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
16 static 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
28 static 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
82 out:
83 if (sk)
84 sock_put(sk);
85 out_nosk:
86 return err;
87 }
88
89 static 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 }
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
147 static 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
153 static 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
159 static 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
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, 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
225 static 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
231 static 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
239 static 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
251 static 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
257 static 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
263 static 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
275 static 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;
285 out:
286 return err;
287 out_lite:
288 inet_diag_unregister(&udp_diag_handler);
289 goto out;
290 }
291
292 static void __exit udp_diag_exit(void)
293 {
294 inet_diag_unregister(&udplite_diag_handler);
295 inet_diag_unregister(&udp_diag_handler);
296 }
297
298 module_init(udp_diag_init);
299 module_exit(udp_diag_exit);
300 MODULE_LICENSE("GPL");
301 MODULE_DESCRIPTION("UDP socket monitoring via SOCK_DIAG");
302 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
303 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
304
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