xref: /linux/net/ipv4/udp_diag.c (revision 9e8ba5f3ec35cba4fd8a8bebda548c4db2651e40)
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/inet_diag.h>
19 #include <linux/sock_diag.h>
20 
21 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
22 		struct netlink_callback *cb, struct inet_diag_req *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, NETLINK_CB(cb->skb).pid,
29 			cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
30 }
31 
32 static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
33 		const struct nlmsghdr *nlh, struct inet_diag_req *req)
34 {
35 	int err = -EINVAL;
36 	struct sock *sk;
37 	struct sk_buff *rep;
38 
39 	if (req->sdiag_family == AF_INET)
40 		sk = __udp4_lib_lookup(&init_net,
41 				req->id.idiag_src[0], req->id.idiag_sport,
42 				req->id.idiag_dst[0], req->id.idiag_dport,
43 				req->id.idiag_if, tbl);
44 #if IS_ENABLED(CONFIG_IPV6)
45 	else if (req->sdiag_family == AF_INET6)
46 		sk = __udp6_lib_lookup(&init_net,
47 				(struct in6_addr *)req->id.idiag_src,
48 				req->id.idiag_sport,
49 				(struct in6_addr *)req->id.idiag_dst,
50 				req->id.idiag_dport,
51 				req->id.idiag_if, tbl);
52 #endif
53 	else
54 		goto out_nosk;
55 
56 	err = -ENOENT;
57 	if (sk == NULL)
58 		goto out_nosk;
59 
60 	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
61 	if (err)
62 		goto out;
63 
64 	err = -ENOMEM;
65 	rep = alloc_skb(NLMSG_SPACE((sizeof(struct inet_diag_msg) +
66 				     sizeof(struct inet_diag_meminfo) +
67 				     64)), GFP_KERNEL);
68 	if (!rep)
69 		goto out;
70 
71 	err = inet_sk_diag_fill(sk, NULL, rep, req,
72 			   NETLINK_CB(in_skb).pid,
73 			   nlh->nlmsg_seq, 0, nlh);
74 	if (err < 0) {
75 		WARN_ON(err == -EMSGSIZE);
76 		kfree_skb(rep);
77 		goto out;
78 	}
79 	err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
80 			      MSG_DONTWAIT);
81 	if (err > 0)
82 		err = 0;
83 out:
84 	if (sk)
85 		sock_put(sk);
86 out_nosk:
87 	return err;
88 }
89 
90 static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlink_callback *cb,
91 		struct inet_diag_req *r, struct nlattr *bc)
92 {
93 	int num, s_num, slot, s_slot;
94 
95 	s_slot = cb->args[0];
96 	num = s_num = cb->args[1];
97 
98 	for (slot = s_slot; slot <= table->mask; num = s_num = 0, slot++) {
99 		struct sock *sk;
100 		struct hlist_nulls_node *node;
101 		struct udp_hslot *hslot = &table->hash[slot];
102 
103 		if (hlist_nulls_empty(&hslot->head))
104 			continue;
105 
106 		spin_lock_bh(&hslot->lock);
107 		sk_nulls_for_each(sk, node, &hslot->head) {
108 			struct inet_sock *inet = inet_sk(sk);
109 
110 			if (num < s_num)
111 				goto next;
112 			if (!(r->idiag_states & (1 << sk->sk_state)))
113 				goto next;
114 			if (r->sdiag_family != AF_UNSPEC &&
115 					sk->sk_family != r->sdiag_family)
116 				goto next;
117 			if (r->id.idiag_sport != inet->inet_sport &&
118 			    r->id.idiag_sport)
119 				goto next;
120 			if (r->id.idiag_dport != inet->inet_dport &&
121 			    r->id.idiag_dport)
122 				goto next;
123 
124 			if (sk_diag_dump(sk, skb, cb, r, bc) < 0) {
125 				spin_unlock_bh(&hslot->lock);
126 				goto done;
127 			}
128 next:
129 			num++;
130 		}
131 		spin_unlock_bh(&hslot->lock);
132 	}
133 done:
134 	cb->args[0] = slot;
135 	cb->args[1] = num;
136 }
137 
138 static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
139 		struct inet_diag_req *r, struct nlattr *bc)
140 {
141 	udp_dump(&udp_table, skb, cb, r, bc);
142 }
143 
144 static int udp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
145 		struct inet_diag_req *req)
146 {
147 	return udp_dump_one(&udp_table, in_skb, nlh, req);
148 }
149 
150 static const struct inet_diag_handler udp_diag_handler = {
151 	.dump		 = udp_diag_dump,
152 	.dump_one	 = udp_diag_dump_one,
153 	.idiag_type	 = IPPROTO_UDP,
154 };
155 
156 static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
157 		struct inet_diag_req *r, struct nlattr *bc)
158 {
159 	udp_dump(&udplite_table, skb, cb, r, bc);
160 }
161 
162 static int udplite_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh,
163 		struct inet_diag_req *req)
164 {
165 	return udp_dump_one(&udplite_table, in_skb, nlh, req);
166 }
167 
168 static const struct inet_diag_handler udplite_diag_handler = {
169 	.dump		 = udplite_diag_dump,
170 	.dump_one	 = udplite_diag_dump_one,
171 	.idiag_type	 = IPPROTO_UDPLITE,
172 };
173 
174 static int __init udp_diag_init(void)
175 {
176 	int err;
177 
178 	err = inet_diag_register(&udp_diag_handler);
179 	if (err)
180 		goto out;
181 	err = inet_diag_register(&udplite_diag_handler);
182 	if (err)
183 		goto out_lite;
184 out:
185 	return err;
186 out_lite:
187 	inet_diag_unregister(&udp_diag_handler);
188 	goto out;
189 }
190 
191 static void __exit udp_diag_exit(void)
192 {
193 	inet_diag_unregister(&udplite_diag_handler);
194 	inet_diag_unregister(&udp_diag_handler);
195 }
196 
197 module_init(udp_diag_init);
198 module_exit(udp_diag_exit);
199 MODULE_LICENSE("GPL");
200 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
201 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
202