net/bridge/br_mdb.c

   1 #include <linux/err.h>
   2 #include <linux/igmp.h>
   3 #include <linux/kernel.h>
   4 #include <linux/netdevice.h>
   5 #include <linux/rculist.h>
   6 #include <linux/skbuff.h>
   7 #include <linux/if_ether.h>
   8 #include <net/ip.h>
   9 #include <net/netlink.h>
  10 #if IS_ENABLED(CONFIG_IPV6)
  11 #include <net/ipv6.h>
  12 #include <net/addrconf.h>
  13 #endif
  14
  15 #include "br_private.h"
  16
  17 static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
  18                                struct net_device *dev)
  19 {
  20         struct net_bridge *br = netdev_priv(dev);
  21         struct net_bridge_port *p;
  22         struct nlattr *nest;
  23
  24         if (!br->multicast_router || hlist_empty(&br->router_list))
  25                 return 0;
  26
  27         nest = nla_nest_start(skb, MDBA_ROUTER);
  28         if (nest == NULL)
  29                 return -EMSGSIZE;
  30
  31         hlist_for_each_entry_rcu(p, &br->router_list, rlist) {
  32                 if (p && nla_put_u32(skb, MDBA_ROUTER_PORT, p->dev->ifindex))
  33                         goto fail;
  34         }
  35
  36         nla_nest_end(skb, nest);
  37         return 0;
  38 fail:
  39         nla_nest_cancel(skb, nest);
  40         return -EMSGSIZE;
  41 }
  42
  43 static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
  44                             struct net_device *dev)
  45 {
  46         struct net_bridge *br = netdev_priv(dev);
  47         struct net_bridge_mdb_htable *mdb;
  48         struct nlattr *nest, *nest2;
  49         int i, err = 0;
  50         int idx = 0, s_idx = cb->args[1];
  51
  52         if (br->multicast_disabled)
  53                 return 0;
  54
  55         mdb = rcu_dereference(br->mdb);
  56         if (!mdb)
  57                 return 0;
  58
  59         nest = nla_nest_start(skb, MDBA_MDB);
  60         if (nest == NULL)
  61                 return -EMSGSIZE;
  62
  63         for (i = 0; i < mdb->max; i++) {
  64                 struct net_bridge_mdb_entry *mp;
  65                 struct net_bridge_port_group *p;
  66                 struct net_bridge_port_group __rcu **pp;
  67                 struct net_bridge_port *port;
  68
  69                 hlist_for_each_entry_rcu(mp, &mdb->mhash[i], hlist[mdb->ver]) {
  70                         if (idx < s_idx)
  71                                 goto skip;
  72
  73                         nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
  74                         if (nest2 == NULL) {
  75                                 err = -EMSGSIZE;
  76                                 goto out;
  77                         }
  78
  79                         for (pp = &mp->ports;
  80                              (p = rcu_dereference(*pp)) != NULL;
  81                               pp = &p->next) {
  82                                 port = p->port;
  83                                 if (port) {
  84                                         struct br_mdb_entry e;
  85                                         memset(&e, 0, sizeof(e));
  86                                         e.ifindex = port->dev->ifindex;
  87                                         e.state = p->state;
  88                                         if (p->addr.proto == htons(ETH_P_IP))
  89                                                 e.addr.u.ip4 = p->addr.u.ip4;
  90 #if IS_ENABLED(CONFIG_IPV6)
  91                                         if (p->addr.proto == htons(ETH_P_IPV6))
  92                                                 e.addr.u.ip6 = p->addr.u.ip6;
  93 #endif
  94                                         e.addr.proto = p->addr.proto;
  95                                         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {
  96                                                 nla_nest_cancel(skb, nest2);
  97                                                 err = -EMSGSIZE;
  98                                                 goto out;
  99                                         }
 100                                 }
 101                         }
 102                         nla_nest_end(skb, nest2);
 103                 skip:
 104                         idx++;
 105                 }
 106         }
 107
 108 out:
 109         cb->args[1] = idx;
 110         nla_nest_end(skb, nest);
 111         return err;
 112 }
 113
