net/mac80211/mesh_plink.c

   1 /*
   2  * Copyright (c) 2008, 2009 open80211s Ltd.
   3  * Author:     Luis Carlos Cobo <luisca@cozybit.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9 #include <linux/gfp.h>
  10 #include <linux/kernel.h>
  11 #include <linux/random.h>
  12 #include "ieee80211_i.h"
  13 #include "rate.h"
  14 #include "mesh.h"
  15
  16 #define PLINK_GET_LLID(p) (p + 2)
  17 #define PLINK_GET_PLID(p) (p + 4)
  18
  19 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
  20                                 jiffies + HZ * t / 1000))
  21
  22 /* We only need a valid sta if user configured a minimum rssi_threshold. */
  23 #define rssi_threshold_check(sta, sdata) \
  24                 (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
  25                 (sta && (s8) -ewma_read(&sta->avg_signal) > \
  26                 sdata->u.mesh.mshcfg.rssi_threshold))
  27
  28 enum plink_event {
  29         PLINK_UNDEFINED,
  30         OPN_ACPT,
  31         OPN_RJCT,
  32         OPN_IGNR,
  33         CNF_ACPT,
  34         CNF_RJCT,
  35         CNF_IGNR,
  36         CLS_ACPT,
  37         CLS_IGNR
  38 };
  39
  40 static const char * const mplstates[] = {
  41         [NL80211_PLINK_LISTEN] = "LISTEN",
  42         [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
  43         [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
  44         [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
  45         [NL80211_PLINK_ESTAB] = "ESTAB",
  46         [NL80211_PLINK_HOLDING] = "HOLDING",
  47         [NL80211_PLINK_BLOCKED] = "BLOCKED"
  48 };
  49
  50 static const char * const mplevents[] = {
  51         [PLINK_UNDEFINED] = "NONE",
  52         [OPN_ACPT] = "OPN_ACPT",
  53         [OPN_RJCT] = "OPN_RJCT",
  54         [OPN_IGNR] = "OPN_IGNR",
  55         [CNF_ACPT] = "CNF_ACPT",
  56         [CNF_RJCT] = "CNF_RJCT",
  57         [CNF_IGNR] = "CNF_IGNR",
  58         [CLS_ACPT] = "CLS_ACPT",
  59         [CLS_IGNR] = "CLS_IGNR"
  60 };
  61
  62 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
  63                                enum ieee80211_self_protected_actioncode action,
  64                                u8 *da, __le16 llid, __le16 plid, __le16 reason);
  65
  66 /**
  67  * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  68  *
  69  * @sta: mesh peer link to restart
  70  *
  71  * Locking: this function must be called holding sta->lock
  72  */
  73 static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  74 {
  75         sta->plink_state = NL80211_PLINK_LISTEN;
  76         sta->llid = sta->plid = sta->reason = 0;
  77         sta->plink_retries = 0;
  78 }
  79
  80 /*
  81  * mesh_set_short_slot_time - enable / disable ERP short slot time.
  82  *
  83  * The standard indirectly mandates mesh STAs to turn off short slot time by
  84  * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
  85  * can't be sneaky about it. Enable short slot time if all mesh STAs in the
  86  * MBSS support ERP rates.
  87  *
  88  * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
  89  */
  90 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
  91 {
  92         struct ieee80211_local *local = sdata->local;
  93         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
  94         struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
  95         struct sta_info *sta;
  96         u32 erp_rates = 0, changed = 0;
  97         int i;
  98         bool short_slot = false;
  99
 100         if (band == IEEE80211_BAND_5GHZ) {
 101                 /* (IEEE 802.11-2012 19.4.5) */
 102                 short_slot = true;
 103                 goto out;
 104         } else if (band != IEEE80211_BAND_2GHZ ||
 105                    (band == IEEE80211_BAND_2GHZ &&
 106                     local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
 107                 goto out;
 108
 109         for (i = 0; i < sband->n_bitrates; i++)
 110                 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
 111                         erp_rates |= BIT(i);
 112
 113         if (!erp_rates)
 114                 goto out;
 115
 116         rcu_read_lock();
 117         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 118                 if (sdata != sta->sdata ||
 119                     sta->plink_state != NL80211_PLINK_ESTAB)
 120                         continue;
 121
 122                 short_slot = false;
 123                 if (erp_rates & sta->sta.supp_rates[band])
 124                         short_slot = true;
 125                  else
 126                         break;
 127         }
 128         rcu_read_unlock();
 129
 130 out:
 131         if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 132                 sdata->vif.bss_conf.use_short_slot = short_slot;
 133                 changed = BSS_CHANGED_ERP_SLOT;
 134                 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 135                         sdata->vif.addr, short_slot);
 136         }
 137         return changed;
 138 }
 139
 140 /**
 141  * mesh_set_ht_prot_mode - set correct HT protection mode
 142  *
 143  * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 144  * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 145  * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 146  * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 147  * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 148  * HT20 peer is present. Otherwise no-protection mode is selected.
