src/resolve/resolved-manager.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <linux/ipv6.h>
   5 #include <netinet/in.h>
   6 #include <poll.h>
   7 #include <unistd.h>
   8
   9 #include "sd-bus.h"
  10 #include "sd-netlink.h"
  11 #include "sd-network.h"
  12
  13 #include "af-list.h"
  14 #include "alloc-util.h"
  15 #include "daemon-util.h"
  16 #include "dirent-util.h"
  17 #include "dns-domain.h"
  18 #include "errno-util.h"
  19 #include "event-util.h"
  20 #include "fd-util.h"
  21 #include "hostname-setup.h"
  22 #include "hostname-util.h"
  23 #include "io-util.h"
  24 #include "iovec-util.h"
  25 #include "json-util.h"
  26 #include "memstream-util.h"
  27 #include "missing-network.h"
  28 #include "ordered-set.h"
  29 #include "parse-util.h"
  30 #include "random-util.h"
  31 #include "resolved-bus.h"
  32 #include "resolved-conf.h"
  33 #include "resolved-dns-answer.h"
  34 #include "resolved-dns-delegate.h"
  35 #include "resolved-dns-packet.h"
  36 #include "resolved-dns-query.h"
  37 #include "resolved-dns-question.h"
  38 #include "resolved-dns-rr.h"
  39 #include "resolved-dns-scope.h"
  40 #include "resolved-dns-search-domain.h"
  41 #include "resolved-dns-server.h"
  42 #include "resolved-dns-stub.h"
  43 #include "resolved-dns-transaction.h"
  44 #include "resolved-dnssd.h"
  45 #include "resolved-etc-hosts.h"
  46 #include "resolved-link.h"
  47 #include "resolved-llmnr.h"
  48 #include "resolved-manager.h"
  49 #include "resolved-mdns.h"
  50 #include "resolved-resolv-conf.h"
  51 #include "resolved-socket-graveyard.h"
  52 #include "resolved-util.h"
  53 #include "resolved-varlink.h"
  54 #include "set.h"
  55 #include "socket-util.h"
  56 #include "string-util.h"
  57 #include "time-util.h"
  58 #include "varlink-util.h"
  59
  60 #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
  61
  62 static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
  63         Manager *m = ASSERT_PTR(userdata);
  64         uint16_t type;
  65         Link *l;
  66         int ifindex, r;
  67
  68         assert(rtnl);
  69         assert(mm);
  70
  71         r = sd_netlink_message_get_type(mm, &type);
  72         if (r < 0)
  73                 goto fail;
  74
  75         r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
  76         if (r < 0)
  77                 goto fail;
  78
  79         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
  80
  81         switch (type) {
  82
  83         case RTM_NEWLINK:{
  84                 bool is_new = !l;
  85
  86                 if (!l) {
  87                         r = link_new(m, &l, ifindex);
  88                         if (r < 0)
  89                                 goto fail;
  90                 }
  91
  92                 r = link_process_rtnl(l, mm);
  93                 if (r < 0)
  94                         goto fail;
  95
  96                 r = link_update(l);
  97                 if (r < 0)
  98                         goto fail;
  99
 100                 if (is_new)
 101                         log_debug("Found new link %i/%s", ifindex, l->ifname);
 102
 103                 break;
 104         }
 105
 106         case RTM_DELLINK:
 107                 if (l) {
 108                         log_debug("Removing link %i/%s", l->ifindex, l->ifname);
 109                         link_remove_user(l);
 110                         link_free(l);
 111
 112                         /* Make sure DNS servers are dropped from written resolv.conf if their link goes away */
 113                         manager_write_resolv_conf(m);
 114                 }
 115
 116                 break;
 117         }
 118
 119         /* Now check all the links, and if mDNS/llmr are disabled everywhere, stop them globally too. */
 120         manager_llmnr_maybe_stop(m);
 121         manager_mdns_maybe_stop(m);
 122
 123         /* The accessible flag on link DNS servers will have been reset by
 124          * link_update(). Just reset the global DNS servers. */
 125         (void) manager_send_dns_configuration_changed(m, NULL, /* reset= */ true);
 126
 127         return 0;
 128
 129 fail:
 130         log_warning_errno(r, "Failed to process RTNL link message: %m");
 131         return 0;
 132 }
 133
 134 static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
 135         Manager *m = ASSERT_PTR(userdata);
 136         union in_addr_union address, broadcast = {};
 137         uint16_t type;
 138         int r, ifindex, family;
 139         LinkAddress *a;
 140         Link *l;
 141
 142         assert(rtnl);
 143         assert(mm);
 144
 145         r = sd_netlink_message_get_type(mm, &type);
 146         if (r < 0)
 147                 goto fail;
 148
 149         r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
 150         if (r < 0)
 151                 goto fail;
 152
 153         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
 154         if (!l)
 155                 return 0;
 156
 157         r = sd_rtnl_message_addr_get_family(mm, &family);
 158         if (r < 0)
 159                 goto fail;
 160
 161         switch (family) {
 162
 163         case AF_INET:
 164                 sd_netlink_message_read_in_addr(mm, IFA_BROADCAST, &broadcast.in);
 165                 r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in);
 166                 if (r < 0) {
 167                         r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
 168                         if (r < 0)
 169                                 goto fail;
 170                 }
 171
 172                 break;
 173
 174         case AF_INET6:
 175                 r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
 176                 if (r < 0) {
 177                         r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
 178                         if (r < 0)
 179                                 goto fail;
 180                 }
 181
 182                 break;
 183
 184         default:
 185                 return 0;
 186         }
 187
 188         a = link_find_address(l, family, &address);
 189
 190         switch (type) {
 191
 192         case RTM_NEWADDR:
 193
 194                 if (!a) {
 195                         r = link_address_new(l, &a, family, &address, &broadcast);
 196                         if (r < 0)
 197                                 return r;
 198                 }
 199
 200                 r = link_address_update_rtnl(a, mm);
 201                 if (r < 0)
 202                         return r;
 203
 204                 break;
 205
 206         case RTM_DELADDR:
 207                 link_address_free(a);
 208                 break;
 209         }
 210
 211         (void) manager_send_dns_configuration_changed(m, l, /* reset= */ true);
 212
 213         return 0;
 214
 215 fail:
 216         log_warning_errno(r, "Failed to process RTNL address message: %m");
 217         return 0;
 218 }
 219
 220 static int manager_process_route(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
 221         Manager *m = ASSERT_PTR(userdata);
 222         Link *l = NULL;
 223         uint16_t type;
 224         uint32_t ifindex = 0;
 225         int r;
 226
 227         assert(rtnl);
 228         assert(mm);
 229
 230         r = sd_netlink_message_get_type(mm, &type);
 231         if (r < 0) {
 232                 log_warning_errno(r, "Failed to get rtnl message type, ignoring: %m");
 233                 return 0;
 234         }
 235
 236         if (!IN_SET(type, RTM_NEWROUTE, RTM_DELROUTE)) {
 237                 log_warning("Unexpected message type %u when processing route, ignoring.", type);
 238                 return 0;
 239         }
 240
 241         r = sd_netlink_message_read_u32(mm, RTA_OIF, &ifindex);
 242         if (r < 0)
 243                 log_full_errno(r == -ENODATA ? LOG_DEBUG : LOG_WARNING, r, "Failed to get route ifindex, ignoring: %m");
 244         else
 245                 l = hashmap_get(m->links, INT_TO_PTR(ifindex));
 246
 247         (void) manager_send_dns_configuration_changed(m, l, /* reset= */ true);
 248
 249         return 0;
 250 }
 251
 252 static int manager_rtnl_listen(Manager *m) {
 253         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
 254         int r;
 255
 256         assert(m);
 257
 258         /* First, subscribe to interfaces coming and going */
 259         r = sd_netlink_open(&m->rtnl);
 260         if (r < 0)
 261                 return r;
 262
 263         r = sd_netlink_attach_event(m->rtnl, m->event, SD_EVENT_PRIORITY_IMPORTANT);
 264         if (r < 0)
 265                 return r;
 266
 267         r = sd_netlink_add_match(m->rtnl, NULL, RTM_NEWLINK, manager_process_link, NULL, m, "resolve-NEWLINK");
 268         if (r < 0)
 269                 return r;
 270
 271         r = sd_netlink_add_match(m->rtnl, NULL, RTM_DELLINK, manager_process_link, NULL, m, "resolve-DELLINK");
 272         if (r < 0)
 273                 return r;
 274
 275         r = sd_netlink_add_match(m->rtnl, NULL, RTM_NEWADDR, manager_process_address, NULL, m, "resolve-NEWADDR");
 276         if (r < 0)
 277                 return r;
 278
 279         r = sd_netlink_add_match(m->rtnl, NULL, RTM_DELADDR, manager_process_address, NULL, m, "resolve-DELADDR");
 280         if (r < 0)
 281                 return r;
 282
 283         /* Then, enumerate all links */
 284         r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
 285         if (r < 0)
 286                 return r;
 287
 288         r = sd_netlink_message_set_request_dump(req, true);
 289         if (r < 0)
 290                 return r;
 291
 292         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 293         if (r < 0)
 294                 return r;
 295
 296         for (sd_netlink_message *i = reply; i; i = sd_netlink_message_next(i)) {
 297                 r = manager_process_link(m->rtnl, i, m);
 298                 if (r < 0)
 299                         return r;
 300         }
 301
 302         req = sd_netlink_message_unref(req);
 303         reply = sd_netlink_message_unref(reply);
 304
 305         /* Finally, enumerate all addresses, too */
 306         r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
 307         if (r < 0)
 308                 return r;
 309
 310         r = sd_netlink_message_set_request_dump(req, true);
 311         if (r < 0)
 312                 return r;
 313
 314         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 315         if (r < 0)
 316                 return r;
 317
 318         for (sd_netlink_message *i = reply; i; i = sd_netlink_message_next(i)) {
 319                 r = manager_process_address(m->rtnl, i, m);
 320                 if (r < 0)
 321                         return r;
 322         }
 323
 324         return r;
 325 }
 326
 327 static int on_network_event(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
 328         Manager *m = ASSERT_PTR(userdata);
 329         Link *l;
 330         int r;
 331
 332         sd_network_monitor_flush(m->network_monitor);
 333
 334         HASHMAP_FOREACH(l, m->links) {
 335                 r = link_update(l);
 336                 if (r < 0)
 337                         log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
 338         }
 339
 340         (void) manager_write_resolv_conf(m);
 341         (void) manager_send_changed(m, "DNS");
 342         (void) manager_send_dns_configuration_changed(m, NULL, /* reset= */ true);
 343
 344         /* Now check all the links, and if mDNS/llmr are disabled everywhere, stop them globally too. */
 345         manager_llmnr_maybe_stop(m);
 346         manager_mdns_maybe_stop(m);
 347         return 0;
 348 }
 349
 350 static int manager_network_monitor_listen(Manager *m) {
 351         int r, fd, events;
 352
 353         assert(m);
 354
 355         r = sd_network_monitor_new(&m->network_monitor, NULL);
 356         if (r < 0)
 357                 return r;
 358
 359         fd = sd_network_monitor_get_fd(m->network_monitor);
 360         if (fd < 0)
 361                 return fd;
 362
 363         events = sd_network_monitor_get_events(m->network_monitor);
 364         if (events < 0)
 365                 return events;
 366
 367         r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m);
 368         if (r < 0)
 369                 return r;
 370
 371         r = sd_event_source_set_priority(m->network_event_source, SD_EVENT_PRIORITY_IMPORTANT+5);
 372         if (r < 0)
 373                 return r;
 374
 375         (void) sd_event_source_set_description(m->network_event_source, "network-monitor");
 376
 377         return 0;
 378 }
 379
 380 static int manager_clock_change_listen(Manager *m);
 381
 382 static int on_clock_change(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
 383         Manager *m = ASSERT_PTR(userdata);
 384
 385         /* The clock has changed, let's flush all caches. Why that? That's because DNSSEC validation takes
 386          * the system clock into consideration, and if the clock changes the old validations might have been
 387          * wrong. Let's redo all validation with the new, correct time.
