zebra/zebra_rnh.c

   1 /* Zebra next hop tracking code
   2  * Copyright (C) 2013 Cumulus Networks, Inc.
   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 "table.h"
  25 #include "memory.h"
  26 #include "command.h"
  27 #include "if.h"
  28 #include "log.h"
  29 #include "sockunion.h"
  30 #include "linklist.h"
  31 #include "thread.h"
  32 #include "workqueue.h"
  33 #include "prefix.h"
  34 #include "routemap.h"
  35 #include "stream.h"
  36 #include "nexthop.h"
  37 #include "vrf.h"
  38
  39 #include "zebra/zebra_router.h"
  40 #include "zebra/rib.h"
  41 #include "zebra/rt.h"
  42 #include "zebra/zserv.h"
  43 #include "zebra/zebra_ns.h"
  44 #include "zebra/zebra_vrf.h"
  45 #include "zebra/redistribute.h"
  46 #include "zebra/debug.h"
  47 #include "zebra/zebra_rnh.h"
  48 #include "zebra/zebra_routemap.h"
  49 #include "zebra/interface.h"
  50 #include "zebra/zebra_memory.h"
  51 #include "zebra/zebra_errors.h"
  52
  53 DEFINE_MTYPE_STATIC(ZEBRA, RNH, "Nexthop tracking object")
  54
  55 static void free_state(vrf_id_t vrf_id, struct route_entry *re,
  56                        struct route_node *rn);
  57 static void copy_state(struct rnh *rnh, struct route_entry *re,
  58                        struct route_node *rn);
  59 static int compare_state(struct route_entry *r1, struct route_entry *r2);
  60 static int send_client(struct rnh *rnh, struct zserv *client, rnh_type_t type,
  61                        vrf_id_t vrf_id);
  62 static void print_rnh(struct route_node *rn, struct vty *vty);
  63 static int zebra_client_cleanup_rnh(struct zserv *client);
  64
  65 int zebra_rnh_ip_default_route = 0;
  66 int zebra_rnh_ipv6_default_route = 0;
  67
  68 void zebra_rnh_init(void)
  69 {
  70         hook_register(zserv_client_close, zebra_client_cleanup_rnh);
  71 }
  72
  73 static inline struct route_table *get_rnh_table(vrf_id_t vrfid, afi_t afi,
  74                                                 rnh_type_t type)
  75 {
  76         struct zebra_vrf *zvrf;
  77         struct route_table *t = NULL;
  78
  79         zvrf = zebra_vrf_lookup_by_id(vrfid);
  80         if (zvrf)
  81                 switch (type) {
  82                 case RNH_NEXTHOP_TYPE:
  83                         t = zvrf->rnh_table[afi];
  84                         break;
  85                 case RNH_IMPORT_CHECK_TYPE:
  86                         t = zvrf->import_check_table[afi];
  87                         break;
  88                 }
  89
  90         return t;
  91 }
  92
  93 char *rnh_str(struct rnh *rnh, char *buf, int size)
  94 {
  95         prefix2str(&(rnh->node->p), buf, size);
  96         return buf;
  97 }
  98
  99 static void zebra_rnh_remove_from_routing_table(struct rnh *rnh)
 100 {
 101         struct zebra_vrf *zvrf = zebra_vrf_lookup_by_id(rnh->vrf_id);
 102         struct route_table *table = zvrf->table[rnh->afi][SAFI_UNICAST];
 103         struct route_node *rn;
 104         rib_dest_t *dest;
 105
 106         if (!table)
 107                 return;
 108
 109         rn = route_node_match(table, &rnh->resolved_route);
 110         if (!rn)
 111                 return;
 112
 113         if (IS_ZEBRA_DEBUG_NHT_DETAILED) {
 114                 char buf[PREFIX_STRLEN];
 115                 char buf1[PREFIX_STRLEN];
 116
 117                 zlog_debug("%s: %u:%s removed from tracking on %s",
 118                            __PRETTY_FUNCTION__, rnh->vrf_id,
 119                            prefix2str(&rnh->node->p, buf, sizeof(buf)),
 120                            srcdest_rnode2str(rn, buf1, sizeof(buf)));
 121         }
 122
 123         dest = rib_dest_from_rnode(rn);
 124         rnh_list_del(&dest->nht, rnh);
 125         route_unlock_node(rn);
 126 }
 127
 128 static void zebra_rnh_store_in_routing_table(struct rnh *rnh)
 129 {
 130         struct zebra_vrf *zvrf = zebra_vrf_lookup_by_id(rnh->vrf_id);
 131         struct route_table *table = zvrf->table[rnh->afi][SAFI_UNICAST];
 132         struct route_node *rn;
 133         rib_dest_t *dest;
 134
 135         rn = route_node_match(table, &rnh->resolved_route);
 136         if (!rn)
 137                 return;
 138
 139         if (IS_ZEBRA_DEBUG_NHT_DETAILED) {
 140                 char buf[PREFIX_STRLEN];
 141                 char buf1[PREFIX_STRLEN];
 142
 143                 zlog_debug("%s: %u:%s added for tracking on %s",
 144                            __PRETTY_FUNCTION__, rnh->vrf_id,
 145                            prefix2str(&rnh->node->p, buf, sizeof(buf)),
 146                            srcdest_rnode2str(rn, buf1, sizeof(buf)));
 147         }
 148
 149         dest = rib_dest_from_rnode(rn);
 150         rnh_list_add_tail(&dest->nht, rnh);
 151         route_unlock_node(rn);
 152 }
 153
 154 struct rnh *zebra_add_rnh(struct prefix *p, vrf_id_t vrfid, rnh_type_t type,
 155                           bool *exists)
