[PATCH] mac80211: validate VLAN interfaces better

This patch changes mac80211 to verify that VLAN interfaces
are valid and not bother drivers about them any more.
VLAN interfaces are now only valid when an AP interface
is up with the same MAC address, and are automatically
turned off when the AP interface is set down.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Jouni Malinen <j@w1.fi>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 47 insertions, 7 deletions

diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index 319ec2a..4e345f8 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -314,22 +314,43 @@ static int ieee80211_open(struct net_device *dev)
 	int res;
 
 	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+
 	read_lock(&local->sub_if_lock);
 	list_for_each_entry(nsdata, &local->sub_if_list, list) {
 		struct net_device *ndev = nsdata->dev;
 
 		if (ndev != dev && ndev != local->mdev && netif_running(ndev) &&
-		    compare_ether_addr(dev->dev_addr, ndev->dev_addr) == 0 &&
-		    !identical_mac_addr_allowed(sdata->type, nsdata->type)) {
-			read_unlock(&local->sub_if_lock);
-			return -ENOTUNIQ;
+		    compare_ether_addr(dev->dev_addr, ndev->dev_addr) == 0) {
+			/*
+			 * check whether it may have the same address
+			 */
+			if (!identical_mac_addr_allowed(sdata->type,
+							nsdata->type)) {
+				read_unlock(&local->sub_if_lock);
+				return -ENOTUNIQ;
+			}
+
+			/*
+			 * can only add VLANs to enabled APs
+			 */
+			if (sdata->type == IEEE80211_IF_TYPE_VLAN &&
+			    nsdata->type == IEEE80211_IF_TYPE_AP &&
+			    netif_running(nsdata->dev))
+				sdata->u.vlan.ap = nsdata;
 		}
 	}
 	read_unlock(&local->sub_if_lock);
 
-	if (sdata->type == IEEE80211_IF_TYPE_WDS &&
-	    is_zero_ether_addr(sdata->u.wds.remote_addr))
-		return -ENOLINK;
+	switch (sdata->type) {
+	case IEEE80211_IF_TYPE_WDS:
+		if (is_zero_ether_addr(sdata->u.wds.remote_addr))
+			return -ENOLINK;
+		break;
+	case IEEE80211_IF_TYPE_VLAN:
+		if (!sdata->u.vlan.ap)
+			return -ENOLINK;
+		break;
+	}
 
 	if (local->open_count == 0) {
 		res = 0;
@@ -340,6 +361,10 @@ static int ieee80211_open(struct net_device *dev)
 	}
 
 	switch (sdata->type) {
+	case IEEE80211_IF_TYPE_VLAN:
+		list_add(&sdata->u.vlan.list, &sdata->u.vlan.ap->u.ap.vlans);
+		/* no need to tell driver */
+		break;
 	case IEEE80211_IF_TYPE_MNTR:
 		/* must be before the call to ieee80211_configure_filter */
 		local->monitors++;
@@ -407,9 +432,24 @@ static int ieee80211_stop(struct net_device *dev)
 
 	dev_mc_unsync(local->mdev, dev);
 
+	/* down all dependent devices, that is VLANs */
+	if (sdata->type == IEEE80211_IF_TYPE_AP) {
+		struct ieee80211_sub_if_data *vlan, *tmp;
+
+		list_for_each_entry_safe(vlan, tmp, &sdata->u.ap.vlans,
+					 u.vlan.list)
+			dev_close(vlan->dev);
+		WARN_ON(!list_empty(&sdata->u.ap.vlans));
+	}
+
 	local->open_count--;
 
 	switch (sdata->type) {
+	case IEEE80211_IF_TYPE_VLAN:
+		list_del(&sdata->u.vlan.list);
+		sdata->u.vlan.ap = NULL;
+		/* no need to tell driver */
+		break;
 	case IEEE80211_IF_TYPE_MNTR:
 		local->monitors--;
 		if (local->monitors == 0) {