// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2008, 2009 open80211s Ltd.
* Copyright (C) 2023 Intel Corporation
* Author: Luis Carlos Cobo <[email protected]>
*/
#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"
#include <linux/rhashtable.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 const struct rhashtable_params fast_tx_rht_params = {
.nelem_hint = 10,
.automatic_shrinking = true,
.key_len = sizeof_field(struct ieee80211_mesh_fast_tx, key),
.key_offset = offsetof(struct ieee80211_mesh_fast_tx, key),
.head_offset = offsetof(struct ieee80211_mesh_fast_tx, rhash),
.hashfn = mesh_table_hash,
};
static void __mesh_fast_tx_entry_free(void *ptr, void *tblptr)
{
struct ieee80211_mesh_fast_tx *entry = ptr;
kfree_rcu(entry, fast_tx.rcu_head);
}
static void mesh_fast_tx_deinit(struct ieee80211_sub_if_data *sdata)
{
struct mesh_tx_cache *cache;
cache = &sdata->u.mesh.tx_cache;
rhashtable_free_and_destroy(&cache->rht,
__mesh_fast_tx_entry_free, NULL);
}
static void mesh_fast_tx_init(struct ieee80211_sub_if_data *sdata)
{
struct mesh_tx_cache *cache;
cache = &sdata->u.mesh.tx_cache;
rhashtable_init(&cache->rht, &fast_tx_rht_params);
INIT_HLIST_HEAD(&cache->walk_head);
spin_lock_init(&cache->walk_lock);
}
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 void mesh_table_init(struct mesh_table *tbl)
{
INIT_HLIST_HEAD(&tbl->known_gates);
INIT_HLIST_HEAD(&tbl->walk_head);
atomic_set(&tbl->entries, 0);
spin_lock_init(&tbl->gates_lock);
spin_lock_init(&tbl->walk_lock);
/* rhashtable_init() may fail only in case of wrong
* mesh_rht_params
*/
WARN_ON(rhashtable_init(&tbl->rhead, &mesh_rht_params));
}
static void mesh_table_free(struct mesh_table *tbl)
{
rhashtable_free_and_destroy(&tbl->rhead,
mesh_path_rht_free, 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 addresses */
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
*
* @gate_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.
*
* 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.
*/
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(&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;
struct mesh_path *mpath;
hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
if (i++ == idx)
break;
}
if (!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
*
* Returns: 0 on success, -EEXIST
*/
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
*
* Returns: The number of gates
*/
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);
timer_setup(&new_mpath->timer, mesh_path_timer, 0);
return new_mpath;
}
static void mesh_fast_tx_entry_free(struct mesh_tx_cache *cache,
struct ieee80211_mesh_fast_tx *entry)
{
hlist_del_rcu(&entry->walk_list);
rhashtable_remove_fast(&cache->rht, &entry->rhash, fast_tx_rht_params);
kfree_rcu(entry, fast_tx.rcu_head);
}
struct ieee80211_mesh_fast_tx *
mesh_fast_tx_get(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mesh_fast_tx_key *key)
{
struct ieee80211_mesh_fast_tx *entry;
struct mesh_tx_cache *cache;
cache = &sdata->u.mesh.tx_cache;
entry = rhashtable_lookup(&cache->rht, key, fast_tx_rht_params);
if (!entry)
return NULL;
if (!(entry->mpath->flags & MESH_PATH_ACTIVE) ||
mpath_expired(entry->mpath)) {
spin_lock_bh(&cache->walk_lock);
entry = rhashtable_lookup(&cache->rht, key, fast_tx_rht_params);
if (entry)
mesh_fast_tx_entry_free(cache, entry);
spin_unlock_bh(&cache->walk_lock);
return NULL;
}
mesh_path_refresh(sdata, entry->mpath, NULL);
if (entry->mppath)
