Asterisk - The Open Source Telephony Project  21.4.1
res_snmp.c
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1 /*
2  * Copyright (C) 2006 Voop as
3  * Thorsten Lockert <tholo@voop.as>
4  *
5  * This program is free software, distributed under the terms of
6  * the GNU General Public License Version 2. See the LICENSE file
7  * at the top of the source tree.
8  */
9 
10 /*! \file
11  *
12  * \brief SNMP Agent / SubAgent support for Asterisk
13  *
14  * \author Thorsten Lockert <tholo@voop.as>
15  *
16  * Uses the Net-SNMP libraries available at
17  * http://net-snmp.sourceforge.net/
18  */
19 
20 /*! \li \ref res_snmp.c uses the configuration file \ref res_snmp.conf
21  * \addtogroup configuration_file Configuration Files
22  */
23 
24 /*!
25  * \page res_snmp.conf res_snmp.conf
26  * \verbinclude res_snmp.conf.sample
27  */
28 
29 /*** MODULEINFO
30  <depend>netsnmp</depend>
31  <support_level>extended</support_level>
32  ***/
33 
34 #include "asterisk.h"
35 
36 #include "asterisk/channel.h"
37 #include "asterisk/module.h"
38 
39 #include "snmp/agent.h"
40 
41 #define MODULE_DESCRIPTION "SNMP [Sub]Agent for Asterisk"
42 
43 int res_snmp_agentx_subagent;
44 int res_snmp_dont_stop;
45 static int res_snmp_enabled;
46 
47 static pthread_t thread = AST_PTHREADT_NULL;
48 
49 /*!
50  * \brief Load res_snmp.conf config file
51  * \return 1 on load, 0 file does not exist
52 */
53 static int load_config(void)
54 {
55  struct ast_variable *var;
56  struct ast_config *cfg;
57  struct ast_flags config_flags = { 0 };
58  char *cat;
59 
60  res_snmp_enabled = 0;
61  res_snmp_agentx_subagent = 1;
62  cfg = ast_config_load("res_snmp.conf", config_flags);
63  if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEINVALID) {
64  ast_log(LOG_WARNING, "Could not load res_snmp.conf\n");
65  return 0;
66  }
67  cat = ast_category_browse(cfg, NULL);
68  while (cat) {
69  var = ast_variable_browse(cfg, cat);
70 
71  if (strcasecmp(cat, "general") == 0) {
72  while (var) {
73  if (strcasecmp(var->name, "subagent") == 0) {
74  if (ast_true(var->value))
75  res_snmp_agentx_subagent = 1;
76  else if (ast_false(var->value))
77  res_snmp_agentx_subagent = 0;
78  else {
79  ast_log(LOG_ERROR, "Value '%s' does not evaluate to true or false.\n", var->value);
80  ast_config_destroy(cfg);
81  return 1;
82  }
83  } else if (strcasecmp(var->name, "enabled") == 0) {
84  res_snmp_enabled = ast_true(var->value);
85  } else {
86  ast_log(LOG_ERROR, "Unrecognized variable '%s' in category '%s'\n", var->name, cat);
87  ast_config_destroy(cfg);
88  return 1;
89  }
90  var = var->next;
91  }
92  } else {
93  ast_log(LOG_ERROR, "Unrecognized category '%s'\n", cat);
94  ast_config_destroy(cfg);
95  return 1;
96  }
97 
98  cat = ast_category_browse(cfg, cat);
99  }
100  ast_config_destroy(cfg);
101  return 1;
102 }
103 
104 /*!
105  * \brief Load the module
106  *
107  * Module loading including tests for configuration or dependencies.
108  * This function can return AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_DECLINE,
109  * or AST_MODULE_LOAD_SUCCESS. If a dependency or environment variable fails
110  * tests return AST_MODULE_LOAD_FAILURE. If the module can not load the
111  * configuration file or other non-critical problem return
112  * AST_MODULE_LOAD_DECLINE. On success return AST_MODULE_LOAD_SUCCESS.
113  */
114 static int load_module(void)
115 {
116  if(!load_config())
118 
119  ast_verb(1, "Loading [Sub]Agent Module\n");
120 
121  res_snmp_dont_stop = 1;
122  if (res_snmp_enabled)
123  return ast_pthread_create_background(&thread, NULL, agent_thread, NULL);
124  else
125  return 0;
126 }
127 
128 static int unload_module(void)
129 {
130  ast_verb(1, "Unloading [Sub]Agent Module\n");
131 
132  res_snmp_dont_stop = 0;
133  return ((thread != AST_PTHREADT_NULL) ? pthread_join(thread, NULL) : 0);
134 }
135 
136 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "SNMP [Sub]Agent for Asterisk",
137  .support_level = AST_MODULE_SUPPORT_EXTENDED,
138  .load = load_module,
139  .unload = unload_module,
140 );
struct ast_variable * next
Asterisk main include file. File version handling, generic pbx functions.
Structure for variables, used for configurations and for channel variables.
pthread_t thread
Definition: app_sla.c:329
static int load_config(void)
Load res_snmp.conf config file.
Definition: res_snmp.c:53
char * ast_category_browse(struct ast_config *config, const char *prev_name)
Browse categories.
Definition: extconf.c:3326
#define ast_config_load(filename, flags)
Load a config file.
General Asterisk PBX channel definitions.
int attribute_pure ast_true(const char *val)
Make sure something is true. Determine if a string containing a boolean value is "true". This function checks to see whether a string passed to it is an indication of an "true" value. It checks to see if the string is "yes", "true", "y", "t", "on" or "1".
Definition: utils.c:2199
Module has failed to load, may be in an inconsistent state.
Definition: module.h:78
Structure used to handle boolean flags.
Definition: utils.h:199
SNMP Agent / SubAgent support for Asterisk.
int attribute_pure ast_false(const char *val)
Make sure something is false. Determine if a string containing a boolean value is "false"...
Definition: utils.c:2216
void ast_config_destroy(struct ast_config *cfg)
Destroys a config.
Definition: extconf.c:1289
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:46
Asterisk module definitions.
static int load_module(void)
Load the module.
Definition: res_snmp.c:114