net/batman-adv/multicast.c

   1 /* Copyright (C) 2014-2015 B.A.T.M.A.N. contributors:
   2  *
   3  * Linus Lüssing
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "multicast.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/bitops.h>
  23 #include <linux/bug.h>
  24 #include <linux/byteorder/generic.h>
  25 #include <linux/errno.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/fs.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/in6.h>
  30 #include <linux/in.h>
  31 #include <linux/ip.h>
  32 #include <linux/ipv6.h>
  33 #include <linux/list.h>
  34 #include <linux/lockdep.h>
  35 #include <linux/netdevice.h>
  36 #include <linux/rculist.h>
  37 #include <linux/rcupdate.h>
  38 #include <linux/skbuff.h>
  39 #include <linux/slab.h>
  40 #include <linux/spinlock.h>
  41 #include <linux/stddef.h>
  42 #include <linux/string.h>
  43 #include <linux/types.h>
  44 #include <net/addrconf.h>
  45 #include <net/ipv6.h>
  46
  47 #include "packet.h"
  48 #include "translation-table.h"
  49
  50 /**
  51  * batadv_mcast_mla_softif_get - get softif multicast listeners
  52  * @dev: the device to collect multicast addresses from
  53  * @mcast_list: a list to put found addresses into
  54  *
  55  * Collect multicast addresses of the local multicast listeners
  56  * on the given soft interface, dev, in the given mcast_list.
  57  *
  58  * Returns -ENOMEM on memory allocation error or the number of
  59  * items added to the mcast_list otherwise.
  60  */
  61 static int batadv_mcast_mla_softif_get(struct net_device *dev,
  62                                        struct hlist_head *mcast_list)
  63 {
  64         struct netdev_hw_addr *mc_list_entry;
  65         struct batadv_hw_addr *new;
  66         int ret = 0;
  67
  68         netif_addr_lock_bh(dev);
  69         netdev_for_each_mc_addr(mc_list_entry, dev) {
  70                 new = kmalloc(sizeof(*new), GFP_ATOMIC);
  71                 if (!new) {
  72                         ret = -ENOMEM;
  73                         break;
  74                 }
  75
  76                 ether_addr_copy(new->addr, mc_list_entry->addr);
  77                 hlist_add_head(&new->list, mcast_list);
  78                 ret++;
  79         }
  80         netif_addr_unlock_bh(dev);
  81
  82         return ret;
  83 }
  84
  85 /**
  86  * batadv_mcast_mla_is_duplicate - check whether an address is in a list
  87  * @mcast_addr: the multicast address to check
  88  * @mcast_list: the list with multicast addresses to search in
  89  *
  90  * Returns true if the given address is already in the given list.
  91  * Otherwise returns false.
  92  */
  93 static bool batadv_mcast_mla_is_duplicate(u8 *mcast_addr,
  94                                           struct hlist_head *mcast_list)
  95 {
  96         struct batadv_hw_addr *mcast_entry;
  97
  98         hlist_for_each_entry(mcast_entry, mcast_list, list)
  99                 if (batadv_compare_eth(mcast_entry->addr, mcast_addr))
 100                         return true;
 101
 102         return false;
 103 }
 104
 105 /**
 106  * batadv_mcast_mla_list_free - free a list of multicast addresses
 107  * @bat_priv: the bat priv with all the soft interface information
 108  * @mcast_list: the list to free
 109  *
 110  * Removes and frees all items in the given mcast_list.
 111  */
 112 static void batadv_mcast_mla_list_free(struct batadv_priv *bat_priv,
 113                                        struct hlist_head *mcast_list)
 114 {
 115         struct batadv_hw_addr *mcast_entry;
 116         struct hlist_node *tmp;
 117
 118         lockdep_assert_held(&bat_priv->tt.commit_lock);
 119
 120         hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
 121                 hlist_del(&mcast_entry->list);
 122                 kfree(mcast_entry);
 123         }
 124 }
 125
 126 /**
 127  * batadv_mcast_mla_tt_retract - clean up multicast listener announcements
 128  * @bat_priv: the bat priv with all the soft interface information
 129  * @mcast_list: a list of addresses which should _not_ be removed
 130  *
 131  * Retracts the announcement of any multicast listener from the
 132  * translation table except the ones listed in the given mcast_list.
