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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 "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_netlink_message_unref_ 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, 0); | |
208 | if (r < 0) | |
209 | return r; | |
210 | ||
211 | r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m); | |
212 | if (r < 0) | |
213 | return r; | |
214 | ||
215 | r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m); | |
216 | if (r < 0) | |
217 | return r; | |
218 | ||
219 | r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m); | |
220 | if (r < 0) | |
221 | return r; | |
222 | ||
223 | r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m); | |
224 | if (r < 0) | |
225 | return r; | |
226 | ||
227 | /* Then, enumerate all links */ | |
228 | r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0); | |
229 | if (r < 0) | |
230 | return r; | |
231 | ||
232 | r = sd_netlink_message_request_dump(req, true); | |
233 | if (r < 0) | |
234 | return r; | |
235 | ||
236 | r = sd_netlink_call(m->rtnl, req, 0, &reply); | |
237 | if (r < 0) | |
238 | return r; | |
239 | ||
240 | for (i = reply; i; i = sd_netlink_message_next(i)) { | |
241 | r = manager_process_link(m->rtnl, i, m); | |
242 | if (r < 0) | |
243 | return r; | |
244 | } | |
245 | ||
246 | req = sd_netlink_message_unref(req); | |
247 | reply = sd_netlink_message_unref(reply); | |
248 | ||
249 | /* Finally, enumerate all addresses, too */ | |
250 | r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC); | |
251 | if (r < 0) | |
252 | return r; | |
253 | ||
254 | r = sd_netlink_message_request_dump(req, true); | |
255 | if (r < 0) | |
256 | return r; | |
257 | ||
258 | r = sd_netlink_call(m->rtnl, req, 0, &reply); | |
259 | if (r < 0) | |
260 | return r; | |
261 | ||
262 | for (i = reply; i; i = sd_netlink_message_next(i)) { | |
263 | r = manager_process_address(m->rtnl, i, m); | |
264 | if (r < 0) | |
265 | return r; | |
266 | } | |
267 | ||
268 | return r; | |
269 | } | |
270 | ||
271 | static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
272 | Manager *m = userdata; | |
273 | Iterator i; | |
274 | Link *l; | |
275 | int r; | |
276 | ||
277 | assert(m); | |
278 | ||
279 | sd_network_monitor_flush(m->network_monitor); | |
280 | ||
281 | HASHMAP_FOREACH(l, m->links, i) { | |
282 | r = link_update_monitor(l); | |
283 | if (r < 0) | |
284 | log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex); | |
285 | } | |
286 | ||
287 | r = manager_write_resolv_conf(m); | |
288 | if (r < 0) | |
289 | log_warning_errno(r, "Could not update resolv.conf: %m"); | |
290 | ||
291 | return 0; | |
292 | } | |
293 | ||
294 | static int manager_network_monitor_listen(Manager *m) { | |
295 | int r, fd, events; | |
296 | ||
297 | assert(m); | |
298 | ||
299 | r = sd_network_monitor_new(&m->network_monitor, NULL); | |
300 | if (r < 0) | |
301 | return r; | |
302 | ||
303 | fd = sd_network_monitor_get_fd(m->network_monitor); | |
304 | if (fd < 0) | |
305 | return fd; | |
306 | ||
307 | events = sd_network_monitor_get_events(m->network_monitor); | |
308 | if (events < 0) | |
309 | return events; | |
310 | ||
311 | r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m); | |
312 | if (r < 0) | |
313 | return r; | |
314 | ||
315 | return 0; | |
316 | } | |
317 | ||
318 | static int determine_hostname(char **llmnr_hostname, char **mdns_hostname) { | |
319 | _cleanup_free_ char *h = NULL, *n = NULL; | |
320 | char label[DNS_LABEL_MAX]; | |
321 | const char *p; | |
322 | int r, k; | |
323 | ||
