1 /* Copyright (C) 2011-2012 B.A.T.M.A.N. contributors: 2 * 3 * Simon Wunderlich 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of version 2 of the GNU General Public 7 * License as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, but 10 * WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 17 * 02110-1301, USA 18 */ 19 20 #include "main.h" 21 #include "hash.h" 22 #include "hard-interface.h" 23 #include "originator.h" 24 #include "bridge_loop_avoidance.h" 25 #include "translation-table.h" 26 #include "send.h" 27 28 #include <linux/etherdevice.h> 29 #include <linux/crc16.h> 30 #include <linux/if_arp.h> 31 #include <net/arp.h> 32 #include <linux/if_vlan.h> 33 34 static const uint8_t batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05}; 35 36 static void batadv_bla_periodic_work(struct work_struct *work); 37 static void batadv_bla_send_announce(struct batadv_priv *bat_priv, 38 struct batadv_backbone_gw *backbone_gw); 39 40 /* return the index of the claim */ 41 static inline uint32_t batadv_choose_claim(const void *data, uint32_t size) 42 { 43 const unsigned char *key = data; 44 uint32_t hash = 0; 45 size_t i; 46 47 for (i = 0; i < ETH_ALEN + sizeof(short); i++) { 48 hash += key[i]; 49 hash += (hash << 10); 50 hash ^= (hash >> 6); 51 } 52 53 hash += (hash << 3); 54 hash ^= (hash >> 11); 55 hash += (hash << 15); 56 57 return hash % size; 58 } 59 60 /* return the index of the backbone gateway */ 61 static inline uint32_t batadv_choose_backbone_gw(const void *data, 62 uint32_t size) 63 { 64 const unsigned char *key = data; 65 uint32_t hash = 0; 66 size_t i; 67 68 for (i = 0; i < ETH_ALEN + sizeof(short); i++) { 69 hash += key[i]; 70 hash += (hash << 10); 71 hash ^= (hash >> 6); 72 } 73 74 hash += (hash << 3); 75 hash ^= (hash >> 11); 76 hash += (hash << 15); 77 78 return hash % size; 79 } 80 81 82 /* compares address and vid of two backbone gws */ 83 static int batadv_compare_backbone_gw(const struct hlist_node *node, 84 const void *data2) 85 { 86 const void *data1 = container_of(node, struct batadv_backbone_gw, 87 hash_entry); 88 89 return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0); 90 } 91 92 /* compares address and vid of two claims */ 93 static int batadv_compare_claim(const struct hlist_node *node, 94 const void *data2) 95 { 96 const void *data1 = container_of(node, struct batadv_claim, 97 hash_entry); 98 99 return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0); 100 } 101 102 /* free a backbone gw */ 103 static void batadv_backbone_gw_free_ref(struct batadv_backbone_gw *backbone_gw) 104 { 105 if (atomic_dec_and_test(&backbone_gw->refcount)) 106 kfree_rcu(backbone_gw, rcu); 107 } 108 109 /* finally deinitialize the claim */ 110 static void batadv_claim_free_rcu(struct rcu_head *rcu) 111 { 112 struct batadv_claim *claim; 113 114 claim = container_of(rcu, struct batadv_claim, rcu); 115 116 batadv_backbone_gw_free_ref(claim->backbone_gw); 117 kfree(claim); 118 } 119 120 /* free a claim, call claim_free_rcu if its the last reference */ 121 static void batadv_claim_free_ref(struct batadv_claim *claim) 122 { 123 if (atomic_dec_and_test(&claim->refcount)) 124 call_rcu(&claim->rcu, batadv_claim_free_rcu); 125 } 126 127 /* @bat_priv: the bat priv with all the soft interface information 128 * @data: search data (may be local/static data) 129 * 130 * looks for a claim in the hash, and returns it if found 131 * or NULL otherwise. 132 */ 133 static struct batadv_claim *batadv_claim_hash_find(struct batadv_priv *bat_priv, 134 struct batadv_claim *data) 135 { 136 struct batadv_hashtable *hash = bat_priv->claim_hash; 137 struct hlist_head *head; 138 struct hlist_node *node; 139 struct batadv_claim *claim; 140 struct batadv_claim *claim_tmp = NULL; 141 int index; 142 143 if (!hash) 144 return NULL; 145 146 index = batadv_choose_claim(data, hash->size); 147 head = &hash->table[index]; 148 149 rcu_read_lock(); 150 hlist_for_each_entry_rcu(claim, node, head, hash_entry) { 151 if (!batadv_compare_claim(&claim->hash_entry, data)) 152 continue; 153 154 if (!atomic_inc_not_zero(&claim->refcount)) 155 continue; 156 157 claim_tmp = claim; 158 break; 159 } 160 rcu_read_unlock(); 161 162 return claim_tmp; 163 } 164 165 /** 166 * batadv_backbone_hash_find - looks for a claim in the hash 167 * @bat_priv: the bat priv with all the soft interface information 168 * @addr: the address of the originator 169 * @vid: the VLAN ID 170 * 171 * Returns claim if found or NULL otherwise. 172 */ 173 static struct batadv_backbone_gw * 174 batadv_backbone_hash_find(struct batadv_priv *bat_priv, 175 uint8_t *addr, short vid) 176 { 177 struct batadv_hashtable *hash = bat_priv->backbone_hash; 178 struct hlist_head *head; 179 struct hlist_node *node; 180 struct batadv_backbone_gw search_entry, *backbone_gw; 181 struct batadv_backbone_gw *backbone_gw_tmp = NULL; 182 int index; 183 184 if (!hash) 185 return NULL; 186 187 memcpy(search_entry.orig, addr, ETH_ALEN); 188 search_entry.vid = vid; 189 190 index = batadv_choose_backbone_gw(&search_entry, hash->size); 191 head = &hash->table[index]; 192 193 rcu_read_lock(); 194 hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) { 195 if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry, 196 &search_entry)) 197 continue; 198 199 if (!atomic_inc_not_zero(&backbone_gw->refcount)) 200 continue; 201 202 backbone_gw_tmp = backbone_gw; 203 break; 204 } 205 rcu_read_unlock(); 206 207 return backbone_gw_tmp; 208 } 209 210 /* delete all claims for a backbone */ 211 static void 212 batadv_bla_del_backbone_claims(struct batadv_backbone_gw *backbone_gw) 213 { 214 struct batadv_hashtable *hash; 215 struct hlist_node *node, *node_tmp; 216 struct hlist_head *head; 217 struct batadv_claim *claim; 218 int i; 219 spinlock_t *list_lock; /* protects write access to the hash lists */ 220 221 hash = backbone_gw->bat_priv->claim_hash; 222 if (!hash) 223 return; 224 225 for (i = 0; i < hash->size; i++) { 226 head = &hash->table[i]; 227 list_lock = &hash->list_locks[i]; 228 229 spin_lock_bh(list_lock); 230 hlist_for_each_entry_safe(claim, node, node_tmp, 231 head, hash_entry) { 232 233 if (claim->backbone_gw != backbone_gw) 234 continue; 235 236 batadv_claim_free_ref(claim); 237 hlist_del_rcu(node); 238 } 239 spin_unlock_bh(list_lock); 240 } 241 242 /* all claims gone, intialize CRC */ 243 backbone_gw->crc = BATADV_BLA_CRC_INIT; 244 } 245 246 /** 247 * batadv_bla_send_claim - sends a claim frame according to the provided info 248 * @bat_priv: the bat priv with all the soft interface information 249 * @orig: the mac address to be announced within the claim 250 * @vid: the VLAN ID 251 * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...) 