 149  */
 150 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 151 {
 152         struct ieee80211_local *local = sdata->local;
 153         struct sta_info *sta;
 154         u16 ht_opmode;
 155         bool non_ht_sta = false, ht20_sta = false;
 156
 157         switch (sdata->vif.bss_conf.chandef.width) {
 158         case NL80211_CHAN_WIDTH_20_NOHT:
 159         case NL80211_CHAN_WIDTH_5:
 160         case NL80211_CHAN_WIDTH_10:
 161                 return 0;
 162         default:
 163                 break;
 164         }
 165
 166         rcu_read_lock();
 167         list_for_each_entry_rcu(sta, &local->sta_list, list) {
 168                 if (sdata != sta->sdata ||
 169                     sta->plink_state != NL80211_PLINK_ESTAB)
 170                         continue;
 171
 172                 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
 173                         continue;
 174
 175                 if (!sta->sta.ht_cap.ht_supported) {
 176                         mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
 177                                        sta->sta.addr);
 178                         non_ht_sta = true;
 179                         break;
 180                 }
 181
 182                 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
 183                 ht20_sta = true;
 184         }
 185         rcu_read_unlock();
 186
 187         if (non_ht_sta)
 188                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 189         else if (ht20_sta &&
 190                  sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 191                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 192         else
 193                 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 194
 195         if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
 196                 return 0;
 197
 198         sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 199         sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 200         mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
 201         return BSS_CHANGED_HT;
 202 }
 203
 204 /**
 205  * __mesh_plink_deactivate - deactivate mesh peer link
 206  *
 207  * @sta: mesh peer link to deactivate
 208  *
 209  * All mesh paths with this peer as next hop will be flushed
 210  * Returns beacon changed flag if the beacon content changed.
 211  *
 212  * Locking: the caller must hold sta->lock
 213  */
 214 static u32 __mesh_plink_deactivate(struct sta_info *sta)
 215 {
 216         struct ieee80211_sub_if_data *sdata = sta->sdata;
 217         u32 changed = 0;
 218
 219         if (sta->plink_state == NL80211_PLINK_ESTAB)
 220                 changed = mesh_plink_dec_estab_count(sdata);
 221         sta->plink_state = NL80211_PLINK_BLOCKED;
 222         mesh_path_flush_by_nexthop(sta);
 223
 224         ieee80211_mps_sta_status_update(sta);
 225         changed |= ieee80211_mps_set_sta_local_pm(sta,
 226                         NL80211_MESH_POWER_UNKNOWN);
 227
 228         return changed;
 229 }
 230
 231 /**
 232  * mesh_plink_deactivate - deactivate mesh peer link
 233  *
 234  * @sta: mesh peer link to deactivate
 235  *
 236  * All mesh paths with this peer as next hop will be flushed
 237  */
 238 u32 mesh_plink_deactivate(struct sta_info *sta)
 239 {
 240         struct ieee80211_sub_if_data *sdata = sta->sdata;
 241         u32 changed;
 242
 243         spin_lock_bh(&sta->lock);
 244         changed = __mesh_plink_deactivate(sta);
 245         sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 246         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 247                             sta->sta.addr, sta->llid, sta->plid,
 248                             sta->reason);
 249         spin_unlock_bh(&sta->lock);
 250
 251         return changed;
 252 }
 253
 254 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 255                                enum ieee80211_self_protected_actioncode action,
 256                                u8 *da, __le16 llid, __le16 plid, __le16 reason)
 257 {
 258         struct ieee80211_local *local = sdata->local;
 259         struct sk_buff *skb;
 260         struct ieee80211_tx_info *info;
 261         struct ieee80211_mgmt *mgmt;
 262         bool include_plid = false;
 263         u16 peering_proto = 0;
 264         u8 *pos, ie_len = 4;
 265         int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 266                       sizeof(mgmt->u.action.u.self_prot);
 267         int err = -ENOMEM;
 268
 269         skb = dev_alloc_skb(local->tx_headroom +
 270                             hdr_len +
 271                             2 + /* capability info */
 272                             2 + /* AID */
 273                             2 + 8 + /* supported rates */
 274                             2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 275                             2 + sdata->u.mesh.mesh_id_len +
 276                             2 + sizeof(struct ieee80211_meshconf_ie) +
 277                             2 + sizeof(struct ieee80211_ht_cap) +
 278                             2 + sizeof(struct ieee80211_ht_operation) +
 279                             2 + 8 + /* peering IE */
 280                             sdata->u.mesh.ie_len);
 281         if (!skb)
 282                 return -1;
 283         info = IEEE80211_SKB_CB(skb);
 284         skb_reserve(skb, local->tx_headroom);
 285         mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 286         memset(mgmt, 0, hdr_len);
 287         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 288                                           IEEE80211_STYPE_ACTION);
 289         memcpy(mgmt->da, da, ETH_ALEN);
 290         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 291         memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 292         mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 293         mgmt->u.action.u.self_prot.action_code = action;
 294
 295         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 296                 enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 297
 298                 /* capability info */
