net/mac80211/mesh_plink.c

   1 /*
   2  * Copyright (c) 2008, 2009 open80211s Ltd.
   3  * Author:     Luis Carlos Cobo <luisca@cozybit.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9 #include <linux/gfp.h>
  10 #include <linux/kernel.h>
  11 #include <linux/random.h>
  12 #include "ieee80211_i.h"
  13 #include "rate.h"
  14 #include "mesh.h"
  15
  16 #define PLINK_GET_LLID(p) (p + 2)
  17 #define PLINK_GET_PLID(p) (p + 4)
  18
  19 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
  20                                 jiffies + HZ * t / 1000))
  21
  22 /* We only need a valid sta if user configured a minimum rssi_threshold. */
  23 #define rssi_threshold_check(sta, sdata) \
  24                 (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
  25                 (sta && (s8) -ewma_read(&sta->avg_signal) > \
  26                 sdata->u.mesh.mshcfg.rssi_threshold))
  27
  28 enum plink_event {
  29         PLINK_UNDEFINED,
  30         OPN_ACPT,
  31         OPN_RJCT,
  32         OPN_IGNR,
  33         CNF_ACPT,
  34         CNF_RJCT,
  35         CNF_IGNR,
  36         CLS_ACPT,
  37         CLS_IGNR
  38 };
  39
  40 static const char * const mplstates[] = {
  41         [NL80211_PLINK_LISTEN] = "LISTEN",
  42         [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
  43         [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
  44         [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
  45         [NL80211_PLINK_ESTAB] = "ESTAB",
  46         [NL80211_PLINK_HOLDING] = "HOLDING",
  47         [NL80211_PLINK_BLOCKED] = "BLOCKED"
  48 };
  49
  50 static const char * const mplevents[] = {
  51         [PLINK_UNDEFINED] = "NONE",
  52         [OPN_ACPT] = "OPN_ACPT",
  53         [OPN_RJCT] = "OPN_RJCT",
  54         [OPN_IGNR] = "OPN_IGNR",
  55         [CNF_ACPT] = "CNF_ACPT",
  56         [CNF_RJCT] = "CNF_RJCT",
  57         [CNF_IGNR] = "CNF_IGNR",
  58         [CLS_ACPT] = "CLS_ACPT",
  59         [CLS_IGNR] = "CLS_IGNR"
  60 };
  61
  62 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
  63                                enum ieee80211_self_protected_actioncode action,
  64                                u8 *da, __le16 llid, __le16 plid, __le16 reason);
  65
  66 /**
  67  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  68  *
  69  * @sta: mesh peer link to restart
  70  *
  71  * Locking: this function must be called holding sta->lock
  72  */
  73 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  74 {
  75         sta->plink_state = NL80211_PLINK_LISTEN;
  76         sta->llid = sta->plid = sta->reason = 0;
  77         sta->plink_retries = 0;
  78 }
  79
  80 /*
  81  * mesh_set_short_slot_time - enable / disable ERP short slot time.
  82  *
  83  * The standard indirectly mandates mesh STAs to turn off short slot time by
  84  * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
  85  * can't be sneaky about it. Enable short slot time if all mesh STAs in the
  86  * MBSS support ERP rates.
  87  *
  88  * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
  89  */
  90 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
  91 {
  92         struct ieee80211_local *local = sdata->local;
  93         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
  94         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
  95         struct sta_info *sta;
  96         u32 erp_rates = 0, changed = 0;
  97         int i;
  98         bool short_slot = false;
  99
 100         if (band == IEEE80211_BAND_5GHZ) {
 101                 /* (IEEE 802.11-2012 19.4.5) */
 102                 short_slot = true;
 103                 goto out;
 104         } else if (band != IEEE80211_BAND_2GHZ ||
 105                    (band == IEEE80211_BAND_2GHZ &&
 106                     local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
 107                 goto out;
 108
 109         for (i = 0; i < sband->n_bitrates; i++)
 110                 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
 111                         erp_rates |= BIT(i);
 112
 113         if (!erp_rates)
 114                 goto out;
 115
 116         rcu_read_lock();
 117         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 118                 if (sdata != sta->sdata ||
 119                     sta->plink_state != NL80211_PLINK_ESTAB)
 120                         continue;
 121
 122                 short_slot = false;
 123                 if (erp_rates & sta->sta.supp_rates[band])
 124                         short_slot = true;
 125                  else
 126                         break;
 127         }
 128         rcu_read_unlock();
 129
 130 out:
 131         if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 132                 sdata->vif.bss_conf.use_short_slot = short_slot;
 133                 changed = BSS_CHANGED_ERP_SLOT;
 134                 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 135                         sdata->vif.addr, short_slot);
 136         }
 137         return changed;
 138 }
 139
 140 /**
 141  * mesh_set_ht_prot_mode - set correct HT protection mode
 142  *
 143  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 144  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 145  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 146  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 147  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 148  * HT20 peer is present. Otherwise no-protection mode is selected.
