/*
 * IS-IS Rout(e)ing protocol - isis_events.h   
 *
 * Copyright (C) 2001,2002   Sampo Saaristo
 *                           Tampere University of Technology      
 *                           Institute of Communications Engineering
 *
 * This program is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU General Public Licenseas published by the Free 
 * Software Foundation; either version 2 of the License, 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., 
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
#include <zebra.h>

#include "log.h"
#include "memory.h"
#include "if.h"
#include "linklist.h"
#include "command.h"
#include "thread.h"
#include "hash.h"
#include "prefix.h"
#include "stream.h"
#include "table.h"

#include "isisd/dict.h"
#include "isisd/include-netbsd/iso.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_common.h"
#include "isisd/isis_flags.h"
#include "isisd/isis_circuit.h"
#include "isisd/isis_tlv.h"
#include "isisd/isis_lsp.h"
#include "isisd/isis_pdu.h"
#include "isisd/isis_network.h"
#include "isisd/isis_misc.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_dr.h"
#include "isisd/isisd.h"
#include "isisd/isis_csm.h"
#include "isisd/isis_events.h"
#include "isisd/isis_spf.h"

/* debug isis-spf spf-events 
 4w4d: ISIS-Spf (tlt): L2 SPF needed, new adjacency, from 0x609229F4
 4w4d: ISIS-Spf (tlt): L2, 0000.0000.0042.01-00 TLV contents changed, code 0x2
 4w4d: ISIS-Spf (tlt): L2, new LSP 0 DEAD.BEEF.0043.00-00
 4w5d: ISIS-Spf (tlt): L1 SPF needed, periodic SPF, from 0x6091C844
 4w5d: ISIS-Spf (tlt): L2 SPF needed, periodic SPF, from 0x6091C844
*/

void
isis_event_circuit_state_change (struct isis_circuit *circuit,
                                 struct isis_area *area, int up)
{
  area->circuit_state_changes++;

  if (isis->debugs & DEBUG_EVENTS)
    zlog_debug ("ISIS-Evt (%s) circuit %s", area->area_tag,
                up ? "up" : "down");

  /*
   * Regenerate LSPs this affects
   */
  lsp_regenerate_schedule (area, IS_LEVEL_1 | IS_LEVEL_2, 0);

  return;
}

static void
area_resign_level (struct isis_area *area, int level)
{
  if (area->lspdb[level - 1])
    {
      lsp_db_destroy (area->lspdb[level - 1]);
      area->lspdb[level - 1] = NULL;
    }
  if (area->spftree[level - 1])
    {
      isis_spftree_del (area->spftree[level - 1]);
      area->spftree[level - 1] = NULL;
    }
#ifdef HAVE_IPV6
  if (area->spftree6[level - 1])
    {
      isis_spftree_del (area->spftree6[level - 1]);
      area->spftree6[level - 1] = NULL;
    }
#endif
  if (area->route_table[level - 1])
    {
      route_table_finish (area->route_table[level - 1]);
      area->route_table[level - 1] = NULL;
    }
#ifdef HAVE_IPV6
  if (area->route_table6[level - 1])
    {
      route_table_finish (area->route_table6[level - 1]);
      area->route_table6[level - 1] = NULL;
    }
#endif /* HAVE_IPV6 */

  sched_debug("ISIS (%s): Resigned from L%d - canceling LSP regeneration timer.",
              area->area_tag, level);
  THREAD_TIMER_OFF (area->t_lsp_refresh[level - 1]);
  area->lsp_regenerate_pending[level - 1] = 0;
}

void
isis_event_system_type_change (struct isis_area *area, int newtype)
{
  struct listnode *node;
  struct isis_circuit *circuit;

  if (isis->debugs & DEBUG_EVENTS)
    zlog_debug ("ISIS-Evt (%s) system type change %s -> %s", area->area_tag,
	       circuit_t2string (area->is_type), circuit_t2string (newtype));

  if (area->is_type == newtype)
    return;			/* No change */

  switch (area->is_type)
  {
    case IS_LEVEL_1:
      if (newtype == IS_LEVEL_2)
        area_resign_level (area, IS_LEVEL_1);

