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 "sysfs.h"
  54 #include "translation-table.h"
  55
  56 static const u8 batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
  57
  58 static void batadv_bla_periodic_work(struct work_struct *work);
  59 static void
  60 batadv_bla_send_announce(struct batadv_priv *bat_priv,
  61                          struct batadv_bla_backbone_gw *backbone_gw);
  62
  63 /**
  64  * batadv_choose_claim - choose the right bucket for a claim.
  65  * @data: data to hash
  66  * @size: size of the hash table
  67  *
  68  * Return: the hash index of the claim
  69  */
  70 static inline u32 batadv_choose_claim(const void *data, u32 size)
  71 {
  72         struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
  73         u32 hash = 0;
  74
  75         hash = jhash(&claim->addr, sizeof(claim->addr), hash);
  76         hash = jhash(&claim->vid, sizeof(claim->vid), hash);
  77
  78         return hash % size;
  79 }
  80
  81 /**
  82  * batadv_choose_backbone_gw - choose the right bucket for a backbone gateway.
  83  * @data: data to hash
  84  * @size: size of the hash table
  85  *
  86  * Return: the hash index of the backbone gateway
  87  */
  88 static inline u32 batadv_choose_backbone_gw(const void *data, u32 size)
  89 {
  90         const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
  91         u32 hash = 0;
  92
  93         hash = jhash(&claim->addr, sizeof(claim->addr), hash);
  94         hash = jhash(&claim->vid, sizeof(claim->vid), hash);
  95
  96         return hash % size;
  97 }
  98
  99 /**
 100  * batadv_compare_backbone_gw - compare address and vid of two backbone gws
 101  * @node: list node of the first entry to compare
 102  * @data2: pointer to the second backbone gateway
 103  *
 104  * Return: true if the backbones have the same data, false otherwise
 105  */
 106 static bool batadv_compare_backbone_gw(const struct hlist_node *node,
 107                                        const void *data2)
 108 {
 109         const void *data1 = container_of(node, struct batadv_bla_backbone_gw,
 110                                          hash_entry);
 111         const struct batadv_bla_backbone_gw *gw1 = data1;
 112         const struct batadv_bla_backbone_gw *gw2 = data2;
 113
 114         if (!batadv_compare_eth(gw1->orig, gw2->orig))
 115                 return false;
 116
 117         if (gw1->vid != gw2->vid)
 118                 return false;
 119
 120         return true;
 121 }
 122
 123 /**
 124  * batadv_compare_claim - compare address and vid of two claims
 125  * @node: list node of the first entry to compare
 126  * @data2: pointer to the second claims
 127  *
 128  * Return: true if the claim have the same data, 0 otherwise
 129  */
 130 static bool batadv_compare_claim(const struct hlist_node *node,
 131                                  const void *data2)
 132 {
 133         const void *data1 = container_of(node, struct batadv_bla_claim,
 134                                          hash_entry);
 135         const struct batadv_bla_claim *cl1 = data1;
 136         const struct batadv_bla_claim *cl2 = data2;
 137
 138         if (!batadv_compare_eth(cl1->addr, cl2->addr))
 139                 return false;
 140
 141         if (cl1->vid != cl2->vid)
 142                 return false;
 143
 144         return true;
 145 }
 146
 147 /**
 148  * batadv_backbone_gw_release - release backbone gw from lists and queue for
 149  *  free after rcu grace period
 150  * @ref: kref pointer of the backbone gw
 151  */
 152 static void batadv_backbone_gw_release(struct kref *ref)
 153 {
 154         struct batadv_bla_backbone_gw *backbone_gw;
 155
 156         backbone_gw = container_of(ref, struct batadv_bla_backbone_gw,
 157                                    refcount);
 158
 159         kfree_rcu(backbone_gw, rcu);
 160 }
 161
 162 /**
 163  * batadv_backbone_gw_put - decrement the backbone gw refcounter and possibly
 164  *  release it
 165  * @backbone_gw: backbone gateway to be free'd
 166  */
 167 static void batadv_backbone_gw_put(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_put(claim->backbone_gw);
 184         kfree_rcu(claim, rcu);
 185 }
 186
 187 /**
 188  * batadv_claim_put - decrement the claim refcounter and possibly
 189  *  release it
 190  * @claim: claim to be free'd
 191  */
 192 static void batadv_claim_put(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_put(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         case BATADV_CLAIM_TYPE_LOOPDETECT:
 412                 ether_addr_copy(ethhdr->h_source, mac);
 413                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 414                            "bla_send_claim(): LOOPDETECT of %pM to %pM on vid %d\n",
 415                            ethhdr->h_source, ethhdr->h_dest,
 416                            BATADV_PRINT_VID(vid));
 417
 418                 break;
 419         }
 420
 421         if (vid & BATADV_VLAN_HAS_TAG)
 422                 skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
 423                                       vid & VLAN_VID_MASK);
 424
 425         skb_reset_mac_header(skb);
 426         skb->protocol = eth_type_trans(skb, soft_iface);
 427         batadv_inc_counter(bat_priv, BATADV_CNT_RX);
 428         batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
 429                            skb->len + ETH_HLEN);
 430         soft_iface->last_rx = jiffies;
 431
 432         netif_rx(skb);
 433 out:
 434         if (primary_if)
 435                 batadv_hardif_put(primary_if);
 436 }
 437
 438 /**
 439  * batadv_bla_loopdetect_report - worker for reporting the loop
 440  * @work: work queue item
 441  *
 442  * Throws an uevent, as the loopdetect check function can't do that itself
 443  * since the kernel may sleep while throwing uevents.
 444  */
 445 static void batadv_bla_loopdetect_report(struct work_struct *work)
 446 {
 447         struct batadv_bla_backbone_gw *backbone_gw;
 448         struct batadv_priv *bat_priv;
 449         char vid_str[6] = { '\0' };
 450
 451         backbone_gw = container_of(work, struct batadv_bla_backbone_gw,
 452                                    report_work);
 453         bat_priv = backbone_gw->bat_priv;
 454
 455         batadv_info(bat_priv->soft_iface,
 456                     "Possible loop on VLAN %d detected which can't be handled by BLA - please check your network setup!\n",
 457                     BATADV_PRINT_VID(backbone_gw->vid));
 458         snprintf(vid_str, sizeof(vid_str), "%d",
 459                  BATADV_PRINT_VID(backbone_gw->vid));
 460         vid_str[sizeof(vid_str) - 1] = 0;
 461
 462         batadv_throw_uevent(bat_priv, BATADV_UEV_BLA, BATADV_UEV_LOOPDETECT,
 463                             vid_str);
 464
 465         batadv_backbone_gw_put(backbone_gw);
 466 }
 467
 468 /**
 469  * batadv_bla_get_backbone_gw - finds or creates a backbone gateway
 470  * @bat_priv: the bat priv with all the soft interface information
 471  * @orig: the mac address of the originator
 472  * @vid: the VLAN ID
 473  * @own_backbone: set if the requested backbone is local
 474  *
 475  * Return: the (possibly created) backbone gateway or NULL on error
 476  */
 477 static struct batadv_bla_backbone_gw *
 478 batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *orig,
 479                            unsigned short vid, bool own_backbone)
 480 {
 481         struct batadv_bla_backbone_gw *entry;
 482         struct batadv_orig_node *orig_node;
 483         int hash_added;
 484
 485         entry = batadv_backbone_hash_find(bat_priv, orig, vid);
 486
 487         if (entry)
 488                 return entry;
 489
 490         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 491                    "bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n",
 492                    orig, BATADV_PRINT_VID(vid));
 493
 494         entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
 495         if (!entry)
 496                 return NULL;
 497
 498         entry->vid = vid;
 499         entry->lasttime = jiffies;
 500         entry->crc = BATADV_BLA_CRC_INIT;
 501         entry->bat_priv = bat_priv;
 502         spin_lock_init(&entry->crc_lock);
 503         atomic_set(&entry->request_sent, 0);
 504         atomic_set(&entry->wait_periods, 0);
 505         ether_addr_copy(entry->orig, orig);
 506         INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report);
 507
 508         /* one for the hash, one for returning */
 509         kref_init(&entry->refcount);
 510         kref_get(&entry->refcount);
 511
 512         hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
 513                                      batadv_compare_backbone_gw,
 514                                      batadv_choose_backbone_gw, entry,
 515                                      &entry->hash_entry);
 516
 517         if (unlikely(hash_added != 0)) {
 518                 /* hash failed, free the structure */
 519                 kfree(entry);
 520                 return NULL;
 521         }
 522
 523         /* this is a gateway now, remove any TT entry on this VLAN */
