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 <linux/slab.h>
  12 #include <asm/unaligned.h>
  13 #include "ieee80211_i.h"
  14 #include "mesh.h"
  15
  16 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
  17 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
  18 #define IEEE80211_MESH_RANN_INTERVAL         (1 * HZ)
  19
  20 #define MESHCONF_CAPAB_ACCEPT_PLINKS 0x01
  21 #define MESHCONF_CAPAB_FORWARDING    0x08
  22
  23 #define TMR_RUNNING_HK  0
  24 #define TMR_RUNNING_MP  1
  25 #define TMR_RUNNING_MPR 2
  26
  27 int mesh_allocated;
  28 static struct kmem_cache *rm_cache;
  29
  30 void ieee80211s_init(void)
  31 {
  32         mesh_pathtbl_init();
  33         mesh_allocated = 1;
  34         rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
  35                                      0, 0, NULL);
  36 }
  37
  38 void ieee80211s_stop(void)
  39 {
  40         mesh_pathtbl_unregister();
  41         kmem_cache_destroy(rm_cache);
  42 }
  43
  44 static void ieee80211_mesh_housekeeping_timer(unsigned long data)
  45 {
  46         struct ieee80211_sub_if_data *sdata = (void *) data;
  47         struct ieee80211_local *local = sdata->local;
  48         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  49
  50         set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
  51
  52         if (local->quiescing) {
  53                 set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
  54                 return;
  55         }
  56
  57         ieee80211_queue_work(&local->hw, &ifmsh->work);
  58 }
  59
  60 /**
  61  * mesh_matches_local - check if the config of a mesh point matches ours
  62  *
  63  * @ie: information elements of a management frame from the mesh peer
  64  * @sdata: local mesh subif
  65  *
  66  * This function checks if the mesh configuration of a mesh point matches the
  67  * local mesh configuration, i.e. if both nodes belong to the same mesh network.
  68  */
  69 bool mesh_matches_local(struct ieee802_11_elems *ie, struct ieee80211_sub_if_data *sdata)
  70 {
  71         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
  72
  73         /*
  74          * As support for each feature is added, check for matching
  75          * - On mesh config capabilities
  76          *   - Power Save Support En
  77          *   - Sync support enabled
  78          *   - Sync support active
  79          *   - Sync support required from peer
  80          *   - MDA enabled
  81          * - Power management control on fc
  82          */
  83         if (ifmsh->mesh_id_len == ie->mesh_id_len &&
  84                 memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
  85                 (ifmsh->mesh_pp_id == ie->mesh_config->meshconf_psel) &&
  86                 (ifmsh->mesh_pm_id == ie->mesh_config->meshconf_pmetric) &&
  87                 (ifmsh->mesh_cc_id == ie->mesh_config->meshconf_congest) &&
  88                 (ifmsh->mesh_sp_id == ie->mesh_config->meshconf_synch) &&
  89                 (ifmsh->mesh_auth_id == ie->mesh_config->meshconf_auth))
  90                 return true;
  91
  92         return false;
  93 }
  94
  95 /**
  96  * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
  97  *
  98  * @ie: information elements of a management frame from the mesh peer
  99  */
 100 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
 101 {
 102         return (ie->mesh_config->meshconf_cap &
 103             MESHCONF_CAPAB_ACCEPT_PLINKS) != 0;
 104 }
 105
 106 /**
 107  * mesh_accept_plinks_update: update accepting_plink in local mesh beacons
 108  *
 109  * @sdata: mesh interface in which mesh beacons are going to be updated
 110  */
 111 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
 112 {
 113         bool free_plinks;
 114
 115         /* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
 116          * the mesh interface might be able to establish plinks with peers that
 117          * are already on the table but are not on PLINK_ESTAB state. However,
