[quagga-debian.git] / zebra / zebra_rib.c

/* Routing Information Base.
 * Copyright (C) 1997, 98, 99, 2001 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra 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, or (at your option) any
 * later version.
 *
 * GNU Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  
 */

#include <zebra.h>

#include "prefix.h"
#include "table.h"
#include "memory.h"
#include "str.h"
#include "command.h"
#include "if.h"
#include "log.h"
#include "sockunion.h"
#include "linklist.h"
#include "thread.h"
#include "workqueue.h"
#include "prefix.h"
#include "routemap.h"
#include "vrf.h"
#include "nexthop.h"

#include "zebra/rib.h"
#include "zebra/rt.h"
#include "zebra/zserv.h"
#include "zebra/redistribute.h"
#include "zebra/debug.h"
#include "zebra/zebra_fpm.h"
#include "zebra/zebra_rnh.h"

/* Default rtm_table for all clients */
extern struct zebra_t zebrad;

/* Hold time for RIB process, should be very minimal.
 * it is useful to able to set it otherwise for testing, hence exported
 * as global here for test-rig code.
 */
int rib_process_hold_time = 10;

/* Each route type's string and default distance value. */
static const struct
{  
  int key;
  int distance;
} route_info[ZEBRA_ROUTE_MAX] =
{
  [ZEBRA_ROUTE_SYSTEM]  = {ZEBRA_ROUTE_SYSTEM,    0},
  [ZEBRA_ROUTE_KERNEL]  = {ZEBRA_ROUTE_KERNEL,    0},
  [ZEBRA_ROUTE_CONNECT] = {ZEBRA_ROUTE_CONNECT,   0},
  [ZEBRA_ROUTE_STATIC]  = {ZEBRA_ROUTE_STATIC,    1},
  [ZEBRA_ROUTE_RIP]     = {ZEBRA_ROUTE_RIP,     120},
  [ZEBRA_ROUTE_RIPNG]   = {ZEBRA_ROUTE_RIPNG,   120},
  [ZEBRA_ROUTE_OSPF]    = {ZEBRA_ROUTE_OSPF,    110},
  [ZEBRA_ROUTE_OSPF6]   = {ZEBRA_ROUTE_OSPF6,   110},
  [ZEBRA_ROUTE_ISIS]    = {ZEBRA_ROUTE_ISIS,    115},
  [ZEBRA_ROUTE_BGP]     = {ZEBRA_ROUTE_BGP,      20  /* IBGP is 200. */},
  [ZEBRA_ROUTE_BABEL]   = {ZEBRA_ROUTE_BABEL,    95},
  [ZEBRA_ROUTE_NHRP]    = {ZEBRA_ROUTE_NHRP,     10},
  /* no entry/default: 150 */
};

/* RPF lookup behaviour */
static enum multicast_mode ipv4_multicast_mode = MCAST_NO_CONFIG;

static void __attribute__((format (printf, 4, 5)))
_rnode_zlog(const char *_func, struct route_node *rn, int priority,
            const char *msgfmt, ...)
{
  char prefix[PREFIX_STRLEN], buf[256];
  char msgbuf[512];
  va_list ap;

  va_start(ap, msgfmt);
  vsnprintf(msgbuf, sizeof(msgbuf), msgfmt, ap);
  va_end(ap);

  if (rn)
    {
      rib_table_info_t *info = rn->table->info;

      snprintf(buf, sizeof(buf), "%s%s vrf %u",
               prefix2str(&rn->p, prefix, sizeof(prefix)),
               info->safi == SAFI_MULTICAST ? " (MRIB)" : "",
               info->zvrf->vrf_id);
    }
  else
    {
      snprintf(buf, sizeof(buf), "{(route_node *) NULL}");
    }

  zlog (NULL, priority, "%s: %s: %s", _func, buf, msgbuf);
}

#define rnode_debug(node, ...) \
        _rnode_zlog(__func__, node, LOG_DEBUG, __VA_ARGS__)
#define rnode_info(node, ...) \
        _rnode_zlog(__func__, node, LOG_INFO, __VA_ARGS__)

/* Add nexthop to the end of a rib node's nexthop list */
void
rib_nexthop_add (struct rib *rib, struct nexthop *nexthop)
{
  nexthop_add(&rib->nexthop, nexthop);
  rib->nexthop_num++;
}

/* Delete specified nexthop from the list. */
static void
rib_nexthop_delete (struct rib *rib, struct nexthop *nexthop)
{
  if (nexthop->next)
    nexthop->next->prev = nexthop->prev;
  if (nexthop->prev)
    nexthop->prev->next = nexthop->next;
  else
    rib->nexthop = nexthop->next;
  rib->nexthop_num--;
}

struct nexthop *
rib_nexthop_ifindex_add (struct rib *rib, ifindex_t ifindex)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_IFINDEX;
  nexthop->ifindex = ifindex;

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

struct nexthop *
rib_nexthop_ifname_add (struct rib *rib, char *ifname)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_IFNAME;
  nexthop->ifname = XSTRDUP (MTYPE_TMP, ifname);

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

struct nexthop *
rib_nexthop_ipv4_add (struct rib *rib, struct in_addr *ipv4, struct in_addr *src)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_IPV4;
  nexthop->gate.ipv4 = *ipv4;
  if (src)
    nexthop->src.ipv4 = *src;

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

struct nexthop *
rib_nexthop_ipv4_ifindex_add (struct rib *rib, struct in_addr *ipv4, 
                              struct in_addr *src, ifindex_t ifindex)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_IPV4_IFINDEX;
  nexthop->gate.ipv4 = *ipv4;
  if (src)
    nexthop->src.ipv4 = *src;
  nexthop->ifindex = ifindex;

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

struct nexthop *
rib_nexthop_ipv6_add (struct rib *rib, struct in6_addr *ipv6)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_IPV6;
  nexthop->gate.ipv6 = *ipv6;

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

static struct nexthop *
rib_nexthop_ipv6_ifname_add (struct rib *rib, struct in6_addr *ipv6,
                             char *ifname)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_IPV6_IFNAME;
  nexthop->gate.ipv6 = *ipv6;
  nexthop->ifname = XSTRDUP (MTYPE_TMP, ifname);

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

struct nexthop *
rib_nexthop_ipv6_ifindex_add (struct rib *rib, struct in6_addr *ipv6,
                              ifindex_t ifindex)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_IPV6_IFINDEX;
  nexthop->gate.ipv6 = *ipv6;
  nexthop->ifindex = ifindex;

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

struct nexthop *
rib_nexthop_blackhole_add (struct rib *rib)
{
  struct nexthop *nexthop;

  nexthop = nexthop_new ();
  nexthop->type = NEXTHOP_TYPE_BLACKHOLE;
  SET_FLAG (rib->flags, ZEBRA_FLAG_BLACKHOLE);

  rib_nexthop_add (rib, nexthop);

  return nexthop;
}

/* This method checks whether a recursive nexthop has at
 * least one resolved nexthop in the fib.
 */
int
nexthop_has_fib_child(struct nexthop *nexthop)
{
  struct nexthop *nh;

  if (! CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
    return 0;

  for (nh = nexthop->resolved; nh; nh = nh->next)
    if (CHECK_FLAG (nh->flags, NEXTHOP_FLAG_FIB))
      return 1;

  return 0;
}

/* If force flag is not set, do not modify falgs at all for uninstall
   the route from FIB. */
static int
nexthop_active_ipv4 (struct rib *rib, struct nexthop *nexthop, int set,
                     struct route_node *top)
{
  struct prefix_ipv4 p;
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  int resolved;
  struct nexthop *newhop;
  struct nexthop *resolved_hop;

  if (nexthop->type == NEXTHOP_TYPE_IPV4)
    nexthop->ifindex = 0;

  if (set)
    {
      UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE);
      nexthops_free(nexthop->resolved);
      nexthop->resolved = NULL;
      rib->nexthop_mtu = 0;
    }

  /* Make lookup prefix. */
  memset (&p, 0, sizeof (struct prefix_ipv4));
  p.family = AF_INET;
  p.prefixlen = IPV4_MAX_PREFIXLEN;
  p.prefix = nexthop->gate.ipv4;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, SAFI_UNICAST, rib->vrf_id);
  if (! table)
    return 0;

  rn = route_node_match (table, (struct prefix *) &p);
  while (rn)
    {
      route_unlock_node (rn);
      
      /* If lookup self prefix return immediately. */
      if (rn == top)
        return 0;

      /* Pick up selected route. */
      RNODE_FOREACH_RIB (rn, match)
        {
          if (CHECK_FLAG (match->status, RIB_ENTRY_REMOVED))
            continue;
          if (CHECK_FLAG (match->status, RIB_ENTRY_SELECTED_FIB))
            break;
        }

      /* If there is no selected route or matched route is EGP, go up
         tree. */
      if (! match 
          || match->type == ZEBRA_ROUTE_BGP)
        {
          do {
            rn = rn->parent;
          } while (rn && rn->info == NULL);
          if (rn)
            route_lock_node (rn);
        }
      else
        {
          /* If the longest prefix match for the nexthop yields
           * a blackhole, mark it as inactive. */
          if (CHECK_FLAG (match->flags, ZEBRA_FLAG_BLACKHOLE)
              || CHECK_FLAG (match->flags, ZEBRA_FLAG_REJECT))
            return 0;

          if (match->type == ZEBRA_ROUTE_CONNECT)
            {
              /* Directly point connected route. */
              newhop = match->nexthop;
              if (newhop && nexthop->type == NEXTHOP_TYPE_IPV4)
                nexthop->ifindex = newhop->ifindex;
              
              return 1;
            }
          else if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_INTERNAL))
            {
              resolved = 0;
              for (newhop = match->nexthop; newhop; newhop = newhop->next)
                if (CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_FIB)
                    && ! CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_RECURSIVE))
                  {
                    if (set)
                      {
                        SET_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE);

                        resolved_hop = XCALLOC(MTYPE_NEXTHOP, sizeof (struct nexthop));
                        SET_FLAG (resolved_hop->flags, NEXTHOP_FLAG_ACTIVE);
                        /* If the resolving route specifies a gateway, use it */
                        if (newhop->type == NEXTHOP_TYPE_IPV4
                            || newhop->type == NEXTHOP_TYPE_IPV4_IFINDEX
                            || newhop->type == NEXTHOP_TYPE_IPV4_IFNAME)
                          {
                            resolved_hop->type = newhop->type;
                            resolved_hop->gate.ipv4 = newhop->gate.ipv4;
                            resolved_hop->ifindex = newhop->ifindex;
                          }

                        /* If the resolving route is an interface route, it
                         * means the gateway we are looking up is connected
                         * to that interface. Therefore, the resolved route
                         * should have the original gateway as nexthop as it
                         * is directly connected. */
                        if (newhop->type == NEXTHOP_TYPE_IFINDEX
                            || newhop->type == NEXTHOP_TYPE_IFNAME)
                          {
                            resolved_hop->type = NEXTHOP_TYPE_IPV4_IFINDEX;
                            resolved_hop->gate.ipv4 = nexthop->gate.ipv4;
                            resolved_hop->ifindex = newhop->ifindex;
                          }

                        nexthop_add(&nexthop->resolved, resolved_hop);
                      }
                    resolved = 1;
                  }
              if (resolved && set)
                rib->nexthop_mtu = match->mtu;
              return resolved;
            }
          else
            {
              return 0;
            }
        }
    }
  return 0;
}

/* If force flag is not set, do not modify falgs at all for uninstall
   the route from FIB. */
static int
nexthop_active_ipv6 (struct rib *rib, struct nexthop *nexthop, int set,
                     struct route_node *top)
{
  struct prefix_ipv6 p;
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  int resolved;
  struct nexthop *newhop;
  struct nexthop *resolved_hop;

  if (nexthop->type == NEXTHOP_TYPE_IPV6)
    nexthop->ifindex = 0;

  if (set)
    {
      UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE);
      nexthops_free(nexthop->resolved);
      nexthop->resolved = NULL;
    }

  /* Make lookup prefix. */
  memset (&p, 0, sizeof (struct prefix_ipv6));
  p.family = AF_INET6;
  p.prefixlen = IPV6_MAX_PREFIXLEN;
  p.prefix = nexthop->gate.ipv6;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP6, SAFI_UNICAST, rib->vrf_id);
  if (! table)
    return 0;

  rn = route_node_match (table, (struct prefix *) &p);
  while (rn)
    {
      route_unlock_node (rn);
      
