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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 | (void) manager_write_resolv_conf(m); | |
288 | ||
289 | return 0; | |
290 | } | |
291 | ||
292 | static int manager_network_monitor_listen(Manager *m) { | |
293 | int r, fd, events; | |
294 | ||
295 | assert(m); | |
296 | ||
297 | r = sd_network_monitor_new(&m->network_monitor, NULL); | |
298 | if (r < 0) | |
299 | return r; | |
300 | ||
301 | fd = sd_network_monitor_get_fd(m->network_monitor); | |
302 | if (fd < 0) | |
303 | return fd; | |
304 | ||
305 | events = sd_network_monitor_get_events(m->network_monitor); | |
306 | if (events < 0) | |
307 | return events; | |
308 | ||
309 | r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m); | |
310 | if (r < 0) | |
311 | return r; | |
312 | ||
313 | r = sd_event_source_set_priority(m->network_event_source, SD_EVENT_PRIORITY_IMPORTANT+5); | |
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 | static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { | |
470 | Manager *m = userdata; | |
471 | DnsScope *scope; | |
472 | ||
473 | assert(s); | |
474 | assert(si); | |
475 | assert(m); | |
476 | ||
477 | LIST_FOREACH(scopes, scope, m->dns_scopes) | |
478 | dns_cache_flush(&scope->cache); | |
479 | ||
480 | log_info("Flushed all caches."); | |
481 | return 0; | |
482 | } | |
483 | ||
484 | int manager_new(Manager **ret) { | |
485 | _cleanup_(manager_freep) Manager *m = NULL; | |
486 | int r; | |
487 | ||
488 | assert(ret); | |
489 | ||
490 | m = new0(Manager, 1); | |
491 | if (!m) | |
492 | return -ENOMEM; | |
493 | ||
494 | m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; | |
495 | m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; | |
496 | m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1; | |
497 | m->hostname_fd = -1; | |
498 | ||
499 | m->llmnr_support = RESOLVE_SUPPORT_YES; | |
500 | m->mdns_support = RESOLVE_SUPPORT_NO; | |
501 | m->dnssec_mode = DEFAULT_DNSSEC_MODE; | |
502 | m->read_resolv_conf = true; | |
503 | m->need_builtin_fallbacks = true; | |
504 | m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY; | |
505 | ||
506 | r = dns_trust_anchor_load(&m->trust_anchor); | |
507 | if (r < 0) | |
508 | return r; | |
509 | ||
510 | r = manager_parse_config_file(m); | |
511 | if (r < 0) | |
512 | return r; | |
513 | ||
514 | r = sd_event_default(&m->event); | |
515 | if (r < 0) | |
516 | return r; | |
517 | ||
518 | sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); | |
519 | sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); | |
520 | ||
521 | sd_event_set_watchdog(m->event, true); | |
522 | ||
523 | r = manager_watch_hostname(m); | |
524 | if (r < 0) | |
525 | return r; | |
526 | ||
527 | r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC); | |
528 | if (r < 0) | |
529 | return r; | |
530 | ||
531 | r = manager_network_monitor_listen(m); | |
532 | if (r < 0) | |
533 | return r; | |
534 | ||
535 | r = manager_rtnl_listen(m); | |
536 | if (r < 0) | |
537 | return r; | |
538 | ||
539 | r = manager_connect_bus(m); | |
540 | if (r < 0) | |
541 | return r; | |
542 | ||
543 | (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m); | |
544 | (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m); | |
545 | ||
546 | *ret = m; | |
547 | m = NULL; | |
548 | ||
