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 along
  18  * with this program; see the file COPYING; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef _QUAGGA_BGP_MPATH_H
  23 #define _QUAGGA_BGP_MPATH_H
  24
  25 /* Supplemental information linked to bgp_path_info for keeping track of
  26  * multipath selections, lazily allocated to save memory
  27  */
  28 struct bgp_path_info_mpath {
  29         /* Points to the first multipath (on bestpath) or the next multipath */
  30         struct bgp_path_info_mpath *mp_next;
  31
  32         /* Points to the previous multipath or NULL on bestpath */
  33         struct bgp_path_info_mpath *mp_prev;
  34
  35         /* Points to bgp_path_info associated with this multipath info */
  36         struct bgp_path_info *mp_info;
  37
  38         /* When attached to best path, the number of selected multipaths */
  39         uint32_t mp_count;
  40
  41         /* Aggregated attribute for advertising multipath route */
  42         struct attr *mp_attr;
  43 };
  44
  45 /* Functions to support maximum-paths configuration */
  46 extern int bgp_maximum_paths_set(struct bgp *, afi_t, safi_t, int, uint16_t,
  47                                  uint16_t);
  48 extern int bgp_maximum_paths_unset(struct bgp *, afi_t, safi_t, int);
  49
  50 /* Functions used by bgp_best_selection to record current
  51  * multipath selections
  52  */
  53 extern int bgp_path_info_nexthop_cmp(struct bgp_path_info *bpi1,
  54                                      struct bgp_path_info *bpi2);
  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 *mp_list, struct bgp_path_info *mpinfo);
  58 extern void bgp_mp_dmed_deselect(struct bgp_path_info *dmed_best);
  59 extern void bgp_path_info_mpath_update(struct bgp_node *rn,
  60                                        struct bgp_path_info *new_best,
  61                                        struct bgp_path_info *old_best,
  62                                        struct list *mp_list,
  63                                        struct bgp_maxpaths_cfg *mpath_cfg);
  64 extern void
  65 bgp_path_info_mpath_aggregate_update(struct bgp_path_info *new_best,
  66                                      struct bgp_path_info *old_best);
  67
  68 /* Unlink and free multipath information associated with a bgp_path_info */
  69 extern void bgp_path_info_mpath_dequeue(struct bgp_path_info *path);
  70 extern void bgp_path_info_mpath_free(struct bgp_path_info_mpath **mpath);
  71
  72 /* Walk list of multipaths associated with a best path */
  73 extern struct bgp_path_info *
  74 bgp_path_info_mpath_first(struct bgp_path_info *path);
  75 extern struct bgp_path_info *
  76 bgp_path_info_mpath_next(struct bgp_path_info *path);
  77
  78 /* Accessors for multipath information */
  79 extern uint32_t bgp_path_info_mpath_count(struct bgp_path_info *path);
  80 extern struct attr *bgp_path_info_mpath_attr(struct bgp_path_info *path);
  81
  82 #endif /* _QUAGGA_BGP_MPATH_H */