net/batman-adv/bridge_loop_avoidance.c

   1 /* Copyright (C) 2011-2013 B.A.T.M.A.N. contributors:
   2  *
   3  * Simon Wunderlich
   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, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA
  18  */
  19
  20 #include "main.h"
  21 #include "hash.h"
  22 #include "hard-interface.h"
  23 #include "originator.h"
  24 #include "bridge_loop_avoidance.h"
  25 #include "translation-table.h"
  26 #include "send.h"
  27
  28 #include <linux/etherdevice.h>
  29 #include <linux/crc16.h>
  30 #include <linux/if_arp.h>
  31 #include <net/arp.h>
  32 #include <linux/if_vlan.h>
  33
  34 static const uint8_t batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
  35
  36 static void batadv_bla_periodic_work(struct work_struct *work);
  37 static void
  38 batadv_bla_send_announce(struct batadv_priv *bat_priv,
  39                          struct batadv_bla_backbone_gw *backbone_gw);
  40
  41 /* return the index of the claim */
  42 static inline uint32_t batadv_choose_claim(const void *data, uint32_t size)
  43 {
  44         struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
  45         uint32_t hash = 0;
  46
  47         hash = batadv_hash_bytes(hash, &claim->addr, sizeof(claim->addr));
  48         hash = batadv_hash_bytes(hash, &claim->vid, sizeof(claim->vid));
  49
  50         hash += (hash << 3);
  51         hash ^= (hash >> 11);
  52         hash += (hash << 15);
  53
  54         return hash % size;
  55 }
  56
  57 /* return the index of the backbone gateway */
  58 static inline uint32_t batadv_choose_backbone_gw(const void *data,
  59                                                  uint32_t size)
  60 {
  61         const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
  62         uint32_t hash = 0;
  63
  64         hash = batadv_hash_bytes(hash, &claim->addr, sizeof(claim->addr));
  65         hash = batadv_hash_bytes(hash, &claim->vid, sizeof(claim->vid));
  66
  67         hash += (hash << 3);
  68         hash ^= (hash >> 11);
  69         hash += (hash << 15);
  70
  71         return hash % size;
  72 }
  73
  74
  75 /* compares address and vid of two backbone gws */
  76 static int batadv_compare_backbone_gw(const struct hlist_node *node,
  77                                       const void *data2)
  78 {
  79         const void *data1 = container_of(node, struct batadv_bla_backbone_gw,
  80                                          hash_entry);
  81         const struct batadv_bla_backbone_gw *gw1 = data1, *gw2 = data2;
  82
  83         if (!batadv_compare_eth(gw1->orig, gw2->orig))
  84                 return 0;
  85
  86         if (gw1->vid != gw2->vid)
  87                 return 0;
  88
  89         return 1;
  90 }
  91
  92 /* compares address and vid of two claims */
  93 static int batadv_compare_claim(const struct hlist_node *node,
  94                                 const void *data2)
  95 {
  96         const void *data1 = container_of(node, struct batadv_bla_claim,
  97                                          hash_entry);
  98         const struct batadv_bla_claim *cl1 = data1, *cl2 = data2;
  99
 100         if (!batadv_compare_eth(cl1->addr, cl2->addr))
 101                 return 0;
 102
 103         if (cl1->vid != cl2->vid)
 104                 return 0;
 105
 106         return 1;
 107 }
 108
 109 /* free a backbone gw */
 110 static void
 111 batadv_backbone_gw_free_ref(struct batadv_bla_backbone_gw *backbone_gw)
 112 {
 113         if (atomic_dec_and_test(&backbone_gw->refcount))
 114                 kfree_rcu(backbone_gw, rcu);
 115 }
 116
 117 /* finally deinitialize the claim */
 118 static void batadv_claim_free_rcu(struct rcu_head *rcu)
 119 {
 120         struct batadv_bla_claim *claim;
 121
 122         claim = container_of(rcu, struct batadv_bla_claim, rcu);
 123
 124         batadv_backbone_gw_free_ref(claim->backbone_gw);
 125         kfree(claim);
 126 }
 127
 128 /* free a claim, call claim_free_rcu if its the last reference */
 129 static void batadv_claim_free_ref(struct batadv_bla_claim *claim)
 130 {
 131         if (atomic_dec_and_test(&claim->refcount))
 132                 call_rcu(&claim->rcu, batadv_claim_free_rcu);
 133 }
 134
 135 /* @bat_priv: the bat priv with all the soft interface information
 136  * @data: search data (may be local/static data)
 137  *
 138  * looks for a claim in the hash, and returns it if found
 139  * or NULL otherwise.
 140  */
 141 static struct batadv_bla_claim
 142 *batadv_claim_hash_find(struct batadv_priv *bat_priv,
 143                         struct batadv_bla_claim *data)
 144 {
 145         struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
 146         struct hlist_head *head;
 147         struct batadv_bla_claim *claim;
 148         struct batadv_bla_claim *claim_tmp = NULL;
 149         int index;
 150
 151         if (!hash)
 152                 return NULL;
 153
 154         index = batadv_choose_claim(data, hash->size);
 155         head = &hash->table[index];
 156
 157         rcu_read_lock();
 158         hlist_for_each_entry_rcu(claim, head, hash_entry) {
 159                 if (!batadv_compare_claim(&claim->hash_entry, data))
 160                         continue;
 161
 162                 if (!atomic_inc_not_zero(&claim->refcount))
 163                         continue;
 164
 165                 claim_tmp = claim;
 166                 break;
 167         }
 168         rcu_read_unlock();
 169
 170         return claim_tmp;
 171 }
 172
 173 /**
 174  * batadv_backbone_hash_find - looks for a claim in the hash
 175  * @bat_priv: the bat priv with all the soft interface information
 176  * @addr: the address of the originator
 177  * @vid: the VLAN ID
 178  *
 179  * Returns claim if found or NULL otherwise.
 180  */
 181 static struct batadv_bla_backbone_gw *
 182 batadv_backbone_hash_find(struct batadv_priv *bat_priv,
 183                           uint8_t *addr, unsigned short vid)
 184 {
 185         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
 186         struct hlist_head *head;
 187         struct batadv_bla_backbone_gw search_entry, *backbone_gw;
 188         struct batadv_bla_backbone_gw *backbone_gw_tmp = NULL;
 189         int index;
 190
 191         if (!hash)
 192                 return NULL;
 193
 194         memcpy(search_entry.orig, addr, ETH_ALEN);
 195         search_entry.vid = vid;
 196
 197         index = batadv_choose_backbone_gw(&search_entry, hash->size);
 198         head = &hash->table[index];
 199
 200         rcu_read_lock();
 201         hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
 202                 if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry,
 203                                                 &search_entry))
 204                         continue;
 205
 206                 if (!atomic_inc_not_zero(&backbone_gw->refcount))
 207                         continue;
 208
 209                 backbone_gw_tmp = backbone_gw;
 210                 break;
 211         }
 212         rcu_read_unlock();
 213
 214         return backbone_gw_tmp;
 215 }
 216
 217 /* delete all claims for a backbone */
 218 static void
 219 batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw)
 220 {
 221         struct batadv_hashtable *hash;
 222         struct hlist_node *node_tmp;
 223         struct hlist_head *head;
 224         struct batadv_bla_claim *claim;
 225         int i;
 226         spinlock_t *list_lock;  /* protects write access to the hash lists */
 227
 228         hash = backbone_gw->bat_priv->bla.claim_hash;
 229         if (!hash)
 230                 return;
 231
 232         for (i = 0; i < hash->size; i++) {
 233                 head = &hash->table[i];
 234                 list_lock = &hash->list_locks[i];
 235
 236                 spin_lock_bh(list_lock);
 237                 hlist_for_each_entry_safe(claim, node_tmp,
 238                                           head, hash_entry) {
 239                         if (claim->backbone_gw != backbone_gw)
 240                                 continue;
 241
 242                         batadv_claim_free_ref(claim);
 243                         hlist_del_rcu(&claim->hash_entry);
 244                 }
 245                 spin_unlock_bh(list_lock);
 246         }
 247
 248         /* all claims gone, intialize CRC */
 249         backbone_gw->crc = BATADV_BLA_CRC_INIT;
 250 }
 251
 252 /**
 253  * batadv_bla_send_claim - sends a claim frame according to the provided info
 254  * @bat_priv: the bat priv with all the soft interface information
 255  * @orig: the mac address to be announced within the claim
 256  * @vid: the VLAN ID
 257  * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...)