entry->mppath->exp_time = jiffies;
entry->timestamp = jiffies;
return entry;
}
void mesh_fast_tx_cache(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb, struct mesh_path *mpath)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_mesh_fast_tx *entry, *prev;
struct ieee80211_mesh_fast_tx build = {};
struct ieee80211s_hdr *meshhdr;
struct mesh_tx_cache *cache;
struct ieee80211_key *key;
struct mesh_path *mppath;
struct sta_info *sta;
u8 *qc;
if (sdata->noack_map ||
!ieee80211_is_data_qos(hdr->frame_control))
return;
build.fast_tx.hdr_len = ieee80211_hdrlen(hdr->frame_control);
meshhdr = (struct ieee80211s_hdr *)(skb->data + build.fast_tx.hdr_len);
build.hdrlen = ieee80211_get_mesh_hdrlen(meshhdr);
cache = &sdata->u.mesh.tx_cache;
if (atomic_read(&cache->rht.nelems) >= MESH_FAST_TX_CACHE_MAX_SIZE)
return;
sta = rcu_dereference(mpath->next_hop);
if (!sta)
return;
build.key.type = MESH_FAST_TX_TYPE_LOCAL;
if ((meshhdr->flags & MESH_FLAGS_AE) == MESH_FLAGS_AE_A5_A6) {
/* This is required to keep the mppath alive */
mppath = mpp_path_lookup(sdata, meshhdr->eaddr1);
if (!mppath)
return;
build.mppath = mppath;
if (!ether_addr_equal(meshhdr->eaddr2, sdata->vif.addr))
build.key.type = MESH_FAST_TX_TYPE_PROXIED;
} else if (ieee80211_has_a4(hdr->frame_control)) {
mppath = mpath;
} else {
return;
}
if (!ether_addr_equal(hdr->addr4, sdata->vif.addr))
build.key.type = MESH_FAST_TX_TYPE_FORWARDED;
/* rate limit, in case fast xmit can't be enabled */
if (mppath->fast_tx_check == jiffies)
return;
mppath->fast_tx_check = jiffies;
/*
* Same use of the sta lock as in ieee80211_check_fast_xmit, in order
* to protect against concurrent sta key updates.
*/
spin_lock_bh(&sta->lock);
key = rcu_access_pointer(sta->ptk[sta->ptk_idx]);
if (!key)
key = rcu_access_pointer(sdata->default_unicast_key);
build.fast_tx.key = key;
if (key) {
bool gen_iv, iv_spc;
gen_iv = key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV;
iv_spc = key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE;
if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) ||
(key->flags & KEY_FLAG_TAINTED))
goto unlock_sta;
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_CCMP_256:
if (gen_iv)
build.fast_tx.pn_offs = build.fast_tx.hdr_len;
if (gen_iv || iv_spc)
build.fast_tx.hdr_len += IEEE80211_CCMP_HDR_LEN;
break;
case WLAN_CIPHER_SUITE_GCMP:
case WLAN_CIPHER_SUITE_GCMP_256:
if (gen_iv)
build.fast_tx.pn_offs = build.fast_tx.hdr_len;
if (gen_iv || iv_spc)
build.fast_tx.hdr_len += IEEE80211_GCMP_HDR_LEN;
break;
default:
goto unlock_sta;
}
}
memcpy(build.key.addr, mppath->dst, ETH_ALEN);
build.timestamp = jiffies;
build.fast_tx.band = info->band;
build.fast_tx.da_offs = offsetof(struct ieee80211_hdr, addr3);
build.fast_tx.sa_offs = offsetof(struct ieee80211_hdr, addr4);
build.mpath = mpath;
memcpy(build.hdr, meshhdr, build.hdrlen);
memcpy(build.hdr + build.hdrlen, rfc1042_header, sizeof(rfc1042_header));
build.hdrlen += sizeof(rfc1042_header);
memcpy(build.fast_tx.hdr, hdr, build.fast_tx.hdr_len);
hdr = (struct ieee80211_hdr *)build.fast_tx.hdr;
if (build.fast_tx.key)
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
qc = ieee80211_get_qos_ctl(hdr);
qc[1] |= IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8;
entry = kmemdup(&build, sizeof(build), GFP_ATOMIC);
if (!entry)
goto unlock_sta;
spin_lock(&cache->walk_lock);
prev = rhashtable_lookup_get_insert_fast(&cache->rht,
&entry->rhash,
fast_tx_rht_params);
if (IS_ERR(prev)) {
