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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
74b2466e | 2 | |
ad867662 LP |
3 | #include <netinet/tcp.h> |
4 | ||
46f08bea | 5 | #include "af-list.h" |
b5efdb8a | 6 | #include "alloc-util.h" |
4ad7f276 | 7 | #include "dns-domain.h" |
3ffd4af2 LP |
8 | #include "fd-util.h" |
9 | #include "hostname-util.h" | |
f5947a5e | 10 | #include "missing_network.h" |
3ffd4af2 | 11 | #include "random-util.h" |
6db6a464 | 12 | #include "resolved-dnssd.h" |
74b2466e | 13 | #include "resolved-dns-scope.h" |
a2bf8a19 | 14 | #include "resolved-dns-zone.h" |
3ffd4af2 | 15 | #include "resolved-llmnr.h" |
b4f1862d | 16 | #include "resolved-mdns.h" |
3ffd4af2 LP |
17 | #include "socket-util.h" |
18 | #include "strv.h" | |
74b2466e | 19 | |
aea2429d LP |
20 | #define MULTICAST_RATELIMIT_INTERVAL_USEC (1*USEC_PER_SEC) |
21 | #define MULTICAST_RATELIMIT_BURST 1000 | |
22 | ||
9df3ba6c TG |
23 | /* After how much time to repeat LLMNR requests, see RFC 4795 Section 7 */ |
24 | #define MULTICAST_RESEND_TIMEOUT_MIN_USEC (100 * USEC_PER_MSEC) | |
25 | #define MULTICAST_RESEND_TIMEOUT_MAX_USEC (1 * USEC_PER_SEC) | |
26 | ||
0dd25fb9 | 27 | int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int family) { |
74b2466e LP |
28 | DnsScope *s; |
29 | ||
30 | assert(m); | |
31 | assert(ret); | |
32 | ||
9a1bbc66 | 33 | s = new(DnsScope, 1); |
74b2466e LP |
34 | if (!s) |
35 | return -ENOMEM; | |
36 | ||
9a1bbc66 LP |
37 | *s = (DnsScope) { |
38 | .manager = m, | |
39 | .link = l, | |
40 | .protocol = protocol, | |
41 | .family = family, | |
42 | .resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC, | |
43 | }; | |
74b2466e | 44 | |
ad6c0475 LP |
45 | if (protocol == DNS_PROTOCOL_DNS) { |
46 | /* Copy DNSSEC mode from the link if it is set there, | |
47 | * otherwise take the manager's DNSSEC mode. Note that | |
48 | * we copy this only at scope creation time, and do | |
49 | * not update it from the on, even if the setting | |
50 | * changes. */ | |
51 | ||
d050561a | 52 | if (l) { |
c69fa7e3 | 53 | s->dnssec_mode = link_get_dnssec_mode(l); |
c9299be2 | 54 | s->dns_over_tls_mode = link_get_dns_over_tls_mode(l); |
d050561a | 55 | } else { |
c69fa7e3 | 56 | s->dnssec_mode = manager_get_dnssec_mode(m); |
c9299be2 | 57 | s->dns_over_tls_mode = manager_get_dns_over_tls_mode(m); |
d050561a | 58 | } |
5d67a7ae | 59 | |
5d67a7ae | 60 | } else { |
658f7f02 | 61 | s->dnssec_mode = DNSSEC_NO; |
c9299be2 | 62 | s->dns_over_tls_mode = DNS_OVER_TLS_NO; |
5d67a7ae | 63 | } |
ad6c0475 | 64 | |
74b2466e LP |
65 | LIST_PREPEND(scopes, m->dns_scopes, s); |
66 | ||
1716f6dc | 67 | dns_scope_llmnr_membership(s, true); |
0db4c90a | 68 | dns_scope_mdns_membership(s, true); |
1716f6dc | 69 | |
6ff79f76 | 70 | log_debug("New scope on link %s, protocol %s, family %s", l ? l->ifname : "*", dns_protocol_to_string(protocol), family == AF_UNSPEC ? "*" : af_to_name(family)); |
1716f6dc | 71 | |
aea2429d | 72 | /* Enforce ratelimiting for the multicast protocols */ |
8c227e7f | 73 | s->ratelimit = (RateLimit) { MULTICAST_RATELIMIT_INTERVAL_USEC, MULTICAST_RATELIMIT_BURST }; |
aea2429d | 74 | |
74b2466e LP |
75 | *ret = s; |
76 | return 0; | |
77 | } | |
78 | ||
801ad6a6 | 79 | static void dns_scope_abort_transactions(DnsScope *s) { |
801ad6a6 | 80 | assert(s); |
1716f6dc | 81 | |
f9ebb22a LP |
82 | while (s->transactions) { |
83 | DnsTransaction *t = s->transactions; | |
84 | ||
faa133f3 LP |
85 | /* Abort the transaction, but make sure it is not |
86 | * freed while we still look at it */ | |
74b2466e | 87 | |
faa133f3 | 88 | t->block_gc++; |
f4e38037 LP |
89 | if (DNS_TRANSACTION_IS_LIVE(t->state)) |
90 | dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); | |
faa133f3 | 91 | t->block_gc--; |
74b2466e | 92 | |
ec2c5e43 | 93 | dns_transaction_free(t); |
74b2466e | 94 | } |
801ad6a6 LP |
95 | } |
96 | ||
97 | DnsScope* dns_scope_free(DnsScope *s) { | |
801ad6a6 LP |
98 | if (!s) |
99 | return NULL; | |
100 | ||
6ff79f76 | 101 | log_debug("Removing scope on link %s, protocol %s, family %s", s->link ? s->link->ifname : "*", dns_protocol_to_string(s->protocol), s->family == AF_UNSPEC ? "*" : af_to_name(s->family)); |
801ad6a6 LP |
102 | |
103 | dns_scope_llmnr_membership(s, false); | |
0db4c90a | 104 | dns_scope_mdns_membership(s, false); |
801ad6a6 LP |
105 | dns_scope_abort_transactions(s); |
106 | ||
107 | while (s->query_candidates) | |
108 | dns_query_candidate_free(s->query_candidates); | |
74b2466e | 109 | |
f9ebb22a | 110 | hashmap_free(s->transactions_by_key); |
da0c630e | 111 | |
224b0e7a | 112 | ordered_hashmap_free_with_destructor(s->conflict_queue, dns_resource_record_unref); |
a4076574 LP |
113 | sd_event_source_unref(s->conflict_event_source); |
114 | ||
53fda2bb DR |
115 | sd_event_source_unref(s->announce_event_source); |
116 | ||
322345fd | 117 | dns_cache_flush(&s->cache); |
623a4c97 | 118 | dns_zone_flush(&s->zone); |
322345fd | 119 | |
74b2466e | 120 | LIST_REMOVE(scopes, s->manager->dns_scopes, s); |
6b430fdb | 121 | return mfree(s); |
74b2466e LP |
122 | } |
123 | ||
2c27fbca | 124 | DnsServer *dns_scope_get_dns_server(DnsScope *s) { |
74b2466e LP |
125 | assert(s); |
126 | ||
1716f6dc LP |
127 | if (s->protocol != DNS_PROTOCOL_DNS) |
128 | return NULL; | |
129 | ||
74b2466e LP |
130 | if (s->link) |
131 | return link_get_dns_server(s->link); | |
132 | else | |
133 | return manager_get_dns_server(s->manager); | |
134 | } | |
135 | ||
44db02d0 LP |
136 | unsigned dns_scope_get_n_dns_servers(DnsScope *s) { |
137 | unsigned n = 0; | |
138 | DnsServer *i; | |
139 | ||
140 | assert(s); | |
141 | ||
142 | if (s->protocol != DNS_PROTOCOL_DNS) | |
143 | return 0; | |
144 | ||
145 | if (s->link) | |
146 | i = s->link->dns_servers; | |
147 | else | |
148 | i = s->manager->dns_servers; | |
149 | ||
150 | for (; i; i = i->servers_next) | |
151 | n++; | |
152 | ||
153 | return n; | |
154 | } | |
155 | ||
74b2466e LP |
156 | void dns_scope_next_dns_server(DnsScope *s) { |
157 | assert(s); | |
158 | ||
1716f6dc LP |
159 | if (s->protocol != DNS_PROTOCOL_DNS) |
160 | return; | |
161 | ||
74b2466e LP |
162 | if (s->link) |
163 | link_next_dns_server(s->link); | |
164 | else | |
165 | manager_next_dns_server(s->manager); | |
166 | } | |
167 | ||
9df3ba6c TG |
168 | void dns_scope_packet_received(DnsScope *s, usec_t rtt) { |
169 | assert(s); | |
170 | ||
84129d46 LP |
171 | if (rtt <= s->max_rtt) |
172 | return; | |
173 | ||
174 | s->max_rtt = rtt; | |
175 | s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
9df3ba6c TG |
176 | } |
177 | ||
178 | void dns_scope_packet_lost(DnsScope *s, usec_t usec) { | |
179 | assert(s); | |
180 | ||
181 | if (s->resend_timeout <= usec) | |
182 | s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
183 | } | |
184 | ||
519ef046 | 185 | static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) { |
1716f6dc LP |
186 | union in_addr_union addr; |
