xref: /openbmc/linux/net/ipv4/raw_diag.c (revision 1edd0337)
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_head *hlist;
61 	struct sock *sk;
62 	int slot;
63 
64 	if (IS_ERR(hashinfo))
65 		return ERR_CAST(hashinfo);
66 
67 	rcu_read_lock();
68 	for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
69 		hlist = &hashinfo->ht[slot];
70 		sk_for_each_rcu(sk, hlist) {
71 			if (raw_lookup(net, sk, r)) {
72 				/*
73 				 * Grab it and keep until we fill
74 				 * diag message to be reported, so
75 				 * caller should call sock_put then.
76 				 */
77 				if (refcount_inc_not_zero(&sk->sk_refcnt))
78 					goto out_unlock;
79 			}
80 		}
81 	}
82 	sk = ERR_PTR(-ENOENT);
83 out_unlock:
84 	rcu_read_unlock();
85 
86 	return sk;
87 }
88 
89 static int raw_diag_dump_one(struct netlink_callback *cb,
90 			     const struct inet_diag_req_v2 *r)
91 {
92 	struct sk_buff *in_skb = cb->skb;
93 	struct sk_buff *rep;
94 	struct sock *sk;
95 	struct net *net;
96 	int err;
97 
98 	net = sock_net(in_skb->sk);
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, 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 = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
122 
123 	return err;
124 }
125 
126 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
127 			struct netlink_callback *cb,
128 			const struct inet_diag_req_v2 *r,
129 			struct nlattr *bc, bool net_admin)
130 {
131 	if (!inet_diag_bc_sk(bc, sk))
132 		return 0;
133 
134 	return inet_sk_diag_fill(sk, NULL, skb, cb, r, NLM_F_MULTI, net_admin);
135 }
136 
137 static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
138 			  const struct inet_diag_req_v2 *r)
139 {
140 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
141 	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
142 	struct net *net = sock_net(skb->sk);
143 	struct inet_diag_dump_data *cb_data;
144 	int num, s_num, slot, s_slot;
145 	struct hlist_head *hlist;
146 	struct sock *sk = NULL;
147 	struct nlattr *bc;
148 
149 	if (IS_ERR(hashinfo))
150 		return;
151 
152 	cb_data = cb->data;
153 	bc = cb_data->inet_diag_nla_bc;
154 	s_slot = cb->args[0];
155 	num = s_num = cb->args[1];
156 
157 	rcu_read_lock();
158 	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
159 		num = 0;
160 
161 		hlist = &hashinfo->ht[slot];
162 		sk_for_each_rcu(sk, hlist) {
163 			struct inet_sock *inet = inet_sk(sk);
164 
165 			if (!net_eq(sock_net(sk), net))
166 				continue;
167 			if (num < s_num)
168 				goto next;
169 			if (sk->sk_family != r->sdiag_family)
170 				goto next;
171 			if (r->id.idiag_sport != inet->inet_sport &&
172 			    r->id.idiag_sport)
173 				goto next;
174 			if (r->id.idiag_dport != inet->inet_dport &&
175 			    r->id.idiag_dport)
176 				goto next;
177 			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
178 				goto out_unlock;
179 next:
180 			num++;
181 		}
182 	}
183 
184 out_unlock:
185 	rcu_read_unlock();
186 
187 	cb->args[0] = slot;
188 	cb->args[1] = num;
189 }
190 
191 static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
192 			      void *info)
193 {
194 	r->idiag_rqueue = sk_rmem_alloc_get(sk);
195 	r->idiag_wqueue = sk_wmem_alloc_get(sk);
196 }
197 
198 #ifdef CONFIG_INET_DIAG_DESTROY
199 static int raw_diag_destroy(struct sk_buff *in_skb,
200 			    const struct inet_diag_req_v2 *r)
201 {
202 	struct net *net = sock_net(in_skb->sk);
203 	struct sock *sk;
204 	int err;
205 
206 	sk = raw_sock_get(net, r);
207 	if (IS_ERR(sk))
208 		return PTR_ERR(sk);
209 	err = sock_diag_destroy(sk, ECONNABORTED);
210 	sock_put(sk);
211 	return err;
212 }
213 #endif
214 
215 static const struct inet_diag_handler raw_diag_handler = {
216 	.dump			= raw_diag_dump,
217 	.dump_one		= raw_diag_dump_one,
218 	.idiag_get_info		= raw_diag_get_info,
219 	.idiag_type		= IPPROTO_RAW,
220 	.idiag_info_size	= 0,
221 #ifdef CONFIG_INET_DIAG_DESTROY
222 	.destroy		= raw_diag_destroy,
223 #endif
224 };
225 
226 static void __always_unused __check_inet_diag_req_raw(void)
227 {
228 	/*
229 	 * Make sure the two structures are identical,
230 	 * except the @pad field.
231 	 */
232 #define __offset_mismatch(m1, m2)			\
233 	(offsetof(struct inet_diag_req_v2, m1) !=	\
234 	 offsetof(struct inet_diag_req_raw, m2))
235 
236 	BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
237 		     sizeof(struct inet_diag_req_raw));
238 	BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
239 	BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
240 	BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
241 	BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
242 	BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
243 	BUILD_BUG_ON(__offset_mismatch(id, id));
244 #undef __offset_mismatch
245 }
246 
247 static int __init raw_diag_init(void)
248 {
249 	return inet_diag_register(&raw_diag_handler);
250 }
251 
252 static void __exit raw_diag_exit(void)
253 {
254 	inet_diag_unregister(&raw_diag_handler);
255 }
256 
257 module_init(raw_diag_init);
258 module_exit(raw_diag_exit);
259 MODULE_LICENSE("GPL");
260 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
261 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);
262