled = 1;
 551                        goto err;
 552                }
 553        }
 554
 555        if (max > mdb->max || elasticity) {
 556                if (mdb->old) {
 557                        if (net_ratelimit())
 558                                br_info(br, "Multicast hash table "
 559                                        "on fire: %s\n",
 560                                        port ? port->dev->name : br->dev->name);
 561                        err = -EEXIST;
 562                        goto err;
 563                }
 564
 565                err = br_mdb_rehash(&br->mdb, max, elasticity);
 566                if (err) {
 567                        br_warn(br, "Cannot rehash multicast "
 568                                "hash table, disabling snooping: %s, %d, %d\n",
 569                                port ? port->dev->name : br->dev->name,
 570                                mdb->size, err);
 571                        goto disable;
 572                }
 573
 574                err = -EAGAIN;
 575                goto err;
 576        }
 577
 578        return NULL;
 579
 580err:
 581        mp = ERR_PTR(err);
 582        return mp;
 583}
 584
 585static struct net_bridge_mdb_entry *br_multicast_new_group(
 586        struct net_bridge *br, struct net_bridge_port *port,
 587        struct br_ip *group)
 588{
 589        struct net_bridge_mdb_htable *mdb;
 590        struct net_bridge_mdb_entry *mp;
 591        int hash;
 592        int err;
 593
 594        mdb = rcu_dereference_protected(br->mdb, 1);
 595        if (!mdb) {
 596                err = br_mdb_rehash(&br->mdb, BR_HASH_SIZE, 0);
 597                if (err)
 598                        return ERR_PTR(err);
 599                goto rehash;
 600        }
 601
 602        hash = br_ip_hash(mdb, group);
 603        mp = br_multicast_get_group(br, port, group, hash);
 604        switch (PTR_ERR(mp)) {
 605        case 0:
 606                break;
 607
 608        case -EAGAIN:
 609rehash:
 610                mdb = rcu_dereference_protected(br->mdb, 1);
 611                hash = br_ip_hash(mdb, group);
 612                break;
 613
 614        default:
 615                goto out;
 616        }
 617
 618        mp = kzalloc(sizeof(*mp), GFP_ATOMIC);
 619        if (unlikely(!mp))
 620                return ERR_PTR(-ENOMEM);
 621
 622        mp->br = br;
 623        mp->addr = *group;
 624        setup_timer(&mp->timer, br_multicast_group_expired,
 625                    (unsigned long)mp);
 626
 627        hlist_add_head_rcu(&mp->hlist[mdb->ver], &mdb->mhash[hash]);
 628        mdb->size++;
 629
 630out:
 631        return mp;
 632}
 633
 634static int br_multicast_add_group(struct net_bridge *br,
 635                                  struct net_bridge_port *port,
 636                                  struct br_ip *group)
 637{
 638        struct net_bridge_mdb_entry *mp;
 639        struct net_bridge_port_group *p;
 640        struct net_bridge_port_group __rcu **pp;
 641        unsigned long now = jiffies;
 642        int err;
 643
 644        spin_lock(&br->multicast_lock);
 645        if (!netif_running(br->dev) ||
 646            (port && port->state == BR_STATE_DISABLED))
 647                goto out;
 648
 649        mp = br_multicast_new_group(br, port, group);
 650        err = PTR_ERR(mp);
 651        if (IS_ERR(mp))
 652                goto err;
 653
 654        if (!port) {
 655                mp->mglist = true;
 656                mod_timer(&mp->timer, now + br->multicast_membership_interval);
 657                goto out;
 658        }
 659
 660        for (pp = &mp->ports;
 661             (p = mlock_dereference(*pp, br)) != NULL;
 662             pp = &p->next) {
 663                if (p->port == port)
 664                        goto found;
 665                if ((unsigned long)p->port < (unsigned long)port)
 666                        break;
 667        }
 668
 669        p = kzalloc(sizeof(*p), GFP_ATOMIC);
 670        err = -ENOMEM;
 671        if (unlikely(!p))
 672                goto err;
 673
 674        p->addr = *group;
 675        p->port = port;
 676        p->next = *pp;
 677        hlist_add_head(&p->mglist, &port->mglist);
 678        setup_timer(&p->timer, br_multicast_port_group_expired,
 679                    (unsigned long)p);
 680
 681        rcu_assign_pointer(*pp, p);
 682
 683found:
 684        mod_timer(&p->timer, now + br->multicast_membership_interval);
 685out:
 686        err = 0;
 687
 688err:
 689        spin_unlock(&br->multicast_lock);
 690        return err;
 691}
 692
 693static int br_ip4_multicast_add_group(struct net_bridge *br,
 694                                      struct net_bridge_port *port,
 695                                      __be32 group)
 696{
 697        struct br_ip br_group;
 698
 699        if (ipv4_is_local_multicast(group))
 700                return 0;
 701
 702        br_group.u.ip4 = group;
 703        br_group.proto = htons(ETH_P_IP);
 704
 705        return br_multicast_add_group(br, port, &br_group);
 706}
 707
 708#if IS_ENABLED(CONFIG_IPV6)
 709static int br_ip6_multicast_add_group(struct net_bridge *br,
 710                                      struct net_bridge_port *port,
 711                                      const struct in6_addr *group)
 712{
 713        struct br_ip br_group;
 714
 715        if (!ipv6_is_transient_multicast(group))
 716                return 0;
 717
 718        br_group.u.ip6 = *group;
 719        br_group.proto = htons(ETH_P_IPV6);
