- 根目录:
- net
- mac80211
- mesh_pathtbl.c
/*
* 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 "wme.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
static inline bool mpath_expired(struct mesh_path *mpath)
{
return (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 __rcu *mesh_paths;
static struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */
int mesh_paths_generation;
/* This lock will have the grow table function as writer and add / delete nodes
* as readers. RCU provides sufficient protection only when reading the table
* (i.e. doing lookups). Adding or adding or removing nodes requires we take
* the read lock or we risk operating on an old table. The write lock is only
* needed when modifying the number of buckets a table.
*/
static DEFINE_RWLOCK(pathtbl_resize_lock);
static inline struct mesh_table *resize_dereference_mesh_paths(void)
{
return rcu_dereference_protected(mesh_paths,
lockdep_is_held(&pathtbl_resize_lock));
}
static inline struct mesh_table *resize_dereference_mpp_paths(void)
{
return rcu_dereference_protected(mpp_paths,
lockdep_is_held(&pathtbl_resize_lock));
}
/*
* CAREFUL -- "tbl" must not be an expression,
* in particular not an rcu_dereference(), since
* it's used twice. So it is illegal to do
* for_each_mesh_entry(rcu_dereference(...), ...)
*/
#define for_each_mesh_entry(tbl, node, i) \
for (i = 0; i <= tbl->hash_mask; i++) \
hlist_for_each_entry_rcu(node, &tbl->hash_buckets[i], list)
static struct mesh_table *mesh_table_alloc(int size_order)
{
int i;
struct mesh_table *newtbl;
newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
if (!newtbl)
return NULL;
newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
(1 << size_order), GFP_ATOMIC);
if (!newtbl->hash_buckets) {
kfree(newtbl);
return NULL;
}
newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
(1 << size_order), GFP_ATOMIC);
if (!newtbl->hashwlock) {
kfree(newtbl->hash_buckets);
kfree(newtbl);
return NULL;
}
newtbl->size_order = size_order;
newtbl->hash_mask = (1 << size_order) - 1;
atomic_set(&newtbl->entries, 0);
get_random_bytes(&newtbl->hash_rnd,
sizeof(newtbl->hash_rnd));
for (i = 0; i <= newtbl->hash_mask; i++)
spin_lock_init(&newtbl->hashwlock[i]);
spin_lock_init(&newtbl->gates_lock);
return newtbl;
}
static void __mesh_table_free(struct mesh_table *tbl)
{
kfree(tbl->hash_buckets);
kfree(tbl->hashwlock);
kfree(tbl);
}
static void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
{
struct hlist_head *mesh_hash;
struct hlist_node *p, *q;
struct mpath_node *gate;
int i;
mesh_hash = tbl->hash_buckets;
for (i = 0; i <= tbl->hash_mask; i++) {
spin_lock_bh(&tbl->hashwlock[i]);
hlist_for_each_safe(p, q, &mesh_hash[i]) {
tbl->free_node(p, free_leafs);
atomic_dec(&tbl->entries);
}
spin_unlock_bh(&tbl->hashwlock[i]);
}
if (free_leafs) {
spin_lock_bh(&tbl->gates_lock);
hlist_for_each_entry_safe(gate, q,
tbl->known_gates, list) {
hlist_del(&gate->list);
kfree(gate);
}
kfree(tbl->known_gates);
spin_unlock_bh(&tbl->gates_lock);
}
__mesh_table_free(tbl);
}
static int mesh_table_grow(struct mesh_table *oldtbl,
struct mesh_table *newtbl)
{
struct hlist_head *oldhash;
struct hlist_node *p, *q;
int i;
if (atomic_read(&oldtbl->entries)
< oldtbl->mean_chain_len * (oldtbl->hash_mask + 1))
return -EAGAIN;
newtbl->free_node = oldtbl->free_node;
newtbl->mean_chain_len = oldtbl->mean_chain_len;
newtbl->copy_node = oldtbl->copy_node;
newtbl->known_gates = oldtbl->known_gates;
atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries));
oldhash = oldtbl->hash_buckets;
for (i = 0; i <= oldtbl->hash_mask; i++)
hlist_for_each(p, &oldhash[i])
if (oldtbl->copy_node(p, newtbl) < 0)
goto errcopy;
return 0;
errcopy:
for (i = 0; i <= newtbl->hash_mask; i++) {
hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
oldtbl->free_node(p, 0);
}
return -ENOMEM;
}
static u32 mesh_table_hash(const u8 *addr, struct ieee80211_sub_if_data *sdata,
struct mesh_table *tbl)
{
/* Use last four bytes of hw addr and interface index as hash index */
return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex,
tbl->hash_rnd) & tbl->hash_mask;
}
/**
*
* 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;
unsigned long flags;
rcu_assign_pointer(mpath->next_hop, sta);
spin_lock_irqsave(&mpath->frame_queue.lock, flags);
skb_queue_walk(&mpath->frame_queue, skb) {
hdr = (struct ieee80211_hdr *) skb->data;
memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
ieee80211_mps_set_frame_flags(sta->sdata, sta, hdr);
}
spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
}
static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
struct mesh_path *gate_mpath)
{
struct ieee80211_hdr *hdr;
struct ieee80211s_hdr *mshdr;
int mesh_hdrlen, hdrlen;
char *next_hop;
hdr = (struct ieee80211_hdr *) skb->data;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
if (!(mshdr->flags & MESH_FLAGS_AE)) {
/* size of the fixed part of the mesh header */
mesh_hdrlen = 6;
/* make room for the two extended addresses */
skb_push(skb, 2 * ETH_ALEN);
memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
hdr = (struct ieee80211_hdr *) skb->data;
/* we preserve the previous mesh header and only add
* the new addreses */
mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
mshdr->flags = MESH_FLAGS_AE_A5_A6;
memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
}
/* update next hop */
hdr = (struct ieee80211_hdr *) skb->data;
rcu_read_lock();
next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
memcpy(hdr->addr1, next_hop, ETH_ALEN);
rcu_read_unlock();
memcpy(hdr->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN);
memcpy(hdr->addr3, dst_addr, ETH_ALEN);
}
/**
*
* mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
*
* This function is used to transfer or copy frames from an unresolved mpath to
* a gate mpath. The function also adds the Address Extension field and
* updates the next hop.
*
* If a frame already has an Address Extension field, only the next hop and
* destination addresses are updated.
*
* The gate mpath must be an active mpath with a valid mpath->next_hop.
*
* @mpath: An active mpath the frames will be sent to (i.e. the gate)
* @from_mpath: The failed mpath
* @copy: When true, copy all the frames to the new mpath queue. When false,
* move them.
*/
static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
struct mesh_path *from_mpath,
bool copy)
{
struct sk_buff *skb, *fskb, *tmp;
struct sk_buff_head failq;
unsigned long flags;
BUG_ON(gate_mpath == from_mpath);
BUG_ON(!gate_mpath->next_hop);
__skb_queue_head_init(&failq);
spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
skb_queue_splice_init(&from_mpath->frame_queue, &failq);
spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
skb_queue_walk_safe(&failq, fskb, tmp) {
if (skb_queue_len(&gate_mpath->frame_queue) >=
MESH_FRAME_QUEUE_LEN) {
mpath_dbg(gate_mpath->sdata, "mpath queue full!\n");
break;
}
skb = skb_copy(fskb, GFP_ATOMIC);
if (WARN_ON(!skb))
break;
prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
skb_queue_tail(&gate_mpath->frame_queue, skb);
if (copy)
continue;
__skb_unlink(fskb, &failq);
kfree_skb(fskb);
}
mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n",
gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue));
if (!copy)
return;
spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
skb_queue_splice(&failq, &from_mpath->frame_queue);
spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
}
