net/batman-adv/bridge_loop_avoidance.c

   1 /* Copyright (C) 2011-2016  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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "bridge_loop_avoidance.h"
  19 #include "main.h"
  20
  21 #include <linux/atomic.h>
  22 #include <linux/byteorder/generic.h>
  23 #include <linux/compiler.h>
  24 #include <linux/crc16.h>
  25 #include <linux/errno.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/fs.h>
  28 #include <linux/if_arp.h>
  29 #include <linux/if_ether.h>
  30 #include <linux/if_vlan.h>
  31 #include <linux/jhash.h>
  32 #include <linux/jiffies.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kref.h>
  35 #include <linux/list.h>
  36 #include <linux/lockdep.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/rculist.h>
  39 #include <linux/rcupdate.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/skbuff.h>
  42 #include <linux/slab.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/stddef.h>
  45 #include <linux/string.h>
  46 #include <linux/workqueue.h>
  47 #include <net/arp.h>
  48
  49 #include "hard-interface.h"
  50 #include "hash.h"
  51 #include "originator.h"
  52 #include "packet.h"
  53 #include "translation-table.h"
  54
  55 static const u8 batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
  56
  57 static void batadv_bla_periodic_work(struct work_struct *work);
  58 static void
  59 batadv_bla_send_announce(struct batadv_priv *bat_priv,
  60                          struct batadv_bla_backbone_gw *backbone_gw);
  61
  62 /**
  63  * batadv_choose_claim - choose the right bucket for a claim.
  64  * @data: data to hash
  65  * @size: size of the hash table
  66  *
  67  * Return: the hash index of the claim
  68  */
  69 static inline u32 batadv_choose_claim(const void *data, u32 size)
  70 {
  71         struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
  72         u32 hash = 0;
  73
  74         hash = jhash(&claim->addr, sizeof(claim->addr), hash);
  75         hash = jhash(&claim->vid, sizeof(claim->vid), hash);
  76
  77         return hash % size;
  78 }
  79
  80 /**
  81  * batadv_choose_backbone_gw - choose the right bucket for a backbone gateway.
  82  * @data: data to hash
  83  * @size: size of the hash table
  84  *
  85  * Return: the hash index of the backbone gateway
  86  */
  87 static inline u32 batadv_choose_backbone_gw(const void *data, u32 size)
  88 {
  89         const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
  90         u32 hash = 0;
  91
  92         hash = jhash(&claim->addr, sizeof(claim->addr), hash);
  93         hash = jhash(&claim->vid, sizeof(claim->vid), hash);
  94
  95         return hash % size;
  96 }
  97
  98 /**
  99  * batadv_compare_backbone_gw - compare address and vid of two backbone gws
 100  * @node: list node of the first entry to compare
 101  * @data2: pointer to the second backbone gateway
 102  *
 103  * Return: 1 if the backbones have the same data, 0 otherwise
 104  */
 105 static int batadv_compare_backbone_gw(const struct hlist_node *node,
 106                                       const void *data2)
 107 {
 108         const void *data1 = container_of(node, struct batadv_bla_backbone_gw,
 109                                          hash_entry);
 110         const struct batadv_bla_backbone_gw *gw1 = data1;
 111         const struct batadv_bla_backbone_gw *gw2 = data2;
 112
 113         if (!batadv_compare_eth(gw1->orig, gw2->orig))
 114                 return 0;
 115
 116         if (gw1->vid != gw2->vid)
 117                 return 0;
 118
 119         return 1;
 120 }
 121
 122 /**
 123  * batadv_compare_backbone_gw - compare address and vid of two claims
 124  * @node: list node of the first entry to compare
 125  * @data2: pointer to the second claims
 126  *
 127  * Return: 1 if the claim have the same data, 0 otherwise
 128  */
 129 static int batadv_compare_claim(const struct hlist_node *node,
 130                                 const void *data2)
 131 {
 132         const void *data1 = container_of(node, struct batadv_bla_claim,
 133                                          hash_entry);
 134         const struct batadv_bla_claim *cl1 = data1;
 135         const struct batadv_bla_claim *cl2 = data2;
 136
 137         if (!batadv_compare_eth(cl1->addr, cl2->addr))
 138                 return 0;
 139
 140         if (cl1->vid != cl2->vid)
 141                 return 0;
 142
 143         return 1;
 144 }
 145
 146 /**
 147  * batadv_backbone_gw_release - release backbone gw from lists and queue for
 148  *  free after rcu grace period
 149  * @ref: kref pointer of the backbone gw
 150  */
 151 static void batadv_backbone_gw_release(struct kref *ref)
 152 {
 153         struct batadv_bla_backbone_gw *backbone_gw;
 154
 155         backbone_gw = container_of(ref, struct batadv_bla_backbone_gw,
 156                                    refcount);
 157
 158         kfree_rcu(backbone_gw, rcu);
 159 }
 160
 161 /**
 162  * batadv_backbone_gw_free_ref - decrement the backbone gw refcounter and
 163  *  possibly release it
 164  * @backbone_gw: backbone gateway to be free'd
 165  */
 166 static void
 167 batadv_backbone_gw_free_ref(struct batadv_bla_backbone_gw *backbone_gw)
 168 {
 169         kref_put(&backbone_gw->refcount, batadv_backbone_gw_release);
 170 }
 171
 172 /**
 173  * batadv_claim_release - release claim from lists and queue for free after rcu
 174  *  grace period
 175  * @ref: kref pointer of the claim
 176  */
 177 static void batadv_claim_release(struct kref *ref)
 178 {
 179         struct batadv_bla_claim *claim;
 180
 181         claim = container_of(ref, struct batadv_bla_claim, refcount);
 182
 183         batadv_backbone_gw_free_ref(claim->backbone_gw);
 184         kfree_rcu(claim, rcu);
 185 }
 186
 187 /**
 188  * batadv_claim_free_ref - decrement the claim refcounter and possibly
 189  *  release it
 190  * @claim: claim to be free'd
 191  */
 192 static void batadv_claim_free_ref(struct batadv_bla_claim *claim)
 193 {
 194         kref_put(&claim->refcount, batadv_claim_release);
 195 }
 196
 197 /**
 198  * batadv_claim_hash_find - looks for a claim in the claim hash
 199  * @bat_priv: the bat priv with all the soft interface information
 200  * @data: search data (may be local/static data)
 201  *
 202  * Return: claim if found or NULL otherwise.
 203  */
 204 static struct batadv_bla_claim
 205 *batadv_claim_hash_find(struct batadv_priv *bat_priv,
 206                         struct batadv_bla_claim *data)
 207 {
 208         struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
 209         struct hlist_head *head;
 210         struct batadv_bla_claim *claim;
 211         struct batadv_bla_claim *claim_tmp = NULL;
 212         int index;
 213
 214         if (!hash)
 215                 return NULL;
 216
 217         index = batadv_choose_claim(data, hash->size);
 218         head = &hash->table[index];
 219
 220         rcu_read_lock();
 221         hlist_for_each_entry_rcu(claim, head, hash_entry) {
 222                 if (!batadv_compare_claim(&claim->hash_entry, data))
 223                         continue;
 224
 225                 if (!kref_get_unless_zero(&claim->refcount))
 226                         continue;
 227
 228                 claim_tmp = claim;
 229                 break;
 230         }
 231         rcu_read_unlock();
 232
 233         return claim_tmp;
 234 }
 235
 236 /**
 237  * batadv_backbone_hash_find - looks for a backbone gateway in the hash
 238  * @bat_priv: the bat priv with all the soft interface information
 239  * @addr: the address of the originator
 240  * @vid: the VLAN ID
 241  *
 242  * Return: backbone gateway if found or NULL otherwise
 243  */
 244 static struct batadv_bla_backbone_gw *
 245 batadv_backbone_hash_find(struct batadv_priv *bat_priv, u8 *addr,
 246                           unsigned short vid)
 247 {
 248         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
 249         struct hlist_head *head;
 250         struct batadv_bla_backbone_gw search_entry, *backbone_gw;
 251         struct batadv_bla_backbone_gw *backbone_gw_tmp = NULL;
 252         int index;
 253
 254         if (!hash)
 255                 return NULL;
 256
 257         ether_addr_copy(search_entry.orig, addr);
 258         search_entry.vid = vid;
 259
 260         index = batadv_choose_backbone_gw(&search_entry, hash->size);
 261         head = &hash->table[index];
 262
 263         rcu_read_lock();
 264         hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
 265                 if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry,
 266                                                 &search_entry))
 267                         continue;
 268
 269                 if (!kref_get_unless_zero(&backbone_gw->refcount))
 270                         continue;
 271
 272                 backbone_gw_tmp = backbone_gw;
 273                 break;
 274         }
 275         rcu_read_unlock();
 276
 277         return backbone_gw_tmp;
 278 }
 279
 280 /**
 281  * batadv_bla_del_backbone_claims - delete all claims for a backbone
 282  * @backbone_gw: backbone gateway where the claims should be removed
 283  */
 284 static void
 285 batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw)
 286 {
 287         struct batadv_hashtable *hash;
 288         struct hlist_node *node_tmp;
 289         struct hlist_head *head;
 290         struct batadv_bla_claim *claim;
 291         int i;
 292         spinlock_t *list_lock;  /* protects write access to the hash lists */
 293
 294         hash = backbone_gw->bat_priv->bla.claim_hash;
 295         if (!hash)
 296                 return;
 297
 298         for (i = 0; i < hash->size; i++) {
 299                 head = &hash->table[i];
 300                 list_lock = &hash->list_locks[i];
 301
 302                 spin_lock_bh(list_lock);
 303                 hlist_for_each_entry_safe(claim, node_tmp,
 304                                           head, hash_entry) {
 305                         if (claim->backbone_gw != backbone_gw)
 306                                 continue;
 307
 308                         batadv_claim_free_ref(claim);
 309                         hlist_del_rcu(&claim->hash_entry);
 310                 }
 311                 spin_unlock_bh(list_lock);
 312         }
 313
 314         /* all claims gone, initialize CRC */
 315         spin_lock_bh(&backbone_gw->crc_lock);
 316         backbone_gw->crc = BATADV_BLA_CRC_INIT;
 317         spin_unlock_bh(&backbone_gw->crc_lock);
 318 }
 319
 320 /**
 321  * batadv_bla_send_claim - sends a claim frame according to the provided info
 322  * @bat_priv: the bat priv with all the soft interface information
 323  * @mac: the mac address to be announced within the claim
 324  * @vid: the VLAN ID
 325  * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...)