 299                 pos = skb_put(skb, 2);
 300                 memset(pos, 0, 2);
 301                 if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 302                         /* AID */
 303                         pos = skb_put(skb, 2);
 304                         memcpy(pos + 2, &plid, 2);
 305                 }
 306                 if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 307                     ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 308                     mesh_add_rsn_ie(sdata, skb) ||
 309                     mesh_add_meshid_ie(sdata, skb) ||
 310                     mesh_add_meshconf_ie(sdata, skb))
 311                         goto free;
 312         } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 313                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 314                 if (mesh_add_meshid_ie(sdata, skb))
 315                         goto free;
 316         }
 317
 318         /* Add Mesh Peering Management element */
 319         switch (action) {
 320         case WLAN_SP_MESH_PEERING_OPEN:
 321                 break;
 322         case WLAN_SP_MESH_PEERING_CONFIRM:
 323                 ie_len += 2;
 324                 include_plid = true;
 325                 break;
 326         case WLAN_SP_MESH_PEERING_CLOSE:
 327                 if (plid) {
 328                         ie_len += 2;
 329                         include_plid = true;
 330                 }
 331                 ie_len += 2;    /* reason code */
 332                 break;
 333         default:
 334                 err = -EINVAL;
 335                 goto free;
 336         }
 337
 338         if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 339                 goto free;
 340
 341         pos = skb_put(skb, 2 + ie_len);
 342         *pos++ = WLAN_EID_PEER_MGMT;
 343         *pos++ = ie_len;
 344         memcpy(pos, &peering_proto, 2);
 345         pos += 2;
 346         memcpy(pos, &llid, 2);
 347         pos += 2;
 348         if (include_plid) {
 349                 memcpy(pos, &plid, 2);
 350                 pos += 2;
 351         }
 352         if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 353                 memcpy(pos, &reason, 2);
 354                 pos += 2;
 355         }
 356
 357         if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 358                 if (mesh_add_ht_cap_ie(sdata, skb) ||
 359                     mesh_add_ht_oper_ie(sdata, skb))
 360                         goto free;
 361         }
 362
 363         if (mesh_add_vendor_ies(sdata, skb))
 364                 goto free;
 365
 366         ieee80211_tx_skb(sdata, skb);
 367         return 0;
 368 free:
 369         kfree_skb(skb);
 370         return err;
 371 }
 372
 373 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 374                                struct sta_info *sta,
 375                                struct ieee802_11_elems *elems, bool insert)
 376 {
 377         struct ieee80211_local *local = sdata->local;
 378         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 379         struct ieee80211_supported_band *sband;
 380         u32 rates, basic_rates = 0, changed = 0;
 381
 382         sband = local->hw.wiphy->bands[band];
 383         rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
 384
 385         spin_lock_bh(&sta->lock);
 386         sta->last_rx = jiffies;
 387
 388         /* rates and capabilities don't change during peering */
 389         if (sta->plink_state == NL80211_PLINK_ESTAB)
 390                 goto out;
 391
 392         if (sta->sta.supp_rates[band] != rates)
 393                 changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 394         sta->sta.supp_rates[band] = rates;
 395
 396         if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 397                                               elems->ht_cap_elem, sta))
 398                 changed |= IEEE80211_RC_BW_CHANGED;
 399
 400         /* HT peer is operating 20MHz-only */
 401         if (elems->ht_operation &&
 402             !(elems->ht_operation->ht_param &
 403               IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 404                 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 405                         changed |= IEEE80211_RC_BW_CHANGED;
 406                 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 407         }
 408
 409         if (insert)
 410                 rate_control_rate_init(sta);
 411         else
 412                 rate_control_rate_update(local, sband, sta, changed);
 413 out:
 414         spin_unlock_bh(&sta->lock);
 415 }
 416
 417 static struct sta_info *
 418 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 419 {
 420         struct sta_info *sta;
 421
 422         if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 423                 return NULL;
 424
 425         sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 426         if (!sta)
 427                 return NULL;
 428
 429         sta->plink_state = NL80211_PLINK_LISTEN;
 430
 431         sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 432         sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 433         sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 434
 435         set_sta_flag(sta, WLAN_STA_WME);
 436
 437         return sta;
 438 }
 439
 440 static struct sta_info *
 441 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 442                     struct ieee802_11_elems *elems)
 443 {
 444         struct sta_info *sta = NULL;
 445
 446         /* Userspace handles station allocation */
 447         if (sdata->u.mesh.user_mpm ||
 448             sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 449                 cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 450                                                    elems->ie_start,
 451                                                    elems->total_len,
 452                                                    GFP_KERNEL);
 453         else
 454                 sta = __mesh_sta_info_alloc(sdata, addr);
 455
 456         return sta;
 457 }
 458
 459 /*
 460  * mesh_sta_info_get - return mesh sta info entry for @addr.
