1 /* RxRPC security handling
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #include <linux/module.h>
13 #include <linux/net.h>
14 #include <linux/skbuff.h>
15 #include <linux/udp.h>
16 #include <linux/crypto.h>
17 #include <net/sock.h>
18 #include <net/af_rxrpc.h>
19 #include <keys/rxrpc-type.h>
20 #include "ar-internal.h"
21
22 static LIST_HEAD(rxrpc_security_methods);
23 static DECLARE_RWSEM(rxrpc_security_sem);
24
25 /*
26 * get an RxRPC security module
27 */
rxrpc_security_get(struct rxrpc_security * sec)28 static struct rxrpc_security *rxrpc_security_get(struct rxrpc_security *sec)
29 {
30 return try_module_get(sec->owner) ? sec : NULL;
31 }
32
33 /*
34 * release an RxRPC security module
35 */
rxrpc_security_put(struct rxrpc_security * sec)36 static void rxrpc_security_put(struct rxrpc_security *sec)
37 {
38 module_put(sec->owner);
39 }
40
41 /*
42 * look up an rxrpc security module
43 */
rxrpc_security_lookup(u8 security_index)44 static struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
45 {
46 struct rxrpc_security *sec = NULL;
47
48 _enter("");
49
50 down_read(&rxrpc_security_sem);
51
52 list_for_each_entry(sec, &rxrpc_security_methods, link) {
53 if (sec->security_index == security_index) {
54 if (unlikely(!rxrpc_security_get(sec)))
55 break;
56 goto out;
57 }
58 }
59
60 sec = NULL;
61 out:
62 up_read(&rxrpc_security_sem);
63 _leave(" = %p [%s]", sec, sec ? sec->name : "");
64 return sec;
65 }
66
67 /**
68 * rxrpc_register_security - register an RxRPC security handler
69 * @sec: security module
70 *
71 * register an RxRPC security handler for use by RxRPC
72 */
rxrpc_register_security(struct rxrpc_security * sec)73 int rxrpc_register_security(struct rxrpc_security *sec)
74 {
75 struct rxrpc_security *psec;
76 int ret;
77
78 _enter("");
79 down_write(&rxrpc_security_sem);
80
81 ret = -EEXIST;
82 list_for_each_entry(psec, &rxrpc_security_methods, link) {
83 if (psec->security_index == sec->security_index)
84 goto out;
85 }
86
87 list_add(&sec->link, &rxrpc_security_methods);
88
89 printk(KERN_NOTICE "RxRPC: Registered security type %d '%s'\n",
90 sec->security_index, sec->name);
91 ret = 0;
92
93 out:
94 up_write(&rxrpc_security_sem);
95 _leave(" = %d", ret);
96 return ret;
97 }
98
99 EXPORT_SYMBOL_GPL(rxrpc_register_security);
100
101 /**
102 * rxrpc_unregister_security - unregister an RxRPC security handler
103 * @sec: security module
104 *
105 * unregister an RxRPC security handler
106 */
rxrpc_unregister_security(struct rxrpc_security * sec)107 void rxrpc_unregister_security(struct rxrpc_security *sec)
108 {
109
110 _enter("");
111 down_write(&rxrpc_security_sem);
112 list_del_init(&sec->link);
113 up_write(&rxrpc_security_sem);
114
115 printk(KERN_NOTICE "RxRPC: Unregistered security type %d '%s'\n",
116 sec->security_index, sec->name);
117 }
118
119 EXPORT_SYMBOL_GPL(rxrpc_unregister_security);
120
121 /*
122 * initialise the security on a client connection
123 */
rxrpc_init_client_conn_security(struct rxrpc_connection * conn)124 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
125 {
126 struct rxrpc_key_token *token;
127 struct rxrpc_security *sec;
128 struct key *key = conn->key;
129 int ret;
130
131 _enter("{%d},{%x}", conn->debug_id, key_serial(key));
132
133 if (!key)
134 return 0;
135
136 ret = key_validate(key);
137 if (ret < 0)
