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