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, GNUNET_NO);
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 sa the address
276 * @param salen number of bytes in sa
277 * @return address as a string, NULL on error
280 no_resolve (const struct sockaddr *sa, socklen_t salen)
283 char inet4[INET_ADDRSTRLEN];
284 char inet6[INET6_ADDRSTRLEN];
286 if (salen < sizeof (struct sockaddr))
288 switch (sa->sa_family)
291 if (salen != sizeof (struct sockaddr_in))
294 inet_ntop (AF_INET, &((struct sockaddr_in *) sa)->sin_addr, inet4,
297 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "inet_ntop");
300 ret = GNUNET_strdup (inet4);
303 if (salen != sizeof (struct sockaddr_in6))
306 inet_ntop (AF_INET6, &((struct sockaddr_in6 *) sa)->sin6_addr, inet6,
309 LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "inet_ntop");
312 ret = GNUNET_strdup (inet6);
323 * Adjust exponential back-off and reconnect to the service.
330 * Process pending requests to the resolver.
337 * Process response with a hostname for a DNS lookup.
339 * @param cls our "struct GNUNET_RESOLVER_RequestHandle" context
340 * @param msg message with the hostname, NULL on error
343 handle_response (void *cls, const struct GNUNET_MessageHeader *msg)
345 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
349 LOG (GNUNET_ERROR_TYPE_DEBUG, "Receiving response from DNS service\n");
353 char buf[INET6_ADDRSTRLEN];
355 if (NULL != rh->name_callback)
356 LOG (GNUNET_ERROR_TYPE_INFO,
357 _("Timeout trying to resolve IP address `%s'.\n"),
358 inet_ntop (rh->af, (const void *) &rh[1], buf, sizeof(buf)));
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 (rh->was_transmitted != GNUNET_SYSERR)
366 if (NULL != rh->name_callback)
368 /* no reverse lookup was successful, return ip as string */
369 if (rh->received_response == GNUNET_NO)
370 rh->name_callback (rh->cls,
371 no_resolve ((const struct sockaddr *) &rh[1],
373 /* at least one reverse lookup was successful */
375 rh->name_callback (rh->cls, NULL);
377 if (NULL != rh->addr_callback)
378 rh->addr_callback (rh->cls, NULL, 0);
380 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
382 GNUNET_CLIENT_disconnect (client, GNUNET_NO);
387 if (GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE != ntohs (msg->type))
390 GNUNET_CLIENT_disconnect (client, GNUNET_NO);
395 size = ntohs (msg->size);
396 /* message contains not data, just header */
397 if (size == sizeof (struct GNUNET_MessageHeader))
399 /* check if request was canceled */
400 if (rh->was_transmitted != GNUNET_SYSERR)
402 if (NULL != rh->name_callback)
403 rh->name_callback (rh->cls, NULL);
404 if (NULL != rh->addr_callback)
405 rh->addr_callback (rh->cls, NULL, 0);
407 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
412 /* return reverse lookup results to caller */
413 if (NULL != rh->name_callback)
415 const char *hostname;
417 hostname = (const char *) &msg[1];
418 if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
421 if (rh->was_transmitted != GNUNET_SYSERR)
422 rh->name_callback (rh->cls, NULL);
423 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
425 GNUNET_CLIENT_disconnect (client, GNUNET_NO);
431 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s' for IP `%s'.\n"),
432 hostname, GNUNET_a2s ((const void *) &rh[1], rh->data_len));
434 if (rh->was_transmitted != GNUNET_SYSERR)
435 rh->name_callback (rh->cls, hostname);
436 rh->received_response = GNUNET_YES;
437 GNUNET_CLIENT_receive (client, &handle_response, rh,
438 GNUNET_TIME_absolute_get_remaining (rh->timeout));
440 /* return lookup results to caller */
441 if (NULL != rh->addr_callback)
443 struct sockaddr_in v4;
444 struct sockaddr_in6 v6;
445 const struct sockaddr *sa;
451 ip_len = size - sizeof (struct GNUNET_MessageHeader);