 156 {
 157         struct route_table *table;
 158         struct route_node *rn;
 159         struct rnh *rnh = NULL;
 160         char buf[PREFIX2STR_BUFFER];
 161         afi_t afi = family2afi(p->family);
 162
 163         if (IS_ZEBRA_DEBUG_NHT) {
 164                 prefix2str(p, buf, sizeof(buf));
 165                 zlog_debug("%u: Add RNH %s type %s", vrfid, buf,
 166                            rnh_type2str(type));
 167         }
 168         table = get_rnh_table(vrfid, afi, type);
 169         if (!table) {
 170                 prefix2str(p, buf, sizeof(buf));
 171                 flog_warn(EC_ZEBRA_RNH_NO_TABLE,
 172                           "%u: Add RNH %s type %s - table not found", vrfid,
 173                           buf, rnh_type2str(type));
 174                 exists = false;
 175                 return NULL;
 176         }
 177
 178         /* Make it sure prefixlen is applied to the prefix. */
 179         apply_mask(p);
 180
 181         /* Lookup (or add) route node.*/
 182         rn = route_node_get(table, p);
 183
 184         if (!rn->info) {
 185                 rnh = XCALLOC(MTYPE_RNH, sizeof(struct rnh));
 186
 187                 /*
 188                  * The resolved route is already 0.0.0.0/0 or
 189                  * 0::0/0 due to the calloc right above, but
 190                  * we should set the family so that future
 191                  * comparisons can just be done
 192                  */
 193                 rnh->resolved_route.family = p->family;
 194                 rnh->client_list = list_new();
 195                 rnh->vrf_id = vrfid;
 196                 rnh->type = type;
 197                 rnh->seqno = 0;
 198                 rnh->afi = afi;
 199                 rnh->zebra_pseudowire_list = list_new();
 200                 route_lock_node(rn);
 201                 rn->info = rnh;
 202                 rnh->node = rn;
 203                 *exists = false;
 204
 205                 zebra_rnh_store_in_routing_table(rnh);
 206         } else
 207                 *exists = true;
 208
 209         route_unlock_node(rn);
 210         return (rn->info);
 211 }
 212
 213 struct rnh *zebra_lookup_rnh(struct prefix *p, vrf_id_t vrfid, rnh_type_t type)
 214 {
 215         struct route_table *table;
 216         struct route_node *rn;
 217
 218         table = get_rnh_table(vrfid, family2afi(PREFIX_FAMILY(p)), type);
 219         if (!table)
 220                 return NULL;
 221
 222         /* Make it sure prefixlen is applied to the prefix. */
 223         apply_mask(p);
 224
 225         /* Lookup route node.*/
 226         rn = route_node_lookup(table, p);
 227         if (!rn)
 228                 return NULL;
 229
 230         route_unlock_node(rn);
 231         return (rn->info);
 232 }
 233
 234 void zebra_free_rnh(struct rnh *rnh)
 235 {
 236         struct zebra_vrf *zvrf;
 237         struct route_table *table;
 238
 239         zebra_rnh_remove_from_routing_table(rnh);
 240         rnh->flags |= ZEBRA_NHT_DELETED;
 241         list_delete(&rnh->client_list);
 242         list_delete(&rnh->zebra_pseudowire_list);
 243
 244         zvrf = zebra_vrf_lookup_by_id(rnh->vrf_id);
 245         table = zvrf->table[family2afi(rnh->resolved_route.family)][SAFI_UNICAST];
 246
 247         if (table) {
 248                 struct route_node *rern;
 249
 250                 rern = route_node_match(table, &rnh->resolved_route);
 251                 if (rern) {
 252                         rib_dest_t *dest;
 253
 254                         route_unlock_node(rern);
 255
 256                         dest = rib_dest_from_rnode(rern);
 257                         rnh_list_del(&dest->nht, rnh);
 258                 }
 259         }
 260         free_state(rnh->vrf_id, rnh->state, rnh->node);
 261         XFREE(MTYPE_RNH, rnh);
 262 }
 263
 264 static void zebra_delete_rnh(struct rnh *rnh, rnh_type_t type)
 265 {
 266         struct route_node *rn;
 267
 268         if (!list_isempty(rnh->client_list)
 269             || !list_isempty(rnh->zebra_pseudowire_list))
 270                 return;
 271
 272         if ((rnh->flags & ZEBRA_NHT_DELETED) || !(rn = rnh->node))
 273                 return;
 274
 275         if (IS_ZEBRA_DEBUG_NHT) {
 276                 char buf[PREFIX2STR_BUFFER];
 277                 zlog_debug("%u: Del RNH %s type %s", rnh->vrf_id,
 278                            rnh_str(rnh, buf, sizeof(buf)), rnh_type2str(type));
 279         }
 280
 281         zebra_free_rnh(rnh);
 282         rn->info = NULL;
 283         route_unlock_node(rn);
 284 }
 285
 286 /*
 287  * This code will send to the registering client
 288  * the looked up rnh.
 289  * For a rnh that was created, there is no data
 290  * so it will send an empty nexthop group
 291  * If rnh exists then we know it has been evaluated
 292  * and as such it will have a resolved rnh.
