commit 56d1893d94bc06d0b1aa3a53f924ed02f9e207bf
author Johannes Berg <johannes.berg@intel.com> Mon May 09 18:41:15 2011 +0200
committer John W. Linville <linville@tuxdriver.com> Thu May 12 14:10:47 2011 -0400
tree 90862ae6788cf267631bd9ddebf4bc450d0d2b26
parent 15cb309614f35df344b9f06a9ea9f077d1e449db

cfg80211: restrict AP beacon intervals

Multiple virtual AP interfaces can currently try
to use different beacon intervals, but that just
leads to problems since it won't actually be done
that way by drivers. Return an error in this case
to make sure it won't be done wrong.

Also, ignore attempts to change the DTIM period
or beacon interval during the lifetime of the BSS.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/nl80211.c

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b5b050b..9ef8e28 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1876,8 +1876,9 @@
 		    struct beacon_parameters *info);
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct net_device *dev = info->user_ptr[1];
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct beacon_parameters params;
-	int haveinfo = 0;
+	int haveinfo = 0, err;
 
 	if (!is_valid_ie_attr(info->attrs[NL80211_ATTR_BEACON_TAIL]))
 		return -EINVAL;
@@ -1886,6 +1887,8 @@
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
 		return -EOPNOTSUPP;
 
+	memset(&params, 0, sizeof(params));
+
 	switch (info->genlhdr->cmd) {
 	case NL80211_CMD_NEW_BEACON:
 		/* these are required for NEW_BEACON */
@@ -1894,6 +1897,15 @@
 		    !info->attrs[NL80211_ATTR_BEACON_HEAD])
 			return -EINVAL;
 
+		params.interval =
+			nla_get_u32(info->attrs[NL80211_ATTR_BEACON_INTERVAL]);
+		params.dtim_period =
+			nla_get_u32(info->attrs[NL80211_ATTR_DTIM_PERIOD]);
+
+		err = cfg80211_validate_beacon_int(rdev, params.interval);
+		if (err)
+			return err;
+
 		call = rdev->ops->add_beacon;
 		break;
 	case NL80211_CMD_SET_BEACON:
@@ -1907,20 +1919,6 @@
 	if (!call)
 		return -EOPNOTSUPP;
 
-	memset(&params, 0, sizeof(params));
-
-	if (info->attrs[NL80211_ATTR_BEACON_INTERVAL]) {
-		params.interval =
-		    nla_get_u32(info->attrs[NL80211_ATTR_BEACON_INTERVAL]);
-		haveinfo = 1;
-	}
-
-	if (info->attrs[NL80211_ATTR_DTIM_PERIOD]) {
-		params.dtim_period =
-		    nla_get_u32(info->attrs[NL80211_ATTR_DTIM_PERIOD]);
-		haveinfo = 1;
-	}
-
 	if (info->attrs[NL80211_ATTR_BEACON_HEAD]) {
 		params.head = nla_data(info->attrs[NL80211_ATTR_BEACON_HEAD]);
 		params.head_len =
@@ -1938,13 +1936,18 @@
 	if (!haveinfo)
 		return -EINVAL;
 
-	return call(&rdev->wiphy, dev, &params);
+	err = call(&rdev->wiphy, dev, &params);
+	if (!err && params.interval)
+		wdev->beacon_interval = params.interval;
+	return err;
 }
 
 static int nl80211_del_beacon(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct net_device *dev = info->user_ptr[1];
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	int err;
 
 	if (!rdev->ops->del_beacon)
 		return -EOPNOTSUPP;
@@ -1953,7 +1956,10 @@
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
 		return -EOPNOTSUPP;
 
-	return rdev->ops->del_beacon(&rdev->wiphy, dev);
+	err = rdev->ops->del_beacon(&rdev->wiphy, dev);
+	if (!err)
+		wdev->beacon_interval = 0;
+	return err;
 }
 
 static const struct nla_policy sta_flags_policy[NL80211_STA_FLAG_MAX + 1] = {