2 This file is part of GNUnet.
3 (C) 2001-2013 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., 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.
30 #include "gnunet_protocols.h"
31 #include "gnunet_util_lib.h"
35 * How often do we re-try tranmsitting requests before giving up?
36 * Note that if we succeeded transmitting a request but failed to read
37 * a response, we do NOT re-try.
39 #define MAX_ATTEMPTS 50
41 #define LOG(kind,...) GNUNET_log_from (kind, "util",__VA_ARGS__)
44 * Handle for a transmission request.
46 struct GNUNET_CLIENT_TransmitHandle
51 struct GNUNET_CLIENT_Connection *client;
54 * Function to call to get the data for transmission.
56 GNUNET_CONNECTION_TransmitReadyNotify notify;
59 * Closure for @e notify.
64 * Handle to the transmission with the underlying
67 struct GNUNET_CONNECTION_TransmitHandle *th;
70 * If we are re-trying and are delaying to do so,
71 * handle to the scheduled task managing the delay.
73 GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
76 * Timeout for the operation overall.
78 struct GNUNET_TIME_Absolute timeout;
81 * Number of bytes requested.
86 * Are we allowed to re-try to connect without telling
87 * the user (of this API) about the connection troubles?
92 * Number of attempts left for transmitting the request. We may
93 * fail the first time (say because the service is not yet up), in
94 * which case (if auto_retry is set) we wait a bit and re-try
95 * (timeout permitting).
97 unsigned int attempts_left;
103 * Context for processing
104 * "GNUNET_CLIENT_transmit_and_get_response" requests.
106 struct TransmitGetResponseContext
111 struct GNUNET_CLIENT_Connection *client;
114 * Message to transmit; do not free, allocated
115 * right after this struct.
117 const struct GNUNET_MessageHeader *hdr;
122 struct GNUNET_TIME_Absolute timeout;
125 * Function to call when done.
127 GNUNET_CLIENT_MessageHandler rn;
136 * Struct to refer to a GNUnet TCP connection.
137 * This is more than just a socket because if the server
138 * drops the connection, the client automatically tries
139 * to reconnect (and for that needs connection information).
141 struct GNUNET_CLIENT_Connection
145 * The connection handle, NULL if not live
147 struct GNUNET_CONNECTION_Handle *connection;
152 const struct GNUNET_CONFIGURATION_Handle *cfg;
155 * Name of the service we interact with.
160 * Context of a transmit_and_get_response operation, NULL
161 * if no such operation is pending.
163 struct TransmitGetResponseContext *tag;
166 * Handler for current receiver task.
168 GNUNET_CLIENT_MessageHandler receiver_handler;
171 * Closure for @e receiver_handler.
173 void *receiver_handler_cls;
176 * Handle for a pending transmission request, NULL if there is
179 struct GNUNET_CLIENT_TransmitHandle *th;
182 * If we are re-trying and are delaying to do so,
183 * handle to the scheduled task managing the delay.
185 GNUNET_SCHEDULER_TaskIdentifier receive_task;
188 * Buffer for received message.
193 * Timeout for receiving a response (absolute time).
195 struct GNUNET_TIME_Absolute receive_timeout;
198 * Current value for our incremental back-off (for
201 struct GNUNET_TIME_Relative back_off;
204 * Number of bytes in received_buf that are valid.
209 * Size of received_buf.
211 unsigned int received_size;
214 * Do we have a complete response in received_buf?
219 * Are we currently busy doing receive-processing?
220 * GNUNET_YES if so, GNUNET_NO if not.
225 * Is this the first message we are sending to the service?
230 * How often have we tried to connect?
232 unsigned int attempts;
238 * Try connecting to the server using UNIX domain sockets.
240 * @param service_name name of service to connect to
241 * @param cfg configuration to use
242 * @return NULL on error, connection to UNIX otherwise
244 static struct GNUNET_CONNECTION_Handle *
245 try_unixpath (const char *service_name,
246 const struct GNUNET_CONFIGURATION_Handle *cfg)
249 struct GNUNET_CONNECTION_Handle *connection;
251 struct sockaddr_un s_un;
254 if ((GNUNET_OK == GNUNET_CONFIGURATION_get_value_filename (cfg, service_name, "UNIXPATH", &unixpath)) &&
255 (0 < strlen (unixpath)))
257 /* We have a non-NULL unixpath, need to validate it */
258 if (strlen (unixpath) >= sizeof (s_un.sun_path))
260 LOG (GNUNET_ERROR_TYPE_WARNING,
261 _("UNIXPATH `%s' too long, maximum length is %llu\n"), unixpath,
262 (unsigned long long) sizeof (s_un.sun_path));
263 unixpath = GNUNET_NETWORK_shorten_unixpath (unixpath);
264 LOG (GNUNET_ERROR_TYPE_INFO,
265 _("Using `%s' instead\n"), unixpath);
266 if (NULL == unixpath)
269 connection = GNUNET_CONNECTION_create_from_connect_to_unixpath (cfg, unixpath);
270 if (NULL != connection)
272 LOG (GNUNET_ERROR_TYPE_DEBUG, "Connected to unixpath `%s'!\n",
274 GNUNET_free (unixpath);
278 GNUNET_free_non_null (unixpath);
285 * Test whether the configuration has proper values for connection
286 * (UNIXPATH || (PORT && HOSTNAME)).
