/*

 *

 *  BlueZ - Bluetooth protocol stack for Linux

 *

 *  Copyright (C) 2012-2014  Intel Corporation. All rights reserved.

 *

 *

 *  This library is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Lesser General Public

 *  License as published by the Free Software Foundation; either

 *  version 2.1 of the License, or (at your option) any later version.

 *

 *  This library is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *  Lesser General Public License for more details.

 *

 *  You should have received a copy of the GNU Lesser General Public

 *  License along with this library; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 *

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <unistd.h>

#include <errno.h>

#include <sys/socket.h>

#include "src/shared/mainloop.h"

#include "src/shared/util.h"

#include "src/shared/io.h"

struct io {

	int ref_count;

	int fd;

	uint32_t events;

	bool close_on_destroy;

	io_callback_func_t read_callback;

	io_destroy_func_t read_destroy;

	void *read_data;

	io_callback_func_t write_callback;

	io_destroy_func_t write_destroy;

	void *write_data;

	io_callback_func_t disconnect_callback;

	io_destroy_func_t disconnect_destroy;

	void *disconnect_data;

};

static struct io *io_ref(struct io *io)

{

	if (!io)

		return NULL;

	__sync_fetch_and_add(&io->ref_count, 1);

	return io;

}

static void io_unref(struct io *io)

{

	if (!io)

		return;

	if (__sync_sub_and_fetch(&io->ref_count, 1))

		return;

	free(io);

}

static void io_cleanup(void *user_data)

{

	struct io *io = user_data;

	if (io->write_destroy)

		io->write_destroy(io->write_data);

	if (io->read_destroy)

		io->read_destroy(io->read_data);

	if (io->disconnect_destroy)

		io->disconnect_destroy(io->disconnect_data);

	if (io->close_on_destroy)

		close(io->fd);

	io->fd = -1;

}

static void io_callback(int fd, uint32_t events, void *user_data)

{

	struct io *io = user_data;

	io_ref(io);

	if ((events & (EPOLLRDHUP | EPOLLHUP | EPOLLERR))) {

		io->read_callback = NULL;

		io->write_callback = NULL;

		if (!io->disconnect_callback) {

			mainloop_remove_fd(io->fd);

			io_unref(io);

			return;

		}

		if (!io->disconnect_callback(io, io->disconnect_data)) {

			if (io->disconnect_destroy)

				io->disconnect_destroy(io->disconnect_data);

			io->disconnect_callback = NULL;

			io->disconnect_destroy = NULL;

			io->disconnect_data = NULL;

			io->events &= ~EPOLLRDHUP;

			mainloop_modify_fd(io->fd, io->events);

		}

	}

	if ((events & EPOLLIN) && io->read_callback) {

		if (!io->read_callback(io, io->read_data)) {

			if (io->read_destroy)

				io->read_destroy(io->read_data);

			io->read_callback = NULL;

			io->read_destroy = NULL;

			io->read_data = NULL;

			io->events &= ~EPOLLIN;

			mainloop_modify_fd(io->fd, io->events);

		}

	}

	if ((events & EPOLLOUT) && io->write_callback) {

		if (!io->write_callback(io, io->write_data)) {

			if (io->write_destroy)

				io->write_destroy(io->write_data);

			io->write_callback = NULL;

			io->write_destroy = NULL;

			io->write_data = NULL;

			io->events &= ~EPOLLOUT;

			mainloop_modify_fd(io->fd, io->events);

		}

	}

	io_unref(io);

}

struct io *io_new(int fd)

{

	struct io *io;

	if (fd < 0)

		return NULL;

	io = new0(struct io, 1);

	io->fd = fd;

	io->events = 0;

	io->close_on_destroy = false;

	if (mainloop_add_fd(io->fd, io->events, io_callback,

						io, io_cleanup) < 0) {

		free(io);

		return NULL;

	}

	return io_ref(io);

}

void io_destroy(struct io *io)

{

	if (!io)

		return;

	io->read_callback = NULL;

	io->write_callback = NULL;

	io->disconnect_callback = NULL;

	mainloop_remove_fd(io->fd);

	io_unref(io);

}

int io_get_fd(struct io *io)

{

	if (!io)

		return -ENOTCONN;

	return io->fd;

}

bool io_set_close_on_destroy(struct io *io, bool do_close)

{

	if (!io)

		return false;

	io->close_on_destroy = do_close;

	return true;

}

bool io_set_read_handler(struct io *io, io_callback_func_t callback,

				void *user_data, io_destroy_func_t destroy)

{

	uint32_t events;

	if (!io || io->fd < 0)

		return false;

	if (io->read_destroy)

		io->read_destroy(io->read_data);

	if (callback)

		events = io->events | EPOLLIN;

	else

		events = io->events & ~EPOLLIN;

	io->read_callback = callback;

	io->read_destroy = destroy;

	io->read_data = user_data;

	if (events == io->events)

		return true;

	if (mainloop_modify_fd(io->fd, events) < 0)

		return false;

	io->events = events;

	return true;

}

bool io_set_write_handler(struct io *io, io_callback_func_t callback,

				void *user_data, io_destroy_func_t destroy)

{

	uint32_t events;

	if (!io || io->fd < 0)

		return false;

	if (io->write_destroy)

		io->write_destroy(io->write_data);

	if (callback)

		events = io->events | EPOLLOUT;

	else

		events = io->events & ~EPOLLOUT;

	io->write_callback = callback;

	io->write_destroy = destroy;

	io->write_data = user_data;

	if (events == io->events)

		return true;

	if (mainloop_modify_fd(io->fd, events) < 0)

		return false;

	io->events = events;

	return true;

}

bool io_set_disconnect_handler(struct io *io, io_callback_func_t callback,

				void *user_data, io_destroy_func_t destroy)

{

	uint32_t events;

	if (!io || io->fd < 0)

		return false;

	if (io->disconnect_destroy)

		io->disconnect_destroy(io->disconnect_data);

	if (callback)

		events = io->events | EPOLLRDHUP;

	else

		events = io->events & ~EPOLLRDHUP;

	io->disconnect_callback = callback;

	io->disconnect_destroy = destroy;

	io->disconnect_data = user_data;

	if (events == io->events)

		return true;

	if (mainloop_modify_fd(io->fd, events) < 0)

		return false;

	io->events = events;

	return true;

}

ssize_t io_send(struct io *io, const struct iovec *iov, int iovcnt)

{

	ssize_t ret;

	if (!io || io->fd < 0)

		return -ENOTCONN;

	do {

		ret = writev(io->fd, iov, iovcnt);

	} while (ret < 0 && errno == EINTR);

	if (ret < 0)

		return -errno;

	return ret;

}

bool io_shutdown(struct io *io)

{

	if (!io || io->fd < 0)

		return false;

	return shutdown(io->fd, SHUT_RDWR) == 0;

}