src/resolve/resolved-dns-zone.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include "alloc-util.h"
   4 #include "dns-domain.h"
   5 #include "list.h"
   6 #include "resolved-dns-packet.h"
   7 #include "resolved-dns-zone.h"
   8 #include "resolved-dnssd.h"
   9 #include "string-util.h"
  10
  11 /* Never allow more than 1K entries */
  12 #define ZONE_MAX 1024
  13
  14 void dns_zone_item_probe_stop(DnsZoneItem *i) {
  15         DnsTransaction *t;
  16         assert(i);
  17
  18         if (!i->probe_transaction)
  19                 return;
  20
  21         t = TAKE_PTR(i->probe_transaction);
  22
  23         set_remove(t->notify_zone_items, i);
  24         set_remove(t->notify_zone_items_done, i);
  25         dns_transaction_gc(t);
  26 }
  27
  28 static void dns_zone_item_free(DnsZoneItem *i) {
  29         if (!i)
  30                 return;
  31
  32         dns_zone_item_probe_stop(i);
  33         dns_resource_record_unref(i->rr);
  34
  35         free(i);
  36 }
  37
  38 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsZoneItem*, dns_zone_item_free);
  39
  40 static void dns_zone_item_remove_and_free(DnsZone *z, DnsZoneItem *i) {
  41         DnsZoneItem *first;
  42
  43         assert(z);
  44
  45         if (!i)
  46                 return;
  47
  48         first = hashmap_get(z->by_key, i->rr->key);
  49         LIST_REMOVE(by_key, first, i);
  50         if (first)
  51                 assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0);
  52         else
  53                 hashmap_remove(z->by_key, i->rr->key);
  54
  55         first = hashmap_get(z->by_name, dns_resource_key_name(i->rr->key));
  56         LIST_REMOVE(by_name, first, i);
  57         if (first)
  58                 assert_se(hashmap_replace(z->by_name, dns_resource_key_name(first->rr->key), first) >= 0);
  59         else
  60                 hashmap_remove(z->by_name, dns_resource_key_name(i->rr->key));
  61
  62         dns_zone_item_free(i);
  63 }
  64
  65 void dns_zone_flush(DnsZone *z) {
  66         DnsZoneItem *i;
  67
  68         assert(z);
  69
  70         while ((i = hashmap_first(z->by_key)))
  71                 dns_zone_item_remove_and_free(z, i);
  72
  73         assert(hashmap_size(z->by_key) == 0);
  74         assert(hashmap_size(z->by_name) == 0);
  75
  76         z->by_key = hashmap_free(z->by_key);
  77         z->by_name = hashmap_free(z->by_name);
  78 }
  79
  80 DnsZoneItem* dns_zone_get(DnsZone *z, DnsResourceRecord *rr) {
  81         DnsZoneItem *i;
  82
  83         assert(z);
  84         assert(rr);
  85
  86         LIST_FOREACH(by_key, i, hashmap_get(z->by_key, rr->key))
  87                 if (dns_resource_record_equal(i->rr, rr) > 0)
  88                         return i;
  89
  90         return NULL;
  91 }
  92
  93 void dns_zone_remove_rr(DnsZone *z, DnsResourceRecord *rr) {
  94         DnsZoneItem *i;
  95
  96         assert(z);
  97         assert(rr);
  98
  99         i = dns_zone_get(z, rr);
 100         if (i)
 101                 dns_zone_item_remove_and_free(z, i);
 102 }
 103
 104 int dns_zone_remove_rrs_by_key(DnsZone *z, DnsResourceKey *key) {
 105         _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL;
 106         DnsResourceRecord *rr;
 107         bool tentative;
 108         int r;
 109
 110         r = dns_zone_lookup(z, key, 0, &answer, &soa, &tentative);
 111         if (r < 0)
 112                 return r;
 113
 114         DNS_ANSWER_FOREACH(rr, answer)
 115                 dns_zone_remove_rr(z, rr);
 116
 117         return 0;
 118 }
 119
 120 static int dns_zone_init(DnsZone *z) {
 121         int r;
 122
 123         assert(z);
 124
 125         r = hashmap_ensure_allocated(&z->by_key, &dns_resource_key_hash_ops);
 126         if (r < 0)
 127                 return r;
 128
 129         r = hashmap_ensure_allocated(&z->by_name, &dns_name_hash_ops);
 130         if (r < 0)
 131                 return r;
 132
 133         return 0;
 134 }
 135
 136 static int dns_zone_link_item(DnsZone *z, DnsZoneItem *i) {
 137         DnsZoneItem *first;
 138         int r;
 139
