1/*
2 * tcp_diag.c	Module for monitoring TCP transport protocols sockets.
3 *
4 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
5 *
6 *	This program is free software; you can redistribute it and/or
7 *      modify it under the terms of the GNU General Public License
8 *      as published by the Free Software Foundation; either version
9 *      2 of the License, or (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/inet_diag.h>
14
15#include <linux/tcp.h>
16
17#include <net/tcp.h>
18
19static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
20			      void *_info)
21{
22	const struct tcp_sock *tp = tcp_sk(sk);
23	struct tcp_info *info = _info;
24
25	if (sk->sk_state == TCP_LISTEN) {
26		r->idiag_rqueue = sk->sk_ack_backlog;
27		r->idiag_wqueue = sk->sk_max_ack_backlog;
28	} else {
29		r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
30		r->idiag_wqueue = tp->write_seq - tp->snd_una;
31	}
32	if (info)
33		tcp_get_info(sk, info);
34}
35
36static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
37			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
38{
39	inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc);
40}
41
42static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
43			     const struct inet_diag_req_v2 *req)
44{
45	return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req);
46}
47
48static const struct inet_diag_handler tcp_diag_handler = {
49	.dump		 = tcp_diag_dump,
50	.dump_one	 = tcp_diag_dump_one,
51	.idiag_get_info	 = tcp_diag_get_info,
52	.idiag_type	 = IPPROTO_TCP,
53};
54
55static int __init tcp_diag_init(void)
56{
57	return inet_diag_register(&tcp_diag_handler);
58}
59
60static void __exit tcp_diag_exit(void)
61{
62	inet_diag_unregister(&tcp_diag_handler);
63}
64
65module_init(tcp_diag_init);
66module_exit(tcp_diag_exit);
67MODULE_LICENSE("GPL");
68MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);
69