bgpd/bgp_mpath.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * BGP Multipath
   4  * Copyright (C) 2010 Google Inc.
   5  *
   6  * This file is part of Quagga
   7  */
   8
   9 #ifndef _FRR_BGP_MPATH_H
  10 #define _FRR_BGP_MPATH_H
  11
  12 /* Supplemental information linked to bgp_path_info for keeping track of
  13  * multipath selections, lazily allocated to save memory
  14  */
  15 struct bgp_path_info_mpath {
  16         /* Points to the first multipath (on bestpath) or the next multipath */
  17         struct bgp_path_info_mpath *mp_next;
  18
  19         /* Points to the previous multipath or NULL on bestpath */
  20         struct bgp_path_info_mpath *mp_prev;
  21
  22         /* Points to bgp_path_info associated with this multipath info */
  23         struct bgp_path_info *mp_info;
  24
  25         /* When attached to best path, the number of selected multipaths */
  26         uint16_t mp_count;
  27
  28         /* Flags - relevant as noted. */
  29         uint16_t mp_flags;
  30 #define BGP_MP_LB_PRESENT 0x1 /* Link-bandwidth present for >= 1 path */
  31 #define BGP_MP_LB_ALL 0x2 /* Link-bandwidth present for all multipaths */
  32
  33         /* Aggregated attribute for advertising multipath route */
  34         struct attr *mp_attr;
  35
  36         /* Cumulative bandiwdth of all multipaths - attached to best path. */
  37         uint64_t cum_bw;
  38 };
  39
  40 /* Functions to support maximum-paths configuration */
  41 extern int bgp_maximum_paths_set(struct bgp *bgp, afi_t afi, safi_t safi,
  42                                  int peertype, uint16_t maxpaths,
  43                                  bool clusterlen);
  44 extern int bgp_maximum_paths_unset(struct bgp *bgp, afi_t afi, safi_t safi,
  45                                    int peertype);
  46
  47 /* Functions used by bgp_best_selection to record current
  48  * multipath selections
  49  */
  50 extern int bgp_path_info_nexthop_cmp(struct bgp_path_info *bpi1,
  51                                      struct bgp_path_info *bpi2);
  52 extern void bgp_mp_list_init(struct list *mp_list);
  53 extern void bgp_mp_list_clear(struct list *mp_list);
  54 extern void bgp_mp_list_add(struct list *mp_list, struct bgp_path_info *mpinfo);
  55 extern void bgp_mp_dmed_deselect(struct bgp_path_info *dmed_best);
  56 extern void bgp_path_info_mpath_update(struct bgp *bgp, struct bgp_dest *dest,
  57                                        struct bgp_path_info *new_best,
  58                                        struct bgp_path_info *old_best,
  59                                        struct list *mp_list,
  60                                        struct bgp_maxpaths_cfg *mpath_cfg);
  61 extern void
  62 bgp_path_info_mpath_aggregate_update(struct bgp_path_info *new_best,
  63                                      struct bgp_path_info *old_best);
  64
  65 /* Unlink and free multipath information associated with a bgp_path_info */
  66 extern void bgp_path_info_mpath_dequeue(struct bgp_path_info *path);
  67 extern void bgp_path_info_mpath_free(struct bgp_path_info_mpath **mpath);
  68
  69 /* Walk list of multipaths associated with a best path */
  70 extern struct bgp_path_info *
  71 bgp_path_info_mpath_first(struct bgp_path_info *path);
  72 extern struct bgp_path_info *
  73 bgp_path_info_mpath_next(struct bgp_path_info *path);
  74
  75 /* Accessors for multipath information */
  76 extern uint32_t bgp_path_info_mpath_count(struct bgp_path_info *path);
  77 extern struct attr *bgp_path_info_mpath_attr(struct bgp_path_info *path);
  78 extern bool bgp_path_info_mpath_chkwtd(struct bgp *bgp,
  79                                        struct bgp_path_info *path);
  80 extern uint64_t bgp_path_info_mpath_cumbw(struct bgp_path_info *path);
  81
  82 #endif /* _FRR_BGP_MPATH_H */