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 <linux/rculist.h>
  13
  14 #include "ieee80211_i.h"
  15 #include "rate.h"
  16 #include "mesh.h"
  17
  18 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
  19 #define PLINK_GET_LLID(p) (p + 2)
  20 #define PLINK_GET_PLID(p) (p + 4)
  21
  22 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
  23                                 jiffies + msecs_to_jiffies(t)))
  24
  25 enum plink_event {
  26         PLINK_UNDEFINED,
  27         OPN_ACPT,
  28         OPN_RJCT,
  29         OPN_IGNR,
  30         CNF_ACPT,
  31         CNF_RJCT,
  32         CNF_IGNR,
  33         CLS_ACPT,
  34         CLS_IGNR
  35 };
  36
  37 static const char * const mplstates[] = {
  38         [NL80211_PLINK_LISTEN] = "LISTEN",
  39         [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
  40         [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
  41         [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
  42         [NL80211_PLINK_ESTAB] = "ESTAB",
  43         [NL80211_PLINK_HOLDING] = "HOLDING",
  44         [NL80211_PLINK_BLOCKED] = "BLOCKED"
  45 };
  46
  47 static const char * const mplevents[] = {
  48         [PLINK_UNDEFINED] = "NONE",
  49         [OPN_ACPT] = "OPN_ACPT",
  50         [OPN_RJCT] = "OPN_RJCT",
  51         [OPN_IGNR] = "OPN_IGNR",
  52         [CNF_ACPT] = "CNF_ACPT",
  53         [CNF_RJCT] = "CNF_RJCT",
  54         [CNF_IGNR] = "CNF_IGNR",
  55         [CLS_ACPT] = "CLS_ACPT",
  56         [CLS_IGNR] = "CLS_IGNR"
  57 };
  58
  59 /* We only need a valid sta if user configured a minimum rssi_threshold. */
  60 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
  61                                  struct sta_info *sta)
  62 {
  63         s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
  64         return rssi_threshold == 0 ||
  65                (sta &&
  66                 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) >
  67                                                 rssi_threshold);
  68 }
  69
  70 /**
  71  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  72  *
  73  * @sta: mesh peer link to restart
  74  *
  75  * Locking: this function must be called holding sta->mesh->plink_lock
  76  */
  77 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  78 {
  79         lockdep_assert_held(&sta->mesh->plink_lock);
  80         sta->mesh->plink_state = NL80211_PLINK_LISTEN;
  81         sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
  82         sta->mesh->plink_retries = 0;
  83 }
  84
  85 /*
  86  * mesh_set_short_slot_time - enable / disable ERP short slot time.
  87  *
  88  * The standard indirectly mandates mesh STAs to turn off short slot time by
  89  * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
  90  * can't be sneaky about it. Enable short slot time if all mesh STAs in the
  91  * MBSS support ERP rates.
  92  *
  93  * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
  94  */
  95 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
  96 {
  97         struct ieee80211_local *local = sdata->local;
  98         struct ieee80211_supported_band *sband;
  99         struct sta_info *sta;
 100         u32 erp_rates = 0, changed = 0;
 101         int i;
 102         bool short_slot = false;
 103
 104         sband = ieee80211_get_sband(sdata);
 105         if (!sband)
 106                 return changed;
 107
 108         if (sband->band == NL80211_BAND_5GHZ) {
 109                 /* (IEEE 802.11-2012 19.4.5) */
 110                 short_slot = true;
 111                 goto out;
 112         } else if (sband->band != NL80211_BAND_2GHZ) {
 113                 goto out;
 114         }
 115
 116         for (i = 0; i < sband->n_bitrates; i++)
 117                 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
 118                         erp_rates |= BIT(i);
 119
 120         if (!erp_rates)
 121                 goto out;
 122
 123         rcu_read_lock();
 124         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 125                 if (sdata != sta->sdata ||
 126                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 127                         continue;
 128
 129                 short_slot = false;
 130                 if (erp_rates & sta->sta.supp_rates[sband->band])
 131                         short_slot = true;
 132                  else
 133                         break;
 134         }
 135         rcu_read_unlock();
 136
 137 out:
 138         if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 139                 sdata->vif.bss_conf.use_short_slot = short_slot;
 140                 changed = BSS_CHANGED_ERP_SLOT;
 141                 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 142                         sdata->vif.addr, short_slot);
 143         }
 144         return changed;
 145 }
 146
 147 /**
 148  * mesh_set_ht_prot_mode - set correct HT protection mode
 149  *
 150  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 151  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 152  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 153  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 154  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 155  * HT20 peer is present. Otherwise no-protection mode is selected.
