net/mac80211/mesh_plink.c

   1 /*
   2  * Copyright (c) 2008, 2009 open80211s Ltd.
   3  * Author:     Luis Carlos Cobo <luisca@cozybit.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9 #include <linux/gfp.h>
  10 #include <linux/kernel.h>
  11 #include <linux/random.h>
  12 #include "ieee80211_i.h"
  13 #include "rate.h"
  14 #include "mesh.h"
  15
  16 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
  17 #define mpl_dbg(fmt, args...)   printk(KERN_DEBUG fmt, ##args)
  18 #else
  19 #define mpl_dbg(fmt, args...)   do { (void)(0); } while (0)
  20 #endif
  21
  22 #define PLINK_GET_LLID(p) (p + 4)
  23 #define PLINK_GET_PLID(p) (p + 6)
  24
  25 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
  26                                 jiffies + HZ * t / 1000))
  27
  28 /* Peer link cancel reasons, all subject to ANA approval */
  29 #define MESH_LINK_CANCELLED                     2
  30 #define MESH_MAX_NEIGHBORS                      3
  31 #define MESH_CAPABILITY_POLICY_VIOLATION        4
  32 #define MESH_CLOSE_RCVD                         5
  33 #define MESH_MAX_RETRIES                        6
  34 #define MESH_CONFIRM_TIMEOUT                    7
  35 #define MESH_SECURITY_ROLE_NEGOTIATION_DIFFERS  8
  36 #define MESH_SECURITY_AUTHENTICATION_IMPOSSIBLE 9
  37 #define MESH_SECURITY_FAILED_VERIFICATION       10
  38
  39 #define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
  40 #define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
  41 #define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
  42 #define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
  43 #define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
  44
  45 enum plink_frame_type {
  46         PLINK_OPEN = 0,
  47         PLINK_CONFIRM,
  48         PLINK_CLOSE
  49 };
  50
  51 enum plink_event {
  52         PLINK_UNDEFINED,
  53         OPN_ACPT,
  54         OPN_RJCT,
  55         OPN_IGNR,
  56         CNF_ACPT,
  57         CNF_RJCT,
  58         CNF_IGNR,
  59         CLS_ACPT,
  60         CLS_IGNR
  61 };
  62
  63 static inline
  64 void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
  65 {
  66         atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
  67         mesh_accept_plinks_update(sdata);
  68 }
  69
  70 static inline
  71 void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
  72 {
  73         atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
  74         mesh_accept_plinks_update(sdata);
  75 }
  76
  77 /**
  78  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  79  *
  80  * @sta: mesh peer link to restart
  81  *
  82  * Locking: this function must be called holding sta->lock
  83  */
  84 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  85 {
  86         sta->plink_state = PLINK_LISTEN;
  87         sta->llid = sta->plid = sta->reason = 0;
  88         sta->plink_retries = 0;
  89 }
  90
  91 /*
  92  * NOTE: This is just an alias for sta_info_alloc(), see notes
  93  *       on it in the lifecycle management section!
