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 int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
  47                 enum ieee80211_self_protected_actioncode action,
  48                 u8 *da, __le16 llid, __le16 plid, __le16 reason);
  49
  50 static inline
  51 void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
  52 {
  53         atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
  54         mesh_accept_plinks_update(sdata);
  55 }
  56
  57 static inline
  58 void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
  59 {
  60         atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
  61         mesh_accept_plinks_update(sdata);
  62 }
  63
  64 /**
  65  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  66  *
  67  * @sta: mesh peer link to restart
  68  *
  69  * Locking: this function must be called holding sta->lock
  70  */
  71 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  72 {
  73         sta->plink_state = NL80211_PLINK_LISTEN;
  74         sta->llid = sta->plid = sta->reason = 0;
  75         sta->plink_retries = 0;
  76 }
  77
  78 /*
  79  * NOTE: This is just an alias for sta_info_alloc(), see notes
  80  *       on it in the lifecycle management section!
  81  */
  82 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
  83                                          u8 *hw_addr, u32 rates)
  84 {
  85         struct ieee80211_local *local = sdata->local;
  86         struct sta_info *sta;
  87
  88         if (local->num_sta >= MESH_MAX_PLINKS)
  89                 return NULL;
  90
  91         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
  92         if (!sta)
  93                 return NULL;
  94
  95         set_sta_flag(sta, WLAN_STA_AUTH);
  96         set_sta_flag(sta, WLAN_STA_AUTHORIZED);
  97         set_sta_flag(sta, WLAN_STA_WME);
  98         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
  99         rate_control_rate_init(sta);
 100
 101         return sta;
 102 }
 103
 104 /**
 105  * __mesh_plink_deactivate - deactivate mesh peer link
 106  *
 107  * @sta: mesh peer link to deactivate
 108  *
 109  * All mesh paths with this peer as next hop will be flushed
 110  *
 111  * Locking: the caller must hold sta->lock
 112  */
 113 static bool __mesh_plink_deactivate(struct sta_info *sta)
 114 {
 115         struct ieee80211_sub_if_data *sdata = sta->sdata;
 116         bool deactivated = false;
 117
 118         if (sta->plink_state == NL80211_PLINK_ESTAB) {
 119                 mesh_plink_dec_estab_count(sdata);
 120                 deactivated = true;
 121         }
 122         sta->plink_state = NL80211_PLINK_BLOCKED;
 123         mesh_path_flush_by_nexthop(sta);
 124
 125         return deactivated;
 126 }
 127
 128 /**
 129  * mesh_plink_deactivate - deactivate mesh peer link
 130  *
 131  * @sta: mesh peer link to deactivate
 132  *
 133  * All mesh paths with this peer as next hop will be flushed
 134  */
 135 void mesh_plink_deactivate(struct sta_info *sta)
 136 {
 137         struct ieee80211_sub_if_data *sdata = sta->sdata;
 138         bool deactivated;
 139
 140         spin_lock_bh(&sta->lock);
 141         deactivated = __mesh_plink_deactivate(sta);
 142         sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 143         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 144                             sta->sta.addr, sta->llid, sta->plid,
 145                             sta->reason);
 146         spin_unlock_bh(&sta->lock);
 147
 148         if (deactivated)
 149                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 150 }
 151
 152 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 153                 enum ieee80211_self_protected_actioncode action,
 154                 u8 *da, __le16 llid, __le16 plid, __le16 reason) {
 155         struct ieee80211_local *local = sdata->local;
 156         struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400 +
 157                         sdata->u.mesh.ie_len);
 158         struct ieee80211_mgmt *mgmt;
 159         bool include_plid = false;
 160         int ie_len = 4;
 161         u16 peering_proto = 0;
 162         u8 *pos;
 163
 164         if (!skb)
 165                 return -1;
 166         skb_reserve(skb, local->hw.extra_tx_headroom);
 167         /* 25 is the size of the common mgmt part (24) plus the size of the
 168          * common action part (1)
 169          */
 170         mgmt = (struct ieee80211_mgmt *)
 171                 skb_put(skb, 25 + sizeof(mgmt->u.action.u.self_prot));
 172         memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.self_prot));
 173         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 174                                           IEEE80211_STYPE_ACTION);
