net/mac80211/mesh_plink.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2008, 2009 open80211s Ltd.
   4  * Copyright (C) 2019 Intel Corporation
   5  * Author:     Luis Carlos Cobo <luisca@cozybit.com>
   6  */
   7 #include <linux/gfp.h>
   8 #include <linux/kernel.h>
   9 #include <linux/random.h>
  10 #include <linux/rculist.h>
  11
  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         struct ieee80211_supported_band *sband;
  97         struct sta_info *sta;
  98         u32 erp_rates = 0, changed = 0;
  99         int i;
 100         bool short_slot = false;
 101
 102         sband = ieee80211_get_sband(sdata);
 103         if (!sband)
 104                 return changed;
 105
 106         if (sband->band == NL80211_BAND_5GHZ) {
 107                 /* (IEEE 802.11-2012 19.4.5) */
 108                 short_slot = true;
 109                 goto out;
 110         } else if (sband->band != NL80211_BAND_2GHZ) {
 111                 goto out;
 112         }
 113
 114         for (i = 0; i < sband->n_bitrates; i++)
 115                 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
 116                         erp_rates |= BIT(i);
 117
 118         if (!erp_rates)
 119                 goto out;
 120
 121         rcu_read_lock();
 122         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 123                 if (sdata != sta->sdata ||
 124                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 125                         continue;
 126
 127                 short_slot = false;
 128                 if (erp_rates & sta->sta.supp_rates[sband->band])
 129                         short_slot = true;
 130                  else
 131                         break;
 132         }
 133         rcu_read_unlock();
 134
 135 out:
 136         if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 137                 sdata->vif.bss_conf.use_short_slot = short_slot;
 138                 changed = BSS_CHANGED_ERP_SLOT;
 139                 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 140                         sdata->vif.addr, short_slot);
 141         }
 142         return changed;
 143 }
 144
 145 /**
 146  * mesh_set_ht_prot_mode - set correct HT protection mode
 147  * @sdata: the (mesh) interface to handle
 148  *
 149  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 150  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 151  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 152  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 153  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 154  * HT20 peer is present. Otherwise no-protection mode is selected.
 155  */
 156 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 157 {
 158         struct ieee80211_local *local = sdata->local;
 159         struct sta_info *sta;
 160         u16 ht_opmode;
 161         bool non_ht_sta = false, ht20_sta = false;
 162
 163         switch (sdata->vif.bss_conf.chandef.width) {
 164         case NL80211_CHAN_WIDTH_20_NOHT:
 165         case NL80211_CHAN_WIDTH_5:
 166         case NL80211_CHAN_WIDTH_10:
 167                 return 0;
 168         default:
 169                 break;
 170         }
 171
 172         rcu_read_lock();
 173         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 174                 if (sdata != sta->sdata ||
 175                     sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 176                         continue;
 177
 178                 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
 179                         continue;
 180
 181                 if (!sta->sta.ht_cap.ht_supported) {
 182                         mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
 183                                        sta->sta.addr);
 184                         non_ht_sta = true;
 185                         break;
 186                 }
 187
 188                 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
 189                 ht20_sta = true;
 190         }
 191         rcu_read_unlock();
 192
 193         if (non_ht_sta)
 194                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 195         else if (ht20_sta &&
 196                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 197                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 198         else
 199                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 200
 201         if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
 202                 return 0;
 203
 204         sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 205         sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 206         mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
 207         return BSS_CHANGED_HT;
 208 }
 209
 210 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 211                                struct sta_info *sta,
 212                                enum ieee80211_self_protected_actioncode action,
 213                                u8 *da, u16 llid, u16 plid, u16 reason)
 214 {
 215         struct ieee80211_local *local = sdata->local;
 216         struct sk_buff *skb;
 217         struct ieee80211_tx_info *info;
 218         struct ieee80211_mgmt *mgmt;
 219         bool include_plid = false;
 220         u16 peering_proto = 0;
 221         u8 *pos, ie_len = 4;
 222         u8 ie_len_he_cap;
 223         int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
 224         int err = -ENOMEM;
 225
 226         ie_len_he_cap = ieee80211_ie_len_he_cap(sdata,
 227                                                 NL80211_IFTYPE_MESH_POINT);
