isisd/isis_route.c

   1 /*
   2  * IS-IS Rout(e)ing protocol               - isis_route.c
   3  * Copyright (C) 2001,2002   Sampo Saaristo
   4  *                           Tampere University of Technology
   5  *                           Institute of Communications Engineering
   6  *
   7  *                                         based on ../ospf6d/ospf6_route.[ch]
   8  *                                         by Yasuhiro Ohara
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public Licenseas published by the Free
  12  * Software Foundation; either version 2 of the License, or (at your option)
  13  * any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  18  * more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; see the file COPYING; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 #include <zebra.h>
  26
  27 #include "thread.h"
  28 #include "linklist.h"
  29 #include "vty.h"
  30 #include "log.h"
  31 #include "lib_errors.h"
  32 #include "memory.h"
  33 #include "prefix.h"
  34 #include "hash.h"
  35 #include "if.h"
  36 #include "table.h"
  37 #include "srcdest_table.h"
  38
  39 #include "isis_constants.h"
  40 #include "isis_common.h"
  41 #include "isis_flags.h"
  42 #include "isisd.h"
  43 #include "isis_misc.h"
  44 #include "isis_adjacency.h"
  45 #include "isis_circuit.h"
  46 #include "isis_pdu.h"
  47 #include "isis_lsp.h"
  48 #include "isis_spf.h"
  49 #include "isis_route.h"
  50 #include "isis_zebra.h"
  51
  52 DEFINE_HOOK(isis_route_update_hook,
  53             (struct isis_area * area, struct prefix *prefix,
  54              struct isis_route_info *route_info),
  55             (area, prefix, route_info))
  56
  57 static struct isis_nexthop *nexthoplookup(struct list *nexthops, int family,
  58                                           union g_addr *ip, ifindex_t ifindex);
  59 static void isis_route_update(struct isis_area *area, struct prefix *prefix,
  60                               struct prefix_ipv6 *src_p,
  61                               struct isis_route_info *route_info);
  62
  63 static struct isis_nexthop *isis_nexthop_create(int family, union g_addr *ip,
  64                                                 ifindex_t ifindex)
  65 {
  66         struct isis_nexthop *nexthop;
  67
  68         nexthop = XCALLOC(MTYPE_ISIS_NEXTHOP, sizeof(struct isis_nexthop));
  69
  70         nexthop->family = family;
  71         nexthop->ifindex = ifindex;
  72         nexthop->ip = *ip;
  73
  74         return nexthop;
  75 }
  76
  77 static void isis_nexthop_delete(struct isis_nexthop *nexthop)
  78 {
  79         XFREE(MTYPE_ISIS_NEXTHOP, nexthop);
  80 }
  81
  82 static struct isis_nexthop *nexthoplookup(struct list *nexthops, int family,
  83                                           union g_addr *ip, ifindex_t ifindex)
  84 {
  85         struct listnode *node;
  86         struct isis_nexthop *nh;
  87
  88         for (ALL_LIST_ELEMENTS_RO(nexthops, node, nh)) {
  89                 if (nh->family != family)
  90                         continue;
  91                 if (nh->ifindex != ifindex)
  92                         continue;
  93
  94                 switch (family) {
  95                 case AF_INET:
  96                         if (IPV4_ADDR_CMP(&nh->ip.ipv4, &ip->ipv4))
  97                                 continue;
  98                         break;
  99                 case AF_INET6:
 100                         if (IPV6_ADDR_CMP(&nh->ip.ipv6, &ip->ipv6))
 101                                 continue;
 102                         break;
 103                 default:
 104                         flog_err(EC_LIB_DEVELOPMENT,
 105                                  "%s: unknown address family [%d]", __func__,
 106                                  family);
 107                         exit(1);
 108                 }
 109
 110                 return nh;
 111         }
 112
 113         return NULL;
 114 }
 115
 116 static void adjinfo2nexthop(int family, struct list *nexthops,
 117                             struct isis_adjacency *adj)
 118 {
 119         struct isis_nexthop *nh;
 120         union g_addr ip = {};
 121
 122         switch (family) {
 123         case AF_INET:
 124                 for (unsigned int i = 0; i < adj->ipv4_address_count; i++) {
 125                         ip.ipv4 = adj->ipv4_addresses[i];
 126
 127                         if (!nexthoplookup(nexthops, AF_INET, &ip,
 128                                            adj->circuit->interface->ifindex)) {
 129                                 nh = isis_nexthop_create(
 130                                         AF_INET, &ip,
 131                                         adj->circuit->interface->ifindex);
 132                                 listnode_add(nexthops, nh);
 133                                 break;