187 | int ifindex = 0, r; | |
0dd25fb9 | 188 | int family; |
1716f6dc | 189 | uint32_t mtu; |
74b2466e LP |
190 | |
191 | assert(s); | |
192 | assert(p); | |
1716f6dc | 193 | assert(p->protocol == s->protocol); |
ad867662 LP |
194 | |
195 | if (s->link) { | |
1716f6dc | 196 | mtu = s->link->mtu; |
74b2466e | 197 | ifindex = s->link->ifindex; |
1716f6dc | 198 | } else |
e1c95994 | 199 | mtu = manager_find_mtu(s->manager); |
74b2466e | 200 | |
106784eb | 201 | switch (s->protocol) { |
519ef046 | 202 | |
106784eb | 203 | case DNS_PROTOCOL_DNS: |
519ef046 | 204 | assert(fd >= 0); |
9c5e12a4 | 205 | |
623a4c97 | 206 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 207 | return -EOPNOTSUPP; |
623a4c97 | 208 | |
1716f6dc LP |
209 | if (p->size > DNS_PACKET_UNICAST_SIZE_MAX) |
210 | return -EMSGSIZE; | |
211 | ||
a0166609 | 212 | if (p->size + UDP_PACKET_HEADER_SIZE > mtu) |
1716f6dc LP |
213 | return -EMSGSIZE; |
214 | ||
72290734 TG |
215 | r = manager_write(s->manager, fd, p); |
216 | if (r < 0) | |
217 | return r; | |
218 | ||
106784eb | 219 | break; |
1716f6dc | 220 | |
106784eb | 221 | case DNS_PROTOCOL_LLMNR: |
519ef046 LP |
222 | assert(fd < 0); |
223 | ||
1716f6dc | 224 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 225 | return -EOPNOTSUPP; |
1716f6dc | 226 | |
7994ac1d | 227 | if (!ratelimit_below(&s->ratelimit)) |
aea2429d LP |
228 | return -EBUSY; |
229 | ||
1716f6dc | 230 | family = s->family; |
1716f6dc LP |
231 | |
232 | if (family == AF_INET) { | |
233 | addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; | |
1716f6dc LP |
234 | fd = manager_llmnr_ipv4_udp_fd(s->manager); |
235 | } else if (family == AF_INET6) { | |
236 | addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS; | |
237 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
1716f6dc LP |
238 | } else |
239 | return -EAFNOSUPPORT; | |
240 | if (fd < 0) | |
241 | return fd; | |
72290734 | 242 | |
b30bf55d | 243 | r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, NULL, p); |
b4f1862d DM |
244 | if (r < 0) |
245 | return r; | |
246 | ||
247 | break; | |
248 | ||
249 | case DNS_PROTOCOL_MDNS: | |
519ef046 LP |
250 | assert(fd < 0); |
251 | ||
7994ac1d | 252 | if (!ratelimit_below(&s->ratelimit)) |
b4f1862d DM |
253 | return -EBUSY; |
254 | ||
255 | family = s->family; | |
256 | ||
257 | if (family == AF_INET) { | |
258 | addr.in = MDNS_MULTICAST_IPV4_ADDRESS; | |
259 | fd = manager_mdns_ipv4_fd(s->manager); | |
260 | } else if (family == AF_INET6) { | |
261 | addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS; | |
262 | fd = manager_mdns_ipv6_fd(s->manager); | |
263 | } else | |
264 | return -EAFNOSUPPORT; | |
265 | if (fd < 0) | |
266 | return fd; | |
267 | ||
b30bf55d | 268 | r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, NULL, p); |
72290734 TG |
269 | if (r < 0) |
270 | return r; | |
106784eb DM |
271 | |
272 | break; | |
273 | ||
274 | default: | |
74b2466e | 275 | return -EAFNOSUPPORT; |
106784eb | 276 | } |
74b2466e | 277 | |
74b2466e LP |
278 | return 1; |
279 | } | |
280 | ||
519ef046 | 281 | int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) { |
80a62095 DM |
282 | int r; |
283 | ||
284 | assert(s); | |
285 | assert(p); | |
286 | assert(p->protocol == s->protocol); | |
519ef046 | 287 | assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0)); |
80a62095 DM |
288 | |
289 | do { | |
290 | /* If there are multiple linked packets, set the TC bit in all but the last of them */ | |
291 | if (p->more) { | |
292 | assert(p->protocol == DNS_PROTOCOL_MDNS); | |
261f3673 | 293 | dns_packet_set_flags(p, true, true); |
80a62095 DM |
294 | } |
295 | ||
519ef046 | 296 | r = dns_scope_emit_one(s, fd, p); |
80a62095 DM |
297 | if (r < 0) |
298 | return r; | |
299 | ||
300 | p = p->more; | |
519ef046 | 301 | } while (p); |
80a62095 DM |
302 | |
303 | return 0; | |
304 | } | |
305 | ||
519ef046 LP |
306 | static int dns_scope_socket( |
307 | DnsScope *s, | |
308 | int type, | |
309 | int family, | |
310 | const union in_addr_union *address, | |
311 | DnsServer *server, | |
91ccab1e IT |
312 | uint16_t port, |
313 | union sockaddr_union *ret_socket_address) { | |
519ef046 | 314 | |
ad867662 | 315 | _cleanup_close_ int fd = -1; |
91ccab1e | 316 | union sockaddr_union sa; |
ad867662 | 317 | socklen_t salen; |
c10d6bdb | 318 | int r, ifindex; |
ad867662 LP |
319 | |
320 | assert(s); | |
be808ea0 | 321 | |
519ef046 LP |
322 | if (server) { |
323 | assert(family == AF_UNSPEC); | |
324 | assert(!address); | |
be808ea0 | 325 | |
2817157b LP |
326 | ifindex = dns_server_ifindex(server); |
327 | ||
7b3bae21 YW |
328 | switch (server->family) { |
329 | case AF_INET: | |
330 | sa = (union sockaddr_union) { | |
331 | .in.sin_family = server->family, | |
332 | .in.sin_port = htobe16(port), | |
333 | .in.sin_addr = server->address.in, | |
334 | }; | |
623a4c97 | 335 | salen = sizeof(sa.in); |
7b3bae21 YW |
336 | break; |
337 | case AF_INET6: | |
338 | sa = (union sockaddr_union) { | |
339 | .in6.sin6_family = server->family, | |
340 | .in6.sin6_port = htobe16(port), | |
341 | .in6.sin6_addr = server->address.in6, | |
342 | .in6.sin6_scope_id = ifindex, | |
343 | }; | |
623a4c97 | 344 | salen = sizeof(sa.in6); |
7b3bae21 YW |
345 | break; |
346 | default: | |
623a4c97 | 347 | return -EAFNOSUPPORT; |
7b3bae21 | 348 | } |
623a4c97 | 349 | } else { |
519ef046 LP |
350 | assert(family != AF_UNSPEC); |
351 | assert(address); | |
352 | ||
2817157b | 353 | ifindex = s->link ? s->link->ifindex : 0; |
623a4c97 | 354 | |
7b3bae21 YW |
355 | switch (family) { |
356 | case AF_INET: | |
357 | sa = (union sockaddr_union) { | |
358 | .in.sin_family = family, | |
359 | .in.sin_port = htobe16(port), | |
360 | .in.sin_addr = address->in, | |
361 | }; | |
623a4c97 | 362 | salen = sizeof(sa.in); |
7b3bae21 YW |
363 | break; |
364 | case AF_INET6: | |
365 | sa = (union sockaddr_union) { | |
366 | .in6.sin6_family = family, | |
367 | .in6.sin6_port = htobe16(port), | |
368 | .in6.sin6_addr = address->in6, | |
369 | .in6.sin6_scope_id = ifindex, | |
370 | }; | |
623a4c97 | 371 | salen = sizeof(sa.in6); |
7b3bae21 YW |
372 | break; |
373 | default: | |
623a4c97 | 374 | return -EAFNOSUPPORT; |
7b3bae21 | 375 | } |
623a4c97 | 376 | } |
ad867662 | 377 | |
0db64366 | 378 | fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
ad867662 LP |
379 | if (fd < 0) |
380 | return -errno; | |
381 | ||
0db64366 | 382 | if (type == SOCK_STREAM) { |
2ff48e98 | 383 | r = setsockopt_int(fd, IPPROTO_TCP, TCP_NODELAY, true); |
0db64366 | 384 | if (r < 0) |
2ff48e98 | 385 | return r; |
0db64366 | 386 | } |
623a4c97 LP |
387 | |
388 | if (s->link) { | |
2817157b | 389 | be32_t ifindex_be = htobe32(ifindex); |
623a4c97 LP |
390 | |
391 | if (sa.sa.sa_family == AF_INET) { | |
2817157b | 392 | r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
393 | if (r < 0) |
394 | return -errno; | |
