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         uint16_t mp_count;
  40
  41         /* Flags - relevant as noted. */
  42         uint16_t mp_flags;
  43 #define BGP_MP_LB_PRESENT 0x1 /* Link-bandwidth present for >= 1 path */
  44 #define BGP_MP_LB_ALL 0x2 /* Link-bandwidth present for all multipaths */
  45
  46         /* Aggregated attribute for advertising multipath route */
  47         struct attr *mp_attr;
  48
  49         /* Cumulative bandiwdth of all multipaths - attached to best path. */
  50         uint64_t cum_bw;
  51 };
  52
  53 /* Functions to support maximum-paths configuration */
  54 extern int bgp_maximum_paths_set(struct bgp *, afi_t, safi_t, int, uint16_t,
  55                                  uint16_t);
  56 extern int bgp_maximum_paths_unset(struct bgp *, afi_t, safi_t, int);
  57
  58 /* Functions used by bgp_best_selection to record current
  59  * multipath selections
  60  */
  61 extern int bgp_path_info_nexthop_cmp(struct bgp_path_info *bpi1,
  62                                      struct bgp_path_info *bpi2);
  63 extern void bgp_mp_list_init(struct list *);
  64 extern void bgp_mp_list_clear(struct list *);
  65 extern void bgp_mp_list_add(struct list *mp_list, struct bgp_path_info *mpinfo);
  66 extern void bgp_mp_dmed_deselect(struct bgp_path_info *dmed_best);
  67 extern void bgp_path_info_mpath_update(struct bgp_node *rn,
  68                                        struct bgp_path_info *new_best,
  69                                        struct bgp_path_info *old_best,
  70                                        struct list *mp_list,
  71                                        struct bgp_maxpaths_cfg *mpath_cfg);
  72 extern void
  73 bgp_path_info_mpath_aggregate_update(struct bgp_path_info *new_best,
  74                                      struct bgp_path_info *old_best);
  75
  76 /* Unlink and free multipath information associated with a bgp_path_info */
  77 extern void bgp_path_info_mpath_dequeue(struct bgp_path_info *path);
  78 extern void bgp_path_info_mpath_free(struct bgp_path_info_mpath **mpath);
  79
  80 /* Walk list of multipaths associated with a best path */
  81 extern struct bgp_path_info *
  82 bgp_path_info_mpath_first(struct bgp_path_info *path);
  83 extern struct bgp_path_info *
  84 bgp_path_info_mpath_next(struct bgp_path_info *path);
  85
  86 /* Accessors for multipath information */
  87 extern uint32_t bgp_path_info_mpath_count(struct bgp_path_info *path);
  88 extern struct attr *bgp_path_info_mpath_attr(struct bgp_path_info *path);
  89 extern bool bgp_path_info_mpath_chkwtd(struct bgp *bgp,
  90                                        struct bgp_path_info *path);
  91 extern uint64_t bgp_path_info_mpath_cumbw(struct bgp_path_info *path);
  92
  93 #endif /* _QUAGGA_BGP_MPATH_H */