Hangup handlers - Dialplan subroutines that run when the channel hangs up.
[asterisk/asterisk.git] / funcs / func_channel.c
index ce6a81e..699f3b6 100644 (file)
 
 /*! \file
  *
- * \brief Channel info dialplan function
+ * \brief Channel info dialplan functions
  *
  * \author Kevin P. Fleming <kpfleming@digium.com>
+ * \author Ben Winslow
  * 
+ * \ingroup functions
  */
 
-#include <stdlib.h>
-#include <string.h>
-#include <sys/types.h>
+/*** MODULEINFO
+       <support_level>core</support_level>
+ ***/
 
 #include "asterisk.h"
 
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include <regex.h>
+#include <ctype.h>
+
 #include "asterisk/module.h"
 #include "asterisk/channel.h"
 #include "asterisk/pbx.h"
-#include "asterisk/logger.h"
 #include "asterisk/utils.h"
 #include "asterisk/app.h"
 #include "asterisk/indications.h"
 #include "asterisk/stringfields.h"
+#include "asterisk/global_datastores.h"
+
+/*** DOCUMENTATION
+       <function name="CHANNELS" language="en_US">
+               <synopsis>
+                       Gets the list of channels, optionally filtering by a regular expression.
+               </synopsis>
+               <syntax>
+                       <parameter name="regular_expression" />
+               </syntax>
+               <description>
+                       <para>Gets the list of channels, optionally filtering by a <replaceable>regular_expression</replaceable>. If
+                       no argument is provided, all known channels are returned. The
+                       <replaceable>regular_expression</replaceable> must correspond to
+                       the POSIX.2 specification, as shown in <emphasis>regex(7)</emphasis>. The list returned
+                       will be space-delimited.</para>
+               </description>
+       </function>
+       <function name="MASTER_CHANNEL" language="en_US">
+               <synopsis>
+                       Gets or sets variables on the master channel
+               </synopsis>
+               <description>
+                       <para>Allows access to the channel which created the current channel, if any.  If the channel is already
+                       a master channel, then accesses local channel variables.</para>
+               </description>
+       </function>
+       <function name="CHANNEL" language="en_US">
+               <synopsis>
+                       Gets/sets various pieces of information about the channel.
+               </synopsis>
+               <syntax>
+                       <parameter name="item" required="true">
+                               <para>Standard items (provided by all channel technologies) are:</para>
+                               <enumlist>
+                                       <enum name="audioreadformat">
+                                               <para>R/O format currently being read.</para>
+                                       </enum>
+                                       <enum name="audionativeformat">
+                                               <para>R/O format used natively for audio.</para>
+                                       </enum>
+                                       <enum name="audiowriteformat">
+                                               <para>R/O format currently being written.</para>
+                                       </enum>
+                                       <enum name="callgroup">
+                                               <para>R/W call groups for call pickup.</para>
+                                       </enum>
+                                       <enum name="pickupgroup">
+                                               <para>R/W call groups for call pickup.</para>
+                                       </enum>
+                                       <enum name="channeltype">
+                                               <para>R/O technology used for channel.</para>
+                                       </enum>
+                                       <enum name="checkhangup">
+                                               <para>R/O Whether the channel is hanging up (1/0)</para>
+                                       </enum>
+                                       <enum name="hangup_handler_pop">
+                                               <para>W/O Replace the most recently added hangup handler
+                                               with a new hangup handler on the channel if supplied.  The
+                                               assigned string is passed to the Gosub application when
+                                               the channel is hung up.  Any optionally omitted context
+                                               and exten are supplied by the channel pushing the handler
+                                               before it is pushed.</para>
+                                       </enum>
+                                       <enum name="hangup_handler_push">
+                                               <para>W/O Push a hangup handler onto the channel hangup
+                                               handler stack.  The assigned string is passed to the
+                                               Gosub application when the channel is hung up.  Any
+                                               optionally omitted context and exten are supplied by the
+                                               channel pushing the handler before it is pushed.</para>
+                                       </enum>
+                                       <enum name="hangup_handler_wipe">
+                                               <para>W/O Wipe the entire hangup handler stack and replace
+                                               with a new hangup handler on the channel if supplied.  The
