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 "dns-domain.h"
  27 #include "fd-util.h"
  28 #include "fileio-label.h"
  29 #include "hostname-util.h"
  30 #include "io-util.h"
  31 #include "netlink-util.h"
  32 #include "network-internal.h"
  33 #include "ordered-set.h"
  34 #include "parse-util.h"
  35 #include "random-util.h"
  36 #include "resolved-bus.h"
  37 #include "resolved-conf.h"
  38 #include "resolved-etc-hosts.h"
  39 #include "resolved-llmnr.h"
  40 #include "resolved-manager.h"
  41 #include "resolved-mdns.h"
  42 #include "resolved-resolv-conf.h"
  43 #include "socket-util.h"
  44 #include "string-table.h"
  45 #include "string-util.h"
  46 #include "utf8.h"
  47
  48 #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
  49
  50 static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
  51         Manager *m = userdata;
  52         uint16_t type;
  53         Link *l;
  54         int ifindex, r;
  55
  56         assert(rtnl);
  57         assert(m);
  58         assert(mm);
  59
  60         r = sd_netlink_message_get_type(mm, &type);
  61         if (r < 0)
  62                 goto fail;
  63
  64         r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
  65         if (r < 0)
  66                 goto fail;
  67
  68         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
  69
  70         switch (type) {
  71
  72         case RTM_NEWLINK:{
  73                 bool is_new = !l;
  74
  75                 if (!l) {
  76                         r = link_new(m, &l, ifindex);
  77                         if (r < 0)
  78                                 goto fail;
  79                 }
  80
  81                 r = link_update_rtnl(l, mm);
  82                 if (r < 0)
  83                         goto fail;
  84
  85                 r = link_update_monitor(l);
  86                 if (r < 0)
  87                         goto fail;
  88
  89                 if (is_new)
  90                         log_debug("Found new link %i/%s", ifindex, l->name);
  91
  92                 break;
  93         }
  94
  95         case RTM_DELLINK:
  96                 if (l) {
  97                         log_debug("Removing link %i/%s", l->ifindex, l->name);
  98                         link_free(l);
  99                 }
 100
 101                 break;
 102         }
 103
 104         return 0;
 105
 106 fail:
 107         log_warning_errno(r, "Failed to process RTNL link message: %m");
 108         return 0;
 109 }
 110
 111 static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
 112         Manager *m = userdata;
 113         union in_addr_union address;
 114         uint16_t type;
 115         int r, ifindex, family;
 116         LinkAddress *a;
 117         Link *l;
 118
 119         assert(rtnl);
 120         assert(mm);
 121         assert(m);
 122
 123         r = sd_netlink_message_get_type(mm, &type);
 124         if (r < 0)
 125                 goto fail;
 126
 127         r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
 128         if (r < 0)
 129                 goto fail;
 130
 131         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
 132         if (!l)
 133                 return 0;
 134
 135         r = sd_rtnl_message_addr_get_family(mm, &family);
 136         if (r < 0)
 137                 goto fail;
 138
 139         switch (family) {
 140
 141         case AF_INET:
 142                 r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in);
 143                 if (r < 0) {
 144                         r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
 145                         if (r < 0)
 146                                 goto fail;
 147                 }
 148
 149                 break;
 150
 151         case AF_INET6:
 152                 r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
 153                 if (r < 0) {
 154                         r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
 155                         if (r < 0)
 156                                 goto fail;
 157                 }
 158
 159                 break;
 160
 161         default:
 162                 return 0;
 163         }
 164
 165         a = link_find_address(l, family, &address);
 166
 167         switch (type) {
 168
 169         case RTM_NEWADDR:
 170
 171                 if (!a) {
 172                         r = link_address_new(l, &a, family, &address);
 173                         if (r < 0)
 174                                 return r;
 175                 }
 176
 177                 r = link_address_update_rtnl(a, mm);
 178                 if (r < 0)