549 | return 0; | |
550 | } | |
551 | ||
552 | int manager_start(Manager *m) { | |
553 | int r; | |
554 | ||
555 | assert(m); | |
556 | ||
557 | r = manager_llmnr_start(m); | |
558 | if (r < 0) | |
559 | return r; | |
560 | ||
561 | r = manager_mdns_start(m); | |
562 | if (r < 0) | |
563 | return r; | |
564 | ||
565 | return 0; | |
566 | } | |
567 | ||
568 | Manager *manager_free(Manager *m) { | |
569 | Link *l; | |
570 | ||
571 | if (!m) | |
572 | return NULL; | |
573 | ||
574 | dns_server_unlink_all(m->dns_servers); | |
575 | dns_server_unlink_all(m->fallback_dns_servers); | |
576 | dns_search_domain_unlink_all(m->search_domains); | |
577 | ||
578 | while ((l = hashmap_first(m->links))) | |
579 | link_free(l); | |
580 | ||
581 | while (m->dns_queries) | |
582 | dns_query_free(m->dns_queries); | |
583 | ||
584 | dns_scope_free(m->unicast_scope); | |
585 | ||
586 | hashmap_free(m->links); | |
587 | hashmap_free(m->dns_transactions); | |
588 | ||
589 | sd_event_source_unref(m->network_event_source); | |
590 | sd_network_monitor_unref(m->network_monitor); | |
591 | ||
592 | sd_netlink_unref(m->rtnl); | |
593 | sd_event_source_unref(m->rtnl_event_source); | |
594 | ||
595 | manager_llmnr_stop(m); | |
596 | manager_mdns_stop(m); | |
597 | ||
598 | sd_bus_slot_unref(m->prepare_for_sleep_slot); | |
599 | sd_event_source_unref(m->bus_retry_event_source); | |
600 | sd_bus_unref(m->bus); | |
601 | ||
602 | sd_event_source_unref(m->sigusr1_event_source); | |
603 | sd_event_source_unref(m->sigusr2_event_source); | |
604 | ||
605 | sd_event_unref(m->event); | |
606 | ||
607 | dns_resource_key_unref(m->llmnr_host_ipv4_key); | |
608 | dns_resource_key_unref(m->llmnr_host_ipv6_key); | |
609 | ||
610 | sd_event_source_unref(m->hostname_event_source); | |
611 | safe_close(m->hostname_fd); | |
612 | free(m->llmnr_hostname); | |
613 | free(m->mdns_hostname); | |
614 | ||
615 | dns_trust_anchor_flush(&m->trust_anchor); | |
616 | manager_etc_hosts_flush(m); | |
617 | ||
618 | free(m); | |
619 | ||
620 | return NULL; | |
621 | } | |
622 | ||
623 | int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { | |
624 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
625 | union { | |
626 | struct cmsghdr header; /* For alignment */ | |
627 | uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) | |
628 | + CMSG_SPACE(int) /* ttl/hoplimit */ | |
629 | + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */]; | |
630 | } control; | |
631 | union sockaddr_union sa; | |
632 | struct msghdr mh = {}; | |
633 | struct cmsghdr *cmsg; | |
634 | struct iovec iov; | |
635 | ssize_t ms, l; | |
636 | int r; | |
637 | ||
638 | assert(m); | |
639 | assert(fd >= 0); | |
640 | assert(ret); | |
641 | ||
642 | ms = next_datagram_size_fd(fd); | |
643 | if (ms < 0) | |
644 | return ms; | |
645 | ||
646 | r = dns_packet_new(&p, protocol, ms); | |
647 | if (r < 0) | |
648 | return r; | |
649 | ||
650 | iov.iov_base = DNS_PACKET_DATA(p); | |
651 | iov.iov_len = p->allocated; | |
652 | ||
653 | mh.msg_name = &sa.sa; | |
654 | mh.msg_namelen = sizeof(sa); | |
655 | mh.msg_iov = &iov; | |
656 | mh.msg_iovlen = 1; | |
657 | mh.msg_control = &control; | |
658 | mh.msg_controllen = sizeof(control); | |
659 | ||
660 | l = recvmsg(fd, &mh, 0); | |
661 | if (l == 0) | |
662 | return 0; | |
