net/mac80211/mesh.c

   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 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_PP_OFFSET      0               /* Path Selection Protocol */
  20 #define MESHCONF_PM_OFFSET      1               /* Path Selection Metric   */
  21 #define MESHCONF_CC_OFFSET      2               /* Congestion Control Mode */
  22 #define MESHCONF_SP_OFFSET      3               /* Synchronization Protocol */
  23 #define MESHCONF_AUTH_OFFSET    4               /* Authentication Protocol */
  24 #define MESHCONF_CAPAB_OFFSET   6
  25 #define MESHCONF_CAPAB_ACCEPT_PLINKS 0x01
  26 #define MESHCONF_CAPAB_FORWARDING    0x08
  27
  28 #define TMR_RUNNING_HK  0
  29 #define TMR_RUNNING_MP  1
  30 #define TMR_RUNNING_MPR 2
  31
  32 int mesh_allocated;
  33 static struct kmem_cache *rm_cache;
  34
  35 void ieee80211s_init(void)
  36 {
  37         mesh_pathtbl_init();
  38         mesh_allocated = 1;
  39         rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
  40                                      0, 0, NULL);
  41 }
  42
  43 void ieee80211s_stop(void)
  44 {
  45         mesh_pathtbl_unregister();
  46         kmem_cache_destroy(rm_cache);
  47 }
  48
  49 static void ieee80211_mesh_housekeeping_timer(unsigned long data)
  50 {
  51         struct ieee80211_sub_if_data *sdata = (void *) data;
  52         struct ieee80211_local *local = sdata->local;
  53         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  54
  55         set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
  56
  57         if (local->quiescing) {
  58                 set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
  59                 return;
  60         }
  61
  62         ieee80211_queue_work(&local->hw, &ifmsh->work);
  63 }
  64
  65 /**
  66  * mesh_matches_local - check if the config of a mesh point matches ours
  67  *
  68  * @ie: information elements of a management frame from the mesh peer
  69  * @sdata: local mesh subif
  70  *
  71  * This function checks if the mesh configuration of a mesh point matches the
  72  * local mesh configuration, i.e. if both nodes belong to the same mesh network.
  73  */
  74 bool mesh_matches_local(struct ieee802_11_elems *ie, struct ieee80211_sub_if_data *sdata)
  75 {
  76         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  77
  78         /*
  79          * As support for each feature is added, check for matching
  80          * - On mesh config capabilities
  81          *   - Power Save Support En
  82          *   - Sync support enabled
  83          *   - Sync support active
  84          *   - Sync support required from peer
  85          *   - MDA enabled
  86          * - Power management control on fc
  87          */
  88         if (ifmsh->mesh_id_len == ie->mesh_id_len &&
  89                 memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
  90                 (ifmsh->mesh_pp_id == *(ie->mesh_config + MESHCONF_PP_OFFSET))&&
  91                 (ifmsh->mesh_pm_id == *(ie->mesh_config + MESHCONF_PM_OFFSET))&&
  92                 (ifmsh->mesh_cc_id == *(ie->mesh_config + MESHCONF_CC_OFFSET))&&
  93                 (ifmsh->mesh_sp_id == *(ie->mesh_config + MESHCONF_SP_OFFSET))&&
  94                 (ifmsh->mesh_auth_id == *(ie->mesh_config +
  95                     MESHCONF_AUTH_OFFSET)))
  96                 return true;
  97
  98         return false;
  99 }
 100
 101 /**
 102  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
 103  *
 104  * @ie: information elements of a management frame from the mesh peer
 105  */
 106 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
 107 {
