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 **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(llmnr_hostname);
 332         assert(mdns_hostname);
 333
 334         /* Extract and normalize the first label of the locally
 335          * configured hostname, and check it's not "localhost". */
 336
 337         h = gethostname_malloc();
 338         if (!h)
 339                 return log_oom();
 340
 341         p = h;
 342         r = dns_label_unescape(&p, label, sizeof(label));
 343         if (r < 0)
 344                 return log_error_errno(r, "Failed to unescape host name: %m");
 345         if (r == 0) {
 346                 log_error("Couldn't find a single label in hosntame.");
 347                 return -EINVAL;
 348         }
 349
 350         k = dns_label_undo_idna(label, r, label, sizeof(label));
 351         if (k < 0)
 352                 return log_error_errno(k, "Failed to undo IDNA: %m");
 353         if (k > 0)
 354                 r = k;
 355
 356         if (!utf8_is_valid(label)) {
 357                 log_error("System hostname is not UTF-8 clean.");
 358                 return -EINVAL;
 359         }
 360
 361         r = dns_label_escape_new(label, r, &n);
 362         if (r < 0)
 363                 return log_error_errno(r, "Failed to escape host name: %m");
 364
 365         if (is_localhost(n)) {
 366                 log_debug("System hostname is 'localhost', ignoring.");
 367                 return -EINVAL;
 368         }
 369
 370         r = dns_name_concat(n, "local", mdns_hostname);
 371         if (r < 0)
 372                 return log_error_errno(r, "Failed to determine mDNS hostname: %m");
 373
 374         *llmnr_hostname = n;
 375         n = NULL;
 376
 377         return 0;
 378 }
 379
 380 static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
 381         _cleanup_free_ char *llmnr_hostname = NULL, *mdns_hostname = NULL;
 382         Manager *m = userdata;
 383         int r;
 384
 385         assert(m);
 386
 387         r = determine_hostname(&llmnr_hostname, &mdns_hostname);
 388         if (r < 0)
 389                 return 0; /* ignore invalid hostnames */
 390
 391         if (streq(llmnr_hostname, m->llmnr_hostname) && streq(mdns_hostname, m->mdns_hostname))
 392                 return 0;
 393
 394         log_info("System hostname changed to '%s'.", llmnr_hostname);
 395
 396         free(m->llmnr_hostname);
 397         free(m->mdns_hostname);
 398
 399         m->llmnr_hostname = llmnr_hostname;
 400         m->mdns_hostname = mdns_hostname;
 401
 402         llmnr_hostname = mdns_hostname = NULL;
 403
 404         manager_refresh_rrs(m);
 405
 406         return 0;
 407 }
 408
 409 static int manager_watch_hostname(Manager *m) {
 410         int r;
 411
 412         assert(m);
 413
 414         m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY);
 415         if (m->hostname_fd < 0) {
 416                 log_warning_errno(errno, "Failed to watch hostname: %m");
 417                 return 0;
 418         }
 419
 420         r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
 421         if (r < 0) {
 422                 if (r == -EPERM)
 423                         /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
 424                         m->hostname_fd = safe_close(m->hostname_fd);
 425                 else
 426                         return log_error_errno(r, "Failed to add hostname event source: %m");
 427         }
 428
 429         (void) sd_event_source_set_description(m->hostname_event_source, "hostname");
 430
 431         r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname);
 432         if (r < 0) {
 433                 log_info("Defaulting to hostname 'linux'.");
 434                 m->llmnr_hostname = strdup("linux");
 435                 if (!m->llmnr_hostname)
 436                         return log_oom();
 437
 438                 m->mdns_hostname = strdup("linux.local");
 439                 if (!m->mdns_hostname)
 440                         return log_oom();
 441         } else
 442                 log_info("Using system hostname '%s'.", m->llmnr_hostname);
 443
 444         return 0;
 445 }
 446
 447 static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 448         _cleanup_free_ char *buffer = NULL;
 449         _cleanup_fclose_ FILE *f = NULL;
 450         Manager *m = userdata;
 451         size_t size = 0;
 452         DnsScope *scope;
 453
 454         assert(s);
 455         assert(si);
 456         assert(m);
 457
 458         f = open_memstream(&buffer, &size);
 459         if (!f)
 460                 return log_oom();
 461
 462         LIST_FOREACH(scopes, scope, m->dns_scopes)
 463                 dns_scope_dump(scope, f);
 464
 465         if (fflush_and_check(f) < 0)
 466                 return log_oom();
