[PATCH] cfg80211: re-join IBSS when privacy changes

Johannes Berg
2009-11-18T12:04:13Z

When going from/to a WEP protected IBSS, we need to
leave this one and join a new one to take care of
the changed capability.

Cc: Hong Zhang <henryzhang62@yahoo.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
net/wireless/core.h | 2 +
net/wireless/ibss.c | 4 +--
net/wireless/wext-compat.c | 49 ++++++++++++++++++++++++++++++++++++---------
3 files changed, 44 insertions(+), 11 deletions(-)

--- wireless-testing.orig/net/wireless/ibss.c 2009-11-18 11:42:49.000000000 +0100
+++ wireless-testing/net/wireless/ibss.c 2009-11-18 11:47:35.000000000 +0100
@@ -169,8 +169,8 @@ void cfg80211_clear_ibss(struct net_devi
wdev_unlock(wdev);
}

-static int __cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
- struct net_device *dev, bool nowext)
+int __cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
+ struct net_device *dev, bool nowext)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err;
--- wireless-testing.orig/net/wireless/wext-compat.c 2009-11-18 11:42:49.000000000 +0100
+++ wireless-testing/net/wireless/wext-compat.c 2009-11-18 12:52:45.000000000 +0100
@@ -437,6 +437,7 @@ static int __cfg80211_set_encryption(str
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
int err, i;
+ bool rejoin = false;

if (!wdev->wext.keys) {
wdev->wext.keys = kzalloc(sizeof(*wdev->wext.keys),
@@ -466,8 +467,24 @@ static int __cfg80211_set_encryption(str

if (remove) {
err = 0;
- if (wdev->current_bss)
+ if (wdev->current_bss) {
+ /*
+ * If removing the current TX key, we will need to
+ * join a new IBSS without the privacy bit clear.
+ */
+ if (idx == wdev->wext.default_key &&
+ wdev->iftype == NL80211_IFTYPE_ADHOC) {
+ __cfg80211_leave_ibss(rdev, wdev->netdev, true);
+ rejoin = true;
+ }
err = rdev->ops->del_key(&rdev->wiphy, dev, idx, addr);
+ }
+ /*
+ * Applications using wireless extensions expect to be
+ * able to delete keys that don't exist, so allow that.
+ */
+ if (err == -ENOENT)
+ err = 0;
if (!err) {
if (!addr) {
wdev->wext.keys->params[idx].key_len = 0;
@@ -478,12 +495,9 @@ static int __cfg80211_set_encryption(str
else if (idx == wdev->wext.default_mgmt_key)
wdev->wext.default_mgmt_key = -1;
}
- /*
- * Applications using wireless extensions expect to be
- * able to delete keys that don't exist, so allow that.
- */
- if (err == -ENOENT)
- return 0;
+
+ if (!err && rejoin)
+ err = cfg80211_ibss_wext_join(rdev, wdev);

return err;
}
@@ -511,11 +525,25 @@ static int __cfg80211_set_encryption(str
if ((params->cipher == WLAN_CIPHER_SUITE_WEP40 ||
params->cipher == WLAN_CIPHER_SUITE_WEP104) &&
(tx_key || (!addr && wdev->wext.default_key == -1))) {
- if (wdev->current_bss)
+ if (wdev->current_bss) {
+ /*
+ * If we are getting a new TX key from not having
+ * had one before we need to join a new IBSS with
+ * the privacy bit set.
+ */
+ if (wdev->iftype == NL80211_IFTYPE_ADHOC &&
+ wdev->wext.default_key == -1) {
+ __cfg80211_leave_ibss(rdev, wdev->netdev, true);
+ rejoin = true;
+ }
err = rdev->ops->set_default_key(&rdev->wiphy,
dev, idx);
- if (!err)
+ }
+ if (!err) {
wdev->wext.default_key = idx;
+ if (rejoin)
+ err = cfg80211_ibss_wext_join(rdev, wdev);
+ }
return err;
}

@@ -539,10 +567,13 @@ static int cfg80211_set_encryption(struc
{
int err;

+ /* devlist mutex needed for possible IBSS re-join */
+ mutex_lock(&rdev->devlist_mtx);
wdev_lock(dev->ieee80211_ptr);
err = __cfg80211_set_encryption(rdev, dev, addr, remove,
tx_key, idx, params);
wdev_unlock(dev->ieee80211_ptr);
+ mutex_unlock(&rdev->devlist_mtx);

return err;
}
--- wireless-testing.orig/net/wireless/core.h 2009-11-18 11:42:49.000000000 +0100
+++ wireless-testing/net/wireless/core.h 2009-11-18 11:47:35.000000000 +0100
@@ -273,6 +273,8 @@ int cfg80211_join_ibss(struct cfg80211_r
struct cfg80211_ibss_params *params,
struct cfg80211_cached_keys *connkeys);
void cfg80211_clear_ibss(struct net_device *dev, bool nowext);
+int __cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
+ struct net_device *dev, bool nowext);
int cfg80211_leave_ibss(struct cfg80211_registered_device *rdev,
struct net_device *dev, bool nowext);
void __cfg80211_ibss_joined(struct net_device *dev, const u8 *bssid);