2 This file is part of GNUnet.
3 (C) 2001, 2002, 2006, 2008, 2009 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
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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.
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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.
23 * @brief code for access to services
24 * @author Christian Grothoff
26 * Generic TCP code for reliable, record-oriented TCP
27 * connections between clients and service providers.
31 #include "gnunet_common.h"
32 #include "gnunet_client_lib.h"
33 #include "gnunet_protocols.h"
34 #include "gnunet_server_lib.h"
35 #include "gnunet_scheduler_lib.h"
37 #define DEBUG_CLIENT GNUNET_NO
40 * How often do we re-try tranmsitting requests before giving up?
41 * Note that if we succeeded transmitting a request but failed to read
42 * a response, we do NOT re-try.
44 #define MAX_ATTEMPTS 50
48 * Handle for a transmission request.
50 struct GNUNET_CLIENT_TransmitHandle
55 struct GNUNET_CLIENT_Connection *sock;
58 * Function to call to get the data for transmission.
60 GNUNET_CONNECTION_TransmitReadyNotify notify;
68 * Handle to the transmission with the underlying
71 struct GNUNET_CONNECTION_TransmitHandle *th;
74 * If we are re-trying and are delaying to do so,
75 * handle to the scheduled task managing the delay.
77 GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
80 * Timeout for the operation overall.
82 struct GNUNET_TIME_Absolute timeout;
85 * Number of bytes requested.
90 * Are we allowed to re-try to connect without telling
91 * the user (of this API) about the connection troubles?
96 * Number of attempts left for transmitting the request. We may
97 * fail the first time (say because the service is not yet up), in
98 * which case (if auto_retry is set) we wait a bit and re-try
99 * (timeout permitting).
101 unsigned int attempts_left;
107 * Context for processing
108 * "GNUNET_CLIENT_transmit_and_get_response" requests.
110 struct TransmitGetResponseContext
115 struct GNUNET_CLIENT_Connection *sock;
118 * Message to transmit; do not free, allocated
119 * right after this struct.
121 const struct GNUNET_MessageHeader *hdr;
126 struct GNUNET_TIME_Absolute timeout;
129 * Function to call when done.
131 GNUNET_CLIENT_MessageHandler rn;
140 * Struct to refer to a GNUnet TCP connection.
141 * This is more than just a socket because if the server
142 * drops the connection, the client automatically tries
143 * to reconnect (and for that needs connection information).
145 struct GNUNET_CLIENT_Connection
149 * the socket handle, NULL if not live
151 struct GNUNET_CONNECTION_Handle *sock;
155 * FIXME: why do we DUP the configuration? Avoid this!
157 struct GNUNET_CONFIGURATION_Handle *cfg;
160 * Name of the service we interact with.
165 * Context of a transmit_and_get_response operation, NULL
166 * if no such operation is pending.
168 struct TransmitGetResponseContext *tag;
171 * Handler for current receiver task.
173 GNUNET_CLIENT_MessageHandler receiver_handler;
176 * Closure for receiver_handler.
178 void *receiver_handler_cls;
181 * Handle for a pending transmission request, NULL if there is
184 struct GNUNET_CLIENT_TransmitHandle *th;
187 * Handler for service test completion (NULL unless in service_test)
189 GNUNET_SCHEDULER_Task test_cb;
192 * Deadline for calling 'test_cb'.
194 struct GNUNET_TIME_Absolute test_deadline;
197 * If we are re-trying and are delaying to do so,
198 * handle to the scheduled task managing the delay.
200 GNUNET_SCHEDULER_TaskIdentifier receive_task;
203 * Closure for test_cb (NULL unless in service_test)
208 * Buffer for received message.
213 * Timeout for receiving a response (absolute time).
215 struct GNUNET_TIME_Absolute receive_timeout;
218 * Current value for our incremental back-off (for
221 struct GNUNET_TIME_Relative back_off;
224 * Number of bytes in received_buf that are valid.
229 * Size of received_buf.
231 unsigned int received_size;
234 * Do we have a complete response in received_buf?
239 * Are we currently busy doing receive-processing?
240 * GNUNET_YES if so, GNUNET_NO if not.
