/*

 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.

 * 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.

 * 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 BY THE AUTHOR ``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.

 *

 * This file is part of the lwIP TCP/IP stack.

 * 

 * Author: Adam Dunkels <adam@sics.se>

 *

 */

#ifndef __LWIP_DEF_H__

#define __LWIP_DEF_H__

/* arch.h might define NULL already */

#include "vma/lwip/opt.h"

#ifdef __cplusplus

extern "C" {

#endif

#define LWIP_MAX(x , y)  (((x) > (y)) ? (x) : (y))

#define LWIP_MIN(x , y)  (((x) < (y)) ? (x) : (y))

#ifndef NULL

#define NULL ((void *)0)

#endif

/** Get the absolute difference between 2 u32_t values (correcting overflows)

 * 'a' is expected to be 'higher' (without overflow) than 'b'. */

#define LWIP_U32_DIFF(a, b) (((a) >= (b)) ? ((a) - (b)) : (((a) + ((b) ^ 0xFFFFFFFF) + 1))) 

/* Endianess-optimized shifting of two u8_t to create one u16_t */

#if BYTE_ORDER == LITTLE_ENDIAN

#define LWIP_MAKE_U16(a, b) ((a << 8) | b)

#else

#define LWIP_MAKE_U16(a, b) ((b << 8) | a)

#endif 

#ifndef LWIP_PLATFORM_BYTESWAP

#define LWIP_PLATFORM_BYTESWAP 0

#endif

#ifndef LWIP_PREFIX_BYTEORDER_FUNCS

/* workaround for naming collisions on some platforms */

#ifdef htons

#undef htons

#endif /* htons */

#ifdef htonl

#undef htonl

#endif /* htonl */

#ifdef ntohs

#undef ntohs

#endif /* ntohs */

#ifdef ntohl

#undef ntohl

#endif /* ntohl */

#define htons(x) lwip_htons(x)

#define ntohs(x) lwip_ntohs(x)

#define htonl(x) lwip_htonl(x)

#define ntohl(x) lwip_ntohl(x)

#endif /* LWIP_PREFIX_BYTEORDER_FUNCS */

#if BYTE_ORDER == BIG_ENDIAN

#define lwip_htons(x) (x)

#define lwip_ntohs(x) (x)

#define lwip_htonl(x) (x)

#define lwip_ntohl(x) (x)

#define PP_HTONS(x) (x)

#define PP_NTOHS(x) (x)

#define PP_HTONL(x) (x)

#define PP_NTOHL(x) (x)

#else /* BYTE_ORDER != BIG_ENDIAN */

#if LWIP_PLATFORM_BYTESWAP

#define lwip_htons(x) LWIP_PLATFORM_HTONS(x)

#define lwip_ntohs(x) LWIP_PLATFORM_HTONS(x)

#define lwip_htonl(x) LWIP_PLATFORM_HTONL(x)

#define lwip_ntohl(x) LWIP_PLATFORM_HTONL(x)

#else /* LWIP_PLATFORM_BYTESWAP */

u16_t lwip_htons(u16_t x);

u16_t lwip_ntohs(u16_t x);

u32_t lwip_htonl(u32_t x);

u32_t lwip_ntohl(u32_t x);

#endif /* LWIP_PLATFORM_BYTESWAP */

/* These macros should be calculated by the preprocessor and are used

   with compile-time constants only (so that there is no little-endian

   overhead at runtime). */

#define PP_HTONS(x) ((((x) & 0xff) << 8) | (((x) & 0xff00) >> 8))

#define PP_NTOHS(x) PP_HTONS(x)

#define PP_HTONL(x) ((((x) & 0xff) << 24) | \

                     (((x) & 0xff00) << 8) | \

                     (((x) & 0xff0000UL) >> 8) | \

                     (((x) & 0xff000000UL) >> 24))

#define PP_NTOHL(x) PP_HTONL(x)

#endif /* BYTE_ORDER == BIG_ENDIAN */

#ifdef __cplusplus

}

#endif

#endif /* __LWIP_DEF_H__ */