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 #endif
  13
  14 #include "br_private.h"
  15
  16 static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
  17                                struct net_device *dev)
  18 {
  19         struct net_bridge *br = netdev_priv(dev);
  20         struct net_bridge_port *p;
  21         struct nlattr *nest;
  22
  23         if (!br->multicast_router || hlist_empty(&br->router_list))
  24                 return 0;
  25
  26         nest = nla_nest_start(skb, MDBA_ROUTER);
  27         if (nest == NULL)
  28                 return -EMSGSIZE;
  29
  30         hlist_for_each_entry_rcu(p, &br->router_list, rlist) {
  31                 if (p && nla_put_u32(skb, MDBA_ROUTER_PORT, p->dev->ifindex))
  32                         goto fail;
  33         }
  34
  35         nla_nest_end(skb, nest);
  36         return 0;
  37 fail:
  38         nla_nest_cancel(skb, nest);
  39         return -EMSGSIZE;
  40 }
  41
  42 static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
  43                             struct net_device *dev)
  44 {
  45         struct net_bridge *br = netdev_priv(dev);
  46         struct net_bridge_mdb_htable *mdb;
  47         struct nlattr *nest, *nest2;
  48         int i, err = 0;
  49         int idx = 0, s_idx = cb->args[1];
  50
  51         if (br->multicast_disabled)
  52                 return 0;
  53
  54         mdb = rcu_dereference(br->mdb);
  55         if (!mdb)
  56                 return 0;
  57
  58         nest = nla_nest_start(skb, MDBA_MDB);
  59         if (nest == NULL)
  60                 return -EMSGSIZE;
  61
  62         for (i = 0; i < mdb->max; i++) {
  63                 struct net_bridge_mdb_entry *mp;
  64                 struct net_bridge_port_group *p, **pp;
  65                 struct net_bridge_port *port;
  66
  67                 hlist_for_each_entry_rcu(mp, &mdb->mhash[i], hlist[mdb->ver]) {
  68                         if (idx < s_idx)
  69                                 goto skip;
  70
  71                         nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
  72                         if (nest2 == NULL) {
  73                                 err = -EMSGSIZE;
  74                                 goto out;
  75                         }
  76
  77                         for (pp = &mp->ports;
  78                              (p = rcu_dereference(*pp)) != NULL;
  79                               pp = &p->next) {
  80                                 port = p->port;
  81                                 if (port) {
  82                                         struct br_mdb_entry e;
  83                                         memset(&e, 0, sizeof(e));
  84                                         e.ifindex = port->dev->ifindex;
  85                                         e.state = p->state;
  86                                         if (p->addr.proto == htons(ETH_P_IP))
  87                                                 e.addr.u.ip4 = p->addr.u.ip4;
  88 #if IS_ENABLED(CONFIG_IPV6)
  89                                         if (p->addr.proto == htons(ETH_P_IPV6))
  90                                                 e.addr.u.ip6 = p->addr.u.ip6;
  91 #endif
  92                                         e.addr.proto = p->addr.proto;
  93                                         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {
  94                                                 nla_nest_cancel(skb, nest2);
  95                                                 err = -EMSGSIZE;
  96                                                 goto out;
  97                                         }
  98                                 }
  99                         }
 100                         nla_nest_end(skb, nest2);
 101                 skip:
 102                         idx++;
 103                 }
 104         }
 105
 106 out:
 107         cb->args[1] = idx;
 108         nla_nest_end(skb, nest);
 109         return err;
 110 }
 111
 112 static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 113 {
 114         struct net_device *dev;
 115         struct net *net = sock_net(skb->sk);
 116         struct nlmsghdr *nlh = NULL;
 117         int idx = 0, s_idx;
 118
 119         s_idx = cb->args[0];
 120
