[linux.git] / net / mac80211 / mesh_pathtbl.c

/*
 * Copyright (c) 2008 open80211s Ltd.
 * Author:     Luis Carlos Cobo <[email protected]>
 *
 * 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/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 */

/* 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 sucess
 *
 * 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 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;

	might_sleep();

	if (memcmp(dst, sdata->dev->dev_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_KERNEL);
	if (!new_mpath)
		goto err_path_alloc;

	new_node = kmalloc(sizeof(struct mpath_node), GFP_KERNEL);
	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;

	spin_unlock(&mesh_paths->hashwlock[hash_idx]);
	read_unlock(&pathtbl_resize_lock);
	if (grow) {
		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 0;
		}
		rcu_assign_pointer(mesh_paths, newtbl);
		write_unlock(&pathtbl_resize_lock);

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


int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata)
{
	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;

	might_sleep();

	if (memcmp(dst, sdata->dev->dev_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_KERNEL);
	if (!new_mpath)
		goto err_path_alloc;

	new_node = kmalloc(sizeof(struct mpath_node), GFP_KERNEL);
	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) {
		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 0;
		}
		rcu_assign_pointer(mpp_paths, newtbl);
		write_unlock(&pathtbl_resize_lock);

		synchronize_rcu();
		mesh_table_free(oldtbl, false);
	}
	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)
{
	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->dsn;
			spin_unlock_bh(&mpath->state_lock);
			mesh_path_error_tx(mpath->dst,
					cpu_to_le32(mpath->dsn),
					sdata->dev->broadcast, 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 succesful
 */
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:
	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)
{
	struct sk_buff *skb;

	while ((skb = skb_dequeue(&mpath->frame_queue)) &&
			(mpath->flags & MESH_PATH_ACTIVE))
		dev_queue_xmit(skb);
}

/**
 * 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 dsn = 0;

