netfilter: nf_ct_dccp: add missing DCCP protocol changes in event cache

This patch adds the missing protocol state-change event reporting
for DCCP.

$ sudo conntrack -E
    [NEW] dccp     33 240 src=192.168.0.2 dst=192.168.1.2 sport=57040 dport=5001 [UNREPLIED] src=192.168.1.2 dst=192.168.1.100 sport=5001 dport=57040

With this patch:

$ sudo conntrack -E
    [NEW] dccp     33 240 REQUEST src=192.168.0.2 dst=192.168.1.2 sport=57040 dport=5001 [UNREPLIED] src=192.168.1.2 dst=192.168.1.100 sport=5001 dport=57040
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

net/netfilter/nf_conntrack_proto_dccp.c

@@ -22,6 +22,7 @@
 #include <linux/netfilter/nfnetlink_conntrack.h>
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
 #include <net/netfilter/nf_log.h>
 
 static DEFINE_RWLOCK(dccp_lock);
@@ -553,6 +554,9 @@ static int dccp_packet(struct nf_conn *ct, const struct sk_buff *skb,
 	ct->proto.dccp.state = new_state;
 	write_unlock_bh(&dccp_lock);
 
+	if (new_state != old_state)
+		nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
+
 	dn = dccp_pernet(net);
 	nf_ct_refresh_acct(ct, ctinfo, skb, dn->dccp_timeout[new_state]);