 388          *
 389          * (Also, this is triggered after system suspend, which is also a good reason to drop caches, since
 390          * we might be connected to a different network now without this being visible in a dropped link
 391          * carrier or so.) */
 392
 393         log_info("Clock change detected. Flushing caches.");
 394         manager_flush_caches(m, LOG_DEBUG /* downgrade the functions own log message, since we already logged here at LOG_INFO level */);
 395
 396         /* The clock change timerfd is unusable after it triggered once, create a new one. */
 397         return manager_clock_change_listen(m);
 398 }
 399
 400 static int manager_clock_change_listen(Manager *m) {
 401         int r;
 402
 403         assert(m);
 404
 405         m->clock_change_event_source = sd_event_source_disable_unref(m->clock_change_event_source);
 406
 407         r = event_add_time_change(m->event, &m->clock_change_event_source, on_clock_change, m);
 408         if (r < 0)
 409                 return log_error_errno(r, "Failed to create clock change event source: %m");
 410
 411         return 0;
 412 }
 413
 414 static int determine_hostnames(char **full_hostname, char **llmnr_hostname, char **mdns_hostname) {
 415         _cleanup_free_ char *h = NULL, *n = NULL;
 416         int r;
 417
 418         assert(full_hostname);
 419         assert(llmnr_hostname);
 420         assert(mdns_hostname);
 421
 422         r = resolve_system_hostname(&h, &n);
 423         if (r < 0)
 424                 return r;
 425
 426         r = dns_name_concat(n, "local", 0, mdns_hostname);
 427         if (r < 0)
 428                 return log_error_errno(r, "Failed to determine mDNS hostname: %m");
 429
 430         *llmnr_hostname = TAKE_PTR(n);
 431         *full_hostname = TAKE_PTR(h);
 432
 433         return 0;
 434 }
 435
 436 static char* fallback_hostname(void) {
 437
 438         /* Determine the fall back hostname. For exposing this system to the outside world, we cannot have it
 439          * to be "localhost" even if that's the default hostname. In this case, let's revert to "linux"
 440          * instead. */
 441
 442         _cleanup_free_ char *n = get_default_hostname();
 443         if (!n)
 444                 return NULL;
 445
 446         if (is_localhost(n))
 447                 return strdup("linux");
 448
 449         return TAKE_PTR(n);
 450 }
 451
 452 static int make_fallback_hostnames(char **full_hostname, char **llmnr_hostname, char **mdns_hostname) {
 453         _cleanup_free_ char *h = NULL, *n = NULL, *m = NULL;
 454         char label[DNS_LABEL_MAX+1];
 455         const char *p;
 456         int r;
 457
 458         assert(full_hostname);
 459         assert(llmnr_hostname);
 460         assert(mdns_hostname);
 461
 462         p = h = fallback_hostname();
 463         if (!h)
 464                 return log_oom();
 465
 466         r = dns_label_unescape(&p, label, sizeof label, 0);
 467         if (r < 0)
 468                 return log_error_errno(r, "Failed to unescape fallback hostname: %m");
 469
 470         assert(r > 0); /* The fallback hostname must have at least one label */
 471
 472         r = dns_label_escape_new(label, r, &n);
 473         if (r < 0)
 474                 return log_error_errno(r, "Failed to escape fallback hostname: %m");
 475
 476         r = dns_name_concat(n, "local", 0, &m);
 477         if (r < 0)
 478                 return log_error_errno(r, "Failed to concatenate mDNS hostname: %m");
 479
 480         *llmnr_hostname = TAKE_PTR(n);
 481         *mdns_hostname = TAKE_PTR(m);
 482         *full_hostname = TAKE_PTR(h);
 483
 484         return 0;
 485 }
 486
 487 static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
 488         _cleanup_free_ char *full_hostname = NULL, *llmnr_hostname = NULL, *mdns_hostname = NULL;
 489         Manager *m = ASSERT_PTR(userdata);
 490         bool llmnr_hostname_changed;
 491         int r;
 492
 493         r = determine_hostnames(&full_hostname, &llmnr_hostname, &mdns_hostname);
 494         if (r < 0) {
 495                 log_warning_errno(r, "Failed to determine the local hostname and LLMNR/mDNS names, ignoring: %m");
 496                 return 0; /* ignore invalid hostnames */
 497         }
 498
 499         llmnr_hostname_changed = !streq(llmnr_hostname, m->llmnr_hostname);
 500         if (streq(full_hostname, m->full_hostname) &&
 501             !llmnr_hostname_changed &&
 502             streq(mdns_hostname, m->mdns_hostname))
 503                 return 0;
 504
 505         log_info("System hostname changed to '%s'.", full_hostname);
 506
 507         free_and_replace(m->full_hostname, full_hostname);
 508         free_and_replace(m->llmnr_hostname, llmnr_hostname);
 509         free_and_replace(m->mdns_hostname, mdns_hostname);
 510
 511         manager_refresh_rrs(m);
 512         (void) manager_send_changed(m, "LLMNRHostname");
 513
 514         return 0;
 515 }
 516
 517 static int manager_watch_hostname(Manager *m) {
 518         int r;
 519
 520         assert(m);
 521
 522         m->hostname_fd = open("/proc/sys/kernel/hostname",
 523                               O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
 524         if (m->hostname_fd < 0) {
 525                 log_warning_errno(errno, "Failed to watch hostname: %m");
 526                 return 0;
 527         }
 528
 529         r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
 530         if (r < 0)
 531                 return log_error_errno(r, "Failed to add hostname event source: %m");
 532
 533         (void) sd_event_source_set_description(m->hostname_event_source, "hostname");
 534
 535         r = determine_hostnames(&m->full_hostname, &m->llmnr_hostname, &m->mdns_hostname);
 536         if (r < 0) {
 537                 _cleanup_free_ char *d = NULL;
 538
 539                 d = fallback_hostname();
 540                 if (!d)
 541                         return log_oom();
 542
 543                 log_info("Defaulting to hostname '%s'.", d);
 544
 545                 r = make_fallback_hostnames(&m->full_hostname, &m->llmnr_hostname, &m->mdns_hostname);
 546                 if (r < 0)
 547                         return r;
 548         } else
 549                 log_info("Using system hostname '%s'.", m->full_hostname);
 550
 551         return 0;
 552 }
 553
 554 static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 555         _cleanup_(memstream_done) MemStream ms = {};
 556         Manager *m = ASSERT_PTR(userdata);
 557         Link *l;
 558         FILE *f;
 559
 560         assert(s);
 561         assert(si);
 562
 563         f = memstream_init(&ms);
 564         if (!f)
 565                 return log_oom();
 566
 567         LIST_FOREACH(scopes, scope, m->dns_scopes)
 568                 dns_scope_dump(scope, f);
 569
 570         LIST_FOREACH(servers, server, m->dns_servers)
 571                 dns_server_dump(server, f);
 572         LIST_FOREACH(servers, server, m->fallback_dns_servers)
 573                 dns_server_dump(server, f);
 574         HASHMAP_FOREACH(l, m->links)
 575                 LIST_FOREACH(servers, server, l->dns_servers)
 576                         dns_server_dump(server, f);
 577         DnsDelegate *delegate;
 578         HASHMAP_FOREACH(delegate, m->delegates)
 579                 LIST_FOREACH(servers, server, delegate->dns_servers)
 580                         dns_server_dump(server, f);
 581
 582         return memstream_dump(LOG_INFO, &ms);
 583 }
 584
 585 static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 586         Manager *m = ASSERT_PTR(userdata);
 587
 588         assert(s);
 589         assert(si);
 590
 591         manager_flush_caches(m, LOG_INFO);
 592
 593         return 0;
 594 }
 595
 596 static int manager_sigrtmin1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 597         Manager *m = ASSERT_PTR(userdata);
 598
 599         assert(s);
 600         assert(si);
 601
 602         manager_reset_server_features(m);
 603         return 0;
 604 }
 605
 606 static int manager_memory_pressure(sd_event_source *s, void *userdata) {
 607         Manager *m = ASSERT_PTR(userdata);
 608
 609         log_info("Under memory pressure, flushing caches.");
 610
 611         manager_flush_caches(m, LOG_INFO);
 612         sd_event_trim_memory();
 613
 614         return 0;
 615 }
 616
 617 static int manager_memory_pressure_listen(Manager *m) {
 618         int r;
 619
 620         assert(m);
 621
 622         r = sd_event_add_memory_pressure(m->event, NULL, manager_memory_pressure, m);
 623         if (r < 0)
 624                 log_full_errno(ERRNO_IS_NOT_SUPPORTED(r) || ERRNO_IS_PRIVILEGE(r) || (r == -EHOSTDOWN )? LOG_DEBUG : LOG_NOTICE, r,
 625                                "Failed to install memory pressure event source, ignoring: %m");
 626
 627         return 0;
 628 }
 629
 630 static void manager_set_defaults(Manager *m) {
 631         assert(m);
 632
 633         m->llmnr_support = DEFAULT_LLMNR_MODE;
 634         m->mdns_support = DEFAULT_MDNS_MODE;
 635         m->dnssec_mode = DEFAULT_DNSSEC_MODE;
 636         m->dns_over_tls_mode = DEFAULT_DNS_OVER_TLS_MODE;
 637         m->enable_cache = DNS_CACHE_MODE_YES;
 638         m->dns_stub_listener_mode = DNS_STUB_LISTENER_YES;
 639         m->read_etc_hosts = true;
 640         m->resolve_unicast_single_label = false;
 641         m->cache_from_localhost = false;
 642         m->stale_retention_usec = 0;
 643         m->refuse_record_types = set_free(m->refuse_record_types);
 644 }
 645
 646 static int manager_dispatch_reload_signal(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 647         Manager *m = ASSERT_PTR(userdata);
 648         Link *l;
 649         int r;
 650
 651         (void) notify_reloading();
 652
 653         dns_server_unlink_on_reload(m->dns_servers);
 654         dns_server_unlink_on_reload(m->fallback_dns_servers);
