[86/90] net: Fix userspace RTM_NEWLINK notifications.
From: Greg KH <gregkh@suse.de>
Date: 2009-12-17 01:25:55
Also in:
lkml
2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ commit d90a909e1f3e006a1d57fe11fd417173b6494701 upstream. I received some bug reports about userspace programs having problems because after RTM_NEWLINK was received they could not immeidate access files under /proc/sys/net/ because they had not been registered yet. The problem was trivailly fixed by moving the userspace notification from rtnetlink_event to the end of register_netdevice. Signed-off-by: Eric W. Biederman <redacted> Cc: David Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- net/core/dev.c | 11 +++++++++++ net/core/rtnetlink.c | 4 +--- 2 files changed, 12 insertions(+), 3 deletions(-)
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -4808,6 +4808,11 @@ int register_netdevice(struct net_device rollback_registered(dev); dev->reg_state = NETREG_UNREGISTERED; } + /* + * Prevent userspace races by waiting until the network + * device is fully setup before sending notifications. + */ + rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); out: return ret;
@@ -5343,6 +5348,12 @@ int dev_change_net_namespace(struct net_ /* Notify protocols, that a new device appeared. */ call_netdevice_notifiers(NETDEV_REGISTER, dev); + /* + * Prevent userspace races by waiting until the network + * device is fully setup before sending notifications. + */ + rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); + synchronize_net(); err = 0; out: --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c
@@ -1347,13 +1347,11 @@ static int rtnetlink_event(struct notifi case NETDEV_UNREGISTER: rtmsg_ifinfo(RTM_DELLINK, dev, ~0U); break; - case NETDEV_REGISTER: - rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U); - break; case NETDEV_UP: case NETDEV_DOWN: rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING); break; + case NETDEV_REGISTER: case NETDEV_CHANGE: case NETDEV_GOING_DOWN: break;