 326  */
 327 static void batadv_bla_send_claim(struct batadv_priv *bat_priv, u8 *mac,
 328                                   unsigned short vid, int claimtype)
 329 {
 330         struct sk_buff *skb;
 331         struct ethhdr *ethhdr;
 332         struct batadv_hard_iface *primary_if;
 333         struct net_device *soft_iface;
 334         u8 *hw_src;
 335         struct batadv_bla_claim_dst local_claim_dest;
 336         __be32 zeroip = 0;
 337
 338         primary_if = batadv_primary_if_get_selected(bat_priv);
 339         if (!primary_if)
 340                 return;
 341
 342         memcpy(&local_claim_dest, &bat_priv->bla.claim_dest,
 343                sizeof(local_claim_dest));
 344         local_claim_dest.type = claimtype;
 345
 346         soft_iface = primary_if->soft_iface;
 347
 348         skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
 349                          /* IP DST: 0.0.0.0 */
 350                          zeroip,
 351                          primary_if->soft_iface,
 352                          /* IP SRC: 0.0.0.0 */
 353                          zeroip,
 354                          /* Ethernet DST: Broadcast */
 355                          NULL,
 356                          /* Ethernet SRC/HW SRC:  originator mac */
 357                          primary_if->net_dev->dev_addr,
 358                          /* HW DST: FF:43:05:XX:YY:YY
 359                           * with XX   = claim type
 360                           * and YY:YY = group id
 361                           */
 362                          (u8 *)&local_claim_dest);
 363
 364         if (!skb)
 365                 goto out;
 366
 367         ethhdr = (struct ethhdr *)skb->data;
 368         hw_src = (u8 *)ethhdr + ETH_HLEN + sizeof(struct arphdr);
 369
 370         /* now we pretend that the client would have sent this ... */
 371         switch (claimtype) {
 372         case BATADV_CLAIM_TYPE_CLAIM:
 373                 /* normal claim frame
 374                  * set Ethernet SRC to the clients mac
 375                  */
 376                 ether_addr_copy(ethhdr->h_source, mac);
 377                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 378                            "bla_send_claim(): CLAIM %pM on vid %d\n", mac,
 379                            BATADV_PRINT_VID(vid));
 380                 break;
 381         case BATADV_CLAIM_TYPE_UNCLAIM:
 382                 /* unclaim frame
 383                  * set HW SRC to the clients mac
 384                  */
 385                 ether_addr_copy(hw_src, mac);
 386                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 387                            "bla_send_claim(): UNCLAIM %pM on vid %d\n", mac,
 388                            BATADV_PRINT_VID(vid));
 389                 break;
 390         case BATADV_CLAIM_TYPE_ANNOUNCE:
 391                 /* announcement frame
 392                  * set HW SRC to the special mac containg the crc
 393                  */
 394                 ether_addr_copy(hw_src, mac);
 395                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 396                            "bla_send_claim(): ANNOUNCE of %pM on vid %d\n",
 397                            ethhdr->h_source, BATADV_PRINT_VID(vid));
 398                 break;
 399         case BATADV_CLAIM_TYPE_REQUEST:
 400                 /* request frame
 401                  * set HW SRC and header destination to the receiving backbone
 402                  * gws mac
 403                  */
 404                 ether_addr_copy(hw_src, mac);
 405                 ether_addr_copy(ethhdr->h_dest, mac);
 406                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 407                            "bla_send_claim(): REQUEST of %pM to %pM on vid %d\n",
 408                            ethhdr->h_source, ethhdr->h_dest,
 409                            BATADV_PRINT_VID(vid));
 410                 break;
 411         }
 412
 413         if (vid & BATADV_VLAN_HAS_TAG)
 414                 skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
 415                                       vid & VLAN_VID_MASK);
 416
 417         skb_reset_mac_header(skb);
 418         skb->protocol = eth_type_trans(skb, soft_iface);
 419         batadv_inc_counter(bat_priv, BATADV_CNT_RX);
 420         batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
 421                            skb->len + ETH_HLEN);
 422         soft_iface->last_rx = jiffies;
 423
 424         netif_rx(skb);
 425 out:
 426         if (primary_if)
 427                 batadv_hardif_free_ref(primary_if);
 428 }
 429
 430 /**
 431  * batadv_bla_get_backbone_gw - finds or creates a backbone gateway
 432  * @bat_priv: the bat priv with all the soft interface information
 433  * @orig: the mac address of the originator
 434  * @vid: the VLAN ID
 435  * @own_backbone: set if the requested backbone is local
 436  *
 437  * Return: the (possibly created) backbone gateway or NULL on error
 438  */
 439 static struct batadv_bla_backbone_gw *
 440 batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *orig,
 441                            unsigned short vid, bool own_backbone)
 442 {
 443         struct batadv_bla_backbone_gw *entry;
 444         struct batadv_orig_node *orig_node;
 445         int hash_added;
 446
 447         entry = batadv_backbone_hash_find(bat_priv, orig, vid);
 448
 449         if (entry)
 450                 return entry;
 451
 452         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 453                    "bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n",
 454                    orig, BATADV_PRINT_VID(vid));
 455
 456         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 457         if (!entry)
 458                 return NULL;
 459
 460         entry->vid = vid;
 461         entry->lasttime = jiffies;
 462         entry->crc = BATADV_BLA_CRC_INIT;
 463         entry->bat_priv = bat_priv;
 464         spin_lock_init(&entry->crc_lock);
 465         atomic_set(&entry->request_sent, 0);
 466         atomic_set(&entry->wait_periods, 0);
 467         ether_addr_copy(entry->orig, orig);
 468
 469         /* one for the hash, one for returning */
 470         kref_init(&entry->refcount);
 471         kref_get(&entry->refcount);
 472
 473         hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
 474                                      batadv_compare_backbone_gw,
 475                                      batadv_choose_backbone_gw, entry,
 476                                      &entry->hash_entry);
 477
 478         if (unlikely(hash_added != 0)) {
 479                 /* hash failed, free the structure */
 480                 kfree(entry);
 481                 return NULL;
 482         }
 483
 484         /* this is a gateway now, remove any TT entry on this VLAN */
 485         orig_node = batadv_orig_hash_find(bat_priv, orig);
 486         if (orig_node) {
 487                 batadv_tt_global_del_orig(bat_priv, orig_node, vid,
 488                                           "became a backbone gateway");
 489                 batadv_orig_node_free_ref(orig_node);
 490         }
 491
 492         if (own_backbone) {
 493                 batadv_bla_send_announce(bat_priv, entry);
 494
 495                 /* this will be decreased in the worker thread */
 496                 atomic_inc(&entry->request_sent);
 497                 atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
 498                 atomic_inc(&bat_priv->bla.num_requests);
 499         }
 500
 501         return entry;
 502 }
 503
 504 /**
 505  * batadv_bla_update_own_backbone_gw - updates the own backbone gw for a VLAN
 506  * @bat_priv: the bat priv with all the soft interface information
 507  * @primary_if: the selected primary interface
 508  * @vid: VLAN identifier
 509  *
 510  * update or add the own backbone gw to make sure we announce
 511  * where we receive other backbone gws
 512  */
 513 static void
 514 batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv,
 515                                   struct batadv_hard_iface *primary_if,
 516                                   unsigned short vid)
 517 {
 518         struct batadv_bla_backbone_gw *backbone_gw;
 519
 520         backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
 521                                                  primary_if->net_dev->dev_addr,
 522                                                  vid, true);
 523         if (unlikely(!backbone_gw))
 524                 return;
 525
 526         backbone_gw->lasttime = jiffies;
 527         batadv_backbone_gw_free_ref(backbone_gw);
 528 }
 529
 530 /**
 531  * batadv_bla_answer_request - answer a bla request by sending own claims
 532  * @bat_priv: the bat priv with all the soft interface information
 533  * @primary_if: interface where the request came on
 534  * @vid: the vid where the request came on
 535  *
 536  * Repeat all of our own claims, and finally send an ANNOUNCE frame
 537  * to allow the requester another check if the CRC is correct now.
