Pileus Git - ~andy/linux/blob - 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 /* We only need a valid sta if user configured a minimum rssi_threshold. */
  23 #define rssi_threshold_check(sta, sdata) \
  24                 (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
  25                 (sta && (s8) -ewma_read(&sta->avg_signal) > \
  26                 sdata->u.mesh.mshcfg.rssi_threshold))
  27
  28 enum plink_event {
  29         PLINK_UNDEFINED,
  30         OPN_ACPT,
  31         OPN_RJCT,
  32         OPN_IGNR,
  33         CNF_ACPT,
  34         CNF_RJCT,
  35         CNF_IGNR,
  36         CLS_ACPT,
  37         CLS_IGNR
  38 };
  39
  40 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
  41                 enum ieee80211_self_protected_actioncode action,
  42                 u8 *da, __le16 llid, __le16 plid, __le16 reason);
  43
  44 /**
  45  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  46  *
  47  * @sta: mesh peer link to restart
  48  *
  49  * Locking: this function must be called holding sta->lock
  50  */
  51 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  52 {
  53         sta->plink_state = NL80211_PLINK_LISTEN;
  54         sta->llid = sta->plid = sta->reason = 0;
  55         sta->plink_retries = 0;
  56 }
  57
  58 /**
  59  * mesh_set_ht_prot_mode - set correct HT protection mode
  60  *
  61  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
  62  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
  63  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
  64  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
  65  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
  66  * HT20 peer is present. Otherwise no-protection mode is selected.
  67  */
  68 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
  69 {
  70         struct ieee80211_local *local = sdata->local;
  71         struct sta_info *sta;
  72         u32 changed = 0;
  73         u16 ht_opmode;
  74         bool non_ht_sta = false, ht20_sta = false;
  75
  76         if (sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT)
  77                 return 0;
  78
  79         rcu_read_lock();
  80         list_for_each_entry_rcu(sta, &local->sta_list, list) {
  81                 if (sdata != sta->sdata ||
  82                     sta->plink_state != NL80211_PLINK_ESTAB)
  83                         continue;
  84
  85                 switch (sta->ch_width) {
  86                 case NL80211_CHAN_WIDTH_20_NOHT:
  87                         mpl_dbg(sdata,
  88                                 "mesh_plink %pM: nonHT sta (%pM) is present\n",
  89                                 sdata->vif.addr, sta->sta.addr);
  90                         non_ht_sta = true;
  91                         goto out;
  92                 case NL80211_CHAN_WIDTH_20:
  93                         mpl_dbg(sdata,
  94                                 "mesh_plink %pM: HT20 sta (%pM) is present\n",
  95                                 sdata->vif.addr, sta->sta.addr);
  96                         ht20_sta = true;
  97                 default:
  98                         break;
  99                 }
 100         }
 101 out:
 102         rcu_read_unlock();
 103
 104         if (non_ht_sta)
 105                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 106         else if (ht20_sta &&
 107                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 108                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 109         else
 110                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 111
 112         if (sdata->vif.bss_conf.ht_operation_mode != ht_opmode) {
 113                 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 114                 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 115                 changed = BSS_CHANGED_HT;
 116                 mpl_dbg(sdata,
 117                         "mesh_plink %pM: protection mode changed to %d\n",
 118                         sdata->vif.addr, ht_opmode);
 119         }
 120
 121         return changed;
 122 }
 123
 124 /**
 125  * __mesh_plink_deactivate - deactivate mesh peer link
 126  *
 127  * @sta: mesh peer link to deactivate
 128  *
 129  * All mesh paths with this peer as next hop will be flushed
 130  * Returns beacon changed flag if the beacon content changed.
