]>
Commit | Line | Data |
---|---|---|
53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
74b2466e LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2014 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU Lesser General Public License as published by | |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public License | |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
19 | ***/ | |
20 | ||
ad867662 LP |
21 | #include <netinet/tcp.h> |
22 | ||
46f08bea | 23 | #include "af-list.h" |
b5efdb8a | 24 | #include "alloc-util.h" |
4ad7f276 | 25 | #include "dns-domain.h" |
3ffd4af2 LP |
26 | #include "fd-util.h" |
27 | #include "hostname-util.h" | |
28 | #include "missing.h" | |
29 | #include "random-util.h" | |
6db6a464 | 30 | #include "resolved-dnssd.h" |
74b2466e | 31 | #include "resolved-dns-scope.h" |
a2bf8a19 | 32 | #include "resolved-dns-zone.h" |
3ffd4af2 | 33 | #include "resolved-llmnr.h" |
b4f1862d | 34 | #include "resolved-mdns.h" |
3ffd4af2 LP |
35 | #include "socket-util.h" |
36 | #include "strv.h" | |
74b2466e | 37 | |
aea2429d LP |
38 | #define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC) |
39 | #define MULTICAST_RATELIMIT_BURST 1000 | |
40 | ||
9df3ba6c TG |
41 | /* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */ |
42 | #define MULTICAST_RESEND_TIMEOUT_MIN_USEC (100 * USEC_PER_MSEC) | |
43 | #define MULTICAST_RESEND_TIMEOUT_MAX_USEC (1 * USEC_PER_SEC) | |
44 | ||
0dd25fb9 | 45 | int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int family) { |
74b2466e LP |
46 | DnsScope *s; |
47 | ||
48 | assert(m); | |
49 | assert(ret); | |
50 | ||
51 | s = new0(DnsScope, 1); | |
52 | if (!s) | |
53 | return -ENOMEM; | |
54 | ||
55 | s->manager = m; | |
1716f6dc LP |
56 | s->link = l; |
57 | s->protocol = protocol; | |
58 | s->family = family; | |
9df3ba6c | 59 | s->resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC; |
74b2466e | 60 | |
ad6c0475 LP |
61 | if (protocol == DNS_PROTOCOL_DNS) { |
62 | /* Copy DNSSEC mode from the link if it is set there, | |
63 | * otherwise take the manager's DNSSEC mode. Note that | |
64 | * we copy this only at scope creation time, and do | |
65 | * not update it from the on, even if the setting | |
66 | * changes. */ | |
67 | ||
68 | if (l) | |
c69fa7e3 LP |
69 | s->dnssec_mode = link_get_dnssec_mode(l); |
70 | else | |
71 | s->dnssec_mode = manager_get_dnssec_mode(m); | |
658f7f02 LP |
72 | } else |
73 | s->dnssec_mode = DNSSEC_NO; | |
ad6c0475 | 74 | |
74b2466e LP |
75 | LIST_PREPEND(scopes, m->dns_scopes, s); |
76 | ||
1716f6dc | 77 | dns_scope_llmnr_membership(s, true); |
0db4c90a | 78 | dns_scope_mdns_membership(s, true); |
1716f6dc | 79 | |
46f08bea | 80 | log_debug("New scope on link %s, protocol %s, family %s", l ? l->name : "*", dns_protocol_to_string(protocol), family == AF_UNSPEC ? "*" : af_to_name(family)); |
1716f6dc | 81 | |
aea2429d LP |
82 | /* Enforce ratelimiting for the multicast protocols */ |
83 | RATELIMIT_INIT(s->ratelimit, MULTICAST_RATELIMIT_INTERVAL_USEC, MULTICAST_RATELIMIT_BURST); | |
84 | ||
74b2466e LP |
85 | *ret = s; |
86 | return 0; | |
87 | } | |
88 | ||
801ad6a6 | 89 | static void dns_scope_abort_transactions(DnsScope *s) { |
801ad6a6 | 90 | assert(s); |
1716f6dc | 91 | |
f9ebb22a LP |
92 | while (s->transactions) { |
93 | DnsTransaction *t = s->transactions; | |
94 | ||
faa133f3 LP |
95 | /* Abort the transaction, but make sure it is not |
96 | * freed while we still look at it */ | |
74b2466e | 97 | |
faa133f3 | 98 | t->block_gc++; |
f4e38037 LP |
99 | if (DNS_TRANSACTION_IS_LIVE(t->state)) |
100 | dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); | |
faa133f3 | 101 | t->block_gc--; |
74b2466e | 102 | |
ec2c5e43 | 103 | dns_transaction_free(t); |
74b2466e | 104 | } |
801ad6a6 LP |
105 | } |
106 | ||
107 | DnsScope* dns_scope_free(DnsScope *s) { | |
801ad6a6 LP |
108 | if (!s) |
109 | return NULL; | |
110 | ||
111 | log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->name : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family)); | |
112 | ||
113 | dns_scope_llmnr_membership(s, false); | |
0db4c90a | 114 | dns_scope_mdns_membership(s, false); |
801ad6a6 LP |
115 | dns_scope_abort_transactions(s); |
116 | ||
117 | while (s->query_candidates) | |
118 | dns_query_candidate_free(s->query_candidates); | |
74b2466e | 119 | |
f9ebb22a | 120 | hashmap_free(s->transactions_by_key); |
da0c630e | 121 | |
224b0e7a | 122 | ordered_hashmap_free_with_destructor(s->conflict_queue, dns_resource_record_unref); |
a4076574 LP |
123 | sd_event_source_unref(s->conflict_event_source); |
124 | ||
53fda2bb DR |
125 | sd_event_source_unref(s->announce_event_source); |
126 | ||
322345fd | 127 | dns_cache_flush(&s->cache); |
623a4c97 | 128 | dns_zone_flush(&s->zone); |
322345fd | 129 | |
74b2466e | 130 | LIST_REMOVE(scopes, s->manager->dns_scopes, s); |
6b430fdb | 131 | return mfree(s); |
74b2466e LP |
132 | } |
133 | ||
2c27fbca | 134 | DnsServer *dns_scope_get_dns_server(DnsScope *s) { |
74b2466e LP |
135 | assert(s); |
136 | ||
1716f6dc LP |
137 | if (s->protocol != DNS_PROTOCOL_DNS) |
138 | return NULL; | |
139 | ||
74b2466e LP |
140 | if (s->link) |
141 | return link_get_dns_server(s->link); | |
142 | else | |
143 | return manager_get_dns_server(s->manager); | |
144 | } | |
145 | ||
44db02d0 LP |
146 | unsigned dns_scope_get_n_dns_servers(DnsScope *s) { |
147 | unsigned n = 0; | |
148 | DnsServer *i; | |
149 | ||
150 | assert(s); | |
151 | ||
152 | if (s->protocol != DNS_PROTOCOL_DNS) | |
153 | return 0; | |
154 | ||
155 | if (s->link) | |
156 | i = s->link->dns_servers; | |
157 | else | |
158 | i = s->manager->dns_servers; | |
159 | ||
160 | for (; i; i = i->servers_next) | |
161 | n++; | |
162 | ||
163 | return n; | |
164 | } | |
165 | ||
74b2466e LP |
166 | void dns_scope_next_dns_server(DnsScope *s) { |
167 | assert(s); | |
168 | ||
1716f6dc LP |
169 | if (s->protocol != DNS_PROTOCOL_DNS) |
170 | return; | |
171 | ||