 461  *
 462  * @sdata: local meshif
 463  * @addr: peer's address
 464  * @elems: IEs from beacon or mesh peering frame.
 465  *
 466  * Return existing or newly allocated sta_info under RCU read lock.
 467  * (re)initialize with given IEs.
 468  */
 469 static struct sta_info *
 470 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 471                   u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 472 {
 473         struct sta_info *sta = NULL;
 474
 475         rcu_read_lock();
 476         sta = sta_info_get(sdata, addr);
 477         if (sta) {
 478                 mesh_sta_info_init(sdata, sta, elems, false);
 479         } else {
 480                 rcu_read_unlock();
 481                 /* can't run atomic */
 482                 sta = mesh_sta_info_alloc(sdata, addr, elems);
 483                 if (!sta) {
 484                         rcu_read_lock();
 485                         return NULL;
 486                 }
 487
 488                 mesh_sta_info_init(sdata, sta, elems, true);
 489
 490                 if (sta_info_insert_rcu(sta))
 491                         return NULL;
 492         }
 493
 494         return sta;
 495 }
 496
 497 /*
 498  * mesh_neighbour_update - update or initialize new mesh neighbor.
 499  *
 500  * @sdata: local meshif
 501  * @addr: peer's address
 502  * @elems: IEs from beacon or mesh peering frame
 503  *
 504  * Initiates peering if appropriate.
 505  */
 506 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 507                            u8 *hw_addr,
 508                            struct ieee802_11_elems *elems)
 509 {
 510         struct sta_info *sta;
 511         u32 changed = 0;
 512
 513         sta = mesh_sta_info_get(sdata, hw_addr, elems);
 514         if (!sta)
 515                 goto out;
 516
 517         if (mesh_peer_accepts_plinks(elems) &&
 518             sta->plink_state == NL80211_PLINK_LISTEN &&
 519             sdata->u.mesh.accepting_plinks &&
 520             sdata->u.mesh.mshcfg.auto_open_plinks &&
 521             rssi_threshold_check(sta, sdata))
 522                 changed = mesh_plink_open(sta);
 523
 524         ieee80211_mps_frame_release(sta, elems);
 525 out:
 526         rcu_read_unlock();
 527         ieee80211_mbss_info_change_notify(sdata, changed);
 528 }
 529
 530 static void mesh_plink_timer(unsigned long data)
 531 {
 532         struct sta_info *sta;
 533         __le16 llid, plid, reason;
 534         struct ieee80211_sub_if_data *sdata;
 535         struct mesh_config *mshcfg;
 536
 537         /*
 538          * This STA is valid because sta_info_destroy() will
 539          * del_timer_sync() this timer after having made sure
 540          * it cannot be readded (by deleting the plink.)
