src/resolve/resolved-manager.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Tom Gundersen <teg@jklm.no>
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18  ***/
  19
  20 #include <netinet/in.h>
  21 #include <poll.h>
  22 #include <sys/ioctl.h>
  23
  24 #include "af-list.h"
  25 #include "alloc-util.h"
  26 #include "dirent-util.h"
  27 #include "dns-domain.h"
  28 #include "fd-util.h"
  29 #include "fileio-label.h"
  30 #include "hostname-util.h"
  31 #include "io-util.h"
  32 #include "netlink-util.h"
  33 #include "network-internal.h"
  34 #include "ordered-set.h"
  35 #include "parse-util.h"
  36 #include "random-util.h"
  37 #include "resolved-bus.h"
  38 #include "resolved-conf.h"
  39 #include "resolved-dns-stub.h"
  40 #include "resolved-etc-hosts.h"
  41 #include "resolved-llmnr.h"
  42 #include "resolved-manager.h"
  43 #include "resolved-mdns.h"
  44 #include "resolved-resolv-conf.h"
  45 #include "socket-util.h"
  46 #include "string-table.h"
  47 #include "string-util.h"
  48 #include "utf8.h"
  49
  50 #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
  51
  52 static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
  53         Manager *m = userdata;
  54         uint16_t type;
  55         Link *l;
  56         int ifindex, r;
  57
  58         assert(rtnl);
  59         assert(m);
  60         assert(mm);
  61
  62         r = sd_netlink_message_get_type(mm, &type);
  63         if (r < 0)
  64                 goto fail;
  65
  66         r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
  67         if (r < 0)
  68                 goto fail;
  69
  70         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
  71
  72         switch (type) {
  73
  74         case RTM_NEWLINK:{
  75                 bool is_new = !l;
  76
  77                 if (!l) {
  78                         r = link_new(m, &l, ifindex);
  79                         if (r < 0)
  80                                 goto fail;
  81                 }
  82
  83                 r = link_process_rtnl(l, mm);
  84                 if (r < 0)
  85                         goto fail;
  86
  87                 r = link_update(l);
  88                 if (r < 0)
  89                         goto fail;
  90
  91                 if (is_new)
  92                         log_debug("Found new link %i/%s", ifindex, l->name);
  93
  94                 break;
  95         }
  96
  97         case RTM_DELLINK:
  98                 if (l) {
  99                         log_debug("Removing link %i/%s", l->ifindex, l->name);
 100                         link_remove_user(l);
 101                         link_free(l);
 102                 }
 103
 104                 break;
 105         }
 106
 107         return 0;
 108
 109 fail:
 110         log_warning_errno(r, "Failed to process RTNL link message: %m");
 111         return 0;
 112 }
 113
 114 static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
 115         Manager *m = userdata;
 116         union in_addr_union address;
 117         uint16_t type;
 118         int r, ifindex, family;
 119         LinkAddress *a;
 120         Link *l;
 121
 122         assert(rtnl);
 123         assert(mm);
 124         assert(m);
 125
 126         r = sd_netlink_message_get_type(mm, &type);
 127         if (r < 0)
 128                 goto fail;
 129
 130         r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
 131         if (r < 0)
 132                 goto fail;
 133
 134         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
 135         if (!l)
 136                 return 0;
 137
 138         r = sd_rtnl_message_addr_get_family(mm, &family);
 139         if (r < 0)
 140                 goto fail;
 141
 142         switch (family) {
 143
 144         case AF_INET:
 145                 r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in);
 146                 if (r < 0) {
 147                         r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
 148                         if (r < 0)
 149                                 goto fail;
 150                 }
 151
 152                 break;
 153
 154         case AF_INET6:
 155                 r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
 156                 if (r < 0) {
 157                         r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
 158                         if (r < 0)
 159                                 goto fail;
 160                 }
 161
 162                 break;
 163
 164         default:
 165                 return 0;
 166         }
 167
 168         a = link_find_address(l, family, &address);
 169
 170         switch (type) {
 171
 172         case RTM_NEWADDR:
 173
 174                 if (!a) {
 175                         r = link_address_new(l, &a, family, &address);
 176                         if (r < 0)
 177                                 return r;
 178                 }
 179
 180                 r = link_address_update_rtnl(a, mm);
 181                 if (r < 0)
 182                         return r;
 183
 184                 break;
 185
 186         case RTM_DELADDR:
 187                 link_address_free(a);
 188                 break;
 189         }
 190
 191         return 0;
 192
 193 fail:
 194         log_warning_errno(r, "Failed to process RTNL address message: %m");
 195         return 0;
 196 }
 197
 198 static int manager_rtnl_listen(Manager *m) {
 199         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
 200         sd_netlink_message *i;
 201         int r;
 202
 203         assert(m);
 204
 205         /* First, subscribe to interfaces coming and going */
 206         r = sd_netlink_open(&m->rtnl);
