alistair23-linux/net/wireless/wext-sme.c
Johannes Berg 59bbb6f757 cfg80211: validate channel settings across interfaces
Currently, there's a problem that affects regulatory
enforcement and connection stability, in that it is
possible to switch the channel while connected to a
network or joined to an IBSS.

The problem comes from the fact that we only validate
the channel against the current interface's type, not
against any other interface. Thus, you have any type
of interface up, additionally bring up a monitor mode
interface and switch the channel on the monitor. This
will obviously also switch the channel on the other
interface.

The problem now is that if you do that while sending
beacons for IBSS mode, you can switch to a disabled
channel or a channel that doesn't allow beaconing.
Combined with a managed mode interface connected to
an AP instead of an IBSS interface, you can easily
break the connection that way.

To fix this, this patch validates any channel change
with all available interfaces, and disallows such
changes on secondary interfaces if another interface
is connected to an AP or joined to an IBSS.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-14 09:13:42 -04:00

399 lines
9 KiB
C

/*
* cfg80211 wext compat for managed mode.
*
* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
* Copyright (C) 2009 Intel Corporation. All rights reserved.
*/
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <net/cfg80211.h>
#include "wext-compat.h"
#include "nl80211.h"
int cfg80211_mgd_wext_connect(struct cfg80211_registered_device *rdev,
struct wireless_dev *wdev)
{
struct cfg80211_cached_keys *ck = NULL;
int err, i;
ASSERT_RDEV_LOCK(rdev);
ASSERT_WDEV_LOCK(wdev);
if (!netif_running(wdev->netdev))
return 0;
wdev->wext.connect.ie = wdev->wext.ie;
wdev->wext.connect.ie_len = wdev->wext.ie_len;
wdev->wext.connect.privacy = wdev->wext.default_key != -1;
if (wdev->wext.keys) {
wdev->wext.keys->def = wdev->wext.default_key;
wdev->wext.keys->defmgmt = wdev->wext.default_mgmt_key;
}
if (!wdev->wext.connect.ssid_len)
return 0;
if (wdev->wext.keys) {
ck = kmemdup(wdev->wext.keys, sizeof(*ck), GFP_KERNEL);
if (!ck)
return -ENOMEM;
for (i = 0; i < 6; i++)
ck->params[i].key = ck->data[i];
}
err = __cfg80211_connect(rdev, wdev->netdev,
&wdev->wext.connect, ck);
if (err)
kfree(ck);
return err;
}
int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *wextfreq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
struct ieee80211_channel *chan = NULL;
int err, freq;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
if (freq < 0)
return freq;
if (freq) {
chan = ieee80211_get_channel(wdev->wiphy, freq);
if (!chan)
return -EINVAL;
if (chan->flags & IEEE80211_CHAN_DISABLED)
return -EINVAL;
}
cfg80211_lock_rdev(rdev);
mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
if (wdev->sme_state != CFG80211_SME_IDLE) {
bool event = true;
if (wdev->wext.connect.channel == chan) {
err = 0;
goto out;
}
/* if SSID set, we'll try right again, avoid event */
if (wdev->wext.connect.ssid_len)
event = false;
err = __cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
wdev->wext.connect.channel = chan;
/* SSID is not set, we just want to switch channel */
if (chan && !wdev->wext.connect.ssid_len) {
err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
goto out;
}
err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
mutex_unlock(&rdev->devlist_mtx);
cfg80211_unlock_rdev(rdev);
return err;
}
int cfg80211_mgd_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *freq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct ieee80211_channel *chan = NULL;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
wdev_lock(wdev);
if (wdev->current_bss)
chan = wdev->current_bss->pub.channel;
else if (wdev->wext.connect.channel)
chan = wdev->wext.connect.channel;
wdev_unlock(wdev);
if (chan) {
freq->m = chan->center_freq;
freq->e = 6;
return 0;
}
/* no channel if not joining */
return -EINVAL;
}
int cfg80211_mgd_wext_siwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
size_t len = data->length;
int err;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
if (!data->flags)
len = 0;
/* iwconfig uses nul termination in SSID.. */
