netfilter: nf_ct_dccp: add dccp_kmemdup_sysctl_table function

This patch is a cleanup. It adds dccp_kmemdup_sysctl_table to
split code into smaller chunks. Yet it prepares introduction
of nf_conntrack_proto_*_sysctl.c.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_proto_dccp.c

@@ -387,7 +387,7 @@ dccp_state_table[CT_DCCP_ROLE_MAX + 1][DCCP_PKT_SYNCACK + 1][CT_DCCP_MAX + 1] =
 /* this module per-net specifics */
 static int dccp_net_id __read_mostly;
 struct dccp_net {
-	struct nf_proto_net np;
+	struct nf_proto_net pn;
 	int dccp_loose;
 	unsigned int dccp_timeout[CT_DCCP_MAX + 1];
 };
@@ -815,26 +815,13 @@ static struct ctl_table dccp_sysctl_table[] = {
 };
 #endif /* CONFIG_SYSCTL */
 
-static int dccp_init_net(struct net *net, u_int16_t proto)
+static int dccp_kmemdup_sysctl_table(struct nf_proto_net *pn,
+				     struct dccp_net *dn)
 {
-	struct dccp_net *dn = dccp_pernet(net);
-	struct nf_proto_net *pn = (struct nf_proto_net *)dn;
-
-#ifdef CONFIG_SYSCTL
-	if (!pn->ctl_table) {
-#else
-	if (!pn->users++) {
-#endif
-		/* default values */
-		dn->dccp_loose = 1;
-		dn->dccp_timeout[CT_DCCP_REQUEST]	= 2 * DCCP_MSL;
-		dn->dccp_timeout[CT_DCCP_RESPOND]	= 4 * DCCP_MSL;
-		dn->dccp_timeout[CT_DCCP_PARTOPEN]	= 4 * DCCP_MSL;
-		dn->dccp_timeout[CT_DCCP_OPEN]		= 12 * 3600 * HZ;
-		dn->dccp_timeout[CT_DCCP_CLOSEREQ]	= 64 * HZ;
-		dn->dccp_timeout[CT_DCCP_CLOSING]	= 64 * HZ;
-		dn->dccp_timeout[CT_DCCP_TIMEWAIT]	= 2 * DCCP_MSL;
 #ifdef CONFIG_SYSCTL
+	if (pn->ctl_table)
+		return 0;
+
 	pn->ctl_table = kmemdup(dccp_sysctl_table,
 				sizeof(dccp_sysctl_table),
 				GFP_KERNEL);
@@ -850,10 +837,29 @@ static int dccp_init_net(struct net *net, u_int16_t proto)
 	pn->ctl_table[6].data = &dn->dccp_timeout[CT_DCCP_TIMEWAIT];
 	pn->ctl_table[7].data = &dn->dccp_loose;
 #endif
-	}
 	return 0;
 }
 
+static int dccp_init_net(struct net *net, u_int16_t proto)
+{
+	struct dccp_net *dn = dccp_pernet(net);
+	struct nf_proto_net *pn = &dn->pn;
+
+	if (!pn->users) {
+		/* default values */
+		dn->dccp_loose = 1;
+		dn->dccp_timeout[CT_DCCP_REQUEST]	= 2 * DCCP_MSL;
+		dn->dccp_timeout[CT_DCCP_RESPOND]	= 4 * DCCP_MSL;
+		dn->dccp_timeout[CT_DCCP_PARTOPEN]	= 4 * DCCP_MSL;
+		dn->dccp_timeout[CT_DCCP_OPEN]		= 12 * 3600 * HZ;
+		dn->dccp_timeout[CT_DCCP_CLOSEREQ]	= 64 * HZ;
+		dn->dccp_timeout[CT_DCCP_CLOSING]	= 64 * HZ;
+		dn->dccp_timeout[CT_DCCP_TIMEWAIT]	= 2 * DCCP_MSL;
+	}
+
+	return dccp_kmemdup_sysctl_table(pn, dn);
+}
+
 static struct nf_conntrack_l4proto dccp_proto4 __read_mostly = {
 	.l3proto		= AF_INET,
 	.l4proto		= IPPROTO_DCCP,