 179                         return r;
 180
 181                 break;
 182
 183         case RTM_DELADDR:
 184                 link_address_free(a);
 185                 break;
 186         }
 187
 188         return 0;
 189
 190 fail:
 191         log_warning_errno(r, "Failed to process RTNL address message: %m");
 192         return 0;
 193 }
 194
 195 static int manager_rtnl_listen(Manager *m) {
 196         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
 197         sd_netlink_message *i;
 198         int r;
 199
 200         assert(m);
 201
 202         /* First, subscribe to interfaces coming and going */
 203         r = sd_netlink_open(&m->rtnl);
 204         if (r < 0)
 205                 return r;
 206
 207         r = sd_netlink_attach_event(m->rtnl, m->event, SD_EVENT_PRIORITY_IMPORTANT);
 208         if (r < 0)
 209                 return r;
 210
 211         r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);
 212         if (r < 0)
 213                 return r;
 214
 215         r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);
 216         if (r < 0)
 217                 return r;
 218
 219         r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);
 220         if (r < 0)
 221                 return r;
 222
 223         r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m);
 224         if (r < 0)
 225                 return r;
 226
 227         /* Then, enumerate all links */
 228         r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
 229         if (r < 0)
 230                 return r;
 231
 232         r = sd_netlink_message_request_dump(req, true);
 233         if (r < 0)
 234                 return r;
 235
 236         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 237         if (r < 0)
 238                 return r;
 239
 240         for (i = reply; i; i = sd_netlink_message_next(i)) {
 241                 r = manager_process_link(m->rtnl, i, m);
 242                 if (r < 0)
 243                         return r;
 244         }
 245
 246         req = sd_netlink_message_unref(req);
 247         reply = sd_netlink_message_unref(reply);
 248
 249         /* Finally, enumerate all addresses, too */
 250         r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
 251         if (r < 0)
 252                 return r;
 253
 254         r = sd_netlink_message_request_dump(req, true);
 255         if (r < 0)
 256                 return r;
 257
 258         r = sd_netlink_call(m->rtnl, req, 0, &reply);
 259         if (r < 0)
 260                 return r;
 261
 262         for (i = reply; i; i = sd_netlink_message_next(i)) {
 263                 r = manager_process_address(m->rtnl, i, m);
 264                 if (r < 0)
 265                         return r;
 266         }
 267
 268         return r;
 269 }
 270
 271 static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 272         Manager *m = userdata;
 273         Iterator i;
 274         Link *l;
 275         int r;
 276
 277         assert(m);
 278
 279         sd_network_monitor_flush(m->network_monitor);
 280
 281         HASHMAP_FOREACH(l, m->links, i) {
 282                 r = link_update_monitor(l);
 283                 if (r < 0)
 284                         log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
 285         }
 286
 287         r = manager_write_resolv_conf(m);
 288         if (r < 0)
 289                 log_warning_errno(r, "Could not update "PRIVATE_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 int manager_new(Manager **ret) {
 472         _cleanup_(manager_freep) Manager *m = NULL;
 473         int r;
 474
 475         assert(ret);
 476
 477         m = new0(Manager, 1);
 478         if (!m)
 479                 return -ENOMEM;
 480
 481         m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
 482         m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
 483         m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1;
 484         m->hostname_fd = -1;
 485
 486         m->llmnr_support = RESOLVE_SUPPORT_YES;
 487         m->mdns_support = RESOLVE_SUPPORT_NO;
 488         m->dnssec_mode = DNSSEC_NO;
 489         m->read_resolv_conf = true;
 490         m->need_builtin_fallbacks = true;
 491         m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY;
 492
 493         r = dns_trust_anchor_load(&m->trust_anchor);
 494         if (r < 0)
 495                 return r;
 496
 497         r = manager_parse_config_file(m);
 498         if (r < 0)
 499                 return r;
 500
 501         r = sd_event_default(&m->event);
 502         if (r < 0)
