src/resolve/resolved-manager.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2014 Tom Gundersen <teg@jklm.no>
   6  ***/
   7
   8 #include <netinet/in.h>
   9 #include <poll.h>
  10 #include <stdio_ext.h>
  11 #include <sys/ioctl.h>
  12
  13 #if HAVE_LIBIDN2
  14 #include <idn2.h>
  15 #endif
  16
  17 #include "af-list.h"
  18 #include "alloc-util.h"
  19 #include "dirent-util.h"
  20 #include "dns-domain.h"
  21 #include "fd-util.h"
  22 #include "fileio-label.h"
  23 #include "hostname-util.h"
  24 #include "io-util.h"
  25 #include "netlink-util.h"
  26 #include "network-internal.h"
  27 #include "ordered-set.h"
  28 #include "parse-util.h"
  29 #include "random-util.h"
  30 #include "resolved-bus.h"
  31 #include "resolved-conf.h"
  32 #include "resolved-dnssd.h"
  33 #include "resolved-dns-stub.h"
  34 #include "resolved-etc-hosts.h"
  35 #include "resolved-llmnr.h"
  36 #include "resolved-manager.h"
  37 #include "resolved-mdns.h"
  38 #include "resolved-resolv-conf.h"
  39 #include "socket-util.h"
  40 #include "string-table.h"
  41 #include "string-util.h"
  42 #include "utf8.h"
  43
  44 #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
  45
  46 static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
  47         Manager *m = userdata;
  48         uint16_t type;
  49         Link *l;
  50         int ifindex, r;
  51
  52         assert(rtnl);
  53         assert(m);
  54         assert(mm);
  55
  56         r = sd_netlink_message_get_type(mm, &type);
  57         if (r < 0)
  58                 goto fail;
  59
  60         r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
  61         if (r < 0)
  62                 goto fail;
  63
  64         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
  65
  66         switch (type) {
  67
  68         case RTM_NEWLINK:{
  69                 bool is_new = !l;
  70
  71                 if (!l) {
  72                         r = link_new(m, &l, ifindex);
  73                         if (r < 0)
  74                                 goto fail;
  75                 }
  76
  77                 r = link_process_rtnl(l, mm);
  78                 if (r < 0)
  79                         goto fail;
  80
  81                 r = link_update(l);
  82                 if (r < 0)
  83                         goto fail;
  84
  85                 if (is_new)
  86                         log_debug("Found new link %i/%s", ifindex, l->name);
  87
  88                 break;
  89         }
  90
  91         case RTM_DELLINK:
  92                 if (l) {
  93                         log_debug("Removing link %i/%s", l->ifindex, l->name);
  94                         link_remove_user(l);
  95                         link_free(l);
  96                 }
  97
  98                 break;
  99         }
 100
 101         return 0;
 102
 103 fail:
 104         log_warning_errno(r, "Failed to process RTNL link message: %m");
 105         return 0;
 106 }
 107
 108 static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
 109         Manager *m = userdata;
 110         union in_addr_union address;
 111         uint16_t type;
 112         int r, ifindex, family;
 113         LinkAddress *a;
 114         Link *l;
 115
 116         assert(rtnl);
 117         assert(mm);
 118         assert(m);
 119
 120         r = sd_netlink_message_get_type(mm, &type);
 121         if (r < 0)
 122                 goto fail;
 123
 124         r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
 125         if (r < 0)
 126                 goto fail;
 127
 128         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
 129         if (!l)
 130                 return 0;
 131
 132         r = sd_rtnl_message_addr_get_family(mm, &family);
 133         if (r < 0)
 134                 goto fail;
 135
 136         switch (family) {
 137
 138         case AF_INET:
 139                 r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in);
 140                 if (r < 0) {
 141                         r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
 142                         if (r < 0)
 143                                 goto fail;
 144                 }
 145
 146                 break;
 147
 148         case AF_INET6:
 149                 r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
 150                 if (r < 0) {
 151                         r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
 152                         if (r < 0)
 153                                 goto fail;
 154                 }
 155
 156                 break;
 157
 158         default:
 159                 return 0;
 160         }
 161
 162         a = link_find_address(l, family, &address);
 163
 164         switch (type) {
 165
 166         case RTM_NEWADDR:
 167
 168                 if (!a) {
 169                         r = link_address_new(l, &a, family, &address);
 170                         if (r < 0)
 171                                 return r;
 172                 }
 173
 174                 r = link_address_update_rtnl(a, mm);
 175                 if (r < 0)
 176                         return r;
 177
 178                 break;
 179
 180         case RTM_DELADDR:
 181                 link_address_free(a);
 182                 break;
 183         }
 184
 185         return 0;
 186
 187 fail:
 188         log_warning_errno(r, "Failed to process RTNL address message: %m");
 189         return 0;
 190 }
 191
 192 static int manager_rtnl_listen(Manager *m) {
 193         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
 194         sd_netlink_message *i;
 195         int r;
 196
 197         assert(m);
 198
 199         /* First, subscribe to interfaces coming and going */
 200         r = sd_netlink_open(&m->rtnl);
 201         if (r < 0)
 202                 return r;
 203
 204         r = sd_netlink_attach_event(m->rtnl, m->event, SD_EVENT_PRIORITY_IMPORTANT);
 205         if (r < 0)
 206                 return r;
 207
 208         r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);
 209         if (r < 0)
 210                 return r;
 211
 212         r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);
 213         if (r < 0)
