func_devstate.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007, Digium, Inc.
 *
 * Russell Bryant <[email protected]>
 *
 * 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 Manually controlled blinky lights
 *
 * \author Russell Bryant <[email protected]>
 *
 * \ingroup functions
 *
 * \todo Delete the entry from AstDB when set to nothing like Set(DEVICE_STATE(Custom:lamp1)=)
 *
 * \note Props go out to Ahrimanes in \#asterisk for requesting this at 4:30 AM
 *       when I couldn't sleep.  :)
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/utils.h"
#include "asterisk/linkedlists.h"
#include "asterisk/devicestate.h"
#include "asterisk/cli.h"
#include "asterisk/astdb.h"
#include "asterisk/app.h"

/*** DOCUMENTATION
   <function name="DEVICE_STATE" language="en_US">
      <synopsis>
         Get or Set a device state.
      </synopsis>
      <syntax>
         <parameter name="device" required="true" />
      </syntax>
      <description>
         <para>The DEVICE_STATE function can be used to retrieve the device state from any
         device state provider. For example:</para>
         <para>NoOp(SIP/mypeer has state ${DEVICE_STATE(SIP/mypeer)})</para>
         <para>NoOp(Conference number 1234 has state ${DEVICE_STATE(MeetMe:1234)})</para>
         <para>The DEVICE_STATE function can also be used to set custom device state from
         the dialplan.  The <literal>Custom:</literal> prefix must be used. For example:</para>
         <para>Set(DEVICE_STATE(Custom:lamp1)=BUSY)</para>
         <para>Set(DEVICE_STATE(Custom:lamp2)=NOT_INUSE)</para>
         <para>You can subscribe to the status of a custom device state using a hint in
         the dialplan:</para>
         <para>exten => 1234,hint,Custom:lamp1</para>
         <para>The possible values for both uses of this function are:</para>
         <para>UNKNOWN | NOT_INUSE | INUSE | BUSY | INVALID | UNAVAILABLE | RINGING |
         RINGINUSE | ONHOLD</para>
      </description>
   </function>
   <function name="HINT" language="en_US">
      <synopsis>
         Get the devices set for a dialplan hint.
      </synopsis>
      <syntax>
         <parameter name="extension" required="true" argsep="@">
            <argument name="extension" required="true" />
            <argument name="context" />
         </parameter>
         <parameter name="options">
            <optionlist>
               <option name="n">
                  <para>Retrieve name on the hint instead of list of devices.</para>
               </option>
            </optionlist>
         </parameter>
      </syntax>
      <description>
         <para>The HINT function can be used to retrieve the list of devices that are
         mapped to a dialplan hint. For example:</para>
         <para>NoOp(Hint for Extension 1234 is ${HINT(1234)})</para>
      </description>
   </function>
 ***/


static const char astdb_family[] = "CustomDevstate";

static int devstate_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
   ast_copy_string(buf, ast_devstate_str(ast_device_state(data)), len);

   return 0;
}

static int devstate_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
{
   size_t len = strlen("Custom:");
   enum ast_device_state state_val;

   if (strncasecmp(data, "Custom:", len)) {
      ast_log(LOG_WARNING, "The DEVICE_STATE function can only be used to set 'Custom:' device state!\n");
      return -1;
   }
   data += len;
   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "DEVICE_STATE function called with no custom device name!\n");
      return -1;
   }

   state_val = ast_devstate_val(value);

   if (state_val == AST_DEVICE_UNKNOWN) {
      ast_log(LOG_ERROR, "DEVICE_STATE function given invalid state value '%s'\n", value);
      return -1;
   }

   ast_db_put(astdb_family, data, value);

   ast_devstate_changed(state_val, AST_DEVSTATE_CACHABLE, "Custom:%s", data);

   return 0;
}

enum {
   HINT_OPT_NAME = (1 << 0),
};

AST_APP_OPTIONS(hint_options, BEGIN_OPTIONS
   AST_APP_OPTION('n', HINT_OPT_NAME),
END_OPTIONS );

static int hint_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
   char *exten, *context;
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(exten);
      AST_APP_ARG(options);
   );
   struct ast_flags opts = { 0, };
   int res;

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "The HINT function requires an extension\n");
      return -1;
   }

   AST_STANDARD_APP_ARGS(args, data);

   if (ast_strlen_zero(args.exten)) {
      ast_log(LOG_WARNING, "The HINT function requires an extension\n");
      return -1;
   }

   context = exten = args.exten;
   strsep(&context, "@");
   if (ast_strlen_zero(context))
      context = "default";

   if (!ast_strlen_zero(args.options))
      ast_app_parse_options(hint_options, &opts, NULL, args.options);

   if (ast_test_flag(&opts, HINT_OPT_NAME))
      res = ast_get_hint(NULL, 0, buf, len, chan, context, exten);
   else
      res = ast_get_hint(buf, len, NULL, 0, chan, context, exten);

   return !res; /* ast_get_hint returns non-zero on success */
}

static enum ast_device_state custom_devstate_callback(const char *data)
{
   char buf[256] = "";

