[PATCH net-next v2 2/3] net: dev: revert the mac address when notifier failed
From: Ding Tianhong <hidden>
Date: 2014-06-05 12:01:28
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> --- net/core/dev.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-)
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);
--
1.8.0