linux/net/mac80211/mesh_plink.c
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   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
  28enum 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
  40static 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
  50static 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
  62static 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 */
  73static 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 */
  90static 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
 130out:
 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 */
 150static 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 */
 214static u32 __mesh_plink_deactivate(struct sta_info *sta)
 215{
 216        struct ieee80211_sub_if_data *sdata = sta->sdata;
 217        u32 changed = 0;
 218
 219        if (sta->plink_state == NL80211_PLINK_ESTAB)
 220                changed = mesh_plink_dec_estab_count(sdata);
 221        sta->plink_state = NL80211_PLINK_BLOCKED;
 222        mesh_path_flush_by_nexthop(sta);
 223
 224        ieee80211_mps_sta_status_update(sta);
 225        changed |= ieee80211_mps_local_status_update(sdata);
 226
 227        return changed;
 228}
 229
 230/**
 231 * mesh_plink_deactivate - deactivate mesh peer link
 232 *
 233 * @sta: mesh peer link to deactivate
 234 *
 235 * All mesh paths with this peer as next hop will be flushed
 236 */
 237u32 mesh_plink_deactivate(struct sta_info *sta)
 238{
 239        struct ieee80211_sub_if_data *sdata = sta->sdata;
 240        u32 changed;
 241
 242        spin_lock_bh(&sta->lock);
 243        changed = __mesh_plink_deactivate(sta);
 244        sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 245        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 246                            sta->sta.addr, sta->llid, sta->plid,
 247                            sta->reason);
 248        spin_unlock_bh(&sta->lock);
 249
 250        return changed;
 251}
 252
 253static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 254                               enum ieee80211_self_protected_actioncode action,
 255                               u8 *da, __le16 llid, __le16 plid, __le16 reason)
 256{
 257        struct ieee80211_local *local = sdata->local;
 258        struct sk_buff *skb;
 259        struct ieee80211_tx_info *info;
 260        struct ieee80211_mgmt *mgmt;
 261        bool include_plid = false;
 262        u16 peering_proto = 0;
 263        u8 *pos, ie_len = 4;
 264        int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 265                      sizeof(mgmt->u.action.u.self_prot);
 266        int err = -ENOMEM;
 267
 268        skb = dev_alloc_skb(local->tx_headroom +
 269                            hdr_len +
 270                            2 + /* capability info */
 271                            2 + /* AID */
 272                            2 + 8 + /* supported rates */
 273                            2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 274                            2 + sdata->u.mesh.mesh_id_len +
 275                            2 + sizeof(struct ieee80211_meshconf_ie) +
 276                            2 + sizeof(struct ieee80211_ht_cap) +
 277                            2 + sizeof(struct ieee80211_ht_operation) +
 278                            2 + 8 + /* peering IE */
 279                            sdata->u.mesh.ie_len);
 280        if (!skb)
 281                return -1;
 282        info = IEEE80211_SKB_CB(skb);
 283        skb_reserve(skb, local->tx_headroom);
 284        mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 285        memset(mgmt, 0, hdr_len);
 286        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 287                                          IEEE80211_STYPE_ACTION);
 288        memcpy(mgmt->da, da, ETH_ALEN);
 289        memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 290        memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 291        mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 292        mgmt->u.action.u.self_prot.action_code = action;
 293
 294        if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 295                enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 296
 297                /* capability info */
 298                pos = skb_put(skb, 2);
 299                memset(pos, 0, 2);
 300                if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 301                        /* AID */
 302                        pos = skb_put(skb, 2);
 303                        memcpy(pos + 2, &plid, 2);
 304                }
 305                if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 306                    ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 307                    mesh_add_rsn_ie(sdata, skb) ||
 308                    mesh_add_meshid_ie(sdata, skb) ||
 309                    mesh_add_meshconf_ie(sdata, skb))
 310                        goto free;
 311        } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 312                info->flags |= IEEE80211_TX_CTL_NO_ACK;
 313                if (mesh_add_meshid_ie(sdata, skb))
 314                        goto free;
 315        }
 316
 317        /* Add Mesh Peering Management element */
 318        switch (action) {