      /* If lookup self prefix return immediately. */
      if (rn == top)
        return 0;

      /* Pick up selected route. */
      RNODE_FOREACH_RIB (rn, match)
        {
          if (CHECK_FLAG (match->status, RIB_ENTRY_REMOVED))
            continue;
          if (CHECK_FLAG (match->status, RIB_ENTRY_SELECTED_FIB))
            break;
        }

      /* If there is no selected route or matched route is EGP, go up
         tree. */
      if (! match
          || match->type == ZEBRA_ROUTE_BGP)
        {
          do {
            rn = rn->parent;
          } while (rn && rn->info == NULL);
          if (rn)
            route_lock_node (rn);
        }
      else
        {
          /* If the longest prefix match for the nexthop yields
           * a blackhole, mark it as inactive. */
          if (CHECK_FLAG (match->flags, ZEBRA_FLAG_BLACKHOLE)
              || CHECK_FLAG (match->flags, ZEBRA_FLAG_REJECT))
            return 0;

          if (match->type == ZEBRA_ROUTE_CONNECT)
            {
              /* Directly point connected route. */
              newhop = match->nexthop;

              if (newhop && nexthop->type == NEXTHOP_TYPE_IPV6)
                nexthop->ifindex = newhop->ifindex;
              
              return 1;
            }
          else if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_INTERNAL))
            {
              resolved = 0;
              for (newhop = match->nexthop; newhop; newhop = newhop->next)
                if (CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_FIB)
                    && ! CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_RECURSIVE))
                  {
                    if (set)
                      {
                        SET_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE);

                        resolved_hop = XCALLOC(MTYPE_NEXTHOP, sizeof (struct nexthop));
                        SET_FLAG (resolved_hop->flags, NEXTHOP_FLAG_ACTIVE);
                        /* See nexthop_active_ipv4 for a description how the
                         * resolved nexthop is constructed. */
                        if (newhop->type == NEXTHOP_TYPE_IPV6
                            || newhop->type == NEXTHOP_TYPE_IPV6_IFINDEX
                            || newhop->type == NEXTHOP_TYPE_IPV6_IFNAME)
                          {
                            resolved_hop->type = newhop->type;
                            resolved_hop->gate.ipv6 = newhop->gate.ipv6;

                            if (newhop->ifindex)
                              {
                                resolved_hop->type = NEXTHOP_TYPE_IPV6_IFINDEX;
                                resolved_hop->ifindex = newhop->ifindex;
                              }
                          }

                        if (newhop->type == NEXTHOP_TYPE_IFINDEX
                            || newhop->type == NEXTHOP_TYPE_IFNAME)
                          {
                                resolved_hop->flags |= NEXTHOP_FLAG_ONLINK;
                                resolved_hop->type = NEXTHOP_TYPE_IPV6_IFINDEX;
                                resolved_hop->gate.ipv6 = nexthop->gate.ipv6;
                                resolved_hop->ifindex = newhop->ifindex;
                          }

                        nexthop_add(&nexthop->resolved, resolved_hop);
                      }
                    resolved = 1;
                  }
              return resolved;
            }
          else
            {
              return 0;
            }
        }
    }
  return 0;
}

struct rib *
rib_match_ipv4_safi (struct in_addr addr, safi_t safi, int skip_bgp,
                     struct route_node **rn_out, vrf_id_t vrf_id)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  struct nexthop *newhop, *tnewhop;
  int recursing;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, safi, vrf_id);
  if (! table)
    return 0;

  rn = route_node_match_ipv4 (table, &addr);

  while (rn)
    {
      route_unlock_node (rn);

      /* Pick up selected route. */
      RNODE_FOREACH_RIB (rn, match)
        {
          if (CHECK_FLAG (match->status, RIB_ENTRY_REMOVED))
            continue;
          if (CHECK_FLAG (match->status, RIB_ENTRY_SELECTED_FIB))
            break;
        }

      /* If there is no selected route or matched route is EGP, go up
         tree. */
      if (!match || (skip_bgp && (match->type == ZEBRA_ROUTE_BGP)))
        {
          do {
            rn = rn->parent;
          } while (rn && rn->info == NULL);
          if (rn)
            route_lock_node (rn);
        }
      else
        {
          if (match->type != ZEBRA_ROUTE_CONNECT)
            {
              int found = 0;
              for (ALL_NEXTHOPS_RO(match->nexthop, newhop, tnewhop, recursing))
                if (CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_FIB))
                  {
                    found = 1;
                    break;
                  }
              if (!found)
                return NULL;
            }

          if (rn_out)
            *rn_out = rn;
          return match;
        }
    }
  return NULL;
}

struct rib *
rib_match_ipv4_multicast (struct in_addr addr, struct route_node **rn_out,
    vrf_id_t vrf_id)
{
  struct rib *rib = NULL, *mrib = NULL, *urib = NULL;
  struct route_node *m_rn = NULL, *u_rn = NULL;
  int skip_bgp = 0; /* bool */

  switch (ipv4_multicast_mode)
    {
    case MCAST_MRIB_ONLY:
      return rib_match_ipv4_safi (addr, SAFI_MULTICAST, skip_bgp, rn_out,
                                  vrf_id);
    case MCAST_URIB_ONLY:
      return rib_match_ipv4_safi (addr, SAFI_UNICAST, skip_bgp, rn_out,
                                  vrf_id);
    case MCAST_NO_CONFIG:
    case MCAST_MIX_MRIB_FIRST:
      rib = mrib = rib_match_ipv4_safi (addr, SAFI_MULTICAST, skip_bgp, &m_rn,
                                        vrf_id);
      if (!mrib)
        rib = urib = rib_match_ipv4_safi (addr, SAFI_UNICAST, skip_bgp, &u_rn,
                                          vrf_id);
      break;
    case MCAST_MIX_DISTANCE:
      mrib = rib_match_ipv4_safi (addr, SAFI_MULTICAST, skip_bgp, &m_rn,
                                  vrf_id);
      urib = rib_match_ipv4_safi (addr, SAFI_UNICAST, skip_bgp, &u_rn,
                                  vrf_id);
      if (mrib && urib)
        rib = urib->distance < mrib->distance ? urib : mrib;
      else if (mrib)
        rib = mrib;
      else if (urib)
        rib = urib;
      break;
    case MCAST_MIX_PFXLEN:
      mrib = rib_match_ipv4_safi (addr, SAFI_MULTICAST, skip_bgp, &m_rn,
                                  vrf_id);
      urib = rib_match_ipv4_safi (addr, SAFI_UNICAST, skip_bgp, &u_rn,
                                  vrf_id);
      if (mrib && urib)
        rib = u_rn->p.prefixlen > m_rn->p.prefixlen ? urib : mrib;
      else if (mrib)
        rib = mrib;
      else if (urib)
        rib = urib;
      break;
  }

  if (rn_out)
    *rn_out = (rib == mrib) ? m_rn : u_rn;

  if (IS_ZEBRA_DEBUG_RIB)
    {
      char buf[BUFSIZ];
      inet_ntop (AF_INET, &addr, buf, BUFSIZ);

      zlog_debug("%s: %s vrf %u: found %s, using %s",
                 __func__, buf, vrf_id,
                 mrib ? (urib ? "MRIB+URIB" : "MRIB") :
                         urib ? "URIB" : "nothing",
                 rib == urib ? "URIB" : rib == mrib ? "MRIB" : "none");
    }
  return rib;
}

void
multicast_mode_ipv4_set (enum multicast_mode mode)
{
  if (IS_ZEBRA_DEBUG_RIB)
    zlog_debug("%s: multicast lookup mode set (%d)", __func__, mode);
  ipv4_multicast_mode = mode;
}

enum multicast_mode
multicast_mode_ipv4_get (void)
{
  return ipv4_multicast_mode;
}

struct rib *
rib_lookup_ipv4 (struct prefix_ipv4 *p, vrf_id_t vrf_id)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  struct nexthop *nexthop, *tnexthop;
  int recursing;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, SAFI_UNICAST, vrf_id);
  if (! table)
    return 0;

  rn = route_node_lookup (table, (struct prefix *) p);

  /* No route for this prefix. */
  if (! rn)
    return NULL;

  /* Unlock node. */
  route_unlock_node (rn);

  RNODE_FOREACH_RIB (rn, match)
    {
      if (CHECK_FLAG (match->status, RIB_ENTRY_REMOVED))
        continue;
      if (CHECK_FLAG (match->status, RIB_ENTRY_SELECTED_FIB))
        break;
    }

  if (! match || match->type == ZEBRA_ROUTE_BGP)
    return NULL;

  if (match->type == ZEBRA_ROUTE_CONNECT)
    return match;
  
  for (ALL_NEXTHOPS_RO(match->nexthop, nexthop, tnexthop, recursing))
    if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB))
      return match;

  return NULL;
}

/*
 * This clone function, unlike its original rib_lookup_ipv4(), checks
 * if specified IPv4 route record (prefix/mask -> gate) exists in
 * the whole RIB and has ZEBRA_FLAG_SELECTED set.
 *
 * Return values:
 * -1: error
 * 0: exact match found
 * 1: a match was found with a different gate
 * 2: connected route found
 * 3: no matches found
 */
int
rib_lookup_ipv4_route (struct prefix_ipv4 *p, union sockunion * qgate,
    vrf_id_t vrf_id)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  struct nexthop *nexthop, *tnexthop;
  int recursing;
  int nexthops_active;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, SAFI_UNICAST, vrf_id);
  if (! table)
    return ZEBRA_RIB_LOOKUP_ERROR;

  /* Scan the RIB table for exactly matching RIB entry. */
  rn = route_node_lookup (table, (struct prefix *) p);

  /* No route for this prefix. */
  if (! rn)
    return ZEBRA_RIB_NOTFOUND;

  /* Unlock node. */
  route_unlock_node (rn);

  /* Find out if a "selected" RR for the discovered RIB entry exists ever. */
  RNODE_FOREACH_RIB (rn, match)
    {
      if (CHECK_FLAG (match->status, RIB_ENTRY_REMOVED))
        continue;
      if (CHECK_FLAG (match->status, RIB_ENTRY_SELECTED_FIB))
        break;
    }

  /* None such found :( */
  if (!match)
    return ZEBRA_RIB_NOTFOUND;

  if (match->type == ZEBRA_ROUTE_CONNECT)
    return ZEBRA_RIB_FOUND_CONNECTED;
  
  /* Ok, we have a cood candidate, let's check it's nexthop list... */
  nexthops_active = 0;
  for (ALL_NEXTHOPS_RO(match->nexthop, nexthop, tnexthop, recursing))
    if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB))
      {
        nexthops_active = 1;
        if (nexthop->gate.ipv4.s_addr == sockunion2ip (qgate))
          return ZEBRA_RIB_FOUND_EXACT;
        if (IS_ZEBRA_DEBUG_RIB)
          {
            char gate_buf[INET_ADDRSTRLEN], qgate_buf[INET_ADDRSTRLEN];
            inet_ntop (AF_INET, &nexthop->gate.ipv4.s_addr, gate_buf, INET_ADDRSTRLEN);
            inet_ntop (AF_INET, &sockunion2ip(qgate), qgate_buf, INET_ADDRSTRLEN);
            zlog_debug ("%s: qgate == %s, %s == %s", __func__,
                        qgate_buf, recursing ? "rgate" : "gate", gate_buf);
          }
      }

  if (nexthops_active)
    return ZEBRA_RIB_FOUND_NOGATE;

  return ZEBRA_RIB_NOTFOUND;
}

struct rib *
rib_match_ipv6 (struct in6_addr *addr, vrf_id_t vrf_id)
{
  struct prefix_ipv6 p;
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  struct nexthop *newhop, *tnewhop;
  int recursing;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP6, SAFI_UNICAST, vrf_id);
  if (! table)
    return 0;

  memset (&p, 0, sizeof (struct prefix_ipv6));
  p.family = AF_INET6;
  p.prefixlen = IPV6_MAX_PREFIXLEN;
  IPV6_ADDR_COPY (&p.prefix, addr);

  rn = route_node_match (table, (struct prefix *) &p);

  while (rn)
    {
      route_unlock_node (rn);
      
      /* Pick up selected route. */
      RNODE_FOREACH_RIB (rn, match)
        {
          if (CHECK_FLAG (match->status, RIB_ENTRY_REMOVED))
            continue;
          if (CHECK_FLAG (match->status, RIB_ENTRY_SELECTED_FIB))
            break;
        }

