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                                         e.vid = p->addr.vid;
  89                                         if (p->addr.proto == htons(ETH_P_IP))
  90                                                 e.addr.u.ip4 = p->addr.u.ip4;
  91 #if IS_ENABLED(CONFIG_IPV6)
  92                                         if (p->addr.proto == htons(ETH_P_IPV6))
  93                                                 e.addr.u.ip6 = p->addr.u.ip6;
  94 #endif
  95                                         e.addr.proto = p->addr.proto;
  96                                         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {
  97                                                 nla_nest_cancel(skb, nest2);
  98                                                 err = -EMSGSIZE;
  99                                                 goto out;
 100                                         }
 101                                 }
 102                         }
 103                         nla_nest_end(skb, nest2);
 104                 skip:
 105                         idx++;
 106                 }
 107         }
 108
 109 out:
 110         cb->args[1] = idx;
 111         nla_nest_end(skb, nest);
 112         return err;
 113 }
 114
 115 static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
 116 {
 117         struct net_device *dev;
 118         struct net *net = sock_net(skb->sk);
 119         struct nlmsghdr *nlh = NULL;
 120         int idx = 0, s_idx;
 121
 122         s_idx = cb->args[0];
 123
 124         rcu_read_lock();
 125
 126         /* In theory this could be wrapped to 0... */
 127         cb->seq = net->dev_base_seq + br_mdb_rehash_seq;
 128
 129         for_each_netdev_rcu(net, dev) {
 130                 if (dev->priv_flags & IFF_EBRIDGE) {
 131                         struct br_port_msg *bpm;
 132
 133                         if (idx < s_idx)
 134                                 goto skip;
 135
 136                         nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
 137                                         cb->nlh->nlmsg_seq, RTM_GETMDB,
 138                                         sizeof(*bpm), NLM_F_MULTI);
 139                         if (nlh == NULL)
 140                                 break;
 141
 142                         bpm = nlmsg_data(nlh);
 143                         memset(bpm, 0, sizeof(*bpm));
 144                         bpm->ifindex = dev->ifindex;
 145                         if (br_mdb_fill_info(skb, cb, dev) < 0)
 146                                 goto out;
 147                         if (br_rports_fill_info(skb, cb, dev) < 0)
 148                                 goto out;
 149
 150                         cb->args[1] = 0;
 151                         nlmsg_end(skb, nlh);
 152                 skip:
 153                         idx++;
 154                 }
 155         }
 156
 157 out:
 158         if (nlh)
 159                 nlmsg_end(skb, nlh);
 160         rcu_read_unlock();
 161         cb->args[0] = idx;
 162         return skb->len;
 163 }
 164
 165 static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
 166                                    struct net_device *dev,
 167                                    struct br_mdb_entry *entry, u32 pid,
 168                                    u32 seq, int type, unsigned int flags)
 169 {
 170         struct nlmsghdr *nlh;
 171         struct br_port_msg *bpm;
 172         struct nlattr *nest, *nest2;
 173
 174         nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), 0);
 175         if (!nlh)
 176                 return -EMSGSIZE;
 177
 178         bpm = nlmsg_data(nlh);
 179         memset(bpm, 0, sizeof(*bpm));
 180         bpm->family  = AF_BRIDGE;
 181         bpm->ifindex = dev->ifindex;
 182         nest = nla_nest_start(skb, MDBA_MDB);
 183         if (nest == NULL)
 184                 goto cancel;
 185         nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);
 186         if (nest2 == NULL)
 187                 goto end;
 188
 189         if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
 190                 goto end;
 191
 192         nla_nest_end(skb, nest2);
 193         nla_nest_end(skb, nest);
 194         nlmsg_end(skb, nlh);
 195         return 0;
 196
 197 end:
 198         nla_nest_end(skb, nest);
 199 cancel:
 200         nlmsg_cancel(skb, nlh);
 201         return -EMSGSIZE;
 202 }
 203
 204 static inline size_t rtnl_mdb_nlmsg_size(void)
 205 {
 206         return NLMSG_ALIGN(sizeof(struct br_port_msg))
 207                 + nla_total_size(sizeof(struct br_mdb_entry));
 208 }
 209
 210 static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
 211                             int type)
 212 {
 213         struct net *net = dev_net(dev);
 214         struct sk_buff *skb;
 215         int err = -ENOBUFS;
 216
 217         skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
