/*
* Copyright (c) 2008 open80211s Ltd.
* Authors: Luis Carlos Cobo <luisca@cozybit.com>
* Javier Cardona <javier@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 <asm/unaligned.h>
#include "ieee80211_i.h"
#include "mesh.h"
#define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
#define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
#define PP_OFFSET 1 /* Path Selection Protocol */
#define PM_OFFSET 5 /* Path Selection Metric */
#define CC_OFFSET 9 /* Congestion Control Mode */
#define CAPAB_OFFSET 17
#define ACCEPT_PLINKS 0x80
int mesh_allocated;
static struct kmem_cache *rm_cache;
void ieee80211s_init(void)
{
mesh_pathtbl_init();
mesh_allocated = 1;
rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry),
0, 0, NULL);
}
void ieee80211s_stop(void)
{
mesh_pathtbl_unregister();
kmem_cache_destroy(rm_cache);
}
static void ieee80211_mesh_housekeeping_timer(unsigned long data)
{
struct ieee80211_sub_if_data *sdata = (void *) data;
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
ifmsh->housekeeping = true;
queue_work(local->hw.workqueue, &ifmsh->work);
}
/**
* mesh_matches_local - check if the config of a mesh point matches ours
*
* @ie: information elements of a management frame from the mesh peer
* @sdata: local mesh subif
*
* This function checks if the mesh configuration of a mesh point matches the
* local mesh configuration, i.e. if both nodes belong to the same mesh network.
*/
bool mesh_matches_local(struct ieee802_11_elems *ie, struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
/*
* As support for each feature is added, check for matching
* - On mesh config capabilities
* - Power Save Support En
* - Sync support enabled
* - Sync support active
* - Sync support required from peer
* - MDA enabled
* - Power management control on fc
*/
if (ifmsh->mesh_id_len == ie->mesh_id_len &&
memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 &&
memcmp(ifmsh->mesh_pp_id, ie->mesh_config + PP_OFFSET, 4) == 0 &&
memcmp(ifmsh->mesh_pm_id, ie->mesh_config + PM_OFFSET, 4) == 0 &&
memcmp(ifmsh->mesh_cc_id, ie->mesh_config + CC_OFFSET, 4) == 0)
return true;
return false;
}
/**
* mesh_peer_accepts_plinks - check if an mp is willing to establish peer links
*
* @ie: information elements of a management frame from the mesh peer
*/
bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie)
{
return (*(ie->mesh_config + CAPAB_OFFSET) & ACCEPT_PLINKS) != 0;
}
/**
* mesh_accept_plinks_update: update accepting_plink in local mesh beacons
*
* @sdata: mesh interface in which mesh beacons are going to be updated
*/
void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata)
{
bool free_plinks;
/* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0,
* the mesh interface might be able to establish plinks with peers that
* are already on the table but are not on PLINK_ESTAB state. However,
* in general the mesh interface is not accepting peer link requests
* from new peers, and that must be reflected in the beacon
*/
free_plinks = mesh_plink_availables(sdata);
if (free_plinks != sdata->u.mesh.accepting_plinks)
ieee80211_mesh_housekeeping_timer((unsigned long) sdata);
}
void mesh_ids_set_default(struct ieee80211_if_mesh *sta)
{
u8 def_id[4] = {0x00, 0x0F, 0xAC, 0xff};
memcpy(sta->mesh_pp_id, def_id, 4);
memcpy(sta->mesh_pm_id, def_id, 4);
memcpy(sta->mesh_cc_id, def_id, 4);
}
int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
{
int i;
sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL);
if (!sdata->u.mesh.rmc)
return -ENOMEM;
sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1;
for (i = 0; i < RMC_BUCKETS; i++)
INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i].list);
return 0;
}
void mesh_rmc_free(struct ieee80211_sub_if_data *sdata)
{
struct mesh_rmc *rmc = sdata->u.mesh.rmc;
struct rmc_entry *p, *n;
int i;
if (!sdata->u.mesh.rmc)
return;
for (i = 0; i < RMC_BUCKETS; i++)
list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) {
list_del(&p->list);
kmem_cache_free(rm_cache, p);
}
kfree(rmc);
sdata->u.mesh.rmc = NULL;
}
/**
* mesh_rmc_check - Check frame in recent multicast cache and add if absent.
*
* @sa: source address
* @mesh_hdr: mesh_header
*
* Returns: 0 if the frame is not in the cache, nonzero otherwise.
*
* Checks using the source address and the mesh sequence number if we have
* received this frame lately. If the frame is not in the cache, it is added to
* it.
