/* AS path related definitions.
   Copyright (C) 1997, 98, 99 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 _QUAGGA_BGP_ASPATH_H
#define _QUAGGA_BGP_ASPATH_H

/* AS path segment type.  */
#define AS_SET                       1
#define AS_SEQUENCE                  2
#define AS_CONFED_SEQUENCE           3
#define AS_CONFED_SET                4

/* Private AS range defined in RFC2270.  */
#define BGP_PRIVATE_AS_MIN       64512U
#define BGP_PRIVATE_AS_MAX       65535U

/* Private 4 byte AS range defined in RFC6996.  */
#define BGP_PRIVATE_AS4_MIN     4200000000U
#define BGP_PRIVATE_AS4_MAX     4294967294U

/* we leave BGP_AS_MAX as the 16bit AS MAX number.  */
#define BGP_AS_MAX		     65535U
#define BGP_AS4_MAX		4294967295U
/* Transition 16Bit AS as defined by IANA */
#define BGP_AS_TRANS		 23456U

#define BGP_AS_IS_PRIVATE(ASN) \
    (((ASN) >= BGP_PRIVATE_AS_MIN && (ASN) <= BGP_PRIVATE_AS_MAX) || \
     ((ASN) >= BGP_PRIVATE_AS4_MIN && (ASN) <= BGP_PRIVATE_AS4_MAX))

/* AS_PATH segment data in abstracted form, no limit is placed on length */
struct assegment
{
  struct assegment *next;
  as_t *as;
  u_short length;
  u_char type;
};

/* AS path may be include some AsSegments.  */
struct aspath 
{
  /* Reference count to this aspath.  */
  unsigned long refcnt;

  /* segment data */
  struct assegment *segments;
  
  /* String expression of AS path.  This string is used by vty output
     and AS path regular expression match.  */
  char *str;
  unsigned short str_len;
};

#define ASPATH_STR_DEFAULT_LEN 32

/* Prototypes. */
extern void aspath_init (void);
extern void aspath_finish (void);
extern struct aspath *aspath_parse (struct stream *, size_t, int);
extern struct aspath *aspath_dup (struct aspath *);
extern struct aspath *aspath_aggregate (struct aspath *, struct aspath *);
extern struct aspath *aspath_aggregate_mpath (struct aspath *, struct aspath *);
extern struct aspath *aspath_prepend (struct aspath *, struct aspath *);
extern struct aspath *aspath_filter_exclude (struct aspath *, struct aspath *);
extern struct aspath *aspath_add_seq_n (struct aspath *, as_t, unsigned);
extern struct aspath *aspath_add_seq (struct aspath *, as_t);
extern struct aspath *aspath_add_confed_seq (struct aspath *, as_t);
extern int aspath_cmp (const void *, const void *);
extern int aspath_cmp_left (const struct aspath *, const struct aspath *);
extern int aspath_cmp_left_confed (const struct aspath *, const struct aspath *);
extern struct aspath *aspath_delete_confed_seq (struct aspath *);
extern struct aspath *aspath_empty (void);
extern struct aspath *aspath_empty_get (void);
extern struct aspath *aspath_str2aspath (const char *);
extern void aspath_free (struct aspath *);
extern struct aspath *aspath_intern (struct aspath *);
extern void aspath_unintern (struct aspath **);
extern const char *aspath_print (struct aspath *);
extern void aspath_print_vty (struct vty *, const char *, struct aspath *, const char *);
extern void aspath_print_all_vty (struct vty *);
extern unsigned int aspath_key_make (void *);
extern int aspath_loop_check (struct aspath *, as_t);
extern int aspath_private_as_check (struct aspath *);
extern int aspath_firstas_check (struct aspath *, as_t);
extern int aspath_confed_check (struct aspath *);
extern int aspath_left_confed_check (struct aspath *);
extern unsigned long aspath_count (void);
extern unsigned int aspath_count_hops (const struct aspath *);
extern unsigned int aspath_count_confeds (struct aspath *);
extern unsigned int aspath_size (struct aspath *);
extern as_t aspath_highest (struct aspath *);
extern as_t aspath_leftmost (struct aspath *);
extern size_t aspath_put (struct stream *, struct aspath *, int);

extern struct aspath *aspath_reconcile_as4 (struct aspath *, struct aspath *);
extern unsigned int aspath_has_as4 (struct aspath *);

/* For SNMP BGP4PATHATTRASPATHSEGMENT, might be useful for debug */
extern u_char *aspath_snmp_pathseg (struct aspath *, size_t *);

#endif /* _QUAGGA_BGP_ASPATH_H */