663 | if (l < 0) { | |
664 | if (errno == EAGAIN || errno == EINTR) | |
665 | return 0; | |
666 | ||
667 | return -errno; | |
668 | } | |
669 | ||
670 | assert(!(mh.msg_flags & MSG_CTRUNC)); | |
671 | assert(!(mh.msg_flags & MSG_TRUNC)); | |
672 | ||
673 | p->size = (size_t) l; | |
674 | ||
675 | p->family = sa.sa.sa_family; | |
676 | p->ipproto = IPPROTO_UDP; | |
677 | if (p->family == AF_INET) { | |
678 | p->sender.in = sa.in.sin_addr; | |
679 | p->sender_port = be16toh(sa.in.sin_port); | |
680 | } else if (p->family == AF_INET6) { | |
681 | p->sender.in6 = sa.in6.sin6_addr; | |
682 | p->sender_port = be16toh(sa.in6.sin6_port); | |
683 | p->ifindex = sa.in6.sin6_scope_id; | |
684 | } else | |
685 | return -EAFNOSUPPORT; | |
686 | ||
687 | CMSG_FOREACH(cmsg, &mh) { | |
688 | ||
689 | if (cmsg->cmsg_level == IPPROTO_IPV6) { | |
690 | assert(p->family == AF_INET6); | |
691 | ||
692 | switch (cmsg->cmsg_type) { | |
693 | ||
694 | case IPV6_PKTINFO: { | |
695 | struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg); | |
696 | ||
697 | if (p->ifindex <= 0) | |
698 | p->ifindex = i->ipi6_ifindex; | |
699 | ||
700 | p->destination.in6 = i->ipi6_addr; | |
701 | break; | |
702 | } | |
703 | ||
704 | case IPV6_HOPLIMIT: | |
705 | p->ttl = *(int *) CMSG_DATA(cmsg); | |
706 | break; | |
707 | ||
708 | } | |
709 | } else if (cmsg->cmsg_level == IPPROTO_IP) { | |
710 | assert(p->family == AF_INET); | |
711 | ||
712 | switch (cmsg->cmsg_type) { | |
713 | ||
714 | case IP_PKTINFO: { | |
715 | struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg); | |
716 | ||
717 | if (p->ifindex <= 0) | |
718 | p->ifindex = i->ipi_ifindex; | |
719 | ||
720 | p->destination.in = i->ipi_addr; | |
721 | break; | |
722 | } | |
723 | ||
724 | case IP_TTL: | |
725 | p->ttl = *(int *) CMSG_DATA(cmsg); | |
726 | break; | |
727 | } | |
728 | } | |
729 | } | |
730 | ||
731 | /* The Linux kernel sets the interface index to the loopback | |
732 | * device if the packet came from the local host since it | |
733 | * avoids the routing table in such a case. Let's unset the | |
734 | * interface index in such a case. */ | |
735 | if (p->ifindex == LOOPBACK_IFINDEX) | |
736 | p->ifindex = 0; | |
737 | ||
738 | if (protocol != DNS_PROTOCOL_DNS) { | |
739 | /* If we don't know the interface index still, we look for the | |
740 | * first local interface with a matching address. Yuck! */ | |
741 | if (p->ifindex <= 0) | |
742 | p->ifindex = manager_find_ifindex(m, p->family, &p->destination); | |
743 | } | |
744 | ||
745 | *ret = p; | |
746 | p = NULL; | |
747 | ||
748 | return 1; | |
749 | } | |
750 | ||
751 | static int sendmsg_loop(int fd, struct msghdr *mh, int flags) { | |
752 | int r; | |
753 | ||
754 | assert(fd >= 0); | |
755 | assert(mh); | |
756 | ||
757 | for (;;) { | |
758 | if (sendmsg(fd, mh, flags) >= 0) | |
759 | return 0; | |
760 | ||
761 | if (errno == EINTR) | |
762 | continue; | |
763 | ||
764 | if (errno != EAGAIN) | |
765 | return -errno; | |
766 | ||
767 | r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC); | |
768 | if (r < 0) | |
769 | return r; | |
770 | if (r == 0) | |
771 | return -ETIMEDOUT; | |
772 | } | |
773 | } | |
774 | ||
775 | static int write_loop(int fd, void *message, size_t length) { | |
776 | int r; | |
777 | ||
778 | assert(fd >= 0); | |
779 | assert(message); | |
