/* This file is part of GNUnet. (C) 2009 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file util/resolver_api.c * @brief resolver for writing a tool * @author Christian Grothoff */ #include "platform.h" #include "gnunet_getopt_lib.h" #include "gnunet_os_lib.h" #include "gnunet_client_lib.h" #include "gnunet_container_lib.h" #include "gnunet_protocols.h" #include "gnunet_resolver_service.h" #include "gnunet_server_lib.h" #include "resolver.h" /** * Maximum supported length for a hostname */ #define MAX_HOSTNAME 1024 /** * Possible hostnames for "loopback". */ static const char *loopback[] = { "localhost", "ip6-localnet", NULL }; /** * Configuration. */ static const struct GNUNET_CONFIGURATION_Handle *cfg; /** * Our connection to the resolver service, created on-demand, but then * persists until error or shutdown. */ static struct GNUNET_CLIENT_Connection *client; /** * Head of DLL of requests. */ static struct GNUNET_RESOLVER_RequestHandle *req_head; /** * Tail of DLL of requests. */ static struct GNUNET_RESOLVER_RequestHandle *req_tail; /** * How long should we wait to reconnect? */ static struct GNUNET_TIME_Relative backoff; /** * Task for reconnecting. */ static GNUNET_SCHEDULER_TaskIdentifier r_task; /** * Task ID of shutdown task; only present while we have a * connection to the resolver service. */ static GNUNET_SCHEDULER_TaskIdentifier s_task; /** * Handle to a request given to the resolver. Can be used to cancel * the request prior to the timeout or successful execution. Also * used to track our internal state for the request. */ struct GNUNET_RESOLVER_RequestHandle { /** * Next entry in DLL of requests. */ struct GNUNET_RESOLVER_RequestHandle *next; /** * Previous entry in DLL of requests. */ struct GNUNET_RESOLVER_RequestHandle *prev; /** * Callback if this is an name resolution request, * otherwise NULL. */ GNUNET_RESOLVER_AddressCallback addr_callback; /** * Callback if this is a reverse lookup request, * otherwise NULL. */ GNUNET_RESOLVER_HostnameCallback name_callback; /** * Closure for the respective "callback". */ void *cls; /** * When should this request time out? */ struct GNUNET_TIME_Absolute timeout; /** * Task handle for numeric lookups. */ GNUNET_SCHEDULER_TaskIdentifier task; /** * Desired address family. */ int domain; /** * Has this request been transmitted to the service? */ int was_transmitted; /** * Did we add this request to the queue? */ int was_queued; /** * Desired direction (IP to name or name to IP) */ int direction; /** * Length of the data that follows this struct. */ size_t data_len; }; /** * Check that the resolver service runs on localhost * (or equivalent). */ static void check_config (const struct GNUNET_CONFIGURATION_Handle *cfg) { char *hostname; unsigned int i; struct sockaddr_in v4; struct sockaddr_in6 v6; memset (&v4, 0, sizeof (v4)); v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK); v4.sin_family = AF_INET; #if HAVE_SOCKADDR_IN_SIN_LEN v4.sin_len = sizeof (v4); #endif memset (&v6, 0, sizeof (v6)); v6.sin6_family = AF_INET6; #if HAVE_SOCKADDR_IN_SIN_LEN v6.sin6_len = sizeof (v6); #endif if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (cfg, "resolver", "HOSTNAME", &hostname)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Must specify `%s' for `%s' in configuration!\n"), "HOSTNAME", "resolver"); GNUNET_assert (0); } if ((1 != inet_pton (AF_INET, hostname, &v4)) || (1 != inet_pton (AF_INET6, hostname, &v6))) { GNUNET_free (hostname); return; } i = 0; while (loopback[i] != NULL) if (0 == strcasecmp (loopback[i++], hostname)) { GNUNET_free (hostname); return; } GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _ ("Must specify `%s' or numeric IP address for `%s' of `%s' in configuration!