Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * udp_diag.c Module for monitoring UDP transport protocols sockets.
4 *
5 * Authors: Pavel Emelyanov, <xemul@parallels.com>
6 */
7
8
9#include <linux/module.h>
10#include <linux/inet_diag.h>
11#include <linux/udp.h>
12#include <net/udp.h>
13#include <net/udplite.h>
14#include <linux/sock_diag.h>
15
16static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
17 struct netlink_callback *cb,
18 const struct inet_diag_req_v2 *req,
19 bool net_admin)
20{
21 if (!inet_diag_bc_sk(cb->data, sk))
22 return 0;
23
24 return inet_sk_diag_fill(sk, NULL, skb, cb, req, NLM_F_MULTI,
25 net_admin);
26}
27
28static int udp_dump_one(struct udp_table *tbl,
29 struct netlink_callback *cb,
30 const struct inet_diag_req_v2 *req)
31{
32 struct sk_buff *in_skb = cb->skb;
33 int err;
34 struct sock *sk = NULL;
35 struct sk_buff *rep;
36 struct net *net = sock_net(in_skb->sk);
37
38 rcu_read_lock();
39 if (req->sdiag_family == AF_INET)
40 /* src and dst are swapped for historical reasons */
41 sk = __udp4_lib_lookup(net,
42 req->id.idiag_src[0], req->id.idiag_sport,
43 req->id.idiag_dst[0], req->id.idiag_dport,
44 req->id.idiag_if, 0, tbl, NULL);
45#if IS_ENABLED(CONFIG_IPV6)
46 else if (req->sdiag_family == AF_INET6)
47 sk = __udp6_lib_lookup(net,
48 (struct in6_addr *)req->id.idiag_src,
49 req->id.idiag_sport,
50 (struct in6_addr *)req->id.idiag_dst,
51 req->id.idiag_dport,
52 req->id.idiag_if, 0, tbl, NULL);
53#endif
54 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
55 sk = NULL;
56 rcu_read_unlock();
57 err = -ENOENT;
58 if (!sk)
59 goto out_nosk;
60
61 err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
62 if (err)
63 goto out;
64
65 err = -ENOMEM;
66 rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
67 inet_diag_msg_attrs_size() +
68 nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,
69 GFP_KERNEL);
70 if (!rep)
71 goto out;
72
73 err = inet_sk_diag_fill(sk, NULL, rep, cb, req, 0,
74 netlink_net_capable(in_skb, CAP_NET_ADMIN));
75 if (err < 0) {
76 WARN_ON(err == -EMSGSIZE);
77 kfree_skb(rep);
78 goto out;
79 }
80 err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
81
82out:
83 if (sk)
84 sock_put(sk);
85out_nosk:
86 return err;
87}
88
89static void udp_dump(struct udp_table *table, struct sk_buff *skb,
90 struct netlink_callback *cb,
91 const struct inet_diag_req_v2 *r)
92{
93 bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
94 struct net *net = sock_net(skb->sk);
95 int num, s_num, slot, s_slot;
96
97 s_slot = cb->args[0];
98 num = s_num = cb->args[1];
99
100 for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
101 struct udp_hslot *hslot = &table->hash[slot];
102 struct sock *sk;
103
104 num = 0;
105
106 if (hlist_empty(&hslot->head))
107 continue;
108
109 spin_lock_bh(&hslot->lock);
110 sk_for_each(sk, &hslot->head) {
111 struct inet_sock *inet = inet_sk(sk);
112
113 if (!net_eq(sock_net(sk), net))
114 continue;
115 if (num < s_num)
116 goto next;
117 if (!(r->idiag_states & (1 << sk->sk_state)))
118 goto next;
119 if (r->sdiag_family != AF_UNSPEC &&
120 sk->sk_family != r->sdiag_family)
121 goto next;
122 if (r->id.idiag_sport != inet->inet_sport &&
123 r->id.idiag_sport)
124 goto next;
125 if (r->id.idiag_dport != inet->inet_dport &&
126 r->id.idiag_dport)
127 goto next;
128
129 if (sk_diag_dump(sk, skb, cb, r, net_admin) < 0) {
130 spin_unlock_bh(&hslot->lock);
131 goto done;
132 }
133next:
134 num++;
135 }
136 spin_unlock_bh(&hslot->lock);
137 }
138done:
139 cb->args[0] = slot;
140 cb->args[1] = num;
141}
142
143static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
144 const struct inet_diag_req_v2 *r)
145{
146 udp_dump(sock_net(cb->skb->sk)->ipv4.udp_table, skb, cb, r);
147}
148
149static int udp_diag_dump_one(struct netlink_callback *cb,
150 const struct inet_diag_req_v2 *req)
151{
