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
 219         /*
 220          * We always need to respond with known information,
 221          * currently multiple daemons expect this behavior
 222          */
 223         send_client(rnh, client, type, vrf_id);
 224 }
 225
 226 void zebra_remove_rnh_client(struct rnh *rnh, struct zserv *client,
 227                              rnh_type_t type)
 228 {
 229         if (IS_ZEBRA_DEBUG_NHT) {
 230                 char buf[PREFIX2STR_BUFFER];
 231                 zlog_debug("Client %s unregisters for RNH %s type %d",
 232                            zebra_route_string(client->proto),
 233                            rnh_str(rnh, buf, sizeof(buf)), type);
 234         }
 235         listnode_delete(rnh->client_list, client);
 236         if (list_isempty(rnh->client_list)
 237             && list_isempty(rnh->zebra_pseudowire_list))
 238                 zebra_delete_rnh(rnh, type);
 239 }
 240
 241 /* XXX move this utility function elsewhere? */
 242 static void addr2hostprefix(int af, const union g_addr *addr,
 243                             struct prefix *prefix)
 244 {
 245         switch (af) {
 246         case AF_INET:
 247                 prefix->family = AF_INET;
 248                 prefix->prefixlen = IPV4_MAX_BITLEN;
 249                 prefix->u.prefix4 = addr->ipv4;
 250                 break;
 251         case AF_INET6:
 252                 prefix->family = AF_INET6;
 253                 prefix->prefixlen = IPV6_MAX_BITLEN;
 254                 prefix->u.prefix6 = addr->ipv6;
 255                 break;
 256         default:
 257                 memset(prefix, 0, sizeof(*prefix));
 258                 zlog_debug("%s: unknown address family %d", __func__, af);
 259                 break;
 260         }
 261 }
 262
 263 void zebra_register_rnh_pseudowire(vrf_id_t vrf_id, struct zebra_pw *pw)
 264 {
 265         struct prefix nh;
 266         struct rnh *rnh;
 267         bool exists;
 268         struct zebra_vrf *zvrf;
 269
 270         zvrf = vrf_info_lookup(vrf_id);
 271         if (!zvrf)
 272                 return;
 273
 274         addr2hostprefix(pw->af, &pw->nexthop, &nh);
 275         rnh = zebra_add_rnh(&nh, vrf_id, RNH_NEXTHOP_TYPE, &exists);
 276         if (rnh && !listnode_lookup(rnh->zebra_pseudowire_list, pw)) {
 277                 listnode_add(rnh->zebra_pseudowire_list, pw);
 278                 pw->rnh = rnh;
 279                 zebra_evaluate_rnh(zvrf, pw->af, 1, RNH_NEXTHOP_TYPE, &nh);
 280         }
 281 }
 282
 283 void zebra_deregister_rnh_pseudowire(vrf_id_t vrf_id, struct zebra_pw *pw)
 284 {
 285         struct rnh *rnh;
 286
 287         rnh = pw->rnh;
 288         if (!rnh)
 289                 return;
 290
 291         listnode_delete(rnh->zebra_pseudowire_list, pw);
 292         pw->rnh = NULL;
 293
 294         if (list_isempty(rnh->client_list)
 295             && list_isempty(rnh->zebra_pseudowire_list))
 296                 zebra_delete_rnh(rnh, RNH_NEXTHOP_TYPE);
 297 }
 298
 299 /* Apply the NHT route-map for a client to the route (and nexthops)
 300  * resolving a NH.
 301  */
 302 static int zebra_rnh_apply_nht_rmap(int family, struct zebra_vrf *zvrf,
 303                                     struct route_node *prn,
 304                                     struct route_entry *re, int proto)
 305 {
 306         int at_least_one = 0;
 307         int rmap_family; /* Route map has diff AF family enum */
 308         struct nexthop *nexthop;
 309         int ret;
 310
 311         rmap_family = (family == AF_INET) ? AFI_IP : AFI_IP6;
 312
 313         if (prn && re) {
 314                 for (nexthop = re->ng.nexthop; nexthop;
 315                      nexthop = nexthop->next) {
 316                         ret = zebra_nht_route_map_check(
 317                                 rmap_family, proto, &prn->p, zvrf, re, nexthop);
 318                         if (ret != RMAP_DENYMATCH) {
 319                                 SET_FLAG(nexthop->flags, NEXTHOP_FLAG_ACTIVE);
 320                                 at_least_one++; /* at least one valid NH */
 321                         } else {
 322                                 UNSET_FLAG(nexthop->flags, NEXTHOP_FLAG_ACTIVE);
 323                         }
 324                 }
 325         }
 326         return (at_least_one);
 327 }
 328
 329 /*
 330  * Determine appropriate route (RE entry) resolving a tracked BGP route
 331  * for BGP route for import.