\n"), "localhost", "HOSTNAME", "resolver"); GNUNET_free (hostname); GNUNET_assert (0); } /** * Create the connection to the resolver service. * * @param c configuration to use */ void GNUNET_RESOLVER_connect (const struct GNUNET_CONFIGURATION_Handle *c) { check_config (c); cfg = c; } /** * Destroy the connection to the resolver service. */ void GNUNET_RESOLVER_disconnect () { GNUNET_assert (NULL == req_head); GNUNET_assert (NULL == req_tail); if (NULL != client) { GNUNET_CLIENT_disconnect (client, GNUNET_NO); client = NULL; } if (r_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (r_task); r_task = GNUNET_SCHEDULER_NO_TASK; } if (s_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (s_task); s_task = GNUNET_SCHEDULER_NO_TASK; } } /** * Convert IP address to string without DNS resolution. * * @param sa the address * @param salen number of bytes in sa * @return address as a string, NULL on error */ static char * no_resolve (const struct sockaddr *sa, socklen_t salen) { char *ret; char inet4[INET_ADDRSTRLEN]; char inet6[INET6_ADDRSTRLEN]; if (salen < sizeof (struct sockaddr)) return NULL; switch (sa->sa_family) { case AF_INET: if (salen != sizeof (struct sockaddr_in)) return NULL; if (NULL == inet_ntop (AF_INET, &((struct sockaddr_in *) sa)->sin_addr, inet4, INET_ADDRSTRLEN)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "inet_ntop"); return NULL; } ret = GNUNET_strdup (inet4); break; case AF_INET6: if (salen != sizeof (struct sockaddr_in6)) return NULL; if (NULL == inet_ntop (AF_INET6, &((struct sockaddr_in6 *) sa)->sin6_addr, inet6, INET6_ADDRSTRLEN)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "inet_ntop"); return NULL; } ret = GNUNET_strdup (inet6); break; default: ret = NULL; break; } return ret; } /** * Adjust exponential back-off and reconnect to the service. */ static void reconnect (); /** * Process pending requests to the resolver. * * @param h handle to the resolver */ static void process_requests (); /** * Process response with a hostname for a DNS lookup. * * @param cls our "struct GNUNET_RESOLVER_RequestHandle" context * @param msg message with the hostname, NULL on error */ static void handle_response (void *cls, const struct GNUNET_MessageHeader *msg) { struct GNUNET_RESOLVER_RequestHandle *rh = cls; uint16_t size; const char *hostname; const struct sockaddr *sa; socklen_t salen; if (msg == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Timeout trying to resolve IP address `%s'.\n"), GNUNET_a2s ((const void*) &rh[1], rh->data_len)); if (rh->was_transmitted != GNUNET_SYSERR) { if (NULL != rh->name_callback) rh->name_callback (rh->cls, NULL); if (NULL != rh->addr_callback) rh->addr_callback (rh->cls, NULL, 0); } GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh); GNUNET_free (rh); GNUNET_CLIENT_disconnect (client, GNUNET_NO); client = NULL; reconnect (); return; } if (GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE != ntohs (msg->type)) { GNUNET_break (0); GNUNET_CLIENT_disconnect (client, GNUNET_NO); client = NULL; reconnect (); return; } size = ntohs (msg->size); if (size == sizeof (struct GNUNET_MessageHeader)) { if (rh->was_transmitted != GNUNET_SYSERR) { if (NULL != rh->name_callback) rh->name_callback (rh->cls, NULL); if (NULL != rh->addr_callback) rh->addr_callback (rh->cls, NULL, 0); } GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh); GNUNET_free (rh); process_requests (); return; } if (NULL != rh->name_callback) { hostname = (const char *) &msg[1]; if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0') { GNUNET_break (0); if (rh->was_transmitted != GNUNET_SYSERR) rh->name_callback (rh->cls, NULL); GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh); GNUNET_free (rh); GNUNET_CLIENT_disconnect (client, GNUNET_NO); client = NULL; reconnect (); return; } #if DEBUG_RESOLVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s' for IP `%s'.