Simon Wunderlich | 2372138 | 2012-01-22 20:00:19 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2011 B.A.T.M.A.N. contributors: |
| 3 | * |
| 4 | * Simon Wunderlich |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of version 2 of the GNU General Public |
| 8 | * License as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 18 | * 02110-1301, USA |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include "main.h" |
| 23 | #include "hash.h" |
| 24 | #include "hard-interface.h" |
| 25 | #include "originator.h" |
| 26 | #include "bridge_loop_avoidance.h" |
| 27 | #include "send.h" |
| 28 | |
| 29 | #include <linux/etherdevice.h> |
| 30 | #include <linux/crc16.h> |
| 31 | #include <linux/if_arp.h> |
| 32 | #include <net/arp.h> |
| 33 | #include <linux/if_vlan.h> |
| 34 | |
| 35 | static const uint8_t claim_dest[6] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00}; |
| 36 | static const uint8_t announce_mac[4] = {0x43, 0x05, 0x43, 0x05}; |
| 37 | |
| 38 | static void bla_periodic_work(struct work_struct *work); |
| 39 | static void bla_send_announce(struct bat_priv *bat_priv, |
| 40 | struct backbone_gw *backbone_gw); |
| 41 | |
| 42 | /* return the index of the claim */ |
| 43 | static inline uint32_t choose_claim(const void *data, uint32_t size) |
| 44 | { |
| 45 | const unsigned char *key = data; |
| 46 | uint32_t hash = 0; |
| 47 | size_t i; |
| 48 | |
| 49 | for (i = 0; i < ETH_ALEN + sizeof(short); i++) { |
| 50 | hash += key[i]; |
| 51 | hash += (hash << 10); |
| 52 | hash ^= (hash >> 6); |
| 53 | } |
| 54 | |
| 55 | hash += (hash << 3); |
| 56 | hash ^= (hash >> 11); |
| 57 | hash += (hash << 15); |
| 58 | |
| 59 | return hash % size; |
| 60 | } |
| 61 | |
| 62 | /* return the index of the backbone gateway */ |
| 63 | static inline uint32_t choose_backbone_gw(const void *data, uint32_t size) |
| 64 | { |
| 65 | const unsigned char *key = data; |
| 66 | uint32_t hash = 0; |
| 67 | size_t i; |
| 68 | |
| 69 | for (i = 0; i < ETH_ALEN + sizeof(short); i++) { |
| 70 | hash += key[i]; |
| 71 | hash += (hash << 10); |
| 72 | hash ^= (hash >> 6); |
| 73 | } |
| 74 | |
| 75 | hash += (hash << 3); |
| 76 | hash ^= (hash >> 11); |
| 77 | hash += (hash << 15); |
| 78 | |
| 79 | return hash % size; |
| 80 | } |
| 81 | |
| 82 | |
| 83 | /* compares address and vid of two backbone gws */ |
| 84 | static int compare_backbone_gw(const struct hlist_node *node, const void *data2) |
| 85 | { |
| 86 | const void *data1 = container_of(node, struct 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 compare_claim(const struct hlist_node *node, const void *data2) |
| 94 | { |
| 95 | const void *data1 = container_of(node, struct claim, |
| 96 | hash_entry); |
| 97 | |
| 98 | return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0); |
| 99 | } |
| 100 | |
| 101 | /* free a backbone gw */ |
| 102 | static void backbone_gw_free_ref(struct backbone_gw *backbone_gw) |
| 103 | { |
| 104 | if (atomic_dec_and_test(&backbone_gw->refcount)) |
| 105 | kfree_rcu(backbone_gw, rcu); |
| 106 | } |
| 107 | |
| 108 | /* finally deinitialize the claim */ |
| 109 | static void claim_free_rcu(struct rcu_head *rcu) |
| 110 | { |
| 111 | struct claim *claim; |
| 112 | |
| 113 | claim = container_of(rcu, struct claim, rcu); |
| 114 | |
| 115 | backbone_gw_free_ref(claim->backbone_gw); |
| 116 | kfree(claim); |
| 117 | } |
| 118 | |
| 119 | /* free a claim, call claim_free_rcu if its the last reference */ |
| 120 | static void claim_free_ref(struct claim *claim) |
| 121 | { |
| 122 | if (atomic_dec_and_test(&claim->refcount)) |
| 123 | call_rcu(&claim->rcu, claim_free_rcu); |
| 124 | } |
| 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 claim *claim_hash_find(struct bat_priv *bat_priv, |
| 134 | struct claim *data) |
| 135 | { |
| 136 | struct hashtable_t *hash = bat_priv->claim_hash; |
| 137 | struct hlist_head *head; |
| 138 | struct hlist_node *node; |
| 139 | struct claim *claim; |
| 140 | struct claim *claim_tmp = NULL; |
| 141 | int index; |
| 142 | |
| 143 | if (!hash) |
| 144 | return NULL; |
| 145 | |
| 146 | index = 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 (!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 | * @bat_priv: the bat priv with all the soft interface information |
| 167 | * @addr: the address of the originator |
| 168 | * @vid: the VLAN ID |
| 169 | * |
| 170 | * looks for a claim in the hash, and returns it if found |
| 171 | * or NULL otherwise. |
| 172 | */ |
| 173 | static struct backbone_gw *backbone_hash_find(struct bat_priv *bat_priv, |
| 174 | uint8_t *addr, short vid) |
| 175 | { |
| 176 | struct hashtable_t *hash = bat_priv->backbone_hash; |
| 177 | struct hlist_head *head; |
| 178 | struct hlist_node *node; |
| 179 | struct backbone_gw search_entry, *backbone_gw; |
| 180 | struct backbone_gw *backbone_gw_tmp = NULL; |
| 181 | int index; |
| 182 | |
| 183 | if (!hash) |
| 184 | return NULL; |
| 185 | |
| 186 | memcpy(search_entry.orig, addr, ETH_ALEN); |
| 187 | search_entry.vid = vid; |
| 188 | |
| 189 | index = choose_backbone_gw(&search_entry, hash->size); |
| 190 | head = &hash->table[index]; |
| 191 | |
| 192 | rcu_read_lock(); |
| 193 | hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) { |
| 194 | if (!compare_backbone_gw(&backbone_gw->hash_entry, |
| 195 | &search_entry)) |
| 196 | continue; |
| 197 | |
| 198 | if (!atomic_inc_not_zero(&backbone_gw->refcount)) |