 503                 return r;
 504
 505         sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
 506         sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
 507
 508         sd_event_set_watchdog(m->event, true);
 509
 510         r = manager_watch_hostname(m);
 511         if (r < 0)
 512                 return r;
 513
 514         r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
 515         if (r < 0)
 516                 return r;
 517
 518         r = manager_network_monitor_listen(m);
 519         if (r < 0)
 520                 return r;
 521
 522         r = manager_rtnl_listen(m);
 523         if (r < 0)
 524                 return r;
 525
 526         r = manager_connect_bus(m);
 527         if (r < 0)
 528                 return r;
 529
 530         (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m);
 531
 532         *ret = m;
 533         m = NULL;
 534
 535         return 0;
 536 }
 537
 538 int manager_start(Manager *m) {
 539         int r;
 540
 541         assert(m);
 542
 543         r = manager_llmnr_start(m);
 544         if (r < 0)
 545                 return r;
 546
 547         r = manager_mdns_start(m);
 548         if (r < 0)
 549                 return r;
 550
 551         return 0;
 552 }
 553
 554 Manager *manager_free(Manager *m) {
 555         Link *l;
 556
 557         if (!m)
 558                 return NULL;
 559
 560         dns_server_unlink_all(m->dns_servers);
 561         dns_server_unlink_all(m->fallback_dns_servers);
 562         dns_search_domain_unlink_all(m->search_domains);
 563
 564         while ((l = hashmap_first(m->links)))
 565                link_free(l);
 566
 567         while (m->dns_queries)
 568                 dns_query_free(m->dns_queries);
 569
 570         dns_scope_free(m->unicast_scope);
 571
 572         hashmap_free(m->links);
 573         hashmap_free(m->dns_transactions);
 574
 575         sd_event_source_unref(m->network_event_source);
 576         sd_network_monitor_unref(m->network_monitor);
 577
 578         sd_netlink_unref(m->rtnl);
 579         sd_event_source_unref(m->rtnl_event_source);
 580
 581         manager_llmnr_stop(m);
 582         manager_mdns_stop(m);
 583
 584         sd_bus_slot_unref(m->prepare_for_sleep_slot);
 585         sd_event_source_unref(m->bus_retry_event_source);
 586         sd_bus_unref(m->bus);
 587
 588         sd_event_source_unref(m->sigusr1_event_source);
 589
 590         sd_event_unref(m->event);
 591
 592         dns_resource_key_unref(m->llmnr_host_ipv4_key);
 593         dns_resource_key_unref(m->llmnr_host_ipv6_key);
 594
 595         sd_event_source_unref(m->hostname_event_source);
 596         safe_close(m->hostname_fd);
 597         free(m->llmnr_hostname);
 598         free(m->mdns_hostname);
 599
 600         dns_trust_anchor_flush(&m->trust_anchor);
 601         manager_etc_hosts_flush(m);
 602
 603         free(m);
 604
 605         return NULL;
 606 }
 607
 608 int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
 609         _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
 610         union {
 611                 struct cmsghdr header; /* For alignment */
 612                 uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
 613                                + CMSG_SPACE(int) /* ttl/hoplimit */
 614                                + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
 615         } control;
 616         union sockaddr_union sa;
 617         struct msghdr mh = {};
 618         struct cmsghdr *cmsg;
 619         struct iovec iov;
 620         int ms = 0, r;
 621         ssize_t l;
 622
 623         assert(m);
 624         assert(fd >= 0);
 625         assert(ret);
 626
 627         r = ioctl(fd, FIONREAD, &ms);
 628         if (r < 0)
 629                 return -errno;
 630         if (ms < 0)
 631                 return -EIO;
 632
 633         r = dns_packet_new(&p, protocol, ms);
 634         if (r < 0)
 635                 return r;
 636
 637         iov.iov_base = DNS_PACKET_DATA(p);
 638         iov.iov_len = p->allocated;
 639
 640         mh.msg_name = &sa.sa;
 641         mh.msg_namelen = sizeof(sa);
 642         mh.msg_iov = &iov;
 643         mh.msg_iovlen = 1;
 644         mh.msg_control = &control;
 645         mh.msg_controllen = sizeof(control);
 646
 647         l = recvmsg(fd, &mh, 0);
 648         if (l < 0) {
 649                 if (errno == EAGAIN || errno == EINTR)
 650                         return 0;
 651
 652                 return -errno;
 653         }
 654
 655         if (l <= 0)
 656                 return -EIO;
 657