+                                               assigned string is passed to the Gosub application when
+                                               the channel is hung up.  Any optionally omitted context
+                                               and exten are supplied by the channel pushing the handler
+                                               before it is pushed.</para>
+                                       </enum>
+                                       <enum name="language">
+                                               <para>R/W language for sounds played.</para>
+                                       </enum>
+                                       <enum name="musicclass">
+                                               <para>R/W class (from musiconhold.conf) for hold music.</para>
+                                       </enum>
+                                       <enum name="name">
+                                               <para>The name of the channel</para>
+                                       </enum>
+                                       <enum name="parkinglot">
+                                               <para>R/W parkinglot for parking.</para>
+                                       </enum>
+                                       <enum name="rxgain">
+                                               <para>R/W set rxgain level on channel drivers that support it.</para>
+                                       </enum>
+                                       <enum name="secure_bridge_signaling">
+                                               <para>Whether or not channels bridged to this channel require secure signaling</para>
+                                       </enum>
+                                       <enum name="secure_bridge_media">
+                                               <para>Whether or not channels bridged to this channel require secure media</para>
+                                       </enum>
+                                       <enum name="state">
+                                               <para>R/O state for channel</para>
+                                       </enum>
+                                       <enum name="tonezone">
+                                               <para>R/W zone for indications played</para>
+                                       </enum>
+                                       <enum name="transfercapability">
+                                               <para>R/W ISDN Transfer Capability, one of:</para>
+                                               <enumlist>
+                                                       <enum name="SPEECH" />
+                                                       <enum name="DIGITAL" />
+                                                       <enum name="RESTRICTED_DIGITAL" />
+                                                       <enum name="3K1AUDIO" />
+                                                       <enum name="DIGITAL_W_TONES" />
+                                                       <enum name="VIDEO" />
+                                               </enumlist>
+                                       </enum>
+                                       <enum name="txgain">
+                                               <para>R/W set txgain level on channel drivers that support it.</para>
+                                       </enum>
+                                       <enum name="videonativeformat">
+                                               <para>R/O format used natively for video</para>
+                                       </enum>
+                                       <enum name="trace">
+                                               <para>R/W whether or not context tracing is enabled, only available
+                                               <emphasis>if CHANNEL_TRACE is defined</emphasis>.</para>
+                                       </enum>
+                               </enumlist>
+                               <para><emphasis>chan_sip</emphasis> provides the following additional options:</para>
+                               <enumlist>
+                                       <enum name="peerip">
+                                               <para>R/O Get the IP address of the peer.</para>
+                                       </enum>
+                                       <enum name="recvip">
+                                               <para>R/O Get the source IP address of the peer.</para>
+                                       </enum>
+                                       <enum name="from">
+                                               <para>R/O Get the URI from the From: header.</para>
+                                       </enum>
+                                       <enum name="uri">
+                                               <para>R/O Get the URI from the Contact: header.</para>
+                                       </enum>
+                                       <enum name="useragent">
+                                               <para>R/O Get the useragent.</para>
+                                       </enum>
+                                       <enum name="peername">
+                                               <para>R/O Get the name of the peer.</para>
+                                       </enum>
+                                       <enum name="t38passthrough">
+                                               <para>R/O <literal>1</literal> if T38 is offered or enabled in this channel,
+                                               otherwise <literal>0</literal></para>
+                                       </enum>
+                                       <enum name="rtpqos">
