xref: /linux/net/ipv4/raw_diag.c (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
1 #include <linux/module.h>
2 
3 #include <linux/inet_diag.h>
4 #include <linux/sock_diag.h>
5 
6 #include <net/inet_sock.h>
7 #include <net/raw.h>
8 #include <net/rawv6.h>
9 
10 #ifdef pr_fmt
11 # undef pr_fmt
12 #endif
13 
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 
16 static struct raw_hashinfo *
17 raw_get_hashinfo(const struct inet_diag_req_v2 *r)
18 {
19 	if (r->sdiag_family == AF_INET) {
20 		return &raw_v4_hashinfo;
21 #if IS_ENABLED(CONFIG_IPV6)
22 	} else if (r->sdiag_family == AF_INET6) {
23 		return &raw_v6_hashinfo;
24 #endif
25 	} else {
26 		pr_warn_once("Unexpected inet family %d\n",
27 			     r->sdiag_family);
28 		WARN_ON_ONCE(1);
29 		return ERR_PTR(-EINVAL);
30 	}
31 }
32 
33 /*
34  * Due to requirement of not breaking user API we can't simply
35  * rename @pad field in inet_diag_req_v2 structure, instead
36  * use helper to figure it out.
37  */
38 
39 static struct sock *raw_lookup(struct net *net, struct sock *from,
40 			       const struct inet_diag_req_v2 *req)
41 {
42 	struct inet_diag_req_raw *r = (void *)req;
43 	struct sock *sk = NULL;
44 
45 	if (r->sdiag_family == AF_INET)
46 		sk = __raw_v4_lookup(net, from, r->sdiag_raw_protocol,
47 				     r->id.idiag_dst[0],
48 				     r->id.idiag_src[0],
49 				     r->id.idiag_if, 0);
50 #if IS_ENABLED(CONFIG_IPV6)
51 	else
52 		sk = __raw_v6_lookup(net, from, r->sdiag_raw_protocol,
53 				     (const struct in6_addr *)r->id.idiag_src,
54 				     (const struct in6_addr *)r->id.idiag_dst,
55 				     r->id.idiag_if, 0);
56 #endif
57 	return sk;
58 }
59 
60 static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
61 {
62 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
63 	struct sock *sk = NULL, *s;
64 	int slot;
65 
66 	if (IS_ERR(hashinfo))
67 		return ERR_CAST(hashinfo);
68 
69 	read_lock(&hashinfo->lock);
70 	for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
71 		sk_for_each(s, &hashinfo->ht[slot]) {
72 			sk = raw_lookup(net, s, r);
73 			if (sk) {
74 				/*
75 				 * Grab it and keep until we fill
76 				 * diag meaage to be reported, so
77 				 * caller should call sock_put then.
78 				 * We can do that because we're keeping
79 				 * hashinfo->lock here.
80 				 */
81 				sock_hold(sk);
82 				goto out_unlock;
83 			}
84 		}
85 	}
86 out_unlock:
87 	read_unlock(&hashinfo->lock);
88 
89 	return sk ? sk : ERR_PTR(-ENOENT);
90 }
91 
92 static int raw_diag_dump_one(struct sk_buff *in_skb,
93 			     const struct nlmsghdr *nlh,
94 			     const struct inet_diag_req_v2 *r)
95 {
96 	struct net *net = sock_net(in_skb->sk);
97 	struct sk_buff *rep;
98 	struct sock *sk;
99 	int err;
100 
101 	sk = raw_sock_get(net, r);
102 	if (IS_ERR(sk))
103 		return PTR_ERR(sk);
104 
105 	rep = nlmsg_new(sizeof(struct inet_diag_msg) +
106 			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, r,
114 				sk_user_ns(NETLINK_CB(in_skb).sk),
115 				NETLINK_CB(in_skb).portid,
116 				nlh->nlmsg_seq, 0, nlh,
117 				netlink_net_capable(in_skb, CAP_NET_ADMIN));
118 	sock_put(sk);
119 
120 	if (err < 0) {
121 		kfree_skb(rep);
122 		return err;
123 	}
124 
125 	err = netlink_unicast(net->diag_nlsk, rep,
126 			      NETLINK_CB(in_skb).portid,
127 			      MSG_DONTWAIT);
128 	if (err > 0)
129 		err = 0;
130 	return err;
131 }
132 
133 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
134 			struct netlink_callback *cb,
135 			const struct inet_diag_req_v2 *r,
136 			struct nlattr *bc, bool net_admin)
137 {
138 	if (!inet_diag_bc_sk(bc, sk))
139 		return 0;
140 
141 	return inet_sk_diag_fill(sk, NULL, skb, r,