 134                         }
 135                 }
 136                 break;
 137         case AF_INET6:
 138                 for (unsigned int i = 0; i < adj->ipv6_address_count; i++) {
 139                         ip.ipv6 = adj->ipv6_addresses[i];
 140
 141                         if (!nexthoplookup(nexthops, AF_INET6, &ip,
 142                                            adj->circuit->interface->ifindex)) {
 143                                 nh = isis_nexthop_create(
 144                                         AF_INET6, &ip,
 145                                         adj->circuit->interface->ifindex);
 146                                 listnode_add(nexthops, nh);
 147                                 break;
 148                         }
 149                 }
 150                 break;
 151         default:
 152                 flog_err(EC_LIB_DEVELOPMENT, "%s: unknown address family [%d]",
 153                          __func__, family);
 154                 exit(1);
 155         }
 156 }
 157
 158 static struct isis_route_info *isis_route_info_new(struct prefix *prefix,
 159                                                    struct prefix_ipv6 *src_p,
 160                                                    uint32_t cost,
 161                                                    uint32_t depth,
 162                                                    struct list *adjacencies)
 163 {
 164         struct isis_route_info *rinfo;
 165         struct isis_adjacency *adj;
 166         struct listnode *node;
 167
 168         rinfo = XCALLOC(MTYPE_ISIS_ROUTE_INFO, sizeof(struct isis_route_info));
 169
 170         rinfo->nexthops = list_new();
 171         for (ALL_LIST_ELEMENTS_RO(adjacencies, node, adj)) {
 172                 /* check for force resync this route */
 173                 if (CHECK_FLAG(adj->circuit->flags,
 174                                ISIS_CIRCUIT_FLAPPED_AFTER_SPF))
 175                         SET_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_RESYNC);
 176
 177                 /* update neighbor router address */
 178                 switch (prefix->family) {
 179                 case AF_INET:
 180                         if (depth == 2 && prefix->prefixlen == 32)
 181                                 adj->router_address = prefix->u.prefix4;
 182                         break;
 183                 case AF_INET6:
 184                         if (depth == 2 && prefix->prefixlen == 128
 185                             && (!src_p || !src_p->prefixlen)) {
 186                                 adj->router_address6 = prefix->u.prefix6;
 187                         }
 188                         break;
 189                 default:
 190                         flog_err(EC_LIB_DEVELOPMENT,
 191                                  "%s: unknown address family [%d]", __func__,
 192                                  prefix->family);
 193                         exit(1);
 194                 }
 195                 adjinfo2nexthop(prefix->family, rinfo->nexthops, adj);
 196         }
 197
 198         rinfo->cost = cost;
 199         rinfo->depth = depth;
 200
 201         return rinfo;
 202 }
 203
 204 static void isis_route_info_delete(struct isis_route_info *route_info)
 205 {
 206         if (route_info->nexthops) {
 207                 route_info->nexthops->del =
 208                         (void (*)(void *))isis_nexthop_delete;
 209                 list_delete(&route_info->nexthops);
 210         }
 211
 212         XFREE(MTYPE_ISIS_ROUTE_INFO, route_info);
 213 }
 214
 215 static int isis_route_info_same_attrib(struct isis_route_info *new,
 216                                        struct isis_route_info *old)
 217 {
 218         if (new->cost != old->cost)
 219                 return 0;
 220         if (new->depth != old->depth)
 221                 return 0;
 222
 223         return 1;
 224 }
 225
 226 static int isis_route_info_same(struct isis_route_info *new,
 227                                 struct isis_route_info *old, uint8_t family)
 228 {
 229         struct listnode *node;
 230         struct isis_nexthop *nexthop;
 231
 232         if (!CHECK_FLAG(old->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED))
 233                 return 0;
 234
 235         if (CHECK_FLAG(new->flag, ISIS_ROUTE_FLAG_ZEBRA_RESYNC))
 236                 return 0;
 237
 238         if (!isis_route_info_same_attrib(new, old))
 239                 return 0;
 240
 241         for (ALL_LIST_ELEMENTS_RO(new->nexthops, node, nexthop))
 242                 if (!nexthoplookup(old->nexthops, nexthop->family, &nexthop->ip,
 243                                    nexthop->ifindex))
 244                         return 0;
 245
 246         for (ALL_LIST_ELEMENTS_RO(old->nexthops, node, nexthop))
