xref: /linux/net/ipv4/tcp_diag.c (revision a3a4a816b4b194c45d0217e8b9e08b2639802cda)
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/net.h>
14 #include <linux/sock_diag.h>
15 #include <linux/inet_diag.h>
16 
17 #include <linux/tcp.h>
18 
19 #include <net/tcp.h>
20 
21 static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
22 			      void *_info)
23 {
24 	struct tcp_info *info = _info;
25 
26 	if (sk_state_load(sk) == TCP_LISTEN) {
27 		r->idiag_rqueue = sk->sk_ack_backlog;
28 		r->idiag_wqueue = sk->sk_max_ack_backlog;
29 	} else if (sk->sk_type == SOCK_STREAM) {
30 		const struct tcp_sock *tp = tcp_sk(sk);
31 
32 		r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
33 		r->idiag_wqueue = tp->write_seq - tp->snd_una;
34 	}
35 	if (info)
36 		tcp_get_info(sk, info);
37 }
38 
39 static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
40 			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
41 {
42 	inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc);
43 }
44 
45 static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
46 			     const struct inet_diag_req_v2 *req)
47 {
48 	return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req);
49 }
50 
51 #ifdef CONFIG_INET_DIAG_DESTROY
52 static int tcp_diag_destroy(struct sk_buff *in_skb,
53 			    const struct inet_diag_req_v2 *req)
54 {
55 	struct net *net = sock_net(in_skb->sk);
56 	struct sock *sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req);
57 	int err;
58 
59 	if (IS_ERR(sk))
60 		return PTR_ERR(sk);
61 
62 	err = sock_diag_destroy(sk, ECONNABORTED);
63 
64 	sock_gen_put(sk);
65 
66 	return err;
67 }
68 #endif
69 
70 static const struct inet_diag_handler tcp_diag_handler = {
71 	.dump		 = tcp_diag_dump,
72 	.dump_one	 = tcp_diag_dump_one,
73 	.idiag_get_info	 = tcp_diag_get_info,
74 	.idiag_type	 = IPPROTO_TCP,
75 	.idiag_info_size = sizeof(struct tcp_info),
76 #ifdef CONFIG_INET_DIAG_DESTROY
77 	.destroy	 = tcp_diag_destroy,
78 #endif
79 };
80 
81 static int __init tcp_diag_init(void)
82 {
83 	return inet_diag_register(&tcp_diag_handler);
84 }
85 
86 static void __exit tcp_diag_exit(void)
87 {
88 	inet_diag_unregister(&tcp_diag_handler);
89 }
90 
91 module_init(tcp_diag_init);
92 module_exit(tcp_diag_exit);
93 MODULE_LICENSE("GPL");
94 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);
95