kernel-fxtec-pro1x/net/mac80211/cfg.c
Johannes Berg 43ba7e958f mac80211: atomically check whether STA exists already
When a STA structure is added, it is often checked whether it
already exists before adding it. This, however, isn't done
atomically so there is a race condition that could lead to two
STA structures being added with the same MAC address. This
patch changes sta_info_add() to return an ERR_PTR in case
of failure and adds the failure mode -EEXIST when the STA
already exists.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-02-29 15:41:34 -05:00

661 lines
15 KiB
C

/*
* mac80211 configuration hooks for cfg80211
*
* Copyright 2006, 2007 Johannes Berg <johannes@sipsolutions.net>
*
* This file is GPLv2 as found in COPYING.
*/
#include <linux/ieee80211.h>
#include <linux/nl80211.h>
#include <linux/rtnetlink.h>
#include <net/net_namespace.h>
#include <linux/rcupdate.h>
#include <net/cfg80211.h>
#include "ieee80211_i.h"
#include "cfg.h"
#include "ieee80211_rate.h"
static enum ieee80211_if_types
nl80211_type_to_mac80211_type(enum nl80211_iftype type)
{
switch (type) {
case NL80211_IFTYPE_UNSPECIFIED:
return IEEE80211_IF_TYPE_STA;
case NL80211_IFTYPE_ADHOC:
return IEEE80211_IF_TYPE_IBSS;
case NL80211_IFTYPE_STATION:
return IEEE80211_IF_TYPE_STA;
case NL80211_IFTYPE_MONITOR:
return IEEE80211_IF_TYPE_MNTR;
default:
return IEEE80211_IF_TYPE_INVALID;
}
}
static int ieee80211_add_iface(struct wiphy *wiphy, char *name,
enum nl80211_iftype type, u32 *flags)
{
struct ieee80211_local *local = wiphy_priv(wiphy);
enum ieee80211_if_types itype;
struct net_device *dev;
struct ieee80211_sub_if_data *sdata;
int err;
if (unlikely(local->reg_state != IEEE80211_DEV_REGISTERED))
return -ENODEV;
itype = nl80211_type_to_mac80211_type(type);
if (itype == IEEE80211_IF_TYPE_INVALID)
return -EINVAL;
err = ieee80211_if_add(local->mdev, name, &dev, itype);
if (err || itype != IEEE80211_IF_TYPE_MNTR || !flags)
return err;
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
sdata->u.mntr_flags = *flags;
return 0;
}
static int ieee80211_del_iface(struct wiphy *wiphy, int ifindex)
{
struct ieee80211_local *local = wiphy_priv(wiphy);
struct net_device *dev;
char *name;
if (unlikely(local->reg_state != IEEE80211_DEV_REGISTERED))
return -ENODEV;
/* we're under RTNL */
dev = __dev_get_by_index(&init_net, ifindex);
if (!dev)
return 0;
name = dev->name;
return ieee80211_if_remove(local->mdev, name, -1);
}
static int ieee80211_change_iface(struct wiphy *wiphy, int ifindex,
enum nl80211_iftype type, u32 *flags)
{
struct ieee80211_local *local = wiphy_priv(wiphy);
struct net_device *dev;
enum ieee80211_if_types itype;
struct ieee80211_sub_if_data *sdata;
if (unlikely(local->reg_state != IEEE80211_DEV_REGISTERED))
return -ENODEV;
/* we're under RTNL */
dev = __dev_get_by_index(&init_net, ifindex);
if (!dev)
return -ENODEV;
if (netif_running(dev))
return -EBUSY;
itype = nl80211_type_to_mac80211_type(type);
if (itype == IEEE80211_IF_TYPE_INVALID)
return -EINVAL;
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN)
return -EOPNOTSUPP;
ieee80211_if_reinit(dev);
ieee80211_if_set_type(dev, itype);
if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR || !flags)
return 0;
sdata->u.mntr_flags = *flags;
return 0;
}
static int ieee80211_add_key(struct wiphy *wiphy, struct net_device *dev,
u8 key_idx, u8 *mac_addr,
struct key_params *params)
{
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta = NULL;
enum ieee80211_key_alg alg;
int ret;
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
switch (params->cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
alg = ALG_WEP;
break;
case WLAN_CIPHER_SUITE_TKIP:
alg = ALG_TKIP;
break;
case WLAN_CIPHER_SUITE_CCMP:
alg = ALG_CCMP;
break;
default:
return -EINVAL;
}
if (mac_addr) {
sta = sta_info_get(sdata->local, mac_addr);
