2 This file is part of GNUnet.
3 Copyright (C) 2009-2015 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
22 * @file util/resolver_api.c
23 * @brief resolver for writing a tool
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_protocols.h"
29 #include "gnunet_resolver_service.h"
32 #define LOG(kind,...) GNUNET_log_from (kind, "resolver-api", __VA_ARGS__)
34 #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "resolver-api", syscall)
37 * Maximum supported length for a hostname
39 #define MAX_HOSTNAME 1024
43 * Possible hostnames for "loopback".
45 static const char *loopback[] = {
55 static const struct GNUNET_CONFIGURATION_Handle *resolver_cfg;
58 * Our connection to the resolver service, created on-demand, but then
59 * persists until error or shutdown.
61 static struct GNUNET_CLIENT_Connection *client;
64 * Head of DLL of requests.
66 static struct GNUNET_RESOLVER_RequestHandle *req_head;
69 * Tail of DLL of requests.
71 static struct GNUNET_RESOLVER_RequestHandle *req_tail;
74 * How long should we wait to reconnect?
76 static struct GNUNET_TIME_Relative backoff;
79 * Task for reconnecting.
81 static struct GNUNET_SCHEDULER_Task *r_task;
84 * Task ID of shutdown task; only present while we have a
85 * connection to the resolver service.
87 static struct GNUNET_SCHEDULER_Task *s_task;
91 * Handle to a request given to the resolver. Can be used to cancel
92 * the request prior to the timeout or successful execution. Also
93 * used to track our internal state for the request.
95 struct GNUNET_RESOLVER_RequestHandle
99 * Next entry in DLL of requests.
101 struct GNUNET_RESOLVER_RequestHandle *next;
104 * Previous entry in DLL of requests.
106 struct GNUNET_RESOLVER_RequestHandle *prev;
109 * Callback if this is an name resolution request,
112 GNUNET_RESOLVER_AddressCallback addr_callback;
115 * Callback if this is a reverse lookup request,
118 GNUNET_RESOLVER_HostnameCallback name_callback;
121 * Closure for the respective "callback".
126 * When should this request time out?
128 struct GNUNET_TIME_Absolute timeout;
131 * Task handle for making reply callbacks in numeric lookups
132 * asynchronous, and for timeout handling.
134 struct GNUNET_SCHEDULER_Task * task;
137 * Desired address family.
142 * Has this request been transmitted to the service?
143 * #GNUNET_YES if transmitted
144 * #GNUNET_YES if not transmitted
145 * #GNUNET_SYSERR when request was canceled
150 * Did we add this request to the queue?
155 * Desired direction (IP to name or name to IP)
160 * #GNUNET_YES if a response was received
162 int received_response;
165 * Length of the data that follows this struct.
172 * Check that the resolver service runs on localhost
180 struct sockaddr_in v4;
181 struct sockaddr_in6 v6;
183 memset (&v4, 0, sizeof (v4));
184 v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
185 v4.sin_family = AF_INET;
186 #if HAVE_SOCKADDR_IN_SIN_LEN
187 v4.sin_len = sizeof (v4);
189 memset (&v6, 0, sizeof (v6));
190 v6.sin6_family = AF_INET6;
191 #if HAVE_SOCKADDR_IN_SIN_LEN
192 v6.sin6_len = sizeof (v6);
195 GNUNET_CONFIGURATION_get_value_string (resolver_cfg,
200 LOG (GNUNET_ERROR_TYPE_ERROR,
201 _("Must specify `%s' for `%s' in configuration!\n"),
206 if ((1 != inet_pton (AF_INET, hostname, &v4)) ||
207 (1 != inet_pton (AF_INET6, hostname, &v6)))
209 GNUNET_free (hostname);
213 while (NULL != loopback[i])
214 if (0 == strcasecmp (loopback[i++], hostname))
216 GNUNET_free (hostname);
219 LOG (GNUNET_ERROR_TYPE_ERROR,
220 _("Must specify `%s' or numeric IP address for `%s' of `%s' in configuration!\n"),
224 GNUNET_free (hostname);
230 * Create the connection to the resolver service.
