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v5.9
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2008, 2009 open80211s Ltd.
   4 * Copyright (C) 2019 Intel Corporation
   5 * Author:     Luis Carlos Cobo <luisca@cozybit.com>
 
 
 
 
   6 */
   7#include <linux/gfp.h>
   8#include <linux/kernel.h>
   9#include <linux/random.h>
  10#include <linux/rculist.h>
  11
  12#include "ieee80211_i.h"
  13#include "rate.h"
  14#include "mesh.h"
  15
  16#define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2)
  17#define PLINK_GET_LLID(p) (p + 2)
  18#define PLINK_GET_PLID(p) (p + 4)
  19
  20#define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \
  21				jiffies + msecs_to_jiffies(t)))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  22
  23enum plink_event {
  24	PLINK_UNDEFINED,
  25	OPN_ACPT,
  26	OPN_RJCT,
  27	OPN_IGNR,
  28	CNF_ACPT,
  29	CNF_RJCT,
  30	CNF_IGNR,
  31	CLS_ACPT,
  32	CLS_IGNR
  33};
  34
  35static const char * const mplstates[] = {
  36	[NL80211_PLINK_LISTEN] = "LISTEN",
  37	[NL80211_PLINK_OPN_SNT] = "OPN-SNT",
  38	[NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
  39	[NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
  40	[NL80211_PLINK_ESTAB] = "ESTAB",
  41	[NL80211_PLINK_HOLDING] = "HOLDING",
  42	[NL80211_PLINK_BLOCKED] = "BLOCKED"
  43};
  44
  45static const char * const mplevents[] = {
  46	[PLINK_UNDEFINED] = "NONE",
  47	[OPN_ACPT] = "OPN_ACPT",
  48	[OPN_RJCT] = "OPN_RJCT",
  49	[OPN_IGNR] = "OPN_IGNR",
  50	[CNF_ACPT] = "CNF_ACPT",
  51	[CNF_RJCT] = "CNF_RJCT",
  52	[CNF_IGNR] = "CNF_IGNR",
  53	[CLS_ACPT] = "CLS_ACPT",
  54	[CLS_IGNR] = "CLS_IGNR"
  55};
  56
  57/* We only need a valid sta if user configured a minimum rssi_threshold. */
  58static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata,
  59				 struct sta_info *sta)
  60{
  61	s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold;
  62	return rssi_threshold == 0 ||
  63	       (sta &&
  64		(s8)-ewma_signal_read(&sta->rx_stats_avg.signal) >
  65						rssi_threshold);
  66}
  67
  68/**
  69 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
  70 *
  71 * @sta: mesh peer link to restart
  72 *
  73 * Locking: this function must be called holding sta->mesh->plink_lock
  74 */
  75static inline void mesh_plink_fsm_restart(struct sta_info *sta)
  76{
  77	lockdep_assert_held(&sta->mesh->plink_lock);
  78	sta->mesh->plink_state = NL80211_PLINK_LISTEN;
  79	sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0;
  80	sta->mesh->plink_retries = 0;
  81}
  82
  83/*
  84 * mesh_set_short_slot_time - enable / disable ERP short slot time.
  85 *
  86 * The standard indirectly mandates mesh STAs to turn off short slot time by
  87 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we
  88 * can't be sneaky about it. Enable short slot time if all mesh STAs in the
  89 * MBSS support ERP rates.
  90 *
  91 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change.
  92 */
  93static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata)
 
  94{
  95	struct ieee80211_local *local = sdata->local;
  96	struct ieee80211_supported_band *sband;
  97	struct sta_info *sta;
  98	u32 erp_rates = 0, changed = 0;
  99	int i;
 100	bool short_slot = false;
 101
 102	sband = ieee80211_get_sband(sdata);
 103	if (!sband)
 104		return changed;
 105
 106	if (sband->band == NL80211_BAND_5GHZ) {
 107		/* (IEEE 802.11-2012 19.4.5) */
 108		short_slot = true;
 109		goto out;
 110	} else if (sband->band != NL80211_BAND_2GHZ) {
 111		goto out;
 112	}
 113
 114	for (i = 0; i < sband->n_bitrates; i++)
 115		if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)
 116			erp_rates |= BIT(i);
 117
 118	if (!erp_rates)
 119		goto out;
 120
 121	rcu_read_lock();
 122	list_for_each_entry_rcu(sta, &local->sta_list, list) {
 123		if (sdata != sta->sdata ||
 124		    sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 125			continue;
 126
 127		short_slot = false;
 128		if (erp_rates & sta->sta.supp_rates[sband->band])
 129			short_slot = true;
 130		 else
 131			break;
 132	}
 133	rcu_read_unlock();
 134
 135out:
 136	if (sdata->vif.bss_conf.use_short_slot != short_slot) {
 137		sdata->vif.bss_conf.use_short_slot = short_slot;
 138		changed = BSS_CHANGED_ERP_SLOT;
 139		mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n",
 140			sdata->vif.addr, short_slot);
 141	}
 142	return changed;
 143}
 144
 145/**
 146 * mesh_set_ht_prot_mode - set correct HT protection mode
 147 *
 148 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT
 149 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT
 150 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is
 151 * selected if any non-HT peers are present in our MBSS.  20MHz-protection mode
 152 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one
 153 * HT20 peer is present. Otherwise no-protection mode is selected.
 154 */
 155static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata)
 156{
 157	struct ieee80211_local *local = sdata->local;
 158	struct sta_info *sta;
 159	u16 ht_opmode;
 160	bool non_ht_sta = false, ht20_sta = false;
 161
 162	switch (sdata->vif.bss_conf.chandef.width) {
 163	case NL80211_CHAN_WIDTH_20_NOHT:
 164	case NL80211_CHAN_WIDTH_5:
 165	case NL80211_CHAN_WIDTH_10:
 166		return 0;
 167	default:
 168		break;
 169	}
 
 
 170
 171	rcu_read_lock();
 172	list_for_each_entry_rcu(sta, &local->sta_list, list) {
 173		if (sdata != sta->sdata ||
 174		    sta->mesh->plink_state != NL80211_PLINK_ESTAB)
 175			continue;
 176
 177		if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20)
 178			continue;
 179
 180		if (!sta->sta.ht_cap.ht_supported) {
 181			mpl_dbg(sdata, "nonHT sta (%pM) is present\n",
 182				       sta->sta.addr);
 183			non_ht_sta = true;
 184			break;
 185		}
 186
 187		mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr);
 188		ht20_sta = true;
 189	}
 190	rcu_read_unlock();
 
 
 
 
 
 
 
 191
 192	if (non_ht_sta)
 193		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED;
 194	else if (ht20_sta &&
 195		 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20)
 196		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ;
 197	else
 198		ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE;
 199
 200	if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode)
 201		return 0;
 202
 203	sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
 204	sdata->u.mesh.mshcfg.ht_opmode = ht_opmode;
 205	mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode);
 206	return BSS_CHANGED_HT;
 207}
 208
 209static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
 210			       struct sta_info *sta,
 211			       enum ieee80211_self_protected_actioncode action,
 212			       u8 *da, u16 llid, u16 plid, u16 reason)
 213{
 214	struct ieee80211_local *local = sdata->local;
 215	struct sk_buff *skb;
 216	struct ieee80211_tx_info *info;
 217	struct ieee80211_mgmt *mgmt;
 218	bool include_plid = false;
 219	u16 peering_proto = 0;
 220	u8 *pos, ie_len = 4;
 221	u8 ie_len_he_cap;
 222	int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot);
 223	int err = -ENOMEM;
 224
 225	ie_len_he_cap = ieee80211_ie_len_he_cap(sdata,
 226						NL80211_IFTYPE_MESH_POINT);
 227	skb = dev_alloc_skb(local->tx_headroom +
 228			    hdr_len +
 229			    2 + /* capability info */
 230			    2 + /* AID */
 231			    2 + 8 + /* supported rates */
 232			    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
 233			    2 + sdata->u.mesh.mesh_id_len +
 234			    2 + sizeof(struct ieee80211_meshconf_ie) +
 235			    2 + sizeof(struct ieee80211_ht_cap) +
 236			    2 + sizeof(struct ieee80211_ht_operation) +
 237			    2 + sizeof(struct ieee80211_vht_cap) +
 238			    2 + sizeof(struct ieee80211_vht_operation) +
 239			    ie_len_he_cap +
 240			    2 + 1 + sizeof(struct ieee80211_he_operation) +
 241				    sizeof(struct ieee80211_he_6ghz_oper) +
 242			    2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) +
 243			    2 + 8 + /* peering IE */
 244			    sdata->u.mesh.ie_len);
 245	if (!skb)
 246		return err;
 247	info = IEEE80211_SKB_CB(skb);
 248	skb_reserve(skb, local->tx_headroom);
 249	mgmt = skb_put_zero(skb, hdr_len);
 