if (!sta)
return -ENOENT;
}
ret = 0;
if (!ieee80211_key_alloc(sdata, sta, alg, key_idx,
params->key_len, params->key))
ret = -ENOMEM;
if (sta)
sta_info_put(sta);
return ret;
}
static int ieee80211_del_key(struct wiphy *wiphy, struct net_device *dev,
u8 key_idx, u8 *mac_addr)
{
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
int ret;
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
if (mac_addr) {
sta = sta_info_get(sdata->local, mac_addr);
if (!sta)
return -ENOENT;
ret = 0;
if (sta->key)
ieee80211_key_free(sta->key);
else
ret = -ENOENT;
sta_info_put(sta);
return ret;
}
if (!sdata->keys[key_idx])
return -ENOENT;
ieee80211_key_free(sdata->keys[key_idx]);
return 0;
}
static int ieee80211_get_key(struct wiphy *wiphy, struct net_device *dev,
u8 key_idx, u8 *mac_addr, void *cookie,
void (*callback)(void *cookie,
struct key_params *params))
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct sta_info *sta = NULL;
u8 seq[6] = {0};
struct key_params params;
struct ieee80211_key *key;
u32 iv32;
u16 iv16;
int err = -ENOENT;
if (mac_addr) {
sta = sta_info_get(sdata->local, mac_addr);
if (!sta)
goto out;
key = sta->key;
} else
key = sdata->keys[key_idx];
if (!key)
goto out;
memset(&params, 0, sizeof(params));
switch (key->conf.alg) {
case ALG_TKIP:
params.cipher = WLAN_CIPHER_SUITE_TKIP;
iv32 = key->u.tkip.iv32;
iv16 = key->u.tkip.iv16;
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE &&
sdata->local->ops->get_tkip_seq)
sdata->local->ops->get_tkip_seq(
local_to_hw(sdata->local),
key->conf.hw_key_idx,
&iv32, &iv16);
seq[0] = iv16 & 0xff;
seq[1] = (iv16 >> 8) & 0xff;
seq[2] = iv32 & 0xff;
seq[3] = (iv32 >> 8) & 0xff;
seq[4] = (iv32 >> 16) & 0xff;
seq[5] = (iv32 >> 24) & 0xff;
params.seq = seq;
params.seq_len = 6;
break;
case ALG_CCMP:
params.cipher = WLAN_CIPHER_SUITE_CCMP;
seq[0] = key->u.ccmp.tx_pn[5];
seq[1] = key->u.ccmp.tx_pn[4];
seq[2] = key->u.ccmp.tx_pn[3];
seq[3] = key->u.ccmp.tx_pn[2];
seq[4] = key->u.ccmp.tx_pn[1];
seq[5] = key->u.ccmp.tx_pn[0];
params.seq = seq;
params.seq_len = 6;
break;
case ALG_WEP:
if (key->conf.keylen == 5)
params.cipher = WLAN_CIPHER_SUITE_WEP40;
else
params.cipher = WLAN_CIPHER_SUITE_WEP104;
break;
}
params.key = key->conf.key;
params.key_len = key->conf.keylen;
callback(cookie, &params);
err = 0;
out:
if (sta)
sta_info_put(sta);
return err;
}
static int ieee80211_config_default_key(struct wiphy *wiphy,
struct net_device *dev,
u8 key_idx)
{
struct ieee80211_sub_if_data *sdata;
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
ieee80211_set_default_key(sdata, key_idx);
return 0;
}
static int ieee80211_get_station(struct wiphy *wiphy, struct net_device *dev,
u8 *mac, struct station_stats *stats)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct sta_info *sta;
sta = sta_info_get(local, mac);
if (!sta)
return -ENOENT;
/* XXX: verify sta->dev == dev */
stats->filled = STATION_STAT_INACTIVE_TIME |
STATION_STAT_RX_BYTES |
STATION_STAT_TX_BYTES;
stats->inactive_time = jiffies_to_msecs(jiffies - sta->last_rx);
stats->rx_bytes = sta->rx_bytes;
stats->tx_bytes = sta->tx_bytes;
sta_info_put(sta);
return 0;
}
/*
* This handles both adding a beacon and setting new beacon info
*/
static int ieee80211_config_beacon(struct ieee80211_sub_if_data *sdata,
struct beacon_parameters *params)
{
struct beacon_data *new, *old;
int new_head_len, new_tail_len;
int size;
int err = -EINVAL;
old = sdata->u.ap.beacon;
/* head must not be zero-length */
if (params->head && !params->head_len)
return -EINVAL;
/*
* This is a kludge. beacon interval should really be part
* of the beacon information.
*/
if (params->interval) {
sdata->local->hw.conf.beacon_int = params->interval;
if (ieee80211_hw_config(sdata->local))
return -EINVAL;
/*
* We updated some parameter so if below bails out
* it's not an error.
