xref: /openbmc/linux/net/ipv4/udp_diag.c (revision 82e6fdd6)
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 
20 static 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, bool net_admin)
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, net_admin);
32 }
33 
34 static 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 = NULL;
40 	struct sk_buff *rep;
41 	struct net *net = sock_net(in_skb->sk);
42 
43 	rcu_read_lock();
44 	if (req->sdiag_family == AF_INET)
45 		sk = __udp4_lib_lookup(net,
46 				req->id.idiag_src[0], req->id.idiag_sport,
47 				req->id.idiag_dst[0], req->id.idiag_dport,
48 				req->id.idiag_if, 0, tbl, NULL);
49 #if IS_ENABLED(CONFIG_IPV6)
50 	else if (req->sdiag_family == AF_INET6)
51 		sk = __udp6_lib_lookup(net,
52 				(struct in6_addr *)req->id.idiag_src,
53 				req->id.idiag_sport,
54 				(struct in6_addr *)req->id.idiag_dst,
55 				req->id.idiag_dport,
56 				req->id.idiag_if, 0, tbl, NULL);
57 #endif
58 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
59 		sk = NULL;
60 	rcu_read_unlock();
61 	err = -ENOENT;
62 	if (!sk)
63 		goto out_nosk;
64 
65 	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
66 	if (err)
67 		goto out;
68 
69 	err = -ENOMEM;
70 	rep = nlmsg_new(sizeof(struct inet_diag_msg) +
71 			sizeof(struct inet_diag_meminfo) + 64,
72 			GFP_KERNEL);
73 	if (!rep)
74 		goto out;
75 
76 	err = inet_sk_diag_fill(sk, NULL, rep, req,
77 			   sk_user_ns(NETLINK_CB(in_skb).sk),
78 			   NETLINK_CB(in_skb).portid,
79 			   nlh->nlmsg_seq, 0, nlh,
80 			   netlink_net_capable(in_skb, CAP_NET_ADMIN));
81 	if (err < 0) {
82 		WARN_ON(err == -EMSGSIZE);
83 		kfree_skb(rep);
84 		goto out;
85 	}
86 	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
87 			      MSG_DONTWAIT);
88 	if (err > 0)
89 		err = 0;
90 out:
91 	if (sk)
92 		sock_put(sk);
93 out_nosk:
94 	return err;
95 }
96 
97 static void udp_dump(struct udp_table *table, struct sk_buff *skb,
98 		     struct netlink_callback *cb,
99 		     const struct inet_diag_req_v2 *r, struct nlattr *bc)
100 {
101 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
102 	struct net *net = sock_net(skb->sk);
103 	int num, s_num, slot, s_slot;
104 
105 	s_slot = cb->args[0];
106 	num = s_num = cb->args[1];
107 
108 	for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
109 		struct udp_hslot *hslot = &table->hash[slot];
110 		struct sock *sk;
111 
112 		num = 0;
113 
114 		if (hlist_empty(&hslot->head))
115 			continue;
116 
117 		spin_lock_bh(&hslot->lock);
118 		sk_for_each(sk, &hslot->head) {
119 			struct inet_sock *inet = inet_sk(sk);
120 
121 			if (!net_eq(sock_net(sk), net))
122 				continue;
123 			if (num < s_num)
124 				goto next;
125 			if (!(r->idiag_states & (1 << sk->sk_state)))
126 				goto next;
127 			if (r->sdiag_family != AF_UNSPEC &&
128 					sk->sk_family != r->sdiag_family)
129 				goto next;
130 			if (r->id.idiag_sport != inet->inet_sport &&
131 			    r->id.idiag_sport)
132 				goto next;
133 			if (r->id.idiag_dport != inet->inet_dport &&
134 			    r->id.idiag_dport)
135 				goto next;
136 
137 			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) {
138 				spin_unlock_bh(&hslot->lock);
139 				goto done;
140 			}
141 next:
142 			num++;
143 		}
144 		spin_unlock_bh(&hslot->lock);
145 	}
146 done:
147 	cb->args[0] = slot;
148 	cb->args[1] = num;
149 }
150 
151 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
152 			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
153 {
154 	udp_dump(&udp_table, skb, cb, r, bc);
155 }
156 
157 static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
158 			     const struct inet_diag_req_v2 *req)
159 {
160 	return udp_dump_one(&udp_table, in_skb, nlh, req);
161 }
162 
163 static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
164 		void *info)
165 {
166 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