 131  *
 132  * Locking: the caller must hold sta->lock
 133  */
 134 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 135 {
 136         struct ieee80211_sub_if_data *sdata = sta->sdata;
 137         u32 changed = 0;
 138
 139         if (sta->plink_state == NL80211_PLINK_ESTAB)
 140                 changed = mesh_plink_dec_estab_count(sdata);
 141         sta->plink_state = NL80211_PLINK_BLOCKED;
 142         mesh_path_flush_by_nexthop(sta);
 143
 144         return changed;
 145 }
 146
 147 /**
 148  * mesh_plink_deactivate - deactivate mesh peer link
 149  *
 150  * @sta: mesh peer link to deactivate
 151  *
 152  * All mesh paths with this peer as next hop will be flushed
 153  */
 154 void mesh_plink_deactivate(struct sta_info *sta)
 155 {
 156         struct ieee80211_sub_if_data *sdata = sta->sdata;
 157         u32 changed;
 158
 159         spin_lock_bh(&sta->lock);
 160         changed = __mesh_plink_deactivate(sta);
 161         sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 162         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 163                             sta->sta.addr, sta->llid, sta->plid,
 164                             sta->reason);
 165         spin_unlock_bh(&sta->lock);
 166
 167         ieee80211_bss_info_change_notify(sdata, changed);
 168 }
 169
 170 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 171                 enum ieee80211_self_protected_actioncode action,
 172                 u8 *da, __le16 llid, __le16 plid, __le16 reason) {
 173         struct ieee80211_local *local = sdata->local;
 174         struct sk_buff *skb;
 175         struct ieee80211_tx_info *info;
 176         struct ieee80211_mgmt *mgmt;
 177         bool include_plid = false;
 178         u16 peering_proto = 0;
 179         u8 *pos, ie_len = 4;
 180         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 181                       sizeof(mgmt->u.action.u.self_prot);
 182         int err = -ENOMEM;
 183
 184         skb = dev_alloc_skb(local->tx_headroom +
 185                             hdr_len +
 186                             2 + /* capability info */
 187                             2 + /* AID */
 188                             2 + 8 + /* supported rates */
 189                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 190                             2 + sdata->u.mesh.mesh_id_len +
 191                             2 + sizeof(struct ieee80211_meshconf_ie) +
 192                             2 + sizeof(struct ieee80211_ht_cap) +
 193                             2 + sizeof(struct ieee80211_ht_operation) +
 194                             2 + 8 + /* peering IE */
 195                             sdata->u.mesh.ie_len);
 196         if (!skb)
 197                 return -1;
 198         info = IEEE80211_SKB_CB(skb);
 199         skb_reserve(skb, local->tx_headroom);
 200         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 201         memset(mgmt, 0, hdr_len);
 202         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 203                                           IEEE80211_STYPE_ACTION);
 204         memcpy(mgmt->da, da, ETH_ALEN);
 205         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 206         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 207         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 208         mgmt->u.action.u.self_prot.action_code = action;
 209
 210         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 211                 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 212
 213                 /* capability info */
 214                 pos = skb_put(skb, 2);
 215                 memset(pos, 0, 2);
 216                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 217                         /* AID */
 218                         pos = skb_put(skb, 2);
 219                         memcpy(pos + 2, &plid, 2);
 220                 }
 221                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 222                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 223                     mesh_add_rsn_ie(skb, sdata) ||
 224                     mesh_add_meshid_ie(skb, sdata) ||
 225                     mesh_add_meshconf_ie(skb, sdata))
 226                         goto free;
 227         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 228                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 229                 if (mesh_add_meshid_ie(skb, sdata))
 230                         goto free;
 231         }
 232
 233         /* Add Mesh Peering Management element */
 234         switch (action) {
 235         case WLAN_SP_MESH_PEERING_OPEN:
 236                 break;
 237         case WLAN_SP_MESH_PEERING_CONFIRM:
 238                 ie_len += 2;
 239                 include_plid = true;
 240                 break;
 241         case WLAN_SP_MESH_PEERING_CLOSE:
 242                 if (plid) {
 243                         ie_len += 2;
 244                         include_plid = true;
 245                 }
 246                 ie_len += 2;    /* reason code */
 247                 break;
 248         default:
 249                 err = -EINVAL;
 250                 goto free;
 251         }
 252
 253         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 254                 goto free;
 255
 256         pos = skb_put(skb, 2 + ie_len);
 257         *pos++ = WLAN_EID_PEER_MGMT;
 258         *pos++ = ie_len;
 259         memcpy(pos, &peering_proto, 2);
 260         pos += 2;
 261         memcpy(pos, &llid, 2);
 262         pos += 2;