kfree(entry);
goto unlock_cache;
}
/*
* replace any previous entry in the hash table, in case we're
* replacing it with a different type (e.g. mpath -> mpp)
*/
if (unlikely(prev)) {
rhashtable_replace_fast(&cache->rht, &prev->rhash,
&entry->rhash, fast_tx_rht_params);
hlist_del_rcu(&prev->walk_list);
kfree_rcu(prev, fast_tx.rcu_head);
}
hlist_add_head(&entry->walk_list, &cache->walk_head);
unlock_cache:
spin_unlock(&cache->walk_lock);
unlock_sta:
spin_unlock_bh(&sta->lock);
}
void mesh_fast_tx_gc(struct ieee80211_sub_if_data *sdata)
{
unsigned long timeout = msecs_to_jiffies(MESH_FAST_TX_CACHE_TIMEOUT);
struct mesh_tx_cache *cache = &sdata->u.mesh.tx_cache;
struct ieee80211_mesh_fast_tx *entry;
struct hlist_node *n;
if (atomic_read(&cache->rht.nelems) < MESH_FAST_TX_CACHE_THRESHOLD_SIZE)
return;
spin_lock_bh(&cache->walk_lock);
hlist_for_each_entry_safe(entry, n, &cache->walk_head, walk_list)
if (!time_is_after_jiffies(entry->timestamp + timeout))
mesh_fast_tx_entry_free(cache, entry);
spin_unlock_bh(&cache->walk_lock);
}
void mesh_fast_tx_flush_mpath(struct mesh_path *mpath)
{
struct ieee80211_sub_if_data *sdata = mpath->sdata;
struct mesh_tx_cache *cache = &sdata->u.mesh.tx_cache;
struct ieee80211_mesh_fast_tx *entry;
struct hlist_node *n;
spin_lock_bh(&cache->walk_lock);
hlist_for_each_entry_safe(entry, n, &cache->walk_head, walk_list)
if (entry->mpath == mpath)
mesh_fast_tx_entry_free(cache, entry);
spin_unlock_bh(&cache->walk_lock);
}
void mesh_fast_tx_flush_sta(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta)
{
struct mesh_tx_cache *cache = &sdata->u.mesh.tx_cache;
struct ieee80211_mesh_fast_tx *entry;
struct hlist_node *n;
spin_lock_bh(&cache->walk_lock);
hlist_for_each_entry_safe(entry, n, &cache->walk_head, walk_list)
if (rcu_access_pointer(entry->mpath->next_hop) == sta)
mesh_fast_tx_entry_free(cache, entry);
spin_unlock_bh(&cache->walk_lock);
}
void mesh_fast_tx_flush_addr(struct ieee80211_sub_if_data *sdata,
const u8 *addr)
{
struct mesh_tx_cache *cache = &sdata->u.mesh.tx_cache;
struct ieee80211_mesh_fast_tx_key key = {};
struct ieee80211_mesh_fast_tx *entry;
int i;
ether_addr_copy(key.addr, addr);
spin_lock_bh(&cache->walk_lock);
for (i = 0; i < NUM_MESH_FAST_TX_TYPE; i++) {
key.type = i;
entry = rhashtable_lookup_fast(&cache->rht, &key, fast_tx_rht_params);
if (entry)
mesh_fast_tx_entry_free(cache, entry);
}
spin_unlock_bh(&cache->walk_lock);
}
/**
* 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;
if (ether_addr_equal(dst, sdata->vif.addr))
/* never add ourselves as neighbours */
return ERR_PTR(-EOPNOTSUPP);
if (is_multicast_ether_addr(dst))
return ERR_PTR(-EOPNOTSUPP);
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;
spin_lock_bh(&tbl->walk_lock);
mpath = rhashtable_lookup_get_insert_fast(&tbl->rhead,
&new_mpath->rhash,
mesh_rht_params);
if (!mpath)
hlist_add_head(&new_mpath->walk_list, &tbl->walk_head);
spin_unlock_bh(&tbl->walk_lock);
if (mpath) {
kfree(new_mpath);
if (IS_ERR(mpath))
return mpath;
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 -EOPNOTSUPP;
if (is_multicast_ether_addr(dst))
return -EOPNOTSUPP;
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;
spin_lock_bh(&tbl->walk_lock);
ret = rhashtable_lookup_insert_fast(&tbl->rhead,
&new_mpath->rhash,
mesh_rht_params);
if (!ret)
hlist_add_head_rcu(&new_mpath->walk_list, &tbl->walk_head);
spin_unlock_bh(&tbl->walk_lock);
if (ret)
kfree(new_mpath);
else
mesh_fast_tx_flush_addr(sdata, dst);