 156  */
 157 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 158 {
 159         struct ieee80211_local *local = sdata->local;
 160         struct sta_info *sta;
 161         u16 ht_opmode;
 162         bool non_ht_sta = false, ht20_sta = false;
 163
 164         switch (sdata->vif.bss_conf.chandef.width) {
 165         case NL80211_CHAN_WIDTH_20_NOHT:
 166         case NL80211_CHAN_WIDTH_5:
 167         case NL80211_CHAN_WIDTH_10:
 168                 return 0;
 169         default:
 170                 break;
 171         }
 172
 173         rcu_read_lock();
 174         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 175                 if (sdata != sta->sdata ||
 176                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 177                         continue;
 178
 179                 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
 180                         continue;
 181
 182                 if (!sta->sta.ht_cap.ht_supported) {
 183                         mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
 184                                        sta->sta.addr);
 185                         non_ht_sta = true;
 186                         break;
 187                 }
 188
 189                 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
 190                 ht20_sta = true;
 191         }
 192         rcu_read_unlock();
 193
 194         if (non_ht_sta)
 195                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 196         else if (ht20_sta &&
 197                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 198                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 199         else
 200                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 201
 202         if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
 203                 return 0;
 204
 205         sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 206         sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 207         mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
 208         return BSS_CHANGED_HT;
 209 }
 210
 211 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 212                                struct sta_info *sta,
 213                                enum ieee80211_self_protected_actioncode action,
 214                                u8 *da, u16 llid, u16 plid, u16 reason)
 215 {
 216         struct ieee80211_local *local = sdata->local;
 217         struct sk_buff *skb;
 218         struct ieee80211_tx_info *info;
 219         struct ieee80211_mgmt *mgmt;
 220         bool include_plid = false;
 221         u16 peering_proto = 0;
 222         u8 *pos, ie_len = 4;
 223         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 224                       sizeof(mgmt->u.action.u.self_prot);
 225         int err = -ENOMEM;
 226
 227         skb = dev_alloc_skb(local->tx_headroom +
 228                             hdr_len +
 229                             2 + /* capability info */
 230                             2 + /* AID */
 231                             2 + 8 + /* supported rates */
 232                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 233                             2 + sdata->u.mesh.mesh_id_len +
 234                             2 + sizeof(struct ieee80211_meshconf_ie) +
 235                             2 + sizeof(struct ieee80211_ht_cap) +
 236                             2 + sizeof(struct ieee80211_ht_operation) +
 237                             2 + sizeof(struct ieee80211_vht_cap) +
 238                             2 + sizeof(struct ieee80211_vht_operation) +
 239                             2 + 8 + /* peering IE */
 240                             sdata->u.mesh.ie_len);
 241         if (!skb)
 242                 return err;
 243         info = IEEE80211_SKB_CB(skb);
 244         skb_reserve(skb, local->tx_headroom);
 245         mgmt = skb_put_zero(skb, 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                 struct ieee80211_supported_band *sband;
 256                 enum nl80211_band band;
 257
 258                 sband = ieee80211_get_sband(sdata);
 259                 if (!sband) {
 260                         err = -EINVAL;
 261                         goto free;
 262                 }
 263                 band = sband->band;
 264
 265                 /* capability info */
 266                 pos = skb_put_zero(skb, 2);
 267                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 268                         /* AID */
 269                         pos = skb_put(skb, 2);
 270                         put_unaligned_le16(sta->sta.aid, pos);
 271                 }
 272                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 273                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 274                     mesh_add_rsn_ie(sdata, skb) ||
 275                     mesh_add_meshid_ie(sdata, skb) ||
 276                     mesh_add_meshconf_ie(sdata, skb))
 277                         goto free;
 278         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 279                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 280                 if (mesh_add_meshid_ie(sdata, skb))
 281                         goto free;
 282         }
 283
 284         /* Add Mesh Peering Management element */
 285         switch (action) {
 286         case WLAN_SP_MESH_PEERING_OPEN:
 287                 break;
 288         case WLAN_SP_MESH_PEERING_CONFIRM:
 289                 ie_len += 2;
 290                 include_plid = true;
 291                 break;
 292         case WLAN_SP_MESH_PEERING_CLOSE:
 293                 if (plid) {
 294                         ie_len += 2;
 295                         include_plid = true;
 296                 }
 297                 ie_len += 2;    /* reason code */
 298                 break;
 299         default:
 300                 err = -EINVAL;
 301                 goto free;
 302         }
 303
 304         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 305                 goto free;
 306
 307         pos = skb_put(skb, 2 + ie_len);
 308         *pos++ = WLAN_EID_PEER_MGMT;
 309         *pos++ = ie_len;
 310         memcpy(pos, &peering_proto, 2);
 311         pos += 2;
 312         put_unaligned_le16(llid, pos);
 313         pos += 2;
 314         if (include_plid) {
 315                 put_unaligned_le16(plid, pos);
 316                 pos += 2;
 317         }
 318         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 319                 put_unaligned_le16(reason, pos);
 320                 pos += 2;
 321         }
 322
 323         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 324                 if (mesh_add_ht_cap_ie(sdata, skb) ||
 325                     mesh_add_ht_oper_ie(sdata, skb) ||
 326                     mesh_add_vht_cap_ie(sdata, skb) ||
 327                     mesh_add_vht_oper_ie(sdata, skb))
 328                         goto free;
 329         }
 330
 331         if (mesh_add_vendor_ies(sdata, skb))
 332                 goto free;
 333
 334         ieee80211_tx_skb(sdata, skb);
 335         return 0;
 336 free:
 337         kfree_skb(skb);
 338         return err;
 339 }
 340
 341 /**
 342  * __mesh_plink_deactivate - deactivate mesh peer link
 343  *
 344  * @sta: mesh peer link to deactivate
 345  *
 346  * Mesh paths with this peer as next hop should be flushed
 347  * by the caller outside of plink_lock.