static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst,
struct ieee80211_sub_if_data *sdata)
{
struct mesh_path *mpath;
struct hlist_head *bucket;
struct mpath_node *node;
bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
hlist_for_each_entry_rcu(node, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
ether_addr_equal(dst, mpath->dst)) {
if (mpath_expired(mpath)) {
spin_lock_bh(&mpath->state_lock);
mpath->flags &= ~MESH_PATH_ACTIVE;
spin_unlock_bh(&mpath->state_lock);
}
return mpath;
}
}
return NULL;
}
/**
* mesh_path_lookup - look up a path in the mesh path table
* @sdata: local subif
* @dst: hardware address (ETH_ALEN length) of destination
*
* 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(struct ieee80211_sub_if_data *sdata, const u8 *dst)
{
return mpath_lookup(rcu_dereference(mesh_paths), dst, sdata);
}
struct mesh_path *
mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
{
return mpath_lookup(rcu_dereference(mpp_paths), dst, sdata);
}
/**
* 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(struct ieee80211_sub_if_data *sdata, int idx)
{
struct mesh_table *tbl = rcu_dereference(mesh_paths);
struct mpath_node *node;
int i;
int j = 0;
for_each_mesh_entry(tbl, node, i) {
if (sdata && node->mpath->sdata != sdata)
continue;
if (j++ == idx) {
if (mpath_expired(node->mpath)) {
spin_lock_bh(&node->mpath->state_lock);
node->mpath->flags &= ~MESH_PATH_ACTIVE;
spin_unlock_bh(&node->mpath->state_lock);
}
return node->mpath;
}
}
return NULL;
}
/**
* mesh_path_add_gate - add the given mpath to a mesh gate to our path table
* @mpath: gate path to add to table
*/
int mesh_path_add_gate(struct mesh_path *mpath)
{
struct mesh_table *tbl;
struct mpath_node *gate, *new_gate;
int err;
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
hlist_for_each_entry_rcu(gate, tbl->known_gates, list)
if (gate->mpath == mpath) {
err = -EEXIST;
goto err_rcu;
}
new_gate = kzalloc(sizeof(struct mpath_node), GFP_ATOMIC);
if (!new_gate) {
err = -ENOMEM;
goto err_rcu;
}
mpath->is_gate = true;
mpath->sdata->u.mesh.num_gates++;
new_gate->mpath = mpath;
spin_lock_bh(&tbl->gates_lock);
hlist_add_head_rcu(&new_gate->list, tbl->known_gates);
spin_unlock_bh(&tbl->gates_lock);
mpath_dbg(mpath->sdata,
"Mesh path: Recorded new gate: %pM. %d known gates\n",
mpath->dst, mpath->sdata->u.mesh.num_gates);
err = 0;
err_rcu:
rcu_read_unlock();
return err;
}
/**
* mesh_gate_del - remove a mesh gate from the list of known gates
* @tbl: table which holds our list of known gates
* @mpath: gate mpath
*
* Locking: must be called inside rcu_read_lock() section
*/
static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
{
struct mpath_node *gate;
struct hlist_node *q;
hlist_for_each_entry_safe(gate, q, tbl->known_gates, list) {
if (gate->mpath != mpath)
continue;
spin_lock_bh(&tbl->gates_lock);
hlist_del_rcu(&gate->list);
kfree_rcu(gate, rcu);
spin_unlock_bh(&tbl->gates_lock);
mpath->sdata->u.mesh.num_gates--;
mpath->is_gate = false;
mpath_dbg(mpath->sdata,
"Mesh path: Deleted gate: %pM. %d known gates\n",
mpath->dst, mpath->sdata->u.mesh.num_gates);
break;
}
}
/**
* mesh_gate_num - number of gates known to this interface
* @sdata: subif data
*/
int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
{
return sdata->u.mesh.num_gates;
}
/**
* mesh_path_add - allocate and add a new path to the mesh path table
* @dst: 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
*/
struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata,
const u8 *dst)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
struct mesh_table *tbl;
struct mesh_path *mpath, *new_mpath;
struct mpath_node *node, *new_node;
struct hlist_head *bucket;
int grow = 0;
int err;
u32 hash_idx;