| 199 | continue; |
| 200 | |
| 201 | backbone_gw_tmp = backbone_gw; |
| 202 | break; |
| 203 | } |
| 204 | rcu_read_unlock(); |
| 205 | |
| 206 | return backbone_gw_tmp; |
| 207 | } |
| 208 | |
| 209 | /* delete all claims for a backbone */ |
| 210 | static void bla_del_backbone_claims(struct backbone_gw *backbone_gw) |
| 211 | { |
| 212 | struct hashtable_t *hash; |
| 213 | struct hlist_node *node, *node_tmp; |
| 214 | struct hlist_head *head; |
| 215 | struct claim *claim; |
| 216 | int i; |
| 217 | spinlock_t *list_lock; /* protects write access to the hash lists */ |
| 218 | |
| 219 | hash = backbone_gw->bat_priv->claim_hash; |
| 220 | if (!hash) |
| 221 | return; |
| 222 | |
| 223 | for (i = 0; i < hash->size; i++) { |
| 224 | head = &hash->table[i]; |
| 225 | list_lock = &hash->list_locks[i]; |
| 226 | |
| 227 | spin_lock_bh(list_lock); |
| 228 | hlist_for_each_entry_safe(claim, node, node_tmp, |
| 229 | head, hash_entry) { |
| 230 | |
| 231 | if (claim->backbone_gw != backbone_gw) |
| 232 | continue; |
| 233 | |
| 234 | claim_free_ref(claim); |
| 235 | hlist_del_rcu(node); |
| 236 | } |
| 237 | spin_unlock_bh(list_lock); |
| 238 | } |
| 239 | |
| 240 | /* all claims gone, intialize CRC */ |
| 241 | backbone_gw->crc = BLA_CRC_INIT; |
| 242 | } |
| 243 | |
| 244 | /** |
| 245 | * @bat_priv: the bat priv with all the soft interface information |
| 246 | * @orig: the mac address to be announced within the claim |
| 247 | * @vid: the VLAN ID |
| 248 | * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...) |
| 249 | * |
| 250 | * sends a claim frame according to the provided info. |
| 251 | */ |
| 252 | static void bla_send_claim(struct bat_priv *bat_priv, uint8_t *mac, |
| 253 | short vid, int claimtype) |
| 254 | { |
| 255 | struct sk_buff *skb; |
| 256 | struct ethhdr *ethhdr; |
| 257 | struct hard_iface *primary_if; |
| 258 | struct net_device *soft_iface; |
| 259 | uint8_t *hw_src; |
| 260 | struct bla_claim_dst local_claim_dest; |
| 261 | uint32_t zeroip = 0; |
| 262 | |
| 263 | primary_if = primary_if_get_selected(bat_priv); |
| 264 | if (!primary_if) |
| 265 | return; |
| 266 | |
| 267 | memcpy(&local_claim_dest, claim_dest, sizeof(local_claim_dest)); |
| 268 | local_claim_dest.type = claimtype; |
| 269 | |
| 270 | soft_iface = primary_if->soft_iface; |
| 271 | |
| 272 | skb = arp_create(ARPOP_REPLY, ETH_P_ARP, |
| 273 | /* IP DST: 0.0.0.0 */ |
| 274 | zeroip, |
| 275 | primary_if->soft_iface, |
| 276 | /* IP SRC: 0.0.0.0 */ |
| 277 | zeroip, |
| 278 | /* Ethernet DST: Broadcast */ |
| 279 | NULL, |
| 280 | /* Ethernet SRC/HW SRC: originator mac */ |
| 281 | primary_if->net_dev->dev_addr, |
| 282 | /* HW DST: FF:43:05:XX:00:00 |
| 283 | * with XX = claim type |
| 284 | */ |
| 285 | (uint8_t *)&local_claim_dest); |
| 286 | |
| 287 | if (!skb) |
| 288 | goto out; |
| 289 | |
| 290 | ethhdr = (struct ethhdr *)skb->data; |
| 291 | hw_src = (uint8_t *)ethhdr + |
| 292 | sizeof(struct ethhdr) + |
| 293 | sizeof(struct arphdr); |
| 294 | |
| 295 | /* now we pretend that the client would have sent this ... */ |
| 296 | switch (claimtype) { |
| 297 | case CLAIM_TYPE_ADD: |
| 298 | /* normal claim frame |
| 299 | * set Ethernet SRC to the clients mac |
| 300 | */ |
| 301 | memcpy(ethhdr->h_source, mac, ETH_ALEN); |
| 302 | bat_dbg(DBG_BLA, bat_priv, |
| 303 | "bla_send_claim(): CLAIM %pM on vid %d\n", mac, vid); |
| 304 | break; |
| 305 | case CLAIM_TYPE_DEL: |
| 306 | /* unclaim frame |
| 307 | * set HW SRC to the clients mac |
| 308 | */ |
| 309 | memcpy(hw_src, mac, ETH_ALEN); |
| 310 | bat_dbg(DBG_BLA, bat_priv, |
| 311 | "bla_send_claim(): UNCLAIM %pM on vid %d\n", mac, vid); |
| 312 | break; |
| 313 | case CLAIM_TYPE_ANNOUNCE: |
| 314 | /* announcement frame |
| 315 | * set HW SRC to the special mac containg the crc |
| 316 | */ |
| 317 | memcpy(hw_src, mac, ETH_ALEN); |
| 318 | bat_dbg(DBG_BLA, bat_priv, |
| 319 | "bla_send_claim(): ANNOUNCE of %pM on vid %d\n", |
| 320 | ethhdr->h_source, vid); |
| 321 | break; |
| 322 | case CLAIM_TYPE_REQUEST: |
| 323 | /* request frame |
| 324 | * set HW SRC to the special mac containg the crc |
| 325 | */ |
| 326 | memcpy(hw_src, mac, ETH_ALEN); |
| 327 | memcpy(ethhdr->h_dest, mac, ETH_ALEN); |
| 328 | bat_dbg(DBG_BLA, bat_priv, |
| 329 | "bla_send_claim(): REQUEST of %pM to %pMon vid %d\n", |
| 330 | ethhdr->h_source, ethhdr->h_dest, vid); |
| 331 | break; |
| 332 | |
| 333 | } |
| 334 | |
| 335 | if (vid != -1) |
| 336 | skb = vlan_insert_tag(skb, vid); |
| 337 | |
| 338 | skb_reset_mac_header(skb); |
| 339 | skb->protocol = eth_type_trans(skb, soft_iface); |
| 340 | bat_priv->stats.rx_packets++; |
| 341 | bat_priv->stats.rx_bytes += skb->len + sizeof(struct ethhdr); |
| 342 | soft_iface->last_rx = jiffies; |
| 343 | |
| 344 | netif_rx(skb); |
| 345 | out: |
| 346 | if (primary_if) |
| 347 | hardif_free_ref(primary_if); |
| 348 | } |
| 349 | |
| 350 | /** |
| 351 | * @bat_priv: the bat priv with all the soft interface information |
| 352 | * @orig: the mac address of the originator |
| 353 | * @vid: the VLAN ID |
| 354 | * |
| 355 | * searches for the backbone gw or creates a new one if it could not |
| 356 | * be found. |
| 357 | */ |
| 358 | static struct backbone_gw *bla_get_backbone_gw(struct bat_priv *bat_priv, |
| 359 | uint8_t *orig, short vid) |
| 360 | { |
| 361 | struct backbone_gw *entry; |