152 return udp_dump_one(sock_net(cb->skb->sk)->ipv4.udp_table, cb, req);
153}
154
155static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
156 void *info)
157{
158 r->idiag_rqueue = udp_rqueue_get(sk);
159 r->idiag_wqueue = sk_wmem_alloc_get(sk);
160}
161
162#ifdef CONFIG_INET_DIAG_DESTROY
163static int __udp_diag_destroy(struct sk_buff *in_skb,
164 const struct inet_diag_req_v2 *req,
165 struct udp_table *tbl)
166{
167 struct net *net = sock_net(in_skb->sk);
168 struct sock *sk;
169 int err;
170
171 rcu_read_lock();
172
173 if (req->sdiag_family == AF_INET)
174 sk = __udp4_lib_lookup(net,
175 req->id.idiag_dst[0], req->id.idiag_dport,
176 req->id.idiag_src[0], req->id.idiag_sport,
177 req->id.idiag_if, 0, tbl, NULL);
178#if IS_ENABLED(CONFIG_IPV6)
179 else if (req->sdiag_family == AF_INET6) {
180 if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
181 ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
182 sk = __udp4_lib_lookup(net,
183 req->id.idiag_dst[3], req->id.idiag_dport,
184 req->id.idiag_src[3], req->id.idiag_sport,
185 req->id.idiag_if, 0, tbl, NULL);
186
187 else
188 sk = __udp6_lib_lookup(net,
189 (struct in6_addr *)req->id.idiag_dst,
190 req->id.idiag_dport,
191 (struct in6_addr *)req->id.idiag_src,
192 req->id.idiag_sport,
193 req->id.idiag_if, 0, tbl, NULL);
194 }
195#endif
196 else {
197 rcu_read_unlock();
198 return -EINVAL;
199 }
200
201 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
202 sk = NULL;
203
204 rcu_read_unlock();
205
206 if (!sk)
207 return -ENOENT;
208
209 if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
210 sock_put(sk);
211 return -ENOENT;
212 }
213
214 err = sock_diag_destroy(sk, ECONNABORTED);
215
216 sock_put(sk);
217
218 return err;
219}
220
221static int udp_diag_destroy(struct sk_buff *in_skb,
222 const struct inet_diag_req_v2 *req)
223{
224 return __udp_diag_destroy(in_skb, req, sock_net(in_skb->sk)->ipv4.udp_table);
225}
226
227static int udplite_diag_destroy(struct sk_buff *in_skb,
228 const struct inet_diag_req_v2 *req)
229{
230 return __udp_diag_destroy(in_skb, req, &udplite_table);
231}
232
233#endif
234
235static const struct inet_diag_handler udp_diag_handler = {
236 .owner = THIS_MODULE,
237 .dump = udp_diag_dump,
238 .dump_one = udp_diag_dump_one,
239 .idiag_get_info = udp_diag_get_info,
240 .idiag_type = IPPROTO_UDP,
241 .idiag_info_size = 0,
242#ifdef CONFIG_INET_DIAG_DESTROY
243 .destroy = udp_diag_destroy,
244#endif
245};
246
247static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
248 const struct inet_diag_req_v2 *r)
249{
250 udp_dump(&udplite_table, skb, cb, r);
251}
252
253static int udplite_diag_dump_one(struct netlink_callback *cb,
254 const struct inet_diag_req_v2 *req)
255{
256 return udp_dump_one(&udplite_table, cb, req);
257}
258
259static const struct inet_diag_handler udplite_diag_handler = {
260 .owner = THIS_MODULE,
261 .dump = udplite_diag_dump,
262 .dump_one = udplite_diag_dump_one,
263 .idiag_get_info = udp_diag_get_info,
264 .idiag_type = IPPROTO_UDPLITE,
265 .idiag_info_size = 0,
266#ifdef CONFIG_INET_DIAG_DESTROY
267 .destroy = udplite_diag_destroy,
268#endif
269};
270
271static int __init udp_diag_init(void)
272{
273 int err;
274
275 err = inet_diag_register(&udp_diag_handler);
276 if (err)
277 goto out;
278 err = inet_diag_register(&udplite_diag_handler);
279 if (err)
280 goto out_lite;
281out:
282 return err;
283out_lite:
284 inet_diag_unregister(&udp_diag_handler);
285 goto out;
286}
287
288static void __exit udp_diag_exit(void)
289{
290 inet_diag_unregister(&udplite_diag_handler);
291 inet_diag_unregister(&udp_diag_handler);
292}
293
294module_init(udp_diag_init);
295module_exit(udp_diag_exit);
296MODULE_LICENSE("GPL");
297MODULE_DESCRIPTION("UDP socket monitoring via SOCK_DIAG");
298MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
299MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);