mac80211: mesh peer link implementation

/*

 * Copyright (c) 2008 open80211s Ltd.

 * Author:     Luis Carlos Cobo <luisca@cozybit.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include "ieee80211_i.h"

#include "ieee80211_rate.h"

#include "mesh.h"

#include <linux/random.h>

#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG

#define mpl_dbg(fmt, args...)	printk(KERN_DEBUG fmt, ##args)

#else

#define mpl_dbg(fmt, args...)	do { (void)(0); } while (0)

#endif

#define IEEE80211_FC(type, stype) cpu_to_le16(type | stype)

#define PLINK_GET_FRAME_SUBTYPE(p) (p)

#define PLINK_GET_LLID(p) (p + 1)

#define PLINK_GET_PLID(p) (p + 3)

#define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \

				jiffies + HZ * t / 1000))

/* Peer link cancel reasons, all subject to ANA approval */

#define MESH_LINK_CANCELLED			2

#define MESH_MAX_NEIGHBORS			3

#define MESH_CAPABILITY_POLICY_VIOLATION	4

#define MESH_CLOSE_RCVD				5

#define MESH_MAX_RETRIES			6

#define MESH_CONFIRM_TIMEOUT			7

#define MESH_SECURITY_ROLE_NEGOTIATION_DIFFERS	8

#define MESH_SECURITY_AUTHENTICATION_IMPOSSIBLE	9

#define MESH_SECURITY_FAILED_VERIFICATION	10

#define dot11MeshMaxRetries(s) (s->u.sta.mshcfg.dot11MeshMaxRetries)

#define dot11MeshRetryTimeout(s) (s->u.sta.mshcfg.dot11MeshRetryTimeout)

#define dot11MeshConfirmTimeout(s) (s->u.sta.mshcfg.dot11MeshConfirmTimeout)

#define dot11MeshHoldingTimeout(s) (s->u.sta.mshcfg.dot11MeshHoldingTimeout)

#define dot11MeshMaxPeerLinks(s) (s->u.sta.mshcfg.dot11MeshMaxPeerLinks)

enum plink_frame_type {

	PLINK_OPEN = 0,

	PLINK_CONFIRM,

	PLINK_CLOSE

};

enum plink_event {

	PLINK_UNDEFINED,

	OPN_ACPT,

	OPN_RJCT,

	OPN_IGNR,

	CNF_ACPT,

	CNF_RJCT,

	CNF_IGNR,

	CLS_ACPT,

	CLS_IGNR

};

static inline

void mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)

{

	atomic_inc(&sdata->u.sta.mshstats.estab_plinks);

	mesh_accept_plinks_update(sdata->dev);

}

static inline

void mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)

{

	atomic_dec(&sdata->u.sta.mshstats.estab_plinks);

	mesh_accept_plinks_update(sdata->dev);

}

/**

 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine

 *

 * @sta: mes peer link to restart

 *

 * Locking: this function must be called holding sta->plink_lock

 */

static inline void mesh_plink_fsm_restart(struct sta_info *sta)

{

	sta->plink_state = LISTEN;

	sta->llid = sta->plid = sta->reason = sta->plink_retries = 0;

}

/**

 * mesh_plink_add - allocate and add a new mesh peer link

 *

 * @hw_addr: hardware address (ETH_ALEN length)

 * @rates: rates the mesh peer supports

 * @dev: local mesh interface

 *

 * The initial state of the new plink is set to LISTEN

 *

 * Returns: non-NULL on success, ERR_PTR() on error.

 */

struct sta_info *mesh_plink_add(u8 *hw_addr, u64 rates, struct net_device *dev)

{

	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

	struct sta_info *sta;

	if (memcmp(hw_addr, dev->dev_addr, ETH_ALEN) == 0)

		/* never add ourselves as neighbours */

		return ERR_PTR(-EINVAL);

	if (is_multicast_ether_addr(hw_addr))

		return ERR_PTR(-EINVAL);

	if (local->num_sta >= MESH_MAX_PLINKS)

		return ERR_PTR(-ENOSPC);

	sta = sta_info_add(local, dev, hw_addr, GFP_KERNEL);

	if (IS_ERR(sta))

		return sta;

	sta->plink_state = LISTEN;

	spin_lock_init(&sta->plink_lock);

	init_timer(&sta->plink_timer);

	sta->flags |= WLAN_STA_AUTHORIZED;

	sta->supp_rates[local->hw.conf.channel->band] = rates;

	rate_control_rate_init(sta, local);

	mesh_accept_plinks_update(dev);

	return sta;

