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         dns_resource_key_unref(m->mdns_host_ipv4_key);
 625         dns_resource_key_unref(m->mdns_host_ipv6_key);
 626
 627         sd_event_source_unref(m->hostname_event_source);
 628         safe_close(m->hostname_fd);
 629         free(m->llmnr_hostname);
 630         free(m->mdns_hostname);
 631
 632         dns_trust_anchor_flush(&m->trust_anchor);
 633         manager_etc_hosts_flush(m);
 634
 635         return mfree(m);
 636 }
 637
 638 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 639         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 640         union {
 641                 struct cmsghdr header; /* For alignment */
 642                 uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 643                                + CMSG_SPACE(int) /* ttl/hoplimit */
 644                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
 645         } control;
 646         union sockaddr_union sa;
 647         struct msghdr mh = {};
 648         struct cmsghdr *cmsg;
 649         struct iovec iov;
 650         ssize_t ms, l;
 651         int r;
 652
 653         assert(m);
 654         assert(fd >= 0);
 655         assert(ret);
 656
 657         ms = next_datagram_size_fd(fd);
 658         if (ms < 0)
 659                 return ms;
 660
 661         r = dns_packet_new(&p, protocol, ms);
 662         if (r < 0)
 663                 return r;
 664
 665         iov.iov_base = DNS_PACKET_DATA(p);
 666         iov.iov_len = p->allocated;
 667
 668         mh.msg_name = &sa.sa;
 669         mh.msg_namelen = sizeof(sa);
 670         mh.msg_iov = &iov;
 671         mh.msg_iovlen = 1;
 672         mh.msg_control = &control;
 673         mh.msg_controllen = sizeof(control);
 674
 675         l = recvmsg(fd, &mh, 0);
 676         if (l == 0)
 677                 return 0;
 678         if (l < 0) {
 679                 if (errno == EAGAIN || errno == EINTR)
 680                         return 0;
 681
 682                 return -errno;
 683         }
 684
 685         assert(!(mh.msg_flags & MSG_CTRUNC));
 686         assert(!(mh.msg_flags & MSG_TRUNC));
 687
 688         p->size = (size_t) l;
 689
 690         p->family = sa.sa.sa_family;
 691         p->ipproto = IPPROTO_UDP;
 692         if (p->family == AF_INET) {
 693                 p->sender.in = sa.in.sin_addr;
 694                 p->sender_port = be16toh(sa.in.sin_port);
 695         } else if (p->family == AF_INET6) {
 696                 p->sender.in6 = sa.in6.sin6_addr;
 697                 p->sender_port = be16toh(sa.in6.sin6_port);
 698                 p->ifindex = sa.in6.sin6_scope_id;
 699         } else
 700                 return -EAFNOSUPPORT;
 701
 702         CMSG_FOREACH(cmsg, &mh) {
 703
 704                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 705                         assert(p->family == AF_INET6);
 706
 707                         switch (cmsg->cmsg_type) {
 708
 709                         case IPV6_PKTINFO: {
 710                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 711
 712                                 if (p->ifindex <= 0)
 713                                         p->ifindex = i->ipi6_ifindex;
 714
 715                                 p->destination.in6 = i->ipi6_addr;
 716                                 break;
 717                         }
 718
 719                         case IPV6_HOPLIMIT:
 720                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 721                                 break;
 722
 723                         }
 724                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 725                         assert(p->family == AF_INET);
 726
 727                         switch (cmsg->cmsg_type) {
 728
 729                         case IP_PKTINFO: {
 730                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 731
 732                                 if (p->ifindex <= 0)
 733                                         p->ifindex = i->ipi_ifindex;
 734
 735                                 p->destination.in = i->ipi_addr;
 736                                 break;
 737                         }
 738
 739                         case IP_TTL:
 740                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 741                                 break;
 742                         }
 743                 }
 744         }
 745
 746         /* The Linux kernel sets the interface index to the loopback
 747          * device if the packet came from the local host since it
 748          * avoids the routing table in such a case. Let's unset the
 749          * interface index in such a case. */
 750         if (p->ifindex == LOOPBACK_IFINDEX)
 751                 p->ifindex = 0;
 752