 524         orig_node = batadv_orig_hash_find(bat_priv, orig);
 525         if (orig_node) {
 526                 batadv_tt_global_del_orig(bat_priv, orig_node, vid,
 527                                           "became a backbone gateway");
 528                 batadv_orig_node_put(orig_node);
 529         }
 530
 531         if (own_backbone) {
 532                 batadv_bla_send_announce(bat_priv, entry);
 533
 534                 /* this will be decreased in the worker thread */
 535                 atomic_inc(&entry->request_sent);
 536                 atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
 537                 atomic_inc(&bat_priv->bla.num_requests);
 538         }
 539
 540         return entry;
 541 }
 542
 543 /**
 544  * batadv_bla_update_own_backbone_gw - updates the own backbone gw for a VLAN
 545  * @bat_priv: the bat priv with all the soft interface information
 546  * @primary_if: the selected primary interface
 547  * @vid: VLAN identifier
 548  *
 549  * update or add the own backbone gw to make sure we announce
 550  * where we receive other backbone gws
 551  */
 552 static void
 553 batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv,
 554                                   struct batadv_hard_iface *primary_if,
 555                                   unsigned short vid)
 556 {
 557         struct batadv_bla_backbone_gw *backbone_gw;
 558
 559         backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
 560                                                  primary_if->net_dev->dev_addr,
 561                                                  vid, true);
 562         if (unlikely(!backbone_gw))
 563                 return;
 564
 565         backbone_gw->lasttime = jiffies;
 566         batadv_backbone_gw_put(backbone_gw);
 567 }
 568
 569 /**
 570  * batadv_bla_answer_request - answer a bla request by sending own claims
 571  * @bat_priv: the bat priv with all the soft interface information
 572  * @primary_if: interface where the request came on
 573  * @vid: the vid where the request came on
 574  *
 575  * Repeat all of our own claims, and finally send an ANNOUNCE frame
 576  * to allow the requester another check if the CRC is correct now.
 577  */
 578 static void batadv_bla_answer_request(struct batadv_priv *bat_priv,
 579                                       struct batadv_hard_iface *primary_if,
 580                                       unsigned short vid)
 581 {
 582         struct hlist_head *head;
 583         struct batadv_hashtable *hash;
 584         struct batadv_bla_claim *claim;
 585         struct batadv_bla_backbone_gw *backbone_gw;
 586         int i;
 587
 588         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 589                    "bla_answer_request(): received a claim request, send all of our own claims again\n");
 590
 591         backbone_gw = batadv_backbone_hash_find(bat_priv,
 592                                                 primary_if->net_dev->dev_addr,
 593                                                 vid);
 594         if (!backbone_gw)
 595                 return;
 596
 597         hash = bat_priv->bla.claim_hash;
 598         for (i = 0; i < hash->size; i++) {
 599                 head = &hash->table[i];
 600
 601                 rcu_read_lock();
 602                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
 603                         /* only own claims are interesting */
 604                         if (claim->backbone_gw != backbone_gw)
 605                                 continue;
 606
 607                         batadv_bla_send_claim(bat_priv, claim->addr, claim->vid,
 608                                               BATADV_CLAIM_TYPE_CLAIM);
 609                 }
 610                 rcu_read_unlock();
 611         }
 612
 613         /* finally, send an announcement frame */
 614         batadv_bla_send_announce(bat_priv, backbone_gw);
 615         batadv_backbone_gw_put(backbone_gw);
 616 }
 617
 618 /**
 619  * batadv_bla_send_request - send a request to repeat claims
 620  * @backbone_gw: the backbone gateway from whom we are out of sync
 621  *
 622  * When the crc is wrong, ask the backbone gateway for a full table update.
 623  * After the request, it will repeat all of his own claims and finally
 624  * send an announcement claim with which we can check again.
 625  */
 626 static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw)
 627 {
 628         /* first, remove all old entries */
 629         batadv_bla_del_backbone_claims(backbone_gw);
 630
 631         batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
 632                    "Sending REQUEST to %pM\n", backbone_gw->orig);
 633
 634         /* send request */
 635         batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig,
 636                               backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST);
 637
 638         /* no local broadcasts should be sent or received, for now. */
 639         if (!atomic_read(&backbone_gw->request_sent)) {
 640                 atomic_inc(&backbone_gw->bat_priv->bla.num_requests);
 641                 atomic_set(&backbone_gw->request_sent, 1);
 642         }
 643 }
 644
 645 /**
 646  * batadv_bla_send_announce - Send an announcement frame
 647  * @bat_priv: the bat priv with all the soft interface information
 648  * @backbone_gw: our backbone gateway which should be announced
 649  */
 650 static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
 651                                      struct batadv_bla_backbone_gw *backbone_gw)
 652 {
 653         u8 mac[ETH_ALEN];
 654         __be16 crc;
 655
 656         memcpy(mac, batadv_announce_mac, 4);
 657         spin_lock_bh(&backbone_gw->crc_lock);
 658         crc = htons(backbone_gw->crc);
 659         spin_unlock_bh(&backbone_gw->crc_lock);
 660         memcpy(&mac[4], &crc, 2);
 661
 662         batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid,
 663                               BATADV_CLAIM_TYPE_ANNOUNCE);
 664 }
 665
 666 /**
 667  * batadv_bla_add_claim - Adds a claim in the claim hash
 668  * @bat_priv: the bat priv with all the soft interface information
 669  * @mac: the mac address of the claim
 670  * @vid: the VLAN ID of the frame
 671  * @backbone_gw: the backbone gateway which claims it
 672  */
 673 static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 674                                  const u8 *mac, const unsigned short vid,
 675                                  struct batadv_bla_backbone_gw *backbone_gw)
 676 {
 677         struct batadv_bla_claim *claim;
 678         struct batadv_bla_claim search_claim;
 679         int hash_added;
 680
 681         ether_addr_copy(search_claim.addr, mac);
 682         search_claim.vid = vid;
 683         claim = batadv_claim_hash_find(bat_priv, &search_claim);
 684
 685         /* create a new claim entry if it does not exist yet. */
 686         if (!claim) {
 687                 claim = kzalloc(sizeof(*claim), GFP_ATOMIC);
 688                 if (!claim)
 689                         return;
 690
 691                 ether_addr_copy(claim->addr, mac);
 692                 claim->vid = vid;
 693                 claim->lasttime = jiffies;
 694                 claim->backbone_gw = backbone_gw;
 695
 696                 kref_init(&claim->refcount);
 697                 kref_get(&claim->refcount);
 698                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 699                            "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n",
 700                            mac, BATADV_PRINT_VID(vid));
 701                 hash_added = batadv_hash_add(bat_priv->bla.claim_hash,
 702                                              batadv_compare_claim,
 703                                              batadv_choose_claim, claim,
 704                                              &claim->hash_entry);
 705
 706                 if (unlikely(hash_added != 0)) {
 707                         /* only local changes happened. */
 708                         kfree(claim);
 709                         return;
 710                 }
 711         } else {
 712                 claim->lasttime = jiffies;
 713                 if (claim->backbone_gw == backbone_gw)
 714                         /* no need to register a new backbone */
 715                         goto claim_free_ref;
 716
 717                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
 718                            "bla_add_claim(): changing ownership for %pM, vid %d\n",
 719                            mac, BATADV_PRINT_VID(vid));
 720
 721                 spin_lock_bh(&claim->backbone_gw->crc_lock);
 722                 claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 723                 spin_unlock_bh(&claim->backbone_gw->crc_lock);
 724                 batadv_backbone_gw_put(claim->backbone_gw);
 725         }
 726         /* set (new) backbone gw */
 727         kref_get(&backbone_gw->refcount);
 728         claim->backbone_gw = backbone_gw;
 729
 730         spin_lock_bh(&backbone_gw->crc_lock);
 731         backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 732         spin_unlock_bh(&backbone_gw->crc_lock);
