net/mac80211/mesh_plink.c

   1 /*
   2  * Copyright (c) 2008 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/kernel.h>
  10 #include <linux/random.h>
  11 #include "ieee80211_i.h"
  12 #include "rate.h"
  13 #include "mesh.h"
  14
  15 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
  16 #define mpl_dbg(fmt, args...)   printk(KERN_DEBUG fmt, ##args)
  17 #else
  18 #define mpl_dbg(fmt, args...)   do { (void)(0); } while (0)
  19 #endif
  20
  21 #define PLINK_GET_FRAME_SUBTYPE(p) (p)
  22 #define PLINK_GET_LLID(p) (p + 1)
  23 #define PLINK_GET_PLID(p) (p + 3)
  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: mes 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, u64 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_ATOMIC);
 105         if (!sta)
 106                 return NULL;
 107
 108         sta->flags = WLAN_STA_AUTHORIZED;
 109         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 110
 111         return sta;
 112 }
 113
 114 /**
 115  * mesh_plink_deactivate - deactivate mesh peer link
 116  *
 117  * @sta: mesh peer link to deactivate
 118  *
 119  * All mesh paths with this peer as next hop will be flushed
 120  *
 121  * Locking: the caller must hold sta->lock
 122  */
 123 static void __mesh_plink_deactivate(struct sta_info *sta)
 124 {
 125         struct ieee80211_sub_if_data *sdata = sta->sdata;
 126
 127         if (sta->plink_state == PLINK_ESTAB)
 128                 mesh_plink_dec_estab_count(sdata);
 129         sta->plink_state = PLINK_BLOCKED;
 130         mesh_path_flush_by_nexthop(sta);
 131 }
 132
 133 /**
 134  * __mesh_plink_deactivate - deactivate mesh peer link
 135  *
 136  * @sta: mesh peer link to deactivate
 137  *
 138  * All mesh paths with this peer as next hop will be flushed
 139  */
 140 void mesh_plink_deactivate(struct sta_info *sta)
 141 {
 142         spin_lock_bh(&sta->lock);
 143         __mesh_plink_deactivate(sta);
 144         spin_unlock_bh(&sta->lock);
 145 }
 146
 147 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 148                 enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,
 149                 __le16 reason) {
 150         struct ieee80211_local *local = sdata->local;
 151         struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
 152         struct ieee80211_mgmt *mgmt;
 153         bool include_plid = false;
 154         u8 *pos;
 155         int ie_len;
 156
 157         if (!skb)
 158                 return -1;
 159         skb_reserve(skb, local->hw.extra_tx_headroom);
 160         /* 25 is the size of the common mgmt part (24) plus the size of the
 161          * common action part (1)
 162          */
 163         mgmt = (struct ieee80211_mgmt *)
 164                 skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));
 165         memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));
 166         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 167                                           IEEE80211_STYPE_ACTION);
 168         memcpy(mgmt->da, da, ETH_ALEN);
 169         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
 170         /* BSSID is left zeroed, wildcard value */
 171         mgmt->u.action.category = PLINK_CATEGORY;
 172         mgmt->u.action.u.plink_action.action_code = action;
 173
 174         if (action == PLINK_CLOSE)
 175                 mgmt->u.action.u.plink_action.aux = reason;
 176         else {
 177                 mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);
 178                 if (action == PLINK_CONFIRM) {
 179                         pos = skb_put(skb, 4);
 180                         /* two-byte status code followed by two-byte AID */
 181                         memset(pos, 0, 4);
 182                 }
 183                 mesh_mgmt_ies_add(skb, sdata);
 184         }
 185
 186         /* Add Peer Link Management element */
 187         switch (action) {
 188         case PLINK_OPEN:
 189                 ie_len = 3;
 190                 break;
 191         case PLINK_CONFIRM:
 192                 ie_len = 5;
 193                 include_plid = true;
 194                 break;
 195         case PLINK_CLOSE:
 196         default:
 197                 if (!plid)
 198                         ie_len = 5;
 199                 else {
 200                         ie_len = 7;
 201                         include_plid = true;
 202                 }
 203                 break;
 204         }
 205
