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 #define PLINK_GET_LLID(p) (p + 2)
  17 #define PLINK_GET_PLID(p) (p + 4)
  18
  19 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
  20                                 jiffies + HZ * t / 1000))
  21
  22 #define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
  23 #define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
  24 #define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
  25 #define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
  26 #define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
  27
  28 /* We only need a valid sta if user configured a minimum rssi_threshold. */
  29 #define rssi_threshold_check(sta, sdata) \
  30                 (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
  31                 (sta && (s8) -ewma_read(&sta->avg_signal) > \
  32                 sdata->u.mesh.mshcfg.rssi_threshold))
  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 u32 mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
  52 {
  53         atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
  54         return mesh_accept_plinks_update(sdata);
  55 }
  56
  57 static inline
  58 u32 mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
  59 {
  60         atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
  61         return 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  * Allocate mesh sta entry and insert into station table
  80  */
  81 static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
  82                                          u8 *hw_addr)
  83 {
  84         struct sta_info *sta;
  85
  86         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
  87                 return NULL;
  88
  89         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
  90         if (!sta)
  91                 return NULL;
  92
  93         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
  94         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
  95         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
  96
  97         set_sta_flag(sta, WLAN_STA_WME);
  98
  99         return sta;
 100 }
 101
 102 /**
 103  * mesh_set_ht_prot_mode - set correct HT protection mode
 104  *
 105  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 106  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 107  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 108  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 109  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 110  * HT20 peer is present. Otherwise no-protection mode is selected.
 111  */
 112 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 113 {
 114         struct ieee80211_local *local = sdata->local;
 115         struct sta_info *sta;
 116         u32 changed = 0;
 117         u16 ht_opmode;
 118         bool non_ht_sta = false, ht20_sta = false;
 119
 120         if (sdata->vif.bss_conf.channel_type == NL80211_CHAN_NO_HT)
 121                 return 0;
 122
 123         rcu_read_lock();
 124         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 125                 if (sdata != sta->sdata ||
 126                     sta->plink_state != NL80211_PLINK_ESTAB)
 127                         continue;
 128
 129                 switch (sta->ch_type) {
 130                 case NL80211_CHAN_NO_HT:
 131                         mpl_dbg(sdata,
 132                                 "mesh_plink %pM: nonHT sta (%pM) is present\n",
 133                                 sdata->vif.addr, sta->sta.addr);
 134                         non_ht_sta = true;
 135                         goto out;
 136                 case NL80211_CHAN_HT20:
 137                         mpl_dbg(sdata,
 138                                 "mesh_plink %pM: HT20 sta (%pM) is present\n",
 139                                 sdata->vif.addr, sta->sta.addr);
 140                         ht20_sta = true;
 141                 default:
 142                         break;
 143                 }
 144         }
 145 out:
 146         rcu_read_unlock();
 147
 148         if (non_ht_sta)
 149                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 150         else if (ht20_sta &&
 151                  sdata->vif.bss_conf.channel_type > NL80211_CHAN_HT20)
 152                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 153         else
 154                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 155
 156         if (sdata->vif.bss_conf.ht_operation_mode != ht_opmode) {
 157                 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 158                 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 159                 changed = BSS_CHANGED_HT;
 160                 mpl_dbg(sdata,
 161                         "mesh_plink %pM: protection mode changed to %d\n",
 162                         sdata->vif.addr, ht_opmode);
 163         }
 164
 165         return changed;
 166 }
 167
 168 /**
 169  * __mesh_plink_deactivate - deactivate mesh peer link
 170  *
 171  * @sta: mesh peer link to deactivate
 172  *
 173  * All mesh paths with this peer as next hop will be flushed
 174  * Returns beacon changed flag if the beacon content changed.
