xref: /openbmc/linux/net/ipv4/raw_diag.c (revision f9834f18)
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(sizeof(struct inet_diag_msg) +
104 			sizeof(struct inet_diag_meminfo) + 64,
105 			GFP_KERNEL);
106 	if (!rep) {
107 		sock_put(sk);
108 		return -ENOMEM;
109 	}
110 
111 	err = inet_sk_diag_fill(sk, NULL, rep, r,
112 				sk_user_ns(NETLINK_CB(in_skb).sk),
113 				NETLINK_CB(in_skb).portid,
114 				nlh->nlmsg_seq, 0, nlh,
115 				netlink_net_capable(in_skb, CAP_NET_ADMIN));
116 	sock_put(sk);
117 
118 	if (err < 0) {
119 		kfree_skb(rep);
120 		return err;
121 	}
122 
123 	err = netlink_unicast(net->diag_nlsk, rep,
124 			      NETLINK_CB(in_skb).portid,
125 			      MSG_DONTWAIT);
126 	if (err > 0)
127 		err = 0;
128 	return err;
129 }
130 
131 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
132 			struct netlink_callback *cb,
133 			const struct inet_diag_req_v2 *r,
134 			struct nlattr *bc, bool net_admin)
135 {
136 	if (!inet_diag_bc_sk(bc, sk))
137 		return 0;
138 
139 	return inet_sk_diag_fill(sk, NULL, skb, r,
140 				 sk_user_ns(NETLINK_CB(cb->skb).sk),
141 				 NETLINK_CB(cb->skb).portid,
142 				 cb->nlh->nlmsg_seq, NLM_F_MULTI,
143 				 cb->nlh, net_admin);
144 }
145 
146 static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
147 			  const struct inet_diag_req_v2 *r, struct nlattr *bc)
148 {
149 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
150 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
151 	struct net *net = sock_net(skb->sk);
152 	int num, s_num, slot, s_slot;
153 	struct sock *sk = NULL;
154 
155 	if (IS_ERR(hashinfo))
156 		return;
157 
158 	s_slot = cb->args[0];
159 	num = s_num = cb->args[1];
160 
161 	read_lock(&hashinfo->lock);
162 	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
163 		num = 0;
164 
165 		sk_for_each(sk, &hashinfo->ht[slot]) {
166 			struct inet_sock *inet = inet_sk(sk);
167 
168 			if (!net_eq(sock_net(sk), net))
169 				continue;
170 			if (num < s_num)
171 				goto next;
172 			if (sk->sk_family != r->sdiag_family)
173 				goto next;
174 			if (r->id.idiag_sport != inet->inet_sport &&
175 			    r->id.idiag_sport)
176 				goto next;
177 			if (r->id.idiag_dport != inet->inet_dport &&
178 			    r->id.idiag_dport)
179 				goto next;
180 			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
181 				goto out_unlock;
182 next:
183 			num++;
184 		}
185 	}
186 
187 out_unlock:
188 	read_unlock(&hashinfo->lock);
189 
190 	cb->args[0] = slot;
191 	cb->args[1] = num;
192 }
193 
194 static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
195 			      void *info)
196 {
197 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
198 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
199 }
200 
201 #ifdef CONFIG_INET_DIAG_DESTROY
202 static int raw_diag_destroy(struct sk_buff *in_skb,
203 			    const struct inet_diag_req_v2 *r)
204 {
205 	struct net *net = sock_net(in_skb->sk);
206 	struct sock *sk;
207 	int err;
208 
209 	sk = raw_sock_get(net, r);
210 	if (IS_ERR(sk))
211 		return PTR_ERR(sk);
212 	err = sock_diag_destroy(sk, ECONNABORTED);
213 	sock_put(sk);
214 	return err;
215 }
216 #endif
217 
218 static const struct inet_diag_handler raw_diag_handler = {
219 	.dump			= raw_diag_dump,
220 	.dump_one		= raw_diag_dump_one,
221 	.idiag_get_info		= raw_diag_get_info,
222 	.idiag_type		= IPPROTO_RAW,
223 	.idiag_info_size	= 0,
224 #ifdef CONFIG_INET_DIAG_DESTROY
225 	.destroy		= raw_diag_destroy,
226 #endif
227 };
228 
229 static void __always_unused __check_inet_diag_req_raw(void)
230 {
231 	/*
232 	 * Make sure the two structures are identical,
233 	 * except the @pad field.
234 	 */
235 #define __offset_mismatch(m1, m2)			\
236 	(offsetof(struct inet_diag_req_v2, m1) !=	\
237 	 offsetof(struct inet_diag_req_raw, m2))
238 
239 	BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
240 		     sizeof(struct inet_diag_req_raw));
241 	BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
242 	BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
243 	BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
244 	BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
245 	BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
246 	BUILD_BUG_ON(__offset_mismatch(id, id));
247 #undef __offset_mismatch
248 }
249 
250 static int __init raw_diag_init(void)
251 {
252 	return inet_diag_register(&raw_diag_handler);
253 }
254 
255 static void __exit raw_diag_exit(void)
256 {
257 	inet_diag_unregister(&raw_diag_handler);
258 }
259 
260 module_init(raw_diag_init);
261 module_exit(raw_diag_exit);
262 MODULE_LICENSE("GPL");
263 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
264 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
265