 263         if (include_plid) {
 264                 memcpy(pos, &plid, 2);
 265                 pos += 2;
 266         }
 267         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 268                 memcpy(pos, &reason, 2);
 269                 pos += 2;
 270         }
 271
 272         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 273                 if (mesh_add_ht_cap_ie(skb, sdata) ||
 274                     mesh_add_ht_oper_ie(skb, sdata))
 275                         goto free;
 276         }
 277
 278         if (mesh_add_vendor_ies(skb, sdata))
 279                 goto free;
 280
 281         ieee80211_tx_skb(sdata, skb);
 282         return 0;
 283 free:
 284         kfree_skb(skb);
 285         return err;
 286 }
 287
 288 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 289                                struct sta_info *sta,
 290                                struct ieee802_11_elems *elems, bool insert)
 291 {
 292         struct ieee80211_local *local = sdata->local;
 293         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 294         struct ieee80211_supported_band *sband;
 295         u32 rates, basic_rates = 0;
 296
 297         sband = local->hw.wiphy->bands[band];
 298         rates = ieee80211_sta_get_rates(local, elems, band, &basic_rates);
 299
 300         spin_lock_bh(&sta->lock);
 301         sta->last_rx = jiffies;
 302
 303         /* rates and capabilities don't change during peering */
 304         if (sta->plink_state == NL80211_PLINK_ESTAB)
 305                 goto out;
 306
 307         sta->sta.supp_rates[band] = rates;
 308         if (elems->ht_cap_elem &&
 309             sdata->vif.bss_conf.chandef.width != NL80211_CHAN_WIDTH_20_NOHT)
 310                 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 311                                                   elems->ht_cap_elem,
 312                                                   &sta->sta.ht_cap);
 313         else
 314                 memset(&sta->sta.ht_cap, 0, sizeof(sta->sta.ht_cap));
 315
 316         if (elems->ht_operation) {
 317                 struct cfg80211_chan_def chandef;
 318
 319                 if (!(elems->ht_operation->ht_param &
 320                       IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
 321                         sta->sta.ht_cap.cap &=
 322                                             ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 323                 ieee80211_ht_oper_to_chandef(sdata->vif.bss_conf.chandef.chan,
 324                                              elems->ht_operation, &chandef);
 325                 sta->ch_width = chandef.width;
 326         }
 327
 328         if (insert)
 329                 rate_control_rate_init(sta);
 330 out:
 331         spin_unlock_bh(&sta->lock);
 332 }
 333
 334 static struct sta_info *
 335 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 336 {
 337         struct sta_info *sta;
 338
 339         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 340                 return NULL;
 341
 342         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 343         if (!sta)
 344                 return NULL;
 345
 346         sta->plink_state = NL80211_PLINK_LISTEN;
 347         init_timer(&sta->plink_timer);
 348
 349         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 350         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 351         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 352
 353         set_sta_flag(sta, WLAN_STA_WME);
 354
 355         return sta;
 356 }
 357
 358 static struct sta_info *
 359 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 360                     struct ieee802_11_elems *elems)
 361 {
 362         struct sta_info *sta = NULL;
 363
 364         /* Userspace handles peer allocation when security is enabled */
 365         if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 366                 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 367                                                    elems->ie_start,
 368                                                    elems->total_len,
 369                                                    GFP_KERNEL);
 370         else
 371                 sta = __mesh_sta_info_alloc(sdata, addr);
 372
 373         return sta;
 374 }
 375
 376 /*
 377  * mesh_sta_info_get - return mesh sta info entry for @addr.
 378  *
 379  * @sdata: local meshif
 380  * @addr: peer's address
 381  * @elems: IEs from beacon or mesh peering frame.
 382  *
 383  * Return existing or newly allocated sta_info under RCU read lock.
 384  * (re)initialize with given IEs.
 385  */
 386 static struct sta_info *
 387 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 388                   u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 389 {
 390         struct sta_info *sta = NULL;
 391
 392         rcu_read_lock();
 393         sta = sta_info_get(sdata, addr);
 394         if (sta) {
 395                 mesh_sta_info_init(sdata, sta, elems, false);
 396         } else {
 397                 rcu_read_unlock();
 398                 /* can't run atomic */
 399                 sta = mesh_sta_info_alloc(sdata, addr, elems);
 400                 if (!sta) {
 401                         rcu_read_lock();
 402                         return NULL;
 403                 }
 404
 405                 if (sta_info_insert_rcu(sta))
 406                         return NULL;
 407         }
 408
 409         return sta;
 410 }
 411
 412 /*
 413  * mesh_neighbour_update - update or initialize new mesh neighbor.