 175  *
 176  * Locking: the caller must hold sta->lock
 177  */
 178 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 179 {
 180         struct ieee80211_sub_if_data *sdata = sta->sdata;
 181         u32 changed = 0;
 182
 183         if (sta->plink_state == NL80211_PLINK_ESTAB)
 184                 changed = mesh_plink_dec_estab_count(sdata);
 185         sta->plink_state = NL80211_PLINK_BLOCKED;
 186         mesh_path_flush_by_nexthop(sta);
 187
 188         return changed;
 189 }
 190
 191 /**
 192  * mesh_plink_deactivate - deactivate mesh peer link
 193  *
 194  * @sta: mesh peer link to deactivate
 195  *
 196  * All mesh paths with this peer as next hop will be flushed
 197  */
 198 void mesh_plink_deactivate(struct sta_info *sta)
 199 {
 200         struct ieee80211_sub_if_data *sdata = sta->sdata;
 201         u32 changed;
 202
 203         spin_lock_bh(&sta->lock);
 204         changed = __mesh_plink_deactivate(sta);
 205         sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 206         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 207                             sta->sta.addr, sta->llid, sta->plid,
 208                             sta->reason);
 209         spin_unlock_bh(&sta->lock);
 210
 211         ieee80211_bss_info_change_notify(sdata, changed);
 212 }
 213
 214 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 215                 enum ieee80211_self_protected_actioncode action,
 216                 u8 *da, __le16 llid, __le16 plid, __le16 reason) {
 217         struct ieee80211_local *local = sdata->local;
 218         struct sk_buff *skb;
 219         struct ieee80211_tx_info *info;
 220         struct ieee80211_mgmt *mgmt;
 221         bool include_plid = false;
 222         u16 peering_proto = 0;
 223         u8 *pos, ie_len = 4;
 224         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 225                       sizeof(mgmt->u.action.u.self_prot);
 226         int err = -ENOMEM;
 227
 228         skb = dev_alloc_skb(local->tx_headroom +
 229                             hdr_len +
 230                             2 + /* capability info */
 231                             2 + /* AID */
 232                             2 + 8 + /* supported rates */
 233                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 234                             2 + sdata->u.mesh.mesh_id_len +
 235                             2 + sizeof(struct ieee80211_meshconf_ie) +
 236                             2 + sizeof(struct ieee80211_ht_cap) +
 237                             2 + sizeof(struct ieee80211_ht_operation) +
 238                             2 + 8 + /* peering IE */
 239                             sdata->u.mesh.ie_len);
 240         if (!skb)
 241                 return -1;
 242         info = IEEE80211_SKB_CB(skb);
 243         skb_reserve(skb, local->tx_headroom);
 244         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 245         memset(mgmt, 0, hdr_len);
 246         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 247                                           IEEE80211_STYPE_ACTION);
 248         memcpy(mgmt->da, da, ETH_ALEN);
 249         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 250         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 251         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 252         mgmt->u.action.u.self_prot.action_code = action;
 253
 254         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 255                 /* capability info */
 256                 pos = skb_put(skb, 2);
 257                 memset(pos, 0, 2);
 258                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 259                         /* AID */
 260                         pos = skb_put(skb, 2);
 261                         memcpy(pos + 2, &plid, 2);
 262                 }
 263                 if (ieee80211_add_srates_ie(sdata, skb, true,
 264                                             local->oper_channel->band) ||
 265                     ieee80211_add_ext_srates_ie(sdata, skb, true,
 266                                                 local->oper_channel->band) ||
 267                     mesh_add_rsn_ie(skb, sdata) ||
 268                     mesh_add_meshid_ie(skb, sdata) ||
 269                     mesh_add_meshconf_ie(skb, sdata))
 270                         goto free;
 271         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 272                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 273                 if (mesh_add_meshid_ie(skb, sdata))
 274                         goto free;
 275         }
 276
 277         /* Add Mesh Peering Management element */
 278         switch (action) {
 279         case WLAN_SP_MESH_PEERING_OPEN:
 280                 break;
 281         case WLAN_SP_MESH_PEERING_CONFIRM:
 282                 ie_len += 2;
 283                 include_plid = true;
 284                 break;
 285         case WLAN_SP_MESH_PEERING_CLOSE:
 286                 if (plid) {
 287                         ie_len += 2;
 288                         include_plid = true;
 289                 }
 290                 ie_len += 2;    /* reason code */
 291                 break;
 292         default:
 293                 err = -EINVAL;
 294                 goto free;
 295         }
 296