 133  *
 134  * If mcast_list is NULL then all are retracted.
 135  */
 136 static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
 137                                         struct hlist_head *mcast_list)
 138 {
 139         struct batadv_hw_addr *mcast_entry;
 140         struct hlist_node *tmp;
 141
 142         lockdep_assert_held(&bat_priv->tt.commit_lock);
 143
 144         hlist_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list,
 145                                   list) {
 146                 if (mcast_list &&
 147                     batadv_mcast_mla_is_duplicate(mcast_entry->addr,
 148                                                   mcast_list))
 149                         continue;
 150
 151                 batadv_tt_local_remove(bat_priv, mcast_entry->addr,
 152                                        BATADV_NO_FLAGS,
 153                                        "mcast TT outdated", false);
 154
 155                 hlist_del(&mcast_entry->list);
 156                 kfree(mcast_entry);
 157         }
 158 }
 159
 160 /**
 161  * batadv_mcast_mla_tt_add - add multicast listener announcements
 162  * @bat_priv: the bat priv with all the soft interface information
 163  * @mcast_list: a list of addresses which are going to get added
 164  *
 165  * Adds multicast listener announcements from the given mcast_list to the
 166  * translation table if they have not been added yet.
 167  */
 168 static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
 169                                     struct hlist_head *mcast_list)
 170 {
 171         struct batadv_hw_addr *mcast_entry;
 172         struct hlist_node *tmp;
 173
 174         lockdep_assert_held(&bat_priv->tt.commit_lock);
 175
 176         if (!mcast_list)
 177                 return;
 178
 179         hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
 180                 if (batadv_mcast_mla_is_duplicate(mcast_entry->addr,
 181                                                   &bat_priv->mcast.mla_list))
 182                         continue;
 183
 184                 if (!batadv_tt_local_add(bat_priv->soft_iface,
 185                                          mcast_entry->addr, BATADV_NO_FLAGS,
 186                                          BATADV_NULL_IFINDEX, BATADV_NO_MARK))
 187                         continue;
 188
 189                 hlist_del(&mcast_entry->list);
 190                 hlist_add_head(&mcast_entry->list, &bat_priv->mcast.mla_list);
 191         }
 192 }
 193
 194 /**
 195  * batadv_mcast_has_bridge - check whether the soft-iface is bridged
 196  * @bat_priv: the bat priv with all the soft interface information
 197  *
 198  * Checks whether there is a bridge on top of our soft interface. Returns
 199  * true if so, false otherwise.
 200  */
 201 static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv)
 202 {
 203         struct net_device *upper = bat_priv->soft_iface;
 204
 205         rcu_read_lock();
 206         do {
 207                 upper = netdev_master_upper_dev_get_rcu(upper);
 208         } while (upper && !(upper->priv_flags & IFF_EBRIDGE));
 209         rcu_read_unlock();
 210
 211         return upper;
 212 }
 213
 214 /**
 215  * batadv_mcast_mla_tvlv_update - update multicast tvlv
 216  * @bat_priv: the bat priv with all the soft interface information
 217  *
 218  * Updates the own multicast tvlv with our current multicast related settings,
 219  * capabilities and inabilities.
 220  *
 221  * Returns true if the tvlv container is registered afterwards. Otherwise
 222  * returns false.