 114 static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 115 {
 116         struct net_device *dev;
 117         struct net *net = sock_net(skb->sk);
 118         struct nlmsghdr *nlh = NULL;
 119         int idx = 0, s_idx;
 120
 121         s_idx = cb->args[0];
 122
 123         rcu_read_lock();
 124
 125         /* In theory this could be wrapped to 0... */
 126         cb->seq = net->dev_base_seq + br_mdb_rehash_seq;
 127
 128         for_each_netdev_rcu(net, dev) {
 129                 if (dev->priv_flags & IFF_EBRIDGE) {
 130                         struct br_port_msg *bpm;
 131
 132                         if (idx < s_idx)
 133                                 goto skip;
 134
 135                         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
 136                                         cb->nlh->nlmsg_seq, RTM_GETMDB,
 137                                         sizeof(*bpm), NLM_F_MULTI);
 138                         if (nlh == NULL)
 139                                 break;
 140
 141                         bpm = nlmsg_data(nlh);
 142                         memset(bpm, 0, sizeof(*bpm));
 143                         bpm->ifindex = dev->ifindex;
 144                         if (br_mdb_fill_info(skb, cb, dev) < 0)
 145                                 goto out;
 146                         if (br_rports_fill_info(skb, cb, dev) < 0)
 147                                 goto out;
 148
 149                         cb->args[1] = 0;
 150                         nlmsg_end(skb, nlh);
 151                 skip:
 152                         idx++;
 153                 }
 154         }
 155
 156 out:
 157         if (nlh)
 158                 nlmsg_end(skb, nlh);
 159         rcu_read_unlock();
 160         cb->args[0] = idx;
 161         return skb->len;
 162 }
 163
 164 static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
 165                                    struct net_device *dev,
 166                                    struct br_mdb_entry *entry, u32 pid,
 167                                    u32 seq, int type, unsigned int flags)
 168 {
 169         struct nlmsghdr *nlh;
 170         struct br_port_msg *bpm;
 171         struct nlattr *nest, *nest2;
 172
 173         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), NLM_F_MULTI);
 174         if (!nlh)
 175                 return -EMSGSIZE;
 176
 177         bpm = nlmsg_data(nlh);
 178         memset(bpm, 0, sizeof(*bpm));
 179         bpm->family  = AF_BRIDGE;
 180         bpm->ifindex = dev->ifindex;
 181         nest = nla_nest_start(skb, MDBA_MDB);
 182         if (nest == NULL)
 183                 goto cancel;
 184         nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
 185         if (nest2 == NULL)
 186                 goto end;
 187
 188         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
 189                 goto end;
 190
 191         nla_nest_end(skb, nest2);
 192         nla_nest_end(skb, nest);
 193         return nlmsg_end(skb, nlh);
 194
 195 end:
 196         nla_nest_end(skb, nest);
 197 cancel:
 198         nlmsg_cancel(skb, nlh);
 199         return -EMSGSIZE;
 200 }
 201
 202 static inline size_t rtnl_mdb_nlmsg_size(void)
 203 {
 204         return NLMSG_ALIGN(sizeof(struct br_port_msg))
 205                 + nla_total_size(sizeof(struct br_mdb_entry));
 206 }
 207
 208 static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
 209                             int type)
 210 {
 211         struct net *net = dev_net(dev);
 212         struct sk_buff *skb;
 213         int err = -ENOBUFS;
 214
 215         skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
 216         if (!skb)
 217                 goto errout;
 218
 219         err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
 220         if (err < 0) {
 221                 kfree_skb(skb);
 222                 goto errout;
 223         }
 224
 225         rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
 226         return;
 227 errout:
 228         rtnl_set_sk_err(net, RTNLGRP_MDB, err);
 229 }
 230
 231 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
 232                    struct br_ip *group, int type)
 233 {
 234         struct br_mdb_entry entry;
 235
 236         memset(&entry, 0, sizeof(entry));
 237         entry.ifindex = port->dev->ifindex;
 238         entry.addr.proto = group->proto;
 239         entry.addr.u.ip4 = group->u.ip4;
 240 #if IS_ENABLED(CONFIG_IPV6)