 753         if (protocol != DNS_PROTOCOL_DNS) {
 754                 /* If we don't know the interface index still, we look for the
 755                  * first local interface with a matching address. Yuck! */
 756                 if (p->ifindex <= 0)
 757                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 758         }
 759
 760         *ret = p;
 761         p = NULL;
 762
 763         return 1;
 764 }
 765
 766 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
 767         int r;
 768
 769         assert(fd >= 0);
 770         assert(mh);
 771
 772         for (;;) {
 773                 if (sendmsg(fd, mh, flags) >= 0)
 774                         return 0;
 775
 776                 if (errno == EINTR)
 777                         continue;
 778
 779                 if (errno != EAGAIN)
 780                         return -errno;
 781
 782                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 783                 if (r < 0)
 784                         return r;
 785                 if (r == 0)
 786                         return -ETIMEDOUT;
 787         }
 788 }
 789
 790 static int write_loop(int fd, void *message, size_t length) {
 791         int r;
 792
 793         assert(fd >= 0);
 794         assert(message);
 795
 796         for (;;) {
 797                 if (write(fd, message, length) >= 0)
 798                         return 0;
 799
 800                 if (errno == EINTR)
 801                         continue;
 802
 803                 if (errno != EAGAIN)
 804                         return -errno;
 805
 806                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 807                 if (r < 0)
 808                         return r;
 809                 if (r == 0)
 810                         return -ETIMEDOUT;
 811         }
 812 }
 813
 814 int manager_write(Manager *m, int fd, DnsPacket *p) {
 815         int r;
 816
 817         log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
 818
 819         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
 820         if (r < 0)
 821                 return r;
 822
 823         return 0;
 824 }
 825
 826 static int manager_ipv4_send(
 827                 Manager *m,
 828                 int fd,
 829                 int ifindex,
 830                 const struct in_addr *destination,
 831                 uint16_t port,
 832                 const struct in_addr *source,
 833                 DnsPacket *p) {
 834         union sockaddr_union sa = {
 835                 .in.sin_family = AF_INET,
 836         };
 837         union {
 838                 struct cmsghdr header; /* For alignment */
 839                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
 840         } control;
 841         struct msghdr mh = {};
 842         struct iovec iov;
 843
 844         assert(m);
 845         assert(fd >= 0);
 846         assert(destination);
 847         assert(port > 0);
 848         assert(p);
 849
 850         iov.iov_base = DNS_PACKET_DATA(p);
 851         iov.iov_len = p->size;
 852
 853         sa.in.sin_addr = *destination;
 854         sa.in.sin_port = htobe16(port),
 855
 856         mh.msg_iov = &iov;
 857         mh.msg_iovlen = 1;
 858         mh.msg_name = &sa.sa;
 859         mh.msg_namelen = sizeof(sa.in);
 860
 861         if (ifindex > 0) {
 862                 struct cmsghdr *cmsg;
 863                 struct in_pktinfo *pi;
 864
 865                 zero(control);
 866
 867                 mh.msg_control = &control;
 868                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
 869
 870                 cmsg = CMSG_FIRSTHDR(&mh);
 871                 cmsg->cmsg_len = mh.msg_controllen;
 872                 cmsg->cmsg_level = IPPROTO_IP;
 873                 cmsg->cmsg_type = IP_PKTINFO;
 874
 875                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
 876                 pi->ipi_ifindex = ifindex;
 877
 878                 if (source)
 879                         pi->ipi_spec_dst = *source;
 880         }
 881
 882         return sendmsg_loop(fd, &mh, 0);
 883 }
 884
 885 static int manager_ipv6_send(
 886                 Manager *m,
 887                 int fd,
 888                 int ifindex,
 889                 const struct in6_addr *destination,
 890                 uint16_t port,
 891                 const struct in6_addr *source,
 892                 DnsPacket *p) {
 893
 894         union sockaddr_union sa = {
 895                 .in6.sin6_family = AF_INET6,
 896         };
 897         union {
 898                 struct cmsghdr header; /* For alignment */
 899                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 900         } control;
 901         struct msghdr mh = {};
 902         struct iovec iov;
 903
 904         assert(m);
 905         assert(fd >= 0);