452 if (ip_len == sizeof (struct in_addr))
454 memset (&v4, 0, sizeof (v4));
455 v4.sin_family = AF_INET;
456 v4.sin_addr = *(struct in_addr*) ip;
457 #if HAVE_SOCKADDR_IN_SIN_LEN
458 v4.sin_len = sizeof (v4);
461 sa = (const struct sockaddr *) &v4;
463 else if (ip_len == sizeof (struct in6_addr))
465 memset (&v6, 0, sizeof (v6));
466 v6.sin6_family = AF_INET6;
467 v6.sin6_addr = *(struct in6_addr*) ip;
468 #if HAVE_SOCKADDR_IN_SIN_LEN
469 v6.sin6_len = sizeof (v6);
472 sa = (const struct sockaddr *) &v6;
477 if (rh->was_transmitted != GNUNET_SYSERR)
478 rh->addr_callback (rh->cls, NULL, 0);
479 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
481 GNUNET_CLIENT_disconnect (client, GNUNET_NO);
488 char *ips = no_resolve (sa, salen);
490 LOG (GNUNET_ERROR_TYPE_DEBUG, "Resolver returns `%s' for `%s'.\n", ips,
491 (const char *) &rh[1]);
495 rh->addr_callback (rh->cls, sa, salen);
496 GNUNET_CLIENT_receive (client, &handle_response, rh,
497 GNUNET_TIME_absolute_get_remaining (rh->timeout));
503 * We've been asked to lookup the address for a hostname and were
504 * given a valid numeric string. Perform the callbacks for the
507 * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
508 * @param tc unused scheduler context
511 numeric_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
513 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
514 struct sockaddr_in v4;
515 struct sockaddr_in6 v6;
516 const char *hostname;
518 memset (&v4, 0, sizeof (v4));
519 v4.sin_family = AF_INET;
520 #if HAVE_SOCKADDR_IN_SIN_LEN
521 v4.sin_len = sizeof (v4);
523 memset (&v6, 0, sizeof (v6));
524 v6.sin6_family = AF_INET6;
525 #if HAVE_SOCKADDR_IN_SIN_LEN
526 v6.sin6_len = sizeof (v6);
528 hostname = (const char *) &rh[1];
529 if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET)) &&
530 (1 == inet_pton (AF_INET, hostname, &v4.sin_addr)))
532 rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
533 if ((rh->af == AF_UNSPEC) &&
534 (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
536 /* this can happen on some systems IF "hostname" is "localhost" */
537 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
539 rh->addr_callback (rh->cls, NULL, 0);
543 if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET6)) &&
544 (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
546 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
547 rh->addr_callback (rh->cls, NULL, 0);
551 /* why are we here? this task should not have been scheduled! */
558 * We've been asked to lookup the address for a hostname and were
559 * given a variant of "loopback". Perform the callbacks for the
560 * respective loopback numeric addresses.
562 * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
563 * @param tc unused scheduler context
566 loopback_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
568 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
569 struct sockaddr_in v4;
570 struct sockaddr_in6 v6;
572 memset (&v4, 0, sizeof (v4));
573 v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
574 v4.sin_family = AF_INET;
575 #if HAVE_SOCKADDR_IN_SIN_LEN
576 v4.sin_len = sizeof (v4);
578 memset (&v6, 0, sizeof (v6));
579 v6.sin6_family = AF_INET6;
580 #if HAVE_SOCKADDR_IN_SIN_LEN
581 v6.sin6_len = sizeof (v6);
583 v6.sin6_addr = in6addr_loopback;
587 rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
590 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
593 rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
594 rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
600 rh->addr_callback (rh->cls, NULL, 0);
606 * Task executed on system shutdown.
609 shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
611 s_task = GNUNET_SCHEDULER_NO_TASK;
612 GNUNET_RESOLVER_disconnect ();
617 * Process pending requests to the resolver.
