814960ac233ed32495df9f2b4cf9fe72c8b9ce21
[asterisk/asterisk.git] / funcs / func_channel.c
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 2006, Digium, Inc.
5  *
6  * See http://www.asterisk.org for more information about
7  * the Asterisk project. Please do not directly contact
8  * any of the maintainers of this project for assistance;
9  * the project provides a web site, mailing lists and IRC
10  * channels for your use.
11  *
12  * This program is free software, distributed under the terms of
13  * the GNU General Public License Version 2. See the LICENSE file
14  * at the top of the source tree.
15  */
16
17 /*! \file
18  *
19  * \brief Channel info dialplan functions
20  *
21  * \author Kevin P. Fleming <kpfleming@digium.com>
22  * \author Ben Winslow
23  *
24  * \ingroup functions
25  */
26
27 /*** MODULEINFO
28         <support_level>core</support_level>
29  ***/
30
31 #include "asterisk.h"
32
33 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
34
35 #include <regex.h>
36 #include <ctype.h>
37
38 #include "asterisk/module.h"
39 #include "asterisk/channel.h"
40 #include "asterisk/bridge.h"
41 #include "asterisk/pbx.h"
42 #include "asterisk/utils.h"
43 #include "asterisk/app.h"
44 #include "asterisk/indications.h"
45 #include "asterisk/stringfields.h"
46 #include "asterisk/global_datastores.h"
47 #include "asterisk/bridge_basic.h"
48 #include "asterisk/bridge_after.h"
49
50 /*** DOCUMENTATION
51         <function name="CHANNELS" language="en_US">
52                 <synopsis>
53                         Gets the list of channels, optionally filtering by a regular expression.
54                 </synopsis>
55                 <syntax>
56                         <parameter name="regular_expression" />
57                 </syntax>
58                 <description>
59                         <para>Gets the list of channels, optionally filtering by a <replaceable>regular_expression</replaceable>. If
60                         no argument is provided, all known channels are returned. The
61                         <replaceable>regular_expression</replaceable> must correspond to
62                         the POSIX.2 specification, as shown in <emphasis>regex(7)</emphasis>. The list returned
63                         will be space-delimited.</para>
64                 </description>
65         </function>
66         <function name="MASTER_CHANNEL" language="en_US">
67                 <synopsis>
68                         Gets or sets variables on the master channel
69                 </synopsis>
70                 <description>
71                         <para>Allows access to the channel which created the current channel, if any.  If the channel is already
72                         a master channel, then accesses local channel variables.</para>
73                 </description>
74         </function>
75         <function name="CHANNEL" language="en_US">
76                 <synopsis>
77                         Gets/sets various pieces of information about the channel.
78                 </synopsis>
79                 <syntax>
80                         <parameter name="item" required="true">
81                                 <para>Standard items (provided by all channel technologies) are:</para>
82                                 <enumlist>
83                                         <enum name="amaflags">
84                                                 <para>R/W the Automatic Message Accounting (AMA) flags on the channel.
85                                                 When read from a channel, the integer value will always be returned.
86                                                 When written to a channel, both the string format or integer value
87                                                 is accepted.</para>
88                                                 <enumlist>
89                                                         <enum name="1"><para><literal>OMIT</literal></para></enum>
90                                                         <enum name="2"><para><literal>BILLING</literal></para></enum>
91                                                         <enum name="3"><para><literal>DOCUMENTATION</literal></para></enum>
92                                                 </enumlist>
93                                         </enum>
94                                         <enum name="accountcode">
95                                                 <para>R/W the channel's account code.</para>
96                                         </enum>
97                                         <enum name="audioreadformat">
98                                                 <para>R/O format currently being read.</para>
99                                         </enum>
100                                         <enum name="audionativeformat">
101                                                 <para>R/O format used natively for audio.</para>
102                                         </enum>
103                                         <enum name="audiowriteformat">
104                                                 <para>R/O format currently being written.</para>
105                                         </enum>
106                                         <enum name="dtmf_features">
107                                                 <para>R/W The channel's DTMF bridge features.