 228         skb = dev_alloc_skb(local->tx_headroom +
 229                             hdr_len +
 230                             2 + /* capability info */
 231                             2 + /* AID */
 232                             2 + 8 + /* supported rates */
 233                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 234                             2 + sdata->u.mesh.mesh_id_len +
 235                             2 + sizeof(struct ieee80211_meshconf_ie) +
 236                             2 + sizeof(struct ieee80211_ht_cap) +
 237                             2 + sizeof(struct ieee80211_ht_operation) +
 238                             2 + sizeof(struct ieee80211_vht_cap) +
 239                             2 + sizeof(struct ieee80211_vht_operation) +
 240                             ie_len_he_cap +
 241                             2 + 1 + sizeof(struct ieee80211_he_operation) +
 242                                     sizeof(struct ieee80211_he_6ghz_oper) +
 243                             2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) +
 244                             2 + 8 + /* peering IE */
 245                             sdata->u.mesh.ie_len);
 246         if (!skb)
 247                 return err;
 248         info = IEEE80211_SKB_CB(skb);
 249         skb_reserve(skb, local->tx_headroom);
 250         mgmt = skb_put_zero(skb, hdr_len);
 251         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 252                                           IEEE80211_STYPE_ACTION);
 253         memcpy(mgmt->da, da, ETH_ALEN);
 254         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 255         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 256         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 257         mgmt->u.action.u.self_prot.action_code = action;
 258
 259         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 260                 struct ieee80211_supported_band *sband;
 261                 enum nl80211_band band;
 262
 263                 sband = ieee80211_get_sband(sdata);
 264                 if (!sband) {
 265                         err = -EINVAL;
 266                         goto free;
 267                 }
 268                 band = sband->band;
 269
 270                 /* capability info */
 271                 pos = skb_put_zero(skb, 2);
 272                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 273                         /* AID */
 274                         pos = skb_put(skb, 2);
 275                         put_unaligned_le16(sta->sta.aid, pos);
 276                 }
 277                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 278                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 279                     mesh_add_rsn_ie(sdata, skb) ||
 280                     mesh_add_meshid_ie(sdata, skb) ||
 281                     mesh_add_meshconf_ie(sdata, skb))
 282                         goto free;
 283         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 284                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 285                 if (mesh_add_meshid_ie(sdata, skb))
 286                         goto free;
 287         }
 288
 289         /* Add Mesh Peering Management element */
 290         switch (action) {
 291         case WLAN_SP_MESH_PEERING_OPEN:
 292                 break;
 293         case WLAN_SP_MESH_PEERING_CONFIRM:
 294                 ie_len += 2;
 295                 include_plid = true;
 296                 break;
 297         case WLAN_SP_MESH_PEERING_CLOSE:
 298                 if (plid) {
 299                         ie_len += 2;
 300                         include_plid = true;
 301                 }
 302                 ie_len += 2;    /* reason code */
 303                 break;
 304         default:
 305                 err = -EINVAL;
 306                 goto free;
 307         }
 308
 309         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 310                 goto free;
 311
 312         pos = skb_put(skb, 2 + ie_len);
 313         *pos++ = WLAN_EID_PEER_MGMT;
 314         *pos++ = ie_len;
 315         memcpy(pos, &peering_proto, 2);
 316         pos += 2;
 317         put_unaligned_le16(llid, pos);
 318         pos += 2;
 319         if (include_plid) {
 320                 put_unaligned_le16(plid, pos);
 321                 pos += 2;
 322         }
 323         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 324                 put_unaligned_le16(reason, pos);
 325                 pos += 2;
 326         }
 327
 328         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 329                 if (mesh_add_ht_cap_ie(sdata, skb) ||
 330                     mesh_add_ht_oper_ie(sdata, skb) ||
 331                     mesh_add_vht_cap_ie(sdata, skb) ||
 332                     mesh_add_vht_oper_ie(sdata, skb) ||
 333                     mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) ||
 334                     mesh_add_he_oper_ie(sdata, skb) ||
 335                     mesh_add_he_6ghz_cap_ie(sdata, skb))
 336                         goto free;
 337         }
 338
 339         if (mesh_add_vendor_ies(sdata, skb))
 340                 goto free;
 341
 342         ieee80211_tx_skb(sdata, skb);
 343         return 0;
 344 free:
 345         kfree_skb(skb);
 346         return err;
 347 }
 348
 349 /**
 350  * __mesh_plink_deactivate - deactivate mesh peer link
 351  *
 352  * @sta: mesh peer link to deactivate
 353  *
 354  * Mesh paths with this peer as next hop should be flushed
 355  * by the caller outside of plink_lock.
 356  *
 357  * Returns beacon changed flag if the beacon content changed.