 
 
 
 250	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 251					  IEEE80211_STYPE_ACTION);
 252	memcpy(mgmt->da, da, ETH_ALEN);
 253	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 254	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
 255	mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED;
 256	mgmt->u.action.u.self_prot.action_code = action;
 257
 258	if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 259		struct ieee80211_supported_band *sband;
 260		enum nl80211_band band;
 261
 262		sband = ieee80211_get_sband(sdata);
 263		if (!sband) {
 264			err = -EINVAL;
 265			goto free;
 266		}
 267		band = sband->band;
 268
 269		/* capability info */
 270		pos = skb_put_zero(skb, 2);
 271		if (action == WLAN_SP_MESH_PEERING_CONFIRM) {
 272			/* AID */
 273			pos = skb_put(skb, 2);
 274			put_unaligned_le16(sta->sta.aid, pos);
 
 
 
 275		}
 276		if (ieee80211_add_srates_ie(sdata, skb, true, band) ||
 277		    ieee80211_add_ext_srates_ie(sdata, skb, true, band) ||
 278		    mesh_add_rsn_ie(sdata, skb) ||
 279		    mesh_add_meshid_ie(sdata, skb) ||
 280		    mesh_add_meshconf_ie(sdata, skb))
 281			goto free;
 282	} else {	/* WLAN_SP_MESH_PEERING_CLOSE */
 283		info->flags |= IEEE80211_TX_CTL_NO_ACK;
 284		if (mesh_add_meshid_ie(sdata, skb))
 285			goto free;
 286	}
 287
 288	/* Add Mesh Peering Management element */
 289	switch (action) {
 290	case WLAN_SP_MESH_PEERING_OPEN:
 
 291		break;
 292	case WLAN_SP_MESH_PEERING_CONFIRM:
 293		ie_len += 2;
 294		include_plid = true;
 295		break;
 296	case WLAN_SP_MESH_PEERING_CLOSE:
 297		if (plid) {
 298			ie_len += 2;
 
 
 
 299			include_plid = true;
 300		}
 301		ie_len += 2;	/* reason code */
 302		break;
 303	default:
 304		err = -EINVAL;
 305		goto free;
 306	}
 307
 308	if (WARN_ON(skb_tailroom(skb) < 2 + ie_len))
 309		goto free;
 310
 311	pos = skb_put(skb, 2 + ie_len);
 312	*pos++ = WLAN_EID_PEER_MGMT;
 313	*pos++ = ie_len;
 314	memcpy(pos, &peering_proto, 2);
 315	pos += 2;
 316	put_unaligned_le16(llid, pos);
 317	pos += 2;
 318	if (include_plid) {
 319		put_unaligned_le16(plid, pos);
 320		pos += 2;
 
 321	}
 322	if (action == WLAN_SP_MESH_PEERING_CLOSE) {
 323		put_unaligned_le16(reason, pos);
 324		pos += 2;
 
 325	}
 326
 327	if (action != WLAN_SP_MESH_PEERING_CLOSE) {
 328		if (mesh_add_ht_cap_ie(sdata, skb) ||
 329		    mesh_add_ht_oper_ie(sdata, skb) ||
 330		    mesh_add_vht_cap_ie(sdata, skb) ||
 331		    mesh_add_vht_oper_ie(sdata, skb) ||
 332		    mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) ||
 333		    mesh_add_he_oper_ie(sdata, skb) ||
 334		    mesh_add_he_6ghz_cap_ie(sdata, skb))
 335			goto free;
 336	}
 337
 338	if (mesh_add_vendor_ies(sdata, skb))
 339		goto free;
 340
 341	ieee80211_tx_skb(sdata, skb);
 342	return 0;
 343free:
 344	kfree_skb(skb);
 345	return err;
 346}
 347
 348/**
 349 * __mesh_plink_deactivate - deactivate mesh peer link
 350 *
 351 * @sta: mesh peer link to deactivate
 352 *
 353 * Mesh paths with this peer as next hop should be flushed
 354 * by the caller outside of plink_lock.
 355 *
 356 * Returns beacon changed flag if the beacon content changed.
 357 *
 358 * Locking: the caller must hold sta->mesh->plink_lock
 359 */
 360static u32 __mesh_plink_deactivate(struct sta_info *sta)
 361{
 362	struct ieee80211_sub_if_data *sdata = sta->sdata;
 363	u32 changed = 0;
 364
 365	lockdep_assert_held(&sta->mesh->plink_lock);
 366
 367	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
 368		changed = mesh_plink_dec_estab_count(sdata);
 369	sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 370
 371	ieee80211_mps_sta_status_update(sta);
 372	changed |= ieee80211_mps_set_sta_local_pm(sta,
 373			NL80211_MESH_POWER_UNKNOWN);
 374
 375	return changed;
 376}
 377
 378/**
 379 * mesh_plink_deactivate - deactivate mesh peer link
 380 *
 381 * @sta: mesh peer link to deactivate
 382 *
 383 * All mesh paths with this peer as next hop will be flushed
 384 */
 385u32 mesh_plink_deactivate(struct sta_info *sta)
 386{
 387	struct ieee80211_sub_if_data *sdata = sta->sdata;
 388	u32 changed;
 389
 390	spin_lock_bh(&sta->mesh->plink_lock);
 391	changed = __mesh_plink_deactivate(sta);
 392
 393	if (!sdata->u.mesh.user_mpm) {
 394		sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED;
 395		mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE,
 396				    sta->sta.addr, sta->mesh->llid,
 397				    sta->mesh->plid, sta->mesh->reason);
 398	}
 399	spin_unlock_bh(&sta->mesh->plink_lock);
 400	if (!sdata->u.mesh.user_mpm)
 401		del_timer_sync(&sta->mesh->plink_timer);
 402	mesh_path_flush_by_nexthop(sta);
 403
 404	/* make sure no readers can access nexthop sta from here on */
 405	synchronize_net();
 406
 407	return changed;
 408}
 409
 410static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 411			       struct sta_info *sta,
 412			       struct ieee802_11_elems *elems)
 413{
 414	struct ieee80211_local *local = sdata->local;
 415	struct ieee80211_supported_band *sband;
 416	u32 rates, basic_rates = 0, changed = 0;
 417	enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
 418
 419	sband = ieee80211_get_sband(sdata);
 420	if (!sband)
 421		return;
 422
 423	rates = ieee80211_sta_get_rates(sdata, elems, sband->band,
 424					&basic_rates);
 425
 426	spin_lock_bh(&sta->mesh->plink_lock);
 427	sta->rx_stats.last_rx = jiffies;
 428
 429	/* rates and capabilities don't change during peering */
 430	if (sta->mesh->plink_state == NL80211_PLINK_ESTAB &&
 431	    sta->mesh->processed_beacon)
 432		goto out;
 433	sta->mesh->processed_beacon = true;
 434
 435	if (sta->sta.supp_rates[sband->band] != rates)
 436		changed |= IEEE80211_RC_SUPP_RATES_CHANGED;
 437	sta->sta.supp_rates[sband->band] = rates;
 438
 439	if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
 440					      elems->ht_cap_elem, sta))
 441		changed |= IEEE80211_RC_BW_CHANGED;
 442
 443	ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
 444					    elems->vht_cap_elem, sta);
 445
 446	ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap,
 447					  elems->he_cap_len,
 448					  elems->he_6ghz_capa,
 449					  sta);
 450
 451	if (bw != sta->sta.bandwidth)
 452		changed |= IEEE80211_RC_BW_CHANGED;
 453
 454	/* HT peer is operating 20MHz-only */
 455	if (elems->ht_operation &&
 456	    !(elems->ht_operation->ht_param &
 457	      IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
 458		if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20)
 459			changed |= IEEE80211_RC_BW_CHANGED;
 460		sta->sta.bandwidth = IEEE80211_STA_RX_BW_20;
 461	}
 462
 463	if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
 464		rate_control_rate_init(sta);
 465	else
 466		rate_control_rate_update(local, sband, sta, changed);
 467out:
 468	spin_unlock_bh(&sta->mesh->plink_lock);
 469}
 470
 471static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata)
 472{
 473	struct sta_info *sta;
 474	unsigned long *aid_map;
 475	int aid;
 476
 477	aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1),
 478			  sizeof(*aid_map), GFP_KERNEL);
 479	if (!aid_map)
 480		return -ENOMEM;
 481
 482	/* reserve aid 0 for mcast indication */
 483	__set_bit(0, aid_map);
 484
 485	rcu_read_lock();
 486	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list)
 487		__set_bit(sta->sta.aid, aid_map);
 488	rcu_read_unlock();
 489
 490	aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1);
 491	kfree(aid_map);
 492
 493	if (aid > IEEE80211_MAX_AID)
 494		return -ENOBUFS;
 495
 496	return aid;
 497}
 498
 499static struct sta_info *
 500__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)
 501{
 502	struct sta_info *sta;
 503	int aid;
 504
 505	if (sdata->local->num_sta >= MESH_MAX_PLINKS)
 506		return NULL;
 507
 508	aid = mesh_allocate_aid(sdata);
 509	if (aid < 0)
 510		return NULL;
 511
 512	sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
 513	if (!sta)
 514		return NULL;
 515
 516	sta->mesh->plink_state = NL80211_PLINK_LISTEN;
 517	sta->sta.wme = true;
 518	sta->sta.aid = aid;
 519
 520	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
 521	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
 522	sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 523
 524	return sta;
 525}
 526
 527static struct sta_info *
 528mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr,
 529		    struct ieee802_11_elems *elems,
 530		    struct ieee80211_rx_status *rx_status)
 531{
 532	struct sta_info *sta = NULL;
 533
 534	/* Userspace handles station allocation */
 535	if (sdata->u.mesh.user_mpm ||
 536	    sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) {
 537		if (mesh_peer_accepts_plinks(elems) &&
 538		    mesh_plink_availables(sdata)) {
 539			int sig = 0;
 540
 541			if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM))
 542				sig = rx_status->signal;
 543
 544			cfg80211_notify_new_peer_candidate(sdata->dev, addr,
 545							   elems->ie_start,
 546							   elems->total_len,
 547							   sig, GFP_KERNEL);
 548		}
 549	} else
 550		sta = __mesh_sta_info_alloc(sdata, addr);
 551
 552	return sta;
 553}
 554
 555/*
 556 * mesh_sta_info_get - return mesh sta info entry for @addr.
 557 *
 558 * @sdata: local meshif
 559 * @addr: peer's address
 560 * @elems: IEs from beacon or mesh peering frame.
 561 * @rx_status: rx status for the frame for signal reporting
 562 *
 563 * Return existing or newly allocated sta_info under RCU read lock.
 564 * (re)initialize with given IEs.
 565 */
 566static struct sta_info *
 567mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
 568		  u8 *addr, struct ieee802_11_elems *elems,
 569		  struct ieee80211_rx_status *rx_status) __acquires(RCU)
 570{
 571	struct sta_info *sta = NULL;
 572
 573	rcu_read_lock();
 574	sta = sta_info_get(sdata, addr);
 575	if (sta) {
 576		mesh_sta_info_init(sdata, sta, elems);
 577	} else {
 578		rcu_read_unlock();
 579		/* can't run atomic */
 580		sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status);
 581		if (!sta) {
 582			rcu_read_lock();
 583			return NULL;
 
