xref: /openbmc/linux/net/ipv4/raw_diag.c (revision 8622a0e5)
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 struct sock *raw_lookup(struct net *net, struct sock *from,
38 			       const struct inet_diag_req_v2 *req)
39 {
40 	struct inet_diag_req_raw *r = (void *)req;
41 	struct sock *sk = NULL;
42 
43 	if (r->sdiag_family == AF_INET)
44 		sk = __raw_v4_lookup(net, from, r->sdiag_raw_protocol,
45 				     r->id.idiag_dst[0],
46 				     r->id.idiag_src[0],
47 				     r->id.idiag_if, 0);
48 #if IS_ENABLED(CONFIG_IPV6)
49 	else
50 		sk = __raw_v6_lookup(net, from, r->sdiag_raw_protocol,
51 				     (const struct in6_addr *)r->id.idiag_src,
52 				     (const struct in6_addr *)r->id.idiag_dst,
53 				     r->id.idiag_if, 0);
54 #endif
55 	return sk;
56 }
57 
58 static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
59 {
60 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
61 	struct sock *sk = NULL, *s;
62 	int slot;
63 
64 	if (IS_ERR(hashinfo))
65 		return ERR_CAST(hashinfo);
66 
67 	read_lock(&hashinfo->lock);
68 	for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
69 		sk_for_each(s, &hashinfo->ht[slot]) {
70 			sk = raw_lookup(net, s, r);
71 			if (sk) {
72 				/*
73 				 * Grab it and keep until we fill
74 				 * diag meaage to be reported, so
75 				 * caller should call sock_put then.
76 				 * We can do that because we're keeping
77 				 * hashinfo->lock here.
78 				 */
79 				sock_hold(sk);
80 				goto out_unlock;
81 			}
82 		}
83 	}
84 out_unlock:
85 	read_unlock(&hashinfo->lock);
86 
87 	return sk ? sk : ERR_PTR(-ENOENT);
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(sizeof(struct inet_diag_msg) +
105 			sizeof(struct inet_diag_meminfo) + 64,
106 			GFP_KERNEL);
107 	if (!rep) {
108 		sock_put(sk);
109 		return -ENOMEM;
110 	}
111 
112 	err = inet_sk_diag_fill(sk, NULL, rep, cb, r, 0,
113 				netlink_net_capable(in_skb, CAP_NET_ADMIN));
114 	sock_put(sk);
115 
116 	if (err < 0) {
117 		kfree_skb(rep);
118 		return err;
119 	}
120 
121 	err = netlink_unicast(net->diag_nlsk, rep,
122 			      NETLINK_CB(in_skb).portid,
123 			      MSG_DONTWAIT);
124 	if (err > 0)
125 		err = 0;
126 	return err;
127 }
128 
129 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
130 			struct netlink_callback *cb,
131 			const struct inet_diag_req_v2 *r,
132 			struct nlattr *bc, bool net_admin)
133 {
134 	if (!inet_diag_bc_sk(bc, sk))
135 		return 0;
136 
137 	return inet_sk_diag_fill(sk, NULL, skb, cb, r, NLM_F_MULTI, net_admin);
138 }
139 
140 static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
141 			  const struct inet_diag_req_v2 *r)
142 {
143 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
144 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
145 	struct net *net = sock_net(skb->sk);
146 	struct inet_diag_dump_data *cb_data;
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 	read_lock(&hashinfo->lock);
160 	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
161 		num = 0;
162 
163 		sk_for_each(sk, &hashinfo->ht[slot]) {
164 			struct inet_sock *inet = inet_sk(sk);
165 
166 			if (!net_eq(sock_net(sk), net))
167 				continue;
168 			if (num < s_num)
169 				goto next;
170 			if (sk->sk_family != r->sdiag_family)
171 				goto next;
172 			if (r->id.idiag_sport != inet->inet_sport &&
173 			    r->id.idiag_sport)
174 				goto next;
175 			if (r->id.idiag_dport != inet->inet_dport &&
176 			    r->id.idiag_dport)
177 				goto next;
178 			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
179 				goto out_unlock;
180 next:
181 			num++;
182 		}
183 	}
184 
185 out_unlock:
186 	read_unlock(&hashinfo->lock);
187 
188 	cb->args[0] = slot;
189 	cb->args[1] = num;
190 }
191 
192 static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
193 			      void *info)
194 {
195 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
196 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
197 }
198 
199 #ifdef CONFIG_INET_DIAG_DESTROY
200 static int raw_diag_destroy(struct sk_buff *in_skb,
201 			    const struct inet_diag_req_v2 *r)
202 {
203 	struct net *net = sock_net(in_skb->sk);
204 	struct sock *sk;
205 	int err;
206 
207 	sk = raw_sock_get(net, r);
208 	if (IS_ERR(sk))
209 		return PTR_ERR(sk);
210 	err = sock_diag_destroy(sk, ECONNABORTED);
211 	sock_put(sk);
212 	return err;
213 }
214 #endif
215 
216 static const struct inet_diag_handler raw_diag_handler = {
217 	.dump			= raw_diag_dump,
218 	.dump_one		= raw_diag_dump_one,
219 	.idiag_get_info		= raw_diag_get_info,
220 	.idiag_type		= IPPROTO_RAW,
221 	.idiag_info_size	= 0,
222 #ifdef CONFIG_INET_DIAG_DESTROY
223 	.destroy		= raw_diag_destroy,
224 #endif
225 };
226 
227 static void __always_unused __check_inet_diag_req_raw(void)
228 {
229 	/*
230 	 * Make sure the two structures are identical,
231 	 * except the @pad field.
232 	 */
233 #define __offset_mismatch(m1, m2)			\
234 	(offsetof(struct inet_diag_req_v2, m1) !=	\
235 	 offsetof(struct inet_diag_req_raw, m2))
236 
237 	BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
238 		     sizeof(struct inet_diag_req_raw));
239 	BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
240 	BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
241 	BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
242 	BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
243 	BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
244 	BUILD_BUG_ON(__offset_mismatch(id, id));
245 #undef __offset_mismatch
246 }
247 
248 static int __init raw_diag_init(void)
249 {
250 	return inet_diag_register(&raw_diag_handler);
251 }
252 
253 static void __exit raw_diag_exit(void)
254 {
255 	inet_diag_unregister(&raw_diag_handler);
256 }
257 
258 module_init(raw_diag_init);
259 module_exit(raw_diag_exit);
260 MODULE_LICENSE("GPL");
261 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
262 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
263