| 362 | int hash_added; |
| 363 | |
| 364 | entry = backbone_hash_find(bat_priv, orig, vid); |
| 365 | |
| 366 | if (entry) |
| 367 | return entry; |
| 368 | |
| 369 | bat_dbg(DBG_BLA, bat_priv, |
| 370 | "bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n", |
| 371 | orig, vid); |
| 372 | |
| 373 | entry = kzalloc(sizeof(*entry), GFP_ATOMIC); |
| 374 | if (!entry) |
| 375 | return NULL; |
| 376 | |
| 377 | entry->vid = vid; |
| 378 | entry->lasttime = jiffies; |
| 379 | entry->crc = BLA_CRC_INIT; |
| 380 | entry->bat_priv = bat_priv; |
| 381 | atomic_set(&entry->request_sent, 0); |
| 382 | memcpy(entry->orig, orig, ETH_ALEN); |
| 383 | |
| 384 | /* one for the hash, one for returning */ |
| 385 | atomic_set(&entry->refcount, 2); |
| 386 | |
| 387 | hash_added = hash_add(bat_priv->backbone_hash, compare_backbone_gw, |
| 388 | choose_backbone_gw, entry, &entry->hash_entry); |
| 389 | |
| 390 | if (unlikely(hash_added != 0)) { |
| 391 | /* hash failed, free the structure */ |
| 392 | kfree(entry); |
| 393 | return NULL; |
| 394 | } |
| 395 | |
| 396 | return entry; |
| 397 | } |
| 398 | |
| 399 | /* update or add the own backbone gw to make sure we announce |
| 400 | * where we receive other backbone gws |
| 401 | */ |
| 402 | static void bla_update_own_backbone_gw(struct bat_priv *bat_priv, |
| 403 | struct hard_iface *primary_if, |
| 404 | short vid) |
| 405 | { |
| 406 | struct backbone_gw *backbone_gw; |
| 407 | |
| 408 | backbone_gw = bla_get_backbone_gw(bat_priv, |
| 409 | primary_if->net_dev->dev_addr, vid); |
| 410 | if (unlikely(!backbone_gw)) |
| 411 | return; |
| 412 | |
| 413 | backbone_gw->lasttime = jiffies; |
| 414 | backbone_gw_free_ref(backbone_gw); |
| 415 | } |
| 416 | |
| 417 | /** |
| 418 | * @bat_priv: the bat priv with all the soft interface information |
| 419 | * @vid: the vid where the request came on |
| 420 | * |
| 421 | * Repeat all of our own claims, and finally send an ANNOUNCE frame |
| 422 | * to allow the requester another check if the CRC is correct now. |
| 423 | */ |
| 424 | static void bla_answer_request(struct bat_priv *bat_priv, |
| 425 | struct hard_iface *primary_if, short vid) |
| 426 | { |
| 427 | struct hlist_node *node; |
| 428 | struct hlist_head *head; |
| 429 | struct hashtable_t *hash; |
| 430 | struct claim *claim; |
| 431 | struct backbone_gw *backbone_gw; |
| 432 | int i; |
| 433 | |
| 434 | bat_dbg(DBG_BLA, bat_priv, |
| 435 | "bla_answer_request(): received a claim request, send all of our own claims again\n"); |
| 436 | |
| 437 | backbone_gw = backbone_hash_find(bat_priv, |
| 438 | primary_if->net_dev->dev_addr, vid); |
| 439 | if (!backbone_gw) |
| 440 | return; |
| 441 | |
| 442 | hash = bat_priv->claim_hash; |
| 443 | for (i = 0; i < hash->size; i++) { |
| 444 | head = &hash->table[i]; |
| 445 | |
| 446 | rcu_read_lock(); |
| 447 | hlist_for_each_entry_rcu(claim, node, head, hash_entry) { |
| 448 | /* only own claims are interesting */ |
| 449 | if (claim->backbone_gw != backbone_gw) |
| 450 | continue; |
| 451 | |
| 452 | bla_send_claim(bat_priv, claim->addr, claim->vid, |
| 453 | CLAIM_TYPE_ADD); |
| 454 | } |
| 455 | rcu_read_unlock(); |
| 456 | } |
| 457 | |
| 458 | /* finally, send an announcement frame */ |
| 459 | bla_send_announce(bat_priv, backbone_gw); |
| 460 | backbone_gw_free_ref(backbone_gw); |
| 461 | } |
| 462 | |
| 463 | /** |
| 464 | * @backbone_gw: the backbone gateway from whom we are out of sync |
| 465 | * |
| 466 | * When the crc is wrong, ask the backbone gateway for a full table update. |
| 467 | * After the request, it will repeat all of his own claims and finally |
| 468 | * send an announcement claim with which we can check again. |
| 469 | */ |
| 470 | static void bla_send_request(struct backbone_gw *backbone_gw) |
| 471 | { |
| 472 | /* first, remove all old entries */ |
| 473 | bla_del_backbone_claims(backbone_gw); |
| 474 | |
| 475 | bat_dbg(DBG_BLA, backbone_gw->bat_priv, |
| 476 | "Sending REQUEST to %pM\n", |
| 477 | backbone_gw->orig); |
| 478 | |
| 479 | /* send request */ |
| 480 | bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig, |
| 481 | backbone_gw->vid, CLAIM_TYPE_REQUEST); |
| 482 | |
| 483 | /* no local broadcasts should be sent or received, for now. */ |
| 484 | if (!atomic_read(&backbone_gw->request_sent)) { |
| 485 | atomic_inc(&backbone_gw->bat_priv->bla_num_requests); |
| 486 | atomic_set(&backbone_gw->request_sent, 1); |
| 487 | } |
| 488 | } |
| 489 | |
| 490 | /** |
| 491 | * @bat_priv: the bat priv with all the soft interface information |
| 492 | * @backbone_gw: our backbone gateway which should be announced |
| 493 | * |
| 494 | * This function sends an announcement. It is called from multiple |
| 495 | * places. |
| 496 | */ |
| 497 | static void bla_send_announce(struct bat_priv *bat_priv, |
| 498 | struct backbone_gw *backbone_gw) |
| 499 | { |
| 500 | uint8_t mac[ETH_ALEN]; |
| 501 | uint16_t crc; |
| 502 | |
| 503 | memcpy(mac, announce_mac, 4); |
| 504 | crc = htons(backbone_gw->crc); |
| 505 | memcpy(&mac[4], (uint8_t *)&crc, 2); |
| 506 | |
| 507 | bla_send_claim(bat_priv, mac, backbone_gw->vid, CLAIM_TYPE_ANNOUNCE); |
| 508 | |
| 509 | } |
| 510 | |
| 511 | /** |
| 512 | * @bat_priv: the bat priv with all the soft interface information |
| 513 | * @mac: the mac address of the claim |
| 514 | * @vid: the VLAN ID of the frame |
| 515 | * @backbone_gw: the backbone gateway which claims it |