*/
err = 0;
}
/* Need to have a beacon head if we don't have one yet */
if (!params->head && !old)
return err;
/* sorry, no way to start beaconing without dtim period */
if (!params->dtim_period && !old)
return err;
/* new or old head? */
if (params->head)
new_head_len = params->head_len;
else
new_head_len = old->head_len;
/* new or old tail? */
if (params->tail || !old)
/* params->tail_len will be zero for !params->tail */
new_tail_len = params->tail_len;
else
new_tail_len = old->tail_len;
size = sizeof(*new) + new_head_len + new_tail_len;
new = kzalloc(size, GFP_KERNEL);
if (!new)
return -ENOMEM;
/* start filling the new info now */
/* new or old dtim period? */
if (params->dtim_period)
new->dtim_period = params->dtim_period;
else
new->dtim_period = old->dtim_period;
/*
* pointers go into the block we allocated,
* memory is | beacon_data | head | tail |
*/
new->head = ((u8 *) new) + sizeof(*new);
new->tail = new->head + new_head_len;
new->head_len = new_head_len;
new->tail_len = new_tail_len;
/* copy in head */
if (params->head)
memcpy(new->head, params->head, new_head_len);
else
memcpy(new->head, old->head, new_head_len);
/* copy in optional tail */
if (params->tail)
memcpy(new->tail, params->tail, new_tail_len);
else
if (old)
memcpy(new->tail, old->tail, new_tail_len);
rcu_assign_pointer(sdata->u.ap.beacon, new);
synchronize_rcu();
kfree(old);
return ieee80211_if_config_beacon(sdata->dev);
}
static int ieee80211_add_beacon(struct wiphy *wiphy, struct net_device *dev,
struct beacon_parameters *params)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct beacon_data *old;
if (sdata->vif.type != IEEE80211_IF_TYPE_AP)
return -EINVAL;
old = sdata->u.ap.beacon;
if (old)
return -EALREADY;
return ieee80211_config_beacon(sdata, params);
}
static int ieee80211_set_beacon(struct wiphy *wiphy, struct net_device *dev,
struct beacon_parameters *params)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct beacon_data *old;
if (sdata->vif.type != IEEE80211_IF_TYPE_AP)
return -EINVAL;
old = sdata->u.ap.beacon;
if (!old)
return -ENOENT;
return ieee80211_config_beacon(sdata, params);
}
static int ieee80211_del_beacon(struct wiphy *wiphy, struct net_device *dev)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct beacon_data *old;
if (sdata->vif.type != IEEE80211_IF_TYPE_AP)
return -EINVAL;
old = sdata->u.ap.beacon;
if (!old)
return -ENOENT;
rcu_assign_pointer(sdata->u.ap.beacon, NULL);
synchronize_rcu();
kfree(old);
return ieee80211_if_config_beacon(dev);
}
/* Layer 2 Update frame (802.2 Type 1 LLC XID Update response) */
struct iapp_layer2_update {
u8 da[ETH_ALEN]; /* broadcast */
u8 sa[ETH_ALEN]; /* STA addr */
__be16 len; /* 6 */
u8 dsap; /* 0 */
u8 ssap; /* 0 */
u8 control;
u8 xid_info[3];
} __attribute__ ((packed));
static void ieee80211_send_layer2_update(struct sta_info *sta)
{
struct iapp_layer2_update *msg;
struct sk_buff *skb;
/* Send Level 2 Update Frame to update forwarding tables in layer 2
* bridge devices */
skb = dev_alloc_skb(sizeof(*msg));
if (!skb)
return;
msg = (struct iapp_layer2_update *)skb_put(skb, sizeof(*msg));
/* 802.2 Type 1 Logical Link Control (LLC) Exchange Identifier (XID)
* Update response frame; IEEE Std 802.2-1998, 5.4.1.2.1 */
memset(msg->da, 0xff, ETH_ALEN);
memcpy(msg->sa, sta->addr, ETH_ALEN);
msg->len = htons(6);
msg->dsap = 0;
msg->ssap = 0x01; /* NULL LSAP, CR Bit: Response */
msg->control = 0xaf; /* XID response lsb.1111F101.
