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1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ | |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Tom Gundersen <teg@jklm.no> | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <netinet/in.h> | |
23 | #include <poll.h> | |
24 | #include <sys/ioctl.h> | |
25 | ||
26 | #include "af-list.h" | |
27 | #include "alloc-util.h" | |
28 | #include "dns-domain.h" | |
29 | #include "fd-util.h" | |
30 | #include "fileio-label.h" | |
31 | #include "hostname-util.h" | |
32 | #include "io-util.h" | |
33 | #include "netlink-util.h" | |
34 | #include "network-internal.h" | |
35 | #include "ordered-set.h" | |
36 | #include "parse-util.h" | |
37 | #include "random-util.h" | |
38 | #include "resolved-bus.h" | |
39 | #include "resolved-conf.h" | |
40 | #include "resolved-etc-hosts.h" | |
41 | #include "resolved-llmnr.h" | |
42 | #include "resolved-manager.h" | |
43 | #include "resolved-mdns.h" | |
44 | #include "resolved-resolv-conf.h" | |
45 | #include "socket-util.h" | |
46 | #include "string-table.h" | |
47 | #include "string-util.h" | |
48 | #include "utf8.h" | |
49 | ||
50 | #define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC) | |
51 | ||
52 | static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) { | |
53 | Manager *m = userdata; | |
54 | uint16_t type; | |
55 | Link *l; | |
56 | int ifindex, r; | |
57 | ||
58 | assert(rtnl); | |
59 | assert(m); | |
60 | assert(mm); | |
61 | ||
62 | r = sd_netlink_message_get_type(mm, &type); | |
63 | if (r < 0) | |
64 | goto fail; | |
65 | ||
66 | r = sd_rtnl_message_link_get_ifindex(mm, &ifindex); | |
67 | if (r < 0) | |
68 | goto fail; | |
69 | ||
70 | l = hashmap_get(m->links, INT_TO_PTR(ifindex)); | |
71 | ||
72 | switch (type) { | |
73 | ||
74 | case RTM_NEWLINK:{ | |
75 | bool is_new = !l; | |
76 | ||
77 | if (!l) { | |
78 | r = link_new(m, &l, ifindex); | |
79 | if (r < 0) | |
80 | goto fail; | |
81 | } | |
82 | ||
83 | r = link_update_rtnl(l, mm); | |
84 | if (r < 0) | |
85 | goto fail; | |
86 | ||
87 | r = link_update_monitor(l); | |
88 | if (r < 0) | |
89 | goto fail; | |
90 | ||
91 | if (is_new) | |
92 | log_debug("Found new link %i/%s", ifindex, l->name); | |
93 | ||
94 | break; | |
95 | } | |
96 | ||
97 | case RTM_DELLINK: | |
98 | if (l) { | |
99 | log_debug("Removing link %i/%s", l->ifindex, l->name); | |
100 | link_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, 0); | |
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_monitor(l); | |
285 | if (r < 0) | |
286 | log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex); | |
287 | } | |
288 | ||
289 | r = manager_write_resolv_conf(m); | |
290 | if (r < 0) | |
291 | log_warning_errno(r, "Could not update resolv.conf: %m"); | |
292 | ||
293 | return 0; | |
294 | } | |
295 | ||
296 | static int manager_network_monitor_listen(Manager *m) { | |
297 | int r, fd, events; | |
298 | ||
299 | assert(m); | |
300 | ||
301 | r = sd_network_monitor_new(&m->network_monitor, NULL); | |
302 | if (r < 0) | |
303 | return r; | |
304 | ||
305 | fd = sd_network_monitor_get_fd(m->network_monitor); | |
306 | if (fd < 0) | |
307 | return fd; | |
308 | ||
309 | events = sd_network_monitor_get_events(m->network_monitor); | |
310 | if (events < 0) | |
311 | return events; | |
312 | ||
313 | r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m); | |
314 | if (r < 0) | |
315 | return r; | |
316 | ||
317 | (void) sd_event_source_set_description(m->network_event_source, "network-monitor"); | |
318 | ||
319 | return 0; | |
320 | } | |
321 | ||
322 | static int determine_hostname(char **llmnr_hostname, char **mdns_hostname) { | |
323 | _cleanup_free_ char *h = NULL, *n = NULL; | |
324 | char label[DNS_LABEL_MAX]; | |
325 | const char *p; | |
326 | int r, k; | |
327 | ||
328 | assert(llmnr_hostname); | |
329 | assert(mdns_hostname); | |
330 | ||
331 | /* Extract and normalize the first label of the locally | |
332 | * configured hostname, and check it's not "localhost". */ | |
333 | ||
334 | h = gethostname_malloc(); | |
335 | if (!h) | |
336 | return log_oom(); | |
337 | ||
338 | p = h; | |
339 | r = dns_label_unescape(&p, label, sizeof(label)); | |
340 | if (r < 0) | |
341 | return log_error_errno(r, "Failed to unescape host name: %m"); | |
342 | if (r == 0) { | |
