/*
 * IS-IS Rout(e)ing protocol               - isis_route.c
 * Copyright (C) 2001,2002   Sampo Saaristo
 *                           Tampere University of Technology      
 *                           Institute of Communications Engineering
 *
 *                                         based on ../ospf6d/ospf6_route.[ch]
 *                                         by Yasuhiro Ohara
 *
 * 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 <stdlib.h>
#include <stdio.h>
#include <zebra.h>

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

#include "isis_constants.h"
#include "isis_common.h"
#include "dict.h"
#include "isisd.h"
#include "isis_misc.h"
#include "isis_adjacency.h"
#include "isis_circuit.h"
#include "isis_tlv.h"
#include "isis_pdu.h"
#include "isis_lsp.h"
#include "isis_spf.h"
#include "isis_route.h"
#include "isis_zebra.h"

extern struct isis *isis;
extern struct thread_master *master;

struct isis_nexthop *
isis_nexthop_create (struct in_addr *ip, unsigned int ifindex)
                     
{
  struct listnode *node;
  struct isis_nexthop *nexthop;
  
  for (node = listhead (isis->nexthops); node; nextnode (node)) {
    nexthop = getdata (node);
    if (nexthop->ifindex != ifindex)
      continue;
    if (ip && memcmp (&nexthop->ip, ip, sizeof (struct in_addr)) != 0)
      continue; 

    nexthop->lock++;
    return nexthop;
  }
  
  nexthop = XMALLOC (MTYPE_ISIS_NEXTHOP, sizeof (struct isis_nexthop));
  if (!nexthop) {
    zlog_err ("ISIS-Rte: isis_nexthop_create: out of memory!");
  }
  
  memset (nexthop, 0, sizeof (struct isis_nexthop));
  nexthop->ifindex = ifindex;
  memcpy (&nexthop->ip, ip, sizeof (struct in_addr));
  listnode_add (isis->nexthops, nexthop);
  nexthop->lock++;

  return nexthop;
}


void
isis_nexthop_delete (struct isis_nexthop *nexthop)
{
  nexthop->lock--;
  if (nexthop->lock == 0) {
    listnode_delete (isis->nexthops, nexthop);
    XFREE (MTYPE_ISIS_NEXTHOP, nexthop);
  }
    
  return;
}

int
nexthoplookup (struct list *nexthops, struct in_addr *ip, 
               unsigned int ifindex)
{
  struct listnode *node;
  struct isis_nexthop *nh;

  for (node = listhead (nexthops); node; nextnode (node)) {
    nh = getdata (node);
    if (!(memcmp (ip, &nh->ip, sizeof (struct in_addr))) && 
        ifindex == nh->ifindex)
      return 1;
  }

  return 0;
}

void
nexthop_print (struct isis_nexthop *nh)
{
  u_char buf[BUFSIZ];
  
  inet_ntop (AF_INET, &nh->ip, buf, BUFSIZ);
  
  zlog_info ("      %s %u", buf, nh->ifindex);
}

void
nexthops_print (struct list *nhs)
{
  struct listnode *node;
  
  for (node = listhead(nhs); node; nextnode (node))
    nexthop_print (getdata (node));
}

#ifdef HAVE_IPV6

struct isis_nexthop6 *
isis_nexthop6_new (struct in6_addr *ip6, unsigned int ifindex) 
{
  
  struct isis_nexthop6 *nexthop6;
  
  nexthop6 = XMALLOC (MTYPE_ISIS_NEXTHOP6, sizeof (struct isis_nexthop6));
  if (!nexthop6) {
    zlog_err ("ISIS-Rte: isis_nexthop_create6: out of memory!");
  }
  
  memset (nexthop6, 0, sizeof (struct isis_nexthop6));
  nexthop6->ifindex = ifindex;
  memcpy (&nexthop6->ip6, ip6, sizeof (struct in6_addr));
  nexthop6->lock++;

  return nexthop6;
}

struct isis_nexthop6 *
isis_nexthop6_create (struct in6_addr *ip6, unsigned int ifindex)
                     