780 | ||
781 | for (;;) { | |
782 | if (write(fd, message, length) >= 0) | |
783 | return 0; | |
784 | ||
785 | if (errno == EINTR) | |
786 | continue; | |
787 | ||
788 | if (errno != EAGAIN) | |
789 | return -errno; | |
790 | ||
791 | r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC); | |
792 | if (r < 0) | |
793 | return r; | |
794 | if (r == 0) | |
795 | return -ETIMEDOUT; | |
796 | } | |
797 | } | |
798 | ||
799 | int manager_write(Manager *m, int fd, DnsPacket *p) { | |
800 | int r; | |
801 | ||
802 | log_debug("Sending %s packet with id %" PRIu16 ".", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p)); | |
803 | ||
804 | r = write_loop(fd, DNS_PACKET_DATA(p), p->size); | |
805 | if (r < 0) | |
806 | return r; | |
807 | ||
808 | return 0; | |
809 | } | |
810 | ||
811 | static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) { | |
812 | union sockaddr_union sa = { | |
813 | .in.sin_family = AF_INET, | |
814 | }; | |
815 | union { | |
816 | struct cmsghdr header; /* For alignment */ | |
817 | uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))]; | |
818 | } control; | |
819 | struct msghdr mh = {}; | |
820 | struct iovec iov; | |
821 | ||
822 | assert(m); | |
823 | assert(fd >= 0); | |
824 | assert(addr); | |
825 | assert(port > 0); | |
826 | assert(p); | |
827 | ||
828 | iov.iov_base = DNS_PACKET_DATA(p); | |
829 | iov.iov_len = p->size; | |
830 | ||
831 | sa.in.sin_addr = *addr; | |
832 | sa.in.sin_port = htobe16(port), | |
833 | ||
834 | mh.msg_iov = &iov; | |
835 | mh.msg_iovlen = 1; | |
836 | mh.msg_name = &sa.sa; | |
837 | mh.msg_namelen = sizeof(sa.in); | |
838 | ||
839 | if (ifindex > 0) { | |
840 | struct cmsghdr *cmsg; | |
841 | struct in_pktinfo *pi; | |
842 | ||
843 | zero(control); | |
844 | ||
845 | mh.msg_control = &control; | |
846 | mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)); | |
847 | ||
848 | cmsg = CMSG_FIRSTHDR(&mh); | |
849 | cmsg->cmsg_len = mh.msg_controllen; | |
850 | cmsg->cmsg_level = IPPROTO_IP; | |
851 | cmsg->cmsg_type = IP_PKTINFO; | |
852 | ||
853 | pi = (struct in_pktinfo*) CMSG_DATA(cmsg); | |
854 | pi->ipi_ifindex = ifindex; | |
855 | } | |
856 | ||
857 | return sendmsg_loop(fd, &mh, 0); | |
858 | } | |
859 | ||
860 | static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) { | |
861 | union sockaddr_union sa = { | |
862 | .in6.sin6_family = AF_INET6, | |
863 | }; | |
864 | union { | |
865 | struct cmsghdr header; /* For alignment */ | |
866 | uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
867 | } control; | |
868 | struct msghdr mh = {}; | |
869 | struct iovec iov; | |
870 | ||
871 | assert(m); | |
872 | assert(fd >= 0); | |
873 | assert(addr); | |
874 | assert(port > 0); | |
875 | assert(p); | |
876 | ||
877 | iov.iov_base = DNS_PACKET_DATA(p); | |
878 | iov.iov_len = p->size; | |
879 | ||
880 | sa.in6.sin6_addr = *addr; | |
881 | sa.in6.sin6_port = htobe16(port), | |
882 | sa.in6.sin6_scope_id = ifindex; | |
883 | ||
884 | mh.msg_iov = &iov; | |
885 | mh.msg_iovlen = 1; | |
886 | mh.msg_name = &sa.sa; | |
887 | mh.msg_namelen = sizeof(sa.in6); | |
888 | ||
889 | if (ifindex > 0) { | |
890 | struct cmsghdr *cmsg; | |
891 | struct in6_pktinfo *pi; | |
892 | ||
893 | zero(control); | |
894 | ||
895 | mh.msg_control = &control; | |