 108         return (*(ie->mesh_config + MESHCONF_CAPAB_OFFSET) &
 109             MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
 110 }
 111
 112 /**
 113  * mesh_accept_plinks_update: update accepting_plink in local mesh beacons
 114  *
 115  * @sdata: mesh interface in which mesh beacons are going to be updated
 116  */
 117 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
 118 {
 119         bool free_plinks;
 120
 121         /* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
 122          * the mesh interface might be able to establish plinks with peers that
 123          * are already on the table but are not on PLINK_ESTAB state. However,
 124          * in general the mesh interface is not accepting peer link requests
 125          * from new peers, and that must be reflected in the beacon
 126          */
 127         free_plinks = mesh_plink_availables(sdata);
 128
 129         if (free_plinks != sdata->u.mesh.accepting_plinks)
 130                 ieee80211_mesh_housekeeping_timer((unsigned long) sdata);
 131 }
 132
 133 void mesh_ids_set_default(struct ieee80211_if_mesh *sta)
 134 {
 135         sta->mesh_pp_id = 0;    /* HWMP */
 136         sta->mesh_pm_id = 0;    /* Airtime */
 137         sta->mesh_cc_id = 0;    /* Disabled */
 138         sta->mesh_sp_id = 0;    /* Neighbor Offset */
 139         sta->mesh_auth_id = 0;  /* Disabled */
 140 }
 141
 142 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
 143 {
 144         int i;
 145
 146         sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
 147         if (!sdata->u.mesh.rmc)
 148                 return -ENOMEM;
 149         sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
 150         for (i = 0; i < RMC_BUCKETS; i++)
 151                 INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i].list);
 152         return 0;
 153 }
 154
 155 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
 156 {
 157         struct mesh_rmc *rmc = sdata->u.mesh.rmc;
 158         struct rmc_entry *p, *n;
 159         int i;
 160
 161         if (!sdata->u.mesh.rmc)
 162                 return;
 163
 164         for (i = 0; i < RMC_BUCKETS; i++)
 165                 list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) {
 166                         list_del(&p->list);
 167                         kmem_cache_free(rm_cache, p);
 168                 }
 169
 170         kfree(rmc);
 171         sdata->u.mesh.rmc = NULL;
 172 }
 173
 174 /**
 175  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
 176  *
 177  * @sa:         source address
 178  * @mesh_hdr:   mesh_header
 179  *
 180  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
 181  *
 182  * Checks using the source address and the mesh sequence number if we have
 183  * received this frame lately. If the frame is not in the cache, it is added to
 184  * it.
 185  */
 186 int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
 187                    struct ieee80211_sub_if_data *sdata)
 188 {
 189         struct mesh_rmc *rmc = sdata->u.mesh.rmc;
 190         u32 seqnum = 0;
 191         int entries = 0;
 192         u8 idx;
 193         struct rmc_entry *p, *n;
 194
 195         /* Don't care about endianness since only match matters */
 196         memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
 197         idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
 198         list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) {
 199                 ++entries;
 200                 if (time_after(jiffies, p->exp_time) ||
 201                                 (entries == RMC_QUEUE_MAX_LEN)) {
 202                         list_del(&p->list);
 203                         kmem_cache_free(rm_cache, p);