 140         first = hashmap_get(z->by_key, i->rr->key);
 141         if (first) {
 142                 LIST_PREPEND(by_key, first, i);
 143                 assert_se(hashmap_replace(z->by_key, first->rr->key, first) >= 0);
 144         } else {
 145                 r = hashmap_put(z->by_key, i->rr->key, i);
 146                 if (r < 0)
 147                         return r;
 148         }
 149
 150         first = hashmap_get(z->by_name, dns_resource_key_name(i->rr->key));
 151         if (first) {
 152                 LIST_PREPEND(by_name, first, i);
 153                 assert_se(hashmap_replace(z->by_name, dns_resource_key_name(first->rr->key), first) >= 0);
 154         } else {
 155                 r = hashmap_put(z->by_name, dns_resource_key_name(i->rr->key), i);
 156                 if (r < 0)
 157                         return r;
 158         }
 159
 160         return 0;
 161 }
 162
 163 static int dns_zone_item_probe_start(DnsZoneItem *i)  {
 164         DnsTransaction *t;
 165         int r;
 166
 167         assert(i);
 168
 169         if (i->probe_transaction)
 170                 return 0;
 171
 172         t = dns_scope_find_transaction(i->scope, &DNS_RESOURCE_KEY_CONST(i->rr->key->class, DNS_TYPE_ANY, dns_resource_key_name(i->rr->key)), false);
 173         if (!t) {
 174                 _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
 175
 176                 key = dns_resource_key_new(i->rr->key->class, DNS_TYPE_ANY, dns_resource_key_name(i->rr->key));
 177                 if (!key)
 178                         return -ENOMEM;
 179
 180                 r = dns_transaction_new(&t, i->scope, key);
 181                 if (r < 0)
 182                         return r;
 183         }
 184
 185         r = set_ensure_allocated(&t->notify_zone_items, NULL);
 186         if (r < 0)
 187                 goto gc;
 188
 189         r = set_ensure_allocated(&t->notify_zone_items_done, NULL);
 190         if (r < 0)
 191                 goto gc;
 192
 193         r = set_put(t->notify_zone_items, i);
 194         if (r < 0)
 195                 goto gc;
 196
 197         i->probe_transaction = t;
 198         t->probing = true;
 199
 200         if (t->state == DNS_TRANSACTION_NULL) {
 201
 202                 i->block_ready++;
 203                 r = dns_transaction_go(t);
 204                 i->block_ready--;
 205
 206                 if (r < 0) {
 207                         dns_zone_item_probe_stop(i);
 208                         return r;
 209                 }
 210         }
 211
 212         dns_zone_item_notify(i);
 213         return 0;
 214
 215 gc:
 216         dns_transaction_gc(t);
 217         return r;
 218 }
 219
 220 int dns_zone_put(DnsZone *z, DnsScope *s, DnsResourceRecord *rr, bool probe) {
 221         _cleanup_(dns_zone_item_freep) DnsZoneItem *i = NULL;
 222         DnsZoneItem *existing;
 223         int r;
 224
 225         assert(z);
 226         assert(s);
 227         assert(rr);
 228
 229         if (dns_class_is_pseudo(rr->key->class))
 230                 return -EINVAL;
 231         if (dns_type_is_pseudo(rr->key->type))
 232                 return -EINVAL;
 233
 234         existing = dns_zone_get(z, rr);
 235         if (existing)
 236                 return 0;
 237
 238         r = dns_zone_init(z);
 239         if (r < 0)
 240                 return r;
 241
 242         i = new0(DnsZoneItem, 1);
 243         if (!i)
 244                 return -ENOMEM;
 245
 246         i->scope = s;
 247         i->rr = dns_resource_record_ref(rr);
 248         i->probing_enabled = probe;
 249
 250         r = dns_zone_link_item(z, i);
 251         if (r < 0)
 252                 return r;
 253
 254         if (probe) {
 255                 DnsZoneItem *first, *j;
 256                 bool established = false;
 257
 258                 /* Check if there's already an RR with the same name
 259                  * established. If so, it has been probed already, and
 260                  * we don't need to probe again. */
 261
 262                 LIST_FIND_HEAD(by_name, i, first);
 263                 LIST_FOREACH(by_name, j, first) {
