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 + 2)
  23 #define PLINK_GET_PLID(p) (p + 4)
  24
  25 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
  26                                 jiffies + HZ * t / 1000))
  27
  28 #define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
  29 #define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
  30 #define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
  31 #define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
  32 #define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
  33
  34 enum plink_event {
  35         PLINK_UNDEFINED,
  36         OPN_ACPT,
  37         OPN_RJCT,
  38         OPN_IGNR,
  39         CNF_ACPT,
  40         CNF_RJCT,
  41         CNF_IGNR,
  42         CLS_ACPT,
  43         CLS_IGNR
  44 };
  45
  46 static inline
  47 void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
  48 {
  49         atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
  50         mesh_accept_plinks_update(sdata);
  51 }
  52
  53 static inline
  54 void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
  55 {
  56         atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
  57         mesh_accept_plinks_update(sdata);
  58 }
  59
  60 /**
  61  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  62  *
  63  * @sta: mesh peer link to restart
  64  *
  65  * Locking: this function must be called holding sta->lock
  66  */
  67 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  68 {
  69         sta->plink_state = NL80211_PLINK_LISTEN;
  70         sta->llid = sta->plid = sta->reason = 0;
  71         sta->plink_retries = 0;
  72 }
  73
  74 /*
  75  * NOTE: This is just an alias for sta_info_alloc(), see notes
  76  *       on it in the lifecycle management section!
  77  */
  78 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
  79                                          u8 *hw_addr, u32 rates)
  80 {
  81         struct ieee80211_local *local = sdata->local;
  82         struct sta_info *sta;
  83
  84         if (local->num_sta >= MESH_MAX_PLINKS)
  85                 return NULL;
  86
  87         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
  88         if (!sta)
  89                 return NULL;
  90
  91         sta->flags = WLAN_STA_AUTHORIZED | WLAN_STA_AUTH | WLAN_STA_WME;
  92         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
  93         rate_control_rate_init(sta);
  94
  95         return sta;
  96 }
  97
  98 /**
  99  * __mesh_plink_deactivate - deactivate mesh peer link
 100  *
 101  * @sta: mesh peer link to deactivate
 102  *
 103  * All mesh paths with this peer as next hop will be flushed
 104  *
 105  * Locking: the caller must hold sta->lock
 106  */
 107 static bool __mesh_plink_deactivate(struct sta_info *sta)
 108 {
 109         struct ieee80211_sub_if_data *sdata = sta->sdata;
 110         bool deactivated = false;
 111
 112         if (sta->plink_state == NL80211_PLINK_ESTAB) {
 113                 mesh_plink_dec_estab_count(sdata);
 114                 deactivated = true;
 115         }
 116         sta->plink_state = NL80211_PLINK_BLOCKED;
 117         mesh_path_flush_by_nexthop(sta);
 118
 119         return deactivated;
 120 }
 121
 122 /**
 123  * mesh_plink_deactivate - deactivate mesh peer link
 124  *
 125  * @sta: mesh peer link to deactivate
 126  *
 127  * All mesh paths with this peer as next hop will be flushed
 128  */
 129 void mesh_plink_deactivate(struct sta_info *sta)
 130 {
 131         struct ieee80211_sub_if_data *sdata = sta->sdata;
 132         bool deactivated;
 133
 134         spin_lock_bh(&sta->lock);
 135         deactivated = __mesh_plink_deactivate(sta);
 136         spin_unlock_bh(&sta->lock);
 137
 138         if (deactivated)
 139                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 140 }
 141
 142 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 143                 enum ieee80211_self_protected_actioncode action,
 144                 u8 *da, __le16 llid, __le16 plid, __le16 reason) {
 145         struct ieee80211_local *local = sdata->local;
 146         struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400 +
 147                         sdata->u.mesh.ie_len);
 148         struct ieee80211_mgmt *mgmt;
 149         bool include_plid = false;
 150         int ie_len = 4;
 151         u16 peering_proto = 0;
 152         u8 *pos;
 153
 154         if (!skb)
 155                 return -1;
 156         skb_reserve(skb, local->hw.extra_tx_headroom);
 157         /* 25 is the size of the common mgmt part (24) plus the size of the
 158          * common action part (1)
 159          */
 160         mgmt = (struct ieee80211_mgmt *)
 161                 skb_put(skb, 25 + sizeof(mgmt->u.action.u.self_prot));
 162         memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.self_prot));