 655         m->dns_extra_stub_listeners = ordered_set_free(m->dns_extra_stub_listeners);
 656         manager_dns_stub_stop(m);
 657         dnssd_registered_service_clear_on_reload(m->dnssd_registered_services);
 658         m->unicast_scope = dns_scope_free(m->unicast_scope);
 659         m->delegates = hashmap_free(m->delegates);
 660         dns_trust_anchor_flush(&m->trust_anchor);
 661
 662         manager_set_defaults(m);
 663
 664         r = dns_trust_anchor_load(&m->trust_anchor);
 665         if (r < 0)
 666                 return sd_event_exit(sd_event_source_get_event(s), r);
 667
 668         r = manager_parse_config_file(m);
 669         if (r < 0)
 670                 log_warning_errno(r, "Failed to parse configuration file on reload, ignoring: %m");
 671         else
 672                 log_info("Config file reloaded.");
 673
 674         (void) dnssd_load(m);
 675         (void) manager_load_delegates(m);
 676
 677         /* The default scope configuration is influenced by the manager's configuration (modes, etc.), so
 678          * recreate it on reload. */
 679         r = dns_scope_new(m, &m->unicast_scope, DNS_SCOPE_GLOBAL, /* link= */ NULL, /* delegate= */ NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 680         if (r < 0)
 681                 return sd_event_exit(sd_event_source_get_event(s), r);
 682
 683         /* A link's unicast scope may also be influenced by the manager's configuration. I.e., DNSSEC= and DNSOverTLS=
 684          * from the manager will be used if not explicitly configured on the link. Free the scopes here so that
 685          * link_allocate_scopes() in on_network_event() re-creates them. */
 686         HASHMAP_FOREACH(l, m->links)
 687                 l->unicast_scope = dns_scope_free(l->unicast_scope);
 688
 689         /* The configuration has changed, so reload the per-interface configuration too in order to take
 690          * into account any changes (e.g.: enable/disable DNSSEC). */
 691         r = on_network_event(/* source= */ NULL, -EBADF, /* revents= */ 0, m);
 692         if (r < 0)
 693                 log_warning_errno(r, "Failed to update network information on reload, ignoring: %m");
 694
 695         /* We have new configuration, which means potentially new servers, so close all connections and drop
 696          * all caches, so that we can start fresh. */
 697         (void) dns_stream_disconnect_all(m);
 698         manager_flush_caches(m, LOG_INFO);
 699         manager_verify_all(m);
 700
 701         r = manager_dns_stub_start(m);
 702         if (r < 0)
 703                 return sd_event_exit(sd_event_source_get_event(s), r);
 704
 705         (void) sd_notify(/* unset_environment= */ false, NOTIFY_READY_MESSAGE);
 706         return 0;
 707 }
 708
 709 int manager_new(Manager **ret) {
 710         _cleanup_(manager_freep) Manager *m = NULL;
 711         int r;
 712
 713         assert(ret);
 714
 715         m = new(Manager, 1);
 716         if (!m)
 717                 return -ENOMEM;
 718
 719         *m = (Manager) {
 720                 .llmnr_ipv4_udp_fd = -EBADF,
 721                 .llmnr_ipv6_udp_fd = -EBADF,
 722                 .llmnr_ipv4_tcp_fd = -EBADF,
 723                 .llmnr_ipv6_tcp_fd = -EBADF,
 724                 .mdns_ipv4_fd = -EBADF,
 725                 .mdns_ipv6_fd = -EBADF,
 726                 .hostname_fd = -EBADF,
 727
 728                 .read_resolv_conf = true,
 729                 .need_builtin_fallbacks = true,
 730                 .etc_hosts_last = USEC_INFINITY,
 731
 732                 .sigrtmin18_info.memory_pressure_handler = manager_memory_pressure,
 733                 .sigrtmin18_info.memory_pressure_userdata = m,
 734         };
 735
 736         manager_set_defaults(m);
 737
 738         r = dns_trust_anchor_load(&m->trust_anchor);
 739         if (r < 0)
 740                 return r;
 741
 742         r = manager_parse_config_file(m);
 743         if (r < 0)
 744                 log_warning_errno(r, "Failed to parse configuration file, ignoring: %m");
 745
 746 #if ENABLE_DNS_OVER_TLS
 747         r = dnstls_manager_init(m);
 748         if (r < 0)
 749                 return r;
 750 #endif
 751
 752         r = sd_event_default(&m->event);
 753         if (r < 0)
 754                 return r;
 755
 756         r = sd_event_set_signal_exit(m->event, true);
 757         if (r < 0)
 758                 return r;
 759
 760         (void) sd_event_set_watchdog(m->event, true);
 761
 762         r = manager_watch_hostname(m);
 763         if (r < 0)
 764                 return r;
 765
 766         (void) dnssd_load(m);
 767         (void) manager_load_delegates(m);
 768
 769         r = dns_scope_new(m, &m->unicast_scope, DNS_SCOPE_GLOBAL, /* link= */ NULL, /* delegate= */ NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 770         if (r < 0)
 771                 return r;
 772
 773         r = manager_network_monitor_listen(m);
 774         if (r < 0)
 775                 return r;
 776
 777         r = manager_rtnl_listen(m);
 778         if (r < 0)
 779                 return r;
 780
 781         r = manager_clock_change_listen(m);
 782         if (r < 0)
 783                 return r;
 784
 785         r = manager_memory_pressure_listen(m);
 786         if (r < 0)
 787                 return r;
 788
 789         r = manager_connect_bus(m);
 790         if (r < 0)
 791                 return r;
 792
 793         r = sd_event_add_signal(m->event, /* ret= */ NULL, SIGHUP | SD_EVENT_SIGNAL_PROCMASK, manager_dispatch_reload_signal, m);
 794         if (r < 0)
 795                 return log_debug_errno(r, "Failed to install SIGHUP handler: %m");
 796
 797         r = sd_event_add_signal(m->event, /* ret= */ NULL, SIGUSR1 | SD_EVENT_SIGNAL_PROCMASK, manager_sigusr1, m);
 798         if (r < 0)
 799                 return log_debug_errno(r, "Failed to install SIGUSR1 handler: %m");
 800
 801         r = sd_event_add_signal(m->event, /* ret= */ NULL, SIGUSR2 | SD_EVENT_SIGNAL_PROCMASK, manager_sigusr2, m);
 802         if (r < 0)
 803                 return log_debug_errno(r, "Failed to install SIGUSR2 handler: %m");
 804
 805         r = sd_event_add_signal(m->event, /* ret= */ NULL, (SIGRTMIN+1) | SD_EVENT_SIGNAL_PROCMASK, manager_sigrtmin1, m);
 806         if (r < 0)
 807                 return log_debug_errno(r, "Failed to install SIGRTMIN+1 handler: %m");
 808
 809         r = sd_event_add_signal(m->event, /* ret= */ NULL, (SIGRTMIN+18) | SD_EVENT_SIGNAL_PROCMASK, sigrtmin18_handler, &m->sigrtmin18_info);
 810         if (r < 0)
 811                 return log_debug_errno(r, "Failed to install SIGRTMIN+18 handler: %m");
 812
 813         manager_cleanup_saved_user(m);
 814
 815         *ret = TAKE_PTR(m);
 816
 817         return 0;
 818 }
 819
 820 int manager_start(Manager *m) {
 821         int r;
 822
 823         assert(m);
 824
 825         r = manager_dns_stub_start(m);
 826         if (r < 0)
 827                 return r;
 828
 829         r = manager_varlink_init(m);
 830         if (r < 0)
 831                 return r;
 832
 833         return 0;
 834 }
 835
 836 Manager* manager_free(Manager *m) {
 837         Link *l;
 838         DnssdRegisteredService *s;
 839         DnsServiceBrowser *sb;
 840
 841         if (!m)
 842                 return NULL;
 843
 844         dns_server_unlink_all(m->dns_servers);
 845         dns_server_unlink_all(m->fallback_dns_servers);
 846         dns_search_domain_unlink_all(m->search_domains);
 847
 848         while ((l = hashmap_first(m->links)))
 849                link_free(l);
 850
 851         m->delegates = hashmap_free(m->delegates);
 852
 853         while (m->dns_queries)
 854                 dns_query_free(m->dns_queries);
 855
 856         m->stub_queries_by_packet = hashmap_free(m->stub_queries_by_packet);
 857         m->unicast_scope = dns_scope_free(m->unicast_scope);
 858
 859         /* At this point only orphaned streams should remain. All others should have been freed already by their
 860          * owners */
 861         while (m->dns_streams)
 862                 dns_stream_unref(m->dns_streams);
 863
 864 #if ENABLE_DNS_OVER_TLS
 865         dnstls_manager_free(m);
 866 #endif
 867
 868         set_free(m->refuse_record_types);
 869         hashmap_free(m->links);
 870         hashmap_free(m->dns_transactions);
 871
 872         sd_event_source_unref(m->network_event_source);
 873         sd_network_monitor_unref(m->network_monitor);
 874
 875         sd_netlink_slot_unref(m->netlink_new_route_slot);
 876         sd_netlink_slot_unref(m->netlink_del_route_slot);
 877         sd_netlink_unref(m->rtnl);
 878         sd_event_source_unref(m->rtnl_event_source);
 879         sd_event_source_unref(m->clock_change_event_source);
 880
 881         sd_json_variant_unref(m->dns_configuration_json);
 882
 883         manager_llmnr_stop(m);
 884         manager_mdns_stop(m);
 885         manager_dns_stub_stop(m);
 886         manager_varlink_done(m);
 887
 888         manager_socket_graveyard_clear(m);
 889
 890         ordered_set_free(m->dns_extra_stub_listeners);
 891
 892         hashmap_free(m->polkit_registry);
 893
 894         sd_bus_flush_close_unref(m->bus);
 895
 896         dns_resource_key_unref(m->llmnr_host_ipv4_key);
 897         dns_resource_key_unref(m->llmnr_host_ipv6_key);
 898         dns_resource_key_unref(m->mdns_host_ipv4_key);
 899         dns_resource_key_unref(m->mdns_host_ipv6_key);
 900
 901         sd_event_source_unref(m->hostname_event_source);
 902         safe_close(m->hostname_fd);
 903
 904         sd_event_unref(m->event);
 905
 906         free(m->full_hostname);
 907         free(m->llmnr_hostname);
 908         free(m->mdns_hostname);
 909
 910         while ((s = hashmap_first(m->dnssd_registered_services)))
 911                dnssd_registered_service_free(s);
 912         hashmap_free(m->dnssd_registered_services);
 913
 914         dns_trust_anchor_flush(&m->trust_anchor);
 915         manager_etc_hosts_flush(m);