395 | } else if (sa.sa.sa_family == AF_INET6) { | |
2817157b | 396 | r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
397 | if (r < 0) |
398 | return -errno; | |
399 | } | |
400 | } | |
401 | ||
402 | if (s->protocol == DNS_PROTOCOL_LLMNR) { | |
bf3f1271 | 403 | /* RFC 4795, section 2.5 requires the TTL to be set to 1 */ |
623a4c97 LP |
404 | |
405 | if (sa.sa.sa_family == AF_INET) { | |
5b496410 | 406 | r = setsockopt_int(fd, IPPROTO_IP, IP_TTL, 1); |
623a4c97 | 407 | if (r < 0) |
2ff48e98 | 408 | return r; |
623a4c97 | 409 | } else if (sa.sa.sa_family == AF_INET6) { |
5b496410 | 410 | r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 1); |
623a4c97 | 411 | if (r < 0) |
2ff48e98 | 412 | return r; |
623a4c97 LP |
413 | } |
414 | } | |
ad867662 | 415 | |
9fcdab9c YW |
416 | if (type == SOCK_DGRAM) { |
417 | /* Set IP_RECVERR or IPV6_RECVERR to get ICMP error feedback. See discussion in #10345. */ | |
c9e69182 LP |
418 | |
419 | if (sa.sa.sa_family == AF_INET) { | |
420 | r = setsockopt_int(fd, IPPROTO_IP, IP_RECVERR, true); | |
421 | if (r < 0) | |
422 | return r; | |
423 | ||
424 | r = setsockopt_int(fd, IPPROTO_IP, IP_PKTINFO, true); | |
425 | if (r < 0) | |
426 | return r; | |
427 | ||
428 | } else if (sa.sa.sa_family == AF_INET6) { | |
429 | r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_RECVERR, true); | |
430 | if (r < 0) | |
431 | return r; | |
432 | ||
433 | r = setsockopt_int(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, true); | |
434 | if (r < 0) | |
435 | return r; | |
436 | } | |
9fcdab9c YW |
437 | } |
438 | ||
91ccab1e IT |
439 | if (ret_socket_address) |
440 | *ret_socket_address = sa; | |
441 | else { | |
442 | r = connect(fd, &sa.sa, salen); | |
443 | if (r < 0 && errno != EINPROGRESS) | |
444 | return -errno; | |
445 | } | |
ad867662 | 446 | |
c10d6bdb | 447 | return TAKE_FD(fd); |
ad867662 LP |
448 | } |
449 | ||
da9de738 YW |
450 | int dns_scope_socket_udp(DnsScope *s, DnsServer *server) { |
451 | return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, dns_server_port(server), NULL); | |
0db64366 TG |
452 | } |
453 | ||
91ccab1e | 454 | 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) { |
5238e957 | 455 | /* If ret_socket_address is not NULL, the caller is responsible |
91ccab1e IT |
456 | * for calling connect() or sendmsg(). This is required by TCP |
457 | * Fast Open, to be able to send the initial SYN packet along | |
458 | * with the first data packet. */ | |
459 | return dns_scope_socket(s, SOCK_STREAM, family, address, server, port, ret_socket_address); | |
0db64366 TG |
460 | } |
461 | ||
17508549 LP |
462 | static DnsScopeMatch accept_link_local_reverse_lookups(const char *domain) { |
463 | assert(domain); | |
464 | ||
465 | if (dns_name_endswith(domain, "254.169.in-addr.arpa") > 0) | |
466 | return DNS_SCOPE_YES_BASE + 4; /* 4 labels match */ | |
467 | ||
468 | if (dns_name_endswith(domain, "8.e.f.ip6.arpa") > 0 || | |
469 | dns_name_endswith(domain, "9.e.f.ip6.arpa") > 0 || | |
470 | dns_name_endswith(domain, "a.e.f.ip6.arpa") > 0 || | |
471 | dns_name_endswith(domain, "b.e.f.ip6.arpa") > 0) | |
472 | return DNS_SCOPE_YES_BASE + 5; /* 5 labels match */ | |
473 | ||
474 | return _DNS_SCOPE_MATCH_INVALID; | |
475 | } | |
476 | ||
a97a3b25 LP |
477 | DnsScopeMatch dns_scope_good_domain( |
478 | DnsScope *s, | |
479 | int ifindex, | |
480 | uint64_t flags, | |
481 | const char *domain) { | |
482 | ||
a51c1048 | 483 | DnsSearchDomain *d; |
74b2466e | 484 | |
a97a3b25 LP |
485 | /* This returns the following return values: |
486 | * | |
487 | * DNS_SCOPE_NO → This scope is not suitable for lookups of this domain, at all | |
488 | * DNS_SCOPE_MAYBE → This scope is suitable, but only if nothing else wants it | |
489 | * DNS_SCOPE_YES_BASE+n → This scope is suitable, and 'n' suffix labels match | |
490 | * | |
491 | * (The idea is that the caller will only use the scopes with the longest 'n' returned. If no scopes return | |
492 | * DNS_SCOPE_YES_BASE+n, then it should use those which returned DNS_SCOPE_MAYBE. It should never use those | |
493 | * which returned DNS_SCOPE_NO.) | |
494 | */ | |
495 | ||
74b2466e LP |
496 | assert(s); |
497 | assert(domain); | |
498 | ||
3d334c40 ZJS |
499 | /* Checks if the specified domain is something to look up on this scope. Note that this accepts |
500 | * non-qualified hostnames, i.e. those without any search path suffixed. */ | |
28b9b764 | 501 | |
51323288 LP |
502 | if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex)) |
503 | return DNS_SCOPE_NO; | |
504 | ||
931851e8 | 505 | if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0) |
51323288 LP |
506 | return DNS_SCOPE_NO; |
507 | ||
78c6a153 LP |
508 | /* Never resolve any loopback hostname or IP address via DNS, |
509 | * LLMNR or mDNS. Instead, always rely on synthesized RRs for | |
510 | * these. */ | |
511 | if (is_localhost(domain) || | |
512 | dns_name_endswith(domain, "127.in-addr.arpa") > 0 || | |
9436e8ca LP |
513 | 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) |
514 | return DNS_SCOPE_NO; | |
515 | ||
c9ad0edb LP |
516 | /* Never respond to some of the domains listed in RFC6303 */ |
517 | if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 || | |
518 | dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 || | |
519 | 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) | |
520 | return DNS_SCOPE_NO; | |
521 | ||
7bcffc2e LP |
522 | /* Never respond to some of the domains listed in RFC6761 */ |
523 | if (dns_name_endswith(domain, "invalid") > 0) | |
524 | return DNS_SCOPE_NO; | |
525 | ||
106784eb | 526 | switch (s->protocol) { |
801ad6a6 | 527 | |
613dca46 | 528 | case DNS_PROTOCOL_DNS: { |
fea46786 | 529 | bool has_search_domains = false; |
a97a3b25 | 530 | int n_best = -1; |
613dca46 LP |
531 | |
532 | /* Never route things to scopes that lack DNS servers */ | |
f76fa088 | 533 | if (!dns_scope_get_dns_server(s)) |
613dca46 LP |
534 | return DNS_SCOPE_NO; |
535 | ||
536 | /* Always honour search domains for routing queries, except if this scope lacks DNS servers. Note that | |
537 | * we return DNS_SCOPE_YES here, rather than just DNS_SCOPE_MAYBE, which means other wildcard scopes | |
538 | * won't be considered anymore. */ | |
fea46786 LP |
539 | LIST_FOREACH(domains, d, dns_scope_get_search_domains(s)) { |
540 | ||
541 | if (!d->route_only && !dns_name_is_root(d->name)) | |
542 | has_search_domains = true; | |
543 | ||
a97a3b25 LP |
544 | if (dns_name_endswith(domain, d->name) > 0) { |
545 | int c; | |
546 | ||
547 | c = dns_name_count_labels(d->name); | |
548 | if (c < 0) | |
549 | continue; | |
550 | ||
551 | if (c > n_best) | |
552 | n_best = c; | |
553 | } | |
fea46786 LP |
554 | } |
555 | ||
556 | /* If there's a true search domain defined for this scope, and the query is single-label, | |
557 | * then let's resolve things here, prefereably. Note that LLMNR considers itself | |
