1/*
2 * udp_diag.c	Module for monitoring UDP transport protocols sockets.
3 *
4 * Authors:	Pavel Emelyanov, <xemul@parallels.com>
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
13#include <linux/module.h>
14#include <linux/inet_diag.h>
15#include <linux/udp.h>
16#include <net/udp.h>
17#include <net/udplite.h>
18#include <linux/sock_diag.h>
19
20static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
21			struct netlink_callback *cb,
22			const struct inet_diag_req_v2 *req,
23			struct nlattr *bc)
24{
25	if (!inet_diag_bc_sk(bc, sk))
26		return 0;
27
28	return inet_sk_diag_fill(sk, NULL, skb, req,
29			sk_user_ns(NETLINK_CB(cb->skb).sk),
30			NETLINK_CB(cb->skb).portid,
31			cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
32}
33
34static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
35			const struct nlmsghdr *nlh,
36			const struct inet_diag_req_v2 *req)
37{
38	int err = -EINVAL;
39	struct sock *sk;
40	struct sk_buff *rep;
41	struct net *net = sock_net(in_skb->sk);
42
43	if (req->sdiag_family == AF_INET)
44		sk = __udp4_lib_lookup(net,
45				req->id.idiag_src[0], req->id.idiag_sport,
46				req->id.idiag_dst[0], req->id.idiag_dport,
47				req->id.idiag_if, tbl);
48#if IS_ENABLED(CONFIG_IPV6)
49	else if (req->sdiag_family == AF_INET6)
50		sk = __udp6_lib_lookup(net,
51				(struct in6_addr *)req->id.idiag_src,
52				req->id.idiag_sport,
53				(struct in6_addr *)req->id.idiag_dst,
54				req->id.idiag_dport,
55				req->id.idiag_if, tbl);
56#endif
57	else
58		goto out_nosk;
59
60	err = -ENOENT;
61	if (!sk)
62		goto out_nosk;
63
64	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
65	if (err)
66		goto out;
67
68	err = -ENOMEM;
69	rep = nlmsg_new(sizeof(struct inet_diag_msg) +
70			sizeof(struct inet_diag_meminfo) + 64,
71			GFP_KERNEL);
72	if (!rep)
73		goto out;
74
75	err = inet_sk_diag_fill(sk, NULL, rep, req,
76			   sk_user_ns(NETLINK_CB(in_skb).sk),
77			   NETLINK_CB(in_skb).portid,
78			   nlh->nlmsg_seq, 0, nlh);
79	if (err < 0) {
80		WARN_ON(err == -EMSGSIZE);
81		kfree_skb(rep);
82		goto out;
83	}
84	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
85			      MSG_DONTWAIT);
86	if (err > 0)
87		err = 0;
88out:
89	if (sk)
90		sock_put(sk);
91out_nosk:
92	return err;
93}
94
95static void udp_dump(struct udp_table *table, struct sk_buff *skb,
96		     struct netlink_callback *cb,
97		     const struct inet_diag_req_v2 *r, struct nlattr *bc)
98{
99	int num, s_num, slot, s_slot;
100	struct net *net = sock_net(skb->sk);
101
102	s_slot = cb->args[0];
103	num = s_num = cb->args[1];
104
105	for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
106		struct sock *sk;
107		struct hlist_nulls_node *node;
108		struct udp_hslot *hslot = &table->hash[slot];
109
110		num = 0;
111
112		if (hlist_nulls_empty(&hslot->head))
113			continue;
114
115		spin_lock_bh(&hslot->lock);
116		sk_nulls_for_each(sk, node, &hslot->head) {
117			struct inet_sock *inet = inet_sk(sk);
118
119			if (!net_eq(sock_net(sk), net))
120				continue;
121			if (num < s_num)
122				goto next;
123			if (!(r->idiag_states & (1 << sk->sk_state)))
124				goto next;
125			if (r->sdiag_family != AF_UNSPEC &&
126					sk->sk_family != r->sdiag_family)
127				goto next;
128			if (r->id.idiag_sport != inet->inet_sport &&
129			    r->id.idiag_sport)
130				goto next;
131			if (r->id.idiag_dport != inet->inet_dport &&
132			    r->id.idiag_dport)
133				goto next;
134
135			if (sk_diag_dump(sk, skb, cb, r, bc) < 0) {
136				spin_unlock_bh(&hslot->lock);
137				goto done;
138			}
139next:
140			num++;
141		}
142		spin_unlock_bh(&hslot->lock);
143	}
144done:
145	cb->args[0] = slot;
146	cb->args[1] = num;
147}
148
149static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
150			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
151{
152	udp_dump(&udp_table, skb, cb, r, bc);
153}
154
155static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
156			     const struct inet_diag_req_v2 *req)
157{
158	return udp_dump_one(&udp_table, in_skb, nlh, req);
159}
160
161static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
162		void *info)
163{
164	r->idiag_rqueue = sk_rmem_alloc_get(sk);
165	r->idiag_wqueue = sk_wmem_alloc_get(sk);
166}
167
168static const struct inet_diag_handler udp_diag_handler = {
169	.dump		 = udp_diag_dump,
170	.dump_one	 = udp_diag_dump_one,
171	.idiag_get_info  = udp_diag_get_info,
172	.idiag_type	 = IPPROTO_UDP,
173	.idiag_info_size = 0,
174};
175
176static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
177			      const struct inet_diag_req_v2 *r,
178			      struct nlattr *bc)
179{
180	udp_dump(&udplite_table, skb, cb, r, bc);
181}
182
183static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
184				 const struct inet_diag_req_v2 *req)
185{
186	return udp_dump_one(&udplite_table, in_skb, nlh, req);
187}
188
189static const struct inet_diag_handler udplite_diag_handler = {
190	.dump		 = udplite_diag_dump,
191	.dump_one	 = udplite_diag_dump_one,
192	.idiag_get_info  = udp_diag_get_info,
193	.idiag_type	 = IPPROTO_UDPLITE,
194	.idiag_info_size = 0,
195};
196
197static int __init udp_diag_init(void)
198{
199	int err;
200
201	err = inet_diag_register(&udp_diag_handler);
202	if (err)
203		goto out;
204	err = inet_diag_register(&udplite_diag_handler);
205	if (err)
206		goto out_lite;
207out:
208	return err;
209out_lite:
210	inet_diag_unregister(&udp_diag_handler);
211	goto out;
212}
213
214static void __exit udp_diag_exit(void)
215{
216	inet_diag_unregister(&udplite_diag_handler);
217	inet_diag_unregister(&udp_diag_handler);
218}
219
220module_init(udp_diag_init);
221module_exit(udp_diag_exit);
222MODULE_LICENSE("GPL");
223MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
224MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
225