 207         if (r < 0)
 208                 return r;
 209
 210         r = sd_netlink_attach_event(m->rtnl, m->event, SD_EVENT_PRIORITY_IMPORTANT);
 211         if (r < 0)
 212                 return r;
 213
 214         r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);
 215         if (r < 0)
 216                 return r;
 217
 218         r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);
 219         if (r < 0)
 220                 return r;
 221
 222         r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);
 223         if (r < 0)
 224                 return r;
 225
 226         r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m);
 227         if (r < 0)
 228                 return r;
 229
 230         /* Then, enumerate all links */
 231         r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
 232         if (r < 0)
 233                 return r;
 234
 235         r = sd_netlink_message_request_dump(req, true);
 236         if (r < 0)
 237                 return r;
 238
 239         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 240         if (r < 0)
 241                 return r;
 242
 243         for (i = reply; i; i = sd_netlink_message_next(i)) {
 244                 r = manager_process_link(m->rtnl, i, m);
 245                 if (r < 0)
 246                         return r;
 247         }
 248
 249         req = sd_netlink_message_unref(req);
 250         reply = sd_netlink_message_unref(reply);
 251
 252         /* Finally, enumerate all addresses, too */
 253         r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
 254         if (r < 0)
 255                 return r;
 256
 257         r = sd_netlink_message_request_dump(req, true);
 258         if (r < 0)
 259                 return r;
 260
 261         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 262         if (r < 0)
 263                 return r;
 264
 265         for (i = reply; i; i = sd_netlink_message_next(i)) {
 266                 r = manager_process_address(m->rtnl, i, m);
 267                 if (r < 0)
 268                         return r;
 269         }
 270
 271         return r;
 272 }
 273
 274 static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 275         Manager *m = userdata;
 276         Iterator i;
 277         Link *l;
 278         int r;
 279
 280         assert(m);
 281
 282         sd_network_monitor_flush(m->network_monitor);
 283
 284         HASHMAP_FOREACH(l, m->links, i) {
 285                 r = link_update(l);
 286                 if (r < 0)
 287                         log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
 288         }
 289
 290         (void) manager_write_resolv_conf(m);
 291
 292         return 0;
 293 }
 294
 295 static int manager_network_monitor_listen(Manager *m) {
 296         int r, fd, events;
 297
 298         assert(m);
 299
 300         r = sd_network_monitor_new(&m->network_monitor, NULL);
 301         if (r < 0)
 302                 return r;
 303
 304         fd = sd_network_monitor_get_fd(m->network_monitor);
 305         if (fd < 0)
 306                 return fd;
 307
 308         events = sd_network_monitor_get_events(m->network_monitor);
 309         if (events < 0)
 310                 return events;
 311
 312         r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m);
 313         if (r < 0)
 314                 return r;
 315
 316         r = sd_event_source_set_priority(m->network_event_source, SD_EVENT_PRIORITY_IMPORTANT+5);
 317         if (r < 0)
 318                 return r;
 319
 320         (void) sd_event_source_set_description(m->network_event_source, "network-monitor");
 321
 322         return 0;
 323 }
 324
 325 static int determine_hostname(char **full_hostname, char **llmnr_hostname, char **mdns_hostname) {
 326         _cleanup_free_ char *h = NULL, *n = NULL;
 327         char label[DNS_LABEL_MAX];
 328         const char *p;
 329         int r, k;
 330
 331         assert(full_hostname);
 332         assert(llmnr_hostname);
 333         assert(mdns_hostname);
 334
 335         /* Extract and normalize the first label of the locally configured hostname, and check it's not "localhost". */
 336
 337         r = gethostname_strict(&h);
 338         if (r < 0)
 339                 return log_debug_errno(r, "Can't determine system hostname: %m");
 340
 341         p = h;
 342         r = dns_label_unescape(&p, label, sizeof(label));
 343         if (r < 0)
 344                 return log_error_errno(r, "Failed to unescape host name: %m");
 345         if (r == 0) {
 346                 log_error("Couldn't find a single label in hostname.");
 347                 return -EINVAL;
 348         }
 349
 350         k = dns_label_undo_idna(label, r, label, sizeof(label));
 351         if (k < 0)
 352                 return log_error_errno(k, "Failed to undo IDNA: %m");
 353         if (k > 0)
 354                 r = k;
 355
 356         if (!utf8_is_valid(label)) {
 357                 log_error("System hostname is not UTF-8 clean.");
 358                 return -EINVAL;
 359         }
 360
 361         r = dns_label_escape_new(label, r, &n);
 362         if (r < 0)
 363                 return log_error_errno(r, "Failed to escape host name: %m");
 364
 365         if (is_localhost(n)) {
 366                 log_debug("System hostname is 'localhost', ignoring.");
 367                 return -EINVAL;
 368         }
 369
 370         r = dns_name_concat(n, "local", mdns_hostname);
 371         if (r < 0)
 372                 return log_error_errno(r, "Failed to determine mDNS hostname: %m");
 373
 374         *llmnr_hostname = n;
 375         n = NULL;
 376
 377         *full_hostname = h;