 214                 return r;
 215
 216         r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);
 217         if (r < 0)
 218                 return r;
 219
 220         r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m);
 221         if (r < 0)
 222                 return r;
 223
 224         /* Then, enumerate all links */
 225         r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
 226         if (r < 0)
 227                 return r;
 228
 229         r = sd_netlink_message_request_dump(req, true);
 230         if (r < 0)
 231                 return r;
 232
 233         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 234         if (r < 0)
 235                 return r;
 236
 237         for (i = reply; i; i = sd_netlink_message_next(i)) {
 238                 r = manager_process_link(m->rtnl, i, m);
 239                 if (r < 0)
 240                         return r;
 241         }
 242
 243         req = sd_netlink_message_unref(req);
 244         reply = sd_netlink_message_unref(reply);
 245
 246         /* Finally, enumerate all addresses, too */
 247         r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
 248         if (r < 0)
 249                 return r;
 250
 251         r = sd_netlink_message_request_dump(req, true);
 252         if (r < 0)
 253                 return r;
 254
 255         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 256         if (r < 0)
 257                 return r;
 258
 259         for (i = reply; i; i = sd_netlink_message_next(i)) {
 260                 r = manager_process_address(m->rtnl, i, m);
 261                 if (r < 0)
 262                         return r;
 263         }
 264
 265         return r;
 266 }
 267
 268 static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 269         Manager *m = userdata;
 270         Iterator i;
 271         Link *l;
 272         int r;
 273
 274         assert(m);
 275
 276         sd_network_monitor_flush(m->network_monitor);
 277
 278         HASHMAP_FOREACH(l, m->links, i) {
 279                 r = link_update(l);
 280                 if (r < 0)
 281                         log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
 282         }
 283
 284         (void) manager_write_resolv_conf(m);
 285
 286         return 0;
 287 }
 288
 289 static int manager_network_monitor_listen(Manager *m) {
 290         int r, fd, events;
 291
 292         assert(m);
 293
 294         r = sd_network_monitor_new(&m->network_monitor, NULL);
 295         if (r < 0)
 296                 return r;
 297
 298         fd = sd_network_monitor_get_fd(m->network_monitor);
 299         if (fd < 0)
 300                 return fd;
 301
 302         events = sd_network_monitor_get_events(m->network_monitor);
 303         if (events < 0)
 304                 return events;
 305
 306         r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m);
 307         if (r < 0)
 308                 return r;
 309
 310         r = sd_event_source_set_priority(m->network_event_source, SD_EVENT_PRIORITY_IMPORTANT+5);
 311         if (r < 0)
 312                 return r;
 313
 314         (void) sd_event_source_set_description(m->network_event_source, "network-monitor");
 315
 316         return 0;
 317 }
 318
 319 static int determine_hostname(char **full_hostname, char **llmnr_hostname, char **mdns_hostname) {
 320         _cleanup_free_ char *h = NULL, *n = NULL;
 321 #if HAVE_LIBIDN2
 322         _cleanup_free_ char *utf8 = NULL;
 323 #elif HAVE_LIBIDN
 324         int k;
 325 #endif
 326         char label[DNS_LABEL_MAX];
 327         const char *p, *decoded;
 328         int r;
 329
 330         assert(full_hostname);
 331         assert(llmnr_hostname);
 332         assert(mdns_hostname);
 333
 334         /* Extract and normalize the first label of the locally configured hostname, and check it's not "localhost". */
 335
 336         r = gethostname_strict(&h);
 337         if (r < 0)
 338                 return log_debug_errno(r, "Can't determine system hostname: %m");
 339
 340         p = h;
 341         r = dns_label_unescape(&p, label, sizeof label);
 342         if (r < 0)
 343                 return log_error_errno(r, "Failed to unescape host name: %m");
 344         if (r == 0) {
 345                 log_error("Couldn't find a single label in hostname.");
 346                 return -EINVAL;
 347         }
 348
 349 #if HAVE_LIBIDN2
 350         r = idn2_to_unicode_8z8z(label, &utf8, 0);
 351         if (r != IDN2_OK)
 352                 return log_error("Failed to undo IDNA: %s", idn2_strerror(r));
 353         assert(utf8_is_valid(utf8));
 354
 355         r = strlen(utf8);
 356         decoded = utf8;
 357 #elif HAVE_LIBIDN
 358         k = dns_label_undo_idna(label, r, label, sizeof label);
 359         if (k < 0)
 360                 return log_error_errno(k, "Failed to undo IDNA: %m");
 361         if (k > 0)
 362                 r = k;
 363
 364         if (!utf8_is_valid(label)) {
 365                 log_error("System hostname is not UTF-8 clean.");
 366                 return -EINVAL;
 367         }
 368         decoded = label;
 369 #else
 370         decoded = label; /* no decoding */
 371 #endif
 372
 373         r = dns_label_escape_new(decoded, r, &n);
 374         if (r < 0)
 375                 return log_error_errno(r, "Failed to escape host name: %m");
 376
 377         if (is_localhost(n)) {
 378                 log_debug("System hostname is 'localhost', ignoring.");
 379                 return -EINVAL;
 380         }
 381
 382         r = dns_name_concat(n, "local", mdns_hostname);
 383         if (r < 0)
 384                 return log_error_errno(r, "Failed to determine mDNS hostname: %m");
 385
 386         *llmnr_hostname = TAKE_PTR(n);
 387         *full_hostname = TAKE_PTR(h);
 388
 389         return 0;
 390 }
 391
 392 static const char *fallback_hostname(void) {
 393
 394         /* Determine the fall back hostname. For exposing this system to the outside world, we cannot have it to be
 395          * "localhost" even if that's the compiled in hostname. In this case, let's revert to "linux" instead. */
 396