 149  */
 150 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 151 {
 152         struct ieee80211_local *local = sdata->local;
 153         struct sta_info *sta;
 154         u16 ht_opmode;
 155         bool non_ht_sta = false, ht20_sta = false;
 156
 157         switch (sdata->vif.bss_conf.chandef.width) {
 158         case NL80211_CHAN_WIDTH_20_NOHT:
 159         case NL80211_CHAN_WIDTH_5:
 160         case NL80211_CHAN_WIDTH_10:
 161                 return 0;
 162         default:
 163                 break;
 164         }
 165
 166         rcu_read_lock();
 167         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 168                 if (sdata != sta->sdata ||
 169                     sta->plink_state != NL80211_PLINK_ESTAB)
 170                         continue;
 171
 172                 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
 173                         continue;
 174
 175                 if (!sta->sta.ht_cap.ht_supported) {
 176                         mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
 177                                        sta->sta.addr);
 178                         non_ht_sta = true;
 179                         break;
 180                 }
 181
 182                 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
 183                 ht20_sta = true;
 184         }
 185         rcu_read_unlock();
 186
 187         if (non_ht_sta)
 188                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 189         else if (ht20_sta &&
 190                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 191                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 192         else
 193                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 194
 195         if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
 196                 return 0;
 197
 198         sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 199         sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 200         mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
 201         return BSS_CHANGED_HT;
 202 }
 203
 204 /**
 205  * __mesh_plink_deactivate - deactivate mesh peer link
 206  *
 207  * @sta: mesh peer link to deactivate
 208  *
 209  * All mesh paths with this peer as next hop will be flushed
 210  * Returns beacon changed flag if the beacon content changed.
 211  *
 212  * Locking: the caller must hold sta->lock
 213  */
 214 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 215 {
 216         struct ieee80211_sub_if_data *sdata = sta->sdata;
 217         u32 changed = 0;
 218
 219         if (sta->plink_state == NL80211_PLINK_ESTAB)
 220                 changed = mesh_plink_dec_estab_count(sdata);
 221         sta->plink_state = NL80211_PLINK_BLOCKED;
 222         mesh_path_flush_by_nexthop(sta);
 223
 224         ieee80211_mps_sta_status_update(sta);
 225         changed |= ieee80211_mps_local_status_update(sdata);
 226
 227         return changed;
 228 }
 229
 230 /**
 231  * mesh_plink_deactivate - deactivate mesh peer link
 232  *
 233  * @sta: mesh peer link to deactivate
 234  *
 235  * All mesh paths with this peer as next hop will be flushed
 236  */
 237 u32 mesh_plink_deactivate(struct sta_info *sta)
 238 {
 239         struct ieee80211_sub_if_data *sdata = sta->sdata;
 240         u32 changed;
 241
 242         spin_lock_bh(&sta->lock);
 243         changed = __mesh_plink_deactivate(sta);
 244         sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 245         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 246                             sta->sta.addr, sta->llid, sta->plid,
 247                             sta->reason);
 248         spin_unlock_bh(&sta->lock);
 249
 250         return changed;
 251 }
 252
 253 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 254                                enum ieee80211_self_protected_actioncode action,
 255                                u8 *da, __le16 llid, __le16 plid, __le16 reason)
 256 {
 257         struct ieee80211_local *local = sdata->local;
 258         struct sk_buff *skb;
 259         struct ieee80211_tx_info *info;
 260         struct ieee80211_mgmt *mgmt;
 261         bool include_plid = false;
 262         u16 peering_proto = 0;
 263         u8 *pos, ie_len = 4;
 264         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 265                       sizeof(mgmt->u.action.u.self_prot);
 266         int err = -ENOMEM;
 267
 268         skb = dev_alloc_skb(local->tx_headroom +
 269                             hdr_len +
 270                             2 + /* capability info */
 271                             2 + /* AID */
 272                             2 + 8 + /* supported rates */
 273                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 274                             2 + sdata->u.mesh.mesh_id_len +
 275                             2 + sizeof(struct ieee80211_meshconf_ie) +
 276                             2 + sizeof(struct ieee80211_ht_cap) +
 277                             2 + sizeof(struct ieee80211_ht_operation) +
 278                             2 + 8 + /* peering IE */
 279                             sdata->u.mesh.ie_len);
 280         if (!skb)
 281                 return -1;
 282         info = IEEE80211_SKB_CB(skb);
 283         skb_reserve(skb, local->tx_headroom);
 284         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 285         memset(mgmt, 0, hdr_len);
 286         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 287                                           IEEE80211_STYPE_ACTION);
 288         memcpy(mgmt->da, da, ETH_ALEN);
 289         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 290         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 291         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 292         mgmt->u.action.u.self_prot.action_code = action;
 293
 294         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 295                 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 296
 297                 /* capability info */
 298                 pos = skb_put(skb, 2);