 414  *
 415  * @sdata: local meshif
 416  * @addr: peer's address
 417  * @elems: IEs from beacon or mesh peering frame
 418  *
 419  * Initiates peering if appropriate.
 420  */
 421 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 422                            u8 *hw_addr,
 423                            struct ieee802_11_elems *elems)
 424 {
 425         struct sta_info *sta;
 426
 427         sta = mesh_sta_info_get(sdata, hw_addr, elems);
 428         if (!sta)
 429                 goto out;
 430
 431         if (mesh_peer_accepts_plinks(elems) &&
 432             sta->plink_state == NL80211_PLINK_LISTEN &&
 433             sdata->u.mesh.accepting_plinks &&
 434             sdata->u.mesh.mshcfg.auto_open_plinks &&
 435             rssi_threshold_check(sta, sdata))
 436                 mesh_plink_open(sta);
 437
 438 out:
 439         rcu_read_unlock();
 440 }
 441
 442 static void mesh_plink_timer(unsigned long data)
 443 {
 444         struct sta_info *sta;
 445         __le16 llid, plid, reason;
 446         struct ieee80211_sub_if_data *sdata;
 447         struct mesh_config *mshcfg;
 448
 449         /*
 450          * This STA is valid because sta_info_destroy() will
 451          * del_timer_sync() this timer after having made sure
 452          * it cannot be readded (by deleting the plink.)
 453          */
 454         sta = (struct sta_info *) data;
 455
 456         if (sta->sdata->local->quiescing) {
 457                 sta->plink_timer_was_running = true;
 458                 return;
 459         }
 460
 461         spin_lock_bh(&sta->lock);
 462         if (sta->ignore_plink_timer) {
 463                 sta->ignore_plink_timer = false;
 464                 spin_unlock_bh(&sta->lock);
 465                 return;
 466         }
 467         mpl_dbg(sta->sdata,
 468                 "Mesh plink timer for %pM fired on state %d\n",
 469                 sta->sta.addr, sta->plink_state);
 470         reason = 0;
 471         llid = sta->llid;
 472         plid = sta->plid;
 473         sdata = sta->sdata;
 474         mshcfg = &sdata->u.mesh.mshcfg;
 475
 476         switch (sta->plink_state) {
 477         case NL80211_PLINK_OPN_RCVD:
 478         case NL80211_PLINK_OPN_SNT:
 479                 /* retry timer */
 480                 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) {
 481                         u32 rand;
 482                         mpl_dbg(sta->sdata,
 483                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 484                                 sta->sta.addr, sta->plink_retries,
 485                                 sta->plink_timeout);
 486                         get_random_bytes(&rand, sizeof(u32));
 487                         sta->plink_timeout = sta->plink_timeout +
 488                                              rand % sta->plink_timeout;
 489                         ++sta->plink_retries;
 490                         mod_plink_timer(sta, sta->plink_timeout);
 491                         spin_unlock_bh(&sta->lock);
 492                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 493                                             sta->sta.addr, llid, 0, 0);
 494                         break;
 495                 }
 496                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 497                 /* fall through on else */
 498         case NL80211_PLINK_CNF_RCVD:
 499                 /* confirm timer */
 500                 if (!reason)
 501                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 502                 sta->plink_state = NL80211_PLINK_HOLDING;
 503                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 504                 spin_unlock_bh(&sta->lock);
 505                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 506                                     sta->sta.addr, llid, plid, reason);
 507                 break;
 508         case NL80211_PLINK_HOLDING:
 509                 /* holding timer */
 510                 del_timer(&sta->plink_timer);
 511                 mesh_plink_fsm_restart(sta);
 512                 spin_unlock_bh(&sta->lock);
 513                 break;
 514         default:
 515                 spin_unlock_bh(&sta->lock);
 516                 break;
 517         }
 518 }
 519
 520 #ifdef CONFIG_PM
 521 void mesh_plink_quiesce(struct sta_info *sta)
 522 {
 523         if (del_timer_sync(&sta->plink_timer))
 524                 sta->plink_timer_was_running = true;
 525 }
 526
 527 void mesh_plink_restart(struct sta_info *sta)
 528 {
 529         if (sta->plink_timer_was_running) {
 530                 add_timer(&sta->plink_timer);
 531                 sta->plink_timer_was_running = false;
 532         }
 533 }
 534 #endif
 535
 536 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 537 {
 538         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 539         sta->plink_timer.data = (unsigned long) sta;