 247                 if (!nexthoplookup(new->nexthops, nexthop->family, &nexthop->ip,
 248                                    nexthop->ifindex))
 249                         return 0;
 250
 251         return 1;
 252 }
 253
 254 struct isis_route_info *isis_route_create(struct prefix *prefix,
 255                                           struct prefix_ipv6 *src_p,
 256                                           uint32_t cost,
 257                                           uint32_t depth,
 258                                           struct list *adjacencies,
 259                                           struct isis_area *area,
 260                                           struct route_table *table)
 261 {
 262         struct route_node *route_node;
 263         struct isis_route_info *rinfo_new, *rinfo_old, *route_info = NULL;
 264         char buff[PREFIX2STR_BUFFER];
 265         uint8_t family;
 266
 267         family = prefix->family;
 268         /* for debugs */
 269         prefix2str(prefix, buff, sizeof(buff));
 270
 271         if (!table)
 272                 return NULL;
 273
 274         rinfo_new = isis_route_info_new(prefix, src_p, cost,
 275                                         depth, adjacencies);
 276         route_node = srcdest_rnode_get(table, prefix, src_p);
 277
 278         rinfo_old = route_node->info;
 279         if (!rinfo_old) {
 280                 if (isis->debugs & DEBUG_RTE_EVENTS)
 281                         zlog_debug("ISIS-Rte (%s) route created: %s",
 282                                    area->area_tag, buff);
 283                 route_info = rinfo_new;
 284                 UNSET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
 285         } else {
 286                 route_unlock_node(route_node);
 287                 if (isis->debugs & DEBUG_RTE_EVENTS)
 288                         zlog_debug("ISIS-Rte (%s) route already exists: %s",
 289                                    area->area_tag, buff);
 290                 if (isis_route_info_same(rinfo_new, rinfo_old, family)) {
 291                         if (isis->debugs & DEBUG_RTE_EVENTS)
 292                                 zlog_debug("ISIS-Rte (%s) route unchanged: %s",
 293                                            area->area_tag, buff);
 294                         isis_route_info_delete(rinfo_new);
 295                         route_info = rinfo_old;
 296                 } else {
 297                         if (isis->debugs & DEBUG_RTE_EVENTS)
 298                                 zlog_debug("ISIS-Rte (%s) route changed: %s",
 299                                            area->area_tag, buff);
 300                         isis_route_info_delete(rinfo_old);
 301                         route_info = rinfo_new;
 302                         UNSET_FLAG(route_info->flag,
 303                                    ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
 304                 }
 305         }
 306
 307         SET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ACTIVE);
 308         route_node->info = route_info;
 309
 310         return route_info;
 311 }
 312
 313 static void isis_route_delete(struct isis_area *area, struct route_node *rode,
 314                               struct route_table *table)
 315 {
 316         struct isis_route_info *rinfo;
 317         char buff[SRCDEST2STR_BUFFER];
 318         struct prefix *prefix;
 319         struct prefix_ipv6 *src_p;
 320
 321         /* for log */
 322         srcdest_rnode2str(rode, buff, sizeof(buff));
 323
 324         srcdest_rnode_prefixes(rode, (const struct prefix **)&prefix,
 325                                (const struct prefix **)&src_p);
 326
 327         rinfo = rode->info;
 328         if (rinfo == NULL) {
 329                 if (isis->debugs & DEBUG_RTE_EVENTS)
 330                         zlog_debug(
 331                                 "ISIS-Rte: tried to delete non-existant route %s",
 332                                 buff);
 333                 return;
 334         }
 335
 336         if (CHECK_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED)) {
 337                 UNSET_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE);
 338                 if (isis->debugs & DEBUG_RTE_EVENTS)
 339                         zlog_debug("ISIS-Rte: route delete  %s", buff);
 340                 isis_route_update(area, prefix, src_p, rinfo);
 341         }
 342         isis_route_info_delete(rinfo);
 343         rode->info = NULL;
 344         route_unlock_node(rode);
 345 }
 346
 347 static void isis_route_update(struct isis_area *area, struct prefix *prefix,
 348                               struct prefix_ipv6 *src_p,
 349                               struct isis_route_info *route_info)
 350 {
 351         if (CHECK_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ACTIVE)) {
