diff mbox

[net-next,v2,2/3] net: dev: revert the mac address when notifier failed

Message ID 1401969663-4464-3-git-send-email-dingtianhong@huawei.com
State New
Headers show

Commit Message

Ding Tianhong June 5, 2014, 12:01 p.m. UTC 
When set a new mac address to a netdev, the dev should propagate
to the upperdev or lowerdev and make sure the new mac address could
work well with other devs, otherwise the new mac address shouldn't
be set and revert the old mac address.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
---
 net/core/dev.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 5367bfb..b0fb3dd 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5562,6 +5562,7 @@  EXPORT_SYMBOL(dev_set_group);
 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 {
 	const struct net_device_ops *ops = dev->netdev_ops;
+	struct sockaddr old_sa;
 	int err;
 
 	if (!ops->ndo_set_mac_address)
@@ -5570,13 +5571,27 @@  int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
 		return -EINVAL;
 	if (!netif_device_present(dev))
 		return -ENODEV;
+
+	old_sa.sa_family = dev->type;
+	ether_addr_copy(old_sa.sa_data, dev->dev_addr);
+
 	err = ops->ndo_set_mac_address(dev, sa);
 	if (err)
 		return err;
-	dev->addr_assign_type = NET_ADDR_SET;
-	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
-	add_device_randomness(dev->dev_addr, dev->addr_len);
-	return 0;
+
+	err = call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
+	err = notifier_to_errno(err);
+	if (err) {
+		/* setting mac address back and notify everyone again,
+		 * so that they have a chance to revert changes.
+		 */
+		ops->ndo_set_mac_address(dev, &old_sa);
+		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
+	} else {
+		dev->addr_assign_type = NET_ADDR_SET;
+		add_device_randomness(dev->dev_addr, dev->addr_len);
+	}
+	return err;
 }
 EXPORT_SYMBOL(dev_set_mac_address);