74b2466e LP |
172 | if (s->link) |
173 | link_next_dns_server(s->link); | |
174 | else | |
175 | manager_next_dns_server(s->manager); | |
176 | } | |
177 | ||
9df3ba6c TG |
178 | void dns_scope_packet_received(DnsScope *s, usec_t rtt) { |
179 | assert(s); | |
180 | ||
84129d46 LP |
181 | if (rtt <= s->max_rtt) |
182 | return; | |
183 | ||
184 | s->max_rtt = rtt; | |
185 | s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
9df3ba6c TG |
186 | } |
187 | ||
188 | void dns_scope_packet_lost(DnsScope *s, usec_t usec) { | |
189 | assert(s); | |
190 | ||
191 | if (s->resend_timeout <= usec) | |
192 | s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
193 | } | |
194 | ||
519ef046 | 195 | static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) { |
1716f6dc LP |
196 | union in_addr_union addr; |
197 | int ifindex = 0, r; | |
0dd25fb9 | 198 | int family; |
1716f6dc | 199 | uint32_t mtu; |
74b2466e LP |
200 | |
201 | assert(s); | |
202 | assert(p); | |
1716f6dc | 203 | assert(p->protocol == s->protocol); |
ad867662 LP |
204 | |
205 | if (s->link) { | |
1716f6dc | 206 | mtu = s->link->mtu; |
74b2466e | 207 | ifindex = s->link->ifindex; |
1716f6dc | 208 | } else |
e1c95994 | 209 | mtu = manager_find_mtu(s->manager); |
74b2466e | 210 | |
106784eb | 211 | switch (s->protocol) { |
519ef046 | 212 | |
106784eb | 213 | case DNS_PROTOCOL_DNS: |
519ef046 | 214 | assert(fd >= 0); |
9c5e12a4 | 215 | |
623a4c97 | 216 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 217 | return -EOPNOTSUPP; |
623a4c97 | 218 | |
1716f6dc LP |
219 | if (p->size > DNS_PACKET_UNICAST_SIZE_MAX) |
220 | return -EMSGSIZE; | |
221 | ||
a0166609 | 222 | if (p->size + UDP_PACKET_HEADER_SIZE > mtu) |
1716f6dc LP |
223 | return -EMSGSIZE; |
224 | ||
72290734 TG |
225 | r = manager_write(s->manager, fd, p); |
226 | if (r < 0) | |
227 | return r; | |
228 | ||
106784eb | 229 | break; |
1716f6dc | 230 | |
106784eb | 231 | case DNS_PROTOCOL_LLMNR: |
519ef046 LP |
232 | assert(fd < 0); |
233 | ||
1716f6dc | 234 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 235 | return -EOPNOTSUPP; |
1716f6dc | 236 | |
aea2429d LP |
237 | if (!ratelimit_test(&s->ratelimit)) |
238 | return -EBUSY; | |
239 | ||
1716f6dc | 240 | family = s->family; |
1716f6dc LP |
241 | |
242 | if (family == AF_INET) { | |
243 | addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; | |
1716f6dc LP |
244 | fd = manager_llmnr_ipv4_udp_fd(s->manager); |
245 | } else if (family == AF_INET6) { | |
246 | addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS; | |
247 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
1716f6dc LP |
248 | } else |
249 | return -EAFNOSUPPORT; | |
250 | if (fd < 0) | |
251 | return fd; | |
72290734 | 252 | |
b30bf55d | 253 | r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, NULL, p); |
b4f1862d DM |
254 | if (r < 0) |
255 | return r; | |
256 | ||
257 | break; | |
258 | ||
259 | case DNS_PROTOCOL_MDNS: | |
519ef046 LP |
260 | assert(fd < 0); |
261 | ||
b4f1862d DM |
262 | if (!ratelimit_test(&s->ratelimit)) |
263 | return -EBUSY; | |
264 | ||
265 | family = s->family; | |
266 | ||
267 | if (family == AF_INET) { | |
268 | addr.in = MDNS_MULTICAST_IPV4_ADDRESS; | |
269 | fd = manager_mdns_ipv4_fd(s->manager); | |
270 | } else if (family == AF_INET6) { | |
271 | addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS; | |
272 | fd = manager_mdns_ipv6_fd(s->manager); | |
273 | } else | |
274 | return -EAFNOSUPPORT; | |
275 | if (fd < 0) | |
276 | return fd; | |
277 | ||
b30bf55d | 278 | r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, NULL, p); |
72290734 TG |
279 | if (r < 0) |
280 | return r; | |
106784eb DM |
281 | |
282 | break; | |
283 | ||
284 | default: | |
74b2466e | 285 | return -EAFNOSUPPORT; |
106784eb | 286 | } |
74b2466e | 287 | |
74b2466e LP |
288 | return 1; |
289 | } | |
290 | ||
519ef046 | 291 | int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) { |
80a62095 DM |
292 | int r; |
293 | ||
294 | assert(s); | |
295 | assert(p); | |
296 | assert(p->protocol == s->protocol); | |
519ef046 | 297 | assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0)); |
80a62095 DM |
298 | |
299 | do { | |
300 | /* If there are multiple linked packets, set the TC bit in all but the last of them */ | |
301 | if (p->more) { | |
302 | assert(p->protocol == DNS_PROTOCOL_MDNS); | |
261f3673 | 303 | dns_packet_set_flags(p, true, true); |
80a62095 DM |
304 | } |
305 | ||
519ef046 | 306 | r = dns_scope_emit_one(s, fd, p); |
80a62095 DM |
307 | if (r < 0) |
308 | return r; | |
309 | ||
310 | p = p->more; | |
519ef046 | 311 | } while (p); |
80a62095 DM |
312 | |
313 | return 0; | |
314 | } | |
315 | ||
519ef046 LP |
316 | static int dns_scope_socket( |
317 | DnsScope *s, | |
318 | int type, | |
319 | int family, | |
320 | const union in_addr_union *address, | |
321 | DnsServer *server, | |
322 | uint16_t port) { | |
323 | ||
ad867662 LP |
324 | _cleanup_close_ int fd = -1; |
325 | union sockaddr_union sa = {}; | |
326 | socklen_t salen; | |
623a4c97 | 327 | static const int one = 1; |
c10d6bdb | 328 | int r, ifindex; |
ad867662 LP |
329 | |
330 | assert(s); | |
be808ea0 | 331 | |
519ef046 LP |
332 | if (server) { |
333 | assert(family == AF_UNSPEC); | |
334 | assert(!address); | |
be808ea0 | 335 | |
2817157b LP |
336 | ifindex = dns_server_ifindex(server); |
337 | ||
519ef046 LP |
338 | sa.sa.sa_family = server->family; |
339 | if (server->family == AF_INET) { | |
623a4c97 | 340 | sa.in.sin_port = htobe16(port); |
519ef046 | 341 | sa.in.sin_addr = server->address.in; |
623a4c97 | 342 | salen = sizeof(sa.in); |
519ef046 | 343 | } else if (server->family == AF_INET6) { |
623a4c97 | 344 | sa.in6.sin6_port = htobe16(port); |
519ef046 | 345 | sa.in6.sin6_addr = server->address.in6; |
2817157b | 346 | sa.in6.sin6_scope_id = ifindex; |
623a4c97 LP |
347 | salen = sizeof(sa.in6); |
348 | } else | |
349 | return -EAFNOSUPPORT; | |
350 | } else { | |
519ef046 LP |
