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/*
* X.25 Packet Layer release 001
*
* This is ALPHA test software. This code may break your machine, randomly fail to work with new
* releases, misbehave and/or generally screw up. It might even work.
*
* This code REQUIRES 2.1.15 or higher
*
* This module:
* This module 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.
*
* History
* X.25 001 Jonathan Naylor Started coding.
*/
#include <linux/config.h>
#if defined(CONFIG_X25) || defined(CONFIG_X25_MODULE)
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/x25.h>
static void x25_timer(unsigned long);
/*
* Linux set timer
*/
void x25_set_timer(struct sock *sk)
{
unsigned long flags;
save_flags(flags); cli();
del_timer(&sk->timer);
restore_flags(flags);
sk->timer.data = (unsigned long)sk;
sk->timer.function = &x25_timer;
sk->timer.expires = jiffies + (HZ / 1);
add_timer(&sk->timer);
}
/*
* X.25 TIMER
*
* This routine is called every second. Decrement timer by this
* amount - if expired then process the event.
*/
static void x25_timer(unsigned long param)
{
struct sock *sk = (struct sock *)param;
switch (sk->protinfo.x25->state) {
case X25_STATE_0:
/* Magic here: If we listen() and a new link dies before it
is accepted() it isn't 'dead' so doesn't get removed. */
if (sk->destroy || (sk->state == TCP_LISTEN && sk->dead)) {
del_timer(&sk->timer);
x25_destroy_socket(sk);
return;
}
break;
case X25_STATE_3:
/*
* Check for the state of the receive buffer.
*/
if (atomic_read(&sk->rmem_alloc) < (sk->rcvbuf / 2) &&
(sk->protinfo.x25->condition & X25_COND_OWN_RX_BUSY)) {
sk->protinfo.x25->condition &= ~X25_COND_OWN_RX_BUSY;
sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
sk->protinfo.x25->vl = sk->protinfo.x25->vr;
sk->protinfo.x25->timer = 0;
x25_write_internal(sk, X25_RR);
break;
}
/*
* Check for frames to transmit.
*/
x25_kick(sk);
break;
default:
break;
}
if (sk->protinfo.x25->timer == 0 || --sk->protinfo.x25->timer > 0) {
x25_set_timer(sk);
return;
}
/*
* Timer has expired, it may have been T2, T21, T22, or T23. We can tell
* by the state machine state.
*/
switch (sk->protinfo.x25->state) {
case X25_STATE_3: /* T2 */
if (sk->protinfo.x25->condition & X25_COND_ACK_PENDING) {
sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
x25_enquiry_response(sk);
}
break;
case X25_STATE_1: /* T21 */
case X25_STATE_4: /* T22 */
x25_write_internal(sk, X25_CLEAR_REQUEST);
sk->protinfo.x25->state = X25_STATE_2;
sk->protinfo.x25->timer = sk->protinfo.x25->t23;
break;
case X25_STATE_2: /* T23 */
x25_clear_queues(sk);
sk->protinfo.x25->state = X25_STATE_0;
sk->state = TCP_CLOSE;
sk->err = ETIMEDOUT;
sk->shutdown |= SEND_SHUTDOWN;
if (!sk->dead)
sk->state_change(sk);
sk->dead = 1;
break;
}
x25_set_timer(sk);
}
#endif
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