xref: /linux/net/ipv4/raw_diag.c (revision c8fbf8a88fcd4464b0727d646a85793ccba49b03)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/module.h>
3 
4 #include <linux/inet_diag.h>
5 #include <linux/sock_diag.h>
6 
7 #include <net/inet_sock.h>
8 #include <net/raw.h>
9 #include <net/rawv6.h>
10 
11 #ifdef pr_fmt
12 # undef pr_fmt
13 #endif
14 
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 
17 static struct raw_hashinfo *
18 raw_get_hashinfo(const struct inet_diag_req_v2 *r)
19 {
20 	if (r->sdiag_family == AF_INET) {
21 		return &raw_v4_hashinfo;
22 #if IS_ENABLED(CONFIG_IPV6)
23 	} else if (r->sdiag_family == AF_INET6) {
24 		return &raw_v6_hashinfo;
25 #endif
26 	} else {
27 		return ERR_PTR(-EINVAL);
28 	}
29 }
30 
31 /*
32  * Due to requirement of not breaking user API we can't simply
33  * rename @pad field in inet_diag_req_v2 structure, instead
34  * use helper to figure it out.
35  */
36 
37 static bool raw_lookup(struct net *net, struct sock *sk,
38 		       const struct inet_diag_req_v2 *req)
39 {
40 	struct inet_diag_req_raw *r = (void *)req;
41 
42 	if (r->sdiag_family == AF_INET)
43 		return raw_v4_match(net, sk, r->sdiag_raw_protocol,
44 				    r->id.idiag_dst[0],
45 				    r->id.idiag_src[0],
46 				    r->id.idiag_if, 0);
47 #if IS_ENABLED(CONFIG_IPV6)
48 	else
49 		return raw_v6_match(net, sk, r->sdiag_raw_protocol,
50 				    (const struct in6_addr *)r->id.idiag_src,
51 				    (const struct in6_addr *)r->id.idiag_dst,
52 				    r->id.idiag_if, 0);
53 #endif
54 	return false;
55 }
56 
57 static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
58 {
59 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
60 	struct hlist_nulls_head *hlist;
61 	struct hlist_nulls_node *hnode;
62 	struct sock *sk;
63 	int slot;
64 
65 	if (IS_ERR(hashinfo))
66 		return ERR_CAST(hashinfo);
67 
68 	rcu_read_lock();
69 	for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
70 		hlist = &hashinfo->ht[slot];
71 		sk_nulls_for_each(sk, hnode, hlist) {
72 			if (raw_lookup(net, sk, r)) {
73 				/*
74 				 * Grab it and keep until we fill
75 				 * diag message to be reported, so
76 				 * caller should call sock_put then.
77 				 */
78 				if (refcount_inc_not_zero(&sk->sk_refcnt))
79 					goto out_unlock;
80 			}
81 		}
82 	}
83 	sk = ERR_PTR(-ENOENT);
84 out_unlock:
85 	rcu_read_unlock();
86 
87 	return sk;
88 }
89 
90 static int raw_diag_dump_one(struct netlink_callback *cb,
91 			     const struct inet_diag_req_v2 *r)
92 {
93 	struct sk_buff *in_skb = cb->skb;
94 	struct sk_buff *rep;
95 	struct sock *sk;
96 	struct net *net;
97 	int err;
98 
99 	net = sock_net(in_skb->sk);
100 	sk = raw_sock_get(net, r);
101 	if (IS_ERR(sk))
102 		return PTR_ERR(sk);
103 
104 	rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
105 			inet_diag_msg_attrs_size() +
106 			nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,
107 			GFP_KERNEL);
108 	if (!rep) {
109 		sock_put(sk);
110 		return -ENOMEM;
111 	}
112 
113 	err = inet_sk_diag_fill(sk, NULL, rep, cb, r, 0,
114 				netlink_net_capable(in_skb, CAP_NET_ADMIN));
115 	sock_put(sk);
116 
117 	if (err < 0) {
118 		kfree_skb(rep);
119 		return err;
120 	}
121 
122 	err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
123 
124 	return err;
125 }
126 
127 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
128 			struct netlink_callback *cb,
129 			const struct inet_diag_req_v2 *r,
130 			struct nlattr *bc, bool net_admin)
131 {
132 	if (!inet_diag_bc_sk(bc, sk))
133 		return 0;
134 
135 	return inet_sk_diag_fill(sk, NULL, skb, cb, r, NLM_F_MULTI, net_admin);
136 }
137 
138 static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
