]>
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 | |
74b2466e LP |
6 | ***/ |
7 | ||
ad867662 LP |
8 | #include <netinet/tcp.h> |
9 | ||
46f08bea | 10 | #include "af-list.h" |
b5efdb8a | 11 | #include "alloc-util.h" |
4ad7f276 | 12 | #include "dns-domain.h" |
3ffd4af2 LP |
13 | #include "fd-util.h" |
14 | #include "hostname-util.h" | |
15 | #include "missing.h" | |
16 | #include "random-util.h" | |
6db6a464 | 17 | #include "resolved-dnssd.h" |
74b2466e | 18 | #include "resolved-dns-scope.h" |
a2bf8a19 | 19 | #include "resolved-dns-zone.h" |
3ffd4af2 | 20 | #include "resolved-llmnr.h" |
b4f1862d | 21 | #include "resolved-mdns.h" |
3ffd4af2 LP |
22 | #include "socket-util.h" |
23 | #include "strv.h" | |
74b2466e | 24 | |
aea2429d LP |
25 | #define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC) |
26 | #define MULTICAST_RATELIMIT_BURST 1000 | |
27 | ||
9df3ba6c TG |
28 | /* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */ |
29 | #define MULTICAST_RESEND_TIMEOUT_MIN_USEC (100 * USEC_PER_MSEC) | |
30 | #define MULTICAST_RESEND_TIMEOUT_MAX_USEC (1 * USEC_PER_SEC) | |
31 | ||
0dd25fb9 | 32 | int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int family) { |
74b2466e LP |
33 | DnsScope *s; |
34 | ||
35 | assert(m); | |
36 | assert(ret); | |
37 | ||
38 | s = new0(DnsScope, 1); | |
39 | if (!s) | |
40 | return -ENOMEM; | |
41 | ||
42 | s->manager = m; | |
1716f6dc LP |
43 | s->link = l; |
44 | s->protocol = protocol; | |
45 | s->family = family; | |
9df3ba6c | 46 | s->resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC; |
74b2466e | 47 | |
ad6c0475 LP |
48 | if (protocol == DNS_PROTOCOL_DNS) { |
49 | /* Copy DNSSEC mode from the link if it is set there, | |
50 | * otherwise take the manager's DNSSEC mode. Note that | |
51 | * we copy this only at scope creation time, and do | |
52 | * not update it from the on, even if the setting | |
53 | * changes. */ | |
54 | ||
d050561a | 55 | if (l) { |
c69fa7e3 | 56 | s->dnssec_mode = link_get_dnssec_mode(l); |
d050561a IT |
57 | s->private_dns_mode = link_get_private_dns_mode(l); |
58 | } else { | |
c69fa7e3 | 59 | s->dnssec_mode = manager_get_dnssec_mode(m); |
d050561a IT |
60 | s->private_dns_mode = manager_get_private_dns_mode(m); |
61 | } | |
5d67a7ae | 62 | |
5d67a7ae | 63 | } else { |
658f7f02 | 64 | s->dnssec_mode = DNSSEC_NO; |
5d67a7ae IT |
65 | s->private_dns_mode = PRIVATE_DNS_NO; |
66 | } | |
ad6c0475 | 67 | |
74b2466e LP |
68 | LIST_PREPEND(scopes, m->dns_scopes, s); |
69 | ||
1716f6dc | 70 | dns_scope_llmnr_membership(s, true); |
0db4c90a | 71 | dns_scope_mdns_membership(s, true); |
1716f6dc | 72 | |
46f08bea | 73 | 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 | 74 | |
aea2429d LP |
75 | /* Enforce ratelimiting for the multicast protocols */ |
76 | RATELIMIT_INIT(s->ratelimit, MULTICAST_RATELIMIT_INTERVAL_USEC, MULTICAST_RATELIMIT_BURST); | |
77 | ||
74b2466e LP |
78 | *ret = s; |
79 | return 0; | |
80 | } | |
81 | ||
801ad6a6 | 82 | static void dns_scope_abort_transactions(DnsScope *s) { |
801ad6a6 | 83 | assert(s); |
1716f6dc | 84 | |
f9ebb22a LP |
85 | while (s->transactions) { |
86 | DnsTransaction *t = s->transactions; | |
87 | ||
faa133f3 LP |
88 | /* Abort the transaction, but make sure it is not |
89 | * freed while we still look at it */ | |
74b2466e | 90 | |
faa133f3 | 91 | t->block_gc++; |
f4e38037 LP |
92 | if (DNS_TRANSACTION_IS_LIVE(t->state)) |
93 | dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); | |
faa133f3 | 94 | t->block_gc--; |
74b2466e | 95 | |
ec2c5e43 | 96 | dns_transaction_free(t); |
74b2466e | 97 | } |
801ad6a6 LP |
98 | } |
99 | ||
100 | DnsScope* dns_scope_free(DnsScope *s) { | |
801ad6a6 LP |
101 | if (!s) |
102 | return NULL; | |
103 | ||
104 | 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)); | |
105 | ||
106 | dns_scope_llmnr_membership(s, false); | |
0db4c90a | 107 | dns_scope_mdns_membership(s, false); |
801ad6a6 LP |
108 | dns_scope_abort_transactions(s); |
109 | ||
110 | while (s->query_candidates) | |