288 * @param service_name name of service to connect to
289 * @param cfg configuration to use
290 * @return #GNUNET_OK if the configuration is valid, #GNUNET_SYSERR if not
293 test_service_configuration (const char *service_name,
294 const struct GNUNET_CONFIGURATION_Handle *cfg)
296 int ret = GNUNET_SYSERR;
297 char *hostname = NULL;
298 unsigned long long port;
300 char *unixpath = NULL;
302 if ((GNUNET_OK == GNUNET_CONFIGURATION_get_value_filename (cfg, service_name, "UNIXPATH", &unixpath)) &&
303 (0 < strlen (unixpath)))
305 GNUNET_free_non_null (unixpath);
309 GNUNET_CONFIGURATION_have_value (cfg, service_name, "PORT")) &&
311 GNUNET_CONFIGURATION_get_value_number (cfg, service_name, "PORT", &port)) &&
312 (port <= 65535) && (0 != port) &&
314 GNUNET_CONFIGURATION_get_value_string (cfg, service_name, "HOSTNAME",
316 (0 != strlen (hostname)) )
318 GNUNET_free_non_null (hostname);
324 * Try to connect to the service.
326 * @param service_name name of service to connect to
327 * @param cfg configuration to use
328 * @param attempt counter used to alternate between IP and UNIX domain sockets
329 * @return NULL on error
331 static struct GNUNET_CONNECTION_Handle *
332 do_connect (const char *service_name,
333 const struct GNUNET_CONFIGURATION_Handle *cfg,
334 unsigned int attempt)
336 struct GNUNET_CONNECTION_Handle *connection;
338 unsigned long long port;
341 if (0 == (attempt % 2))
343 /* on even rounds, try UNIX first */
344 connection = try_unixpath (service_name, cfg);
345 if (NULL != connection)
349 GNUNET_CONFIGURATION_have_value (cfg, service_name, "PORT"))
352 GNUNET_CONFIGURATION_get_value_number (cfg, service_name, "PORT", &port))
355 GNUNET_CONFIGURATION_get_value_string (cfg, service_name, "HOSTNAME",
358 LOG (GNUNET_ERROR_TYPE_WARNING,
360 ("Could not determine valid hostname and port for service `%s' from configuration.\n"),
364 if (0 == strlen (hostname))
366 GNUNET_free (hostname);
367 LOG (GNUNET_ERROR_TYPE_WARNING,
368 _("Need a non-empty hostname for service `%s'.\n"), service_name);
374 /* unspecified means 0 (disabled) */
380 /* if port is 0, try UNIX */
381 connection = try_unixpath (service_name, cfg);
382 if (NULL != connection)
384 GNUNET_free_non_null (hostname);
387 LOG (GNUNET_ERROR_TYPE_DEBUG,
388 "Port is 0 for service `%s', UNIXPATH did not work, returning NULL!\n",
390 GNUNET_free_non_null (hostname);
393 connection = GNUNET_CONNECTION_create_from_connect (cfg, hostname, port);
394 GNUNET_free (hostname);
400 * Get a connection with a service.
402 * @param service_name name of the service
403 * @param cfg configuration to use
404 * @return NULL on error (service unknown to configuration)
406 struct GNUNET_CLIENT_Connection *
407 GNUNET_CLIENT_connect (const char *service_name,
408 const struct GNUNET_CONFIGURATION_Handle *cfg)
410 struct GNUNET_CLIENT_Connection *client;
411 struct GNUNET_CONNECTION_Handle *connection;
414 test_service_configuration (service_name,
417 connection = do_connect (service_name, cfg, 0);
418 client = GNUNET_new (struct GNUNET_CLIENT_Connection);
419 client->first_message = GNUNET_YES;
420 client->attempts = 1;
421 client->connection = connection;
422 client->service_name = GNUNET_strdup (service_name);
424 client->back_off = GNUNET_TIME_UNIT_MILLISECONDS;
430 * Destroy connection with the service. This will automatically
431 * cancel any pending "receive" request (however, the handler will
432 * *NOT* be called, not even with a NULL message). Any pending
433 * transmission request will also be cancelled UNLESS the callback for
434 * the transmission request has already been called, in which case the
435 * transmission 'finish_pending_write' argument determines whether or
436 * not the write is guaranteed to complete before the socket is fully
437 * destroyed (unless, of course, there is an error with the server in
438 * which case the message may still be lost).