252 */ 253 static void batadv_bla_send_claim(struct batadv_priv *bat_priv, uint8_t *mac, 254 short vid, int claimtype) 255 { 256 struct sk_buff *skb; 257 struct ethhdr *ethhdr; 258 struct batadv_hard_iface *primary_if; 259 struct net_device *soft_iface; 260 uint8_t *hw_src; 261 struct batadv_bla_claim_dst local_claim_dest; 262 __be32 zeroip = 0; 263 264 primary_if = batadv_primary_if_get_selected(bat_priv); 265 if (!primary_if) 266 return; 267 268 memcpy(&local_claim_dest, &bat_priv->claim_dest, 269 sizeof(local_claim_dest)); 270 local_claim_dest.type = claimtype; 271 272 soft_iface = primary_if->soft_iface; 273 274 skb = arp_create(ARPOP_REPLY, ETH_P_ARP, 275 /* IP DST: 0.0.0.0 */ 276 zeroip, 277 primary_if->soft_iface, 278 /* IP SRC: 0.0.0.0 */ 279 zeroip, 280 /* Ethernet DST: Broadcast */ 281 NULL, 282 /* Ethernet SRC/HW SRC: originator mac */ 283 primary_if->net_dev->dev_addr, 284 /* HW DST: FF:43:05:XX:00:00 285 * with XX = claim type 286 * and YY:YY = group id 287 */ 288 (uint8_t *)&local_claim_dest); 289 290 if (!skb) 291 goto out; 292 293 ethhdr = (struct ethhdr *)skb->data; 294 hw_src = (uint8_t *)ethhdr + ETH_HLEN + sizeof(struct arphdr); 295 296 /* now we pretend that the client would have sent this ... */ 297 switch (claimtype) { 298 case BATADV_CLAIM_TYPE_ADD: 299 /* normal claim frame 300 * set Ethernet SRC to the clients mac 301 */ 302 memcpy(ethhdr->h_source, mac, ETH_ALEN); 303 batadv_dbg(BATADV_DBG_BLA, bat_priv, 304 "bla_send_claim(): CLAIM %pM on vid %d\n", mac, vid); 305 break; 306 case BATADV_CLAIM_TYPE_DEL: 307 /* unclaim frame 308 * set HW SRC to the clients mac 309 */ 310 memcpy(hw_src, mac, ETH_ALEN); 311 batadv_dbg(BATADV_DBG_BLA, bat_priv, 312 "bla_send_claim(): UNCLAIM %pM on vid %d\n", mac, 313 vid); 314 break; 315 case BATADV_CLAIM_TYPE_ANNOUNCE: 316 /* announcement frame 317 * set HW SRC to the special mac containg the crc 318 */ 319 memcpy(hw_src, mac, ETH_ALEN); 320 batadv_dbg(BATADV_DBG_BLA, bat_priv, 321 "bla_send_claim(): ANNOUNCE of %pM on vid %d\n", 322 ethhdr->h_source, vid); 323 break; 324 case BATADV_CLAIM_TYPE_REQUEST: 325 /* request frame 326 * set HW SRC to the special mac containg the crc 327 */ 328 memcpy(hw_src, mac, ETH_ALEN); 329 memcpy(ethhdr->h_dest, mac, ETH_ALEN); 330 batadv_dbg(BATADV_DBG_BLA, bat_priv, 331 "bla_send_claim(): REQUEST of %pM to %pMon vid %d\n", 332 ethhdr->h_source, ethhdr->h_dest, vid); 333 break; 334 335 } 336 337 if (vid != -1) 338 skb = vlan_insert_tag(skb, vid); 339 340 skb_reset_mac_header(skb); 341 skb->protocol = eth_type_trans(skb, soft_iface); 342 bat_priv->stats.rx_packets++; 343 bat_priv->stats.rx_bytes += skb->len + ETH_HLEN; 344 soft_iface->last_rx = jiffies; 345 346 netif_rx(skb); 347 out: 348 if (primary_if) 349 batadv_hardif_free_ref(primary_if); 350 } 351 352 /** 353 * batadv_bla_get_backbone_gw 354 * @bat_priv: the bat priv with all the soft interface information 355 * @orig: the mac address of the originator 356 * @vid: the VLAN ID 357 * 358 * searches for the backbone gw or creates a new one if it could not 359 * be found. 360 */ 361 static struct batadv_backbone_gw * 362 batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig, 363 short vid) 364 { 365 struct batadv_backbone_gw *entry; 366 struct batadv_orig_node *orig_node; 367 int hash_added; 368 369 entry = batadv_backbone_hash_find(bat_priv, orig, vid); 370 371 if (entry) 372 return entry; 373 374 batadv_dbg(BATADV_DBG_BLA, bat_priv, 375 "bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n", 376 orig, vid); 377 378 entry = kzalloc(sizeof(*entry), GFP_ATOMIC); 379 if (!entry) 380 return NULL; 381 382 entry->vid = vid; 383 entry->lasttime = jiffies; 384 entry->crc = BATADV_BLA_CRC_INIT; 385 entry->bat_priv = bat_priv; 386 atomic_set(&entry->request_sent, 0); 387 memcpy(entry->orig, orig, ETH_ALEN); 388 389 /* one for the hash, one for returning */ 390 atomic_set(&entry->refcount, 2); 391 392 hash_added = batadv_hash_add(bat_priv->backbone_hash, 393 batadv_compare_backbone_gw, 394 batadv_choose_backbone_gw, entry, 395 &entry->hash_entry); 396 397 if (unlikely(hash_added != 0)) { 398 /* hash failed, free the structure */ 399 kfree(entry); 400 return NULL; 401 } 402 403 /* this is a gateway now, remove any tt entries */ 404 orig_node = batadv_orig_hash_find(bat_priv, orig); 405 if (orig_node) { 406 batadv_tt_global_del_orig(bat_priv, orig_node, 407 "became a backbone gateway"); 408 batadv_orig_node_free_ref(orig_node); 409 } 410 return entry; 411 } 412 413 /* update or add the own backbone gw to make sure we announce 414 * where we receive other backbone gws 415 */ 416 static void 417 batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv, 418 struct batadv_hard_iface *primary_if, 419 short vid) 420 { 421 struct batadv_backbone_gw *backbone_gw; 422 423 backbone_gw = batadv_bla_get_backbone_gw(bat_priv, 424 primary_if->net_dev->dev_addr, 425 vid); 426 if (unlikely(!backbone_gw)) 427 return; 428 429 backbone_gw->lasttime = jiffies; 430 batadv_backbone_gw_free_ref(backbone_gw); 431 } 432 433 /* @bat_priv: the bat priv with all the soft interface information 434 * @vid: the vid where the request came on 435 * 436 * Repeat all of our own claims, and finally send an ANNOUNCE frame 437 * to allow the requester another check if the CRC is correct now. 438 */ 439 static void batadv_bla_answer_request(struct