 916
 917         while ((sb = hashmap_first(m->dns_service_browsers)))
 918                 dns_service_browser_free(sb);
 919         hashmap_free(m->dns_service_browsers);
 920
 921         return mfree(m);
 922 }
 923
 924 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 925         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 926         CMSG_BUFFER_TYPE(CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 927                          + CMSG_SPACE(int) /* ttl/hoplimit */
 928                          + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */) control;
 929         union sockaddr_union sa;
 930         struct iovec iov;
 931         struct msghdr mh = {
 932                 .msg_name = &sa.sa,
 933                 .msg_namelen = sizeof(sa),
 934                 .msg_iov = &iov,
 935                 .msg_iovlen = 1,
 936                 .msg_control = &control,
 937                 .msg_controllen = sizeof(control),
 938         };
 939         struct cmsghdr *cmsg;
 940         ssize_t ms, l;
 941         int r;
 942
 943         assert(m);
 944         assert(fd >= 0);
 945         assert(ret);
 946
 947         ms = next_datagram_size_fd(fd);
 948         if (ms < 0)
 949                 return ms;
 950
 951         r = dns_packet_new(&p, protocol, ms, DNS_PACKET_SIZE_MAX);
 952         if (r < 0)
 953                 return r;
 954
 955         iov = IOVEC_MAKE(DNS_PACKET_DATA(p), p->allocated);
 956
 957         l = recvmsg_safe(fd, &mh, 0);
 958         if (ERRNO_IS_NEG_TRANSIENT(l))
 959                 return 0;
 960         if (l <= 0)
 961                 return l;
 962
 963         p->size = (size_t) l;
 964
 965         p->family = sa.sa.sa_family;
 966         p->ipproto = IPPROTO_UDP;
 967         if (p->family == AF_INET) {
 968                 p->sender.in = sa.in.sin_addr;
 969                 p->sender_port = be16toh(sa.in.sin_port);
 970         } else if (p->family == AF_INET6) {
 971                 p->sender.in6 = sa.in6.sin6_addr;
 972                 p->sender_port = be16toh(sa.in6.sin6_port);
 973                 p->ifindex = sa.in6.sin6_scope_id;
 974         } else
 975                 return -EAFNOSUPPORT;
 976
 977         p->timestamp = now(CLOCK_BOOTTIME);
 978
 979         CMSG_FOREACH(cmsg, &mh) {
 980
 981                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 982                         assert(p->family == AF_INET6);
 983
 984                         switch (cmsg->cmsg_type) {
 985
 986                         case IPV6_PKTINFO: {
 987                                 struct in6_pktinfo *i = CMSG_TYPED_DATA(cmsg, struct in6_pktinfo);
 988
 989                                 if (p->ifindex <= 0)
 990                                         p->ifindex = i->ipi6_ifindex;
 991
 992                                 p->destination.in6 = i->ipi6_addr;
 993                                 break;
 994                         }
 995
 996                         case IPV6_HOPLIMIT:
 997                                 p->ttl = *CMSG_TYPED_DATA(cmsg, int);
 998                                 break;
 999
1000                         case IPV6_RECVFRAGSIZE:
1001                                 p->fragsize = *CMSG_TYPED_DATA(cmsg, int);
1002                                 break;
1003                         }
1004                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
1005                         assert(p->family == AF_INET);
1006
1007                         switch (cmsg->cmsg_type) {
1008
1009                         case IP_PKTINFO: {
1010                                 struct in_pktinfo *i = CMSG_TYPED_DATA(cmsg, struct in_pktinfo);
1011
1012                                 if (p->ifindex <= 0)
1013                                         p->ifindex = i->ipi_ifindex;
1014
1015                                 p->destination.in = i->ipi_addr;
1016                                 break;
1017                         }
1018
1019                         case IP_TTL:
1020                                 p->ttl = *CMSG_TYPED_DATA(cmsg, int);
1021                                 break;
1022
1023                         case IP_RECVFRAGSIZE:
1024                                 p->fragsize = *CMSG_TYPED_DATA(cmsg, int);
1025                                 break;
1026                         }
1027                 }
1028         }
1029
1030         /* The Linux kernel sets the interface index to the loopback
1031          * device if the packet came from the local host since it
1032          * avoids the routing table in such a case. Let's unset the
1033          * interface index in such a case. */
1034         if (p->ifindex == LOOPBACK_IFINDEX)
1035                 p->ifindex = 0;
1036
1037         if (protocol != DNS_PROTOCOL_DNS) {
1038                 /* If we don't know the interface index still, we look for the
1039                  * first local interface with a matching address. Yuck! */
1040                 if (p->ifindex <= 0)
1041                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
1042         }
1043
1044         log_debug("Received %s UDP packet of size %zu, ifindex=%i, ttl=%u, fragsize=%zu, sender=%s, destination=%s",
1045                   dns_protocol_to_string(protocol), p->size, p->ifindex, p->ttl, p->fragsize,
1046                   IN_ADDR_TO_STRING(p->family, &p->sender),
1047                   IN_ADDR_TO_STRING(p->family, &p->destination));
1048
1049         *ret = TAKE_PTR(p);
1050         return 1;
1051 }
1052
1053 int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
1054         usec_t end;
1055         int r;
1056
1057         assert(fd >= 0);
1058         assert(mh);
1059
1060         end = usec_add(now(CLOCK_MONOTONIC), SEND_TIMEOUT_USEC);
1061
1062         for (;;) {
1063                 if (sendmsg(fd, mh, flags) >= 0)
1064                         return 0;
1065                 if (errno == EINTR)
1066                         continue;
1067                 if (errno != EAGAIN)
1068                         return -errno;
1069
1070                 r = fd_wait_for_event(fd, POLLOUT, LESS_BY(end, now(CLOCK_MONOTONIC)));
1071                 if (ERRNO_IS_NEG_TRANSIENT(r))
1072                         continue;
1073                 if (r < 0)
1074                         return r;
1075                 if (r == 0)
1076                         return -ETIMEDOUT;
1077         }
1078 }
1079
1080 static int write_loop(int fd, void *message, size_t length) {
1081         usec_t end;
1082         int r;
1083
1084         assert(fd >= 0);
1085         assert(message);
1086
1087         end = usec_add(now(CLOCK_MONOTONIC), SEND_TIMEOUT_USEC);
1088
1089         for (;;) {
1090                 if (write(fd, message, length) >= 0)
1091                         return 0;
1092                 if (errno == EINTR)
1093                         continue;
1094                 if (errno != EAGAIN)
1095                         return -errno;
1096
1097                 r = fd_wait_for_event(fd, POLLOUT, LESS_BY(end, now(CLOCK_MONOTONIC)));
1098                 if (ERRNO_IS_NEG_TRANSIENT(r))
1099                         continue;
1100                 if (r < 0)
1101                         return r;
1102                 if (r == 0)
1103                         return -ETIMEDOUT;
1104         }
1105 }
1106
1107 int manager_write(Manager *m, int fd, DnsPacket *p) {
1108         int r;
1109
1110         log_debug("Sending %s%s packet with id %" PRIu16 " of size %zu.",
1111                   DNS_PACKET_TC(p) ? "truncated (!) " : "",
1112                   DNS_PACKET_QR(p) ? "response" : "query",
1113                   DNS_PACKET_ID(p),
1114                   p->size);
1115
1116         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
1117         if (r < 0)
1118                 return r;
1119
1120         return 0;
1121 }
1122
1123 static int manager_ipv4_send(
1124                 Manager *m,
1125                 int fd,
1126                 int ifindex,
1127                 const struct in_addr *destination,
1128                 uint16_t port,
1129                 const struct in_addr *source,
1130                 DnsPacket *p) {
1131
1132         CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct in_pktinfo))) control = {};
1133         union sockaddr_union sa;
1134         struct iovec iov;
1135         struct msghdr mh = {
1136                 .msg_iov = &iov,
1137                 .msg_iovlen = 1,
1138                 .msg_name = &sa.sa,
1139                 .msg_namelen = sizeof(sa.in),
1140         };
1141
1142         assert(m);
1143         assert(fd >= 0);
1144         assert(destination);
1145         assert(port > 0);
1146         assert(p);
1147
1148         iov = IOVEC_MAKE(DNS_PACKET_DATA(p), p->size);
1149
1150         sa = (union sockaddr_union) {
1151                 .in.sin_family = AF_INET,
1152                 .in.sin_addr = *destination,
1153                 .in.sin_port = htobe16(port),
1154         };
1155
1156         if (ifindex > 0) {
1157                 struct cmsghdr *cmsg;
1158                 struct in_pktinfo *pi;
1159
1160                 mh.msg_control = &control;
1161                 mh.msg_controllen = sizeof(control);
1162
1163                 cmsg = CMSG_FIRSTHDR(&mh);
1164                 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
1165                 cmsg->cmsg_level = IPPROTO_IP;
1166                 cmsg->cmsg_type = IP_PKTINFO;
1167
1168                 pi = CMSG_TYPED_DATA(cmsg, struct in_pktinfo);
1169                 pi->ipi_ifindex = ifindex;
1170
1171                 if (source)
1172                         pi->ipi_spec_dst = *source;
1173         }
1174
1175         return sendmsg_loop(fd, &mh, 0);
1176 }
1177
1178 static int manager_ipv6_send(
1179                 Manager *m,
1180                 int fd,
1181                 int ifindex,
1182                 const struct in6_addr *destination,
1183                 uint16_t port,
