bgpd/bgp_mpath.h

   1 /*
   2  * BGP Multipath
   3  * Copyright (C) 2010 Google Inc.
   4  *
   5  * This file is part of Quagga
   6  *
   7  * Quagga is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * Quagga is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with Quagga; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #ifndef _QUAGGA_BGP_MPATH_H
  24 #define _QUAGGA_BGP_MPATH_H
  25
  26 /* Supplemental information linked to bgp_info for keeping track of
  27  * multipath selections, lazily allocated to save memory
  28  */
  29 struct bgp_info_mpath {
  30         /* Points to the first multipath (on bestpath) or the next multipath */
  31         struct bgp_info_mpath *mp_next;
  32
  33         /* Points to the previous multipath or NULL on bestpath */
  34         struct bgp_info_mpath *mp_prev;
  35
  36         /* Points to bgp_info associated with this multipath info */
  37         struct bgp_info *mp_info;
  38
  39         /* When attached to best path, the number of selected multipaths */
  40         u_int32_t mp_count;
  41
  42         /* Aggregated attribute for advertising multipath route */
  43         struct attr *mp_attr;
  44 };
  45
  46 /* Functions to support maximum-paths configuration */
  47 extern int bgp_maximum_paths_set(struct bgp *, afi_t, safi_t, int, u_int16_t,
  48                                  u_int16_t);
  49 extern int bgp_maximum_paths_unset(struct bgp *, afi_t, safi_t, int);
  50
  51 /* Functions used by bgp_best_selection to record current
  52  * multipath selections
  53  */
  54 extern int bgp_info_nexthop_cmp(struct bgp_info *bi1, struct bgp_info *bi2);
  55 extern void bgp_mp_list_init(struct list *);
  56 extern void bgp_mp_list_clear(struct list *);
  57 extern void bgp_mp_list_add(struct list *, struct bgp_info *);
  58 extern void bgp_mp_dmed_deselect(struct bgp_info *);
  59 extern void bgp_info_mpath_update(struct bgp_node *, struct bgp_info *,
  60                                   struct bgp_info *, struct list *,
  61                                   struct bgp_maxpaths_cfg *);
  62 extern void bgp_info_mpath_aggregate_update(struct bgp_info *,
  63                                             struct bgp_info *);
  64
  65 /* Unlink and free multipath information associated with a bgp_info */
  66 extern void bgp_info_mpath_dequeue(struct bgp_info *);
  67 extern void bgp_info_mpath_free(struct bgp_info_mpath **);
  68
  69 /* Walk list of multipaths associated with a best path */
  70 extern struct bgp_info *bgp_info_mpath_first(struct bgp_info *);
  71 extern struct bgp_info *bgp_info_mpath_next(struct bgp_info *);
  72
  73 /* Accessors for multipath information */
  74 extern u_int32_t bgp_info_mpath_count(struct bgp_info *);
  75 extern struct attr *bgp_info_mpath_attr(struct bgp_info *);
  76
  77 #endif /* _QUAGGA_BGP_MPATH_H */