src/resolve/resolved-manager.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2014 Tom Gundersen <teg@jklm.no>
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20  ***/
  21
  22 #include <arpa/inet.h>
  23 #include <resolv.h>
  24 #include <net/if.h>
  25 #include <sys/ioctl.h>
  26 #include <sys/poll.h>
  27 #include <netinet/in.h>
  28
  29 #include "rtnl-util.h"
  30 #include "event-util.h"
  31 #include "network-util.h"
  32 #include "network-internal.h"
  33 #include "conf-parser.h"
  34 #include "socket-util.h"
  35 #include "af-list.h"
  36 #include "utf8.h"
  37 #include "fileio-label.h"
  38
  39 #include "resolved-dns-domain.h"
  40 #include "resolved-conf.h"
  41 #include "resolved-bus.h"
  42 #include "resolved-manager.h"
  43
  44 #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
  45
  46 static int manager_process_link(sd_rtnl *rtnl, sd_rtnl_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_rtnl_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_update_rtnl(l, mm);
  78                 if (r < 0)
  79                         goto fail;
  80
  81                 r = link_update_monitor(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_free(l);
  95                 }
  96
  97                 break;
  98         }
  99
 100         return 0;
 101
 102 fail:
 103         log_warning_errno(r, "Failed to process RTNL link message: %m");
 104         return 0;
 105 }
 106
 107 static int manager_process_address(sd_rtnl *rtnl, sd_rtnl_message *mm, void *userdata) {
 108         Manager *m = userdata;
 109         union in_addr_union address;
 110         uint16_t type;
 111         int r, ifindex, family;
 112         LinkAddress *a;
 113         Link *l;
 114
 115         assert(rtnl);
 116         assert(mm);
 117         assert(m);
 118
 119         r = sd_rtnl_message_get_type(mm, &type);
 120         if (r < 0)
 121                 goto fail;
 122
 123         r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
 124         if (r < 0)
 125                 goto fail;
 126
 127         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
 128         if (!l)
 129                 return 0;
 130
 131         r = sd_rtnl_message_addr_get_family(mm, &family);
 132         if (r < 0)
 133                 goto fail;
 134
 135         switch (family) {
 136
 137         case AF_INET:
 138                 r = sd_rtnl_message_read_in_addr(mm, IFA_LOCAL, &address.in);
 139                 if (r < 0) {
 140                         r = sd_rtnl_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
 141                         if (r < 0)
 142                                 goto fail;
 143                 }
 144
 145                 break;
 146
 147         case AF_INET6:
 148                 r = sd_rtnl_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
 149                 if (r < 0) {
 150                         r = sd_rtnl_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
 151                         if (r < 0)
 152                                 goto fail;
 153                 }
 154
 155                 break;
 156
 157         default:
 158                 return 0;
 159         }
 160
 161         a = link_find_address(l, family, &address);
 162
 163         switch (type) {
 164
 165         case RTM_NEWADDR:
 166
 167                 if (!a) {
 168                         r = link_address_new(l, &a, family, &address);
 169                         if (r < 0)
 170                                 return r;
 171                 }
 172
 173                 r = link_address_update_rtnl(a, mm);
 174                 if (r < 0)
 175                         return r;
 176
 177                 break;
 178
 179         case RTM_DELADDR:
 180                 if (a)
 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_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
 194         sd_rtnl_message *i;
 195         int r;
 196
 197         assert(m);
 198
 199         /* First, subscibe to interfaces coming and going */
 200         r = sd_rtnl_open(&m->rtnl, 3, RTNLGRP_LINK, RTNLGRP_IPV4_IFADDR, RTNLGRP_IPV6_IFADDR);
 201         if (r < 0)
 202                 return r;
 203
 204         r = sd_rtnl_attach_event(m->rtnl, m->event, 0);
 205         if (r < 0)
 206                 return r;
 207
 208         r = sd_rtnl_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);
 209         if (r < 0)
 210                 return r;
 211
 212         r = sd_rtnl_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);
 213         if (r < 0)
 214                 return r;
 215
 216         r = sd_rtnl_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);
 217         if (r < 0)
 218                 return r;
 219
 220         r = sd_rtnl_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_rtnl_message_request_dump(req, true);
 230         if (r < 0)
 231                 return r;
 232
 233         r = sd_rtnl_call(m->rtnl, req, 0, &reply);
 234         if (r < 0)
 235                 return r;
 236
 237         for (i = reply; i; i = sd_rtnl_message_next(i)) {
 238                 r = manager_process_link(m->rtnl, i, m);
 239                 if (r < 0)
 240                         return r;
 241         }
 242
 243         req = sd_rtnl_message_unref(req);
 244         reply = sd_rtnl_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_rtnl_message_request_dump(req, true);
 252         if (r < 0)
 253                 return r;
 254
 255         r = sd_rtnl_call(m->rtnl, req, 0, &reply);
 256         if (r < 0)
 257                 return r;
 258
 259         for (i = reply; i; i = sd_rtnl_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_monitor(l);
 280                 if (r < 0)
 281                         log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
 282         }
 283
 284         r = manager_write_resolv_conf(m);
 285         if (r < 0)
 286                 log_warning_errno(r, "Could not update resolv.conf: %m");
 287
 288         return 0;
 289 }
 290
 291 static int manager_network_monitor_listen(Manager *m) {
 292         int r, fd, events;
 293
 294         assert(m);
 295
 296         r = sd_network_monitor_new(&m->network_monitor, NULL);
 297         if (r < 0)
 298                 return r;
 299
 300         fd = sd_network_monitor_get_fd(m->network_monitor);
 301         if (fd < 0)
 302                 return fd;
 303
 304         events = sd_network_monitor_get_events(m->network_monitor);
 305         if (events < 0)
 306                 return events;
 307
 308         r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m);
 309         if (r < 0)
 310                 return r;
 311
 312         return 0;
 313 }
 314
 315 static int determine_hostname(char **ret) {
 316         _cleanup_free_ char *h = NULL, *n = NULL;
 317         int r;
 318
 319         assert(ret);
 320
 321         h = gethostname_malloc();
 322         if (!h)
 323                 return log_oom();
 324
 325         if (!utf8_is_valid(h)) {
 326                 log_error("System hostname is not UTF-8 clean.");
