[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, 16 insertions, 3 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d6b4b4f48d18..a1b0f075462e 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -529,13 +529,17 @@ struct rt6_info *rt6_lookup(struct in6_addr *daddr, struct in6_addr *saddr,
                 .nl_u = {
                         .ip6_u = {
                                 .daddr = *daddr,
-                                /* TODO: saddr */
                         },
                 },
         };
         struct dst_entry *dst;
         int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
 
+        if (saddr) {
+                memcpy(&fl.fl6_src, saddr, sizeof(*saddr));
+                flags |= RT6_LOOKUP_F_HAS_SADDR;
+        }
+
         dst = fib6_rule_lookup(&fl, flags, ip6_pol_route_lookup);
         if (dst->error == 0)
                 return (struct rt6_info *) dst;
@@ -697,6 +701,7 @@ out2:
 void ip6_route_input(struct sk_buff *skb)
 {
         struct ipv6hdr *iph = skb->nh.ipv6h;
+        int flags = RT6_LOOKUP_F_HAS_SADDR;
         struct flowi fl = {
                 .iif = skb->dev->ifindex,
                 .nl_u = {
@@ -711,7 +716,9 @@ void ip6_route_input(struct sk_buff *skb)
                 },
                 .proto = iph->nexthdr,
         };
-        int flags = rt6_need_strict(&iph->daddr) ? RT6_LOOKUP_F_IFACE : 0;
+
+        if (rt6_need_strict(&iph->daddr))
+                flags |= RT6_LOOKUP_F_IFACE;
 
         skb->dst = fib6_rule_lookup(&fl, flags, ip6_pol_route_input);
 }
@@ -794,6 +801,9 @@ struct dst_entry * ip6_route_output(struct sock *sk, struct flowi *fl)
         if (rt6_need_strict(&fl->fl6_dst))
                 flags |= RT6_LOOKUP_F_IFACE;
 
+        if (!ipv6_addr_any(&fl->fl6_src))
+                flags |= RT6_LOOKUP_F_HAS_SADDR;
+
         return fib6_rule_lookup(fl, flags, ip6_pol_route_output);
 }
 
@@ -1345,6 +1355,7 @@ static struct rt6_info *ip6_route_redirect(struct in6_addr *dest,
                                            struct in6_addr *gateway,
                                            struct net_device *dev)
 {
+        int flags = RT6_LOOKUP_F_HAS_SADDR;
         struct ip6rd_flowi rdfl = {
                 .fl = {
                         .oif = dev->ifindex,
@@ -1357,7 +1368,9 @@ static struct rt6_info *ip6_route_redirect(struct in6_addr *dest,
                 },
                 .gateway = *gateway,
         };
-        int flags = rt6_need_strict(dest) ? RT6_LOOKUP_F_IFACE : 0;
+
+        if (rt6_need_strict(dest))
+                flags |= RT6_LOOKUP_F_IFACE;
 
         return (struct rt6_info *)fib6_rule_lookup((struct flowi *)&rdfl, flags, __ip6_route_redirect);
 }