      if (area->lspdb[1] == NULL)
        area->lspdb[1] = lsp_db_init ();
      if (area->route_table[1] == NULL)
        area->route_table[1] = route_table_init ();
#ifdef HAVE_IPV6
      if (area->route_table6[1] == NULL)
        area->route_table6[1] = route_table_init ();
#endif /* HAVE_IPV6 */
      break;

    case IS_LEVEL_1_AND_2:
      if (newtype == IS_LEVEL_1)
        area_resign_level (area, IS_LEVEL_2);
      else
        area_resign_level (area, IS_LEVEL_1);
      break;

    case IS_LEVEL_2:
      if (newtype == IS_LEVEL_1)
        area_resign_level (area, IS_LEVEL_2);

      if (area->lspdb[0] == NULL)
        area->lspdb[0] = lsp_db_init ();
      if (area->route_table[0] == NULL)
        area->route_table[0] = route_table_init ();
#ifdef HAVE_IPV6
      if (area->route_table6[0] == NULL)
        area->route_table6[0] = route_table_init ();
#endif /* HAVE_IPV6 */
      break;

    default:
      break;
  }

  area->is_type = newtype;

  /* override circuit's is_type */
  if (area->is_type != IS_LEVEL_1_AND_2)
  {
    for (ALL_LIST_ELEMENTS_RO (area->circuit_list, node, circuit))
      isis_event_circuit_type_change (circuit, newtype);
  }

  spftree_area_init (area);

  if (newtype & IS_LEVEL_1)
    lsp_generate (area, IS_LEVEL_1);
  if (newtype & IS_LEVEL_2)
    lsp_generate (area, IS_LEVEL_2);
  lsp_regenerate_schedule (area, IS_LEVEL_1 | IS_LEVEL_2, 1);

  return;
}

static void
circuit_commence_level (struct isis_circuit *circuit, int level)
{
  if (level == 1)
    {
      if (! circuit->is_passive)
        THREAD_TIMER_ON (master, circuit->t_send_psnp[0], send_l1_psnp, circuit,
		         isis_jitter (circuit->psnp_interval[0], PSNP_JITTER));

      if (circuit->circ_type == CIRCUIT_T_BROADCAST)
	{
	  THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[0], isis_run_dr_l1,
			   circuit, 2 * circuit->hello_interval[0]);

	  THREAD_TIMER_ON (master, circuit->u.bc.t_send_lan_hello[0],
			   send_lan_l1_hello, circuit,
			   isis_jitter (circuit->hello_interval[0],
					IIH_JITTER));

	  circuit->u.bc.lan_neighs[0] = list_new ();
	}
    }
  else
    {
      if (! circuit->is_passive)
        THREAD_TIMER_ON (master, circuit->t_send_psnp[1], send_l2_psnp, circuit,
		         isis_jitter (circuit->psnp_interval[1], PSNP_JITTER));

      if (circuit->circ_type == CIRCUIT_T_BROADCAST)
	{
	  THREAD_TIMER_ON (master, circuit->u.bc.t_run_dr[1], isis_run_dr_l2,
			   circuit, 2 * circuit->hello_interval[1]);

	  THREAD_TIMER_ON (master, circuit->u.bc.t_send_lan_hello[1],
			   send_lan_l2_hello, circuit,
			   isis_jitter (circuit->hello_interval[1],
					IIH_JITTER));

	  circuit->u.bc.lan_neighs[1] = list_new ();
	}
    }

  return;
}

static void
circuit_resign_level (struct isis_circuit *circuit, int level)
{
  int idx = level - 1;