 733         backbone_gw->lasttime = jiffies;
 734
 735 claim_free_ref:
 736         batadv_claim_put(claim);
 737 }
 738
 739 /**
 740  * batadv_bla_del_claim - delete a claim from the claim hash
 741  * @bat_priv: the bat priv with all the soft interface information
 742  * @mac: mac address of the claim to be removed
 743  * @vid: VLAN id for the claim to be removed
 744  */
 745 static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
 746                                  const u8 *mac, const unsigned short vid)
 747 {
 748         struct batadv_bla_claim search_claim, *claim;
 749
 750         ether_addr_copy(search_claim.addr, mac);
 751         search_claim.vid = vid;
 752         claim = batadv_claim_hash_find(bat_priv, &search_claim);
 753         if (!claim)
 754                 return;
 755
 756         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n",
 757                    mac, BATADV_PRINT_VID(vid));
 758
 759         batadv_hash_remove(bat_priv->bla.claim_hash, batadv_compare_claim,
 760                            batadv_choose_claim, claim);
 761         batadv_claim_put(claim); /* reference from the hash is gone */
 762
 763         spin_lock_bh(&claim->backbone_gw->crc_lock);
 764         claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
 765         spin_unlock_bh(&claim->backbone_gw->crc_lock);
 766
 767         /* don't need the reference from hash_find() anymore */
 768         batadv_claim_put(claim);
 769 }
 770
 771 /**
 772  * batadv_handle_announce - check for ANNOUNCE frame
 773  * @bat_priv: the bat priv with all the soft interface information
 774  * @an_addr: announcement mac address (ARP Sender HW address)
 775  * @backbone_addr: originator address of the sender (Ethernet source MAC)
 776  * @vid: the VLAN ID of the frame
 777  *
 778  * Return: true if handled
 779  */
 780 static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr,
 781                                    u8 *backbone_addr, unsigned short vid)
 782 {
 783         struct batadv_bla_backbone_gw *backbone_gw;
 784         u16 backbone_crc, crc;
 785
 786         if (memcmp(an_addr, batadv_announce_mac, 4) != 0)
 787                 return false;
 788
 789         backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
 790                                                  false);
 791
 792         if (unlikely(!backbone_gw))
 793                 return true;
 794
 795         /* handle as ANNOUNCE frame */
 796         backbone_gw->lasttime = jiffies;
 797         crc = ntohs(*((__be16 *)(&an_addr[4])));
 798
 799         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 800                    "handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n",
 801                    BATADV_PRINT_VID(vid), backbone_gw->orig, crc);
 802
 803         spin_lock_bh(&backbone_gw->crc_lock);
 804         backbone_crc = backbone_gw->crc;
 805         spin_unlock_bh(&backbone_gw->crc_lock);
 806
 807         if (backbone_crc != crc) {
 808                 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
 809                            "handle_announce(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n",
 810                            backbone_gw->orig,
 811                            BATADV_PRINT_VID(backbone_gw->vid),
 812                            backbone_crc, crc);
 813
 814                 batadv_bla_send_request(backbone_gw);
 815         } else {
 816                 /* if we have sent a request and the crc was OK,
 817                  * we can allow traffic again.
 818                  */
 819                 if (atomic_read(&backbone_gw->request_sent)) {
 820                         atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
 821                         atomic_set(&backbone_gw->request_sent, 0);
 822                 }
 823         }
 824
 825         batadv_backbone_gw_put(backbone_gw);
 826         return true;
 827 }
 828
 829 /**
 830  * batadv_handle_request - check for REQUEST frame
 831  * @bat_priv: the bat priv with all the soft interface information
 832  * @primary_if: the primary hard interface of this batman soft interface
 833  * @backbone_addr: backbone address to be requested (ARP sender HW MAC)
 834  * @ethhdr: ethernet header of a packet
 835  * @vid: the VLAN ID of the frame
 836  *
 837  * Return: true if handled
 838  */
 839 static bool batadv_handle_request(struct batadv_priv *bat_priv,
 840                                   struct batadv_hard_iface *primary_if,
 841                                   u8 *backbone_addr, struct ethhdr *ethhdr,
 842                                   unsigned short vid)
 843 {
 844         /* check for REQUEST frame */
 845         if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest))
 846                 return false;
 847
 848         /* sanity check, this should not happen on a normal switch,
 849          * we ignore it in this case.
 850          */
 851         if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr))
 852                 return true;
 853
 854         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 855                    "handle_request(): REQUEST vid %d (sent by %pM)...\n",
 856                    BATADV_PRINT_VID(vid), ethhdr->h_source);
 857
 858         batadv_bla_answer_request(bat_priv, primary_if, vid);
 859         return true;
 860 }
 861
 862 /**
 863  * batadv_handle_unclaim - check for UNCLAIM frame
 864  * @bat_priv: the bat priv with all the soft interface information
 865  * @primary_if: the primary hard interface of this batman soft interface
 866  * @backbone_addr: originator address of the backbone (Ethernet source)
 867  * @claim_addr: Client to be unclaimed (ARP sender HW MAC)
 868  * @vid: the VLAN ID of the frame
 869  *
 870  * Return: true if handled
 871  */
 872 static bool batadv_handle_unclaim(struct batadv_priv *bat_priv,
 873                                   struct batadv_hard_iface *primary_if,
 874                                   u8 *backbone_addr, u8 *claim_addr,
 875                                   unsigned short vid)
 876 {
 877         struct batadv_bla_backbone_gw *backbone_gw;
 878
 879         /* unclaim in any case if it is our own */
 880         if (primary_if && batadv_compare_eth(backbone_addr,
 881                                              primary_if->net_dev->dev_addr))
 882                 batadv_bla_send_claim(bat_priv, claim_addr, vid,
 883                                       BATADV_CLAIM_TYPE_UNCLAIM);
 884
 885         backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid);
 886
 887         if (!backbone_gw)
 888                 return true;
 889
 890         /* this must be an UNCLAIM frame */
 891         batadv_dbg(BATADV_DBG_BLA, bat_priv,
 892                    "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n",
 893                    claim_addr, BATADV_PRINT_VID(vid), backbone_gw->orig);
 894
 895         batadv_bla_del_claim(bat_priv, claim_addr, vid);
 896         batadv_backbone_gw_put(backbone_gw);
 897         return true;
 898 }
 899
 900 /**
 901  * batadv_handle_claim - check for CLAIM frame
 902  * @bat_priv: the bat priv with all the soft interface information
 903  * @primary_if: the primary hard interface of this batman soft interface
 904  * @backbone_addr: originator address of the backbone (Ethernet Source)
 905  * @claim_addr: client mac address to be claimed (ARP sender HW MAC)
 906  * @vid: the VLAN ID of the frame
 907  *
 908  * Return: true if handled
 909  */
 910 static bool batadv_handle_claim(struct batadv_priv *bat_priv,
 911                                 struct batadv_hard_iface *primary_if,
 912                                 u8 *backbone_addr, u8 *claim_addr,
 913                                 unsigned short vid)
 914 {
 915         struct batadv_bla_backbone_gw *backbone_gw;
 916
 917         /* register the gateway if not yet available, and add the claim. */
 918
 919         backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
 920                                                  false);
 921
 922         if (unlikely(!backbone_gw))
 923                 return true;
 924
 925         /* this must be a CLAIM frame */
 926         batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw);
 927         if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
 928                 batadv_bla_send_claim(bat_priv, claim_addr, vid,
 929                                       BATADV_CLAIM_TYPE_CLAIM);
 930
 931         /* TODO: we could call something like tt_local_del() here. */
 932
 933         batadv_backbone_gw_put(backbone_gw);
 934         return true;
 935 }
 936
 937 /**
 938  * batadv_check_claim_group - check for claim group membership
 939  * @bat_priv: the bat priv with all the soft interface information
 940  * @primary_if: the primary interface of this batman interface
 941  * @hw_src: the Hardware source in the ARP Header
 942  * @hw_dst: the Hardware destination in the ARP Header
 943  * @ethhdr: pointer to the Ethernet header of the claim frame
 944  *
 945  * checks if it is a claim packet and if its on the same group.