 378         h = NULL;
 379
 380         return 0;
 381 }
 382
 383 static const char *fallback_hostname(void) {
 384
 385         /* Determine the fall back hostname. For exposing this system to the outside world, we cannot have it to be
 386          * "localhost" even if that's the compiled in hostname. In this case, let's revert to "linux" instead. */
 387
 388         if (is_localhost(FALLBACK_HOSTNAME))
 389                 return "linux";
 390
 391         return FALLBACK_HOSTNAME;
 392 }
 393
 394 static int make_fallback_hostnames(char **full_hostname, char **llmnr_hostname, char **mdns_hostname) {
 395         _cleanup_free_ char *n = NULL, *m = NULL;
 396         char label[DNS_LABEL_MAX], *h;
 397         const char *p;
 398         int r;
 399
 400         assert(full_hostname);
 401         assert(llmnr_hostname);
 402         assert(mdns_hostname);
 403
 404         p = fallback_hostname();
 405         r = dns_label_unescape(&p, label, sizeof(label));
 406         if (r < 0)
 407                 return log_error_errno(r, "Failed to unescape fallback host name: %m");
 408
 409         assert(r > 0); /* The fallback hostname must have at least one label */
 410
 411         r = dns_label_escape_new(label, r, &n);
 412         if (r < 0)
 413                 return log_error_errno(r, "Failed to escape fallback hostname: %m");
 414
 415         r = dns_name_concat(n, "local", &m);
 416         if (r < 0)
 417                 return log_error_errno(r, "Failed to concatenate mDNS hostname: %m");
 418
 419         h = strdup(fallback_hostname());
 420         if (!h)
 421                 return log_oom();
 422
 423         *llmnr_hostname = n;
 424         n = NULL;
 425
 426         *mdns_hostname = m;
 427         m = NULL;
 428
 429         *full_hostname = h;
 430
 431         return 0;
 432 }
 433
 434 static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
 435         _cleanup_free_ char *full_hostname = NULL, *llmnr_hostname = NULL, *mdns_hostname = NULL;
 436         Manager *m = userdata;
 437         int r;
 438
 439         assert(m);
 440
 441         r = determine_hostname(&full_hostname, &llmnr_hostname, &mdns_hostname);
 442         if (r < 0)
 443                 return 0; /* ignore invalid hostnames */
 444
 445         if (streq(full_hostname, m->full_hostname) &&
 446             streq(llmnr_hostname, m->llmnr_hostname) &&
 447             streq(mdns_hostname, m->mdns_hostname))
 448                 return 0;
 449
 450         log_info("System hostname changed to '%s'.", full_hostname);
 451
 452         free_and_replace(m->full_hostname, full_hostname);
 453         free_and_replace(m->llmnr_hostname, llmnr_hostname);
 454         free_and_replace(m->mdns_hostname, mdns_hostname);
 455
 456         manager_refresh_rrs(m);
 457
 458         return 0;
 459 }
 460
 461 static int manager_watch_hostname(Manager *m) {
 462         int r;
 463
 464         assert(m);
 465
 466         m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY);
 467         if (m->hostname_fd < 0) {
 468                 log_warning_errno(errno, "Failed to watch hostname: %m");
 469                 return 0;
 470         }
 471
 472         r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
 473         if (r < 0) {
 474                 if (r == -EPERM)
 475                         /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
 476                         m->hostname_fd = safe_close(m->hostname_fd);
 477                 else
 478                         return log_error_errno(r, "Failed to add hostname event source: %m");
 479         }
 480
 481         (void) sd_event_source_set_description(m->hostname_event_source, "hostname");
 482
 483         r = determine_hostname(&m->full_hostname, &m->llmnr_hostname, &m->mdns_hostname);
 484         if (r < 0) {
 485                 log_info("Defaulting to hostname '%s'.", fallback_hostname());
 486
 487                 r = make_fallback_hostnames(&m->full_hostname, &m->llmnr_hostname, &m->mdns_hostname);
 488                 if (r < 0)
 489                         return r;
 490         } else
 491                 log_info("Using system hostname '%s'.", m->full_hostname);
 492
 493         return 0;
 494 }
 495
 496 static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 497         _cleanup_free_ char *buffer = NULL;
 498         _cleanup_fclose_ FILE *f = NULL;
 499         Manager *m = userdata;
 500         size_t size = 0;
 501         DnsScope *scope;
 502
 503         assert(s);
 504         assert(si);
 505         assert(m);
 506
 507         f = open_memstream(&buffer, &size);
 508         if (!f)
 509                 return log_oom();
 510
 511         LIST_FOREACH(scopes, scope, m->dns_scopes)
 512                 dns_scope_dump(scope, f);
 513
 514         if (fflush_and_check(f) < 0)
 515                 return log_oom();
 516
 517         log_dump(LOG_INFO, buffer);
 518         return 0;
 519 }
 520
 521 static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 522         Manager *m = userdata;
 523
 524         assert(s);
 525         assert(si);
 526         assert(m);
 527
 528         manager_flush_caches(m);
 529
 530         return 0;
 531 }
 532
 533 int manager_new(Manager **ret) {
 534         _cleanup_(manager_freep) Manager *m = NULL;
 535         int r;
 536
 537         assert(ret);
 538
 539         m = new0(Manager, 1);
 540         if (!m)
 541                 return -ENOMEM;
 542
 543         m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
 544         m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
 545         m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1;
