2009-08-07 12:47:46

by Johannes Berg

[permalink] [raw]
Subject: [PATCH] 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 <[email protected]>
---
net/wireless/Makefile | 3 +
net/wireless/chan.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
net/wireless/core.h | 6 +++
net/wireless/ibss.c | 37 +++++++++++++-----
net/wireless/nl80211.c | 49 ++++---------------------
net/wireless/sme.c | 5 ++
net/wireless/wext-compat.c | 55 +++++++++-------------------
net/wireless/wext-compat.h | 3 -
net/wireless/wext-sme.c | 30 ++++++++-------
9 files changed, 171 insertions(+), 105 deletions(-)

--- wireless-testing.orig/net/wireless/Makefile 2009-08-07 11:42:06.000000000 +0200
+++ wireless-testing/net/wireless/Makefile 2009-08-07 11:42:28.000000000 +0200
@@ -5,7 +5,8 @@ obj-$(CONFIG_LIB80211_CRYPT_WEP) += lib8
obj-$(CONFIG_LIB80211_CRYPT_CCMP) += lib80211_crypt_ccmp.o
obj-$(CONFIG_LIB80211_CRYPT_TKIP) += lib80211_crypt_tkip.o

-cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o mlme.o ibss.o sme.o
+cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o
+cfg80211-y += mlme.o ibss.o sme.o chan.o
cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o
cfg80211-$(CONFIG_WIRELESS_EXT) += wext-compat.o wext-sme.o

--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ wireless-testing/net/wireless/chan.c 2009-08-07 12:27:03.000000000 +0200
@@ -0,0 +1,88 @@
+/*
+ * This file contains helper code to handle channel
+ * settings and keeping track of what is possible at
+ * any point in time.
+ *
+ * Copyright 2009 Johannes Berg <[email protected]>
+ */
+
+#include <net/cfg80211.h>
+#include "core.h"
+
+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev)
+{
+ struct wireless_dev *wdev;
+ struct ieee80211_channel *result = NULL;
+
+ ASSERT_RDEV_LOCK(rdev);
+
+ list_for_each_entry(wdev, &rdev->netdev_list, list) {
+ if (wdev == for_wdev)
+ continue;
+
+ /*
+ * Lock manually to tell lockdep about allowed
+ * nesting here if for_wdev->mtx is held already.
+ * This is ok as it's all under rdev lock and
+ * as such can only be done once at any given
+ * time.
+ */
+ mutex_lock_nested(&wdev->mtx, 1);
+ if (wdev->current_bss)
+ result = wdev->current_bss->pub.channel;
+ wdev_unlock(wdev);
+
+ if (result)
+ break;
+ }
+
+ return result;
+}
+
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type)
+{
+ struct ieee80211_channel *chan;
+ struct ieee80211_sta_ht_cap *ht_cap;
+ int result;
+
+ if (rdev_fixed_channel(rdev, NULL))
+ return -EINVAL;
+
+ if (!rdev->ops->set_channel)
+ return -EOPNOTSUPP;
+
+ chan = ieee80211_get_channel(&rdev->wiphy, freq);
+
+ /* Primary channel not allowed */
+ if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+
+ if (channel_type == NL80211_CHAN_HT40MINUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
+ return -EINVAL;
+ else if (channel_type == NL80211_CHAN_HT40PLUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
+ return -EINVAL;
+
+ ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
+
+ if (channel_type != NL80211_CHAN_NO_HT) {
+ if (!ht_cap->ht_supported)
+ return -EINVAL;
+
+ if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
+ ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
+ return -EINVAL;
+ }
+
+ result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
+ if (result)
+ return result;
+
+ rdev->channel = chan;
+
+ return 0;
+}
--- wireless-testing.orig/net/wireless/core.h 2009-08-07 11:42:27.000000000 +0200
+++ wireless-testing/net/wireless/core.h 2009-08-07 11:47:31.000000000 +0200
@@ -368,4 +368,10 @@ void cfg80211_sme_disassoc(struct net_de
void __cfg80211_scan_done(struct work_struct *wk);
void cfg80211_upload_connect_keys(struct wireless_dev *wdev);

+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev);
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type);
+
#endif /* __NET_WIRELESS_CORE_H */
--- wireless-testing.orig/net/wireless/nl80211.c 2009-08-07 11:42:06.000000000 +0200
+++ wireless-testing/net/wireless/nl80211.c 2009-08-07 11:52:58.000000000 +0200
@@ -701,15 +701,8 @@ static int nl80211_set_wiphy(struct sk_b

if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
- struct ieee80211_channel *chan;
- struct ieee80211_sta_ht_cap *ht_cap;
u32 freq;

- if (!rdev->ops->set_channel) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
-
result = -EINVAL;

if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
@@ -723,42 +716,10 @@ static int nl80211_set_wiphy(struct sk_b
}

freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
- chan = ieee80211_get_channel(&rdev->wiphy, freq);
-
- /* Primary channel not allowed */
- if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
- goto bad_res;
-
- if (channel_type == NL80211_CHAN_HT40MINUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40MINUS))
- goto bad_res;
- else if (channel_type == NL80211_CHAN_HT40PLUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40PLUS))
- goto bad_res;
-
- /*
- * At this point we know if that if HT40 was requested
- * we are allowed to use it and the extension channel
- * exists.
- */

- ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
-
- /* no HT capabilities or intolerant */
- if (channel_type != NL80211_CHAN_NO_HT) {
- if (!ht_cap->ht_supported)
- goto bad_res;
- if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
- (ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
- goto bad_res;
- }
-
- result = rdev->ops->set_channel(&rdev->wiphy, chan,
- channel_type);
+ result = rdev_set_freq(rdev, freq, channel_type);
if (result)
goto bad_res;
-
- rdev->channel = chan;
}

changed = 0;
@@ -3453,7 +3414,7 @@ static int nl80211_associate(struct sk_b
struct cfg80211_registered_device *rdev;
struct net_device *dev;
struct cfg80211_crypto_settings crypto;
- struct ieee80211_channel *chan;
+ struct ieee80211_channel *chan, *fixedchan;
const u8 *bssid, *ssid, *ie = NULL, *prev_bssid = NULL;
int err, ssid_len, ie_len = 0;
bool use_mfp = false;
@@ -3496,6 +3457,12 @@ static int nl80211_associate(struct sk_b
goto out;
}

+ fixedchan = rdev_fixed_channel(rdev, NULL);
+ if (fixedchan && chan != fixedchan) {
+ err = -EINVAL;
+ goto out;
+ }
+
ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);

--- wireless-testing.orig/net/wireless/wext-compat.c 2009-08-07 11:42:06.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.c 2009-08-07 11:55:26.000000000 +0200
@@ -267,39 +267,26 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwrange
* @wiphy: the wiphy
* @freq: the wext freq encoding
*
- * Returns a channel, %NULL for auto, or an ERR_PTR for errors!
+ * Returns a frequency, or a negative error code, or 0 for auto.
*/
-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq)
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq)
{
- struct ieee80211_channel *chan;
- int f;
-
/*
- * Parse frequency - return NULL for auto and
+ * Parse frequency - return 0 for auto and
* -EINVAL for impossible things.
*/
if (freq->e == 0) {
if (freq->m < 0)
- return NULL;
- f = ieee80211_channel_to_frequency(freq->m);
+ return 0;
+ return ieee80211_channel_to_frequency(freq->m);
} else {
int i, div = 1000000;
for (i = 0; i < freq->e; i++)
div /= 10;
if (div <= 0)
- return ERR_PTR(-EINVAL);
- f = freq->m / div;
+ return -EINVAL;
+ return freq->m / div;
}
-
- /*
- * Look up channel struct and return -EINVAL when
- * it cannot be found.
- */
- chan = ieee80211_get_channel(wiphy, f);
- if (!chan)
- return ERR_PTR(-EINVAL);
- return chan;
}

int cfg80211_wext_siwrts(struct net_device *dev,
@@ -761,33 +748,29 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwencod

int cfg80211_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ int freq, err;

switch (wdev->iftype) {
case NL80211_IFTYPE_STATION:
- return cfg80211_mgd_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_mgd_wext_siwfreq(dev, info, wextfreq, extra);
case NL80211_IFTYPE_ADHOC:
- return cfg80211_ibss_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_ibss_wext_siwfreq(dev, info, wextfreq, extra);
default:
- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (!chan)
+ freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
+ if (freq < 0)
+ return freq;
+ if (freq == 0)
return -EINVAL;
- if (IS_ERR(chan))
- return PTR_ERR(chan);
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
- if (err)
- return err;
- rdev->channel = chan;
- return 0;
+ cfg80211_lock_rdev(rdev);
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
+ cfg80211_unlock_rdev(rdev);
+ return err;
}
}
-EXPORT_SYMBOL_GPL(cfg80211_wext_siwfreq);

int cfg80211_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
--- wireless-testing.orig/net/wireless/wext-compat.h 2009-08-07 11:42:06.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.h 2009-08-07 11:42:28.000000000 +0200
@@ -42,8 +42,7 @@ int cfg80211_mgd_wext_giwessid(struct ne
struct iw_request_info *info,
struct iw_point *data, char *ssid);

-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq);
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq);


extern const struct iw_handler_def cfg80211_wext_handler;
--- wireless-testing.orig/net/wireless/ibss.c 2009-08-07 11:42:06.000000000 +0200
+++ wireless-testing/net/wireless/ibss.c 2009-08-07 11:57:04.000000000 +0200
@@ -78,10 +78,15 @@ int __cfg80211_join_ibss(struct cfg80211
struct cfg80211_cached_keys *connkeys)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != params->channel)
+ return -EINVAL;
+
if (wdev->ssid_len)
return -EALREADY;

@@ -264,11 +269,11 @@ int cfg80211_ibss_wext_join(struct cfg80

int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ struct iw_freq *wextfreq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
- struct ieee80211_channel *chan;
- int err;
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for ibss! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
@@ -277,14 +282,18 @@ int cfg80211_ibss_wext_siwfreq(struct ne
if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
return -EOPNOTSUPP;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan &&
- (chan->flags & IEEE80211_CHAN_NO_IBSS ||
- chan->flags & IEEE80211_CHAN_DISABLED))
- 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_NO_IBSS ||
+ chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+ }

if (wdev->wext.ibss.channel == chan)
return 0;
@@ -307,9 +316,11 @@ int cfg80211_ibss_wext_siwfreq(struct ne
wdev->wext.ibss.channel_fixed = false;
}

+ cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
wdev_lock(wdev);
err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
wdev_unlock(wdev);
+ cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));

return err;
}
@@ -375,9 +386,11 @@ int cfg80211_ibss_wext_siwessid(struct n
memcpy(wdev->wext.ibss.ssid, ssid, len);
wdev->wext.ibss.ssid_len = len;

+ cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
wdev_lock(wdev);
err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
wdev_unlock(wdev);
+ cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));

return err;
}
@@ -456,9 +469,11 @@ int cfg80211_ibss_wext_siwap(struct net_
} else
wdev->wext.ibss.bssid = NULL;

+ cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
wdev_lock(wdev);
err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
wdev_unlock(wdev);
+ cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));

return err;
}
--- wireless-testing.orig/net/wireless/wext-sme.c 2009-08-07 11:42:27.000000000 +0200
+++ wireless-testing/net/wireless/wext-sme.c 2009-08-07 11:42:28.000000000 +0200
@@ -57,23 +57,28 @@ int cfg80211_mgd_wext_connect(struct cfg

int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan && (chan->flags & IEEE80211_CHAN_DISABLED))
- 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);
wdev_lock(wdev);
@@ -100,11 +105,8 @@ int cfg80211_mgd_wext_siwfreq(struct net
wdev->wext.connect.channel = chan;

/* SSID is not set, we just want to switch channel */
- if (wdev->wext.connect.ssid_len && chan) {
- err = -EOPNOTSUPP;
- if (rdev->ops->set_channel)
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
+ if (chan && !wdev->wext.connect.ssid_len) {
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
goto out;
}

--- wireless-testing.orig/net/wireless/sme.c 2009-08-07 11:49:50.000000000 +0200
+++ wireless-testing/net/wireless/sme.c 2009-08-07 11:50:33.000000000 +0200
@@ -669,6 +669,7 @@ int __cfg80211_connect(struct cfg80211_r
const u8 *prev_bssid)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);
@@ -676,6 +677,10 @@ int __cfg80211_connect(struct cfg80211_r
if (wdev->sme_state != CFG80211_SME_IDLE)
return -EALREADY;

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != connect->channel)
+ return -EINVAL;
+
if (WARN_ON(wdev->connect_keys)) {
kfree(wdev->connect_keys);
wdev->connect_keys = NULL;




2009-08-07 15:22:43

by Johannes Berg

[permalink] [raw]
Subject: [PATCH v4] 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 <[email protected]>
---
v2: * rebase
v3: * fix error code (-EBUSY instead of -EINVAL)
* fix locking (need devlist_mtx instead of rdev mtx)
v4: * use SINGLE_DEPTH_NESTING instead of 1

net/wireless/Makefile | 3 +
net/wireless/chan.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
net/wireless/core.h | 6 +++
net/wireless/ibss.c | 63 ++++++++++++++++++++------------
net/wireless/nl80211.c | 54 ++++++---------------------
net/wireless/sme.c | 9 ++++
net/wireless/wext-compat.c | 55 +++++++++-------------------
net/wireless/wext-compat.h | 3 -
net/wireless/wext-sme.c | 67 ++++++++++++++++++----------------
9 files changed, 215 insertions(+), 133 deletions(-)

--- wireless-testing.orig/net/wireless/Makefile 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/Makefile 2009-08-07 14:50:11.000000000 +0200
@@ -5,7 +5,8 @@ obj-$(CONFIG_LIB80211_CRYPT_WEP) += lib8
obj-$(CONFIG_LIB80211_CRYPT_CCMP) += lib80211_crypt_ccmp.o
obj-$(CONFIG_LIB80211_CRYPT_TKIP) += lib80211_crypt_tkip.o

-cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o mlme.o ibss.o sme.o
+cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o
+cfg80211-y += mlme.o ibss.o sme.o chan.o
cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o
cfg80211-$(CONFIG_WIRELESS_EXT) += wext-compat.o wext-sme.o

--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ wireless-testing/net/wireless/chan.c 2009-08-07 17:20:41.000000000 +0200
@@ -0,0 +1,88 @@
+/*
+ * This file contains helper code to handle channel
+ * settings and keeping track of what is possible at
+ * any point in time.
+ *
+ * Copyright 2009 Johannes Berg <[email protected]>
+ */
+
+#include <net/cfg80211.h>
+#include "core.h"
+
+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev)
+{
+ struct wireless_dev *wdev;
+ struct ieee80211_channel *result = NULL;
+
+ WARN_ON(!mutex_is_locked(&rdev->devlist_mtx));
+
+ list_for_each_entry(wdev, &rdev->netdev_list, list) {
+ if (wdev == for_wdev)
+ continue;
+
+ /*
+ * Lock manually to tell lockdep about allowed
+ * nesting here if for_wdev->mtx is held already.
+ * This is ok as it's all under the rdev devlist
+ * mutex and as such can only be done once at any
+ * given time.
+ */
+ mutex_lock_nested(&wdev->mtx, SINGLE_DEPTH_NESTING);
+ if (wdev->current_bss)
+ result = wdev->current_bss->pub.channel;
+ wdev_unlock(wdev);
+
+ if (result)
+ break;
+ }
+
+ return result;
+}
+
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type)
+{
+ struct ieee80211_channel *chan;
+ struct ieee80211_sta_ht_cap *ht_cap;
+ int result;
+
+ if (rdev_fixed_channel(rdev, NULL))
+ return -EBUSY;
+
+ if (!rdev->ops->set_channel)
+ return -EOPNOTSUPP;
+
+ chan = ieee80211_get_channel(&rdev->wiphy, freq);
+
+ /* Primary channel not allowed */
+ if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+
+ if (channel_type == NL80211_CHAN_HT40MINUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
+ return -EINVAL;
+ else if (channel_type == NL80211_CHAN_HT40PLUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
+ return -EINVAL;
+
+ ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
+
+ if (channel_type != NL80211_CHAN_NO_HT) {
+ if (!ht_cap->ht_supported)
+ return -EINVAL;
+
+ if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
+ ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
+ return -EINVAL;
+ }
+
+ result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
+ if (result)
+ return result;
+
+ rdev->channel = chan;
+
+ return 0;
+}
--- wireless-testing.orig/net/wireless/core.h 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/core.h 2009-08-07 17:20:31.000000000 +0200
@@ -366,4 +366,10 @@ void cfg80211_sme_disassoc(struct net_de
void __cfg80211_scan_done(struct work_struct *wk);
void cfg80211_upload_connect_keys(struct wireless_dev *wdev);

+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev);
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type);
+
#endif /* __NET_WIRELESS_CORE_H */
--- wireless-testing.orig/net/wireless/nl80211.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/nl80211.c 2009-08-07 17:20:30.000000000 +0200
@@ -701,15 +701,8 @@ static int nl80211_set_wiphy(struct sk_b

if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
- struct ieee80211_channel *chan;
- struct ieee80211_sta_ht_cap *ht_cap;
u32 freq;

- if (!rdev->ops->set_channel) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
-
result = -EINVAL;

if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
@@ -723,42 +716,12 @@ static int nl80211_set_wiphy(struct sk_b
}

freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
- chan = ieee80211_get_channel(&rdev->wiphy, freq);
-
- /* Primary channel not allowed */
- if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
- goto bad_res;
-
- if (channel_type == NL80211_CHAN_HT40MINUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40MINUS))
- goto bad_res;
- else if (channel_type == NL80211_CHAN_HT40PLUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40PLUS))
- goto bad_res;
-
- /*
- * At this point we know if that if HT40 was requested
- * we are allowed to use it and the extension channel
- * exists.
- */

- ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
-
- /* no HT capabilities or intolerant */
- if (channel_type != NL80211_CHAN_NO_HT) {
- if (!ht_cap->ht_supported)
- goto bad_res;
- if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
- (ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
- goto bad_res;
- }
-
- result = rdev->ops->set_channel(&rdev->wiphy, chan,
- channel_type);
+ mutex_lock(&rdev->devlist_mtx);
+ result = rdev_set_freq(rdev, freq, channel_type);
+ mutex_unlock(&rdev->devlist_mtx);
if (result)
goto bad_res;
-
- rdev->channel = chan;
}

changed = 0;
@@ -3453,7 +3416,7 @@ static int nl80211_associate(struct sk_b
struct cfg80211_registered_device *rdev;
struct net_device *dev;
struct cfg80211_crypto_settings crypto;
- struct ieee80211_channel *chan;
+ struct ieee80211_channel *chan, *fixedchan;
const u8 *bssid, *ssid, *ie = NULL, *prev_bssid = NULL;
int err, ssid_len, ie_len = 0;
bool use_mfp = false;
@@ -3496,6 +3459,15 @@ static int nl80211_associate(struct sk_b
goto out;
}

+ mutex_lock(&rdev->devlist_mtx);
+ fixedchan = rdev_fixed_channel(rdev, NULL);
+ if (fixedchan && chan != fixedchan) {
+ err = -EBUSY;
+ mutex_unlock(&rdev->devlist_mtx);
+ goto out;
+ }
+ mutex_unlock(&rdev->devlist_mtx);
+
ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);

--- wireless-testing.orig/net/wireless/wext-compat.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.c 2009-08-07 15:38:35.000000000 +0200
@@ -267,39 +267,26 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwrange
* @wiphy: the wiphy
* @freq: the wext freq encoding
*
- * Returns a channel, %NULL for auto, or an ERR_PTR for errors!
+ * Returns a frequency, or a negative error code, or 0 for auto.
*/
-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq)
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq)
{
- struct ieee80211_channel *chan;
- int f;
-
/*
- * Parse frequency - return NULL for auto and
+ * Parse frequency - return 0 for auto and
* -EINVAL for impossible things.
*/
if (freq->e == 0) {
if (freq->m < 0)
- return NULL;
- f = ieee80211_channel_to_frequency(freq->m);
+ return 0;
+ return ieee80211_channel_to_frequency(freq->m);
} else {
int i, div = 1000000;
for (i = 0; i < freq->e; i++)
div /= 10;
if (div <= 0)
- return ERR_PTR(-EINVAL);
- f = freq->m / div;
+ return -EINVAL;
+ return freq->m / div;
}
-
- /*
- * Look up channel struct and return -EINVAL when
- * it cannot be found.
- */
- chan = ieee80211_get_channel(wiphy, f);
- if (!chan)
- return ERR_PTR(-EINVAL);
- return chan;
}

int cfg80211_wext_siwrts(struct net_device *dev,
@@ -761,33 +748,29 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwencod

int cfg80211_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ int freq, err;

switch (wdev->iftype) {
case NL80211_IFTYPE_STATION:
- return cfg80211_mgd_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_mgd_wext_siwfreq(dev, info, wextfreq, extra);
case NL80211_IFTYPE_ADHOC:
- return cfg80211_ibss_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_ibss_wext_siwfreq(dev, info, wextfreq, extra);
default:
- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (!chan)
+ freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
+ if (freq < 0)
+ return freq;
+ if (freq == 0)
return -EINVAL;
- if (IS_ERR(chan))
- return PTR_ERR(chan);
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
- if (err)
- return err;
- rdev->channel = chan;
- return 0;
+ mutex_lock(&rdev->devlist_mtx);
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
+ mutex_unlock(&rdev->devlist_mtx);
+ return err;
}
}
-EXPORT_SYMBOL_GPL(cfg80211_wext_siwfreq);

int cfg80211_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
--- wireless-testing.orig/net/wireless/wext-compat.h 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.h 2009-08-07 14:50:11.000000000 +0200
@@ -42,8 +42,7 @@ int cfg80211_mgd_wext_giwessid(struct ne
struct iw_request_info *info,
struct iw_point *data, char *ssid);

-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq);
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq);


extern const struct iw_handler_def cfg80211_wext_handler;
--- wireless-testing.orig/net/wireless/ibss.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/ibss.c 2009-08-07 15:45:29.000000000 +0200
@@ -78,10 +78,15 @@ int __cfg80211_join_ibss(struct cfg80211
struct cfg80211_cached_keys *connkeys)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != params->channel)
+ return -EBUSY;
+
if (wdev->ssid_len)
return -EALREADY;

