/*
 * IS-IS Rout(e)ing protocol - isis_adjacency.c   
 *                             handling of IS-IS adjacencies
 *
 * 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 <stdio.h>
#include <limits.h>
#include <string.h>
#include <zebra.h>

#include "log.h"
#include "memory.h"
#include "hash.h"
#include "vty.h"
#include "linklist.h"
#include "thread.h"
#include "if.h"
#include "stream.h"

#include "isisd/dict.h"
#include "isisd/include-netbsd/iso.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_common.h"
#include "isisd/isisd.h"
#include "isisd/isis_circuit.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_misc.h"
#include "isisd/isis_dr.h"
#include "isisd/isis_dynhn.h"
#include "isisd/isis_pdu.h"


extern struct isis *isis;


struct isis_adjacency *
adj_alloc (u_char *id)
{
    struct isis_adjacency *adj;

    adj = XMALLOC (MTYPE_ISIS_ADJACENCY, sizeof (struct isis_adjacency));
    memset (adj, 0, sizeof (struct isis_adjacency));
    memcpy (adj->sysid, id, ISIS_SYS_ID_LEN);
    
    return adj;
}

struct isis_adjacency *
isis_new_adj (u_char *id, u_char *snpa, int level, 
	      struct isis_circuit *circuit)
{

  struct isis_adjacency *adj;
  int i;  

  adj = adj_alloc (id); /* P2P kludge */
  
  if (adj == NULL){
    zlog_err ("Out of memory!");
    return NULL;
  }

  memcpy (adj->snpa, snpa, 6);
  adj->circuit = circuit;
  adj->level = level;
  adj->flaps = 0;
  adj->last_flap = time (NULL);
  if (circuit->circ_type == CIRCUIT_T_BROADCAST) {
    listnode_add (circuit->u.bc.adjdb[level-1], adj);
    adj->dischanges[level - 1] = 0;
    for (i = 0; i < DIS_RECORDS; i++) /* clear N DIS state change records */
	{
	  adj->dis_record[(i * ISIS_LEVELS) + level - 1].dis 
	    = ISIS_UNKNOWN_DIS;
	  adj->dis_record[(i * ISIS_LEVELS) + level - 1].last_dis_change 
            = time (NULL);
	}
  }

  return adj;
}

struct isis_adjacency *
isis_adj_lookup (u_char *sysid,  struct list *adjdb)
{
  struct isis_adjacency *adj;
  struct listnode *node;

  for (node = listhead (adjdb); node; nextnode (node)) {
    adj = getdata (node);
    if (memcmp (adj->sysid, sysid, ISIS_SYS_ID_LEN) == 0)
      return adj;
  }
  
  return NULL;
}


struct isis_adjacency *
isis_adj_lookup_snpa (u_char *ssnpa, struct list *adjdb)
{
  struct listnode *node;
  struct isis_adjacency *adj;

  for (node = listhead (adjdb); node; nextnode (node)) {
    adj = getdata (node);
    if (memcmp (adj->snpa, ssnpa, ETH_ALEN) == 0)
      return adj;
  }
  
  return NULL;
}

/*
 * When we recieve a NULL list, we will know its p2p
 */
void 
isis_delete_adj (struct isis_adjacency *adj, struct list *adjdb)
{
  struct isis_adjacency *adj2;
  struct listnode *node;
  
  if (adjdb) {
    for (node = listhead (adjdb); node; nextnode (node)) {
      adj2 = getdata (node);
      if (adj2 == adj)
        break;
    }
    listnode_delete (adjdb, adj);
  }
  
  if (adj->ipv4_addrs)
    list_delete (adj->ipv4_addrs);
#ifdef HAVE_IPV6
  if (adj->ipv6_addrs)
    list_delete (adj->ipv6_addrs);
#endif
  if (adj) {
    XFREE (MTYPE_ISIS_ADJACENCY,adj);
  } else {
    zlog_info ("tried to delete a non-existent adjacency");
  }
  
  
  return;
}

void 
isis_adj_state_change (struct isis_adjacency *adj, enum isis_adj_state state, 
                       char *reason)