 118          * in general the mesh interface is not accepting peer link requests
 119          * from new peers, and that must be reflected in the beacon
 120          */
 121         free_plinks = mesh_plink_availables(sdata);
 122
 123         if (free_plinks != sdata->u.mesh.accepting_plinks)
 124                 ieee80211_mesh_housekeeping_timer((unsigned long) sdata);
 125 }
 126
 127 void mesh_ids_set_default(struct ieee80211_if_mesh *sta)
 128 {
 129         sta->mesh_pp_id = 0;    /* HWMP */
 130         sta->mesh_pm_id = 0;    /* Airtime */
 131         sta->mesh_cc_id = 0;    /* Disabled */
 132         sta->mesh_sp_id = 0;    /* Neighbor Offset */
 133         sta->mesh_auth_id = 0;  /* Disabled */
 134 }
 135
 136 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
 137 {
 138         int i;
 139
 140         sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
 141         if (!sdata->u.mesh.rmc)
 142                 return -ENOMEM;
 143         sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
 144         for (i = 0; i < RMC_BUCKETS; i++)
 145                 INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i].list);
 146         return 0;
 147 }
 148
 149 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
 150 {
 151         struct mesh_rmc *rmc = sdata->u.mesh.rmc;
 152         struct rmc_entry *p, *n;
 153         int i;
 154
 155         if (!sdata->u.mesh.rmc)
 156                 return;
 157
 158         for (i = 0; i < RMC_BUCKETS; i++)
 159                 list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) {
 160                         list_del(&p->list);
 161                         kmem_cache_free(rm_cache, p);
 162                 }
 163
 164         kfree(rmc);
 165         sdata->u.mesh.rmc = NULL;
 166 }
 167
 168 /**
 169  * mesh_rmc_check - Check frame in recent multicast cache and add if absent.
 170  *
 171  * @sa:         source address
 172  * @mesh_hdr:   mesh_header
 173  *
 174  * Returns: 0 if the frame is not in the cache, nonzero otherwise.
 175  *
 176  * Checks using the source address and the mesh sequence number if we have
 177  * received this frame lately. If the frame is not in the cache, it is added to
 178  * it.
 179  */
 180 int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
 181                    struct ieee80211_sub_if_data *sdata)
 182 {
 183         struct mesh_rmc *rmc = sdata->u.mesh.rmc;
 184         u32 seqnum = 0;
 185         int entries = 0;
 186         u8 idx;
 187         struct rmc_entry *p, *n;
 188
 189         /* Don't care about endianness since only match matters */
 190         memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
 191         idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
 192         list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) {
 193                 ++entries;
 194                 if (time_after(jiffies, p->exp_time) ||
 195                                 (entries == RMC_QUEUE_MAX_LEN)) {
 196                         list_del(&p->list);
 197                         kmem_cache_free(rm_cache, p);
 198                         --entries;
 199                 } else if ((seqnum == p->seqnum) &&
 200                            (memcmp(sa, p->sa, ETH_ALEN) == 0))
 201                         return -1;
 202         }
 203
 204         p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
 205         if (!p) {
 206                 printk(KERN_DEBUG "o11s: could not allocate RMC entry\n");
 207                 return 0;
 208         }
 209         p->seqnum = seqnum;
 210         p->exp_time = jiffies + RMC_TIMEOUT;
 211         memcpy(p->sa, sa, ETH_ALEN);
 212         list_add(&p->list, &rmc->bucket[idx].list);
 213         return 0;
 214 }
 215
 216 void mesh_mgmt_ies_add(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
 217 {
 218         struct ieee80211_local *local = sdata->local;
 219         struct ieee80211_supported_band *sband;
 220         u8 *pos;
 221         int len, i, rate;
 222         u8 neighbors;
 223