 397         if (is_localhost(FALLBACK_HOSTNAME))
 398                 return "linux";
 399
 400         return FALLBACK_HOSTNAME;
 401 }
 402
 403 static int make_fallback_hostnames(char **full_hostname, char **llmnr_hostname, char **mdns_hostname) {
 404         _cleanup_free_ char *n = NULL, *m = NULL;
 405         char label[DNS_LABEL_MAX], *h;
 406         const char *p;
 407         int r;
 408
 409         assert(full_hostname);
 410         assert(llmnr_hostname);
 411         assert(mdns_hostname);
 412
 413         p = fallback_hostname();
 414         r = dns_label_unescape(&p, label, sizeof(label));
 415         if (r < 0)
 416                 return log_error_errno(r, "Failed to unescape fallback host name: %m");
 417
 418         assert(r > 0); /* The fallback hostname must have at least one label */
 419
 420         r = dns_label_escape_new(label, r, &n);
 421         if (r < 0)
 422                 return log_error_errno(r, "Failed to escape fallback hostname: %m");
 423
 424         r = dns_name_concat(n, "local", &m);
 425         if (r < 0)
 426                 return log_error_errno(r, "Failed to concatenate mDNS hostname: %m");
 427
 428         h = strdup(fallback_hostname());
 429         if (!h)
 430                 return log_oom();
 431
 432         *llmnr_hostname = TAKE_PTR(n);
 433         *mdns_hostname = TAKE_PTR(m);
 434
 435         *full_hostname = h;
 436
 437         return 0;
 438 }
 439
 440 static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
 441         _cleanup_free_ char *full_hostname = NULL, *llmnr_hostname = NULL, *mdns_hostname = NULL;
 442         Manager *m = userdata;
 443         int r;
 444
 445         assert(m);
 446
 447         r = determine_hostname(&full_hostname, &llmnr_hostname, &mdns_hostname);
 448         if (r < 0)
 449                 return 0; /* ignore invalid hostnames */
 450
 451         if (streq(full_hostname, m->full_hostname) &&
 452             streq(llmnr_hostname, m->llmnr_hostname) &&
 453             streq(mdns_hostname, m->mdns_hostname))
 454                 return 0;
 455
 456         log_info("System hostname changed to '%s'.", full_hostname);
 457
 458         free_and_replace(m->full_hostname, full_hostname);
 459         free_and_replace(m->llmnr_hostname, llmnr_hostname);
 460         free_and_replace(m->mdns_hostname, mdns_hostname);
 461
 462         manager_refresh_rrs(m);
 463
 464         return 0;
 465 }
 466
 467 static int manager_watch_hostname(Manager *m) {
 468         int r;
 469
 470         assert(m);
 471
 472         m->hostname_fd = open("/proc/sys/kernel/hostname",
 473                               O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
 474         if (m->hostname_fd < 0) {
 475                 log_warning_errno(errno, "Failed to watch hostname: %m");
 476                 return 0;
 477         }
 478
 479         r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
 480         if (r < 0) {
 481                 if (r == -EPERM)
 482                         /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
 483                         m->hostname_fd = safe_close(m->hostname_fd);
 484                 else
 485                         return log_error_errno(r, "Failed to add hostname event source: %m");
 486         }
 487
 488         (void) sd_event_source_set_description(m->hostname_event_source, "hostname");
 489
 490         r = determine_hostname(&m->full_hostname, &m->llmnr_hostname, &m->mdns_hostname);
 491         if (r < 0) {
 492                 log_info("Defaulting to hostname '%s'.", fallback_hostname());
 493
 494                 r = make_fallback_hostnames(&m->full_hostname, &m->llmnr_hostname, &m->mdns_hostname);
 495                 if (r < 0)
 496                         return r;
 497         } else
 498                 log_info("Using system hostname '%s'.", m->full_hostname);
 499
 500         return 0;
 501 }
 502
 503 static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 504         _cleanup_free_ char *buffer = NULL;
 505         _cleanup_fclose_ FILE *f = NULL;
 506         Manager *m = userdata;
 507         DnsServer *server;
 508         size_t size = 0;
 509         DnsScope *scope;
 510         Iterator i;
 511         Link *l;
 512
 513         assert(s);
 514         assert(si);
 515         assert(m);
 516
 517         f = open_memstream(&buffer, &size);
 518         if (!f)
 519                 return log_oom();
 520
 521         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 522
 523         LIST_FOREACH(scopes, scope, m->dns_scopes)
 524                 dns_scope_dump(scope, f);
 525
 526         LIST_FOREACH(servers, server, m->dns_servers)
 527                 dns_server_dump(server, f);
 528         LIST_FOREACH(servers, server, m->fallback_dns_servers)
 529                 dns_server_dump(server, f);
 530         HASHMAP_FOREACH(l, m->links, i)
 531                 LIST_FOREACH(servers, server, l->dns_servers)
 532                         dns_server_dump(server, f);
 533
 534         if (fflush_and_check(f) < 0)
 535                 return log_oom();
 536
 537         log_dump(LOG_INFO, buffer);
 538         return 0;
 539 }
 540
 541 static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 542         Manager *m = userdata;
 543
 544         assert(s);
 545         assert(si);
 546         assert(m);
 547
 548         manager_flush_caches(m);
 549
 550         return 0;
 551 }
 552
 553 static int manager_sigrtmin1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 554         Manager *m = userdata;
 555
 556         assert(s);
 557         assert(si);
 558         assert(m);
 559
 560         manager_reset_server_features(m);
 561         return 0;
 562 }
 563
 564 int manager_new(Manager **ret) {
 565         _cleanup_(manager_freep) Manager *m = NULL;
 566         int r;
 567
 568         assert(ret);
 569
 570         m = new0(Manager, 1);
 571         if (!m)
 572                 return -ENOMEM;
 573
 574         m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
 575         m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
 576         m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1;
