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         enum nl80211_band band = ieee80211_get_sdata_band(sdata);
  99         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
 100         struct sta_info *sta;
 101         u32 erp_rates = 0, changed = 0;
 102         int i;
 103         bool short_slot = false;
 104
 105         if (band == NL80211_BAND_5GHZ) {
 106                 /* (IEEE 802.11-2012 19.4.5) */
 107                 short_slot = true;
 108                 goto out;
 109         } else if (band != NL80211_BAND_2GHZ)
 110                 goto out;
 111
 112         for (i = 0; i < sband->n_bitrates; i++)
 113                 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
 114                         erp_rates |= BIT(i);
 115
 116         if (!erp_rates)
 117                 goto out;
 118
 119         rcu_read_lock();
 120         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 121                 if (sdata != sta->sdata ||
 122                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 123                         continue;
 124
 125                 short_slot = false;
 126                 if (erp_rates & sta->sta.supp_rates[band])
 127                         short_slot = true;
 128                  else
 129                         break;
 130         }
 131         rcu_read_unlock();
 132
 133 out:
 134         if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 135                 sdata->vif.bss_conf.use_short_slot = short_slot;
 136                 changed = BSS_CHANGED_ERP_SLOT;
 137                 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 138                         sdata->vif.addr, short_slot);
 139         }
 140         return changed;
 141 }
 142
 143 /**
 144  * mesh_set_ht_prot_mode - set correct HT protection mode
 145  *
 146  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 147  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 148  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 149  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 150  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 151  * HT20 peer is present. Otherwise no-protection mode is selected.
 152  */
 153 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 154 {
 155         struct ieee80211_local *local = sdata->local;
 156         struct sta_info *sta;
 157         u16 ht_opmode;
 158         bool non_ht_sta = false, ht20_sta = false;
 159
 160         switch (sdata->vif.bss_conf.chandef.width) {
 161         case NL80211_CHAN_WIDTH_20_NOHT:
 162         case NL80211_CHAN_WIDTH_5:
 163         case NL80211_CHAN_WIDTH_10:
 164                 return 0;
 165         default:
 166                 break;
 167         }
 168
 169         rcu_read_lock();
 170         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 171                 if (sdata != sta->sdata ||
 172                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 173                         continue;
 174
 175                 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
 176                         continue;
 177
 178                 if (!sta->sta.ht_cap.ht_supported) {
 179                         mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
 180                                        sta->sta.addr);
 181                         non_ht_sta = true;
 182                         break;
 183                 }
 184
 185                 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
 186                 ht20_sta = true;
 187         }
 188         rcu_read_unlock();
 189
 190         if (non_ht_sta)
 191                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 192         else if (ht20_sta &&
 193                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 194                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 195         else
 196                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 197
 198         if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
 199                 return 0;
 200
 201         sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 202         sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 203         mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
 204         return BSS_CHANGED_HT;
 205 }
 206
 207 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 208                                struct sta_info *sta,
 209                                enum ieee80211_self_protected_actioncode action,
 210                                u8 *da, u16 llid, u16 plid, u16 reason)
 211 {
 212         struct ieee80211_local *local = sdata->local;
 213         struct sk_buff *skb;
 214         struct ieee80211_tx_info *info;
 215         struct ieee80211_mgmt *mgmt;
 216         bool include_plid = false;
 217         u16 peering_proto = 0;
 218         u8 *pos, ie_len = 4;
 219         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 220                       sizeof(mgmt->u.action.u.self_prot);