 546         m->dns_stub_udp_fd = m->dns_stub_tcp_fd = -1;
 547         m->hostname_fd = -1;
 548
 549         m->llmnr_support = RESOLVE_SUPPORT_YES;
 550         m->mdns_support = RESOLVE_SUPPORT_YES;
 551         m->dnssec_mode = DEFAULT_DNSSEC_MODE;
 552         m->enable_cache = true;
 553         m->dns_stub_listener_mode = DNS_STUB_LISTENER_UDP;
 554         m->read_resolv_conf = true;
 555         m->need_builtin_fallbacks = true;
 556         m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY;
 557
 558         r = dns_trust_anchor_load(&m->trust_anchor);
 559         if (r < 0)
 560                 return r;
 561
 562         r = manager_parse_config_file(m);
 563         if (r < 0)
 564                 return r;
 565
 566         r = sd_event_default(&m->event);
 567         if (r < 0)
 568                 return r;
 569
 570         sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
 571         sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
 572
 573         sd_event_set_watchdog(m->event, true);
 574
 575         r = manager_watch_hostname(m);
 576         if (r < 0)
 577                 return r;
 578
 579         r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 580         if (r < 0)
 581                 return r;
 582
 583         r = manager_network_monitor_listen(m);
 584         if (r < 0)
 585                 return r;
 586
 587         r = manager_rtnl_listen(m);
 588         if (r < 0)
 589                 return r;
 590
 591         r = manager_connect_bus(m);
 592         if (r < 0)
 593                 return r;
 594
 595         (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m);
 596         (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m);
 597
 598         manager_cleanup_saved_user(m);
 599
 600         *ret = m;
 601         m = NULL;
 602
 603         return 0;
 604 }
 605
 606 int manager_start(Manager *m) {
 607         int r;
 608
 609         assert(m);
 610
 611         r = manager_dns_stub_start(m);
 612         if (r < 0)
 613                 return r;
 614
 615         return 0;
 616 }
 617
 618 Manager *manager_free(Manager *m) {
 619         Link *l;
 620
 621         if (!m)
 622                 return NULL;
 623
 624         dns_server_unlink_all(m->dns_servers);
 625         dns_server_unlink_all(m->fallback_dns_servers);
 626         dns_search_domain_unlink_all(m->search_domains);
 627
 628         while ((l = hashmap_first(m->links)))
 629                link_free(l);
 630
 631         while (m->dns_queries)
 632                 dns_query_free(m->dns_queries);
 633
 634         dns_scope_free(m->unicast_scope);
 635
 636         /* At this point only orphaned streams should remain. All others should have been freed already by their
 637          * owners */
 638         while (m->dns_streams)
 639                 dns_stream_unref(m->dns_streams);
 640
 641         hashmap_free(m->links);
 642         hashmap_free(m->dns_transactions);
 643
 644         sd_event_source_unref(m->network_event_source);
 645         sd_network_monitor_unref(m->network_monitor);
 646
 647         sd_netlink_unref(m->rtnl);
 648         sd_event_source_unref(m->rtnl_event_source);
 649
 650         manager_llmnr_stop(m);
 651         manager_mdns_stop(m);
 652         manager_dns_stub_stop(m);
 653
 654         sd_bus_slot_unref(m->prepare_for_sleep_slot);
 655         sd_event_source_unref(m->bus_retry_event_source);
 656         sd_bus_unref(m->bus);
 657
 658         sd_event_source_unref(m->sigusr1_event_source);
 659         sd_event_source_unref(m->sigusr2_event_source);
 660
 661         sd_event_unref(m->event);
 662
 663         dns_resource_key_unref(m->llmnr_host_ipv4_key);
 664         dns_resource_key_unref(m->llmnr_host_ipv6_key);
 665         dns_resource_key_unref(m->mdns_host_ipv4_key);
 666         dns_resource_key_unref(m->mdns_host_ipv6_key);
 667
 668         sd_event_source_unref(m->hostname_event_source);
 669         safe_close(m->hostname_fd);
 670
 671         free(m->full_hostname);
 672         free(m->llmnr_hostname);
 673         free(m->mdns_hostname);
 674
 675         dns_trust_anchor_flush(&m->trust_anchor);
 676         manager_etc_hosts_flush(m);
 677
 678         return mfree(m);
 679 }
 680
 681 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 682         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 683         union {
 684                 struct cmsghdr header; /* For alignment */
 685                 uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 686                                + CMSG_SPACE(int) /* ttl/hoplimit */
 687                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
 688         } control;
 689         union sockaddr_union sa;
 690         struct msghdr mh = {};
 691         struct cmsghdr *cmsg;
 692         struct iovec iov;
 693         ssize_t ms, l;
 694         int r;
 695
 696         assert(m);
 697         assert(fd >= 0);
 698         assert(ret);
 699
 700         ms = next_datagram_size_fd(fd);
 701         if (ms < 0)
 702                 return ms;
 703
 704         r = dns_packet_new(&p, protocol, ms);
 705         if (r < 0)
 706                 return r;
 707
 708         iov.iov_base = DNS_PACKET_DATA(p);
 709         iov.iov_len = p->allocated;
 710
 711         mh.msg_name = &sa.sa;
 712         mh.msg_namelen = sizeof(sa);
 713         mh.msg_iov = &iov;
 714         mh.msg_iovlen = 1;
 715         mh.msg_control = &control;
 716         mh.msg_controllen = sizeof(control);
 717
 718         l = recvmsg(fd, &mh, 0);
 719         if (l == 0)
 720                 return 0;
 721         if (l < 0) {