{
  struct listnode *node;
  struct isis_nexthop6 *nexthop6;
  
  for (node = listhead (isis->nexthops6); node; nextnode (node)) {
    nexthop6 = getdata (node);
    if (nexthop6->ifindex != ifindex)
      continue;
    if (ip6 && memcmp (&nexthop6->ip6, ip6, sizeof (struct in6_addr)) != 0)
      continue; 

    nexthop6->lock++;
    return nexthop6;
  }
  
  nexthop6 = isis_nexthop6_new (ip6, ifindex);

  return nexthop6;
}


void
isis_nexthop6_delete (struct isis_nexthop6 *nexthop6)
{

  nexthop6->lock--;
  if (nexthop6->lock == 0) {
    listnode_delete (isis->nexthops6, nexthop6);
    XFREE (MTYPE_ISIS_NEXTHOP6, nexthop6);
  }
    
  return;
}

int
nexthop6lookup (struct list *nexthops6, struct in6_addr *ip6, 
                unsigned int ifindex)
{
  struct listnode *node;
  struct isis_nexthop6 *nh6;

  for (node = listhead (nexthops6); node; nextnode (node)) {
    nh6 = getdata (node);
    if (!(memcmp (ip6, &nh6->ip6, sizeof (struct in6_addr))) && 
        ifindex == nh6->ifindex)
      return 1;
  }

  return 0;
}

void
nexthop6_print (struct isis_nexthop6 *nh6)
{
  u_char buf[BUFSIZ];
  
  inet_ntop (AF_INET6, &nh6->ip6, buf, BUFSIZ);
  
  zlog_info ("      %s %u", buf, nh6->ifindex);
}

void
nexthops6_print (struct list *nhs6)
{
  struct listnode *node;
  
  for (node = listhead(nhs6); node; nextnode (node))
    nexthop6_print (getdata (node));
}


#endif /* HAVE_IPV6 */

void
adjinfo2nexthop (struct list *nexthops, struct isis_adjacency *adj)
{
  struct isis_nexthop *nh;
  struct listnode *node;
  struct in_addr *ipv4_addr;

  if (adj->ipv4_addrs == NULL)
    return;
  for (node = listhead (adj->ipv4_addrs); node; nextnode (node)) {
    ipv4_addr = getdata (node);
    if (!nexthoplookup (nexthops, ipv4_addr, 
                        adj->circuit->interface->ifindex)) {
      nh = isis_nexthop_create (ipv4_addr, 
                                adj->circuit->interface->ifindex);
      listnode_add (nexthops, nh);
    }
  }
}

#ifdef HAVE_IPV6
void
adjinfo2nexthop6 (struct list *nexthops6, struct isis_adjacency *adj)
{
  struct listnode *node;
  struct in6_addr *ipv6_addr;
  struct isis_nexthop6 *nh6;
  
  if (!adj->ipv6_addrs)
    return;

  for (node = listhead (adj->ipv6_addrs); node; nextnode (node)) {
    ipv6_addr = getdata (node);
    if (!nexthop6lookup (nexthops6, ipv6_addr, 
                         adj->circuit->interface->ifindex)) {
      nh6 = isis_nexthop6_create (ipv6_addr, 
                                  adj->circuit->interface->ifindex);
      listnode_add (nexthops6, nh6);
    }
  }
}
#endif /* HAVE_IPV6 */

struct isis_route_info *
isis_route_info_new (uint32_t cost, uint32_t depth, u_char family, 
                     struct list *adjacencies)
{
  struct isis_route_info *rinfo;
  struct isis_adjacency *adj;
  struct listnode *node;
  
  rinfo = XMALLOC (MTYPE_ISIS_ROUTE_INFO, sizeof (struct isis_route_info));
  if (!rinfo) {
    zlog_err ("ISIS-Rte: isis_route_info_new: out of memory!");
    return NULL;
  }
  memset (rinfo, 0, sizeof (struct isis_route_info));

  if (family == AF_INET) {
    rinfo->nexthops = list_new ();
    for (node = listhead (adjacencies); node; nextnode (node)) {
      adj = getdata (node);
      adjinfo2nexthop (rinfo->nexthops, adj);
    }
  }
#ifdef HAVE_IPV6
  if (family == AF_INET6) {
    rinfo->nexthops6 = list_new ();
    for (node = listhead (adjacencies); node; nextnode (node)) {
      adj =getdata (node);
      adjinfo2nexthop6 (rinfo->nexthops6, adj);
    }
  }
    
#endif /* HAVE_IPV6 */

  rinfo->cost = cost;
  rinfo->depth = depth;
      
  return rinfo;
}


void
isis_route_info_delete (struct isis_route_info *route_info)
{
  
  if (route_info->nexthops) {
    route_info->nexthops->del = (void *)isis_nexthop_delete;
    list_delete (route_info->nexthops);
  }
   
#ifdef HAVE_IPV6
  if (route_info->nexthops6) {
      route_info->nexthops6->del = (void *)isis_nexthop6_delete;
      list_delete (route_info->nexthops6);
  }
#endif /* HAVE_IPV6 */
 