232 * @param cfg configuration to use
235 GNUNET_RESOLVER_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
237 GNUNET_assert (NULL != cfg);
238 backoff = GNUNET_TIME_UNIT_MILLISECONDS;
245 * Destroy the connection to the resolver service.
248 GNUNET_RESOLVER_disconnect ()
250 GNUNET_assert (NULL == req_head);
251 GNUNET_assert (NULL == req_tail);
254 LOG (GNUNET_ERROR_TYPE_DEBUG,
255 "Disconnecting from DNS service\n");
256 GNUNET_CLIENT_disconnect (client);
261 GNUNET_SCHEDULER_cancel (r_task);
266 GNUNET_SCHEDULER_cancel (s_task);
273 * Convert IP address to string without DNS resolution.
275 * @param af address family
276 * @param ip the address
277 * @param ip_len number of bytes in @a ip
278 * @return address as a string, NULL on error
282 const void *ip, socklen_t ip_len)
284 char buf[INET6_ADDRSTRLEN];
289 if (ip_len != sizeof (struct in_addr))
292 inet_ntop (AF_INET, ip, buf, sizeof (buf)))
294 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
300 if (ip_len != sizeof (struct in6_addr))
303 inet_ntop (AF_INET6, ip, buf, sizeof (buf)))
305 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
314 return GNUNET_strdup (buf);
319 * Adjust exponential back-off and reconnect to the service.
326 * Process pending requests to the resolver.
329 process_requests (void);
333 * Process response with a hostname for a DNS lookup.
335 * @param cls our `struct GNUNET_RESOLVER_RequestHandle *` context
336 * @param msg message with the hostname, NULL on error
339 handle_response (void *cls,
340 const struct GNUNET_MessageHeader *msg)
342 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
346 LOG (GNUNET_ERROR_TYPE_DEBUG,
347 "Receiving response from DNS service\n");
350 char buf[INET6_ADDRSTRLEN];
352 if (NULL != rh->name_callback)
353 LOG (GNUNET_ERROR_TYPE_INFO,
354 _("Timeout trying to resolve IP address `%s'.\n"),
356 (const void *) &rh[1],
360 LOG (GNUNET_ERROR_TYPE_INFO,
361 _("Timeout trying to resolve hostname `%s'.\n"),
362 (const char *) &rh[1]);
363 /* check if request was canceled */
364 if (GNUNET_SYSERR != rh->was_transmitted)
366 if (NULL != rh->name_callback)
368 /* no reverse lookup was successful, return IP as string */
369 if (GNUNET_NO == rh->received_response)
371 nret = no_resolve (rh->af,
374 rh->name_callback (rh->cls, nret);
377 /* finally, make termination call */
378 rh->name_callback (rh->cls,
381 if (NULL != rh->addr_callback)
382 rh->addr_callback (rh->cls,
386 rh->was_transmitted = GNUNET_NO;
387 GNUNET_RESOLVER_request_cancel (rh);
388 GNUNET_CLIENT_disconnect (client);
393 if (GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE != ntohs (msg->type))
396 GNUNET_CLIENT_disconnect (client);
401 size = ntohs (msg->size);
402 if (size == sizeof (struct GNUNET_MessageHeader))
404 LOG (GNUNET_ERROR_TYPE_DEBUG,
405 "Received empty response from DNS service\n");
406 /* message contains not data, just header; end of replies */
407 /* check if request was canceled */
408 if (GNUNET_SYSERR != rh->was_transmitted)
410 /* no reverse lookup was successful, return IP as string */
411 if (NULL != rh->name_callback)
413 if (GNUNET_NO == rh->received_response)
415 nret = no_resolve (rh->af,
418 rh->name_callback (rh->cls, nret);
421 /* finally, make termination call */
422 rh->name_callback (rh->cls,
425 if (NULL != rh->addr_callback)
426 rh->addr_callback (rh->cls,
430 rh->was_transmitted = GNUNET_NO;
431 GNUNET_RESOLVER_request_cancel (rh);
435 /* return reverse lookup results to caller */
