From bbfcd77631573ac4a9f57eb6169e04256a111bc1 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Tue, 21 Nov 2017 09:50:12 +0200 Subject: [PATCH] ipv6: Do not consider linkdown nexthops during multipath When the 'ignore_routes_with_linkdown' sysctl is set, we should not consider linkdown nexthops during route lookup. While the code correctly verifies that the initially selected route ('match') has a carrier, it does not perform the same check in the subsequent multipath selection, resulting in a potential packet loss. In case the chosen route does not have a carrier and the sysctl is set, choose the initially selected route. Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") Signed-off-by: Ido Schimmel Acked-by: David Ahern Acked-by: Andy Gospodarek Signed-off-by: David S. Miller --- net/ipv6/route.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 05eb7bc..0363db9 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -472,6 +472,11 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match, &match->rt6i_siblings, rt6i_siblings) { route_choosen--; if (route_choosen == 0) { + struct inet6_dev *idev = sibling->rt6i_idev; + + if (!netif_carrier_ok(sibling->dst.dev) && + idev->cnf.ignore_routes_with_linkdown) + break; if (rt6_score_route(sibling, oif, strict) < 0) break; match = sibling; -- 2.7.4