108                                                 May include one or more of 'T' 'K' 'H' 'W' and 'X' in a similar manner to options
109                                                 in the <literal>Dial</literal> application. When setting it, the features string
110                                                 must be all upper case.</para>
111                                         </enum>
112                                         <enum name="callgroup">
113                                                 <para>R/W numeric call pickup groups that this channel is a member.</para>
114                                         </enum>
115                                         <enum name="pickupgroup">
116                                                 <para>R/W numeric call pickup groups this channel can pickup.</para>
117                                         </enum>
118                                         <enum name="namedcallgroup">
119                                                 <para>R/W named call pickup groups that this channel is a member.</para>
120                                         </enum>
121                                         <enum name="namedpickupgroup">
122                                                 <para>R/W named call pickup groups this channel can pickup.</para>
123                                         </enum>
124                                         <enum name="channeltype">
125                                                 <para>R/O technology used for channel.</para>
126                                         </enum>
127                                         <enum name="checkhangup">
128                                                 <para>R/O Whether the channel is hanging up (1/0)</para>
129                                         </enum>
130                                         <enum name="after_bridge_goto">
131                                                 <para>R/W the parseable goto string indicating where the channel is
132                                                 expected to return to in the PBX after exiting the next bridge it joins
133                                                 on the condition that it doesn't hang up. The parseable goto string uses
134                                                 the same syntax as the <literal>Goto</literal> application.</para>
135                                         </enum>
136                                         <enum name="hangup_handler_pop">
137                                                 <para>W/O Replace the most recently added hangup handler
138                                                 with a new hangup handler on the channel if supplied.  The
139                                                 assigned string is passed to the Gosub application when
140                                                 the channel is hung up.  Any optionally omitted context
141                                                 and exten are supplied by the channel pushing the handler
142                                                 before it is pushed.</para>
143                                         </enum>
144                                         <enum name="hangup_handler_push">
145                                                 <para>W/O Push a hangup handler onto the channel hangup
146                                                 handler stack.  The assigned string is passed to the
147                                                 Gosub application when the channel is hung up.  Any
148                                                 optionally omitted context and exten are supplied by the
149                                                 channel pushing the handler before it is pushed.</para>
150                                         </enum>
151                                         <enum name="hangup_handler_wipe">
152                                                 <para>W/O Wipe the entire hangup handler stack and replace
153                                                 with a new hangup handler on the channel if supplied.  The
154                                                 assigned string is passed to the Gosub application when
155                                                 the channel is hung up.  Any optionally omitted context
156                                                 and exten are supplied by the channel pushing the handler
157                                                 before it is pushed.</para>
158                                         </enum>
159                                         <enum name="language">
160                                                 <para>R/W language for sounds played.</para>
161                                         </enum>
162                                         <enum name="musicclass">
163                                                 <para>R/W class (from musiconhold.conf) for hold music.</para>
164                                         </enum>
165                                         <enum name="name">
166                                                 <para>The name of the channel</para>
167                                         </enum>
168                                         <enum name="parkinglot">
169                                                 <para>R/W parkinglot for parking.</para>
170                                         </enum>
171                                         <enum name="rxgain">
172                                                 <para>R/W set rxgain level on channel drivers that support it.</para>
173                                         </enum>
174                                         <enum name="secure_bridge_signaling">
175                                                 <para>Whether or not channels bridged to this channel require secure signaling</para>
176                                         </enum>
177                                         <enum name="secure_bridge_media">
178                                                 <para>Whether or not channels bridged to this channel require secure media</para>
179                                         </enum>
180                                         <enum name="state">
181                                                 <para>R/O state for channel</para>
182                                         </enum>
183                                         <enum name="tonezone">
184                                                 <para>R/W zone for indications played</para>
185                                         </enum>
186                                         <enum name="transfercapability">
187                                                 <para>R/W ISDN Transfer Capability, one of:</para>
188                                                 <enumlist>
189                                                         <enum name="SPEECH" />
190                                                         <enum name="DIGITAL" />
191                                                         <enum name="RESTRICTED_DIGITAL" />
192                                                         <enum name="3K1AUDIO" />
193                                                         <enum name="DIGITAL_W_TONES" />
194                                                         <enum name="VIDEO" />
195                                                 </enumlist>
196                                         </enum>
197                                         <enum name="txgain">
198                                                 <para>R/W set txgain level on channel drivers that support it.</para>
199                                         </enum>
200                                         <enum name="videonativeformat">
201                                                 <para>R/O format used natively for video</para>
202                                         </enum>
203                                         <enum name="trace">
204                                                 <para>R/W whether or not context tracing is enabled, only available
205                                                 <emphasis>if CHANNEL_TRACE is defined</emphasis>.</para>
206                                         </enum>
207                                 </enumlist>
208                                 <para><emphasis>chan_sip</emphasis> provides the following additional options:</para>
209                                 <enumlist>
210                                         <enum name="peerip">
211                                                 <para>R/O Get the IP address of the peer.</para>
212                                         </enum>
213                                         <enum name="recvip">
214                                                 <para>R/O Get the source IP address of the peer.</para>
215                                         </enum>
216                                         <enum name="recvport">
217                                                 <para>R/O Get the source port of the peer.</para>
218                                         </enum>
219                                         <enum name="from">
220                                                 <para>R/O Get the URI from the From: header.</para>
221                                         </enum>
222                                         <enum name="uri">
223                                                 <para>R/O Get the URI from the Contact: header.</para>
224                                         </enum>
225                                         <enum name="useragent">
226                                                 <para>R/O Get the useragent.</para>
227                                         </enum>
228                                         <enum name="peername">
229                                                 <para>R/O Get the name of the peer.</para>
230                                         </enum>