 327                 return -EINVAL;
 328         }
 329
 330         r = dns_name_normalize(h, &n);
 331         if (r < 0) {
 332                 log_error("System hostname '%s' cannot be normalized.", h);
 333                 return r;
 334         }
 335
 336         *ret = n;
 337         n = NULL;
 338
 339         return 0;
 340 }
 341
 342 static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
 343         _cleanup_free_ char *h = NULL;
 344         Manager *m = userdata;
 345         int r;
 346
 347         assert(m);
 348
 349         r = determine_hostname(&h);
 350         if (r < 0)
 351                 return 0; /* ignore invalid hostnames */
 352
 353         if (streq(h, m->hostname))
 354                 return 0;
 355
 356         log_info("System hostname changed to '%s'.", h);
 357         free(m->hostname);
 358         m->hostname = h;
 359         h = NULL;
 360
 361         manager_refresh_rrs(m);
 362
 363         return 0;
 364 }
 365
 366 static int manager_watch_hostname(Manager *m) {
 367         int r;
 368
 369         assert(m);
 370
 371         m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY);
 372         if (m->hostname_fd < 0) {
 373                 log_warning("Failed to watch hostname: %m");
 374                 return 0;
 375         }
 376
 377         r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
 378         if (r < 0) {
 379                 if (r == -EPERM)
 380                         /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
 381                         m->hostname_fd = safe_close(m->hostname_fd);
 382                 else
 383                         return log_error_errno(r, "Failed to add hostname event source: %m");
 384         }
 385
 386         r = determine_hostname(&m->hostname);
 387         if (r < 0) {
 388                 log_info("Defaulting to hostname 'linux'.");
 389                 m->hostname = strdup("linux");
 390                 if (!m->hostname)
 391                         return log_oom();
 392         } else
 393                 log_info("Using system hostname '%s'.", m->hostname);
 394
 395         return 0;
 396 }
 397
 398 static void manager_llmnr_stop(Manager *m) {
 399         assert(m);
 400
 401         m->llmnr_ipv4_udp_event_source = sd_event_source_unref(m->llmnr_ipv4_udp_event_source);
 402         m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd);
 403
 404         m->llmnr_ipv6_udp_event_source = sd_event_source_unref(m->llmnr_ipv6_udp_event_source);
 405         m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd);
 406
 407         m->llmnr_ipv4_tcp_event_source = sd_event_source_unref(m->llmnr_ipv4_tcp_event_source);
 408         m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd);
 409
 410         m->llmnr_ipv6_tcp_event_source = sd_event_source_unref(m->llmnr_ipv6_tcp_event_source);
 411         m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd);
 412 }
 413
 414 static int manager_llmnr_start(Manager *m) {
 415         int r;
 416
 417         assert(m);
 418
 419         if (m->llmnr_support == SUPPORT_NO)
 420                 return 0;
 421
 422         r = manager_llmnr_ipv4_udp_fd(m);
 423         if (r == -EADDRINUSE)
 424                 goto eaddrinuse;
 425         if (r < 0)
 426                 return r;
 427
 428         r = manager_llmnr_ipv4_tcp_fd(m);
 429         if (r == -EADDRINUSE)
 430                 goto eaddrinuse;
 431         if (r < 0)
 432                 return r;
 433
 434         if (socket_ipv6_is_supported()) {
 435                 r = manager_llmnr_ipv6_udp_fd(m);
 436                 if (r == -EADDRINUSE)
 437                         goto eaddrinuse;
 438                 if (r < 0)
 439                         return r;
 440
 441                 r = manager_llmnr_ipv6_tcp_fd(m);
 442                 if (r == -EADDRINUSE)
 443                         goto eaddrinuse;
 444                 if (r < 0)
 445                         return r;
 446         }
 447
 448         return 0;
 449
 450 eaddrinuse:
 451         log_warning("There appears to be another LLMNR responder running. Turning off LLMNR support.");
 452         m->llmnr_support = SUPPORT_NO;
 453         manager_llmnr_stop(m);
 454
 455         return 0;
 456 }
 457
 458 int manager_new(Manager **ret) {
 459         _cleanup_(manager_freep) Manager *m = NULL;
 460         int r;
 461
 462         assert(ret);
 463
 464         m = new0(Manager, 1);
 465         if (!m)
 466                 return -ENOMEM;
 467
 468         m->dns_ipv4_fd = m->dns_ipv6_fd = -1;
 469         m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
 470         m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
 471         m->hostname_fd = -1;
 472
 473         m->llmnr_support = SUPPORT_YES;
 474         m->read_resolv_conf = true;
 475
 476         r = manager_parse_dns_server(m, DNS_SERVER_FALLBACK, DNS_SERVERS);
 477         if (r < 0)
 478                 return r;
 479
 480         r = sd_event_default(&m->event);
 481         if (r < 0)
 482                 return r;
 483
 484         sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
 485         sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
 486
 487         sd_event_set_watchdog(m->event, true);
 488
 489         r = manager_watch_hostname(m);
 490         if (r < 0)
 491                 return r;
 492
 493         r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 494         if (r < 0)
 495                 return r;
 496
 497         r = manager_network_monitor_listen(m);
 498         if (r < 0)
 499                 return r;
 500
 501         r = manager_rtnl_listen(m);
 502         if (r < 0)
 503                 return r;
 504
 505         r = manager_connect_bus(m);
 506         if (r < 0)
 507                 return r;
 508
 509         *ret = m;
 510         m = NULL;
 511
 512         return 0;
 513 }
 514
 515 int manager_start(Manager *m) {
 516         int r;
 517
 518         assert(m);
 519
 520         r = manager_llmnr_start(m);
 521         if (r < 0)
 522                 return r;
 523
 524         return 0;
 525 }
 526
 527 Manager *manager_free(Manager *m) {
 528         Link *l;
 529
 530         if (!m)
 531                 return NULL;
 532
 533         while ((l = hashmap_first(m->links)))
 534                link_free(l);
 535
 536         while (m->dns_queries)
 537                 dns_query_free(m->dns_queries);
 538
 539         dns_scope_free(m->unicast_scope);
 540
 541         manager_flush_dns_servers(m, DNS_SERVER_SYSTEM);
 542         manager_flush_dns_servers(m, DNS_SERVER_FALLBACK);
 543
 544         hashmap_free(m->links);
 545         hashmap_free(m->dns_transactions);
 546
 547         sd_event_source_unref(m->network_event_source);
 548         sd_network_monitor_unref(m->network_monitor);
 549
 550         sd_event_source_unref(m->dns_ipv4_event_source);
 551         sd_event_source_unref(m->dns_ipv6_event_source);
 552         safe_close(m->dns_ipv4_fd);