 221         int err = -ENOMEM;
 222
 223         skb = dev_alloc_skb(local->tx_headroom +
 224                             hdr_len +
 225                             2 + /* capability info */
 226                             2 + /* AID */
 227                             2 + 8 + /* supported rates */
 228                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 229                             2 + sdata->u.mesh.mesh_id_len +
 230                             2 + sizeof(struct ieee80211_meshconf_ie) +
 231                             2 + sizeof(struct ieee80211_ht_cap) +
 232                             2 + sizeof(struct ieee80211_ht_operation) +
 233                             2 + sizeof(struct ieee80211_vht_cap) +
 234                             2 + sizeof(struct ieee80211_vht_operation) +
 235                             2 + 8 + /* peering IE */
 236                             sdata->u.mesh.ie_len);
 237         if (!skb)
 238                 return err;
 239         info = IEEE80211_SKB_CB(skb);
 240         skb_reserve(skb, local->tx_headroom);
 241         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 242         memset(mgmt, 0, hdr_len);
 243         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 244                                           IEEE80211_STYPE_ACTION);
 245         memcpy(mgmt->da, da, ETH_ALEN);
 246         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 247         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 248         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 249         mgmt->u.action.u.self_prot.action_code = action;
 250
 251         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 252                 enum nl80211_band band = ieee80211_get_sdata_band(sdata);
 253
 254                 /* capability info */
 255                 pos = skb_put(skb, 2);
 256                 memset(pos, 0, 2);
 257                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 258                         /* AID */
 259                         pos = skb_put(skb, 2);
 260                         put_unaligned_le16(sta->sta.aid, pos);
 261                 }
 262                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 263                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 264                     mesh_add_rsn_ie(sdata, skb) ||
 265                     mesh_add_meshid_ie(sdata, skb) ||
 266                     mesh_add_meshconf_ie(sdata, skb))
 267                         goto free;
 268         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 269                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 270                 if (mesh_add_meshid_ie(sdata, skb))
 271                         goto free;
 272         }
 273
 274         /* Add Mesh Peering Management element */
 275         switch (action) {
 276         case WLAN_SP_MESH_PEERING_OPEN:
 277                 break;
 278         case WLAN_SP_MESH_PEERING_CONFIRM:
 279                 ie_len += 2;
 280                 include_plid = true;
 281                 break;
 282         case WLAN_SP_MESH_PEERING_CLOSE:
 283                 if (plid) {
 284                         ie_len += 2;
 285                         include_plid = true;
 286                 }
 287                 ie_len += 2;    /* reason code */
 288                 break;
 289         default:
 290                 err = -EINVAL;
 291                 goto free;
 292         }
 293
 294         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 295                 goto free;
 296
 297         pos = skb_put(skb, 2 + ie_len);
 298         *pos++ = WLAN_EID_PEER_MGMT;
 299         *pos++ = ie_len;
 300         memcpy(pos, &peering_proto, 2);
 301         pos += 2;
 302         put_unaligned_le16(llid, pos);
 303         pos += 2;
 304         if (include_plid) {
 305                 put_unaligned_le16(plid, pos);
 306                 pos += 2;
 307         }
 308         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 309                 put_unaligned_le16(reason, pos);
 310                 pos += 2;
 311         }
 312
 313         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 314                 if (mesh_add_ht_cap_ie(sdata, skb) ||
 315                     mesh_add_ht_oper_ie(sdata, skb) ||
 316                     mesh_add_vht_cap_ie(sdata, skb) ||
 317                     mesh_add_vht_oper_ie(sdata, skb))
 318                         goto free;
 319         }
 320
 321         if (mesh_add_vendor_ies(sdata, skb))
 322                 goto free;
 323
 324         ieee80211_tx_skb(sdata, skb);
 325         return 0;
 326 free:
 327         kfree_skb(skb);
 328         return err;
 329 }
 330
 331 /**
 332  * __mesh_plink_deactivate - deactivate mesh peer link
 333  *
 334  * @sta: mesh peer link to deactivate
 335  *
 336  * Mesh paths with this peer as next hop should be flushed
 337  * by the caller outside of plink_lock.
 338  *
 339  * Returns beacon changed flag if the beacon content changed.