 299                 memset(pos, 0, 2);
 300                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 301                         /* AID */
 302                         pos = skb_put(skb, 2);
 303                         memcpy(pos + 2, &plid, 2);
 304                 }
 305                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 306                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 307                     mesh_add_rsn_ie(sdata, skb) ||
 308                     mesh_add_meshid_ie(sdata, skb) ||
 309                     mesh_add_meshconf_ie(sdata, skb))
 310                         goto free;
 311         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 312                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 313                 if (mesh_add_meshid_ie(sdata, skb))
 314                         goto free;
 315         }
 316
 317         /* Add Mesh Peering Management element */
 318         switch (action) {
 319         case WLAN_SP_MESH_PEERING_OPEN:
 320                 break;
 321         case WLAN_SP_MESH_PEERING_CONFIRM:
 322                 ie_len += 2;
 323                 include_plid = true;
 324                 break;
 325         case WLAN_SP_MESH_PEERING_CLOSE:
 326                 if (plid) {
 327                         ie_len += 2;
 328                         include_plid = true;
 329                 }
 330                 ie_len += 2;    /* reason code */
 331                 break;
 332         default:
 333                 err = -EINVAL;
 334                 goto free;
 335         }
 336
 337         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 338                 goto free;
 339
 340         pos = skb_put(skb, 2 + ie_len);
 341         *pos++ = WLAN_EID_PEER_MGMT;
 342         *pos++ = ie_len;
 343         memcpy(pos, &peering_proto, 2);
 344         pos += 2;
 345         memcpy(pos, &llid, 2);
 346         pos += 2;
 347         if (include_plid) {
 348                 memcpy(pos, &plid, 2);
 349                 pos += 2;
 350         }
 351         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 352                 memcpy(pos, &reason, 2);
 353                 pos += 2;
 354         }
 355
 356         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 357                 if (mesh_add_ht_cap_ie(sdata, skb) ||
 358                     mesh_add_ht_oper_ie(sdata, skb))
 359                         goto free;
 360         }
 361
 362         if (mesh_add_vendor_ies(sdata, skb))
 363                 goto free;
 364
 365         ieee80211_tx_skb(sdata, skb);
 366         return 0;
 367 free:
 368         kfree_skb(skb);
 369         return err;
 370 }
 371
 372 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 373                                struct sta_info *sta,
 374                                struct ieee802_11_elems *elems, bool insert)
 375 {
 376         struct ieee80211_local *local = sdata->local;
 377         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 378         struct ieee80211_supported_band *sband;
 379         u32 rates, basic_rates = 0, changed = 0;
 380
 381         sband = local->hw.wiphy->bands[band];
 382         rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
 383
 384         spin_lock_bh(&sta->lock);
 385         sta->last_rx = jiffies;
 386
 387         /* rates and capabilities don't change during peering */
 388         if (sta->plink_state == NL80211_PLINK_ESTAB)
 389                 goto out;
 390
 391         if (sta->sta.supp_rates[band] != rates)
 392                 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 393         sta->sta.supp_rates[band] = rates;
 394
 395         if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 396                                               elems->ht_cap_elem, sta))
 397                 changed |= IEEE80211_RC_BW_CHANGED;
 398
 399         /* HT peer is operating 20MHz-only */
 400         if (elems->ht_operation &&
 401             !(elems->ht_operation->ht_param &
 402               IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 403                 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 404                         changed |= IEEE80211_RC_BW_CHANGED;
 405                 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 406         }
 407
 408         if (insert)
 409                 rate_control_rate_init(sta);
 410         else
 411                 rate_control_rate_update(local, sband, sta, changed);
 412 out:
 413         spin_unlock_bh(&sta->lock);
 414 }
 415
 416 static struct sta_info *
 417 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 418 {
 419         struct sta_info *sta;
 420
 421         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 422                 return NULL;
 423
 424         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 425         if (!sta)
 426                 return NULL;
 427
 428         sta->plink_state = NL80211_PLINK_LISTEN;
 429
 430         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 431         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 432         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 433
 434         set_sta_flag(sta, WLAN_STA_WME);
 435
 436         return sta;
 437 }
 438
 439 static struct sta_info *
 440 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 441                     struct ieee802_11_elems *elems)
 442 {
 443         struct sta_info *sta = NULL;
 444
 445         /* Userspace handles station allocation */
 446         if (sdata->u.mesh.user_mpm ||
 447             sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 448                 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 449                                                    elems->ie_start,
 450                                                    elems->total_len,
 451                                                    GFP_KERNEL);
 452         else
 453                 sta = __mesh_sta_info_alloc(sdata, addr);
 454
 455         return sta;
 456 }
 457
 458 /*
 459  * mesh_sta_info_get - return mesh sta info entry for @addr.