 538  */
 539 static void batadv_bla_answer_request(struct batadv_priv *bat_priv,
 540                                       struct batadv_hard_iface *primary_if,
 541                                       unsigned short vid)
 542 {
 543         struct hlist_head *head;
 544         struct batadv_hashtable *hash;
 545         struct batadv_bla_claim *claim;
 546         struct batadv_bla_backbone_gw *backbone_gw;
 547         int i;
 548
 549         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 550                    "bla_answer_request(): received a claim request, send all of our own claims again\n");
 551
 552         backbone_gw = batadv_backbone_hash_find(bat_priv,
 553                                                 primary_if->net_dev->dev_addr,
 554                                                 vid);
 555         if (!backbone_gw)
 556                 return;
 557
 558         hash = bat_priv->bla.claim_hash;
 559         for (i = 0; i < hash->size; i++) {
 560                 head = &hash->table[i];
 561
 562                 rcu_read_lock();
 563                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
 564                         /* only own claims are interesting */
 565                         if (claim->backbone_gw != backbone_gw)
 566                                 continue;
 567
 568                         batadv_bla_send_claim(bat_priv, claim->addr, claim->vid,
 569                                               BATADV_CLAIM_TYPE_CLAIM);
 570                 }
 571                 rcu_read_unlock();
 572         }
 573
 574         /* finally, send an announcement frame */
 575         batadv_bla_send_announce(bat_priv, backbone_gw);
 576         batadv_backbone_gw_free_ref(backbone_gw);
 577 }
 578
 579 /**
 580  * batadv_bla_send_request - send a request to repeat claims
 581  * @backbone_gw: the backbone gateway from whom we are out of sync
 582  *
 583  * When the crc is wrong, ask the backbone gateway for a full table update.
 584  * After the request, it will repeat all of his own claims and finally
 585  * send an announcement claim with which we can check again.
 586  */
 587 static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw)
 588 {
 589         /* first, remove all old entries */
 590         batadv_bla_del_backbone_claims(backbone_gw);
 591
 592         batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
 593                    "Sending REQUEST to %pM\n", backbone_gw->orig);
 594
 595         /* send request */
 596         batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig,
 597                               backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST);
 598
 599         /* no local broadcasts should be sent or received, for now. */
 600         if (!atomic_read(&backbone_gw->request_sent)) {
 601                 atomic_inc(&backbone_gw->bat_priv->bla.num_requests);
 602                 atomic_set(&backbone_gw->request_sent, 1);
 603         }
 604 }
 605
 606 /**
 607  * batadv_bla_send_announce - Send an announcement frame
 608  * @bat_priv: the bat priv with all the soft interface information
 609  * @backbone_gw: our backbone gateway which should be announced
 610  */
 611 static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
 612                                      struct batadv_bla_backbone_gw *backbone_gw)
 613 {
 614         u8 mac[ETH_ALEN];
 615         __be16 crc;
 616
 617         memcpy(mac, batadv_announce_mac, 4);
 618         spin_lock_bh(&backbone_gw->crc_lock);
 619         crc = htons(backbone_gw->crc);
 620         spin_unlock_bh(&backbone_gw->crc_lock);
 621         memcpy(&mac[4], &crc, 2);
 622
 623         batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid,
 624                               BATADV_CLAIM_TYPE_ANNOUNCE);
 625 }
 626
 627 /**
 628  * batadv_bla_add_claim - Adds a claim in the claim hash
 629  * @bat_priv: the bat priv with all the soft interface information
 630  * @mac: the mac address of the claim
 631  * @vid: the VLAN ID of the frame
 632  * @backbone_gw: the backbone gateway which claims it
 633  */
 634 static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 635                                  const u8 *mac, const unsigned short vid,
 636                                  struct batadv_bla_backbone_gw *backbone_gw)
 637 {
 638         struct batadv_bla_claim *claim;
 639         struct batadv_bla_claim search_claim;
 640         int hash_added;
 641
 642         ether_addr_copy(search_claim.addr, mac);
 643         search_claim.vid = vid;
 644         claim = batadv_claim_hash_find(bat_priv, &search_claim);
 645
 646         /* create a new claim entry if it does not exist yet. */
 647         if (!claim) {
 648                 claim = kzalloc(sizeof(*claim), GFP_ATOMIC);
 649                 if (!claim)
 650                         return;
 651
 652                 ether_addr_copy(claim->addr, mac);
 653                 claim->vid = vid;
 654                 claim->lasttime = jiffies;
 655                 claim->backbone_gw = backbone_gw;
 656
 657                 kref_init(&claim->refcount);
 658                 kref_get(&claim->refcount);
 659                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 660                            "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n",
 661                            mac, BATADV_PRINT_VID(vid));
 662                 hash_added = batadv_hash_add(bat_priv->bla.claim_hash,
 663                                              batadv_compare_claim,
 664                                              batadv_choose_claim, claim,
 665                                              &claim->hash_entry);
 666
 667                 if (unlikely(hash_added != 0)) {
 668                         /* only local changes happened. */
 669                         kfree(claim);
 670                         return;
 671                 }
 672         } else {
 673                 claim->lasttime = jiffies;
 674                 if (claim->backbone_gw == backbone_gw)
 675                         /* no need to register a new backbone */
 676                         goto claim_free_ref;
 677
 678                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 679                            "bla_add_claim(): changing ownership for %pM, vid %d\n",
 680                            mac, BATADV_PRINT_VID(vid));
 681
 682                 spin_lock_bh(&claim->backbone_gw->crc_lock);
 683                 claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 684                 spin_unlock_bh(&claim->backbone_gw->crc_lock);
 685                 batadv_backbone_gw_free_ref(claim->backbone_gw);
 686         }
 687         /* set (new) backbone gw */
 688         kref_get(&backbone_gw->refcount);
 689         claim->backbone_gw = backbone_gw;
 690
 691         spin_lock_bh(&backbone_gw->crc_lock);
 692         backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 693         spin_unlock_bh(&backbone_gw->crc_lock);
 694         backbone_gw->lasttime = jiffies;
 695
 696 claim_free_ref:
 697         batadv_claim_free_ref(claim);
 698 }
 699
 700 /**
 701  * batadv_bla_del_claim - delete a claim from the claim hash
 702  * @bat_priv: the bat priv with all the soft interface information
 703  * @mac: mac address of the claim to be removed
 704  * @vid: VLAN id for the claim to be removed
 705  */
 706 static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
 707                                  const u8 *mac, const unsigned short vid)
 708 {
 709         struct batadv_bla_claim search_claim, *claim;
 710
 711         ether_addr_copy(search_claim.addr, mac);
 712         search_claim.vid = vid;
 713         claim = batadv_claim_hash_find(bat_priv, &search_claim);
 714         if (!claim)
 715                 return;
 716
 717         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n",
 718                    mac, BATADV_PRINT_VID(vid));
 719
 720         batadv_hash_remove(bat_priv->bla.claim_hash, batadv_compare_claim,
 721                            batadv_choose_claim, claim);
 722         batadv_claim_free_ref(claim); /* reference from the hash is gone */
 723
 724         spin_lock_bh(&claim->backbone_gw->crc_lock);
 725         claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 726         spin_unlock_bh(&claim->backbone_gw->crc_lock);
 727
 728         /* don't need the reference from hash_find() anymore */
 729         batadv_claim_free_ref(claim);
 730 }
 731
 732 /**
 733  * batadv_handle_announce - check for ANNOUNCE frame
 734  * @bat_priv: the bat priv with all the soft interface information
 735  * @an_addr: announcement mac address (ARP Sender HW address)
 736  * @backbone_addr: originator address of the sender (Ethernet source MAC)
 737  * @vid: the VLAN ID of the frame
 738  *
 739  * Return: 1 if handled
 740  */
 741 static int batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr,
 742                                   u8 *backbone_addr, unsigned short vid)
 743 {
 744         struct batadv_bla_backbone_gw *backbone_gw;
 745         u16 backbone_crc, crc;
 746
 747         if (memcmp(an_addr, batadv_announce_mac, 4) != 0)
 748                 return 0;
 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         /* handle as ANNOUNCE frame */
 757         backbone_gw->lasttime = jiffies;
 758         crc = ntohs(*((__be16 *)(&an_addr[4])));
 759
 760         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 761                    "handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n",
 762                    BATADV_PRINT_VID(vid), backbone_gw->orig, crc);
 763
 764         spin_lock_bh(&backbone_gw->crc_lock);
 765         backbone_crc = backbone_gw->crc;
 766         spin_unlock_bh(&backbone_gw->crc_lock);
 767
 768         if (backbone_crc != crc) {
 769                 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
 770                            "handle_announce(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n",
 771                            backbone_gw->orig,
 772                            BATADV_PRINT_VID(backbone_gw->vid),
 773                            backbone_crc, crc);
 774
 775                 batadv_bla_send_request(backbone_gw);
 776         } else {
 777                 /* if we have sent a request and the crc was OK,
 778                  * we can allow traffic again.