@@ -112,9 +117,11 @@ int cfg80211_join_ibss(struct cfg80211_r
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
err = __cfg80211_join_ibss(rdev, dev, params, connkeys);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
@@ -264,27 +271,32 @@ int cfg80211_ibss_wext_join(struct cfg80

int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ struct iw_freq *wextfreq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
- struct ieee80211_channel *chan;
- int err;
+ struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for ibss! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
return -EINVAL;

- if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+ if (!rdev->ops->join_ibss)
return -EOPNOTSUPP;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan &&
- (chan->flags & IEEE80211_CHAN_NO_IBSS ||
- chan->flags & IEEE80211_CHAN_DISABLED))
- 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_NO_IBSS ||
+ chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+ }

if (wdev->wext.ibss.channel == chan)
return 0;
@@ -292,8 +304,7 @@ int cfg80211_ibss_wext_siwfreq(struct ne
wdev_lock(wdev);
err = 0;
if (wdev->ssid_len)
- err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
- dev, true);
+ err = __cfg80211_leave_ibss(rdev, dev, true);
wdev_unlock(wdev);

if (err)
@@ -307,9 +318,11 @@ int cfg80211_ibss_wext_siwfreq(struct ne
wdev->wext.ibss.channel_fixed = false;
}

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
- err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_ibss_wext_join(rdev, wdev);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
@@ -347,6 +360,7 @@ int cfg80211_ibss_wext_siwessid(struct n
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;

@@ -354,14 +368,13 @@ int cfg80211_ibss_wext_siwessid(struct n
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
return -EINVAL;

- if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+ if (!rdev->ops->join_ibss)
return -EOPNOTSUPP;

wdev_lock(wdev);
err = 0;
if (wdev->ssid_len)
- err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
- dev, true);
+ err = __cfg80211_leave_ibss(rdev, dev, true);
wdev_unlock(wdev);

if (err)
@@ -375,9 +388,11 @@ int cfg80211_ibss_wext_siwessid(struct n
memcpy(wdev->wext.ibss.ssid, ssid, len);
wdev->wext.ibss.ssid_len = len;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
- err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_ibss_wext_join(rdev, wdev);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
@@ -414,6 +429,7 @@ int cfg80211_ibss_wext_siwap(struct net_
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;

@@ -421,7 +437,7 @@ int cfg80211_ibss_wext_siwap(struct net_
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
return -EINVAL;

- if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+ if (!rdev->ops->join_ibss)
return -EOPNOTSUPP;

if (ap_addr->sa_family != ARPHRD_ETHER)
@@ -443,8 +459,7 @@ int cfg80211_ibss_wext_siwap(struct net_
wdev_lock(wdev);
err = 0;
if (wdev->ssid_len)
- err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
- dev, true);
+ err = __cfg80211_leave_ibss(rdev, dev, true);
wdev_unlock(wdev);

if (err)
@@ -456,9 +471,11 @@ int cfg80211_ibss_wext_siwap(struct net_
} else
wdev->wext.ibss.bssid = NULL;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
- err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_ibss_wext_join(rdev, wdev);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
--- wireless-testing.orig/net/wireless/wext-sme.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/wext-sme.c 2009-08-07 17:20:31.000000000 +0200
@@ -52,25 +52,31 @@ int cfg80211_mgd_wext_connect(struct cfg

int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan && (chan->flags & IEEE80211_CHAN_DISABLED))
- 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) {
@@ -84,9 +90,8 @@ int cfg80211_mgd_wext_siwfreq(struct net
/* if SSID set, we'll try right again, avoid event */
if (wdev->wext.connect.ssid_len)
event = false;
- err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
- dev, WLAN_REASON_DEAUTH_LEAVING,
- event);
+ err = __cfg80211_disconnect(rdev, dev,
+ WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
@@ -95,17 +100,15 @@ int cfg80211_mgd_wext_siwfreq(struct net
wdev->wext.connect.channel = chan;

/* SSID is not set, we just want to switch channel */
- if (wdev->wext.connect.ssid_len && chan) {
- err = -EOPNOTSUPP;
- if (rdev->ops->set_channel)
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
+ if (chan && !wdev->wext.connect.ssid_len) {
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
goto out;
}

- err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);
cfg80211_unlock_rdev(rdev);
return err;
}
@@ -143,6 +146,7 @@ int cfg80211_mgd_wext_siwessid(struct ne
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;

@@ -157,7 +161,8 @@ int cfg80211_mgd_wext_siwessid(struct ne
if (len > 0 && ssid[len - 1] == '\0')
len--;

- cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
+ cfg80211_lock_rdev(rdev);
+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);

err = 0;
@@ -173,9 +178,8 @@ int cfg80211_mgd_wext_siwessid(struct ne
/* if SSID set now, we'll try to connect, avoid event */
if (len)
event = false;
- err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
- dev, WLAN_REASON_DEAUTH_LEAVING,
- event);
+ err = __cfg80211_disconnect(rdev, dev,
+ WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
@@ -186,10 +190,11 @@ int cfg80211_mgd_wext_siwessid(struct ne

wdev->wext.connect.crypto.control_port = false;

- err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
- cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));
+ mutex_unlock(&rdev->devlist_mtx);
+ cfg80211_unlock_rdev(rdev);
return err;
}

@@ -230,6 +235,7 @@ int cfg80211_mgd_wext_siwap(struct net_d
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;

@@ -244,7 +250,8 @@ int cfg80211_mgd_wext_siwap(struct net_d
if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
bssid = NULL;

- cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
+ cfg80211_lock_rdev(rdev);
+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);

if (wdev->sme_state != CFG80211_SME_IDLE) {
@@ -258,9 +265,8 @@ int cfg80211_mgd_wext_siwap(struct net_d
compare_ether_addr(bssid, wdev->wext.connect.bssid) == 0)
goto out;

- err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
- dev, WLAN_REASON_DEAUTH_LEAVING,
- false);
+ err = __cfg80211_disconnect(rdev, dev,
+ WLAN_REASON_DEAUTH_LEAVING, false);
if (err)
goto out;
}
@@ -271,10 +277,11 @@ int cfg80211_mgd_wext_siwap(struct net_d
} else
wdev->wext.connect.bssid = NULL;

- err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
- cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));
+ mutex_unlock(&rdev->devlist_mtx);
+ cfg80211_unlock_rdev(rdev);
return err;
}

--- wireless-testing.orig/net/wireless/sme.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/sme.c 2009-08-07 17:20:31.000000000 +0200
@@ -256,9 +256,11 @@ void cfg80211_sme_scan_done(struct net_d
{
struct wireless_dev *wdev = dev->ieee80211_ptr;

+ mutex_lock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
wdev_lock(wdev);
__cfg80211_sme_scan_done(dev);
wdev_unlock(wdev);
+ mutex_unlock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
}

void cfg80211_sme_rx_auth(struct net_device *dev,
@@ -644,6 +646,7 @@ int __cfg80211_connect(struct cfg80211_r
struct cfg80211_cached_keys *connkeys)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);
@@ -651,6 +654,10 @@ int __cfg80211_connect(struct cfg80211_r
if (wdev->sme_state != CFG80211_SME_IDLE)
return -EALREADY;

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != connect->channel)
+ return -EBUSY;
+
if (WARN_ON(wdev->connect_keys)) {
kfree(wdev->connect_keys);
wdev->connect_keys = NULL;
@@ -771,9 +778,11 @@ int cfg80211_connect(struct cfg80211_reg
{
int err;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(dev->ieee80211_ptr);
err = __cfg80211_connect(rdev, dev, connect, connkeys);
wdev_unlock(dev->ieee80211_ptr);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}



2009-08-08 19:34:37

by Larry Finger

[permalink] [raw]
Subject: Re: [PATCH v4] cfg80211: validate channel settings across interfaces

reinette chatre wrote:
> Hi Johannes,
>
> This patch is now in wireless-testing and it is causing a problem for
> me. This was determined using bisect.
>
> I am able to bring the interface up and scan, but when I try to
> associate I get a hang.
>
> For example, when I run:
> $ iwconfig wlan0 channel <ch> essid <essid>
>
> then the command prompt never returns and system becomes progressively
> unresponsive. The logs do not contain any details of the problem.

I have the same problem here as well.

Larry


2009-08-07 13:49:22

by Johannes Berg

[permalink] [raw]
Subject: [PATCH v3] 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 <[email protected]>
---
v2: * rebase
v3: * fix error code (-EBUSY instead of -EINVAL)
* fix locking (need devlist_mtx instead of rdev mtx)

net/wireless/Makefile | 3 +
net/wireless/chan.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
net/wireless/core.h | 6 +++
net/wireless/ibss.c | 63 ++++++++++++++++++++------------
net/wireless/nl80211.c | 54 ++++++---------------------
net/wireless/sme.c | 9 ++++
net/wireless/wext-compat.c | 55 +++++++++-------------------
net/wireless/wext-compat.h | 3 -
net/wireless/wext-sme.c | 67 ++++++++++++++++++----------------
9 files changed, 215 insertions(+), 133 deletions(-)

--- wireless-testing.orig/net/wireless/Makefile 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/Makefile 2009-08-07 14:50:11.000000000 +0200
@@ -5,7 +5,8 @@ obj-$(CONFIG_LIB80211_CRYPT_WEP) += lib8
obj-$(CONFIG_LIB80211_CRYPT_CCMP) += lib80211_crypt_ccmp.o
obj-$(CONFIG_LIB80211_CRYPT_TKIP) += lib80211_crypt_tkip.o

-cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o mlme.o ibss.o sme.o
+cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o
+cfg80211-y += mlme.o ibss.o sme.o chan.o
cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o
cfg80211-$(CONFIG_WIRELESS_EXT) += wext-compat.o wext-sme.o

--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ wireless-testing/net/wireless/chan.c 2009-08-07 15:45:10.000000000 +0200
@@ -0,0 +1,88 @@
+/*
+ * This file contains helper code to handle channel
+ * settings and keeping track of what is possible at
+ * any point in time.
+ *
+ * Copyright 2009 Johannes Berg <[email protected]>
+ */
+
+#include <net/cfg80211.h>
+#include "core.h"
+
+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev)
+{
+ struct wireless_dev *wdev;
+ struct ieee80211_channel *result = NULL;
+
+ WARN_ON(!mutex_is_locked(&rdev->devlist_mtx));
+
+ list_for_each_entry(wdev, &rdev->netdev_list, list) {
+ if (wdev == for_wdev)
+ continue;
+
+ /*
+ * Lock manually to tell lockdep about allowed
+ * nesting here if for_wdev->mtx is held already.
+ * This is ok as it's all under the rdev devlist
+ * mutex and as such can only be done once at any
+ * given time.
+ */
+ mutex_lock_nested(&wdev->mtx, 1);
+ if (wdev->current_bss)
+ result = wdev->current_bss->pub.channel;
+ wdev_unlock(wdev);
+
+ if (result)
+ break;
+ }
+
+ return result;
+}
+
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type)
+{
+ struct ieee80211_channel *chan;
+ struct ieee80211_sta_ht_cap *ht_cap;
+ int result;
+
+ if (rdev_fixed_channel(rdev, NULL))
+ return -EBUSY;
+
+ if (!rdev->ops->set_channel)
+ return -EOPNOTSUPP;
+
+ chan = ieee80211_get_channel(&rdev->wiphy, freq);
+
+ /* Primary channel not allowed */
+ if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+
+ if (channel_type == NL80211_CHAN_HT40MINUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
+ return -EINVAL;
+ else if (channel_type == NL80211_CHAN_HT40PLUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
+ return -EINVAL;
+
+ ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
+
+ if (channel_type != NL80211_CHAN_NO_HT) {
+ if (!ht_cap->ht_supported)
+ return -EINVAL;
+
+ if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
+ ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
+ return -EINVAL;
+ }
+
+ result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
+ if (result)
+ return result;
+
+ rdev->channel = chan;
+
+ return 0;
+}
--- wireless-testing.orig/net/wireless/core.h 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/core.h 2009-08-07 15:23:49.000000000 +0200
@@ -366,4 +366,10 @@ void cfg80211_sme_disassoc(struct net_de
void __cfg80211_scan_done(struct work_struct *wk);
void cfg80211_upload_connect_keys(struct wireless_dev *wdev);

