2 This file is part of GNUnet.
3 (C) 2009, 2011 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 2, 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., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file util/resolver_api.c
23 * @brief resolver for writing a tool
24 * @author Christian Grothoff
27 #include "gnunet_getopt_lib.h"
28 #include "gnunet_os_lib.h"
29 #include "gnunet_client_lib.h"
30 #include "gnunet_container_lib.h"
31 #include "gnunet_protocols.h"
32 #include "gnunet_resolver_service.h"
33 #include "gnunet_server_lib.h"
36 #define LOG(kind,...) GNUNET_log_from (kind, "resolver-api", __VA_ARGS__)
38 #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "resolver-api", syscall)
41 * Maximum supported length for a hostname
43 #define MAX_HOSTNAME 1024
47 * Possible hostnames for "loopback".
49 static const char *loopback[] = {
59 static const struct GNUNET_CONFIGURATION_Handle *resolver_cfg;
62 * Our connection to the resolver service, created on-demand, but then
63 * persists until error or shutdown.
65 static struct GNUNET_CLIENT_Connection *client;
68 * Head of DLL of requests.
70 static struct GNUNET_RESOLVER_RequestHandle *req_head;
73 * Tail of DLL of requests.
75 static struct GNUNET_RESOLVER_RequestHandle *req_tail;
78 * How long should we wait to reconnect?
80 static struct GNUNET_TIME_Relative backoff;
83 * Task for reconnecting.
85 static GNUNET_SCHEDULER_TaskIdentifier r_task;
88 * Task ID of shutdown task; only present while we have a
89 * connection to the resolver service.
91 static GNUNET_SCHEDULER_TaskIdentifier s_task;
95 * Handle to a request given to the resolver. Can be used to cancel
96 * the request prior to the timeout or successful execution. Also
97 * used to track our internal state for the request.
99 struct GNUNET_RESOLVER_RequestHandle
103 * Next entry in DLL of requests.
105 struct GNUNET_RESOLVER_RequestHandle *next;
108 * Previous entry in DLL of requests.
110 struct GNUNET_RESOLVER_RequestHandle *prev;
113 * Callback if this is an name resolution request,
116 GNUNET_RESOLVER_AddressCallback addr_callback;
119 * Callback if this is a reverse lookup request,
122 GNUNET_RESOLVER_HostnameCallback name_callback;
125 * Closure for the respective "callback".
130 * When should this request time out?
132 struct GNUNET_TIME_Absolute timeout;
135 * Task handle for numeric lookups.
137 GNUNET_SCHEDULER_TaskIdentifier task;
140 * Desired address family.
145 * Has this request been transmitted to the service?
146 * GNUNET_YES if transmitted
147 * GNUNET_YES if not transmitted
148 * GNUNET_SYSERR when request was canceled
153 * Did we add this request to the queue?
158 * Desired direction (IP to name or name to IP)
163 * GNUNET_YES if a response was received
165 int received_response;
168 * Length of the data that follows this struct.
175 * Check that the resolver service runs on localhost
183 struct sockaddr_in v4;
184 struct sockaddr_in6 v6;
186 memset (&v4, 0, sizeof (v4));
187 v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
188 v4.sin_family = AF_INET;
189 #if HAVE_SOCKADDR_IN_SIN_LEN
190 v4.sin_len = sizeof (v4);
192 memset (&v6, 0, sizeof (v6));
193 v6.sin6_family = AF_INET6;
194 #if HAVE_SOCKADDR_IN_SIN_LEN
195 v6.sin6_len = sizeof (v6);
198 GNUNET_CONFIGURATION_get_value_string (resolver_cfg, "resolver",
199 "HOSTNAME", &hostname))
201 LOG (GNUNET_ERROR_TYPE_ERROR,
202 _("Must specify `%s' for `%s' in configuration!\n"), "HOSTNAME",
206 if ((1 != inet_pton (AF_INET, hostname, &v4)) ||
207 (1 != inet_pton (AF_INET6, hostname, &v6)))
209 GNUNET_free (hostname);
213 while (loopback[i] != NULL)
214 if (0 == strcasecmp (loopback[i++], hostname))
216 GNUNET_free (hostname);
219 LOG (GNUNET_ERROR_TYPE_ERROR,
221 ("Must specify `%s' or numeric IP address for `%s' of `%s' in configuration!\n"),
222 "localhost", "HOSTNAME", "resolver");
223 GNUNET_free (hostname);
229 * Create the connection to the resolver service.
