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 #define sta_meets_rssi_threshold(sta, sdata) \
  35                 (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
  36                 (s8) -ewma_read(&sta->avg_signal) > \
  37                 sdata->u.mesh.mshcfg.rssi_threshold)
  38
  39 enum plink_event {
  40         PLINK_UNDEFINED,
  41         OPN_ACPT,
  42         OPN_RJCT,
  43         OPN_IGNR,
  44         CNF_ACPT,
  45         CNF_RJCT,
  46         CNF_IGNR,
  47         CLS_ACPT,
  48         CLS_IGNR
  49 };
  50
  51 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
  52                 enum ieee80211_self_protected_actioncode action,
  53                 u8 *da, __le16 llid, __le16 plid, __le16 reason);
  54
  55 static inline
  56 void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
  57 {
  58         atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
  59         mesh_accept_plinks_update(sdata);
  60 }
  61
  62 static inline
  63 void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
  64 {
  65         atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
  66         mesh_accept_plinks_update(sdata);
  67 }
  68
  69 /**
  70  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  71  *
  72  * @sta: mesh peer link to restart
  73  *
  74  * Locking: this function must be called holding sta->lock
  75  */
  76 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  77 {
  78         sta->plink_state = NL80211_PLINK_LISTEN;
  79         sta->llid = sta->plid = sta->reason = 0;
  80         sta->plink_retries = 0;
  81 }
  82
  83 /*
  84  * NOTE: This is just an alias for sta_info_alloc(), see notes
  85  *       on it in the lifecycle management section!
  86  */
  87 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
  88                                          u8 *hw_addr, u32 rates,
  89                                          struct ieee802_11_elems *elems)
  90 {
  91         struct ieee80211_local *local = sdata->local;
  92         struct ieee80211_supported_band *sband;
  93         struct sta_info *sta;
  94
  95         sband = local->hw.wiphy->bands[local->oper_channel->band];
  96
  97         if (local->num_sta >= MESH_MAX_PLINKS)
  98                 return NULL;
  99
 100         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 101         if (!sta)
 102                 return NULL;
 103
 104         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 105         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 106         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 107
 108         set_sta_flag(sta, WLAN_STA_WME);
 109
 110         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 111         if (elems->ht_cap_elem)
 112                 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 113                                                   elems->ht_cap_elem,
 114                                                   &sta->sta.ht_cap);
 115         rate_control_rate_init(sta);
 116
 117         return sta;
 118 }
 119
 120 /**
 121  * __mesh_plink_deactivate - deactivate mesh peer link
 122  *
 123  * @sta: mesh peer link to deactivate
 124  *
 125  * All mesh paths with this peer as next hop will be flushed
 126  *
 127  * Locking: the caller must hold sta->lock
 128  */
 129 static bool __mesh_plink_deactivate(struct sta_info *sta)
 130 {
 131         struct ieee80211_sub_if_data *sdata = sta->sdata;
 132         bool deactivated = false;
 133
 134         if (sta->plink_state == NL80211_PLINK_ESTAB) {
 135                 mesh_plink_dec_estab_count(sdata);
 136                 deactivated = true;
 137         }
 138         sta->plink_state = NL80211_PLINK_BLOCKED;
 139         mesh_path_flush_by_nexthop(sta);
 140
 141         return deactivated;
 142 }
 143
 144 /**
 145  * mesh_plink_deactivate - deactivate mesh peer link
 146  *
 147  * @sta: mesh peer link to deactivate
 148  *
 149  * All mesh paths with this peer as next hop will be flushed
 150  */
 151 void mesh_plink_deactivate(struct sta_info *sta)
 152 {
 153         struct ieee80211_sub_if_data *sdata = sta->sdata;
 154         bool deactivated;
 155
 156         spin_lock_bh(&sta->lock);
 157         deactivated = __mesh_plink_deactivate(sta);
 158         sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 159         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 160                             sta->sta.addr, sta->llid, sta->plid,
 161                             sta->reason);
 162         spin_unlock_bh(&sta->lock);
 163
 164         if (deactivated)
 165                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 166 }
 167
 168 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 169                 enum ieee80211_self_protected_actioncode action,
 170                 u8 *da, __le16 llid, __le16 plid, __le16 reason) {
 171         struct ieee80211_local *local = sdata->local;
