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 = 1,
  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 = NL80211_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 == NL80211_PLINK_ESTAB) {
 130                 mesh_plink_dec_estab_count(sdata);
 131                 deactivated = true;
 132         }
 133         sta->plink_state = NL80211_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         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 185         mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
 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.security & IEEE80211_MESH_SEC_AUTHED)
 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 == NL80211_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 NL80211_PLINK_OPN_RCVD:
 312         case NL80211_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 NL80211_PLINK_CNF_RCVD:
 332                 /* confirm timer */
 333                 if (!reason)
 334                         reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
 335                 sta->plink_state = NL80211_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 NL80211_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 != NL80211_PLINK_LISTEN) {
 390                 spin_unlock_bh(&sta->lock);
 391                 return -EBUSY;
 392         }
 393         sta->plink_state = NL80211_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 = NL80211_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                 [NL80211_PLINK_LISTEN] = "LISTEN",
 434                 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 435                 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 436                 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 437                 [NL80211_PLINK_ESTAB] = "ESTAB",
 438                 [NL80211_PLINK_HOLDING] = "HOLDING",
 439                 [NL80211_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 &&
 464                         sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 465                 mpl_dbg("Mesh plink: can't establish link with secure peer\n");
 466                 return;
 467         }
 468
 469         ftype = mgmt->u.action.u.plink_action.action_code;
 470         ie_len = elems.peer_link_len;
 471         if ((ftype == PLINK_OPEN && ie_len != 6) ||
 472             (ftype == PLINK_CONFIRM && ie_len != 8) ||
 473             (ftype == PLINK_CLOSE && ie_len != 8 && ie_len != 10)) {
 474                 mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
 475                     ftype, ie_len);
 476                 return;
 477         }
 478
 479         if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
 480                 mpl_dbg("Mesh plink: missing necessary ie\n");
 481                 return;
 482         }
 483         /* Note the lines below are correct, the llid in the frame is the plid
 484          * from the point of view of this host.
 485          */
 486         memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
 487         if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 10))
 488                 memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
 489
 490         rcu_read_lock();
 491
 492         sta = sta_info_get(sdata, mgmt->sa);
 493         if (!sta && ftype != PLINK_OPEN) {
 494                 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
 495                 rcu_read_unlock();
 496                 return;
 497         }
 498
 499         if (sta && !test_sta_flags(sta, WLAN_STA_AUTH)) {
 500                 mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
 501                 rcu_read_unlock();
 502                 return;
 503         }
 504
 505         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 506                 rcu_read_unlock();
 507                 return;
 508         }
 509
 510         /* Now we will figure out the appropriate event... */
 511         event = PLINK_UNDEFINED;
 512         if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) {
 513                 matches_local = false;
 514                 switch (ftype) {
 515                 case PLINK_OPEN:
 516                         event = OPN_RJCT;
 517                         break;
 518                 case PLINK_CONFIRM:
 519                         event = CNF_RJCT;
 520                         break;
 521                 case PLINK_CLOSE:
 522                         /* avoid warning */
 523                         break;
 524                 }
 525         }
 526
 527         if (!sta && !matches_local) {
 528                 rcu_read_unlock();
 529                 reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 530                 llid = 0;
 531                 mesh_plink_frame_tx(sdata, PLINK_CLOSE, mgmt->sa, llid,
 532                                     plid, reason);
 533                 return;
 534         } else if (!sta) {
 535                 /* ftype == PLINK_OPEN */
 536                 u32 rates;
 537
 538                 rcu_read_unlock();
 539
 540                 if (!mesh_plink_free_count(sdata)) {
 541                         mpl_dbg("Mesh plink error: no more free plinks\n");
 542                         return;
 543                 }
 544
 545                 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
 546                 sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
 547                 if (!sta) {
 548                         mpl_dbg("Mesh plink error: plink table full\n");
 549                         return;
 550                 }
 551                 if (sta_info_insert_rcu(sta)) {
 552                         rcu_read_unlock();
 553                         return;
 554                 }
 555                 event = OPN_ACPT;
 556                 spin_lock_bh(&sta->lock);
 557         } else if (matches_local) {
 558                 spin_lock_bh(&sta->lock);
 559                 switch (ftype) {
 560                 case PLINK_OPEN:
 561                         if (!mesh_plink_free_count(sdata) ||
 562                             (sta->plid && sta->plid != plid))
 563                                 event = OPN_IGNR;
 564                         else
 565                                 event = OPN_ACPT;
 566                         break;
 567                 case PLINK_CONFIRM:
 568                         if (!mesh_plink_free_count(sdata) ||
 569                             (sta->llid != llid || sta->plid != plid))
 570                                 event = CNF_IGNR;
 571                         else
 572                                 event = CNF_ACPT;
 573                         break;
 574                 case PLINK_CLOSE:
 575                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 576                                 /* Do not check for llid or plid. This does not
 577                                  * follow the standard but since multiple plinks
 578                                  * per sta are not supported, it is necessary in
 579                                  * order to avoid a livelock when MP A sees an
 580                                  * establish peer link to MP B but MP B does not
 581                                  * see it. This can be caused by a timeout in
 582                                  * B's peer link establishment or B beign
 583                                  * restarted.