351 | assert(family != AF_UNSPEC); |
352 | assert(address); | |
353 | ||
623a4c97 | 354 | sa.sa.sa_family = family; |
2817157b | 355 | ifindex = s->link ? s->link->ifindex : 0; |
623a4c97 LP |
356 | |
357 | if (family == AF_INET) { | |
358 | sa.in.sin_port = htobe16(port); | |
359 | sa.in.sin_addr = address->in; | |
360 | salen = sizeof(sa.in); | |
361 | } else if (family == AF_INET6) { | |
362 | sa.in6.sin6_port = htobe16(port); | |
363 | sa.in6.sin6_addr = address->in6; | |
2817157b | 364 | sa.in6.sin6_scope_id = ifindex; |
623a4c97 LP |
365 | salen = sizeof(sa.in6); |
366 | } else | |
367 | return -EAFNOSUPPORT; | |
368 | } | |
ad867662 | 369 | |
0db64366 | 370 | fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
ad867662 LP |
371 | if (fd < 0) |
372 | return -errno; | |
373 | ||
0db64366 TG |
374 | if (type == SOCK_STREAM) { |
375 | r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); | |
376 | if (r < 0) | |
377 | return -errno; | |
378 | } | |
623a4c97 LP |
379 | |
380 | if (s->link) { | |
2817157b | 381 | be32_t ifindex_be = htobe32(ifindex); |
623a4c97 LP |
382 | |
383 | if (sa.sa.sa_family == AF_INET) { | |
2817157b | 384 | r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
385 | if (r < 0) |
386 | return -errno; | |
387 | } else if (sa.sa.sa_family == AF_INET6) { | |
2817157b | 388 | r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
389 | if (r < 0) |
390 | return -errno; | |
391 | } | |
392 | } | |
393 | ||
394 | if (s->protocol == DNS_PROTOCOL_LLMNR) { | |
bf3f1271 | 395 | /* RFC 4795, section 2.5 requires the TTL to be set to 1 */ |
623a4c97 LP |
396 | |
397 | if (sa.sa.sa_family == AF_INET) { | |
398 | r = setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); | |
399 | if (r < 0) | |
400 | return -errno; | |
401 | } else if (sa.sa.sa_family == AF_INET6) { | |
402 | r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); | |
403 | if (r < 0) | |
404 | return -errno; | |
405 | } | |
406 | } | |
ad867662 LP |
407 | |
408 | r = connect(fd, &sa.sa, salen); | |
409 | if (r < 0 && errno != EINPROGRESS) | |
410 | return -errno; | |
411 | ||
c10d6bdb | 412 | return TAKE_FD(fd); |
ad867662 LP |
413 | } |
414 | ||
519ef046 LP |
415 | int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) { |
416 | return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port); | |
0db64366 TG |
417 | } |
418 | ||
519ef046 LP |
419 | int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port) { |
420 | return dns_scope_socket(s, SOCK_STREAM, family, address, server, port); | |
0db64366 TG |
421 | } |
422 | ||
51323288 | 423 | DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) { |
a51c1048 | 424 | DnsSearchDomain *d; |
74b2466e LP |
425 | |
426 | assert(s); | |
427 | assert(domain); | |
428 | ||
28b9b764 LP |
429 | /* Checks if the specified domain is something to look up on |
430 | * this scope. Note that this accepts non-qualified hostnames, | |
431 | * i.e. those without any search path prefixed yet. */ | |
432 | ||
51323288 LP |
433 | if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex)) |
434 | return DNS_SCOPE_NO; | |
435 | ||
931851e8 | 436 | if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0) |
51323288 LP |
437 | return DNS_SCOPE_NO; |
438 | ||
78c6a153 LP |
439 | /* Never resolve any loopback hostname or IP address via DNS, |
440 | * LLMNR or mDNS. Instead, always rely on synthesized RRs for | |
441 | * these. */ | |
442 | if (is_localhost(domain) || | |
443 | dns_name_endswith(domain, "127.in-addr.arpa") > 0 || | |
9436e8ca LP |
444 | dns_name_equal(domain, "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) |
445 | return DNS_SCOPE_NO; | |
446 | ||
c9ad0edb LP |
447 | /* Never respond to some of the domains listed in RFC6303 */ |
448 | if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 || | |
449 | dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 || | |
450 | dns_name_equal(domain, "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa") > 0) | |
451 | return DNS_SCOPE_NO; | |
452 | ||
7bcffc2e LP |
453 | /* Never respond to some of the domains listed in RFC6761 */ |
454 | if (dns_name_endswith(domain, "invalid") > 0) | |
455 | return DNS_SCOPE_NO; | |
456 | ||
106784eb | 457 | switch (s->protocol) { |
801ad6a6 | 458 | |
613dca46 LP |
459 | case DNS_PROTOCOL_DNS: { |
460 | DnsServer *dns_server; | |
461 | ||
462 | /* Never route things to scopes that lack DNS servers */ | |
463 | dns_server = dns_scope_get_dns_server(s); | |
464 | if (!dns_server) | |
465 | return DNS_SCOPE_NO; | |
466 | ||
467 | /* Always honour search domains for routing queries, except if this scope lacks DNS servers. Note that | |
468 | * we return DNS_SCOPE_YES here, rather than just DNS_SCOPE_MAYBE, which means other wildcard scopes | |
469 | * won't be considered anymore. */ | |
470 | LIST_FOREACH(domains, d, dns_scope_get_search_domains(s)) | |
471 | if (dns_name_endswith(domain, d->name) > 0) | |
472 | return DNS_SCOPE_YES; | |
473 | ||
474 | /* If the DNS server has route-only domains, don't send other requests to it. This would be a privacy | |
475 | * violation, will most probably fail anyway, and adds unnecessary load. */ | |
476 | if (dns_server_limited_domains(dns_server)) | |
477 | return DNS_SCOPE_NO; | |
801ad6a6 | 478 | |
28b9b764 LP |
479 | /* Exclude link-local IP ranges */ |
480 | if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 && | |
c9ad0edb LP |
481 | dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 && |
482 | dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 && | |
483 | dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 && | |
b43d96b0 DM |
484 | dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 && |
485 | /* If networks use .local in their private setups, they are supposed to also add .local to their search | |
486 | * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't | |
487 | * send such queries ordinary DNS servers. */ | |