 358  *
 359  * Locking: the caller must hold sta->mesh->plink_lock
 360  */
 361 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 362 {
 363         struct ieee80211_sub_if_data *sdata = sta->sdata;
 364         u32 changed = 0;
 365
 366         lockdep_assert_held(&sta->mesh->plink_lock);
 367
 368         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 369                 changed = mesh_plink_dec_estab_count(sdata);
 370         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 371
 372         ieee80211_mps_sta_status_update(sta);
 373         changed |= ieee80211_mps_set_sta_local_pm(sta,
 374                         NL80211_MESH_POWER_UNKNOWN);
 375
 376         return changed;
 377 }
 378
 379 /**
 380  * mesh_plink_deactivate - deactivate mesh peer link
 381  *
 382  * @sta: mesh peer link to deactivate
 383  *
 384  * All mesh paths with this peer as next hop will be flushed
 385  */
 386 u32 mesh_plink_deactivate(struct sta_info *sta)
 387 {
 388         struct ieee80211_sub_if_data *sdata = sta->sdata;
 389         u32 changed;
 390
 391         spin_lock_bh(&sta->mesh->plink_lock);
 392         changed = __mesh_plink_deactivate(sta);
 393
 394         if (!sdata->u.mesh.user_mpm) {
 395                 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
 396                 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
 397                                     sta->sta.addr, sta->mesh->llid,
 398                                     sta->mesh->plid, sta->mesh->reason);
 399         }
 400         spin_unlock_bh(&sta->mesh->plink_lock);
 401         if (!sdata->u.mesh.user_mpm)
 402                 del_timer_sync(&sta->mesh->plink_timer);
 403         mesh_path_flush_by_nexthop(sta);
 404
 405         /* make sure no readers can access nexthop sta from here on */
 406         synchronize_net();
 407
 408         return changed;
 409 }
 410
 411 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 412                                struct sta_info *sta,
 413                                struct ieee802_11_elems *elems)
 414 {
 415         struct ieee80211_local *local = sdata->local;
 416         struct ieee80211_supported_band *sband;
 417         u32 rates, basic_rates = 0, changed = 0;
 418         enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
 419
 420         sband = ieee80211_get_sband(sdata);
 421         if (!sband)
 422                 return;
 423
 424         rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
 425                                         &basic_rates);
 426
 427         spin_lock_bh(&sta->mesh->plink_lock);
 428         sta->rx_stats.last_rx = jiffies;
 429
 430         /* rates and capabilities don't change during peering */
 431         if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
 432             sta->mesh->processed_beacon)
 433                 goto out;
 434         sta->mesh->processed_beacon = true;
 435
 436         if (sta->sta.supp_rates[sband->band] != rates)
 437                 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 438         sta->sta.supp_rates[sband->band] = rates;
 439
 440         if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 441                                               elems->ht_cap_elem, sta))
 442                 changed |= IEEE80211_RC_BW_CHANGED;
 443
 444         ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
 445                                             elems->vht_cap_elem, sta);
 446
 447         ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap,
 448                                           elems->he_cap_len,
 449                                           elems->he_6ghz_capa,
 450                                           sta);
 451
 452         if (bw != sta->sta.bandwidth)
 453                 changed |= IEEE80211_RC_BW_CHANGED;
 454
 455         /* HT peer is operating 20MHz-only */
 456         if (elems->ht_operation &&
 457             !(elems->ht_operation->ht_param &
 458               IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 459                 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 460                         changed |= IEEE80211_RC_BW_CHANGED;
 461                 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 462         }
 463
 464         if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
 465                 rate_control_rate_init(sta);
 466         else
 467                 rate_control_rate_update(local, sband, sta, changed);
 468 out:
 469         spin_unlock_bh(&sta->mesh->plink_lock);
 470 }
 471
 472 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
 473 {
 474         struct sta_info *sta;
 475         unsigned long *aid_map;
 476         int aid;
 477
 478         aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
 479                           sizeof(*aid_map), GFP_KERNEL);
 480         if (!aid_map)
 481                 return -ENOMEM;
 482
 483         /* reserve aid 0 for mcast indication */
 484         __set_bit(0, aid_map);
 485
 486         rcu_read_lock();
 487         list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
 488                 __set_bit(sta->sta.aid, aid_map);
 489         rcu_read_unlock();
 490
 491         aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
 492         kfree(aid_map);
 493
 494         if (aid > IEEE80211_MAX_AID)
 495                 return -ENOBUFS;
 496
 497         return aid;
 498 }
 499
 500 static struct sta_info *
 501 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 502 {
 503         struct sta_info *sta;
 504         int aid;
 505
 506         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 507                 return NULL;
 508
 509         aid = mesh_allocate_aid(sdata);
 510         if (aid < 0)
 511                 return NULL;
 512
 513         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 514         if (!sta)
 515                 return NULL;
 516
 517         sta->mesh->plink_state = NL80211_PLINK_LISTEN;
 518         sta->sta.wme = true;
 519         sta->sta.aid = aid;
 520
 521         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 522         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 523         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 524
 525         return sta;
 526 }
 527
 528 static struct sta_info *
 529 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 530                     struct ieee802_11_elems *elems,
 531                     struct ieee80211_rx_status *rx_status)
 532 {
 533         struct sta_info *sta = NULL;
 534
 535         /* Userspace handles station allocation */
 536         if (sdata->u.mesh.user_mpm ||
 537             sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
 538                 if (mesh_peer_accepts_plinks(elems) &&
 539                     mesh_plink_availables(sdata)) {
 540                         int sig = 0;
 541
 542                         if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
 543                                 sig = rx_status->signal;
 544
 545                         cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 546                                                            elems->ie_start,
 547                                                            elems->total_len,
 548                                                            sig, GFP_KERNEL);
 549                 }
 550         } else
 551                 sta = __mesh_sta_info_alloc(sdata, addr);
 552
 553         return sta;
 554 }
 555
 556 /*
 557  * mesh_sta_info_get - return mesh sta info entry for @addr.
