blob: 54d44836dd2831d4278ef8a53c59e03eac205141 [file] [log] [blame]
/*
* 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"
static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath);
static u32 mesh_table_hash(const void *addr, u32 len, u32 seed)
{
/* Use last four bytes of hw addr as hash index */
return jhash_1word(__get_unaligned_cpu32((u8 *)addr + 2), seed);
}
static const struct rhashtable_params mesh_rht_params = {
.nelem_hint = 2,
.automatic_shrinking = true,
.key_len = ETH_ALEN,
.key_offset = offsetof(struct mesh_path, dst),
.head_offset = offsetof(struct mesh_path, rhash),
.hashfn = mesh_table_hash,
};
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);
}
static void mesh_path_rht_free(void *ptr, void *tblptr)
{
struct mesh_path *mpath = ptr;
struct mesh_table *tbl = tblptr;
mesh_path_free_rcu(tbl, mpath);
}
static struct mesh_table *mesh_table_alloc(void)
{
struct mesh_table *newtbl;
newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC);
if (!newtbl)
return NULL;
INIT_HLIST_HEAD(&newtbl->known_gates);
atomic_set(&newtbl->entries, 0);
spin_lock_init(&newtbl->gates_lock);
rhashtable_init(&newtbl->rhead, &mesh_rht_params);
return newtbl;
}
static void mesh_table_free(struct mesh_table *tbl)
{
rhashtable_free_and_destroy(&tbl->rhead,
mesh_path_rht_free, tbl);
kfree(tbl);
}
/**
*
* 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;
if (WARN_ON(gate_mpath == from_mpath))
return;
if (WARN_ON(!gate_mpath->next_hop))
return;
__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;
mpath = rhashtable_lookup_fast(&tbl->rhead, dst, mesh_rht_params);
if (mpath && mpath_expired(mpath)) {
spin_lock_bh(&mpath->state_lock);
mpath->flags &= ~MESH_PATH_ACTIVE;
spin_unlock_bh(&mpath->state_lock);
}
return mpath;
}
/**
* 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(sdata->u.mesh.mesh_paths, dst, sdata);
}
struct mesh_path *
mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst)
{
return mpath_lookup(sdata->u.mesh.mpp_paths, dst, sdata);
}
static struct mesh_path *
__mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx)
{
int i = 0, ret;
struct mesh_path *mpath = NULL;
struct rhashtable_iter iter;
ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
if (ret)
return NULL;
ret = rhashtable_walk_start(&iter);
if (ret && ret != -EAGAIN)
goto err;
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
continue;
if (IS_ERR(mpath))
break;
if (i++ == idx)
break;
}
err:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
if (IS_ERR(mpath) || !mpath)
return NULL;
if (mpath_expired(mpath)) {
spin_lock_bh(&mpath->state_lock);
mpath->flags &= ~MESH_PATH_ACTIVE;
spin_unlock_bh(&mpath->state_lock);
}
return mpath;
}
/**
* 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)
{
return __mesh_path_lookup_by_idx(sdata->u.mesh.mesh_paths, idx);
}
/**
* mpp_path_lookup_by_idx - look up a path in the proxy path table by its index
* @idx: index
* @sdata: local subif, or NULL for all entries
*
* Returns: pointer to the proxy path structure, or NULL if not found.
*
* Locking: must be called within a read rcu section.