 779                  */
 780                 if (atomic_read(&backbone_gw->request_sent)) {
 781                         atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
 782                         atomic_set(&backbone_gw->request_sent, 0);
 783                 }
 784         }
 785
 786         batadv_backbone_gw_free_ref(backbone_gw);
 787         return 1;
 788 }
 789
 790 /**
 791  * batadv_handle_request - check for REQUEST frame
 792  * @bat_priv: the bat priv with all the soft interface information
 793  * @primary_if: the primary hard interface of this batman soft interface
 794  * @backbone_addr: backbone address to be requested (ARP sender HW MAC)
 795  * @ethhdr: ethernet header of a packet
 796  * @vid: the VLAN ID of the frame
 797  *
 798  * Return: 1 if handled
 799  */
 800 static int batadv_handle_request(struct batadv_priv *bat_priv,
 801                                  struct batadv_hard_iface *primary_if,
 802                                  u8 *backbone_addr, struct ethhdr *ethhdr,
 803                                  unsigned short vid)
 804 {
 805         /* check for REQUEST frame */
 806         if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest))
 807                 return 0;
 808
 809         /* sanity check, this should not happen on a normal switch,
 810          * we ignore it in this case.
 811          */
 812         if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr))
 813                 return 1;
 814
 815         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 816                    "handle_request(): REQUEST vid %d (sent by %pM)...\n",
 817                    BATADV_PRINT_VID(vid), ethhdr->h_source);
 818
 819         batadv_bla_answer_request(bat_priv, primary_if, vid);
 820         return 1;
 821 }
 822
 823 /**
 824  * batadv_handle_unclaim - check for UNCLAIM frame
 825  * @bat_priv: the bat priv with all the soft interface information
 826  * @primary_if: the primary hard interface of this batman soft interface
 827  * @backbone_addr: originator address of the backbone (Ethernet source)
 828  * @claim_addr: Client to be unclaimed (ARP sender HW MAC)
 829  * @vid: the VLAN ID of the frame
 830  *
 831  * Return: 1 if handled
 832  */
 833 static int batadv_handle_unclaim(struct batadv_priv *bat_priv,
 834                                  struct batadv_hard_iface *primary_if,
 835                                  u8 *backbone_addr, u8 *claim_addr,
 836                                  unsigned short vid)
 837 {
 838         struct batadv_bla_backbone_gw *backbone_gw;
 839
 840         /* unclaim in any case if it is our own */
 841         if (primary_if && batadv_compare_eth(backbone_addr,
 842                                              primary_if->net_dev->dev_addr))
 843                 batadv_bla_send_claim(bat_priv, claim_addr, vid,
 844                                       BATADV_CLAIM_TYPE_UNCLAIM);
 845
 846         backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid);
 847
 848         if (!backbone_gw)
 849                 return 1;
 850
 851         /* this must be an UNCLAIM frame */
 852         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 853                    "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n",
 854                    claim_addr, BATADV_PRINT_VID(vid), backbone_gw->orig);
 855
 856         batadv_bla_del_claim(bat_priv, claim_addr, vid);
 857         batadv_backbone_gw_free_ref(backbone_gw);
 858         return 1;
 859 }
 860
 861 /**
 862  * batadv_handle_claim - check for CLAIM frame
 863  * @bat_priv: the bat priv with all the soft interface information
 864  * @primary_if: the primary hard interface of this batman soft interface
 865  * @backbone_addr: originator address of the backbone (Ethernet Source)
 866  * @claim_addr: client mac address to be claimed (ARP sender HW MAC)
 867  * @vid: the VLAN ID of the frame
 868  *
 869  * Return: 1 if handled
 870  */
 871 static int batadv_handle_claim(struct batadv_priv *bat_priv,
 872                                struct batadv_hard_iface *primary_if,
 873                                u8 *backbone_addr, u8 *claim_addr,
 874                                unsigned short vid)
 875 {
 876         struct batadv_bla_backbone_gw *backbone_gw;
 877
 878         /* register the gateway if not yet available, and add the claim. */
 879
 880         backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
 881                                                  false);
 882
 883         if (unlikely(!backbone_gw))
 884                 return 1;
 885
 886         /* this must be a CLAIM frame */
 887         batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw);
 888         if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
 889                 batadv_bla_send_claim(bat_priv, claim_addr, vid,
 890                                       BATADV_CLAIM_TYPE_CLAIM);
 891
 892         /* TODO: we could call something like tt_local_del() here. */
 893
 894         batadv_backbone_gw_free_ref(backbone_gw);
 895         return 1;
 896 }
 897
 898 /**
 899  * batadv_check_claim_group - check for claim group membership
 900  * @bat_priv: the bat priv with all the soft interface information
 901  * @primary_if: the primary interface of this batman interface
 902  * @hw_src: the Hardware source in the ARP Header
 903  * @hw_dst: the Hardware destination in the ARP Header
 904  * @ethhdr: pointer to the Ethernet header of the claim frame
 905  *
 906  * checks if it is a claim packet and if its on the same group.
 907  * This function also applies the group ID of the sender
 908  * if it is in the same mesh.
 909  *
 910  * Return:
 911  *      2  - if it is a claim packet and on the same group
 912  *      1  - if is a claim packet from another group
 913  *      0  - if it is not a claim packet
 914  */
 915 static int batadv_check_claim_group(struct batadv_priv *bat_priv,
 916                                     struct batadv_hard_iface *primary_if,
 917                                     u8 *hw_src, u8 *hw_dst,
 918                                     struct ethhdr *ethhdr)
 919 {
 920         u8 *backbone_addr;
 921         struct batadv_orig_node *orig_node;
 922         struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
 923
 924         bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
 925         bla_dst_own = &bat_priv->bla.claim_dest;
 926
 927         /* if announcement packet, use the source,
 928          * otherwise assume it is in the hw_src
 929          */
 930         switch (bla_dst->type) {
 931         case BATADV_CLAIM_TYPE_CLAIM:
 932                 backbone_addr = hw_src;
 933                 break;
 934         case BATADV_CLAIM_TYPE_REQUEST:
 935         case BATADV_CLAIM_TYPE_ANNOUNCE:
 936         case BATADV_CLAIM_TYPE_UNCLAIM:
 937                 backbone_addr = ethhdr->h_source;
 938                 break;
 939         default:
 940                 return 0;
 941         }
 942
 943         /* don't accept claim frames from ourselves */
 944         if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
 945                 return 0;
 946
 947         /* if its already the same group, it is fine. */
 948         if (bla_dst->group == bla_dst_own->group)
 949                 return 2;
 950
 951         /* lets see if this originator is in our mesh */
 952         orig_node = batadv_orig_hash_find(bat_priv, backbone_addr);
 953
 954         /* dont accept claims from gateways which are not in
 955          * the same mesh or group.