 163         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 164                                           IEEE80211_STYPE_ACTION);
 165         memcpy(mgmt->da, da, ETH_ALEN);
 166         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 167         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 168         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 169         mgmt->u.action.u.self_prot.action_code = action;
 170
 171         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 172                 /* capability info */
 173                 pos = skb_put(skb, 2);
 174                 memset(pos, 0, 2);
 175                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 176                         /* AID */
 177                         pos = skb_put(skb, 2);
 178                         memcpy(pos + 2, &plid, 2);
 179                 }
 180                 if (mesh_add_srates_ie(skb, sdata) ||
 181                     mesh_add_ext_srates_ie(skb, sdata) ||
 182                     mesh_add_rsn_ie(skb, sdata) ||
 183                     mesh_add_meshid_ie(skb, sdata) ||
 184                     mesh_add_meshconf_ie(skb, sdata))
 185                         return -1;
 186         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 187                 if (mesh_add_meshid_ie(skb, sdata))
 188                         return -1;
 189         }
 190
 191         /* Add Mesh Peering Management element */
 192         switch (action) {
 193         case WLAN_SP_MESH_PEERING_OPEN:
 194                 break;
 195         case WLAN_SP_MESH_PEERING_CONFIRM:
 196                 ie_len += 2;
 197                 include_plid = true;
 198                 break;
 199         case WLAN_SP_MESH_PEERING_CLOSE:
 200                 if (plid) {
 201                         ie_len += 2;
 202                         include_plid = true;
 203                 }
 204                 ie_len += 2;    /* reason code */
 205                 break;
 206         default:
 207                 return -EINVAL;
 208         }
 209
 210         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 211                 return -ENOMEM;
 212
 213         pos = skb_put(skb, 2 + ie_len);
 214         *pos++ = WLAN_EID_PEER_MGMT;
 215         *pos++ = ie_len;
 216         memcpy(pos, &peering_proto, 2);
 217         pos += 2;
 218         memcpy(pos, &llid, 2);
 219         pos += 2;
 220         if (include_plid) {
 221                 memcpy(pos, &plid, 2);
 222                 pos += 2;
 223         }
 224         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 225                 memcpy(pos, &reason, 2);
 226                 pos += 2;
 227         }
 228         if (mesh_add_vendor_ies(skb, sdata))
 229                 return -1;
 230
 231         ieee80211_tx_skb(sdata, skb);
 232         return 0;
 233 }
 234
 235 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 236                 struct ieee80211_sub_if_data *sdata,
 237                 struct ieee802_11_elems *elems)
 238 {
 239         struct ieee80211_local *local = sdata->local;
 240         struct sta_info *sta;
 241
 242         rcu_read_lock();
 243
 244         sta = sta_info_get(sdata, hw_addr);
 245         if (!sta) {
 246                 rcu_read_unlock();
 247                 /* Userspace handles peer allocation when security is enabled
 248                  * */
 249                 if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 250                         cfg80211_notify_new_peer_candidate(sdata->dev, hw_addr,
 251                                         elems->ie_start, elems->total_len,
 252                                         GFP_KERNEL);
 253                 else
 254                         sta = mesh_plink_alloc(sdata, hw_addr, rates);
 255                 if (!sta)
 256                         return;
 257                 if (sta_info_insert_rcu(sta)) {
 258                         rcu_read_unlock();
 259                         return;
 260                 }
 261         }
 262
 263         sta->last_rx = jiffies;
 264         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 265         if (mesh_peer_accepts_plinks(elems) &&
 266                         sta->plink_state == NL80211_PLINK_LISTEN &&
 267                         sdata->u.mesh.accepting_plinks &&
 268                         sdata->u.mesh.mshcfg.auto_open_plinks)
 269                 mesh_plink_open(sta);
 270
 271         rcu_read_unlock();
 272 }
 273
 274 static void mesh_plink_timer(unsigned long data)
 275 {
 276         struct sta_info *sta;
 277         __le16 llid, plid, reason;
 278         struct ieee80211_sub_if_data *sdata;
 279
 280         /*
 281          * This STA is valid because sta_info_destroy() will
 282          * del_timer_sync() this timer after having made sure
 283          * it cannot be readded (by deleting the plink.)