896 | mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo)); | |
897 | ||
898 | cmsg = CMSG_FIRSTHDR(&mh); | |
899 | cmsg->cmsg_len = mh.msg_controllen; | |
900 | cmsg->cmsg_level = IPPROTO_IPV6; | |
901 | cmsg->cmsg_type = IPV6_PKTINFO; | |
902 | ||
903 | pi = (struct in6_pktinfo*) CMSG_DATA(cmsg); | |
904 | pi->ipi6_ifindex = ifindex; | |
905 | } | |
906 | ||
907 | return sendmsg_loop(fd, &mh, 0); | |
908 | } | |
909 | ||
910 | int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) { | |
911 | assert(m); | |
912 | assert(fd >= 0); | |
913 | assert(addr); | |
914 | assert(port > 0); | |
915 | assert(p); | |
916 | ||
917 | 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)); | |
918 | ||
919 | if (family == AF_INET) | |
920 | return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p); | |
921 | if (family == AF_INET6) | |
922 | return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p); | |
923 | ||
924 | return -EAFNOSUPPORT; | |
925 | } | |
926 | ||
927 | uint32_t manager_find_mtu(Manager *m) { | |
928 | uint32_t mtu = 0; | |
929 | Link *l; | |
930 | Iterator i; | |
931 | ||
932 | /* If we don't know on which link a DNS packet would be | |
933 | * delivered, let's find the largest MTU that works on all | |
934 | * interfaces we know of */ | |
935 | ||
936 | HASHMAP_FOREACH(l, m->links, i) { | |
937 | if (l->mtu <= 0) | |
938 | continue; | |
939 | ||
940 | if (mtu <= 0 || l->mtu < mtu) | |
941 | mtu = l->mtu; | |
942 | } | |
943 | ||
944 | return mtu; | |
945 | } | |
946 | ||
947 | int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { | |
948 | LinkAddress *a; | |
949 | ||
950 | assert(m); | |
951 | ||
952 | a = manager_find_link_address(m, family, in_addr); | |
953 | if (a) | |
954 | return a->link->ifindex; | |
955 | ||
956 | return 0; | |
957 | } | |
958 | ||
959 | void manager_refresh_rrs(Manager *m) { | |
960 | Iterator i; | |
961 | Link *l; | |
962 | ||
963 | assert(m); | |
964 | ||
965 | m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key); | |
966 | m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key); | |
967 | ||
968 | HASHMAP_FOREACH(l, m->links, i) { | |
969 | link_add_rrs(l, true); | |
970 | link_add_rrs(l, false); | |
971 | } | |
972 | } | |
973 | ||
974 | int manager_next_hostname(Manager *m) { | |
975 | const char *p; | |
976 | uint64_t u, a; | |
977 | char *h, *k; | |
978 | int r; | |
979 | ||
980 | assert(m); | |
981 | ||
982 | p = strchr(m->llmnr_hostname, 0); | |
983 | assert(p); | |
984 | ||
985 | while (p > m->llmnr_hostname) { | |
986 | if (!strchr("0123456789", p[-1])) | |
987 | break; | |
988 | ||
989 | p--; | |
990 | } | |
991 | ||
992 | if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0) | |
993 | u = 1; | |
994 | ||
995 | /* Add a random number to the old value. This way we can avoid | |
996 | * that two hosts pick the same hostname, win on IPv4 and lose | |
997 | * on IPv6 (or vice versa), and pick the same hostname | |
998 | * replacement hostname, ad infinitum. We still want the | |
999 | * numbers to go up monotonically, hence we just add a random | |
1000 | * value 1..10 */ | |
1001 | ||
1002 | random_bytes(&a, sizeof(a)); | |
1003 | u += 1 + a % 10; | |
1004 | ||
1005 | if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0) | |
1006 | return -ENOMEM; | |
1007 | ||
1008 | r = dns_name_concat(h, "local", &k); | |