 460  *
 461  * @sdata: local meshif
 462  * @addr: peer's address
 463  * @elems: IEs from beacon or mesh peering frame.
 464  *
 465  * Return existing or newly allocated sta_info under RCU read lock.
 466  * (re)initialize with given IEs.
 467  */
 468 static struct sta_info *
 469 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 470                   u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 471 {
 472         struct sta_info *sta = NULL;
 473
 474         rcu_read_lock();
 475         sta = sta_info_get(sdata, addr);
 476         if (sta) {
 477                 mesh_sta_info_init(sdata, sta, elems, false);
 478         } else {
 479                 rcu_read_unlock();
 480                 /* can't run atomic */
 481                 sta = mesh_sta_info_alloc(sdata, addr, elems);
 482                 if (!sta) {
 483                         rcu_read_lock();
 484                         return NULL;
 485                 }
 486
 487                 mesh_sta_info_init(sdata, sta, elems, true);
 488
 489                 if (sta_info_insert_rcu(sta))
 490                         return NULL;
 491         }
 492
 493         return sta;
 494 }
 495
 496 /*
 497  * mesh_neighbour_update - update or initialize new mesh neighbor.
 498  *
 499  * @sdata: local meshif
 500  * @addr: peer's address
 501  * @elems: IEs from beacon or mesh peering frame
 502  *
 503  * Initiates peering if appropriate.
 504  */
 505 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 506                            u8 *hw_addr,
 507                            struct ieee802_11_elems *elems)
 508 {
 509         struct sta_info *sta;
 510         u32 changed = 0;
 511
 512         sta = mesh_sta_info_get(sdata, hw_addr, elems);
 513         if (!sta)
 514                 goto out;
 515
 516         if (mesh_peer_accepts_plinks(elems) &&
 517             sta->plink_state == NL80211_PLINK_LISTEN &&
 518             sdata->u.mesh.accepting_plinks &&
 519             sdata->u.mesh.mshcfg.auto_open_plinks &&
 520             rssi_threshold_check(sta, sdata))
 521                 changed = mesh_plink_open(sta);
 522
 523         ieee80211_mps_frame_release(sta, elems);
 524 out:
 525         rcu_read_unlock();
 526         ieee80211_mbss_info_change_notify(sdata, changed);
 527 }
 528
 529 static void mesh_plink_timer(unsigned long data)
 530 {
 531         struct sta_info *sta;
 532         __le16 llid, plid, reason;
 533         struct ieee80211_sub_if_data *sdata;
 534         struct mesh_config *mshcfg;
 535
 536         /*
 537          * This STA is valid because sta_info_destroy() will
 538          * del_timer_sync() this timer after having made sure
 539          * it cannot be readded (by deleting the plink.)
