mac80211: simplify zero address checks

The libertas_tf special code for zero addresses
is a bit too complex, it compares against a stack
value instead of using is_zero_ether_addr() and
tries to update all interfaces even if just the
one that's being brought up needs to be changed.
Additionally, the repeated check for a valid MAC
address need only be done if we actually changed
it on the fly.

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

1 files changed, 13 insertions, 25 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index cc1c68d7dda6..ea50732ec526 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -103,10 +103,9 @@ static int ieee80211_open(struct net_device *dev)
         u32 changed = 0;
         int res;
         u32 hw_reconf_flags = 0;
-        u8 null_addr[ETH_ALEN] = {0};
 
         /* fail early if user set an invalid address */
-        if (compare_ether_addr(dev->dev_addr, null_addr) &&
+        if (!is_zero_ether_addr(dev->dev_addr) &&
             !is_valid_ether_addr(dev->dev_addr))
                 return -EADDRNOTAVAIL;
 
@@ -195,33 +194,22 @@ static int ieee80211_open(struct net_device *dev)
         }
 
         /*
-         * Check all interfaces and copy the hopefully now-present
-         * MAC address to those that have the special null one.
+         * Copy the hopefully now-present MAC address to
+         * this interface, if it has the special null one.
          */
-        list_for_each_entry(nsdata, &local->interfaces, list) {
-                struct net_device *ndev = nsdata->dev;
-
-                /*
-                 * No need to check running since we do not allow
-                 * it to start up with this invalid address.
-                 */
-                if (compare_ether_addr(null_addr, ndev->dev_addr) == 0) {
-                        memcpy(ndev->dev_addr,
-                               local->hw.wiphy->perm_addr,
-                               ETH_ALEN);
-                        memcpy(ndev->perm_addr, ndev->dev_addr, ETH_ALEN);
+        if (is_zero_ether_addr(dev->dev_addr)) {
+                memcpy(dev->dev_addr,
+                       local->hw.wiphy->perm_addr,
+                       ETH_ALEN);
+                memcpy(dev->perm_addr, dev->dev_addr, ETH_ALEN);
+
+                if (!is_valid_ether_addr(dev->dev_addr)) {
+                        if (!local->open_count)
+                                drv_stop(local);
+                        return -EADDRNOTAVAIL;
                 }
         }
 
-        /*
-         * Validate the MAC address for this device.
-         */
-        if (!is_valid_ether_addr(dev->dev_addr)) {
-                if (!local->open_count)
-                        drv_stop(local);
-                return -EADDRNOTAVAIL;
-        }
-
         switch (sdata->vif.type) {
         case NL80211_IFTYPE_AP_VLAN:
                 /* no need to tell driver */