+                                               <para>R/O Get QOS information about the RTP stream</para>
+                                               <para>    This option takes two additional arguments:</para>
+                                               <para>    Argument 1:</para>
+                                               <para>     <literal>audio</literal>             Get data about the audio stream</para>
+                                               <para>     <literal>video</literal>             Get data about the video stream</para>
+                                               <para>     <literal>text</literal>              Get data about the text stream</para>
+                                               <para>    Argument 2:</para>
+                                               <para>     <literal>local_ssrc</literal>        Local SSRC (stream ID)</para>
+                                               <para>     <literal>local_lostpackets</literal> Local lost packets</para>
+                                               <para>     <literal>local_jitter</literal>      Local calculated jitter</para>
+                                               <para>     <literal>local_maxjitter</literal>   Local calculated jitter (maximum)</para>
+                                               <para>     <literal>local_minjitter</literal>   Local calculated jitter (minimum)</para>
+                                               <para>     <literal>local_normdevjitter</literal>Local calculated jitter (normal deviation)</para>
+                                               <para>     <literal>local_stdevjitter</literal> Local calculated jitter (standard deviation)</para>
+                                               <para>     <literal>local_count</literal>       Number of received packets</para>
+                                               <para>     <literal>remote_ssrc</literal>       Remote SSRC (stream ID)</para>
+                                               <para>     <literal>remote_lostpackets</literal>Remote lost packets</para>
+                                               <para>     <literal>remote_jitter</literal>     Remote reported jitter</para>
+                                               <para>     <literal>remote_maxjitter</literal>  Remote calculated jitter (maximum)</para>
+                                               <para>     <literal>remote_minjitter</literal>  Remote calculated jitter (minimum)</para>
+                                               <para>     <literal>remote_normdevjitter</literal>Remote calculated jitter (normal deviation)</para>
+                                               <para>     <literal>remote_stdevjitter</literal>Remote calculated jitter (standard deviation)</para>
+                                               <para>     <literal>remote_count</literal>      Number of transmitted packets</para>
+                                               <para>     <literal>rtt</literal>               Round trip time</para>
+                                               <para>     <literal>maxrtt</literal>            Round trip time (maximum)</para>
+                                               <para>     <literal>minrtt</literal>            Round trip time (minimum)</para>
+                                               <para>     <literal>normdevrtt</literal>        Round trip time (normal deviation)</para>
+                                               <para>     <literal>stdevrtt</literal>          Round trip time (standard deviation)</para>
+                                               <para>     <literal>all</literal>               All statistics (in a form suited to logging,
+                                               but not for parsing)</para>
+                                       </enum>
+                                       <enum name="rtpdest">
+                                               <para>R/O Get remote RTP destination information.</para>
+                                               <para>   This option takes one additional argument:</para>
+                                               <para>    Argument 1:</para>
+                                               <para>     <literal>audio</literal>             Get audio destination</para>
+                                               <para>     <literal>video</literal>             Get video destination</para>
+                                               <para>     <literal>text</literal>              Get text destination</para>
+                                       </enum>
+                               </enumlist>
+                               <para><emphasis>chan_iax2</emphasis> provides the following additional options:</para>
+                               <enumlist>
+                                       <enum name="peerip">
+                                               <para>R/O Get the peer's ip address.</para>
+                                       </enum>
+                                       <enum name="peername">
+                                               <para>R/O Get the peer's username.</para>
+                                       </enum>
+                               </enumlist>
+                               <para><emphasis>chan_dahdi</emphasis> provides the following additional options:</para>
+                               <enumlist>
+                                       <enum name="dahdi_channel">
+                                               <para>R/O DAHDI channel related to this channel.</para>
+                                       </enum>
+                                       <enum name="dahdi_span">
+                                               <para>R/O DAHDI span related to this channel.</para>
