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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" | |
10 | #include "missing.h" | |
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 | ||
33 | s = new0(DnsScope, 1); | |
34 | if (!s) | |
35 | return -ENOMEM; | |
36 | ||
37 | s->manager = m; | |
1716f6dc LP |
38 | s->link = l; |
39 | s->protocol = protocol; | |
40 | s->family = family; | |
9df3ba6c | 41 | s->resend_timeout = MULTICAST_RESEND_TIMEOUT_MIN_USEC; |
74b2466e | 42 | |
ad6c0475 LP |
43 | if (protocol == DNS_PROTOCOL_DNS) { |
44 | /* Copy DNSSEC mode from the link if it is set there, | |
45 | * otherwise take the manager's DNSSEC mode. Note that | |
46 | * we copy this only at scope creation time, and do | |
47 | * not update it from the on, even if the setting | |
48 | * changes. */ | |
49 | ||
d050561a | 50 | if (l) { |
c69fa7e3 | 51 | s->dnssec_mode = link_get_dnssec_mode(l); |
c9299be2 | 52 | s->dns_over_tls_mode = link_get_dns_over_tls_mode(l); |
d050561a | 53 | } else { |
c69fa7e3 | 54 | s->dnssec_mode = manager_get_dnssec_mode(m); |
c9299be2 | 55 | s->dns_over_tls_mode = manager_get_dns_over_tls_mode(m); |
d050561a | 56 | } |
5d67a7ae | 57 | |
5d67a7ae | 58 | } else { |
658f7f02 | 59 | s->dnssec_mode = DNSSEC_NO; |
c9299be2 | 60 | s->dns_over_tls_mode = DNS_OVER_TLS_NO; |
5d67a7ae | 61 | } |
ad6c0475 | 62 | |
74b2466e LP |
63 | LIST_PREPEND(scopes, m->dns_scopes, s); |
64 | ||
1716f6dc | 65 | dns_scope_llmnr_membership(s, true); |
0db4c90a | 66 | dns_scope_mdns_membership(s, true); |
1716f6dc | 67 | |
46f08bea | 68 | 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 | 69 | |
aea2429d LP |
70 | /* Enforce ratelimiting for the multicast protocols */ |
71 | RATELIMIT_INIT(s->ratelimit, MULTICAST_RATELIMIT_INTERVAL_USEC, MULTICAST_RATELIMIT_BURST); | |
72 | ||
74b2466e LP |
73 | *ret = s; |
74 | return 0; | |
75 | } | |
76 | ||
801ad6a6 | 77 | static void dns_scope_abort_transactions(DnsScope *s) { |
801ad6a6 | 78 | assert(s); |
1716f6dc | 79 | |
f9ebb22a LP |
80 | while (s->transactions) { |
81 | DnsTransaction *t = s->transactions; | |
82 | ||
faa133f3 LP |
83 | /* Abort the transaction, but make sure it is not |
84 | * freed while we still look at it */ | |
74b2466e | 85 | |
faa133f3 | 86 | t->block_gc++; |
f4e38037 LP |
87 | if (DNS_TRANSACTION_IS_LIVE(t->state)) |
88 | dns_transaction_complete(t, DNS_TRANSACTION_ABORTED); | |
faa133f3 | 89 | t->block_gc--; |
74b2466e | 90 | |
ec2c5e43 | 91 | dns_transaction_free(t); |
74b2466e | 92 | } |
801ad6a6 LP |
93 | } |
94 | ||
95 | DnsScope* dns_scope_free(DnsScope *s) { | |
801ad6a6 LP |
96 | if (!s) |
97 | return NULL; | |
98 | ||
99 | 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)); | |
100 | ||
101 | dns_scope_llmnr_membership(s, false); | |
0db4c90a | 102 | dns_scope_mdns_membership(s, false); |
801ad6a6 LP |
103 | dns_scope_abort_transactions(s); |
104 | ||
105 | while (s->query_candidates) | |
106 | dns_query_candidate_free(s->query_candidates); | |
74b2466e | 107 | |
f9ebb22a | 108 | hashmap_free(s->transactions_by_key); |
da0c630e | 109 | |
224b0e7a | 110 | ordered_hashmap_free_with_destructor(s->conflict_queue, dns_resource_record_unref); |
a4076574 LP |
111 | sd_event_source_unref(s->conflict_event_source); |
112 | ||
53fda2bb DR |
113 | sd_event_source_unref(s->announce_event_source); |
114 | ||
322345fd | 115 | dns_cache_flush(&s->cache); |
623a4c97 | 116 | dns_zone_flush(&s->zone); |
322345fd | 117 | |
74b2466e | 118 | LIST_REMOVE(scopes, s->manager->dns_scopes, s); |
6b430fdb | 119 | return mfree(s); |
74b2466e LP |
120 | } |
121 | ||
2c27fbca | 122 | DnsServer *dns_scope_get_dns_server(DnsScope *s) { |
74b2466e LP |
123 | assert(s); |
124 | ||
1716f6dc LP |
125 | if (s->protocol != DNS_PROTOCOL_DNS) |
126 | return NULL; | |
127 | ||
74b2466e LP |
128 | if (s->link) |
129 | return link_get_dns_server(s->link); | |
130 | else | |
131 | return manager_get_dns_server(s->manager); | |
132 | } | |
133 | ||
44db02d0 LP |
134 | unsigned dns_scope_get_n_dns_servers(DnsScope *s) { |
135 | unsigned n = 0; | |
136 | DnsServer *i; | |
137 | ||
138 | assert(s); | |
139 | ||
140 | if (s->protocol != DNS_PROTOCOL_DNS) | |
141 | return 0; | |
142 | ||
143 | if (s->link) | |
144 | i = s->link->dns_servers; | |
145 | else | |
146 | i = s->manager->dns_servers; | |
147 | ||
148 | for (; i; i = i->servers_next) | |
149 | n++; | |
150 | ||
151 | return n; | |
152 | } | |
153 | ||
74b2466e LP |
154 | void dns_scope_next_dns_server(DnsScope *s) { |
155 | assert(s); | |
156 | ||
1716f6dc LP |
157 | if (s->protocol != DNS_PROTOCOL_DNS) |
158 | return; | |
159 | ||
74b2466e LP |
160 | if (s->link) |
161 | link_next_dns_server(s->link); | |
162 | else | |
163 | manager_next_dns_server(s->manager); | |
164 | } | |
165 | ||
9df3ba6c TG |
166 | void dns_scope_packet_received(DnsScope *s, usec_t rtt) { |
167 | assert(s); | |
168 | ||
84129d46 LP |
169 | if (rtt <= s->max_rtt) |
170 | return; | |
171 | ||
172 | s->max_rtt = rtt; | |
173 | s->resend_timeout = MIN(MAX(MULTICAST_RESEND_TIMEOUT_MIN_USEC, s->max_rtt * 2), MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
9df3ba6c TG |
174 | } |
175 | ||
176 | void dns_scope_packet_lost(DnsScope *s, usec_t usec) { | |
177 | assert(s); | |
178 | ||
179 | if (s->resend_timeout <= usec) | |
180 | s->resend_timeout = MIN(s->resend_timeout * 2, MULTICAST_RESEND_TIMEOUT_MAX_USEC); | |
181 | } | |
182 | ||
519ef046 | 183 | static int dns_scope_emit_one(DnsScope *s, int fd, DnsPacket *p) { |
1716f6dc LP |
184 | union in_addr_union addr; |
185 | int ifindex = 0, r; | |
0dd25fb9 | 186 | int family; |
1716f6dc | 187 | uint32_t mtu; |
74b2466e LP |
188 | |
189 | assert(s); | |
190 | assert(p); | |
1716f6dc | 191 | assert(p->protocol == s->protocol); |
ad867662 LP |
192 | |
193 | if (s->link) { | |
1716f6dc | 194 | mtu = s->link->mtu; |
74b2466e | 195 | ifindex = s->link->ifindex; |
1716f6dc | 196 | } else |