 319        case WLAN_SP_MESH_PEERING_OPEN:
 320                break;
 321        case WLAN_SP_MESH_PEERING_CONFIRM:
 322                ie_len += 2;
 323                include_plid = true;
 324                break;
 325        case WLAN_SP_MESH_PEERING_CLOSE:
 326                if (plid) {
 327                        ie_len += 2;
 328                        include_plid = true;
 329                }
 330                ie_len += 2;    /* reason code */
 331                break;
 332        default:
 333                err = -EINVAL;
 334                goto free;
 335        }
 336
 337        if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 338                goto free;
 339
 340        pos = skb_put(skb, 2 + ie_len);
 341        *pos++ = WLAN_EID_PEER_MGMT;
 342        *pos++ = ie_len;
 343        memcpy(pos, &peering_proto, 2);
 344        pos += 2;
 345        memcpy(pos, &llid, 2);
 346        pos += 2;
 347        if (include_plid) {
 348                memcpy(pos, &plid, 2);
 349                pos += 2;
 350        }
 351        if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 352                memcpy(pos, &reason, 2);
 353                pos += 2;
 354        }
 355
 356        if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 357                if (mesh_add_ht_cap_ie(sdata, skb) ||
 358                    mesh_add_ht_oper_ie(sdata, skb))
 359                        goto free;
 360        }
 361
 362        if (mesh_add_vendor_ies(sdata, skb))
 363                goto free;
 364
 365        ieee80211_tx_skb(sdata, skb);
 366        return 0;
 367free:
 368        kfree_skb(skb);
 369        return err;
 370}
 371
 372static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 373                               struct sta_info *sta,
 374                               struct ieee802_11_elems *elems, bool insert)
 375{
 376        struct ieee80211_local *local = sdata->local;
 377        enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 378        struct ieee80211_supported_band *sband;
 379        u32 rates, basic_rates = 0, changed = 0;
 380
 381        sband = local->hw.wiphy->bands[band];
 382        rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates);
 383
 384        spin_lock_bh(&sta->lock);
 385        sta->last_rx = jiffies;
 386
 387        /* rates and capabilities don't change during peering */
 388        if (sta->plink_state == NL80211_PLINK_ESTAB)
 389                goto out;
 390
 391        if (sta->sta.supp_rates[band] != rates)
 392                changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 393        sta->sta.supp_rates[band] = rates;
 394
 395        if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 396                                              elems->ht_cap_elem, sta))
 397                changed |= IEEE80211_RC_BW_CHANGED;
 398
 399        /* HT peer is operating 20MHz-only */
 400        if (elems->ht_operation &&
 401            !(elems->ht_operation->ht_param &
 402              IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 403                if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 404                        changed |= IEEE80211_RC_BW_CHANGED;
 405                sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 406        }
 407
 408        if (insert)
 409                rate_control_rate_init(sta);
 410        else
 411                rate_control_rate_update(local, sband, sta, changed);
 412out:
 413        spin_unlock_bh(&sta->lock);
 414}
 415
 416static struct sta_info *
 417__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 418{
 419        struct sta_info *sta;
 420
 421        if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 422                return NULL;
 423
 424        sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 425        if (!sta)
 426                return NULL;
 427
 428        sta->plink_state = NL80211_PLINK_LISTEN;
 429
 430        sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 431        sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 432        sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 433
 434        set_sta_flag(sta, WLAN_STA_WME);
 435
 436        return sta;
 437}
 438
 439static struct sta_info *
 440mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 441                    struct ieee802_11_elems *elems)
 442{
 443        struct sta_info *sta = NULL;
 444
 445        /* Userspace handles station allocation */
 446        if (sdata->u.mesh.user_mpm ||
 447            sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
 448                cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 449                                                   elems->ie_start,
 450                                                   elems->total_len,
 451                                                   GFP_KERNEL);
 452        else
 453                sta = __mesh_sta_info_alloc(sdata, addr);
 454
 455        return sta;
 456}
 457
 458/*
 459 * mesh_sta_info_get - return mesh sta info entry for @addr.
 460 *
 461 * @sdata: local meshif
 462 * @addr: peer's address
 463 * @elems: IEs from beacon or mesh peering frame.
 464 *
 465 * Return existing or newly allocated sta_info under RCU read lock.
 466 * (re)initialize with given IEs.