231 * @param cfg configuration to use
234 GNUNET_RESOLVER_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
236 GNUNET_assert (NULL != cfg);
237 backoff = GNUNET_TIME_UNIT_MILLISECONDS;
244 * Destroy the connection to the resolver service.
247 GNUNET_RESOLVER_disconnect ()
249 GNUNET_assert (NULL == req_head);
250 GNUNET_assert (NULL == req_tail);
254 LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting from DNS service\n");
256 GNUNET_CLIENT_disconnect (client);
259 if (r_task != GNUNET_SCHEDULER_NO_TASK)
261 GNUNET_SCHEDULER_cancel (r_task);
262 r_task = GNUNET_SCHEDULER_NO_TASK;
264 if (s_task != GNUNET_SCHEDULER_NO_TASK)
266 GNUNET_SCHEDULER_cancel (s_task);
267 s_task = GNUNET_SCHEDULER_NO_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 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, "inet_ntop");
299 if (ip_len != sizeof (struct in6_addr))
302 inet_ntop (AF_INET6, ip, buf, sizeof (buf)))
304 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "inet_ntop");
312 return GNUNET_strdup (buf);
317 * Adjust exponential back-off and reconnect to the service.
324 * Process pending requests to the resolver.
331 * Process response with a hostname for a DNS lookup.
333 * @param cls our "struct GNUNET_RESOLVER_RequestHandle" context
334 * @param msg message with the hostname, NULL on error
337 handle_response (void *cls, const struct GNUNET_MessageHeader *msg)
339 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
343 LOG (GNUNET_ERROR_TYPE_DEBUG, "Receiving response from DNS service\n");
347 char buf[INET6_ADDRSTRLEN];
349 if (NULL != rh->name_callback)
350 LOG (GNUNET_ERROR_TYPE_INFO,
351 _("Timeout trying to resolve IP address `%s'.\n"),
352 inet_ntop (rh->af, (const void *) &rh[1], buf, sizeof(buf)));
354 LOG (GNUNET_ERROR_TYPE_INFO,
355 _("Timeout trying to resolve hostname `%s'.\n"),
356 (const char *) &rh[1]);
357 /* check if request was canceled */
358 if (rh->was_transmitted != GNUNET_SYSERR)
360 if (NULL != rh->name_callback)
362 /* no reverse lookup was successful, return ip as string */
363 if (rh->received_response == GNUNET_NO)
364 rh->name_callback (rh->cls,
368 /* at least one reverse lookup was successful */
370 rh->name_callback (rh->cls, NULL);
372 if (NULL != rh->addr_callback)
373 rh->addr_callback (rh->cls, NULL, 0);
375 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
377 GNUNET_CLIENT_disconnect (client);
382 if (GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE != ntohs (msg->type))
385 GNUNET_CLIENT_disconnect (client);
390 size = ntohs (msg->size);
391 /* message contains not data, just header */
392 if (size == sizeof (struct GNUNET_MessageHeader))
394 /* check if request was canceled */
395 if (rh->was_transmitted != GNUNET_SYSERR)
397 if (NULL != rh->name_callback)
398 rh->name_callback (rh->cls, NULL);
399 if (NULL != rh->addr_callback)
400 rh->addr_callback (rh->cls, NULL, 0);
402 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
407 /* return reverse lookup results to caller */
408 if (NULL != rh->name_callback)
410 const char *hostname;
412 hostname = (const char *) &msg[1];
413 if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
416 if (rh->was_transmitted != GNUNET_SYSERR)
417 rh->name_callback (rh->cls, NULL);
418 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
420 GNUNET_CLIENT_disconnect (client);
426 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s' for IP `%s'.\n"),
427 hostname, GNUNET_a2s ((const void *) &rh[1], rh->data_len));
429 if (rh->was_transmitted != GNUNET_SYSERR)
430 rh->name_callback (rh->cls, hostname);
431 rh->received_response = GNUNET_YES;
432 GNUNET_CLIENT_receive (client, &handle_response, rh,
433 GNUNET_TIME_absolute_get_remaining (rh->timeout));
435 /* return lookup results to caller */
436 if (NULL != rh->addr_callback)
