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