440 * @param client handle to the service connection
443 GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *client)
445 if (GNUNET_YES == client->in_receive)
447 GNUNET_CONNECTION_receive_cancel (client->connection);
448 client->in_receive = GNUNET_NO;
450 if (NULL != client->th)
452 GNUNET_CLIENT_notify_transmit_ready_cancel (client->th);
455 if (NULL != client->connection)
457 GNUNET_CONNECTION_destroy (client->connection);
458 client->connection = NULL;
460 if (GNUNET_SCHEDULER_NO_TASK != client->receive_task)
462 GNUNET_SCHEDULER_cancel (client->receive_task);
463 client->receive_task = GNUNET_SCHEDULER_NO_TASK;
465 if (NULL != client->tag)
467 GNUNET_free (client->tag);
470 client->receiver_handler = NULL;
471 GNUNET_array_grow (client->received_buf, client->received_size, 0);
472 GNUNET_free (client->service_name);
473 GNUNET_free (client);
478 * Check if message is complete. Sets the "msg_complete" member
479 * in the client struct.
481 * @param client connection with the buffer to check
484 check_complete (struct GNUNET_CLIENT_Connection *client)
486 if ((client->received_pos >= sizeof (struct GNUNET_MessageHeader)) &&
487 (client->received_pos >=
488 ntohs (((const struct GNUNET_MessageHeader *) client->received_buf)->
490 client->msg_complete = GNUNET_YES;
495 * Callback function for data received from the network. Note that
496 * both @a available and @a errCode would be 0 if the read simply timed out.
499 * @param buf pointer to received data
500 * @param available number of bytes availabe in @a buf,
501 * possibly 0 (on errors)
502 * @param addr address of the sender
503 * @param addrlen size of @a addr
504 * @param errCode value of errno (on errors receiving)
507 receive_helper (void *cls, const void *buf, size_t available,
508 const struct sockaddr *addr, socklen_t addrlen, int errCode)
510 struct GNUNET_CLIENT_Connection *client = cls;
511 struct GNUNET_TIME_Relative remaining;
512 GNUNET_CLIENT_MessageHandler receive_handler;
513 void *receive_handler_cls;
515 GNUNET_assert (GNUNET_NO == client->msg_complete);
516 GNUNET_assert (GNUNET_YES == client->in_receive);
517 client->in_receive = GNUNET_NO;
518 if ((0 == available) || (NULL == client->connection) || (0 != errCode))
520 /* signal timeout! */
521 LOG (GNUNET_ERROR_TYPE_DEBUG,
522 "Timeout in receive_helper, available %u, client->connection %s, errCode `%s'\n",
523 (unsigned int) available, NULL == client->connection ? "NULL" : "non-NULL",
525 if (NULL != (receive_handler = client->receiver_handler))
527 receive_handler_cls = client->receiver_handler_cls;
528 client->receiver_handler = NULL;
529 receive_handler (receive_handler_cls, NULL);
533 /* FIXME: optimize for common fast case where buf contains the
534 * entire message and we need no copying... */
536 /* slow path: append to array */
537 if (client->received_size < client->received_pos + available)
538 GNUNET_array_grow (client->received_buf, client->received_size,
539 client->received_pos + available);
540 memcpy (&client->received_buf[client->received_pos], buf, available);
541 client->received_pos += available;
542 check_complete (client);
543 /* check for timeout */
544 remaining = GNUNET_TIME_absolute_get_remaining (client->receive_timeout);
545 if (0 == remaining.rel_value_us)
547 /* signal timeout! */
548 if (NULL != (receive_handler = client->receiver_handler))
550 client->receiver_handler = NULL;
551 receive_handler (client->receiver_handler_cls, NULL);
555 /* back to receive -- either for more data or to call callback! */
556 GNUNET_CLIENT_receive (client, client->receiver_handler,
557 client->receiver_handler_cls, remaining);
562 * Continuation to call the receive callback.
