[NETNS]: Inet control socket should not hold a namespace.

This is a generic requirement, so make inet_ctl_sock_create namespace
aware and create a inet_ctl_sock_destroy wrapper around
sk_release_kernel.

Signed-off-by: Denis V. Lunev <[e-mail]>
Acked-by: Arnaldo Carvalho de Melo <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/inet_common.h

···
 extern int			inet_ctl_sock_create(struct sock **sk,
 						     unsigned short family,
 						     unsigned short type,
-						     unsigned char protocol);
+						     unsigned char protocol,
+						     struct net *net);
+
+static inline void inet_ctl_sock_destroy(struct sock *sk)
+{
+	sk_release_kernel(sk);
+}
 
 #endif
 

net/dccp/ipv4.c

···
 	inet_register_protosw(&dccp_v4_protosw);
 
 	err = inet_ctl_sock_create(&dccp_v4_ctl_sk, PF_INET,
-				   SOCK_DCCP, IPPROTO_DCCP);
+				   SOCK_DCCP, IPPROTO_DCCP, &init_net);
 	if (err)
 		goto out_unregister_protosw;
 out:
···
 
 static void __exit dccp_v4_exit(void)
 {
-	sock_release(dccp_v4_ctl_sk->sk_socket);
+	inet_ctl_sock_destroy(dccp_v4_ctl_sk);
 	inet_unregister_protosw(&dccp_v4_protosw);
 	inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
 	proto_unregister(&dccp_v4_prot);

net/dccp/ipv6.c

···
 	inet6_register_protosw(&dccp_v6_protosw);
 
 	err = inet_ctl_sock_create(&dccp_v6_ctl_sk, PF_INET6,
-				   SOCK_DCCP, IPPROTO_DCCP);
+				   SOCK_DCCP, IPPROTO_DCCP, &init_net);
 	if (err != 0)
 		goto out_unregister_protosw;
 out:
···
 
 static void __exit dccp_v6_exit(void)
 {
-	sock_release(dccp_v6_ctl_sk->sk_socket);
+	inet_ctl_sock_destroy(dccp_v6_ctl_sk);
 	inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
 	inet6_unregister_protosw(&dccp_v6_protosw);
 	proto_unregister(&dccp_v6_prot);

net/ipv4/af_inet.c

···
 }
 
 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
-			 unsigned short type, unsigned char protocol)
+			 unsigned short type, unsigned char protocol,
+			 struct net *net)
 {
 	struct socket *sock;
 	int rc = sock_create_kern(family, type, protocol, &sock);
···
 		 * we do not wish this socket to see incoming packets.
 		 */
 		(*sk)->sk_prot->unhash(*sk);
+
+		sk_change_net(*sk, net);
 	}
 	return rc;
 }

net/ipv4/tcp_ipv4.c

···
 void __init tcp_v4_init(void)
 {
 	if (inet_ctl_sock_create(&tcp_sock, PF_INET, SOCK_RAW,
-				 IPPROTO_TCP) < 0)
+				 IPPROTO_TCP, &init_net) < 0)
 		panic("Failed to create the TCP control socket.\n");
 }
 

net/ipv6/tcp_ipv6.c

···
 
 static int tcpv6_net_init(struct net *net)
 {
-	int err;
-	struct sock *sk;
-
-	err = inet_ctl_sock_create(&sk, PF_INET6, SOCK_RAW, IPPROTO_TCP);
-	if (err)
-		return err;
-
-	net->ipv6.tcp_sk = sk;
-	sk_change_net(sk, net);
-	return err;
+	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
+				    SOCK_RAW, IPPROTO_TCP, net);
 }
 
 static void tcpv6_net_exit(struct net *net)
 {
-	sk_release_kernel(net->ipv6.tcp_sk);
+	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
 }
 
 static struct pernet_operations tcpv6_net_ops = {

net/sctp/protocol.c

···
 		family = PF_INET;
 
 	err = inet_ctl_sock_create(&sctp_ctl_sock, family,
-				   SOCK_SEQPACKET, IPPROTO_SCTP);
+				   SOCK_SEQPACKET, IPPROTO_SCTP, &init_net);
 	if (err < 0) {
 		printk(KERN_ERR
 		       "SCTP: Failed to create the SCTP control socket.\n");
···
 	sctp_v6_del_protocol();
 err_add_protocol:
 	sctp_v4_del_protocol();
-	sock_release(sctp_ctl_sock->sk_socket);
+	inet_ctl_sock_destroy(sctp_ctl_sock);
 err_ctl_sock_init:
 	sctp_v6_protosw_exit();
 err_v6_protosw_init:
···
 	sctp_v4_del_protocol();
 
 	/* Free the control endpoint.  */
-	sock_release(sctp_ctl_sock->sk_socket);
+	inet_ctl_sock_destroy(sctp_ctl_sock);
 
 	/* Free protosw registrations */
 	sctp_v6_protosw_exit();