xref: /openbmc/linux/net/ipv4/raw_diag.c (revision 2985bed6)
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 sk_buff *in_skb,
91 			     const struct nlmsghdr *nlh,
92 			     const struct inet_diag_req_v2 *r)
93 {
94 	struct net *net = sock_net(in_skb->sk);
95 	struct sk_buff *rep;
96 	struct sock *sk;
97 	int err;
98 
99 	sk = raw_sock_get(net, r);
100 	if (IS_ERR(sk))
101 		return PTR_ERR(sk);
102 
103 	rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
104 			inet_diag_msg_attrs_size() +
105 			nla_total_size(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, r,
113 				sk_user_ns(NETLINK_CB(in_skb).sk),
114 				NETLINK_CB(in_skb).portid,
115 				nlh->nlmsg_seq, 0, nlh,
116 				netlink_net_capable(in_skb, CAP_NET_ADMIN));
117 	sock_put(sk);
118 
119 	if (err < 0) {
120 		kfree_skb(rep);
121 		return err;
122 	}
123 
124 	err = netlink_unicast(net->diag_nlsk, rep,
125 			      NETLINK_CB(in_skb).portid,
126 			      MSG_DONTWAIT);
127 	if (err > 0)
128 		err = 0;
129 	return err;
130 }
131 
132 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
133 			struct netlink_callback *cb,
134 			const struct inet_diag_req_v2 *r,
135 			struct nlattr *bc, bool net_admin)
136 {
137 	if (!inet_diag_bc_sk(bc, sk))
138 		return 0;
139 
140 	return inet_sk_diag_fill(sk, NULL, skb, r,
141 				 sk_user_ns(NETLINK_CB(cb->skb).sk),
142 				 NETLINK_CB(cb->skb).portid,
143 				 cb->nlh->nlmsg_seq, NLM_F_MULTI,
144 				 cb->nlh, net_admin);
145 }
146 
147 static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
148 			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
149 {
150 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
151 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
152 	struct net *net = sock_net(skb->sk);
153 	int num, s_num, slot, s_slot;
154 	struct sock *sk = NULL;
155 
156 	if (IS_ERR(hashinfo))
157 		return;
158 
159 	s_slot = cb->args[0];
160 	num = s_num = cb->args[1];
161 
162 	read_lock(&hashinfo->lock);
163 	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
164 		num = 0;
165 
166 		sk_for_each(sk, &hashinfo->ht[slot]) {
167 			struct inet_sock *inet = inet_sk(sk);
168 
169 			if (!net_eq(sock_net(sk), net))
170 				continue;
171 			if (num < s_num)
172 				goto next;
173 			if (sk->sk_family != r->sdiag_family)
174 				goto next;
175 			if (r->id.idiag_sport != inet->inet_sport &&
176 			    r->id.idiag_sport)
177 				goto next;
178 			if (r->id.idiag_dport != inet->inet_dport &&
179 			    r->id.idiag_dport)
180 				goto next;
181 			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
182 				goto out_unlock;
183 next:
184 			num++;
185 		}
186 	}
187 
188 out_unlock:
189 	read_unlock(&hashinfo->lock);
190 
191 	cb->args[0] = slot;
192 	cb->args[1] = num;
193 }
194 
195 static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
196 			      void *info)
197 {
198 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
199 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
200 }
201 
202 #ifdef CONFIG_INET_DIAG_DESTROY
203 static int raw_diag_destroy(struct sk_buff *in_skb,
204 			    const struct inet_diag_req_v2 *r)
205 {
206 	struct net *net = sock_net(in_skb->sk);
207 	struct sock *sk;
208 	int err;
209 
210 	sk = raw_sock_get(net, r);
211 	if (IS_ERR(sk))
212 		return PTR_ERR(sk);
213 	err = sock_diag_destroy(sk, ECONNABORTED);
214 	sock_put(sk);
215 	return err;
216 }
217 #endif
218 
219 static const struct inet_diag_handler raw_diag_handler = {
220 	.dump			= raw_diag_dump,
221 	.dump_one		= raw_diag_dump_one,
222 	.idiag_get_info		= raw_diag_get_info,
223 	.idiag_type		= IPPROTO_RAW,
224 	.idiag_info_size	= 0,
225 #ifdef CONFIG_INET_DIAG_DESTROY
226 	.destroy		= raw_diag_destroy,
227 #endif
228 };
229 
230 static void __always_unused __check_inet_diag_req_raw(void)
231 {
232 	/*
233 	 * Make sure the two structures are identical,
234 	 * except the @pad field.
235 	 */
236 #define __offset_mismatch(m1, m2)			\
237 	(offsetof(struct inet_diag_req_v2, m1) !=	\
238 	 offsetof(struct inet_diag_req_raw, m2))
239 
240 	BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
241 		     sizeof(struct inet_diag_req_raw));
242 	BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
243 	BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
244 	BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
245 	BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
246 	BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
247 	BUILD_BUG_ON(__offset_mismatch(id, id));
248 #undef __offset_mismatch
249 }
250 
251 static int __init raw_diag_init(void)
252 {
253 	return inet_diag_register(&raw_diag_handler);
254 }
255 
256 static void __exit raw_diag_exit(void)
257 {
258 	inet_diag_unregister(&raw_diag_handler);
259 }
260 
261 module_init(raw_diag_init);
262 module_exit(raw_diag_exit);
263 MODULE_LICENSE("GPL");
264 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
265 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
266