324 | assert(llmnr_hostname); | |
325 | assert(mdns_hostname); | |
326 | ||
327 | /* Extract and normalize the first label of the locally | |
328 | * configured hostname, and check it's not "localhost". */ | |
329 | ||
330 | h = gethostname_malloc(); | |
331 | if (!h) | |
332 | return log_oom(); | |
333 | ||
334 | p = h; | |
335 | r = dns_label_unescape(&p, label, sizeof(label)); | |
336 | if (r < 0) | |
337 | return log_error_errno(r, "Failed to unescape host name: %m"); | |
338 | if (r == 0) { | |
339 | log_error("Couldn't find a single label in hosntame."); | |
340 | return -EINVAL; | |
341 | } | |
342 | ||
343 | k = dns_label_undo_idna(label, r, label, sizeof(label)); | |
344 | if (k < 0) | |
345 | return log_error_errno(k, "Failed to undo IDNA: %m"); | |
346 | if (k > 0) | |
347 | r = k; | |
348 | ||
349 | if (!utf8_is_valid(label)) { | |
350 | log_error("System hostname is not UTF-8 clean."); | |
351 | return -EINVAL; | |
352 | } | |
353 | ||
354 | r = dns_label_escape(label, r, &n); | |
355 | if (r < 0) | |
356 | return log_error_errno(r, "Failed to escape host name: %m"); | |
357 | ||
358 | if (is_localhost(n)) { | |
359 | log_debug("System hostname is 'localhost', ignoring."); | |
360 | return -EINVAL; | |
361 | } | |
362 | ||
363 | r = dns_name_concat(n, "local", mdns_hostname); | |
364 | if (r < 0) | |
365 | return log_error_errno(r, "Failed to determine mDNS hostname: %m"); | |
366 | ||
367 | *llmnr_hostname = n; | |
368 | n = NULL; | |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
373 | static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) { | |
374 | _cleanup_free_ char *llmnr_hostname = NULL, *mdns_hostname = NULL; | |
375 | Manager *m = userdata; | |
376 | int r; | |
377 | ||
378 | assert(m); | |
379 | ||
380 | r = determine_hostname(&llmnr_hostname, &mdns_hostname); | |
381 | if (r < 0) | |
382 | return 0; /* ignore invalid hostnames */ | |
383 | ||
384 | if (streq(llmnr_hostname, m->llmnr_hostname) && streq(mdns_hostname, m->mdns_hostname)) | |
385 | return 0; | |
386 | ||
387 | log_info("System hostname changed to '%s'.", llmnr_hostname); | |
388 | ||
389 | free(m->llmnr_hostname); | |
390 | free(m->mdns_hostname); | |
391 | ||
392 | m->llmnr_hostname = llmnr_hostname; | |
393 | m->mdns_hostname = mdns_hostname; | |
394 | ||
395 | llmnr_hostname = mdns_hostname = NULL; | |
396 | ||
397 | manager_refresh_rrs(m); | |
398 | ||
399 | return 0; | |
400 | } | |
401 | ||
402 | static int manager_watch_hostname(Manager *m) { | |
403 | int r; | |
404 | ||
405 | assert(m); | |
406 | ||
407 | m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY); | |
408 | if (m->hostname_fd < 0) { | |
409 | log_warning_errno(errno, "Failed to watch hostname: %m"); | |
410 | return 0; | |
411 | } | |
412 | ||
413 | r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m); | |
414 | if (r < 0) { | |
415 | if (r == -EPERM) | |
416 | /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */ | |
417 | m->hostname_fd = safe_close(m->hostname_fd); | |
418 | else | |
419 | return log_error_errno(r, "Failed to add hostname event source: %m"); | |
420 | } | |
421 | ||
422 | r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname); | |
423 | if (r < 0) { | |
424 | log_info("Defaulting to hostname 'linux'."); | |
425 | m->llmnr_hostname = strdup("linux"); | |
426 | if (!m->llmnr_hostname) | |
427 | return log_oom(); | |
428 | ||
429 | m->mdns_hostname = strdup("linux.local"); | |
430 | if (!m->mdns_hostname) | |
431 | return log_oom(); | |
432 | } else | |
433 | log_info("Using system hostname '%s'.", m->llmnr_hostname); | |
