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#define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
  23#define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
  24#define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
  25#define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
  26#define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
  27
  28/* We only need a valid sta if user configured a minimum rssi_threshold. */
  29#define rssi_threshold_check(sta, sdata) \
  30                (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
  31                (sta && (s8) -ewma_read(&sta->avg_signal) > \
  32                sdata->u.mesh.mshcfg.rssi_threshold))
  33
  34enum plink_event {
  35        PLINK_UNDEFINED,
  36        OPN_ACPT,
  37        OPN_RJCT,
  38        OPN_IGNR,
  39        CNF_ACPT,
  40        CNF_RJCT,
  41        CNF_IGNR,
  42        CLS_ACPT,
  43        CLS_IGNR
  44};
  45
  46static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
  47                enum ieee80211_self_protected_actioncode action,
  48                u8 *da, __le16 llid, __le16 plid, __le16 reason);
  49
  50static inline
  51u32 mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
  52{
  53        atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
  54        return mesh_accept_plinks_update(sdata);
  55}
  56
  57static inline
  58u32 mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
  59{
  60        atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
  61        return mesh_accept_plinks_update(sdata);
  62}
  63
  64/**
  65 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  66 *
  67 * @sta: mesh peer link to restart
  68 *
  69 * Locking: this function must be called holding sta->lock
  70 */
  71static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  72{
  73        sta->plink_state = NL80211_PLINK_LISTEN;
  74        sta->llid = sta->plid = sta->reason = 0;
  75        sta->plink_retries = 0;
  76}
  77
  78/*
  79 * Allocate mesh sta entry and insert into station table
  80 */
  81static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
  82                                         u8 *hw_addr)
  83{
  84        struct sta_info *sta;
  85
  86        if (sdata->local->num_sta >= MESH_MAX_PLINKS)
  87                return NULL;
  88
  89        sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
  90        if (!sta)
  91                return NULL;
  92
  93        sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
  94        sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
  95        sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
  96
  97        set_sta_flag(sta, WLAN_STA_WME);
  98
  99        return sta;
 100}
 101
 102/**
 103 * mesh_set_ht_prot_mode - set correct HT protection mode
 104 *
 105 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 106 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 107 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 108 * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 109 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 110 * HT20 peer is present. Otherwise no-protection mode is selected.
 111 */
 112static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 113{
 114        struct ieee80211_local *local = sdata->local;
 115        struct sta_info *sta;
 116        u32 changed = 0;
 117        u16 ht_opmode;
 118        bool non_ht_sta = false, ht20_sta = false;
 119
 120        if (sdata->vif.bss_conf.channel_type == NL80211_CHAN_NO_HT)
 121                return 0;
 122
 123        rcu_read_lock();
 124        list_for_each_entry_rcu(sta, &local->sta_list, list) {
 125                if (sdata != sta->sdata ||
 126                    sta->plink_state != NL80211_PLINK_ESTAB)
 127                        continue;
 128
 129                switch (sta->ch_type) {
 130                case NL80211_CHAN_NO_HT:
 131                        mpl_dbg(sdata,
 132                                "mesh_plink %pM: nonHT sta (%pM) is present\n",
 133                                sdata->vif.addr, sta->sta.addr);
 134                        non_ht_sta = true;
 135                        goto out;
 136                case NL80211_CHAN_HT20:
 137                        mpl_dbg(sdata,
 138                                "mesh_plink %pM: HT20 sta (%pM) is present\n",
 139                                sdata->vif.addr, sta->sta.addr);
 140                        ht20_sta = true;
 141                default:
 142                        break;
 143                }
 144        }
 145out:
 146        rcu_read_unlock();
 147
 148        if (non_ht_sta)
 149                ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 150        else if (ht20_sta &&
 151                 sdata->vif.bss_conf.channel_type > NL80211_CHAN_HT20)
 152                ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 153        else
 154                ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 155
 156        if (sdata->vif.bss_conf.ht_operation_mode != ht_opmode) {
 157                sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 158                sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 159                changed = BSS_CHANGED_HT;
 160                mpl_dbg(sdata,
 161                        "mesh_plink %pM: protection mode changed to %d\n",
 162                        sdata->vif.addr, ht_opmode);
 163        }
 164
 165        return changed;
 166}
 167
 168/**
 169 * __mesh_plink_deactivate - deactivate mesh peer link
 170 *
 171 * @sta: mesh peer link to deactivate
 172 *
 173 * All mesh paths with this peer as next hop will be flushed
 174 * Returns beacon changed flag if the beacon content changed.