 577         m->dns_stub_udp_fd = m->dns_stub_tcp_fd = -1;
 578         m->hostname_fd = -1;
 579
 580         m->llmnr_support = RESOLVE_SUPPORT_YES;
 581         m->mdns_support = RESOLVE_SUPPORT_YES;
 582         m->dnssec_mode = DEFAULT_DNSSEC_MODE;
 583         m->enable_cache = true;
 584         m->dns_stub_listener_mode = DNS_STUB_LISTENER_UDP;
 585         m->read_resolv_conf = true;
 586         m->need_builtin_fallbacks = true;
 587         m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY;
 588
 589         r = dns_trust_anchor_load(&m->trust_anchor);
 590         if (r < 0)
 591                 return r;
 592
 593         r = manager_parse_config_file(m);
 594         if (r < 0)
 595                 log_warning_errno(r, "Failed to parse configuration file: %m");
 596
 597         r = sd_event_default(&m->event);
 598         if (r < 0)
 599                 return r;
 600
 601         sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
 602         sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
 603
 604         sd_event_set_watchdog(m->event, true);
 605
 606         r = manager_watch_hostname(m);
 607         if (r < 0)
 608                 return r;
 609
 610         r = dnssd_load(m);
 611         if (r < 0)
 612                 log_warning_errno(r, "Failed to load DNS-SD configuration files: %m");
 613
 614         r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 615         if (r < 0)
 616                 return r;
 617
 618         r = manager_network_monitor_listen(m);
 619         if (r < 0)
 620                 return r;
 621
 622         r = manager_rtnl_listen(m);
 623         if (r < 0)
 624                 return r;
 625
 626         r = manager_connect_bus(m);
 627         if (r < 0)
 628                 return r;
 629
 630         (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m);
 631         (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m);
 632         (void) sd_event_add_signal(m->event, &m->sigrtmin1_event_source, SIGRTMIN+1, manager_sigrtmin1, m);
 633
 634         manager_cleanup_saved_user(m);
 635
 636         *ret = TAKE_PTR(m);
 637
 638         return 0;
 639 }
 640
 641 int manager_start(Manager *m) {
 642         int r;
 643
 644         assert(m);
 645
 646         r = manager_dns_stub_start(m);
 647         if (r < 0)
 648                 return r;
 649
 650         return 0;
 651 }
 652
 653 Manager *manager_free(Manager *m) {
 654         Link *l;
 655         DnssdService *s;
 656
 657         if (!m)
 658                 return NULL;
 659
 660         dns_server_unlink_all(m->dns_servers);
 661         dns_server_unlink_all(m->fallback_dns_servers);
 662         dns_search_domain_unlink_all(m->search_domains);
 663
 664         while ((l = hashmap_first(m->links)))
 665                link_free(l);
 666
 667         while (m->dns_queries)
 668                 dns_query_free(m->dns_queries);
 669
 670         dns_scope_free(m->unicast_scope);
 671
 672         /* At this point only orphaned streams should remain. All others should have been freed already by their
 673          * owners */
 674         while (m->dns_streams)
 675                 dns_stream_unref(m->dns_streams);
 676
 677         hashmap_free(m->links);
 678         hashmap_free(m->dns_transactions);
 679
 680         sd_event_source_unref(m->network_event_source);
 681         sd_network_monitor_unref(m->network_monitor);
 682
 683         sd_netlink_unref(m->rtnl);
 684         sd_event_source_unref(m->rtnl_event_source);
 685
 686         manager_llmnr_stop(m);
 687         manager_mdns_stop(m);
 688         manager_dns_stub_stop(m);
 689
 690         sd_bus_slot_unref(m->prepare_for_sleep_slot);
 691         sd_bus_unref(m->bus);
 692
 693         sd_event_source_unref(m->sigusr1_event_source);
 694         sd_event_source_unref(m->sigusr2_event_source);
 695         sd_event_source_unref(m->sigrtmin1_event_source);
 696
 697         sd_event_unref(m->event);
 698
 699         dns_resource_key_unref(m->llmnr_host_ipv4_key);
 700         dns_resource_key_unref(m->llmnr_host_ipv6_key);
 701         dns_resource_key_unref(m->mdns_host_ipv4_key);
 702         dns_resource_key_unref(m->mdns_host_ipv6_key);
 703
 704         sd_event_source_unref(m->hostname_event_source);
 705         safe_close(m->hostname_fd);
 706
 707         free(m->full_hostname);
 708         free(m->llmnr_hostname);
 709         free(m->mdns_hostname);
 710
 711         while ((s = hashmap_first(m->dnssd_services)))
 712                dnssd_service_free(s);
 713         hashmap_free(m->dnssd_services);
 714
 715         dns_trust_anchor_flush(&m->trust_anchor);
 716         manager_etc_hosts_flush(m);
 717
 718         return mfree(m);
 719 }
 720
 721 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 722         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 723         union {
 724                 struct cmsghdr header; /* For alignment */
 725                 uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 726                                + CMSG_SPACE(int) /* ttl/hoplimit */
 727                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
 728         } control;
 729         union sockaddr_union sa;
 730         struct msghdr mh = {};
 731         struct cmsghdr *cmsg;
 732         struct iovec iov;
 733         ssize_t ms, l;
 734         int r;
 735
 736         assert(m);
 737         assert(fd >= 0);
 738         assert(ret);
 739
 740         ms = next_datagram_size_fd(fd);
 741         if (ms < 0)
 742                 return ms;
 743
 744         r = dns_packet_new(&p, protocol, ms, DNS_PACKET_SIZE_MAX);
 745         if (r < 0)
 746                 return r;
 747
 748         iov.iov_base = DNS_PACKET_DATA(p);
 749         iov.iov_len = p->allocated;
 750
 751         mh.msg_name = &sa.sa;
 752         mh.msg_namelen = sizeof(sa);
 753         mh.msg_iov = &iov;
 754         mh.msg_iovlen = 1;
 755         mh.msg_control = &control;
 756         mh.msg_controllen = sizeof(control);
 757
 758         l = recvmsg(fd, &mh, 0);
 759         if (l == 0)
 760                 return 0;
 761         if (l < 0) {