 223  */
 224 static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv)
 225 {
 226         struct batadv_tvlv_mcast_data mcast_data;
 227
 228         mcast_data.flags = BATADV_NO_FLAGS;
 229         memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));
 230
 231         /* Avoid attaching MLAs, if there is a bridge on top of our soft
 232          * interface, we don't support that yet (TODO)
 233          */
 234         if (batadv_mcast_has_bridge(bat_priv)) {
 235                 if (bat_priv->mcast.enabled) {
 236                         batadv_tvlv_container_unregister(bat_priv,
 237                                                          BATADV_TVLV_MCAST, 1);
 238                         bat_priv->mcast.enabled = false;
 239                 }
 240
 241                 return false;
 242         }
 243
 244         if (!bat_priv->mcast.enabled ||
 245             mcast_data.flags != bat_priv->mcast.flags) {
 246                 batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 1,
 247                                                &mcast_data, sizeof(mcast_data));
 248                 bat_priv->mcast.flags = mcast_data.flags;
 249                 bat_priv->mcast.enabled = true;
 250         }
 251
 252         return true;
 253 }
 254
 255 /**
 256  * batadv_mcast_mla_update - update the own MLAs
 257  * @bat_priv: the bat priv with all the soft interface information
 258  *
 259  * Updates the own multicast listener announcements in the translation
 260  * table as well as the own, announced multicast tvlv container.
 261  */
 262 void batadv_mcast_mla_update(struct batadv_priv *bat_priv)
 263 {
 264         struct net_device *soft_iface = bat_priv->soft_iface;
 265         struct hlist_head mcast_list = HLIST_HEAD_INIT;
 266         int ret;
 267
 268         if (!batadv_mcast_mla_tvlv_update(bat_priv))
 269                 goto update;
 270
 271         ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list);
 272         if (ret < 0)
 273                 goto out;
 274
 275 update:
 276         batadv_mcast_mla_tt_retract(bat_priv, &mcast_list);
 277         batadv_mcast_mla_tt_add(bat_priv, &mcast_list);
 278
 279 out:
 280         batadv_mcast_mla_list_free(bat_priv, &mcast_list);
 281 }
 282
 283 /**
 284  * batadv_mcast_forw_mode_check_ipv4 - check for optimized forwarding potential
 285  * @bat_priv: the bat priv with all the soft interface information
 286  * @skb: the IPv4 packet to check
 287  * @is_unsnoopable: stores whether the destination is snoopable
 288  *
 289  * Checks whether the given IPv4 packet has the potential to be forwarded with a
 290  * mode more optimal than classic flooding.
 291  *
 292  * If so then returns 0. Otherwise -EINVAL is returned or -ENOMEM in case of
 293  * memory allocation failure.
 294  */
 295 static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv,
 296                                              struct sk_buff *skb,
 297                                              bool *is_unsnoopable)
 298 {
 299         struct iphdr *iphdr;
 300
 301         /* We might fail due to out-of-memory -> drop it */
 302         if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*iphdr)))
 303                 return -ENOMEM;
 304
 305         iphdr = ip_hdr(skb);
 306
 307         /* TODO: Implement Multicast Router Discovery (RFC4286),
 308          * then allow scope > link local, too
 309          */
 310         if (!ipv4_is_local_multicast(iphdr->daddr))
 311                 return -EINVAL;
 312
 313         /* link-local multicast listeners behind a bridge are
 314          * not snoopable (see RFC4541, section 2.1.2.2)
 315          */
 316         *is_unsnoopable = true;
 317
 318         return 0;
 319 }
 320
 321 /**
 322  * batadv_mcast_forw_mode_check_ipv6 - check for optimized forwarding potential
 323  * @bat_priv: the bat priv with all the soft interface information
 324  * @skb: the IPv6 packet to check
 325  * @is_unsnoopable: stores whether the destination is snoopable
 326  *
 327  * Checks whether the given IPv6 packet has the potential to be forwarded with a
 328  * mode more optimal than classic flooding.
 329  *
 330  * If so then returns 0. Otherwise -EINVAL is returned or -ENOMEM if we are out
 331  * of memory.
