[Patch v4] IPv6: Fixed support for blackhole and prohibit routes

[Kamala R <kamala@aristanetworks.com>]

The behaviour of blackhole and prohibit routes has been corrected by setting
the input and output pointers of the dst variable appropriately. For
blackhole routes, they are set to dst_discard and to ip6_pkt_discard and
ip6_pkt_discard_out respectively for prohibit routes.

ipv6: ip6_pkt_prohibit(_out) should not depend on
CONFIG_IPV6_MULTIPLE_TABLES

We need ip6_pkt_prohibit(_out) available without
CONFIG_IPV6_MULTIPLE_TABLES

Signed-off-by: Kamala R <kamala@aristanetworks.com>
---
 net/ipv6/route.c |   22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 7faa9d5..ddb9d41 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -84,6 +84,8 @@ static int		 ip6_dst_gc(struct dst_ops *ops);
 
 static int		ip6_pkt_discard(struct sk_buff *skb);
 static int		ip6_pkt_discard_out(struct sk_buff *skb);
+static int		ip6_pkt_prohibit(struct sk_buff *skb);
+static int		ip6_pkt_prohibit_out(struct sk_buff *skb);
 static void		ip6_link_failure(struct sk_buff *skb);
 static void		ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
 					   struct sk_buff *skb, u32 mtu);
@@ -234,9 +236,6 @@ static const struct rt6_info ip6_null_entry_template = {
 
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
 
-static int ip6_pkt_prohibit(struct sk_buff *skb);
-static int ip6_pkt_prohibit_out(struct sk_buff *skb);
-
 static const struct rt6_info ip6_prohibit_entry_template = {
 	.dst = {
 		.__refcnt	= ATOMIC_INIT(1),
@@ -1565,21 +1564,24 @@ int ip6_route_add(struct fib6_config *cfg)
 				goto out;
 			}
 		}
-		rt->dst.output = ip6_pkt_discard_out;
-		rt->dst.input = ip6_pkt_discard;
 		rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP;
 		switch (cfg->fc_type) {
 		case RTN_BLACKHOLE:
 			rt->dst.error = -EINVAL;
+			rt->dst.output = dst_discard;
+			rt->dst.input = dst_discard;
 			break;
 		case RTN_PROHIBIT:
 			rt->dst.error = -EACCES;
+			rt->dst.output = ip6_pkt_prohibit_out;
+			rt->dst.input = ip6_pkt_prohibit;
 			break;
 		case RTN_THROW:
-			rt->dst.error = -EAGAIN;
-			break;
 		default:
-			rt->dst.error = -ENETUNREACH;
+			rt->dst.error = (cfg->fc_type == RTN_THROW) ? -EAGAIN
+					: -ENETUNREACH;
+			rt->dst.output = ip6_pkt_discard_out;
+			rt->dst.input = ip6_pkt_discard;
 			break;
 		}
 		goto install_route;
@@ -2144,8 +2146,6 @@ static int ip6_pkt_discard_out(struct sk_buff *skb)
 	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
 }
 
-#ifdef CONFIG_IPV6_MULTIPLE_TABLES
-
 static int ip6_pkt_prohibit(struct sk_buff *skb)
 {
 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
@@ -2157,8 +2157,6 @@ static int ip6_pkt_prohibit_out(struct sk_buff *skb)
 	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
 }
 
-#endif
-
 /*
  *	Allocate a dst for local (unicast / anycast) address.
  */
-- 
1.7.9.5