 946  * This function also applies the group ID of the sender
 947  * if it is in the same mesh.
 948  *
 949  * Return:
 950  *      2  - if it is a claim packet and on the same group
 951  *      1  - if is a claim packet from another group
 952  *      0  - if it is not a claim packet
 953  */
 954 static int batadv_check_claim_group(struct batadv_priv *bat_priv,
 955                                     struct batadv_hard_iface *primary_if,
 956                                     u8 *hw_src, u8 *hw_dst,
 957                                     struct ethhdr *ethhdr)
 958 {
 959         u8 *backbone_addr;
 960         struct batadv_orig_node *orig_node;
 961         struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
 962
 963         bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
 964         bla_dst_own = &bat_priv->bla.claim_dest;
 965
 966         /* if announcement packet, use the source,
 967          * otherwise assume it is in the hw_src
 968          */
 969         switch (bla_dst->type) {
 970         case BATADV_CLAIM_TYPE_CLAIM:
 971                 backbone_addr = hw_src;
 972                 break;
 973         case BATADV_CLAIM_TYPE_REQUEST:
 974         case BATADV_CLAIM_TYPE_ANNOUNCE:
 975         case BATADV_CLAIM_TYPE_UNCLAIM:
 976                 backbone_addr = ethhdr->h_source;
 977                 break;
 978         default:
 979                 return 0;
 980         }
 981
 982         /* don't accept claim frames from ourselves */
 983         if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
 984                 return 0;
 985
 986         /* if its already the same group, it is fine. */
 987         if (bla_dst->group == bla_dst_own->group)
 988                 return 2;
 989
 990         /* lets see if this originator is in our mesh */
 991         orig_node = batadv_orig_hash_find(bat_priv, backbone_addr);
 992
 993         /* dont accept claims from gateways which are not in
 994          * the same mesh or group.
 995          */
 996         if (!orig_node)
 997                 return 1;
 998
 999         /* if our mesh friends mac is bigger, use it for ourselves. */
1000         if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) {
1001                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1002                            "taking other backbones claim group: %#.4x\n",
1003                            ntohs(bla_dst->group));
1004                 bla_dst_own->group = bla_dst->group;
1005         }
1006
1007         batadv_orig_node_put(orig_node);
1008
1009         return 2;
1010 }
1011
1012 /**
1013  * batadv_bla_process_claim - Check if this is a claim frame, and process it
1014  * @bat_priv: the bat priv with all the soft interface information
1015  * @primary_if: the primary hard interface of this batman soft interface
1016  * @skb: the frame to be checked
1017  *
1018  * Return: true if it was a claim frame, otherwise return false to
1019  * tell the callee that it can use the frame on its own.
1020  */
1021 static bool batadv_bla_process_claim(struct batadv_priv *bat_priv,
1022                                      struct batadv_hard_iface *primary_if,
1023                                      struct sk_buff *skb)
1024 {
1025         struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
1026         u8 *hw_src, *hw_dst;
1027         struct vlan_hdr *vhdr, vhdr_buf;
1028         struct ethhdr *ethhdr;
1029         struct arphdr *arphdr;
1030         unsigned short vid;
1031         int vlan_depth = 0;
1032         __be16 proto;
1033         int headlen;
1034         int ret;
1035
1036         vid = batadv_get_vid(skb, 0);
1037         ethhdr = eth_hdr(skb);
1038
1039         proto = ethhdr->h_proto;
1040         headlen = ETH_HLEN;
1041         if (vid & BATADV_VLAN_HAS_TAG) {
1042                 /* Traverse the VLAN/Ethertypes.
1043                  *
1044                  * At this point it is known that the first protocol is a VLAN
1045                  * header, so start checking at the encapsulated protocol.
1046                  *
1047                  * The depth of the VLAN headers is recorded to drop BLA claim
1048                  * frames encapsulated into multiple VLAN headers (QinQ).
1049                  */
1050                 do {
1051                         vhdr = skb_header_pointer(skb, headlen, VLAN_HLEN,
1052                                                   &vhdr_buf);
1053                         if (!vhdr)
1054                                 return false;
1055
1056                         proto = vhdr->h_vlan_encapsulated_proto;
1057                         headlen += VLAN_HLEN;
1058                         vlan_depth++;
1059                 } while (proto == htons(ETH_P_8021Q));
1060         }
1061
1062         if (proto != htons(ETH_P_ARP))
1063                 return false; /* not a claim frame */
1064
1065         /* this must be a ARP frame. check if it is a claim. */
1066
1067         if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
1068                 return false;
1069
1070         /* pskb_may_pull() may have modified the pointers, get ethhdr again */
1071         ethhdr = eth_hdr(skb);
1072         arphdr = (struct arphdr *)((u8 *)ethhdr + headlen);
1073
1074         /* Check whether the ARP frame carries a valid
1075          * IP information
1076          */
1077         if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
1078                 return false;
1079         if (arphdr->ar_pro != htons(ETH_P_IP))
1080                 return false;
1081         if (arphdr->ar_hln != ETH_ALEN)
1082                 return false;
1083         if (arphdr->ar_pln != 4)
1084                 return false;
1085
1086         hw_src = (u8 *)arphdr + sizeof(struct arphdr);
1087         hw_dst = hw_src + ETH_ALEN + 4;
1088         bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
1089         bla_dst_own = &bat_priv->bla.claim_dest;
1090
1091         /* check if it is a claim frame in general */
1092         if (memcmp(bla_dst->magic, bla_dst_own->magic,
1093                    sizeof(bla_dst->magic)) != 0)
1094                 return false;
1095
1096         /* check if there is a claim frame encapsulated deeper in (QinQ) and
1097          * drop that, as this is not supported by BLA but should also not be
1098          * sent via the mesh.
1099          */
1100         if (vlan_depth > 1)
1101                 return true;
1102
1103         /* Let the loopdetect frames on the mesh in any case. */
1104         if (bla_dst->type == BATADV_CLAIM_TYPE_LOOPDETECT)
1105                 return 0;
1106
1107         /* check if it is a claim frame. */
1108         ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
1109                                        ethhdr);
1110         if (ret == 1)
1111                 batadv_dbg(BATADV_DBG_BLA, bat_priv,
1112                            "bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
1113                            ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src,
1114                            hw_dst);
1115
1116         if (ret < 2)
1117                 return !!ret;
1118
1119         /* become a backbone gw ourselves on this vlan if not happened yet */
1120         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1121
1122         /* check for the different types of claim frames ... */
1123         switch (bla_dst->type) {
1124         case BATADV_CLAIM_TYPE_CLAIM:
1125                 if (batadv_handle_claim(bat_priv, primary_if, hw_src,
1126                                         ethhdr->h_source, vid))
1127                         return true;
1128                 break;
1129         case BATADV_CLAIM_TYPE_UNCLAIM:
1130                 if (batadv_handle_unclaim(bat_priv, primary_if,
1131                                           ethhdr->h_source, hw_src, vid))
1132                         return true;
1133                 break;
1134
1135         case BATADV_CLAIM_TYPE_ANNOUNCE:
1136                 if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
1137                                            vid))
1138                         return true;
1139                 break;
1140         case BATADV_CLAIM_TYPE_REQUEST:
1141                 if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
1142                                           vid))
1143                         return true;
1144                 break;
1145         }
1146
1147         batadv_dbg(BATADV_DBG_BLA, bat_priv,
1148                    "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",
1149                    ethhdr->h_source, BATADV_PRINT_VID(vid), hw_src, hw_dst);
1150         return true;
1151 }
1152
1153 /**
1154  * batadv_bla_purge_backbone_gw - Remove backbone gateways after a timeout or
1155  *  immediately
1156  * @bat_priv: the bat priv with all the soft interface information
1157  * @now: whether the whole hash shall be wiped now
1158  *
1159  * Check when we last heard from other nodes, and remove them in case of
1160  * a time out, or clean all backbone gws if now is set.
