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         ssize_t ms, l;
 621         int r;
 622
 623         assert(m);
 624         assert(fd >= 0);
 625         assert(ret);
 626
 627         ms = next_datagram_size_fd(fd);
 628         if (ms < 0)
 629                 return ms;
 630
 631         r = dns_packet_new(&p, protocol, ms);
 632         if (r < 0)
 633                 return r;
 634
 635         iov.iov_base = DNS_PACKET_DATA(p);
 636         iov.iov_len = p->allocated;
 637
 638         mh.msg_name = &sa.sa;
 639         mh.msg_namelen = sizeof(sa);
 640         mh.msg_iov = &iov;
 641         mh.msg_iovlen = 1;
 642         mh.msg_control = &control;
 643         mh.msg_controllen = sizeof(control);
 644
 645         l = recvmsg(fd, &mh, 0);
 646         if (l < 0) {
 647                 if (errno == EAGAIN || errno == EINTR)
 648                         return 0;
 649
 650                 return -errno;
 651         }
 652
 653         if (l <= 0)
 654                 return -EIO;
 655
 656         assert(!(mh.msg_flags & MSG_CTRUNC));
 657         assert(!(mh.msg_flags & MSG_TRUNC));
 658
 659         p->size = (size_t) l;
 660
 661         p->family = sa.sa.sa_family;
 662         p->ipproto = IPPROTO_UDP;
 663         if (p->family == AF_INET) {
 664                 p->sender.in = sa.in.sin_addr;
 665                 p->sender_port = be16toh(sa.in.sin_port);
 666         } else if (p->family == AF_INET6) {
 667                 p->sender.in6 = sa.in6.sin6_addr;
 668                 p->sender_port = be16toh(sa.in6.sin6_port);
 669                 p->ifindex = sa.in6.sin6_scope_id;
 670         } else
 671                 return -EAFNOSUPPORT;
 672
 673         CMSG_FOREACH(cmsg, &mh) {
 674
 675                 if (cmsg->cmsg_level == IPPROTO_IPV6) {
 676                         assert(p->family == AF_INET6);
 677
 678                         switch (cmsg->cmsg_type) {
 679
 680                         case IPV6_PKTINFO: {
 681                                 struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 682
 683                                 if (p->ifindex <= 0)
 684                                         p->ifindex = i->ipi6_ifindex;
 685
 686                                 p->destination.in6 = i->ipi6_addr;
 687                                 break;
 688                         }
 689
 690                         case IPV6_HOPLIMIT:
 691                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 692                                 break;
 693
 694                         }
 695                 } else if (cmsg->cmsg_level == IPPROTO_IP) {
 696                         assert(p->family == AF_INET);
 697
 698                         switch (cmsg->cmsg_type) {
 699
 700                         case IP_PKTINFO: {
 701                                 struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 702
 703                                 if (p->ifindex <= 0)
 704                                         p->ifindex = i->ipi_ifindex;
 705
 706                                 p->destination.in = i->ipi_addr;
 707                                 break;
 708                         }
 709
 710                         case IP_TTL:
 711                                 p->ttl = *(int *) CMSG_DATA(cmsg);
 712                                 break;
 713                         }
 714                 }
 715         }
 716
 717         /* The Linux kernel sets the interface index to the loopback
 718          * device if the packet came from the local host since it
 719          * avoids the routing table in such a case. Let's unset the
 720          * interface index in such a case. */
 721         if (p->ifindex == LOOPBACK_IFINDEX)
 722                 p->ifindex = 0;
 723
 724         if (protocol != DNS_PROTOCOL_DNS) {
 725                 /* If we don't know the interface index still, we look for the
 726                  * first local interface with a matching address. Yuck! */
 727                 if (p->ifindex <= 0)
 728                         p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
 729         }
 730
 731         *ret = p;
 732         p = NULL;
 733
 734         return 1;
 735 }
 736
 737 static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
 738         int r;
 739
 740         assert(fd >= 0);
 741         assert(mh);
 742
 743         for (;;) {
 744                 if (sendmsg(fd, mh, flags) >= 0)
 745                         return 0;
 746
 747                 if (errno == EINTR)
 748                         continue;
 749
 750                 if (errno != EAGAIN)
 751                         return -errno;
 752
 753                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 754                 if (r < 0)
 755                         return r;
 756                 if (r == 0)
 757                         return -ETIMEDOUT;