111 | dns_query_candidate_free(s->query_candidates); | |
74b2466e | 112 | |
f9ebb22a | 113 | hashmap_free(s->transactions_by_key); |
da0c630e | 114 | |
224b0e7a | 115 | ordered_hashmap_free_with_destructor(s->conflict_queue, dns_resource_record_unref); |
a4076574 LP |
116 | sd_event_source_unref(s->conflict_event_source); |
117 | ||
53fda2bb DR |
118 | sd_event_source_unref(s->announce_event_source); |
119 | ||
322345fd | 120 | dns_cache_flush(&s->cache); |
623a4c97 | 121 | dns_zone_flush(&s->zone); |
322345fd | 122 | |
74b2466e | 123 | LIST_REMOVE(scopes, s->manager->dns_scopes, s); |
6b430fdb | 124 | return mfree(s); |
74b2466e LP |
125 | } |
126 | ||
2c27fbca | 127 | DnsServer *dns_scope_get_dns_server(DnsScope *s) { |
74b2466e LP |
128 | assert(s); |
129 | ||
1716f6dc LP |
130 | if (s->protocol != DNS_PROTOCOL_DNS) |
131 | return NULL; | |
132 | ||
74b2466e LP |
133 | if (s->link) |
134 | return link_get_dns_server(s->link); | |
135 | else | |
136 | return manager_get_dns_server(s->manager); | |
137 | } | |
138 | ||
44db02d0 LP |
139 | unsigned dns_scope_get_n_dns_servers(DnsScope *s) { |
140 | unsigned n = 0; | |
141 | DnsServer *i; | |
142 | ||
143 | assert(s); | |
144 | ||
145 | if (s->protocol != DNS_PROTOCOL_DNS) | |
146 | return 0; | |
147 | ||
148 | if (s->link) | |
149 | i = s->link->dns_servers; | |
150 | else | |
151 | i = s->manager->dns_servers; | |
152 | ||
153 | for (; i; i = i->servers_next) | |
154 | n++; | |
155 | ||
156 | return n; | |
157 | } | |
158 | ||
74b2466e LP |
159 | void dns_scope_next_dns_server(DnsScope *s) { |
160 | assert(s); | |
161 | ||
1716f6dc LP |
162 | if (s->protocol != DNS_PROTOCOL_DNS) |
163 | return; | |
164 | ||
74b2466e LP |
165 | if (s->link) |
166 | link_next_dns_server(s->link); | |
167 | else | |
168 | manager_next_dns_server(s->manager); | |
169 | } | |
170 | ||
9df3ba6c TG |
171 | void dns_scope_packet_received(DnsScope *s, usec_t rtt) { |
172 | assert(s); | |
173 | ||
84129d46 LP |
174 | if (rtt <= s->max_rtt) |
175 | return; | |
176 | ||
177 | s->max_rtt = rtt; | |
178 | s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
9df3ba6c TG |
179 | } |
180 | ||
181 | void dns_scope_packet_lost(DnsScope *s, usec_t usec) { | |
182 | assert(s); | |
183 | ||
184 | if (s->resend_timeout <= usec) | |
185 | s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
186 | } | |
187 | ||
519ef046 | 188 | static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) { |
1716f6dc LP |
189 | union in_addr_union addr; |
190 | int ifindex = 0, r; | |
0dd25fb9 | 191 | int family; |
1716f6dc | 192 | uint32_t mtu; |
74b2466e LP |
193 | |
194 | assert(s); | |
195 | assert(p); | |
1716f6dc | 196 | assert(p->protocol == s->protocol); |
ad867662 LP |
197 | |
198 | if (s->link) { | |
1716f6dc | 199 | mtu = s->link->mtu; |
74b2466e | 200 | ifindex = s->link->ifindex; |
1716f6dc | 201 | } else |
e1c95994 | 202 | mtu = manager_find_mtu(s->manager); |
74b2466e | 203 | |
106784eb | 204 | switch (s->protocol) { |
519ef046 | 205 | |
106784eb | 206 | case DNS_PROTOCOL_DNS: |
519ef046 | 207 | assert(fd >= 0); |
9c5e12a4 | 208 | |
623a4c97 | 209 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 210 | return -EOPNOTSUPP; |
623a4c97 | 211 | |
1716f6dc LP |
212 | if (p->size > DNS_PACKET_UNICAST_SIZE_MAX) |
213 | return -EMSGSIZE; | |
214 | ||
a0166609 | 215 | if (p->size + UDP_PACKET_HEADER_SIZE > mtu) |
1716f6dc LP |
216 | return -EMSGSIZE; |
217 | ||
72290734 TG |
218 | r = manager_write(s->manager, fd, p); |
219 | if (r < 0) | |
220 | return r; | |
221 | ||
106784eb | 222 | break; |
1716f6dc | 223 | |
106784eb | 224 | case DNS_PROTOCOL_LLMNR: |
519ef046 LP |
225 | assert(fd < 0); |
226 | ||
1716f6dc | 227 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 228 | return -EOPNOTSUPP; |
1716f6dc | 229 | |
7994ac1d | 230 | if (!ratelimit_below(&s->ratelimit)) |
aea2429d LP |
231 | return -EBUSY; |
232 | ||
1716f6dc | 233 | family = s->family; |
1716f6dc LP |
234 | |
235 | if (family == AF_INET) { | |
236 | addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; | |
