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 "    a - Check for all available channels, not only the first one.\n"
  54 "    s - Consider the channel unavailable if the channel is in use at all.\n"
  55 "    t - Simply checks if specified channels exist in the channel list\n"
  56 "        (implies option s).\n"
  57 "This application sets the following channel variable upon completion:\n"
  58 "  AVAILCHAN     - the name of the available channel, if one exists\n"
  59 "  AVAILORIGCHAN - the canonical channel name that was used to create the channel\n"
  60 "  AVAILSTATUS   - the status code for the available channel\n";
  61
  62
  63 static int chanavail_exec(struct ast_channel *chan, void *data)
  64 {
  65         int inuse=-1, option_state=0, string_compare=0, option_all_avail=0;
  66         int status;
  67         char *info, tmp[512], trychan[512], *peers, *tech, *number, *rest, *cur;
  68         struct ast_str *tmp_availchan = ast_str_alloca(2048);
  69         struct ast_str *tmp_availorig = ast_str_alloca(2048);
  70         struct ast_str *tmp_availstat = ast_str_alloca(2048);
  71         struct ast_channel *tempchan;
  72         AST_DECLARE_APP_ARGS(args,
  73                 AST_APP_ARG(reqchans);
  74                 AST_APP_ARG(options);
  75         );
  76
  77         if (ast_strlen_zero(data)) {
  78                 ast_log(LOG_WARNING, "ChanIsAvail requires an argument (Zap/1&Zap/2)\n");
  79                 return -1;
  80         }
  81
  82         info = ast_strdupa(data);
  83
  84         AST_STANDARD_APP_ARGS(args, info);
  85
  86         if (args.options) {
  87                 if (strchr(args.options, 'a')) {
  88                         option_all_avail = 1;
  89                 }
  90                 if (strchr(args.options, 's')) {
  91                         option_state = 1;
  92                 }
  93                 if (strchr(args.options, 't')) {
  94                         string_compare = 1;
  95                 }
  96         }
  97         peers = args.reqchans;
  98         if (peers) {
  99                 cur = peers;
 100                 do {
 101                         /* remember where to start next time */
 102                         rest = strchr(cur, '&');
 103                         if (rest) {
 104                                 *rest = 0;
 105                                 rest++;
 106                         }
 107                         tech = cur;
 108                         number = strchr(tech, '/');
 109                         if (!number) {
 110                                 ast_log(LOG_WARNING, "ChanIsAvail argument takes format ([technology]/[device])\n");
 111                                 return -1;
 112                         }
 113                         *number = '\0';
 114                         number++;
 115
 116                         if (string_compare) {
 117                                 /* ast_parse_device_state checks for "SIP/1234" as a channel name.
 118                                    ast_device_state will ask the SIP driver for the channel state. */
 119
 120                                 snprintf(trychan, sizeof(trychan), "%s/%s",cur,number);
 121                                 status = inuse = ast_parse_device_state(trychan);
 122                         } else if (option_state) {
 123                                 /* If the pbx says in use then don't bother trying further.
 124                                    This is to permit testing if someone's on a call, even if the
 125                                    channel can permit more calls (ie callwaiting, sip calls, etc).  */
 126
 127                                 snprintf(trychan, sizeof(trychan), "%s/%s",cur,number);
 128                                 status = inuse = ast_device_state(trychan);
 129                         }
 130                         if ((inuse <= 1) && (tempchan = ast_request(tech, chan->nativeformats, number, &status))) {
 131                                         ast_str_append(&tmp_availchan, 0, "%s%s", tmp_availchan->used ? "&" : "", tempchan->name);
 132
 133                                         snprintf(tmp, sizeof(tmp), "%s/%s", tech, number);
 134                                         ast_str_append(&tmp_availorig, 0, "%s%s", tmp_availorig->used ? "&" : "", tmp);
 135
 136                                         snprintf(tmp, sizeof(tmp), "%d", status);
 137                                         ast_str_append(&tmp_availstat, 0, "%s%s", tmp_availstat->used ? "&" : "", tmp);
 138
 139                                         ast_hangup(tempchan);
 140                                         tempchan = NULL;
 141
 142                                         if (!option_all_avail) {
 143                                                 break;
 144                                         }
 145                         } else {
 146                                 snprintf(tmp, sizeof(tmp), "%d", status);
 147                                 ast_str_append(&tmp_availstat, 0, "%s%s", tmp_availstat->used ? "&" : "", tmp);
 148                         }
 149                         cur = rest;
 150                 } while (cur);
 151         }
 152
 153         pbx_builtin_setvar_helper(chan, "AVAILCHAN", tmp_availchan->str);
 154         /* Store the originally used channel too */
 155         pbx_builtin_setvar_helper(chan, "AVAILORIGCHAN", tmp_availorig->str);
 156         pbx_builtin_setvar_helper(chan, "AVAILSTATUS", tmp_availstat->str);
 157
 158         return 0;
 159 }
 160
 161 static int unload_module(void)
 162 {
 163         return ast_unregister_application(app);
 164 }
 165
 166 static int load_module(void)
 167 {
 168         return ast_register_application(app, chanavail_exec, synopsis, descrip) ?
 169                 AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
 170 }
 171
 172 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Check channel availability");