 297         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 298                 goto free;
 299
 300         pos = skb_put(skb, 2 + ie_len);
 301         *pos++ = WLAN_EID_PEER_MGMT;
 302         *pos++ = ie_len;
 303         memcpy(pos, &peering_proto, 2);
 304         pos += 2;
 305         memcpy(pos, &llid, 2);
 306         pos += 2;
 307         if (include_plid) {
 308                 memcpy(pos, &plid, 2);
 309                 pos += 2;
 310         }
 311         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 312                 memcpy(pos, &reason, 2);
 313                 pos += 2;
 314         }
 315
 316         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 317                 if (mesh_add_ht_cap_ie(skb, sdata) ||
 318                     mesh_add_ht_oper_ie(skb, sdata))
 319                         goto free;
 320         }
 321
 322         if (mesh_add_vendor_ies(skb, sdata))
 323                 goto free;
 324
 325         ieee80211_tx_skb(sdata, skb);
 326         return 0;
 327 free:
 328         kfree_skb(skb);
 329         return err;
 330 }
 331
 332 /**
 333  * mesh_peer_init - initialize new mesh peer and return resulting sta_info
 334  *
 335  * @sdata: local meshif
 336  * @addr: peer's address
 337  * @elems: IEs from beacon or mesh peering frame
 338  *
 339  * call under RCU
 340  */
 341 static struct sta_info *mesh_peer_init(struct ieee80211_sub_if_data *sdata,
 342                                        u8 *addr,
 343                                        struct ieee802_11_elems *elems)
 344 {
 345         struct ieee80211_local *local = sdata->local;
 346         enum ieee80211_band band = local->oper_channel->band;
 347         struct ieee80211_supported_band *sband;
 348         u32 rates, basic_rates = 0;
 349         struct sta_info *sta;
 350         bool insert = false;
 351
 352         sband = local->hw.wiphy->bands[band];
 353         rates = ieee80211_sta_get_rates(local, elems, band, &basic_rates);
 354
 355         sta = sta_info_get(sdata, addr);
 356         if (!sta) {
 357                 /* Userspace handles peer allocation when security is enabled */
 358                 if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
 359                         cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 360                                                            elems->ie_start,
 361                                                            elems->total_len,
 362                                                            GFP_ATOMIC);
 363                         return NULL;
 364                 }
 365
 366                 sta = mesh_plink_alloc(sdata, addr);
 367                 if (!sta)
 368                         return NULL;
 369                 insert = true;
 370         }
 371
 372         spin_lock_bh(&sta->lock);
 373         sta->last_rx = jiffies;
 374         if (sta->plink_state == NL80211_PLINK_ESTAB) {
 375                 spin_unlock_bh(&sta->lock);
 376                 return sta;
 377         }
 378
 379         sta->sta.supp_rates[band] = rates;
 380         if (elems->ht_cap_elem &&
 381             sdata->vif.bss_conf.channel_type != NL80211_CHAN_NO_HT)
 382                 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 383                                                   elems->ht_cap_elem,
 384                                                   &sta->sta.ht_cap);
 385         else
 386                 memset(&sta->sta.ht_cap, 0, sizeof(sta->sta.ht_cap));
 387
 388         if (elems->ht_operation) {
 389                 if (!(elems->ht_operation->ht_param &
 390                       IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
 391                         sta->sta.ht_cap.cap &=
 392                                             ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 393                 sta->ch_type =
 394                         ieee80211_ht_oper_to_channel_type(elems->ht_operation);
 395         }
 396
 397         rate_control_rate_init(sta);
 398         spin_unlock_bh(&sta->lock);
 399
 400         if (insert && sta_info_insert(sta))
 401                 return NULL;
 402
 403         return sta;
 404 }
 405
 406 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 407                            u8 *hw_addr,
 408                            struct ieee802_11_elems *elems)
 409 {
 410         struct sta_info *sta;
 411
 412         rcu_read_lock();
 413         sta = mesh_peer_init(sdata, hw_addr, elems);
 414         if (!sta)
 415                 goto out;
 416
 417         if (mesh_peer_accepts_plinks(elems) &&
 418             sta->plink_state == NL80211_PLINK_LISTEN &&
 419             sdata->u.mesh.accepting_plinks &&
 420             sdata->u.mesh.mshcfg.auto_open_plinks &&
 421             rssi_threshold_check(sta, sdata))
 422                 mesh_plink_open(sta);
 423
 424 out:
 425         rcu_read_unlock();
 426 }
 427
 428 static void mesh_plink_timer(unsigned long data)
 429 {
 430         struct sta_info *sta;
 431         __le16 llid, plid, reason;
 432         struct ieee80211_sub_if_data *sdata;
 433
 434         /*
 435          * This STA is valid because sta_info_destroy() will
 436          * del_timer_sync() this timer after having made sure
 437          * it cannot be readded (by deleting the plink.)