 558  *
 559  * @sdata: local meshif
 560  * @addr: peer's address
 561  * @elems: IEs from beacon or mesh peering frame.
 562  * @rx_status: rx status for the frame for signal reporting
 563  *
 564  * Return existing or newly allocated sta_info under RCU read lock.
 565  * (re)initialize with given IEs.
 566  */
 567 static struct sta_info *
 568 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 569                   u8 *addr, struct ieee802_11_elems *elems,
 570                   struct ieee80211_rx_status *rx_status) __acquires(RCU)
 571 {
 572         struct sta_info *sta = NULL;
 573
 574         rcu_read_lock();
 575         sta = sta_info_get(sdata, addr);
 576         if (sta) {
 577                 mesh_sta_info_init(sdata, sta, elems);
 578         } else {
 579                 rcu_read_unlock();
 580                 /* can't run atomic */
 581                 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
 582                 if (!sta) {
 583                         rcu_read_lock();
 584                         return NULL;
 585                 }
 586
 587                 mesh_sta_info_init(sdata, sta, elems);
 588
 589                 if (sta_info_insert_rcu(sta))
 590                         return NULL;
 591         }
 592
 593         return sta;
 594 }
 595
 596 /*
 597  * mesh_neighbour_update - update or initialize new mesh neighbor.
 598  *
 599  * @sdata: local meshif
 600  * @addr: peer's address
 601  * @elems: IEs from beacon or mesh peering frame
 602  * @rx_status: rx status for the frame for signal reporting
 603  *
 604  * Initiates peering if appropriate.
 605  */
 606 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 607                            u8 *hw_addr,
 608                            struct ieee802_11_elems *elems,
 609                            struct ieee80211_rx_status *rx_status)
 610 {
 611         struct sta_info *sta;
 612         u32 changed = 0;
 613
 614         sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
 615         if (!sta)
 616                 goto out;
 617
 618         sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
 619                 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
 620
 621         if (mesh_peer_accepts_plinks(elems) &&
 622             sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
 623             sdata->u.mesh.accepting_plinks &&
 624             sdata->u.mesh.mshcfg.auto_open_plinks &&
 625             rssi_threshold_check(sdata, sta))
 626                 changed = mesh_plink_open(sta);
 627
 628         ieee80211_mps_frame_release(sta, elems);
 629 out:
 630         rcu_read_unlock();
 631         ieee80211_mbss_info_change_notify(sdata, changed);
 632 }
 633
 634 void mesh_plink_timer(struct timer_list *t)
 635 {
 636         struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
 637         struct sta_info *sta;
 638         u16 reason = 0;
 639         struct ieee80211_sub_if_data *sdata;
 640         struct mesh_config *mshcfg;
 641         enum ieee80211_self_protected_actioncode action = 0;
 642
 643         /*
 644          * This STA is valid because sta_info_destroy() will
 645          * del_timer_sync() this timer after having made sure
 646          * it cannot be readded (by deleting the plink.)
 647          */
 648         sta = mesh->plink_sta;
 649
 650         if (sta->sdata->local->quiescing)
 651                 return;
 652
 653         spin_lock_bh(&sta->mesh->plink_lock);
 654
 655         /* If a timer fires just before a state transition on another CPU,
 656          * we may have already extended the timeout and changed state by the
 657          * time we've acquired the lock and arrived  here.  In that case,
 658          * skip this timer and wait for the new one.