 540         sta->plink_timer.function = mesh_plink_timer;
 541         sta->plink_timeout = timeout;
 542         add_timer(&sta->plink_timer);
 543 }
 544
 545 int mesh_plink_open(struct sta_info *sta)
 546 {
 547         __le16 llid;
 548         struct ieee80211_sub_if_data *sdata = sta->sdata;
 549
 550         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 551                 return -EPERM;
 552
 553         spin_lock_bh(&sta->lock);
 554         get_random_bytes(&llid, 2);
 555         sta->llid = llid;
 556         if (sta->plink_state != NL80211_PLINK_LISTEN &&
 557             sta->plink_state != NL80211_PLINK_BLOCKED) {
 558                 spin_unlock_bh(&sta->lock);
 559                 return -EBUSY;
 560         }
 561         sta->plink_state = NL80211_PLINK_OPN_SNT;
 562         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 563         spin_unlock_bh(&sta->lock);
 564         mpl_dbg(sdata,
 565                 "Mesh plink: starting establishment with %pM\n",
 566                 sta->sta.addr);
 567
 568         return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 569                                    sta->sta.addr, llid, 0, 0);
 570 }
 571
 572 void mesh_plink_block(struct sta_info *sta)
 573 {
 574         struct ieee80211_sub_if_data *sdata = sta->sdata;
 575         u32 changed;
 576
 577         spin_lock_bh(&sta->lock);
 578         changed = __mesh_plink_deactivate(sta);
 579         sta->plink_state = NL80211_PLINK_BLOCKED;
 580         spin_unlock_bh(&sta->lock);
 581
 582         ieee80211_bss_info_change_notify(sdata, changed);
 583 }
 584
 585
 586 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 587                          size_t len, struct ieee80211_rx_status *rx_status)
 588 {
 589         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 590         struct ieee802_11_elems elems;
 591         struct sta_info *sta;
 592         enum plink_event event;
 593         enum ieee80211_self_protected_actioncode ftype;
 594         size_t baselen;
 595         bool matches_local = true;
 596         u8 ie_len;
 597         u8 *baseaddr;
 598         u32 changed = 0;
 599         __le16 plid, llid, reason;
 600         static const char *mplstates[] = {
 601                 [NL80211_PLINK_LISTEN] = "LISTEN",
 602                 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 603                 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 604                 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 605                 [NL80211_PLINK_ESTAB] = "ESTAB",
 606                 [NL80211_PLINK_HOLDING] = "HOLDING",
 607                 [NL80211_PLINK_BLOCKED] = "BLOCKED"
 608         };
 609
 610         /* need action_code, aux */
 611         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 612                 return;
 613
 614         if (is_multicast_ether_addr(mgmt->da)) {
 615                 mpl_dbg(sdata,
 616                         "Mesh plink: ignore frame from multicast address\n");
 617                 return;
 618         }
 619
 620         baseaddr = mgmt->u.action.u.self_prot.variable;
 621         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 622         if (mgmt->u.action.u.self_prot.action_code ==
 623                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 624                 baseaddr += 4;
 625                 baselen += 4;
 626         }
 627         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 628         if (!elems.peering) {
 629                 mpl_dbg(sdata,
 630                         "Mesh plink: missing necessary peer link ie\n");
 631                 return;
 632         }
 633         if (elems.rsn_len &&
 634                         sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 635                 mpl_dbg(sdata,
 636                         "Mesh plink: can't establish link with secure peer\n");
 637                 return;
 638         }
 639
 640         ftype = mgmt->u.action.u.self_prot.action_code;
 641         ie_len = elems.peering_len;
 642         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 643             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 644             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 645                                                         && ie_len != 8)) {
 646                 mpl_dbg(sdata,
 647                         "Mesh plink: incorrect plink ie length %d %d\n",
 648                         ftype, ie_len);
 649                 return;
 650         }
 651
 652         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 653                                 (!elems.mesh_id || !elems.mesh_config)) {
 654                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
 655                 return;
 656         }
 657         /* Note the lines below are correct, the llid in the frame is the plid
 658          * from the point of view of this host.