batadv_priv *bat_priv, 440 struct batadv_hard_iface *primary_if, 441 short vid) 442 { 443 struct hlist_node *node; 444 struct hlist_head *head; 445 struct batadv_hashtable *hash; 446 struct batadv_claim *claim; 447 struct batadv_backbone_gw *backbone_gw; 448 int i; 449 450 batadv_dbg(BATADV_DBG_BLA, bat_priv, 451 "bla_answer_request(): received a claim request, send all of our own claims again\n"); 452 453 backbone_gw = batadv_backbone_hash_find(bat_priv, 454 primary_if->net_dev->dev_addr, 455 vid); 456 if (!backbone_gw) 457 return; 458 459 hash = bat_priv->claim_hash; 460 for (i = 0; i < hash->size; i++) { 461 head = &hash->table[i]; 462 463 rcu_read_lock(); 464 hlist_for_each_entry_rcu(claim, node, head, hash_entry) { 465 /* only own claims are interesting */ 466 if (claim->backbone_gw != backbone_gw) 467 continue; 468 469 batadv_bla_send_claim(bat_priv, claim->addr, claim->vid, 470 BATADV_CLAIM_TYPE_ADD); 471 } 472 rcu_read_unlock(); 473 } 474 475 /* finally, send an announcement frame */ 476 batadv_bla_send_announce(bat_priv, backbone_gw); 477 batadv_backbone_gw_free_ref(backbone_gw); 478 } 479 480 /* @backbone_gw: the backbone gateway from whom we are out of sync 481 * 482 * When the crc is wrong, ask the backbone gateway for a full table update. 483 * After the request, it will repeat all of his own claims and finally 484 * send an announcement claim with which we can check again. 485 */ 486 static void batadv_bla_send_request(struct batadv_backbone_gw *backbone_gw) 487 { 488 /* first, remove all old entries */ 489 batadv_bla_del_backbone_claims(backbone_gw); 490 491 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, 492 "Sending REQUEST to %pM\n", backbone_gw->orig); 493 494 /* send request */ 495 batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig, 496 backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST); 497 498 /* no local broadcasts should be sent or received, for now. */ 499 if (!atomic_read(&backbone_gw->request_sent)) { 500 atomic_inc(&backbone_gw->bat_priv->bla_num_requests); 501 atomic_set(&backbone_gw->request_sent, 1); 502 } 503 } 504 505 /* @bat_priv: the bat priv with all the soft interface information 506 * @backbone_gw: our backbone gateway which should be announced 507 * 508 * This function sends an announcement. It is called from multiple 509 * places. 510 */ 511 static void batadv_bla_send_announce(struct batadv_priv *bat_priv, 512 struct batadv_backbone_gw *backbone_gw) 513 { 514 uint8_t mac[ETH_ALEN]; 515 __be16 crc; 516 517 memcpy(mac, batadv_announce_mac, 4); 518 crc = htons(backbone_gw->crc); 519 memcpy(&mac[4], &crc, 2); 520 521 batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid, 522 BATADV_CLAIM_TYPE_ANNOUNCE); 523 524 } 525 526 /** 527 * batadv_bla_add_claim - Adds a claim in the claim hash 528 * @bat_priv: the bat priv with all the soft interface information 529 * @mac: the mac address of the claim 530 * @vid: the VLAN ID of the frame 531 * @backbone_gw: the backbone gateway which claims it 532 */ 533 static void batadv_bla_add_claim(struct batadv_priv *bat_priv, 534 const uint8_t *mac, const short vid, 535 struct batadv_backbone_gw *backbone_gw) 536 { 537 struct batadv_claim *claim; 538 struct batadv_claim search_claim; 539 int hash_added; 540 541 memcpy(search_claim.addr, mac, ETH_ALEN); 542 search_claim.vid = vid; 543 claim = batadv_claim_hash_find(bat_priv, &search_claim); 544 545 /* create a new claim entry if it does not exist yet. */ 546 if (!claim) { 547 claim = kzalloc(sizeof(*claim), GFP_ATOMIC); 548 if (!claim) 549 return; 550 551 memcpy(claim->addr, mac, ETH_ALEN); 552 claim->vid = vid; 553 claim->lasttime = jiffies; 554 claim->backbone_gw = backbone_gw; 555 556 atomic_set(&claim->refcount, 2); 557 batadv_dbg(BATADV_DBG_BLA, bat_priv, 558 "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n", 559 mac, vid); 560 hash_added = batadv_hash_add(bat_priv->claim_hash, 561 batadv_compare_claim, 562 batadv_choose_claim, claim, 563 &claim->hash_entry); 564 565 if (unlikely(hash_added != 0)) { 566 /* only local changes happened. */ 567 kfree(claim); 568 return; 569 } 570 } else { 571 claim->lasttime = jiffies; 572 if (claim->backbone_gw == backbone_gw) 573 /* no need to register a new backbone */ 574 goto claim_free_ref; 575 576 batadv_dbg(BATADV_DBG_BLA, bat_priv, 577 "bla_add_claim(): changing ownership for %pM, vid %d\n", 578 mac, vid); 579 580 claim->backbone_gw->crc ^= 581 crc16(0, claim->addr, ETH_ALEN); 582 batadv_backbone_gw_free_ref(claim->backbone_gw); 583 584 } 585 /* set (new) backbone gw */ 586 atomic_inc(&backbone_gw->refcount); 587 claim->backbone_gw = backbone_gw; 588 589 backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); 590 backbone_gw->lasttime = jiffies; 591 592 claim_free_ref: 593 batadv_claim_free_ref(claim); 594 } 595 596 /* Delete a claim from the claim hash which has the 597 * given mac address and vid. 598 */ 599 static void batadv_bla_del_claim(struct batadv_priv *bat_priv, 600 const uint8_t *mac, const short vid) 601 { 602 struct batadv_claim search_claim, *claim; 603 604 memcpy(search_claim.addr, mac, ETH_ALEN); 605 search_claim.vid = vid; 606 claim = batadv_claim_hash_find(bat_priv, &search_claim); 607 if (!claim) 608 return; 609 610 batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n", 611 mac, vid); 612 613 batadv_hash_remove(bat_priv->claim_hash, batadv_compare_claim, 614 batadv_choose_claim, claim); 615 batadv_claim_free_ref(claim); /* reference from the hash is gone */ 616 617 claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); 618 619 /* don't need the reference from hash_find() anymore */ 620 batadv_claim_free_ref(claim); 621 } 622 623 /* check for ANNOUNCE frame, return 1 if handled */ 624 static int batadv_handle_announce(struct batadv_priv *bat_priv, 625 uint8_t *an_addr, uint8_t *backbone_addr, 626 short vid) 627 { 628 struct batadv_backbone_gw *backbone_gw; 629 uint16_t crc; 630 631 if (memcmp(an_addr, batadv_announce_mac, 4) != 0) 632 return 0; 633 634 backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid); 635 636 if (unlikely(!backbone_gw)) 637 return 1; 638 639 640 /* handle as ANNOUNCE frame */ 641 backbone_gw->lasttime = jiffies; 642 crc = ntohs(*((__be16 *)(&an_addr[4]))); 643 644 batadv_dbg(BATADV_DBG_BLA, bat_priv, 645 "handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %04x\n", 646 vid, backbone_gw->orig, crc); 647 648 if (backbone_gw->crc != crc) { 649 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, 650 "handle_announce(): CRC FAILED for %pM/%d (my = %04x, sent = %04x)\n", 651 backbone_gw->orig, backbone_gw->vid, 652 backbone_gw->crc, crc); 653 654 batadv_bla_send_request(backbone_gw); 655 } else { 656 /* if we have sent a request and the crc was OK, 657 * we can allow traffic again. 