ipvs: stop ICMP from FORWARD to local

 	Delivering locally ICMP from FORWARD hook is not supported.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

net/netfilter/ipvs/ip_vs_core.c

@@ -48,6 +48,7 @@
 #ifdef CONFIG_IP_VS_IPV6
 #include <net/ipv6.h>
 #include <linux/netfilter_ipv6.h>
+#include <net/ip6_route.h>
 #endif
 
 #include <net/ip_vs.h>
@@ -1191,7 +1192,14 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
 	if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
 		offset += 2 * sizeof(__u16);
 	verdict = ip_vs_icmp_xmit(skb, cp, pp, offset);
-	/* do not touch skb anymore */
+	/* LOCALNODE from FORWARD hook is not supported */
+	if (verdict == NF_ACCEPT && hooknum == NF_INET_FORWARD &&
+	    skb_rtable(skb)->rt_flags & RTCF_LOCAL) {
+		IP_VS_DBG(1, "%s(): "
+			  "local delivery to %pI4 but in FORWARD\n",
+			  __func__, &skb_rtable(skb)->rt_dst);
+		verdict = NF_DROP;
+	}
 
   out:
 	__ip_vs_conn_put(cp);
@@ -1212,6 +1220,7 @@ ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
 	struct ip_vs_protocol *pp;
 	unsigned int offset, verdict;
 	union nf_inet_addr snet;
+	struct rt6_info *rt;
 
 	*related = 1;
 
@@ -1290,7 +1299,15 @@ ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
 	    IPPROTO_SCTP == cih->nexthdr)
 		offset += 2 * sizeof(__u16);
 	verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset);
-	/* do not touch skb anymore */
+	/* LOCALNODE from FORWARD hook is not supported */
+	if (verdict == NF_ACCEPT && hooknum == NF_INET_FORWARD &&
+	    (rt = (struct rt6_info *) skb_dst(skb)) &&
+	    rt->rt6i_dev && rt->rt6i_dev->flags & IFF_LOOPBACK) {
+		IP_VS_DBG(1, "%s(): "
+			  "local delivery to %pI6 but in FORWARD\n",
+			  __func__, &rt->rt6i_dst);
+		verdict = NF_DROP;
+	}
 
 	__ip_vs_conn_put(cp);