\n"), hostname, GNUNET_a2s ((const void*) &rh[1], rh->data_len)); #endif if (rh->was_transmitted != GNUNET_SYSERR) rh->name_callback (rh->cls, hostname); GNUNET_CLIENT_receive (client, &handle_response, rh, GNUNET_TIME_absolute_get_remaining (rh->timeout)); } if (NULL != rh->addr_callback) { sa = (const struct sockaddr *) &msg[1]; salen = size - sizeof (struct GNUNET_MessageHeader); if (salen < sizeof (struct sockaddr)) { GNUNET_break (0); if (rh->was_transmitted != GNUNET_SYSERR) rh->addr_callback (rh->cls, NULL, 0); GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh); GNUNET_free (rh); GNUNET_CLIENT_disconnect (client, GNUNET_NO); client = NULL; reconnect (); return; } #if DEBUG_RESOLVER { char *ips = no_resolve (sa, salen); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Resolver returns `%s' for `%s'.\n", ips, rh->hostname); GNUNET_free (ips); } #endif rh->addr_callback (rh->cls, sa, salen); GNUNET_CLIENT_receive (client, &handle_response, rh, GNUNET_TIME_absolute_get_remaining (rh->timeout)); } } /** * We've been asked to lookup the address for a hostname and were * given a valid numeric string. Perform the callbacks for the * numeric addresses. * * @param cls struct GNUNET_RESOLVER_RequestHandle for the request * @param tc unused scheduler context */ static void numeric_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_RESOLVER_RequestHandle *rh = cls; struct sockaddr_in v4; struct sockaddr_in6 v6; const char *hostname; memset (&v4, 0, sizeof (v4)); v4.sin_family = AF_INET; #if HAVE_SOCKADDR_IN_SIN_LEN v4.sin_len = sizeof (v4); #endif memset (&v6, 0, sizeof (v6)); v6.sin6_family = AF_INET6; #if HAVE_SOCKADDR_IN_SIN_LEN v6.sin6_len = sizeof (v6); #endif hostname = (const char*) &rh[1]; if (((rh->domain == AF_UNSPEC) || (rh->domain == AF_INET)) && (1 == inet_pton (AF_INET, hostname, &v4.sin_addr))) { rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4)); if ((rh->domain == AF_UNSPEC) && (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr))) { /* this can happen on some systems IF "hostname" is "localhost" */ rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6)); } rh->addr_callback (rh->cls, NULL, 0); GNUNET_free (rh); return; } if (((rh->domain == AF_UNSPEC) || (rh->domain == AF_INET6)) && (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr))) { rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6)); rh->addr_callback (rh->cls, NULL, 0); GNUNET_free (rh); return; } /* why are we here? this task should not have been scheduled! */ GNUNET_assert (0); GNUNET_free (rh); } /** * We've been asked to lookup the address for a hostname and were * given a variant of "loopback". Perform the callbacks for the * respective loopback numeric addresses. * * @param cls struct GNUNET_RESOLVER_RequestHandle for the request * @param tc unused scheduler context */ static void loopback_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_RESOLVER_RequestHandle *rh = cls; struct sockaddr_in v4; struct sockaddr_in6 v6; memset (&v4, 0, sizeof (v4)); v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK); v4.sin_family = AF_INET; #if HAVE_SOCKADDR_IN_SIN_LEN v4.sin_len = sizeof (v4); #endif memset (&v6, 0, sizeof (v6)); v6.sin6_family = AF_INET6; #if HAVE_SOCKADDR_IN_SIN_LEN v6.sin6_len = sizeof (v6); #endif v6.sin6_addr = in6addr_loopback; switch (rh->domain) { case AF_INET: rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4)); break; case AF_INET6: rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6)); break; case AF_UNSPEC: rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6)); rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4)); break; default: GNUNET_break (0); break; } rh->addr_callback (rh->cls, NULL, 0); GNUNET_free (rh); } /** * Task executed on system shutdown. */ static void shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { s_task = GNUNET_SCHEDULER_NO_TASK; GNUNET_RESOLVER_disconnect (); } /** * Process pending requests to the resolver. * * @param h handle to the resolver */ static void process_requests () { struct GNUNET_RESOLVER_GetMessage *msg; char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1]; struct GNUNET_RESOLVER_RequestHandle *rh; if (NULL == client) { reconnect (); return; } rh = req_head; if (NULL == rh) { /* nothing to do, release socket really soon if there is nothing else happening... */ s_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS, &shutdown_task, NULL); return; } if (GNUNET_YES == rh->was_transmitted) return; /* waiting for reply */ msg = (struct GNUNET_RESOLVER_GetMessage *) buf; msg->header.size = htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + rh->data_len); msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST); msg->direction = htonl (rh->direction); msg->domain = htonl (rh->domain); memcpy (&msg[1], &rh[1], rh->data_len); if (GNUNET_OK != GNUNET_CLIENT_transmit_and_get_response (client, &msg->header, GNUNET_TIME_absolute_get_remaining (rh->timeout), GNUNET_YES, &handle_response, rh)) { GNUNET_CLIENT_disconnect (client, GNUNET_NO); client = NULL; reconnect (); return; } rh->was_transmitted = GNUNET_YES; } /** * Now try to reconnect to the resolver service. * * @param cls NULL * @param tc scheduler context */ static void reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { r_task = GNUNET_SCHEDULER_NO_TASK; if (NULL == req_head) return; /* no work pending */ if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; client = GNUNET_CLIENT_connect ("resolver", cfg); if (NULL == client) { reconnect (); return; } process_requests (); } /** * Adjust exponential back-off and reconnect to the service. */ static void reconnect () { struct GNUNET_RESOLVER_RequestHandle *rh; if (GNUNET_SCHEDULER_NO_TASK != r_task) return; GNUNET_assert (NULL == client); if (NULL != (rh = req_head)) { switch (rh->was_transmitted) { case GNUNET_NO: /* nothing more to do */ break; case GNUNET_YES: /* disconnected, transmit again! */ rh->was_transmitted = GNUNET_NO; break; case GNUNET_SYSERR: /* request was cancelled, remove entirely */ GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh); GNUNET_free (rh); break; default: GNUNET_assert (0); break; } } r_task = GNUNET_SCHEDULER_add_delayed (backoff, &reconnect_task, NULL); backoff = GNUNET_TIME_relative_max (GNUNET_TIME_UNIT_SECONDS, GNUNET_TIME_relative_multiply (backoff, 2)); } /** * Convert a string to one or more IP addresses. * * @param hostname the hostname to resolve * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any" * @param callback function to call with addresses * @param callback_cls closure for callback * @param timeout how long to try resolving * @return handle that can be used to cancel the request, NULL on error */ struct GNUNET_RESOLVER_RequestHandle * GNUNET_RESOLVER_ip_get (const char *hostname, int domain, struct GNUNET_TIME_Relative timeout, GNUNET_RESOLVER_AddressCallback callback, void *callback_cls) { struct GNUNET_RESOLVER_RequestHandle *rh; size_t slen; unsigned int i; struct in_addr v4; struct in6_addr v6; slen = strlen (hostname) + 1; if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break (0); return NULL; } rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + slen); rh->domain = domain; rh->addr_callback = callback; rh->cls = callback_cls; memcpy (&rh[1], hostname, slen); rh->data_len = slen; rh->timeout = GNUNET_TIME_relative_to_absolute (timeout); rh->direction = GNUNET_NO; /* first, check if this is a numeric address */ if (((1 == inet_pton (AF_INET, hostname, &v4)) && ((domain == AF_INET) || (domain == AF_UNSPEC))) || ((1 == inet_pton (AF_INET6, hostname, &v6)) && ((domain == AF_INET6) || (domain == AF_UNSPEC)))) { rh->task = GNUNET_SCHEDULER_add_now (&numeric_resolution, rh); return rh; } /* then, check if this is a loopback address */ i = 0; while (loopback[i] != NULL) if (0 == strcasecmp (loopback[i++], hostname)) { rh->task = GNUNET_SCHEDULER_add_now (&loopback_resolution, rh); return rh; } GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh); rh->was_queued = GNUNET_YES; if (s_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (s_task); s_task = GNUNET_SCHEDULER_NO_TASK; } process_requests (); return rh; } /** * We've been asked to convert an address to a string without * a reverse lookup. Do it. * * @param cls struct GNUNET_RESOLVER_RequestHandle for the request * @param tc unused scheduler context */ static void numeric_reverse (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_RESOLVER_RequestHandle *rh = cls; char *result; result = no_resolve ((const struct sockaddr *) &rh[1], rh->data_len); #if DEBUG_RESOLVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s'.