1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
/*
This file is part of GNUnet.
(C) 2001-2013 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 3, 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 include/gnunet_client_lib.h
* @brief functions related to accessing services
* @author Christian Grothoff
* @defgroup client Generic client-side communication with services
* @{
*/
#ifndef GNUNET_CLIENT_LIB_H
#define GNUNET_CLIENT_LIB_H
#ifdef __cplusplus
extern "C"
{
#if 0 /* keep Emacsens' auto-indent happy */
}
#endif
#endif
/**
* Opaque handle for a connection to a service.
*/
struct GNUNET_CLIENT_Connection;
/**
* Get a connection with a service.
*
* @param service_name name of the service
* @param cfg configuration to use
* @return NULL on error (service unknown to configuration)
*/
struct GNUNET_CLIENT_Connection *
GNUNET_CLIENT_connect (const char *service_name,
const struct GNUNET_CONFIGURATION_Handle *cfg);
/**
* Destroy connection with the service. This will automatically
* cancel any pending "receive" request (however, the handler will
* *NOT* be called, not even with a NULL message). Any pending
* transmission request will also be cancelled UNLESS the callback for
* the transmission request has already been called, in which case the
* transmission 'finish_pending_write' argument determines whether or
* not the write is guaranteed to complete before the socket is fully
* destroyed (unless, of course, there is an error with the server in
* which case the message may still be lost).
*
* @param client handle to the service connection
*/
void
GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *client);
/**
* Type of a function to call when we receive a message
* from the service.
*
* @param cls closure
* @param msg message received, NULL on timeout or fatal error
*/
typedef void (*GNUNET_CLIENT_MessageHandler) (void *cls,
const struct GNUNET_MessageHeader
*msg);
/**
* Read from the service.
*
* @param client connection to the service
* @param handler function to call with the message
* @param handler_cls closure for @a handler
* @param timeout how long to wait until timing out
*/
void
GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *client,
GNUNET_CLIENT_MessageHandler handler, void *handler_cls,
struct GNUNET_TIME_Relative timeout);
/**
* Transmit handle for client connections.
*/
struct GNUNET_CLIENT_TransmitHandle;
/**
* Ask the client to call us once the specified number of bytes
* are free in the transmission buffer. May call the notify
* method immediately if enough space is available.
*
* @param client connection to the service
* @param size number of bytes to send
* @param timeout after how long should we give up (and call
* @a notify with buf NULL and size 0)?
* @param auto_retry if the connection to the service dies, should we
* automatically re-connect and retry (within the timeout period)
* or should we immediately fail in this case? Pass #GNUNET_YES
* if the caller does not care about temporary connection errors,
* for example because the protocol is stateless
* @param notify function to call
* @param notify_cls closure for @a notify
* @return NULL if someone else is already waiting to be notified
* non-NULL if the notify callback was queued (can be used to cancel
* using #GNUNET_CONNECTION_notify_transmit_ready_cancel)
*/
struct GNUNET_CLIENT_TransmitHandle *
GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
size_t size,
struct GNUNET_TIME_Relative timeout,
int auto_retry,
GNUNET_CONNECTION_TransmitReadyNotify
notify, void *notify_cls);
/**
* Cancel a request for notification.
*
* @param th handle from the original request.
*/
void
GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle
*th);
/**
* Convenience API that combines sending a request
* to the service and waiting for a response.
* If either operation times out, the callback
* will be called with a "NULL" response (in which
* case the connection should probably be destroyed).
*
* @param client connection to use
* @param hdr message to transmit
* @param timeout when to give up (for both transmission
* and for waiting for a response)
* @param auto_retry if the connection to the service dies, should we
* automatically re-connect and retry (within the timeout period)
* or should we immediately fail in this case? Pass #GNUNET_YES
* if the caller does not care about temporary connection errors,
* for example because the protocol is stateless
* @param rn function to call with the response
* @param rn_cls closure for @a rn
* @return #GNUNET_OK on success, #GNUNET_SYSERR if a request
* is already pending
*/
int
GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection *client,
const struct GNUNET_MessageHeader *hdr,
struct GNUNET_TIME_Relative timeout,
int auto_retry,
GNUNET_CLIENT_MessageHandler rn,
void *rn_cls);
/**
* Handle for a test to check if a service is running.
*/
struct GNUNET_CLIENT_TestHandle;
/**
* Function called with the result on the service test.
*
* @param cls closure
* @param result #GNUNET_YES if the service is running,
* #GNUNET_NO if the service is not running
* #GNUNET_SYSERR if the configuration is invalid
*/
typedef void (*GNUNET_CLIENT_TestResultCallback)(void *cls,
int result);
/**
* Test if the service is running. If we are given a UNIXPATH or a
* local address, we do this NOT by trying to connect to the service,
* but by trying to BIND to the same port. If the BIND fails, we know
* the service is running.
*
* @param service name of the service to wait for
* @param cfg configuration to use
* @param timeout how long to wait at most
* @param cb function to call with the result
* @param cb_cls closure for @a cb
* @return handle to cancel the test
*/
struct GNUNET_CLIENT_TestHandle *
GNUNET_CLIENT_service_test (const char *service,
const struct GNUNET_CONFIGURATION_Handle *cfg,
struct GNUNET_TIME_Relative timeout,
GNUNET_CLIENT_TestResultCallback cb, void *cb_cls);
/**
* Abort testing for service.
*
* @param th test handle
*/
void
GNUNET_CLIENT_service_test_cancel (struct GNUNET_CLIENT_TestHandle *th);
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif
/** @} */ /* end of group client */
/* ifndef GNUNET_CLIENT_LIB_H */
#endif
/* end of gnunet_client_lib.h */
|