+                                       </enum>
+                                       <enum name="dahdi_type">
+                                               <para>R/O DAHDI channel type, one of:</para>
+                                               <enumlist>
+                                                       <enum name="analog" />
+                                                       <enum name="mfc/r2" />
+                                                       <enum name="pri" />
+                                                       <enum name="pseudo" />
+                                                       <enum name="ss7" />
+                                               </enumlist>
+                                       </enum>
+                                       <enum name="keypad_digits">
+                                               <para>R/O PRI Keypad digits that came in with the SETUP message.</para>
+                                       </enum>
+                                       <enum name="reversecharge">
+                                               <para>R/O PRI Reverse Charging Indication, one of:</para>
+                                               <enumlist>
+                                                       <enum name="-1"> <para>None</para></enum>
+                                                       <enum name=" 1"> <para>Reverse Charging Requested</para></enum>
+                                               </enumlist>
+                                       </enum>
+                                       <enum name="no_media_path">
+                                               <para>R/O PRI Nonzero if the channel has no B channel.
+                                               The channel is either on hold or a call waiting call.</para>
+                                       </enum>
+                                       <enum name="buffers">
+                                               <para>W/O Change the channel's buffer policy (for the current call only)</para>
+                                               <para>This option takes two arguments:</para>
+                                               <para>  Number of buffers,</para>
+                                               <para>  Buffer policy being one of:</para>
+                                               <para>      <literal>full</literal></para>
+                                               <para>      <literal>immediate</literal></para>
+                                               <para>      <literal>half</literal></para>
+                                       </enum>
+                                       <enum name="echocan_mode">
+                                               <para>W/O Change the configuration of the active echo
+                                               canceller on the channel (if any), for the current call
+                                               only.</para>
+                                               <para>Possible values are:</para>
+                                               <para>  <literal>on</literal>   Normal mode (the echo canceller is actually reinitalized)</para>
+                                               <para>  <literal>off</literal>  Disabled</para>
+                                               <para>  <literal>fax</literal>  FAX/data mode (NLP disabled if possible, otherwise
+                                                       completely disabled)</para>
+                                               <para>  <literal>voice</literal>        Voice mode (returns from FAX mode, reverting the changes that were made)</para>
+                                       </enum>
+                               </enumlist>
+                               <para><emphasis>chan_ooh323</emphasis> provides the following additional options:</para>
+                               <enumlist>
+                                       <enum name="faxdetect">
+                                               <para>Fax Detect [R/W]</para>
+                                               <para>Returns 0 or 1</para>
+                                               <para>Write yes or no</para>
+                                       </enum>
+                                       <enum name="t38support">
+                                               <para>t38support [R/W]</para>
+                                               <para>Returns 0 or 1</para>
+                                               <para>Write yes or no</para>
+                                       </enum>
+                                       <enum name="h323id">
+                                               <para>Returns h323id [R]</para>
+                                       </enum>
+                               </enumlist>
+                       </parameter>
+               </syntax>
+               <description>
+                       <para>Gets/sets various pieces of information about the channel, additional <replaceable>item</replaceable> may
+                       be available from the channel driver; see its documentation for details. Any <replaceable>item</replaceable>
+                       requested that is not available on the current channel will return an empty string.</para>
+               </description>
+       </function>
+ ***/
+
 #define locked_copy_string(chan, dest, source, len) \
        do { \
-               ast_mutex_lock(&chan->lock); \
+               ast_channel_lock(chan); \
                ast_copy_string(dest, source, len); \
-               ast_mutex_unlock(&chan->lock); \
+               ast_channel_unlock(chan); \
        } while (0)
 #define locked_string_field_set(chan, field, source) \