\n"), result); #endif if (result != NULL) { rh->name_callback (rh->cls, result); GNUNET_free (result); } rh->name_callback (rh->cls, NULL); GNUNET_free (rh); } /** * Get an IP address as a string. * * @param sa host address * @param salen length of host address * @param do_resolve use GNUNET_NO to return numeric hostname * @param timeout how long to try resolving * @param callback function to call with hostnames * @param cls closure for callback * @return handle that can be used to cancel the request */ struct GNUNET_RESOLVER_RequestHandle * GNUNET_RESOLVER_hostname_get (const struct sockaddr *sa, socklen_t salen, int do_resolve, struct GNUNET_TIME_Relative timeout, GNUNET_RESOLVER_HostnameCallback callback, void *cls) { struct GNUNET_RESOLVER_RequestHandle *rh; check_config (cfg); rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + salen); rh->name_callback = callback; rh->cls = cls; rh->timeout = GNUNET_TIME_relative_to_absolute (timeout); memcpy (&rh[1], sa, salen); rh->data_len = salen; rh->direction = GNUNET_YES; if (GNUNET_NO == do_resolve) { rh->task = GNUNET_SCHEDULER_add_now (&numeric_reverse, rh); return rh; } if (salen + sizeof (struct GNUNET_RESOLVER_GetMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break (0); GNUNET_free (rh); return NULL; } GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh); rh->was_queued = GNUNET_YES; if (s_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (s_task); s_task = GNUNET_SCHEDULER_NO_TASK; } process_requests (); return rh; } /** * Get local fully qualified domain name * * @return fqdn */ char * GNUNET_RESOLVER_local_fqdn_get () { struct hostent *host; char hostname[GNUNET_OS_get_hostname_max_length() + 1]; if (0 != gethostname (hostname, sizeof (hostname) - 1)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, "gethostname"); return NULL; } #if DEBUG_RESOLVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Resolving our FQDN `%s'\n"), hostname); #endif host = gethostbyname (hostname); if (NULL == host) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not resolve our FQDN : %s\n"), hstrerror (h_errno)); return NULL; } return GNUNET_strdup (host->h_name); } /** * Looking our own hostname. * * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any" * @param callback function to call with addresses * @param cls closure for callback * @param timeout how long to try resolving * @return handle that can be used to cancel the request, NULL on error */ struct GNUNET_RESOLVER_RequestHandle * GNUNET_RESOLVER_hostname_resolve (int domain, struct GNUNET_TIME_Relative timeout, GNUNET_RESOLVER_AddressCallback callback, void *cls) { char hostname[GNUNET_OS_get_hostname_max_length() + 1]; if (0 != gethostname (hostname, sizeof (hostname) - 1)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, "gethostname"); return NULL; } #if DEBUG_RESOLVER GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Resolving our hostname `%s'\n"), hostname); #endif return GNUNET_RESOLVER_ip_get (hostname, domain, timeout, callback, cls); } /** * Cancel a request that is still pending with the resolver. * Note that a client MUST NOT cancel a request that has * been completed (i.e, the callback has been called to * signal timeout or the final result). * * @param rh handle of request to cancel */ void GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *rh) { if (rh->task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (rh->task); rh->task = GNUNET_SCHEDULER_NO_TASK; } if (rh->was_transmitted == GNUNET_NO) { if (rh->was_queued == GNUNET_YES) GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh); GNUNET_free (rh); return; } GNUNET_assert (rh->was_transmitted == GNUNET_YES); rh->was_transmitted = GNUNET_SYSERR; /* mark as cancelled */ } /* end of resolver_api.c */