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
  41 #include "eigrpd/eigrp_structs.h"
  42 #include "eigrpd/eigrpd.h"
  43 #include "eigrpd/eigrp_interface.h"
  44 #include "eigrpd/eigrp_neighbor.h"
  45 #include "eigrpd/eigrp_packet.h"
  46 #include "eigrpd/eigrp_zebra.h"
  47 #include "eigrpd/eigrp_vty.h"
  48 #include "eigrpd/eigrp_network.h"
  49 #include "eigrpd/eigrp_dump.h"
  50 #include "eigrpd/eigrp_topology.h"
  51 #include "eigrpd/eigrp_fsm.h"
  52 #include "eigrpd/eigrp_memory.h"
  53
  54 static int eigrp_nexthop_entry_cmp(struct eigrp_nexthop_entry *,
  55                                    struct eigrp_nexthop_entry *);
  56
  57 /*
  58  * Returns linkedlist used as topology table
  59  * cmp - assigned function for comparing topology nodes
  60  * del - assigned function executed before deleting topology node by list
  61  * function
  62  */
  63 struct route_table *eigrp_topology_new()
  64 {
  65         return route_table_init();
  66 }
  67
  68 /*
  69  * Returns new created toplogy node
  70  * cmp - assigned function for comparing topology entry
  71  */
  72 struct eigrp_prefix_entry *eigrp_prefix_entry_new()
  73 {
  74         struct eigrp_prefix_entry *new;
  75         new = XCALLOC(MTYPE_EIGRP_PREFIX_ENTRY,
  76                       sizeof(struct eigrp_prefix_entry));
  77         new->entries = list_new();
  78         new->rij = list_new();
  79         new->entries->cmp = (int (*)(void *, void *))eigrp_nexthop_entry_cmp;
  80         new->distance = new->fdistance = new->rdistance = EIGRP_MAX_METRIC;
  81         new->destination = NULL;
  82
  83         return new;
  84 }
  85
  86 /*
  87  * Topology entry comparison
  88  */
  89 static int eigrp_nexthop_entry_cmp(struct eigrp_nexthop_entry *entry1,
  90                                    struct eigrp_nexthop_entry *entry2)
  91 {
  92         if (entry1->distance < entry2->distance)
  93                 return -1;
  94         if (entry1->distance > entry2->distance)
  95                 return 1;
  96
  97         return 0;
  98 }
  99
 100 /*
 101  * Returns new topology entry
 102  */
 103
 104 struct eigrp_nexthop_entry *eigrp_nexthop_entry_new()
 105 {
 106         struct eigrp_nexthop_entry *new;
 107
 108         new = XCALLOC(MTYPE_EIGRP_NEXTHOP_ENTRY,
 109                       sizeof(struct eigrp_nexthop_entry));
 110         new->reported_distance = EIGRP_MAX_METRIC;
 111         new->distance = EIGRP_MAX_METRIC;
 112
 113         return new;
 114 }
 115
 116 /*
 117  * Freeing topology table list
 118  */
 119 void eigrp_topology_free(struct route_table *table)
 120 {
 121         route_table_finish(table);
 122 }
 123
 124 /*
 125  * Deleting all topology nodes in table
 126  */
 127 void eigrp_topology_cleanup(struct route_table *table)
 128 {
 129         eigrp_topology_delete_all(table);
 130 }
 131
 132 /*
 133  * Adding topology node to topology table
 134  */
 135 void eigrp_prefix_entry_add(struct route_table *topology,
 136                             struct eigrp_prefix_entry *pe)
 137 {
 138         struct route_node *rn;
 139
 140         rn = route_node_get(topology, pe->destination);
 141         if (rn->info) {
 142                 if (IS_DEBUG_EIGRP_EVENT) {
 143                         char buf[PREFIX_STRLEN];
 144
 145                         zlog_debug(
 146                                 "%s: %s Should we have found this entry in the topo table?",
 147                                 __PRETTY_FUNCTION__,
 148                                 prefix2str(pe->destination, buf, sizeof(buf)));
 149                 }
 150         }
 151
 152         rn->info = pe;
 153         route_lock_node(rn);
 154 }
 155
 156 /*
 157  * Adding topology entry to topology node
 158  */
 159 void eigrp_nexthop_entry_add(struct eigrp_prefix_entry *node,
 160                              struct eigrp_nexthop_entry *entry)
 161 {
 162         struct list *l = list_new();
 163
 164         listnode_add(l, entry);
 165
 166         if (listnode_lookup(node->entries, entry) == NULL) {
 167                 listnode_add_sort(node->entries, entry);
 168                 entry->prefix = node;
 169
 170                 eigrp_zebra_route_add(node->destination, l);
 171         }
 172
 173         list_delete_and_null(&l);
 174 }
 175
 176 /*
 177  * Deleting topology node from topology table
 178  */
 179 void eigrp_prefix_entry_delete(struct route_table *table,
 180                                struct eigrp_prefix_entry *pe)
 181 {
 182         struct eigrp *eigrp = eigrp_lookup();
 183         struct route_node *rn;
 184
 185         rn = route_node_lookup(table, pe->destination);
 186         if (!rn)
 187                 return;
 188
 189         /*
 190          * Emergency removal of the node from this list.