 204                         --entries;
 205                 } else if ((seqnum == p->seqnum)
 206                                 && (memcmp(sa, p->sa, ETH_ALEN) == 0))
 207                         return -1;
 208         }
 209
 210         p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
 211         if (!p) {
 212                 printk(KERN_DEBUG "o11s: could not allocate RMC entry\n");
 213                 return 0;
 214         }
 215         p->seqnum = seqnum;
 216         p->exp_time = jiffies + RMC_TIMEOUT;
 217         memcpy(p->sa, sa, ETH_ALEN);
 218         list_add(&p->list, &rmc->bucket[idx].list);
 219         return 0;
 220 }
 221
 222 void mesh_mgmt_ies_add(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
 223 {
 224         struct ieee80211_local *local = sdata->local;
 225         struct ieee80211_supported_band *sband;
 226         u8 *pos;
 227         int len, i, rate;
 228         u8 neighbors;
 229
 230         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 231         len = sband->n_bitrates;
 232         if (len > 8)
 233                 len = 8;
 234         pos = skb_put(skb, len + 2);
 235         *pos++ = WLAN_EID_SUPP_RATES;
 236         *pos++ = len;
 237         for (i = 0; i < len; i++) {
 238                 rate = sband->bitrates[i].bitrate;
 239                 *pos++ = (u8) (rate / 5);
 240         }
 241
 242         if (sband->n_bitrates > len) {
 243                 pos = skb_put(skb, sband->n_bitrates - len + 2);
 244                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 245                 *pos++ = sband->n_bitrates - len;
 246                 for (i = len; i < sband->n_bitrates; i++) {
 247                         rate = sband->bitrates[i].bitrate;
 248                         *pos++ = (u8) (rate / 5);
 249                 }
 250         }
 251
 252         if (sband->band == IEEE80211_BAND_2GHZ) {
 253                 pos = skb_put(skb, 2 + 1);
 254                 *pos++ = WLAN_EID_DS_PARAMS;
 255                 *pos++ = 1;
 256                 *pos++ = ieee80211_frequency_to_channel(local->hw.conf.channel->center_freq);
 257         }
 258
 259         pos = skb_put(skb, 2 + sdata->u.mesh.mesh_id_len);
 260         *pos++ = WLAN_EID_MESH_ID;
 261         *pos++ = sdata->u.mesh.mesh_id_len;
 262         if (sdata->u.mesh.mesh_id_len)
 263                 memcpy(pos, sdata->u.mesh.mesh_id, sdata->u.mesh.mesh_id_len);
 264
 265         pos = skb_put(skb, 2 + IEEE80211_MESH_CONFIG_LEN);
 266         *pos++ = WLAN_EID_MESH_CONFIG;
 267         *pos++ = IEEE80211_MESH_CONFIG_LEN;
 268
 269         /* Active path selection protocol ID */
 270         *pos++ = sdata->u.mesh.mesh_pp_id;
 271
 272         /* Active path selection metric ID   */
 273         *pos++ = sdata->u.mesh.mesh_pm_id;
 274
 275         /* Congestion control mode identifier */
 276         *pos++ = sdata->u.mesh.mesh_cc_id;
 277
 278         /* Synchronization protocol identifier */
 279         *pos++ = sdata->u.mesh.mesh_sp_id;
 280
 281         /* Authentication Protocol identifier */
 282         *pos++ = sdata->u.mesh.mesh_auth_id;
 283
 284         /* Mesh Formation Info - number of neighbors */
 285         neighbors = atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 286         /* Number of neighbor mesh STAs or 15 whichever is smaller */
 287         neighbors = (neighbors > 15) ? 15 : neighbors;
 288         *pos++ = neighbors << 1;
 289
 290         /* Mesh capability */
 291         sdata->u.mesh.accepting_plinks = mesh_plink_availables(sdata);
 292         *pos = MESHCONF_CAPAB_FORWARDING;
 293         *pos++ |= sdata->u.mesh.accepting_plinks ?
