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         /* Do our thing here */
  99         res = ast_safe_system((char *)data);
 100         if ((res < 0) && (errno != ECHILD)) {
 101                 ast_log(LOG_WARNING, "Unable to execute '%s'\n", (char *)data);
 102                 pbx_builtin_setvar_helper(chan, chanvar, "FAILURE");
 103                 res = failmode;
 104         } else if (res == 127) {
 105                 ast_log(LOG_WARNING, "Unable to execute '%s'\n", (char *)data);
 106                 pbx_builtin_setvar_helper(chan, chanvar, "FAILURE");
 107                 res = failmode;
 108         } else {
 109                 if (res < 0)
 110                         res = 0;
 111                 if (ast_opt_priority_jumping && res)
 112                         ast_goto_if_exists(chan, chan->context, chan->exten, chan->priority + 101);
 113
 114                 if (res != 0)
 115                         pbx_builtin_setvar_helper(chan, chanvar, "APPERROR");
 116                 else
 117                         pbx_builtin_setvar_helper(chan, chanvar, "SUCCESS");
 118                 res = 0;
 119         }
 120
 121         ast_module_user_remove(u);
 122
 123         return res;
 124 }
 125
 126 static int system_exec(struct ast_channel *chan, void *data)
 127 {
 128         return system_exec_helper(chan, data, -1);
 129 }
 130
 131 static int trysystem_exec(struct ast_channel *chan, void *data)
 132 {
 133         return system_exec_helper(chan, data, 0);
 134 }
 135
 136 static int unload_module(void)
 137 {
 138         int res;
 139
 140         res = ast_unregister_application(app);
 141         res |= ast_unregister_application(app2);
 142
 143         ast_module_user_hangup_all();
 144
 145         return res;
 146 }
 147
 148 static int load_module(void)
 149 {
 150         int res;
 151
 152         res = ast_register_application(app2, trysystem_exec, synopsis2, descrip2);
 153         res |= ast_register_application(app, system_exec, synopsis, descrip);
 154
 155         return res;
 156 }
 157
 158 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Generic System() application");