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 int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
  41                 enum ieee80211_self_protected_actioncode action,
  42                 u8 *da, __le16 llid, __le16 plid, __le16 reason);
  43
  44 /**
  45  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  46  *
  47  * @sta: mesh peer link to restart
  48  *
  49  * Locking: this function must be called holding sta->lock
  50  */
  51 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  52 {
  53         sta->plink_state = NL80211_PLINK_LISTEN;
  54         sta->llid = sta->plid = sta->reason = 0;
  55         sta->plink_retries = 0;
  56 }
  57
  58 /*
  59  * mesh_set_short_slot_time - enable / disable ERP short slot time.
  60  *
  61  * The standard indirectly mandates mesh STAs to turn off short slot time by
  62  * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
  63  * can't be sneaky about it. Enable short slot time if all mesh STAs in the
  64  * MBSS support ERP rates.
  65  *
  66  * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
  67  */
  68 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
  69 {
  70         struct ieee80211_local *local = sdata->local;
  71         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
  72         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
  73         struct sta_info *sta;
  74         u32 erp_rates = 0, changed = 0;
  75         int i;
  76         bool short_slot = false;
  77
  78         if (band == IEEE80211_BAND_5GHZ) {
  79                 /* (IEEE 802.11-2012 19.4.5) */
  80                 short_slot = true;
  81                 goto out;
  82         } else if (band != IEEE80211_BAND_2GHZ ||
  83                    (band == IEEE80211_BAND_2GHZ &&
  84                     local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
  85                 goto out;
  86
  87         for (i = 0; i < sband->n_bitrates; i++)
  88                 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
  89                         erp_rates |= BIT(i);
  90
  91         if (!erp_rates)
  92                 goto out;
  93
  94         rcu_read_lock();
  95         list_for_each_entry_rcu(sta, &local->sta_list, list) {
  96                 if (sdata != sta->sdata ||
  97                     sta->plink_state != NL80211_PLINK_ESTAB)
  98                         continue;
  99
 100                 short_slot = false;
 101                 if (erp_rates & sta->sta.supp_rates[band])
 102                         short_slot = true;
 103                  else
 104                         break;
 105         }
 106         rcu_read_unlock();
 107
 108 out:
 109         if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 110                 sdata->vif.bss_conf.use_short_slot = short_slot;
 111                 changed = BSS_CHANGED_ERP_SLOT;
 112                 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 113                         sdata->vif.addr, short_slot);
 114         }
 115         return changed;
 116 }
 117
 118 /**
 119  * mesh_set_ht_prot_mode - set correct HT protection mode
 120  *
 121  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 122  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 123  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 124  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 125  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 126  * HT20 peer is present. Otherwise no-protection mode is selected.
 127  */
 128 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 129 {
 130         struct ieee80211_local *local = sdata->local;
 131         struct sta_info *sta;
 132         u32 changed = 0;
 133         u16 ht_opmode;
 134         bool non_ht_sta = false, ht20_sta = false;
 135
 136         if (sdata->vif.bss_conf.chandef.width == NL80211_CHAN_WIDTH_20_NOHT)
 137                 return 0;
 138
 139         rcu_read_lock();
 140         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 141                 if (sdata != sta->sdata ||
 142                     sta->plink_state != NL80211_PLINK_ESTAB)
 143                         continue;
 144
 145                 switch (sta->ch_width) {
 146                 case NL80211_CHAN_WIDTH_20_NOHT:
 147                         mpl_dbg(sdata,
 148                                 "mesh_plink %pM: nonHT sta (%pM) is present\n",
 149                                 sdata->vif.addr, sta->sta.addr);
 150                         non_ht_sta = true;
 151                         goto out;
 152                 case NL80211_CHAN_WIDTH_20:
 153                         mpl_dbg(sdata,
 154                                 "mesh_plink %pM: HT20 sta (%pM) is present\n",
 155                                 sdata->vif.addr, sta->sta.addr);
 156                         ht20_sta = true;
 157                 default:
 158                         break;
 159                 }
 160         }
 161 out:
 162         rcu_read_unlock();
 163
 164         if (non_ht_sta)
 165                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 166         else if (ht20_sta &&
 167                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 168                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 169         else
 170                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 171
 172         if (sdata->vif.bss_conf.ht_operation_mode != ht_opmode) {
 173                 sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 174                 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 175                 changed = BSS_CHANGED_HT;
 176                 mpl_dbg(sdata,
 177                         "mesh_plink %pM: protection mode changed to %d\n",
 178                         sdata->vif.addr, ht_opmode);
 179         }
 180
 181         return changed;
 182 }
 183
 184 /**
 185  * __mesh_plink_deactivate - deactivate mesh peer link
 186  *
 187  * @sta: mesh peer link to deactivate
 188  *
 189  * All mesh paths with this peer as next hop will be flushed
 190  * Returns beacon changed flag if the beacon content changed.
