/* krxsecd.c: Rx security daemon
*
* Copyright (C) 2002 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.
*
* This daemon deals with:
* - consulting the application as to whether inbound peers and calls should be authorised
* - generating security challenges for inbound connections
* - responding to security challenges on outbound connections
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <rxrpc/krxsecd.h>
#include <rxrpc/transport.h>
#include <rxrpc/connection.h>
#include <rxrpc/message.h>
#include <rxrpc/peer.h>
#include <rxrpc/call.h>
#include <linux/udp.h>
#include <linux/ip.h>
#include <net/sock.h>
#include "internal.h"
static DECLARE_WAIT_QUEUE_HEAD(rxrpc_krxsecd_sleepq);
static DECLARE_COMPLETION(rxrpc_krxsecd_dead);
static volatile int rxrpc_krxsecd_die;
static atomic_t rxrpc_krxsecd_qcount;
/* queue of unprocessed inbound messages with seqno #1 and
* RXRPC_CLIENT_INITIATED flag set */
static LIST_HEAD(rxrpc_krxsecd_initmsgq);
static DEFINE_SPINLOCK(rxrpc_krxsecd_initmsgq_lock);
static void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg);
/*****************************************************************************/
/*
* Rx security daemon
*/
static int rxrpc_krxsecd(void *arg)
{
DECLARE_WAITQUEUE(krxsecd, current);
int die;
printk("Started krxsecd %d\n", current->pid);
daemonize("krxsecd");
/* loop around waiting for work to do */
do {
/* wait for work or to be told to exit */
_debug("### Begin Wait");
if (!atomic_read(&rxrpc_krxsecd_qcount)) {
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
if (atomic_read(&rxrpc_krxsecd_qcount) ||
rxrpc_krxsecd_die ||
signal_pending(current))
break;
schedule();
}
remove_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd);
set_current_state(TASK_RUNNING);
}
die = rxrpc_krxsecd_die;
_debug("### End Wait");
/* see if there're incoming calls in need of authenticating */
_debug("### Begin Inbound Calls");
if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
struct rxrpc_message *msg = NULL;
spin_lock(&rxrpc_krxsecd_initmsgq_lock);
if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
msg = list_entry(rxrpc_krxsecd_initmsgq.next,
struct rxrpc_message, link);
list_del_init(&msg->link);
atomic_dec(&rxrpc_krxsecd_qcount);
}
spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
if (msg) {
rxrpc_krxsecd_process_incoming_call(msg);
rxrpc_put_message(msg);
}
}
_debug("### End Inbound Calls");
try_to_freeze(PF_FREEZE);
/* discard pending signals */
rxrpc_discard_my_signals();
} while (!die);
/* and that's all */
complete_and_exit(&rxrpc_krxsecd_dead, 0);
} /* end rxrpc_krxsecd() */
/*****************************************************************************/
/*
* start up a krxsecd daemon
*/
int __init rxrpc_krxsecd_init(void)
{
return kernel_thread(rxrpc_krxsecd, NULL, 0);
} /* end rxrpc_krxsecd_init() */
/*****************************************************************************/
/*
* kill the krxsecd daemon and wait for it to complete
*/
void rxrpc_krxsecd_kill(void)
{
rxrpc_krxsecd_die = 1;
wake_up_all(&rxrpc_krxsecd_sleepq);
wait_for_completion(&rxrpc_krxsecd_dead);
} /* end rxrpc_krxsecd_kill() */
/*****************************************************************************/
/*
* clear all pending incoming calls for the specified transport
*/
void rxrpc_krxsecd_clear_transport(struct rxrpc_transport *trans)
{
LIST_HEAD(tmp);
struct rxrpc_message *msg;
struct list_head *_p, *_n;
_enter("%p",trans);
/* move all the messages for this transport onto a temp list */
spin_lock(&rxrpc_krxsecd_initmsgq_lock);
list_for_each_safe(_p, _n, &rxrpc_krxsecd_initmsgq) {
msg = list_entry(_p, struct rxrpc_message, link);
if (msg->trans == trans) {
list_del(&msg->link);
list_add_tail(&msg->link, &tmp);
atomic_dec(&rxrpc_krxsecd_qcount);
}
}
spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
/* zap all messages on the temp list */
while (!list_empty(&tmp)) {
msg = list_entry(tmp.next, struct rxrpc_message, link);
list_del_init(&msg->link);
rxrpc_put_message(msg);
}
_leave("");
} /* end rxrpc_krxsecd_clear_transport() */
/*****************************************************************************/
/*
* queue a message on the incoming calls list
*/
void rxrpc_krxsecd_queue_incoming_call(struct rxrpc_message *msg)
{
_enter("%p", msg);
/* queue for processing by krxsecd */
spin_lock(&rxrpc_krxsecd_initmsgq_lock);
if (!rxrpc_krxsecd_die) {
rxrpc_get_message(msg);
list_add_tail(&msg->link, &rxrpc_krxsecd_initmsgq);
atomic_inc(&rxrpc_krxsecd_qcount);
}
spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
wake_up(&rxrpc_krxsecd_sleepq);
_leave("");
} /* end rxrpc_krxsecd_queue_incoming_call() */
/*****************************************************************************/
/*
* process the initial message of an incoming call
*/
void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg)
{
struct rxrpc_transport *trans = msg->trans;
struct rxrpc_service *srv;
struct rxrpc_call *call;
struct list_head *_p;
unsigned short sid;
int ret;
_enter("%p{tr=%p}", msg, trans);
ret = rxrpc_incoming_call(msg->conn, msg, &call);
if (ret < 0)
goto out;
/* find the matching service on the transport */
sid = ntohs(msg->hdr.serviceId);
srv = NULL;
spin_lock(&trans->lock);
list_for_each(_p, &trans->services) {
srv = list_entry(_p, struct rxrpc_service, link);
if (srv->service_id == sid && try_module_get(srv->owner)) {
/* found a match (made sure it won't vanish) */
_debug("found service '%s'", srv->name);
call->owner = srv->owner;
break;
}
}
spin_unlock(&trans->lock);
/* report the new connection
* - the func must inc the call's usage count to keep it
*/
ret = -ENOENT;
if (_p != &trans->services) {
/* attempt to accept the call */
call->conn->service = srv;
call->app_attn_func = srv->attn_func;
call->app_error_func = srv->error_func;
call->app_aemap_func = srv->aemap_func;
ret = srv->new_call(call);
/* send an abort if an error occurred */
if (ret < 0) {
rxrpc_call_abort(call, ret);
}
else {
/* formally receive and ACK the new packet */
ret = rxrpc_conn_receive_call_packet(call->conn,
call, msg);
}
}
rxrpc_put_call(call);
out:
if (ret < 0)
rxrpc_trans_immediate_abort(trans, msg, ret);
_leave(" (%d)", ret);
} /* end rxrpc_krxsecd_process_incoming_call() */