 906         assert(destination);
 907         assert(port > 0);
 908         assert(p);
 909
 910         iov.iov_base = DNS_PACKET_DATA(p);
 911         iov.iov_len = p->size;
 912
 913         sa.in6.sin6_addr = *destination;
 914         sa.in6.sin6_port = htobe16(port),
 915         sa.in6.sin6_scope_id = ifindex;
 916
 917         mh.msg_iov = &iov;
 918         mh.msg_iovlen = 1;
 919         mh.msg_name = &sa.sa;
 920         mh.msg_namelen = sizeof(sa.in6);
 921
 922         if (ifindex > 0) {
 923                 struct cmsghdr *cmsg;
 924                 struct in6_pktinfo *pi;
 925
 926                 zero(control);
 927
 928                 mh.msg_control = &control;
 929                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
 930
 931                 cmsg = CMSG_FIRSTHDR(&mh);
 932                 cmsg->cmsg_len = mh.msg_controllen;
 933                 cmsg->cmsg_level = IPPROTO_IPV6;
 934                 cmsg->cmsg_type = IPV6_PKTINFO;
 935
 936                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 937                 pi->ipi6_ifindex = ifindex;
 938
 939                 if (source)
 940                         pi->ipi6_addr = *source;
 941         }
 942
 943         return sendmsg_loop(fd, &mh, 0);
 944 }
 945
 946 int manager_send(
 947                 Manager *m,
 948                 int fd,
 949                 int ifindex,
 950                 int family,
 951                 const union in_addr_union *destination,
 952                 uint16_t port,
 953                 const union in_addr_union *source,
 954                 DnsPacket *p) {
 955
 956         assert(m);
 957         assert(fd >= 0);
 958         assert(destination);
 959         assert(port > 0);
 960         assert(p);
 961
 962         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));
 963
 964         if (family == AF_INET)
 965                 return manager_ipv4_send(m, fd, ifindex, &destination->in, port, &source->in, p);
 966         if (family == AF_INET6)
 967                 return manager_ipv6_send(m, fd, ifindex, &destination->in6, port, &source->in6, p);
 968
 969         return -EAFNOSUPPORT;
 970 }
 971
 972 uint32_t manager_find_mtu(Manager *m) {
 973         uint32_t mtu = 0;
 974         Link *l;
 975         Iterator i;
 976
 977         /* If we don't know on which link a DNS packet would be
 978          * delivered, let's find the largest MTU that works on all
 979          * interfaces we know of */
 980
 981         HASHMAP_FOREACH(l, m->links, i) {
 982                 if (l->mtu <= 0)
 983                         continue;
 984
 985                 if (mtu <= 0 || l->mtu < mtu)
 986                         mtu = l->mtu;
 987         }
 988
 989         return mtu;
 990 }
 991
 992 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
 993         LinkAddress *a;
 994
 995         assert(m);
 996
 997         a = manager_find_link_address(m, family, in_addr);
 998         if (a)
 999                 return a->link->ifindex;
1000
1001         return 0;
1002 }
1003
1004 void manager_refresh_rrs(Manager *m) {
1005         Iterator i;
1006         Link *l;
1007
1008         assert(m);
1009
1010         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
1011         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
1012         m->mdns_host_ipv4_key = dns_resource_key_unref(m->mdns_host_ipv4_key);
1013         m->mdns_host_ipv6_key = dns_resource_key_unref(m->mdns_host_ipv6_key);
1014
1015         HASHMAP_FOREACH(l, m->links, i) {
1016                 link_add_rrs(l, true);
1017                 link_add_rrs(l, false);
1018         }
1019 }
1020
1021 int manager_next_hostname(Manager *m) {
1022         const char *p;
1023         uint64_t u, a;
1024         char *h, *k;
1025         int r;
1026
1027         assert(m);
1028
1029         p = strchr(m->llmnr_hostname, 0);
1030         assert(p);
1031
1032         while (p > m->llmnr_hostname) {
1033                 if (!strchr("0123456789", p[-1]))
1034                         break;
1035
1036                 p--;
1037         }
1038
1039         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
1040                 u = 1;
1041
1042         /* Add a random number to the old value. This way we can avoid
1043          * that two hosts pick the same hostname, win on IPv4 and lose
1044          * on IPv6 (or vice versa), and pick the same hostname
1045          * replacement hostname, ad infinitum. We still want the
1046          * numbers to go up monotonically, hence we just add a random
1047          * value 1..10 */
1048
1049         random_bytes(&a, sizeof(a));
1050         u += 1 + a % 10;
1051
1052         if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0)
1053                 return -ENOMEM;
1054