 224         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 225         len = sband->n_bitrates;
 226         if (len > 8)
 227                 len = 8;
 228         pos = skb_put(skb, len + 2);
 229         *pos++ = WLAN_EID_SUPP_RATES;
 230         *pos++ = len;
 231         for (i = 0; i < len; i++) {
 232                 rate = sband->bitrates[i].bitrate;
 233                 *pos++ = (u8) (rate / 5);
 234         }
 235
 236         if (sband->n_bitrates > len) {
 237                 pos = skb_put(skb, sband->n_bitrates - len + 2);
 238                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
 239                 *pos++ = sband->n_bitrates - len;
 240                 for (i = len; i < sband->n_bitrates; i++) {
 241                         rate = sband->bitrates[i].bitrate;
 242                         *pos++ = (u8) (rate / 5);
 243                 }
 244         }
 245
 246         if (sband->band == IEEE80211_BAND_2GHZ) {
 247                 pos = skb_put(skb, 2 + 1);
 248                 *pos++ = WLAN_EID_DS_PARAMS;
 249                 *pos++ = 1;
 250                 *pos++ = ieee80211_frequency_to_channel(local->hw.conf.channel->center_freq);
 251         }
 252
 253         pos = skb_put(skb, 2 + sdata->u.mesh.mesh_id_len);
 254         *pos++ = WLAN_EID_MESH_ID;
 255         *pos++ = sdata->u.mesh.mesh_id_len;
 256         if (sdata->u.mesh.mesh_id_len)
 257                 memcpy(pos, sdata->u.mesh.mesh_id, sdata->u.mesh.mesh_id_len);
 258
 259         pos = skb_put(skb, 2 + sizeof(struct ieee80211_meshconf_ie));
 260         *pos++ = WLAN_EID_MESH_CONFIG;
 261         *pos++ = sizeof(struct ieee80211_meshconf_ie);
 262
 263         /* Active path selection protocol ID */
 264         *pos++ = sdata->u.mesh.mesh_pp_id;
 265
 266         /* Active path selection metric ID   */
 267         *pos++ = sdata->u.mesh.mesh_pm_id;
 268
 269         /* Congestion control mode identifier */
 270         *pos++ = sdata->u.mesh.mesh_cc_id;
 271
 272         /* Synchronization protocol identifier */
 273         *pos++ = sdata->u.mesh.mesh_sp_id;
 274
 275         /* Authentication Protocol identifier */
 276         *pos++ = sdata->u.mesh.mesh_auth_id;
 277
 278         /* Mesh Formation Info - number of neighbors */
 279         neighbors = atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 280         /* Number of neighbor mesh STAs or 15 whichever is smaller */
 281         neighbors = (neighbors > 15) ? 15 : neighbors;
 282         *pos++ = neighbors << 1;
 283
 284         /* Mesh capability */
 285         sdata->u.mesh.accepting_plinks = mesh_plink_availables(sdata);
 286         *pos = MESHCONF_CAPAB_FORWARDING;
 287         *pos++ |= sdata->u.mesh.accepting_plinks ?
 288             MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
 289         *pos++ = 0x00;
 290
 291         return;
 292 }
 293
 294 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata, struct mesh_table *tbl)
 295 {
 296         /* Use last four bytes of hw addr and interface index as hash index */
 297         return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd)
 298                 & tbl->hash_mask;
 299 }
 300
 301 struct mesh_table *mesh_table_alloc(int size_order)
 302 {
 303         int i;
 304         struct mesh_table *newtbl;
 305
 306         newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL);
 307         if (!newtbl)
 308                 return NULL;
 309
 310         newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
 311                         (1 << size_order), GFP_KERNEL);
 312
 313         if (!newtbl->hash_buckets) {
 314                 kfree(newtbl);
 315                 return NULL;
 316         }
 317
 318         newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
 319                         (1 << size_order), GFP_KERNEL);
 320         if (!newtbl->hashwlock) {
 321                 kfree(newtbl->hash_buckets);
 322                 kfree(newtbl);
 323                 return NULL;
 324         }
 325
 326         newtbl->size_order = size_order;