 467 */
 468static struct sta_info *
 469mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 470                  u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU)
 471{
 472        struct sta_info *sta = NULL;
 473
 474        rcu_read_lock();
 475        sta = sta_info_get(sdata, addr);
 476        if (sta) {
 477                mesh_sta_info_init(sdata, sta, elems, false);
 478        } else {
 479                rcu_read_unlock();
 480                /* can't run atomic */
 481                sta = mesh_sta_info_alloc(sdata, addr, elems);
 482                if (!sta) {
 483                        rcu_read_lock();
 484                        return NULL;
 485                }
 486
 487                mesh_sta_info_init(sdata, sta, elems, true);
 488
 489                if (sta_info_insert_rcu(sta))
 490                        return NULL;
 491        }
 492
 493        return sta;
 494}
 495
 496/*
 497 * mesh_neighbour_update - update or initialize new mesh neighbor.
 498 *
 499 * @sdata: local meshif
 500 * @addr: peer's address
 501 * @elems: IEs from beacon or mesh peering frame
 502 *
 503 * Initiates peering if appropriate.
 504 */
 505void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 506                           u8 *hw_addr,
 507                           struct ieee802_11_elems *elems)
 508{
 509        struct sta_info *sta;
 510        u32 changed = 0;
 511
 512        sta = mesh_sta_info_get(sdata, hw_addr, elems);
 513        if (!sta)
 514                goto out;
 515
 516        if (mesh_peer_accepts_plinks(elems) &&
 517            sta->plink_state == NL80211_PLINK_LISTEN &&
 518            sdata->u.mesh.accepting_plinks &&
 519            sdata->u.mesh.mshcfg.auto_open_plinks &&
 520            rssi_threshold_check(sta, sdata))
 521                changed = mesh_plink_open(sta);
 522
 523        ieee80211_mps_frame_release(sta, elems);
 524out:
 525        rcu_read_unlock();
 526        ieee80211_mbss_info_change_notify(sdata, changed);
 527}
 528
 529static void mesh_plink_timer(unsigned long data)
 530{
 531        struct sta_info *sta;
 532        __le16 llid, plid, reason;
 533        struct ieee80211_sub_if_data *sdata;
 534        struct mesh_config *mshcfg;
 535
 536        /*
 537         * This STA is valid because sta_info_destroy() will
 538         * del_timer_sync() this timer after having made sure
 539         * it cannot be readded (by deleting the plink.)
 540         */
 541        sta = (struct sta_info *) data;
 542
 543        if (sta->sdata->local->quiescing)
 544                return;
 545
 546        spin_lock_bh(&sta->lock);
 547        if (sta->ignore_plink_timer) {
 548                sta->ignore_plink_timer = false;
 549                spin_unlock_bh(&sta->lock);
 550                return;
 551        }
 552        mpl_dbg(sta->sdata,
 553                "Mesh plink timer for %pM fired on state %s\n",
 554                sta->sta.addr, mplstates[sta->plink_state]);
 555        reason = 0;
 556        llid = sta->llid;
 557        plid = sta->plid;
 558        sdata = sta->sdata;
 559        mshcfg = &sdata->u.mesh.mshcfg;
 560
 561        switch (sta->plink_state) {
 562        case NL80211_PLINK_OPN_RCVD:
 563        case NL80211_PLINK_OPN_SNT:
 564                /* retry timer */
 565                if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) {
 566                        u32 rand;
 567                        mpl_dbg(sta->sdata,
 568                                "Mesh plink for %pM (retry, timeout): %d %d\n",
 569                                sta->sta.addr, sta->plink_retries,
 570                                sta->plink_timeout);
 571                        get_random_bytes(&rand, sizeof(u32));
 572                        sta->plink_timeout = sta->plink_timeout +
 573                                             rand % sta->plink_timeout;
 574                        ++sta->plink_retries;
 575                        mod_plink_timer(sta, sta->plink_timeout);
 576                        spin_unlock_bh(&sta->lock);
 577                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 578                                            sta->sta.addr, llid, 0, 0);
 579                        break;
 580                }
 581                reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 582                /* fall through on else */
 583        case NL80211_PLINK_CNF_RCVD:
 584                /* confirm timer */
 585                if (!reason)
 586                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 587                sta->plink_state = NL80211_PLINK_HOLDING;
 588                mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 589                spin_unlock_bh(&sta->lock);
 590                mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 591                                    sta->sta.addr, llid, plid, reason);
 592                break;
 593        case NL80211_PLINK_HOLDING:
 594                /* holding timer */
 595                del_timer(&sta->plink_timer);
