bgpd/bgp_table.c

   1 /* BGP routing table
   2  * Copyright (C) 1998, 2001 Kunihiro Ishiguro
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra 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
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for 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 #include <zebra.h>
  22
  23 #include "prefix.h"
  24 #include "memory.h"
  25 #include "sockunion.h"
  26 #include "queue.h"
  27 #include "filter.h"
  28 #include "command.h"
  29
  30 #include "bgpd/bgpd.h"
  31 #include "bgpd/bgp_table.h"
  32 #include "bgp_addpath.h"
  33
  34 void bgp_table_lock(struct bgp_table *rt)
  35 {
  36         rt->lock++;
  37 }
  38
  39 void bgp_table_unlock(struct bgp_table *rt)
  40 {
  41         assert(rt->lock > 0);
  42         rt->lock--;
  43
  44         if (rt->lock != 0) {
  45                 return;
  46         }
  47
  48         route_table_finish(rt->route_table);
  49         rt->route_table = NULL;
  50
  51         XFREE(MTYPE_BGP_TABLE, rt);
  52 }
  53
  54 void bgp_table_finish(struct bgp_table **rt)
  55 {
  56         if (*rt != NULL) {
  57                 bgp_table_unlock(*rt);
  58                 *rt = NULL;
  59         }
  60 }
  61
  62 /*
  63  * bgp_node_create
  64  */
  65 static struct route_node *bgp_node_create(route_table_delegate_t *delegate,
  66                                           struct route_table *table)
  67 {
  68         struct bgp_node *node;
  69         node = XCALLOC(MTYPE_BGP_NODE, sizeof(struct bgp_node));
  70         return bgp_node_to_rnode(node);
  71 }
  72
  73 /*
  74  * bgp_node_destroy
  75  */
  76 static void bgp_node_destroy(route_table_delegate_t *delegate,
  77                              struct route_table *table, struct route_node *node)
  78 {
  79         struct bgp_node *bgp_node;
  80         struct bgp_table *rt;
  81         bgp_node = bgp_node_from_rnode(node);
  82         rt = table->info;
  83
  84         if (rt->bgp) {
  85                 bgp_addpath_free_node_data(&rt->bgp->tx_addpath,
  86                                          &bgp_node->tx_addpath,
  87                                          rt->afi, rt->safi);
  88         }
  89
  90         XFREE(MTYPE_BGP_NODE, bgp_node);
  91 }
  92
  93 /*
  94  * Function vector to customize the behavior of the route table
  95  * library for BGP route tables.
  96  */
  97 route_table_delegate_t bgp_table_delegate = {.create_node = bgp_node_create,
  98                                              .destroy_node = bgp_node_destroy};
  99
 100 /*
 101  * bgp_table_init
 102  */
 103 struct bgp_table *bgp_table_init(struct bgp *bgp, afi_t afi, safi_t safi)
 104 {
 105         struct bgp_table *rt;
 106
 107         rt = XCALLOC(MTYPE_BGP_TABLE, sizeof(struct bgp_table));
 108
 109         rt->route_table = route_table_init_with_delegate(&bgp_table_delegate);
 110
 111         /*
 112          * Set up back pointer to bgp_table.
 113          */
 114         route_table_set_info(rt->route_table, rt);
 115
 116         /*
 117          * pointer to bgp instance allows working back from bgp_path_info to bgp
 118          */
 119         rt->bgp = bgp;
 120
 121         bgp_table_lock(rt);
 122         rt->afi = afi;
 123         rt->safi = safi;
 124
 125         return rt;
 126 }
 127
 128 static struct bgp_node *
 129 bgp_route_next_until_maxlen(struct bgp_node *node, const struct bgp_node *limit,
 130                             const uint8_t maxlen)
 131 {
 132         if (node->l_left && node->p.prefixlen < maxlen
 133             && node->l_left->p.prefixlen <= maxlen) {
 134                 return bgp_node_from_rnode(node->l_left);
 135         }
 136         if (node->l_right && node->p.prefixlen < maxlen
 137             && node->l_right->p.prefixlen <= maxlen) {
 138                 return bgp_node_from_rnode(node->l_right);
 139         }
 140
 141         while (node->parent && node != limit) {
 142                 if (bgp_node_from_rnode(node->parent->l_left) == node
 143                     && node->parent->l_right) {
 144                         return bgp_node_from_rnode(node->parent->l_right);
 145                 }
 146                 node = bgp_node_from_rnode(node->parent);
 147         }
 148         return NULL;
 149 }
 150
 151 void bgp_table_range_lookup(const struct bgp_table *table, struct prefix *p,
 152                             uint8_t maxlen, struct list *matches)
 153 {
 154         struct bgp_node *node = bgp_node_from_rnode(table->route_table->top);
 155         struct bgp_node *matched = NULL;
 156
 157         while (node && node->p.prefixlen <= p->prefixlen
 158                && prefix_match(&node->p, p)) {
 159                 if (node->info && node->p.prefixlen == p->prefixlen) {
 160                         matched = node;
 161                         break;
 162                 }
 163                 node = bgp_node_from_rnode(node->link[prefix_bit(
 164                         &p->u.prefix, node->p.prefixlen)]);
 165         }
 166
 167         if (node == NULL)
 168                 return;
 169
 170         if ((matched == NULL && node->p.prefixlen > maxlen) || !node->parent)
 171                 return;
 172         else if (matched == NULL)
 173                 matched = node = bgp_node_from_rnode(node->parent);
 174
 175         if (matched->info) {
 176                 bgp_lock_node(matched);
 177                 listnode_add(matches, matched);
 178         }
 179
 180         while ((node = bgp_route_next_until_maxlen(node, matched, maxlen))) {
 181                 if (prefix_match(p, &node->p)) {
 182                         if (node->info) {
 183                                 bgp_lock_node(node);
 184                                 listnode_add(matches, node);
 185                         }
 186                 }
 187         }
 188 }