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-etc-hosts.h"
  40 #include "resolved-llmnr.h"
  41 #include "resolved-manager.h"
  42 #include "resolved-mdns.h"
  43 #include "resolved-resolv-conf.h"
  44 #include "socket-util.h"
  45 #include "string-table.h"
  46 #include "string-util.h"
  47 #include "utf8.h"
  48
  49 #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
  50
  51 static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
  52         Manager *m = userdata;
  53         uint16_t type;
  54         Link *l;
  55         int ifindex, r;
  56
  57         assert(rtnl);
  58         assert(m);
  59         assert(mm);
  60
  61         r = sd_netlink_message_get_type(mm, &type);
  62         if (r < 0)
  63                 goto fail;
  64
  65         r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
  66         if (r < 0)
  67                 goto fail;
  68
  69         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
  70
  71         switch (type) {
  72
  73         case RTM_NEWLINK:{
  74                 bool is_new = !l;
  75
  76                 if (!l) {
  77                         r = link_new(m, &l, ifindex);
  78                         if (r < 0)
  79                                 goto fail;
  80                 }
  81
  82                 r = link_process_rtnl(l, mm);
  83                 if (r < 0)
  84                         goto fail;
  85
  86                 r = link_update(l);
  87                 if (r < 0)
  88                         goto fail;
  89
  90                 if (is_new)
  91                         log_debug("Found new link %i/%s", ifindex, l->name);
  92
  93                 break;
  94         }
  95
  96         case RTM_DELLINK:
  97                 if (l) {
  98                         log_debug("Removing link %i/%s", l->ifindex, l->name);
  99                         link_remove_user(l);
 100                         link_free(l);
 101                 }
 102
 103                 break;
 104         }
 105
 106         return 0;
 107
 108 fail:
 109         log_warning_errno(r, "Failed to process RTNL link message: %m");
 110         return 0;
 111 }
 112
 113 static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
 114         Manager *m = userdata;
 115         union in_addr_union address;
 116         uint16_t type;
 117         int r, ifindex, family;
 118         LinkAddress *a;
 119         Link *l;
 120
 121         assert(rtnl);
 122         assert(mm);
 123         assert(m);
 124
 125         r = sd_netlink_message_get_type(mm, &type);
 126         if (r < 0)
 127                 goto fail;
 128
 129         r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
 130         if (r < 0)
 131                 goto fail;
 132
 133         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
 134         if (!l)
 135                 return 0;
 136
 137         r = sd_rtnl_message_addr_get_family(mm, &family);
 138         if (r < 0)
 139                 goto fail;
 140
 141         switch (family) {
 142
 143         case AF_INET:
 144                 r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in);
 145                 if (r < 0) {
 146                         r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
 147                         if (r < 0)
 148                                 goto fail;
 149                 }
 150
 151                 break;
 152
 153         case AF_INET6:
 154                 r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
 155                 if (r < 0) {
 156                         r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
 157                         if (r < 0)
 158                                 goto fail;
 159                 }
 160
 161                 break;
 162
 163         default:
 164                 return 0;
 165         }
 166
 167         a = link_find_address(l, family, &address);
 168
 169         switch (type) {
 170
 171         case RTM_NEWADDR:
 172
 173                 if (!a) {
 174                         r = link_address_new(l, &a, family, &address);
 175                         if (r < 0)
 176                                 return r;
 177                 }
 178
 179                 r = link_address_update_rtnl(a, mm);
 180                 if (r < 0)
 181                         return r;
 182
 183                 break;
 184
 185         case RTM_DELADDR:
 186                 link_address_free(a);
 187                 break;
 188         }
 189
 190         return 0;
 191
 192 fail:
 193         log_warning_errno(r, "Failed to process RTNL address message: %m");
 194         return 0;
 195 }
 196
 197 static int manager_rtnl_listen(Manager *m) {
 198         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
 199         sd_netlink_message *i;
 200         int r;
 201
 202         assert(m);
 203
 204         /* First, subscribe to interfaces coming and going */
 205         r = sd_netlink_open(&m->rtnl);
 206         if (r < 0)
 207                 return r;
 208
 209         r = sd_netlink_attach_event(m->rtnl, m->event, SD_EVENT_PRIORITY_IMPORTANT);