 
 
 
 
 
 
 
 584		}
 585
 586		mesh_sta_info_init(sdata, sta, elems);
 587
 588		if (sta_info_insert_rcu(sta))
 589			return NULL;
 590	}
 591
 592	return sta;
 593}
 594
 595/*
 596 * mesh_neighbour_update - update or initialize new mesh neighbor.
 597 *
 598 * @sdata: local meshif
 599 * @addr: peer's address
 600 * @elems: IEs from beacon or mesh peering frame
 601 * @rx_status: rx status for the frame for signal reporting
 602 *
 603 * Initiates peering if appropriate.
 604 */
 605void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 606			   u8 *hw_addr,
 607			   struct ieee802_11_elems *elems,
 608			   struct ieee80211_rx_status *rx_status)
 609{
 610	struct sta_info *sta;
 611	u32 changed = 0;
 612
 613	sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status);
 614	if (!sta)
 615		goto out;
 616
 617	sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form &
 618		IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE;
 619
 620	if (mesh_peer_accepts_plinks(elems) &&
 621	    sta->mesh->plink_state == NL80211_PLINK_LISTEN &&
 622	    sdata->u.mesh.accepting_plinks &&
 623	    sdata->u.mesh.mshcfg.auto_open_plinks &&
 624	    rssi_threshold_check(sdata, sta))
 625		changed = mesh_plink_open(sta);
 626
 627	ieee80211_mps_frame_release(sta, elems);
 628out:
 629	rcu_read_unlock();
 630	ieee80211_mbss_info_change_notify(sdata, changed);
 631}
 632
 633void mesh_plink_timer(struct timer_list *t)
 634{
 635	struct mesh_sta *mesh = from_timer(mesh, t, plink_timer);
 636	struct sta_info *sta;
 637	u16 reason = 0;
 638	struct ieee80211_sub_if_data *sdata;
 639	struct mesh_config *mshcfg;
 640	enum ieee80211_self_protected_actioncode action = 0;
 641
 642	/*
 643	 * This STA is valid because sta_info_destroy() will
 644	 * del_timer_sync() this timer after having made sure
 645	 * it cannot be readded (by deleting the plink.)
 646	 */
 647	sta = mesh->plink_sta;
 648
 649	if (sta->sdata->local->quiescing)
 650		return;
 651
 652	spin_lock_bh(&sta->mesh->plink_lock);
 653
 654	/* If a timer fires just before a state transition on another CPU,
 655	 * we may have already extended the timeout and changed state by the
 656	 * time we've acquired the lock and arrived  here.  In that case,
 657	 * skip this timer and wait for the new one.
 658	 */
 659	if (time_before(jiffies, sta->mesh->plink_timer.expires)) {
 660		mpl_dbg(sta->sdata,
 661			"Ignoring timer for %pM in state %s (timer adjusted)",
 662			sta->sta.addr, mplstates[sta->mesh->plink_state]);
 663		spin_unlock_bh(&sta->mesh->plink_lock);
 664		return;
 665	}
 666
 667	/* del_timer() and handler may race when entering these states */
 668	if (sta->mesh->plink_state == NL80211_PLINK_LISTEN ||
 669	    sta->mesh->plink_state == NL80211_PLINK_ESTAB) {
 670		mpl_dbg(sta->sdata,
 671			"Ignoring timer for %pM in state %s (timer deleted)",
 672			sta->sta.addr, mplstates[sta->mesh->plink_state]);
 673		spin_unlock_bh(&sta->mesh->plink_lock);
 674		return;
 675	}
 676
 677	mpl_dbg(sta->sdata,
 678		"Mesh plink timer for %pM fired on state %s\n",
 679		sta->sta.addr, mplstates[sta->mesh->plink_state]);
 
 680	sdata = sta->sdata;
 681	mshcfg = &sdata->u.mesh.mshcfg;
 682
 683	switch (sta->mesh->plink_state) {
 684	case NL80211_PLINK_OPN_RCVD:
 685	case NL80211_PLINK_OPN_SNT:
 686		/* retry timer */
 687		if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) {
 688			u32 rand;
 689			mpl_dbg(sta->sdata,
 690				"Mesh plink for %pM (retry, timeout): %d %d\n",
 691				sta->sta.addr, sta->mesh->plink_retries,
 692				sta->mesh->plink_timeout);
 693			get_random_bytes(&rand, sizeof(u32));
 694			sta->mesh->plink_timeout = sta->mesh->plink_timeout +
 695					     rand % sta->mesh->plink_timeout;
 696			++sta->mesh->plink_retries;
 697			mod_plink_timer(sta, sta->mesh->plink_timeout);
 698			action = WLAN_SP_MESH_PEERING_OPEN;
 
 
 699			break;
 700		}
 701		reason = WLAN_REASON_MESH_MAX_RETRIES;
 702		fallthrough;
 703	case NL80211_PLINK_CNF_RCVD:
 704		/* confirm timer */
 705		if (!reason)
 706			reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT;
 707		sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 708		mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 709		action = WLAN_SP_MESH_PEERING_CLOSE;
 
 
 710		break;
 711	case NL80211_PLINK_HOLDING:
 712		/* holding timer */
 713		del_timer(&sta->mesh->plink_timer);
 714		mesh_plink_fsm_restart(sta);
 
 715		break;
 716	default:
 
 717		break;
 718	}
 719	spin_unlock_bh(&sta->mesh->plink_lock);
 720	if (action)
 721		mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 722				    sta->mesh->llid, sta->mesh->plid, reason);
 723}
 724
 725static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout)
 
 726{
 727	sta->mesh->plink_timeout = timeout;
 728	mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout));
 729}
 730
 731static bool llid_in_use(struct ieee80211_sub_if_data *sdata,
 732			u16 llid)
 733{
 734	struct ieee80211_local *local = sdata->local;
 735	bool in_use = false;
 736	struct sta_info *sta;
 737
 738	rcu_read_lock();
 739	list_for_each_entry_rcu(sta, &local->sta_list, list) {
 740		if (sdata != sta->sdata)
 741			continue;
 742
 743		if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) {
 744			in_use = true;
 745			break;
 746		}
 747	}
 748	rcu_read_unlock();
 749
 750	return in_use;
 751}
 
