netfilter: nf_conntrack: properly account terminating packets

Currently the last packet of a connection isn't accounted when its causing
abnormal termination.

Introduces nf_ct_kill_acct() which increments the accounting counters on
conntrack kill. The new function was necessary, because there are calls
to nf_ct_kill() which don't need accounting:

nf_conntrack_proto_tcp.c line ~847:
Kills ct and returns NF_REPEAT. We don't want to count twice.

nf_conntrack_proto_tcp.c line ~880:
Kills ct and returns NF_DROP. I think we don't want to count dropped
packets.

nf_conntrack_netlink.c line ~824:
As far as I can see ctnetlink_del_conntrack() is used to destroy a
conntrack on behalf of the user. There is an sk_buff, but I don't think
this is an actual packet. Incrementing counters here is therefore not
desired.

Signed-off-by: Fabian Hugelshofer <hugelshofer2006@gmx.ch>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_proto_dccp.c b/net/netfilter/nf_conntrack_proto_dccp.c
index 223742f..e7866dd 100644
--- a/net/netfilter/nf_conntrack_proto_dccp.c
+++ b/net/netfilter/nf_conntrack_proto_dccp.c
@@ -475,7 +475,7 @@
 	if (type == DCCP_PKT_RESET &&
 	    !test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) {
 		/* Tear down connection immediately if only reply is a RESET */
-		nf_ct_kill(ct);
+		nf_ct_kill_acct(ct, ctinfo, skb);
 		return NF_ACCEPT;
 	}