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_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
  17 #define PLINK_GET_LLID(p) (p + 2)
  18 #define PLINK_GET_PLID(p) (p + 4)
  19
  20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
  21                                 jiffies + msecs_to_jiffies(t)))
  22
  23 enum plink_event {
  24         PLINK_UNDEFINED,
  25         OPN_ACPT,
  26         OPN_RJCT,
  27         OPN_IGNR,
  28         CNF_ACPT,
  29         CNF_RJCT,
  30         CNF_IGNR,
  31         CLS_ACPT,
  32         CLS_IGNR
  33 };
  34
  35 static const char * const mplstates[] = {
  36         [NL80211_PLINK_LISTEN] = "LISTEN",
  37         [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
  38         [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
  39         [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
  40         [NL80211_PLINK_ESTAB] = "ESTAB",
  41         [NL80211_PLINK_HOLDING] = "HOLDING",
  42         [NL80211_PLINK_BLOCKED] = "BLOCKED"
  43 };
  44
  45 static const char * const mplevents[] = {
  46         [PLINK_UNDEFINED] = "NONE",
  47         [OPN_ACPT] = "OPN_ACPT",
  48         [OPN_RJCT] = "OPN_RJCT",
  49         [OPN_IGNR] = "OPN_IGNR",
  50         [CNF_ACPT] = "CNF_ACPT",
  51         [CNF_RJCT] = "CNF_RJCT",
  52         [CNF_IGNR] = "CNF_IGNR",
  53         [CLS_ACPT] = "CLS_ACPT",
  54         [CLS_IGNR] = "CLS_IGNR"
  55 };
  56
  57 /* We only need a valid sta if user configured a minimum rssi_threshold. */
  58 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
  59                                  struct sta_info *sta)
  60 {
  61         s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
  62         return rssi_threshold == 0 ||
  63                (sta &&
  64                 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) >
  65                                                 rssi_threshold);
  66 }
  67
  68 /**
  69  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  70  *
  71  * @sta: mesh peer link to restart
  72  *
  73  * Locking: this function must be called holding sta->mesh->plink_lock
  74  */
  75 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  76 {
  77         lockdep_assert_held(&sta->mesh->plink_lock);
  78         sta->mesh->plink_state = NL80211_PLINK_LISTEN;
  79         sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
  80         sta->mesh->plink_retries = 0;
  81 }
  82
  83 /*
  84  * mesh_set_short_slot_time - enable / disable ERP short slot time.
  85  *
  86  * The standard indirectly mandates mesh STAs to turn off short slot time by
  87  * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
  88  * can't be sneaky about it. Enable short slot time if all mesh STAs in the
  89  * MBSS support ERP rates.
  90  *
  91  * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
  92  */
  93 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
  94 {
  95         struct ieee80211_local *local = sdata->local;
  96         enum nl80211_band band = ieee80211_get_sdata_band(sdata);
  97         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
  98         struct sta_info *sta;
  99         u32 erp_rates = 0, changed = 0;
 100         int i;
 101         bool short_slot = false;
 102
 103         if (band == NL80211_BAND_5GHZ) {
 104                 /* (IEEE 802.11-2012 19.4.5) */
 105                 short_slot = true;
 106                 goto out;
 107         } else if (band != NL80211_BAND_2GHZ)
 108                 goto out;
 109
 110         for (i = 0; i < sband->n_bitrates; i++)
 111                 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
 112                         erp_rates |= BIT(i);
 113
 114         if (!erp_rates)
 115                 goto out;
 116
 117         rcu_read_lock();
 118         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 119                 if (sdata != sta->sdata ||
 120                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 121                         continue;
 122
 123                 short_slot = false;
 124                 if (erp_rates & sta->sta.supp_rates[band])
 125                         short_slot = true;
 126                  else
 127                         break;
 128         }
 129         rcu_read_unlock();
 130
 131 out:
 132         if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 133                 sdata->vif.bss_conf.use_short_slot = short_slot;
 134                 changed = BSS_CHANGED_ERP_SLOT;
 135                 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 136                         sdata->vif.addr, short_slot);
 137         }
 138         return changed;
 139 }
 140
 141 /**
 142  * mesh_set_ht_prot_mode - set correct HT protection mode
 143  *
 144  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 145  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 146  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 147  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 148  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 149  * HT20 peer is present. Otherwise no-protection mode is selected.