658 */ 659 if (atomic_read(&backbone_gw->request_sent)) { 660 atomic_dec(&backbone_gw->bat_priv->bla_num_requests); 661 atomic_set(&backbone_gw->request_sent, 0); 662 } 663 } 664 665 batadv_backbone_gw_free_ref(backbone_gw); 666 return 1; 667 } 668 669 /* check for REQUEST frame, return 1 if handled */ 670 static int batadv_handle_request(struct batadv_priv *bat_priv, 671 struct batadv_hard_iface *primary_if, 672 uint8_t *backbone_addr, 673 struct ethhdr *ethhdr, short vid) 674 { 675 /* check for REQUEST frame */ 676 if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest)) 677 return 0; 678 679 /* sanity check, this should not happen on a normal switch, 680 * we ignore it in this case. 681 */ 682 if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr)) 683 return 1; 684 685 batadv_dbg(BATADV_DBG_BLA, bat_priv, 686 "handle_request(): REQUEST vid %d (sent by %pM)...\n", 687 vid, ethhdr->h_source); 688 689 batadv_bla_answer_request(bat_priv, primary_if, vid); 690 return 1; 691 } 692 693 /* check for UNCLAIM frame, return 1 if handled */ 694 static int batadv_handle_unclaim(struct batadv_priv *bat_priv, 695 struct batadv_hard_iface *primary_if, 696 uint8_t *backbone_addr, 697 uint8_t *claim_addr, short vid) 698 { 699 struct batadv_backbone_gw *backbone_gw; 700 701 /* unclaim in any case if it is our own */ 702 if (primary_if && batadv_compare_eth(backbone_addr, 703 primary_if->net_dev->dev_addr)) 704 batadv_bla_send_claim(bat_priv, claim_addr, vid, 705 BATADV_CLAIM_TYPE_DEL); 706 707 backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid); 708 709 if (!backbone_gw) 710 return 1; 711 712 /* this must be an UNCLAIM frame */ 713 batadv_dbg(BATADV_DBG_BLA, bat_priv, 714 "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n", 715 claim_addr, vid, backbone_gw->orig); 716 717 batadv_bla_del_claim(bat_priv, claim_addr, vid); 718 batadv_backbone_gw_free_ref(backbone_gw); 719 return 1; 720 } 721 722 /* check for CLAIM frame, return 1 if handled */ 723 static int batadv_handle_claim(struct batadv_priv *bat_priv, 724 struct batadv_hard_iface *primary_if, 725 uint8_t *backbone_addr, uint8_t *claim_addr, 726 short vid) 727 { 728 struct batadv_backbone_gw *backbone_gw; 729 730 /* register the gateway if not yet available, and add the claim. */ 731 732 backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid); 733 734 if (unlikely(!backbone_gw)) 735 return 1; 736 737 /* this must be a CLAIM frame */ 738 batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw); 739 if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) 740 batadv_bla_send_claim(bat_priv, claim_addr, vid, 741 BATADV_CLAIM_TYPE_ADD); 742 743 /* TODO: we could call something like tt_local_del() here. */ 744 745 batadv_backbone_gw_free_ref(backbone_gw); 746 return 1; 747 } 748 749 /** 750 * batadv_check_claim_group 751 * @bat_priv: the bat priv with all the soft interface information 752 * @hw_src: the Hardware source in the ARP Header 753 * @hw_dst: the Hardware destination in the ARP Header 754 * @ethhdr: pointer to the Ethernet header of the claim frame 755 * 756 * checks if it is a claim packet and if its on the same group. 757 * This function also applies the group ID of the sender 758 * if it is in the same mesh. 759 * 760 * returns: 761 * 2 - if it is a claim packet and on the same group 762 * 1 - if is a claim packet from another group 763 * 0 - if it is not a claim packet 764 */ 765 static int batadv_check_claim_group(struct batadv_priv *bat_priv, 766 struct batadv_hard_iface *primary_if, 767 uint8_t *hw_src, uint8_t *hw_dst, 768 struct ethhdr *ethhdr) 769 { 770 uint8_t *backbone_addr; 771 struct batadv_orig_node *orig_node; 772 struct batadv_bla_claim_dst *bla_dst, *bla_dst_own; 773 774 bla_dst = (struct batadv_bla_claim_dst *)hw_dst; 775 bla_dst_own = &bat_priv->claim_dest; 776 777 /* check if it is a claim packet in general */ 778 if (memcmp(bla_dst->magic, bla_dst_own->magic, 779 sizeof(bla_dst->magic)) != 0) 780 return 0; 781 782 /* if announcement packet, use the source, 783 * otherwise assume it is in the hw_src 784 */ 785 switch (bla_dst->type) { 786 case BATADV_CLAIM_TYPE_ADD: 787 backbone_addr = hw_src; 788 break; 789 case BATADV_CLAIM_TYPE_REQUEST: 790 case BATADV_CLAIM_TYPE_ANNOUNCE: 791 case BATADV_CLAIM_TYPE_DEL: 792 backbone_addr = ethhdr->h_source; 793 break; 794 default: 795 return 0; 796 } 797 798 /* don't accept claim frames from ourselves */ 799 if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) 800 return 0; 801 802 /* if its already the same group, it is fine. */ 803 if (bla_dst->group == bla_dst_own->group) 804 return 2; 805 806 /* lets see if this originator is in our mesh */ 807 orig_node = batadv_orig_hash_find(bat_priv, backbone_addr); 808 809 /* dont accept claims from gateways which are not in 810 * the same mesh or group. 811 */ 812 if (!orig_node) 813 return 1; 814 815 /* if our mesh friends mac is bigger, use it for ourselves. */ 816 if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) { 817 batadv_dbg(BATADV_DBG_BLA, bat_priv, 818 "taking other backbones claim group: %04x\n", 819 ntohs(bla_dst->group)); 820 bla_dst_own->group = bla_dst->group; 821 } 822 823 batadv_orig_node_free_ref(orig_node); 824 825 return 2; 826 } 827 828 829 /* @bat_priv: the bat priv with all the soft interface information 830 * @skb: the frame to be checked 831 * 832 * Check if this is a claim frame, and process it accordingly. 