 172         struct sk_buff *skb;
 173         struct ieee80211_mgmt *mgmt;
 174         bool include_plid = false;
 175         u16 peering_proto = 0;
 176         u8 *pos, ie_len = 4;
 177         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 178                       sizeof(mgmt->u.action.u.self_prot);
 179
 180         skb = dev_alloc_skb(local->tx_headroom +
 181                             hdr_len +
 182                             2 + /* capability info */
 183                             2 + /* AID */
 184                             2 + 8 + /* supported rates */
 185                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 186                             2 + sdata->u.mesh.mesh_id_len +
 187                             2 + sizeof(struct ieee80211_meshconf_ie) +
 188                             2 + sizeof(struct ieee80211_ht_cap) +
 189                             2 + sizeof(struct ieee80211_ht_info) +
 190                             2 + 8 + /* peering IE */
 191                             sdata->u.mesh.ie_len);
 192         if (!skb)
 193                 return -1;
 194         skb_reserve(skb, local->tx_headroom);
 195         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 196         memset(mgmt, 0, hdr_len);
 197         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 198                                           IEEE80211_STYPE_ACTION);
 199         memcpy(mgmt->da, da, ETH_ALEN);
 200         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 201         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 202         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 203         mgmt->u.action.u.self_prot.action_code = action;
 204
 205         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 206                 /* capability info */
 207                 pos = skb_put(skb, 2);
 208                 memset(pos, 0, 2);
 209                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 210                         /* AID */
 211                         pos = skb_put(skb, 2);
 212                         memcpy(pos + 2, &plid, 2);
 213                 }
 214                 if (ieee80211_add_srates_ie(&sdata->vif, skb) ||
 215                     ieee80211_add_ext_srates_ie(&sdata->vif, skb) ||
 216                     mesh_add_rsn_ie(skb, sdata) ||
 217                     mesh_add_meshid_ie(skb, sdata) ||
 218                     mesh_add_meshconf_ie(skb, sdata))
 219                         return -1;
 220         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 221                 if (mesh_add_meshid_ie(skb, sdata))
 222                         return -1;
 223         }
 224
 225         /* Add Mesh Peering Management element */
 226         switch (action) {
 227         case WLAN_SP_MESH_PEERING_OPEN:
 228                 break;
 229         case WLAN_SP_MESH_PEERING_CONFIRM:
 230                 ie_len += 2;
 231                 include_plid = true;
 232                 break;
 233         case WLAN_SP_MESH_PEERING_CLOSE:
 234                 if (plid) {
 235                         ie_len += 2;
 236                         include_plid = true;
 237                 }
 238                 ie_len += 2;    /* reason code */
 239                 break;
 240         default:
 241                 return -EINVAL;
 242         }
 243
 244         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 245                 return -ENOMEM;
 246
 247         pos = skb_put(skb, 2 + ie_len);
 248         *pos++ = WLAN_EID_PEER_MGMT;
 249         *pos++ = ie_len;
 250         memcpy(pos, &peering_proto, 2);
 251         pos += 2;
 252         memcpy(pos, &llid, 2);
 253         pos += 2;
 254         if (include_plid) {
 255                 memcpy(pos, &plid, 2);
 256                 pos += 2;
 257         }
 258         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 259                 memcpy(pos, &reason, 2);
 260                 pos += 2;
 261         }
 262
 263         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 264                 if (mesh_add_ht_cap_ie(skb, sdata) ||
 265                     mesh_add_ht_info_ie(skb, sdata))
 266                         return -1;
 267         }
 268
 269         if (mesh_add_vendor_ies(skb, sdata))
 270                 return -1;
 271
 272         ieee80211_tx_skb(sdata, skb);
 273         return 0;
 274 }
 275
 276 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 277                 struct ieee80211_sub_if_data *sdata,
 278                 struct ieee802_11_elems *elems)
 279 {
 280         struct ieee80211_local *local = sdata->local;
 281         struct sta_info *sta;
 282
 283         rcu_read_lock();
 284
 285         sta = sta_info_get(sdata, hw_addr);
 286         if (!sta) {
 287                 rcu_read_unlock();
 288                 /* Userspace handles peer allocation when security is enabled
 289                  * */
