src/resolve/resolved-manager.c

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