 284          */
 285         sta = (struct sta_info *) data;
 286
 287         if (sta->sdata->local->quiescing) {
 288                 sta->plink_timer_was_running = true;
 289                 return;
 290         }
 291
 292         spin_lock_bh(&sta->lock);
 293         if (sta->ignore_plink_timer) {
 294                 sta->ignore_plink_timer = false;
 295                 spin_unlock_bh(&sta->lock);
 296                 return;
 297         }
 298         mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
 299                 sta->sta.addr, sta->plink_state);
 300         reason = 0;
 301         llid = sta->llid;
 302         plid = sta->plid;
 303         sdata = sta->sdata;
 304
 305         switch (sta->plink_state) {
 306         case NL80211_PLINK_OPN_RCVD:
 307         case NL80211_PLINK_OPN_SNT:
 308                 /* retry timer */
 309                 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
 310                         u32 rand;
 311                         mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
 312                                 sta->sta.addr, sta->plink_retries,
 313                                 sta->plink_timeout);
 314                         get_random_bytes(&rand, sizeof(u32));
 315                         sta->plink_timeout = sta->plink_timeout +
 316                                              rand % sta->plink_timeout;
 317                         ++sta->plink_retries;
 318                         mod_plink_timer(sta, sta->plink_timeout);
 319                         spin_unlock_bh(&sta->lock);
 320                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 321                                             sta->sta.addr, llid, 0, 0);
 322                         break;
 323                 }
 324                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 325                 /* fall through on else */
 326         case NL80211_PLINK_CNF_RCVD:
 327                 /* confirm timer */
 328                 if (!reason)
 329                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 330                 sta->plink_state = NL80211_PLINK_HOLDING;
 331                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 332                 spin_unlock_bh(&sta->lock);
 333                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 334                                     sta->sta.addr, llid, plid, reason);
 335                 break;
 336         case NL80211_PLINK_HOLDING:
 337                 /* holding timer */
 338                 del_timer(&sta->plink_timer);
 339                 mesh_plink_fsm_restart(sta);
 340                 spin_unlock_bh(&sta->lock);
 341                 break;
 342         default:
 343                 spin_unlock_bh(&sta->lock);
 344                 break;
 345         }
 346 }
 347
 348 #ifdef CONFIG_PM
 349 void mesh_plink_quiesce(struct sta_info *sta)
 350 {
 351         if (del_timer_sync(&sta->plink_timer))
 352                 sta->plink_timer_was_running = true;
 353 }
 354
 355 void mesh_plink_restart(struct sta_info *sta)
 356 {
 357         if (sta->plink_timer_was_running) {
 358                 add_timer(&sta->plink_timer);
 359                 sta->plink_timer_was_running = false;
 360         }
 361 }
 362 #endif
 363
 364 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 365 {
 366         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 367         sta->plink_timer.data = (unsigned long) sta;
 368         sta->plink_timer.function = mesh_plink_timer;
 369         sta->plink_timeout = timeout;
 370         add_timer(&sta->plink_timer);
 371 }
 372
 373 int mesh_plink_open(struct sta_info *sta)
 374 {
 375         __le16 llid;
 376         struct ieee80211_sub_if_data *sdata = sta->sdata;
 377
 378         if (!test_sta_flags(sta, WLAN_STA_AUTH))
 379                 return -EPERM;
 380
 381         spin_lock_bh(&sta->lock);
 382         get_random_bytes(&llid, 2);
 383         sta->llid = llid;
 384         if (sta->plink_state != NL80211_PLINK_LISTEN) {
 385                 spin_unlock_bh(&sta->lock);
 386                 return -EBUSY;