 722                 if (errno == EAGAIN || errno == EINTR)
 723                         return 0;
 724
 725                 return -errno;
 726         }
 727
 728         assert(!(mh.msg_flags & MSG_CTRUNC));
 729         assert(!(mh.msg_flags & MSG_TRUNC));
 730
 731         p->size = (size_t) l;
 732
 733         p->family = sa.sa.sa_family;
 734         p->ipproto = IPPROTO_UDP;
 735         if (p->family == AF_INET) {
 736                 p->sender.in = sa.in.sin_addr;
 737                 p->sender_port = be16toh(sa.in.sin_port);
 738         } else if (p->family == AF_INET6) {
 739                 p->sender.in6 = sa.in6.sin6_addr;
 740                 p->sender_port = be16toh(sa.in6.sin6_port);
 741                 p->ifindex = sa.in6.sin6_scope_id;
 742         } else
 743                 return -EAFNOSUPPORT;
 744
 745         CMSG_FOREACH(cmsg, &mh) {
 746
 747                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 748                         assert(p->family == AF_INET6);
 749
 750                         switch (cmsg->cmsg_type) {
 751
 752                         case IPV6_PKTINFO: {
 753                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 754
 755                                 if (p->ifindex <= 0)
 756                                         p->ifindex = i->ipi6_ifindex;
 757
 758                                 p->destination.in6 = i->ipi6_addr;
 759                                 break;
 760                         }
 761
 762                         case IPV6_HOPLIMIT:
 763                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 764                                 break;
 765
 766                         }
 767                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 768                         assert(p->family == AF_INET);
 769
 770                         switch (cmsg->cmsg_type) {
 771
 772                         case IP_PKTINFO: {
 773                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 774
 775                                 if (p->ifindex <= 0)
 776                                         p->ifindex = i->ipi_ifindex;
 777
 778                                 p->destination.in = i->ipi_addr;
 779                                 break;
 780                         }
 781
 782                         case IP_TTL:
 783                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 784                                 break;
 785                         }
 786                 }
 787         }
 788
 789         /* The Linux kernel sets the interface index to the loopback
 790          * device if the packet came from the local host since it
 791          * avoids the routing table in such a case. Let's unset the
 792          * interface index in such a case. */
 793         if (p->ifindex == LOOPBACK_IFINDEX)
 794                 p->ifindex = 0;
 795
 796         if (protocol != DNS_PROTOCOL_DNS) {
 797                 /* If we don't know the interface index still, we look for the
 798                  * first local interface with a matching address. Yuck! */
 799                 if (p->ifindex <= 0)
 800                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 801         }
 802
 803         *ret = p;
 804         p = NULL;
 805
 806         return 1;
 807 }
 808
 809 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
 810         int r;
 811
 812         assert(fd >= 0);
 813         assert(mh);
 814
 815         for (;;) {
 816                 if (sendmsg(fd, mh, flags) >= 0)
 817                         return 0;
 818
 819                 if (errno == EINTR)
 820                         continue;
 821
 822                 if (errno != EAGAIN)
 823                         return -errno;
 824
 825                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 826                 if (r < 0)
 827                         return r;
 828                 if (r == 0)
 829                         return -ETIMEDOUT;
 830         }
 831 }
 832
 833 static int write_loop(int fd, void *message, size_t length) {
 834         int r;
 835
 836         assert(fd >= 0);
 837         assert(message);
 838
 839         for (;;) {
 840                 if (write(fd, message, length) >= 0)
 841                         return 0;
 842
 843                 if (errno == EINTR)
 844                         continue;
 845
 846                 if (errno != EAGAIN)
 847                         return -errno;
 848
 849                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 850                 if (r < 0)
 851                         return r;
 852                 if (r == 0)
 853                         return -ETIMEDOUT;
 854         }
 855 }
 856
 857 int manager_write(Manager *m, int fd, DnsPacket *p) {
 858         int r;
 859
 860         log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
 861
 862         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
 863         if (r < 0)
 864                 return r;
 865
 866         return 0;
 867 }
 868
 869 static int manager_ipv4_send(
 870                 Manager *m,
 871                 int fd,
 872                 int ifindex,
 873                 const struct in_addr *destination,
 874                 uint16_t port,
 875                 const struct in_addr *source,
 876                 DnsPacket *p) {
 877         union sockaddr_union sa = {
 878                 .in.sin_family = AF_INET,
 879         };
 880         union {
 881                 struct cmsghdr header; /* For alignment */
 882                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
 883         } control;
 884         struct msghdr mh = {};
 885         struct iovec iov;