1161  */
1162 static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now)
1163 {
1164         struct batadv_bla_backbone_gw *backbone_gw;
1165         struct hlist_node *node_tmp;
1166         struct hlist_head *head;
1167         struct batadv_hashtable *hash;
1168         spinlock_t *list_lock;  /* protects write access to the hash lists */
1169         int i;
1170
1171         hash = bat_priv->bla.backbone_hash;
1172         if (!hash)
1173                 return;
1174
1175         for (i = 0; i < hash->size; i++) {
1176                 head = &hash->table[i];
1177                 list_lock = &hash->list_locks[i];
1178
1179                 spin_lock_bh(list_lock);
1180                 hlist_for_each_entry_safe(backbone_gw, node_tmp,
1181                                           head, hash_entry) {
1182                         if (now)
1183                                 goto purge_now;
1184                         if (!batadv_has_timed_out(backbone_gw->lasttime,
1185                                                   BATADV_BLA_BACKBONE_TIMEOUT))
1186                                 continue;
1187
1188                         batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
1189                                    "bla_purge_backbone_gw(): backbone gw %pM timed out\n",
1190                                    backbone_gw->orig);
1191
1192 purge_now:
1193                         /* don't wait for the pending request anymore */
1194                         if (atomic_read(&backbone_gw->request_sent))
1195                                 atomic_dec(&bat_priv->bla.num_requests);
1196
1197                         batadv_bla_del_backbone_claims(backbone_gw);
1198
1199                         hlist_del_rcu(&backbone_gw->hash_entry);
1200                         batadv_backbone_gw_put(backbone_gw);
1201                 }
1202                 spin_unlock_bh(list_lock);
1203         }
1204 }
1205
1206 /**
1207  * batadv_bla_purge_claims - Remove claims after a timeout or immediately
1208  * @bat_priv: the bat priv with all the soft interface information
1209  * @primary_if: the selected primary interface, may be NULL if now is set
1210  * @now: whether the whole hash shall be wiped now
1211  *
1212  * Check when we heard last time from our own claims, and remove them in case of
1213  * a time out, or clean all claims if now is set
1214  */
1215 static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
1216                                     struct batadv_hard_iface *primary_if,
1217                                     int now)
1218 {
1219         struct batadv_bla_claim *claim;
1220         struct hlist_head *head;
1221         struct batadv_hashtable *hash;
1222         int i;
1223
1224         hash = bat_priv->bla.claim_hash;
1225         if (!hash)
1226                 return;
1227
1228         for (i = 0; i < hash->size; i++) {
1229                 head = &hash->table[i];
1230
1231                 rcu_read_lock();
1232                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
1233                         if (now)
1234                                 goto purge_now;
1235                         if (!batadv_compare_eth(claim->backbone_gw->orig,
1236                                                 primary_if->net_dev->dev_addr))
1237                                 continue;
1238                         if (!batadv_has_timed_out(claim->lasttime,
1239                                                   BATADV_BLA_CLAIM_TIMEOUT))
1240                                 continue;
1241
1242                         batadv_dbg(BATADV_DBG_BLA, bat_priv,
1243                                    "bla_purge_claims(): %pM, vid %d, time out\n",
1244                                    claim->addr, claim->vid);
1245
1246 purge_now:
1247                         batadv_handle_unclaim(bat_priv, primary_if,
1248                                               claim->backbone_gw->orig,
1249                                               claim->addr, claim->vid);
1250                 }
1251                 rcu_read_unlock();
1252         }
1253 }
1254
1255 /**
1256  * batadv_bla_update_orig_address - Update the backbone gateways when the own
1257  *  originator address changes
1258  * @bat_priv: the bat priv with all the soft interface information
1259  * @primary_if: the new selected primary_if
1260  * @oldif: the old primary interface, may be NULL
1261  */
1262 void batadv_bla_update_orig_address(struct batadv_priv *bat_priv,
1263                                     struct batadv_hard_iface *primary_if,
1264                                     struct batadv_hard_iface *oldif)
1265 {
1266         struct batadv_bla_backbone_gw *backbone_gw;
1267         struct hlist_head *head;
1268         struct batadv_hashtable *hash;
1269         __be16 group;
1270         int i;
1271
1272         /* reset bridge loop avoidance group id */
1273         group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN));
1274         bat_priv->bla.claim_dest.group = group;
1275
1276         /* purge everything when bridge loop avoidance is turned off */
1277         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1278                 oldif = NULL;
1279
1280         if (!oldif) {
1281                 batadv_bla_purge_claims(bat_priv, NULL, 1);
1282                 batadv_bla_purge_backbone_gw(bat_priv, 1);
1283                 return;
1284         }
1285
1286         hash = bat_priv->bla.backbone_hash;
1287         if (!hash)
1288                 return;
1289
1290         for (i = 0; i < hash->size; i++) {
1291                 head = &hash->table[i];
1292
1293                 rcu_read_lock();
1294                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1295                         /* own orig still holds the old value. */
1296                         if (!batadv_compare_eth(backbone_gw->orig,
1297                                                 oldif->net_dev->dev_addr))
1298                                 continue;
1299
1300                         ether_addr_copy(backbone_gw->orig,
1301                                         primary_if->net_dev->dev_addr);
1302                         /* send an announce frame so others will ask for our
1303                          * claims and update their tables.
1304                          */
1305                         batadv_bla_send_announce(bat_priv, backbone_gw);
1306                 }
1307                 rcu_read_unlock();
1308         }
1309 }
1310
1311 /**
1312  * batadv_bla_send_loopdetect - send a loopdetect frame
1313  * @bat_priv: the bat priv with all the soft interface information
1314  * @backbone_gw: the backbone gateway for which a loop should be detected
1315  *
1316  * To detect loops that the bridge loop avoidance can't handle, send a loop
1317  * detection packet on the backbone. Unlike other BLA frames, this frame will
1318  * be allowed on the mesh by other nodes. If it is received on the mesh, this
1319  * indicates that there is a loop.
1320  */
1321 static void
1322 batadv_bla_send_loopdetect(struct batadv_priv *bat_priv,
1323                            struct batadv_bla_backbone_gw *backbone_gw)
1324 {
1325         batadv_dbg(BATADV_DBG_BLA, bat_priv, "Send loopdetect frame for vid %d\n",
1326                    backbone_gw->vid);
1327         batadv_bla_send_claim(bat_priv, bat_priv->bla.loopdetect_addr,
1328                               backbone_gw->vid, BATADV_CLAIM_TYPE_LOOPDETECT);
1329 }
1330
1331 /**
1332  * batadv_bla_status_update - purge bla interfaces if necessary
1333  * @net_dev: the soft interface net device
1334  */
1335 void batadv_bla_status_update(struct net_device *net_dev)
1336 {
1337         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1338         struct batadv_hard_iface *primary_if;
1339
1340         primary_if = batadv_primary_if_get_selected(bat_priv);
1341         if (!primary_if)
1342                 return;
1343
1344         /* this function already purges everything when bla is disabled,
1345          * so just call that one.
1346          */
1347         batadv_bla_update_orig_address(bat_priv, primary_if, primary_if);
1348         batadv_hardif_put(primary_if);
1349 }
1350
1351 /**
1352  * batadv_bla_periodic_work - performs periodic bla work
1353  * @work: kernel work struct
1354  *
1355  * periodic work to do:
1356  *  * purge structures when they are too old
1357  *  * send announcements
1358  */
1359 static void batadv_bla_periodic_work(struct work_struct *work)
1360 {
1361         struct delayed_work *delayed_work;
1362         struct batadv_priv *bat_priv;
1363         struct batadv_priv_bla *priv_bla;
1364         struct hlist_head *head;
1365         struct batadv_bla_backbone_gw *backbone_gw;
1366         struct batadv_hashtable *hash;
1367         struct batadv_hard_iface *primary_if;
1368         bool send_loopdetect = false;
1369         int i;
1370
1371         delayed_work = to_delayed_work(work);
1372         priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
1373         bat_priv = container_of(priv_bla, struct batadv_priv, bla);
1374         primary_if = batadv_primary_if_get_selected(bat_priv);
1375         if (!primary_if)
1376                 goto out;
1377
1378         batadv_bla_purge_claims(bat_priv, primary_if, 0);
1379         batadv_bla_purge_backbone_gw(bat_priv, 0);
1380
1381         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1382                 goto out;
1383
1384         if (atomic_dec_and_test(&bat_priv->bla.loopdetect_next)) {
1385                 /* set a new random mac address for the next bridge loop
1386                  * detection frames. Set the locally administered bit to avoid
1387                  * collisions with users mac addresses.
