net/mac80211/mesh.c

   1 /*
   2  * Copyright (c) 2008, 2009 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 IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
  16 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
  17 #define IEEE80211_MESH_RANN_INTERVAL         (1 * HZ)
  18
  19 #define MESHCONF_CAPAB_ACCEPT_PLINKS 0x01
  20 #define MESHCONF_CAPAB_FORWARDING    0x08
  21
  22 #define TMR_RUNNING_HK  0
  23 #define TMR_RUNNING_MP  1
  24 #define TMR_RUNNING_MPR 2
  25
  26 int mesh_allocated;
  27 static struct kmem_cache *rm_cache;
  28
  29 void ieee80211s_init(void)
  30 {
  31         mesh_pathtbl_init();
  32         mesh_allocated = 1;
  33         rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
  34                                      0, 0, NULL);
  35 }
  36
  37 void ieee80211s_stop(void)
  38 {
  39         mesh_pathtbl_unregister();
  40         kmem_cache_destroy(rm_cache);
  41 }
  42
  43 static void ieee80211_mesh_housekeeping_timer(unsigned long data)
  44 {
  45         struct ieee80211_sub_if_data *sdata = (void *) data;
  46         struct ieee80211_local *local = sdata->local;
  47         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  48
  49         set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
  50
  51         if (local->quiescing) {
  52                 set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
  53                 return;
  54         }
  55
  56         ieee80211_queue_work(&local->hw, &ifmsh->work);
  57 }
  58
  59 /**
  60  * mesh_matches_local - check if the config of a mesh point matches ours
  61  *
  62  * @ie: information elements of a management frame from the mesh peer
  63  * @sdata: local mesh subif
  64  *
  65  * This function checks if the mesh configuration of a mesh point matches the
  66  * local mesh configuration, i.e. if both nodes belong to the same mesh network.
  67  */
  68 bool mesh_matches_local(struct ieee802_11_elems *ie, struct ieee80211_sub_if_data *sdata)
  69 {
  70         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  71
  72         /*
  73          * As support for each feature is added, check for matching
  74          * - On mesh config capabilities
  75          *   - Power Save Support En
  76          *   - Sync support enabled
  77          *   - Sync support active
  78          *   - Sync support required from peer
  79          *   - MDA enabled
  80          * - Power management control on fc
  81          */
  82         if (ifmsh->mesh_id_len == ie->mesh_id_len &&
  83                 memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
  84                 (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
  85                 (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
  86                 (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
  87                 (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
  88                 (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth))
  89                 return true;
  90
  91         return false;
  92 }
  93
  94 /**
  95  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
  96  *
  97  * @ie: information elements of a management frame from the mesh peer
  98  */
  99 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
 100 {
 101         return (ie->mesh_config->meshconf_cap &
 102             MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
 103 }
 104
 105 /**
 106  * mesh_accept_plinks_update: update accepting_plink in local mesh beacons
 107  *
 108  * @sdata: mesh interface in which mesh beacons are going to be updated
 109  */
 110 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
 111 {
 112         bool free_plinks;
 113
 114         /* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
 115          * the mesh interface might be able to establish plinks with peers that
 116          * are already on the table but are not on PLINK_ESTAB state. However,