231                                         <enum name="t38passthrough">
232                                                 <para>R/O <literal>1</literal> if T38 is offered or enabled in this channel,
233                                                 otherwise <literal>0</literal></para>
234                                         </enum>
235                                         <enum name="rtpqos">
236                                                 <para>R/O Get QOS information about the RTP stream</para>
237                                                 <para>    This option takes two additional arguments:</para>
238                                                 <para>    Argument 1:</para>
239                                                 <para>     <literal>audio</literal>             Get data about the audio stream</para>
240                                                 <para>     <literal>video</literal>             Get data about the video stream</para>
241                                                 <para>     <literal>text</literal>              Get data about the text stream</para>
242                                                 <para>    Argument 2:</para>
243                                                 <para>     <literal>local_ssrc</literal>        Local SSRC (stream ID)</para>
244                                                 <para>     <literal>local_lostpackets</literal> Local lost packets</para>
245                                                 <para>     <literal>local_jitter</literal>      Local calculated jitter</para>
246                                                 <para>     <literal>local_maxjitter</literal>   Local calculated jitter (maximum)</para>
247                                                 <para>     <literal>local_minjitter</literal>   Local calculated jitter (minimum)</para>
248                                                 <para>     <literal>local_normdevjitter</literal>Local calculated jitter (normal deviation)</para>
249                                                 <para>     <literal>local_stdevjitter</literal> Local calculated jitter (standard deviation)</para>
250                                                 <para>     <literal>local_count</literal>       Number of received packets</para>
251                                                 <para>     <literal>remote_ssrc</literal>       Remote SSRC (stream ID)</para>
252                                                 <para>     <literal>remote_lostpackets</literal>Remote lost packets</para>
253                                                 <para>     <literal>remote_jitter</literal>     Remote reported jitter</para>
254                                                 <para>     <literal>remote_maxjitter</literal>  Remote calculated jitter (maximum)</para>
255                                                 <para>     <literal>remote_minjitter</literal>  Remote calculated jitter (minimum)</para>
256                                                 <para>     <literal>remote_normdevjitter</literal>Remote calculated jitter (normal deviation)</para>
257                                                 <para>     <literal>remote_stdevjitter</literal>Remote calculated jitter (standard deviation)</para>
258                                                 <para>     <literal>remote_count</literal>      Number of transmitted packets</para>
259                                                 <para>     <literal>rtt</literal>               Round trip time</para>
260                                                 <para>     <literal>maxrtt</literal>            Round trip time (maximum)</para>
261                                                 <para>     <literal>minrtt</literal>            Round trip time (minimum)</para>
262                                                 <para>     <literal>normdevrtt</literal>        Round trip time (normal deviation)</para>
263                                                 <para>     <literal>stdevrtt</literal>          Round trip time (standard deviation)</para>
264                                                 <para>     <literal>all</literal>               All statistics (in a form suited to logging,
265                                                 but not for parsing)</para>
266                                         </enum>
267                                         <enum name="rtpdest">
268                                                 <para>R/O Get remote RTP destination information.</para>
269                                                 <para>   This option takes one additional argument:</para>
270                                                 <para>    Argument 1:</para>
271                                                 <para>     <literal>audio</literal>             Get audio destination</para>
272                                                 <para>     <literal>video</literal>             Get video destination</para>
273                                                 <para>     <literal>text</literal>              Get text destination</para>
274                                                 <para>   Defaults to <literal>audio</literal> if unspecified.</para>
275                                         </enum>
276                                         <enum name="rtpsource">
277                                                 <para>R/O Get source RTP destination information.</para>
278                                                 <para>   This option takes one additional argument:</para>
279                                                 <para>    Argument 1:</para>
280                                                 <para>     <literal>audio</literal>             Get audio destination</para>
281                                                 <para>     <literal>video</literal>             Get video destination</para>
282                                                 <para>     <literal>text</literal>              Get text destination</para>
283                                                 <para>   Defaults to <literal>audio</literal> if unspecified.</para>
284                                         </enum>
285                                 </enumlist>
286                                 <xi:include xpointer="xpointer(/docs/info[@name='PJSIPCHANNEL'])" />
287                                 <para><emphasis>chan_iax2</emphasis> provides the following additional options:</para>
288                                 <enumlist>
289                                         <enum name="osptoken">
290                                                 <para>R/O Get the peer's osptoken.</para>
291                                         </enum>
292                                         <enum name="peerip">
293                                                 <para>R/O Get the peer's ip address.</para>
294                                         </enum>
295                                         <enum name="peername">
296                                                 <para>R/O Get the peer's username.</para>
297                                         </enum>
298                                         <enum name="secure_signaling">
299                                                 <para>R/O Get the if the IAX channel is secured.</para>
300                                         </enum>
301                                         <enum name="secure_media">
302                                                 <para>R/O Get the if the IAX channel is secured.</para>
303                                         </enum>
304                                 </enumlist>
305                                 <para><emphasis>chan_dahdi</emphasis> provides the following additional options:</para>
306                                 <enumlist>
307                                         <enum name="dahdi_channel">
308                                                 <para>R/O DAHDI channel related to this channel.</para>
309                                         </enum>
310                                         <enum name="dahdi_span">
311                                                 <para>R/O DAHDI span related to this channel.</para>
312                                         </enum>
313                                         <enum name="dahdi_type">
314                                                 <para>R/O DAHDI channel type, one of:</para>
315                                                 <enumlist>
316                                                         <enum name="analog" />
317                                                         <enum name="mfc/r2" />
318                                                         <enum name="pri" />
319                                                         <enum name="pseudo" />
320                                                         <enum name="ss7" />
321                                                 </enumlist>
322                                         </enum>
323                                         <enum name="keypad_digits">
324                                                 <para>R/O PRI Keypad digits that came in with the SETUP message.</para>
325                                         </enum>
326                                         <enum name="reversecharge">
327                                                 <para>R/O PRI Reverse Charging Indication, one of:</para>
328                                                 <enumlist>
329                                                         <enum name="-1"> <para>None</para></enum>
330                                                         <enum name=" 1"> <para>Reverse Charging Requested</para></enum>
331                                                 </enumlist>
332                                         </enum>
333                                         <enum name="no_media_path">
334                                                 <para>R/O PRI Nonzero if the channel has no B channel.