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

		da = hdr->addr3;
		ra = hdr->addr1;
		mpath = mesh_path_lookup(da, sdata);
		if (mpath)
			dsn = ++mpath->dsn;
		mesh_path_error_tx(skb->data, cpu_to_le32(dsn), 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->dsn = 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);
}
Commit	Line	Data
eb2b9311 LCC	1	/*
	2	* Copyright (c) 2008 open80211s Ltd.
	3	* Author: Luis Carlos Cobo <[email protected]>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*/
	9
	10	#include <linux/etherdevice.h>
	11	#include <linux/list.h>
eb2b9311 LCC	12	#include <linux/random.h>
	13	#include <linux/spinlock.h>
	14	#include <linux/string.h>
	15	#include <net/mac80211.h>
	16	#include "ieee80211_i.h"
	17	#include "mesh.h"
	18
	19	/* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */
	20	#define INIT_PATHS_SIZE_ORDER 2
	21
	22	/* Keep the mean chain length below this constant */
	23	#define MEAN_CHAIN_LEN 2
	24
	25	#define MPATH_EXPIRED(mpath) ((mpath->flags & MESH_PATH_ACTIVE) && \
	26	time_after(jiffies, mpath->exp_time) && \
	27	!(mpath->flags & MESH_PATH_FIXED))
	28
	29	struct mpath_node {
	30	struct hlist_node list;
	31	struct rcu_head rcu;
	32	/* This indirection allows two different tables to point to the same
	33	* mesh_path structure, useful when resizing
	34	*/
	35	struct mesh_path *mpath;
	36	};
	37
	38	static struct mesh_table *mesh_paths;
79617dee	39	static struct mesh_table mpp_paths; / Store paths for MPP&MAP */
eb2b9311 LCC	40
	41	/* This lock will have the grow table function as writer and add / delete nodes
	42	* as readers. When reading the table (i.e. doing lookups) we are well protected
	43	* by RCU
	44	*/
	45	static DEFINE_RWLOCK(pathtbl_resize_lock);
	46
	47	/**
	48	*
	49	* mesh_path_assign_nexthop - update mesh path next hop
	50	*
	51	* @mpath: mesh path to update
	52	* @sta: next hop to assign
	53	*
	54	* Locking: mpath->state_lock must be held when calling this function
	55	*/
	56	void mesh_path_assign_nexthop(struct mesh_path mpath, struct sta_info sta)
	57	{
10c836d7 JC	58	struct sk_buff *skb;
	59	struct ieee80211_hdr *hdr;
	60	struct sk_buff_head tmpq;
	61	unsigned long flags;
	62
d0709a65	63	rcu_assign_pointer(mpath->next_hop, sta);
10c836d7 JC	64
	65	__skb_queue_head_init(&tmpq);
	66
	67	spin_lock_irqsave(&mpath->frame_queue.lock, flags);
	68
	69	while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) {
	70	hdr = (struct ieee80211_hdr *) skb->data;
	71	memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
	72	__skb_queue_tail(&tmpq, skb);
	73	}
	74
	75	skb_queue_splice(&tmpq, &mpath->frame_queue);
	76	spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
eb2b9311 LCC	77	}
	78
	79
	80	/**
	81	* mesh_path_lookup - look up a path in the mesh path table
	82	* @dst: hardware address (ETH_ALEN length) of destination
f698d856	83	* @sdata: local subif
eb2b9311 LCC	84	*
	85	* Returns: pointer to the mesh path structure, or NULL if not found
	86	*
	87	* Locking: must be called within a read rcu section.
	88	*/
f698d856	89	struct mesh_path mesh_path_lookup(u8 dst, struct ieee80211_sub_if_data *sdata)
eb2b9311 LCC	90	{
	91	struct mesh_path *mpath;
	92	struct hlist_node *n;
	93	struct hlist_head *bucket;
	94	struct mesh_table *tbl;
	95	struct mpath_node *node;
	96
	97	tbl = rcu_dereference(mesh_paths);
	98
f698d856	99	bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
eb2b9311 LCC	100	hlist_for_each_entry_rcu(node, n, bucket, list) {
eb2b9311 LCC	101	mpath = node->mpath;
f698d856	102	if (mpath->sdata == sdata &&