*/
int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
struct ieee80211_sub_if_data *sdata)
{
struct mesh_rmc *rmc = sdata->u.mesh.rmc;
u32 seqnum = 0;
int entries = 0;
u8 idx;
struct rmc_entry *p, *n;
/* Don't care about endianness since only match matters */
memcpy(&seqnum, &mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum));
idx = le32_to_cpu(mesh_hdr->seqnum) & rmc->idx_mask;
list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) {
++entries;
if (time_after(jiffies, p->exp_time) ||
(entries == RMC_QUEUE_MAX_LEN)) {
list_del(&p->list);
kmem_cache_free(rm_cache, p);
--entries;
} else if ((seqnum == p->seqnum)
&& (memcmp(sa, p->sa, ETH_ALEN) == 0))
return -1;
}
p = kmem_cache_alloc(rm_cache, GFP_ATOMIC);
if (!p) {
printk(KERN_DEBUG "o11s: could not allocate RMC entry\n");
return 0;
}
p->seqnum = seqnum;
p->exp_time = jiffies + RMC_TIMEOUT;
memcpy(p->sa, sa, ETH_ALEN);
list_add(&p->list, &rmc->bucket[idx].list);
return 0;
}
void mesh_mgmt_ies_add(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_supported_band *sband;
u8 *pos;
int len, i, rate;
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
len = sband->n_bitrates;
if (len > 8)
len = 8;
pos = skb_put(skb, len + 2);
*pos++ = WLAN_EID_SUPP_RATES;
*pos++ = len;
for (i = 0; i < len; i++) {
rate = sband->bitrates[i].bitrate;
*pos++ = (u8) (rate / 5);
}
if (sband->n_bitrates > len) {
pos = skb_put(skb, sband->n_bitrates - len + 2);
*pos++ = WLAN_EID_EXT_SUPP_RATES;
*pos++ = sband->n_bitrates - len;
for (i = len; i < sband->n_bitrates; i++) {
rate = sband->bitrates[i].bitrate;
*pos++ = (u8) (rate / 5);
}
}
pos = skb_put(skb, 2 + sdata->u.mesh.mesh_id_len);
*pos++ = WLAN_EID_MESH_ID;
*pos++ = sdata->u.mesh.mesh_id_len;
if (sdata->u.mesh.mesh_id_len)
memcpy(pos, sdata->u.mesh.mesh_id, sdata->u.mesh.mesh_id_len);
pos = skb_put(skb, 21);
*pos++ = WLAN_EID_MESH_CONFIG;
*pos++ = MESH_CFG_LEN;
/* Version */
*pos++ = 1;
/* Active path selection protocol ID */
memcpy(pos, sdata->u.mesh.mesh_pp_id, 4);
pos += 4;
/* Active path selection metric ID */
memcpy(pos, sdata->u.mesh.mesh_pm_id, 4);
pos += 4;
/* Congestion control mode identifier */
memcpy(pos, sdata->u.mesh.mesh_cc_id, 4);
pos += 4;
/* Channel precedence:
* Not running simple channel unification protocol
*/
memset(pos, 0x00, 4);
pos += 4;
/* Mesh capability */
sdata->u.mesh.accepting_plinks = mesh_plink_availables(sdata);
*pos++ = sdata->u.mesh.accepting_plinks ? ACCEPT_PLINKS : 0x00;
*pos++ = 0x00;
return;
}
u32 mesh_table_hash(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;
}
u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len)
{
if (!mesh_id_len)
return 1;
else if (mesh_id_len == 1)
return (u8) mesh_id[0];
else
return (u8) (mesh_id[0] + 2 * mesh_id[1]);
}
struct mesh_table *mesh_table_alloc(int size_order)
{
int i;
struct mesh_table *newtbl;
newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL);
if (!newtbl)
return NULL;
newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) *
(1 << size_order), GFP_KERNEL);
if (!newtbl->hash_buckets) {
kfree(newtbl);
return NULL;
}
newtbl->hashwlock = kmalloc(sizeof(spinlock_t) *
(1 << size_order), GFP_KERNEL);
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]);
return newtbl;
}
static void __mesh_table_free(struct mesh_table *tbl)
{
kfree(tbl->hash_buckets);
kfree(tbl->hashwlock);
kfree(tbl);
}
void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
{
struct hlist_head *mesh_hash;
struct hlist_node *p, *q;
int i;
mesh_hash = tbl->hash_buckets;
for (i = 0; i <= tbl->hash_mask; i++) {
spin_lock(&tbl->hashwlock[i]);
hlist_for_each_safe(p, q, &mesh_hash[i]) {
tbl->free_node(p, free_leafs);
atomic_dec(&tbl->entries);
}
spin_unlock(&tbl->hashwlock[i]);
}
__mesh_table_free(tbl);
}
static void ieee80211_mesh_path_timer(unsigned long data)
{
struct ieee80211_sub_if_data *sdata =
(struct ieee80211_sub_if_data *) data;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