 294             MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
 295         *pos++ = 0x00;
 296
 297         return;
 298 }
 299
 300 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata, struct mesh_table *tbl)
 301 {
 302         /* Use last four bytes of hw addr and interface index as hash index */
 303         return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd)
 304                 & tbl->hash_mask;
 305 }
 306
 307 struct mesh_table *mesh_table_alloc(int size_order)
 308 {
 309         int i;
 310         struct mesh_table *newtbl;
 311
 312         newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL);
 313         if (!newtbl)
 314                 return NULL;
 315
 316         newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
 317                         (1 << size_order), GFP_KERNEL);
 318
 319         if (!newtbl->hash_buckets) {
 320                 kfree(newtbl);
 321                 return NULL;
 322         }
 323
 324         newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
 325                         (1 << size_order), GFP_KERNEL);
 326         if (!newtbl->hashwlock) {
 327                 kfree(newtbl->hash_buckets);
 328                 kfree(newtbl);
 329                 return NULL;
 330         }
 331
 332         newtbl->size_order = size_order;
 333         newtbl->hash_mask = (1 << size_order) - 1;
 334         atomic_set(&newtbl->entries,  0);
 335         get_random_bytes(&newtbl->hash_rnd,
 336                         sizeof(newtbl->hash_rnd));
 337         for (i = 0; i <= newtbl->hash_mask; i++)
 338                 spin_lock_init(&newtbl->hashwlock[i]);
 339
 340         return newtbl;
 341 }
 342
 343
 344 static void ieee80211_mesh_path_timer(unsigned long data)
 345 {
 346         struct ieee80211_sub_if_data *sdata =
 347                 (struct ieee80211_sub_if_data *) data;
 348         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 349         struct ieee80211_local *local = sdata->local;
 350
 351         if (local->quiescing) {
 352                 set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
 353                 return;
 354         }
 355
 356         ieee80211_queue_work(&local->hw, &ifmsh->work);
 357 }
 358
 359 static void ieee80211_mesh_path_root_timer(unsigned long data)
 360 {
 361         struct ieee80211_sub_if_data *sdata =
 362                 (struct ieee80211_sub_if_data *) data;
 363         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 364         struct ieee80211_local *local = sdata->local;
 365
 366         set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
 367
 368         if (local->quiescing) {
 369                 set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
 370                 return;
 371         }
 372
 373         ieee80211_queue_work(&local->hw, &ifmsh->work);
 374 }
 375
 376 /**
 377  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
 378  * @hdr:        802.11 frame header
 379  * @fc:         frame control field
 380  * @meshda:     destination address in the mesh
 381  * @meshsa:     source address address in the mesh.  Same as TA, as frame is
 382  *              locally originated.
 383  *
 384  * Return the length of the 802.11 (does not include a mesh control header)
 385  */
 386 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc, char
 387                 *meshda, char *meshsa) {
 388         if (is_multicast_ether_addr(meshda)) {
 389                 *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
 390                 /* DA TA SA */
 391                 memcpy(hdr->addr1, meshda, ETH_ALEN);
 392                 memcpy(hdr->addr2, meshsa, ETH_ALEN);
 393                 memcpy(hdr->addr3, meshsa, ETH_ALEN);
 394                 return 24;
 395         } else {
 396                 *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
 397                                 IEEE80211_FCTL_TODS);
 398                 /* RA TA DA SA */
 399                 memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */
 400                 memcpy(hdr->addr2, meshsa, ETH_ALEN);
 401                 memcpy(hdr->addr3, meshda, ETH_ALEN);
 402                 memcpy(hdr->addr4, meshsa, ETH_ALEN);
 403                 return 30;
 404         }
 405 }
 406
 407 /**
 408  * ieee80211_new_mesh_header - create a new mesh header
 409  * @meshhdr:    uninitialized mesh header
 410  * @sdata:      mesh interface to be used
 411  * @addr4:      addr4 of the mesh frame (1st in ae header)
 412  *              may be NULL
 413  * @addr5:      addr5 of the mesh frame (1st or 2nd in ae header)
 414  *              may be NULL unless addr6 is present
 415  * @addr6:      addr6 of the mesh frame (2nd or 3rd in ae header)
 416  *              may be NULL unless addr5 is present
 417  *
 418  * Return the header length.