1184                 const struct in6_addr *source,
1185                 DnsPacket *p) {
1186
1187         CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct in6_pktinfo))) control = {};
1188         union sockaddr_union sa;
1189         struct iovec iov;
1190         struct msghdr mh = {
1191                 .msg_iov = &iov,
1192                 .msg_iovlen = 1,
1193                 .msg_name = &sa.sa,
1194                 .msg_namelen = sizeof(sa.in6),
1195         };
1196
1197         assert(m);
1198         assert(fd >= 0);
1199         assert(destination);
1200         assert(port > 0);
1201         assert(p);
1202
1203         iov = IOVEC_MAKE(DNS_PACKET_DATA(p), p->size);
1204
1205         sa = (union sockaddr_union) {
1206                 .in6.sin6_family = AF_INET6,
1207                 .in6.sin6_addr = *destination,
1208                 .in6.sin6_port = htobe16(port),
1209                 .in6.sin6_scope_id = ifindex,
1210         };
1211
1212         if (ifindex > 0) {
1213                 struct cmsghdr *cmsg;
1214                 struct in6_pktinfo *pi;
1215
1216                 mh.msg_control = &control;
1217                 mh.msg_controllen = sizeof(control);
1218
1219                 cmsg = CMSG_FIRSTHDR(&mh);
1220                 cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
1221                 cmsg->cmsg_level = IPPROTO_IPV6;
1222                 cmsg->cmsg_type = IPV6_PKTINFO;
1223
1224                 pi = CMSG_TYPED_DATA(cmsg, struct in6_pktinfo);
1225                 pi->ipi6_ifindex = ifindex;
1226
1227                 if (source)
1228                         pi->ipi6_addr = *source;
1229         }
1230
1231         return sendmsg_loop(fd, &mh, 0);
1232 }
1233
1234 static int dns_question_to_json(DnsQuestion *q, sd_json_variant **ret) {
1235         _cleanup_(sd_json_variant_unrefp) sd_json_variant *l = NULL;
1236         DnsResourceKey *key;
1237         int r;
1238
1239         assert(ret);
1240
1241         DNS_QUESTION_FOREACH(key, q) {
1242                 _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL;
1243
1244                 r = dns_resource_key_to_json(key, &v);
1245                 if (r < 0)
1246                         return r;
1247
1248                 r = sd_json_variant_append_array(&l, v);
1249                 if (r < 0)
1250                         return r;
1251         }
1252
1253         *ret = TAKE_PTR(l);
1254         return 0;
1255 }
1256
1257 int manager_monitor_send(Manager *m, DnsQuery *q) {
1258         _cleanup_(sd_json_variant_unrefp) sd_json_variant *jquestion = NULL, *jcollected_questions = NULL, *janswer = NULL;
1259         _cleanup_(dns_question_unrefp) DnsQuestion *merged = NULL;
1260         DnsAnswerItem *rri;
1261         int r;
1262
1263         assert(m);
1264
1265         if (set_isempty(m->varlink_query_results_subscription))
1266                 return 0;
1267
1268         /* Merge all questions into one */
1269         r = dns_question_merge(q->question_idna, q->question_utf8, &merged);
1270         if (r < 0)
1271                 return log_error_errno(r, "Failed to merge UTF8/IDNA questions: %m");
1272
1273         if (q->question_bypass) {
1274                 _cleanup_(dns_question_unrefp) DnsQuestion *merged2 = NULL;
1275
1276                 r = dns_question_merge(merged, q->question_bypass->question, &merged2);
1277                 if (r < 0)
1278                         return log_error_errno(r, "Failed to merge UTF8/IDNA questions and DNS packet question: %m");
1279
1280                 dns_question_unref(merged);
1281                 merged = TAKE_PTR(merged2);
1282         }
1283
1284         /* Convert the current primary question to JSON */
1285         r = dns_question_to_json(merged, &jquestion);
1286         if (r < 0)
1287                 return log_error_errno(r, "Failed to convert question to JSON: %m");
1288
1289         /* Generate a JSON array of the questions preceding the current one in the CNAME chain */
1290         r = dns_question_to_json(q->collected_questions, &jcollected_questions);
1291         if (r < 0)
1292                 return log_error_errno(r, "Failed to convert question to JSON: %m");
1293
1294         DNS_ANSWER_FOREACH_ITEM(rri, q->answer) {
1295                 _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL;
1296
1297                 r = dns_resource_record_to_json(rri->rr, &v);
1298                 if (r < 0)
1299                         return log_error_errno(r, "Failed to convert answer resource record to JSON: %m");
1300
1301                 r = dns_resource_record_to_wire_format(rri->rr, /* canonical= */ false); /* don't use DNSSEC canonical format, since it removes casing, but we want that for DNS_SD compat */
1302                 if (r < 0)
1303                         return log_error_errno(r, "Failed to generate RR wire format: %m");
1304
1305                 r = sd_json_variant_append_arraybo(
1306                                 &janswer,
1307                                 SD_JSON_BUILD_PAIR_CONDITION(!!v, "rr", SD_JSON_BUILD_VARIANT(v)),
1308                                 SD_JSON_BUILD_PAIR("raw", SD_JSON_BUILD_BASE64(rri->rr->wire_format, rri->rr->wire_format_size)),
1309                                 SD_JSON_BUILD_PAIR_CONDITION(rri->ifindex > 0, "ifindex", SD_JSON_BUILD_INTEGER(rri->ifindex)));
1310                 if (r < 0)
1311                         return log_debug_errno(r, "Failed to append notification entry to array: %m");
1312         }
1313
1314         r = varlink_many_notifybo(
1315                         m->varlink_query_results_subscription,
1316                         SD_JSON_BUILD_PAIR("state", SD_JSON_BUILD_STRING(dns_transaction_state_to_string(q->state))),
1317                         SD_JSON_BUILD_PAIR_CONDITION(q->state == DNS_TRANSACTION_DNSSEC_FAILED,
1318                                                      "result", SD_JSON_BUILD_STRING(dnssec_result_to_string(q->answer_dnssec_result))),
1319                         SD_JSON_BUILD_PAIR_CONDITION(q->state == DNS_TRANSACTION_RCODE_FAILURE,
1320                                                      "rcode", SD_JSON_BUILD_INTEGER(q->answer_rcode)),
1321                         SD_JSON_BUILD_PAIR_CONDITION(q->state == DNS_TRANSACTION_ERRNO,
1322                                                      "errno", SD_JSON_BUILD_INTEGER(q->answer_errno)),
1323                         SD_JSON_BUILD_PAIR_CONDITION(IN_SET(q->state,
1324                                                             DNS_TRANSACTION_DNSSEC_FAILED,
1325                                                             DNS_TRANSACTION_RCODE_FAILURE) &&
1326                                                      q->answer_ede_rcode >= 0,
1327                                                      "extendedDNSErrorCode", SD_JSON_BUILD_INTEGER(q->answer_ede_rcode)),
1328                         SD_JSON_BUILD_PAIR_CONDITION(IN_SET(q->state,
1329                                                             DNS_TRANSACTION_DNSSEC_FAILED,
1330                                                             DNS_TRANSACTION_RCODE_FAILURE) &&
1331                                                      q->answer_ede_rcode >= 0 && !isempty(q->answer_ede_msg),
1332                                                      "extendedDNSErrorMessage", SD_JSON_BUILD_STRING(q->answer_ede_msg)),
1333                         SD_JSON_BUILD_PAIR("question", SD_JSON_BUILD_VARIANT(jquestion)),
1334                         SD_JSON_BUILD_PAIR_CONDITION(!!jcollected_questions,
1335                                                      "collectedQuestions", SD_JSON_BUILD_VARIANT(jcollected_questions)),
1336                         SD_JSON_BUILD_PAIR_CONDITION(!!janswer,
1337                                                              "answer", SD_JSON_BUILD_VARIANT(janswer)));
1338         if (r < 0)
1339                 log_debug_errno(r, "Failed to send monitor event, ignoring: %m");
1340
1341         return 0;
1342 }
1343
1344 int manager_send(
1345                 Manager *m,
1346                 int fd,
1347                 int ifindex,
1348                 int family,
1349                 const union in_addr_union *destination,
1350                 uint16_t port,
1351                 const union in_addr_union *source,
1352                 DnsPacket *p) {
1353
1354         assert(m);
1355         assert(fd >= 0);
1356         assert(destination);
1357         assert(port > 0);
1358         assert(p);
1359
1360         /* For mDNS, it is natural that the packet have truncated flag when we have many known answers. */
1361         bool truncated = DNS_PACKET_TC(p) && (p->protocol != DNS_PROTOCOL_MDNS || !p->more);
1362
1363         log_debug("Sending %s%s packet with id %" PRIu16 " on interface %i/%s of size %zu.",
1364                   truncated ? "truncated (!) " : "",
1365                   DNS_PACKET_QR(p) ? "response" : "query",
1366                   DNS_PACKET_ID(p),
1367                   ifindex, af_to_name(family),
1368                   p->size);
1369
1370         if (family == AF_INET)
1371                 return manager_ipv4_send(m, fd, ifindex, &destination->in, port, source ? &source->in : NULL, p);
1372         if (family == AF_INET6)
1373                 return manager_ipv6_send(m, fd, ifindex, &destination->in6, port, source ? &source->in6 : NULL, p);
1374
1375         return -EAFNOSUPPORT;
1376 }
1377
1378 uint32_t manager_find_mtu(Manager *m) {
1379         uint32_t mtu = 0;
1380         Link *l;
1381
1382         /* If we don't know on which link a DNS packet would be delivered, let's find the largest MTU that
1383          * works on all interfaces we know of that have an IP address associated */
1384
1385         HASHMAP_FOREACH(l, m->links) {
1386                 /* Let's filter out links without IP addresses (e.g. AF_CAN links and suchlike) */
1387                 if (!l->addresses)
1388                         continue;
1389