}

/**

 * mesh_plink_deactivate - deactivate mesh peer link

 *

 * @sta: mesh peer link to deactivate

 *

 * All mesh paths with this peer as next hop will be flushed

 *

 * Locking: the caller must hold sta->plink_lock

 */

void mesh_plink_deactivate(struct sta_info *sta)

{

	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

	if (sta->plink_state == ESTAB)

		mesh_plink_dec_estab_count(sdata);

	sta->plink_state = BLOCKED;

	mesh_path_flush_by_nexthop(sta);

}

static int mesh_plink_frame_tx(struct net_device *dev,

		enum plink_frame_type action, u8 *da, __le16 llid, __le16 plid,

		__le16 reason) {

	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

	struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);

	struct ieee80211_mgmt *mgmt;

	bool include_plid = false;

	u8 *pos;

	int ie_len;

	if (!skb)

		return -1;

	skb_reserve(skb, local->hw.extra_tx_headroom);

	/* 25 is the size of the common mgmt part (24) plus the size of the

	 * common action part (1)

	 */

	mgmt = (struct ieee80211_mgmt *)

		skb_put(skb, 25 + sizeof(mgmt->u.action.u.plink_action));

	memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.plink_action));

	mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,

					   IEEE80211_STYPE_ACTION);

	memcpy(mgmt->da, da, ETH_ALEN);

	memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);

	/* BSSID is left zeroed, wildcard value */

	mgmt->u.action.category = PLINK_CATEGORY;

	mgmt->u.action.u.plink_action.action_code = action;

	if (action == PLINK_CLOSE)

		mgmt->u.action.u.plink_action.aux = reason;

	else {

		mgmt->u.action.u.plink_action.aux = cpu_to_le16(0x0);

		if (action == PLINK_CONFIRM) {

			pos = skb_put(skb, 4);

			/* two-byte status code followed by two-byte AID */

			memset(pos, 0, 4);

		}

		mesh_mgmt_ies_add(skb, dev);

	}

	/* Add Peer Link Management element */

	switch (action) {

	case PLINK_OPEN:

		ie_len = 3;

		break;

	case PLINK_CONFIRM:

		ie_len = 5;

		include_plid = true;

		break;

	case PLINK_CLOSE:

	default:

		if (!plid)

			ie_len = 5;

		else {

			ie_len = 7;

			include_plid = true;

		}

		break;

	}

	pos = skb_put(skb, 2 + ie_len);

	*pos++ = WLAN_EID_PEER_LINK;

	*pos++ = ie_len;

	*pos++ = action;

	memcpy(pos, &llid, 2);

	if (include_plid) {

		pos += 2;

		memcpy(pos, &plid, 2);

	}

	if (action == PLINK_CLOSE) {

		pos += 2;

		memcpy(pos, &reason, 2);

	}

	ieee80211_sta_tx(dev, skb, 0);

	return 0;

}

void mesh_neighbour_update(u8 *hw_addr, u64 rates, struct net_device *dev,

			   bool peer_accepting_plinks)

{

	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

	struct sta_info *sta;

	sta = sta_info_get(local, hw_addr);

	if (!sta) {

		sta = mesh_plink_add(hw_addr, rates, dev);

		if (IS_ERR(sta))

			return;

	}

	sta->last_rx = jiffies;

	sta->supp_rates[local->hw.conf.channel->band] = rates;

	if (peer_accepting_plinks && sta->plink_state == LISTEN &&

			sdata->u.sta.accepting_plinks &&

			sdata->u.sta.mshcfg.auto_open_plinks)

		mesh_plink_open(sta);

	sta_info_put(sta);

}

static void mesh_plink_timer(unsigned long data)

{

	struct sta_info *sta;

	__le16 llid, plid, reason;

	struct net_device *dev = NULL;

	struct ieee80211_sub_if_data *sdata;

#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG

	DECLARE_MAC_BUF(mac);

#endif

	sta = (struct sta_info *) data;

	spin_lock_bh(&sta->plink_lock);

	if (sta->ignore_plink_timer) {

		sta->ignore_plink_timer = false;

		spin_unlock_bh(&sta->plink_lock);

		return;

	}

	mpl_dbg("Mesh plink timer for %s fired on state %d\n",

			print_mac(mac, sta->addr), sta->plink_state);

	reason = 0;

	llid = sta->llid;

	plid = sta->plid;

	dev = sta->dev;

	sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	switch (sta->plink_state) {

	case OPN_RCVD:

	case OPN_SNT:

		/* retry timer */

		if (sta->plink_retries < dot11MeshMaxRetries(sdata)) {

			u32 rand;

			mpl_dbg("Mesh plink for %s (retry, timeout): %d %d\n",

					print_mac(mac, sta->addr),

					sta->plink_retries, sta->plink_timeout);

			get_random_bytes(&rand, sizeof(u32));

			sta->plink_timeout = sta->plink_timeout +

					     rand % sta->plink_timeout;

			++sta->plink_retries;

			if (!mod_plink_timer(sta, sta->plink_timeout))

				__sta_info_get(sta);

			spin_unlock_bh(&sta->plink_lock);

			mesh_plink_frame_tx(dev, PLINK_OPEN, sta->addr, llid,

					    0, 0);

			break;

		}

		reason = cpu_to_le16(MESH_MAX_RETRIES);

		/* fall through on else */

	case CNF_RCVD:

		/* confirm timer */

		if (!reason)

			reason = cpu_to_le16(MESH_CONFIRM_TIMEOUT);

		sta->plink_state = HOLDING;

		if (!mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata)))

			__sta_info_get(sta);

		spin_unlock_bh(&sta->plink_lock);

		mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid, plid,

				    reason);

		break;

	case HOLDING:

		/* holding timer */

		if (del_timer(&sta->plink_timer))

			sta_info_put(sta);

		mesh_plink_fsm_restart(sta);

		spin_unlock_bh(&sta->plink_lock);

		break;

	default:

		spin_unlock_bh(&sta->plink_lock);

		break;

	}

	sta_info_put(sta);

}

static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout)

{

	sta->plink_timer.expires = jiffies + (HZ * timeout / 1000);

	sta->plink_timer.data = (unsigned long) sta;

	sta->plink_timer.function = mesh_plink_timer;

	sta->plink_timeout = timeout;

	__sta_info_get(sta);

	add_timer(&sta->plink_timer);

}

int mesh_plink_open(struct sta_info *sta)

{

	__le16 llid;

	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG

	DECLARE_MAC_BUF(mac);

#endif

	spin_lock_bh(&sta->plink_lock);

	get_random_bytes(&llid, 2);

	sta->llid = llid;

	if (sta->plink_state != LISTEN) {

		spin_unlock_bh(&sta->plink_lock);

		sta_info_put(sta);

		return -EBUSY;

	}

	sta->plink_state = OPN_SNT;

	mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));

	spin_unlock_bh(&sta->plink_lock);

	mpl_dbg("Mesh plink: starting establishment with %s\n",

		print_mac(mac, sta->addr));

	return mesh_plink_frame_tx(sta->dev, PLINK_OPEN, sta->addr, llid, 0, 0);

}

void mesh_plink_block(struct sta_info *sta)

{

#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG

	DECLARE_MAC_BUF(mac);

#endif

	spin_lock_bh(&sta->plink_lock);

	mesh_plink_deactivate(sta);

	sta->plink_state = BLOCKED;

	spin_unlock_bh(&sta->plink_lock);

}

int mesh_plink_close(struct sta_info *sta)

{

	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);

	int llid, plid, reason;

#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG

	DECLARE_MAC_BUF(mac);

#endif

	mpl_dbg("Mesh plink: closing link with %s\n",

			print_mac(mac, sta->addr));

	spin_lock_bh(&sta->plink_lock);

	sta->reason = cpu_to_le16(MESH_LINK_CANCELLED);

	reason = sta->reason;

	if (sta->plink_state == LISTEN || sta->plink_state == BLOCKED) {

		mesh_plink_fsm_restart(sta);

		spin_unlock_bh(&sta->plink_lock);

		sta_info_put(sta);

		return 0;

	} else if (sta->plink_state == ESTAB) {

		mesh_plink_deactivate(sta);

		/* The timer should not be running */

		if (!mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata)))

			__sta_info_get(sta);

	} else if (!mod_plink_timer(sta, dot11MeshHoldingTimeout(sdata)))

		sta->ignore_plink_timer = true;

	sta->plink_state = HOLDING;

	llid = sta->llid;

	plid = sta->plid;

	spin_unlock_bh(&sta->plink_lock);

	mesh_plink_frame_tx(sta->dev, PLINK_CLOSE, sta->addr, llid, plid,

			    reason);

	return 0;

}

void mesh_rx_plink_frame(struct net_device *dev, struct ieee80211_mgmt *mgmt,

			 size_t len, struct ieee80211_rx_status *rx_status)

{

	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);

	struct ieee802_11_elems elems;

	struct sta_info *sta;

	enum plink_event event;

	enum plink_frame_type ftype;

	size_t baselen;

	u8 ie_len;

	u8 *baseaddr;