 290                 if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 291                         cfg80211_notify_new_peer_candidate(sdata->dev, hw_addr,
 292                                         elems->ie_start, elems->total_len,
 293                                         GFP_KERNEL);
 294                 else
 295                         sta = mesh_plink_alloc(sdata, hw_addr, rates, elems);
 296                 if (!sta)
 297                         return;
 298                 if (sta_info_insert_rcu(sta)) {
 299                         rcu_read_unlock();
 300                         return;
 301                 }
 302         }
 303
 304         sta->last_rx = jiffies;
 305         sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 306         if (mesh_peer_accepts_plinks(elems) &&
 307                         sta->plink_state == NL80211_PLINK_LISTEN &&
 308                         sdata->u.mesh.accepting_plinks &&
 309                         sdata->u.mesh.mshcfg.auto_open_plinks &&
 310                         sta_meets_rssi_threshold(sta, sdata))
 311                 mesh_plink_open(sta);
 312
 313         rcu_read_unlock();
 314 }
 315
 316 static void mesh_plink_timer(unsigned long data)
 317 {
 318         struct sta_info *sta;
 319         __le16 llid, plid, reason;
 320         struct ieee80211_sub_if_data *sdata;
 321
 322         /*
 323          * This STA is valid because sta_info_destroy() will
 324          * del_timer_sync() this timer after having made sure
 325          * it cannot be readded (by deleting the plink.)
 326          */
 327         sta = (struct sta_info *) data;
 328
 329         if (sta->sdata->local->quiescing) {
 330                 sta->plink_timer_was_running = true;
 331                 return;
 332         }
 333
 334         spin_lock_bh(&sta->lock);
 335         if (sta->ignore_plink_timer) {
 336                 sta->ignore_plink_timer = false;
 337                 spin_unlock_bh(&sta->lock);
 338                 return;
 339         }
 340         mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
 341                 sta->sta.addr, sta->plink_state);
 342         reason = 0;
 343         llid = sta->llid;
 344         plid = sta->plid;
 345         sdata = sta->sdata;
 346
 347         switch (sta->plink_state) {
 348         case NL80211_PLINK_OPN_RCVD:
 349         case NL80211_PLINK_OPN_SNT:
 350                 /* retry timer */
 351                 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
 352                         u32 rand;
 353                         mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
 354                                 sta->sta.addr, sta->plink_retries,
 355                                 sta->plink_timeout);
 356                         get_random_bytes(&rand, sizeof(u32));
 357                         sta->plink_timeout = sta->plink_timeout +
 358                                              rand % sta->plink_timeout;
 359                         ++sta->plink_retries;
 360                         mod_plink_timer(sta, sta->plink_timeout);
 361                         spin_unlock_bh(&sta->lock);
 362                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 363                                             sta->sta.addr, llid, 0, 0);
 364                         break;
 365                 }
 366                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 367                 /* fall through on else */
 368         case NL80211_PLINK_CNF_RCVD:
 369                 /* confirm timer */
 370                 if (!reason)
 371                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 372                 sta->plink_state = NL80211_PLINK_HOLDING;
 373                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 374                 spin_unlock_bh(&sta->lock);
 375                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 376                                     sta->sta.addr, llid, plid, reason);
 377                 break;
 378         case NL80211_PLINK_HOLDING:
 379                 /* holding timer */
 380                 del_timer(&sta->plink_timer);
 381                 mesh_plink_fsm_restart(sta);
 382                 spin_unlock_bh(&sta->lock);
 383                 break;
 384         default:
 385                 spin_unlock_bh(&sta->lock);
 386                 break;
 387         }
 388 }
 389
 390 #ifdef CONFIG_PM
 391 void mesh_plink_quiesce(struct sta_info *sta)
 392 {
 393         if (del_timer_sync(&sta->plink_timer))
 394                 sta->plink_timer_was_running = true;
 395 }
 396
 397 void mesh_plink_restart(struct sta_info *sta)
 398 {
 399         if (sta->plink_timer_was_running) {
 400                 add_timer(&sta->plink_timer);
 401                 sta->plink_timer_was_running = false;
 402         }
 403 }
 404 #endif
 405
 406 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 407 {