e1c95994 | 197 | mtu = manager_find_mtu(s->manager); |
74b2466e | 198 | |
106784eb | 199 | switch (s->protocol) { |
519ef046 | 200 | |
106784eb | 201 | case DNS_PROTOCOL_DNS: |
519ef046 | 202 | assert(fd >= 0); |
9c5e12a4 | 203 | |
623a4c97 | 204 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 205 | return -EOPNOTSUPP; |
623a4c97 | 206 | |
1716f6dc LP |
207 | if (p->size > DNS_PACKET_UNICAST_SIZE_MAX) |
208 | return -EMSGSIZE; | |
209 | ||
a0166609 | 210 | if (p->size + UDP_PACKET_HEADER_SIZE > mtu) |
1716f6dc LP |
211 | return -EMSGSIZE; |
212 | ||
72290734 TG |
213 | r = manager_write(s->manager, fd, p); |
214 | if (r < 0) | |
215 | return r; | |
216 | ||
106784eb | 217 | break; |
1716f6dc | 218 | |
106784eb | 219 | case DNS_PROTOCOL_LLMNR: |
519ef046 LP |
220 | assert(fd < 0); |
221 | ||
1716f6dc | 222 | if (DNS_PACKET_QDCOUNT(p) > 1) |
15411c0c | 223 | return -EOPNOTSUPP; |
1716f6dc | 224 | |
7994ac1d | 225 | if (!ratelimit_below(&s->ratelimit)) |
aea2429d LP |
226 | return -EBUSY; |
227 | ||
1716f6dc | 228 | family = s->family; |
1716f6dc LP |
229 | |
230 | if (family == AF_INET) { | |
231 | addr.in = LLMNR_MULTICAST_IPV4_ADDRESS; | |
1716f6dc LP |
232 | fd = manager_llmnr_ipv4_udp_fd(s->manager); |
233 | } else if (family == AF_INET6) { | |
234 | addr.in6 = LLMNR_MULTICAST_IPV6_ADDRESS; | |
235 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
1716f6dc LP |
236 | } else |
237 | return -EAFNOSUPPORT; | |
238 | if (fd < 0) | |
239 | return fd; | |
72290734 | 240 | |
b30bf55d | 241 | r = manager_send(s->manager, fd, ifindex, family, &addr, LLMNR_PORT, NULL, p); |
b4f1862d DM |
242 | if (r < 0) |
243 | return r; | |
244 | ||
245 | break; | |
246 | ||
247 | case DNS_PROTOCOL_MDNS: | |
519ef046 LP |
248 | assert(fd < 0); |
249 | ||
7994ac1d | 250 | if (!ratelimit_below(&s->ratelimit)) |
b4f1862d DM |
251 | return -EBUSY; |
252 | ||
253 | family = s->family; | |
254 | ||
255 | if (family == AF_INET) { | |
256 | addr.in = MDNS_MULTICAST_IPV4_ADDRESS; | |
257 | fd = manager_mdns_ipv4_fd(s->manager); | |
258 | } else if (family == AF_INET6) { | |
259 | addr.in6 = MDNS_MULTICAST_IPV6_ADDRESS; | |
260 | fd = manager_mdns_ipv6_fd(s->manager); | |
261 | } else | |
262 | return -EAFNOSUPPORT; | |
263 | if (fd < 0) | |
264 | return fd; | |
265 | ||
b30bf55d | 266 | r = manager_send(s->manager, fd, ifindex, family, &addr, MDNS_PORT, NULL, p); |
72290734 TG |
267 | if (r < 0) |
268 | return r; | |
106784eb DM |
269 | |
270 | break; | |
271 | ||
272 | default: | |
74b2466e | 273 | return -EAFNOSUPPORT; |
106784eb | 274 | } |
74b2466e | 275 | |
74b2466e LP |
276 | return 1; |
277 | } | |
278 | ||
519ef046 | 279 | int dns_scope_emit_udp(DnsScope *s, int fd, DnsPacket *p) { |
80a62095 DM |
280 | int r; |
281 | ||
282 | assert(s); | |
283 | assert(p); | |
284 | assert(p->protocol == s->protocol); | |
519ef046 | 285 | assert((s->protocol == DNS_PROTOCOL_DNS) == (fd >= 0)); |
80a62095 DM |
286 | |
287 | do { | |
288 | /* If there are multiple linked packets, set the TC bit in all but the last of them */ | |
289 | if (p->more) { | |
290 | assert(p->protocol == DNS_PROTOCOL_MDNS); | |
261f3673 | 291 | dns_packet_set_flags(p, true, true); |
80a62095 DM |
292 | } |
293 | ||
519ef046 | 294 | r = dns_scope_emit_one(s, fd, p); |
80a62095 DM |
295 | if (r < 0) |
296 | return r; | |
297 | ||
298 | p = p->more; | |
519ef046 | 299 | } while (p); |
80a62095 DM |
300 | |
301 | return 0; | |
302 | } | |
303 | ||
519ef046 LP |
304 | static int dns_scope_socket( |
305 | DnsScope *s, | |
306 | int type, | |
307 | int family, | |
308 | const union in_addr_union *address, | |
309 | DnsServer *server, | |
91ccab1e IT |
310 | uint16_t port, |
311 | union sockaddr_union *ret_socket_address) { | |
519ef046 | 312 | |
ad867662 | 313 | _cleanup_close_ int fd = -1; |
91ccab1e | 314 | union sockaddr_union sa; |
ad867662 | 315 | socklen_t salen; |
623a4c97 | 316 | static const int one = 1; |
c10d6bdb | 317 | int r, ifindex; |
ad867662 LP |
318 | |
319 | assert(s); | |
be808ea0 | 320 | |
519ef046 LP |
321 | if (server) { |
322 | assert(family == AF_UNSPEC); | |
323 | assert(!address); | |
be808ea0 | 324 | |
2817157b LP |
325 | ifindex = dns_server_ifindex(server); |
326 | ||
519ef046 LP |
327 | sa.sa.sa_family = server->family; |
328 | if (server->family == AF_INET) { | |
623a4c97 | 329 | sa.in.sin_port = htobe16(port); |
519ef046 | 330 | sa.in.sin_addr = server->address.in; |
623a4c97 | 331 | salen = sizeof(sa.in); |
519ef046 | 332 | } else if (server->family == AF_INET6) { |
623a4c97 | 333 | sa.in6.sin6_port = htobe16(port); |
519ef046 | 334 | sa.in6.sin6_addr = server->address.in6; |
2817157b | 335 | sa.in6.sin6_scope_id = ifindex; |
623a4c97 LP |
336 | salen = sizeof(sa.in6); |
337 | } else | |
338 | return -EAFNOSUPPORT; | |
339 | } else { | |
519ef046 LP |
340 | assert(family != AF_UNSPEC); |
341 | assert(address); | |
342 | ||
623a4c97 | 343 | sa.sa.sa_family = family; |
2817157b | 344 | ifindex = s->link ? s->link->ifindex : 0; |
623a4c97 LP |
345 | |
346 | if (family == AF_INET) { | |
347 | sa.in.sin_port = htobe16(port); | |
348 | sa.in.sin_addr = address->in; | |
349 | salen = sizeof(sa.in); | |
350 | } else if (family == AF_INET6) { | |
351 | sa.in6.sin6_port = htobe16(port); | |
352 | sa.in6.sin6_addr = address->in6; | |
2817157b | 353 | sa.in6.sin6_scope_id = ifindex; |
623a4c97 LP |
354 | salen = sizeof(sa.in6); |
355 | } else | |
356 | return -EAFNOSUPPORT; | |
357 | } | |
ad867662 | 358 | |
0db64366 | 359 | fd = socket(sa.sa.sa_family, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
ad867662 LP |
360 | if (fd < 0) |
361 | return -errno; | |
362 | ||
0db64366 TG |
363 | if (type == SOCK_STREAM) { |
364 | r = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); | |
365 | if (r < 0) | |
366 | return -errno; | |
367 | } | |
623a4c97 LP |
368 | |
369 | if (s->link) { | |
2817157b | 370 | be32_t ifindex_be = htobe32(ifindex); |
623a4c97 LP |
371 | |
372 | if (sa.sa.sa_family == AF_INET) { | |