+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev);
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type);
+
#endif /* __NET_WIRELESS_CORE_H */
--- wireless-testing.orig/net/wireless/nl80211.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/nl80211.c 2009-08-07 15:46:38.000000000 +0200
@@ -701,15 +701,8 @@ static int nl80211_set_wiphy(struct sk_b

if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
- struct ieee80211_channel *chan;
- struct ieee80211_sta_ht_cap *ht_cap;
u32 freq;

- if (!rdev->ops->set_channel) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
-
result = -EINVAL;

if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
@@ -723,42 +716,12 @@ static int nl80211_set_wiphy(struct sk_b
}

freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
- chan = ieee80211_get_channel(&rdev->wiphy, freq);
-
- /* Primary channel not allowed */
- if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
- goto bad_res;
-
- if (channel_type == NL80211_CHAN_HT40MINUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40MINUS))
- goto bad_res;
- else if (channel_type == NL80211_CHAN_HT40PLUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40PLUS))
- goto bad_res;
-
- /*
- * At this point we know if that if HT40 was requested
- * we are allowed to use it and the extension channel
- * exists.
- */

- ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
-
- /* no HT capabilities or intolerant */
- if (channel_type != NL80211_CHAN_NO_HT) {
- if (!ht_cap->ht_supported)
- goto bad_res;
- if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
- (ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
- goto bad_res;
- }
-
- result = rdev->ops->set_channel(&rdev->wiphy, chan,
- channel_type);
+ mutex_lock(&rdev->devlist_mtx);
+ result = rdev_set_freq(rdev, freq, channel_type);
+ mutex_unlock(&rdev->devlist_mtx);
if (result)
goto bad_res;
-
- rdev->channel = chan;
}

changed = 0;
@@ -3453,7 +3416,7 @@ static int nl80211_associate(struct sk_b
struct cfg80211_registered_device *rdev;
struct net_device *dev;
struct cfg80211_crypto_settings crypto;
- struct ieee80211_channel *chan;
+ struct ieee80211_channel *chan, *fixedchan;
const u8 *bssid, *ssid, *ie = NULL, *prev_bssid = NULL;
int err, ssid_len, ie_len = 0;
bool use_mfp = false;
@@ -3496,6 +3459,15 @@ static int nl80211_associate(struct sk_b
goto out;
}

+ mutex_lock(&rdev->devlist_mtx);
+ fixedchan = rdev_fixed_channel(rdev, NULL);
+ if (fixedchan && chan != fixedchan) {
+ err = -EBUSY;
+ mutex_unlock(&rdev->devlist_mtx);
+ goto out;
+ }
+ mutex_unlock(&rdev->devlist_mtx);
+
ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);

--- wireless-testing.orig/net/wireless/wext-compat.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.c 2009-08-07 15:38:35.000000000 +0200
@@ -267,39 +267,26 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwrange
* @wiphy: the wiphy
* @freq: the wext freq encoding
*
- * Returns a channel, %NULL for auto, or an ERR_PTR for errors!
+ * Returns a frequency, or a negative error code, or 0 for auto.
*/
-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq)
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq)
{
- struct ieee80211_channel *chan;
- int f;
-
/*
- * Parse frequency - return NULL for auto and
+ * Parse frequency - return 0 for auto and
* -EINVAL for impossible things.
*/
if (freq->e == 0) {
if (freq->m < 0)
- return NULL;
- f = ieee80211_channel_to_frequency(freq->m);
+ return 0;
+ return ieee80211_channel_to_frequency(freq->m);
} else {
int i, div = 1000000;
for (i = 0; i < freq->e; i++)
div /= 10;
if (div <= 0)
- return ERR_PTR(-EINVAL);
- f = freq->m / div;
+ return -EINVAL;
+ return freq->m / div;
}
-
- /*
- * Look up channel struct and return -EINVAL when
- * it cannot be found.
- */
- chan = ieee80211_get_channel(wiphy, f);
- if (!chan)
- return ERR_PTR(-EINVAL);
- return chan;
}

int cfg80211_wext_siwrts(struct net_device *dev,
@@ -761,33 +748,29 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwencod

int cfg80211_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ int freq, err;

switch (wdev->iftype) {
case NL80211_IFTYPE_STATION:
- return cfg80211_mgd_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_mgd_wext_siwfreq(dev, info, wextfreq, extra);
case NL80211_IFTYPE_ADHOC:
- return cfg80211_ibss_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_ibss_wext_siwfreq(dev, info, wextfreq, extra);
default:
- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (!chan)
+ freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
+ if (freq < 0)
+ return freq;
+ if (freq == 0)
return -EINVAL;
- if (IS_ERR(chan))
- return PTR_ERR(chan);
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
- if (err)
- return err;
- rdev->channel = chan;
- return 0;
+ mutex_lock(&rdev->devlist_mtx);
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
+ mutex_unlock(&rdev->devlist_mtx);
+ return err;
}
}
-EXPORT_SYMBOL_GPL(cfg80211_wext_siwfreq);

int cfg80211_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
--- wireless-testing.orig/net/wireless/wext-compat.h 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.h 2009-08-07 14:50:11.000000000 +0200
@@ -42,8 +42,7 @@ int cfg80211_mgd_wext_giwessid(struct ne
struct iw_request_info *info,
struct iw_point *data, char *ssid);

-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq);
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq);


extern const struct iw_handler_def cfg80211_wext_handler;
--- wireless-testing.orig/net/wireless/ibss.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/ibss.c 2009-08-07 15:45:29.000000000 +0200
@@ -78,10 +78,15 @@ int __cfg80211_join_ibss(struct cfg80211
struct cfg80211_cached_keys *connkeys)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != params->channel)
+ return -EBUSY;
+
if (wdev->ssid_len)
return -EALREADY;

@@ -112,9 +117,11 @@ int cfg80211_join_ibss(struct cfg80211_r
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
err = __cfg80211_join_ibss(rdev, dev, params, connkeys);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
@@ -264,27 +271,32 @@ int cfg80211_ibss_wext_join(struct cfg80

int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ struct iw_freq *wextfreq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
- struct ieee80211_channel *chan;
- int err;
+ struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for ibss! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
return -EINVAL;

- if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+ if (!rdev->ops->join_ibss)
return -EOPNOTSUPP;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan &&
- (chan->flags & IEEE80211_CHAN_NO_IBSS ||
- chan->flags & IEEE80211_CHAN_DISABLED))
- 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_NO_IBSS ||
+ chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+ }

if (wdev->wext.ibss.channel == chan)
return 0;
@@ -292,8 +304,7 @@ int cfg80211_ibss_wext_siwfreq(struct ne
wdev_lock(wdev);
err = 0;
if (wdev->ssid_len)
- err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
- dev, true);
+ err = __cfg80211_leave_ibss(rdev, dev, true);
wdev_unlock(wdev);

if (err)
@@ -307,9 +318,11 @@ int cfg80211_ibss_wext_siwfreq(struct ne
wdev->wext.ibss.channel_fixed = false;
}

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
- err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_ibss_wext_join(rdev, wdev);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
@@ -347,6 +360,7 @@ int cfg80211_ibss_wext_siwessid(struct n
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;

@@ -354,14 +368,13 @@ int cfg80211_ibss_wext_siwessid(struct n
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
return -EINVAL;

- if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+ if (!rdev->ops->join_ibss)
return -EOPNOTSUPP;

wdev_lock(wdev);
err = 0;
if (wdev->ssid_len)
- err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
- dev, true);
+ err = __cfg80211_leave_ibss(rdev, dev, true);
wdev_unlock(wdev);

if (err)
@@ -375,9 +388,11 @@ int cfg80211_ibss_wext_siwessid(struct n
memcpy(wdev->wext.ibss.ssid, ssid, len);
wdev->wext.ibss.ssid_len = len;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
- err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_ibss_wext_join(rdev, wdev);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
@@ -414,6 +429,7 @@ int cfg80211_ibss_wext_siwap(struct net_
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;

@@ -421,7 +437,7 @@ int cfg80211_ibss_wext_siwap(struct net_
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
return -EINVAL;

- if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
+ if (!rdev->ops->join_ibss)
return -EOPNOTSUPP;

if (ap_addr->sa_family != ARPHRD_ETHER)
@@ -443,8 +459,7 @@ int cfg80211_ibss_wext_siwap(struct net_
wdev_lock(wdev);
err = 0;
if (wdev->ssid_len)
- err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
- dev, true);
+ err = __cfg80211_leave_ibss(rdev, dev, true);
wdev_unlock(wdev);

if (err)
@@ -456,9 +471,11 @@ int cfg80211_ibss_wext_siwap(struct net_
} else
wdev->wext.ibss.bssid = NULL;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);
- err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_ibss_wext_join(rdev, wdev);
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
--- wireless-testing.orig/net/wireless/wext-sme.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/wext-sme.c 2009-08-07 15:42:12.000000000 +0200
@@ -52,25 +52,31 @@ int cfg80211_mgd_wext_connect(struct cfg

int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan && (chan->flags & IEEE80211_CHAN_DISABLED))
- 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) {
@@ -84,9 +90,8 @@ int cfg80211_mgd_wext_siwfreq(struct net
/* if SSID set, we'll try right again, avoid event */
if (wdev->wext.connect.ssid_len)
event = false;
- err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
- dev, WLAN_REASON_DEAUTH_LEAVING,
- event);
+ err = __cfg80211_disconnect(rdev, dev,
+ WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
@@ -95,17 +100,15 @@ int cfg80211_mgd_wext_siwfreq(struct net
wdev->wext.connect.channel = chan;

/* SSID is not set, we just want to switch channel */
- if (wdev->wext.connect.ssid_len && chan) {
- err = -EOPNOTSUPP;
- if (rdev->ops->set_channel)
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
+ if (chan && !wdev->wext.connect.ssid_len) {
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
goto out;
}

- err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
+ mutex_unlock(&rdev->devlist_mtx);
cfg80211_unlock_rdev(rdev);
return err;
}
@@ -143,6 +146,7 @@ int cfg80211_mgd_wext_siwessid(struct ne
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;

@@ -157,7 +161,8 @@ int cfg80211_mgd_wext_siwessid(struct ne
if (len > 0 && ssid[len - 1] == '\0')
len--;

- cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
+ cfg80211_lock_rdev(rdev);
+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);

err = 0;
@@ -173,9 +178,8 @@ int cfg80211_mgd_wext_siwessid(struct ne
/* if SSID set now, we'll try to connect, avoid event */
if (len)
event = false;
- err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
- dev, WLAN_REASON_DEAUTH_LEAVING,
- event);
+ err = __cfg80211_disconnect(rdev, dev,
+ WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
@@ -186,10 +190,11 @@ int cfg80211_mgd_wext_siwessid(struct ne

wdev->wext.connect.crypto.control_port = false;

- err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
- cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));
+ mutex_unlock(&rdev->devlist_mtx);
+ cfg80211_unlock_rdev(rdev);
return err;
}

@@ -230,6 +235,7 @@ int cfg80211_mgd_wext_siwap(struct net_d
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;

@@ -244,7 +250,8 @@ int cfg80211_mgd_wext_siwap(struct net_d
if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
bssid = NULL;

- cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
+ cfg80211_lock_rdev(rdev);
+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(wdev);

if (wdev->sme_state != CFG80211_SME_IDLE) {
@@ -258,9 +265,8 @@ int cfg80211_mgd_wext_siwap(struct net_d
compare_ether_addr(bssid, wdev->wext.connect.bssid) == 0)
goto out;

- err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
- dev, WLAN_REASON_DEAUTH_LEAVING,
- false);
+ err = __cfg80211_disconnect(rdev, dev,
+ WLAN_REASON_DEAUTH_LEAVING, false);
if (err)
goto out;
}
@@ -271,10 +277,11 @@ int cfg80211_mgd_wext_siwap(struct net_d
} else
wdev->wext.connect.bssid = NULL;

- err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
+ err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
- cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));
+ mutex_unlock(&rdev->devlist_mtx);
+ cfg80211_unlock_rdev(rdev);
return err;
}

--- wireless-testing.orig/net/wireless/sme.c 2009-08-07 14:50:09.000000000 +0200
+++ wireless-testing/net/wireless/sme.c 2009-08-07 15:45:38.000000000 +0200
@@ -256,9 +256,11 @@ void cfg80211_sme_scan_done(struct net_d
{
struct wireless_dev *wdev = dev->ieee80211_ptr;

+ mutex_lock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
wdev_lock(wdev);
__cfg80211_sme_scan_done(dev);
wdev_unlock(wdev);
+ mutex_unlock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
}

void cfg80211_sme_rx_auth(struct net_device *dev,
@@ -644,6 +646,7 @@ int __cfg80211_connect(struct cfg80211_r
struct cfg80211_cached_keys *connkeys)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);
@@ -651,6 +654,10 @@ int __cfg80211_connect(struct cfg80211_r
if (wdev->sme_state != CFG80211_SME_IDLE)
return -EALREADY;

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != connect->channel)
+ return -EBUSY;
+
if (WARN_ON(wdev->connect_keys)) {
kfree(wdev->connect_keys);
wdev->connect_keys = NULL;
@@ -771,9 +778,11 @@ int cfg80211_connect(struct cfg80211_reg
{
int err;

+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(dev->ieee80211_ptr);
err = __cfg80211_connect(rdev, dev, connect, connkeys);
wdev_unlock(dev->ieee80211_ptr);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}



2009-08-08 06:19:55

by Reinette Chatre

[permalink] [raw]
Subject: Re: [PATCH v4] cfg80211: validate channel settings across interfaces

Hi Johannes,

This patch is now in wireless-testing and it is causing a problem for
me. This was determined using bisect.

I am able to bring the interface up and scan, but when I try to
associate I get a hang.

For example, when I run:
$ iwconfig wlan0 channel <ch> essid <essid>

then the command prompt never returns and system becomes progressively
unresponsive. The logs do not contain any details of the problem.