eb2b9311 LCC	103	memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
	104	if (MPATH_EXPIRED(mpath)) {
	105	spin_lock_bh(&mpath->state_lock);
	106	if (MPATH_EXPIRED(mpath))
	107	mpath->flags &= ~MESH_PATH_ACTIVE;
	108	spin_unlock_bh(&mpath->state_lock);
	109	}
	110	return mpath;
	111	}
	112	}
	113	return NULL;
	114	}
	115
79617dee Y	116	struct mesh_path mpp_path_lookup(u8 dst, struct ieee80211_sub_if_data *sdata)
	117	{
	118	struct mesh_path *mpath;
	119	struct hlist_node *n;
	120	struct hlist_head *bucket;
	121	struct mesh_table *tbl;
	122	struct mpath_node *node;
	123
	124	tbl = rcu_dereference(mpp_paths);
	125
	126	bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
	127	hlist_for_each_entry_rcu(node, n, bucket, list) {
	128	mpath = node->mpath;
	129	if (mpath->sdata == sdata &&
	130	memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
	131	if (MPATH_EXPIRED(mpath)) {
	132	spin_lock_bh(&mpath->state_lock);
	133	if (MPATH_EXPIRED(mpath))
	134	mpath->flags &= ~MESH_PATH_ACTIVE;
	135	spin_unlock_bh(&mpath->state_lock);
	136	}
	137	return mpath;
	138	}
	139	}
	140	return NULL;
	141	}
	142
	143
eb2b9311 LCC	144	/**
	145	* mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
	146	* @idx: index
f698d856	147	* @sdata: local subif, or NULL for all entries
eb2b9311 LCC	148	*
	149	* Returns: pointer to the mesh path structure, or NULL if not found.
	150	*
	151	* Locking: must be called within a read rcu section.
	152	*/
f698d856	153	struct mesh_path mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data sdata)
eb2b9311 LCC	154	{
	155	struct mpath_node *node;
	156	struct hlist_node *p;
	157	int i;
	158	int j = 0;
	159
2a8ca29a	160	for_each_mesh_entry(mesh_paths, p, node, i) {
f698d856	161	if (sdata && node->mpath->sdata != sdata)
2a8ca29a	162	continue;
eb2b9311 LCC	163	if (j++ == idx) {
	164	if (MPATH_EXPIRED(node->mpath)) {
	165	spin_lock_bh(&node->mpath->state_lock);
	166	if (MPATH_EXPIRED(node->mpath))
	167	node->mpath->flags &= ~MESH_PATH_ACTIVE;
	168	spin_unlock_bh(&node->mpath->state_lock);
	169	}
	170	return node->mpath;
	171	}
2a8ca29a	172	}
eb2b9311 LCC	173
	174	return NULL;
	175	}
	176
	177	/**
	178	* mesh_path_add - allocate and add a new path to the mesh path table
	179	* @addr: destination address of the path (ETH_ALEN length)
f698d856	180	* @sdata: local subif
eb2b9311 LCC	181	*
	182	* Returns: 0 on sucess
	183	*
	184	* State: the initial state of the new path is set to 0
	185	*/
f698d856	186	int mesh_path_add(u8 dst, struct ieee80211_sub_if_data sdata)
eb2b9311	187	{
eb2b9311 LCC	188	struct mesh_path mpath, new_mpath;
	189	struct mpath_node node, new_node;
	190	struct hlist_head *bucket;
	191	struct hlist_node *n;
	192	int grow = 0;
	193	int err = 0;
	194	u32 hash_idx;
	195
e2e414d9 JB	196	might_sleep();
e2e414d9 JB	197
f698d856	198	if (memcmp(dst, sdata->dev->dev_addr, ETH_ALEN) == 0)
eb2b9311 LCC	199	/* never add ourselves as neighbours */
	200	return -ENOTSUPP;
	201
	202	if (is_multicast_ether_addr(dst))
	203	return -ENOTSUPP;
	204
472dbc45	205	if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
eb2b9311 LCC	206	return -ENOSPC;
eb2b9311 LCC	207
402d7752	208	err = -ENOMEM;
eb2b9311	209	new_mpath = kzalloc(sizeof(struct mesh_path), GFP_KERNEL);
402d7752 PE	210	if (!new_mpath)
	211	goto err_path_alloc;
	212
0eb03d5a	213	new_node = kmalloc(sizeof(struct mpath_node), GFP_KERNEL);
402d7752 PE	214	if (!new_node)
402d7752 PE	215	goto err_node_alloc;
f84e71a9 PE	216
f84e71a9 PE	217	read_lock(&pathtbl_resize_lock);
eb2b9311	218	memcpy(new_mpath->dst, dst, ETH_ALEN);
f698d856	219	new_mpath->sdata = sdata;