 117          * in general the mesh interface is not accepting peer link requests
 118          * from new peers, and that must be reflected in the beacon
 119          */
 120         free_plinks = mesh_plink_availables(sdata);
 121
 122         if (free_plinks != sdata->u.mesh.accepting_plinks)
 123                 ieee80211_mesh_housekeeping_timer((unsigned long) sdata);
 124 }
 125
 126 void mesh_ids_set_default(struct ieee80211_if_mesh *sta)
 127 {
 128         sta->mesh_pp_id = 0;    /* HWMP */
 129         sta->mesh_pm_id = 0;    /* Airtime */
 130         sta->mesh_cc_id = 0;    /* Disabled */
 131         sta->mesh_sp_id = 0;    /* Neighbor Offset */
 132         sta->mesh_auth_id = 0;  /* Disabled */
 133 }
 134
 135 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
 136 {
 137         int i;
 138
 139         sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
 140         if (!sdata->u.mesh.rmc)
 141                 return -ENOMEM;
 142         sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
 143         for (i = 0; i < RMC_BUCKETS; i++)
 144                 INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i].list);
 145         return 0;
 146 }
 147
 148 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
 149 {
 150         struct mesh_rmc *rmc = sdata->u.mesh.rmc;
 151         struct rmc_entry *p, *n;
 152         int i;
 153
 154         if (!sdata->u.mesh.rmc)
 155                 return;
 156
 157         for (i = 0; i < RMC_BUCKETS; i++)
 158                 list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) {
 159                         list_del(&p->list);
 160                         kmem_cache_free(rm_cache, p);
 161                 }
 162
 163         kfree(rmc);
 164         sdata->u.mesh.rmc = NULL;
 165 }
 166
 167 /**
 168  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
 169  *
 170  * @sa:         source address
 171  * @mesh_hdr:   mesh_header
 172  *
 173  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
 174  *
 175  * Checks using the source address and the mesh sequence number if we have
 176  * received this frame lately. If the frame is not in the cache, it is added to
 177  * it.
 178  */
 179 int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
 180                    struct ieee80211_sub_if_data *sdata)
 181 {
 182         struct mesh_rmc *rmc = sdata->u.mesh.rmc;
 183         u32 seqnum = 0;
 184         int entries = 0;
 185         u8 idx;
 186         struct rmc_entry *p, *n;
 187
 188         /* Don't care about endianness since only match matters */
 189         memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
 190         idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
 191         list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) {
 192                 ++entries;
 193                 if (time_after(jiffies, p->exp_time) ||
 194                                 (entries == RMC_QUEUE_MAX_LEN)) {
 195                         list_del(&p->list);
 196                         kmem_cache_free(rm_cache, p);
 197                         --entries;
 198                 } else if ((seqnum == p->seqnum) &&
 199                            (memcmp(sa, p->sa, ETH_ALEN) == 0))
 200                         return -1;
 201         }
 202
 203         p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
 204         if (!p) {
 205                 printk(KERN_DEBUG "o11s: could not allocate RMC entry\n");
 206                 return 0;
 207         }
 208         p->seqnum = seqnum;
 209         p->exp_time = jiffies + RMC_TIMEOUT;
 210         memcpy(p->sa, sa, ETH_ALEN);
 211         list_add(&p->list, &rmc->bucket[idx].list);
 212         return 0;
 213 }
 214
 215 void mesh_mgmt_ies_add(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
 216 {
 217         struct ieee80211_local *local = sdata->local;
 218         struct ieee80211_supported_band *sband;
 219         u8 *pos;
 220         int len, i, rate;
 221         u8 neighbors;
 222