 752
 753static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata)
 754{
 755	u16 llid;
 756
 757	do {
 758		get_random_bytes(&llid, sizeof(llid));
 759	} while (llid_in_use(sdata, llid));
 760
 761	return llid;
 762}
 763
 764u32 mesh_plink_open(struct sta_info *sta)
 765{
 
 766	struct ieee80211_sub_if_data *sdata = sta->sdata;
 767	u32 changed;
 768
 769	if (!test_sta_flag(sta, WLAN_STA_AUTH))
 770		return 0;
 771
 772	spin_lock_bh(&sta->mesh->plink_lock);
 773	sta->mesh->llid = mesh_get_new_llid(sdata);
 774	if (sta->mesh->plink_state != NL80211_PLINK_LISTEN &&
 775	    sta->mesh->plink_state != NL80211_PLINK_BLOCKED) {
 776		spin_unlock_bh(&sta->mesh->plink_lock);
 777		return 0;
 778	}
 779	sta->mesh->plink_state = NL80211_PLINK_OPN_SNT;
 780	mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout);
 781	spin_unlock_bh(&sta->mesh->plink_lock);
 782	mpl_dbg(sdata,
 783		"Mesh plink: starting establishment with %pM\n",
 784		sta->sta.addr);
 785
 786	/* set the non-peer mode to active during peering */
 787	changed = ieee80211_mps_local_status_update(sdata);
 788
 789	mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN,
 790			    sta->sta.addr, sta->mesh->llid, 0, 0);
 791	return changed;
 792}
 793
 794u32 mesh_plink_block(struct sta_info *sta)
 795{
 796	u32 changed;
 
 797
 798	spin_lock_bh(&sta->mesh->plink_lock);
 799	changed = __mesh_plink_deactivate(sta);
 800	sta->mesh->plink_state = NL80211_PLINK_BLOCKED;
 801	spin_unlock_bh(&sta->mesh->plink_lock);
 802	mesh_path_flush_by_nexthop(sta);
 803
 804	return changed;
 
 805}
 806
 807static void mesh_plink_close(struct ieee80211_sub_if_data *sdata,
 808			     struct sta_info *sta,
 809			     enum plink_event event)
 810{
 811	struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 812	u16 reason = (event == CLS_ACPT) ?
 813		     WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG;
 814
 815	sta->mesh->reason = reason;
 816	sta->mesh->plink_state = NL80211_PLINK_HOLDING;
 817	mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout);
 818}
 819
 820static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata,
 821				struct sta_info *sta)
 822{
 823	struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 824	u32 changed = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 825
 826	del_timer(&sta->mesh->plink_timer);
 827	sta->mesh->plink_state = NL80211_PLINK_ESTAB;
 828	changed |= mesh_plink_inc_estab_count(sdata);
 829	changed |= mesh_set_ht_prot_mode(sdata);
 830	changed |= mesh_set_short_slot_time(sdata);
 831	mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr);
 832	ieee80211_mps_sta_status_update(sta);
 833	changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode);
 834	return changed;
 835}
 836
 837/**
 838 * mesh_plink_fsm - step @sta MPM based on @event
 839 *
 840 * @sdata: interface
 841 * @sta: mesh neighbor
 842 * @event: peering event
 843 *
 844 * Return: changed MBSS flags
 845 */
 846static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata,
 847			  struct sta_info *sta, enum plink_event event)
 848{
 849	struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg;
 850	enum ieee80211_self_protected_actioncode action = 0;
 851	u32 changed = 0;
 852	bool flush = false;
 853
 854	mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr,
 855		mplstates[sta->mesh->plink_state], mplevents[event]);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 856
 857	spin_lock_bh(&sta->mesh->plink_lock);
 858	switch (sta->mesh->plink_state) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 859	case NL80211_PLINK_LISTEN:
 860		switch (event) {
 861		case CLS_ACPT:
 862			mesh_plink_fsm_restart(sta);
 
 863			break;
 864		case OPN_ACPT:
 865			sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 866			sta->mesh->llid = mesh_get_new_llid(sdata);
 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			action = WLAN_SP_MESH_PEERING_OPEN;
 
 
 873			break;
 874		default:
 
 875			break;
 876		}
 877		break;
 
 878	case NL80211_PLINK_OPN_SNT:
 879		switch (event) {
 880		case OPN_RJCT:
 881		case CNF_RJCT:
 
 882		case CLS_ACPT:
 883			mesh_plink_close(sdata, sta, event);
 884			action = WLAN_SP_MESH_PEERING_CLOSE;
 
 
 
 
 
 
 
 
 
 
 885			break;
 886		case OPN_ACPT:
 887			/* retry timer is left untouched */
 888			sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD;
 889			action = WLAN_SP_MESH_PEERING_CONFIRM;
 
 
 
 
 890			break;
 891		case CNF_ACPT:
 892			sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD;
 893			mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout);
 
 
 
 
 894			break;
 895		default:
 
 896			break;
 897		}
 898		break;
 
 899	case NL80211_PLINK_OPN_RCVD:
 900		switch (event) {
 901		case OPN_RJCT:
 902		case CNF_RJCT:
 
 903		case CLS_ACPT:
 904			mesh_plink_close(sdata, sta, event);
 905			action = WLAN_SP_MESH_PEERING_CLOSE;
 
 
 
 
 
 
 
 
 
 
 906			break;
 907		case OPN_ACPT:
 908			action = WLAN_SP_MESH_PEERING_CONFIRM;
 
 
 
 909			break;
 910		case CNF_ACPT:
 911			changed |= mesh_plink_establish(sdata, sta);
 
 
 
 
 
 
 912			break;
 913		default:
 
 914			break;
 915		}
 916		break;
 
 917	case NL80211_PLINK_CNF_RCVD:
 918		switch (event) {
 919		case OPN_RJCT:
 920		case CNF_RJCT:
 
 921		case CLS_ACPT:
 922			mesh_plink_close(sdata, sta, event);
 923			action = WLAN_SP_MESH_PEERING_CLOSE;
 
 
 
 
 
 
 
 
 
 
 924			break;
 925		case OPN_ACPT:
 926			changed |= mesh_plink_establish(sdata, sta);
 927			action = WLAN_SP_MESH_PEERING_CONFIRM;
 
 
 
 
 
 
 
 928			break;
 929		default:
 
 930			break;
 931		}
 932		break;
 
 933	case NL80211_PLINK_ESTAB:
 934		switch (event) {
 935		case CLS_ACPT:
 936			changed |= __mesh_plink_deactivate(sta);
 937			changed |= mesh_set_ht_prot_mode(sdata);
 938			changed |= mesh_set_short_slot_time(sdata);
 939			mesh_plink_close(sdata, sta, event);
 940			action = WLAN_SP_MESH_PEERING_CLOSE;
 941			flush = true;
 
 
 
 
 
 942			break;
 943		case OPN_ACPT:
 944			action = WLAN_SP_MESH_PEERING_CONFIRM;
 
 
 
 945			break;
 946		default:
 
 947			break;
 948		}
 949		break;
 950	case NL80211_PLINK_HOLDING:
 951		switch (event) {
 952		case CLS_ACPT:
 953			del_timer(&sta->mesh->plink_timer);
 
 954			mesh_plink_fsm_restart(sta);
 
 955			break;
 956		case OPN_ACPT:
 957		case CNF_ACPT:
 958		case OPN_RJCT:
 959		case CNF_RJCT:
 960			action = WLAN_SP_MESH_PEERING_CLOSE;
 
 
 
 
 961			break;
 962		default:
 963			break;
 964		}
 965		break;
 966	default:
 967		/* should not get here, PLINK_BLOCKED is dealt with at the
 968		 * beginning of the function
 969		 */
 