1716f6dc LP |
237 | fd = manager_llmnr_ipv4_udp_fd(s->manager); |
238 | } else if (family == AF_INET6) { | |
239 | addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS; | |
240 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
1716f6dc LP |
241 | } else |
242 | return -EAFNOSUPPORT; | |
243 | if (fd < 0) | |
244 | return fd; | |
72290734 | 245 | |
b30bf55d | 246 | r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, NULL, p); |
b4f1862d DM |
247 | if (r < 0) |
248 | return r; | |
249 | ||
250 | break; | |
251 | ||
252 | case DNS_PROTOCOL_MDNS: | |
519ef046 LP |
253 | assert(fd < 0); |
254 | ||
7994ac1d | 255 | if (!ratelimit_below(&s->ratelimit)) |
b4f1862d DM |
256 | return -EBUSY; |
257 | ||
258 | family = s->family; | |
259 | ||
260 | if (family == AF_INET) { | |
261 | addr.in = MDNS_MULTICAST_IPV4_ADDRESS; | |
262 | fd = manager_mdns_ipv4_fd(s->manager); | |
263 | } else if (family == AF_INET6) { | |
264 | addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS; | |
265 | fd = manager_mdns_ipv6_fd(s->manager); | |
266 | } else | |
267 | return -EAFNOSUPPORT; | |
268 | if (fd < 0) | |
269 | return fd; | |
270 | ||
b30bf55d | 271 | r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, NULL, p); |
72290734 TG |
272 | if (r < 0) |
273 | return r; | |
106784eb DM |
274 | |
275 | break; | |
276 | ||
277 | default: | |
74b2466e | 278 | return -EAFNOSUPPORT; |
106784eb | 279 | } |
74b2466e | 280 | |
74b2466e LP |
281 | return 1; |
282 | } | |
283 | ||
519ef046 | 284 | int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) { |
80a62095 DM |
285 | int r; |
286 | ||
287 | assert(s); | |
288 | assert(p); | |
289 | assert(p->protocol == s->protocol); | |
519ef046 | 290 | assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0)); |
80a62095 DM |
291 | |
292 | do { | |
293 | /* If there are multiple linked packets, set the TC bit in all but the last of them */ | |
294 | if (p->more) { | |
295 | assert(p->protocol == DNS_PROTOCOL_MDNS); | |
261f3673 | 296 | dns_packet_set_flags(p, true, true); |
80a62095 DM |
297 | } |
298 | ||
519ef046 | 299 | r = dns_scope_emit_one(s, fd, p); |
80a62095 DM |
300 | if (r < 0) |
301 | return r; | |
302 | ||
303 | p = p->more; | |
519ef046 | 304 | } while (p); |
80a62095 DM |
305 | |
306 | return 0; | |
307 | } | |
308 | ||
519ef046 LP |
309 | static int dns_scope_socket( |
310 | DnsScope *s, | |
311 | int type, | |
312 | int family, | |
313 | const union in_addr_union *address, | |
314 | DnsServer *server, | |
91ccab1e IT |
315 | uint16_t port, |
316 | union sockaddr_union *ret_socket_address) { | |
519ef046 | 317 | |
ad867662 | 318 | _cleanup_close_ int fd = -1; |
91ccab1e | 319 | union sockaddr_union sa; |
ad867662 | 320 | socklen_t salen; |
623a4c97 | 321 | static const int one = 1; |
c10d6bdb | 322 | int r, ifindex; |
ad867662 LP |
323 | |
324 | assert(s); | |
be808ea0 | 325 | |
519ef046 LP |
326 | if (server) { |
327 | assert(family == AF_UNSPEC); | |
328 | assert(!address); | |
be808ea0 | 329 | |
2817157b LP |
330 | ifindex = dns_server_ifindex(server); |
331 | ||
519ef046 LP |
332 | sa.sa.sa_family = server->family; |
333 | if (server->family == AF_INET) { | |
623a4c97 | 334 | sa.in.sin_port = htobe16(port); |
519ef046 | 335 | sa.in.sin_addr = server->address.in; |
623a4c97 | 336 | salen = sizeof(sa.in); |
519ef046 | 337 | } else if (server->family == AF_INET6) { |
623a4c97 | 338 | sa.in6.sin6_port = htobe16(port); |
519ef046 | 339 | sa.in6.sin6_addr = server->address.in6; |
2817157b | 340 | sa.in6.sin6_scope_id = ifindex; |
623a4c97 LP |
341 | salen = sizeof(sa.in6); |
342 | } else | |
343 | return -EAFNOSUPPORT; | |
344 | } else { | |
519ef046 LP |
345 | assert(family != AF_UNSPEC); |
346 | assert(address); | |
347 | ||
623a4c97 | 348 | sa.sa.sa_family = family; |
2817157b | 349 | ifindex = s->link ? s->link->ifindex : 0; |
623a4c97 LP |
350 | |
351 | if (family == AF_INET) { | |
352 | sa.in.sin_port = htobe16(port); | |
353 | sa.in.sin_addr = address->in; | |