488 | dns_name_endswith(domain, "local") == 0) | |
faa133f3 | 489 | return DNS_SCOPE_MAYBE; |
1716f6dc | 490 | |
faa133f3 | 491 | return DNS_SCOPE_NO; |
613dca46 | 492 | } |
1716f6dc | 493 | |
106784eb | 494 | case DNS_PROTOCOL_MDNS: |
78c6a153 LP |
495 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
496 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || | |
497 | (dns_name_endswith(domain, "local") > 0 && /* only resolve names ending in .local via mDNS */ | |
498 | dns_name_equal(domain, "local") == 0 && /* but not the single-label "local" name itself */ | |
499 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via mDNS */ | |
d8b7e75f | 500 | return DNS_SCOPE_MAYBE; |
74b2466e LP |
501 | |
502 | return DNS_SCOPE_NO; | |
74b2466e | 503 | |
106784eb | 504 | case DNS_PROTOCOL_LLMNR: |
78c6a153 LP |
505 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
506 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || | |
dc477e73 | 507 | (dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */ |
78c6a153 LP |
508 | !is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */ |
509 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */ | |
1716f6dc | 510 | return DNS_SCOPE_MAYBE; |
74b2466e | 511 | |
1716f6dc | 512 | return DNS_SCOPE_NO; |
74b2466e | 513 | |
106784eb DM |
514 | default: |
515 | assert_not_reached("Unknown scope protocol"); | |
516 | } | |
1716f6dc LP |
517 | } |
518 | ||
011696f7 LP |
519 | bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) { |
520 | int key_family; | |
521 | ||
1716f6dc LP |
522 | assert(s); |
523 | assert(key); | |
524 | ||
28b9b764 LP |
525 | /* Check if it makes sense to resolve the specified key on |
526 | * this scope. Note that this call assumes as fully qualified | |
527 | * name, i.e. the search suffixes already appended. */ | |
528 | ||
011696f7 LP |
529 | if (key->class != DNS_CLASS_IN) |
530 | return false; | |
531 | ||
28b9b764 LP |
532 | if (s->protocol == DNS_PROTOCOL_DNS) { |
533 | ||
e5abebab | 534 | /* On classic DNS, looking up non-address RRs is always |
28b9b764 LP |
535 | * fine. (Specifically, we want to permit looking up |
536 | * DNSKEY and DS records on the root and top-level | |
537 | * domains.) */ | |
538 | if (!dns_resource_key_is_address(key)) | |
539 | return true; | |
540 | ||
541 | /* However, we refuse to look up A and AAAA RRs on the | |
542 | * root and single-label domains, under the assumption | |
543 | * that those should be resolved via LLMNR or search | |
544 | * path only, and should not be leaked onto the | |
545 | * internet. */ | |
1c02e7ba ZJS |
546 | return !(dns_name_is_single_label(dns_resource_key_name(key)) || |
547 | dns_name_is_root(dns_resource_key_name(key))); | |
28b9b764 | 548 | } |
1716f6dc LP |
549 | |
550 | /* On mDNS and LLMNR, send A and AAAA queries only on the | |
551 | * respective scopes */ | |
552 | ||
011696f7 LP |
553 | key_family = dns_type_to_af(key->type); |
554 | if (key_family < 0) | |
555 | return true; | |
1716f6dc | 556 | |
011696f7 | 557 | return key_family == s->family; |
1716f6dc LP |
558 | } |
559 | ||
0db4c90a | 560 | static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) { |
1716f6dc LP |
561 | int fd; |
562 | ||
5ba73e9b | 563 | assert(s); |
5ba73e9b LP |
564 | assert(s->link); |
565 | ||
1716f6dc LP |
566 | if (s->family == AF_INET) { |
567 | struct ip_mreqn mreqn = { | |
0db4c90a | 568 | .imr_multiaddr = in, |
1716f6dc LP |
569 | .imr_ifindex = s->link->ifindex, |
570 | }; | |
571 | ||
d37baf40 DR |
572 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
573 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
574 | else | |
575 | fd = manager_mdns_ipv4_fd(s->manager); | |
576 | ||
1716f6dc LP |
577 | if (fd < 0) |
578 | return fd; | |
579 | ||
7b4c2ee7 LP |
580 | /* Always first try to drop membership before we add |
581 | * one. This is necessary on some devices, such as | |
582 | * veth. */ | |
583 | if (b) | |
dc751688 | 584 | (void) setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)); |
7b4c2ee7 | 585 | |
1716f6dc LP |
586 | if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0) |
587 | return -errno; | |
588 | ||
589 | } else if (s->family == AF_INET6) { | |
590 | struct ipv6_mreq mreq = { | |
0db4c90a | 591 | .ipv6mr_multiaddr = in6, |
1716f6dc LP |
592 | .ipv6mr_interface = s->link->ifindex, |
593 | }; | |
594 | ||
d37baf40 DR |
595 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
596 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
597 | else | |
598 | fd = manager_mdns_ipv6_fd(s->manager); | |
599 | ||
1716f6dc LP |
600 | if (fd < 0) |
601 | return fd; | |
602 | ||
7b4c2ee7 | 603 | if (b) |
dc751688 | 604 | (void) setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)); |
7b4c2ee7 | 605 | |
1716f6dc LP |
606 | if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) |
607 | return -errno; | |
608 | } else | |
609 | return -EAFNOSUPPORT; | |
610 | ||
611 | return 0; | |
74b2466e | 612 | } |
623a4c97 | 613 | |
0db4c90a | 614 | int dns_scope_llmnr_membership(DnsScope *s, bool b) { |
f471bc11 | 615 | assert(s); |
0db4c90a DM |
616 | |
617 | if (s->protocol != DNS_PROTOCOL_LLMNR) | |
618 | return 0; | |
619 | ||
620 | return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS); | |
621 | } | |
622 | ||
623 | int dns_scope_mdns_membership(DnsScope *s, bool b) { | |
f471bc11 | 624 | assert(s); |
0db4c90a DM |
625 | |
626 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
627 | return 0; | |
628 | ||
629 | return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS); | |
630 | } | |
631 | ||
3b991089 | 632 | int dns_scope_make_reply_packet( |
ec2c5e43 LP |
633 | DnsScope *s, |
634 | uint16_t id, | |
635 | int rcode, | |
636 | DnsQuestion *q, | |
637 | DnsAnswer *answer, | |
638 | DnsAnswer *soa, | |
639 | bool tentative, | |
640 | DnsPacket **ret) { | |
641 | ||
623a4c97 | 642 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
623a4c97 LP |
643 | int r; |
644 | ||
645 | assert(s); | |
