src/resolve/resolved-bus.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2014 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include "bus-errors.h"
  23 #include "bus-util.h"
  24
  25 #include "resolved.h"
  26 #include "resolved-dns-domain.h"
  27
  28 static int reply_query_state(DnsQuery *q) {
  29         _cleanup_free_ char *ip = NULL;
  30         const char *name;
  31         int r;
  32
  33         if (q->request_hostname)
  34                 name = q->request_hostname;
  35         else {
  36                 r = in_addr_to_string(q->request_family, &q->request_address, &ip);
  37                 if (r < 0)
  38                         return r;
  39
  40                 name = ip;
  41         }
  42
  43         switch (q->state) {
  44
  45         case DNS_TRANSACTION_NO_SERVERS:
  46                 return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
  47
  48         case DNS_TRANSACTION_TIMEOUT:
  49                 return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "Query timed out");
  50
  51         case DNS_TRANSACTION_ATTEMPTS_MAX_REACHED:
  52                 return sd_bus_reply_method_errorf(q->request, SD_BUS_ERROR_TIMEOUT, "All attempts to contact name servers or networks failed");
  53
  54         case DNS_TRANSACTION_RESOURCES:
  55                 return sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_RESOURCES, "Not enough resources");
  56
  57         case DNS_TRANSACTION_INVALID_REPLY:
  58                 return sd_bus_reply_method_errorf(q->request, BUS_ERROR_INVALID_REPLY, "Received invalid reply");
  59
  60         case DNS_TRANSACTION_FAILURE: {
  61                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
  62
  63                 if (q->answer_rcode == DNS_RCODE_NXDOMAIN)
  64                         sd_bus_error_setf(&error, _BUS_ERROR_DNS "NXDOMAIN", "'%s' not found", name);
  65                 else {
  66                         const char *rc, *n;
  67                         char p[3]; /* the rcode is 4 bits long */
  68
  69                         rc = dns_rcode_to_string(q->answer_rcode);
  70                         if (!rc) {
  71                                 sprintf(p, "%i", q->answer_rcode);
  72                                 rc = p;
  73                         }
  74
  75                         n = strappenda(_BUS_ERROR_DNS, rc);
  76                         sd_bus_error_setf(&error, n, "Could not resolve '%s', server or network returned error %s", name, rc);
  77                 }
  78
  79                 return sd_bus_reply_method_error(q->request, &error);
  80         }
  81
  82         case DNS_TRANSACTION_NULL:
  83         case DNS_TRANSACTION_PENDING:
  84         case DNS_TRANSACTION_SUCCESS:
  85         default:
  86                 assert_not_reached("Impossible state");
  87         }
  88 }
  89
  90 static int append_address(sd_bus_message *reply, DnsResourceRecord *rr, int ifindex) {
  91         int r;
  92
  93         assert(reply);
  94         assert(rr);
  95
  96         r = sd_bus_message_open_container(reply, 'r', "iayi");
  97         if (r < 0)
  98                 return r;
  99
 100         if (rr->key->type == DNS_TYPE_A) {
 101                 r = sd_bus_message_append(reply, "i", AF_INET);
 102                 if (r < 0)
 103                         return r;
 104
 105                 r = sd_bus_message_append_array(reply, 'y', &rr->a.in_addr, sizeof(struct in_addr));
 106
 107         } else if (rr->key->type == DNS_TYPE_AAAA) {
 108                 r = sd_bus_message_append(reply, "i", AF_INET6);
 109                 if (r < 0)
 110                         return r;
 111
 112                 r = sd_bus_message_append_array(reply, 'y', &rr->aaaa.in6_addr, sizeof(struct in6_addr));
 113         } else
 114                 return -EAFNOSUPPORT;
 115
 116         if (r < 0)
 117                 return r;
 118
 119         r = sd_bus_message_append(reply, "i", ifindex);
 120         if (r < 0)
 121                 return r;
 122
 123         r = sd_bus_message_close_container(reply);
 124         if (r < 0)
 125                 return r;
 126
 127         return 0;
 128 }
 129
 130 static void bus_method_resolve_hostname_complete(DnsQuery *q) {
 131         _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *cname = NULL, *canonical = NULL;
 132         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
 133         _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
 134         unsigned added = 0, i;
 135         int r, ifindex;
 136
 137         assert(q);
 138
 139         if (q->state != DNS_TRANSACTION_SUCCESS) {
 140                 r = reply_query_state(q);
 141                 goto finish;
 142         }
 143
 144         r = sd_bus_message_new_method_return(q->request, &reply);
 145         if (r < 0)