  94  */
  95 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
  96                                          u8 *hw_addr, u32 rates)
  97 {
  98         struct ieee80211_local *local = sdata->local;
  99         struct sta_info *sta;
 100
 101         if (local->num_sta >= MESH_MAX_PLINKS)
 102                 return NULL;
 103
 104         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 105         if (!sta)
 106                 return NULL;
 107
 108         sta->flags = WLAN_STA_AUTHORIZED | WLAN_STA_AUTH;
 109         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 110         rate_control_rate_init(sta);
 111
 112         return sta;
 113 }
 114
 115 /**
 116  * __mesh_plink_deactivate - deactivate mesh peer link
 117  *
 118  * @sta: mesh peer link to deactivate
 119  *
 120  * All mesh paths with this peer as next hop will be flushed
 121  *
 122  * Locking: the caller must hold sta->lock
 123  */
 124 static bool __mesh_plink_deactivate(struct sta_info *sta)
 125 {
 126         struct ieee80211_sub_if_data *sdata = sta->sdata;
 127         bool deactivated = false;
 128
 129         if (sta->plink_state == PLINK_ESTAB) {
 130                 mesh_plink_dec_estab_count(sdata);
 131                 deactivated = true;
 132         }
 133         sta->plink_state = PLINK_BLOCKED;
 134         mesh_path_flush_by_nexthop(sta);
 135
 136         return deactivated;
 137 }
 138
 139 /**
 140  * mesh_plink_deactivate - deactivate mesh peer link
 141  *
 142  * @sta: mesh peer link to deactivate
 143  *
 144  * All mesh paths with this peer as next hop will be flushed
 145  */
 146 void mesh_plink_deactivate(struct sta_info *sta)
 147 {
 148         struct ieee80211_sub_if_data *sdata = sta->sdata;
 149         bool deactivated;
 150
 151         spin_lock_bh(&sta->lock);
 152         deactivated = __mesh_plink_deactivate(sta);
 153         spin_unlock_bh(&sta->lock);
 154
 155         if (deactivated)
 156                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 157 }
 158
 159 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 160                 enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,
 161                 __le16 reason) {
 162         struct ieee80211_local *local = sdata->local;
 163         struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400 +
 164                         sdata->u.mesh.ie_len);
 165         struct ieee80211_mgmt *mgmt;
 166         bool include_plid = false;
 167         static const u8 meshpeeringproto[] = { 0x00, 0x0F, 0xAC, 0x2A };
 168         u8 *pos;
 169         int ie_len;
 170
 171         if (!skb)
 172                 return -1;
 173         skb_reserve(skb, local->hw.extra_tx_headroom);
 174         /* 25 is the size of the common mgmt part (24) plus the size of the
 175          * common action part (1)
 176          */
 177         mgmt = (struct ieee80211_mgmt *)
 178                 skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));
 179         memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));
 180         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 181                                           IEEE80211_STYPE_ACTION);
 182         memcpy(mgmt->da, da, ETH_ALEN);
 183         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 184         /* BSSID is left zeroed, wildcard value */
 185         mgmt->u.action.category = WLAN_CATEGORY_MESH_PLINK;
 186         mgmt->u.action.u.plink_action.action_code = action;
 187
 188         if (action == PLINK_CLOSE)
 189                 mgmt->u.action.u.plink_action.aux = reason;
 190         else {
 191                 mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);
 192                 if (action == PLINK_CONFIRM) {
 193                         pos = skb_put(skb, 4);
 194                         /* two-byte status code followed by two-byte AID */
 195                         memset(pos, 0, 2);
 196                         memcpy(pos + 2, &plid, 2);
 197                 }
 198                 mesh_mgmt_ies_add(skb, sdata);
 199         }
 200
 201         /* Add Peer Link Management element */
 202         switch (action) {
 203         case PLINK_OPEN:
 204                 ie_len = 6;
 205                 break;
 206         case PLINK_CONFIRM:
 207                 ie_len = 8;
 208                 include_plid = true;
 209                 break;
 210         case PLINK_CLOSE:
 211         default:
 212                 if (!plid)
 213                         ie_len = 8;
 214                 else {
 215                         ie_len = 10;
 216                         include_plid = true;
 217                 }
 218                 break;
 219         }
 220
 221         pos = skb_put(skb, 2 + ie_len);
 222         *pos++ = WLAN_EID_PEER_LINK;
 223         *pos++ = ie_len;
 224         memcpy(pos, meshpeeringproto, sizeof(meshpeeringproto));
 225         pos += 4;
 226         memcpy(pos, &llid, 2);
 227         if (include_plid) {
 228                 pos += 2;