a4076574 | 646 | assert(ret); |
623a4c97 | 647 | |
501e8eb0 LP |
648 | if (dns_question_isempty(q) && |
649 | dns_answer_isempty(answer) && | |
650 | dns_answer_isempty(soa)) | |
623a4c97 LP |
651 | return -EINVAL; |
652 | ||
51027656 | 653 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
623a4c97 LP |
654 | if (r < 0) |
655 | return r; | |
656 | ||
657 | DNS_PACKET_HEADER(p)->id = id; | |
ea917db9 LP |
658 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( |
659 | 1 /* qr */, | |
660 | 0 /* opcode */, | |
661 | 0 /* c */, | |
662 | 0 /* tc */, | |
ec2c5e43 | 663 | tentative, |
ea917db9 LP |
664 | 0 /* (ra) */, |
665 | 0 /* (ad) */, | |
666 | 0 /* (cd) */, | |
667 | rcode)); | |
623a4c97 | 668 | |
f471bc11 LP |
669 | r = dns_packet_append_question(p, q); |
670 | if (r < 0) | |
671 | return r; | |
672 | DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q)); | |
8bf52d3d | 673 | |
f471bc11 LP |
674 | r = dns_packet_append_answer(p, answer); |
675 | if (r < 0) | |
676 | return r; | |
677 | DNS_PACKET_HEADER(p)->ancount = htobe16(dns_answer_size(answer)); | |
8bf52d3d | 678 | |
f471bc11 LP |
679 | r = dns_packet_append_answer(p, soa); |
680 | if (r < 0) | |
681 | return r; | |
682 | DNS_PACKET_HEADER(p)->arcount = htobe16(dns_answer_size(soa)); | |
623a4c97 LP |
683 | |
684 | *ret = p; | |
685 | p = NULL; | |
686 | ||
687 | return 0; | |
688 | } | |
689 | ||
a4076574 | 690 | static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) { |
2a3900d7 LP |
691 | DnsResourceRecord *rr; |
692 | DnsResourceKey *key; | |
a4076574 LP |
693 | |
694 | assert(s); | |
695 | assert(p); | |
696 | ||
2a3900d7 LP |
697 | DNS_QUESTION_FOREACH(key, p->question) |
698 | dns_zone_verify_conflicts(&s->zone, key); | |
699 | ||
700 | DNS_ANSWER_FOREACH(rr, p->answer) | |
701 | dns_zone_verify_conflicts(&s->zone, rr->key); | |
a4076574 LP |
702 | } |
703 | ||
623a4c97 | 704 | void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { |
8bf52d3d | 705 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; |
b30bf55d | 706 | _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; |
5032b16d | 707 | DnsResourceKey *key = NULL; |
ec2c5e43 | 708 | bool tentative = false; |
b30bf55d | 709 | int r; |
623a4c97 LP |
710 | |
711 | assert(s); | |
712 | assert(p); | |
713 | ||
714 | if (p->protocol != DNS_PROTOCOL_LLMNR) | |
715 | return; | |
716 | ||
2442b93d LP |
717 | if (p->ipproto == IPPROTO_UDP) { |
718 | /* Don't accept UDP queries directed to anything but | |
719 | * the LLMNR multicast addresses. See RFC 4795, | |
d076c6f9 | 720 | * section 2.5. */ |
2442b93d LP |
721 | |
722 | if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS)) | |
723 | return; | |
724 | ||
725 | if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS)) | |
726 | return; | |
727 | } | |
728 | ||
623a4c97 LP |
729 | r = dns_packet_extract(p); |
730 | if (r < 0) { | |
b30bf55d | 731 | log_debug_errno(r, "Failed to extract resource records from incoming packet: %m"); |
623a4c97 LP |
732 | return; |
733 | } | |
734 | ||
8b757a38 | 735 | if (DNS_PACKET_LLMNR_C(p)) { |
a4076574 LP |
736 | /* Somebody notified us about a possible conflict */ |
737 | dns_scope_verify_conflicts(s, p); | |
ea917db9 LP |
738 | return; |
739 | } | |
740 | ||
501e8eb0 | 741 | assert(dns_question_size(p->question) == 1); |
5032b16d LP |
742 | key = p->question->keys[0]; |
743 | ||
97ebebbc | 744 | r = dns_zone_lookup(&s->zone, key, 0, &answer, &soa, &tentative); |
623a4c97 | 745 | if (r < 0) { |
da927ba9 | 746 | log_debug_errno(r, "Failed to lookup key: %m"); |
623a4c97 LP |
747 | return; |
748 | } | |
749 | if (r == 0) | |
750 | return; | |
751 | ||
fcf57f9c LP |
752 | if (answer) |
753 | dns_answer_order_by_scope(answer, in_addr_is_link_local(p->family, &p->sender) > 0); | |
af93291c | 754 | |
ec2c5e43 | 755 | r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, tentative, &reply); |
623a4c97 | 756 | if (r < 0) { |
da927ba9 | 757 | log_debug_errno(r, "Failed to build reply packet: %m"); |
623a4c97 LP |
758 | return; |
759 | } | |
760 | ||
b30bf55d | 761 | if (stream) { |
623a4c97 | 762 | r = dns_stream_write_packet(stream, reply); |
b30bf55d LP |
763 | if (r < 0) { |
764 | log_debug_errno(r, "Failed to enqueue reply packet: %m"); | |
765 | return; | |
766 | } | |
767 | ||
768 | /* Let's take an extra reference on this stream, so that it stays around after returning. The reference | |
769 | * will be dangling until the stream is disconnected, and the default completion handler of the stream | |
770 | * will then unref the stream and destroy it */ | |
771 | if (DNS_STREAM_QUEUED(stream)) | |
772 | dns_stream_ref(stream); | |
773 | } else { | |
774 | int fd; | |
775 | ||
aea2429d LP |
776 | if (!ratelimit_test(&s->ratelimit)) |
777 | return; | |
778 | ||
623a4c97 LP |
779 | if (p->family == AF_INET) |
780 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
781 | else if (p->family == AF_INET6) | |
782 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
783 | else { | |
784 | log_debug("Unknown protocol"); | |
785 | return; | |
786 | } | |
787 | if (fd < 0) { | |
da927ba9 | 788 | log_debug_errno(fd, "Failed to get reply socket: %m"); |
623a4c97 LP |
789 | return; |
790 | } | |
791 | ||
6e068472 LP |
792 | /* Note that we always immediately reply to all LLMNR |
793 | * requests, and do not wait any time, since we | |
794 | * verified uniqueness for all records. Also see RFC | |
795 | * 4795, Section 2.7 */ | |
796 | ||
b30bf55d LP |
797 | r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, NULL, reply); |
798 | if (r < 0) { | |
799 | log_debug_errno(r, "Failed to send reply packet: %m"); | |
800 | return; | |
801 | } | |
623a4c97 LP |
802 | } |
803 | } | |
ec2c5e43 | 804 | |
f52e61da | 805 | DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok) { |
ec2c5e43 LP |
806 | DnsTransaction *t; |
807 | ||
808 | assert(scope); | |
f52e61da | 809 | assert(key); |
ec2c5e43 | 810 | |
da0c630e LP |