354 | salen = sizeof(sa.in); | |
355 | } else if (family == AF_INET6) { | |
356 | sa.in6.sin6_port = htobe16(port); | |
357 | sa.in6.sin6_addr = address->in6; | |
2817157b | 358 | sa.in6.sin6_scope_id = ifindex; |
623a4c97 LP |
359 | salen = sizeof(sa.in6); |
360 | } else | |
361 | return -EAFNOSUPPORT; | |
362 | } | |
ad867662 | 363 | |
0db64366 | 364 | fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
ad867662 LP |
365 | if (fd < 0) |
366 | return -errno; | |
367 | ||
0db64366 TG |
368 | if (type == SOCK_STREAM) { |
369 | r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); | |
370 | if (r < 0) | |
371 | return -errno; | |
372 | } | |
623a4c97 LP |
373 | |
374 | if (s->link) { | |
2817157b | 375 | be32_t ifindex_be = htobe32(ifindex); |
623a4c97 LP |
376 | |
377 | if (sa.sa.sa_family == AF_INET) { | |
2817157b | 378 | r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
379 | if (r < 0) |
380 | return -errno; | |
381 | } else if (sa.sa.sa_family == AF_INET6) { | |
2817157b | 382 | r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
383 | if (r < 0) |
384 | return -errno; | |
385 | } | |
386 | } | |
387 | ||
388 | if (s->protocol == DNS_PROTOCOL_LLMNR) { | |
bf3f1271 | 389 | /* RFC 4795, section 2.5 requires the TTL to be set to 1 */ |
623a4c97 LP |
390 | |
391 | if (sa.sa.sa_family == AF_INET) { | |
392 | r = setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); | |
393 | if (r < 0) | |
394 | return -errno; | |
395 | } else if (sa.sa.sa_family == AF_INET6) { | |
396 | r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); | |
397 | if (r < 0) | |
398 | return -errno; | |
399 | } | |
400 | } | |
ad867662 | 401 | |
91ccab1e IT |
402 | if (ret_socket_address) |
403 | *ret_socket_address = sa; | |
404 | else { | |
405 | r = connect(fd, &sa.sa, salen); | |
406 | if (r < 0 && errno != EINPROGRESS) | |
407 | return -errno; | |
408 | } | |
ad867662 | 409 | |
c10d6bdb | 410 | return TAKE_FD(fd); |
ad867662 LP |
411 | } |
412 | ||
519ef046 | 413 | int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) { |
91ccab1e | 414 | return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port, NULL); |
0db64366 TG |
415 | } |
416 | ||
91ccab1e IT |
417 | int dns_scope_socket_tcp(DnsScope *s, int family, const union in_addr_union *address, DnsServer *server, uint16_t port, union sockaddr_union *ret_socket_address) { |
418 | /* If ret_socket_address is not NULL, the caller is responisble | |
419 | * for calling connect() or sendmsg(). This is required by TCP | |
420 | * Fast Open, to be able to send the initial SYN packet along | |
421 | * with the first data packet. */ | |
422 | return dns_scope_socket(s, SOCK_STREAM, family, address, server, port, ret_socket_address); | |
0db64366 TG |
423 | } |
424 | ||
51323288 | 425 | DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) { |
a51c1048 | 426 | DnsSearchDomain *d; |
74b2466e LP |
427 | |
428 | assert(s); | |
429 | assert(domain); | |
430 | ||
28b9b764 LP |
431 | /* Checks if the specified domain is something to look up on |
432 | * this scope. Note that this accepts non-qualified hostnames, | |
433 | * i.e. those without any search path prefixed yet. */ | |
434 | ||
51323288 LP |
435 | if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex)) |
436 | return DNS_SCOPE_NO; | |
437 | ||
931851e8 | 438 | if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0) |
51323288 LP |
439 | return DNS_SCOPE_NO; |
440 | ||
78c6a153 LP |
441 | /* Never resolve any loopback hostname or IP address via DNS, |
442 | * LLMNR or mDNS. Instead, always rely on synthesized RRs for | |
443 | * these. */ | |
444 | if (is_localhost(domain) || | |
445 | dns_name_endswith(domain, "127.in-addr.arpa") > 0 || | |
9436e8ca LP |
446 | 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) |
447 | return DNS_SCOPE_NO; | |
448 | ||
c9ad0edb LP |
449 | /* Never respond to some of the domains listed in RFC6303 */ |
450 | if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 || | |
451 | dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 || | |
