func_devstate.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007, Digium, Inc.
 *
 * Russell Bryant <russell@digium.com>
 *
 * 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 <russell@digium.com>
 *
 * \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.</para>
            <example title="Hint for extension 1234">
            same => n,NoOp(Hint for Extension 1234 is ${HINT(1234)})
            </example>
        </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,
);