 150  */
 151 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 152 {
 153         struct ieee80211_local *local = sdata->local;
 154         struct sta_info *sta;
 155         u16 ht_opmode;
 156         bool non_ht_sta = false, ht20_sta = false;
 157
 158         switch (sdata->vif.bss_conf.chandef.width) {
 159         case NL80211_CHAN_WIDTH_20_NOHT:
 160         case NL80211_CHAN_WIDTH_5:
 161         case NL80211_CHAN_WIDTH_10:
 162                 return 0;
 163         default:
 164                 break;
 165         }
 166
 167         rcu_read_lock();
 168         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 169                 if (sdata != sta->sdata ||
 170                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 171                         continue;
 172
 173                 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
 174                         continue;
 175
 176                 if (!sta->sta.ht_cap.ht_supported) {
 177                         mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
 178                                        sta->sta.addr);
 179                         non_ht_sta = true;
 180                         break;
 181                 }
 182
 183                 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
 184                 ht20_sta = true;
 185         }
 186         rcu_read_unlock();
 187
 188         if (non_ht_sta)
 189                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 190         else if (ht20_sta &&
 191                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 192                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 193         else
 194                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 195
 196         if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
 197                 return 0;
 198
 199         sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 200         sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 201         mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
 202         return BSS_CHANGED_HT;
 203 }
 204
 205 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 206                                struct sta_info *sta,
 207                                enum ieee80211_self_protected_actioncode action,
 208                                u8 *da, u16 llid, u16 plid, u16 reason)
 209 {
 210         struct ieee80211_local *local = sdata->local;
 211         struct sk_buff *skb;
 212         struct ieee80211_tx_info *info;
 213         struct ieee80211_mgmt *mgmt;
 214         bool include_plid = false;
 215         u16 peering_proto = 0;
 216         u8 *pos, ie_len = 4;
 217         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 218                       sizeof(mgmt->u.action.u.self_prot);
 219         int err = -ENOMEM;
 220
 221         skb = dev_alloc_skb(local->tx_headroom +
 222                             hdr_len +
 223                             2 + /* capability info */
 224                             2 + /* AID */
 225                             2 + 8 + /* supported rates */
 226                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 227                             2 + sdata->u.mesh.mesh_id_len +
 228                             2 + sizeof(struct ieee80211_meshconf_ie) +
 229                             2 + sizeof(struct ieee80211_ht_cap) +
 230                             2 + sizeof(struct ieee80211_ht_operation) +
 231                             2 + sizeof(struct ieee80211_vht_cap) +
 232                             2 + sizeof(struct ieee80211_vht_operation) +
 233                             2 + 8 + /* peering IE */
 234                             sdata->u.mesh.ie_len);
 235         if (!skb)
 236                 return err;
 237         info = IEEE80211_SKB_CB(skb);
 238         skb_reserve(skb, local->tx_headroom);
 239         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 240         memset(mgmt, 0, hdr_len);
 241         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 242                                           IEEE80211_STYPE_ACTION);
 243         memcpy(mgmt->da, da, ETH_ALEN);
 244         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 245         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 246         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 247         mgmt->u.action.u.self_prot.action_code = action;
 248
 249         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 250                 enum nl80211_band band = ieee80211_get_sdata_band(sdata);
 251
 252                 /* capability info */
 253                 pos = skb_put(skb, 2);
 254                 memset(pos, 0, 2);
 255                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 256                         /* AID */
 257                         pos = skb_put(skb, 2);
 258                         put_unaligned_le16(sta->sta.aid, pos);
 259                 }
 260                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 261                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 262                     mesh_add_rsn_ie(sdata, skb) ||
 263                     mesh_add_meshid_ie(sdata, skb) ||
 264                     mesh_add_meshconf_ie(sdata, skb))
 265                         goto free;
 266         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 267                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 268                 if (mesh_add_meshid_ie(sdata, skb))
 269                         goto free;
 270         }
 271
 272         /* Add Mesh Peering Management element */
 273         switch (action) {
 274         case WLAN_SP_MESH_PEERING_OPEN:
 275                 break;
 276         case WLAN_SP_MESH_PEERING_CONFIRM:
 277                 ie_len += 2;
 278                 include_plid = true;
 279                 break;
 280         case WLAN_SP_MESH_PEERING_CLOSE:
 281                 if (plid) {
 282                         ie_len += 2;
 283                         include_plid = true;
 284                 }
 285                 ie_len += 2;    /* reason code */
 286                 break;
 287         default:
 288                 err = -EINVAL;
 289                 goto free;
 290         }
 291
 292         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 293                 goto free;
 294
 295         pos = skb_put(skb, 2 + ie_len);
 296         *pos++ = WLAN_EID_PEER_MGMT;
 297         *pos++ = ie_len;
 298         memcpy(pos, &peering_proto, 2);
 299         pos += 2;
 300         put_unaligned_le16(llid, pos);
 301         pos += 2;
 302         if (include_plid) {
 303                 put_unaligned_le16(plid, pos);
 304                 pos += 2;
 305         }
 306         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 307                 put_unaligned_le16(reason, pos);
 308                 pos += 2;
 309         }
 310
 311         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 312                 if (mesh_add_ht_cap_ie(sdata, skb) ||
 313                     mesh_add_ht_oper_ie(sdata, skb) ||
 314                     mesh_add_vht_cap_ie(sdata, skb) ||
 315                     mesh_add_vht_oper_ie(sdata, skb))
 316                         goto free;
 317         }
 318
 319         if (mesh_add_vendor_ies(sdata, skb))
 320                 goto free;
 321
 322         ieee80211_tx_skb(sdata, skb);
 323         return 0;
 324 free:
 325         kfree_skb(skb);
 326         return err;
 327 }
 328
 329 /**
 330  * __mesh_plink_deactivate - deactivate mesh peer link
 331  *
 332  * @sta: mesh peer link to deactivate
 333  *
 334  * Mesh paths with this peer as next hop should be flushed
 335  * by the caller outside of plink_lock.