 327         newtbl->hash_mask = (1 << size_order) - 1;
 328         atomic_set(&newtbl->entries,  0);
 329         get_random_bytes(&newtbl->hash_rnd,
 330                         sizeof(newtbl->hash_rnd));
 331         for (i = 0; i <= newtbl->hash_mask; i++)
 332                 spin_lock_init(&newtbl->hashwlock[i]);
 333
 334         return newtbl;
 335 }
 336
 337
 338 static void ieee80211_mesh_path_timer(unsigned long data)
 339 {
 340         struct ieee80211_sub_if_data *sdata =
 341                 (struct ieee80211_sub_if_data *) data;
 342         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 343         struct ieee80211_local *local = sdata->local;
 344
 345         if (local->quiescing) {
 346                 set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
 347                 return;
 348         }
 349
 350         ieee80211_queue_work(&local->hw, &ifmsh->work);
 351 }
 352
 353 static void ieee80211_mesh_path_root_timer(unsigned long data)
 354 {
 355         struct ieee80211_sub_if_data *sdata =
 356                 (struct ieee80211_sub_if_data *) data;
 357         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 358         struct ieee80211_local *local = sdata->local;
 359
 360         set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
 361
 362         if (local->quiescing) {
 363                 set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
 364                 return;
 365         }
 366
 367         ieee80211_queue_work(&local->hw, &ifmsh->work);
 368 }
 369
 370 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh)
 371 {
 372         if (ifmsh->mshcfg.dot11MeshHWMPRootMode)
 373                 set_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
 374         else {
 375                 clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags);
 376                 /* stop running timer */
 377                 del_timer_sync(&ifmsh->mesh_path_root_timer);
 378         }
 379 }
 380
 381 /**
 382  * ieee80211_fill_mesh_addresses - fill addresses of a locally originated mesh frame
 383  * @hdr:        802.11 frame header
 384  * @fc:         frame control field
 385  * @meshda:     destination address in the mesh
 386  * @meshsa:     source address address in the mesh.  Same as TA, as frame is
 387  *              locally originated.
 388  *
 389  * Return the length of the 802.11 (does not include a mesh control header)
 390  */
 391 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 392                                   const u8 *meshda, const u8 *meshsa)
 393 {
 394         if (is_multicast_ether_addr(meshda)) {
 395                 *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
 396                 /* DA TA SA */
 397                 memcpy(hdr->addr1, meshda, ETH_ALEN);
 398                 memcpy(hdr->addr2, meshsa, ETH_ALEN);
 399                 memcpy(hdr->addr3, meshsa, ETH_ALEN);
 400                 return 24;
 401         } else {
 402                 *fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
 403                                 IEEE80211_FCTL_TODS);
 404                 /* RA TA DA SA */
 405                 memset(hdr->addr1, 0, ETH_ALEN);   /* RA is resolved later */
 406                 memcpy(hdr->addr2, meshsa, ETH_ALEN);
 407                 memcpy(hdr->addr3, meshda, ETH_ALEN);
 408                 memcpy(hdr->addr4, meshsa, ETH_ALEN);
 409                 return 30;
 410         }
 411 }
 412
 413 /**
 414  * ieee80211_new_mesh_header - create a new mesh header
 415  * @meshhdr:    uninitialized mesh header
 416  * @sdata:      mesh interface to be used
 417  * @addr4:      addr4 of the mesh frame (1st in ae header)
 418  *              may be NULL
 419  * @addr5:      addr5 of the mesh frame (1st or 2nd in ae header)
 420  *              may be NULL unless addr6 is present
 421  * @addr6:      addr6 of the mesh frame (2nd or 3rd in ae header)
 422  *              may be NULL unless addr5 is present
 423  *
 424  * Return the header length.