 175         memcpy(mgmt->da, da, ETH_ALEN);
 176         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 177         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 178         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 179         mgmt->u.action.u.self_prot.action_code = action;
 180
 181         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 182                 /* capability info */
 183                 pos = skb_put(skb, 2);
 184                 memset(pos, 0, 2);
 185                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 186                         /* AID */
 187                         pos = skb_put(skb, 2);
 188                         memcpy(pos + 2, &plid, 2);
 189                 }
 190                 if (ieee80211_add_srates_ie(&sdata->vif, skb) ||
 191                     ieee80211_add_ext_srates_ie(&sdata->vif, skb) ||
 192                     mesh_add_rsn_ie(skb, sdata) ||
 193                     mesh_add_meshid_ie(skb, sdata) ||
 194                     mesh_add_meshconf_ie(skb, sdata))
 195                         return -1;
 196         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 197                 if (mesh_add_meshid_ie(skb, sdata))
 198                         return -1;
 199         }
 200
 201         /* Add Mesh Peering Management element */
 202         switch (action) {
 203         case WLAN_SP_MESH_PEERING_OPEN:
 204                 break;
 205         case WLAN_SP_MESH_PEERING_CONFIRM:
 206                 ie_len += 2;
 207                 include_plid = true;
 208                 break;
 209         case WLAN_SP_MESH_PEERING_CLOSE:
 210                 if (plid) {
 211                         ie_len += 2;
 212                         include_plid = true;
 213                 }
 214                 ie_len += 2;    /* reason code */
 215                 break;
 216         default:
 217                 return -EINVAL;
 218         }
 219
 220         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 221                 return -ENOMEM;
 222
 223         pos = skb_put(skb, 2 + ie_len);
 224         *pos++ = WLAN_EID_PEER_MGMT;
 225         *pos++ = ie_len;
 226         memcpy(pos, &peering_proto, 2);
 227         pos += 2;
 228         memcpy(pos, &llid, 2);
 229         pos += 2;
 230         if (include_plid) {
 231                 memcpy(pos, &plid, 2);
 232                 pos += 2;
 233         }
 234         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 235                 memcpy(pos, &reason, 2);
 236                 pos += 2;
 237         }
 238         if (mesh_add_vendor_ies(skb, sdata))
 239                 return -1;
 240
 241         ieee80211_tx_skb(sdata, skb);
 242         return 0;
 243 }
 244
 245 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 246                 struct ieee80211_sub_if_data *sdata,
 247                 struct ieee802_11_elems *elems)
 248 {
 249         struct ieee80211_local *local = sdata->local;
 250         struct sta_info *sta;
 251
 252         rcu_read_lock();
 253
 254         sta = sta_info_get(sdata, hw_addr);
 255         if (!sta) {
 256                 rcu_read_unlock();
 257                 /* Userspace handles peer allocation when security is enabled
 258                  * */
 259                 if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 260                         cfg80211_notify_new_peer_candidate(sdata->dev, hw_addr,
 261                                         elems->ie_start, elems->total_len,
 262                                         GFP_KERNEL);
 263                 else
 264                         sta = mesh_plink_alloc(sdata, hw_addr, rates);
 265                 if (!sta)
 266                         return;
 267                 if (sta_info_insert_rcu(sta)) {
 268                         rcu_read_unlock();
 269                         return;
 270                 }
 271         }
 272
 273         sta->last_rx = jiffies;
 274         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 275         if (mesh_peer_accepts_plinks(elems) &&
 276                         sta->plink_state == NL80211_PLINK_LISTEN &&
 277                         sdata->u.mesh.accepting_plinks &&
 278                         sdata->u.mesh.mshcfg.auto_open_plinks)
 279                 mesh_plink_open(sta);
 280
 281         rcu_read_unlock();
 282 }
 283
 284 static void mesh_plink_timer(unsigned long data)
 285 {
 286         struct sta_info *sta;
 287         __le16 llid, plid, reason;
 288         struct ieee80211_sub_if_data *sdata;
 289
 290         /*
 291          * This STA is valid because sta_info_destroy() will
 292          * del_timer_sync() this timer after having made sure
 293          * it cannot be readded (by deleting the plink.)