 419  */
 420 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 421                 struct ieee80211_sub_if_data *sdata, char *addr4,
 422                 char *addr5, char *addr6)
 423 {
 424         int aelen = 0;
 425         memset(meshhdr, 0, sizeof(meshhdr));
 426         meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
 427         put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
 428         sdata->u.mesh.mesh_seqnum++;
 429         if (addr4) {
 430                 meshhdr->flags |= MESH_FLAGS_AE_A4;
 431                 aelen += ETH_ALEN;
 432                 memcpy(meshhdr->eaddr1, addr4, ETH_ALEN);
 433         }
 434         if (addr5 && addr6) {
 435                 meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
 436                 aelen += 2 * ETH_ALEN;
 437                 if (!addr4) {
 438                         memcpy(meshhdr->eaddr1, addr5, ETH_ALEN);
 439                         memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
 440                 } else {
 441                         memcpy(meshhdr->eaddr2, addr5, ETH_ALEN);
 442                         memcpy(meshhdr->eaddr3, addr6, ETH_ALEN);
 443                 }
 444         }
 445         return 6 + aelen;
 446 }
 447
 448 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata,
 449                            struct ieee80211_if_mesh *ifmsh)
 450 {
 451         bool free_plinks;
 452
 453 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 454         printk(KERN_DEBUG "%s: running mesh housekeeping\n",
 455                sdata->dev->name);
 456 #endif
 457
 458         ieee80211_sta_expire(sdata, IEEE80211_MESH_PEER_INACTIVITY_LIMIT);
 459         mesh_path_expire(sdata);
 460
 461         free_plinks = mesh_plink_availables(sdata);
 462         if (free_plinks != sdata->u.mesh.accepting_plinks)
 463                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 464
 465         mod_timer(&ifmsh->housekeeping_timer,
 466                   round_jiffies(jiffies + IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
 467 }
 468
 469 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
 470 {
 471         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 472
 473         mesh_path_tx_root_frame(sdata);
 474         mod_timer(&ifmsh->mesh_path_root_timer,
 475                   round_jiffies(jiffies + IEEE80211_MESH_RANN_INTERVAL));
 476 }
 477
 478 #ifdef CONFIG_PM
 479 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 480 {
 481         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 482
 483         /* might restart the timer but that doesn't matter */
 484         cancel_work_sync(&ifmsh->work);
 485
 486         /* use atomic bitops in case both timers fire at the same time */
 487
 488         if (del_timer_sync(&ifmsh->housekeeping_timer))
 489                 set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
 490         if (del_timer_sync(&ifmsh->mesh_path_timer))
 491                 set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
 492         if (del_timer_sync(&ifmsh->mesh_path_root_timer))
 493                 set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
 494 }
 495
 496 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 497 {
 498         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 499
 500         if (test_and_clear_bit(TMR_RUNNING_HK, &ifmsh->timers_running))
 501                 add_timer(&ifmsh->housekeeping_timer);
 502         if (test_and_clear_bit(TMR_RUNNING_MP, &ifmsh->timers_running))
 503                 add_timer(&ifmsh->mesh_path_timer);
 504         if (test_and_clear_bit(TMR_RUNNING_MPR, &ifmsh->timers_running))
 505                 add_timer(&ifmsh->mesh_path_root_timer);
 506 }
 507 #endif
 508
 509 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
 510 {
 511         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 512         struct ieee80211_local *local = sdata->local;
 513
 514         set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
 515         ieee80211_queue_work(&local->hw, &ifmsh->work);
 516         sdata->vif.bss_conf.beacon_int = MESH_DEFAULT_BEACON_INTERVAL;
 517         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON |
 518                                                 BSS_CHANGED_BEACON_ENABLED |
 519                                                 BSS_CHANGED_BEACON_INT);
 520 }
 521
 522 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
 523 {
 524         del_timer_sync(&sdata->u.mesh.housekeeping_timer);
 525         del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
 526         /*
 527          * If the timer fired while we waited for it, it will have
 528          * requeued the work. Now the work will be running again
 529          * but will not rearm the timer again because it checks
 530          * whether the interface is running, which, at this point,
 531          * it no longer is.
 532          */
 533         cancel_work_sync(&sdata->u.mesh.work);
 534
 535         /*
 536          * When we get here, the interface is marked down.
 537          * Call synchronize_rcu() to wait for the RX path
 538          * should it be using the interface and enqueuing
 539          * frames at this very time on another CPU.