811 | /* Try to find an ongoing transaction that is a equal to the |
812 | * specified question */ | |
f9ebb22a | 813 | t = hashmap_get(scope->transactions_by_key, key); |
4a46ed1b LP |
814 | if (!t) |
815 | return NULL; | |
dc4d47e2 | 816 | |
da0c630e LP |
817 | /* Refuse reusing transactions that completed based on cached |
818 | * data instead of a real packet, if that's requested. */ | |
819 | if (!cache_ok && | |
3bbdc31d | 820 | IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) && |
c3bc53e6 | 821 | t->answer_source != DNS_TRANSACTION_NETWORK) |
da0c630e | 822 | return NULL; |
ec2c5e43 | 823 | |
da0c630e | 824 | return t; |
ec2c5e43 | 825 | } |
a4076574 LP |
826 | |
827 | static int dns_scope_make_conflict_packet( | |
828 | DnsScope *s, | |
829 | DnsResourceRecord *rr, | |
830 | DnsPacket **ret) { | |
831 | ||
832 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
833 | int r; | |
834 | ||
835 | assert(s); | |
836 | assert(rr); | |
837 | assert(ret); | |
838 | ||
51027656 | 839 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
a4076574 LP |
840 | if (r < 0) |
841 | return r; | |
842 | ||
843 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( | |
844 | 0 /* qr */, | |
845 | 0 /* opcode */, | |
846 | 1 /* conflict */, | |
847 | 0 /* tc */, | |
848 | 0 /* t */, | |
849 | 0 /* (ra) */, | |
850 | 0 /* (ad) */, | |
851 | 0 /* (cd) */, | |
852 | 0)); | |
fe2dfc8b DM |
853 | |
854 | /* For mDNS, the transaction ID should always be 0 */ | |
855 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
856 | random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t)); | |
857 | ||
a4076574 LP |
858 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); |
859 | DNS_PACKET_HEADER(p)->arcount = htobe16(1); | |
860 | ||
58ab31d5 | 861 | r = dns_packet_append_key(p, rr->key, 0, NULL); |
a4076574 LP |
862 | if (r < 0) |
863 | return r; | |
864 | ||
58ab31d5 | 865 | r = dns_packet_append_rr(p, rr, 0, NULL, NULL); |
a4076574 LP |
866 | if (r < 0) |
867 | return r; | |
868 | ||
869 | *ret = p; | |
870 | p = NULL; | |
871 | ||
872 | return 0; | |
873 | } | |
874 | ||
875 | static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata) { | |
876 | DnsScope *scope = userdata; | |
877 | int r; | |
878 | ||
879 | assert(es); | |
880 | assert(scope); | |
881 | ||
882 | scope->conflict_event_source = sd_event_source_unref(scope->conflict_event_source); | |
883 | ||
884 | for (;;) { | |
432d108c | 885 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
a4076574 LP |
886 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; |
887 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
888 | ||
432d108c DR |
889 | key = ordered_hashmap_first_key(scope->conflict_queue); |
890 | if (!key) | |
a4076574 LP |
891 | break; |
892 | ||
432d108c DR |
893 | rr = ordered_hashmap_remove(scope->conflict_queue, key); |
894 | assert(rr); | |
895 | ||
a4076574 LP |
896 | r = dns_scope_make_conflict_packet(scope, rr, &p); |
897 | if (r < 0) { | |
da927ba9 | 898 | log_error_errno(r, "Failed to make conflict packet: %m"); |
a4076574 LP |
899 | return 0; |
900 | } | |
901 | ||
519ef046 | 902 | r = dns_scope_emit_udp(scope, -1, p); |
a4076574 | 903 | if (r < 0) |
da927ba9 | 904 | log_debug_errno(r, "Failed to send conflict packet: %m"); |
a4076574 LP |
905 | } |
906 | ||
907 | return 0; | |
908 | } | |
909 | ||
910 | int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) { | |
911 | usec_t jitter; | |
912 | int r; | |
913 | ||
914 | assert(scope); | |
915 | assert(rr); | |
916 | ||
917 | /* We don't send these queries immediately. Instead, we queue | |
918 | * them, and send them after some jitter delay. */ | |
1e43061b | 919 | r = ordered_hashmap_ensure_allocated(&scope->conflict_queue, &dns_resource_key_hash_ops); |
a4076574 LP |
920 | if (r < 0) { |
921 | log_oom(); | |
922 | return r; | |
923 | } | |
924 | ||
925 | /* We only place one RR per key in the conflict | |
926 | * messages, not all of them. That should be enough to | |
927 | * indicate where there might be a conflict */ | |
1e43061b | 928 | r = ordered_hashmap_put(scope->conflict_queue, rr->key, rr); |
4c701096 | 929 | if (IN_SET(r, 0, -EEXIST)) |
a4076574 | 930 | return 0; |
f647962d MS |
931 | if (r < 0) |
932 | return log_debug_errno(r, "Failed to queue conflicting RR: %m"); | |
a4076574 | 933 | |
432d108c | 934 | dns_resource_key_ref(rr->key); |
a4076574 LP |
935 | dns_resource_record_ref(rr); |
936 | ||
937 | if (scope->conflict_event_source) | |
938 | return 0; | |
939 | ||
940 | random_bytes(&jitter, sizeof(jitter)); | |
941 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
942 | ||
943 | r = sd_event_add_time(scope->manager->event, | |
944 | &scope->conflict_event_source, | |
945 | clock_boottime_or_monotonic(), | |
946 | now(clock_boottime_or_monotonic()) + jitter, | |
947 | LLMNR_JITTER_INTERVAL_USEC, | |
948 | on_conflict_dispatch, scope); | |
f647962d MS |
949 | if (r < 0) |
950 | return log_debug_errno(r, "Failed to add conflict dispatch event: %m"); | |
a4076574 | 951 | |
aa4a9deb LP |
952 | (void) sd_event_source_set_description(scope->conflict_event_source, "scope-conflict"); |
953 | ||
a4076574 LP |
954 | return 0; |
955 | } | |
956 | ||
957 | void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) { | |
c1227a18 | 958 | DnsResourceRecord *rr; |
a4076574 LP |
959 | int r; |
960 | ||
961 | assert(scope); | |
962 | assert(p); | |
963 | ||
53fda2bb | 964 | if (!IN_SET(p->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) |
a4076574 LP |
965 | return; |
966 | ||
967 | if (DNS_PACKET_RRCOUNT(p) <= 0) | |
968 | return; | |
969 | ||
53fda2bb DR |
970 | if (p->protocol == DNS_PROTOCOL_LLMNR) { |
971 | if (DNS_PACKET_LLMNR_C(p) != 0) | |
972 | return; | |
a4076574 | 973 | |
53fda2bb DR |
974 | if (DNS_PACKET_LLMNR_T(p) != 0) |
975 | return; | |
976 | } | |
a4076574 LP |
977 | |
978 | if (manager_our_packet(scope->manager, p)) | |
979 | return; | |
980 | ||