 206         pos = skb_put(skb, 2 + ie_len);
 207         *pos++ = WLAN_EID_PEER_LINK;
 208         *pos++ = ie_len;
 209         *pos++ = action;
 210         memcpy(pos, &llid, 2);
 211         if (include_plid) {
 212                 pos += 2;
 213                 memcpy(pos, &plid, 2);
 214         }
 215         if (action == PLINK_CLOSE) {
 216                 pos += 2;
 217                 memcpy(pos, &reason, 2);
 218         }
 219
 220         ieee80211_tx_skb(sdata, skb, 0);
 221         return 0;
 222 }
 223
 224 void mesh_neighbour_update(u8 *hw_addr, u64 rates, struct ieee80211_sub_if_data *sdata,
 225                            bool peer_accepting_plinks)
 226 {
 227         struct ieee80211_local *local = sdata->local;
 228         struct sta_info *sta;
 229
 230         rcu_read_lock();
 231
 232         sta = sta_info_get(local, hw_addr);
 233         if (!sta) {
 234                 sta = mesh_plink_alloc(sdata, hw_addr, rates);
 235                 if (!sta) {
 236                         rcu_read_unlock();
 237                         return;
 238                 }
 239                 if (sta_info_insert(sta)) {
 240                         rcu_read_unlock();
 241                         return;
 242                 }
 243         }
 244
 245         sta->last_rx = jiffies;
 246         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 247         if (peer_accepting_plinks && sta->plink_state == PLINK_LISTEN &&
 248                         sdata->u.mesh.accepting_plinks &&
 249                         sdata->u.mesh.mshcfg.auto_open_plinks)
 250                 mesh_plink_open(sta);
 251
 252         rcu_read_unlock();
 253 }
 254
 255 static void mesh_plink_timer(unsigned long data)
 256 {
 257         struct sta_info *sta;
 258         __le16 llid, plid, reason;
 259         struct ieee80211_sub_if_data *sdata;
 260
 261         /*
 262          * This STA is valid because sta_info_destroy() will
 263          * del_timer_sync() this timer after having made sure
 264          * it cannot be readded (by deleting the plink.)
 265          */
 266         sta = (struct sta_info *) data;
 267
 268         spin_lock_bh(&sta->lock);
 269         if (sta->ignore_plink_timer) {
 270                 sta->ignore_plink_timer = false;
 271                 spin_unlock_bh(&sta->lock);
 272                 return;
 273         }
 274         mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
 275                 sta->sta.addr, sta->plink_state);
 276         reason = 0;
 277         llid = sta->llid;
 278         plid = sta->plid;
 279         sdata = sta->sdata;
 280
 281         switch (sta->plink_state) {
 282         case PLINK_OPN_RCVD:
 283         case PLINK_OPN_SNT:
 284                 /* retry timer */
 285                 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
 286                         u32 rand;
 287                         mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
 288                                 sta->sta.addr, sta->plink_retries,
 289                                 sta->plink_timeout);
 290                         get_random_bytes(&rand, sizeof(u32));
 291                         sta->plink_timeout = sta->plink_timeout +
 292                                              rand % sta->plink_timeout;
 293                         ++sta->plink_retries;
 294                         mod_plink_timer(sta, sta->plink_timeout);
 295                         spin_unlock_bh(&sta->lock);
 296                         mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
 297                                             0, 0);
 298                         break;
 299                 }
 300                 reason = cpu_to_le16(MESH_MAX_RETRIES);
 301                 /* fall through on else */
 302         case PLINK_CNF_RCVD:
 303                 /* confirm timer */
 304                 if (!reason)
 305                         reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
 306                 sta->plink_state = PLINK_HOLDING;
 307                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 308                 spin_unlock_bh(&sta->lock);
 309                 mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid, plid,
 310                                     reason);
 311                 break;
 312         case PLINK_HOLDING:
 313                 /* holding timer */
 314                 del_timer(&sta->plink_timer);