 229                 memcpy(pos, &plid, 2);
 230         }
 231         if (action == PLINK_CLOSE) {
 232                 pos += 2;
 233                 memcpy(pos, &reason, 2);
 234         }
 235
 236         ieee80211_tx_skb(sdata, skb);
 237         return 0;
 238 }
 239
 240 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 241                 struct ieee80211_sub_if_data *sdata,
 242                 struct ieee802_11_elems *elems)
 243 {
 244         struct ieee80211_local *local = sdata->local;
 245         struct sta_info *sta;
 246
 247         rcu_read_lock();
 248
 249         sta = sta_info_get(sdata, hw_addr);
 250         if (!sta) {
 251                 rcu_read_unlock();
 252                 /* Userspace handles peer allocation when security is enabled
 253                  * */
 254                 if (sdata->u.mesh.is_secure)
 255                         cfg80211_notify_new_peer_candidate(sdata->dev, hw_addr,
 256                                         elems->ie_start, elems->total_len,
 257                                         GFP_KERNEL);
 258                 else
 259                         sta = mesh_plink_alloc(sdata, hw_addr, rates);
 260                 if (!sta)
 261                         return;
 262                 if (sta_info_insert_rcu(sta)) {
 263                         rcu_read_unlock();
 264                         return;
 265                 }
 266         }
 267
 268         sta->last_rx = jiffies;
 269         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 270         if (mesh_peer_accepts_plinks(elems) &&
 271                         sta->plink_state == PLINK_LISTEN &&
 272                         sdata->u.mesh.accepting_plinks &&
 273                         sdata->u.mesh.mshcfg.auto_open_plinks)
 274                 mesh_plink_open(sta);
 275
 276         rcu_read_unlock();
 277 }
 278
 279 static void mesh_plink_timer(unsigned long data)
 280 {
 281         struct sta_info *sta;
 282         __le16 llid, plid, reason;
 283         struct ieee80211_sub_if_data *sdata;
 284
 285         /*
 286          * This STA is valid because sta_info_destroy() will
 287          * del_timer_sync() this timer after having made sure
 288          * it cannot be readded (by deleting the plink.)
 289          */
 290         sta = (struct sta_info *) data;
 291
 292         if (sta->sdata->local->quiescing) {
 293                 sta->plink_timer_was_running = true;
 294                 return;
 295         }
 296
 297         spin_lock_bh(&sta->lock);
 298         if (sta->ignore_plink_timer) {
 299                 sta->ignore_plink_timer = false;
 300                 spin_unlock_bh(&sta->lock);
 301                 return;
 302         }
 303         mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
 304                 sta->sta.addr, sta->plink_state);
 305         reason = 0;
 306         llid = sta->llid;
 307         plid = sta->plid;
 308         sdata = sta->sdata;
 309
 310         switch (sta->plink_state) {
 311         case PLINK_OPN_RCVD:
 312         case PLINK_OPN_SNT:
 313                 /* retry timer */
 314                 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
 315                         u32 rand;
 316                         mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
 317                                 sta->sta.addr, sta->plink_retries,
 318                                 sta->plink_timeout);
 319                         get_random_bytes(&rand, sizeof(u32));
 320                         sta->plink_timeout = sta->plink_timeout +
 321                                              rand % sta->plink_timeout;
 322                         ++sta->plink_retries;
 323                         mod_plink_timer(sta, sta->plink_timeout);
 324                         spin_unlock_bh(&sta->lock);
 325                         mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
 326                                             0, 0);
 327                         break;
 328                 }
 329                 reason = cpu_to_le16(MESH_MAX_RETRIES);
 330                 /* fall through on else */
 331         case PLINK_CNF_RCVD:
 332                 /* confirm timer */
 333                 if (!reason)
 334                         reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
 335                 sta->plink_state = PLINK_HOLDING;
 336                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 337                 spin_unlock_bh(&sta->lock);
 338                 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid, plid,
 339                                     reason);
 340                 break;
 341         case PLINK_HOLDING:
 342                 /* holding timer */
 343                 del_timer(&sta->plink_timer);
 344                 mesh_plink_fsm_restart(sta);
 345                 spin_unlock_bh(&sta->lock);
 346                 break;
 347         default:
 348                 spin_unlock_bh(&sta->lock);
 349                 break;
 350         }