 970		break;
 971	}
 972	spin_unlock_bh(&sta->mesh->plink_lock);
 973	if (flush)
 974		mesh_path_flush_by_nexthop(sta);
 975	if (action) {
 976		mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr,
 977				    sta->mesh->llid, sta->mesh->plid,
 978				    sta->mesh->reason);
 979
 980		/* also send confirm in open case */
 981		if (action == WLAN_SP_MESH_PEERING_OPEN) {
 982			mesh_plink_frame_tx(sdata, sta,
 983					    WLAN_SP_MESH_PEERING_CONFIRM,
 984					    sta->sta.addr, sta->mesh->llid,
 985					    sta->mesh->plid, 0);
 986		}
 987	}
 988
 989	return changed;
 990}
 991
 992/*
 993 * mesh_plink_get_event - get correct MPM event
 994 *
 995 * @sdata: interface
 996 * @sta: peer, leave NULL if processing a frame from a new suitable peer
 997 * @elems: peering management IEs
 998 * @ftype: frame type
 999 * @llid: peer's peer link ID
1000 * @plid: peer's local link ID
1001 *
1002 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as
1003 * an error.
1004 */
1005static enum plink_event
1006mesh_plink_get_event(struct ieee80211_sub_if_data *sdata,
1007		     struct sta_info *sta,
1008		     struct ieee802_11_elems *elems,
1009		     enum ieee80211_self_protected_actioncode ftype,
1010		     u16 llid, u16 plid)
1011{
1012	enum plink_event event = PLINK_UNDEFINED;
1013	u8 ie_len = elems->peering_len;
1014	bool matches_local;
1015
1016	matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE ||
1017			 mesh_matches_local(sdata, elems));
1018
1019	/* deny open request from non-matching peer */
1020	if (!matches_local && !sta) {
1021		event = OPN_RJCT;
1022		goto out;
1023	}
1024
1025	if (!sta) {
1026		if (ftype != WLAN_SP_MESH_PEERING_OPEN) {
1027			mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n");
1028			goto out;
1029		}
1030		/* ftype == WLAN_SP_MESH_PEERING_OPEN */
1031		if (!mesh_plink_free_count(sdata)) {
1032			mpl_dbg(sdata, "Mesh plink error: no more free plinks\n");
1033			goto out;
1034		}
1035
1036		/* new matching peer */
1037		event = OPN_ACPT;
1038		goto out;
1039	} else {
1040		if (!test_sta_flag(sta, WLAN_STA_AUTH)) {
1041			mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n");
1042			goto out;
1043		}
1044		if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED)
1045			goto out;
1046	}
1047
1048	switch (ftype) {
1049	case WLAN_SP_MESH_PEERING_OPEN:
1050		if (!matches_local)
1051			event = OPN_RJCT;
1052		if (!mesh_plink_free_count(sdata) ||
1053		    (sta->mesh->plid && sta->mesh->plid != plid))
1054			event = OPN_IGNR;
1055		else
1056			event = OPN_ACPT;
1057		break;
1058	case WLAN_SP_MESH_PEERING_CONFIRM:
1059		if (!matches_local)
1060			event = CNF_RJCT;
1061		if (!mesh_plink_free_count(sdata) ||
1062		    sta->mesh->llid != llid ||
1063		    (sta->mesh->plid && sta->mesh->plid != plid))
1064			event = CNF_IGNR;
1065		else
1066			event = CNF_ACPT;
1067		break;
1068	case WLAN_SP_MESH_PEERING_CLOSE:
1069		if (sta->mesh->plink_state == NL80211_PLINK_ESTAB)
1070			/* Do not check for llid or plid. This does not
1071			 * follow the standard but since multiple plinks
1072			 * per sta are not supported, it is necessary in
1073			 * order to avoid a livelock when MP A sees an
1074			 * establish peer link to MP B but MP B does not
1075			 * see it. This can be caused by a timeout in
1076			 * B's peer link establishment or B beign
1077			 * restarted.
1078			 */
1079			event = CLS_ACPT;
1080		else if (sta->mesh->plid != plid)
1081			event = CLS_IGNR;
1082		else if (ie_len == 8 && sta->mesh->llid != llid)
1083			event = CLS_IGNR;
1084		else
1085			event = CLS_ACPT;
1086		break;
1087	default:
1088		mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n");
1089		break;
1090	}
1091
1092out:
1093	return event;
1094}
1095
1096static void
1097mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata,
1098			 struct ieee80211_mgmt *mgmt,
1099			 struct ieee802_11_elems *elems,
1100			 struct ieee80211_rx_status *rx_status)
1101{
1102
1103	struct sta_info *sta;
1104	enum plink_event event;
1105	enum ieee80211_self_protected_actioncode ftype;
1106	u32 changed = 0;
1107	u8 ie_len = elems->peering_len;
1108	u16 plid, llid = 0;
1109
1110	if (!elems->peering) {
1111		mpl_dbg(sdata,
1112			"Mesh plink: missing necessary peer link ie\n");
1113		return;
1114	}
1115
1116	if (elems->rsn_len &&
1117	    sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
1118		mpl_dbg(sdata,
1119			"Mesh plink: can't establish link with secure peer\n");
1120		return;
1121	}
1122
1123	ftype = mgmt->u.action.u.self_prot.action_code;
1124	if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) ||
1125	    (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) ||
1126	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6
1127							&& ie_len != 8)) {
1128		mpl_dbg(sdata,
1129			"Mesh plink: incorrect plink ie length %d %d\n",
1130			ftype, ie_len);
1131		return;
1132	}
1133
1134	if (ftype != WLAN_SP_MESH_PEERING_CLOSE &&
1135	    (!elems->mesh_id || !elems->mesh_config)) {
1136		mpl_dbg(sdata, "Mesh plink: missing necessary ie\n");
1137		return;
1138	}
1139	/* Note the lines below are correct, the llid in the frame is the plid
1140	 * from the point of view of this host.
1141	 */
1142	plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering));
1143	if (ftype == WLAN_SP_MESH_PEERING_CONFIRM ||
1144	    (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8))
1145		llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering));
1146
1147	/* WARNING: Only for sta pointer, is dropped & re-acquired */
1148	rcu_read_lock();
1149
1150	sta = sta_info_get(sdata, mgmt->sa);
1151
1152	if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
1153	    !rssi_threshold_check(sdata, sta)) {
1154		mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n",
1155			mgmt->sa);
1156		goto unlock_rcu;
1157	}
1158
1159	/* Now we will figure out the appropriate event... */
1160	event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid);
1161
1162	if (event == OPN_ACPT) {
1163		rcu_read_unlock();
1164		/* allocate sta entry if necessary and update info */
1165		sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status);
1166		if (!sta) {
1167			mpl_dbg(sdata, "Mesh plink: failed to init peer!\n");
1168			goto unlock_rcu;
1169		}
1170		sta->mesh->plid = plid;
1171	} else if (!sta && event == OPN_RJCT) {
1172		mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE,
1173				    mgmt->sa, 0, plid,
1174				    WLAN_REASON_MESH_CONFIG);
1175		goto unlock_rcu;
1176	} else if (!sta || event == PLINK_UNDEFINED) {
1177		/* something went wrong */
1178		goto unlock_rcu;
1179	}
1180
1181	if (event == CNF_ACPT) {
1182		/* 802.11-2012 13.3.7.2 - update plid on CNF if not set */
1183		if (!sta->mesh->plid)
1184			sta->mesh->plid = plid;
1185
1186		sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt));
1187	}
1188
1189	changed |= mesh_plink_fsm(sdata, sta, event);
1190
1191unlock_rcu:
1192	rcu_read_unlock();
1193
1194	if (changed)
1195		ieee80211_mbss_info_change_notify(sdata, changed);
1196}
1197
1198void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
1199			 struct ieee80211_mgmt *mgmt, size_t len,
1200			 struct ieee80211_rx_status *rx_status)
1201{
1202	struct ieee802_11_elems elems;
1203	size_t baselen;
1204	u8 *baseaddr;
1205
1206	/* need action_code, aux */
1207	if (len < IEEE80211_MIN_ACTION_SIZE + 3)
1208		return;
1209
1210	if (sdata->u.mesh.user_mpm)
1211		/* userspace must register for these */
1212		return;
1213
1214	if (is_multicast_ether_addr(mgmt->da)) {
1215		mpl_dbg(sdata,
1216			"Mesh plink: ignore frame from multicast address\n");
1217		return;
1218	}
1219
1220	baseaddr = mgmt->u.action.u.self_prot.variable;
1221	baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt;
1222	if (mgmt->u.action.u.self_prot.action_code ==
1223						WLAN_SP_MESH_PEERING_CONFIRM) {
1224		baseaddr += 4;
1225		baselen += 4;
1226
1227		if (baselen > len)
1228			return;
1229	}
1230	ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems,
1231			       mgmt->bssid, NULL);
1232	mesh_process_plink_frame(sdata, mgmt, &elems, rx_status);
1233}
v3.1
 