452 | 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) | |
453 | return DNS_SCOPE_NO; | |
454 | ||
7bcffc2e LP |
455 | /* Never respond to some of the domains listed in RFC6761 */ |
456 | if (dns_name_endswith(domain, "invalid") > 0) | |
457 | return DNS_SCOPE_NO; | |
458 | ||
106784eb | 459 | switch (s->protocol) { |
801ad6a6 | 460 | |
613dca46 LP |
461 | case DNS_PROTOCOL_DNS: { |
462 | DnsServer *dns_server; | |
463 | ||
464 | /* Never route things to scopes that lack DNS servers */ | |
465 | dns_server = dns_scope_get_dns_server(s); | |
466 | if (!dns_server) | |
467 | return DNS_SCOPE_NO; | |
468 | ||
469 | /* Always honour search domains for routing queries, except if this scope lacks DNS servers. Note that | |
470 | * we return DNS_SCOPE_YES here, rather than just DNS_SCOPE_MAYBE, which means other wildcard scopes | |
471 | * won't be considered anymore. */ | |
472 | LIST_FOREACH(domains, d, dns_scope_get_search_domains(s)) | |
473 | if (dns_name_endswith(domain, d->name) > 0) | |
474 | return DNS_SCOPE_YES; | |
475 | ||
476 | /* If the DNS server has route-only domains, don't send other requests to it. This would be a privacy | |
477 | * violation, will most probably fail anyway, and adds unnecessary load. */ | |
478 | if (dns_server_limited_domains(dns_server)) | |
479 | return DNS_SCOPE_NO; | |
801ad6a6 | 480 | |
28b9b764 LP |
481 | /* Exclude link-local IP ranges */ |
482 | if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 && | |
c9ad0edb LP |
483 | dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 && |
484 | dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 && | |
485 | dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 && | |
b43d96b0 DM |
486 | dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 && |
487 | /* If networks use .local in their private setups, they are supposed to also add .local to their search | |
488 | * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't | |
489 | * send such queries ordinary DNS servers. */ | |
490 | dns_name_endswith(domain, "local") == 0) | |
faa133f3 | 491 | return DNS_SCOPE_MAYBE; |
1716f6dc | 492 | |
faa133f3 | 493 | return DNS_SCOPE_NO; |
613dca46 | 494 | } |
1716f6dc | 495 | |
106784eb | 496 | case DNS_PROTOCOL_MDNS: |
78c6a153 LP |
497 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
498 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || | |
499 | (dns_name_endswith(domain, "local") > 0 && /* only resolve names ending in .local via mDNS */ | |
500 | dns_name_equal(domain, "local") == 0 && /* but not the single-label "local" name itself */ | |
501 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via mDNS */ | |
d8b7e75f | 502 | return DNS_SCOPE_MAYBE; |
74b2466e LP |
503 | |
504 | return DNS_SCOPE_NO; | |
74b2466e | 505 | |
106784eb | 506 | case DNS_PROTOCOL_LLMNR: |
78c6a153 LP |
507 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
508 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || | |
dc477e73 | 509 | (dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */ |
78c6a153 LP |
510 | !is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */ |
511 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */ | |
1716f6dc | 512 | return DNS_SCOPE_MAYBE; |
74b2466e | 513 | |
1716f6dc | 514 | return DNS_SCOPE_NO; |
74b2466e | 515 | |
106784eb DM |
516 | default: |
517 | assert_not_reached("Unknown scope protocol"); | |
518 | } | |
1716f6dc LP |
519 | } |
520 | ||
011696f7 LP |
521 | bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) { |
522 | int key_family; | |
523 | ||
1716f6dc LP |
524 | assert(s); |
525 | assert(key); | |
526 | ||
28b9b764 LP |
527 | /* Check if it makes sense to resolve the specified key on |
528 | * this scope. Note that this call assumes as fully qualified | |
529 | * name, i.e. the search suffixes already appended. */ | |
530 | ||
011696f7 LP |
531 | if (key->class != DNS_CLASS_IN) |
532 | return false; | |
533 | ||
28b9b764 LP |
534 | if (s->protocol == DNS_PROTOCOL_DNS) { |
535 | ||
