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