 438          */
 439         sta = (struct sta_info *) data;
 440
 441         if (sta->sdata->local->quiescing) {
 442                 sta->plink_timer_was_running = true;
 443                 return;
 444         }
 445
 446         spin_lock_bh(&sta->lock);
 447         if (sta->ignore_plink_timer) {
 448                 sta->ignore_plink_timer = false;
 449                 spin_unlock_bh(&sta->lock);
 450                 return;
 451         }
 452         mpl_dbg(sta->sdata,
 453                 "Mesh plink timer for %pM fired on state %d\n",
 454                 sta->sta.addr, sta->plink_state);
 455         reason = 0;
 456         llid = sta->llid;
 457         plid = sta->plid;
 458         sdata = sta->sdata;
 459
 460         switch (sta->plink_state) {
 461         case NL80211_PLINK_OPN_RCVD:
 462         case NL80211_PLINK_OPN_SNT:
 463                 /* retry timer */
 464                 if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
 465                         u32 rand;
 466                         mpl_dbg(sta->sdata,
 467                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 468                                 sta->sta.addr, sta->plink_retries,
 469                                 sta->plink_timeout);
 470                         get_random_bytes(&rand, sizeof(u32));
 471                         sta->plink_timeout = sta->plink_timeout +
 472                                              rand % sta->plink_timeout;
 473                         ++sta->plink_retries;
 474                         mod_plink_timer(sta, sta->plink_timeout);
 475                         spin_unlock_bh(&sta->lock);
 476                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 477                                             sta->sta.addr, llid, 0, 0);
 478                         break;
 479                 }
 480                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 481                 /* fall through on else */
 482         case NL80211_PLINK_CNF_RCVD:
 483                 /* confirm timer */
 484                 if (!reason)
 485                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 486                 sta->plink_state = NL80211_PLINK_HOLDING;
 487                 mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 488                 spin_unlock_bh(&sta->lock);
 489                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 490                                     sta->sta.addr, llid, plid, reason);
 491                 break;
 492         case NL80211_PLINK_HOLDING:
 493                 /* holding timer */
 494                 del_timer(&sta->plink_timer);
 495                 mesh_plink_fsm_restart(sta);
 496                 spin_unlock_bh(&sta->lock);
 497                 break;
 498         default:
 499                 spin_unlock_bh(&sta->lock);
 500                 break;
 501         }
 502 }
 503
 504 #ifdef CONFIG_PM
 505 void mesh_plink_quiesce(struct sta_info *sta)
 506 {
 507         if (del_timer_sync(&sta->plink_timer))
 508                 sta->plink_timer_was_running = true;
 509 }
 510
 511 void mesh_plink_restart(struct sta_info *sta)
 512 {
 513         if (sta->plink_timer_was_running) {
 514                 add_timer(&sta->plink_timer);
 515                 sta->plink_timer_was_running = false;
 516         }
 517 }
 518 #endif
 519
 520 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 521 {
 522         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 523         sta->plink_timer.data = (unsigned long) sta;
 524         sta->plink_timer.function = mesh_plink_timer;
 525         sta->plink_timeout = timeout;
 526         add_timer(&sta->plink_timer);
 527 }
 528
 529 int mesh_plink_open(struct sta_info *sta)
 530 {
 531         __le16 llid;
 532         struct ieee80211_sub_if_data *sdata = sta->sdata;
 533
 534         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 535                 return -EPERM;
 536
 537         spin_lock_bh(&sta->lock);
 538         get_random_bytes(&llid, 2);
 539         sta->llid = llid;
 540         if (sta->plink_state != NL80211_PLINK_LISTEN &&
 541             sta->plink_state != NL80211_PLINK_BLOCKED) {
