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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
5f402ae8 | 2 | |
5f402ae8 | 3 | #include <netinet/in.h> |
cf0fbc49 | 4 | #include <resolv.h> |
5f402ae8 | 5 | |
3ffd4af2 | 6 | #include "fd-util.h" |
5f402ae8 | 7 | #include "resolved-llmnr.h" |
3ffd4af2 | 8 | #include "resolved-manager.h" |
5f402ae8 DM |
9 | |
10 | void manager_llmnr_stop(Manager *m) { | |
11 | assert(m); | |
12 | ||
13 | m->llmnr_ipv4_udp_event_source = sd_event_source_unref(m->llmnr_ipv4_udp_event_source); | |
14 | m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd); | |
15 | ||
16 | m->llmnr_ipv6_udp_event_source = sd_event_source_unref(m->llmnr_ipv6_udp_event_source); | |
17 | m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd); | |
18 | ||
19 | m->llmnr_ipv4_tcp_event_source = sd_event_source_unref(m->llmnr_ipv4_tcp_event_source); | |
20 | m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd); | |
21 | ||
22 | m->llmnr_ipv6_tcp_event_source = sd_event_source_unref(m->llmnr_ipv6_tcp_event_source); | |
23 | m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd); | |
24 | } | |
25 | ||
26 | int manager_llmnr_start(Manager *m) { | |
27 | int r; | |
28 | ||
29 | assert(m); | |
30 | ||
af49ca27 | 31 | if (m->llmnr_support == RESOLVE_SUPPORT_NO) |
5f402ae8 DM |
32 | return 0; |
33 | ||
34 | r = manager_llmnr_ipv4_udp_fd(m); | |
35 | if (r == -EADDRINUSE) | |
36 | goto eaddrinuse; | |
37 | if (r < 0) | |
38 | return r; | |
39 | ||
40 | r = manager_llmnr_ipv4_tcp_fd(m); | |
41 | if (r == -EADDRINUSE) | |
42 | goto eaddrinuse; | |
43 | if (r < 0) | |
44 | return r; | |
45 | ||
46 | if (socket_ipv6_is_supported()) { | |
47 | r = manager_llmnr_ipv6_udp_fd(m); | |
48 | if (r == -EADDRINUSE) | |
49 | goto eaddrinuse; | |
50 | if (r < 0) | |
51 | return r; | |
52 | ||
53 | r = manager_llmnr_ipv6_tcp_fd(m); | |
54 | if (r == -EADDRINUSE) | |
55 | goto eaddrinuse; | |
56 | if (r < 0) | |
57 | return r; | |
58 | } | |
59 | ||
60 | return 0; | |
61 | ||
62 | eaddrinuse: | |
007ef0a2 | 63 | log_warning("Another LLMNR responder prohibits binding the socket to the same port. Turning off LLMNR support."); |
af49ca27 | 64 | m->llmnr_support = RESOLVE_SUPPORT_NO; |
5f402ae8 DM |
65 | manager_llmnr_stop(m); |
66 | ||
67 | return 0; | |
68 | } | |
69 | ||
70 | static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
71 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; | |
72 | DnsTransaction *t = NULL; | |
73 | Manager *m = userdata; | |
74 | DnsScope *scope; | |
75 | int r; | |
76 | ||
b30bf55d LP |
77 | assert(s); |
78 | assert(fd >= 0); | |
79 | assert(m); | |
80 | ||
5f402ae8 DM |
81 | r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p); |
82 | if (r <= 0) | |
83 | return r; | |
84 | ||
6cae1ebe LP |
85 | if (manager_our_packet(m, p)) |
86 | return 0; | |
87 | ||
5f402ae8 | 88 | scope = manager_find_scope(m, p); |
f1b1a5c4 LP |
89 | if (!scope) { |
90 | log_debug("Got LLMNR UDP packet on unknown scope. Ignoring."); | |
91 | return 0; | |
92 | } | |
93 | ||
94 | if (dns_packet_validate_reply(p) > 0) { | |
b30bf55d | 95 | log_debug("Got LLMNR UDP reply packet for id %u", DNS_PACKET_ID(p)); |
5f402ae8 DM |
96 | |
97 | dns_scope_check_conflicts(scope, p); | |
98 | ||
99 | t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p))); | |
100 | if (t) | |
101 | dns_transaction_process_reply(t, p); | |
102 | ||
103 | } else if (dns_packet_validate_query(p) > 0) { | |
b30bf55d | 104 | log_debug("Got LLMNR UDP query packet for id %u", DNS_PACKET_ID(p)); |
5f402ae8 DM |
105 | |
106 | dns_scope_process_query(scope, NULL, p); | |
107 | } else | |
2c6bf498 | 108 | log_debug("Invalid LLMNR UDP packet, ignoring."); |
5f402ae8 DM |
109 | |
110 | return 0; | |
111 | } | |
112 | ||
113 | int manager_llmnr_ipv4_udp_fd(Manager *m) { | |
114 | union sockaddr_union sa = { | |