 175 *
 176 * Locking: the caller must hold sta->lock
 177 */
 178static u32 __mesh_plink_deactivate(struct sta_info *sta)
 179{
 180        struct ieee80211_sub_if_data *sdata = sta->sdata;
 181        u32 changed = 0;
 182
 183        if (sta->plink_state == NL80211_PLINK_ESTAB)
 184                changed = mesh_plink_dec_estab_count(sdata);
 185        sta->plink_state = NL80211_PLINK_BLOCKED;
 186        mesh_path_flush_by_nexthop(sta);
 187
 188        return changed;
 189}
 190
 191/**
 192 * mesh_plink_deactivate - deactivate mesh peer link
 193 *
 194 * @sta: mesh peer link to deactivate
 195 *
 196 * All mesh paths with this peer as next hop will be flushed
 197 */
 198void mesh_plink_deactivate(struct sta_info *sta)
 199{
 200        struct ieee80211_sub_if_data *sdata = sta->sdata;
 201        u32 changed;
 202
 203        spin_lock_bh(&sta->lock);
 204        changed = __mesh_plink_deactivate(sta);
 205        sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED);
 206        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 207                            sta->sta.addr, sta->llid, sta->plid,
 208                            sta->reason);
 209        spin_unlock_bh(&sta->lock);
 210
 211        ieee80211_bss_info_change_notify(sdata, changed);
 212}
 213
 214static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 215                enum ieee80211_self_protected_actioncode action,
 216                u8 *da, __le16 llid, __le16 plid, __le16 reason) {
 217        struct ieee80211_local *local = sdata->local;
 218        struct sk_buff *skb;
 219        struct ieee80211_tx_info *info;
 220        struct ieee80211_mgmt *mgmt;
 221        bool include_plid = false;
 222        u16 peering_proto = 0;
 223        u8 *pos, ie_len = 4;
 224        int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) +
 225                      sizeof(mgmt->u.action.u.self_prot);
 226        int err = -ENOMEM;
 227
 228        skb = dev_alloc_skb(local->tx_headroom +
 229                            hdr_len +
 230                            2 + /* capability info */
 231                            2 + /* AID */
 232                            2 + 8 + /* supported rates */
 233                            2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 234                            2 + sdata->u.mesh.mesh_id_len +
 235                            2 + sizeof(struct ieee80211_meshconf_ie) +
 236                            2 + sizeof(struct ieee80211_ht_cap) +
 237                            2 + sizeof(struct ieee80211_ht_operation) +
 238                            2 + 8 + /* peering IE */
 239                            sdata->u.mesh.ie_len);
 240        if (!skb)
 241                return -1;
 242        info = IEEE80211_SKB_CB(skb);
 243        skb_reserve(skb, local->tx_headroom);
 244        mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len);
 245        memset(mgmt, 0, hdr_len);
 246        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 247                                          IEEE80211_STYPE_ACTION);
 248        memcpy(mgmt->da, da, ETH_ALEN);
 249        memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 250        memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 251        mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 252        mgmt->u.action.u.self_prot.action_code = action;
 253
 254        if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 255                /* capability info */
 256                pos = skb_put(skb, 2);
 257                memset(pos, 0, 2);
 258                if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 259                        /* AID */
 260                        pos = skb_put(skb, 2);
 261                        memcpy(pos + 2, &plid, 2);
 262                }
 263                if (ieee80211_add_srates_ie(sdata, skb, true,
 264                                            local->oper_channel->band) ||
 265                    ieee80211_add_ext_srates_ie(sdata, skb, true,
 266                                                local->oper_channel->band) ||
 267                    mesh_add_rsn_ie(skb, sdata) ||
 268                    mesh_add_meshid_ie(skb, sdata) ||
 269                    mesh_add_meshconf_ie(skb, sdata))
 270                        goto free;
 271        } else {        /* WLAN_SP_MESH_PEERING_CLOSE */
 272                info->flags |= IEEE80211_TX_CTL_NO_ACK;
 273                if (mesh_add_meshid_ie(skb, sdata))
 274                        goto free;
 275        }
 276
 277        /* Add Mesh Peering Management element */
 278        switch (action) {
 279        case WLAN_SP_MESH_PEERING_OPEN:
 280                break;
 281        case WLAN_SP_MESH_PEERING_CONFIRM:
 282                ie_len += 2;
 283                include_plid = true;
 284                break;
 285        case WLAN_SP_MESH_PEERING_CLOSE:
 286                if (plid) {
 287                        ie_len += 2;
 288                        include_plid = true;
 289                }
 290                ie_len += 2;    /* reason code */
 291                break;
 292        default:
 293                err = -EINVAL;
 294                goto free;
 295        }
 296
 297        if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 298                goto free;
 299
 300        pos = skb_put(skb, 2 + ie_len);
 301        *pos++ = WLAN_EID_PEER_MGMT;
 302        *pos++ = ie_len;
 303        memcpy(pos, &peering_proto, 2);
 304        pos += 2;
 305        memcpy(pos, &llid, 2);
 306        pos += 2;
 307        if (include_plid) {
 308                memcpy(pos, &plid, 2);
 309                pos += 2;
 310        }
 311        if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 312                memcpy(pos, &reason, 2);
 313                pos += 2;
 314        }
 315
 316        if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 317                if (mesh_add_ht_cap_ie(skb, sdata) ||
 318                    mesh_add_ht_oper_ie(skb, sdata))
 319                        goto free;
 320        }
 321
 322        if (mesh_add_vendor_ies(skb, sdata))
 323                goto free;
 324
 325        ieee80211_tx_skb(sdata, skb);
 326        return 0;
 327free:
 328        kfree_skb(skb);
 329        return err;
 330}
 331
 332/**
 333 * mesh_peer_init - initialize new mesh peer and return resulting sta_info
 334 *
 335 * @sdata: local meshif
 336 * @addr: peer's address
 337 * @elems: IEs from beacon or mesh peering frame
 338 *
 339 * call under RCU
 340 */
 341static struct sta_info *mesh_peer_init(struct ieee80211_sub_if_data *sdata,
 342                                       u8 *addr,
 343                                       struct ieee802_11_elems *elems)
 344{
 345        struct ieee80211_local *local = sdata->local;
 346        enum ieee80211_band band = local->oper_channel->band;
 347        struct ieee80211_supported_band *sband;
 348        u32 rates, basic_rates = 0;
 349        struct sta_info *sta;
 350        bool insert = false;
 351
 352        sband = local->hw.wiphy->bands[band];
 353        rates = ieee80211_sta_get_rates(local, elems, band, &basic_rates);
 354
 355        sta = sta_info_get(sdata, addr);
 356        if (!sta) {
 357                /* Userspace handles peer allocation when security is enabled */
 358                if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
 359                        cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 360                                                           elems->ie_start,
 361                                                           elems->total_len,
 362                                                           GFP_ATOMIC);
 363                        return NULL;
 364                }
 365
 366                sta = mesh_plink_alloc(sdata, addr);
 367                if (!sta)
 368                        return NULL;
 369                insert = true;
 370        }
 371
 372        spin_lock_bh(&sta->lock);
 373        sta->last_rx = jiffies;
 374        if (sta->plink_state == NL80211_PLINK_ESTAB) {
 375                spin_unlock_bh(&sta->lock);
 376                return sta;
 377        }
 378
 379        sta->sta.supp_rates[band] = rates;
 380        if (elems->ht_cap_elem &&
 381            sdata->vif.bss_conf.channel_type != NL80211_CHAN_NO_HT)
 382                ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 383                                                  elems->ht_cap_elem,
 384                                                  &sta->sta.ht_cap);
 385        else
 386                memset(&sta->sta.ht_cap, 0, sizeof(sta->sta.ht_cap));
 387
 388        if (elems->ht_operation) {
 389                if (!(elems->ht_operation->ht_param &
 390                      IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
 391                        sta->sta.ht_cap.cap &=
 392                                            ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
 393                sta->ch_type =
 394                        ieee80211_ht_oper_to_channel_type(elems->ht_operation);
 395        }
 396
 397        rate_control_rate_init(sta);
 398        spin_unlock_bh(&sta->lock);
 399
 400        if (insert && sta_info_insert(sta))
 401                return NULL;
 402
 403        return sta;
 404}
 405
