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
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
|
/*
** Zabbix
** Copyright (C) 2001-2014 Zabbix SIA
**
** This program 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 2 of the License, or
** (at your option) any later version.
**
** This program 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 this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**/
#include "common.h"
#include "module.h"
#include "zbxmodules.h"
#include "log.h"
#include "sysinfo.h"
#define ZBX_MODULE_FUNC_INIT "zbx_module_init"
#define ZBX_MODULE_FUNC_API_VERSION "zbx_module_api_version"
#define ZBX_MODULE_FUNC_ITEM_LIST "zbx_module_item_list"
#define ZBX_MODULE_FUNC_ITEM_PROCESS "zbx_module_item_process"
#define ZBX_MODULE_FUNC_ITEM_TIMEOUT "zbx_module_item_timeout"
#define ZBX_MODULE_FUNC_UNINIT "zbx_module_uninit"
static void **modules = NULL;
/******************************************************************************
* *
* Function: register_module *
* *
* Purpose: Add module to the list of loaded modules (dynamic libraries). *
* It skips a module if it is already registered. *
* *
* Parameters: module - library handler *
* *
* Return value: SUCCEED - if module is successfully registered *
* FAIL - if module is already registered *
* *
******************************************************************************/
static int register_module(void *module)
{
const char *__function_name = "register_module";
int i = 0, ret = FAIL;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
if (NULL == modules)
{
modules = zbx_malloc(modules, sizeof(void *));
modules[0] = NULL;
}
while (NULL != modules[i])
{
if (module == modules[i]) /* a module is already registered */
goto out;
i++;
}
modules = zbx_realloc(modules, (i + 2) * sizeof(void *));
modules[i] = module;
modules[i + 1] = NULL;
ret = SUCCEED;
out:
zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%s", __function_name, zbx_result_string(ret));
return ret;
}
/******************************************************************************
* *
* Function: load_modules *
* *
* Purpose: load loadable modules (dynamic libraries) *
* It skips a module in case of any errors *
* *
* Parameters: path - directory where modules are located *
* file_names - list of module names *
* timeout - timeout in seconds for processing of items by module *
* verbose - output list of loaded modules *
* *
* Return value: SUCCEED - all modules is successfully loaded *
* FAIL - loading of modules failed *
* *
******************************************************************************/
int load_modules(const char *path, char **file_names, int timeout, int verbose)
{
const char *__function_name = "load_modules";
char **file_name, *buffer = NULL;
void *lib;
char full_name[MAX_STRING_LEN], error[MAX_STRING_LEN];
int (*func_init)(), (*func_version)();
ZBX_METRIC *(*func_list)();
void (*func_timeout)();
int i, ret = FAIL;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
for (file_name = file_names; NULL != *file_name; file_name++)
{
zbx_snprintf(full_name, sizeof(full_name), "%s/%s", path, *file_name);
zabbix_log(LOG_LEVEL_DEBUG, "loading module \"%s\"", full_name);
if (NULL == (lib = dlopen(full_name, RTLD_NOW)))
{
zabbix_log(LOG_LEVEL_CRIT, "cannot load module \"%s\": %s", *file_name, dlerror());
goto fail;
}
*(void **)(&func_version) = dlsym(lib, ZBX_MODULE_FUNC_API_VERSION);
if (NULL == func_version)
{
zabbix_log(LOG_LEVEL_CRIT, "cannot find \"" ZBX_MODULE_FUNC_API_VERSION "()\""
" function in module \"%s\": %s", *file_name, dlerror());
dlclose(lib);
goto fail;
}
if (ZBX_MODULE_API_VERSION_ONE != (i = func_version()))
{
zabbix_log(LOG_LEVEL_CRIT, "unsupported module \"%s\" version: %d", *file_name, i);
dlclose(lib);
goto fail;
}
*(void **)(&func_init) = dlsym(lib, ZBX_MODULE_FUNC_INIT);
if (NULL == func_init)
{
zabbix_log(LOG_LEVEL_CRIT, "cannot find \"" ZBX_MODULE_FUNC_INIT "()\""
" function in module \"%s\": %s", *file_name, dlerror());
dlclose(lib);
goto fail;
}
if (ZBX_MODULE_OK != func_init())
{
zabbix_log(LOG_LEVEL_CRIT, "cannot initialize module \"%s\"", *file_name);
dlclose(lib);
goto fail;
}
/* the function is optional, zabbix will load the module even if it is missing */
*(void **)(&func_timeout) = dlsym(lib, ZBX_MODULE_FUNC_ITEM_TIMEOUT);
if (NULL == func_timeout)
{
zabbix_log(LOG_LEVEL_DEBUG, "cannot find \"" ZBX_MODULE_FUNC_ITEM_TIMEOUT "()\""
" function in module \"%s\": %s", *file_name, dlerror());
}
else
func_timeout(timeout);
*(void **)(&func_list) = dlsym(lib, ZBX_MODULE_FUNC_ITEM_LIST);
if (NULL == func_list)
{
zabbix_log(LOG_LEVEL_WARNING, "cannot find \"" ZBX_MODULE_FUNC_ITEM_LIST "()\""
" function in module \"%s\": %s", *file_name, dlerror());
dlclose(lib);
continue;
}
if (SUCCEED == register_module(lib))
{
ZBX_METRIC *metrics;
metrics = func_list();
for (i = 0; NULL != metrics[i].key; i++)
{
/* accept only CF_HAVEPARAMS flag from module items */
metrics[i].flags &= CF_HAVEPARAMS;
/* the flag means that the items comes from a loadable module */
metrics[i].flags |= CF_MODULE;
if (SUCCEED != add_metric(&metrics[i], error, sizeof(error)))
{
zabbix_log(LOG_LEVEL_CRIT, "cannot load module \"%s\": %s", *file_name, error);
exit(EXIT_FAILURE);
}
}
if (1 == verbose)
{
if (NULL != buffer)
buffer = zbx_strdcat(buffer, ", ");
buffer = zbx_strdcat(buffer, *file_name);
}
}
}
if (NULL != buffer)
zabbix_log(LOG_LEVEL_WARNING, "loaded modules: %s", buffer);
ret = SUCCEED;
fail:
zbx_free(buffer);
zabbix_log(LOG_LEVEL_DEBUG, "End of %s():%s", __function_name, zbx_result_string(ret));
return ret;
}
/******************************************************************************
* *
* Function: unload_modules *
* *
* Purpose: Unload already loaded loadable modules (dynamic libraries). *
* It is called on process shutdown. *
* *
******************************************************************************/
void unload_modules()
{
const char *__function_name = "unload_modules";
int (*func_uninit)();
void **module;
zabbix_log(LOG_LEVEL_DEBUG, "In %s()", __function_name);
/* there is no registered modules */
if (NULL == modules)
return;
for (module = modules; NULL != *module; module++)
{
*(void **)(&func_uninit) = dlsym(*module, ZBX_MODULE_FUNC_UNINIT);
if (NULL == func_uninit)
{
zabbix_log(LOG_LEVEL_DEBUG, "cannot find \"" ZBX_MODULE_FUNC_UNINIT "()\" function: %s",
dlerror());
dlclose(*module);
continue;
}
if (ZBX_MODULE_OK != func_uninit())
zabbix_log(LOG_LEVEL_WARNING, "uninitialization failed");
dlclose(*module);
}
zbx_free(modules);
zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}
|