434 | ||
435 | return 0; | |
436 | } | |
437 | ||
438 | static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { | |
439 | _cleanup_free_ char *buffer = NULL; | |
440 | _cleanup_fclose_ FILE *f = NULL; | |
441 | Manager *m = userdata; | |
442 | size_t size = 0; | |
443 | DnsScope *scope; | |
444 | ||
445 | assert(s); | |
446 | assert(si); | |
447 | assert(m); | |
448 | ||
449 | f = open_memstream(&buffer, &size); | |
450 | if (!f) | |
451 | return log_oom(); | |
452 | ||
453 | LIST_FOREACH(scopes, scope, m->dns_scopes) | |
454 | dns_scope_dump(scope, f); | |
455 | ||
456 | if (fflush_and_check(f) < 0) | |
457 | return log_oom(); | |
458 | ||
459 | log_dump(LOG_INFO, buffer); | |
460 | return 0; | |
461 | } | |
462 | ||
463 | int manager_new(Manager **ret) { | |
464 | _cleanup_(manager_freep) Manager *m = NULL; | |
465 | int r; | |
466 | ||
467 | assert(ret); | |
468 | ||
469 | m = new0(Manager, 1); | |
470 | if (!m) | |
471 | return -ENOMEM; | |
472 | ||
473 | m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; | |
474 | m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; | |
475 | m->hostname_fd = -1; | |
476 | ||
477 | m->llmnr_support = SUPPORT_YES; | |
478 | m->read_resolv_conf = true; | |
479 | m->need_builtin_fallbacks = true; | |
480 | ||
481 | r = sd_event_default(&m->event); | |
482 | if (r < 0) | |
483 | return r; | |
484 | ||
485 | sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); | |
486 | sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); | |
487 | ||
488 | sd_event_set_watchdog(m->event, true); | |
489 | ||
490 | r = manager_watch_hostname(m); | |
491 | if (r < 0) | |
492 | return r; | |
493 | ||
494 | r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC); | |
495 | if (r < 0) | |
496 | return r; | |
497 | ||
498 | r = manager_network_monitor_listen(m); | |
499 | if (r < 0) | |
500 | return r; | |
501 | ||
502 | r = manager_rtnl_listen(m); | |
503 | if (r < 0) | |
504 | return r; | |
505 | ||
506 | r = manager_connect_bus(m); | |
507 | if (r < 0) | |
508 | return r; | |
509 | ||
510 | (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m); | |
511 | ||
512 | *ret = m; | |
513 | m = NULL; | |
514 | ||
515 | return 0; | |
516 | } | |
517 | ||
518 | int manager_start(Manager *m) { | |
519 | int r; | |
520 | ||
521 | assert(m); | |
522 | ||
523 | r = manager_llmnr_start(m); | |
524 | if (r < 0) | |
525 | return r; | |
526 | ||
527 | return 0; | |
528 | } | |
529 | ||
530 | Manager *manager_free(Manager *m) { | |
531 | Link *l; | |
532 | ||
533 | if (!m) | |
534 | return NULL; | |
535 | ||
536 | manager_flush_dns_servers(m, DNS_SERVER_SYSTEM); | |
537 | manager_flush_dns_servers(m, DNS_SERVER_FALLBACK); | |
538 | ||
539 | dns_search_domain_unlink_all(m->search_domains); | |
540 | ||
541 | while ((l = hashmap_first(m->links))) | |
542 | link_free(l); | |
543 | ||
544 | while (m->dns_queries) | |
545 | dns_query_free(m->dns_queries); | |
546 | ||
547 | dns_scope_free(m->unicast_scope); | |
548 | ||
549 | hashmap_free(m->links); | |
550 | hashmap_free(m->dns_transactions); | |
551 | ||
552 | sd_event_source_unref(m->network_event_source); | |
553 | sd_network_monitor_unref(m->network_monitor); | |
554 | ||
555 | sd_netlink_unref(m->rtnl); | |
556 | sd_event_source_unref(m->rtnl_event_source); | |
557 | ||
558 | manager_llmnr_stop(m); | |
559 | ||
560 | sd_bus_slot_unref(m->prepare_for_sleep_slot); | |
561 | sd_event_source_unref(m->bus_retry_event_source); | |
562 | sd_bus_unref(m->bus); | |
563 | ||
564 | sd_event_source_unref(m->sigusr1_event_source); | |