 348  *
 349  * Returns beacon changed flag if the beacon content changed.
 350  *
 351  * Locking: the caller must hold sta->mesh->plink_lock
 352  */
 353 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 354 {
 355         struct ieee80211_sub_if_data *sdata = sta->sdata;
 356         u32 changed = 0;
 357
 358         lockdep_assert_held(&sta->mesh->plink_lock);
 359
 360         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 361                 changed = mesh_plink_dec_estab_count(sdata);
 362         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 363
 364         ieee80211_mps_sta_status_update(sta);
 365         changed |= ieee80211_mps_set_sta_local_pm(sta,
 366                         NL80211_MESH_POWER_UNKNOWN);
 367
 368         return changed;
 369 }
 370
 371 /**
 372  * mesh_plink_deactivate - deactivate mesh peer link
 373  *
 374  * @sta: mesh peer link to deactivate
 375  *
 376  * All mesh paths with this peer as next hop will be flushed
 377  */
 378 u32 mesh_plink_deactivate(struct sta_info *sta)
 379 {
 380         struct ieee80211_sub_if_data *sdata = sta->sdata;
 381         u32 changed;
 382
 383         spin_lock_bh(&sta->mesh->plink_lock);
 384         changed = __mesh_plink_deactivate(sta);
 385
 386         if (!sdata->u.mesh.user_mpm) {
 387                 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
 388                 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
 389                                     sta->sta.addr, sta->mesh->llid,
 390                                     sta->mesh->plid, sta->mesh->reason);
 391         }
 392         spin_unlock_bh(&sta->mesh->plink_lock);
 393         if (!sdata->u.mesh.user_mpm)
 394                 del_timer_sync(&sta->mesh->plink_timer);
 395         mesh_path_flush_by_nexthop(sta);
 396
 397         /* make sure no readers can access nexthop sta from here on */
 398         synchronize_net();
 399
 400         return changed;
 401 }
 402
 403 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 404                                struct sta_info *sta,
 405                                struct ieee802_11_elems *elems, bool insert)
 406 {
 407         struct ieee80211_local *local = sdata->local;
 408         struct ieee80211_supported_band *sband;
 409         u32 rates, basic_rates = 0, changed = 0;
 410         enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
 411
 412         sband = ieee80211_get_sband(sdata);
 413         if (!sband)
 414                 return;
 415
 416         rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
 417                                         &basic_rates);
 418
 419         spin_lock_bh(&sta->mesh->plink_lock);
 420         sta->rx_stats.last_rx = jiffies;
 421
 422         /* rates and capabilities don't change during peering */
 423         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
 424             sta->mesh->processed_beacon)
 425                 goto out;
 426         sta->mesh->processed_beacon = true;
 427
 428         if (sta->sta.supp_rates[sband->band] != rates)
 429                 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 430         sta->sta.supp_rates[sband->band] = rates;
 431
 432         if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 433                                               elems->ht_cap_elem, sta))
 434                 changed |= IEEE80211_RC_BW_CHANGED;
 435
 436         ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
 437                                             elems->vht_cap_elem, sta);
 438
 439         if (bw != sta->sta.bandwidth)
 440                 changed |= IEEE80211_RC_BW_CHANGED;
 441
 442         /* HT peer is operating 20MHz-only */
 443         if (elems->ht_operation &&
 444             !(elems->ht_operation->ht_param &
 445               IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 446                 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 447                         changed |= IEEE80211_RC_BW_CHANGED;
 448                 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 449         }
 450
 451         if (insert)
 452                 rate_control_rate_init(sta);
 453         else
 454                 rate_control_rate_update(local, sband, sta, changed);
 455 out:
 456         spin_unlock_bh(&sta->mesh->plink_lock);
 457 }
 458
 459 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
 460 {
 461         struct sta_info *sta;
 462         unsigned long *aid_map;
 463         int aid;
 464
 465         aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
 466                           sizeof(*aid_map), GFP_KERNEL);
 467         if (!aid_map)
 468                 return -ENOMEM;
 469
 470         /* reserve aid 0 for mcast indication */
 471         __set_bit(0, aid_map);
 472
 473         rcu_read_lock();
 474         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
 475                 __set_bit(sta->sta.aid, aid_map);