 956          */
 957         if (!orig_node)
 958                 return 1;
 959
 960         /* if our mesh friends mac is bigger, use it for ourselves. */
 961         if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) {
 962                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 963                            "taking other backbones claim group: %#.4x\n",
 964                            ntohs(bla_dst->group));
 965                 bla_dst_own->group = bla_dst->group;
 966         }
 967
 968         batadv_orig_node_free_ref(orig_node);
 969
 970         return 2;
 971 }
 972
 973 /**
 974  * batadv_bla_process_claim - Check if this is a claim frame, and process it
 975  * @bat_priv: the bat priv with all the soft interface information
 976  * @primary_if: the primary hard interface of this batman soft interface
 977  * @skb: the frame to be checked
 978  *
 979  * Return: 1 if it was a claim frame, otherwise return 0 to
 980  * tell the callee that it can use the frame on its own.
 981  */
 982 static int batadv_bla_process_claim(struct batadv_priv *bat_priv,
 983                                     struct batadv_hard_iface *primary_if,
 984                                     struct sk_buff *skb)
 985 {
 986         struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
 987         u8 *hw_src, *hw_dst;
 988         struct vlan_hdr *vhdr, vhdr_buf;
 989         struct ethhdr *ethhdr;
 990         struct arphdr *arphdr;
 991         unsigned short vid;
 992         int vlan_depth = 0;
 993         __be16 proto;
 994         int headlen;
 995         int ret;
 996
 997         vid = batadv_get_vid(skb, 0);
 998         ethhdr = eth_hdr(skb);
 999
1000         proto = ethhdr->h_proto;
1001         headlen = ETH_HLEN;
1002         if (vid & BATADV_VLAN_HAS_TAG) {
1003                 /* Traverse the VLAN/Ethertypes.
1004                  *
1005                  * At this point it is known that the first protocol is a VLAN
1006                  * header, so start checking at the encapsulated protocol.
1007                  *
1008                  * The depth of the VLAN headers is recorded to drop BLA claim
1009                  * frames encapsulated into multiple VLAN headers (QinQ).
1010                  */
1011                 do {
1012                         vhdr = skb_header_pointer(skb, headlen, VLAN_HLEN,
1013                                                   &vhdr_buf);
1014                         if (!vhdr)
1015                                 return 0;
1016
1017                         proto = vhdr->h_vlan_encapsulated_proto;
1018                         headlen += VLAN_HLEN;
1019                         vlan_depth++;
1020                 } while (proto == htons(ETH_P_8021Q));
1021         }
1022
1023         if (proto != htons(ETH_P_ARP))
1024                 return 0; /* not a claim frame */
1025
1026         /* this must be a ARP frame. check if it is a claim. */
1027
1028         if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
1029                 return 0;
1030
1031         /* pskb_may_pull() may have modified the pointers, get ethhdr again */
1032         ethhdr = eth_hdr(skb);
1033         arphdr = (struct arphdr *)((u8 *)ethhdr + headlen);
1034
1035         /* Check whether the ARP frame carries a valid
1036          * IP information
1037          */
1038         if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
1039                 return 0;
1040         if (arphdr->ar_pro != htons(ETH_P_IP))
1041                 return 0;
1042         if (arphdr->ar_hln != ETH_ALEN)
1043                 return 0;
1044         if (arphdr->ar_pln != 4)
1045                 return 0;
1046
1047         hw_src = (u8 *)arphdr + sizeof(struct arphdr);
1048         hw_dst = hw_src + ETH_ALEN + 4;
1049         bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
1050         bla_dst_own = &bat_priv->bla.claim_dest;
1051
1052         /* check if it is a claim frame in general */
1053         if (memcmp(bla_dst->magic, bla_dst_own->magic,
1054                    sizeof(bla_dst->magic)) != 0)
1055                 return 0;
1056
1057         /* check if there is a claim frame encapsulated deeper in (QinQ) and
1058          * drop that, as this is not supported by BLA but should also not be
1059          * sent via the mesh.
1060          */
1061         if (vlan_depth > 1)
1062                 return 1;
1063
1064         /* check if it is a claim frame. */
1065         ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
1066                                        ethhdr);
1067         if (ret == 1)
1068                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1069                            "bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
1070                            ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src,
1071                            hw_dst);
1072
1073         if (ret < 2)
1074                 return ret;
1075
1076         /* become a backbone gw ourselves on this vlan if not happened yet */
1077         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1078
1079         /* check for the different types of claim frames ... */
1080         switch (bla_dst->type) {
1081         case BATADV_CLAIM_TYPE_CLAIM:
1082                 if (batadv_handle_claim(bat_priv, primary_if, hw_src,
1083                                         ethhdr->h_source, vid))
1084                         return 1;
1085                 break;
1086         case BATADV_CLAIM_TYPE_UNCLAIM:
1087                 if (batadv_handle_unclaim(bat_priv, primary_if,
1088                                           ethhdr->h_source, hw_src, vid))
1089                         return 1;
1090                 break;
1091
1092         case BATADV_CLAIM_TYPE_ANNOUNCE:
1093                 if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
1094                                            vid))
1095                         return 1;
1096                 break;
1097         case BATADV_CLAIM_TYPE_REQUEST:
1098                 if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
1099                                           vid))
1100                         return 1;
1101                 break;
1102         }
1103
1104         batadv_dbg(BATADV_DBG_BLA, bat_priv,
1105                    "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",
1106                    ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src, hw_dst);
1107         return 1;
1108 }
1109
1110 /**
1111  * batadv_bla_purge_backbone_gw - Remove backbone gateways after a timeout or
1112  *  immediately
1113  * @bat_priv: the bat priv with all the soft interface information
1114  * @now: whether the whole hash shall be wiped now
1115  *
1116  * Check when we last heard from other nodes, and remove them in case of
1117  * a time out, or clean all backbone gws if now is set.