queue_work(local->hw.workqueue, &ifmsh->work);
}
struct mesh_table *mesh_table_grow(struct mesh_table *tbl)
{
struct mesh_table *newtbl;
struct hlist_head *oldhash;
struct hlist_node *p, *q;
int i;
if (atomic_read(&tbl->entries)
< tbl->mean_chain_len * (tbl->hash_mask + 1))
goto endgrow;
newtbl = mesh_table_alloc(tbl->size_order + 1);
if (!newtbl)
goto endgrow;
newtbl->free_node = tbl->free_node;
newtbl->mean_chain_len = tbl->mean_chain_len;
newtbl->copy_node = tbl->copy_node;
atomic_set(&newtbl->entries, atomic_read(&tbl->entries));
oldhash = tbl->hash_buckets;
for (i = 0; i <= tbl->hash_mask; i++)
hlist_for_each(p, &oldhash[i])
if (tbl->copy_node(p, newtbl) < 0)
goto errcopy;
return newtbl;
errcopy:
for (i = 0; i <= newtbl->hash_mask; i++) {
hlist_for_each_safe(p, q, &newtbl->hash_buckets[i])
tbl->free_node(p, 0);
}
__mesh_table_free(newtbl);
endgrow:
return NULL;
}
/**
* ieee80211_new_mesh_header - create a new mesh header
* @meshhdr: uninitialized mesh header
* @sdata: mesh interface to be used
*
* Return the header length.
*/
int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
struct ieee80211_sub_if_data *sdata)
{
meshhdr->flags = 0;
meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
sdata->u.mesh.mesh_seqnum++;
return 6;
}
static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata,
struct ieee80211_if_mesh *ifmsh)
{
bool free_plinks;
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: running mesh housekeeping\n",
sdata->dev->name);
#endif
ieee80211_sta_expire(sdata, IEEE80211_MESH_PEER_INACTIVITY_LIMIT);
mesh_path_expire(sdata);
free_plinks = mesh_plink_availables(sdata);
if (free_plinks != sdata->u.mesh.accepting_plinks)
ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON);
ifmsh->housekeeping = false;
mod_timer(&ifmsh->housekeeping_timer,
round_jiffies(jiffies + IEEE80211_MESH_HOUSEKEEPING_INTERVAL));
}
void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
ifmsh->housekeeping = true;
queue_work(local->hw.workqueue, &ifmsh->work);
ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON);
}
void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata)
{
del_timer_sync(&sdata->u.mesh.housekeeping_timer);
/*
* If the timer fired while we waited for it, it will have
* requeued the work. Now the work will be running again
* but will not rearm the timer again because it checks
* whether the interface is running, which, at this point,
* it no longer is.
*/
cancel_work_sync(&sdata->u.mesh.work);
/*
* When we get here, the interface is marked down.
* Call synchronize_rcu() to wait for the RX path
* should it be using the interface and enqueuing
* frames at this very time on another CPU.
*/
synchronize_rcu();
skb_queue_purge(&sdata->u.mesh.skb_queue);
}
static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
u16 stype,
struct ieee80211_mgmt *mgmt,
size_t len,
struct ieee80211_rx_status *rx_status)
{
struct ieee80211_local *local= sdata->local;
struct ieee802_11_elems elems;
struct ieee80211_channel *channel;
u64 supp_rates = 0;
size_t baselen;
int freq;
enum ieee80211_band band = rx_status->band;
/* ignore ProbeResp to foreign address */
if (stype == IEEE80211_STYPE_PROBE_RESP &&
compare_ether_addr(mgmt->da, sdata->dev->dev_addr))
return;
baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
if (baselen > len)
return;
ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
&elems);
if (elems.ds_params && elems.ds_params_len == 1)
freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
else
freq = rx_status->freq;
channel = ieee80211_get_channel(local->hw.wiphy, freq);
if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
return;
if (elems.mesh_id && elems.mesh_config &&
mesh_matches_local(&elems, sdata)) {
supp_rates = ieee80211_sta_get_rates(local, &elems, band);
mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
mesh_peer_accepts_plinks(&elems));
}
}
static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