 408         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 409         sta->plink_timer.data = (unsigned long) sta;
 410         sta->plink_timer.function = mesh_plink_timer;
 411         sta->plink_timeout = timeout;
 412         add_timer(&sta->plink_timer);
 413 }
 414
 415 int mesh_plink_open(struct sta_info *sta)
 416 {
 417         __le16 llid;
 418         struct ieee80211_sub_if_data *sdata = sta->sdata;
 419
 420         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 421                 return -EPERM;
 422
 423         spin_lock_bh(&sta->lock);
 424         get_random_bytes(&llid, 2);
 425         sta->llid = llid;
 426         if (sta->plink_state != NL80211_PLINK_LISTEN) {
 427                 spin_unlock_bh(&sta->lock);
 428                 return -EBUSY;
 429         }
 430         sta->plink_state = NL80211_PLINK_OPN_SNT;
 431         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 432         spin_unlock_bh(&sta->lock);
 433         mpl_dbg("Mesh plink: starting establishment with %pM\n",
 434                 sta->sta.addr);
 435
 436         return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 437                                    sta->sta.addr, llid, 0, 0);
 438 }
 439
 440 void mesh_plink_block(struct sta_info *sta)
 441 {
 442         struct ieee80211_sub_if_data *sdata = sta->sdata;
 443         bool deactivated;
 444
 445         spin_lock_bh(&sta->lock);
 446         deactivated = __mesh_plink_deactivate(sta);
 447         sta->plink_state = NL80211_PLINK_BLOCKED;
 448         spin_unlock_bh(&sta->lock);
 449
 450         if (deactivated)
 451                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 452 }
 453
 454
 455 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 456                          size_t len, struct ieee80211_rx_status *rx_status)
 457 {
 458         struct ieee80211_local *local = sdata->local;
 459         struct ieee802_11_elems elems;
 460         struct sta_info *sta;
 461         enum plink_event event;
 462         enum ieee80211_self_protected_actioncode ftype;
 463         size_t baselen;
 464         bool deactivated, matches_local = true;
 465         u8 ie_len;
 466         u8 *baseaddr;
 467         __le16 plid, llid, reason;
 468 #ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
 469         static const char *mplstates[] = {
 470                 [NL80211_PLINK_LISTEN] = "LISTEN",
 471                 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 472                 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 473                 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 474                 [NL80211_PLINK_ESTAB] = "ESTAB",
 475                 [NL80211_PLINK_HOLDING] = "HOLDING",
 476                 [NL80211_PLINK_BLOCKED] = "BLOCKED"
 477         };
 478 #endif
 479
 480         /* need action_code, aux */
 481         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 482                 return;
 483
 484         if (is_multicast_ether_addr(mgmt->da)) {
 485                 mpl_dbg("Mesh plink: ignore frame from multicast address");
 486                 return;
 487         }
 488
 489         baseaddr = mgmt->u.action.u.self_prot.variable;
 490         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 491         if (mgmt->u.action.u.self_prot.action_code ==
 492                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 493                 baseaddr += 4;
 494                 baselen += 4;
 495         }
 496         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 497         if (!elems.peering) {
 498                 mpl_dbg("Mesh plink: missing necessary peer link ie\n");
 499                 return;
 500         }
 501         if (elems.rsn_len &&
 502                         sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 503                 mpl_dbg("Mesh plink: can't establish link with secure peer\n");
 504                 return;
 505         }
 506
 507         ftype = mgmt->u.action.u.self_prot.action_code;
 508         ie_len = elems.peering_len;
 509         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 510             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 511             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 512                                                         && ie_len != 8)) {
 513                 mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
 514                     ftype, ie_len);
 515                 return;
 516         }
 517
 518         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 519                                 (!elems.mesh_id || !elems.mesh_config)) {
 520                 mpl_dbg("Mesh plink: missing necessary ie\n");
 521                 return;
 522         }
 523         /* Note the lines below are correct, the llid in the frame is the plid
 524          * from the point of view of this host.
