/*
 * Copyright (c) 2008, 2009 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 <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "mesh.h"

/* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */
#define INIT_PATHS_SIZE_ORDER   2

/* Keep the mean chain length below this constant */
#define MEAN_CHAIN_LEN          2

#define MPATH_EXPIRED(mpath) ((mpath->flags & MESH_PATH_ACTIVE) && \
                                time_after(jiffies, mpath->exp_time) && \
                                !(mpath->flags & MESH_PATH_FIXED))

struct mpath_node {
        struct hlist_node list;
        struct rcu_head rcu;
        /* This indirection allows two different tables to point to the same
         * mesh_path structure, useful when resizing
         */
        struct mesh_path *mpath;
};

static struct mesh_table *mesh_paths;
static struct mesh_table *mpp_paths; /* Store paths for MPP&MAP */

int mesh_paths_generation;
static void __mesh_table_free(struct mesh_table *tbl)
{
        kfree(tbl->hash_buckets);
        kfree(tbl->hashwlock);
        kfree(tbl);
}

void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
{
        struct hlist_head *mesh_hash;
        struct hlist_node *p, *q;
        int i;

        mesh_hash = tbl->hash_buckets;
        for (i = 0; i <= tbl->hash_mask; i++) {
                spin_lock(&tbl->hashwlock[i]);
                hlist_for_each_safe(p, q, &mesh_hash[i]) {
                        tbl->free_node(p, free_leafs);
                        atomic_dec(&tbl->entries);
                }
                spin_unlock(&tbl->hashwlock[i]);
        }
        __mesh_table_free(tbl);
}

static struct mesh_table *mesh_table_grow(struct mesh_table *tbl)
{
        struct mesh_table *newtbl;
        struct hlist_head *oldhash;
        struct hlist_node *p, *q;
        int i;

        if (atomic_read(&tbl->entries)
                        < tbl->mean_chain_len * (tbl->hash_mask + 1))
                goto endgrow;

        newtbl = mesh_table_alloc(tbl->size_order + 1);
        if (!newtbl)
                goto endgrow;

        newtbl->free_node = tbl->free_node;
        newtbl->mean_chain_len = tbl->mean_chain_len;
        newtbl->copy_node = tbl->copy_node;
        atomic_set(&newtbl->entries, atomic_read(&tbl->entries));

        oldhash = tbl->hash_buckets;
        for (i = 0; i <= tbl->hash_mask; i++)
                hlist_for_each(p, &oldhash[i])
                        if (tbl->copy_node(p, newtbl) < 0)
                                goto errcopy;

        return newtbl;

errcopy:
        for (i = 0; i <= newtbl->hash_mask; i++) {
                hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
                        tbl->free_node(p, 0);
        }
        __mesh_table_free(newtbl);
endgrow:
        return NULL;
}


/* This lock will have the grow table function as writer and add / delete nodes
 * as readers. When reading the table (i.e. doing lookups) we are well protected
 * by RCU
 */
static DEFINE_RWLOCK(pathtbl_resize_lock);

/**
 *
 * mesh_path_assign_nexthop - update mesh path next hop
 *
 * @mpath: mesh path to update
 * @sta: next hop to assign
 *
 * Locking: mpath->state_lock must be held when calling this function
 */
void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
{
        struct sk_buff *skb;
        struct ieee80211_hdr *hdr;
        struct sk_buff_head tmpq;
        unsigned long flags;

        rcu_assign_pointer(mpath->next_hop, sta);

        __skb_queue_head_init(&tmpq);

        spin_lock_irqsave(&mpath->frame_queue.lock, flags);

        while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) {
                hdr = (struct ieee80211_hdr *) skb->data;
                memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
                __skb_queue_tail(&tmpq, skb);
        }

        skb_queue_splice(&tmpq, &mpath->frame_queue);
        spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
}