 264                         if (i == j)
 265                                 continue;
 266
 267                         if (j->state == DNS_ZONE_ITEM_ESTABLISHED)
 268                                 established = true;
 269                 }
 270
 271                 if (established)
 272                         i->state = DNS_ZONE_ITEM_ESTABLISHED;
 273                 else {
 274                         i->state = DNS_ZONE_ITEM_PROBING;
 275
 276                         r = dns_zone_item_probe_start(i);
 277                         if (r < 0) {
 278                                 dns_zone_item_remove_and_free(z, i);
 279                                 i = NULL;
 280                                 return r;
 281                         }
 282                 }
 283         } else
 284                 i->state = DNS_ZONE_ITEM_ESTABLISHED;
 285
 286         i = NULL;
 287         return 0;
 288 }
 289
 290 static int dns_zone_add_authenticated_answer(DnsAnswer *a, DnsZoneItem *i, int ifindex) {
 291         DnsAnswerFlags flags;
 292
 293         /* From RFC 6762, Section 10.2
 294          * "They (the rules about when to set the cache-flush bit) apply to
 295          * startup announcements as described in Section 8.3, "Announcing",
 296          * and to responses generated as a result of receiving query messages."
 297          * So, set the cache-flush bit for mDNS answers except for DNS-SD
 298          * service enumeration PTRs described in RFC 6763, Section 4.1. */
 299         if (i->scope->protocol == DNS_PROTOCOL_MDNS &&
 300             !dns_resource_key_is_dnssd_ptr(i->rr->key))
 301                 flags = DNS_ANSWER_AUTHENTICATED|DNS_ANSWER_CACHE_FLUSH;
 302         else
 303                 flags = DNS_ANSWER_AUTHENTICATED;
 304
 305         return dns_answer_add(a, i->rr, ifindex, flags);
 306 }
 307
 308 int dns_zone_lookup(DnsZone *z, DnsResourceKey *key, int ifindex, DnsAnswer **ret_answer, DnsAnswer **ret_soa, bool *ret_tentative) {
 309         _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL;
 310         unsigned n_answer = 0;
 311         DnsZoneItem *j, *first;
 312         bool tentative = true, need_soa = false;
 313         int r;
 314
 315         /* Note that we don't actually need the ifindex for anything. However when it is passed we'll initialize the
 316          * ifindex field in the answer with it */
 317
 318         assert(z);
 319         assert(key);
 320         assert(ret_answer);
 321
 322         /* First iteration, count what we have */
 323
 324         if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) {
 325                 bool found = false, added = false;
 326                 int k;
 327
 328                 /* If this is a generic match, then we have to
 329                  * go through the list by the name and look
 330                  * for everything manually */
 331
 332                 first = hashmap_get(z->by_name, dns_resource_key_name(key));
 333                 LIST_FOREACH(by_name, j, first) {
 334                         if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING))
 335                                 continue;
 336
 337                         found = true;
 338
 339                         k = dns_resource_key_match_rr(key, j->rr, NULL);
 340                         if (k < 0)
 341                                 return k;
 342                         if (k > 0) {
 343                                 n_answer++;
 344                                 added = true;
 345                         }
 346
 347                 }
 348
 349                 if (found && !added)
 350                         need_soa = true;
 351
 352         } else {
 353                 bool found = false;
 354
 355                 /* If this is a specific match, then look for
 356                  * the right key immediately */
 357
 358                 first = hashmap_get(z->by_key, key);
 359                 LIST_FOREACH(by_key, j, first) {
 360                         if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING))
 361                                 continue;
 362
 363                         found = true;