 258  */
 259 static void batadv_bla_send_claim(struct batadv_priv *bat_priv, uint8_t *mac,
 260                                   unsigned short vid, int claimtype)
 261 {
 262         struct sk_buff *skb;
 263         struct ethhdr *ethhdr;
 264         struct batadv_hard_iface *primary_if;
 265         struct net_device *soft_iface;
 266         uint8_t *hw_src;
 267         struct batadv_bla_claim_dst local_claim_dest;
 268         __be32 zeroip = 0;
 269
 270         primary_if = batadv_primary_if_get_selected(bat_priv);
 271         if (!primary_if)
 272                 return;
 273
 274         memcpy(&local_claim_dest, &bat_priv->bla.claim_dest,
 275                sizeof(local_claim_dest));
 276         local_claim_dest.type = claimtype;
 277
 278         soft_iface = primary_if->soft_iface;
 279
 280         skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
 281                          /* IP DST: 0.0.0.0 */
 282                          zeroip,
 283                          primary_if->soft_iface,
 284                          /* IP SRC: 0.0.0.0 */
 285                          zeroip,
 286                          /* Ethernet DST: Broadcast */
 287                          NULL,
 288                          /* Ethernet SRC/HW SRC:  originator mac */
 289                          primary_if->net_dev->dev_addr,
 290                          /* HW DST: FF:43:05:XX:YY:YY
 291                           * with XX   = claim type
 292                           * and YY:YY = group id
 293                           */
 294                          (uint8_t *)&local_claim_dest);
 295
 296         if (!skb)
 297                 goto out;
 298
 299         ethhdr = (struct ethhdr *)skb->data;
 300         hw_src = (uint8_t *)ethhdr + ETH_HLEN + sizeof(struct arphdr);
 301
 302         /* now we pretend that the client would have sent this ... */
 303         switch (claimtype) {
 304         case BATADV_CLAIM_TYPE_CLAIM:
 305                 /* normal claim frame
 306                  * set Ethernet SRC to the clients mac
 307                  */
 308                 memcpy(ethhdr->h_source, mac, ETH_ALEN);
 309                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 310                            "bla_send_claim(): CLAIM %pM on vid %d\n", mac,
 311                            BATADV_PRINT_VID(vid));
 312                 break;
 313         case BATADV_CLAIM_TYPE_UNCLAIM:
 314                 /* unclaim frame
 315                  * set HW SRC to the clients mac
 316                  */
 317                 memcpy(hw_src, mac, ETH_ALEN);
 318                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 319                            "bla_send_claim(): UNCLAIM %pM on vid %d\n", mac,
 320                            BATADV_PRINT_VID(vid));
 321                 break;
 322         case BATADV_CLAIM_TYPE_ANNOUNCE:
 323                 /* announcement frame
 324                  * set HW SRC to the special mac containg the crc
 325                  */
 326                 memcpy(hw_src, mac, ETH_ALEN);
 327                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 328                            "bla_send_claim(): ANNOUNCE of %pM on vid %d\n",
 329                            ethhdr->h_source, BATADV_PRINT_VID(vid));
 330                 break;
 331         case BATADV_CLAIM_TYPE_REQUEST:
 332                 /* request frame
 333                  * set HW SRC and header destination to the receiving backbone
 334                  * gws mac
 335                  */
 336                 memcpy(hw_src, mac, ETH_ALEN);
 337                 memcpy(ethhdr->h_dest, mac, ETH_ALEN);
 338                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 339                            "bla_send_claim(): REQUEST of %pM to %pM on vid %d\n",
 340                            ethhdr->h_source, ethhdr->h_dest,
 341                            BATADV_PRINT_VID(vid));
 342                 break;
 343         }
 344
 345         if (vid & BATADV_VLAN_HAS_TAG)
 346                 skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
 347                                       vid & VLAN_VID_MASK);
 348
 349         skb_reset_mac_header(skb);
 350         skb->protocol = eth_type_trans(skb, soft_iface);
 351         batadv_inc_counter(bat_priv, BATADV_CNT_RX);
 352         batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
 353                            skb->len + ETH_HLEN);
 354         soft_iface->last_rx = jiffies;
 355
 356         netif_rx(skb);
 357 out:
 358         if (primary_if)
 359                 batadv_hardif_free_ref(primary_if);
 360 }
 361
 362 /**
 363  * batadv_bla_get_backbone_gw
 364  * @bat_priv: the bat priv with all the soft interface information
 365  * @orig: the mac address of the originator
 366  * @vid: the VLAN ID
 367  *
 368  * searches for the backbone gw or creates a new one if it could not
 369  * be found.
 370  */
 371 static struct batadv_bla_backbone_gw *
 372 batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig,
 373                            unsigned short vid, bool own_backbone)
 374 {
 375         struct batadv_bla_backbone_gw *entry;
 376         struct batadv_orig_node *orig_node;
 377         int hash_added;
 378
 379         entry = batadv_backbone_hash_find(bat_priv, orig, vid);
 380
 381         if (entry)
 382                 return entry;
 383
 384         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 385                    "bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n",
 386                    orig, BATADV_PRINT_VID(vid));
 387
 388         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 389         if (!entry)
 390                 return NULL;
 391
 392         entry->vid = vid;
 393         entry->lasttime = jiffies;
 394         entry->crc = BATADV_BLA_CRC_INIT;
 395         entry->bat_priv = bat_priv;
 396         atomic_set(&entry->request_sent, 0);
 397         atomic_set(&entry->wait_periods, 0);
 398         memcpy(entry->orig, orig, ETH_ALEN);
 399
 400         /* one for the hash, one for returning */
 401         atomic_set(&entry->refcount, 2);
 402
 403         hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
 404                                      batadv_compare_backbone_gw,
 405                                      batadv_choose_backbone_gw, entry,
 406                                      &entry->hash_entry);
 407
 408         if (unlikely(hash_added != 0)) {
 409                 /* hash failed, free the structure */
 410                 kfree(entry);
 411                 return NULL;
 412         }
 413
 414         /* this is a gateway now, remove any tt entries */
 415         orig_node = batadv_orig_hash_find(bat_priv, orig);
 416         if (orig_node) {
 417                 batadv_tt_global_del_orig(bat_priv, orig_node,
 418                                           "became a backbone gateway");
 419                 batadv_orig_node_free_ref(orig_node);
 420         }
 421
 422         if (own_backbone) {
 423                 batadv_bla_send_announce(bat_priv, entry);
 424
 425                 /* this will be decreased in the worker thread */
 426                 atomic_inc(&entry->request_sent);
 427                 atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
 428                 atomic_inc(&bat_priv->bla.num_requests);
 429         }
 430
 431         return entry;
 432 }
 433
 434 /* update or add the own backbone gw to make sure we announce
 435  * where we receive other backbone gws
 436  */
 437 static void
 438 batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv,
 439                                   struct batadv_hard_iface *primary_if,
 440                                   unsigned short vid)
 441 {
 442         struct batadv_bla_backbone_gw *backbone_gw;
 443
 444         backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
 445                                                  primary_if->net_dev->dev_addr,
 446                                                  vid, true);
 447         if (unlikely(!backbone_gw))
 448                 return;
 449
 450         backbone_gw->lasttime = jiffies;
 451         batadv_backbone_gw_free_ref(backbone_gw);
 452 }
 453
 454 /* @bat_priv: the bat priv with all the soft interface information
 455  * @vid: the vid where the request came on
 456  *
 457  * Repeat all of our own claims, and finally send an ANNOUNCE frame
 458  * to allow the requester another check if the CRC is correct now.