 720
 721        return br_multicast_add_group(br, port, &br_group);
 722}
 723#endif
 724
 725static void br_multicast_router_expired(unsigned long data)
 726{
 727        struct net_bridge_port *port = (void *)data;
 728        struct net_bridge *br = port->br;
 729
 730        spin_lock(&br->multicast_lock);
 731        if (port->multicast_router != 1 ||
 732            timer_pending(&port->multicast_router_timer) ||
 733            hlist_unhashed(&port->rlist))
 734                goto out;
 735
 736        hlist_del_init_rcu(&port->rlist);
 737
 738out:
 739        spin_unlock(&br->multicast_lock);
 740}
 741
 742static void br_multicast_local_router_expired(unsigned long data)
 743{
 744}
 745
 746static void br_multicast_querier_expired(unsigned long data)
 747{
 748        struct net_bridge *br = (void *)data;
 749
 750        spin_lock(&br->multicast_lock);
 751        if (!netif_running(br->dev) || br->multicast_disabled)
 752                goto out;
 753
 754        br_multicast_start_querier(br);
 755
 756out:
 757        spin_unlock(&br->multicast_lock);
 758}
 759
 760static void __br_multicast_send_query(struct net_bridge *br,
 761                                      struct net_bridge_port *port,
 762                                      struct br_ip *ip)
 763{
 764        struct sk_buff *skb;
 765
 766        skb = br_multicast_alloc_query(br, ip);
 767        if (!skb)
 768                return;
 769
 770        if (port) {
 771                __skb_push(skb, sizeof(struct ethhdr));
 772                skb->dev = port->dev;
 773                NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
 774                        dev_queue_xmit);
 775        } else
 776                netif_rx(skb);
 777}
 778
 779static void br_multicast_send_query(struct net_bridge *br,
 780                                    struct net_bridge_port *port, u32 sent)
 781{
 782        unsigned long time;
 783        struct br_ip br_group;
 784
 785        if (!netif_running(br->dev) || br->multicast_disabled ||
 786            !br->multicast_querier ||
 787            timer_pending(&br->multicast_querier_timer))
 788                return;
 789
 790        memset(&br_group.u, 0, sizeof(br_group.u));
 791
 792        br_group.proto = htons(ETH_P_IP);
 793        __br_multicast_send_query(br, port, &br_group);
 794
 795#if IS_ENABLED(CONFIG_IPV6)
 796        br_group.proto = htons(ETH_P_IPV6);
 797        __br_multicast_send_query(br, port, &br_group);
 798#endif
 799
 800        time = jiffies;
 801        time += sent < br->multicast_startup_query_count ?
 802                br->multicast_startup_query_interval :
 803                br->multicast_query_interval;
 804        mod_timer(port ? &port->multicast_query_timer :
 805                         &br->multicast_query_timer, time);
 806}
 807
 808static void br_multicast_port_query_expired(unsigned long data)
 809{
 810        struct net_bridge_port *port = (void *)data;
 811        struct net_bridge *br = port->br;
 812
 813        spin_lock(&br->multicast_lock);
 814        if (port->state == BR_STATE_DISABLED ||
 815            port->state == BR_STATE_BLOCKING)
 816                goto out;
 817
 818        if (port->multicast_startup_queries_sent <
 819            br->multicast_startup_query_count)
 820                port->multicast_startup_queries_sent++;
 821
 822        br_multicast_send_query(port->br, port,
 823                                port->multicast_startup_queries_sent);
 824
 825out:
 826        spin_unlock(&br->multicast_lock);
 827}
 828
 829void br_multicast_add_port(struct net_bridge_port *port)
 830{
 831        port->multicast_router = 1;
 832
 833        setup_timer(&port->multicast_router_timer, br_multicast_router_expired,
 834                    (unsigned long)port);
 835        setup_timer(&port->multicast_query_timer,
 836                    br_multicast_port_query_expired, (unsigned long)port);
 837}
 838
 839void br_multicast_del_port(struct net_bridge_port *port)
 840{
 841        del_timer_sync(&port->multicast_router_timer);
 842}
 843
 844static void __br_multicast_enable_port(struct net_bridge_port *port)
 845{
 846        port->multicast_startup_queries_sent = 0;
 847
 848        if (try_to_del_timer_sync(&port->multicast_query_timer) >= 0 ||
 849            del_timer(&port->multicast_query_timer))
 850                mod_timer(&port->multicast_query_timer, jiffies);
 851}
 852
 853void br_multicast_enable_port(struct net_bridge_port *port)
 854{
 855        struct net_bridge *br = port->br;
 856
 857        spin_lock(&br->multicast_lock);
 858        if (br->multicast_disabled || !netif_running(br->dev))
 859                goto out;
 860
 861        __br_multicast_enable_port(port);
 862
 863out:
 864        spin_unlock(&br->multicast_lock);
 865}
 866
 867void br_multicast_disable_port(struct net_bridge_port *port)
 868{
 869        struct net_bridge *br = port->br;
 870        struct net_bridge_port_group *pg;
 871        struct hlist_node *p, *n;
 872
 873        spin_lock(&br->multicast_lock);
 874        hlist_for_each_entry_safe(pg, p, n, &port->mglist, mglist)
 875                br_multicast_del_pg(br, pg);
 876
 877        if (!hlist_unhashed(&port->rlist))
 878                hlist_del_init_rcu(&port->rlist);
 879        del_timer(&port->multicast_router_timer);
 880        del_timer(&port->multicast_query_timer);
 881        spin_unlock(&br->multicast_lock);
 882}
 883
