[NETFILTER] ctnetlink: Add support to identify expectations by ID's

Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NHarald Welte <laforge@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/netfilter/ip_conntrack_netlink.c

@@ -1293,6 +1293,14 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
 	if (!exp)
 		return -ENOENT;
 
+	if (cda[CTA_EXPECT_ID-1]) {
+		u_int32_t id = *(u_int32_t *)NFA_DATA(cda[CTA_EXPECT_ID-1]);
+		if (exp->id != ntohl(id)) {
+			ip_conntrack_expect_put(exp);
+			return -ENOENT;
+		}
+	}	
+
 	err = -ENOMEM;
 	skb2 = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
 	if (!skb2)