eb2b9311 LCC	220	new_mpath->flags = 0;
eb2b9311 LCC	221	skb_queue_head_init(&new_mpath->frame_queue);
eb2b9311 LCC	222	new_node->mpath = new_mpath;
	223	new_mpath->timer.data = (unsigned long) new_mpath;
	224	new_mpath->timer.function = mesh_path_timer;
	225	new_mpath->exp_time = jiffies;
	226	spin_lock_init(&new_mpath->state_lock);
	227	init_timer(&new_mpath->timer);
	228
f698d856	229	hash_idx = mesh_table_hash(dst, sdata, mesh_paths);
eb2b9311 LCC	230	bucket = &mesh_paths->hash_buckets[hash_idx];
	231
	232	spin_lock(&mesh_paths->hashwlock[hash_idx]);
	233
402d7752	234	err = -EEXIST;
eb2b9311 LCC	235	hlist_for_each_entry(node, n, bucket, list) {
eb2b9311 LCC	236	mpath = node->mpath;
f698d856	237	if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
402d7752	238	goto err_exists;
eb2b9311 LCC	239	}
	240
	241	hlist_add_head_rcu(&new_node->list, bucket);
	242	if (atomic_inc_return(&mesh_paths->entries) >=
	243	mesh_paths->mean_chain_len * (mesh_paths->hash_mask + 1))
	244	grow = 1;
	245
eb2b9311	246	spin_unlock(&mesh_paths->hashwlock[hash_idx]);
eb2b9311	247	read_unlock(&pathtbl_resize_lock);
402d7752	248	if (grow) {
eb2b9311 LCC	249	struct mesh_table oldtbl, newtbl;
	250
	251	write_lock(&pathtbl_resize_lock);
	252	oldtbl = mesh_paths;
	253	newtbl = mesh_table_grow(mesh_paths);
	254	if (!newtbl) {
	255	write_unlock(&pathtbl_resize_lock);
3282aea9	256	return 0;
eb2b9311 LCC	257	}
eb2b9311 LCC	258	rcu_assign_pointer(mesh_paths, newtbl);
6d6936e2 PE	259	write_unlock(&pathtbl_resize_lock);
6d6936e2 PE	260
eb2b9311 LCC	261	synchronize_rcu();
eb2b9311 LCC	262	mesh_table_free(oldtbl, false);
eb2b9311	263	}
402d7752 PE	264	return 0;
	265
	266	err_exists:
	267	spin_unlock(&mesh_paths->hashwlock[hash_idx]);
	268	read_unlock(&pathtbl_resize_lock);
	269	kfree(new_node);
	270	err_node_alloc:
	271	kfree(new_mpath);
	272	err_path_alloc:
472dbc45	273	atomic_dec(&sdata->u.mesh.mpaths);
eb2b9311 LCC	274	return err;
	275	}
	276
	277
79617dee Y	278	int mpp_path_add(u8 dst, u8 mpp, struct ieee80211_sub_if_data *sdata)
	279	{
	280	struct mesh_path mpath, new_mpath;
	281	struct mpath_node node, new_node;
	282	struct hlist_head *bucket;
	283	struct hlist_node *n;
	284	int grow = 0;
	285	int err = 0;
	286	u32 hash_idx;
	287
e2e414d9	288	might_sleep();
79617dee Y	289
	290	if (memcmp(dst, sdata->dev->dev_addr, ETH_ALEN) == 0)
	291	/* never add ourselves as neighbours */
	292	return -ENOTSUPP;
	293
	294	if (is_multicast_ether_addr(dst))
	295	return -ENOTSUPP;
	296
	297	err = -ENOMEM;
	298	new_mpath = kzalloc(sizeof(struct mesh_path), GFP_KERNEL);
	299	if (!new_mpath)
	300	goto err_path_alloc;
	301
	302	new_node = kmalloc(sizeof(struct mpath_node), GFP_KERNEL);
	303	if (!new_node)
	304	goto err_node_alloc;
	305
	306	read_lock(&pathtbl_resize_lock);
	307	memcpy(new_mpath->dst, dst, ETH_ALEN);
	308	memcpy(new_mpath->mpp, mpp, ETH_ALEN);
	309	new_mpath->sdata = sdata;
	310	new_mpath->flags = 0;
	311	skb_queue_head_init(&new_mpath->frame_queue);
	312	new_node->mpath = new_mpath;
	313	new_mpath->exp_time = jiffies;
	314	spin_lock_init(&new_mpath->state_lock);
	315
	316	hash_idx = mesh_table_hash(dst, sdata, mpp_paths);
	317	bucket = &mpp_paths->hash_buckets[hash_idx];
	318
	319	spin_lock(&mpp_paths->hashwlock[hash_idx]);
	320
	321	err = -EEXIST;
	322	hlist_for_each_entry(node, n, bucket, list) {
	323	mpath = node->mpath;
	324	if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0)
	325	goto err_exists;
	326	}
	327
	328	hlist_add_head_rcu(&new_node->list, bucket);
	329	if (atomic_inc_return(&mpp_paths->entries) >=
	330	mpp_paths->mean_chain_len * (mpp_paths->hash_mask + 1))
