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			struct nlattr *bc, bool net_admin)
20{
21	if (!inet_diag_bc_sk(bc, 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	struct inet_diag_dump_data *cb_data;
96	int num, s_num, slot, s_slot;
97	struct nlattr *bc;
98
99	cb_data = cb->data;
100	bc = cb_data->inet_diag_nla_bc;
101	s_slot = cb->args[0];
102	num = s_num = cb->args[1];
103
104	for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
105		struct udp_hslot *hslot = &table->hash[slot];
106		struct sock *sk;
107
108		num = 0;
109
110		if (hlist_empty(&hslot->head))
111			continue;
112
113		spin_lock_bh(&hslot->lock);
114		sk_for_each(sk, &hslot->head) {
115			struct inet_sock *inet = inet_sk(sk);
116
117			if (!net_eq(sock_net(sk), net))
118				continue;
119			if (num < s_num)
120				goto next;
121			if (!(r->idiag_states & (1 << sk->sk_state)))
122				goto next;
123			if (r->sdiag_family != AF_UNSPEC &&
124					sk->sk_family != r->sdiag_family)
125				goto next;
126			if (r->id.idiag_sport != inet->inet_sport &&
127			    r->id.idiag_sport)
128				goto next;
129			if (r->id.idiag_dport != inet->inet_dport &&
130			    r->id.idiag_dport)
131				goto next;
132
133			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) {
134				spin_unlock_bh(&hslot->lock);
135				goto done;
136			}
137next:
138			num++;
139		}
140		spin_unlock_bh(&hslot->lock);
141	}
142done:
143	cb->args[0] = slot;
144	cb->args[1] = num;
145}
146
147static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
148			  const struct inet_diag_req_v2 *r)
149{
150	udp_dump(sock_net(cb->skb->sk)->ipv4.udp_table, skb, cb, r);
151}
152
153static int udp_diag_dump_one(struct netlink_callback *cb,
154			     const struct inet_diag_req_v2 *req)
155{
156	return udp_dump_one(sock_net(cb->skb->sk)->ipv4.udp_table, cb, req);
157}
158
159static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
160		void *info)
161{
162	r->idiag_rqueue = udp_rqueue_get(sk);
163	r->idiag_wqueue = sk_wmem_alloc_get(sk);
164}
165
166#ifdef CONFIG_INET_DIAG_DESTROY
167static int __udp_diag_destroy(struct sk_buff *in_skb,
168			      const struct inet_diag_req_v2 *req,
169			      struct udp_table *tbl)
170{
171	struct net *net = sock_net(in_skb->sk);
172	struct sock *sk;
173	int err;
174
175	rcu_read_lock();
176
177	if (req->sdiag_family == AF_INET)
178		sk = __udp4_lib_lookup(net,
179				req->id.idiag_dst[0], req->id.idiag_dport,
180				req->id.idiag_src[0], req->id.idiag_sport,
181				req->id.idiag_if, 0, tbl, NULL);
182#if IS_ENABLED(CONFIG_IPV6)
183	else if (req->sdiag_family == AF_INET6) {
184		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
185		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
186			sk = __udp4_lib_lookup(net,
187					req->id.idiag_dst[3], req->id.idiag_dport,
188					req->id.idiag_src[3], req->id.idiag_sport,
189					req->id.idiag_if, 0, tbl, NULL);
190
191		else
192			sk = __udp6_lib_lookup(net,
193					(struct in6_addr *)req->id.idiag_dst,
194					req->id.idiag_dport,
195					(struct in6_addr *)req->id.idiag_src,
196					req->id.idiag_sport,
197					req->id.idiag_if, 0, tbl, NULL);
198	}
199#endif
200	else {
201		rcu_read_unlock();
202		return -EINVAL;
203	}
204
205	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
206		sk = NULL;
207
208	rcu_read_unlock();
209
210	if (!sk)
211		return -ENOENT;
212
213	if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
214		sock_put(sk);
215		return -ENOENT;
216	}
217
218	err = sock_diag_destroy(sk, ECONNABORTED);
219
220	sock_put(sk);
221
222	return err;
223}
224
225static int udp_diag_destroy(struct sk_buff *in_skb,
226			    const struct inet_diag_req_v2 *req)
227{
228	return __udp_diag_destroy(in_skb, req, sock_net(in_skb->sk)->ipv4.udp_table);
229}
230
231static int udplite_diag_destroy(struct sk_buff *in_skb,
232				const struct inet_diag_req_v2 *req)
233{
234	return __udp_diag_destroy(in_skb, req, &udplite_table);
235}
236
237#endif
238
239static const struct inet_diag_handler udp_diag_handler = {
240	.owner		 = THIS_MODULE,
241	.dump		 = udp_diag_dump,
242	.dump_one	 = udp_diag_dump_one,
243	.idiag_get_info  = udp_diag_get_info,
244	.idiag_type	 = IPPROTO_UDP,
245	.idiag_info_size = 0,
246#ifdef CONFIG_INET_DIAG_DESTROY
247	.destroy	 = udp_diag_destroy,
248#endif
249};
250
251static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
252			      const struct inet_diag_req_v2 *r)
253{
254	udp_dump(&udplite_table, skb, cb, r);
255}
256
257static int udplite_diag_dump_one(struct netlink_callback *cb,
258				 const struct inet_diag_req_v2 *req)
259{
260	return udp_dump_one(&udplite_table, cb, req);
261}
262
263static const struct inet_diag_handler udplite_diag_handler = {
264	.owner		 = THIS_MODULE,
265	.dump		 = udplite_diag_dump,
266	.dump_one	 = udplite_diag_dump_one,
267	.idiag_get_info  = udp_diag_get_info,
268	.idiag_type	 = IPPROTO_UDPLITE,
269	.idiag_info_size = 0,
270#ifdef CONFIG_INET_DIAG_DESTROY
271	.destroy	 = udplite_diag_destroy,
272#endif
273};
274
275static int __init udp_diag_init(void)
276{
277	int err;
278
279	err = inet_diag_register(&udp_diag_handler);
280	if (err)
281		goto out;
282	err = inet_diag_register(&udplite_diag_handler);
283	if (err)
284		goto out_lite;
285out:
286	return err;
287out_lite:
288	inet_diag_unregister(&udp_diag_handler);
289	goto out;
290}
291
292static void __exit udp_diag_exit(void)
293{
294	inet_diag_unregister(&udplite_diag_handler);
295	inet_diag_unregister(&udp_diag_handler);
296}
297
298module_init(udp_diag_init);
299module_exit(udp_diag_exit);
300MODULE_LICENSE("GPL");
301MODULE_DESCRIPTION("UDP socket monitoring via SOCK_DIAG");
302MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
303MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
304