linux/net/rxrpc/ar-security.c

265 lines
5.6 KiB
C

/* RxRPC security handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/udp.h>
#include <linux/crypto.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <keys/rxrpc-type.h>
#include "ar-internal.h"
static LIST_HEAD(rxrpc_security_methods);
static DECLARE_RWSEM(rxrpc_security_sem);
/*
* get an RxRPC security module
*/
static struct rxrpc_security *rxrpc_security_get(struct rxrpc_security *sec)
{
return try_module_get(sec->owner) ? sec : NULL;
}
/*
* release an RxRPC security module
*/
static void rxrpc_security_put(struct rxrpc_security *sec)
{
module_put(sec->owner);
}
/*
* look up an rxrpc security module
*/
static struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
{
struct rxrpc_security *sec = NULL;
_enter("");
down_read(&rxrpc_security_sem);
list_for_each_entry(sec, &rxrpc_security_methods, link) {
if (sec->security_index == security_index) {
if (unlikely(!rxrpc_security_get(sec)))
break;
goto out;
}
}
sec = NULL;
out:
up_read(&rxrpc_security_sem);
_leave(" = %p [%s]", sec, sec ? sec->name : "");
return sec;
}
/**
* rxrpc_register_security - register an RxRPC security handler
* @sec: security module
*
* register an RxRPC security handler for use by RxRPC
*/
int rxrpc_register_security(struct rxrpc_security *sec)
{
struct rxrpc_security *psec;
int ret;
_enter("");
down_write(&rxrpc_security_sem);
ret = -EEXIST;
list_for_each_entry(psec, &rxrpc_security_methods, link) {
if (psec->security_index == sec->security_index)
goto out;
}
list_add(&sec->link, &rxrpc_security_methods);
printk(KERN_NOTICE "RxRPC: Registered security type %d '%s'\n",
sec->security_index, sec->name);
ret = 0;
out:
up_write(&rxrpc_security_sem);
_leave(" = %d", ret);
return ret;
}
EXPORT_SYMBOL_GPL(rxrpc_register_security);
/**
* rxrpc_unregister_security - unregister an RxRPC security handler
* @sec: security module
*
* unregister an RxRPC security handler
*/
void rxrpc_unregister_security(struct rxrpc_security *sec)
{
_enter("");
down_write(&rxrpc_security_sem);
list_del_init(&sec->link);
up_write(&rxrpc_security_sem);
printk(KERN_NOTICE "RxRPC: Unregistered security type %d '%s'\n",
sec->security_index, sec->name);
}
EXPORT_SYMBOL_GPL(rxrpc_unregister_security);
/*
* initialise the security on a client connection
*/
int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
{
struct rxrpc_key_token *token;
struct rxrpc_security *sec;
struct key *key = conn->key;
int ret;
_enter("{%d},{%x}", conn->debug_id, key_serial(key));
if (!key)
return 0;
ret = key_validate(key);
if (ret < 0)
return ret;
token = key->payload.data[0];
if (!token)
return -EKEYREJECTED;
sec = rxrpc_security_lookup(token->security_index);
if (!sec)
return -EKEYREJECTED;
conn->security = sec;
ret = conn->security->init_connection_security(conn);
if (ret < 0) {
rxrpc_security_put(conn->security);
conn->security = NULL;
return ret;
}
_leave(" = 0");
return 0;
}
/*
* initialise the security on a server connection
*/
int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
{
struct rxrpc_security *sec;
struct rxrpc_local *local = conn->trans->local;
struct rxrpc_sock *rx;
struct key *key;
key_ref_t kref;
char kdesc[5 + 1 + 3 + 1];
_enter("");
sprintf(kdesc, "%u:%u", conn->service_id, conn->security_ix);
sec = rxrpc_security_lookup(conn->security_ix);
if (!sec) {
_leave(" = -ENOKEY [lookup]");
return -ENOKEY;
}
/* find the service */
read_lock_bh(&local->services_lock);
list_for_each_entry(rx, &local->services, listen_link) {
if (rx->srx.srx_service == conn->service_id)
goto found_service;
}
/* the service appears to have died */
read_unlock_bh(&local->services_lock);
rxrpc_security_put(sec);
_leave(" = -ENOENT");
return -ENOENT;
found_service:
if (!rx->securities) {
read_unlock_bh(&local->services_lock);
rxrpc_security_put(sec);
_leave(" = -ENOKEY");
return -ENOKEY;
}
/* look through the service's keyring */
kref = keyring_search(make_key_ref(rx->securities, 1UL),
&key_type_rxrpc_s, kdesc);
if (IS_ERR(kref)) {
read_unlock_bh(&local->services_lock);
rxrpc_security_put(sec);
_leave(" = %ld [search]", PTR_ERR(kref));
return PTR_ERR(kref);
}
key = key_ref_to_ptr(kref);
read_unlock_bh(&local->services_lock);
conn->server_key = key;
conn->security = sec;
_leave(" = 0");
return 0;
}
/*
* secure a packet prior to transmission
*/
int rxrpc_secure_packet(const struct rxrpc_call *call,
struct sk_buff *skb,
size_t data_size,
void *sechdr)
{
if (call->conn->security)
return call->conn->security->secure_packet(
call, skb, data_size, sechdr);
return 0;
}
/*
* secure a packet prior to transmission
*/
int rxrpc_verify_packet(const struct rxrpc_call *call, struct sk_buff *skb,
u32 *_abort_code)
{
if (call->conn->security)
return call->conn->security->verify_packet(
call, skb, _abort_code);
return 0;
}
/*
* clear connection security
*/
void rxrpc_clear_conn_security(struct rxrpc_connection *conn)
{
_enter("{%d}", conn->debug_id);
if (conn->security) {
conn->security->clear(conn);
rxrpc_security_put(conn->security);
conn->security = NULL;
}
key_put(conn->key);
key_put(conn->server_key);
}