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authorEric W. Biederman <ebiederm@xmission.com>2009-12-12 17:11:15 -0500
committerDavid S. Miller <davem@davemloft.net>2009-12-13 22:45:22 -0500
commitd90a909e1f3e006a1d57fe11fd417173b6494701 (patch)
tree72893da9ed5083b44dbb8d778d648e114d351a0a /net/core
parent5781b2356cbecb0b73b06ec8c3897cabdfdd0928 (diff)
net: Fix userspace RTM_NEWLINK notifications.
I received some bug reports about userspace programs having problems because after RTM_NEWLINK was received they could not immediate access files under /proc/sys/net/ because they had not been registered yet. The original problem was trivially fixed by moving the userspace notification from rtnetlink_event() to the end of register_netdevice(). When testing that change I discovered I was still getting RTM_NEWLINK events before I could access proc and I was also getting RTM_NEWLINK events after I was seeing RTM_DELLINK. Things practically guaranteed to confuse userspace. After a little more investigation these extra notifications proved to be from the new notifiers NETDEV_POST_INIT and NETDEV_UNREGISTER_BATCH hitting the default case in rtnetlink_event, and triggering unnecessary RTM_NEWLINK messages. rtnetlink_event now explicitly handles NETDEV_UNREGISTER_BATCH and NETDEV_POST_INIT to avoid sending the incorrect userspace notifications. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c11
-rw-r--r--net/core/rtnetlink.c6
2 files changed, 14 insertions, 3 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 6fe7d739e59b..be9924f60ec3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5035,6 +5035,11 @@ int register_netdevice(struct net_device *dev)
5035 rollback_registered(dev); 5035 rollback_registered(dev);
5036 dev->reg_state = NETREG_UNREGISTERED; 5036 dev->reg_state = NETREG_UNREGISTERED;
5037 } 5037 }
5038 /*
5039 * Prevent userspace races by waiting until the network
5040 * device is fully setup before sending notifications.
5041 */
5042 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5038 5043
5039out: 5044out:
5040 return ret; 5045 return ret;
@@ -5597,6 +5602,12 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
5597 /* Notify protocols, that a new device appeared. */ 5602 /* Notify protocols, that a new device appeared. */
5598 call_netdevice_notifiers(NETDEV_REGISTER, dev); 5603 call_netdevice_notifiers(NETDEV_REGISTER, dev);
5599 5604
5605 /*
5606 * Prevent userspace races by waiting until the network
5607 * device is fully setup before sending notifications.
5608 */
5609 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5610
5600 synchronize_net(); 5611 synchronize_net();
5601 err = 0; 5612 err = 0;
5602out: 5613out:
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 33148a568199..794bcb897ff0 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1364,15 +1364,15 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
1364 case NETDEV_UNREGISTER: 1364 case NETDEV_UNREGISTER:
1365 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U); 1365 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
1366 break; 1366 break;
1367 case NETDEV_REGISTER:
1368 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
1369 break;
1370 case NETDEV_UP: 1367 case NETDEV_UP:
1371 case NETDEV_DOWN: 1368 case NETDEV_DOWN:
1372 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING); 1369 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1373 break; 1370 break;
1371 case NETDEV_POST_INIT:
1372 case NETDEV_REGISTER:
1374 case NETDEV_CHANGE: 1373 case NETDEV_CHANGE:
1375 case NETDEV_GOING_DOWN: 1374 case NETDEV_GOING_DOWN:
1375 case NETDEV_UNREGISTER_BATCH:
1376 break; 1376 break;
1377 default: 1377 default:
1378 rtmsg_ifinfo(RTM_NEWLINK, dev, 0); 1378 rtmsg_ifinfo(RTM_NEWLINK, dev, 0);