558 | * authoritative for single-label names too, at the same preference, see below. */ | |
559 | if (has_search_domains && dns_name_is_single_label(domain)) | |
560 | return DNS_SCOPE_YES_BASE + 1; | |
a97a3b25 LP |
561 | |
562 | /* Let's return the number of labels in the best matching result */ | |
563 | if (n_best >= 0) { | |
564 | assert(n_best <= DNS_SCOPE_YES_END - DNS_SCOPE_YES_BASE); | |
565 | return DNS_SCOPE_YES_BASE + n_best; | |
566 | } | |
613dca46 | 567 | |
ca5394d2 LP |
568 | /* See if this scope is suitable as default route. */ |
569 | if (!dns_scope_is_default_route(s)) | |
613dca46 | 570 | return DNS_SCOPE_NO; |
801ad6a6 | 571 | |
28b9b764 LP |
572 | /* Exclude link-local IP ranges */ |
573 | if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 && | |
c9ad0edb LP |
574 | dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 && |
575 | dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 && | |
576 | dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 && | |
b43d96b0 DM |
577 | dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 && |
578 | /* If networks use .local in their private setups, they are supposed to also add .local to their search | |
579 | * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't | |
580 | * send such queries ordinary DNS servers. */ | |
581 | dns_name_endswith(domain, "local") == 0) | |
faa133f3 | 582 | return DNS_SCOPE_MAYBE; |
1716f6dc | 583 | |
faa133f3 | 584 | return DNS_SCOPE_NO; |
613dca46 | 585 | } |
1716f6dc | 586 | |
17508549 LP |
587 | case DNS_PROTOCOL_MDNS: { |
588 | DnsScopeMatch m; | |
589 | ||
590 | m = accept_link_local_reverse_lookups(domain); | |
591 | if (m >= 0) | |
592 | return m; | |
593 | ||
78c6a153 | 594 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
17508549 LP |
595 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0)) |
596 | return DNS_SCOPE_MAYBE; | |
597 | ||
598 | if ((dns_name_endswith(domain, "local") > 0 && /* only resolve names ending in .local via mDNS */ | |
78c6a153 LP |
599 | dns_name_equal(domain, "local") == 0 && /* but not the single-label "local" name itself */ |
600 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via mDNS */ | |
17508549 | 601 | return DNS_SCOPE_YES_BASE + 1; /* Return +1, as the top-level .local domain matches, i.e. one label */ |
74b2466e LP |
602 | |
603 | return DNS_SCOPE_NO; | |
17508549 LP |
604 | } |
605 | ||
606 | case DNS_PROTOCOL_LLMNR: { | |
607 | DnsScopeMatch m; | |
608 | ||
609 | m = accept_link_local_reverse_lookups(domain); | |
610 | if (m >= 0) | |
611 | return m; | |
74b2466e | 612 | |
78c6a153 | 613 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
17508549 LP |
614 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0)) |
615 | return DNS_SCOPE_MAYBE; | |
616 | ||
617 | if ((dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */ | |
78c6a153 LP |
618 | !is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */ |
619 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */ | |
fea46786 LP |
620 | return DNS_SCOPE_YES_BASE + 1; /* Return +1, as we consider ourselves authoritative |
621 | * for single-label names, i.e. one label. This is | |
3b5bd7d6 | 622 | * particularly relevant as it means a "." route on some |
fea46786 LP |
623 | * other scope won't pull all traffic away from |
624 | * us. (If people actually want to pull traffic away | |
625 | * from us they should turn off LLMNR on the | |
626 | * link). Note that unicast DNS scopes with search | |
627 | * domains also consider themselves authoritative for | |
628 | * single-label domains, at the same preference (see | |
629 | * above). */ | |
74b2466e | 630 | |
1716f6dc | 631 | return DNS_SCOPE_NO; |
17508549 | 632 | } |
74b2466e | 633 | |
106784eb DM |
634 | default: |
635 | assert_not_reached("Unknown scope protocol"); | |
636 | } | |
1716f6dc LP |
637 | } |
638 | ||
011696f7 LP |
639 | bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) { |
640 | int key_family; | |
641 | ||
1716f6dc LP |
642 | assert(s); |
643 | assert(key); | |
644 | ||
28b9b764 LP |
645 | /* Check if it makes sense to resolve the specified key on |
646 | * this scope. Note that this call assumes as fully qualified | |
647 | * name, i.e. the search suffixes already appended. */ | |
648 | ||
011696f7 LP |
649 | if (key->class != DNS_CLASS_IN) |
650 | return false; | |
651 | ||
28b9b764 LP |
652 | if (s->protocol == DNS_PROTOCOL_DNS) { |
653 | ||
3b5bd7d6 ZJS |
654 | /* On classic DNS, looking up non-address RRs is always fine. (Specifically, we want to |
655 | * permit looking up DNSKEY and DS records on the root and top-level domains.) */ | |
28b9b764 LP |
656 | if (!dns_resource_key_is_address(key)) |
657 | return true; | |
658 | ||
3b5bd7d6 ZJS |
659 | /* Unless explicitly overridden, we refuse to look up A and AAAA RRs on the root and |
660 | * single-label domains, under the assumption that those should be resolved via LLMNR or | |
661 | * search path only, and should not be leaked onto the internet. */ | |
662 | const char* name = dns_resource_key_name(key); | |
663 | ||
664 | if (!s->manager->resolve_unicast_single_label && | |
665 | dns_name_is_single_label(name)) | |
666 | return false; | |
667 | ||
668 | return !dns_name_is_root(name); | |
28b9b764 | 669 | } |
1716f6dc LP |
670 | |
671 | /* On mDNS and LLMNR, send A and AAAA queries only on the | |
672 | * respective scopes */ | |
673 | ||
011696f7 LP |
674 | key_family = dns_type_to_af(key->type); |
675 | if (key_family < 0) | |
676 | return true; | |
1716f6dc | 677 | |
011696f7 | 678 | return key_family == s->family; |
1716f6dc LP |
679 | } |
680 | ||
0db4c90a | 681 | static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) { |
1716f6dc LP |
682 | int fd; |
683 | ||
5ba73e9b | 684 | assert(s); |
5ba73e9b LP |
685 | assert(s->link); |
686 | ||
1716f6dc LP |
687 | if (s->family == AF_INET) { |
688 | struct ip_mreqn mreqn = { | |
0db4c90a | 689 | .imr_multiaddr = in, |
1716f6dc LP |
690 | .imr_ifindex = s->link->ifindex, |
691 | }; | |
692 | ||
d37baf40 DR |
693 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
694 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
695 | else | |
696 | fd = manager_mdns_ipv4_fd(s->manager); | |
697 | ||
1716f6dc LP |
698 | if (fd < 0) |
699 | return fd; | |
700 | ||
7b4c2ee7 LP |
701 | /* Always first try to drop membership before we add |
702 | * one. This is necessary on some devices, such as | |
703 | * veth. */ | |
704 | if (b) | |
dc751688 | 705 | (void) setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)); |
7b4c2ee7 | 706 | |
1716f6dc LP |
707 | if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0) |
708 | return -errno; | |
709 | ||
710 | } else if (s->family == AF_INET6) { | |
711 | struct ipv6_mreq mreq = { | |
0db4c90a | 712 | .ipv6mr_multiaddr = in6, |
1716f6dc LP |
713 | .ipv6mr_interface = s->link->ifindex, |
714 | }; | |
715 | ||
d37baf40 DR |
716 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