 541          */
 542         sta = (struct sta_info *) data;
 543
 544         if (sta->sdata->local->quiescing)
 545                 return;
 546
 547         spin_lock_bh(&sta->lock);
 548         if (sta->ignore_plink_timer) {
 549                 sta->ignore_plink_timer = false;
 550                 spin_unlock_bh(&sta->lock);
 551                 return;
 552         }
 553         mpl_dbg(sta->sdata,
 554                 "Mesh plink timer for %pM fired on state %s\n",
 555                 sta->sta.addr, mplstates[sta->plink_state]);
 556         reason = 0;
 557         llid = sta->llid;
 558         plid = sta->plid;
 559         sdata = sta->sdata;
 560         mshcfg = &sdata->u.mesh.mshcfg;
 561
 562         switch (sta->plink_state) {
 563         case NL80211_PLINK_OPN_RCVD:
 564         case NL80211_PLINK_OPN_SNT:
 565                 /* retry timer */
 566                 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) {
 567                         u32 rand;
 568                         mpl_dbg(sta->sdata,
 569                                 "Mesh plink for %pM (retry, timeout): %d %d\n",
 570                                 sta->sta.addr, sta->plink_retries,
 571                                 sta->plink_timeout);
 572                         get_random_bytes(&rand, sizeof(u32));
 573                         sta->plink_timeout = sta->plink_timeout +
 574                                              rand % sta->plink_timeout;
 575                         ++sta->plink_retries;
 576                         mod_plink_timer(sta, sta->plink_timeout);
 577                         spin_unlock_bh(&sta->lock);
 578                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 579                                             sta->sta.addr, llid, 0, 0);
 580                         break;
 581                 }
 582                 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 583                 /* fall through on else */
 584         case NL80211_PLINK_CNF_RCVD:
 585                 /* confirm timer */
 586                 if (!reason)
 587                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 588                 sta->plink_state = NL80211_PLINK_HOLDING;
 589                 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 590                 spin_unlock_bh(&sta->lock);
 591                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 592                                     sta->sta.addr, llid, plid, reason);
 593                 break;
 594         case NL80211_PLINK_HOLDING:
 595                 /* holding timer */
 596                 del_timer(&sta->plink_timer);
 597                 mesh_plink_fsm_restart(sta);
 598                 spin_unlock_bh(&sta->lock);
 599                 break;
 600         default:
 601                 spin_unlock_bh(&sta->lock);
 602                 break;
 603         }
 604 }
 605
 606 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 607 {
 608         sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 609         sta->plink_timer.data = (unsigned long) sta;
 610         sta->plink_timer.function = mesh_plink_timer;
 611         sta->plink_timeout = timeout;
 612         add_timer(&sta->plink_timer);
 613 }
 614
 615 u32 mesh_plink_open(struct sta_info *sta)
 616 {
 617         __le16 llid;
 618         struct ieee80211_sub_if_data *sdata = sta->sdata;
 619         u32 changed;
 620
 621         if (!test_sta_flag(sta, WLAN_STA_AUTH))
 622                 return 0;
 623
 624         spin_lock_bh(&sta->lock);
 625         get_random_bytes(&llid, 2);
 626         sta->llid = llid;
 627         if (sta->plink_state != NL80211_PLINK_LISTEN &&
 628             sta->plink_state != NL80211_PLINK_BLOCKED) {
 629                 spin_unlock_bh(&sta->lock);
 630                 return 0;
 631         }
 632         sta->plink_state = NL80211_PLINK_OPN_SNT;
 633         mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 634         spin_unlock_bh(&sta->lock);
 635         mpl_dbg(sdata,
 636                 "Mesh plink: starting establishment with %pM\n",
 637                 sta->sta.addr);
 638
 639         /* set the non-peer mode to active during peering */
 640         changed = ieee80211_mps_local_status_update(sdata);
 641
 642         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 643                             sta->sta.addr, llid, 0, 0);
 644         return changed;
 645 }
 646
 647 u32 mesh_plink_block(struct sta_info *sta)
 648 {
 649         u32 changed;
 650
 651         spin_lock_bh(&sta->lock);
 652         changed = __mesh_plink_deactivate(sta);
 653         sta->plink_state = NL80211_PLINK_BLOCKED;
 654         spin_unlock_bh(&sta->lock);
 655
 656         return changed;
 657 }
 658
 659
 660 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 661                          struct ieee80211_mgmt *mgmt, size_t len,
 662                          struct ieee80211_rx_status *rx_status)
 663 {
 664         struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 665         struct ieee802_11_elems elems;
 666         struct sta_info *sta;
 667         enum plink_event event;
 668         enum ieee80211_self_protected_actioncode ftype;
 669         size_t baselen;
 670         bool matches_local = true;
 671         u8 ie_len;
 672         u8 *baseaddr;
 673         u32 changed = 0;
 674         __le16 plid, llid, reason;
 675
 676         /* need action_code, aux */
 677         if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 678                 return;
 679
 680         if (sdata->u.mesh.user_mpm)
 681                 /* userspace must register for these */
 682                 return;
 683
 684         if (is_multicast_ether_addr(mgmt->da)) {
 685                 mpl_dbg(sdata,
 686                         "Mesh plink: ignore frame from multicast address\n");
 687                 return;
 688         }
 689
 690         baseaddr = mgmt->u.action.u.self_prot.variable;
 691         baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 692         if (mgmt->u.action.u.self_prot.action_code ==
 693                                                 WLAN_SP_MESH_PEERING_CONFIRM) {
 694                 baseaddr += 4;
 695                 baselen += 4;
 696         }
 697         ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
 698
 699         if (!elems.peering) {
 700                 mpl_dbg(sdata,
 701                         "Mesh plink: missing necessary peer link ie\n");
 702                 return;
 703         }
 704
 705         if (elems.rsn_len &&
 706             sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 707                 mpl_dbg(sdata,
 708                         "Mesh plink: can't establish link with secure peer\n");
 709                 return;
 710         }
 711
 712         ftype = mgmt->u.action.u.self_prot.action_code;
 713         ie_len = elems.peering_len;
 714         if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 715             (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 716             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 717                                                         && ie_len != 8)) {
 718                 mpl_dbg(sdata,
 719                         "Mesh plink: incorrect plink ie length %d %d\n",
 720                         ftype, ie_len);
 721                 return;
 722         }
 723
 724         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 725             (!elems.mesh_id || !elems.mesh_config)) {
 726                 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
 727                 return;
 728         }
 729         /* Note the lines below are correct, the llid in the frame is the plid
 730          * from the point of view of this host.