 191  *
 192  * Locking: the caller must hold sta->lock
 193  */
 194 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 195 {
 196         struct ieee80211_sub_if_data *sdata = sta->sdata;
 197         u32 changed = 0;
 198
 199         if (sta->plink_state == NL80211_PLINK_ESTAB)
 200                 changed = mesh_plink_dec_estab_count(sdata);
 201         sta->plink_state = NL80211_PLINK_BLOCKED;
 202         mesh_path_flush_by_nexthop(sta);
 203
 204         ieee80211_mps_sta_status_update(sta);
 205         ieee80211_mps_local_status_update(sdata);
 206
 207         return changed;
 208 }
 209
 210 /**
 211  * mesh_plink_deactivate - deactivate mesh peer link
 212  *
 213  * @sta: mesh peer link to deactivate
 214  *
 215  * All mesh paths with this peer as next hop will be flushed
 216  */
 217 u32 mesh_plink_deactivate(struct sta_info *sta)
 218 {
 219         struct ieee80211_sub_if_data *sdata = sta->sdata;
 220         u32 changed;
 221
 222         spin_lock_bh(&sta->lock);
 223         changed = __mesh_plink_deactivate(sta);
 224         sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 225         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 226                             sta->sta.addr, sta->llid, sta->plid,
 227                             sta->reason);
 228         spin_unlock_bh(&sta->lock);
 229
 230         return changed;
 231 }
 232
 233 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 234                 enum ieee80211_self_protected_actioncode action,
 235                 u8 *da, __le16 llid, __le16 plid, __le16 reason) {
 236         struct ieee80211_local *local = sdata->local;
 237         struct sk_buff *skb;
 238         struct ieee80211_tx_info *info;
 239         struct ieee80211_mgmt *mgmt;
 240         bool include_plid = false;
 241         u16 peering_proto = 0;
 242         u8 *pos, ie_len = 4;
 243         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 244                       sizeof(mgmt->u.action.u.self_prot);
 245         int err = -ENOMEM;
 246
 247         skb = dev_alloc_skb(local->tx_headroom +
 248                             hdr_len +
 249                             2 + /* capability info */
 250                             2 + /* AID */
 251                             2 + 8 + /* supported rates */
 252                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 253                             2 + sdata->u.mesh.mesh_id_len +
 254                             2 + sizeof(struct ieee80211_meshconf_ie) +
 255                             2 + sizeof(struct ieee80211_ht_cap) +
 256                             2 + sizeof(struct ieee80211_ht_operation) +
 257                             2 + 8 + /* peering IE */
 258                             sdata->u.mesh.ie_len);
 259         if (!skb)
 260                 return -1;
 261         info = IEEE80211_SKB_CB(skb);
 262         skb_reserve(skb, local->tx_headroom);
 263         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 264         memset(mgmt, 0, hdr_len);
 265         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 266                                           IEEE80211_STYPE_ACTION);
 267         memcpy(mgmt->da, da, ETH_ALEN);
 268         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 269         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 270         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 271         mgmt->u.action.u.self_prot.action_code = action;
 272
 273         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 274                 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 275
 276                 /* capability info */
 277                 pos = skb_put(skb, 2);
 278                 memset(pos, 0, 2);
 279                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 280                         /* AID */
 281                         pos = skb_put(skb, 2);
 282                         memcpy(pos + 2, &plid, 2);
 283                 }
 284                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 285                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 286                     mesh_add_rsn_ie(skb, sdata) ||
 287                     mesh_add_meshid_ie(skb, sdata) ||
 288                     mesh_add_meshconf_ie(skb, sdata))
 289                         goto free;
 290         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 291                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 292                 if (mesh_add_meshid_ie(skb, sdata))
 293                         goto free;
 294         }
 295
 296         /* Add Mesh Peering Management element */
 297         switch (action) {
 298         case WLAN_SP_MESH_PEERING_OPEN:
 299                 break;
 300         case WLAN_SP_MESH_PEERING_CONFIRM:
 301                 ie_len += 2;
 302                 include_plid = true;
 303                 break;
 304         case WLAN_SP_MESH_PEERING_CLOSE:
 305                 if (plid) {
 306                         ie_len += 2;
 307                         include_plid = true;
 308                 }
 309                 ie_len += 2;    /* reason code */
 310                 break;
 311         default:
 312                 err = -EINVAL;
 313                 goto free;
 314         }
 315
