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/netlink.h>
20#include <net/tcp.h>
21
22static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
23 void *_info)
24{
25 struct tcp_info *info = _info;
26
27 if (inet_sk_state_load(sk) == TCP_LISTEN) {
28 r->idiag_rqueue = sk->sk_ack_backlog;
29 r->idiag_wqueue = sk->sk_max_ack_backlog;
30 } else if (sk->sk_type == SOCK_STREAM) {
31 const struct tcp_sock *tp = tcp_sk(sk);
32
33 r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
34 r->idiag_wqueue = tp->write_seq - tp->snd_una;
35 }
36 if (info)
37 tcp_get_info(sk, info);
38}
39
40#ifdef CONFIG_TCP_MD5SIG
41static void tcp_diag_md5sig_fill(struct tcp_diag_md5sig *info,
42 const struct tcp_md5sig_key *key)
43{
44 info->tcpm_family = key->family;
45 info->tcpm_prefixlen = key->prefixlen;
46 info->tcpm_keylen = key->keylen;
47 memcpy(info->tcpm_key, key->key, key->keylen);
48
49 if (key->family == AF_INET)
50 info->tcpm_addr[0] = key->addr.a4.s_addr;
51 #if IS_ENABLED(CONFIG_IPV6)
52 else if (key->family == AF_INET6)
53 memcpy(&info->tcpm_addr, &key->addr.a6,
54 sizeof(info->tcpm_addr));
55 #endif
56}
57
58static int tcp_diag_put_md5sig(struct sk_buff *skb,
59 const struct tcp_md5sig_info *md5sig)
60{
61 const struct tcp_md5sig_key *key;
62 struct tcp_diag_md5sig *info;
63 struct nlattr *attr;
64 int md5sig_count = 0;
65
66 hlist_for_each_entry_rcu(key, &md5sig->head, node)
67 md5sig_count++;
68 if (md5sig_count == 0)
69 return 0;
70
71 attr = nla_reserve(skb, INET_DIAG_MD5SIG,
72 md5sig_count * sizeof(struct tcp_diag_md5sig));
73 if (!attr)
74 return -EMSGSIZE;
75
76 info = nla_data(attr);
77 memset(info, 0, md5sig_count * sizeof(struct tcp_diag_md5sig));
78 hlist_for_each_entry_rcu(key, &md5sig->head, node) {
79 tcp_diag_md5sig_fill(info++, key);
80 if (--md5sig_count == 0)
81 break;
82 }
83
84 return 0;
85}
86#endif
87
88static int tcp_diag_get_aux(struct sock *sk, bool net_admin,
89 struct sk_buff *skb)
90{
91#ifdef CONFIG_TCP_MD5SIG
92 if (net_admin) {
93 struct tcp_md5sig_info *md5sig;
94 int err = 0;
95
96 rcu_read_lock();
97 md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
98 if (md5sig)
99 err = tcp_diag_put_md5sig(skb, md5sig);
100 rcu_read_unlock();
101 if (err < 0)
102 return err;
103 }
104#endif
105
106 return 0;
107}
108
109static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin)
110{
111 size_t size = 0;
112
113#ifdef CONFIG_TCP_MD5SIG
114 if (net_admin && sk_fullsock(sk)) {
115 const struct tcp_md5sig_info *md5sig;
116 const struct tcp_md5sig_key *key;
117 size_t md5sig_count = 0;
118
119 rcu_read_lock();
120 md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info);
121 if (md5sig) {
122 hlist_for_each_entry_rcu(key, &md5sig->head, node)
123 md5sig_count++;
124 }
125 rcu_read_unlock();
126 size += nla_total_size(md5sig_count *
127 sizeof(struct tcp_diag_md5sig));
128 }
129#endif
130
131 return size;
132}
133
134static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
135 const struct inet_diag_req_v2 *r, struct nlattr *bc)
136{
137 inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc);
138}
139
140static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
141 const struct inet_diag_req_v2 *req)
142{
143 return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req);
144}
145
146#ifdef CONFIG_INET_DIAG_DESTROY
147static int tcp_diag_destroy(struct sk_buff *in_skb,
148 const struct inet_diag_req_v2 *req)
149{
150 struct net *net = sock_net(in_skb->sk);
151 struct sock *sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req);
152 int err;
153
154 if (IS_ERR(sk))
155 return PTR_ERR(sk);
156
157 err = sock_diag_destroy(sk, ECONNABORTED);
158
159 sock_gen_put(sk);
160
161 return err;
162}
163#endif
164
165static const struct inet_diag_handler tcp_diag_handler = {
166 .dump = tcp_diag_dump,
167 .dump_one = tcp_diag_dump_one,
168 .idiag_get_info = tcp_diag_get_info,
169 .idiag_get_aux = tcp_diag_get_aux,
170 .idiag_get_aux_size = tcp_diag_get_aux_size,
171 .idiag_type = IPPROTO_TCP,
172 .idiag_info_size = sizeof(struct tcp_info),
173#ifdef CONFIG_INET_DIAG_DESTROY
174 .destroy = tcp_diag_destroy,
175#endif
176};
177
178static int __init tcp_diag_init(void)
179{
180 return inet_diag_register(&tcp_diag_handler);
181}
182
183static void __exit tcp_diag_exit(void)
184{
185 inet_diag_unregister(&tcp_diag_handler);
186}
187
188module_init(tcp_diag_init);
189module_exit(tcp_diag_exit);
190MODULE_LICENSE("GPL");
191MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */);
192