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 const struct rxrpc_security *rxrpc_security_types[] = {
 23	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
 24#ifdef CONFIG_RXKAD
 25	[RXRPC_SECURITY_RXKAD]	= &rxkad,
 26#endif
 27};
 28
 29int __init rxrpc_init_security(void)
 30{
 31	int i, ret;
 32
 33	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
 34		if (rxrpc_security_types[i]) {
 35			ret = rxrpc_security_types[i]->init();
 36			if (ret < 0)
 37				goto failed;
 38		}
 39	}
 40
 41	return 0;
 42
 43failed:
 44	for (i--; i >= 0; i--)
 45		if (rxrpc_security_types[i])
 46			rxrpc_security_types[i]->exit();
 47	return ret;
 48}
 49
 50void rxrpc_exit_security(void)
 51{
 52	int i;
 53
 54	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
 55		if (rxrpc_security_types[i])
 56			rxrpc_security_types[i]->exit();
 57}
 58
 59/*
 60 * look up an rxrpc security module
 61 */
 62static const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
 63{
 64	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
 65		return NULL;
 66	return rxrpc_security_types[security_index];
 67}
 68
 69/*
 70 * initialise the security on a client connection
 71 */
 72int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
 73{
 74	const struct rxrpc_security *sec;
 75	struct rxrpc_key_token *token;
 76	struct key *key = conn->params.key;
 77	int ret;
 78
 79	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
 80
 81	if (!key)
 82		return 0;
 83
 84	ret = key_validate(key);
 85	if (ret < 0)
 86		return ret;
 87
 88	token = key->payload.data[0];
 89	if (!token)
 90		return -EKEYREJECTED;
 91
 92	sec = rxrpc_security_lookup(token->security_index);
 93	if (!sec)
 94		return -EKEYREJECTED;
 95	conn->security = sec;
 96
 97	ret = conn->security->init_connection_security(conn);
 98	if (ret < 0) {
 99		conn->security = &rxrpc_no_security;
100		return ret;
101	}
102
103	_leave(" = 0");
104	return 0;
105}
106
107/*
108 * initialise the security on a server connection
109 */
110int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
111{
112	const struct rxrpc_security *sec;
113	struct rxrpc_local *local = conn->params.local;
114	struct rxrpc_sock *rx;
115	struct key *key;
116	key_ref_t kref;
117	char kdesc[5 + 1 + 3 + 1];
118
119	_enter("");
120
121	sprintf(kdesc, "%u:%u", conn->service_id, conn->security_ix);
122
123	sec = rxrpc_security_lookup(conn->security_ix);
124	if (!sec) {
125		_leave(" = -ENOKEY [lookup]");
126		return -ENOKEY;
127	}
128
129	/* find the service */
130	read_lock(&local->services_lock);
131	rx = rcu_dereference_protected(local->service,
132				       lockdep_is_held(&local->services_lock));
133	if (rx && (rx->srx.srx_service == conn->service_id ||
134		   rx->second_service == conn->service_id))
135		goto found_service;
136
137	/* the service appears to have died */
138	read_unlock(&local->services_lock);
139	_leave(" = -ENOENT");
140	return -ENOENT;
141
142found_service:
143	if (!rx->securities) {
144		read_unlock(&local->services_lock);
145		_leave(" = -ENOKEY");
146		return -ENOKEY;
147	}
148
149	/* look through the service's keyring */
150	kref = keyring_search(make_key_ref(rx->securities, 1UL),
151			      &key_type_rxrpc_s, kdesc);
152	if (IS_ERR(kref)) {
153		read_unlock(&local->services_lock);
154		_leave(" = %ld [search]", PTR_ERR(kref));
155		return PTR_ERR(kref);
156	}
157
158	key = key_ref_to_ptr(kref);
159	read_unlock(&local->services_lock);
160
161	conn->server_key = key;
162	conn->security = sec;
163
164	_leave(" = 0");
165	return 0;
166}