      /* If there is no selected route or matched route is EGP, go up
         tree. */
      if (! match 
          || match->type == ZEBRA_ROUTE_BGP)
        {
          do {
            rn = rn->parent;
          } while (rn && rn->info == NULL);
          if (rn)
            route_lock_node (rn);
        }
      else
        {
          if (match->type == ZEBRA_ROUTE_CONNECT)
            /* Directly point connected route. */
            return match;
          else
            {
              for (ALL_NEXTHOPS_RO(match->nexthop, newhop, tnewhop, recursing))
                if (CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_FIB))
                  return match;
              return NULL;
            }
        }
    }
  return NULL;
}

#define RIB_SYSTEM_ROUTE(R) \
        ((R)->type == ZEBRA_ROUTE_KERNEL || (R)->type == ZEBRA_ROUTE_CONNECT)

/* This function verifies reachability of one given nexthop, which can be
 * numbered or unnumbered, IPv4 or IPv6. The result is unconditionally stored
 * in nexthop->flags field. If the 4th parameter, 'set', is non-zero,
 * nexthop->ifindex will be updated appropriately as well.
 * An existing route map can turn (otherwise active) nexthop into inactive, but
 * not vice versa.
 *
 * The return value is the final value of 'ACTIVE' flag.
 */

static unsigned
nexthop_active_check (struct route_node *rn, struct rib *rib,
                      struct nexthop *nexthop, int set)
{
  rib_table_info_t *info = rn->table->info;
  struct interface *ifp;
  route_map_result_t ret = RMAP_MATCH;
  extern char *proto_rm[AFI_MAX][ZEBRA_ROUTE_MAX+1];
  struct route_map *rmap;
  int family;

  family = 0;
  switch (nexthop->type)
    {
    case NEXTHOP_TYPE_IFINDEX:
      ifp = if_lookup_by_index_vrf (nexthop->ifindex, rib->vrf_id);
      if (ifp && if_is_operative(ifp))
        SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      else
        UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      break;
    case NEXTHOP_TYPE_IPV6_IFNAME:
      family = AFI_IP6;
    case NEXTHOP_TYPE_IFNAME:
      ifp = if_lookup_by_name_vrf (nexthop->ifname, rib->vrf_id);
      if (ifp && if_is_operative(ifp))
        {
          if (set)
            nexthop->ifindex = ifp->ifindex;
          SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
        }
      else
        {
          if (set)
            nexthop->ifindex = 0;
          UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
        }
      break;
    case NEXTHOP_TYPE_IPV4:
    case NEXTHOP_TYPE_IPV4_IFINDEX:
      family = AFI_IP;
      if (nexthop_active_ipv4 (rib, nexthop, set, rn))
        SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      else
        UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      break;
    case NEXTHOP_TYPE_IPV6:
      family = AFI_IP6;
      if (nexthop_active_ipv6 (rib, nexthop, set, rn))
        SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      else
        UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      break;
    case NEXTHOP_TYPE_IPV6_IFINDEX:
      family = AFI_IP6;
      if (IN6_IS_ADDR_LINKLOCAL (&nexthop->gate.ipv6))
        {
          ifp = if_lookup_by_index_vrf (nexthop->ifindex, rib->vrf_id);
          if (ifp && if_is_operative(ifp))
            SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
          else
            UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
        }
      else
        {
          if (nexthop_active_ipv6 (rib, nexthop, set, rn))
            SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
          else
            UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
        }
      break;
    case NEXTHOP_TYPE_BLACKHOLE:
      SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      break;
    default:
      break;
    }
  if (! CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE))
    return 0;

  /* XXX: What exactly do those checks do? Do we support
   * e.g. IPv4 routes with IPv6 nexthops or vice versa? */
  if (RIB_SYSTEM_ROUTE(rib) ||
      (family == AFI_IP && rn->p.family != AF_INET) ||
      (family == AFI_IP6 && rn->p.family != AF_INET6))
    return CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);

  /* The original code didn't determine the family correctly
   * e.g. for NEXTHOP_TYPE_IFINDEX. Retrieve the correct afi
   * from the rib_table_info in those cases.
   * Possibly it may be better to use only the rib_table_info
   * in every case.
   */
  if (!family)
    family = info->afi;

  rmap = 0;
  if (rib->type >= 0 && rib->type < ZEBRA_ROUTE_MAX &&
                proto_rm[family][rib->type])
    rmap = route_map_lookup_by_name (proto_rm[family][rib->type]);
  if (!rmap && proto_rm[family][ZEBRA_ROUTE_MAX])
    rmap = route_map_lookup_by_name (proto_rm[family][ZEBRA_ROUTE_MAX]);
  if (rmap) {
      struct nexthop_vrfid nh_vrf = {nexthop, rib->vrf_id};
      ret = route_map_apply(rmap, &rn->p, RMAP_ZEBRA, &nh_vrf);
  }

  if (ret == RMAP_DENYMATCH)
    UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
  return CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
}

/* Iterate over all nexthops of the given RIB entry and refresh their
 * ACTIVE flag. rib->nexthop_active_num is updated accordingly. If any
 * nexthop is found to toggle the ACTIVE flag, the whole rib structure
 * is flagged with RIB_ENTRY_CHANGED. The 4th 'set' argument is
 * transparently passed to nexthop_active_check().
 *
 * Return value is the new number of active nexthops.
 */

static int
nexthop_active_update (struct route_node *rn, struct rib *rib, int set)
{
  struct nexthop *nexthop;
  unsigned int prev_active, new_active;
  ifindex_t prev_index;
  
  rib->nexthop_active_num = 0;

  for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
  {
    prev_active = CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
    prev_index = nexthop->ifindex;
    if ((new_active = nexthop_active_check (rn, rib, nexthop, set)))
      rib->nexthop_active_num++;
    if (prev_active != new_active ||
        prev_index != nexthop->ifindex)
      SET_FLAG (rib->status, RIB_ENTRY_CHANGED);
  }
  return rib->nexthop_active_num;
}



static int
rib_update_kernel (struct route_node *rn, struct rib *old, struct rib *new)
{
  int ret = 0;
  struct nexthop *nexthop, *tnexthop;
  rib_table_info_t *info = rn->table->info;
  int recursing;

  if (info->safi != SAFI_UNICAST)
    {
      if (new)
        for (ALL_NEXTHOPS_RO(new->nexthop, nexthop, tnexthop, recursing))
          SET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);
      if (old)
        for (ALL_NEXTHOPS_RO(old->nexthop, nexthop, tnexthop, recursing))
          UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);
      return 0;
    }

  /*
   * Make sure we update the FPM any time we send new information to
   * the kernel.
   */
  zfpm_trigger_update (rn, "updating in kernel");

  ret = kernel_route_rib (&rn->p, old, new);

  /* This condition is never met, if we are using rt_socket.c */
  if (ret < 0 && new)
    {
      for (ALL_NEXTHOPS_RO(new->nexthop, nexthop, tnexthop, recursing))
        UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);
    }
  else if (old && old != new)
    {
      for (ALL_NEXTHOPS_RO(old->nexthop, nexthop, tnexthop, recursing))
        UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);
    }

  return ret;
}

/* Uninstall the route from kernel. */
static void
rib_uninstall (struct route_node *rn, struct rib *rib)
{
  rib_table_info_t *info = rn->table->info;

  if (CHECK_FLAG (rib->status, RIB_ENTRY_SELECTED_FIB))
    {
      if (info->safi == SAFI_UNICAST)
        zfpm_trigger_update (rn, "rib_uninstall");

      redistribute_delete (&rn->p, rib);
      if (! RIB_SYSTEM_ROUTE (rib))
        rib_update_kernel (rn, rib, NULL);
      UNSET_FLAG (rib->flags, ZEBRA_FLAG_SELECTED);
    }
}

static void rib_unlink (struct route_node *, struct rib *);

/*
 * rib_can_delete_dest
 *
 * Returns TRUE if the given dest can be deleted from the table.
 */
static int
rib_can_delete_dest (rib_dest_t *dest)
{
  if (dest->routes)
    {
      return 0;
    }

  /*
   * Don't delete the dest if we have to update the FPM about this
   * prefix.
   */
  if (CHECK_FLAG (dest->flags, RIB_DEST_UPDATE_FPM) ||
      CHECK_FLAG (dest->flags, RIB_DEST_SENT_TO_FPM))
    return 0;

  return 1;
}

/*
 * rib_gc_dest
 *
 * Garbage collect the rib dest corresponding to the given route node
 * if appropriate.
 *
 * Returns TRUE if the dest was deleted, FALSE otherwise.
 */
int
rib_gc_dest (struct route_node *rn)
{
  rib_dest_t *dest;

  dest = rib_dest_from_rnode (rn);
  if (!dest)
    return 0;

  if (!rib_can_delete_dest (dest))
    return 0;

  if (IS_ZEBRA_DEBUG_RIB)
    rnode_debug (rn, "removing dest from table");

  dest->rnode = NULL;
  XFREE (MTYPE_RIB_DEST, dest);
  rn->info = NULL;

  /*
   * Release the one reference that we keep on the route node.
   */
  route_unlock_node (rn);
  return 1;
}

/* Check if 'alternate' RIB entry is better than 'current'. */
static struct rib *
rib_choose_best (struct rib *current, struct rib *alternate)
{
  if (current == NULL)
    return alternate;

  /* filter route selection in following order:
   * - connected beats other types
   * - lower distance beats higher
   * - lower metric beats higher for equal distance
   * - last, hence oldest, route wins tie break.
   */

  /* Connected routes. Pick the last connected
   * route of the set of lowest metric connected routes.
   */
  if (alternate->type == ZEBRA_ROUTE_CONNECT)
    {
      if (current->type != ZEBRA_ROUTE_CONNECT
          || alternate->metric <= current->metric)
        return alternate;

      return current;
    }

  if (current->type == ZEBRA_ROUTE_CONNECT)
    return current;

  /* higher distance loses */
  if (alternate->distance < current->distance)
    return alternate;
  if (current->distance < alternate->distance)
    return current;

  /* metric tie-breaks equal distance */
  if (alternate->metric <= current->metric)
    return alternate;

  return current;
}

/* Core function for processing routing information base. */
static void
rib_process (struct route_node *rn)
{
  struct rib *rib;
  struct rib *next;
  struct rib *old_selected = NULL;
  struct rib *new_selected = NULL;
  struct rib *old_fib = NULL;
  struct rib *new_fib = NULL;
  int installed = 0;
  struct nexthop *nexthop = NULL, *tnexthop;
  int recursing;
  rib_table_info_t *info;

  assert (rn);

  info = rn->table->info;

  RNODE_FOREACH_RIB (rn, rib)
    {
      UNSET_FLAG (rib->status, RIB_ENTRY_CHANGED);

      /* Currently installed rib. */
      if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_SELECTED))
        {
          assert (old_selected == NULL);
          old_selected = rib;
        }
      if (CHECK_FLAG (rib->status, RIB_ENTRY_SELECTED_FIB))
        {
          assert (old_fib == NULL);
          old_fib = rib;
        }

      /* Skip deleted entries from selection */
      if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
        continue;
      
      /* Skip unreachable nexthop. */
      if (! nexthop_active_update (rn, rib, 0))
        continue;

      /* Infinit distance. */
      if (rib->distance == DISTANCE_INFINITY)
        continue;

      if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_FIB_OVERRIDE))
        new_fib = rib_choose_best(new_fib, rib);
      else
        new_selected = rib_choose_best(new_selected, rib);
    } /* RNODE_FOREACH_RIB_SAFE */

  /* If no FIB override route, use the selected route also for FIB */
  if (new_fib == NULL)
    new_fib = new_selected;

  /* After the cycle is finished, the following pointers will be set:
   * old_selected --- RIB entry currently having SELECTED
   * new_selected --- RIB entry that is newly SELECTED
   * old_fib      --- RIB entry currently in kernel FIB
   * new_fib      --- RIB entry that is newly to be in kernel FIB
   *
   * new_selected will get SELECTED flag, and is going to be redistributed
   * the zclients. new_fib (which can be new_selected) will be installed in kernel.
   */

  /* Set real nexthops. */
  if (new_fib)
    nexthop_active_update (rn, new_fib, 1);
  if (new_selected && new_selected != new_fib)
    nexthop_active_update (rn, new_selected, 1);