  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#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
 17#define mpl_dbg(fmt, args...)	printk(KERN_DEBUG fmt, ##args)
 18#else
 19#define mpl_dbg(fmt, args...)	do { (void)(0); } while (0)
 20#endif
 21
 22#define PLINK_GET_LLID(p) (p + 4)
 23#define PLINK_GET_PLID(p) (p + 6)
 24
 25#define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \
 26				jiffies + HZ * t / 1000))
 27
 28/* Peer link cancel reasons, all subject to ANA approval */
 29#define MESH_LINK_CANCELLED			2
 30#define MESH_MAX_NEIGHBORS			3
 31#define MESH_CAPABILITY_POLICY_VIOLATION	4
 32#define MESH_CLOSE_RCVD				5
 33#define MESH_MAX_RETRIES			6
 34#define MESH_CONFIRM_TIMEOUT			7
 35#define MESH_SECURITY_ROLE_NEGOTIATION_DIFFERS	8
 36#define MESH_SECURITY_AUTHENTICATION_IMPOSSIBLE	9
 37#define MESH_SECURITY_FAILED_VERIFICATION	10
 38
 39#define dot11MeshMaxRetries(s) (s->u.mesh.mshcfg.dot11MeshMaxRetries)
 40#define dot11MeshRetryTimeout(s) (s->u.mesh.mshcfg.dot11MeshRetryTimeout)
 41#define dot11MeshConfirmTimeout(s) (s->u.mesh.mshcfg.dot11MeshConfirmTimeout)
 42#define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
 43#define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
 44
 45enum plink_frame_type {
 46	PLINK_OPEN = 1,
 47	PLINK_CONFIRM,
 48	PLINK_CLOSE
 49};
 50
 51enum plink_event {
 52	PLINK_UNDEFINED,
 53	OPN_ACPT,
 54	OPN_RJCT,
 55	OPN_IGNR,
 56	CNF_ACPT,
 57	CNF_RJCT,
 58	CNF_IGNR,
 59	CLS_ACPT,
 60	CLS_IGNR
 61};
 62
 63static inline
 64void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
 65{
 66	atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
 67	mesh_accept_plinks_update(sdata);
 68}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 69
 70static inline
 71void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
 
 72{
 73	atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
 74	mesh_accept_plinks_update(sdata);
 
 
 
 75}
 76
 77/**
 78 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine
 79 *
 80 * @sta: mesh peer link to restart
 81 *
 82 * Locking: this function must be called holding sta->lock
 83 */
 84static inline void mesh_plink_fsm_restart(struct sta_info *sta)
 85{
 86	sta->plink_state = NL80211_PLINK_LISTEN;
 87	sta->llid = sta->plid = sta->reason = 0;
 88	sta->plink_retries = 0;
 
 89}
 90
 91/*
 92 * NOTE: This is just an alias for sta_info_alloc(), see notes
 93 *       on it in the lifecycle management section!
 
 
 
 
 
 
 94 */
 95static struct sta_info *mesh_plink_alloc(struct ieee80211_sub_if_data *sdata,
 96					 u8 *hw_addr, u32 rates)
 97{
 98	struct ieee80211_local *local = sdata->local;
 
 99	struct sta_info *sta;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
100
101	if (local->num_sta >= MESH_MAX_PLINKS)
102		return NULL;
103
104	sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL);
105	if (!sta)
106		return NULL;
 
 
 
 
 
 
 
 
 
 
107
108	sta->flags = WLAN_STA_AUTHORIZED | WLAN_STA_AUTH;
109	sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
110	rate_control_rate_init(sta);
111
112	return sta;
 
 
 
113}
114
115/**
116 * __mesh_plink_deactivate - deactivate mesh peer link
117 *
118 * @sta: mesh peer link to deactivate
119 *
120 * All mesh paths with this peer as next hop will be flushed
121 *
122 * Locking: the caller must hold sta->lock
 
123 */
124static bool __mesh_plink_deactivate(struct sta_info *sta)
125{
126	struct ieee80211_sub_if_data *sdata = sta->sdata;
127	bool deactivated = false;
 
 
128
129	if (sta->plink_state == NL80211_PLINK_ESTAB) {
130		mesh_plink_dec_estab_count(sdata);
131		deactivated = true;
 
 
 
 
132	}
133	sta->plink_state = NL80211_PLINK_BLOCKED;
134	mesh_path_flush_by_nexthop(sta);
135
136	return deactivated;
137}
 
 
 
 
 
 
 
 
 
 
 
 
 
138
139/**
140 * mesh_plink_deactivate - deactivate mesh peer link
141 *
142 * @sta: mesh peer link to deactivate
143 *
144 * All mesh paths with this peer as next hop will be flushed
145 */
146void mesh_plink_deactivate(struct sta_info *sta)
147{
148	struct ieee80211_sub_if_data *sdata = sta->sdata;
149	bool deactivated;
150
151	spin_lock_bh(&sta->lock);
152	deactivated = __mesh_plink_deactivate(sta);
153	spin_unlock_bh(&sta->lock);
154
155	if (deactivated)
156		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 
 
 
 
 
 
 
 
 
157}
158
159static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata,
160		enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,
161		__le16 reason) {
 
 
162	struct ieee80211_local *local = sdata->local;
163	struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400 +
164			sdata->u.mesh.ie_len);
165	struct ieee80211_mgmt *mgmt;
166	bool include_plid = false;
167	static const u8 meshpeeringproto[] = { 0x00, 0x0F, 0xAC, 0x2A };
168	u8 *pos;
169	int ie_len;
170
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
171	if (!skb)
172		return -1;
173	skb_reserve(skb, local->hw.extra_tx_headroom);
174	/* 25 is the size of the common mgmt part (24) plus the size of the
175	 * common action part (1)
176	 */
177	mgmt = (struct ieee80211_mgmt *)
178		skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));
179	memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));
180	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
181					  IEEE80211_STYPE_ACTION);
182	memcpy(mgmt->da, da, ETH_ALEN);
183	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
184	memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
185	mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION;
186	mgmt->u.action.u.plink_action.action_code = action;
 
 
 
 
 
 
 
 
 
 
 
187
188	if (action == PLINK_CLOSE)
189		mgmt->u.action.u.plink_action.aux = reason;
190	else {
191		mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);
192		if (action == PLINK_CONFIRM) {
193			pos = skb_put(skb, 4);
194			/* two-byte status code followed by two-byte AID */
195			memset(pos, 0, 2);
196			memcpy(pos + 2, &plid, 2);
197		}
198		mesh_mgmt_ies_add(skb, sdata);
 
 
 
 
 
 
 
 
 
199	}
200
201	/* Add Peer Link Management element */
202	switch (action) {
203	case PLINK_OPEN:
204		ie_len = 6;
205		break;
206	case PLINK_CONFIRM:
207		ie_len = 8;
208		include_plid = true;
209		break;
210	case PLINK_CLOSE:
211	default:
212		if (!plid)
213			ie_len = 8;
214		else {
215			ie_len = 10;
216			include_plid = true;
217		}
 
218		break;
 
 
 
219	}
220
 
 
 
221	pos = skb_put(skb, 2 + ie_len);
222	*pos++ = WLAN_EID_PEER_LINK;
223	*pos++ = ie_len;
224	memcpy(pos, meshpeeringproto, sizeof(meshpeeringproto));
225	pos += 4;
226	memcpy(pos, &llid, 2);
 
227	if (include_plid) {
 
228		pos += 2;
229		memcpy(pos, &plid, 2);
230	}
231	if (action == PLINK_CLOSE) {
 
232		pos += 2;
233		memcpy(pos, &reason, 2);
234	}
235
 
 
 
 
 
 
 
 
 
 
 
 
 
 
236	ieee80211_tx_skb(sdata, skb);
237	return 0;
 
 
 
238}
239
240void mesh_neighbour_update(u8 *hw_addr, u32 rates,
241		struct ieee80211_sub_if_data *sdata,
242		struct ieee802_11_elems *elems)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
243{
244	struct ieee80211_local *local = sdata->local;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
245	struct sta_info *sta;
 
 
 
 
 
 
 
 
 
 
246
247	rcu_read_lock();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
248
249	sta = sta_info_get(sdata, hw_addr);
250	if (!sta) {
 
 
 
251		rcu_read_unlock();
252		/* Userspace handles peer allocation when security is enabled
253		 * */
254		if (sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED)
255			cfg80211_notify_new_peer_candidate(sdata->dev, hw_addr,
256					elems->ie_start, elems->total_len,
257					GFP_KERNEL);
258		else
259			sta = mesh_plink_alloc(sdata, hw_addr, rates);
260		if (!sta)
261			return;
262		if (sta_info_insert_rcu(sta)) {
263			rcu_read_unlock();
264			return;
265		}
 
 
 
 
 
266	}
267
268	sta->last_rx = jiffies;
269	sta->sta.supp_rates[local->hw.conf.channel->band] = rates;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
270	if (mesh_peer_accepts_plinks(elems) &&
271			sta->plink_state == NL80211_PLINK_LISTEN &&
272			sdata->u.mesh.accepting_plinks &&
273			sdata->u.mesh.mshcfg.auto_open_plinks)
274		mesh_plink_open(sta);
 
275
 
 
276	rcu_read_unlock();
 
277}
278
279static void mesh_plink_timer(unsigned long data)
280{
 
281	struct sta_info *sta;
282	__le16 llid, plid, reason;
283	struct ieee80211_sub_if_data *sdata;
 
 
284
285	/*
286	 * This STA is valid because sta_info_destroy() will
287	 * del_timer_sync() this timer after having made sure
288	 * it cannot be readded (by deleting the plink.)
289	 */
290	sta = (struct sta_info *) data;
291
292	if (sta->sdata->local->quiescing) {
293		sta->plink_timer_was_running = true;
 