	331	grow = 1;
	332
	333	spin_unlock(&mpp_paths->hashwlock[hash_idx]);
	334	read_unlock(&pathtbl_resize_lock);
	335	if (grow) {
	336	struct mesh_table oldtbl, newtbl;
	337
	338	write_lock(&pathtbl_resize_lock);
	339	oldtbl = mpp_paths;
	340	newtbl = mesh_table_grow(mpp_paths);
	341	if (!newtbl) {
	342	write_unlock(&pathtbl_resize_lock);
	343	return 0;
	344	}
	345	rcu_assign_pointer(mpp_paths, newtbl);
	346	write_unlock(&pathtbl_resize_lock);
	347
	348	synchronize_rcu();
	349	mesh_table_free(oldtbl, false);
	350	}
	351	return 0;
	352
353	err_exists:
354	spin_unlock(&mpp_paths->hashwlock[hash_idx]);
355	read_unlock(&pathtbl_resize_lock);
356	kfree(new_node);
357	err_node_alloc:
358	kfree(new_mpath);
359	err_path_alloc:
360	return err;
361	}
362
363
eb2b9311 LCC	364	/**
	365	* mesh_plink_broken - deactivates paths and sends perr when a link breaks
	366	*
	367	* @sta: broken peer link
	368	*
	369	* This function must be called from the rate control algorithm if enough
	370	* delivery errors suggest that a peer link is no longer usable.
	371	*/
	372	void mesh_plink_broken(struct sta_info *sta)
	373	{
	374	struct mesh_path *mpath;
	375	struct mpath_node *node;
	376	struct hlist_node *p;
f698d856	377	struct ieee80211_sub_if_data *sdata = sta->sdata;
eb2b9311 LCC	378	int i;
	379
	380	rcu_read_lock();
	381	for_each_mesh_entry(mesh_paths, p, node, i) {
	382	mpath = node->mpath;
	383	spin_lock_bh(&mpath->state_lock);
	384	if (mpath->next_hop == sta &&
	385	mpath->flags & MESH_PATH_ACTIVE &&
	386	!(mpath->flags & MESH_PATH_FIXED)) {
	387	mpath->flags &= ~MESH_PATH_ACTIVE;
	388	++mpath->dsn;
	389	spin_unlock_bh(&mpath->state_lock);
	390	mesh_path_error_tx(mpath->dst,
	391	cpu_to_le32(mpath->dsn),
f698d856	392	sdata->dev->broadcast, sdata);
eb2b9311 LCC	393	} else
	394	spin_unlock_bh(&mpath->state_lock);
	395	}
	396	rcu_read_unlock();
	397	}
	398
	399	/**
	400	* mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
	401	*
	402	* @sta - mesh peer to match
	403	*
b4e08ea1 LCC	404	* RCU notes: this function is called when a mesh plink transitions from
	405	* PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that
	406	* allows path creation. This will happen before the sta can be freed (because
d0709a65 JB	407	* sta_info_destroy() calls this) so any reader in a rcu read block will be
d0709a65 JB	408	* protected against the plink disappearing.
eb2b9311 LCC	409	*/
	410	void mesh_path_flush_by_nexthop(struct sta_info *sta)
	411	{
	412	struct mesh_path *mpath;
	413	struct mpath_node *node;
	414	struct hlist_node *p;
	415	int i;
	416
	417	for_each_mesh_entry(mesh_paths, p, node, i) {
	418	mpath = node->mpath;
	419	if (mpath->next_hop == sta)
f698d856	420	mesh_path_del(mpath->dst, mpath->sdata);
eb2b9311 LCC	421	}
	422	}
	423
f698d856	424	void mesh_path_flush(struct ieee80211_sub_if_data *sdata)
eb2b9311 LCC	425	{
	426	struct mesh_path *mpath;
	427	struct mpath_node *node;
	428	struct hlist_node *p;
	429	int i;
	430
	431	for_each_mesh_entry(mesh_paths, p, node, i) {
	432	mpath = node->mpath;
f698d856 JBG	433	if (mpath->sdata == sdata)
f698d856 JBG	434	mesh_path_del(mpath->dst, mpath->sdata);
eb2b9311 LCC	435	}
	436	}
	437
	438	static void mesh_path_node_reclaim(struct rcu_head *rp)
	439	{
	440	struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
f698d856	441	struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
d0709a65	442
89a1ad69	443	del_timer_sync(&node->mpath->timer);
472dbc45	444	atomic_dec(&sdata->u.mesh.mpaths);
eb2b9311 LCC	445	kfree(node->mpath);
	446	kfree(node);
	447	}
	448
	449	/**