 584                                  */
 585                                 event = CLS_ACPT;
 586                         else if (sta->plid != plid)
 587                                 event = CLS_IGNR;
 588                         else if (ie_len == 7 && sta->llid != llid)
 589                                 event = CLS_IGNR;
 590                         else
 591                                 event = CLS_ACPT;
 592                         break;
 593                 default:
 594                         mpl_dbg("Mesh plink: unknown frame subtype\n");
 595                         spin_unlock_bh(&sta->lock);
 596                         rcu_read_unlock();
 597                         return;
 598                 }
 599         } else {
 600                 spin_lock_bh(&sta->lock);
 601         }
 602
 603         mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 604                 mgmt->sa, mplstates[sta->plink_state],
 605                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 606                 event);
 607         reason = 0;
 608         switch (sta->plink_state) {
 609                 /* spin_unlock as soon as state is updated at each case */
 610         case NL80211_PLINK_LISTEN:
 611                 switch (event) {
 612                 case CLS_ACPT:
 613                         mesh_plink_fsm_restart(sta);
 614                         spin_unlock_bh(&sta->lock);
 615                         break;
 616                 case OPN_ACPT:
 617                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 618                         sta->plid = plid;
 619                         get_random_bytes(&llid, 2);
 620                         sta->llid = llid;
 621                         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 622                         spin_unlock_bh(&sta->lock);
 623                         mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
 624                                             0, 0);
 625                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr,
 626                                             llid, plid, 0);
 627                         break;
 628                 default:
 629                         spin_unlock_bh(&sta->lock);
 630                         break;
 631                 }
 632                 break;
 633
 634         case NL80211_PLINK_OPN_SNT:
 635                 switch (event) {
 636                 case OPN_RJCT:
 637                 case CNF_RJCT:
 638                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 639                 case CLS_ACPT:
 640                         if (!reason)
 641                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 642                         sta->reason = reason;
 643                         sta->plink_state = NL80211_PLINK_HOLDING;
 644                         if (!mod_plink_timer(sta,
 645                                              dot11MeshHoldingTimeout(sdata)))
 646                                 sta->ignore_plink_timer = true;
 647
 648                         llid = sta->llid;
 649                         spin_unlock_bh(&sta->lock);
 650                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 651                                             plid, reason);
 652                         break;
 653                 case OPN_ACPT:
 654                         /* retry timer is left untouched */
 655                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 656                         sta->plid = plid;
 657                         llid = sta->llid;
 658                         spin_unlock_bh(&sta->lock);
 659                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 660                                             plid, 0);
 661                         break;
 662                 case CNF_ACPT:
 663                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 664                         if (!mod_plink_timer(sta,
 665                                              dot11MeshConfirmTimeout(sdata)))
 666                                 sta->ignore_plink_timer = true;
 667
 668                         spin_unlock_bh(&sta->lock);
 669                         break;
 670                 default:
 671                         spin_unlock_bh(&sta->lock);
 672                         break;
 673                 }
 674                 break;
 675
 676         case NL80211_PLINK_OPN_RCVD:
 677                 switch (event) {
 678                 case OPN_RJCT:
 679                 case CNF_RJCT:
 680                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 681                 case CLS_ACPT:
 682                         if (!reason)
 683                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 684                         sta->reason = reason;
 685                         sta->plink_state = NL80211_PLINK_HOLDING;
 686                         if (!mod_plink_timer(sta,
 687                                              dot11MeshHoldingTimeout(sdata)))
 688                                 sta->ignore_plink_timer = true;
 689
 690                         llid = sta->llid;
 691                         spin_unlock_bh(&sta->lock);
 692                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 693                                             plid, reason);
 694                         break;
 695                 case OPN_ACPT:
 696                         llid = sta->llid;
 697                         spin_unlock_bh(&sta->lock);
 698                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 699                                             plid, 0);
 700                         break;
 701                 case CNF_ACPT:
 702                         del_timer(&sta->plink_timer);
 703                         sta->plink_state = NL80211_PLINK_ESTAB;
 704                         spin_unlock_bh(&sta->lock);
 705                         mesh_plink_inc_estab_count(sdata);
 706                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 707                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 708                                 sta->sta.addr);
 709                         break;
 710                 default:
 711                         spin_unlock_bh(&sta->lock);
 712                         break;
 713                 }
 714                 break;
 715
 716         case NL80211_PLINK_CNF_RCVD:
 717                 switch (event) {
 718                 case OPN_RJCT:
 719                 case CNF_RJCT:
 720                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 721                 case CLS_ACPT:
 722                         if (!reason)
 723                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 724                         sta->reason = reason;
 725                         sta->plink_state = NL80211_PLINK_HOLDING;
 726                         if (!mod_plink_timer(sta,
 727                                              dot11MeshHoldingTimeout(sdata)))
 728                                 sta->ignore_plink_timer = true;
 729
 730                         llid = sta->llid;
 731                         spin_unlock_bh(&sta->lock);
 732                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 733                                             plid, reason);
 734                         break;
 735                 case OPN_ACPT:
 736                         del_timer(&sta->plink_timer);
 737                         sta->plink_state = NL80211_PLINK_ESTAB;
 738                         spin_unlock_bh(&sta->lock);
 739                         mesh_plink_inc_estab_count(sdata);
 740                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 741                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 742                                 sta->sta.addr);
 743                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 744                                             plid, 0);
 745                         break;
 746                 default:
 747                         spin_unlock_bh(&sta->lock);
 748                         break;
 749                 }
 750                 break;
 751
 752         case NL80211_PLINK_ESTAB:
 753                 switch (event) {
 754                 case CLS_ACPT:
 755                         reason = cpu_to_le16(MESH_CLOSE_RCVD);
 756                         sta->reason = reason;
 757                         deactivated = __mesh_plink_deactivate(sta);
 758                         sta->plink_state = NL80211_PLINK_HOLDING;
 759                         llid = sta->llid;
 760                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 761                         spin_unlock_bh(&sta->lock);
 762                         if (deactivated)
 763                                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 764                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 765                                             plid, reason);
 766                         break;
 767                 case OPN_ACPT:
 768                         llid = sta->llid;
 769                         spin_unlock_bh(&sta->lock);
 770                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 771                                             plid, 0);
 772                         break;
 773                 default:
 774                         spin_unlock_bh(&sta->lock);
 775                         break;
 776                 }
 777                 break;
 778         case NL80211_PLINK_HOLDING:
 779                 switch (event) {
 780                 case CLS_ACPT:
 781                         if (del_timer(&sta->plink_timer))
 782                                 sta->ignore_plink_timer = 1;
 783                         mesh_plink_fsm_restart(sta);
 784                         spin_unlock_bh(&sta->lock);
 785                         break;
 786                 case OPN_ACPT:
 787                 case CNF_ACPT:
 788                 case OPN_RJCT:
 789                 case CNF_RJCT:
 790                         llid = sta->llid;
 791                         reason = sta->reason;
 792                         spin_unlock_bh(&sta->lock);
 793                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr,
 794                                             llid, plid, reason);
 795                         break;
 796                 default:
 797                         spin_unlock_bh(&sta->lock);
 798                 }
 799                 break;
 800         default:
 801                 /* should not get here, PLINK_BLOCKED is dealt with at the
 802                  * beginning of the function
 803                  */
 804                 spin_unlock_bh(&sta->lock);
 805                 break;
 806         }
 807
 808         rcu_read_unlock();
 809 }