        do { \
-               ast_mutex_lock(&chan->lock); \
-               ast_string_field_set(chan, field, source); \
-               ast_mutex_unlock(&chan->lock); \
+               ast_channel_lock(chan); \
+               ast_channel_##field##_set(chan, source); \
+               ast_channel_unlock(chan); \
        } while (0)
 
-static int func_channel_read(struct ast_channel *chan, char *function,
+static const char * const transfercapability_table[0x20] = {
+       "SPEECH", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK",
+       "DIGITAL", "RESTRICTED_DIGITAL", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK",
+       "3K1AUDIO", "DIGITAL_W_TONES", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK",
+       "VIDEO", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK", "UNK", };
+
+static int func_channel_read(struct ast_channel *chan, const char *function,
                             char *data, char *buf, size_t len)
 {
        int ret = 0;
+       char tmp[512];
+       struct ast_format_cap *tmpcap;
 
-       if (!strcasecmp(data, "audionativeformat"))
-               /* use the _multiple version when chan->nativeformats holds multiple formats */
-               /* ast_getformatname_multiple(buf, len, chan->nativeformats & AST_FORMAT_AUDIO_MASK); */
-               ast_copy_string(buf, ast_getformatname(chan->nativeformats & AST_FORMAT_AUDIO_MASK), len);
-       else if (!strcasecmp(data, "videonativeformat"))
-               /* use the _multiple version when chan->nativeformats holds multiple formats */
-               /* ast_getformatname_multiple(buf, len, chan->nativeformats & AST_FORMAT_VIDEO_MASK); */
-               ast_copy_string(buf, ast_getformatname(chan->nativeformats & AST_FORMAT_VIDEO_MASK), len);
-       else if (!strcasecmp(data, "audioreadformat"))
-               ast_copy_string(buf, ast_getformatname(chan->readformat), len);
-       else if (!strcasecmp(data, "audiowriteformat"))
-               ast_copy_string(buf, ast_getformatname(chan->writeformat), len);
-       else if (!strcasecmp(data, "tonezone") && chan->zone)
-               locked_copy_string(chan, buf, chan->zone->country, len);
+       if (!strcasecmp(data, "audionativeformat")) {
+               if ((tmpcap = ast_format_cap_get_type(ast_channel_nativeformats(chan), AST_FORMAT_TYPE_AUDIO))) {
+                       ast_copy_string(buf, ast_getformatname_multiple(tmp, sizeof(tmp), tmpcap), len);
+                       tmpcap = ast_format_cap_destroy(tmpcap);
+               }
+       } else if (!strcasecmp(data, "videonativeformat")) {
+               if ((tmpcap = ast_format_cap_get_type(ast_channel_nativeformats(chan), AST_FORMAT_TYPE_VIDEO))) {
+                       ast_copy_string(buf, ast_getformatname_multiple(tmp, sizeof(tmp), tmpcap), len);
+                       tmpcap = ast_format_cap_destroy(tmpcap);
+               }
+       } else if (!strcasecmp(data, "audioreadformat")) {
+               ast_copy_string(buf, ast_getformatname(ast_channel_readformat(chan)), len);
+       } else if (!strcasecmp(data, "audiowriteformat")) {
+               ast_copy_string(buf, ast_getformatname(ast_channel_writeformat(chan)), len);
+#ifdef CHANNEL_TRACE
+       } else if (!strcasecmp(data, "trace")) {
+               ast_channel_lock(chan);
+               ast_copy_string(buf, ast_channel_trace_is_enabled(chan) ? "1" : "0", len);
+               ast_channel_unlock(chan);
+#endif
+       } else if (!strcasecmp(data, "tonezone") && ast_channel_zone(chan))
+               locked_copy_string(chan, buf, ast_channel_zone(chan)->country, len);
        else if (!strcasecmp(data, "language"))
-               locked_copy_string(chan, buf, chan->language, len);
+               locked_copy_string(chan, buf, ast_channel_language(chan), len);
        else if (!strcasecmp(data, "musicclass"))
-               locked_copy_string(chan, buf, chan->musicclass, len);
+               locked_copy_string(chan, buf, ast_channel_musicclass(chan), len);
+       else if (!strcasecmp(data, "name")) {
+               locked_copy_string(chan, buf, ast_channel_name(chan), len);
+       } else if (!strcasecmp(data, "parkinglot"))
+               locked_copy_string(chan, buf, ast_channel_parkinglot(chan), len);
        else if (!strcasecmp(data, "state"))
-               locked_copy_string(chan, buf, ast_state2str(chan->_state), len);
+               locked_copy_string(chan, buf, ast_state2str(ast_channel_state(chan)), len);
        else if (!strcasecmp(data, "channeltype"))
-               locked_copy_string(chan, buf, chan->tech->type, len);
-       else if (!strcasecmp(data, "callgroup")) {
+               locked_copy_string(chan, buf, ast_channel_tech(chan)->type, len);
+       else if (!strcasecmp(data, "accountcode"))
+               locked_copy_string(chan, buf, ast_channel_accountcode(chan), len);
+       else if (!strcasecmp(data, "checkhangup")) {
+               ast_channel_lock(chan);
+               ast_copy_string(buf, ast_check_hangup(chan) ? "1" : "0", len);
+               ast_channel_unlock(chan);
+       } else if (!strcasecmp(data, "peeraccount"))
+               locked_copy_string(chan, buf, ast_channel_peeraccount(chan), len);
+       else if (!strcasecmp(data, "hangupsource"))
+               locked_copy_string(chan, buf, ast_channel_hangupsource(chan), len);
+       else if (!strcasecmp(data, "appname") && ast_channel_appl(chan))
+               locked_copy_string(chan, buf, ast_channel_appl(chan), len);
+       else if (!strcasecmp(data, "appdata") && ast_channel_data(chan))
+               locked_copy_string(chan, buf, ast_channel_data(chan), len);
+       else if (!strcasecmp(data, "exten") && ast_channel_data(chan))
+               locked_copy_string(chan, buf, ast_channel_exten(chan), len);