*/
struct mesh_path *
mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx)
{
return __mesh_path_lookup_by_idx(sdata->u.mesh.mpp_paths, idx);
}
/**
* 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;
int err;
rcu_read_lock();
tbl = mpath->sdata->u.mesh.mesh_paths;
spin_lock_bh(&mpath->state_lock);
if (mpath->is_gate) {
err = -EEXIST;
spin_unlock_bh(&mpath->state_lock);
goto err_rcu;
}
mpath->is_gate = true;
mpath->sdata->u.mesh.num_gates++;
spin_lock(&tbl->gates_lock);
hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates);
spin_unlock(&tbl->gates_lock);
spin_unlock_bh(&mpath->state_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
*/
static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
{
lockdep_assert_held(&mpath->state_lock);
if (!mpath->is_gate)
return;
mpath->is_gate = false;
spin_lock_bh(&tbl->gates_lock);
hlist_del_rcu(&mpath->gate_list);
mpath->sdata->u.mesh.num_gates--;
spin_unlock_bh(&tbl->gates_lock);
mpath_dbg(mpath->sdata,
"Mesh path: Deleted gate: %pM. %d known gates\n",
mpath->dst, mpath->sdata->u.mesh.num_gates);
}
/**
* 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;
}
static
struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata,
const u8 *dst, gfp_t gfp_flags)
{
struct mesh_path *new_mpath;
new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags);
if (!new_mpath)
return NULL;
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_mpath->exp_time = jiffies;
spin_lock_init(&new_mpath->state_lock);
setup_timer(&new_mpath->timer, mesh_path_timer,
(unsigned long) new_mpath);
return new_mpath;
}
/**
* 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 mesh_table *tbl;
struct mesh_path *mpath, *new_mpath;
int ret;
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);
new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
if (!new_mpath)
return ERR_PTR(-ENOMEM);
tbl = sdata->u.mesh.mesh_paths;
do {
ret = rhashtable_lookup_insert_fast(&tbl->rhead,
&new_mpath->rhash,
mesh_rht_params);
if (ret == -EEXIST)
mpath = rhashtable_lookup_fast(&tbl->rhead,
dst,
mesh_rht_params);
} while (unlikely(ret == -EEXIST && !mpath));
if (ret) {
kfree(new_mpath);
if (ret != -EEXIST)
return ERR_PTR(ret);
new_mpath = mpath;
}
sdata->u.mesh.mesh_paths_generation++;
return new_mpath;
}
int mpp_path_add(struct ieee80211_sub_if_data *sdata,
const u8 *dst, const u8 *mpp)
{
struct mesh_table *tbl;
struct mesh_path *new_mpath;
int ret;
if (ether_addr_equal(dst, sdata->vif.addr))
/* never add ourselves as neighbours */
return -ENOTSUPP;
if (is_multicast_ether_addr(dst))
return -ENOTSUPP;
new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC);
if (!new_mpath)
return -ENOMEM;
memcpy(new_mpath->mpp, mpp, ETH_ALEN);
tbl = sdata->u.mesh.mpp_paths;
ret = rhashtable_lookup_insert_fast(&tbl->rhead,
&new_mpath->rhash,
mesh_rht_params);
if (ret)
kfree(new_mpath);
sdata->u.mesh.mpp_paths_generation++;
return ret;
}
/**
* 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 ieee80211_sub_if_data *sdata = sta->sdata;
struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
struct mesh_path *mpath;
struct rhashtable_iter iter;
int ret;
ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
if (ret)
return;
ret = rhashtable_walk_start(&iter);
if (ret && ret != -EAGAIN)
goto out;
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
continue;
if (IS_ERR(mpath))
break;
if (rcu_access_pointer(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);
}
}
out:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
static void mesh_path_free_rcu(struct mesh_table *tbl,
struct mesh_path *mpath)
{
struct ieee80211_sub_if_data *sdata = mpath->sdata;
spin_lock_bh(&mpath->state_lock);
mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED;
mesh_gate_del(tbl, mpath);
spin_unlock_bh(&mpath->state_lock);
del_timer_sync(&mpath->timer);
atomic_dec(&sdata->u.mesh.mpaths);
atomic_dec(&tbl->entries);
mesh_path_flush_pending(mpath);
kfree_rcu(mpath, rcu);
}
static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath)
{
rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
mesh_path_free_rcu(tbl, mpath);
}
/**
* 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 ieee80211_sub_if_data *sdata = sta->sdata;
struct mesh_table *tbl = sdata->u.mesh.mesh_paths;
struct mesh_path *mpath;
struct rhashtable_iter iter;
int ret;
ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
if (ret)
return;
ret = rhashtable_walk_start(&iter);
if (ret && ret != -EAGAIN)