 223         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 224         len = sband->n_bitrates;
 225         if (len > 8)
 226                 len = 8;
 227         pos = skb_put(skb, len + 2);
 228         *pos++ = WLAN_EID_SUPP_RATES;
 229         *pos++ = len;
 230         for (i = 0; i < len; i++) {
 231                 rate = sband->bitrates[i].bitrate;
 232                 *pos++ = (u8) (rate / 5);
 233         }
 234
 235         if (sband->n_bitrates > len) {
 236                 pos = skb_put(skb, sband->n_bitrates - len + 2);
 237                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 238                 *pos++ = sband->n_bitrates - len;
 239                 for (i = len; i < sband->n_bitrates; i++) {
 240                         rate = sband->bitrates[i].bitrate;
 241                         *pos++ = (u8) (rate / 5);
 242                 }
 243         }
 244
 245         if (sband->band == IEEE80211_BAND_2GHZ) {
 246                 pos = skb_put(skb, 2 + 1);
 247                 *pos++ = WLAN_EID_DS_PARAMS;
 248                 *pos++ = 1;
 249                 *pos++ = ieee80211_frequency_to_channel(local->hw.conf.channel->center_freq);
 250         }
 251
 252         pos = skb_put(skb, 2 + sdata->u.mesh.mesh_id_len);
 253         *pos++ = WLAN_EID_MESH_ID;
 254         *pos++ = sdata->u.mesh.mesh_id_len;
 255         if (sdata->u.mesh.mesh_id_len)
 256                 memcpy(pos, sdata->u.mesh.mesh_id, sdata->u.mesh.mesh_id_len);
 257
 258         pos = skb_put(skb, 2 + sizeof(struct ieee80211_meshconf_ie));
 259         *pos++ = WLAN_EID_MESH_CONFIG;
 260         *pos++ = sizeof(struct ieee80211_meshconf_ie);
 261
 262         /* Active path selection protocol ID */
 263         *pos++ = sdata->u.mesh.mesh_pp_id;
 264
 265         /* Active path selection metric ID   */
 266         *pos++ = sdata->u.mesh.mesh_pm_id;
 267
 268         /* Congestion control mode identifier */
 269         *pos++ = sdata->u.mesh.mesh_cc_id;
 270
 271         /* Synchronization protocol identifier */
 272         *pos++ = sdata->u.mesh.mesh_sp_id;
 273
 274         /* Authentication Protocol identifier */
 275         *pos++ = sdata->u.mesh.mesh_auth_id;
 276
 277         /* Mesh Formation Info - number of neighbors */
 278         neighbors = atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 279         /* Number of neighbor mesh STAs or 15 whichever is smaller */
 280         neighbors = (neighbors > 15) ? 15 : neighbors;
 281         *pos++ = neighbors << 1;
 282
 283         /* Mesh capability */
 284         sdata->u.mesh.accepting_plinks = mesh_plink_availables(sdata);
 285         *pos = MESHCONF_CAPAB_FORWARDING;
 286         *pos++ |= sdata->u.mesh.accepting_plinks ?
 287             MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
 288         *pos++ = 0x00;
 289
 290         return;
 291 }
 292
 293 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata, struct mesh_table *tbl)
 294 {
 295         /* Use last four bytes of hw addr and interface index as hash index */
 296         return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd)
 297                 & tbl->hash_mask;
 298 }
 299
 300 struct mesh_table *mesh_table_alloc(int size_order)
 301 {
 302         int i;
 303         struct mesh_table *newtbl;
 304
 305         newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL);
 306         if (!newtbl)
 307                 return NULL;
 308
 309         newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
 310                         (1 << size_order), GFP_KERNEL);
 311
 312         if (!newtbl->hash_buckets) {
 313                 kfree(newtbl);
 314                 return NULL;
 315         }
 316
 317         newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
 318                         (1 << size_order), GFP_KERNEL);
 319         if (!newtbl->hashwlock) {
 320                 kfree(newtbl->hash_buckets);
 321                 kfree(newtbl);
 322                 return NULL;
 323         }
 324