 886
 887         assert(m);
 888         assert(fd >= 0);
 889         assert(destination);
 890         assert(port > 0);
 891         assert(p);
 892
 893         iov.iov_base = DNS_PACKET_DATA(p);
 894         iov.iov_len = p->size;
 895
 896         sa.in.sin_addr = *destination;
 897         sa.in.sin_port = htobe16(port),
 898
 899         mh.msg_iov = &iov;
 900         mh.msg_iovlen = 1;
 901         mh.msg_name = &sa.sa;
 902         mh.msg_namelen = sizeof(sa.in);
 903
 904         if (ifindex > 0) {
 905                 struct cmsghdr *cmsg;
 906                 struct in_pktinfo *pi;
 907
 908                 zero(control);
 909
 910                 mh.msg_control = &control;
 911                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
 912
 913                 cmsg = CMSG_FIRSTHDR(&mh);
 914                 cmsg->cmsg_len = mh.msg_controllen;
 915                 cmsg->cmsg_level = IPPROTO_IP;
 916                 cmsg->cmsg_type = IP_PKTINFO;
 917
 918                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
 919                 pi->ipi_ifindex = ifindex;
 920
 921                 if (source)
 922                         pi->ipi_spec_dst = *source;
 923         }
 924
 925         return sendmsg_loop(fd, &mh, 0);
 926 }
 927
 928 static int manager_ipv6_send(
 929                 Manager *m,
 930                 int fd,
 931                 int ifindex,
 932                 const struct in6_addr *destination,
 933                 uint16_t port,
 934                 const struct in6_addr *source,
 935                 DnsPacket *p) {
 936
 937         union sockaddr_union sa = {
 938                 .in6.sin6_family = AF_INET6,
 939         };
 940         union {
 941                 struct cmsghdr header; /* For alignment */
 942                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 943         } control;
 944         struct msghdr mh = {};
 945         struct iovec iov;
 946
 947         assert(m);
 948         assert(fd >= 0);
 949         assert(destination);
 950         assert(port > 0);
 951         assert(p);
 952
 953         iov.iov_base = DNS_PACKET_DATA(p);
 954         iov.iov_len = p->size;
 955
 956         sa.in6.sin6_addr = *destination;
 957         sa.in6.sin6_port = htobe16(port),
 958         sa.in6.sin6_scope_id = ifindex;
 959
 960         mh.msg_iov = &iov;
 961         mh.msg_iovlen = 1;
 962         mh.msg_name = &sa.sa;
 963         mh.msg_namelen = sizeof(sa.in6);
 964
 965         if (ifindex > 0) {
 966                 struct cmsghdr *cmsg;
 967                 struct in6_pktinfo *pi;
 968
 969                 zero(control);
 970
 971                 mh.msg_control = &control;
 972                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
 973
 974                 cmsg = CMSG_FIRSTHDR(&mh);
 975                 cmsg->cmsg_len = mh.msg_controllen;
 976                 cmsg->cmsg_level = IPPROTO_IPV6;
 977                 cmsg->cmsg_type = IPV6_PKTINFO;
 978
 979                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 980                 pi->ipi6_ifindex = ifindex;
 981
 982                 if (source)
 983                         pi->ipi6_addr = *source;
 984         }
 985
 986         return sendmsg_loop(fd, &mh, 0);
 987 }
 988
 989 int manager_send(
 990                 Manager *m,
 991                 int fd,
 992                 int ifindex,
 993                 int family,
 994                 const union in_addr_union *destination,
 995                 uint16_t port,
 996                 const union in_addr_union *source,
 997                 DnsPacket *p) {
 998
 999         assert(m);
1000         assert(fd >= 0);
1001         assert(destination);
1002         assert(port > 0);
1003         assert(p);
1004
1005         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));
1006
1007         if (family == AF_INET)
1008                 return manager_ipv4_send(m, fd, ifindex, &destination->in, port, &source->in, p);
1009         if (family == AF_INET6)
1010                 return manager_ipv6_send(m, fd, ifindex, &destination->in6, port, &source->in6, p);
1011
1012         return -EAFNOSUPPORT;
1013 }
1014
1015 uint32_t manager_find_mtu(Manager *m) {
1016         uint32_t mtu = 0;
1017         Link *l;
1018         Iterator i;
1019
1020         /* If we don't know on which link a DNS packet would be
1021          * delivered, let's find the largest MTU that works on all
1022          * interfaces we know of */
1023
1024         HASHMAP_FOREACH(l, m->links, i) {
1025                 if (l->mtu <= 0)
1026                         continue;
1027
1028                 if (mtu <= 0 || l->mtu < mtu)
1029                         mtu = l->mtu;
1030         }
1031
1032         return mtu;
1033 }
1034
1035 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
1036         LinkAddress *a;
1037
1038         assert(m);
1039
1040         a = manager_find_link_address(m, family, in_addr);
1041         if (a)
1042                 return a->link->ifindex;
1043
1044         return 0;
1045 }
1046
1047 void manager_refresh_rrs(Manager *m) {
1048         Iterator i;
1049         Link *l;
1050
1051         assert(m);
1052
1053         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
1054         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
1055         m->mdns_host_ipv4_key = dns_resource_key_unref(m->mdns_host_ipv4_key);
1056         m->mdns_host_ipv6_key = dns_resource_key_unref(m->mdns_host_ipv6_key);
1057
1058         HASHMAP_FOREACH(l, m->links, i) {
1059                 link_add_rrs(l, true);
1060                 link_add_rrs(l, false);
1061         }
1062 }
1063