1388                  */
1389                 random_ether_addr(bat_priv->bla.loopdetect_addr);
1390                 bat_priv->bla.loopdetect_addr[0] = 0xba;
1391                 bat_priv->bla.loopdetect_addr[1] = 0xbe;
1392                 bat_priv->bla.loopdetect_lasttime = jiffies;
1393                 atomic_set(&bat_priv->bla.loopdetect_next,
1394                            BATADV_BLA_LOOPDETECT_PERIODS);
1395
1396                 /* mark for sending loop detect on all VLANs */
1397                 send_loopdetect = true;
1398         }
1399
1400         hash = bat_priv->bla.backbone_hash;
1401         if (!hash)
1402                 goto out;
1403
1404         for (i = 0; i < hash->size; i++) {
1405                 head = &hash->table[i];
1406
1407                 rcu_read_lock();
1408                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1409                         if (!batadv_compare_eth(backbone_gw->orig,
1410                                                 primary_if->net_dev->dev_addr))
1411                                 continue;
1412
1413                         backbone_gw->lasttime = jiffies;
1414
1415                         batadv_bla_send_announce(bat_priv, backbone_gw);
1416                         if (send_loopdetect)
1417                                 batadv_bla_send_loopdetect(bat_priv,
1418                                                            backbone_gw);
1419
1420                         /* request_sent is only set after creation to avoid
1421                          * problems when we are not yet known as backbone gw
1422                          * in the backbone.
1423                          *
1424                          * We can reset this now after we waited some periods
1425                          * to give bridge forward delays and bla group forming
1426                          * some grace time.
1427                          */
1428
1429                         if (atomic_read(&backbone_gw->request_sent) == 0)
1430                                 continue;
1431
1432                         if (!atomic_dec_and_test(&backbone_gw->wait_periods))
1433                                 continue;
1434
1435                         atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
1436                         atomic_set(&backbone_gw->request_sent, 0);
1437                 }
1438                 rcu_read_unlock();
1439         }
1440 out:
1441         if (primary_if)
1442                 batadv_hardif_put(primary_if);
1443
1444         queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1445                            msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1446 }
1447
1448 /* The hash for claim and backbone hash receive the same key because they
1449  * are getting initialized by hash_new with the same key. Reinitializing
1450  * them with to different keys to allow nested locking without generating
1451  * lockdep warnings
1452  */
1453 static struct lock_class_key batadv_claim_hash_lock_class_key;
1454 static struct lock_class_key batadv_backbone_hash_lock_class_key;
1455
1456 /**
1457  * batadv_bla_init - initialize all bla structures
1458  * @bat_priv: the bat priv with all the soft interface information
1459  *
1460  * Return: 0 on success, < 0 on error.
1461  */
1462 int batadv_bla_init(struct batadv_priv *bat_priv)
1463 {
1464         int i;
1465         u8 claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
1466         struct batadv_hard_iface *primary_if;
1467         u16 crc;
1468         unsigned long entrytime;
1469
1470         spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
1471
1472         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
1473
1474         /* setting claim destination address */
1475         memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3);
1476         bat_priv->bla.claim_dest.type = 0;
1477         primary_if = batadv_primary_if_get_selected(bat_priv);
1478         if (primary_if) {
1479                 crc = crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN);
1480                 bat_priv->bla.claim_dest.group = htons(crc);
1481                 batadv_hardif_put(primary_if);
1482         } else {
1483                 bat_priv->bla.claim_dest.group = 0; /* will be set later */
1484         }
1485
1486         /* initialize the duplicate list */
1487         entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT);
1488         for (i = 0; i < BATADV_DUPLIST_SIZE; i++)
1489                 bat_priv->bla.bcast_duplist[i].entrytime = entrytime;
1490         bat_priv->bla.bcast_duplist_curr = 0;
1491
1492         atomic_set(&bat_priv->bla.loopdetect_next,
1493                    BATADV_BLA_LOOPDETECT_PERIODS);
1494
1495         if (bat_priv->bla.claim_hash)
1496                 return 0;
1497
1498         bat_priv->bla.claim_hash = batadv_hash_new(128);
1499         bat_priv->bla.backbone_hash = batadv_hash_new(32);
1500
1501         if (!bat_priv->bla.claim_hash || !bat_priv->bla.backbone_hash)
1502                 return -ENOMEM;
1503
1504         batadv_hash_set_lock_class(bat_priv->bla.claim_hash,
1505                                    &batadv_claim_hash_lock_class_key);
1506         batadv_hash_set_lock_class(bat_priv->bla.backbone_hash,
1507                                    &batadv_backbone_hash_lock_class_key);
1508
1509         batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n");
1510
1511         INIT_DELAYED_WORK(&bat_priv->bla.work, batadv_bla_periodic_work);
1512
1513         queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1514                            msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1515         return 0;
1516 }
1517
1518 /**
1519  * batadv_bla_check_bcast_duplist - Check if a frame is in the broadcast dup.
1520  * @bat_priv: the bat priv with all the soft interface information
1521  * @skb: contains the bcast_packet to be checked
1522  *
1523  * check if it is on our broadcast list. Another gateway might
1524  * have sent the same packet because it is connected to the same backbone,
1525  * so we have to remove this duplicate.
1526  *
1527  * This is performed by checking the CRC, which will tell us
1528  * with a good chance that it is the same packet. If it is furthermore
1529  * sent by another host, drop it. We allow equal packets from
1530  * the same host however as this might be intended.
1531  *
1532  * Return: true if a packet is in the duplicate list, false otherwise.
1533  */
1534 bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
1535                                     struct sk_buff *skb)
1536 {
1537         int i, curr;
1538         __be32 crc;
1539         struct batadv_bcast_packet *bcast_packet;
1540         struct batadv_bcast_duplist_entry *entry;
1541         bool ret = false;
1542
1543         bcast_packet = (struct batadv_bcast_packet *)skb->data;
1544
1545         /* calculate the crc ... */
1546         crc = batadv_skb_crc32(skb, (u8 *)(bcast_packet + 1));
1547
1548         spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
1549
1550         for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
1551                 curr = (bat_priv->bla.bcast_duplist_curr + i);
1552                 curr %= BATADV_DUPLIST_SIZE;
1553                 entry = &bat_priv->bla.bcast_duplist[curr];
1554
1555                 /* we can stop searching if the entry is too old ;
1556                  * later entries will be even older
1557                  */
1558                 if (batadv_has_timed_out(entry->entrytime,
1559                                          BATADV_DUPLIST_TIMEOUT))
1560                         break;
1561
1562                 if (entry->crc != crc)
1563                         continue;
1564
1565                 if (batadv_compare_eth(entry->orig, bcast_packet->orig))
1566                         continue;
1567
1568                 /* this entry seems to match: same crc, not too old,
1569                  * and from another gw. therefore return true to forbid it.
1570                  */
1571                 ret = true;
1572                 goto out;
1573         }
1574         /* not found, add a new entry (overwrite the oldest entry)
1575          * and allow it, its the first occurrence.
1576          */
1577         curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
1578         curr %= BATADV_DUPLIST_SIZE;
1579         entry = &bat_priv->bla.bcast_duplist[curr];
1580         entry->crc = crc;
1581         entry->entrytime = jiffies;
1582         ether_addr_copy(entry->orig, bcast_packet->orig);
1583         bat_priv->bla.bcast_duplist_curr = curr;
1584
1585 out:
1586         spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
1587
1588         return ret;
1589 }
1590
1591 /**
1592  * batadv_bla_is_backbone_gw_orig - Check if the originator is a gateway for
1593  *  the VLAN identified by vid.