1118  */
1119 static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now)
1120 {
1121         struct batadv_bla_backbone_gw *backbone_gw;
1122         struct hlist_node *node_tmp;
1123         struct hlist_head *head;
1124         struct batadv_hashtable *hash;
1125         spinlock_t *list_lock;  /* protects write access to the hash lists */
1126         int i;
1127
1128         hash = bat_priv->bla.backbone_hash;
1129         if (!hash)
1130                 return;
1131
1132         for (i = 0; i < hash->size; i++) {
1133                 head = &hash->table[i];
1134                 list_lock = &hash->list_locks[i];
1135
1136                 spin_lock_bh(list_lock);
1137                 hlist_for_each_entry_safe(backbone_gw, node_tmp,
1138                                           head, hash_entry) {
1139                         if (now)
1140                                 goto purge_now;
1141                         if (!batadv_has_timed_out(backbone_gw->lasttime,
1142                                                   BATADV_BLA_BACKBONE_TIMEOUT))
1143                                 continue;
1144
1145                         batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
1146                                    "bla_purge_backbone_gw(): backbone gw %pM timed out\n",
1147                                    backbone_gw->orig);
1148
1149 purge_now:
1150                         /* don't wait for the pending request anymore */
1151                         if (atomic_read(&backbone_gw->request_sent))
1152                                 atomic_dec(&bat_priv->bla.num_requests);
1153
1154                         batadv_bla_del_backbone_claims(backbone_gw);
1155
1156                         hlist_del_rcu(&backbone_gw->hash_entry);
1157                         batadv_backbone_gw_free_ref(backbone_gw);
1158                 }
1159                 spin_unlock_bh(list_lock);
1160         }
1161 }
1162
1163 /**
1164  * batadv_bla_purge_claims - Remove claims after a timeout or immediately
1165  * @bat_priv: the bat priv with all the soft interface information
1166  * @primary_if: the selected primary interface, may be NULL if now is set
1167  * @now: whether the whole hash shall be wiped now
1168  *
1169  * Check when we heard last time from our own claims, and remove them in case of
1170  * a time out, or clean all claims if now is set
1171  */
1172 static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
1173                                     struct batadv_hard_iface *primary_if,
1174                                     int now)
1175 {
1176         struct batadv_bla_claim *claim;
1177         struct hlist_head *head;
1178         struct batadv_hashtable *hash;
1179         int i;
1180
1181         hash = bat_priv->bla.claim_hash;
1182         if (!hash)
1183                 return;
1184
1185         for (i = 0; i < hash->size; i++) {
1186                 head = &hash->table[i];
1187
1188                 rcu_read_lock();
1189                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
1190                         if (now)
1191                                 goto purge_now;
1192                         if (!batadv_compare_eth(claim->backbone_gw->orig,
1193                                                 primary_if->net_dev->dev_addr))
1194                                 continue;
1195                         if (!batadv_has_timed_out(claim->lasttime,
1196                                                   BATADV_BLA_CLAIM_TIMEOUT))
1197                                 continue;
1198
1199                         batadv_dbg(BATADV_DBG_BLA, bat_priv,
1200                                    "bla_purge_claims(): %pM, vid %d, time out\n",
1201                                    claim->addr, claim->vid);
1202
1203 purge_now:
1204                         batadv_handle_unclaim(bat_priv, primary_if,
1205                                               claim->backbone_gw->orig,
1206                                               claim->addr, claim->vid);
1207                 }
1208                 rcu_read_unlock();
1209         }
1210 }
1211
1212 /**
1213  * batadv_bla_update_orig_address - Update the backbone gateways when the own
1214  *  originator address changes
1215  * @bat_priv: the bat priv with all the soft interface information
1216  * @primary_if: the new selected primary_if
1217  * @oldif: the old primary interface, may be NULL
1218  */
1219 void batadv_bla_update_orig_address(struct batadv_priv *bat_priv,
1220                                     struct batadv_hard_iface *primary_if,
1221                                     struct batadv_hard_iface *oldif)
1222 {
1223         struct batadv_bla_backbone_gw *backbone_gw;
1224         struct hlist_head *head;
1225         struct batadv_hashtable *hash;
1226         __be16 group;
1227         int i;
1228
1229         /* reset bridge loop avoidance group id */
1230         group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN));
1231         bat_priv->bla.claim_dest.group = group;
1232
1233         /* purge everything when bridge loop avoidance is turned off */
1234         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1235                 oldif = NULL;
1236
1237         if (!oldif) {
1238                 batadv_bla_purge_claims(bat_priv, NULL, 1);
1239                 batadv_bla_purge_backbone_gw(bat_priv, 1);
1240                 return;
1241         }
1242
1243         hash = bat_priv->bla.backbone_hash;
1244         if (!hash)
1245                 return;
1246
1247         for (i = 0; i < hash->size; i++) {
1248                 head = &hash->table[i];
1249
1250                 rcu_read_lock();
1251                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1252                         /* own orig still holds the old value. */
1253                         if (!batadv_compare_eth(backbone_gw->orig,
1254                                                 oldif->net_dev->dev_addr))
1255                                 continue;
1256
1257                         ether_addr_copy(backbone_gw->orig,
1258                                         primary_if->net_dev->dev_addr);
1259                         /* send an announce frame so others will ask for our
1260                          * claims and update their tables.
1261                          */
1262                         batadv_bla_send_announce(bat_priv, backbone_gw);
1263                 }
1264                 rcu_read_unlock();
1265         }
1266 }
1267
1268 /**
1269  * batadv_bla_status_update - purge bla interfaces if necessary
1270  * @net_dev: the soft interface net device
1271  */
1272 void batadv_bla_status_update(struct net_device *net_dev)
1273 {
1274         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1275         struct batadv_hard_iface *primary_if;
1276
1277         primary_if = batadv_primary_if_get_selected(bat_priv);
1278         if (!primary_if)
1279                 return;
1280
1281         /* this function already purges everything when bla is disabled,
1282          * so just call that one.
1283          */
1284         batadv_bla_update_orig_address(bat_priv, primary_if, primary_if);
1285         batadv_hardif_free_ref(primary_if);
1286 }
1287
1288 /**
1289  * batadv_bla_periodic_work - performs periodic bla work
1290  * @work: kernel work struct
1291  *
1292  * periodic work to do:
1293  *  * purge structures when they are too old
1294  *  * send announcements
1295  */
1296 static void batadv_bla_periodic_work(struct work_struct *work)
1297 {
1298         struct delayed_work *delayed_work;
1299         struct batadv_priv *bat_priv;
1300         struct batadv_priv_bla *priv_bla;
1301         struct hlist_head *head;
1302         struct batadv_bla_backbone_gw *backbone_gw;
1303         struct batadv_hashtable *hash;
1304         struct batadv_hard_iface *primary_if;
1305         int i;
1306
1307         delayed_work = container_of(work, struct delayed_work, work);
1308         priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
1309         bat_priv = container_of(priv_bla, struct batadv_priv, bla);
1310         primary_if = batadv_primary_if_get_selected(bat_priv);
1311         if (!primary_if)
1312                 goto out;
1313
1314         batadv_bla_purge_claims(bat_priv, primary_if, 0);
1315         batadv_bla_purge_backbone_gw(bat_priv, 0);
1316
1317         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1318                 goto out;
1319
1320         hash = bat_priv->bla.backbone_hash;
1321         if (!hash)
1322                 goto out;
1323
1324         for (i = 0; i < hash->size; i++) {
1325                 head = &hash->table[i];
1326
1327                 rcu_read_lock();
1328                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1329                         if (!batadv_compare_eth(backbone_gw->orig,
1330                                                 primary_if->net_dev->dev_addr))
1331                                 continue;
1332
1333                         backbone_gw->lasttime = jiffies;
1334
1335                         batadv_bla_send_announce(bat_priv, backbone_gw);
1336
1337                         /* request_sent is only set after creation to avoid
1338                          * problems when we are not yet known as backbone gw
1339                          * in the backbone.
1340                          *
1341                          * We can reset this now after we waited some periods
1342                          * to give bridge forward delays and bla group forming
1343                          * some grace time.
1344                          */
1345
1346                         if (atomic_read(&backbone_gw->request_sent) == 0)
1347                                 continue;
1348
1349                         if (!atomic_dec_and_test(&backbone_gw->wait_periods))
1350                                 continue;
1351
1352                         atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
1353                         atomic_set(&backbone_gw->request_sent, 0);
1354                 }
1355                 rcu_read_unlock();
1356         }
1357 out:
1358         if (primary_if)
1359                 batadv_hardif_free_ref(primary_if);
1360
1361         queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1362                            msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1363 }
1364
1365 /* The hash for claim and backbone hash receive the same key because they
1366  * are getting initialized by hash_new with the same key. Reinitializing
1367  * them with to different keys to allow nested locking without generating
1368  * lockdep warnings
1369  */
1370 static struct lock_class_key batadv_claim_hash_lock_class_key;
1371 static struct lock_class_key batadv_backbone_hash_lock_class_key;
1372
1373 /**
1374  * batadv_bla_init - initialize all bla structures
1375  * @bat_priv: the bat priv with all the soft interface information
1376  *
1377  * Return: 0 on success, < 0 on error.
1378  */
1379 int batadv_bla_init(struct batadv_priv *bat_priv)
1380 {
1381         int i;
1382         u8 claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
1383         struct batadv_hard_iface *primary_if;
1384         u16 crc;
1385         unsigned long entrytime;
1386
1387         spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
1388
1389         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
1390
1391         /* setting claim destination address */
1392         memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3);
1393         bat_priv->bla.claim_dest.type = 0;
1394         primary_if = batadv_primary_if_get_selected(bat_priv);
1395         if (primary_if) {
1396                 crc = crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN);
1397                 bat_priv->bla.claim_dest.group = htons(crc);
1398                 batadv_hardif_free_ref(primary_if);
1399         } else {
1400                 bat_priv->bla.claim_dest.group = 0; /* will be set later */
1401         }
1402
1403         /* initialize the duplicate list */
1404         entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT);
1405         for (i = 0; i < BATADV_DUPLIST_SIZE; i++)
1406                 bat_priv->bla.bcast_duplist[i].entrytime = entrytime;
1407         bat_priv->bla.bcast_duplist_curr = 0;
1408
1409         if (bat_priv->bla.claim_hash)
1410                 return 0;
1411
1412         bat_priv->bla.claim_hash = batadv_hash_new(128);
1413         bat_priv->bla.backbone_hash = batadv_hash_new(32);
1414
1415         if (!bat_priv->bla.claim_hash || !bat_priv->bla.backbone_hash)
1416                 return -ENOMEM;
1417
1418         batadv_hash_set_lock_class(bat_priv->bla.claim_hash,
1419                                    &batadv_claim_hash_lock_class_key);
1420         batadv_hash_set_lock_class(bat_priv->bla.backbone_hash,
1421                                    &batadv_backbone_hash_lock_class_key);
1422
1423         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n");
1424
1425         INIT_DELAYED_WORK(&bat_priv->bla.work, batadv_bla_periodic_work);
1426
1427         queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1428                            msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1429         return 0;
1430 }
1431
1432 /**
1433  * batadv_bla_check_bcast_duplist - Check if a frame is in the broadcast dup.