if (len > 0 && ssid[len - 1] == '\0')
len--;
cfg80211_lock_rdev(rdev);
mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
err = 0;
if (wdev->sme_state != CFG80211_SME_IDLE) {
bool event = true;
if (wdev->wext.connect.ssid && len &&
len == wdev->wext.connect.ssid_len &&
memcmp(wdev->wext.connect.ssid, ssid, len) == 0)
goto out;
/* if SSID set now, we'll try to connect, avoid event */
if (len)
event = false;
err = __cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
wdev->wext.connect.ssid = wdev->wext.ssid;
memcpy(wdev->wext.ssid, ssid, len);
wdev->wext.connect.ssid_len = len;
wdev->wext.connect.crypto.control_port = false;
err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
mutex_unlock(&rdev->devlist_mtx);
cfg80211_unlock_rdev(rdev);
return err;
}
int cfg80211_mgd_wext_giwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
data->flags = 0;
wdev_lock(wdev);
if (wdev->current_bss) {
const u8 *ie = ieee80211_bss_get_ie(&wdev->current_bss->pub,
WLAN_EID_SSID);
if (ie) {
data->flags = 1;
data->length = ie[1];
memcpy(ssid, ie + 2, data->length);
}
} else if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) {
data->flags = 1;
data->length = wdev->wext.connect.ssid_len;
memcpy(ssid, wdev->wext.connect.ssid, data->length);
} else
data->flags = 0;
wdev_unlock(wdev);
return 0;
}
int cfg80211_mgd_wext_siwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
u8 *bssid = ap_addr->sa_data;
int err;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
if (ap_addr->sa_family != ARPHRD_ETHER)
return -EINVAL;
/* automatic mode */
if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
bssid = NULL;
cfg80211_lock_rdev(rdev);
mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
if (wdev->sme_state != CFG80211_SME_IDLE) {
err = 0;
/* both automatic */
if (!bssid && !wdev->wext.connect.bssid)
goto out;
/* fixed already - and no change */
if (wdev->wext.connect.bssid && bssid &&
compare_ether_addr(bssid, wdev->wext.connect.bssid) == 0)
goto out;
err = __cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, false);
if (err)
goto out;
}
if (bssid) {
memcpy(wdev->wext.bssid, bssid, ETH_ALEN);
wdev->wext.connect.bssid = wdev->wext.bssid;
} else
wdev->wext.connect.bssid = NULL;
err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
mutex_unlock(&rdev->devlist_mtx);
cfg80211_unlock_rdev(rdev);
return err;
}
int cfg80211_mgd_wext_giwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
ap_addr->sa_family = ARPHRD_ETHER;
wdev_lock(wdev);
if (wdev->current_bss)
memcpy(ap_addr->sa_data, wdev->current_bss->pub.bssid, ETH_ALEN);
else if (wdev->wext.connect.bssid)
memcpy(ap_addr->sa_data, wdev->wext.connect.bssid, ETH_ALEN);
else
memset(ap_addr->sa_data, 0, ETH_ALEN);
wdev_unlock(wdev);
return 0;
}
int cfg80211_wext_siwgenie(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
u8 *ie = extra;
int ie_len = data->length, err;
if (wdev->iftype != NL80211_IFTYPE_STATION)
return -EOPNOTSUPP;
if (!ie_len)
ie = NULL;
wdev_lock(wdev);
/* no change */
err = 0;
if (wdev->wext.ie_len == ie_len &&
memcmp(wdev->wext.ie, ie, ie_len) == 0)
goto out;
if (ie_len) {
ie = kmemdup(extra, ie_len, GFP_KERNEL);
if (!ie) {
err = -ENOMEM;
goto out;
}
} else
ie = NULL;
kfree(wdev->wext.ie);
wdev->wext.ie = ie;
wdev->wext.ie_len = ie_len;
if (wdev->sme_state != CFG80211_SME_IDLE) {
err = __cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, false);
if (err)
goto out;
}
/* userspace better not think we'll reconnect */
err = 0;
out:
wdev_unlock(wdev);
return err;
}
EXPORT_SYMBOL_GPL(cfg80211_wext_siwgenie);
int cfg80211_wext_siwmlme(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct iw_mlme *mlme = (struct iw_mlme *)extra;
struct cfg80211_registered_device *rdev;
int err;
if (!wdev)
return -EOPNOTSUPP;
rdev = wiphy_to_dev(wdev->wiphy);
if (wdev->iftype != NL80211_IFTYPE_STATION)
return -EINVAL;
if (mlme->addr.sa_family != ARPHRD_ETHER)
return -EINVAL;
wdev_lock(wdev);
switch (mlme->cmd) {
case IW_MLME_DEAUTH:
case IW_MLME_DISASSOC:
err = __cfg80211_disconnect(rdev, dev, mlme->reason_code,
true);
break;
default:
err = -EOPNOTSUPP;
break;
}
wdev_unlock(wdev);
return err;
}
EXPORT_SYMBOL_GPL(cfg80211_wext_siwmlme);