 762                 if (IN_SET(errno, EAGAIN, EINTR))
 763                         return 0;
 764
 765                 return -errno;
 766         }
 767
 768         assert(!(mh.msg_flags & MSG_CTRUNC));
 769         assert(!(mh.msg_flags & MSG_TRUNC));
 770
 771         p->size = (size_t) l;
 772
 773         p->family = sa.sa.sa_family;
 774         p->ipproto = IPPROTO_UDP;
 775         if (p->family == AF_INET) {
 776                 p->sender.in = sa.in.sin_addr;
 777                 p->sender_port = be16toh(sa.in.sin_port);
 778         } else if (p->family == AF_INET6) {
 779                 p->sender.in6 = sa.in6.sin6_addr;
 780                 p->sender_port = be16toh(sa.in6.sin6_port);
 781                 p->ifindex = sa.in6.sin6_scope_id;
 782         } else
 783                 return -EAFNOSUPPORT;
 784
 785         CMSG_FOREACH(cmsg, &mh) {
 786
 787                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 788                         assert(p->family == AF_INET6);
 789
 790                         switch (cmsg->cmsg_type) {
 791
 792                         case IPV6_PKTINFO: {
 793                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 794
 795                                 if (p->ifindex <= 0)
 796                                         p->ifindex = i->ipi6_ifindex;
 797
 798                                 p->destination.in6 = i->ipi6_addr;
 799                                 break;
 800                         }
 801
 802                         case IPV6_HOPLIMIT:
 803                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 804                                 break;
 805
 806                         }
 807                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 808                         assert(p->family == AF_INET);
 809
 810                         switch (cmsg->cmsg_type) {
 811
 812                         case IP_PKTINFO: {
 813                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 814
 815                                 if (p->ifindex <= 0)
 816                                         p->ifindex = i->ipi_ifindex;
 817
 818                                 p->destination.in = i->ipi_addr;
 819                                 break;
 820                         }
 821
 822                         case IP_TTL:
 823                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 824                                 break;
 825                         }
 826                 }
 827         }
 828
 829         /* The Linux kernel sets the interface index to the loopback
 830          * device if the packet came from the local host since it
 831          * avoids the routing table in such a case. Let's unset the
 832          * interface index in such a case. */
 833         if (p->ifindex == LOOPBACK_IFINDEX)
 834                 p->ifindex = 0;
 835
 836         if (protocol != DNS_PROTOCOL_DNS) {
 837                 /* If we don't know the interface index still, we look for the
 838                  * first local interface with a matching address. Yuck! */
 839                 if (p->ifindex <= 0)
 840                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 841         }
 842
 843         *ret = TAKE_PTR(p);
 844
 845         return 1;
 846 }
 847
 848 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
 849         int r;
 850
 851         assert(fd >= 0);
 852         assert(mh);
 853
 854         for (;;) {
 855                 if (sendmsg(fd, mh, flags) >= 0)
 856                         return 0;
 857
 858                 if (errno == EINTR)
 859                         continue;
 860
 861                 if (errno != EAGAIN)
 862                         return -errno;
 863
 864                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 865                 if (r < 0)
 866                         return r;
 867                 if (r == 0)
 868                         return -ETIMEDOUT;
 869         }
 870 }
 871
 872 static int write_loop(int fd, void *message, size_t length) {
 873         int r;
 874
 875         assert(fd >= 0);
 876         assert(message);
 877
 878         for (;;) {
 879                 if (write(fd, message, length) >= 0)
 880                         return 0;
 881
 882                 if (errno == EINTR)
 883                         continue;
 884
 885                 if (errno != EAGAIN)
 886                         return -errno;
 887
 888                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 889                 if (r < 0)
 890                         return r;
 891                 if (r == 0)
 892                         return -ETIMEDOUT;
 893         }
 894 }
 895
 896 int manager_write(Manager *m, int fd, DnsPacket *p) {
 897         int r;
 898
 899         log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
 900
 901         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
 902         if (r < 0)
 903                 return r;
 904
 905         return 0;
 906 }
 907
 908 static int manager_ipv4_send(
 909                 Manager *m,
 910                 int fd,
 911                 int ifindex,
 912                 const struct in_addr *destination,
 913                 uint16_t port,
 914                 const struct in_addr *source,
 915                 DnsPacket *p) {
 916         union sockaddr_union sa = {
 917                 .in.sin_family = AF_INET,
 918         };
 919         union {
 920                 struct cmsghdr header; /* For alignment */
 921                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
 922         } control;
 923         struct msghdr mh = {};
 924         struct iovec iov;
 925
 926         assert(m);
 927         assert(fd >= 0);
 928         assert(destination);
 929         assert(port > 0);
 930         assert(p);
 931
 932         iov.iov_base = DNS_PACKET_DATA(p);
 933         iov.iov_len = p->size;
 934
 935         sa.in.sin_addr = *destination;
 936         sa.in.sin_port = htobe16(port),
 937
 938         mh.msg_iov = &iov;
 939         mh.msg_iovlen = 1;
 940         mh.msg_name = &sa.sa;
 941         mh.msg_namelen = sizeof(sa.in);
 942