 210         if (r < 0)
 211                 return r;
 212
 213         r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);
 214         if (r < 0)
 215                 return r;
 216
 217         r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);
 218         if (r < 0)
 219                 return r;
 220
 221         r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);
 222         if (r < 0)
 223                 return r;
 224
 225         r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m);
 226         if (r < 0)
 227                 return r;
 228
 229         /* Then, enumerate all links */
 230         r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
 231         if (r < 0)
 232                 return r;
 233
 234         r = sd_netlink_message_request_dump(req, true);
 235         if (r < 0)
 236                 return r;
 237
 238         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 239         if (r < 0)
 240                 return r;
 241
 242         for (i = reply; i; i = sd_netlink_message_next(i)) {
 243                 r = manager_process_link(m->rtnl, i, m);
 244                 if (r < 0)
 245                         return r;
 246         }
 247
 248         req = sd_netlink_message_unref(req);
 249         reply = sd_netlink_message_unref(reply);
 250
 251         /* Finally, enumerate all addresses, too */
 252         r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
 253         if (r < 0)
 254                 return r;
 255
 256         r = sd_netlink_message_request_dump(req, true);
 257         if (r < 0)
 258                 return r;
 259
 260         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 261         if (r < 0)
 262                 return r;
 263
 264         for (i = reply; i; i = sd_netlink_message_next(i)) {
 265                 r = manager_process_address(m->rtnl, i, m);
 266                 if (r < 0)
 267                         return r;
 268         }
 269
 270         return r;
 271 }
 272
 273 static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 274         Manager *m = userdata;
 275         Iterator i;
 276         Link *l;
 277         int r;
 278
 279         assert(m);
 280
 281         sd_network_monitor_flush(m->network_monitor);
 282
 283         HASHMAP_FOREACH(l, m->links, i) {
 284                 r = link_update(l);
 285                 if (r < 0)
 286                         log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
 287         }
 288
 289         (void) manager_write_resolv_conf(m);
 290
 291         return 0;
 292 }
 293
 294 static int manager_network_monitor_listen(Manager *m) {
 295         int r, fd, events;
 296
 297         assert(m);
 298
 299         r = sd_network_monitor_new(&m->network_monitor, NULL);
 300         if (r < 0)
 301                 return r;
 302
 303         fd = sd_network_monitor_get_fd(m->network_monitor);
 304         if (fd < 0)
 305                 return fd;
 306
 307         events = sd_network_monitor_get_events(m->network_monitor);
 308         if (events < 0)
 309                 return events;
 310
 311         r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m);
 312         if (r < 0)
 313                 return r;
 314
 315         r = sd_event_source_set_priority(m->network_event_source, SD_EVENT_PRIORITY_IMPORTANT+5);
 316         if (r < 0)
 317                 return r;
 318
 319         (void) sd_event_source_set_description(m->network_event_source, "network-monitor");
 320
 321         return 0;
 322 }
 323
 324 static int determine_hostname(char **llmnr_hostname, char **mdns_hostname) {
 325         _cleanup_free_ char *h = NULL, *n = NULL;
 326         char label[DNS_LABEL_MAX];
 327         const char *p;
 328         int r, k;
 329
 330         assert(llmnr_hostname);
 331         assert(mdns_hostname);
 332
 333         /* Extract and normalize the first label of the locally
 334          * configured hostname, and check it's not "localhost". */
 335
 336         h = gethostname_malloc();
 337         if (!h)
 338                 return log_oom();
 339
 340         p = h;
 341         r = dns_label_unescape(&p, label, sizeof(label));
 342         if (r < 0)
 343                 return log_error_errno(r, "Failed to unescape host name: %m");
 344         if (r == 0) {
 345                 log_error("Couldn't find a single label in hosntame.");
 346                 return -EINVAL;
 347         }
 348
 349         k = dns_label_undo_idna(label, r, label, sizeof(label));
 350         if (k < 0)
 351                 return log_error_errno(k, "Failed to undo IDNA: %m");
 352         if (k > 0)
 353                 r = k;
 354
 355         if (!utf8_is_valid(label)) {
 356                 log_error("System hostname is not UTF-8 clean.");
 357                 return -EINVAL;
 358         }
 359
 360         r = dns_label_escape_new(label, r, &n);
 361         if (r < 0)
 362                 return log_error_errno(r, "Failed to escape host name: %m");
 363
 364         if (is_localhost(n)) {
