/*
 * Routing Table
 * Copyright (C) 1998 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.  
 */

#ifndef _ZEBRA_TABLE_H
#define _ZEBRA_TABLE_H

/*
 * Forward declarations.
 */
struct route_node;
struct route_table;

/*
 * route_table_delegate_t
 *
 * Function vector that can be used by a client to customize the
 * behavior of one or more route tables.
 */
typedef struct route_table_delegate_t_ route_table_delegate_t;

typedef struct route_node * (*route_table_create_node_func_t) 
  (route_table_delegate_t *, struct route_table *);

typedef void (*route_table_destroy_node_func_t) 
  (route_table_delegate_t *, struct route_table *, struct route_node *);

struct route_table_delegate_t_ 
{
  route_table_create_node_func_t create_node;
  route_table_destroy_node_func_t destroy_node;
};

/* Routing table top structure. */
struct route_table
{
  struct route_node *top;

  /*
   * Delegate that performs certain functions for this table.
   */
  route_table_delegate_t *delegate;
  
  unsigned long count;
  
  /*
   * User data.
   */
  void *info;
};

/*
 * Macro that defines all fields in a route node.
 */
#define ROUTE_NODE_FIELDS			\
  /* Actual prefix of this radix. */		\
  struct prefix p;				\
						\
  /* Tree link. */				\
  struct route_table *table;			\
  struct route_node *parent;			\
  struct route_node *link[2];			\
						\
  /* Lock of this radix */			\
  unsigned int lock;				\
						\
  /* Each node of route. */			\
  void *info;					\
						\
  /* Aggregation. */				\
  void *aggregate;


/* Each routing entry. */
struct route_node
{
  ROUTE_NODE_FIELDS

#define l_left   link[0]
#define l_right  link[1]
};

typedef struct route_table_iter_t_ route_table_iter_t;

typedef enum 
{
  RT_ITER_STATE_INIT,
  RT_ITER_STATE_ITERATING,
  RT_ITER_STATE_PAUSED,
  RT_ITER_STATE_DONE
} route_table_iter_state_t;

/*
 * route_table_iter_t
 * 
 * Structure that holds state for iterating over a route table.
 */
struct route_table_iter_t_ 
{

  route_table_iter_state_t state;

  /*
   * Routing table that we are iterating over. The caller must ensure
   * that that table outlives the iterator.
   */
  struct route_table *table;

  /*
   * The node that the iterator is currently on.
   */
  struct route_node *current;

  /*
   * The last prefix that the iterator processed before it was paused.
   */  
  struct prefix pause_prefix;
};

/* Prototypes. */
extern struct route_table *route_table_init (void);

extern struct route_table *
route_table_init_with_delegate (route_table_delegate_t *);

extern void route_table_finish (struct route_table *);
extern void route_unlock_node (struct route_node *node);
extern struct route_node *route_top (struct route_table *);
extern struct route_node *route_next (struct route_node *);
extern struct route_node *route_next_until (struct route_node *,
                                            struct route_node *);
extern struct route_node *route_node_get (struct route_table *const,
                                          struct prefix *);
extern struct route_node *route_node_lookup (const struct route_table *,
                                             struct prefix *);
extern struct route_node *route_lock_node (struct route_node *node);
extern struct route_node *route_node_match (const struct route_table *,
                                            const struct prefix *);
extern struct route_node *route_node_match_ipv4 (const struct route_table *,
						 const struct in_addr *);
#ifdef HAVE_IPV6
extern struct route_node *route_node_match_ipv6 (const struct route_table *,
						 const struct in6_addr *);
#endif /* HAVE_IPV6 */

extern unsigned long route_table_count (const struct route_table *);

extern struct route_node *
route_table_get_next (const struct route_table *table, struct prefix *p);
extern int
route_table_prefix_iter_cmp (struct prefix *p1, struct prefix *p2);

/*
 * Iterator functions.
 */
extern void route_table_iter_init (route_table_iter_t *iter,
				   struct route_table *table);
extern void route_table_iter_pause (route_table_iter_t *iter);
extern void route_table_iter_cleanup (route_table_iter_t *iter);

/*
 * Inline functions.
 */

/*
 * route_table_iter_next
 *
 * Get the next node in the tree.
 */
static inline struct route_node *
route_table_iter_next (route_table_iter_t * iter)
{
  struct route_node *node;

  switch (iter->state)
    {

    case RT_ITER_STATE_INIT:

      /*
       * We're just starting the iteration.
       */
      node = route_top (iter->table);
      break;

    case RT_ITER_STATE_ITERATING:
      node = route_next (iter->current);
      break;

    case RT_ITER_STATE_PAUSED:

      /*
       * Start with the node following pause_prefix.
       */
      node = route_table_get_next (iter->table, &iter->pause_prefix);
      break;

    case RT_ITER_STATE_DONE:
      return NULL;

    default:
      assert (0);
    }

  iter->current = node;
  if (node)
    iter->state = RT_ITER_STATE_ITERATING;
  else
    iter->state = RT_ITER_STATE_DONE;

  return node;
}

/*
 * route_table_iter_is_done
 *
 * Returns TRUE if the iteration is complete.
 */
static inline int
route_table_iter_is_done (route_table_iter_t *iter)
{
  return iter->state == RT_ITER_STATE_DONE;
}

/*
 * route_table_iter_started
 *
 * Returns TRUE if this iterator has started iterating over the tree.
 */
static inline int
route_table_iter_started (route_table_iter_t *iter)
{
  return iter->state != RT_ITER_STATE_INIT;
}

#endif /* _ZEBRA_TABLE_H */