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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 #include <net/ipv6.h>
20 
sk_diag_dump(struct sock * sk,struct sk_buff * skb,struct netlink_callback * cb,struct inet_diag_req_v2 * req,struct nlattr * bc,bool net_admin)21 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
22 		struct netlink_callback *cb, 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 
udp_dump_one(struct udp_table * tbl,struct sk_buff * in_skb,const struct nlmsghdr * nlh,struct inet_diag_req_v2 * req)34 static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
35 		const struct nlmsghdr *nlh, struct inet_diag_req_v2 *req)
36 {
37 	int err = -EINVAL;
38 	struct sock *sk;
39 	struct sk_buff *rep;
40 	struct net *net = sock_net(in_skb->sk);
41 
42 	if (req->sdiag_family == AF_INET)
43 		sk = __udp4_lib_lookup(net,
44 				req->id.idiag_src[0], req->id.idiag_sport,
45 				req->id.idiag_dst[0], req->id.idiag_dport,
46 				req->id.idiag_if, tbl);
47 #if IS_ENABLED(CONFIG_IPV6)
48 	else if (req->sdiag_family == AF_INET6)
49 		sk = __udp6_lib_lookup(net,
50 				(struct in6_addr *)req->id.idiag_src,
51 				req->id.idiag_sport,
52 				(struct in6_addr *)req->id.idiag_dst,
53 				req->id.idiag_dport,
54 				req->id.idiag_if, tbl);
55 #endif
56 	else
57 		goto out_nosk;
58 
59 	err = -ENOENT;
60 	if (sk == NULL)
61 		goto out_nosk;
62 
63 	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
64 	if (err)
65 		goto out;
66 
67 	err = -ENOMEM;
68 	rep = nlmsg_new(sizeof(struct inet_diag_msg) +
69 			sizeof(struct inet_diag_meminfo) + 64,
70 			GFP_KERNEL);
71 	if (!rep)
72 		goto out;
73 
74 	err = inet_sk_diag_fill(sk, NULL, rep, req,
75 			   sk_user_ns(NETLINK_CB(in_skb).sk),
76 			   NETLINK_CB(in_skb).portid,
77 			   nlh->nlmsg_seq, 0, nlh,
78 			   ns_capable(net->user_ns, CAP_NET_ADMIN));
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;
88 out:
89 	if (sk)
90 		sock_put(sk);
91 out_nosk:
92 	return err;
93 }
94 
udp_dump(struct udp_table * table,struct sk_buff * skb,struct netlink_callback * cb,struct inet_diag_req_v2 * r,struct nlattr * bc)95 static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlink_callback *cb,
96 		struct inet_diag_req_v2 *r, struct nlattr *bc)
97 {
98 	int num, s_num, slot, s_slot;
99 	struct net *net = sock_net(skb->sk);
100 	bool net_admin = ns_capable(net->user_ns, CAP_NET_ADMIN);
101 
102 	s_slot = cb->args[0];
103 	num = s_num = cb->args[1];
104 
105 	for (slot = s_slot; slot <= table->mask; num = s_num = 0, slot++) {
106 		struct sock *sk;
107 		struct hlist_nulls_node *node;
108 		struct udp_hslot *hslot = &table->hash[slot];
109 
110 		if (hlist_nulls_empty(&hslot->head))
111 			continue;
112 
113 		spin_lock_bh(&hslot->lock);
114 		sk_nulls_for_each(sk, node, &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 			}
137 next:
138 			num++;
139 		}
140 		spin_unlock_bh(&hslot->lock);
141 	}
142 done:
143 	cb->args[0] = slot;
144 	cb->args[1] = num;
145 }
146 
udp_diag_dump(struct sk_buff * skb,struct netlink_callback * cb,struct inet_diag_req_v2 * r,struct nlattr * bc)147 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
148 		struct inet_diag_req_v2 *r, struct nlattr *bc)
149 {
150 	udp_dump(&udp_table, skb, cb, r, bc);
151 }
152 
udp_diag_dump_one(struct sk_buff * in_skb,const struct nlmsghdr * nlh,struct inet_diag_req_v2 * req)153 static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
154 		struct inet_diag_req_v2 *req)
155 {
156 	return udp_dump_one(&udp_table, in_skb, nlh, req);
157 }
158 
udp_diag_get_info(struct sock * sk,struct inet_diag_msg * r,void * info)159 static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
160 		void *info)
161 {
162 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
163 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
164 }
165 
166 #ifdef CONFIG_INET_DIAG_DESTROY
__udp_diag_destroy(struct sk_buff * in_skb,const struct inet_diag_req_v2 * req,struct udp_table * tbl)167 static 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, tbl);
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, tbl);
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, tbl);
198 	}
199 #endif
200 	else {
201 		rcu_read_unlock();
202 		return -EINVAL;
203 	}
204 
205 	if (sk && !atomic_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, (__u32 *) 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 
udp_diag_destroy(struct sk_buff * in_skb,struct inet_diag_req_v2 * req)225 static int udp_diag_destroy(struct sk_buff *in_skb,
226 			    struct inet_diag_req_v2 *req)
227 {
228 	return __udp_diag_destroy(in_skb, req, &udp_table);
229 }
230 
udplite_diag_destroy(struct sk_buff * in_skb,struct inet_diag_req_v2 * req)231 static int udplite_diag_destroy(struct sk_buff *in_skb,
232 				struct inet_diag_req_v2 *req)
233 {
234 	return __udp_diag_destroy(in_skb, req, &udplite_table);
235 }
236 
237 #endif
238 
239 static const struct inet_diag_handler udp_diag_handler = {
240 	.dump		 = udp_diag_dump,
241 	.dump_one	 = udp_diag_dump_one,
242 	.idiag_get_info  = udp_diag_get_info,
243 	.idiag_type	 = IPPROTO_UDP,
244 #ifdef CONFIG_INET_DIAG_DESTROY
245 	.destroy	 = udp_diag_destroy,
246 #endif
247 };
248 
udplite_diag_dump(struct sk_buff * skb,struct netlink_callback * cb,struct inet_diag_req_v2 * r,struct nlattr * bc)249 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
250 		struct inet_diag_req_v2 *r, struct nlattr *bc)
251 {
252 	udp_dump(&udplite_table, skb, cb, r, bc);
253 }
254 
udplite_diag_dump_one(struct sk_buff * in_skb,const struct nlmsghdr * nlh,struct inet_diag_req_v2 * req)255 static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
256 		struct inet_diag_req_v2 *req)
257 {
258 	return udp_dump_one(&udplite_table, in_skb, nlh, req);
259 }
260 
261 static const struct inet_diag_handler udplite_diag_handler = {
262 	.dump		 = udplite_diag_dump,
263 	.dump_one	 = udplite_diag_dump_one,
264 	.idiag_get_info  = udp_diag_get_info,
265 	.idiag_type	 = IPPROTO_UDPLITE,
266 #ifdef CONFIG_INET_DIAG_DESTROY
267 	.destroy	 = udplite_diag_destroy,
268 #endif
269 };
270 
udp_diag_init(void)271 static 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;
281 out:
282 	return err;
283 out_lite:
284 	inet_diag_unregister(&udp_diag_handler);
285 	goto out;
286 }
287 
udp_diag_exit(void)288 static void __exit udp_diag_exit(void)
289 {
290 	inet_diag_unregister(&udplite_diag_handler);
291 	inet_diag_unregister(&udp_diag_handler);
292 }
293 
294 module_init(udp_diag_init);
295 module_exit(udp_diag_exit);
296 MODULE_LICENSE("GPL");
297 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
298 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
299