981 | r = dns_packet_extract(p); | |
982 | if (r < 0) { | |
da927ba9 | 983 | log_debug_errno(r, "Failed to extract packet: %m"); |
a4076574 LP |
984 | return; |
985 | } | |
986 | ||
987 | log_debug("Checking for conflicts..."); | |
988 | ||
c1227a18 | 989 | DNS_ANSWER_FOREACH(rr, p->answer) { |
cfcc8dcc | 990 | /* No conflict if it is DNS-SD RR used for service enumeration. */ |
c1227a18 | 991 | if (dns_resource_key_is_dnssd_ptr(rr->key)) |
cfcc8dcc DR |
992 | continue; |
993 | ||
a4076574 LP |
994 | /* Check for conflicts against the local zone. If we |
995 | * found one, we won't check any further */ | |
c1227a18 | 996 | r = dns_zone_check_conflicts(&scope->zone, rr); |
a4076574 LP |
997 | if (r != 0) |
998 | continue; | |
999 | ||
1000 | /* Check for conflicts against the local cache. If so, | |
1001 | * send out an advisory query, to inform everybody */ | |
c1227a18 | 1002 | r = dns_cache_check_conflicts(&scope->cache, rr, p->family, &p->sender); |
a4076574 LP |
1003 | if (r <= 0) |
1004 | continue; | |
1005 | ||
c1227a18 | 1006 | dns_scope_notify_conflict(scope, rr); |
a4076574 LP |
1007 | } |
1008 | } | |
4d506d6b LP |
1009 | |
1010 | void dns_scope_dump(DnsScope *s, FILE *f) { | |
1011 | assert(s); | |
1012 | ||
1013 | if (!f) | |
1014 | f = stdout; | |
1015 | ||
1016 | fputs("[Scope protocol=", f); | |
1017 | fputs(dns_protocol_to_string(s->protocol), f); | |
1018 | ||
1019 | if (s->link) { | |
1020 | fputs(" interface=", f); | |
1021 | fputs(s->link->name, f); | |
1022 | } | |
1023 | ||
1024 | if (s->family != AF_UNSPEC) { | |
1025 | fputs(" family=", f); | |
1026 | fputs(af_to_name(s->family), f); | |
1027 | } | |
1028 | ||
1029 | fputs("]\n", f); | |
1030 | ||
1031 | if (!dns_zone_is_empty(&s->zone)) { | |
1032 | fputs("ZONE:\n", f); | |
1033 | dns_zone_dump(&s->zone, f); | |
1034 | } | |
1035 | ||
1036 | if (!dns_cache_is_empty(&s->cache)) { | |
1037 | fputs("CACHE:\n", f); | |
1038 | dns_cache_dump(&s->cache, f); | |
1039 | } | |
1040 | } | |
a51c1048 LP |
1041 | |
1042 | DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s) { | |
801ad6a6 LP |
1043 | assert(s); |
1044 | ||
a51c1048 LP |
1045 | if (s->protocol != DNS_PROTOCOL_DNS) |
1046 | return NULL; | |
1047 | ||
1048 | if (s->link) | |
1049 | return s->link->search_domains; | |
1050 | ||
28b9b764 | 1051 | return s->manager->search_domains; |
801ad6a6 LP |
1052 | } |
1053 | ||
dc477e73 | 1054 | bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name) { |
801ad6a6 LP |
1055 | assert(s); |
1056 | ||
1057 | if (s->protocol != DNS_PROTOCOL_DNS) | |
dc477e73 | 1058 | return false; |
801ad6a6 | 1059 | |
dc477e73 | 1060 | return dns_name_is_single_label(name); |
801ad6a6 | 1061 | } |
edbcc1fd LP |
1062 | |
1063 | bool dns_scope_network_good(DnsScope *s) { | |
edbcc1fd LP |
1064 | /* Checks whether the network is in good state for lookups on this scope. For mDNS/LLMNR/Classic DNS scopes |
1065 | * bound to links this is easy, as they don't even exist if the link isn't in a suitable state. For the global | |
1066 | * DNS scope we check whether there are any links that are up and have an address. */ | |
1067 | ||
1068 | if (s->link) | |
1069 | return true; | |
1070 | ||
011696f7 | 1071 | return manager_routable(s->manager, AF_UNSPEC); |
edbcc1fd | 1072 | } |
97ebebbc LP |
1073 | |
1074 | int dns_scope_ifindex(DnsScope *s) { | |
1075 | assert(s); | |
1076 | ||
1077 | if (s->link) | |
1078 | return s->link->ifindex; | |
1079 | ||
1080 | return 0; | |
1081 | } | |
53fda2bb DR |
1082 | |
1083 | static int on_announcement_timeout(sd_event_source *s, usec_t usec, void *userdata) { | |
1084 | DnsScope *scope = userdata; | |
1085 | ||
1086 | assert(s); | |
1087 | ||
1088 | scope->announce_event_source = sd_event_source_unref(scope->announce_event_source); | |
1089 | ||
1a63fc54 | 1090 | (void) dns_scope_announce(scope, false); |
53fda2bb DR |
1091 | return 0; |
1092 | } | |
1093 | ||
1a63fc54 | 1094 | int dns_scope_announce(DnsScope *scope, bool goodbye) { |
53fda2bb DR |
1095 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
1096 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
a2bf8a19 DR |
1097 | _cleanup_set_free_ Set *types = NULL; |
1098 | DnsTransaction *t; | |
400f54fb | 1099 | DnsZoneItem *z, *i; |
a2bf8a19 DR |
1100 | unsigned size = 0; |
1101 | Iterator iterator; | |
1102 | char *service_type; | |
53fda2bb DR |
1103 | int r; |
1104 | ||
1105 | if (!scope) | |
1a63fc54 | 1106 | return 0; |
53fda2bb DR |
1107 | |
1108 | if (scope->protocol != DNS_PROTOCOL_MDNS) | |
1a63fc54 | 1109 | return 0; |
53fda2bb | 1110 | |
a2bf8a19 DR |
1111 | /* Check if we're done with probing. */ |
1112 | LIST_FOREACH(transactions_by_scope, t, scope->transactions) | |
1113 | if (DNS_TRANSACTION_IS_LIVE(t->state)) | |
1114 | return 0; | |
1115 | ||
e7c1b0e4 DR |
1116 | /* Check if there're services pending conflict resolution. */ |
1117 | if (manager_next_dnssd_names(scope->manager)) | |
1118 | return 0; /* we reach this point only if changing hostname didn't help */ | |
1119 | ||
a2bf8a19 DR |
1120 | /* Calculate answer's size. */ |
1121 | HASHMAP_FOREACH(z, scope->zone.by_key, iterator) { | |
1122 | if (z->state != DNS_ZONE_ITEM_ESTABLISHED) | |
1123 | continue; | |
1124 | ||
1125 | if (z->rr->key->type == DNS_TYPE_PTR && | |
1126 | !dns_zone_contains_name(&scope->zone, z->rr->ptr.name)) { | |
1127 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; | |
1128 | ||
1129 | log_debug("Skip PTR RR <%s> since its counterparts seem to be withdrawn", dns_resource_key_to_string(z->rr->key, key_str, sizeof key_str)); | |
1130 | z->state = DNS_ZONE_ITEM_WITHDRAWN; | |
1131 | continue; | |
1132 | } | |
1133 | ||
1134 | /* Collect service types for _services._dns-sd._udp.local RRs in a set */ | |
1135 | if (!scope->announced && | |
1136 | dns_resource_key_is_dnssd_ptr(z->rr->key)) { | |
1137 | if (!set_contains(types, dns_resource_key_name(z->rr->key))) { | |
1138 | r = set_ensure_allocated(&types, &dns_name_hash_ops); | |