 943         if (ifindex > 0) {
 944                 struct cmsghdr *cmsg;
 945                 struct in_pktinfo *pi;
 946
 947                 zero(control);
 948
 949                 mh.msg_control = &control;
 950                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
 951
 952                 cmsg = CMSG_FIRSTHDR(&mh);
 953                 cmsg->cmsg_len = mh.msg_controllen;
 954                 cmsg->cmsg_level = IPPROTO_IP;
 955                 cmsg->cmsg_type = IP_PKTINFO;
 956
 957                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
 958                 pi->ipi_ifindex = ifindex;
 959
 960                 if (source)
 961                         pi->ipi_spec_dst = *source;
 962         }
 963
 964         return sendmsg_loop(fd, &mh, 0);
 965 }
 966
 967 static int manager_ipv6_send(
 968                 Manager *m,
 969                 int fd,
 970                 int ifindex,
 971                 const struct in6_addr *destination,
 972                 uint16_t port,
 973                 const struct in6_addr *source,
 974                 DnsPacket *p) {
 975
 976         union sockaddr_union sa = {
 977                 .in6.sin6_family = AF_INET6,
 978         };
 979         union {
 980                 struct cmsghdr header; /* For alignment */
 981                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 982         } control;
 983         struct msghdr mh = {};
 984         struct iovec iov;
 985
 986         assert(m);
 987         assert(fd >= 0);
 988         assert(destination);
 989         assert(port > 0);
 990         assert(p);
 991
 992         iov.iov_base = DNS_PACKET_DATA(p);
 993         iov.iov_len = p->size;
 994
 995         sa.in6.sin6_addr = *destination;
 996         sa.in6.sin6_port = htobe16(port),
 997         sa.in6.sin6_scope_id = ifindex;
 998
 999         mh.msg_iov = &iov;
1000         mh.msg_iovlen = 1;
1001         mh.msg_name = &sa.sa;
1002         mh.msg_namelen = sizeof(sa.in6);
1003
1004         if (ifindex > 0) {
1005                 struct cmsghdr *cmsg;
1006                 struct in6_pktinfo *pi;
1007
1008                 zero(control);
1009
1010                 mh.msg_control = &control;
1011                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
1012
1013                 cmsg = CMSG_FIRSTHDR(&mh);
1014                 cmsg->cmsg_len = mh.msg_controllen;
1015                 cmsg->cmsg_level = IPPROTO_IPV6;
1016                 cmsg->cmsg_type = IPV6_PKTINFO;
1017
1018                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
1019                 pi->ipi6_ifindex = ifindex;
1020
1021                 if (source)
1022                         pi->ipi6_addr = *source;
1023         }
1024
1025         return sendmsg_loop(fd, &mh, 0);
1026 }
1027
1028 int manager_send(
1029                 Manager *m,
1030                 int fd,
1031                 int ifindex,
1032                 int family,
1033                 const union in_addr_union *destination,
1034                 uint16_t port,
1035                 const union in_addr_union *source,
1036                 DnsPacket *p) {
1037
1038         assert(m);
1039         assert(fd >= 0);
1040         assert(destination);
1041         assert(port > 0);
1042         assert(p);
1043
1044         log_debug("Sending %s packet with id %" PRIu16 " on interface %i/%s.", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family));
1045
1046         if (family == AF_INET)
1047                 return manager_ipv4_send(m, fd, ifindex, &destination->in, port, &source->in, p);
1048         if (family == AF_INET6)
1049                 return manager_ipv6_send(m, fd, ifindex, &destination->in6, port, &source->in6, p);
1050
1051         return -EAFNOSUPPORT;
1052 }
1053
1054 uint32_t manager_find_mtu(Manager *m) {
1055         uint32_t mtu = 0;
1056         Link *l;
1057         Iterator i;
1058
1059         /* If we don't know on which link a DNS packet would be
1060          * delivered, let's find the largest MTU that works on all
1061          * interfaces we know of */
1062
1063         HASHMAP_FOREACH(l, m->links, i) {
1064                 if (l->mtu <= 0)
1065                         continue;
1066
1067                 if (mtu <= 0 || l->mtu < mtu)
1068                         mtu = l->mtu;
1069         }
1070
1071         return mtu;
1072 }
1073
1074 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
1075         LinkAddress *a;
1076
1077         assert(m);
1078
1079         a = manager_find_link_address(m, family, in_addr);
1080         if (a)
1081                 return a->link->ifindex;
1082
1083         return 0;
1084 }
1085
1086 void manager_refresh_rrs(Manager *m) {
1087         Iterator i;
1088         Link *l;
1089         DnssdService *s;
1090
1091         assert(m);
1092
1093         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
1094         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
1095         m->mdns_host_ipv4_key = dns_resource_key_unref(m->mdns_host_ipv4_key);
1096         m->mdns_host_ipv6_key = dns_resource_key_unref(m->mdns_host_ipv6_key);
1097
1098         if (m->mdns_support == RESOLVE_SUPPORT_YES)
1099                 HASHMAP_FOREACH(s, m->dnssd_services, i)
1100                         if (dnssd_update_rrs(s) < 0)
1101                                 log_warning("Failed to refresh DNS-SD service '%s'", s->name);
1102
1103         HASHMAP_FOREACH(l, m->links, i) {
1104                 link_add_rrs(l, true);
1105                 link_add_rrs(l, false);
1106         }
1107 }
1108
1109 static int manager_next_random_name(const char *old, char **ret_new) {
1110         const char *p;
1111         uint64_t u, a;
1112         char *n;
1113
1114         p = strchr(old, 0);
1115         assert(p);
1116
1117         while (p > old) {
1118                 if (!strchr(DIGITS, p[-1]))
1119                         break;
1120
1121                 p--;
1122         }
1123
1124         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
1125                 u = 1;
1126
1127         /* Add a random number to the old value. This way we can avoid
1128          * that two hosts pick the same hostname, win on IPv4 and lose
