normalize code preparing for loader changes
[asterisk/asterisk.git] / 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 <stdlib.h>
31 #include <stdio.h>
32 #include <string.h>
33 #include <unistd.h>
34 #include <errno.h>
35 #include <sys/ioctl.h>
36
37 #include "asterisk.h"
38
39 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
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 LOCAL_USER_DECL;
67
68 static int chanavail_exec(struct ast_channel *chan, void *data)
69 {
70         int res=-1, inuse=-1, option_state=0, priority_jump=0;
71         int status;
72         struct localuser *u;
73         char *info, tmp[512], trychan[512], *peers, *tech, *number, *rest, *cur;
74         struct ast_channel *tempchan;
75         AST_DECLARE_APP_ARGS(args,
76                 AST_APP_ARG(reqchans);
77                 AST_APP_ARG(options);
78         );
79
80         if (ast_strlen_zero(data)) {
81                 ast_log(LOG_WARNING, "ChanIsAvail requires an argument (Zap/1&Zap/2)\n");
82                 return -1;
83         }
84
85         LOCAL_USER_ADD(u);
86
87         info = ast_strdupa(data); 
88
89         AST_STANDARD_APP_ARGS(args, info);
90
91         if (args.options) {
92                 if (strchr(args.options, 's'))
93                         option_state = 1;
94                 if (strchr(args.options, 'j'))
95                         priority_jump = 1;
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                                 LOCAL_USER_REMOVE(u);
112                                 return -1;
113                         }
114                         *number = '\0';
115                         number++;
116                         
117                         if (option_state) {
118                                 /* If the pbx says in use then don't bother trying further.
119                                    This is to permit testing if someone's on a call, even if the 
120                                    channel can permit more calls (ie callwaiting, sip calls, etc).  */
121                                
122                                 snprintf(trychan, sizeof(trychan), "%s/%s",cur,number);
123                                 status = inuse = ast_device_state(trychan);
124                         }
125                         if ((inuse <= 1) && (tempchan = ast_request(tech, chan->nativeformats, number, &status))) {
126                                         pbx_builtin_setvar_helper(chan, "AVAILCHAN", tempchan->name);
127                                         /* Store the originally used channel too */
128                                         snprintf(tmp, sizeof(tmp), "%s/%s", tech, number);
129                                         pbx_builtin_setvar_helper(chan, "AVAILORIGCHAN", tmp);
130                                         snprintf(tmp, sizeof(tmp), "%d", status);
131                                         pbx_builtin_setvar_helper(chan, "AVAILSTATUS", tmp);
132                                         ast_hangup(tempchan);
133                                         tempchan = NULL;
134                                         res = 1;
135                                         break;
136                         } else {
137                                 snprintf(tmp, sizeof(tmp), "%d", status);
138                                 pbx_builtin_setvar_helper(chan, "AVAILSTATUS", tmp);
139                         }
140                         cur = rest;
141                 } while (cur);
142         }
143         if (res < 1) {
144                 pbx_builtin_setvar_helper(chan, "AVAILCHAN", "");
145                 pbx_builtin_setvar_helper(chan, "AVAILORIGCHAN", "");
146                 if (priority_jump || ast_opt_priority_jumping) {
147                         if (ast_goto_if_exists(chan, chan->context, chan->exten, chan->priority + 101)) {
148                                 LOCAL_USER_REMOVE(u);
149                                 return -1;
150                         }
151                 }
152         }
153
154         LOCAL_USER_REMOVE(u);
155         return 0;
156 }
157
158 int unload_module(void)
159 {
160         int res = 0;
161
162         res = ast_unregister_application(app);
163
164         STANDARD_HANGUP_LOCALUSERS;
165         
166         return res;
167 }
168
169 int load_module(void)
170 {
171         return ast_register_application(app, chanavail_exec, synopsis, descrip);
172 }
173
174 const char *description(void)
175 {
176         return "Check channel availability";
177 }
178
179 int usecount(void)
180 {
181         int res;
182         STANDARD_USECOUNT(res);
183         return res;
184 }
185
186 const char *key(void)
187 {
188         return ASTERISK_GPL_KEY;
189 }