 476         rcu_read_unlock();
 477
 478         aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
 479         kfree(aid_map);
 480
 481         if (aid > IEEE80211_MAX_AID)
 482                 return -ENOBUFS;
 483
 484         return aid;
 485 }
 486
 487 static struct sta_info *
 488 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 489 {
 490         struct sta_info *sta;
 491         int aid;
 492
 493         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 494                 return NULL;
 495
 496         aid = mesh_allocate_aid(sdata);
 497         if (aid < 0)
 498                 return NULL;
 499
 500         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 501         if (!sta)
 502                 return NULL;
 503
 504         sta->mesh->plink_state = NL80211_PLINK_LISTEN;
 505         sta->sta.wme = true;
 506         sta->sta.aid = aid;
 507
 508         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 509         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 510         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 511
 512         return sta;
 513 }
 514
 515 static struct sta_info *
 516 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 517                     struct ieee802_11_elems *elems)
 518 {
 519         struct sta_info *sta = NULL;
 520
 521         /* Userspace handles station allocation */
 522         if (sdata->u.mesh.user_mpm ||
 523             sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
 524                 if (mesh_peer_accepts_plinks(elems) &&
 525                     mesh_plink_availables(sdata))
 526                         cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 527                                                            elems->ie_start,
 528                                                            elems->total_len,
 529                                                            GFP_KERNEL);
 530         } else
 531                 sta = __mesh_sta_info_alloc(sdata, addr);
 532
 533         return sta;
 534 }
 535
 536 /*
 537  * mesh_sta_info_get - return mesh sta info entry for @addr.
 538  *
 539  * @sdata: local meshif
 540  * @addr: peer's address
 541  * @elems: IEs from beacon or mesh peering frame.
 542  *
 543  * Return existing or newly allocated sta_info under RCU read lock.
 544  * (re)initialize with given IEs.
 545  */
 546 static struct sta_info *
 547 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 548                   u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 549 {
 550         struct sta_info *sta = NULL;
 551
 552         rcu_read_lock();
 553         sta = sta_info_get(sdata, addr);
 554         if (sta) {
 555                 mesh_sta_info_init(sdata, sta, elems, false);
 556         } else {
 557                 rcu_read_unlock();
 558                 /* can't run atomic */
 559                 sta = mesh_sta_info_alloc(sdata, addr, elems);
 560                 if (!sta) {
 561                         rcu_read_lock();
 562                         return NULL;
 563                 }
 564
 565                 mesh_sta_info_init(sdata, sta, elems, true);
 566
 567                 if (sta_info_insert_rcu(sta))
 568                         return NULL;
 569         }
 570
 571         return sta;
 572 }
 573
 574 /*
 575  * mesh_neighbour_update - update or initialize new mesh neighbor.
 576  *
 577  * @sdata: local meshif
 578  * @addr: peer's address
 579  * @elems: IEs from beacon or mesh peering frame
 580  *
 581  * Initiates peering if appropriate.
 582  */
 583 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 584                            u8 *hw_addr,
 585                            struct ieee802_11_elems *elems)
 586 {
 587         struct sta_info *sta;
 588         u32 changed = 0;
 589
 590         sta = mesh_sta_info_get(sdata, hw_addr, elems);
 591         if (!sta)
 592                 goto out;
 593
 594         if (mesh_peer_accepts_plinks(elems) &&
 595             sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
 596             sdata->u.mesh.accepting_plinks &&
 597             sdata->u.mesh.mshcfg.auto_open_plinks &&
 598             rssi_threshold_check(sdata, sta))
 599                 changed = mesh_plink_open(sta);
 600
 601         ieee80211_mps_frame_release(sta, elems);
 602 out:
 603         rcu_read_unlock();
 604         ieee80211_mbss_info_change_notify(sdata, changed);
 605 }
 606
 607 static void mesh_plink_timer(unsigned long data)
 608 {
 609         struct sta_info *sta;
 610         u16 reason = 0;
 611         struct ieee80211_sub_if_data *sdata;
 612         struct mesh_config *mshcfg;
 613         enum ieee80211_self_protected_actioncode action = 0;
 614
 615         /*
 616          * This STA is valid because sta_info_destroy() will
 617          * del_timer_sync() this timer after having made sure
 618          * it cannot be readded (by deleting the plink.)