 658         assert(!(mh.msg_flags & MSG_CTRUNC));
 659         assert(!(mh.msg_flags & MSG_TRUNC));
 660
 661         p->size = (size_t) l;
 662
 663         p->family = sa.sa.sa_family;
 664         p->ipproto = IPPROTO_UDP;
 665         if (p->family == AF_INET) {
 666                 p->sender.in = sa.in.sin_addr;
 667                 p->sender_port = be16toh(sa.in.sin_port);
 668         } else if (p->family == AF_INET6) {
 669                 p->sender.in6 = sa.in6.sin6_addr;
 670                 p->sender_port = be16toh(sa.in6.sin6_port);
 671                 p->ifindex = sa.in6.sin6_scope_id;
 672         } else
 673                 return -EAFNOSUPPORT;
 674
 675         CMSG_FOREACH(cmsg, &mh) {
 676
 677                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 678                         assert(p->family == AF_INET6);
 679
 680                         switch (cmsg->cmsg_type) {
 681
 682                         case IPV6_PKTINFO: {
 683                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 684
 685                                 if (p->ifindex <= 0)
 686                                         p->ifindex = i->ipi6_ifindex;
 687
 688                                 p->destination.in6 = i->ipi6_addr;
 689                                 break;
 690                         }
 691
 692                         case IPV6_HOPLIMIT:
 693                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 694                                 break;
 695
 696                         }
 697                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 698                         assert(p->family == AF_INET);
 699
 700                         switch (cmsg->cmsg_type) {
 701
 702                         case IP_PKTINFO: {
 703                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 704
 705                                 if (p->ifindex <= 0)
 706                                         p->ifindex = i->ipi_ifindex;
 707
 708                                 p->destination.in = i->ipi_addr;
 709                                 break;
 710                         }
 711
 712                         case IP_TTL:
 713                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 714                                 break;
 715                         }
 716                 }
 717         }
 718
 719         /* The Linux kernel sets the interface index to the loopback
 720          * device if the packet came from the local host since it
 721          * avoids the routing table in such a case. Let's unset the
 722          * interface index in such a case. */
 723         if (p->ifindex == LOOPBACK_IFINDEX)
 724                 p->ifindex = 0;
 725
 726         if (protocol != DNS_PROTOCOL_DNS) {
 727                 /* If we don't know the interface index still, we look for the
 728                  * first local interface with a matching address. Yuck! */
 729                 if (p->ifindex <= 0)
 730                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 731         }
 732
 733         *ret = p;
 734         p = NULL;
 735
 736         return 1;
 737 }
 738
 739 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
 740         int r;
 741
 742         assert(fd >= 0);
 743         assert(mh);
 744
 745         for (;;) {
 746                 if (sendmsg(fd, mh, flags) >= 0)
 747                         return 0;
 748
 749                 if (errno == EINTR)
 750                         continue;
 751
 752                 if (errno != EAGAIN)
 753                         return -errno;
 754
 755                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 756                 if (r < 0)
 757                         return r;
 758                 if (r == 0)
 759                         return -ETIMEDOUT;
 760         }
 761 }
 762
 763 static int write_loop(int fd, void *message, size_t length) {
 764         int r;
 765
 766         assert(fd >= 0);
 767         assert(message);
 768
 769         for (;;) {
 770                 if (write(fd, message, length) >= 0)
 771                         return 0;
 772
 773                 if (errno == EINTR)
 774                         continue;
 775
 776                 if (errno != EAGAIN)
 777                         return -errno;
 778
 779                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 780                 if (r < 0)
 781                         return r;
 782                 if (r == 0)
 783                         return -ETIMEDOUT;
 784         }
 785 }
 786
 787 int manager_write(Manager *m, int fd, DnsPacket *p) {