 596                mesh_plink_fsm_restart(sta);
 597                spin_unlock_bh(&sta->lock);
 598                break;
 599        default:
 600                spin_unlock_bh(&sta->lock);
 601                break;
 602        }
 603}
 604
 605static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 606{
 607        sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 608        sta->plink_timer.data = (unsigned long) sta;
 609        sta->plink_timer.function = mesh_plink_timer;
 610        sta->plink_timeout = timeout;
 611        add_timer(&sta->plink_timer);
 612}
 613
 614u32 mesh_plink_open(struct sta_info *sta)
 615{
 616        __le16 llid;
 617        struct ieee80211_sub_if_data *sdata = sta->sdata;
 618        u32 changed;
 619
 620        if (!test_sta_flag(sta, WLAN_STA_AUTH))
 621                return 0;
 622
 623        spin_lock_bh(&sta->lock);
 624        get_random_bytes(&llid, 2);
 625        sta->llid = llid;
 626        if (sta->plink_state != NL80211_PLINK_LISTEN &&
 627            sta->plink_state != NL80211_PLINK_BLOCKED) {
 628                spin_unlock_bh(&sta->lock);
 629                return 0;
 630        }
 631        sta->plink_state = NL80211_PLINK_OPN_SNT;
 632        mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 633        spin_unlock_bh(&sta->lock);
 634        mpl_dbg(sdata,
 635                "Mesh plink: starting establishment with %pM\n",
 636                sta->sta.addr);
 637
 638        /* set the non-peer mode to active during peering */
 639        changed = ieee80211_mps_local_status_update(sdata);
 640
 641        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 642                            sta->sta.addr, llid, 0, 0);
 643        return changed;
 644}
 645
 646u32 mesh_plink_block(struct sta_info *sta)
 647{
 648        u32 changed;
 649
 650        spin_lock_bh(&sta->lock);
 651        changed = __mesh_plink_deactivate(sta);
 652        sta->plink_state = NL80211_PLINK_BLOCKED;
 653        spin_unlock_bh(&sta->lock);
 654
 655        return changed;
 656}
 657
 658
 659void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 660                         struct ieee80211_mgmt *mgmt, size_t len,
 661                         struct ieee80211_rx_status *rx_status)
 662{
 663        struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 664        struct ieee802_11_elems elems;
 665        struct sta_info *sta;
 666        enum plink_event event;
 667        enum ieee80211_self_protected_actioncode ftype;
 668        size_t baselen;
 669        bool matches_local = true;
 670        u8 ie_len;
 671        u8 *baseaddr;
 672        u32 changed = 0;
 673        __le16 plid, llid, reason;
 674
 675        /* need action_code, aux */
 676        if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 677                return;
 678
 679        if (sdata->u.mesh.user_mpm)
 680                /* userspace must register for these */
 681                return;
 682
 683        if (is_multicast_ether_addr(mgmt->da)) {
 684                mpl_dbg(sdata,
 685                        "Mesh plink: ignore frame from multicast address\n");
 686                return;
 687        }
 688
 689        baseaddr = mgmt->u.action.u.self_prot.variable;
 690        baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 691        if (mgmt->u.action.u.self_prot.action_code ==
 692                                                WLAN_SP_MESH_PEERING_CONFIRM) {
 693                baseaddr += 4;
 694                baselen += 4;
 695        }
 696        ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems);
 697
 698        if (!elems.peering) {
 699                mpl_dbg(sdata,
 700                        "Mesh plink: missing necessary peer link ie\n");
 701                return;
 702        }
 703
 704        if (elems.rsn_len &&
 705            sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 706                mpl_dbg(sdata,
 707                        "Mesh plink: can't establish link with secure peer\n");
 708                return;
 709        }
 710
 711        ftype = mgmt->u.action.u.self_prot.action_code;
 712        ie_len = elems.peering_len;
 713        if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 714            (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 715            (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 716                                                        && ie_len != 8)) {
 717                mpl_dbg(sdata,
 718                        "Mesh plink: incorrect plink ie length %d %d\n",
 719                        ftype, ie_len);
 720                return;
 721        }
 722
 723        if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 724            (!elems.mesh_id || !elems.mesh_config)) {
 725                mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
 726                return;
 727        }
 728        /* Note the lines below are correct, the llid in the frame is the plid
 729         * from the point of view of this host.