 467
 468         log_dump(LOG_INFO, buffer);
 469         return 0;
 470 }
 471
 472 static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 473         Manager *m = userdata;
 474
 475         assert(s);
 476         assert(si);
 477         assert(m);
 478
 479         manager_flush_caches(m);
 480
 481         return 0;
 482 }
 483
 484 int manager_new(Manager **ret) {
 485         _cleanup_(manager_freep) Manager *m = NULL;
 486         int r;
 487
 488         assert(ret);
 489
 490         m = new0(Manager, 1);
 491         if (!m)
 492                 return -ENOMEM;
 493
 494         m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
 495         m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
 496         m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1;
 497         m->dns_stub_udp_fd = m->dns_stub_tcp_fd = -1;
 498         m->hostname_fd = -1;
 499
 500         m->llmnr_support = RESOLVE_SUPPORT_YES;
 501         m->mdns_support = RESOLVE_SUPPORT_NO;
 502         m->dnssec_mode = DEFAULT_DNSSEC_MODE;
 503         m->enable_cache = true;
 504         m->read_resolv_conf = true;
 505         m->need_builtin_fallbacks = true;
 506         m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY;
 507
 508         r = dns_trust_anchor_load(&m->trust_anchor);
 509         if (r < 0)
 510                 return r;
 511
 512         r = manager_parse_config_file(m);
 513         if (r < 0)
 514                 return r;
 515
 516         r = sd_event_default(&m->event);
 517         if (r < 0)
 518                 return r;
 519
 520         sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
 521         sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
 522
 523         sd_event_set_watchdog(m->event, true);
 524
 525         r = manager_watch_hostname(m);
 526         if (r < 0)
 527                 return r;
 528
 529         r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 530         if (r < 0)
 531                 return r;
 532
 533         r = manager_network_monitor_listen(m);
 534         if (r < 0)
 535                 return r;
 536
 537         r = manager_rtnl_listen(m);
 538         if (r < 0)
 539                 return r;
 540
 541         r = manager_connect_bus(m);
 542         if (r < 0)
 543                 return r;
 544
 545         (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m);
 546         (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m);
 547
 548         manager_cleanup_saved_user(m);
 549
 550         *ret = m;
 551         m = NULL;
 552
 553         return 0;
 554 }
 555
 556 int manager_start(Manager *m) {
 557         int r;
 558
 559         assert(m);
 560
 561         r = manager_dns_stub_start(m);
 562         if (r < 0)
 563                 return r;
 564
 565         r = manager_llmnr_start(m);
 566         if (r < 0)
 567                 return r;
 568
 569         r = manager_mdns_start(m);
 570         if (r < 0)
 571                 return r;
 572
 573         return 0;
 574 }
 575
 576 Manager *manager_free(Manager *m) {
 577         Link *l;
 578
 579         if (!m)
 580                 return NULL;
 581
 582         dns_server_unlink_all(m->dns_servers);
 583         dns_server_unlink_all(m->fallback_dns_servers);
 584         dns_search_domain_unlink_all(m->search_domains);
 585
 586         while ((l = hashmap_first(m->links)))
 587                link_free(l);
 588
 589         while (m->dns_queries)
 590                 dns_query_free(m->dns_queries);
 591
 592         dns_scope_free(m->unicast_scope);
 593
 594         /* At this point only orphaned streams should remain. All others should have been freed already by their
 595          * owners */
 596         while (m->dns_streams)
 597                 dns_stream_unref(m->dns_streams);
 598
 599         hashmap_free(m->links);
 600         hashmap_free(m->dns_transactions);
 601
 602         sd_event_source_unref(m->network_event_source);
 603         sd_network_monitor_unref(m->network_monitor);
 604
 605         sd_netlink_unref(m->rtnl);
 606         sd_event_source_unref(m->rtnl_event_source);
 607
 608         manager_llmnr_stop(m);
 609         manager_mdns_stop(m);
 610         manager_dns_stub_stop(m);
 611
 612         sd_bus_slot_unref(m->prepare_for_sleep_slot);
 613         sd_event_source_unref(m->bus_retry_event_source);
 614         sd_bus_unref(m->bus);
 615
 616         sd_event_source_unref(m->sigusr1_event_source);
 617         sd_event_source_unref(m->sigusr2_event_source);
 618
 619         sd_event_unref(m->event);
 620
 621         dns_resource_key_unref(m->llmnr_host_ipv4_key);
 622         dns_resource_key_unref(m->llmnr_host_ipv6_key);
 623
 624         sd_event_source_unref(m->hostname_event_source);
 625         safe_close(m->hostname_fd);