717 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
718 | else | |
719 | fd = manager_mdns_ipv6_fd(s->manager); | |
720 | ||
1716f6dc LP |
721 | if (fd < 0) |
722 | return fd; | |
723 | ||
7b4c2ee7 | 724 | if (b) |
dc751688 | 725 | (void) setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)); |
7b4c2ee7 | 726 | |
1716f6dc LP |
727 | if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) |
728 | return -errno; | |
729 | } else | |
730 | return -EAFNOSUPPORT; | |
731 | ||
732 | return 0; | |
74b2466e | 733 | } |
623a4c97 | 734 | |
0db4c90a | 735 | int dns_scope_llmnr_membership(DnsScope *s, bool b) { |
f471bc11 | 736 | assert(s); |
0db4c90a DM |
737 | |
738 | if (s->protocol != DNS_PROTOCOL_LLMNR) | |
739 | return 0; | |
740 | ||
741 | return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS); | |
742 | } | |
743 | ||
744 | int dns_scope_mdns_membership(DnsScope *s, bool b) { | |
f471bc11 | 745 | assert(s); |
0db4c90a DM |
746 | |
747 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
748 | return 0; | |
749 | ||
750 | return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS); | |
751 | } | |
752 | ||
3b991089 | 753 | int dns_scope_make_reply_packet( |
ec2c5e43 LP |
754 | DnsScope *s, |
755 | uint16_t id, | |
756 | int rcode, | |
757 | DnsQuestion *q, | |
758 | DnsAnswer *answer, | |
759 | DnsAnswer *soa, | |
760 | bool tentative, | |
761 | DnsPacket **ret) { | |
762 | ||
623a4c97 | 763 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
623a4c97 LP |
764 | int r; |
765 | ||
766 | assert(s); | |
a4076574 | 767 | assert(ret); |
623a4c97 | 768 | |
501e8eb0 LP |
769 | if (dns_question_isempty(q) && |
770 | dns_answer_isempty(answer) && | |
771 | dns_answer_isempty(soa)) | |
623a4c97 LP |
772 | return -EINVAL; |
773 | ||
51027656 | 774 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
623a4c97 LP |
775 | if (r < 0) |
776 | return r; | |
777 | ||
778 | DNS_PACKET_HEADER(p)->id = id; | |
ea917db9 LP |
779 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( |
780 | 1 /* qr */, | |
781 | 0 /* opcode */, | |
782 | 0 /* c */, | |
783 | 0 /* tc */, | |
ec2c5e43 | 784 | tentative, |
ea917db9 LP |
785 | 0 /* (ra) */, |
786 | 0 /* (ad) */, | |
787 | 0 /* (cd) */, | |
788 | rcode)); | |
623a4c97 | 789 | |
f471bc11 LP |
790 | r = dns_packet_append_question(p, q); |
791 | if (r < 0) | |
792 | return r; | |
793 | DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q)); | |
8bf52d3d | 794 | |
f471bc11 LP |
795 | r = dns_packet_append_answer(p, answer); |
796 | if (r < 0) | |
797 | return r; | |
798 | DNS_PACKET_HEADER(p)->ancount = htobe16(dns_answer_size(answer)); | |
8bf52d3d | 799 | |
f471bc11 LP |
800 | r = dns_packet_append_answer(p, soa); |
801 | if (r < 0) | |
802 | return r; | |
803 | DNS_PACKET_HEADER(p)->arcount = htobe16(dns_answer_size(soa)); | |
623a4c97 | 804 | |
1cc6c93a | 805 | *ret = TAKE_PTR(p); |
623a4c97 LP |
806 | |
807 | return 0; | |
808 | } | |
809 | ||
a4076574 | 810 | static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) { |
2a3900d7 LP |
811 | DnsResourceRecord *rr; |
812 | DnsResourceKey *key; | |
a4076574 LP |
813 | |
814 | assert(s); | |
815 | assert(p); | |
816 | ||
2a3900d7 LP |
817 | DNS_QUESTION_FOREACH(key, p->question) |
818 | dns_zone_verify_conflicts(&s->zone, key); | |
819 | ||
820 | DNS_ANSWER_FOREACH(rr, p->answer) | |
821 | dns_zone_verify_conflicts(&s->zone, rr->key); | |
a4076574 LP |
822 | } |
823 | ||
623a4c97 | 824 | void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { |
8bf52d3d | 825 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; |
b30bf55d | 826 | _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; |
5032b16d | 827 | DnsResourceKey *key = NULL; |
ec2c5e43 | 828 | bool tentative = false; |
b30bf55d | 829 | int r; |
623a4c97 LP |
830 | |
831 | assert(s); | |
832 | assert(p); | |
833 | ||
834 | if (p->protocol != DNS_PROTOCOL_LLMNR) | |
835 | return; | |
836 | ||
2442b93d LP |
837 | if (p->ipproto == IPPROTO_UDP) { |
838 | /* Don't accept UDP queries directed to anything but | |
839 | * the LLMNR multicast addresses. See RFC 4795, | |
d076c6f9 | 840 | * section 2.5. */ |
2442b93d LP |
841 | |
842 | if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS)) | |
843 | return; | |
844 | ||
845 | if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS)) | |
846 | return; | |
847 | } | |
848 | ||
623a4c97 LP |
849 | r = dns_packet_extract(p); |
850 | if (r < 0) { | |
b30bf55d | 851 | log_debug_errno(r, "Failed to extract resource records from incoming packet: %m"); |
623a4c97 LP |
852 | return; |
853 | } | |
854 | ||
8b757a38 | 855 | if (DNS_PACKET_LLMNR_C(p)) { |
a4076574 LP |
856 | /* Somebody notified us about a possible conflict */ |
857 | dns_scope_verify_conflicts(s, p); | |
ea917db9 LP |
858 | return; |
859 | } | |
860 | ||
501e8eb0 | 861 | assert(dns_question_size(p->question) == 1); |
5032b16d LP |
862 | key = p->question->keys[0]; |
863 | ||
97ebebbc | 864 | r = dns_zone_lookup(&s->zone, key, 0, &answer, &soa, &tentative); |
623a4c97 | 865 | if (r < 0) { |
105a1a36 | 866 | log_debug_errno(r, "Failed to look up key: %m"); |
623a4c97 LP |
867 | return; |
868 | } | |
869 | if (r == 0) | |
870 | return; | |
871 | ||
fcf57f9c LP |
872 | if (answer) |
873 | dns_answer_order_by_scope(answer, in_addr_is_link_local(p->family, &p->sender) > 0); | |
af93291c | 874 | |
ec2c5e43 | 875 | r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, tentative, &reply); |
623a4c97 | 876 | if (r < 0) { |
da927ba9 | 877 | log_debug_errno(r, "Failed to build reply packet: %m"); |
623a4c97 LP |
878 | return; |
879 | } | |
880 | ||
b30bf55d | 881 | if (stream) { |
623a4c97 | 882 | r = dns_stream_write_packet(stream, reply); |
b30bf55d LP |
883 | if (r < 0) { |
884 | log_debug_errno(r, "Failed to enqueue reply packet: %m"); | |
885 | return; | |
886 | } | |
887 | ||
888 | /* Let's take an extra reference on this stream, so that it stays around after returning. The reference | |
889 | * will be dangling until the stream is disconnected, and the default completion handler of the stream | |
890 | * will then unref the stream and destroy it */ | |
891 | if (DNS_STREAM_QUEUED(stream)) | |
892 | dns_stream_ref(stream); | |
893 | } else { | |
894 | int fd; | |
895 | ||
7994ac1d | 896 | if (!ratelimit_below(&s->ratelimit)) |
aea2429d LP |
897 | return; |
898 | ||
623a4c97 LP |
899 | if (p->family == AF_INET) |
900 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
901 | else if (p->family == AF_INET6) | |
902 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
903 | else { | |
904 | log_debug("Unknown protocol"); | |
905 | return; | |
906 | } | |
907 | if (fd < 0) { | |
da927ba9 | 908 | log_debug_errno(fd, "Failed to get reply socket: %m"); |
623a4c97 LP |
909 | return; |
910 | } | |
911 | ||
6e068472 LP |
912 | /* Note that we always immediately reply to all LLMNR |
913 | * requests, and do not wait any time, since we | |
