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/zebra_srte.h"
  50 #include "zebra/interface.h"
  51 #include "zebra/zebra_errors.h"
  52
  53 DEFINE_MTYPE_STATIC(ZEBRA, RNH, "Nexthop tracking object");
  54
  55 /* UI controls whether to notify about changes that only involve backup
  56  * nexthops. Default is to notify all changes.
  57  */
  58 static bool rnh_hide_backups;
  59
  60 static void free_state(vrf_id_t vrf_id, struct route_entry *re,
  61                        struct route_node *rn);
  62 static void copy_state(struct rnh *rnh, const struct route_entry *re,
  63                        struct route_node *rn);
  64 static bool compare_state(struct route_entry *r1, struct route_entry *r2);
  65 static void print_rnh(struct route_node *rn, struct vty *vty);
  66 static int zebra_client_cleanup_rnh(struct zserv *client);
  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                                                 enum rnh_type 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 static void zebra_rnh_remove_from_routing_table(struct rnh *rnh)
  94 {
  95         struct zebra_vrf *zvrf = zebra_vrf_lookup_by_id(rnh->vrf_id);
  96         struct route_table *table = zvrf->table[rnh->afi][SAFI_UNICAST];
  97         struct route_node *rn;
  98         rib_dest_t *dest;
  99
 100         if (!table)
 101                 return;
 102
 103         rn = route_node_match(table, &rnh->resolved_route);
 104         if (!rn)
 105                 return;
 106
 107         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 108                 zlog_debug("%s: %s(%u):%pRN removed from tracking on %pRN",
 109                            __func__, VRF_LOGNAME(zvrf->vrf), rnh->vrf_id,
 110                            rnh->node, rn);
 111
 112         dest = rib_dest_from_rnode(rn);
 113         rnh_list_del(&dest->nht, rnh);
 114         route_unlock_node(rn);
 115 }
 116
 117 static void zebra_rnh_store_in_routing_table(struct rnh *rnh)
 118 {
 119         struct zebra_vrf *zvrf = zebra_vrf_lookup_by_id(rnh->vrf_id);
 120         struct route_table *table = zvrf->table[rnh->afi][SAFI_UNICAST];
 121         struct route_node *rn;
 122         rib_dest_t *dest;
 123
 124         rn = route_node_match(table, &rnh->resolved_route);
 125         if (!rn)
 126                 return;
 127
 128         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 129                 zlog_debug("%s: %s(%u):%pRN added for tracking on %pRN",
 130                            __func__, VRF_LOGNAME(zvrf->vrf), rnh->vrf_id,
 131                            rnh->node, rn);
 132
 133         dest = rib_dest_from_rnode(rn);
 134         rnh_list_add_tail(&dest->nht, rnh);
 135         route_unlock_node(rn);
 136 }
 137
 138 struct rnh *zebra_add_rnh(struct prefix *p, vrf_id_t vrfid, enum rnh_type type,
 139                           bool *exists)
 140 {
 141         struct route_table *table;
 142         struct route_node *rn;
 143         struct rnh *rnh = NULL;
 144         afi_t afi = family2afi(p->family);
 145
 146         if (IS_ZEBRA_DEBUG_NHT) {
 147                 struct vrf *vrf = vrf_lookup_by_id(vrfid);
 148
 149                 zlog_debug("%s(%u): Add RNH %pFX type %s", VRF_LOGNAME(vrf),
 150                            vrfid, p, rnh_type2str(type));
 151         }
 152         table = get_rnh_table(vrfid, afi, type);
 153         if (!table) {
 154                 struct vrf *vrf = vrf_lookup_by_id(vrfid);
 155
 156                 flog_warn(EC_ZEBRA_RNH_NO_TABLE,
 157                           "%s(%u): Add RNH %pFX type %s - table not found",
 158                           VRF_LOGNAME(vrf), vrfid, p, rnh_type2str(type));
 159                 *exists = false;
 160                 return NULL;
 161         }
 162
 163         /* Make it sure prefixlen is applied to the prefix. */
 164         apply_mask(p);
 165
 166         /* Lookup (or add) route node.*/
 167         rn = route_node_get(table, p);
 168
 169         if (!rn->info) {
 170                 rnh = XCALLOC(MTYPE_RNH, sizeof(struct rnh));
 171
 172                 /*
 173                  * The resolved route is already 0.0.0.0/0 or
 174                  * 0::0/0 due to the calloc right above, but
 175                  * we should set the family so that future
 176                  * comparisons can just be done
 177                  */
 178                 rnh->resolved_route.family = p->family;
 179                 rnh->client_list = list_new();
 180                 rnh->vrf_id = vrfid;
 181                 rnh->type = type;
 182                 rnh->seqno = 0;
 183                 rnh->afi = afi;
 184                 rnh->zebra_pseudowire_list = list_new();
 185                 route_lock_node(rn);
 186                 rn->info = rnh;
 187                 rnh->node = rn;
 188                 *exists = false;
 189
 190                 zebra_rnh_store_in_routing_table(rnh);
 191         } else
 192                 *exists = true;
 193
 194         route_unlock_node(rn);
 195         return (rn->info);
 196 }
 197
 198 struct rnh *zebra_lookup_rnh(struct prefix *p, vrf_id_t vrfid,
 199                              enum rnh_type type)
 200 {
 201         struct route_table *table;
 202         struct route_node *rn;
 203
 204         table = get_rnh_table(vrfid, family2afi(PREFIX_FAMILY(p)), type);
 205         if (!table)
 206                 return NULL;
 207
 208         /* Make it sure prefixlen is applied to the prefix. */
 209         apply_mask(p);
 210
 211         /* Lookup route node.*/
 212         rn = route_node_lookup(table, p);
 213         if (!rn)
 214                 return NULL;
 215
 216         route_unlock_node(rn);
 217         return (rn->info);
 218 }
 219
 220 void zebra_free_rnh(struct rnh *rnh)
 221 {
 222         struct zebra_vrf *zvrf;
 223         struct route_table *table;
 224
 225         zebra_rnh_remove_from_routing_table(rnh);
 226         rnh->flags |= ZEBRA_NHT_DELETED;
 227         list_delete(&rnh->client_list);
 228         list_delete(&rnh->zebra_pseudowire_list);
 229
 230         zvrf = zebra_vrf_lookup_by_id(rnh->vrf_id);
 231         table = zvrf->table[family2afi(rnh->resolved_route.family)][SAFI_UNICAST];
 232
 233         if (table) {
 234                 struct route_node *rern;
 235
 236                 rern = route_node_match(table, &rnh->resolved_route);
 237                 if (rern) {
 238                         rib_dest_t *dest;
 239
 240                         route_unlock_node(rern);
 241
 242                         dest = rib_dest_from_rnode(rern);
 243                         rnh_list_del(&dest->nht, rnh);
 244                 }
 245         }
 246         free_state(rnh->vrf_id, rnh->state, rnh->node);
 247         XFREE(MTYPE_RNH, rnh);
 248 }
 249
 250 static void zebra_delete_rnh(struct rnh *rnh, enum rnh_type type)
 251 {
 252         struct route_node *rn;
 253
 254         if (!list_isempty(rnh->client_list)
 255             || !list_isempty(rnh->zebra_pseudowire_list))
 256                 return;
 257
 258         if ((rnh->flags & ZEBRA_NHT_DELETED) || !(rn = rnh->node))
 259                 return;
 260
 261         if (IS_ZEBRA_DEBUG_NHT) {
 262                 struct vrf *vrf = vrf_lookup_by_id(rnh->vrf_id);
 263
 264                 zlog_debug("%s(%u): Del RNH %pRN type %s", VRF_LOGNAME(vrf),
 265                            rnh->vrf_id, rnh->node, rnh_type2str(type));
 266         }
 267
 268         zebra_free_rnh(rnh);
 269         rn->info = NULL;
 270         route_unlock_node(rn);
 271 }
 272
 273 /*
 274  * This code will send to the registering client
 275  * the looked up rnh.