 626         free(m->llmnr_hostname);
 627         free(m->mdns_hostname);
 628
 629         dns_trust_anchor_flush(&m->trust_anchor);
 630         manager_etc_hosts_flush(m);
 631
 632         free(m);
 633
 634         return NULL;
 635 }
 636
 637 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 638         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 639         union {
 640                 struct cmsghdr header; /* For alignment */
 641                 uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 642                                + CMSG_SPACE(int) /* ttl/hoplimit */
 643                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
 644         } control;
 645         union sockaddr_union sa;
 646         struct msghdr mh = {};
 647         struct cmsghdr *cmsg;
 648         struct iovec iov;
 649         ssize_t ms, l;
 650         int r;
 651
 652         assert(m);
 653         assert(fd >= 0);
 654         assert(ret);
 655
 656         ms = next_datagram_size_fd(fd);
 657         if (ms < 0)
 658                 return ms;
 659
 660         r = dns_packet_new(&p, protocol, ms);
 661         if (r < 0)
 662                 return r;
 663
 664         iov.iov_base = DNS_PACKET_DATA(p);
 665         iov.iov_len = p->allocated;
 666
 667         mh.msg_name = &sa.sa;
 668         mh.msg_namelen = sizeof(sa);
 669         mh.msg_iov = &iov;
 670         mh.msg_iovlen = 1;
 671         mh.msg_control = &control;
 672         mh.msg_controllen = sizeof(control);
 673
 674         l = recvmsg(fd, &mh, 0);
 675         if (l == 0)
 676                 return 0;
 677         if (l < 0) {
 678                 if (errno == EAGAIN || errno == EINTR)
 679                         return 0;
 680
 681                 return -errno;
 682         }
 683
 684         assert(!(mh.msg_flags & MSG_CTRUNC));
 685         assert(!(mh.msg_flags & MSG_TRUNC));
 686
 687         p->size = (size_t) l;
 688
 689         p->family = sa.sa.sa_family;
 690         p->ipproto = IPPROTO_UDP;
 691         if (p->family == AF_INET) {
 692                 p->sender.in = sa.in.sin_addr;
 693                 p->sender_port = be16toh(sa.in.sin_port);
 694         } else if (p->family == AF_INET6) {
 695                 p->sender.in6 = sa.in6.sin6_addr;
 696                 p->sender_port = be16toh(sa.in6.sin6_port);
 697                 p->ifindex = sa.in6.sin6_scope_id;
 698         } else
 699                 return -EAFNOSUPPORT;
 700
 701         CMSG_FOREACH(cmsg, &mh) {
 702
 703                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 704                         assert(p->family == AF_INET6);
 705
 706                         switch (cmsg->cmsg_type) {
 707
 708                         case IPV6_PKTINFO: {
 709                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 710
 711                                 if (p->ifindex <= 0)
 712                                         p->ifindex = i->ipi6_ifindex;
 713
 714                                 p->destination.in6 = i->ipi6_addr;
 715                                 break;
 716                         }
 717
 718                         case IPV6_HOPLIMIT:
 719                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 720                                 break;
 721
 722                         }
 723                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 724                         assert(p->family == AF_INET);
 725
 726                         switch (cmsg->cmsg_type) {
 727
 728                         case IP_PKTINFO: {
 729                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 730
 731                                 if (p->ifindex <= 0)
 732                                         p->ifindex = i->ipi_ifindex;
 733
 734                                 p->destination.in = i->ipi_addr;
 735                                 break;
 736                         }
 737
 738                         case IP_TTL:
 739                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 740                                 break;
 741                         }
 742                 }
 743         }
 744
 745         /* The Linux kernel sets the interface index to the loopback
 746          * device if the packet came from the local host since it
 747          * avoids the routing table in such a case. Let's unset the
 748          * interface index in such a case. */
 749         if (p->ifindex == LOOPBACK_IFINDEX)
 750                 p->ifindex = 0;
 751
 752         if (protocol != DNS_PROTOCOL_DNS) {
 753                 /* If we don't know the interface index still, we look for the
 754                  * first local interface with a matching address. Yuck! */
 755                 if (p->ifindex <= 0)