1064 int manager_next_hostname(Manager *m) {
1065         const char *p;
1066         uint64_t u, a;
1067         char *h, *k;
1068         int r;
1069
1070         assert(m);
1071
1072         p = strchr(m->llmnr_hostname, 0);
1073         assert(p);
1074
1075         while (p > m->llmnr_hostname) {
1076                 if (!strchr("0123456789", p[-1]))
1077                         break;
1078
1079                 p--;
1080         }
1081
1082         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
1083                 u = 1;
1084
1085         /* Add a random number to the old value. This way we can avoid
1086          * that two hosts pick the same hostname, win on IPv4 and lose
1087          * on IPv6 (or vice versa), and pick the same hostname
1088          * replacement hostname, ad infinitum. We still want the
1089          * numbers to go up monotonically, hence we just add a random
1090          * value 1..10 */
1091
1092         random_bytes(&a, sizeof(a));
1093         u += 1 + a % 10;
1094
1095         if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0)
1096                 return -ENOMEM;
1097
1098         r = dns_name_concat(h, "local", &k);
1099         if (r < 0) {
1100                 free(h);
1101                 return r;
1102         }
1103
1104         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1105
1106         free(m->llmnr_hostname);
1107         m->llmnr_hostname = h;
1108
1109         free(m->mdns_hostname);
1110         m->mdns_hostname = k;
1111
1112         manager_refresh_rrs(m);
1113
1114         return 0;
1115 }
1116
1117 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1118         Iterator i;
1119         Link *l;
1120
1121         assert(m);
1122
1123         HASHMAP_FOREACH(l, m->links, i) {
1124                 LinkAddress *a;
1125
1126                 a = link_find_address(l, family, in_addr);
1127                 if (a)
1128                         return a;
1129         }
1130
1131         return NULL;
1132 }
1133
1134 bool manager_our_packet(Manager *m, DnsPacket *p) {
1135         assert(m);
1136         assert(p);
1137
1138         return !!manager_find_link_address(m, p->family, &p->sender);
1139 }
1140
1141 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1142         Link *l;
1143
1144         assert(m);
1145         assert(p);
1146
1147         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1148         if (!l)
1149                 return NULL;
1150
1151         switch (p->protocol) {
1152         case DNS_PROTOCOL_LLMNR:
1153                 if (p->family == AF_INET)
1154                         return l->llmnr_ipv4_scope;
1155                 else if (p->family == AF_INET6)
1156                         return l->llmnr_ipv6_scope;
1157
1158                 break;
1159
1160         case DNS_PROTOCOL_MDNS:
1161                 if (p->family == AF_INET)
1162                         return l->mdns_ipv4_scope;
1163                 else if (p->family == AF_INET6)
1164                         return l->mdns_ipv6_scope;
1165
1166                 break;
1167
1168         default:
1169                 break;
1170         }
1171
1172         return NULL;
1173 }
1174
1175 void manager_verify_all(Manager *m) {
1176         DnsScope *s;
1177
1178         assert(m);
1179
1180         LIST_FOREACH(scopes, s, m->dns_scopes)
1181                 dns_zone_verify_all(&s->zone);
1182 }
1183
1184 int manager_is_own_hostname(Manager *m, const char *name) {
1185         int r;
1186
1187         assert(m);
1188         assert(name);
1189
1190         if (m->llmnr_hostname) {
1191                 r = dns_name_equal(name, m->llmnr_hostname);
1192                 if (r != 0)
1193                         return r;
1194         }
1195
1196         if (m->mdns_hostname) {
1197                 r = dns_name_equal(name, m->mdns_hostname);
1198                 if (r != 0)
1199                         return r;
1200         }
1201
1202         if (m->full_hostname)
1203                 return dns_name_equal(name, m->full_hostname);
1204
1205         return 0;
1206 }
1207
1208 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1209         DnsServer *s;
1210         Iterator i;
1211         Link *l;
1212         int r;
1213
1214         assert(m);
1215         assert(dns);
1216
1217         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1218         if (r < 0)
1219                 return r;
1220
1221         /* First add the system-wide servers and domains */
1222         LIST_FOREACH(servers, s, m->dns_servers) {
1223                 r = ordered_set_put(*dns, s);
1224                 if (r == -EEXIST)
1225                         continue;
1226                 if (r < 0)
1227                         return r;
1228         }
1229
1230         /* Then, add the per-link servers */
1231         HASHMAP_FOREACH(l, m->links, i) {
1232                 LIST_FOREACH(servers, s, l->dns_servers) {
1233                         r = ordered_set_put(*dns, s);
1234                         if (r == -EEXIST)
1235                                 continue;
1236                         if (r < 0)
1237                                 return r;
1238                 }
1239         }
1240
1241         /* If we found nothing, add the fallback servers */
1242         if (ordered_set_isempty(*dns)) {
1243                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1244                         r = ordered_set_put(*dns, s);
1245                         if (r == -EEXIST)
1246                                 continue;
1247                         if (r < 0)
1248                                 return r;
1249                 }
1250         }
1251
1252         return 0;
1253 }