 406void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 407                           u8 *hw_addr,
 408                           struct ieee802_11_elems *elems)
 409{
 410        struct sta_info *sta;
 411
 412        rcu_read_lock();
 413        sta = mesh_peer_init(sdata, hw_addr, elems);
 414        if (!sta)
 415                goto out;
 416
 417        if (mesh_peer_accepts_plinks(elems) &&
 418            sta->plink_state == NL80211_PLINK_LISTEN &&
 419            sdata->u.mesh.accepting_plinks &&
 420            sdata->u.mesh.mshcfg.auto_open_plinks &&
 421            rssi_threshold_check(sta, sdata))
 422                mesh_plink_open(sta);
 423
 424out:
 425        rcu_read_unlock();
 426}
 427
 428static void mesh_plink_timer(unsigned long data)
 429{
 430        struct sta_info *sta;
 431        __le16 llid, plid, reason;
 432        struct ieee80211_sub_if_data *sdata;
 433
 434        /*
 435         * This STA is valid because sta_info_destroy() will
 436         * del_timer_sync() this timer after having made sure
 437         * it cannot be readded (by deleting the plink.)
 438         */
 439        sta = (struct sta_info *) data;
 440
 441        if (sta->sdata->local->quiescing) {
 442                sta->plink_timer_was_running = true;
 443                return;
 444        }
 445
 446        spin_lock_bh(&sta->lock);
 447        if (sta->ignore_plink_timer) {
 448                sta->ignore_plink_timer = false;
 449                spin_unlock_bh(&sta->lock);
 450                return;
 451        }
 452        mpl_dbg(sta->sdata,
 453                "Mesh plink timer for %pM fired on state %d\n",
 454                sta->sta.addr, sta->plink_state);
 455        reason = 0;
 456        llid = sta->llid;
 457        plid = sta->plid;
 458        sdata = sta->sdata;
 459
 460        switch (sta->plink_state) {
 461        case NL80211_PLINK_OPN_RCVD:
 462        case NL80211_PLINK_OPN_SNT:
 463                /* retry timer */
 464                if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
 465                        u32 rand;
 466                        mpl_dbg(sta->sdata,
 467                                "Mesh plink for %pM (retry, timeout): %d %d\n",
 468                                sta->sta.addr, sta->plink_retries,
 469                                sta->plink_timeout);
 470                        get_random_bytes(&rand, sizeof(u32));
 471                        sta->plink_timeout = sta->plink_timeout +
 472                                             rand % sta->plink_timeout;
 473                        ++sta->plink_retries;
 474                        mod_plink_timer(sta, sta->plink_timeout);
 475                        spin_unlock_bh(&sta->lock);
 476                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 477                                            sta->sta.addr, llid, 0, 0);
 478                        break;
 479                }
 480                reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES);
 481                /* fall through on else */
 482        case NL80211_PLINK_CNF_RCVD:
 483                /* confirm timer */
 484                if (!reason)
 485                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT);
 486                sta->plink_state = NL80211_PLINK_HOLDING;
 487                mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 488                spin_unlock_bh(&sta->lock);
 489                mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 490                                    sta->sta.addr, llid, plid, reason);
 491                break;
 492        case NL80211_PLINK_HOLDING:
 493                /* holding timer */
 494                del_timer(&sta->plink_timer);
 495                mesh_plink_fsm_restart(sta);
 496                spin_unlock_bh(&sta->lock);
 497                break;
 498        default:
 499                spin_unlock_bh(&sta->lock);
 500                break;
 501        }
 502}
 503
 504#ifdef CONFIG_PM
 505void mesh_plink_quiesce(struct sta_info *sta)
 506{
 507        if (del_timer_sync(&sta->plink_timer))
 508                sta->plink_timer_was_running = true;
 509}
 510
 511void mesh_plink_restart(struct sta_info *sta)
 512{
 513        if (sta->plink_timer_was_running) {
 514                add_timer(&sta->plink_timer);
 515                sta->plink_timer_was_running = false;
 516        }
 517}
 518#endif
 519
 520static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
 521{
 522        sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
 523        sta->plink_timer.data = (unsigned long) sta;
 524        sta->plink_timer.function = mesh_plink_timer;
 525        sta->plink_timeout = timeout;