2817157b | 373 | r = setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
374 | if (r < 0) |
375 | return -errno; | |
376 | } else if (sa.sa.sa_family == AF_INET6) { | |
2817157b | 377 | r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_be, sizeof(ifindex_be)); |
623a4c97 LP |
378 | if (r < 0) |
379 | return -errno; | |
380 | } | |
381 | } | |
382 | ||
383 | if (s->protocol == DNS_PROTOCOL_LLMNR) { | |
bf3f1271 | 384 | /* RFC 4795, section 2.5 requires the TTL to be set to 1 */ |
623a4c97 LP |
385 | |
386 | if (sa.sa.sa_family == AF_INET) { | |
387 | r = setsockopt(fd, IPPROTO_IP, IP_TTL, &one, sizeof(one)); | |
388 | if (r < 0) | |
389 | return -errno; | |
390 | } else if (sa.sa.sa_family == AF_INET6) { | |
391 | r = setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one)); | |
392 | if (r < 0) | |
393 | return -errno; | |
394 | } | |
395 | } | |
ad867662 | 396 | |
91ccab1e IT |
397 | if (ret_socket_address) |
398 | *ret_socket_address = sa; | |
399 | else { | |
400 | r = connect(fd, &sa.sa, salen); | |
401 | if (r < 0 && errno != EINPROGRESS) | |
402 | return -errno; | |
403 | } | |
ad867662 | 404 | |
c10d6bdb | 405 | return TAKE_FD(fd); |
ad867662 LP |
406 | } |
407 | ||
519ef046 | 408 | int dns_scope_socket_udp(DnsScope *s, DnsServer *server, uint16_t port) { |
91ccab1e | 409 | return dns_scope_socket(s, SOCK_DGRAM, AF_UNSPEC, NULL, server, port, NULL); |
0db64366 TG |
410 | } |
411 | ||
91ccab1e IT |
412 | 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) { |
413 | /* If ret_socket_address is not NULL, the caller is responisble | |
414 | * for calling connect() or sendmsg(). This is required by TCP | |
415 | * Fast Open, to be able to send the initial SYN packet along | |
416 | * with the first data packet. */ | |
417 | return dns_scope_socket(s, SOCK_STREAM, family, address, server, port, ret_socket_address); | |
0db64366 TG |
418 | } |
419 | ||
51323288 | 420 | DnsScopeMatch dns_scope_good_domain(DnsScope *s, int ifindex, uint64_t flags, const char *domain) { |
a51c1048 | 421 | DnsSearchDomain *d; |
74b2466e LP |
422 | |
423 | assert(s); | |
424 | assert(domain); | |
425 | ||
28b9b764 LP |
426 | /* Checks if the specified domain is something to look up on |
427 | * this scope. Note that this accepts non-qualified hostnames, | |
428 | * i.e. those without any search path prefixed yet. */ | |
429 | ||
51323288 LP |
430 | if (ifindex != 0 && (!s->link || s->link->ifindex != ifindex)) |
431 | return DNS_SCOPE_NO; | |
432 | ||
931851e8 | 433 | if ((SD_RESOLVED_FLAGS_MAKE(s->protocol, s->family, 0) & flags) == 0) |
51323288 LP |
434 | return DNS_SCOPE_NO; |
435 | ||
78c6a153 LP |
436 | /* Never resolve any loopback hostname or IP address via DNS, |
437 | * LLMNR or mDNS. Instead, always rely on synthesized RRs for | |
438 | * these. */ | |
439 | if (is_localhost(domain) || | |
440 | dns_name_endswith(domain, "127.in-addr.arpa") > 0 || | |
9436e8ca LP |
441 | 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) |
442 | return DNS_SCOPE_NO; | |
443 | ||
c9ad0edb LP |
444 | /* Never respond to some of the domains listed in RFC6303 */ |
445 | if (dns_name_endswith(domain, "0.in-addr.arpa") > 0 || | |
446 | dns_name_equal(domain, "255.255.255.255.in-addr.arpa") > 0 || | |
447 | 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) | |
448 | return DNS_SCOPE_NO; | |
449 | ||
7bcffc2e LP |
450 | /* Never respond to some of the domains listed in RFC6761 */ |
451 | if (dns_name_endswith(domain, "invalid") > 0) | |
452 | return DNS_SCOPE_NO; | |
453 | ||
106784eb | 454 | switch (s->protocol) { |
801ad6a6 | 455 | |
613dca46 LP |
456 | case DNS_PROTOCOL_DNS: { |
457 | DnsServer *dns_server; | |
458 | ||
459 | /* Never route things to scopes that lack DNS servers */ | |
460 | dns_server = dns_scope_get_dns_server(s); | |
461 | if (!dns_server) | |
462 | return DNS_SCOPE_NO; | |
463 | ||
464 | /* Always honour search domains for routing queries, except if this scope lacks DNS servers. Note that | |
465 | * we return DNS_SCOPE_YES here, rather than just DNS_SCOPE_MAYBE, which means other wildcard scopes | |
466 | * won't be considered anymore. */ | |
467 | LIST_FOREACH(domains, d, dns_scope_get_search_domains(s)) | |
468 | if (dns_name_endswith(domain, d->name) > 0) | |
469 | return DNS_SCOPE_YES; | |
470 | ||
471 | /* If the DNS server has route-only domains, don't send other requests to it. This would be a privacy | |
472 | * violation, will most probably fail anyway, and adds unnecessary load. */ | |
473 | if (dns_server_limited_domains(dns_server)) | |
474 | return DNS_SCOPE_NO; | |
801ad6a6 | 475 | |
28b9b764 LP |
476 | /* Exclude link-local IP ranges */ |
477 | if (dns_name_endswith(domain, "254.169.in-addr.arpa") == 0 && | |
c9ad0edb LP |
478 | dns_name_endswith(domain, "8.e.f.ip6.arpa") == 0 && |
479 | dns_name_endswith(domain, "9.e.f.ip6.arpa") == 0 && | |
480 | dns_name_endswith(domain, "a.e.f.ip6.arpa") == 0 && | |
b43d96b0 DM |
481 | dns_name_endswith(domain, "b.e.f.ip6.arpa") == 0 && |
482 | /* If networks use .local in their private setups, they are supposed to also add .local to their search | |
483 | * domains, which we already checked above. Otherwise, we consider .local specific to mDNS and won't | |
484 | * send such queries ordinary DNS servers. */ | |
485 | dns_name_endswith(domain, "local") == 0) | |
faa133f3 | 486 | return DNS_SCOPE_MAYBE; |
1716f6dc | 487 | |
faa133f3 | 488 | return DNS_SCOPE_NO; |
613dca46 | 489 | } |
1716f6dc | 490 | |
106784eb | 491 | case DNS_PROTOCOL_MDNS: |
78c6a153 LP |
492 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
493 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || | |
494 | (dns_name_endswith(domain, "local") > 0 && /* only resolve names ending in .local via mDNS */ | |
495 | dns_name_equal(domain, "local") == 0 && /* but not the single-label "local" name itself */ | |
496 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via mDNS */ | |