565 | ||
566 | sd_event_unref(m->event); | |
567 | ||
568 | dns_resource_key_unref(m->llmnr_host_ipv4_key); | |
569 | dns_resource_key_unref(m->llmnr_host_ipv6_key); | |
570 | ||
571 | sd_event_source_unref(m->hostname_event_source); | |
572 | safe_close(m->hostname_fd); | |
573 | free(m->llmnr_hostname); | |
574 | free(m->mdns_hostname); | |
575 | ||
576 | free(m); | |
577 | ||
578 | return NULL; | |
579 | } | |
580 | ||
581 | int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { | |
582 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
583 | union { | |
584 | struct cmsghdr header; /* For alignment */ | |
585 | uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo)) | |
586 | + CMSG_SPACE(int) /* ttl/hoplimit */ | |
587 | + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */]; | |
588 | } control; | |
589 | union sockaddr_union sa; | |
590 | struct msghdr mh = {}; | |
591 | struct cmsghdr *cmsg; | |
592 | struct iovec iov; | |
593 | int ms = 0, r; | |
594 | ssize_t l; | |
595 | ||
596 | assert(m); | |
597 | assert(fd >= 0); | |
598 | assert(ret); | |
599 | ||
600 | r = ioctl(fd, FIONREAD, &ms); | |
601 | if (r < 0) | |
602 | return -errno; | |
603 | if (ms < 0) | |
604 | return -EIO; | |
605 | ||
606 | r = dns_packet_new(&p, protocol, ms); | |
607 | if (r < 0) | |
608 | return r; | |
609 | ||
610 | iov.iov_base = DNS_PACKET_DATA(p); | |
611 | iov.iov_len = p->allocated; | |
612 | ||
613 | mh.msg_name = &sa.sa; | |
614 | mh.msg_namelen = sizeof(sa); | |
615 | mh.msg_iov = &iov; | |
616 | mh.msg_iovlen = 1; | |
617 | mh.msg_control = &control; | |
618 | mh.msg_controllen = sizeof(control); | |
619 | ||
620 | l = recvmsg(fd, &mh, 0); | |
621 | if (l < 0) { | |
622 | if (errno == EAGAIN || errno == EINTR) | |
623 | return 0; | |
624 | ||
625 | return -errno; | |
626 | } | |
627 | ||
628 | if (l <= 0) | |
629 | return -EIO; | |
630 | ||
631 | assert(!(mh.msg_flags & MSG_CTRUNC)); | |
632 | assert(!(mh.msg_flags & MSG_TRUNC)); | |
633 | ||
634 | p->size = (size_t) l; | |
635 | ||
636 | p->family = sa.sa.sa_family; | |
637 | p->ipproto = IPPROTO_UDP; | |
638 | if (p->family == AF_INET) { | |
639 | p->sender.in = sa.in.sin_addr; | |
640 | p->sender_port = be16toh(sa.in.sin_port); | |
641 | } else if (p->family == AF_INET6) { | |
642 | p->sender.in6 = sa.in6.sin6_addr; | |
643 | p->sender_port = be16toh(sa.in6.sin6_port); | |
644 | p->ifindex = sa.in6.sin6_scope_id; | |
645 | } else | |
646 | return -EAFNOSUPPORT; | |
647 | ||
648 | CMSG_FOREACH(cmsg, &mh) { | |
649 | ||
650 | if (cmsg->cmsg_level == IPPROTO_IPV6) { | |
651 | assert(p->family == AF_INET6); | |
652 | ||
653 | switch (cmsg->cmsg_type) { | |
654 | ||
655 | case IPV6_PKTINFO: { | |
656 | struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg); | |
657 | ||
658 | if (p->ifindex <= 0) | |
659 | p->ifindex = i->ipi6_ifindex; | |
660 | ||
661 | p->destination.in6 = i->ipi6_addr; | |
662 | break; | |
663 | } | |
664 | ||
665 | case IPV6_HOPLIMIT: | |
666 | p->ttl = *(int *) CMSG_DATA(cmsg); | |
667 | break; | |
668 | ||
669 | } | |
670 | } else if (cmsg->cmsg_level == IPPROTO_IP) { | |
671 | assert(p->family == AF_INET); | |
672 | ||
673 | switch (cmsg->cmsg_type) { | |
674 | ||
675 | case IP_PKTINFO: { | |
676 | struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg); | |
677 | ||
678 | if (p->ifindex <= 0) | |
679 | p->ifindex = i->ipi_ifindex; | |
680 | ||
681 | p->destination.in = i->ipi_addr; | |
682 | break; | |
683 | } | |
684 | ||
685 | case IP_TTL: | |
686 | p->ttl = *(int *) CMSG_DATA(cmsg); | |