 276  * For a rnh that was created, there is no data
 277  * so it will send an empty nexthop group
 278  * If rnh exists then we know it has been evaluated
 279  * and as such it will have a resolved rnh.
 280  */
 281 void zebra_add_rnh_client(struct rnh *rnh, struct zserv *client,
 282                           enum rnh_type type, vrf_id_t vrf_id)
 283 {
 284         if (IS_ZEBRA_DEBUG_NHT) {
 285                 struct vrf *vrf = vrf_lookup_by_id(vrf_id);
 286
 287                 zlog_debug("%s(%u): Client %s registers for RNH %pRN type %s",
 288                            VRF_LOGNAME(vrf), vrf_id,
 289                            zebra_route_string(client->proto), rnh->node,
 290                            rnh_type2str(type));
 291         }
 292         if (!listnode_lookup(rnh->client_list, client))
 293                 listnode_add(rnh->client_list, client);
 294
 295         /*
 296          * We always need to respond with known information,
 297          * currently multiple daemons expect this behavior
 298          */
 299         zebra_send_rnh_update(rnh, client, type, vrf_id, 0);
 300 }
 301
 302 void zebra_remove_rnh_client(struct rnh *rnh, struct zserv *client,
 303                              enum rnh_type type)
 304 {
 305         if (IS_ZEBRA_DEBUG_NHT) {
 306                 struct vrf *vrf = vrf_lookup_by_id(rnh->vrf_id);
 307
 308                 zlog_debug("Client %s unregisters for RNH %s(%u)%pRN type %s",
 309                            zebra_route_string(client->proto), VRF_LOGNAME(vrf),
 310                            vrf->vrf_id, rnh->node, rnh_type2str(type));
 311         }
 312         listnode_delete(rnh->client_list, client);
 313         zebra_delete_rnh(rnh, type);
 314 }
 315
 316 /* XXX move this utility function elsewhere? */
 317 static void addr2hostprefix(int af, const union g_addr *addr,
 318                             struct prefix *prefix)
 319 {
 320         switch (af) {
 321         case AF_INET:
 322                 prefix->family = AF_INET;
 323                 prefix->prefixlen = IPV4_MAX_BITLEN;
 324                 prefix->u.prefix4 = addr->ipv4;
 325                 break;
 326         case AF_INET6:
 327                 prefix->family = AF_INET6;
 328                 prefix->prefixlen = IPV6_MAX_BITLEN;
 329                 prefix->u.prefix6 = addr->ipv6;
 330                 break;
 331         default:
 332                 memset(prefix, 0, sizeof(*prefix));
 333                 zlog_warn("%s: unknown address family %d", __func__, af);
 334                 break;
 335         }
 336 }
 337
 338 void zebra_register_rnh_pseudowire(vrf_id_t vrf_id, struct zebra_pw *pw,
 339                                    bool *nht_exists)
 340 {
 341         struct prefix nh;
 342         struct rnh *rnh;
 343         bool exists;
 344         struct zebra_vrf *zvrf;
 345
 346         *nht_exists = false;
 347
 348         zvrf = vrf_info_lookup(vrf_id);
 349         if (!zvrf)
 350                 return;
 351
 352         addr2hostprefix(pw->af, &pw->nexthop, &nh);
 353         rnh = zebra_add_rnh(&nh, vrf_id, RNH_NEXTHOP_TYPE, &exists);
 354         if (!rnh)
 355                 return;
 356
 357         if (!listnode_lookup(rnh->zebra_pseudowire_list, pw)) {
 358                 listnode_add(rnh->zebra_pseudowire_list, pw);
 359                 pw->rnh = rnh;
 360                 zebra_evaluate_rnh(zvrf, family2afi(pw->af), 1,
 361                                    RNH_NEXTHOP_TYPE, &nh);
 362         } else
 363                 *nht_exists = true;
 364 }
 365
 366 void zebra_deregister_rnh_pseudowire(vrf_id_t vrf_id, struct zebra_pw *pw)
 367 {
 368         struct rnh *rnh;
 369
 370         rnh = pw->rnh;
 371         if (!rnh)
 372                 return;
 373
 374         listnode_delete(rnh->zebra_pseudowire_list, pw);
 375         pw->rnh = NULL;
 376
 377         zebra_delete_rnh(rnh, RNH_NEXTHOP_TYPE);
 378 }
 379
 380 /* Clear the NEXTHOP_FLAG_RNH_FILTERED flags on all nexthops
 381  */
 382 static void zebra_rnh_clear_nexthop_rnh_filters(struct route_entry *re)
 383 {
 384         struct nexthop *nexthop;
 385
 386         if (re) {
 387                 for (nexthop = re->nhe->nhg.nexthop; nexthop;
 388                      nexthop = nexthop->next) {
 389                         UNSET_FLAG(nexthop->flags, NEXTHOP_FLAG_RNH_FILTERED);
 390                 }
 391         }
 392 }
 393
 394 /* Apply the NHT route-map for a client to the route (and nexthops)
 395  * resolving a NH.
 396  */
 397 static int zebra_rnh_apply_nht_rmap(afi_t afi, struct zebra_vrf *zvrf,
 398                                     struct route_node *prn,
 399                                     struct route_entry *re, int proto)
 400 {
 401         int at_least_one = 0;
 402         struct nexthop *nexthop;
 403         route_map_result_t ret;
 404
 405         if (prn && re) {
 406                 for (nexthop = re->nhe->nhg.nexthop; nexthop;
 407                      nexthop = nexthop->next) {
 408                         ret = zebra_nht_route_map_check(
 409                                 afi, proto, &prn->p, zvrf, re, nexthop);
 410                         if (ret != RMAP_DENYMATCH)
 411                                 at_least_one++; /* at least one valid NH */
 412                         else {
 413                                 SET_FLAG(nexthop->flags,
 414                                          NEXTHOP_FLAG_RNH_FILTERED);
 415                         }
 416                 }
 417         }
 418         return (at_least_one);
 419 }
 420
 421 /*
 422  * Determine appropriate route (RE entry) resolving a tracked BGP route
 423  * for BGP route for import.