 332  */
 333 static struct route_entry *
 334 zebra_rnh_resolve_import_entry(struct zebra_vrf *zvrf, int family,
 335                                struct route_node *nrn, struct rnh *rnh,
 336                                struct route_node **prn)
 337 {
 338         struct route_table *route_table;
 339         struct route_node *rn;
 340         struct route_entry *re;
 341
 342         *prn = NULL;
 343
 344         route_table = zvrf->table[family2afi(family)][SAFI_UNICAST];
 345         if (!route_table) // unexpected
 346                 return NULL;
 347
 348         rn = route_node_match(route_table, &nrn->p);
 349         if (!rn)
 350                 return NULL;
 351
 352         /* Unlock route node - we don't need to lock when walking the tree. */
 353         route_unlock_node(rn);
 354
 355         if (CHECK_FLAG(rnh->flags, ZEBRA_NHT_EXACT_MATCH)
 356             && !prefix_same(&nrn->p, &rn->p))
 357                 return NULL;
 358
 359         /* Identify appropriate route entry. */
 360         RNODE_FOREACH_RE (rn, re) {
 361                 if (!CHECK_FLAG(re->status, ROUTE_ENTRY_REMOVED)
 362                     && CHECK_FLAG(re->flags, ZEBRA_FLAG_SELECTED)
 363                     && (re->type != ZEBRA_ROUTE_BGP))
 364                         break;
 365         }
 366
 367         if (re)
 368                 *prn = rn;
 369         return re;
 370 }
 371
 372 /*
 373  * See if a tracked route entry for import (by BGP) has undergone any
 374  * change, and if so, notify the client.
 375  */
 376 static void zebra_rnh_eval_import_check_entry(vrf_id_t vrfid, int family,
 377                                               int force, struct route_node *nrn,
 378                                               struct rnh *rnh,
 379                                               struct route_entry *re)
 380 {
 381         int state_changed = 0;
 382         struct zserv *client;
 383         char bufn[INET6_ADDRSTRLEN];
 384         struct listnode *node;
 385         struct nexthop *nexthop;
 386
 387         if (re && (rnh->state == NULL)) {
 388                 for (ALL_NEXTHOPS(re->ng, nexthop))
 389                         if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_FIB)) {
 390                                 state_changed = 1;
 391                                 break;
 392                         }
 393         } else if (!re && (rnh->state != NULL))
 394                 state_changed = 1;
 395
 396         if (compare_state(re, rnh->state))
 397                 copy_state(rnh, re, nrn);
 398
 399         if (state_changed || force) {
 400                 if (IS_ZEBRA_DEBUG_NHT) {
 401                         prefix2str(&nrn->p, bufn, INET6_ADDRSTRLEN);
 402                         zlog_debug("%u:%s: Route import check %s %s\n", vrfid,
 403                                    bufn, rnh->state ? "passed" : "failed",
 404                                    state_changed ? "(state changed)" : "");
 405                 }
 406                 /* state changed, notify clients */
 407                 for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client)) {
 408                         send_client(rnh, client, RNH_IMPORT_CHECK_TYPE, vrfid);
 409                 }
 410         }
 411 }
 412
 413 /*
 414  * Notify clients registered for this nexthop about a change.
 415  */
 416 static void zebra_rnh_notify_protocol_clients(
 417         struct zebra_vrf *zvrf, int family, struct route_node *nrn,
 418         struct rnh *rnh, struct route_node *prn, struct route_entry *re)
 419 {
 420         struct listnode *node;
 421         struct zserv *client;
 422         char bufn[INET6_ADDRSTRLEN];
 423         char bufp[INET6_ADDRSTRLEN];
 424         int num_resolving_nh;
 425
 426         if (IS_ZEBRA_DEBUG_NHT) {
 427                 prefix2str(&nrn->p, bufn, INET6_ADDRSTRLEN);
 428                 if (prn && re) {
 429                         prefix2str(&prn->p, bufp, INET6_ADDRSTRLEN);
 430                         zlog_debug("%u:%s: NH resolved over route %s",
 431                                    zvrf->vrf->vrf_id, bufn, bufp);
 432                 } else
 433                         zlog_debug("%u:%s: NH has become unresolved",
 434                                    zvrf->vrf->vrf_id, bufn);
 435         }
 436
 437         for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client)) {
 438                 if (prn && re) {
 439                         /* Apply route-map for this client to route resolving
 440                          * this
 441                          * nexthop to see if it is filtered or not.