 459  */
 460 static void batadv_bla_answer_request(struct batadv_priv *bat_priv,
 461                                       struct batadv_hard_iface *primary_if,
 462                                       unsigned short vid)
 463 {
 464         struct hlist_head *head;
 465         struct batadv_hashtable *hash;
 466         struct batadv_bla_claim *claim;
 467         struct batadv_bla_backbone_gw *backbone_gw;
 468         int i;
 469
 470         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 471                    "bla_answer_request(): received a claim request, send all of our own claims again\n");
 472
 473         backbone_gw = batadv_backbone_hash_find(bat_priv,
 474                                                 primary_if->net_dev->dev_addr,
 475                                                 vid);
 476         if (!backbone_gw)
 477                 return;
 478
 479         hash = bat_priv->bla.claim_hash;
 480         for (i = 0; i < hash->size; i++) {
 481                 head = &hash->table[i];
 482
 483                 rcu_read_lock();
 484                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
 485                         /* only own claims are interesting */
 486                         if (claim->backbone_gw != backbone_gw)
 487                                 continue;
 488
 489                         batadv_bla_send_claim(bat_priv, claim->addr, claim->vid,
 490                                               BATADV_CLAIM_TYPE_CLAIM);
 491                 }
 492                 rcu_read_unlock();
 493         }
 494
 495         /* finally, send an announcement frame */
 496         batadv_bla_send_announce(bat_priv, backbone_gw);
 497         batadv_backbone_gw_free_ref(backbone_gw);
 498 }
 499
 500 /* @backbone_gw: the backbone gateway from whom we are out of sync
 501  *
 502  * When the crc is wrong, ask the backbone gateway for a full table update.
 503  * After the request, it will repeat all of his own claims and finally
 504  * send an announcement claim with which we can check again.
 505  */
 506 static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw)
 507 {
 508         /* first, remove all old entries */
 509         batadv_bla_del_backbone_claims(backbone_gw);
 510
 511         batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
 512                    "Sending REQUEST to %pM\n", backbone_gw->orig);
 513
 514         /* send request */
 515         batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig,
 516                               backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST);
 517
 518         /* no local broadcasts should be sent or received, for now. */
 519         if (!atomic_read(&backbone_gw->request_sent)) {
 520                 atomic_inc(&backbone_gw->bat_priv->bla.num_requests);
 521                 atomic_set(&backbone_gw->request_sent, 1);
 522         }
 523 }
 524
 525 /* @bat_priv: the bat priv with all the soft interface information
 526  * @backbone_gw: our backbone gateway which should be announced
 527  *
 528  * This function sends an announcement. It is called from multiple
 529  * places.
 530  */
 531 static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
 532                                      struct batadv_bla_backbone_gw *backbone_gw)
 533 {
 534         uint8_t mac[ETH_ALEN];
 535         __be16 crc;
 536
 537         memcpy(mac, batadv_announce_mac, 4);
 538         crc = htons(backbone_gw->crc);
 539         memcpy(&mac[4], &crc, 2);
 540
 541         batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid,
 542                               BATADV_CLAIM_TYPE_ANNOUNCE);
 543 }
 544
 545 /**
 546  * batadv_bla_add_claim - Adds a claim in the claim hash
 547  * @bat_priv: the bat priv with all the soft interface information
 548  * @mac: the mac address of the claim
 549  * @vid: the VLAN ID of the frame
 550  * @backbone_gw: the backbone gateway which claims it
 551  */
 552 static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 553                                  const uint8_t *mac, const unsigned short vid,
 554                                  struct batadv_bla_backbone_gw *backbone_gw)
 555 {
 556         struct batadv_bla_claim *claim;
 557         struct batadv_bla_claim search_claim;
 558         int hash_added;
 559
 560         memcpy(search_claim.addr, mac, ETH_ALEN);
 561         search_claim.vid = vid;
 562         claim = batadv_claim_hash_find(bat_priv, &search_claim);
 563
 564         /* create a new claim entry if it does not exist yet. */
 565         if (!claim) {
 566                 claim = kzalloc(sizeof(*claim), GFP_ATOMIC);
 567                 if (!claim)
 568                         return;
 569
 570                 memcpy(claim->addr, mac, ETH_ALEN);
 571                 claim->vid = vid;
 572                 claim->lasttime = jiffies;
 573                 claim->backbone_gw = backbone_gw;
 574
 575                 atomic_set(&claim->refcount, 2);
 576                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 577                            "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n",
 578                            mac, BATADV_PRINT_VID(vid));
 579                 hash_added = batadv_hash_add(bat_priv->bla.claim_hash,
 580                                              batadv_compare_claim,
 581                                              batadv_choose_claim, claim,
 582                                              &claim->hash_entry);
 583
 584                 if (unlikely(hash_added != 0)) {
 585                         /* only local changes happened. */
 586                         kfree(claim);
 587                         return;
 588                 }
 589         } else {
 590                 claim->lasttime = jiffies;
 591                 if (claim->backbone_gw == backbone_gw)
 592                         /* no need to register a new backbone */
 593                         goto claim_free_ref;
 594
 595                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 596                            "bla_add_claim(): changing ownership for %pM, vid %d\n",
 597                            mac, BATADV_PRINT_VID(vid));
 598
 599                 claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 600                 batadv_backbone_gw_free_ref(claim->backbone_gw);
 601         }
 602         /* set (new) backbone gw */
 603         atomic_inc(&backbone_gw->refcount);
 604         claim->backbone_gw = backbone_gw;
 605
 606         backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 607         backbone_gw->lasttime = jiffies;
 608
 609 claim_free_ref:
 610         batadv_claim_free_ref(claim);
 611 }
 612
 613 /* Delete a claim from the claim hash which has the
 614  * given mac address and vid.