833 * 834 * returns 1 if it was a claim frame, otherwise return 0 to 835 * tell the callee that it can use the frame on its own. 836 */ 837 static int batadv_bla_process_claim(struct batadv_priv *bat_priv, 838 struct batadv_hard_iface *primary_if, 839 struct sk_buff *skb) 840 { 841 struct ethhdr *ethhdr; 842 struct vlan_ethhdr *vhdr; 843 struct arphdr *arphdr; 844 uint8_t *hw_src, *hw_dst; 845 struct batadv_bla_claim_dst *bla_dst; 846 uint16_t proto; 847 int headlen; 848 short vid = -1; 849 int ret; 850 851 ethhdr = (struct ethhdr *)skb_mac_header(skb); 852 853 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) { 854 vhdr = (struct vlan_ethhdr *)ethhdr; 855 vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK; 856 proto = ntohs(vhdr->h_vlan_encapsulated_proto); 857 headlen = sizeof(*vhdr); 858 } else { 859 proto = ntohs(ethhdr->h_proto); 860 headlen = ETH_HLEN; 861 } 862 863 if (proto != ETH_P_ARP) 864 return 0; /* not a claim frame */ 865 866 /* this must be a ARP frame. check if it is a claim. */ 867 868 if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev)))) 869 return 0; 870 871 /* pskb_may_pull() may have modified the pointers, get ethhdr again */ 872 ethhdr = (struct ethhdr *)skb_mac_header(skb); 873 arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen); 874 875 /* Check whether the ARP frame carries a valid 876 * IP information 877 */ 878 if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) 879 return 0; 880 if (arphdr->ar_pro != htons(ETH_P_IP)) 881 return 0; 882 if (arphdr->ar_hln != ETH_ALEN) 883 return 0; 884 if (arphdr->ar_pln != 4) 885 return 0; 886 887 hw_src = (uint8_t *)arphdr + sizeof(struct arphdr); 888 hw_dst = hw_src + ETH_ALEN + 4; 889 bla_dst = (struct batadv_bla_claim_dst *)hw_dst; 890 891 /* check if it is a claim frame. */ 892 ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst, 893 ethhdr); 894 if (ret == 1) 895 batadv_dbg(BATADV_DBG_BLA, bat_priv, 896 "bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n", 897 ethhdr->h_source, vid, hw_src, hw_dst); 898 899 if (ret < 2) 900 return ret; 901 902 /* become a backbone gw ourselves on this vlan if not happened yet */ 903 batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); 904 905 /* check for the different types of claim frames ... */ 906 switch (bla_dst->type) { 907 case BATADV_CLAIM_TYPE_ADD: 908 if (batadv_handle_claim(bat_priv, primary_if, hw_src, 909 ethhdr->h_source, vid)) 910 return 1; 911 break; 912 case BATADV_CLAIM_TYPE_DEL: 913 if (batadv_handle_unclaim(bat_priv, primary_if, 914 ethhdr->h_source, hw_src, vid)) 915 return 1; 916 break; 917 918 case BATADV_CLAIM_TYPE_ANNOUNCE: 919 if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source, 920 vid)) 921 return 1; 922 break; 923 case BATADV_CLAIM_TYPE_REQUEST: 924 if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr, 925 vid)) 926 return 1; 927 break; 928 } 929 930 batadv_dbg(BATADV_DBG_BLA, bat_priv, 931 "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", 932 ethhdr->h_source, vid, hw_src, hw_dst); 933 return 1; 934 } 935 936 /* Check when we last heard from other nodes, and remove them in case of 937 * a time out, or clean all backbone gws if now is set. 938 */ 939 static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now) 940 { 941 struct batadv_backbone_gw *backbone_gw; 942 struct hlist_node *node, *node_tmp; 943 struct hlist_head *head; 944 struct batadv_hashtable *hash; 945 spinlock_t *list_lock; /* protects write access to the hash lists */ 946 int i; 947 948 hash = bat_priv->backbone_hash; 949 if (!hash) 950 return; 951 952 for (i = 0; i < hash->size; i++) { 953 head = &hash->table[i]; 954 list_lock = &hash->list_locks[i]; 955 956 spin_lock_bh(list_lock); 957 hlist_for_each_entry_safe(backbone_gw, node, node_tmp, 958 head, hash_entry) { 959 if (now) 960 goto purge_now; 961 if (!batadv_has_timed_out(backbone_gw->lasttime, 962 BATADV_BLA_BACKBONE_TIMEOUT)) 963 continue; 964 965 batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, 966 "bla_purge_backbone_gw(): backbone gw %pM timed out\n", 967 backbone_gw->orig); 968 969 purge_now: 970 /* don't wait for the pending request anymore */ 971 if (atomic_read(&backbone_gw->request_sent)) 972 atomic_dec(&bat_priv->bla_num_requests); 973 974 batadv_bla_del_backbone_claims(backbone_gw); 975 976 hlist_del_rcu(node); 977 batadv_backbone_gw_free_ref(backbone_gw); 978 } 979 spin_unlock_bh(list_lock); 980 } 981 } 982 983 /** 984 * batadv_bla_purge_claims 985 * @bat_priv: the bat priv with all the soft interface information 986 * @primary_if: the selected primary interface, may be NULL if now is set 987 * @now: whether the whole hash shall be wiped now 988 * 989 * Check when we heard last time from our own claims, and remove them in case of 990 * a time out, or clean all claims if now is set 991 */ 992 static void batadv_bla_purge_claims(struct batadv_priv *bat_priv, 993 struct batadv_hard_iface *primary_if, 994 int now) 995 { 996 struct batadv_claim *claim; 997 struct hlist_node *node; 998 struct hlist_head *head; 999 struct batadv_hashtable *hash; 1000 int i; 1001 1002 hash = bat_priv->claim_hash; 1003 if (!hash) 1004 return; 1005 1006 for (i = 0; i < hash->size; i++) { 1007 head = &hash->table[i]; 1008 1009 rcu_read_lock(); 1010 hlist_for_each_entry_rcu(claim, node, head, hash_entry) { 1011 if (now) 1012 goto purge_now; 1013 if (!batadv_compare_eth(claim->backbone_gw->orig, 1014 primary_if->net_dev->dev_addr)) 1015 continue; 1016 if (!batadv_has_timed_out(claim->lasttime, 1017 BATADV_BLA_CLAIM_TIMEOUT)) 1018 continue; 1019 1020 batadv_dbg(BATADV_DBG_BLA, bat_priv, 1021 "bla_purge_claims(): %pM, vid %d, time out\n", 1022 claim->addr, claim->vid); 1023 1024 purge_now: 1025 batadv_handle_unclaim(bat_priv, primary_if, 1026 claim->backbone_gw->orig, 1027 claim->addr, claim->vid); 1028 } 1029 rcu_read_unlock(); 1030 } 1031 } 1032 1033 /** 1034 * batadv_bla_update_orig_address 1035 * @bat_priv: the bat priv with all the soft interface information 1036 * @primary_if: the new selected primary_if 1037 * @oldif: the old primary interface, may be NULL 1038 * 1039 * Update the backbone gateways when the own orig address changes. 