* F=0 (no poll command; unsolicited frame) */
msg->xid_info[0] = 0x81; /* XID format identifier */
msg->xid_info[1] = 1; /* LLC types/classes: Type 1 LLC */
msg->xid_info[2] = 0; /* XID sender's receive window size (RW) */
skb->dev = sta->dev;
skb->protocol = eth_type_trans(skb, sta->dev);
memset(skb->cb, 0, sizeof(skb->cb));
netif_rx(skb);
}
static void sta_apply_parameters(struct ieee80211_local *local,
struct sta_info *sta,
struct station_parameters *params)
{
u32 rates;
int i, j;
struct ieee80211_supported_band *sband;
if (params->station_flags & STATION_FLAG_CHANGED) {
sta->flags &= ~WLAN_STA_AUTHORIZED;
if (params->station_flags & STATION_FLAG_AUTHORIZED)
sta->flags |= WLAN_STA_AUTHORIZED;
sta->flags &= ~WLAN_STA_SHORT_PREAMBLE;
if (params->station_flags & STATION_FLAG_SHORT_PREAMBLE)
sta->flags |= WLAN_STA_SHORT_PREAMBLE;
sta->flags &= ~WLAN_STA_WME;
if (params->station_flags & STATION_FLAG_WME)
sta->flags |= WLAN_STA_WME;
}
if (params->aid) {
sta->aid = params->aid;
if (sta->aid > IEEE80211_MAX_AID)
sta->aid = 0; /* XXX: should this be an error? */
}
if (params->listen_interval >= 0)
sta->listen_interval = params->listen_interval;
if (params->supported_rates) {
rates = 0;
sband = local->hw.wiphy->bands[local->oper_channel->band];
for (i = 0; i < params->supported_rates_len; i++) {
int rate = (params->supported_rates[i] & 0x7f) * 5;
for (j = 0; j < sband->n_bitrates; j++) {
if (sband->bitrates[j].bitrate == rate)
rates |= BIT(j);
}
}
sta->supp_rates[local->oper_channel->band] = rates;
}
}
static int ieee80211_add_station(struct wiphy *wiphy, struct net_device *dev,
u8 *mac, struct station_parameters *params)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct sta_info *sta;
struct ieee80211_sub_if_data *sdata;
/* Prevent a race with changing the rate control algorithm */
if (!netif_running(dev))
return -ENETDOWN;
if (params->vlan) {
sdata = IEEE80211_DEV_TO_SUB_IF(params->vlan);
if (sdata->vif.type != IEEE80211_IF_TYPE_VLAN ||
sdata->vif.type != IEEE80211_IF_TYPE_AP)
return -EINVAL;
} else
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
sta = sta_info_add(local, dev, mac, GFP_KERNEL);
if (IS_ERR(sta))
return PTR_ERR(sta);
sta->dev = sdata->dev;
if (sdata->vif.type == IEEE80211_IF_TYPE_VLAN ||
sdata->vif.type == IEEE80211_IF_TYPE_AP)
ieee80211_send_layer2_update(sta);
sta->flags = WLAN_STA_AUTH | WLAN_STA_ASSOC;
sta_apply_parameters(local, sta, params);
rate_control_rate_init(sta, local);
sta_info_put(sta);
return 0;
}
static int ieee80211_del_station(struct wiphy *wiphy, struct net_device *dev,
u8 *mac)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct sta_info *sta;
if (mac) {
/* XXX: get sta belonging to dev */
sta = sta_info_get(local, mac);
if (!sta)
return -ENOENT;
sta_info_free(sta);
sta_info_put(sta);
} else
sta_info_flush(local, dev);
return 0;
}
static int ieee80211_change_station(struct wiphy *wiphy,
struct net_device *dev,
u8 *mac,
struct station_parameters *params)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct sta_info *sta;
struct ieee80211_sub_if_data *vlansdata;
/* XXX: get sta belonging to dev */
sta = sta_info_get(local, mac);
if (!sta)
return -ENOENT;
if (params->vlan && params->vlan != sta->dev) {
vlansdata = IEEE80211_DEV_TO_SUB_IF(params->vlan);
if (vlansdata->vif.type != IEEE80211_IF_TYPE_VLAN ||
vlansdata->vif.type != IEEE80211_IF_TYPE_AP)
return -EINVAL;
sta->dev = params->vlan;
ieee80211_send_layer2_update(sta);
}
sta_apply_parameters(local, sta, params);
sta_info_put(sta);
return 0;
}
struct cfg80211_ops mac80211_config_ops = {
.add_virtual_intf = ieee80211_add_iface,
.del_virtual_intf = ieee80211_del_iface,
.change_virtual_intf = ieee80211_change_iface,
.add_key = ieee80211_add_key,
.del_key = ieee80211_del_key,
.get_key = ieee80211_get_key,
.set_default_key = ieee80211_config_default_key,
.add_beacon = ieee80211_add_beacon,
.set_beacon = ieee80211_set_beacon,
.del_beacon = ieee80211_del_beacon,
.add_station = ieee80211_add_station,
.del_station = ieee80211_del_station,
.change_station = ieee80211_change_station,
.get_station = ieee80211_get_station,
};