622 struct GNUNET_RESOLVER_GetMessage *msg;
623 char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1];
624 struct GNUNET_RESOLVER_RequestHandle *rh;
634 /* nothing to do, release socket really soon if there is nothing
635 * else happening... */
637 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS,
638 &shutdown_task, NULL);
641 if (GNUNET_YES == rh->was_transmitted)
642 return; /* waiting for reply */
643 msg = (struct GNUNET_RESOLVER_GetMessage *) buf;
645 htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + rh->data_len);
646 msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
647 msg->direction = htonl (rh->direction);
648 msg->af = htonl (rh->af);
649 memcpy (&msg[1], &rh[1], rh->data_len);
651 LOG (GNUNET_ERROR_TYPE_DEBUG,
652 "Transmitting DNS resolution request to DNS service\n");
655 GNUNET_CLIENT_transmit_and_get_response (client, &msg->header,
656 GNUNET_TIME_absolute_get_remaining
657 (rh->timeout), GNUNET_YES,
658 &handle_response, rh))
660 GNUNET_CLIENT_disconnect (client, GNUNET_NO);
665 rh->was_transmitted = GNUNET_YES;
670 * Now try to reconnect to the resolver service.
673 * @param tc scheduler context
676 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
678 r_task = GNUNET_SCHEDULER_NO_TASK;
679 if (NULL == req_head)
680 return; /* no work pending */
681 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
684 LOG (GNUNET_ERROR_TYPE_DEBUG, "Trying to connect to DNS service\n");
686 client = GNUNET_CLIENT_connect ("resolver", resolver_cfg);
689 LOG (GNUNET_ERROR_TYPE_DEBUG, "Failed to connect, will try again later\n");
698 * Adjust exponential back-off and reconnect to the service.
703 struct GNUNET_RESOLVER_RequestHandle *rh;
705 if (GNUNET_SCHEDULER_NO_TASK != r_task)
707 GNUNET_assert (NULL == client);
708 if (NULL != (rh = req_head))
710 switch (rh->was_transmitted)
713 /* nothing more to do */
716 /* disconnected, transmit again! */
717 rh->was_transmitted = GNUNET_NO;
720 /* request was cancelled, remove entirely */
721 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
730 LOG (GNUNET_ERROR_TYPE_DEBUG,
731 "Will try to connect to DNS service in %llu ms\n",
732 (unsigned long long) backoff.rel_value);
734 GNUNET_assert (NULL != resolver_cfg);
735 r_task = GNUNET_SCHEDULER_add_delayed (backoff, &reconnect_task, NULL);
736 backoff = GNUNET_TIME_relative_multiply (backoff, 2);
741 * Convert a string to one or more IP addresses.
743 * @param hostname the hostname to resolve
744 * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
745 * @param callback function to call with addresses
746 * @param callback_cls closure for callback
747 * @param timeout how long to try resolving
748 * @return handle that can be used to cancel the request, NULL on error
750 struct GNUNET_RESOLVER_RequestHandle *
751 GNUNET_RESOLVER_ip_get (const char *hostname, int af,
752 struct GNUNET_TIME_Relative timeout,
753 GNUNET_RESOLVER_AddressCallback callback,
756 struct GNUNET_RESOLVER_RequestHandle *rh;
762 slen = strlen (hostname) + 1;
763 if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >=
764 GNUNET_SERVER_MAX_MESSAGE_SIZE)
769 rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + slen);
771 rh->addr_callback = callback;
772 rh->cls = callback_cls;
773 memcpy (&rh[1], hostname, slen);
775 rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
776 rh->direction = GNUNET_NO;
777 /* first, check if this is a numeric address */
778 if (((1 == inet_pton (AF_INET, hostname, &v4)) &&
779 ((af == AF_INET) || (af == AF_UNSPEC))) ||
780 ((1 == inet_pton (AF_INET6, hostname, &v6)) &&
781 ((af == AF_INET6) || (af == AF_UNSPEC))))
783 rh->task = GNUNET_SCHEDULER_add_now (&numeric_resolution, rh);
786 /* then, check if this is a loopback address */
788 while (loopback[i] != NULL)
789 if (0 == strcasecmp (loopback[i++], hostname))
791 rh->task = GNUNET_SCHEDULER_add_now (&loopback_resolution, rh);
794 GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh);
795 rh->was_queued = GNUNET_YES;
796 if (s_task != GNUNET_SCHEDULER_NO_TASK)
798 GNUNET_SCHEDULER_cancel (s_task);
799 s_task = GNUNET_SCHEDULER_NO_TASK;
807 * We've been asked to convert an address to a string without
808 * a reverse lookup. Do it.
