xref: /linux/net/ipv4/tcp_diag.c (revision 5e8c0fb6a95728b852d56c0a9244425d474670c0)
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 
19 static 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 != NULL)
33 		tcp_get_info(sk, info);
34 }
35 
36 static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
37 			  struct inet_diag_req_v2 *r, struct nlattr *bc)
38 {
39 	inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc);
40 }
41 
42 static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
43 			     struct inet_diag_req_v2 *req)
44 {
45 	return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req);
46 }
47 
48 static 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 
55 static int __init tcp_diag_init(void)
56 {
57 	return inet_diag_register(&tcp_diag_handler);
58 }
59 
60 static void __exit tcp_diag_exit(void)
61 {
62 	inet_diag_unregister(&tcp_diag_handler);
63 }
64 
65 module_init(tcp_diag_init);
66 module_exit(tcp_diag_exit);
67 MODULE_LICENSE("GPL");
68 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);
69