1434  * @bat_priv: the bat priv with all the soft interface information
1435  * @skb: contains the bcast_packet to be checked
1436  *
1437  * check if it is on our broadcast list. Another gateway might
1438  * have sent the same packet because it is connected to the same backbone,
1439  * so we have to remove this duplicate.
1440  *
1441  * This is performed by checking the CRC, which will tell us
1442  * with a good chance that it is the same packet. If it is furthermore
1443  * sent by another host, drop it. We allow equal packets from
1444  * the same host however as this might be intended.
1445  *
1446  * Return: 1 if a packet is in the duplicate list, 0 otherwise.
1447  */
1448 int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
1449                                    struct sk_buff *skb)
1450 {
1451         int i, curr, ret = 0;
1452         __be32 crc;
1453         struct batadv_bcast_packet *bcast_packet;
1454         struct batadv_bcast_duplist_entry *entry;
1455
1456         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1457
1458         /* calculate the crc ... */
1459         crc = batadv_skb_crc32(skb, (u8 *)(bcast_packet + 1));
1460
1461         spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
1462
1463         for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
1464                 curr = (bat_priv->bla.bcast_duplist_curr + i);
1465                 curr %= BATADV_DUPLIST_SIZE;
1466                 entry = &bat_priv->bla.bcast_duplist[curr];
1467
1468                 /* we can stop searching if the entry is too old ;
1469                  * later entries will be even older
1470                  */
1471                 if (batadv_has_timed_out(entry->entrytime,
1472                                          BATADV_DUPLIST_TIMEOUT))
1473                         break;
1474
1475                 if (entry->crc != crc)
1476                         continue;
1477
1478                 if (batadv_compare_eth(entry->orig, bcast_packet->orig))
1479                         continue;
1480
1481                 /* this entry seems to match: same crc, not too old,
1482                  * and from another gw. therefore return 1 to forbid it.
1483                  */
1484                 ret = 1;
1485                 goto out;
1486         }
1487         /* not found, add a new entry (overwrite the oldest entry)
1488          * and allow it, its the first occurrence.
1489          */
1490         curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
1491         curr %= BATADV_DUPLIST_SIZE;
1492         entry = &bat_priv->bla.bcast_duplist[curr];
1493         entry->crc = crc;
1494         entry->entrytime = jiffies;
1495         ether_addr_copy(entry->orig, bcast_packet->orig);
1496         bat_priv->bla.bcast_duplist_curr = curr;
1497
1498 out:
1499         spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
1500
1501         return ret;
1502 }
1503
1504 /**
1505  * batadv_bla_is_backbone_gw_orig - Check if the originator is a gateway for
1506  *  the VLAN identified by vid.
1507  * @bat_priv: the bat priv with all the soft interface information
1508  * @orig: originator mac address
1509  * @vid: VLAN identifier
1510  *
1511  * Return: true if orig is a backbone for this vid, false otherwise.
1512  */
1513 bool batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, u8 *orig,
1514                                     unsigned short vid)
1515 {
1516         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1517         struct hlist_head *head;
1518         struct batadv_bla_backbone_gw *backbone_gw;
1519         int i;
1520
1521         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1522                 return false;
1523
1524         if (!hash)
1525                 return false;
1526
1527         for (i = 0; i < hash->size; i++) {
1528                 head = &hash->table[i];
1529
1530                 rcu_read_lock();
1531                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1532                         if (batadv_compare_eth(backbone_gw->orig, orig) &&
1533                             backbone_gw->vid == vid) {
1534                                 rcu_read_unlock();
1535                                 return true;
1536                         }
1537                 }
1538                 rcu_read_unlock();
1539         }
1540
1541         return false;
1542 }
1543
1544 /**
1545  * batadv_bla_is_backbone_gw - check if originator is a backbone gw for a VLAN.
1546  * @skb: the frame to be checked
1547  * @orig_node: the orig_node of the frame
1548  * @hdr_size: maximum length of the frame
1549  *
1550  * Return: 1 if the orig_node is also a gateway on the soft interface, otherwise
1551  * it returns 0.
1552  */
1553 int batadv_bla_is_backbone_gw(struct sk_buff *skb,
1554                               struct batadv_orig_node *orig_node, int hdr_size)
1555 {
1556         struct batadv_bla_backbone_gw *backbone_gw;
1557         unsigned short vid;
1558
1559         if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
1560                 return 0;
1561
1562         /* first, find out the vid. */
1563         if (!pskb_may_pull(skb, hdr_size + ETH_HLEN))
1564                 return 0;
1565
1566         vid = batadv_get_vid(skb, hdr_size);
1567
1568         /* see if this originator is a backbone gw for this VLAN */
1569         backbone_gw = batadv_backbone_hash_find(orig_node->bat_priv,
1570                                                 orig_node->orig, vid);
1571         if (!backbone_gw)
1572                 return 0;
1573
1574         batadv_backbone_gw_free_ref(backbone_gw);
1575         return 1;
1576 }
1577
1578 /**
1579  * batadv_bla_init - free all bla structures
1580  * @bat_priv: the bat priv with all the soft interface information
1581  *
1582  * for softinterface free or module unload
1583  */
1584 void batadv_bla_free(struct batadv_priv *bat_priv)
1585 {
1586         struct batadv_hard_iface *primary_if;
1587
1588         cancel_delayed_work_sync(&bat_priv->bla.work);
1589         primary_if = batadv_primary_if_get_selected(bat_priv);
1590
1591         if (bat_priv->bla.claim_hash) {
1592                 batadv_bla_purge_claims(bat_priv, primary_if, 1);
1593                 batadv_hash_destroy(bat_priv->bla.claim_hash);
1594                 bat_priv->bla.claim_hash = NULL;
1595         }
1596         if (bat_priv->bla.backbone_hash) {
1597                 batadv_bla_purge_backbone_gw(bat_priv, 1);
1598                 batadv_hash_destroy(bat_priv->bla.backbone_hash);
1599                 bat_priv->bla.backbone_hash = NULL;
1600         }
1601         if (primary_if)
1602                 batadv_hardif_free_ref(primary_if);
1603 }
1604
1605 /**
1606  * batadv_bla_rx - check packets coming from the mesh.
1607  * @bat_priv: the bat priv with all the soft interface information
1608  * @skb: the frame to be checked
1609  * @vid: the VLAN ID of the frame
1610  * @is_bcast: the packet came in a broadcast packet type.
1611  *
1612  * batadv_bla_rx avoidance checks if:
1613  *  * we have to race for a claim
1614  *  * if the frame is allowed on the LAN
1615  *
1616  * in these cases, the skb is further handled by this function
1617  *
1618  * Return: 1 if handled, otherwise it returns 0 and the caller shall further
1619  * process the skb.
1620  */
1621 int batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1622                   unsigned short vid, bool is_bcast)
1623 {
1624         struct ethhdr *ethhdr;
1625         struct batadv_bla_claim search_claim, *claim = NULL;
1626         struct batadv_hard_iface *primary_if;
1627         int ret;
1628
1629         ethhdr = eth_hdr(skb);
1630
1631         primary_if = batadv_primary_if_get_selected(bat_priv);
1632         if (!primary_if)
1633                 goto handled;
1634
1635         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1636                 goto allow;
1637
1638         if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1639                 /* don't allow broadcasts while requests are in flight */
1640                 if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast)
1641                         goto handled;
1642
1643         ether_addr_copy(search_claim.addr, ethhdr->h_source);
1644         search_claim.vid = vid;
1645         claim = batadv_claim_hash_find(bat_priv, &search_claim);
1646
1647         if (!claim) {
1648                 /* possible optimization: race for a claim */
1649                 /* No claim exists yet, claim it for us!
1650                  */
1651                 batadv_handle_claim(bat_priv, primary_if,
1652                                     primary_if->net_dev->dev_addr,
1653                                     ethhdr->h_source, vid);
1654                 goto allow;
1655         }
1656
1657         /* if it is our own claim ... */
1658         if (batadv_compare_eth(claim->backbone_gw->orig,
1659                                primary_if->net_dev->dev_addr)) {
1660                 /* ... allow it in any case */
1661                 claim->lasttime = jiffies;
1662                 goto allow;
1663         }
1664
1665         /* if it is a broadcast ... */
1666         if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) {
1667                 /* ... drop it. the responsible gateway is in charge.