 425  */
 426 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 427                 struct ieee80211_sub_if_data *sdata, char *addr4,
 428                 char *addr5, char *addr6)
 429 {
 430         int aelen = 0;
 431         memset(meshhdr, 0, sizeof(*meshhdr));
 432         meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
 433         put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
 434         sdata->u.mesh.mesh_seqnum++;
 435         if (addr4) {
 436                 meshhdr->flags |= MESH_FLAGS_AE_A4;
 437                 aelen += ETH_ALEN;
 438                 memcpy(meshhdr->eaddr1, addr4, ETH_ALEN);
 439         }
 440         if (addr5 && addr6) {
 441                 meshhdr->flags |= MESH_FLAGS_AE_A5_A6;
 442                 aelen += 2 * ETH_ALEN;
 443                 if (!addr4) {
 444                         memcpy(meshhdr->eaddr1, addr5, ETH_ALEN);
 445                         memcpy(meshhdr->eaddr2, addr6, ETH_ALEN);
 446                 } else {
 447                         memcpy(meshhdr->eaddr2, addr5, ETH_ALEN);
 448                         memcpy(meshhdr->eaddr3, addr6, ETH_ALEN);
 449                 }
 450         }
 451         return 6 + aelen;
 452 }
 453
 454 static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata,
 455                            struct ieee80211_if_mesh *ifmsh)
 456 {
 457         bool free_plinks;
 458
 459 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 460         printk(KERN_DEBUG "%s: running mesh housekeeping\n",
 461                sdata->name);
 462 #endif
 463
 464         ieee80211_sta_expire(sdata, IEEE80211_MESH_PEER_INACTIVITY_LIMIT);
 465         mesh_path_expire(sdata);
 466
 467         free_plinks = mesh_plink_availables(sdata);
 468         if (free_plinks != sdata->u.mesh.accepting_plinks)
 469                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 470
 471         mod_timer(&ifmsh->housekeeping_timer,
 472                   round_jiffies(jiffies + IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
 473 }
 474
 475 static void ieee80211_mesh_rootpath(struct ieee80211_sub_if_data *sdata)
 476 {
 477         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 478
 479         mesh_path_tx_root_frame(sdata);
 480         mod_timer(&ifmsh->mesh_path_root_timer,
 481                   round_jiffies(jiffies + IEEE80211_MESH_RANN_INTERVAL));
 482 }
 483
 484 #ifdef CONFIG_PM
 485 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 486 {
 487         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 488
 489         /* might restart the timer but that doesn't matter */
 490         cancel_work_sync(&ifmsh->work);
 491
 492         /* use atomic bitops in case both timers fire at the same time */
 493
 494         if (del_timer_sync(&ifmsh->housekeeping_timer))
 495                 set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
 496         if (del_timer_sync(&ifmsh->mesh_path_timer))
 497                 set_bit(TMR_RUNNING_MP, &ifmsh->timers_running);
 498         if (del_timer_sync(&ifmsh->mesh_path_root_timer))
 499                 set_bit(TMR_RUNNING_MPR, &ifmsh->timers_running);
 500 }
 501
 502 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 503 {
 504         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 505
 506         if (test_and_clear_bit(TMR_RUNNING_HK, &ifmsh->timers_running))
 507                 add_timer(&ifmsh->housekeeping_timer);
 508         if (test_and_clear_bit(TMR_RUNNING_MP, &ifmsh->timers_running))
 509                 add_timer(&ifmsh->mesh_path_timer);
 510         if (test_and_clear_bit(TMR_RUNNING_MPR, &ifmsh->timers_running))
 511                 add_timer(&ifmsh->mesh_path_root_timer);
 512         ieee80211_mesh_root_setup(ifmsh);
 513 }
 514 #endif
 515
 516 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
 517 {
 518         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 519         struct ieee80211_local *local = sdata->local;
 520
 521         set_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags);
 522         ieee80211_mesh_root_setup(ifmsh);
 523         ieee80211_queue_work(&local->hw, &ifmsh->work);
 524         sdata->vif.bss_conf.beacon_int = MESH_DEFAULT_BEACON_INTERVAL;
 525         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON |
 526                                                 BSS_CHANGED_BEACON_ENABLED |
 527                                                 BSS_CHANGED_BEACON_INT);
 528 }
 529
 530 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
 531 {
 532         del_timer_sync(&sdata->u.mesh.housekeeping_timer);
 533         del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);
 534         /*
 535          * If the timer fired while we waited for it, it will have
 536          * requeued the work. Now the work will be running again
 537          * but will not rearm the timer again because it checks
 538          * whether the interface is running, which, at this point,
 539          * it no longer is.
 540          */
 541         cancel_work_sync(&sdata->u.mesh.work);
 542
 543         /*
 544          * When we get here, the interface is marked down.
 545          * Call synchronize_rcu() to wait for the RX path
 546          * should it be using the interface and enqueuing
 547          * frames at this very time on another CPU.