245 * Are we ignoring shutdown signals?
250 * How often have we tried to connect?
252 unsigned int attempts;
258 * Try to connect to the service.
260 * @param service_name name of service to connect to
261 * @param cfg configuration to use
262 * @param attempt counter used to alternate between IP and UNIX domain sockets
263 * @return NULL on error
265 static struct GNUNET_CONNECTION_Handle *
266 do_connect (const char *service_name,
267 const struct GNUNET_CONFIGURATION_Handle *cfg,
268 unsigned int attempt)
270 struct GNUNET_CONNECTION_Handle *sock;
273 unsigned long long port;
276 if (0 == (attempt % 2))
278 /* on even rounds, try UNIX */
280 GNUNET_CONFIGURATION_get_value_string (cfg,
282 "UNIXPATH", &unixpath))
284 sock = GNUNET_CONNECTION_create_from_connect_to_unixpath (cfg,
286 GNUNET_free (unixpath);
294 GNUNET_CONFIGURATION_get_value_number (cfg,
300 GNUNET_CONFIGURATION_get_value_string (cfg,
302 "HOSTNAME", &hostname)))
304 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
306 ("Could not determine valid hostname and port for service `%s' from configuration.\n"),
310 if (0 == strlen (hostname))
312 GNUNET_free (hostname);
313 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
314 _("Need a non-empty hostname for service `%s'.\n"),
321 if (0 != (attempt % 2))
325 GNUNET_CONFIGURATION_get_value_string (cfg,
327 "UNIXPATH", &unixpath))
329 sock = GNUNET_CONNECTION_create_from_connect_to_unixpath (cfg,
331 GNUNET_free (unixpath);
339 sock = GNUNET_CONNECTION_create_from_connect (cfg,
342 GNUNET_free (hostname);
348 * Get a connection with a service.
350 * @param service_name name of the service
351 * @param cfg configuration to use
352 * @return NULL on error (service unknown to configuration)
354 struct GNUNET_CLIENT_Connection *
355 GNUNET_CLIENT_connect (const char *service_name,
356 const struct GNUNET_CONFIGURATION_Handle *cfg)
358 struct GNUNET_CLIENT_Connection *ret;
359 struct GNUNET_CONNECTION_Handle *sock;
361 sock = do_connect (service_name,
365 ret = GNUNET_malloc (sizeof (struct GNUNET_CLIENT_Connection));
368 ret->service_name = GNUNET_strdup (service_name);
369 ret->cfg = GNUNET_CONFIGURATION_dup (cfg);
370 ret->back_off = GNUNET_TIME_UNIT_MILLISECONDS;
376 * Configure this connection to ignore shutdown signals.
378 * @param h client handle
379 * @param do_ignore GNUNET_YES to ignore, GNUNET_NO to restore default
382 GNUNET_CLIENT_ignore_shutdown (struct GNUNET_CLIENT_Connection *h,
385 h->ignore_shutdown = do_ignore;
387 GNUNET_CONNECTION_ignore_shutdown (h->sock,
393 * Destroy connection with the service. This will automatically
394 * cancel any pending "receive" request (however, the handler will
395 * *NOT* be called, not even with a NULL message). Any pending
396 * transmission request will also be cancelled UNLESS the callback for
397 * the transmission request has already been called, in which case the
398 * transmission 'finish_pending_write' argument determines whether or
399 * not the write is guaranteed to complete before the socket is fully
400 * destroyed (unless, of course, there is an error with the server in
401 * which case the message may still be lost).
403 * @param finish_pending_write should a transmission already passed to the
404 * handle be completed?
