[RFC,PATCH] sequence numbering for ctnetlink events

This patch adds sequence numbering to ctnetlink event messages
send to userspace.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Index: net-2.6.18.git/net/ipv4/netfilter/ip_conntrack_netlink.c
===================================================================
--- net-2.6.18.git.orig/net/ipv4/netfilter/ip_conntrack_netlink.c	2006-06-06 16:08:59.000000000 +0200
+++ net-2.6.18.git/net/ipv4/netfilter/ip_conntrack_netlink.c	2006-06-06 16:55:44.000000000 +0200
@@ -304,6 +304,8 @@
 }
 
 #ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+static atomic_t ip_conntrack_seq = ATOMIC_INIT(0);
+
 static int ctnetlink_conntrack_event(struct notifier_block *this,
                                      unsigned long events, void *ptr)
 {
@@ -349,7 +351,8 @@
 	b = skb->tail;
 
 	type |= NFNL_SUBSYS_CTNETLINK << 8;
-	nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
+	nlh   = NLMSG_PUT(skb, 0, atomic_add_return(1, &ip_conntrack_seq), 
+			  type, sizeof(struct nfgenmsg));
 	nfmsg = NLMSG_DATA(nlh);
 
 	nlh->nlmsg_flags    = flags;
@@ -1239,6 +1242,8 @@
 }
 
 #ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+static atomic_t ip_conntrack_exp_seq = ATOMIC_INIT(0);
+
 static int ctnetlink_expect_event(struct notifier_block *this,
 				  unsigned long events, void *ptr)
 {
@@ -1263,7 +1268,8 @@
 	b = skb->tail;
 
 	type |= NFNL_SUBSYS_CTNETLINK_EXP << 8;
-	nlh   = NLMSG_PUT(skb, 0, 0, type, sizeof(struct nfgenmsg));
+	nlh   = NLMSG_PUT(skb, 0, atomic_add_return(1, &ip_conntrack_exp_seq),
+			  type, sizeof(struct nfgenmsg));
 	nfmsg = NLMSG_DATA(nlh);
 
 	nlh->nlmsg_flags    = flags;