Reinette


On Fri, 2009-08-07 at 08:22 -0700, Johannes Berg wrote:
> 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 <[email protected]>
> ---
> v2: * rebase
> v3: * fix error code (-EBUSY instead of -EINVAL)
> * fix locking (need devlist_mtx instead of rdev mtx)
> v4: * use SINGLE_DEPTH_NESTING instead of 1
>
> net/wireless/Makefile | 3 +
> net/wireless/chan.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
> net/wireless/core.h | 6 +++
> net/wireless/ibss.c | 63 ++++++++++++++++++++------------
> net/wireless/nl80211.c | 54 ++++++---------------------
> net/wireless/sme.c | 9 ++++
> net/wireless/wext-compat.c | 55 +++++++++-------------------
> net/wireless/wext-compat.h | 3 -
> net/wireless/wext-sme.c | 67 ++++++++++++++++++----------------
> 9 files changed, 215 insertions(+), 133 deletions(-)
>
> --- wireless-testing.orig/net/wireless/Makefile 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/Makefile 2009-08-07 14:50:11.000000000 +0200
> @@ -5,7 +5,8 @@ obj-$(CONFIG_LIB80211_CRYPT_WEP) += lib8
> obj-$(CONFIG_LIB80211_CRYPT_CCMP) += lib80211_crypt_ccmp.o
> obj-$(CONFIG_LIB80211_CRYPT_TKIP) += lib80211_crypt_tkip.o
>
> -cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o mlme.o ibss.o sme.o
> +cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o
> +cfg80211-y += mlme.o ibss.o sme.o chan.o
> cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o
> cfg80211-$(CONFIG_WIRELESS_EXT) += wext-compat.o wext-sme.o
>
> --- /dev/null 1970-01-01 00:00:00.000000000 +0000
> +++ wireless-testing/net/wireless/chan.c 2009-08-07 17:20:41.000000000 +0200
> @@ -0,0 +1,88 @@
> +/*
> + * This file contains helper code to handle channel
> + * settings and keeping track of what is possible at
> + * any point in time.
> + *
> + * Copyright 2009 Johannes Berg <[email protected]>
> + */
> +
> +#include <net/cfg80211.h>
> +#include "core.h"
> +
> +struct ieee80211_channel *
> +rdev_fixed_channel(struct cfg80211_registered_device *rdev,
> + struct wireless_dev *for_wdev)
> +{
> + struct wireless_dev *wdev;
> + struct ieee80211_channel *result = NULL;
> +
> + WARN_ON(!mutex_is_locked(&rdev->devlist_mtx));
> +
> + list_for_each_entry(wdev, &rdev->netdev_list, list) {
> + if (wdev == for_wdev)
> + continue;
> +
> + /*
> + * Lock manually to tell lockdep about allowed
> + * nesting here if for_wdev->mtx is held already.
> + * This is ok as it's all under the rdev devlist
> + * mutex and as such can only be done once at any
> + * given time.
> + */
> + mutex_lock_nested(&wdev->mtx, SINGLE_DEPTH_NESTING);
> + if (wdev->current_bss)
> + result = wdev->current_bss->pub.channel;
> + wdev_unlock(wdev);
> +
> + if (result)
> + break;
> + }
> +
> + return result;
> +}
> +
> +int rdev_set_freq(struct cfg80211_registered_device *rdev,
> + int freq, enum nl80211_channel_type channel_type)
> +{
> + struct ieee80211_channel *chan;
> + struct ieee80211_sta_ht_cap *ht_cap;
> + int result;
> +
> + if (rdev_fixed_channel(rdev, NULL))
> + return -EBUSY;
> +
> + if (!rdev->ops->set_channel)
> + return -EOPNOTSUPP;
> +
> + chan = ieee80211_get_channel(&rdev->wiphy, freq);
> +
> + /* Primary channel not allowed */
> + if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
> + return -EINVAL;
> +
> + if (channel_type == NL80211_CHAN_HT40MINUS &&
> + chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
> + return -EINVAL;
> + else if (channel_type == NL80211_CHAN_HT40PLUS &&
> + chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
> + return -EINVAL;
> +
> + ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
> +
> + if (channel_type != NL80211_CHAN_NO_HT) {
> + if (!ht_cap->ht_supported)
> + return -EINVAL;
> +
> + if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
> + ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
> + return -EINVAL;
> + }
> +
> + result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
> + if (result)
> + return result;
> +
> + rdev->channel = chan;
> +
> + return 0;
> +}
> --- wireless-testing.orig/net/wireless/core.h 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/core.h 2009-08-07 17:20:31.000000000 +0200
> @@ -366,4 +366,10 @@ void cfg80211_sme_disassoc(struct net_de
> void __cfg80211_scan_done(struct work_struct *wk);
> void cfg80211_upload_connect_keys(struct wireless_dev *wdev);
>
> +struct ieee80211_channel *
> +rdev_fixed_channel(struct cfg80211_registered_device *rdev,
> + struct wireless_dev *for_wdev);
> +int rdev_set_freq(struct cfg80211_registered_device *rdev,
> + int freq, enum nl80211_channel_type channel_type);
> +
> #endif /* __NET_WIRELESS_CORE_H */
> --- wireless-testing.orig/net/wireless/nl80211.c 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/nl80211.c 2009-08-07 17:20:30.000000000 +0200
> @@ -701,15 +701,8 @@ static int nl80211_set_wiphy(struct sk_b
>
> if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
> enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
> - struct ieee80211_channel *chan;
> - struct ieee80211_sta_ht_cap *ht_cap;
> u32 freq;
>
> - if (!rdev->ops->set_channel) {
> - result = -EOPNOTSUPP;
> - goto bad_res;
> - }
> -
> result = -EINVAL;
>
> if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
> @@ -723,42 +716,12 @@ static int nl80211_set_wiphy(struct sk_b
> }
>
> freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
> - chan = ieee80211_get_channel(&rdev->wiphy, freq);
> -
> - /* Primary channel not allowed */
> - if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
> - goto bad_res;
> -
> - if (channel_type == NL80211_CHAN_HT40MINUS &&
> - (chan->flags & IEEE80211_CHAN_NO_HT40MINUS))
> - goto bad_res;
> - else if (channel_type == NL80211_CHAN_HT40PLUS &&
> - (chan->flags & IEEE80211_CHAN_NO_HT40PLUS))
> - goto bad_res;
> -
> - /*
> - * At this point we know if that if HT40 was requested
> - * we are allowed to use it and the extension channel
> - * exists.
> - */
>
> - ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
> -
> - /* no HT capabilities or intolerant */
> - if (channel_type != NL80211_CHAN_NO_HT) {
> - if (!ht_cap->ht_supported)
> - goto bad_res;
> - if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
> - (ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
> - goto bad_res;
> - }
> -
> - result = rdev->ops->set_channel(&rdev->wiphy, chan,
> - channel_type);
> + mutex_lock(&rdev->devlist_mtx);
> + result = rdev_set_freq(rdev, freq, channel_type);
> + mutex_unlock(&rdev->devlist_mtx);
> if (result)
> goto bad_res;
> -
> - rdev->channel = chan;
> }
>
> changed = 0;
> @@ -3453,7 +3416,7 @@ static int nl80211_associate(struct sk_b
> struct cfg80211_registered_device *rdev;
> struct net_device *dev;
> struct cfg80211_crypto_settings crypto;
> - struct ieee80211_channel *chan;
> + struct ieee80211_channel *chan, *fixedchan;
> const u8 *bssid, *ssid, *ie = NULL, *prev_bssid = NULL;
> int err, ssid_len, ie_len = 0;
> bool use_mfp = false;
> @@ -3496,6 +3459,15 @@ static int nl80211_associate(struct sk_b
> goto out;
> }
>
> + mutex_lock(&rdev->devlist_mtx);
> + fixedchan = rdev_fixed_channel(rdev, NULL);
> + if (fixedchan && chan != fixedchan) {
> + err = -EBUSY;
> + mutex_unlock(&rdev->devlist_mtx);
> + goto out;
> + }
> + mutex_unlock(&rdev->devlist_mtx);
> +
> ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
> ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);
>
> --- wireless-testing.orig/net/wireless/wext-compat.c 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/wext-compat.c 2009-08-07 15:38:35.000000000 +0200
> @@ -267,39 +267,26 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwrange
> * @wiphy: the wiphy
> * @freq: the wext freq encoding
> *
> - * Returns a channel, %NULL for auto, or an ERR_PTR for errors!
> + * Returns a frequency, or a negative error code, or 0 for auto.
> */
> -struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
> - struct iw_freq *freq)
> +int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq)
> {
> - struct ieee80211_channel *chan;
> - int f;
> -
> /*
> - * Parse frequency - return NULL for auto and
> + * Parse frequency - return 0 for auto and
> * -EINVAL for impossible things.
> */
> if (freq->e == 0) {
> if (freq->m < 0)
> - return NULL;
> - f = ieee80211_channel_to_frequency(freq->m);
> + return 0;
> + return ieee80211_channel_to_frequency(freq->m);
> } else {
> int i, div = 1000000;
> for (i = 0; i < freq->e; i++)
> div /= 10;
> if (div <= 0)
> - return ERR_PTR(-EINVAL);
> - f = freq->m / div;
> + return -EINVAL;
> + return freq->m / div;
> }
> -
> - /*
> - * Look up channel struct and return -EINVAL when
> - * it cannot be found.
> - */
> - chan = ieee80211_get_channel(wiphy, f);
> - if (!chan)
> - return ERR_PTR(-EINVAL);
> - return chan;
> }
>
> int cfg80211_wext_siwrts(struct net_device *dev,
> @@ -761,33 +748,29 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwencod
>
> int cfg80211_wext_siwfreq(struct net_device *dev,
> struct iw_request_info *info,
> - struct iw_freq *freq, char *extra)
> + 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;
> - int err;
> + int freq, err;
>
> switch (wdev->iftype) {
> case NL80211_IFTYPE_STATION:
> - return cfg80211_mgd_wext_siwfreq(dev, info, freq, extra);
> + return cfg80211_mgd_wext_siwfreq(dev, info, wextfreq, extra);
> case NL80211_IFTYPE_ADHOC:
> - return cfg80211_ibss_wext_siwfreq(dev, info, freq, extra);
> + return cfg80211_ibss_wext_siwfreq(dev, info, wextfreq, extra);
> default:
> - chan = cfg80211_wext_freq(wdev->wiphy, freq);
> - if (!chan)
> + freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
> + if (freq < 0)
> + return freq;
> + if (freq == 0)
> return -EINVAL;
> - if (IS_ERR(chan))
> - return PTR_ERR(chan);
> - err = rdev->ops->set_channel(wdev->wiphy, chan,
> - NL80211_CHAN_NO_HT);
> - if (err)
> - return err;
> - rdev->channel = chan;
> - return 0;
> + mutex_lock(&rdev->devlist_mtx);
> + err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
> + mutex_unlock(&rdev->devlist_mtx);
> + return err;
> }
> }
> -EXPORT_SYMBOL_GPL(cfg80211_wext_siwfreq);
>
> int cfg80211_wext_giwfreq(struct net_device *dev,
> struct iw_request_info *info,
> --- wireless-testing.orig/net/wireless/wext-compat.h 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/wext-compat.h 2009-08-07 14:50:11.000000000 +0200
> @@ -42,8 +42,7 @@ int cfg80211_mgd_wext_giwessid(struct ne
> struct iw_request_info *info,
> struct iw_point *data, char *ssid);
>
> -struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
> - struct iw_freq *freq);
> +int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq);
>
>
> extern const struct iw_handler_def cfg80211_wext_handler;
> --- wireless-testing.orig/net/wireless/ibss.c 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/ibss.c 2009-08-07 15:45:29.000000000 +0200
> @@ -78,10 +78,15 @@ int __cfg80211_join_ibss(struct cfg80211
> struct cfg80211_cached_keys *connkeys)
> {
> struct wireless_dev *wdev = dev->ieee80211_ptr;
> + struct ieee80211_channel *chan;
> int err;
>
> ASSERT_WDEV_LOCK(wdev);
>
> + chan = rdev_fixed_channel(rdev, wdev);
> + if (chan && chan != params->channel)
> + return -EBUSY;
> +
> if (wdev->ssid_len)
> return -EALREADY;
>
> @@ -112,9 +117,11 @@ int cfg80211_join_ibss(struct cfg80211_r
> struct wireless_dev *wdev = dev->ieee80211_ptr;
> int err;
>
> + mutex_lock(&rdev->devlist_mtx);
> wdev_lock(wdev);
> err = __cfg80211_join_ibss(rdev, dev, params, connkeys);
> wdev_unlock(wdev);
> + mutex_unlock(&rdev->devlist_mtx);
>
> return err;
> }
> @@ -264,27 +271,32 @@ int cfg80211_ibss_wext_join(struct cfg80
>
> int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
> struct iw_request_info *info,
> - struct iw_freq *freq, char *extra)
> + struct iw_freq *wextfreq, char *extra)
> {
> struct wireless_dev *wdev = dev->ieee80211_ptr;
> - struct ieee80211_channel *chan;
> - int err;
> + struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
> + struct ieee80211_channel *chan = NULL;
> + int err, freq;
>
> /* call only for ibss! */
> if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
> return -EINVAL;
>
> - if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
> + if (!rdev->ops->join_ibss)
> return -EOPNOTSUPP;
>
> - chan = cfg80211_wext_freq(wdev->wiphy, freq);
> - if (chan && IS_ERR(chan))
> - return PTR_ERR(chan);
> -
> - if (chan &&
> - (chan->flags & IEEE80211_CHAN_NO_IBSS ||
> - chan->flags & IEEE80211_CHAN_DISABLED))
> - 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_NO_IBSS ||
> + chan->flags & IEEE80211_CHAN_DISABLED)
> + return -EINVAL;
> + }
>
> if (wdev->wext.ibss.channel == chan)
> return 0;
> @@ -292,8 +304,7 @@ int cfg80211_ibss_wext_siwfreq(struct ne
> wdev_lock(wdev);
> err = 0;
> if (wdev->ssid_len)
> - err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
> - dev, true);
> + err = __cfg80211_leave_ibss(rdev, dev, true);
> wdev_unlock(wdev);
>
> if (err)
> @@ -307,9 +318,11 @@ int cfg80211_ibss_wext_siwfreq(struct ne
> wdev->wext.ibss.channel_fixed = false;
> }
>
> + mutex_lock(&rdev->devlist_mtx);
> wdev_lock(wdev);
> - err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
> + err = cfg80211_ibss_wext_join(rdev, wdev);
> wdev_unlock(wdev);
> + mutex_unlock(&rdev->devlist_mtx);
>
> return err;
> }
> @@ -347,6 +360,7 @@ int cfg80211_ibss_wext_siwessid(struct n
> 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;
>
> @@ -354,14 +368,13 @@ int cfg80211_ibss_wext_siwessid(struct n
> if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
> return -EINVAL;
>
> - if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
> + if (!rdev->ops->join_ibss)
> return -EOPNOTSUPP;
>
> wdev_lock(wdev);
> err = 0;
> if (wdev->ssid_len)
> - err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
> - dev, true);
> + err = __cfg80211_leave_ibss(rdev, dev, true);
> wdev_unlock(wdev);
>
> if (err)
> @@ -375,9 +388,11 @@ int cfg80211_ibss_wext_siwessid(struct n
> memcpy(wdev->wext.ibss.ssid, ssid, len);
> wdev->wext.ibss.ssid_len = len;
>
> + mutex_lock(&rdev->devlist_mtx);
> wdev_lock(wdev);
> - err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
> + err = cfg80211_ibss_wext_join(rdev, wdev);
> wdev_unlock(wdev);
> + mutex_unlock(&rdev->devlist_mtx);
>
> return err;
> }
> @@ -414,6 +429,7 @@ int cfg80211_ibss_wext_siwap(struct net_
> 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;
>
> @@ -421,7 +437,7 @@ int cfg80211_ibss_wext_siwap(struct net_
> if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
> return -EINVAL;
>
> - if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
> + if (!rdev->ops->join_ibss)
> return -EOPNOTSUPP;
>
> if (ap_addr->sa_family != ARPHRD_ETHER)
> @@ -443,8 +459,7 @@ int cfg80211_ibss_wext_siwap(struct net_
> wdev_lock(wdev);
> err = 0;
> if (wdev->ssid_len)
> - err = __cfg80211_leave_ibss(wiphy_to_dev(wdev->wiphy),
> - dev, true);
> + err = __cfg80211_leave_ibss(rdev, dev, true);
> wdev_unlock(wdev);
>
> if (err)
> @@ -456,9 +471,11 @@ int cfg80211_ibss_wext_siwap(struct net_
> } else
> wdev->wext.ibss.bssid = NULL;
>
> + mutex_lock(&rdev->devlist_mtx);
> wdev_lock(wdev);
> - err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
> + err = cfg80211_ibss_wext_join(rdev, wdev);
> wdev_unlock(wdev);
> + mutex_unlock(&rdev->devlist_mtx);
>
> return err;
> }
> --- wireless-testing.orig/net/wireless/wext-sme.c 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/wext-sme.c 2009-08-07 17:20:31.000000000 +0200
> @@ -52,25 +52,31 @@ int cfg80211_mgd_wext_connect(struct cfg
>
> int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
> struct iw_request_info *info,
> - struct iw_freq *freq, char *extra)
> + 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;
> - int err;
> + struct ieee80211_channel *chan = NULL;
> + int err, freq;
>
> /* call only for station! */
> if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
> return -EINVAL;
>
> - chan = cfg80211_wext_freq(wdev->wiphy, freq);
> - if (chan && IS_ERR(chan))
> - return PTR_ERR(chan);
> -
> - if (chan && (chan->flags & IEEE80211_CHAN_DISABLED))
> - 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) {
> @@ -84,9 +90,8 @@ int cfg80211_mgd_wext_siwfreq(struct net
> /* if SSID set, we'll try right again, avoid event */
> if (wdev->wext.connect.ssid_len)
> event = false;
> - err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
> - dev, WLAN_REASON_DEAUTH_LEAVING,
> - event);
> + err = __cfg80211_disconnect(rdev, dev,
> + WLAN_REASON_DEAUTH_LEAVING, event);
> if (err)
> goto out;
> }
> @@ -95,17 +100,15 @@ int cfg80211_mgd_wext_siwfreq(struct net
> wdev->wext.connect.channel = chan;
>
> /* SSID is not set, we just want to switch channel */
> - if (wdev->wext.connect.ssid_len && chan) {
> - err = -EOPNOTSUPP;
> - if (rdev->ops->set_channel)
> - err = rdev->ops->set_channel(wdev->wiphy, chan,
> - NL80211_CHAN_NO_HT);
> + if (chan && !wdev->wext.connect.ssid_len) {
> + err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
> goto out;
> }
>
> - err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
> + err = cfg80211_mgd_wext_connect(rdev, wdev);
> out:
> wdev_unlock(wdev);
> + mutex_unlock(&rdev->devlist_mtx);
> cfg80211_unlock_rdev(rdev);
> return err;
> }
> @@ -143,6 +146,7 @@ int cfg80211_mgd_wext_siwessid(struct ne
> 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;
>
> @@ -157,7 +161,8 @@ int cfg80211_mgd_wext_siwessid(struct ne
> if (len > 0 && ssid[len - 1] == '\0')
> len--;
>
> - cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
> + cfg80211_lock_rdev(rdev);
> + mutex_lock(&rdev->devlist_mtx);
> wdev_lock(wdev);
>
> err = 0;
> @@ -173,9 +178,8 @@ int cfg80211_mgd_wext_siwessid(struct ne
> /* if SSID set now, we'll try to connect, avoid event */
> if (len)
> event = false;
> - err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
> - dev, WLAN_REASON_DEAUTH_LEAVING,
> - event);
> + err = __cfg80211_disconnect(rdev, dev,
> + WLAN_REASON_DEAUTH_LEAVING, event);
> if (err)
> goto out;
> }
> @@ -186,10 +190,11 @@ int cfg80211_mgd_wext_siwessid(struct ne
>
> wdev->wext.connect.crypto.control_port = false;
>
> - err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
> + err = cfg80211_mgd_wext_connect(rdev, wdev);
> out:
> wdev_unlock(wdev);
> - cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));
> + mutex_unlock(&rdev->devlist_mtx);
> + cfg80211_unlock_rdev(rdev);
> return err;
> }
>
> @@ -230,6 +235,7 @@ int cfg80211_mgd_wext_siwap(struct net_d
> 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;
>
> @@ -244,7 +250,8 @@ int cfg80211_mgd_wext_siwap(struct net_d
> if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
> bssid = NULL;
>
> - cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
> + cfg80211_lock_rdev(rdev);
> + mutex_lock(&rdev->devlist_mtx);
> wdev_lock(wdev);
>
> if (wdev->sme_state != CFG80211_SME_IDLE) {
> @@ -258,9 +265,8 @@ int cfg80211_mgd_wext_siwap(struct net_d
> compare_ether_addr(bssid, wdev->wext.connect.bssid) == 0)
> goto out;
>
> - err = __cfg80211_disconnect(wiphy_to_dev(wdev->wiphy),
> - dev, WLAN_REASON_DEAUTH_LEAVING,
> - false);
> + err = __cfg80211_disconnect(rdev, dev,
> + WLAN_REASON_DEAUTH_LEAVING, false);
> if (err)
> goto out;
> }
> @@ -271,10 +277,11 @@ int cfg80211_mgd_wext_siwap(struct net_d
> } else
> wdev->wext.connect.bssid = NULL;
>
> - err = cfg80211_mgd_wext_connect(wiphy_to_dev(wdev->wiphy), wdev);
> + err = cfg80211_mgd_wext_connect(rdev, wdev);
> out:
> wdev_unlock(wdev);
> - cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));
> + mutex_unlock(&rdev->devlist_mtx);
> + cfg80211_unlock_rdev(rdev);
> return err;
> }
>
> --- wireless-testing.orig/net/wireless/sme.c 2009-08-07 14:50:09.000000000 +0200
> +++ wireless-testing/net/wireless/sme.c 2009-08-07 17:20:31.000000000 +0200
> @@ -256,9 +256,11 @@ void cfg80211_sme_scan_done(struct net_d
> {
> struct wireless_dev *wdev = dev->ieee80211_ptr;
>
> + mutex_lock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
> wdev_lock(wdev);
> __cfg80211_sme_scan_done(dev);
> wdev_unlock(wdev);
> + mutex_unlock(&wiphy_to_dev(wdev->wiphy)->devlist_mtx);
> }
>
> void cfg80211_sme_rx_auth(struct net_device *dev,
> @@ -644,6 +646,7 @@ int __cfg80211_connect(struct cfg80211_r
> struct cfg80211_cached_keys *connkeys)
> {
> struct wireless_dev *wdev = dev->ieee80211_ptr;
> + struct ieee80211_channel *chan;
> int err;
>
> ASSERT_WDEV_LOCK(wdev);
> @@ -651,6 +654,10 @@ int __cfg80211_connect(struct cfg80211_r
> if (wdev->sme_state != CFG80211_SME_IDLE)
> return -EALREADY;
>
> + chan = rdev_fixed_channel(rdev, wdev);
> + if (chan && chan != connect->channel)
> + return -EBUSY;
> +
> if (WARN_ON(wdev->connect_keys)) {
> kfree(wdev->connect_keys);
> wdev->connect_keys = NULL;
> @@ -771,9 +778,11 @@ int cfg80211_connect(struct cfg80211_reg
> {
> int err;
>
> + mutex_lock(&rdev->devlist_mtx);
> wdev_lock(dev->ieee80211_ptr);
> err = __cfg80211_connect(rdev, dev, connect, connkeys);
> wdev_unlock(dev->ieee80211_ptr);
> + mutex_unlock(&rdev->devlist_mtx);
>
> return err;
> }
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html