 365                 log_debug("System hostname is 'localhost', ignoring.");
 366                 return -EINVAL;
 367         }
 368
 369         r = dns_name_concat(n, "local", mdns_hostname);
 370         if (r < 0)
 371                 return log_error_errno(r, "Failed to determine mDNS hostname: %m");
 372
 373         *llmnr_hostname = n;
 374         n = NULL;
 375
 376         return 0;
 377 }
 378
 379 static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
 380         _cleanup_free_ char *llmnr_hostname = NULL, *mdns_hostname = NULL;
 381         Manager *m = userdata;
 382         int r;
 383
 384         assert(m);
 385
 386         r = determine_hostname(&llmnr_hostname, &mdns_hostname);
 387         if (r < 0)
 388                 return 0; /* ignore invalid hostnames */
 389
 390         if (streq(llmnr_hostname, m->llmnr_hostname) && streq(mdns_hostname, m->mdns_hostname))
 391                 return 0;
 392
 393         log_info("System hostname changed to '%s'.", llmnr_hostname);
 394
 395         free(m->llmnr_hostname);
 396         free(m->mdns_hostname);
 397
 398         m->llmnr_hostname = llmnr_hostname;
 399         m->mdns_hostname = mdns_hostname;
 400
 401         llmnr_hostname = mdns_hostname = NULL;
 402
 403         manager_refresh_rrs(m);
 404
 405         return 0;
 406 }
 407
 408 static int manager_watch_hostname(Manager *m) {
 409         int r;
 410
 411         assert(m);
 412
 413         m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY);
 414         if (m->hostname_fd < 0) {
 415                 log_warning_errno(errno, "Failed to watch hostname: %m");
 416                 return 0;
 417         }
 418
 419         r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
 420         if (r < 0) {
 421                 if (r == -EPERM)
 422                         /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
 423                         m->hostname_fd = safe_close(m->hostname_fd);
 424                 else
 425                         return log_error_errno(r, "Failed to add hostname event source: %m");
 426         }
 427
 428         (void) sd_event_source_set_description(m->hostname_event_source, "hostname");
 429
 430         r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname);
 431         if (r < 0) {
 432                 log_info("Defaulting to hostname 'linux'.");
 433                 m->llmnr_hostname = strdup("linux");
 434                 if (!m->llmnr_hostname)
 435                         return log_oom();
 436
 437                 m->mdns_hostname = strdup("linux.local");
 438                 if (!m->mdns_hostname)
 439                         return log_oom();
 440         } else
 441                 log_info("Using system hostname '%s'.", m->llmnr_hostname);
 442
 443         return 0;
 444 }
 445
 446 static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 447         _cleanup_free_ char *buffer = NULL;
 448         _cleanup_fclose_ FILE *f = NULL;
 449         Manager *m = userdata;
 450         size_t size = 0;
 451         DnsScope *scope;
 452
 453         assert(s);
 454         assert(si);
 455         assert(m);
 456
 457         f = open_memstream(&buffer, &size);
 458         if (!f)
 459                 return log_oom();
 460
 461         LIST_FOREACH(scopes, scope, m->dns_scopes)
 462                 dns_scope_dump(scope, f);
 463
 464         if (fflush_and_check(f) < 0)
 465                 return log_oom();
 466
 467         log_dump(LOG_INFO, buffer);
 468         return 0;
 469 }
 470
 471 static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
 472         Manager *m = userdata;
 473
 474         assert(s);
 475         assert(si);
 476         assert(m);
 477
 478         manager_flush_caches(m);
 479
 480         return 0;
 481 }
 482
 483 int manager_new(Manager **ret) {
 484         _cleanup_(manager_freep) Manager *m = NULL;
 485         int r;
 486
 487         assert(ret);
 488
 489         m = new0(Manager, 1);
 490         if (!m)
 491                 return -ENOMEM;
 492
 493         m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
 494         m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
 495         m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1;
 496         m->hostname_fd = -1;
 497
 498         m->llmnr_support = RESOLVE_SUPPORT_YES;
 499         m->mdns_support = RESOLVE_SUPPORT_NO;
 500         m->dnssec_mode = DEFAULT_DNSSEC_MODE;
 501         m->read_resolv_conf = true;
 502         m->need_builtin_fallbacks = true;
 503         m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY;
 504
 505         r = dns_trust_anchor_load(&m->trust_anchor);
 506         if (r < 0)
 507                 return r;
 508
 509         r = manager_parse_config_file(m);
 510         if (r < 0)
 511                 return r;
 512
 513         r = sd_event_default(&m->event);
 514         if (r < 0)
 515                 return r;
 516
 517         sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
 518         sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
 519
 520         sd_event_set_watchdog(m->event, true);
