Commit bbfcd776 authored Nov 21, 2017 by Ido Schimmel Committed by David S. Miller Nov 24, 2017

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: 35103d11 ("net: ipv6 sysctl option to ignore routes when nexthop link is down")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent d7aa04a5

net/ipv6/route.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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;

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