d8b7e75f | 497 | return DNS_SCOPE_MAYBE; |
74b2466e LP |
498 | |
499 | return DNS_SCOPE_NO; | |
74b2466e | 500 | |
106784eb | 501 | case DNS_PROTOCOL_LLMNR: |
78c6a153 LP |
502 | if ((s->family == AF_INET && dns_name_endswith(domain, "in-addr.arpa") > 0) || |
503 | (s->family == AF_INET6 && dns_name_endswith(domain, "ip6.arpa") > 0) || | |
dc477e73 | 504 | (dns_name_is_single_label(domain) && /* only resolve single label names via LLMNR */ |
78c6a153 LP |
505 | !is_gateway_hostname(domain) && /* don't resolve "gateway" with LLMNR, let nss-myhostname handle this */ |
506 | manager_is_own_hostname(s->manager, domain) <= 0)) /* never resolve the local hostname via LLMNR */ | |
1716f6dc | 507 | return DNS_SCOPE_MAYBE; |
74b2466e | 508 | |
1716f6dc | 509 | return DNS_SCOPE_NO; |
74b2466e | 510 | |
106784eb DM |
511 | default: |
512 | assert_not_reached("Unknown scope protocol"); | |
513 | } | |
1716f6dc LP |
514 | } |
515 | ||
011696f7 LP |
516 | bool dns_scope_good_key(DnsScope *s, const DnsResourceKey *key) { |
517 | int key_family; | |
518 | ||
1716f6dc LP |
519 | assert(s); |
520 | assert(key); | |
521 | ||
28b9b764 LP |
522 | /* Check if it makes sense to resolve the specified key on |
523 | * this scope. Note that this call assumes as fully qualified | |
524 | * name, i.e. the search suffixes already appended. */ | |
525 | ||
011696f7 LP |
526 | if (key->class != DNS_CLASS_IN) |
527 | return false; | |
528 | ||
28b9b764 LP |
529 | if (s->protocol == DNS_PROTOCOL_DNS) { |
530 | ||
e5abebab | 531 | /* On classic DNS, looking up non-address RRs is always |
28b9b764 LP |
532 | * fine. (Specifically, we want to permit looking up |
533 | * DNSKEY and DS records on the root and top-level | |
534 | * domains.) */ | |
535 | if (!dns_resource_key_is_address(key)) | |
536 | return true; | |
537 | ||
538 | /* However, we refuse to look up A and AAAA RRs on the | |
539 | * root and single-label domains, under the assumption | |
540 | * that those should be resolved via LLMNR or search | |
541 | * path only, and should not be leaked onto the | |
542 | * internet. */ | |
1c02e7ba ZJS |
543 | return !(dns_name_is_single_label(dns_resource_key_name(key)) || |
544 | dns_name_is_root(dns_resource_key_name(key))); | |
28b9b764 | 545 | } |
1716f6dc LP |
546 | |
547 | /* On mDNS and LLMNR, send A and AAAA queries only on the | |
548 | * respective scopes */ | |
549 | ||
011696f7 LP |
550 | key_family = dns_type_to_af(key->type); |
551 | if (key_family < 0) | |
552 | return true; | |
1716f6dc | 553 | |
011696f7 | 554 | return key_family == s->family; |
1716f6dc LP |
555 | } |
556 | ||
0db4c90a | 557 | static int dns_scope_multicast_membership(DnsScope *s, bool b, struct in_addr in, struct in6_addr in6) { |
1716f6dc LP |
558 | int fd; |
559 | ||
5ba73e9b | 560 | assert(s); |
5ba73e9b LP |
561 | assert(s->link); |
562 | ||
1716f6dc LP |
563 | if (s->family == AF_INET) { |
564 | struct ip_mreqn mreqn = { | |
0db4c90a | 565 | .imr_multiaddr = in, |
1716f6dc LP |
566 | .imr_ifindex = s->link->ifindex, |
567 | }; | |
568 | ||
d37baf40 DR |
569 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
570 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
571 | else | |
572 | fd = manager_mdns_ipv4_fd(s->manager); | |
573 | ||
1716f6dc LP |
574 | if (fd < 0) |
575 | return fd; | |
576 | ||
7b4c2ee7 LP |
577 | /* Always first try to drop membership before we add |
578 | * one. This is necessary on some devices, such as | |
579 | * veth. */ | |
580 | if (b) | |
dc751688 | 581 | (void) setsockopt(fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)); |
7b4c2ee7 | 582 | |
1716f6dc LP |
583 | if (setsockopt(fd, IPPROTO_IP, b ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, &mreqn, sizeof(mreqn)) < 0) |
584 | return -errno; | |
585 | ||
586 | } else if (s->family == AF_INET6) { | |
587 | struct ipv6_mreq mreq = { | |
0db4c90a | 588 | .ipv6mr_multiaddr = in6, |
1716f6dc LP |
589 | .ipv6mr_interface = s->link->ifindex, |
590 | }; | |
591 | ||
d37baf40 DR |
592 | if (s->protocol == DNS_PROTOCOL_LLMNR) |
593 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
594 | else | |
595 | fd = manager_mdns_ipv6_fd(s->manager); | |
596 | ||
1716f6dc LP |
597 | if (fd < 0) |
598 | return fd; | |
599 | ||
7b4c2ee7 | 600 | if (b) |
dc751688 | 601 | (void) setsockopt(fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)); |
7b4c2ee7 | 602 | |
1716f6dc LP |
603 | if (setsockopt(fd, IPPROTO_IPV6, b ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) |
604 | return -errno; | |
605 | } else | |
606 | return -EAFNOSUPPORT; | |
607 | ||
608 | return 0; | |
74b2466e | 609 | } |
623a4c97 | 610 | |
0db4c90a | 611 | int dns_scope_llmnr_membership(DnsScope *s, bool b) { |
f471bc11 | 612 | assert(s); |
0db4c90a DM |
613 | |
614 | if (s->protocol != DNS_PROTOCOL_LLMNR) | |
615 | return 0; | |
616 | ||
617 | return dns_scope_multicast_membership(s, b, LLMNR_MULTICAST_IPV4_ADDRESS, LLMNR_MULTICAST_IPV6_ADDRESS); | |
618 | } | |
619 | ||
620 | int dns_scope_mdns_membership(DnsScope *s, bool b) { | |
f471bc11 | 621 | assert(s); |
0db4c90a DM |
622 | |
623 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
624 | return 0; | |
625 | ||
626 | return dns_scope_multicast_membership(s, b, MDNS_MULTICAST_IPV4_ADDRESS, MDNS_MULTICAST_IPV6_ADDRESS); | |
627 | } | |
628 | ||
3b991089 | 629 | int dns_scope_make_reply_packet( |
ec2c5e43 LP |
630 | DnsScope *s, |
631 | uint16_t id, | |
632 | int rcode, | |
633 | DnsQuestion *q, | |
634 | DnsAnswer *answer, | |
635 | DnsAnswer *soa, | |
636 | bool tentative, | |
637 | DnsPacket **ret) { | |
638 | ||
623a4c97 | 639 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
623a4c97 LP |
640 | int r; |
641 | ||
642 | assert(s); | |
a4076574 | 643 | assert(ret); |
623a4c97 | 644 | |
501e8eb0 LP |
645 | if (dns_question_isempty(q) && |
646 | dns_answer_isempty(answer) && | |
647 | dns_answer_isempty(soa)) | |
623a4c97 LP |
648 | return -EINVAL; |
649 | ||