 542                 spin_unlock_bh(&sta->lock);
 543                 return -EBUSY;
 544         }
 545         sta->plink_state = NL80211_PLINK_OPN_SNT;
 546         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 547         spin_unlock_bh(&sta->lock);
 548         mpl_dbg(sdata,
 549                 "Mesh plink: starting establishment with %pM\n",
 550                 sta->sta.addr);
 551
 552         return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 553                                    sta->sta.addr, llid, 0, 0);
 554 }
 555
 556 void mesh_plink_block(struct sta_info *sta)
 557 {
 558         struct ieee80211_sub_if_data *sdata = sta->sdata;
 559         u32 changed;
 560
 561         spin_lock_bh(&sta->lock);
 562         changed = __mesh_plink_deactivate(sta);
 563         sta->plink_state = NL80211_PLINK_BLOCKED;
 564         spin_unlock_bh(&sta->lock);
 565
 566         ieee80211_bss_info_change_notify(sdata, changed);
 567 }
 568
 569
 570 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 571                          size_t len, struct ieee80211_rx_status *rx_status)
 572 {
 573         struct ieee802_11_elems elems;
 574         struct sta_info *sta;
 575         enum plink_event event;
 576         enum ieee80211_self_protected_actioncode ftype;
 577         size_t baselen;
 578         bool matches_local = true;
 579         u8 ie_len;
 580         u8 *baseaddr;
 581         u32 changed = 0;
 582         __le16 plid, llid, reason;
 583         static const char *mplstates[] = {
 584                 [NL80211_PLINK_LISTEN] = "LISTEN",
 585                 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 586                 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 587                 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 588                 [NL80211_PLINK_ESTAB] = "ESTAB",
 589                 [NL80211_PLINK_HOLDING] = "HOLDING",
 590                 [NL80211_PLINK_BLOCKED] = "BLOCKED"
 591         };
 592
 593         /* need action_code, aux */
 594         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 595                 return;
 596
 597         if (is_multicast_ether_addr(mgmt->da)) {
 598                 mpl_dbg(sdata,
 599                         "Mesh plink: ignore frame from multicast address\n");
 600                 return;
 601         }
 602
 603         baseaddr = mgmt->u.action.u.self_prot.variable;
 604         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 605         if (mgmt->u.action.u.self_prot.action_code ==
 606                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 607                 baseaddr += 4;
 608                 baselen += 4;
 609         }
 610         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 611         if (!elems.peering) {
 612                 mpl_dbg(sdata,
 613                         "Mesh plink: missing necessary peer link ie\n");
 614                 return;
 615         }
 616         if (elems.rsn_len &&
 617                         sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 618                 mpl_dbg(sdata,
 619                         "Mesh plink: can't establish link with secure peer\n");
 620                 return;
 621         }
 622
 623         ftype = mgmt->u.action.u.self_prot.action_code;
 624         ie_len = elems.peering_len;
 625         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 626             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 627             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 628                                                         && ie_len != 8)) {
 629                 mpl_dbg(sdata,
 630                         "Mesh plink: incorrect plink ie length %d %d\n",
 631                         ftype, ie_len);
 632                 return;
 633         }
 634
 635         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 636                                 (!elems.mesh_id || !elems.mesh_config)) {
 637                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
 638                 return;
 639         }
 640         /* Note the lines below are correct, the llid in the frame is the plid
 641          * from the point of view of this host.