 191          * Whatever it is.
 192          */
 193         listnode_delete(eigrp->topology_changes_internalIPV4, pe);
 194
 195         list_delete_and_null(&pe->entries);
 196         list_delete_and_null(&pe->rij);
 197         eigrp_zebra_route_delete(pe->destination);
 198
 199         rn->info = NULL;
 200         route_unlock_node(rn); // Lookup above
 201         route_unlock_node(rn); // Initial creation
 202         XFREE(MTYPE_EIGRP_PREFIX_ENTRY, pe);
 203 }
 204
 205 /*
 206  * Deleting topology entry from topology node
 207  */
 208 void eigrp_nexthop_entry_delete(struct eigrp_prefix_entry *node,
 209                                 struct eigrp_nexthop_entry *entry)
 210 {
 211         if (listnode_lookup(node->entries, entry) != NULL) {
 212                 listnode_delete(node->entries, entry);
 213                 eigrp_zebra_route_delete(node->destination);
 214                 XFREE(MTYPE_EIGRP_NEXTHOP_ENTRY, entry);
 215         }
 216 }
 217
 218 /*
 219  * Deleting all nodes from topology table
 220  */
 221 void eigrp_topology_delete_all(struct route_table *topology)
 222 {
 223         struct route_node *rn;
 224         struct eigrp_prefix_entry *pe;
 225
 226         for (rn = route_top(topology); rn; rn = route_next(rn)) {
 227                 pe = rn->info;
 228
 229                 if (!pe)
 230                         continue;
 231
 232                 eigrp_prefix_entry_delete(topology, pe);
 233         }
 234 }
 235
 236 /*
 237  * Return 0 if topology is not empty
 238  * otherwise return 1
 239  */
 240 unsigned int eigrp_topology_table_isempty(struct list *topology)
 241 {
 242         if (topology->count)
 243                 return 1;
 244         else
 245                 return 0;
 246 }
 247
 248 struct eigrp_prefix_entry *
 249 eigrp_topology_table_lookup_ipv4(struct route_table *table,
 250                                  struct prefix *address)
 251 {
 252         struct eigrp_prefix_entry *pe;
 253         struct route_node *rn;
 254
 255         rn = route_node_lookup(table, address);
 256         if (!rn)
 257                 return NULL;
 258
 259         pe = rn->info;
 260
 261         route_unlock_node(rn);
 262
 263         return pe;
 264 }
 265
 266 /*
 267  * For a future optimization, put the successor list into it's
 268  * own separate list from the full list?