 756                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 757         }
 758
 759         *ret = p;
 760         p = NULL;
 761
 762         return 1;
 763 }
 764
 765 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
 766         int r;
 767
 768         assert(fd >= 0);
 769         assert(mh);
 770
 771         for (;;) {
 772                 if (sendmsg(fd, mh, flags) >= 0)
 773                         return 0;
 774
 775                 if (errno == EINTR)
 776                         continue;
 777
 778                 if (errno != EAGAIN)
 779                         return -errno;
 780
 781                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 782                 if (r < 0)
 783                         return r;
 784                 if (r == 0)
 785                         return -ETIMEDOUT;
 786         }
 787 }
 788
 789 static int write_loop(int fd, void *message, size_t length) {
 790         int r;
 791
 792         assert(fd >= 0);
 793         assert(message);
 794
 795         for (;;) {
 796                 if (write(fd, message, length) >= 0)
 797                         return 0;
 798
 799                 if (errno == EINTR)
 800                         continue;
 801
 802                 if (errno != EAGAIN)
 803                         return -errno;
 804
 805                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 806                 if (r < 0)
 807                         return r;
 808                 if (r == 0)
 809                         return -ETIMEDOUT;
 810         }
 811 }
 812
 813 int manager_write(Manager *m, int fd, DnsPacket *p) {
 814         int r;
 815
 816         log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
 817
 818         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
 819         if (r < 0)
 820                 return r;
 821
 822         return 0;
 823 }
 824
 825 static int manager_ipv4_send(
 826                 Manager *m,
 827                 int fd,
 828                 int ifindex,
 829                 const struct in_addr *destination,
 830                 uint16_t port,
 831                 const struct in_addr *source,
 832                 DnsPacket *p) {
 833         union sockaddr_union sa = {
 834                 .in.sin_family = AF_INET,
 835         };
 836         union {
 837                 struct cmsghdr header; /* For alignment */
 838                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
 839         } control;
 840         struct msghdr mh = {};
 841         struct iovec iov;
 842
 843         assert(m);
 844         assert(fd >= 0);
 845         assert(destination);
 846         assert(port > 0);
 847         assert(p);
 848
 849         iov.iov_base = DNS_PACKET_DATA(p);
 850         iov.iov_len = p->size;
 851
 852         sa.in.sin_addr = *destination;
 853         sa.in.sin_port = htobe16(port),
 854
 855         mh.msg_iov = &iov;
 856         mh.msg_iovlen = 1;
 857         mh.msg_name = &sa.sa;
 858         mh.msg_namelen = sizeof(sa.in);
 859
 860         if (ifindex > 0) {
 861                 struct cmsghdr *cmsg;
 862                 struct in_pktinfo *pi;
 863
 864                 zero(control);
 865
 866                 mh.msg_control = &control;
 867                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
 868
 869                 cmsg = CMSG_FIRSTHDR(&mh);
 870                 cmsg->cmsg_len = mh.msg_controllen;
 871                 cmsg->cmsg_level = IPPROTO_IP;
 872                 cmsg->cmsg_type = IP_PKTINFO;
 873
 874                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
 875                 pi->ipi_ifindex = ifindex;
 876
 877                 if (source)
 878                         pi->ipi_spec_dst = *source;
 879         }
 880
 881         return sendmsg_loop(fd, &mh, 0);
 882 }
 883
 884 static int manager_ipv6_send(
 885                 Manager *m,
 886                 int fd,
 887                 int ifindex,
 888                 const struct in6_addr *destination,
 889                 uint16_t port,
 890                 const struct in6_addr *source,
 891                 DnsPacket *p) {
 892
 893         union sockaddr_union sa = {
 894                 .in6.sin6_family = AF_INET6,
 895         };
 896         union {
 897                 struct cmsghdr header; /* For alignment */
 898                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 899         } control;
 900         struct msghdr mh = {};
 901         struct iovec iov;
 902
 903         assert(m);
 904         assert(fd >= 0);
 905         assert(destination);
 906         assert(port > 0);
 907         assert(p);
 908
 909         iov.iov_base = DNS_PACKET_DATA(p);
 910         iov.iov_len = p->size;
 911
 912         sa.in6.sin6_addr = *destination;