	450	* mesh_path_del - delete a mesh path from the table
	451	*
	452	* @addr: dst address (ETH_ALEN length)
f698d856	453	* @sdata: local subif
eb2b9311 LCC	454	*
eb2b9311 LCC	455	* Returns: 0 if succesful
eb2b9311	456	*/
f698d856	457	int mesh_path_del(u8 addr, struct ieee80211_sub_if_data sdata)
eb2b9311 LCC	458	{
	459	struct mesh_path *mpath;
	460	struct mpath_node *node;
	461	struct hlist_head *bucket;
	462	struct hlist_node *n;
	463	int hash_idx;
	464	int err = 0;
	465
	466	read_lock(&pathtbl_resize_lock);
f698d856	467	hash_idx = mesh_table_hash(addr, sdata, mesh_paths);
eb2b9311 LCC	468	bucket = &mesh_paths->hash_buckets[hash_idx];
	469
	470	spin_lock(&mesh_paths->hashwlock[hash_idx]);
	471	hlist_for_each_entry(node, n, bucket, list) {
	472	mpath = node->mpath;
f698d856	473	if (mpath->sdata == sdata &&
eb2b9311 LCC	474	memcmp(addr, mpath->dst, ETH_ALEN) == 0) {
eb2b9311 LCC	475	spin_lock_bh(&mpath->state_lock);
cfa22c71 LCC	476	mpath->flags \|= MESH_PATH_RESOLVING;
	477	hlist_del_rcu(&node->list);
	478	call_rcu(&node->rcu, mesh_path_node_reclaim);
	479	atomic_dec(&mesh_paths->entries);
eb2b9311 LCC	480	spin_unlock_bh(&mpath->state_lock);
	481	goto enddel;
	482	}
	483	}
	484
	485	err = -ENXIO;
	486	enddel:
	487	spin_unlock(&mesh_paths->hashwlock[hash_idx]);
	488	read_unlock(&pathtbl_resize_lock);
	489	return err;
	490	}
	491
	492	/**
	493	* mesh_path_tx_pending - sends pending frames in a mesh path queue
	494	*
	495	* @mpath: mesh path to activate
	496	*
	497	* Locking: the state_lock of the mpath structure must NOT be held when calling
	498	* this function.
	499	*/
	500	void mesh_path_tx_pending(struct mesh_path *mpath)
	501	{
	502	struct sk_buff *skb;
	503
	504	while ((skb = skb_dequeue(&mpath->frame_queue)) &&
	505	(mpath->flags & MESH_PATH_ACTIVE))
	506	dev_queue_xmit(skb);
	507	}
	508
	509	/**
	510	* mesh_path_discard_frame - discard a frame whose path could not be resolved
	511	*
	512	* @skb: frame to discard
f698d856	513	* @sdata: network subif the frame was to be sent through
eb2b9311	514	*
35946a57 JC	515	* If the frame was being forwarded from another MP, a PERR frame will be sent
	516	* to the precursor. The precursor's address (i.e. the previous hop) was saved
	517	* in addr1 of the frame-to-be-forwarded, and would only be overwritten once
	518	* the destination is successfully resolved.
eb2b9311 LCC	519	*
	520	* Locking: the function must me called within a rcu_read_lock region
	521	*/
f698d856 JBG	522	void mesh_path_discard_frame(struct sk_buff *skb,
f698d856 JBG	523	struct ieee80211_sub_if_data *sdata)
eb2b9311	524	{
e32f85f7	525	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
eb2b9311 LCC	526	struct mesh_path *mpath;
	527	u32 dsn = 0;
	528
f698d856	529	if (memcmp(hdr->addr4, sdata->dev->dev_addr, ETH_ALEN) != 0) {
eb2b9311 LCC	530	u8 ra, da;
eb2b9311 LCC	531
e32f85f7	532	da = hdr->addr3;
35946a57	533	ra = hdr->addr1;
f698d856	534	mpath = mesh_path_lookup(da, sdata);
eb2b9311 LCC	535	if (mpath)
eb2b9311 LCC	536	dsn = ++mpath->dsn;
f698d856	537	mesh_path_error_tx(skb->data, cpu_to_le32(dsn), ra, sdata);
eb2b9311 LCC	538	}
	539
	540	kfree_skb(skb);
472dbc45	541	sdata->u.mesh.mshstats.dropped_frames_no_route++;
eb2b9311 LCC	542	}
	543
	544	/**
	545	* mesh_path_flush_pending - free the pending queue of a mesh path
	546	*
	547	* @mpath: mesh path whose queue has to be freed
	548	*
	549	* Locking: the function must me called withing a rcu_read_lock region
	550	*/
	551	void mesh_path_flush_pending(struct mesh_path *mpath)
	552	{
eb2b9311 LCC	553	struct sk_buff *skb;
eb2b9311 LCC	554