343 | log_error("Couldn't find a single label in hosntame."); | |
344 | return -EINVAL; | |
345 | } | |
346 | ||
347 | k = dns_label_undo_idna(label, r, label, sizeof(label)); | |
348 | if (k < 0) | |
349 | return log_error_errno(k, "Failed to undo IDNA: %m"); | |
350 | if (k > 0) | |
351 | r = k; | |
352 | ||
353 | if (!utf8_is_valid(label)) { | |
354 | log_error("System hostname is not UTF-8 clean."); | |
355 | return -EINVAL; | |
356 | } | |
357 | ||
358 | r = dns_label_escape_new(label, r, &n); | |
359 | if (r < 0) | |
360 | return log_error_errno(r, "Failed to escape host name: %m"); | |
361 | ||
362 | if (is_localhost(n)) { | |
363 | log_debug("System hostname is 'localhost', ignoring."); | |
364 | return -EINVAL; | |
365 | } | |
366 | ||
367 | r = dns_name_concat(n, "local", mdns_hostname); | |
368 | if (r < 0) | |
369 | return log_error_errno(r, "Failed to determine mDNS hostname: %m"); | |
370 | ||
371 | *llmnr_hostname = n; | |
372 | n = NULL; | |
373 | ||
374 | return 0; | |
375 | } | |
376 | ||
377 | static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) { | |
378 | _cleanup_free_ char *llmnr_hostname = NULL, *mdns_hostname = NULL; | |
379 | Manager *m = userdata; | |
380 | int r; | |
381 | ||
382 | assert(m); | |
383 | ||
384 | r = determine_hostname(&llmnr_hostname, &mdns_hostname); | |
385 | if (r < 0) | |
386 | return 0; /* ignore invalid hostnames */ | |
387 | ||
388 | if (streq(llmnr_hostname, m->llmnr_hostname) && streq(mdns_hostname, m->mdns_hostname)) | |
389 | return 0; | |
390 | ||
391 | log_info("System hostname changed to '%s'.", llmnr_hostname); | |
392 | ||
393 | free(m->llmnr_hostname); | |
394 | free(m->mdns_hostname); | |
395 | ||
396 | m->llmnr_hostname = llmnr_hostname; | |
397 | m->mdns_hostname = mdns_hostname; | |
398 | ||
399 | llmnr_hostname = mdns_hostname = NULL; | |
400 | ||
401 | manager_refresh_rrs(m); | |
402 | ||
403 | return 0; | |
404 | } | |
405 | ||
406 | static int manager_watch_hostname(Manager *m) { | |
407 | int r; | |
408 | ||
409 | assert(m); | |
410 | ||
411 | m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY); | |
412 | if (m->hostname_fd < 0) { | |
413 | log_warning_errno(errno, "Failed to watch hostname: %m"); | |
414 | return 0; | |
415 | } | |
416 | ||
417 | r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m); | |
418 | if (r < 0) { | |
419 | if (r == -EPERM) | |
420 | /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */ | |
421 | m->hostname_fd = safe_close(m->hostname_fd); | |
422 | else | |
423 | return log_error_errno(r, "Failed to add hostname event source: %m"); | |
424 | } | |
425 | ||
426 | (void) sd_event_source_set_description(m->hostname_event_source, "hostname"); | |
427 | ||
428 | r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname); | |
429 | if (r < 0) { | |
430 | log_info("Defaulting to hostname 'linux'."); | |
431 | m->llmnr_hostname = strdup("linux"); | |
432 | if (!m->llmnr_hostname) | |
433 | return log_oom(); | |
434 | ||
435 | m->mdns_hostname = strdup("linux.local"); | |
436 | if (!m->mdns_hostname) | |
437 | return log_oom(); | |
438 | } else | |
439 | log_info("Using system hostname '%s'.", m->llmnr_hostname); | |
440 | ||
441 | return 0; | |
442 | } | |
443 | ||
444 | static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { | |
445 | _cleanup_free_ char *buffer = NULL; | |
446 | _cleanup_fclose_ FILE *f = NULL; | |
447 | Manager *m = userdata; | |
448 | size_t size = 0; | |
449 | DnsScope *scope; | |
450 | ||
451 | assert(s); | |
452 | assert(si); | |
453 | assert(m); | |
454 | ||
455 | f = open_memstream(&buffer, &size); | |
456 | if (!f) | |
457 | return log_oom(); | |
458 | ||
459 | LIST_FOREACH(scopes, scope, m->dns_scopes) | |
460 | dns_scope_dump(scope, f); | |
461 | ||
462 | if (fflush_and_check(f) < 0) | |
463 | return log_oom(); | |
464 | ||
465 | log_dump(LOG_INFO, buffer); | |
466 | return 0; | |
467 | } | |
468 | ||
469 | int manager_new(Manager **ret) { | |
470 | _cleanup_(manager_freep) Manager *m = NULL; | |
471 | int r; | |
472 | ||
473 | assert(ret); | |
474 | ||
475 | m = new0(Manager, 1); | |
476 | if (!m) | |
477 | return -ENOMEM; | |
478 | ||
479 | m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; | |
480 | m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; | |
481 | m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1; | |