 340  *
 341  * Locking: the caller must hold sta->mesh->plink_lock
 342  */
 343 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 344 {
 345         struct ieee80211_sub_if_data *sdata = sta->sdata;
 346         u32 changed = 0;
 347
 348         lockdep_assert_held(&sta->mesh->plink_lock);
 349
 350         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 351                 changed = mesh_plink_dec_estab_count(sdata);
 352         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 353
 354         ieee80211_mps_sta_status_update(sta);
 355         changed |= ieee80211_mps_set_sta_local_pm(sta,
 356                         NL80211_MESH_POWER_UNKNOWN);
 357
 358         return changed;
 359 }
 360
 361 /**
 362  * mesh_plink_deactivate - deactivate mesh peer link
 363  *
 364  * @sta: mesh peer link to deactivate
 365  *
 366  * All mesh paths with this peer as next hop will be flushed
 367  */
 368 u32 mesh_plink_deactivate(struct sta_info *sta)
 369 {
 370         struct ieee80211_sub_if_data *sdata = sta->sdata;
 371         u32 changed;
 372
 373         spin_lock_bh(&sta->mesh->plink_lock);
 374         changed = __mesh_plink_deactivate(sta);
 375
 376         if (!sdata->u.mesh.user_mpm) {
 377                 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
 378                 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
 379                                     sta->sta.addr, sta->mesh->llid,
 380                                     sta->mesh->plid, sta->mesh->reason);
 381         }
 382         spin_unlock_bh(&sta->mesh->plink_lock);
 383         if (!sdata->u.mesh.user_mpm)
 384                 del_timer_sync(&sta->mesh->plink_timer);
 385         mesh_path_flush_by_nexthop(sta);
 386
 387         /* make sure no readers can access nexthop sta from here on */
 388         synchronize_net();
 389
 390         return changed;
 391 }
 392
 393 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 394                                struct sta_info *sta,
 395                                struct ieee802_11_elems *elems, bool insert)
 396 {
 397         struct ieee80211_local *local = sdata->local;
 398         enum nl80211_band band = ieee80211_get_sdata_band(sdata);
 399         struct ieee80211_supported_band *sband;
 400         u32 rates, basic_rates = 0, changed = 0;
 401         enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
 402
 403         sband = local->hw.wiphy->bands[band];
 404         rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
 405
 406         spin_lock_bh(&sta->mesh->plink_lock);
 407         sta->rx_stats.last_rx = jiffies;
 408
 409         /* rates and capabilities don't change during peering */
 410         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
 411             sta->mesh->processed_beacon)
 412                 goto out;
 413         sta->mesh->processed_beacon = true;
 414
 415         if (sta->sta.supp_rates[band] != rates)
 416                 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 417         sta->sta.supp_rates[band] = rates;
 418
 419         if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 420                                               elems->ht_cap_elem, sta))
 421                 changed |= IEEE80211_RC_BW_CHANGED;
 422
 423         ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
 424                                             elems->vht_cap_elem, sta);
 425
 426         if (bw != sta->sta.bandwidth)
 427                 changed |= IEEE80211_RC_BW_CHANGED;
 428
 429         /* HT peer is operating 20MHz-only */
 430         if (elems->ht_operation &&
 431             !(elems->ht_operation->ht_param &
 432               IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 433                 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 434                         changed |= IEEE80211_RC_BW_CHANGED;
 435                 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 436         }
 437
 438         if (insert)
 439                 rate_control_rate_init(sta);
 440         else
 441                 rate_control_rate_update(local, sband, sta, changed);
 442 out:
 443         spin_unlock_bh(&sta->mesh->plink_lock);
 444 }
 445
 446 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
 447 {
 448         struct sta_info *sta;
 449         unsigned long *aid_map;
 450         int aid;
 451
 452         aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
 453                           sizeof(*aid_map), GFP_KERNEL);
 454         if (!aid_map)
 455                 return -ENOMEM;
 456
 457         /* reserve aid 0 for mcast indication */
 458         __set_bit(0, aid_map);
 459
 460         rcu_read_lock();
 461         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
 462                 __set_bit(sta->sta.aid, aid_map);
 463         rcu_read_unlock();
 464
 465         aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
 466         kfree(aid_map);
 467
 468         if (aid > IEEE80211_MAX_AID)
 469                 return -ENOBUFS;
 470
 471         return aid;
 472 }
 473
 474 static struct sta_info *
 475 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 476 {
 477         struct sta_info *sta;
 478         int aid;
 479
 480         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 481                 return NULL;
 482
 483         aid = mesh_allocate_aid(sdata);
 484         if (aid < 0)
 485                 return NULL;
 486
 487         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 488         if (!sta)
 489                 return NULL;
 490
 491         sta->mesh->plink_state = NL80211_PLINK_LISTEN;
 492         sta->sta.wme = true;
 493         sta->sta.aid = aid;
 494
 495         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 496         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 497         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 498
 499         return sta;
 500 }
 501
 502 static struct sta_info *
 503 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 504                     struct ieee802_11_elems *elems)
 505 {
 506         struct sta_info *sta = NULL;
 507
 508         /* Userspace handles station allocation */
 509         if (sdata->u.mesh.user_mpm ||
 510             sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
 511                 if (mesh_peer_accepts_plinks(elems) &&
 512                     mesh_plink_availables(sdata))
 513                         cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 514                                                            elems->ie_start,
 515                                                            elems->total_len,
 516                                                            GFP_KERNEL);
 517         } else
 518                 sta = __mesh_sta_info_alloc(sdata, addr);
 519
 520         return sta;
 521 }
 522
 523 /*
 524  * mesh_sta_info_get - return mesh sta info entry for @addr.