1390                 /* Safety check: MTU shorter than what we need for the absolutely shortest DNS request? Then
1391                  * let's ignore this link. */
1392                 if (l->mtu < MIN(UDP4_PACKET_HEADER_SIZE + DNS_PACKET_HEADER_SIZE,
1393                                  UDP6_PACKET_HEADER_SIZE + DNS_PACKET_HEADER_SIZE))
1394                         continue;
1395
1396                 if (mtu <= 0 || l->mtu < mtu)
1397                         mtu = l->mtu;
1398         }
1399
1400         if (mtu == 0) /* found nothing? then let's assume the typical Ethernet MTU for lack of anything more precise */
1401                 return 1500;
1402
1403         return mtu;
1404 }
1405
1406 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
1407         LinkAddress *a;
1408
1409         assert(m);
1410
1411         if (!IN_SET(family, AF_INET, AF_INET6))
1412                 return 0;
1413
1414         if (!in_addr)
1415                 return 0;
1416
1417         a = manager_find_link_address(m, family, in_addr);
1418         if (a)
1419                 return a->link->ifindex;
1420
1421         return 0;
1422 }
1423
1424 void manager_refresh_rrs(Manager *m) {
1425         Link *l;
1426         DnssdRegisteredService *s;
1427
1428         assert(m);
1429
1430         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
1431         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
1432         m->mdns_host_ipv4_key = dns_resource_key_unref(m->mdns_host_ipv4_key);
1433         m->mdns_host_ipv6_key = dns_resource_key_unref(m->mdns_host_ipv6_key);
1434
1435         HASHMAP_FOREACH(l, m->links)
1436                 link_add_rrs(l, true);
1437
1438         if (m->mdns_support == RESOLVE_SUPPORT_YES)
1439                 HASHMAP_FOREACH(s, m->dnssd_registered_services)
1440                         if (dnssd_update_rrs(s) < 0)
1441                                 log_warning("Failed to refresh DNS-SD service '%s'", s->id);
1442
1443         HASHMAP_FOREACH(l, m->links)
1444                 link_add_rrs(l, false);
1445 }
1446
1447 static int manager_next_random_name(const char *old, char **ret_new) {
1448         const char *p;
1449         uint64_t u, a;
1450         char *n;
1451
1452         p = strchr(old, 0);
1453         assert(p);
1454
1455         while (p > old) {
1456                 if (!ascii_isdigit(p[-1]))
1457                         break;
1458
1459                 p--;
1460         }
1461
1462         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
1463                 u = 1;
1464
1465         /* Add a random number to the old value. This way we can avoid
1466          * that two hosts pick the same hostname, win on IPv4 and lose
1467          * on IPv6 (or vice versa), and pick the same hostname
1468          * replacement hostname, ad infinitum. We still want the
1469          * numbers to go up monotonically, hence we just add a random
1470          * value 1..10 */
1471
1472         random_bytes(&a, sizeof(a));
1473         u += 1 + a % 10;
1474
1475         if (asprintf(&n, "%.*s%" PRIu64, (int) (p - old), old, u) < 0)
1476                 return -ENOMEM;
1477
1478         *ret_new = n;
1479
1480         return 0;
1481 }
1482
1483 int manager_next_hostname(Manager *m) {
1484         _cleanup_free_ char *h = NULL, *k = NULL;
1485         int r;
1486
1487         assert(m);
1488
1489         r = manager_next_random_name(m->llmnr_hostname, &h);
1490         if (r < 0)
1491                 return r;
1492
1493         r = dns_name_concat(h, "local", 0, &k);
1494         if (r < 0)
1495                 return r;
1496
1497         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1498
1499         free_and_replace(m->llmnr_hostname, h);
1500         free_and_replace(m->mdns_hostname, k);
1501
1502         manager_refresh_rrs(m);
1503         (void) manager_send_changed(m, "LLMNRHostname");
1504
1505         return 0;
1506 }
1507
1508 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1509         Link *l;
1510
1511         assert(m);
1512
1513         if (!IN_SET(family, AF_INET, AF_INET6))
1514                 return NULL;
1515
1516         if (!in_addr)
1517                 return NULL;
1518
1519         HASHMAP_FOREACH(l, m->links) {
1520                 LinkAddress *a;
1521
1522                 a = link_find_address(l, family, in_addr);
1523                 if (a)
1524                         return a;
1525         }
1526
1527         return NULL;
1528 }
1529
1530 bool manager_packet_from_local_address(Manager *m, DnsPacket *p) {
1531         assert(m);
1532         assert(p);
1533
1534         /* Let's see if this packet comes from an IP address we have on any local interface */
1535
1536         return !!manager_find_link_address(m, p->family, &p->sender);
1537 }
1538
1539 bool manager_packet_from_our_transaction(Manager *m, DnsPacket *p) {
1540         DnsTransaction *t;
1541
1542         assert(m);
1543         assert(p);
1544
1545         /* Let's see if we have a transaction with a query message with the exact same binary contents as the
1546          * one we just got. If so, it's almost definitely a packet loop of some kind. */
1547
1548         t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));
1549         if (!t)
1550                 return false;
1551
1552         return t->sent && dns_packet_equal(t->sent, p);
1553 }
1554
1555 DnsScope* manager_find_scope_from_protocol(Manager *m, int ifindex, DnsProtocol protocol, int family) {
1556         Link *l;
1557
1558         assert(m);
1559
1560         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
1561         if (!l)
1562                 return NULL;
1563
1564         switch (protocol) {
1565         case DNS_PROTOCOL_LLMNR:
1566                 if (family == AF_INET)
1567                         return l->llmnr_ipv4_scope;
1568                 else if (family == AF_INET6)
1569                         return l->llmnr_ipv6_scope;
1570
1571                 break;
1572
1573         case DNS_PROTOCOL_MDNS:
1574                 if (family == AF_INET)
1575                         return l->mdns_ipv4_scope;
1576                 else if (family == AF_INET6)
1577                         return l->mdns_ipv6_scope;
1578
1579                 break;
1580
1581         default:
1582                 ;
1583         }
1584
1585         return NULL;
1586 }
1587
1588 void manager_verify_all(Manager *m) {
1589         assert(m);
1590
1591         LIST_FOREACH(scopes, s, m->dns_scopes)
1592                 dns_zone_verify_all(&s->zone);
1593 }
1594
1595 int manager_is_own_hostname(Manager *m, const char *name) {
1596         int r;
1597
1598         assert(m);
1599         assert(name);
1600
1601         if (m->llmnr_hostname) {
1602                 r = dns_name_equal(name, m->llmnr_hostname);
1603                 if (r != 0)
1604                         return r;
1605         }
1606
1607         if (m->mdns_hostname) {
1608                 r = dns_name_equal(name, m->mdns_hostname);
1609                 if (r != 0)
1610                         return r;
1611         }
1612
1613         if (m->full_hostname)
1614                 return dns_name_equal(name, m->full_hostname);
1615
1616         return 0;
1617 }
1618
1619 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1620         Link *l;
1621         int r;
1622
1623         assert(m);
1624         assert(dns);
1625
1626         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1627         if (r < 0)
1628                 return r;
1629
1630         /* First add the system-wide servers and domains */
1631         LIST_FOREACH(servers, s, m->dns_servers) {
1632                 r = ordered_set_put(*dns, s);
1633                 if (r == -EEXIST)
1634                         continue;
1635                 if (r < 0)
1636                         return r;
1637         }
1638
1639         /* Then, add the per-link servers */
1640         HASHMAP_FOREACH(l, m->links)
1641                 LIST_FOREACH(servers, s, l->dns_servers) {
1642                         r = ordered_set_put(*dns, s);
1643                         if (r == -EEXIST)
1644                                 continue;
1645                         if (r < 0)
1646                                 return r;
1647                 }
1648
1649         /* Third, add the delegate servers and domains */
1650         DnsDelegate *d;
1651         HASHMAP_FOREACH(d, m->delegates)
1652                 LIST_FOREACH(servers, s, d->dns_servers) {
1653                         r = ordered_set_put(*dns, s);
1654                         if (r == -EEXIST)
1655                                 continue;
1656                         if (r < 0)
1657                                 return r;
1658                 }
1659
1660         /* If we found nothing, add the fallback servers */
1661         if (ordered_set_isempty(*dns)) {
1662                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1663                         r = ordered_set_put(*dns, s);
1664                         if (r == -EEXIST)
1665                                 continue;
1666                         if (r < 0)
1667                                 return r;
1668                 }
1669         }
1670
1671         return 0;
1672 }
1673
1674 /* filter_route is a tri-state:
1675  *   < 0: no filtering
1676  *   = 0 or false: return only domains which should be used for searching
1677  *   > 0 or true: return only domains which are for routing only
1678  */
1679 int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) {
1680         int r;
1681
1682         assert(m);
1683         assert(domains);
1684
1685         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1686         if (r < 0)
1687                 return r;
1688
1689         LIST_FOREACH(domains, d, m->search_domains) {
1690
1691                 if (filter_route >= 0 &&
1692                     d->route_only != !!filter_route)
1693                         continue;
1694
1695                 r = ordered_set_put(*domains, d->name);
1696                 if (r == -EEXIST)