 315                 mesh_plink_fsm_restart(sta);
 316                 spin_unlock_bh(&sta->lock);
 317                 break;
 318         default:
 319                 spin_unlock_bh(&sta->lock);
 320                 break;
 321         }
 322 }
 323
 324 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 325 {
 326         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 327         sta->plink_timer.data = (unsigned long) sta;
 328         sta->plink_timer.function = mesh_plink_timer;
 329         sta->plink_timeout = timeout;
 330         add_timer(&sta->plink_timer);
 331 }
 332
 333 int mesh_plink_open(struct sta_info *sta)
 334 {
 335         __le16 llid;
 336         struct ieee80211_sub_if_data *sdata = sta->sdata;
 337
 338         spin_lock_bh(&sta->lock);
 339         get_random_bytes(&llid, 2);
 340         sta->llid = llid;
 341         if (sta->plink_state != PLINK_LISTEN) {
 342                 spin_unlock_bh(&sta->lock);
 343                 return -EBUSY;
 344         }
 345         sta->plink_state = PLINK_OPN_SNT;
 346         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 347         spin_unlock_bh(&sta->lock);
 348         mpl_dbg("Mesh plink: starting establishment with %pM\n",
 349                 sta->sta.addr);
 350
 351         return mesh_plink_frame_tx(sdata, PLINK_OPEN,
 352                                    sta->sta.addr, llid, 0, 0);
 353 }
 354
 355 void mesh_plink_block(struct sta_info *sta)
 356 {
 357         spin_lock_bh(&sta->lock);
 358         __mesh_plink_deactivate(sta);
 359         sta->plink_state = PLINK_BLOCKED;
 360         spin_unlock_bh(&sta->lock);
 361 }
 362
 363 int mesh_plink_close(struct sta_info *sta)
 364 {
 365         struct ieee80211_sub_if_data *sdata = sta->sdata;
 366         __le16 llid, plid, reason;
 367
 368         mpl_dbg("Mesh plink: closing link with %pM\n", sta->sta.addr);
 369         spin_lock_bh(&sta->lock);
 370         sta->reason = cpu_to_le16(MESH_LINK_CANCELLED);
 371         reason = sta->reason;
 372
 373         if (sta->plink_state == PLINK_LISTEN ||
 374             sta->plink_state == PLINK_BLOCKED) {
 375                 mesh_plink_fsm_restart(sta);
 376                 spin_unlock_bh(&sta->lock);
 377                 return 0;
 378         } else if (sta->plink_state == PLINK_ESTAB) {
 379                 __mesh_plink_deactivate(sta);
 380                 /* The timer should not be running */
 381                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 382         } else if (!mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata)))
 383                 sta->ignore_plink_timer = true;
 384
 385         sta->plink_state = PLINK_HOLDING;
 386         llid = sta->llid;
 387         plid = sta->plid;
 388         spin_unlock_bh(&sta->lock);
 389         mesh_plink_frame_tx(sta->sdata, PLINK_CLOSE, sta->sta.addr, llid,
 390                             plid, reason);
 391         return 0;
 392 }
 393
 394 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 395                          size_t len, struct ieee80211_rx_status *rx_status)
 396 {
 397         struct ieee80211_local *local = sdata->local;
 398         struct ieee802_11_elems elems;
 399         struct sta_info *sta;
 400         enum plink_event event;
 401         enum plink_frame_type ftype;
 402         size_t baselen;
 403         u8 ie_len;
 404         u8 *baseaddr;
 405         __le16 plid, llid, reason;
 406
 407         /* need action_code, aux */
 408         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 409                 return;
 410
 411         if (is_multicast_ether_addr(mgmt->da)) {
 412                 mpl_dbg("Mesh plink: ignore frame from multicast address");
 413                 return;
 414         }
 415
 416         baseaddr = mgmt->u.action.u.plink_action.variable;
 417         baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;
 418         if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {
 419                 baseaddr += 4;
 420                 baselen -= 4;
 421         }
 422         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 423         if (!elems.peer_link) {
 424                 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
 425                 return;
 426         }
 427
 428         ftype = *((u8 *)PLINK_GET_FRAME_SUBTYPE(elems.peer_link));
 429         ie_len = elems.peer_link_len;
 430         if ((ftype == PLINK_OPEN && ie_len != 3) ||
