zebra_rib.c

zebra测试源代码用于 SOCKET 通信

      /* 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 (newhop = match->nexthop; newhop; newhop = newhop->next)
		if (CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_FIB))
		  return match;
	      return NULL;
	    }
	}
    }
  return NULL;
}

struct rib *
rib_lookup_ipv4 (struct prefix_ipv4 *p)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  struct nexthop *nexthop;

  /* Lookup table.  */
  table = vrf_table (AFI_IP, SAFI_UNICAST, 0);
  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);

  /* Pick up selected route. */
  for (match = rn->info; match; match = match->next)
    if (CHECK_FLAG (match->flags, ZEBRA_FLAG_SELECTED))
      break;

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

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

  return NULL;
}

#ifdef HAVE_IPV6
struct rib *
rib_match_ipv6 (struct in6_addr *addr)
{
  struct prefix_ipv6 p;
  struct route_table *table;
  struct route_node *rn;
  struct rib *match;
  struct nexthop *newhop;

  /* Lookup table.  */
  table = vrf_table (AFI_IP6, SAFI_UNICAST, 0);
  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. */
      for (match = rn->info; match; match = match->next)
	if (CHECK_FLAG (match->flags, ZEBRA_FLAG_SELECTED))
	  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 (newhop = match->nexthop; newhop; newhop = newhop->next)
		if (CHECK_FLAG (newhop->flags, NEXTHOP_FLAG_FIB))
		  return match;
	      return NULL;
	    }
	}
    }
  return NULL;
}
#endif /* HAVE_IPV6 */

int
nexthop_active_check (struct route_node *rn, struct rib *rib,
		      struct nexthop *nexthop, int set)
{
  struct interface *ifp;

  switch (nexthop->type)
    {
    case NEXTHOP_TYPE_IFINDEX:
      ifp = if_lookup_by_index (nexthop->ifindex);
      if (ifp && if_is_up (ifp))
	SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      else
	UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      break;
    case NEXTHOP_TYPE_IFNAME:
    case NEXTHOP_TYPE_IPV6_IFNAME:
      ifp = if_lookup_by_name (nexthop->ifname);
      if (ifp && if_is_up (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:
      if (nexthop_active_ipv4 (rib, nexthop, set, rn))
	SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      else
	UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      break;
#ifdef HAVE_IPV6
    case NEXTHOP_TYPE_IPV6:
      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:
      if (IN6_IS_ADDR_LINKLOCAL (&nexthop->gate.ipv6))
	{
	  ifp = if_lookup_by_index (nexthop->ifindex);
	  if (ifp && if_is_up (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;
#endif /* HAVE_IPV6 */
    case NEXTHOP_TYPE_BLACKHOLE:
      SET_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      break;
    default:
      break;
    }
  return CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
}

int
nexthop_active_update (struct route_node *rn, struct rib *rib, int set)
{
  struct nexthop *nexthop;
  int active;

  rib->nexthop_active_num = 0;
  UNSET_FLAG (rib->flags, ZEBRA_FLAG_CHANGED);

  for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
    {
      active = CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE);
      rib->nexthop_active_num += nexthop_active_check (rn, rib, nexthop, set);
      if (active != CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE))
	SET_FLAG (rib->flags, ZEBRA_FLAG_CHANGED);
    }
  return rib->nexthop_active_num;
}

#define RIB_SYSTEM_ROUTE(R) \
        ((R)->type == ZEBRA_ROUTE_KERNEL || (R)->type == ZEBRA_ROUTE_CONNECT)

void
newrib_free (struct rib *rib)
{
  struct nexthop *nexthop;
  struct nexthop *next;

  for (nexthop = rib->nexthop; nexthop; nexthop = next)
    {
      next = nexthop->next;
      nexthop_free (nexthop);
    }
  XFREE (MTYPE_RIB, rib);
}

void
rib_install_kernel (struct route_node *rn, struct rib *rib)
{
  int ret = 0;
  struct nexthop *nexthop;

  switch (PREFIX_FAMILY (&rn->p))
    {
    case AF_INET:
      ret = kernel_add_ipv4 (&rn->p, rib);
      break;
#ifdef HAVE_IPV6
    case AF_INET6:
      ret = kernel_add_ipv6 (&rn->p, rib);
      break;
#endif /* HAVE_IPV6 */
    }

  if (ret < 0)
    {
      for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
	UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);
    }
}

/* Uninstall the route from kernel. */
int
rib_uninstall_kernel (struct route_node *rn, struct rib *rib)
{
  int ret = 0;
  struct nexthop *nexthop;

  switch (PREFIX_FAMILY (&rn->p))
    {
    case AF_INET:
      ret = kernel_delete_ipv4 (&rn->p, rib);
      break;
#ifdef HAVE_IPV6
    case AF_INET6:
      ret = kernel_delete_ipv6 (&rn->p, rib);
      break;
#endif /* HAVE_IPV6 */
    }

  for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next)
    UNSET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB);

  return ret;
}

/* Uninstall the route from kernel. */
void
rib_uninstall (struct route_node *rn, struct rib *rib)
{
  if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_SELECTED))
    {
      redistribute_delete (&rn->p, rib);
      if (! RIB_SYSTEM_ROUTE (rib))
	rib_uninstall_kernel (rn, rib);
      UNSET_FLAG (rib->flags, ZEBRA_FLAG_SELECTED);
    }
}