438 struct sockaddr_in v4;
439 struct sockaddr_in6 v6;
440 const struct sockaddr *sa;
446 ip_len = size - sizeof (struct GNUNET_MessageHeader);
447 if (ip_len == sizeof (struct in_addr))
449 memset (&v4, 0, sizeof (v4));
450 v4.sin_family = AF_INET;
451 v4.sin_addr = *(struct in_addr*) ip;
452 #if HAVE_SOCKADDR_IN_SIN_LEN
453 v4.sin_len = sizeof (v4);
456 sa = (const struct sockaddr *) &v4;
458 else if (ip_len == sizeof (struct in6_addr))
460 memset (&v6, 0, sizeof (v6));
461 v6.sin6_family = AF_INET6;
462 v6.sin6_addr = *(struct in6_addr*) ip;
463 #if HAVE_SOCKADDR_IN_SIN_LEN
464 v6.sin6_len = sizeof (v6);
467 sa = (const struct sockaddr *) &v6;
472 if (rh->was_transmitted != GNUNET_SYSERR)
473 rh->addr_callback (rh->cls, NULL, 0);
474 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
476 GNUNET_CLIENT_disconnect (client);
481 rh->addr_callback (rh->cls, sa, salen);
482 GNUNET_CLIENT_receive (client, &handle_response, rh,
483 GNUNET_TIME_absolute_get_remaining (rh->timeout));
489 * We've been asked to lookup the address for a hostname and were
490 * given a valid numeric string. Perform the callbacks for the
493 * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
494 * @param tc unused scheduler context
497 numeric_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
499 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
500 struct sockaddr_in v4;
501 struct sockaddr_in6 v6;
502 const char *hostname;
504 memset (&v4, 0, sizeof (v4));
505 v4.sin_family = AF_INET;
506 #if HAVE_SOCKADDR_IN_SIN_LEN
507 v4.sin_len = sizeof (v4);
509 memset (&v6, 0, sizeof (v6));
510 v6.sin6_family = AF_INET6;
511 #if HAVE_SOCKADDR_IN_SIN_LEN
512 v6.sin6_len = sizeof (v6);
514 hostname = (const char *) &rh[1];
515 if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET)) &&
516 (1 == inet_pton (AF_INET, hostname, &v4.sin_addr)))
518 rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
519 if ((rh->af == AF_UNSPEC) &&
520 (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
522 /* this can happen on some systems IF "hostname" is "localhost" */
523 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
525 rh->addr_callback (rh->cls, NULL, 0);
529 if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET6)) &&
530 (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
532 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
533 rh->addr_callback (rh->cls, NULL, 0);
537 /* why are we here? this task should not have been scheduled! */
544 * We've been asked to lookup the address for a hostname and were
545 * given a variant of "loopback". Perform the callbacks for the
546 * respective loopback numeric addresses.
548 * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
549 * @param tc unused scheduler context
552 loopback_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
554 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
555 struct sockaddr_in v4;
556 struct sockaddr_in6 v6;
558 memset (&v4, 0, sizeof (v4));
559 v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
560 v4.sin_family = AF_INET;
561 #if HAVE_SOCKADDR_IN_SIN_LEN
562 v4.sin_len = sizeof (v4);
564 memset (&v6, 0, sizeof (v6));
565 v6.sin6_family = AF_INET6;
566 #if HAVE_SOCKADDR_IN_SIN_LEN
567 v6.sin6_len = sizeof (v6);
569 v6.sin6_addr = in6addr_loopback;
573 rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
576 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
579 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
580 rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
586 rh->addr_callback (rh->cls, NULL, 0);
592 * Task executed on system shutdown.
595 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
597 s_task = GNUNET_SCHEDULER_NO_TASK;
598 GNUNET_RESOLVER_disconnect ();
603 * Process pending requests to the resolver.