 316         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 317                 goto free;
 318
 319         pos = skb_put(skb, 2 + ie_len);
 320         *pos++ = WLAN_EID_PEER_MGMT;
 321         *pos++ = ie_len;
 322         memcpy(pos, &peering_proto, 2);
 323         pos += 2;
 324         memcpy(pos, &llid, 2);
 325         pos += 2;
 326         if (include_plid) {
 327                 memcpy(pos, &plid, 2);
 328                 pos += 2;
 329         }
 330         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 331                 memcpy(pos, &reason, 2);
 332                 pos += 2;
 333         }
 334
 335         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 336                 if (mesh_add_ht_cap_ie(skb, sdata) ||
 337                     mesh_add_ht_oper_ie(skb, sdata))
 338                         goto free;
 339         }
 340
 341         if (mesh_add_vendor_ies(skb, sdata))
 342                 goto free;
 343
 344         ieee80211_tx_skb(sdata, skb);
 345         return 0;
 346 free:
 347         kfree_skb(skb);
 348         return err;
 349 }
 350
 351 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 352                                struct sta_info *sta,
 353                                struct ieee802_11_elems *elems, bool insert)
 354 {
 355         struct ieee80211_local *local = sdata->local;
 356         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 357         struct ieee80211_supported_band *sband;
 358         u32 rates, basic_rates = 0, changed = 0;
 359
 360         sband = local->hw.wiphy->bands[band];
 361         rates = ieee80211_sta_get_rates(local, elems, band, &basic_rates);
 362
 363         spin_lock_bh(&sta->lock);
 364         sta->last_rx = jiffies;
 365
 366         /* rates and capabilities don't change during peering */
 367         if (sta->plink_state == NL80211_PLINK_ESTAB)
 368                 goto out;
 369
 370         if (sta->sta.supp_rates[band] != rates)
 371                 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 372         sta->sta.supp_rates[band] = rates;
 373         if (elems->ht_cap_elem &&
 374             sdata->vif.bss_conf.chandef.width != NL80211_CHAN_WIDTH_20_NOHT)
 375                 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 376                                                   elems->ht_cap_elem,
 377                                                   &sta->sta.ht_cap);
 378         else
 379                 memset(&sta->sta.ht_cap, 0, sizeof(sta->sta.ht_cap));
 380
 381         if (elems->ht_operation) {
 382                 struct cfg80211_chan_def chandef;
 383
 384                 if (!(elems->ht_operation->ht_param &
 385                       IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
 386                         sta->sta.ht_cap.cap &=
 387                                             ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 388                 ieee80211_ht_oper_to_chandef(sdata->vif.bss_conf.chandef.chan,
 389                                              elems->ht_operation, &chandef);
 390                 if (sta->ch_width != chandef.width)
 391                         changed |= IEEE80211_RC_BW_CHANGED;
 392                 sta->ch_width = chandef.width;
 393         }
 394
 395         if (insert)
 396                 rate_control_rate_init(sta);
 397         else
 398                 rate_control_rate_update(local, sband, sta, changed);
 399 out:
 400         spin_unlock_bh(&sta->lock);
 401 }
 402
 403 static struct sta_info *
 404 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 405 {
 406         struct sta_info *sta;
 407
 408         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 409                 return NULL;
 410
 411         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 412         if (!sta)
 413                 return NULL;
 414
 415         sta->plink_state = NL80211_PLINK_LISTEN;
 416         init_timer(&sta->plink_timer);
 417
 418         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 419         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 420         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 421
 422         set_sta_flag(sta, WLAN_STA_WME);
 423
 424         return sta;
 425 }
 426
 427 static struct sta_info *
 428 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 429                     struct ieee802_11_elems *elems)
 430 {
 431         struct sta_info *sta = NULL;
 432
 433         /* Userspace handles peer allocation when security is enabled */
 434         if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 435                 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 436                                                    elems->ie_start,
 437                                                    elems->total_len,
 438                                                    GFP_KERNEL);
 439         else
 440                 sta = __mesh_sta_info_alloc(sdata, addr);
 441
 442         return sta;
 443 }
 444
 445 /*
 446  * mesh_sta_info_get - return mesh sta info entry for @addr.
 447  *
 448  * @sdata: local meshif
 449  * @addr: peer's address
 450  * @elems: IEs from beacon or mesh peering frame.
 451  *
 452  * Return existing or newly allocated sta_info under RCU read lock.
