1/* $QuaggaId: Format:%an, %ai, %h$ $
2 *
3 * BGP Multipath
4 * Copyright (C) 2010 Google Inc.
5 *
6 * This file is part of Quagga
7 *
8 * Quagga is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2, or (at your option) any
11 * later version.
12 *
13 * Quagga is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with Quagga; see the file COPYING.  If not, write to the Free
20 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
21 * 02111-1307, USA.
22 */
23
24#ifndef _QUAGGA_BGP_MPATH_H
25#define _QUAGGA_BGP_MPATH_H
26
27/* BGP default maximum-paths */
28#define BGP_DEFAULT_MAXPATHS 1
29
30/* Supplemental information linked to bgp_info for keeping track of
31 * multipath selections, lazily allocated to save memory
32 */
33struct bgp_info_mpath
34{
35  /* Points to the first multipath (on bestpath) or the next multipath */
36  struct bgp_info_mpath *mp_next;
37
38  /* Points to the previous multipath or NULL on bestpath */
39  struct bgp_info_mpath *mp_prev;
40
41  /* Points to bgp_info associated with this multipath info */
42  struct bgp_info *mp_info;
43
44  /* When attached to best path, the number of selected multipaths */
45  u_int32_t mp_count;
46
47  /* Aggregated attribute for advertising multipath route */
48  struct attr *mp_attr;
49};
50
51/* Functions to support maximum-paths configuration */
52extern int bgp_maximum_paths_set (struct bgp *, afi_t, safi_t, int, u_int16_t);
53extern int bgp_maximum_paths_unset (struct bgp *, afi_t, safi_t, int);
54
55/* Functions used by bgp_best_selection to record current
56 * multipath selections
57 */
58extern void bgp_mp_list_init (struct list *);
59extern void bgp_mp_list_clear (struct list *);
60extern void bgp_mp_list_add (struct list *, struct bgp_info *);
61extern void bgp_mp_dmed_deselect (struct bgp_info *);
62extern void bgp_info_mpath_update (struct bgp_node *, struct bgp_info *,
63                                   struct bgp_info *, struct list *,
64                                   struct bgp_maxpaths_cfg *);
65extern void bgp_info_mpath_aggregate_update (struct bgp_info *,
66                                             struct bgp_info *);
67
68/* Unlink and free multipath information associated with a bgp_info */
69extern void bgp_info_mpath_dequeue (struct bgp_info *);
70extern void bgp_info_mpath_free (struct bgp_info_mpath **);
71
72/* Walk list of multipaths associated with a best path */
73extern struct bgp_info *bgp_info_mpath_first (struct bgp_info *);
74extern struct bgp_info *bgp_info_mpath_next (struct bgp_info *);
75
76/* Accessors for multipath information */
77extern u_int32_t bgp_info_mpath_count (struct bgp_info *);
78extern struct attr *bgp_info_mpath_attr (struct bgp_info *);
79
80#endif /* _QUAGGA_BGP_MPATH_H */
81