914 | * verified uniqueness for all records. Also see RFC | |
915 | * 4795, Section 2.7 */ | |
916 | ||
b30bf55d LP |
917 | r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, NULL, reply); |
918 | if (r < 0) { | |
919 | log_debug_errno(r, "Failed to send reply packet: %m"); | |
920 | return; | |
921 | } | |
623a4c97 LP |
922 | } |
923 | } | |
ec2c5e43 | 924 | |
f52e61da | 925 | DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok) { |
ec2c5e43 LP |
926 | DnsTransaction *t; |
927 | ||
928 | assert(scope); | |
f52e61da | 929 | assert(key); |
ec2c5e43 | 930 | |
da0c630e LP |
931 | /* Try to find an ongoing transaction that is a equal to the |
932 | * specified question */ | |
f9ebb22a | 933 | t = hashmap_get(scope->transactions_by_key, key); |
4a46ed1b LP |
934 | if (!t) |
935 | return NULL; | |
dc4d47e2 | 936 | |
da0c630e LP |
937 | /* Refuse reusing transactions that completed based on cached |
938 | * data instead of a real packet, if that's requested. */ | |
939 | if (!cache_ok && | |
3bbdc31d | 940 | IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) && |
c3bc53e6 | 941 | t->answer_source != DNS_TRANSACTION_NETWORK) |
da0c630e | 942 | return NULL; |
ec2c5e43 | 943 | |
da0c630e | 944 | return t; |
ec2c5e43 | 945 | } |
a4076574 LP |
946 | |
947 | static int dns_scope_make_conflict_packet( | |
948 | DnsScope *s, | |
949 | DnsResourceRecord *rr, | |
950 | DnsPacket **ret) { | |
951 | ||
952 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
953 | int r; | |
954 | ||
955 | assert(s); | |
956 | assert(rr); | |
957 | assert(ret); | |
958 | ||
51027656 | 959 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
a4076574 LP |
960 | if (r < 0) |
961 | return r; | |
962 | ||
963 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( | |
964 | 0 /* qr */, | |
965 | 0 /* opcode */, | |
966 | 1 /* conflict */, | |
967 | 0 /* tc */, | |
968 | 0 /* t */, | |
969 | 0 /* (ra) */, | |
970 | 0 /* (ad) */, | |
971 | 0 /* (cd) */, | |
972 | 0)); | |
fe2dfc8b DM |
973 | |
974 | /* For mDNS, the transaction ID should always be 0 */ | |
975 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
976 | random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t)); | |
977 | ||
a4076574 LP |
978 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); |
979 | DNS_PACKET_HEADER(p)->arcount = htobe16(1); | |
980 | ||
58ab31d5 | 981 | r = dns_packet_append_key(p, rr->key, 0, NULL); |
a4076574 LP |
982 | if (r < 0) |
983 | return r; | |
984 | ||
58ab31d5 | 985 | r = dns_packet_append_rr(p, rr, 0, NULL, NULL); |
a4076574 LP |
986 | if (r < 0) |
987 | return r; | |
988 | ||
1cc6c93a | 989 | *ret = TAKE_PTR(p); |
a4076574 LP |
990 | |
991 | return 0; | |
992 | } | |
993 | ||
994 | static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata) { | |
995 | DnsScope *scope = userdata; | |
996 | int r; | |
997 | ||
998 | assert(es); | |
999 | assert(scope); | |
1000 | ||
1001 | scope->conflict_event_source = sd_event_source_unref(scope->conflict_event_source); | |
1002 | ||
1003 | for (;;) { | |
432d108c | 1004 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
a4076574 LP |
1005 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; |
1006 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
1007 | ||
432d108c DR |
1008 | key = ordered_hashmap_first_key(scope->conflict_queue); |
1009 | if (!key) | |
a4076574 LP |
1010 | break; |
1011 | ||
432d108c DR |
1012 | rr = ordered_hashmap_remove(scope->conflict_queue, key); |
1013 | assert(rr); | |
1014 | ||
a4076574 LP |
1015 | r = dns_scope_make_conflict_packet(scope, rr, &p); |
1016 | if (r < 0) { | |
da927ba9 | 1017 | log_error_errno(r, "Failed to make conflict packet: %m"); |
a4076574 LP |
1018 | return 0; |
1019 | } | |
1020 | ||
519ef046 | 1021 | r = dns_scope_emit_udp(scope, -1, p); |
a4076574 | 1022 | if (r < 0) |
da927ba9 | 1023 | log_debug_errno(r, "Failed to send conflict packet: %m"); |
a4076574 LP |
1024 | } |
1025 | ||
1026 | return 0; | |
1027 | } | |
1028 | ||
1029 | int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) { | |
1030 | usec_t jitter; | |
1031 | int r; | |
1032 | ||
1033 | assert(scope); | |
1034 | assert(rr); | |
1035 | ||
1036 | /* We don't send these queries immediately. Instead, we queue | |
1037 | * them, and send them after some jitter delay. */ | |
1e43061b | 1038 | r = ordered_hashmap_ensure_allocated(&scope->conflict_queue, &dns_resource_key_hash_ops); |
a4076574 LP |
1039 | if (r < 0) { |
1040 | log_oom(); | |
1041 | return r; | |
1042 | } | |
1043 | ||
1044 | /* We only place one RR per key in the conflict | |
1045 | * messages, not all of them. That should be enough to | |
1046 | * indicate where there might be a conflict */ | |
1e43061b | 1047 | r = ordered_hashmap_put(scope->conflict_queue, rr->key, rr); |
4c701096 | 1048 | if (IN_SET(r, 0, -EEXIST)) |
a4076574 | 1049 | return 0; |
f647962d MS |
1050 | if (r < 0) |
1051 | return log_debug_errno(r, "Failed to queue conflicting RR: %m"); | |
a4076574 | 1052 | |
432d108c | 1053 | dns_resource_key_ref(rr->key); |
a4076574 LP |
1054 | dns_resource_record_ref(rr); |
1055 | ||
1056 | if (scope->conflict_event_source) | |
1057 | return 0; | |
1058 | ||
1059 | random_bytes(&jitter, sizeof(jitter)); | |
1060 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
1061 | ||
39cf0351 LP |
1062 | r = sd_event_add_time_relative( |
1063 | scope->manager->event, | |
1064 | &scope->conflict_event_source, | |
1065 | clock_boottime_or_monotonic(), | |
1066 | jitter, | |
1067 | LLMNR_JITTER_INTERVAL_USEC, | |
1068 | on_conflict_dispatch, scope); | |
f647962d MS |
1069 | if (r < 0) |
1070 | return log_debug_errno(r, "Failed to add conflict dispatch event: %m"); | |
a4076574 | 1071 | |
aa4a9deb LP |
1072 | (void) sd_event_source_set_description(scope->conflict_event_source, "scope-conflict"); |
1073 | ||
a4076574 LP |
1074 | return 0; |
1075 | } | |
1076 | ||
1077 | void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) { | |
c1227a18 | 1078 | DnsResourceRecord *rr; |
a4076574 LP |
1079 | int r; |
1080 | ||
1081 | assert(scope); | |
1082 | assert(p); | |
1083 | ||
53fda2bb | 1084 | if (!IN_SET(p->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) |
a4076574 LP |
1085 | return; |
1086 | ||
1087 | if (DNS_PACKET_RRCOUNT(p) <= 0) | |
1088 | return; | |
1089 | ||
53fda2bb DR |
1090 | if (p->protocol == DNS_PROTOCOL_LLMNR) { |
1091 | if (DNS_PACKET_LLMNR_C(p) != 0) | |
1092 | return; | |
a4076574 | 1093 | |
53fda2bb DR |
1094 | if (DNS_PACKET_LLMNR_T(p) != 0) |
1095 | return; | |
1096 | } | |
a4076574 LP |
1097 | |
1098 | if (manager_our_packet(scope->manager, p)) | |
1099 | return; | |
1100 | ||
1101 | r = dns_packet_extract(p); | |
1102 | if (r < 0) { | |
da927ba9 | 1103 | log_debug_errno(r, "Failed to extract packet: %m"); |
a4076574 LP |
1104 | return; |
1105 | } | |
1106 | ||
1107 | log_debug("Checking for conflicts..."); | |
1108 | ||