 293  */
 294 void zebra_add_rnh_client(struct rnh *rnh, struct zserv *client,
 295                           rnh_type_t type, vrf_id_t vrf_id)
 296 {
 297         if (IS_ZEBRA_DEBUG_NHT) {
 298                 char buf[PREFIX2STR_BUFFER];
 299                 zlog_debug("%u: Client %s registers for RNH %s type %s", vrf_id,
 300                            zebra_route_string(client->proto),
 301                            rnh_str(rnh, buf, sizeof(buf)), rnh_type2str(type));
 302         }
 303         if (!listnode_lookup(rnh->client_list, client))
 304                 listnode_add(rnh->client_list, client);
 305
 306         /*
 307          * We always need to respond with known information,
 308          * currently multiple daemons expect this behavior
 309          */
 310         send_client(rnh, client, type, vrf_id);
 311 }
 312
 313 void zebra_remove_rnh_client(struct rnh *rnh, struct zserv *client,
 314                              rnh_type_t type)
 315 {
 316         if (IS_ZEBRA_DEBUG_NHT) {
 317                 char buf[PREFIX2STR_BUFFER];
 318                 zlog_debug("Client %s unregisters for RNH %s type %s",
 319                            zebra_route_string(client->proto),
 320                            rnh_str(rnh, buf, sizeof(buf)), rnh_type2str(type));
 321         }
 322         listnode_delete(rnh->client_list, client);
 323         zebra_delete_rnh(rnh, type);
 324 }
 325
 326 /* XXX move this utility function elsewhere? */
 327 static void addr2hostprefix(int af, const union g_addr *addr,
 328                             struct prefix *prefix)
 329 {
 330         switch (af) {
 331         case AF_INET:
 332                 prefix->family = AF_INET;
 333                 prefix->prefixlen = IPV4_MAX_BITLEN;
 334                 prefix->u.prefix4 = addr->ipv4;
 335                 break;
 336         case AF_INET6:
 337                 prefix->family = AF_INET6;
 338                 prefix->prefixlen = IPV6_MAX_BITLEN;
 339                 prefix->u.prefix6 = addr->ipv6;
 340                 break;
 341         default:
 342                 memset(prefix, 0, sizeof(*prefix));
 343                 zlog_debug("%s: unknown address family %d", __func__, af);
 344                 break;
 345         }
 346 }
 347
 348 void zebra_register_rnh_pseudowire(vrf_id_t vrf_id, struct zebra_pw *pw)
 349 {
 350         struct prefix nh;
 351         struct rnh *rnh;
 352         bool exists;
 353         struct zebra_vrf *zvrf;
 354
 355         zvrf = vrf_info_lookup(vrf_id);
 356         if (!zvrf)
 357                 return;
 358
 359         addr2hostprefix(pw->af, &pw->nexthop, &nh);
 360         rnh = zebra_add_rnh(&nh, vrf_id, RNH_NEXTHOP_TYPE, &exists);
 361         if (rnh && !listnode_lookup(rnh->zebra_pseudowire_list, pw)) {
 362                 listnode_add(rnh->zebra_pseudowire_list, pw);
 363                 pw->rnh = rnh;
 364                 zebra_evaluate_rnh(zvrf, family2afi(pw->af), 1,
 365                                    RNH_NEXTHOP_TYPE, &nh);
 366         }
 367 }
 368
 369 void zebra_deregister_rnh_pseudowire(vrf_id_t vrf_id, struct zebra_pw *pw)
 370 {
 371         struct rnh *rnh;
 372
 373         rnh = pw->rnh;
 374         if (!rnh)
 375                 return;
 376
 377         listnode_delete(rnh->zebra_pseudowire_list, pw);
 378         pw->rnh = NULL;
 379
 380         zebra_delete_rnh(rnh, RNH_NEXTHOP_TYPE);
 381 }
 382
 383 /* Clear the NEXTHOP_FLAG_RNH_FILTERED flags on all nexthops
 384  */
 385 static void zebra_rnh_clear_nexthop_rnh_filters(struct route_entry *re)
 386 {
 387         struct nexthop *nexthop;
 388
 389         if (re) {
 390                 for (nexthop = re->ng.nexthop; nexthop;
 391                      nexthop = nexthop->next) {
 392                         UNSET_FLAG(nexthop->flags, NEXTHOP_FLAG_RNH_FILTERED);
 393                 }
 394         }
 395 }
 396
 397 /* Apply the NHT route-map for a client to the route (and nexthops)
 398  * resolving a NH.
 399  */
 400 static int zebra_rnh_apply_nht_rmap(afi_t afi, struct zebra_vrf *zvrf,
 401                                     struct route_node *prn,
 402                                     struct route_entry *re, int proto)
 403 {
 404         int at_least_one = 0;
 405         struct nexthop *nexthop;
 406         route_map_result_t ret;
 407
 408         if (prn && re) {
 409                 for (nexthop = re->ng.nexthop; nexthop;
 410                      nexthop = nexthop->next) {
 411                         ret = zebra_nht_route_map_check(
 412                                 afi, proto, &prn->p, zvrf, re, nexthop);
 413                         if (ret != RMAP_DENYMATCH)
 414                                 at_least_one++; /* at least one valid NH */
 415                         else {
 416                                 SET_FLAG(nexthop->flags,
 417                                                 NEXTHOP_FLAG_RNH_FILTERED);
 418                         }
 419                 }
 420         }
 421         return (at_least_one);
 422 }
 423
 424 /*
 425  * Determine appropriate route (RE entry) resolving a tracked BGP route
 426  * for BGP route for import.
 427  */
 428 static struct route_entry *
 429 zebra_rnh_resolve_import_entry(struct zebra_vrf *zvrf, afi_t afi,
 430                                struct route_node *nrn, struct rnh *rnh,
 431                                struct route_node **prn)
 432 {
 433         struct route_table *route_table;
 434         struct route_node *rn;
 435         struct route_entry *re;
 436
 437         *prn = NULL;
 438
 439         route_table = zvrf->table[afi][SAFI_UNICAST];
 440         if (!route_table) // unexpected
 441                 return NULL;
 442
 443         rn = route_node_match(route_table, &nrn->p);
 444         if (!rn)
 445                 return NULL;
 446
 447         /* Unlock route node - we don't need to lock when walking the tree. */
 448         route_unlock_node(rn);
 449
 450         if (CHECK_FLAG(rnh->flags, ZEBRA_NHT_EXACT_MATCH)
 451             && !prefix_same(&nrn->p, &rn->p))
 452                 return NULL;
 453
 454         if (IS_ZEBRA_DEBUG_NHT_DETAILED) {
 455                 char buf[PREFIX_STRLEN];
 456                 char buf1[PREFIX_STRLEN];
 457
 458                 zlog_debug("%s: %u:%s Resolved Import Entry to %s",
 459                            __PRETTY_FUNCTION__, rnh->vrf_id,
 460                            prefix2str(&rnh->node->p, buf, sizeof(buf)),
 461                            srcdest_rnode2str(rn, buf1, sizeof(buf)));
 462         }
 463
 464         /* Identify appropriate route entry. */
 465         RNODE_FOREACH_RE (rn, re) {
 466                 if (!CHECK_FLAG(re->status, ROUTE_ENTRY_REMOVED)
 467                     && CHECK_FLAG(re->flags, ZEBRA_FLAG_SELECTED)
 468                     && !CHECK_FLAG(re->status, ROUTE_ENTRY_QUEUED)
 469                     && (re->type != ZEBRA_ROUTE_BGP))
 470                         break;
 471         }
 472
 473         if (re)
 474                 *prn = rn;
 475
 476         if (!re && IS_ZEBRA_DEBUG_NHT_DETAILED)
 477                 zlog_debug("\tRejected due to removed or is a bgp route");
 478
 479         return re;
 480 }
 481
 482 /*
 483  * See if a tracked route entry for import (by BGP) has undergone any
 484  * change, and if so, notify the client.