 788         int r;
 789
 790         log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
 791
 792         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
 793         if (r < 0)
 794                 return r;
 795
 796         return 0;
 797 }
 798
 799 static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) {
 800         union sockaddr_union sa = {
 801                 .in.sin_family = AF_INET,
 802         };
 803         union {
 804                 struct cmsghdr header; /* For alignment */
 805                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
 806         } control;
 807         struct msghdr mh = {};
 808         struct iovec iov;
 809
 810         assert(m);
 811         assert(fd >= 0);
 812         assert(addr);
 813         assert(port > 0);
 814         assert(p);
 815
 816         iov.iov_base = DNS_PACKET_DATA(p);
 817         iov.iov_len = p->size;
 818
 819         sa.in.sin_addr = *addr;
 820         sa.in.sin_port = htobe16(port),
 821
 822         mh.msg_iov = &iov;
 823         mh.msg_iovlen = 1;
 824         mh.msg_name = &sa.sa;
 825         mh.msg_namelen = sizeof(sa.in);
 826
 827         if (ifindex > 0) {
 828                 struct cmsghdr *cmsg;
 829                 struct in_pktinfo *pi;
 830
 831                 zero(control);
 832
 833                 mh.msg_control = &control;
 834                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
 835
 836                 cmsg = CMSG_FIRSTHDR(&mh);
 837                 cmsg->cmsg_len = mh.msg_controllen;
 838                 cmsg->cmsg_level = IPPROTO_IP;
 839                 cmsg->cmsg_type = IP_PKTINFO;
 840
 841                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
 842                 pi->ipi_ifindex = ifindex;
 843         }
 844
 845         return sendmsg_loop(fd, &mh, 0);
 846 }
 847
 848 static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) {
 849         union sockaddr_union sa = {
 850                 .in6.sin6_family = AF_INET6,
 851         };
 852         union {
 853                 struct cmsghdr header; /* For alignment */
 854                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 855         } control;
 856         struct msghdr mh = {};
 857         struct iovec iov;
 858
 859         assert(m);
 860         assert(fd >= 0);
 861         assert(addr);
 862         assert(port > 0);
 863         assert(p);
 864
 865         iov.iov_base = DNS_PACKET_DATA(p);
 866         iov.iov_len = p->size;
 867
 868         sa.in6.sin6_addr = *addr;
 869         sa.in6.sin6_port = htobe16(port),
 870         sa.in6.sin6_scope_id = ifindex;
 871
 872         mh.msg_iov = &iov;
 873         mh.msg_iovlen = 1;
 874         mh.msg_name = &sa.sa;
 875         mh.msg_namelen = sizeof(sa.in6);
 876
 877         if (ifindex > 0) {
 878                 struct cmsghdr *cmsg;
 879                 struct in6_pktinfo *pi;
 880
 881                 zero(control);
 882
 883                 mh.msg_control = &control;
 884                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
 885
 886                 cmsg = CMSG_FIRSTHDR(&mh);
 887                 cmsg->cmsg_len = mh.msg_controllen;
 888                 cmsg->cmsg_level = IPPROTO_IPV6;
 889                 cmsg->cmsg_type = IPV6_PKTINFO;
 890
 891                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 892                 pi->ipi6_ifindex = ifindex;
 893         }
 894
 895         return sendmsg_loop(fd, &mh, 0);
 896 }
 897
 898 int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) {
 899         assert(m);
 900         assert(fd >= 0);
 901         assert(addr);
 902         assert(port > 0);
 903         assert(p);
 904
 905         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));
 906
 907         if (family == AF_INET)
 908                 return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p);
 909         else if (family == AF_INET6)
 910                 return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p);
 911
 912         return -EAFNOSUPPORT;
 913 }
 914
 915 uint32_t manager_find_mtu(Manager *m) {
 916         uint32_t mtu = 0;
 917         Link *l;
 918         Iterator i;
 919
 920         /* If we don't know on which link a DNS packet would be
 921          * delivered, let's find the largest MTU that works on all
 922          * interfaces we know of */
 923
 924         HASHMAP_FOREACH(l, m->links, i) {
 925                 if (l->mtu <= 0)
 926                         continue;
 927
 928                 if (mtu <= 0 || l->mtu < mtu)