564 * @param cls our handle to the client connection
565 * @param tc scheduler context
568 receive_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
570 struct GNUNET_CLIENT_Connection *client = cls;
571 GNUNET_CLIENT_MessageHandler handler = client->receiver_handler;
572 const struct GNUNET_MessageHeader *cmsg =
573 (const struct GNUNET_MessageHeader *) client->received_buf;
574 void *handler_cls = client->receiver_handler_cls;
575 uint16_t msize = ntohs (cmsg->size);
576 char mbuf[msize] GNUNET_ALIGN;
577 struct GNUNET_MessageHeader *msg = (struct GNUNET_MessageHeader *) mbuf;
579 LOG (GNUNET_ERROR_TYPE_DEBUG,
580 "Received message of type %u and size %u from %s service.\n",
583 client->service_name);
584 client->receive_task = GNUNET_SCHEDULER_NO_TASK;
585 GNUNET_assert (GNUNET_YES == client->msg_complete);
586 GNUNET_assert (client->received_pos >= msize);
587 memcpy (msg, cmsg, msize);
588 memmove (client->received_buf, &client->received_buf[msize],
589 client->received_pos - msize);
590 client->received_pos -= msize;
591 client->msg_complete = GNUNET_NO;
592 client->receiver_handler = NULL;
593 check_complete (client);
595 handler (handler_cls, msg);
600 * Read from the service.
602 * @param client the service
603 * @param handler function to call with the message
604 * @param handler_cls closure for @a handler
605 * @param timeout how long to wait until timing out
608 GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *client,
609 GNUNET_CLIENT_MessageHandler handler,
611 struct GNUNET_TIME_Relative timeout)
613 if (NULL == client->connection)
615 /* already disconnected, fail instantly! */
616 GNUNET_break (0); /* this should not happen in well-written code! */
618 handler (handler_cls, NULL);
621 client->receiver_handler = handler;
622 client->receiver_handler_cls = handler_cls;
623 client->receive_timeout = GNUNET_TIME_relative_to_absolute (timeout);
624 if (GNUNET_YES == client->msg_complete)
626 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == client->receive_task);
627 client->receive_task = GNUNET_SCHEDULER_add_now (&receive_task, client);
631 LOG (GNUNET_ERROR_TYPE_DEBUG, "calling GNUNET_CONNECTION_receive\n");
632 GNUNET_assert (GNUNET_NO == client->in_receive);
633 client->in_receive = GNUNET_YES;
634 GNUNET_CONNECTION_receive (client->connection, GNUNET_SERVER_MAX_MESSAGE_SIZE - 1,
635 timeout, &receive_helper, client);
641 * Handle for a test to check if a service is running.
643 struct GNUNET_CLIENT_TestHandle
646 * Function to call with the result of the test.
648 GNUNET_CLIENT_TestResultCallback cb;
656 * Client connection we are using for the test, if any.
658 struct GNUNET_CLIENT_Connection *client;
661 * Handle for the transmission request, if any.
663 struct GNUNET_CLIENT_TransmitHandle *th;
666 * Deadline for calling @e cb.
668 struct GNUNET_TIME_Absolute test_deadline;
671 * ID of task used for asynchronous operations.
673 GNUNET_SCHEDULER_TaskIdentifier task;
676 * Final result to report back (once known).
683 * Abort testing for service.
685 * @param th test handle
688 GNUNET_CLIENT_service_test_cancel (struct GNUNET_CLIENT_TestHandle *th)
692 GNUNET_CLIENT_notify_transmit_ready_cancel (th->th);
695 if (NULL != th->client)
697 GNUNET_CLIENT_disconnect (th->client);
700 if (GNUNET_SCHEDULER_NO_TASK != th->task)
702 GNUNET_SCHEDULER_cancel (th->task);
703 th->task = GNUNET_SCHEDULER_NO_TASK;
710 * Task that reports back the result by calling the callback
711 * and then cleans up.
713 * @param cls the `struct GNUNET_CLIENT_TestHandle`
714 * @param tc scheduler context
717 report_result (void *cls,
718 const struct GNUNET_SCHEDULER_TaskContext *tc)
720 struct GNUNET_CLIENT_TestHandle *th = cls;
722 th->task = GNUNET_SCHEDULER_NO_TASK;
723 th->cb (th->cb_cls, th->result);
724 GNUNET_CLIENT_service_test_cancel (th);
729 * Report service test result asynchronously back to callback.
731 * @param th test handle with the result and the callback
732 * @param result result to report
735 service_test_report (struct GNUNET_CLIENT_TestHandle *th,
739 th->task = GNUNET_SCHEDULER_add_now (&report_result,
745 * Receive confirmation from test, service is up.