 642          */
 643         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 644         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 645             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 646                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 647
 648         rcu_read_lock();
 649
 650         sta = sta_info_get(sdata, mgmt->sa);
 651         if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 652                 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 653                 rcu_read_unlock();
 654                 return;
 655         }
 656
 657         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 658             !rssi_threshold_check(sta, sdata)) {
 659                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
 660                         mgmt->sa);
 661                 rcu_read_unlock();
 662                 return;
 663         }
 664
 665         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 666                 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
 667                 rcu_read_unlock();
 668                 return;
 669         }
 670
 671         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 672                 rcu_read_unlock();
 673                 return;
 674         }
 675
 676         /* Now we will figure out the appropriate event... */
 677         event = PLINK_UNDEFINED;
 678         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 679             !mesh_matches_local(sdata, &elems)) {
 680                 matches_local = false;
 681                 switch (ftype) {
 682                 case WLAN_SP_MESH_PEERING_OPEN:
 683                         event = OPN_RJCT;
 684                         break;
 685                 case WLAN_SP_MESH_PEERING_CONFIRM:
 686                         event = CNF_RJCT;
 687                         break;
 688                 default:
 689                         break;
 690                 }
 691         }
 692
 693         if (!sta && !matches_local) {
 694                 rcu_read_unlock();
 695                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 696                 llid = 0;
 697                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 698                                     mgmt->sa, llid, plid, reason);
 699                 return;
 700         } else if (!sta) {
 701                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 702                 if (!mesh_plink_free_count(sdata)) {
 703                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 704                         rcu_read_unlock();
 705                         return;
 706                 }
 707                 event = OPN_ACPT;
 708         } else if (matches_local) {
 709                 switch (ftype) {
 710                 case WLAN_SP_MESH_PEERING_OPEN:
 711                         if (!mesh_plink_free_count(sdata) ||
 712                             (sta->plid && sta->plid != plid))
 713                                 event = OPN_IGNR;
 714                         else
 715                                 event = OPN_ACPT;
 716                         break;
 717                 case WLAN_SP_MESH_PEERING_CONFIRM:
 718                         if (!mesh_plink_free_count(sdata) ||
 719                             (sta->llid != llid || sta->plid != plid))
 720                                 event = CNF_IGNR;
 721                         else
 722                                 event = CNF_ACPT;
 723                         break;
 724                 case WLAN_SP_MESH_PEERING_CLOSE:
 725                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 726                                 /* Do not check for llid or plid. This does not
 727                                  * follow the standard but since multiple plinks
 728                                  * per sta are not supported, it is necessary in
 729                                  * order to avoid a livelock when MP A sees an
 730                                  * establish peer link to MP B but MP B does not
 731                                  * see it. This can be caused by a timeout in
 732                                  * B's peer link establishment or B beign
 733                                  * restarted.