 387         }
 388         sta->plink_state = NL80211_PLINK_OPN_SNT;
 389         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 390         spin_unlock_bh(&sta->lock);
 391         mpl_dbg("Mesh plink: starting establishment with %pM\n",
 392                 sta->sta.addr);
 393
 394         return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 395                                    sta->sta.addr, llid, 0, 0);
 396 }
 397
 398 void mesh_plink_block(struct sta_info *sta)
 399 {
 400         struct ieee80211_sub_if_data *sdata = sta->sdata;
 401         bool deactivated;
 402
 403         spin_lock_bh(&sta->lock);
 404         deactivated = __mesh_plink_deactivate(sta);
 405         sta->plink_state = NL80211_PLINK_BLOCKED;
 406         spin_unlock_bh(&sta->lock);
 407
 408         if (deactivated)
 409                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 410 }
 411
 412
 413 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 414                          size_t len, struct ieee80211_rx_status *rx_status)
 415 {
 416         struct ieee80211_local *local = sdata->local;
 417         struct ieee802_11_elems elems;
 418         struct sta_info *sta;
 419         enum plink_event event;
 420         enum ieee80211_self_protected_actioncode ftype;
 421         size_t baselen;
 422         bool deactivated, matches_local = true;
 423         u8 ie_len;
 424         u8 *baseaddr;
 425         __le16 plid, llid, reason;
 426 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
 427         static const char *mplstates[] = {
 428                 [NL80211_PLINK_LISTEN] = "LISTEN",
 429                 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 430                 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 431                 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 432                 [NL80211_PLINK_ESTAB] = "ESTAB",
 433                 [NL80211_PLINK_HOLDING] = "HOLDING",
 434                 [NL80211_PLINK_BLOCKED] = "BLOCKED"
 435         };
 436 #endif
 437
 438         /* need action_code, aux */
 439         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 440                 return;
 441
 442         if (is_multicast_ether_addr(mgmt->da)) {
 443                 mpl_dbg("Mesh plink: ignore frame from multicast address");
 444                 return;
 445         }
 446
 447         baseaddr = mgmt->u.action.u.self_prot.variable;
 448         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 449         if (mgmt->u.action.u.self_prot.action_code ==
 450                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 451                 baseaddr += 4;
 452                 baselen += 4;
 453         }
 454         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 455         if (!elems.peering) {
 456                 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
 457                 return;
 458         }
 459         if (elems.rsn_len &&
 460                         sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 461                 mpl_dbg("Mesh plink: can't establish link with secure peer\n");
 462                 return;
 463         }
 464
 465         ftype = mgmt->u.action.u.self_prot.action_code;
 466         ie_len = elems.peering_len;
 467         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 468             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 469             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 470                                                         && ie_len != 8)) {
 471                 mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
 472                     ftype, ie_len);
 473                 return;
 474         }
 475
 476         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 477                                 (!elems.mesh_id || !elems.mesh_config)) {
 478                 mpl_dbg("Mesh plink: missing necessary ie\n");
 479                 return;
 480         }
 481         /* Note the lines below are correct, the llid in the frame is the plid
 482          * from the point of view of this host.
