From 66f96259c596f8f303bd98e5323a447cd60adbb2 Mon Sep 17 00:00:00 2001 From: Helmut Schaa Date: Wed, 8 Jan 2014 13:48:49 +0100 Subject: [PATCH] netdev-linux: Let interface flag survive internal port setup Due to a race condition when bringing up an internal port on Linux some interface flags (e.g. IFF_MULTICAST) are falsely reset. This happens because netlink events may be processed after the according netdev has been brought up (which sets interface flags). Fix this by reading the interface flags just before updating them if they have not been updated by from the kernel yet. Signed-off-by: Helmut Schaa --- lib/netdev-linux.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c index c6f3d2740..136668b1d 100644 --- a/lib/netdev-linux.c +++ b/lib/netdev-linux.c @@ -3461,7 +3461,13 @@ update_flags(struct netdev_linux *netdev, enum netdev_flags off, unsigned int old_flags, new_flags; int error = 0; - old_flags = netdev->ifi_flags; + if (!(netdev->cache_valid & VALID_DRVINFO)) { + /* Most likely the debvice flags are not in sync yet, fetch them now */ + get_flags(&netdev->up, &old_flags); + } else { + old_flags = netdev->ifi_flags; + } + *old_flagsp = iff_to_nd_flags(old_flags); new_flags = (old_flags & ~nd_to_iff_flags(off)) | nd_to_iff_flags(on); if (new_flags != old_flags) {