 332  */
 333 static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv,
 334                                              struct sk_buff *skb,
 335                                              bool *is_unsnoopable)
 336 {
 337         struct ipv6hdr *ip6hdr;
 338
 339         /* We might fail due to out-of-memory -> drop it */
 340         if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*ip6hdr)))
 341                 return -ENOMEM;
 342
 343         ip6hdr = ipv6_hdr(skb);
 344
 345         /* TODO: Implement Multicast Router Discovery (RFC4286),
 346          * then allow scope > link local, too
 347          */
 348         if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) != IPV6_ADDR_SCOPE_LINKLOCAL)
 349                 return -EINVAL;
 350
 351         /* link-local-all-nodes multicast listeners behind a bridge are
 352          * not snoopable (see RFC4541, section 3, paragraph 3)
 353          */
 354         if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr))
 355                 *is_unsnoopable = true;
 356
 357         return 0;
 358 }
 359
 360 /**
 361  * batadv_mcast_forw_mode_check - check for optimized forwarding potential
 362  * @bat_priv: the bat priv with all the soft interface information
 363  * @skb: the multicast frame to check
 364  * @is_unsnoopable: stores whether the destination is snoopable
 365  *
 366  * Checks whether the given multicast ethernet frame has the potential to be
 367  * forwarded with a mode more optimal than classic flooding.
 368  *
 369  * If so then returns 0. Otherwise -EINVAL is returned or -ENOMEM if we are out
 370  * of memory.
 371  */
 372 static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv,
 373                                         struct sk_buff *skb,
 374                                         bool *is_unsnoopable)
 375 {
 376         struct ethhdr *ethhdr = eth_hdr(skb);
 377
 378         if (!atomic_read(&bat_priv->multicast_mode))
 379                 return -EINVAL;
 380
 381         if (atomic_read(&bat_priv->mcast.num_disabled))
 382                 return -EINVAL;
 383
 384         switch (ntohs(ethhdr->h_proto)) {
 385         case ETH_P_IP:
 386                 return batadv_mcast_forw_mode_check_ipv4(bat_priv, skb,
 387                                                          is_unsnoopable);
 388         case ETH_P_IPV6:
 389                 return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb,
 390                                                          is_unsnoopable);
 391         default:
 392                 return -EINVAL;
 393         }
 394 }
 395
 396 /**
 397  * batadv_mcast_want_all_ip_count - count nodes with unspecific mcast interest
 398  * @bat_priv: the bat priv with all the soft interface information
 399  * @ethhdr: ethernet header of a packet
 400  *
 401  * Returns the number of nodes which want all IPv4 multicast traffic if the
 402  * given ethhdr is from an IPv4 packet or the number of nodes which want all
 403  * IPv6 traffic if it matches an IPv6 packet.
 404  */
 405 static int batadv_mcast_forw_want_all_ip_count(struct batadv_priv *bat_priv,
 406                                                struct ethhdr *ethhdr)
 407 {
 408         switch (ntohs(ethhdr->h_proto)) {
 409         case ETH_P_IP:
 410                 return atomic_read(&bat_priv->mcast.num_want_all_ipv4);
 411         case ETH_P_IPV6:
 412                 return atomic_read(&bat_priv->mcast.num_want_all_ipv6);
 413         default:
 414                 /* we shouldn't be here... */
 415                 return 0;
 416         }
 417 }
 418
 419 /**
 420  * batadv_mcast_forw_tt_node_get - get a multicast tt node
 421  * @bat_priv: the bat priv with all the soft interface information
 422  * @ethhdr: the ether header containing the multicast destination
 423  *
 424  * Returns an orig_node matching the multicast address provided by ethhdr
 425  * via a translation table lookup. This increases the returned nodes refcount.
 426  */
 427 static struct batadv_orig_node *
 428 batadv_mcast_forw_tt_node_get(struct batadv_priv *bat_priv,
 429                               struct ethhdr *ethhdr)
 430 {
 431         return batadv_transtable_search(bat_priv, ethhdr->h_source,
 432                                         ethhdr->h_dest, BATADV_NO_FLAGS);
 433 }
 434
 435 /**
 436  * batadv_mcast_want_forw_ipv4_node_get - get a node with an ipv4 flag
 437  * @bat_priv: the bat priv with all the soft interface information
 438  *
 439  * Returns an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 flag set and
 440  * increases its refcount.