 442                          */
 443                         num_resolving_nh = zebra_rnh_apply_nht_rmap(
 444                                 family, zvrf, prn, re, client->proto);
 445                         if (num_resolving_nh)
 446                                 rnh->filtered[client->proto] = 0;
 447                         else
 448                                 rnh->filtered[client->proto] = 1;
 449
 450                         if (IS_ZEBRA_DEBUG_NHT)
 451                                 zlog_debug(
 452                                         "%u:%s: Notifying client %s about NH %s",
 453                                         zvrf->vrf->vrf_id, bufn,
 454                                         zebra_route_string(client->proto),
 455                                         num_resolving_nh
 456                                                 ? ""
 457                                                 : "(filtered by route-map)");
 458                 } else {
 459                         rnh->filtered[client->proto] = 0;
 460                         if (IS_ZEBRA_DEBUG_NHT)
 461                                 zlog_debug(
 462                                         "%u:%s: Notifying client %s about NH (unreachable)",
 463                                         zvrf->vrf->vrf_id, bufn,
 464                                         zebra_route_string(client->proto));
 465                 }
 466
 467                 send_client(rnh, client, RNH_NEXTHOP_TYPE, zvrf->vrf->vrf_id);
 468         }
 469 }
 470
 471 static void zebra_rnh_process_pbr_tables(int family,
 472                                          struct route_node *nrn,
 473                                          struct rnh *rnh,
 474                                          struct route_node *prn,
 475                                          struct route_entry *re)
 476 {
 477         struct zebra_router_table *zrt;
 478         struct route_entry *o_re;
 479         struct route_node *o_rn;
 480         struct listnode *node;
 481         struct zserv *client;
 482         afi_t afi = AFI_IP;
 483
 484         if (family == AF_INET6)
 485                 afi = AFI_IP6;
 486
 487         /*
 488          * We are only concerned about nexthops that change for
 489          * anyone using PBR
 490          */
 491         for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client)) {
 492                 if (client->proto == ZEBRA_ROUTE_PBR)
 493                         break;
 494         }
 495
 496         if (!client)
 497                 return;
 498
 499         RB_FOREACH (zrt, zebra_router_table_head, &zrouter.tables) {
 500                 if (afi != zrt->afi)
 501                         continue;
 502
 503                 for (o_rn = route_top(zrt->table); o_rn;
 504                      o_rn = srcdest_route_next(o_rn)) {
 505                         RNODE_FOREACH_RE (o_rn, o_re) {
 506                                 if (o_re->type == ZEBRA_ROUTE_PBR)
 507                                         break;
 508
 509                         }
 510
 511                         /*
 512                          * If we have a PBR route and a nexthop changes
 513                          * just rethink it.  Yes this is a hammer, but
 514                          * a small one
 515                          */
 516                         if (o_re) {
 517                                 SET_FLAG(o_re->status, ROUTE_ENTRY_CHANGED);
 518                                 rib_queue_add(o_rn);
 519                         }
 520                 }
 521         }
 522 }
 523
 524 /*
 525  * Utility to determine whether a candidate nexthop is useable. We make this
 526  * check in a couple of places, so this is a single home for the logic we
 527  * use.
 528  */
 529 static bool rnh_nexthop_valid(const struct nexthop *nh)
 530 {
 531         return (CHECK_FLAG(nh->flags, NEXTHOP_FLAG_FIB)
 532                 && CHECK_FLAG(nh->flags, NEXTHOP_FLAG_ACTIVE));
 533 }
 534
 535 /*
 536  * Determine appropriate route (route entry) resolving a tracked
 537  * nexthop.
