apps/app_system.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2005, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Execute arbitrary system commands
  22  *
  23  * \author Mark Spencer <markster@digium.com>
  24  *
  25  * \ingroup applications
  26  */
  27
  28 #include "asterisk.h"
  29
  30 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  31
  32 #include <stdlib.h>
  33 #include <stdio.h>
  34 #include <unistd.h>
  35 #include <string.h>
  36 #include <errno.h>
  37
  38 #include "asterisk/lock.h"
  39 #include "asterisk/file.h"
  40 #include "asterisk/logger.h"
  41 #include "asterisk/channel.h"
  42 #include "asterisk/pbx.h"
  43 #include "asterisk/module.h"
  44 #include "asterisk/app.h"
  45 #include "asterisk/options.h"
  46
  47 static char *app = "System";
  48
  49 static char *app2 = "TrySystem";
  50
  51 static char *synopsis = "Execute a system command";
  52
  53 static char *synopsis2 = "Try executing a system command";
  54
  55 static char *chanvar = "SYSTEMSTATUS";
  56
  57 static char *descrip =
  58 "  System(command): Executes a command  by  using  system(). If the command\n"
  59 "fails, the console should report a fallthrough. \n"
  60 "Result of execution is returned in the SYSTEMSTATUS channel variable:\n"
  61 "   FAILURE     Could not execute the specified command\n"
  62 "   SUCCESS     Specified command successfully executed\n"
  63 "\n"
  64 "Old behaviour:\n"
  65 "If the command itself executes but is in error, and if there exists\n"
  66 "a priority n + 101, where 'n' is the priority of the current instance,\n"
  67 "then  the  channel  will  be  setup to continue at that priority level.\n"
  68 "Note that this jump functionality has been deprecated and will only occur\n"
  69 "if the global priority jumping option is enabled in extensions.conf.\n";
  70
  71 static char *descrip2 =
  72 "  TrySystem(command): Executes a command  by  using  system().\n"
  73 "on any situation.\n"
  74 "Result of execution is returned in the SYSTEMSTATUS channel variable:\n"
  75 "   FAILURE     Could not execute the specified command\n"
  76 "   SUCCESS     Specified command successfully executed\n"
  77 "   APPERROR    Specified command successfully executed, but returned error code\n"
  78 "\n"
  79 "Old behaviour:\nIf  the command itself executes but is in error, and if\n"
  80 "there exists a priority n + 101, where 'n' is the priority of the current\n"
  81 "instance, then  the  channel  will  be  setup  to continue at that\n"
  82 "priority level.  Otherwise, System will terminate.\n";
  83
  84
  85 static int system_exec_helper(struct ast_channel *chan, void *data, int failmode)
  86 {
  87         int res=0;
  88         struct ast_module_user *u;
  89
  90         if (ast_strlen_zero(data)) {
  91                 ast_log(LOG_WARNING, "System requires an argument(command)\n");
  92                 pbx_builtin_setvar_helper(chan, chanvar, "FAILURE");
  93                 return failmode;
  94         }
  95
  96         u = ast_module_user_add(chan);
  97
  98         ast_autoservice_start(chan);
  99
 100         /* Do our thing here */
 101         res = ast_safe_system((char *)data);
 102         if ((res < 0) && (errno != ECHILD)) {
 103                 ast_log(LOG_WARNING, "Unable to execute '%s'\n", (char *)data);
 104                 pbx_builtin_setvar_helper(chan, chanvar, "FAILURE");
 105                 res = failmode;
 106         } else if (res == 127) {
 107                 ast_log(LOG_WARNING, "Unable to execute '%s'\n", (char *)data);
 108                 pbx_builtin_setvar_helper(chan, chanvar, "FAILURE");
 109                 res = failmode;
 110         } else {
 111                 if (res < 0)
 112                         res = 0;
 113                 if (ast_opt_priority_jumping && res)
 114                         ast_goto_if_exists(chan, chan->context, chan->exten, chan->priority + 101);
 115
 116                 if (res != 0)
 117                         pbx_builtin_setvar_helper(chan, chanvar, "APPERROR");
 118                 else
 119                         pbx_builtin_setvar_helper(chan, chanvar, "SUCCESS");
 120                 res = 0;
 121         }
 122
 123         ast_autoservice_stop(chan);
 124
 125         ast_module_user_remove(u);
 126
 127         return res;
 128 }
 129
 130 static int system_exec(struct ast_channel *chan, void *data)
 131 {
 132         return system_exec_helper(chan, data, -1);
 133 }
 134
 135 static int trysystem_exec(struct ast_channel *chan, void *data)
 136 {
 137         return system_exec_helper(chan, data, 0);
 138 }
 139
 140 static int unload_module(void)
 141 {
 142         int res;
 143
 144         res = ast_unregister_application(app);
 145         res |= ast_unregister_application(app2);
 146
 147         ast_module_user_hangup_all();
 148
 149         return res;
 150 }
 151
 152 static int load_module(void)
 153 {
 154         int res;
 155
 156         res = ast_register_application(app2, trysystem_exec, synopsis2, descrip2);
 157         res |= ast_register_application(app, system_exec, synopsis, descrip);
 158
 159         return res;
 160 }
 161
 162 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Generic System() application");