 146                 goto finish;
 147
 148         r = sd_bus_message_open_container(reply, 'a', "(iayi)");
 149         if (r < 0)
 150                 goto finish;
 151
 152         ifindex = q->answer_ifindex;
 153
 154         if (q->answer) {
 155                 answer = dns_answer_ref(q->answer);
 156
 157                 for (i = 0; i < answer->n_rrs; i++) {
 158                         r = dns_question_matches_rr(q->question, answer->rrs[i]);
 159                         if (r < 0)
 160                                 goto finish;
 161                         if (r == 0) {
 162                                 /* Hmm, if this is not an address record,
 163                                    maybe it's a cname? If so, remember this */
 164                                 r = dns_question_matches_cname(q->question, answer->rrs[i]);
 165                                 if (r < 0)
 166                                         goto finish;
 167                                 if (r > 0)
 168                                         cname = dns_resource_record_ref(answer->rrs[i]);
 169
 170                                 continue;
 171                         }
 172
 173                         r = append_address(reply, answer->rrs[i], ifindex);
 174                         if (r < 0)
 175                                 goto finish;
 176
 177                         if (!canonical)
 178                                 canonical = dns_resource_record_ref(answer->rrs[i]);
 179
 180                         added ++;
 181                 }
 182         }
 183
 184         if (added <= 0) {
 185                 if (!cname) {
 186                         r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "'%s' does not have any RR of requested type", q->request_hostname);
 187                         goto finish;
 188                 }
 189
 190                 /* This has a cname? Then update the query with the
 191                  * new cname. */
 192                 r = dns_query_cname_redirect(q, cname->cname.name);
 193                 if (r < 0) {
 194                         if (r == -ELOOP)
 195                                 r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_CNAME_LOOP, "CNAME loop on '%s'", q->request_hostname);
 196                         else
 197                                 r = sd_bus_reply_method_errno(q->request, -r, NULL);
 198
 199                         goto finish;
 200                 }
 201
 202                 /* Before we restart the query, let's see if any of
 203                  * the RRs we already got already answers our query */
 204                 for (i = 0; i < answer->n_rrs; i++) {
 205                         r = dns_question_matches_rr(q->question, answer->rrs[i]);
 206                         if (r < 0)
 207                                 goto finish;
 208                         if (r == 0)
 209                                 continue;
 210
 211                         r = append_address(reply, answer->rrs[i], ifindex);
 212                         if (r < 0)
 213                                 goto finish;
 214
 215                         if (!canonical)
 216                                 canonical = dns_resource_record_ref(answer->rrs[i]);
 217
 218                         added++;
 219                 }
 220
 221                 /* If we didn't find anything, then let's restart the
 222                  * query, this time with the cname */
 223                 if (added <= 0) {
 224                         r = dns_query_go(q);
 225                         if (r == -ESRCH) {
 226                                 r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
 227                                 goto finish;
 228                         }
 229                         if (r < 0) {
 230                                 r = sd_bus_reply_method_errno(q->request, -r, NULL);
 231                                 goto finish;
 232                         }
 233
 234                         return;
 235                 }
 236         }
 237
 238         r = sd_bus_message_close_container(reply);
 239         if (r < 0)
 240                 goto finish;
 241
 242         /* Return the precise spelling and uppercasing reported by the server */
 243         assert(canonical);
 244         r = sd_bus_message_append(reply, "s", DNS_RESOURCE_KEY_NAME(canonical->key));
 245         if (r < 0)
 246                 goto finish;
 247
 248         r = sd_bus_send(q->manager->bus, reply, NULL);
 249
 250 finish:
 251         if (r < 0) {
 252                 log_error("Failed to send hostname reply: %s", strerror(-r));
 253                 sd_bus_reply_method_errno(q->request, -r, NULL);
 254         }
 255
 256         dns_query_free(q);
 257 }
 258
 259 static int bus_method_resolve_hostname(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