 453  * (re)initialize with given IEs.
 454  */
 455 static struct sta_info *
 456 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 457                   u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 458 {
 459         struct sta_info *sta = NULL;
 460
 461         rcu_read_lock();
 462         sta = sta_info_get(sdata, addr);
 463         if (sta) {
 464                 mesh_sta_info_init(sdata, sta, elems, false);
 465         } else {
 466                 rcu_read_unlock();
 467                 /* can't run atomic */
 468                 sta = mesh_sta_info_alloc(sdata, addr, elems);
 469                 if (!sta) {
 470                         rcu_read_lock();
 471                         return NULL;
 472                 }
 473
 474                 mesh_sta_info_init(sdata, sta, elems, true);
 475
 476                 if (sta_info_insert_rcu(sta))
 477                         return NULL;
 478         }
 479
 480         return sta;
 481 }
 482
 483 /*
 484  * mesh_neighbour_update - update or initialize new mesh neighbor.
 485  *
 486  * @sdata: local meshif
 487  * @addr: peer's address
 488  * @elems: IEs from beacon or mesh peering frame
 489  *
 490  * Initiates peering if appropriate.
 491  */
 492 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 493                            u8 *hw_addr,
 494                            struct ieee802_11_elems *elems)
 495 {
 496         struct sta_info *sta;
 497
 498         sta = mesh_sta_info_get(sdata, hw_addr, elems);
 499         if (!sta)
 500                 goto out;
 501
 502         if (mesh_peer_accepts_plinks(elems) &&
 503             sta->plink_state == NL80211_PLINK_LISTEN &&
 504             sdata->u.mesh.accepting_plinks &&
 505             sdata->u.mesh.mshcfg.auto_open_plinks &&
 506             rssi_threshold_check(sta, sdata))
 507                 mesh_plink_open(sta);
 508
 509         ieee80211_mps_frame_release(sta, elems);
 510 out:
 511         rcu_read_unlock();
 512 }
 513
 514 static void mesh_plink_timer(unsigned long data)
 515 {
 516         struct sta_info *sta;
 517         __le16 llid, plid, reason;
 518         struct ieee80211_sub_if_data *sdata;
 519         struct mesh_config *mshcfg;
 520
 521         /*
 522          * This STA is valid because sta_info_destroy() will
 523          * del_timer_sync() this timer after having made sure
 524          * it cannot be readded (by deleting the plink.)
 525          */
 526         sta = (struct sta_info *) data;
 527
 528         if (sta->sdata->local->quiescing) {
 529                 sta->plink_timer_was_running = true;
 530                 return;
 531         }
 532
 533         spin_lock_bh(&sta->lock);
 534         if (sta->ignore_plink_timer) {
 535                 sta->ignore_plink_timer = false;
 536                 spin_unlock_bh(&sta->lock);
 537                 return;
 538         }
 539         mpl_dbg(sta->sdata,
 540                 "Mesh plink timer for %pM fired on state %d\n",
 541                 sta->sta.addr, sta->plink_state);
 542         reason = 0;
 543         llid = sta->llid;
 544         plid = sta->plid;
 545         sdata = sta->sdata;
 546         mshcfg = &sdata->u.mesh.mshcfg;
 547
 548         switch (sta->plink_state) {
 549         case NL80211_PLINK_OPN_RCVD:
 550         case NL80211_PLINK_OPN_SNT:
 551                 /* retry timer */
 552                 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) {
 553                         u32 rand;
 554                         mpl_dbg(sta->sdata,
 555                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 556                                 sta->sta.addr, sta->plink_retries,
 557                                 sta->plink_timeout);
 558                         get_random_bytes(&rand, sizeof(u32));
 559                         sta->plink_timeout = sta->plink_timeout +
 560                                              rand % sta->plink_timeout;
 561                         ++sta->plink_retries;
 562                         mod_plink_timer(sta, sta->plink_timeout);
 563                         spin_unlock_bh(&sta->lock);
 564                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 565                                             sta->sta.addr, llid, 0, 0);
 566                         break;
 567                 }
 568                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 569                 /* fall through on else */
 570         case NL80211_PLINK_CNF_RCVD:
 571                 /* confirm timer */
 572                 if (!reason)
 573                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 574                 sta->plink_state = NL80211_PLINK_HOLDING;
 575                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 576                 spin_unlock_bh(&sta->lock);
 577                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 578                                     sta->sta.addr, llid, plid, reason);
 579                 break;
 580         case NL80211_PLINK_HOLDING:
 581                 /* holding timer */
 582                 del_timer(&sta->plink_timer);
 583                 mesh_plink_fsm_restart(sta);
 584                 spin_unlock_bh(&sta->lock);
 585                 break;
 586         default:
 587                 spin_unlock_bh(&sta->lock);
 588                 break;
 589         }
 590 }
 591
 592 #ifdef CONFIG_PM
 593 void mesh_plink_quiesce(struct sta_info *sta)
 594 {
 595         if (!ieee80211_vif_is_mesh(&sta->sdata->vif))
 596                 return;
 597
 598         /* no kernel mesh sta timers have been initialized */
 599         if (sta->sdata->u.mesh.security != IEEE80211_MESH_SEC_NONE)