| 516 | * |
| 517 | * Adds a claim in the claim hash. |
| 518 | */ |
| 519 | static void bla_add_claim(struct bat_priv *bat_priv, const uint8_t *mac, |
| 520 | const short vid, struct backbone_gw *backbone_gw) |
| 521 | { |
| 522 | struct claim *claim; |
| 523 | struct claim search_claim; |
| 524 | int hash_added; |
| 525 | |
| 526 | memcpy(search_claim.addr, mac, ETH_ALEN); |
| 527 | search_claim.vid = vid; |
| 528 | claim = claim_hash_find(bat_priv, &search_claim); |
| 529 | |
| 530 | /* create a new claim entry if it does not exist yet. */ |
| 531 | if (!claim) { |
| 532 | claim = kzalloc(sizeof(*claim), GFP_ATOMIC); |
| 533 | if (!claim) |
| 534 | return; |
| 535 | |
| 536 | memcpy(claim->addr, mac, ETH_ALEN); |
| 537 | claim->vid = vid; |
| 538 | claim->lasttime = jiffies; |
| 539 | claim->backbone_gw = backbone_gw; |
| 540 | |
| 541 | atomic_set(&claim->refcount, 2); |
| 542 | bat_dbg(DBG_BLA, bat_priv, |
| 543 | "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n", |
| 544 | mac, vid); |
| 545 | hash_added = hash_add(bat_priv->claim_hash, compare_claim, |
| 546 | choose_claim, claim, &claim->hash_entry); |
| 547 | |
| 548 | if (unlikely(hash_added != 0)) { |
| 549 | /* only local changes happened. */ |
| 550 | kfree(claim); |
| 551 | return; |
| 552 | } |
| 553 | } else { |
| 554 | claim->lasttime = jiffies; |
| 555 | if (claim->backbone_gw == backbone_gw) |
| 556 | /* no need to register a new backbone */ |
| 557 | goto claim_free_ref; |
| 558 | |
| 559 | bat_dbg(DBG_BLA, bat_priv, |
| 560 | "bla_add_claim(): changing ownership for %pM, vid %d\n", |
| 561 | mac, vid); |
| 562 | |
| 563 | claim->backbone_gw->crc ^= |
| 564 | crc16(0, claim->addr, ETH_ALEN); |
| 565 | backbone_gw_free_ref(claim->backbone_gw); |
| 566 | |
| 567 | } |
| 568 | /* set (new) backbone gw */ |
| 569 | atomic_inc(&backbone_gw->refcount); |
| 570 | claim->backbone_gw = backbone_gw; |
| 571 | |
| 572 | backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); |
| 573 | backbone_gw->lasttime = jiffies; |
| 574 | |
| 575 | claim_free_ref: |
| 576 | claim_free_ref(claim); |
| 577 | } |
| 578 | |
| 579 | /* Delete a claim from the claim hash which has the |
| 580 | * given mac address and vid. |
| 581 | */ |
| 582 | static void bla_del_claim(struct bat_priv *bat_priv, const uint8_t *mac, |
| 583 | const short vid) |
| 584 | { |
| 585 | struct claim search_claim, *claim; |
| 586 | |
| 587 | memcpy(search_claim.addr, mac, ETH_ALEN); |
| 588 | search_claim.vid = vid; |
| 589 | claim = claim_hash_find(bat_priv, &search_claim); |
| 590 | if (!claim) |
| 591 | return; |
| 592 | |
| 593 | bat_dbg(DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n", mac, vid); |
| 594 | |
| 595 | hash_remove(bat_priv->claim_hash, compare_claim, choose_claim, claim); |
| 596 | claim_free_ref(claim); /* reference from the hash is gone */ |
| 597 | |
| 598 | claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); |
| 599 | |
| 600 | /* don't need the reference from hash_find() anymore */ |
| 601 | claim_free_ref(claim); |
| 602 | } |
| 603 | |
| 604 | /* check for ANNOUNCE frame, return 1 if handled */ |
| 605 | static int handle_announce(struct bat_priv *bat_priv, |
| 606 | uint8_t *an_addr, uint8_t *backbone_addr, short vid) |
| 607 | { |
| 608 | struct backbone_gw *backbone_gw; |
| 609 | uint16_t crc; |
| 610 | |
| 611 | if (memcmp(an_addr, announce_mac, 4) != 0) |
| 612 | return 0; |
| 613 | |
| 614 | backbone_gw = bla_get_backbone_gw(bat_priv, backbone_addr, vid); |
| 615 | |
| 616 | if (unlikely(!backbone_gw)) |
| 617 | return 1; |
| 618 | |
| 619 | |
| 620 | /* handle as ANNOUNCE frame */ |
| 621 | backbone_gw->lasttime = jiffies; |
| 622 | crc = ntohs(*((uint16_t *)(&an_addr[4]))); |
| 623 | |
| 624 | bat_dbg(DBG_BLA, bat_priv, |
| 625 | "handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %04x\n", |
| 626 | vid, backbone_gw->orig, crc); |
| 627 | |
| 628 | if (backbone_gw->crc != crc) { |
| 629 | bat_dbg(DBG_BLA, backbone_gw->bat_priv, |
| 630 | "handle_announce(): CRC FAILED for %pM/%d (my = %04x, sent = %04x)\n", |
| 631 | backbone_gw->orig, backbone_gw->vid, backbone_gw->crc, |
| 632 | crc); |
| 633 | |
| 634 | bla_send_request(backbone_gw); |
| 635 | } else { |
| 636 | /* if we have sent a request and the crc was OK, |
| 637 | * we can allow traffic again. |
| 638 | */ |
| 639 | if (atomic_read(&backbone_gw->request_sent)) { |
| 640 | atomic_dec(&backbone_gw->bat_priv->bla_num_requests); |
| 641 | atomic_set(&backbone_gw->request_sent, 0); |
| 642 | } |
| 643 | } |
| 644 | |
| 645 | backbone_gw_free_ref(backbone_gw); |
| 646 | return 1; |
| 647 | } |
| 648 | |
| 649 | /* check for REQUEST frame, return 1 if handled */ |
| 650 | static int handle_request(struct bat_priv *bat_priv, |
| 651 | struct hard_iface *primary_if, |
| 652 | uint8_t *backbone_addr, |
| 653 | struct ethhdr *ethhdr, short vid) |
| 654 | { |
| 655 | /* check for REQUEST frame */ |
| 656 | if (!compare_eth(backbone_addr, ethhdr->h_dest)) |
| 657 | return 0; |
| 658 | |
| 659 | /* sanity check, this should not happen on a normal switch, |
| 660 | * we ignore it in this case. |
| 661 | */ |
| 662 | if (!compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr)) |
| 663 | return 1; |
| 664 | |
| 665 | bat_dbg(DBG_BLA, bat_priv, |
| 666 | "handle_request(): REQUEST vid %d (sent by %pM)...\n", |
| 667 | vid, ethhdr->h_source); |