 424  */
 425 static struct route_entry *
 426 zebra_rnh_resolve_import_entry(struct zebra_vrf *zvrf, afi_t afi,
 427                                struct route_node *nrn, struct rnh *rnh,
 428                                struct route_node **prn)
 429 {
 430         struct route_table *route_table;
 431         struct route_node *rn;
 432         struct route_entry *re;
 433
 434         *prn = NULL;
 435
 436         route_table = zvrf->table[afi][SAFI_UNICAST];
 437         if (!route_table) // unexpected
 438                 return NULL;
 439
 440         rn = route_node_match(route_table, &nrn->p);
 441         if (!rn)
 442                 return NULL;
 443
 444         /* Unlock route node - we don't need to lock when walking the tree. */
 445         route_unlock_node(rn);
 446
 447         if (CHECK_FLAG(rnh->flags, ZEBRA_NHT_EXACT_MATCH)
 448             && !prefix_same(&nrn->p, &rn->p))
 449                 return NULL;
 450
 451         if (IS_ZEBRA_DEBUG_NHT_DETAILED) {
 452                 zlog_debug("%s: %s(%u):%pRN Resolved Import Entry to %pRN",
 453                            __func__, VRF_LOGNAME(zvrf->vrf), rnh->vrf_id,
 454                            rnh->node, rn);
 455         }
 456
 457         /* Identify appropriate route entry. */
 458         RNODE_FOREACH_RE (rn, re) {
 459                 if (!CHECK_FLAG(re->status, ROUTE_ENTRY_REMOVED)
 460                     && CHECK_FLAG(re->flags, ZEBRA_FLAG_SELECTED)
 461                     && !CHECK_FLAG(re->status, ROUTE_ENTRY_QUEUED)
 462                     && (re->type != ZEBRA_ROUTE_BGP))
 463                         break;
 464         }
 465
 466         if (re)
 467                 *prn = rn;
 468
 469         if (!re && IS_ZEBRA_DEBUG_NHT_DETAILED)
 470                 zlog_debug("        Rejected due to removed or is a bgp route");
 471
 472         return re;
 473 }
 474
 475 /*
 476  * See if a tracked route entry for import (by BGP) has undergone any
 477  * change, and if so, notify the client.
 478  */
 479 static void zebra_rnh_eval_import_check_entry(struct zebra_vrf *zvrf, afi_t afi,
 480                                               int force, struct route_node *nrn,
 481                                               struct rnh *rnh,
 482                                               struct route_node *prn,
 483                                               struct route_entry *re)
 484 {
 485         int state_changed = 0;
 486         struct zserv *client;
 487         struct listnode *node;
 488
 489         zebra_rnh_remove_from_routing_table(rnh);
 490         if (prn) {
 491                 prefix_copy(&rnh->resolved_route, &prn->p);
 492         } else {
 493                 int family = rnh->resolved_route.family;
 494
 495                 memset(&rnh->resolved_route.family, 0, sizeof(struct prefix));
 496                 rnh->resolved_route.family = family;
 497         }
 498         zebra_rnh_store_in_routing_table(rnh);
 499
 500         if (re && (rnh->state == NULL)) {
 501                 if (CHECK_FLAG(re->status, ROUTE_ENTRY_INSTALLED))
 502                         state_changed = 1;
 503         } else if (!re && (rnh->state != NULL))
 504                 state_changed = 1;
 505
 506         if (compare_state(re, rnh->state)) {
 507                 copy_state(rnh, re, nrn);
 508                 state_changed = 1;
 509         }
 510
 511         if (state_changed || force) {
 512                 if (IS_ZEBRA_DEBUG_NHT)
 513                         zlog_debug("%s(%u):%pRN: Route import check %s %s",
 514                                    VRF_LOGNAME(zvrf->vrf), zvrf->vrf->vrf_id,
 515                                    nrn, rnh->state ? "passed" : "failed",
 516                                    state_changed ? "(state changed)" : "");
 517                 /* state changed, notify clients */
 518                 for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client)) {
 519                         zebra_send_rnh_update(rnh, client,
 520                                               RNH_IMPORT_CHECK_TYPE,
 521                                               zvrf->vrf->vrf_id, 0);
 522                 }
 523         }
 524 }
 525
 526 /*
 527  * Notify clients registered for this nexthop about a change.
 528  */
 529 static void zebra_rnh_notify_protocol_clients(struct zebra_vrf *zvrf, afi_t afi,
 530                                               struct route_node *nrn,
 531                                               struct rnh *rnh,
 532                                               struct route_node *prn,
 533                                               struct route_entry *re)
 534 {
 535         struct listnode *node;
 536         struct zserv *client;
 537         int num_resolving_nh;
 538
 539         if (IS_ZEBRA_DEBUG_NHT) {
 540                 if (prn && re) {
 541                         zlog_debug("%s(%u):%pRN: NH resolved over route %pRN",
 542                                    VRF_LOGNAME(zvrf->vrf), zvrf->vrf->vrf_id,
 543                                    nrn, prn);
 544                 } else
 545                         zlog_debug("%s(%u):%pRN: NH has become unresolved",
 546                                    VRF_LOGNAME(zvrf->vrf), zvrf->vrf->vrf_id,
 547                                    nrn);
 548         }
 549
 550         for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client)) {
 551                 if (prn && re) {
 552                         /* Apply route-map for this client to route resolving
 553                          * this
 554                          * nexthop to see if it is filtered or not.
 555                          */
 556                         zebra_rnh_clear_nexthop_rnh_filters(re);
 557                         num_resolving_nh = zebra_rnh_apply_nht_rmap(
 558                                 afi, zvrf, prn, re, client->proto);
 559                         if (num_resolving_nh)
 560                                 rnh->filtered[client->proto] = 0;
 561                         else
 562                                 rnh->filtered[client->proto] = 1;
 563
 564                         if (IS_ZEBRA_DEBUG_NHT)
 565                                 zlog_debug(
 566                                         "%s(%u):%pRN: Notifying client %s about NH %s",
 567                                         VRF_LOGNAME(zvrf->vrf),
 568                                         zvrf->vrf->vrf_id, nrn,
 569                                         zebra_route_string(client->proto),
 570                                         num_resolving_nh
 571                                                 ? ""
 572                                                 : "(filtered by route-map)");
 573                 } else {
 574                         rnh->filtered[client->proto] = 0;
 575                         if (IS_ZEBRA_DEBUG_NHT)
 576                                 zlog_debug(
 577                                         "%s(%u):%pRN: Notifying client %s about NH (unreachable)",
 578                                         VRF_LOGNAME(zvrf->vrf),
 579                                         zvrf->vrf->vrf_id, nrn,
 580                                         zebra_route_string(client->proto));
 581                 }
 582
 583                 zebra_send_rnh_update(rnh, client, RNH_NEXTHOP_TYPE,
 584                                       zvrf->vrf->vrf_id, 0);
 585         }
 586
 587         if (re)
 588                 zebra_rnh_clear_nexthop_rnh_filters(re);
 589 }
 590
 591 /*
 592  * Utility to determine whether a candidate nexthop is useable. We make this
 593  * check in a couple of places, so this is a single home for the logic we
 594  * use.
