From e16e888b525503be05b3aea64190e8b3bdef44d0 Mon Sep 17 00:00:00 2001 From: Markus Stenberg Date: Tue, 5 May 2015 13:36:59 +0300 Subject: ipv6: Fixed source specific default route handling. If there are only IPv6 source specific default routes present, the host gets -ENETUNREACH on e.g. connect() because ip6_dst_lookup_tail calls ip6_route_output first, and given source address any, it fails, and ip6_route_get_saddr is never called. The change is to use the ip6_route_get_saddr, even if the initial ip6_route_output fails, and then doing ip6_route_output _again_ after we have appropriate source address available. Note that this is '99% fix' to the problem; a correct fix would be to do route lookups only within addrconf.c when picking a source address, and never call ip6_route_output before source address has been populated. Signed-off-by: Markus Stenberg Signed-off-by: David S. Miller --- net/ipv6/ip6_output.c | 39 +++++++++++++++++++++++++++++++-------- net/ipv6/route.c | 5 +++-- 2 files changed, 34 insertions(+), 10 deletions(-) (limited to 'net') diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 7fde1f265c90..c21777565c58 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -886,22 +886,45 @@ static int ip6_dst_lookup_tail(struct sock *sk, #endif int err; - if (!*dst) - *dst = ip6_route_output(net, sk, fl6); - - err = (*dst)->error; - if (err) - goto out_err_release; + /* The correct way to handle this would be to do + * ip6_route_get_saddr, and then ip6_route_output; however, + * the route-specific preferred source forces the + * ip6_route_output call _before_ ip6_route_get_saddr. + * + * In source specific routing (no src=any default route), + * ip6_route_output will fail given src=any saddr, though, so + * that's why we try it again later. + */ + if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) { + struct rt6_info *rt; + bool had_dst = *dst != NULL; - if (ipv6_addr_any(&fl6->saddr)) { - struct rt6_info *rt = (struct rt6_info *) *dst; + if (!had_dst) + *dst = ip6_route_output(net, sk, fl6); + rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; err = ip6_route_get_saddr(net, rt, &fl6->daddr, sk ? inet6_sk(sk)->srcprefs : 0, &fl6->saddr); if (err) goto out_err_release; + + /* If we had an erroneous initial result, pretend it + * never existed and let the SA-enabled version take + * over. + */ + if (!had_dst && (*dst)->error) { + dst_release(*dst); + *dst = NULL; + } } + if (!*dst) + *dst = ip6_route_output(net, sk, fl6); + + err = (*dst)->error; + if (err) + goto out_err_release; + #ifdef CONFIG_IPV6_OPTIMISTIC_DAD /* * Here if the dst entry we've looked up diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 5c48293ff062..d3588885f097 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2245,9 +2245,10 @@ int ip6_route_get_saddr(struct net *net, unsigned int prefs, struct in6_addr *saddr) { - struct inet6_dev *idev = ip6_dst_idev((struct dst_entry *)rt); + struct inet6_dev *idev = + rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL; int err = 0; - if (rt->rt6i_prefsrc.plen) + if (rt && rt->rt6i_prefsrc.plen) *saddr = rt->rt6i_prefsrc.addr; else err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL, -- cgit v1.2.1