335                                                 The channel is either on hold or a call waiting call.</para>
336                                         </enum>
337                                         <enum name="buffers">
338                                                 <para>W/O Change the channel's buffer policy (for the current call only)</para>
339                                                 <para>This option takes two arguments:</para>
340                                                 <para>  Number of buffers,</para>
341                                                 <para>  Buffer policy being one of:</para>
342                                                 <para>      <literal>full</literal></para>
343                                                 <para>      <literal>immediate</literal></para>
344                                                 <para>      <literal>half</literal></para>
345                                         </enum>
346                                         <enum name="echocan_mode">
347                                                 <para>W/O Change the configuration of the active echo
348                                                 canceller on the channel (if any), for the current call
349                                                 only.</para>
350                                                 <para>Possible values are:</para>
351                                                 <para>  <literal>on</literal>   Normal mode (the echo canceller is actually reinitalized)</para>
352                                                 <para>  <literal>off</literal>  Disabled</para>
353                                                 <para>  <literal>fax</literal>  FAX/data mode (NLP disabled if possible, otherwise
354                                                         completely disabled)</para>
355                                                 <para>  <literal>voice</literal>        Voice mode (returns from FAX mode, reverting the changes that were made)</para>
356                                         </enum>
357                                 </enumlist>
358                                 <para><emphasis>chan_ooh323</emphasis> provides the following additional options:</para>
359                                 <enumlist>
360                                         <enum name="faxdetect">
361                                                 <para>R/W Fax Detect</para>
362                                                 <para>Returns 0 or 1</para>
363                                                 <para>Write yes or no</para>
364                                         </enum>
365                                         <enum name="t38support">
366                                                 <para>R/W t38support</para>
367                                                 <para>Returns 0 or 1</para>
368                                                 <para>Write yes or no</para>
369                                         </enum>
370                                         <enum name="h323id_url">
371                                                 <para>R/0 Returns caller URL</para>
372                                         </enum>
373                                         <enum name="caller_h323id">
374                                                 <para>R/0 Returns caller h323id</para>
375                                         </enum>
376                                         <enum name="caller_dialeddigits">
377                                                 <para>R/0 Returns caller dialed digits</para>
378                                         </enum>
379                                         <enum name="caller_email">
380                                                 <para>R/0 Returns caller email</para>
381                                         </enum>
382                                         <enum name="callee_email">
383                                                 <para>R/0 Returns callee email</para>
384                                         </enum>
385                                         <enum name="callee_dialeddigits">
386                                                 <para>R/0 Returns callee dialed digits</para>
387                                         </enum>
388                                         <enum name="caller_url">
389                                                 <para>R/0 Returns caller URL</para>
390                                         </enum>
391                                 </enumlist>
392                         </parameter>
393                 </syntax>
394                 <description>
395                         <para>Gets/sets various pieces of information about the channel, additional <replaceable>item</replaceable> may
396                         be available from the channel driver; see its documentation for details. Any <replaceable>item</replaceable>
397                         requested that is not available on the current channel will return an empty string.</para>
398                 </description>
399         </function>
400  ***/
401
402 #define locked_copy_string(chan, dest, source, len) \
403         do { \
404                 ast_channel_lock(chan); \
405                 ast_copy_string(dest, source, len); \
406                 ast_channel_unlock(chan); \
407         } while (0)
408 #define locked_string_field_set(chan, field, source) \
409         do { \
410                 ast_channel_lock(chan); \
411                 ast_channel_##field##_set(chan, source); \
412                 ast_channel_unlock(chan); \
413         } while (0)
414
415 static const char * const transfercapability_table[0x20] = {
416         "SPEECH", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK",
417         "DIGITAL", "RESTRICTED_DIGITAL", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK",