 526        add_timer(&sta->plink_timer);
 527}
 528
 529int mesh_plink_open(struct sta_info *sta)
 530{
 531        __le16 llid;
 532        struct ieee80211_sub_if_data *sdata = sta->sdata;
 533
 534        if (!test_sta_flag(sta, WLAN_STA_AUTH))
 535                return -EPERM;
 536
 537        spin_lock_bh(&sta->lock);
 538        get_random_bytes(&llid, 2);
 539        sta->llid = llid;
 540        if (sta->plink_state != NL80211_PLINK_LISTEN &&
 541            sta->plink_state != NL80211_PLINK_BLOCKED) {
 542                spin_unlock_bh(&sta->lock);
 543                return -EBUSY;
 544        }
 545        sta->plink_state = NL80211_PLINK_OPN_SNT;
 546        mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 547        spin_unlock_bh(&sta->lock);
 548        mpl_dbg(sdata,
 549                "Mesh plink: starting establishment with %pM\n",
 550                sta->sta.addr);
 551
 552        return mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN,
 553                                   sta->sta.addr, llid, 0, 0);
 554}
 555
 556void mesh_plink_block(struct sta_info *sta)
 557{
 558        struct ieee80211_sub_if_data *sdata = sta->sdata;
 559        u32 changed;
 560
 561        spin_lock_bh(&sta->lock);
 562        changed = __mesh_plink_deactivate(sta);
 563        sta->plink_state = NL80211_PLINK_BLOCKED;
 564        spin_unlock_bh(&sta->lock);
 565
 566        ieee80211_bss_info_change_notify(sdata, changed);
 567}
 568
 569
 570void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
 571                         size_t len, struct ieee80211_rx_status *rx_status)
 572{
 573        struct ieee802_11_elems elems;
 574        struct sta_info *sta;
 575        enum plink_event event;
 576        enum ieee80211_self_protected_actioncode ftype;
 577        size_t baselen;
 578        bool matches_local = true;
 579        u8 ie_len;
 580        u8 *baseaddr;
 581        u32 changed = 0;
 582        __le16 plid, llid, reason;
 583        static const char *mplstates[] = {
 584                [NL80211_PLINK_LISTEN] = "LISTEN",
 585                [NL80211_PLINK_OPN_SNT] = "OPN-SNT",
 586                [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
 587                [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
 588                [NL80211_PLINK_ESTAB] = "ESTAB",
 589                [NL80211_PLINK_HOLDING] = "HOLDING",
 590                [NL80211_PLINK_BLOCKED] = "BLOCKED"
 591        };
 592
 593        /* need action_code, aux */
 594        if (len < IEEE80211_MIN_ACTION_SIZE + 3)
 595                return;
 596
 597        if (is_multicast_ether_addr(mgmt->da)) {
 598                mpl_dbg(sdata,
 599                        "Mesh plink: ignore frame from multicast address\n");
 600                return;
 601        }
 602
 603        baseaddr = mgmt->u.action.u.self_prot.variable;
 604        baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
 605        if (mgmt->u.action.u.self_prot.action_code ==
 606                                                WLAN_SP_MESH_PEERING_CONFIRM) {
 607                baseaddr += 4;
 608                baselen += 4;
 609        }
 610        ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
 611        if (!elems.peering) {
 612                mpl_dbg(sdata,
 613                        "Mesh plink: missing necessary peer link ie\n");
 614                return;
 615        }
 616        if (elems.rsn_len &&
 617                        sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
 618                mpl_dbg(sdata,
 619                        "Mesh plink: can't establish link with secure peer\n");
 620                return;
 621        }
 622
 623        ftype = mgmt->u.action.u.self_prot.action_code;
 624        ie_len = elems.peering_len;
 625        if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
 626            (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
 627            (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
 628                                                        && ie_len != 8)) {
 629                mpl_dbg(sdata,
 630                        "Mesh plink: incorrect plink ie length %d %d\n",
 631                        ftype, ie_len);
 632                return;
 633        }
 634
 635        if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 636                                (!elems.mesh_id || !elems.mesh_config)) {
 637                mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
 638                return;
 639        }
 640        /* Note the lines below are correct, the llid in the frame is the plid
 641         * from the point of view of this host.
