From a435a07f9164dda7c0c26e8ad758881f4bafc127 Mon Sep 17 00:00:00 2001 From: Vincent Bernat Date: Sun, 18 Sep 2016 17:46:07 +0200 Subject: [PATCH] net: ipv6: fallback to full lookup if table lookup is unsuitable Commit 8c14586fc320 ("net: ipv6: Use passed in table for nexthop lookups") introduced a regression: insertion of an IPv6 route in a table not containing the appropriate connected route for the gateway but which contained a non-connected route (like a default gateway) fails while it was previously working: $ ip link add eth0 type dummy $ ip link set up dev eth0 $ ip addr add 2001:db8::1/64 dev eth0 $ ip route add ::/0 via 2001:db8::5 dev eth0 table 20 $ ip route add 2001:db8:cafe::1/128 via 2001:db8::6 dev eth0 table 20 RTNETLINK answers: No route to host $ ip -6 route show table 20 default via 2001:db8::5 dev eth0 metric 1024 pref medium After this patch, we get: $ ip route add 2001:db8:cafe::1/128 via 2001:db8::6 dev eth0 table 20 $ ip -6 route show table 20 2001:db8:cafe::1 via 2001:db8::6 dev eth0 metric 1024 pref medium default via 2001:db8::5 dev eth0 metric 1024 pref medium Fixes: 8c14586fc320 ("net: ipv6: Use passed in table for nexthop lookups") Signed-off-by: Vincent Bernat Acked-by: David Ahern Tested-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 4981755..e3a224b 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1986,9 +1986,18 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg) if (!(gwa_type & IPV6_ADDR_UNICAST)) goto out; - if (cfg->fc_table) + if (cfg->fc_table) { grt = ip6_nh_lookup_table(net, cfg, gw_addr); + if (grt) { + if (grt->rt6i_flags & RTF_GATEWAY || + (dev && dev != grt->dst.dev)) { + ip6_rt_put(grt); + grt = NULL; + } + } + } + if (!grt) grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1); -- 2.7.4