{
  int old_state;
  int level = adj->level;
  struct isis_circuit *circuit;
  
  old_state = adj->adj_state;
  adj->adj_state = state;

  circuit = adj->circuit;
  
  if (isis->debugs & DEBUG_ADJ_PACKETS) {
    zlog_info ("ISIS-Adj (%s): Adjacency state change %d->%d: %s",
               circuit->area->area_tag,
               old_state,
               state, 
               reason ? reason : "unspecified");
  }

  if (circuit->circ_type == CIRCUIT_T_BROADCAST) {
    if (state == ISIS_ADJ_UP)
      circuit->upadjcount[level-1]++;
    if (state == ISIS_ADJ_DOWN) {
      isis_delete_adj (adj, adj->circuit->u.bc.adjdb[level - 1]);
      circuit->upadjcount[level-1]--;
    }

    list_delete_all_node (circuit->u.bc.lan_neighs[level - 1]);
    isis_adj_build_neigh_list (circuit->u.bc.adjdb[level - 1],
                               circuit->u.bc.lan_neighs[level - 1]);
  } else if (state == ISIS_ADJ_UP) { /* p2p interface */
    if (adj->sys_type == ISIS_SYSTYPE_UNKNOWN)
      send_hello (circuit, 1);
    
    /* update counter & timers for debugging purposes */
    adj->last_flap = time(NULL);
    adj->flaps++;

    /* 7.3.17 - going up on P2P -> send CSNP */
    /* FIXME: yup, I know its wrong... but i will do it! (for now) */
    send_csnp (circuit,1);
    send_csnp (circuit,2);
  } else if (state == ISIS_ADJ_DOWN) { /* p2p interface */
    adj->circuit->u.p2p.neighbor = NULL;
    isis_delete_adj (adj, NULL);
  }
  return;
}


void
isis_adj_print (struct isis_adjacency *adj)
{
  struct isis_dynhn *dyn;
  struct listnode *node;
  struct in_addr *ipv4_addr;
#ifdef HAVE_IPV6 
  struct in6_addr *ipv6_addr;
  u_char ip6 [INET6_ADDRSTRLEN];
#endif /* HAVE_IPV6 */
  
  if(!adj)
    return;
  dyn = dynhn_find_by_id (adj->sysid);
  if (dyn)
    zlog_info ("%s", dyn->name.name);
  
  zlog_info ("SystemId %20s SNPA %s, level %d\nHolding Time %d",
             adj->sysid ? sysid_print (adj->sysid) : "unknown" , 
             snpa_print (adj->snpa),
             adj->level, adj->hold_time);
  if (adj->ipv4_addrs && listcount (adj->ipv4_addrs) > 0) {
    zlog_info ("IPv4 Addresses:");
    
    for (node = listhead (adj->ipv4_addrs); node; nextnode (node)) {
      ipv4_addr = getdata (node);
      zlog_info ("%s", inet_ntoa(*ipv4_addr));
    }
  }

#ifdef HAVE_IPV6  
  if (adj->ipv6_addrs && listcount (adj->ipv6_addrs) > 0) {
    zlog_info ("IPv6 Addresses:");
    for (node = listhead (adj->ipv6_addrs); node; nextnode (node)) {
      ipv6_addr = getdata (node);
      inet_ntop (AF_INET6, ipv6_addr, ip6, INET6_ADDRSTRLEN); 
      zlog_info ("%s", ip6);
    }
  }
#endif /* HAVE_IPV6 */
  zlog_info ("Speaks: %s", nlpid2string(&adj->nlpids));
  

  return;
}

int 
isis_adj_expire (struct thread *thread)
{
  struct isis_adjacency *adj;
  int level;

  /*
   * Get the adjacency
   */
  adj = THREAD_ARG (thread);
  assert (adj);
  level = adj->level;
  adj->t_expire = NULL;