 483          */
 484         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 485         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 486             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 487                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 488
 489         rcu_read_lock();
 490
 491         sta = sta_info_get(sdata, mgmt->sa);
 492         if (!sta && ftype != WLAN_SP_MESH_PEERING_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 == NL80211_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 != WLAN_SP_MESH_PEERING_CLOSE &&
 512             (!mesh_matches_local(&elems, sdata))) {
 513                 matches_local = false;
 514                 switch (ftype) {
 515                 case WLAN_SP_MESH_PEERING_OPEN:
 516                         event = OPN_RJCT;
 517                         break;
 518                 case WLAN_SP_MESH_PEERING_CONFIRM:
 519                         event = CNF_RJCT;
 520                         break;
 521                 default:
 522                         break;
 523                 }
 524         }
 525
 526         if (!sta && !matches_local) {
 527                 rcu_read_unlock();
 528                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 529                 llid = 0;
 530                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 531                                     mgmt->sa, llid, plid, reason);
 532                 return;
 533         } else if (!sta) {
 534                 /* ftype == WLAN_SP_MESH_PEERING_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 WLAN_SP_MESH_PEERING_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 WLAN_SP_MESH_PEERING_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 WLAN_SP_MESH_PEERING_CLOSE:
 574                         if (sta->plink_state == NL80211_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 NL80211_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 = NL80211_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,
 623                                             WLAN_SP_MESH_PEERING_OPEN,
 624                                             sta->sta.addr, llid, 0, 0);
 625                         mesh_plink_frame_tx(sdata,
 626                                             WLAN_SP_MESH_PEERING_CONFIRM,
 627                                             sta->sta.addr, llid, plid, 0);
 628                         break;
 629                 default:
 630                         spin_unlock_bh(&sta->lock);
 631                         break;
 632                 }
 633                 break;
 634
 635         case NL80211_PLINK_OPN_SNT:
 636                 switch (event) {
 637                 case OPN_RJCT:
 638                 case CNF_RJCT:
 639                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 640                 case CLS_ACPT:
 641                         if (!reason)
 642                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 643                         sta->reason = reason;
 644                         sta->plink_state = NL80211_PLINK_HOLDING;
 645                         if (!mod_plink_timer(sta,
 646                                              dot11MeshHoldingTimeout(sdata)))
 647                                 sta->ignore_plink_timer = true;
 648
 649                         llid = sta->llid;
 650                         spin_unlock_bh(&sta->lock);
 651                         mesh_plink_frame_tx(sdata,
 652                                             WLAN_SP_MESH_PEERING_CLOSE,
 653                                             sta->sta.addr, llid, plid, reason);
 654                         break;
 655                 case OPN_ACPT:
 656                         /* retry timer is left untouched */
 657                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 658                         sta->plid = plid;
 659                         llid = sta->llid;
 660                         spin_unlock_bh(&sta->lock);
 661                         mesh_plink_frame_tx(sdata,
 662                                             WLAN_SP_MESH_PEERING_CONFIRM,
 663                                             sta->sta.addr, llid, plid, 0);
 664                         break;
 665                 case CNF_ACPT:
 666                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 667                         if (!mod_plink_timer(sta,
 668                                              dot11MeshConfirmTimeout(sdata)))
 669                                 sta->ignore_plink_timer = true;
 670
 671                         spin_unlock_bh(&sta->lock);
 672                         break;
 673                 default:
 674                         spin_unlock_bh(&sta->lock);
 675                         break;
 676                 }
 677                 break;
 678
 679         case NL80211_PLINK_OPN_RCVD:
 680                 switch (event) {
 681                 case OPN_RJCT:
 682                 case CNF_RJCT:
 683                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 684                 case CLS_ACPT:
 685                         if (!reason)
 686                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 687                         sta->reason = reason;
 688                         sta->plink_state = NL80211_PLINK_HOLDING;
 689                         if (!mod_plink_timer(sta,
 690                                              dot11MeshHoldingTimeout(sdata)))
 691                                 sta->ignore_plink_timer = true;
 692
 693                         llid = sta->llid;
 694                         spin_unlock_bh(&sta->lock);
 695                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 696                                             sta->sta.addr, llid, plid, reason);
 697                         break;