51027656 | 650 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
623a4c97 LP |
651 | if (r < 0) |
652 | return r; | |
653 | ||
654 | DNS_PACKET_HEADER(p)->id = id; | |
ea917db9 LP |
655 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( |
656 | 1 /* qr */, | |
657 | 0 /* opcode */, | |
658 | 0 /* c */, | |
659 | 0 /* tc */, | |
ec2c5e43 | 660 | tentative, |
ea917db9 LP |
661 | 0 /* (ra) */, |
662 | 0 /* (ad) */, | |
663 | 0 /* (cd) */, | |
664 | rcode)); | |
623a4c97 | 665 | |
f471bc11 LP |
666 | r = dns_packet_append_question(p, q); |
667 | if (r < 0) | |
668 | return r; | |
669 | DNS_PACKET_HEADER(p)->qdcount = htobe16(dns_question_size(q)); | |
8bf52d3d | 670 | |
f471bc11 LP |
671 | r = dns_packet_append_answer(p, answer); |
672 | if (r < 0) | |
673 | return r; | |
674 | DNS_PACKET_HEADER(p)->ancount = htobe16(dns_answer_size(answer)); | |
8bf52d3d | 675 | |
f471bc11 LP |
676 | r = dns_packet_append_answer(p, soa); |
677 | if (r < 0) | |
678 | return r; | |
679 | DNS_PACKET_HEADER(p)->arcount = htobe16(dns_answer_size(soa)); | |
623a4c97 | 680 | |
1cc6c93a | 681 | *ret = TAKE_PTR(p); |
623a4c97 LP |
682 | |
683 | return 0; | |
684 | } | |
685 | ||
a4076574 | 686 | static void dns_scope_verify_conflicts(DnsScope *s, DnsPacket *p) { |
2a3900d7 LP |
687 | DnsResourceRecord *rr; |
688 | DnsResourceKey *key; | |
a4076574 LP |
689 | |
690 | assert(s); | |
691 | assert(p); | |
692 | ||
2a3900d7 LP |
693 | DNS_QUESTION_FOREACH(key, p->question) |
694 | dns_zone_verify_conflicts(&s->zone, key); | |
695 | ||
696 | DNS_ANSWER_FOREACH(rr, p->answer) | |
697 | dns_zone_verify_conflicts(&s->zone, rr->key); | |
a4076574 LP |
698 | } |
699 | ||
623a4c97 | 700 | void dns_scope_process_query(DnsScope *s, DnsStream *stream, DnsPacket *p) { |
8bf52d3d | 701 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL, *soa = NULL; |
b30bf55d | 702 | _cleanup_(dns_packet_unrefp) DnsPacket *reply = NULL; |
5032b16d | 703 | DnsResourceKey *key = NULL; |
ec2c5e43 | 704 | bool tentative = false; |
b30bf55d | 705 | int r; |
623a4c97 LP |
706 | |
707 | assert(s); | |
708 | assert(p); | |
709 | ||
710 | if (p->protocol != DNS_PROTOCOL_LLMNR) | |
711 | return; | |
712 | ||
2442b93d LP |
713 | if (p->ipproto == IPPROTO_UDP) { |
714 | /* Don't accept UDP queries directed to anything but | |
715 | * the LLMNR multicast addresses. See RFC 4795, | |
d076c6f9 | 716 | * section 2.5. */ |
2442b93d LP |
717 | |
718 | if (p->family == AF_INET && !in_addr_equal(AF_INET, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV4_ADDRESS)) | |
719 | return; | |
720 | ||
721 | if (p->family == AF_INET6 && !in_addr_equal(AF_INET6, &p->destination, (union in_addr_union*) &LLMNR_MULTICAST_IPV6_ADDRESS)) | |
722 | return; | |
723 | } | |
724 | ||
623a4c97 LP |
725 | r = dns_packet_extract(p); |
726 | if (r < 0) { | |
b30bf55d | 727 | log_debug_errno(r, "Failed to extract resource records from incoming packet: %m"); |
623a4c97 LP |
728 | return; |
729 | } | |
730 | ||
8b757a38 | 731 | if (DNS_PACKET_LLMNR_C(p)) { |
a4076574 LP |
732 | /* Somebody notified us about a possible conflict */ |
733 | dns_scope_verify_conflicts(s, p); | |
ea917db9 LP |
734 | return; |
735 | } | |
736 | ||
501e8eb0 | 737 | assert(dns_question_size(p->question) == 1); |
5032b16d LP |
738 | key = p->question->keys[0]; |
739 | ||
97ebebbc | 740 | r = dns_zone_lookup(&s->zone, key, 0, &answer, &soa, &tentative); |
623a4c97 | 741 | if (r < 0) { |
da927ba9 | 742 | log_debug_errno(r, "Failed to lookup key: %m"); |
623a4c97 LP |
743 | return; |
744 | } | |
745 | if (r == 0) | |
746 | return; | |
747 | ||
fcf57f9c LP |
748 | if (answer) |
749 | dns_answer_order_by_scope(answer, in_addr_is_link_local(p->family, &p->sender) > 0); | |
af93291c | 750 | |
ec2c5e43 | 751 | r = dns_scope_make_reply_packet(s, DNS_PACKET_ID(p), DNS_RCODE_SUCCESS, p->question, answer, soa, tentative, &reply); |
623a4c97 | 752 | if (r < 0) { |
da927ba9 | 753 | log_debug_errno(r, "Failed to build reply packet: %m"); |
623a4c97 LP |
754 | return; |
755 | } | |
756 | ||
b30bf55d | 757 | if (stream) { |
623a4c97 | 758 | r = dns_stream_write_packet(stream, reply); |
b30bf55d LP |
759 | if (r < 0) { |
760 | log_debug_errno(r, "Failed to enqueue reply packet: %m"); | |
761 | return; | |
762 | } | |
763 | ||
764 | /* Let's take an extra reference on this stream, so that it stays around after returning. The reference | |
765 | * will be dangling until the stream is disconnected, and the default completion handler of the stream | |
766 | * will then unref the stream and destroy it */ | |
767 | if (DNS_STREAM_QUEUED(stream)) | |
768 | dns_stream_ref(stream); | |
769 | } else { | |
770 | int fd; | |
771 | ||
7994ac1d | 772 | if (!ratelimit_below(&s->ratelimit)) |
aea2429d LP |
773 | return; |
774 | ||
623a4c97 LP |
775 | if (p->family == AF_INET) |
776 | fd = manager_llmnr_ipv4_udp_fd(s->manager); | |
777 | else if (p->family == AF_INET6) | |
778 | fd = manager_llmnr_ipv6_udp_fd(s->manager); | |
779 | else { | |
780 | log_debug("Unknown protocol"); | |
781 | return; | |
782 | } | |
783 | if (fd < 0) { | |
da927ba9 | 784 | log_debug_errno(fd, "Failed to get reply socket: %m"); |
623a4c97 LP |
785 | return; |
786 | } | |
787 | ||
6e068472 LP |
788 | /* Note that we always immediately reply to all LLMNR |
789 | * requests, and do not wait any time, since we | |
790 | * verified uniqueness for all records. Also see RFC | |
791 | * 4795, Section 2.7 */ | |
792 | ||
b30bf55d LP |
793 | r = manager_send(s->manager, fd, p->ifindex, p->family, &p->sender, p->sender_port, NULL, reply); |
794 | if (r < 0) { | |
795 | log_debug_errno(r, "Failed to send reply packet: %m"); | |
796 | return; | |
797 | } | |
623a4c97 LP |
798 | } |
799 | } | |
ec2c5e43 | 800 | |
f52e61da | 801 | DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key, bool cache_ok) { |
ec2c5e43 LP |
802 | DnsTransaction *t; |
803 | ||
804 | assert(scope); | |
f52e61da | 805 | assert(key); |
ec2c5e43 | 806 | |