 615  */
 616 static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
 617                                  const uint8_t *mac, const unsigned short vid)
 618 {
 619         struct batadv_bla_claim search_claim, *claim;
 620
 621         memcpy(search_claim.addr, mac, ETH_ALEN);
 622         search_claim.vid = vid;
 623         claim = batadv_claim_hash_find(bat_priv, &search_claim);
 624         if (!claim)
 625                 return;
 626
 627         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n",
 628                    mac, BATADV_PRINT_VID(vid));
 629
 630         batadv_hash_remove(bat_priv->bla.claim_hash, batadv_compare_claim,
 631                            batadv_choose_claim, claim);
 632         batadv_claim_free_ref(claim); /* reference from the hash is gone */
 633
 634         claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 635
 636         /* don't need the reference from hash_find() anymore */
 637         batadv_claim_free_ref(claim);
 638 }
 639
 640 /* check for ANNOUNCE frame, return 1 if handled */
 641 static int batadv_handle_announce(struct batadv_priv *bat_priv,
 642                                   uint8_t *an_addr, uint8_t *backbone_addr,
 643                                   unsigned short vid)
 644 {
 645         struct batadv_bla_backbone_gw *backbone_gw;
 646         uint16_t crc;
 647
 648         if (memcmp(an_addr, batadv_announce_mac, 4) != 0)
 649                 return 0;
 650
 651         backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
 652                                                  false);
 653
 654         if (unlikely(!backbone_gw))
 655                 return 1;
 656
 657
 658         /* handle as ANNOUNCE frame */
 659         backbone_gw->lasttime = jiffies;
 660         crc = ntohs(*((__be16 *)(&an_addr[4])));
 661
 662         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 663                    "handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n",
 664                    BATADV_PRINT_VID(vid), backbone_gw->orig, crc);
 665
 666         if (backbone_gw->crc != crc) {
 667                 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
 668                            "handle_announce(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n",
 669                            backbone_gw->orig,
 670                            BATADV_PRINT_VID(backbone_gw->vid),
 671                            backbone_gw->crc, crc);
 672
 673                 batadv_bla_send_request(backbone_gw);
 674         } else {
 675                 /* if we have sent a request and the crc was OK,
 676                  * we can allow traffic again.
 677                  */
 678                 if (atomic_read(&backbone_gw->request_sent)) {
 679                         atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
 680                         atomic_set(&backbone_gw->request_sent, 0);
 681                 }
 682         }
 683
 684         batadv_backbone_gw_free_ref(backbone_gw);
 685         return 1;
 686 }
 687
 688 /* check for REQUEST frame, return 1 if handled */
 689 static int batadv_handle_request(struct batadv_priv *bat_priv,
 690                                  struct batadv_hard_iface *primary_if,
 691                                  uint8_t *backbone_addr,
 692                                  struct ethhdr *ethhdr, unsigned short vid)
 693 {
 694         /* check for REQUEST frame */
 695         if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest))
 696                 return 0;
 697
 698         /* sanity check, this should not happen on a normal switch,
 699          * we ignore it in this case.
 700          */
 701         if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr))
 702                 return 1;
 703
 704         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 705                    "handle_request(): REQUEST vid %d (sent by %pM)...\n",
 706                    BATADV_PRINT_VID(vid), ethhdr->h_source);
 707
 708         batadv_bla_answer_request(bat_priv, primary_if, vid);
 709         return 1;
 710 }
 711
 712 /* check for UNCLAIM frame, return 1 if handled */
 713 static int batadv_handle_unclaim(struct batadv_priv *bat_priv,
 714                                  struct batadv_hard_iface *primary_if,
 715                                  uint8_t *backbone_addr,
 716                                  uint8_t *claim_addr, unsigned short vid)
 717 {
 718         struct batadv_bla_backbone_gw *backbone_gw;
 719
 720         /* unclaim in any case if it is our own */
 721         if (primary_if && batadv_compare_eth(backbone_addr,
 722                                              primary_if->net_dev->dev_addr))
 723                 batadv_bla_send_claim(bat_priv, claim_addr, vid,
 724                                       BATADV_CLAIM_TYPE_UNCLAIM);
 725
 726         backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid);
 727
 728         if (!backbone_gw)
 729                 return 1;
 730
 731         /* this must be an UNCLAIM frame */
 732         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 733                    "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n",
 734                    claim_addr, BATADV_PRINT_VID(vid), backbone_gw->orig);
 735
 736         batadv_bla_del_claim(bat_priv, claim_addr, vid);
 737         batadv_backbone_gw_free_ref(backbone_gw);
 738         return 1;
 739 }
 740
 741 /* check for CLAIM frame, return 1 if handled */
 742 static int batadv_handle_claim(struct batadv_priv *bat_priv,
 743                                struct batadv_hard_iface *primary_if,
 744                                uint8_t *backbone_addr, uint8_t *claim_addr,
 745                                unsigned short vid)
 746 {
 747         struct batadv_bla_backbone_gw *backbone_gw;
 748
 749         /* register the gateway if not yet available, and add the claim. */
 750
 751         backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
 752                                                  false);
 753
 754         if (unlikely(!backbone_gw))
 755                 return 1;
 756
 757         /* this must be a CLAIM frame */
 758         batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw);
 759         if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
 760                 batadv_bla_send_claim(bat_priv, claim_addr, vid,
 761                                       BATADV_CLAIM_TYPE_CLAIM);
 762
 763         /* TODO: we could call something like tt_local_del() here. */
 764
 765         batadv_backbone_gw_free_ref(backbone_gw);
 766         return 1;
 767 }
 768
 769 /**
 770  * batadv_check_claim_group
 771  * @bat_priv: the bat priv with all the soft interface information
 772  * @hw_src: the Hardware source in the ARP Header
 773  * @hw_dst: the Hardware destination in the ARP Header
 774  * @ethhdr: pointer to the Ethernet header of the claim frame
 775  *
 776  * checks if it is a claim packet and if its on the same group.
 777  * This function also applies the group ID of the sender
 778  * if it is in the same mesh.
 779  *
 780  * returns:
 781  *      2  - if it is a claim packet and on the same group
 782  *      1  - if is a claim packet from another group
 783  *      0  - if it is not a claim packet
 784  */
 785 static int batadv_check_claim_group(struct batadv_priv *bat_priv,
 786                                     struct batadv_hard_iface *primary_if,
 787                                     uint8_t *hw_src, uint8_t *hw_dst,
 788                                     struct ethhdr *ethhdr)
 789 {
 790         uint8_t *backbone_addr;
 791         struct batadv_orig_node *orig_node;
 792         struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
 793
 794         bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
 795         bla_dst_own = &bat_priv->bla.claim_dest;
 796
 797         /* check if it is a claim packet in general */
 798         if (memcmp(bla_dst->magic, bla_dst_own->magic,
 799                    sizeof(bla_dst->magic)) != 0)
 800                 return 0;
 801
 802         /* if announcement packet, use the source,
 803          * otherwise assume it is in the hw_src
 804          */
 805         switch (bla_dst->type) {
 806         case BATADV_CLAIM_TYPE_CLAIM:
 807                 backbone_addr = hw_src;
 808                 break;
 809         case BATADV_CLAIM_TYPE_REQUEST:
 810         case BATADV_CLAIM_TYPE_ANNOUNCE:
 811         case BATADV_CLAIM_TYPE_UNCLAIM:
 812                 backbone_addr = ethhdr->h_source;
 813                 break;
 814         default:
 815                 return 0;
 816         }
 817
 818         /* don't accept claim frames from ourselves */
 819         if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
 820                 return 0;
 821
 822         /* if its already the same group, it is fine. */
 823         if (bla_dst->group == bla_dst_own->group)
 824                 return 2;
 825
 826         /* lets see if this originator is in our mesh */
 827         orig_node = batadv_orig_hash_find(bat_priv, backbone_addr);
 828
 829         /* dont accept claims from gateways which are not in
 830          * the same mesh or group.
 831          */
 832         if (!orig_node)
 833                 return 1;
 834
 835         /* if our mesh friends mac is bigger, use it for ourselves. */
 836         if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) {
 837                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 838                            "taking other backbones claim group: %#.4x\n",
 839                            ntohs(bla_dst->group));
 840                 bla_dst_own->group = bla_dst->group;
 841         }
 842
 843         batadv_orig_node_free_ref(orig_node);
 844
 845         return 2;
 846 }
 847
 848
 849 /* @bat_priv: the bat priv with all the soft interface information
 850  * @skb: the frame to be checked
 851  *
 852  * Check if this is a claim frame, and process it accordingly.