 525  *
 526  * @sdata: local meshif
 527  * @addr: peer's address
 528  * @elems: IEs from beacon or mesh peering frame.
 529  *
 530  * Return existing or newly allocated sta_info under RCU read lock.
 531  * (re)initialize with given IEs.
 532  */
 533 static struct sta_info *
 534 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 535                   u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 536 {
 537         struct sta_info *sta = NULL;
 538
 539         rcu_read_lock();
 540         sta = sta_info_get(sdata, addr);
 541         if (sta) {
 542                 mesh_sta_info_init(sdata, sta, elems, false);
 543         } else {
 544                 rcu_read_unlock();
 545                 /* can't run atomic */
 546                 sta = mesh_sta_info_alloc(sdata, addr, elems);
 547                 if (!sta) {
 548                         rcu_read_lock();
 549                         return NULL;
 550                 }
 551
 552                 mesh_sta_info_init(sdata, sta, elems, true);
 553
 554                 if (sta_info_insert_rcu(sta))
 555                         return NULL;
 556         }
 557
 558         return sta;
 559 }
 560
 561 /*
 562  * mesh_neighbour_update - update or initialize new mesh neighbor.
 563  *
 564  * @sdata: local meshif
 565  * @addr: peer's address
 566  * @elems: IEs from beacon or mesh peering frame
 567  *
 568  * Initiates peering if appropriate.
 569  */
 570 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 571                            u8 *hw_addr,
 572                            struct ieee802_11_elems *elems)
 573 {
 574         struct sta_info *sta;
 575         u32 changed = 0;
 576
 577         sta = mesh_sta_info_get(sdata, hw_addr, elems);
 578         if (!sta)
 579                 goto out;
 580
 581         if (mesh_peer_accepts_plinks(elems) &&
 582             sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
 583             sdata->u.mesh.accepting_plinks &&
 584             sdata->u.mesh.mshcfg.auto_open_plinks &&
 585             rssi_threshold_check(sdata, sta))
 586                 changed = mesh_plink_open(sta);
 587
 588         ieee80211_mps_frame_release(sta, elems);
 589 out:
 590         rcu_read_unlock();
 591         ieee80211_mbss_info_change_notify(sdata, changed);
 592 }
 593
 594 static void mesh_plink_timer(unsigned long data)
 595 {
 596         struct sta_info *sta;
 597         u16 reason = 0;
 598         struct ieee80211_sub_if_data *sdata;
 599         struct mesh_config *mshcfg;
 600         enum ieee80211_self_protected_actioncode action = 0;
 601
 602         /*
 603          * This STA is valid because sta_info_destroy() will
 604          * del_timer_sync() this timer after having made sure
 605          * it cannot be readded (by deleting the plink.)
 606          */
 607         sta = (struct sta_info *) data;
 608
 609         if (sta->sdata->local->quiescing)
 610                 return;
 611
 612         spin_lock_bh(&sta->mesh->plink_lock);
 613
 614         /* If a timer fires just before a state transition on another CPU,
 615          * we may have already extended the timeout and changed state by the
 616          * time we've acquired the lock and arrived  here.  In that case,
 617          * skip this timer and wait for the new one.
