1 /* 2 * Copyright (c) 2008 open80211s Ltd. 3 * Authors: Luis Carlos Cobo <luisca@cozybit.com> 4 * Javier Cardona <javier@cozybit.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <asm/unaligned.h> 12 #include "ieee80211_i.h" 13 #include "mesh.h" 14 15 #define PP_OFFSET 1 /* Path Selection Protocol */ 16 #define PM_OFFSET 5 /* Path Selection Metric */ 17 #define CC_OFFSET 9 /* Congestion Control Mode */ 18 #define CAPAB_OFFSET 17 19 #define ACCEPT_PLINKS 0x80 20 21 int mesh_allocated; 22 static struct kmem_cache *rm_cache; 23 24 void ieee80211s_init(void) 25 { 26 mesh_pathtbl_init(); 27 mesh_allocated = 1; 28 rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry), 29 0, 0, NULL); 30 } 31 32 void ieee80211s_stop(void) 33 { 34 mesh_pathtbl_unregister(); 35 kmem_cache_destroy(rm_cache); 36 } 37 38 /** 39 * mesh_matches_local - check if the config of a mesh point matches ours 40 * 41 * @ie: information elements of a management frame from the mesh peer 42 * @dev: local mesh interface 43 * 44 * This function checks if the mesh configuration of a mesh point matches the 45 * local mesh configuration, i.e. if both nodes belong to the same mesh network. 46 */ 47 bool mesh_matches_local(struct ieee802_11_elems *ie, struct net_device *dev) 48 { 49 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); 50 struct ieee80211_if_sta *sta = &sdata->u.sta; 51 52 /* 53 * As support for each feature is added, check for matching 54 * - On mesh config capabilities 55 * - Power Save Support En 56 * - Sync support enabled 57 * - Sync support active 58 * - Sync support required from peer 59 * - MDA enabled 60 * - Power management control on fc 61 */ 62 if (sta->mesh_id_len == ie->mesh_id_len && 63 memcmp(sta->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 && 64 memcmp(sta->mesh_pp_id, ie->mesh_config + PP_OFFSET, 4) == 0 && 65 memcmp(sta->mesh_pm_id, ie->mesh_config + PM_OFFSET, 4) == 0 && 66 memcmp(sta->mesh_cc_id, ie->mesh_config + CC_OFFSET, 4) == 0) 67 return true; 68 69 return false; 70 } 71 72 /** 73 * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links 74 * 75 * @ie: information elements of a management frame from the mesh peer 76 * @dev: local mesh interface 77 */ 78 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie, 79 struct net_device *dev) 80 { 81 return (*(ie->mesh_config + CAPAB_OFFSET) & ACCEPT_PLINKS) != 0; 82 } 83 84 /** 85 * mesh_accept_plinks_update: update accepting_plink in local mesh beacons 86 * 87 * @sdata: mesh interface in which mesh beacons are going to be updated 88 */ 89 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata) 90 { 91 bool free_plinks; 92 93 /* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0, 94 * the mesh interface might be able to establish plinks with peers that 95 * are already on the table but are not on PLINK_ESTAB state. However, 96 * in general the mesh interface is not accepting peer link requests 97 * from new peers, and that must be reflected in the beacon 98 */ 99 free_plinks = mesh_plink_availables(sdata); 100 101 if (free_plinks != sdata->u.sta.accepting_plinks) 102 ieee80211_sta_timer((unsigned long) sdata); 103 } 104 105 void mesh_ids_set_default(struct ieee80211_if_sta *sta) 106 { 107 u8 def_id[4] = {0x00, 0x0F, 0xAC, 0xff}; 108 109 memcpy(sta->mesh_pp_id, def_id, 4); 110 memcpy(sta->mesh_pm_id, def_id, 4); 111 memcpy(sta->mesh_cc_id, def_id, 4); 112 } 113 114 int mesh_rmc_init(struct net_device *dev) 115 { 116 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); 117 int i; 118 119 sdata->u.sta.