1697                         continue;
1698                 if (r < 0)
1699                         return r;
1700         }
1701
1702         DnsDelegate *delegate;
1703         HASHMAP_FOREACH(delegate, m->delegates)
1704                 LIST_FOREACH(domains, d, delegate->search_domains) {
1705
1706                         if (filter_route >= 0 &&
1707                             d->route_only != !!filter_route)
1708                                 continue;
1709
1710                         r = ordered_set_put(*domains, d->name);
1711                         if (r == -EEXIST)
1712                                 continue;
1713                         if (r < 0)
1714                                 return r;
1715                 }
1716
1717         Link *l;
1718         HASHMAP_FOREACH(l, m->links)
1719                 LIST_FOREACH(domains, d, l->search_domains) {
1720
1721                         if (filter_route >= 0 &&
1722                             d->route_only != !!filter_route)
1723                                 continue;
1724
1725                         r = ordered_set_put(*domains, d->name);
1726                         if (r == -EEXIST)
1727                                 continue;
1728                         if (r < 0)
1729                                 return r;
1730                 }
1731
1732         return 0;
1733 }
1734
1735 DnssecMode manager_get_dnssec_mode(Manager *m) {
1736         assert(m);
1737
1738         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1739                 return m->dnssec_mode;
1740
1741         return DNSSEC_NO;
1742 }
1743
1744 bool manager_dnssec_supported(Manager *m) {
1745         DnsServer *server;
1746         Link *l;
1747
1748         assert(m);
1749
1750         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1751                 return false;
1752
1753         server = manager_get_dns_server(m);
1754         if (server && !dns_server_dnssec_supported(server))
1755                 return false;
1756
1757         HASHMAP_FOREACH(l, m->links)
1758                 if (!link_dnssec_supported(l))
1759                         return false;
1760
1761         return true;
1762 }
1763
1764 DnsOverTlsMode manager_get_dns_over_tls_mode(Manager *m) {
1765         assert(m);
1766
1767         if (m->dns_over_tls_mode != _DNS_OVER_TLS_MODE_INVALID)
1768                 return m->dns_over_tls_mode;
1769
1770         return DNS_OVER_TLS_NO;
1771 }
1772
1773 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1774
1775         assert(verdict >= 0);
1776         assert(verdict < _DNSSEC_VERDICT_MAX);
1777
1778         if (DEBUG_LOGGING) {
1779                 char s[DNS_RESOURCE_KEY_STRING_MAX];
1780
1781                 log_debug("Found verdict for lookup %s: %s",
1782                           dns_resource_key_to_string(key, s, sizeof s),
1783                           dnssec_verdict_to_string(verdict));
1784         }
1785
1786         m->n_dnssec_verdict[verdict]++;
1787 }
1788
1789 bool manager_routable(Manager *m) {
1790         Link *l;
1791
1792         assert(m);
1793
1794         /* Returns true if the host has at least one interface with a routable address (regardless if IPv4 or IPv6) */
1795
1796         HASHMAP_FOREACH(l, m->links)
1797                 if (link_relevant(l, AF_UNSPEC, false))
1798                         return true;
1799
1800         return false;
1801 }
1802
1803 void manager_flush_caches(Manager *m, int log_level) {
1804         assert(m);
1805
1806         LIST_FOREACH(scopes, scope, m->dns_scopes)
1807                 dns_cache_flush(&scope->cache);
1808
1809         dns_browse_services_purge(m, AF_UNSPEC); /* Clear records of DNS service browse subscriber, since caches are flushed */
1810         dns_browse_services_restart(m);
1811
1812         log_full(log_level, "Flushed all caches.");
1813 }
1814
1815 void manager_reset_server_features(Manager *m) {
1816
1817         dns_server_reset_features_all(m->dns_servers);
1818         dns_server_reset_features_all(m->fallback_dns_servers);
1819
1820         Link *l;
1821         HASHMAP_FOREACH(l, m->links)
1822                 dns_server_reset_features_all(l->dns_servers);
1823
1824         DnsDelegate *d;
1825         HASHMAP_FOREACH(d, m->delegates)
1826                 dns_server_reset_features_all(d->dns_servers);
1827
1828         log_info("Resetting learnt feature levels on all servers.");
1829 }
1830
1831 void manager_cleanup_saved_user(Manager *m) {
1832         _cleanup_closedir_ DIR *d = NULL;
1833
1834         assert(m);
1835
1836         /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface
1837          * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can
1838          * be restarted without losing this data. */
1839
1840         d = opendir("/run/systemd/resolve/netif/");
1841         if (!d) {
1842                 if (errno == ENOENT)
1843                         return;
1844
1845                 log_warning_errno(errno, "Failed to open interface directory: %m");
1846                 return;
1847         }
1848
1849         FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) {
1850                 int ifindex;
1851                 Link *l;
1852
1853                 if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG))
1854                         continue;
1855
1856                 if (dot_or_dot_dot(de->d_name))
1857                         continue;
1858
1859                 ifindex = parse_ifindex(de->d_name);
1860                 if (ifindex < 0) /* Probably some temporary file from a previous run. Delete it */
1861                         goto rm;
1862
1863                 l = hashmap_get(m->links, INT_TO_PTR(ifindex));
1864                 if (!l) /* link vanished */
1865                         goto rm;
1866
1867                 if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */
1868                         goto rm;
1869
1870                 continue;
1871
1872         rm:
1873                 if (unlinkat(dirfd(d), de->d_name, 0) < 0)
1874                         log_warning_errno(errno, "Failed to remove left-over interface configuration file '%s', ignoring: %m", de->d_name);
1875         }
1876 }
1877
1878 bool manager_next_dnssd_names(Manager *m) {
1879         DnssdRegisteredService *s;
1880         bool tried = false;
1881         int r;
1882
1883         assert(m);
1884
1885         HASHMAP_FOREACH(s, m->dnssd_registered_services) {
1886                 _cleanup_free_ char * new_name = NULL;
1887
1888                 if (!s->withdrawn)
1889                         continue;
1890
1891                 r = manager_next_random_name(s->name_template, &new_name);
1892                 if (r < 0) {
1893                         log_warning_errno(r, "Failed to get new name for service '%s': %m", s->id);
1894                         continue;
1895                 }
1896
1897                 free_and_replace(s->name_template, new_name);
1898
1899                 s->withdrawn = false;
1900
1901                 tried = true;
1902         }
1903
1904         if (tried)
1905                 manager_refresh_rrs(m);
1906
1907         return tried;
1908 }
1909
1910 bool manager_server_is_stub(Manager *m, DnsServer *s) {
1911         DnsStubListenerExtra *l;
1912
1913         assert(m);
1914         assert(s);
1915
1916         /* Safety check: we generally already skip the main stub when parsing configuration. But let's be
1917          * extra careful, and check here again */
1918         if (s->family == AF_INET &&
1919             s->address.in.s_addr == htobe32(INADDR_DNS_STUB) &&
1920             dns_server_port(s) == 53)
1921                 return true;
1922
1923         /* Main reason to call this is to check server data against the extra listeners, and filter things
1924          * out. */
1925         ORDERED_SET_FOREACH(l, m->dns_extra_stub_listeners)
1926                 if (s->family == l->family &&
1927                     in_addr_equal(s->family, &s->address, &l->address) &&
1928                     dns_server_port(s) == dns_stub_listener_extra_port(l))
1929                         return true;
1930
1931         return false;
1932 }
1933
1934 int socket_disable_pmtud(int fd, int af) {
1935         int r;
1936
1937         assert(fd >= 0);
1938
1939         if (af == AF_UNSPEC) {
1940                 af = socket_get_family(fd);
1941                 if (af < 0)
1942                         return af;
1943         }
1944
1945         switch (af) {
1946
1947         case AF_INET: {
1948                 /* Turn off path MTU discovery, let's rather fragment on the way than to open us up against
1949                  * PMTU forgery vulnerabilities.
1950                  *
1951                  * There appears to be no documentation about IP_PMTUDISC_OMIT, but it has the effect that
1952                  * the "Don't Fragment" bit in the IPv4 header is turned off, thus enforcing fragmentation if
1953                  * our datagram size exceeds the MTU of a router in the path, and turning off path MTU
1954                  * discovery.
1955                  *
1956                  * This helps mitigating the PMTUD vulnerability described here:
1957                  *
1958                  * https://blog.apnic.net/2019/07/12/its-time-to-consider-avoiding-ip-fragmentation-in-the-dns/
1959                  *
1960                  * Similar logic is in place in most DNS servers.
1961                  *
1962                  * There are multiple conflicting goals: we want to allow the largest datagrams possible (for
1963                  * efficiency reasons), but not have fragmentation (for security reasons), nor use PMTUD (for
1964                  * security reasons, too). Our strategy to deal with this is: use large packets, turn off
1965                  * PMTUD, but watch fragmentation taking place, and then size our packets to the max of the
1966                  * fragments seen — and if we need larger packets always go to TCP.