1009 | if (r < 0) { | |
1010 | free(h); | |
1011 | return r; | |
1012 | } | |
1013 | ||
1014 | log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h); | |
1015 | ||
1016 | free(m->llmnr_hostname); | |
1017 | m->llmnr_hostname = h; | |
1018 | ||
1019 | free(m->mdns_hostname); | |
1020 | m->mdns_hostname = k; | |
1021 | ||
1022 | manager_refresh_rrs(m); | |
1023 | ||
1024 | return 0; | |
1025 | } | |
1026 | ||
1027 | LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) { | |
1028 | Iterator i; | |
1029 | Link *l; | |
1030 | ||
1031 | assert(m); | |
1032 | ||
1033 | HASHMAP_FOREACH(l, m->links, i) { | |
1034 | LinkAddress *a; | |
1035 | ||
1036 | a = link_find_address(l, family, in_addr); | |
1037 | if (a) | |
1038 | return a; | |
1039 | } | |
1040 | ||
1041 | return NULL; | |
1042 | } | |
1043 | ||
1044 | bool manager_our_packet(Manager *m, DnsPacket *p) { | |
1045 | assert(m); | |
1046 | assert(p); | |
1047 | ||
1048 | return !!manager_find_link_address(m, p->family, &p->sender); | |
1049 | } | |
1050 | ||
1051 | DnsScope* manager_find_scope(Manager *m, DnsPacket *p) { | |
1052 | Link *l; | |
1053 | ||
1054 | assert(m); | |
1055 | assert(p); | |
1056 | ||
1057 | l = hashmap_get(m->links, INT_TO_PTR(p->ifindex)); | |
1058 | if (!l) | |
1059 | return NULL; | |
1060 | ||
1061 | switch (p->protocol) { | |
1062 | case DNS_PROTOCOL_LLMNR: | |
1063 | if (p->family == AF_INET) | |
1064 | return l->llmnr_ipv4_scope; | |
1065 | else if (p->family == AF_INET6) | |
1066 | return l->llmnr_ipv6_scope; | |
1067 | ||
1068 | break; | |
1069 | ||
1070 | case DNS_PROTOCOL_MDNS: | |
1071 | if (p->family == AF_INET) | |
1072 | return l->mdns_ipv4_scope; | |
1073 | else if (p->family == AF_INET6) | |
1074 | return l->mdns_ipv6_scope; | |
1075 | ||
1076 | break; | |
1077 | ||
1078 | default: | |
1079 | break; | |
1080 | } | |
1081 | ||
1082 | return NULL; | |
1083 | } | |
1084 | ||
1085 | void manager_verify_all(Manager *m) { | |
1086 | DnsScope *s; | |
1087 | ||
1088 | assert(m); | |
1089 | ||
1090 | LIST_FOREACH(scopes, s, m->dns_scopes) | |
1091 | dns_zone_verify_all(&s->zone); | |
1092 | } | |
1093 | ||
1094 | int manager_is_own_hostname(Manager *m, const char *name) { | |
1095 | int r; | |
1096 | ||
1097 | assert(m); | |
1098 | assert(name); | |
1099 | ||
1100 | if (m->llmnr_hostname) { | |
1101 | r = dns_name_equal(name, m->llmnr_hostname); | |
1102 | if (r != 0) | |
1103 | return r; | |
1104 | } | |
1105 | ||
1106 | if (m->mdns_hostname) | |
1107 | return dns_name_equal(name, m->mdns_hostname); | |
1108 | ||
1109 | return 0; | |
1110 | } | |
1111 | ||
1112 | int manager_compile_dns_servers(Manager *m, OrderedSet **dns) { | |
1113 | DnsServer *s; | |
1114 | Iterator i; | |
1115 | Link *l; | |
1116 | int r; | |
1117 | ||
1118 | assert(m); | |
1119 | assert(dns); | |
1120 | ||
1121 | r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops); | |
1122 | if (r < 0) | |
1123 | return r; | |
1124 | ||
1125 | /* First add the system-wide servers and domains */ | |
1126 | LIST_FOREACH(servers, s, m->dns_servers) { | |
1127 | r = ordered_set_put(*dns, s); | |
1128 | if (r == -EEXIST) | |
1129 | continue; | |
1130 | if (r < 0) | |
1131 | return r; | |
1132 | } | |
1133 | ||
1134 | /* Then, add the per-link servers */ | |
1135 | HASHMAP_FOREACH(l, m->links, i) { | |
