2 This file is part of GNUnet.
3 Copyright (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., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
22 * @author Christian Grothoff
25 * Functions related to accessing services
27 * @defgroup client Client library
28 * Generic client-side communication with services
32 #ifndef GNUNET_CLIENT_LIB_H
33 #define GNUNET_CLIENT_LIB_H
38 #if 0 /* keep Emacsens' auto-indent happy */
45 * Opaque handle for a connection to a service.
47 struct GNUNET_CLIENT_Connection;
50 * Get a connection with a service.
52 * @param service_name name of the service
53 * @param cfg configuration to use
54 * @return NULL on error (service unknown to configuration)
56 struct GNUNET_CLIENT_Connection *
57 GNUNET_CLIENT_connect (const char *service_name,
58 const struct GNUNET_CONFIGURATION_Handle *cfg);
62 * Destroy connection with the service. This will automatically
63 * cancel any pending "receive" request (however, the handler will
64 * *NOT* be called, not even with a NULL message). Any pending
65 * transmission request will also be cancelled UNLESS the callback for
66 * the transmission request has already been called, in which case the
67 * transmission 'finish_pending_write' argument determines whether or
68 * not the write is guaranteed to complete before the socket is fully
69 * destroyed (unless, of course, there is an error with the server in
70 * which case the message may still be lost).
72 * @param client handle to the service connection
75 GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *client);
79 * Type of a function to call when we receive a message
83 * @param msg message received, NULL on timeout or fatal error
85 typedef void (*GNUNET_CLIENT_MessageHandler) (void *cls,
86 const struct GNUNET_MessageHeader *msg);
90 * Read from the service.
92 * @param client connection to the service
93 * @param handler function to call with the message
94 * @param handler_cls closure for @a handler
95 * @param timeout how long to wait until timing out
98 GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *client,
99 GNUNET_CLIENT_MessageHandler handler, void *handler_cls,
100 struct GNUNET_TIME_Relative timeout);
104 * Transmit handle for client connections.
106 struct GNUNET_CLIENT_TransmitHandle;
110 * Ask the client to call us once the specified number of bytes
111 * are free in the transmission buffer. Will never call the @a notify
112 * callback in this task, but always first go into the scheduler.
114 * @param client connection to the service
115 * @param size number of bytes to send
116 * @param timeout after how long should we give up (and call
117 * @a notify with buf NULL and size 0)?
118 * @param auto_retry if the connection to the service dies, should we
119 * automatically re-connect and retry (within the timeout period)
120 * or should we immediately fail in this case? Pass #GNUNET_YES
121 * if the caller does not care about temporary connection errors,
122 * for example because the protocol is stateless
123 * @param notify function to call
124 * @param notify_cls closure for @a notify
125 * @return NULL if someone else is already waiting to be notified
126 * non-NULL if the notify callback was queued (can be used to cancel
127 * using #GNUNET_CONNECTION_notify_transmit_ready_cancel)
129 struct GNUNET_CLIENT_TransmitHandle *
130 GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
132 struct GNUNET_TIME_Relative timeout,
134 GNUNET_CONNECTION_TransmitReadyNotify notify,
139 * Cancel a request for notification.
141 * @param th handle from the original request.
144 GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle
149 * Convenience API that combines sending a request
150 * to the service and waiting for a response.
151 * If either operation times out, the callback
152 * will be called with a "NULL" response (in which
153 * case the connection should probably be destroyed).
155 * @param client connection to use
156 * @param hdr message to transmit
157 * @param timeout when to give up (for both transmission
158 * and for waiting for a response)
159 * @param auto_retry if the connection to the service dies, should we
160 * automatically re-connect and retry (within the timeout period)
161 * or should we immediately fail in this case? Pass #GNUNET_YES
162 * if the caller does not care about temporary connection errors,
163 * for example because the protocol is stateless
164 * @param rn function to call with the response
165 * @param rn_cls closure for @a rn
166 * @return #GNUNET_OK on success, #GNUNET_SYSERR if a request
170 GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection *client,
171 const struct GNUNET_MessageHeader *hdr,
172 struct GNUNET_TIME_Relative timeout,
174 GNUNET_CLIENT_MessageHandler rn,
179 * Handle for a test to check if a service is running.
181 struct GNUNET_CLIENT_TestHandle;
184 * Function called with the result on the service test.
187 * @param result #GNUNET_YES if the service is running,
188 * #GNUNET_NO if the service is not running
189 * #GNUNET_SYSERR if the configuration is invalid
191 typedef void (*GNUNET_CLIENT_TestResultCallback)(void *cls,
196 * Test if the service is running. If we are given a UNIXPATH or a
197 * local address, we do this NOT by trying to connect to the service,
198 * but by trying to BIND to the same port. If the BIND fails, we know
199 * the service is running.
201 * @param service name of the service to wait for
202 * @param cfg configuration to use
203 * @param timeout how long to wait at most
204 * @param cb function to call with the result
205 * @param cb_cls closure for @a cb
206 * @return handle to cancel the test
208 struct GNUNET_CLIENT_TestHandle *
209 GNUNET_CLIENT_service_test (const char *service,
210 const struct GNUNET_CONFIGURATION_Handle *cfg,
211 struct GNUNET_TIME_Relative timeout,
212 GNUNET_CLIENT_TestResultCallback cb, void *cb_cls);
216 * Abort testing for service.
218 * @param th test handle
221 GNUNET_CLIENT_service_test_cancel (struct GNUNET_CLIENT_TestHandle *th);
224 #if 0 /* keep Emacsens' auto-indent happy */
231 /* ifndef GNUNET_CLIENT_LIB_H */
234 /** @} */ /* end of group client */
236 /* end of gnunet_client_lib.h */