 336  *
 337  * Returns beacon changed flag if the beacon content changed.
 338  *
 339  * Locking: the caller must hold sta->mesh->plink_lock
 340  */
 341 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 342 {
 343         struct ieee80211_sub_if_data *sdata = sta->sdata;
 344         u32 changed = 0;
 345
 346         lockdep_assert_held(&sta->mesh->plink_lock);
 347
 348         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 349                 changed = mesh_plink_dec_estab_count(sdata);
 350         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 351
 352         ieee80211_mps_sta_status_update(sta);
 353         changed |= ieee80211_mps_set_sta_local_pm(sta,
 354                         NL80211_MESH_POWER_UNKNOWN);
 355
 356         return changed;
 357 }
 358
 359 /**
 360  * mesh_plink_deactivate - deactivate mesh peer link
 361  *
 362  * @sta: mesh peer link to deactivate
 363  *
 364  * All mesh paths with this peer as next hop will be flushed
 365  */
 366 u32 mesh_plink_deactivate(struct sta_info *sta)
 367 {
 368         struct ieee80211_sub_if_data *sdata = sta->sdata;
 369         u32 changed;
 370
 371         spin_lock_bh(&sta->mesh->plink_lock);
 372         changed = __mesh_plink_deactivate(sta);
 373
 374         if (!sdata->u.mesh.user_mpm) {
 375                 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
 376                 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
 377                                     sta->sta.addr, sta->mesh->llid,
 378                                     sta->mesh->plid, sta->mesh->reason);
 379         }
 380         spin_unlock_bh(&sta->mesh->plink_lock);
 381         if (!sdata->u.mesh.user_mpm)
 382                 del_timer_sync(&sta->mesh->plink_timer);
 383         mesh_path_flush_by_nexthop(sta);
 384
 385         /* make sure no readers can access nexthop sta from here on */
 386         synchronize_net();
 387
 388         return changed;
 389 }
 390
 391 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 392                                struct sta_info *sta,
 393                                struct ieee802_11_elems *elems, bool insert)
 394 {
 395         struct ieee80211_local *local = sdata->local;
 396         enum nl80211_band band = ieee80211_get_sdata_band(sdata);
 397         struct ieee80211_supported_band *sband;
 398         u32 rates, basic_rates = 0, changed = 0;
 399         enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
 400
 401         sband = local->hw.wiphy->bands[band];
 402         rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
 403
 404         spin_lock_bh(&sta->mesh->plink_lock);
 405         sta->rx_stats.last_rx = jiffies;
 406
 407         /* rates and capabilities don't change during peering */
 408         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
 409             sta->mesh->processed_beacon)
 410                 goto out;
 411         sta->mesh->processed_beacon = true;
 412
 413         if (sta->sta.supp_rates[band] != rates)
 414                 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 415         sta->sta.supp_rates[band] = rates;
 416
 417         if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 418                                               elems->ht_cap_elem, sta))
 419                 changed |= IEEE80211_RC_BW_CHANGED;
 420
 421         ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
 422                                             elems->vht_cap_elem, sta);
 423
 424         if (bw != sta->sta.bandwidth)
 425                 changed |= IEEE80211_RC_BW_CHANGED;
 426
 427         /* HT peer is operating 20MHz-only */
 428         if (elems->ht_operation &&
 429             !(elems->ht_operation->ht_param &
 430               IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 431                 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 432                         changed |= IEEE80211_RC_BW_CHANGED;
 433                 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 434         }
 435
 436         if (insert)
 437                 rate_control_rate_init(sta);
 438         else
 439                 rate_control_rate_update(local, sband, sta, changed);
 440 out:
 441         spin_unlock_bh(&sta->mesh->plink_lock);
 442 }
 443
 444 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
 445 {
 446         struct sta_info *sta;
 447         unsigned long *aid_map;
 448         int aid;
 449
 450         aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
 451                           sizeof(*aid_map), GFP_KERNEL);
 452         if (!aid_map)
 453                 return -ENOMEM;
 454
 455         /* reserve aid 0 for mcast indication */
 456         __set_bit(0, aid_map);
 457
 458         rcu_read_lock();
 459         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