 538  */
 539 static struct route_entry *
 540 zebra_rnh_resolve_nexthop_entry(struct zebra_vrf *zvrf, int family,
 541                                 struct route_node *nrn, struct rnh *rnh,
 542                                 struct route_node **prn)
 543 {
 544         struct route_table *route_table;
 545         struct route_node *rn;
 546         struct route_entry *re;
 547         struct nexthop *nexthop;
 548
 549         *prn = NULL;
 550
 551         route_table = zvrf->table[family2afi(family)][SAFI_UNICAST];
 552         if (!route_table)
 553                 return NULL;
 554
 555         rn = route_node_match(route_table, &nrn->p);
 556         if (!rn)
 557                 return NULL;
 558
 559         /* Unlock route node - we don't need to lock when walking the tree. */
 560         route_unlock_node(rn);
 561
 562         /* While resolving nexthops, we may need to walk up the tree from the
 563          * most-specific match. Do similar logic as in zebra_rib.c
 564          */
 565         while (rn) {
 566                 /* Do not resolve over default route unless allowed &&
 567                  * match route to be exact if so specified
 568                  */
 569                 if (is_default_prefix(&rn->p)
 570                     && !rnh_resolve_via_default(rn->p.family))
 571                         return NULL;
 572
 573                 /* Identify appropriate route entry. */
 574                 RNODE_FOREACH_RE (rn, re) {
 575                         if (CHECK_FLAG(re->status, ROUTE_ENTRY_REMOVED))
 576                                 continue;
 577                         if (!CHECK_FLAG(re->flags, ZEBRA_FLAG_SELECTED))
 578                                 continue;
 579
 580                         /* Just being SELECTED isn't quite enough - must
 581                          * have an installed nexthop to be useful.
 582                          */
 583                         for (ALL_NEXTHOPS(re->ng, nexthop)) {
 584                                 if (rnh_nexthop_valid(nexthop))
 585                                         break;
 586                         }
 587
 588                         if (nexthop == NULL)
 589                                 continue;
 590
 591                         if (CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED)) {
 592                                 if ((re->type == ZEBRA_ROUTE_CONNECT)
 593                                     || (re->type == ZEBRA_ROUTE_STATIC))
 594                                         break;
 595                                 if (re->type == ZEBRA_ROUTE_NHRP) {
 596
 597                                         for (nexthop = re->ng.nexthop; nexthop;
 598                                              nexthop = nexthop->next)
 599                                                 if (nexthop->type
 600                                                     == NEXTHOP_TYPE_IFINDEX)
 601                                                         break;
 602                                         if (nexthop)
 603                                                 break;
 604                                 }
 605                         } else
 606                                 break;
 607                 }
 608
 609                 /* Route entry found, we're done; else, walk up the tree. */
 610                 if (re) {
 611                         *prn = rn;
 612                         return re;
 613                 }
 614
 615                 if (CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED))
 616                         rn = rn->parent;
 617                 else
 618                         return NULL;
 619         }
 620
 621         return NULL;
 622 }
 623
 624 static void zebra_rnh_process_pseudowires(vrf_id_t vrfid, struct rnh *rnh)
 625 {
 626         struct zebra_pw *pw;
 627         struct listnode *node;
 628
 629         for (ALL_LIST_ELEMENTS_RO(rnh->zebra_pseudowire_list, node, pw))
 630                 zebra_pw_update(pw);
 631 }
 632
 633 /*
 634  * See if a tracked nexthop entry has undergone any change, and if so,
 635  * take appropriate action; this involves notifying any clients and/or
 636  * scheduling dependent static routes for processing.
 637  */
 638 static void zebra_rnh_eval_nexthop_entry(struct zebra_vrf *zvrf, int family,
 639                                          int force, struct route_node *nrn,
 640                                          struct rnh *rnh,
 641                                          struct route_node *prn,
 642                                          struct route_entry *re)
 643 {
 644         int state_changed = 0;
 645
 646         /* If we're resolving over a different route, resolution has changed or
 647          * the resolving route has some change (e.g., metric), there is a state
 648          * change.
 649          */
 650         if (!prefix_same(&rnh->resolved_route, &prn->p)) {
 651                 if (prn)
 652                         prefix_copy(&rnh->resolved_route, &prn->p);
 653                 else
 654                         memset(&rnh->resolved_route, 0, sizeof(struct prefix));
 655
 656                 copy_state(rnh, re, nrn);
 657                 state_changed = 1;
 658         } else if (compare_state(re, rnh->state)) {
 659                 copy_state(rnh, re, nrn);
 660                 state_changed = 1;
 661         }
 662
 663         if (state_changed || force) {
 664                 /* NOTE: Use the "copy" of resolving route stored in 'rnh' i.e.,
 665                  * rnh->state.
