func_channel.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2006, Digium, Inc.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Channel info dialplan functions
 *
 * \author Kevin P. Fleming <kpfleming@digium.com>
 * \author Ben Winslow
 * 
 * \ingroup functions
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 314205 $")

#include <regex.h>

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/utils.h"
#include "asterisk/app.h"
#include "asterisk/indications.h"
#include "asterisk/stringfields.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="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="channeltype">
                  <para>R/O technology used for channel.</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="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="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>
         </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_channel_lock(chan); \
      ast_copy_string(dest, source, len); \
      ast_channel_unlock(chan); \
   } while (0)
#define locked_string_field_set(chan, field, source) \
   do { \
      ast_channel_lock(chan); \
      ast_string_field_set(chan, field, source); \
      ast_channel_unlock(chan); \
   } while (0)

char *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;

   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);
#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") && chan->zone)
      locked_copy_string(chan, buf, chan->zone->country, len);
   else if (!strcasecmp(data, "language"))
      locked_copy_string(chan, buf, chan->language, len);
   else if (!strcasecmp(data, "musicclass"))
      locked_copy_string(chan, buf, chan->musicclass, len);
   else if (!strcasecmp(data, "parkinglot"))
      locked_copy_string(chan, buf, chan->parkinglot, len);
   else if (!strcasecmp(data, "state"))
      locked_copy_string(chan, buf, ast_state2str(chan->_state), len);
   else if (!strcasecmp(data, "channeltype"))
      locked_copy_string(chan, buf, chan->tech->type, len);
   else if (!strcasecmp(data, "transfercapability"))
      locked_copy_string(chan, buf, transfercapability_table[chan->transfercapability & 0x1f], len);
   else if (!strcasecmp(data, "callgroup")) {
      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)) {
      ast_log(LOG_WARNING, "Unknown or unavailable item requested: '%s'\n", data);
      ret = -1;
   }

   return ret;
}

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);
#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).");
      }
      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 (chan->zone) {
            chan->zone = ast_tone_zone_unref(chan->zone);
         }
         chan->zone = ast_tone_zone_ref(new_zone);
         ast_channel_unlock(chan);
         new_zone = ast_tone_zone_unref(new_zone);
      }
   } else if (!strcasecmp(data, "callgroup"))
      chan->callgroup = 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")) {
            chan->transfercapability = i;
            break;
         }
      }
   } else if (!chan->tech->func_channel_write
       || chan->tech->func_channel_write(chan, function, data, value)) {
      ast_log(LOG_WARNING, "Unknown or unavailable item requested: '%s'\n",
            data);
      ret = -1;
   }

   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",
   .read = func_channel_read,
   .write = func_channel_write,
};

static int func_channels_read(struct ast_channel *chan, const char *function, char *data, char *buf, size_t maxlen)
{
   struct ast_channel *c = NULL;
   regex_t re;
   int res;
   size_t buflen = 0;
   
   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;
      }
   }

   for (c = ast_channel_walk_locked(NULL); c; ast_channel_unlock(c), c = ast_channel_walk_locked(c)) {
      if (ast_strlen_zero(data) || regexec(&re, c->name, 0, NULL, 0) == 0) {
         size_t namelen = strlen(c->name);
         if (buflen + namelen + (ast_strlen_zero(buf) ? 0 : 1) + 1 < maxlen) {
            if (!ast_strlen_zero(buf)) {
               strcat(buf, " ");
               buflen++;
            }
            strcat(buf, c->name);
            buflen += namelen;
         } else {
            ast_log(LOG_WARNING, "Number of channels exceeds the available buffer space.  Output will be truncated!\n");
         }
      }
   }

   if (!ast_strlen_zero(data)) {
      regfree(&re);
   }

   return 0;
}

static struct ast_custom_function channels_function = {
   .name = "CHANNELS",
   .read = func_channels_read,
};

static int unload_module(void)
{
   int res = 0;
   
   res |= ast_custom_function_unregister(&channel_function);
   res |= ast_custom_function_unregister(&channels_function);
   
   return res;
}

static int load_module(void)
{
   int res = 0;
   
   res |= ast_custom_function_register(&channel_function);
   res |= ast_custom_function_register(&channels_function);
   
   return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Channel information dialplan functions");