+       else if (!strcasecmp(data, "context") && ast_channel_data(chan))
+               locked_copy_string(chan, buf, ast_channel_context(chan), len);
+       else if (!strcasecmp(data, "userfield") && ast_channel_data(chan))
+               locked_copy_string(chan, buf, ast_channel_userfield(chan), len);
+       else if (!strcasecmp(data, "channame") && ast_channel_data(chan))
+               locked_copy_string(chan, buf, ast_channel_name(chan), len);
+       else if (!strcasecmp(data, "linkedid")) {
+               ast_channel_lock(chan);
+               if (ast_strlen_zero(ast_channel_linkedid(chan))) {
+                       /* fall back on the channel's uniqueid if linkedid is unset */
+                       ast_copy_string(buf, ast_channel_uniqueid(chan), len);
+               }
+               else {
+                       ast_copy_string(buf, ast_channel_linkedid(chan), len);
+               }
+               ast_channel_unlock(chan);
+       } else if (!strcasecmp(data, "peer")) {
+               struct ast_channel *p;
+               ast_channel_lock(chan);
+               p = ast_bridged_channel(chan);
+               if (p || ast_channel_tech(chan) || ast_channel_cdr(chan)) /* dummy channel? if so, we hid the peer name in the language */
+                       ast_copy_string(buf, (p ? ast_channel_name(p) : ""), len);
+               else {
+                       /* a dummy channel can still pass along bridged peer info via
+                           the BRIDGEPEER variable */
+                       const char *pname = pbx_builtin_getvar_helper(chan, "BRIDGEPEER");
+                       if (!ast_strlen_zero(pname))
+                               ast_copy_string(buf, pname, len); /* a horrible kludge, but... how else? */
+                       else
+                               buf[0] = 0;
+               }
+               ast_channel_unlock(chan);
+       } else if (!strcasecmp(data, "uniqueid")) {
+               locked_copy_string(chan, buf, ast_channel_uniqueid(chan), len);
+       } else if (!strcasecmp(data, "transfercapability")) {
+               locked_copy_string(chan, buf, transfercapability_table[ast_channel_transfercapability(chan) & 0x1f], len);
+       } else if (!strcasecmp(data, "callgroup")) {
+               char groupbuf[256];
+               locked_copy_string(chan, buf,  ast_print_group(groupbuf, sizeof(groupbuf), ast_channel_callgroup(chan)), len);
+       } else if (!strcasecmp(data, "pickupgroup")) {
                char groupbuf[256];
-               locked_copy_string(chan, buf,  ast_print_group(groupbuf, sizeof(groupbuf), chan->callgroup), len);
-       } else if (!chan->tech->func_channel_read
-                || chan->tech->func_channel_read(chan, function, data, buf, len)) {
+               locked_copy_string(chan, buf,  ast_print_group(groupbuf, sizeof(groupbuf), ast_channel_pickupgroup(chan)), len);
+       } else if (!strcasecmp(data, "amaflags")) {
+               char amabuf[256];
+               snprintf(amabuf,sizeof(amabuf), "%d", ast_channel_amaflags(chan));
+               locked_copy_string(chan, buf, amabuf, len);
+       } else if (!strncasecmp(data, "secure_bridge_", 14)) {
+               struct ast_datastore *ds;
+               ast_channel_lock(chan);
+               if ((ds = ast_channel_datastore_find(chan, &secure_call_info, NULL))) {
+                       struct ast_secure_call_store *encrypt = ds->data;
+                       if (!strcasecmp(data, "secure_bridge_signaling")) {
+                               snprintf(buf, len, "%s", encrypt->signaling ? "1" : "");
+                       } else if (!strcasecmp(data, "secure_bridge_media")) {
+                               snprintf(buf, len, "%s", encrypt->media ? "1" : "");
+                       }
+               }
+               ast_channel_unlock(chan);
+       } 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)) {
                ast_log(LOG_WARNING, "Unknown or unavailable item requested: '%s'\n", data);
                ret = -1;
        }
@@ -89,19 +465,131 @@ static int func_channel_read(struct ast_channel *chan, char *function,
        return ret;
 }
 
-static int func_channel_write(struct ast_channel *chan, char *function,
+static int func_channel_write_real(struct ast_channel *chan, const char *function,
                              char *data, const char *value)
 {
        int ret = 0;
+       signed char gainset;
 
        if (!strcasecmp(data, "language"))
                locked_string_field_set(chan, language, value);
+       else if (!strcasecmp(data, "parkinglot"))
+               locked_string_field_set(chan, parkinglot, value);
        else if (!strcasecmp(data, "musicclass"))
                locked_string_field_set(chan, musicclass, value);
-       else if (!strcasecmp(data, "callgroup"))
-               chan->callgroup = ast_get_group(data);
-       else if (!chan->tech->func_channel_write
-                || chan->tech->func_channel_write(chan, function, data, value)) {
+       else if (!strcasecmp(data, "accountcode"))
+               locked_string_field_set(chan, accountcode, value);
+       else if (!strcasecmp(data, "userfield"))
+               locked_string_field_set(chan, userfield, value);
+       else if (!strcasecmp(data, "amaflags")) {
+               ast_channel_lock(chan);
+               if(isdigit(*value)) {
+                       int amaflags;
+                       sscanf(value, "%30d", &amaflags);
+                       ast_channel_amaflags_set(chan, amaflags);
+               } else if (!strcasecmp(value,"OMIT")){
+                       ast_channel_amaflags_set(chan, 1);
+               } else if (!strcasecmp(value,"BILLING")){
+                       ast_channel_amaflags_set(chan, 2);
+               } else if (!strcasecmp(value,"DOCUMENTATION")){
