/* File : timer.c  - pc timer handler    */

/*
    Copyright (C) 1992 Indian Institute of Technology, Bombay
    Written by V. Srinivas and Vishwas Joglekar,
    Dept of Computer Science and Engineering.

    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 1, or (at your option)
    any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/



#define  TIMER_INT	0x1c
#include <dos.h>
#include <time.h>
#include "yapcbr.h"
#include "ipxwatch.h"
#include "ipxrip.h"
#include "sap.h"
#include "diag.h"

extern ROUT_TABLE *rip_lookup[];
extern struct sap_tbl *sap_lookup[];
extern int send_diag;
extern  struct network_info *current_net, *pred_net;
extern struct time t;
WORD ticks = 200;
WORD sec=0;
void interrupt (*old_clock_handler)();
void interrupt clock_tick();
void flush_rip_table();
void flush_sap_table();
void flush_node_table(struct network_info *net);

/* this handler is invoked for every clock tick   */

	void interrupt clock_tick()
	{
	  ticks = ticks-1;
	  if(ticks == 0){
	     ticks = 200;
	     sec+=10;
	     if(sec == DIAG_TX_INTERVAL){
		send_diag = TRUE;
		/* flag to indicate that the  diagnostic configuration request packets are to be sent */
		sec = 0;
	       /* decrement the elapsed time entries  in the sap and rip table */
		flush_sap_table();
		flush_rip_table();
		flush_node_table(current_net);
		flush_node_table(pred_net);
	     }
	     old_clock_handler();
	  }
       }

  void init_timer()
  {
  old_clock_handler = getvect(TIMER_INT);
  setvect(TIMER_INT,clock_tick);
  }

  void release_timer()
  {
  setvect(TIMER_INT,old_clock_handler);
  }

/* decrement the age_timer on every clock tick */
int l;
ROUT_TABLE *rip_ptr,*old_ptr,*tmp;

void flush_rip_table()
{
  for(l=0;l< MAX_PRIME;l++){
      rip_ptr = rip_lookup[l];
      for(rip_ptr=rip_lookup[l];rip_ptr!=0;rip_ptr=rip_ptr->next){
	  old_ptr = rip_ptr;
	  if(rip_ptr->route_info.no_of_hops > 0)
	      rip_ptr->age_timer -=10;
	  if(rip_ptr->age_timer <= 0 && rip_ptr->route_info.no_of_hops >0){ /* delete the entry from the table */
	     if(rip_ptr->alternate_route == 0){
		if(rip_ptr == rip_lookup[l]){
		   rip_lookup[l] = rip_ptr->next;
		   ibuf_free(rip_ptr,NOVLRIP);/* return the freed buffer to the buffer pool */
		 }
		else{
		   old_ptr->next = rip_ptr->next;
		   ibuf_free(rip_ptr,NOVLRIP);
		   continue;
		}
	       }
	     else{ /* if there is an alternate route */
		if(rip_ptr == rip_lookup[l]){
		    rip_lookup[l] = rip_ptr->alternate_route;
		    ibuf_free(rip_ptr,NOVLRIP);
		 }
		else{
		   old_ptr->next = rip_ptr->alternate_route;
		   rip_ptr->alternate_route->next = rip_ptr->next;
		   ibuf_free(rip_ptr,NOVLRIP);
		   continue;
		}
	     }
	 }
	  else {
		 if(rip_ptr->alternate_route != 0 && rip_ptr->route_info.no_of_hops>0){
		     rip_ptr->alternate_route->age_timer -=10;
		     if(rip_ptr->alternate_route->age_timer == 0){
			ibuf_free(rip_ptr->alternate_route,NOVLRIP);
			 rip_ptr->alternate_route =0;
		      }
		  }
	      }
	 old_ptr = rip_ptr;
    } /* for */
 } /* for */
}



/* decrement the timer entries in the server information table */
int k,serv_count=0,temp;
struct sap_tbl *tsap_ptr,*tmp_ptr;

void flush_sap_table()
{

for(k=0;k< MAX_PRIME;k++){
   for(tsap_ptr = sap_lookup[k]; tsap_ptr != NULLHPTR;tsap_ptr = tsap_ptr->next){
      tmp_ptr = tsap_ptr;
      tsap_ptr->elapsed_time -=10;
      if(tsap_ptr->elapsed_time <= (WORD) 0){ /* delete entry from the table */
	 if(tsap_ptr == sap_lookup[k]){
	    sap_lookup[k] = tsap_ptr->next;
	    ibuf_free(tsap_ptr,NOVLSAP);
	 }
	 else{
	    tmp_ptr->next = tsap_ptr->next;
	    ibuf_free(tsap_ptr,NOVLSAP);
#ifdef TDEBUG
	    printf("\n Timer expired, sap table entry deleted \n");
#endif
	    continue;
	   }
    }
  } /* for */
 } /* for */
}

/* decrement the timer entries in the node information table for the current
   network
*/
int ii;
NODE_INFO *cnode;

void flush_node_table(struct network_info *net)
{

if(net == 0)  return;
for(ii=0;ii<MAX_PRIME;ii++){
 cnode=net->node_info.node_info_table[ii].head;
 while(cnode!=0){
    if(cnode->clock_ticks >0){
	 cnode->clock_ticks -=10;
	if(cnode->clock_ticks == 0 && cnode->status == ACTIVE){
	   cnode->status = INACTIVE;
	   memcpy(&cnode->down_time,&t,sizeof(t)); /* save the current time */
	 }
    }
    cnode = cnode->next;
 }
}
}