1055         r = dns_name_concat(h, "local", &k);
1056         if (r < 0) {
1057                 free(h);
1058                 return r;
1059         }
1060
1061         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1062
1063         free(m->llmnr_hostname);
1064         m->llmnr_hostname = h;
1065
1066         free(m->mdns_hostname);
1067         m->mdns_hostname = k;
1068
1069         manager_refresh_rrs(m);
1070
1071         return 0;
1072 }
1073
1074 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1075         Iterator i;
1076         Link *l;
1077
1078         assert(m);
1079
1080         HASHMAP_FOREACH(l, m->links, i) {
1081                 LinkAddress *a;
1082
1083                 a = link_find_address(l, family, in_addr);
1084                 if (a)
1085                         return a;
1086         }
1087
1088         return NULL;
1089 }
1090
1091 bool manager_our_packet(Manager *m, DnsPacket *p) {
1092         assert(m);
1093         assert(p);
1094
1095         return !!manager_find_link_address(m, p->family, &p->sender);
1096 }
1097
1098 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1099         Link *l;
1100
1101         assert(m);
1102         assert(p);
1103
1104         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1105         if (!l)
1106                 return NULL;
1107
1108         switch (p->protocol) {
1109         case DNS_PROTOCOL_LLMNR:
1110                 if (p->family == AF_INET)
1111                         return l->llmnr_ipv4_scope;
1112                 else if (p->family == AF_INET6)
1113                         return l->llmnr_ipv6_scope;
1114
1115                 break;
1116
1117         case DNS_PROTOCOL_MDNS:
1118                 if (p->family == AF_INET)
1119                         return l->mdns_ipv4_scope;
1120                 else if (p->family == AF_INET6)
1121                         return l->mdns_ipv6_scope;
1122
1123                 break;
1124
1125         default:
1126                 break;
1127         }
1128
1129         return NULL;
1130 }
1131
1132 void manager_verify_all(Manager *m) {
1133         DnsScope *s;
1134
1135         assert(m);
1136
1137         LIST_FOREACH(scopes, s, m->dns_scopes)
1138                 dns_zone_verify_all(&s->zone);
1139 }
1140
1141 int manager_is_own_hostname(Manager *m, const char *name) {
1142         int r;
1143
1144         assert(m);
1145         assert(name);
1146
1147         if (m->llmnr_hostname) {
1148                 r = dns_name_equal(name, m->llmnr_hostname);
1149                 if (r != 0)
1150                         return r;
1151         }
1152
1153         if (m->mdns_hostname)
1154                 return dns_name_equal(name, m->mdns_hostname);
1155
1156         return 0;
1157 }
1158
1159 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1160         DnsServer *s;
1161         Iterator i;
1162         Link *l;
1163         int r;
1164
1165         assert(m);
1166         assert(dns);
1167
1168         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1169         if (r < 0)
1170                 return r;
1171
1172         /* First add the system-wide servers and domains */
1173         LIST_FOREACH(servers, s, m->dns_servers) {
1174                 r = ordered_set_put(*dns, s);
1175                 if (r == -EEXIST)
1176                         continue;
1177                 if (r < 0)
1178                         return r;
1179         }
1180
1181         /* Then, add the per-link servers */
1182         HASHMAP_FOREACH(l, m->links, i) {
1183                 LIST_FOREACH(servers, s, l->dns_servers) {
1184                         r = ordered_set_put(*dns, s);
1185                         if (r == -EEXIST)
1186                                 continue;
1187                         if (r < 0)
1188                                 return r;
1189                 }
1190         }
1191
1192         /* If we found nothing, add the fallback servers */
1193         if (ordered_set_isempty(*dns)) {
1194                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1195                         r = ordered_set_put(*dns, s);
1196                         if (r == -EEXIST)
1197                                 continue;
1198                         if (r < 0)
1199                                 return r;
1200                 }
1201         }
1202
1203         return 0;
1204 }
1205
1206 /* filter_route is a tri-state:
1207  *   < 0: no filtering
1208  *   = 0 or false: return only domains which should be used for searching
1209  *   > 0 or true: return only domains which are for routing only
1210  */
1211 int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) {
1212         DnsSearchDomain *d;
1213         Iterator i;
1214         Link *l;
1215         int r;
1216
1217         assert(m);
1218         assert(domains);