  /* Update kernel if FIB entry has changed */
  if (old_fib != new_fib
      || (new_fib && CHECK_FLAG (new_fib->status, RIB_ENTRY_CHANGED)))
    {
        if (old_fib && old_fib != new_fib)
          {
            if (! RIB_SYSTEM_ROUTE (old_fib) && (! new_fib || RIB_SYSTEM_ROUTE (new_fib)))
              rib_update_kernel (rn, old_fib, NULL);
            UNSET_FLAG (old_fib->status, RIB_ENTRY_SELECTED_FIB);
          }

        if (new_fib)
          {
            /* Install new or replace existing FIB entry */
            SET_FLAG (new_fib->status, RIB_ENTRY_SELECTED_FIB);
            if (! RIB_SYSTEM_ROUTE (new_fib))
              rib_update_kernel (rn, old_fib, new_fib);
          }

        if (info->safi == SAFI_UNICAST)
          zfpm_trigger_update (rn, "updating existing route");
    }
  else if (old_fib == new_fib && new_fib && ! RIB_SYSTEM_ROUTE (new_fib))
    {
      /* Housekeeping code to deal with race conditions in kernel with
       * linux netlink reporting interface up before IPv4 or IPv6 protocol
       * is ready to add routes. This makes sure routes are IN the kernel.
       */
      for (ALL_NEXTHOPS_RO(new_fib->nexthop, nexthop, tnexthop, recursing))
        if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB))
          {
            installed = 1;
            break;
          }
      if (! installed)
        rib_update_kernel (rn, NULL, new_fib);
    }

  /* Redistribute SELECTED entry */
  if (old_selected != new_selected
      || (new_selected && CHECK_FLAG (new_selected->status, RIB_ENTRY_CHANGED)))
    {
      if (old_selected)
        {
          if (! new_selected)
            redistribute_delete (&rn->p, old_selected);
          if (old_selected != new_selected)
            UNSET_FLAG (old_selected->flags, ZEBRA_FLAG_SELECTED);
        }

      if (new_selected)
        {
          /* Install new or replace existing redistributed entry */
          SET_FLAG (new_selected->flags, ZEBRA_FLAG_SELECTED);
          redistribute_add (&rn->p, new_selected);
        }
     }

  /* Remove all RIB entries queued for removal */
  RNODE_FOREACH_RIB_SAFE (rn, rib, next)
    {
      if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
        {
          if (IS_ZEBRA_DEBUG_RIB)
            rnode_debug (rn, "rn %p, removing rib %p",
                        (void *)rn, (void *)rib);
          rib_unlink (rn, rib);
        }
    }

  if (IS_ZEBRA_DEBUG_RIB_Q)
    rnode_debug (rn, "rn %p dequeued", (void *)rn);

  /*
   * Check if the dest can be deleted now.
   */
  rib_gc_dest (rn);
}

/* Take a list of route_node structs and return 1, if there was a record
 * picked from it and processed by rib_process(). Don't process more, 
 * than one RN record; operate only in the specified sub-queue.
 */
static unsigned int
process_subq (struct list * subq, u_char qindex)
{
  struct listnode *lnode  = listhead (subq);
  struct route_node *rnode;

  if (!lnode)
    return 0;

  rnode = listgetdata (lnode);
  rib_process (rnode);

  if (rnode->info)
    UNSET_FLAG (rib_dest_from_rnode (rnode)->flags, RIB_ROUTE_QUEUED (qindex));

#if 0
  else
    {
      zlog_debug ("%s: called for route_node (%p, %d) with no ribs",
                  __func__, rnode, rnode->lock);
      zlog_backtrace(LOG_DEBUG);
    }
#endif
  route_unlock_node (rnode);
  list_delete_node (subq, lnode);
  return 1;
}

/*
 * All meta queues have been processed. Trigger next-hop evaluation.
 */
static void
meta_queue_process_complete (struct work_queue *dummy)
{
  zebra_evaluate_rnh_table(0, AF_INET);
#ifdef HAVE_IPV6
  zebra_evaluate_rnh_table(0, AF_INET6);
#endif /* HAVE_IPV6 */
}

/* Dispatch the meta queue by picking, processing and unlocking the next RN from
 * a non-empty sub-queue with lowest priority. wq is equal to zebra->ribq and data
 * is pointed to the meta queue structure.
 */
static wq_item_status
meta_queue_process (struct work_queue *dummy, void *data)
{
  struct meta_queue * mq = data;
  unsigned i;

  for (i = 0; i < MQ_SIZE; i++)
    if (process_subq (mq->subq[i], i))
      {
        mq->size--;
        break;
      }
  return mq->size ? WQ_REQUEUE : WQ_SUCCESS;
}

/*
 * Map from rib types to queue type (priority) in meta queue
 */
static const u_char meta_queue_map[ZEBRA_ROUTE_MAX] = {
  [ZEBRA_ROUTE_SYSTEM]  = 4,
  [ZEBRA_ROUTE_KERNEL]  = 0,
  [ZEBRA_ROUTE_CONNECT] = 0,
  [ZEBRA_ROUTE_STATIC]  = 1,
  [ZEBRA_ROUTE_RIP]     = 2,
  [ZEBRA_ROUTE_RIPNG]   = 2,
  [ZEBRA_ROUTE_OSPF]    = 2,
  [ZEBRA_ROUTE_OSPF6]   = 2,
  [ZEBRA_ROUTE_ISIS]    = 2,
  [ZEBRA_ROUTE_BGP]     = 3,
  [ZEBRA_ROUTE_HSLS]    = 4,
  [ZEBRA_ROUTE_BABEL]   = 2,
  [ZEBRA_ROUTE_NHRP]    = 2,
};

/* Look into the RN and queue it into one or more priority queues,
 * increasing the size for each data push done.
 */
static void
rib_meta_queue_add (struct meta_queue *mq, struct route_node *rn)
{
  struct rib *rib;

  RNODE_FOREACH_RIB (rn, rib)
    {
      u_char qindex = meta_queue_map[rib->type];

      /* Invariant: at this point we always have rn->info set. */
      if (CHECK_FLAG (rib_dest_from_rnode (rn)->flags,
                      RIB_ROUTE_QUEUED (qindex)))
        {
          if (IS_ZEBRA_DEBUG_RIB_Q)
            rnode_debug (rn, "rn %p is already queued in sub-queue %u",
                         (void *)rn, qindex);
          continue;
        }

      SET_FLAG (rib_dest_from_rnode (rn)->flags, RIB_ROUTE_QUEUED (qindex));
      listnode_add (mq->subq[qindex], rn);
      route_lock_node (rn);
      mq->size++;

      if (IS_ZEBRA_DEBUG_RIB_Q)
        rnode_debug (rn, "queued rn %p into sub-queue %u",
                     (void *)rn, qindex);
    }
}

/* Add route_node to work queue and schedule processing */
static void
rib_queue_add (struct zebra_t *zebra, struct route_node *rn)
{
  assert (zebra && rn);

  /* Pointless to queue a route_node with no RIB entries to add or remove */
  if (!rnode_to_ribs (rn))
    {
      zlog_debug ("%s: called for route_node (%p, %d) with no ribs",
                  __func__, (void *)rn, rn->lock);
      zlog_backtrace(LOG_DEBUG);
      return;
    }

  if (IS_ZEBRA_DEBUG_RIB_Q)
    rnode_info (rn, "work queue added");

  assert (zebra);

  if (zebra->ribq == NULL)
    {
      zlog_err ("%s: work_queue does not exist!", __func__);
      return;
    }

  /*
   * The RIB queue should normally be either empty or holding the only
   * work_queue_item element. In the latter case this element would
   * hold a pointer to the meta queue structure, which must be used to
   * actually queue the route nodes to process. So create the MQ
   * holder, if necessary, then push the work into it in any case.
   * This semantics was introduced after 0.99.9 release.
   */
  if (!zebra->ribq->items->count)
    work_queue_add (zebra->ribq, zebra->mq);

  rib_meta_queue_add (zebra->mq, rn);

  if (IS_ZEBRA_DEBUG_RIB_Q)
    rnode_debug (rn, "rn %p queued", (void *)rn);

  return;
}

/* Create new meta queue.
   A destructor function doesn't seem to be necessary here.
 */
static struct meta_queue *
meta_queue_new (void)
{
  struct meta_queue *new;
  unsigned i;

  new = XCALLOC (MTYPE_WORK_QUEUE, sizeof (struct meta_queue));
  assert(new);

  for (i = 0; i < MQ_SIZE; i++)
    {
      new->subq[i] = list_new ();
      assert(new->subq[i]);
    }

  return new;
}

/* initialise zebra rib work queue */
static void
rib_queue_init (struct zebra_t *zebra)
{
  assert (zebra);
  
  if (! (zebra->ribq = work_queue_new (zebra->master, 
                                       "route_node processing")))
    {
      zlog_err ("%s: could not initialise work queue!", __func__);
      return;
    }

  /* fill in the work queue spec */
  zebra->ribq->spec.workfunc = &meta_queue_process;
  zebra->ribq->spec.errorfunc = NULL;
  zebra->ribq->spec.completion_func = &meta_queue_process_complete;
  /* XXX: TODO: These should be runtime configurable via vty */
  zebra->ribq->spec.max_retries = 3;
  zebra->ribq->spec.hold = rib_process_hold_time;
  
  if (!(zebra->mq = meta_queue_new ()))
  {
    zlog_err ("%s: could not initialise meta queue!", __func__);
    return;
  }
  return;
}

/* RIB updates are processed via a queue of pointers to route_nodes.
 *
 * The queue length is bounded by the maximal size of the routing table,
 * as a route_node will not be requeued, if already queued.
 *
 * RIBs are submitted via rib_addnode or rib_delnode which set minimal
 * state, or static_install_route (when an existing RIB is updated)
 * and then submit route_node to queue for best-path selection later.
 * Order of add/delete state changes are preserved for any given RIB.
 *
 * Deleted RIBs are reaped during best-path selection.
 *
 * rib_addnode
 * |-> rib_link or unset RIB_ENTRY_REMOVE        |->Update kernel with
 *       |-------->|                             |  best RIB, if required
 *                 |                             |
 * static_install->|->rib_addqueue...... -> rib_process
 *                 |                             |
 *       |-------->|                             |-> rib_unlink
 * |-> set RIB_ENTRY_REMOVE                           |
 * rib_delnode                                  (RIB freed)
 *
 * The 'info' pointer of a route_node points to a rib_dest_t
 * ('dest'). Queueing state for a route_node is kept on the dest. The
 * dest is created on-demand by rib_link() and is kept around at least
 * as long as there are ribs hanging off it (@see rib_gc_dest()).
 * 
 * Refcounting (aka "locking" throughout the GNU Zebra and Quagga code):
 *
 * - route_nodes: refcounted by:
 *   - dest attached to route_node:
 *     - managed by: rib_link/rib_gc_dest
 *   - route_node processing queue
 *     - managed by: rib_addqueue, rib_process.
 *
 */
 
/* Add RIB to head of the route node. */
static void
rib_link (struct route_node *rn, struct rib *rib)
{
  struct rib *head;
  rib_dest_t *dest;

  assert (rib && rn);
  
  if (IS_ZEBRA_DEBUG_RIB)
    rnode_debug (rn, "rn %p, rib %p", (void *)rn, (void *)rib);

  dest = rib_dest_from_rnode (rn);
  if (!dest)
    {
      if (IS_ZEBRA_DEBUG_RIB)
        rnode_debug (rn, "adding dest to table");

      dest = XCALLOC (MTYPE_RIB_DEST, sizeof (rib_dest_t));
      route_lock_node (rn); /* rn route table reference */
      rn->info = dest;
      dest->rnode = rn;
    }

  head = dest->routes;
  if (head)
    {
      head->prev = rib;
    }
  rib->next = head;
  dest->routes = rib;
  rib_queue_add (&zebrad, rn);
}

static void
rib_addnode (struct route_node *rn, struct rib *rib)
{
  /* RIB node has been un-removed before route-node is processed. 
   * route_node must hence already be on the queue for processing.. 
   */
  if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
    {
      if (IS_ZEBRA_DEBUG_RIB)
        rnode_debug (rn, "rn %p, un-removed rib %p", (void *)rn, (void *)rib);