 352                 if (CHECK_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED))
 353                         return;
 354
 355                 isis_zebra_route_add_route(prefix, src_p, route_info);
 356                 hook_call(isis_route_update_hook, area, prefix, route_info);
 357
 358                 SET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
 359                 UNSET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_RESYNC);
 360         } else {
 361                 if (!CHECK_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED))
 362                         return;
 363
 364                 isis_zebra_route_del_route(prefix, src_p, route_info);
 365                 hook_call(isis_route_update_hook, area, prefix, route_info);
 366
 367                 UNSET_FLAG(route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNCED);
 368         }
 369 }
 370
 371 static void _isis_route_verify_table(struct isis_area *area,
 372                                      struct route_table *table,
 373                                      struct route_table **tables)
 374 {
 375         struct route_node *rnode, *drnode;
 376         struct isis_route_info *rinfo;
 377         char buff[SRCDEST2STR_BUFFER];
 378
 379         for (rnode = route_top(table); rnode;
 380              rnode = srcdest_route_next(rnode)) {
 381                 if (rnode->info == NULL)
 382                         continue;
 383                 rinfo = rnode->info;
 384
 385                 struct prefix *dst_p;
 386                 struct prefix_ipv6 *src_p;
 387
 388                 srcdest_rnode_prefixes(rnode,
 389                                        (const struct prefix **)&dst_p,
 390                                        (const struct prefix **)&src_p);
 391
 392                 if (isis->debugs & DEBUG_RTE_EVENTS) {
 393                         srcdest2str(dst_p, src_p, buff, sizeof(buff));
 394                         zlog_debug(
 395                                 "ISIS-Rte (%s): route validate: %s %s %s %s",
 396                                 area->area_tag,
 397                                 (CHECK_FLAG(rinfo->flag,
 398                                             ISIS_ROUTE_FLAG_ZEBRA_SYNCED)
 399                                          ? "synced"
 400                                          : "not-synced"),
 401                                 (CHECK_FLAG(rinfo->flag,
 402                                             ISIS_ROUTE_FLAG_ZEBRA_RESYNC)
 403                                          ? "resync"
 404                                          : "not-resync"),
 405                                 (CHECK_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE)
 406                                          ? "active"
 407                                          : "inactive"),
 408                                 buff);
 409                 }
 410
 411                 isis_route_update(area, dst_p, src_p, rinfo);
 412
 413                 if (CHECK_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE))
 414                         continue;
 415
 416                 /* Area is either L1 or L2 => we use level route tables
 417                  * directly for
 418                  * validating => no problems with deleting routes. */
 419                 if (!tables) {
 420                         isis_route_delete(area, rnode, table);
 421                         continue;
 422                 }
 423
 424                 /* If area is L1L2, we work with merge table and
 425                  * therefore must
 426                  * delete node from level tables as well before deleting
 427                  * route info. */
 428                 for (int level = ISIS_LEVEL1; level <= ISIS_LEVEL2; level++) {
 429                         drnode = srcdest_rnode_lookup(tables[level - 1],
 430                                                       dst_p, src_p);
 431                         if (!drnode)
 432                                 continue;
 433
 434                         route_unlock_node(drnode);
 435
 436                         if (drnode->info != rnode->info)
 437                                 continue;
 438
 439                         drnode->info = NULL;
 440                         route_unlock_node(drnode);
 441                 }
 442
 443                 isis_route_delete(area, rnode, table);
 444         }
 445 }
 446
 447 void isis_route_verify_table(struct isis_area *area, struct route_table *table)
 448 {
 449         _isis_route_verify_table(area, table, NULL);
 450 }
 451
 452 /* Function to validate route tables for L1L2 areas. In this case we can't use
 453  * level route tables directly, we have to merge them at first. L1 routes are
 454  * preferred over the L2 ones.