 666                  */
 667                 /* Notify registered protocol clients. */
 668                 zebra_rnh_notify_protocol_clients(zvrf, family, nrn, rnh, prn,
 669                                                   rnh->state);
 670
 671                 zebra_rnh_process_pbr_tables(family, nrn, rnh, prn, rnh->state);
 672
 673                 /* Process pseudowires attached to this nexthop */
 674                 zebra_rnh_process_pseudowires(zvrf->vrf->vrf_id, rnh);
 675         }
 676 }
 677
 678 /* Evaluate one tracked entry */
 679 static void zebra_rnh_evaluate_entry(struct zebra_vrf *zvrf, int family,
 680                                      int force, rnh_type_t type,
 681                                      struct route_node *nrn)
 682 {
 683         struct rnh *rnh;
 684         struct route_entry *re;
 685         struct route_node *prn;
 686         char bufn[INET6_ADDRSTRLEN];
 687
 688         if (IS_ZEBRA_DEBUG_NHT) {
 689                 prefix2str(&nrn->p, bufn, INET6_ADDRSTRLEN);
 690                 zlog_debug("%u:%s: Evaluate RNH, type %d %s", zvrf->vrf->vrf_id,
 691                            bufn, type, force ? "(force)" : "");
 692         }
 693
 694         rnh = nrn->info;
 695
 696         /* Identify route entry (RE) resolving this tracked entry. */
 697         if (type == RNH_IMPORT_CHECK_TYPE)
 698                 re = zebra_rnh_resolve_import_entry(zvrf, family, nrn, rnh,
 699                                                     &prn);
 700         else
 701                 re = zebra_rnh_resolve_nexthop_entry(zvrf, family, nrn, rnh,
 702                                                      &prn);
 703
 704         /* If the entry cannot be resolved and that is also the existing state,
 705          * there is nothing further to do.
 706          */
 707         if (!re && rnh->state == NULL && !force)
 708                 return;
 709
 710         /* Process based on type of entry. */
 711         if (type == RNH_IMPORT_CHECK_TYPE)
 712                 zebra_rnh_eval_import_check_entry(zvrf->vrf->vrf_id, family,
 713                                                   force, nrn, rnh, re);
 714         else
 715                 zebra_rnh_eval_nexthop_entry(zvrf, family, force, nrn, rnh, prn,
 716                                              re);
 717 }
 718
 719 /*
 720  * Clear the ROUTE_ENTRY_NEXTHOPS_CHANGED flag
 721  * from the re entries.
 722  *
 723  * Please note we are doing this *after* we have
 724  * notified the world about each nexthop as that
 725  * we can have a situation where one re entry
 726  * covers multiple nexthops we are interested in.
 727  */
 728 static void zebra_rnh_clear_nhc_flag(struct zebra_vrf *zvrf, int family,
 729                                      rnh_type_t type, struct route_node *nrn)
 730 {
 731         struct rnh *rnh;
 732         struct route_entry *re;
 733         struct route_node *prn;
 734
 735         rnh = nrn->info;
 736
 737         /* Identify route entry (RIB) resolving this tracked entry. */
 738         if (type == RNH_IMPORT_CHECK_TYPE)
 739                 re = zebra_rnh_resolve_import_entry(zvrf, family, nrn, rnh,
 740                                                     &prn);
 741         else
 742                 re = zebra_rnh_resolve_nexthop_entry(zvrf, family, nrn, rnh,
 743                                                      &prn);
 744
 745         if (re) {
 746                 UNSET_FLAG(re->status, ROUTE_ENTRY_NEXTHOPS_CHANGED);
 747                 UNSET_FLAG(re->status, ROUTE_ENTRY_LABELS_CHANGED);
 748         }
 749 }
 750
 751 /* Evaluate all tracked entries (nexthops or routes for import into BGP)
 752  * of a particular VRF and address-family or a specific prefix.