goto out;
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
continue;
if (IS_ERR(mpath))
break;
if (rcu_access_pointer(mpath->next_hop) == sta)
__mesh_path_del(tbl, mpath);
}
out:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata,
const u8 *proxy)
{
struct mesh_table *tbl = sdata->u.mesh.mpp_paths;
struct mesh_path *mpath;
struct rhashtable_iter iter;
int ret;
ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
if (ret)
return;
ret = rhashtable_walk_start(&iter);
if (ret && ret != -EAGAIN)
goto out;
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
continue;
if (IS_ERR(mpath))
break;
if (ether_addr_equal(mpath->mpp, proxy))
__mesh_path_del(tbl, mpath);
}
out:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
static void table_flush_by_iface(struct mesh_table *tbl)
{
struct mesh_path *mpath;
struct rhashtable_iter iter;
int ret;
ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_ATOMIC);
if (ret)
return;
ret = rhashtable_walk_start(&iter);
if (ret && ret != -EAGAIN)
goto out;
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
continue;
if (IS_ERR(mpath))
break;
__mesh_path_del(tbl, mpath);
}
out:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
/**
* 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)
{
table_flush_by_iface(sdata->u.mesh.mesh_paths);
table_flush_by_iface(sdata->u.mesh.mpp_paths);
}
/**
* table_path_del - delete a path from the mesh or mpp table
*
* @tbl: mesh or mpp path table
* @sdata: local subif
* @addr: dst address (ETH_ALEN length)
*
* Returns: 0 if successful
*/
static int table_path_del(struct mesh_table *tbl,
struct ieee80211_sub_if_data *sdata,
const u8 *addr)
{
struct mesh_path *mpath;
rcu_read_lock();
mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
if (!mpath) {
rcu_read_unlock();
return -ENXIO;
}
__mesh_path_del(tbl, mpath);
rcu_read_unlock();
return 0;
}
/**
* 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)
{
int err;
/* flush relevant mpp entries first */
mpp_flush_by_proxy(sdata, addr);
err = table_path_del(sdata->u.mesh.mesh_paths, sdata, addr);
sdata->u.mesh.mesh_paths_generation++;
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 mesh_path *gate;
bool copy = false;
tbl = sdata->u.mesh.mesh_paths;
rcu_read_lock();
hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
if (gate->flags & MESH_PATH_ACTIVE) {
mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst);
mesh_path_move_to_queue(gate, from_mpath, copy);
from_mpath = gate;
copy = true;
} else {
mpath_dbg(sdata,
"Not forwarding to %pM (flags %#x)\n",
gate->dst, gate->flags);
}
}
hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) {
mpath_dbg(sdata, "Sending to %pM\n", gate->dst);
mesh_path_tx_pending(gate);
}
rcu_read_unlock();
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_SN_VALID;
mesh_path_activate(mpath);
spin_unlock_bh(&mpath->state_lock);
ewma_mesh_fail_avg_init(&next_hop->mesh->fail_avg);
/* init it at a low value - 0 start is tricky */
ewma_mesh_fail_avg_add(&next_hop->mesh->fail_avg, 1);
mesh_path_tx_pending(mpath);
}
int mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
{
struct mesh_table *tbl_path, *tbl_mpp;
int ret;
tbl_path = mesh_table_alloc();
if (!tbl_path)
return -ENOMEM;
tbl_mpp = mesh_table_alloc();
if (!tbl_mpp) {
ret = -ENOMEM;
goto free_path;
}
sdata->u.mesh.mesh_paths = tbl_path;
sdata->u.mesh.mpp_paths = tbl_mpp;
return 0;
free_path:
mesh_table_free(tbl_path);
return ret;
}
static
void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
struct mesh_table *tbl)
{
struct mesh_path *mpath;
struct rhashtable_iter iter;
int ret;
ret = rhashtable_walk_init(&tbl->rhead, &iter, GFP_KERNEL);
if (ret)
return;
ret = rhashtable_walk_start(&iter);
if (ret && ret != -EAGAIN)
goto out;
while ((mpath = rhashtable_walk_next(&iter))) {
if (IS_ERR(mpath) && PTR_ERR(mpath) == -EAGAIN)
continue;
if (IS_ERR(mpath))
break;
if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
(!(mpath->flags & MESH_PATH_FIXED)) &&
time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
__mesh_path_del(tbl, mpath);
}
out:
rhashtable_walk_stop(&iter);
rhashtable_walk_exit(&iter);
}
void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
{
mesh_path_tbl_expire(sdata, sdata->u.mesh.mesh_paths);
mesh_path_tbl_expire(sdata, sdata->u.mesh.mpp_paths);
}
void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata)
{
mesh_table_free(sdata->u.mesh.mesh_paths);
mesh_table_free(sdata->u.mesh.mpp_paths);
}