On Fri, Jan 26, 2018 at 11:40:17AM -0800, Wei Wang wrote:
> From: Wei Wang <wei...@google.com>
>
> In current route cache aging logic, if a route has both RTF_EXPIRE and
> RTF_GATEWAY set, the route will only be removed if the neighbor cache
> has no RTN_ROUTE flag. Otherwise, even if the route has expired, it
You meant NTF_ROUTER instead of RTN_ROUTE?
> won't get deleted.
> Fix this logic to always check if the route has expired first and then
> do the gateway neighbor cache check if previous check decide to not
> remove the exception entry.
>
> Fixes: 1859bac04fb6 ("ipv6: remove from fib tree aged out RTF_CACHE dst")
> Signed-off-by: Wei Wang <wei...@google.com>
> Signed-off-by: Eric Dumazet <eduma...@google.com>
Nice catch!
Acked-by: Martin KaFai Lau <ka...@fb.com>
> ---
> net/ipv6/route.c | 20 ++++++++++++--------
> 1 file changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 0458b761f3c5..a560fb1d0230 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -1586,12 +1586,19 @@ static void rt6_age_examine_exception(struct
> rt6_exception_bucket *bucket,
> * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
> * expired, independently from their aging, as per RFC 8201 section 4
> */
> - if (!(rt->rt6i_flags & RTF_EXPIRES) &&
> - time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
> - RT6_TRACE("aging clone %p\n", rt);
> + if (!(rt->rt6i_flags & RTF_EXPIRES)) {
> + if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
> + RT6_TRACE("aging clone %p\n", rt);
> + rt6_remove_exception(bucket, rt6_ex);
> + return;
> + }
> + } else if (time_after(jiffies, rt->dst.expires)) {
> + RT6_TRACE("purging expired route %p\n", rt);
> rt6_remove_exception(bucket, rt6_ex);
> return;
> - } else if (rt->rt6i_flags & RTF_GATEWAY) {
> + }
> +
> + if (rt->rt6i_flags & RTF_GATEWAY) {
> struct neighbour *neigh;
> __u8 neigh_flags = 0;
>
> @@ -1606,11 +1613,8 @@ static void rt6_age_examine_exception(struct
> rt6_exception_bucket *bucket,
> rt6_remove_exception(bucket, rt6_ex);
> return;
> }
> - } else if (__rt6_check_expired(rt)) {
> - RT6_TRACE("purging expired route %p\n", rt);
> - rt6_remove_exception(bucket, rt6_ex);
> - return;
> }
> +
> gc_args->more++;
> }
>
> --
> 2.16.0.rc1.238.g530d649a79-goog
>