 260         _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
 261         Manager *m = userdata;
 262         const char *hostname;
 263         int family;
 264         DnsQuery *q;
 265         int r;
 266
 267         assert(bus);
 268         assert(message);
 269         assert(m);
 270
 271         r = sd_bus_message_read(message, "si", &hostname, &family);
 272         if (r < 0)
 273                 return r;
 274
 275         if (!IN_SET(family, AF_INET, AF_INET6, AF_UNSPEC))
 276                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family);
 277
 278         if (!hostname_is_valid(hostname))
 279                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid hostname '%s'", hostname);
 280
 281         question = dns_question_new(family == AF_UNSPEC ? 2 : 1);
 282         if (!question)
 283                 return -ENOMEM;
 284
 285         if (family != AF_INET6) {
 286                 _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
 287
 288                 key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_A, hostname);
 289                 if (!key)
 290                         return -ENOMEM;
 291
 292                 r = dns_question_add(question, key);
 293                 if (r < 0)
 294                         return r;
 295         }
 296
 297         if (family != AF_INET) {
 298                 _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
 299
 300                 key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_AAAA, hostname);
 301                 if (!key)
 302                         return -ENOMEM;
 303
 304                 r = dns_question_add(question, key);
 305                 if (r < 0)
 306                         return r;
 307         }
 308
 309         r = dns_query_new(m, &q, question);
 310         if (r < 0)
 311                 return r;
 312
 313         q->request = sd_bus_message_ref(message);
 314         q->request_family = family;
 315         q->request_hostname = hostname;
 316         q->complete = bus_method_resolve_hostname_complete;
 317
 318         r = dns_query_go(q);
 319         if (r < 0) {
 320                 dns_query_free(q);
 321
 322                 if (r == -ESRCH)
 323                         sd_bus_error_setf(error, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
 324
 325                 return r;
 326         }
 327
 328         return 1;
 329 }
 330
 331 static void bus_method_resolve_address_complete(DnsQuery *q) {
 332         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
 333         _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
 334         unsigned added = 0, i;
 335         int r;
 336
 337         assert(q);
 338
 339         if (q->state != DNS_TRANSACTION_SUCCESS) {
 340                 r = reply_query_state(q);
 341                 goto finish;
 342         }
 343
 344         r = sd_bus_message_new_method_return(q->request, &reply);
 345         if (r < 0)
 346                 goto finish;
 347
 348         r = sd_bus_message_open_container(reply, 'a', "s");
 349         if (r < 0)
 350                 goto finish;
 351
 352         if (q->answer) {
 353                 answer = dns_answer_ref(q->answer);
 354
 355                 for (i = 0; i < answer->n_rrs; i++) {
 356                         r = dns_question_matches_rr(q->question, answer->rrs[i]);
 357                         if (r < 0)
 358                                 goto finish;
 359                         if (r == 0)
 360                                 continue;
 361
 362                         r = sd_bus_message_append(reply, "s", answer->rrs[i]->ptr.name);
 363                         if (r < 0)
 364                                 goto finish;
 365
 366                         added ++;
 367                 }
 368         }
 369
 370         if (added <= 0) {
 371                 _cleanup_free_ char *ip = NULL;
 372
 373                 in_addr_to_string(q->request_family, &q->request_address, &ip);
 374
 375                 r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Address '%s' does not have any RR of requested type", ip);
 376                 goto finish;
 377         }
 378
 379         r = sd_bus_message_close_container(reply);
 380         if (r < 0)
 381                 goto finish;
 382
 383         r = sd_bus_send(q->manager->bus, reply, NULL);
 384
 385 finish:
 386         if (r < 0) {
 387                 log_error("Failed to send address reply: %s", strerror(-r));
 388                 sd_bus_reply_method_errno(q->request, -r, NULL);
 389         }
 390
 391         dns_query_free(q);
 392 }
 393
 394 static int bus_method_resolve_address(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
 395         _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
 396         _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