 364                         n_answer++;
 365                 }
 366
 367                 if (!found) {
 368                         first = hashmap_get(z->by_name, dns_resource_key_name(key));
 369                         LIST_FOREACH(by_name, j, first) {
 370                                 if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING))
 371                                         continue;
 372
 373                                 need_soa = true;
 374                                 break;
 375                         }
 376                 }
 377         }
 378
 379         if (n_answer <= 0 && !need_soa)
 380                 goto return_empty;
 381
 382         if (n_answer > 0) {
 383                 answer = dns_answer_new(n_answer);
 384                 if (!answer)
 385                         return -ENOMEM;
 386         }
 387
 388         if (need_soa) {
 389                 soa = dns_answer_new(1);
 390                 if (!soa)
 391                         return -ENOMEM;
 392         }
 393
 394         /* Second iteration, actually add the RRs to the answers */
 395         if (key->type == DNS_TYPE_ANY || key->class == DNS_CLASS_ANY) {
 396                 bool found = false, added = false;
 397                 int k;
 398
 399                 first = hashmap_get(z->by_name, dns_resource_key_name(key));
 400                 LIST_FOREACH(by_name, j, first) {
 401                         if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING))
 402                                 continue;
 403
 404                         found = true;
 405
 406                         if (j->state != DNS_ZONE_ITEM_PROBING)
 407                                 tentative = false;
 408
 409                         k = dns_resource_key_match_rr(key, j->rr, NULL);
 410                         if (k < 0)
 411                                 return k;
 412                         if (k > 0) {
 413                                 r = dns_zone_add_authenticated_answer(answer, j, ifindex);
 414                                 if (r < 0)
 415                                         return r;
 416
 417                                 added = true;
 418                         }
 419                 }
 420
 421                 if (found && !added) {
 422                         r = dns_answer_add_soa(soa, dns_resource_key_name(key), LLMNR_DEFAULT_TTL, ifindex);
 423                         if (r < 0)
 424                                 return r;
 425                 }
 426         } else {
 427                 bool found = false;
 428
 429                 first = hashmap_get(z->by_key, key);
 430                 LIST_FOREACH(by_key, j, first) {
 431                         if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING))
 432                                 continue;
 433
 434                         found = true;
 435
 436                         if (j->state != DNS_ZONE_ITEM_PROBING)
 437                                 tentative = false;
 438
 439                         r = dns_zone_add_authenticated_answer(answer, j, ifindex);
 440                         if (r < 0)
 441                                 return r;
 442                 }
 443
 444                 if (!found) {
 445                         bool add_soa = false;
 446
 447                         first = hashmap_get(z->by_name, dns_resource_key_name(key));
 448                         LIST_FOREACH(by_name, j, first) {
 449                                 if (!IN_SET(j->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING))
 450                                         continue;
 451
 452                                 if (j->state != DNS_ZONE_ITEM_PROBING)
 453                                         tentative = false;
 454
 455                                 add_soa = true;
 456                         }
 457
 458                         if (add_soa) {
 459                                 r = dns_answer_add_soa(soa, dns_resource_key_name(key), LLMNR_DEFAULT_TTL, ifindex);
 460                                 if (r < 0)
 461                                         return r;