      UNSET_FLAG (rib->status, RIB_ENTRY_REMOVED);
      return;
    }
  rib_link (rn, rib);
}

/*
 * rib_unlink
 *
 * Detach a rib structure from a route_node.
 *
 * Note that a call to rib_unlink() should be followed by a call to
 * rib_gc_dest() at some point. This allows a rib_dest_t that is no
 * longer required to be deleted.
 */
static void
rib_unlink (struct route_node *rn, struct rib *rib)
{
  rib_dest_t *dest;

  assert (rn && rib);

  if (IS_ZEBRA_DEBUG_RIB)
    rnode_debug (rn, "rn %p, rib %p", (void *)rn, (void *)rib);

  dest = rib_dest_from_rnode (rn);

  if (rib->next)
    rib->next->prev = rib->prev;

  if (rib->prev)
    rib->prev->next = rib->next;
  else
    {
      dest->routes = rib->next;
    }

  /* free RIB and nexthops */
  nexthops_free(rib->nexthop);
  XFREE (MTYPE_RIB, rib);

}

static void
rib_delnode (struct route_node *rn, struct rib *rib)
{
  if (IS_ZEBRA_DEBUG_RIB)
    rnode_debug (rn, "rn %p, rib %p, removing", (void *)rn, (void *)rib);
  SET_FLAG (rib->status, RIB_ENTRY_REMOVED);
  rib_queue_add (&zebrad, rn);
}

int
rib_add_ipv4 (int type, int flags, struct prefix_ipv4 *p, 
              struct in_addr *gate, struct in_addr *src,
              ifindex_t ifindex, vrf_id_t vrf_id, int table_id,
              u_int32_t metric, u_int32_t mtu, u_char distance, safi_t safi)
{
  struct rib *rib;
  struct rib *same = NULL;
  struct route_table *table;
  struct route_node *rn;
  struct nexthop *nexthop;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, safi, vrf_id);
  if (! table)
    return 0;

  /* Make it sure prefixlen is applied to the prefix. */
  apply_mask_ipv4 (p);

  /* Set default distance by route type. */
  if (distance == 0)
    {
      if ((unsigned)type >= array_size(route_info))
        distance = 150;
      else
        distance = route_info[type].distance;

      /* iBGP distance is 200. */
      if (type == ZEBRA_ROUTE_BGP && CHECK_FLAG (flags, ZEBRA_FLAG_IBGP))
        distance = 200;
    }

  /* Lookup route node.*/
  rn = route_node_get (table, (struct prefix *) p);

  /* If same type of route are installed, treat it as a implicit
     withdraw. */
  RNODE_FOREACH_RIB (rn, rib)
    {
      if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
        continue;
      
      if (rib->type != type)
        continue;
      if (rib->type != ZEBRA_ROUTE_CONNECT)
        {
          same = rib;
          break;
        }
      /* Duplicate connected route comes in. */
      else if ((nexthop = rib->nexthop) &&
               nexthop->type == NEXTHOP_TYPE_IFINDEX &&
               nexthop->ifindex == ifindex &&
               !CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
        {
          rib->refcnt++;
          return 0 ;
        }
    }

  /* Allocate new rib structure. */
  rib = XCALLOC (MTYPE_RIB, sizeof (struct rib));
  rib->type = type;
  rib->distance = distance;
  rib->flags = flags;
  rib->metric = metric;
  rib->mtu = mtu;
  rib->vrf_id = vrf_id;
  rib->table = table_id;
  rib->nexthop_num = 0;
  rib->uptime = time (NULL);

  /* Nexthop settings. */
  if (gate)
    {
      if (ifindex)
        rib_nexthop_ipv4_ifindex_add (rib, gate, src, ifindex);
      else
        rib_nexthop_ipv4_add (rib, gate, src);
    }
  else
    rib_nexthop_ifindex_add (rib, ifindex);

  /* If this route is kernel route, set FIB flag to the route. */
  if (type == ZEBRA_ROUTE_KERNEL || type == ZEBRA_ROUTE_CONNECT)
    for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
      SET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);

  /* Link new rib to node.*/
  if (IS_ZEBRA_DEBUG_RIB)
    zlog_debug ("%s: calling rib_addnode (%p, %p)",
               __func__, (void *)rn, (void *)rib);
  rib_addnode (rn, rib);
  
  /* Free implicit route.*/
  if (same)
  {
    if (IS_ZEBRA_DEBUG_RIB)
      zlog_debug ("%s: calling rib_delnode (%p, %p)",
                 __func__, (void *)rn, (void *)rib);
    rib_delnode (rn, same);
  }
  
  route_unlock_node (rn);
  return 0;
}

/* This function dumps the contents of a given RIB entry into
 * standard debug log. Calling function name and IP prefix in
 * question are passed as 1st and 2nd arguments.
 */

void _rib_dump (const char * func,
                union prefix46constptr pp, const struct rib * rib)
{
  const struct prefix *p = pp.p;
  char straddr[PREFIX_STRLEN];
  struct nexthop *nexthop, *tnexthop;
  int recursing;

  zlog_debug ("%s: dumping RIB entry %p for %s vrf %u", func, (void *)rib,
              prefix2str(p, straddr, sizeof(straddr)), rib->vrf_id);
  zlog_debug
  (
    "%s: refcnt == %lu, uptime == %lu, type == %u, table == %d",
    func,
    rib->refcnt,
    (unsigned long) rib->uptime,
    rib->type,
    rib->table
  );
  zlog_debug
  (
    "%s: metric == %u, distance == %u, flags == %u, status == %u",
    func,
    rib->metric,
    rib->distance,
    rib->flags,
    rib->status
  );
  zlog_debug
  (
    "%s: nexthop_num == %u, nexthop_active_num == %u, nexthop_fib_num == %u",
    func,
    rib->nexthop_num,
    rib->nexthop_active_num,
    rib->nexthop_fib_num
  );

  for (ALL_NEXTHOPS_RO(rib->nexthop, nexthop, tnexthop, recursing))
    {
      inet_ntop (p->family, &nexthop->gate, straddr, INET6_ADDRSTRLEN);
      zlog_debug
      (
        "%s: %s %s with flags %s%s%s",
        func,
        (recursing ? "  NH" : "NH"),
        straddr,
        (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE) ? "ACTIVE " : ""),
        (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB) ? "FIB " : ""),
        (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE) ? "RECURSIVE" : "")
      );
    }
  zlog_debug ("%s: dump complete", func);
}

/* This is an exported helper to rtm_read() to dump the strange
 * RIB entry found by rib_lookup_ipv4_route()
 */

void rib_lookup_and_dump (struct prefix_ipv4 * p)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *rib;
  char prefix_buf[INET_ADDRSTRLEN];

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, SAFI_UNICAST, VRF_DEFAULT);
  if (! table)
  {
    zlog_err ("%s: zebra_vrf_table() returned NULL", __func__);
    return;
  }

  /* Scan the RIB table for exactly matching RIB entry. */
  rn = route_node_lookup (table, (struct prefix *) p);

  /* No route for this prefix. */
  if (! rn)
  {
    zlog_debug ("%s: lookup failed for %s", __func__,
                prefix2str((struct prefix*) p, prefix_buf, sizeof(prefix_buf)));
    return;
  }

  /* Unlock node. */
  route_unlock_node (rn);

  /* let's go */
  RNODE_FOREACH_RIB (rn, rib)
  {
    zlog_debug
    (
      "%s: rn %p, rib %p: %s, %s",
      __func__,
      (void *)rn,
      (void *)rib,
      (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED) ? "removed" : "NOT removed"),
      (CHECK_FLAG (rib->flags, ZEBRA_FLAG_SELECTED) ? "selected" : "NOT selected")
    );
    rib_dump (p, rib);
  }
}

int
rib_add_ipv4_multipath (struct prefix_ipv4 *p, struct rib *rib, safi_t safi)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *same;
  struct nexthop *nexthop;
  int ret = 0;
  
  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, safi, rib->vrf_id);
  if (! table)
    return 0;

  /* Make it sure prefixlen is applied to the prefix. */
  apply_mask_ipv4 (p);

  /* Set default distance by route type. */
  if (rib->distance == 0)
    {
      rib->distance = route_info[rib->type].distance;

      /* iBGP distance is 200. */
      if (rib->type == ZEBRA_ROUTE_BGP 
          && CHECK_FLAG (rib->flags, ZEBRA_FLAG_IBGP))
        rib->distance = 200;
    }

  /* Lookup route node.*/
  rn = route_node_get (table, (struct prefix *) p);

  /* If same type of route are installed, treat it as a implicit
     withdraw. */
  RNODE_FOREACH_RIB (rn, same)
    {
      if (CHECK_FLAG (same->status, RIB_ENTRY_REMOVED))
        continue;
      
      if (same->type == rib->type && same->table == rib->table
          && same->type != ZEBRA_ROUTE_CONNECT)
        break;
    }
  
  /* If this route is kernel route, set FIB flag to the route. */
  if (rib->type == ZEBRA_ROUTE_KERNEL || rib->type == ZEBRA_ROUTE_CONNECT)
    for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
      SET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);

  /* Link new rib to node.*/
  rib_addnode (rn, rib);
  ret = 1;
  if (IS_ZEBRA_DEBUG_RIB)
  {
    zlog_debug ("%s: called rib_addnode (%p, %p) on new RIB entry",
                __func__, (void *)rn, (void *)rib);
    rib_dump (p, rib);
  }

  /* Free implicit route.*/
  if (same)
  {
    if (IS_ZEBRA_DEBUG_RIB)
    {
      zlog_debug ("%s: calling rib_delnode (%p, %p) on existing RIB entry",
                  __func__, (void *)rn, (void *)same);
      rib_dump (p, same);
    }
    rib_delnode (rn, same);
    ret = -1;
  }
  
  route_unlock_node (rn);
  return ret;
}

/* XXX factor with rib_delete_ipv6 */
int
rib_delete_ipv4 (int type, int flags, struct prefix_ipv4 *p,
                 struct in_addr *gate, ifindex_t ifindex, 
                 vrf_id_t vrf_id, safi_t safi)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *rib;
  struct rib *fib = NULL;
  struct rib *same = NULL;
  struct nexthop *nexthop, *tnexthop;
  int recursing;
  char buf1[PREFIX_STRLEN];
  char buf2[INET_ADDRSTRLEN];

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP, safi, vrf_id);
  if (! table)
    return 0;

  /* Apply mask. */
  apply_mask_ipv4 (p);

  if (IS_ZEBRA_DEBUG_KERNEL)
    {
      if (gate)
        zlog_debug ("rib_delete_ipv4(): route delete %s vrf %u via %s ifindex %d",
                    prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                    inet_ntoa (*gate),
                    ifindex);
      else
        zlog_debug ("rib_delete_ipv4(): route delete %s vrf %u ifindex %d",
                    prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                    ifindex);
    }

  /* Lookup route node. */
  rn = route_node_lookup (table, (struct prefix *) p);
  if (! rn)
    {
      if (IS_ZEBRA_DEBUG_KERNEL)
        {
          if (gate)
            zlog_debug ("route %s vrf %u via %s ifindex %d doesn't exist in rib",
                       prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                       inet_ntop (AF_INET, gate, buf2, INET_ADDRSTRLEN),
                       ifindex);
          else
            zlog_debug ("route %s vrf %u ifindex %d doesn't exist in rib",
                       prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                       ifindex);
        }
      return ZEBRA_ERR_RTNOEXIST;
    }