 730         */
 731        memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 732        if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 733            (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 734                memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 735
 736        /* WARNING: Only for sta pointer, is dropped & re-acquired */
 737        rcu_read_lock();
 738
 739        sta = sta_info_get(sdata, mgmt->sa);
 740        if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 741                mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 742                rcu_read_unlock();
 743                return;
 744        }
 745
 746        if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 747            !rssi_threshold_check(sta, sdata)) {
 748                mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
 749                        mgmt->sa);
 750                rcu_read_unlock();
 751                return;
 752        }
 753
 754        if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 755                mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
 756                rcu_read_unlock();
 757                return;
 758        }
 759
 760        if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 761                rcu_read_unlock();
 762                return;
 763        }
 764
 765        /* Now we will figure out the appropriate event... */
 766        event = PLINK_UNDEFINED;
 767        if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 768            !mesh_matches_local(sdata, &elems)) {
 769                matches_local = false;
 770                switch (ftype) {
 771                case WLAN_SP_MESH_PEERING_OPEN:
 772                        event = OPN_RJCT;
 773                        break;
 774                case WLAN_SP_MESH_PEERING_CONFIRM:
 775                        event = CNF_RJCT;
 776                        break;
 777                default:
 778                        break;
 779                }
 780        }
 781
 782        if (!sta && !matches_local) {
 783                rcu_read_unlock();
 784                reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 785                llid = 0;
 786                mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 787                                    mgmt->sa, llid, plid, reason);
 788                return;
 789        } else if (!sta) {
 790                /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 791                if (!mesh_plink_free_count(sdata)) {
 792                        mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 793                        rcu_read_unlock();
 794                        return;
 795                }
 796                event = OPN_ACPT;
 797        } else if (matches_local) {
 798                switch (ftype) {
 799                case WLAN_SP_MESH_PEERING_OPEN:
 800                        if (!mesh_plink_free_count(sdata) ||
 801                            (sta->plid && sta->plid != plid))
 802                                event = OPN_IGNR;
 803                        else
 804                                event = OPN_ACPT;
 805                        break;
 806                case WLAN_SP_MESH_PEERING_CONFIRM:
 807                        if (!mesh_plink_free_count(sdata) ||
 808                            (sta->llid != llid || sta->plid != plid))
 809                                event = CNF_IGNR;
 810                        else
 811                                event = CNF_ACPT;
 812                        break;
 813                case WLAN_SP_MESH_PEERING_CLOSE:
 814                        if (sta->plink_state == NL80211_PLINK_ESTAB)
 815                                /* Do not check for llid or plid. This does not
 816                                 * follow the standard but since multiple plinks
 817                                 * per sta are not supported, it is necessary in
 818                                 * order to avoid a livelock when MP A sees an
 819                                 * establish peer link to MP B but MP B does not
 820                                 * see it. This can be caused by a timeout in
 821                                 * B's peer link establishment or B beign
 822                                 * restarted.
 823                                 */
 824                                event = CLS_ACPT;
 825                        else if (sta->plid != plid)
 826                                event = CLS_IGNR;
 827                        else if (ie_len == 7 && sta->llid != llid)
 828                                event = CLS_IGNR;
 829                        else
 830                                event = CLS_ACPT;
 831                        break;
 832                default:
 833                        mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
 834                        rcu_read_unlock();
 835                        return;
 836                }
 837        }
 838
 839        if (event == OPN_ACPT) {
 840                rcu_read_unlock();
 841                /* allocate sta entry if necessary and update info */
 842                sta = mesh_sta_info_get(sdata, mgmt->sa, &elems);
 843                if (!sta) {
 844                        mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
 845                        rcu_read_unlock();
 846                        return;
 847                }
 848        }
 849
 850        mpl_dbg(sdata, "peer %pM in state %s got event %s\n", mgmt->sa,
 851                       mplstates[sta->plink_state], mplevents[event]);
 852        reason = 0;