if (ether_addr_equal(dst, sdata->vif.addr))
/* never add ourselves as neighbours */
return ERR_PTR(-ENOTSUPP);
if (is_multicast_ether_addr(dst))
return ERR_PTR(-ENOTSUPP);
if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0)
return ERR_PTR(-ENOSPC);
read_lock_bh(&pathtbl_resize_lock);
tbl = resize_dereference_mesh_paths();
hash_idx = mesh_table_hash(dst, sdata, tbl);
bucket = &tbl->hash_buckets[hash_idx];
spin_lock(&tbl->hashwlock[hash_idx]);
hlist_for_each_entry(node, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
ether_addr_equal(dst, mpath->dst))
goto found;
}
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;
memcpy(new_mpath->dst, dst, ETH_ALEN);
eth_broadcast_addr(new_mpath->rann_snd_addr);
new_mpath->is_root = false;
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);
hlist_add_head_rcu(&new_node->list, bucket);
if (atomic_inc_return(&tbl->entries) >=
tbl->mean_chain_len * (tbl->hash_mask + 1))
grow = 1;
mesh_paths_generation++;
if (grow) {
set_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags);
ieee80211_queue_work(&local->hw, &sdata->work);
}
mpath = new_mpath;
found:
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
return mpath;
err_node_alloc:
kfree(new_mpath);
err_path_alloc:
atomic_dec(&sdata->u.mesh.mpaths);
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&pathtbl_resize_lock);
return ERR_PTR(err);
}
static void mesh_table_free_rcu(struct rcu_head *rcu)
{
struct mesh_table *tbl = container_of(rcu, struct mesh_table, rcu_head);
mesh_table_free(tbl, false);
}
void mesh_mpath_table_grow(void)
{
struct mesh_table *oldtbl, *newtbl;
write_lock_bh(&pathtbl_resize_lock);
oldtbl = resize_dereference_mesh_paths();
newtbl = mesh_table_alloc(oldtbl->size_order + 1);
if (!newtbl)
goto out;
if (mesh_table_grow(oldtbl, newtbl) < 0) {
__mesh_table_free(newtbl);
goto out;
}
rcu_assign_pointer(mesh_paths, newtbl);
call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
out:
write_unlock_bh(&pathtbl_resize_lock);
}
void mesh_mpp_table_grow(void)
{
struct mesh_table *oldtbl, *newtbl;
write_lock_bh(&pathtbl_resize_lock);
oldtbl = resize_dereference_mpp_paths();
newtbl = mesh_table_alloc(oldtbl->size_order + 1);
if (!newtbl)
goto out;
if (mesh_table_grow(oldtbl, newtbl) < 0) {
__mesh_table_free(newtbl);
goto out;
}
rcu_assign_pointer(mpp_paths, newtbl);
call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu);
out:
write_unlock_bh(&pathtbl_resize_lock);
}
int mpp_path_add(struct ieee80211_sub_if_data *sdata,
const u8 *dst, const u8 *mpp)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
struct mesh_table *tbl;
struct mesh_path *mpath, *new_mpath;
struct mpath_node *node, *new_node;
struct hlist_head *bucket;
int grow = 0;
int err = 0;
u32 hash_idx;
if (ether_addr_equal(dst, sdata->vif.addr))
/* 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_bh(&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;
init_timer(&new_mpath->timer);
new_mpath->exp_time = jiffies;
spin_lock_init(&new_mpath->state_lock);
tbl = resize_dereference_mpp_paths();
hash_idx = mesh_table_hash(dst, sdata, tbl);
bucket = &tbl->hash_buckets[hash_idx];
spin_lock(&tbl->hashwlock[hash_idx]);
err = -EEXIST;
hlist_for_each_entry(node, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
ether_addr_equal(dst, mpath->dst))
goto err_exists;
}
hlist_add_head_rcu(&new_node->list, bucket);
if (atomic_inc_return(&tbl->entries) >=
tbl->mean_chain_len * (tbl->hash_mask + 1))
grow = 1;
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&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(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&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_table *tbl;