1967                  */
1968
1969                 r = setsockopt_int(fd, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_OMIT);
1970                 if (r < 0)
1971                         return r;
1972
1973                 return 0;
1974         }
1975
1976         case AF_INET6: {
1977                 /* On IPv6 fragmentation only is done by the sender — never by routers on the path. PMTUD is
1978                  * mandatory. If we want to turn off PMTUD, the only way is by sending with minimal MTU only,
1979                  * so that we apply maximum fragmentation locally already, and thus PMTUD doesn't happen
1980                  * because there's nothing that could be fragmented further anymore. */
1981
1982                 r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_MTU, IPV6_MIN_MTU);
1983                 if (r < 0)
1984                         return r;
1985
1986                 return 0;
1987         }
1988
1989         default:
1990                 return -EAFNOSUPPORT;
1991         }
1992 }
1993
1994 int dns_manager_dump_statistics_json(Manager *m, sd_json_variant **ret) {
1995         uint64_t size = 0, hit = 0, miss = 0;
1996
1997         assert(m);
1998         assert(ret);
1999
2000         LIST_FOREACH(scopes, s, m->dns_scopes) {
2001                 size += dns_cache_size(&s->cache);
2002                 hit += s->cache.n_hit;
2003                 miss += s->cache.n_miss;
2004         }
2005
2006         return sd_json_buildo(ret,
2007                               SD_JSON_BUILD_PAIR("transactions", SD_JSON_BUILD_OBJECT(
2008                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("currentTransactions", hashmap_size(m->dns_transactions)),
2009                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("totalTransactions", m->n_transactions_total),
2010                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("totalTimeouts", m->n_timeouts_total),
2011                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("totalTimeoutsServedStale", m->n_timeouts_served_stale_total),
2012                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("totalFailedResponses", m->n_failure_responses_total),
2013                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("totalFailedResponsesServedStale", m->n_failure_responses_served_stale_total)
2014                                                  )),
2015                               SD_JSON_BUILD_PAIR("cache", SD_JSON_BUILD_OBJECT(
2016                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("size", size),
2017                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("hits", hit),
2018                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("misses", miss)
2019                                                  )),
2020                               SD_JSON_BUILD_PAIR("dnssec", SD_JSON_BUILD_OBJECT(
2021                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("secure", m->n_dnssec_verdict[DNSSEC_SECURE]),
2022                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("insecure", m->n_dnssec_verdict[DNSSEC_INSECURE]),
2023                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("bogus", m->n_dnssec_verdict[DNSSEC_BOGUS]),
2024                                                                  SD_JSON_BUILD_PAIR_UNSIGNED("indeterminate", m->n_dnssec_verdict[DNSSEC_INDETERMINATE])
2025                                                  )));
2026 }
2027
2028 void dns_manager_reset_statistics(Manager *m) {
2029
2030         assert(m);
2031
2032         LIST_FOREACH(scopes, s, m->dns_scopes)
2033                 s->cache.n_hit = s->cache.n_miss = 0;
2034
2035         m->n_transactions_total = 0;
2036         m->n_timeouts_total = 0;
2037         m->n_timeouts_served_stale_total = 0;
2038         m->n_failure_responses_total = 0;
2039         m->n_failure_responses_served_stale_total = 0;
2040         zero(m->n_dnssec_verdict);
2041 }
2042
2043 static int dns_configuration_json_append(
2044                 const char *ifname,
2045                 int ifindex,
2046                 int default_route,
2047                 DnsServer *current_dns_server,
2048                 DnsServer *dns_servers,
2049                 DnsSearchDomain *search_domains,
2050                 sd_json_variant **configuration) {
2051
2052         _cleanup_(sd_json_variant_unrefp) sd_json_variant *dns_servers_json = NULL,
2053                                                           *search_domains_json = NULL,
2054                                                           *current_dns_server_json = NULL;
2055         int r;
2056
2057         assert(configuration);
2058
2059         if (dns_servers) {
2060                 r = sd_json_variant_new_array(&dns_servers_json, NULL, 0);
2061                 if (r < 0)
2062                         return r;
2063         }
2064
2065         if (search_domains) {
2066                 r = sd_json_variant_new_array(&search_domains_json, NULL, 0);
2067                 if (r < 0)
2068                         return r;
2069         }
2070
2071         if (current_dns_server) {
2072                 r = dns_server_dump_configuration_to_json(current_dns_server, &current_dns_server_json);
2073                 if (r < 0)
2074                         return r;
2075         }
2076
2077         LIST_FOREACH(servers, s, dns_servers) {
2078                 _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL;
2079
2080                 assert(dns_servers_json);
2081
2082                 r = dns_server_dump_configuration_to_json(s, &v);
2083                 if (r < 0)
2084                         return r;
2085
2086                 r = sd_json_variant_append_array(&dns_servers_json, v);
2087                 if (r < 0)
2088                         return r;
2089         }
2090
2091         LIST_FOREACH(domains, d, search_domains) {
2092                 _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL;
2093
2094                 assert(search_domains_json);
2095
2096                 r = dns_search_domain_dump_to_json(d, &v);
2097                 if (r < 0)
2098                         return r;
2099
2100                 r = sd_json_variant_append_array(&search_domains_json, v);
2101                 if (r < 0)
2102                         return r;
2103         }
2104
2105         return sd_json_variant_append_arraybo(
2106                         configuration,
2107                         JSON_BUILD_PAIR_STRING_NON_EMPTY("ifname", ifname),
2108                         SD_JSON_BUILD_PAIR_CONDITION(ifindex > 0, "ifindex", SD_JSON_BUILD_UNSIGNED(ifindex)),
2109                         SD_JSON_BUILD_PAIR_CONDITION(ifindex > 0, "defaultRoute", SD_JSON_BUILD_BOOLEAN(default_route > 0)),
2110                         JSON_BUILD_PAIR_VARIANT_NON_NULL("currentServer", current_dns_server_json),
2111                         JSON_BUILD_PAIR_VARIANT_NON_NULL("servers", dns_servers_json),
2112                         JSON_BUILD_PAIR_VARIANT_NON_NULL("searchDomains", search_domains_json));
2113 }
2114
2115 int manager_dump_dns_configuration_json(Manager *m, sd_json_variant **ret) {
2116         _cleanup_(sd_json_variant_unrefp) sd_json_variant *configuration = NULL;
2117         Link *l;
2118         int r;
2119
2120         assert(m);
2121         assert(ret);
2122
2123         /* Global DNS configuration */
2124         r = dns_configuration_json_append(
2125                         /* ifname = */ NULL,
2126                         /* ifindex = */ 0,
2127                         /* default_route = */ 0,
2128                         manager_get_dns_server(m),
2129                         m->dns_servers,
2130                         m->search_domains,
2131                         &configuration);
2132         if (r < 0)
2133                 return r;
2134
2135         /* Append configuration for each link */
2136         HASHMAP_FOREACH(l, m->links) {
2137                 r = dns_configuration_json_append(
2138                                 l->ifname,
2139                                 l->ifindex,
2140                                 link_get_default_route(l),
2141                                 link_get_dns_server(l),
2142                                 l->dns_servers,
2143                                 l->search_domains,
2144                                 &configuration);
2145                 if (r < 0)
2146                         return r;
2147         }
2148
2149         return sd_json_buildo(ret, SD_JSON_BUILD_PAIR_VARIANT("configuration", configuration));
2150 }
2151
2152 int manager_send_dns_configuration_changed(Manager *m, Link *l, bool reset) {
2153         _cleanup_(sd_json_variant_unrefp) sd_json_variant *configuration = NULL;
2154         int r;
2155
2156         assert(m);
2157
2158         if (set_isempty(m->varlink_dns_configuration_subscription))
2159                 return 0;
2160
2161         if (reset) {
2162                 dns_server_reset_accessible_all(m->dns_servers);
2163
2164                 if (l)
2165                         dns_server_reset_accessible_all(l->dns_servers);
2166         }
2167
2168         r = manager_dump_dns_configuration_json(m, &configuration);
2169         if (r < 0)
2170                 return log_warning_errno(r, "Failed to dump DNS configuration json: %m");
2171
2172         if (sd_json_variant_equal(configuration, m->dns_configuration_json))
2173                 return 0;
2174
2175         JSON_VARIANT_REPLACE(m->dns_configuration_json, TAKE_PTR(configuration));
2176
2177         r = varlink_many_notify(m->varlink_dns_configuration_subscription, m->dns_configuration_json);
2178         if (r < 0)
2179                 return log_warning_errno(r, "Failed to send DNS configuration event: %m");
2180
2181         return 0;
2182 }
2183
2184 int manager_start_dns_configuration_monitor(Manager *m) {
2185         Link *l;
2186         int r;
2187
2188         assert(m);
2189         assert(!m->dns_configuration_json);
2190         assert(!m->netlink_new_route_slot);
2191         assert(!m->netlink_del_route_slot);
2192
2193         dns_server_reset_accessible_all(m->dns_servers);
2194
2195         HASHMAP_FOREACH(l, m->links)
2196                 dns_server_reset_accessible_all(l->dns_servers);
2197
2198         r = manager_dump_dns_configuration_json(m, &m->dns_configuration_json);
2199         if (r < 0)
2200                 return r;
2201
2202         r = sd_netlink_add_match(m->rtnl, &m->netlink_new_route_slot, RTM_NEWROUTE, manager_process_route, NULL, m, "resolve-NEWROUTE");
2203         if (r < 0)
2204                 return r;
2205
2206         r = sd_netlink_add_match(m->rtnl, &m->netlink_del_route_slot, RTM_DELROUTE, manager_process_route, NULL, m, "resolve-DELROUTE");
2207         if (r < 0)
2208                 return r;
2209
2210         return 0;
2211 }
2212
2213 void manager_stop_dns_configuration_monitor(Manager *m) {
2214         assert(m);
2215
2216         m->dns_configuration_json = sd_json_variant_unref(m->dns_configuration_json);
2217         m->netlink_new_route_slot = sd_netlink_slot_unref(m->netlink_new_route_slot);
2218         m->netlink_del_route_slot = sd_netlink_slot_unref(m->netlink_del_route_slot);
2219 }