687 | break; | |
688 | } | |
689 | } | |
690 | } | |
691 | ||
692 | /* The Linux kernel sets the interface index to the loopback | |
693 | * device if the packet came from the local host since it | |
694 | * avoids the routing table in such a case. Let's unset the | |
695 | * interface index in such a case. */ | |
696 | if (p->ifindex == LOOPBACK_IFINDEX) | |
697 | p->ifindex = 0; | |
698 | ||
699 | if (protocol != DNS_PROTOCOL_DNS) { | |
700 | /* If we don't know the interface index still, we look for the | |
701 | * first local interface with a matching address. Yuck! */ | |
702 | if (p->ifindex <= 0) | |
703 | p->ifindex = manager_find_ifindex(m, p->family, &p->destination); | |
704 | } | |
705 | ||
706 | *ret = p; | |
707 | p = NULL; | |
708 | ||
709 | return 1; | |
710 | } | |
711 | ||
712 | static int sendmsg_loop(int fd, struct msghdr *mh, int flags) { | |
713 | int r; | |
714 | ||
715 | assert(fd >= 0); | |
716 | assert(mh); | |
717 | ||
718 | for (;;) { | |
719 | if (sendmsg(fd, mh, flags) >= 0) | |
720 | return 0; | |
721 | ||
722 | if (errno == EINTR) | |
723 | continue; | |
724 | ||
725 | if (errno != EAGAIN) | |
726 | return -errno; | |
727 | ||
728 | r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC); | |
729 | if (r < 0) | |
730 | return r; | |
731 | if (r == 0) | |
732 | return -ETIMEDOUT; | |
733 | } | |
734 | } | |
735 | ||
736 | static int write_loop(int fd, void *message, size_t length) { | |
737 | int r; | |
738 | ||
739 | assert(fd >= 0); | |
740 | assert(message); | |
741 | ||
742 | for (;;) { | |
743 | if (write(fd, message, length) >= 0) | |
744 | return 0; | |
745 | ||
746 | if (errno == EINTR) | |
747 | continue; | |
748 | ||
749 | if (errno != EAGAIN) | |
750 | return -errno; | |
751 | ||
752 | r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC); | |
753 | if (r < 0) | |
754 | return r; | |
755 | if (r == 0) | |
756 | return -ETIMEDOUT; | |
757 | } | |
758 | } | |
759 | ||
760 | int manager_write(Manager *m, int fd, DnsPacket *p) { | |
761 | int r; | |
762 | ||
763 | log_debug("Sending %s packet with id %u", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p)); | |
764 | ||
765 | r = write_loop(fd, DNS_PACKET_DATA(p), p->size); | |
766 | if (r < 0) | |
767 | return r; | |
768 | ||
769 | return 0; | |
770 | } | |
771 | ||
772 | static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) { | |
773 | union sockaddr_union sa = { | |
774 | .in.sin_family = AF_INET, | |
775 | }; | |
776 | union { | |
777 | struct cmsghdr header; /* For alignment */ | |
778 | uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))]; | |
779 | } control; | |
780 | struct msghdr mh = {}; | |
781 | struct iovec iov; | |
782 | ||
783 | assert(m); | |
784 | assert(fd >= 0); | |
785 | assert(addr); | |
786 | assert(port > 0); | |
787 | assert(p); | |
788 | ||
789 | iov.iov_base = DNS_PACKET_DATA(p); | |
790 | iov.iov_len = p->size; | |
791 | ||
792 | sa.in.sin_addr = *addr; | |
793 | sa.in.sin_port = htobe16(port), | |
794 | ||
795 | mh.msg_iov = &iov; | |
796 | mh.msg_iovlen = 1; | |
797 | mh.msg_name = &sa.sa; | |
798 | mh.msg_namelen = sizeof(sa.in); | |
799 | ||
800 | if (ifindex > 0) { | |
801 | struct cmsghdr *cmsg; | |
802 | struct in_pktinfo *pi; | |
803 | ||
804 | zero(control); | |
805 | ||
806 | mh.msg_control = &control; | |
807 | mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)); | |
808 | ||
809 | cmsg = CMSG_FIRSTHDR(&mh); | |
810 | cmsg->cmsg_len = mh.msg_controllen; | |
811 | cmsg->cmsg_level = IPPROTO_IP; | |
812 | cmsg->cmsg_type = IP_PKTINFO; | |
813 | ||