e5abebab | 536 | /* On classic DNS, looking up non-address RRs is always |
28b9b764 LP |
537 | * fine. (Specifically, we want to permit looking up |
538 | * DNSKEY and DS records on the root and top-level | |
539 | * domains.) */ | |
540 | if (!dns_resource_key_is_address(key)) | |
541 | return true; | |
542 | ||
543 | /* However, we refuse to look up A and AAAA RRs on the | |
544 | * root and single-label domains, under the assumption | |
545 | * that those should be resolved via LLMNR or search | |
546 | * path only, and should not be leaked onto the | |
547 | * internet. */ | |
1c02e7ba ZJS |
548 | return !(dns_name_is_single_label(dns_resource_key_name(key)) || |
549 | dns_name_is_root(dns_resource_key_name(key))); | |
28b9b764 | 550 | } |
1716f6dc LP |
551 | |
552 | /* On mDNS and LLMNR, send A and AAAA queries only on the | |
553 | * respective scopes */ | |
554 | ||
011696f7 LP |
555 | key_family = dns_type_to_af(key->type); |
556 | if (key_family < 0) | |
557 | return true; | |
1716f6dc | 558 | |
011696f7 | 559 | return key_family == s->family; |
1716f6dc LP |
560 | } |
561 | ||
0db4c90a | 562 | static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) { |
1716f6dc LP |
563 | int fd; |
564 | ||
5ba73e9b | 565 | assert(s); |
5ba73e9b LP |
566 | assert(s->link); |
567 | ||
1716f6dc LP |
568 | if (s->family == AF_INET) { |
569 | struct ip_mreqn mreqn = { | |
0db4c90a | 570 | .imr_multiaddr = in, |
1716f6dc LP |
571 | .imr_ifindex = s->link->ifindex, |
572 | }; | |
573 | ||
d37baf40 DR |
574 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
575 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
576 | else | |
577 | fd = manager_mdns_ipv4_fd(s->manager); | |
578 | ||
1716f6dc LP |
579 | if (fd < 0) |
580 | return fd; | |
581 | ||
7b4c2ee7 LP |
582 | /* Always first try to drop membership before we add |
583 | * one. This is necessary on some devices, such as | |
584 | * veth. */ | |
585 | if (b) | |
dc751688 | 586 | (void) setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)); |
7b4c2ee7 | 587 | |
1716f6dc LP |
588 | if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0) |
589 | return -errno; | |
590 | ||
591 | } else if (s->family == AF_INET6) { | |
592 | struct ipv6_mreq mreq = { | |
0db4c90a | 593 | .ipv6mr_multiaddr = in6, |
1716f6dc LP |
594 | .ipv6mr_interface = s->link->ifindex, |
595 | }; | |
596 | ||
d37baf40 DR |
597 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
598 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
599 | else | |
600 | fd = manager_mdns_ipv6_fd(s->manager); | |
601 | ||
1716f6dc LP |
602 | if (fd < 0) |
603 | return fd; | |
604 | ||
7b4c2ee7 | 605 | if (b) |
dc751688 | 606 | (void) setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)); |
7b4c2ee7 | 607 | |
1716f6dc LP |
608 | if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) |
609 | return -errno; | |
610 | } else | |
611 | return -EAFNOSUPPORT; | |
612 | ||
613 | return 0; | |
74b2466e | 614 | } |
623a4c97 | 615 | |
0db4c90a | 616 | int dns_scope_llmnr_membership(DnsScope *s, bool b) { |
f471bc11 | 617 | assert(s); |
0db4c90a DM |
618 | |
619 | if (s->protocol != DNS_PROTOCOL_LLMNR) | |
620 | return 0; | |
621 | ||
622 | return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS); | |
623 | } | |
624 | ||
625 | int dns_scope_mdns_membership(DnsScope *s, bool b) { | |
f471bc11 | 626 | assert(s); |
0db4c90a DM |
627 | |
628 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
629 | return 0; | |
630 | ||
631 | return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS); | |
632 | } | |
633 | ||
3b991089 | 634 | int dns_scope_make_reply_packet( |
ec2c5e43 LP |
635 | DnsScope *s, |
636 | uint16_t id, | |
637 | int rcode, | |
638 | DnsQuestion *q, | |
639 | DnsAnswer *answer, | |
640 | DnsAnswer *soa, | |
641 | bool tentative, | |
642 | DnsPacket **ret) { | |
643 | ||
623a4c97 | 644 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
623a4c97 LP |
645 | int r; |
646 | ||
647 | assert(s); | |
a4076574 | 648 | assert(ret); |
623a4c97 | 649 | |