 884static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
 885                                         struct net_bridge_port *port,
 886                                         struct sk_buff *skb)
 887{
 888        struct igmpv3_report *ih;
 889        struct igmpv3_grec *grec;
 890        int i;
 891        int len;
 892        int num;
 893        int type;
 894        int err = 0;
 895        __be32 group;
 896
 897        if (!pskb_may_pull(skb, sizeof(*ih)))
 898                return -EINVAL;
 899
 900        ih = igmpv3_report_hdr(skb);
 901        num = ntohs(ih->ngrec);
 902        len = sizeof(*ih);
 903
 904        for (i = 0; i < num; i++) {
 905                len += sizeof(*grec);
 906                if (!pskb_may_pull(skb, len))
 907                        return -EINVAL;
 908
 909                grec = (void *)(skb->data + len - sizeof(*grec));
 910                group = grec->grec_mca;
 911                type = grec->grec_type;
 912
 913                len += ntohs(grec->grec_nsrcs) * 4;
 914                if (!pskb_may_pull(skb, len))
 915                        return -EINVAL;
 916
 917                /* We treat this as an IGMPv2 report for now. */
 918                switch (type) {
 919                case IGMPV3_MODE_IS_INCLUDE:
 920                case IGMPV3_MODE_IS_EXCLUDE:
 921                case IGMPV3_CHANGE_TO_INCLUDE:
 922                case IGMPV3_CHANGE_TO_EXCLUDE:
 923                case IGMPV3_ALLOW_NEW_SOURCES:
 924                case IGMPV3_BLOCK_OLD_SOURCES:
 925                        break;
 926
 927                default:
 928                        continue;
 929                }
 930
 931                err = br_ip4_multicast_add_group(br, port, group);
 932                if (err)
 933                        break;
 934        }
 935
 936        return err;
 937}
 938
 939#if IS_ENABLED(CONFIG_IPV6)
 940static int br_ip6_multicast_mld2_report(struct net_bridge *br,
 941                                        struct net_bridge_port *port,
 942                                        struct sk_buff *skb)
 943{
 944        struct icmp6hdr *icmp6h;
 945        struct mld2_grec *grec;
 946        int i;
 947        int len;
 948        int num;
 949        int err = 0;
 950
 951        if (!pskb_may_pull(skb, sizeof(*icmp6h)))
 952                return -EINVAL;
 953
 954        icmp6h = icmp6_hdr(skb);
 955        num = ntohs(icmp6h->icmp6_dataun.un_data16[1]);
 956        len = sizeof(*icmp6h);
 957
 958        for (i = 0; i < num; i++) {
 959                __be16 *nsrcs, _nsrcs;
 960
 961                nsrcs = skb_header_pointer(skb,
 962                                           len + offsetof(struct mld2_grec,
 963                                                          grec_nsrcs),
 964                                           sizeof(_nsrcs), &_nsrcs);
 965                if (!nsrcs)
 966                        return -EINVAL;
 967
 968                if (!pskb_may_pull(skb,
 969                                   len + sizeof(*grec) +
 970                                   sizeof(struct in6_addr) * ntohs(*nsrcs)))
 971                        return -EINVAL;
 972
 973                grec = (struct mld2_grec *)(skb->data + len);
 974                len += sizeof(*grec) +
 975                       sizeof(struct in6_addr) * ntohs(*nsrcs);
 976
 977                /* We treat these as MLDv1 reports for now. */
 978                switch (grec->grec_type) {
 979                case MLD2_MODE_IS_INCLUDE:
 980                case MLD2_MODE_IS_EXCLUDE:
 981                case MLD2_CHANGE_TO_INCLUDE:
 982                case MLD2_CHANGE_TO_EXCLUDE:
 983                case MLD2_ALLOW_NEW_SOURCES:
 984                case MLD2_BLOCK_OLD_SOURCES:
 985                        break;
 986
 987                default:
 988                        continue;
 989                }
 990
 991                err = br_ip6_multicast_add_group(br, port, &grec->grec_mca);
 992                if (!err)
 993                        break;
 994        }
 995
 996        return err;
 997}
 998#endif
 999
1000/*
1001 * Add port to rotuer_list
1002 *  list is maintained ordered by pointer value
1003 *  and locked by br->multicast_lock and RCU
1004 */
1005static void br_multicast_add_router(struct net_bridge *br,
1006                                    struct net_bridge_port *port)
1007{
1008        struct net_bridge_port *p;
1009        struct hlist_node *n, *slot = NULL;
1010
1011        hlist_for_each_entry(p, n, &br->router_list, rlist) {
1012                if ((unsigned long) port >= (unsigned long) p)
1013                        break;
1014                slot = n;
1015        }
1016
1017        if (slot)
1018                hlist_add_after_rcu(slot, &port->rlist);
1019        else
1020                hlist_add_head_rcu(&port->rlist, &br->router_list);
1021}
1022
1023static void br_multicast_mark_router(struct net_bridge *br,
1024                                     struct net_bridge_port *port)
1025{
1026        unsigned long now = jiffies;
1027
1028        if (!port) {
1029                if (br->multicast_router == 1)
1030                        mod_timer(&br->multicast_router_timer,
1031                                  now + br->multicast_querier_interval);
1032                return;
1033        }
1034
1035        if (port->multicast_router != 1)
1036                return;
1037
1038        if (!hlist_unhashed(&port->rlist))
1039                goto timer;
1040
1041        br_multicast_add_router(br, port);