 659          */
 660         if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
 661                 mpl_dbg(sta->sdata,
 662                         "Ignoring timer for %pM in state %s (timer adjusted)",
 663                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 664                 spin_unlock_bh(&sta->mesh->plink_lock);
 665                 return;
 666         }
 667
 668         /* del_timer() and handler may race when entering these states */
 669         if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
 670             sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
 671                 mpl_dbg(sta->sdata,
 672                         "Ignoring timer for %pM in state %s (timer deleted)",
 673                         sta->sta.addr, mplstates[sta->mesh->plink_state]);
 674                 spin_unlock_bh(&sta->mesh->plink_lock);
 675                 return;
 676         }
 677
 678         mpl_dbg(sta->sdata,
 679                 "Mesh plink timer for %pM fired on state %s\n",
 680                 sta->sta.addr, mplstates[sta->mesh->plink_state]);
 681         sdata = sta->sdata;
 682         mshcfg = &sdata->u.mesh.mshcfg;
 683
 684         switch (sta->mesh->plink_state) {
 685         case NL80211_PLINK_OPN_RCVD:
 686         case NL80211_PLINK_OPN_SNT:
 687                 /* retry timer */
 688                 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
 689                         u32 rand;
 690                         mpl_dbg(sta->sdata,
 691                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 692                                 sta->sta.addr, sta->mesh->plink_retries,
 693                                 sta->mesh->plink_timeout);
 694                         get_random_bytes(&rand, sizeof(u32));
 695                         sta->mesh->plink_timeout = sta->mesh->plink_timeout +
 696                                              rand % sta->mesh->plink_timeout;
 697                         ++sta->mesh->plink_retries;
 698                         mod_plink_timer(sta, sta->mesh->plink_timeout);
 699                         action = WLAN_SP_MESH_PEERING_OPEN;
 700                         break;
 701                 }
 702                 reason = WLAN_REASON_MESH_MAX_RETRIES;
 703                 fallthrough;
 704         case NL80211_PLINK_CNF_RCVD:
 705                 /* confirm timer */
 706                 if (!reason)
 707                         reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
 708                 sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 709                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 710                 action = WLAN_SP_MESH_PEERING_CLOSE;
 711                 break;
 712         case NL80211_PLINK_HOLDING:
 713                 /* holding timer */
 714                 del_timer(&sta->mesh->plink_timer);
 715                 mesh_plink_fsm_restart(sta);
 716                 break;
 717         default:
 718                 break;
 719         }
 720         spin_unlock_bh(&sta->mesh->plink_lock);
 721         if (action)
 722                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 723                                     sta->mesh->llid, sta->mesh->plid, reason);
 724 }
 725
 726 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
 727 {
 728         sta->mesh->plink_timeout = timeout;
 729         mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
 730 }
 731
 732 static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
 733                         u16 llid)
 734 {
 735         struct ieee80211_local *local = sdata->local;
 736         bool in_use = false;
 737         struct sta_info *sta;
 738
 739         rcu_read_lock();
 740         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 741                 if (sdata != sta->sdata)
 742                         continue;
 743
 744                 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
 745                         in_use = true;
 746                         break;
 747                 }
 748         }
 749         rcu_read_unlock();
 750
 751         return in_use;
 752 }
 753
 754 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
 755 {
 756         u16 llid;
 757
 758         do {
 759                 get_random_bytes(&llid, sizeof(llid));
 760         } while (llid_in_use(sdata, llid));
 761
 762         return llid;
 763 }
 764
 765 u32 mesh_plink_open(struct sta_info *sta)
 766 {
 767         struct ieee80211_sub_if_data *sdata = sta->sdata;
 768         u32 changed;
 769
 770         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 771                 return 0;
 772
 773         spin_lock_bh(&sta->mesh->plink_lock);
 774         sta->mesh->llid = mesh_get_new_llid(sdata);
 775         if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
 776             sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
 777                 spin_unlock_bh(&sta->mesh->plink_lock);
 778                 return 0;
 779         }
 780         sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
 781         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 782         spin_unlock_bh(&sta->mesh->plink_lock);
 783         mpl_dbg(sdata,
 784                 "Mesh plink: starting establishment with %pM\n",
 785                 sta->sta.addr);
 786
 787         /* set the non-peer mode to active during peering */
 788         changed = ieee80211_mps_local_status_update(sdata);
 789
 790         mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
 791                             sta->sta.addr, sta->mesh->llid, 0, 0);
 792         return changed;
 793 }
 794
 795 u32 mesh_plink_block(struct sta_info *sta)
 796 {
 797         u32 changed;
 798
 799         spin_lock_bh(&sta->mesh->plink_lock);
 800         changed = __mesh_plink_deactivate(sta);
 801         sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 802         spin_unlock_bh(&sta->mesh->plink_lock);
 803         mesh_path_flush_by_nexthop(sta);
 804
 805         return changed;
 806 }
 807
 808 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
 809                              struct sta_info *sta,
 810                              enum plink_event event)
 811 {
 812         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 813         u16 reason = (event == CLS_ACPT) ?