 218         if (!skb)
 219                 goto errout;
 220
 221         err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
 222         if (err < 0) {
 223                 kfree_skb(skb);
 224                 goto errout;
 225         }
 226
 227         rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
 228         return;
 229 errout:
 230         rtnl_set_sk_err(net, RTNLGRP_MDB, err);
 231 }
 232
 233 void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
 234                    struct br_ip *group, int type, u8 state)
 235 {
 236         struct br_mdb_entry entry;
 237
 238         memset(&entry, 0, sizeof(entry));
 239         entry.ifindex = port->dev->ifindex;
 240         entry.addr.proto = group->proto;
 241         entry.addr.u.ip4 = group->u.ip4;
 242 #if IS_ENABLED(CONFIG_IPV6)
 243         entry.addr.u.ip6 = group->u.ip6;
 244 #endif
 245         entry.state = state;
 246         entry.vid = group->vid;
 247         __br_mdb_notify(dev, &entry, type);
 248 }
 249
 250 static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
 251 {
 252         if (entry->ifindex == 0)
 253                 return false;
 254
 255         if (entry->addr.proto == htons(ETH_P_IP)) {
 256                 if (!ipv4_is_multicast(entry->addr.u.ip4))
 257                         return false;
 258                 if (ipv4_is_local_multicast(entry->addr.u.ip4))
 259                         return false;
 260 #if IS_ENABLED(CONFIG_IPV6)
 261         } else if (entry->addr.proto == htons(ETH_P_IPV6)) {
 262                 if (ipv6_addr_is_ll_all_nodes(&entry->addr.u.ip6))
 263                         return false;
 264 #endif
 265         } else
 266                 return false;
 267         if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
 268                 return false;
 269         if (entry->vid >= VLAN_VID_MASK)
 270                 return false;
 271
 272         return true;
 273 }
 274
 275 static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
 276                         struct net_device **pdev, struct br_mdb_entry **pentry)
 277 {
 278         struct net *net = sock_net(skb->sk);
 279         struct br_mdb_entry *entry;
 280         struct br_port_msg *bpm;
 281         struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
 282         struct net_device *dev;
 283         int err;
 284
 285         err = nlmsg_parse(nlh, sizeof(*bpm), tb, MDBA_SET_ENTRY_MAX, NULL);
 286         if (err < 0)
 287                 return err;
 288
 289         bpm = nlmsg_data(nlh);
 290         if (bpm->ifindex == 0) {
 291                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid ifindex\n");
 292                 return -EINVAL;
 293         }
 294
 295         dev = __dev_get_by_index(net, bpm->ifindex);
 296         if (dev == NULL) {
 297                 pr_info("PF_BRIDGE: br_mdb_parse() with unknown ifindex\n");
 298                 return -ENODEV;
 299         }
 300
 301         if (!(dev->priv_flags & IFF_EBRIDGE)) {
 302                 pr_info("PF_BRIDGE: br_mdb_parse() with non-bridge\n");
 303                 return -EOPNOTSUPP;
 304         }
 305
 306         *pdev = dev;
 307
 308         if (!tb[MDBA_SET_ENTRY] ||
 309             nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
 310                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid attr\n");
 311                 return -EINVAL;
 312         }
 313
 314         entry = nla_data(tb[MDBA_SET_ENTRY]);
 315         if (!is_valid_mdb_entry(entry)) {
 316                 pr_info("PF_BRIDGE: br_mdb_parse() with invalid entry\n");
 317                 return -EINVAL;
 318         }
 319
 320         *pentry = entry;
 321         return 0;
 322 }
 323
 324 static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
 325                             struct br_ip *group, unsigned char state)
 326 {
 327         struct net_bridge_mdb_entry *mp;
 328         struct net_bridge_port_group *p;
 329         struct net_bridge_port_group __rcu **pp;
 330         struct net_bridge_mdb_htable *mdb;
 331         unsigned long now = jiffies;
 332         int err;
 333
 334         mdb = mlock_dereference(br->mdb, br);
 335         mp = br_mdb_ip_get(mdb, group);
 336         if (!mp) {
 337                 mp = br_multicast_new_group(br, port, group);
 338                 err = PTR_ERR(mp);
 339                 if (IS_ERR(mp))
 340                         return err;
 341         }
 342
 343         for (pp = &mp->ports;
 344              (p = mlock_dereference(*pp, br)) != NULL;
 345              pp = &p->next) {
 346                 if (p->port == port)
 347                         return -EEXIST;
 348                 if ((unsigned long)p->port < (unsigned long)port)
 349                         break;
 350         }
 351
 352         p = br_multicast_new_port_group(port, group, *pp, state);
 353         if (unlikely(!p))
 354                 return -ENOMEM;