 548          */
 549         rcu_barrier(); /* Wait for RX path and call_rcu()'s */
 550         skb_queue_purge(&sdata->u.mesh.skb_queue);
 551 }
 552
 553 static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
 554                                         u16 stype,
 555                                         struct ieee80211_mgmt *mgmt,
 556                                         size_t len,
 557                                         struct ieee80211_rx_status *rx_status)
 558 {
 559         struct ieee80211_local *local = sdata->local;
 560         struct ieee802_11_elems elems;
 561         struct ieee80211_channel *channel;
 562         u32 supp_rates = 0;
 563         size_t baselen;
 564         int freq;
 565         enum ieee80211_band band = rx_status->band;
 566
 567         /* ignore ProbeResp to foreign address */
 568         if (stype == IEEE80211_STYPE_PROBE_RESP &&
 569             compare_ether_addr(mgmt->da, sdata->vif.addr))
 570                 return;
 571
 572         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
 573         if (baselen > len)
 574                 return;
 575
 576         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
 577                                &elems);
 578
 579         if (elems.ds_params && elems.ds_params_len == 1)
 580                 freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
 581         else
 582                 freq = rx_status->freq;
 583
 584         channel = ieee80211_get_channel(local->hw.wiphy, freq);
 585
 586         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 587                 return;
 588
 589         if (elems.mesh_id && elems.mesh_config &&
 590             mesh_matches_local(&elems, sdata)) {
 591                 supp_rates = ieee80211_sta_get_rates(local, &elems, band);
 592
 593                 mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
 594                                       mesh_peer_accepts_plinks(&elems));
 595         }
 596 }
 597
 598 static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
 599                                           struct ieee80211_mgmt *mgmt,
 600                                           size_t len,
 601                                           struct ieee80211_rx_status *rx_status)
 602 {
 603         switch (mgmt->u.action.category) {
 604         case MESH_PLINK_CATEGORY:
 605                 mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
 606                 break;
 607         case MESH_PATH_SEL_CATEGORY:
 608                 mesh_rx_path_sel_frame(sdata, mgmt, len);
 609                 break;
 610         }
 611 }
 612
 613 static void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 614                                           struct sk_buff *skb)
 615 {
 616         struct ieee80211_rx_status *rx_status;
 617         struct ieee80211_if_mesh *ifmsh;
 618         struct ieee80211_mgmt *mgmt;
 619         u16 stype;
 620
 621         ifmsh = &sdata->u.mesh;
 622
 623         rx_status = IEEE80211_SKB_RXCB(skb);
 624         mgmt = (struct ieee80211_mgmt *) skb->data;
 625         stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
 626
 627         switch (stype) {
 628         case IEEE80211_STYPE_PROBE_RESP:
 629         case IEEE80211_STYPE_BEACON:
 630                 ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
 631                                             rx_status);
 632                 break;
 633         case IEEE80211_STYPE_ACTION:
 634                 ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
 635                 break;
 636         }
 637
 638         kfree_skb(skb);
 639 }
 640
 641 static void ieee80211_mesh_work(struct work_struct *work)
 642 {
 643         struct ieee80211_sub_if_data *sdata =
 644                 container_of(work, struct ieee80211_sub_if_data, u.mesh.work);
 645         struct ieee80211_local *local = sdata->local;
 646         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 647         struct sk_buff *skb;
 648
 649         if (!ieee80211_sdata_running(sdata))
 650                 return;
 651
 652         if (local->scanning)
 653                 return;
 654
 655         while ((skb = skb_dequeue(&ifmsh->skb_queue)))
 656                 ieee80211_mesh_rx_queued_mgmt(sdata, skb);
 657
 658         if (ifmsh->preq_queue_len &&
 659             time_after(jiffies,