eb2b9311 LCC	555	while ((skb = skb_dequeue(&mpath->frame_queue)) &&
eb2b9311 LCC	556	(mpath->flags & MESH_PATH_ACTIVE))
f698d856	557	mesh_path_discard_frame(skb, mpath->sdata);
eb2b9311 LCC	558	}
	559
	560	/**
	561	* mesh_path_fix_nexthop - force a specific next hop for a mesh path
	562	*
	563	* @mpath: the mesh path to modify
	564	* @next_hop: the next hop to force
	565	*
	566	* Locking: this function must be called holding mpath->state_lock
	567	*/
	568	void mesh_path_fix_nexthop(struct mesh_path mpath, struct sta_info next_hop)
	569	{
	570	spin_lock_bh(&mpath->state_lock);
	571	mesh_path_assign_nexthop(mpath, next_hop);
	572	mpath->dsn = 0xffff;
	573	mpath->metric = 0;
	574	mpath->hop_count = 0;
	575	mpath->exp_time = 0;
	576	mpath->flags \|= MESH_PATH_FIXED;
	577	mesh_path_activate(mpath);
	578	spin_unlock_bh(&mpath->state_lock);
	579	mesh_path_tx_pending(mpath);
	580	}
	581
	582	static void mesh_path_node_free(struct hlist_node *p, bool free_leafs)
	583	{
	584	struct mesh_path *mpath;
	585	struct mpath_node *node = hlist_entry(p, struct mpath_node, list);
	586	mpath = node->mpath;
	587	hlist_del_rcu(p);
eb2b9311 LCC	588	if (free_leafs)
	589	kfree(mpath);
	590	kfree(node);
	591	}
	592
4caf86c6	593	static int mesh_path_node_copy(struct hlist_node p, struct mesh_table newtbl)
eb2b9311 LCC	594	{
	595	struct mesh_path *mpath;
	596	struct mpath_node node, new_node;
	597	u32 hash_idx;
	598
8566dc3f	599	new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC);
00242c40 PE	600	if (new_node == NULL)
	601	return -ENOMEM;
	602
eb2b9311 LCC	603	node = hlist_entry(p, struct mpath_node, list);
eb2b9311 LCC	604	mpath = node->mpath;
eb2b9311	605	new_node->mpath = mpath;
f698d856	606	hash_idx = mesh_table_hash(mpath->dst, mpath->sdata, newtbl);
eb2b9311 LCC	607	hlist_add_head(&new_node->list,
eb2b9311 LCC	608	&newtbl->hash_buckets[hash_idx]);
4caf86c6	609	return 0;
eb2b9311 LCC	610	}
	611
	612	int mesh_pathtbl_init(void)
	613	{
	614	mesh_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
79617dee Y	615	if (!mesh_paths)
79617dee Y	616	return -ENOMEM;
eb2b9311 LCC	617	mesh_paths->free_node = &mesh_path_node_free;
	618	mesh_paths->copy_node = &mesh_path_node_copy;
	619	mesh_paths->mean_chain_len = MEAN_CHAIN_LEN;
79617dee Y	620
	621	mpp_paths = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
	622	if (!mpp_paths) {
	623	mesh_table_free(mesh_paths, true);
eb2b9311	624	return -ENOMEM;
79617dee Y	625	}
	626	mpp_paths->free_node = &mesh_path_node_free;
	627	mpp_paths->copy_node = &mesh_path_node_copy;
	628	mpp_paths->mean_chain_len = MEAN_CHAIN_LEN;
	629
eb2b9311 LCC	630	return 0;
	631	}
	632
f698d856	633	void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
eb2b9311 LCC	634	{
	635	struct mesh_path *mpath;
	636	struct mpath_node *node;
	637	struct hlist_node *p;
	638	int i;
	639
	640	read_lock(&pathtbl_resize_lock);
	641	for_each_mesh_entry(mesh_paths, p, node, i) {
f698d856	642	if (node->mpath->sdata != sdata)
eb2b9311 LCC	643	continue;
	644	mpath = node->mpath;
	645	spin_lock_bh(&mpath->state_lock);
	646	if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
	647	(!(mpath->flags & MESH_PATH_FIXED)) &&
	648	time_after(jiffies,
	649	mpath->exp_time + MESH_PATH_EXPIRE)) {
	650	spin_unlock_bh(&mpath->state_lock);
f698d856	651	mesh_path_del(mpath->dst, mpath->sdata);
eb2b9311 LCC	652	} else
	653	spin_unlock_bh(&mpath->state_lock);
	654	}
	655	read_unlock(&pathtbl_resize_lock);
	656	}
	657
	658	void mesh_pathtbl_unregister(void)
	659	{
	660	mesh_table_free(mesh_paths, true);
79617dee	661	mesh_table_free(mpp_paths, true);
eb2b9311	662	}