/**
 * mesh_path_lookup - look up a path in the mesh path table
 * @dst: hardware address (ETH_ALEN length) of destination
 * @sdata: local subif
 *
 * Returns: pointer to the mesh path structure, or NULL if not found
 *
 * Locking: must be called within a read rcu section.
 */
struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
{
        struct mesh_path *mpath;
        struct hlist_node *n;
        struct hlist_head *bucket;
        struct mesh_table *tbl;
        struct mpath_node *node;

        tbl = rcu_dereference(mesh_paths);

        bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
        hlist_for_each_entry_rcu(node, n, bucket, list) {
                mpath = node->mpath;
                if (mpath->sdata == sdata &&
                                memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
                        if (MPATH_EXPIRED(mpath)) {
                                spin_lock_bh(&mpath->state_lock);
                                if (MPATH_EXPIRED(mpath))
                                        mpath->flags &= ~MESH_PATH_ACTIVE;
                                spin_unlock_bh(&mpath->state_lock);
                        }
                        return mpath;
                }
        }
        return NULL;
}

struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
{
        struct mesh_path *mpath;
        struct hlist_node *n;
        struct hlist_head *bucket;
        struct mesh_table *tbl;
        struct mpath_node *node;

        tbl = rcu_dereference(mpp_paths);

        bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
        hlist_for_each_entry_rcu(node, n, bucket, list) {
                mpath = node->mpath;
                if (mpath->sdata == sdata &&
                    memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
                        if (MPATH_EXPIRED(mpath)) {
                                spin_lock_bh(&mpath->state_lock);
                                if (MPATH_EXPIRED(mpath))
                                        mpath->flags &= ~MESH_PATH_ACTIVE;
                                spin_unlock_bh(&mpath->state_lock);
                        }
                        return mpath;
                }
        }
        return NULL;
}


/**
 * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
 * @idx: index
 * @sdata: local subif, or NULL for all entries
 *
 * Returns: pointer to the mesh path structure, or NULL if not found.
 *
 * Locking: must be called within a read rcu section.
 */
struct mesh_path *mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data *sdata)
{
        struct mpath_node *node;
        struct hlist_node *p;
        int i;
        int j = 0;

        for_each_mesh_entry(mesh_paths, p, node, i) {
                if (sdata && node->mpath->sdata != sdata)
                        continue;
                if (j++ == idx) {
                        if (MPATH_EXPIRED(node->mpath)) {
                                spin_lock_bh(&node->mpath->state_lock);
                                if (MPATH_EXPIRED(node->mpath))
                                        node->mpath->flags &= ~MESH_PATH_ACTIVE;
                                spin_unlock_bh(&node->mpath->state_lock);
                        }
                        return node->mpath;
                }
        }

        return NULL;
}

/**
 * mesh_path_add - allocate and add a new path to the mesh path table
 * @addr: destination address of the path (ETH_ALEN length)
 * @sdata: local subif
 *
 * Returns: 0 on success
 *
 * State: the initial state of the new path is set to 0
 */
int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        struct ieee80211_local *local = sdata->local;
        struct mesh_path *mpath, *new_mpath;
        struct mpath_node *node, *new_node;
        struct hlist_head *bucket;
        struct hlist_node *n;
        int grow = 0;
        int err = 0;
        u32 hash_idx;

        if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0)
                /* never add ourselves as neighbours */
                return -ENOTSUPP;

        if (is_multicast_ether_addr(dst))
                return -ENOTSUPP;

        if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
                return -ENOSPC;

        err = -ENOMEM;
        new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
        if (!new_mpath)
                goto err_path_alloc;

        new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
        if (!new_node)
                goto err_node_alloc;

        read_lock(&pathtbl_resize_lock);
        memcpy(new_mpath->dst, dst, ETH_ALEN);
        new_mpath->sdata = sdata;
        new_mpath->flags = 0;
        skb_queue_head_init(&new_mpath->frame_queue);
        new_node->mpath = new_mpath;
        new_mpath->timer.data = (unsigned long) new_mpath;
        new_mpath->timer.function = mesh_path_timer;
        new_mpath->exp_time = jiffies;
        spin_lock_init(&new_mpath->state_lock);
        init_timer(&new_mpath->timer);

        hash_idx = mesh_table_hash(dst, sdata, mesh_paths);
        bucket = &mesh_paths->hash_buckets[hash_idx];

        spin_lock(&mesh_paths->hashwlock[hash_idx]);

        err = -EEXIST;
        hlist_for_each_entry(node, n, bucket, list) {
                mpath = node->mpath;
                if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
                        goto err_exists;
        }

        hlist_add_head_rcu(&new_node->list, bucket);
        if (atomic_inc_return(&mesh_paths->entries) >=
                mesh_paths->mean_chain_len * (mesh_paths->hash_mask + 1))
                grow = 1;

        mesh_paths_generation++;

        spin_unlock(&mesh_paths->hashwlock[hash_idx]);
        read_unlock(&pathtbl_resize_lock);
        if (grow) {
                set_bit(MESH_WORK_GROW_MPATH_TABLE,  &ifmsh->wrkq_flags);
                ieee80211_queue_work(&local->hw, &sdata->work);
        }
        return 0;