 485  */
 486 static void zebra_rnh_eval_import_check_entry(struct zebra_vrf *zvrf, afi_t afi,
 487                                               int force, struct route_node *nrn,
 488                                               struct rnh *rnh,
 489                                               struct route_node *prn,
 490                                               struct route_entry *re)
 491 {
 492         int state_changed = 0;
 493         struct zserv *client;
 494         char bufn[INET6_ADDRSTRLEN];
 495         struct listnode *node;
 496
 497         zebra_rnh_remove_from_routing_table(rnh);
 498         if (prn) {
 499                 prefix_copy(&rnh->resolved_route, &prn->p);
 500         } else {
 501                 int family = rnh->resolved_route.family;
 502
 503                 memset(&rnh->resolved_route.family, 0, sizeof(struct prefix));
 504                 rnh->resolved_route.family = family;
 505         }
 506         zebra_rnh_store_in_routing_table(rnh);
 507
 508         if (re && (rnh->state == NULL)) {
 509                 if (CHECK_FLAG(re->status, ROUTE_ENTRY_INSTALLED))
 510                         state_changed = 1;
 511         } else if (!re && (rnh->state != NULL))
 512                 state_changed = 1;
 513
 514         if (compare_state(re, rnh->state)) {
 515                 copy_state(rnh, re, nrn);
 516                 state_changed = 1;
 517         }
 518
 519         if (state_changed || force) {
 520                 if (IS_ZEBRA_DEBUG_NHT) {
 521                         prefix2str(&nrn->p, bufn, INET6_ADDRSTRLEN);
 522                         zlog_debug("%u:%s: Route import check %s %s",
 523                                    zvrf->vrf->vrf_id,
 524                                    bufn, rnh->state ? "passed" : "failed",
 525                                    state_changed ? "(state changed)" : "");
 526                 }
 527                 /* state changed, notify clients */
 528                 for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client)) {
 529                         send_client(rnh, client,
 530                                     RNH_IMPORT_CHECK_TYPE, zvrf->vrf->vrf_id);
 531                 }
 532         }
 533 }
 534
 535 /*
 536  * Notify clients registered for this nexthop about a change.
 537  */
 538 static void zebra_rnh_notify_protocol_clients(struct zebra_vrf *zvrf, afi_t afi,
 539                                               struct route_node *nrn,
 540                                               struct rnh *rnh,
 541                                               struct route_node *prn,
 542                                               struct route_entry *re)
 543 {
 544         struct listnode *node;
 545         struct zserv *client;
 546         char bufn[INET6_ADDRSTRLEN];
 547         char bufp[INET6_ADDRSTRLEN];
 548         int num_resolving_nh;
 549
 550         if (IS_ZEBRA_DEBUG_NHT) {
 551                 prefix2str(&nrn->p, bufn, INET6_ADDRSTRLEN);
 552                 if (prn && re) {
 553                         srcdest_rnode2str(prn, bufp, INET6_ADDRSTRLEN);
 554                         zlog_debug("%u:%s: NH resolved over route %s",
 555                                    zvrf->vrf->vrf_id, bufn, bufp);
 556                 } else
 557                         zlog_debug("%u:%s: NH has become unresolved",
 558                                    zvrf->vrf->vrf_id, bufn);
 559         }
 560
 561         for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client)) {
 562                 if (prn && re) {
 563                         /* Apply route-map for this client to route resolving
 564                          * this
 565                          * nexthop to see if it is filtered or not.
 566                          */
 567                         zebra_rnh_clear_nexthop_rnh_filters(re);
 568                         num_resolving_nh = zebra_rnh_apply_nht_rmap(
 569                                 afi, zvrf, prn, re, client->proto);
 570                         if (num_resolving_nh)
 571                                 rnh->filtered[client->proto] = 0;
 572                         else
 573                                 rnh->filtered[client->proto] = 1;
 574
 575                         if (IS_ZEBRA_DEBUG_NHT)
 576                                 zlog_debug(
 577                                         "%u:%s: Notifying client %s about NH %s",
 578                                         zvrf->vrf->vrf_id, bufn,
 579                                         zebra_route_string(client->proto),
 580                                         num_resolving_nh
 581                                                 ? ""
 582                                                 : "(filtered by route-map)");
 583                 } else {
 584                         rnh->filtered[client->proto] = 0;
 585                         if (IS_ZEBRA_DEBUG_NHT)
 586                                 zlog_debug(
 587                                         "%u:%s: Notifying client %s about NH (unreachable)",
 588                                         zvrf->vrf->vrf_id, bufn,
 589                                         zebra_route_string(client->proto));
 590                 }
 591
 592                 send_client(rnh, client, RNH_NEXTHOP_TYPE, zvrf->vrf->vrf_id);
 593         }
 594
 595         if (re)
 596                 zebra_rnh_clear_nexthop_rnh_filters(re);
 597 }
 598
 599 /*
 600  * Utility to determine whether a candidate nexthop is useable. We make this
 601  * check in a couple of places, so this is a single home for the logic we
 602  * use.
 603  */
 604 static bool rnh_nexthop_valid(const struct route_entry *re,
 605                               const struct nexthop *nh)
 606 {
 607         return (CHECK_FLAG(re->status, ROUTE_ENTRY_INSTALLED)
 608                 && CHECK_FLAG(nh->flags, NEXTHOP_FLAG_ACTIVE)
 609                 && !CHECK_FLAG(nh->flags, NEXTHOP_FLAG_RECURSIVE)
 610                 && !CHECK_FLAG(nh->flags, NEXTHOP_FLAG_DUPLICATE)
 611                 && !CHECK_FLAG(nh->flags, NEXTHOP_FLAG_RNH_FILTERED));
 612 }
 613
 614 /*
 615  * Determine appropriate route (route entry) resolving a tracked
 616  * nexthop.