 595  */
 596
 597 static const int RNH_INVALID_NH_FLAGS = (NEXTHOP_FLAG_RECURSIVE |
 598                                          NEXTHOP_FLAG_DUPLICATE |
 599                                          NEXTHOP_FLAG_RNH_FILTERED);
 600
 601 bool rnh_nexthop_valid(const struct route_entry *re, const struct nexthop *nh)
 602 {
 603         return (CHECK_FLAG(re->status, ROUTE_ENTRY_INSTALLED)
 604                 && CHECK_FLAG(nh->flags, NEXTHOP_FLAG_ACTIVE)
 605                 && !CHECK_FLAG(nh->flags, RNH_INVALID_NH_FLAGS));
 606 }
 607
 608 /*
 609  * Determine whether an re's nexthops are valid for tracking.
 610  */
 611 static bool rnh_check_re_nexthops(const struct route_entry *re,
 612                                   const struct rnh *rnh)
 613 {
 614         bool ret = false;
 615         const struct nexthop *nexthop = NULL;
 616
 617         /* Check route's nexthops */
 618         for (ALL_NEXTHOPS(re->nhe->nhg, nexthop)) {
 619                 if (rnh_nexthop_valid(re, nexthop))
 620                         break;
 621         }
 622
 623         /* Check backup nexthops, if any. */
 624         if (nexthop == NULL && re->nhe->backup_info &&
 625             re->nhe->backup_info->nhe) {
 626                 for (ALL_NEXTHOPS(re->nhe->backup_info->nhe->nhg, nexthop)) {
 627                         if (rnh_nexthop_valid(re, nexthop))
 628                                 break;
 629                 }
 630         }
 631
 632         if (nexthop == NULL) {
 633                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 634                         zlog_debug(
 635                                 "        Route Entry %s no nexthops",
 636                                 zebra_route_string(re->type));
 637
 638                 goto done;
 639         }
 640
 641         /* Some special checks if registration asked for them. */
 642         if (CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED)) {
 643                 if ((re->type == ZEBRA_ROUTE_CONNECT)
 644                     || (re->type == ZEBRA_ROUTE_STATIC))
 645                         ret = true;
 646                 if (re->type == ZEBRA_ROUTE_NHRP) {
 647
 648                         for (nexthop = re->nhe->nhg.nexthop;
 649                              nexthop;
 650                              nexthop = nexthop->next)
 651                                 if (nexthop->type == NEXTHOP_TYPE_IFINDEX)
 652                                         break;
 653                         if (nexthop)
 654                                 ret = true;
 655                 }
 656         } else {
 657                 ret = true;
 658         }
 659
 660 done:
 661         return ret;
 662 }
 663
 664 /*
 665  * Determine appropriate route (route entry) resolving a tracked
 666  * nexthop.
 667  */
 668 static struct route_entry *
 669 zebra_rnh_resolve_nexthop_entry(struct zebra_vrf *zvrf, afi_t afi,
 670                                 struct route_node *nrn, const struct rnh *rnh,
 671                                 struct route_node **prn)
 672 {
 673         struct route_table *route_table;
 674         struct route_node *rn;
 675         struct route_entry *re;
 676
 677         *prn = NULL;
 678
 679         route_table = zvrf->table[afi][SAFI_UNICAST];
 680         if (!route_table)
 681                 return NULL;
 682
 683         rn = route_node_match(route_table, &nrn->p);
 684         if (!rn)
 685                 return NULL;
 686
 687         /* Unlock route node - we don't need to lock when walking the tree. */
 688         route_unlock_node(rn);
 689
 690         /* While resolving nexthops, we may need to walk up the tree from the
 691          * most-specific match. Do similar logic as in zebra_rib.c
 692          */
 693         while (rn) {
 694                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 695                         zlog_debug("%s: %s(%u):%pRN Possible Match to %pRN",
 696                                    __func__, VRF_LOGNAME(zvrf->vrf),
 697                                    rnh->vrf_id, rnh->node, rn);
 698
 699                 /* Do not resolve over default route unless allowed &&
 700                  * match route to be exact if so specified
 701                  */
 702                 if (is_default_prefix(&rn->p)
 703                     && !rnh_resolve_via_default(zvrf, rn->p.family)) {
 704                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 705                                 zlog_debug(
 706                                         "        Not allowed to resolve through default prefix");
 707                         return NULL;
 708                 }
 709
 710                 /* Identify appropriate route entry. */
 711                 RNODE_FOREACH_RE (rn, re) {
 712                         if (CHECK_FLAG(re->status, ROUTE_ENTRY_REMOVED)) {
 713                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 714                                         zlog_debug(
 715                                                 "        Route Entry %s removed",
 716                                                 zebra_route_string(re->type));
 717                                 continue;
 718                         }
 719                         if (!CHECK_FLAG(re->flags, ZEBRA_FLAG_SELECTED) &&
 720                             !CHECK_FLAG(re->flags, ZEBRA_FLAG_FIB_OVERRIDE)) {
 721                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 722                                         zlog_debug(
 723                                                 "        Route Entry %s !selected",
 724                                                 zebra_route_string(re->type));
 725                                 continue;
 726                         }
 727
 728                         if (CHECK_FLAG(re->status, ROUTE_ENTRY_QUEUED)) {
 729                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 730                                         zlog_debug(
 731                                                 "        Route Entry %s queued",
 732                                                 zebra_route_string(re->type));
 733                                 continue;
 734                         }
 735
 736                         /* Just being SELECTED isn't quite enough - must
 737                          * have an installed nexthop to be useful.
 738                          */
 739                         if (rnh_check_re_nexthops(re, rnh))
 740                                 break;
 741                 }
 742
 743                 /* Route entry found, we're done; else, walk up the tree. */
 744                 if (re) {
 745                         *prn = rn;
 746                         return re;
 747                 }
 748
 749                 if (!CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED))
 750                         rn = rn->parent;
 751                 else {
 752                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
 753                                 zlog_debug(
 754                                         "        Nexthop must be connected, cannot recurse up");
 755                         return NULL;
 756                 }
 757         }
 758
 759         return NULL;
 760 }
 761
 762 static void zebra_rnh_process_pseudowires(vrf_id_t vrfid, struct rnh *rnh)
 763 {
 764         struct zebra_pw *pw;
 765         struct listnode *node;
 766
 767         for (ALL_LIST_ELEMENTS_RO(rnh->zebra_pseudowire_list, node, pw))
 768                 zebra_pw_update(pw);
 769 }
 770
 771 /*
 772  * See if a tracked nexthop entry has undergone any change, and if so,
 773  * take appropriate action; this involves notifying any clients and/or
 774  * scheduling dependent static routes for processing.