 814                      WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
 815
 816         sta->mesh->reason = reason;
 817         sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 818         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 819 }
 820
 821 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
 822                                 struct sta_info *sta)
 823 {
 824         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 825         u32 changed = 0;
 826
 827         del_timer(&sta->mesh->plink_timer);
 828         sta->mesh->plink_state = NL80211_PLINK_ESTAB;
 829         changed |= mesh_plink_inc_estab_count(sdata);
 830         changed |= mesh_set_ht_prot_mode(sdata);
 831         changed |= mesh_set_short_slot_time(sdata);
 832         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
 833         ieee80211_mps_sta_status_update(sta);
 834         changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
 835         return changed;
 836 }
 837
 838 /**
 839  * mesh_plink_fsm - step @sta MPM based on @event
 840  *
 841  * @sdata: interface
 842  * @sta: mesh neighbor
 843  * @event: peering event
 844  *
 845  * Return: changed MBSS flags
 846  */
 847 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
 848                           struct sta_info *sta, enum plink_event event)
 849 {
 850         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 851         enum ieee80211_self_protected_actioncode action = 0;
 852         u32 changed = 0;
 853         bool flush = false;
 854
 855         mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
 856                 mplstates[sta->mesh->plink_state], mplevents[event]);
 857
 858         spin_lock_bh(&sta->mesh->plink_lock);
 859         switch (sta->mesh->plink_state) {
 860         case NL80211_PLINK_LISTEN:
 861                 switch (event) {
 862                 case CLS_ACPT:
 863                         mesh_plink_fsm_restart(sta);
 864                         break;
 865                 case OPN_ACPT:
 866                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 867                         sta->mesh->llid = mesh_get_new_llid(sdata);
 868                         mesh_plink_timer_set(sta,
 869                                              mshcfg->dot11MeshRetryTimeout);
 870
 871                         /* set the non-peer mode to active during peering */
 872                         changed |= ieee80211_mps_local_status_update(sdata);
 873                         action = WLAN_SP_MESH_PEERING_OPEN;
 874                         break;
 875                 default:
 876                         break;
 877                 }
 878                 break;
 879         case NL80211_PLINK_OPN_SNT:
 880                 switch (event) {
 881                 case OPN_RJCT:
 882                 case CNF_RJCT:
 883                 case CLS_ACPT:
 884                         mesh_plink_close(sdata, sta, event);
 885                         action = WLAN_SP_MESH_PEERING_CLOSE;
 886                         break;
 887                 case OPN_ACPT:
 888                         /* retry timer is left untouched */
 889                         sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 890                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 891                         break;
 892                 case CNF_ACPT:
 893                         sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
 894                         mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
 895                         break;
 896                 default:
 897                         break;
 898                 }
 899                 break;
 900         case NL80211_PLINK_OPN_RCVD:
 901                 switch (event) {
 902                 case OPN_RJCT:
 903                 case CNF_RJCT:
 904                 case CLS_ACPT:
 905                         mesh_plink_close(sdata, sta, event);
 906                         action = WLAN_SP_MESH_PEERING_CLOSE;
 907                         break;
 908                 case OPN_ACPT:
 909                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 910                         break;
 911                 case CNF_ACPT:
 912                         changed |= mesh_plink_establish(sdata, sta);
 913                         break;
 914                 default:
 915                         break;
 916                 }
 917                 break;
 918         case NL80211_PLINK_CNF_RCVD:
 919                 switch (event) {
 920                 case OPN_RJCT:
 921                 case CNF_RJCT:
 922                 case CLS_ACPT:
 923                         mesh_plink_close(sdata, sta, event);
 924                         action = WLAN_SP_MESH_PEERING_CLOSE;
 925                         break;
 926                 case OPN_ACPT:
 927                         changed |= mesh_plink_establish(sdata, sta);
 928                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 929                         break;
 930                 default:
 931                         break;
 932                 }
 933                 break;
 934         case NL80211_PLINK_ESTAB:
 935                 switch (event) {
 936                 case CLS_ACPT:
 937                         changed |= __mesh_plink_deactivate(sta);
 938                         changed |= mesh_set_ht_prot_mode(sdata);
 939                         changed |= mesh_set_short_slot_time(sdata);
 940                         mesh_plink_close(sdata, sta, event);
 941                         action = WLAN_SP_MESH_PEERING_CLOSE;
 942                         flush = true;
 943                         break;
 944                 case OPN_ACPT:
 945                         action = WLAN_SP_MESH_PEERING_CONFIRM;
 946                         break;
 947                 default:
 948                         break;
 949                 }
 950                 break;
 951         case NL80211_PLINK_HOLDING:
 952                 switch (event) {
 953                 case CLS_ACPT:
 954                         del_timer(&sta->mesh->plink_timer);
 955                         mesh_plink_fsm_restart(sta);
 956                         break;
 957                 case OPN_ACPT:
 958                 case CNF_ACPT:
 959                 case OPN_RJCT:
 960                 case CNF_RJCT:
 961                         action = WLAN_SP_MESH_PEERING_CLOSE;
 962                         break;
 963                 default:
 964                         break;
 965                 }
 966                 break;
 967         default:
 968                 /* should not get here, PLINK_BLOCKED is dealt with at the
 969                  * beginning of the function
 970                  */
 971                 break;
 972         }
 973         spin_unlock_bh(&sta->mesh->plink_lock);
 974         if (flush)
 975                 mesh_path_flush_by_nexthop(sta);
 976         if (action) {
 977                 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 978                                     sta->mesh->llid, sta->mesh->plid,
 979                                     sta->mesh->reason);
 980
 981                 /* also send confirm in open case */
 982                 if (action == WLAN_SP_MESH_PEERING_OPEN) {
 983                         mesh_plink_frame_tx(sdata, sta,
 984                                             WLAN_SP_MESH_PEERING_CONFIRM,
 985                                             sta->sta.addr, sta->mesh->llid,
 986                                             sta->mesh->plid, 0);
 987                 }
 988         }
 989
 990         return changed;
 991 }
 992
 993 /*
 994  * mesh_plink_get_event - get correct MPM event
 995  *
 996  * @sdata: interface
 997  * @sta: peer, leave NULL if processing a frame from a new suitable peer
 998  * @elems: peering management IEs
 999  * @ftype: frame type
1000  * @llid: peer's peer link ID
1001  * @plid: peer's local link ID
1002  *
1003  * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
1004  * an error.
1005  */
1006 static enum plink_event
1007 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1008                      struct sta_info *sta,
1009                      struct ieee802_11_elems *elems,
1010                      enum ieee80211_self_protected_actioncode ftype,
1011                      u16 llid, u16 plid)
1012 {
1013         enum plink_event event = PLINK_UNDEFINED;
1014         u8 ie_len = elems->peering_len;
1015         bool matches_local;
1016
1017         matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1018                          mesh_matches_local(sdata, elems));
1019
1020         /* deny open request from non-matching peer */
1021         if (!matches_local && !sta) {
1022                 event = OPN_RJCT;
1023                 goto out;
1024         }
1025
1026         if (!sta) {
1027                 if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1028                         mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1029                         goto out;
1030                 }
1031                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
1032                 if (!mesh_plink_free_count(sdata)) {
1033                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1034                         goto out;
1035                 }
1036
1037                 /* new matching peer */
1038                 event = OPN_ACPT;
1039                 goto out;
1040         } else {
1041                 if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1042                         mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1043                         goto out;
1044                 }
1045                 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1046                         goto out;
1047         }
1048
1049         switch (ftype) {
1050         case WLAN_SP_MESH_PEERING_OPEN:
1051                 if (!matches_local)
1052                         event = OPN_RJCT;
1053                 if (!mesh_plink_free_count(sdata) ||
1054                     (sta->mesh->plid && sta->mesh->plid != plid))
1055                         event = OPN_IGNR;
1056                 else
1057                         event = OPN_ACPT;
1058                 break;
1059         case WLAN_SP_MESH_PEERING_CONFIRM:
1060                 if (!matches_local)
1061                         event = CNF_RJCT;
1062                 if (!mesh_plink_free_count(sdata) ||
1063                     sta->mesh->llid != llid ||
1064                     (sta->mesh->plid && sta->mesh->plid != plid))
1065                         event = CNF_IGNR;
1066                 else
1067                         event = CNF_ACPT;
1068                 break;
1069         case WLAN_SP_MESH_PEERING_CLOSE:
1070                 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1071                         /* Do not check for llid or plid. This does not
1072                          * follow the standard but since multiple plinks
1073                          * per sta are not supported, it is necessary in
1074                          * order to avoid a livelock when MP A sees an
1075                          * establish peer link to MP B but MP B does not
1076                          * see it. This can be caused by a timeout in
1077                          * B's peer link establishment or B beign
1078                          * restarted.