2009-08-08 08:49:28

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH v4] cfg80211: validate channel settings across interfaces

reinette chatre <[email protected]> writes:

> Hi Johannes,

Hi,

> This patch is now in wireless-testing and it is causing a problem for
> me. This was determined using bisect.
>
> I am able to bring the interface up and scan, but when I try to
> associate I get a hang.
>
> For example, when I run:
> $ iwconfig wlan0 channel <ch> essid <essid>
>
> then the command prompt never returns and system becomes progressively
> unresponsive. The logs do not contain any details of the problem.

I see the same problem with my iwl3945. I do 'sudo ifup wlan0' (which
starts wpa_supplicant), command prompt is printed once and then laptop
just hangs.

Reverting this commit fixes the issue:

commit e66cda2a15bede6fc3fa74482337a00ba768983a
Author: Johannes Berg <[email protected]>
Date: Fri Aug 7 17:22:35 2009 +0200

cfg80211: validate channel settings across interfaces


--
Kalle Valo

2009-08-08 08:43:11

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v4] cfg80211: validate channel settings across interfaces

Hi,

> I am able to bring the interface up and scan, but when I try to
> associate I get a hang.
>
> For example, when I run:
> $ iwconfig wlan0 channel <ch> essid <essid>
>
> then the command prompt never returns and system becomes progressively
> unresponsive. The logs do not contain any details of the problem.

Hmm, yes, that's a pretty obvious deadlock, I obviously didn't test
managed-mode 'iwconfig wlan0 channel' setting. I'll send a fix, I'm
sorry.

johannes


Attachments:
signature.asc (801.00 B)
This is a digitally signed message part

2009-08-07 12:50:38

by Johannes Berg

[permalink] [raw]
Subject: [PATCH v2] 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 <[email protected]>
---
Oops, sorry, now based on the right tree.

net/wireless/Makefile | 3 +
net/wireless/chan.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
net/wireless/core.h | 6 +++
net/wireless/ibss.c | 37 +++++++++++++-----
net/wireless/nl80211.c | 49 ++++---------------------
net/wireless/sme.c | 5 ++
net/wireless/wext-compat.c | 55 +++++++++-------------------
net/wireless/wext-compat.h | 3 -
net/wireless/wext-sme.c | 30 ++++++++-------
9 files changed, 171 insertions(+), 105 deletions(-)

--- wireless-testing.orig/net/wireless/Makefile 2009-08-07 14:47:50.000000000 +0200
+++ wireless-testing/net/wireless/Makefile 2009-08-07 14:47:53.000000000 +0200
@@ -5,7 +5,8 @@ obj-$(CONFIG_LIB80211_CRYPT_WEP) += lib8
obj-$(CONFIG_LIB80211_CRYPT_CCMP) += lib80211_crypt_ccmp.o
obj-$(CONFIG_LIB80211_CRYPT_TKIP) += lib80211_crypt_tkip.o

-cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o mlme.o ibss.o sme.o
+cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o
+cfg80211-y += mlme.o ibss.o sme.o chan.o
cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o
cfg80211-$(CONFIG_WIRELESS_EXT) += wext-compat.o wext-sme.o

--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ wireless-testing/net/wireless/chan.c 2009-08-07 14:47:53.000000000 +0200
@@ -0,0 +1,88 @@
+/*
+ * This file contains helper code to handle channel
+ * settings and keeping track of what is possible at
+ * any point in time.
+ *
+ * Copyright 2009 Johannes Berg <[email protected]>
+ */
+
+#include <net/cfg80211.h>
+#include "core.h"
+
+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev)
+{
+ struct wireless_dev *wdev;
+ struct ieee80211_channel *result = NULL;
+
+ ASSERT_RDEV_LOCK(rdev);
+
+ list_for_each_entry(wdev, &rdev->netdev_list, list) {
+ if (wdev == for_wdev)
+ continue;
+
+ /*
+ * Lock manually to tell lockdep about allowed
+ * nesting here if for_wdev->mtx is held already.
+ * This is ok as it's all under rdev lock and
+ * as such can only be done once at any given
+ * time.
+ */
+ mutex_lock_nested(&wdev->mtx, 1);
+ if (wdev->current_bss)
+ result = wdev->current_bss->pub.channel;
+ wdev_unlock(wdev);
+
+ if (result)
+ break;
+ }
+
+ return result;
+}
+
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type)
+{
+ struct ieee80211_channel *chan;
+ struct ieee80211_sta_ht_cap *ht_cap;
+ int result;
+
+ if (rdev_fixed_channel(rdev, NULL))
+ return -EINVAL;
+
+ if (!rdev->ops->set_channel)
+ return -EOPNOTSUPP;
+
+ chan = ieee80211_get_channel(&rdev->wiphy, freq);
+
+ /* Primary channel not allowed */
+ if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+
+ if (channel_type == NL80211_CHAN_HT40MINUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
+ return -EINVAL;
+ else if (channel_type == NL80211_CHAN_HT40PLUS &&
+ chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
+ return -EINVAL;
+
+ ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
+
+ if (channel_type != NL80211_CHAN_NO_HT) {
+ if (!ht_cap->ht_supported)
+ return -EINVAL;
+
+ if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
+ ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
+ return -EINVAL;
+ }
+
+ result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
+ if (result)
+ return result;
+
+ rdev->channel = chan;
+
+ return 0;
+}
--- wireless-testing.orig/net/wireless/core.h 2009-08-07 14:47:52.000000000 +0200
+++ wireless-testing/net/wireless/core.h 2009-08-07 14:50:05.000000000 +0200
@@ -366,4 +366,10 @@ void cfg80211_sme_disassoc(struct net_de
void __cfg80211_scan_done(struct work_struct *wk);
void cfg80211_upload_connect_keys(struct wireless_dev *wdev);

+struct ieee80211_channel *
+rdev_fixed_channel(struct cfg80211_registered_device *rdev,
+ struct wireless_dev *for_wdev);
+int rdev_set_freq(struct cfg80211_registered_device *rdev,
+ int freq, enum nl80211_channel_type channel_type);
+
#endif /* __NET_WIRELESS_CORE_H */
--- wireless-testing.orig/net/wireless/nl80211.c 2009-08-07 14:47:50.000000000 +0200
+++ wireless-testing/net/wireless/nl80211.c 2009-08-07 14:47:53.000000000 +0200
@@ -701,15 +701,8 @@ static int nl80211_set_wiphy(struct sk_b

if (info->attrs[NL80211_ATTR_WIPHY_FREQ]) {
enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
- struct ieee80211_channel *chan;
- struct ieee80211_sta_ht_cap *ht_cap;
u32 freq;