 269  *
 270  * That way we can clean up all the list_new and list_delete's
 271  * that we are doing.  DBS
 272  */
 273 struct list *eigrp_topology_get_successor(struct eigrp_prefix_entry *table_node)
 274 {
 275         struct list *successors = list_new();
 276         struct eigrp_nexthop_entry *data;
 277         struct listnode *node1, *node2;
 278
 279         for (ALL_LIST_ELEMENTS(table_node->entries, node1, node2, data)) {
 280                 if (data->flags & EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG) {
 281                         listnode_add(successors, data);
 282                 }
 283         }
 284
 285         /*
 286          * If we have no successors return NULL
 287          */
 288         if (!successors->count) {
 289                 list_delete_and_null(&successors);
 290                 successors = NULL;
 291         }
 292
 293         return successors;
 294 }
 295
 296 struct list *
 297 eigrp_topology_get_successor_max(struct eigrp_prefix_entry *table_node,
 298                                  unsigned int maxpaths)
 299 {
 300         struct list *successors = eigrp_topology_get_successor(table_node);
 301
 302         if (successors && successors->count > maxpaths) {
 303                 do {
 304                         struct listnode *node = listtail(successors);
 305
 306                         list_delete_node(successors, node);
 307
 308                 } while (successors->count > maxpaths);
 309         }
 310
 311         return successors;
 312 }
 313
 314 struct eigrp_nexthop_entry *
 315 eigrp_prefix_entry_lookup(struct list *entries, struct eigrp_neighbor *nbr)
 316 {
 317         struct eigrp_nexthop_entry *data;
 318         struct listnode *node, *nnode;
 319         for (ALL_LIST_ELEMENTS(entries, node, nnode, data)) {
 320                 if (data->adv_router == nbr) {
 321                         return data;
 322                 }
 323         }
 324
 325         return NULL;
 326 }
 327
 328 /* Lookup all prefixes from specified neighbor */
 329 struct list *eigrp_neighbor_prefixes_lookup(struct eigrp *eigrp,
 330                                             struct eigrp_neighbor *nbr)
 331 {
 332         struct listnode *node2, *node22;
 333         struct eigrp_nexthop_entry *entry;
 334         struct eigrp_prefix_entry *pe;
 335         struct route_node *rn;
 336
 337         /* create new empty list for prefixes storage */
 338         struct list *prefixes = list_new();
 339
 340         /* iterate over all prefixes in topology table */
 341         for (rn = route_top(eigrp->topology_table); rn; rn = route_next(rn)) {
 342                 if (!rn->info)
 343                         continue;
 344                 pe = rn->info;
 345                 /* iterate over all neighbor entry in prefix */
 346                 for (ALL_LIST_ELEMENTS(pe->entries, node2, node22, entry)) {
 347                         /* if entry is from specified neighbor, add to list */
 348                         if (entry->adv_router == nbr) {
 349                                 listnode_add(prefixes, pe);
 350                         }
 351                 }
 352         }
 353
 354         /* return list of prefixes from specified neighbor */
 355         return prefixes;
 356 }
 357
 358 enum metric_change
 359 eigrp_topology_update_distance(struct eigrp_fsm_action_message *msg)
 360 {
 361         struct eigrp *eigrp = msg->eigrp;
 362         struct eigrp_prefix_entry *prefix = msg->prefix;
 363         struct eigrp_nexthop_entry *entry = msg->entry;
 364         enum metric_change change = METRIC_SAME;
 365         u_int32_t new_reported_distance;
 366
 367         assert(entry);
 368
 369         switch (msg->data_type) {
 370         case EIGRP_CONNECTED:
 371                 if (prefix->nt == EIGRP_TOPOLOGY_TYPE_CONNECTED)
 372                         return change;
 373
 374                 change = METRIC_DECREASE;
 375                 break;
 376         case EIGRP_INT:
 377                 if (prefix->nt == EIGRP_TOPOLOGY_TYPE_CONNECTED) {
 378                         change = METRIC_INCREASE;
 379                         goto distance_done;
 380                 }
 381                 if (eigrp_metrics_is_same(msg->metrics,
 382                                           entry->reported_metric)) {
 383                         return change; // No change
 384                 }
 385
 386                 new_reported_distance =
 387                         eigrp_calculate_metrics(eigrp, msg->metrics);
 388
 389                 if (entry->reported_distance < new_reported_distance) {
 390                         change = METRIC_INCREASE;
 391                         goto distance_done;
 392                 } else
 393                         change = METRIC_DECREASE;
 394
 395                 entry->reported_metric = msg->metrics;
 396                 entry->reported_distance = new_reported_distance;
 397                 eigrp_calculate_metrics(eigrp, msg->metrics);
 398                 entry->distance = eigrp_calculate_total_metrics(eigrp, entry);
 399                 break;
 400         case EIGRP_EXT:
 401                 if (prefix->nt == EIGRP_TOPOLOGY_TYPE_REMOTE_EXTERNAL) {
 402                         if (eigrp_metrics_is_same(msg->metrics,
 403                                                   entry->reported_metric))
