lib/nexthop_group.h

   1 /*
   2  * Nexthop Group structure definition.
   3  * Copyright (C) 2018 Cumulus Networks, Inc.
   4  *                    Donald Sharp
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef __NEXTHOP_GROUP__
  22 #define __NEXTHOP_GROUP__
  23
  24 #include <vty.h>
  25
  26 /*
  27  * What is a nexthop group?
  28  *
  29  * A nexthop group is a collection of nexthops that make up
  30  * the ECMP path for the route.
  31  *
  32  * This module provides a proper abstraction to this idea.
  33  */
  34 struct nexthop_group {
  35         struct nexthop *nexthop;
  36 };
  37
  38 struct nexthop_group *nexthop_group_new(void);
  39 void nexthop_group_delete(struct nexthop_group **nhg);
  40
  41 void nexthop_add(struct nexthop **target, struct nexthop *nexthop);
  42 void nexthop_del(struct nexthop_group *nhg, struct nexthop *nexthop);
  43 void copy_nexthops(struct nexthop **tnh, struct nexthop *nh,
  44                    struct nexthop *rparent);
  45
  46 /* The following for loop allows to iterate over the nexthop
  47  * structure of routes.
  48  *
  49  * head:      The pointer to the first nexthop in the chain.
  50  *
  51  * nexthop:   The pointer to the current nexthop, either in the
  52  *            top-level chain or in a resolved chain.
  53  */
  54 #define ALL_NEXTHOPS(head, nhop)                                        \
  55         (nhop) = (head.nexthop);                                        \
  56         (nhop);                                                         \
  57         (nhop) = nexthop_next(nhop)
  58
  59 struct nexthop_group_cmd {
  60
  61         RB_ENTRY(nexthop_group_cmd) nhgc_entry;
  62
  63         char name[80];
  64
  65         struct nexthop_group nhg;
  66
  67         QOBJ_FIELDS
  68 };
  69 RB_HEAD(nhgc_entry_head, nexthp_group_cmd);
  70 RB_PROTOTYPE(nhgc_entry_head, nexthop_group_cmd, nhgc_entry,
  71              nexthop_group_cmd_compare)
  72 DECLARE_QOBJ_TYPE(nexthop_group_cmd)
  73
  74 /*
  75  * Initialize nexthop_groups.  If you are interested in when
  76  * a nexthop_group is added/deleted/modified, then set the
  77  * appropriate callback functions to handle it in your
  78  * code
  79  */
  80 void nexthop_group_init(
  81         void (*new)(const char *name),
  82         void (*add_nexthop)(const struct nexthop_group_cmd *nhgc,
  83                             const struct nexthop *nhop),
  84         void (*del_nexthop)(const struct nexthop_group_cmd *nhgc,
  85                             const struct nexthop *nhop),
  86         void (*delete)(const char *name));
  87
  88 extern struct nexthop *nexthop_exists(struct nexthop_group *nhg,
  89                                       struct nexthop *nh);
  90
  91 extern struct nexthop_group_cmd *nhgc_find(const char *name);
  92
  93 extern void nexthop_group_write_nexthop(struct vty *vty, struct nexthop *nh);
  94 #endif