747 * @param cls closure with the `struct GNUNET_CLIENT_TestHandle`
748 * @param msg message received, NULL on timeout or fatal error
751 confirm_handler (void *cls, const struct GNUNET_MessageHeader *msg)
753 struct GNUNET_CLIENT_TestHandle *th = cls;
755 /* We may want to consider looking at the reply in more
756 * detail in the future, for example, is this the
757 * correct service? FIXME! */
760 LOG (GNUNET_ERROR_TYPE_DEBUG,
761 "Received confirmation that service is running.\n");
762 service_test_report (th, GNUNET_YES);
766 service_test_report (th, GNUNET_NO);
772 * Send the 'TEST' message to the service. If successful, prepare to
775 * @param cls the `struct GNUNET_CLIENT_TestHandle` of the test
776 * @param size number of bytes available in @a buf
777 * @param buf where to write the message
778 * @return number of bytes written to @a buf
781 write_test (void *cls, size_t size, void *buf)
783 struct GNUNET_CLIENT_TestHandle *th = cls;
784 struct GNUNET_MessageHeader *msg;
787 if (size < sizeof (struct GNUNET_MessageHeader))
789 LOG (GNUNET_ERROR_TYPE_DEBUG,
790 "Failed to transmit TEST request.\n");
791 service_test_report (th, GNUNET_NO);
792 return 0; /* client disconnected */
794 LOG (GNUNET_ERROR_TYPE_DEBUG,
795 "Transmitting `%s' request.\n",
797 msg = (struct GNUNET_MessageHeader *) buf;
798 msg->type = htons (GNUNET_MESSAGE_TYPE_TEST);
799 msg->size = htons (sizeof (struct GNUNET_MessageHeader));
800 GNUNET_CLIENT_receive (th->client,
801 &confirm_handler, th,
802 GNUNET_TIME_absolute_get_remaining
803 (th->test_deadline));
804 return sizeof (struct GNUNET_MessageHeader);
809 * Test if the service is running. If we are given a UNIXPATH or a
810 * local address, we do this NOT by trying to connect to the service,
811 * but by trying to BIND to the same port. If the BIND fails, we know
812 * the service is running.
814 * @param service name of the service to wait for
815 * @param cfg configuration to use
816 * @param timeout how long to wait at most
817 * @param cb function to call with the result
818 * @param cb_cls closure for @a cb
819 * @return handle to cancel the test
821 struct GNUNET_CLIENT_TestHandle *
822 GNUNET_CLIENT_service_test (const char *service,
823 const struct GNUNET_CONFIGURATION_Handle *cfg,
824 struct GNUNET_TIME_Relative timeout,
825 GNUNET_CLIENT_TestResultCallback cb,
828 struct GNUNET_CLIENT_TestHandle *th;
830 unsigned long long port;
831 struct GNUNET_NETWORK_Handle *sock;
833 th = GNUNET_new (struct GNUNET_CLIENT_TestHandle);
836 th->test_deadline = GNUNET_TIME_relative_to_absolute (timeout);
837 LOG (GNUNET_ERROR_TYPE_DEBUG,
838 "Testing if service `%s' is running.\n",
842 /* probe UNIX support */
843 struct sockaddr_un s_un;
849 GNUNET_CONFIGURATION_get_value_filename (cfg,
853 (0 < strlen (unixpath))) /* We have a non-NULL unixpath, does that mean it's valid? */
855 if (strlen (unixpath) >= sizeof (s_un.sun_path))
857 LOG (GNUNET_ERROR_TYPE_WARNING,
858 _("UNIXPATH `%s' too long, maximum length is %llu\n"),
860 (unsigned long long) sizeof (s_un.sun_path));
861 unixpath = GNUNET_NETWORK_shorten_unixpath (unixpath);
862 LOG (GNUNET_ERROR_TYPE_INFO,
863 _("Using `%s' instead\n"), unixpath);
867 abstract = GNUNET_CONFIGURATION_get_value_yesno (cfg,
869 "USE_ABSTRACT_SOCKETS");
871 abstract = GNUNET_NO;
873 if ((NULL != unixpath) && (GNUNET_YES != abstract))
875 if (GNUNET_SYSERR == GNUNET_DISK_directory_create_for_file (unixpath))
876 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
879 if (NULL != unixpath)
881 sock = GNUNET_NETWORK_socket_create (PF_UNIX, SOCK_STREAM, 0);