436 if (NULL != rh->name_callback)
438 const char *hostname;
440 hostname = (const char *) &msg[1];
441 if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
444 if (GNUNET_SYSERR != rh->was_transmitted)
445 rh->name_callback (rh->cls,
447 rh->was_transmitted = GNUNET_NO;
448 GNUNET_RESOLVER_request_cancel (rh);
449 GNUNET_CLIENT_disconnect (client);
454 LOG (GNUNET_ERROR_TYPE_DEBUG,
455 "Resolver returns `%s' for IP `%s'.\n",
457 GNUNET_a2s ((const void *) &rh[1],
459 if (rh->was_transmitted != GNUNET_SYSERR)
460 rh->name_callback (rh->cls,
462 rh->received_response = GNUNET_YES;
464 /* return lookup results to caller */
465 if (NULL != rh->addr_callback)
467 struct sockaddr_in v4;
468 struct sockaddr_in6 v6;
469 const struct sockaddr *sa;
475 ip_len = size - sizeof (struct GNUNET_MessageHeader);
476 if (ip_len == sizeof (struct in_addr))
478 memset (&v4, 0, sizeof (v4));
479 v4.sin_family = AF_INET;
480 v4.sin_addr = *(struct in_addr*) ip;
481 #if HAVE_SOCKADDR_IN_SIN_LEN
482 v4.sin_len = sizeof (v4);
485 sa = (const struct sockaddr *) &v4;
487 else if (ip_len == sizeof (struct in6_addr))
489 memset (&v6, 0, sizeof (v6));
490 v6.sin6_family = AF_INET6;
491 v6.sin6_addr = *(struct in6_addr*) ip;
492 #if HAVE_SOCKADDR_IN_SIN_LEN
493 v6.sin6_len = sizeof (v6);
496 sa = (const struct sockaddr *) &v6;
501 if (GNUNET_SYSERR != rh->was_transmitted)
502 rh->addr_callback (rh->cls,
505 rh->was_transmitted = GNUNET_NO;
506 GNUNET_RESOLVER_request_cancel (rh);
507 GNUNET_CLIENT_disconnect (client);
512 LOG (GNUNET_ERROR_TYPE_DEBUG,
513 "Received IP from DNS service\n");
514 if (GNUNET_SYSERR != rh->was_transmitted)
515 rh->addr_callback (rh->cls,
519 GNUNET_CLIENT_receive (client,
522 GNUNET_TIME_absolute_get_remaining (rh->timeout));
527 * We've been asked to lookup the address for a hostname and were
528 * given a valid numeric string. Perform the callbacks for the
531 * @param cls `struct GNUNET_RESOLVER_RequestHandle` for the request
532 * @param tc unused scheduler context
535 numeric_resolution (void *cls,
536 const struct GNUNET_SCHEDULER_TaskContext *tc)
538 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
539 struct sockaddr_in v4;
540 struct sockaddr_in6 v6;
541 const char *hostname;
544 memset (&v4, 0, sizeof (v4));
545 v4.sin_family = AF_INET;
546 #if HAVE_SOCKADDR_IN_SIN_LEN
547 v4.sin_len = sizeof (v4);
549 memset (&v6, 0, sizeof (v6));
550 v6.sin6_family = AF_INET6;
551 #if HAVE_SOCKADDR_IN_SIN_LEN
552 v6.sin6_len = sizeof (v6);
554 hostname = (const char *) &rh[1];
555 if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET)) &&
556 (1 == inet_pton (AF_INET, hostname, &v4.sin_addr)))
558 rh->addr_callback (rh->cls,
559 (const struct sockaddr *) &v4,
561 if ((rh->af == AF_UNSPEC) &&
562 (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
564 /* this can happen on some systems IF "hostname" is "localhost" */
565 rh->addr_callback (rh->cls,
566 (const struct sockaddr *) &v6,
569 rh->addr_callback (rh->cls,
575 if ( ( (rh->af == AF_UNSPEC) ||
576 (rh->af == AF_INET6) ) &&
577 (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr) ) )
579 rh->addr_callback (rh->cls,
580 (const struct sockaddr *) &v6,
582 rh->addr_callback (rh->cls,
588 /* why are we here? this task should not have been scheduled! */
595 * We've been asked to lookup the address for a hostname and were
596 * given a variant of "loopback". Perform the callbacks for the
597 * respective loopback numeric addresses.