da0c630e LP |
807 | /* Try to find an ongoing transaction that is a equal to the |
808 | * specified question */ | |
f9ebb22a | 809 | t = hashmap_get(scope->transactions_by_key, key); |
4a46ed1b LP |
810 | if (!t) |
811 | return NULL; | |
dc4d47e2 | 812 | |
da0c630e LP |
813 | /* Refuse reusing transactions that completed based on cached |
814 | * data instead of a real packet, if that's requested. */ | |
815 | if (!cache_ok && | |
3bbdc31d | 816 | IN_SET(t->state, DNS_TRANSACTION_SUCCESS, DNS_TRANSACTION_RCODE_FAILURE) && |
c3bc53e6 | 817 | t->answer_source != DNS_TRANSACTION_NETWORK) |
da0c630e | 818 | return NULL; |
ec2c5e43 | 819 | |
da0c630e | 820 | return t; |
ec2c5e43 | 821 | } |
a4076574 LP |
822 | |
823 | static int dns_scope_make_conflict_packet( | |
824 | DnsScope *s, | |
825 | DnsResourceRecord *rr, | |
826 | DnsPacket **ret) { | |
827 | ||
828 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
829 | int r; | |
830 | ||
831 | assert(s); | |
832 | assert(rr); | |
833 | assert(ret); | |
834 | ||
51027656 | 835 | r = dns_packet_new(&p, s->protocol, 0, DNS_PACKET_SIZE_MAX); |
a4076574 LP |
836 | if (r < 0) |
837 | return r; | |
838 | ||
839 | DNS_PACKET_HEADER(p)->flags = htobe16(DNS_PACKET_MAKE_FLAGS( | |
840 | 0 /* qr */, | |
841 | 0 /* opcode */, | |
842 | 1 /* conflict */, | |
843 | 0 /* tc */, | |
844 | 0 /* t */, | |
845 | 0 /* (ra) */, | |
846 | 0 /* (ad) */, | |
847 | 0 /* (cd) */, | |
848 | 0)); | |
fe2dfc8b DM |
849 | |
850 | /* For mDNS, the transaction ID should always be 0 */ | |
851 | if (s->protocol != DNS_PROTOCOL_MDNS) | |
852 | random_bytes(&DNS_PACKET_HEADER(p)->id, sizeof(uint16_t)); | |
853 | ||
a4076574 LP |
854 | DNS_PACKET_HEADER(p)->qdcount = htobe16(1); |
855 | DNS_PACKET_HEADER(p)->arcount = htobe16(1); | |
856 | ||
58ab31d5 | 857 | r = dns_packet_append_key(p, rr->key, 0, NULL); |
a4076574 LP |
858 | if (r < 0) |
859 | return r; | |
860 | ||
58ab31d5 | 861 | r = dns_packet_append_rr(p, rr, 0, NULL, NULL); |
a4076574 LP |
862 | if (r < 0) |
863 | return r; | |
864 | ||
1cc6c93a | 865 | *ret = TAKE_PTR(p); |
a4076574 LP |
866 | |
867 | return 0; | |
868 | } | |
869 | ||
870 | static int on_conflict_dispatch(sd_event_source *es, usec_t usec, void *userdata) { | |
871 | DnsScope *scope = userdata; | |
872 | int r; | |
873 | ||
874 | assert(es); | |
875 | assert(scope); | |
876 | ||
877 | scope->conflict_event_source = sd_event_source_unref(scope->conflict_event_source); | |
878 | ||
879 | for (;;) { | |
432d108c | 880 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; |
a4076574 LP |
881 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL; |
882 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
883 | ||
432d108c DR |
884 | key = ordered_hashmap_first_key(scope->conflict_queue); |
885 | if (!key) | |
a4076574 LP |
886 | break; |
887 | ||
432d108c DR |
888 | rr = ordered_hashmap_remove(scope->conflict_queue, key); |
889 | assert(rr); | |
890 | ||
a4076574 LP |
891 | r = dns_scope_make_conflict_packet(scope, rr, &p); |
892 | if (r < 0) { | |
da927ba9 | 893 | log_error_errno(r, "Failed to make conflict packet: %m"); |
a4076574 LP |
894 | return 0; |
895 | } | |
896 | ||
519ef046 | 897 | r = dns_scope_emit_udp(scope, -1, p); |
a4076574 | 898 | if (r < 0) |
da927ba9 | 899 | log_debug_errno(r, "Failed to send conflict packet: %m"); |
a4076574 LP |
900 | } |
901 | ||
902 | return 0; | |
903 | } | |
904 | ||
905 | int dns_scope_notify_conflict(DnsScope *scope, DnsResourceRecord *rr) { | |
906 | usec_t jitter; | |
907 | int r; | |
908 | ||
909 | assert(scope); | |
910 | assert(rr); | |
911 | ||
912 | /* We don't send these queries immediately. Instead, we queue | |
913 | * them, and send them after some jitter delay. */ | |
1e43061b | 914 | r = ordered_hashmap_ensure_allocated(&scope->conflict_queue, &dns_resource_key_hash_ops); |
a4076574 LP |
915 | if (r < 0) { |
916 | log_oom(); | |
917 | return r; | |
918 | } | |
919 | ||
920 | /* We only place one RR per key in the conflict | |
921 | * messages, not all of them. That should be enough to | |
922 | * indicate where there might be a conflict */ | |
1e43061b | 923 | r = ordered_hashmap_put(scope->conflict_queue, rr->key, rr); |
4c701096 | 924 | if (IN_SET(r, 0, -EEXIST)) |
a4076574 | 925 | return 0; |
f647962d MS |
926 | if (r < 0) |
927 | return log_debug_errno(r, "Failed to queue conflicting RR: %m"); | |
a4076574 | 928 | |
432d108c | 929 | dns_resource_key_ref(rr->key); |
a4076574 LP |
930 | dns_resource_record_ref(rr); |
931 | ||
932 | if (scope->conflict_event_source) | |
933 | return 0; | |
934 | ||
935 | random_bytes(&jitter, sizeof(jitter)); | |
936 | jitter %= LLMNR_JITTER_INTERVAL_USEC; | |
937 | ||
938 | r = sd_event_add_time(scope->manager->event, | |
939 | &scope->conflict_event_source, | |
940 | clock_boottime_or_monotonic(), | |
941 | now(clock_boottime_or_monotonic()) + jitter, | |
942 | LLMNR_JITTER_INTERVAL_USEC, | |
943 | on_conflict_dispatch, scope); | |
f647962d MS |
944 | if (r < 0) |
945 | return log_debug_errno(r, "Failed to add conflict dispatch event: %m"); | |
a4076574 | 946 | |
aa4a9deb LP |
947 | (void) sd_event_source_set_description(scope->conflict_event_source, "scope-conflict"); |
948 | ||
a4076574 LP |
949 | return 0; |
950 | } | |
951 | ||
952 | void dns_scope_check_conflicts(DnsScope *scope, DnsPacket *p) { | |
c1227a18 | 953 | DnsResourceRecord *rr; |
a4076574 LP |
954 | int r; |
955 | ||
956 | assert(scope); | |
957 | assert(p); | |
958 | ||
53fda2bb | 959 | if (!IN_SET(p->protocol, DNS_PROTOCOL_LLMNR, DNS_PROTOCOL_MDNS)) |
a4076574 LP |
960 | return; |
961 | ||
962 | if (DNS_PACKET_RRCOUNT(p) <= 0) | |
963 | return; | |
964 | ||
53fda2bb DR |
965 | if (p->protocol == DNS_PROTOCOL_LLMNR) { |
966 | if (DNS_PACKET_LLMNR_C(p) != 0) | |
967 | return; | |
a4076574 | 968 | |
53fda2bb DR |
969 | if (DNS_PACKET_LLMNR_T(p) != 0) |
970 | return; | |
971 | } | |
a4076574 LP |
972 | |
973 | if (manager_our_packet(scope->manager, p)) | |