 618          */
 619         if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
 620                 mpl_dbg(sta->sdata,
 621                         "Ignoring timer for %pM in state %s (timer adjusted)",
 622                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 623                 spin_unlock_bh(&sta->mesh->plink_lock);
 624                 return;
 625         }
 626
 627         /* del_timer() and handler may race when entering these states */
 628         if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
 629             sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
 630                 mpl_dbg(sta->sdata,
 631                         "Ignoring timer for %pM in state %s (timer deleted)",
 632                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 633                 spin_unlock_bh(&sta->mesh->plink_lock);
 634                 return;
 635         }
 636
 637         mpl_dbg(sta->sdata,
 638                 "Mesh plink timer for %pM fired on state %s\n",
 639                 sta->sta.addr, mplstates[sta->mesh->plink_state]);
 640         sdata = sta->sdata;
 641         mshcfg = &sdata->u.mesh.mshcfg;
 642
 643         switch (sta->mesh->plink_state) {
 644         case NL80211_PLINK_OPN_RCVD:
 645         case NL80211_PLINK_OPN_SNT:
 646                 /* retry timer */
 647                 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
 648                         u32 rand;
 649                         mpl_dbg(sta->sdata,
 650                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 651                                 sta->sta.addr, sta->mesh->plink_retries,
 652                                 sta->mesh->plink_timeout);
 653                         get_random_bytes(&rand, sizeof(u32));
 654                         sta->mesh->plink_timeout = sta->mesh->plink_timeout +
 655                                              rand % sta->mesh->plink_timeout;
 656                         ++sta->mesh->plink_retries;
 657                         mod_plink_timer(sta, sta->mesh->plink_timeout);
 658                         action = WLAN_SP_MESH_PEERING_OPEN;
 659                         break;
 660                 }
 661                 reason = WLAN_REASON_MESH_MAX_RETRIES;
 662                 /* fall through on else */
 663         case NL80211_PLINK_CNF_RCVD:
 664                 /* confirm timer */
 665                 if (!reason)
 666                         reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
 667                 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 668                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 669                 action = WLAN_SP_MESH_PEERING_CLOSE;
 670                 break;
 671         case NL80211_PLINK_HOLDING:
 672                 /* holding timer */
 673                 del_timer(&sta->mesh->plink_timer);
 674                 mesh_plink_fsm_restart(sta);
 675                 break;
 676         default:
 677                 break;
 678         }
 679         spin_unlock_bh(&sta->mesh->plink_lock);
 680         if (action)
 681                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 682                                     sta->mesh->llid, sta->mesh->plid, reason);
 683 }
 684
 685 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
 686 {
 687         sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout);
 688         sta->mesh->plink_timer.data = (unsigned long) sta;
 689         sta->mesh->plink_timer.function = mesh_plink_timer;
 690         sta->mesh->plink_timeout = timeout;
 691         add_timer(&sta->mesh->plink_timer);
 692 }
 693
 694 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
 695                         u16 llid)
 696 {
 697         struct ieee80211_local *local = sdata->local;
 698         bool in_use = false;
 699         struct sta_info *sta;
 700
 701         rcu_read_lock();
 702         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 703                 if (sdata != sta->sdata)
 704                         continue;
 705
 706                 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
 707                         in_use = true;
 708                         break;
 709                 }
 710         }
 711         rcu_read_unlock();
 712
 713         return in_use;
 714 }
 715
 716 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
 717 {
 718         u16 llid;
 719
 720         do {
 721                 get_random_bytes(&llid, sizeof(llid));
 722         } while (llid_in_use(sdata, llid));
 723
 724         return llid;
 725 }
 726
 727 u32 mesh_plink_open(struct sta_info *sta)
 728 {
 729         struct ieee80211_sub_if_data *sdata = sta->sdata;
 730         u32 changed;
 731
 732         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 733                 return 0;
 734
 735         spin_lock_bh(&sta->mesh->plink_lock);
 736         sta->mesh->llid = mesh_get_new_llid(sdata);
 737         if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
 738             sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
 739                 spin_unlock_bh(&sta->mesh->plink_lock);
 740                 return 0;
 741         }
 742         sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
 743         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 744         spin_unlock_bh(&sta->mesh->plink_lock);
 745         mpl_dbg(sdata,
 746                 "Mesh plink: starting establishment with %pM\n",
 747                 sta->sta.addr);
 748
 749         /* set the non-peer mode to active during peering */
 750         changed = ieee80211_mps_local_status_update(sdata);
 751
 752         mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
 753                             sta->sta.addr, sta->mesh->llid, 0, 0);
 754         return changed;
 755 }
 756
 757 u32 mesh_plink_block(struct sta_info *sta)
 758 {
 759         u32 changed;
 760
 761         spin_lock_bh(&sta->mesh->plink_lock);
 762         changed = __mesh_plink_deactivate(sta);
 763         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 764         spin_unlock_bh(&sta->mesh->plink_lock);
 765         mesh_path_flush_by_nexthop(sta);
 766
 767         return changed;
 768 }
 769
 770 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
 771                              struct sta_info *sta,
 772                              enum plink_event event)
 773 {
 774         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 775         u16 reason = (event == CLS_ACPT) ?