1040 */ 1041 void batadv_bla_update_orig_address(struct batadv_priv *bat_priv, 1042 struct batadv_hard_iface *primary_if, 1043 struct batadv_hard_iface *oldif) 1044 { 1045 struct batadv_backbone_gw *backbone_gw; 1046 struct hlist_node *node; 1047 struct hlist_head *head; 1048 struct batadv_hashtable *hash; 1049 int i; 1050 1051 /* reset bridge loop avoidance group id */ 1052 bat_priv->claim_dest.group = 1053 htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN)); 1054 1055 if (!oldif) { 1056 batadv_bla_purge_claims(bat_priv, NULL, 1); 1057 batadv_bla_purge_backbone_gw(bat_priv, 1); 1058 return; 1059 } 1060 1061 hash = bat_priv->backbone_hash; 1062 if (!hash) 1063 return; 1064 1065 for (i = 0; i < hash->size; i++) { 1066 head = &hash->table[i]; 1067 1068 rcu_read_lock(); 1069 hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) { 1070 /* own orig still holds the old value. */ 1071 if (!batadv_compare_eth(backbone_gw->orig, 1072 oldif->net_dev->dev_addr)) 1073 continue; 1074 1075 memcpy(backbone_gw->orig, 1076 primary_if->net_dev->dev_addr, ETH_ALEN); 1077 /* send an announce frame so others will ask for our 1078 * claims and update their tables. 1079 */ 1080 batadv_bla_send_announce(bat_priv, backbone_gw); 1081 } 1082 rcu_read_unlock(); 1083 } 1084 } 1085 1086 1087 1088 /* (re)start the timer */ 1089 static void batadv_bla_start_timer(struct batadv_priv *bat_priv) 1090 { 1091 INIT_DELAYED_WORK(&bat_priv->bla_work, batadv_bla_periodic_work); 1092 queue_delayed_work(batadv_event_workqueue, &bat_priv->bla_work, 1093 msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH)); 1094 } 1095 1096 /* periodic work to do: 1097 * * purge structures when they are too old 1098 * * send announcements 1099 */ 1100 static void batadv_bla_periodic_work(struct work_struct *work) 1101 { 1102 struct delayed_work *delayed_work = 1103 container_of(work, struct delayed_work, work); 1104 struct batadv_priv *bat_priv; 1105 struct hlist_node *node; 1106 struct hlist_head *head; 1107 struct batadv_backbone_gw *backbone_gw; 1108 struct batadv_hashtable *hash; 1109 struct batadv_hard_iface *primary_if; 1110 int i; 1111 1112 bat_priv = container_of(delayed_work, struct batadv_priv, bla_work); 1113 primary_if = batadv_primary_if_get_selected(bat_priv); 1114 if (!primary_if) 1115 goto out; 1116 1117 batadv_bla_purge_claims(bat_priv, primary_if, 0); 1118 batadv_bla_purge_backbone_gw(bat_priv, 0); 1119 1120 if (!atomic_read(&bat_priv->bridge_loop_avoidance)) 1121 goto out; 1122 1123 hash = bat_priv->backbone_hash; 1124 if (!hash) 1125 goto out; 1126 1127 for (i = 0; i < hash->size; i++) { 1128 head = &hash->table[i]; 1129 1130 rcu_read_lock(); 1131 hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) { 1132 if (!batadv_compare_eth(backbone_gw->orig, 1133 primary_if->net_dev->dev_addr)) 1134 continue; 1135 1136 backbone_gw->lasttime = jiffies; 1137 1138 batadv_bla_send_announce(bat_priv, backbone_gw); 1139 } 1140 rcu_read_unlock(); 1141 } 1142 out: 1143 if (primary_if) 1144 batadv_hardif_free_ref(primary_if); 1145 1146 batadv_bla_start_timer(bat_priv); 1147 } 1148 1149 /* The hash for claim and backbone hash receive the same key because they 1150 * are getting initialized by hash_new with the same key. Reinitializing 1151 * them with to different keys to allow nested locking without generating 1152 * lockdep warnings 1153 */ 1154 static struct lock_class_key batadv_claim_hash_lock_class_key; 1155 static struct lock_class_key batadv_backbone_hash_lock_class_key; 1156 1157 /* initialize all bla structures */ 1158 int batadv_bla_init(struct batadv_priv *bat_priv) 1159 { 1160 int i; 1161 uint8_t claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00}; 1162 struct batadv_hard_iface *primary_if; 1163 1164 batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n"); 1165 1166 /* setting claim destination address */ 1167 memcpy(&bat_priv->claim_dest.magic, claim_dest, 3); 1168 bat_priv->claim_dest.type = 0; 1169 primary_if = batadv_primary_if_get_selected(bat_priv); 1170 if (primary_if) { 1171 bat_priv->claim_dest.group = 1172 htons(crc16(0, primary_if->net_dev->dev_addr, 1173 ETH_ALEN)); 1174 batadv_hardif_free_ref(primary_if); 1175 } else { 1176 bat_priv->claim_dest.group = 0; /* will be set later */ 1177 } 1178 1179 /* initialize the duplicate list */ 1180 for (i = 0; i < BATADV_DUPLIST_SIZE; i++) 1181 bat_priv->bcast_duplist[i].entrytime = 1182 jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT); 1183 bat_priv->bcast_duplist_curr = 0; 1184 1185 if (bat_priv->claim_hash) 1186 return 0; 1187 1188 bat_priv->claim_hash = batadv_hash_new(128); 1189 bat_priv->backbone_hash = batadv_hash_new(32); 1190 1191 if (!bat_priv->claim_hash || !bat_priv->backbone_hash) 1192 return -ENOMEM; 1193 1194 batadv_hash_set_lock_class(bat_priv->claim_hash, 1195 &batadv_claim_hash_lock_class_key); 1196 batadv_hash_set_lock_class(bat_priv->backbone_hash, 1197 &batadv_backbone_hash_lock_class_key); 1198 1199 batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n"); 1200 1201 batadv_bla_start_timer(bat_priv); 1202 return 0; 1203 } 1204 1205 /** 1206 * batadv_bla_check_bcast_duplist 1207 * @bat_priv: the bat priv with all the soft interface information 1208 * @bcast_packet: originator mac address 1209 * @hdr_size: maximum length of the frame 1210 * 1211 * check if it is on our broadcast list. Another gateway might 1212 * have sent the same packet because it is connected to the same backbone, 1213 * so we have to remove this duplicate. 1214 * 1215 * This is performed by checking the CRC, which will tell us 1216 * with a good chance that it is the same packet. If it is furthermore 1217 * sent by another host, drop it. We allow equal packets from 1218 * the same host however as this might be intended. 