1668                  *
1669                  * We need to check is_bcast because with the gateway
1670                  * feature, broadcasts (like DHCP requests) may be sent
1671                  * using a unicast packet type.
1672                  */
1673                 goto handled;
1674         } else {
1675                 /* seems the client considers us as its best gateway.
1676                  * send a claim and update the claim table
1677                  * immediately.
1678                  */
1679                 batadv_handle_claim(bat_priv, primary_if,
1680                                     primary_if->net_dev->dev_addr,
1681                                     ethhdr->h_source, vid);
1682                 goto allow;
1683         }
1684 allow:
1685         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1686         ret = 0;
1687         goto out;
1688
1689 handled:
1690         kfree_skb(skb);
1691         ret = 1;
1692
1693 out:
1694         if (primary_if)
1695                 batadv_hardif_free_ref(primary_if);
1696         if (claim)
1697                 batadv_claim_free_ref(claim);
1698         return ret;
1699 }
1700
1701 /**
1702  * batadv_bla_tx - check packets going into the mesh
1703  * @bat_priv: the bat priv with all the soft interface information
1704  * @skb: the frame to be checked
1705  * @vid: the VLAN ID of the frame
1706  *
1707  * batadv_bla_tx checks if:
1708  *  * a claim was received which has to be processed
1709  *  * the frame is allowed on the mesh
1710  *
1711  * in these cases, the skb is further handled by this function.
1712  *
1713  * This call might reallocate skb data.
1714  *
1715  * Return: 1 if handled, otherwise it returns 0 and the caller shall further
1716  * process the skb.
1717  */
1718 int batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1719                   unsigned short vid)
1720 {
1721         struct ethhdr *ethhdr;
1722         struct batadv_bla_claim search_claim, *claim = NULL;
1723         struct batadv_hard_iface *primary_if;
1724         int ret = 0;
1725
1726         primary_if = batadv_primary_if_get_selected(bat_priv);
1727         if (!primary_if)
1728                 goto out;
1729
1730         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1731                 goto allow;
1732
1733         if (batadv_bla_process_claim(bat_priv, primary_if, skb))
1734                 goto handled;
1735
1736         ethhdr = eth_hdr(skb);
1737
1738         if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1739                 /* don't allow broadcasts while requests are in flight */
1740                 if (is_multicast_ether_addr(ethhdr->h_dest))
1741                         goto handled;
1742
1743         ether_addr_copy(search_claim.addr, ethhdr->h_source);
1744         search_claim.vid = vid;
1745
1746         claim = batadv_claim_hash_find(bat_priv, &search_claim);
1747
1748         /* if no claim exists, allow it. */
1749         if (!claim)
1750                 goto allow;
1751
1752         /* check if we are responsible. */
1753         if (batadv_compare_eth(claim->backbone_gw->orig,
1754                                primary_if->net_dev->dev_addr)) {
1755                 /* if yes, the client has roamed and we have
1756                  * to unclaim it.
1757                  */
1758                 batadv_handle_unclaim(bat_priv, primary_if,
1759                                       primary_if->net_dev->dev_addr,
1760                                       ethhdr->h_source, vid);
1761                 goto allow;
1762         }
1763
1764         /* check if it is a multicast/broadcast frame */
1765         if (is_multicast_ether_addr(ethhdr->h_dest)) {
1766                 /* drop it. the responsible gateway has forwarded it into
1767                  * the backbone network.
1768                  */
1769                 goto handled;
1770         } else {
1771                 /* we must allow it. at least if we are
1772                  * responsible for the DESTINATION.
1773                  */
1774                 goto allow;
1775         }
1776 allow:
1777         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1778         ret = 0;
1779         goto out;
1780 handled:
1781         ret = 1;
1782 out:
1783         if (primary_if)
1784                 batadv_hardif_free_ref(primary_if);
1785         if (claim)
1786                 batadv_claim_free_ref(claim);
1787         return ret;
1788 }
1789
1790 /**
1791  * batadv_bla_claim_table_seq_print_text - print the claim table in a seq file
1792  * @seq: seq file to print on
1793  * @offset: not used
1794  *
1795  * Return: always 0
1796  */
1797 int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset)
1798 {
1799         struct net_device *net_dev = (struct net_device *)seq->private;
1800         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1801         struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
1802         struct batadv_bla_claim *claim;
1803         struct batadv_hard_iface *primary_if;
1804         struct hlist_head *head;
1805         u16 backbone_crc;
1806         u32 i;
1807         bool is_own;
1808         u8 *primary_addr;
1809
1810         primary_if = batadv_seq_print_text_primary_if_get(seq);
1811         if (!primary_if)
1812                 goto out;
1813
1814         primary_addr = primary_if->net_dev->dev_addr;
1815         seq_printf(seq,
1816                    "Claims announced for the mesh %s (orig %pM, group id %#.4x)\n",
1817                    net_dev->name, primary_addr,
1818                    ntohs(bat_priv->bla.claim_dest.group));
1819         seq_printf(seq, "   %-17s    %-5s    %-17s [o] (%-6s)\n",
1820                    "Client", "VID", "Originator", "CRC");
1821         for (i = 0; i < hash->size; i++) {
1822                 head = &hash->table[i];
1823
1824                 rcu_read_lock();
1825                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
1826                         is_own = batadv_compare_eth(claim->backbone_gw->orig,
1827                                                     primary_addr);
1828
1829                         spin_lock_bh(&claim->backbone_gw->crc_lock);
1830                         backbone_crc = claim->backbone_gw->crc;
1831                         spin_unlock_bh(&claim->backbone_gw->crc_lock);
1832                         seq_printf(seq, " * %pM on %5d by %pM [%c] (%#.4x)\n",
1833                                    claim->addr, BATADV_PRINT_VID(claim->vid),
1834                                    claim->backbone_gw->orig,
1835                                    (is_own ? 'x' : ' '),
1836                                    backbone_crc);
1837                 }
1838                 rcu_read_unlock();
1839         }
1840 out:
1841         if (primary_if)
1842                 batadv_hardif_free_ref(primary_if);
1843         return 0;
1844 }
1845
1846 /**
1847  * batadv_bla_backbone_table_seq_print_text - print the backbone table in a seq
1848  *  file
1849  * @seq: seq file to print on
1850  * @offset: not used
1851  *
1852  * Return: always 0
1853  */
1854 int batadv_bla_backbone_table_seq_print_text(struct seq_file *seq, void *offset)
1855 {
1856         struct net_device *net_dev = (struct net_device *)seq->private;
1857         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1858         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1859         struct batadv_bla_backbone_gw *backbone_gw;
1860         struct batadv_hard_iface *primary_if;
1861         struct hlist_head *head;
1862         int secs, msecs;
1863         u16 backbone_crc;
1864         u32 i;
1865         bool is_own;
1866         u8 *primary_addr;
1867
1868         primary_if = batadv_seq_print_text_primary_if_get(seq);
1869         if (!primary_if)
1870                 goto out;
1871
1872         primary_addr = primary_if->net_dev->dev_addr;
1873         seq_printf(seq,
1874                    "Backbones announced for the mesh %s (orig %pM, group id %#.4x)\n",
1875                    net_dev->name, primary_addr,
1876                    ntohs(bat_priv->bla.claim_dest.group));
1877         seq_printf(seq, "   %-17s    %-5s %-9s (%-6s)\n",
1878                    "Originator", "VID", "last seen", "CRC");
1879         for (i = 0; i < hash->size; i++) {
1880                 head = &hash->table[i];
1881
1882                 rcu_read_lock();
1883                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1884                         msecs = jiffies_to_msecs(jiffies -
1885                                                  backbone_gw->lasttime);
1886                         secs = msecs / 1000;
1887                         msecs = msecs % 1000;
1888
1889                         is_own = batadv_compare_eth(backbone_gw->orig,
1890                                                     primary_addr);
1891                         if (is_own)
1892                                 continue;
1893
1894                         spin_lock_bh(&backbone_gw->crc_lock);
1895                         backbone_crc = backbone_gw->crc;
1896                         spin_unlock_bh(&backbone_gw->crc_lock);
1897
1898                         seq_printf(seq, " * %pM on %5d %4i.%03is (%#.4x)\n",
1899                                    backbone_gw->orig,
1900                                    BATADV_PRINT_VID(backbone_gw->vid), secs,
1901                                    msecs, backbone_crc);
1902                 }
1903                 rcu_read_unlock();
1904         }
1905 out:
1906         if (primary_if)
1907                 batadv_hardif_free_ref(primary_if);
1908         return 0;
1909 }