 698                 case OPN_ACPT:
 699                         llid = sta->llid;
 700                         spin_unlock_bh(&sta->lock);
 701                         mesh_plink_frame_tx(sdata,
 702                                             WLAN_SP_MESH_PEERING_CONFIRM,
 703                                             sta->sta.addr, llid, plid, 0);
 704                         break;
 705                 case CNF_ACPT:
 706                         del_timer(&sta->plink_timer);
 707                         sta->plink_state = NL80211_PLINK_ESTAB;
 708                         spin_unlock_bh(&sta->lock);
 709                         mesh_plink_inc_estab_count(sdata);
 710                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 711                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 712                                 sta->sta.addr);
 713                         break;
 714                 default:
 715                         spin_unlock_bh(&sta->lock);
 716                         break;
 717                 }
 718                 break;
 719
 720         case NL80211_PLINK_CNF_RCVD:
 721                 switch (event) {
 722                 case OPN_RJCT:
 723                 case CNF_RJCT:
 724                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 725                 case CLS_ACPT:
 726                         if (!reason)
 727                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 728                         sta->reason = reason;
 729                         sta->plink_state = NL80211_PLINK_HOLDING;
 730                         if (!mod_plink_timer(sta,
 731                                              dot11MeshHoldingTimeout(sdata)))
 732                                 sta->ignore_plink_timer = true;
 733
 734                         llid = sta->llid;
 735                         spin_unlock_bh(&sta->lock);
 736                         mesh_plink_frame_tx(sdata,
 737                                             WLAN_SP_MESH_PEERING_CLOSE,
 738                                             sta->sta.addr, llid, plid, reason);
 739                         break;
 740                 case OPN_ACPT:
 741                         del_timer(&sta->plink_timer);
 742                         sta->plink_state = NL80211_PLINK_ESTAB;
 743                         spin_unlock_bh(&sta->lock);
 744                         mesh_plink_inc_estab_count(sdata);
 745                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 746                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 747                                 sta->sta.addr);
 748                         mesh_plink_frame_tx(sdata,
 749                                             WLAN_SP_MESH_PEERING_CONFIRM,
 750                                             sta->sta.addr, llid, plid, 0);
 751                         break;
 752                 default:
 753                         spin_unlock_bh(&sta->lock);
 754                         break;
 755                 }
 756                 break;
 757
 758         case NL80211_PLINK_ESTAB:
 759                 switch (event) {
 760                 case CLS_ACPT:
 761                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 762                         sta->reason = reason;
 763                         deactivated = __mesh_plink_deactivate(sta);
 764                         sta->plink_state = NL80211_PLINK_HOLDING;
 765                         llid = sta->llid;
 766                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 767                         spin_unlock_bh(&sta->lock);
 768                         if (deactivated)
 769                                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 770                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 771                                             sta->sta.addr, llid, plid, reason);
 772                         break;
 773                 case OPN_ACPT:
 774                         llid = sta->llid;
 775                         spin_unlock_bh(&sta->lock);
 776                         mesh_plink_frame_tx(sdata,
 777                                             WLAN_SP_MESH_PEERING_CONFIRM,
 778                                             sta->sta.addr, llid, plid, 0);
 779                         break;
 780                 default:
 781                         spin_unlock_bh(&sta->lock);
 782                         break;
 783                 }
 784                 break;
 785         case NL80211_PLINK_HOLDING:
 786                 switch (event) {
 787                 case CLS_ACPT:
 788                         if (del_timer(&sta->plink_timer))
 789                                 sta->ignore_plink_timer = 1;
 790                         mesh_plink_fsm_restart(sta);
 791                         spin_unlock_bh(&sta->lock);
 792                         break;
 793                 case OPN_ACPT:
 794                 case CNF_ACPT:
 795                 case OPN_RJCT:
 796                 case CNF_RJCT:
 797                         llid = sta->llid;
 798                         reason = sta->reason;
 799                         spin_unlock_bh(&sta->lock);
 800                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 801                                             sta->sta.addr, llid, plid, reason);
 802                         break;
 803                 default:
 804                         spin_unlock_bh(&sta->lock);
 805                 }
 806                 break;
 807         default:
 808                 /* should not get here, PLINK_BLOCKED is dealt with at the
 809                  * beginning of the function
 810                  */
 811                 spin_unlock_bh(&sta->lock);
 812                 break;
 813         }
 814
 815         rcu_read_unlock();
 816 }