115 | .in.sin_family = AF_INET, | |
22a37591 | 116 | .in.sin_port = htobe16(LLMNR_PORT), |
5f402ae8 | 117 | }; |
3f548fff | 118 | _cleanup_close_ int s = -1; |
5f402ae8 DM |
119 | int r; |
120 | ||
121 | assert(m); | |
122 | ||
123 | if (m->llmnr_ipv4_udp_fd >= 0) | |
124 | return m->llmnr_ipv4_udp_fd; | |
125 | ||
3f548fff YW |
126 | s = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
127 | if (s < 0) | |
007ef0a2 | 128 | return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to create socket: %m"); |
5f402ae8 DM |
129 | |
130 | /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ | |
3f548fff YW |
131 | r = setsockopt_int(s, IPPROTO_IP, IP_TTL, 255); |
132 | if (r < 0) | |
133 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_TTL: %m"); | |
5f402ae8 | 134 | |
3f548fff YW |
135 | r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_TTL, 255); |
136 | if (r < 0) | |
137 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_TTL: %m"); | |
5f402ae8 | 138 | |
3f548fff YW |
139 | r = setsockopt_int(s, IPPROTO_IP, IP_MULTICAST_LOOP, true); |
140 | if (r < 0) | |
141 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MULTICAST_LOOP: %m"); | |
5f402ae8 | 142 | |
3f548fff YW |
143 | r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true); |
144 | if (r < 0) | |
145 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_PKTINFO: %m"); | |
5f402ae8 | 146 | |
3f548fff YW |
147 | r = setsockopt_int(s, IPPROTO_IP, IP_RECVTTL, true); |
148 | if (r < 0) | |
149 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_RECVTTL: %m"); | |
5f402ae8 DM |
150 | |
151 | /* Disable Don't-Fragment bit in the IP header */ | |
3f548fff YW |
152 | r = setsockopt_int(s, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT); |
153 | if (r < 0) | |
154 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set IP_MTU_DISCOVER: %m"); | |
5f402ae8 | 155 | |
007ef0a2 | 156 | /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ |
3f548fff | 157 | r = bind(s, &sa.sa, sizeof(sa.in)); |
5f402ae8 | 158 | if (r < 0) { |
3f548fff YW |
159 | if (errno != EADDRINUSE) |
160 | return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m"); | |
007ef0a2 YW |
161 | |
162 | log_warning("LLMNR-IPv4(UDP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); | |
163 | ||
164 | /* try again with SO_REUSEADDR */ | |
3f548fff YW |
165 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
166 | if (r < 0) | |
167 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m"); | |
168 | ||
169 | r = bind(s, &sa.sa, sizeof(sa.in)); | |
170 | if (r < 0) | |
171 | return log_error_errno(errno, "LLMNR-IPv4(UDP): Failed to bind socket: %m"); | |
007ef0a2 YW |
172 | } else { |
173 | /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ | |
3f548fff YW |
174 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
175 | if (r < 0) | |
176 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to set SO_REUSEADDR: %m"); | |
5f402ae8 DM |
177 | } |
178 | ||
3f548fff | 179 | r = sd_event_add_io(m->event, &m->llmnr_ipv4_udp_event_source, s, EPOLLIN, on_llmnr_packet, m); |
5f402ae8 | 180 | if (r < 0) |
3f548fff | 181 | return log_error_errno(r, "LLMNR-IPv4(UDP): Failed to create event source: %m"); |
5f402ae8 | 182 | |
aa4a9deb LP |
183 | (void) sd_event_source_set_description(m->llmnr_ipv4_udp_event_source, "llmnr-ipv4-udp"); |
184 | ||
3f548fff | 185 | return m->llmnr_ipv4_udp_fd = TAKE_FD(s); |
5f402ae8 DM |
186 | } |
187 | ||
188 | int manager_llmnr_ipv6_udp_fd(Manager *m) { | |
189 | union sockaddr_union sa = { | |
190 | .in6.sin6_family = AF_INET6, | |
22a37591 | 191 | .in6.sin6_port = htobe16(LLMNR_PORT), |
5f402ae8 | 192 | }; |
3f548fff | 193 | _cleanup_close_ int s = -1; |
5f402ae8 DM |
194 | int r; |
195 | ||
196 | assert(m); | |
197 | ||
198 | if (m->llmnr_ipv6_udp_fd >= 0) | |
199 | return m->llmnr_ipv6_udp_fd; | |
200 | ||
3f548fff YW |