 121         rcu_read_lock();
 122
 123         /* In theory this could be wrapped to 0... */
 124         cb->seq = net->dev_base_seq + br_mdb_rehash_seq;
 125
 126         for_each_netdev_rcu(net, dev) {
 127                 if (dev->priv_flags & IFF_EBRIDGE) {
 128                         struct br_port_msg *bpm;
 129
 130                         if (idx < s_idx)
 131                                 goto skip;
 132
 133                         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
 134                                         cb->nlh->nlmsg_seq, RTM_GETMDB,
 135                                         sizeof(*bpm), NLM_F_MULTI);
 136                         if (nlh == NULL)
 137                                 break;
 138
 139                         bpm = nlmsg_data(nlh);
 140                         memset(bpm, 0, sizeof(*bpm));
 141                         bpm->ifindex = dev->ifindex;
 142                         if (br_mdb_fill_info(skb, cb, dev) < 0)
 143                                 goto out;
 144                         if (br_rports_fill_info(skb, cb, dev) < 0)
 145                                 goto out;
 146
 147                         cb->args[1] = 0;
 148                         nlmsg_end(skb, nlh);
 149                 skip:
 150                         idx++;
 151                 }
 152         }
 153
 154 out:
 155         if (nlh)
 156                 nlmsg_end(skb, nlh);
 157         rcu_read_unlock();
 158         cb->args[0] = idx;
 159         return skb->len;
 160 }
 161
 162 static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
 163                                    struct net_device *dev,
 164                                    struct br_mdb_entry *entry, u32 pid,
 165                                    u32 seq, int type, unsigned int flags)
 166 {
 167         struct nlmsghdr *nlh;
 168         struct br_port_msg *bpm;
 169         struct nlattr *nest, *nest2;
 170
 171         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), NLM_F_MULTI);
 172         if (!nlh)
 173                 return -EMSGSIZE;
 174
 175         bpm = nlmsg_data(nlh);
 176         memset(bpm, 0, sizeof(*bpm));
 177         bpm->family  = AF_BRIDGE;
 178         bpm->ifindex = dev->ifindex;
 179         nest = nla_nest_start(skb, MDBA_MDB);
 180         if (nest == NULL)
 181                 goto cancel;
 182         nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
 183         if (nest2 == NULL)
 184                 goto end;
 185
 186         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
 187                 goto end;
 188
 189         nla_nest_end(skb, nest2);
 190         nla_nest_end(skb, nest);
 191         return nlmsg_end(skb, nlh);
 192
 193 end:
 194         nla_nest_end(skb, nest);
 195 cancel:
 196         nlmsg_cancel(skb, nlh);
 197         return -EMSGSIZE;
 198 }
 199
 200 static inline size_t rtnl_mdb_nlmsg_size(void)
 201 {
 202         return NLMSG_ALIGN(sizeof(struct br_port_msg))
 203                 + nla_total_size(sizeof(struct br_mdb_entry));
 204 }
 205
 206 static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
 207                             int type)
 208 {
 209         struct net *net = dev_net(dev);
 210         struct sk_buff *skb;
 211         int err = -ENOBUFS;
 212
 213         skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
 214         if (!skb)
 215                 goto errout;
 216
 217         err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
 218         if (err < 0) {
 219                 kfree_skb(skb);
 220                 goto errout;
 221         }
 222
 223         rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
 224         return;
 225 errout:
 226         rtnl_set_sk_err(net, RTNLGRP_MDB, err);
 227 }
 228
 229 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
 230                    struct br_ip *group, int type)
 231 {
 232         struct br_mdb_entry entry;
 233
 234         memset(&entry, 0, sizeof(entry));
 235         entry.ifindex = port->dev->ifindex;
 236         entry.addr.proto = group->proto;
 237         entry.addr.u.ip4 = group->u.ip4;
 238 #if IS_ENABLED(CONFIG_IPV6)
 239         entry.addr.u.ip6 = group->u.ip6;
 240 #endif
 241         __br_mdb_notify(dev, &entry, type);
 242 }
 243