1219 */ 1220 int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, 1221 struct batadv_bcast_packet *bcast_packet, 1222 int hdr_size) 1223 { 1224 int i, length, curr; 1225 uint8_t *content; 1226 uint16_t crc; 1227 struct batadv_bcast_duplist_entry *entry; 1228 1229 length = hdr_size - sizeof(*bcast_packet); 1230 content = (uint8_t *)bcast_packet; 1231 content += sizeof(*bcast_packet); 1232 1233 /* calculate the crc ... */ 1234 crc = crc16(0, content, length); 1235 1236 for (i = 0; i < BATADV_DUPLIST_SIZE; i++) { 1237 curr = (bat_priv->bcast_duplist_curr + i) % BATADV_DUPLIST_SIZE; 1238 entry = &bat_priv->bcast_duplist[curr]; 1239 1240 /* we can stop searching if the entry is too old ; 1241 * later entries will be even older 1242 */ 1243 if (batadv_has_timed_out(entry->entrytime, 1244 BATADV_DUPLIST_TIMEOUT)) 1245 break; 1246 1247 if (entry->crc != crc) 1248 continue; 1249 1250 if (batadv_compare_eth(entry->orig, bcast_packet->orig)) 1251 continue; 1252 1253 /* this entry seems to match: same crc, not too old, 1254 * and from another gw. therefore return 1 to forbid it. 1255 */ 1256 return 1; 1257 } 1258 /* not found, add a new entry (overwrite the oldest entry) */ 1259 curr = (bat_priv->bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1); 1260 curr %= BATADV_DUPLIST_SIZE; 1261 entry = &bat_priv->bcast_duplist[curr]; 1262 entry->crc = crc; 1263 entry->entrytime = jiffies; 1264 memcpy(entry->orig, bcast_packet->orig, ETH_ALEN); 1265 bat_priv->bcast_duplist_curr = curr; 1266 1267 /* allow it, its the first occurence. */ 1268 return 0; 1269 } 1270 1271 1272 1273 /* @bat_priv: the bat priv with all the soft interface information 1274 * @orig: originator mac address 1275 * 1276 * check if the originator is a gateway for any VLAN ID. 1277 * 1278 * returns 1 if it is found, 0 otherwise 1279 */ 1280 int batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, uint8_t *orig) 1281 { 1282 struct batadv_hashtable *hash = bat_priv->backbone_hash; 1283 struct hlist_head *head; 1284 struct hlist_node *node; 1285 struct batadv_backbone_gw *backbone_gw; 1286 int i; 1287 1288 if (!atomic_read(&bat_priv->bridge_loop_avoidance)) 1289 return 0; 1290 1291 if (!hash) 1292 return 0; 1293 1294 for (i = 0; i < hash->size; i++) { 1295 head = &hash->table[i]; 1296 1297 rcu_read_lock(); 1298 hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) { 1299 if (batadv_compare_eth(backbone_gw->orig, orig)) { 1300 rcu_read_unlock(); 1301 return 1; 1302 } 1303 } 1304 rcu_read_unlock(); 1305 } 1306 1307 return 0; 1308 } 1309 1310 1311 /** 1312 * batadv_bla_is_backbone_gw 1313 * @skb: the frame to be checked 1314 * @orig_node: the orig_node of the frame 1315 * @hdr_size: maximum length of the frame 1316 * 1317 * bla_is_backbone_gw inspects the skb for the VLAN ID and returns 1 1318 * if the orig_node is also a gateway on the soft interface, otherwise it 1319 * returns 0. 1320 */ 1321 int batadv_bla_is_backbone_gw(struct sk_buff *skb, 1322 struct batadv_orig_node *orig_node, int hdr_size) 1323 { 1324 struct ethhdr *ethhdr; 1325 struct vlan_ethhdr *vhdr; 1326 struct batadv_backbone_gw *backbone_gw; 1327 short vid = -1; 1328 1329 if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance)) 1330 return 0; 1331 1332 /* first, find out the vid. */ 1333 if (!pskb_may_pull(skb, hdr_size + ETH_HLEN)) 1334 return 0; 1335 1336 ethhdr = (struct ethhdr *)(((uint8_t *)skb->data) + hdr_size); 1337 1338 if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) { 1339 if (!pskb_may_pull(skb, hdr_size + sizeof(struct vlan_ethhdr))) 1340 return 0; 1341 1342 vhdr = (struct vlan_ethhdr *)(((uint8_t *)skb->data) + 1343 hdr_size); 1344 vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK; 1345 } 1346 1347 /* see if this originator is a backbone gw for this VLAN */ 1348 backbone_gw = batadv_backbone_hash_find(orig_node->bat_priv, 1349 orig_node->orig, vid); 1350 if (!backbone_gw) 1351 return 0; 1352 1353 batadv_backbone_gw_free_ref(backbone_gw); 1354 return 1; 1355 } 1356 1357 /* free all bla structures (for softinterface free or module unload) */ 1358 void batadv_bla_free(struct batadv_priv *bat_priv) 1359 { 1360 struct batadv_hard_iface *primary_if; 1361 1362 cancel_delayed_work_sync(&bat_priv->bla_work); 1363 primary_if = batadv_primary_if_get_selected(bat_priv); 1364 1365 if (bat_priv->claim_hash) { 1366 batadv_bla_purge_claims(bat_priv, primary_if, 1); 1367 batadv_hash_destroy(bat_priv->claim_hash); 1368 bat_priv->claim_hash = NULL; 1369 } 1370 if (bat_priv->backbone_hash) { 1371 batadv_bla_purge_backbone_gw(bat_priv, 1); 1372 batadv_hash_destroy(bat_priv->backbone_hash); 1373 bat_priv->backbone_hash = NULL; 1374 } 1375 if (primary_if) 1376 batadv_hardif_free_ref(primary_if); 1377 } 1378 1379 /** 1380 * batadv_bla_rx 1381 * @bat_priv: the bat priv with all the soft interface information 1382 * @skb: the frame to be checked 1383 * @vid: the VLAN ID of the frame 1384 * @is_bcast: the packet came in a broadcast packet type. 1385 * 1386 * bla_rx avoidance checks if: 1387 * * we have to race for a claim 1388 * * if the frame is allowed on the LAN 1389 * 1390 * in these cases, the skb is further handled by this function and 1391 * returns 1, otherwise it returns 0 and the caller shall further 1392 * process the skb. 1393 */ 1394 int batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid, 1395 bool is_bcast) 1396 { 1397 struct ethhdr *ethhdr; 1398 struct batadv_claim search_claim, *claim = NULL; 1399 struct batadv_hard_iface *primary_if; 1400 int ret; 1401 1402 ethhdr = (struct ethhdr *)skb_mac_header(skb); 1403 1404 primary_if = batadv_primary_if_get_selected(bat_priv); 1405 if (!primary_if) 1406 goto handled; 1407 1408 if (!atomic_read(&bat_priv->bridge_loop_avoidance)) 1409 goto allow; 1410 1411 1412 if (unlikely(atomic_read(&bat_priv->bla_num_requests))) 1413 /* don't allow broadcasts while requests are in flight */ 1414 if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) 1415 goto handled; 1416 1417 memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN); 1418 search_claim.vid = vid; 1419 claim = batadv_claim_hash_find(bat_priv, &search_claim); 1420 1421 if (!claim) { 1422 /* possible optimization: race for a claim */ 1423 /* No claim exists yet, claim it for us! 1424 */ 1425 batadv_handle_claim(bat_priv, primary_if, 1426 primary_if->net_dev->dev_addr, 1427 ethhdr->h_source, vid); 1428 goto allow; 1429 } 1430 1431 /* if it is our own claim ... */ 1432 if (batadv_compare_eth(claim->backbone_gw->orig, 1433 primary_if->net_dev->dev_addr)) { 1434 /* ... allow it in any case */ 1435 claim->lasttime = jiffies; 1436 goto allow; 1437 } 1438 1439 /* if it is a broadcast ... */ 1440 if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) { 1441 /* ... drop it. the responsible gateway is in charge. 