  XFREE (MTYPE_ISIS_ROUTE_INFO, route_info);
}

int
isis_route_info_same_attrib (struct isis_route_info *new, 
                             struct isis_route_info *old)
{
  if (new->cost != old->cost)
    return 0;
  if (new->depth != old->depth)
    return 0;
  
  return 1;
}

int
isis_route_info_same (struct isis_route_info *new, struct isis_route_info *old,
                      u_char family)
{
  struct listnode  *node;
  struct isis_nexthop *nexthop;
#ifdef HAVE_IPV6
  struct isis_nexthop6 *nexthop6;
#endif /* HAVE_IPV6 */
  if (!isis_route_info_same_attrib (new, old))
    return 0;
  
  if (family == AF_INET) {
    for (node = listhead (new->nexthops); node; nextnode (node)) {
      nexthop = (struct isis_nexthop *) getdata (node);
      if (nexthoplookup (old->nexthops, &nexthop->ip, nexthop->ifindex) == 0)
        return 0;
    }
  
    for (node = listhead (old->nexthops); node; nextnode (node)) {
      nexthop = (struct isis_nexthop *) getdata (node);
      if (nexthoplookup (new->nexthops, &nexthop->ip, nexthop->ifindex) == 0)
        return 0;
    }
  }
#ifdef HAVE_IPV6
  else if (family == AF_INET6) {
    for (node = listhead (new->nexthops6); node; nextnode (node)) {
      nexthop6 = (struct isis_nexthop6 *) getdata (node);
      if (nexthop6lookup (old->nexthops6, &nexthop6->ip6, 
                          nexthop6->ifindex) == 0)
        return 0;
    }
  
    for (node = listhead (old->nexthops6); node; nextnode (node)) {
      nexthop6 = (struct isis_nexthop6 *) getdata (node);
      if (nexthop6lookup (new->nexthops6, &nexthop6->ip6, 
                          nexthop6->ifindex) == 0)
        return 0;
    }
  }
#endif /* HAVE_IPV6 */

  return 1;
}


void
isis_nexthops_merge (struct list *new, struct list *old)
{
  struct listnode *node;
  struct isis_nexthop *nexthop;

  for (node = listhead (new); node; nextnode (node)) {
    nexthop = (struct isis_nexthop *) getdata (node);
    if (nexthoplookup (old, &nexthop->ip, nexthop->ifindex))
      continue;
    listnode_add (old, nexthop);
    nexthop->lock++;
  }
}


#ifdef HAVE_IPV6
void
isis_nexthops6_merge (struct list *new, struct list *old)
{
  struct listnode *node;
  struct isis_nexthop6 *nexthop6;

  for (node = listhead (new); node; nextnode (node)) {
    nexthop6 = (struct isis_nexthop6 *) getdata (node);
    if (nexthop6lookup (old, &nexthop6->ip6, nexthop6->ifindex))
      continue;
    listnode_add (old, nexthop6);
    nexthop6->lock++;
  }
}
#endif /* HAVE_IPV6 */

void
isis_route_info_merge (struct isis_route_info *new, 
                       struct isis_route_info *old, u_char family)
{
  
  if (family == AF_INET) 
    isis_nexthops_merge (new->nexthops, old->nexthops);
#ifdef HAVE_IPV6
  else if (family == AF_INET6) 
    isis_nexthops6_merge (new->nexthops6, old->nexthops6);
#endif /* HAVE_IPV6 */
    
  return;
}


int
isis_route_info_prefer_new (struct isis_route_info *new, 
                            struct isis_route_info *old)
{
  
  if (!CHECK_FLAG (old->flag, ISIS_ROUTE_FLAG_ACTIVE))
    return 1;

  if (new->cost < old->cost)
    return 1;
  
  return 0;
}


struct isis_route_info *
isis_route_create (struct prefix *prefix, u_int32_t cost, u_int32_t depth,
                   struct list *adjacencies, struct isis_area *area)
{
  struct route_node *route_node;
  struct isis_route_info *rinfo_new, *rinfo_old, *route_info = NULL;
  u_char buff[BUFSIZ];
  u_char family;
  
  family = prefix->family;
  /* for debugs */
  prefix2str (prefix, buff, BUFSIZ);
  
  rinfo_new = isis_route_info_new (cost, depth, family, adjacencies);
  if (!rinfo_new) {
    zlog_err ("ISIS-Rte (%s): isis_route_create: out of memory!",
	      area->area_tag);
    return NULL;
  }
  