+                       ast_channel_amaflags_set(chan, 3);
+               }
+               ast_channel_unlock(chan);
+       } else if (!strcasecmp(data, "peeraccount"))
+               locked_string_field_set(chan, peeraccount, value);
+       else if (!strcasecmp(data, "hangupsource"))
+               /* XXX - should we be forcing this here? */
+               ast_set_hangupsource(chan, value, 0);
+#ifdef CHANNEL_TRACE
+       else if (!strcasecmp(data, "trace")) {
+               ast_channel_lock(chan);
+               if (ast_true(value)) 
+                       ret = ast_channel_trace_enable(chan);
+               else if (ast_false(value))
+                       ret = ast_channel_trace_disable(chan);
+               else {
+                       ret = -1;
+                       ast_log(LOG_WARNING, "Invalid value for CHANNEL(trace).\n");
+               }
+               ast_channel_unlock(chan);
+       }
+#endif
+       else if (!strcasecmp(data, "tonezone")) {
+               struct ast_tone_zone *new_zone;
+               if (!(new_zone = ast_get_indication_zone(value))) {
+                       ast_log(LOG_ERROR, "Unknown country code '%s' for tonezone. Check indications.conf for available country codes.\n", value);
+                       ret = -1;       
+               } else {
+                       ast_channel_lock(chan);
+                       if (ast_channel_zone(chan)) {
+                               ast_channel_zone_set(chan, ast_tone_zone_unref(ast_channel_zone(chan)));
+                       }
+                       ast_channel_zone_set(chan, ast_tone_zone_ref(new_zone));
+                       ast_channel_unlock(chan);
+                       new_zone = ast_tone_zone_unref(new_zone);
+               }
+       } else if (!strcasecmp(data, "callgroup")) {
+               ast_channel_callgroup_set(chan, ast_get_group(value));
+       } else if (!strcasecmp(data, "pickupgroup")) {
+               ast_channel_pickupgroup_set(chan, ast_get_group(value));
+       } else if (!strcasecmp(data, "txgain")) {
+               sscanf(value, "%4hhd", &gainset);
+               ast_channel_setoption(chan, AST_OPTION_TXGAIN, &gainset, sizeof(gainset), 0);
+       } else if (!strcasecmp(data, "rxgain")) {
+               sscanf(value, "%4hhd", &gainset);
+               ast_channel_setoption(chan, AST_OPTION_RXGAIN, &gainset, sizeof(gainset), 0);
+       } else if (!strcasecmp(data, "transfercapability")) {
+               unsigned short i;
+               for (i = 0; i < 0x20; i++) {
+                       if (!strcasecmp(transfercapability_table[i], value) && strcmp(value, "UNK")) {
+                               ast_channel_transfercapability_set(chan, i);
+                               break;
+                       }
+               }
+       } else if (!strcasecmp(data, "hangup_handler_pop")) {
+               /* Pop one hangup handler before pushing the new handler. */
+               ast_pbx_hangup_handler_pop(chan);
+               ast_pbx_hangup_handler_push(chan, value);
+       } else if (!strcasecmp(data, "hangup_handler_push")) {
+               ast_pbx_hangup_handler_push(chan, value);
+       } else if (!strcasecmp(data, "hangup_handler_wipe")) {
+               /* Pop all hangup handlers before pushing the new handler. */
+               while (ast_pbx_hangup_handler_pop(chan)) {
+               }
+               ast_pbx_hangup_handler_push(chan, value);
+       } else if (!strncasecmp(data, "secure_bridge_", 14)) {
+               struct ast_datastore *ds;
+               struct ast_secure_call_store *store;
+
+               if (!chan || !value) {
+                       return -1;
+               }
+
+               ast_channel_lock(chan);
+               if (!(ds = ast_channel_datastore_find(chan, &secure_call_info, NULL))) {
+                       if (!(ds = ast_datastore_alloc(&secure_call_info, NULL))) {
+                               ast_channel_unlock(chan);
+                               return -1;
+                       }
+                       if (!(store = ast_calloc(1, sizeof(*store)))) {
+                               ast_channel_unlock(chan);
+                               ast_free(ds);
+                               return -1;
+                       }
+                       ds->data = store;
+                       ast_channel_datastore_add(chan, ds);
+               } else {
+                       store = ds->data;
+               }
+               ast_channel_unlock(chan);
+
+               if (!strcasecmp(data, "secure_bridge_signaling")) {
+                       store->signaling = ast_true(value) ? 1 : 0;
+               } else if (!strcasecmp(data, "secure_bridge_media")) {
+                       store->media = ast_true(value) ? 1 : 0;
+               }
+       } else if (!ast_channel_tech(chan)->func_channel_write
+                || ast_channel_tech(chan)->func_channel_write(chan, function, data, value)) {
                ast_log(LOG_WARNING, "Unknown or unavailable item requested: '%s'\n",
                                data);
                ret = -1;
@@ -110,55 +598,138 @@ static int func_channel_write(struct ast_channel *chan, char *function,
        return ret;
 }
 
+static int func_channel_write(struct ast_channel *chan, const char *function, char *data, const char *value)
+{
+       int res;
+       ast_chan_write_info_t write_info = {
+               .version = AST_CHAN_WRITE_INFO_T_VERSION,
+               .write_fn = func_channel_write_real,
+               .chan = chan,
+               .function = function,
+               .data = data,
+               .value = value,
+       };
+
+       res = func_channel_write_real(chan, function, data, value);
+       ast_channel_setoption(chan, AST_OPTION_CHANNEL_WRITE, &write_info, sizeof(write_info), 0);