 294          */
 295         sta = (struct sta_info *) data;
 296
 297         if (sta->sdata->local->quiescing) {
 298                 sta->plink_timer_was_running = true;
 299                 return;
 300         }
 301
 302         spin_lock_bh(&sta->lock);
 303         if (sta->ignore_plink_timer) {
 304                 sta->ignore_plink_timer = false;
 305                 spin_unlock_bh(&sta->lock);
 306                 return;
 307         }
 308         mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
 309                 sta->sta.addr, sta->plink_state);
 310         reason = 0;
 311         llid = sta->llid;
 312         plid = sta->plid;
 313         sdata = sta->sdata;
 314
 315         switch (sta->plink_state) {
 316         case NL80211_PLINK_OPN_RCVD:
 317         case NL80211_PLINK_OPN_SNT:
 318                 /* retry timer */
 319                 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
 320                         u32 rand;
 321                         mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
 322                                 sta->sta.addr, sta->plink_retries,
 323                                 sta->plink_timeout);
 324                         get_random_bytes(&rand, sizeof(u32));
 325                         sta->plink_timeout = sta->plink_timeout +
 326                                              rand % sta->plink_timeout;
 327                         ++sta->plink_retries;
 328                         mod_plink_timer(sta, sta->plink_timeout);
 329                         spin_unlock_bh(&sta->lock);
 330                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 331                                             sta->sta.addr, llid, 0, 0);
 332                         break;
 333                 }
 334                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 335                 /* fall through on else */
 336         case NL80211_PLINK_CNF_RCVD:
 337                 /* confirm timer */
 338                 if (!reason)
 339                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 340                 sta->plink_state = NL80211_PLINK_HOLDING;
 341                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 342                 spin_unlock_bh(&sta->lock);
 343                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 344                                     sta->sta.addr, llid, plid, reason);
 345                 break;
 346         case NL80211_PLINK_HOLDING:
 347                 /* holding timer */
 348                 del_timer(&sta->plink_timer);
 349                 mesh_plink_fsm_restart(sta);
 350                 spin_unlock_bh(&sta->lock);
 351                 break;
 352         default:
 353                 spin_unlock_bh(&sta->lock);
 354                 break;
 355         }
 356 }
 357
 358 #ifdef CONFIG_PM
 359 void mesh_plink_quiesce(struct sta_info *sta)
 360 {
 361         if (del_timer_sync(&sta->plink_timer))
 362                 sta->plink_timer_was_running = true;
 363 }
 364
 365 void mesh_plink_restart(struct sta_info *sta)
 366 {
 367         if (sta->plink_timer_was_running) {
 368                 add_timer(&sta->plink_timer);
 369                 sta->plink_timer_was_running = false;
 370         }
 371 }
 372 #endif
 373
 374 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 375 {
 376         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 377         sta->plink_timer.data = (unsigned long) sta;
 378         sta->plink_timer.function = mesh_plink_timer;
 379         sta->plink_timeout = timeout;
 380         add_timer(&sta->plink_timer);
 381 }
 382
 383 int mesh_plink_open(struct sta_info *sta)
 384 {
 385         __le16 llid;
 386         struct ieee80211_sub_if_data *sdata = sta->sdata;
 387
 388         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 389                 return -EPERM;
 390
 391         spin_lock_bh(&sta->lock);
 392         get_random_bytes(&llid, 2);
 393         sta->llid = llid;
 394         if (sta->plink_state != NL80211_PLINK_LISTEN) {
 395                 spin_unlock_bh(&sta->lock);
 396                 return -EBUSY;
 397         }
 398         sta->plink_state = NL80211_PLINK_OPN_SNT;
 399         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 400         spin_unlock_bh(&sta->lock);
 401         mpl_dbg("Mesh plink: starting establishment with %pM\n",
 402                 sta->sta.addr);
 403
 404         return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 405                                    sta->sta.addr, llid, 0, 0);
 406 }
 407
 408 void mesh_plink_block(struct sta_info *sta)
 409 {
 410         struct ieee80211_sub_if_data *sdata = sta->sdata;
 411         bool deactivated;
 412
 413         spin_lock_bh(&sta->lock);
 414         deactivated = __mesh_plink_deactivate(sta);
 415         sta->plink_state = NL80211_PLINK_BLOCKED;
 416         spin_unlock_bh(&sta->lock);
 417
 418         if (deactivated)
 419                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 420 }
 421
 422
 423 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 424                          size_t len, struct ieee80211_rx_status *rx_status)
 425 {
 426         struct ieee80211_local *local = sdata->local;
 427         struct ieee802_11_elems elems;
 428         struct sta_info *sta;
 429         enum plink_event event;
 430         enum ieee80211_self_protected_actioncode ftype;
 431         size_t baselen;
 432         bool deactivated, matches_local = true;
 433         u8 ie_len;
 434         u8 *baseaddr;
 435         __le16 plid, llid, reason;
 436 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
 437         static const char *mplstates[] = {
 438                 [NL80211_PLINK_LISTEN] = "LISTEN",
 439                 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 440                 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 441                 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 442                 [NL80211_PLINK_ESTAB] = "ESTAB",
 443                 [NL80211_PLINK_HOLDING] = "HOLDING",
 444                 [NL80211_PLINK_BLOCKED] = "BLOCKED"
 445         };
 446 #endif
 447
 448         /* need action_code, aux */
 449         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 450                 return;
 451
 452         if (is_multicast_ether_addr(mgmt->da)) {
 453                 mpl_dbg("Mesh plink: ignore frame from multicast address");