 775  */
 776 static void zebra_rnh_eval_nexthop_entry(struct zebra_vrf *zvrf, afi_t afi,
 777                                          int force, struct route_node *nrn,
 778                                          struct rnh *rnh,
 779                                          struct route_node *prn,
 780                                          struct route_entry *re)
 781 {
 782         int state_changed = 0;
 783
 784         /* If we're resolving over a different route, resolution has changed or
 785          * the resolving route has some change (e.g., metric), there is a state
 786          * change.
 787          */
 788         zebra_rnh_remove_from_routing_table(rnh);
 789         if (!prefix_same(&rnh->resolved_route, prn ? &prn->p : NULL)) {
 790                 if (prn)
 791                         prefix_copy(&rnh->resolved_route, &prn->p);
 792                 else {
 793                         /*
 794                          * Just quickly store the family of the resolved
 795                          * route so that we can reset it in a second here
 796                          */
 797                         int family = rnh->resolved_route.family;
 798
 799                         memset(&rnh->resolved_route, 0, sizeof(struct prefix));
 800                         rnh->resolved_route.family = family;
 801                 }
 802
 803                 copy_state(rnh, re, nrn);
 804                 state_changed = 1;
 805         } else if (compare_state(re, rnh->state)) {
 806                 copy_state(rnh, re, nrn);
 807                 state_changed = 1;
 808         }
 809         zebra_rnh_store_in_routing_table(rnh);
 810
 811         if (state_changed || force) {
 812                 /* NOTE: Use the "copy" of resolving route stored in 'rnh' i.e.,
 813                  * rnh->state.
 814                  */
 815                 /* Notify registered protocol clients. */
 816                 zebra_rnh_notify_protocol_clients(zvrf, afi, nrn, rnh, prn,
 817                                                   rnh->state);
 818
 819                 /* Process pseudowires attached to this nexthop */
 820                 zebra_rnh_process_pseudowires(zvrf->vrf->vrf_id, rnh);
 821         }
 822 }
 823
 824 /* Evaluate one tracked entry */
 825 static void zebra_rnh_evaluate_entry(struct zebra_vrf *zvrf, afi_t afi,
 826                                      int force, enum rnh_type type,
 827                                      struct route_node *nrn)
 828 {
 829         struct rnh *rnh;
 830         struct route_entry *re;
 831         struct route_node *prn;
 832
 833         if (IS_ZEBRA_DEBUG_NHT) {
 834                 zlog_debug("%s(%u):%pRN: Evaluate RNH, type %s %s",
 835                            VRF_LOGNAME(zvrf->vrf), zvrf->vrf->vrf_id, nrn,
 836                            rnh_type2str(type), force ? "(force)" : "");
 837         }
 838
 839         rnh = nrn->info;
 840
 841         /* Identify route entry (RE) resolving this tracked entry. */
 842         if (type == RNH_IMPORT_CHECK_TYPE)
 843                 re = zebra_rnh_resolve_import_entry(zvrf, afi, nrn, rnh, &prn);
 844         else
 845                 re = zebra_rnh_resolve_nexthop_entry(zvrf, afi, nrn, rnh, &prn);
 846
 847         /* If the entry cannot be resolved and that is also the existing state,
 848          * there is nothing further to do.
 849          */
 850         if (!re && rnh->state == NULL && !force)
 851                 return;
 852
 853         /* Process based on type of entry. */
 854         if (type == RNH_IMPORT_CHECK_TYPE)
 855                 zebra_rnh_eval_import_check_entry(zvrf, afi, force, nrn, rnh,
 856                                                   prn, re);
 857         else
 858                 zebra_rnh_eval_nexthop_entry(zvrf, afi, force, nrn, rnh, prn,
 859                                              re);
 860 }
 861
 862 /*
 863  * Clear the ROUTE_ENTRY_NEXTHOPS_CHANGED flag
 864  * from the re entries.
 865  *
 866  * Please note we are doing this *after* we have
 867  * notified the world about each nexthop as that
 868  * we can have a situation where one re entry
 869  * covers multiple nexthops we are interested in.
 870  */
 871 static void zebra_rnh_clear_nhc_flag(struct zebra_vrf *zvrf, afi_t afi,
 872                                      enum rnh_type type, struct route_node *nrn)
 873 {
 874         struct rnh *rnh;
 875         struct route_entry *re;
 876         struct route_node *prn;
 877
 878         rnh = nrn->info;
 879
 880         /* Identify route entry (RIB) resolving this tracked entry. */
 881         if (type == RNH_IMPORT_CHECK_TYPE)
 882                 re = zebra_rnh_resolve_import_entry(zvrf, afi, nrn, rnh,
 883                                                     &prn);
 884         else
 885                 re = zebra_rnh_resolve_nexthop_entry(zvrf, afi, nrn, rnh,
 886                                                      &prn);
 887
 888         if (re)
 889                 UNSET_FLAG(re->status, ROUTE_ENTRY_LABELS_CHANGED);
 890 }
 891
 892 /* Evaluate all tracked entries (nexthops or routes for import into BGP)
 893  * of a particular VRF and address-family or a specific prefix.
 894  */
 895 void zebra_evaluate_rnh(struct zebra_vrf *zvrf, afi_t afi, int force,
 896                         enum rnh_type type, struct prefix *p)
 897 {
 898         struct route_table *rnh_table;
 899         struct route_node *nrn;
 900
 901         rnh_table = get_rnh_table(zvrf->vrf->vrf_id, afi, type);
 902         if (!rnh_table) // unexpected
 903                 return;
 904
 905         if (p) {
 906                 /* Evaluating a specific entry, make sure it exists. */
 907                 nrn = route_node_lookup(rnh_table, p);
 908                 if (nrn && nrn->info)
 909                         zebra_rnh_evaluate_entry(zvrf, afi, force, type, nrn);
 910
 911                 if (nrn)
 912                         route_unlock_node(nrn);
 913         } else {
 914                 /* Evaluate entire table. */
 915                 nrn = route_top(rnh_table);
 916                 while (nrn) {
 917                         if (nrn->info)
 918                                 zebra_rnh_evaluate_entry(zvrf, afi, force, type,
 919                                                          nrn);
 920                         nrn = route_next(nrn); /* this will also unlock nrn */
 921                 }
 922                 nrn = route_top(rnh_table);
 923                 while (nrn) {
 924                         if (nrn->info)
 925                                 zebra_rnh_clear_nhc_flag(zvrf, afi, type, nrn);
 926                         nrn = route_next(nrn); /* this will also unlock nrn */
 927                 }
 928         }
 929 }
 930
 931 void zebra_print_rnh_table(vrf_id_t vrfid, afi_t afi, struct vty *vty,
 932                            enum rnh_type type, struct prefix *p)
 933 {
 934         struct route_table *table;
 935         struct route_node *rn;
 936
 937         table = get_rnh_table(vrfid, afi, type);
 938         if (!table) {
 939                 if (IS_ZEBRA_DEBUG_NHT)
 940                         zlog_debug("print_rnhs: rnh table not found");
 941                 return;
 942         }
 943
 944         for (rn = route_top(table); rn; rn = route_next(rn)) {
 945                 if (p && !prefix_match(&rn->p, p))
 946                         continue;
 947
 948                 if (rn->info)
 949                         print_rnh(rn, vty);
 950         }
 951 }
 952
 953 /**
 954  * free_state - free up the re structure associated with the rnh.