 244 static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
 245 {
 246         if (entry->ifindex == 0)
 247                 return false;
 248
 249         if (entry->addr.proto == htons(ETH_P_IP)) {
 250                 if (!ipv4_is_multicast(entry->addr.u.ip4))
 251                         return false;
 252                 if (ipv4_is_local_multicast(entry->addr.u.ip4))
 253                         return false;
 254 #if IS_ENABLED(CONFIG_IPV6)
 255         } else if (entry->addr.proto == htons(ETH_P_IPV6)) {
 256                 if (!ipv6_is_transient_multicast(&entry->addr.u.ip6))
 257                         return false;
 258 #endif
 259         } else
 260                 return false;
 261         if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
 262                 return false;
 263
 264         return true;
 265 }
 266
 267 static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
 268                         struct net_device **pdev, struct br_mdb_entry **pentry)
 269 {
 270         struct net *net = sock_net(skb->sk);
 271         struct br_mdb_entry *entry;
 272         struct br_port_msg *bpm;
 273         struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
 274         struct net_device *dev;
 275         int err;
 276
 277         err = nlmsg_parse(nlh, sizeof(*bpm), tb, MDBA_SET_ENTRY, NULL);
 278         if (err < 0)
 279                 return err;
 280
 281         bpm = nlmsg_data(nlh);
 282         if (bpm->ifindex == 0) {
 283                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid ifindex\n");
 284                 return -EINVAL;
 285         }
 286
 287         dev = __dev_get_by_index(net, bpm->ifindex);
 288         if (dev == NULL) {
 289                 pr_info("PF_BRIDGE: br_mdb_parse() with unknown ifindex\n");
 290                 return -ENODEV;
 291         }
 292
 293         if (!(dev->priv_flags & IFF_EBRIDGE)) {
 294                 pr_info("PF_BRIDGE: br_mdb_parse() with non-bridge\n");
 295                 return -EOPNOTSUPP;
 296         }
 297
 298         *pdev = dev;
 299
 300         if (!tb[MDBA_SET_ENTRY] ||
 301             nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
 302                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid attr\n");
 303                 return -EINVAL;
 304         }
 305
 306         entry = nla_data(tb[MDBA_SET_ENTRY]);
 307         if (!is_valid_mdb_entry(entry)) {
 308                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid entry\n");
 309                 return -EINVAL;
 310         }
 311
 312         *pentry = entry;
 313         return 0;
 314 }
 315
 316 static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 317                             struct br_ip *group, unsigned char state)
 318 {
 319         struct net_bridge_mdb_entry *mp;
 320         struct net_bridge_port_group *p;
 321         struct net_bridge_port_group __rcu **pp;
 322         struct net_bridge_mdb_htable *mdb;
 323         int err;
 324
 325         mdb = mlock_dereference(br->mdb, br);
 326         mp = br_mdb_ip_get(mdb, group);
 327         if (!mp) {
 328                 mp = br_multicast_new_group(br, port, group);
 329                 err = PTR_ERR(mp);
 330                 if (IS_ERR(mp))
 331                         return err;
 332         }
 333
 334         for (pp = &mp->ports;
 335              (p = mlock_dereference(*pp, br)) != NULL;
 336              pp = &p->next) {
 337                 if (p->port == port)
 338                         return -EEXIST;
 339                 if ((unsigned long)p->port < (unsigned long)port)
 340                         break;
 341         }
 342
 343         p = br_multicast_new_port_group(port, group, *pp, state);
 344         if (unlikely(!p))
 345                 return -ENOMEM;
 346         rcu_assign_pointer(*pp, p);
 347
 348         br_mdb_notify(br->dev, port, group, RTM_NEWMDB);
 349         return 0;
 350 }
 351
 352 static int __br_mdb_add(struct net *net, struct net_bridge *br,
 353                         struct br_mdb_entry *entry)
 354 {
 355         struct br_ip ip;
 356         struct net_device *dev;
 357         struct net_bridge_port *p;
 358         int ret;
 359
 360         if (!netif_running(br->dev) || br->multicast_disabled)