 521
 522         r = manager_watch_hostname(m);
 523         if (r < 0)
 524                 return r;
 525
 526         r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 527         if (r < 0)
 528                 return r;
 529
 530         r = manager_network_monitor_listen(m);
 531         if (r < 0)
 532                 return r;
 533
 534         r = manager_rtnl_listen(m);
 535         if (r < 0)
 536                 return r;
 537
 538         r = manager_connect_bus(m);
 539         if (r < 0)
 540                 return r;
 541
 542         (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m);
 543         (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m);
 544
 545         manager_cleanup_saved_user(m);
 546
 547         *ret = m;
 548         m = NULL;
 549
 550         return 0;
 551 }
 552
 553 int manager_start(Manager *m) {
 554         int r;
 555
 556         assert(m);
 557
 558         r = manager_llmnr_start(m);
 559         if (r < 0)
 560                 return r;
 561
 562         r = manager_mdns_start(m);
 563         if (r < 0)
 564                 return r;
 565
 566         return 0;
 567 }
 568
 569 Manager *manager_free(Manager *m) {
 570         Link *l;
 571
 572         if (!m)
 573                 return NULL;
 574
 575         dns_server_unlink_all(m->dns_servers);
 576         dns_server_unlink_all(m->fallback_dns_servers);
 577         dns_search_domain_unlink_all(m->search_domains);
 578
 579         while ((l = hashmap_first(m->links)))
 580                link_free(l);
 581
 582         while (m->dns_queries)
 583                 dns_query_free(m->dns_queries);
 584
 585         dns_scope_free(m->unicast_scope);
 586
 587         hashmap_free(m->links);
 588         hashmap_free(m->dns_transactions);
 589
 590         sd_event_source_unref(m->network_event_source);
 591         sd_network_monitor_unref(m->network_monitor);
 592
 593         sd_netlink_unref(m->rtnl);
 594         sd_event_source_unref(m->rtnl_event_source);
 595
 596         manager_llmnr_stop(m);
 597         manager_mdns_stop(m);
 598
 599         sd_bus_slot_unref(m->prepare_for_sleep_slot);
 600         sd_event_source_unref(m->bus_retry_event_source);
 601         sd_bus_unref(m->bus);
 602
 603         sd_event_source_unref(m->sigusr1_event_source);
 604         sd_event_source_unref(m->sigusr2_event_source);
 605
 606         sd_event_unref(m->event);
 607
 608         dns_resource_key_unref(m->llmnr_host_ipv4_key);
 609         dns_resource_key_unref(m->llmnr_host_ipv6_key);
 610
 611         sd_event_source_unref(m->hostname_event_source);
 612         safe_close(m->hostname_fd);
 613         free(m->llmnr_hostname);
 614         free(m->mdns_hostname);
 615
 616         dns_trust_anchor_flush(&m->trust_anchor);
 617         manager_etc_hosts_flush(m);
 618
 619         free(m);
 620
 621         return NULL;
 622 }
 623
 624 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 625         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 626         union {
 627                 struct cmsghdr header; /* For alignment */
 628                 uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 629                                + CMSG_SPACE(int) /* ttl/hoplimit */
 630                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
 631         } control;
 632         union sockaddr_union sa;
 633         struct msghdr mh = {};
 634         struct cmsghdr *cmsg;
 635         struct iovec iov;
 636         ssize_t ms, l;
 637         int r;
 638
 639         assert(m);
 640         assert(fd >= 0);
 641         assert(ret);
 642
 643         ms = next_datagram_size_fd(fd);
 644         if (ms < 0)
 645                 return ms;
 646
 647         r = dns_packet_new(&p, protocol, ms);
 648         if (r < 0)
 649                 return r;
 650
 651         iov.iov_base = DNS_PACKET_DATA(p);
 652         iov.iov_len = p->allocated;
 653
 654         mh.msg_name = &sa.sa;
 655         mh.msg_namelen = sizeof(sa);
 656         mh.msg_iov = &iov;
 657         mh.msg_iovlen = 1;
 658         mh.msg_control = &control;
 659         mh.msg_controllen = sizeof(control);
 660
 661         l = recvmsg(fd, &mh, 0);
 662         if (l == 0)
 663                 return 0;
 664         if (l < 0) {
 665                 if (errno == EAGAIN || errno == EINTR)
 666                         return 0;
 667
 668                 return -errno;
 669         }
 670
 671         assert(!(mh.msg_flags & MSG_CTRUNC));
 672         assert(!(mh.msg_flags & MSG_TRUNC));
 673
 674         p->size = (size_t) l;
 675
 676         p->family = sa.sa.sa_family;
 677         p->ipproto = IPPROTO_UDP;
 678         if (p->family == AF_INET) {
 679                 p->sender.in = sa.in.sin_addr;
 680                 p->sender_port = be16toh(sa.in.sin_port);
 681         } else if (p->family == AF_INET6) {
 682                 p->sender.in6 = sa.in6.sin6_addr;
 683                 p->sender_port = be16toh(sa.in6.sin6_port);
 684                 p->ifindex = sa.in6.sin6_scope_id;
