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