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/*
* LAPB 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/ NET3.038
*
* 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
* LAPB 001 Jonathan Naylor Started Coding
*/
#include <linux/config.h>
#if defined(CONFIG_LAPB) || defined(CONFIG_LAPB_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/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/lapb.h>
static void lapb_timer(unsigned long);
/*
* Linux set timer
*/
void lapb_set_timer(lapb_cb *lapb)
{
unsigned long flags;
save_flags(flags); cli();
del_timer(&lapb->timer);
restore_flags(flags);
lapb->timer.data = (unsigned long)lapb;
lapb->timer.function = &lapb_timer;
lapb->timer.expires = jiffies + (HZ / 10);
add_timer(&lapb->timer);
}
/*
* LAPB TIMER
*
* This routine is called every 100ms. Decrement timer by this
* amount - if expired then process the event.
*/
static void lapb_timer(unsigned long param)
{
lapb_cb *lapb = (lapb_cb *)param;
struct sk_buff *skb;
/*
* Process all packet received since the last clock tick.
*/
while ((skb = skb_dequeue(&lapb->input_queue)) != NULL)
lapb_data_input(lapb, skb);
/*
* If in a data transfer state, transmit any data.
*/
if (lapb->state == LAPB_STATE_3)
lapb_kick(lapb);
/*
* T2 expiry code.
*/
if (lapb->t2timer > 0 && --lapb->t2timer == 0) {
if (lapb->state == LAPB_STATE_3) {
if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
lapb_timeout_response(lapb);
}
}
}
/*
* If T1 isn't running, or hasn't timed out yet, keep going.
*/
if (lapb->t1timer == 0 || --lapb->t1timer > 0) {
lapb_set_timer(lapb);
return;
}
/*
* T1 has expired.
*/
switch (lapb->state) {
/*
* If we are a DCE, keep going DM .. DM .. DM
*/
case LAPB_STATE_0:
if (lapb->mode & LAPB_DCE)
lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
break;
/*
* Awaiting connection state, send SABM(E), up to N2 times.
*/
case LAPB_STATE_1:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb->t2timer = 0;
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->token);
#endif
} else {
lapb->n2count++;
if (lapb->mode & LAPB_EXTENDED) {
#if LAPB_DEBUG > 1
printk(KERN_DEBUG "lapb: (%p) S1 TX SABME(1)\n", lapb->token);
#endif
lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
} else {
#if LAPB_DEBUG > 1
printk(KERN_DEBUG "lapb: (%p) S1 TX SABM(1)\n", lapb->token);
#endif
lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
}
}
break;
/*
* Awaiting disconnection state, send DISC, up to N2 times.
*/
case LAPB_STATE_2:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb->t2timer = 0;
lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->token);
#endif
} else {
lapb->n2count++;
#if LAPB_DEBUG > 1
printk(KERN_DEBUG "lapb: (%p) S2 TX DISC(1)\n", lapb->token);
#endif
lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
}
break;
/*
* Data transfer state, restransmit I frames, up to N2 times.
*/
case LAPB_STATE_3:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb->t2timer = 0;
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->token);
#endif
} else {
lapb->n2count++;
lapb_requeue_frames(lapb);
}
break;
/*
* Frame reject state, restransmit FRMR frames, up to N2 times.
*/
case LAPB_STATE_4:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb->t2timer = 0;
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S4 -> S0\n", lapb->token);
#endif
} else {
lapb->n2count++;
lapb_transmit_frmr(lapb);
}
break;
}
lapb->t1timer = lapb->t1;
lapb_set_timer(lapb);
}
#endif
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