 540          */
 541         rcu_barrier(); /* Wait for RX path and call_rcu()'s */
 542         skb_queue_purge(&sdata->u.mesh.skb_queue);
 543 }
 544
 545 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 546                                         u16 stype,
 547                                         struct ieee80211_mgmt *mgmt,
 548                                         size_t len,
 549                                         struct ieee80211_rx_status *rx_status)
 550 {
 551         struct ieee80211_local *local = sdata->local;
 552         struct ieee802_11_elems elems;
 553         struct ieee80211_channel *channel;
 554         u32 supp_rates = 0;
 555         size_t baselen;
 556         int freq;
 557         enum ieee80211_band band = rx_status->band;
 558
 559         /* ignore ProbeResp to foreign address */
 560         if (stype == IEEE80211_STYPE_PROBE_RESP &&
 561             compare_ether_addr(mgmt->da, sdata->dev->dev_addr))
 562                 return;
 563
 564         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 565         if (baselen > len)
 566                 return;
 567
 568         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 569                                &elems);
 570
 571         if (elems.ds_params && elems.ds_params_len == 1)
 572                 freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
 573         else
 574                 freq = rx_status->freq;
 575
 576         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 577
 578         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 579                 return;
 580
 581         if (elems.mesh_id && elems.mesh_config &&
 582             mesh_matches_local(&elems, sdata)) {
 583                 supp_rates = ieee80211_sta_get_rates(local, &elems, band);
 584
 585                 mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
 586                                       mesh_peer_accepts_plinks(&elems));
 587         }
 588 }
 589
 590 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
 591                                           struct ieee80211_mgmt *mgmt,
 592                                           size_t len,
 593                                           struct ieee80211_rx_status *rx_status)
 594 {
 595         switch (mgmt->u.action.category) {
 596         case MESH_PLINK_CATEGORY:
 597                 mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
 598                 break;
 599         case MESH_PATH_SEL_CATEGORY:
 600                 mesh_rx_path_sel_frame(sdata, mgmt, len);
 601                 break;
 602         }
 603 }
 604
 605 static void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 606                                           struct sk_buff *skb)
 607 {
 608         struct ieee80211_rx_status *rx_status;
 609         struct ieee80211_if_mesh *ifmsh;
 610         struct ieee80211_mgmt *mgmt;
 611         u16 stype;
 612
 613         ifmsh = &sdata->u.mesh;
 614
 615         rx_status = IEEE80211_SKB_RXCB(skb);
 616         mgmt = (struct ieee80211_mgmt *) skb->data;
 617         stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
 618
 619         switch (stype) {
 620         case IEEE80211_STYPE_PROBE_RESP:
 621         case IEEE80211_STYPE_BEACON:
 622                 ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
 623                                             rx_status);
 624                 break;
 625         case IEEE80211_STYPE_ACTION:
 626                 ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
 627                 break;
 628         }
 629
 630         kfree_skb(skb);
 631 }
 632
 633 static void ieee80211_mesh_work(struct work_struct *work)
 634 {
 635         struct ieee80211_sub_if_data *sdata =
 636                 container_of(work, struct ieee80211_sub_if_data, u.mesh.work);
 637         struct ieee80211_local *local = sdata->local;
 638         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 639         struct sk_buff *skb;
 640
 641         if (!netif_running(sdata->dev))
 642                 return;
 643
 644         if (local->scanning)
 645                 return;
 646
 647         while ((skb = skb_dequeue(&ifmsh->skb_queue)))
 648                 ieee80211_mesh_rx_queued_mgmt(sdata, skb);
 649
 650         if (ifmsh->preq_queue_len &&
 651             time_after(jiffies,
 652                        ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
