[INET_DIAG]: Move the tcp_diag interface to the proper place

With this the previous setup is back, i.e. tcp_diag can be built as a module,
as dccp_diag and both share the infrastructure available in inet_diag.

If one selects CONFIG_INET_DIAG as module CONFIG_INET_TCP_DIAG will also be
built as a module, as will CONFIG_INET_DCCP_DIAG, if CONFIG_IP_DCCP was
selected static or as a module, if CONFIG_INET_DIAG is y, being statically
linked CONFIG_INET_TCP_DIAG will follow suit and CONFIG_INET_DCCP_DIAG will be
built in the same manner as CONFIG_IP_DCCP.

Now to aim at UDP, converting it to use inet_hashinfo, so that we can use
iproute2 for UDP sockets as well.

Ah, just to show an example of this new infrastructure working for DCCP :-)

[root@qemu ~]# ./ss -dane
State      Recv-Q Send-Q Local Address:Port  Peer Address:Port
LISTEN     0      0                  *:5001             *:*     ino:942 sk:cfd503a0
ESTAB      0      0          127.0.0.1:5001     127.0.0.1:32770 ino:943 sk:cfd50a60
ESTAB      0      0          127.0.0.1:32770    127.0.0.1:5001  ino:947 sk:cfd50700
TIME-WAIT  0      0          127.0.0.1:32769    127.0.0.1:5001  timer:(timewait,3.430ms,0) ino:0 sk:cf209620

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

1 files changed, 54 insertions, 0 deletions

diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
new file mode 100644
index 000000000000..c148c1081880
--- /dev/null
+++ b/net/ipv4/tcp_diag.c
@@ -0,0 +1,54 @@
+/*
+ * tcp_diag.c   Module for monitoring TCP transport protocols sockets.
+ *
+ * Version:     $Id: tcp_diag.c,v 1.3 2002/02/01 22:01:04 davem Exp $
+ *
+ * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+
+#include <linux/module.h>
+#include <linux/inet_diag.h>
+
+#include <linux/tcp.h>
+
+#include <net/tcp.h>
+
+static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
+                              void *_info)
+{
+        const struct tcp_sock *tp = tcp_sk(sk);
+        struct tcp_info *info = _info;
+
+        r->idiag_rqueue = tp->rcv_nxt - tp->copied_seq;
+        r->idiag_wqueue = tp->write_seq - tp->snd_una;
+        if (info != NULL)
+                tcp_get_info(sk, info);
+}
+
+static struct inet_diag_handler tcp_diag_handler = {
+        .idiag_hashinfo  = &tcp_hashinfo,
+        .idiag_get_info  = tcp_diag_get_info,
+        .idiag_type      = TCPDIAG_GETSOCK,
+        .idiag_info_size = sizeof(struct tcp_info),
+};
+
+static int __init tcp_diag_init(void)
+{
+        return inet_diag_register(&tcp_diag_handler);
+}
+
+static void __exit tcp_diag_exit(void)
+{
+        inet_diag_unregister(&tcp_diag_handler);
+}
+
+module_init(tcp_diag_init);
+module_exit(tcp_diag_exit);
+MODULE_LICENSE("GPL");