On 10/11/21 6:12 AM, Daniel Borkmann wrote:
> The NTF_EXT_LEARNED neigh flag is usually propagated back to user space
> upon dump of the neighbor table. However, when used in combination with
> NTF_USE flag this is not the case despite exempting the entry from the
> garbage collector. This results in inconsistent state since entries are
> typically marked in neigh->flags with NTF_EXT_LEARNED, but here they are
> not. Fix it by propagating the creation flag to ___neigh_create().
>
> Before fix:
>
> # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
> # ./ip/ip n
> 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a REACHABLE
> [...]
>
> After fix:
>
> # ./ip/ip n replace 192.168.178.30 dev enp5s0 use extern_learn
> # ./ip/ip n
> 192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a extern_learn REACHABLE
> [...]
>
> Fixes: 9ce33e46531d ("neighbour: support for NTF_EXT_LEARNED flag")
> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Acked-by: Roopa Prabhu <roopa@xxxxxxxxxx>
> ---
> net/core/neighbour.c | 26 ++++++++++++++------------
> 1 file changed, 14 insertions(+), 12 deletions(-)
>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