139 			  const struct inet_diag_req_v2 *r)
140 {
141 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
142 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
143 	struct net *net = sock_net(skb->sk);
144 	struct inet_diag_dump_data *cb_data;
145 	struct hlist_nulls_head *hlist;
146 	struct hlist_nulls_node *hnode;
147 	int num, s_num, slot, s_slot;
148 	struct sock *sk = NULL;
149 	struct nlattr *bc;
150 
151 	if (IS_ERR(hashinfo))
152 		return;
153 
154 	cb_data = cb->data;
155 	bc = cb_data->inet_diag_nla_bc;
156 	s_slot = cb->args[0];
157 	num = s_num = cb->args[1];
158 
159 	rcu_read_lock();
160 	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
161 		num = 0;
162 
163 		hlist = &hashinfo->ht[slot];
164 		sk_nulls_for_each(sk, hnode, hlist) {
165 			struct inet_sock *inet = inet_sk(sk);
166 
167 			if (!net_eq(sock_net(sk), net))
168 				continue;
169 			if (num < s_num)
170 				goto next;
171 			if (sk->sk_family != r->sdiag_family)
172 				goto next;
173 			if (r->id.idiag_sport != inet->inet_sport &&
174 			    r->id.idiag_sport)
175 				goto next;
176 			if (r->id.idiag_dport != inet->inet_dport &&
177 			    r->id.idiag_dport)
178 				goto next;
179 			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
180 				goto out_unlock;
181 next:
182 			num++;
183 		}
184 	}
185 
186 out_unlock:
187 	rcu_read_unlock();
188 
189 	cb->args[0] = slot;
190 	cb->args[1] = num;
191 }
192 
193 static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
194 			      void *info)
195 {
196 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
197 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
198 }
199 
200 #ifdef CONFIG_INET_DIAG_DESTROY
201 static int raw_diag_destroy(struct sk_buff *in_skb,
202 			    const struct inet_diag_req_v2 *r)
203 {
204 	struct net *net = sock_net(in_skb->sk);
205 	struct sock *sk;
206 	int err;
207 
208 	sk = raw_sock_get(net, r);
209 	if (IS_ERR(sk))
210 		return PTR_ERR(sk);
211 	err = sock_diag_destroy(sk, ECONNABORTED);
212 	sock_put(sk);
213 	return err;
214 }
215 #endif
216 
217 static const struct inet_diag_handler raw_diag_handler = {
218 	.dump			= raw_diag_dump,
219 	.dump_one		= raw_diag_dump_one,
220 	.idiag_get_info		= raw_diag_get_info,
221 	.idiag_type		= IPPROTO_RAW,
222 	.idiag_info_size	= 0,
223 #ifdef CONFIG_INET_DIAG_DESTROY
224 	.destroy		= raw_diag_destroy,
225 #endif
226 };
227 
228 static void __always_unused __check_inet_diag_req_raw(void)
229 {
230 	/*
231 	 * Make sure the two structures are identical,
232 	 * except the @pad field.
233 	 */
234 #define __offset_mismatch(m1, m2)			\
235 	(offsetof(struct inet_diag_req_v2, m1) !=	\
236 	 offsetof(struct inet_diag_req_raw, m2))
237 
238 	BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
239 		     sizeof(struct inet_diag_req_raw));
240 	BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
241 	BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
242 	BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
243 	BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
244 	BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
245 	BUILD_BUG_ON(__offset_mismatch(id, id));
246 #undef __offset_mismatch
247 }
248 
249 static int __init raw_diag_init(void)
250 {
251 	return inet_diag_register(&raw_diag_handler);
252 }
253 
254 static void __exit raw_diag_exit(void)
255 {
256 	inet_diag_unregister(&raw_diag_handler);
257 }
258 
259 module_init(raw_diag_init);
260 module_exit(raw_diag_exit);
261 MODULE_LICENSE("GPL");
262 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
263 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
264