static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
struct mesh_path *mpath;
struct mpath_node *node;
struct ieee80211_sub_if_data *sdata = sta->sdata;
int i;
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
for_each_mesh_entry(tbl, node, i) {
mpath = node->mpath;
if (rcu_dereference(mpath->next_hop) == sta &&
mpath->flags & MESH_PATH_ACTIVE &&
!(mpath->flags & MESH_PATH_FIXED)) {
spin_lock_bh(&mpath->state_lock);
mpath->flags &= ~MESH_PATH_ACTIVE;
++mpath->sn;
spin_unlock_bh(&mpath->state_lock);
mesh_path_error_tx(sdata,
sdata->u.mesh.mshcfg.element_ttl,
mpath->dst, mpath->sn,
WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast);
}
}
rcu_read_unlock();
}
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);
}
/* needs to be called with the corresponding hashwlock taken */
static void __mesh_path_del(struct mesh_table *tbl, struct mpath_node *node)
{
struct mesh_path *mpath;
mpath = node->mpath;
spin_lock(&mpath->state_lock);
mpath->flags |= MESH_PATH_RESOLVING;
if (mpath->is_gate)
mesh_gate_del(tbl, mpath);
hlist_del_rcu(&node->list);
call_rcu(&node->rcu, mesh_path_node_reclaim);
spin_unlock(&mpath->state_lock);
atomic_dec(&tbl->entries);
}
/**
* 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_table *tbl;
struct mesh_path *mpath;
struct mpath_node *node;
int i;
rcu_read_lock();
read_lock_bh(&pathtbl_resize_lock);
tbl = resize_dereference_mesh_paths();
for_each_mesh_entry(tbl, node, i) {
mpath = node->mpath;
if (rcu_dereference(mpath->next_hop) == sta) {
spin_lock(&tbl->hashwlock[i]);
__mesh_path_del(tbl, node);
spin_unlock(&tbl->hashwlock[i]);
}
}
read_unlock_bh(&pathtbl_resize_lock);
rcu_read_unlock();
}
static void table_flush_by_iface(struct mesh_table *tbl,
struct ieee80211_sub_if_data *sdata)
{
struct mesh_path *mpath;
struct mpath_node *node;
int i;
WARN_ON(!rcu_read_lock_held());
for_each_mesh_entry(tbl, node, i) {
mpath = node->mpath;
if (mpath->sdata != sdata)
continue;
spin_lock_bh(&tbl->hashwlock[i]);
__mesh_path_del(tbl, node);
spin_unlock_bh(&tbl->hashwlock[i]);
}
}
/**
* mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
*
* This function deletes both mesh paths as well as mesh portal paths.
*
* @sdata: interface data to match
*
*/
void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
{
struct mesh_table *tbl;
rcu_read_lock();
read_lock_bh(&pathtbl_resize_lock);
tbl = resize_dereference_mesh_paths();
table_flush_by_iface(tbl, sdata);
tbl = resize_dereference_mpp_paths();
table_flush_by_iface(tbl, sdata);
read_unlock_bh(&pathtbl_resize_lock);
rcu_read_unlock();
}
/**
* 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(struct ieee80211_sub_if_data *sdata, const u8 *addr)
{
struct mesh_table *tbl;
struct mesh_path *mpath;
struct mpath_node *node;
struct hlist_head *bucket;
int hash_idx;
int err = 0;
read_lock_bh(&pathtbl_resize_lock);
tbl = resize_dereference_mesh_paths();
hash_idx = mesh_table_hash(addr, sdata, tbl);
bucket = &tbl->hash_buckets[hash_idx];
spin_lock(&tbl->hashwlock[hash_idx]);
hlist_for_each_entry(node, bucket, list) {
mpath = node->mpath;
if (mpath->sdata == sdata &&
ether_addr_equal(addr, mpath->dst)) {
__mesh_path_del(tbl, node);
goto enddel;
}
}
err = -ENXIO;
enddel:
mesh_paths_generation++;
spin_unlock(&tbl->hashwlock[hash_idx]);
read_unlock_bh(&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_send_to_gates - sends pending frames to all known mesh gates
*
* @mpath: mesh path whose queue will be emptied
*
* If there is only one gate, the frames are transferred from the failed mpath
* queue to that gate's queue. If there are more than one gates, the frames
* are copied from each gate to the next. After frames are copied, the
* mpath queues are emptied onto the transmission queue.