1594  * @bat_priv: the bat priv with all the soft interface information
1595  * @orig: originator mac address
1596  * @vid: VLAN identifier
1597  *
1598  * Return: true if orig is a backbone for this vid, false otherwise.
1599  */
1600 bool batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, u8 *orig,
1601                                     unsigned short vid)
1602 {
1603         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1604         struct hlist_head *head;
1605         struct batadv_bla_backbone_gw *backbone_gw;
1606         int i;
1607
1608         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1609                 return false;
1610
1611         if (!hash)
1612                 return false;
1613
1614         for (i = 0; i < hash->size; i++) {
1615                 head = &hash->table[i];
1616
1617                 rcu_read_lock();
1618                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1619                         if (batadv_compare_eth(backbone_gw->orig, orig) &&
1620                             backbone_gw->vid == vid) {
1621                                 rcu_read_unlock();
1622                                 return true;
1623                         }
1624                 }
1625                 rcu_read_unlock();
1626         }
1627
1628         return false;
1629 }
1630
1631 /**
1632  * batadv_bla_is_backbone_gw - check if originator is a backbone gw for a VLAN.
1633  * @skb: the frame to be checked
1634  * @orig_node: the orig_node of the frame
1635  * @hdr_size: maximum length of the frame
1636  *
1637  * Return: true if the orig_node is also a gateway on the soft interface,
1638  * otherwise it returns false.
1639  */
1640 bool batadv_bla_is_backbone_gw(struct sk_buff *skb,
1641                                struct batadv_orig_node *orig_node, int hdr_size)
1642 {
1643         struct batadv_bla_backbone_gw *backbone_gw;
1644         unsigned short vid;
1645
1646         if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
1647                 return false;
1648
1649         /* first, find out the vid. */
1650         if (!pskb_may_pull(skb, hdr_size + ETH_HLEN))
1651                 return false;
1652
1653         vid = batadv_get_vid(skb, hdr_size);
1654
1655         /* see if this originator is a backbone gw for this VLAN */
1656         backbone_gw = batadv_backbone_hash_find(orig_node->bat_priv,
1657                                                 orig_node->orig, vid);
1658         if (!backbone_gw)
1659                 return false;
1660
1661         batadv_backbone_gw_put(backbone_gw);
1662         return true;
1663 }
1664
1665 /**
1666  * batadv_bla_free - free all bla structures
1667  * @bat_priv: the bat priv with all the soft interface information
1668  *
1669  * for softinterface free or module unload
1670  */
1671 void batadv_bla_free(struct batadv_priv *bat_priv)
1672 {
1673         struct batadv_hard_iface *primary_if;
1674
1675         cancel_delayed_work_sync(&bat_priv->bla.work);
1676         primary_if = batadv_primary_if_get_selected(bat_priv);
1677
1678         if (bat_priv->bla.claim_hash) {
1679                 batadv_bla_purge_claims(bat_priv, primary_if, 1);
1680                 batadv_hash_destroy(bat_priv->bla.claim_hash);
1681                 bat_priv->bla.claim_hash = NULL;
1682         }
1683         if (bat_priv->bla.backbone_hash) {
1684                 batadv_bla_purge_backbone_gw(bat_priv, 1);
1685                 batadv_hash_destroy(bat_priv->bla.backbone_hash);
1686                 bat_priv->bla.backbone_hash = NULL;
1687         }
1688         if (primary_if)
1689                 batadv_hardif_put(primary_if);
1690 }
1691
1692 /**
1693  * batadv_bla_loopdetect_check - check and handle a detected loop
1694  * @bat_priv: the bat priv with all the soft interface information
1695  * @skb: the packet to check
1696  * @primary_if: interface where the request came on
1697  * @vid: the VLAN ID of the frame
1698  *
1699  * Checks if this packet is a loop detect frame which has been sent by us,
1700  * throw an uevent and log the event if that is the case.
1701  *
1702  * Return: true if it is a loop detect frame which is to be dropped, false
1703  * otherwise.
1704  */
1705 static bool
1706 batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb,
1707                             struct batadv_hard_iface *primary_if,
1708                             unsigned short vid)
1709 {
1710         struct batadv_bla_backbone_gw *backbone_gw;
1711         struct ethhdr *ethhdr;
1712
1713         ethhdr = eth_hdr(skb);
1714
1715         /* Only check for the MAC address and skip more checks here for
1716          * performance reasons - this function is on the hotpath, after all.
1717          */
1718         if (!batadv_compare_eth(ethhdr->h_source,
1719                                 bat_priv->bla.loopdetect_addr))
1720                 return false;
1721
1722         /* If the packet came too late, don't forward it on the mesh
1723          * but don't consider that as loop. It might be a coincidence.
1724          */
1725         if (batadv_has_timed_out(bat_priv->bla.loopdetect_lasttime,
1726                                  BATADV_BLA_LOOPDETECT_TIMEOUT))
1727                 return true;
1728
1729         backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
1730                                                  primary_if->net_dev->dev_addr,
1731                                                  vid, true);
1732         if (unlikely(!backbone_gw))
1733                 return true;
1734
1735         queue_work(batadv_event_workqueue, &backbone_gw->report_work);
1736         /* backbone_gw is unreferenced in the report work function function */
1737
1738         return true;
1739 }
1740
1741 /**
1742  * batadv_bla_rx - check packets coming from the mesh.
1743  * @bat_priv: the bat priv with all the soft interface information
1744  * @skb: the frame to be checked
1745  * @vid: the VLAN ID of the frame
1746  * @is_bcast: the packet came in a broadcast packet type.
1747  *
1748  * batadv_bla_rx avoidance checks if:
1749  *  * we have to race for a claim
1750  *  * if the frame is allowed on the LAN
1751  *
1752  * in these cases, the skb is further handled by this function
1753  *
1754  * Return: true if handled, otherwise it returns false and the caller shall
1755  * further process the skb.
1756  */
1757 bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1758                    unsigned short vid, bool is_bcast)
1759 {
1760         struct ethhdr *ethhdr;
1761         struct batadv_bla_claim search_claim, *claim = NULL;
1762         struct batadv_hard_iface *primary_if;
1763         bool ret;
1764
1765         ethhdr = eth_hdr(skb);
1766
1767         primary_if = batadv_primary_if_get_selected(bat_priv);
1768         if (!primary_if)
1769                 goto handled;
1770
1771         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1772                 goto allow;
1773
1774         if (batadv_bla_loopdetect_check(bat_priv, skb, primary_if, vid))
1775                 goto handled;
1776
1777         if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1778                 /* don't allow broadcasts while requests are in flight */
1779                 if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast)
1780                         goto handled;
1781
1782         ether_addr_copy(search_claim.addr, ethhdr->h_source);
1783         search_claim.vid = vid;
1784         claim = batadv_claim_hash_find(bat_priv, &search_claim);
1785
1786         if (!claim) {
1787                 /* possible optimization: race for a claim */
1788                 /* No claim exists yet, claim it for us!
1789                  */
1790                 batadv_handle_claim(bat_priv, primary_if,
1791                                     primary_if->net_dev->dev_addr,
1792                                     ethhdr->h_source, vid);
1793                 goto allow;
1794         }
1795
1796         /* if it is our own claim ... */
1797         if (batadv_compare_eth(claim->backbone_gw->orig,
1798                                primary_if->net_dev->dev_addr)) {
1799                 /* ... allow it in any case */
1800                 claim->lasttime = jiffies;
1801                 goto allow;
1802         }
1803
1804         /* if it is a broadcast ... */
1805         if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) {
1806                 /* ... drop it. the responsible gateway is in charge.
1807                  *
1808                  * We need to check is_bcast because with the gateway
1809                  * feature, broadcasts (like DHCP requests) may be sent
1810                  * using a unicast packet type.
1811                  */
1812                 goto handled;
1813         } else {
1814                 /* seems the client considers us as its best gateway.
1815                  * send a claim and update the claim table
1816                  * immediately.