 325         newtbl->size_order = size_order;
 326         newtbl->hash_mask = (1 << size_order) - 1;
 327         atomic_set(&newtbl->entries,  0);
 328         get_random_bytes(&newtbl->hash_rnd,
 329                         sizeof(newtbl->hash_rnd));
 330         for (i = 0; i <= newtbl->hash_mask; i++)
 331                 spin_lock_init(&newtbl->hashwlock[i]);
 332
 333         return newtbl;
 334 }
 335
 336
 337 static void ieee80211_mesh_path_timer(unsigned long data)
 338 {
 339         struct ieee80211_sub_if_data *sdata =
 340                 (struct ieee80211_sub_if_data *) data;
 341         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 342         struct ieee80211_local *local = sdata->local;
 343
 344         if (local->quiescing) {
 345                 set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
 346                 return;
 347         }
 348
 349         ieee80211_queue_work(&local->hw, &ifmsh->work);
 350 }
 351
 352 static void ieee80211_mesh_path_root_timer(unsigned long data)
 353 {
 354         struct ieee80211_sub_if_data *sdata =
 355                 (struct ieee80211_sub_if_data *) data;
 356         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 357         struct ieee80211_local *local = sdata->local;
 358
 359         set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
 360
 361         if (local->quiescing) {
 362                 set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
 363                 return;
 364         }
 365
 366         ieee80211_queue_work(&local->hw, &ifmsh->work);
 367 }
 368
 369 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
 370 {
 371         if (ifmsh->mshcfg.dot11MeshHWMPRootMode)
 372                 set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
 373         else {
 374                 clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
 375                 /* stop running timer */
 376                 del_timer_sync(&ifmsh->mesh_path_root_timer);
 377         }
 378 }
 379
 380 /**
 381  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
 382  * @hdr:        802.11 frame header
 383  * @fc:         frame control field
 384  * @meshda:     destination address in the mesh
 385  * @meshsa:     source address address in the mesh.  Same as TA, as frame is
 386  *              locally originated.
 387  *
 388  * Return the length of the 802.11 (does not include a mesh control header)
 389  */
 390 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 391                                   const u8 *meshda, const u8 *meshsa)
 392 {
 393         if (is_multicast_ether_addr(meshda)) {
 394                 *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
 395                 /* DA TA SA */
 396                 memcpy(hdr->addr1, meshda, ETH_ALEN);
 397                 memcpy(hdr->addr2, meshsa, ETH_ALEN);
 398                 memcpy(hdr->addr3, meshsa, ETH_ALEN);
 399                 return 24;
 400         } else {
 401                 *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
 402                                 IEEE80211_FCTL_TODS);
 403                 /* RA TA DA SA */
 404                 memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */
 405                 memcpy(hdr->addr2, meshsa, ETH_ALEN);
 406                 memcpy(hdr->addr3, meshda, ETH_ALEN);
 407                 memcpy(hdr->addr4, meshsa, ETH_ALEN);
 408                 return 30;
 409         }
 410 }
 411
 412 /**
 413  * ieee80211_new_mesh_header - create a new mesh header
 414  * @meshhdr:    uninitialized mesh header
 415  * @sdata:      mesh interface to be used
 416  * @addr4:      addr4 of the mesh frame (1st in ae header)
 417  *              may be NULL
 418  * @addr5:      addr5 of the mesh frame (1st or 2nd in ae header)
 419  *              may be NULL unless addr6 is present
 420  * @addr6:      addr6 of the mesh frame (2nd or 3rd in ae header)
 421  *              may be NULL unless addr5 is present
 422  *
 423  * Return the header length.
