[PATCH net-next 02/18] ipv6: Mark dead nexthops with appropriate flags

[Ido Schimmel]

When a netdev is put administratively down or unregistered all the
nexthops using it as their nexthop device should be marked with the
'dead' and 'linkdown' flags.

Currently, when a route is dumped its nexthop device is tested and the
flags are set accordingly. A similar check is performed during route
lookup.

Instead, we can simply mark the nexthops based on netdev events and
avoid checking the netdev's state during route dump and lookup.

Signed-off-by: Ido Schimmel 
---
 net/ipv6/route.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index c557362daa23..f5eda0aeab55 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -3473,8 +3473,10 @@ static int fib6_ifdown(struct rt6_info *rt, void *arg)
if (rt->dst.dev == dev &&
rt != adn->net->ipv6.ip6_null_entry &&
(rt->rt6i_nsiblings == 0 || netdev_unregistering(dev) ||
-!rt->rt6i_idev->cnf.ignore_routes_with_linkdown))
+!rt->rt6i_idev->cnf.ignore_routes_with_linkdown)) {
+   rt->rt6i_nh_flags |= (RTNH_F_DEAD | RTNH_F_LINKDOWN);
return -1;
+   }
 
return 0;
 }
-- 
2.14.3

Re: [PATCH net-next 02/18] ipv6: Mark dead nexthops with appropriate flags

[David Ahern]

On 1/7/18 3:45 AM, Ido Schimmel wrote:
> When a netdev is put administratively down or unregistered all the
> nexthops using it as their nexthop device should be marked with the
> 'dead' and 'linkdown' flags.
> 
> Currently, when a route is dumped its nexthop device is tested and the
> flags are set accordingly. A similar check is performed during route
> lookup.
> 
> Instead, we can simply mark the nexthops based on netdev events and
> avoid checking the netdev's state during route dump and lookup.
> 
> Signed-off-by: Ido Schimmel 
> ---
>  net/ipv6/route.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 

Acked-by: David Ahern