 553         safe_close(m->dns_ipv6_fd);
 554
 555         manager_llmnr_stop(m);
 556
 557         sd_bus_slot_unref(m->prepare_for_sleep_slot);
 558         sd_event_source_unref(m->bus_retry_event_source);
 559         sd_bus_unref(m->bus);
 560
 561         sd_event_unref(m->event);
 562
 563         dns_resource_key_unref(m->host_ipv4_key);
 564         dns_resource_key_unref(m->host_ipv6_key);
 565
 566         safe_close(m->hostname_fd);
 567         sd_event_source_unref(m->hostname_event_source);
 568         free(m->hostname);
 569
 570         free(m);
 571
 572         return NULL;
 573 }
 574
 575 int manager_read_resolv_conf(Manager *m) {
 576         _cleanup_fclose_ FILE *f = NULL;
 577         struct stat st, own;
 578         char line[LINE_MAX];
 579         DnsServer *s, *nx;
 580         usec_t t;
 581         int r;
 582
 583         assert(m);
 584
 585         /* Reads the system /etc/resolv.conf, if it exists and is not
 586          * symlinked to our own resolv.conf instance */
 587
 588         if (!m->read_resolv_conf)
 589                 return 0;
 590
 591         r = stat("/etc/resolv.conf", &st);
 592         if (r < 0) {
 593                 if (errno != ENOENT)
 594                         log_warning("Failed to open /etc/resolv.conf: %m");
 595                 r = -errno;
 596                 goto clear;
 597         }
 598
 599         /* Have we already seen the file? */
 600         t = timespec_load(&st.st_mtim);
 601         if (t == m->resolv_conf_mtime)
 602                 return 0;
 603
 604         m->resolv_conf_mtime = t;
 605
 606         /* Is it symlinked to our own file? */
 607         if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 &&
 608             st.st_dev == own.st_dev &&
 609             st.st_ino == own.st_ino) {
 610                 r = 0;
 611                 goto clear;
 612         }
 613
 614         f = fopen("/etc/resolv.conf", "re");
 615         if (!f) {
 616                 if (errno != ENOENT)
 617                         log_warning("Failed to open /etc/resolv.conf: %m");
 618                 r = -errno;
 619                 goto clear;
 620         }
 621
 622         if (fstat(fileno(f), &st) < 0) {
 623                 log_error("Failed to stat open file: %m");
 624                 r = -errno;
 625                 goto clear;
 626         }
 627
 628         LIST_FOREACH(servers, s, m->dns_servers)
 629                 s->marked = true;
 630
 631         FOREACH_LINE(line, f, r = -errno; goto clear) {
 632                 union in_addr_union address;
 633                 int family;
 634                 char *l;
 635                 const char *a;
 636
 637                 truncate_nl(line);
 638
 639                 l = strstrip(line);
 640                 if (*l == '#' || *l == ';')
 641                         continue;
 642
 643                 a = first_word(l, "nameserver");
 644                 if (!a)
 645                         continue;
 646
 647                 r = in_addr_from_string_auto(a, &family, &address);
 648                 if (r < 0) {
 649                         log_warning("Failed to parse name server %s.", a);
 650                         continue;
 651                 }
 652
 653                 LIST_FOREACH(servers, s, m->dns_servers)
 654                         if (s->family == family && in_addr_equal(family, &s->address, &address) > 0)
 655                                 break;
 656
 657                 if (s)
 658                         s->marked = false;
 659                 else {
 660                         r = dns_server_new(m, NULL, DNS_SERVER_SYSTEM, NULL, family, &address);
 661                         if (r < 0)
 662                                 goto clear;
 663                 }
 664         }
 665
 666         LIST_FOREACH_SAFE(servers, s, nx, m->dns_servers)
 667                 if (s->marked)
 668                         dns_server_free(s);
 669
 670         return 0;
 671
 672 clear:
 673         while (m->dns_servers)
 674                 dns_server_free(m->dns_servers);
 675
 676         return r;
 677 }
 678
 679 static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) {
 680         _cleanup_free_ char *t  = NULL;
 681         int r;
 682
 683         assert(s);
 684         assert(f);
 685         assert(count);
 686
 687         r = in_addr_to_string(s->family, &s->address, &t);
 688         if (r < 0) {
 689                 log_warning_errno(r, "Invalid DNS address. Ignoring: %m");
 690                 return;
 691         }
 692
 693         if (*count == MAXNS)
 694                 fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f);
 695
 696         fprintf(f, "nameserver %s\n", t);
 697         (*count) ++;
 698 }
 699
 700 static void write_resolv_conf_search(const char *domain, FILE *f,
 701                                      unsigned *count, unsigned *length) {
 702         assert(domain);
 703         assert(f);
 704         assert(length);
 705
 706         if (*count >= MAXDNSRCH ||
 707             *length + strlen(domain) > 256) {
 708                 if (*count == MAXDNSRCH)
 709                         fputs(" # Too many search domains configured, remaining ones ignored.", f);
 710                 if (*length <= 256)
 711                         fputs(" # Total length of all search domains is too long, remaining ones ignored.", f);
 712
 713                 return;
 714         }
 715
 716         fprintf(f, " %s", domain);
 717
 718         (*length) += strlen(domain);
 719         (*count) ++;
 720 }
 721
 722 static int write_resolv_conf_contents(FILE *f, Set *dns, Set *domains) {
 723         Iterator i;
 724
 725         fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n"
 726               "# Third party programs must not access this file directly, but\n"
 727               "# only through the symlink at /etc/resolv.conf. To manage\n"
 728               "# resolv.conf(5) in a different way, replace the symlink by a\n"
 729               "# static file or a different symlink.\n\n", f);
 730
 731         if (set_isempty(dns))
 732                 fputs("# No DNS servers known.\n", f);
 733         else {
 734                 DnsServer *s;
 735                 unsigned count = 0;
 736
 737                 SET_FOREACH(s, dns, i)
 738                         write_resolv_conf_server(s, f, &count);
 739         }
 740
 741         if (!set_isempty(domains)) {
 742                 unsigned length = 0, count = 0;
 743                 char *domain;
 744
 745                 fputs("search", f);
 746                 SET_FOREACH(domain, domains, i)
 747                         write_resolv_conf_search(domain, f, &count, &length);
 748                 fputs("\n", f);
 749         }
 750
 751         return fflush_and_check(f);
 752 }
 753
 754
 755 int manager_write_resolv_conf(Manager *m) {
 756         static const char path[] = "/run/systemd/resolve/resolv.conf";
 757         _cleanup_free_ char *temp_path = NULL;
 758         _cleanup_fclose_ FILE *f = NULL;