1219
1220         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1221         if (r < 0)
1222                 return r;
1223
1224         LIST_FOREACH(domains, d, m->search_domains) {
1225
1226                 if (filter_route >= 0 &&
1227                     d->route_only != !!filter_route)
1228                         continue;
1229
1230                 r = ordered_set_put(*domains, d->name);
1231                 if (r == -EEXIST)
1232                         continue;
1233                 if (r < 0)
1234                         return r;
1235         }
1236
1237         HASHMAP_FOREACH(l, m->links, i) {
1238
1239                 LIST_FOREACH(domains, d, l->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
1253         return 0;
1254 }
1255
1256 DnssecMode manager_get_dnssec_mode(Manager *m) {
1257         assert(m);
1258
1259         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1260                 return m->dnssec_mode;
1261
1262         return DNSSEC_NO;
1263 }
1264
1265 bool manager_dnssec_supported(Manager *m) {
1266         DnsServer *server;
1267         Iterator i;
1268         Link *l;
1269
1270         assert(m);
1271
1272         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1273                 return false;
1274
1275         server = manager_get_dns_server(m);
1276         if (server && !dns_server_dnssec_supported(server))
1277                 return false;
1278
1279         HASHMAP_FOREACH(l, m->links, i)
1280                 if (!link_dnssec_supported(l))
1281                         return false;
1282
1283         return true;
1284 }
1285
1286 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1287
1288         assert(verdict >= 0);
1289         assert(verdict < _DNSSEC_VERDICT_MAX);
1290
1291         if (log_get_max_level() >= LOG_DEBUG) {
1292                 char s[DNS_RESOURCE_KEY_STRING_MAX];
1293
1294                 log_debug("Found verdict for lookup %s: %s",
1295                           dns_resource_key_to_string(key, s, sizeof s),
1296                           dnssec_verdict_to_string(verdict));
1297         }
1298
1299         m->n_dnssec_verdict[verdict]++;
1300 }
1301
1302 bool manager_routable(Manager *m, int family) {
1303         Iterator i;
1304         Link *l;
1305
1306         assert(m);
1307
1308         /* Returns true if the host has at least one interface with a routable address of the specified type */
1309
1310         HASHMAP_FOREACH(l, m->links, i)
1311                 if (link_relevant(l, family, false))
1312                         return true;
1313
1314         return false;
1315 }
1316
1317 void manager_flush_caches(Manager *m) {
1318         DnsScope *scope;
1319
1320         assert(m);
1321
1322         LIST_FOREACH(scopes, scope, m->dns_scopes)
1323                 dns_cache_flush(&scope->cache);
1324
1325         log_info("Flushed all caches.");
1326 }
1327
1328 void manager_cleanup_saved_user(Manager *m) {
1329         _cleanup_closedir_ DIR *d = NULL;
1330         struct dirent *de;
1331         int r;
1332
1333         assert(m);
1334
1335         /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface
1336          * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can
1337          * be restarted without losing this data. */
1338
1339         d = opendir("/run/systemd/resolve/netif/");
1340         if (!d) {
1341                 if (errno == ENOENT)
1342                         return;
1343
1344                 log_warning_errno(errno, "Failed to open interface directory: %m");
1345                 return;
1346         }
1347
1348         FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) {
1349                 _cleanup_free_ char *p = NULL;
1350                 int ifindex;
1351                 Link *l;
1352
1353                 if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG))
1354                         continue;
1355
1356                 if (STR_IN_SET(de->d_name, ".", ".."))
1357                         continue;
1358
1359                 r = parse_ifindex(de->d_name, &ifindex);
1360                 if (r < 0) /* Probably some temporary file from a previous run. Delete it */
1361                         goto rm;
1362
1363                 l = hashmap_get(m->links, INT_TO_PTR(ifindex));
1364                 if (!l) /* link vanished */
1365                         goto rm;
1366
1367                 if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */
1368                         goto rm;
1369
1370                 continue;
1371
1372         rm:
1373                 p = strappend("/run/systemd/resolve/netif/", de->d_name);
1374                 if (!p) {
1375                         log_oom();
1376                         return;
1377                 }
1378
1379                 (void) unlink(p);
1380         }
1381 }