| 668 | |
| 669 | bla_answer_request(bat_priv, primary_if, vid); |
| 670 | return 1; |
| 671 | } |
| 672 | |
| 673 | /* check for UNCLAIM frame, return 1 if handled */ |
| 674 | static int handle_unclaim(struct bat_priv *bat_priv, |
| 675 | struct hard_iface *primary_if, |
| 676 | uint8_t *backbone_addr, |
| 677 | uint8_t *claim_addr, short vid) |
| 678 | { |
| 679 | struct backbone_gw *backbone_gw; |
| 680 | |
| 681 | /* unclaim in any case if it is our own */ |
| 682 | if (primary_if && compare_eth(backbone_addr, |
| 683 | primary_if->net_dev->dev_addr)) |
| 684 | bla_send_claim(bat_priv, claim_addr, vid, CLAIM_TYPE_DEL); |
| 685 | |
| 686 | backbone_gw = backbone_hash_find(bat_priv, backbone_addr, vid); |
| 687 | |
| 688 | if (!backbone_gw) |
| 689 | return 1; |
| 690 | |
| 691 | /* this must be an UNCLAIM frame */ |
| 692 | bat_dbg(DBG_BLA, bat_priv, |
| 693 | "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n", |
| 694 | claim_addr, vid, backbone_gw->orig); |
| 695 | |
| 696 | bla_del_claim(bat_priv, claim_addr, vid); |
| 697 | backbone_gw_free_ref(backbone_gw); |
| 698 | return 1; |
| 699 | } |
| 700 | |
| 701 | /* check for CLAIM frame, return 1 if handled */ |
| 702 | static int handle_claim(struct bat_priv *bat_priv, |
| 703 | struct hard_iface *primary_if, uint8_t *backbone_addr, |
| 704 | uint8_t *claim_addr, short vid) |
| 705 | { |
| 706 | struct backbone_gw *backbone_gw; |
| 707 | |
| 708 | /* register the gateway if not yet available, and add the claim. */ |
| 709 | |
| 710 | backbone_gw = bla_get_backbone_gw(bat_priv, backbone_addr, vid); |
| 711 | |
| 712 | if (unlikely(!backbone_gw)) |
| 713 | return 1; |
| 714 | |
| 715 | /* this must be a CLAIM frame */ |
| 716 | bla_add_claim(bat_priv, claim_addr, vid, backbone_gw); |
| 717 | if (compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) |
| 718 | bla_send_claim(bat_priv, claim_addr, vid, CLAIM_TYPE_ADD); |
| 719 | |
| 720 | /* TODO: we could call something like tt_local_del() here. */ |
| 721 | |
| 722 | backbone_gw_free_ref(backbone_gw); |
| 723 | return 1; |
| 724 | } |
| 725 | |
| 726 | /** |
| 727 | * @bat_priv: the bat priv with all the soft interface information |
| 728 | * @skb: the frame to be checked |
| 729 | * |
| 730 | * Check if this is a claim frame, and process it accordingly. |
| 731 | * |
| 732 | * returns 1 if it was a claim frame, otherwise return 0 to |
| 733 | * tell the callee that it can use the frame on its own. |
| 734 | */ |
| 735 | static int bla_process_claim(struct bat_priv *bat_priv, |
| 736 | struct hard_iface *primary_if, |
| 737 | struct sk_buff *skb) |
| 738 | { |
| 739 | struct ethhdr *ethhdr; |
| 740 | struct vlan_ethhdr *vhdr; |
| 741 | struct arphdr *arphdr; |
| 742 | uint8_t *hw_src, *hw_dst; |
| 743 | struct bla_claim_dst *bla_dst; |
| 744 | uint16_t proto; |
| 745 | int headlen; |
| 746 | short vid = -1; |
| 747 | |
| 748 | ethhdr = (struct ethhdr *)skb_mac_header(skb); |
| 749 | |
| 750 | if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) { |
| 751 | vhdr = (struct vlan_ethhdr *)ethhdr; |
| 752 | vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK; |
| 753 | proto = ntohs(vhdr->h_vlan_encapsulated_proto); |
| 754 | headlen = sizeof(*vhdr); |
| 755 | } else { |
| 756 | proto = ntohs(ethhdr->h_proto); |
| 757 | headlen = sizeof(*ethhdr); |
| 758 | } |
| 759 | |
| 760 | if (proto != ETH_P_ARP) |
| 761 | return 0; /* not a claim frame */ |
| 762 | |
| 763 | /* this must be a ARP frame. check if it is a claim. */ |
| 764 | |
| 765 | if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev)))) |
| 766 | return 0; |
| 767 | |
| 768 | /* pskb_may_pull() may have modified the pointers, get ethhdr again */ |
| 769 | ethhdr = (struct ethhdr *)skb_mac_header(skb); |
| 770 | arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen); |
| 771 | |
| 772 | /* Check whether the ARP frame carries a valid |
| 773 | * IP information |
| 774 | */ |
| 775 | |
| 776 | if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) |
| 777 | return 0; |
| 778 | if (arphdr->ar_pro != htons(ETH_P_IP)) |
| 779 | return 0; |
| 780 | if (arphdr->ar_hln != ETH_ALEN) |
| 781 | return 0; |
| 782 | if (arphdr->ar_pln != 4) |
| 783 | return 0; |
| 784 | |
| 785 | hw_src = (uint8_t *)arphdr + sizeof(struct arphdr); |
| 786 | hw_dst = hw_src + ETH_ALEN + 4; |
| 787 | bla_dst = (struct bla_claim_dst *)hw_dst; |
| 788 | |
| 789 | /* check if it is a claim frame. */ |
| 790 | if (memcmp(hw_dst, claim_dest, 3) != 0) |
| 791 | return 0; |
| 792 | |
| 793 | /* become a backbone gw ourselves on this vlan if not happened yet */ |
| 794 | bla_update_own_backbone_gw(bat_priv, primary_if, vid); |
| 795 | |
| 796 | /* check for the different types of claim frames ... */ |
| 797 | switch (bla_dst->type) { |
| 798 | case CLAIM_TYPE_ADD: |
| 799 | if (handle_claim(bat_priv, primary_if, hw_src, |
| 800 | ethhdr->h_source, vid)) |
| 801 | return 1; |
| 802 | break; |
| 803 | case CLAIM_TYPE_DEL: |
| 804 | if (handle_unclaim(bat_priv, primary_if, |
| 805 | ethhdr->h_source, hw_src, vid)) |
| 806 | return 1; |
| 807 | break; |
| 808 | |
| 809 | case CLAIM_TYPE_ANNOUNCE: |
| 810 | if (handle_announce(bat_priv, hw_src, ethhdr->h_source, vid)) |
| 811 | return 1; |
| 812 | break; |
| 813 | case CLAIM_TYPE_REQUEST: |
| 814 | if (handle_request(bat_priv, primary_if, hw_src, ethhdr, vid)) |
| 815 | return 1; |
| 816 | break; |