201 | s = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
202 | if (s < 0) | |
007ef0a2 | 203 | return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to create socket: %m"); |
5f402ae8 | 204 | |
3f548fff YW |
205 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, 255); |
206 | if (r < 0) | |
207 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_UNICAST_HOPS: %m"); | |
5f402ae8 DM |
208 | |
209 | /* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */ | |
3f548fff YW |
210 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 255); |
211 | if (r < 0) | |
212 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_HOPS: %m"); | |
5f402ae8 | 213 | |
3f548fff YW |
214 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, true); |
215 | if (r < 0) | |
216 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_MULTICAST_LOOP: %m"); | |
5f402ae8 | 217 | |
3f548fff YW |
218 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true); |
219 | if (r < 0) | |
220 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_V6ONLY: %m"); | |
5f402ae8 | 221 | |
3f548fff YW |
222 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, true); |
223 | if (r < 0) | |
224 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVPKTINFO: %m"); | |
5f402ae8 | 225 | |
3f548fff YW |
226 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true); |
227 | if (r < 0) | |
228 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set IPV6_RECVHOPLIMIT: %m"); | |
5f402ae8 | 229 | |
007ef0a2 | 230 | /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ |
3f548fff | 231 | r = bind(s, &sa.sa, sizeof(sa.in6)); |
5f402ae8 | 232 | if (r < 0) { |
3f548fff YW |
233 | if (errno != EADDRINUSE) |
234 | return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m"); | |
007ef0a2 YW |
235 | |
236 | log_warning("LLMNR-IPv6(UDP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); | |
237 | ||
238 | /* try again with SO_REUSEADDR */ | |
3f548fff YW |
239 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
240 | if (r < 0) | |
241 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m"); | |
242 | ||
243 | r = bind(s, &sa.sa, sizeof(sa.in6)); | |
244 | if (r < 0) | |
245 | return log_error_errno(errno, "LLMNR-IPv6(UDP): Failed to bind socket: %m"); | |
007ef0a2 YW |
246 | } else { |
247 | /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ | |
3f548fff YW |
248 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
249 | if (r < 0) | |
250 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to set SO_REUSEADDR: %m"); | |
5f402ae8 DM |
251 | } |
252 | ||
3f548fff | 253 | r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, s, EPOLLIN, on_llmnr_packet, m); |
35908b98 | 254 | if (r < 0) |
3f548fff | 255 | return log_error_errno(r, "LLMNR-IPv6(UDP): Failed to create event source: %m"); |
5f402ae8 | 256 | |
aa4a9deb LP |
257 | (void) sd_event_source_set_description(m->llmnr_ipv6_udp_event_source, "llmnr-ipv6-udp"); |
258 | ||
3f548fff | 259 | return m->llmnr_ipv6_udp_fd = TAKE_FD(s); |
5f402ae8 DM |
260 | } |
261 | ||
262 | static int on_llmnr_stream_packet(DnsStream *s) { | |
aa337a5e | 263 | _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; |
5f402ae8 DM |
264 | DnsScope *scope; |
265 | ||
266 | assert(s); | |
267 | ||
aa337a5e LP |
268 | p = dns_stream_take_read_packet(s); |
269 | assert(p); | |
270 | ||
271 | scope = manager_find_scope(s->manager, p); | |
b30bf55d | 272 | if (!scope) |
f1b1a5c4 | 273 | log_debug("Got LLMNR TCP packet on unknown scope. Ignoring."); |
aa337a5e LP |
274 | else if (dns_packet_validate_query(p) > 0) { |
275 | log_debug("Got LLMNR TCP query packet for id %u", DNS_PACKET_ID(p)); | |
5f402ae8 | 276 | |
aa337a5e | 277 | dns_scope_process_query(scope, s, p); |
5f402ae8 | 278 | } else |
b30bf55d | 279 | log_debug("Invalid LLMNR TCP packet, ignoring."); |
5f402ae8 | 280 | |
b30bf55d | 281 | dns_stream_unref(s); |
5f402ae8 DM |