138 return ret;
139
140 token = key->payload.data[0];
141 if (!token)
142 return -EKEYREJECTED;
143
144 sec = rxrpc_security_lookup(token->security_index);
145 if (!sec)
146 return -EKEYREJECTED;
147 conn->security = sec;
148
149 ret = conn->security->init_connection_security(conn);
150 if (ret < 0) {
151 rxrpc_security_put(conn->security);
152 conn->security = NULL;
153 return ret;
154 }
155
156 _leave(" = 0");
157 return 0;
158 }
159
160 /*
161 * initialise the security on a server connection
162 */
rxrpc_init_server_conn_security(struct rxrpc_connection * conn)163 int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
164 {
165 struct rxrpc_security *sec;
166 struct rxrpc_local *local = conn->trans->local;
167 struct rxrpc_sock *rx;
168 struct key *key;
169 key_ref_t kref;
170 char kdesc[5+1+3+1];
171
172 _enter("");
173
174 sprintf(kdesc, "%u:%u", ntohs(conn->service_id), conn->security_ix);
175
176 sec = rxrpc_security_lookup(conn->security_ix);
177 if (!sec) {
178 _leave(" = -ENOKEY [lookup]");
179 return -ENOKEY;
180 }
181
182 /* find the service */
183 read_lock_bh(&local->services_lock);
184 list_for_each_entry(rx, &local->services, listen_link) {
185 if (rx->service_id == conn->service_id)
186 goto found_service;
187 }
188
189 /* the service appears to have died */
190 read_unlock_bh(&local->services_lock);
191 rxrpc_security_put(sec);
192 _leave(" = -ENOENT");
193 return -ENOENT;
194
195 found_service:
196 if (!rx->securities) {
197 read_unlock_bh(&local->services_lock);
198 rxrpc_security_put(sec);
199 _leave(" = -ENOKEY");
200 return -ENOKEY;
201 }
202
203 /* look through the service's keyring */
204 kref = keyring_search(make_key_ref(rx->securities, 1UL),
205 &key_type_rxrpc_s, kdesc);
206 if (IS_ERR(kref)) {
207 read_unlock_bh(&local->services_lock);
208 rxrpc_security_put(sec);
209 _leave(" = %ld [search]", PTR_ERR(kref));
210 return PTR_ERR(kref);
211 }
212
213 key = key_ref_to_ptr(kref);
214 read_unlock_bh(&local->services_lock);
215
216 conn->server_key = key;
217 conn->security = sec;
218
219 _leave(" = 0");
220 return 0;
221 }
222
223 /*
224 * secure a packet prior to transmission
225 */
rxrpc_secure_packet(const struct rxrpc_call * call,struct sk_buff * skb,size_t data_size,void * sechdr)226 int rxrpc_secure_packet(const struct rxrpc_call *call,
227 struct sk_buff *skb,
228 size_t data_size,
229 void *sechdr)
230 {
231 if (call->conn->security)
232 return call->conn->security->secure_packet(
233 call, skb, data_size, sechdr);
234 return 0;
235 }
236
237 /*
238 * secure a packet prior to transmission
239 */
rxrpc_verify_packet(const struct rxrpc_call * call,struct sk_buff * skb,u32 * _abort_code)240 int rxrpc_verify_packet(const struct rxrpc_call *call, struct sk_buff *skb,
241 u32 *_abort_code)
242 {
243 if (call->conn->security)
244 return call->conn->security->verify_packet(
245 call, skb, _abort_code);
246 return 0;
247 }
248
249 /*
250 * clear connection security
251 */
rxrpc_clear_conn_security(struct rxrpc_connection * conn)252 void rxrpc_clear_conn_security(struct rxrpc_connection *conn)
253 {
254 _enter("{%d}", conn->debug_id);
255
256 if (conn->security) {
257 conn->security->clear(conn);
258 rxrpc_security_put(conn->security);
259 conn->security = NULL;
260 }
261
262 key_put(conn->key);
263 key_put(conn->server_key);
264 }
265