 955  */
 956 static void free_state(vrf_id_t vrf_id, struct route_entry *re,
 957                        struct route_node *rn)
 958 {
 959         if (!re)
 960                 return;
 961
 962         /* free RE and nexthops */
 963         zebra_nhg_free(re->nhe);
 964         XFREE(MTYPE_RE, re);
 965 }
 966
 967 static void copy_state(struct rnh *rnh, const struct route_entry *re,
 968                        struct route_node *rn)
 969 {
 970         struct route_entry *state;
 971
 972         if (rnh->state) {
 973                 free_state(rnh->vrf_id, rnh->state, rn);
 974                 rnh->state = NULL;
 975         }
 976
 977         if (!re)
 978                 return;
 979
 980         state = XCALLOC(MTYPE_RE, sizeof(struct route_entry));
 981         state->type = re->type;
 982         state->distance = re->distance;
 983         state->metric = re->metric;
 984         state->vrf_id = re->vrf_id;
 985         state->status = re->status;
 986
 987         state->nhe = zebra_nhe_copy(re->nhe, 0);
 988
 989         /* Copy the 'fib' nexthops also, if present - we want to capture
 990          * the true installed nexthops.
 991          */
 992         if (re->fib_ng.nexthop)
 993                 nexthop_group_copy(&state->fib_ng, &re->fib_ng);
 994         if (re->fib_backup_ng.nexthop)
 995                 nexthop_group_copy(&state->fib_backup_ng, &re->fib_backup_ng);
 996
 997         rnh->state = state;
 998 }
 999
1000 /*
1001  * Locate the next primary nexthop, used when comparing current rnh info with
1002  * an updated route.
1003  */
1004 static struct nexthop *next_valid_primary_nh(struct route_entry *re,
1005                                              struct nexthop *nh)
1006 {
1007         struct nexthop_group *nhg;
1008         struct nexthop *bnh;
1009         int i, idx;
1010         bool default_path = true;
1011
1012         /* Fib backup ng present: some backups are installed,
1013          * and we're configured for special handling if there are backups.
1014          */
1015         if (rnh_hide_backups && (re->fib_backup_ng.nexthop != NULL))
1016                 default_path = false;
1017
1018         /* Default path: no special handling, just using the 'installed'
1019          * primary nexthops and the common validity test.
1020          */
1021         if (default_path) {
1022                 if (nh == NULL) {
1023                         nhg = rib_get_fib_nhg(re);
1024                         nh = nhg->nexthop;
1025                 } else
1026                         nh = nexthop_next(nh);
1027
1028                 while (nh) {
1029                         if (rnh_nexthop_valid(re, nh))
1030                                 break;
1031                         else
1032                                 nh = nexthop_next(nh);
1033                 }
1034
1035                 return nh;
1036         }
1037
1038         /* Hide backup activation/switchover events.
1039          *
1040          * If we've had a switchover, an inactive primary won't be in
1041          * the fib list at all - the 'fib' list could even be empty
1042          * in the case where no primary is installed. But we want to consider
1043          * those primaries "valid" if they have an activated backup nh.
1044          *
1045          * The logic is something like:
1046          * if (!fib_nhg)
1047          *     // then all primaries are installed
1048          * else
1049          *     for each primary in re nhg
1050          *         if in fib_nhg
1051          *             primary is installed
1052          *         else if a backup is installed
1053          *             primary counts as installed
1054          *         else
1055          *             primary !installed
1056          */
1057
1058         /* Start with the first primary */
1059         if (nh == NULL)
1060                 nh = re->nhe->nhg.nexthop;
1061         else
1062                 nh = nexthop_next(nh);
1063
1064         while (nh) {
1065
1066                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1067                         zlog_debug("%s: checking primary NH %pNHv",
1068                                    __func__, nh);
1069
1070                 /* If this nexthop is in the fib list, it's installed */
1071                 nhg = rib_get_fib_nhg(re);
1072
1073                 for (bnh = nhg->nexthop; bnh; bnh = nexthop_next(bnh)) {
1074                         if (nexthop_cmp(nh, bnh) == 0)
1075                                 break;
1076                 }
1077
1078                 if (bnh != NULL) {
1079                         /* Found the match */
1080                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1081                                 zlog_debug("%s:     NH in fib list", __func__);
1082                         break;
1083                 }
1084
1085                 /* Else if this nexthop's backup is installed, it counts */
1086                 nhg = rib_get_fib_backup_nhg(re);
1087                 bnh = nhg->nexthop;
1088
1089                 for (idx = 0; bnh != NULL; idx++) {
1090                         /* If we find an active backup nh for this
1091                          * primary, we're done;
1092                          */
1093                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1094                                 zlog_debug("%s: checking backup %pNHv [%d]",
1095                                            __func__, bnh, idx);
1096
1097                         if (!CHECK_FLAG(bnh->flags, NEXTHOP_FLAG_ACTIVE))
1098                                 continue;
1099
1100                         for (i = 0; i < nh->backup_num; i++) {
1101                                 /* Found a matching activated backup nh */
1102                                 if (nh->backup_idx[i] == idx) {
1103                                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1104                                                 zlog_debug("%s: backup %d activated",
1105                                                            __func__, i);
1106
1107                                         goto done;
1108                                 }
1109                         }
1110
1111                         /* Note that we're not recursing here if the
1112                          * backups are recursive: the primary's index is
1113                          * only valid in the top-level backup list.
1114                          */
1115                         bnh = bnh->next;
1116                 }
1117
1118                 /* Try the next primary nexthop */
1119                 nh = nexthop_next(nh);
1120         }
1121
1122 done:
1123
1124         return nh;
1125 }
1126
1127 /*
1128  * Compare two route_entries' nexthops. Account for backup nexthops
1129  * and for the 'fib' nexthop lists, if present.
1130  */
1131 static bool compare_valid_nexthops(struct route_entry *r1,
1132                                    struct route_entry *r2)
1133 {
1134         bool matched_p = false;
1135         struct nexthop_group *nhg1, *nhg2;
1136         struct nexthop *nh1, *nh2;
1137
1138         /* Start with the primary nexthops */
1139
1140         nh1 = next_valid_primary_nh(r1, NULL);
1141         nh2 = next_valid_primary_nh(r2, NULL);
1142
1143         while (1) {
1144                 /* Find any differences in the nexthop lists */
1145
1146                 if (nh1 && nh2) {
1147                         /* Any difference is a no-match */
1148                         if (nexthop_cmp(nh1, nh2) != 0) {
1149                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1150                                         zlog_debug("%s: nh1: %pNHv, nh2: %pNHv differ",
1151                                                    __func__, nh1, nh2);
1152                                 goto done;
1153                         }
1154
1155                 } else if (nh1 || nh2) {
1156                         /* One list has more valid nexthops than the other */
1157                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1158                                 zlog_debug("%s: nh1 %s, nh2 %s", __func__,
1159                                            nh1 ? "non-NULL" : "NULL",
1160                                            nh2 ? "non-NULL" : "NULL");
1161                         goto done;
1162                 } else
1163                         break; /* Done with both lists */
1164
1165                 nh1 = next_valid_primary_nh(r1, nh1);
1166                 nh2 = next_valid_primary_nh(r2, nh2);
1167         }
1168
1169         /* If configured, don't compare installed backup state - we've
1170          * accounted for that with the primaries above.