599 * @param cls `struct GNUNET_RESOLVER_RequestHandle` for the request
600 * @param tc unused scheduler context
603 loopback_resolution (void *cls,
604 const struct GNUNET_SCHEDULER_TaskContext *tc)
606 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
607 struct sockaddr_in v4;
608 struct sockaddr_in6 v6;
611 memset (&v4, 0, sizeof (v4));
612 v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
613 v4.sin_family = AF_INET;
614 #if HAVE_SOCKADDR_IN_SIN_LEN
615 v4.sin_len = sizeof (v4);
617 memset (&v6, 0, sizeof (v6));
618 v6.sin6_family = AF_INET6;
619 #if HAVE_SOCKADDR_IN_SIN_LEN
620 v6.sin6_len = sizeof (v6);
622 v6.sin6_addr = in6addr_loopback;
626 rh->addr_callback (rh->cls,
627 (const struct sockaddr *) &v4,
631 rh->addr_callback (rh->cls,
632 (const struct sockaddr *) &v6,
636 rh->addr_callback (rh->cls,
637 (const struct sockaddr *) &v6,
639 rh->addr_callback (rh->cls,
640 (const struct sockaddr *) &v4,
647 rh->addr_callback (rh->cls,
655 * Task executed on system shutdown.
658 shutdown_task (void *cls,
659 const struct GNUNET_SCHEDULER_TaskContext *tc)
662 GNUNET_RESOLVER_disconnect ();
663 backoff = GNUNET_TIME_UNIT_MILLISECONDS;
668 * Process pending requests to the resolver.
673 struct GNUNET_RESOLVER_GetMessage *msg;
674 char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1] GNUNET_ALIGN;
675 struct GNUNET_RESOLVER_RequestHandle *rh;
685 /* nothing to do, release socket really soon if there is nothing
686 * else happening... */
688 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS,
693 if (GNUNET_NO != rh->was_transmitted)
694 return; /* waiting for reply */
695 msg = (struct GNUNET_RESOLVER_GetMessage *) buf;
697 htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + rh->data_len);
698 msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
699 msg->direction = htonl (rh->direction);
700 msg->af = htonl (rh->af);
704 LOG (GNUNET_ERROR_TYPE_DEBUG,
705 "Transmitting DNS resolution request to DNS service\n");
707 GNUNET_CLIENT_transmit_and_get_response (client,
709 GNUNET_TIME_absolute_get_remaining (rh->timeout),
714 GNUNET_CLIENT_disconnect (client);
720 rh->was_transmitted = GNUNET_YES;
725 * Now try to reconnect to the resolver service.
728 * @param tc scheduler context
731 reconnect_task (void *cls,
732 const struct GNUNET_SCHEDULER_TaskContext *tc)
735 if (NULL == req_head)
736 return; /* no work pending */
737 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
739 LOG (GNUNET_ERROR_TYPE_DEBUG,
740 "Trying to connect to DNS service\n");
741 client = GNUNET_CLIENT_connect ("resolver",
745 LOG (GNUNET_ERROR_TYPE_DEBUG,
746 "Failed to connect, will try again later\n");
755 * Adjust exponential back-off and reconnect to the service.
760 struct GNUNET_RESOLVER_RequestHandle *rh;
764 GNUNET_assert (NULL == client);
765 if (NULL != (rh = req_head))
767 switch (rh->was_transmitted)
770 /* nothing more to do */
773 /* disconnected, transmit again! */
774 rh->was_transmitted = GNUNET_NO;
777 /* request was cancelled, remove entirely */
778 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
786 LOG (GNUNET_ERROR_TYPE_DEBUG,
787 "Will try to connect to DNS service in %s\n",
788 GNUNET_STRINGS_relative_time_to_string (backoff,
790 GNUNET_assert (NULL != resolver_cfg);
791 r_task = GNUNET_SCHEDULER_add_delayed (backoff,
794 backoff = GNUNET_TIME_STD_BACKOFF (backoff);
799 * A DNS resolution timed out. Notify the application.