 929                         mtu = l->mtu;
 930         }
 931
 932         return mtu;
 933 }
 934
 935 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
 936         LinkAddress *a;
 937
 938         assert(m);
 939
 940         a = manager_find_link_address(m, family, in_addr);
 941         if (a)
 942                 return a->link->ifindex;
 943
 944         return 0;
 945 }
 946
 947 void manager_refresh_rrs(Manager *m) {
 948         Iterator i;
 949         Link *l;
 950
 951         assert(m);
 952
 953         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
 954         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
 955
 956         HASHMAP_FOREACH(l, m->links, i) {
 957                 link_add_rrs(l, true);
 958                 link_add_rrs(l, false);
 959         }
 960 }
 961
 962 int manager_next_hostname(Manager *m) {
 963         const char *p;
 964         uint64_t u, a;
 965         char *h, *k;
 966         int r;
 967
 968         assert(m);
 969
 970         p = strchr(m->llmnr_hostname, 0);
 971         assert(p);
 972
 973         while (p > m->llmnr_hostname) {
 974                 if (!strchr("0123456789", p[-1]))
 975                         break;
 976
 977                 p--;
 978         }
 979
 980         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
 981                 u = 1;
 982
 983         /* Add a random number to the old value. This way we can avoid
 984          * that two hosts pick the same hostname, win on IPv4 and lose
 985          * on IPv6 (or vice versa), and pick the same hostname
 986          * replacement hostname, ad infinitum. We still want the
 987          * numbers to go up monotonically, hence we just add a random
 988          * value 1..10 */
 989
 990         random_bytes(&a, sizeof(a));
 991         u += 1 + a % 10;
 992
 993         if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0)
 994                 return -ENOMEM;
 995
 996         r = dns_name_concat(h, "local", &k);
 997         if (r < 0) {
 998                 free(h);
 999                 return r;
1000         }
1001
1002         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1003
1004         free(m->llmnr_hostname);
1005         m->llmnr_hostname = h;
1006
1007         free(m->mdns_hostname);
1008         m->mdns_hostname = k;
1009
1010         manager_refresh_rrs(m);
1011
1012         return 0;
1013 }
1014
1015 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1016         Iterator i;
1017         Link *l;
1018
1019         assert(m);
1020
1021         HASHMAP_FOREACH(l, m->links, i) {
1022                 LinkAddress *a;
1023
1024                 a = link_find_address(l, family, in_addr);
1025                 if (a)
1026                         return a;
1027         }
1028
1029         return NULL;
1030 }
1031
1032 bool manager_our_packet(Manager *m, DnsPacket *p) {
1033         assert(m);
1034         assert(p);
1035
1036         return !!manager_find_link_address(m, p->family, &p->sender);
1037 }
1038
1039 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1040         Link *l;
1041
1042         assert(m);
1043         assert(p);
1044
1045         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1046         if (!l)
1047                 return NULL;
1048
1049         switch (p->protocol) {
1050         case DNS_PROTOCOL_LLMNR:
1051                 if (p->family == AF_INET)
1052                         return l->llmnr_ipv4_scope;
1053                 else if (p->family == AF_INET6)
1054                         return l->llmnr_ipv6_scope;
1055
1056                 break;
1057
1058         case DNS_PROTOCOL_MDNS:
1059                 if (p->family == AF_INET)
1060                         return l->mdns_ipv4_scope;
1061                 else if (p->family == AF_INET6)
1062                         return l->mdns_ipv6_scope;
1063
1064                 break;
1065
1066         default:
1067                 break;
1068         }
1069
1070         return NULL;
1071 }
1072
1073 void manager_verify_all(Manager *m) {
1074         DnsScope *s;
1075
1076         assert(m);
1077
1078         LIST_FOREACH(scopes, s, m->dns_scopes)
1079                 dns_zone_verify_all(&s->zone);
1080 }
1081
1082 int manager_is_own_hostname(Manager *m, const char *name) {
1083         int r;
1084
1085         assert(m);
1086         assert(name);
1087
1088         if (m->llmnr_hostname) {
1089                 r = dns_name_equal(name, m->llmnr_hostname);
1090                 if (r != 0)
1091                         return r;
1092         }
1093
1094         if (m->mdns_hostname)
1095                 return dns_name_equal(name, m->mdns_hostname);