 
 
 
 
 
 
 
 
 
 
 
 
294		return;
295	}
296
297	spin_lock_bh(&sta->lock);
298	if (sta->ignore_plink_timer) {
299		sta->ignore_plink_timer = false;
300		spin_unlock_bh(&sta->lock);
 
 
 
301		return;
302	}
303	mpl_dbg("Mesh plink timer for %pM fired on state %d\n",
304		sta->sta.addr, sta->plink_state);
305	reason = 0;
306	llid = sta->llid;
307	plid = sta->plid;
308	sdata = sta->sdata;
 
309
310	switch (sta->plink_state) {
311	case NL80211_PLINK_OPN_RCVD:
312	case NL80211_PLINK_OPN_SNT:
313		/* retry timer */
314		if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {
315			u32 rand;
316			mpl_dbg("Mesh plink for %pM (retry, timeout): %d %d\n",
317				sta->sta.addr, sta->plink_retries,
318				sta->plink_timeout);
 
319			get_random_bytes(&rand, sizeof(u32));
320			sta->plink_timeout = sta->plink_timeout +
321					     rand % sta->plink_timeout;
322			++sta->plink_retries;
323			mod_plink_timer(sta, sta->plink_timeout);
324			spin_unlock_bh(&sta->lock);
325			mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
326					    0, 0);
327			break;
328		}
329		reason = cpu_to_le16(MESH_MAX_RETRIES);
330		/* fall through on else */
331	case NL80211_PLINK_CNF_RCVD:
332		/* confirm timer */
333		if (!reason)
334			reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);
335		sta->plink_state = NL80211_PLINK_HOLDING;
336		mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
337		spin_unlock_bh(&sta->lock);
338		mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid, plid,
339				    reason);
340		break;
341	case NL80211_PLINK_HOLDING:
342		/* holding timer */
343		del_timer(&sta->plink_timer);
344		mesh_plink_fsm_restart(sta);
345		spin_unlock_bh(&sta->lock);
346		break;
347	default:
348		spin_unlock_bh(&sta->lock);
349		break;
350	}
 
 
 
 
351}
352
353#ifdef CONFIG_PM
354void mesh_plink_quiesce(struct sta_info *sta)
355{
356	if (del_timer_sync(&sta->plink_timer))
357		sta->plink_timer_was_running = true;
358}
359
360void mesh_plink_restart(struct sta_info *sta)
 
361{
362	if (sta->plink_timer_was_running) {
363		add_timer(&sta->plink_timer);
364		sta->plink_timer_was_running = false;
 
 
 
 
 
 
 
 
 
 
365	}
 
 
 
366}
367#endif
368
369static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)
370{
371	sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);
372	sta->plink_timer.data = (unsigned long) sta;
373	sta->plink_timer.function = mesh_plink_timer;
374	sta->plink_timeout = timeout;
375	add_timer(&sta->plink_timer);
 
 
376}
377
378int mesh_plink_open(struct sta_info *sta)
379{
380	__le16 llid;
381	struct ieee80211_sub_if_data *sdata = sta->sdata;
 
382
383	if (!test_sta_flags(sta, WLAN_STA_AUTH))
384		return -EPERM;
385
386	spin_lock_bh(&sta->lock);
387	get_random_bytes(&llid, 2);
388	sta->llid = llid;
389	if (sta->plink_state != NL80211_PLINK_LISTEN) {
390		spin_unlock_bh(&sta->lock);
391		return -EBUSY;
392	}
393	sta->plink_state = NL80211_PLINK_OPN_SNT;
394	mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
395	spin_unlock_bh(&sta->lock);
396	mpl_dbg("Mesh plink: starting establishment with %pM\n",
 
397		sta->sta.addr);
398
399	return mesh_plink_frame_tx(sdata, PLINK_OPEN,
400				   sta->sta.addr, llid, 0, 0);
 
 
 
 
401}
402
403void mesh_plink_block(struct sta_info *sta)
404{
405	struct ieee80211_sub_if_data *sdata = sta->sdata;
406	bool deactivated;
407
408	spin_lock_bh(&sta->lock);
409	deactivated = __mesh_plink_deactivate(sta);
410	sta->plink_state = NL80211_PLINK_BLOCKED;
411	spin_unlock_bh(&sta->lock);
 
412
413	if (deactivated)
414		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
415}
416
 
 
 
 
 
 
 
 
 
 
 
 
417
418void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt,
419			 size_t len, struct ieee80211_rx_status *rx_status)
420{
421	struct ieee80211_local *local = sdata->local;
422	struct ieee802_11_elems elems;
423	struct sta_info *sta;
424	enum plink_event event;
425	enum plink_frame_type ftype;
426	size_t baselen;
427	bool deactivated, matches_local = true;
428	u8 ie_len;
429	u8 *baseaddr;
430	__le16 plid, llid, reason;
431#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG
432	static const char *mplstates[] = {
433		[NL80211_PLINK_LISTEN] = "LISTEN",
434		[NL80211_PLINK_OPN_SNT] = "OPN-SNT",
435		[NL80211_PLINK_OPN_RCVD] = "OPN-RCVD",
436		[NL80211_PLINK_CNF_RCVD] = "CNF_RCVD",
437		[NL80211_PLINK_ESTAB] = "ESTAB",
438		[NL80211_PLINK_HOLDING] = "HOLDING",
439		[NL80211_PLINK_BLOCKED] = "BLOCKED"
440	};
441#endif
442
443	/* need action_code, aux */
444	if (len < IEEE80211_MIN_ACTION_SIZE + 3)
445		return;
 
 
 
 
 
 
 
446
447	if (is_multicast_ether_addr(mgmt->da)) {
448		mpl_dbg("Mesh plink: ignore frame from multicast address");
449		return;
450	}
 
 
 
 
 
 
 
 
 
 
 