 642         */
 643        memcpy(&plid, PLINK_GET_LLID(elems.peering), 2);
 644        if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
 645            (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
 646                memcpy(&llid, PLINK_GET_PLID(elems.peering), 2);
 647
 648        rcu_read_lock();
 649
 650        sta = sta_info_get(sdata, mgmt->sa);
 651        if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) {
 652                mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
 653                rcu_read_unlock();
 654                return;
 655        }
 656
 657        if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
 658            !rssi_threshold_check(sta, sdata)) {
 659                mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
 660                        mgmt->sa);
 661                rcu_read_unlock();
 662                return;
 663        }
 664
 665        if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) {
 666                mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
 667                rcu_read_unlock();
 668                return;
 669        }
 670
 671        if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
 672                rcu_read_unlock();
 673                return;
 674        }
 675
 676        /* Now we will figure out the appropriate event... */
 677        event = PLINK_UNDEFINED;
 678        if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
 679            !mesh_matches_local(sdata, &elems)) {
 680                matches_local = false;
 681                switch (ftype) {
 682                case WLAN_SP_MESH_PEERING_OPEN:
 683                        event = OPN_RJCT;
 684                        break;
 685                case WLAN_SP_MESH_PEERING_CONFIRM:
 686                        event = CNF_RJCT;
 687                        break;
 688                default:
 689                        break;
 690                }
 691        }
 692
 693        if (!sta && !matches_local) {
 694                rcu_read_unlock();
 695                reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 696                llid = 0;
 697                mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 698                                    mgmt->sa, llid, plid, reason);
 699                return;
 700        } else if (!sta) {
 701                /* ftype == WLAN_SP_MESH_PEERING_OPEN */
 702                if (!mesh_plink_free_count(sdata)) {
 703                        mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
 704                        rcu_read_unlock();
 705                        return;
 706                }
 707                event = OPN_ACPT;
 708        } else if (matches_local) {
 709                switch (ftype) {
 710                case WLAN_SP_MESH_PEERING_OPEN:
 711                        if (!mesh_plink_free_count(sdata) ||
 712                            (sta->plid && sta->plid != plid))
 713                                event = OPN_IGNR;
 714                        else
 715                                event = OPN_ACPT;
 716                        break;
 717                case WLAN_SP_MESH_PEERING_CONFIRM:
 718                        if (!mesh_plink_free_count(sdata) ||
 719                            (sta->llid != llid || sta->plid != plid))
 720                                event = CNF_IGNR;
 721                        else
 722                                event = CNF_ACPT;
 723                        break;
 724                case WLAN_SP_MESH_PEERING_CLOSE:
 725                        if (sta->plink_state == NL80211_PLINK_ESTAB)
 726                                /* Do not check for llid or plid. This does not
 727                                 * follow the standard but since multiple plinks
 728                                 * per sta are not supported, it is necessary in
 729                                 * order to avoid a livelock when MP A sees an
 730                                 * establish peer link to MP B but MP B does not
 731                                 * see it. This can be caused by a timeout in
 732                                 * B's peer link establishment or B beign
 733                                 * restarted.