418         "3K1AUDIO", "DIGITAL_W_TONES", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK",
419         "VIDEO", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK", };
420
421 static int func_channel_read(struct ast_channel *chan, const char *function,
422                              char *data, char *buf, size_t len)
423 {
424         int ret = 0;
425         struct ast_format_cap *tmpcap;
426
427         if (!chan) {
428                 ast_log(LOG_WARNING, "No channel was provided to %s function.\n", function);
429                 return -1;
430         }
431
432         if (!strcasecmp(data, "audionativeformat")) {
433                 tmpcap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
434                 if (tmpcap) {
435                         struct ast_str *codec_buf = ast_str_alloca(64);
436
437                         ast_format_cap_append_from_cap(tmpcap, ast_channel_nativeformats(chan), AST_MEDIA_TYPE_AUDIO);
438                         ast_copy_string(buf, ast_format_cap_get_names(tmpcap, &codec_buf), len);
439                         ao2_ref(tmpcap, -1);
440                 }
441         } else if (!strcasecmp(data, "videonativeformat")) {
442                 tmpcap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
443                 if (tmpcap) {
444                         struct ast_str *codec_buf = ast_str_alloca(64);
445
446                         ast_format_cap_append_from_cap(tmpcap, ast_channel_nativeformats(chan), AST_MEDIA_TYPE_VIDEO);
447                         ast_copy_string(buf, ast_format_cap_get_names(tmpcap, &codec_buf), len);
448                         ao2_ref(tmpcap, -1);
449                 }
450         } else if (!strcasecmp(data, "audioreadformat")) {
451                 ast_copy_string(buf, ast_format_get_name(ast_channel_readformat(chan)), len);
452         } else if (!strcasecmp(data, "audiowriteformat")) {
453                 ast_copy_string(buf, ast_format_get_name(ast_channel_writeformat(chan)), len);
454 #ifdef CHANNEL_TRACE
455         } else if (!strcasecmp(data, "trace")) {
456                 ast_channel_lock(chan);
457                 ast_copy_string(buf, ast_channel_trace_is_enabled(chan) ? "1" : "0", len);
458                 ast_channel_unlock(chan);
459 #endif
460         } else if (!strcasecmp(data, "tonezone") && ast_channel_zone(chan)) {
461                 locked_copy_string(chan, buf, ast_channel_zone(chan)->country, len);
462         } else if (!strcasecmp(data, "dtmf_features")) {
463                 if (ast_bridge_features_ds_get_string(chan, buf, len)) {
464                         buf[0] = '\0';
465                 }
466         } else if (!strcasecmp(data, "language"))
467                 locked_copy_string(chan, buf, ast_channel_language(chan), len);
468         else if (!strcasecmp(data, "musicclass"))
469                 locked_copy_string(chan, buf, ast_channel_musicclass(chan), len);
470         else if (!strcasecmp(data, "name")) {
471                 locked_copy_string(chan, buf, ast_channel_name(chan), len);
472         } else if (!strcasecmp(data, "parkinglot"))
473                 locked_copy_string(chan, buf, ast_channel_parkinglot(chan), len);
474         else if (!strcasecmp(data, "state"))
475                 locked_copy_string(chan, buf, ast_state2str(ast_channel_state(chan)), len);
476         else if (!strcasecmp(data, "channeltype"))
477                 locked_copy_string(chan, buf, ast_channel_tech(chan)->type, len);
478         else if (!strcasecmp(data, "accountcode"))
479                 locked_copy_string(chan, buf, ast_channel_accountcode(chan), len);
480         else if (!strcasecmp(data, "checkhangup")) {
481                 ast_channel_lock(chan);
482                 ast_copy_string(buf, ast_check_hangup(chan) ? "1" : "0", len);
483                 ast_channel_unlock(chan);
484         } else if (!strcasecmp(data, "peeraccount"))
485                 locked_copy_string(chan, buf, ast_channel_peeraccount(chan), len);
486         else if (!strcasecmp(data, "hangupsource"))
487                 locked_copy_string(chan, buf, ast_channel_hangupsource(chan), len);
488         else if (!strcasecmp(data, "appname") && ast_channel_appl(chan))
489                 locked_copy_string(chan, buf, ast_channel_appl(chan), len);
490         else if (!strcasecmp(data, "appdata") && ast_channel_data(chan))
491                 locked_copy_string(chan, buf, ast_channel_data(chan), len);
492         else if (!strcasecmp(data, "exten") && ast_channel_data(chan))
493                 locked_copy_string(chan, buf, ast_channel_exten(chan), len);
494         else if (!strcasecmp(data, "context") && ast_channel_data(chan))
495                 locked_copy_string(chan, buf, ast_channel_context(chan), len);
496         else if (!strcasecmp(data, "userfield") && ast_channel_data(chan))
497                 locked_copy_string(chan, buf, ast_channel_userfield(chan), len);
498         else if (!strcasecmp(data, "channame") && ast_channel_data(chan))
499                 locked_copy_string(chan, buf, ast_channel_name(chan), len);
500         else if (!strcasecmp(data, "linkedid")) {
501                 ast_channel_lock(chan);
502                 if (ast_strlen_zero(ast_channel_linkedid(chan))) {
503                         /* fall back on the channel's uniqueid if linkedid is unset */
504                         ast_copy_string(buf, ast_channel_uniqueid(chan), len);
505                 }
506                 else {
507                         ast_copy_string(buf, ast_channel_linkedid(chan), len);
508                 }
509                 ast_channel_unlock(chan);
510         } else if (!strcasecmp(data, "peer")) {
511                 RAII_VAR(struct ast_channel *, p, NULL, ast_channel_cleanup);
512
513                 ast_channel_lock(chan);
514                 p = ast_channel_bridge_peer(chan);
