eigrpd/eigrp_topology.c

   1 /*
   2  * EIGRP Topology Table.
   3  * Copyright (C) 2013-2016
   4  * Authors:
   5  *   Donnie Savage
   6  *   Jan Janovic
   7  *   Matej Perina
   8  *   Peter Orsag
   9  *   Peter Paluch
  10  *   Frantisek Gazo
  11  *   Tomas Hvorkovy
  12  *   Martin Kontsek
  13  *   Lukas Koribsky
  14  *
  15  * This file is part of GNU Zebra.
  16  *
  17  * GNU Zebra is free software; you can redistribute it and/or modify it
  18  * under the terms of the GNU General Public License as published by the
  19  * Free Software Foundation; either version 2, or (at your option) any
  20  * later version.
  21  *
  22  * GNU Zebra is distributed in the hope that it will be useful, but
  23  * WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  * General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License along
  28  * with this program; see the file COPYING; if not, write to the Free Software
  29  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  30  */
  31
  32 #include <zebra.h>
  33
  34 #include "prefix.h"
  35 #include "table.h"
  36 #include "memory.h"
  37 #include "log.h"
  38 #include "linklist.h"
  39 #include "vty.h"
  40 #include "lib_errors.h"
  41
  42 #include "eigrpd/eigrp_structs.h"
  43 #include "eigrpd/eigrpd.h"
  44 #include "eigrpd/eigrp_interface.h"
  45 #include "eigrpd/eigrp_neighbor.h"
  46 #include "eigrpd/eigrp_packet.h"
  47 #include "eigrpd/eigrp_zebra.h"
  48 #include "eigrpd/eigrp_vty.h"
  49 #include "eigrpd/eigrp_network.h"
  50 #include "eigrpd/eigrp_dump.h"
  51 #include "eigrpd/eigrp_topology.h"
  52 #include "eigrpd/eigrp_fsm.h"
  53 #include "eigrpd/eigrp_memory.h"
  54
  55 static int eigrp_nexthop_entry_cmp(struct eigrp_nexthop_entry *,
  56                                    struct eigrp_nexthop_entry *);
  57
  58 /*
  59  * Returns linkedlist used as topology table
  60  * cmp - assigned function for comparing topology nodes
  61  * del - assigned function executed before deleting topology node by list
  62  * function
  63  */
  64 struct route_table *eigrp_topology_new()
  65 {
  66         return route_table_init();
  67 }
  68
  69 /*
  70  * Returns new created toplogy node
  71  * cmp - assigned function for comparing topology entry
  72  */
  73 struct eigrp_prefix_entry *eigrp_prefix_entry_new()
  74 {
  75         struct eigrp_prefix_entry *new;
  76         new = XCALLOC(MTYPE_EIGRP_PREFIX_ENTRY,
  77                       sizeof(struct eigrp_prefix_entry));
  78         new->entries = list_new();
  79         new->rij = list_new();
  80         new->entries->cmp = (int (*)(void *, void *))eigrp_nexthop_entry_cmp;
  81         new->distance = new->fdistance = new->rdistance = EIGRP_MAX_METRIC;
  82         new->destination = NULL;
  83
  84         return new;
  85 }
  86
  87 /*
  88  * Topology entry comparison
  89  */
  90 static int eigrp_nexthop_entry_cmp(struct eigrp_nexthop_entry *entry1,
  91                                    struct eigrp_nexthop_entry *entry2)
  92 {
  93         if (entry1->distance < entry2->distance)
  94                 return -1;
  95         if (entry1->distance > entry2->distance)
  96                 return 1;
  97
  98         return 0;
  99 }
 100
 101 /*
 102  * Returns new topology entry
 103  */
 104
 105 struct eigrp_nexthop_entry *eigrp_nexthop_entry_new()
 106 {
 107         struct eigrp_nexthop_entry *new;
 108
 109         new = XCALLOC(MTYPE_EIGRP_NEXTHOP_ENTRY,
 110                       sizeof(struct eigrp_nexthop_entry));
 111         new->reported_distance = EIGRP_MAX_METRIC;
 112         new->distance = EIGRP_MAX_METRIC;
 113
 114         return new;
 115 }
 116
 117 /*
 118  * Freeing topology table list
 119  */
 120 void eigrp_topology_free(struct route_table *table)
 121 {
 122         eigrp_topology_delete_all(table);
 123         route_table_finish(table);
 124 }
 125
 126 /*
 127  * Adding topology node to topology table
 128  */
 129 void eigrp_prefix_entry_add(struct route_table *topology,
 130                             struct eigrp_prefix_entry *pe)
 131 {