974 | return; | |
975 | ||
976 | r = dns_packet_extract(p); | |
977 | if (r < 0) { | |
da927ba9 | 978 | log_debug_errno(r, "Failed to extract packet: %m"); |
a4076574 LP |
979 | return; |
980 | } | |
981 | ||
982 | log_debug("Checking for conflicts..."); | |
983 | ||
c1227a18 | 984 | DNS_ANSWER_FOREACH(rr, p->answer) { |
cfcc8dcc | 985 | /* No conflict if it is DNS-SD RR used for service enumeration. */ |
c1227a18 | 986 | if (dns_resource_key_is_dnssd_ptr(rr->key)) |
cfcc8dcc DR |
987 | continue; |
988 | ||
a4076574 LP |
989 | /* Check for conflicts against the local zone. If we |
990 | * found one, we won't check any further */ | |
c1227a18 | 991 | r = dns_zone_check_conflicts(&scope->zone, rr); |
a4076574 LP |
992 | if (r != 0) |
993 | continue; | |
994 | ||
995 | /* Check for conflicts against the local cache. If so, | |
996 | * send out an advisory query, to inform everybody */ | |
c1227a18 | 997 | r = dns_cache_check_conflicts(&scope->cache, rr, p->family, &p->sender); |
a4076574 LP |
998 | if (r <= 0) |
999 | continue; | |
1000 | ||
c1227a18 | 1001 | dns_scope_notify_conflict(scope, rr); |
a4076574 LP |
1002 | } |
1003 | } | |
4d506d6b LP |
1004 | |
1005 | void dns_scope_dump(DnsScope *s, FILE *f) { | |
1006 | assert(s); | |
1007 | ||
1008 | if (!f) | |
1009 | f = stdout; | |
1010 | ||
1011 | fputs("[Scope protocol=", f); | |
1012 | fputs(dns_protocol_to_string(s->protocol), f); | |
1013 | ||
1014 | if (s->link) { | |
1015 | fputs(" interface=", f); | |
1016 | fputs(s->link->name, f); | |
1017 | } | |
1018 | ||
1019 | if (s->family != AF_UNSPEC) { | |
1020 | fputs(" family=", f); | |
1021 | fputs(af_to_name(s->family), f); | |
1022 | } | |
1023 | ||
1024 | fputs("]\n", f); | |
1025 | ||
1026 | if (!dns_zone_is_empty(&s->zone)) { | |
1027 | fputs("ZONE:\n", f); | |
1028 | dns_zone_dump(&s->zone, f); | |
1029 | } | |
1030 | ||
1031 | if (!dns_cache_is_empty(&s->cache)) { | |
1032 | fputs("CACHE:\n", f); | |
1033 | dns_cache_dump(&s->cache, f); | |
1034 | } | |
1035 | } | |
a51c1048 LP |
1036 | |
1037 | DnsSearchDomain *dns_scope_get_search_domains(DnsScope *s) { | |
801ad6a6 LP |
1038 | assert(s); |
1039 | ||
a51c1048 LP |
1040 | if (s->protocol != DNS_PROTOCOL_DNS) |
1041 | return NULL; | |
1042 | ||
1043 | if (s->link) | |
1044 | return s->link->search_domains; | |
1045 | ||
28b9b764 | 1046 | return s->manager->search_domains; |
801ad6a6 LP |
1047 | } |
1048 | ||
dc477e73 | 1049 | bool dns_scope_name_needs_search_domain(DnsScope *s, const char *name) { |
801ad6a6 LP |
1050 | assert(s); |
1051 | ||
1052 | if (s->protocol != DNS_PROTOCOL_DNS) | |
dc477e73 | 1053 | return false; |
801ad6a6 | 1054 | |
dc477e73 | 1055 | return dns_name_is_single_label(name); |
801ad6a6 | 1056 | } |
edbcc1fd LP |
1057 | |
1058 | bool dns_scope_network_good(DnsScope *s) { | |
edbcc1fd LP |
1059 | /* Checks whether the network is in good state for lookups on this scope. For mDNS/LLMNR/Classic DNS scopes |
1060 | * bound to links this is easy, as they don't even exist if the link isn't in a suitable state. For the global | |
1061 | * DNS scope we check whether there are any links that are up and have an address. */ | |
1062 | ||
1063 | if (s->link) | |
1064 | return true; | |
1065 | ||
011696f7 | 1066 | return manager_routable(s->manager, AF_UNSPEC); |
edbcc1fd | 1067 | } |
97ebebbc LP |
1068 | |
1069 | int dns_scope_ifindex(DnsScope *s) { | |
1070 | assert(s); | |
1071 | ||
1072 | if (s->link) | |
1073 | return s->link->ifindex; | |
1074 | ||
1075 | return 0; | |
1076 | } | |
53fda2bb DR |
1077 | |
1078 | static int on_announcement_timeout(sd_event_source *s, usec_t usec, void *userdata) { | |
1079 | DnsScope *scope = userdata; | |
1080 | ||
1081 | assert(s); | |
1082 | ||
1083 | scope->announce_event_source = sd_event_source_unref(scope->announce_event_source); | |
1084 | ||
1a63fc54 | 1085 | (void) dns_scope_announce(scope, false); |
53fda2bb DR |
1086 | return 0; |
1087 | } | |
1088 | ||
1a63fc54 | 1089 | int dns_scope_announce(DnsScope *scope, bool goodbye) { |
53fda2bb DR |
1090 | _cleanup_(dns_answer_unrefp) DnsAnswer *answer = NULL; |
1091 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
a2bf8a19 DR |
1092 | _cleanup_set_free_ Set *types = NULL; |
1093 | DnsTransaction *t; | |
400f54fb | 1094 | DnsZoneItem *z, *i; |
a2bf8a19 DR |
1095 | unsigned size = 0; |
1096 | Iterator iterator; | |
1097 | char *service_type; | |
53fda2bb DR |
1098 | int r; |
1099 | ||
1100 | if (!scope) | |
1a63fc54 | 1101 | return 0; |
53fda2bb DR |
1102 | |
1103 | if (scope->protocol != DNS_PROTOCOL_MDNS) | |
1a63fc54 | 1104 | return 0; |
53fda2bb | 1105 | |
a2bf8a19 DR |
1106 | /* Check if we're done with probing. */ |
1107 | LIST_FOREACH(transactions_by_scope, t, scope->transactions) | |
1108 | if (DNS_TRANSACTION_IS_LIVE(t->state)) | |
1109 | return 0; | |
1110 | ||
e7c1b0e4 DR |
1111 | /* Check if there're services pending conflict resolution. */ |
1112 | if (manager_next_dnssd_names(scope->manager)) | |
1113 | return 0; /* we reach this point only if changing hostname didn't help */ | |
1114 | ||
a2bf8a19 DR |
1115 | /* Calculate answer's size. */ |
1116 | HASHMAP_FOREACH(z, scope->zone.by_key, iterator) { | |
1117 | if (z->state != DNS_ZONE_ITEM_ESTABLISHED) | |
1118 | continue; | |
1119 | ||
1120 | if (z->rr->key->type == DNS_TYPE_PTR && | |
1121 | !dns_zone_contains_name(&scope->zone, z->rr->ptr.name)) { | |
1122 | char key_str[DNS_RESOURCE_KEY_STRING_MAX]; | |
1123 | ||
1124 | 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)); | |
1125 | z->state = DNS_ZONE_ITEM_WITHDRAWN; | |
1126 | continue; | |
1127 | } | |
1128 | ||
1129 | /* Collect service types for _services._dns-sd._udp.local RRs in a set */ | |
1130 | if (!scope->announced && | |
1131 | dns_resource_key_is_dnssd_ptr(z->rr->key)) { | |
1132 | if (!set_contains(types, dns_resource_key_name(z->rr->key))) { | |
1133 | r = set_ensure_allocated(&types, &dns_name_hash_ops); | |
