| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | From 974dc36a87274d7bae13e7dddd3364fecf5b3e7c Mon Sep 17 00:00:00 2001 |
| 2 | From: Helmut Schaa <helmut.schaa@googlemail.com> |
| 3 | Date: Wed, 8 Jan 2014 13:48:49 +0100 |
| 4 | Subject: [PATCH] netdev-linux: Let interface flag survive internal port setup |
| 5 | |
| 6 | Due to a race condition when bringing up an internal port on Linux |
| 7 | some interface flags (e.g. IFF_MULTICAST) are falsely reset. This |
| 8 | happens because netlink events may be processed after the according |
| 9 | netdev has been brought up (which sets interface flags). |
| 10 | |
| 11 | Fix this by reading the interface flags just before updating them |
| 12 | if they have not been updated by from the kernel yet. |
| 13 | |
| 14 | Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com> |
| 15 | --- |
| 16 | lib/netdev-linux.c | 8 +++++++- |
| 17 | 1 file changed, 7 insertions(+), 1 deletion(-) |
| 18 | |
| 19 | --- a/lib/netdev-linux.c |
| 20 | +++ b/lib/netdev-linux.c |
| 21 | @@ -3571,7 +3571,13 @@ update_flags(struct netdev_linux *netdev |
| 22 | unsigned int old_flags, new_flags; |
| 23 | int error = 0; |
| 24 | |
| 25 | - old_flags = netdev->ifi_flags; |
| 26 | + if (!(netdev->cache_valid & VALID_DRVINFO)) { |
| 27 | + /* Most likely the debvice flags are not in sync yet, fetch them now */ |
| 28 | + get_flags(&netdev->up, &old_flags); |
| 29 | + } else { |
| 30 | + old_flags = netdev->ifi_flags; |
| 31 | + } |
| 32 | + |
| 33 | *old_flagsp = iff_to_nd_flags(old_flags); |
| 34 | new_flags = (old_flags & ~nd_to_iff_flags(off)) | nd_to_iff_flags(on); |
| 35 | if (new_flags != old_flags) { |