 460                 __set_bit(sta->sta.aid, aid_map);
 461         rcu_read_unlock();
 462
 463         aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
 464         kfree(aid_map);
 465
 466         if (aid > IEEE80211_MAX_AID)
 467                 return -ENOBUFS;
 468
 469         return aid;
 470 }
 471
 472 static struct sta_info *
 473 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 474 {
 475         struct sta_info *sta;
 476         int aid;
 477
 478         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 479                 return NULL;
 480
 481         aid = mesh_allocate_aid(sdata);
 482         if (aid < 0)
 483                 return NULL;
 484
 485         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 486         if (!sta)
 487                 return NULL;
 488
 489         sta->mesh->plink_state = NL80211_PLINK_LISTEN;
 490         sta->sta.wme = true;
 491         sta->sta.aid = aid;
 492
 493         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 494         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 495         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 496
 497         return sta;
 498 }
 499
 500 static struct sta_info *
 501 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 502                     struct ieee802_11_elems *elems)
 503 {
 504         struct sta_info *sta = NULL;
 505
 506         /* Userspace handles station allocation */
 507         if (sdata->u.mesh.user_mpm ||
 508             sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 509                 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 510                                                    elems->ie_start,
 511                                                    elems->total_len,
 512                                                    GFP_KERNEL);
 513         else
 514                 sta = __mesh_sta_info_alloc(sdata, addr);
 515
 516         return sta;
 517 }
 518
 519 /*
 520  * mesh_sta_info_get - return mesh sta info entry for @addr.
 521  *
 522  * @sdata: local meshif
 523  * @addr: peer's address
 524  * @elems: IEs from beacon or mesh peering frame.
 525  *
 526  * Return existing or newly allocated sta_info under RCU read lock.
 527  * (re)initialize with given IEs.
 528  */
 529 static struct sta_info *
 530 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 531                   u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 532 {
 533         struct sta_info *sta = NULL;
 534
 535         rcu_read_lock();
 536         sta = sta_info_get(sdata, addr);
 537         if (sta) {
 538                 mesh_sta_info_init(sdata, sta, elems, false);
 539         } else {
 540                 rcu_read_unlock();
 541                 /* can't run atomic */
 542                 sta = mesh_sta_info_alloc(sdata, addr, elems);
 543                 if (!sta) {
 544                         rcu_read_lock();
 545                         return NULL;
 546                 }
 547
 548                 mesh_sta_info_init(sdata, sta, elems, true);
 549
 550                 if (sta_info_insert_rcu(sta))
 551                         return NULL;
 552         }
 553
 554         return sta;
 555 }
 556
 557 /*
 558  * mesh_neighbour_update - update or initialize new mesh neighbor.
 559  *
 560  * @sdata: local meshif
 561  * @addr: peer's address
 562  * @elems: IEs from beacon or mesh peering frame
 563  *
 564  * Initiates peering if appropriate.
 565  */
 566 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 567                            u8 *hw_addr,
 568                            struct ieee802_11_elems *elems)
 569 {
 570         struct sta_info *sta;
 571         u32 changed = 0;
 572
 573         sta = mesh_sta_info_get(sdata, hw_addr, elems);
 574         if (!sta)
 575                 goto out;
 576
 577         if (mesh_peer_accepts_plinks(elems) &&
 578             sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
 579             sdata->u.mesh.accepting_plinks &&
 580             sdata->u.mesh.mshcfg.auto_open_plinks &&
 581             rssi_threshold_check(sdata, sta))
 582                 changed = mesh_plink_open(sta);
 583
 584         ieee80211_mps_frame_release(sta, elems);
 585 out:
 586         rcu_read_unlock();
 587         ieee80211_mbss_info_change_notify(sdata, changed);
 588 }
 589
 590 static void mesh_plink_timer(unsigned long data)
 591 {
 592         struct sta_info *sta;
 593         u16 reason = 0;
 594         struct ieee80211_sub_if_data *sdata;
 595         struct mesh_config *mshcfg;
 596         enum ieee80211_self_protected_actioncode action = 0;
 597
 598         /*
 599          * This STA is valid because sta_info_destroy() will
 600          * del_timer_sync() this timer after having made sure
 601          * it cannot be readded (by deleting the plink.)