 853        spin_lock_bh(&sta->lock);
 854        switch (sta->plink_state) {
 855                /* spin_unlock as soon as state is updated at each case */
 856        case NL80211_PLINK_LISTEN:
 857                switch (event) {
 858                case CLS_ACPT:
 859                        mesh_plink_fsm_restart(sta);
 860                        spin_unlock_bh(&sta->lock);
 861                        break;
 862                case OPN_ACPT:
 863                        sta->plink_state = NL80211_PLINK_OPN_RCVD;
 864                        sta->plid = plid;
 865                        get_random_bytes(&llid, 2);
 866                        sta->llid = llid;
 867                        mesh_plink_timer_set(sta,
 868                                             mshcfg->dot11MeshRetryTimeout);
 869
 870                        /* set the non-peer mode to active during peering */
 871                        changed |= ieee80211_mps_local_status_update(sdata);
 872
 873                        spin_unlock_bh(&sta->lock);
 874                        mesh_plink_frame_tx(sdata,
 875                                            WLAN_SP_MESH_PEERING_OPEN,
 876                                            sta->sta.addr, llid, 0, 0);
 877                        mesh_plink_frame_tx(sdata,
 878                                            WLAN_SP_MESH_PEERING_CONFIRM,
 879                                            sta->sta.addr, llid, plid, 0);
 880                        break;
 881                default:
 882                        spin_unlock_bh(&sta->lock);
 883                        break;
 884                }
 885                break;
 886
 887        case NL80211_PLINK_OPN_SNT:
 888                switch (event) {
 889                case OPN_RJCT:
 890                case CNF_RJCT:
 891                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 892                case CLS_ACPT:
 893                        if (!reason)
 894                                reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 895                        sta->reason = reason;
 896                        sta->plink_state = NL80211_PLINK_HOLDING;
 897                        if (!mod_plink_timer(sta,
 898                                             mshcfg->dot11MeshHoldingTimeout))
 899                                sta->ignore_plink_timer = true;
 900
 901                        llid = sta->llid;
 902                        spin_unlock_bh(&sta->lock);
 903                        mesh_plink_frame_tx(sdata,
 904                                            WLAN_SP_MESH_PEERING_CLOSE,
 905                                            sta->sta.addr, llid, plid, reason);
 906                        break;
 907                case OPN_ACPT:
 908                        /* retry timer is left untouched */
 909                        sta->plink_state = NL80211_PLINK_OPN_RCVD;
 910                        sta->plid = plid;
 911                        llid = sta->llid;
 912                        spin_unlock_bh(&sta->lock);
 913                        mesh_plink_frame_tx(sdata,
 914                                            WLAN_SP_MESH_PEERING_CONFIRM,
 915                                            sta->sta.addr, llid, plid, 0);
 916                        break;
 917                case CNF_ACPT:
 918                        sta->plink_state = NL80211_PLINK_CNF_RCVD;
 919                        if (!mod_plink_timer(sta,
 920                                             mshcfg->dot11MeshConfirmTimeout))
 921                                sta->ignore_plink_timer = true;
 922
 923                        spin_unlock_bh(&sta->lock);
 924                        break;
 925                default:
 926                        spin_unlock_bh(&sta->lock);
 927                        break;
 928                }
 929                break;
 930
 931        case NL80211_PLINK_OPN_RCVD:
 932                switch (event) {
 933                case OPN_RJCT:
 934                case CNF_RJCT:
 935                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 936                case CLS_ACPT:
 937                        if (!reason)
 938                                reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 939                        sta->reason = reason;
 940                        sta->plink_state = NL80211_PLINK_HOLDING;
 941                        if (!mod_plink_timer(sta,
 942                                             mshcfg->dot11MeshHoldingTimeout))
 943                                sta->ignore_plink_timer = true;
 944
 945                        llid = sta->llid;
 946                        spin_unlock_bh(&sta->lock);
 947                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 948                                            sta->sta.addr, llid, plid, reason);
 949                        break;
 950                case OPN_ACPT:
 951                        llid = sta->llid;
 952                        spin_unlock_bh(&sta->lock);
 953                        mesh_plink_frame_tx(sdata,
 954                                            WLAN_SP_MESH_PEERING_CONFIRM,
 955                                            sta->sta.addr, llid, plid, 0);
 956                        break;
 957                case CNF_ACPT:
 958                        del_timer(&sta->plink_timer);
 959                        sta->plink_state = NL80211_PLINK_ESTAB;
 960                        spin_unlock_bh(&sta->lock);
 961                        changed |= mesh_plink_inc_estab_count(sdata);
 962                        changed |= mesh_set_ht_prot_mode(sdata);
 963                        changed |= mesh_set_short_slot_time(sdata);