 351 }
 352
 353 #ifdef CONFIG_PM
 354 void mesh_plink_quiesce(struct sta_info *sta)
 355 {
 356         if (del_timer_sync(&sta->plink_timer))
 357                 sta->plink_timer_was_running = true;
 358 }
 359
 360 void mesh_plink_restart(struct sta_info *sta)
 361 {
 362         if (sta->plink_timer_was_running) {
 363                 add_timer(&sta->plink_timer);
 364                 sta->plink_timer_was_running = false;
 365         }
 366 }
 367 #endif
 368
 369 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 370 {
 371         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 372         sta->plink_timer.data = (unsigned long) sta;
 373         sta->plink_timer.function = mesh_plink_timer;
 374         sta->plink_timeout = timeout;
 375         add_timer(&sta->plink_timer);
 376 }
 377
 378 int mesh_plink_open(struct sta_info *sta)
 379 {
 380         __le16 llid;
 381         struct ieee80211_sub_if_data *sdata = sta->sdata;
 382
 383         if (!test_sta_flags(sta, WLAN_STA_AUTH))
 384                 return -EPERM;
 385
 386         spin_lock_bh(&sta->lock);
 387         get_random_bytes(&llid, 2);
 388         sta->llid = llid;
 389         if (sta->plink_state != PLINK_LISTEN) {
 390                 spin_unlock_bh(&sta->lock);
 391                 return -EBUSY;
 392         }
 393         sta->plink_state = PLINK_OPN_SNT;
 394         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 395         spin_unlock_bh(&sta->lock);
 396         mpl_dbg("Mesh plink: starting establishment with %pM\n",
 397                 sta->sta.addr);
 398
 399         return mesh_plink_frame_tx(sdata, PLINK_OPEN,
 400                                    sta->sta.addr, llid, 0, 0);
 401 }
 402
 403 void mesh_plink_block(struct sta_info *sta)
 404 {
 405         struct ieee80211_sub_if_data *sdata = sta->sdata;
 406         bool deactivated;
 407
 408         spin_lock_bh(&sta->lock);
 409         deactivated = __mesh_plink_deactivate(sta);
 410         sta->plink_state = PLINK_BLOCKED;
 411         spin_unlock_bh(&sta->lock);
 412
 413         if (deactivated)
 414                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 415 }
 416
 417
 418 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 419                          size_t len, struct ieee80211_rx_status *rx_status)
 420 {
 421         struct ieee80211_local *local = sdata->local;
 422         struct ieee802_11_elems elems;
 423         struct sta_info *sta;
 424         enum plink_event event;
 425         enum plink_frame_type ftype;
 426         size_t baselen;
 427         bool deactivated, matches_local = true;
 428         u8 ie_len;
 429         u8 *baseaddr;
 430         __le16 plid, llid, reason;
 431 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
 432         static const char *mplstates[] = {
 433                 [PLINK_LISTEN] = "LISTEN",
 434                 [PLINK_OPN_SNT] = "OPN-SNT",
 435                 [PLINK_OPN_RCVD] = "OPN-RCVD",
 436                 [PLINK_CNF_RCVD] = "CNF_RCVD",
 437                 [PLINK_ESTAB] = "ESTAB",
 438                 [PLINK_HOLDING] = "HOLDING",
 439                 [PLINK_BLOCKED] = "BLOCKED"
 440         };
 441 #endif
 442
 443         /* need action_code, aux */
 444         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 445                 return;
 446
 447         if (is_multicast_ether_addr(mgmt->da)) {
 448                 mpl_dbg("Mesh plink: ignore frame from multicast address");
 449                 return;
 450         }
 451
 452         baseaddr = mgmt->u.action.u.plink_action.variable;
 453         baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;
 454         if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {
 455                 baseaddr += 4;
 456                 baselen += 4;
 457         }
 458         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 459         if (!elems.peer_link) {
 460                 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
 461                 return;
 462         }
 463         if (elems.rsn_len && !sdata->u.mesh.is_secure) {
 464                 mpl_dbg("Mesh plink: can't establish link with secure peer\n");
 465                 return;
 466         }
 467
 468         ftype = mgmt->u.action.u.plink_action.action_code;
 469         ie_len = elems.peer_link_len;
 470         if ((ftype == PLINK_OPEN && ie_len != 6) ||
 471             (ftype == PLINK_CONFIRM && ie_len != 8) ||
 472             (ftype == PLINK_CLOSE && ie_len != 8 && ie_len != 10)) {
 473                 mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
 474                     ftype, ie_len);
 475                 return;
 476         }
 477
 478         if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
 479                 mpl_dbg("Mesh plink: missing necessary ie\n");
 480                 return;
 481         }
 482         /* Note the lines below are correct, the llid in the frame is the plid
 483          * from the point of view of this host.