 441  */
 442 static struct batadv_orig_node *
 443 batadv_mcast_forw_ipv4_node_get(struct batadv_priv *bat_priv)
 444 {
 445         struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
 446
 447         rcu_read_lock();
 448         hlist_for_each_entry_rcu(tmp_orig_node,
 449                                  &bat_priv->mcast.want_all_ipv4_list,
 450                                  mcast_want_all_ipv4_node) {
 451                 if (!atomic_inc_not_zero(&tmp_orig_node->refcount))
 452                         continue;
 453
 454                 orig_node = tmp_orig_node;
 455                 break;
 456         }
 457         rcu_read_unlock();
 458
 459         return orig_node;
 460 }
 461
 462 /**
 463  * batadv_mcast_want_forw_ipv6_node_get - get a node with an ipv6 flag
 464  * @bat_priv: the bat priv with all the soft interface information
 465  *
 466  * Returns an orig_node which has the BATADV_MCAST_WANT_ALL_IPV6 flag set
 467  * and increases its refcount.
 468  */
 469 static struct batadv_orig_node *
 470 batadv_mcast_forw_ipv6_node_get(struct batadv_priv *bat_priv)
 471 {
 472         struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
 473
 474         rcu_read_lock();
 475         hlist_for_each_entry_rcu(tmp_orig_node,
 476                                  &bat_priv->mcast.want_all_ipv6_list,
 477                                  mcast_want_all_ipv6_node) {
 478                 if (!atomic_inc_not_zero(&tmp_orig_node->refcount))
 479                         continue;
 480
 481                 orig_node = tmp_orig_node;
 482                 break;
 483         }
 484         rcu_read_unlock();
 485
 486         return orig_node;
 487 }
 488
 489 /**
 490  * batadv_mcast_want_forw_ip_node_get - get a node with an ipv4/ipv6 flag
 491  * @bat_priv: the bat priv with all the soft interface information
 492  * @ethhdr: an ethernet header to determine the protocol family from
 493  *
 494  * Returns an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 or
 495  * BATADV_MCAST_WANT_ALL_IPV6 flag, depending on the provided ethhdr, set and
 496  * increases its refcount.
 497  */
 498 static struct batadv_orig_node *
 499 batadv_mcast_forw_ip_node_get(struct batadv_priv *bat_priv,
 500                               struct ethhdr *ethhdr)
 501 {
 502         switch (ntohs(ethhdr->h_proto)) {
 503         case ETH_P_IP:
 504                 return batadv_mcast_forw_ipv4_node_get(bat_priv);
 505         case ETH_P_IPV6:
 506                 return batadv_mcast_forw_ipv6_node_get(bat_priv);
 507         default:
 508                 /* we shouldn't be here... */
 509                 return NULL;
 510         }
 511 }
 512
 513 /**
 514  * batadv_mcast_want_forw_unsnoop_node_get - get a node with an unsnoopable flag
 515  * @bat_priv: the bat priv with all the soft interface information
 516  *
 517  * Returns an orig_node which has the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag
 518  * set and increases its refcount.
 519  */
 520 static struct batadv_orig_node *
 521 batadv_mcast_forw_unsnoop_node_get(struct batadv_priv *bat_priv)
 522 {
 523         struct batadv_orig_node *tmp_orig_node, *orig_node = NULL;
 524
 525         rcu_read_lock();
 526         hlist_for_each_entry_rcu(tmp_orig_node,
 527                                  &bat_priv->mcast.want_all_unsnoopables_list,
 528                                  mcast_want_all_unsnoopables_node) {
 529                 if (!atomic_inc_not_zero(&tmp_orig_node->refcount))
 530                         continue;
 531
 532                 orig_node = tmp_orig_node;
 533                 break;
 534         }
 535         rcu_read_unlock();
 536
 537         return orig_node;
 538 }
 539
 540 /**
 541  * batadv_mcast_forw_mode - check on how to forward a multicast packet
 542  * @bat_priv: the bat priv with all the soft interface information
 543  * @skb: The multicast packet to check
 544  * @orig: an originator to be set to forward the skb to
 545  *
 546  * Returns the forwarding mode as enum batadv_forw_mode and in case of
 547  * BATADV_FORW_SINGLE set the orig to the single originator the skb
 548  * should be forwarded to.