 913         sa.in6.sin6_port = htobe16(port),
 914         sa.in6.sin6_scope_id = ifindex;
 915
 916         mh.msg_iov = &iov;
 917         mh.msg_iovlen = 1;
 918         mh.msg_name = &sa.sa;
 919         mh.msg_namelen = sizeof(sa.in6);
 920
 921         if (ifindex > 0) {
 922                 struct cmsghdr *cmsg;
 923                 struct in6_pktinfo *pi;
 924
 925                 zero(control);
 926
 927                 mh.msg_control = &control;
 928                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
 929
 930                 cmsg = CMSG_FIRSTHDR(&mh);
 931                 cmsg->cmsg_len = mh.msg_controllen;
 932                 cmsg->cmsg_level = IPPROTO_IPV6;
 933                 cmsg->cmsg_type = IPV6_PKTINFO;
 934
 935                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 936                 pi->ipi6_ifindex = ifindex;
 937
 938                 if (source)
 939                         pi->ipi6_addr = *source;
 940         }
 941
 942         return sendmsg_loop(fd, &mh, 0);
 943 }
 944
 945 int manager_send(
 946                 Manager *m,
 947                 int fd,
 948                 int ifindex,
 949                 int family,
 950                 const union in_addr_union *destination,
 951                 uint16_t port,
 952                 const union in_addr_union *source,
 953                 DnsPacket *p) {
 954
 955         assert(m);
 956         assert(fd >= 0);
 957         assert(destination);
 958         assert(port > 0);
 959         assert(p);
 960
 961         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));
 962
 963         if (family == AF_INET)
 964                 return manager_ipv4_send(m, fd, ifindex, &destination->in, port, &source->in, p);
 965         if (family == AF_INET6)
 966                 return manager_ipv6_send(m, fd, ifindex, &destination->in6, port, &source->in6, p);
 967
 968         return -EAFNOSUPPORT;
 969 }
 970
 971 uint32_t manager_find_mtu(Manager *m) {
 972         uint32_t mtu = 0;
 973         Link *l;
 974         Iterator i;
 975
 976         /* If we don't know on which link a DNS packet would be
 977          * delivered, let's find the largest MTU that works on all
 978          * interfaces we know of */
 979
 980         HASHMAP_FOREACH(l, m->links, i) {
 981                 if (l->mtu <= 0)
 982                         continue;
 983
 984                 if (mtu <= 0 || l->mtu < mtu)
 985                         mtu = l->mtu;
 986         }
 987
 988         return mtu;
 989 }
 990
 991 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
 992         LinkAddress *a;
 993
 994         assert(m);
 995
 996         a = manager_find_link_address(m, family, in_addr);
 997         if (a)
 998                 return a->link->ifindex;
 999
1000         return 0;
1001 }
1002
1003 void manager_refresh_rrs(Manager *m) {
1004         Iterator i;
1005         Link *l;
1006
1007         assert(m);
1008
1009         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
1010         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
1011
1012         HASHMAP_FOREACH(l, m->links, i) {
1013                 link_add_rrs(l, true);
1014                 link_add_rrs(l, false);
1015         }
1016 }
1017
1018 int manager_next_hostname(Manager *m) {
1019         const char *p;
1020         uint64_t u, a;
1021         char *h, *k;
1022         int r;
1023
1024         assert(m);
1025
1026         p = strchr(m->llmnr_hostname, 0);
1027         assert(p);
1028
1029         while (p > m->llmnr_hostname) {
1030                 if (!strchr("0123456789", p[-1]))
1031                         break;
1032
1033                 p--;
1034         }
1035
1036         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
1037                 u = 1;
1038
1039         /* Add a random number to the old value. This way we can avoid
1040          * that two hosts pick the same hostname, win on IPv4 and lose
1041          * on IPv6 (or vice versa), and pick the same hostname
1042          * replacement hostname, ad infinitum. We still want the
1043          * numbers to go up monotonically, hence we just add a random
1044          * value 1..10 */
1045
1046         random_bytes(&a, sizeof(a));
1047         u += 1 + a % 10;
1048
1049         if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0)
1050                 return -ENOMEM;
1051
1052         r = dns_name_concat(h, "local", &k);
1053         if (r < 0) {
1054                 free(h);
1055                 return r;
1056         }
1057
1058         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1059
1060         free(m->llmnr_hostname);
1061         m->llmnr_hostname = h;
1062
1063         free(m->mdns_hostname);
1064         m->mdns_hostname = k;
1065
1066         manager_refresh_rrs(m);
1067
1068         return 0;
