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