 602          */
 603         sta = (struct sta_info *) data;
 604
 605         if (sta->sdata->local->quiescing)
 606                 return;
 607
 608         spin_lock_bh(&sta->mesh->plink_lock);
 609
 610         /* If a timer fires just before a state transition on another CPU,
 611          * we may have already extended the timeout and changed state by the
 612          * time we've acquired the lock and arrived  here.  In that case,
 613          * skip this timer and wait for the new one.
 614          */
 615         if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
 616                 mpl_dbg(sta->sdata,
 617                         "Ignoring timer for %pM in state %s (timer adjusted)",
 618                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 619                 spin_unlock_bh(&sta->mesh->plink_lock);
 620                 return;
 621         }
 622
 623         /* del_timer() and handler may race when entering these states */
 624         if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
 625             sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
 626                 mpl_dbg(sta->sdata,
 627                         "Ignoring timer for %pM in state %s (timer deleted)",
 628                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 629                 spin_unlock_bh(&sta->mesh->plink_lock);
 630                 return;
 631         }
 632
 633         mpl_dbg(sta->sdata,
 634                 "Mesh plink timer for %pM fired on state %s\n",
 635                 sta->sta.addr, mplstates[sta->mesh->plink_state]);
 636         sdata = sta->sdata;
 637         mshcfg = &sdata->u.mesh.mshcfg;
 638
 639         switch (sta->mesh->plink_state) {
 640         case NL80211_PLINK_OPN_RCVD:
 641         case NL80211_PLINK_OPN_SNT:
 642                 /* retry timer */
 643                 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
 644                         u32 rand;
 645                         mpl_dbg(sta->sdata,
 646                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 647                                 sta->sta.addr, sta->mesh->plink_retries,
 648                                 sta->mesh->plink_timeout);
 649                         get_random_bytes(&rand, sizeof(u32));
 650                         sta->mesh->plink_timeout = sta->mesh->plink_timeout +
 651                                              rand % sta->mesh->plink_timeout;
 652                         ++sta->mesh->plink_retries;
 653                         mod_plink_timer(sta, sta->mesh->plink_timeout);
 654                         action = WLAN_SP_MESH_PEERING_OPEN;
 655                         break;
 656                 }
 657                 reason = WLAN_REASON_MESH_MAX_RETRIES;
 658                 /* fall through on else */
 659         case NL80211_PLINK_CNF_RCVD:
 660                 /* confirm timer */
 661                 if (!reason)
 662                         reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
 663                 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 664                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 665                 action = WLAN_SP_MESH_PEERING_CLOSE;
 666                 break;
 667         case NL80211_PLINK_HOLDING:
 668                 /* holding timer */
 669                 del_timer(&sta->mesh->plink_timer);
 670                 mesh_plink_fsm_restart(sta);
 671                 break;
 672         default:
 673                 break;
 674         }
 675         spin_unlock_bh(&sta->mesh->plink_lock);
 676         if (action)
 677                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 678                                     sta->mesh->llid, sta->mesh->plid, reason);
 679 }
 680
 681 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
 682 {
 683         sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
 684         sta->mesh->plink_timer.data = (unsigned long) sta;
 685         sta->mesh->plink_timer.function = mesh_plink_timer;
 686         sta->mesh->plink_timeout = timeout;
 687         add_timer(&sta->mesh->plink_timer);
 688 }
 689
 690 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
 691                         u16 llid)
 692 {
 693         struct ieee80211_local *local = sdata->local;
 694         bool in_use = false;
 695         struct sta_info *sta;
 696
 697         rcu_read_lock();
 698         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 699                 if (sdata != sta->sdata)
 700                         continue;
 701
 702                 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
 703                         in_use = true;
 704                         break;
 705                 }
 706         }
 707         rcu_read_unlock();
 708
 709         return in_use;
 710 }
 711
 712 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
 713 {
 714         u16 llid;
 715
 716         do {
 717                 get_random_bytes(&llid, sizeof(llid));
 718         } while (llid_in_use(sdata, llid));
 719
 720         return llid;
 721 }
 722
 723 u32 mesh_plink_open(struct sta_info *sta)
 724 {
 725         struct ieee80211_sub_if_data *sdata = sta->sdata;
 726         u32 changed;
 727
 728         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 729                 return 0;
 730
 731         spin_lock_bh(&sta->mesh->plink_lock);
 732         sta->mesh->llid = mesh_get_new_llid(sdata);
 733         if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
 734             sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
 735                 spin_unlock_bh(&sta->mesh->plink_lock);
 736                 return 0;
 737         }
 738         sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
 739         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 740         spin_unlock_bh(&sta->mesh->plink_lock);
 741         mpl_dbg(sdata,
 742                 "Mesh plink: starting establishment with %pM\n",
 743                 sta->sta.addr);
 744
 745         /* set the non-peer mode to active during peering */
 746         changed = ieee80211_mps_local_status_update(sdata);
 747
 748         mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
 749                             sta->sta.addr, sta->mesh->llid, 0, 0);
 750         return changed;
 751 }
 752
 753 u32 mesh_plink_block(struct sta_info *sta)
 754 {
 755         u32 changed;
 756
 757         spin_lock_bh(&sta->mesh->plink_lock);
 758         changed = __mesh_plink_deactivate(sta);
 759         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 760         spin_unlock_bh(&sta->mesh->plink_lock);
 761         mesh_path_flush_by_nexthop(sta);
 762
 763         return changed;
 764 }
 765
 766 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
 767                              struct sta_info *sta,
 768                              enum plink_event event)
 769 {
 770         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 771         u16 reason = (event == CLS_ACPT) ?