167 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
168 }
169 
170 #ifdef CONFIG_INET_DIAG_DESTROY
171 static int __udp_diag_destroy(struct sk_buff *in_skb,
172 			      const struct inet_diag_req_v2 *req,
173 			      struct udp_table *tbl)
174 {
175 	struct net *net = sock_net(in_skb->sk);
176 	struct sock *sk;
177 	int err;
178 
179 	rcu_read_lock();
180 
181 	if (req->sdiag_family == AF_INET)
182 		sk = __udp4_lib_lookup(net,
183 				req->id.idiag_dst[0], req->id.idiag_dport,
184 				req->id.idiag_src[0], req->id.idiag_sport,
185 				req->id.idiag_if, 0, tbl, NULL);
186 #if IS_ENABLED(CONFIG_IPV6)
187 	else if (req->sdiag_family == AF_INET6) {
188 		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
189 		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
190 			sk = __udp4_lib_lookup(net,
191 					req->id.idiag_dst[3], req->id.idiag_dport,
192 					req->id.idiag_src[3], req->id.idiag_sport,
193 					req->id.idiag_if, 0, tbl, NULL);
194 
195 		else
196 			sk = __udp6_lib_lookup(net,
197 					(struct in6_addr *)req->id.idiag_dst,
198 					req->id.idiag_dport,
199 					(struct in6_addr *)req->id.idiag_src,
200 					req->id.idiag_sport,
201 					req->id.idiag_if, 0, tbl, NULL);
202 	}
203 #endif
204 	else {
205 		rcu_read_unlock();
206 		return -EINVAL;
207 	}
208 
209 	if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
210 		sk = NULL;
211 
212 	rcu_read_unlock();
213 
214 	if (!sk)
215 		return -ENOENT;
216 
217 	if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
218 		sock_put(sk);
219 		return -ENOENT;
220 	}
221 
222 	err = sock_diag_destroy(sk, ECONNABORTED);
223 
224 	sock_put(sk);
225 
226 	return err;
227 }
228 
229 static int udp_diag_destroy(struct sk_buff *in_skb,
230 			    const struct inet_diag_req_v2 *req)
231 {
232 	return __udp_diag_destroy(in_skb, req, &udp_table);
233 }
234 
235 static int udplite_diag_destroy(struct sk_buff *in_skb,
236 				const struct inet_diag_req_v2 *req)
237 {
238 	return __udp_diag_destroy(in_skb, req, &udplite_table);
239 }
240 
241 #endif
242 
243 static const struct inet_diag_handler udp_diag_handler = {
244 	.dump		 = udp_diag_dump,
245 	.dump_one	 = udp_diag_dump_one,
246 	.idiag_get_info  = udp_diag_get_info,
247 	.idiag_type	 = IPPROTO_UDP,
248 	.idiag_info_size = 0,
249 #ifdef CONFIG_INET_DIAG_DESTROY
250 	.destroy	 = udp_diag_destroy,
251 #endif
252 };
253 
254 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
255 			      const struct inet_diag_req_v2 *r,
256 			      struct nlattr *bc)
257 {
258 	udp_dump(&udplite_table, skb, cb, r, bc);
259 }
260 
261 static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
262 				 const struct inet_diag_req_v2 *req)
263 {
264 	return udp_dump_one(&udplite_table, in_skb, nlh, req);
265 }
266 
267 static const struct inet_diag_handler udplite_diag_handler = {
268 	.dump		 = udplite_diag_dump,
269 	.dump_one	 = udplite_diag_dump_one,
270 	.idiag_get_info  = udp_diag_get_info,
271 	.idiag_type	 = IPPROTO_UDPLITE,
272 	.idiag_info_size = 0,
273 #ifdef CONFIG_INET_DIAG_DESTROY
274 	.destroy	 = udplite_diag_destroy,
275 #endif
276 };
277 
278 static int __init udp_diag_init(void)
279 {
280 	int err;
281 
282 	err = inet_diag_register(&udp_diag_handler);
283 	if (err)
284 		goto out;
285 	err = inet_diag_register(&udplite_diag_handler);
286 	if (err)
287 		goto out_lite;
288 out:
289 	return err;
290 out_lite:
291 	inet_diag_unregister(&udp_diag_handler);
292 	goto out;
293 }
294 
295 static void __exit udp_diag_exit(void)
296 {
297 	inet_diag_unregister(&udplite_diag_handler);
298 	inet_diag_unregister(&udp_diag_handler);
299 }
300 
301 module_init(udp_diag_init);
302 module_exit(udp_diag_exit);
303 MODULE_LICENSE("GPL");
304 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
305 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
306