 685         } else
 686                 return -EAFNOSUPPORT;
 687
 688         CMSG_FOREACH(cmsg, &mh) {
 689
 690                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 691                         assert(p->family == AF_INET6);
 692
 693                         switch (cmsg->cmsg_type) {
 694
 695                         case IPV6_PKTINFO: {
 696                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 697
 698                                 if (p->ifindex <= 0)
 699                                         p->ifindex = i->ipi6_ifindex;
 700
 701                                 p->destination.in6 = i->ipi6_addr;
 702                                 break;
 703                         }
 704
 705                         case IPV6_HOPLIMIT:
 706                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 707                                 break;
 708
 709                         }
 710                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 711                         assert(p->family == AF_INET);
 712
 713                         switch (cmsg->cmsg_type) {
 714
 715                         case IP_PKTINFO: {
 716                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 717
 718                                 if (p->ifindex <= 0)
 719                                         p->ifindex = i->ipi_ifindex;
 720
 721                                 p->destination.in = i->ipi_addr;
 722                                 break;
 723                         }
 724
 725                         case IP_TTL:
 726                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 727                                 break;
 728                         }
 729                 }
 730         }
 731
 732         /* The Linux kernel sets the interface index to the loopback
 733          * device if the packet came from the local host since it
 734          * avoids the routing table in such a case. Let's unset the
 735          * interface index in such a case. */
 736         if (p->ifindex == LOOPBACK_IFINDEX)
 737                 p->ifindex = 0;
 738
 739         if (protocol != DNS_PROTOCOL_DNS) {
 740                 /* If we don't know the interface index still, we look for the
 741                  * first local interface with a matching address. Yuck! */
 742                 if (p->ifindex <= 0)
 743                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 744         }
 745
 746         *ret = p;
 747         p = NULL;
 748
 749         return 1;
 750 }
 751
 752 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
 753         int r;
 754
 755         assert(fd >= 0);
 756         assert(mh);
 757
 758         for (;;) {
 759                 if (sendmsg(fd, mh, flags) >= 0)
 760                         return 0;
 761
 762                 if (errno == EINTR)
 763                         continue;
 764
 765                 if (errno != EAGAIN)
 766                         return -errno;
 767
 768                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 769                 if (r < 0)
 770                         return r;
 771                 if (r == 0)
 772                         return -ETIMEDOUT;
 773         }
 774 }
 775
 776 static int write_loop(int fd, void *message, size_t length) {
 777         int r;
 778
 779         assert(fd >= 0);
 780         assert(message);
 781
 782         for (;;) {
 783                 if (write(fd, message, length) >= 0)
 784                         return 0;
 785
 786                 if (errno == EINTR)
 787                         continue;
 788
 789                 if (errno != EAGAIN)
 790                         return -errno;
 791
 792                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 793                 if (r < 0)
 794                         return r;
 795                 if (r == 0)
 796                         return -ETIMEDOUT;
 797         }
 798 }
 799
 800 int manager_write(Manager *m, int fd, DnsPacket *p) {
 801         int r;
 802
 803         log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
 804
 805         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
 806         if (r < 0)
 807                 return r;
 808
 809         return 0;
 810 }
 811
 812 static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) {
 813         union sockaddr_union sa = {
 814                 .in.sin_family = AF_INET,
 815         };
 816         union {
 817                 struct cmsghdr header; /* For alignment */
 818                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
 819         } control;
 820         struct msghdr mh = {};
 821         struct iovec iov;
 822
 823         assert(m);
 824         assert(fd >= 0);
 825         assert(addr);
 826         assert(port > 0);
 827         assert(p);
 828
 829         iov.iov_base = DNS_PACKET_DATA(p);
 830         iov.iov_len = p->size;
 831
 832         sa.in.sin_addr = *addr;
 833         sa.in.sin_port = htobe16(port),
 834
 835         mh.msg_iov = &iov;
 836         mh.msg_iovlen = 1;