c1227a18 | 1109 | DNS_ANSWER_FOREACH(rr, p->answer) { |
cfcc8dcc | 1110 | /* No conflict if it is DNS-SD RR used for service enumeration. */ |
c1227a18 | 1111 | if (dns_resource_key_is_dnssd_ptr(rr->key)) |
cfcc8dcc DR |
1112 | continue; |
1113 | ||
a4076574 LP |
1114 | /* Check for conflicts against the local zone. If we |
1115 | * found one, we won't check any further */ | |
c1227a18 | 1116 | r = dns_zone_check_conflicts(&scope->zone, rr); |
a4076574 LP |
1117 | if (r != 0) |
1118 | continue; | |
1119 | ||
1120 | /* Check for conflicts against the local cache. If so, | |
1121 | * send out an advisory query, to inform everybody */ | |
c1227a18 | 1122 | r = dns_cache_check_conflicts(&scope->cache, rr, p->family, &p->sender); |
a4076574 LP |
1123 | if (r <= 0) |
1124 | continue; | |
1125 | ||
c1227a18 | 1126 | dns_scope_notify_conflict(scope, rr); |
a4076574 LP |
1127 | } |
1128 | } | |
4d506d6b LP |
1129 | |
1130 | void dns_scope_dump(DnsScope *s, FILE *f) { | |
1131 | assert(s); | |
1132 | ||
1133 | if (!f) | |
1134 | f = stdout; | |
1135 | ||
1136 | fputs("[Scope protocol=", f); | |
1137 | fputs(dns_protocol_to_string(s->protocol), f); | |
1138 | ||
1139 | if (s->link) { | |
1140 | fputs(" interface=", f); | |
6ff79f76 | 1141 | fputs(s->link->ifname, f); |
4d506d6b LP |
1142 | } |
1143 | ||
1144 | if (s->family != AF_UNSPEC) { | |
1145 | fputs(" family=", f); | |
1146 | fputs(af_to_name(s->family), f); | |
1147 | } | |
1148 | ||
1149 | fputs("]\n", f); | |
1150 | ||
1151 | if (!dns_zone_is_empty(&s->zone)) { | |
1152 | fputs("ZONE:\n", f); | |
1153 | dns_zone_dump(&s->zone, f); | |
1154 | } | |
1155 | ||
1156 | if (!dns_cache_is_empty(&s->cache)) { | |
1157 | fputs("CACHE:\n", f); | |
1158 | dns_cache_dump(&s->cache, f); | |
1159 | } | |
1160 | } | |
a51c1048 LP |
1161 | |
1162 | DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s) { | |
801ad6a6 LP |
1163 | assert(s); |
1164 | ||
a51c1048 LP |
1165 | if (s->protocol != DNS_PROTOCOL_DNS) |
1166 | return NULL; | |
1167 | ||
1168 | if (s->link) | |
1169 | return s->link->search_domains; | |
1170 | ||
28b9b764 | 1171 | return s->manager->search_domains; |
801ad6a6 LP |
1172 | } |
1173 | ||
3b5bd7d6 | 1174 | bool dns_scope_name_wants_search_domain(DnsScope *s, const char *name) { |
801ad6a6 LP |
1175 | assert(s); |
1176 | ||
1177 | if (s->protocol != DNS_PROTOCOL_DNS) | |
dc477e73 | 1178 | return false; |
801ad6a6 | 1179 | |
dc477e73 | 1180 | return dns_name_is_single_label(name); |
801ad6a6 | 1181 | } |
edbcc1fd LP |
1182 | |
1183 | bool dns_scope_network_good(DnsScope *s) { | |
edbcc1fd LP |
1184 | /* Checks whether the network is in good state for lookups on this scope. For mDNS/LLMNR/Classic DNS scopes |
1185 | * bound to links this is easy, as they don't even exist if the link isn't in a suitable state. For the global | |
1186 | * DNS scope we check whether there are any links that are up and have an address. */ | |
1187 | ||
1188 | if (s->link) | |
1189 | return true; | |
1190 | ||
011696f7 | 1191 | return manager_routable(s->manager, AF_UNSPEC); |
edbcc1fd | 1192 | } |
97ebebbc LP |
1193 | |
1194 | int dns_scope_ifindex(DnsScope *s) { | |
1195 | assert(s); | |
1196 | ||
1197 | if (s->link) | |
1198 | return s->link->ifindex; | |
1199 | ||
1200 | return 0; | |
1201 | } | |
53fda2bb DR |
1202 | |
1203 | static int on_announcement_timeout(sd_event_source *s, usec_t usec, void *userdata) { | |
1204 | DnsScope *scope = userdata; | |
1205 | ||
1206 | assert(s); | |
1207 | ||
1208 | scope->announce_event_source = sd_event_source_unref(scope->announce_event_source); | |
1209 | ||
1a63fc54 | 1210 | (void) dns_scope_announce(scope, false); |
53fda2bb DR |
1211 | return 0; |
1212 | } | |
1213 | ||
1a63fc54 | 1214 | int dns_scope_announce(DnsScope *scope, bool goodbye) { |
53fda2bb DR |
1215 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
1216 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
a2bf8a19 DR |
1217 | _cleanup_set_free_ Set *types = NULL; |
1218 | DnsTransaction *t; | |
400f54fb | 1219 | DnsZoneItem *z, *i; |
a2bf8a19 | 1220 | unsigned size = 0; |
a2bf8a19 | 1221 | char *service_type; |
53fda2bb DR |
1222 | int r; |
1223 | ||
1224 | if (!scope) | |
1a63fc54 | 1225 | return 0; |
53fda2bb DR |
1226 | |
1227 | if (scope->protocol != DNS_PROTOCOL_MDNS) | |
1a63fc54 | 1228 | return 0; |
53fda2bb | 1229 | |
a2bf8a19 DR |
1230 | /* Check if we're done with probing. */ |
1231 | LIST_FOREACH(transactions_by_scope, t, scope->transactions) | |
1232 | if (DNS_TRANSACTION_IS_LIVE(t->state)) | |
1233 | return 0; | |
1234 | ||
e7c1b0e4 DR |
1235 | /* Check if there're services pending conflict resolution. */ |
1236 | if (manager_next_dnssd_names(scope->manager)) | |
1237 | return 0; /* we reach this point only if changing hostname didn't help */ | |
1238 | ||
a2bf8a19 | 1239 | /* Calculate answer's size. */ |
90e74a66 | 1240 | HASHMAP_FOREACH(z, scope->zone.by_key) { |
a2bf8a19 DR |
1241 | if (z->state != DNS_ZONE_ITEM_ESTABLISHED) |
1242 | continue; | |
1243 | ||
1244 | if (z->rr->key->type == DNS_TYPE_PTR && | |
1245 | !dns_zone_contains_name(&scope->zone, z->rr->ptr.name)) { | |
1246 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; | |
1247 | ||
1248 | 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)); | |
1249 | z->state = DNS_ZONE_ITEM_WITHDRAWN; | |
1250 | continue; | |
1251 | } | |
1252 | ||
1253 | /* Collect service types for _services._dns-sd._udp.local RRs in a set */ | |
1254 | if (!scope->announced && | |
1255 | dns_resource_key_is_dnssd_ptr(z->rr->key)) { | |
1256 | if (!set_contains(types, dns_resource_key_name(z->rr->key))) { | |
de7fef4b | 1257 | r = set_ensure_put(&types, &dns_name_hash_ops, dns_resource_key_name(z->rr->key)); |
a2bf8a19 DR |
1258 | if (r < 0) |
1259 | return log_debug_errno(r, "Failed to add item to set: %m"); | |
1260 | } | |
1261 | } | |
1262 | ||
400f54fb DR |
1263 | LIST_FOREACH(by_key, i, z) |
1264 | size++; | |
a2bf8a19 DR |
1265 | } |
1266 | ||
1267 | answer = dns_answer_new(size + set_size(types)); | |
1a63fc54 LP |
1268 | if (!answer) |
1269 | return log_oom(); | |
1270 | ||
a2bf8a19 | 1271 | /* Second iteration, actually add RRs to the answer. */ |
90e74a66 | 1272 | HASHMAP_FOREACH(z, scope->zone.by_key) |
400f54fb DR |
1273 | LIST_FOREACH (by_key, i, z) { |
1274 | DnsAnswerFlags flags; | |
a2bf8a19 | 1275 | |
400f54fb DR |
1276 | if (i->state != DNS_ZONE_ITEM_ESTABLISHED) |
1277 | continue; | |
a2bf8a19 | 1278 | |
400f54fb DR |
1279 | if (dns_resource_key_is_dnssd_ptr(i->rr->key)) |
1280 | flags = goodbye ? DNS_ANSWER_GOODBYE : 0; | |
1281 | else | |
1282 | flags = goodbye ? (DNS_ANSWER_GOODBYE|DNS_ANSWER_CACHE_FLUSH) : DNS_ANSWER_CACHE_FLUSH; | |
a2bf8a19 | 1283 | |
400f54fb DR |
1284 | r = dns_answer_add(answer, i->rr, 0 , flags); |
1285 | if (r < 0) | |
1286 | return log_debug_errno(r, "Failed to add RR to announce: %m"); | |
1287 | } | |
a2bf8a19 DR |
1288 | |