801 * @param cls the `struct GNUNET_RESOLVER_RequestHandle *`
802 * @param tc scheduler context
805 handle_lookup_timeout (void *cls,
806 const struct GNUNET_SCHEDULER_TaskContext *tc)
808 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
811 rh->addr_callback (rh->cls,
814 GNUNET_RESOLVER_request_cancel (rh);
819 * Convert a string to one or more IP addresses.
821 * @param hostname the hostname to resolve
822 * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
823 * @param callback function to call with addresses
824 * @param callback_cls closure for @a callback
825 * @param timeout how long to try resolving
826 * @return handle that can be used to cancel the request, NULL on error
828 struct GNUNET_RESOLVER_RequestHandle *
829 GNUNET_RESOLVER_ip_get (const char *hostname,
831 struct GNUNET_TIME_Relative timeout,
832 GNUNET_RESOLVER_AddressCallback callback,
835 struct GNUNET_RESOLVER_RequestHandle *rh;
841 slen = strlen (hostname) + 1;
842 if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >=
843 GNUNET_SERVER_MAX_MESSAGE_SIZE)
848 rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + slen);
850 rh->addr_callback = callback;
851 rh->cls = callback_cls;
856 rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
857 rh->direction = GNUNET_NO;
858 /* first, check if this is a numeric address */
859 if (((1 == inet_pton (AF_INET, hostname, &v4)) &&
860 ((af == AF_INET) || (af == AF_UNSPEC))) ||
861 ((1 == inet_pton (AF_INET6, hostname, &v6)) &&
862 ((af == AF_INET6) || (af == AF_UNSPEC))))
864 rh->task = GNUNET_SCHEDULER_add_now (&numeric_resolution,
868 /* then, check if this is a loopback address */
870 while (NULL != loopback[i])
871 if (0 == strcasecmp (loopback[i++],
874 rh->task = GNUNET_SCHEDULER_add_now (&loopback_resolution,
878 rh->task = GNUNET_SCHEDULER_add_delayed (timeout,
879 &handle_lookup_timeout,
881 GNUNET_CONTAINER_DLL_insert_tail (req_head,
884 rh->was_queued = GNUNET_YES;
887 GNUNET_SCHEDULER_cancel (s_task);
896 * We've been asked to convert an address to a string without
897 * a reverse lookup, either because the client asked for it
898 * or because the DNS lookup hit a timeout. Do the numeric
899 * conversion and invoke the callback.
901 * @param cls `struct GNUNET_RESOLVER_RequestHandle` for the request
902 * @param tc unused scheduler context
905 numeric_reverse (void *cls,
906 const struct GNUNET_SCHEDULER_TaskContext *tc)
908 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
912 result = no_resolve (rh->af,
915 LOG (GNUNET_ERROR_TYPE_DEBUG,
916 "Resolver returns `%s'.\n",
920 rh->name_callback (rh->cls,
922 GNUNET_free (result);
924 rh->name_callback (rh->cls,
931 * Get an IP address as a string.