  THREAD_TIMER_OFF (circuit->t_send_csnp[idx]);
  THREAD_TIMER_OFF (circuit->t_send_psnp[idx]);

  if (circuit->circ_type == CIRCUIT_T_BROADCAST)
    {
      THREAD_TIMER_OFF (circuit->u.bc.t_send_lan_hello[idx]);
      THREAD_TIMER_OFF (circuit->u.bc.t_run_dr[idx]);
      THREAD_TIMER_OFF (circuit->u.bc.t_refresh_pseudo_lsp[idx]);
      circuit->lsp_regenerate_pending[idx] = 0;
      circuit->u.bc.run_dr_elect[idx] = 0;
      if (circuit->u.bc.lan_neighs[idx] != NULL) {
        list_delete (circuit->u.bc.lan_neighs[idx]);
        circuit->u.bc.lan_neighs[idx] = NULL;
      }
    }

  return;
}

void
isis_event_circuit_type_change (struct isis_circuit *circuit, int newtype)
{
  if (circuit->state != C_STATE_UP)
  {
    circuit->is_type = newtype;
    return;
  }

  if (isis->debugs & DEBUG_EVENTS)
    zlog_debug ("ISIS-Evt (%s) circuit type change %s -> %s",
	       circuit->area->area_tag,
	       circuit_t2string (circuit->is_type),
	       circuit_t2string (newtype));

  if (circuit->is_type == newtype)
    return;			/* No change */

  if (!(newtype & circuit->area->is_type))
    {
      zlog_err ("ISIS-Evt (%s) circuit type change - invalid level %s because"
		" area is %s", circuit->area->area_tag,
		circuit_t2string (newtype),
		circuit_t2string (circuit->area->is_type));
      return;
    }

  if (! circuit->is_passive)
    {
      switch (circuit->is_type)
        {
        case IS_LEVEL_1:
          if (newtype == IS_LEVEL_2)
            circuit_resign_level (circuit, 1);
          circuit_commence_level (circuit, 2);
          break;
        case IS_LEVEL_1_AND_2:
          if (newtype == IS_LEVEL_1)
            circuit_resign_level (circuit, 2);
          else
            circuit_resign_level (circuit, 1);
          break;
        case IS_LEVEL_2:
          if (newtype == IS_LEVEL_1)
            circuit_resign_level (circuit, 2);
          circuit_commence_level (circuit, 1);
          break;
        default:
          break;
        }
    }

  circuit->is_type = newtype;
  lsp_regenerate_schedule (circuit->area, IS_LEVEL_1 | IS_LEVEL_2, 0);

  return;
}

 /* 04/18/2002 by Gwak. */
 /**************************************************************************
  *
  * EVENTS for LSP generation
  *
  * 1) an Adajacency or Circuit Up/Down event
  * 2) a chnage in Circuit metric
  * 3) a change in Reachable Address metric
  * 4) a change in manualAreaAddresses
  * 5) a change in systemID
  * 6) a change in DIS status
  * 7) a chnage in the waiting status
  *
  * ***********************************************************************
  *
  * current support event
  *
  * 1) Adjacency Up/Down event
  * 6) a change in DIS status
  *
  * ***********************************************************************/

void
isis_event_adjacency_state_change (struct isis_adjacency *adj, int newstate)
{
  /* adjacency state change event. 
   * - the only proto-type was supported */

  /* invalid arguments */
  if (!adj || !adj->circuit || !adj->circuit->area)
    return;

  if (isis->debugs & DEBUG_EVENTS)
    zlog_debug ("ISIS-Evt (%s) Adjacency State change",
		adj->circuit->area->area_tag);

  /* LSP generation again */
  lsp_regenerate_schedule (adj->circuit->area, IS_LEVEL_1 | IS_LEVEL_2, 0);

  return;
}

/* events supporting code */

int
isis_event_dis_status_change (struct thread *thread)
{
  struct isis_circuit *circuit;

  circuit = THREAD_ARG (thread);

  /* invalid arguments */
  if (!circuit || !circuit->area)
    return 0;
  if (isis->debugs & DEBUG_EVENTS)
    zlog_debug ("ISIS-Evt (%s) DIS status change", circuit->area->area_tag);

  /* LSP generation again */
  lsp_regenerate_schedule (circuit->area, IS_LEVEL_1 | IS_LEVEL_2, 0);

  return 0;
}

void
isis_event_auth_failure (char *area_tag, const char *error_string, u_char *sysid)
{
  if (isis->debugs & DEBUG_EVENTS)
    zlog_debug ("ISIS-Evt (%s) Authentication failure %s from %s",
		area_tag, error_string, sysid_print (sysid));

  return;
}