 600                 return;
 601
 602         if (del_timer_sync(&sta->plink_timer))
 603                 sta->plink_timer_was_running = true;
 604 }
 605
 606 void mesh_plink_restart(struct sta_info *sta)
 607 {
 608         if (sta->plink_timer_was_running) {
 609                 add_timer(&sta->plink_timer);
 610                 sta->plink_timer_was_running = false;
 611         }
 612 }
 613 #endif
 614
 615 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 616 {
 617         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 618         sta->plink_timer.data = (unsigned long) sta;
 619         sta->plink_timer.function = mesh_plink_timer;
 620         sta->plink_timeout = timeout;
 621         add_timer(&sta->plink_timer);
 622 }
 623
 624 int mesh_plink_open(struct sta_info *sta)
 625 {
 626         __le16 llid;
 627         struct ieee80211_sub_if_data *sdata = sta->sdata;
 628
 629         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 630                 return -EPERM;
 631
 632         spin_lock_bh(&sta->lock);
 633         get_random_bytes(&llid, 2);
 634         sta->llid = llid;
 635         if (sta->plink_state != NL80211_PLINK_LISTEN &&
 636             sta->plink_state != NL80211_PLINK_BLOCKED) {
 637                 spin_unlock_bh(&sta->lock);
 638                 return -EBUSY;
 639         }
 640         sta->plink_state = NL80211_PLINK_OPN_SNT;
 641         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 642         spin_unlock_bh(&sta->lock);
 643         mpl_dbg(sdata,
 644                 "Mesh plink: starting establishment with %pM\n",
 645                 sta->sta.addr);
 646
 647         /* set the non-peer mode to active during peering */
 648         ieee80211_mps_local_status_update(sdata);
 649
 650         return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 651                                    sta->sta.addr, llid, 0, 0);
 652 }
 653
 654 void mesh_plink_block(struct sta_info *sta)
 655 {
 656         struct ieee80211_sub_if_data *sdata = sta->sdata;
 657         u32 changed;
 658
 659         spin_lock_bh(&sta->lock);
 660         changed = __mesh_plink_deactivate(sta);
 661         sta->plink_state = NL80211_PLINK_BLOCKED;
 662         spin_unlock_bh(&sta->lock);
 663
 664         ieee80211_bss_info_change_notify(sdata, changed);
 665 }
 666
 667
 668 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 669                          size_t len, struct ieee80211_rx_status *rx_status)
 670 {
 671         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 672         struct ieee802_11_elems elems;
 673         struct sta_info *sta;
 674         enum plink_event event;
 675         enum ieee80211_self_protected_actioncode ftype;
 676         size_t baselen;
 677         bool matches_local = true;
 678         u8 ie_len;
 679         u8 *baseaddr;
 680         u32 changed = 0;
 681         __le16 plid, llid, reason;
 682         static const char *mplstates[] = {
 683                 [NL80211_PLINK_LISTEN] = "LISTEN",
 684                 [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 685                 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 686                 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 687                 [NL80211_PLINK_ESTAB] = "ESTAB",
 688                 [NL80211_PLINK_HOLDING] = "HOLDING",
 689                 [NL80211_PLINK_BLOCKED] = "BLOCKED"
 690         };
 691
 692         /* need action_code, aux */
 693         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 694                 return;
 695
 696         if (is_multicast_ether_addr(mgmt->da)) {
 697                 mpl_dbg(sdata,
 698                         "Mesh plink: ignore frame from multicast address\n");
 699                 return;
 700         }
 701
 702         baseaddr = mgmt->u.action.u.self_prot.variable;
 703         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 704         if (mgmt->u.action.u.self_prot.action_code ==
 705                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 706                 baseaddr += 4;
 707                 baselen += 4;
 708         }
 709         ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 710         if (!elems.peering) {
 711                 mpl_dbg(sdata,
 712                         "Mesh plink: missing necessary peer link ie\n");
 713                 return;
 714         }
 715         if (elems.rsn_len &&
 716                         sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 717                 mpl_dbg(sdata,
 718                         "Mesh plink: can't establish link with secure peer\n");
 719                 return;
 720         }
 721
 722         ftype = mgmt->u.action.u.self_prot.action_code;
 723         ie_len = elems.peering_len;
 724         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 725             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 726             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 727                                                         && ie_len != 8)) {
 728                 mpl_dbg(sdata,
 729                         "Mesh plink: incorrect plink ie length %d %d\n",
 730                         ftype, ie_len);
 731                 return;
 732         }
 733
 734         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 735                                 (!elems.mesh_id || !elems.mesh_config)) {
 736                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
 737                 return;
 738         }
 739         /* Note the lines below are correct, the llid in the frame is the plid
 740          * from the point of view of this host.
