netfilter: nf_conntrack: don't always initialize ct->proto

ct->proto is big(60 bytes) due to structure ip_ct_tcp, and we don't need
to initialize the whole for all the other protocols. This patch moves
proto to the end of structure nf_conn, and pushes the initialization down
to the individual protocols.

Signed-off-by: Changli Gao <[e-mail]>
Signed-off-by: Patrick McHardy <[e-mail]>

include/net/netfilter/nf_conntrack.h

···
 	u_int32_t secmark;
 #endif
 
-	/* Storage reserved for other modules: */
-	union nf_conntrack_proto proto;
-
 	/* Extensions */
 	struct nf_ct_ext *ext;
 #ifdef CONFIG_NET_NS
 	struct net *ct_net;
 #endif
+
+	/* Storage reserved for other modules, must be the last member */
+	union nf_conntrack_proto proto;
 };
 
 static inline struct nf_conn *

net/netfilter/nf_conntrack_core.c

···
 	 * and ct->tuplehash[IP_CT_DIR_REPLY].hnnode.next unchanged.
 	 */
 	memset(&ct->tuplehash[IP_CT_DIR_MAX], 0,
-	       sizeof(*ct) - offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
+	       offsetof(struct nf_conn, proto) -
+	       offsetof(struct nf_conn, tuplehash[IP_CT_DIR_MAX]));
 	spin_lock_init(&ct->lock);
 	ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple = *orig;
 	ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode.pprev = NULL;

net/netfilter/nf_conntrack_netlink.c

···
 	}
 #endif
 
+	memset(&ct->proto, 0, sizeof(ct->proto));
 	if (cda[CTA_PROTOINFO]) {
 		err = ctnetlink_change_protoinfo(ct, cda);
 		if (err < 0)

net/netfilter/nf_conntrack_proto_dccp.c

···
 	ct->proto.dccp.role[IP_CT_DIR_ORIGINAL] = CT_DCCP_ROLE_CLIENT;
 	ct->proto.dccp.role[IP_CT_DIR_REPLY] = CT_DCCP_ROLE_SERVER;
 	ct->proto.dccp.state = CT_DCCP_NONE;
+	ct->proto.dccp.last_pkt = DCCP_PKT_REQUEST;
+	ct->proto.dccp.last_dir = IP_CT_DIR_ORIGINAL;
+	ct->proto.dccp.handshake_seq = 0;
 	return true;
 
 out_invalid:

net/netfilter/nf_conntrack_proto_sctp.c

···
 	    test_bit(SCTP_CID_COOKIE_ACK, map))
 		return false;
 
+	memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 	new_state = SCTP_CONNTRACK_MAX;
 	for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 		/* Don't need lock here: this conntrack not in circulation yet */

net/netfilter/nf_conntrack_proto_tcp.c

···
 	BUG_ON(th == NULL);
 
 	/* Don't need lock here: this conntrack not in circulation yet */
-	new_state
-		= tcp_conntracks[0][get_conntrack_index(th)]
-		[TCP_CONNTRACK_NONE];
+	new_state = tcp_conntracks[0][get_conntrack_index(th)][TCP_CONNTRACK_NONE];
 
 	/* Invalid: delete conntrack */
 	if (new_state >= TCP_CONNTRACK_MAX) {
···
 	}
 
 	if (new_state == TCP_CONNTRACK_SYN_SENT) {
+		memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp));
 		/* SYN packet */
 		ct->proto.tcp.seen[0].td_end =
 			segment_seq_plus_len(ntohl(th->seq), skb->len,
···
 			ct->proto.tcp.seen[0].td_end;
 
 		tcp_options(skb, dataoff, th, &ct->proto.tcp.seen[0]);
-		ct->proto.tcp.seen[1].flags = 0;
 	} else if (nf_ct_tcp_loose == 0) {
 		/* Don't try to pick up connections. */
 		return false;
 	} else {
+		memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp));
 		/*
 		 * We are in the middle of a connection,
 		 * its history is lost for us.
···
 		ct->proto.tcp.seen[0].td_maxend =
 			ct->proto.tcp.seen[0].td_end +
 			ct->proto.tcp.seen[0].td_maxwin;
-		ct->proto.tcp.seen[0].td_scale = 0;
 
 		/* We assume SACK and liberal window checking to handle
 		 * window scaling */
···
 					      IP_CT_TCP_FLAG_BE_LIBERAL;
 	}
 
-	ct->proto.tcp.seen[1].td_end = 0;
-	ct->proto.tcp.seen[1].td_maxend = 0;
-	ct->proto.tcp.seen[1].td_maxwin = 0;
-	ct->proto.tcp.seen[1].td_scale = 0;
-
 	/* tcp_packet will set them */
-	ct->proto.tcp.state = TCP_CONNTRACK_NONE;
 	ct->proto.tcp.last_index = TCP_NONE_SET;
 
 	pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i "