mac80211: mesh peer link implementation
authorLuis Carlos Cobo <luisca@cozybit.com>
Sat, 23 Feb 2008 14:17:13 +0000 (15:17 +0100)
committerJohn W. Linville <linville@tuxdriver.com>
Thu, 6 Mar 2008 20:30:41 +0000 (15:30 -0500)
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>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
net/mac80211/mesh_plink.c [new file with mode: 0644]

diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
new file mode 100644 (file)
index 0000000..5cd97e9
--- /dev/null
@@ -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);
+}