 734                                 */
 735                                event = CLS_ACPT;
 736                        else if (sta->plid != plid)
 737                                event = CLS_IGNR;
 738                        else if (ie_len == 7 && sta->llid != llid)
 739                                event = CLS_IGNR;
 740                        else
 741                                event = CLS_ACPT;
 742                        break;
 743                default:
 744                        mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
 745                        rcu_read_unlock();
 746                        return;
 747                }
 748        }
 749
 750        if (event == OPN_ACPT) {
 751                /* allocate sta entry if necessary and update info */
 752                sta = mesh_peer_init(sdata, mgmt->sa, &elems);
 753                if (!sta) {
 754                        mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
 755                        rcu_read_unlock();
 756                        return;
 757                }
 758        }
 759
 760        mpl_dbg(sdata,
 761                "Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
 762                mgmt->sa, mplstates[sta->plink_state],
 763                le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
 764                event);
 765        reason = 0;
 766        spin_lock_bh(&sta->lock);
 767        switch (sta->plink_state) {
 768                /* spin_unlock as soon as state is updated at each case */
 769        case NL80211_PLINK_LISTEN:
 770                switch (event) {
 771                case CLS_ACPT:
 772                        mesh_plink_fsm_restart(sta);
 773                        spin_unlock_bh(&sta->lock);
 774                        break;
 775                case OPN_ACPT:
 776                        sta->plink_state = NL80211_PLINK_OPN_RCVD;
 777                        sta->plid = plid;
 778                        get_random_bytes(&llid, 2);
 779                        sta->llid = llid;
 780                        mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
 781                        spin_unlock_bh(&sta->lock);
 782                        mesh_plink_frame_tx(sdata,
 783                                            WLAN_SP_MESH_PEERING_OPEN,
 784                                            sta->sta.addr, llid, 0, 0);
 785                        mesh_plink_frame_tx(sdata,
 786                                            WLAN_SP_MESH_PEERING_CONFIRM,
 787                                            sta->sta.addr, llid, plid, 0);
 788                        break;
 789                default:
 790                        spin_unlock_bh(&sta->lock);
 791                        break;
 792                }
 793                break;
 794
 795        case NL80211_PLINK_OPN_SNT:
 796                switch (event) {
 797                case OPN_RJCT:
 798                case CNF_RJCT:
 799                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 800                case CLS_ACPT:
 801                        if (!reason)
 802                                reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 803                        sta->reason = reason;
 804                        sta->plink_state = NL80211_PLINK_HOLDING;
 805                        if (!mod_plink_timer(sta,
 806                                             dot11MeshHoldingTimeout(sdata)))
 807                                sta->ignore_plink_timer = true;
 808
 809                        llid = sta->llid;
 810                        spin_unlock_bh(&sta->lock);
 811                        mesh_plink_frame_tx(sdata,
 812                                            WLAN_SP_MESH_PEERING_CLOSE,
 813                                            sta->sta.addr, llid, plid, reason);
 814                        break;
 815                case OPN_ACPT:
 816                        /* retry timer is left untouched */
 817                        sta->plink_state = NL80211_PLINK_OPN_RCVD;
 818                        sta->plid = plid;
 819                        llid = sta->llid;
 820                        spin_unlock_bh(&sta->lock);
 821                        mesh_plink_frame_tx(sdata,
 822                                            WLAN_SP_MESH_PEERING_CONFIRM,
 823                                            sta->sta.addr, llid, plid, 0);
 824                        break;
 825                case CNF_ACPT:
 826                        sta->plink_state = NL80211_PLINK_CNF_RCVD;
 827                        if (!mod_plink_timer(sta,
 828                                             dot11MeshConfirmTimeout(sdata)))
 829                                sta->ignore_plink_timer = true;
 830
 831                        spin_unlock_bh(&sta->lock);
 832                        break;
 833                default:
 834                        spin_unlock_bh(&sta->lock);
 835                        break;
 836                }
 837                break;
 838
 839        case NL80211_PLINK_OPN_RCVD:
 840                switch (event) {
 841                case OPN_RJCT:
 842                case CNF_RJCT:
 843                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 844                case CLS_ACPT:
 845                        if (!reason)
 846                                reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 847                        sta->reason = reason;
 848                        sta->plink_state = NL80211_PLINK_HOLDING;
 849                        if (!mod_plink_timer(sta,
 850                                             dot11MeshHoldingTimeout(sdata)))
 851                                sta->ignore_plink_timer = true;
 852
 853                        llid = sta->llid;
 854                        spin_unlock_bh(&sta->lock);
 855                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 856                                            sta->sta.addr, llid, plid, reason);