 741          */
 742         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 743         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 744             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 745                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 746
 747         /* WARNING: Only for sta pointer, is dropped & re-acquired */
 748         rcu_read_lock();
 749
 750         sta = sta_info_get(sdata, mgmt->sa);
 751         if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 752                 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 753                 rcu_read_unlock();
 754                 return;
 755         }
 756
 757         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 758             !rssi_threshold_check(sta, sdata)) {
 759                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
 760                         mgmt->sa);
 761                 rcu_read_unlock();
 762                 return;
 763         }
 764
 765         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 766                 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
 767                 rcu_read_unlock();
 768                 return;
 769         }
 770
 771         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 772                 rcu_read_unlock();
 773                 return;
 774         }
 775
 776         /* Now we will figure out the appropriate event... */
 777         event = PLINK_UNDEFINED;
 778         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 779             !mesh_matches_local(sdata, &elems)) {
 780                 matches_local = false;
 781                 switch (ftype) {
 782                 case WLAN_SP_MESH_PEERING_OPEN:
 783                         event = OPN_RJCT;
 784                         break;
 785                 case WLAN_SP_MESH_PEERING_CONFIRM:
 786                         event = CNF_RJCT;
 787                         break;
 788                 default:
 789                         break;
 790                 }
 791         }
 792
 793         if (!sta && !matches_local) {
 794                 rcu_read_unlock();
 795                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 796                 llid = 0;
 797                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 798                                     mgmt->sa, llid, plid, reason);
 799                 return;
 800         } else if (!sta) {
 801                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 802                 if (!mesh_plink_free_count(sdata)) {
 803                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 804                         rcu_read_unlock();
 805                         return;
 806                 }
 807                 event = OPN_ACPT;
 808         } else if (matches_local) {
 809                 switch (ftype) {
 810                 case WLAN_SP_MESH_PEERING_OPEN:
 811                         if (!mesh_plink_free_count(sdata) ||
 812                             (sta->plid && sta->plid != plid))
 813                                 event = OPN_IGNR;
 814                         else
 815                                 event = OPN_ACPT;
 816                         break;
 817                 case WLAN_SP_MESH_PEERING_CONFIRM:
 818                         if (!mesh_plink_free_count(sdata) ||
 819                             (sta->llid != llid || sta->plid != plid))
 820                                 event = CNF_IGNR;
 821                         else
 822                                 event = CNF_ACPT;
 823                         break;
 824                 case WLAN_SP_MESH_PEERING_CLOSE:
 825                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 826                                 /* Do not check for llid or plid. This does not
 827                                  * follow the standard but since multiple plinks
 828                                  * per sta are not supported, it is necessary in
 829                                  * order to avoid a livelock when MP A sees an
 830                                  * establish peer link to MP B but MP B does not
 831                                  * see it. This can be caused by a timeout in
 832                                  * B's peer link establishment or B beign
 833                                  * restarted.