 484          */
 485         memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
 486         if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 10))
 487                 memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
 488
 489         rcu_read_lock();
 490
 491         sta = sta_info_get(sdata, mgmt->sa);
 492         if (!sta && ftype != PLINK_OPEN) {
 493                 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
 494                 rcu_read_unlock();
 495                 return;
 496         }
 497
 498         if (sta && !test_sta_flags(sta, WLAN_STA_AUTH)) {
 499                 mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
 500                 rcu_read_unlock();
 501                 return;
 502         }
 503
 504         if (sta && sta->plink_state == PLINK_BLOCKED) {
 505                 rcu_read_unlock();
 506                 return;
 507         }
 508
 509         /* Now we will figure out the appropriate event... */
 510         event = PLINK_UNDEFINED;
 511         if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) {
 512                 matches_local = false;
 513                 switch (ftype) {
 514                 case PLINK_OPEN:
 515                         event = OPN_RJCT;
 516                         break;
 517                 case PLINK_CONFIRM:
 518                         event = CNF_RJCT;
 519                         break;
 520                 case PLINK_CLOSE:
 521                         /* avoid warning */
 522                         break;
 523                 }
 524         }
 525
 526         if (!sta && !matches_local) {
 527                 rcu_read_unlock();
 528                 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 529                 llid = 0;
 530                 mesh_plink_frame_tx(sdata, PLINK_CLOSE, mgmt->sa, llid,
 531                                     plid, reason);
 532                 return;
 533         } else if (!sta) {
 534                 /* ftype == PLINK_OPEN */
 535                 u32 rates;
 536
 537                 rcu_read_unlock();
 538
 539                 if (!mesh_plink_free_count(sdata)) {
 540                         mpl_dbg("Mesh plink error: no more free plinks\n");
 541                         return;
 542                 }
 543
 544                 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
 545                 sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
 546                 if (!sta) {
 547                         mpl_dbg("Mesh plink error: plink table full\n");
 548                         return;
 549                 }
 550                 if (sta_info_insert_rcu(sta)) {
 551                         rcu_read_unlock();
 552                         return;
 553                 }
 554                 event = OPN_ACPT;
 555                 spin_lock_bh(&sta->lock);
 556         } else if (matches_local) {
 557                 spin_lock_bh(&sta->lock);
 558                 switch (ftype) {
 559                 case PLINK_OPEN:
 560                         if (!mesh_plink_free_count(sdata) ||
 561                             (sta->plid && sta->plid != plid))
 562                                 event = OPN_IGNR;
 563                         else
 564                                 event = OPN_ACPT;
 565                         break;
 566                 case PLINK_CONFIRM:
 567                         if (!mesh_plink_free_count(sdata) ||
 568                             (sta->llid != llid || sta->plid != plid))
 569                                 event = CNF_IGNR;
 570                         else
 571                                 event = CNF_ACPT;
 572                         break;
 573                 case PLINK_CLOSE:
 574                         if (sta->plink_state == PLINK_ESTAB)
 575                                 /* Do not check for llid or plid. This does not
 576                                  * follow the standard but since multiple plinks
 577                                  * per sta are not supported, it is necessary in
 578                                  * order to avoid a livelock when MP A sees an
 579                                  * establish peer link to MP B but MP B does not
 580                                  * see it. This can be caused by a timeout in
 581                                  * B's peer link establishment or B beign
 582                                  * restarted.