 462                         }
 463                 }
 464         }
 465
 466         /* If the caller sets ret_tentative to NULL, then use this as
 467          * indication to not return tentative entries */
 468
 469         if (!ret_tentative && tentative)
 470                 goto return_empty;
 471
 472         *ret_answer = TAKE_PTR(answer);
 473
 474         if (ret_soa)
 475                 *ret_soa = TAKE_PTR(soa);
 476
 477         if (ret_tentative)
 478                 *ret_tentative = tentative;
 479
 480         return 1;
 481
 482 return_empty:
 483         *ret_answer = NULL;
 484
 485         if (ret_soa)
 486                 *ret_soa = NULL;
 487
 488         if (ret_tentative)
 489                 *ret_tentative = false;
 490
 491         return 0;
 492 }
 493
 494 void dns_zone_item_conflict(DnsZoneItem *i) {
 495         assert(i);
 496
 497         if (!IN_SET(i->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_VERIFYING, DNS_ZONE_ITEM_ESTABLISHED))
 498                 return;
 499
 500         log_info("Detected conflict on %s", strna(dns_resource_record_to_string(i->rr)));
 501
 502         dns_zone_item_probe_stop(i);
 503
 504         /* Withdraw the conflict item */
 505         i->state = DNS_ZONE_ITEM_WITHDRAWN;
 506
 507         dnssd_signal_conflict(i->scope->manager, dns_resource_key_name(i->rr->key));
 508
 509         /* Maybe change the hostname */
 510         if (manager_is_own_hostname(i->scope->manager, dns_resource_key_name(i->rr->key)) > 0)
 511                 manager_next_hostname(i->scope->manager);
 512 }
 513
 514 void dns_zone_item_notify(DnsZoneItem *i) {
 515         assert(i);
 516         assert(i->probe_transaction);
 517
 518         if (i->block_ready > 0)
 519                 return;
 520
 521         if (IN_SET(i->probe_transaction->state, DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING))
 522                 return;
 523
 524         if (i->probe_transaction->state == DNS_TRANSACTION_SUCCESS) {
 525                 bool we_lost = false;
 526
 527                 /* The probe got a successful reply. If we so far
 528                  * weren't established we just give up.
 529                  *
 530                  * In LLMNR case if we already
 531                  * were established, and the peer has the
 532                  * lexicographically larger IP address we continue
 533                  * and defend it. */
 534
 535                 if (!IN_SET(i->state, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING)) {
 536                         log_debug("Got a successful probe for not yet established RR, we lost.");
 537                         we_lost = true;
 538                 } else if (i->probe_transaction->scope->protocol == DNS_PROTOCOL_LLMNR) {
 539                         assert(i->probe_transaction->received);
 540                         we_lost = memcmp(&i->probe_transaction->received->sender, &i->probe_transaction->received->destination, FAMILY_ADDRESS_SIZE(i->probe_transaction->received->family)) < 0;
 541                         if (we_lost)
 542                                 log_debug("Got a successful probe reply for an established RR, and we have a lexicographically larger IP address and thus lost.");
 543                 }
 544
 545                 if (we_lost) {
 546                         dns_zone_item_conflict(i);
 547                         return;
 548                 }
 549
 550                 log_debug("Got a successful probe reply, but peer has lexicographically lower IP address and thus lost.");
 551         }
 552
 553         log_debug("Record %s successfully probed.", strna(dns_resource_record_to_string(i->rr)));
 554
 555         dns_zone_item_probe_stop(i);
 556         i->state = DNS_ZONE_ITEM_ESTABLISHED;
 557 }
 558
 559 static int dns_zone_item_verify(DnsZoneItem *i) {
 560         int r;
 561
 562         assert(i);
 563
 564         if (i->state != DNS_ZONE_ITEM_ESTABLISHED)
 565                 return 0;
 566
 567         log_debug("Verifying RR %s", strna(dns_resource_record_to_string(i->rr)));
 568
 569         i->state = DNS_ZONE_ITEM_VERIFYING;