 424  */
 425 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 426                 struct ieee80211_sub_if_data *sdata, char *addr4,
 427                 char *addr5, char *addr6)
 428 {
 429         int aelen = 0;
 430         memset(meshhdr, 0, sizeof(*meshhdr));
 431         meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
 432         put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
 433         sdata->u.mesh.mesh_seqnum++;
 434         if (addr4) {
 435                 meshhdr->flags |= MESH_FLAGS_AE_A4;
 436                 aelen += ETH_ALEN;
 437                 memcpy(meshhdr->eaddr1, addr4, ETH_ALEN);
 438         }
 439         if (addr5 && addr6) {
 440                 meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
 441                 aelen += 2 * ETH_ALEN;
 442                 if (!addr4) {
 443                         memcpy(meshhdr->eaddr1, addr5, ETH_ALEN);
 444                         memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
 445                 } else {
 446                         memcpy(meshhdr->eaddr2, addr5, ETH_ALEN);
 447                         memcpy(meshhdr->eaddr3, addr6, ETH_ALEN);
 448                 }
 449         }
 450         return 6 + aelen;
 451 }
 452
 453 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata,
 454                            struct ieee80211_if_mesh *ifmsh)
 455 {
 456         bool free_plinks;
 457
 458 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 459         printk(KERN_DEBUG "%s: running mesh housekeeping\n",
 460                sdata->name);
 461 #endif
 462
 463         ieee80211_sta_expire(sdata, IEEE80211_MESH_PEER_INACTIVITY_LIMIT);
 464         mesh_path_expire(sdata);
 465
 466         free_plinks = mesh_plink_availables(sdata);
 467         if (free_plinks != sdata->u.mesh.accepting_plinks)
 468                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 469
 470         mod_timer(&ifmsh->housekeeping_timer,
 471                   round_jiffies(jiffies + IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
 472 }
 473
 474 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
 475 {
 476         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 477
 478         mesh_path_tx_root_frame(sdata);
 479         mod_timer(&ifmsh->mesh_path_root_timer,
 480                   round_jiffies(jiffies + IEEE80211_MESH_RANN_INTERVAL));
 481 }
 482
 483 #ifdef CONFIG_PM
 484 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 485 {
 486         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 487
 488         /* might restart the timer but that doesn't matter */
 489         cancel_work_sync(&ifmsh->work);
 490
 491         /* use atomic bitops in case both timers fire at the same time */
 492
 493         if (del_timer_sync(&ifmsh->housekeeping_timer))
 494                 set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
 495         if (del_timer_sync(&ifmsh->mesh_path_timer))
 496                 set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
 497         if (del_timer_sync(&ifmsh->mesh_path_root_timer))
 498                 set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
 499 }
 500
 501 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 502 {
 503         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 504
 505         if (test_and_clear_bit(TMR_RUNNING_HK, &ifmsh->timers_running))
 506                 add_timer(&ifmsh->housekeeping_timer);
 507         if (test_and_clear_bit(TMR_RUNNING_MP, &ifmsh->timers_running))
 508                 add_timer(&ifmsh->mesh_path_timer);
 509         if (test_and_clear_bit(TMR_RUNNING_MPR, &ifmsh->timers_running))
 510                 add_timer(&ifmsh->mesh_path_root_timer);
 511         ieee80211_mesh_root_setup(ifmsh);
 512 }
 513 #endif
 514
 515 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
 516 {
 517         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 518         struct ieee80211_local *local = sdata->local;
 519
 520         set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
 521         ieee80211_mesh_root_setup(ifmsh);
 522         ieee80211_queue_work(&local->hw, &ifmsh->work);
 523         sdata->vif.bss_conf.beacon_int = MESH_DEFAULT_BEACON_INTERVAL;
 524         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON |
 525                                                 BSS_CHANGED_BEACON_ENABLED |
 526                                                 BSS_CHANGED_BEACON_INT);
 527 }
 528
 529 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
 530 {
 531         del_timer_sync(&sdata->u.mesh.housekeeping_timer);
 532         del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
 533         /*
 534          * If the timer fired while we waited for it, it will have
 535          * requeued the work. Now the work will be running again
 536          * but will not rearm the timer again because it checks
 537          * whether the interface is running, which, at this point,
 538          * it no longer is.
 539          */
 540         cancel_work_sync(&sdata->u.mesh.work);
 541
 542         /*
 543          * When we get here, the interface is marked down.
 544          * Call synchronize_rcu() to wait for the RX path
 545          * should it be using the interface and enqueuing
 546          * frames at this very time on another CPU.