1042
1043timer:
1044        mod_timer(&port->multicast_router_timer,
1045                  now + br->multicast_querier_interval);
1046}
1047
1048static void br_multicast_query_received(struct net_bridge *br,
1049                                        struct net_bridge_port *port,
1050                                        int saddr)
1051{
1052        if (saddr)
1053                mod_timer(&br->multicast_querier_timer,
1054                          jiffies + br->multicast_querier_interval);
1055        else if (timer_pending(&br->multicast_querier_timer))
1056                return;
1057
1058        br_multicast_mark_router(br, port);
1059}
1060
1061static int br_ip4_multicast_query(struct net_bridge *br,
1062                                  struct net_bridge_port *port,
1063                                  struct sk_buff *skb)
1064{
1065        const struct iphdr *iph = ip_hdr(skb);
1066        struct igmphdr *ih = igmp_hdr(skb);
1067        struct net_bridge_mdb_entry *mp;
1068        struct igmpv3_query *ih3;
1069        struct net_bridge_port_group *p;
1070        struct net_bridge_port_group __rcu **pp;
1071        unsigned long max_delay;
1072        unsigned long now = jiffies;
1073        __be32 group;
1074        int err = 0;
1075
1076        spin_lock(&br->multicast_lock);
1077        if (!netif_running(br->dev) ||
1078            (port && port->state == BR_STATE_DISABLED))
1079                goto out;
1080
1081        br_multicast_query_received(br, port, !!iph->saddr);
1082
1083        group = ih->group;
1084
1085        if (skb->len == sizeof(*ih)) {
1086                max_delay = ih->code * (HZ / IGMP_TIMER_SCALE);
1087
1088                if (!max_delay) {
1089                        max_delay = 10 * HZ;
1090                        group = 0;
1091                }
1092        } else {
1093                if (!pskb_may_pull(skb, sizeof(struct igmpv3_query))) {
1094                        err = -EINVAL;
1095                        goto out;
1096                }
1097
1098                ih3 = igmpv3_query_hdr(skb);
1099                if (ih3->nsrcs)
1100                        goto out;
1101
1102                max_delay = ih3->code ?
1103                            IGMPV3_MRC(ih3->code) * (HZ / IGMP_TIMER_SCALE) : 1;
1104        }
1105
1106        if (!group)
1107                goto out;
1108
1109        mp = br_mdb_ip4_get(mlock_dereference(br->mdb, br), group);
1110        if (!mp)
1111                goto out;
1112
1113        max_delay *= br->multicast_last_member_count;
1114
1115        if (mp->mglist &&
1116            (timer_pending(&mp->timer) ?
1117             time_after(mp->timer.expires, now + max_delay) :
1118             try_to_del_timer_sync(&mp->timer) >= 0))
1119                mod_timer(&mp->timer, now + max_delay);
1120
1121        for (pp = &mp->ports;
1122             (p = mlock_dereference(*pp, br)) != NULL;
1123             pp = &p->next) {
1124                if (timer_pending(&p->timer) ?
1125                    time_after(p->timer.expires, now + max_delay) :
1126                    try_to_del_timer_sync(&p->timer) >= 0)
1127                        mod_timer(&p->timer, now + max_delay);
1128        }
1129
1130out:
1131        spin_unlock(&br->multicast_lock);
1132        return err;
1133}
1134
1135#if IS_ENABLED(CONFIG_IPV6)
1136static int br_ip6_multicast_query(struct net_bridge *br,
1137                                  struct net_bridge_port *port,
1138                                  struct sk_buff *skb)
1139{
1140        const struct ipv6hdr *ip6h = ipv6_hdr(skb);
1141        struct mld_msg *mld = (struct mld_msg *) icmp6_hdr(skb);
1142        struct net_bridge_mdb_entry *mp;
1143        struct mld2_query *mld2q;
1144        struct net_bridge_port_group *p;
1145        struct net_bridge_port_group __rcu **pp;
1146        unsigned long max_delay;
1147        unsigned long now = jiffies;
1148        const struct in6_addr *group = NULL;
1149        int err = 0;
1150
1151        spin_lock(&br->multicast_lock);
1152        if (!netif_running(br->dev) ||
1153            (port && port->state == BR_STATE_DISABLED))
1154                goto out;
1155
1156        br_multicast_query_received(br, port, !ipv6_addr_any(&ip6h->saddr));
1157
1158        if (skb->len == sizeof(*mld)) {
1159                if (!pskb_may_pull(skb, sizeof(*mld))) {
1160                        err = -EINVAL;
1161                        goto out;
1162                }
1163                mld = (struct mld_msg *) icmp6_hdr(skb);
1164                max_delay = msecs_to_jiffies(ntohs(mld->mld_maxdelay));
1165                if (max_delay)
1166                        group = &mld->mld_mca;
1167        } else if (skb->len >= sizeof(*mld2q)) {
1168                if (!pskb_may_pull(skb, sizeof(*mld2q))) {
1169                        err = -EINVAL;
1170                        goto out;
1171                }
1172                mld2q = (struct mld2_query *)icmp6_hdr(skb);
1173                if (!mld2q->mld2q_nsrcs)
1174                        group = &mld2q->mld2q_mca;
1175                max_delay = mld2q->mld2q_mrc ? MLDV2_MRC(mld2q->mld2q_mrc) : 1;
1176        }
1177
1178        if (!group)
1179                goto out;
1180
1181        mp = br_mdb_ip6_get(mlock_dereference(br->mdb, br), group);
1182        if (!mp)
1183                goto out;
1184
1185        max_delay *= br->multicast_last_member_count;
1186        if (mp->mglist &&
1187            (timer_pending(&mp->timer) ?