 759         _cleanup_set_free_ Set *dns = NULL, *domains = NULL;
 760         DnsServer *s;
 761         Iterator i;
 762         Link *l;
 763         int r;
 764
 765         assert(m);
 766
 767         /* Read the system /etc/resolv.conf first */
 768         manager_read_resolv_conf(m);
 769
 770         /* Add the full list to a set, to filter out duplicates */
 771         dns = set_new(&dns_server_hash_ops);
 772         if (!dns)
 773                 return -ENOMEM;
 774
 775         domains = set_new(&dns_name_hash_ops);
 776         if (!domains)
 777                 return -ENOMEM;
 778
 779         /* First add the system-wide servers */
 780         LIST_FOREACH(servers, s, m->dns_servers) {
 781                 r = set_put(dns, s);
 782                 if (r == -EEXIST)
 783                         continue;
 784                 if (r < 0)
 785                         return r;
 786         }
 787
 788         /* Then, add the per-link servers and domains */
 789         HASHMAP_FOREACH(l, m->links, i) {
 790                 char **domain;
 791
 792                 LIST_FOREACH(servers, s, l->dns_servers) {
 793                         r = set_put(dns, s);
 794                         if (r == -EEXIST)
 795                                 continue;
 796                         if (r < 0)
 797                                 return r;
 798                 }
 799
 800                 if (!l->unicast_scope)
 801                         continue;
 802
 803                 STRV_FOREACH(domain, l->unicast_scope->domains) {
 804                         r = set_put(domains, *domain);
 805                         if (r == -EEXIST)
 806                                 continue;
 807                         if (r < 0)
 808                                 return r;
 809                 }
 810         }
 811
 812         /* If we found nothing, add the fallback servers */
 813         if (set_isempty(dns)) {
 814                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
 815                         r = set_put(dns, s);
 816                         if (r == -EEXIST)
 817                                 continue;
 818                         if (r < 0)
 819                                 return r;
 820                 }
 821         }
 822
 823         r = fopen_temporary_label(path, path, &f, &temp_path);
 824         if (r < 0)
 825                 return r;
 826
 827         fchmod(fileno(f), 0644);
 828
 829         r = write_resolv_conf_contents(f, dns, domains);
 830         if (r < 0)
 831                 goto fail;
 832
 833         if (rename(temp_path, path) < 0) {
 834                 r = -errno;
 835                 goto fail;
 836         }
 837
 838         return 0;
 839
 840 fail:
 841         unlink(path);
 842         unlink(temp_path);
 843         return r;
 844 }
 845
 846 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 847         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 848         union {
 849                 struct cmsghdr header; /* For alignment */
 850                 uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 851                                + CMSG_SPACE(int) /* ttl/hoplimit */
 852                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
 853         } control;
 854         union sockaddr_union sa;
 855         struct msghdr mh = {};
 856         struct cmsghdr *cmsg;
 857         struct iovec iov;
 858         int ms = 0, r;
 859         ssize_t l;
 860
 861         assert(m);
 862         assert(fd >= 0);
 863         assert(ret);
 864
 865         r = ioctl(fd, FIONREAD, &ms);
 866         if (r < 0)
 867                 return -errno;
 868         if (ms < 0)
 869                 return -EIO;
 870
 871         r = dns_packet_new(&p, protocol, ms);
 872         if (r < 0)
 873                 return r;
 874
 875         iov.iov_base = DNS_PACKET_DATA(p);
 876         iov.iov_len = p->allocated;
 877
 878         mh.msg_name = &sa.sa;
 879         mh.msg_namelen = sizeof(sa);
 880         mh.msg_iov = &iov;
 881         mh.msg_iovlen = 1;
 882         mh.msg_control = &control;
 883         mh.msg_controllen = sizeof(control);
 884
 885         l = recvmsg(fd, &mh, 0);
 886         if (l < 0) {
 887                 if (errno == EAGAIN || errno == EINTR)
 888                         return 0;
 889
 890                 return -errno;
 891         }
 892
 893         if (l <= 0)
 894                 return -EIO;
 895
 896         assert(!(mh.msg_flags & MSG_CTRUNC));
 897         assert(!(mh.msg_flags & MSG_TRUNC));
 898
 899         p->size = (size_t) l;
 900
 901         p->family = sa.sa.sa_family;
 902         p->ipproto = IPPROTO_UDP;
 903         if (p->family == AF_INET) {
 904                 p->sender.in = sa.in.sin_addr;
 905                 p->sender_port = be16toh(sa.in.sin_port);
 906         } else if (p->family == AF_INET6) {
 907                 p->sender.in6 = sa.in6.sin6_addr;
 908                 p->sender_port = be16toh(sa.in6.sin6_port);
 909                 p->ifindex = sa.in6.sin6_scope_id;
 910         } else
 911                 return -EAFNOSUPPORT;
 912
 913         for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {
 914
 915                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 916                         assert(p->family == AF_INET6);
 917
 918                         switch (cmsg->cmsg_type) {
 919
 920                         case IPV6_PKTINFO: {
 921                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 922
 923                                 if (p->ifindex <= 0)
 924                                         p->ifindex = i->ipi6_ifindex;
 925
 926                                 p->destination.in6 = i->ipi6_addr;
 927                                 break;
 928                         }
 929
 930                         case IPV6_HOPLIMIT:
 931                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 932                                 break;
 933
 934                         }
 935                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 936                         assert(p->family == AF_INET);
 937
 938                         switch (cmsg->cmsg_type) {
 939
 940                         case IP_PKTINFO: {
 941                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 942
 943                                 if (p->ifindex <= 0)
 944                                         p->ifindex = i->ipi_ifindex;
 945
 946                                 p->destination.in = i->ipi_addr;
 947                                 break;
 948                         }
 949
 950                         case IP_TTL:
 951                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 952                                 break;
 953                         }
 954                 }
 955         }
 956
 957         /* The Linux kernel sets the interface index to the loopback
 958          * device if the packet came from the local host since it