 549  */
 550 enum batadv_forw_mode
 551 batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
 552                        struct batadv_orig_node **orig)
 553 {
 554         int ret, tt_count, ip_count, unsnoop_count, total_count;
 555         bool is_unsnoopable = false;
 556         struct ethhdr *ethhdr;
 557
 558         ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable);
 559         if (ret == -ENOMEM)
 560                 return BATADV_FORW_NONE;
 561         else if (ret < 0)
 562                 return BATADV_FORW_ALL;
 563
 564         ethhdr = eth_hdr(skb);
 565
 566         tt_count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest,
 567                                                BATADV_NO_FLAGS);
 568         ip_count = batadv_mcast_forw_want_all_ip_count(bat_priv, ethhdr);
 569         unsnoop_count = !is_unsnoopable ? 0 :
 570                         atomic_read(&bat_priv->mcast.num_want_all_unsnoopables);
 571
 572         total_count = tt_count + ip_count + unsnoop_count;
 573
 574         switch (total_count) {
 575         case 1:
 576                 if (tt_count)
 577                         *orig = batadv_mcast_forw_tt_node_get(bat_priv, ethhdr);
 578                 else if (ip_count)
 579                         *orig = batadv_mcast_forw_ip_node_get(bat_priv, ethhdr);
 580                 else if (unsnoop_count)
 581                         *orig = batadv_mcast_forw_unsnoop_node_get(bat_priv);
 582
 583                 if (*orig)
 584                         return BATADV_FORW_SINGLE;
 585
 586                 /* fall through */
 587         case 0:
 588                 return BATADV_FORW_NONE;
 589         default:
 590                 return BATADV_FORW_ALL;
 591         }
 592 }
 593
 594 /**
 595  * batadv_mcast_want_unsnoop_update - update unsnoop counter and list
 596  * @bat_priv: the bat priv with all the soft interface information
 597  * @orig: the orig_node which multicast state might have changed of
 598  * @mcast_flags: flags indicating the new multicast state
 599  *
 600  * If the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag of this originator,
 601  * orig, has toggled then this method updates counter and list accordingly.
 602  *
 603  * Caller needs to hold orig->mcast_handler_lock.
 604  */
 605 static void batadv_mcast_want_unsnoop_update(struct batadv_priv *bat_priv,
 606                                              struct batadv_orig_node *orig,
 607                                              u8 mcast_flags)
 608 {
 609         struct hlist_node *node = &orig->mcast_want_all_unsnoopables_node;
 610         struct hlist_head *head = &bat_priv->mcast.want_all_unsnoopables_list;
 611
 612         lockdep_assert_held(&orig->mcast_handler_lock);
 613
 614         /* switched from flag unset to set */
 615         if (mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
 616             !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES)) {
 617                 atomic_inc(&bat_priv->mcast.num_want_all_unsnoopables);
 618
 619                 spin_lock_bh(&bat_priv->mcast.want_lists_lock);
 620                 /* flag checks above + mcast_handler_lock prevents this */
 621                 WARN_ON(!hlist_unhashed(node));
 622
 623                 hlist_add_head_rcu(node, head);
 624                 spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
 625         /* switched from flag set to unset */
 626         } else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) &&
 627                    orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) {
 628                 atomic_dec(&bat_priv->mcast.num_want_all_unsnoopables);
 629
 630                 spin_lock_bh(&bat_priv->mcast.want_lists_lock);
 631                 /* flag checks above + mcast_handler_lock prevents this */
 632                 WARN_ON(hlist_unhashed(node));
 633
 634                 hlist_del_init_rcu(node);
 635                 spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
 636         }
 637 }
 638
 639 /**
 640  * batadv_mcast_want_ipv4_update - update want-all-ipv4 counter and list
 641  * @bat_priv: the bat priv with all the soft interface information
 642  * @orig: the orig_node which multicast state might have changed of
 643  * @mcast_flags: flags indicating the new multicast state
 644  *
 645  * If the BATADV_MCAST_WANT_ALL_IPV4 flag of this originator, orig, has
 646  * toggled then this method updates counter and list accordingly.