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;
rcu_read_lock();
hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) {
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);
}
}
rcu_read_unlock();
}
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);
timer_shutdown_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)
{
hlist_del_rcu(&mpath->walk_list);
rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params);
if (tbl == &mpath->sdata->u.mesh.mpp_paths)
mesh_fast_tx_flush_addr(mpath->sdata, mpath->dst);
else
mesh_fast_tx_flush_mpath(mpath);
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 hlist_node *n;
spin_lock_bh(&tbl->walk_lock);
hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
if (rcu_access_pointer(mpath->next_hop) == sta)
__mesh_path_del(tbl, mpath);
}
spin_unlock_bh(&tbl->walk_lock);
}
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 hlist_node *n;
spin_lock_bh(&tbl->walk_lock);
hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
if (ether_addr_equal(mpath->mpp, proxy))
__mesh_path_del(tbl, mpath);
}
spin_unlock_bh(&tbl->walk_lock);
}
static void table_flush_by_iface(struct mesh_table *tbl)
{
struct mesh_path *mpath;
struct hlist_node *n;
spin_lock_bh(&tbl->walk_lock);
hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
__mesh_path_del(tbl, mpath);
}
spin_unlock_bh(&tbl->walk_lock);
}
/**
* mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
*
* @sdata: interface data to match
*
* This function deletes both mesh paths as well as mesh portal paths.
*/
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;
spin_lock_bh(&tbl->walk_lock);
mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params);
if (!mpath) {
spin_unlock_bh(&tbl->walk_lock);
return -ENXIO;
}
__mesh_path_del(tbl, mpath);
spin_unlock_bh(&tbl->walk_lock);
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.
*
* Returns: 0 on success, -EHOSTUNREACH
*/
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)
{
ieee80211_free_txskb(&sdata->local->hw, 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 ieee80211_sub_if_data *sdata = mpath->sdata;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_preq_queue *preq, *tmp;
struct sk_buff *skb;
while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
mesh_path_discard_frame(mpath->sdata, skb);
spin_lock_bh(&ifmsh->mesh_preq_queue_lock);
list_for_each_entry_safe(preq, tmp, &ifmsh->preq_queue.list, list) {
if (ether_addr_equal(mpath->dst, preq->dst)) {
list_del(&preq->list);
kfree(preq);
--ifmsh->preq_queue_len;
}
}
spin_unlock_bh(&ifmsh->mesh_preq_queue_lock);
}
/**
* 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);
mesh_fast_tx_flush_mpath(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);
}
void mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata)
{
mesh_table_init(&sdata->u.mesh.mesh_paths);
mesh_table_init(&sdata->u.mesh.mpp_paths);
mesh_fast_tx_init(sdata);
}
static
void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata,
struct mesh_table *tbl)
{
struct mesh_path *mpath;
struct hlist_node *n;
spin_lock_bh(&tbl->walk_lock);
hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) {
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);
}
spin_unlock_bh(&tbl->walk_lock);
}
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_fast_tx_deinit(sdata);
mesh_table_free(&sdata->u.mesh.mesh_paths);
mesh_table_free(&sdata->u.mesh.mpp_paths);
}
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