1289 | /* Since all the active services are in the zone make them discoverable now. */ | |
90e74a66 | 1290 | SET_FOREACH(service_type, types) { |
a2bf8a19 DR |
1291 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr; |
1292 | ||
1293 | rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, | |
1294 | "_services._dns-sd._udp.local"); | |
1295 | rr->ptr.name = strdup(service_type); | |
1296 | rr->ttl = MDNS_DEFAULT_TTL; | |
1297 | ||
1298 | r = dns_zone_put(&scope->zone, scope, rr, false); | |
1a63fc54 | 1299 | if (r < 0) |
a2bf8a19 | 1300 | log_warning_errno(r, "Failed to add DNS-SD PTR record to MDNS zone: %m"); |
1a63fc54 | 1301 | |
a2bf8a19 | 1302 | r = dns_answer_add(answer, rr, 0 , 0); |
1a63fc54 | 1303 | if (r < 0) |
a2bf8a19 | 1304 | return log_debug_errno(r, "Failed to add RR to announce: %m"); |
53fda2bb DR |
1305 | } |
1306 | ||
1307 | if (dns_answer_isempty(answer)) | |
1a63fc54 | 1308 | return 0; |
53fda2bb DR |
1309 | |
1310 | r = dns_scope_make_reply_packet(scope, 0, DNS_RCODE_SUCCESS, NULL, answer, NULL, false, &p); | |
1a63fc54 LP |
1311 | if (r < 0) |
1312 | return log_debug_errno(r, "Failed to build reply packet: %m"); | |
1313 | ||
53fda2bb | 1314 | r = dns_scope_emit_udp(scope, -1, p); |
1a63fc54 LP |
1315 | if (r < 0) |
1316 | return log_debug_errno(r, "Failed to send reply packet: %m"); | |
53fda2bb DR |
1317 | |
1318 | /* In section 8.3 of RFC6762: "The Multicast DNS responder MUST send at least two unsolicited | |
1319 | * responses, one second apart." */ | |
1320 | if (!scope->announced) { | |
53fda2bb DR |
1321 | scope->announced = true; |
1322 | ||
39cf0351 | 1323 | r = sd_event_add_time_relative( |
53fda2bb DR |
1324 | scope->manager->event, |
1325 | &scope->announce_event_source, | |
1326 | clock_boottime_or_monotonic(), | |
39cf0351 | 1327 | MDNS_ANNOUNCE_DELAY, |
53fda2bb DR |
1328 | MDNS_JITTER_RANGE_USEC, |
1329 | on_announcement_timeout, scope); | |
1330 | if (r < 0) | |
1a63fc54 | 1331 | return log_debug_errno(r, "Failed to schedule second announcement: %m"); |
19fee3ef LP |
1332 | |
1333 | (void) sd_event_source_set_description(scope->announce_event_source, "mdns-announce"); | |
53fda2bb | 1334 | } |
1a63fc54 LP |
1335 | |
1336 | return 0; | |
53fda2bb | 1337 | } |
6db6a464 DR |
1338 | |
1339 | int dns_scope_add_dnssd_services(DnsScope *scope) { | |
6db6a464 | 1340 | DnssdService *service; |
400f54fb | 1341 | DnssdTxtData *txt_data; |
6db6a464 DR |
1342 | int r; |
1343 | ||
1344 | assert(scope); | |
1345 | ||
1346 | if (hashmap_size(scope->manager->dnssd_services) == 0) | |
1347 | return 0; | |
1348 | ||
1349 | scope->announced = false; | |
1350 | ||
90e74a66 | 1351 | HASHMAP_FOREACH(service, scope->manager->dnssd_services) { |
c3036641 DR |
1352 | service->withdrawn = false; |
1353 | ||
6db6a464 DR |
1354 | r = dns_zone_put(&scope->zone, scope, service->ptr_rr, false); |
1355 | if (r < 0) | |
1356 | log_warning_errno(r, "Failed to add PTR record to MDNS zone: %m"); | |
1357 | ||
1358 | r = dns_zone_put(&scope->zone, scope, service->srv_rr, true); | |
1359 | if (r < 0) | |
1360 | log_warning_errno(r, "Failed to add SRV record to MDNS zone: %m"); | |
1361 | ||
400f54fb DR |
1362 | LIST_FOREACH(items, txt_data, service->txt_data_items) { |
1363 | r = dns_zone_put(&scope->zone, scope, txt_data->rr, true); | |
1364 | if (r < 0) | |
1365 | log_warning_errno(r, "Failed to add TXT record to MDNS zone: %m"); | |
1366 | } | |
6db6a464 DR |
1367 | } |
1368 | ||
1369 | return 0; | |
1370 | } | |
1371 | ||
1372 | int dns_scope_remove_dnssd_services(DnsScope *scope) { | |
1373 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
6db6a464 | 1374 | DnssdService *service; |
400f54fb | 1375 | DnssdTxtData *txt_data; |
6db6a464 DR |
1376 | int r; |
1377 | ||
1378 | assert(scope); | |
1379 | ||
1380 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_PTR, | |
1381 | "_services._dns-sd._udp.local"); | |
1382 | if (!key) | |
1383 | return log_oom(); | |
1384 | ||
1385 | r = dns_zone_remove_rrs_by_key(&scope->zone, key); | |
1386 | if (r < 0) | |
1387 | return r; | |
1388 | ||
90e74a66 | 1389 | HASHMAP_FOREACH(service, scope->manager->dnssd_services) { |
6db6a464 DR |
1390 | dns_zone_remove_rr(&scope->zone, service->ptr_rr); |
1391 | dns_zone_remove_rr(&scope->zone, service->srv_rr); | |
400f54fb DR |
1392 | LIST_FOREACH(items, txt_data, service->txt_data_items) |
1393 | dns_zone_remove_rr(&scope->zone, txt_data->rr); | |
6db6a464 DR |
1394 | } |
1395 | ||
1396 | return 0; | |
1397 | } | |
f76fa088 | 1398 | |
ca5394d2 | 1399 | static bool dns_scope_has_route_only_domains(DnsScope *scope) { |
f76fa088 LP |
1400 | DnsSearchDomain *domain, *first; |
1401 | bool route_only = false; | |
1402 | ||
ca5394d2 LP |
1403 | assert(scope); |
1404 | assert(scope->protocol == DNS_PROTOCOL_DNS); | |
f76fa088 | 1405 | |
ca5394d2 LP |
1406 | /* Returns 'true' if this scope is suitable for queries to specific domains only. For that we check |
1407 | * if there are any route-only domains on this interface, as a heuristic to discern VPN-style links | |
1408 | * from non-VPN-style links. Returns 'false' for all other cases, i.e. if the scope is intended to | |
1409 | * take queries to arbitrary domains, i.e. has no routing domains set. */ | |
f76fa088 LP |
1410 | |
1411 | if (scope->link) | |
1412 | first = scope->link->search_domains; | |
1413 | else | |
1414 | first = scope->manager->search_domains; | |
1415 | ||
1416 | LIST_FOREACH(domains, domain, first) { | |
ca5394d2 LP |
1417 | /* "." means "any domain", thus the interface takes any kind of traffic. Thus, we exit early |
1418 | * here, as it doesn't really matter whether this link has any route-only domains or not, | |
1419 | * "~." really trumps everything and clearly indicates that this interface shall receive all | |
1420 | * traffic it can get. */ | |
f76fa088 LP |
1421 | if (dns_name_is_root(DNS_SEARCH_DOMAIN_NAME(domain))) |
1422 | return false; | |
1423 | ||
1424 | if (domain->route_only) | |
1425 | route_only = true; | |
1426 | } | |
1427 | ||
1428 | return route_only; | |
1429 | } | |
ca5394d2 LP |
1430 | |
1431 | bool dns_scope_is_default_route(DnsScope *scope) { | |
1432 | assert(scope); | |
1433 | ||
1434 | /* Only use DNS scopes as default routes */ | |
1435 | if (scope->protocol != DNS_PROTOCOL_DNS) | |
1436 | return false; | |
1437 | ||
1438 | /* The global DNS scope is always suitable as default route */ | |
1439 | if (!scope->link) | |
1440 | return true; | |
1441 | ||
1442 | /* Honour whatever is explicitly configured. This is really the best approach, and trumps any | |
1443 | * automatic logic. */ | |
1444 | if (scope->link->default_route >= 0) | |
1445 | return scope->link->default_route; | |
1446 | ||
1447 | /* Otherwise check if we have any route-only domains, as a sensible heuristic: if so, let's not | |
1448 | * volunteer as default route. */ | |
1449 | return !dns_scope_has_route_only_domains(scope); | |
1450 | } |