 959          * avoids the routing table in such a case. Let's unset the
 960          * interface index in such a case. */
 961         if (p->ifindex == LOOPBACK_IFINDEX)
 962                 p->ifindex = 0;
 963
 964         /* If we don't know the interface index still, we look for the
 965          * first local interface with a matching address. Yuck! */
 966         if (p->ifindex <= 0)
 967                 p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 968
 969         *ret = p;
 970         p = NULL;
 971
 972         return 1;
 973 }
 974
 975 static int on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 976         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 977         DnsTransaction *t = NULL;
 978         Manager *m = userdata;
 979         int r;
 980
 981         r = manager_recv(m, fd, DNS_PROTOCOL_DNS, &p);
 982         if (r <= 0)
 983                 return r;
 984
 985         if (dns_packet_validate_reply(p) > 0) {
 986                 t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));
 987                 if (!t)
 988                         return 0;
 989
 990                 dns_transaction_process_reply(t, p);
 991
 992         } else
 993                 log_debug("Invalid DNS packet.");
 994
 995         return 0;
 996 }
 997
 998 int manager_dns_ipv4_fd(Manager *m) {
 999         const int one = 1;
1000         int r;
1001
1002         assert(m);
1003
1004         if (m->dns_ipv4_fd >= 0)
1005                 return m->dns_ipv4_fd;
1006
1007         m->dns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
1008         if (m->dns_ipv4_fd < 0)
1009                 return -errno;
1010
1011         r = setsockopt(m->dns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
1012         if (r < 0) {
1013                 r = -errno;
1014                 goto fail;
1015         }
1016
1017         r = sd_event_add_io(m->event, &m->dns_ipv4_event_source, m->dns_ipv4_fd, EPOLLIN, on_dns_packet, m);
1018         if (r < 0)
1019                 goto fail;
1020
1021         return m->dns_ipv4_fd;
1022
1023 fail:
1024         m->dns_ipv4_fd = safe_close(m->dns_ipv4_fd);
1025         return r;
1026 }
1027
1028 int manager_dns_ipv6_fd(Manager *m) {
1029         const int one = 1;
1030         int r;
1031
1032         assert(m);
1033
1034         if (m->dns_ipv6_fd >= 0)
1035                 return m->dns_ipv6_fd;
1036
1037         m->dns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
1038         if (m->dns_ipv6_fd < 0)
1039                 return -errno;
1040
1041         r = setsockopt(m->dns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
1042         if (r < 0) {
1043                 r = -errno;
1044                 goto fail;
1045         }
1046
1047         r = sd_event_add_io(m->event, &m->dns_ipv6_event_source, m->dns_ipv6_fd, EPOLLIN, on_dns_packet, m);
1048         if (r < 0)
1049                 goto fail;
1050
1051         return m->dns_ipv6_fd;
1052
1053 fail:
1054         m->dns_ipv6_fd = safe_close(m->dns_ipv6_fd);
1055         return r;
1056 }
1057
1058 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
1059         int r;
1060
1061         assert(fd >= 0);
1062         assert(mh);
1063
1064         for (;;) {
1065                 if (sendmsg(fd, mh, flags) >= 0)
1066                         return 0;
1067
1068                 if (errno == EINTR)
1069                         continue;
1070
1071                 if (errno != EAGAIN)
1072                         return -errno;
1073
1074                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
1075                 if (r < 0)
1076                         return r;
1077                 if (r == 0)
1078                         return -ETIMEDOUT;
1079         }
1080 }
1081
1082 static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) {
1083         union sockaddr_union sa = {
1084                 .in.sin_family = AF_INET,
1085         };
1086         union {
1087                 struct cmsghdr header; /* For alignment */
1088                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
1089         } control;
1090         struct msghdr mh = {};
1091         struct iovec iov;
1092
1093         assert(m);
1094         assert(fd >= 0);
1095         assert(addr);
1096         assert(port > 0);
1097         assert(p);
1098
1099         iov.iov_base = DNS_PACKET_DATA(p);
1100         iov.iov_len = p->size;
1101
1102         sa.in.sin_addr = *addr;
1103         sa.in.sin_port = htobe16(port),
1104
1105         mh.msg_iov = &iov;
1106         mh.msg_iovlen = 1;
1107         mh.msg_name = &sa.sa;
1108         mh.msg_namelen = sizeof(sa.in);
1109
1110         if (ifindex > 0) {
1111                 struct cmsghdr *cmsg;
1112                 struct in_pktinfo *pi;
1113
1114                 zero(control);
1115
1116                 mh.msg_control = &control;
1117                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
1118
1119                 cmsg = CMSG_FIRSTHDR(&mh);
1120                 cmsg->cmsg_len = mh.msg_controllen;
1121                 cmsg->cmsg_level = IPPROTO_IP;
1122                 cmsg->cmsg_type = IP_PKTINFO;
1123
1124                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
1125                 pi->ipi_ifindex = ifindex;
1126         }
1127
1128         return sendmsg_loop(fd, &mh, 0);
1129 }
1130
1131 static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) {
1132         union sockaddr_union sa = {
1133                 .in6.sin6_family = AF_INET6,
1134         };
1135         union {
1136                 struct cmsghdr header; /* For alignment */
1137                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
1138         } control;
1139         struct msghdr mh = {};
1140         struct iovec iov;
1141
1142         assert(m);
1143         assert(fd >= 0);
1144         assert(addr);
1145         assert(port > 0);
1146         assert(p);
1147
1148         iov.iov_base = DNS_PACKET_DATA(p);
1149         iov.iov_len = p->size;
1150
1151         sa.in6.sin6_addr = *addr;
1152         sa.in6.sin6_port = htobe16(port),
1153         sa.in6.sin6_scope_id = ifindex;
1154
1155         mh.msg_iov = &iov;
1156         mh.msg_iovlen = 1;
1157         mh.msg_name = &sa.sa;
1158         mh.msg_namelen = sizeof(sa.in6);
1159
1160         if (ifindex > 0) {
1161                 struct cmsghdr *cmsg;
1162                 struct in6_pktinfo *pi;
1163
1164                 zero(control);
1165
1166                 mh.msg_control = &control;
1167                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
1168
1169                 cmsg = CMSG_FIRSTHDR(&mh);
1170                 cmsg->cmsg_len = mh.msg_controllen;
1171                 cmsg->cmsg_level = IPPROTO_IPV6;
1172                 cmsg->cmsg_type = IPV6_PKTINFO;
1173
1174                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
1175                 pi->ipi6_ifindex = ifindex;
1176         }
1177
1178         return sendmsg_loop(fd, &mh, 0);
1179 }
1180