err_exists:
        spin_unlock(&mesh_paths->hashwlock[hash_idx]);
        read_unlock(&pathtbl_resize_lock);
        kfree(new_node);
err_node_alloc:
        kfree(new_mpath);
err_path_alloc:
        atomic_dec(&sdata->u.mesh.mpaths);
        return err;
}

void mesh_mpath_table_grow(void)
{
        struct mesh_table *oldtbl, *newtbl;

        write_lock(&pathtbl_resize_lock);
        oldtbl = mesh_paths;
        newtbl = mesh_table_grow(mesh_paths);
        if (!newtbl) {
                write_unlock(&pathtbl_resize_lock);
                return;
        }
        rcu_assign_pointer(mesh_paths, newtbl);
        write_unlock(&pathtbl_resize_lock);

        synchronize_rcu();
        mesh_table_free(oldtbl, false);
}

void mesh_mpp_table_grow(void)
{
        struct mesh_table *oldtbl, *newtbl;

        write_lock(&pathtbl_resize_lock);
        oldtbl = mpp_paths;
        newtbl = mesh_table_grow(mpp_paths);
        if (!newtbl) {
                write_unlock(&pathtbl_resize_lock);
                return;
        }
        rcu_assign_pointer(mpp_paths, newtbl);
        write_unlock(&pathtbl_resize_lock);

        synchronize_rcu();
        mesh_table_free(oldtbl, false);
}

int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
        struct ieee80211_local *local = sdata->local;
        struct mesh_path *mpath, *new_mpath;
        struct mpath_node *node, *new_node;
        struct hlist_head *bucket;
        struct hlist_node *n;
        int grow = 0;
        int err = 0;
        u32 hash_idx;

        if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0)
                /* never add ourselves as neighbours */
                return -ENOTSUPP;

        if (is_multicast_ether_addr(dst))
                return -ENOTSUPP;

        err = -ENOMEM;
        new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC);
        if (!new_mpath)
                goto err_path_alloc;

        new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
        if (!new_node)
                goto err_node_alloc;

        read_lock(&pathtbl_resize_lock);
        memcpy(new_mpath->dst, dst, ETH_ALEN);
        memcpy(new_mpath->mpp, mpp, ETH_ALEN);
        new_mpath->sdata = sdata;
        new_mpath->flags = 0;
        skb_queue_head_init(&new_mpath->frame_queue);
        new_node->mpath = new_mpath;
        new_mpath->exp_time = jiffies;
        spin_lock_init(&new_mpath->state_lock);

        hash_idx = mesh_table_hash(dst, sdata, mpp_paths);
        bucket = &mpp_paths->hash_buckets[hash_idx];

        spin_lock(&mpp_paths->hashwlock[hash_idx]);

        err = -EEXIST;
        hlist_for_each_entry(node, n, bucket, list) {
                mpath = node->mpath;
                if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
                        goto err_exists;
        }

        hlist_add_head_rcu(&new_node->list, bucket);
        if (atomic_inc_return(&mpp_paths->entries) >=
                mpp_paths->mean_chain_len * (mpp_paths->hash_mask + 1))
                grow = 1;

        spin_unlock(&mpp_paths->hashwlock[hash_idx]);
        read_unlock(&pathtbl_resize_lock);
        if (grow) {
                set_bit(MESH_WORK_GROW_MPP_TABLE,  &ifmsh->wrkq_flags);
                ieee80211_queue_work(&local->hw, &sdata->work);
        }
        return 0;

err_exists:
        spin_unlock(&mpp_paths->hashwlock[hash_idx]);
        read_unlock(&pathtbl_resize_lock);
        kfree(new_node);
err_node_alloc:
        kfree(new_mpath);
err_path_alloc:
        return err;
}


/**
 * mesh_plink_broken - deactivates paths and sends perr when a link breaks
 *
 * @sta: broken peer link
 *
 * This function must be called from the rate control algorithm if enough
 * delivery errors suggest that a peer link is no longer usable.
 */
void mesh_plink_broken(struct sta_info *sta)
{
        static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
        struct mesh_path *mpath;
        struct mpath_node *node;
        struct hlist_node *p;
        struct ieee80211_sub_if_data *sdata = sta->sdata;
        int i;

        rcu_read_lock();
        for_each_mesh_entry(mesh_paths, p, node, i) {
                mpath = node->mpath;
                spin_lock_bh(&mpath->state_lock);
                if (mpath->next_hop == sta &&
                    mpath->flags & MESH_PATH_ACTIVE &&
                    !(mpath->flags & MESH_PATH_FIXED)) {
                        mpath->flags &= ~MESH_PATH_ACTIVE;
                        ++mpath->sn;
                        spin_unlock_bh(&mpath->state_lock);
                        mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl,
                                        mpath->dst, cpu_to_le32(mpath->sn),
                                        cpu_to_le16(PERR_RCODE_DEST_UNREACH),
                                        bcast, sdata);
                } else
                spin_unlock_bh(&mpath->state_lock);
        }
        rcu_read_unlock();
}

