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 <sys/ioctl.h>
  35
  36 #include "asterisk/lock.h"
  37 #include "asterisk/file.h"
  38 #include "asterisk/channel.h"
  39 #include "asterisk/pbx.h"
  40 #include "asterisk/module.h"
  41 #include "asterisk/app.h"
  42 #include "asterisk/devicestate.h"
  43
  44 static char *app = "ChanIsAvail";
  45
  46 static char *synopsis = "Check channel availability";
  47
  48 static char *descrip =
  49 "  ChanIsAvail(Technology/resource[&Technology2/resource2...][,options]): \n"
  50 "This application will check to see if any of the specified channels are\n"
  51 "available.\n"
  52 "  Options:\n"
  53 "    s - Consider the channel unavailable if the channel is in use at all.\n"
  54 "    t - Simply checks if specified channels exist in the channel list\n"
  55 "        (implies option s).\n"
  56 "This application sets the following channel variable upon completion:\n"
  57 "  AVAILCHAN     - the name of the available channel, if one exists\n"
  58 "  AVAILORIGCHAN - the canonical channel name that was used to create the channel\n"
  59 "  AVAILSTATUS   - the status code for the available channel\n";
  60
  61
  62 static int chanavail_exec(struct ast_channel *chan, void *data)
  63 {
  64         int res=-1, inuse=-1, option_state=0, string_compare=0;
  65         int status;
  66         char *info, tmp[512], trychan[512], *peers, *tech, *number, *rest, *cur;
  67         struct ast_channel *tempchan;
  68         AST_DECLARE_APP_ARGS(args,
  69                 AST_APP_ARG(reqchans);
  70                 AST_APP_ARG(options);
  71         );
  72
  73         if (ast_strlen_zero(data)) {
  74                 ast_log(LOG_WARNING, "ChanIsAvail requires an argument (Zap/1&Zap/2)\n");
  75                 return -1;
  76         }
  77
  78         info = ast_strdupa(data);
  79
  80         AST_STANDARD_APP_ARGS(args, info);
  81
  82         if (args.options) {
  83                 if (strchr(args.options, 's'))
  84                         option_state = 1;
  85                 if (strchr(args.options, 't'))
  86                         string_compare = 1;
  87         }
  88         peers = args.reqchans;
  89         if (peers) {
  90                 cur = peers;
  91                 do {
  92                         /* remember where to start next time */
  93                         rest = strchr(cur, '&');
  94                         if (rest) {
  95                                 *rest = 0;
  96                                 rest++;
  97                         }
  98                         tech = cur;
  99                         number = strchr(tech, '/');
 100                         if (!number) {
 101                                 ast_log(LOG_WARNING, "ChanIsAvail argument takes format ([technology]/[device])\n");
 102                                 return -1;
 103                         }
 104                         *number = '\0';
 105                         number++;
 106
 107                         if (string_compare) {
 108                                 /* ast_parse_device_state checks for "SIP/1234" as a channel name.
 109                                    ast_device_state will ask the SIP driver for the channel state. */
 110
 111                                 snprintf(trychan, sizeof(trychan), "%s/%s",cur,number);
 112                                 status = inuse = ast_parse_device_state(trychan);
 113                         } else if (option_state) {
 114                                 /* If the pbx says in use then don't bother trying further.
 115                                    This is to permit testing if someone's on a call, even if the
 116                                    channel can permit more calls (ie callwaiting, sip calls, etc).  */
 117
 118                                 snprintf(trychan, sizeof(trychan), "%s/%s",cur,number);
 119                                 status = inuse = ast_device_state(trychan);
 120                         }
 121                         if ((inuse <= 1) && (tempchan = ast_request(tech, chan->nativeformats, number, &status))) {
 122                                         pbx_builtin_setvar_helper(chan, "AVAILCHAN", tempchan->name);
 123                                         /* Store the originally used channel too */
 124                                         snprintf(tmp, sizeof(tmp), "%s/%s", tech, number);
 125                                         pbx_builtin_setvar_helper(chan, "AVAILORIGCHAN", tmp);
 126                                         snprintf(tmp, sizeof(tmp), "%d", status);
 127                                         pbx_builtin_setvar_helper(chan, "AVAILSTATUS", tmp);
 128                                         ast_hangup(tempchan);
 129                                         tempchan = NULL;
 130                                         res = 1;
 131                                         break;
 132                         } else {
 133                                 snprintf(tmp, sizeof(tmp), "%d", status);
 134                                 pbx_builtin_setvar_helper(chan, "AVAILSTATUS", tmp);
 135                         }
 136                         cur = rest;
 137                 } while (cur);
 138         }
 139         if (res < 1) {
 140                 pbx_builtin_setvar_helper(chan, "AVAILCHAN", "");
 141                 pbx_builtin_setvar_helper(chan, "AVAILORIGCHAN", "");
 142         }
 143
 144         return 0;
 145 }
 146
 147 static int unload_module(void)
 148 {
 149         return ast_unregister_application(app);
 150 }
 151
 152 static int load_module(void)
 153 {
 154         return ast_register_application(app, chanavail_exec, synopsis, descrip);
 155 }
 156
 157 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Check channel availability");