 361                 return -EINVAL;
 362
 363         dev = __dev_get_by_index(net, entry->ifindex);
 364         if (!dev)
 365                 return -ENODEV;
 366
 367         p = br_port_get_rtnl(dev);
 368         if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 369                 return -EINVAL;
 370
 371         ip.proto = entry->addr.proto;
 372         if (ip.proto == htons(ETH_P_IP))
 373                 ip.u.ip4 = entry->addr.u.ip4;
 374 #if IS_ENABLED(CONFIG_IPV6)
 375         else
 376                 ip.u.ip6 = entry->addr.u.ip6;
 377 #endif
 378
 379         spin_lock_bh(&br->multicast_lock);
 380         ret = br_mdb_add_group(br, p, &ip, entry->state);
 381         spin_unlock_bh(&br->multicast_lock);
 382         return ret;
 383 }
 384
 385 static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
 386 {
 387         struct net *net = sock_net(skb->sk);
 388         struct br_mdb_entry *entry;
 389         struct net_device *dev;
 390         struct net_bridge *br;
 391         int err;
 392
 393         err = br_mdb_parse(skb, nlh, &dev, &entry);
 394         if (err < 0)
 395                 return err;
 396
 397         br = netdev_priv(dev);
 398
 399         err = __br_mdb_add(net, br, entry);
 400         if (!err)
 401                 __br_mdb_notify(dev, entry, RTM_NEWMDB);
 402         return err;
 403 }
 404
 405 static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
 406 {
 407         struct net_bridge_mdb_htable *mdb;
 408         struct net_bridge_mdb_entry *mp;
 409         struct net_bridge_port_group *p;
 410         struct net_bridge_port_group __rcu **pp;
 411         struct br_ip ip;
 412         int err = -EINVAL;
 413
 414         if (!netif_running(br->dev) || br->multicast_disabled)
 415                 return -EINVAL;
 416
 417         if (timer_pending(&br->multicast_querier_timer))
 418                 return -EBUSY;
 419
 420         ip.proto = entry->addr.proto;
 421         if (ip.proto == htons(ETH_P_IP))
 422                 ip.u.ip4 = entry->addr.u.ip4;
 423 #if IS_ENABLED(CONFIG_IPV6)
 424         else
 425                 ip.u.ip6 = entry->addr.u.ip6;
 426 #endif
 427
 428         spin_lock_bh(&br->multicast_lock);
 429         mdb = mlock_dereference(br->mdb, br);
 430
 431         mp = br_mdb_ip_get(mdb, &ip);
 432         if (!mp)
 433                 goto unlock;
 434
 435         for (pp = &mp->ports;
 436              (p = mlock_dereference(*pp, br)) != NULL;
 437              pp = &p->next) {
 438                 if (!p->port || p->port->dev->ifindex != entry->ifindex)
 439                         continue;
 440
 441                 if (p->port->state == BR_STATE_DISABLED)
 442                         goto unlock;
 443
 444                 rcu_assign_pointer(*pp, p->next);
 445                 hlist_del_init(&p->mglist);
 446                 del_timer(&p->timer);
 447                 call_rcu_bh(&p->rcu, br_multicast_free_pg);
 448                 err = 0;
 449
 450                 if (!mp->ports && !mp->mglist && mp->timer_armed &&
 451                     netif_running(br->dev))
 452                         mod_timer(&mp->timer, jiffies);
 453                 break;
 454         }
 455
 456 unlock:
 457         spin_unlock_bh(&br->multicast_lock);
 458         return err;
 459 }
 460
 461 static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
 462 {
 463         struct net_device *dev;
 464         struct br_mdb_entry *entry;
 465         struct net_bridge *br;
 466         int err;
 467
 468         err = br_mdb_parse(skb, nlh, &dev, &entry);
 469         if (err < 0)
 470                 return err;
 471
 472         br = netdev_priv(dev);
 473
 474         err = __br_mdb_del(br, entry);
 475         if (!err)
 476                 __br_mdb_notify(dev, entry, RTM_DELMDB);
 477         return err;
 478 }
 479
 480 void br_mdb_init(void)
 481 {
 482         rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
 483         rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
 484         rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
 485 }
 486
 487 void br_mdb_uninit(void)
 488 {
 489         rtnl_unregister(PF_BRIDGE, RTM_GETMDB);
 490         rtnl_unregister(PF_BRIDGE, RTM_NEWMDB);
 491         rtnl_unregister(PF_BRIDGE, RTM_DELMDB);
 492 }