282 | return 0; |
283 | } | |
284 | ||
285 | static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
286 | DnsStream *stream; | |
287 | Manager *m = userdata; | |
288 | int cfd, r; | |
289 | ||
290 | cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); | |
291 | if (cfd < 0) { | |
3742095b | 292 | if (IN_SET(errno, EAGAIN, EINTR)) |
5f402ae8 DM |
293 | return 0; |
294 | ||
295 | return -errno; | |
296 | } | |
297 | ||
652ba568 | 298 | r = dns_stream_new(m, &stream, DNS_STREAM_LLMNR_RECV, DNS_PROTOCOL_LLMNR, cfd, NULL); |
5f402ae8 DM |
299 | if (r < 0) { |
300 | safe_close(cfd); | |
301 | return r; | |
302 | } | |
303 | ||
304 | stream->on_packet = on_llmnr_stream_packet; | |
31f2a5e2 LP |
305 | /* We don't configure a "complete" handler here, we rely on the default handler than simply drops the |
306 | * reference to the stream, thus freeing it */ | |
5f402ae8 DM |
307 | return 0; |
308 | } | |
309 | ||
310 | int manager_llmnr_ipv4_tcp_fd(Manager *m) { | |
311 | union sockaddr_union sa = { | |
312 | .in.sin_family = AF_INET, | |
22a37591 | 313 | .in.sin_port = htobe16(LLMNR_PORT), |
5f402ae8 | 314 | }; |
3f548fff | 315 | _cleanup_close_ int s = -1; |
5f402ae8 DM |
316 | int r; |
317 | ||
318 | assert(m); | |
319 | ||
320 | if (m->llmnr_ipv4_tcp_fd >= 0) | |
321 | return m->llmnr_ipv4_tcp_fd; | |
322 | ||
3f548fff YW |
323 | s = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
324 | if (s < 0) | |
007ef0a2 | 325 | return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to create socket: %m"); |
5f402ae8 DM |
326 | |
327 | /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */ | |
3f548fff YW |
328 | r = setsockopt_int(s, IPPROTO_IP, IP_TTL, true); |
329 | if (r < 0) | |
330 | return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_TTL: %m"); | |
5f402ae8 | 331 | |
3f548fff YW |
332 | r = setsockopt_int(s, IPPROTO_IP, IP_PKTINFO, true); |
333 | if (r < 0) | |
334 | return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_PKTINFO: %m"); | |
5f402ae8 | 335 | |
3f548fff YW |
336 | r = setsockopt_int(s, IPPROTO_IP, IP_RECVTTL, true); |
337 | if (r < 0) | |
338 | return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_RECVTTL: %m"); | |
5f402ae8 DM |
339 | |
340 | /* Disable Don't-Fragment bit in the IP header */ | |
3f548fff YW |
341 | r = setsockopt_int(s, IPPROTO_IP, IP_MTU_DISCOVER, IP_PMTUDISC_DONT); |
342 | if (r < 0) | |
343 | return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set IP_MTU_DISCOVER: %m"); | |
5f402ae8 | 344 | |
007ef0a2 | 345 | /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ |
3f548fff | 346 | r = bind(s, &sa.sa, sizeof(sa.in)); |
5f402ae8 | 347 | if (r < 0) { |
3f548fff YW |
348 | if (errno != EADDRINUSE) |
349 | return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m"); | |
007ef0a2 YW |
350 | |
351 | log_warning("LLMNR-IPv4(TCP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); | |
352 | ||
353 | /* try again with SO_REUSEADDR */ | |
3f548fff YW |
354 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
355 | if (r < 0) | |
356 | return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m"); | |
357 | ||
358 | r = bind(s, &sa.sa, sizeof(sa.in)); | |
359 | if (r < 0) | |
360 | return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to bind socket: %m"); | |
007ef0a2 YW |
361 | } else { |
362 | /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ | |
3f548fff YW |
363 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
364 | if (r < 0) | |
365 | return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to set SO_REUSEADDR: %m"); | |
5f402ae8 DM |
366 | } |
367 | ||
3f548fff YW |
368 | r = listen(s, SOMAXCONN); |
369 | if (r < 0) | |
370 | return log_error_errno(errno, "LLMNR-IPv4(TCP): Failed to listen the stream: %m"); | |
5f402ae8 | 371 | |
3f548fff | 372 | r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, s, EPOLLIN, on_llmnr_stream, m); |