  /* Lookup same type route. */
  RNODE_FOREACH_RIB (rn, rib)
    {
      if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
        continue;

      if (CHECK_FLAG (rib->status, RIB_ENTRY_SELECTED_FIB))
        fib = rib;

      if (rib->type != type)
        continue;
      if (rib->type == ZEBRA_ROUTE_CONNECT && (nexthop = rib->nexthop) &&
          nexthop->type == NEXTHOP_TYPE_IFINDEX)
        {
          if (nexthop->ifindex != ifindex)
            continue;
          if (rib->refcnt)
            {
              rib->refcnt--;
              route_unlock_node (rn);
              route_unlock_node (rn);
              return 0;
            }
          same = rib;
          break;
        }
      /* Make sure that the route found has the same gateway. */
      else
        {
          if (gate == NULL)
            {
              same = rib;
              break;
            }
          for (ALL_NEXTHOPS_RO(rib->nexthop, nexthop, tnexthop, recursing))
            if (IPV4_ADDR_SAME (&nexthop->gate.ipv4, gate))
              {
                same = rib;
                break;
              }
          if (same)
            break;
        }
    }
  /* If same type of route can't be found and this message is from
     kernel. */
  if (! same)
    {
      if (fib && type == ZEBRA_ROUTE_KERNEL &&
          CHECK_FLAG(flags, ZEBRA_FLAG_SELFROUTE))
        {
          if (IS_ZEBRA_DEBUG_KERNEL)
            {
              zlog_debug ("Zebra route %s/%d was deleted by others from kernel",
                         inet_ntop (AF_INET, &p->prefix, buf1, INET_ADDRSTRLEN),
                         p->prefixlen);
            }
          /* This means someone else, other than Zebra, has deleted
           * a Zebra router from the kernel. We will add it back */
           rib_update_kernel(rn, NULL, fib);
        }
      else
        {
          if (IS_ZEBRA_DEBUG_KERNEL)
            {
              if (gate)
                zlog_debug ("route %s vrf %u via %s ifindex %d type %d "
                           "doesn't exist in rib",
                           prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                           inet_ntop (AF_INET, gate, buf2, INET_ADDRSTRLEN),
                           ifindex,
                           type);
              else
                zlog_debug ("route %s vrf %u ifindex %d type %d doesn't exist in rib",
                           prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                           ifindex,
                           type);
            }
          route_unlock_node (rn);
          return ZEBRA_ERR_RTNOEXIST;
        }
    }
  
  if (same)
    rib_delnode (rn, same);
  
  route_unlock_node (rn);
  return 0;
}

/* Install static route into rib. */
static void
static_install_route (afi_t afi, safi_t safi, struct prefix *p, struct static_route *si)
{
  struct rib *rib;
  struct route_node *rn;
  struct route_table *table;

  /* Lookup table.  */
  table = zebra_vrf_table (afi, safi, si->vrf_id);
  if (! table)
    return;

  /* Lookup existing route */
  rn = route_node_get (table, p);
  RNODE_FOREACH_RIB (rn, rib)
    {
       if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
         continue;
        
       if (rib->type == ZEBRA_ROUTE_STATIC && rib->distance == si->distance)
         break;
    }

  if (rib)
    {
      /* if tag value changed , update old value in RIB */
      if (rib->tag != si->tag)
        rib->tag = si->tag;

      /* Same distance static route is there.  Update it with new
         nexthop. */
      route_unlock_node (rn);
      switch (si->type)
        {
        case STATIC_IPV4_GATEWAY:
          rib_nexthop_ipv4_add (rib, &si->addr.ipv4, NULL);
          break;
        case STATIC_IPV4_IFNAME:
          rib_nexthop_ifname_add (rib, si->ifname);
          break;
        case STATIC_IPV4_BLACKHOLE:
          rib_nexthop_blackhole_add (rib);
          break;
        case STATIC_IPV6_GATEWAY:
          rib_nexthop_ipv6_add (rib, &si->addr.ipv6);
          break;
        case STATIC_IPV6_IFNAME:
          rib_nexthop_ifname_add (rib, si->ifname);
          break;
        case STATIC_IPV6_GATEWAY_IFNAME:
          rib_nexthop_ipv6_ifname_add (rib, &si->addr.ipv6, si->ifname);
          break;
        }
      rib_queue_add (&zebrad, rn);
    }
  else
    {
      /* This is new static route. */
      rib = XCALLOC (MTYPE_RIB, sizeof (struct rib));
      
      rib->type = ZEBRA_ROUTE_STATIC;
      rib->distance = si->distance;
      rib->metric = 0;
      rib->vrf_id = si->vrf_id;
      rib->table = zebrad.rtm_table_default;
      rib->nexthop_num = 0;
      rib->tag = si->tag;

      switch (si->type)
        {
        case STATIC_IPV4_GATEWAY:
          rib_nexthop_ipv4_add (rib, &si->addr.ipv4, NULL);
          break;
        case STATIC_IPV4_IFNAME:
          rib_nexthop_ifname_add (rib, si->ifname);
          break;
        case STATIC_IPV4_BLACKHOLE:
          rib_nexthop_blackhole_add (rib);
          break;
        case STATIC_IPV6_GATEWAY:
          rib_nexthop_ipv6_add (rib, &si->addr.ipv6);
          break;
        case STATIC_IPV6_IFNAME:
          rib_nexthop_ifname_add (rib, si->ifname);
          break;
        case STATIC_IPV6_GATEWAY_IFNAME:
          rib_nexthop_ipv6_ifname_add (rib, &si->addr.ipv6, si->ifname);
          break;
        }

      /* Save the flags of this static routes (reject, blackhole) */
      rib->flags = si->flags;

      /* Link this rib to the tree. */
      rib_addnode (rn, rib);
    }
}

static int
static_nexthop_same (struct nexthop *nexthop, struct static_route *si)
{
  if (nexthop->type == NEXTHOP_TYPE_IPV4
      && si->type == STATIC_IPV4_GATEWAY
      && IPV4_ADDR_SAME (&nexthop->gate.ipv4, &si->addr.ipv4))
    return 1;
  if (nexthop->type == NEXTHOP_TYPE_IFNAME
      && si->type == STATIC_IPV4_IFNAME
      && strcmp (nexthop->ifname, si->ifname) == 0)
    return 1;
  if (nexthop->type == NEXTHOP_TYPE_BLACKHOLE
      && si->type == STATIC_IPV4_BLACKHOLE)
    return 1;
  if (nexthop->type == NEXTHOP_TYPE_IPV6
      && si->type == STATIC_IPV6_GATEWAY
      && IPV6_ADDR_SAME (&nexthop->gate.ipv6, &si->addr.ipv6))
    return 1;
  if (nexthop->type == NEXTHOP_TYPE_IFNAME
      && si->type == STATIC_IPV6_IFNAME
      && strcmp (nexthop->ifname, si->ifname) == 0)
    return 1;
  if (nexthop->type == NEXTHOP_TYPE_IPV6_IFNAME
      && si->type == STATIC_IPV6_GATEWAY_IFNAME
      && IPV6_ADDR_SAME (&nexthop->gate.ipv6, &si->addr.ipv6)
      && strcmp (nexthop->ifname, si->ifname) == 0)
    return 1;
  return 0;
}

/* Uninstall static route from RIB. */
static void
static_uninstall_route (afi_t afi, safi_t safi, struct prefix *p, struct static_route *si)
{
  struct route_node *rn;
  struct rib *rib;
  struct nexthop *nexthop;
  struct route_table *table;

  /* Lookup table.  */
  table = zebra_vrf_table (afi, safi, si->vrf_id);
  if (! table)
    return;
  
  /* Lookup existing route with type and distance. */
  rn = route_node_lookup (table, p);
  if (! rn)
    return;

  RNODE_FOREACH_RIB (rn, rib)
    {
      if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
        continue;

      if (rib->type == ZEBRA_ROUTE_STATIC && rib->distance == si->distance &&
          rib->tag == si->tag)
        break;
    }

  if (! rib)
    {
      route_unlock_node (rn);
      return;
    }

  /* Lookup nexthop. */
  for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
    if (static_nexthop_same (nexthop, si))
      break;

  /* Can't find nexthop. */
  if (! nexthop)
    {
      route_unlock_node (rn);
      return;
    }
  
  /* Check nexthop. */
  if (rib->nexthop_num == 1)
    rib_delnode (rn, rib);
  else
    {
      if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB))
        rib_uninstall (rn, rib);
      rib_nexthop_delete (rib, nexthop);
      nexthop_free (nexthop);
      rib_queue_add (&zebrad, rn);
    }
  /* Unlock node. */
  route_unlock_node (rn);
}

int
static_add_ipv4_safi (safi_t safi, struct prefix *p, struct in_addr *gate,
                      const char *ifname, u_char flags, route_tag_t tag,
                      u_char distance, vrf_id_t vrf_id)
{
  u_char type = 0;
  struct route_node *rn;
  struct static_route *si;
  struct static_route *pp;
  struct static_route *cp;
  struct static_route *update = NULL;
  struct zebra_vrf *zvrf = vrf_info_get (vrf_id);
  struct route_table *stable = zvrf->stable[AFI_IP][safi];

  if (! stable)
    return -1;
  
  /* Lookup static route prefix. */
  rn = route_node_get (stable, p);

  /* Make flags. */
  if (gate)
    type = STATIC_IPV4_GATEWAY;
  else if (ifname)
    type = STATIC_IPV4_IFNAME;
  else
    type = STATIC_IPV4_BLACKHOLE;

  /* Do nothing if there is a same static route.  */
  for (si = rn->info; si; si = si->next)
    {
      if (type == si->type
          && (! gate || IPV4_ADDR_SAME (gate, &si->addr.ipv4))
          && (! ifname || strcmp (ifname, si->ifname) == 0))
        {
          if (distance == si->distance &&
              tag == si->tag)
            {
              route_unlock_node (rn);
              return 0;
            }
          else
            update = si;
        }
    }

  /* Distance or tag changed. */
  if (update)
    static_delete_ipv4_safi (safi, p, gate, ifname, update->tag, update->distance, vrf_id);

  /* Make new static route structure. */
  si = XCALLOC (MTYPE_STATIC_ROUTE, sizeof (struct static_route));

  si->type = type;
  si->distance = distance;
  si->tag = tag;
  si->flags = flags;
  si->vrf_id = vrf_id;

  if (gate)
    si->addr.ipv4 = *gate;
  if (ifname)
    si->ifname = XSTRDUP (MTYPE_TMP, ifname);

  /* Add new static route information to the tree with sort by
     distance value and gateway address. */
  for (pp = NULL, cp = rn->info; cp; pp = cp, cp = cp->next)
    {
      if (si->distance < cp->distance)
        break;
      if (si->distance > cp->distance)
        continue;
      if (si->type == STATIC_IPV4_GATEWAY && cp->type == STATIC_IPV4_GATEWAY)
        {
          if (ntohl (si->addr.ipv4.s_addr) < ntohl (cp->addr.ipv4.s_addr))
            break;
          if (ntohl (si->addr.ipv4.s_addr) > ntohl (cp->addr.ipv4.s_addr))
            continue;
        }
    }

  /* Make linked list. */
  if (pp)
    pp->next = si;
  else
    rn->info = si;
  if (cp)
    cp->prev = si;
  si->prev = pp;
  si->next = cp;

  /* Install into rib. */
  static_install_route (AFI_IP, safi, p, si);

  return 1;
}

int
static_delete_ipv4_safi (safi_t safi, struct prefix *p, struct in_addr *gate,
                         const char *ifname, route_tag_t tag, u_char distance,
                         vrf_id_t vrf_id)
{
  u_char type = 0;
  struct route_node *rn;
  struct static_route *si;
  struct route_table *stable;

  /* Lookup table.  */
  stable = zebra_vrf_static_table (AFI_IP, safi, vrf_id);
  if (! stable)
    return -1;

  /* Lookup static route prefix. */
  rn = route_node_lookup (stable, p);
  if (! rn)
    return 0;

  /* Make flags. */
  if (gate)
    type = STATIC_IPV4_GATEWAY;
  else if (ifname)
    type = STATIC_IPV4_IFNAME;
  else
    type = STATIC_IPV4_BLACKHOLE;

  /* Find same static route is the tree */
  for (si = rn->info; si; si = si->next)
    if (type == si->type
        && (! gate || IPV4_ADDR_SAME (gate, &si->addr.ipv4))
        && (! ifname || strcmp (ifname, si->ifname) == 0)
        && (! tag || (tag == si->tag)))
      break;

  /* Can't find static route. */
  if (! si)
    {
      route_unlock_node (rn);
      return 0;
    }

  /* Install into rib. */
  static_uninstall_route (AFI_IP, safi, p, si);

  /* Unlink static route from linked list. */
  if (si->prev)
    si->prev->next = si->next;
  else
    rn->info = si->next;
  if (si->next)
    si->next->prev = si->prev;
  route_unlock_node (rn);
  
  /* Free static route configuration. */
  if (ifname)
    XFREE (0, si->ifname);
  XFREE (MTYPE_STATIC_ROUTE, si);

  route_unlock_node (rn);

  return 1;
}

int
rib_add_ipv6 (int type, int flags, struct prefix_ipv6 *p,
              struct in6_addr *gate, ifindex_t ifindex,
              vrf_id_t vrf_id, int table_id,
              u_int32_t metric, u_int32_t mtu, u_char distance, safi_t safi)
{
  struct rib *rib;
  struct rib *same = NULL;
  struct route_table *table;
  struct route_node *rn;
  struct nexthop *nexthop;