 617  */
 618 static struct route_entry *
 619 zebra_rnh_resolve_nexthop_entry(struct zebra_vrf *zvrf, afi_t afi,
 620                                 struct route_node *nrn, struct rnh *rnh,
 621                                 struct route_node **prn)
 622 {
 623         struct route_table *route_table;
 624         struct route_node *rn;
 625         struct route_entry *re;
 626         struct nexthop *nexthop;
 627
 628         *prn = NULL;
 629
 630         route_table = zvrf->table[afi][SAFI_UNICAST];
 631         if (!route_table)
 632                 return NULL;
 633
 634         rn = route_node_match(route_table, &nrn->p);
 635         if (!rn)
 636                 return NULL;
 637
 638         /* Unlock route node - we don't need to lock when walking the tree. */
 639         route_unlock_node(rn);
 640
 641         /* While resolving nexthops, we may need to walk up the tree from the
 642          * most-specific match. Do similar logic as in zebra_rib.c
 643          */
 644         while (rn) {
 645                 if (IS_ZEBRA_DEBUG_NHT_DETAILED) {
 646                         char buf[PREFIX_STRLEN];
 647                         char buf1[PREFIX_STRLEN];
 648
 649                         zlog_debug("%s: %u:%s Possible Match to %s",
 650                                    __PRETTY_FUNCTION__, rnh->vrf_id,
 651                                    prefix2str(&rnh->node->p, buf, sizeof(buf)),
 652                                    srcdest_rnode2str(rn, buf1, sizeof(buf)));
 653                 }
 654
 655                 /* Do not resolve over default route unless allowed &&
 656                  * match route to be exact if so specified
 657                  */
 658                 if (is_default_prefix(&rn->p)
 659                     && !rnh_resolve_via_default(rn->p.family)) {
 660                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 661                                 zlog_debug(
 662                                         "\tNot allowed to resolve through default prefix");
 663                         return NULL;
 664                 }
 665
 666                 /* Identify appropriate route entry. */
 667                 RNODE_FOREACH_RE (rn, re) {
 668                         if (CHECK_FLAG(re->status, ROUTE_ENTRY_REMOVED)) {
 669                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 670                                         zlog_debug(
 671                                                 "\tRoute Entry %s removed",
 672                                                 zebra_route_string(re->type));
 673                                 continue;
 674                         }
 675                         if (!CHECK_FLAG(re->flags, ZEBRA_FLAG_SELECTED)) {
 676                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 677                                         zlog_debug(
 678                                                 "\tRoute Entry %s !selected",
 679                                                 zebra_route_string(re->type));
 680                                 continue;
 681                         }
 682
 683                         if (CHECK_FLAG(re->status, ROUTE_ENTRY_QUEUED)) {
 684                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 685                                         zlog_debug(
 686                                                 "\tRoute Entry %s queued",
 687                                                 zebra_route_string(re->type));
 688                                 continue;
 689                         }
 690
 691                         /* Just being SELECTED isn't quite enough - must
 692                          * have an installed nexthop to be useful.
 693                          */
 694                         for (ALL_NEXTHOPS(re->ng, nexthop)) {
 695                                 if (rnh_nexthop_valid(re, nexthop))
 696                                         break;
 697                         }
 698
 699                         if (nexthop == NULL) {
 700                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 701                                         zlog_debug(
 702                                                 "\tRoute Entry %s no nexthops",
 703                                                 zebra_route_string(re->type));
 704                                 continue;
 705                         }
 706
 707                         if (CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED)) {
 708                                 if ((re->type == ZEBRA_ROUTE_CONNECT)
 709                                     || (re->type == ZEBRA_ROUTE_STATIC))
 710                                         break;
 711                                 if (re->type == ZEBRA_ROUTE_NHRP) {
 712
 713                                         for (nexthop = re->ng.nexthop; nexthop;
 714                                              nexthop = nexthop->next)
 715                                                 if (nexthop->type
 716                                                     == NEXTHOP_TYPE_IFINDEX)
 717                                                         break;
 718                                         if (nexthop)
 719                                                 break;
 720                                 }
 721                         } else
 722                                 break;
 723                 }
 724
 725                 /* Route entry found, we're done; else, walk up the tree. */
 726                 if (re) {
 727                         *prn = rn;
 728                         return re;
 729                 }
 730
 731                 if (!CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED))
 732                         rn = rn->parent;
 733                 else {
 734                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 735                                 zlog_debug(
 736                                         "\tNexthop must be connected, cannot recurse up");
 737                         return NULL;
 738                 }
 739         }
 740
 741         return NULL;
 742 }
 743
 744 static void zebra_rnh_process_pseudowires(vrf_id_t vrfid, struct rnh *rnh)
 745 {
 746         struct zebra_pw *pw;
 747         struct listnode *node;
 748
 749         for (ALL_LIST_ELEMENTS_RO(rnh->zebra_pseudowire_list, node, pw))
 750                 zebra_pw_update(pw);
 751 }
 752
 753 /*
 754  * See if a tracked nexthop entry has undergone any change, and if so,
 755  * take appropriate action; this involves notifying any clients and/or
 756  * scheduling dependent static routes for processing.
 757  */
 758 static void zebra_rnh_eval_nexthop_entry(struct zebra_vrf *zvrf, afi_t afi,
 759                                          int force, struct route_node *nrn,
 760                                          struct rnh *rnh,
 761                                          struct route_node *prn,
 762                                          struct route_entry *re)
 763 {
 764         int state_changed = 0;
 765
 766         /* If we're resolving over a different route, resolution has changed or
 767          * the resolving route has some change (e.g., metric), there is a state
 768          * change.