/**
 * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
 *
 * @sta - mesh peer to match
 *
 * RCU notes: this function is called when a mesh plink transitions from
 * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
 * allows path creation. This will happen before the sta can be freed (because
 * sta_info_destroy() calls this) so any reader in a rcu read block will be
 * protected against the plink disappearing.
 */
void mesh_path_flush_by_nexthop(struct sta_info *sta)
{
        struct mesh_path *mpath;
        struct mpath_node *node;
        struct hlist_node *p;
        int i;

        for_each_mesh_entry(mesh_paths, p, node, i) {
                mpath = node->mpath;
                if (mpath->next_hop == sta)
                        mesh_path_del(mpath->dst, mpath->sdata);
        }
}

void mesh_path_flush(struct ieee80211_sub_if_data *sdata)
{
        struct mesh_path *mpath;
        struct mpath_node *node;
        struct hlist_node *p;
        int i;

        for_each_mesh_entry(mesh_paths, p, node, i) {
                mpath = node->mpath;
                if (mpath->sdata == sdata)
                        mesh_path_del(mpath->dst, mpath->sdata);
        }
}

static void mesh_path_node_reclaim(struct rcu_head *rp)
{
        struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
        struct ieee80211_sub_if_data *sdata = node->mpath->sdata;

        del_timer_sync(&node->mpath->timer);
        atomic_dec(&sdata->u.mesh.mpaths);
        kfree(node->mpath);
        kfree(node);
}

/**
 * mesh_path_del - delete a mesh path from the table
 *
 * @addr: dst address (ETH_ALEN length)
 * @sdata: local subif
 *
 * Returns: 0 if successful
 */
int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata)
{
        struct mesh_path *mpath;
        struct mpath_node *node;
        struct hlist_head *bucket;
        struct hlist_node *n;
        int hash_idx;
        int err = 0;

        read_lock(&pathtbl_resize_lock);
        hash_idx = mesh_table_hash(addr, sdata, mesh_paths);
        bucket = &mesh_paths->hash_buckets[hash_idx];

        spin_lock(&mesh_paths->hashwlock[hash_idx]);
        hlist_for_each_entry(node, n, bucket, list) {
                mpath = node->mpath;
                if (mpath->sdata == sdata &&
                                memcmp(addr, mpath->dst, ETH_ALEN) == 0) {
                        spin_lock_bh(&mpath->state_lock);
                        mpath->flags |= MESH_PATH_RESOLVING;
                        hlist_del_rcu(&node->list);
                        call_rcu(&node->rcu, mesh_path_node_reclaim);
                        atomic_dec(&mesh_paths->entries);
                        spin_unlock_bh(&mpath->state_lock);
                        goto enddel;
                }
        }

        err = -ENXIO;
enddel:
        mesh_paths_generation++;
        spin_unlock(&mesh_paths->hashwlock[hash_idx]);
        read_unlock(&pathtbl_resize_lock);
        return err;
}

/**
 * mesh_path_tx_pending - sends pending frames in a mesh path queue
 *
 * @mpath: mesh path to activate
 *
 * Locking: the state_lock of the mpath structure must NOT be held when calling
 * this function.
 */
void mesh_path_tx_pending(struct mesh_path *mpath)
{
        if (mpath->flags & MESH_PATH_ACTIVE)
                ieee80211_add_pending_skbs(mpath->sdata->local,
                                &mpath->frame_queue);
}