1181 int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) {
1182         assert(m);
1183         assert(fd >= 0);
1184         assert(addr);
1185         assert(port > 0);
1186         assert(p);
1187
1188         log_debug("Sending %s packet with id %u on interface %i/%s", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family));
1189
1190         if (family == AF_INET)
1191                 return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p);
1192         else if (family == AF_INET6)
1193                 return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p);
1194
1195         return -EAFNOSUPPORT;
1196 }
1197
1198 DnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr) {
1199         DnsServer *s;
1200
1201         assert(m);
1202         assert(in_addr);
1203
1204         LIST_FOREACH(servers, s, m->dns_servers)
1205                 if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
1206                         return s;
1207
1208         LIST_FOREACH(servers, s, m->fallback_dns_servers)
1209                 if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
1210                         return s;
1211
1212         return NULL;
1213 }
1214
1215 DnsServer *manager_set_dns_server(Manager *m, DnsServer *s) {
1216         assert(m);
1217
1218         if (m->current_dns_server == s)
1219                 return s;
1220
1221         if (s) {
1222                 _cleanup_free_ char *ip = NULL;
1223
1224                 in_addr_to_string(s->family, &s->address, &ip);
1225                 log_info("Switching to system DNS server %s.", strna(ip));
1226         }
1227
1228         m->current_dns_server = s;
1229
1230         if (m->unicast_scope)
1231                 dns_cache_flush(&m->unicast_scope->cache);
1232
1233         return s;
1234 }
1235
1236 DnsServer *manager_get_dns_server(Manager *m) {
1237         Link *l;
1238         assert(m);
1239
1240         /* Try to read updates resolv.conf */
1241         manager_read_resolv_conf(m);
1242
1243         if (!m->current_dns_server)
1244                 manager_set_dns_server(m, m->dns_servers);
1245
1246         if (!m->current_dns_server) {
1247                 bool found = false;
1248                 Iterator i;
1249
1250                 /* No DNS servers configured, let's see if there are
1251                  * any on any links. If not, we use the fallback
1252                  * servers */
1253
1254                 HASHMAP_FOREACH(l, m->links, i)
1255                         if (l->dns_servers) {
1256                                 found = true;
1257                                 break;
1258                         }
1259
1260                 if (!found)
1261                         manager_set_dns_server(m, m->fallback_dns_servers);
1262         }
1263
1264         return m->current_dns_server;
1265 }
1266
1267 void manager_next_dns_server(Manager *m) {
1268         assert(m);
1269
1270         /* If there's currently no DNS server set, then the next
1271          * manager_get_dns_server() will find one */
1272         if (!m->current_dns_server)
1273                 return;
1274
1275         /* Change to the next one */
1276         if (m->current_dns_server->servers_next) {
1277                 manager_set_dns_server(m, m->current_dns_server->servers_next);
1278                 return;
1279         }
1280
1281         /* If there was no next one, then start from the beginning of
1282          * the list */
1283         if (m->current_dns_server->type == DNS_SERVER_FALLBACK)
1284                 manager_set_dns_server(m, m->fallback_dns_servers);
1285         else
1286                 manager_set_dns_server(m, m->dns_servers);
1287 }
1288
1289 uint32_t manager_find_mtu(Manager *m) {
1290         uint32_t mtu = 0;
1291         Link *l;
1292         Iterator i;
1293
1294         /* If we don't know on which link a DNS packet would be
1295          * delivered, let's find the largest MTU that works on all
1296          * interfaces we know of */
1297
1298         HASHMAP_FOREACH(l, m->links, i) {
1299                 if (l->mtu <= 0)
1300                         continue;
1301
1302                 if (mtu <= 0 || l->mtu < mtu)
1303                         mtu = l->mtu;
1304         }
1305
1306         return mtu;
1307 }
1308
1309 static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1310         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
1311         DnsTransaction *t = NULL;
1312         Manager *m = userdata;
1313         DnsScope *scope;
1314         int r;
1315
1316         r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p);
1317         if (r <= 0)
1318                 return r;
1319
1320         scope = manager_find_scope(m, p);
1321         if (!scope) {
1322                 log_warning("Got LLMNR UDP packet on unknown scope. Ignoring.");
1323                 return 0;
1324         }
1325
1326         if (dns_packet_validate_reply(p) > 0) {
1327                 log_debug("Got reply packet for id %u", DNS_PACKET_ID(p));
1328
1329                 dns_scope_check_conflicts(scope, p);
1330
1331                 t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));
1332                 if (t)
1333                         dns_transaction_process_reply(t, p);
1334
1335         } else if (dns_packet_validate_query(p) > 0)  {
1336                 log_debug("Got query packet for id %u", DNS_PACKET_ID(p));
1337
1338                 dns_scope_process_query(scope, NULL, p);
1339         } else
1340                 log_debug("Invalid LLMNR UDP packet.");
1341
1342         return 0;
1343 }
1344
1345 int manager_llmnr_ipv4_udp_fd(Manager *m) {
1346         union sockaddr_union sa = {
1347                 .in.sin_family = AF_INET,
1348                 .in.sin_port = htobe16(5355),
1349         };
1350         static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255;
1351         int r;
1352
1353         assert(m);
1354
1355         if (m->llmnr_ipv4_udp_fd >= 0)
1356                 return m->llmnr_ipv4_udp_fd;
1357
1358         m->llmnr_ipv4_udp_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
1359         if (m->llmnr_ipv4_udp_fd < 0)
1360                 return -errno;
1361
1362         /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */
1363         r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));
1364         if (r < 0) {
1365                 r = -errno;
1366                 goto fail;
1367         }
1368
1369         r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
1370         if (r < 0) {
1371                 r = -errno;
1372                 goto fail;
1373         }
1374
1375         r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one));
1376         if (r < 0) {
1377                 r = -errno;
1378                 goto fail;
1379         }
1380
1381         r = setsockopt(m->llmnr_ipv4_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
1382         if (r < 0) {
1383                 r = -errno;
1384                 goto fail;
1385         }
1386
1387         r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