 653                 mesh_path_start_discovery(sdata);
 654
 655         if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
 656                 mesh_mpath_table_grow();
 657
 658         if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
 659                 mesh_mpp_table_grow();
 660
 661         if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
 662                 ieee80211_mesh_housekeeping(sdata, ifmsh);
 663
 664         if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
 665                 ieee80211_mesh_rootpath(sdata);
 666 }
 667
 668 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
 669 {
 670         struct ieee80211_sub_if_data *sdata;
 671
 672         rcu_read_lock();
 673         list_for_each_entry_rcu(sdata, &local->interfaces, list)
 674                 if (ieee80211_vif_is_mesh(&sdata->vif))
 675                         ieee80211_queue_work(&local->hw, &sdata->u.mesh.work);
 676         rcu_read_unlock();
 677 }
 678
 679 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
 680 {
 681         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 682
 683         INIT_WORK(&ifmsh->work, ieee80211_mesh_work);
 684         setup_timer(&ifmsh->housekeeping_timer,
 685                     ieee80211_mesh_housekeeping_timer,
 686                     (unsigned long) sdata);
 687         skb_queue_head_init(&sdata->u.mesh.skb_queue);
 688
 689         ifmsh->mshcfg.dot11MeshRetryTimeout = MESH_RET_T;
 690         ifmsh->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T;
 691         ifmsh->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T;
 692         ifmsh->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR;
 693         ifmsh->mshcfg.dot11MeshTTL = MESH_TTL;
 694         ifmsh->mshcfg.auto_open_plinks = true;
 695         ifmsh->mshcfg.dot11MeshMaxPeerLinks =
 696                 MESH_MAX_ESTAB_PLINKS;
 697         ifmsh->mshcfg.dot11MeshHWMPactivePathTimeout =
 698                 MESH_PATH_TIMEOUT;
 699         ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval =
 700                 MESH_PREQ_MIN_INT;
 701         ifmsh->mshcfg.dot11MeshHWMPnetDiameterTraversalTime =
 702                 MESH_DIAM_TRAVERSAL_TIME;
 703         ifmsh->mshcfg.dot11MeshHWMPmaxPREQretries =
 704                 MESH_MAX_PREQ_RETRIES;
 705         ifmsh->mshcfg.path_refresh_time =
 706                 MESH_PATH_REFRESH_TIME;
 707         ifmsh->mshcfg.min_discovery_timeout =
 708                 MESH_MIN_DISCOVERY_TIMEOUT;
 709         ifmsh->accepting_plinks = true;
 710         ifmsh->preq_id = 0;
 711         ifmsh->sn = 0;
 712         atomic_set(&ifmsh->mpaths, 0);
 713         mesh_rmc_init(sdata);
 714         ifmsh->last_preq = jiffies;
 715         /* Allocate all mesh structures when creating the first mesh interface. */
 716         if (!mesh_allocated)
 717                 ieee80211s_init();
 718         mesh_ids_set_default(ifmsh);
 719         setup_timer(&ifmsh->mesh_path_timer,
 720                     ieee80211_mesh_path_timer,
 721                     (unsigned long) sdata);
 722         setup_timer(&ifmsh->mesh_path_root_timer,
 723                     ieee80211_mesh_path_root_timer,
 724                     (unsigned long) sdata);
 725         INIT_LIST_HEAD(&ifmsh->preq_queue.list);
 726         spin_lock_init(&ifmsh->mesh_preq_queue_lock);
 727 }
 728
 729 ieee80211_rx_result
 730 ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 731 {
 732         struct ieee80211_local *local = sdata->local;
 733         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 734         struct ieee80211_mgmt *mgmt;
 735         u16 fc;
 736
 737         if (skb->len < 24)
 738                 return RX_DROP_MONITOR;
 739
 740         mgmt = (struct ieee80211_mgmt *) skb->data;
 741         fc = le16_to_cpu(mgmt->frame_control);
 742
 743         switch (fc & IEEE80211_FCTL_STYPE) {
 744         case IEEE80211_STYPE_ACTION:
 745                 if (skb->len < IEEE80211_MIN_ACTION_SIZE)
 746                         return RX_DROP_MONITOR;
 747                 /* fall through */
 748         case IEEE80211_STYPE_PROBE_RESP:
 749         case IEEE80211_STYPE_BEACON:
 750                 skb_queue_tail(&ifmsh->skb_queue, skb);
 751                 ieee80211_queue_work(&local->hw, &ifmsh->work);
 752                 return RX_QUEUED;
 753         }
 754
 755         return RX_CONTINUE;
 756 }