[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>

4 files changed, 63 insertions, 29 deletions

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 019e88d8f29e..e55136ae09f4 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -413,8 +413,8 @@ config INET_TUNNEL
           
           If unsure, say Y.
 
-config IP_INET_DIAG
-        tristate "IP: INET socket monitoring interface"
+config INET_DIAG
+        tristate "INET: socket monitoring interface"
         default y
         ---help---
           Support for INET (TCP, DCCP, etc) socket monitoring interface used by
@@ -423,6 +423,10 @@ config IP_INET_DIAG
           
           If unsure, say Y.
 
+config INET_TCP_DIAG
+        depends on INET_DIAG
+        def_tristate INET_DIAG
+
 config TCP_CONG_ADVANCED
         bool "TCP: advanced congestion control"
         ---help---
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index fe5accbb56bf..f0435d00db6b 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -30,8 +30,9 @@ obj-$(CONFIG_IP_ROUTE_MULTIPATH_WRANDOM) += multipath_wrandom.o
 obj-$(CONFIG_IP_ROUTE_MULTIPATH_DRR) += multipath_drr.o
 obj-$(CONFIG_NETFILTER) += netfilter/
 obj-$(CONFIG_IP_VS) += ipvs/
-obj-$(CONFIG_IP_INET_DIAG) += inet_diag.o 
+obj-$(CONFIG_INET_DIAG) += inet_diag.o 
 obj-$(CONFIG_IP_ROUTE_MULTIPATH_CACHED) += multipath.o
+obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o
 obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o
 obj-$(CONFIG_TCP_CONG_WESTWOOD) += tcp_westwood.o
 obj-$(CONFIG_TCP_CONG_HSTCP) += tcp_highspeed.o
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 3bd510941da0..1880ad8575d8 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -797,25 +797,6 @@ static void inet_diag_rcv(struct sock *sk, int len)
         }
 }
 
-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 DEFINE_SPINLOCK(inet_diag_register_lock);
 
 int inet_diag_register(const struct inet_diag_handler *h)
@@ -864,19 +845,13 @@ static int __init inet_diag_init(void)
                 goto out;
 
         memset(inet_diag_table, 0, inet_diag_table_size);
-
         idiagnl = netlink_kernel_create(NETLINK_INET_DIAG, inet_diag_rcv,
                                         THIS_MODULE);
         if (idiagnl == NULL)
                 goto out_free_table;
-
-        err = inet_diag_register(&tcp_diag_handler);
-        if (err)
-                goto out_sock_release;
+        err = 0;
 out:
         return err;
-out_sock_release:
-        sock_release(idiagnl->sk_socket);
 out_free_table:
         kfree(inet_diag_table);
         goto out;
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");