 132         struct route_node *rn;
 133
 134         rn = route_node_get(topology, pe->destination);
 135         if (rn->info) {
 136                 if (IS_DEBUG_EIGRP_EVENT) {
 137                         char buf[PREFIX_STRLEN];
 138
 139                         zlog_debug(
 140                                 "%s: %s Should we have found this entry in the topo table?",
 141                                 __PRETTY_FUNCTION__,
 142                                 prefix2str(pe->destination, buf, sizeof(buf)));
 143                 }
 144         }
 145
 146         rn->info = pe;
 147         route_lock_node(rn);
 148 }
 149
 150 /*
 151  * Adding topology entry to topology node
 152  */
 153 void eigrp_nexthop_entry_add(struct eigrp_prefix_entry *node,
 154                              struct eigrp_nexthop_entry *entry)
 155 {
 156         struct list *l = list_new();
 157
 158         listnode_add(l, entry);
 159
 160         if (listnode_lookup(node->entries, entry) == NULL) {
 161                 listnode_add_sort(node->entries, entry);
 162                 entry->prefix = node;
 163
 164                 eigrp_zebra_route_add(node->destination, l);
 165         }
 166
 167         list_delete(&l);
 168 }
 169
 170 /*
 171  * Deleting topology node from topology table
 172  */
 173 void eigrp_prefix_entry_delete(struct route_table *table,
 174                                struct eigrp_prefix_entry *pe)
 175 {
 176         struct eigrp *eigrp = eigrp_lookup();
 177         struct eigrp_nexthop_entry *ne;
 178         struct listnode *node, *nnode;
 179         struct route_node *rn;
 180
 181         if (!eigrp)
 182                 return;
 183
 184         rn = route_node_lookup(table, pe->destination);
 185         if (!rn)
 186                 return;
 187
 188         /*
 189          * Emergency removal of the node from this list.
 190          * Whatever it is.
 191          */
 192         listnode_delete(eigrp->topology_changes_internalIPV4, pe);
 193
 194         for (ALL_LIST_ELEMENTS(pe->entries, node, nnode, ne))
 195                 eigrp_nexthop_entry_delete(pe, ne);
 196         list_delete(&pe->entries);
 197         list_delete(&pe->rij);
 198         eigrp_zebra_route_delete(pe->destination);
 199         prefix_free(pe->destination);
 200
 201         rn->info = NULL;
 202         route_unlock_node(rn); // Lookup above
 203         route_unlock_node(rn); // Initial creation
 204         XFREE(MTYPE_EIGRP_PREFIX_ENTRY, pe);
 205 }
 206
 207 /*
 208  * Deleting topology entry from topology node
 209  */
 210 void eigrp_nexthop_entry_delete(struct eigrp_prefix_entry *node,
 211                                 struct eigrp_nexthop_entry *entry)
 212 {
 213         if (listnode_lookup(node->entries, entry) != NULL) {
 214                 listnode_delete(node->entries, entry);
 215                 eigrp_zebra_route_delete(node->destination);
 216                 XFREE(MTYPE_EIGRP_NEXTHOP_ENTRY, entry);
 217         }
 218 }
 219
 220 /*
 221  * Deleting all nodes from topology table
 222  */
 223 void eigrp_topology_delete_all(struct route_table *topology)
 224 {
 225         struct route_node *rn;
 226         struct eigrp_prefix_entry *pe;
 227
 228         for (rn = route_top(topology); rn; rn = route_next(rn)) {
 229                 pe = rn->info;
 230
 231                 if (!pe)
 232                         continue;
 233
 234                 eigrp_prefix_entry_delete(topology, pe);
 235         }
 236 }
 237
 238 struct eigrp_prefix_entry *
 239 eigrp_topology_table_lookup_ipv4(struct route_table *table,
 240                                  struct prefix *address)
 241 {
 242         struct eigrp_prefix_entry *pe;
 243         struct route_node *rn;
 244
 245         rn = route_node_lookup(table, address);
 246         if (!rn)
 247                 return NULL;
 248
 249         pe = rn->info;
 250
 251         route_unlock_node(rn);
 252
 253         return pe;
 254 }
 255
 256 /*
 257  * For a future optimization, put the successor list into it's
 258  * own separate list from the full list?