142 				 sk_user_ns(NETLINK_CB(cb->skb).sk),
143 				 NETLINK_CB(cb->skb).portid,
144 				 cb->nlh->nlmsg_seq, NLM_F_MULTI,
145 				 cb->nlh, net_admin);
146 }
147 
148 static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
149 			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
150 {
151 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
152 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
153 	struct net *net = sock_net(skb->sk);
154 	int num, s_num, slot, s_slot;
155 	struct sock *sk = NULL;
156 
157 	if (IS_ERR(hashinfo))
158 		return;
159 
160 	s_slot = cb->args[0];
161 	num = s_num = cb->args[1];
162 
163 	read_lock(&hashinfo->lock);
164 	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
165 		num = 0;
166 
167 		sk_for_each(sk, &hashinfo->ht[slot]) {
168 			struct inet_sock *inet = inet_sk(sk);
169 
170 			if (!net_eq(sock_net(sk), net))
171 				continue;
172 			if (num < s_num)
173 				goto next;
174 			if (sk->sk_family != r->sdiag_family)
175 				goto next;
176 			if (r->id.idiag_sport != inet->inet_sport &&
177 			    r->id.idiag_sport)
178 				goto next;
179 			if (r->id.idiag_dport != inet->inet_dport &&
180 			    r->id.idiag_dport)
181 				goto next;
182 			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
183 				goto out_unlock;
184 next:
185 			num++;
186 		}
187 	}
188 
189 out_unlock:
190 	read_unlock(&hashinfo->lock);
191 
192 	cb->args[0] = slot;
193 	cb->args[1] = num;
194 }
195 
196 static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
197 			      void *info)
198 {
199 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
200 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
201 }
202 
203 #ifdef CONFIG_INET_DIAG_DESTROY
204 static int raw_diag_destroy(struct sk_buff *in_skb,
205 			    const struct inet_diag_req_v2 *r)
206 {
207 	struct net *net = sock_net(in_skb->sk);
208 	struct sock *sk;
209 	int err;
210 
211 	sk = raw_sock_get(net, r);
212 	if (IS_ERR(sk))
213 		return PTR_ERR(sk);
214 	err = sock_diag_destroy(sk, ECONNABORTED);
215 	sock_put(sk);
216 	return err;
217 }
218 #endif
219 
220 static const struct inet_diag_handler raw_diag_handler = {
221 	.dump			= raw_diag_dump,
222 	.dump_one		= raw_diag_dump_one,
223 	.idiag_get_info		= raw_diag_get_info,
224 	.idiag_type		= IPPROTO_RAW,
225 	.idiag_info_size	= 0,
226 #ifdef CONFIG_INET_DIAG_DESTROY
227 	.destroy		= raw_diag_destroy,
228 #endif
229 };
230 
231 static void __always_unused __check_inet_diag_req_raw(void)
232 {
233 	/*
234 	 * Make sure the two structures are identical,
235 	 * except the @pad field.
236 	 */
237 #define __offset_mismatch(m1, m2)			\
238 	(offsetof(struct inet_diag_req_v2, m1) !=	\
239 	 offsetof(struct inet_diag_req_raw, m2))
240 
241 	BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
242 		     sizeof(struct inet_diag_req_raw));
243 	BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
244 	BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
245 	BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
246 	BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
247 	BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
248 	BUILD_BUG_ON(__offset_mismatch(id, id));
249 #undef __offset_mismatch
250 }
251 
252 static int __init raw_diag_init(void)
253 {
254 	return inet_diag_register(&raw_diag_handler);
255 }
256 
257 static void __exit raw_diag_exit(void)
258 {
259 	inet_diag_unregister(&raw_diag_handler);
260 }
261 
262 module_init(raw_diag_init);
263 module_exit(raw_diag_exit);
264 MODULE_LICENSE("GPL");
265 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
266 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
267