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