 769          */
 770         zebra_rnh_remove_from_routing_table(rnh);
 771         if (!prefix_same(&rnh->resolved_route, prn ? &prn->p : NULL)) {
 772                 if (prn)
 773                         prefix_copy(&rnh->resolved_route, &prn->p);
 774                 else {
 775                         /*
 776                          * Just quickly store the family of the resolved
 777                          * route so that we can reset it in a second here
 778                          */
 779                         int family = rnh->resolved_route.family;
 780
 781                         memset(&rnh->resolved_route, 0, sizeof(struct prefix));
 782                         rnh->resolved_route.family = family;
 783                 }
 784
 785                 copy_state(rnh, re, nrn);
 786                 state_changed = 1;
 787         } else if (compare_state(re, rnh->state)) {
 788                 copy_state(rnh, re, nrn);
 789                 state_changed = 1;
 790         }
 791         zebra_rnh_store_in_routing_table(rnh);
 792
 793         if (state_changed || force) {
 794                 /* NOTE: Use the "copy" of resolving route stored in 'rnh' i.e.,
 795                  * rnh->state.
 796                  */
 797                 /* Notify registered protocol clients. */
 798                 zebra_rnh_notify_protocol_clients(zvrf, afi, nrn, rnh, prn,
 799                                                   rnh->state);
 800
 801                 /* Process pseudowires attached to this nexthop */
 802                 zebra_rnh_process_pseudowires(zvrf->vrf->vrf_id, rnh);
 803         }
 804 }
 805
 806 /* Evaluate one tracked entry */
 807 static void zebra_rnh_evaluate_entry(struct zebra_vrf *zvrf, afi_t afi,
 808                                      int force, rnh_type_t type,
 809                                      struct route_node *nrn)
 810 {
 811         struct rnh *rnh;
 812         struct route_entry *re;
 813         struct route_node *prn;
 814         char bufn[INET6_ADDRSTRLEN];
 815
 816         if (IS_ZEBRA_DEBUG_NHT) {
 817                 prefix2str(&nrn->p, bufn, INET6_ADDRSTRLEN);
 818                 zlog_debug("%u:%s: Evaluate RNH, type %s %s", zvrf->vrf->vrf_id,
 819                            bufn, rnh_type2str(type), force ? "(force)" : "");
 820         }
 821
 822         rnh = nrn->info;
 823
 824         /* Identify route entry (RE) resolving this tracked entry. */
 825         if (type == RNH_IMPORT_CHECK_TYPE)
 826                 re = zebra_rnh_resolve_import_entry(zvrf, afi, nrn, rnh, &prn);
 827         else
 828                 re = zebra_rnh_resolve_nexthop_entry(zvrf, afi, nrn, rnh, &prn);
 829
 830         /* If the entry cannot be resolved and that is also the existing state,
 831          * there is nothing further to do.
 832          */
 833         if (!re && rnh->state == NULL && !force)
 834                 return;
 835
 836         /* Process based on type of entry. */
 837         if (type == RNH_IMPORT_CHECK_TYPE)
 838                 zebra_rnh_eval_import_check_entry(zvrf, afi, force, nrn, rnh,
 839                                                   prn, re);
 840         else
 841                 zebra_rnh_eval_nexthop_entry(zvrf, afi, force, nrn, rnh, prn,
 842                                              re);
 843 }
 844
 845 /*
 846  * Clear the ROUTE_ENTRY_NEXTHOPS_CHANGED flag
 847  * from the re entries.
 848  *
 849  * Please note we are doing this *after* we have
 850  * notified the world about each nexthop as that
 851  * we can have a situation where one re entry
 852  * covers multiple nexthops we are interested in.
 853  */
 854 static void zebra_rnh_clear_nhc_flag(struct zebra_vrf *zvrf, afi_t afi,
 855                                      rnh_type_t type, struct route_node *nrn)
 856 {
 857         struct rnh *rnh;
 858         struct route_entry *re;
 859         struct route_node *prn;
 860
 861         rnh = nrn->info;
 862
 863         /* Identify route entry (RIB) resolving this tracked entry. */
 864         if (type == RNH_IMPORT_CHECK_TYPE)
 865                 re = zebra_rnh_resolve_import_entry(zvrf, afi, nrn, rnh,
 866                                                     &prn);
 867         else
 868                 re = zebra_rnh_resolve_nexthop_entry(zvrf, afi, nrn, rnh,
 869                                                      &prn);
 870
 871         if (re)
 872                 UNSET_FLAG(re->status, ROUTE_ENTRY_LABELS_CHANGED);
 873 }
 874
 875 /* Evaluate all tracked entries (nexthops or routes for import into BGP)
 876  * of a particular VRF and address-family or a specific prefix.
 877  */
 878 void zebra_evaluate_rnh(struct zebra_vrf *zvrf, afi_t afi, int force,
 879                         rnh_type_t type, struct prefix *p)
 880 {
 881         struct route_table *rnh_table;
 882         struct route_node *nrn;
 883
 884         rnh_table = get_rnh_table(zvrf->vrf->vrf_id, afi, type);
 885         if (!rnh_table) // unexpected
 886                 return;
 887
 888         if (p) {
 889                 /* Evaluating a specific entry, make sure it exists. */
 890                 nrn = route_node_lookup(rnh_table, p);
 891                 if (nrn && nrn->info)
 892                         zebra_rnh_evaluate_entry(zvrf, afi, force, type, nrn);
 893
 894                 if (nrn)
 895                         route_unlock_node(nrn);
 896         } else {
 897                 /* Evaluate entire table. */
 898                 nrn = route_top(rnh_table);
 899                 while (nrn) {
 900                         if (nrn->info)
 901                                 zebra_rnh_evaluate_entry(zvrf, afi, force, type,
 902                                                          nrn);
 903                         nrn = route_next(nrn); /* this will also unlock nrn */
 904                 }
 905                 nrn = route_top(rnh_table);
 906                 while (nrn) {
 907                         if (nrn->info)
 908                                 zebra_rnh_clear_nhc_flag(zvrf, afi, type, nrn);
 909                         nrn = route_next(nrn); /* this will also unlock nrn */
 910                 }
 911         }
 912 }
 913
 914 void zebra_print_rnh_table(vrf_id_t vrfid, afi_t afi, struct vty *vty,
 915                            rnh_type_t type, struct prefix *p)
 916 {
 917         struct route_table *table;
 918         struct route_node *rn;
 919
 920         table = get_rnh_table(vrfid, afi, type);
 921         if (!table) {
 922                 zlog_debug("print_rnhs: rnh table not found");
 923                 return;
 924         }
 925
 926         for (rn = route_top(table); rn; rn = route_next(rn)) {
 927                 if (p && prefix_cmp(&rn->p, p) != 0)
 928                         continue;
 929
 930                 if (rn->info)
 931                         print_rnh(rn, vty);
 932         }
 933 }
 934
 935 /**
 936  * free_state - free up the re structure associated with the rnh.
