aboutsummaryrefslogtreecommitdiff
path: root/src/include/gnunet_plugin_lib.h
blob: bfcf1924fe1f1b75cccadeefdb73feac2e38b3f3 (plain) (blame)
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
/*
     This file is part of GNUnet.
     Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 GNUnet e.V.

     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     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
     Affero General Public License for more details.
    
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
*/

/**
 * @author Christian Grothoff
 *
 * @file
 * Plugin loading and unloading
 *
 * @defgroup plugin  Plugin library
 * Plugin loading and unloading
 * @{
 */

#ifndef GNUNET_PLUGIN_LIB_H
#define GNUNET_PLUGIN_LIB_H

#ifdef __cplusplus
extern "C"
{
#if 0                           /* keep Emacsens' auto-indent happy */
}
#endif
#endif

#include "gnunet_common.h"
#include "gnunet_configuration_lib.h"


/**
 * Signature of any function exported by a plugin.
 *
 * @param arg argument to the function (context)
 * @return some pointer, NULL if the plugin was
 *         shutdown or if there was an error, otherwise
 *         the plugin's API on success
 */
typedef void *
(*GNUNET_PLUGIN_Callback) (void *arg);


/**
 * Test if a plugin exists.
 *
 * Note that the library must export a symbol called
 * "library_name_init" for the test to succeed.
 *
 * @param library_name name of the plugin to test if it is installed
 * @return #GNUNET_YES if the plugin exists, #GNUNET_NO if not
 */
int
GNUNET_PLUGIN_test (const char *library_name);


/**
 * Setup plugin (runs the "init" callback and returns whatever "init"
 * returned).  If "init" returns NULL, the plugin is unloaded.
 *
 * Note that the library must export symbols called
 * "library_name_init" and "library_name_done".  These will be called
 * when the library is loaded and unloaded respectively.
 *
 * @param library_name name of the plugin to load
 * @param arg argument to the plugin initialization function
 * @return whatever the initialization function returned, NULL on error
 */
void *
GNUNET_PLUGIN_load (const char *library_name,
                    void *arg);


/**
 * Signature of a function called by #GNUNET_PLUGIN_load_all().
 *
 * @param cls closure
 * @param library_name full name of the library (to be used with
 *        #GNUNET_PLUGIN_unload)
 * @param lib_ret return value from the initialization function
 *        of the library (same as what #GNUNET_PLUGIN_load would
 *        have returned for the given library name)
 */
typedef void
(*GNUNET_PLUGIN_LoaderCallback) (void *cls,
                                 const char *library_name,
                                 void *lib_ret);


/**
 * Load all compatible plugins with the given base name.
 *
 * Note that the library must export symbols called
 * "basename_ANYTHING_init" and "basename_ANYTHING__done".  These will
 * be called when the library is loaded and unloaded respectively.
 *
 * @param basename basename of the plugins to load
 * @param arg argument to the plugin initialization function
 * @param cb function to call for each plugin found
 * @param cb_cls closure for @a cb
 */
void
GNUNET_PLUGIN_load_all (const char *basename,
                        void *arg,
                        GNUNET_PLUGIN_LoaderCallback cb,
                        void *cb_cls);


/**
 * Unload plugin (runs the "done" callback and returns whatever "done"
 * returned).  The plugin is then unloaded.
 *
 * @param library_name name of the plugin to unload
 * @param arg argument to the plugin shutdown function
 * @return whatever the shutdown function returned, typically NULL
 *         or a "char *" representing the error message
 */
void *
GNUNET_PLUGIN_unload (const char *library_name,
                      void *arg);


#if 0                           /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif

/* ifndef GNUNET_PLUGIN_LIB_H */
#endif

/** @} */  /* end of group */

/* end of gnunet_plugin_lib.h */