 404                                 return change;
 405                 } else {
 406                         change = METRIC_INCREASE;
 407                         goto distance_done;
 408                 }
 409                 break;
 410         default:
 411                 zlog_err("%s: Please implement handler", __PRETTY_FUNCTION__);
 412                 break;
 413         }
 414 distance_done:
 415         /*
 416          * Move to correct position in list according to new distance
 417          */
 418         listnode_delete(prefix->entries, entry);
 419         listnode_add_sort(prefix->entries, entry);
 420
 421         return change;
 422 }
 423
 424 void eigrp_topology_update_all_node_flags(struct eigrp *eigrp)
 425 {
 426         struct eigrp_prefix_entry *pe;
 427         struct route_node *rn;
 428
 429         for (rn = route_top(eigrp->topology_table); rn; rn = route_next(rn)) {
 430                 pe = rn->info;
 431
 432                 if (!pe)
 433                         continue;
 434
 435                 eigrp_topology_update_node_flags(pe);
 436         }
 437 }
 438
 439 void eigrp_topology_update_node_flags(struct eigrp_prefix_entry *dest)
 440 {
 441         struct listnode *node;
 442         struct eigrp_nexthop_entry *entry;
 443         struct eigrp *eigrp = eigrp_lookup();
 444
 445         for (ALL_LIST_ELEMENTS_RO(dest->entries, node, entry)) {
 446                 if (((uint64_t)entry->distance
 447                      <= (uint64_t)dest->distance * (uint64_t)eigrp->variance)
 448                     && entry->distance != EIGRP_MAX_METRIC) // is successor
 449                 {
 450                         entry->flags |= EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG;
 451                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_FSUCCESSOR_FLAG;
 452                 } else if (entry->reported_distance
 453                            < dest->fdistance) // is feasible successor
 454                 {
 455                         entry->flags |= EIGRP_NEXTHOP_ENTRY_FSUCCESSOR_FLAG;
 456                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG;
 457                 } else {
 458                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_FSUCCESSOR_FLAG;
 459                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_SUCCESSOR_FLAG;
 460                 }
 461         }
 462 }
 463
 464 void eigrp_update_routing_table(struct eigrp_prefix_entry *prefix)
 465 {
 466         struct eigrp *eigrp = eigrp_lookup();
 467         struct list *successors =
 468                 eigrp_topology_get_successor_max(prefix, eigrp->max_paths);
 469         struct listnode *node;
 470         struct eigrp_nexthop_entry *entry;
 471
 472         if (successors) {
 473                 eigrp_zebra_route_add(prefix->destination, successors);
 474                 for (ALL_LIST_ELEMENTS_RO(successors, node, entry))
 475                         entry->flags |= EIGRP_NEXTHOP_ENTRY_INTABLE_FLAG;
 476
 477                 list_delete_and_null(&successors);
 478         } else {
 479                 eigrp_zebra_route_delete(prefix->destination);
 480                 for (ALL_LIST_ELEMENTS_RO(prefix->entries, node, entry))
 481                         entry->flags &= ~EIGRP_NEXTHOP_ENTRY_INTABLE_FLAG;
 482         }
 483 }
 484
 485 void eigrp_topology_neighbor_down(struct eigrp *eigrp,
 486                                   struct eigrp_neighbor *nbr)
 487 {
 488         struct listnode *node2, *node22;
 489         struct eigrp_prefix_entry *pe;
 490         struct eigrp_nexthop_entry *entry;
 491         struct route_node *rn;
 492
 493         for (rn = route_top(eigrp->topology_table); rn; rn = route_next(rn)) {
 494                 pe = rn->info;
 495
 496                 if (!pe)
 497                         continue;
 498
 499                 for (ALL_LIST_ELEMENTS(pe->entries, node2, node22, entry)) {
 500                         struct eigrp_fsm_action_message msg;
 501
 502                         if (entry->adv_router != nbr)
 503                                 continue;
 504
 505                         msg.metrics.delay = EIGRP_MAX_METRIC;
 506                         msg.packet_type = EIGRP_OPC_UPDATE;
 507                         msg.eigrp = eigrp;
 508                         msg.data_type = EIGRP_INT;
 509                         msg.adv_router = nbr;
 510                         msg.entry = entry;
 511                         msg.prefix = pe;
 512                         eigrp_fsm_event(&msg);
 513                 }
 514         }
 515
 516         eigrp_query_send_all(eigrp);
 517         eigrp_update_send_all(eigrp, nbr->ei);
 518 }
 519
 520 void eigrp_update_topology_table_prefix(struct route_table *table,
 521                                         struct eigrp_prefix_entry *prefix)
 522 {
 523         struct listnode *node1, *node2;
 524
 525         struct eigrp_nexthop_entry *entry;
 526         for (ALL_LIST_ELEMENTS(prefix->entries, node1, node2, entry)) {
 527                 if (entry->distance == EIGRP_MAX_METRIC) {
 528                         eigrp_nexthop_entry_delete(prefix, entry);
 529                 }
 530         }
 531         if (prefix->distance == EIGRP_MAX_METRIC
 532             && prefix->nt != EIGRP_TOPOLOGY_TYPE_CONNECTED) {
 533                 eigrp_prefix_entry_delete(table, prefix);
 534         }
 535 }