 937  */
 938 static void free_state(vrf_id_t vrf_id, struct route_entry *re,
 939                        struct route_node *rn)
 940 {
 941         if (!re)
 942                 return;
 943
 944         /* free RE and nexthops */
 945         nexthops_free(re->ng.nexthop);
 946         XFREE(MTYPE_RE, re);
 947 }
 948
 949 static void copy_state(struct rnh *rnh, struct route_entry *re,
 950                        struct route_node *rn)
 951 {
 952         struct route_entry *state;
 953
 954         if (rnh->state) {
 955                 free_state(rnh->vrf_id, rnh->state, rn);
 956                 rnh->state = NULL;
 957         }
 958
 959         if (!re)
 960                 return;
 961
 962         state = XCALLOC(MTYPE_RE, sizeof(struct route_entry));
 963         state->type = re->type;
 964         state->distance = re->distance;
 965         state->metric = re->metric;
 966         state->vrf_id = re->vrf_id;
 967         state->status = re->status;
 968
 969         route_entry_copy_nexthops(state, re->ng.nexthop);
 970         rnh->state = state;
 971 }
 972
 973 static int compare_state(struct route_entry *r1, struct route_entry *r2)
 974 {
 975         if (!r1 && !r2)
 976                 return 0;
 977
 978         if ((!r1 && r2) || (r1 && !r2))
 979                 return 1;
 980
 981         if (r1->distance != r2->distance)
 982                 return 1;
 983
 984         if (r1->metric != r2->metric)
 985                 return 1;
 986
 987         if (r1->nexthop_num != r2->nexthop_num)
 988                 return 1;
 989
 990         if (nexthop_group_hash(&r1->ng) != nexthop_group_hash(&r2->ng))
 991                 return 1;
 992
 993         return 0;
 994 }
 995
 996 static int send_client(struct rnh *rnh, struct zserv *client, rnh_type_t type,
 997                        vrf_id_t vrf_id)
 998 {
 999         struct stream *s;
1000         struct route_entry *re;
1001         unsigned long nump;
1002         uint8_t num;
1003         struct nexthop *nh;
1004         struct route_node *rn;
1005         int cmd = (type == RNH_IMPORT_CHECK_TYPE) ? ZEBRA_IMPORT_CHECK_UPDATE
1006                                                   : ZEBRA_NEXTHOP_UPDATE;
1007
1008         rn = rnh->node;
1009         re = rnh->state;
1010
1011         /* Get output stream. */
1012         s = stream_new(ZEBRA_MAX_PACKET_SIZ);
1013
1014         zclient_create_header(s, cmd, vrf_id);
1015
1016         stream_putw(s, rn->p.family);
1017         switch (rn->p.family) {
1018         case AF_INET:
1019                 stream_putc(s, rn->p.prefixlen);
1020                 stream_put_in_addr(s, &rn->p.u.prefix4);
1021                 break;
1022         case AF_INET6:
1023                 stream_putc(s, rn->p.prefixlen);
1024                 stream_put(s, &rn->p.u.prefix6, IPV6_MAX_BYTELEN);
1025                 break;
1026         default:
1027                 flog_err(EC_ZEBRA_RNH_UNKNOWN_FAMILY,
1028                          "%s: Unknown family (%d) notification attempted\n",
1029                          __FUNCTION__, rn->p.family);
1030                 break;
1031         }
1032         if (re) {
1033                 stream_putc(s, re->type);
1034                 stream_putw(s, re->instance);
1035                 stream_putc(s, re->distance);
1036                 stream_putl(s, re->metric);
1037                 num = 0;
1038                 nump = stream_get_endp(s);
1039                 stream_putc(s, 0);
1040                 for (ALL_NEXTHOPS(re->ng, nh))
1041                         if (rnh_nexthop_valid(re, nh)) {
1042                                 stream_putl(s, nh->vrf_id);
1043                                 stream_putc(s, nh->type);
1044                                 switch (nh->type) {
1045                                 case NEXTHOP_TYPE_IPV4:
1046                                 case NEXTHOP_TYPE_IPV4_IFINDEX:
1047                                         stream_put_in_addr(s, &nh->gate.ipv4);
1048                                         stream_putl(s, nh->ifindex);
1049                                         break;
1050                                 case NEXTHOP_TYPE_IFINDEX:
1051                                         stream_putl(s, nh->ifindex);
1052                                         break;
1053                                 case NEXTHOP_TYPE_IPV6:
1054                                 case NEXTHOP_TYPE_IPV6_IFINDEX:
1055                                         stream_put(s, &nh->gate.ipv6, 16);
1056                                         stream_putl(s, nh->ifindex);
1057                                         break;
1058                                 default:
1059                                         /* do nothing */
1060                                         break;
1061                                 }
1062                                 if (nh->nh_label) {
1063                                         stream_putc(s,
1064                                                     nh->nh_label->num_labels);
1065                                         if (nh->nh_label->num_labels)
1066                                                 stream_put(
1067                                                         s,
1068                                                         &nh->nh_label->label[0],
1069                                                         nh->nh_label->num_labels
1070                                                                 * sizeof(mpls_label_t));
1071                                 } else
1072                                         stream_putc(s, 0);
1073                                 num++;
1074                         }
1075                 stream_putc_at(s, nump, num);
1076         } else {
1077                 stream_putc(s, 0); // type
1078                 stream_putw(s, 0); // instance
1079                 stream_putc(s, 0); // distance
1080                 stream_putl(s, 0); // metric