 547          */
 548         rcu_barrier(); /* Wait for RX path and call_rcu()'s */
 549         skb_queue_purge(&sdata->u.mesh.skb_queue);
 550 }
 551
 552 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 553                                         u16 stype,
 554                                         struct ieee80211_mgmt *mgmt,
 555                                         size_t len,
 556                                         struct ieee80211_rx_status *rx_status)
 557 {
 558         struct ieee80211_local *local = sdata->local;
 559         struct ieee802_11_elems elems;
 560         struct ieee80211_channel *channel;
 561         u32 supp_rates = 0;
 562         size_t baselen;
 563         int freq;
 564         enum ieee80211_band band = rx_status->band;
 565
 566         /* ignore ProbeResp to foreign address */
 567         if (stype == IEEE80211_STYPE_PROBE_RESP &&
 568             compare_ether_addr(mgmt->da, sdata->vif.addr))
 569                 return;
 570
 571         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 572         if (baselen > len)
 573                 return;
 574
 575         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 576                                &elems);
 577
 578         if (elems.ds_params && elems.ds_params_len == 1)
 579                 freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
 580         else
 581                 freq = rx_status->freq;
 582
 583         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 584
 585         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 586                 return;
 587
 588         if (elems.mesh_id && elems.mesh_config &&
 589             mesh_matches_local(&elems, sdata)) {
 590                 supp_rates = ieee80211_sta_get_rates(local, &elems, band);
 591
 592                 mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
 593                                       mesh_peer_accepts_plinks(&elems));
 594         }
 595 }
 596
 597 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
 598                                           struct ieee80211_mgmt *mgmt,
 599                                           size_t len,
 600                                           struct ieee80211_rx_status *rx_status)
 601 {
 602         switch (mgmt->u.action.category) {
 603         case MESH_PLINK_CATEGORY:
 604                 mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
 605                 break;
 606         case MESH_PATH_SEL_CATEGORY:
 607                 mesh_rx_path_sel_frame(sdata, mgmt, len);
 608                 break;
 609         }
 610 }
 611
 612 static void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 613                                           struct sk_buff *skb)
 614 {
 615         struct ieee80211_rx_status *rx_status;
 616         struct ieee80211_if_mesh *ifmsh;
 617         struct ieee80211_mgmt *mgmt;
 618         u16 stype;
 619
 620         ifmsh = &sdata->u.mesh;
 621
 622         rx_status = IEEE80211_SKB_RXCB(skb);
 623         mgmt = (struct ieee80211_mgmt *) skb->data;
 624         stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
 625
 626         switch (stype) {
 627         case IEEE80211_STYPE_PROBE_RESP:
 628         case IEEE80211_STYPE_BEACON:
 629                 ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
 630                                             rx_status);
 631                 break;
 632         case IEEE80211_STYPE_ACTION:
 633                 ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
 634                 break;
 635         }
 636
 637         kfree_skb(skb);
 638 }
 639
 640 static void ieee80211_mesh_work(struct work_struct *work)
 641 {
 642         struct ieee80211_sub_if_data *sdata =
 643                 container_of(work, struct ieee80211_sub_if_data, u.mesh.work);
 644         struct ieee80211_local *local = sdata->local;
 645         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 646         struct sk_buff *skb;
 647
 648         if (!netif_running(sdata->dev))
 649                 return;
 650
 651         if (local->scanning)
 652                 return;
 653
 654         while ((skb = skb_dequeue(&ifmsh->skb_queue)))
 655                 ieee80211_mesh_rx_queued_mgmt(sdata, skb);
 656
 657         if (ifmsh->preq_queue_len &&
 658             time_after(jiffies,
 659                        ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
