[PATCH AUTOSEL for 4.15 058/124] ipv6: Set nexthop flags during route creation

[Sasha Levin]

From: Ido Schimmel <idosch@xxxxxxxxxxxx>

[ Upstream commit 5609b80a37f69f796548339e675256188b29c17d ]

It is valid to install routes with a nexthop device that does not have a
carrier, so we need to make sure they're marked accordingly.

As explained in the previous patch, host and anycast routes are never
marked with the 'linkdown' flag.

Note that reject routes are unaffected, as these use the loopback device
which always has a carrier.

Signed-off-by: Ido Schimmel <idosch@xxxxxxxxxxxx>
Acked-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 net/ipv6/route.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index a560fb1d0230..b2d6377f1ef5 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2750,6 +2750,9 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
 	rt->rt6i_flags = cfg->fc_flags;
 
 install_route:
+	if (!(rt->rt6i_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
+	    !netif_carrier_ok(dev))
+		rt->rt6i_nh_flags |= RTNH_F_LINKDOWN;
 	rt->dst.dev = dev;
 	rt->rt6i_idev = idev;
 	rt->rt6i_table = table;
-- 
2.14.1