From 58acfd714e6b02e8617448b431c2b64a2f1f0792 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 20 Dec 2017 12:28:25 +0200 Subject: [PATCH] ipv6: Honor specified parameters in fibmatch lookup Currently, parameters such as oif and source address are not taken into account during fibmatch lookup. Example (IPv4 for reference) before patch: $ ip -4 route show 192.0.2.0/24 dev dummy0 proto kernel scope link src 192.0.2.1 198.51.100.0/24 dev dummy1 proto kernel scope link src 198.51.100.1 $ ip -6 route show 2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium 2001:db8:2::/64 dev dummy1 proto kernel metric 256 pref medium fe80::/64 dev dummy0 proto kernel metric 256 pref medium fe80::/64 dev dummy1 proto kernel metric 256 pref medium $ ip -4 route get fibmatch 192.0.2.2 oif dummy0 192.0.2.0/24 dev dummy0 proto kernel scope link src 192.0.2.1 $ ip -4 route get fibmatch 192.0.2.2 oif dummy1 RTNETLINK answers: No route to host $ ip -6 route get fibmatch 2001:db8:1::2 oif dummy0 2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium $ ip -6 route get fibmatch 2001:db8:1::2 oif dummy1 2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium After: $ ip -6 route get fibmatch 2001:db8:1::2 oif dummy0 2001:db8:1::/64 dev dummy0 proto kernel metric 256 pref medium $ ip -6 route get fibmatch 2001:db8:1::2 oif dummy1 RTNETLINK answers: Network is unreachable The problem stems from the fact that the necessary route lookup flags are not set based on these parameters. Instead of duplicating the same logic for fibmatch, we can simply resolve the original route from its copy and dump it instead. Fixes: 18c3a61c4264 ("net: ipv6: RTM_GETROUTE: return matched fib result when requested") Signed-off-by: Ido Schimmel Acked-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 2bc91c349273..0458b761f3c5 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4298,19 +4298,13 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, if (!ipv6_addr_any(&fl6.saddr)) flags |= RT6_LOOKUP_F_HAS_SADDR; - if (!fibmatch) - dst = ip6_route_input_lookup(net, dev, &fl6, flags); - else - dst = ip6_route_lookup(net, &fl6, 0); + dst = ip6_route_input_lookup(net, dev, &fl6, flags); rcu_read_unlock(); } else { fl6.flowi6_oif = oif; - if (!fibmatch) - dst = ip6_route_output(net, NULL, &fl6); - else - dst = ip6_route_lookup(net, &fl6, 0); + dst = ip6_route_output(net, NULL, &fl6); } @@ -4327,6 +4321,15 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, goto errout; } + if (fibmatch && rt->dst.from) { + struct rt6_info *ort = container_of(rt->dst.from, + struct rt6_info, dst); + + dst_hold(&ort->dst); + ip6_rt_put(rt); + rt = ort; + } + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) { ip6_rt_put(rt);