 758         }
 759 }
 760
 761 static int write_loop(int fd, void *message, size_t length) {
 762         int r;
 763
 764         assert(fd >= 0);
 765         assert(message);
 766
 767         for (;;) {
 768                 if (write(fd, message, length) >= 0)
 769                         return 0;
 770
 771                 if (errno == EINTR)
 772                         continue;
 773
 774                 if (errno != EAGAIN)
 775                         return -errno;
 776
 777                 r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
 778                 if (r < 0)
 779                         return r;
 780                 if (r == 0)
 781                         return -ETIMEDOUT;
 782         }
 783 }
 784
 785 int manager_write(Manager *m, int fd, DnsPacket *p) {
 786         int r;
 787
 788         log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
 789
 790         r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
 791         if (r < 0)
 792                 return r;
 793
 794         return 0;
 795 }
 796
 797 static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) {
 798         union sockaddr_union sa = {
 799                 .in.sin_family = AF_INET,
 800         };
 801         union {
 802                 struct cmsghdr header; /* For alignment */
 803                 uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
 804         } control;
 805         struct msghdr mh = {};
 806         struct iovec iov;
 807
 808         assert(m);
 809         assert(fd >= 0);
 810         assert(addr);
 811         assert(port > 0);
 812         assert(p);
 813
 814         iov.iov_base = DNS_PACKET_DATA(p);
 815         iov.iov_len = p->size;
 816
 817         sa.in.sin_addr = *addr;
 818         sa.in.sin_port = htobe16(port),
 819
 820         mh.msg_iov = &iov;
 821         mh.msg_iovlen = 1;
 822         mh.msg_name = &sa.sa;
 823         mh.msg_namelen = sizeof(sa.in);
 824
 825         if (ifindex > 0) {
 826                 struct cmsghdr *cmsg;
 827                 struct in_pktinfo *pi;
 828
 829                 zero(control);
 830
 831                 mh.msg_control = &control;
 832                 mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
 833
 834                 cmsg = CMSG_FIRSTHDR(&mh);
 835                 cmsg->cmsg_len = mh.msg_controllen;
 836                 cmsg->cmsg_level = IPPROTO_IP;
 837                 cmsg->cmsg_type = IP_PKTINFO;
 838
 839                 pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
 840                 pi->ipi_ifindex = ifindex;
 841         }
 842
 843         return sendmsg_loop(fd, &mh, 0);
 844 }
 845
 846 static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) {
 847         union sockaddr_union sa = {
 848                 .in6.sin6_family = AF_INET6,
 849         };
 850         union {
 851                 struct cmsghdr header; /* For alignment */
 852                 uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
 853         } control;
 854         struct msghdr mh = {};
 855         struct iovec iov;
 856
 857         assert(m);
 858         assert(fd >= 0);
 859         assert(addr);
 860         assert(port > 0);
 861         assert(p);
 862
 863         iov.iov_base = DNS_PACKET_DATA(p);
 864         iov.iov_len = p->size;
 865
 866         sa.in6.sin6_addr = *addr;
 867         sa.in6.sin6_port = htobe16(port),
 868         sa.in6.sin6_scope_id = ifindex;
 869
 870         mh.msg_iov = &iov;
 871         mh.msg_iovlen = 1;
 872         mh.msg_name = &sa.sa;
 873         mh.msg_namelen = sizeof(sa.in6);
 874
 875         if (ifindex > 0) {
 876                 struct cmsghdr *cmsg;
 877                 struct in6_pktinfo *pi;
 878
 879                 zero(control);
 880
 881                 mh.msg_control = &control;
 882                 mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
 883
 884                 cmsg = CMSG_FIRSTHDR(&mh);
 885                 cmsg->cmsg_len = mh.msg_controllen;
 886                 cmsg->cmsg_level = IPPROTO_IPV6;
 887                 cmsg->cmsg_type = IPV6_PKTINFO;
 888
 889                 pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
 890                 pi->ipi6_ifindex = ifindex;
 891         }
 892
 893         return sendmsg_loop(fd, &mh, 0);
 894 }
 895
 896 int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) {
 897         assert(m);
 898         assert(fd >= 0);
 899         assert(addr);
 900         assert(port > 0);
 901         assert(p);
 902
 903         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));
 904
 905         if (family == AF_INET)
 906                 return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p);
 907         else if (family == AF_INET6)
 908                 return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p);
 909
 910         return -EAFNOSUPPORT;