1388         if (r < 0) {
1389                 r = -errno;
1390                 goto fail;
1391         }
1392
1393         r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one));
1394         if (r < 0) {
1395                 r = -errno;
1396                 goto fail;
1397         }
1398
1399         /* Disable Don't-Fragment bit in the IP header */
1400         r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu));
1401         if (r < 0) {
1402                 r = -errno;
1403                 goto fail;
1404         }
1405
1406         r = bind(m->llmnr_ipv4_udp_fd, &sa.sa, sizeof(sa.in));
1407         if (r < 0) {
1408                 r = -errno;
1409                 goto fail;
1410         }
1411
1412         r = sd_event_add_io(m->event, &m->llmnr_ipv4_udp_event_source, m->llmnr_ipv4_udp_fd, EPOLLIN, on_llmnr_packet, m);
1413         if (r < 0)
1414                 goto fail;
1415
1416         return m->llmnr_ipv4_udp_fd;
1417
1418 fail:
1419         m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd);
1420         return r;
1421 }
1422
1423 int manager_llmnr_ipv6_udp_fd(Manager *m) {
1424         union sockaddr_union sa = {
1425                 .in6.sin6_family = AF_INET6,
1426                 .in6.sin6_port = htobe16(5355),
1427         };
1428         static const int one = 1, ttl = 255;
1429         int r;
1430
1431         assert(m);
1432
1433         if (m->llmnr_ipv6_udp_fd >= 0)
1434                 return m->llmnr_ipv6_udp_fd;
1435
1436         m->llmnr_ipv6_udp_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
1437         if (m->llmnr_ipv6_udp_fd < 0)
1438                 return -errno;
1439
1440         r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));
1441         if (r < 0) {
1442                 r = -errno;
1443                 goto fail;
1444         }
1445
1446         /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */
1447         r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl));
1448         if (r < 0) {
1449                 r = -errno;
1450                 goto fail;
1451         }
1452
1453         r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one));
1454         if (r < 0) {
1455                 r = -errno;
1456                 goto fail;
1457         }
1458
1459         r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
1460         if (r < 0) {
1461                 r = -errno;
1462                 goto fail;
1463         }
1464
1465         r = setsockopt(m->llmnr_ipv6_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
1466         if (r < 0) {
1467                 r = -errno;
1468                 goto fail;
1469         }
1470
1471         r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
1472         if (r < 0) {
1473                 r = -errno;
1474                 goto fail;
1475         }
1476
1477         r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one));
1478         if (r < 0) {
1479                 r = -errno;
1480                 goto fail;
1481         }
1482
1483         r = bind(m->llmnr_ipv6_udp_fd, &sa.sa, sizeof(sa.in6));
1484         if (r < 0) {
1485                 r = -errno;
1486                 goto fail;
1487         }
1488
1489         r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, m->llmnr_ipv6_udp_fd, EPOLLIN, on_llmnr_packet, m);
1490         if (r < 0)  {
1491                 r = -errno;
1492                 goto fail;
1493         }
1494
1495         return m->llmnr_ipv6_udp_fd;
1496
1497 fail:
1498         m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd);
1499         return r;
1500 }
1501
1502 static int on_llmnr_stream_packet(DnsStream *s) {
1503         DnsScope *scope;
1504
1505         assert(s);
1506
1507         scope = manager_find_scope(s->manager, s->read_packet);
1508         if (!scope) {
1509                 log_warning("Got LLMNR TCP packet on unknown scope. Ignroing.");
1510                 return 0;
1511         }
1512
1513         if (dns_packet_validate_query(s->read_packet) > 0) {
1514                 log_debug("Got query packet for id %u", DNS_PACKET_ID(s->read_packet));
1515
1516                 dns_scope_process_query(scope, s, s->read_packet);
1517
1518                 /* If no reply packet was set, we free the stream */
1519                 if (s->write_packet)
1520                         return 0;
1521         } else
1522                 log_debug("Invalid LLMNR TCP packet.");
1523
1524         dns_stream_free(s);
1525         return 0;
1526 }
1527
1528 static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
1529         DnsStream *stream;
1530         Manager *m = userdata;
1531         int cfd, r;
1532
1533         cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
1534         if (cfd < 0) {
1535                 if (errno == EAGAIN || errno == EINTR)
1536                         return 0;
1537
1538                 return -errno;
1539         }
1540
1541         r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd);
1542         if (r < 0) {
1543                 safe_close(cfd);
1544                 return r;
1545         }
1546
1547         stream->on_packet = on_llmnr_stream_packet;
1548         return 0;
1549 }
1550
1551 int manager_llmnr_ipv4_tcp_fd(Manager *m) {
1552         union sockaddr_union sa = {
1553                 .in.sin_family = AF_INET,
1554                 .in.sin_port = htobe16(5355),
1555         };
1556         static const int one = 1, pmtu = IP_PMTUDISC_DONT;
1557         int r;
1558
1559         assert(m);
1560
1561         if (m->llmnr_ipv4_tcp_fd >= 0)
1562                 return m->llmnr_ipv4_tcp_fd;
1563
1564         m->llmnr_ipv4_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
1565         if (m->llmnr_ipv4_tcp_fd < 0)
1566                 return -errno;
1567
1568         /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */
1569         r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_TTL, &one, sizeof(one));
1570         if (r < 0) {
1571                 r = -errno;
1572                 goto fail;
1573         }
1574
1575         r = setsockopt(m->llmnr_ipv4_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
1576         if (r < 0) {
1577                 r = -errno;
1578                 goto fail;
1579         }
1580
1581         r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));
1582         if (r < 0) {
1583                 r = -errno;
1584                 goto fail;
1585         }
1586
1587         r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one));
1588         if (r < 0) {
1589                 r = -errno;
1590                 goto fail;
1591         }
1592
1593         /* Disable Don't-Fragment bit in the IP header */
1594         r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu));
1595         if (r < 0) {
1596                 r = -errno;
1597                 goto fail;
1598         }
1599
1600         r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in));
1601         if (r < 0) {
1602                 r = -errno;
1603                 goto fail;