+
+       return res;
+}
+
 static struct ast_custom_function channel_function = {
        .name = "CHANNEL",
-       .synopsis = "Gets/sets various pieces of information about the channel.",
-       .syntax = "CHANNEL(item)",
-       .desc = "Gets/set various pieces of information about the channel.\n"
-               "Standard items (provided by all channel technologies) are:\n"
-               "R/O    audioreadformat         format currently being read\n"
-               "R/O    audionativeformat       format used natively for audio\n"
-               "R/O    audiowriteformat        format currently being written\n"
-               "R/W    callgroup               call groups for call pickup\n"
-               "R/O    channeltype             technology used for channel\n"
-               "R/W    language                language for sounds played\n"
-               "R/W    musicclass              class (from musiconhold.conf) for hold music\n"
-               "R/O    state                   state for channel\n"
-               "R/O    tonezone                zone for indications played\n"
-               "R/O    videonativeformat       format used natively for video\n"
-               "\n"
-               "Additional items may be available from the channel driver providing\n"
-               "the channel; see its documentation for details.\n"
-               "\n"
-               "Any item requested that is not available on the current channel will\n"
-               "return an empty string.\n",
        .read = func_channel_read,
        .write = func_channel_write,
 };
 
-static char *tdesc = "Channel information dialplan function";
-
-int unload_module(void)
+static int func_channels_read(struct ast_channel *chan, const char *function, char *data, char *buf, size_t maxlen)
 {
-       return ast_custom_function_unregister(&channel_function);
+       struct ast_channel *c = NULL;
+       regex_t re;
+       int res;
+       size_t buflen = 0;
+       struct ast_channel_iterator *iter;
+
+       buf[0] = '\0';
+
+       if (!ast_strlen_zero(data)) {
+               if ((res = regcomp(&re, data, REG_EXTENDED | REG_ICASE | REG_NOSUB))) {
+                       regerror(res, &re, buf, maxlen);
+                       ast_log(LOG_WARNING, "Error compiling regular expression for %s(%s): %s\n", function, data, buf);
+                       return -1;
+               }
+       }
+
+       if (!(iter = ast_channel_iterator_all_new())) {
+               if (!ast_strlen_zero(data)) {
+                       regfree(&re);
+               }
+               return -1;
+       }
+
+       while ((c = ast_channel_iterator_next(iter))) {
+               ast_channel_lock(c);
+               if (ast_strlen_zero(data) || regexec(&re, ast_channel_name(c), 0, NULL, 0) == 0) {
+                       size_t namelen = strlen(ast_channel_name(c));
+                       if (buflen + namelen + (ast_strlen_zero(buf) ? 0 : 1) + 1 < maxlen) {
+                               if (!ast_strlen_zero(buf)) {
+                                       strcat(buf, " ");
+                                       buflen++;
+                               }
+                               strcat(buf, ast_channel_name(c));
+                               buflen += namelen;
+                       } else {
+                               ast_log(LOG_WARNING, "Number of channels exceeds the available buffer space.  Output will be truncated!\n");
+                       }
+               }
+               ast_channel_unlock(c);
+               c = ast_channel_unref(c);
+       }
+
+       ast_channel_iterator_destroy(iter);
+
+       if (!ast_strlen_zero(data)) {
+               regfree(&re);
+       }
+
+       return 0;
 }
 
-int load_module(void)
+static struct ast_custom_function channels_function = {
+       .name = "CHANNELS",
+       .read = func_channels_read,
+};
+
+static int func_mchan_read(struct ast_channel *chan, const char *function,
+                            char *data, struct ast_str **buf, ssize_t len)
 {
-       return ast_custom_function_register(&channel_function);
+       struct ast_channel *mchan = ast_channel_get_by_name(ast_channel_linkedid(chan));
+       char *template = alloca(4 + strlen(data));
+       sprintf(template, "${%s}", data); /* SAFE */
+       ast_str_substitute_variables(buf, len, mchan ? mchan : chan, template);
+       if (mchan) {
+               ast_channel_unref(mchan);
+       }
+       return 0;
 }
 
-char *description(void)
+static int func_mchan_write(struct ast_channel *chan, const char *function,
+                             char *data, const char *value)
 {
-       return tdesc;
+       struct ast_channel *mchan = ast_channel_get_by_name(ast_channel_linkedid(chan));
+       pbx_builtin_setvar_helper(mchan ? mchan : chan, data, value);
+       if (mchan) {
+               ast_channel_unref(mchan);
+       }
+       return 0;
 }
 
-int usecount(void)
+static struct ast_custom_function mchan_function = {
+       .name = "MASTER_CHANNEL",
+       .read2 = func_mchan_read,
+       .write = func_mchan_write,
+};
+
+static int unload_module(void)
 {
-       return 0;
+       int res = 0;
+
+       res |= ast_custom_function_unregister(&channel_function);
+       res |= ast_custom_function_unregister(&channels_function);
+       res |= ast_custom_function_unregister(&mchan_function);
+
+       return res;
 }
 
-char *key()
+static int load_module(void)
 {
-       return ASTERISK_GPL_KEY;
+       int res = 0;
+
+       res |= ast_custom_function_register(&channel_function);
+       res |= ast_custom_function_register(&channels_function);
+       res |= ast_custom_function_register(&mchan_function);
+
+       return res;
 }
+
+AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Channel information dialplan functions");