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL); 120 if (!sdata->u.sta.rmc) 121 return -ENOMEM; 122 sdata->u.sta.rmc->idx_mask = RMC_BUCKETS - 1; 123 for (i = 0; i < RMC_BUCKETS; i++) 124 INIT_LIST_HEAD(&sdata->u.sta.rmc->bucket[i].list); 125 return 0; 126 } 127 128 void mesh_rmc_free(struct net_device *dev) 129 { 130 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); 131 struct mesh_rmc *rmc = sdata->u.sta.rmc; 132 struct rmc_entry *p, *n; 133 int i; 134 135 if (!sdata->u.sta.rmc) 136 return; 137 138 for (i = 0; i < RMC_BUCKETS; i++) 139 list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) { 140 list_del(&p->list); 141 kmem_cache_free(rm_cache, p); 142 } 143 144 kfree(rmc); 145 sdata->u.sta.rmc = NULL; 146 } 147 148 /** 149 * mesh_rmc_check - Check frame in recent multicast cache and add if absent. 150 * 151 * @sa: source address 152 * @mesh_hdr: mesh_header 153 * 154 * Returns: 0 if the frame is not in the cache, nonzero otherwise. 155 * 156 * Checks using the source address and the mesh sequence number if we have 157 * received this frame lately. If the frame is not in the cache, it is added to 158 * it. 159 */ 160 int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr, 161 struct net_device *dev) 162 { 163 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); 164 struct mesh_rmc *rmc = sdata->u.sta.rmc; 165 u32 seqnum = 0; 166 int entries = 0; 167 u8 idx; 168 struct rmc_entry *p, *n; 169 170 /* Don't care about endianness since only match matters */ 171 memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum)); 172 idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask; 173 list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) { 174 ++entries; 175 if (time_after(jiffies, p->exp_time) || 176 (entries == RMC_QUEUE_MAX_LEN)) { 177 list_del(&p->list); 178 kmem_cache_free(rm_cache, p); 179 --entries; 180 } else if ((seqnum == p->seqnum) 181 && (memcmp(sa, p->sa, ETH_ALEN) == 0)) 182 return -1; 183 } 184 185 p = kmem_cache_alloc(rm_cache, GFP_ATOMIC); 186 if (!p) { 187 printk(KERN_DEBUG "o11s: could not allocate RMC entry\n"); 188 return 0; 189 } 190 p->seqnum = seqnum; 191 p->exp_time = jiffies + RMC_TIMEOUT; 192 memcpy(p->sa, sa, ETH_ALEN); 193 list_add(&p->list, &rmc->bucket[idx].list); 194 return 0; 195 } 196 197 void mesh_mgmt_ies_add(struct sk_buff *skb, struct net_device *dev) 198 { 199 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); 200 struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); 201 struct ieee80211_supported_band *sband; 202 u8 *pos; 203 int len, i, rate; 204 205 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 206 len = sband->n_bitrates; 207 if (len > 8) 208 len = 8; 209 pos = skb_put(skb, len + 2); 210 *pos++ = WLAN_EID_SUPP_RATES; 211 *pos++ = len; 212 for (i = 0; i < len; i++) { 213 rate = sband->bitrates[i].bitrate; 214 *pos++ = (u8) (rate / 5); 215 } 216 217 if (sband->n_bitrates > len) { 218 pos = skb_put(skb, sband->n_bitrates - len + 2); 219 *pos++ = WLAN_EID_EXT_SUPP_RATES; 