 525          */
 526         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 527         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 528             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 529                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 530
 531         rcu_read_lock();
 532
 533         sta = sta_info_get(sdata, mgmt->sa);
 534         if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 535                 mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
 536                 rcu_read_unlock();
 537                 return;
 538         }
 539
 540         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 541             !sta_meets_rssi_threshold(sta, sdata)) {
 542                 mpl_dbg("Mesh plink: %pM does not meet rssi threshold\n",
 543                         sta->sta.addr);
 544                 rcu_read_unlock();
 545                 return;
 546         }
 547
 548         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 549                 mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
 550                 rcu_read_unlock();
 551                 return;
 552         }
 553
 554         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 555                 rcu_read_unlock();
 556                 return;
 557         }
 558
 559         /* Now we will figure out the appropriate event... */
 560         event = PLINK_UNDEFINED;
 561         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 562             (!mesh_matches_local(&elems, sdata))) {
 563                 matches_local = false;
 564                 switch (ftype) {
 565                 case WLAN_SP_MESH_PEERING_OPEN:
 566                         event = OPN_RJCT;
 567                         break;
 568                 case WLAN_SP_MESH_PEERING_CONFIRM:
 569                         event = CNF_RJCT;
 570                         break;
 571                 default:
 572                         break;
 573                 }
 574         }
 575
 576         if (!sta && !matches_local) {
 577                 rcu_read_unlock();
 578                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 579                 llid = 0;
 580                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 581                                     mgmt->sa, llid, plid, reason);
 582                 return;
 583         } else if (!sta) {
 584                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 585                 u32 rates;
 586
 587                 rcu_read_unlock();
 588
 589                 if (!mesh_plink_free_count(sdata)) {
 590                         mpl_dbg("Mesh plink error: no more free plinks\n");
 591                         return;
 592                 }
 593
 594                 rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
 595                 sta = mesh_plink_alloc(sdata, mgmt->sa, rates, &elems);
 596                 if (!sta) {
 597                         mpl_dbg("Mesh plink error: plink table full\n");
 598                         return;
 599                 }
 600                 if (sta_info_insert_rcu(sta)) {
 601                         rcu_read_unlock();
 602                         return;
 603                 }
 604                 event = OPN_ACPT;
 605                 spin_lock_bh(&sta->lock);
 606         } else if (matches_local) {
 607                 spin_lock_bh(&sta->lock);
 608                 switch (ftype) {
 609                 case WLAN_SP_MESH_PEERING_OPEN:
 610                         if (!mesh_plink_free_count(sdata) ||
 611                             (sta->plid && sta->plid != plid))
 612                                 event = OPN_IGNR;
 613                         else
 614                                 event = OPN_ACPT;
 615                         break;
 616                 case WLAN_SP_MESH_PEERING_CONFIRM:
 617                         if (!mesh_plink_free_count(sdata) ||
 618                             (sta->llid != llid || sta->plid != plid))
 619                                 event = CNF_IGNR;
 620                         else
 621                                 event = CNF_ACPT;
 622                         break;
 623                 case WLAN_SP_MESH_PEERING_CLOSE:
 624                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 625                                 /* Do not check for llid or plid. This does not
 626                                  * follow the standard but since multiple plinks
 627                                  * per sta are not supported, it is necessary in
 628                                  * order to avoid a livelock when MP A sees an
 629                                  * establish peer link to MP B but MP B does not
 630                                  * see it. This can be caused by a timeout in
 631                                  * B's peer link establishment or B beign
 632                                  * restarted.