1096
1097         return 0;
1098 }
1099
1100 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1101         DnsServer *s;
1102         Iterator i;
1103         Link *l;
1104         int r;
1105
1106         assert(m);
1107         assert(dns);
1108
1109         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1110         if (r < 0)
1111                 return r;
1112
1113         /* First add the system-wide servers and domains */
1114         LIST_FOREACH(servers, s, m->dns_servers) {
1115                 r = ordered_set_put(*dns, s);
1116                 if (r == -EEXIST)
1117                         continue;
1118                 if (r < 0)
1119                         return r;
1120         }
1121
1122         /* Then, add the per-link servers */
1123         HASHMAP_FOREACH(l, m->links, i) {
1124                 LIST_FOREACH(servers, s, l->dns_servers) {
1125                         r = ordered_set_put(*dns, s);
1126                         if (r == -EEXIST)
1127                                 continue;
1128                         if (r < 0)
1129                                 return r;
1130                 }
1131         }
1132
1133         /* If we found nothing, add the fallback servers */
1134         if (ordered_set_isempty(*dns)) {
1135                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1136                         r = ordered_set_put(*dns, s);
1137                         if (r == -EEXIST)
1138                                 continue;
1139                         if (r < 0)
1140                                 return r;
1141                 }
1142         }
1143
1144         return 0;
1145 }
1146
1147 int manager_compile_search_domains(Manager *m, OrderedSet **domains) {
1148         DnsSearchDomain *d;
1149         Iterator i;
1150         Link *l;
1151         int r;
1152
1153         assert(m);
1154         assert(domains);
1155
1156         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1157         if (r < 0)
1158                 return r;
1159
1160         LIST_FOREACH(domains, d, m->search_domains) {
1161                 r = ordered_set_put(*domains, d->name);
1162                 if (r == -EEXIST)
1163                         continue;
1164                 if (r < 0)
1165                         return r;
1166         }
1167
1168         HASHMAP_FOREACH(l, m->links, i) {
1169
1170                 LIST_FOREACH(domains, d, l->search_domains) {
1171                         r = ordered_set_put(*domains, d->name);
1172                         if (r == -EEXIST)
1173                                 continue;
1174                         if (r < 0)
1175                                 return r;
1176                 }
1177         }
1178
1179         return 0;
1180 }
1181
1182 DnssecMode manager_get_dnssec_mode(Manager *m) {
1183         assert(m);
1184
1185         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1186                 return m->dnssec_mode;
1187
1188         return DNSSEC_NO;
1189 }
1190
1191 bool manager_dnssec_supported(Manager *m) {
1192         DnsServer *server;
1193         Iterator i;
1194         Link *l;
1195
1196         assert(m);
1197
1198         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1199                 return false;
1200
1201         server = manager_get_dns_server(m);
1202         if (server && !dns_server_dnssec_supported(server))
1203                 return false;
1204
1205         HASHMAP_FOREACH(l, m->links, i)
1206                 if (!link_dnssec_supported(l))
1207                         return false;
1208
1209         return true;
1210 }
1211
1212 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1213
1214         assert(verdict >= 0);
1215         assert(verdict < _DNSSEC_VERDICT_MAX);
1216
1217         if (log_get_max_level() >= LOG_DEBUG) {
1218                 _cleanup_free_ char *s = NULL;
1219
1220                 (void) dns_resource_key_to_string(key, &s);
1221
1222                 log_debug("Found verdict for lookup %s: %s", s ? strstrip(s) : "n/a", dnssec_verdict_to_string(verdict));
1223         }
1224
1225         m->n_dnssec_verdict[verdict]++;
1226 }
1227
1228 bool manager_routable(Manager *m, int family) {
1229         Iterator i;
1230         Link *l;
1231
1232         assert(m);
1233
1234         /* Returns true if the host has at least one interface with a routable address of the specified type */
1235
1236         HASHMAP_FOREACH(l, m->links, i)
1237                 if (link_relevant(l, family, false))
1238                         return true;
1239
1240         return false;
1241 }