810 * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
811 * @param tc unused scheduler context
814 numeric_reverse (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
816 struct GNUNET_RESOLVER_RequestHandle *rh = cls;
819 result = no_resolve ((const struct sockaddr *) &rh[1], rh->data_len);
821 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s'.\n"), result);
825 rh->name_callback (rh->cls, result);
826 GNUNET_free (result);
828 rh->name_callback (rh->cls, NULL);
834 * Get an IP address as a string.
836 * @param sa host address
837 * @param salen length of host address
838 * @param do_resolve use GNUNET_NO to return numeric hostname
839 * @param timeout how long to try resolving
840 * @param callback function to call with hostnames
841 * last callback is NULL when finished
842 * @param cls closure for callback
843 * @return handle that can be used to cancel the request
845 struct GNUNET_RESOLVER_RequestHandle *
846 GNUNET_RESOLVER_hostname_get (const struct sockaddr *sa, socklen_t salen,
848 struct GNUNET_TIME_Relative timeout,
849 GNUNET_RESOLVER_HostnameCallback callback,
852 struct GNUNET_RESOLVER_RequestHandle *rh;
857 switch (sa->sa_family)
860 ip_len = sizeof (struct in_addr);
861 ip = &((const struct sockaddr_in*)sa)->sin_addr;
864 ip_len = sizeof (struct in6_addr);
865 ip = &((const struct sockaddr_in6*)sa)->sin6_addr;
871 rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + salen);
872 rh->name_callback = callback;
874 rh->af = sa->sa_family;
875 rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
876 memcpy (&rh[1], ip, ip_len);
877 rh->data_len = ip_len;
878 rh->direction = GNUNET_YES;
879 rh->received_response = GNUNET_NO;
880 if (GNUNET_NO == do_resolve)
882 rh->task = GNUNET_SCHEDULER_add_now (&numeric_reverse, rh);
885 GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh);
886 rh->was_queued = GNUNET_YES;
887 if (s_task != GNUNET_SCHEDULER_NO_TASK)
889 GNUNET_SCHEDULER_cancel (s_task);
890 s_task = GNUNET_SCHEDULER_NO_TASK;
898 * Get local fully qualified af name
903 GNUNET_RESOLVER_local_fqdn_get ()
905 struct hostent *host;
906 char hostname[GNUNET_OS_get_hostname_max_length () + 1];
908 if (0 != gethostname (hostname, sizeof (hostname) - 1))
910 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
915 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolving our FQDN `%s'\n"), hostname);
917 host = gethostbyname (hostname);
920 LOG (GNUNET_ERROR_TYPE_ERROR, _("Could not resolve our FQDN : %s\n"),
921 hstrerror (h_errno));
924 return GNUNET_strdup (host->h_name);
929 * Looking our own hostname.
931 * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
932 * @param callback function to call with addresses
933 * @param cls closure for callback
934 * @param timeout how long to try resolving
935 * @return handle that can be used to cancel the request, NULL on error
937 struct GNUNET_RESOLVER_RequestHandle *
938 GNUNET_RESOLVER_hostname_resolve (int af,
939 struct GNUNET_TIME_Relative timeout,
940 GNUNET_RESOLVER_AddressCallback callback,
943 char hostname[GNUNET_OS_get_hostname_max_length () + 1];
945 if (0 != gethostname (hostname, sizeof (hostname) - 1))
947 LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
952 LOG (GNUNET_ERROR_TYPE_DEBUG, _("Resolving our hostname `%s'\n"), hostname);
954 return GNUNET_RESOLVER_ip_get (hostname, af, timeout, callback, cls);
959 * Cancel a request that is still pending with the resolver.
960 * Note that a client MUST NOT cancel a request that has
961 * been completed (i.e, the callback has been called to
962 * signal timeout or the final result).
964 * @param rh handle of request to cancel
967 GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *rh)
969 if (rh->task != GNUNET_SCHEDULER_NO_TASK)
971 GNUNET_SCHEDULER_cancel (rh->task);
972 rh->task = GNUNET_SCHEDULER_NO_TASK;
974 if (rh->was_transmitted == GNUNET_NO)
976 if (rh->was_queued == GNUNET_YES)
977 GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
981 GNUNET_assert (rh->was_transmitted == GNUNET_YES);
982 rh->was_transmitted = GNUNET_SYSERR; /* mark as cancelled */
986 /* end of resolver_api.c */