884 memset (&s_un, 0, sizeof (s_un));
885 s_un.sun_family = AF_UNIX;
886 strncpy (s_un.sun_path, unixpath, sizeof (s_un.sun_path) - 1);
887 if (GNUNET_YES == abstract)
888 s_un.sun_path[0] = '\0';
889 #if HAVE_SOCKADDR_IN_SIN_LEN
890 s_un.sun_len = (u_char) sizeof (struct sockaddr_un);
893 GNUNET_NETWORK_socket_bind (sock, (const struct sockaddr *) &s_un,
894 sizeof (struct sockaddr_un)))
896 /* failed to bind => service must be running */
897 GNUNET_free (unixpath);
898 (void) GNUNET_NETWORK_socket_close (sock);
899 service_test_report (th, GNUNET_YES);
902 (void) GNUNET_NETWORK_socket_close (sock);
906 GNUNET_free_non_null (unixpath);
912 GNUNET_CONFIGURATION_get_value_number (cfg, service, "PORT", &port)) ||
915 GNUNET_CONFIGURATION_get_value_string (cfg, service, "HOSTNAME",
918 /* UNIXPATH failed (if possible) AND IP failed => error */
919 service_test_report (th, GNUNET_SYSERR);
923 if (0 == strcmp ("localhost", hostname)
929 /* can test using 'bind' */
930 struct sockaddr_in s_in;
932 memset (&s_in, 0, sizeof (s_in));
933 #if HAVE_SOCKADDR_IN_SIN_LEN
934 s_in.sin_len = sizeof (struct sockaddr_in);
936 s_in.sin_family = AF_INET;
937 s_in.sin_port = htons (port);
939 sock = GNUNET_NETWORK_socket_create (AF_INET, SOCK_STREAM, 0);
943 GNUNET_NETWORK_socket_bind (sock, (const struct sockaddr *) &s_in,
946 /* failed to bind => service must be running */
947 GNUNET_free (hostname);
948 (void) GNUNET_NETWORK_socket_close (sock);
949 service_test_report (th, GNUNET_YES);
952 (void) GNUNET_NETWORK_socket_close (sock);
956 if (0 == strcmp ("ip6-localhost", hostname)
962 /* can test using 'bind' */
963 struct sockaddr_in6 s_in6;
965 memset (&s_in6, 0, sizeof (s_in6));
966 #if HAVE_SOCKADDR_IN_SIN_LEN
967 s_in6.sin6_len = sizeof (struct sockaddr_in6);
969 s_in6.sin6_family = AF_INET6;
970 s_in6.sin6_port = htons (port);
972 sock = GNUNET_NETWORK_socket_create (AF_INET6, SOCK_STREAM, 0);
976 GNUNET_NETWORK_socket_bind (sock, (const struct sockaddr *) &s_in6,
979 /* failed to bind => service must be running */
980 GNUNET_free (hostname);
981 (void) GNUNET_NETWORK_socket_close (sock);
982 service_test_report (th, GNUNET_YES);
985 (void) GNUNET_NETWORK_socket_close (sock);
989 if (((0 == strcmp ("localhost", hostname)) ||
990 (0 == strcmp ("ip6-localhost", hostname)))
996 /* all binds succeeded => claim service not running right now */
997 GNUNET_free_non_null (hostname);
998 service_test_report (th, GNUNET_NO);
1001 GNUNET_free_non_null (hostname);
1003 /* non-localhost, try 'connect' method */
1004 th->client = GNUNET_CLIENT_connect (service, cfg);
1005 if (NULL == th->client)
1007 LOG (GNUNET_ERROR_TYPE_INFO,
1008 _("Could not connect to service `%s', configuration broken.\n"),
1010 service_test_report (th, GNUNET_SYSERR);
1013 th->th = GNUNET_CLIENT_notify_transmit_ready (th->client,
1014 sizeof (struct GNUNET_MessageHeader),
1015 timeout, GNUNET_YES,
1019 LOG (GNUNET_ERROR_TYPE_WARNING,
1020 _("Failure to transmit request to service `%s'\n"), service);
1021 service_test_report (th, GNUNET_SYSERR);
1029 * Connection notifies us about failure or success of
1030 * a transmission request. Either pass it on to our
1031 * user or, if possible, retry.
1033 * @param cls our `struct GNUNET_CLIENT_TransmissionHandle`
1034 * @param size number of bytes available for transmission
1035 * @param buf where to write them
1036 * @return number of bytes written to buf
1039 client_notify (void *cls, size_t size, void *buf);
1043 * This task is run if we should re-try connection to the
1044 * service after a while.