| 817 | } |
| 818 | |
| 819 | bat_dbg(DBG_BLA, bat_priv, |
| 820 | "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", |
| 821 | ethhdr->h_source, vid, hw_src, hw_dst); |
| 822 | return 1; |
| 823 | } |
| 824 | |
| 825 | /* Check when we last heard from other nodes, and remove them in case of |
| 826 | * a time out, or clean all backbone gws if now is set. |
| 827 | */ |
| 828 | static void bla_purge_backbone_gw(struct bat_priv *bat_priv, int now) |
| 829 | { |
| 830 | struct backbone_gw *backbone_gw; |
| 831 | struct hlist_node *node, *node_tmp; |
| 832 | struct hlist_head *head; |
| 833 | struct hashtable_t *hash; |
| 834 | spinlock_t *list_lock; /* protects write access to the hash lists */ |
| 835 | int i; |
| 836 | |
| 837 | hash = bat_priv->backbone_hash; |
| 838 | if (!hash) |
| 839 | return; |
| 840 | |
| 841 | for (i = 0; i < hash->size; i++) { |
| 842 | head = &hash->table[i]; |
| 843 | list_lock = &hash->list_locks[i]; |
| 844 | |
| 845 | spin_lock_bh(list_lock); |
| 846 | hlist_for_each_entry_safe(backbone_gw, node, node_tmp, |
| 847 | head, hash_entry) { |
| 848 | if (now) |
| 849 | goto purge_now; |
| 850 | if (!has_timed_out(backbone_gw->lasttime, |
| 851 | BLA_BACKBONE_TIMEOUT)) |
| 852 | continue; |
| 853 | |
| 854 | bat_dbg(DBG_BLA, backbone_gw->bat_priv, |
| 855 | "bla_purge_backbone_gw(): backbone gw %pM timed out\n", |
| 856 | backbone_gw->orig); |
| 857 | |
| 858 | purge_now: |
| 859 | /* don't wait for the pending request anymore */ |
| 860 | if (atomic_read(&backbone_gw->request_sent)) |
| 861 | atomic_dec(&bat_priv->bla_num_requests); |
| 862 | |
| 863 | bla_del_backbone_claims(backbone_gw); |
| 864 | |
| 865 | hlist_del_rcu(node); |
| 866 | backbone_gw_free_ref(backbone_gw); |
| 867 | } |
| 868 | spin_unlock_bh(list_lock); |
| 869 | } |
| 870 | } |
| 871 | |
| 872 | /** |
| 873 | * @bat_priv: the bat priv with all the soft interface information |
| 874 | * @primary_if: the selected primary interface, may be NULL if now is set |
| 875 | * @now: whether the whole hash shall be wiped now |
| 876 | * |
| 877 | * Check when we heard last time from our own claims, and remove them in case of |
| 878 | * a time out, or clean all claims if now is set |
| 879 | */ |
| 880 | static void bla_purge_claims(struct bat_priv *bat_priv, |
| 881 | struct hard_iface *primary_if, int now) |
| 882 | { |
| 883 | struct claim *claim; |
| 884 | struct hlist_node *node; |
| 885 | struct hlist_head *head; |
| 886 | struct hashtable_t *hash; |
| 887 | int i; |
| 888 | |
| 889 | hash = bat_priv->claim_hash; |
| 890 | if (!hash) |
| 891 | return; |
| 892 | |
| 893 | for (i = 0; i < hash->size; i++) { |
| 894 | head = &hash->table[i]; |
| 895 | |
| 896 | rcu_read_lock(); |
| 897 | hlist_for_each_entry_rcu(claim, node, head, hash_entry) { |
| 898 | if (now) |
| 899 | goto purge_now; |
| 900 | if (!compare_eth(claim->backbone_gw->orig, |
| 901 | primary_if->net_dev->dev_addr)) |
| 902 | continue; |
| 903 | if (!has_timed_out(claim->lasttime, |
| 904 | BLA_CLAIM_TIMEOUT)) |
| 905 | continue; |
| 906 | |
| 907 | bat_dbg(DBG_BLA, bat_priv, |
| 908 | "bla_purge_claims(): %pM, vid %d, time out\n", |
| 909 | claim->addr, claim->vid); |
| 910 | |
| 911 | purge_now: |
| 912 | handle_unclaim(bat_priv, primary_if, |
| 913 | claim->backbone_gw->orig, |
| 914 | claim->addr, claim->vid); |
| 915 | } |
| 916 | rcu_read_unlock(); |
| 917 | } |
| 918 | } |
| 919 | |
| 920 | /** |
| 921 | * @bat_priv: the bat priv with all the soft interface information |
| 922 | * @primary_if: the new selected primary_if |
| 923 | * @oldif: the old primary interface, may be NULL |
| 924 | * |
| 925 | * Update the backbone gateways when the own orig address changes. |
| 926 | * |
| 927 | */ |
| 928 | void bla_update_orig_address(struct bat_priv *bat_priv, |
| 929 | struct hard_iface *primary_if, |
| 930 | struct hard_iface *oldif) |
| 931 | { |
| 932 | struct backbone_gw *backbone_gw; |
| 933 | struct hlist_node *node; |
| 934 | struct hlist_head *head; |
| 935 | struct hashtable_t *hash; |
| 936 | int i; |
| 937 | |
| 938 | if (!oldif) { |
| 939 | bla_purge_claims(bat_priv, NULL, 1); |
| 940 | bla_purge_backbone_gw(bat_priv, 1); |
| 941 | return; |
| 942 | } |
| 943 | |
| 944 | hash = bat_priv->backbone_hash; |
| 945 | if (!hash) |
| 946 | return; |
| 947 | |
| 948 | for (i = 0; i < hash->size; i++) { |
| 949 | head = &hash->table[i]; |
| 950 | |
| 951 | rcu_read_lock(); |
| 952 | hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) { |
| 953 | /* own orig still holds the old value. */ |
| 954 | if (!compare_eth(backbone_gw->orig, |
| 955 | oldif->net_dev->dev_addr)) |
| 956 | continue; |
| 957 | |
| 958 | memcpy(backbone_gw->orig, |
| 959 | primary_if->net_dev->dev_addr, ETH_ALEN); |
| 960 | /* send an announce frame so others will ask for our |
| 961 | * claims and update their tables. |
| 962 | */ |
| 963 | bla_send_announce(bat_priv, backbone_gw); |
| 964 | } |
| 965 | rcu_read_unlock(); |
| 966 | } |
| 967 | } |
| 968 | |
| 969 | |
| 970 | |
| 971 | /* (re)start the timer */ |
| 972 | static void bla_start_timer(struct bat_priv *bat_priv) |
| 973 | { |
| 974 | INIT_DELAYED_WORK(&bat_priv->bla_work, bla_periodic_work); |
| 975 | queue_delayed_work(bat_event_workqueue, &bat_priv->bla_work, |
| 976 | msecs_to_jiffies(BLA_PERIOD_LENGTH)); |
| 977 | } |
| 978 | |
| 979 | /* periodic work to do: |