 834                                  */
 835                                 event = CLS_ACPT;
 836                         else if (sta->plid != plid)
 837                                 event = CLS_IGNR;
 838                         else if (ie_len == 7 && sta->llid != llid)
 839                                 event = CLS_IGNR;
 840                         else
 841                                 event = CLS_ACPT;
 842                         break;
 843                 default:
 844                         mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
 845                         rcu_read_unlock();
 846                         return;
 847                 }
 848         }
 849
 850         if (event == OPN_ACPT) {
 851                 rcu_read_unlock();
 852                 /* allocate sta entry if necessary and update info */
 853                 sta = mesh_sta_info_get(sdata, mgmt->sa, &elems);
 854                 if (!sta) {
 855                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
 856                         rcu_read_unlock();
 857                         return;
 858                 }
 859         }
 860
 861         mpl_dbg(sdata,
 862                 "Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 863                 mgmt->sa, mplstates[sta->plink_state],
 864                 le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 865                 event);
 866         reason = 0;
 867         spin_lock_bh(&sta->lock);
 868         switch (sta->plink_state) {
 869                 /* spin_unlock as soon as state is updated at each case */
 870         case NL80211_PLINK_LISTEN:
 871                 switch (event) {
 872                 case CLS_ACPT:
 873                         mesh_plink_fsm_restart(sta);
 874                         spin_unlock_bh(&sta->lock);
 875                         break;
 876                 case OPN_ACPT:
 877                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 878                         sta->plid = plid;
 879                         get_random_bytes(&llid, 2);
 880                         sta->llid = llid;
 881                         mesh_plink_timer_set(sta,
 882                                              mshcfg->dot11MeshRetryTimeout);
 883
 884                         /* set the non-peer mode to active during peering */
 885                         ieee80211_mps_local_status_update(sdata);
 886
 887                         spin_unlock_bh(&sta->lock);
 888                         mesh_plink_frame_tx(sdata,
 889                                             WLAN_SP_MESH_PEERING_OPEN,
 890                                             sta->sta.addr, llid, 0, 0);
 891                         mesh_plink_frame_tx(sdata,
 892                                             WLAN_SP_MESH_PEERING_CONFIRM,
 893                                             sta->sta.addr, llid, plid, 0);
 894                         break;
 895                 default:
 896                         spin_unlock_bh(&sta->lock);
 897                         break;
 898                 }
 899                 break;
 900
 901         case NL80211_PLINK_OPN_SNT:
 902                 switch (event) {
 903                 case OPN_RJCT:
 904                 case CNF_RJCT:
 905                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 906                 case CLS_ACPT:
 907                         if (!reason)
 908                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 909                         sta->reason = reason;
 910                         sta->plink_state = NL80211_PLINK_HOLDING;
 911                         if (!mod_plink_timer(sta,
 912                                              mshcfg->dot11MeshHoldingTimeout))
 913                                 sta->ignore_plink_timer = true;
 914
 915                         llid = sta->llid;
 916                         spin_unlock_bh(&sta->lock);
 917                         mesh_plink_frame_tx(sdata,
 918                                             WLAN_SP_MESH_PEERING_CLOSE,
 919                                             sta->sta.addr, llid, plid, reason);
 920                         break;
 921                 case OPN_ACPT:
 922                         /* retry timer is left untouched */
 923                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 924                         sta->plid = plid;
 925                         llid = sta->llid;
 926                         spin_unlock_bh(&sta->lock);
 927                         mesh_plink_frame_tx(sdata,
 928                                             WLAN_SP_MESH_PEERING_CONFIRM,
 929                                             sta->sta.addr, llid, plid, 0);
 930                         break;
 931                 case CNF_ACPT:
 932                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 933                         if (!mod_plink_timer(sta,
 934                                              mshcfg->dot11MeshConfirmTimeout))
 935                                 sta->ignore_plink_timer = true;
 936
 937                         spin_unlock_bh(&sta->lock);
 938                         break;
 939                 default:
 940                         spin_unlock_bh(&sta->lock);
 941                         break;
 942                 }
 943                 break;
 944
 945         case NL80211_PLINK_OPN_RCVD:
 946                 switch (event) {
 947                 case OPN_RJCT:
 948                 case CNF_RJCT:
 949                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 950                 case CLS_ACPT:
 951                         if (!reason)
 952                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 953                         sta->reason = reason;
 954                         sta->plink_state = NL80211_PLINK_HOLDING;
 955                         if (!mod_plink_timer(sta,
 956                                              mshcfg->dot11MeshHoldingTimeout))
 957                                 sta->ignore_plink_timer = true;
 958
 959                         llid = sta->llid;
 960                         spin_unlock_bh(&sta->lock);
 961                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 962                                             sta->sta.addr, llid, plid, reason);
 963                         break;
 964                 case OPN_ACPT:
 965                         llid = sta->llid;