 911 }
 912
 913 uint32_t manager_find_mtu(Manager *m) {
 914         uint32_t mtu = 0;
 915         Link *l;
 916         Iterator i;
 917
 918         /* If we don't know on which link a DNS packet would be
 919          * delivered, let's find the largest MTU that works on all
 920          * interfaces we know of */
 921
 922         HASHMAP_FOREACH(l, m->links, i) {
 923                 if (l->mtu <= 0)
 924                         continue;
 925
 926                 if (mtu <= 0 || l->mtu < mtu)
 927                         mtu = l->mtu;
 928         }
 929
 930         return mtu;
 931 }
 932
 933 int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
 934         LinkAddress *a;
 935
 936         assert(m);
 937
 938         a = manager_find_link_address(m, family, in_addr);
 939         if (a)
 940                 return a->link->ifindex;
 941
 942         return 0;
 943 }
 944
 945 void manager_refresh_rrs(Manager *m) {
 946         Iterator i;
 947         Link *l;
 948
 949         assert(m);
 950
 951         m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
 952         m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
 953
 954         HASHMAP_FOREACH(l, m->links, i) {
 955                 link_add_rrs(l, true);
 956                 link_add_rrs(l, false);
 957         }
 958 }
 959
 960 int manager_next_hostname(Manager *m) {
 961         const char *p;
 962         uint64_t u, a;
 963         char *h, *k;
 964         int r;
 965
 966         assert(m);
 967
 968         p = strchr(m->llmnr_hostname, 0);
 969         assert(p);
 970
 971         while (p > m->llmnr_hostname) {
 972                 if (!strchr("0123456789", p[-1]))
 973                         break;
 974
 975                 p--;
 976         }
 977
 978         if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
 979                 u = 1;
 980
 981         /* Add a random number to the old value. This way we can avoid
 982          * that two hosts pick the same hostname, win on IPv4 and lose
 983          * on IPv6 (or vice versa), and pick the same hostname
 984          * replacement hostname, ad infinitum. We still want the
 985          * numbers to go up monotonically, hence we just add a random
 986          * value 1..10 */
 987
 988         random_bytes(&a, sizeof(a));
 989         u += 1 + a % 10;
 990
 991         if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0)
 992                 return -ENOMEM;
 993
 994         r = dns_name_concat(h, "local", &k);
 995         if (r < 0) {
 996                 free(h);
 997                 return r;
 998         }
 999
1000         log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
1001
1002         free(m->llmnr_hostname);
1003         m->llmnr_hostname = h;
1004
1005         free(m->mdns_hostname);
1006         m->mdns_hostname = k;
1007
1008         manager_refresh_rrs(m);
1009
1010         return 0;
1011 }
1012
1013 LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
1014         Iterator i;
1015         Link *l;
1016
1017         assert(m);
1018
1019         HASHMAP_FOREACH(l, m->links, i) {
1020                 LinkAddress *a;
1021
1022                 a = link_find_address(l, family, in_addr);
1023                 if (a)
1024                         return a;
1025         }
1026
1027         return NULL;
1028 }
1029
1030 bool manager_our_packet(Manager *m, DnsPacket *p) {
1031         assert(m);
1032         assert(p);
1033
1034         return !!manager_find_link_address(m, p->family, &p->sender);
1035 }
1036
1037 DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
1038         Link *l;
1039
1040         assert(m);
1041         assert(p);
1042
1043         l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
1044         if (!l)
1045                 return NULL;
1046
1047         switch (p->protocol) {
1048         case DNS_PROTOCOL_LLMNR:
1049                 if (p->family == AF_INET)
1050                         return l->llmnr_ipv4_scope;
1051                 else if (p->family == AF_INET6)
1052                         return l->llmnr_ipv6_scope;
1053
1054                 break;
1055
1056         case DNS_PROTOCOL_MDNS:
1057                 if (p->family == AF_INET)
1058                         return l->mdns_ipv4_scope;
1059                 else if (p->family == AF_INET6)
1060                         return l->mdns_ipv6_scope;
1061
1062                 break;
1063
1064         default:
1065                 break;
1066         }
1067
1068         return NULL;
1069 }
1070
1071 void manager_verify_all(Manager *m) {
1072         DnsScope *s;
1073
1074         assert(m);
1075
1076         LIST_FOREACH(scopes, s, m->dns_scopes)
1077                 dns_zone_verify_all(&s->zone);
1078 }
1079
1080 int manager_is_own_hostname(Manager *m, const char *name) {
1081         int r;
1082
1083         assert(m);
1084         assert(name);
1085