| 980 | * * purge structures when they are too old |
| 981 | * * send announcements |
| 982 | */ |
| 983 | static void bla_periodic_work(struct work_struct *work) |
| 984 | { |
| 985 | struct delayed_work *delayed_work = |
| 986 | container_of(work, struct delayed_work, work); |
| 987 | struct bat_priv *bat_priv = |
| 988 | container_of(delayed_work, struct bat_priv, bla_work); |
| 989 | struct hlist_node *node; |
| 990 | struct hlist_head *head; |
| 991 | struct backbone_gw *backbone_gw; |
| 992 | struct hashtable_t *hash; |
| 993 | struct hard_iface *primary_if; |
| 994 | int i; |
| 995 | |
| 996 | primary_if = primary_if_get_selected(bat_priv); |
| 997 | if (!primary_if) |
| 998 | goto out; |
| 999 | |
| 1000 | bla_purge_claims(bat_priv, primary_if, 0); |
| 1001 | bla_purge_backbone_gw(bat_priv, 0); |
| 1002 | |
| 1003 | if (!atomic_read(&bat_priv->bridge_loop_avoidance)) |
| 1004 | goto out; |
| 1005 | |
| 1006 | hash = bat_priv->backbone_hash; |
| 1007 | if (!hash) |
| 1008 | goto out; |
| 1009 | |
| 1010 | for (i = 0; i < hash->size; i++) { |
| 1011 | head = &hash->table[i]; |
| 1012 | |
| 1013 | rcu_read_lock(); |
| 1014 | hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) { |
| 1015 | if (!compare_eth(backbone_gw->orig, |
| 1016 | primary_if->net_dev->dev_addr)) |
| 1017 | continue; |
| 1018 | |
| 1019 | backbone_gw->lasttime = jiffies; |
| 1020 | |
| 1021 | bla_send_announce(bat_priv, backbone_gw); |
| 1022 | } |
| 1023 | rcu_read_unlock(); |
| 1024 | } |
| 1025 | out: |
| 1026 | if (primary_if) |
| 1027 | hardif_free_ref(primary_if); |
| 1028 | |
| 1029 | bla_start_timer(bat_priv); |
| 1030 | } |
| 1031 | |
| 1032 | /* initialize all bla structures */ |
| 1033 | int bla_init(struct bat_priv *bat_priv) |
| 1034 | { |
| 1035 | bat_dbg(DBG_BLA, bat_priv, "bla hash registering\n"); |
| 1036 | |
| 1037 | if (bat_priv->claim_hash) |
| 1038 | return 1; |
| 1039 | |
| 1040 | bat_priv->claim_hash = hash_new(128); |
| 1041 | bat_priv->backbone_hash = hash_new(32); |
| 1042 | |
| 1043 | if (!bat_priv->claim_hash || !bat_priv->backbone_hash) |
| 1044 | return -1; |
| 1045 | |
| 1046 | bat_dbg(DBG_BLA, bat_priv, "bla hashes initialized\n"); |
| 1047 | |
| 1048 | bla_start_timer(bat_priv); |
| 1049 | return 1; |
| 1050 | } |
| 1051 | |
| 1052 | /** |
| 1053 | * @skb: the frame to be checked |
| 1054 | * @orig_node: the orig_node of the frame |
| 1055 | * @hdr_size: maximum length of the frame |
| 1056 | * |
| 1057 | * bla_is_backbone_gw inspects the skb for the VLAN ID and returns 1 |
| 1058 | * if the orig_node is also a gateway on the soft interface, otherwise it |
| 1059 | * returns 0. |
| 1060 | * |
| 1061 | */ |
| 1062 | int bla_is_backbone_gw(struct sk_buff *skb, |
| 1063 | struct orig_node *orig_node, int hdr_size) |
| 1064 | { |
| 1065 | struct ethhdr *ethhdr; |
| 1066 | struct vlan_ethhdr *vhdr; |
| 1067 | struct backbone_gw *backbone_gw; |
| 1068 | short vid = -1; |
| 1069 | |
| 1070 | if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance)) |
| 1071 | return 0; |
| 1072 | |
| 1073 | /* first, find out the vid. */ |
| 1074 | if (!pskb_may_pull(skb, hdr_size + sizeof(struct ethhdr))) |
| 1075 | return 0; |
| 1076 | |
| 1077 | ethhdr = (struct ethhdr *)(((uint8_t *)skb->data) + hdr_size); |
| 1078 | |
| 1079 | if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) { |
| 1080 | if (!pskb_may_pull(skb, hdr_size + sizeof(struct vlan_ethhdr))) |
| 1081 | return 0; |
| 1082 | |
| 1083 | vhdr = (struct vlan_ethhdr *)(((uint8_t *)skb->data) + |
| 1084 | hdr_size); |
| 1085 | vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK; |
| 1086 | } |
| 1087 | |
| 1088 | /* see if this originator is a backbone gw for this VLAN */ |
| 1089 | |
| 1090 | backbone_gw = backbone_hash_find(orig_node->bat_priv, |
| 1091 | orig_node->orig, vid); |
| 1092 | if (!backbone_gw) |
| 1093 | return 0; |
| 1094 | |
| 1095 | backbone_gw_free_ref(backbone_gw); |
| 1096 | return 1; |
| 1097 | } |
| 1098 | |
| 1099 | /* free all bla structures (for softinterface free or module unload) */ |
| 1100 | void bla_free(struct bat_priv *bat_priv) |
| 1101 | { |
| 1102 | struct hard_iface *primary_if; |
| 1103 | |
| 1104 | cancel_delayed_work_sync(&bat_priv->bla_work); |
| 1105 | primary_if = primary_if_get_selected(bat_priv); |
| 1106 | |
| 1107 | if (bat_priv->claim_hash) { |
| 1108 | bla_purge_claims(bat_priv, primary_if, 1); |
| 1109 | hash_destroy(bat_priv->claim_hash); |
| 1110 | bat_priv->claim_hash = NULL; |
| 1111 | } |
| 1112 | if (bat_priv->backbone_hash) { |
| 1113 | bla_purge_backbone_gw(bat_priv, 1); |
| 1114 | hash_destroy(bat_priv->backbone_hash); |
| 1115 | bat_priv->backbone_hash = NULL; |
| 1116 | } |
| 1117 | if (primary_if) |
| 1118 | hardif_free_ref(primary_if); |
| 1119 | } |
| 1120 | |
| 1121 | /** |
| 1122 | * @bat_priv: the bat priv with all the soft interface information |
| 1123 | * @skb: the frame to be checked |
| 1124 | * @vid: the VLAN ID of the frame |
| 1125 | * |
| 1126 | * bla_rx avoidance checks if: |
| 1127 | * * we have to race for a claim |
| 1128 | * * if the frame is allowed on the LAN |
| 1129 | * |
| 1130 | * in these cases, the skb is further handled by this function and |
| 1131 | * returns 1, otherwise it returns 0 and the caller shall further |
| 1132 | * process the skb. |
| 1133 | * |
| 1134 | */ |
| 1135 | int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid) |
| 1136 | { |