size_t len,
struct ieee80211_rx_status *rx_status)
{
switch (mgmt->u.action.category) {
case PLINK_CATEGORY:
mesh_rx_plink_frame(sdata, mgmt, len, rx_status);
break;
case MESH_PATH_SEL_CATEGORY:
mesh_rx_path_sel_frame(sdata, mgmt, len);
break;
}
}
static void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
struct sk_buff *skb)
{
struct ieee80211_rx_status *rx_status;
struct ieee80211_if_mesh *ifmsh;
struct ieee80211_mgmt *mgmt;
u16 stype;
ifmsh = &sdata->u.mesh;
rx_status = (struct ieee80211_rx_status *) skb->cb;
mgmt = (struct ieee80211_mgmt *) skb->data;
stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE;
switch (stype) {
case IEEE80211_STYPE_PROBE_RESP:
case IEEE80211_STYPE_BEACON:
ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len,
rx_status);
break;
case IEEE80211_STYPE_ACTION:
ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status);
break;
}
kfree_skb(skb);
}
static void ieee80211_mesh_work(struct work_struct *work)
{
struct ieee80211_sub_if_data *sdata =
container_of(work, struct ieee80211_sub_if_data, u.mesh.work);
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct sk_buff *skb;
if (!netif_running(sdata->dev))
return;
if (local->sw_scanning || local->hw_scanning)
return;
while ((skb = skb_dequeue(&ifmsh->skb_queue)))
ieee80211_mesh_rx_queued_mgmt(sdata, skb);
if (ifmsh->preq_queue_len &&
time_after(jiffies,
ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval)))
mesh_path_start_discovery(sdata);
if (ifmsh->housekeeping)
ieee80211_mesh_housekeeping(sdata, ifmsh);
}
void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;
rcu_read_lock();
list_for_each_entry_rcu(sdata, &local->interfaces, list)
if (ieee80211_vif_is_mesh(&sdata->vif))
queue_work(local->hw.workqueue, &sdata->u.mesh.work);
rcu_read_unlock();
}
void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
INIT_WORK(&ifmsh->work, ieee80211_mesh_work);
setup_timer(&ifmsh->housekeeping_timer,
ieee80211_mesh_housekeeping_timer,
(unsigned long) sdata);
skb_queue_head_init(&sdata->u.mesh.skb_queue);
ifmsh->mshcfg.dot11MeshRetryTimeout = MESH_RET_T;
ifmsh->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T;
ifmsh->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T;
ifmsh->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR;
ifmsh->mshcfg.dot11MeshTTL = MESH_TTL;
ifmsh->mshcfg.auto_open_plinks = true;
ifmsh->mshcfg.dot11MeshMaxPeerLinks =
MESH_MAX_ESTAB_PLINKS;
ifmsh->mshcfg.dot11MeshHWMPactivePathTimeout =
MESH_PATH_TIMEOUT;
ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval =
MESH_PREQ_MIN_INT;
ifmsh->mshcfg.dot11MeshHWMPnetDiameterTraversalTime =
MESH_DIAM_TRAVERSAL_TIME;
ifmsh->mshcfg.dot11MeshHWMPmaxPREQretries =
MESH_MAX_PREQ_RETRIES;
ifmsh->mshcfg.path_refresh_time =
MESH_PATH_REFRESH_TIME;
ifmsh->mshcfg.min_discovery_timeout =
MESH_MIN_DISCOVERY_TIMEOUT;
ifmsh->accepting_plinks = true;
ifmsh->preq_id = 0;
ifmsh->dsn = 0;
atomic_set(&ifmsh->mpaths, 0);
mesh_rmc_init(sdata);
ifmsh->last_preq = jiffies;
/* Allocate all mesh structures when creating the first mesh interface. */
if (!mesh_allocated)
ieee80211s_init();
mesh_ids_set_default(ifmsh);
setup_timer(&ifmsh->mesh_path_timer,
ieee80211_mesh_path_timer,
(unsigned long) sdata);
INIT_LIST_HEAD(&ifmsh->preq_queue.list);
spin_lock_init(&ifmsh->mesh_preq_queue_lock);
}
ieee80211_rx_result
ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
struct ieee80211_rx_status *rx_status)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_mgmt *mgmt;
u16 fc;
if (skb->len < 24)
return RX_DROP_MONITOR;
mgmt = (struct ieee80211_mgmt *) skb->data;
fc = le16_to_cpu(mgmt->frame_control);
switch (fc & IEEE80211_FCTL_STYPE) {
case IEEE80211_STYPE_PROBE_RESP:
case IEEE80211_STYPE_BEACON:
case IEEE80211_STYPE_ACTION:
memcpy(skb->cb, rx_status, sizeof(*rx_status));
skb_queue_tail(&ifmsh->skb_queue, skb);
queue_work(local->hw.workqueue, &ifmsh->work);
return RX_QUEUED;
}
return RX_CONTINUE;
}