608 struct GNUNET_RESOLVER_GetMessage *msg;
609 char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1] GNUNET_ALIGN;
610 struct GNUNET_RESOLVER_RequestHandle *rh;
620 /* nothing to do, release socket really soon if there is nothing
621 * else happening... */
623 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS,
624 &shutdown_task, NULL);
627 if (GNUNET_YES == rh->was_transmitted)
628 return; /* waiting for reply */
629 msg = (struct GNUNET_RESOLVER_GetMessage *) buf;
631 htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + rh->data_len);
632 msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
633 msg->direction = htonl (rh->direction);
634 msg->af = htonl (rh->af);
635 memcpy (&msg[1], &rh[1], rh->data_len);
637 LOG (GNUNET_ERROR_TYPE_DEBUG,
638 "Transmitting DNS resolution request to DNS service\n");
641 GNUNET_CLIENT_transmit_and_get_response (client, &msg->header,
642 GNUNET_TIME_absolute_get_remaining
643 (rh->timeout), GNUNET_YES,
644 &handle_response, rh))
646 GNUNET_CLIENT_disconnect (client);
651 rh->was_transmitted = GNUNET_YES;
656 * Now try to reconnect to the resolver service.
659 * @param tc scheduler context
662 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
664 r_task = GNUNET_SCHEDULER_NO_TASK;
665 if (NULL == req_head)
666 return; /* no work pending */
667 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
670 LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying to connect to DNS service\n");
672 client = GNUNET_CLIENT_connect ("resolver", resolver_cfg);
675 LOG (GNUNET_ERROR_TYPE_DEBUG, "Failed to connect, will try again later\n");
684 * Adjust exponential back-off and reconnect to the service.
689 struct GNUNET_RESOLVER_RequestHandle *rh;
691 if (GNUNET_SCHEDULER_NO_TASK != r_task)
693 GNUNET_assert (NULL == client);
694 if (NULL != (rh = req_head))
696 switch (rh->was_transmitted)
699 /* nothing more to do */
702 /* disconnected, transmit again! */
703 rh->was_transmitted = GNUNET_NO;
706 /* request was cancelled, remove entirely */
707 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
716 LOG (GNUNET_ERROR_TYPE_DEBUG,
717 "Will try to connect to DNS service in %llu ms\n",
718 (unsigned long long) backoff.rel_value);
720 GNUNET_assert (NULL != resolver_cfg);
721 r_task = GNUNET_SCHEDULER_add_delayed (backoff, &reconnect_task, NULL);
722 backoff = GNUNET_TIME_relative_multiply (backoff, 2);
727 * Convert a string to one or more IP addresses.
729 * @param hostname the hostname to resolve
730 * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
731 * @param callback function to call with addresses
732 * @param callback_cls closure for callback
733 * @param timeout how long to try resolving
734 * @return handle that can be used to cancel the request, NULL on error
736 struct GNUNET_RESOLVER_RequestHandle *
737 GNUNET_RESOLVER_ip_get (const char *hostname, int af,
738 struct GNUNET_TIME_Relative timeout,
739 GNUNET_RESOLVER_AddressCallback callback,
742 struct GNUNET_RESOLVER_RequestHandle *rh;
748 slen = strlen (hostname) + 1;
749 if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >=
750 GNUNET_SERVER_MAX_MESSAGE_SIZE)
755 rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + slen);
757 rh->addr_callback = callback;
758 rh->cls = callback_cls;
759 memcpy (&rh[1], hostname, slen);
761 rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
762 rh->direction = GNUNET_NO;
763 /* first, check if this is a numeric address */
764 if (((1 == inet_pton (AF_INET, hostname, &v4)) &&
765 ((af == AF_INET) || (af == AF_UNSPEC))) ||
766 ((1 == inet_pton (AF_INET6, hostname, &v6)) &&
767 ((af == AF_INET6) || (af == AF_UNSPEC))))
769 rh->task = GNUNET_SCHEDULER_add_now (&numeric_resolution, rh);
772 /* then, check if this is a loopback address */
774 while (loopback[i] != NULL)
775 if (0 == strcasecmp (loopback[i++], hostname))
777 rh->task = GNUNET_SCHEDULER_add_now (&loopback_resolution, rh);
780 GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh);
781 rh->was_queued = GNUNET_YES;
782 if (s_task != GNUNET_SCHEDULER_NO_TASK)
784 GNUNET_SCHEDULER_cancel (s_task);
785 s_task = GNUNET_SCHEDULER_NO_TASK;
793 * We've been asked to convert an address to a string without
794 * a reverse lookup. Do it.