 259  *
 260  * That way we can clean up all the list_new and list_delete's
 261  * that we are doing.  DBS
 262  */
 263 struct list *eigrp_topology_get_successor(struct eigrp_prefix_entry *table_node)
 264 {
 265         struct list *successors = list_new();
 266         struct eigrp_nexthop_entry *data;
 267         struct listnode *node1, *node2;
 268
 269         for (ALL_LIST_ELEMENTS(table_node->entries, node1, node2, data)) {
 270                 if (data->flags & EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG) {
 271                         listnode_add(successors, data);
 272                 }
 273         }
 274
 275         /*
 276          * If we have no successors return NULL
 277          */
 278         if (!successors->count) {
 279                 list_delete(&successors);
 280                 successors = NULL;
 281         }
 282
 283         return successors;
 284 }
 285
 286 struct list *
 287 eigrp_topology_get_successor_max(struct eigrp_prefix_entry *table_node,
 288                                  unsigned int maxpaths)
 289 {
 290         struct list *successors = eigrp_topology_get_successor(table_node);
 291
 292         if (successors && successors->count > maxpaths) {
 293                 do {
 294                         struct listnode *node = listtail(successors);
 295
 296                         list_delete_node(successors, node);
 297
 298                 } while (successors->count > maxpaths);
 299         }
 300
 301         return successors;
 302 }
 303
 304 struct eigrp_nexthop_entry *
 305 eigrp_prefix_entry_lookup(struct list *entries, struct eigrp_neighbor *nbr)
 306 {
 307         struct eigrp_nexthop_entry *data;
 308         struct listnode *node, *nnode;
 309         for (ALL_LIST_ELEMENTS(entries, node, nnode, data)) {
 310                 if (data->adv_router == nbr) {
 311                         return data;
 312                 }
 313         }
 314
 315         return NULL;
 316 }
 317
 318 /* Lookup all prefixes from specified neighbor */
 319 struct list *eigrp_neighbor_prefixes_lookup(struct eigrp *eigrp,
 320                                             struct eigrp_neighbor *nbr)
 321 {
 322         struct listnode *node2, *node22;
 323         struct eigrp_nexthop_entry *entry;
 324         struct eigrp_prefix_entry *pe;
 325         struct route_node *rn;
 326
 327         /* create new empty list for prefixes storage */
 328         struct list *prefixes = list_new();
 329
 330         /* iterate over all prefixes in topology table */
 331         for (rn = route_top(eigrp->topology_table); rn; rn = route_next(rn)) {
 332                 if (!rn->info)
 333                         continue;
 334                 pe = rn->info;
 335                 /* iterate over all neighbor entry in prefix */
 336                 for (ALL_LIST_ELEMENTS(pe->entries, node2, node22, entry)) {
 337                         /* if entry is from specified neighbor, add to list */
 338                         if (entry->adv_router == nbr) {
 339                                 listnode_add(prefixes, pe);
 340                         }
 341                 }
 342         }
 343
 344         /* return list of prefixes from specified neighbor */
 345         return prefixes;
 346 }
 347
 348 enum metric_change
 349 eigrp_topology_update_distance(struct eigrp_fsm_action_message *msg)
 350 {
 351         struct eigrp *eigrp = msg->eigrp;
 352         struct eigrp_prefix_entry *prefix = msg->prefix;
 353         struct eigrp_nexthop_entry *entry = msg->entry;
 354         enum metric_change change = METRIC_SAME;
 355         uint32_t new_reported_distance;
 356
 357         assert(entry);
 358
 359         switch (msg->data_type) {
 360         case EIGRP_CONNECTED:
 361                 if (prefix->nt == EIGRP_TOPOLOGY_TYPE_CONNECTED)
 362                         return change;
 363
 364                 change = METRIC_DECREASE;
 365                 break;
 366         case EIGRP_INT:
 367                 if (prefix->nt == EIGRP_TOPOLOGY_TYPE_CONNECTED) {
 368                         change = METRIC_INCREASE;
 369                         goto distance_done;
 370                 }
 371                 if (eigrp_metrics_is_same(msg->metrics,
 372                                           entry->reported_metric)) {
 373                         return change; // No change
 374                 }
 375
 376                 new_reported_distance =
 377                         eigrp_calculate_metrics(eigrp, msg->metrics);
 378
 379                 if (entry->reported_distance < new_reported_distance) {
 380                         change = METRIC_INCREASE;
 381                         goto distance_done;
 382                 } else
 383                         change = METRIC_DECREASE;
 384
 385                 entry->reported_metric = msg->metrics;
 386                 entry->reported_distance = new_reported_distance;
 387                 eigrp_calculate_metrics(eigrp, msg->metrics);
 388                 entry->distance = eigrp_calculate_total_metrics(eigrp, entry);
 389                 break;
 390         case EIGRP_EXT:
 391                 if (prefix->nt == EIGRP_TOPOLOGY_TYPE_REMOTE_EXTERNAL) {
 392                         if (eigrp_metrics_is_same(msg->metrics,
 393                                                   entry->reported_metric))
 394                                 return change;
 395                 } else {
 396                         change = METRIC_INCREASE;
 397                         goto distance_done;
 398                 }
 399                 break;
 400         default:
 401                 flog_err(EC_LIB_DEVELOPMENT, "%s: Please implement handler",
 402                          __PRETTY_FUNCTION__);
 403                 break;
 404         }
 405 distance_done:
 406         /*
 407          * Move to correct position in list according to new distance
 408          */
 409         listnode_delete(prefix->entries, entry);
 410         listnode_add_sort(prefix->entries, entry);
 411
 412         return change;
 413 }
 414
 415 void eigrp_topology_update_all_node_flags(struct eigrp *eigrp)
 416 {
 417         struct eigrp_prefix_entry *pe;
 418         struct route_node *rn;
 419
 420         if (!eigrp)
 421                 return;
 422
 423         for (rn = route_top(eigrp->topology_table); rn; rn = route_next(rn)) {
 424                 pe = rn->info;
 425
 426                 if (!pe)
 427                         continue;
 428
 429                 eigrp_topology_update_node_flags(pe);
 430         }
 431 }
 432
 433 void eigrp_topology_update_node_flags(struct eigrp_prefix_entry *dest)
 434 {
 435         struct listnode *node;
 436         struct eigrp_nexthop_entry *entry;
 437         struct eigrp *eigrp = eigrp_lookup();
 438
 439         assert(eigrp);
 440
 441         for (ALL_LIST_ELEMENTS_RO(dest->entries, node, entry)) {
 442                 if (entry->reported_distance < dest->fdistance) {
 443                         // is feasible successor, can be successor
 444                         if (((uint64_t)entry->distance
 445                              <= (uint64_t)dest->distance
 446                                         * (uint64_t)eigrp->variance)
 447                             && entry->distance != EIGRP_MAX_METRIC) {
 448                                 // is successor
 449                                 entry->flags |=
 450                                         EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG;
 451                                 entry->flags &=