  /* trigger the adj expire event */
  isis_adj_state_change (adj, ISIS_ADJ_DOWN, "holding time expired");

  return 0;
}

const char *
adj_state2string (int state)
{
  
  switch (state) {
  case ISIS_ADJ_INITIALIZING:
    return "Initializing";
  case ISIS_ADJ_UP:
    return "Up";
  case ISIS_ADJ_DOWN:
    return "Down";
  default:
    return "Unknown";
  }
  
  return NULL; /* not reached */
}

/*
 * show clns/isis neighbor (detail)
 */
void
isis_adj_print_vty2 (struct isis_adjacency *adj, struct vty *vty, char detail)
{

#ifdef HAVE_IPV6
  struct in6_addr *ipv6_addr;
  u_char ip6 [INET6_ADDRSTRLEN];
#endif /* HAVE_IPV6 */
  struct in_addr *ip_addr;
  time_t now;
  struct isis_dynhn *dyn;
  int level;
  struct listnode *node;

  dyn = dynhn_find_by_id (adj->sysid);
  if (dyn)
    vty_out (vty, "  %-20s", dyn->name.name);
  else if (adj->sysid){
    vty_out (vty, "  %-20s", sysid_print (adj->sysid));
  } else {
    vty_out (vty, "  unknown ");
  }

  if (detail == ISIS_UI_LEVEL_BRIEF) {
    if (adj->circuit)
      vty_out (vty, "%-12s",adj->circuit->interface->name); 
    else
      vty_out (vty, "NULL circuit!");
    vty_out (vty, "%-3u", adj->level); /* level */
    vty_out (vty, "%-13s", adj_state2string (adj->adj_state));
    now = time (NULL);
    if (adj->last_upd)
      vty_out (vty, "%-9lu", adj->last_upd + adj->hold_time - now);
    else
      vty_out (vty, "-        ");
    vty_out (vty, "%-10s", snpa_print (adj->snpa)); 
    vty_out (vty, "%s", VTY_NEWLINE);
  }

  if (detail == ISIS_UI_LEVEL_DETAIL) {
    level = adj->level;
    if (adj->circuit)
      vty_out (vty, "%s    Interface: %s",
               VTY_NEWLINE,
               adj->circuit->interface->name); /* interface name */
    else
      vty_out (vty, "NULL circuit!%s", VTY_NEWLINE);
    vty_out (vty, ", Level: %u", adj->level); /* level */
    vty_out (vty, ", State: %s", adj_state2string (adj->adj_state));
    now = time (NULL);
    if (adj->last_upd)
      vty_out (vty, ", Expires in %s", 
               time2string (adj->last_upd + adj->hold_time - now));
    else
      vty_out (vty, ", Expires in %s", 
               time2string (adj->hold_time));
    vty_out (vty, "%s    Adjacency flaps: %u",
	     VTY_NEWLINE,
	     adj->flaps);
    vty_out (vty, ", Last: %s ago", time2string(now - adj->last_flap));
    vty_out (vty, "%s    Circuit type: %s",
	     VTY_NEWLINE,
	     circuit_t2string(adj->circuit_t));
    vty_out (vty, ", Speaks: %s", nlpid2string(&adj->nlpids));
    vty_out (vty, "%s    SNPA: %s",
	     VTY_NEWLINE,
	     snpa_print (adj->snpa));   
    dyn = dynhn_find_by_id (adj->lanid);
    if (dyn)
      vty_out (vty, ", LAN id: %s.%02x",
	       dyn->name.name,
	       adj->lanid[ISIS_SYS_ID_LEN]);
    else 
      vty_out (vty, ", LAN id: %s.%02x",
	       sysid_print (adj->lanid),
	       adj->lanid[ISIS_SYS_ID_LEN]);
    
    vty_out (vty, "%s    Priority: %u",
	     VTY_NEWLINE,
	     adj->prio[adj->level-1]);

    vty_out (vty, ", %s, DIS flaps: %u, Last: %s ago%s",
	     isis_disflag2string(adj->dis_record[ISIS_LEVELS+level-1].dis),
	     adj->dischanges[level-1],
	     time2string (now - 
                   (adj->dis_record[ISIS_LEVELS + level - 1].last_dis_change)),
	     VTY_NEWLINE);    
             	