1171          *
1172          * But we do want to compare the routes' backup info,
1173          * in case the owning route has changed the backups -
1174          * that change we do want to report.
1175          */
1176         if (rnh_hide_backups) {
1177                 uint32_t hash1 = 0, hash2 = 0;
1178
1179                 if (r1->nhe->backup_info)
1180                         hash1 = nexthop_group_hash(
1181                                 &r1->nhe->backup_info->nhe->nhg);
1182
1183                 if (r2->nhe->backup_info)
1184                         hash2 = nexthop_group_hash(
1185                                 &r2->nhe->backup_info->nhe->nhg);
1186
1187                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1188                         zlog_debug("%s: backup hash1 %#x, hash2 %#x",
1189                                    __func__, hash1, hash2);
1190
1191                 if (hash1 != hash2)
1192                         goto done;
1193                 else
1194                         goto finished;
1195         }
1196
1197         /* The test for the backups is slightly different: the only installed
1198          * backups will be in the 'fib' list.
1199          */
1200         nhg1 = rib_get_fib_backup_nhg(r1);
1201         nhg2 = rib_get_fib_backup_nhg(r2);
1202
1203         nh1 = nhg1->nexthop;
1204         nh2 = nhg2->nexthop;
1205
1206         while (1) {
1207                 /* Find each backup list's next valid nexthop */
1208                 while ((nh1 != NULL) && !rnh_nexthop_valid(r1, nh1))
1209                         nh1 = nexthop_next(nh1);
1210
1211                 while ((nh2 != NULL) && !rnh_nexthop_valid(r2, nh2))
1212                         nh2 = nexthop_next(nh2);
1213
1214                 if (nh1 && nh2) {
1215                         /* Any difference is a no-match */
1216                         if (nexthop_cmp(nh1, nh2) != 0) {
1217                                 if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1218                                         zlog_debug("%s: backup nh1: %pNHv, nh2: %pNHv differ",
1219                                                    __func__, nh1, nh2);
1220                                 goto done;
1221                         }
1222
1223                         nh1 = nexthop_next(nh1);
1224                         nh2 = nexthop_next(nh2);
1225                 } else if (nh1 || nh2) {
1226                         /* One list has more valid nexthops than the other */
1227                         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1228                                 zlog_debug("%s: backup nh1 %s, nh2 %s",
1229                                            __func__,
1230                                            nh1 ? "non-NULL" : "NULL",
1231                                            nh2 ? "non-NULL" : "NULL");
1232                         goto done;
1233                 } else
1234                         break; /* Done with both lists */
1235         }
1236
1237 finished:
1238
1239         /* Well, it's a match */
1240         matched_p = true;
1241
1242 done:
1243
1244         if (IS_ZEBRA_DEBUG_NHT_DETAILED)
1245                 zlog_debug("%s: %smatched",
1246                            __func__, (matched_p ? "" : "NOT "));
1247
1248         return matched_p;
1249 }
1250
1251 /* Returns 'false' if no difference. */
1252 static bool compare_state(struct route_entry *r1,
1253                           struct route_entry *r2)
1254 {
1255         if (!r1 && !r2)
1256                 return false;
1257
1258         if ((!r1 && r2) || (r1 && !r2))
1259                 return true;
1260
1261         if (r1->distance != r2->distance)
1262                 return true;
1263
1264         if (r1->metric != r2->metric)
1265                 return true;
1266
1267         if (!compare_valid_nexthops(r1, r2))
1268                 return true;
1269
1270         return false;
1271 }
1272
1273 int zebra_send_rnh_update(struct rnh *rnh, struct zserv *client,
1274                           enum rnh_type type, vrf_id_t vrf_id,
1275                           uint32_t srte_color)
1276 {
1277         struct stream *s = NULL;
1278         struct route_entry *re;
1279         unsigned long nump;
1280         uint8_t num;
1281         struct nexthop *nh;
1282         struct route_node *rn;
1283         int ret;
1284         uint32_t message = 0;
1285         int cmd = (type == RNH_IMPORT_CHECK_TYPE) ? ZEBRA_IMPORT_CHECK_UPDATE
1286                                                   : ZEBRA_NEXTHOP_UPDATE;
1287
1288         rn = rnh->node;
1289         re = rnh->state;
1290
1291         /* Get output stream. */
1292         s = stream_new(ZEBRA_MAX_PACKET_SIZ);
1293
1294         zclient_create_header(s, cmd, vrf_id);
1295
1296         /* Message flags. */
1297         if (srte_color)
1298                 SET_FLAG(message, ZAPI_MESSAGE_SRTE);
1299         stream_putl(s, message);
1300
1301         stream_putw(s, rn->p.family);
1302         switch (rn->p.family) {
1303         case AF_INET:
1304                 stream_putc(s, rn->p.prefixlen);
1305                 stream_put_in_addr(s, &rn->p.u.prefix4);
1306                 break;
1307         case AF_INET6:
1308                 stream_putc(s, rn->p.prefixlen);
1309                 stream_put(s, &rn->p.u.prefix6, IPV6_MAX_BYTELEN);
1310                 break;
1311         default:
1312                 flog_err(EC_ZEBRA_RNH_UNKNOWN_FAMILY,
1313                          "%s: Unknown family (%d) notification attempted",
1314                          __func__, rn->p.family);
1315                 goto failure;
1316         }
1317         if (srte_color)
1318                 stream_putl(s, srte_color);
1319
1320         if (re) {
1321                 struct zapi_nexthop znh;
1322                 struct nexthop_group *nhg;
1323
1324                 stream_putc(s, re->type);
1325                 stream_putw(s, re->instance);
1326                 stream_putc(s, re->distance);
1327                 stream_putl(s, re->metric);
1328                 num = 0;
1329                 nump = stream_get_endp(s);
1330                 stream_putc(s, 0);
1331
1332                 nhg = rib_get_fib_nhg(re);
1333                 for (ALL_NEXTHOPS_PTR(nhg, nh))
1334                         if (rnh_nexthop_valid(re, nh)) {
1335                                 zapi_nexthop_from_nexthop(&znh, nh);
1336                                 ret = zapi_nexthop_encode(s, &znh, 0, message);
1337                                 if (ret < 0)
1338                                         goto failure;
1339
1340                                 num++;
1341                         }
1342
1343                 nhg = rib_get_fib_backup_nhg(re);
1344                 if (nhg) {
1345                         for (ALL_NEXTHOPS_PTR(nhg, nh))
1346                                 if (rnh_nexthop_valid(re, nh)) {
1347                                         zapi_nexthop_from_nexthop(&znh, nh);