 454                 return;
 455         }
 456
 457         baseaddr = mgmt->u.action.u.self_prot.variable;
 458         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 459         if (mgmt->u.action.u.self_prot.action_code ==
 460                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 461                 baseaddr += 4;
 462                 baselen += 4;
 463         }
 464         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 465         if (!elems.peering) {
 466                 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
 467                 return;
 468         }
 469         if (elems.rsn_len &&
 470                         sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 471                 mpl_dbg("Mesh plink: can't establish link with secure peer\n");
 472                 return;
 473         }
 474
 475         ftype = mgmt->u.action.u.self_prot.action_code;
 476         ie_len = elems.peering_len;
 477         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 478             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 479             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 480                                                         && ie_len != 8)) {
 481                 mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
 482                     ftype, ie_len);
 483                 return;
 484         }
 485
 486         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 487                                 (!elems.mesh_id || !elems.mesh_config)) {
 488                 mpl_dbg("Mesh plink: missing necessary ie\n");
 489                 return;
 490         }
 491         /* Note the lines below are correct, the llid in the frame is the plid
 492          * from the point of view of this host.
 493          */
 494         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 495         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 496             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 497                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 498
 499         rcu_read_lock();
 500
 501         sta = sta_info_get(sdata, mgmt->sa);
 502         if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 503                 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
 504                 rcu_read_unlock();
 505                 return;
 506         }
 507
 508         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 509                 mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
 510                 rcu_read_unlock();
 511                 return;
 512         }
 513
 514         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 515                 rcu_read_unlock();
 516                 return;
 517         }
 518
 519         /* Now we will figure out the appropriate event... */
 520         event = PLINK_UNDEFINED;
 521         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 522             (!mesh_matches_local(&elems, sdata))) {
 523                 matches_local = false;
 524                 switch (ftype) {
 525                 case WLAN_SP_MESH_PEERING_OPEN:
 526                         event = OPN_RJCT;
 527                         break;
 528                 case WLAN_SP_MESH_PEERING_CONFIRM:
 529                         event = CNF_RJCT;
 530                         break;
 531                 default:
 532                         break;
 533                 }
 534         }
 535
 536         if (!sta && !matches_local) {
 537                 rcu_read_unlock();
 538                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 539                 llid = 0;
 540                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 541                                     mgmt->sa, llid, plid, reason);
 542                 return;
 543         } else if (!sta) {
 544                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 545                 u32 rates;
 546
 547                 rcu_read_unlock();
 548
 549                 if (!mesh_plink_free_count(sdata)) {
 550                         mpl_dbg("Mesh plink error: no more free plinks\n");
 551                         return;
 552                 }
 553
 554                 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
 555                 sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
 556                 if (!sta) {
 557                         mpl_dbg("Mesh plink error: plink table full\n");
 558                         return;
 559                 }
 560                 if (sta_info_insert_rcu(sta)) {
 561                         rcu_read_unlock();
 562                         return;
 563                 }
 564                 event = OPN_ACPT;
 565                 spin_lock_bh(&sta->lock);
 566         } else if (matches_local) {
 567                 spin_lock_bh(&sta->lock);
 568                 switch (ftype) {
 569                 case WLAN_SP_MESH_PEERING_OPEN:
 570                         if (!mesh_plink_free_count(sdata) ||
 571                             (sta->plid && sta->plid != plid))
 572                                 event = OPN_IGNR;
 573                         else
 574                                 event = OPN_ACPT;
 575                         break;
 576                 case WLAN_SP_MESH_PEERING_CONFIRM:
 577                         if (!mesh_plink_free_count(sdata) ||
 578                             (sta->llid != llid || sta->plid != plid))
 579                                 event = CNF_IGNR;
 580                         else
 581                                 event = CNF_ACPT;
 582                         break;
 583                 case WLAN_SP_MESH_PEERING_CLOSE:
 584                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 585                                 /* Do not check for llid or plid. This does not
 586                                  * follow the standard but since multiple plinks
 587                                  * per sta are not supported, it is necessary in
 588                                  * order to avoid a livelock when MP A sees an
 589                                  * establish peer link to MP B but MP B does not
 590                                  * see it. This can be caused by a timeout in
 591                                  * B's peer link establishment or B beign
 592                                  * restarted.