1079                          */
1080                         event = CLS_ACPT;
1081                 else if (sta->mesh->plid != plid)
1082                         event = CLS_IGNR;
1083                 else if (ie_len == 8 && sta->mesh->llid != llid)
1084                         event = CLS_IGNR;
1085                 else
1086                         event = CLS_ACPT;
1087                 break;
1088         default:
1089                 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1090                 break;
1091         }
1092
1093 out:
1094         return event;
1095 }
1096
1097 static void
1098 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1099                          struct ieee80211_mgmt *mgmt,
1100                          struct ieee802_11_elems *elems,
1101                          struct ieee80211_rx_status *rx_status)
1102 {
1103
1104         struct sta_info *sta;
1105         enum plink_event event;
1106         enum ieee80211_self_protected_actioncode ftype;
1107         u32 changed = 0;
1108         u8 ie_len = elems->peering_len;
1109         u16 plid, llid = 0;
1110
1111         if (!elems->peering) {
1112                 mpl_dbg(sdata,
1113                         "Mesh plink: missing necessary peer link ie\n");
1114                 return;
1115         }
1116
1117         if (elems->rsn_len &&
1118             sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1119                 mpl_dbg(sdata,
1120                         "Mesh plink: can't establish link with secure peer\n");
1121                 return;
1122         }
1123
1124         ftype = mgmt->u.action.u.self_prot.action_code;
1125         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1126             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1127             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1128                                                         && ie_len != 8)) {
1129                 mpl_dbg(sdata,
1130                         "Mesh plink: incorrect plink ie length %d %d\n",
1131                         ftype, ie_len);
1132                 return;
1133         }
1134
1135         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1136             (!elems->mesh_id || !elems->mesh_config)) {
1137                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1138                 return;
1139         }
1140         /* Note the lines below are correct, the llid in the frame is the plid
1141          * from the point of view of this host.
1142          */
1143         plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1144         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1145             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1146                 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1147
1148         /* WARNING: Only for sta pointer, is dropped & re-acquired */
1149         rcu_read_lock();
1150
1151         sta = sta_info_get(sdata, mgmt->sa);
1152
1153         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1154             !rssi_threshold_check(sdata, sta)) {
1155                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1156                         mgmt->sa);
1157                 goto unlock_rcu;
1158         }
1159
1160         /* Now we will figure out the appropriate event... */
1161         event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1162
1163         if (event == OPN_ACPT) {
1164                 rcu_read_unlock();
1165                 /* allocate sta entry if necessary and update info */
1166                 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1167                 if (!sta) {
1168                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1169                         goto unlock_rcu;
1170                 }
1171                 sta->mesh->plid = plid;
1172         } else if (!sta && event == OPN_RJCT) {
1173                 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1174                                     mgmt->sa, 0, plid,
1175                                     WLAN_REASON_MESH_CONFIG);
1176                 goto unlock_rcu;
1177         } else if (!sta || event == PLINK_UNDEFINED) {
1178                 /* something went wrong */
1179                 goto unlock_rcu;
1180         }
1181
1182         if (event == CNF_ACPT) {
1183                 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1184                 if (!sta->mesh->plid)
1185                         sta->mesh->plid = plid;
1186
1187                 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1188         }
1189
1190         changed |= mesh_plink_fsm(sdata, sta, event);
1191
1192 unlock_rcu:
1193         rcu_read_unlock();
1194
1195         if (changed)
1196                 ieee80211_mbss_info_change_notify(sdata, changed);
1197 }
1198
1199 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1200                          struct ieee80211_mgmt *mgmt, size_t len,
1201                          struct ieee80211_rx_status *rx_status)
1202 {
1203         struct ieee802_11_elems elems;
1204         size_t baselen;
1205         u8 *baseaddr;
1206
1207         /* need action_code, aux */
1208         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1209                 return;
1210
1211         if (sdata->u.mesh.user_mpm)
1212                 /* userspace must register for these */
1213                 return;
1214
1215         if (is_multicast_ether_addr(mgmt->da)) {
1216                 mpl_dbg(sdata,
1217                         "Mesh plink: ignore frame from multicast address\n");
1218                 return;
1219         }
1220
1221         baseaddr = mgmt->u.action.u.self_prot.variable;
1222         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1223         if (mgmt->u.action.u.self_prot.action_code ==
1224                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
1225                 baseaddr += 4;
1226                 baselen += 4;
1227
1228                 if (baselen > len)
1229                         return;
1230         }
1231         ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems,
1232                                mgmt->bssid, NULL);
1233         mesh_process_plink_frame(sdata, mgmt, &elems, rx_status);
1234 }