 619          */
 620         sta = (struct sta_info *) data;
 621
 622         if (sta->sdata->local->quiescing)
 623                 return;
 624
 625         spin_lock_bh(&sta->mesh->plink_lock);
 626
 627         /* If a timer fires just before a state transition on another CPU,
 628          * we may have already extended the timeout and changed state by the
 629          * time we've acquired the lock and arrived  here.  In that case,
 630          * skip this timer and wait for the new one.
 631          */
 632         if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
 633                 mpl_dbg(sta->sdata,
 634                         "Ignoring timer for %pM in state %s (timer adjusted)",
 635                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 636                 spin_unlock_bh(&sta->mesh->plink_lock);
 637                 return;
 638         }
 639
 640         /* del_timer() and handler may race when entering these states */
 641         if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
 642             sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
 643                 mpl_dbg(sta->sdata,
 644                         "Ignoring timer for %pM in state %s (timer deleted)",
 645                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 646                 spin_unlock_bh(&sta->mesh->plink_lock);
 647                 return;
 648         }
 649
 650         mpl_dbg(sta->sdata,
 651                 "Mesh plink timer for %pM fired on state %s\n",
 652                 sta->sta.addr, mplstates[sta->mesh->plink_state]);
 653         sdata = sta->sdata;
 654         mshcfg = &sdata->u.mesh.mshcfg;
 655
 656         switch (sta->mesh->plink_state) {
 657         case NL80211_PLINK_OPN_RCVD:
 658         case NL80211_PLINK_OPN_SNT:
 659                 /* retry timer */
 660                 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
 661                         u32 rand;
 662                         mpl_dbg(sta->sdata,
 663                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 664                                 sta->sta.addr, sta->mesh->plink_retries,
 665                                 sta->mesh->plink_timeout);
 666                         get_random_bytes(&rand, sizeof(u32));
 667                         sta->mesh->plink_timeout = sta->mesh->plink_timeout +
 668                                              rand % sta->mesh->plink_timeout;
 669                         ++sta->mesh->plink_retries;
 670                         mod_plink_timer(sta, sta->mesh->plink_timeout);
 671                         action = WLAN_SP_MESH_PEERING_OPEN;
 672                         break;
 673                 }
 674                 reason = WLAN_REASON_MESH_MAX_RETRIES;
 675                 /* fall through on else */
 676         case NL80211_PLINK_CNF_RCVD:
 677                 /* confirm timer */
 678                 if (!reason)
 679                         reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
 680                 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 681                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 682                 action = WLAN_SP_MESH_PEERING_CLOSE;
 683                 break;
 684         case NL80211_PLINK_HOLDING:
 685                 /* holding timer */
 686                 del_timer(&sta->mesh->plink_timer);
 687                 mesh_plink_fsm_restart(sta);
 688                 break;
 689         default:
 690                 break;
 691         }
 692         spin_unlock_bh(&sta->mesh->plink_lock);
 693         if (action)
 694                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 695                                     sta->mesh->llid, sta->mesh->plid, reason);
 696 }
 697
 698 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
 699 {
 700         sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
 701         sta->mesh->plink_timer.data = (unsigned long) sta;
 702         sta->mesh->plink_timer.function = mesh_plink_timer;
 703         sta->mesh->plink_timeout = timeout;
 704         add_timer(&sta->mesh->plink_timer);
 705 }
 706
 707 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
 708                         u16 llid)
 709 {
 710         struct ieee80211_local *local = sdata->local;
 711         bool in_use = false;
 712         struct sta_info *sta;
 713
 714         rcu_read_lock();
 715         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 716                 if (sdata != sta->sdata)
 717                         continue;
 718
 719                 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
 720                         in_use = true;
 721                         break;
 722                 }
 723         }
 724         rcu_read_unlock();
 725
 726         return in_use;
 727 }
 728
 729 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
 730 {
 731         u16 llid;
 732
 733         do {
 734                 get_random_bytes(&llid, sizeof(llid));
 735         } while (llid_in_use(sdata, llid));
 736
 737         return llid;
 738 }
 739
 740 u32 mesh_plink_open(struct sta_info *sta)
 741 {
 742         struct ieee80211_sub_if_data *sdata = sta->sdata;
 743         u32 changed;
 744
 745         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 746                 return 0;
 747
 748         spin_lock_bh(&sta->mesh->plink_lock);
 749         sta->mesh->llid = mesh_get_new_llid(sdata);
 750         if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
 751             sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
 752                 spin_unlock_bh(&sta->mesh->plink_lock);
 753                 return 0;
 754         }
 755         sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
 756         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 757         spin_unlock_bh(&sta->mesh->plink_lock);
 758         mpl_dbg(sdata,
 759                 "Mesh plink: starting establishment with %pM\n",
 760                 sta->sta.addr);
 761
 762         /* set the non-peer mode to active during peering */
 763         changed = ieee80211_mps_local_status_update(sdata);
 764
 765         mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
 766                             sta->sta.addr, sta->mesh->llid, 0, 0);
 767         return changed;
 768 }
 769
 770 u32 mesh_plink_block(struct sta_info *sta)
 771 {
 772         u32 changed;
 773
 774         spin_lock_bh(&sta->mesh->plink_lock);
 775         changed = __mesh_plink_deactivate(sta);
 776         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 777         spin_unlock_bh(&sta->mesh->plink_lock);
 778         mesh_path_flush_by_nexthop(sta);
 779
 780         return changed;
 781 }
 782
 783 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
 784                              struct sta_info *sta,
 785                              enum plink_event event)
 786 {
 787         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 788         u16 reason = (event == CLS_ACPT) ?