1188             time_after(mp->timer.expires, now + max_delay) :
1189             try_to_del_timer_sync(&mp->timer) >= 0))
1190                mod_timer(&mp->timer, now + max_delay);
1191
1192        for (pp = &mp->ports;
1193             (p = mlock_dereference(*pp, br)) != NULL;
1194             pp = &p->next) {
1195                if (timer_pending(&p->timer) ?
1196                    time_after(p->timer.expires, now + max_delay) :
1197                    try_to_del_timer_sync(&p->timer) >= 0)
1198                        mod_timer(&p->timer, now + max_delay);
1199        }
1200
1201out:
1202        spin_unlock(&br->multicast_lock);
1203        return err;
1204}
1205#endif
1206
1207static void br_multicast_leave_group(struct net_bridge *br,
1208                                     struct net_bridge_port *port,
1209                                     struct br_ip *group)
1210{
1211        struct net_bridge_mdb_htable *mdb;
1212        struct net_bridge_mdb_entry *mp;
1213        struct net_bridge_port_group *p;
1214        unsigned long now;
1215        unsigned long time;
1216
1217        spin_lock(&br->multicast_lock);
1218        if (!netif_running(br->dev) ||
1219            (port && port->state == BR_STATE_DISABLED) ||
1220            timer_pending(&br->multicast_querier_timer))
1221                goto out;
1222
1223        mdb = mlock_dereference(br->mdb, br);
1224        mp = br_mdb_ip_get(mdb, group);
1225        if (!mp)
1226                goto out;
1227
1228        now = jiffies;
1229        time = now + br->multicast_last_member_count *
1230                     br->multicast_last_member_interval;
1231
1232        if (!port) {
1233                if (mp->mglist &&
1234                    (timer_pending(&mp->timer) ?
1235                     time_after(mp->timer.expires, time) :
1236                     try_to_del_timer_sync(&mp->timer) >= 0)) {
1237                        mod_timer(&mp->timer, time);
1238                }
1239
1240                goto out;
1241        }
1242
1243        for (p = mlock_dereference(mp->ports, br);
1244             p != NULL;
1245             p = mlock_dereference(p->next, br)) {
1246                if (p->port != port)
1247                        continue;
1248
1249                if (!hlist_unhashed(&p->mglist) &&
1250                    (timer_pending(&p->timer) ?
1251                     time_after(p->timer.expires, time) :
1252                     try_to_del_timer_sync(&p->timer) >= 0)) {
1253                        mod_timer(&p->timer, time);
1254                }
1255
1256                break;
1257        }
1258
1259out:
1260        spin_unlock(&br->multicast_lock);
1261}
1262
1263static void br_ip4_multicast_leave_group(struct net_bridge *br,
1264                                         struct net_bridge_port *port,
1265                                         __be32 group)
1266{
1267        struct br_ip br_group;
1268
1269        if (ipv4_is_local_multicast(group))
1270                return;
1271
1272        br_group.u.ip4 = group;
1273        br_group.proto = htons(ETH_P_IP);
1274
1275        br_multicast_leave_group(br, port, &br_group);
1276}
1277
1278#if IS_ENABLED(CONFIG_IPV6)
1279static void br_ip6_multicast_leave_group(struct net_bridge *br,
1280                                         struct net_bridge_port *port,
1281                                         const struct in6_addr *group)
1282{
1283        struct br_ip br_group;
1284
1285        if (!ipv6_is_transient_multicast(group))
1286                return;
1287
1288        br_group.u.ip6 = *group;
1289        br_group.proto = htons(ETH_P_IPV6);
1290
1291        br_multicast_leave_group(br, port, &br_group);
1292}
1293#endif
1294
1295static int br_multicast_ipv4_rcv(struct net_bridge *br,
1296                                 struct net_bridge_port *port,
1297                                 struct sk_buff *skb)
1298{
1299        struct sk_buff *skb2 = skb;
1300        const struct iphdr *iph;
1301        struct igmphdr *ih;
1302        unsigned int len;
1303        unsigned int offset;
1304        int err;
1305
1306        /* We treat OOM as packet loss for now. */
1307        if (!pskb_may_pull(skb, sizeof(*iph)))
1308                return -EINVAL;
1309
1310        iph = ip_hdr(skb);
1311
1312        if (iph->ihl < 5 || iph->version != 4)
1313                return -EINVAL;
1314
1315        if (!pskb_may_pull(skb, ip_hdrlen(skb)))
1316                return -EINVAL;
1317
1318        iph = ip_hdr(skb);
1319
1320        if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1321                return -EINVAL;
1322
1323        if (iph->protocol != IPPROTO_IGMP) {
1324                if ((iph->daddr & IGMP_LOCAL_GROUP_MASK) != IGMP_LOCAL_GROUP)
1325                        BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1326                return 0;
1327        }
1328
1329        len = ntohs(iph->tot_len);
1330        if (skb->len < len || len < ip_hdrlen(skb))
1331                return -EINVAL;
1332
1333        if (skb->len > len) {
1334                skb2 = skb_clone(skb, GFP_ATOMIC);
1335                if (!skb2)
1336                        return -ENOMEM;
1337
