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