 241         entry.addr.u.ip6 = group->u.ip6;
 242 #endif
 243         __br_mdb_notify(dev, &entry, type);
 244 }
 245
 246 static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
 247 {
 248         if (entry->ifindex == 0)
 249                 return false;
 250
 251         if (entry->addr.proto == htons(ETH_P_IP)) {
 252                 if (!ipv4_is_multicast(entry->addr.u.ip4))
 253                         return false;
 254                 if (ipv4_is_local_multicast(entry->addr.u.ip4))
 255                         return false;
 256 #if IS_ENABLED(CONFIG_IPV6)
 257         } else if (entry->addr.proto == htons(ETH_P_IPV6)) {
 258                 if (ipv6_addr_is_ll_all_nodes(&entry->addr.u.ip6))
 259                         return false;
 260 #endif
 261         } else
 262                 return false;
 263         if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
 264                 return false;
 265
 266         return true;
 267 }
 268
 269 static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
 270                         struct net_device **pdev, struct br_mdb_entry **pentry)
 271 {
 272         struct net *net = sock_net(skb->sk);
 273         struct br_mdb_entry *entry;
 274         struct br_port_msg *bpm;
 275         struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
 276         struct net_device *dev;
 277         int err;
 278
 279         err = nlmsg_parse(nlh, sizeof(*bpm), tb, MDBA_SET_ENTRY, NULL);
 280         if (err < 0)
 281                 return err;
 282
 283         bpm = nlmsg_data(nlh);
 284         if (bpm->ifindex == 0) {
 285                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid ifindex\n");
 286                 return -EINVAL;
 287         }
 288
 289         dev = __dev_get_by_index(net, bpm->ifindex);
 290         if (dev == NULL) {
 291                 pr_info("PF_BRIDGE: br_mdb_parse() with unknown ifindex\n");
 292                 return -ENODEV;
 293         }
 294
 295         if (!(dev->priv_flags & IFF_EBRIDGE)) {
 296                 pr_info("PF_BRIDGE: br_mdb_parse() with non-bridge\n");
 297                 return -EOPNOTSUPP;
 298         }
 299
 300         *pdev = dev;
 301
 302         if (!tb[MDBA_SET_ENTRY] ||
 303             nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
 304                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid attr\n");
 305                 return -EINVAL;
 306         }
 307
 308         entry = nla_data(tb[MDBA_SET_ENTRY]);
 309         if (!is_valid_mdb_entry(entry)) {
 310                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid entry\n");
 311                 return -EINVAL;
 312         }
 313
 314         *pentry = entry;
 315         return 0;
 316 }
 317
 318 static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 319                             struct br_ip *group, unsigned char state)
 320 {
 321         struct net_bridge_mdb_entry *mp;
 322         struct net_bridge_port_group *p;
 323         struct net_bridge_port_group __rcu **pp;
 324         struct net_bridge_mdb_htable *mdb;
 325         int err;
 326
 327         mdb = mlock_dereference(br->mdb, br);
 328         mp = br_mdb_ip_get(mdb, group);
 329         if (!mp) {
 330                 mp = br_multicast_new_group(br, port, group);
 331                 err = PTR_ERR(mp);
 332                 if (IS_ERR(mp))
 333                         return err;
 334         }
 335
 336         for (pp = &mp->ports;
 337              (p = mlock_dereference(*pp, br)) != NULL;
 338              pp = &p->next) {
 339                 if (p->port == port)
 340                         return -EEXIST;
 341                 if ((unsigned long)p->port < (unsigned long)port)
 342                         break;
 343         }
 344
 345         p = br_multicast_new_port_group(port, group, *pp, state);
 346         if (unlikely(!p))
 347                 return -ENOMEM;
 348         rcu_assign_pointer(*pp, p);
 349
 350         br_mdb_notify(br->dev, port, group, RTM_NEWMDB);
 351         return 0;
 352 }
 353
 354 static int __br_mdb_add(struct net *net, struct net_bridge *br,
 355                         struct br_mdb_entry *entry)
 356 {
 357         struct br_ip ip;
 358         struct net_device *dev;
 359         struct net_bridge_port *p;
 360         int ret;
 361
 362         if (!netif_running(br->dev) || br->multicast_disabled)
 363                 return -EINVAL;