 789                      WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
 790
 791         sta->mesh->reason = reason;
 792         sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 793         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 794 }
 795
 796 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
 797                                 struct sta_info *sta)
 798 {
 799         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 800         u32 changed = 0;
 801
 802         del_timer(&sta->mesh->plink_timer);
 803         sta->mesh->plink_state = NL80211_PLINK_ESTAB;
 804         changed |= mesh_plink_inc_estab_count(sdata);
 805         changed |= mesh_set_ht_prot_mode(sdata);
 806         changed |= mesh_set_short_slot_time(sdata);
 807         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
 808         ieee80211_mps_sta_status_update(sta);
 809         changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
 810         return changed;
 811 }
 812
 813 /**
 814  * mesh_plink_fsm - step @sta MPM based on @event
 815  *
 816  * @sdata: interface
 817  * @sta: mesh neighbor
 818  * @event: peering event
 819  *
 820  * Return: changed MBSS flags
 821  */
 822 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
 823                           struct sta_info *sta, enum plink_event event)
 824 {
 825         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 826         enum ieee80211_self_protected_actioncode action = 0;
 827         u32 changed = 0;
 828         bool flush = false;
 829
 830         mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
 831                 mplstates[sta->mesh->plink_state], mplevents[event]);
 832
 833         spin_lock_bh(&sta->mesh->plink_lock);
 834         switch (sta->mesh->plink_state) {
 835         case NL80211_PLINK_LISTEN:
 836                 switch (event) {
 837                 case CLS_ACPT:
 838                         mesh_plink_fsm_restart(sta);
 839                         break;
 840                 case OPN_ACPT:
 841                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 842                         sta->mesh->llid = mesh_get_new_llid(sdata);
 843                         mesh_plink_timer_set(sta,
 844                                              mshcfg->dot11MeshRetryTimeout);
 845
 846                         /* set the non-peer mode to active during peering */
 847                         changed |= ieee80211_mps_local_status_update(sdata);
 848                         action = WLAN_SP_MESH_PEERING_OPEN;
 849                         break;
 850                 default:
 851                         break;
 852                 }
 853                 break;
 854         case NL80211_PLINK_OPN_SNT:
 855                 switch (event) {
 856                 case OPN_RJCT:
 857                 case CNF_RJCT:
 858                 case CLS_ACPT:
 859                         mesh_plink_close(sdata, sta, event);
 860                         action = WLAN_SP_MESH_PEERING_CLOSE;
 861                         break;
 862                 case OPN_ACPT:
 863                         /* retry timer is left untouched */
 864                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 865                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 866                         break;
 867                 case CNF_ACPT:
 868                         sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
 869                         mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
 870                         break;
 871                 default:
 872                         break;
 873                 }
 874                 break;
 875         case NL80211_PLINK_OPN_RCVD:
 876                 switch (event) {
 877                 case OPN_RJCT:
 878                 case CNF_RJCT:
 879                 case CLS_ACPT:
 880                         mesh_plink_close(sdata, sta, event);
 881                         action = WLAN_SP_MESH_PEERING_CLOSE;
 882                         break;
 883                 case OPN_ACPT:
 884                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 885                         break;
 886                 case CNF_ACPT:
 887                         changed |= mesh_plink_establish(sdata, sta);
 888                         break;
 889                 default:
 890                         break;
 891                 }
 892                 break;
 893         case NL80211_PLINK_CNF_RCVD:
 894                 switch (event) {
 895                 case OPN_RJCT:
 896                 case CNF_RJCT:
 897                 case CLS_ACPT:
 898                         mesh_plink_close(sdata, sta, event);
 899                         action = WLAN_SP_MESH_PEERING_CLOSE;
 900                         break;
 901                 case OPN_ACPT:
 902                         changed |= mesh_plink_establish(sdata, sta);
 903                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 904                         break;
 905                 default:
 906                         break;
 907                 }
 908                 break;
 909         case NL80211_PLINK_ESTAB:
 910                 switch (event) {
 911                 case CLS_ACPT:
 912                         changed |= __mesh_plink_deactivate(sta);
 913                         changed |= mesh_set_ht_prot_mode(sdata);
 914                         changed |= mesh_set_short_slot_time(sdata);
 915                         mesh_plink_close(sdata, sta, event);
 916                         action = WLAN_SP_MESH_PEERING_CLOSE;
 917                         flush = true;
 918                         break;
 919                 case OPN_ACPT:
 920                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 921                         break;
 922                 default:
 923                         break;
 924                 }
 925                 break;
 926         case NL80211_PLINK_HOLDING:
 927                 switch (event) {
 928                 case CLS_ACPT:
 929                         del_timer(&sta->mesh->plink_timer);
 930                         mesh_plink_fsm_restart(sta);
 931                         break;
 932                 case OPN_ACPT:
 933                 case CNF_ACPT:
 934                 case OPN_RJCT:
 935                 case CNF_RJCT:
 936                         action = WLAN_SP_MESH_PEERING_CLOSE;
 937                         break;
 938                 default:
 939                         break;
 940                 }
 941                 break;
 942         default:
 943                 /* should not get here, PLINK_BLOCKED is dealt with at the
 944                  * beginning of the function
 945                  */
 946                 break;
 947         }
 948         spin_unlock_bh(&sta->mesh->plink_lock);
 949         if (flush)
 950                 mesh_path_flush_by_nexthop(sta);
 951         if (action) {
 952                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 953                                     sta->mesh->llid, sta->mesh->plid,
 954                                     sta->mesh->reason);
 955
 956                 /* also send confirm in open case */
 957                 if (action == WLAN_SP_MESH_PEERING_OPEN) {
 958                         mesh_plink_frame_tx(sdata, sta,
 959                                             WLAN_SP_MESH_PEERING_CONFIRM,
 960                                             sta->sta.addr, sta->mesh->llid,
 961                                             sta->mesh->plid, 0);
 962                 }
 963         }
 964
 965         return changed;
 966 }
 967
 968 /*
 969  * mesh_plink_get_event - get correct MPM event
 970  *
 971  * @sdata: interface
 972  * @sta: peer, leave NULL if processing a frame from a new suitable peer
 973  * @elems: peering management IEs
 974  * @ftype: frame type
 975  * @llid: peer's peer link ID
 976  * @plid: peer's local link ID
 977  *
 978  * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
 979  * an error.
 980  */
 981 static enum plink_event
 982 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
 983                      struct sta_info *sta,
 984                      struct ieee802_11_elems *elems,
 985                      enum ieee80211_self_protected_actioncode ftype,
 986                      u16 llid, u16 plid)
 987 {
 988         enum plink_event event = PLINK_UNDEFINED;
 989         u8 ie_len = elems->peering_len;
 990         bool matches_local;
 991
 992         matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
 993                          mesh_matches_local(sdata, elems));
 994
 995         /* deny open request from non-matching peer */
 996         if (!matches_local && !sta) {
 997                 event = OPN_RJCT;
 998                 goto out;
 999         }
1000
1001         if (!sta) {
1002                 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1003                         mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1004                         goto out;
1005                 }
1006                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1007                 if (!mesh_plink_free_count(sdata)) {
1008                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1009                         goto out;
1010                 }
1011
1012                 /* new matching peer */
1013                 event = OPN_ACPT;
1014                 goto out;
1015         } else {
1016                 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1017                         mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1018                         goto out;
1019                 }
1020                 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1021                         goto out;
1022         }
1023
1024         switch (ftype) {
1025         case WLAN_SP_MESH_PEERING_OPEN:
1026                 if (!matches_local)
1027                         event = OPN_RJCT;
1028                 if (!mesh_plink_free_count(sdata) ||
1029                     (sta->mesh->plid && sta->mesh->plid != plid))
1030                         event = OPN_IGNR;
1031                 else
1032                         event = OPN_ACPT;
1033                 break;
1034         case WLAN_SP_MESH_PEERING_CONFIRM:
1035                 if (!matches_local)
1036                         event = CNF_RJCT;
1037                 if (!mesh_plink_free_count(sdata) ||
1038                     sta->mesh->llid != llid ||
1039                     (sta->mesh->plid && sta->mesh->plid != plid))
1040                         event = CNF_IGNR;
1041                 else
1042                         event = CNF_ACPT;
1043                 break;
1044         case WLAN_SP_MESH_PEERING_CLOSE:
1045                 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1046                         /* Do not check for llid or plid. This does not
1047                          * follow the standard but since multiple plinks
1048                          * per sta are not supported, it is necessary in
1049                          * order to avoid a livelock when MP A sees an
1050                          * establish peer link to MP B but MP B does not
1051                          * see it. This can be caused by a timeout in
1052                          * B's peer link establishment or B beign
1053                          * restarted.