 431             (ftype == PLINK_CONFIRM && ie_len != 5) ||
 432             (ftype == PLINK_CLOSE && ie_len != 5 && ie_len != 7)) {
 433                 mpl_dbg("Mesh plink: incorrect plink ie length\n");
 434                 return;
 435         }
 436
 437         if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
 438                 mpl_dbg("Mesh plink: missing necessary ie\n");
 439                 return;
 440         }
 441         /* Note the lines below are correct, the llid in the frame is the plid
 442          * from the point of view of this host.
 443          */
 444         memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
 445         if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 7))
 446                 memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
 447
 448         rcu_read_lock();
 449
 450         sta = sta_info_get(local, mgmt->sa);
 451         if (!sta && ftype != PLINK_OPEN) {
 452                 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
 453                 rcu_read_unlock();
 454                 return;
 455         }
 456
 457         if (sta && sta->plink_state == PLINK_BLOCKED) {
 458                 rcu_read_unlock();
 459                 return;
 460         }
 461
 462         /* Now we will figure out the appropriate event... */
 463         event = PLINK_UNDEFINED;
 464         if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) {
 465                 switch (ftype) {
 466                 case PLINK_OPEN:
 467                         event = OPN_RJCT;
 468                         break;
 469                 case PLINK_CONFIRM:
 470                         event = CNF_RJCT;
 471                         break;
 472                 case PLINK_CLOSE:
 473                         /* avoid warning */
 474                         break;
 475                 }
 476                 spin_lock_bh(&sta->lock);
 477         } else if (!sta) {
 478                 /* ftype == PLINK_OPEN */
 479                 u64 rates;
 480                 if (!mesh_plink_free_count(sdata)) {
 481                         mpl_dbg("Mesh plink error: no more free plinks\n");
 482                         rcu_read_unlock();
 483                         return;
 484                 }
 485
 486                 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
 487                 sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
 488                 if (!sta) {
 489                         mpl_dbg("Mesh plink error: plink table full\n");
 490                         rcu_read_unlock();
 491                         return;
 492                 }
 493                 if (sta_info_insert(sta)) {
 494                         rcu_read_unlock();
 495                         return;
 496                 }
 497                 event = OPN_ACPT;
 498                 spin_lock_bh(&sta->lock);
 499         } else {
 500                 spin_lock_bh(&sta->lock);
 501                 switch (ftype) {
 502                 case PLINK_OPEN:
 503                         if (!mesh_plink_free_count(sdata) ||
 504                             (sta->plid && sta->plid != plid))
 505                                 event = OPN_IGNR;
 506                         else
 507                                 event = OPN_ACPT;
 508                         break;
 509                 case PLINK_CONFIRM:
 510                         if (!mesh_plink_free_count(sdata) ||
 511                             (sta->llid != llid || sta->plid != plid))
 512                                 event = CNF_IGNR;
 513                         else
 514                                 event = CNF_ACPT;
 515                         break;
 516                 case PLINK_CLOSE:
 517                         if (sta->plink_state == PLINK_ESTAB)
 518                                 /* Do not check for llid or plid. This does not
 519                                  * follow the standard but since multiple plinks
 520                                  * per sta are not supported, it is necessary in
 521                                  * order to avoid a livelock when MP A sees an
 522                                  * establish peer link to MP B but MP B does not
 523                                  * see it. This can be caused by a timeout in
 524                                  * B's peer link establishment or B beign
 525                                  * restarted.