501e8eb0 LP |
650 | if (dns_question_isempty(q) && |
651 | dns_answer_isempty(answer) && | |
652 | dns_answer_isempty(soa)) | |
623a4c97 LP |
653 | return -EINVAL; |
654 | ||
51027656 | 655 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
623a4c97 LP |
656 | if (r < 0) |
657 | return r; | |
658 | ||
659 | DNS_PACKET_HEADER(p)->id = id; | |
ea917db9 LP |
660 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( |
661 | 1 /* qr */, | |
662 | 0 /* opcode */, | |
663 | 0 /* c */, | |
664 | 0 /* tc */, | |
ec2c5e43 | 665 | tentative, |
ea917db9 LP |
666 | 0 /* (ra) */, |
667 | 0 /* (ad) */, | |
668 | 0 /* (cd) */, | |
669 | rcode)); | |
623a4c97 | 670 | |
f471bc11 LP |
671 | r = dns_packet_append_question(p, q); |
672 | if (r < 0) | |
673 | return r; | |
674 | DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q)); | |
8bf52d3d | 675 | |
f471bc11 LP |
676 | r = dns_packet_append_answer(p, answer); |
677 | if (r < 0) | |
678 | return r; | |
679 | DNS_PACKET_HEADER(p)->ancount = htobe16(dns_answer_size(answer)); | |
8bf52d3d | 680 | |
f471bc11 LP |
681 | r = dns_packet_append_answer(p, soa); |
682 | if (r < 0) | |
683 | return r; | |
684 | DNS_PACKET_HEADER(p)->arcount = htobe16(dns_answer_size(soa)); | |
623a4c97 | 685 | |
1cc6c93a | 686 | *ret = TAKE_PTR(p); |
623a4c97 LP |
687 | |
688 | return 0; | |
689 | } | |
690 | ||
a4076574 | 691 | static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) { |
2a3900d7 LP |
692 | DnsResourceRecord *rr; |
693 | DnsResourceKey *key; | |
a4076574 LP |
694 | |
695 | assert(s); | |
696 | assert(p); | |
697 | ||
2a3900d7 LP |
698 | DNS_QUESTION_FOREACH(key, p->question) |
699 | dns_zone_verify_conflicts(&s->zone, key); | |
700 | ||
701 | DNS_ANSWER_FOREACH(rr, p->answer) | |
702 | dns_zone_verify_conflicts(&s->zone, rr->key); | |
a4076574 LP |
703 | } |
704 | ||
623a4c97 | 705 | void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { |
8bf52d3d | 706 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; |
b30bf55d | 707 | _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; |
5032b16d | 708 | DnsResourceKey *key = NULL; |
ec2c5e43 | 709 | bool tentative = false; |
b30bf55d | 710 | int r; |
623a4c97 LP |
711 | |
712 | assert(s); | |
713 | assert(p); | |
714 | ||
715 | if (p->protocol != DNS_PROTOCOL_LLMNR) | |
716 | return; | |
717 | ||
2442b93d LP |
718 | if (p->ipproto == IPPROTO_UDP) { |
719 | /* Don't accept UDP queries directed to anything but | |
720 | * the LLMNR multicast addresses. See RFC 4795, | |
d076c6f9 | 721 | * section 2.5. */ |
2442b93d LP |
722 | |
723 | if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS)) | |
724 | return; | |
725 | ||
726 | if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS)) | |
727 | return; | |
728 | } | |
729 | ||
623a4c97 LP |
730 | r = dns_packet_extract(p); |
731 | if (r < 0) { | |
b30bf55d | 732 | log_debug_errno(r, "Failed to extract resource records from incoming packet: %m"); |
623a4c97 LP |
733 | return; |
734 | } | |
735 | ||
8b757a38 | 736 | if (DNS_PACKET_LLMNR_C(p)) { |
a4076574 LP |
737 | /* Somebody notified us about a possible conflict */ |
738 | dns_scope_verify_conflicts(s, p); | |
ea917db9 LP |
739 | return; |
740 | } | |
741 | ||
501e8eb0 | 742 | assert(dns_question_size(p->question) == 1); |
5032b16d LP |
743 | key = p->question->keys[0]; |
744 | ||
97ebebbc | 745 | r = dns_zone_lookup(&s->zone, key, 0, &answer, &soa, &tentative); |
623a4c97 | 746 | if (r < 0) { |
da927ba9 | 747 | log_debug_errno(r, "Failed to lookup key: %m"); |
623a4c97 LP |
748 | return; |
749 | } | |
750 | if (r == 0) | |
751 | return; | |
752 | ||
fcf57f9c LP |
753 | if (answer) |
754 | dns_answer_order_by_scope(answer, in_addr_is_link_local(p->family, &p->sender) > 0); | |
af93291c | 755 | |
ec2c5e43 | 756 | r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, tentative, &reply); |
623a4c97 | 757 | if (r < 0) { |
da927ba9 | 758 | log_debug_errno(r, "Failed to build reply packet: %m"); |
623a4c97 LP |
759 | return; |
760 | } | |
761 | ||