1348                                         ret = zapi_nexthop_encode(
1349                                                 s, &znh, 0 /* flags */,
1350                                                 0 /* message */);
1351                                         if (ret < 0)
1352                                                 goto failure;
1353
1354                                         num++;
1355                                 }
1356                 }
1357
1358                 stream_putc_at(s, nump, num);
1359         } else {
1360                 stream_putc(s, 0); // type
1361                 stream_putw(s, 0); // instance
1362                 stream_putc(s, 0); // distance
1363                 stream_putl(s, 0); // metric
1364                 stream_putc(s, 0); // nexthops
1365         }
1366         stream_putw_at(s, 0, stream_get_endp(s));
1367
1368         client->nh_last_upd_time = monotime(NULL);
1369         return zserv_send_message(client, s);
1370
1371 failure:
1372
1373         stream_free(s);
1374         return -1;
1375 }
1376
1377 static void print_nh(struct nexthop *nexthop, struct vty *vty)
1378 {
1379         char buf[BUFSIZ];
1380         struct zebra_ns *zns = zebra_ns_lookup(nexthop->vrf_id);
1381
1382         switch (nexthop->type) {
1383         case NEXTHOP_TYPE_IPV4:
1384         case NEXTHOP_TYPE_IPV4_IFINDEX:
1385                 vty_out(vty, " via %pI4", &nexthop->gate.ipv4);
1386                 if (nexthop->ifindex)
1387                         vty_out(vty, ", %s",
1388                                 ifindex2ifname_per_ns(zns, nexthop->ifindex));
1389                 break;
1390         case NEXTHOP_TYPE_IPV6:
1391         case NEXTHOP_TYPE_IPV6_IFINDEX:
1392                 vty_out(vty, " %s",
1393                         inet_ntop(AF_INET6, &nexthop->gate.ipv6, buf, BUFSIZ));
1394                 if (nexthop->ifindex)
1395                         vty_out(vty, ", via %s",
1396                                 ifindex2ifname_per_ns(zns, nexthop->ifindex));
1397                 break;
1398         case NEXTHOP_TYPE_IFINDEX:
1399                 vty_out(vty, " is directly connected, %s",
1400                         ifindex2ifname_per_ns(zns, nexthop->ifindex));
1401                 break;
1402         case NEXTHOP_TYPE_BLACKHOLE:
1403                 vty_out(vty, " is directly connected, Null0");
1404                 break;
1405         default:
1406                 break;
1407         }
1408         vty_out(vty, "\n");
1409 }
1410
1411 static void print_rnh(struct route_node *rn, struct vty *vty)
1412 {
1413         struct rnh *rnh;
1414         struct nexthop *nexthop;
1415         struct listnode *node;
1416         struct zserv *client;
1417         char buf[BUFSIZ];
1418
1419         rnh = rn->info;
1420         vty_out(vty, "%s%s\n",
1421                 inet_ntop(rn->p.family, &rn->p.u.prefix, buf, BUFSIZ),
1422                 CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED) ? "(Connected)"
1423                                                             : "");
1424         if (rnh->state) {
1425                 vty_out(vty, " resolved via %s\n",
1426                         zebra_route_string(rnh->state->type));
1427                 for (nexthop = rnh->state->nhe->nhg.nexthop; nexthop;
1428                      nexthop = nexthop->next)
1429                         print_nh(nexthop, vty);
1430         } else
1431                 vty_out(vty, " unresolved%s\n",
1432                         CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED)
1433                                 ? "(Connected)"
1434                                 : "");
1435
1436         vty_out(vty, " Client list:");
1437         for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client))
1438                 vty_out(vty, " %s(fd %d)%s", zebra_route_string(client->proto),
1439                         client->sock,
1440                         rnh->filtered[client->proto] ? "(filtered)" : "");
1441         if (!list_isempty(rnh->zebra_pseudowire_list))
1442                 vty_out(vty, " zebra[pseudowires]");
1443         vty_out(vty, "\n");
1444 }
1445
1446 static int zebra_cleanup_rnh_client(vrf_id_t vrf_id, afi_t afi,
1447                                     struct zserv *client, enum rnh_type type)
1448 {
1449         struct route_table *ntable;
1450         struct route_node *nrn;
1451         struct rnh *rnh;
1452
1453         if (IS_ZEBRA_DEBUG_NHT) {
1454                 struct vrf *vrf = vrf_lookup_by_id(vrf_id);
1455
1456                 zlog_debug(
1457                         "%s(%u): Client %s RNH cleanup for family %s type %s",
1458                         VRF_LOGNAME(vrf), vrf_id,
1459                         zebra_route_string(client->proto), afi2str(afi),
1460                         rnh_type2str(type));
1461         }
1462
1463         ntable = get_rnh_table(vrf_id, afi, type);
1464         if (!ntable) {
1465                 zlog_debug("cleanup_rnh_client: rnh table not found");
1466                 return -1;
1467         }
1468
1469         for (nrn = route_top(ntable); nrn; nrn = route_next(nrn)) {
1470                 if (!nrn->info)
1471                         continue;
1472
1473                 rnh = nrn->info;
1474                 zebra_remove_rnh_client(rnh, client, type);
1475         }
1476         return 1;
1477 }
1478
1479 /* Cleanup registered nexthops (across VRFs) upon client disconnect. */
1480 static int zebra_client_cleanup_rnh(struct zserv *client)
1481 {
1482         struct vrf *vrf;
1483         struct zebra_vrf *zvrf;
1484
1485         RB_FOREACH (vrf, vrf_id_head, &vrfs_by_id) {
1486                 zvrf = vrf->info;
1487                 if (zvrf) {
1488                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP, client,
1489                                                  RNH_NEXTHOP_TYPE);
1490                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP6, client,
1491                                                  RNH_NEXTHOP_TYPE);
1492                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP, client,
1493                                                  RNH_IMPORT_CHECK_TYPE);
1494                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AFI_IP6, client,
1495                                                  RNH_IMPORT_CHECK_TYPE);
1496                 }
1497         }
1498
1499         return 0;
1500 }
1501
1502 int rnh_resolve_via_default(struct zebra_vrf *zvrf, int family)
1503 {
1504         if (((family == AF_INET) && zvrf->zebra_rnh_ip_default_route)
1505             || ((family == AF_INET6) && zvrf->zebra_rnh_ipv6_default_route))
1506                 return 1;
1507         else
1508                 return 0;
1509 }
1510
1511 /*
1512  * UI control to avoid notifications if backup nexthop status changes
1513  */
1514 void rnh_set_hide_backups(bool hide_p)
1515 {
1516         rnh_hide_backups = hide_p;
1517 }
1518
1519 bool rnh_get_hide_backups(void)
1520 {
1521         return rnh_hide_backups;
1522 }