 966                         spin_unlock_bh(&sta->lock);
 967                         mesh_plink_frame_tx(sdata,
 968                                             WLAN_SP_MESH_PEERING_CONFIRM,
 969                                             sta->sta.addr, llid, plid, 0);
 970                         break;
 971                 case CNF_ACPT:
 972                         del_timer(&sta->plink_timer);
 973                         sta->plink_state = NL80211_PLINK_ESTAB;
 974                         spin_unlock_bh(&sta->lock);
 975                         changed |= mesh_plink_inc_estab_count(sdata);
 976                         changed |= mesh_set_ht_prot_mode(sdata);
 977                         changed |= mesh_set_short_slot_time(sdata);
 978                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 979                                 sta->sta.addr);
 980                         ieee80211_mps_sta_status_update(sta);
 981                         ieee80211_mps_set_sta_local_pm(sta,
 982                                                        mshcfg->power_mode);
 983                         break;
 984                 default:
 985                         spin_unlock_bh(&sta->lock);
 986                         break;
 987                 }
 988                 break;
 989
 990         case NL80211_PLINK_CNF_RCVD:
 991                 switch (event) {
 992                 case OPN_RJCT:
 993                 case CNF_RJCT:
 994                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 995                 case CLS_ACPT:
 996                         if (!reason)
 997                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 998                         sta->reason = reason;
 999                         sta->plink_state = NL80211_PLINK_HOLDING;
1000                         if (!mod_plink_timer(sta,
1001                                              mshcfg->dot11MeshHoldingTimeout))
1002                                 sta->ignore_plink_timer = true;
1003
1004                         llid = sta->llid;
1005                         spin_unlock_bh(&sta->lock);
1006                         mesh_plink_frame_tx(sdata,
1007                                             WLAN_SP_MESH_PEERING_CLOSE,
1008                                             sta->sta.addr, llid, plid, reason);
1009                         break;
1010                 case OPN_ACPT:
1011                         del_timer(&sta->plink_timer);
1012                         sta->plink_state = NL80211_PLINK_ESTAB;
1013                         spin_unlock_bh(&sta->lock);
1014                         changed |= mesh_plink_inc_estab_count(sdata);
1015                         changed |= mesh_set_ht_prot_mode(sdata);
1016                         changed |= mesh_set_short_slot_time(sdata);
1017                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
1018                                 sta->sta.addr);
1019                         mesh_plink_frame_tx(sdata,
1020                                             WLAN_SP_MESH_PEERING_CONFIRM,
1021                                             sta->sta.addr, llid, plid, 0);
1022                         ieee80211_mps_sta_status_update(sta);
1023                         ieee80211_mps_set_sta_local_pm(sta,
1024                                                        mshcfg->power_mode);
1025                         break;
1026                 default:
1027                         spin_unlock_bh(&sta->lock);
1028                         break;
1029                 }
1030                 break;
1031
1032         case NL80211_PLINK_ESTAB:
1033                 switch (event) {
1034                 case CLS_ACPT:
1035                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
1036                         sta->reason = reason;
1037                         changed |= __mesh_plink_deactivate(sta);
1038                         sta->plink_state = NL80211_PLINK_HOLDING;
1039                         llid = sta->llid;
1040                         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
1041                         spin_unlock_bh(&sta->lock);
1042                         changed |= mesh_set_ht_prot_mode(sdata);
1043                         changed |= mesh_set_short_slot_time(sdata);
1044                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1045                                             sta->sta.addr, llid, plid, reason);
1046                         break;
1047                 case OPN_ACPT:
1048                         llid = sta->llid;
1049                         spin_unlock_bh(&sta->lock);
1050                         mesh_plink_frame_tx(sdata,
1051                                             WLAN_SP_MESH_PEERING_CONFIRM,
1052                                             sta->sta.addr, llid, plid, 0);
1053                         break;
1054                 default:
1055                         spin_unlock_bh(&sta->lock);
1056                         break;
1057                 }
1058                 break;
1059         case NL80211_PLINK_HOLDING:
1060                 switch (event) {
1061                 case CLS_ACPT:
1062                         if (del_timer(&sta->plink_timer))
1063                                 sta->ignore_plink_timer = 1;
1064                         mesh_plink_fsm_restart(sta);
1065                         spin_unlock_bh(&sta->lock);
1066                         break;
1067                 case OPN_ACPT:
1068                 case CNF_ACPT:
1069                 case OPN_RJCT:
1070                 case CNF_RJCT:
1071                         llid = sta->llid;
1072                         reason = sta->reason;
1073                         spin_unlock_bh(&sta->lock);
1074                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1075                                             sta->sta.addr, llid, plid, reason);
1076                         break;
1077                 default:
1078                         spin_unlock_bh(&sta->lock);
1079                 }
1080                 break;
1081         default:
1082                 /* should not get here, PLINK_BLOCKED is dealt with at the
1083                  * beginning of the function
1084                  */
1085                 spin_unlock_bh(&sta->lock);
1086                 break;
1087         }
1088
1089         rcu_read_unlock();
1090
1091         if (changed)
1092                 ieee80211_bss_info_change_notify(sdata, changed);
1093 }