 734                                  */
 735                                 event = CLS_ACPT;
 736                         else if (sta->plid != plid)
 737                                 event = CLS_IGNR;
 738                         else if (ie_len == 7 && sta->llid != llid)
 739                                 event = CLS_IGNR;
 740                         else
 741                                 event = CLS_ACPT;
 742                         break;
 743                 default:
 744                         mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
 745                         rcu_read_unlock();
 746                         return;
 747                 }
 748         }
 749
 750         if (event == OPN_ACPT) {
 751                 /* allocate sta entry if necessary and update info */
 752                 sta = mesh_peer_init(sdata, mgmt->sa, &elems);
 753                 if (!sta) {
 754                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
 755                         rcu_read_unlock();
 756                         return;
 757                 }
 758         }
 759
 760         mpl_dbg(sdata,
 761                 "Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 762                 mgmt->sa, mplstates[sta->plink_state],
 763                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 764                 event);
 765         reason = 0;
 766         spin_lock_bh(&sta->lock);
 767         switch (sta->plink_state) {
 768                 /* spin_unlock as soon as state is updated at each case */
 769         case NL80211_PLINK_LISTEN:
 770                 switch (event) {
 771                 case CLS_ACPT:
 772                         mesh_plink_fsm_restart(sta);
 773                         spin_unlock_bh(&sta->lock);
 774                         break;
 775                 case OPN_ACPT:
 776                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 777                         sta->plid = plid;
 778                         get_random_bytes(&llid, 2);
 779                         sta->llid = llid;
 780                         mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 781                         spin_unlock_bh(&sta->lock);
 782                         mesh_plink_frame_tx(sdata,
 783                                             WLAN_SP_MESH_PEERING_OPEN,
 784                                             sta->sta.addr, llid, 0, 0);
 785                         mesh_plink_frame_tx(sdata,
 786                                             WLAN_SP_MESH_PEERING_CONFIRM,
 787                                             sta->sta.addr, llid, plid, 0);
 788                         break;
 789                 default:
 790                         spin_unlock_bh(&sta->lock);
 791                         break;
 792                 }
 793                 break;
 794
 795         case NL80211_PLINK_OPN_SNT:
 796                 switch (event) {
 797                 case OPN_RJCT:
 798                 case CNF_RJCT:
 799                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 800                 case CLS_ACPT:
 801                         if (!reason)
 802                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 803                         sta->reason = reason;
 804                         sta->plink_state = NL80211_PLINK_HOLDING;
 805                         if (!mod_plink_timer(sta,
 806                                              dot11MeshHoldingTimeout(sdata)))
 807                                 sta->ignore_plink_timer = true;
 808
 809                         llid = sta->llid;
 810                         spin_unlock_bh(&sta->lock);
 811                         mesh_plink_frame_tx(sdata,
 812                                             WLAN_SP_MESH_PEERING_CLOSE,
 813                                             sta->sta.addr, llid, plid, reason);
 814                         break;
 815                 case OPN_ACPT:
 816                         /* retry timer is left untouched */
 817                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 818                         sta->plid = plid;
 819                         llid = sta->llid;
 820                         spin_unlock_bh(&sta->lock);
 821                         mesh_plink_frame_tx(sdata,
 822                                             WLAN_SP_MESH_PEERING_CONFIRM,
 823                                             sta->sta.addr, llid, plid, 0);
 824                         break;
 825                 case CNF_ACPT:
 826                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 827                         if (!mod_plink_timer(sta,
 828                                              dot11MeshConfirmTimeout(sdata)))
 829                                 sta->ignore_plink_timer = true;
 830
 831                         spin_unlock_bh(&sta->lock);
 832                         break;
 833                 default:
 834                         spin_unlock_bh(&sta->lock);
 835                         break;
 836                 }
 837                 break;
 838
 839         case NL80211_PLINK_OPN_RCVD:
 840                 switch (event) {
 841                 case OPN_RJCT:
 842                 case CNF_RJCT:
 843                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 844                 case CLS_ACPT:
 845                         if (!reason)
 846                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 847                         sta->reason = reason;
 848                         sta->plink_state = NL80211_PLINK_HOLDING;
 849                         if (!mod_plink_timer(sta,
 850                                              dot11MeshHoldingTimeout(sdata)))
 851                                 sta->ignore_plink_timer = true;
 852
 853                         llid = sta->llid;
 854                         spin_unlock_bh(&sta->lock);
 855                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 856                                             sta->sta.addr, llid, plid, reason);