 659          */
 660         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 661         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 662             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 663                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 664
 665         /* WARNING: Only for sta pointer, is dropped & re-acquired */
 666         rcu_read_lock();
 667
 668         sta = sta_info_get(sdata, mgmt->sa);
 669         if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 670                 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 671                 rcu_read_unlock();
 672                 return;
 673         }
 674
 675         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 676             !rssi_threshold_check(sta, sdata)) {
 677                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
 678                         mgmt->sa);
 679                 rcu_read_unlock();
 680                 return;
 681         }
 682
 683         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 684                 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
 685                 rcu_read_unlock();
 686                 return;
 687         }
 688
 689         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 690                 rcu_read_unlock();
 691                 return;
 692         }
 693
 694         /* Now we will figure out the appropriate event... */
 695         event = PLINK_UNDEFINED;
 696         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 697             !mesh_matches_local(sdata, &elems)) {
 698                 matches_local = false;
 699                 switch (ftype) {
 700                 case WLAN_SP_MESH_PEERING_OPEN:
 701                         event = OPN_RJCT;
 702                         break;
 703                 case WLAN_SP_MESH_PEERING_CONFIRM:
 704                         event = CNF_RJCT;
 705                         break;
 706                 default:
 707                         break;
 708                 }
 709         }
 710
 711         if (!sta && !matches_local) {
 712                 rcu_read_unlock();
 713                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 714                 llid = 0;
 715                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 716                                     mgmt->sa, llid, plid, reason);
 717                 return;
 718         } else if (!sta) {
 719                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 720                 if (!mesh_plink_free_count(sdata)) {
 721                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 722                         rcu_read_unlock();
 723                         return;
 724                 }
 725                 event = OPN_ACPT;
 726         } else if (matches_local) {
 727                 switch (ftype) {
 728                 case WLAN_SP_MESH_PEERING_OPEN:
 729                         if (!mesh_plink_free_count(sdata) ||
 730                             (sta->plid && sta->plid != plid))
 731                                 event = OPN_IGNR;
 732                         else
 733                                 event = OPN_ACPT;
 734                         break;
 735                 case WLAN_SP_MESH_PEERING_CONFIRM:
 736                         if (!mesh_plink_free_count(sdata) ||
 737                             (sta->llid != llid || sta->plid != plid))
 738                                 event = CNF_IGNR;
 739                         else
 740                                 event = CNF_ACPT;
 741                         break;
 742                 case WLAN_SP_MESH_PEERING_CLOSE:
 743                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 744                                 /* Do not check for llid or plid. This does not
 745                                  * follow the standard but since multiple plinks
 746                                  * per sta are not supported, it is necessary in
 747                                  * order to avoid a livelock when MP A sees an
 748                                  * establish peer link to MP B but MP B does not
 749                                  * see it. This can be caused by a timeout in
 750                                  * B's peer link establishment or B beign
 751                                  * restarted.