 364
 365         dev = __dev_get_by_index(net, entry->ifindex);
 366         if (!dev)
 367                 return -ENODEV;
 368
 369         p = br_port_get_rtnl(dev);
 370         if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 371                 return -EINVAL;
 372
 373         ip.proto = entry->addr.proto;
 374         if (ip.proto == htons(ETH_P_IP))
 375                 ip.u.ip4 = entry->addr.u.ip4;
 376 #if IS_ENABLED(CONFIG_IPV6)
 377         else
 378                 ip.u.ip6 = entry->addr.u.ip6;
 379 #endif
 380
 381         spin_lock_bh(&br->multicast_lock);
 382         ret = br_mdb_add_group(br, p, &ip, entry->state);
 383         spin_unlock_bh(&br->multicast_lock);
 384         return ret;
 385 }
 386
 387 static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
 388 {
 389         struct net *net = sock_net(skb->sk);
 390         struct br_mdb_entry *entry;
 391         struct net_device *dev;
 392         struct net_bridge *br;
 393         int err;
 394
 395         err = br_mdb_parse(skb, nlh, &dev, &entry);
 396         if (err < 0)
 397                 return err;
 398
 399         br = netdev_priv(dev);
 400
 401         err = __br_mdb_add(net, br, entry);
 402         if (!err)
 403                 __br_mdb_notify(dev, entry, RTM_NEWMDB);
 404         return err;
 405 }
 406
 407 static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
 408 {
 409         struct net_bridge_mdb_htable *mdb;
 410         struct net_bridge_mdb_entry *mp;
 411         struct net_bridge_port_group *p;
 412         struct net_bridge_port_group __rcu **pp;
 413         struct br_ip ip;
 414         int err = -EINVAL;
 415
 416         if (!netif_running(br->dev) || br->multicast_disabled)
 417                 return -EINVAL;
 418
 419         ip.proto = entry->addr.proto;
 420         if (ip.proto == htons(ETH_P_IP)) {
 421                 if (timer_pending(&br->ip4_querier.timer))
 422                         return -EBUSY;
 423
 424                 ip.u.ip4 = entry->addr.u.ip4;
 425 #if IS_ENABLED(CONFIG_IPV6)
 426         } else {
 427                 if (timer_pending(&br->ip6_querier.timer))
 428                         return -EBUSY;
 429
 430                 ip.u.ip6 = entry->addr.u.ip6;
 431 #endif
 432         }
 433
 434         spin_lock_bh(&br->multicast_lock);
 435         mdb = mlock_dereference(br->mdb, br);
 436
 437         mp = br_mdb_ip_get(mdb, &ip);
 438         if (!mp)
 439                 goto unlock;
 440
 441         for (pp = &mp->ports;
 442              (p = mlock_dereference(*pp, br)) != NULL;
 443              pp = &p->next) {
 444                 if (!p->port || p->port->dev->ifindex != entry->ifindex)
 445                         continue;
 446
 447                 if (p->port->state == BR_STATE_DISABLED)
 448                         goto unlock;
 449
 450                 rcu_assign_pointer(*pp, p->next);
 451                 hlist_del_init(&p->mglist);
 452                 del_timer(&p->timer);
 453                 call_rcu_bh(&p->rcu, br_multicast_free_pg);
 454                 err = 0;
 455
 456                 if (!mp->ports && !mp->mglist && mp->timer_armed &&
 457                     netif_running(br->dev))
 458                         mod_timer(&mp->timer, jiffies);
 459                 break;
 460         }
 461
 462 unlock:
 463         spin_unlock_bh(&br->multicast_lock);
 464         return err;
 465 }
 466
 467 static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
 468 {
 469         struct net_device *dev;
 470         struct br_mdb_entry *entry;
 471         struct net_bridge *br;
 472         int err;
 473
 474         err = br_mdb_parse(skb, nlh, &dev, &entry);
 475         if (err < 0)
 476                 return err;
 477
 478         br = netdev_priv(dev);
 479
 480         err = __br_mdb_del(br, entry);
 481         if (!err)
 482                 __br_mdb_notify(dev, entry, RTM_DELMDB);
 483         return err;
 484 }
 485
 486 void br_mdb_init(void)
 487 {
 488         rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
 489         rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
 490         rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
 491 }
 492
 493 void br_mdb_uninit(void)
 494 {
 495         rtnl_unregister(PF_BRIDGE, RTM_GETMDB);
 496         rtnl_unregister(PF_BRIDGE, RTM_NEWMDB);
 497         rtnl_unregister(PF_BRIDGE, RTM_DELMDB);
 498 }