405 * @param sock handle to the service connection
408 GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *sock,
409 int finish_pending_write)
411 GNUNET_assert (sock->sock != NULL);
412 if (sock->in_receive == GNUNET_YES)
414 GNUNET_CONNECTION_receive_cancel (sock->sock);
415 sock->in_receive = GNUNET_NO;
417 GNUNET_CONNECTION_destroy (sock->sock, finish_pending_write);
419 if (sock->tag != NULL)
421 GNUNET_free (sock->tag);
424 sock->receiver_handler = NULL;
425 if (sock->th != NULL)
426 GNUNET_CLIENT_notify_transmit_ready_cancel (sock->th);
427 if (sock->receive_task != GNUNET_SCHEDULER_NO_TASK)
429 GNUNET_SCHEDULER_cancel (sock->receive_task);
430 sock->receive_task = GNUNET_SCHEDULER_NO_TASK;
432 GNUNET_array_grow (sock->received_buf, sock->received_size, 0);
433 GNUNET_free (sock->service_name);
434 GNUNET_CONFIGURATION_destroy (sock->cfg);
440 * Check if message is complete
443 check_complete (struct GNUNET_CLIENT_Connection *conn)
445 if ((conn->received_pos >= sizeof (struct GNUNET_MessageHeader)) &&
446 (conn->received_pos >=
447 ntohs (((const struct GNUNET_MessageHeader *) conn->received_buf)->
449 conn->msg_complete = GNUNET_YES;
454 * Callback function for data received from the network. Note that
455 * both "available" and "errCode" would be 0 if the read simply timed out.
458 * @param buf pointer to received data
459 * @param available number of bytes availabe in "buf",
460 * possibly 0 (on errors)
461 * @param addr address of the sender
462 * @param addrlen size of addr
463 * @param errCode value of errno (on errors receiving)
466 receive_helper (void *cls,
469 const struct sockaddr *addr, socklen_t addrlen, int errCode)
471 struct GNUNET_CLIENT_Connection *conn = cls;
472 struct GNUNET_TIME_Relative remaining;
473 GNUNET_CLIENT_MessageHandler receive_handler;
474 void *receive_handler_cls;
476 GNUNET_assert (conn->msg_complete == GNUNET_NO);
477 conn->in_receive = GNUNET_NO;
478 if ((available == 0) || (conn->sock == NULL) || (errCode != 0))
480 /* signal timeout! */
481 if (NULL != (receive_handler = conn->receiver_handler))
483 receive_handler_cls = conn->receiver_handler_cls;
484 conn->receiver_handler = NULL;
485 receive_handler (receive_handler_cls, NULL);
490 /* FIXME: optimize for common fast case where buf contains the
491 entire message and we need no copying... */
494 /* slow path: append to array */
495 if (conn->received_size < conn->received_pos + available)
496 GNUNET_array_grow (conn->received_buf,
497 conn->received_size, conn->received_pos + available);
498 memcpy (&conn->received_buf[conn->received_pos], buf, available);
499 conn->received_pos += available;
500 check_complete (conn);
501 /* check for timeout */
502 remaining = GNUNET_TIME_absolute_get_remaining (conn->receive_timeout);
503 if (remaining.rel_value == 0)
505 /* signal timeout! */
506 conn->receiver_handler (conn->receiver_handler_cls, NULL);
509 /* back to receive -- either for more data or to call callback! */
510 GNUNET_CLIENT_receive (conn,
511 conn->receiver_handler,
512 conn->receiver_handler_cls, remaining);
517 * Continuation to call the receive callback.
519 * @param cls our handle to the client connection
520 * @param tc scheduler context
523 receive_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
525 struct GNUNET_CLIENT_Connection *sock = cls;
526 GNUNET_CLIENT_MessageHandler handler = sock->receiver_handler;
527 const struct GNUNET_MessageHeader *cmsg =
528 (const struct GNUNET_MessageHeader *) sock->received_buf;
529 void *handler_cls = sock->receiver_handler_cls;
530 uint16_t msize = ntohs (cmsg->size);
532 struct GNUNET_MessageHeader *msg = (struct GNUNET_MessageHeader *) mbuf;
535 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
536 "Received message of type %u and size %u\n",
540 sock->receive_task = GNUNET_SCHEDULER_NO_TASK;
541 GNUNET_assert (GNUNET_YES == sock->msg_complete);
542 GNUNET_assert (sock->received_pos >= msize);
543 memcpy (msg, cmsg, msize);
544 memmove (sock->received_buf,
545 &sock->received_buf[msize], sock->received_pos - msize);
546 sock->received_pos -= msize;
547 sock->msg_complete = GNUNET_NO;
548 sock->receiver_handler = NULL;
549 check_complete (sock);
551 handler (handler_cls, msg);
556 * Read from the service.