1817                  */
1818                 batadv_handle_claim(bat_priv, primary_if,
1819                                     primary_if->net_dev->dev_addr,
1820                                     ethhdr->h_source, vid);
1821                 goto allow;
1822         }
1823 allow:
1824         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1825         ret = false;
1826         goto out;
1827
1828 handled:
1829         kfree_skb(skb);
1830         ret = true;
1831
1832 out:
1833         if (primary_if)
1834                 batadv_hardif_put(primary_if);
1835         if (claim)
1836                 batadv_claim_put(claim);
1837         return ret;
1838 }
1839
1840 /**
1841  * batadv_bla_tx - check packets going into the mesh
1842  * @bat_priv: the bat priv with all the soft interface information
1843  * @skb: the frame to be checked
1844  * @vid: the VLAN ID of the frame
1845  *
1846  * batadv_bla_tx checks if:
1847  *  * a claim was received which has to be processed
1848  *  * the frame is allowed on the mesh
1849  *
1850  * in these cases, the skb is further handled by this function.
1851  *
1852  * This call might reallocate skb data.
1853  *
1854  * Return: true if handled, otherwise it returns false and the caller shall
1855  * further process the skb.
1856  */
1857 bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1858                    unsigned short vid)
1859 {
1860         struct ethhdr *ethhdr;
1861         struct batadv_bla_claim search_claim, *claim = NULL;
1862         struct batadv_hard_iface *primary_if;
1863         bool ret = false;
1864
1865         primary_if = batadv_primary_if_get_selected(bat_priv);
1866         if (!primary_if)
1867                 goto out;
1868
1869         if (!atomic_read(&bat_priv->bridge_loop_avoidance))
1870                 goto allow;
1871
1872         if (batadv_bla_process_claim(bat_priv, primary_if, skb))
1873                 goto handled;
1874
1875         ethhdr = eth_hdr(skb);
1876
1877         if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1878                 /* don't allow broadcasts while requests are in flight */
1879                 if (is_multicast_ether_addr(ethhdr->h_dest))
1880                         goto handled;
1881
1882         ether_addr_copy(search_claim.addr, ethhdr->h_source);
1883         search_claim.vid = vid;
1884
1885         claim = batadv_claim_hash_find(bat_priv, &search_claim);
1886
1887         /* if no claim exists, allow it. */
1888         if (!claim)
1889                 goto allow;
1890
1891         /* check if we are responsible. */
1892         if (batadv_compare_eth(claim->backbone_gw->orig,
1893                                primary_if->net_dev->dev_addr)) {
1894                 /* if yes, the client has roamed and we have
1895                  * to unclaim it.
1896                  */
1897                 batadv_handle_unclaim(bat_priv, primary_if,
1898                                       primary_if->net_dev->dev_addr,
1899                                       ethhdr->h_source, vid);
1900                 goto allow;
1901         }
1902
1903         /* check if it is a multicast/broadcast frame */
1904         if (is_multicast_ether_addr(ethhdr->h_dest)) {
1905                 /* drop it. the responsible gateway has forwarded it into
1906                  * the backbone network.
1907                  */
1908                 goto handled;
1909         } else {
1910                 /* we must allow it. at least if we are
1911                  * responsible for the DESTINATION.
1912                  */
1913                 goto allow;
1914         }
1915 allow:
1916         batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1917         ret = false;
1918         goto out;
1919 handled:
1920         ret = true;
1921 out:
1922         if (primary_if)
1923                 batadv_hardif_put(primary_if);
1924         if (claim)
1925                 batadv_claim_put(claim);
1926         return ret;
1927 }
1928
1929 /**
1930  * batadv_bla_claim_table_seq_print_text - print the claim table in a seq file
1931  * @seq: seq file to print on
1932  * @offset: not used
1933  *
1934  * Return: always 0
1935  */
1936 int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset)
1937 {
1938         struct net_device *net_dev = (struct net_device *)seq->private;
1939         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1940         struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
1941         struct batadv_bla_claim *claim;
1942         struct batadv_hard_iface *primary_if;
1943         struct hlist_head *head;
1944         u16 backbone_crc;
1945         u32 i;
1946         bool is_own;
1947         u8 *primary_addr;
1948
1949         primary_if = batadv_seq_print_text_primary_if_get(seq);
1950         if (!primary_if)
1951                 goto out;
1952
1953         primary_addr = primary_if->net_dev->dev_addr;
1954         seq_printf(seq,
1955                    "Claims announced for the mesh %s (orig %pM, group id %#.4x)\n",
1956                    net_dev->name, primary_addr,
1957                    ntohs(bat_priv->bla.claim_dest.group));
1958         seq_puts(seq,
1959                  "   Client               VID      Originator        [o] (CRC   )\n");
1960         for (i = 0; i < hash->size; i++) {
1961                 head = &hash->table[i];
1962
1963                 rcu_read_lock();
1964                 hlist_for_each_entry_rcu(claim, head, hash_entry) {
1965                         is_own = batadv_compare_eth(claim->backbone_gw->orig,
1966                                                     primary_addr);
1967
1968                         spin_lock_bh(&claim->backbone_gw->crc_lock);
1969                         backbone_crc = claim->backbone_gw->crc;
1970                         spin_unlock_bh(&claim->backbone_gw->crc_lock);
1971                         seq_printf(seq, " * %pM on %5d by %pM [%c] (%#.4x)\n",
1972                                    claim->addr, BATADV_PRINT_VID(claim->vid),
1973                                    claim->backbone_gw->orig,
1974                                    (is_own ? 'x' : ' '),
1975                                    backbone_crc);
1976                 }
1977                 rcu_read_unlock();
1978         }
1979 out:
1980         if (primary_if)
1981                 batadv_hardif_put(primary_if);
1982         return 0;
1983 }
1984
1985 /**
1986  * batadv_bla_backbone_table_seq_print_text - print the backbone table in a seq
1987  *  file
1988  * @seq: seq file to print on
1989  * @offset: not used
1990  *
1991  * Return: always 0
1992  */
1993 int batadv_bla_backbone_table_seq_print_text(struct seq_file *seq, void *offset)
1994 {
1995         struct net_device *net_dev = (struct net_device *)seq->private;
1996         struct batadv_priv *bat_priv = netdev_priv(net_dev);
1997         struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1998         struct batadv_bla_backbone_gw *backbone_gw;
1999         struct batadv_hard_iface *primary_if;
2000         struct hlist_head *head;
2001         int secs, msecs;
2002         u16 backbone_crc;
2003         u32 i;
2004         bool is_own;
2005         u8 *primary_addr;
2006
2007         primary_if = batadv_seq_print_text_primary_if_get(seq);
2008         if (!primary_if)
2009                 goto out;
2010
2011         primary_addr = primary_if->net_dev->dev_addr;
2012         seq_printf(seq,
2013                    "Backbones announced for the mesh %s (orig %pM, group id %#.4x)\n",
2014                    net_dev->name, primary_addr,
2015                    ntohs(bat_priv->bla.claim_dest.group));
2016         seq_puts(seq, "   Originator           VID   last seen (CRC   )\n");
2017         for (i = 0; i < hash->size; i++) {
2018                 head = &hash->table[i];
2019
2020                 rcu_read_lock();
2021                 hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
2022                         msecs = jiffies_to_msecs(jiffies -
2023                                                  backbone_gw->lasttime);
2024                         secs = msecs / 1000;
2025                         msecs = msecs % 1000;
2026
2027                         is_own = batadv_compare_eth(backbone_gw->orig,
2028                                                     primary_addr);
2029                         if (is_own)
2030                                 continue;
2031
2032                         spin_lock_bh(&backbone_gw->crc_lock);
2033                         backbone_crc = backbone_gw->crc;
2034                         spin_unlock_bh(&backbone_gw->crc_lock);
2035
2036                         seq_printf(seq, " * %pM on %5d %4i.%03is (%#.4x)\n",
2037                                    backbone_gw->orig,
2038                                    BATADV_PRINT_VID(backbone_gw->vid), secs,
2039                                    msecs, backbone_crc);
2040                 }
2041                 rcu_read_unlock();
2042         }
2043 out:
2044         if (primary_if)
2045                 batadv_hardif_put(primary_if);
2046         return 0;
2047 }