1254
1255 /* filter_route is a tri-state:
1256  *   < 0: no filtering
1257  *   = 0 or false: return only domains which should be used for searching
1258  *   > 0 or true: return only domains which are for routing only
1259  */
1260 int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) {
1261         DnsSearchDomain *d;
1262         Iterator i;
1263         Link *l;
1264         int r;
1265
1266         assert(m);
1267         assert(domains);
1268
1269         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1270         if (r < 0)
1271                 return r;
1272
1273         LIST_FOREACH(domains, d, m->search_domains) {
1274
1275                 if (filter_route >= 0 &&
1276                     d->route_only != !!filter_route)
1277                         continue;
1278
1279                 r = ordered_set_put(*domains, d->name);
1280                 if (r == -EEXIST)
1281                         continue;
1282                 if (r < 0)
1283                         return r;
1284         }
1285
1286         HASHMAP_FOREACH(l, m->links, i) {
1287
1288                 LIST_FOREACH(domains, d, l->search_domains) {
1289
1290                         if (filter_route >= 0 &&
1291                             d->route_only != !!filter_route)
1292                                 continue;
1293
1294                         r = ordered_set_put(*domains, d->name);
1295                         if (r == -EEXIST)
1296                                 continue;
1297                         if (r < 0)
1298                                 return r;
1299                 }
1300         }
1301
1302         return 0;
1303 }
1304
1305 DnssecMode manager_get_dnssec_mode(Manager *m) {
1306         assert(m);
1307
1308         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1309                 return m->dnssec_mode;
1310
1311         return DNSSEC_NO;
1312 }
1313
1314 bool manager_dnssec_supported(Manager *m) {
1315         DnsServer *server;
1316         Iterator i;
1317         Link *l;
1318
1319         assert(m);
1320
1321         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1322                 return false;
1323
1324         server = manager_get_dns_server(m);
1325         if (server && !dns_server_dnssec_supported(server))
1326                 return false;
1327
1328         HASHMAP_FOREACH(l, m->links, i)
1329                 if (!link_dnssec_supported(l))
1330                         return false;
1331
1332         return true;
1333 }
1334
1335 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1336
1337         assert(verdict >= 0);
1338         assert(verdict < _DNSSEC_VERDICT_MAX);
1339
1340         if (log_get_max_level() >= LOG_DEBUG) {
1341                 char s[DNS_RESOURCE_KEY_STRING_MAX];
1342
1343                 log_debug("Found verdict for lookup %s: %s",
1344                           dns_resource_key_to_string(key, s, sizeof s),
1345                           dnssec_verdict_to_string(verdict));
1346         }
1347
1348         m->n_dnssec_verdict[verdict]++;
1349 }
1350
1351 bool manager_routable(Manager *m, int family) {
1352         Iterator i;
1353         Link *l;
1354
1355         assert(m);
1356
1357         /* Returns true if the host has at least one interface with a routable address of the specified type */
1358
1359         HASHMAP_FOREACH(l, m->links, i)
1360                 if (link_relevant(l, family, false))
1361                         return true;
1362
1363         return false;
1364 }
1365
1366 void manager_flush_caches(Manager *m) {
1367         DnsScope *scope;
1368
1369         assert(m);
1370
1371         LIST_FOREACH(scopes, scope, m->dns_scopes)
1372                 dns_cache_flush(&scope->cache);
1373
1374         log_info("Flushed all caches.");
1375 }
1376
1377 void manager_cleanup_saved_user(Manager *m) {
1378         _cleanup_closedir_ DIR *d = NULL;
1379         struct dirent *de;
1380         int r;
1381
1382         assert(m);
1383
1384         /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface
1385          * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can
1386          * be restarted without losing this data. */
1387
1388         d = opendir("/run/systemd/resolve/netif/");
1389         if (!d) {
1390                 if (errno == ENOENT)
1391                         return;
1392
1393                 log_warning_errno(errno, "Failed to open interface directory: %m");
1394                 return;
1395         }
1396
1397         FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) {
1398                 _cleanup_free_ char *p = NULL;
1399                 int ifindex;
1400                 Link *l;
1401
1402                 if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG))
1403                         continue;
1404
1405                 if (dot_or_dot_dot(de->d_name))
1406                         continue;
1407
1408                 r = parse_ifindex(de->d_name, &ifindex);
1409                 if (r < 0) /* Probably some temporary file from a previous run. Delete it */
1410                         goto rm;
1411
1412                 l = hashmap_get(m->links, INT_TO_PTR(ifindex));
1413                 if (!l) /* link vanished */
1414                         goto rm;
1415
1416                 if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */
1417                         goto rm;
1418
1419                 continue;
1420
1421         rm:
1422                 p = strappend("/run/systemd/resolve/netif/", de->d_name);
1423                 if (!p) {
1424                         log_oom();
1425                         return;
1426                 }
1427
1428                 (void) unlink(p);
1429         }
1430 }