1338                err = pskb_trim_rcsum(skb2, len);
1339                if (err)
1340                        goto err_out;
1341        }
1342
1343        len -= ip_hdrlen(skb2);
1344        offset = skb_network_offset(skb2) + ip_hdrlen(skb2);
1345        __skb_pull(skb2, offset);
1346        skb_reset_transport_header(skb2);
1347
1348        err = -EINVAL;
1349        if (!pskb_may_pull(skb2, sizeof(*ih)))
1350                goto out;
1351
1352        switch (skb2->ip_summed) {
1353        case CHECKSUM_COMPLETE:
1354                if (!csum_fold(skb2->csum))
1355                        break;
1356                /* fall through */
1357        case CHECKSUM_NONE:
1358                skb2->csum = 0;
1359                if (skb_checksum_complete(skb2))
1360                        goto out;
1361        }
1362
1363        err = 0;
1364
1365        BR_INPUT_SKB_CB(skb)->igmp = 1;
1366        ih = igmp_hdr(skb2);
1367
1368        switch (ih->type) {
1369        case IGMP_HOST_MEMBERSHIP_REPORT:
1370        case IGMPV2_HOST_MEMBERSHIP_REPORT:
1371                BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1372                err = br_ip4_multicast_add_group(br, port, ih->group);
1373                break;
1374        case IGMPV3_HOST_MEMBERSHIP_REPORT:
1375                err = br_ip4_multicast_igmp3_report(br, port, skb2);
1376                break;
1377        case IGMP_HOST_MEMBERSHIP_QUERY:
1378                err = br_ip4_multicast_query(br, port, skb2);
1379                break;
1380        case IGMP_HOST_LEAVE_MESSAGE:
1381                br_ip4_multicast_leave_group(br, port, ih->group);
1382                break;
1383        }
1384
1385out:
1386        __skb_push(skb2, offset);
1387err_out:
1388        if (skb2 != skb)
1389                kfree_skb(skb2);
1390        return err;
1391}
1392
1393#if IS_ENABLED(CONFIG_IPV6)
1394static int br_multicast_ipv6_rcv(struct net_bridge *br,
1395                                 struct net_bridge_port *port,
1396                                 struct sk_buff *skb)
1397{
1398        struct sk_buff *skb2;
1399        const struct ipv6hdr *ip6h;
1400        u8 icmp6_type;
1401        u8 nexthdr;
1402        __be16 frag_off;
1403        unsigned int len;
1404        int offset;
1405        int err;
1406
1407        if (!pskb_may_pull(skb, sizeof(*ip6h)))
1408                return -EINVAL;
1409
1410        ip6h = ipv6_hdr(skb);
1411
1412        /*
1413         * We're interested in MLD messages only.
1414         *  - Version is 6
1415         *  - MLD has always Router Alert hop-by-hop option
1416         *  - But we do not support jumbrograms.
1417         */
1418        if (ip6h->version != 6 ||
1419            ip6h->nexthdr != IPPROTO_HOPOPTS ||
1420            ip6h->payload_len == 0)
1421                return 0;
1422
1423        len = ntohs(ip6h->payload_len) + sizeof(*ip6h);
1424        if (skb->len < len)
1425                return -EINVAL;
1426
1427        nexthdr = ip6h->nexthdr;
1428        offset = ipv6_skip_exthdr(skb, sizeof(*ip6h), &nexthdr, &frag_off);
1429
1430        if (offset < 0 || nexthdr != IPPROTO_ICMPV6)
1431                return 0;
1432
1433        /* Okay, we found ICMPv6 header */
1434        skb2 = skb_clone(skb, GFP_ATOMIC);
1435        if (!skb2)
1436                return -ENOMEM;
1437
1438        err = -EINVAL;
1439        if (!pskb_may_pull(skb2, offset + sizeof(struct icmp6hdr)))
1440                goto out;
1441
1442        len -= offset - skb_network_offset(skb2);
1443
1444        __skb_pull(skb2, offset);
1445        skb_reset_transport_header(skb2);
1446        skb_postpull_rcsum(skb2, skb_network_header(skb2),
1447                           skb_network_header_len(skb2));
1448
1449        icmp6_type = icmp6_hdr(skb2)->icmp6_type;
1450
1451        switch (icmp6_type) {
1452        case ICMPV6_MGM_QUERY:
1453        case ICMPV6_MGM_REPORT:
1454        case ICMPV6_MGM_REDUCTION:
1455        case ICMPV6_MLD2_REPORT:
1456                break;
1457        default:
1458                err = 0;
1459                goto out;
1460        }
1461
1462        /* Okay, we found MLD message. Check further. */
1463        if (skb2->len > len) {
1464                err = pskb_trim_rcsum(skb2, len);
1465                if (err)
1466                        goto out;
1467                err = -EINVAL;
1468        }
1469
1470        ip6h = ipv6_hdr(skb2);
1471
1472        switch (skb2->ip_summed) {
1473        case CHECKSUM_COMPLETE:
1474                if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, skb2->len,
1475                                        IPPROTO_ICMPV6, skb2->csum))
1476                        break;
1477                /*FALLTHROUGH*/
1478        case CHECKSUM_NONE:
1479                skb2->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
1480                                                        &ip6h->daddr,
1481                                                        skb2->len,
1482                                                        IPPROTO_ICMPV6, 0));
1483                if (__skb_checksum_complete(skb2))
1484                        goto out;
1485        }
1486
1487        err = 0;
1488