 753  */
 754 void zebra_evaluate_rnh(struct zebra_vrf *zvrf, int family, int force,
 755                         rnh_type_t type, struct prefix *p)
 756 {
 757         struct route_table *rnh_table;
 758         struct route_node *nrn;
 759
 760         rnh_table = get_rnh_table(zvrf->vrf->vrf_id, family, type);
 761         if (!rnh_table) // unexpected
 762                 return;
 763
 764         if (p) {
 765                 /* Evaluating a specific entry, make sure it exists. */
 766                 nrn = route_node_lookup(rnh_table, p);
 767                 if (nrn && nrn->info)
 768                         zebra_rnh_evaluate_entry(zvrf, family, force, type,
 769                                                  nrn);
 770
 771                 if (nrn)
 772                         route_unlock_node(nrn);
 773         } else {
 774                 /* Evaluate entire table. */
 775                 nrn = route_top(rnh_table);
 776                 while (nrn) {
 777                         if (nrn->info)
 778                                 zebra_rnh_evaluate_entry(zvrf, family, force,
 779                                                          type, nrn);
 780                         nrn = route_next(nrn); /* this will also unlock nrn */
 781                 }
 782                 nrn = route_top(rnh_table);
 783                 while (nrn) {
 784                         if (nrn->info)
 785                                 zebra_rnh_clear_nhc_flag(zvrf, family, type,
 786                                                          nrn);
 787                         nrn = route_next(nrn); /* this will also unlock nrn */
 788                 }
 789         }
 790 }
 791
 792 void zebra_print_rnh_table(vrf_id_t vrfid, int af, struct vty *vty,
 793                            rnh_type_t type)
 794 {
 795         struct route_table *table;
 796         struct route_node *rn;
 797
 798         table = get_rnh_table(vrfid, af, type);
 799         if (!table) {
 800                 zlog_debug("print_rnhs: rnh table not found\n");
 801                 return;
 802         }
 803
 804         for (rn = route_top(table); rn; rn = route_next(rn))
 805                 if (rn->info)
 806                         print_rnh(rn, vty);
 807 }
 808
 809 /**
 810  * free_state - free up the re structure associated with the rnh.
 811  */
 812 static void free_state(vrf_id_t vrf_id, struct route_entry *re,
 813                        struct route_node *rn)
 814 {
 815
 816         if (!re)
 817                 return;
 818
 819         /* free RE and nexthops */
 820         nexthops_free(re->ng.nexthop);
 821         XFREE(MTYPE_RE, re);
 822 }
 823
 824 static void copy_state(struct rnh *rnh, struct route_entry *re,
 825                        struct route_node *rn)
 826 {
 827         struct route_entry *state;
 828
 829         if (rnh->state) {
 830                 free_state(rnh->vrf_id, rnh->state, rn);
 831                 rnh->state = NULL;
 832         }
 833
 834         if (!re)
 835                 return;
 836
 837         state = XCALLOC(MTYPE_RE, sizeof(struct route_entry));
 838         state->type = re->type;
 839         state->distance = re->distance;
 840         state->metric = re->metric;
 841         state->vrf_id = re->vrf_id;
 842
 843         route_entry_copy_nexthops(state, re->ng.nexthop);
 844         rnh->state = state;
 845 }
 846
 847 static int compare_state(struct route_entry *r1, struct route_entry *r2)
 848 {
 849
 850         if (!r1 && !r2)
 851                 return 0;
 852
 853         if ((!r1 && r2) || (r1 && !r2))
 854                 return 1;
 855
 856         if (r1->distance != r2->distance)
 857                 return 1;
 858
 859         if (r1->metric != r2->metric)
 860                 return 1;
 861
 862         if (r1->nexthop_num != r2->nexthop_num)
 863                 return 1;
 864
 865         if (CHECK_FLAG(r1->status, ROUTE_ENTRY_NEXTHOPS_CHANGED)
 866             || CHECK_FLAG(r1->status, ROUTE_ENTRY_LABELS_CHANGED))
 867                 return 1;
 868
 869         return 0;
 870 }
 871
 872 static int send_client(struct rnh *rnh, struct zserv *client, rnh_type_t type,
 873                        vrf_id_t vrf_id)
 874 {
 875         struct stream *s;
 876         struct route_entry *re;
 877         unsigned long nump;
 878         uint8_t num;
 879         struct nexthop *nh;
 880         struct route_node *rn;
 881         int cmd = (type == RNH_IMPORT_CHECK_TYPE) ? ZEBRA_IMPORT_CHECK_UPDATE
 882                                                   : ZEBRA_NEXTHOP_UPDATE;
 883
 884         rn = rnh->node;
 885         re = rnh->state;
 886
 887         /* Get output stream. */
 888         s = stream_new(ZEBRA_MAX_PACKET_SIZ);
 889