 857                        break;
 858                case OPN_ACPT:
 859                        llid = sta->llid;
 860                        spin_unlock_bh(&sta->lock);
 861                        mesh_plink_frame_tx(sdata,
 862                                            WLAN_SP_MESH_PEERING_CONFIRM,
 863                                            sta->sta.addr, llid, plid, 0);
 864                        break;
 865                case CNF_ACPT:
 866                        del_timer(&sta->plink_timer);
 867                        sta->plink_state = NL80211_PLINK_ESTAB;
 868                        spin_unlock_bh(&sta->lock);
 869                        changed |= mesh_plink_inc_estab_count(sdata);
 870                        changed |= mesh_set_ht_prot_mode(sdata);
 871                        mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 872                                sta->sta.addr);
 873                        break;
 874                default:
 875                        spin_unlock_bh(&sta->lock);
 876                        break;
 877                }
 878                break;
 879
 880        case NL80211_PLINK_CNF_RCVD:
 881                switch (event) {
 882                case OPN_RJCT:
 883                case CNF_RJCT:
 884                        reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG);
 885                case CLS_ACPT:
 886                        if (!reason)
 887                                reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 888                        sta->reason = reason;
 889                        sta->plink_state = NL80211_PLINK_HOLDING;
 890                        if (!mod_plink_timer(sta,
 891                                             dot11MeshHoldingTimeout(sdata)))
 892                                sta->ignore_plink_timer = true;
 893
 894                        llid = sta->llid;
 895                        spin_unlock_bh(&sta->lock);
 896                        mesh_plink_frame_tx(sdata,
 897                                            WLAN_SP_MESH_PEERING_CLOSE,
 898                                            sta->sta.addr, llid, plid, reason);
 899                        break;
 900                case OPN_ACPT:
 901                        del_timer(&sta->plink_timer);
 902                        sta->plink_state = NL80211_PLINK_ESTAB;
 903                        spin_unlock_bh(&sta->lock);
 904                        changed |= mesh_plink_inc_estab_count(sdata);
 905                        changed |= mesh_set_ht_prot_mode(sdata);
 906                        mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n",
 907                                sta->sta.addr);
 908                        mesh_plink_frame_tx(sdata,
 909                                            WLAN_SP_MESH_PEERING_CONFIRM,
 910                                            sta->sta.addr, llid, plid, 0);
 911                        break;
 912                default:
 913                        spin_unlock_bh(&sta->lock);
 914                        break;
 915                }
 916                break;
 917
 918        case NL80211_PLINK_ESTAB:
 919                switch (event) {
 920                case CLS_ACPT:
 921                        reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE);
 922                        sta->reason = reason;
 923                        changed |= __mesh_plink_deactivate(sta);
 924                        sta->plink_state = NL80211_PLINK_HOLDING;
 925                        llid = sta->llid;
 926                        mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
 927                        spin_unlock_bh(&sta->lock);
 928                        changed |= mesh_set_ht_prot_mode(sdata);
 929                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 930                                            sta->sta.addr, llid, plid, reason);
 931                        break;
 932                case OPN_ACPT:
 933                        llid = sta->llid;
 934                        spin_unlock_bh(&sta->lock);
 935                        mesh_plink_frame_tx(sdata,
 936                                            WLAN_SP_MESH_PEERING_CONFIRM,
 937                                            sta->sta.addr, llid, plid, 0);
 938                        break;
 939                default:
 940                        spin_unlock_bh(&sta->lock);
 941                        break;
 942                }
 943                break;
 944        case NL80211_PLINK_HOLDING:
 945                switch (event) {
 946                case CLS_ACPT:
 947                        if (del_timer(&sta->plink_timer))
 948                                sta->ignore_plink_timer = 1;
 949                        mesh_plink_fsm_restart(sta);
 950                        spin_unlock_bh(&sta->lock);
 951                        break;
 952                case OPN_ACPT:
 953                case CNF_ACPT:
 954                case OPN_RJCT:
 955                case CNF_RJCT:
 956                        llid = sta->llid;
 957                        reason = sta->reason;
 958                        spin_unlock_bh(&sta->lock);
 959                        mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE,
 960                                            sta->sta.addr, llid, plid, reason);
 961                        break;
 962                default:
 963                        spin_unlock_bh(&sta->lock);
 964                }
 965                break;
 966        default:
 967                /* should not get here, PLINK_BLOCKED is dealt with at the
 968                 * beginning of the function
 969                 */
 970                spin_unlock_bh(&sta->lock);
 971                break;
 972        }
 973
 974        rcu_read_unlock();
 975
 976        if (changed)
 977                ieee80211_bss_info_change_notify(sdata, changed);
 978}
 979
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