 647  *
 648  * Caller needs to hold orig->mcast_handler_lock.
 649  */
 650 static void batadv_mcast_want_ipv4_update(struct batadv_priv *bat_priv,
 651                                           struct batadv_orig_node *orig,
 652                                           u8 mcast_flags)
 653 {
 654         struct hlist_node *node = &orig->mcast_want_all_ipv4_node;
 655         struct hlist_head *head = &bat_priv->mcast.want_all_ipv4_list;
 656
 657         lockdep_assert_held(&orig->mcast_handler_lock);
 658
 659         /* switched from flag unset to set */
 660         if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV4 &&
 661             !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4)) {
 662                 atomic_inc(&bat_priv->mcast.num_want_all_ipv4);
 663
 664                 spin_lock_bh(&bat_priv->mcast.want_lists_lock);
 665                 /* flag checks above + mcast_handler_lock prevents this */
 666                 WARN_ON(!hlist_unhashed(node));
 667
 668                 hlist_add_head_rcu(node, head);
 669                 spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
 670         /* switched from flag set to unset */
 671         } else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) &&
 672                    orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) {
 673                 atomic_dec(&bat_priv->mcast.num_want_all_ipv4);
 674
 675                 spin_lock_bh(&bat_priv->mcast.want_lists_lock);
 676                 /* flag checks above + mcast_handler_lock prevents this */
 677                 WARN_ON(hlist_unhashed(node));
 678
 679                 hlist_del_init_rcu(node);
 680                 spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
 681         }
 682 }
 683
 684 /**
 685  * batadv_mcast_want_ipv6_update - update want-all-ipv6 counter and list
 686  * @bat_priv: the bat priv with all the soft interface information
 687  * @orig: the orig_node which multicast state might have changed of
 688  * @mcast_flags: flags indicating the new multicast state
 689  *
 690  * If the BATADV_MCAST_WANT_ALL_IPV6 flag of this originator, orig, has
 691  * toggled then this method updates counter and list accordingly.
 692  *
 693  * Caller needs to hold orig->mcast_handler_lock.
 694  */
 695 static void batadv_mcast_want_ipv6_update(struct batadv_priv *bat_priv,
 696                                           struct batadv_orig_node *orig,
 697                                           u8 mcast_flags)
 698 {
 699         struct hlist_node *node = &orig->mcast_want_all_ipv6_node;
 700         struct hlist_head *head = &bat_priv->mcast.want_all_ipv6_list;
 701
 702         lockdep_assert_held(&orig->mcast_handler_lock);
 703
 704         /* switched from flag unset to set */
 705         if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV6 &&
 706             !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6)) {
 707                 atomic_inc(&bat_priv->mcast.num_want_all_ipv6);
 708
 709                 spin_lock_bh(&bat_priv->mcast.want_lists_lock);
 710                 /* flag checks above + mcast_handler_lock prevents this */
 711                 WARN_ON(!hlist_unhashed(node));
 712
 713                 hlist_add_head_rcu(node, head);
 714                 spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
 715         /* switched from flag set to unset */
 716         } else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) &&
 717                    orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) {
 718                 atomic_dec(&bat_priv->mcast.num_want_all_ipv6);
 719
 720                 spin_lock_bh(&bat_priv->mcast.want_lists_lock);
 721                 /* flag checks above + mcast_handler_lock prevents this */
 722                 WARN_ON(hlist_unhashed(node));
 723
 724                 hlist_del_init_rcu(node);
 725                 spin_unlock_bh(&bat_priv->mcast.want_lists_lock);
 726         }
 727 }
 728
 729 /**
 730  * batadv_mcast_tvlv_ogm_handler_v1 - process incoming multicast tvlv container
 731  * @bat_priv: the bat priv with all the soft interface information
 732  * @orig: the orig_node of the ogm
 733  * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
 734  * @tvlv_value: tvlv buffer containing the multicast data
 735  * @tvlv_value_len: tvlv buffer length
 736  */
 737 static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
 738                                              struct batadv_orig_node *orig,
 739                                              u8 flags,
 740                                              void *tvlv_value,
 741                                              u16 tvlv_value_len)
 742 {
 743         bool orig_mcast_enabled = !(flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 744         u8 mcast_flags = BATADV_NO_FLAGS;
 745         bool orig_initialized;
 746
 747         if (orig_mcast_enabled && tvlv_value &&
 748             (tvlv_value_len >= sizeof(mcast_flags)))
 749                 mcast_flags = *(u8 *)tvlv_value;
 750
 751         spin_lock_bh(&orig->mcast_handler_lock);
 752         orig_initialized = test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
 753                                     &orig->capa_initialized);
 754
 755         /* If mcast support is turned on decrease the disabled mcast node
 756          * counter only if we had increased it for this node before. If this
 757          * is a completely new orig_node no need to decrease the counter.
