bgp_attr.h

大名鼎鼎的路由器源码。程序分ZEBRA、OSPFRIP等3个包。程序框架采用一个路由协议一个进程的方式

/* BGP attributes. 
   Copyright (C) 1996, 97, 98 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.  */

/* Simple bit mapping. */
#define BITMAP_NBBY 8

#define SET_BITMAP(MAP, NUM) \
        SET_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))

#define CHECK_BITMAP(MAP, NUM) \
        CHECK_FLAG (MAP[(NUM) / BITMAP_NBBY], 1 << ((NUM) % BITMAP_NBBY))

/* BGP Attribute type range. */
#define BGP_ATTR_TYPE_RANGE     256
#define BGP_ATTR_BITMAP_SIZE    (BGP_ATTR_TYPE_RANGE / BITMAP_NBBY)

/* BGP Attribute flags. */
#define BGP_ATTR_FLAG_OPTIONAL  0x80	/* Attribute is optional. */
#define BGP_ATTR_FLAG_TRANS     0x40	/* Attribute is transitive. */
#define BGP_ATTR_FLAG_PARTIAL   0x20	/* Attribute is partial. */
#define BGP_ATTR_FLAG_EXTLEN    0x10	/* Extended length flag. */

/* BGP attribute header must bigger than 2. */
#define BGP_ATTR_MIN_LEN        2       /* Attribute flag and type. */

/* BGP attribute structure. */
struct attr
{
  /* Reference count of this attribute. */
  unsigned long refcnt;

  /* Flag of attribute is set or not. */
  u_int32_t flag;

  /* Attributes. */
  u_char origin;
  struct in_addr nexthop;
  u_int32_t med;
  u_int32_t local_pref;
  as_t aggregator_as;
  struct in_addr aggregator_addr;
  u_int32_t weight;
  struct in_addr originator_id;
  struct cluster_list *cluster;

  u_char mp_nexthop_len;
#ifdef HAVE_IPV6
  struct in6_addr mp_nexthop_global;
  struct in6_addr mp_nexthop_local;
#endif /* HAVE_IPV6 */
  struct in_addr mp_nexthop_global_in;
  struct in_addr mp_nexthop_local_in;

  /* AS Path structure */
  struct aspath *aspath;

  /* Community structure */
  struct community *community;	

  /* Extended Communities attribute. */
  struct ecommunity *ecommunity;

  /* Unknown transitive attribute. */
  struct transit *transit;
};

/* Router Reflector related structure. */
struct cluster_list
{
  unsigned long refcnt;
  int length;
  struct in_addr *list;
};

/* Unknown transit attribute. */
struct transit
{
  unsigned long refcnt;
  int length;
  u_char *val;
};

#define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))

/* Prototypes. */
void bgp_attr_init ();
int bgp_attr_parse (struct peer *, struct attr *, bgp_size_t,
		    struct bgp_nlri *, struct bgp_nlri *);
int bgp_attr_check (struct peer *, struct attr *);
struct attr *bgp_attr_intern (struct attr *attr);
void bgp_attr_unintern (struct attr *);
void bgp_attr_flush (struct attr *);
struct attr *bgp_attr_default_set (struct attr *attr, u_char);
struct attr *bgp_attr_default_intern (u_char);
struct attr *bgp_attr_aggregate_intern (struct bgp *, u_char, struct aspath *, struct community *, int as_set);
bgp_size_t bgp_packet_attribute (struct bgp *bgp, struct peer *, struct stream *, struct attr *, struct prefix *, afi_t, safi_t, struct peer *, struct prefix_rd *, u_char *);
bgp_size_t bgp_packet_withdraw (struct peer *peer, struct stream *s, struct prefix *p, afi_t, safi_t, struct prefix_rd *, u_char *);
void bgp_dump_routes_attr (struct stream *, struct attr *);
unsigned int attrhash_key_make (struct attr *);
int attrhash_cmp (struct attr *, struct attr *);
void attr_show_all (struct vty *);

/* Cluster list prototypes. */
int cluster_loop_check (struct cluster_list *, struct in_addr);
void cluster_unintern (struct cluster_list *);

/* Transit attribute prototypes. */
void transit_unintern (struct transit *);