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP6, safi, vrf_id);
  if (! table)
    return 0;

  /* Make sure mask is applied. */
  apply_mask_ipv6 (p);

  /* Set default distance by route type. */
  if (!distance)
    distance = route_info[type].distance;
  
  if (type == ZEBRA_ROUTE_BGP && CHECK_FLAG (flags, ZEBRA_FLAG_IBGP))
    distance = 200;

  /* Lookup route node.*/
  rn = route_node_get (table, (struct prefix *) p);

  /* If same type of route are installed, treat it as a implicit
     withdraw. */
  RNODE_FOREACH_RIB (rn, rib)
    {
      if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
        continue;

      if (rib->type != type)
        continue;
      if (rib->type != ZEBRA_ROUTE_CONNECT)
        {
          same = rib;
          break;
        }
      else if ((nexthop = rib->nexthop) &&
               nexthop->type == NEXTHOP_TYPE_IFINDEX &&
               nexthop->ifindex == ifindex)
        {
          rib->refcnt++;
          return 0;
        }
    }

  /* Allocate new rib structure. */
  rib = XCALLOC (MTYPE_RIB, sizeof (struct rib));
  
  rib->type = type;
  rib->distance = distance;
  rib->flags = flags;
  rib->metric = metric;
  rib->mtu = mtu;
  rib->vrf_id = vrf_id;
  rib->table = table_id;
  rib->nexthop_num = 0;
  rib->uptime = time (NULL);

  /* Nexthop settings. */
  if (gate)
    {
      if (ifindex)
        rib_nexthop_ipv6_ifindex_add (rib, gate, ifindex);
      else
        rib_nexthop_ipv6_add (rib, gate);
    }
  else
    rib_nexthop_ifindex_add (rib, ifindex);

  /* If this route is kernel route, set FIB flag to the route. */
  if (type == ZEBRA_ROUTE_KERNEL || type == ZEBRA_ROUTE_CONNECT)
    for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
      SET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);

  /* Link new rib to node.*/
  rib_addnode (rn, rib);
  if (IS_ZEBRA_DEBUG_RIB)
  {
    zlog_debug ("%s: called rib_addnode (%p, %p) on new RIB entry",
      __func__, (void *)rn, (void *)rib);
    rib_dump (p, rib);
  }

  /* Free implicit route.*/
  if (same)
  {
    if (IS_ZEBRA_DEBUG_RIB)
    {
      zlog_debug ("%s: calling rib_delnode (%p, %p) on existing RIB entry",
        __func__, (void *)rn, (void *)same);
      rib_dump (p, same);
    }
    rib_delnode (rn, same);
  }
  
  route_unlock_node (rn);
  return 0;
}

int
rib_add_ipv6_multipath (struct prefix_ipv6 *p, struct rib *rib, safi_t safi)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *same = NULL;
  struct nexthop *nexthop;
  int ret = 0;

  if (!rib)
    return 0;                   /* why are we getting called with NULL rib */

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP6, safi, rib->vrf_id);

  if (! table)
    return 0;

  /* Make sure mask is applied. */
  apply_mask_ipv6 (p);

  /* Set default distance by route type. */
  if (rib->distance == 0)
    {
      rib->distance = route_info[rib->type].distance;

      /* iBGP distance is 200. */
      if (rib->type == ZEBRA_ROUTE_BGP
          && CHECK_FLAG (rib->flags, ZEBRA_FLAG_IBGP))
        rib->distance = 200;
    }

  /* Lookup route node.*/
  rn = route_node_get (table, (struct prefix *) p);

  /* If same type of route are installed, treat it as a implicit
     withdraw. */
  RNODE_FOREACH_RIB (rn, same) {
     if (CHECK_FLAG (same->status, RIB_ENTRY_REMOVED)) {
       continue;
     }
     if (same->type != rib->type) {
       continue;
     }

     if (same->table != rib->table) {
       continue;
     }
     if (same->type != ZEBRA_ROUTE_CONNECT) {
       break;
     }
  }

  /* If this route is kernel route, set FIB flag to the route. */
  if (rib->type == ZEBRA_ROUTE_KERNEL || rib->type == ZEBRA_ROUTE_CONNECT) {
    for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next) {
      SET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);
    }
  }

  /* Link new rib to node.*/
  rib_addnode (rn, rib);
  ret = 1;
  /* Free implicit route.*/
  if (same)
  {
    if (IS_ZEBRA_DEBUG_RIB)
    {
      zlog_debug ("%s: calling rib_delnode (%p, %p) on existing RIB entry",
        __func__, rn, same);
      rib_dump ((struct prefix *)p, same);
    }
    rib_delnode (rn, same);
    ret = -1;
  }

  route_unlock_node (rn);
  return ret;
}

/* XXX factor with rib_delete_ipv6 */
int
rib_delete_ipv6 (int type, int flags, struct prefix_ipv6 *p,
                 struct in6_addr *gate, ifindex_t ifindex,
                 vrf_id_t vrf_id, safi_t safi)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *rib;
  struct rib *fib = NULL;
  struct rib *same = NULL;
  struct nexthop *nexthop, *tnexthop;
  int recursing;
  char buf1[PREFIX_STRLEN];
  char buf2[INET6_ADDRSTRLEN];

  /* Apply mask. */
  apply_mask_ipv6 (p);

  /* Lookup table.  */
  table = zebra_vrf_table (AFI_IP6, safi, vrf_id);
  if (! table)
    return 0;
  
  /* Lookup route node. */
  rn = route_node_lookup (table, (struct prefix *) p);
  if (! rn)
    {
      if (IS_ZEBRA_DEBUG_KERNEL)
        {
          if (gate)
            zlog_debug ("route %s vrf %u via %s ifindex %d doesn't exist in rib",
                       prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                       inet_ntop (AF_INET6, gate, buf2, INET6_ADDRSTRLEN),
                       ifindex);
          else
            zlog_debug ("route %s vrf %u ifindex %d doesn't exist in rib",
                       prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                       ifindex);
        }
      return ZEBRA_ERR_RTNOEXIST;
    }

  /* Lookup same type route. */
  RNODE_FOREACH_RIB (rn, rib)
    {
      if (CHECK_FLAG(rib->status, RIB_ENTRY_REMOVED))
        continue;

      if (CHECK_FLAG (rib->status, RIB_ENTRY_SELECTED_FIB))
        fib = rib;

      if (rib->type != type)
        continue;
      if (rib->type == ZEBRA_ROUTE_CONNECT && (nexthop = rib->nexthop) &&
          nexthop->type == NEXTHOP_TYPE_IFINDEX)
        {
          if (nexthop->ifindex != ifindex)
            continue;
          if (rib->refcnt)
            {
              rib->refcnt--;
              route_unlock_node (rn);
              route_unlock_node (rn);
              return 0;
            }
          same = rib;
          break;
        }
      /* Make sure that the route found has the same gateway. */
      else
        {
          if (gate == NULL)
            {
              same = rib;
              break;
            }
          for (ALL_NEXTHOPS_RO(rib->nexthop, nexthop, tnexthop, recursing))
            if (IPV6_ADDR_SAME (&nexthop->gate.ipv6, gate))
              {
                same = rib;
                break;
              }
          if (same)
            break;
        }
    }

  /* If same type of route can't be found and this message is from
     kernel. */
  if (! same)
    {
      if (fib && type == ZEBRA_ROUTE_KERNEL &&
          CHECK_FLAG(flags, ZEBRA_FLAG_SELFROUTE))
        {
          if (IS_ZEBRA_DEBUG_KERNEL)
            {
              zlog_debug ("Zebra route %s/%d was deleted by others from kernel",
                         inet_ntop (AF_INET, &p->prefix, buf1, INET_ADDRSTRLEN),
                         p->prefixlen);
            }
          /* This means someone else, other than Zebra, has deleted a Zebra
           * route from the kernel. We will add it back */
          rib_update_kernel(rn, NULL, fib);
        }
      else
        {
          if (IS_ZEBRA_DEBUG_KERNEL)
            {
              if (gate)
                zlog_debug ("route %s vrf %u via %s ifindex %d type %d "
                           "doesn't exist in rib",
                           prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                           inet_ntop (AF_INET6, gate, buf2, INET6_ADDRSTRLEN),
                           ifindex,
                           type);
              else
                zlog_debug ("route %s vrf %u ifindex %d type %d doesn't exist in rib",
                           prefix2str (p, buf1, sizeof(buf1)), vrf_id,
                           ifindex,
                           type);
            }
          route_unlock_node (rn);
          return ZEBRA_ERR_RTNOEXIST;
        }
    }

  if (same)
    rib_delnode (rn, same);
  
  route_unlock_node (rn);
  return 0;
}

/* Add static route into static route configuration. */
int
static_add_ipv6 (struct prefix *p, u_char type, struct in6_addr *gate,
                 const char *ifname, u_char flags, route_tag_t tag,
                 u_char distance, vrf_id_t vrf_id)
{
  struct route_node *rn;
  struct static_route *si;
  struct static_route *pp;
  struct static_route *cp;
  struct static_route *update = NULL;
  struct zebra_vrf *zvrf = vrf_info_get (vrf_id);
  struct route_table *stable = zvrf->stable[AFI_IP6][SAFI_UNICAST];

  if (! stable)
    return -1;
    
  if (!gate &&
      (type == STATIC_IPV6_GATEWAY || type == STATIC_IPV6_GATEWAY_IFNAME))
    return -1;
  
  if (!ifname && 
      (type == STATIC_IPV6_GATEWAY_IFNAME || type == STATIC_IPV6_IFNAME))
    return -1;

  /* Lookup static route prefix. */
  rn = route_node_get (stable, p);

  /* Do nothing if there is a same static route.  */
  for (si = rn->info; si; si = si->next)
    {
      if (type == si->type
          && tag == si->tag
          && (! gate || IPV6_ADDR_SAME (gate, &si->addr.ipv6))
          && (! ifname || strcmp (ifname, si->ifname) == 0))
        {
          if (distance == si->distance)
            {
              route_unlock_node (rn);
              return 0;
            }
          else
            update = si;
        }
    }

  if (update)
    static_delete_ipv6(p, type, gate, ifname, tag, update->distance, vrf_id);

  /* Make new static route structure. */
  si = XCALLOC (MTYPE_STATIC_ROUTE, sizeof (struct static_route));

  si->type = type;
  si->distance = distance;
  si->tag = tag;
  si->flags = flags;
  si->vrf_id = vrf_id;

  switch (type)
    {
    case STATIC_IPV6_GATEWAY:
      si->addr.ipv6 = *gate;
      break;
    case STATIC_IPV6_IFNAME:
      si->ifname = XSTRDUP (MTYPE_TMP, ifname);
      break;
    case STATIC_IPV6_GATEWAY_IFNAME:
      si->addr.ipv6 = *gate;
      si->ifname = XSTRDUP (MTYPE_TMP, ifname);
      break;
    }

  /* Add new static route information to the tree with sort by
     distance value and gateway address. */
  for (pp = NULL, cp = rn->info; cp; pp = cp, cp = cp->next)
    {
      if (si->distance < cp->distance)
        break;
      if (si->distance > cp->distance)
        continue;
    }

  /* Make linked list. */
  if (pp)
    pp->next = si;
  else
    rn->info = si;
  if (cp)
    cp->prev = si;
  si->prev = pp;
  si->next = cp;

  /* Install into rib. */
  static_install_route (AFI_IP6, SAFI_UNICAST, p, si);

  return 1;
}

/* Delete static route from static route configuration. */
int
static_delete_ipv6 (struct prefix *p, u_char type, struct in6_addr *gate,
                    const char *ifname, route_tag_t tag, u_char distance,
                    vrf_id_t vrf_id)
{
  struct route_node *rn;
  struct static_route *si;
  struct route_table *stable;

  /* Lookup table.  */
  stable = zebra_vrf_static_table (AFI_IP6, SAFI_UNICAST, vrf_id);
  if (! stable)
    return -1;

  /* Lookup static route prefix. */
  rn = route_node_lookup (stable, p);
  if (! rn)
    return 0;