    if (adj->ipv4_addrs && listcount (adj->ipv4_addrs) > 0) {
      vty_out (vty, "    IPv4 Addresses:%s", VTY_NEWLINE);
      for (node = listhead (adj->ipv4_addrs);node; nextnode (node)) {
        ip_addr = getdata (node);
        vty_out (vty, "      %s%s", inet_ntoa(*ip_addr), VTY_NEWLINE);
      }
    }
#ifdef HAVE_IPV6  
    if (adj->ipv6_addrs && listcount (adj->ipv6_addrs) > 0) {
      vty_out (vty, "    IPv6 Addresses:%s", VTY_NEWLINE);
      for (node = listhead (adj->ipv6_addrs); node; nextnode (node)) {
        ipv6_addr = getdata (node);
        inet_ntop (AF_INET6, ipv6_addr, ip6, INET6_ADDRSTRLEN); 
        vty_out (vty, "      %s%s", ip6, VTY_NEWLINE);
      }
    }
#endif /* HAVE_IPV6 */
    vty_out (vty, "%s", VTY_NEWLINE);
  }
  return;
}

void
isis_adj_print_vty (struct isis_adjacency *adj, struct vty *vty) {
  isis_adj_print_vty2 (adj, vty, ISIS_UI_LEVEL_BRIEF);
}

void
isis_adj_print_vty_detail (struct isis_adjacency *adj, struct vty *vty) {
  isis_adj_print_vty2 (adj, vty, ISIS_UI_LEVEL_DETAIL);
}

void
isis_adj_print_vty_extensive (struct isis_adjacency *adj, struct vty *vty) {
  isis_adj_print_vty2 (adj, vty, ISIS_UI_LEVEL_EXTENSIVE);
}

void
isis_adj_p2p_print_vty (struct isis_adjacency *adj, struct vty *vty)
{
  isis_adj_print_vty2 (adj, vty, ISIS_UI_LEVEL_BRIEF);
}

void 
isis_adj_p2p_print_vty_detail (struct isis_adjacency *adj, struct vty *vty) 
{
  isis_adj_print_vty2 (adj, vty, ISIS_UI_LEVEL_DETAIL);
}

void 
isis_adj_p2p_print_vty_extensive (struct isis_adjacency *adj, struct vty *vty)
{
  isis_adj_print_vty2 (adj, vty, ISIS_UI_LEVEL_EXTENSIVE);
}

void
isis_adjdb_iterate (struct list *adjdb, void (*func)(struct isis_adjacency*, 
                                                 void *), void *arg)
{
  struct listnode *node;
  struct isis_adjacency *adj;
  for (node = listhead (adjdb); node; nextnode (node)) {
    adj = getdata (node);
    (*func)(adj, arg);
  }
}

void
isis_adj_build_neigh_list (struct list *adjdb, struct list *list)

{
  struct isis_adjacency *adj;
  struct listnode *node;
  
  
  if (!list) {
    zlog_warn ("isis_adj_build_neigh_list(): NULL list");
    return;
  }
  
  for (node = listhead (adjdb); node; nextnode (node)) {
    adj = getdata (node);
    if (!adj) {
      zlog_warn ("isis_adj_build_neigh_list(): NULL adj");
      return;
    }
  
    if ((adj->adj_state == ISIS_ADJ_UP || 
       adj->adj_state == ISIS_ADJ_INITIALIZING))
      listnode_add (list, adj->snpa);
  }
  return;
}

void
isis_adj_build_up_list (struct list *adjdb, struct list *list)
{
  struct isis_adjacency *adj;
  struct listnode *node;

  if (!list) {
    zlog_warn ("isis_adj_build_up_list(): NULL list");
    return;
  }

  for (node = listhead (adjdb); node; nextnode (node)) {
    adj = getdata (node);
    
    if (!adj) {
      zlog_warn ("isis_adj_build_up_list(): NULL adj");
      return;
    }

    if (adj->adj_state == ISIS_ADJ_UP)
      listnode_add (list, adj);
  }
  
  return;
}