1054                          */
1055                         event = CLS_ACPT;
1056                 else if (sta->mesh->plid != plid)
1057                         event = CLS_IGNR;
1058                 else if (ie_len == 8 && sta->mesh->llid != llid)
1059                         event = CLS_IGNR;
1060                 else
1061                         event = CLS_ACPT;
1062                 break;
1063         default:
1064                 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1065                 break;
1066         }
1067
1068 out:
1069         return event;
1070 }
1071
1072 static void
1073 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1074                          struct ieee80211_mgmt *mgmt,
1075                          struct ieee802_11_elems *elems)
1076 {
1077
1078         struct sta_info *sta;
1079         enum plink_event event;
1080         enum ieee80211_self_protected_actioncode ftype;
1081         u32 changed = 0;
1082         u8 ie_len = elems->peering_len;
1083         u16 plid, llid = 0;
1084
1085         if (!elems->peering) {
1086                 mpl_dbg(sdata,
1087                         "Mesh plink: missing necessary peer link ie\n");
1088                 return;
1089         }
1090
1091         if (elems->rsn_len &&
1092             sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1093                 mpl_dbg(sdata,
1094                         "Mesh plink: can't establish link with secure peer\n");
1095                 return;
1096         }
1097
1098         ftype = mgmt->u.action.u.self_prot.action_code;
1099         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1100             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1101             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1102                                                         && ie_len != 8)) {
1103                 mpl_dbg(sdata,
1104                         "Mesh plink: incorrect plink ie length %d %d\n",
1105                         ftype, ie_len);
1106                 return;
1107         }
1108
1109         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1110             (!elems->mesh_id || !elems->mesh_config)) {
1111                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1112                 return;
1113         }
1114         /* Note the lines below are correct, the llid in the frame is the plid
1115          * from the point of view of this host.
1116          */
1117         plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1118         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1119             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1120                 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1121
1122         /* WARNING: Only for sta pointer, is dropped & re-acquired */
1123         rcu_read_lock();
1124
1125         sta = sta_info_get(sdata, mgmt->sa);
1126
1127         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1128             !rssi_threshold_check(sdata, sta)) {
1129                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1130                         mgmt->sa);
1131                 goto unlock_rcu;
1132         }
1133
1134         /* Now we will figure out the appropriate event... */
1135         event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1136
1137         if (event == OPN_ACPT) {
1138                 rcu_read_unlock();
1139                 /* allocate sta entry if necessary and update info */
1140                 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1141                 if (!sta) {
1142                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1143                         goto unlock_rcu;
1144                 }
1145                 sta->mesh->plid = plid;
1146         } else if (!sta && event == OPN_RJCT) {
1147                 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1148                                     mgmt->sa, 0, plid,
1149                                     WLAN_REASON_MESH_CONFIG);
1150                 goto unlock_rcu;
1151         } else if (!sta || event == PLINK_UNDEFINED) {
1152                 /* something went wrong */
1153                 goto unlock_rcu;
1154         }
1155
1156         if (event == CNF_ACPT) {
1157                 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1158                 if (!sta->mesh->plid)
1159                         sta->mesh->plid = plid;
1160
1161                 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1162         }
1163
1164         changed |= mesh_plink_fsm(sdata, sta, event);
1165
1166 unlock_rcu:
1167         rcu_read_unlock();
1168
1169         if (changed)
1170                 ieee80211_mbss_info_change_notify(sdata, changed);
1171 }
1172
1173 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1174                          struct ieee80211_mgmt *mgmt, size_t len,
1175                          struct ieee80211_rx_status *rx_status)
1176 {
1177         struct ieee802_11_elems elems;
1178         size_t baselen;
1179         u8 *baseaddr;
1180
1181         /* need action_code, aux */
1182         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1183                 return;
1184
1185         if (sdata->u.mesh.user_mpm)
1186                 /* userspace must register for these */
1187                 return;
1188
1189         if (is_multicast_ether_addr(mgmt->da)) {
1190                 mpl_dbg(sdata,
1191                         "Mesh plink: ignore frame from multicast address\n");
1192                 return;
1193         }
1194
1195         baseaddr = mgmt->u.action.u.self_prot.variable;
1196         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1197         if (mgmt->u.action.u.self_prot.action_code ==
1198                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
1199                 baseaddr += 4;
1200                 baselen += 4;
1201
1202                 if (baselen > len)
1203                         return;
1204         }
1205         ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1206         mesh_process_plink_frame(sdata, mgmt, &elems);
1207 }