 853  *
 854  * returns 1 if it was a claim frame, otherwise return 0 to
 855  * tell the callee that it can use the frame on its own.
 856  */
 857 static int batadv_bla_process_claim(struct batadv_priv *bat_priv,
 858                                     struct batadv_hard_iface *primary_if,
 859                                     struct sk_buff *skb)
 860 {
 861         struct ethhdr *ethhdr;
 862         struct vlan_ethhdr *vhdr;
 863         struct arphdr *arphdr;
 864         uint8_t *hw_src, *hw_dst;
 865         struct batadv_bla_claim_dst *bla_dst;
 866         uint16_t proto;
 867         int headlen;
 868         unsigned short vid = BATADV_NO_FLAGS;
 869         int ret;
 870
 871         ethhdr = eth_hdr(skb);
 872
 873         if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
 874                 vhdr = (struct vlan_ethhdr *)ethhdr;
 875                 vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
 876                 vid |= BATADV_VLAN_HAS_TAG;
 877                 proto = ntohs(vhdr->h_vlan_encapsulated_proto);
 878                 headlen = sizeof(*vhdr);
 879         } else {
 880                 proto = ntohs(ethhdr->h_proto);
 881                 headlen = ETH_HLEN;
 882         }
 883
 884         if (proto != ETH_P_ARP)
 885                 return 0; /* not a claim frame */
 886
 887         /* this must be a ARP frame. check if it is a claim. */
 888
 889         if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
 890                 return 0;
 891
 892         /* pskb_may_pull() may have modified the pointers, get ethhdr again */
 893         ethhdr = eth_hdr(skb);
 894         arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen);
 895
 896         /* Check whether the ARP frame carries a valid
 897          * IP information
 898          */
 899         if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
 900                 return 0;
 901         if (arphdr->ar_pro != htons(ETH_P_IP))
 902                 return 0;
 903         if (arphdr->ar_hln != ETH_ALEN)
 904                 return 0;
 905         if (arphdr->ar_pln != 4)
 906                 return 0;
 907
 908         hw_src = (uint8_t *)arphdr + sizeof(struct arphdr);
 909         hw_dst = hw_src + ETH_ALEN + 4;
 910         bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
 911
 912         /* check if it is a claim frame. */
 913         ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
 914                                        ethhdr);
 915         if (ret == 1)
 916                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 917                            "bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
 918                            ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src,
 919                            hw_dst);
 920
 921         if (ret < 2)
 922                 return ret;
 923
 924         /* become a backbone gw ourselves on this vlan if not happened yet */
 925         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
 926
 927         /* check for the different types of claim frames ... */
 928         switch (bla_dst->type) {
 929         case BATADV_CLAIM_TYPE_CLAIM:
 930                 if (batadv_handle_claim(bat_priv, primary_if, hw_src,
 931                                         ethhdr->h_source, vid))
 932                         return 1;
 933                 break;
 934         case BATADV_CLAIM_TYPE_UNCLAIM:
 935                 if (batadv_handle_unclaim(bat_priv, primary_if,
 936                                           ethhdr->h_source, hw_src, vid))
 937                         return 1;
 938                 break;
 939
 940         case BATADV_CLAIM_TYPE_ANNOUNCE:
 941                 if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
 942                                            vid))
 943                         return 1;
 944                 break;
 945         case BATADV_CLAIM_TYPE_REQUEST:
 946                 if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
 947                                           vid))
 948                         return 1;
 949                 break;
 950         }
 951
 952         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 953                    "bla_process_claim(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
 954                    ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src, hw_dst);
 955         return 1;
 956 }
 957
 958 /* Check when we last heard from other nodes, and remove them in case of
 959  * a time out, or clean all backbone gws if now is set.
 960  */
 961 static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now)
 962 {
 963         struct batadv_bla_backbone_gw *backbone_gw;
 964         struct hlist_node *node_tmp;
 965         struct hlist_head *head;
 966         struct batadv_hashtable *hash;
 967         spinlock_t *list_lock;  /* protects write access to the hash lists */
 968         int i;
 969
 970         hash = bat_priv->bla.backbone_hash;
 971         if (!hash)
 972                 return;
 973
 974         for (i = 0; i < hash->size; i++) {
 975                 head = &hash->table[i];
 976                 list_lock = &hash->list_locks[i];
 977
 978                 spin_lock_bh(list_lock);
 979                 hlist_for_each_entry_safe(backbone_gw, node_tmp,
 980                                           head, hash_entry) {
 981                         if (now)
 982                                 goto purge_now;
 983                         if (!batadv_has_timed_out(backbone_gw->lasttime,
 984                                                   BATADV_BLA_BACKBONE_TIMEOUT))
 985                                 continue;
 986
 987                         batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
 988                                    "bla_purge_backbone_gw(): backbone gw %pM timed out\n",
 989                                    backbone_gw->orig);
 990
 991 purge_now:
 992                         /* don't wait for the pending request anymore */
 993                         if (atomic_read(&backbone_gw->request_sent))
 994                                 atomic_dec(&bat_priv->bla.num_requests);
 995
 996                         batadv_bla_del_backbone_claims(backbone_gw);
 997
 998                         hlist_del_rcu(&backbone_gw->hash_entry);
 999                         batadv_backbone_gw_free_ref(backbone_gw);
1000                 }
1001                 spin_unlock_bh(list_lock);
1002         }
1003 }
1004
1005 /**
1006  * batadv_bla_purge_claims
1007  * @bat_priv: the bat priv with all the soft interface information
1008  * @primary_if: the selected primary interface, may be NULL if now is set
1009  * @now: whether the whole hash shall be wiped now
1010  *
1011  * Check when we heard last time from our own claims, and remove them in case of
1012  * a time out, or clean all claims if now is set
1013  */
1014 static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
1015                                     struct batadv_hard_iface *primary_if,
1016                                     int now)
1017 {
1018         struct batadv_bla_claim *claim;
1019         struct hlist_head *head;
1020         struct batadv_hashtable *hash;
1021         int i;
1022
1023         hash = bat_priv->bla.claim_hash;
1024         if (!hash)
1025                 return;
1026
1027         for (i = 0; i < hash->size; i++) {
1028                 head = &hash->table[i];
1029
1030                 rcu_read_lock();
1031                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
1032                         if (now)
1033                                 goto purge_now;
1034                         if (!batadv_compare_eth(claim->backbone_gw->orig,
1035                                                 primary_if->net_dev->dev_addr))
1036                                 continue;
1037                         if (!batadv_has_timed_out(claim->lasttime,
1038                                                   BATADV_BLA_CLAIM_TIMEOUT))
1039                                 continue;
1040
1041                         batadv_dbg(BATADV_DBG_BLA, bat_priv,
1042                                    "bla_purge_claims(): %pM, vid %d, time out\n",
1043                                    claim->addr, claim->vid);
1044
1045 purge_now:
1046                         batadv_handle_unclaim(bat_priv, primary_if,
1047                                               claim->backbone_gw->orig,
1048                                               claim->addr, claim->vid);
1049                 }
1050                 rcu_read_unlock();
1051         }
1052 }
1053
1054 /**
1055  * batadv_bla_update_orig_address
1056  * @bat_priv: the bat priv with all the soft interface information
1057  * @primary_if: the new selected primary_if
1058  * @oldif: the old primary interface, may be NULL
1059  *
1060  * Update the backbone gateways when the own orig address changes.
