libbsd/include/bsd/sys/endian.h

/*
 * Copyright © 2011 Guillem Jover
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifdef LIBBSD_OVERLAY
#include_next <endian.h>
#else
#include <endian.h>
#endif

#ifndef LIBBSD_SYS_ENDIAN_H
#define LIBBSD_SYS_ENDIAN_H

#ifndef _BYTE_ORDER
#define _BYTE_ORDER __BYTE_ORDER
#endif

#ifndef _LITTLE_ENDIAN
#define _LITTLE_ENDIAN __LITTLE_ENDIAN
#endif

#ifndef _BIG_ENDIAN
#define _BIG_ENDIAN __BIG_ENDIAN
#endif

#ifndef _PDP_ENDIAN
#define _PDP_ENDIAN __PDP_ENDIAN
#endif

/*
 * Copyright © 2002 Thomas Moestl <tmm@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stdint.h>

/* Alignment-agnostic encode/decode bytestream to/from little/big endian. */

static __inline uint16_t
be16dec(const void *pp)
{
	uint8_t const *p = (uint8_t const *)pp;

	return ((p[0] << 8) | p[1]);
}

static __inline uint32_t
be32dec(const void *pp)
{
	uint8_t const *p = (uint8_t const *)pp;

	return (((unsigned)p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]);
}

static __inline uint64_t
be64dec(const void *pp)
{
	uint8_t const *p = (uint8_t const *)pp;

	return (((uint64_t)be32dec(p) << 32) | be32dec(p + 4));
}

static __inline uint16_t
le16dec(const void *pp)
{
	uint8_t const *p = (uint8_t const *)pp;

	return ((p[1] << 8) | p[0]);
}

static __inline uint32_t
le32dec(const void *pp)
{
	uint8_t const *p = (uint8_t const *)pp;

	return (((unsigned)p[3] << 24) | (p[2] << 16) | (p[1] << 8) | p[0]);
}

static __inline uint64_t
le64dec(const void *pp)
{
	uint8_t const *p = (uint8_t const *)pp;

	return (((uint64_t)le32dec(p + 4) << 32) | le32dec(p));
}

static __inline void
be16enc(void *pp, uint16_t u)
{
	uint8_t *p = (uint8_t *)pp;

	p[0] = (u >> 8) & 0xff;
	p[1] = u & 0xff;
}

static __inline void
be32enc(void *pp, uint32_t u)
{
	uint8_t *p = (uint8_t *)pp;

	p[0] = (u >> 24) & 0xff;
	p[1] = (u >> 16) & 0xff;
	p[2] = (u >> 8) & 0xff;
	p[3] = u & 0xff;
}

static __inline void
be64enc(void *pp, uint64_t u)
{
	uint8_t *p = (uint8_t *)pp;

	be32enc(p, (uint32_t)(u >> 32));
	be32enc(p + 4, (uint32_t)(u & 0xffffffffU));
}

static __inline void
le16enc(void *pp, uint16_t u)
{
	uint8_t *p = (uint8_t *)pp;

	p[0] = u & 0xff;
	p[1] = (u >> 8) & 0xff;
}

static __inline void
le32enc(void *pp, uint32_t u)
{
	uint8_t *p = (uint8_t *)pp;

	p[0] = u & 0xff;
	p[1] = (u >> 8) & 0xff;
	p[2] = (u >> 16) & 0xff;
	p[3] = (u >> 24) & 0xff;
}

static __inline void
le64enc(void *pp, uint64_t u)
{
	uint8_t *p = (uint8_t *)pp;

	le32enc(p, (uint32_t)(u & 0xffffffffU));
	le32enc(p + 4, (uint32_t)(u >> 32));
}

#endif