220 *pos++ = sband->n_bitrates - len; 221 for (i = len; i < sband->n_bitrates; i++) { 222 rate = sband->bitrates[i].bitrate; 223 *pos++ = (u8) (rate / 5); 224 } 225 } 226 227 pos = skb_put(skb, 2 + sdata->u.sta.mesh_id_len); 228 *pos++ = WLAN_EID_MESH_ID; 229 *pos++ = sdata->u.sta.mesh_id_len; 230 if (sdata->u.sta.mesh_id_len) 231 memcpy(pos, sdata->u.sta.mesh_id, sdata->u.sta.mesh_id_len); 232 233 pos = skb_put(skb, 21); 234 *pos++ = WLAN_EID_MESH_CONFIG; 235 *pos++ = MESH_CFG_LEN; 236 /* Version */ 237 *pos++ = 1; 238 239 /* Active path selection protocol ID */ 240 memcpy(pos, sdata->u.sta.mesh_pp_id, 4); 241 pos += 4; 242 243 /* Active path selection metric ID */ 244 memcpy(pos, sdata->u.sta.mesh_pm_id, 4); 245 pos += 4; 246 247 /* Congestion control mode identifier */ 248 memcpy(pos, sdata->u.sta.mesh_cc_id, 4); 249 pos += 4; 250 251 /* Channel precedence: 252 * Not running simple channel unification protocol 253 */ 254 memset(pos, 0x00, 4); 255 pos += 4; 256 257 /* Mesh capability */ 258 sdata->u.sta.accepting_plinks = mesh_plink_availables(sdata); 259 *pos++ = sdata->u.sta.accepting_plinks ? ACCEPT_PLINKS : 0x00; 260 *pos++ = 0x00; 261 262 return; 263 } 264 265 u32 mesh_table_hash(u8 *addr, struct net_device *dev, struct mesh_table *tbl) 266 { 267 /* Use last four bytes of hw addr and interface index as hash index */ 268 return jhash_2words(*(u32 *)(addr+2), dev->ifindex, tbl->hash_rnd) 269 & tbl->hash_mask; 270 } 271 272 u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len) 273 { 274 if (!mesh_id_len) 275 return 1; 276 else if (mesh_id_len == 1) 277 return (u8) mesh_id[0]; 278 else 279 return (u8) (mesh_id[0] + 2 * mesh_id[1]); 280 } 281 282 struct mesh_table *mesh_table_alloc(int size_order) 283 { 284 int i; 285 struct mesh_table *newtbl; 286 287 newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL); 288 if (!newtbl) 289 return NULL; 290 291 newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) * 292 (1 << size_order), GFP_KERNEL); 293 294 if (!newtbl->hash_buckets) { 295 kfree(newtbl); 296 return NULL; 297 } 298 299 newtbl->hashwlock = kmalloc(sizeof(spinlock_t) * 300 (1 << size_order), GFP_KERNEL); 301 if (!newtbl->hashwlock) { 302 kfree(newtbl->hash_buckets); 303 kfree(newtbl); 304 return NULL; 305 } 306 307 newtbl->size_order = size_order; 308 newtbl->hash_mask = (1 << size_order) - 1; 309 atomic_set(&newtbl->entries, 0); 310 get_random_bytes(&newtbl->hash_rnd, 311 sizeof(newtbl->hash_rnd)); 312 for (i = 0; i <= newtbl->hash_mask; i++) 313 spin_lock_init(&newtbl->hashwlock[i]); 314 315 return newtbl; 316 } 317 318 static void __mesh_table_free(struct mesh_table *tbl) 319 { 320 kfree(tbl->hash_buckets); 321 kfree(tbl->hashwlock); 322 kfree(tbl); 323 } 324 325 void mesh_table_free(struct mesh_table *tbl, bool free_leafs) 326 { 327 struct hlist_head *mesh_hash; 328 struct hlist_node *p, *q; 329 int i; 330 331 mesh_hash = tbl->hash_buckets; 332 for (i = 0; i <= tbl->hash_mask; i++) { 333 spin_lock(&tbl->hashwlock[i]); 334 hlist_for_each_safe(p, q, &mesh_hash[i]) { 335 tbl->free_node(p, free_leafs); 336 atomic_dec(&tbl->entries); 337 } 338 spin_unlock(&tbl->hashwlock[i]); 339 } 340 __mesh_table_free(tbl); 341 } 342 343 static void ieee80211_mesh_path_timer(unsigned long data) 344 { 345 struct