 776                      WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
 777
 778         sta->mesh->reason = reason;
 779         sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 780         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 781 }
 782
 783 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
 784                                 struct sta_info *sta)
 785 {
 786         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 787         u32 changed = 0;
 788
 789         del_timer(&sta->mesh->plink_timer);
 790         sta->mesh->plink_state = NL80211_PLINK_ESTAB;
 791         changed |= mesh_plink_inc_estab_count(sdata);
 792         changed |= mesh_set_ht_prot_mode(sdata);
 793         changed |= mesh_set_short_slot_time(sdata);
 794         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
 795         ieee80211_mps_sta_status_update(sta);
 796         changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
 797         return changed;
 798 }
 799
 800 /**
 801  * mesh_plink_fsm - step @sta MPM based on @event
 802  *
 803  * @sdata: interface
 804  * @sta: mesh neighbor
 805  * @event: peering event
 806  *
 807  * Return: changed MBSS flags
 808  */
 809 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
 810                           struct sta_info *sta, enum plink_event event)
 811 {
 812         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 813         enum ieee80211_self_protected_actioncode action = 0;
 814         u32 changed = 0;
 815         bool flush = false;
 816
 817         mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
 818                 mplstates[sta->mesh->plink_state], mplevents[event]);
 819
 820         spin_lock_bh(&sta->mesh->plink_lock);
 821         switch (sta->mesh->plink_state) {
 822         case NL80211_PLINK_LISTEN:
 823                 switch (event) {
 824                 case CLS_ACPT:
 825                         mesh_plink_fsm_restart(sta);
 826                         break;
 827                 case OPN_ACPT:
 828                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 829                         sta->mesh->llid = mesh_get_new_llid(sdata);
 830                         mesh_plink_timer_set(sta,
 831                                              mshcfg->dot11MeshRetryTimeout);
 832
 833                         /* set the non-peer mode to active during peering */
 834                         changed |= ieee80211_mps_local_status_update(sdata);
 835                         action = WLAN_SP_MESH_PEERING_OPEN;
 836                         break;
 837                 default:
 838                         break;
 839                 }
 840                 break;
 841         case NL80211_PLINK_OPN_SNT:
 842                 switch (event) {
 843                 case OPN_RJCT:
 844                 case CNF_RJCT:
 845                 case CLS_ACPT:
 846                         mesh_plink_close(sdata, sta, event);
 847                         action = WLAN_SP_MESH_PEERING_CLOSE;
 848                         break;
 849                 case OPN_ACPT:
 850                         /* retry timer is left untouched */
 851                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 852                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 853                         break;
 854                 case CNF_ACPT:
 855                         sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
 856                         mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
 857                         break;
 858                 default:
 859                         break;
 860                 }
 861                 break;
 862         case NL80211_PLINK_OPN_RCVD:
 863                 switch (event) {
 864                 case OPN_RJCT:
 865                 case CNF_RJCT:
 866                 case CLS_ACPT:
 867                         mesh_plink_close(sdata, sta, event);
 868                         action = WLAN_SP_MESH_PEERING_CLOSE;
 869                         break;
 870                 case OPN_ACPT:
 871                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 872                         break;
 873                 case CNF_ACPT:
 874                         changed |= mesh_plink_establish(sdata, sta);
 875                         break;
 876                 default:
 877                         break;
 878                 }
 879                 break;
 880         case NL80211_PLINK_CNF_RCVD:
 881                 switch (event) {
 882                 case OPN_RJCT:
 883                 case CNF_RJCT:
 884                 case CLS_ACPT:
 885                         mesh_plink_close(sdata, sta, event);
 886                         action = WLAN_SP_MESH_PEERING_CLOSE;
 887                         break;
 888                 case OPN_ACPT:
 889                         changed |= mesh_plink_establish(sdata, sta);
 890                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 891                         break;
 892                 default:
 893                         break;
 894                 }
 895                 break;
 896         case NL80211_PLINK_ESTAB:
 897                 switch (event) {
 898                 case CLS_ACPT:
 899                         changed |= __mesh_plink_deactivate(sta);
 900                         changed |= mesh_set_ht_prot_mode(sdata);
 901                         changed |= mesh_set_short_slot_time(sdata);
 902                         mesh_plink_close(sdata, sta, event);
 903                         action = WLAN_SP_MESH_PEERING_CLOSE;
 904                         flush = true;
 905                         break;
 906                 case OPN_ACPT:
 907                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 908                         break;
 909                 default:
 910                         break;
 911                 }
 912                 break;
 913         case NL80211_PLINK_HOLDING:
 914                 switch (event) {
 915                 case CLS_ACPT:
 916                         del_timer(&sta->mesh->plink_timer);
 917                         mesh_plink_fsm_restart(sta);
 918                         break;
 919                 case OPN_ACPT:
 920                 case CNF_ACPT:
 921                 case OPN_RJCT:
 922                 case CNF_RJCT:
 923                         action = WLAN_SP_MESH_PEERING_CLOSE;
 924                         break;
 925                 default:
 926                         break;
 927                 }
 928                 break;
 929         default:
 930                 /* should not get here, PLINK_BLOCKED is dealt with at the
 931                  * beginning of the function
 932                  */
 933                 break;
 934         }
 935         spin_unlock_bh(&sta->mesh->plink_lock);
 936         if (flush)
 937                 mesh_path_flush_by_nexthop(sta);
 938         if (action) {
 939                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 940                                     sta->mesh->llid, sta->mesh->plid,
 941                                     sta->mesh->reason);
 942
 943                 /* also send confirm in open case */
 944                 if (action == WLAN_SP_MESH_PEERING_OPEN) {
 945                         mesh_plink_frame_tx(sdata, sta,
 946                                             WLAN_SP_MESH_PEERING_CONFIRM,
 947                                             sta->sta.addr, sta->mesh->llid,
 948                                             sta->mesh->plid, 0);
 949                 }
 950         }
 951
 952         return changed;
 953 }
 954
 955 /*
 956  * mesh_plink_get_event - get correct MPM event
 957  *
 958  * @sdata: interface
 959  * @sta: peer, leave NULL if processing a frame from a new suitable peer
 960  * @elems: peering management IEs
 961  * @ftype: frame type
 962  * @llid: peer's peer link ID
 963  * @plid: peer's local link ID
 964  *
 965  * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
 966  * an error.
 967  */
 968 static enum plink_event
 969 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
 970                      struct sta_info *sta,
 971                      struct ieee802_11_elems *elems,
 972                      enum ieee80211_self_protected_actioncode ftype,
 973                      u16 llid, u16 plid)
 974 {
 975         enum plink_event event = PLINK_UNDEFINED;
 976         u8 ie_len = elems->peering_len;
 977         bool matches_local;
 978
 979         matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
 980                          mesh_matches_local(sdata, elems));
 981
 982         /* deny open request from non-matching peer */
 983         if (!matches_local && !sta) {
 984                 event = OPN_RJCT;
 985                 goto out;
 986         }
 987
 988         if (!sta) {
 989                 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
 990                         mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 991                         goto out;
 992                 }
 993                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 994                 if (!mesh_plink_free_count(sdata)) {
 995                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 996                         goto out;
 997                 }
 998
 999                 /* new matching peer */
1000                 event = OPN_ACPT;
1001                 goto out;
1002         } else {
1003                 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1004                         mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1005                         goto out;
1006                 }
1007                 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1008                         goto out;
1009         }
1010
1011         switch (ftype) {
1012         case WLAN_SP_MESH_PEERING_OPEN:
1013                 if (!matches_local)
1014                         event = OPN_RJCT;
1015                 if (!mesh_plink_free_count(sdata) ||
1016                     (sta->mesh->plid && sta->mesh->plid != plid))
1017                         event = OPN_IGNR;
1018                 else
1019                         event = OPN_ACPT;
1020                 break;
1021         case WLAN_SP_MESH_PEERING_CONFIRM:
1022                 if (!matches_local)
1023                         event = CNF_RJCT;
1024                 if (!mesh_plink_free_count(sdata) ||
1025                     sta->mesh->llid != llid ||
1026                     (sta->mesh->plid && sta->mesh->plid != plid))
1027                         event = CNF_IGNR;
1028                 else
1029                         event = CNF_ACPT;
1030                 break;
1031         case WLAN_SP_MESH_PEERING_CLOSE:
1032                 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1033                         /* Do not check for llid or plid. This does not
1034                          * follow the standard but since multiple plinks
1035                          * per sta are not supported, it is necessary in
1036                          * order to avoid a livelock when MP A sees an
1037                          * establish peer link to MP B but MP B does not
1038                          * see it. This can be caused by a timeout in
1039                          * B's peer link establishment or B beign
1040                          * restarted.