1442 * 1443 * We need to check is_bcast because with the gateway 1444 * feature, broadcasts (like DHCP requests) may be sent 1445 * using a unicast packet type. 1446 */ 1447 goto handled; 1448 } else { 1449 /* seems the client considers us as its best gateway. 1450 * send a claim and update the claim table 1451 * immediately. 1452 */ 1453 batadv_handle_claim(bat_priv, primary_if, 1454 primary_if->net_dev->dev_addr, 1455 ethhdr->h_source, vid); 1456 goto allow; 1457 } 1458 allow: 1459 batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); 1460 ret = 0; 1461 goto out; 1462 1463 handled: 1464 kfree_skb(skb); 1465 ret = 1; 1466 1467 out: 1468 if (primary_if) 1469 batadv_hardif_free_ref(primary_if); 1470 if (claim) 1471 batadv_claim_free_ref(claim); 1472 return ret; 1473 } 1474 1475 /** 1476 * batadv_bla_tx 1477 * @bat_priv: the bat priv with all the soft interface information 1478 * @skb: the frame to be checked 1479 * @vid: the VLAN ID of the frame 1480 * 1481 * bla_tx checks if: 1482 * * a claim was received which has to be processed 1483 * * the frame is allowed on the mesh 1484 * 1485 * in these cases, the skb is further handled by this function and 1486 * returns 1, otherwise it returns 0 and the caller shall further 1487 * process the skb. 1488 */ 1489 int batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid) 1490 { 1491 struct ethhdr *ethhdr; 1492 struct batadv_claim search_claim, *claim = NULL; 1493 struct batadv_hard_iface *primary_if; 1494 int ret = 0; 1495 1496 primary_if = batadv_primary_if_get_selected(bat_priv); 1497 if (!primary_if) 1498 goto out; 1499 1500 if (!atomic_read(&bat_priv->bridge_loop_avoidance)) 1501 goto allow; 1502 1503 /* in VLAN case, the mac header might not be set. */ 1504 skb_reset_mac_header(skb); 1505 1506 if (batadv_bla_process_claim(bat_priv, primary_if, skb)) 1507 goto handled; 1508 1509 ethhdr = (struct ethhdr *)skb_mac_header(skb); 1510 1511 if (unlikely(atomic_read(&bat_priv->bla_num_requests))) 1512 /* don't allow broadcasts while requests are in flight */ 1513 if (is_multicast_ether_addr(ethhdr->h_dest)) 1514 goto handled; 1515 1516 memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN); 1517 search_claim.vid = vid; 1518 1519 claim = batadv_claim_hash_find(bat_priv, &search_claim); 1520 1521 /* if no claim exists, allow it. */ 1522 if (!claim) 1523 goto allow; 1524 1525 /* check if we are responsible. */ 1526 if (batadv_compare_eth(claim->backbone_gw->orig, 1527 primary_if->net_dev->dev_addr)) { 1528 /* if yes, the client has roamed and we have 1529 * to unclaim it. 1530 */ 1531 batadv_handle_unclaim(bat_priv, primary_if, 1532 primary_if->net_dev->dev_addr, 1533 ethhdr->h_source, vid); 1534 goto allow; 1535 } 1536 1537 /* check if it is a multicast/broadcast frame */ 1538 if (is_multicast_ether_addr(ethhdr->h_dest)) { 1539 /* drop it. the responsible gateway has forwarded it into 1540 * the backbone network. 1541 */ 1542 goto handled; 1543 } else { 1544 /* we must allow it. at least if we are 1545 * responsible for the DESTINATION. 1546 */ 1547 goto allow; 1548 } 1549 allow: 1550 batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); 1551 ret = 0; 1552 goto out; 1553 handled: 1554 ret = 1; 1555 out: 1556 if (primary_if) 1557 batadv_hardif_free_ref(primary_if); 1558 if (claim) 1559 batadv_claim_free_ref(claim); 1560 return ret; 1561 } 1562 1563 int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset) 1564 { 1565 struct net_device *net_dev = (struct net_device *)seq->private; 1566 struct batadv_priv *bat_priv = netdev_priv(net_dev); 1567 struct batadv_hashtable *hash = bat_priv->claim_hash; 1568 struct batadv_claim *claim; 1569 struct batadv_hard_iface *primary_if; 1570 struct hlist_node *node; 1571 struct hlist_head *head; 1572 uint32_t i; 1573 bool is_own; 1574 int ret = 0; 1575 uint8_t *primary_addr; 1576 1577 primary_if = batadv_primary_if_get_selected(bat_priv); 1578 if (!primary_if) { 1579 ret = seq_printf(seq, 1580 "BATMAN mesh %s disabled - please specify interfaces to enable it\n", 1581 net_dev->name); 1582 goto out; 1583 } 1584 1585 if (primary_if->if_status != BATADV_IF_ACTIVE) { 1586 ret = seq_printf(seq, 1587 "BATMAN mesh %s disabled - primary interface not active\n", 1588 net_dev->name); 1589 goto out; 1590 } 1591 1592 primary_addr = primary_if->net_dev->dev_addr; 1593 seq_printf(seq, 1594 "Claims announced for the mesh %s (orig %pM, group id %04x)\n", 1595 net_dev->name, primary_addr, 1596 ntohs(bat_priv->claim_dest.group)); 1597 seq_printf(seq, " %-17s %-5s %-17s [o] (%-4s)\n", 1598 "Client", "VID", "Originator", "CRC"); 1599 for (i = 0; i < hash->size; i++) { 1600 head = &hash->table[i]; 1601 1602 rcu_read_lock(); 1603 hlist_for_each_entry_rcu(claim, node, head, hash_entry) { 1604 is_own = batadv_compare_eth(claim->backbone_gw->orig, 1605 primary_addr); 1606 seq_printf(seq, " * %pM on % 5d by %pM [%c] (%04x)\n", 1607 claim->addr, claim->vid, 1608 claim->backbone_gw->orig, 1609 (is_own ? 'x' : ' '), 1610 claim->backbone_gw->crc); 1611 } 1612 rcu_read_unlock(); 1613 } 1614 out: 1615 if (primary_if) 1616 batadv_hardif_free_ref(primary_if); 1617 return ret; 1618 } 1619