 397         _cleanup_free_ char *reverse = NULL;
 398         Manager *m = userdata;
 399         int family, ifindex;
 400         const void *d;
 401         DnsQuery *q;
 402         size_t sz;
 403         int r;
 404
 405         assert(bus);
 406         assert(message);
 407         assert(m);
 408
 409         r = sd_bus_message_read(message, "i", &family);
 410         if (r < 0)
 411                 return r;
 412
 413         if (!IN_SET(family, AF_INET, AF_INET6))
 414                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unknown address family %i", family);
 415
 416         r = sd_bus_message_read_array(message, 'y', &d, &sz);
 417         if (r < 0)
 418                 return r;
 419
 420         if (sz != FAMILY_ADDRESS_SIZE(family))
 421                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid address size");
 422
 423         r = sd_bus_message_read(message, "i", &ifindex);
 424         if (r < 0)
 425                 return r;
 426         if (ifindex < 0)
 427                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index");
 428
 429         r = dns_name_reverse(family, d, &reverse);
 430         if (r < 0)
 431                 return r;
 432
 433         question = dns_question_new(1);
 434         if (!question)
 435                 return -ENOMEM;
 436
 437         key = dns_resource_key_new_consume(DNS_CLASS_IN, DNS_TYPE_PTR, reverse);
 438         if (!key)
 439                 return -ENOMEM;
 440
 441         reverse = NULL;
 442
 443         r = dns_question_add(question, key);
 444         if (r < 0)
 445                 return r;
 446
 447         r = dns_query_new(m, &q, question);
 448         if (r < 0)
 449                 return r;
 450
 451         q->request = sd_bus_message_ref(message);
 452         q->request_family = family;
 453         memcpy(&q->request_address, d, sz);
 454         q->complete = bus_method_resolve_address_complete;
 455
 456         r = dns_query_go(q);
 457         if (r < 0) {
 458                 dns_query_free(q);
 459
 460                 if (r == -ESRCH)
 461                         sd_bus_error_setf(error, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
 462
 463                 return r;
 464         }
 465
 466         return 1;
 467 }
 468
 469 static void bus_method_resolve_record_complete(DnsQuery *q) {
 470         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
 471         _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL;
 472         unsigned added = 0, i;
 473         int r;
 474
 475         assert(q);
 476
 477         if (q->state != DNS_TRANSACTION_SUCCESS) {
 478                 r = reply_query_state(q);
 479                 goto finish;
 480         }
 481
 482         r = sd_bus_message_new_method_return(q->request, &reply);
 483         if (r < 0)
 484                 goto finish;
 485
 486         r = sd_bus_message_open_container(reply, 'a', "(qqay)");
 487         if (r < 0)
 488                 goto finish;
 489
 490         if (q->answer) {
 491                 answer = dns_answer_ref(q->answer);
 492
 493                 for (i = 0; i < answer->n_rrs; i++) {
 494                         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 495                         size_t start;
 496
 497                         r = dns_question_matches_rr(q->question, answer->rrs[i]);
 498                         if (r < 0)
 499                                 goto finish;
 500                         if (r == 0)
 501                                 continue;
 502
 503                         r = dns_packet_new(&p, DNS_PROTOCOL_DNS, 0);
 504                         if (r < 0)
 505                                 goto finish;
 506
 507                         r = dns_packet_append_rr(p, answer->rrs[i], &start);
 508                         if (r < 0)
 509                                 goto finish;
 510
 511                         r = sd_bus_message_open_container(reply, 'r', "qqay");
 512                         if (r < 0)
 513                                 goto finish;
 514
 515                         r = sd_bus_message_append(reply, "qq", answer->rrs[i]->key->class, answer->rrs[i]->key->type);
 516                         if (r < 0)
 517                                 goto finish;
 518
 519                         r = sd_bus_message_append_array(reply, 'y', DNS_PACKET_DATA(p) + start, p->size - start);
 520                         if (r < 0)
 521                                 goto finish;
 522
 523                         r = sd_bus_message_close_container(reply);
 524                         if (r < 0)
 525                                 goto finish;
 526
 527                         added ++;
 528                 }
 529         }
 530
 531         if (added <= 0) {