 660                 mesh_path_start_discovery(sdata);
 661
 662         if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
 663                 mesh_mpath_table_grow();
 664
 665         if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
 666                 mesh_mpp_table_grow();
 667
 668         if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
 669                 ieee80211_mesh_housekeeping(sdata, ifmsh);
 670
 671         if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
 672                 ieee80211_mesh_rootpath(sdata);
 673 }
 674
 675 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
 676 {
 677         struct ieee80211_sub_if_data *sdata;
 678
 679         rcu_read_lock();
 680         list_for_each_entry_rcu(sdata, &local->interfaces, list)
 681                 if (ieee80211_vif_is_mesh(&sdata->vif))
 682                         ieee80211_queue_work(&local->hw, &sdata->u.mesh.work);
 683         rcu_read_unlock();
 684 }
 685
 686 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
 687 {
 688         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 689
 690         INIT_WORK(&ifmsh->work, ieee80211_mesh_work);
 691         setup_timer(&ifmsh->housekeeping_timer,
 692                     ieee80211_mesh_housekeeping_timer,
 693                     (unsigned long) sdata);
 694         skb_queue_head_init(&sdata->u.mesh.skb_queue);
 695
 696         ifmsh->mshcfg.dot11MeshRetryTimeout = MESH_RET_T;
 697         ifmsh->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T;
 698         ifmsh->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T;
 699         ifmsh->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR;
 700         ifmsh->mshcfg.dot11MeshTTL = MESH_TTL;
 701         ifmsh->mshcfg.auto_open_plinks = true;
 702         ifmsh->mshcfg.dot11MeshMaxPeerLinks =
 703                 MESH_MAX_ESTAB_PLINKS;
 704         ifmsh->mshcfg.dot11MeshHWMPactivePathTimeout =
 705                 MESH_PATH_TIMEOUT;
 706         ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval =
 707                 MESH_PREQ_MIN_INT;
 708         ifmsh->mshcfg.dot11MeshHWMPnetDiameterTraversalTime =
 709                 MESH_DIAM_TRAVERSAL_TIME;
 710         ifmsh->mshcfg.dot11MeshHWMPmaxPREQretries =
 711                 MESH_MAX_PREQ_RETRIES;
 712         ifmsh->mshcfg.path_refresh_time =
 713                 MESH_PATH_REFRESH_TIME;
 714         ifmsh->mshcfg.min_discovery_timeout =
 715                 MESH_MIN_DISCOVERY_TIMEOUT;
 716         ifmsh->accepting_plinks = true;
 717         ifmsh->preq_id = 0;
 718         ifmsh->sn = 0;
 719         atomic_set(&ifmsh->mpaths, 0);
 720         mesh_rmc_init(sdata);
 721         ifmsh->last_preq = jiffies;
 722         /* Allocate all mesh structures when creating the first mesh interface. */
 723         if (!mesh_allocated)
 724                 ieee80211s_init();
 725         mesh_ids_set_default(ifmsh);
 726         setup_timer(&ifmsh->mesh_path_timer,
 727                     ieee80211_mesh_path_timer,
 728                     (unsigned long) sdata);
 729         setup_timer(&ifmsh->mesh_path_root_timer,
 730                     ieee80211_mesh_path_root_timer,
 731                     (unsigned long) sdata);
 732         INIT_LIST_HEAD(&ifmsh->preq_queue.list);
 733         spin_lock_init(&ifmsh->mesh_preq_queue_lock);
 734 }
 735
 736 ieee80211_rx_result
 737 ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 738 {
 739         struct ieee80211_local *local = sdata->local;
 740         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 741         struct ieee80211_mgmt *mgmt;
 742         u16 fc;
 743
 744         if (skb->len < 24)
 745                 return RX_DROP_MONITOR;
 746
 747         mgmt = (struct ieee80211_mgmt *) skb->data;
 748         fc = le16_to_cpu(mgmt->frame_control);
 749
 750         switch (fc & IEEE80211_FCTL_STYPE) {
 751         case IEEE80211_STYPE_ACTION:
 752                 if (skb->len < IEEE80211_MIN_ACTION_SIZE)
 753                         return RX_DROP_MONITOR;
 754                 /* fall through */
 755         case IEEE80211_STYPE_PROBE_RESP:
 756         case IEEE80211_STYPE_BEACON:
 757                 skb_queue_tail(&ifmsh->skb_queue, skb);
 758                 ieee80211_queue_work(&local->hw, &ifmsh->work);
 759                 return RX_QUEUED;
 760         }
 761
 762         return RX_CONTINUE;
 763 }