558 * @param sock the service
559 * @param handler function to call with the message
560 * @param handler_cls closure for handler
561 * @param timeout how long to wait until timing out
564 GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *sock,
565 GNUNET_CLIENT_MessageHandler handler,
566 void *handler_cls, struct GNUNET_TIME_Relative timeout)
568 if (sock->sock == NULL)
570 /* already disconnected, fail instantly! */
571 GNUNET_break (0); /* this should not happen in well-written code! */
572 handler (handler_cls, NULL);
575 sock->receiver_handler = handler;
576 sock->receiver_handler_cls = handler_cls;
577 sock->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout);
578 if (GNUNET_YES == sock->msg_complete)
580 sock->receive_task = GNUNET_SCHEDULER_add_after (GNUNET_SCHEDULER_NO_TASK,
581 &receive_task, sock);
585 GNUNET_assert (sock->in_receive == GNUNET_NO);
586 sock->in_receive = GNUNET_YES;
587 GNUNET_CONNECTION_receive (sock->sock,
588 GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
589 timeout, &receive_helper, sock);
595 * Report service unavailable.
598 service_test_error (GNUNET_SCHEDULER_Task task, void *task_cls)
600 GNUNET_SCHEDULER_add_continuation (task,
602 GNUNET_SCHEDULER_REASON_TIMEOUT);
607 * Receive confirmation from test, service is up.
610 * @param msg message received, NULL on timeout or fatal error
613 confirm_handler (void *cls, const struct GNUNET_MessageHeader *msg)
615 struct GNUNET_CLIENT_Connection *conn = cls;
616 /* We may want to consider looking at the reply in more
617 detail in the future, for example, is this the
618 correct service? FIXME! */
622 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
623 "Received confirmation that service is running.\n");
625 GNUNET_SCHEDULER_add_continuation (conn->test_cb,
627 GNUNET_SCHEDULER_REASON_PREREQ_DONE);
631 service_test_error (conn->test_cb, conn->test_cb_cls);
633 GNUNET_CLIENT_disconnect (conn, GNUNET_NO);
638 write_test (void *cls, size_t size, void *buf)
640 struct GNUNET_CLIENT_Connection *conn = cls;
641 struct GNUNET_MessageHeader *msg;
643 if (size < sizeof (struct GNUNET_MessageHeader))
646 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
647 _("Failure to transmit TEST request.\n"));
649 service_test_error (conn->test_cb, conn->test_cb_cls);
650 GNUNET_CLIENT_disconnect (conn, GNUNET_NO);
651 return 0; /* client disconnected */
654 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
655 "Transmitting `%s' request.\n", "TEST");
657 msg = (struct GNUNET_MessageHeader *) buf;
658 msg->type = htons (GNUNET_MESSAGE_TYPE_TEST);
659 msg->size = htons (sizeof (struct GNUNET_MessageHeader));
660 GNUNET_CLIENT_receive (conn,
663 GNUNET_TIME_absolute_get_remaining (conn->test_deadline));
664 return sizeof (struct GNUNET_MessageHeader);
669 * Wait until the service is running.
671 * @param service name of the service to wait for
672 * @param cfg configuration to use
673 * @param timeout how long to wait at most in ms
674 * @param task task to run if service is running
675 * (reason will be "PREREQ_DONE" (service running)
676 * or "TIMEOUT" (service not known to be running))
677 * @param task_cls closure for task
680 GNUNET_CLIENT_service_test (const char *service,
681 const struct GNUNET_CONFIGURATION_Handle *cfg,
682 struct GNUNET_TIME_Relative timeout,
683 GNUNET_SCHEDULER_Task task, void *task_cls)
685 struct GNUNET_CLIENT_Connection *conn;
688 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
689 "Testing if service `%s' is running.\n", service);
691 conn = GNUNET_CLIENT_connect (service, cfg);
694 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
696 ("Could not connect to service `%s', must not be running.\n"),
698 service_test_error (task, task_cls);
701 conn->test_cb = task;
702 conn->test_cb_cls = task_cls;
703 conn->test_deadline = GNUNET_TIME_relative_to_absolute (timeout);
705 if (NULL == GNUNET_CLIENT_notify_transmit_ready (conn,
706 sizeof (struct GNUNET_MessageHeader),
711 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
712 _("Failure to transmit request to service `%s'\n"),
714 service_test_error (task, task_cls);
715 GNUNET_CLIENT_disconnect (conn, GNUNET_NO);
722 * Connection notifies us about failure or success of
723 * a transmission request. Either pass it on to our
724 * user or, if possible, retry.