1604         }
1605
1606         r = listen(m->llmnr_ipv4_tcp_fd, SOMAXCONN);
1607         if (r < 0) {
1608                 r = -errno;
1609                 goto fail;
1610         }
1611
1612         r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, m->llmnr_ipv4_tcp_fd, EPOLLIN, on_llmnr_stream, m);
1613         if (r < 0)
1614                 goto fail;
1615
1616         return m->llmnr_ipv4_tcp_fd;
1617
1618 fail:
1619         m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd);
1620         return r;
1621 }
1622
1623 int manager_llmnr_ipv6_tcp_fd(Manager *m) {
1624         union sockaddr_union sa = {
1625                 .in6.sin6_family = AF_INET6,
1626                 .in6.sin6_port = htobe16(5355),
1627         };
1628         static const int one = 1;
1629         int r;
1630
1631         assert(m);
1632
1633         if (m->llmnr_ipv6_tcp_fd >= 0)
1634                 return m->llmnr_ipv6_tcp_fd;
1635
1636         m->llmnr_ipv6_tcp_fd = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
1637         if (m->llmnr_ipv6_tcp_fd < 0)
1638                 return -errno;
1639
1640         /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */
1641         r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one));
1642         if (r < 0) {
1643                 r = -errno;
1644                 goto fail;
1645         }
1646
1647         r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));
1648         if (r < 0) {
1649                 r = -errno;
1650                 goto fail;
1651         }
1652
1653         r = setsockopt(m->llmnr_ipv6_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
1654         if (r < 0) {
1655                 r = -errno;
1656                 goto fail;
1657         }
1658
1659         r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
1660         if (r < 0) {
1661                 r = -errno;
1662                 goto fail;
1663         }
1664
1665         r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one));
1666         if (r < 0) {
1667                 r = -errno;
1668                 goto fail;
1669         }
1670
1671         r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6));
1672         if (r < 0) {
1673                 r = -errno;
1674                 goto fail;
1675         }
1676
1677         r = listen(m->llmnr_ipv6_tcp_fd, SOMAXCONN);
1678         if (r < 0) {
1679                 r = -errno;
1680                 goto fail;
1681         }
1682
1683         r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, m->llmnr_ipv6_tcp_fd, EPOLLIN, on_llmnr_stream, m);
1684         if (r < 0)  {
1685                 r = -errno;
1686                 goto fail;
1687         }
1688
1689         return m->llmnr_ipv6_tcp_fd;
1690
1691 fail:
1692         m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd);
1693         return r;
1694 }
1695
1696 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
1697         LinkAddress *a;
1698
1699         assert(m);
1700
1701         a = manager_find_link_address(m, family, in_addr);
1702         if (a)
1703                 return a->link->ifindex;
1704
1705         return 0;
1706 }
1707
1708 void manager_refresh_rrs(Manager *m) {
1709         Iterator i;
1710         Link *l;
1711
1712         assert(m);
1713
1714         m->host_ipv4_key = dns_resource_key_unref(m->host_ipv4_key);
1715         m->host_ipv6_key = dns_resource_key_unref(m->host_ipv6_key);
1716
1717         HASHMAP_FOREACH(l, m->links, i) {
1718                 link_add_rrs(l, true);
1719                 link_add_rrs(l, false);
1720         }
1721 }
1722
1723 int manager_next_hostname(Manager *m) {
1724         const char *p;
1725         uint64_t u, a;
1726         char *h;
1727
1728         assert(m);
1729
1730         p = strchr(m->hostname, 0);
1731         assert(p);
1732
1733         while (p > m->hostname) {
1734                 if (!strchr("0123456789", p[-1]))
1735                         break;
1736
1737                 p--;
1738         }
1739
1740         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
1741                 u = 1;
1742
1743         /* Add a random number to the old value. This way we can avoid
1744          * that two hosts pick the same hostname, win on IPv4 and lose
1745          * on IPv6 (or vice versa), and pick the same hostname
1746          * replacement hostname, ad infinitum. We still want the
1747          * numbers to go up monotonically, hence we just add a random
1748          * value 1..10 */
1749
1750         random_bytes(&a, sizeof(a));
1751         u += 1 + a % 10;
1752
1753         if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->hostname), m->hostname, u) < 0)
1754                 return -ENOMEM;
1755
1756         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->hostname, h);
1757
1758         free(m->hostname);
1759         m->hostname = h;
1760
1761         manager_refresh_rrs(m);
1762
1763         return 0;
1764 }
1765
1766 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1767         Iterator i;
1768         Link *l;
1769
1770         assert(m);
1771
1772         HASHMAP_FOREACH(l, m->links, i) {
1773                 LinkAddress *a;
1774
1775                 a = link_find_address(l, family, in_addr);
1776                 if (a)
1777                         return a;
1778         }
1779
1780         return NULL;
1781 }
1782
1783 bool manager_our_packet(Manager *m, DnsPacket *p) {
1784         assert(m);
1785         assert(p);
1786
1787         return !!manager_find_link_address(m, p->family, &p->sender);
1788 }
1789
1790 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1791         Link *l;
1792
1793         assert(m);
1794         assert(p);
1795
1796         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1797         if (!l)
1798                 return NULL;
1799
1800         if (p->protocol == DNS_PROTOCOL_LLMNR) {
1801                 if (p->family == AF_INET)
1802                         return l->llmnr_ipv4_scope;
1803                 else if (p->family == AF_INET6)
1804                         return l->llmnr_ipv6_scope;
1805         }
1806
1807         return NULL;
1808 }
1809
1810 void manager_verify_all(Manager *m) {
1811         DnsScope *s;
1812
1813         assert(m);
1814
1815         LIST_FOREACH(scopes, s, m->dns_scopes)
1816                 dns_zone_verify_all(&s->zone);
1817 }
1818
1819 void manager_flush_dns_servers(Manager *m, DnsServerType t) {
1820         assert(m);
1821
1822         if (t == DNS_SERVER_SYSTEM)
1823                 while (m->dns_servers)
1824                         dns_server_free(m->dns_servers);
1825
1826         if (t == DNS_SERVER_FALLBACK)
1827                 while (m->fallback_dns_servers)
1828                         dns_server_free(m->fallback_dns_servers);
1829 }
1830
1831 static const char* const support_table[_SUPPORT_MAX] = {
1832         [SUPPORT_NO] = "no",
1833         [SUPPORT_YES] = "yes",
1834         [SUPPORT_RESOLVE] = "resolve",
1835 };
1836 DEFINE_STRING_TABLE_LOOKUP(support, Support);