b30bf55d | 762 | if (stream) { |
623a4c97 | 763 | r = dns_stream_write_packet(stream, reply); |
b30bf55d LP |
764 | if (r < 0) { |
765 | log_debug_errno(r, "Failed to enqueue reply packet: %m"); | |
766 | return; | |
767 | } | |
768 | ||
769 | /* Let's take an extra reference on this stream, so that it stays around after returning. The reference | |
770 | * will be dangling until the stream is disconnected, and the default completion handler of the stream | |
771 | * will then unref the stream and destroy it */ | |
772 | if (DNS_STREAM_QUEUED(stream)) | |
773 | dns_stream_ref(stream); | |
774 | } else { | |
775 | int fd; | |
776 | ||
7994ac1d | 777 | if (!ratelimit_below(&s->ratelimit)) |
aea2429d LP |
778 | return; |
779 | ||
623a4c97 LP |
780 | if (p->family == AF_INET) |
781 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
782 | else if (p->family == AF_INET6) | |
783 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
784 | else { | |
785 | log_debug("Unknown protocol"); | |
786 | return; | |
787 | } | |
788 | if (fd < 0) { | |
da927ba9 | 789 | log_debug_errno(fd, "Failed to get reply socket: %m"); |
623a4c97 LP |
790 | return; |
791 | } | |
792 | ||
6e068472 LP |
793 | /* Note that we always immediately reply to all LLMNR |
794 | * requests, and do not wait any time, since we | |
795 | * verified uniqueness for all records. Also see RFC | |
796 | * 4795, Section 2.7 */ | |
797 | ||
b30bf55d LP |
798 | r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, NULL, reply); |
799 | if (r < 0) { | |
800 | log_debug_errno(r, "Failed to send reply packet: %m"); | |
801 | return; | |
802 | } | |
623a4c97 LP |
803 | } |
804 | } | |
ec2c5e43 | 805 | |
f52e61da | 806 | DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok) { |
ec2c5e43 LP |
807 | DnsTransaction *t; |
808 | ||
809 | assert(scope); | |
f52e61da | 810 | assert(key); |
ec2c5e43 | 811 | |
da0c630e LP |
812 | /* Try to find an ongoing transaction that is a equal to the |
813 | * specified question */ | |
f9ebb22a | 814 | t = hashmap_get(scope->transactions_by_key, key); |
4a46ed1b LP |
815 | if (!t) |
816 | return NULL; | |
dc4d47e2 | 817 | |
da0c630e LP |
818 | /* Refuse reusing transactions that completed based on cached |
819 | * data instead of a real packet, if that's requested. */ | |
820 | if (!cache_ok && | |
3bbdc31d | 821 | IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) && |
c3bc53e6 | 822 | t->answer_source != DNS_TRANSACTION_NETWORK) |
da0c630e | 823 | return NULL; |
ec2c5e43 | 824 | |
da0c630e | 825 | return t; |
ec2c5e43 | 826 | } |
a4076574 LP |
827 | |
828 | static int dns_scope_make_conflict_packet( | |
829 | DnsScope *s, | |
830 | DnsResourceRecord *rr, | |
831 | DnsPacket **ret) { | |
832 | ||
833 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
834 | int r; | |
835 | ||
836 | assert(s); | |
837 | assert(rr); | |
838 | assert(ret); | |
839 | ||
51027656 | 840 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
a4076574 LP |
841 | if (r < 0) |
842 | return r; | |
843 | ||
844 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( | |
845 | 0 /* qr */, | |
846 | 0 /* opcode */, | |
847 | 1 /* conflict */, | |
848 | 0 /* tc */, | |
849 | 0 /* t */, | |
850 | 0 /* (ra) */, | |
851 | 0 /* (ad) */, | |
852 | 0 /* (cd) */, | |
853 | 0)); | |
fe2dfc8b DM |
854 | |
855 | /* For mDNS, the transaction ID should always be 0 */ | |
856 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
857 | random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t)); | |
858 | ||
a4076574 LP |
859 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); |
860 | DNS_PACKET_HEADER(p)->arcount = htobe16(1); | |
861 | ||
58ab31d5 | 862 | r = dns_packet_append_key(p, rr->key, 0, NULL); |
a4076574 LP |
863 | if (r < 0) |
864 | return r; | |
865 | ||
58ab31d5 | 866 | r = dns_packet_append_rr(p, rr, 0, NULL, NULL); |
a4076574 LP |
867 | if (r < 0) |
868 | return r; | |
869 | ||
1cc6c93a | 870 | *ret = TAKE_PTR(p); |
a4076574 LP |
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 | } |