 660                        ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
 661                 mesh_path_start_discovery(sdata);
 662
 663         if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
 664                 mesh_mpath_table_grow();
 665
 666         if (test_and_clear_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags))
 667                 mesh_mpp_table_grow();
 668
 669         if (test_and_clear_bit(MESH_WORK_HOUSEKEEPING, &ifmsh->wrkq_flags))
 670                 ieee80211_mesh_housekeeping(sdata, ifmsh);
 671
 672         if (test_and_clear_bit(MESH_WORK_ROOT, &ifmsh->wrkq_flags))
 673                 ieee80211_mesh_rootpath(sdata);
 674 }
 675
 676 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
 677 {
 678         struct ieee80211_sub_if_data *sdata;
 679
 680         rcu_read_lock();
 681         list_for_each_entry_rcu(sdata, &local->interfaces, list)
 682                 if (ieee80211_vif_is_mesh(&sdata->vif))
 683                         ieee80211_queue_work(&local->hw, &sdata->u.mesh.work);
 684         rcu_read_unlock();
 685 }
 686
 687 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
 688 {
 689         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 690
 691         INIT_WORK(&ifmsh->work, ieee80211_mesh_work);
 692         setup_timer(&ifmsh->housekeeping_timer,
 693                     ieee80211_mesh_housekeeping_timer,
 694                     (unsigned long) sdata);
 695         skb_queue_head_init(&sdata->u.mesh.skb_queue);
 696
 697         ifmsh->mshcfg.dot11MeshRetryTimeout = MESH_RET_T;
 698         ifmsh->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T;
 699         ifmsh->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T;
 700         ifmsh->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR;
 701         ifmsh->mshcfg.dot11MeshTTL = MESH_TTL;
 702         ifmsh->mshcfg.auto_open_plinks = true;
 703         ifmsh->mshcfg.dot11MeshMaxPeerLinks =
 704                 MESH_MAX_ESTAB_PLINKS;
 705         ifmsh->mshcfg.dot11MeshHWMPactivePathTimeout =
 706                 MESH_PATH_TIMEOUT;
 707         ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval =
 708                 MESH_PREQ_MIN_INT;
 709         ifmsh->mshcfg.dot11MeshHWMPnetDiameterTraversalTime =
 710                 MESH_DIAM_TRAVERSAL_TIME;
 711         ifmsh->mshcfg.dot11MeshHWMPmaxPREQretries =
 712                 MESH_MAX_PREQ_RETRIES;
 713         ifmsh->mshcfg.path_refresh_time =
 714                 MESH_PATH_REFRESH_TIME;
 715         ifmsh->mshcfg.min_discovery_timeout =
 716                 MESH_MIN_DISCOVERY_TIMEOUT;
 717         ifmsh->accepting_plinks = true;
 718         ifmsh->preq_id = 0;
 719         ifmsh->sn = 0;
 720         atomic_set(&ifmsh->mpaths, 0);
 721         mesh_rmc_init(sdata);
 722         ifmsh->last_preq = jiffies;
 723         /* Allocate all mesh structures when creating the first mesh interface. */
 724         if (!mesh_allocated)
 725                 ieee80211s_init();
 726         mesh_ids_set_default(ifmsh);
 727         setup_timer(&ifmsh->mesh_path_timer,
 728                     ieee80211_mesh_path_timer,
 729                     (unsigned long) sdata);
 730         setup_timer(&ifmsh->mesh_path_root_timer,
 731                     ieee80211_mesh_path_root_timer,
 732                     (unsigned long) sdata);
 733         INIT_LIST_HEAD(&ifmsh->preq_queue.list);
 734         spin_lock_init(&ifmsh->mesh_preq_queue_lock);
 735 }
 736
 737 ieee80211_rx_result
 738 ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
 739 {
 740         struct ieee80211_local *local = sdata->local;
 741         struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
 742         struct ieee80211_mgmt *mgmt;
 743         u16 fc;
 744
 745         if (skb->len < 24)
 746                 return RX_DROP_MONITOR;
 747
 748         mgmt = (struct ieee80211_mgmt *) skb->data;
 749         fc = le16_to_cpu(mgmt->frame_control);
 750
 751         switch (fc & IEEE80211_FCTL_STYPE) {
 752         case IEEE80211_STYPE_ACTION:
 753         case IEEE80211_STYPE_PROBE_RESP:
 754         case IEEE80211_STYPE_BEACON:
 755                 skb_queue_tail(&ifmsh->skb_queue, skb);
 756                 ieee80211_queue_work(&local->hw, &ifmsh->work);
 757                 return RX_QUEUED;
 758         }
 759
 760         return RX_CONTINUE;
 761 }