 752                                  */
 753                                 event = CLS_ACPT;
 754                         else if (sta->plid != plid)
 755                                 event = CLS_IGNR;
 756                         else if (ie_len == 7 && sta->llid != llid)
 757                                 event = CLS_IGNR;
 758                         else
 759                                 event = CLS_ACPT;
 760                         break;
 761                 default:
 762                         mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
 763                         rcu_read_unlock();
 764                         return;
 765                 }
 766         }
 767
 768         if (event == OPN_ACPT) {
 769                 rcu_read_unlock();
 770                 /* allocate sta entry if necessary and update info */
 771                 sta = mesh_sta_info_get(sdata, mgmt->sa, &elems);
 772                 if (!sta) {
 773                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
 774                         rcu_read_unlock();
 775                         return;
 776                 }
 777         }
 778
 779         mpl_dbg(sdata,
 780                 "Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 781                 mgmt->sa, mplstates[sta->plink_state],
 782                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 783                 event);
 784         reason = 0;
 785         spin_lock_bh(&sta->lock);
 786         switch (sta->plink_state) {
 787                 /* spin_unlock as soon as state is updated at each case */
 788         case NL80211_PLINK_LISTEN:
 789                 switch (event) {
 790                 case CLS_ACPT:
 791                         mesh_plink_fsm_restart(sta);
 792                         spin_unlock_bh(&sta->lock);
 793                         break;
 794                 case OPN_ACPT:
 795                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 796                         sta->plid = plid;
 797                         get_random_bytes(&llid, 2);
 798                         sta->llid = llid;
 799                         mesh_plink_timer_set(sta,
 800                                              mshcfg->dot11MeshRetryTimeout);
 801                         spin_unlock_bh(&sta->lock);
 802                         mesh_plink_frame_tx(sdata,
 803                                             WLAN_SP_MESH_PEERING_OPEN,
 804                                             sta->sta.addr, llid, 0, 0);
 805                         mesh_plink_frame_tx(sdata,
 806                                             WLAN_SP_MESH_PEERING_CONFIRM,
 807                                             sta->sta.addr, llid, plid, 0);
 808                         break;
 809                 default:
 810                         spin_unlock_bh(&sta->lock);
 811                         break;
 812                 }
 813                 break;
 814
 815         case NL80211_PLINK_OPN_SNT:
 816                 switch (event) {
 817                 case OPN_RJCT:
 818                 case CNF_RJCT:
 819                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 820                 case CLS_ACPT:
 821                         if (!reason)
 822                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 823                         sta->reason = reason;
 824                         sta->plink_state = NL80211_PLINK_HOLDING;
 825                         if (!mod_plink_timer(sta,
 826                                              mshcfg->dot11MeshHoldingTimeout))
 827                                 sta->ignore_plink_timer = true;
 828
 829                         llid = sta->llid;
 830                         spin_unlock_bh(&sta->lock);
 831                         mesh_plink_frame_tx(sdata,
 832                                             WLAN_SP_MESH_PEERING_CLOSE,
 833                                             sta->sta.addr, llid, plid, reason);
 834                         break;
 835                 case OPN_ACPT:
 836                         /* retry timer is left untouched */
 837                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 838                         sta->plid = plid;
 839                         llid = sta->llid;
 840                         spin_unlock_bh(&sta->lock);
 841                         mesh_plink_frame_tx(sdata,
 842                                             WLAN_SP_MESH_PEERING_CONFIRM,
 843                                             sta->sta.addr, llid, plid, 0);
 844                         break;
 845                 case CNF_ACPT:
 846                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 847                         if (!mod_plink_timer(sta,
 848                                              mshcfg->dot11MeshConfirmTimeout))
 849                                 sta->ignore_plink_timer = true;
 850
 851                         spin_unlock_bh(&sta->lock);
 852                         break;
 853                 default:
 854                         spin_unlock_bh(&sta->lock);
 855                         break;
 856                 }
 857                 break;
 858
 859         case NL80211_PLINK_OPN_RCVD:
 860                 switch (event) {
 861                 case OPN_RJCT:
 862                 case CNF_RJCT:
 863                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 864                 case CLS_ACPT:
 865                         if (!reason)
 866                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 867                         sta->reason = reason;
 868                         sta->plink_state = NL80211_PLINK_HOLDING;
 869                         if (!mod_plink_timer(sta,
 870                                              mshcfg->dot11MeshHoldingTimeout))
 871                                 sta->ignore_plink_timer = true;
 872
 873                         llid = sta->llid;
 874                         spin_unlock_bh(&sta->lock);