1046 * @param cls our `struct GNUNET_CLIENT_TransmitHandle` of the request
1050 client_delayed_retry (void *cls,
1051 const struct GNUNET_SCHEDULER_TaskContext *tc)
1053 struct GNUNET_CLIENT_TransmitHandle *th = cls;
1054 struct GNUNET_TIME_Relative delay;
1056 th->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1057 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1059 /* give up, was shutdown */
1060 th->client->th = NULL;
1061 th->notify (th->notify_cls, 0, NULL);
1065 th->client->connection =
1066 do_connect (th->client->service_name,
1068 th->client->attempts++);
1069 th->client->first_message = GNUNET_YES;
1070 if (NULL == th->client->connection)
1072 /* could happen if we're out of sockets */
1074 GNUNET_TIME_relative_min (GNUNET_TIME_absolute_get_remaining
1075 (th->timeout), th->client->back_off);
1076 th->client->back_off =
1077 GNUNET_TIME_relative_min (GNUNET_TIME_relative_multiply
1078 (th->client->back_off, 2),
1079 GNUNET_TIME_UNIT_SECONDS);
1080 LOG (GNUNET_ERROR_TYPE_DEBUG,
1081 "Transmission failed %u times, trying again in %s.\n",
1082 MAX_ATTEMPTS - th->attempts_left,
1083 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1084 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->reconnect_task);
1085 th->reconnect_task =
1086 GNUNET_SCHEDULER_add_delayed (delay, &client_delayed_retry, th);
1090 GNUNET_CONNECTION_notify_transmit_ready (th->client->connection, th->size,
1091 GNUNET_TIME_absolute_get_remaining
1092 (th->timeout), &client_notify,
1097 th->client->th = NULL;
1098 th->notify (th->notify_cls, 0, NULL);
1106 * Connection notifies us about failure or success of a transmission
1107 * request. Either pass it on to our user or, if possible, retry.
1109 * @param cls our `struct GNUNET_CLIENT_TransmissionHandle`
1110 * @param size number of bytes available for transmission
1111 * @param buf where to write them
1112 * @return number of bytes written to @a buf
1115 client_notify (void *cls, size_t size, void *buf)
1117 struct GNUNET_CLIENT_TransmitHandle *th = cls;
1118 struct GNUNET_CLIENT_Connection *client = th->client;
1120 struct GNUNET_TIME_Relative delay;
1122 LOG (GNUNET_ERROR_TYPE_DEBUG,
1123 "client_notify is running\n");
1128 delay = GNUNET_TIME_absolute_get_remaining (th->timeout);
1129 delay.rel_value_us /= 2;
1130 if ((GNUNET_YES != th->auto_retry) || (0 == --th->attempts_left) ||
1131 (delay.rel_value_us < 1)||
1132 (0 != (GNUNET_SCHEDULER_get_reason() & GNUNET_SCHEDULER_REASON_SHUTDOWN)))
1134 LOG (GNUNET_ERROR_TYPE_DEBUG,
1135 "Transmission failed %u times, giving up.\n",
1136 MAX_ATTEMPTS - th->attempts_left);
1137 GNUNET_break (0 == th->notify (th->notify_cls, 0, NULL));
1142 LOG (GNUNET_ERROR_TYPE_DEBUG,
1143 "Failed to connect to `%s', automatically trying again.\n",
1144 client->service_name);
1145 if (GNUNET_YES == client->in_receive)
1147 GNUNET_CONNECTION_receive_cancel (client->connection);
1148 client->in_receive = GNUNET_NO;
1150 GNUNET_CONNECTION_destroy (client->connection);
1151 client->connection = NULL;
1152 delay = GNUNET_TIME_relative_min (delay, client->back_off);
1154 GNUNET_TIME_relative_min (GNUNET_TIME_relative_multiply
1155 (client->back_off, 2),
1156 GNUNET_TIME_UNIT_SECONDS);
1157 LOG (GNUNET_ERROR_TYPE_DEBUG,
1158 "Transmission failed %u times, trying again in %s.\n",
1159 MAX_ATTEMPTS - th->attempts_left,
1160 GNUNET_STRINGS_relative_time_to_string (delay, GNUNET_YES));
1162 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->reconnect_task);
1163 th->reconnect_task =
1164 GNUNET_SCHEDULER_add_delayed (delay, &client_delayed_retry, th);
1167 GNUNET_assert (size >= th->size);
1168 ret = th->notify (th->notify_cls, size, buf);
1170 if (sizeof (struct GNUNET_MessageHeader) <= ret)
1172 LOG (GNUNET_ERROR_TYPE_DEBUG,
1173 "Transmitting message of type %u and size %u to %s service.\n",
1174 ntohs (((struct GNUNET_MessageHeader *) buf)->type),
1175 ntohs (((struct GNUNET_MessageHeader *) buf)->size),
1176 client->service_name);
1183 * Ask the client to call us once the specified number of bytes
1184 * are free in the transmission buffer. May call the notify
1185 * method immediately if enough space is available.
1187 * @param client connection to the service
1188 * @param size number of bytes to send
1189 * @param timeout after how long should we give up (and call
1190 * notify with buf NULL and size 0)?