1129          * on IPv6 (or vice versa), and pick the same hostname
1130          * replacement hostname, ad infinitum. We still want the
1131          * numbers to go up monotonically, hence we just add a random
1132          * value 1..10 */
1133
1134         random_bytes(&a, sizeof(a));
1135         u += 1 + a % 10;
1136
1137         if (asprintf(&n, "%.*s%" PRIu64, (int) (p - old), old, u) < 0)
1138                 return -ENOMEM;
1139
1140         *ret_new = n;
1141
1142         return 0;
1143 }
1144
1145 int manager_next_hostname(Manager *m) {
1146         _cleanup_free_ char *h = NULL, *k = NULL;
1147         int r;
1148
1149         assert(m);
1150
1151         r = manager_next_random_name(m->llmnr_hostname, &h);
1152         if (r < 0)
1153                 return r;
1154
1155         r = dns_name_concat(h, "local", &k);
1156         if (r < 0)
1157                 return r;
1158
1159         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1160
1161         free_and_replace(m->llmnr_hostname, h);
1162         free_and_replace(m->mdns_hostname, k);
1163
1164         manager_refresh_rrs(m);
1165
1166         return 0;
1167 }
1168
1169 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1170         Iterator i;
1171         Link *l;
1172
1173         assert(m);
1174
1175         HASHMAP_FOREACH(l, m->links, i) {
1176                 LinkAddress *a;
1177
1178                 a = link_find_address(l, family, in_addr);
1179                 if (a)
1180                         return a;
1181         }
1182
1183         return NULL;
1184 }
1185
1186 bool manager_our_packet(Manager *m, DnsPacket *p) {
1187         assert(m);
1188         assert(p);
1189
1190         return !!manager_find_link_address(m, p->family, &p->sender);
1191 }
1192
1193 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1194         Link *l;
1195
1196         assert(m);
1197         assert(p);
1198
1199         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1200         if (!l)
1201                 return NULL;
1202
1203         switch (p->protocol) {
1204         case DNS_PROTOCOL_LLMNR:
1205                 if (p->family == AF_INET)
1206                         return l->llmnr_ipv4_scope;
1207                 else if (p->family == AF_INET6)
1208                         return l->llmnr_ipv6_scope;
1209
1210                 break;
1211
1212         case DNS_PROTOCOL_MDNS:
1213                 if (p->family == AF_INET)
1214                         return l->mdns_ipv4_scope;
1215                 else if (p->family == AF_INET6)
1216                         return l->mdns_ipv6_scope;
1217
1218                 break;
1219
1220         default:
1221                 break;
1222         }
1223
1224         return NULL;
1225 }
1226
1227 void manager_verify_all(Manager *m) {
1228         DnsScope *s;
1229
1230         assert(m);
1231
1232         LIST_FOREACH(scopes, s, m->dns_scopes)
1233                 dns_zone_verify_all(&s->zone);
1234 }
1235
1236 int manager_is_own_hostname(Manager *m, const char *name) {
1237         int r;
1238
1239         assert(m);
1240         assert(name);
1241
1242         if (m->llmnr_hostname) {
1243                 r = dns_name_equal(name, m->llmnr_hostname);
1244                 if (r != 0)
1245                         return r;
1246         }
1247
1248         if (m->mdns_hostname) {
1249                 r = dns_name_equal(name, m->mdns_hostname);
1250                 if (r != 0)
1251                         return r;
1252         }
1253
1254         if (m->full_hostname)
1255                 return dns_name_equal(name, m->full_hostname);
1256
1257         return 0;
1258 }
1259
1260 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1261         DnsServer *s;
1262         Iterator i;
1263         Link *l;
1264         int r;
1265
1266         assert(m);
1267         assert(dns);
1268
1269         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1270         if (r < 0)
1271                 return r;
1272
1273         /* First add the system-wide servers and domains */
1274         LIST_FOREACH(servers, s, m->dns_servers) {
1275                 r = ordered_set_put(*dns, s);
1276                 if (r == -EEXIST)
1277                         continue;
1278                 if (r < 0)
1279                         return r;
1280         }
1281
1282         /* Then, add the per-link servers */
1283         HASHMAP_FOREACH(l, m->links, i) {
1284                 LIST_FOREACH(servers, s, l->dns_servers) {
1285                         r = ordered_set_put(*dns, s);
1286                         if (r == -EEXIST)
1287                                 continue;
1288                         if (r < 0)
1289                                 return r;
1290                 }
1291         }
1292
1293         /* If we found nothing, add the fallback servers */
1294         if (ordered_set_isempty(*dns)) {
1295                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1296                         r = ordered_set_put(*dns, s);
1297                         if (r == -EEXIST)
1298                                 continue;
1299                         if (r < 0)
1300                                 return r;
1301                 }
1302         }
1303
1304         return 0;
1305 }
1306
1307 /* filter_route is a tri-state:
1308  *   < 0: no filtering
1309  *   = 0 or false: return only domains which should be used for searching
1310  *   > 0 or true: return only domains which are for routing only
1311  */
1312 int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) {
1313         DnsSearchDomain *d;
1314         Iterator i;
1315         Link *l;
1316         int r;
1317
1318         assert(m);
1319         assert(domains);
1320
1321         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1322         if (r < 0)
1323                 return r;
1324
1325         LIST_FOREACH(domains, d, m->search_domains) {
1326
1327                 if (filter_route >= 0 &&
1328                     d->route_only != !!filter_route)
1329                         continue;
1330
1331                 r = ordered_set_put(*domains, d->name);
1332                 if (r == -EEXIST)