1086         if (m->llmnr_hostname) {
1087                 r = dns_name_equal(name, m->llmnr_hostname);
1088                 if (r != 0)
1089                         return r;
1090         }
1091
1092         if (m->mdns_hostname)
1093                 return dns_name_equal(name, m->mdns_hostname);
1094
1095         return 0;
1096 }
1097
1098 int manager_compile_dns_servers(Manager *m, OrderedSet **dns) {
1099         DnsServer *s;
1100         Iterator i;
1101         Link *l;
1102         int r;
1103
1104         assert(m);
1105         assert(dns);
1106
1107         r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops);
1108         if (r < 0)
1109                 return r;
1110
1111         /* First add the system-wide servers and domains */
1112         LIST_FOREACH(servers, s, m->dns_servers) {
1113                 r = ordered_set_put(*dns, s);
1114                 if (r == -EEXIST)
1115                         continue;
1116                 if (r < 0)
1117                         return r;
1118         }
1119
1120         /* Then, add the per-link servers */
1121         HASHMAP_FOREACH(l, m->links, i) {
1122                 LIST_FOREACH(servers, s, l->dns_servers) {
1123                         r = ordered_set_put(*dns, s);
1124                         if (r == -EEXIST)
1125                                 continue;
1126                         if (r < 0)
1127                                 return r;
1128                 }
1129         }
1130
1131         /* If we found nothing, add the fallback servers */
1132         if (ordered_set_isempty(*dns)) {
1133                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
1134                         r = ordered_set_put(*dns, s);
1135                         if (r == -EEXIST)
1136                                 continue;
1137                         if (r < 0)
1138                                 return r;
1139                 }
1140         }
1141
1142         return 0;
1143 }
1144
1145 int manager_compile_search_domains(Manager *m, OrderedSet **domains) {
1146         DnsSearchDomain *d;
1147         Iterator i;
1148         Link *l;
1149         int r;
1150
1151         assert(m);
1152         assert(domains);
1153
1154         r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops);
1155         if (r < 0)
1156                 return r;
1157
1158         LIST_FOREACH(domains, d, m->search_domains) {
1159                 r = ordered_set_put(*domains, d->name);
1160                 if (r == -EEXIST)
1161                         continue;
1162                 if (r < 0)
1163                         return r;
1164         }
1165
1166         HASHMAP_FOREACH(l, m->links, i) {
1167
1168                 LIST_FOREACH(domains, d, l->search_domains) {
1169                         r = ordered_set_put(*domains, d->name);
1170                         if (r == -EEXIST)
1171                                 continue;
1172                         if (r < 0)
1173                                 return r;
1174                 }
1175         }
1176
1177         return 0;
1178 }
1179
1180 DnssecMode manager_get_dnssec_mode(Manager *m) {
1181         assert(m);
1182
1183         if (m->dnssec_mode != _DNSSEC_MODE_INVALID)
1184                 return m->dnssec_mode;
1185
1186         return DNSSEC_NO;
1187 }
1188
1189 bool manager_dnssec_supported(Manager *m) {
1190         DnsServer *server;
1191         Iterator i;
1192         Link *l;
1193
1194         assert(m);
1195
1196         if (manager_get_dnssec_mode(m) == DNSSEC_NO)
1197                 return false;
1198
1199         server = manager_get_dns_server(m);
1200         if (server && !dns_server_dnssec_supported(server))
1201                 return false;
1202
1203         HASHMAP_FOREACH(l, m->links, i)
1204                 if (!link_dnssec_supported(l))
1205                         return false;
1206
1207         return true;
1208 }
1209
1210 void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) {
1211
1212         assert(verdict >= 0);
1213         assert(verdict < _DNSSEC_VERDICT_MAX);
1214
1215         if (log_get_max_level() >= LOG_DEBUG) {
1216                 _cleanup_free_ char *s = NULL;
1217
1218                 (void) dns_resource_key_to_string(key, &s);
1219
1220                 log_debug("Found verdict for lookup %s: %s", s ? strstrip(s) : "n/a", dnssec_verdict_to_string(verdict));
1221         }
1222
1223         m->n_dnssec_verdict[verdict]++;
1224 }
1225
1226 bool manager_routable(Manager *m, int family) {
1227         Iterator i;
1228         Link *l;
1229
1230         assert(m);
1231
1232         /* Returns true if the host has at least one interface with a routable address of the specified type */
1233
1234         HASHMAP_FOREACH(l, m->links, i)
1235                 if (link_relevant(l, family, false))
1236                         return true;
1237
1238         return false;
1239 }