515                 if (p || ast_channel_tech(chan)) /* dummy channel? if so, we hid the peer name in the language */
516                         ast_copy_string(buf, (p ? ast_channel_name(p) : ""), len);
517                 else {
518                         /* a dummy channel can still pass along bridged peer info via
519                            the BRIDGEPEER variable */
520                         const char *pname = pbx_builtin_getvar_helper(chan, "BRIDGEPEER");
521                         if (!ast_strlen_zero(pname))
522                                 ast_copy_string(buf, pname, len); /* a horrible kludge, but... how else? */
523                         else
524                                 buf[0] = 0;
525                 }
526                 ast_channel_unlock(chan);
527         } else if (!strcasecmp(data, "uniqueid")) {
528                 locked_copy_string(chan, buf, ast_channel_uniqueid(chan), len);
529         } else if (!strcasecmp(data, "transfercapability")) {
530                 locked_copy_string(chan, buf, transfercapability_table[ast_channel_transfercapability(chan) & 0x1f], len);
531         } else if (!strcasecmp(data, "callgroup")) {
532                 char groupbuf[256];
533
534                 locked_copy_string(chan, buf,  ast_print_group(groupbuf, sizeof(groupbuf), ast_channel_callgroup(chan)), len);
535         } else if (!strcasecmp(data, "pickupgroup")) {
536                 char groupbuf[256];
537
538                 locked_copy_string(chan, buf,  ast_print_group(groupbuf, sizeof(groupbuf), ast_channel_pickupgroup(chan)), len);
539         } else if (!strcasecmp(data, "namedcallgroup")) {
540                 struct ast_str *tmp_str = ast_str_alloca(1024);
541
542                 locked_copy_string(chan, buf,  ast_print_namedgroups(&tmp_str, ast_channel_named_callgroups(chan)), len);
543         } else if (!strcasecmp(data, "namedpickupgroup")) {
544                 struct ast_str *tmp_str = ast_str_alloca(1024);
545
546                 locked_copy_string(chan, buf,  ast_print_namedgroups(&tmp_str, ast_channel_named_pickupgroups(chan)), len);
547         } else if (!strcasecmp(data, "after_bridge_goto")) {
548                 ast_bridge_read_after_goto(chan, buf, len);
549         } else if (!strcasecmp(data, "amaflags")) {
550                 ast_channel_lock(chan);
551                 snprintf(buf, len, "%u", ast_channel_amaflags(chan));
552                 ast_channel_unlock(chan);
553         } else if (!strncasecmp(data, "secure_bridge_", 14)) {
554                 struct ast_datastore *ds;
555
556                 ast_channel_lock(chan);
557                 if ((ds = ast_channel_datastore_find(chan, &secure_call_info, NULL))) {
558                         struct ast_secure_call_store *encrypt = ds->data;
559                         if (!strcasecmp(data, "secure_bridge_signaling")) {
560                                 snprintf(buf, len, "%s", encrypt->signaling ? "1" : "");
561                         } else if (!strcasecmp(data, "secure_bridge_media")) {
562                                 snprintf(buf, len, "%s", encrypt->media ? "1" : "");
563                         }
564                 }
565                 ast_channel_unlock(chan);
566         } else if (!ast_channel_tech(chan) || !ast_channel_tech(chan)->func_channel_read || ast_channel_tech(chan)->func_channel_read(chan, function, data, buf, len)) {
567                 ast_log(LOG_WARNING, "Unknown or unavailable item requested: '%s'\n", data);
568                 ret = -1;
569         }
570
571         return ret;
572 }
573
574 static int func_channel_write_real(struct ast_channel *chan, const char *function,
575                               char *data, const char *value)
576 {
577         int ret = 0;
578         signed char gainset;
579
580         if (!strcasecmp(data, "language"))
581                 locked_string_field_set(chan, language, value);
582         else if (!strcasecmp(data, "parkinglot"))
583                 locked_string_field_set(chan, parkinglot, value);
584         else if (!strcasecmp(data, "musicclass"))
585                 locked_string_field_set(chan, musicclass, value);
586         else if (!strcasecmp(data, "accountcode"))
587                 locked_string_field_set(chan, accountcode, value);
588         else if (!strcasecmp(data, "userfield"))
589                 locked_string_field_set(chan, userfield, value);
590         else if (!strcasecmp(data, "after_bridge_goto")) {
591                 if (ast_strlen_zero(value)) {
592                         ast_bridge_discard_after_goto(chan);
593                 } else {
594                         ast_bridge_set_after_go_on(chan, ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan), value);
595                 }
596         } else if (!strcasecmp(data, "amaflags")) {
597                 ast_channel_lock(chan);
598                 if (isdigit(*value)) {
599                         int amaflags;
600                         sscanf(value, "%30d", &amaflags);
601                         ast_channel_amaflags_set(chan, amaflags);
602                 } else if (!strcasecmp(value,"OMIT")){
603                         ast_channel_amaflags_set(chan, 1);
604                 } else if (!strcasecmp(value,"BILLING")){
605                         ast_channel_amaflags_set(chan, 2);
606                 } else if (!strcasecmp(value,"DOCUMENTATION")){
607                         ast_channel_amaflags_set(chan, 3);
608                 }
609                 ast_channel_unlock(chan);
610         } else if (!strcasecmp(data, "peeraccount"))
611                 locked_string_field_set(chan, peeraccount, value);
612         else if (!strcasecmp(data, "hangupsource"))
613                 /* XXX - should we be forcing this here? */
614                 ast_set_hangupsource(chan, value, 0);
615 #ifdef CHANNEL_TRACE
616         else if (!strcasecmp(data, "trace")) {