 583                                  */
 584                                 event = CLS_ACPT;
 585                         else if (sta->plid != plid)
 586                                 event = CLS_IGNR;
 587                         else if (ie_len == 7 && sta->llid != llid)
 588                                 event = CLS_IGNR;
 589                         else
 590                                 event = CLS_ACPT;
 591                         break;
 592                 default:
 593                         mpl_dbg("Mesh plink: unknown frame subtype\n");
 594                         spin_unlock_bh(&sta->lock);
 595                         rcu_read_unlock();
 596                         return;
 597                 }
 598         } else {
 599                 spin_lock_bh(&sta->lock);
 600         }
 601
 602         mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 603                 mgmt->sa, mplstates[sta->plink_state],
 604                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 605                 event);
 606         reason = 0;
 607         switch (sta->plink_state) {
 608                 /* spin_unlock as soon as state is updated at each case */
 609         case PLINK_LISTEN:
 610                 switch (event) {
 611                 case CLS_ACPT:
 612                         mesh_plink_fsm_restart(sta);
 613                         spin_unlock_bh(&sta->lock);
 614                         break;
 615                 case OPN_ACPT:
 616                         sta->plink_state = PLINK_OPN_RCVD;
 617                         sta->plid = plid;
 618                         get_random_bytes(&llid, 2);
 619                         sta->llid = llid;
 620                         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 621                         spin_unlock_bh(&sta->lock);
 622                         mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
 623                                             0, 0);
 624                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr,
 625                                             llid, plid, 0);
 626                         break;
 627                 default:
 628                         spin_unlock_bh(&sta->lock);
 629                         break;
 630                 }
 631                 break;
 632
 633         case PLINK_OPN_SNT:
 634                 switch (event) {
 635                 case OPN_RJCT:
 636                 case CNF_RJCT:
 637                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 638                 case CLS_ACPT:
 639                         if (!reason)
 640                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 641                         sta->reason = reason;
 642                         sta->plink_state = PLINK_HOLDING;
 643                         if (!mod_plink_timer(sta,
 644                                              dot11MeshHoldingTimeout(sdata)))
 645                                 sta->ignore_plink_timer = true;
 646
 647                         llid = sta->llid;
 648                         spin_unlock_bh(&sta->lock);
 649                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 650                                             plid, reason);
 651                         break;
 652                 case OPN_ACPT:
 653                         /* retry timer is left untouched */
 654                         sta->plink_state = PLINK_OPN_RCVD;
 655                         sta->plid = plid;
 656                         llid = sta->llid;
 657                         spin_unlock_bh(&sta->lock);
 658                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 659                                             plid, 0);
 660                         break;
 661                 case CNF_ACPT:
 662                         sta->plink_state = PLINK_CNF_RCVD;
 663                         if (!mod_plink_timer(sta,
 664                                              dot11MeshConfirmTimeout(sdata)))
 665                                 sta->ignore_plink_timer = true;
 666
 667                         spin_unlock_bh(&sta->lock);
 668                         break;
 669                 default:
 670                         spin_unlock_bh(&sta->lock);
 671                         break;
 672                 }
 673                 break;
 674
 675         case PLINK_OPN_RCVD:
 676                 switch (event) {
 677                 case OPN_RJCT:
 678                 case CNF_RJCT:
 679                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 680                 case CLS_ACPT:
 681                         if (!reason)
 682                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 683                         sta->reason = reason;
 684                         sta->plink_state = PLINK_HOLDING;
 685                         if (!mod_plink_timer(sta,
 686                                              dot11MeshHoldingTimeout(sdata)))
 687                                 sta->ignore_plink_timer = true;
 688
 689                         llid = sta->llid;
 690                         spin_unlock_bh(&sta->lock);
 691                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 692                                             plid, reason);
 693                         break;
 694                 case OPN_ACPT:
 695                         llid = sta->llid;
 696                         spin_unlock_bh(&sta->lock);
 697                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 698                                             plid, 0);
 699                         break;
 700                 case CNF_ACPT:
 701                         del_timer(&sta->plink_timer);
 702                         sta->plink_state = PLINK_ESTAB;
 703                         spin_unlock_bh(&sta->lock);
 704                         mesh_plink_inc_estab_count(sdata);
 705                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 706                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 707                                 sta->sta.addr);
 708                         break;
 709                 default:
 710                         spin_unlock_bh(&sta->lock);
 711                         break;
 712                 }
 713                 break;
 714
 715         case PLINK_CNF_RCVD:
 716                 switch (event) {
 717                 case OPN_RJCT:
 718                 case CNF_RJCT:
 719                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 720                 case CLS_ACPT:
 721                         if (!reason)
 722                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 723                         sta->reason = reason;
 724                         sta->plink_state = PLINK_HOLDING;
 725                         if (!mod_plink_timer(sta,
 726                                              dot11MeshHoldingTimeout(sdata)))
 727                                 sta->ignore_plink_timer = true;
 728
 729                         llid = sta->llid;
 730                         spin_unlock_bh(&sta->lock);
 731                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 732                                             plid, reason);
 733                         break;
 734                 case OPN_ACPT:
 735                         del_timer(&sta->plink_timer);
 736                         sta->plink_state = PLINK_ESTAB;
 737                         spin_unlock_bh(&sta->lock);
 738                         mesh_plink_inc_estab_count(sdata);
 739                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 740                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 741                                 sta->sta.addr);
 742                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 743                                             plid, 0);
 744                         break;
 745                 default:
 746                         spin_unlock_bh(&sta->lock);
 747                         break;
 748                 }
 749                 break;
 750
 751         case PLINK_ESTAB:
 752                 switch (event) {
 753                 case CLS_ACPT:
 754                         reason = cpu_to_le16(MESH_CLOSE_RCVD);
 755                         sta->reason = reason;
 756                         deactivated = __mesh_plink_deactivate(sta);
 757                         sta->plink_state = PLINK_HOLDING;
 758                         llid = sta->llid;
 759                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 760                         spin_unlock_bh(&sta->lock);
 761                         if (deactivated)
 762                                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 763                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 764                                             plid, reason);
 765                         break;
 766                 case OPN_ACPT:
 767                         llid = sta->llid;
 768                         spin_unlock_bh(&sta->lock);
 769                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 770                                             plid, 0);
 771                         break;
 772                 default:
 773                         spin_unlock_bh(&sta->lock);
 774                         break;
 775                 }
 776                 break;
 777         case PLINK_HOLDING:
 778                 switch (event) {
 779                 case CLS_ACPT:
 780                         if (del_timer(&sta->plink_timer))
 781                                 sta->ignore_plink_timer = 1;
 782                         mesh_plink_fsm_restart(sta);
 783                         spin_unlock_bh(&sta->lock);
 784                         break;
 785                 case OPN_ACPT:
 786                 case CNF_ACPT:
 787                 case OPN_RJCT:
 788                 case CNF_RJCT:
 789                         llid = sta->llid;
 790                         reason = sta->reason;
 791                         spin_unlock_bh(&sta->lock);
 792                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr,
 793                                             llid, plid, reason);
 794                         break;
 795                 default:
 796                         spin_unlock_bh(&sta->lock);
 797                 }
 798                 break;
 799         default:
 800                 /* should not get here, PLINK_BLOCKED is dealt with at the
 801                  * beginning of the function
 802                  */
 803                 spin_unlock_bh(&sta->lock);
 804                 break;
 805         }
 806
 807         rcu_read_unlock();
 808 }