 890         zclient_create_header(s, cmd, vrf_id);
 891
 892         stream_putw(s, rn->p.family);
 893         switch (rn->p.family) {
 894         case AF_INET:
 895                 stream_putc(s, rn->p.prefixlen);
 896                 stream_put_in_addr(s, &rn->p.u.prefix4);
 897                 break;
 898         case AF_INET6:
 899                 stream_putc(s, rn->p.prefixlen);
 900                 stream_put(s, &rn->p.u.prefix6, IPV6_MAX_BYTELEN);
 901                 break;
 902         default:
 903                 flog_err(EC_ZEBRA_RNH_UNKNOWN_FAMILY,
 904                          "%s: Unknown family (%d) notification attempted\n",
 905                          __FUNCTION__, rn->p.family);
 906                 break;
 907         }
 908         if (re) {
 909                 stream_putc(s, re->type);
 910                 stream_putw(s, re->instance);
 911                 stream_putc(s, re->distance);
 912                 stream_putl(s, re->metric);
 913                 num = 0;
 914                 nump = stream_get_endp(s);
 915                 stream_putc(s, 0);
 916                 for (ALL_NEXTHOPS(re->ng, nh))
 917                         if (rnh_nexthop_valid(nh)) {
 918                                 stream_putl(s, nh->vrf_id);
 919                                 stream_putc(s, nh->type);
 920                                 switch (nh->type) {
 921                                 case NEXTHOP_TYPE_IPV4:
 922                                 case NEXTHOP_TYPE_IPV4_IFINDEX:
 923                                         stream_put_in_addr(s, &nh->gate.ipv4);
 924                                         stream_putl(s, nh->ifindex);
 925                                         break;
 926                                 case NEXTHOP_TYPE_IFINDEX:
 927                                         stream_putl(s, nh->ifindex);
 928                                         break;
 929                                 case NEXTHOP_TYPE_IPV6:
 930                                 case NEXTHOP_TYPE_IPV6_IFINDEX:
 931                                         stream_put(s, &nh->gate.ipv6, 16);
 932                                         stream_putl(s, nh->ifindex);
 933                                         break;
 934                                 default:
 935                                         /* do nothing */
 936                                         break;
 937                                 }
 938                                 if (nh->nh_label) {
 939                                         stream_putc(s,
 940                                                     nh->nh_label->num_labels);
 941                                         if (nh->nh_label->num_labels)
 942                                                 stream_put(
 943                                                         s,
 944                                                         &nh->nh_label->label[0],
 945                                                         nh->nh_label->num_labels
 946                                                                 * sizeof(mpls_label_t));
 947                                 } else
 948                                         stream_putc(s, 0);
 949                                 num++;
 950                         }
 951                 stream_putc_at(s, nump, num);
 952         } else {
 953                 stream_putc(s, 0); // type
 954                 stream_putw(s, 0); // instance
 955                 stream_putc(s, 0); // distance
 956                 stream_putl(s, 0); // metric
 957                 stream_putc(s, 0); // nexthops
 958         }
 959         stream_putw_at(s, 0, stream_get_endp(s));
 960
 961         client->nh_last_upd_time = monotime(NULL);
 962         client->last_write_cmd = cmd;
 963         return zserv_send_message(client, s);
 964 }
 965
 966 static void print_nh(struct nexthop *nexthop, struct vty *vty)
 967 {
 968         char buf[BUFSIZ];
 969         struct zebra_ns *zns = zebra_ns_lookup(NS_DEFAULT);
 970
 971         switch (nexthop->type) {
 972         case NEXTHOP_TYPE_IPV4:
 973         case NEXTHOP_TYPE_IPV4_IFINDEX:
 974                 vty_out(vty, " via %s", inet_ntoa(nexthop->gate.ipv4));
 975                 if (nexthop->ifindex)
 976                         vty_out(vty, ", %s",
 977                                 ifindex2ifname_per_ns(zns, nexthop->ifindex));
 978                 break;
 979         case NEXTHOP_TYPE_IPV6:
 980         case NEXTHOP_TYPE_IPV6_IFINDEX:
 981                 vty_out(vty, " %s",
 982                         inet_ntop(AF_INET6, &nexthop->gate.ipv6, buf, BUFSIZ));
 983                 if (nexthop->ifindex)
 984                         vty_out(vty, ", via %s",