 540          */
 541         sta = (struct sta_info *) data;
 542
 543         if (sta->sdata->local->quiescing)
 544                 return;
 545
 546         spin_lock_bh(&sta->lock);
 547         if (sta->ignore_plink_timer) {
 548                 sta->ignore_plink_timer = false;
 549                 spin_unlock_bh(&sta->lock);
 550                 return;
 551         }
 552         mpl_dbg(sta->sdata,
 553                 "Mesh plink timer for %pM fired on state %s\n",
 554                 sta->sta.addr, mplstates[sta->plink_state]);
 555         reason = 0;
 556         llid = sta->llid;
 557         plid = sta->plid;
 558         sdata = sta->sdata;
 559         mshcfg = &sdata->u.mesh.mshcfg;
 560
 561         switch (sta->plink_state) {
 562         case NL80211_PLINK_OPN_RCVD:
 563         case NL80211_PLINK_OPN_SNT:
 564                 /* retry timer */
 565                 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) {
 566                         u32 rand;
 567                         mpl_dbg(sta->sdata,
 568                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 569                                 sta->sta.addr, sta->plink_retries,
 570                                 sta->plink_timeout);
 571                         get_random_bytes(&rand, sizeof(u32));
 572                         sta->plink_timeout = sta->plink_timeout +
 573                                              rand % sta->plink_timeout;
 574                         ++sta->plink_retries;
 575                         mod_plink_timer(sta, sta->plink_timeout);
 576                         spin_unlock_bh(&sta->lock);
 577                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 578                                             sta->sta.addr, llid, 0, 0);
 579                         break;
 580                 }
 581                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 582                 /* fall through on else */
 583         case NL80211_PLINK_CNF_RCVD:
 584                 /* confirm timer */
 585                 if (!reason)
 586                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 587                 sta->plink_state = NL80211_PLINK_HOLDING;
 588                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 589                 spin_unlock_bh(&sta->lock);
 590                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 591                                     sta->sta.addr, llid, plid, reason);
 592                 break;
 593         case NL80211_PLINK_HOLDING:
 594                 /* holding timer */
 595                 del_timer(&sta->plink_timer);
 596                 mesh_plink_fsm_restart(sta);
 597                 spin_unlock_bh(&sta->lock);
 598                 break;
 599         default:
 600                 spin_unlock_bh(&sta->lock);
 601                 break;
 602         }
 603 }
 604
 605 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 606 {
 607         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 608         sta->plink_timer.data = (unsigned long) sta;
 609         sta->plink_timer.function = mesh_plink_timer;
 610         sta->plink_timeout = timeout;
 611         add_timer(&sta->plink_timer);
 612 }
 613
 614 u32 mesh_plink_open(struct sta_info *sta)
 615 {
 616         __le16 llid;
 617         struct ieee80211_sub_if_data *sdata = sta->sdata;
 618         u32 changed;
 619
 620         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 621                 return 0;
 622
 623         spin_lock_bh(&sta->lock);
 624         get_random_bytes(&llid, 2);
 625         sta->llid = llid;
 626         if (sta->plink_state != NL80211_PLINK_LISTEN &&
 627             sta->plink_state != NL80211_PLINK_BLOCKED) {
 628                 spin_unlock_bh(&sta->lock);
 629                 return 0;
 630         }
 631         sta->plink_state = NL80211_PLINK_OPN_SNT;
 632         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 633         spin_unlock_bh(&sta->lock);
 634         mpl_dbg(sdata,
 635                 "Mesh plink: starting establishment with %pM\n",
 636                 sta->sta.addr);
 637
 638         /* set the non-peer mode to active during peering */
 639         changed = ieee80211_mps_local_status_update(sdata);
 640
 641         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 642                             sta->sta.addr, llid, 0, 0);
 643         return changed;
 644 }
 645
 646 u32 mesh_plink_block(struct sta_info *sta)
 647 {
 648         u32 changed;
 649
 650         spin_lock_bh(&sta->lock);
 651         changed = __mesh_plink_deactivate(sta);
 652         sta->plink_state = NL80211_PLINK_BLOCKED;
 653         spin_unlock_bh(&sta->lock);
 654
 655         return changed;
 656 }
 657
 658
 659 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 660                          struct ieee80211_mgmt *mgmt, size_t len,
 661                          struct ieee80211_rx_status *rx_status)
 662 {
 663         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 664         struct ieee802_11_elems elems;
 665         struct sta_info *sta;
 666         enum plink_event event;
 667         enum ieee80211_self_protected_actioncode ftype;
 668         size_t baselen;
 669         bool matches_local = true;
 670         u8 ie_len;
 671         u8 *baseaddr;
 672         u32 changed = 0;
 673         __le16 plid, llid, reason;
 674
 675         /* need action_code, aux */
 676         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 677                 return;
 678
 679         if (sdata->u.mesh.user_mpm)
 680                 /* userspace must register for these */
 681                 return;
 682
 683         if (is_multicast_ether_addr(mgmt->da)) {
 684                 mpl_dbg(sdata,
 685                         "Mesh plink: ignore frame from multicast address\n");
 686                 return;
 687         }
 688
 689         baseaddr = mgmt->u.action.u.self_prot.variable;
 690         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 691         if (mgmt->u.action.u.self_prot.action_code ==
 692                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 693                 baseaddr += 4;
 694                 baselen += 4;
 695         }
 696         ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
 697
 698         if (!elems.peering) {
 699                 mpl_dbg(sdata,
 700                         "Mesh plink: missing necessary peer link ie\n");
 701                 return;
 702         }
 703
 704         if (elems.rsn_len &&
 705             sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 706                 mpl_dbg(sdata,
 707                         "Mesh plink: can't establish link with secure peer\n");
 708                 return;
 709         }
 710
 711         ftype = mgmt->u.action.u.self_prot.action_code;
 712         ie_len = elems.peering_len;
 713         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 714             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 715             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 716                                                         && ie_len != 8)) {
 717                 mpl_dbg(sdata,
 718                         "Mesh plink: incorrect plink ie length %d %d\n",
 719                         ftype, ie_len);
 720                 return;
 721         }
 722
 723         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 724             (!elems.mesh_id || !elems.mesh_config)) {
 725                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
 726                 return;
 727         }
 728         /* Note the lines below are correct, the llid in the frame is the plid
 729          * from the point of view of this host.
