[PATCH 10/18] mac80211: mesh peer link implementation

[Johannes Berg <johannes@sipsolutions.net>]

From: Luis Carlos Cobo <luisca@cozybit.com>

This file implements mesh discovery and peer link establishment support using
the mesh peer link table provided in mesh_plinktbl.c.

Secure peer links have not been implemented yet.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 net/mac80211/mesh_plink.c |  755 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 755 insertions(+)
 create mode 100644 net/mac80211/mesh_plink.c

--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ everything/net/mac80211/mesh_plink.c	2008-02-23 14:38:26.000000000 +0100
@@ -0,0 +1,755 @@
+/*
+ * 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);
+			mpl_dbg("Mesh plink with %s ESTABLISHED\n",
+					print_mac(mac, sta->addr));
+			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
+					    plid, 0);
+			break;
+		default:
+			spin_unlock_bh(&sta->plink_lock);
+			break;
+		}
+		break;
+
+	case ESTAB:
+		switch (event) {
+		case CLS_ACPT:
+			reason = cpu_to_le16(MESH_CLOSE_RCVD);
+			sta->reason = reason;
+			mesh_plink_deactivate(sta);
+			sta->plink_state = HOLDING;
+			llid = sta->llid;
+			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 OPN_ACPT:
+			llid = sta->llid;
+			spin_unlock_bh(&sta->plink_lock);
+			mesh_plink_frame_tx(dev, PLINK_CONFIRM, sta->addr, llid,
+					    plid, 0);
+			break;
+		default:
+			spin_unlock_bh(&sta->plink_lock);
+			break;
+		}
+		break;
+	case HOLDING:
+		switch (event) {
+		case CLS_ACPT:
+			if (del_timer(&sta->plink_timer)) {
+				sta->ignore_plink_timer = 1;
+				sta_info_put(sta);
+			}
+			mesh_plink_fsm_restart(sta);
+			spin_unlock_bh(&sta->plink_lock);
+			break;
+		case OPN_ACPT:
+		case CNF_ACPT:
+		case OPN_RJCT:
+		case CNF_RJCT:
+			llid = sta->llid;
+			reason = sta->reason;
+			spin_unlock_bh(&sta->plink_lock);
+			mesh_plink_frame_tx(dev, PLINK_CLOSE, sta->addr, llid,
+					    plid, reason);
+			break;
+		default:
+			spin_unlock_bh(&sta->plink_lock);
+		}
+		break;
+	default:
+		/* should not get here, BLOCKED is dealt with at the beggining
+		 * of the function
+		 */
+		spin_unlock_bh(&sta->plink_lock);
+		break;
+	}
+	sta_info_put(sta);
+}

--