814 | pi = (struct in_pktinfo*) CMSG_DATA(cmsg); | |
815 | pi->ipi_ifindex = ifindex; | |
816 | } | |
817 | ||
818 | return sendmsg_loop(fd, &mh, 0); | |
819 | } | |
820 | ||
821 | static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) { | |
822 | union sockaddr_union sa = { | |
823 | .in6.sin6_family = AF_INET6, | |
824 | }; | |
825 | union { | |
826 | struct cmsghdr header; /* For alignment */ | |
827 | uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
828 | } control; | |
829 | struct msghdr mh = {}; | |
830 | struct iovec iov; | |
831 | ||
832 | assert(m); | |
833 | assert(fd >= 0); | |
834 | assert(addr); | |
835 | assert(port > 0); | |
836 | assert(p); | |
837 | ||
838 | iov.iov_base = DNS_PACKET_DATA(p); | |
839 | iov.iov_len = p->size; | |
840 | ||
841 | sa.in6.sin6_addr = *addr; | |
842 | sa.in6.sin6_port = htobe16(port), | |
843 | sa.in6.sin6_scope_id = ifindex; | |
844 | ||
845 | mh.msg_iov = &iov; | |
846 | mh.msg_iovlen = 1; | |
847 | mh.msg_name = &sa.sa; | |
848 | mh.msg_namelen = sizeof(sa.in6); | |
849 | ||
850 | if (ifindex > 0) { | |
851 | struct cmsghdr *cmsg; | |
852 | struct in6_pktinfo *pi; | |
853 | ||
854 | zero(control); | |
855 | ||
856 | mh.msg_control = &control; | |
857 | mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo)); | |
858 | ||
859 | cmsg = CMSG_FIRSTHDR(&mh); | |
860 | cmsg->cmsg_len = mh.msg_controllen; | |
861 | cmsg->cmsg_level = IPPROTO_IPV6; | |
862 | cmsg->cmsg_type = IPV6_PKTINFO; | |
863 | ||
864 | pi = (struct in6_pktinfo*) CMSG_DATA(cmsg); | |
865 | pi->ipi6_ifindex = ifindex; | |
866 | } | |
867 | ||
868 | return sendmsg_loop(fd, &mh, 0); | |
869 | } | |
870 | ||
871 | int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) { | |
872 | assert(m); | |
873 | assert(fd >= 0); | |
874 | assert(addr); | |
875 | assert(port > 0); | |
876 | assert(p); | |
877 | ||
878 | log_debug("Sending %s packet with id %u on interface %i/%s", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family)); | |
879 | ||
880 | if (family == AF_INET) | |
881 | return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p); | |
882 | else if (family == AF_INET6) | |
883 | return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p); | |
884 | ||
885 | return -EAFNOSUPPORT; | |
886 | } | |
887 | ||
888 | uint32_t manager_find_mtu(Manager *m) { | |
889 | uint32_t mtu = 0; | |
890 | Link *l; | |
891 | Iterator i; | |
892 | ||
893 | /* If we don't know on which link a DNS packet would be | |
894 | * delivered, let's find the largest MTU that works on all | |
895 | * interfaces we know of */ | |
896 | ||
897 | HASHMAP_FOREACH(l, m->links, i) { | |
898 | if (l->mtu <= 0) | |
899 | continue; | |
900 | ||
901 | if (mtu <= 0 || l->mtu < mtu) | |
902 | mtu = l->mtu; | |
903 | } | |
904 | ||
905 | return mtu; | |
906 | } | |
907 | ||
908 | int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) { | |
909 | LinkAddress *a; | |
910 | ||
911 | assert(m); | |
912 | ||
913 | a = manager_find_link_address(m, family, in_addr); | |
914 | if (a) | |
915 | return a->link->ifindex; | |
916 | ||
917 | return 0; | |
918 | } | |
919 | ||
920 | void manager_refresh_rrs(Manager *m) { | |
921 | Iterator i; | |
922 | Link *l; | |
923 | ||
924 | assert(m); | |
925 | ||
926 | m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key); | |
927 | m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key); | |
928 | ||
929 | HASHMAP_FOREACH(l, m->links, i) { | |
930 | link_add_rrs(l, true); | |
931 | link_add_rrs(l, false); | |
932 | } | |
933 | } | |
934 | ||