 730          */
 731         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 732         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 733             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 734                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 735
 736         /* WARNING: Only for sta pointer, is dropped & re-acquired */
 737         rcu_read_lock();
 738
 739         sta = sta_info_get(sdata, mgmt->sa);
 740         if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 741                 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 742                 rcu_read_unlock();
 743                 return;
 744         }
 745
 746         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 747             !rssi_threshold_check(sta, sdata)) {
 748                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
 749                         mgmt->sa);
 750                 rcu_read_unlock();
 751                 return;
 752         }
 753
 754         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 755                 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
 756                 rcu_read_unlock();
 757                 return;
 758         }
 759
 760         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 761                 rcu_read_unlock();
 762                 return;
 763         }
 764
 765         /* Now we will figure out the appropriate event... */
 766         event = PLINK_UNDEFINED;
 767         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 768             !mesh_matches_local(sdata, &elems)) {
 769                 matches_local = false;
 770                 switch (ftype) {
 771                 case WLAN_SP_MESH_PEERING_OPEN:
 772                         event = OPN_RJCT;
 773                         break;
 774                 case WLAN_SP_MESH_PEERING_CONFIRM:
 775                         event = CNF_RJCT;
 776                         break;
 777                 default:
 778                         break;
 779                 }
 780         }
 781
 782         if (!sta && !matches_local) {
 783                 rcu_read_unlock();
 784                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 785                 llid = 0;
 786                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 787                                     mgmt->sa, llid, plid, reason);
 788                 return;
 789         } else if (!sta) {
 790                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 791                 if (!mesh_plink_free_count(sdata)) {
 792                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 793                         rcu_read_unlock();
 794                         return;
 795                 }
 796                 event = OPN_ACPT;
 797         } else if (matches_local) {
 798                 switch (ftype) {
 799                 case WLAN_SP_MESH_PEERING_OPEN:
 800                         if (!mesh_plink_free_count(sdata) ||
 801                             (sta->plid && sta->plid != plid))
 802                                 event = OPN_IGNR;
 803                         else
 804                                 event = OPN_ACPT;
 805                         break;
 806                 case WLAN_SP_MESH_PEERING_CONFIRM:
 807                         if (!mesh_plink_free_count(sdata) ||
 808                             (sta->llid != llid || sta->plid != plid))
 809                                 event = CNF_IGNR;
 810                         else
 811                                 event = CNF_ACPT;
 812                         break;
 813                 case WLAN_SP_MESH_PEERING_CLOSE:
 814                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 815                                 /* Do not check for llid or plid. This does not
 816                                  * follow the standard but since multiple plinks
 817                                  * per sta are not supported, it is necessary in
 818                                  * order to avoid a livelock when MP A sees an
 819                                  * establish peer link to MP B but MP B does not
 820                                  * see it. This can be caused by a timeout in
 821                                  * B's peer link establishment or B beign
 822                                  * restarted.