 452                                         ~EIGRP_NEXTHOP_ENTRY_FSUCCESSOR_FLAG;
 453                         } else {
 454                                 // is feasible successor only
 455                                 entry->flags |=
 456                                         EIGRP_NEXTHOP_ENTRY_FSUCCESSOR_FLAG;
 457                                 entry->flags &=
 458                                         ~EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG;
 459                         }
 460                 } else {
 461                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_FSUCCESSOR_FLAG;
 462                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG;
 463                 }
 464         }
 465 }
 466
 467 void eigrp_update_routing_table(struct eigrp_prefix_entry *prefix)
 468 {
 469         struct eigrp *eigrp = eigrp_lookup();
 470         struct list *successors;
 471         struct listnode *node;
 472         struct eigrp_nexthop_entry *entry;
 473
 474         if (!eigrp)
 475                 return;
 476
 477         successors = eigrp_topology_get_successor_max(prefix, eigrp->max_paths);
 478
 479         if (successors) {
 480                 eigrp_zebra_route_add(prefix->destination, successors);
 481                 for (ALL_LIST_ELEMENTS_RO(successors, node, entry))
 482                         entry->flags |= EIGRP_NEXTHOP_ENTRY_INTABLE_FLAG;
 483
 484                 list_delete(&successors);
 485         } else {
 486                 eigrp_zebra_route_delete(prefix->destination);
 487                 for (ALL_LIST_ELEMENTS_RO(prefix->entries, node, entry))
 488                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_INTABLE_FLAG;
 489         }
 490 }
 491
 492 void eigrp_topology_neighbor_down(struct eigrp *eigrp,
 493                                   struct eigrp_neighbor *nbr)
 494 {
 495         struct listnode *node2, *node22;
 496         struct eigrp_prefix_entry *pe;
 497         struct eigrp_nexthop_entry *entry;
 498         struct route_node *rn;
 499
 500         for (rn = route_top(eigrp->topology_table); rn; rn = route_next(rn)) {
 501                 pe = rn->info;
 502
 503                 if (!pe)
 504                         continue;
 505
 506                 for (ALL_LIST_ELEMENTS(pe->entries, node2, node22, entry)) {
 507                         struct eigrp_fsm_action_message msg;
 508
 509                         if (entry->adv_router != nbr)
 510                                 continue;
 511
 512                         msg.metrics.delay = EIGRP_MAX_METRIC;
 513                         msg.packet_type = EIGRP_OPC_UPDATE;
 514                         msg.eigrp = eigrp;
 515                         msg.data_type = EIGRP_INT;
 516                         msg.adv_router = nbr;
 517                         msg.entry = entry;
 518                         msg.prefix = pe;
 519                         eigrp_fsm_event(&msg);
 520                 }
 521         }
 522
 523         eigrp_query_send_all(eigrp);
 524         eigrp_update_send_all(eigrp, nbr->ei);
 525 }
 526
 527 void eigrp_update_topology_table_prefix(struct route_table *table,
 528                                         struct eigrp_prefix_entry *prefix)
 529 {
 530         struct listnode *node1, *node2;
 531
 532         struct eigrp_nexthop_entry *entry;
 533         for (ALL_LIST_ELEMENTS(prefix->entries, node1, node2, entry)) {
 534                 if (entry->distance == EIGRP_MAX_METRIC) {
 535                         eigrp_nexthop_entry_delete(prefix, entry);
 536                 }
 537         }
 538         if (prefix->distance == EIGRP_MAX_METRIC
 539             && prefix->nt != EIGRP_TOPOLOGY_TYPE_CONNECTED) {
 540                 eigrp_prefix_entry_delete(table, prefix);
 541         }
 542 }