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