1061  */
1062 void batadv_bla_update_orig_address(struct batadv_priv *bat_priv,
1063                                     struct batadv_hard_iface *primary_if,
1064                                     struct batadv_hard_iface *oldif)
1065 {
1066         struct batadv_bla_backbone_gw *backbone_gw;
1067         struct hlist_head *head;
1068         struct batadv_hashtable *hash;
1069         __be16 group;
1070         int i;
1071
1072         /* reset bridge loop avoidance group id */
1073         group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN));
1074         bat_priv->bla.claim_dest.group = group;
1075
1076         /* purge everything when bridge loop avoidance is turned off */
1077         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1078                 oldif = NULL;
1079
1080         if (!oldif) {
1081                 batadv_bla_purge_claims(bat_priv, NULL, 1);
1082                 batadv_bla_purge_backbone_gw(bat_priv, 1);
1083                 return;
1084         }
1085
1086         hash = bat_priv->bla.backbone_hash;
1087         if (!hash)
1088                 return;
1089
1090         for (i = 0; i < hash->size; i++) {
1091                 head = &hash->table[i];
1092
1093                 rcu_read_lock();
1094                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1095                         /* own orig still holds the old value. */
1096                         if (!batadv_compare_eth(backbone_gw->orig,
1097                                                 oldif->net_dev->dev_addr))
1098                                 continue;
1099
1100                         memcpy(backbone_gw->orig,
1101                                primary_if->net_dev->dev_addr, ETH_ALEN);
1102                         /* send an announce frame so others will ask for our
1103                          * claims and update their tables.
1104                          */
1105                         batadv_bla_send_announce(bat_priv, backbone_gw);
1106                 }
1107                 rcu_read_unlock();
1108         }
1109 }
1110
1111 /* periodic work to do:
1112  *  * purge structures when they are too old
1113  *  * send announcements
1114  */
1115 static void batadv_bla_periodic_work(struct work_struct *work)
1116 {
1117         struct delayed_work *delayed_work;
1118         struct batadv_priv *bat_priv;
1119         struct batadv_priv_bla *priv_bla;
1120         struct hlist_head *head;
1121         struct batadv_bla_backbone_gw *backbone_gw;
1122         struct batadv_hashtable *hash;
1123         struct batadv_hard_iface *primary_if;
1124         int i;
1125
1126         delayed_work = container_of(work, struct delayed_work, work);
1127         priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
1128         bat_priv = container_of(priv_bla, struct batadv_priv, bla);
1129         primary_if = batadv_primary_if_get_selected(bat_priv);
1130         if (!primary_if)
1131                 goto out;
1132
1133         batadv_bla_purge_claims(bat_priv, primary_if, 0);
1134         batadv_bla_purge_backbone_gw(bat_priv, 0);
1135
1136         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1137                 goto out;
1138
1139         hash = bat_priv->bla.backbone_hash;
1140         if (!hash)
1141                 goto out;
1142
1143         for (i = 0; i < hash->size; i++) {
1144                 head = &hash->table[i];
1145
1146                 rcu_read_lock();
1147                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1148                         if (!batadv_compare_eth(backbone_gw->orig,
1149                                                 primary_if->net_dev->dev_addr))
1150                                 continue;
1151
1152                         backbone_gw->lasttime = jiffies;
1153
1154                         batadv_bla_send_announce(bat_priv, backbone_gw);
1155
1156                         /* request_sent is only set after creation to avoid
1157                          * problems when we are not yet known as backbone gw
1158                          * in the backbone.
1159                          *
1160                          * We can reset this now after we waited some periods
1161                          * to give bridge forward delays and bla group forming
1162                          * some grace time.
1163                          */
1164
1165                         if (atomic_read(&backbone_gw->request_sent) == 0)
1166                                 continue;
1167
1168                         if (!atomic_dec_and_test(&backbone_gw->wait_periods))
1169                                 continue;
1170
1171                         atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
1172                         atomic_set(&backbone_gw->request_sent, 0);
1173                 }
1174                 rcu_read_unlock();
1175         }
1176 out:
1177         if (primary_if)
1178                 batadv_hardif_free_ref(primary_if);
1179
1180         queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1181                            msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1182 }
1183
1184 /* The hash for claim and backbone hash receive the same key because they
1185  * are getting initialized by hash_new with the same key. Reinitializing
1186  * them with to different keys to allow nested locking without generating
1187  * lockdep warnings
1188  */
1189 static struct lock_class_key batadv_claim_hash_lock_class_key;
1190 static struct lock_class_key batadv_backbone_hash_lock_class_key;
1191
1192 /* initialize all bla structures */
1193 int batadv_bla_init(struct batadv_priv *bat_priv)
1194 {
1195         int i;
1196         uint8_t claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
1197         struct batadv_hard_iface *primary_if;
1198         uint16_t crc;
1199         unsigned long entrytime;
1200
1201         spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
1202
1203         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
1204
1205         /* setting claim destination address */
1206         memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3);
1207         bat_priv->bla.claim_dest.type = 0;
1208         primary_if = batadv_primary_if_get_selected(bat_priv);
1209         if (primary_if) {
1210                 crc = crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN);
1211                 bat_priv->bla.claim_dest.group = htons(crc);
1212                 batadv_hardif_free_ref(primary_if);
1213         } else {
1214                 bat_priv->bla.claim_dest.group = 0; /* will be set later */
1215         }
1216
1217         /* initialize the duplicate list */
1218         entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT);
1219         for (i = 0; i < BATADV_DUPLIST_SIZE; i++)
1220                 bat_priv->bla.bcast_duplist[i].entrytime = entrytime;
1221         bat_priv->bla.bcast_duplist_curr = 0;
1222
1223         if (bat_priv->bla.claim_hash)
1224                 return 0;
1225
1226         bat_priv->bla.claim_hash = batadv_hash_new(128);
1227         bat_priv->bla.backbone_hash = batadv_hash_new(32);
1228
1229         if (!bat_priv->bla.claim_hash || !bat_priv->bla.backbone_hash)
1230                 return -ENOMEM;
1231
1232         batadv_hash_set_lock_class(bat_priv->bla.claim_hash,
1233                                    &batadv_claim_hash_lock_class_key);
1234         batadv_hash_set_lock_class(bat_priv->bla.backbone_hash,
1235                                    &batadv_backbone_hash_lock_class_key);
1236
1237         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n");
1238
1239         INIT_DELAYED_WORK(&bat_priv->bla.work, batadv_bla_periodic_work);
1240
1241         queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1242                            msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1243         return 0;
1244 }
1245
1246 /**
1247  * batadv_bla_check_bcast_duplist
1248  * @bat_priv: the bat priv with all the soft interface information
1249  * @skb: contains the bcast_packet to be checked
1250  *
1251  * check if it is on our broadcast list. Another gateway might
1252  * have sent the same packet because it is connected to the same backbone,
1253  * so we have to remove this duplicate.
1254  *
1255  * This is performed by checking the CRC, which will tell us
1256  * with a good chance that it is the same packet. If it is furthermore
1257  * sent by another host, drop it. We allow equal packets from
1258  * the same host however as this might be intended.