 633                                  */
 634                                 event = CLS_ACPT;
 635                         else if (sta->plid != plid)
 636                                 event = CLS_IGNR;
 637                         else if (ie_len == 7 && sta->llid != llid)
 638                                 event = CLS_IGNR;
 639                         else
 640                                 event = CLS_ACPT;
 641                         break;
 642                 default:
 643                         mpl_dbg("Mesh plink: unknown frame subtype\n");
 644                         spin_unlock_bh(&sta->lock);
 645                         rcu_read_unlock();
 646                         return;
 647                 }
 648         } else {
 649                 spin_lock_bh(&sta->lock);
 650         }
 651
 652         mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 653                 mgmt->sa, mplstates[sta->plink_state],
 654                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 655                 event);
 656         reason = 0;
 657         switch (sta->plink_state) {
 658                 /* spin_unlock as soon as state is updated at each case */
 659         case NL80211_PLINK_LISTEN:
 660                 switch (event) {
 661                 case CLS_ACPT:
 662                         mesh_plink_fsm_restart(sta);
 663                         spin_unlock_bh(&sta->lock);
 664                         break;
 665                 case OPN_ACPT:
 666                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 667                         sta->plid = plid;
 668                         get_random_bytes(&llid, 2);
 669                         sta->llid = llid;
 670                         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 671                         spin_unlock_bh(&sta->lock);
 672                         mesh_plink_frame_tx(sdata,
 673                                             WLAN_SP_MESH_PEERING_OPEN,
 674                                             sta->sta.addr, llid, 0, 0);
 675                         mesh_plink_frame_tx(sdata,
 676                                             WLAN_SP_MESH_PEERING_CONFIRM,
 677                                             sta->sta.addr, llid, plid, 0);
 678                         break;
 679                 default:
 680                         spin_unlock_bh(&sta->lock);
 681                         break;
 682                 }
 683                 break;
 684
 685         case NL80211_PLINK_OPN_SNT:
 686                 switch (event) {
 687                 case OPN_RJCT:
 688                 case CNF_RJCT:
 689                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 690                 case CLS_ACPT:
 691                         if (!reason)
 692                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 693                         sta->reason = reason;
 694                         sta->plink_state = NL80211_PLINK_HOLDING;
 695                         if (!mod_plink_timer(sta,
 696                                              dot11MeshHoldingTimeout(sdata)))
 697                                 sta->ignore_plink_timer = true;
 698
 699                         llid = sta->llid;
 700                         spin_unlock_bh(&sta->lock);
 701                         mesh_plink_frame_tx(sdata,
 702                                             WLAN_SP_MESH_PEERING_CLOSE,
 703                                             sta->sta.addr, llid, plid, reason);
 704                         break;
 705                 case OPN_ACPT:
 706                         /* retry timer is left untouched */
 707                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 708                         sta->plid = plid;
 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                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 717                         if (!mod_plink_timer(sta,
 718                                              dot11MeshConfirmTimeout(sdata)))
 719                                 sta->ignore_plink_timer = true;
 720
 721                         spin_unlock_bh(&sta->lock);
 722                         break;
 723                 default:
 724                         spin_unlock_bh(&sta->lock);
 725                         break;
 726                 }
 727                 break;
 728
 729         case NL80211_PLINK_OPN_RCVD:
 730                 switch (event) {
 731                 case OPN_RJCT:
 732                 case CNF_RJCT:
 733                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 734                 case CLS_ACPT:
 735                         if (!reason)
 736                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 737                         sta->reason = reason;
 738                         sta->plink_state = NL80211_PLINK_HOLDING;
 739                         if (!mod_plink_timer(sta,
 740                                              dot11MeshHoldingTimeout(sdata)))
 741                                 sta->ignore_plink_timer = true;
 742
 743                         llid = sta->llid;
 744                         spin_unlock_bh(&sta->lock);
 745                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 746                                             sta->sta.addr, llid, plid, reason);
 747                         break;
 748                 case OPN_ACPT:
 749                         llid = sta->llid;
 750                         spin_unlock_bh(&sta->lock);
 751                         mesh_plink_frame_tx(sdata,
 752                                             WLAN_SP_MESH_PEERING_CONFIRM,