5f402ae8 | 373 | if (r < 0) |
3f548fff | 374 | return log_error_errno(r, "LLMNR-IPv4(TCP): Failed to create event source: %m"); |
5f402ae8 | 375 | |
aa4a9deb LP |
376 | (void) sd_event_source_set_description(m->llmnr_ipv4_tcp_event_source, "llmnr-ipv4-tcp"); |
377 | ||
3f548fff | 378 | return m->llmnr_ipv4_tcp_fd = TAKE_FD(s); |
5f402ae8 DM |
379 | } |
380 | ||
381 | int manager_llmnr_ipv6_tcp_fd(Manager *m) { | |
382 | union sockaddr_union sa = { | |
383 | .in6.sin6_family = AF_INET6, | |
22a37591 | 384 | .in6.sin6_port = htobe16(LLMNR_PORT), |
5f402ae8 | 385 | }; |
3f548fff | 386 | _cleanup_close_ int s = -1; |
5f402ae8 DM |
387 | int r; |
388 | ||
389 | assert(m); | |
390 | ||
391 | if (m->llmnr_ipv6_tcp_fd >= 0) | |
392 | return m->llmnr_ipv6_tcp_fd; | |
393 | ||
3f548fff YW |
394 | s = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); |
395 | if (s < 0) | |
007ef0a2 | 396 | return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to create socket: %m"); |
5f402ae8 DM |
397 | |
398 | /* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */ | |
3f548fff YW |
399 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_UNICAST_HOPS, true); |
400 | if (r < 0) | |
401 | return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_UNICAST_HOPS: %m"); | |
5f402ae8 | 402 | |
3f548fff YW |
403 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_V6ONLY, true); |
404 | if (r < 0) | |
405 | return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_V6ONLY: %m"); | |
5f402ae8 | 406 | |
3f548fff YW |
407 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, true); |
408 | if (r < 0) | |
409 | return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVPKTINFO: %m"); | |
5f402ae8 | 410 | |
3f548fff YW |
411 | r = setsockopt_int(s, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, true); |
412 | if (r < 0) | |
413 | return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set IPV6_RECVHOPLIMIT: %m"); | |
5f402ae8 | 414 | |
007ef0a2 | 415 | /* first try to bind without SO_REUSEADDR to detect another LLMNR responder */ |
3f548fff | 416 | r = bind(s, &sa.sa, sizeof(sa.in6)); |
5f402ae8 | 417 | if (r < 0) { |
3f548fff YW |
418 | if (errno != EADDRINUSE) |
419 | return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m"); | |
007ef0a2 YW |
420 | |
421 | log_warning("LLMNR-IPv6(TCP): There appears to be another LLMNR responder running, or previously systemd-resolved crashed with some outstanding transfers."); | |
422 | ||
423 | /* try again with SO_REUSEADDR */ | |
3f548fff YW |
424 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
425 | if (r < 0) | |
426 | return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m"); | |
427 | ||
428 | r = bind(s, &sa.sa, sizeof(sa.in6)); | |
429 | if (r < 0) | |
430 | return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to bind socket: %m"); | |
007ef0a2 YW |
431 | } else { |
432 | /* enable SO_REUSEADDR for the case that the user really wants multiple LLMNR responders */ | |
3f548fff YW |
433 | r = setsockopt_int(s, SOL_SOCKET, SO_REUSEADDR, true); |
434 | if (r < 0) | |
435 | return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to set SO_REUSEADDR: %m"); | |
5f402ae8 DM |
436 | } |
437 | ||
3f548fff YW |
438 | r = listen(s, SOMAXCONN); |
439 | if (r < 0) | |
440 | return log_error_errno(errno, "LLMNR-IPv6(TCP): Failed to listen the stream: %m"); | |
5f402ae8 | 441 | |
3f548fff | 442 | r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, s, EPOLLIN, on_llmnr_stream, m); |
ee8d9305 | 443 | if (r < 0) |
3f548fff | 444 | return log_error_errno(r, "LLMNR-IPv6(TCP): Failed to create event source: %m"); |
5f402ae8 | 445 | |
aa4a9deb LP |
446 | (void) sd_event_source_set_description(m->llmnr_ipv6_tcp_event_source, "llmnr-ipv6-tcp"); |
447 | ||
3f548fff | 448 | return m->llmnr_ipv6_tcp_fd = TAKE_FD(s); |
5f402ae8 | 449 | } |