933 * @param sa host address
934 * @param salen length of host address in @a sa
935 * @param do_resolve use #GNUNET_NO to return numeric hostname
936 * @param timeout how long to try resolving
937 * @param callback function to call with hostnames
938 * last callback is NULL when finished
939 * @param cls closure for @a callback
940 * @return handle that can be used to cancel the request
942 struct GNUNET_RESOLVER_RequestHandle *
943 GNUNET_RESOLVER_hostname_get (const struct sockaddr *sa,
946 struct GNUNET_TIME_Relative timeout,
947 GNUNET_RESOLVER_HostnameCallback callback,
950 struct GNUNET_RESOLVER_RequestHandle *rh;
955 switch (sa->sa_family)
958 GNUNET_assert (salen == sizeof (struct sockaddr_in));
959 ip_len = sizeof (struct in_addr);
960 ip = &((const struct sockaddr_in*)sa)->sin_addr;
963 GNUNET_assert (salen == sizeof (struct sockaddr_in6));
964 ip_len = sizeof (struct in6_addr);
965 ip = &((const struct sockaddr_in6*)sa)->sin6_addr;
971 rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + salen);
972 rh->name_callback = callback;
974 rh->af = sa->sa_family;
975 rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
976 memcpy (&rh[1], ip, ip_len);
977 rh->data_len = ip_len;
978 rh->direction = GNUNET_YES;
979 rh->received_response = GNUNET_NO;
980 if (GNUNET_NO == do_resolve)
982 rh->task = GNUNET_SCHEDULER_add_now (&numeric_reverse, rh);
985 GNUNET_CONTAINER_DLL_insert_tail (req_head,
988 rh->was_queued = GNUNET_YES;
991 GNUNET_SCHEDULER_cancel (s_task);
1000 * Get local fully qualified af name
1005 GNUNET_RESOLVER_local_fqdn_get ()
1007 char hostname[GNUNET_OS_get_hostname_max_length () + 1];
1009 if (0 != gethostname (hostname, sizeof (hostname) - 1))
1011 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
1015 LOG (GNUNET_ERROR_TYPE_DEBUG,
1016 "Resolving our FQDN `%s'\n",
1018 #if HAVE_GETADDRINFO
1020 struct addrinfo *ai;
1024 if (0 != (ret = getaddrinfo (hostname, NULL, NULL, &ai)))
1026 LOG (GNUNET_ERROR_TYPE_ERROR,
1027 _("Could not resolve our FQDN: %s\n"),
1028 gai_strerror (ret));
1031 if (NULL != ai->ai_canonname)
1032 rval = GNUNET_strdup (ai->ai_canonname);
1034 rval = GNUNET_strdup (hostname);
1038 #elif HAVE_GETHOSTBYNAME2
1040 struct hostent *host;
1042 host = gethostbyname2 (hostname, AF_INET);
1044 host = gethostbyname2 (hostname, AF_INET6);
1047 LOG (GNUNET_ERROR_TYPE_ERROR,
1048 _("Could not resolve our FQDN: %s\n"),
1049 hstrerror (h_errno));
1052 return GNUNET_strdup (host->h_name);
1054 #elif HAVE_GETHOSTBYNAME
1056 struct hostent *host;
1058 host = gethostbyname (hostname);
1061 LOG (GNUNET_ERROR_TYPE_ERROR,
1062 _("Could not resolve our FQDN: %s\n"),
1063 hstrerror (h_errno));
1066 return GNUNET_strdup (host->h_name);
1069 /* fallback: just hope name is already FQDN */
1070 return GNUNET_strdup (hostname);
1076 * Looking our own hostname.
1078 * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
1079 * @param timeout how long to try resolving
1080 * @param callback function to call with addresses
1081 * @param cls closure for @a callback
1082 * @return handle that can be used to cancel the request, NULL on error
1084 struct GNUNET_RESOLVER_RequestHandle *
1085 GNUNET_RESOLVER_hostname_resolve (int af,
1086 struct GNUNET_TIME_Relative timeout,
1087 GNUNET_RESOLVER_AddressCallback callback,
1090 char hostname[GNUNET_OS_get_hostname_max_length () + 1];
1092 if (0 != gethostname (hostname, sizeof (hostname) - 1))
1094 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
1098 LOG (GNUNET_ERROR_TYPE_DEBUG,
1099 "Resolving our hostname `%s'\n",
1101 return GNUNET_RESOLVER_ip_get (hostname,
1110 * Cancel a request that is still pending with the resolver.
1111 * Note that a client MUST NOT cancel a request that has
1112 * been completed (i.e, the callback has been called to
1113 * signal timeout or the final result).
1115 * @param rh handle of request to cancel
1118 GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *rh)
1120 if (NULL != rh->task)
1122 GNUNET_SCHEDULER_cancel (rh->task);
1125 if (GNUNET_NO == rh->was_transmitted)
1127 if (GNUNET_YES == rh->was_queued)
1128 GNUNET_CONTAINER_DLL_remove (req_head,
1134 GNUNET_assert (GNUNET_YES == rh->was_transmitted);
1135 rh->was_transmitted = GNUNET_SYSERR; /* mark as cancelled */
1139 /* end of resolver_api.c */