1069 }
1070
1071 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1072         Iterator i;
1073         Link *l;
1074
1075         assert(m);
1076
1077         HASHMAP_FOREACH(l, m->links, i) {
1078                 LinkAddress *a;
1079
1080                 a = link_find_address(l, family, in_addr);
1081                 if (a)
1082                         return a;
1083         }
1084
1085         return NULL;
1086 }
1087
1088 bool manager_our_packet(Manager *m, DnsPacket *p) {
1089         assert(m);
1090         assert(p);
1091
1092         return !!manager_find_link_address(m, p->family, &p->sender);
1093 }
1094
1095 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1096         Link *l;
1097
1098         assert(m);
1099         assert(p);
1100
1101         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1102         if (!l)
1103                 return NULL;
1104
1105         switch (p->protocol) {
1106         case DNS_PROTOCOL_LLMNR:
1107                 if (p->family == AF_INET)
1108                         return l->llmnr_ipv4_scope;
1109                 else if (p->family == AF_INET6)
1110                         return l->llmnr_ipv6_scope;
1111
1112                 break;
1113
1114         case DNS_PROTOCOL_MDNS:
1115                 if (p->family == AF_INET)
1116                         return l->mdns_ipv4_scope;
1117                 else if (p->family == AF_INET6)
1118                         return l->mdns_ipv6_scope;
1119
1120                 break;
1121
1122         default:
1123                 break;
1124         }
1125
1126         return NULL;
1127 }
1128
1129 void manager_verify_all(Manager *m) {
1130         DnsScope *s;
1131
1132         assert(m);
1133
1134         LIST_FOREACH(scopes, s, m->dns_scopes)
1135                 dns_zone_verify_all(&s->zone);
1136 }
1137
1138 int manager_is_own_hostname(Manager *m, const char *name) {
1139         int r;
1140
1141         assert(m);
1142         assert(name);
1143
1144         if (m->llmnr_hostname) {
1145                 r = dns_name_equal(name, m->llmnr_hostname);
1146                 if (r != 0)
1147                         return r;
1148         }
1149
1150         if (m->mdns_hostname)
1151                 return dns_name_equal(name, m->mdns_hostname);
1152
1153         return 0;
1154 }
1155
1156 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1157         DnsServer *s;
1158         Iterator i;
1159         Link *l;
1160         int r;
1161
1162         assert(m);
1163         assert(dns);
1164
1165         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1166         if (r < 0)
1167                 return r;
1168
1169         /* First add the system-wide servers and domains */
1170         LIST_FOREACH(servers, s, m->dns_servers) {
1171                 r = ordered_set_put(*dns, s);
1172                 if (r == -EEXIST)
1173                         continue;
1174                 if (r < 0)
1175                         return r;
1176         }
1177
1178         /* Then, add the per-link servers */
1179         HASHMAP_FOREACH(l, m->links, i) {
1180                 LIST_FOREACH(servers, s, l->dns_servers) {
1181                         r = ordered_set_put(*dns, s);
1182                         if (r == -EEXIST)
1183                                 continue;
1184                         if (r < 0)
1185                                 return r;
1186                 }
1187         }
1188
1189         /* If we found nothing, add the fallback servers */
1190         if (ordered_set_isempty(*dns)) {
1191                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1192                         r = ordered_set_put(*dns, s);
1193                         if (r == -EEXIST)
1194                                 continue;
1195                         if (r < 0)
1196                                 return r;
1197                 }
1198         }
1199
1200         return 0;
1201 }
1202
1203 /* filter_route is a tri-state:
1204  *   < 0: no filtering
1205  *   = 0 or false: return only domains which should be used for searching
1206  *   > 0 or true: return only domains which are for routing only
1207  */
1208 int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) {
1209         DnsSearchDomain *d;
1210         Iterator i;
1211         Link *l;
1212         int r;
1213
1214         assert(m);
1215         assert(domains);
1216
1217         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1218         if (r < 0)
1219                 return r;
1220
1221         LIST_FOREACH(domains, d, m->search_domains) {
1222
1223                 if (filter_route >= 0 &&
1224                     d->route_only != !!filter_route)
1225                         continue;
1226
1227                 r = ordered_set_put(*domains, d->name);
1228                 if (r == -EEXIST)