	__le16 plid, llid, reason;

#ifdef CONFIG_MAC80211_VERBOSE_MPL_DEBUG

	DECLARE_MAC_BUF(mac);

#endif

	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

	if (is_multicast_ether_addr(mgmt->da)) {

		mpl_dbg("Mesh plink: ignore frame from multicast address");

		return;

	}

	baseaddr = mgmt->u.action.u.plink_action.variable;

	baselen = (u8 *) mgmt->u.action.u.plink_action.variable - (u8 *) mgmt;

	if (mgmt->u.action.u.plink_action.action_code == PLINK_CONFIRM) {

		baseaddr += 4;

		baselen -= 4;

	}

	ieee802_11_parse_elems(baseaddr, len - baselen, &elems);

	if (!elems.peer_link) {

		mpl_dbg("Mesh plink: missing necessary peer link ie\n");

		return;

	}

	ftype = *((u8 *)PLINK_GET_FRAME_SUBTYPE(elems.peer_link));

	ie_len = elems.peer_link_len;

	if ((ftype == PLINK_OPEN && ie_len != 3) ||

	    (ftype == PLINK_CONFIRM && ie_len != 5) ||

	    (ftype == PLINK_CLOSE && ie_len != 5 && ie_len != 7)) {

		mpl_dbg("Mesh plink: incorrect plink ie length\n");

		return;

	}

	if (ftype != PLINK_CLOSE && (!elems.mesh_id || !elems.mesh_config)) {

		mpl_dbg("Mesh plink: missing necessary ie\n");

		return;

	}

	/* Note the lines below are correct, the llid in the frame is the plid

	 * from the point of view of this host.

	 */

	memcpy(&plid, PLINK_GET_LLID(elems.peer_link), 2);

	if (ftype == PLINK_CONFIRM || (ftype == PLINK_CLOSE && ie_len == 7))

		memcpy(&llid, PLINK_GET_PLID(elems.peer_link), 2);

	sta = sta_info_get(local, mgmt->sa);

	if (!sta && ftype != PLINK_OPEN) {

		mpl_dbg("Mesh plink: cls or cnf from unknown peer\n");

		return;

	}

	if (sta && sta->plink_state == BLOCKED) {

		sta_info_put(sta);

		return;

	}

	/* Now we will figure out the appropriate event... */

	event = PLINK_UNDEFINED;

	if (ftype != PLINK_CLOSE && (!mesh_matches_local(&elems, dev))) {

		switch (ftype) {

		case PLINK_OPEN:

			event = OPN_RJCT;

			break;

		case PLINK_CONFIRM:

			event = CNF_RJCT;

			break;

		case PLINK_CLOSE:

			/* avoid warning */

			break;

		}

		spin_lock_bh(&sta->plink_lock);

	} else if (!sta) {

		/* ftype == PLINK_OPEN */

		u64 rates;

		if (!mesh_plink_free_count(sdata)) {

			mpl_dbg("Mesh plink error: no more free plinks\n");

			return;

		}

		rates = ieee80211_sta_get_rates(local, &elems, rx_status->band);

		sta = mesh_plink_add(mgmt->sa, rates, dev);

		if (IS_ERR(sta)) {

			mpl_dbg("Mesh plink error: plink table full\n");

			return;

		}

		event = OPN_ACPT;

		spin_lock_bh(&sta->plink_lock);

	} else {

		spin_lock_bh(&sta->plink_lock);

		switch (ftype) {

		case PLINK_OPEN:

			if (!mesh_plink_free_count(sdata) ||

					(sta->plid && sta->plid != plid))

				event = OPN_IGNR;

			else

				event = OPN_ACPT;

			break;

		case PLINK_CONFIRM:

			if (!mesh_plink_free_count(sdata) ||

				(sta->llid != llid || sta->plid != plid))

				event = CNF_IGNR;

			else

				event = CNF_ACPT;

			break;

		case PLINK_CLOSE:

			if (sta->plink_state == ESTAB)

				/* Do not check for llid or plid. This does not

				 * follow the standard but since multiple plinks

				 * per sta are not supported, it is necessary in

				 * order to avoid a livelock when MP A sees an

				 * establish peer link to MP B but MP B does not

				 * see it. This can be caused by a timeout in

				 * B's peer link establishment or B beign

				 * restarted.