ieee80211_sub_if_data *sdata = 346 (struct ieee80211_sub_if_data *) data; 347 struct ieee80211_if_sta *ifsta = &sdata->u.sta; 348 struct ieee80211_local *local = wdev_priv(&sdata->wdev); 349 350 queue_work(local->hw.workqueue, &ifsta->work); 351 } 352 353 struct mesh_table *mesh_table_grow(struct mesh_table *tbl) 354 { 355 struct mesh_table *newtbl; 356 struct hlist_head *oldhash; 357 struct hlist_node *p, *q; 358 int i; 359 360 if (atomic_read(&tbl->entries) 361 < tbl->mean_chain_len * (tbl->hash_mask + 1)) 362 goto endgrow; 363 364 newtbl = mesh_table_alloc(tbl->size_order + 1); 365 if (!newtbl) 366 goto endgrow; 367 368 newtbl->free_node = tbl->free_node; 369 newtbl->mean_chain_len = tbl->mean_chain_len; 370 newtbl->copy_node = tbl->copy_node; 371 atomic_set(&newtbl->entries, atomic_read(&tbl->entries)); 372 373 oldhash = tbl->hash_buckets; 374 for (i = 0; i <= tbl->hash_mask; i++) 375 hlist_for_each(p, &oldhash[i]) 376 if (tbl->copy_node(p, newtbl) < 0) 377 goto errcopy; 378 379 return newtbl; 380 381 errcopy: 382 for (i = 0; i <= newtbl->hash_mask; i++) { 383 hlist_for_each_safe(p, q, &newtbl->hash_buckets[i]) 384 tbl->free_node(p, 0); 385 } 386 __mesh_table_free(tbl); 387 endgrow: 388 return NULL; 389 } 390 391 /** 392 * ieee80211_new_mesh_header - create a new mesh header 393 * @meshhdr: uninitialized mesh header 394 * @sdata: mesh interface to be used 395 * 396 * Return the header length. 397 */ 398 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr, 399 struct ieee80211_sub_if_data *sdata) 400 { 401 meshhdr->flags = 0; 402 meshhdr->ttl = sdata->u.sta.mshcfg.dot11MeshTTL; 403 put_unaligned(cpu_to_le32(sdata->u.sta.mesh_seqnum), &meshhdr->seqnum); 404 sdata->u.sta.mesh_seqnum++; 405 406 return 6; 407 } 408 409 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata) 410 { 411 struct ieee80211_if_sta *ifsta = &sdata->u.sta; 412 413 ifsta->mshcfg.dot11MeshRetryTimeout = MESH_RET_T; 414 ifsta->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T; 415 ifsta->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T; 416 ifsta->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR; 417 ifsta->mshcfg.dot11MeshTTL = MESH_TTL; 418 ifsta->mshcfg.auto_open_plinks = true; 419 ifsta->mshcfg.dot11MeshMaxPeerLinks = 420 MESH_MAX_ESTAB_PLINKS; 421 ifsta->mshcfg.dot11MeshHWMPactivePathTimeout = 422 MESH_PATH_TIMEOUT; 423 ifsta->mshcfg.dot11MeshHWMPpreqMinInterval = 424 MESH_PREQ_MIN_INT; 425 ifsta->mshcfg.dot11MeshHWMPnetDiameterTraversalTime = 426 MESH_DIAM_TRAVERSAL_TIME; 427 ifsta->mshcfg.dot11MeshHWMPmaxPREQretries = 428 MESH_MAX_PREQ_RETRIES; 429 ifsta->mshcfg.path_refresh_time = 430 MESH_PATH_REFRESH_TIME; 431 ifsta->mshcfg.min_discovery_timeout = 432 MESH_MIN_DISCOVERY_TIMEOUT; 433 ifsta->accepting_plinks = true; 434 ifsta->preq_id = 0; 435 ifsta->dsn = 0; 436 atomic_set(&ifsta->mpaths, 0); 437 mesh_rmc_init(sdata->dev); 438 ifsta->last_preq = jiffies; 439 /* Allocate all mesh structures when creating the first mesh interface. */ 440 if (!mesh_allocated) 441 ieee80211s_init(); 442 mesh_ids_set_default(ifsta); 443 setup_timer(&ifsta->mesh_path_timer, 444 ieee80211_mesh_path_timer, 445 (unsigned long) sdata); 446 INIT_LIST_HEAD(&ifsta->preq_queue.list); 447 spin_lock_init(&ifsta->mesh_preq_queue_lock); 448 } 449