  /* Find same static route is the tree */
  for (si = rn->info; si; si = si->next)
    if (distance == si->distance 
        && type == si->type
        && (! gate || IPV6_ADDR_SAME (gate, &si->addr.ipv6))
        && (! ifname || strcmp (ifname, si->ifname) == 0)
        && (! tag || (tag == si->tag)))
      break;

  /* Can't find static route. */
  if (! si)
    {
      route_unlock_node (rn);
      return 0;
    }

  /* Install into rib. */
  static_uninstall_route (AFI_IP6, SAFI_UNICAST, p, si);

  /* Unlink static route from linked list. */
  if (si->prev)
    si->prev->next = si->next;
  else
    rn->info = si->next;
  if (si->next)
    si->next->prev = si->prev;
  
  /* Free static route configuration. */
  if (ifname)
    XFREE (0, si->ifname);
  XFREE (MTYPE_STATIC_ROUTE, si);

  return 1;
}

/* RIB update function. */
void
rib_update (vrf_id_t vrf_id)
{
  struct route_node *rn;
  struct route_table *table;
  
  table = zebra_vrf_table (AFI_IP, SAFI_UNICAST, vrf_id);
  if (table)
    for (rn = route_top (table); rn; rn = route_next (rn))
      if (rnode_to_ribs (rn))
        rib_queue_add (&zebrad, rn);

  table = zebra_vrf_table (AFI_IP6, SAFI_UNICAST, vrf_id);
  if (table)
    for (rn = route_top (table); rn; rn = route_next (rn))
      if (rnode_to_ribs (rn))
        rib_queue_add (&zebrad, rn);
}


/* Remove all routes which comes from non main table.  */
static void
rib_weed_table (struct route_table *table)
{
  struct route_node *rn;
  struct rib *rib;
  struct rib *next;

  if (table)
    for (rn = route_top (table); rn; rn = route_next (rn))
      RNODE_FOREACH_RIB_SAFE (rn, rib, next)
        {
          if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
            continue;

          if (rib->table != zebrad.rtm_table_default &&
              rib->table != RT_TABLE_MAIN)
            rib_delnode (rn, rib);
        }
}

/* Delete all routes from non main table. */
void
rib_weed_tables (void)
{
  vrf_iter_t iter;
  struct zebra_vrf *zvrf;

  for (iter = vrf_first (); iter != VRF_ITER_INVALID; iter = vrf_next (iter))
    if ((zvrf = vrf_iter2info (iter)) != NULL)
      {
        rib_weed_table (zvrf->table[AFI_IP][SAFI_UNICAST]);
        rib_weed_table (zvrf->table[AFI_IP6][SAFI_UNICAST]);
      }
}

#if 0
/* Delete self installed routes after zebra is relaunched.  */
static void
rib_sweep_table (struct route_table *table)
{
  struct route_node *rn;
  struct rib *rib;
  struct rib *next;
  int ret = 0;

  if (table)
    for (rn = route_top (table); rn; rn = route_next (rn))
      RNODE_FOREACH_RIB_SAFE (rn, rib, next)
        {
          if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
            continue;

          if (rib->type == ZEBRA_ROUTE_KERNEL && 
              CHECK_FLAG (rib->flags, ZEBRA_FLAG_SELFROUTE))
            {
              ret = rib_update_kernel (rn, rib, NULL);
              if (! ret)
                rib_delnode (rn, rib);
            }
        }
}
#endif

/* Sweep all RIB tables.  */
void
rib_sweep_route (void)
{
  vrf_iter_t iter;
  struct zebra_vrf *zvrf;

  for (iter = vrf_first (); iter != VRF_ITER_INVALID; iter = vrf_next (iter))
    if ((zvrf = vrf_iter2info (iter)) != NULL)
      {
        rib_weed_table (zvrf->table[AFI_IP][SAFI_UNICAST]);
        rib_weed_table (zvrf->table[AFI_IP6][SAFI_UNICAST]);
      }
}

/* Remove specific by protocol routes from 'table'. */
static unsigned long
rib_score_proto_table (u_char proto, struct route_table *table)
{
  struct route_node *rn;
  struct rib *rib;
  struct rib *next;
  unsigned long n = 0;

  if (table)
    for (rn = route_top (table); rn; rn = route_next (rn))
      RNODE_FOREACH_RIB_SAFE (rn, rib, next)
        {
          if (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED))
            continue;
          if (rib->type == proto)
            {
              rib_delnode (rn, rib);
              n++;
            }
        }

  return n;
}

/* Remove specific by protocol routes. */
unsigned long
rib_score_proto (u_char proto)
{
  vrf_iter_t iter;
  struct zebra_vrf *zvrf;
  unsigned long cnt = 0;

  for (iter = vrf_first (); iter != VRF_ITER_INVALID; iter = vrf_next (iter))
    if ((zvrf = vrf_iter2info (iter)) != NULL)
      cnt += rib_score_proto_table (proto, zvrf->table[AFI_IP][SAFI_UNICAST])
            +rib_score_proto_table (proto, zvrf->table[AFI_IP6][SAFI_UNICAST]);

  return cnt;
}

/* Close RIB and clean up kernel routes. */
void
rib_close_table (struct route_table *table)
{
  struct route_node *rn;
  rib_table_info_t *info = table->info;
  struct rib *rib;

  if (table)
    for (rn = route_top (table); rn; rn = route_next (rn))
      RNODE_FOREACH_RIB (rn, rib)
        {
          if (!CHECK_FLAG (rib->status, RIB_ENTRY_SELECTED_FIB))
            continue;

          if (info->safi == SAFI_UNICAST)
            zfpm_trigger_update (rn, NULL);

          if (! RIB_SYSTEM_ROUTE (rib))
            rib_update_kernel (rn, rib, NULL);
        }
}

/* Close all RIB tables.  */
void
rib_close (void)
{
  vrf_iter_t iter;
  struct zebra_vrf *zvrf;

  for (iter = vrf_first (); iter != VRF_ITER_INVALID; iter = vrf_next (iter))
    if ((zvrf = vrf_iter2info (iter)) != NULL)
      {
        rib_close_table (zvrf->table[AFI_IP][SAFI_UNICAST]);
        rib_close_table (zvrf->table[AFI_IP6][SAFI_UNICAST]);
      }
}

/* Routing information base initialize. */
void
rib_init (void)
{
  rib_queue_init (&zebrad);
}

/*
 * vrf_id_get_next
 *
 * Get the first vrf id that is greater than the given vrf id if any.
 *
 * Returns TRUE if a vrf id was found, FALSE otherwise.
 */
static inline int
vrf_id_get_next (vrf_id_t vrf_id, vrf_id_t *next_id_p)
{
  vrf_iter_t iter = vrf_iterator (vrf_id);
  struct zebra_vrf *zvrf = vrf_iter2info (iter);

  /* The same one ? Then find out the next. */
  if (zvrf && (zvrf->vrf_id == vrf_id))
    zvrf = vrf_iter2info (vrf_next (iter));

  if (zvrf)
    {
      *next_id_p = zvrf->vrf_id;
      return 1;
    }

  return 0;
}

/*
 * rib_tables_iter_next
 *
 * Returns the next table in the iteration.
 */
struct route_table *
rib_tables_iter_next (rib_tables_iter_t *iter)
{
  struct route_table *table;

  /*
   * Array that helps us go over all AFI/SAFI combinations via one
   * index.
   */
  static struct {
    afi_t afi;
    safi_t safi;
  } afi_safis[] = {
    { AFI_IP, SAFI_UNICAST },
    { AFI_IP, SAFI_MULTICAST },
    { AFI_IP6, SAFI_UNICAST },
    { AFI_IP6, SAFI_MULTICAST },
  };

  table = NULL;

  switch (iter->state)
    {

    case RIB_TABLES_ITER_S_INIT:
      iter->vrf_id = VRF_DEFAULT;
      iter->afi_safi_ix = -1;

      /* Fall through */

    case RIB_TABLES_ITER_S_ITERATING:
      iter->afi_safi_ix++;
      while (1)
        {

          while (iter->afi_safi_ix < (int) ZEBRA_NUM_OF (afi_safis))
            {
              table = zebra_vrf_table (afi_safis[iter->afi_safi_ix].afi,
                                 afi_safis[iter->afi_safi_ix].safi,
                                 iter->vrf_id);
              if (table)
                break;

              iter->afi_safi_ix++;
            }

          /*
           * Found another table in this vrf.
           */
          if (table)
            break;

          /*
           * Done with all tables in the current vrf, go to the next
           * one.
           */
          if (!vrf_id_get_next (iter->vrf_id, &iter->vrf_id))
            break;

          iter->afi_safi_ix = 0;
        }

      break;

    case RIB_TABLES_ITER_S_DONE:
      return NULL;
    }

  if (table)
    iter->state = RIB_TABLES_ITER_S_ITERATING;
  else
    iter->state = RIB_TABLES_ITER_S_DONE;

  return table;
}

/* Lookup VRF by identifier.  */
struct zebra_vrf *
zebra_vrf_lookup (vrf_id_t vrf_id)
{
  return vrf_info_lookup (vrf_id);
}

/*
 * Create a routing table for the specific AFI/SAFI in the given VRF.
 */
static void
zebra_vrf_table_create (struct zebra_vrf *zvrf, afi_t afi, safi_t safi)
{
  rib_table_info_t *info;
  struct route_table *table;

  assert (!zvrf->table[afi][safi]);

  table = route_table_init ();
  zvrf->table[afi][safi] = table;

  info = XCALLOC (MTYPE_RIB_TABLE_INFO, sizeof (*info));
  info->zvrf = zvrf;
  info->afi = afi;
  info->safi = safi;
  table->info = info;
}

/* Allocate new zebra VRF. */
struct zebra_vrf *
zebra_vrf_alloc (vrf_id_t vrf_id)
{
  struct zebra_vrf *zvrf;
#ifdef HAVE_NETLINK
  char nl_name[64];
#endif

  zvrf = XCALLOC (MTYPE_ZEBRA_VRF, sizeof (struct zebra_vrf));

  /* Allocate routing table and static table.  */
  zebra_vrf_table_create (zvrf, AFI_IP, SAFI_UNICAST);
  zebra_vrf_table_create (zvrf, AFI_IP6, SAFI_UNICAST);
  zvrf->stable[AFI_IP][SAFI_UNICAST] = route_table_init ();
  zvrf->stable[AFI_IP6][SAFI_UNICAST] = route_table_init ();
  zebra_vrf_table_create (zvrf, AFI_IP, SAFI_MULTICAST);
  zebra_vrf_table_create (zvrf, AFI_IP6, SAFI_MULTICAST);
  zvrf->stable[AFI_IP][SAFI_MULTICAST] = route_table_init ();
  zvrf->stable[AFI_IP6][SAFI_MULTICAST] = route_table_init ();

  zvrf->rnh_table[AFI_IP] = route_table_init();
  zvrf->rnh_table[AFI_IP6] = route_table_init();

  /* Set VRF ID */
  zvrf->vrf_id = vrf_id;

#ifdef HAVE_NETLINK
  /* Initialize netlink sockets */
  snprintf (nl_name, 64, "netlink-listen (vrf %u)", vrf_id);
  zvrf->netlink.sock = -1;
  zvrf->netlink.name = XSTRDUP (MTYPE_NETLINK_NAME, nl_name);

  snprintf (nl_name, 64, "netlink-cmd (vrf %u)", vrf_id);
  zvrf->netlink_cmd.sock = -1;
  zvrf->netlink_cmd.name = XSTRDUP (MTYPE_NETLINK_NAME, nl_name);
#endif

  return zvrf;
}

/* Lookup the routing table in an enabled VRF. */
struct route_table *
zebra_vrf_table (afi_t afi, safi_t safi, vrf_id_t vrf_id)
{
  struct zebra_vrf *zvrf = vrf_info_lookup (vrf_id);

  if (!zvrf)
    return NULL;

  if (afi >= AFI_MAX || safi >= SAFI_MAX)
    return NULL;

  return zvrf->table[afi][safi];
}

/* Lookup the static routing table in a VRF. */
struct route_table *
zebra_vrf_static_table (afi_t afi, safi_t safi, vrf_id_t vrf_id)
{
  struct zebra_vrf *zvrf = vrf_info_lookup (vrf_id);

  if (!zvrf)
    return NULL;

  if (afi >= AFI_MAX || safi >= SAFI_MAX)
    return NULL;

  return zvrf->stable[afi][safi];
}