1081                 stream_putc(s, 0); // nexthops
1082         }
1083         stream_putw_at(s, 0, stream_get_endp(s));
1084
1085         client->nh_last_upd_time = monotime(NULL);
1086         client->last_write_cmd = cmd;
1087         return zserv_send_message(client, s);
1088 }
1089
1090 static void print_nh(struct nexthop *nexthop, struct vty *vty)
1091 {
1092         char buf[BUFSIZ];
1093         struct zebra_ns *zns = zebra_ns_lookup(nexthop->vrf_id);
1094
1095         switch (nexthop->type) {
1096         case NEXTHOP_TYPE_IPV4:
1097         case NEXTHOP_TYPE_IPV4_IFINDEX:
1098                 vty_out(vty, " via %s", inet_ntoa(nexthop->gate.ipv4));
1099                 if (nexthop->ifindex)
1100                         vty_out(vty, ", %s",
1101                                 ifindex2ifname_per_ns(zns, nexthop->ifindex));
1102                 break;
1103         case NEXTHOP_TYPE_IPV6:
1104         case NEXTHOP_TYPE_IPV6_IFINDEX:
1105                 vty_out(vty, " %s",
1106                         inet_ntop(AF_INET6, &nexthop->gate.ipv6, buf, BUFSIZ));
1107                 if (nexthop->ifindex)
1108                         vty_out(vty, ", via %s",
1109                                 ifindex2ifname_per_ns(zns, nexthop->ifindex));
1110                 break;
1111         case NEXTHOP_TYPE_IFINDEX:
1112                 vty_out(vty, " is directly connected, %s",
1113                         ifindex2ifname_per_ns(zns, nexthop->ifindex));
1114                 break;
1115         case NEXTHOP_TYPE_BLACKHOLE:
1116                 vty_out(vty, " is directly connected, Null0");
1117                 break;
1118         default:
1119                 break;
1120         }
1121         vty_out(vty, "\n");
1122 }
1123
1124 static void print_rnh(struct route_node *rn, struct vty *vty)
1125 {
1126         struct rnh *rnh;
1127         struct nexthop *nexthop;
1128         struct listnode *node;
1129         struct zserv *client;
1130         char buf[BUFSIZ];
1131
1132         rnh = rn->info;
1133         vty_out(vty, "%s%s\n",
1134                 inet_ntop(rn->p.family, &rn->p.u.prefix, buf, BUFSIZ),
1135                 CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED) ? "(Connected)"
1136                                                             : "");
1137         if (rnh->state) {
1138                 vty_out(vty, " resolved via %s\n",
1139                         zebra_route_string(rnh->state->type));
1140                 for (nexthop = rnh->state->ng.nexthop; nexthop;
1141                      nexthop = nexthop->next)
1142                         print_nh(nexthop, vty);
1143         } else
1144                 vty_out(vty, " unresolved%s\n",
1145                         CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED)
1146                                 ? "(Connected)"
1147                                 : "");
1148
1149         vty_out(vty, " Client list:");
1150         for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client))
1151                 vty_out(vty, " %s(fd %d)%s", zebra_route_string(client->proto),
1152                         client->sock,
1153                         rnh->filtered[client->proto] ? "(filtered)" : "");
1154         if (!list_isempty(rnh->zebra_pseudowire_list))
1155                 vty_out(vty, " zebra[pseudowires]");
1156         vty_out(vty, "\n");
1157 }
1158
1159 static int zebra_cleanup_rnh_client(vrf_id_t vrf_id, afi_t afi,
1160                                     struct zserv *client, rnh_type_t type)
1161 {
1162         struct route_table *ntable;
1163         struct route_node *nrn;
1164         struct rnh *rnh;
1165
1166         if (IS_ZEBRA_DEBUG_NHT)
1167                 zlog_debug("%u: Client %s RNH cleanup for family %s type %s",
1168                            vrf_id, zebra_route_string(client->proto),
1169                            afi2str(afi), rnh_type2str(type));
1170
1171         ntable = get_rnh_table(vrf_id, afi, type);
1172         if (!ntable) {
1173                 zlog_debug("cleanup_rnh_client: rnh table not found");
1174                 return -1;
1175         }
1176
1177         for (nrn = route_top(ntable); nrn; nrn = route_next(nrn)) {
1178                 if (!nrn->info)
1179                         continue;
1180
1181                 rnh = nrn->info;
1182                 zebra_remove_rnh_client(rnh, client, type);
1183         }
1184         return 1;
1185 }
1186
1187 /* Cleanup registered nexthops (across VRFs) upon client disconnect. */
1188 static int zebra_client_cleanup_rnh(struct zserv *client)
1189 {
1190         struct vrf *vrf;
1191         struct zebra_vrf *zvrf;
1192
1193         RB_FOREACH (vrf, vrf_id_head, &vrfs_by_id) {
1194                 zvrf = vrf->info;
1195                 if (zvrf) {
1196                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP, client,
1197                                                  RNH_NEXTHOP_TYPE);
1198                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP6, client,
1199                                                  RNH_NEXTHOP_TYPE);
1200                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP, client,
1201                                                  RNH_IMPORT_CHECK_TYPE);
1202                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP6, client,
1203                                                  RNH_IMPORT_CHECK_TYPE);
1204                         if (client->proto == ZEBRA_ROUTE_LDP) {
1205                                 hash_iterate(zvrf->lsp_table,
1206                                              mpls_ldp_lsp_uninstall_all,
1207                                              zvrf->lsp_table);
1208                                 mpls_ldp_ftn_uninstall_all(zvrf, AFI_IP);
1209                                 mpls_ldp_ftn_uninstall_all(zvrf, AFI_IP6);
1210                         }
1211                 }
1212         }
1213
1214         return 0;
1215 }