1259  */
1260 int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
1261                                    struct sk_buff *skb)
1262 {
1263         int i, curr, ret = 0;
1264         __be32 crc;
1265         struct batadv_bcast_packet *bcast_packet;
1266         struct batadv_bcast_duplist_entry *entry;
1267
1268         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1269
1270         /* calculate the crc ... */
1271         crc = batadv_skb_crc32(skb, (u8 *)(bcast_packet + 1));
1272
1273         spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
1274
1275         for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
1276                 curr = (bat_priv->bla.bcast_duplist_curr + i);
1277                 curr %= BATADV_DUPLIST_SIZE;
1278                 entry = &bat_priv->bla.bcast_duplist[curr];
1279
1280                 /* we can stop searching if the entry is too old ;
1281                  * later entries will be even older
1282                  */
1283                 if (batadv_has_timed_out(entry->entrytime,
1284                                          BATADV_DUPLIST_TIMEOUT))
1285                         break;
1286
1287                 if (entry->crc != crc)
1288                         continue;
1289
1290                 if (batadv_compare_eth(entry->orig, bcast_packet->orig))
1291                         continue;
1292
1293                 /* this entry seems to match: same crc, not too old,
1294                  * and from another gw. therefore return 1 to forbid it.
1295                  */
1296                 ret = 1;
1297                 goto out;
1298         }
1299         /* not found, add a new entry (overwrite the oldest entry)
1300          * and allow it, its the first occurence.
1301          */
1302         curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
1303         curr %= BATADV_DUPLIST_SIZE;
1304         entry = &bat_priv->bla.bcast_duplist[curr];
1305         entry->crc = crc;
1306         entry->entrytime = jiffies;
1307         memcpy(entry->orig, bcast_packet->orig, ETH_ALEN);
1308         bat_priv->bla.bcast_duplist_curr = curr;
1309
1310 out:
1311         spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
1312
1313         return ret;
1314 }
1315
1316
1317
1318 /* @bat_priv: the bat priv with all the soft interface information
1319  * @orig: originator mac address
1320  *
1321  * check if the originator is a gateway for any VLAN ID.
1322  *
1323  * returns 1 if it is found, 0 otherwise
1324  */
1325 int batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, uint8_t *orig)
1326 {
1327         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1328         struct hlist_head *head;
1329         struct batadv_bla_backbone_gw *backbone_gw;
1330         int i;
1331
1332         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1333                 return 0;
1334
1335         if (!hash)
1336                 return 0;
1337
1338         for (i = 0; i < hash->size; i++) {
1339                 head = &hash->table[i];
1340
1341                 rcu_read_lock();
1342                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1343                         if (batadv_compare_eth(backbone_gw->orig, orig)) {
1344                                 rcu_read_unlock();
1345                                 return 1;
1346                         }
1347                 }
1348                 rcu_read_unlock();
1349         }
1350
1351         return 0;
1352 }
1353
1354
1355 /**
1356  * batadv_bla_is_backbone_gw
1357  * @skb: the frame to be checked
1358  * @orig_node: the orig_node of the frame
1359  * @hdr_size: maximum length of the frame
1360  *
1361  * bla_is_backbone_gw inspects the skb for the VLAN ID and returns 1
1362  * if the orig_node is also a gateway on the soft interface, otherwise it
1363  * returns 0.
1364  */
1365 int batadv_bla_is_backbone_gw(struct sk_buff *skb,
1366                               struct batadv_orig_node *orig_node, int hdr_size)
1367 {
1368         struct ethhdr *ethhdr;
1369         struct vlan_ethhdr *vhdr;
1370         struct batadv_bla_backbone_gw *backbone_gw;
1371         unsigned short vid = BATADV_NO_FLAGS;
1372
1373         if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
1374                 return 0;
1375
1376         /* first, find out the vid. */
1377         if (!pskb_may_pull(skb, hdr_size + ETH_HLEN))
1378                 return 0;
1379
1380         ethhdr = (struct ethhdr *)(((uint8_t *)skb->data) + hdr_size);
1381
1382         if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
1383                 if (!pskb_may_pull(skb, hdr_size + sizeof(struct vlan_ethhdr)))
1384                         return 0;
1385
1386                 vhdr = (struct vlan_ethhdr *)(skb->data + hdr_size);
1387                 vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
1388                 vid |= BATADV_VLAN_HAS_TAG;
1389         }
1390
1391         /* see if this originator is a backbone gw for this VLAN */
1392         backbone_gw = batadv_backbone_hash_find(orig_node->bat_priv,
1393                                                 orig_node->orig, vid);
1394         if (!backbone_gw)
1395                 return 0;
1396
1397         batadv_backbone_gw_free_ref(backbone_gw);
1398         return 1;
1399 }
1400
1401 /* free all bla structures (for softinterface free or module unload) */
1402 void batadv_bla_free(struct batadv_priv *bat_priv)
1403 {
1404         struct batadv_hard_iface *primary_if;
1405
1406         cancel_delayed_work_sync(&bat_priv->bla.work);
1407         primary_if = batadv_primary_if_get_selected(bat_priv);
1408
1409         if (bat_priv->bla.claim_hash) {
1410                 batadv_bla_purge_claims(bat_priv, primary_if, 1);
1411                 batadv_hash_destroy(bat_priv->bla.claim_hash);
1412                 bat_priv->bla.claim_hash = NULL;
1413         }
1414         if (bat_priv->bla.backbone_hash) {
1415                 batadv_bla_purge_backbone_gw(bat_priv, 1);
1416                 batadv_hash_destroy(bat_priv->bla.backbone_hash);
1417                 bat_priv->bla.backbone_hash = NULL;
1418         }
1419         if (primary_if)
1420                 batadv_hardif_free_ref(primary_if);
1421 }
1422
1423 /**
1424  * batadv_bla_rx
1425  * @bat_priv: the bat priv with all the soft interface information
1426  * @skb: the frame to be checked
1427  * @vid: the VLAN ID of the frame
1428  * @is_bcast: the packet came in a broadcast packet type.
1429  *
1430  * bla_rx avoidance checks if:
1431  *  * we have to race for a claim
1432  *  * if the frame is allowed on the LAN
1433  *
1434  * in these cases, the skb is further handled by this function and
1435  * returns 1, otherwise it returns 0 and the caller shall further
1436  * process the skb.
1437  */
1438 int batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1439                   unsigned short vid, bool is_bcast)
1440 {
1441         struct ethhdr *ethhdr;
1442         struct batadv_bla_claim search_claim, *claim = NULL;
1443         struct batadv_hard_iface *primary_if;
1444         int ret;
1445
1446         ethhdr = eth_hdr(skb);
1447
1448         primary_if = batadv_primary_if_get_selected(bat_priv);
1449         if (!primary_if)
1450                 goto handled;
1451
1452         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1453                 goto allow;
1454
1455
1456         if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1457                 /* don't allow broadcasts while requests are in flight */
1458                 if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast)
1459                         goto handled;
1460
1461         memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
1462         search_claim.vid = vid;
1463         claim = batadv_claim_hash_find(bat_priv, &search_claim);
1464
1465         if (!claim) {
1466                 /* possible optimization: race for a claim */
1467                 /* No claim exists yet, claim it for us!
1468                  */
1469                 batadv_handle_claim(bat_priv, primary_if,
1470                                     primary_if->net_dev->dev_addr,
1471                                     ethhdr->h_source, vid);
1472                 goto allow;
1473         }
1474
1475         /* if it is our own claim ... */
1476         if (batadv_compare_eth(claim->backbone_gw->orig,
1477                                primary_if->net_dev->dev_addr)) {
1478                 /* ... allow it in any case */
1479                 claim->lasttime = jiffies;
1480                 goto allow;
1481         }
1482
1483         /* if it is a broadcast ... */
1484         if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) {
1485                 /* ... drop it. the responsible gateway is in charge.
1486                  *
1487                  * We need to check is_bcast because with the gateway
1488                  * feature, broadcasts (like DHCP requests) may be sent
1489                  * using a unicast packet type.