1191 * @param auto_retry if the connection to the service dies, should we
1192 * automatically re-connect and retry (within the timeout period)
1193 * or should we immediately fail in this case? Pass GNUNET_YES
1194 * if the caller does not care about temporary connection errors,
1195 * for example because the protocol is stateless
1196 * @param notify function to call
1197 * @param notify_cls closure for @a notify
1198 * @return NULL if our buffer will never hold size bytes,
1199 * a handle if the notify callback was queued (can be used to cancel)
1201 struct GNUNET_CLIENT_TransmitHandle *
1202 GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
1204 struct GNUNET_TIME_Relative timeout,
1206 GNUNET_CONNECTION_TransmitReadyNotify notify,
1209 struct GNUNET_CLIENT_TransmitHandle *th;
1211 if (NULL != client->th)
1213 /* If this breaks, you most likley called this function twice without waiting
1214 * for completion or canceling the request */
1218 th = GNUNET_new (struct GNUNET_CLIENT_TransmitHandle);
1219 th->client = client;
1221 th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1222 /* always auto-retry on first message to service */
1223 th->auto_retry = (GNUNET_YES == client->first_message) ? GNUNET_YES : auto_retry;
1224 client->first_message = GNUNET_NO;
1225 th->notify = notify;
1226 th->notify_cls = notify_cls;
1227 th->attempts_left = MAX_ATTEMPTS;
1229 if (NULL == client->connection)
1231 GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->reconnect_task);
1232 th->reconnect_task =
1233 GNUNET_SCHEDULER_add_delayed (client->back_off,
1234 &client_delayed_retry,
1241 GNUNET_CONNECTION_notify_transmit_ready (client->connection, size, timeout,
1242 &client_notify, th);
1256 * Cancel a request for notification.
1258 * @param th handle from the original request.
1261 GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle *th)
1263 if (GNUNET_SCHEDULER_NO_TASK != th->reconnect_task)
1265 GNUNET_assert (NULL == th->th);
1266 GNUNET_SCHEDULER_cancel (th->reconnect_task);
1267 th->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1271 GNUNET_assert (NULL != th->th);
1272 GNUNET_CONNECTION_notify_transmit_ready_cancel (th->th);
1274 th->client->th = NULL;
1280 * Function called to notify a client about the socket
1281 * begin ready to queue the message. @a buf will be
1282 * NULL and @a size zero if the socket was closed for
1283 * writing in the meantime.
1285 * @param cls closure of type "struct TransmitGetResponseContext*"
1286 * @param size number of bytes available in @a buf
1287 * @param buf where the callee should write the message
1288 * @return number of bytes written to @a buf
1291 transmit_for_response (void *cls,
1295 struct TransmitGetResponseContext *tc = cls;
1298 tc->client->tag = NULL;
1299 msize = ntohs (tc->hdr->size);
1302 LOG (GNUNET_ERROR_TYPE_DEBUG,
1303 _("Could not submit request, not expecting to receive a response.\n"));
1305 tc->rn (tc->rn_cls, NULL);
1309 GNUNET_assert (size >= msize);
1310 memcpy (buf, tc->hdr, msize);
1311 GNUNET_CLIENT_receive (tc->client, tc->rn, tc->rn_cls,
1312 GNUNET_TIME_absolute_get_remaining (tc->timeout));
1319 * Convenience API that combines sending a request
1320 * to the service and waiting for a response.
1321 * If either operation times out, the callback
1322 * will be called with a "NULL" response (in which
1323 * case the connection should probably be destroyed).
1325 * @param client connection to use
1326 * @param hdr message to transmit
1327 * @param timeout when to give up (for both transmission
1328 * and for waiting for a response)
1329 * @param auto_retry if the connection to the service dies, should we
1330 * automatically re-connect and retry (within the timeout period)
1331 * or should we immediately fail in this case? Pass GNUNET_YES
1332 * if the caller does not care about temporary connection errors,
1333 * for example because the protocol is stateless
1334 * @param rn function to call with the response
1335 * @param rn_cls closure for @a rn
1336 * @return #GNUNET_OK on success, #GNUNET_SYSERR if a request
1337 * is already pending
1340 GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection *client,
1341 const struct GNUNET_MessageHeader *hdr,
1342 struct GNUNET_TIME_Relative timeout,
1344 GNUNET_CLIENT_MessageHandler rn,
1347 struct TransmitGetResponseContext *tc;
1350 if (NULL != client->th)
1351 return GNUNET_SYSERR;
1352 GNUNET_assert (NULL == client->tag);
1353 msize = ntohs (hdr->size);
1354 tc = GNUNET_malloc (sizeof (struct TransmitGetResponseContext) + msize);
1355 tc->client = client;
1356 tc->hdr = (const struct GNUNET_MessageHeader *) &tc[1];
1357 memcpy (&tc[1], hdr, msize);
1358 tc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1360 tc->rn_cls = rn_cls;
1362 GNUNET_CLIENT_notify_transmit_ready (client, msize, timeout, auto_retry,
1363 &transmit_for_response, tc))
1367 return GNUNET_SYSERR;
1374 /* end of client.c */