726 * @param cls our "struct GNUNET_CLIENT_TransmissionHandle"
727 * @param size number of bytes available for transmission
728 * @param buf where to write them
729 * @return number of bytes written to buf
731 static size_t client_notify (void *cls, size_t size, void *buf);
735 * This task is run if we should re-try connection to the
736 * service after a while.
738 * @param cls our "struct GNUNET_CLIENT_TransmitHandle" of the request
742 client_delayed_retry (void *cls,
743 const struct GNUNET_SCHEDULER_TaskContext *tc)
745 struct GNUNET_CLIENT_TransmitHandle *th = cls;
747 th->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
748 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
751 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
752 "Transmission failed due to shutdown.\n");
755 th->notify (th->notify_cls, 0, NULL);
759 th->th = GNUNET_CONNECTION_notify_transmit_ready (th->sock->sock,
761 GNUNET_TIME_absolute_get_remaining
767 th->notify (th->notify_cls, 0, NULL);
775 * Connection notifies us about failure or success of a transmission
776 * request. Either pass it on to our user or, if possible, retry.
778 * @param cls our "struct GNUNET_CLIENT_TransmissionHandle"
779 * @param size number of bytes available for transmission
780 * @param buf where to write them
781 * @return number of bytes written to buf
784 client_notify (void *cls, size_t size, void *buf)
786 struct GNUNET_CLIENT_TransmitHandle *th = cls;
788 struct GNUNET_TIME_Relative delay;
794 delay = GNUNET_TIME_absolute_get_remaining (th->timeout);
795 delay.rel_value /= 2;
796 if ( (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & GNUNET_SCHEDULER_get_reason ())) ||
797 (GNUNET_YES != th->auto_retry) ||
798 (0 == --th->attempts_left) ||
799 (delay.rel_value < 1) )
802 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
803 "Transmission failed %u times, giving up.\n",
804 MAX_ATTEMPTS - th->attempts_left);
806 GNUNET_break (0 == th->notify (th->notify_cls, 0, NULL));
811 GNUNET_CONNECTION_destroy (th->sock->sock, GNUNET_NO);
812 th->sock->sock = do_connect (th->sock->service_name,
814 th->sock->attempts++);
815 GNUNET_assert (NULL != th->sock->sock);
816 GNUNET_CONNECTION_ignore_shutdown (th->sock->sock,
817 th->sock->ignore_shutdown);
818 delay = GNUNET_TIME_relative_min (delay, th->sock->back_off);
820 = GNUNET_TIME_relative_min (GNUNET_TIME_relative_multiply (th->sock->back_off, 2),
821 GNUNET_TIME_UNIT_SECONDS);
823 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
824 "Transmission failed %u times, trying again in %llums.\n",
825 MAX_ATTEMPTS - th->attempts_left,
826 (unsigned long long) delay.rel_value);
828 th->reconnect_task = GNUNET_SCHEDULER_add_delayed (delay,
829 &client_delayed_retry,
834 GNUNET_assert (size >= th->size);
835 ret = th->notify (th->notify_cls, size, buf);
842 * Ask the client to call us once the specified number of bytes
843 * are free in the transmission buffer. May call the notify
844 * method immediately if enough space is available.
846 * @param sock connection to the service
847 * @param size number of bytes to send
848 * @param timeout after how long should we give up (and call
849 * notify with buf NULL and size 0)?