1489        BR_INPUT_SKB_CB(skb)->igmp = 1;
1490
1491        switch (icmp6_type) {
1492        case ICMPV6_MGM_REPORT:
1493            {
1494                struct mld_msg *mld;
1495                if (!pskb_may_pull(skb2, sizeof(*mld))) {
1496                        err = -EINVAL;
1497                        goto out;
1498                }
1499                mld = (struct mld_msg *)skb_transport_header(skb2);
1500                BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
1501                err = br_ip6_multicast_add_group(br, port, &mld->mld_mca);
1502                break;
1503            }
1504        case ICMPV6_MLD2_REPORT:
1505                err = br_ip6_multicast_mld2_report(br, port, skb2);
1506                break;
1507        case ICMPV6_MGM_QUERY:
1508                err = br_ip6_multicast_query(br, port, skb2);
1509                break;
1510        case ICMPV6_MGM_REDUCTION:
1511            {
1512                struct mld_msg *mld;
1513                if (!pskb_may_pull(skb2, sizeof(*mld))) {
1514                        err = -EINVAL;
1515                        goto out;
1516                }
1517                mld = (struct mld_msg *)skb_transport_header(skb2);
1518                br_ip6_multicast_leave_group(br, port, &mld->mld_mca);
1519            }
1520        }
1521
1522out:
1523        kfree_skb(skb2);
1524        return err;
1525}
1526#endif
1527
1528int br_multicast_rcv(struct net_bridge *br, struct net_bridge_port *port,
1529                     struct sk_buff *skb)
1530{
1531        BR_INPUT_SKB_CB(skb)->igmp = 0;
1532        BR_INPUT_SKB_CB(skb)->mrouters_only = 0;
1533
1534        if (br->multicast_disabled)
1535                return 0;
1536
1537        switch (skb->protocol) {
1538        case htons(ETH_P_IP):
1539                return br_multicast_ipv4_rcv(br, port, skb);
1540#if IS_ENABLED(CONFIG_IPV6)
1541        case htons(ETH_P_IPV6):
1542                return br_multicast_ipv6_rcv(br, port, skb);
1543#endif
1544        }
1545
1546        return 0;
1547}
1548
1549static void br_multicast_query_expired(unsigned long data)
1550{
1551        struct net_bridge *br = (void *)data;
1552
1553        spin_lock(&br->multicast_lock);
1554        if (br->multicast_startup_queries_sent <
1555            br->multicast_startup_query_count)
1556                br->multicast_startup_queries_sent++;
1557
1558        br_multicast_send_query(br, NULL, br->multicast_startup_queries_sent);
1559
1560        spin_unlock(&br->multicast_lock);
1561}
1562
1563void br_multicast_init(struct net_bridge *br)
1564{
1565        br->hash_elasticity = 4;
1566        br->hash_max = 512;
1567
1568        br->multicast_router = 1;
1569        br->multicast_querier = 0;
1570        br->multicast_last_member_count = 2;
1571        br->multicast_startup_query_count = 2;
1572
1573        br->multicast_last_member_interval = HZ;
1574        br->multicast_query_response_interval = 10 * HZ;
1575        br->multicast_startup_query_interval = 125 * HZ / 4;
1576        br->multicast_query_interval = 125 * HZ;
1577        br->multicast_querier_interval = 255 * HZ;
1578        br->multicast_membership_interval = 260 * HZ;
1579
1580        spin_lock_init(&br->multicast_lock);
1581        setup_timer(&br->multicast_router_timer,
1582                    br_multicast_local_router_expired, 0);
1583        setup_timer(&br->multicast_querier_timer,
1584                    br_multicast_querier_expired, (unsigned long)br);
1585        setup_timer(&br->multicast_query_timer, br_multicast_query_expired,
1586                    (unsigned long)br);
1587}
1588
1589void br_multicast_open(struct net_bridge *br)
1590{
1591        br->multicast_startup_queries_sent = 0;
1592
1593        if (br->multicast_disabled)
1594                return;
1595
1596        mod_timer(&br->multicast_query_timer, jiffies);
1597}
1598
1599void br_multicast_stop(struct net_bridge *br)
1600{
1601        struct net_bridge_mdb_htable *mdb;
1602        struct net_bridge_mdb_entry *mp;
1603        struct hlist_node *p, *n;
1604        u32 ver;
1605        int i;
1606
1607        del_timer_sync(&br->multicast_router_timer);
1608        del_timer_sync(&br->multicast_querier_timer);
1609        del_timer_sync(&br->multicast_query_timer);
1610
1611        spin_lock_bh(&br->multicast_lock);
1612        mdb = mlock_dereference(br->mdb, br);
1613        if (!mdb)
1614                goto out;
1615
1616        br->mdb = NULL;
1617
1618        ver = mdb->ver;
1619        for (i = 0; i < mdb->max; i++) {
1620                hlist_for_each_entry_safe(mp, p, n, &mdb->mhash[i],
1621                                          hlist[ver]) {
1622                        del_timer(&mp->timer);
1623                        call_rcu_bh(&mp->rcu, br_multicast_free_group);
1624                }
1625        }
1626
1627        if (mdb->old) {
1628                spin_unlock_bh(&br->multicast_lock);
1629                rcu_barrier_bh();
1630                spin_lock_bh(&br->multicast_lock);
1631                WARN_ON(mdb->old);
1632        }
1633
1634        mdb->old = mdb;
1635        call_rcu_bh(&mdb->rcu, br_mdb_free);
1636
1637out:
1638        spin_unlock_bh(&br->multicast_lock);
1639}
1640
1641int br_multicast_set_router(struct net_bridge *br, unsigned long val)
1642{
1643        int err = -ENOENT;
1644
1645        spin_lock_bh(&br->multicast_lock);
1646        if (!netif_running(br->dev))
1647                goto unlock;
1648
1649        switch (val) {
1650        case 0:
1651        case 2:
1652                del_timer(&br->multicast_router_timer);
1653                /* fall through */
1654        case 1:
1655                br->multicast_router = val;
1656                err = 0;
1657                break;
1658
1659        default:
1660                err = -EINVAL;
1661                break;
1662        }
1663
1664unlock:
1665        spin_unlock_bh(&br->multicast_lock);
1666
1667        return err;
1668}
1669
1670int br_multicast_set_port_router(struct net_bridge_port *p, unsigned long val)
1671{
1672        struct net_bridge *br = p->br;
1673        int err = -ENOENT;
1674
1675        spin_lock(&br->multicast_lock);
1676        if (!netif_running(br->dev) || p->state == BR_STATE_DISABLED)
1677                goto unlock;
1678
1679        switch (val) {
1680        case 0:
1681        case 1:
1682        case 2:
1683                p->multicast_router = val;
1684                err = 0;
1685
1686                if (val < 2 && !hlist_unhashed(&p->rlist))
1687                        hlist_del_init_rcu(&p->rlist);
1688
1689                if (val == 1)
1690                        break;
1691
1692                del_timer(&p->multicast_router_timer);
1693
1694                if (val == 0)
1695                        break;
1696
1697                br_multicast_add_router(br, p);
1698                break;
1699
1700        default:
1701                err = -EINVAL;
1702                break;
1703        }
1704
1705unlock:
1706        spin_unlock(&br->multicast_lock);
1707
1708        return err;
1709}
1710
1711static void br_multicast_start_querier(struct net_bridge *br)
1712{
1713        struct net_bridge_port *port;
1714
1715        br_multicast_open(br);
1716
1717        list_for_each_entry(port, &br->port_list, list) {
1718                if (port->state == BR_STATE_DISABLED ||
1719                    port->state == BR_STATE_BLOCKING)
1720                        continue;
1721
1722                __br_multicast_enable_port(port);
1723        }
1724}
1725
1726int br_multicast_toggle(struct net_bridge *br, unsigned long val)
1727{
1728        int err = 0;
1729        struct net_bridge_mdb_htable *mdb;
1730
1731        spin_lock_bh(&br->multicast_lock);
1732        if (br->multicast_disabled == !val)
1733                goto unlock;
1734
1735        br->multicast_disabled = !val;
1736        if (br->multicast_disabled)
1737                goto unlock;
1738
1739        if (!netif_running(br->dev))
1740                goto unlock;
1741
1742        mdb = mlock_dereference(br->mdb, br);
1743        if (mdb) {
1744                if (mdb->old) {
1745                        err = -EEXIST;
1746rollback:
1747                        br->multicast_disabled = !!val;
1748                        goto unlock;
1749                }
1750
1751                err = br_mdb_rehash(&br->mdb, mdb->max,
1752                                    br->hash_elasticity);
1753                if (err)
1754                        goto rollback;
1755        }
1756
1757        br_multicast_start_querier(br);
1758
1759unlock:
1760        spin_unlock_bh(&br->multicast_lock);
1761
1762        return err;
1763}
1764
1765int br_multicast_set_querier(struct net_bridge *br, unsigned long val)
1766{
1767        val = !!val;
1768
1769        spin_lock_bh(&br->multicast_lock);
1770        if (br->multicast_querier == val)
1771                goto unlock;
1772
1773        br->multicast_querier = val;
1774        if (val)
1775                br_multicast_start_querier(br);
1776
1777unlock:
1778        spin_unlock_bh(&br->multicast_lock);
1779
1780        return 0;
1781}
1782
1783int br_multicast_set_hash_max(struct net_bridge *br, unsigned long val)
1784{
1785        int err = -ENOENT;
1786        u32 old;
1787        struct net_bridge_mdb_htable *mdb;
1788
1789        spin_lock(&br->multicast_lock);
1790        if (!netif_running(br->dev))
1791                goto unlock;
1792
1793        err = -EINVAL;
1794        if (!is_power_of_2(val))
1795                goto unlock;
1796
1797        mdb = mlock_dereference(br->mdb, br);
1798        if (mdb && val < mdb->size)
1799                goto unlock;
1800
1801        err = 0;
1802
1803        old = br->hash_max;
1804        br->hash_max = val;
1805
1806        if (mdb) {
1807                if (mdb->old) {
1808                        err = -EEXIST;
1809rollback:
1810                        br->hash_max = old;
1811                        goto unlock;
1812                }
1813
1814                err = br_mdb_rehash(&br->mdb, br->hash_max,
1815                                    br->hash_elasticity);
1816                if (err)
1817                        goto rollback;
1818        }
1819
1820unlock:
1821        spin_unlock(&br->multicast_lock);
1822
1823        return err;
1824}
1825
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