 837         mh.msg_name = &sa.sa;
 838         mh.msg_namelen = sizeof(sa.in);
 839
 840         if (ifindex > 0) {
 841                 struct cmsghdr *cmsg;
 842                 struct in_pktinfo *pi;
 843
 844                 zero(control);
 845
 846                 mh.msg_control = &control;
 847                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
 848
 849                 cmsg = CMSG_FIRSTHDR(&mh);
 850                 cmsg->cmsg_len = mh.msg_controllen;
 851                 cmsg->cmsg_level = IPPROTO_IP;
 852                 cmsg->cmsg_type = IP_PKTINFO;
 853
 854                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
 855                 pi->ipi_ifindex = ifindex;
 856         }
 857
 858         return sendmsg_loop(fd, &mh, 0);
 859 }
 860
 861 static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) {
 862         union sockaddr_union sa = {
 863                 .in6.sin6_family = AF_INET6,
 864         };
 865         union {
 866                 struct cmsghdr header; /* For alignment */
 867                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 868         } control;
 869         struct msghdr mh = {};
 870         struct iovec iov;
 871
 872         assert(m);
 873         assert(fd >= 0);
 874         assert(addr);
 875         assert(port > 0);
 876         assert(p);
 877
 878         iov.iov_base = DNS_PACKET_DATA(p);
 879         iov.iov_len = p->size;
 880
 881         sa.in6.sin6_addr = *addr;
 882         sa.in6.sin6_port = htobe16(port),
 883         sa.in6.sin6_scope_id = ifindex;
 884
 885         mh.msg_iov = &iov;
 886         mh.msg_iovlen = 1;
 887         mh.msg_name = &sa.sa;
 888         mh.msg_namelen = sizeof(sa.in6);
 889
 890         if (ifindex > 0) {
 891                 struct cmsghdr *cmsg;
 892                 struct in6_pktinfo *pi;
 893
 894                 zero(control);
 895
 896                 mh.msg_control = &control;
 897                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
 898
 899                 cmsg = CMSG_FIRSTHDR(&mh);
 900                 cmsg->cmsg_len = mh.msg_controllen;
 901                 cmsg->cmsg_level = IPPROTO_IPV6;
 902                 cmsg->cmsg_type = IPV6_PKTINFO;
 903
 904                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 905                 pi->ipi6_ifindex = ifindex;
 906         }
 907
 908         return sendmsg_loop(fd, &mh, 0);
 909 }
 910
 911 int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) {
 912         assert(m);
 913         assert(fd >= 0);
 914         assert(addr);
 915         assert(port > 0);
 916         assert(p);
 917
 918         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));
 919
 920         if (family == AF_INET)
 921                 return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p);
 922         if (family == AF_INET6)
 923                 return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p);
 924
 925         return -EAFNOSUPPORT;
 926 }
 927
 928 uint32_t manager_find_mtu(Manager *m) {
 929         uint32_t mtu = 0;
 930         Link *l;
 931         Iterator i;
 932
 933         /* If we don't know on which link a DNS packet would be
 934          * delivered, let's find the largest MTU that works on all
 935          * interfaces we know of */
 936
 937         HASHMAP_FOREACH(l, m->links, i) {
 938                 if (l->mtu <= 0)
 939                         continue;
 940
 941                 if (mtu <= 0 || l->mtu < mtu)
 942                         mtu = l->mtu;
 943         }
 944
 945         return mtu;
 946 }
 947
 948 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
 949         LinkAddress *a;
 950
 951         assert(m);
 952
 953         a = manager_find_link_address(m, family, in_addr);
 954         if (a)
 955                 return a->link->ifindex;
 956
 957         return 0;
 958 }
 959
 960 void manager_refresh_rrs(Manager *m) {
 961         Iterator i;
 962         Link *l;
 963
 964         assert(m);
 965
 966         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
 967         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
 968
 969         HASHMAP_FOREACH(l, m->links, i) {
 970                 link_add_rrs(l, true);
 971                 link_add_rrs(l, false);
 972         }
 973 }
 974
 975 int manager_next_hostname(Manager *m) {
 976         const char *p;
 977         uint64_t u, a;
 978         char *h, *k;
 979         int r;
 980
 981         assert(m);
 982
 983         p = strchr(m->llmnr_hostname, 0);
 984         assert(p);
 985
 986         while (p > m->llmnr_hostname) {
 987                 if (!strchr("0123456789", p[-1]))
 988                         break;
 989
 990                 p--;
 991         }
 992
 993         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
 994                 u = 1;
 995
 996         /* Add a random number to the old value. This way we can avoid
 997          * that two hosts pick the same hostname, win on IPv4 and lose
 998          * on IPv6 (or vice versa), and pick the same hostname
