text: /*
   *	LAPB release 002
   *
   *	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
   *	LAPB 002	Jonathan Naylor	New timer architecture.
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/socket.h>
  #include <linux/in.h>
  #include <linux/kernel.h>
  #include <linux/jiffies.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 <linux/fcntl.h>
  #include <linux/mm.h>
  #include <linux/interrupt.h>
  #include <net/lapb.h>
  
  static void lapb_t1timer_expiry(unsigned long);
  static void lapb_t2timer_expiry(unsigned long);
  
  void lapb_start_t1timer(struct lapb_cb *lapb)
  {
  	del_timer(&lapb->t1timer);
  
  	lapb->t1timer.data     = (unsigned long)lapb;
  	lapb->t1timer.function = &lapb_t1timer_expiry;
  	lapb->t1timer.expires  = jiffies + lapb->t1;
  
  	add_timer(&lapb->t1timer);
  }
  
  void lapb_start_t2timer(struct lapb_cb *lapb)
  {
  	del_timer(&lapb->t2timer);
  
  	lapb->t2timer.data     = (unsigned long)lapb;
  	lapb->t2timer.function = &lapb_t2timer_expiry;
  	lapb->t2timer.expires  = jiffies + lapb->t2;
  
  	add_timer(&lapb->t2timer);
  }
  
  void lapb_stop_t1timer(struct lapb_cb *lapb)
  {
  	del_timer(&lapb->t1timer);
  }
  
  void lapb_stop_t2timer(struct lapb_cb *lapb)
  {
  	del_timer(&lapb->t2timer);
  }
  
  int lapb_t1timer_running(struct lapb_cb *lapb)
  {
  	return timer_pending(&lapb->t1timer);
  }
  
  static void lapb_t2timer_expiry(unsigned long param)
  {
  	struct lapb_cb *lapb = (struct lapb_cb *)param;
  
  	if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
  		lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
  		lapb_timeout_response(lapb);
  	}
  }
  
  static void lapb_t1timer_expiry(unsigned long param)
  {
  	struct lapb_cb *lapb = (struct lapb_cb *)param;
  
  	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_disconnect_indication(lapb, LAPB_TIMEDOUT);
  				lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
  				return;
  			} else {
  				lapb->n2count++;
  				if (lapb->mode & LAPB_EXTENDED) {
  					lapb_dbg(1, "(%p) S1 TX SABME(1)\n",
  						 lapb->dev);
  					lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
  				} else {
  					lapb_dbg(1, "(%p) S1 TX SABM(1)\n",
  						 lapb->dev);
  					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_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
  				lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
  				return;
  			} else {
  				lapb->n2count++;
  				lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev);
  				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_stop_t2timer(lapb);
  				lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
  				lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
  				return;
  			} else {
  				lapb->n2count++;
  				lapb_requeue_frames(lapb);
  				lapb_kick(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_disconnect_indication(lapb, LAPB_TIMEDOUT);
  				lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev);
  				return;
  			} else {
  				lapb->n2count++;
  				lapb_transmit_frmr(lapb);
  			}
  			break;
  	}
  
  	lapb_start_t1timer(lapb);
  }
  