 985                                 ifindex2ifname_per_ns(zns, nexthop->ifindex));
 986                 break;
 987         case NEXTHOP_TYPE_IFINDEX:
 988                 vty_out(vty, " is directly connected, %s",
 989                         ifindex2ifname_per_ns(zns, nexthop->ifindex));
 990                 break;
 991         case NEXTHOP_TYPE_BLACKHOLE:
 992                 vty_out(vty, " is directly connected, Null0");
 993                 break;
 994         default:
 995                 break;
 996         }
 997         vty_out(vty, "\n");
 998 }
 999
1000 static void print_rnh(struct route_node *rn, struct vty *vty)
1001 {
1002         struct rnh *rnh;
1003         struct nexthop *nexthop;
1004         struct listnode *node;
1005         struct zserv *client;
1006         char buf[BUFSIZ];
1007
1008         rnh = rn->info;
1009         vty_out(vty, "%s%s\n",
1010                 inet_ntop(rn->p.family, &rn->p.u.prefix, buf, BUFSIZ),
1011                 CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED) ? "(Connected)"
1012                                                             : "");
1013         if (rnh->state) {
1014                 vty_out(vty, " resolved via %s\n",
1015                         zebra_route_string(rnh->state->type));
1016                 for (nexthop = rnh->state->ng.nexthop; nexthop;
1017                      nexthop = nexthop->next)
1018                         print_nh(nexthop, vty);
1019         } else
1020                 vty_out(vty, " unresolved%s\n",
1021                         CHECK_FLAG(rnh->flags, ZEBRA_NHT_CONNECTED)
1022                                 ? "(Connected)"
1023                                 : "");
1024
1025         vty_out(vty, " Client list:");
1026         for (ALL_LIST_ELEMENTS_RO(rnh->client_list, node, client))
1027                 vty_out(vty, " %s(fd %d)%s", zebra_route_string(client->proto),
1028                         client->sock,
1029                         rnh->filtered[client->proto] ? "(filtered)" : "");
1030         if (!list_isempty(rnh->zebra_pseudowire_list))
1031                 vty_out(vty, " zebra[pseudowires]");
1032         vty_out(vty, "\n");
1033 }
1034
1035 static int zebra_cleanup_rnh_client(vrf_id_t vrf_id, int family,
1036                                     struct zserv *client, rnh_type_t type)
1037 {
1038         struct route_table *ntable;
1039         struct route_node *nrn;
1040         struct rnh *rnh;
1041
1042         if (IS_ZEBRA_DEBUG_NHT)
1043                 zlog_debug("%u: Client %s RNH cleanup for family %d type %d",
1044                            vrf_id, zebra_route_string(client->proto), family,
1045                            type);
1046
1047         ntable = get_rnh_table(vrf_id, family, type);
1048         if (!ntable) {
1049                 zlog_debug("cleanup_rnh_client: rnh table not found\n");
1050                 return -1;
1051         }
1052
1053         for (nrn = route_top(ntable); nrn; nrn = route_next(nrn)) {
1054                 if (!nrn->info)
1055                         continue;
1056
1057                 rnh = nrn->info;
1058                 zebra_remove_rnh_client(rnh, client, type);
1059         }
1060         return 1;
1061 }
1062
1063 /* Cleanup registered nexthops (across VRFs) upon client disconnect. */
1064 static int zebra_client_cleanup_rnh(struct zserv *client)
1065 {
1066         struct vrf *vrf;
1067         struct zebra_vrf *zvrf;
1068
1069         RB_FOREACH (vrf, vrf_id_head, &vrfs_by_id) {
1070                 zvrf = vrf->info;
1071                 if (zvrf) {
1072                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AF_INET, client,
1073                                                  RNH_NEXTHOP_TYPE);
1074                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AF_INET6,
1075                                                  client, RNH_NEXTHOP_TYPE);
1076                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AF_INET, client,
1077                                                  RNH_IMPORT_CHECK_TYPE);
1078                         zebra_cleanup_rnh_client(zvrf_id(zvrf), AF_INET6,
1079                                                  client, RNH_IMPORT_CHECK_TYPE);
1080                         if (client->proto == ZEBRA_ROUTE_LDP) {
1081                                 hash_iterate(zvrf->lsp_table,
1082                                              mpls_ldp_lsp_uninstall_all,
1083                                              zvrf->lsp_table);
1084                                 mpls_ldp_ftn_uninstall_all(zvrf, AFI_IP);
1085                                 mpls_ldp_ftn_uninstall_all(zvrf, AFI_IP6);
1086                         }
1087                 }
1088         }
1089
1090         return 0;
1091 }