 999          * replacement hostname, ad infinitum. We still want the
1000          * numbers to go up monotonically, hence we just add a random
1001          * value 1..10 */
1002
1003         random_bytes(&a, sizeof(a));
1004         u += 1 + a % 10;
1005
1006         if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0)
1007                 return -ENOMEM;
1008
1009         r = dns_name_concat(h, "local", &k);
1010         if (r < 0) {
1011                 free(h);
1012                 return r;
1013         }
1014
1015         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1016
1017         free(m->llmnr_hostname);
1018         m->llmnr_hostname = h;
1019
1020         free(m->mdns_hostname);
1021         m->mdns_hostname = k;
1022
1023         manager_refresh_rrs(m);
1024
1025         return 0;
1026 }
1027
1028 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1029         Iterator i;
1030         Link *l;
1031
1032         assert(m);
1033
1034         HASHMAP_FOREACH(l, m->links, i) {
1035                 LinkAddress *a;
1036
1037                 a = link_find_address(l, family, in_addr);
1038                 if (a)
1039                         return a;
1040         }
1041
1042         return NULL;
1043 }
1044
1045 bool manager_our_packet(Manager *m, DnsPacket *p) {
1046         assert(m);
1047         assert(p);
1048
1049         return !!manager_find_link_address(m, p->family, &p->sender);
1050 }
1051
1052 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1053         Link *l;
1054
1055         assert(m);
1056         assert(p);
1057
1058         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1059         if (!l)
1060                 return NULL;
1061
1062         switch (p->protocol) {
1063         case DNS_PROTOCOL_LLMNR:
1064                 if (p->family == AF_INET)
1065                         return l->llmnr_ipv4_scope;
1066                 else if (p->family == AF_INET6)
1067                         return l->llmnr_ipv6_scope;
1068
1069                 break;
1070
1071         case DNS_PROTOCOL_MDNS:
1072                 if (p->family == AF_INET)
1073                         return l->mdns_ipv4_scope;
1074                 else if (p->family == AF_INET6)
1075                         return l->mdns_ipv6_scope;
1076
1077                 break;
1078
1079         default:
1080                 break;
1081         }
1082
1083         return NULL;
1084 }
1085
1086 void manager_verify_all(Manager *m) {
1087         DnsScope *s;
1088
1089         assert(m);
1090
1091         LIST_FOREACH(scopes, s, m->dns_scopes)
1092                 dns_zone_verify_all(&s->zone);
1093 }
1094
1095 int manager_is_own_hostname(Manager *m, const char *name) {
1096         int r;
1097
1098         assert(m);
1099         assert(name);
1100
1101         if (m->llmnr_hostname) {
1102                 r = dns_name_equal(name, m->llmnr_hostname);
1103                 if (r != 0)
1104                         return r;
1105         }
1106
1107         if (m->mdns_hostname)
1108                 return dns_name_equal(name, m->mdns_hostname);
1109
1110         return 0;
1111 }
1112
1113 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1114         DnsServer *s;
1115         Iterator i;
1116         Link *l;
1117         int r;
1118
1119         assert(m);
1120         assert(dns);
1121
1122         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1123         if (r < 0)
1124                 return r;
1125
1126         /* First add the system-wide servers and domains */
1127         LIST_FOREACH(servers, s, m->dns_servers) {
1128                 r = ordered_set_put(*dns, s);
1129                 if (r == -EEXIST)
1130                         continue;
1131                 if (r < 0)
1132                         return r;
1133         }
1134
1135         /* Then, add the per-link servers */
1136         HASHMAP_FOREACH(l, m->links, i) {
1137                 LIST_FOREACH(servers, s, l->dns_servers) {
1138                         r = ordered_set_put(*dns, s);
1139                         if (r == -EEXIST)
1140                                 continue;
1141                         if (r < 0)
1142                                 return r;
1143                 }
1144         }
1145
1146         /* If we found nothing, add the fallback servers */
1147         if (ordered_set_isempty(*dns)) {
1148                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1149                         r = ordered_set_put(*dns, s);
1150                         if (r == -EEXIST)
1151                                 continue;
1152                         if (r < 0)
1153                                 return r;
1154                 }
1155         }
1156
1157         return 0;
1158 }
1159
1160 int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) {
1161         DnsSearchDomain *d;
1162         Iterator i;
1163         Link *l;
1164         int r;
1165
1166         assert(m);
1167         assert(domains);
1168
1169         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1170         if (r < 0)
1171                 return r;
1172