 593                                  */
 594                                 event = CLS_ACPT;
 595                         else if (sta->plid != plid)
 596                                 event = CLS_IGNR;
 597                         else if (ie_len == 7 && sta->llid != llid)
 598                                 event = CLS_IGNR;
 599                         else
 600                                 event = CLS_ACPT;
 601                         break;
 602                 default:
 603                         mpl_dbg("Mesh plink: unknown frame subtype\n");
 604                         spin_unlock_bh(&sta->lock);
 605                         rcu_read_unlock();
 606                         return;
 607                 }
 608         } else {
 609                 spin_lock_bh(&sta->lock);
 610         }
 611
 612         mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 613                 mgmt->sa, mplstates[sta->plink_state],
 614                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 615                 event);
 616         reason = 0;
 617         switch (sta->plink_state) {
 618                 /* spin_unlock as soon as state is updated at each case */
 619         case NL80211_PLINK_LISTEN:
 620                 switch (event) {
 621                 case CLS_ACPT:
 622                         mesh_plink_fsm_restart(sta);
 623                         spin_unlock_bh(&sta->lock);
 624                         break;
 625                 case OPN_ACPT:
 626                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 627                         sta->plid = plid;
 628                         get_random_bytes(&llid, 2);
 629                         sta->llid = llid;
 630                         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 631                         spin_unlock_bh(&sta->lock);
 632                         mesh_plink_frame_tx(sdata,
 633                                             WLAN_SP_MESH_PEERING_OPEN,
 634                                             sta->sta.addr, llid, 0, 0);
 635                         mesh_plink_frame_tx(sdata,
 636                                             WLAN_SP_MESH_PEERING_CONFIRM,
 637                                             sta->sta.addr, llid, plid, 0);
 638                         break;
 639                 default:
 640                         spin_unlock_bh(&sta->lock);
 641                         break;
 642                 }
 643                 break;
 644
 645         case NL80211_PLINK_OPN_SNT:
 646                 switch (event) {
 647                 case OPN_RJCT:
 648                 case CNF_RJCT:
 649                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 650                 case CLS_ACPT:
 651                         if (!reason)
 652                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 653                         sta->reason = reason;
 654                         sta->plink_state = NL80211_PLINK_HOLDING;
 655                         if (!mod_plink_timer(sta,
 656                                              dot11MeshHoldingTimeout(sdata)))
 657                                 sta->ignore_plink_timer = true;
 658
 659                         llid = sta->llid;
 660                         spin_unlock_bh(&sta->lock);
 661                         mesh_plink_frame_tx(sdata,
 662                                             WLAN_SP_MESH_PEERING_CLOSE,
 663                                             sta->sta.addr, llid, plid, reason);
 664                         break;
 665                 case OPN_ACPT:
 666                         /* retry timer is left untouched */
 667                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 668                         sta->plid = plid;
 669                         llid = sta->llid;
 670                         spin_unlock_bh(&sta->lock);
 671                         mesh_plink_frame_tx(sdata,
 672                                             WLAN_SP_MESH_PEERING_CONFIRM,
 673                                             sta->sta.addr, llid, plid, 0);
 674                         break;
 675                 case CNF_ACPT:
 676                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 677                         if (!mod_plink_timer(sta,
 678                                              dot11MeshConfirmTimeout(sdata)))
 679                                 sta->ignore_plink_timer = true;
 680
 681                         spin_unlock_bh(&sta->lock);
 682                         break;
 683                 default:
 684                         spin_unlock_bh(&sta->lock);
 685                         break;
 686                 }
 687                 break;
 688
 689         case NL80211_PLINK_OPN_RCVD:
 690                 switch (event) {
 691                 case OPN_RJCT:
 692                 case CNF_RJCT:
 693                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 694                 case CLS_ACPT:
 695                         if (!reason)
 696                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 697                         sta->reason = reason;
 698                         sta->plink_state = NL80211_PLINK_HOLDING;
 699                         if (!mod_plink_timer(sta,
 700                                              dot11MeshHoldingTimeout(sdata)))
 701                                 sta->ignore_plink_timer = true;
 702
 703                         llid = sta->llid;
 704                         spin_unlock_bh(&sta->lock);
 705                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 706                                             sta->sta.addr, llid, plid, reason);
 707                         break;
 708                 case OPN_ACPT:
 709                         llid = sta->llid;
 710                         spin_unlock_bh(&sta->lock);
 711                         mesh_plink_frame_tx(sdata,
 712                                             WLAN_SP_MESH_PEERING_CONFIRM,
 713                                             sta->sta.addr, llid, plid, 0);
 714                         break;
 715                 case CNF_ACPT:
 716                         del_timer(&sta->plink_timer);
 717                         sta->plink_state = NL80211_PLINK_ESTAB;
 718                         spin_unlock_bh(&sta->lock);
 719                         mesh_plink_inc_estab_count(sdata);
 720                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 721                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 722                                 sta->sta.addr);
 723                         break;
 724                 default:
 725                         spin_unlock_bh(&sta->lock);
 726                         break;
 727                 }
 728                 break;
 729
 730         case NL80211_PLINK_CNF_RCVD:
 731                 switch (event) {
 732                 case OPN_RJCT:
 733                 case CNF_RJCT:
 734                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 735                 case CLS_ACPT:
 736                         if (!reason)
 737                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 738                         sta->reason = reason;
 739                         sta->plink_state = NL80211_PLINK_HOLDING;
 740                         if (!mod_plink_timer(sta,
 741                                              dot11MeshHoldingTimeout(sdata)))
 742                                 sta->ignore_plink_timer = true;
 743
 744                         llid = sta->llid;
 745                         spin_unlock_bh(&sta->lock);
 746                         mesh_plink_frame_tx(sdata,
 747                                             WLAN_SP_MESH_PEERING_CLOSE,
 748                                             sta->sta.addr, llid, plid, reason);
 749                         break;
 750                 case OPN_ACPT:
 751                         del_timer(&sta->plink_timer);
 752                         sta->plink_state = NL80211_PLINK_ESTAB;
 753                         spin_unlock_bh(&sta->lock);
 754                         mesh_plink_inc_estab_count(sdata);
 755                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 756                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 757                                 sta->sta.addr);
 758                         mesh_plink_frame_tx(sdata,
 759                                             WLAN_SP_MESH_PEERING_CONFIRM,
 760                                             sta->sta.addr, llid, plid, 0);
 761                         break;
 762                 default:
 763                         spin_unlock_bh(&sta->lock);
 764                         break;
 765                 }
 766                 break;
 767
 768         case NL80211_PLINK_ESTAB:
 769                 switch (event) {
 770                 case CLS_ACPT:
 771                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 772                         sta->reason = reason;
 773                         deactivated = __mesh_plink_deactivate(sta);
 774                         sta->plink_state = NL80211_PLINK_HOLDING;
 775                         llid = sta->llid;
 776                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 777                         spin_unlock_bh(&sta->lock);
 778                         if (deactivated)
 779                                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 780                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 781                                             sta->sta.addr, llid, plid, reason);
 782                         break;
 783                 case OPN_ACPT:
 784                         llid = sta->llid;
 785                         spin_unlock_bh(&sta->lock);
 786                         mesh_plink_frame_tx(sdata,
 787                                             WLAN_SP_MESH_PEERING_CONFIRM,
 788                                             sta->sta.addr, llid, plid, 0);
 789                         break;
 790                 default:
 791                         spin_unlock_bh(&sta->lock);
 792                         break;
 793                 }
 794                 break;
 795         case NL80211_PLINK_HOLDING:
 796                 switch (event) {
 797                 case CLS_ACPT:
 798                         if (del_timer(&sta->plink_timer))
 799                                 sta->ignore_plink_timer = 1;
 800                         mesh_plink_fsm_restart(sta);
 801                         spin_unlock_bh(&sta->lock);
 802                         break;
 803                 case OPN_ACPT:
 804                 case CNF_ACPT:
 805                 case OPN_RJCT:
 806                 case CNF_RJCT:
 807                         llid = sta->llid;
 808                         reason = sta->reason;
 809                         spin_unlock_bh(&sta->lock);
 810                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 811                                             sta->sta.addr, llid, plid, reason);
 812                         break;
 813                 default:
 814                         spin_unlock_bh(&sta->lock);
 815                 }
 816                 break;
 817         default:
 818                 /* should not get here, PLINK_BLOCKED is dealt with at the
 819                  * beginning of the function
 820                  */
 821                 spin_unlock_bh(&sta->lock);
 822                 break;
 823         }
 824
 825         rcu_read_unlock();
 826 }