850 * @param auto_retry if the connection to the service dies, should we
851 * automatically re-connect and retry (within the timeout period)
852 * or should we immediately fail in this case? Pass GNUNET_YES
853 * if the caller does not care about temporary connection errors,
854 * for example because the protocol is stateless
855 * @param notify function to call
856 * @param notify_cls closure for notify
857 * @return NULL if our buffer will never hold size bytes,
858 * a handle if the notify callback was queued (can be used to cancel)
860 struct GNUNET_CLIENT_TransmitHandle *
861 GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *sock,
863 struct GNUNET_TIME_Relative timeout,
865 GNUNET_CONNECTION_TransmitReadyNotify
866 notify, void *notify_cls)
868 struct GNUNET_CLIENT_TransmitHandle *th;
870 if (NULL != sock->th)
872 th = GNUNET_malloc (sizeof (struct GNUNET_CLIENT_TransmitHandle));
875 th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
876 th->auto_retry = auto_retry;
878 th->notify_cls = notify_cls;
879 th->attempts_left = MAX_ATTEMPTS;
880 th->th = GNUNET_CONNECTION_notify_transmit_ready (sock->sock,
896 * Cancel a request for notification.
898 * @param th handle from the original request.
901 GNUNET_CLIENT_notify_transmit_ready_cancel (struct
902 GNUNET_CLIENT_TransmitHandle *th)
904 if (th->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
906 GNUNET_break (NULL == th->th);
907 GNUNET_SCHEDULER_cancel (th->reconnect_task);
908 th->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
912 GNUNET_assert (NULL != th->th);
913 GNUNET_CONNECTION_notify_transmit_ready_cancel (th->th);
921 * Function called to notify a client about the socket
922 * begin ready to queue the message. "buf" will be
923 * NULL and "size" zero if the socket was closed for
924 * writing in the meantime.
926 * @param cls closure of type "struct TransmitGetResponseContext*"
927 * @param size number of bytes available in buf
928 * @param buf where the callee should write the message
929 * @return number of bytes written to buf
932 transmit_for_response (void *cls, size_t size, void *buf)
934 struct TransmitGetResponseContext *tc = cls;
937 tc->sock->tag = NULL;
938 msize = ntohs (tc->hdr->size);
942 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
943 _("Could not submit request, not expecting to receive a response.\n"));
945 tc->rn (tc->rn_cls, NULL);
949 GNUNET_assert (size >= msize);
950 memcpy (buf, tc->hdr, msize);
951 GNUNET_CLIENT_receive (tc->sock,
954 GNUNET_TIME_absolute_get_remaining (tc->timeout));
961 * Convenience API that combines sending a request
962 * to the service and waiting for a response.
963 * If either operation times out, the callback
964 * will be called with a "NULL" response (in which
965 * case the connection should probably be destroyed).
967 * @param sock connection to use
968 * @param hdr message to transmit
969 * @param timeout when to give up (for both transmission
970 * and for waiting for a response)
971 * @param auto_retry if the connection to the service dies, should we
972 * automatically re-connect and retry (within the timeout period)
973 * or should we immediately fail in this case? Pass GNUNET_YES
974 * if the caller does not care about temporary connection errors,
975 * for example because the protocol is stateless
976 * @param rn function to call with the response
977 * @param rn_cls closure for rn
978 * @return GNUNET_OK on success, GNUNET_SYSERR if a request
982 GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection
984 const struct GNUNET_MessageHeader
986 struct GNUNET_TIME_Relative timeout,
988 GNUNET_CLIENT_MessageHandler rn,
991 struct TransmitGetResponseContext *tc;
994 if (NULL != sock->th)
995 return GNUNET_SYSERR;
996 GNUNET_assert (sock->tag == NULL);
997 msize = ntohs (hdr->size);
998 tc = GNUNET_malloc (sizeof (struct TransmitGetResponseContext) + msize);
1000 tc->hdr = (const struct GNUNET_MessageHeader *) &tc[1];
1001 memcpy (&tc[1], hdr, msize);
1002 tc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1004 tc->rn_cls = rn_cls;
1005 if (NULL == GNUNET_CLIENT_notify_transmit_ready (sock,
1009 &transmit_for_response,
1014 return GNUNET_SYSERR;
1022 /* end of client.c */