 526                                  */
 527                                 event = CLS_ACPT;
 528                         else if (sta->plid != plid)
 529                                 event = CLS_IGNR;
 530                         else if (ie_len == 7 && sta->llid != llid)
 531                                 event = CLS_IGNR;
 532                         else
 533                                 event = CLS_ACPT;
 534                         break;
 535                 default:
 536                         mpl_dbg("Mesh plink: unknown frame subtype\n");
 537                         spin_unlock_bh(&sta->lock);
 538                         rcu_read_unlock();
 539                         return;
 540                 }
 541         }
 542
 543         mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %d %d %d %d\n",
 544                 mgmt->sa, sta->plink_state,
 545                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 546                 event);
 547         reason = 0;
 548         switch (sta->plink_state) {
 549                 /* spin_unlock as soon as state is updated at each case */
 550         case PLINK_LISTEN:
 551                 switch (event) {
 552                 case CLS_ACPT:
 553                         mesh_plink_fsm_restart(sta);
 554                         spin_unlock_bh(&sta->lock);
 555                         break;
 556                 case OPN_ACPT:
 557                         sta->plink_state = PLINK_OPN_RCVD;
 558                         sta->plid = plid;
 559                         get_random_bytes(&llid, 2);
 560                         sta->llid = llid;
 561                         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 562                         spin_unlock_bh(&sta->lock);
 563                         mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
 564                                             0, 0);
 565                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr,
 566                                             llid, plid, 0);
 567                         break;
 568                 default:
 569                         spin_unlock_bh(&sta->lock);
 570                         break;
 571                 }
 572                 break;
 573
 574         case PLINK_OPN_SNT:
 575                 switch (event) {
 576                 case OPN_RJCT:
 577                 case CNF_RJCT:
 578                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 579                 case CLS_ACPT:
 580                         if (!reason)
 581                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 582                         sta->reason = reason;
 583                         sta->plink_state = PLINK_HOLDING;
 584                         if (!mod_plink_timer(sta,
 585                                              dot11MeshHoldingTimeout(sdata)))
 586                                 sta->ignore_plink_timer = true;
 587
 588                         llid = sta->llid;
 589                         spin_unlock_bh(&sta->lock);
 590                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 591                                             plid, reason);
 592                         break;
 593                 case OPN_ACPT:
 594                         /* retry timer is left untouched */
 595                         sta->plink_state = PLINK_OPN_RCVD;
 596                         sta->plid = plid;
 597                         llid = sta->llid;
 598                         spin_unlock_bh(&sta->lock);
 599                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 600                                             plid, 0);
 601                         break;
 602                 case CNF_ACPT:
 603                         sta->plink_state = PLINK_CNF_RCVD;
 604                         if (!mod_plink_timer(sta,
 605                                              dot11MeshConfirmTimeout(sdata)))
 606                                 sta->ignore_plink_timer = true;
 607
 608                         spin_unlock_bh(&sta->lock);
 609                         break;
 610                 default:
 611                         spin_unlock_bh(&sta->lock);
 612                         break;
 613                 }
 614                 break;
 615
 616         case PLINK_OPN_RCVD:
 617                 switch (event) {
 618                 case OPN_RJCT:
 619                 case CNF_RJCT:
 620                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 621                 case CLS_ACPT:
 622                         if (!reason)
 623                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 624                         sta->reason = reason;
 625                         sta->plink_state = PLINK_HOLDING;
 626                         if (!mod_plink_timer(sta,
 627                                              dot11MeshHoldingTimeout(sdata)))
 628                                 sta->ignore_plink_timer = true;
 629
 630                         llid = sta->llid;
 631                         spin_unlock_bh(&sta->lock);
 632                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 633                                             plid, reason);