 570         r = dns_zone_item_probe_start(i);
 571         if (r < 0) {
 572                 log_error_errno(r, "Failed to start probing for verifying RR: %m");
 573                 i->state = DNS_ZONE_ITEM_ESTABLISHED;
 574                 return r;
 575         }
 576
 577         return 0;
 578 }
 579
 580 int dns_zone_check_conflicts(DnsZone *zone, DnsResourceRecord *rr) {
 581         DnsZoneItem *i, *first;
 582         int c = 0;
 583
 584         assert(zone);
 585         assert(rr);
 586
 587         /* This checks whether a response RR we received from somebody
 588          * else is one that we actually thought was uniquely ours. If
 589          * so, we'll verify our RRs. */
 590
 591         /* No conflict if we don't have the name at all. */
 592         first = hashmap_get(zone->by_name, dns_resource_key_name(rr->key));
 593         if (!first)
 594                 return 0;
 595
 596         /* No conflict if we have the exact same RR */
 597         if (dns_zone_get(zone, rr))
 598                 return 0;
 599
 600         /* No conflict if it is DNS-SD RR used for service enumeration. */
 601         if (dns_resource_key_is_dnssd_ptr(rr->key))
 602                 return 0;
 603
 604         /* OK, somebody else has RRs for the same name. Yuck! Let's
 605          * start probing again */
 606
 607         LIST_FOREACH(by_name, i, first) {
 608                 if (dns_resource_record_equal(i->rr, rr))
 609                         continue;
 610
 611                 dns_zone_item_verify(i);
 612                 c++;
 613         }
 614
 615         return c;
 616 }
 617
 618 int dns_zone_verify_conflicts(DnsZone *zone, DnsResourceKey *key) {
 619         DnsZoneItem *i, *first;
 620         int c = 0;
 621
 622         assert(zone);
 623
 624         /* Somebody else notified us about a possible conflict. Let's
 625          * verify if that's true. */
 626
 627         first = hashmap_get(zone->by_name, dns_resource_key_name(key));
 628         if (!first)
 629                 return 0;
 630
 631         LIST_FOREACH(by_name, i, first) {
 632                 dns_zone_item_verify(i);
 633                 c++;
 634         }
 635
 636         return c;
 637 }
 638
 639 void dns_zone_verify_all(DnsZone *zone) {
 640         DnsZoneItem *i;
 641         Iterator iterator;
 642
 643         assert(zone);
 644
 645         HASHMAP_FOREACH(i, zone->by_key, iterator) {
 646                 DnsZoneItem *j;
 647
 648                 LIST_FOREACH(by_key, j, i)
 649                         dns_zone_item_verify(j);
 650         }
 651 }
 652
 653 void dns_zone_dump(DnsZone *zone, FILE *f) {
 654         Iterator iterator;
 655         DnsZoneItem *i;
 656
 657         if (!zone)
 658                 return;
 659
 660         if (!f)
 661                 f = stdout;
 662
 663         HASHMAP_FOREACH(i, zone->by_key, iterator) {
 664                 DnsZoneItem *j;
 665
 666                 LIST_FOREACH(by_key, j, i) {
 667                         const char *t;
 668
 669                         t = dns_resource_record_to_string(j->rr);
 670                         if (!t) {
 671                                 log_oom();
 672                                 continue;
 673                         }
 674
 675                         fputc('\t', f);
 676                         fputs(t, f);
 677                         fputc('\n', f);
 678                 }
 679         }
 680 }
 681
 682 bool dns_zone_is_empty(DnsZone *zone) {
 683         if (!zone)
 684                 return true;
 685
 686         return hashmap_isempty(zone->by_key);
 687 }
 688
 689 bool dns_zone_contains_name(DnsZone *z, const char *name) {
 690         DnsZoneItem *i, *first;
 691
 692         first = hashmap_get(z->by_name, name);
 693         if (!first)
 694                 return false;
 695
 696         LIST_FOREACH(by_name, i, first) {
 697                 if (!IN_SET(i->state, DNS_ZONE_ITEM_PROBING, DNS_ZONE_ITEM_ESTABLISHED, DNS_ZONE_ITEM_VERIFYING))
 698                         continue;
 699
 700                 return true;
 701         }
 702
 703         return false;
 704 }