 964                        mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 965                                sta->sta.addr);
 966                        ieee80211_mps_sta_status_update(sta);
 967                        changed |= ieee80211_mps_set_sta_local_pm(sta,
 968                                                       mshcfg->power_mode);
 969                        break;
 970                default:
 971                        spin_unlock_bh(&sta->lock);
 972                        break;
 973                }
 974                break;
 975
 976        case NL80211_PLINK_CNF_RCVD:
 977                switch (event) {
 978                case OPN_RJCT:
 979                case CNF_RJCT:
 980                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 981                case CLS_ACPT:
 982                        if (!reason)
 983                                reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 984                        sta->reason = reason;
 985                        sta->plink_state = NL80211_PLINK_HOLDING;
 986                        if (!mod_plink_timer(sta,
 987                                             mshcfg->dot11MeshHoldingTimeout))
 988                                sta->ignore_plink_timer = true;
 989
 990                        llid = sta->llid;
 991                        spin_unlock_bh(&sta->lock);
 992                        mesh_plink_frame_tx(sdata,
 993                                            WLAN_SP_MESH_PEERING_CLOSE,
 994                                            sta->sta.addr, llid, plid, reason);
 995                        break;
 996                case OPN_ACPT:
 997                        del_timer(&sta->plink_timer);
 998                        sta->plink_state = NL80211_PLINK_ESTAB;
 999                        spin_unlock_bh(&sta->lock);
1000                        changed |= mesh_plink_inc_estab_count(sdata);
1001                        changed |= mesh_set_ht_prot_mode(sdata);
1002                        changed |= mesh_set_short_slot_time(sdata);
1003                        mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
1004                                sta->sta.addr);
1005                        mesh_plink_frame_tx(sdata,
1006                                            WLAN_SP_MESH_PEERING_CONFIRM,
1007                                            sta->sta.addr, llid, plid, 0);
1008                        ieee80211_mps_sta_status_update(sta);
1009                        changed |= ieee80211_mps_set_sta_local_pm(sta,
1010                                                        mshcfg->power_mode);
1011                        break;
1012                default:
1013                        spin_unlock_bh(&sta->lock);
1014                        break;
1015                }
1016                break;
1017
1018        case NL80211_PLINK_ESTAB:
1019                switch (event) {
1020                case CLS_ACPT:
1021                        reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
1022                        sta->reason = reason;
1023                        changed |= __mesh_plink_deactivate(sta);
1024                        sta->plink_state = NL80211_PLINK_HOLDING;
1025                        llid = sta->llid;
1026                        mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
1027                        spin_unlock_bh(&sta->lock);
1028                        changed |= mesh_set_ht_prot_mode(sdata);
1029                        changed |= mesh_set_short_slot_time(sdata);
1030                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1031                                            sta->sta.addr, llid, plid, reason);
1032                        break;
1033                case OPN_ACPT:
1034                        llid = sta->llid;
1035                        spin_unlock_bh(&sta->lock);
1036                        mesh_plink_frame_tx(sdata,
1037                                            WLAN_SP_MESH_PEERING_CONFIRM,
1038                                            sta->sta.addr, llid, plid, 0);
1039                        break;
1040                default:
1041                        spin_unlock_bh(&sta->lock);
1042                        break;
1043                }
1044                break;
1045        case NL80211_PLINK_HOLDING:
1046                switch (event) {
1047                case CLS_ACPT:
1048                        if (del_timer(&sta->plink_timer))
1049                                sta->ignore_plink_timer = 1;
1050                        mesh_plink_fsm_restart(sta);
1051                        spin_unlock_bh(&sta->lock);
1052                        break;
1053                case OPN_ACPT:
1054                case CNF_ACPT:
1055                case OPN_RJCT:
1056                case CNF_RJCT:
1057                        llid = sta->llid;
1058                        reason = sta->reason;
1059                        spin_unlock_bh(&sta->lock);
1060                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
1061                                            sta->sta.addr, llid, plid, reason);
1062                        break;
1063                default:
1064                        spin_unlock_bh(&sta->lock);
1065                }
1066                break;
1067        default:
1068                /* should not get here, PLINK_BLOCKED is dealt with at the
1069                 * beginning of the function
1070                 */
1071                spin_unlock_bh(&sta->lock);
1072                break;
1073        }
1074
1075        rcu_read_unlock();
1076
1077        if (changed)
1078                ieee80211_mbss_info_change_notify(sdata, changed);
1079}
1080