1041                          */
1042                         event = CLS_ACPT;
1043                 else if (sta->mesh->plid != plid)
1044                         event = CLS_IGNR;
1045                 else if (ie_len == 8 && sta->mesh->llid != llid)
1046                         event = CLS_IGNR;
1047                 else
1048                         event = CLS_ACPT;
1049                 break;
1050         default:
1051                 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1052                 break;
1053         }
1054
1055 out:
1056         return event;
1057 }
1058
1059 static void
1060 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1061                          struct ieee80211_mgmt *mgmt,
1062                          struct ieee802_11_elems *elems)
1063 {
1064
1065         struct sta_info *sta;
1066         enum plink_event event;
1067         enum ieee80211_self_protected_actioncode ftype;
1068         u32 changed = 0;
1069         u8 ie_len = elems->peering_len;
1070         u16 plid, llid = 0;
1071
1072         if (!elems->peering) {
1073                 mpl_dbg(sdata,
1074                         "Mesh plink: missing necessary peer link ie\n");
1075                 return;
1076         }
1077
1078         if (elems->rsn_len &&
1079             sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1080                 mpl_dbg(sdata,
1081                         "Mesh plink: can't establish link with secure peer\n");
1082                 return;
1083         }
1084
1085         ftype = mgmt->u.action.u.self_prot.action_code;
1086         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1087             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1088             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1089                                                         && ie_len != 8)) {
1090                 mpl_dbg(sdata,
1091                         "Mesh plink: incorrect plink ie length %d %d\n",
1092                         ftype, ie_len);
1093                 return;
1094         }
1095
1096         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1097             (!elems->mesh_id || !elems->mesh_config)) {
1098                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1099                 return;
1100         }
1101         /* Note the lines below are correct, the llid in the frame is the plid
1102          * from the point of view of this host.
1103          */
1104         plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1105         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1106             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1107                 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1108
1109         /* WARNING: Only for sta pointer, is dropped & re-acquired */
1110         rcu_read_lock();
1111
1112         sta = sta_info_get(sdata, mgmt->sa);
1113
1114         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1115             !rssi_threshold_check(sdata, sta)) {
1116                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1117                         mgmt->sa);
1118                 goto unlock_rcu;
1119         }
1120
1121         /* Now we will figure out the appropriate event... */
1122         event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1123
1124         if (event == OPN_ACPT) {
1125                 rcu_read_unlock();
1126                 /* allocate sta entry if necessary and update info */
1127                 sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
1128                 if (!sta) {
1129                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1130                         goto unlock_rcu;
1131                 }
1132                 sta->mesh->plid = plid;
1133         } else if (!sta && event == OPN_RJCT) {
1134                 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1135                                     mgmt->sa, 0, plid,
1136                                     WLAN_REASON_MESH_CONFIG);
1137                 goto unlock_rcu;
1138         } else if (!sta || event == PLINK_UNDEFINED) {
1139                 /* something went wrong */
1140                 goto unlock_rcu;
1141         }
1142
1143         if (event == CNF_ACPT) {
1144                 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1145                 if (!sta->mesh->plid)
1146                         sta->mesh->plid = plid;
1147
1148                 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1149         }
1150
1151         changed |= mesh_plink_fsm(sdata, sta, event);
1152
1153 unlock_rcu:
1154         rcu_read_unlock();
1155
1156         if (changed)
1157                 ieee80211_mbss_info_change_notify(sdata, changed);
1158 }
1159
1160 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1161                          struct ieee80211_mgmt *mgmt, size_t len,
1162                          struct ieee80211_rx_status *rx_status)
1163 {
1164         struct ieee802_11_elems elems;
1165         size_t baselen;
1166         u8 *baseaddr;
1167
1168         /* need action_code, aux */
1169         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1170                 return;
1171
1172         if (sdata->u.mesh.user_mpm)
1173                 /* userspace must register for these */
1174                 return;
1175
1176         if (is_multicast_ether_addr(mgmt->da)) {
1177                 mpl_dbg(sdata,
1178                         "Mesh plink: ignore frame from multicast address\n");
1179                 return;
1180         }
1181
1182         baseaddr = mgmt->u.action.u.self_prot.variable;
1183         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1184         if (mgmt->u.action.u.self_prot.action_code ==
1185                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
1186                 baseaddr += 4;
1187                 baselen += 4;
1188
1189                 if (baselen > len)
1190                         return;
1191         }
1192         ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
1193         mesh_process_plink_frame(sdata, mgmt, &elems);
1194 }