				 */

				event = CLS_ACPT;

			else if (sta->plid != plid)

				event = CLS_IGNR;

			else if (ie_len == 7 && sta->llid != llid)

				event = CLS_IGNR;

			else

				event = CLS_ACPT;

			break;

		default:

			mpl_dbg("Mesh plink: unknown frame subtype\n");

			spin_unlock_bh(&sta->plink_lock);

			sta_info_put(sta);

			return;

		}

	}

	mpl_dbg("Mesh plink (peer, state, llid, plid, event): %s %d %d %d %d\n",

			print_mac(mac, mgmt->sa), sta->plink_state,

			__le16_to_cpu(sta->llid), __le16_to_cpu(sta->plid),

			event);

	reason = 0;

	switch (sta->plink_state) {

		/* spin_unlock as soon as state is updated at each case */

	case LISTEN:

		switch (event) {

		case CLS_ACPT:

			mesh_plink_fsm_restart(sta);

			spin_unlock_bh(&sta->plink_lock);

			break;

		case OPN_ACPT:

			sta->plink_state = OPN_RCVD;

			sta->plid = plid;

			get_random_bytes(&llid, 2);

			sta->llid = llid;

			mesh_plink_timer_set(sta, dot11MeshRetryTimeout(sdata));

			spin_unlock_bh(&sta->plink_lock);

			mesh_plink_frame_tx(dev, PLINK_OPEN, sta->addr, llid,

					    0, 0);

			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr,

					    llid, plid, 0);

			break;

		default:

			spin_unlock_bh(&sta->plink_lock);

			break;

		}

		break;

	case OPN_SNT:

		switch (event) {

		case OPN_RJCT:

		case CNF_RJCT:

			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);

		case CLS_ACPT:

			if (!reason)

				reason = cpu_to_le16(MESH_CLOSE_RCVD);

			sta->reason = reason;

			sta->plink_state = HOLDING;

			if (!mod_plink_timer(sta,

					     dot11MeshHoldingTimeout(sdata)))

				sta->ignore_plink_timer = true;

			llid = sta->llid;

			spin_unlock_bh(&sta->plink_lock);

			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,

					    plid, reason);

			break;

		case OPN_ACPT:

			/* retry timer is left untouched */

			sta->plink_state = OPN_RCVD;

			sta->plid = plid;

			llid = sta->llid;

			spin_unlock_bh(&sta->plink_lock);

			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,

					    plid, 0);

			break;

		case CNF_ACPT:

			sta->plink_state = CNF_RCVD;

			if (!mod_plink_timer(sta,

					     dot11MeshConfirmTimeout(sdata)))

				sta->ignore_plink_timer = true;

			spin_unlock_bh(&sta->plink_lock);

			break;

		default:

			spin_unlock_bh(&sta->plink_lock);

			break;

		}

		break;

	case OPN_RCVD:

		switch (event) {

		case OPN_RJCT:

		case CNF_RJCT:

			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);

		case CLS_ACPT:

			if (!reason)

				reason = cpu_to_le16(MESH_CLOSE_RCVD);

			sta->reason = reason;

			sta->plink_state = HOLDING;

			if (!mod_plink_timer(sta,

					     dot11MeshHoldingTimeout(sdata)))

				sta->ignore_plink_timer = true;

			llid = sta->llid;

			spin_unlock_bh(&sta->plink_lock);

			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,

					    plid, reason);

			break;

		case OPN_ACPT:

			llid = sta->llid;

			spin_unlock_bh(&sta->plink_lock);

			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,

					    plid, 0);

			break;

		case CNF_ACPT:

			if (del_timer(&sta->plink_timer))

				sta_info_put(sta);

			sta->plink_state = ESTAB;

			mesh_plink_inc_estab_count(sdata);

			spin_unlock_bh(&sta->plink_lock);

			mpl_dbg("Mesh plink with %s ESTABLISHED\n",

					print_mac(mac, sta->addr));

			break;

		default:

			spin_unlock_bh(&sta->plink_lock);

			break;

		}

		break;

	case CNF_RCVD:

		switch (event) {

		case OPN_RJCT:

		case CNF_RJCT:

			reason = cpu_to_le16(MESH_CAPABILITY_POLICY_VIOLATION);

		case CLS_ACPT:

			if (!reason)

				reason = cpu_to_le16(MESH_CLOSE_RCVD);

			sta->reason = reason;

			sta->plink_state = HOLDING;

			if (!mod_plink_timer(sta,

					     dot11MeshHoldingTimeout(sdata)))

				sta->ignore_plink_timer = true;

			llid = sta->llid;

			spin_unlock_bh(&sta->plink_lock);

			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,

					    plid, reason);

		case OPN_ACPT:

			if (del_timer(&sta->plink_timer))

				sta_info_put(sta);

			sta->plink_state = ESTAB;

			mesh_plink_inc_estab_count(sdata);

			spin_unlock_bh(&sta->plink_lock);