617                 ast_channel_lock(chan);
618                 if (ast_true(value))
619                         ret = ast_channel_trace_enable(chan);
620                 else if (ast_false(value))
621                         ret = ast_channel_trace_disable(chan);
622                 else {
623                         ret = -1;
624                         ast_log(LOG_WARNING, "Invalid value for CHANNEL(trace).\n");
625                 }
626                 ast_channel_unlock(chan);
627         }
628 #endif
629         else if (!strcasecmp(data, "tonezone")) {
630                 struct ast_tone_zone *new_zone;
631                 if (!(new_zone = ast_get_indication_zone(value))) {
632                         ast_log(LOG_ERROR, "Unknown country code '%s' for tonezone. Check indications.conf for available country codes.\n", value);
633                         ret = -1;
634                 } else {
635                         ast_channel_lock(chan);
636                         if (ast_channel_zone(chan)) {
637                                 ast_channel_zone_set(chan, ast_tone_zone_unref(ast_channel_zone(chan)));
638                         }
639                         ast_channel_zone_set(chan, ast_tone_zone_ref(new_zone));
640                         ast_channel_unlock(chan);
641                         new_zone = ast_tone_zone_unref(new_zone);
642                 }
643         } else if (!strcasecmp(data, "dtmf_features")) {
644                 ret = ast_bridge_features_ds_set_string(chan, value);
645         } else if (!strcasecmp(data, "callgroup")) {
646                 ast_channel_lock(chan);
647                 ast_channel_callgroup_set(chan, ast_get_group(value));
648                 ast_channel_unlock(chan);
649         } else if (!strcasecmp(data, "pickupgroup")) {
650                 ast_channel_lock(chan);
651                 ast_channel_pickupgroup_set(chan, ast_get_group(value));
652                 ast_channel_unlock(chan);
653         } else if (!strcasecmp(data, "namedcallgroup")) {
654                 struct ast_namedgroups *groups = ast_get_namedgroups(value);
655
656                 ast_channel_lock(chan);
657                 ast_channel_named_callgroups_set(chan, groups);
658                 ast_channel_unlock(chan);
659                 ast_unref_namedgroups(groups);
660         } else if (!strcasecmp(data, "namedpickupgroup")) {
661                 struct ast_namedgroups *groups = ast_get_namedgroups(value);
662
663                 ast_channel_lock(chan);
664                 ast_channel_named_pickupgroups_set(chan, groups);
665                 ast_channel_unlock(chan);
666                 ast_unref_namedgroups(groups);
667         } else if (!strcasecmp(data, "txgain")) {
668                 sscanf(value, "%4hhd", &gainset);
669                 ast_channel_setoption(chan, AST_OPTION_TXGAIN, &gainset, sizeof(gainset), 0);
670         } else if (!strcasecmp(data, "rxgain")) {
671                 sscanf(value, "%4hhd", &gainset);
672                 ast_channel_setoption(chan, AST_OPTION_RXGAIN, &gainset, sizeof(gainset), 0);
673         } else if (!strcasecmp(data, "transfercapability")) {
674                 unsigned short i;
675
676                 ast_channel_lock(chan);
677                 for (i = 0; i < 0x20; i++) {
678                         if (!strcasecmp(transfercapability_table[i], value) && strcmp(value, "UNK")) {
679                                 ast_channel_transfercapability_set(chan, i);
680                                 break;
681                         }
682                 }
683                 ast_channel_unlock(chan);
684         } else if (!strcasecmp(data, "hangup_handler_pop")) {
685                 /* Pop one hangup handler before pushing the new handler. */
686                 ast_pbx_hangup_handler_pop(chan);
687                 ast_pbx_hangup_handler_push(chan, value);
688         } else if (!strcasecmp(data, "hangup_handler_push")) {
689                 ast_pbx_hangup_handler_push(chan, value);
690         } else if (!strcasecmp(data, "hangup_handler_wipe")) {
691                 /* Pop all hangup handlers before pushing the new handler. */
692                 while (ast_pbx_hangup_handler_pop(chan)) {
693                 }
694                 ast_pbx_hangup_handler_push(chan, value);
695         } else if (!strncasecmp(data, "secure_bridge_", 14)) {
696                 struct ast_datastore *ds;
697                 struct ast_secure_call_store *store;
698
699                 if (!chan || !value) {
700                         return -1;
701                 }
702
703                 ast_channel_lock(chan);
704                 if (!(ds = ast_channel_datastore_find(chan, &secure_call_info, NULL))) {
705                         if (!(ds = ast_datastore_alloc(&secure_call_info, NULL))) {
706                                 ast_channel_unlock(chan);
707                                 return -1;
708                         }
709                         if (!(store = ast_calloc(1, sizeof(*store)))) {
710                                 ast_channel_unlock(chan);
711                                 ast_free(ds);
712                                 return -1;
713                         }
714                         ds->data = store;
715                         ast_channel_datastore_add(chan, ds);
716                 } else {
717                         store = ds->data;
718                 }
719
720                 if (!strcasecmp(data, "secure_bridge_signaling")) {
721                         store->signaling = ast_true(value) ? 1 : 0;
722                 } else if (!strcasecmp(data, "secure_bridge_media")) {
723                         store->media = ast_true(value) ? 1 : 0;
724                 }
725                 ast_channel_unlock(chan);
726         } else if (!ast_channel_tech(chan)->func_channel_write
727                  || ast_channel_tech(chan)->func_channel_write(chan, function, data, value)) {