/**
 * mesh_path_discard_frame - discard a frame whose path could not be resolved
 *
 * @skb: frame to discard
 * @sdata: network subif the frame was to be sent through
 *
 * If the frame was being forwarded from another MP, a PERR frame will be sent
 * to the precursor.  The precursor's address (i.e. the previous hop) was saved
 * in addr1 of the frame-to-be-forwarded, and would only be overwritten once
 * the destination is successfully resolved.
 *
 * Locking: the function must me called within a rcu_read_lock region
 */
void mesh_path_discard_frame(struct sk_buff *skb,
                             struct ieee80211_sub_if_data *sdata)
{
        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
        struct mesh_path *mpath;
        u32 sn = 0;

        if (memcmp(hdr->addr4, sdata->vif.addr, ETH_ALEN) != 0) {
                u8 *ra, *da;

                da = hdr->addr3;
                ra = hdr->addr1;
                mpath = mesh_path_lookup(da, sdata);
                if (mpath)
                        sn = ++mpath->sn;
                mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, skb->data,
                                   cpu_to_le32(sn),
                                   cpu_to_le16(PERR_RCODE_NO_ROUTE), ra, sdata);
        }

        kfree_skb(skb);
        sdata->u.mesh.mshstats.dropped_frames_no_route++;
}

/**
 * mesh_path_flush_pending - free the pending queue of a mesh path
 *
 * @mpath: mesh path whose queue has to be freed
 *
 * Locking: the function must me called withing a rcu_read_lock region
 */
void mesh_path_flush_pending(struct mesh_path *mpath)
{
        struct sk_buff *skb;

        while ((skb = skb_dequeue(&mpath->frame_queue)) &&
                        (mpath->flags & MESH_PATH_ACTIVE))
                mesh_path_discard_frame(skb, mpath->sdata);
}

/**
 * mesh_path_fix_nexthop - force a specific next hop for a mesh path
 *
 * @mpath: the mesh path to modify
 * @next_hop: the next hop to force
 *
 * Locking: this function must be called holding mpath->state_lock
 */
void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop)
{
        spin_lock_bh(&mpath->state_lock);
        mesh_path_assign_nexthop(mpath, next_hop);
        mpath->sn = 0xffff;
        mpath->metric = 0;
        mpath->hop_count = 0;
        mpath->exp_time = 0;
        mpath->flags |= MESH_PATH_FIXED;
        mesh_path_activate(mpath);
        spin_unlock_bh(&mpath->state_lock);
        mesh_path_tx_pending(mpath);
}

static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
{
        struct mesh_path *mpath;
        struct mpath_node *node = hlist_entry(p, struct mpath_node, list);
        mpath = node->mpath;
        hlist_del_rcu(p);
        if (free_leafs)
                kfree(mpath);
        kfree(node);
}

static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
{
        struct mesh_path *mpath;
        struct mpath_node *node, *new_node;
        u32 hash_idx;

        new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
        if (new_node == NULL)
                return -ENOMEM;

        node = hlist_entry(p, struct mpath_node, list);
        mpath = node->mpath;
        new_node->mpath = mpath;
        hash_idx = mesh_table_hash(mpath->dst, mpath->sdata, newtbl);
        hlist_add_head(&new_node->list,
                        &newtbl->hash_buckets[hash_idx]);
        return 0;
}

int mesh_pathtbl_init(void)
{
        mesh_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
        if (!mesh_paths)
                return -ENOMEM;
        mesh_paths->free_node = &mesh_path_node_free;
        mesh_paths->copy_node = &mesh_path_node_copy;
        mesh_paths->mean_chain_len = MEAN_CHAIN_LEN;

        mpp_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
        if (!mpp_paths) {
                mesh_table_free(mesh_paths, true);
                return -ENOMEM;
        }
        mpp_paths->free_node = &mesh_path_node_free;
        mpp_paths->copy_node = &mesh_path_node_copy;
        mpp_paths->mean_chain_len = MEAN_CHAIN_LEN;

        return 0;
}

void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
{
        struct mesh_path *mpath;
        struct mpath_node *node;
        struct hlist_node *p;
        int i;

        read_lock(&pathtbl_resize_lock);
        for_each_mesh_entry(mesh_paths, p, node, i) {
                if (node->mpath->sdata != sdata)
                        continue;
                mpath = node->mpath;
                spin_lock_bh(&mpath->state_lock);
                if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
                    (!(mpath->flags & MESH_PATH_FIXED)) &&
                        time_after(jiffies,
                         mpath->exp_time + MESH_PATH_EXPIRE)) {
                        spin_unlock_bh(&mpath->state_lock);
                        mesh_path_del(mpath->dst, mpath->sdata);
                } else
                        spin_unlock_bh(&mpath->state_lock);
        }
        read_unlock(&pathtbl_resize_lock);
}

void mesh_pathtbl_unregister(void)
{
        mesh_table_free(mesh_paths, true);
        mesh_table_free(mpp_paths, true);
}