- if (!rdev->ops->set_channel) {
- result = -EOPNOTSUPP;
- goto bad_res;
- }
-
result = -EINVAL;

if (info->attrs[NL80211_ATTR_WIPHY_CHANNEL_TYPE]) {
@@ -723,42 +716,10 @@ static int nl80211_set_wiphy(struct sk_b
}

freq = nla_get_u32(info->attrs[NL80211_ATTR_WIPHY_FREQ]);
- chan = ieee80211_get_channel(&rdev->wiphy, freq);
-
- /* Primary channel not allowed */
- if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
- goto bad_res;
-
- if (channel_type == NL80211_CHAN_HT40MINUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40MINUS))
- goto bad_res;
- else if (channel_type == NL80211_CHAN_HT40PLUS &&
- (chan->flags & IEEE80211_CHAN_NO_HT40PLUS))
- goto bad_res;
-
- /*
- * At this point we know if that if HT40 was requested
- * we are allowed to use it and the extension channel
- * exists.
- */

- ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
-
- /* no HT capabilities or intolerant */
- if (channel_type != NL80211_CHAN_NO_HT) {
- if (!ht_cap->ht_supported)
- goto bad_res;
- if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
- (ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT))
- goto bad_res;
- }
-
- result = rdev->ops->set_channel(&rdev->wiphy, chan,
- channel_type);
+ result = rdev_set_freq(rdev, freq, channel_type);
if (result)
goto bad_res;
-
- rdev->channel = chan;
}

changed = 0;
@@ -3453,7 +3414,7 @@ static int nl80211_associate(struct sk_b
struct cfg80211_registered_device *rdev;
struct net_device *dev;
struct cfg80211_crypto_settings crypto;
- struct ieee80211_channel *chan;
+ struct ieee80211_channel *chan, *fixedchan;
const u8 *bssid, *ssid, *ie = NULL, *prev_bssid = NULL;
int err, ssid_len, ie_len = 0;
bool use_mfp = false;
@@ -3496,6 +3457,12 @@ static int nl80211_associate(struct sk_b
goto out;
}

+ fixedchan = rdev_fixed_channel(rdev, NULL);
+ if (fixedchan && chan != fixedchan) {
+ err = -EINVAL;
+ goto out;
+ }
+
ssid = nla_data(info->attrs[NL80211_ATTR_SSID]);
ssid_len = nla_len(info->attrs[NL80211_ATTR_SSID]);

--- wireless-testing.orig/net/wireless/wext-compat.c 2009-08-07 14:47:50.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.c 2009-08-07 14:47:53.000000000 +0200
@@ -267,39 +267,26 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwrange
* @wiphy: the wiphy
* @freq: the wext freq encoding
*
- * Returns a channel, %NULL for auto, or an ERR_PTR for errors!
+ * Returns a frequency, or a negative error code, or 0 for auto.
*/
-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq)
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq)
{
- struct ieee80211_channel *chan;
- int f;
-
/*
- * Parse frequency - return NULL for auto and
+ * Parse frequency - return 0 for auto and
* -EINVAL for impossible things.
*/
if (freq->e == 0) {
if (freq->m < 0)
- return NULL;
- f = ieee80211_channel_to_frequency(freq->m);
+ return 0;
+ return ieee80211_channel_to_frequency(freq->m);
} else {
int i, div = 1000000;
for (i = 0; i < freq->e; i++)
div /= 10;
if (div <= 0)
- return ERR_PTR(-EINVAL);
- f = freq->m / div;
+ return -EINVAL;
+ return freq->m / div;
}
-
- /*
- * Look up channel struct and return -EINVAL when
- * it cannot be found.
- */
- chan = ieee80211_get_channel(wiphy, f);
- if (!chan)
- return ERR_PTR(-EINVAL);
- return chan;
}

int cfg80211_wext_siwrts(struct net_device *dev,
@@ -761,33 +748,29 @@ EXPORT_SYMBOL_GPL(cfg80211_wext_giwencod

int cfg80211_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ int freq, err;

switch (wdev->iftype) {
case NL80211_IFTYPE_STATION:
- return cfg80211_mgd_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_mgd_wext_siwfreq(dev, info, wextfreq, extra);
case NL80211_IFTYPE_ADHOC:
- return cfg80211_ibss_wext_siwfreq(dev, info, freq, extra);
+ return cfg80211_ibss_wext_siwfreq(dev, info, wextfreq, extra);
default:
- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (!chan)
+ freq = cfg80211_wext_freq(wdev->wiphy, wextfreq);
+ if (freq < 0)
+ return freq;
+ if (freq == 0)
return -EINVAL;
- if (IS_ERR(chan))
- return PTR_ERR(chan);
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
- if (err)
- return err;
- rdev->channel = chan;
- return 0;
+ cfg80211_lock_rdev(rdev);
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
+ cfg80211_unlock_rdev(rdev);
+ return err;
}
}
-EXPORT_SYMBOL_GPL(cfg80211_wext_siwfreq);

int cfg80211_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
--- wireless-testing.orig/net/wireless/wext-compat.h 2009-08-07 14:47:50.000000000 +0200
+++ wireless-testing/net/wireless/wext-compat.h 2009-08-07 14:47:53.000000000 +0200
@@ -42,8 +42,7 @@ int cfg80211_mgd_wext_giwessid(struct ne
struct iw_request_info *info,
struct iw_point *data, char *ssid);

-struct ieee80211_channel *cfg80211_wext_freq(struct wiphy *wiphy,
- struct iw_freq *freq);
+int cfg80211_wext_freq(struct wiphy *wiphy, struct iw_freq *freq);


extern const struct iw_handler_def cfg80211_wext_handler;
--- wireless-testing.orig/net/wireless/ibss.c 2009-08-07 14:47:50.000000000 +0200
+++ wireless-testing/net/wireless/ibss.c 2009-08-07 14:47:53.000000000 +0200
@@ -78,10 +78,15 @@ int __cfg80211_join_ibss(struct cfg80211
struct cfg80211_cached_keys *connkeys)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != params->channel)
+ return -EINVAL;
+
if (wdev->ssid_len)
return -EALREADY;

@@ -264,11 +269,11 @@ int cfg80211_ibss_wext_join(struct cfg80

int cfg80211_ibss_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ struct iw_freq *wextfreq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
- struct ieee80211_channel *chan;
- int err;
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for ibss! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_ADHOC))
@@ -277,14 +282,18 @@ int cfg80211_ibss_wext_siwfreq(struct ne
if (!wiphy_to_dev(wdev->wiphy)->ops->join_ibss)
return -EOPNOTSUPP;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan &&
- (chan->flags & IEEE80211_CHAN_NO_IBSS ||
- chan->flags & IEEE80211_CHAN_DISABLED))
- 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_NO_IBSS ||
+ chan->flags & IEEE80211_CHAN_DISABLED)
+ return -EINVAL;
+ }

if (wdev->wext.ibss.channel == chan)
return 0;
@@ -307,9 +316,11 @@ int cfg80211_ibss_wext_siwfreq(struct ne
wdev->wext.ibss.channel_fixed = false;
}

+ cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
wdev_lock(wdev);
err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
wdev_unlock(wdev);
+ cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));

return err;
}
@@ -375,9 +386,11 @@ int cfg80211_ibss_wext_siwessid(struct n
memcpy(wdev->wext.ibss.ssid, ssid, len);
wdev->wext.ibss.ssid_len = len;

+ cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
wdev_lock(wdev);
err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
wdev_unlock(wdev);
+ cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));

return err;
}
@@ -456,9 +469,11 @@ int cfg80211_ibss_wext_siwap(struct net_
} else
wdev->wext.ibss.bssid = NULL;

+ cfg80211_lock_rdev(wiphy_to_dev(wdev->wiphy));
wdev_lock(wdev);
err = cfg80211_ibss_wext_join(wiphy_to_dev(wdev->wiphy), wdev);
wdev_unlock(wdev);
+ cfg80211_unlock_rdev(wiphy_to_dev(wdev->wiphy));

return err;
}
--- wireless-testing.orig/net/wireless/wext-sme.c 2009-08-07 14:47:51.000000000 +0200
+++ wireless-testing/net/wireless/wext-sme.c 2009-08-07 14:50:05.000000000 +0200
@@ -52,23 +52,28 @@ int cfg80211_mgd_wext_connect(struct cfg

int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
- struct iw_freq *freq, char *extra)
+ 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;
- int err;
+ struct ieee80211_channel *chan = NULL;
+ int err, freq;

/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;

- chan = cfg80211_wext_freq(wdev->wiphy, freq);
- if (chan && IS_ERR(chan))
- return PTR_ERR(chan);
-
- if (chan && (chan->flags & IEEE80211_CHAN_DISABLED))
- 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);
wdev_lock(wdev);
@@ -95,11 +100,8 @@ int cfg80211_mgd_wext_siwfreq(struct net
wdev->wext.connect.channel = chan;

/* SSID is not set, we just want to switch channel */
- if (wdev->wext.connect.ssid_len && chan) {
- err = -EOPNOTSUPP;
- if (rdev->ops->set_channel)
- err = rdev->ops->set_channel(wdev->wiphy, chan,
- NL80211_CHAN_NO_HT);
+ if (chan && !wdev->wext.connect.ssid_len) {
+ err = rdev_set_freq(rdev, freq, NL80211_CHAN_NO_HT);
goto out;
}

--- wireless-testing.orig/net/wireless/sme.c 2009-08-07 14:47:51.000000000 +0200
+++ wireless-testing/net/wireless/sme.c 2009-08-07 14:50:05.000000000 +0200
@@ -644,6 +644,7 @@ int __cfg80211_connect(struct cfg80211_r
struct cfg80211_cached_keys *connkeys)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
+ struct ieee80211_channel *chan;
int err;

ASSERT_WDEV_LOCK(wdev);
@@ -651,6 +652,10 @@ int __cfg80211_connect(struct cfg80211_r
if (wdev->sme_state != CFG80211_SME_IDLE)
return -EALREADY;

+ chan = rdev_fixed_channel(rdev, wdev);
+ if (chan && chan != connect->channel)
+ return -EINVAL;
+
if (WARN_ON(wdev->connect_keys)) {
kfree(wdev->connect_keys);
wdev->connect_keys = NULL;



2009-08-08 20:10:54

by Kalle Valo

[permalink] [raw]
Subject: Re: [PATCH v4] cfg80211: validate channel settings across interfaces

Larry Finger <[email protected]> writes:

>> For example, when I run:
>> $ iwconfig wlan0 channel <ch> essid <essid>
>>
>> then the command prompt never returns and system becomes progressively
>> unresponsive. The logs do not contain any details of the problem.
>
> I have the same problem here as well.

This patch fixes the issue:

commit 21e433f9ea04c319cc12b4094f292a8f1ad709e9
Author: Johannes Berg <[email protected]>
Date: Sat Aug 8 11:03:58 2009 +0200

cfg80211: fix locking for SIWFREQ

Johannes sent it to the list this today and it's not in wireless-testing
yet.

--
Kalle Valo