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 22static LIST_HEAD(rxrpc_security_methods); 23static DECLARE_RWSEM(rxrpc_security_sem); 24 25/* 26 * get an RxRPC security module 27 */ 28static 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 */ 36static 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 */ 44static 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; 61out: 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 */ 73int 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 93out: 94 up_write(&rxrpc_security_sem); 95 _leave(" = %d", ret); 96 return ret; 97} 98 99EXPORT_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 */ 107void 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 119EXPORT_SYMBOL_GPL(rxrpc_unregister_security); 120 121/* 122 * initialise the security on a client connection 123 */ 124int 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 if (!key->payload.data) 141 return -EKEYREJECTED; 142 token = key->payload.data; 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 */ 163int 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 195found_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 */ 226int 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 */ 240int 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 */ 252void 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