1333                         continue;
1334                 if (r < 0)
1335                         return r;
1336         }
1337
1338         HASHMAP_FOREACH(l, m->links, i) {
1339
1340                 LIST_FOREACH(domains, d, l->search_domains) {
1341
1342                         if (filter_route >= 0 &&
1343                             d->route_only != !!filter_route)
1344                                 continue;
1345
1346                         r = ordered_set_put(*domains, d->name);
1347                         if (r == -EEXIST)
1348                                 continue;
1349                         if (r < 0)
1350                                 return r;
1351                 }
1352         }
1353
1354         return 0;
1355 }
1356
1357 DnssecMode manager_get_dnssec_mode(Manager *m) {
1358         assert(m);
1359
1360         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1361                 return m->dnssec_mode;
1362
1363         return DNSSEC_NO;
1364 }
1365
1366 bool manager_dnssec_supported(Manager *m) {
1367         DnsServer *server;
1368         Iterator i;
1369         Link *l;
1370
1371         assert(m);
1372
1373         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1374                 return false;
1375
1376         server = manager_get_dns_server(m);
1377         if (server && !dns_server_dnssec_supported(server))
1378                 return false;
1379
1380         HASHMAP_FOREACH(l, m->links, i)
1381                 if (!link_dnssec_supported(l))
1382                         return false;
1383
1384         return true;
1385 }
1386
1387 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1388
1389         assert(verdict >= 0);
1390         assert(verdict < _DNSSEC_VERDICT_MAX);
1391
1392         if (DEBUG_LOGGING) {
1393                 char s[DNS_RESOURCE_KEY_STRING_MAX];
1394
1395                 log_debug("Found verdict for lookup %s: %s",
1396                           dns_resource_key_to_string(key, s, sizeof s),
1397                           dnssec_verdict_to_string(verdict));
1398         }
1399
1400         m->n_dnssec_verdict[verdict]++;
1401 }
1402
1403 bool manager_routable(Manager *m, int family) {
1404         Iterator i;
1405         Link *l;
1406
1407         assert(m);
1408
1409         /* Returns true if the host has at least one interface with a routable address of the specified type */
1410
1411         HASHMAP_FOREACH(l, m->links, i)
1412                 if (link_relevant(l, family, false))
1413                         return true;
1414
1415         return false;
1416 }
1417
1418 void manager_flush_caches(Manager *m) {
1419         DnsScope *scope;
1420
1421         assert(m);
1422
1423         LIST_FOREACH(scopes, scope, m->dns_scopes)
1424                 dns_cache_flush(&scope->cache);
1425
1426         log_info("Flushed all caches.");
1427 }
1428
1429 void manager_reset_server_features(Manager *m) {
1430         Iterator i;
1431         Link *l;
1432
1433         dns_server_reset_features_all(m->dns_servers);
1434         dns_server_reset_features_all(m->fallback_dns_servers);
1435
1436         HASHMAP_FOREACH(l, m->links, i)
1437                 dns_server_reset_features_all(l->dns_servers);
1438
1439         log_info("Resetting learnt feature levels on all servers.");
1440 }
1441
1442 void manager_cleanup_saved_user(Manager *m) {
1443         _cleanup_closedir_ DIR *d = NULL;
1444         struct dirent *de;
1445         int r;
1446
1447         assert(m);
1448
1449         /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface
1450          * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can
1451          * be restarted without losing this data. */
1452
1453         d = opendir("/run/systemd/resolve/netif/");
1454         if (!d) {
1455                 if (errno == ENOENT)
1456                         return;
1457
1458                 log_warning_errno(errno, "Failed to open interface directory: %m");
1459                 return;
1460         }
1461
1462         FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) {
1463                 _cleanup_free_ char *p = NULL;
1464                 int ifindex;
1465                 Link *l;
1466
1467                 if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG))
1468                         continue;
1469
1470                 if (dot_or_dot_dot(de->d_name))
1471                         continue;
1472
1473                 r = parse_ifindex(de->d_name, &ifindex);
1474                 if (r < 0) /* Probably some temporary file from a previous run. Delete it */
1475                         goto rm;
1476
1477                 l = hashmap_get(m->links, INT_TO_PTR(ifindex));
1478                 if (!l) /* link vanished */
1479                         goto rm;
1480
1481                 if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */
1482                         goto rm;
1483
1484                 continue;
1485
1486         rm:
1487                 p = strappend("/run/systemd/resolve/netif/", de->d_name);
1488                 if (!p) {
1489                         log_oom();
1490                         return;
1491                 }
1492
1493                 (void) unlink(p);
1494         }
1495 }
1496
1497 bool manager_next_dnssd_names(Manager *m) {
1498         Iterator i;
1499         DnssdService *s;
1500         bool tried = false;
1501         int r;
1502
1503         assert(m);
1504
1505         HASHMAP_FOREACH(s, m->dnssd_services, i) {
1506                 _cleanup_free_ char * new_name = NULL;
1507
1508                 if (!s->withdrawn)
1509                         continue;
1510
1511                 r = manager_next_random_name(s->name_template, &new_name);
1512                 if (r < 0) {
1513                         log_warning_errno(r, "Failed to get new name for service '%s': %m", s->name);
1514                         continue;
1515                 }
1516
1517                 free_and_replace(s->name_template, new_name);
1518
1519                 s->withdrawn = false;
1520
1521                 tried = true;
1522         }
1523
1524         if (tried)
1525                 manager_refresh_rrs(m);
1526
1527         return tried;
1528 }