 875                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 876                                             sta->sta.addr, llid, plid, reason);
 877                         break;
 878                 case OPN_ACPT:
 879                         llid = sta->llid;
 880                         spin_unlock_bh(&sta->lock);
 881                         mesh_plink_frame_tx(sdata,
 882                                             WLAN_SP_MESH_PEERING_CONFIRM,
 883                                             sta->sta.addr, llid, plid, 0);
 884                         break;
 885                 case CNF_ACPT:
 886                         del_timer(&sta->plink_timer);
 887                         sta->plink_state = NL80211_PLINK_ESTAB;
 888                         spin_unlock_bh(&sta->lock);
 889                         changed |= mesh_plink_inc_estab_count(sdata);
 890                         changed |= mesh_set_ht_prot_mode(sdata);
 891                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 892                                 sta->sta.addr);
 893                         break;
 894                 default:
 895                         spin_unlock_bh(&sta->lock);
 896                         break;
 897                 }
 898                 break;
 899
 900         case NL80211_PLINK_CNF_RCVD:
 901                 switch (event) {
 902                 case OPN_RJCT:
 903                 case CNF_RJCT:
 904                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 905                 case CLS_ACPT:
 906                         if (!reason)
 907                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 908                         sta->reason = reason;
 909                         sta->plink_state = NL80211_PLINK_HOLDING;
 910                         if (!mod_plink_timer(sta,
 911                                              mshcfg->dot11MeshHoldingTimeout))
 912                                 sta->ignore_plink_timer = true;
 913
 914                         llid = sta->llid;
 915                         spin_unlock_bh(&sta->lock);
 916                         mesh_plink_frame_tx(sdata,
 917                                             WLAN_SP_MESH_PEERING_CLOSE,
 918                                             sta->sta.addr, llid, plid, reason);
 919                         break;
 920                 case OPN_ACPT:
 921                         del_timer(&sta->plink_timer);
 922                         sta->plink_state = NL80211_PLINK_ESTAB;
 923                         spin_unlock_bh(&sta->lock);
 924                         changed |= mesh_plink_inc_estab_count(sdata);
 925                         changed |= mesh_set_ht_prot_mode(sdata);
 926                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 927                                 sta->sta.addr);
 928                         mesh_plink_frame_tx(sdata,
 929                                             WLAN_SP_MESH_PEERING_CONFIRM,
 930                                             sta->sta.addr, llid, plid, 0);
 931                         break;
 932                 default:
 933                         spin_unlock_bh(&sta->lock);
 934                         break;
 935                 }
 936                 break;
 937
 938         case NL80211_PLINK_ESTAB:
 939                 switch (event) {
 940                 case CLS_ACPT:
 941                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 942                         sta->reason = reason;
 943                         changed |= __mesh_plink_deactivate(sta);
 944                         sta->plink_state = NL80211_PLINK_HOLDING;
 945                         llid = sta->llid;
 946                         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 947                         spin_unlock_bh(&sta->lock);
 948                         changed |= mesh_set_ht_prot_mode(sdata);
 949                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 950                                             sta->sta.addr, llid, plid, reason);
 951                         break;
 952                 case OPN_ACPT:
 953                         llid = sta->llid;
 954                         spin_unlock_bh(&sta->lock);
 955                         mesh_plink_frame_tx(sdata,
 956                                             WLAN_SP_MESH_PEERING_CONFIRM,
 957                                             sta->sta.addr, llid, plid, 0);
 958                         break;
 959                 default:
 960                         spin_unlock_bh(&sta->lock);
 961                         break;
 962                 }
 963                 break;
 964         case NL80211_PLINK_HOLDING:
 965                 switch (event) {
 966                 case CLS_ACPT:
 967                         if (del_timer(&sta->plink_timer))
 968                                 sta->ignore_plink_timer = 1;
 969                         mesh_plink_fsm_restart(sta);
 970                         spin_unlock_bh(&sta->lock);
 971                         break;
 972                 case OPN_ACPT:
 973                 case CNF_ACPT:
 974                 case OPN_RJCT:
 975                 case CNF_RJCT:
 976                         llid = sta->llid;
 977                         reason = sta->reason;
 978                         spin_unlock_bh(&sta->lock);
 979                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 980                                             sta->sta.addr, llid, plid, reason);
 981                         break;
 982                 default:
 983                         spin_unlock_bh(&sta->lock);
 984                 }
 985                 break;
 986         default:
 987                 /* should not get here, PLINK_BLOCKED is dealt with at the
 988                  * beginning of the function
 989                  */
 990                 spin_unlock_bh(&sta->lock);
 991                 break;
 992         }
 993
 994         rcu_read_unlock();
 995
 996         if (changed)
 997                 ieee80211_bss_info_change_notify(sdata, changed);
 998 }