net: introduce pre-up netdev notifier
NETDEV_UP is called after the device is set UP, but sometimes
it is useful to be able to veto the device UP. Introduce a
new NETDEV_PRE_UP notifier that can be used for exactly this.
The first use case will be cfg80211 denying interfaces to be
set UP if the device is known to be rfkill'ed.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index b86fa2f..81bc252 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -198,6 +198,7 @@
#define NETDEV_CHANGENAME 0x000A
#define NETDEV_FEAT_CHANGE 0x000B
#define NETDEV_BONDING_FAILOVER 0x000C
+#define NETDEV_PRE_UP 0x000D
#define SYS_DOWN 0x0001 /* Notify of system down */
#define SYS_RESTART SYS_DOWN
diff --git a/net/core/dev.c b/net/core/dev.c
index 34b49a6..1f38401 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1048,7 +1048,7 @@
int dev_open(struct net_device *dev)
{
const struct net_device_ops *ops = dev->netdev_ops;
- int ret = 0;
+ int ret;
ASSERT_RTNL();
@@ -1065,6 +1065,11 @@
if (!netif_device_present(dev))
return -ENODEV;
+ ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
+ ret = notifier_to_errno(ret);
+ if (ret)
+ return ret;
+
/*
* Call device private open method
*/