 823                                  */
 824                                 event = CLS_ACPT;
 825                         else if (sta->plid != plid)
 826                                 event = CLS_IGNR;
 827                         else if (ie_len == 7 && sta->llid != llid)
 828                                 event = CLS_IGNR;
 829                         else
 830                                 event = CLS_ACPT;
 831                         break;
 832                 default:
 833                         mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
 834                         rcu_read_unlock();
 835                         return;
 836                 }
 837         }
 838
 839         if (event == OPN_ACPT) {
 840                 rcu_read_unlock();
 841                 /* allocate sta entry if necessary and update info */
 842                 sta = mesh_sta_info_get(sdata, mgmt->sa, &elems);
 843                 if (!sta) {
 844                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
 845                         rcu_read_unlock();
 846                         return;
 847                 }
 848         }
 849
 850         mpl_dbg(sdata, "peer %pM in state %s got event %s\n", mgmt->sa,
 851                        mplstates[sta->plink_state], mplevents[event]);
 852         reason = 0;
 853         spin_lock_bh(&sta->lock);
 854         switch (sta->plink_state) {
 855                 /* spin_unlock as soon as state is updated at each case */
 856         case NL80211_PLINK_LISTEN:
 857                 switch (event) {
 858                 case CLS_ACPT:
 859                         mesh_plink_fsm_restart(sta);
 860                         spin_unlock_bh(&sta->lock);
 861                         break;
 862                 case OPN_ACPT:
 863                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 864                         sta->plid = plid;
 865                         get_random_bytes(&llid, 2);
 866                         sta->llid = llid;
 867                         mesh_plink_timer_set(sta,
 868                                              mshcfg->dot11MeshRetryTimeout);
 869
 870                         /* set the non-peer mode to active during peering */
 871                         changed |= ieee80211_mps_local_status_update(sdata);
 872
 873                         spin_unlock_bh(&sta->lock);
 874                         mesh_plink_frame_tx(sdata,
 875                                             WLAN_SP_MESH_PEERING_OPEN,
 876                                             sta->sta.addr, llid, 0, 0);
 877                         mesh_plink_frame_tx(sdata,
 878                                             WLAN_SP_MESH_PEERING_CONFIRM,
 879                                             sta->sta.addr, llid, plid, 0);
 880                         break;
 881                 default:
 882                         spin_unlock_bh(&sta->lock);
 883                         break;
 884                 }
 885                 break;
 886
 887         case NL80211_PLINK_OPN_SNT:
 888                 switch (event) {
 889                 case OPN_RJCT:
 890                 case CNF_RJCT:
 891                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 892                 case CLS_ACPT:
 893                         if (!reason)
 894                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 895                         sta->reason = reason;
 896                         sta->plink_state = NL80211_PLINK_HOLDING;
 897                         if (!mod_plink_timer(sta,
 898                                              mshcfg->dot11MeshHoldingTimeout))
 899                                 sta->ignore_plink_timer = true;
 900
 901                         llid = sta->llid;
 902                         spin_unlock_bh(&sta->lock);
 903                         mesh_plink_frame_tx(sdata,
 904                                             WLAN_SP_MESH_PEERING_CLOSE,
 905                                             sta->sta.addr, llid, plid, reason);
 906                         break;
 907                 case OPN_ACPT:
 908                         /* retry timer is left untouched */
 909                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 910                         sta->plid = plid;
 911                         llid = sta->llid;
 912                         spin_unlock_bh(&sta->lock);
 913                         mesh_plink_frame_tx(sdata,
 914                                             WLAN_SP_MESH_PEERING_CONFIRM,
 915                                             sta->sta.addr, llid, plid, 0);
 916                         break;
 917                 case CNF_ACPT:
 918                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 919                         if (!mod_plink_timer(sta,
 920                                              mshcfg->dot11MeshConfirmTimeout))
 921                                 sta->ignore_plink_timer = true;
 922
 923                         spin_unlock_bh(&sta->lock);
 924                         break;
 925                 default:
 926                         spin_unlock_bh(&sta->lock);
 927                         break;
 928                 }
 929                 break;
 930
 931         case NL80211_PLINK_OPN_RCVD:
 932                 switch (event) {
 933                 case OPN_RJCT:
 934                 case CNF_RJCT:
 935                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 936                 case CLS_ACPT:
 937                         if (!reason)
 938                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 939                         sta->reason = reason;
 940                         sta->plink_state = NL80211_PLINK_HOLDING;
 941                         if (!mod_plink_timer(sta,
 942                                              mshcfg->dot11MeshHoldingTimeout))
 943                                 sta->ignore_plink_timer = true;
 944
 945                         llid = sta->llid;
 946                         spin_unlock_bh(&sta->lock);
 947                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 948                                             sta->sta.addr, llid, plid, reason);
 949                         break;
 950                 case OPN_ACPT:
 951                         llid = sta->llid;
 952                         spin_unlock_bh(&sta->lock);