   /* Ignore check_return warning from Coverity fow ast_db_get below */
   ast_db_get(astdb_family, data, buf, sizeof(buf));

   return ast_devstate_val(buf);
}

static char *handle_cli_devstate_list(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct ast_db_entry *db_entry, *db_tree;

   switch (cmd) {
   case CLI_INIT:
      e->command = "devstate list";
      e->usage =
         "Usage: devstate list\n"
         "       List all custom device states that have been set by using\n"
         "       the DEVICE_STATE dialplan function.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != e->args)
      return CLI_SHOWUSAGE;

   ast_cli(a->fd, "\n"
           "---------------------------------------------------------------------\n"
           "--- Custom Device States --------------------------------------------\n"
           "---------------------------------------------------------------------\n"
           "---\n");

   db_entry = db_tree = ast_db_gettree(astdb_family, NULL);
   for (; db_entry; db_entry = db_entry->next) {
      const char *dev_name = strrchr(db_entry->key, '/') + 1;
      if (dev_name <= (const char *) 1)
         continue;
      ast_cli(a->fd, "--- Name: 'Custom:%s'  State: '%s'\n"
                     "---\n", dev_name, db_entry->data);
   }
   ast_db_freetree(db_tree);
   db_tree = NULL;

   ast_cli(a->fd,
           "---------------------------------------------------------------------\n"
           "---------------------------------------------------------------------\n"
           "\n");

   return CLI_SUCCESS;
}

static char *handle_cli_devstate_change(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
    size_t len;
   const char *dev, *state;
   enum ast_device_state state_val;

   switch (cmd) {
   case CLI_INIT:
      e->command = "devstate change";
      e->usage =
         "Usage: devstate change <device> <state>\n"
         "       Change a custom device to a new state.\n"
         "       The possible values for the state are:\n"
         "UNKNOWN | NOT_INUSE | INUSE | BUSY | INVALID | UNAVAILABLE | RINGING\n"
         "RINGINUSE | ONHOLD\n"
         "\n"
         "Examples:\n"
         "       devstate change Custom:mystate1 INUSE\n"
         "       devstate change Custom:mystate1 NOT_INUSE\n"
         "       \n";
      return NULL;
   case CLI_GENERATE:
   {
      static const char * const cmds[] = { "UNKNOWN", "NOT_INUSE", "INUSE", "BUSY",
                       "UNAVAILABLE", "RINGING", "RINGINUSE", "ONHOLD", NULL };

      if (a->pos == e->args + 1)
         return ast_cli_complete(a->word, cmds, a->n);

      return NULL;
   }
   }

   if (a->argc != e->args + 2)
      return CLI_SHOWUSAGE;

   len = strlen("Custom:");
   dev = a->argv[e->args];
   state = a->argv[e->args + 1];

   if (strncasecmp(dev, "Custom:", len)) {
      ast_cli(a->fd, "The devstate command can only be used to set 'Custom:' device state!\n");
      return CLI_FAILURE;
   }

   dev += len;
   if (ast_strlen_zero(dev))
      return CLI_SHOWUSAGE;

   state_val = ast_devstate_val(state);

   if (state_val == AST_DEVICE_UNKNOWN)
      return CLI_SHOWUSAGE;

   ast_cli(a->fd, "Changing %s to %s\n", dev, state);

   ast_db_put(astdb_family, dev, state);

   ast_devstate_changed(state_val, AST_DEVSTATE_CACHABLE, "Custom:%s", dev);

   return CLI_SUCCESS;
}

static struct ast_cli_entry cli_funcdevstate[] = {
   AST_CLI_DEFINE(handle_cli_devstate_list, "List currently known custom device states"),
   AST_CLI_DEFINE(handle_cli_devstate_change, "Change a custom device state"),
};

static struct ast_custom_function devstate_function = {
   .name = "DEVICE_STATE",
   .read = devstate_read,
   .write = devstate_write,
};

static struct ast_custom_function hint_function = {
   .name = "HINT",
   .read = hint_read,
};

static int unload_module(void)
{
   int res = 0;

   res |= ast_custom_function_unregister(&devstate_function);
   res |= ast_custom_function_unregister(&hint_function);
   res |= ast_devstate_prov_del("Custom");
   res |= ast_cli_unregister_multiple(cli_funcdevstate, ARRAY_LEN(cli_funcdevstate));

   return res;
}

static int load_module(void)
{
   int res = 0;
   struct ast_db_entry *db_entry, *db_tree;

   /* Populate the device state cache on the system with all of the currently
    * known custom device states. */
   db_entry = db_tree = ast_db_gettree(astdb_family, NULL);
   for (; db_entry; db_entry = db_entry->next) {
      const char *dev_name = strrchr(db_entry->key, '/') + 1;
      if (dev_name <= (const char *) 1)
         continue;
      ast_devstate_changed(ast_devstate_val(db_entry->data),
         AST_DEVSTATE_CACHABLE, "Custom:%s", dev_name);
   }
   ast_db_freetree(db_tree);
   db_tree = NULL;

   res |= ast_custom_function_register(&devstate_function);
   res |= ast_custom_function_register(&hint_function);
   res |= ast_devstate_prov_add("Custom", custom_devstate_callback);
   res |= ast_cli_register_multiple(cli_funcdevstate, ARRAY_LEN(cli_funcdevstate));

   return res;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Gets or sets a device state in the dialplan",
   .support_level = AST_MODULE_SUPPORT_CORE,
   .load = load_module,
   .unload = unload_module,
   .load_pri = AST_MODPRI_DEVSTATE_PROVIDER,
);