| 1137 | struct ethhdr *ethhdr; |
| 1138 | struct claim search_claim, *claim = NULL; |
| 1139 | struct hard_iface *primary_if; |
| 1140 | int ret; |
| 1141 | |
| 1142 | ethhdr = (struct ethhdr *)skb_mac_header(skb); |
| 1143 | |
| 1144 | primary_if = primary_if_get_selected(bat_priv); |
| 1145 | if (!primary_if) |
| 1146 | goto handled; |
| 1147 | |
| 1148 | if (!atomic_read(&bat_priv->bridge_loop_avoidance)) |
| 1149 | goto allow; |
| 1150 | |
| 1151 | |
| 1152 | if (unlikely(atomic_read(&bat_priv->bla_num_requests))) |
| 1153 | /* don't allow broadcasts while requests are in flight */ |
| 1154 | if (is_multicast_ether_addr(ethhdr->h_dest)) |
| 1155 | goto handled; |
| 1156 | |
| 1157 | memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN); |
| 1158 | search_claim.vid = vid; |
| 1159 | claim = claim_hash_find(bat_priv, &search_claim); |
| 1160 | |
| 1161 | if (!claim) { |
| 1162 | /* possible optimization: race for a claim */ |
| 1163 | /* No claim exists yet, claim it for us! |
| 1164 | */ |
| 1165 | handle_claim(bat_priv, primary_if, |
| 1166 | primary_if->net_dev->dev_addr, |
| 1167 | ethhdr->h_source, vid); |
| 1168 | goto allow; |
| 1169 | } |
| 1170 | |
| 1171 | /* if it is our own claim ... */ |
| 1172 | if (compare_eth(claim->backbone_gw->orig, |
| 1173 | primary_if->net_dev->dev_addr)) { |
| 1174 | /* ... allow it in any case */ |
| 1175 | claim->lasttime = jiffies; |
| 1176 | goto allow; |
| 1177 | } |
| 1178 | |
| 1179 | /* if it is a broadcast ... */ |
| 1180 | if (is_multicast_ether_addr(ethhdr->h_dest)) { |
| 1181 | /* ... drop it. the responsible gateway is in charge. */ |
| 1182 | goto handled; |
| 1183 | } else { |
| 1184 | /* seems the client considers us as its best gateway. |
| 1185 | * send a claim and update the claim table |
| 1186 | * immediately. |
| 1187 | */ |
| 1188 | handle_claim(bat_priv, primary_if, |
| 1189 | primary_if->net_dev->dev_addr, |
| 1190 | ethhdr->h_source, vid); |
| 1191 | goto allow; |
| 1192 | } |
| 1193 | allow: |
| 1194 | bla_update_own_backbone_gw(bat_priv, primary_if, vid); |
| 1195 | ret = 0; |
| 1196 | goto out; |
| 1197 | |
| 1198 | handled: |
| 1199 | kfree_skb(skb); |
| 1200 | ret = 1; |
| 1201 | |
| 1202 | out: |
| 1203 | if (primary_if) |
| 1204 | hardif_free_ref(primary_if); |
| 1205 | if (claim) |
| 1206 | claim_free_ref(claim); |
| 1207 | return ret; |
| 1208 | } |
| 1209 | |
| 1210 | /** |
| 1211 | * @bat_priv: the bat priv with all the soft interface information |
| 1212 | * @skb: the frame to be checked |
| 1213 | * @vid: the VLAN ID of the frame |
| 1214 | * |
| 1215 | * bla_tx checks if: |
| 1216 | * * a claim was received which has to be processed |
| 1217 | * * the frame is allowed on the mesh |
| 1218 | * |
| 1219 | * in these cases, the skb is further handled by this function and |
| 1220 | * returns 1, otherwise it returns 0 and the caller shall further |
| 1221 | * process the skb. |
| 1222 | * |
| 1223 | */ |
| 1224 | int bla_tx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid) |
| 1225 | { |
| 1226 | struct ethhdr *ethhdr; |
| 1227 | struct claim search_claim, *claim = NULL; |
| 1228 | struct hard_iface *primary_if; |
| 1229 | int ret = 0; |
| 1230 | |
| 1231 | primary_if = primary_if_get_selected(bat_priv); |
| 1232 | if (!primary_if) |
| 1233 | goto out; |
| 1234 | |
| 1235 | if (!atomic_read(&bat_priv->bridge_loop_avoidance)) |
| 1236 | goto allow; |
| 1237 | |
| 1238 | /* in VLAN case, the mac header might not be set. */ |
| 1239 | skb_reset_mac_header(skb); |
| 1240 | |
| 1241 | if (bla_process_claim(bat_priv, primary_if, skb)) |
| 1242 | goto handled; |
| 1243 | |
| 1244 | ethhdr = (struct ethhdr *)skb_mac_header(skb); |
| 1245 | |
| 1246 | if (unlikely(atomic_read(&bat_priv->bla_num_requests))) |
| 1247 | /* don't allow broadcasts while requests are in flight */ |
| 1248 | if (is_multicast_ether_addr(ethhdr->h_dest)) |
| 1249 | goto handled; |
| 1250 | |
| 1251 | memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN); |
| 1252 | search_claim.vid = vid; |
| 1253 | |
| 1254 | claim = claim_hash_find(bat_priv, &search_claim); |
| 1255 | |
| 1256 | /* if no claim exists, allow it. */ |
| 1257 | if (!claim) |
| 1258 | goto allow; |
| 1259 | |
| 1260 | /* check if we are responsible. */ |
| 1261 | if (compare_eth(claim->backbone_gw->orig, |
| 1262 | primary_if->net_dev->dev_addr)) { |
| 1263 | /* if yes, the client has roamed and we have |
| 1264 | * to unclaim it. |
| 1265 | */ |
| 1266 | handle_unclaim(bat_priv, primary_if, |
| 1267 | primary_if->net_dev->dev_addr, |
| 1268 | ethhdr->h_source, vid); |
| 1269 | goto allow; |
| 1270 | } |
| 1271 | |
| 1272 | /* check if it is a multicast/broadcast frame */ |
| 1273 | if (is_multicast_ether_addr(ethhdr->h_dest)) { |
| 1274 | /* drop it. the responsible gateway has forwarded it into |
| 1275 | * the backbone network. |
| 1276 | */ |
| 1277 | goto handled; |
| 1278 | } else { |
| 1279 | /* we must allow it. at least if we are |
| 1280 | * responsible for the DESTINATION. |
| 1281 | */ |
| 1282 | goto allow; |
| 1283 | } |
| 1284 | allow: |
| 1285 | bla_update_own_backbone_gw(bat_priv, primary_if, vid); |
| 1286 | ret = 0; |
| 1287 | goto out; |
| 1288 | handled: |
| 1289 | ret = 1; |
| 1290 | out: |
| 1291 | if (primary_if) |
| 1292 | hardif_free_ref(primary_if); |
| 1293 | if (claim) |
| 1294 | claim_free_ref(claim); |
| 1295 | return ret; |
| 1296 | } |