796 * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
797 * @param tc unused scheduler context
800 numeric_reverse (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
802 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
805 result = no_resolve (rh->af, &rh[1], rh->data_len);
807 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s'.\n"), result);
811 rh->name_callback (rh->cls, result);
812 GNUNET_free (result);
814 rh->name_callback (rh->cls, NULL);
820 * Get an IP address as a string.
822 * @param sa host address
823 * @param salen length of host address
824 * @param do_resolve use GNUNET_NO to return numeric hostname
825 * @param timeout how long to try resolving
826 * @param callback function to call with hostnames
827 * last callback is NULL when finished
828 * @param cls closure for callback
829 * @return handle that can be used to cancel the request
831 struct GNUNET_RESOLVER_RequestHandle *
832 GNUNET_RESOLVER_hostname_get (const struct sockaddr *sa, socklen_t salen,
834 struct GNUNET_TIME_Relative timeout,
835 GNUNET_RESOLVER_HostnameCallback callback,
838 struct GNUNET_RESOLVER_RequestHandle *rh;
843 switch (sa->sa_family)
846 ip_len = sizeof (struct in_addr);
847 ip = &((const struct sockaddr_in*)sa)->sin_addr;
850 ip_len = sizeof (struct in6_addr);
851 ip = &((const struct sockaddr_in6*)sa)->sin6_addr;
857 rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + salen);
858 rh->name_callback = callback;
860 rh->af = sa->sa_family;
861 rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
862 memcpy (&rh[1], ip, ip_len);
863 rh->data_len = ip_len;
864 rh->direction = GNUNET_YES;
865 rh->received_response = GNUNET_NO;
866 if (GNUNET_NO == do_resolve)
868 rh->task = GNUNET_SCHEDULER_add_now (&numeric_reverse, rh);
871 GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh);
872 rh->was_queued = GNUNET_YES;
873 if (s_task != GNUNET_SCHEDULER_NO_TASK)
875 GNUNET_SCHEDULER_cancel (s_task);
876 s_task = GNUNET_SCHEDULER_NO_TASK;
884 * Get local fully qualified af name
889 GNUNET_RESOLVER_local_fqdn_get ()
891 struct hostent *host;
892 char hostname[GNUNET_OS_get_hostname_max_length () + 1];
894 if (0 != gethostname (hostname, sizeof (hostname) - 1))
896 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
901 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolving our FQDN `%s'\n"), hostname);
903 host = gethostbyname (hostname);
906 LOG (GNUNET_ERROR_TYPE_ERROR, _("Could not resolve our FQDN : %s\n"),
907 hstrerror (h_errno));
910 return GNUNET_strdup (host->h_name);
915 * Looking our own hostname.
917 * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
918 * @param callback function to call with addresses
919 * @param cls closure for callback
920 * @param timeout how long to try resolving
921 * @return handle that can be used to cancel the request, NULL on error
923 struct GNUNET_RESOLVER_RequestHandle *
924 GNUNET_RESOLVER_hostname_resolve (int af,
925 struct GNUNET_TIME_Relative timeout,
926 GNUNET_RESOLVER_AddressCallback callback,
929 char hostname[GNUNET_OS_get_hostname_max_length () + 1];
931 if (0 != gethostname (hostname, sizeof (hostname) - 1))
933 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
938 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolving our hostname `%s'\n"), hostname);
940 return GNUNET_RESOLVER_ip_get (hostname, af, timeout, callback, cls);
945 * Cancel a request that is still pending with the resolver.
946 * Note that a client MUST NOT cancel a request that has
947 * been completed (i.e, the callback has been called to
948 * signal timeout or the final result).
950 * @param rh handle of request to cancel
953 GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *rh)
955 if (rh->task != GNUNET_SCHEDULER_NO_TASK)
957 GNUNET_SCHEDULER_cancel (rh->task);
958 rh->task = GNUNET_SCHEDULER_NO_TASK;
960 if (rh->was_transmitted == GNUNET_NO)
962 if (rh->was_queued == GNUNET_YES)
963 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
967 GNUNET_assert (rh->was_transmitted == GNUNET_YES);
968 rh->was_transmitted = GNUNET_SYSERR; /* mark as cancelled */
972 /* end of resolver_api.c */