 758          */
 759         if (orig_mcast_enabled &&
 760             !test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
 761                 if (orig_initialized)
 762                         atomic_dec(&bat_priv->mcast.num_disabled);
 763                 set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
 764         /* If mcast support is being switched off or if this is an initial
 765          * OGM without mcast support then increase the disabled mcast
 766          * node counter.
 767          */
 768         } else if (!orig_mcast_enabled &&
 769                    (test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) ||
 770                     !orig_initialized)) {
 771                 atomic_inc(&bat_priv->mcast.num_disabled);
 772                 clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
 773         }
 774
 775         set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized);
 776
 777         batadv_mcast_want_unsnoop_update(bat_priv, orig, mcast_flags);
 778         batadv_mcast_want_ipv4_update(bat_priv, orig, mcast_flags);
 779         batadv_mcast_want_ipv6_update(bat_priv, orig, mcast_flags);
 780
 781         orig->mcast_flags = mcast_flags;
 782         spin_unlock_bh(&orig->mcast_handler_lock);
 783 }
 784
 785 /**
 786  * batadv_mcast_init - initialize the multicast optimizations structures
 787  * @bat_priv: the bat priv with all the soft interface information
 788  */
 789 void batadv_mcast_init(struct batadv_priv *bat_priv)
 790 {
 791         batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler_v1,
 792                                      NULL, BATADV_TVLV_MCAST, 1,
 793                                      BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
 794 }
 795
 796 /**
 797  * batadv_mcast_free - free the multicast optimizations structures
 798  * @bat_priv: the bat priv with all the soft interface information
 799  */
 800 void batadv_mcast_free(struct batadv_priv *bat_priv)
 801 {
 802         batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 1);
 803         batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 1);
 804
 805         spin_lock_bh(&bat_priv->tt.commit_lock);
 806         batadv_mcast_mla_tt_retract(bat_priv, NULL);
 807         spin_unlock_bh(&bat_priv->tt.commit_lock);
 808 }
 809
 810 /**
 811  * batadv_mcast_purge_orig - reset originator global mcast state modifications
 812  * @orig: the originator which is going to get purged
 813  */
 814 void batadv_mcast_purge_orig(struct batadv_orig_node *orig)
 815 {
 816         struct batadv_priv *bat_priv = orig->bat_priv;
 817
 818         spin_lock_bh(&orig->mcast_handler_lock);
 819
 820         if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) &&
 821             test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized))
 822                 atomic_dec(&bat_priv->mcast.num_disabled);
 823
 824         batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS);
 825         batadv_mcast_want_ipv4_update(bat_priv, orig, BATADV_NO_FLAGS);
 826         batadv_mcast_want_ipv6_update(bat_priv, orig, BATADV_NO_FLAGS);
 827
 828         spin_unlock_bh(&orig->mcast_handler_lock);
 829 }