728                 ast_log(LOG_WARNING, "Unknown or unavailable item requested: '%s'\n",
729                                 data);
730                 ret = -1;
731         }
732
733         return ret;
734 }
735
736 static int func_channel_write(struct ast_channel *chan, const char *function, char *data, const char *value)
737 {
738         int res;
739         ast_chan_write_info_t write_info = {
740                 .version = AST_CHAN_WRITE_INFO_T_VERSION,
741                 .write_fn = func_channel_write_real,
742                 .chan = chan,
743                 .function = function,
744                 .data = data,
745                 .value = value,
746         };
747
748         if (!chan) {
749                 ast_log(LOG_WARNING, "No channel was provided to %s function.\n", function);
750                 return -1;
751         }
752
753         res = func_channel_write_real(chan, function, data, value);
754         ast_channel_setoption(chan, AST_OPTION_CHANNEL_WRITE, &write_info, sizeof(write_info), 0);
755
756         return res;
757 }
758
759 static struct ast_custom_function channel_function = {
760         .name = "CHANNEL",
761         .read = func_channel_read,
762         .write = func_channel_write,
763 };
764
765 static int func_channels_read(struct ast_channel *chan, const char *function, char *data, char *buf, size_t maxlen)
766 {
767         struct ast_channel *c = NULL;
768         regex_t re;
769         int res;
770         size_t buflen = 0;
771         struct ast_channel_iterator *iter;
772
773         buf[0] = '\0';
774
775         if (!ast_strlen_zero(data)) {
776                 if ((res = regcomp(&re, data, REG_EXTENDED | REG_ICASE | REG_NOSUB))) {
777                         regerror(res, &re, buf, maxlen);
778                         ast_log(LOG_WARNING, "Error compiling regular expression for %s(%s): %s\n", function, data, buf);
779                         return -1;
780                 }
781         }
782
783         if (!(iter = ast_channel_iterator_all_new())) {
784                 if (!ast_strlen_zero(data)) {
785                         regfree(&re);
786                 }
787                 return -1;
788         }
789
790         while ((c = ast_channel_iterator_next(iter))) {
791                 ast_channel_lock(c);
792                 if (ast_strlen_zero(data) || regexec(&re, ast_channel_name(c), 0, NULL, 0) == 0) {
793                         size_t namelen = strlen(ast_channel_name(c));
794                         if (buflen + namelen + (ast_strlen_zero(buf) ? 0 : 1) + 1 < maxlen) {
795                                 if (!ast_strlen_zero(buf)) {
796                                         strcat(buf, " ");
797                                         buflen++;
798                                 }
799                                 strcat(buf, ast_channel_name(c));
800                                 buflen += namelen;
801                         } else {
802                                 ast_log(LOG_WARNING, "Number of channels exceeds the available buffer space.  Output will be truncated!\n");
803                         }
804                 }
805                 ast_channel_unlock(c);
806                 c = ast_channel_unref(c);
807         }
808
809         ast_channel_iterator_destroy(iter);
810
811         if (!ast_strlen_zero(data)) {
812                 regfree(&re);
813         }
814
815         return 0;
816 }
817
818 static struct ast_custom_function channels_function = {
819         .name = "CHANNELS",
820         .read = func_channels_read,
821 };
822
823 static int func_mchan_read(struct ast_channel *chan, const char *function,
824                              char *data, struct ast_str **buf, ssize_t len)
825 {
826         struct ast_channel *mchan;
827         char *template = ast_alloca(4 + strlen(data));
828
829         if (!chan) {
830                 ast_log(LOG_WARNING, "No channel was provided to %s function.\n", function);
831                 return -1;
832         }
833
834         mchan = ast_channel_get_by_name(ast_channel_linkedid(chan));
835         sprintf(template, "${%s}", data); /* SAFE */
836         ast_str_substitute_variables(buf, len, mchan ? mchan : chan, template);
837         if (mchan) {
838                 ast_channel_unref(mchan);
839         }
840         return 0;
841 }
842
843 static int func_mchan_write(struct ast_channel *chan, const char *function,
844                               char *data, const char *value)
845 {
846         struct ast_channel *mchan;
847
848         if (!chan) {
849                 ast_log(LOG_WARNING, "No channel was provided to %s function.\n", function);
850                 return -1;
851         }
852
853         mchan = ast_channel_get_by_name(ast_channel_linkedid(chan));
854         pbx_builtin_setvar_helper(mchan ? mchan : chan, data, value);
855         if (mchan) {
856                 ast_channel_unref(mchan);
857         }
858         return 0;
859 }
860
861 static struct ast_custom_function mchan_function = {
862         .name = "MASTER_CHANNEL",
863         .read2 = func_mchan_read,
864         .write = func_mchan_write,
865 };
866
867 static int unload_module(void)
868 {
869         int res = 0;
870
871         res |= ast_custom_function_unregister(&channel_function);
872         res |= ast_custom_function_unregister(&channels_function);
873         res |= ast_custom_function_unregister(&mchan_function);
874
875         return res;
876 }
877
878 static int load_module(void)
879 {
880         int res = 0;
881
882         res |= ast_custom_function_register(&channel_function);
883         res |= ast_custom_function_register(&channels_function);
884         res |= ast_custom_function_register(&mchan_function);
885
886         return res;
887 }
888
889 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Channel information dialplan functions");