1139 | if (r < 0) | |
1140 | return log_debug_errno(r, "Failed to allocate set: %m"); | |
1141 | ||
1142 | r = set_put(types, dns_resource_key_name(z->rr->key)); | |
1143 | if (r < 0) | |
1144 | return log_debug_errno(r, "Failed to add item to set: %m"); | |
1145 | } | |
1146 | } | |
1147 | ||
400f54fb DR |
1148 | LIST_FOREACH(by_key, i, z) |
1149 | size++; | |
a2bf8a19 DR |
1150 | } |
1151 | ||
1152 | answer = dns_answer_new(size + set_size(types)); | |
1a63fc54 LP |
1153 | if (!answer) |
1154 | return log_oom(); | |
1155 | ||
a2bf8a19 | 1156 | /* Second iteration, actually add RRs to the answer. */ |
400f54fb DR |
1157 | HASHMAP_FOREACH(z, scope->zone.by_key, iterator) |
1158 | LIST_FOREACH (by_key, i, z) { | |
1159 | DnsAnswerFlags flags; | |
a2bf8a19 | 1160 | |
400f54fb DR |
1161 | if (i->state != DNS_ZONE_ITEM_ESTABLISHED) |
1162 | continue; | |
a2bf8a19 | 1163 | |
400f54fb DR |
1164 | if (dns_resource_key_is_dnssd_ptr(i->rr->key)) |
1165 | flags = goodbye ? DNS_ANSWER_GOODBYE : 0; | |
1166 | else | |
1167 | flags = goodbye ? (DNS_ANSWER_GOODBYE|DNS_ANSWER_CACHE_FLUSH) : DNS_ANSWER_CACHE_FLUSH; | |
a2bf8a19 | 1168 | |
400f54fb DR |
1169 | r = dns_answer_add(answer, i->rr, 0 , flags); |
1170 | if (r < 0) | |
1171 | return log_debug_errno(r, "Failed to add RR to announce: %m"); | |
1172 | } | |
a2bf8a19 DR |
1173 | |
1174 | /* Since all the active services are in the zone make them discoverable now. */ | |
1175 | SET_FOREACH(service_type, types, iterator) { | |
1176 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr; | |
1177 | ||
1178 | rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, | |
1179 | "_services._dns-sd._udp.local"); | |
1180 | rr->ptr.name = strdup(service_type); | |
1181 | rr->ttl = MDNS_DEFAULT_TTL; | |
1182 | ||
1183 | r = dns_zone_put(&scope->zone, scope, rr, false); | |
1a63fc54 | 1184 | if (r < 0) |
a2bf8a19 | 1185 | log_warning_errno(r, "Failed to add DNS-SD PTR record to MDNS zone: %m"); |
1a63fc54 | 1186 | |
a2bf8a19 | 1187 | r = dns_answer_add(answer, rr, 0 , 0); |
1a63fc54 | 1188 | if (r < 0) |
a2bf8a19 | 1189 | return log_debug_errno(r, "Failed to add RR to announce: %m"); |
53fda2bb DR |
1190 | } |
1191 | ||
1192 | if (dns_answer_isempty(answer)) | |
1a63fc54 | 1193 | return 0; |
53fda2bb DR |
1194 | |
1195 | r = dns_scope_make_reply_packet(scope, 0, DNS_RCODE_SUCCESS, NULL, answer, NULL, false, &p); | |
1a63fc54 LP |
1196 | if (r < 0) |
1197 | return log_debug_errno(r, "Failed to build reply packet: %m"); | |
1198 | ||
53fda2bb | 1199 | r = dns_scope_emit_udp(scope, -1, p); |
1a63fc54 LP |
1200 | if (r < 0) |
1201 | return log_debug_errno(r, "Failed to send reply packet: %m"); | |
53fda2bb DR |
1202 | |
1203 | /* In section 8.3 of RFC6762: "The Multicast DNS responder MUST send at least two unsolicited | |
1204 | * responses, one second apart." */ | |
1205 | if (!scope->announced) { | |
1206 | usec_t ts; | |
1207 | ||
1208 | scope->announced = true; | |
1209 | ||
1210 | assert_se(sd_event_now(scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1211 | ts += MDNS_ANNOUNCE_DELAY; | |
1212 | ||
1213 | r = sd_event_add_time( | |
1214 | scope->manager->event, | |
1215 | &scope->announce_event_source, | |
1216 | clock_boottime_or_monotonic(), | |
1217 | ts, | |
1218 | MDNS_JITTER_RANGE_USEC, | |
1219 | on_announcement_timeout, scope); | |
1220 | if (r < 0) | |
1a63fc54 | 1221 | return log_debug_errno(r, "Failed to schedule second announcement: %m"); |
19fee3ef LP |
1222 | |
1223 | (void) sd_event_source_set_description(scope->announce_event_source, "mdns-announce"); | |
53fda2bb | 1224 | } |
1a63fc54 LP |
1225 | |
1226 | return 0; | |
53fda2bb | 1227 | } |
6db6a464 DR |
1228 | |
1229 | int dns_scope_add_dnssd_services(DnsScope *scope) { | |
1230 | Iterator i; | |
1231 | DnssdService *service; | |
400f54fb | 1232 | DnssdTxtData *txt_data; |
6db6a464 DR |
1233 | int r; |
1234 | ||
1235 | assert(scope); | |
1236 | ||
1237 | if (hashmap_size(scope->manager->dnssd_services) == 0) | |
1238 | return 0; | |
1239 | ||
1240 | scope->announced = false; | |
1241 | ||
1242 | HASHMAP_FOREACH(service, scope->manager->dnssd_services, i) { | |
c3036641 DR |
1243 | service->withdrawn = false; |
1244 | ||
6db6a464 DR |
1245 | r = dns_zone_put(&scope->zone, scope, service->ptr_rr, false); |
1246 | if (r < 0) | |
1247 | log_warning_errno(r, "Failed to add PTR record to MDNS zone: %m"); | |
1248 | ||
1249 | r = dns_zone_put(&scope->zone, scope, service->srv_rr, true); | |
1250 | if (r < 0) | |
1251 | log_warning_errno(r, "Failed to add SRV record to MDNS zone: %m"); | |
1252 | ||
400f54fb DR |
1253 | LIST_FOREACH(items, txt_data, service->txt_data_items) { |
1254 | r = dns_zone_put(&scope->zone, scope, txt_data->rr, true); | |
1255 | if (r < 0) | |
1256 | log_warning_errno(r, "Failed to add TXT record to MDNS zone: %m"); | |
1257 | } | |
6db6a464 DR |
1258 | } |
1259 | ||
1260 | return 0; | |
1261 | } | |
1262 | ||
1263 | int dns_scope_remove_dnssd_services(DnsScope *scope) { | |
1264 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
1265 | Iterator i; | |
1266 | DnssdService *service; | |
400f54fb | 1267 | DnssdTxtData *txt_data; |
6db6a464 DR |
1268 | int r; |
1269 | ||
1270 | assert(scope); | |
1271 | ||
1272 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_PTR, | |
1273 | "_services._dns-sd._udp.local"); | |
1274 | if (!key) | |
1275 | return log_oom(); | |
1276 | ||
1277 | r = dns_zone_remove_rrs_by_key(&scope->zone, key); | |
1278 | if (r < 0) | |
1279 | return r; | |
1280 | ||
1281 | HASHMAP_FOREACH(service, scope->manager->dnssd_services, i) { | |
1282 | dns_zone_remove_rr(&scope->zone, service->ptr_rr); | |
1283 | dns_zone_remove_rr(&scope->zone, service->srv_rr); | |
400f54fb DR |
1284 | LIST_FOREACH(items, txt_data, service->txt_data_items) |
1285 | dns_zone_remove_rr(&scope->zone, txt_data->rr); | |
6db6a464 DR |
1286 | } |
1287 | ||
1288 | return 0; | |
1289 | } |