/*

 *

 *  BlueZ - Bluetooth protocol stack for Linux

 *

 *  Copyright (C) 2015  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

#define _GNU_SOURCE

#include <stdio.h>

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#include <string.h>

#include <stdlib.h>

#include <stdint.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/param.h>

#include <sys/uio.h>

#include "peripheral/efivars.h"

#define SYSFS_EFIVARS "/sys/firmware/efi/efivars"

typedef struct {

    uint32_t data1;

    uint16_t data2;

    uint16_t data3;

    uint8_t  data4[8];

} efi_guid_t;

#define VENDOR_GUID \

	(efi_guid_t) { 0xd5f9d775, 0x1a09, 0x4e89, \

			{ 0x96, 0xcf, 0x1d, 0x19, 0x55, 0x4d, 0xa6, 0x67 } }

static void efivars_pathname(const char *name, char *pathname, size_t size)

{

	static efi_guid_t guid = VENDOR_GUID;

	snprintf(pathname, size - 1,

		"%s/%s-%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",

		SYSFS_EFIVARS, name, guid.data1, guid.data2, guid.data3,

		guid.data4[0], guid.data4[1], guid.data4[2], guid.data4[3],

		guid.data4[4], guid.data4[5], guid.data4[6], guid.data4[7]);

}

int efivars_read(const char *name, uint32_t *attributes,

					void *data, size_t size)

{

	char pathname[PATH_MAX];

	struct iovec iov[2];

	uint32_t attr;

	ssize_t len;

	int fd;

	efivars_pathname(name, pathname, PATH_MAX);

	fd = open(pathname, O_RDONLY | O_CLOEXEC);

	if (fd < 0)

		return -EIO;

	iov[0].iov_base = &att;;

	iov[0].iov_len = sizeof(attr);

	iov[1].iov_base = data;

	iov[1].iov_len = size;

	len = readv(fd, iov, 2);

	close(fd);

	if (len < 0)

		return -EIO;

	if (attributes)

		*attributes = attr;

	return 0;

}

int efivars_write(const char *name, uint32_t attributes,

					const void *data, size_t size)

{

	char pathname[PATH_MAX];

	void *buf;

	ssize_t written;

	int fd;

	efivars_pathname(name, pathname, PATH_MAX);

	buf = malloc(size + sizeof(attributes));

	if (!buf)

		return -ENOMEM;

	fd = open(pathname, O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC,

				S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);

	if (fd < 0) {

		free(buf);

		return -EIO;

	}

	memcpy(buf, &attributes, sizeof(attributes));

	memcpy(buf + sizeof(attributes), data, size);

	written = write(fd, buf, size + sizeof(attributes));

	close(fd);

	free(buf);

	if (written < 0)

		return -EIO;

	return 0;

}