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/*
* AX.25 release 036
*
* 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
* AX.25 028a Jonathan(G4KLX) New state machine based on SDL diagrams.
* AX.25 028b Jonathan(G4KLX) Extracted AX25 control block from the
* sock structure.
* AX.25 029 Alan(GW4PTS) Switched to KA9Q constant names.
* AX.25 031 Joerg(DL1BKE) Added DAMA support
* AX.25 032 Joerg(DL1BKE) Fixed DAMA timeout bug
* AX.25 033 Jonathan(G4KLX) Modularisation functions.
* AX.25 035 Frederic(F1OAT) Support for pseudo-digipeating.
* AX.25 036 Jonathan(G4KLX) Split from ax25_timer.c.
*/
#include <linux/config.h>
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_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 <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.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>
void ax25_std_timer(ax25_cb *ax25)
{
switch (ax25->state) {
case AX25_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 (ax25->sk == NULL || ax25->sk->destroy || (ax25->sk->state == TCP_LISTEN && ax25->sk->dead)) {
del_timer(&ax25->timer);
ax25_destroy_socket(ax25);
return;
}
break;
case AX25_STATE_3:
case AX25_STATE_4:
/*
* Check the state of the receive buffer.
*/
if (ax25->sk != NULL) {
if (atomic_read(&ax25->sk->rmem_alloc) < (ax25->sk->rcvbuf / 2) &&
(ax25->condition & AX25_COND_OWN_RX_BUSY)) {
ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
ax25->condition &= ~AX25_COND_ACK_PENDING;
ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
break;
}
}
/*
* Check for frames to transmit.
*/
ax25_kick(ax25);
break;
default:
break;
}
if (ax25->t2timer > 0 && --ax25->t2timer == 0) {
if (ax25->state == AX25_STATE_3 || ax25->state == AX25_STATE_4) {
if (ax25->condition & AX25_COND_ACK_PENDING) {
ax25->condition &= ~AX25_COND_ACK_PENDING;
ax25_std_timeout_response(ax25);
}
}
}
if (ax25->t3timer > 0 && --ax25->t3timer == 0) {
if (ax25->state == AX25_STATE_3) {
ax25->n2count = 0;
ax25_std_transmit_enquiry(ax25);
ax25->state = AX25_STATE_4;
}
ax25->t3timer = ax25->t3;
}
if (ax25->idletimer > 0 && --ax25->idletimer == 0) {
/* dl1bke 960228: close the connection when IDLE expires */
/* similar to DAMA T3 timeout but with */
/* a "clean" disconnect of the connection */
ax25_clear_queues(ax25);
ax25->n2count = 0;
ax25->t3timer = 0;
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
ax25->state = AX25_STATE_2;
ax25->t1timer = ax25->t1 = ax25_calculate_t1(ax25);
if (ax25->sk != NULL) {
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = 0;
ax25->sk->shutdown |= SEND_SHUTDOWN;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
ax25->sk->destroy = 1;
}
}
if (ax25->t1timer == 0 || --ax25->t1timer > 0) {
ax25_set_timer(ax25);
return;
}
switch (ax25->state) {
case AX25_STATE_1:
if (ax25->n2count == ax25->n2) {
if (ax25->modulus == AX25_MODULUS) {
ax25_link_failed(&ax25->dest_addr, ax25->ax25_dev->dev);
ax25_clear_queues(ax25);
ax25->state = AX25_STATE_0;
if (ax25->sk != NULL) {
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = ETIMEDOUT;
ax25->sk->shutdown |= SEND_SHUTDOWN;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
}
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
ax25->n2count = 0;
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
}
} else {
ax25->n2count++;
if (ax25->modulus == AX25_MODULUS)
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
else
ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_2:
if (ax25->n2count == ax25->n2) {
ax25_link_failed(&ax25->dest_addr, ax25->ax25_dev->dev);
ax25_clear_queues(ax25);
ax25->state = AX25_STATE_0;
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
if (ax25->sk != NULL) {
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = ETIMEDOUT;
ax25->sk->shutdown |= SEND_SHUTDOWN;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
}
} else {
ax25->n2count++;
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_3:
ax25->n2count = 1;
ax25_std_transmit_enquiry(ax25);
ax25->state = AX25_STATE_4;
break;
case AX25_STATE_4:
if (ax25->n2count == ax25->n2) {
ax25_link_failed(&ax25->dest_addr, ax25->ax25_dev->dev);
ax25_clear_queues(ax25);
ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
ax25->state = AX25_STATE_0;
if (ax25->sk != NULL) {
SOCK_DEBUG(ax25->sk, "AX.25 link Failure\n");
ax25->sk->state = TCP_CLOSE;
ax25->sk->err = ETIMEDOUT;
ax25->sk->shutdown |= SEND_SHUTDOWN;
if (!ax25->sk->dead)
ax25->sk->state_change(ax25->sk);
ax25->sk->dead = 1;
}
} else {
ax25->n2count++;
ax25_std_transmit_enquiry(ax25);
}
break;
}
ax25->t1timer = ax25->t1 = ax25_calculate_t1(ax25);
ax25_set_timer(ax25);
}
#endif
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