 
451
452	baseaddr = mgmt->u.action.u.plink_action.variable;
453	baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;
454	if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {
455		baseaddr += 4;
456		baselen += 4;
457	}
458	ieee802_11_parse_elems(baseaddr, len - baselen, &elems);
459	if (!elems.peer_link) {
460		mpl_dbg("Mesh plink: missing necessary peer link ie\n");
461		return;
462	}
463	if (elems.rsn_len &&
464			sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
465		mpl_dbg("Mesh plink: can't establish link with secure peer\n");
466		return;
467	}
468
469	ftype = mgmt->u.action.u.plink_action.action_code;
470	ie_len = elems.peer_link_len;
471	if ((ftype == PLINK_OPEN && ie_len != 6) ||
472	    (ftype == PLINK_CONFIRM && ie_len != 8) ||
473	    (ftype == PLINK_CLOSE && ie_len != 8 && ie_len != 10)) {
474		mpl_dbg("Mesh plink: incorrect plink ie length %d %d\n",
475		    ftype, ie_len);
476		return;
477	}
478
479	if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {
480		mpl_dbg("Mesh plink: missing necessary ie\n");
481		return;
482	}
483	/* Note the lines below are correct, the llid in the frame is the plid
484	 * from the point of view of this host.
485	 */
486	memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);
487	if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 10))
488		memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);
489
490	rcu_read_lock();
491
492	sta = sta_info_get(sdata, mgmt->sa);
493	if (!sta && ftype != PLINK_OPEN) {
494		mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");
495		rcu_read_unlock();
496		return;
497	}
498
499	if (sta && !test_sta_flags(sta, WLAN_STA_AUTH)) {
500		mpl_dbg("Mesh plink: Action frame from non-authed peer\n");
501		rcu_read_unlock();
502		return;
503	}
504
505	if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) {
506		rcu_read_unlock();
507		return;
508	}
509
510	/* Now we will figure out the appropriate event... */
511	event = PLINK_UNDEFINED;
512	if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, sdata))) {
513		matches_local = false;
514		switch (ftype) {
515		case PLINK_OPEN:
516			event = OPN_RJCT;
517			break;
518		case PLINK_CONFIRM:
519			event = CNF_RJCT;
520			break;
521		case PLINK_CLOSE:
522			/* avoid warning */
523			break;
524		}
525	}
526
527	if (!sta && !matches_local) {
528		rcu_read_unlock();
529		reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
530		llid = 0;
531		mesh_plink_frame_tx(sdata, PLINK_CLOSE, mgmt->sa, llid,
532				    plid, reason);
533		return;
534	} else if (!sta) {
535		/* ftype == PLINK_OPEN */
536		u32 rates;
537
538		rcu_read_unlock();
539
540		if (!mesh_plink_free_count(sdata)) {
541			mpl_dbg("Mesh plink error: no more free plinks\n");
542			return;
543		}
544
545		rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);
546		sta = mesh_plink_alloc(sdata, mgmt->sa, rates);
547		if (!sta) {
548			mpl_dbg("Mesh plink error: plink table full\n");
549			return;
550		}
551		if (sta_info_insert_rcu(sta)) {
552			rcu_read_unlock();
553			return;
554		}
555		event = OPN_ACPT;
556		spin_lock_bh(&sta->lock);
557	} else if (matches_local) {
558		spin_lock_bh(&sta->lock);
559		switch (ftype) {
560		case PLINK_OPEN:
561			if (!mesh_plink_free_count(sdata) ||
562			    (sta->plid && sta->plid != plid))
563				event = OPN_IGNR;
564			else
565				event = OPN_ACPT;
566			break;
567		case PLINK_CONFIRM:
568			if (!mesh_plink_free_count(sdata) ||
569			    (sta->llid != llid || sta->plid != plid))
570				event = CNF_IGNR;
571			else
572				event = CNF_ACPT;
573			break;
574		case PLINK_CLOSE:
575			if (sta->plink_state == NL80211_PLINK_ESTAB)
576				/* Do not check for llid or plid. This does not
577				 * follow the standard but since multiple plinks
578				 * per sta are not supported, it is necessary in
579				 * order to avoid a livelock when MP A sees an
580				 * establish peer link to MP B but MP B does not
581				 * see it. This can be caused by a timeout in
582				 * B's peer link establishment or B beign
583				 * restarted.
584				 */
585				event = CLS_ACPT;
586			else if (sta->plid != plid)
587				event = CLS_IGNR;
588			else if (ie_len == 7 && sta->llid != llid)
589				event = CLS_IGNR;
590			else
591				event = CLS_ACPT;
592			break;
593		default:
594			mpl_dbg("Mesh plink: unknown frame subtype\n");
595			spin_unlock_bh(&sta->lock);
596			rcu_read_unlock();
597			return;
598		}
599	} else {
600		spin_lock_bh(&sta->lock);
601	}
602
603	mpl_dbg("Mesh plink (peer, state, llid, plid, event): %pM %s %d %d %d\n",
604		mgmt->sa, mplstates[sta->plink_state],
605		le16_to_cpu(sta->llid), le16_to_cpu(sta->plid),
606		event);
607	reason = 0;
608	switch (sta->plink_state) {
609		/* spin_unlock as soon as state is updated at each case */
610	case NL80211_PLINK_LISTEN:
611		switch (event) {
612		case CLS_ACPT:
613			mesh_plink_fsm_restart(sta);
614			spin_unlock_bh(&sta->lock);
615			break;
616		case OPN_ACPT:
617			sta->plink_state = NL80211_PLINK_OPN_RCVD;
618			sta->plid = plid;
619			get_random_bytes(&llid, 2);
620			sta->llid = llid;
621			mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));
622			spin_unlock_bh(&sta->lock);
623			mesh_plink_frame_tx(sdata, PLINK_OPEN, sta->sta.addr, llid,
624					    0, 0);
625			mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr,
626					    llid, plid, 0);
627			break;
628		default:
629			spin_unlock_bh(&sta->lock);
630			break;
631		}
632		break;
633
634	case NL80211_PLINK_OPN_SNT:
635		switch (event) {
636		case OPN_RJCT:
637		case CNF_RJCT:
638			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
639		case CLS_ACPT:
640			if (!reason)
641				reason = cpu_to_le16(MESH_CLOSE_RCVD);
642			sta->reason = reason;
643			sta->plink_state = NL80211_PLINK_HOLDING;
644			if (!mod_plink_timer(sta,
645					     dot11MeshHoldingTimeout(sdata)))
646				sta->ignore_plink_timer = true;
647
648			llid = sta->llid;
649			spin_unlock_bh(&sta->lock);
650			mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
651					    plid, reason);
652			break;
653		case OPN_ACPT:
654			/* retry timer is left untouched */
655			sta->plink_state = NL80211_PLINK_OPN_RCVD;
656			sta->plid = plid;
657			llid = sta->llid;
658			spin_unlock_bh(&sta->lock);
659			mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
660					    plid, 0);
661			break;
662		case CNF_ACPT:
663			sta->plink_state = NL80211_PLINK_CNF_RCVD;
664			if (!mod_plink_timer(sta,
665					     dot11MeshConfirmTimeout(sdata)))
666				sta->ignore_plink_timer = true;
667
668			spin_unlock_bh(&sta->lock);
669			break;
670		default:
671			spin_unlock_bh(&sta->lock);
672			break;
673		}
674		break;
675
676	case NL80211_PLINK_OPN_RCVD:
677		switch (event) {
678		case OPN_RJCT:
679		case CNF_RJCT:
680			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
681		case CLS_ACPT:
682			if (!reason)
683				reason = cpu_to_le16(MESH_CLOSE_RCVD);
684			sta->reason = reason;
685			sta->plink_state = NL80211_PLINK_HOLDING;
686			if (!mod_plink_timer(sta,
687					     dot11MeshHoldingTimeout(sdata)))
688				sta->ignore_plink_timer = true;
689
690			llid = sta->llid;
691			spin_unlock_bh(&sta->lock);
692			mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
693					    plid, reason);
694			break;
695		case OPN_ACPT:
696			llid = sta->llid;
697			spin_unlock_bh(&sta->lock);
698			mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
699					    plid, 0);
700			break;
701		case CNF_ACPT:
702			del_timer(&sta->plink_timer);
703			sta->plink_state = NL80211_PLINK_ESTAB;
704			spin_unlock_bh(&sta->lock);
705			mesh_plink_inc_estab_count(sdata);
706			ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
707			mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
708				sta->sta.addr);
709			break;
710		default:
711			spin_unlock_bh(&sta->lock);
712			break;
713		}
714		break;
715
716	case NL80211_PLINK_CNF_RCVD:
717		switch (event) {
718		case OPN_RJCT:
719		case CNF_RJCT:
720			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);
721		case CLS_ACPT:
722			if (!reason)
723				reason = cpu_to_le16(MESH_CLOSE_RCVD);
724			sta->reason = reason;
725			sta->plink_state = NL80211_PLINK_HOLDING;
726			if (!mod_plink_timer(sta,
727					     dot11MeshHoldingTimeout(sdata)))
728				sta->ignore_plink_timer = true;
729
730			llid = sta->llid;
731			spin_unlock_bh(&sta->lock);
732			mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
733					    plid, reason);
734			break;
735		case OPN_ACPT:
736			del_timer(&sta->plink_timer);
737			sta->plink_state = NL80211_PLINK_ESTAB;
738			spin_unlock_bh(&sta->lock);
739			mesh_plink_inc_estab_count(sdata);
740			ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
741			mpl_dbg("Mesh plink with %pM ESTABLISHED\n",
742				sta->sta.addr);
743			mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
744					    plid, 0);
745			break;
746		default:
747			spin_unlock_bh(&sta->lock);
748			break;
749		}
750		break;
751
752	case NL80211_PLINK_ESTAB:
753		switch (event) {
754		case CLS_ACPT:
755			reason = cpu_to_le16(MESH_CLOSE_RCVD);
756			sta->reason = reason;
757			deactivated = __mesh_plink_deactivate(sta);
758			sta->plink_state = NL80211_PLINK_HOLDING;
759			llid = sta->llid;
760			mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata));
761			spin_unlock_bh(&sta->lock);
762			if (deactivated)
763				ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
764			mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr, llid,
765					    plid, reason);
766			break;
767		case OPN_ACPT:
768			llid = sta->llid;
769			spin_unlock_bh(&sta->lock);
770			mesh_plink_frame_tx(sdata, PLINK_CONFIRM, sta->sta.addr, llid,
771					    plid, 0);
772			break;
773		default:
774			spin_unlock_bh(&sta->lock);
775			break;
776		}
777		break;
778	case NL80211_PLINK_HOLDING:
779		switch (event) {
780		case CLS_ACPT:
781			if (del_timer(&sta->plink_timer))
782				sta->ignore_plink_timer = 1;
783			mesh_plink_fsm_restart(sta);
784			spin_unlock_bh(&sta->lock);
785			break;
786		case OPN_ACPT:
787		case CNF_ACPT:
788		case OPN_RJCT:
789		case CNF_RJCT:
790			llid = sta->llid;
791			reason = sta->reason;
792			spin_unlock_bh(&sta->lock);
793			mesh_plink_frame_tx(sdata, PLINK_CLOSE, sta->sta.addr,
794					    llid, plid, reason);
795			break;
796		default:
797			spin_unlock_bh(&sta->lock);
798		}
799		break;
800	default:
801		/* should not get here, PLINK_BLOCKED is dealt with at the
802		 * beginning of the function
803		 */
804		spin_unlock_bh(&sta->lock);
805		break;
806	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
807
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
808	rcu_read_unlock();
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
809}