[PATCH] net: ipv6: fallback to full lookup if table lookup is unsuitable
flat view
STALE3679d
From: Vincent Bernat <hidden>
Date: 2016-09-16 12:55:45
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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
Signed-off-by: Vincent Bernat <redacted>
---
net/ipv6/route.c | 48 +++++++++++++++++++++++++++---------------------
1 file changed, 27 insertions(+), 21 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ad4a7ff301fc..c2aaddcfed9e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -1808,6 +1808,30 @@ static struct rt6_info *ip6_nh_lookup_table(struct net *net, return rt; } +static int ip6_nh_valid(struct rt6_info *grt, + struct net_device **dev, struct inet6_dev **idev) { + int ret = 0; + + if (!grt) + goto out; + if (grt->rt6i_flags & RTF_GATEWAY) + goto out; + if (*dev) { + if (*dev != grt->dst.dev) + goto out; + } else { + *dev = grt->dst.dev; + *idev = grt->rt6i_idev; + dev_hold(*dev); + in6_dev_hold(*idev); + } + ret = 1; +out: + if (grt) + ip6_rt_put(grt); + return ret; +} + static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg) { struct net *net = cfg->fc_nlinfo.nl_net;
@@ -1991,33 +2015,15 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg) if (!(gwa_type & IPV6_ADDR_UNICAST)) goto out; + err = -EHOSTUNREACH; if (cfg->fc_table) grt = ip6_nh_lookup_table(net, cfg, gw_addr); - - if (!grt) + if (!ip6_nh_valid(grt, &dev, &idev)) { grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1); - - err = -EHOSTUNREACH; - if (!grt) - goto out; - if (dev) { - if (dev != grt->dst.dev) { - ip6_rt_put(grt); + if (!ip6_nh_valid(grt, &dev, &idev)) goto out; - } - } else { - dev = grt->dst.dev; - idev = grt->rt6i_idev; - dev_hold(dev); - in6_dev_hold(grt->rt6i_idev); } - if (!(grt->rt6i_flags & RTF_GATEWAY)) - err = 0; - ip6_rt_put(grt); - - if (err) - goto out; } err = -EINVAL; if (!dev || (dev->flags & IFF_LOOPBACK))
--
2.9.3