 731          */
 732         memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 733         if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 734             (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 735                 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 736
 737         /* WARNING: Only for sta pointer, is dropped & re-acquired */
 738         rcu_read_lock();
 739
 740         sta = sta_info_get(sdata, mgmt->sa);
 741         if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 742                 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 743                 rcu_read_unlock();
 744                 return;
 745         }
 746
 747         if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 748             !rssi_threshold_check(sta, sdata)) {
 749                 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
 750                         mgmt->sa);
 751                 rcu_read_unlock();
 752                 return;
 753         }
 754
 755         if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 756                 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
 757                 rcu_read_unlock();
 758                 return;
 759         }
 760
 761         if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 762                 rcu_read_unlock();
 763                 return;
 764         }
 765
 766         /* Now we will figure out the appropriate event... */
 767         event = PLINK_UNDEFINED;
 768         if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 769             !mesh_matches_local(sdata, &elems)) {
 770                 matches_local = false;
 771                 switch (ftype) {
 772                 case WLAN_SP_MESH_PEERING_OPEN:
 773                         event = OPN_RJCT;
 774                         break;
 775                 case WLAN_SP_MESH_PEERING_CONFIRM:
 776                         event = CNF_RJCT;
 777                         break;
 778                 default:
 779                         break;
 780                 }
 781         }
 782
 783         if (!sta && !matches_local) {
 784                 rcu_read_unlock();
 785                 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 786                 llid = 0;
 787                 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 788                                     mgmt->sa, llid, plid, reason);
 789                 return;
 790         } else if (!sta) {
 791                 /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 792                 if (!mesh_plink_free_count(sdata)) {
 793                         mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 794                         rcu_read_unlock();
 795                         return;
 796                 }
 797                 event = OPN_ACPT;
 798         } else if (matches_local) {
 799                 switch (ftype) {
 800                 case WLAN_SP_MESH_PEERING_OPEN:
 801                         if (!mesh_plink_free_count(sdata) ||
 802                             (sta->plid && sta->plid != plid))
 803                                 event = OPN_IGNR;
 804                         else
 805                                 event = OPN_ACPT;
 806                         break;
 807                 case WLAN_SP_MESH_PEERING_CONFIRM:
 808                         if (!mesh_plink_free_count(sdata) ||
 809                             (sta->llid != llid || sta->plid != plid))
 810                                 event = CNF_IGNR;
 811                         else
 812                                 event = CNF_ACPT;
 813                         break;
 814                 case WLAN_SP_MESH_PEERING_CLOSE:
 815                         if (sta->plink_state == NL80211_PLINK_ESTAB)
 816                                 /* Do not check for llid or plid. This does not
 817                                  * follow the standard but since multiple plinks
 818                                  * per sta are not supported, it is necessary in
 819                                  * order to avoid a livelock when MP A sees an
 820                                  * establish peer link to MP B but MP B does not
 821                                  * see it. This can be caused by a timeout in
 822                                  * B's peer link establishment or B beign
 823                                  * restarted.
