[NETFILTER]: conntrack: introduce connection mark event

This patch introduces the mark event. ctnetlink can use this to know if
the mark needs to be dumped.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter/nf_conntrack_common.h

@@ -125,6 +125,10 @@ enum ip_conntrack_events
 	/* Counter highest bit has been set */
 	IPCT_COUNTER_FILLING_BIT = 11,
 	IPCT_COUNTER_FILLING = (1 << IPCT_COUNTER_FILLING_BIT),
+
+	/* Mark is set */
+	IPCT_MARK_BIT = 12,
+	IPCT_MARK = (1 << IPCT_MARK_BIT),
 };
 
 enum ip_conntrack_expect_events {

net/netfilter/xt_CONNMARK.c

@@ -52,13 +52,25 @@ target(struct sk_buff **pskb,
 	    switch(markinfo->mode) {
 	    case XT_CONNMARK_SET:
 		newmark = (*ctmark & ~markinfo->mask) | markinfo->mark;
-		if (newmark != *ctmark)
+		if (newmark != *ctmark) {
 		    *ctmark = newmark;
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+		    ip_conntrack_event_cache(IPCT_MARK, *pskb);
+#else
+		    nf_conntrack_event_cache(IPCT_MARK, *pskb);
+#endif
+		}
 		break;
 	    case XT_CONNMARK_SAVE:
 		newmark = (*ctmark & ~markinfo->mask) | ((*pskb)->nfmark & markinfo->mask);
-		if (*ctmark != newmark)
+		if (*ctmark != newmark) {
 		    *ctmark = newmark;
+#ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
+		    ip_conntrack_event_cache(IPCT_MARK, *pskb);
+#else
+		    nf_conntrack_event_cache(IPCT_MARK, *pskb);
+#endif
+		}
 		break;
 	    case XT_CONNMARK_RESTORE:
 		nfmark = (*pskb)->nfmark;