 455  *
 456  * Merge algorithm is trivial (at least for now). All L1 paths are copied into
 457  * merge table at first, then L2 paths are added if L1 path for same prefix
 458  * doesn't already exists there.
 459  *
 460  * FIXME: Is it right place to do it at all? Maybe we should push both levels
 461  * to the RIB with different zebra route types and let RIB handle this? */
 462 void isis_route_verify_merge(struct isis_area *area,
 463                              struct route_table *level1_table,
 464                              struct route_table *level2_table)
 465 {
 466         struct route_table *tables[] = { level1_table, level2_table };
 467         struct route_table *merge;
 468         struct route_node *rnode, *mrnode;
 469
 470         merge = srcdest_table_init();
 471
 472         for (int level = ISIS_LEVEL1; level <= ISIS_LEVEL2; level++) {
 473                 for (rnode = route_top(tables[level - 1]); rnode;
 474                      rnode = srcdest_route_next(rnode)) {
 475                         struct isis_route_info *rinfo = rnode->info;
 476                         if (!rinfo)
 477                                 continue;
 478
 479                         struct prefix *prefix;
 480                         struct prefix_ipv6 *src_p;
 481
 482                         srcdest_rnode_prefixes(rnode,
 483                                                (const struct prefix **)&prefix,
 484                                                (const struct prefix **)&src_p);
 485                         mrnode = srcdest_rnode_get(merge, prefix, src_p);
 486                         struct isis_route_info *mrinfo = mrnode->info;
 487                         if (mrinfo) {
 488                                 route_unlock_node(mrnode);
 489                                 if (CHECK_FLAG(mrinfo->flag,
 490                                                ISIS_ROUTE_FLAG_ACTIVE)) {
 491                                         /* Clear the ZEBRA_SYNCED flag on the
 492                                          * L2 route when L1 wins, otherwise L2
 493                                          * won't get reinstalled when L1
 494                                          * disappears.
 495                                          */
 496                                         UNSET_FLAG(
 497                                                 rinfo->flag,
 498                                                 ISIS_ROUTE_FLAG_ZEBRA_SYNCED
 499                                         );
 500                                         continue;
 501                                 } else if (CHECK_FLAG(rinfo->flag,
 502                                                       ISIS_ROUTE_FLAG_ACTIVE)) {
 503                                         /* Clear the ZEBRA_SYNCED flag on the L1
 504                                          * route when L2 wins, otherwise L1
 505                                          * won't get reinstalled when it
 506                                          * reappears.
 507                                          */
 508                                         UNSET_FLAG(
 509                                                 mrinfo->flag,
 510                                                 ISIS_ROUTE_FLAG_ZEBRA_SYNCED
 511                                         );
 512                                 } else if (
 513                                         CHECK_FLAG(
 514                                                 mrinfo->flag,
 515                                                 ISIS_ROUTE_FLAG_ZEBRA_SYNCED)) {
 516                                         continue;
 517                                 }
 518                         }
 519                         mrnode->info = rnode->info;
 520                 }
 521         }
 522
 523         _isis_route_verify_table(area, merge, tables);
 524         route_table_finish(merge);
 525 }
 526
 527 void isis_route_invalidate_table(struct isis_area *area,
 528                                  struct route_table *table)
 529 {
 530         struct route_node *rode;
 531         struct isis_route_info *rinfo;
 532         for (rode = route_top(table); rode; rode = srcdest_route_next(rode)) {
 533                 if (rode->info == NULL)
 534                         continue;
 535                 rinfo = rode->info;
 536
 537                 UNSET_FLAG(rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE);
 538         }
 539 }