1229                         continue;
1230                 if (r < 0)
1231                         return r;
1232         }
1233
1234         HASHMAP_FOREACH(l, m->links, i) {
1235
1236                 LIST_FOREACH(domains, d, l->search_domains) {
1237
1238                         if (filter_route >= 0 &&
1239                             d->route_only != !!filter_route)
1240                                 continue;
1241
1242                         r = ordered_set_put(*domains, d->name);
1243                         if (r == -EEXIST)
1244                                 continue;
1245                         if (r < 0)
1246                                 return r;
1247                 }
1248         }
1249
1250         return 0;
1251 }
1252
1253 DnssecMode manager_get_dnssec_mode(Manager *m) {
1254         assert(m);
1255
1256         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1257                 return m->dnssec_mode;
1258
1259         return DNSSEC_NO;
1260 }
1261
1262 bool manager_dnssec_supported(Manager *m) {
1263         DnsServer *server;
1264         Iterator i;
1265         Link *l;
1266
1267         assert(m);
1268
1269         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1270                 return false;
1271
1272         server = manager_get_dns_server(m);
1273         if (server && !dns_server_dnssec_supported(server))
1274                 return false;
1275
1276         HASHMAP_FOREACH(l, m->links, i)
1277                 if (!link_dnssec_supported(l))
1278                         return false;
1279
1280         return true;
1281 }
1282
1283 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1284
1285         assert(verdict >= 0);
1286         assert(verdict < _DNSSEC_VERDICT_MAX);
1287
1288         if (log_get_max_level() >= LOG_DEBUG) {
1289                 char s[DNS_RESOURCE_KEY_STRING_MAX];
1290
1291                 log_debug("Found verdict for lookup %s: %s",
1292                           dns_resource_key_to_string(key, s, sizeof s),
1293                           dnssec_verdict_to_string(verdict));
1294         }
1295
1296         m->n_dnssec_verdict[verdict]++;
1297 }
1298
1299 bool manager_routable(Manager *m, int family) {
1300         Iterator i;
1301         Link *l;
1302
1303         assert(m);
1304
1305         /* Returns true if the host has at least one interface with a routable address of the specified type */
1306
1307         HASHMAP_FOREACH(l, m->links, i)
1308                 if (link_relevant(l, family, false))
1309                         return true;
1310
1311         return false;
1312 }
1313
1314 void manager_flush_caches(Manager *m) {
1315         DnsScope *scope;
1316
1317         assert(m);
1318
1319         LIST_FOREACH(scopes, scope, m->dns_scopes)
1320                 dns_cache_flush(&scope->cache);
1321
1322         log_info("Flushed all caches.");
1323 }
1324
1325 void manager_cleanup_saved_user(Manager *m) {
1326         _cleanup_closedir_ DIR *d = NULL;
1327         struct dirent *de;
1328         int r;
1329
1330         assert(m);
1331
1332         /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface
1333          * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can
1334          * be restarted without losing this data. */
1335
1336         d = opendir("/run/systemd/resolve/netif/");
1337         if (!d) {
1338                 if (errno == ENOENT)
1339                         return;
1340
1341                 log_warning_errno(errno, "Failed to open interface directory: %m");
1342                 return;
1343         }
1344
1345         FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) {
1346                 _cleanup_free_ char *p = NULL;
1347                 int ifindex;
1348                 Link *l;
1349
1350                 if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG))
1351                         continue;
1352
1353                 if (STR_IN_SET(de->d_name, ".", ".."))
1354                         continue;
1355
1356                 r = parse_ifindex(de->d_name, &ifindex);
1357                 if (r < 0) /* Probably some temporary file from a previous run. Delete it */
1358                         goto rm;
1359
1360                 l = hashmap_get(m->links, INT_TO_PTR(ifindex));
1361                 if (!l) /* link vanished */
1362                         goto rm;
1363
1364                 if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */
1365                         goto rm;
1366
1367                 continue;
1368
1369         rm:
1370                 p = strappend("/run/systemd/resolve/netif/", de->d_name);
1371                 if (!p) {
1372                         log_oom();
1373                         return;
1374                 }
1375
1376                 (void) unlink(p);
1377         }
1378 }