1173         LIST_FOREACH(domains, d, m->search_domains) {
1174
1175                 if (filter_route >= 0 &&
1176                     d->route_only != !!filter_route)
1177                         continue;
1178
1179                 r = ordered_set_put(*domains, d->name);
1180                 if (r == -EEXIST)
1181                         continue;
1182                 if (r < 0)
1183                         return r;
1184         }
1185
1186         HASHMAP_FOREACH(l, m->links, i) {
1187
1188                 LIST_FOREACH(domains, d, l->search_domains) {
1189
1190                         if (filter_route >= 0 &&
1191                             d->route_only != !!filter_route)
1192                                 continue;
1193
1194                         r = ordered_set_put(*domains, d->name);
1195                         if (r == -EEXIST)
1196                                 continue;
1197                         if (r < 0)
1198                                 return r;
1199                 }
1200         }
1201
1202         return 0;
1203 }
1204
1205 DnssecMode manager_get_dnssec_mode(Manager *m) {
1206         assert(m);
1207
1208         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1209                 return m->dnssec_mode;
1210
1211         return DNSSEC_NO;
1212 }
1213
1214 bool manager_dnssec_supported(Manager *m) {
1215         DnsServer *server;
1216         Iterator i;
1217         Link *l;
1218
1219         assert(m);
1220
1221         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1222                 return false;
1223
1224         server = manager_get_dns_server(m);
1225         if (server && !dns_server_dnssec_supported(server))
1226                 return false;
1227
1228         HASHMAP_FOREACH(l, m->links, i)
1229                 if (!link_dnssec_supported(l))
1230                         return false;
1231
1232         return true;
1233 }
1234
1235 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1236
1237         assert(verdict >= 0);
1238         assert(verdict < _DNSSEC_VERDICT_MAX);
1239
1240         if (log_get_max_level() >= LOG_DEBUG) {
1241                 char s[DNS_RESOURCE_KEY_STRING_MAX];
1242
1243                 log_debug("Found verdict for lookup %s: %s",
1244                           dns_resource_key_to_string(key, s, sizeof s),
1245                           dnssec_verdict_to_string(verdict));
1246         }
1247
1248         m->n_dnssec_verdict[verdict]++;
1249 }
1250
1251 bool manager_routable(Manager *m, int family) {
1252         Iterator i;
1253         Link *l;
1254
1255         assert(m);
1256
1257         /* Returns true if the host has at least one interface with a routable address of the specified type */
1258
1259         HASHMAP_FOREACH(l, m->links, i)
1260                 if (link_relevant(l, family, false))
1261                         return true;
1262
1263         return false;
1264 }
1265
1266 void manager_flush_caches(Manager *m) {
1267         DnsScope *scope;
1268
1269         assert(m);
1270
1271         LIST_FOREACH(scopes, scope, m->dns_scopes)
1272                 dns_cache_flush(&scope->cache);
1273
1274         log_info("Flushed all caches.");
1275 }
1276
1277 void manager_cleanup_saved_user(Manager *m) {
1278         _cleanup_closedir_ DIR *d = NULL;
1279         struct dirent *de;
1280         int r;
1281
1282         assert(m);
1283
1284         /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface
1285          * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can
1286          * be restarted without losing this data. */
1287
1288         d = opendir("/run/systemd/resolve/netif/");
1289         if (!d) {
1290                 if (errno == ENOENT)
1291                         return;
1292
1293                 log_warning_errno(errno, "Failed to open interface directory: %m");
1294                 return;
1295         }
1296
1297         FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) {
1298                 _cleanup_free_ char *p = NULL;
1299                 int ifindex;
1300                 Link *l;
1301
1302                 if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG))
1303                         continue;
1304
1305                 if (STR_IN_SET(de->d_name, ".", ".."))
1306                         continue;
1307
1308                 r = parse_ifindex(de->d_name, &ifindex);
1309                 if (r < 0) /* Probably some temporary file from a previous run. Delete it */
1310                         goto rm;
1311
1312                 l = hashmap_get(m->links, INT_TO_PTR(ifindex));
1313                 if (!l) /* link vanished */
1314                         goto rm;
1315
1316                 if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */
1317                         goto rm;
1318
1319                 continue;
1320
1321         rm:
1322                 p = strappend("/run/systemd/resolve/netif/", de->d_name);
1323                 if (!p) {
1324                         log_oom();
1325                         return;
1326                 }
1327
1328                 (void) unlink(p);
1329         }
1330 }