482 | m->hostname_fd = -1; | |
483 | ||
484 | m->llmnr_support = RESOLVE_SUPPORT_YES; | |
485 | m->mdns_support = RESOLVE_SUPPORT_NO; | |
486 | m->dnssec_mode = DNSSEC_NO; | |
487 | m->read_resolv_conf = true; | |
488 | m->need_builtin_fallbacks = true; | |
489 | m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY; | |
490 | ||
491 | r = dns_trust_anchor_load(&m->trust_anchor); | |
492 | if (r < 0) | |
493 | return r; | |
494 | ||
495 | r = manager_parse_config_file(m); | |
496 | if (r < 0) | |
497 | return r; | |
498 | ||
499 | r = sd_event_default(&m->event); | |
500 | if (r < 0) | |
501 | return r; | |
502 | ||
503 | sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); | |
504 | sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); | |
505 | ||
506 | sd_event_set_watchdog(m->event, true); | |
507 | ||
508 | r = manager_watch_hostname(m); | |
509 | if (r < 0) | |
510 | return r; | |
511 | ||
512 | r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC); | |
513 | if (r < 0) | |
514 | return r; | |
515 | ||
516 | r = manager_network_monitor_listen(m); | |
517 | if (r < 0) | |
518 | return r; | |
519 | ||
520 | r = manager_rtnl_listen(m); | |
521 | if (r < 0) | |
522 | return r; | |
523 | ||
524 | r = manager_connect_bus(m); | |
525 | if (r < 0) | |
526 | return r; | |
527 | ||
528 | (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m); | |
529 | ||
530 | *ret = m; | |
531 | m = NULL; | |
532 | ||
533 | return 0; | |
534 | } | |
535 | ||
536 | int manager_start(Manager *m) { | |
537 | int r; | |
538 | ||
539 | assert(m); | |
540 | ||
541 | r = manager_llmnr_start(m); | |
542 | if (r < 0) | |
543 | return r; | |
544 | ||
545 | r = manager_mdns_start(m); | |
546 | if (r < 0) | |
547 | return r; | |
548 | ||
549 | return 0; | |
550 | } | |
551 | ||
552 | Manager *manager_free(Manager *m) { | |
553 | Link *l; | |
554 | ||
555 | if (!m) | |
556 | return NULL; | |
557 | ||
558 | dns_server_unlink_all(m->dns_servers); | |
559 | dns_server_unlink_all(m->fallback_dns_servers); | |
560 | dns_search_domain_unlink_all(m->search_domains); | |
561 | ||
562 | while ((l = hashmap_first(m->links))) | |
563 | link_free(l); | |
564 | ||
565 | while (m->dns_queries) | |
566 | dns_query_free(m->dns_queries); | |
567 | ||
568 | dns_scope_free(m->unicast_scope); | |
569 | ||
570 | hashmap_free(m->links); | |
571 | hashmap_free(m->dns_transactions); | |
572 | ||
573 | sd_event_source_unref(m->network_event_source); | |
574 | sd_network_monitor_unref(m->network_monitor); | |
575 | ||
576 | sd_netlink_unref(m->rtnl); | |
577 | sd_event_source_unref(m->rtnl_event_source); | |
578 | ||
579 | manager_llmnr_stop(m); | |
580 | manager_mdns_stop(m); | |
581 | ||
582 | sd_bus_slot_unref(m->prepare_for_sleep_slot); | |
583 | sd_event_source_unref(m->bus_retry_event_source); | |
584 | sd_bus_unref(m->bus); | |
585 | ||
586 | sd_event_source_unref(m->sigusr1_event_source); | |
587 | ||
588 | sd_event_unref(m->event); | |
589 | ||
590 | dns_resource_key_unref(m->llmnr_host_ipv4_key); | |
591 | dns_resource_key_unref(m->llmnr_host_ipv6_key); | |
592 | ||
593 | sd_event_source_unref(m->hostname_event_source); | |
594 | safe_close(m->hostname_fd); | |
595 | free(m->llmnr_hostname); | |
596 | free(m->mdns_hostname); | |
597 | ||
598 | dns_trust_anchor_flush(&m->trust_anchor); | |
599 | manager_etc_hosts_flush(m); | |
600 | ||
601 | free(m); | |
602 | ||
603 | return NULL; | |
604 | } | |
605 | ||
606 | int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { | |
607 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
608 | union { | |
609 | struct cmsghdr header; /* For alignment */ | |
610 | uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) | |
611 | + CMSG_SPACE(int) /* ttl/hoplimit */ | |
612 | + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */]; | |
613 | } control; | |
614 | union sockaddr_union sa; | |
615 | struct msghdr mh = {}; | |
616 | struct cmsghdr *cmsg; | |
617 | struct iovec iov; | |
618 | int ms = 0, r; | |
619 | ssize_t l; | |
620 | ||
621 | assert(m); | |
622 | assert(fd >= 0); | |
623 | assert(ret); | |
624 | ||
625 | r = ioctl(fd, FIONREAD, &ms); | |
626 | if (r < 0) | |
627 | return -errno; | |
628 | if (ms < 0) | |
629 | return -EIO; | |
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 | } |