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