 532                 r = sd_bus_reply_method_errorf(q->request, BUS_ERROR_NO_SUCH_RR, "Name '%s' does not have any RR of the requested type", q->request_hostname);
 533                 goto finish;
 534         }
 535
 536         r = sd_bus_message_close_container(reply);
 537         if (r < 0)
 538                 goto finish;
 539
 540         r = sd_bus_send(q->manager->bus, reply, NULL);
 541
 542 finish:
 543         if (r < 0) {
 544                 log_error("Failed to send record reply: %s", strerror(-r));
 545                 sd_bus_reply_method_errno(q->request, -r, NULL);
 546         }
 547
 548         dns_query_free(q);
 549 }
 550
 551 static int bus_method_resolve_record(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
 552         _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
 553         _cleanup_(dns_question_unrefp) DnsQuestion *question = NULL;
 554         _cleanup_free_ char *reverse = NULL;
 555         Manager *m = userdata;
 556         DnsQuery *q;
 557         int r;
 558         uint16_t class, type;
 559         const char *name;
 560
 561         assert(bus);
 562         assert(message);
 563         assert(m);
 564
 565         r = sd_bus_message_read(message, "sqq", &name, &class, &type);
 566         if (r < 0)
 567                 return r;
 568
 569         question = dns_question_new(1);
 570         if (!question)
 571                 return -ENOMEM;
 572
 573         key = dns_resource_key_new(class, type, name);
 574         if (!key)
 575                 return -ENOMEM;
 576
 577         r = dns_question_add(question, key);
 578         if (r < 0)
 579                 return r;
 580
 581         r = dns_query_new(m, &q, question);
 582         if (r < 0)
 583                 return r;
 584
 585         q->request = sd_bus_message_ref(message);
 586         q->request_hostname = name;
 587         q->complete = bus_method_resolve_record_complete;
 588
 589         r = dns_query_go(q);
 590         if (r < 0) {
 591                 dns_query_free(q);
 592
 593                 if (r == -ESRCH)
 594                         sd_bus_error_setf(error, BUS_ERROR_NO_NAME_SERVERS, "No appropriate name servers or networks for name found");
 595
 596                 return r;
 597         }
 598
 599         return 1;
 600 }
 601
 602 static const sd_bus_vtable resolve_vtable[] = {
 603         SD_BUS_VTABLE_START(0),
 604         SD_BUS_METHOD("ResolveHostname", "si", "a(iayi)s", bus_method_resolve_hostname, SD_BUS_VTABLE_UNPRIVILEGED),
 605         SD_BUS_METHOD("ResolveAddress", "iayi", "as", bus_method_resolve_address, SD_BUS_VTABLE_UNPRIVILEGED),
 606         SD_BUS_METHOD("ResolveRecord", "sqq", "a(qqay)", bus_method_resolve_record, SD_BUS_VTABLE_UNPRIVILEGED),
 607         SD_BUS_VTABLE_END,
 608 };
 609
 610 static int on_bus_retry(sd_event_source *s, usec_t usec, void *userdata) {
 611         Manager *m = userdata;
 612
 613         assert(s);
 614         assert(m);
 615
 616         m->bus_retry_event_source = sd_event_source_unref(m->bus_retry_event_source);
 617
 618         manager_connect_bus(m);
 619         return 0;
 620 }
 621
 622 int manager_connect_bus(Manager *m) {
 623         int r;
 624
 625         assert(m);
 626
 627         if (m->bus)
 628                 return 0;
 629
 630         r = sd_bus_default_system(&m->bus);
 631         if (r < 0) {
 632                 /* We failed to connect? Yuck, we must be in early
 633                  * boot. Let's try in 5s again. As soon as we have
 634                  * kdbus we can stop doing this... */
 635
 636                 log_debug("Failed to connect to bus, trying again in 5s: %s", strerror(-r));
 637
 638                 r = sd_event_add_time(m->event, &m->bus_retry_event_source, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + 5*USEC_PER_SEC, 0, on_bus_retry, m);
 639                 if (r < 0) {
 640                         log_error("Failed to install bus reconnect time event: %s", strerror(-r));
 641                         return r;
 642                 }
 643
 644                 return 0;
 645         }
 646
 647         r = sd_bus_add_object_vtable(m->bus, NULL, "/org/freedesktop/resolve1", "org.freedesktop.resolve1.Manager", resolve_vtable, m);
 648         if (r < 0) {
 649                 log_error("Failed to register object: %s", strerror(-r));
 650                 return r;
 651         }
 652
 653         r = sd_bus_request_name(m->bus, "org.freedesktop.resolve1", 0);
 654         if (r < 0) {
 655                 log_error("Failed to register name: %s", strerror(-r));
 656                 return r;
 657         }
 658
 659         r = sd_bus_attach_event(m->bus, m->event, 0);
 660         if (r < 0) {
 661                 log_error("Failed to attach bus to event loop: %s", strerror(-r));
 662                 return r;
 663         }
 664
 665         return 0;
 666 }