935 | int manager_next_hostname(Manager *m) { | |
936 | const char *p; | |
937 | uint64_t u, a; | |
938 | char *h, *k; | |
939 | int r; | |
940 | ||
941 | assert(m); | |
942 | ||
943 | p = strchr(m->llmnr_hostname, 0); | |
944 | assert(p); | |
945 | ||
946 | while (p > m->llmnr_hostname) { | |
947 | if (!strchr("0123456789", p[-1])) | |
948 | break; | |
949 | ||
950 | p--; | |
951 | } | |
952 | ||
953 | if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0) | |
954 | u = 1; | |
955 | ||
956 | /* Add a random number to the old value. This way we can avoid | |
957 | * that two hosts pick the same hostname, win on IPv4 and lose | |
958 | * on IPv6 (or vice versa), and pick the same hostname | |
959 | * replacement hostname, ad infinitum. We still want the | |
960 | * numbers to go up monotonically, hence we just add a random | |
961 | * value 1..10 */ | |
962 | ||
963 | random_bytes(&a, sizeof(a)); | |
964 | u += 1 + a % 10; | |
965 | ||
966 | if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0) | |
967 | return -ENOMEM; | |
968 | ||
969 | r = dns_name_concat(h, "local", &k); | |
970 | if (r < 0) { | |
971 | free(h); | |
972 | return r; | |
973 | } | |
974 | ||
975 | log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h); | |
976 | ||
977 | free(m->llmnr_hostname); | |
978 | m->llmnr_hostname = h; | |
979 | ||
980 | free(m->mdns_hostname); | |
981 | m->mdns_hostname = k; | |
982 | ||
983 | manager_refresh_rrs(m); | |
984 | ||
985 | return 0; | |
986 | } | |
987 | ||
988 | LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) { | |
989 | Iterator i; | |
990 | Link *l; | |
991 | ||
992 | assert(m); | |
993 | ||
994 | HASHMAP_FOREACH(l, m->links, i) { | |
995 | LinkAddress *a; | |
996 | ||
997 | a = link_find_address(l, family, in_addr); | |
998 | if (a) | |
999 | return a; | |
1000 | } | |
1001 | ||
1002 | return NULL; | |
1003 | } | |
1004 | ||
1005 | bool manager_our_packet(Manager *m, DnsPacket *p) { | |
1006 | assert(m); | |
1007 | assert(p); | |
1008 | ||
1009 | return !!manager_find_link_address(m, p->family, &p->sender); | |
1010 | } | |
1011 | ||
1012 | DnsScope* manager_find_scope(Manager *m, DnsPacket *p) { | |
1013 | Link *l; | |
1014 | ||
1015 | assert(m); | |
1016 | assert(p); | |
1017 | ||
1018 | l = hashmap_get(m->links, INT_TO_PTR(p->ifindex)); | |
1019 | if (!l) | |
1020 | return NULL; | |
1021 | ||
1022 | if (p->protocol == DNS_PROTOCOL_LLMNR) { | |
1023 | if (p->family == AF_INET) | |
1024 | return l->llmnr_ipv4_scope; | |
1025 | else if (p->family == AF_INET6) | |
1026 | return l->llmnr_ipv6_scope; | |
1027 | } | |
1028 | ||
1029 | return NULL; | |
1030 | } | |
1031 | ||
1032 | void manager_verify_all(Manager *m) { | |
1033 | DnsScope *s; | |
1034 | ||
1035 | assert(m); | |
1036 | ||
1037 | LIST_FOREACH(scopes, s, m->dns_scopes) | |
1038 | dns_zone_verify_all(&s->zone); | |
1039 | } | |
1040 | ||
1041 | int manager_is_own_hostname(Manager *m, const char *name) { | |
1042 | int r; | |
1043 | ||
1044 | assert(m); | |
1045 | assert(name); | |
1046 | ||
1047 | if (m->llmnr_hostname) { | |
1048 | r = dns_name_equal(name, m->llmnr_hostname); | |
1049 | if (r != 0) | |
1050 | return r; | |
1051 | } | |
1052 | ||
1053 | if (m->mdns_hostname) | |
1054 | return dns_name_equal(name, m->mdns_hostname); | |
1055 | ||
1056 | return 0; | |
1057 | } | |
1058 | ||
1059 | static const char* const support_table[_SUPPORT_MAX] = { | |
1060 | [SUPPORT_NO] = "no", | |
1061 | [SUPPORT_YES] = "yes", | |
1062 | [SUPPORT_RESOLVE] = "resolve", | |
1063 | }; | |
1064 | DEFINE_STRING_TABLE_LOOKUP(support, Support); |