 355         rcu_assign_pointer(*pp, p);
 356         if (state == MDB_TEMPORARY)
 357                 mod_timer(&p->timer, now + br->multicast_membership_interval);
 358
 359         br_mdb_notify(br->dev, port, group, RTM_NEWMDB, state);
 360         return 0;
 361 }
 362
 363 static int __br_mdb_add(struct net *net, struct net_bridge *br,
 364                         struct br_mdb_entry *entry)
 365 {
 366         struct br_ip ip;
 367         struct net_device *dev;
 368         struct net_bridge_port *p;
 369         int ret;
 370
 371         if (!netif_running(br->dev) || br->multicast_disabled)
 372                 return -EINVAL;
 373
 374         dev = __dev_get_by_index(net, entry->ifindex);
 375         if (!dev)
 376                 return -ENODEV;
 377
 378         p = br_port_get_rtnl(dev);
 379         if (!p || p->br != br || p->state == BR_STATE_DISABLED)
 380                 return -EINVAL;
 381
 382         memset(&ip, 0, sizeof(ip));
 383         ip.vid = entry->vid;
 384         ip.proto = entry->addr.proto;
 385         if (ip.proto == htons(ETH_P_IP))
 386                 ip.u.ip4 = entry->addr.u.ip4;
 387 #if IS_ENABLED(CONFIG_IPV6)
 388         else
 389                 ip.u.ip6 = entry->addr.u.ip6;
 390 #endif
 391
 392         spin_lock_bh(&br->multicast_lock);
 393         ret = br_mdb_add_group(br, p, &ip, entry->state);
 394         spin_unlock_bh(&br->multicast_lock);
 395         return ret;
 396 }
 397
 398 static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
 399 {
 400         struct net *net = sock_net(skb->sk);
 401         struct br_mdb_entry *entry;
 402         struct net_device *dev;
 403         struct net_bridge *br;
 404         int err;
 405
 406         err = br_mdb_parse(skb, nlh, &dev, &entry);
 407         if (err < 0)
 408                 return err;
 409
 410         br = netdev_priv(dev);
 411
 412         err = __br_mdb_add(net, br, entry);
 413         if (!err)
 414                 __br_mdb_notify(dev, entry, RTM_NEWMDB);
 415         return err;
 416 }
 417
 418 static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
 419 {
 420         struct net_bridge_mdb_htable *mdb;
 421         struct net_bridge_mdb_entry *mp;
 422         struct net_bridge_port_group *p;
 423         struct net_bridge_port_group __rcu **pp;
 424         struct br_ip ip;
 425         int err = -EINVAL;
 426
 427         if (!netif_running(br->dev) || br->multicast_disabled)
 428                 return -EINVAL;
 429
 430         memset(&ip, 0, sizeof(ip));
 431         ip.vid = entry->vid;
 432         ip.proto = entry->addr.proto;
 433         if (ip.proto == htons(ETH_P_IP))
 434                 ip.u.ip4 = entry->addr.u.ip4;
 435 #if IS_ENABLED(CONFIG_IPV6)
 436         else
 437                 ip.u.ip6 = entry->addr.u.ip6;
 438 #endif
 439
 440         spin_lock_bh(&br->multicast_lock);
 441         mdb = mlock_dereference(br->mdb, br);
 442
 443         mp = br_mdb_ip_get(mdb, &ip);
 444         if (!mp)
 445                 goto unlock;
 446
 447         for (pp = &mp->ports;
 448              (p = mlock_dereference(*pp, br)) != NULL;
 449              pp = &p->next) {
 450                 if (!p->port || p->port->dev->ifindex != entry->ifindex)
 451                         continue;
 452
 453                 if (p->port->state == BR_STATE_DISABLED)
 454                         goto unlock;
 455
 456                 rcu_assign_pointer(*pp, p->next);
 457                 hlist_del_init(&p->mglist);
 458                 del_timer(&p->timer);
 459                 call_rcu_bh(&p->rcu, br_multicast_free_pg);
 460                 err = 0;
 461
 462                 if (!mp->ports && !mp->mglist &&
 463                     netif_running(br->dev))
 464                         mod_timer(&mp->timer, jiffies);
 465                 break;
 466         }
 467
 468 unlock:
 469         spin_unlock_bh(&br->multicast_lock);
 470         return err;
 471 }
 472
 473 static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
 474 {
 475         struct net_device *dev;
 476         struct br_mdb_entry *entry;
 477         struct net_bridge *br;
 478         int err;
 479
 480         err = br_mdb_parse(skb, nlh, &dev, &entry);
 481         if (err < 0)
 482                 return err;
 483
 484         br = netdev_priv(dev);
 485
 486         err = __br_mdb_del(br, entry);
 487         if (!err)
 488                 __br_mdb_notify(dev, entry, RTM_DELMDB);
 489         return err;
 490 }
 491
 492 void br_mdb_init(void)
 493 {
 494         rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
 495         rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
 496         rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
 497 }
 498
 499 void br_mdb_uninit(void)
 500 {
 501         rtnl_unregister(PF_BRIDGE, RTM_GETMDB);
 502         rtnl_unregister(PF_BRIDGE, RTM_NEWMDB);
 503         rtnl_unregister(PF_BRIDGE, RTM_DELMDB);
 504 }