 772                      WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
 773
 774         sta->mesh->reason = reason;
 775         sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 776         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 777 }
 778
 779 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
 780                                 struct sta_info *sta)
 781 {
 782         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 783         u32 changed = 0;
 784
 785         del_timer(&sta->mesh->plink_timer);
 786         sta->mesh->plink_state = NL80211_PLINK_ESTAB;
 787         changed |= mesh_plink_inc_estab_count(sdata);
 788         changed |= mesh_set_ht_prot_mode(sdata);
 789         changed |= mesh_set_short_slot_time(sdata);
 790         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
 791         ieee80211_mps_sta_status_update(sta);
 792         changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
 793         return changed;
 794 }
 795
 796 /**
 797  * mesh_plink_fsm - step @sta MPM based on @event
 798  *
 799  * @sdata: interface
 800  * @sta: mesh neighbor
 801  * @event: peering event
 802  *
 803  * Return: changed MBSS flags
 804  */
 805 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
 806                           struct sta_info *sta, enum plink_event event)
 807 {
 808         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 809         enum ieee80211_self_protected_actioncode action = 0;
 810         u32 changed = 0;
 811         bool flush = false;
 812
 813         mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
 814                 mplstates[sta->mesh->plink_state], mplevents[event]);
 815
 816         spin_lock_bh(&sta->mesh->plink_lock);
 817         switch (sta->mesh->plink_state) {
 818         case NL80211_PLINK_LISTEN:
 819                 switch (event) {
 820                 case CLS_ACPT:
 821                         mesh_plink_fsm_restart(sta);
 822                         break;
 823                 case OPN_ACPT:
 824                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 825                         sta->mesh->llid = mesh_get_new_llid(sdata);
 826                         mesh_plink_timer_set(sta,
 827                                              mshcfg->dot11MeshRetryTimeout);
 828
 829                         /* set the non-peer mode to active during peering */
 830                         changed |= ieee80211_mps_local_status_update(sdata);
 831                         action = WLAN_SP_MESH_PEERING_OPEN;
 832                         break;
 833                 default:
 834                         break;
 835                 }
 836                 break;
 837         case NL80211_PLINK_OPN_SNT:
 838                 switch (event) {
 839                 case OPN_RJCT:
 840                 case CNF_RJCT:
 841                 case CLS_ACPT:
 842                         mesh_plink_close(sdata, sta, event);
 843                         action = WLAN_SP_MESH_PEERING_CLOSE;
 844                         break;
 845                 case OPN_ACPT:
 846                         /* retry timer is left untouched */
 847                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 848                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 849                         break;
 850                 case CNF_ACPT:
 851                         sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
 852                         mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
 853                         break;
 854                 default:
 855                         break;
 856                 }
 857                 break;
 858         case NL80211_PLINK_OPN_RCVD:
 859                 switch (event) {
 860                 case OPN_RJCT:
 861                 case CNF_RJCT:
 862                 case CLS_ACPT:
 863                         mesh_plink_close(sdata, sta, event);
 864                         action = WLAN_SP_MESH_PEERING_CLOSE;
 865                         break;
 866                 case OPN_ACPT:
 867                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 868                         break;
 869                 case CNF_ACPT:
 870                         changed |= mesh_plink_establish(sdata, sta);
 871                         break;
 872                 default:
 873                         break;
 874                 }
 875                 break;
 876         case NL80211_PLINK_CNF_RCVD:
 877                 switch (event) {
 878                 case OPN_RJCT:
 879                 case CNF_RJCT:
 880                 case CLS_ACPT:
 881                         mesh_plink_close(sdata, sta, event);
 882                         action = WLAN_SP_MESH_PEERING_CLOSE;
 883                         break;
 884                 case OPN_ACPT:
 885                         changed |= mesh_plink_establish(sdata, sta);
 886                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 887                         break;
 888                 default:
 889                         break;
 890                 }
 891                 break;
 892         case NL80211_PLINK_ESTAB:
 893                 switch (event) {
 894                 case CLS_ACPT:
 895                         changed |= __mesh_plink_deactivate(sta);
 896                         changed |= mesh_set_ht_prot_mode(sdata);
 897                         changed |= mesh_set_short_slot_time(sdata);
 898                         mesh_plink_close(sdata, sta, event);
 899                         action = WLAN_SP_MESH_PEERING_CLOSE;
 900                         flush = true;
 901                         break;
 902                 case OPN_ACPT:
 903                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 904                         break;
 905                 default:
 906                         break;
 907                 }
 908                 break;
 909         case NL80211_PLINK_HOLDING:
 910                 switch (event) {
 911                 case CLS_ACPT:
 912                         del_timer(&sta->mesh->plink_timer);
 913                         mesh_plink_fsm_restart(sta);
 914                         break;
 915                 case OPN_ACPT:
 916                 case CNF_ACPT:
 917                 case OPN_RJCT:
 918                 case CNF_RJCT:
 919                         action = WLAN_SP_MESH_PEERING_CLOSE;
 920                         break;
 921                 default:
 922                         break;
 923                 }
 924                 break;
 925         default:
 926                 /* should not get here, PLINK_BLOCKED is dealt with at the
 927                  * beginning of the function
 928                  */
 929                 break;
 930         }
 931         spin_unlock_bh(&sta->mesh->plink_lock);
 932         if (flush)
 933                 mesh_path_flush_by_nexthop(sta);
 934         if (action) {
 935                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 936                                     sta->mesh->llid, sta->mesh->plid,
 937                                     sta->mesh->reason);
 938
 939                 /* also send confirm in open case */
 940                 if (action == WLAN_SP_MESH_PEERING_OPEN) {
 941                         mesh_plink_frame_tx(sdata, sta,
 942                                             WLAN_SP_MESH_PEERING_CONFIRM,
 943                                             sta->sta.addr, sta->mesh->llid,
 944                                             sta->mesh->plid, 0);
 945                 }
 946         }
 947
 948         return changed;
 949 }
 950
 951 /*
 952  * mesh_plink_get_event - get correct MPM event
 953  *
 954  * @sdata: interface
 955  * @sta: peer, leave NULL if processing a frame from a new suitable peer
 956  * @elems: peering management IEs
 957  * @ftype: frame type
 958  * @llid: peer's peer link ID
 959  * @plid: peer's local link ID
 960  *
 961  * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
 962  * an error.
 963  */
 964 static enum plink_event
 965 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
 966                      struct sta_info *sta,
 967                      struct ieee802_11_elems *elems,
 968                      enum ieee80211_self_protected_actioncode ftype,
 969                      u16 llid, u16 plid)
 970 {
 971         enum plink_event event = PLINK_UNDEFINED;
 972         u8 ie_len = elems->peering_len;
 973         bool matches_local;
 974
 975         matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
 976                          mesh_matches_local(sdata, elems));
 977
 978         /* deny open request from non-matching peer */
 979         if (!matches_local && !sta) {
 980                 event = OPN_RJCT;
 981                 goto out;
 982         }
 983
 984         if (!sta) {
 985                 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
 986                         mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 987                         goto out;
 988                 }
 989                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 990                 if (!mesh_plink_free_count(sdata)) {
 991                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 992                         goto out;
 993                 }
 994
 995                 /* new matching peer */
 996                 event = OPN_ACPT;
 997                 goto out;
 998         } else {
 999                 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1000                         mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1001                         goto out;
1002                 }
1003                 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1004                         goto out;
1005         }
1006
1007         switch (ftype) {
1008         case WLAN_SP_MESH_PEERING_OPEN:
1009                 if (!matches_local)
1010                         event = OPN_RJCT;
1011                 if (!mesh_plink_free_count(sdata) ||
1012                     (sta->mesh->plid && sta->mesh->plid != plid))
1013                         event = OPN_IGNR;
1014                 else
1015                         event = OPN_ACPT;
1016                 break;
1017         case WLAN_SP_MESH_PEERING_CONFIRM:
1018                 if (!matches_local)
1019                         event = CNF_RJCT;
1020                 if (!mesh_plink_free_count(sdata) ||
1021                     sta->mesh->llid != llid ||
1022                     (sta->mesh->plid && sta->mesh->plid != plid))
1023                         event = CNF_IGNR;
1024                 else
1025                         event = CNF_ACPT;
1026                 break;
1027         case WLAN_SP_MESH_PEERING_CLOSE:
1028                 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1029                         /* Do not check for llid or plid. This does not
1030                          * follow the standard but since multiple plinks
1031                          * per sta are not supported, it is necessary in
1032                          * order to avoid a livelock when MP A sees an
1033                          * establish peer link to MP B but MP B does not
1034                          * see it. This can be caused by a timeout in
1035                          * B's peer link establishment or B beign
1036                          * restarted.