 857                         break;
 858                 case OPN_ACPT:
 859                         llid = sta->llid;
 860                         spin_unlock_bh(&sta->lock);
 861                         mesh_plink_frame_tx(sdata,
 862                                             WLAN_SP_MESH_PEERING_CONFIRM,
 863                                             sta->sta.addr, llid, plid, 0);
 864                         break;
 865                 case CNF_ACPT:
 866                         del_timer(&sta->plink_timer);
 867                         sta->plink_state = NL80211_PLINK_ESTAB;
 868                         spin_unlock_bh(&sta->lock);
 869                         changed |= mesh_plink_inc_estab_count(sdata);
 870                         changed |= mesh_set_ht_prot_mode(sdata);
 871                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 872                                 sta->sta.addr);
 873                         break;
 874                 default:
 875                         spin_unlock_bh(&sta->lock);
 876                         break;
 877                 }
 878                 break;
 879
 880         case NL80211_PLINK_CNF_RCVD:
 881                 switch (event) {
 882                 case OPN_RJCT:
 883                 case CNF_RJCT:
 884                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 885                 case CLS_ACPT:
 886                         if (!reason)
 887                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 888                         sta->reason = reason;
 889                         sta->plink_state = NL80211_PLINK_HOLDING;
 890                         if (!mod_plink_timer(sta,
 891                                              dot11MeshHoldingTimeout(sdata)))
 892                                 sta->ignore_plink_timer = true;
 893
 894                         llid = sta->llid;
 895                         spin_unlock_bh(&sta->lock);
 896                         mesh_plink_frame_tx(sdata,
 897                                             WLAN_SP_MESH_PEERING_CLOSE,
 898                                             sta->sta.addr, llid, plid, reason);
 899                         break;
 900                 case OPN_ACPT:
 901                         del_timer(&sta->plink_timer);
 902                         sta->plink_state = NL80211_PLINK_ESTAB;
 903                         spin_unlock_bh(&sta->lock);
 904                         changed |= mesh_plink_inc_estab_count(sdata);
 905                         changed |= mesh_set_ht_prot_mode(sdata);
 906                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 907                                 sta->sta.addr);
 908                         mesh_plink_frame_tx(sdata,
 909                                             WLAN_SP_MESH_PEERING_CONFIRM,
 910                                             sta->sta.addr, llid, plid, 0);
 911                         break;
 912                 default:
 913                         spin_unlock_bh(&sta->lock);
 914                         break;
 915                 }
 916                 break;
 917
 918         case NL80211_PLINK_ESTAB:
 919                 switch (event) {
 920                 case CLS_ACPT:
 921                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 922                         sta->reason = reason;
 923                         changed |= __mesh_plink_deactivate(sta);
 924                         sta->plink_state = NL80211_PLINK_HOLDING;
 925                         llid = sta->llid;
 926                         mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 927                         spin_unlock_bh(&sta->lock);
 928                         changed |= mesh_set_ht_prot_mode(sdata);
 929                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 930                                             sta->sta.addr, llid, plid, reason);
 931                         break;
 932                 case OPN_ACPT:
 933                         llid = sta->llid;
 934                         spin_unlock_bh(&sta->lock);
 935                         mesh_plink_frame_tx(sdata,
 936                                             WLAN_SP_MESH_PEERING_CONFIRM,
 937                                             sta->sta.addr, llid, plid, 0);
 938                         break;
 939                 default:
 940                         spin_unlock_bh(&sta->lock);
 941                         break;
 942                 }
 943                 break;
 944         case NL80211_PLINK_HOLDING:
 945                 switch (event) {
 946                 case CLS_ACPT:
 947                         if (del_timer(&sta->plink_timer))
 948                                 sta->ignore_plink_timer = 1;
 949                         mesh_plink_fsm_restart(sta);
 950                         spin_unlock_bh(&sta->lock);
 951                         break;
 952                 case OPN_ACPT:
 953                 case CNF_ACPT:
 954                 case OPN_RJCT:
 955                 case CNF_RJCT:
 956                         llid = sta->llid;
 957                         reason = sta->reason;
 958                         spin_unlock_bh(&sta->lock);
 959                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 960                                             sta->sta.addr, llid, plid, reason);
 961                         break;
 962                 default:
 963                         spin_unlock_bh(&sta->lock);
 964                 }
 965                 break;
 966         default:
 967                 /* should not get here, PLINK_BLOCKED is dealt with at the
 968                  * beginning of the function
 969                  */
 970                 spin_unlock_bh(&sta->lock);
 971                 break;
 972         }
 973
 974         rcu_read_unlock();
 975
 976         if (changed)
 977                 ieee80211_bss_info_change_notify(sdata, changed);
 978 }