polarity.c

gistfile1.txt

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Alessandro.
 *
 * Alessandro Carminati <alessandro.carminati[at]gmail.com>
 *
 * 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 App to polarity2 reverse a DAHDI trunk
 *
 * \author Alessandro Carminati <alessandro.carminati[at]gmail.com>
 *
 * \ingroup applications
 */

/*** MODULEINFO
	<depend>dahdi</depend>
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 357721 $")

#include <dahdi/user.h>

#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/image.h"
#include "asterisk/app.h"

/* Polarity states */
#define POLARITY_IDLE   0
#define POLARITY_REV    1

/*** DOCUMENTATION
	<application name="Polarity2" language="en_US">
		<synopsis>
			Reverse polarity of a given DAHDI Trunk for a given num of ms.
		</synopsis>
		<syntax>
			<parameter name="Channel" required="true">
				<para>channel whose polarity have to be reversed.</para>
			</parameter>
			<parameter name="Duration" required="true">
				<para>Duration im ms of reversed polarity.</para>
			</parameter>
		</syntax>
		<description>
			<para>Performs a polarity reversal on a given DAHDI trunk. This can be used to
			send billing signal to old payphones.</para>
		</description>
		<see-also>
			<ref type="application">Polarity</ref>
		</see-also>
	</application>
 ***/

static char *app = "Polarity2";

static inline int dahdi_wait_event(int fd)
{
	/* Avoid the silly dahdi_waitevent which ignores a bunch of events */
	int i,j=0;
	i = DAHDI_IOMUX_SIGEVENT;
	if (ioctl(fd, DAHDI_IOMUX, &i) == -1) return -1;
	if (ioctl(fd, DAHDI_GETEVENT, &j) == -1) return -1;
	return j;
}

static int polarity2_exec(struct ast_channel *chan, const char *data)
{
	int res = -1;
	int x, mseconds;
	struct dahdi_params dahdip;
	struct ast_channel *tempchan;
	char *info, *peers;
	AST_DECLARE_APP_ARGS(args,
		AST_APP_ARG(reqchans);
		AST_APP_ARG(delay);
		);


	if (ast_strlen_zero(data)) {
		ast_log(LOG_WARNING, "Polarity2 requires two arguments (dahdi/num, milliseconds)\n");
		return -1;
		}

	info = ast_strdupa(data);

	AST_STANDARD_APP_ARGS(args, info);

	peers = args.reqchans;

	if (sscanf(args.delay, "%d", &mseconds) == 0) {
		ast_log(LOG_WARNING, "Wrong format for milliseconds\n");
		return -1;
		}

	ast_verb(3, "Polarity2 has been issued on %s for %d ms\n",peers, mseconds);

	if ((tempchan = ast_channel_get_by_name(peers))) {
		memset(&dahdip, 0, sizeof(dahdip));
		res = ioctl(ast_channel_fd(tempchan, 0), DAHDI_GET_PARAMS, &dahdip);
		ast_verb(3, "Polarity2 Begin Chan=%s : %s\n",ast_channel_name(tempchan),strerror(errno));
		if (!res) {
			if (dahdip.sigtype & __DAHDI_SIG_FXO) {
				ast_verb(3, "Polarity2 INVERT sent\n");
				x = POLARITY_REV;
				res = ioctl(ast_channel_fd(tempchan, 0), DAHDI_SETPOLARITY, &x);
				if (!res || (errno == EINPROGRESS)) {
					if (res) {
						/* Wait for the event to finish */
						dahdi_wait_event(ast_channel_fd(chan, 0));
						}
					res = ast_safe_sleep(chan, mseconds);
					ast_verb(3, "INVERTED channel %s\n", ast_channel_name(tempchan));
					} else ast_log(LOG_WARNING, "Unable to INVERT channel %s: %s\n", ast_channel_name(tempchan), strerror(errno));

				ast_verb(3,  "Polarity2 REVERT sent\n");
				x = POLARITY_IDLE;
				res = ioctl(ast_channel_fd(tempchan, 0), DAHDI_SETPOLARITY, &x);
				if (!res || (errno == EINPROGRESS)) {
					if (res) {
						/* Wait for the event to finish */
						dahdi_wait_event(ast_channel_fd(chan, 0));
						}
					res = ast_safe_sleep(chan, 500);
					ast_verb(3, "REVERTED channel %s\n", ast_channel_name(tempchan));
					} else ast_log(LOG_WARNING, "Unable to REVERT channel %s: %s\n", ast_channel_name(tempchan), strerror(errno));
			ast_verb(3, "Polarity reversed completed.\n");
			} else {
				ast_log(LOG_WARNING, "%s is not an FXS Channel\n", ast_channel_name(chan));
				return -1;
				}
		} else {
			ast_log(LOG_WARNING, "Unable to get parameters of %s: %s\n", ast_channel_name(tempchan), strerror(errno));
			return -1;
			}
		return res;
		} else {
			ast_log(LOG_WARNING, "%s is not usable\n", peers);
			return -1;
		}
}

static int unload_module(void)
{
	return ast_unregister_application(app);
}

static int load_module(void)
{
	return ast_register_application_xml(app, polarity2_exec);
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Polarity reverse channel application");