[TCPDIAG]: Introduce inet_diag_{register,unregister}

Next changeset will rename tcp_diag to inet_diag and move the tcp_diag code out
of it and into a new tcp_diag.c, similar to the net/dccp/diag.c introduced in
this changeset, completing the transition to a generic inet_diag
infrastructure.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dccp/diag.c

@@ -0,0 +1,47 @@
+/*
+ *  net/dccp/diag.c
+ *
+ *  An implementation of the DCCP protocol
+ *  Arnaldo Carvalho de Melo <acme@mandriva.com>
+ *
+ *	This program is free software; you can redistribute it and/or modify it
+ *	under the terms of the GNU General Public License version 2 as
+ *	published by the Free Software Foundation.
+ */
+
+#include <linux/config.h>
+
+#include <linux/module.h>
+#include <linux/tcp_diag.h>
+
+#include "dccp.h"
+
+static void dccp_diag_get_info(struct sock *sk, struct tcpdiagmsg *r,
+			       void *_info)
+{
+	r->tcpdiag_rqueue = r->tcpdiag_wqueue = 0;
+}
+
+static struct inet_diag_handler dccp_diag_handler = {
+	.idiag_hashinfo	 = &dccp_hashinfo,
+	.idiag_get_info	 = dccp_diag_get_info,
+	.idiag_type	 = DCCPDIAG_GETSOCK,
+	.idiag_info_size = 0,
+};
+
+static int __init dccp_diag_init(void)
+{
+	return inet_diag_register(&dccp_diag_handler);
+}
+
+static void __exit dccp_diag_fini(void)
+{
+	inet_diag_unregister(&dccp_diag_handler);
+}
+
+module_init(dccp_diag_init);
+module_exit(dccp_diag_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
+MODULE_DESCRIPTION("DCCP inet_diag handler");