 824                                  */
 825                                 event = CLS_ACPT;
 826                         else if (sta->plid != plid)
 827                                 event = CLS_IGNR;
 828                         else if (ie_len == 7 && sta->llid != llid)
 829                                 event = CLS_IGNR;
 830                         else
 831                                 event = CLS_ACPT;
 832                         break;
 833                 default:
 834                         mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
 835                         rcu_read_unlock();
 836                         return;
 837                 }
 838         }
 839
 840         if (event == OPN_ACPT) {
 841                 rcu_read_unlock();
 842                 /* allocate sta entry if necessary and update info */
 843                 sta = mesh_sta_info_get(sdata, mgmt->sa, &elems);
 844                 if (!sta) {
 845                         mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
 846                         rcu_read_unlock();
 847                         return;
 848                 }
 849         }
 850
 851         mpl_dbg(sdata, "peer %pM in state %s got event %s\n", mgmt->sa,
 852                        mplstates[sta->plink_state], mplevents[event]);
 853         reason = 0;
 854         spin_lock_bh(&sta->lock);
 855         switch (sta->plink_state) {
 856                 /* spin_unlock as soon as state is updated at each case */
 857         case NL80211_PLINK_LISTEN:
 858                 switch (event) {
 859                 case CLS_ACPT:
 860                         mesh_plink_fsm_restart(sta);
 861                         spin_unlock_bh(&sta->lock);
 862                         break;
 863                 case OPN_ACPT:
 864                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 865                         sta->plid = plid;
 866                         get_random_bytes(&llid, 2);
 867                         sta->llid = llid;
 868                         mesh_plink_timer_set(sta,
 869                                              mshcfg->dot11MeshRetryTimeout);
 870
 871                         /* set the non-peer mode to active during peering */
 872                         changed |= ieee80211_mps_local_status_update(sdata);
 873
 874                         spin_unlock_bh(&sta->lock);
 875                         mesh_plink_frame_tx(sdata,
 876                                             WLAN_SP_MESH_PEERING_OPEN,
 877                                             sta->sta.addr, llid, 0, 0);
 878                         mesh_plink_frame_tx(sdata,
 879                                             WLAN_SP_MESH_PEERING_CONFIRM,
 880                                             sta->sta.addr, llid, plid, 0);
 881                         break;
 882                 default:
 883                         spin_unlock_bh(&sta->lock);
 884                         break;
 885                 }
 886                 break;
 887
 888         case NL80211_PLINK_OPN_SNT:
 889                 switch (event) {
 890                 case OPN_RJCT:
 891                 case CNF_RJCT:
 892                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 893                 case CLS_ACPT:
 894                         if (!reason)
 895                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 896                         sta->reason = reason;
 897                         sta->plink_state = NL80211_PLINK_HOLDING;
 898                         if (!mod_plink_timer(sta,
 899                                              mshcfg->dot11MeshHoldingTimeout))
 900                                 sta->ignore_plink_timer = true;
 901
 902                         llid = sta->llid;
 903                         spin_unlock_bh(&sta->lock);
 904                         mesh_plink_frame_tx(sdata,
 905                                             WLAN_SP_MESH_PEERING_CLOSE,
 906                                             sta->sta.addr, llid, plid, reason);
 907                         break;
 908                 case OPN_ACPT:
 909                         /* retry timer is left untouched */
 910                         sta->plink_state = NL80211_PLINK_OPN_RCVD;
 911                         sta->plid = plid;
 912                         llid = sta->llid;
 913                         spin_unlock_bh(&sta->lock);
 914                         mesh_plink_frame_tx(sdata,
 915                                             WLAN_SP_MESH_PEERING_CONFIRM,
 916                                             sta->sta.addr, llid, plid, 0);
 917                         break;
 918                 case CNF_ACPT:
 919                         sta->plink_state = NL80211_PLINK_CNF_RCVD;
 920                         if (!mod_plink_timer(sta,
 921                                              mshcfg->dot11MeshConfirmTimeout))
 922                                 sta->ignore_plink_timer = true;
 923
 924                         spin_unlock_bh(&sta->lock);
 925                         break;
 926                 default:
 927                         spin_unlock_bh(&sta->lock);
 928                         break;
 929                 }
 930                 break;
 931
 932         case NL80211_PLINK_OPN_RCVD:
 933                 switch (event) {
 934                 case OPN_RJCT:
 935                 case CNF_RJCT:
 936                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 937                 case CLS_ACPT:
 938                         if (!reason)
 939                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 940                         sta->reason = reason;
 941                         sta->plink_state = NL80211_PLINK_HOLDING;
 942                         if (!mod_plink_timer(sta,
 943                                              mshcfg->dot11MeshHoldingTimeout))
 944                                 sta->ignore_plink_timer = true;
 945
 946                         llid = sta->llid;
 947                         spin_unlock_bh(&sta->lock);
 948                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 949                                             sta->sta.addr, llid, plid, reason);
 950                         break;
 951                 case OPN_ACPT:
 952                         llid = sta->llid;
 953                         spin_unlock_bh(&sta->lock);
 954                         mesh_plink_frame_tx(sdata,