  if (family == AF_INET)
    route_node = route_node_get (area->route_table, prefix);  
#ifdef HAVE_IPV6
  else if (family == AF_INET6)
    route_node = route_node_get (area->route_table6, prefix);  
#endif /* HAVE_IPV6 */
  else 
    return NULL;
  rinfo_old = route_node->info;  
  if (!rinfo_old) {
    if (isis->debugs & DEBUG_RTE_EVENTS)
      zlog_info ("ISIS-Rte (%s) route created: %s", area->area_tag, buff);
    SET_FLAG(rinfo_new->flag, ISIS_ROUTE_FLAG_ACTIVE);
    route_node->info = rinfo_new;
    return rinfo_new;
  }
  
  if (isis->debugs & DEBUG_RTE_EVENTS)
    zlog_info ("ISIS-Rte (%s) route already exists: %s", area->area_tag, buff);
  
  if (isis_route_info_same (rinfo_new, rinfo_old, family)) {
    if (isis->debugs & DEBUG_RTE_EVENTS)
      zlog_info ("ISIS-Rte (%s) route unchanged: %s", area->area_tag, buff);
    isis_route_info_delete (rinfo_new);
    route_info = rinfo_old;
  } else if (isis_route_info_same_attrib (rinfo_new, rinfo_old)) {
    /* merge the nexthop lists */
    if (isis->debugs & DEBUG_RTE_EVENTS)
        zlog_info ("ISIS-Rte (%s) route changed (same attribs): %s", 
                   area->area_tag, buff);
#ifdef EXTREME_DEBUG
    zlog_info ("Old nexthops");
    nexthops6_print (rinfo_old->nexthops6);
    zlog_info ("New nexthops");
    nexthops6_print (rinfo_new->nexthops6);
#endif /* EXTREME_DEBUG */
    isis_route_info_merge (rinfo_new, rinfo_old, family);
    isis_route_info_delete (rinfo_new);
    route_info = rinfo_old;
  } else {
    if (isis_route_info_prefer_new (rinfo_new, rinfo_old)) {
      if (isis->debugs & DEBUG_RTE_EVENTS)
        zlog_info ("ISIS-Rte (%s) route changed: %s", area->area_tag, buff);
      isis_route_info_delete (rinfo_old);
      route_info = rinfo_new;
    } else {
      if (isis->debugs & DEBUG_RTE_EVENTS)
        zlog_info ("ISIS-Rte (%s) route rejected: %s", area->area_tag, buff);
      isis_route_info_delete (rinfo_new);
      route_info = rinfo_old;
    }
  }
  
  SET_FLAG (route_info->flag, ISIS_ROUTE_FLAG_ACTIVE);
  route_node->info = route_info;
  
  return route_info;
}

void
isis_route_delete (struct prefix *prefix, struct route_table *table)
{
  struct route_node *rode;
  struct isis_route_info *rinfo;
  char buff[BUFSIZ];

  /* for log */
  prefix2str (prefix, buff, BUFSIZ);


  rode = route_node_get (table, prefix);
  rinfo = rode->info;

  if (rinfo == NULL) {
    if (isis->debugs & DEBUG_RTE_EVENTS)
      zlog_info ("ISIS-Rte: tried to delete non-existant route %s", buff);
    return;
  }

  if (CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNC)) {
    UNSET_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE);
    if (isis->debugs & DEBUG_RTE_EVENTS)
      zlog_info ("ISIS-Rte: route delete  %s", buff);
    isis_zebra_route_update (prefix, rinfo);
  }
  isis_route_info_delete (rinfo);
  rode->info = NULL;
  
  return;
}

int
isis_route_validate (struct thread *thread)
{
  struct isis_area *area;
  struct route_table *table;
  struct route_node *rode;
  struct isis_route_info *rinfo;
  u_char buff[BUFSIZ];
#ifdef HAVE_IPV6
  int v6done = 0;
#endif
  area = THREAD_ARG (thread);
  table = area->route_table;
#ifdef HAVE_IPV6
 again:
#endif
  for (rode = route_top (table); rode; rode = route_next (rode)) {
    if (rode->info == NULL)
      continue;
    rinfo = rode->info;
    
    if (isis->debugs & DEBUG_RTE_EVENTS) {
      prefix2str (&rode->p, buff, BUFSIZ);
      zlog_info ("ISIS-Rte (%s): route validate: %s %s %s",
                 area->area_tag,
                 (CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNC) ?
                  "sync'ed": "nosync"),
                 (CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE) ?
                  "active": "inactive"), buff);
    }
    
    isis_zebra_route_update (&rode->p, rinfo);
    if (!CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE))
      isis_route_delete (&rode->p, area->route_table);
  }
#ifdef HAVE_IPV6
  if (v6done)
    return ISIS_OK;
  table = area->route_table6;
  v6done = 1;
  goto again;
#endif

  return ISIS_OK;
}