 953                         mesh_plink_frame_tx(sdata,
 954                                             WLAN_SP_MESH_PEERING_CONFIRM,
 955                                             sta->sta.addr, llid, plid, 0);
 956                         break;
 957                 case CNF_ACPT:
 958                         del_timer(&sta->plink_timer);
 959                         sta->plink_state = NL80211_PLINK_ESTAB;
 960                         spin_unlock_bh(&sta->lock);
 961                         changed |= mesh_plink_inc_estab_count(sdata);
 962                         changed |= mesh_set_ht_prot_mode(sdata);
 963                         changed |= mesh_set_short_slot_time(sdata);
 964                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 965                                 sta->sta.addr);
 966                         ieee80211_mps_sta_status_update(sta);
 967                         changed |= ieee80211_mps_set_sta_local_pm(sta,
 968                                                        mshcfg->power_mode);
 969                         break;
 970                 default:
 971                         spin_unlock_bh(&sta->lock);
 972                         break;
 973                 }
 974                 break;
 975
 976         case NL80211_PLINK_CNF_RCVD:
 977                 switch (event) {
 978                 case OPN_RJCT:
 979                 case CNF_RJCT:
 980                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 981                 case CLS_ACPT:
 982                         if (!reason)
 983                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 984                         sta->reason = reason;
 985                         sta->plink_state = NL80211_PLINK_HOLDING;
 986                         if (!mod_plink_timer(sta,
 987                                              mshcfg->dot11MeshHoldingTimeout))
 988                                 sta->ignore_plink_timer = true;
 989
 990                         llid = sta->llid;
 991                         spin_unlock_bh(&sta->lock);
 992                         mesh_plink_frame_tx(sdata,
 993                                             WLAN_SP_MESH_PEERING_CLOSE,
 994                                             sta->sta.addr, llid, plid, reason);
 995                         break;
 996                 case OPN_ACPT:
 997                         del_timer(&sta->plink_timer);
 998                         sta->plink_state = NL80211_PLINK_ESTAB;
 999                         spin_unlock_bh(&sta->lock);
1000                         changed |= mesh_plink_inc_estab_count(sdata);
1001                         changed |= mesh_set_ht_prot_mode(sdata);
1002                         changed |= mesh_set_short_slot_time(sdata);
1003                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
1004                                 sta->sta.addr);
1005                         mesh_plink_frame_tx(sdata,
1006                                             WLAN_SP_MESH_PEERING_CONFIRM,
1007                                             sta->sta.addr, llid, plid, 0);
1008                         ieee80211_mps_sta_status_update(sta);
1009                         changed |= ieee80211_mps_set_sta_local_pm(sta,
1010                                                         mshcfg->power_mode);
1011                         break;
1012                 default:
1013                         spin_unlock_bh(&sta->lock);
1014                         break;
1015                 }
1016                 break;
1017
1018         case NL80211_PLINK_ESTAB:
1019                 switch (event) {
1020                 case CLS_ACPT:
1021                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
1022                         sta->reason = reason;
1023                         changed |= __mesh_plink_deactivate(sta);
1024                         sta->plink_state = NL80211_PLINK_HOLDING;
1025                         llid = sta->llid;
1026                         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
1027                         spin_unlock_bh(&sta->lock);
1028                         changed |= mesh_set_ht_prot_mode(sdata);
1029                         changed |= mesh_set_short_slot_time(sdata);
1030                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1031                                             sta->sta.addr, llid, plid, reason);
1032                         break;
1033                 case OPN_ACPT:
1034                         llid = sta->llid;
1035                         spin_unlock_bh(&sta->lock);
1036                         mesh_plink_frame_tx(sdata,
1037                                             WLAN_SP_MESH_PEERING_CONFIRM,
1038                                             sta->sta.addr, llid, plid, 0);
1039                         break;
1040                 default:
1041                         spin_unlock_bh(&sta->lock);
1042                         break;
1043                 }
1044                 break;
1045         case NL80211_PLINK_HOLDING:
1046                 switch (event) {
1047                 case CLS_ACPT:
1048                         if (del_timer(&sta->plink_timer))
1049                                 sta->ignore_plink_timer = 1;
1050                         mesh_plink_fsm_restart(sta);
1051                         spin_unlock_bh(&sta->lock);
1052                         break;
1053                 case OPN_ACPT:
1054                 case CNF_ACPT:
1055                 case OPN_RJCT:
1056                 case CNF_RJCT:
1057                         llid = sta->llid;
1058                         reason = sta->reason;
1059                         spin_unlock_bh(&sta->lock);
1060                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1061                                             sta->sta.addr, llid, plid, reason);
1062                         break;
1063                 default:
1064                         spin_unlock_bh(&sta->lock);
1065                 }
1066                 break;
1067         default:
1068                 /* should not get here, PLINK_BLOCKED is dealt with at the
1069                  * beginning of the function
1070                  */
1071                 spin_unlock_bh(&sta->lock);
1072                 break;
1073         }
1074
1075         rcu_read_unlock();
1076
1077         if (changed)
1078                 ieee80211_mbss_info_change_notify(sdata, changed);
1079 }