1136 | LIST_FOREACH(servers, s, l->dns_servers) { | |
1137 | r = ordered_set_put(*dns, s); | |
1138 | if (r == -EEXIST) | |
1139 | continue; | |
1140 | if (r < 0) | |
1141 | return r; | |
1142 | } | |
1143 | } | |
1144 | ||
1145 | /* If we found nothing, add the fallback servers */ | |
1146 | if (ordered_set_isempty(*dns)) { | |
1147 | LIST_FOREACH(servers, s, m->fallback_dns_servers) { | |
1148 | r = ordered_set_put(*dns, s); | |
1149 | if (r == -EEXIST) | |
1150 | continue; | |
1151 | if (r < 0) | |
1152 | return r; | |
1153 | } | |
1154 | } | |
1155 | ||
1156 | return 0; | |
1157 | } | |
1158 | ||
1159 | int manager_compile_search_domains(Manager *m, OrderedSet **domains) { | |
1160 | DnsSearchDomain *d; | |
1161 | Iterator i; | |
1162 | Link *l; | |
1163 | int r; | |
1164 | ||
1165 | assert(m); | |
1166 | assert(domains); | |
1167 | ||
1168 | r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops); | |
1169 | if (r < 0) | |
1170 | return r; | |
1171 | ||
1172 | LIST_FOREACH(domains, d, m->search_domains) { | |
1173 | r = ordered_set_put(*domains, d->name); | |
1174 | if (r == -EEXIST) | |
1175 | continue; | |
1176 | if (r < 0) | |
1177 | return r; | |
1178 | } | |
1179 | ||
1180 | HASHMAP_FOREACH(l, m->links, i) { | |
1181 | ||
1182 | LIST_FOREACH(domains, d, l->search_domains) { | |
1183 | r = ordered_set_put(*domains, d->name); | |
1184 | if (r == -EEXIST) | |
1185 | continue; | |
1186 | if (r < 0) | |
1187 | return r; | |
1188 | } | |
1189 | } | |
1190 | ||
1191 | return 0; | |
1192 | } | |
1193 | ||
1194 | DnssecMode manager_get_dnssec_mode(Manager *m) { | |
1195 | assert(m); | |
1196 | ||
1197 | if (m->dnssec_mode != _DNSSEC_MODE_INVALID) | |
1198 | return m->dnssec_mode; | |
1199 | ||
1200 | return DNSSEC_NO; | |
1201 | } | |
1202 | ||
1203 | bool manager_dnssec_supported(Manager *m) { | |
1204 | DnsServer *server; | |
1205 | Iterator i; | |
1206 | Link *l; | |
1207 | ||
1208 | assert(m); | |
1209 | ||
1210 | if (manager_get_dnssec_mode(m) == DNSSEC_NO) | |
1211 | return false; | |
1212 | ||
1213 | server = manager_get_dns_server(m); | |
1214 | if (server && !dns_server_dnssec_supported(server)) | |
1215 | return false; | |
1216 | ||
1217 | HASHMAP_FOREACH(l, m->links, i) | |
1218 | if (!link_dnssec_supported(l)) | |
1219 | return false; | |
1220 | ||
1221 | return true; | |
1222 | } | |
1223 | ||
1224 | void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) { | |
1225 | ||
1226 | assert(verdict >= 0); | |
1227 | assert(verdict < _DNSSEC_VERDICT_MAX); | |
1228 | ||
1229 | if (log_get_max_level() >= LOG_DEBUG) { | |
1230 | char s[DNS_RESOURCE_KEY_STRING_MAX]; | |
1231 | ||
1232 | log_debug("Found verdict for lookup %s: %s", | |
1233 | dns_resource_key_to_string(key, s, sizeof s), | |
1234 | dnssec_verdict_to_string(verdict)); | |
1235 | } | |
1236 | ||
1237 | m->n_dnssec_verdict[verdict]++; | |
1238 | } | |
1239 | ||
1240 | bool manager_routable(Manager *m, int family) { | |
1241 | Iterator i; | |
1242 | Link *l; | |
1243 | ||
1244 | assert(m); | |
1245 | ||
1246 | /* Returns true if the host has at least one interface with a routable address of the specified type */ | |
1247 | ||
1248 | HASHMAP_FOREACH(l, m->links, i) | |
1249 | if (link_relevant(l, family, false)) | |
1250 | return true; | |
1251 | ||
1252 | return false; | |
1253 | } |