1037                          */
1038                         event = CLS_ACPT;
1039                 else if (sta->mesh->plid != plid)
1040                         event = CLS_IGNR;
1041                 else if (ie_len == 8 && sta->mesh->llid != llid)
1042                         event = CLS_IGNR;
1043                 else
1044                         event = CLS_ACPT;
1045                 break;
1046         default:
1047                 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1048                 break;
1049         }
1050
1051 out:
1052         return event;
1053 }
1054
1055 static void
1056 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1057                          struct ieee80211_mgmt *mgmt,
1058                          struct ieee802_11_elems *elems)
1059 {
1060
1061         struct sta_info *sta;
1062         enum plink_event event;
1063         enum ieee80211_self_protected_actioncode ftype;
1064         u32 changed = 0;
1065         u8 ie_len = elems->peering_len;
1066         u16 plid, llid = 0;
1067
1068         if (!elems->peering) {
1069                 mpl_dbg(sdata,
1070                         "Mesh plink: missing necessary peer link ie\n");
1071                 return;
1072         }
1073
1074         if (elems->rsn_len &&
1075             sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1076                 mpl_dbg(sdata,
1077                         "Mesh plink: can't establish link with secure peer\n");
1078                 return;
1079         }
1080
1081         ftype = mgmt->u.action.u.self_prot.action_code;
1082         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1083             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1084             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1085                                                         && ie_len != 8)) {
1086                 mpl_dbg(sdata,
1087                         "Mesh plink: incorrect plink ie length %d %d\n",
1088                         ftype, ie_len);
1089                 return;
1090         }
1091
1092         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1093             (!elems->mesh_id || !elems->mesh_config)) {
1094                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1095                 return;
1096         }
1097         /* Note the lines below are correct, the llid in the frame is the plid
1098          * from the point of view of this host.
1099          */
1100         plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1101         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1102             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1103                 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1104
1105         /* WARNING: Only for sta pointer, is dropped & re-acquired */
1106         rcu_read_lock();
1107
1108         sta = sta_info_get(sdata, mgmt->sa);
1109
1110         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1111             !rssi_threshold_check(sdata, sta)) {
1112                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1113                         mgmt->sa);
1114                 goto unlock_rcu;
1115         }
1116
1117         /* Now we will figure out the appropriate event... */
1118         event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1119
1120         if (event == OPN_ACPT) {
1121                 rcu_read_unlock();
1122                 /* allocate sta entry if necessary and update info */
1123                 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1124                 if (!sta) {
1125                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1126                         goto unlock_rcu;
1127                 }
1128                 sta->mesh->plid = plid;
1129         } else if (!sta && event == OPN_RJCT) {
1130                 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1131                                     mgmt->sa, 0, plid,
1132                                     WLAN_REASON_MESH_CONFIG);
1133                 goto unlock_rcu;
1134         } else if (!sta || event == PLINK_UNDEFINED) {
1135                 /* something went wrong */
1136                 goto unlock_rcu;
1137         }
1138
1139         if (event == CNF_ACPT) {
1140                 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1141                 if (!sta->mesh->plid)
1142                         sta->mesh->plid = plid;
1143
1144                 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1145         }
1146
1147         changed |= mesh_plink_fsm(sdata, sta, event);
1148
1149 unlock_rcu:
1150         rcu_read_unlock();
1151
1152         if (changed)
1153                 ieee80211_mbss_info_change_notify(sdata, changed);
1154 }
1155
1156 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1157                          struct ieee80211_mgmt *mgmt, size_t len,
1158                          struct ieee80211_rx_status *rx_status)
1159 {
1160         struct ieee802_11_elems elems;
1161         size_t baselen;
1162         u8 *baseaddr;
1163
1164         /* need action_code, aux */
1165         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1166                 return;
1167
1168         if (sdata->u.mesh.user_mpm)
1169                 /* userspace must register for these */
1170                 return;
1171
1172         if (is_multicast_ether_addr(mgmt->da)) {
1173                 mpl_dbg(sdata,
1174                         "Mesh plink: ignore frame from multicast address\n");
1175                 return;
1176         }
1177
1178         baseaddr = mgmt->u.action.u.self_prot.variable;
1179         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1180         if (mgmt->u.action.u.self_prot.action_code ==
1181                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
1182                 baseaddr += 4;
1183                 baselen += 4;
1184
1185                 if (baselen > len)
1186                         return;
1187         }
1188         ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1189         mesh_process_plink_frame(sdata, mgmt, &elems);
1190 }