1134 | if (r < 0) | |
1135 | return log_debug_errno(r, "Failed to allocate set: %m"); | |
1136 | ||
1137 | r = set_put(types, dns_resource_key_name(z->rr->key)); | |
1138 | if (r < 0) | |
1139 | return log_debug_errno(r, "Failed to add item to set: %m"); | |
1140 | } | |
1141 | } | |
1142 | ||
400f54fb DR |
1143 | LIST_FOREACH(by_key, i, z) |
1144 | size++; | |
a2bf8a19 DR |
1145 | } |
1146 | ||
1147 | answer = dns_answer_new(size + set_size(types)); | |
1a63fc54 LP |
1148 | if (!answer) |
1149 | return log_oom(); | |
1150 | ||
a2bf8a19 | 1151 | /* Second iteration, actually add RRs to the answer. */ |
400f54fb DR |
1152 | HASHMAP_FOREACH(z, scope->zone.by_key, iterator) |
1153 | LIST_FOREACH (by_key, i, z) { | |
1154 | DnsAnswerFlags flags; | |
a2bf8a19 | 1155 | |
400f54fb DR |
1156 | if (i->state != DNS_ZONE_ITEM_ESTABLISHED) |
1157 | continue; | |
a2bf8a19 | 1158 | |
400f54fb DR |
1159 | if (dns_resource_key_is_dnssd_ptr(i->rr->key)) |
1160 | flags = goodbye ? DNS_ANSWER_GOODBYE : 0; | |
1161 | else | |
1162 | flags = goodbye ? (DNS_ANSWER_GOODBYE|DNS_ANSWER_CACHE_FLUSH) : DNS_ANSWER_CACHE_FLUSH; | |
a2bf8a19 | 1163 | |
400f54fb DR |
1164 | r = dns_answer_add(answer, i->rr, 0 , flags); |
1165 | if (r < 0) | |
1166 | return log_debug_errno(r, "Failed to add RR to announce: %m"); | |
1167 | } | |
a2bf8a19 DR |
1168 | |
1169 | /* Since all the active services are in the zone make them discoverable now. */ | |
1170 | SET_FOREACH(service_type, types, iterator) { | |
1171 | _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr; | |
1172 | ||
1173 | rr = dns_resource_record_new_full(DNS_CLASS_IN, DNS_TYPE_PTR, | |
1174 | "_services._dns-sd._udp.local"); | |
1175 | rr->ptr.name = strdup(service_type); | |
1176 | rr->ttl = MDNS_DEFAULT_TTL; | |
1177 | ||
1178 | r = dns_zone_put(&scope->zone, scope, rr, false); | |
1a63fc54 | 1179 | if (r < 0) |
a2bf8a19 | 1180 | log_warning_errno(r, "Failed to add DNS-SD PTR record to MDNS zone: %m"); |
1a63fc54 | 1181 | |
a2bf8a19 | 1182 | r = dns_answer_add(answer, rr, 0 , 0); |
1a63fc54 | 1183 | if (r < 0) |
a2bf8a19 | 1184 | return log_debug_errno(r, "Failed to add RR to announce: %m"); |
53fda2bb DR |
1185 | } |
1186 | ||
1187 | if (dns_answer_isempty(answer)) | |
1a63fc54 | 1188 | return 0; |
53fda2bb DR |
1189 | |
1190 | r = dns_scope_make_reply_packet(scope, 0, DNS_RCODE_SUCCESS, NULL, answer, NULL, false, &p); | |
1a63fc54 LP |
1191 | if (r < 0) |
1192 | return log_debug_errno(r, "Failed to build reply packet: %m"); | |
1193 | ||
53fda2bb | 1194 | r = dns_scope_emit_udp(scope, -1, p); |
1a63fc54 LP |
1195 | if (r < 0) |
1196 | return log_debug_errno(r, "Failed to send reply packet: %m"); | |
53fda2bb DR |
1197 | |
1198 | /* In section 8.3 of RFC6762: "The Multicast DNS responder MUST send at least two unsolicited | |
1199 | * responses, one second apart." */ | |
1200 | if (!scope->announced) { | |
1201 | usec_t ts; | |
1202 | ||
1203 | scope->announced = true; | |
1204 | ||
1205 | assert_se(sd_event_now(scope->manager->event, clock_boottime_or_monotonic(), &ts) >= 0); | |
1206 | ts += MDNS_ANNOUNCE_DELAY; | |
1207 | ||
1208 | r = sd_event_add_time( | |
1209 | scope->manager->event, | |
1210 | &scope->announce_event_source, | |
1211 | clock_boottime_or_monotonic(), | |
1212 | ts, | |
1213 | MDNS_JITTER_RANGE_USEC, | |
1214 | on_announcement_timeout, scope); | |
1215 | if (r < 0) | |
1a63fc54 | 1216 | return log_debug_errno(r, "Failed to schedule second announcement: %m"); |
19fee3ef LP |
1217 | |
1218 | (void) sd_event_source_set_description(scope->announce_event_source, "mdns-announce"); | |
53fda2bb | 1219 | } |
1a63fc54 LP |
1220 | |
1221 | return 0; | |
53fda2bb | 1222 | } |
6db6a464 DR |
1223 | |
1224 | int dns_scope_add_dnssd_services(DnsScope *scope) { | |
1225 | Iterator i; | |
1226 | DnssdService *service; | |
400f54fb | 1227 | DnssdTxtData *txt_data; |
6db6a464 DR |
1228 | int r; |
1229 | ||
1230 | assert(scope); | |
1231 | ||
1232 | if (hashmap_size(scope->manager->dnssd_services) == 0) | |
1233 | return 0; | |
1234 | ||
1235 | scope->announced = false; | |
1236 | ||
1237 | HASHMAP_FOREACH(service, scope->manager->dnssd_services, i) { | |
c3036641 DR |
1238 | service->withdrawn = false; |
1239 | ||
6db6a464 DR |
1240 | r = dns_zone_put(&scope->zone, scope, service->ptr_rr, false); |
1241 | if (r < 0) | |
1242 | log_warning_errno(r, "Failed to add PTR record to MDNS zone: %m"); | |
1243 | ||
1244 | r = dns_zone_put(&scope->zone, scope, service->srv_rr, true); | |
1245 | if (r < 0) | |
1246 | log_warning_errno(r, "Failed to add SRV record to MDNS zone: %m"); | |
1247 | ||
400f54fb DR |
1248 | LIST_FOREACH(items, txt_data, service->txt_data_items) { |
1249 | r = dns_zone_put(&scope->zone, scope, txt_data->rr, true); | |
1250 | if (r < 0) | |
1251 | log_warning_errno(r, "Failed to add TXT record to MDNS zone: %m"); | |
1252 | } | |
6db6a464 DR |
1253 | } |
1254 | ||
1255 | return 0; | |
1256 | } | |
1257 | ||
1258 | int dns_scope_remove_dnssd_services(DnsScope *scope) { | |
1259 | _cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL; | |
1260 | Iterator i; | |
1261 | DnssdService *service; | |
400f54fb | 1262 | DnssdTxtData *txt_data; |
6db6a464 DR |
1263 | int r; |
1264 | ||
1265 | assert(scope); | |
1266 | ||
1267 | key = dns_resource_key_new(DNS_CLASS_IN, DNS_TYPE_PTR, | |
1268 | "_services._dns-sd._udp.local"); | |
1269 | if (!key) | |
1270 | return log_oom(); | |
1271 | ||
1272 | r = dns_zone_remove_rrs_by_key(&scope->zone, key); | |
1273 | if (r < 0) | |
1274 | return r; | |
1275 | ||
1276 | HASHMAP_FOREACH(service, scope->manager->dnssd_services, i) { | |
1277 | dns_zone_remove_rr(&scope->zone, service->ptr_rr); | |
1278 | dns_zone_remove_rr(&scope->zone, service->srv_rr); | |
400f54fb DR |
1279 | LIST_FOREACH(items, txt_data, service->txt_data_items) |
1280 | dns_zone_remove_rr(&scope->zone, txt_data->rr); | |
6db6a464 DR |
1281 | } |
1282 | ||
1283 | return 0; | |
1284 | } |