/* Core function for processing routing information base. */
void
rib_process (struct route_node *rn, struct rib *del)
{
  struct rib *rib;
  struct rib *next;
  struct rib *fib = NULL;
  struct rib *select = NULL;

  for (rib = rn->info; rib; rib = next)
    {
      next = rib->next;

      /* Currently installed rib. */
      if (CHECK_FLAG (rib->flags, ZEBRA_FLAG_SELECTED))
	fib = rib;

      /* Skip unreachable nexthop. */
      if (! nexthop_active_update (rn, rib, 0))
	continue;

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

      /* Newly selected rib. */
      if (! select || rib->distance < select->distance 
	  || rib->type == ZEBRA_ROUTE_CONNECT)
	select = rib;
    }

  /* Deleted route check. */
  if (del && CHECK_FLAG (del->flags, ZEBRA_FLAG_SELECTED))
    fib = del;

  /* Same route is selected. */
  if (select && select == fib)
    {
      if (CHECK_FLAG (select->flags, ZEBRA_FLAG_CHANGED))
	{
	  redistribute_delete (&rn->p, select);
	  if (! RIB_SYSTEM_ROUTE (select))
	    rib_uninstall_kernel (rn, select);

	  /* Set real nexthop. */
	  nexthop_active_update (rn, select, 1);
  
	  if (! RIB_SYSTEM_ROUTE (select))
	    rib_install_kernel (rn, select);
	  redistribute_add (&rn->p, select);
	}
      return;
    }

  /* Uninstall old rib from forwarding table. */
  if (fib)
    {
      redistribute_delete (&rn->p, fib);
      if (! RIB_SYSTEM_ROUTE (fib))
	rib_uninstall_kernel (rn, fib);
      UNSET_FLAG (fib->flags, ZEBRA_FLAG_SELECTED);

      /* Set real nexthop. */
      nexthop_active_update (rn, fib, 1);
    }

  /* Install new rib into forwarding table. */
  if (select)
    {
      /* Set real nexthop. */
      nexthop_active_update (rn, select, 1);

      if (! RIB_SYSTEM_ROUTE (select))
	rib_install_kernel (rn, select);
      SET_FLAG (select->flags, ZEBRA_FLAG_SELECTED);
      redistribute_add (&rn->p, select);
    }
}

/* Add RIB to head of the route node. */
void
rib_addnode (struct route_node *rn, struct rib *rib)
{
  struct rib *head;

  head = rn->info;
  if (head)
    head->prev = rib;
  rib->next = head;
  rn->info = rib;
}

void
rib_delnode (struct route_node *rn, struct rib *rib)
{
  if (rib->next)
    rib->next->prev = rib->prev;
  if (rib->prev)
    rib->prev->next = rib->next;
  else
    rn->info = rib->next;
}

int
rib_add_ipv4 (int type, int flags, struct prefix_ipv4 *p, 
	      struct in_addr *gate, unsigned int ifindex, u_int32_t vrf_id,
	      u_int32_t metric, u_char distance)
{
  struct rib *rib;
  struct rib *same = NULL;
  struct route_table *table;
  struct route_node *rn;
  struct nexthop *nexthop;

  /* Lookup table.  */
  table = vrf_table (AFI_IP, SAFI_UNICAST, 0);
  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)
    {
      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. */
  for (rib = rn->info; rib; rib = rib->next)
    {
      if (rib->type == ZEBRA_ROUTE_CONNECT)
	{
	  nexthop = rib->nexthop;

	  /* Duplicate connected route comes in. */
	  if (rib->type == type
	      && nexthop && nexthop->type == NEXTHOP_TYPE_IFINDEX
	      && nexthop->ifindex == ifindex)
	    {
	      rib->refcnt++;
	      return 0 ;
	    }
	}
      else if (rib->type == type)
	{
	  same = rib;
	  rib_delnode (rn, same);
	  route_unlock_node (rn);
	  break;
	}
    }

  /* Allocate new rib structure. */
  rib = XMALLOC (MTYPE_RIB, sizeof (struct rib));
  memset (rib, 0, sizeof (struct rib));
  rib->type = type;
  rib->distance = distance;
  rib->flags = flags;
  rib->metric = metric;
  rib->nexthop_num = 0;
  rib->uptime = time (NULL);

  /* Nexthop settings. */
  if (gate)
    {
      if (ifindex)
	nexthop_ipv4_ifindex_add (rib, gate, ifindex);
      else
	nexthop_ipv4_add (rib, gate);
    }
  else
    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);

  /* Process this route node. */
  rib_process (rn, same);

  /* Free implicit route.*/
  if (same)
    newrib_free (same);

  return 0;
}

int
rib_add_ipv4_multipath (struct prefix_ipv4 *p, struct rib *rib)
{
  struct route_table *table;
  struct route_node *rn;
  struct rib *same;
  struct nexthop *nexthop;

  /* Lookup table.  */
  table = vrf_table (AFI_IP, SAFI_UNICAST, 0);
  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. */
  for (same = rn->info; same; same = same->next)
    {
      if (same->type == rib->type && same->table == rib->table
	  && same->type != ZEBRA_ROUTE_CONNECT)
	{
	  rib_delnode (rn, same);
	  route_unlock_node (rn);
	  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);