1490                  */
1491                 goto handled;
1492         } else {
1493                 /* seems the client considers us as its best gateway.
1494                  * send a claim and update the claim table
1495                  * immediately.
1496                  */
1497                 batadv_handle_claim(bat_priv, primary_if,
1498                                     primary_if->net_dev->dev_addr,
1499                                     ethhdr->h_source, vid);
1500                 goto allow;
1501         }
1502 allow:
1503         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1504         ret = 0;
1505         goto out;
1506
1507 handled:
1508         kfree_skb(skb);
1509         ret = 1;
1510
1511 out:
1512         if (primary_if)
1513                 batadv_hardif_free_ref(primary_if);
1514         if (claim)
1515                 batadv_claim_free_ref(claim);
1516         return ret;
1517 }
1518
1519 /**
1520  * batadv_bla_tx
1521  * @bat_priv: the bat priv with all the soft interface information
1522  * @skb: the frame to be checked
1523  * @vid: the VLAN ID of the frame
1524  *
1525  * bla_tx checks if:
1526  *  * a claim was received which has to be processed
1527  *  * the frame is allowed on the mesh
1528  *
1529  * in these cases, the skb is further handled by this function and
1530  * returns 1, otherwise it returns 0 and the caller shall further
1531  * process the skb.
1532  *
1533  * This call might reallocate skb data.
1534  */
1535 int batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1536                   unsigned short vid)
1537 {
1538         struct ethhdr *ethhdr;
1539         struct batadv_bla_claim search_claim, *claim = NULL;
1540         struct batadv_hard_iface *primary_if;
1541         int ret = 0;
1542
1543         primary_if = batadv_primary_if_get_selected(bat_priv);
1544         if (!primary_if)
1545                 goto out;
1546
1547         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1548                 goto allow;
1549
1550         /* in VLAN case, the mac header might not be set. */
1551         skb_reset_mac_header(skb);
1552
1553         if (batadv_bla_process_claim(bat_priv, primary_if, skb))
1554                 goto handled;
1555
1556         ethhdr = eth_hdr(skb);
1557
1558         if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1559                 /* don't allow broadcasts while requests are in flight */
1560                 if (is_multicast_ether_addr(ethhdr->h_dest))
1561                         goto handled;
1562
1563         memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
1564         search_claim.vid = vid;
1565
1566         claim = batadv_claim_hash_find(bat_priv, &search_claim);
1567
1568         /* if no claim exists, allow it. */
1569         if (!claim)
1570                 goto allow;
1571
1572         /* check if we are responsible. */
1573         if (batadv_compare_eth(claim->backbone_gw->orig,
1574                                primary_if->net_dev->dev_addr)) {
1575                 /* if yes, the client has roamed and we have
1576                  * to unclaim it.
1577                  */
1578                 batadv_handle_unclaim(bat_priv, primary_if,
1579                                       primary_if->net_dev->dev_addr,
1580                                       ethhdr->h_source, vid);
1581                 goto allow;
1582         }
1583
1584         /* check if it is a multicast/broadcast frame */
1585         if (is_multicast_ether_addr(ethhdr->h_dest)) {
1586                 /* drop it. the responsible gateway has forwarded it into
1587                  * the backbone network.
1588                  */
1589                 goto handled;
1590         } else {
1591                 /* we must allow it. at least if we are
1592                  * responsible for the DESTINATION.
1593                  */
1594                 goto allow;
1595         }
1596 allow:
1597         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1598         ret = 0;
1599         goto out;
1600 handled:
1601         ret = 1;
1602 out:
1603         if (primary_if)
1604                 batadv_hardif_free_ref(primary_if);
1605         if (claim)
1606                 batadv_claim_free_ref(claim);
1607         return ret;
1608 }
1609
1610 int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset)
1611 {
1612         struct net_device *net_dev = (struct net_device *)seq->private;
1613         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1614         struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
1615         struct batadv_bla_claim *claim;
1616         struct batadv_hard_iface *primary_if;
1617         struct hlist_head *head;
1618         uint32_t i;
1619         bool is_own;
1620         uint8_t *primary_addr;
1621
1622         primary_if = batadv_seq_print_text_primary_if_get(seq);
1623         if (!primary_if)
1624                 goto out;
1625
1626         primary_addr = primary_if->net_dev->dev_addr;
1627         seq_printf(seq,
1628                    "Claims announced for the mesh %s (orig %pM, group id %#.4x)\n",
1629                    net_dev->name, primary_addr,
1630                    ntohs(bat_priv->bla.claim_dest.group));
1631         seq_printf(seq, "   %-17s    %-5s    %-17s [o] (%-6s)\n",
1632                    "Client", "VID", "Originator", "CRC");
1633         for (i = 0; i < hash->size; i++) {
1634                 head = &hash->table[i];
1635
1636                 rcu_read_lock();
1637                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
1638                         is_own = batadv_compare_eth(claim->backbone_gw->orig,
1639                                                     primary_addr);
1640                         seq_printf(seq, " * %pM on %5d by %pM [%c] (%#.4x)\n",
1641                                    claim->addr, BATADV_PRINT_VID(claim->vid),
1642                                    claim->backbone_gw->orig,
1643                                    (is_own ? 'x' : ' '),
1644                                    claim->backbone_gw->crc);
1645                 }
1646                 rcu_read_unlock();
1647         }
1648 out:
1649         if (primary_if)
1650                 batadv_hardif_free_ref(primary_if);
1651         return 0;
1652 }
1653
1654 int batadv_bla_backbone_table_seq_print_text(struct seq_file *seq, void *offset)
1655 {
1656         struct net_device *net_dev = (struct net_device *)seq->private;
1657         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1658         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1659         struct batadv_bla_backbone_gw *backbone_gw;
1660         struct batadv_hard_iface *primary_if;
1661         struct hlist_head *head;
1662         int secs, msecs;
1663         uint32_t i;
1664         bool is_own;
1665         uint8_t *primary_addr;
1666
1667         primary_if = batadv_seq_print_text_primary_if_get(seq);
1668         if (!primary_if)
1669                 goto out;
1670
1671         primary_addr = primary_if->net_dev->dev_addr;
1672         seq_printf(seq,
1673                    "Backbones announced for the mesh %s (orig %pM, group id %#.4x)\n",
1674                    net_dev->name, primary_addr,
1675                    ntohs(bat_priv->bla.claim_dest.group));
1676         seq_printf(seq, "   %-17s    %-5s %-9s (%-6s)\n",
1677                    "Originator", "VID", "last seen", "CRC");
1678         for (i = 0; i < hash->size; i++) {
1679                 head = &hash->table[i];
1680
1681                 rcu_read_lock();
1682                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1683                         msecs = jiffies_to_msecs(jiffies -
1684                                                  backbone_gw->lasttime);
1685                         secs = msecs / 1000;
1686                         msecs = msecs % 1000;
1687
1688                         is_own = batadv_compare_eth(backbone_gw->orig,
1689                                                     primary_addr);
1690                         if (is_own)
1691                                 continue;
1692
1693                         seq_printf(seq, " * %pM on %5d %4i.%03is (%#.4x)\n",
1694                                    backbone_gw->orig,
1695                                    BATADV_PRINT_VID(backbone_gw->vid), secs,
1696                                    msecs, backbone_gw->crc);
1697                 }
1698                 rcu_read_unlock();
1699         }
1700 out:
1701         if (primary_if)
1702                 batadv_hardif_free_ref(primary_if);
1703         return 0;
1704 }