 955                                             WLAN_SP_MESH_PEERING_CONFIRM,
 956                                             sta->sta.addr, llid, plid, 0);
 957                         break;
 958                 case CNF_ACPT:
 959                         del_timer(&sta->plink_timer);
 960                         sta->plink_state = NL80211_PLINK_ESTAB;
 961                         spin_unlock_bh(&sta->lock);
 962                         changed |= mesh_plink_inc_estab_count(sdata);
 963                         changed |= mesh_set_ht_prot_mode(sdata);
 964                         changed |= mesh_set_short_slot_time(sdata);
 965                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 966                                 sta->sta.addr);
 967                         ieee80211_mps_sta_status_update(sta);
 968                         changed |= ieee80211_mps_set_sta_local_pm(sta,
 969                                                        mshcfg->power_mode);
 970                         break;
 971                 default:
 972                         spin_unlock_bh(&sta->lock);
 973                         break;
 974                 }
 975                 break;
 976
 977         case NL80211_PLINK_CNF_RCVD:
 978                 switch (event) {
 979                 case OPN_RJCT:
 980                 case CNF_RJCT:
 981                         reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 982                 case CLS_ACPT:
 983                         if (!reason)
 984                                 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 985                         sta->reason = reason;
 986                         sta->plink_state = NL80211_PLINK_HOLDING;
 987                         if (!mod_plink_timer(sta,
 988                                              mshcfg->dot11MeshHoldingTimeout))
 989                                 sta->ignore_plink_timer = true;
 990
 991                         llid = sta->llid;
 992                         spin_unlock_bh(&sta->lock);
 993                         mesh_plink_frame_tx(sdata,
 994                                             WLAN_SP_MESH_PEERING_CLOSE,
 995                                             sta->sta.addr, llid, plid, reason);
 996                         break;
 997                 case OPN_ACPT:
 998                         del_timer(&sta->plink_timer);
 999                         sta->plink_state = NL80211_PLINK_ESTAB;
1000                         spin_unlock_bh(&sta->lock);
1001                         changed |= mesh_plink_inc_estab_count(sdata);
1002                         changed |= mesh_set_ht_prot_mode(sdata);
1003                         changed |= mesh_set_short_slot_time(sdata);
1004                         mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
1005                                 sta->sta.addr);
1006                         mesh_plink_frame_tx(sdata,
1007                                             WLAN_SP_MESH_PEERING_CONFIRM,
1008                                             sta->sta.addr, llid, plid, 0);
1009                         ieee80211_mps_sta_status_update(sta);
1010                         changed |= ieee80211_mps_set_sta_local_pm(sta,
1011                                                         mshcfg->power_mode);
1012                         break;
1013                 default:
1014                         spin_unlock_bh(&sta->lock);
1015                         break;
1016                 }
1017                 break;
1018
1019         case NL80211_PLINK_ESTAB:
1020                 switch (event) {
1021                 case CLS_ACPT:
1022                         reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
1023                         sta->reason = reason;
1024                         changed |= __mesh_plink_deactivate(sta);
1025                         sta->plink_state = NL80211_PLINK_HOLDING;
1026                         llid = sta->llid;
1027                         mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
1028                         spin_unlock_bh(&sta->lock);
1029                         changed |= mesh_set_ht_prot_mode(sdata);
1030                         changed |= mesh_set_short_slot_time(sdata);
1031                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1032                                             sta->sta.addr, llid, plid, reason);
1033                         break;
1034                 case OPN_ACPT:
1035                         llid = sta->llid;
1036                         spin_unlock_bh(&sta->lock);
1037                         mesh_plink_frame_tx(sdata,
1038                                             WLAN_SP_MESH_PEERING_CONFIRM,
1039                                             sta->sta.addr, llid, plid, 0);
1040                         break;
1041                 default:
1042                         spin_unlock_bh(&sta->lock);
1043                         break;
1044                 }
1045                 break;
1046         case NL80211_PLINK_HOLDING:
1047                 switch (event) {
1048                 case CLS_ACPT:
1049                         if (del_timer(&sta->plink_timer))
1050                                 sta->ignore_plink_timer = 1;
1051                         mesh_plink_fsm_restart(sta);
1052                         spin_unlock_bh(&sta->lock);
1053                         break;
1054                 case OPN_ACPT:
1055                 case CNF_ACPT:
1056                 case OPN_RJCT:
1057                 case CNF_RJCT:
1058                         llid = sta->llid;
1059                         reason = sta->reason;
1060                         spin_unlock_bh(&sta->lock);
1061                         mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1062                                             sta->sta.addr, llid, plid, reason);
1063                         break;
1064                 default:
1065                         spin_unlock_bh(&sta->lock);
1066                 }
1067                 break;
1068         default:
1069                 /* should not get here, PLINK_BLOCKED is dealt with at the
1070                  * beginning of the function
1071                  */
1072                 spin_unlock_bh(&sta->lock);
1073                 break;
1074         }
1075
1076         rcu_read_unlock();
1077
1078         if (changed)
1079                 ieee80211_mbss_info_change_notify(sdata, changed);
1080 }