 634                         break;
 635                 case OPN_ACPT:
 636                         llid = sta->llid;
 637                         spin_unlock_bh(&sta->lock);
 638                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 639                                             plid, 0);
 640                         break;
 641                 case CNF_ACPT:
 642                         del_timer(&sta->plink_timer);
 643                         sta->plink_state = PLINK_ESTAB;
 644                         mesh_plink_inc_estab_count(sdata);
 645                         spin_unlock_bh(&sta->lock);
 646                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 647                                 sta->sta.addr);
 648                         break;
 649                 default:
 650                         spin_unlock_bh(&sta->lock);
 651                         break;
 652                 }
 653                 break;
 654
 655         case PLINK_CNF_RCVD:
 656                 switch (event) {
 657                 case OPN_RJCT:
 658                 case CNF_RJCT:
 659                         reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
 660                 case CLS_ACPT:
 661                         if (!reason)
 662                                 reason = cpu_to_le16(MESH_CLOSE_RCVD);
 663                         sta->reason = reason;
 664                         sta->plink_state = PLINK_HOLDING;
 665                         if (!mod_plink_timer(sta,
 666                                              dot11MeshHoldingTimeout(sdata)))
 667                                 sta->ignore_plink_timer = true;
 668
 669                         llid = sta->llid;
 670                         spin_unlock_bh(&sta->lock);
 671                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 672                                             plid, reason);
 673                         break;
 674                 case OPN_ACPT:
 675                         del_timer(&sta->plink_timer);
 676                         sta->plink_state = PLINK_ESTAB;
 677                         mesh_plink_inc_estab_count(sdata);
 678                         spin_unlock_bh(&sta->lock);
 679                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 680                                 sta->sta.addr);
 681                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 682                                             plid, 0);
 683                         break;
 684                 default:
 685                         spin_unlock_bh(&sta->lock);
 686                         break;
 687                 }
 688                 break;
 689
 690         case PLINK_ESTAB:
 691                 switch (event) {
 692                 case CLS_ACPT:
 693                         reason = cpu_to_le16(MESH_CLOSE_RCVD);
 694                         sta->reason = reason;
 695                         __mesh_plink_deactivate(sta);
 696                         sta->plink_state = PLINK_HOLDING;
 697                         llid = sta->llid;
 698                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 699                         spin_unlock_bh(&sta->lock);
 700                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
 701                                             plid, reason);
 702                         break;
 703                 case OPN_ACPT:
 704                         llid = sta->llid;
 705                         spin_unlock_bh(&sta->lock);
 706                         mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
 707                                             plid, 0);
 708                         break;
 709                 default:
 710                         spin_unlock_bh(&sta->lock);
 711                         break;
 712                 }
 713                 break;
 714         case PLINK_HOLDING:
 715                 switch (event) {
 716                 case CLS_ACPT:
 717                         if (del_timer(&sta->plink_timer))
 718                                 sta->ignore_plink_timer = 1;
 719                         mesh_plink_fsm_restart(sta);
 720                         spin_unlock_bh(&sta->lock);
 721                         break;
 722                 case OPN_ACPT:
 723                 case CNF_ACPT:
 724                 case OPN_RJCT:
 725                 case CNF_RJCT:
 726                         llid = sta->llid;
 727                         reason = sta->reason;
 728                         spin_unlock_bh(&sta->lock);
 729                         mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr,
 730                                             llid, plid, reason);
 731                         break;
 732                 default:
 733                         spin_unlock_bh(&sta->lock);
 734                 }
 735                 break;
 736         default:
 737                 /* should not get here, PLINK_BLOCKED is dealt with at the
 738                  * beggining of the function
 739                  */
 740                 spin_unlock_bh(&sta->lock);
 741                 break;
 742         }
 743
 744         rcu_read_unlock();
 745 }