 753                                             sta->sta.addr, llid, plid, 0);
 754                         break;
 755                 case CNF_ACPT:
 756                         del_timer(&sta->plink_timer);
 757                         sta->plink_state = NL80211_PLINK_ESTAB;
 758                         spin_unlock_bh(&sta->lock);
 759                         mesh_plink_inc_estab_count(sdata);
 760                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 761                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 762                                 sta->sta.addr);
 763                         break;
 764                 default:
 765                         spin_unlock_bh(&sta->lock);
 766                         break;
 767                 }
 768                 break;
 769
 770         case NL80211_PLINK_CNF_RCVD:
 771                 switch (event) {
 772                 case OPN_RJCT:
 773                 case CNF_RJCT:
 774                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 775                 case CLS_ACPT:
 776                         if (!reason)
 777                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 778                         sta->reason = reason;
 779                         sta->plink_state = NL80211_PLINK_HOLDING;
 780                         if (!mod_plink_timer(sta,
 781                                              dot11MeshHoldingTimeout(sdata)))
 782                                 sta->ignore_plink_timer = true;
 783
 784                         llid = sta->llid;
 785                         spin_unlock_bh(&sta->lock);
 786                         mesh_plink_frame_tx(sdata,
 787                                             WLAN_SP_MESH_PEERING_CLOSE,
 788                                             sta->sta.addr, llid, plid, reason);
 789                         break;
 790                 case OPN_ACPT:
 791                         del_timer(&sta->plink_timer);
 792                         sta->plink_state = NL80211_PLINK_ESTAB;
 793                         spin_unlock_bh(&sta->lock);
 794                         mesh_plink_inc_estab_count(sdata);
 795                         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 796                         mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
 797                                 sta->sta.addr);
 798                         mesh_plink_frame_tx(sdata,
 799                                             WLAN_SP_MESH_PEERING_CONFIRM,
 800                                             sta->sta.addr, llid, plid, 0);
 801                         break;
 802                 default:
 803                         spin_unlock_bh(&sta->lock);
 804                         break;
 805                 }
 806                 break;
 807
 808         case NL80211_PLINK_ESTAB:
 809                 switch (event) {
 810                 case CLS_ACPT:
 811                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 812                         sta->reason = reason;
 813                         deactivated = __mesh_plink_deactivate(sta);
 814                         sta->plink_state = NL80211_PLINK_HOLDING;
 815                         llid = sta->llid;
 816                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 817                         spin_unlock_bh(&sta->lock);
 818                         if (deactivated)
 819                                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 820                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 821                                             sta->sta.addr, llid, plid, reason);
 822                         break;
 823                 case OPN_ACPT:
 824                         llid = sta->llid;
 825                         spin_unlock_bh(&sta->lock);
 826                         mesh_plink_frame_tx(sdata,
 827                                             WLAN_SP_MESH_PEERING_CONFIRM,
 828                                             sta->sta.addr, llid, plid, 0);
 829                         break;
 830                 default:
 831                         spin_unlock_bh(&sta->lock);
 832                         break;
 833                 }
 834                 break;
 835         case NL80211_PLINK_HOLDING:
 836                 switch (event) {
 837                 case CLS_ACPT:
 838                         if (del_timer(&sta->plink_timer))
 839                                 sta->ignore_plink_timer = 1;
 840                         mesh_plink_fsm_restart(sta);
 841                         spin_unlock_bh(&sta->lock);
 842                         break;
 843                 case OPN_ACPT:
 844                 case CNF_ACPT:
 845                 case OPN_RJCT:
 846                 case CNF_RJCT:
 847                         llid = sta->llid;
 848                         reason = sta->reason;
 849                         spin_unlock_bh(&sta->lock);
 850                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 851                                             sta->sta.addr, llid, plid, reason);
 852                         break;
 853                 default:
 854                         spin_unlock_bh(&sta->lock);
 855                 }
 856                 break;
 857         default:
 858                 /* should not get here, PLINK_BLOCKED is dealt with at the
 859                  * beginning of the function
 860                  */
 861                 spin_unlock_bh(&sta->lock);
 862                 break;
 863         }
 864
 865         rcu_read_unlock();
 866 }