[IPv6] rules: Use RT6_LOOKUP_F_HAS_SADDR and fix source based selectors

Fixes rt6_lookup() to provide the source address in the flow
and sets RT6_LOOKUP_F_HAS_SADDR whenever it is present in
the flow.

Avoids unnecessary prefix comparisons by checking for a prefix
length first.

Fixes the rule logic to not match packets if a source selector
has been specified but no source address is available.

Thanks to Kim Nordlund <kim.nordlund@nokia.com> for working
on this patch with me.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 4 deletions

diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index d8c1057e8b00..1896ecb52899 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -117,12 +117,15 @@ static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 {
         struct fib6_rule *r = (struct fib6_rule *) rule;
 
-        if (!ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
+        if (r->dst.plen &&
+            !ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
                 return 0;
 
-        if ((flags & RT6_LOOKUP_F_HAS_SADDR) &&
-            !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen))
-                return 0;
+        if (r->src.plen) {
+                if (!(flags & RT6_LOOKUP_F_HAS_SADDR) ||
+                    !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen))
+                        return 0;
+        }
 
         if (r->tclass && r->tclass != ((ntohl(fl->fl6_flowlabel) >> 20) & 0xff))
                 return 0;