apps/app_chanisavail.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 * James Golovich <james@gnuinter.net>
   8 *
   9 * See http://www.asterisk.org for more information about
  10 * the Asterisk project. Please do not directly contact
  11 * any of the maintainers of this project for assistance;
  12 * the project provides a web site, mailing lists and IRC
  13 * channels for your use.
  14 *
  15 * This program is free software, distributed under the terms of
  16 * the GNU General Public License Version 2. See the LICENSE file
  17 * at the top of the source tree.
  18 */
  19
  20 /*! \file
  21  *
  22  * \brief Check if Channel is Available
  23  *
  24  * \author Mark Spencer <markster@digium.com>
  25  * \author James Golovich <james@gnuinter.net>
  26
  27  * \ingroup applications
  28  */
  29
  30 #include "asterisk.h"
  31
  32 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  33
  34 #include <stdlib.h>
  35 #include <stdio.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38 #include <errno.h>
  39 #include <sys/ioctl.h>
  40
  41 #include "asterisk/lock.h"
  42 #include "asterisk/file.h"
  43 #include "asterisk/logger.h"
  44 #include "asterisk/channel.h"
  45 #include "asterisk/pbx.h"
  46 #include "asterisk/module.h"
  47 #include "asterisk/app.h"
  48 #include "asterisk/devicestate.h"
  49 #include "asterisk/options.h"
  50
  51 static char *app = "ChanIsAvail";
  52
  53 static char *synopsis = "Check channel availability";
  54
  55 static char *descrip =
  56 "  ChanIsAvail(Technology/resource[&Technology2/resource2...][|options]): \n"
  57 "This application will check to see if any of the specified channels are\n"
  58 "available. The following variables will be set by this application:\n"
  59 "  ${AVAILCHAN}     - the name of the available channel, if one exists\n"
  60 "  ${AVAILORIGCHAN} - the canonical channel name that was used to create the channel\n"
  61 "  ${AVAILSTATUS}   - the status code for the available channel\n"
  62 "  Options:\n"
  63 "    s - Consider the channel unavailable if the channel is in use at all\n"
  64 "    j - Support jumping to priority n+101 if no channel is available\n";
  65
  66
  67 static int chanavail_exec(struct ast_channel *chan, void *data)
  68 {
  69         int res=-1, inuse=-1, option_state=0, priority_jump=0;
  70         int status;
  71         struct ast_module_user *u;
  72         char *info, tmp[512], trychan[512], *peers, *tech, *number, *rest, *cur;
  73         struct ast_channel *tempchan;
  74         AST_DECLARE_APP_ARGS(args,
  75                 AST_APP_ARG(reqchans);
  76                 AST_APP_ARG(options);
  77         );
  78
  79         if (ast_strlen_zero(data)) {
  80                 ast_log(LOG_WARNING, "ChanIsAvail requires an argument (Zap/1&Zap/2)\n");
  81                 return -1;
  82         }
  83
  84         u = ast_module_user_add(chan);
  85
  86         info = ast_strdupa(data);
  87
  88         AST_STANDARD_APP_ARGS(args, info);
  89
  90         if (args.options) {
  91                 if (strchr(args.options, 's'))
  92                         option_state = 1;
  93                 if (strchr(args.options, 'j'))
  94                         priority_jump = 1;
  95         }
  96         peers = args.reqchans;
  97         if (peers) {
  98                 cur = peers;
  99                 do {
 100                         /* remember where to start next time */
 101                         rest = strchr(cur, '&');
 102                         if (rest) {
 103                                 *rest = 0;
 104                                 rest++;
 105                         }
 106                         tech = cur;
 107                         number = strchr(tech, '/');
 108                         if (!number) {
 109                                 ast_log(LOG_WARNING, "ChanIsAvail argument takes format ([technology]/[device])\n");
 110                                 ast_module_user_remove(u);
 111                                 return -1;
 112                         }
 113                         *number = '\0';
 114                         number++;
 115
 116                         if (option_state) {
 117                                 /* If the pbx says in use then don't bother trying further.
 118                                    This is to permit testing if someone's on a call, even if the
 119                                    channel can permit more calls (ie callwaiting, sip calls, etc).  */
 120
 121                                 snprintf(trychan, sizeof(trychan), "%s/%s",cur,number);
 122                                 status = inuse = ast_device_state(trychan);
 123                         }
 124                         if ((inuse <= 1) && (tempchan = ast_request(tech, chan->nativeformats, number, &status))) {
 125                                         pbx_builtin_setvar_helper(chan, "AVAILCHAN", tempchan->name);
 126                                         /* Store the originally used channel too */
 127                                         snprintf(tmp, sizeof(tmp), "%s/%s", tech, number);
 128                                         pbx_builtin_setvar_helper(chan, "AVAILORIGCHAN", tmp);
 129                                         snprintf(tmp, sizeof(tmp), "%d", status);
 130                                         pbx_builtin_setvar_helper(chan, "AVAILSTATUS", tmp);
 131                                         ast_hangup(tempchan);
 132                                         tempchan = NULL;
 133                                         res = 1;
 134                                         break;
 135                         } else {
 136                                 snprintf(tmp, sizeof(tmp), "%d", status);
 137                                 pbx_builtin_setvar_helper(chan, "AVAILSTATUS", tmp);
 138                         }
 139                         cur = rest;
 140                 } while (cur);
 141         }
 142         if (res < 1) {
 143                 pbx_builtin_setvar_helper(chan, "AVAILCHAN", "");
 144                 pbx_builtin_setvar_helper(chan, "AVAILORIGCHAN", "");
 145                 if (priority_jump || ast_opt_priority_jumping) {
 146                         if (ast_goto_if_exists(chan, chan->context, chan->exten, chan->priority + 101)) {
 147                                 ast_module_user_remove(u);
 148                                 return -1;
 149                         }
 150                 }
 151         }
 152
 153         ast_module_user_remove(u);
 154         return 0;
 155 }
 156
 157 static int unload_module(void)
 158 {
 159         int res = 0;
 160
 161         res = ast_unregister_application(app);
 162
 163         ast_module_user_hangup_all();
 164
 165         return res;
 166 }
 167
 168 static int load_module(void)
 169 {
 170         return ast_register_application(app, chanavail_exec, synopsis, descrip);
 171 }
 172
 173 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Check channel availability");