*/
int mesh_path_send_to_gates(struct mesh_path *mpath)
{
struct ieee80211_sub_if_data *sdata = mpath->sdata;
struct mesh_table *tbl;
struct mesh_path *from_mpath = mpath;
struct mpath_node *gate = NULL;
bool copy = false;
struct hlist_head *known_gates;
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
known_gates = tbl->known_gates;
rcu_read_unlock();
if (!known_gates)
return -EHOSTUNREACH;
hlist_for_each_entry_rcu(gate, known_gates, list) {
if (gate->mpath->sdata != sdata)
continue;
if (gate->mpath->flags & MESH_PATH_ACTIVE) {
mpath_dbg(sdata, "Forwarding to %pM\n", gate->mpath->dst);
mesh_path_move_to_queue(gate->mpath, from_mpath, copy);
from_mpath = gate->mpath;
copy = true;
} else {
mpath_dbg(sdata,
"Not forwarding %p (flags %#x)\n",
gate->mpath, gate->mpath->flags);
}
}
hlist_for_each_entry_rcu(gate, known_gates, list)
if (gate->mpath->sdata == sdata) {
mpath_dbg(sdata, "Sending to %pM\n", gate->mpath->dst);
mesh_path_tx_pending(gate->mpath);
}
return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
}
/**
* 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
*
* Locking: the function must me called within a rcu_read_lock region
*/
void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
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 within 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)) != NULL)
mesh_path_discard_frame(mpath->sdata, skb);
}
/**
* 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) {
del_timer_sync(&mpath->timer);
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)
{
struct mesh_table *tbl_path, *tbl_mpp;
int ret;
tbl_path = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
if (!tbl_path)
return -ENOMEM;
tbl_path->free_node = &mesh_path_node_free;
tbl_path->copy_node = &mesh_path_node_copy;
tbl_path->mean_chain_len = MEAN_CHAIN_LEN;
tbl_path->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
if (!tbl_path->known_gates) {
ret = -ENOMEM;
goto free_path;
}
INIT_HLIST_HEAD(tbl_path->known_gates);
tbl_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
if (!tbl_mpp) {
ret = -ENOMEM;
goto free_path;
}
tbl_mpp->free_node = &mesh_path_node_free;
tbl_mpp->copy_node = &mesh_path_node_copy;
tbl_mpp->mean_chain_len = MEAN_CHAIN_LEN;
tbl_mpp->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
if (!tbl_mpp->known_gates) {
ret = -ENOMEM;
goto free_mpp;
}
INIT_HLIST_HEAD(tbl_mpp->known_gates);
/* Need no locking since this is during init */
RCU_INIT_POINTER(mesh_paths, tbl_path);
RCU_INIT_POINTER(mpp_paths, tbl_mpp);
return 0;
free_mpp:
mesh_table_free(tbl_mpp, true);
free_path:
mesh_table_free(tbl_path, true);
return ret;
}
void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
{
struct mesh_table *tbl;
struct mesh_path *mpath;
struct mpath_node *node;
int i;
rcu_read_lock();
tbl = rcu_dereference(mesh_paths);
for_each_mesh_entry(tbl, node, i) {
if (node->mpath->sdata != sdata)
continue;
mpath = node->mpath;
if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
(!(mpath->flags & MESH_PATH_FIXED)) &&
time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
mesh_path_del(mpath->sdata, mpath->dst);
}
rcu_read_unlock();
}
void mesh_pathtbl_unregister(void)
{
/* no need for locking during exit path */
mesh_table_free(rcu_dereference_protected(mesh_paths, 1), true);
mesh_table_free(rcu_dereference_protected(mpp_paths, 1), true);
}