1/* 2 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without modification, 6 * are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 19 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 21 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 24 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 25 * OF SUCH DAMAGE. 26 * 27 * This file is part of the lwIP TCP/IP stack. 28 * 29 * Author: Adam Dunkels <adam@sics.se> 30 * 31 */ 32#ifndef __LWIP_DEF_H__ 33#define __LWIP_DEF_H__ 34 35/* arch.h might define NULL already */ 36#include "lwip/arch.h" 37#include "lwip/opt.h" 38 39#ifdef __cplusplus 40extern "C" { 41#endif 42 43#define LWIP_MAX(x , y) (((x) > (y)) ? (x) : (y)) 44#define LWIP_MIN(x , y) (((x) < (y)) ? (x) : (y)) 45 46#ifndef NULL 47#define NULL ((void *)0) 48#endif 49 50/** Get the absolute difference between 2 u32_t values (correcting overflows) 51 * 'a' is expected to be 'higher' (without overflow) than 'b'. */ 52#define LWIP_U32_DIFF(a, b) (((a) >= (b)) ? ((a) - (b)) : (((a) + ((b) ^ 0xFFFFFFFF) + 1))) 53 54/* Endianess-optimized shifting of two u8_t to create one u16_t */ 55#if BYTE_ORDER == LITTLE_ENDIAN 56#define LWIP_MAKE_U16(a, b) ((a << 8) | b) 57#else 58#define LWIP_MAKE_U16(a, b) ((b << 8) | a) 59#endif 60 61#ifndef LWIP_PLATFORM_BYTESWAP 62#define LWIP_PLATFORM_BYTESWAP 0 63#endif 64 65#ifndef LWIP_PREFIX_BYTEORDER_FUNCS 66/* workaround for naming collisions on some platforms */ 67 68#ifdef htons 69#undef htons 70#endif /* htons */ 71#ifdef htonl 72#undef htonl 73#endif /* htonl */ 74#ifdef ntohs 75#undef ntohs 76#endif /* ntohs */ 77#ifdef ntohl 78#undef ntohl 79#endif /* ntohl */ 80 81#define htons(x) lwip_htons(x) 82#define ntohs(x) lwip_ntohs(x) 83#define htonl(x) lwip_htonl(x) 84#define ntohl(x) lwip_ntohl(x) 85#endif /* LWIP_PREFIX_BYTEORDER_FUNCS */ 86 87#if BYTE_ORDER == BIG_ENDIAN 88#define lwip_htons(x) (x) 89#define lwip_ntohs(x) (x) 90#define lwip_htonl(x) (x) 91#define lwip_ntohl(x) (x) 92#define PP_HTONS(x) (x) 93#define PP_NTOHS(x) (x) 94#define PP_HTONL(x) (x) 95#define PP_NTOHL(x) (x) 96#else /* BYTE_ORDER != BIG_ENDIAN */ 97#if LWIP_PLATFORM_BYTESWAP 98#define lwip_htons(x) LWIP_PLATFORM_HTONS(x) 99#define lwip_ntohs(x) LWIP_PLATFORM_HTONS(x) 100#define lwip_htonl(x) LWIP_PLATFORM_HTONL(x) 101#define lwip_ntohl(x) LWIP_PLATFORM_HTONL(x) 102#else /* LWIP_PLATFORM_BYTESWAP */ 103u16_t lwip_htons(u16_t x); 104u16_t lwip_ntohs(u16_t x); 105u32_t lwip_htonl(u32_t x); 106u32_t lwip_ntohl(u32_t x); 107#endif /* LWIP_PLATFORM_BYTESWAP */ 108 109/* These macros should be calculated by the preprocessor and are used 110 with compile-time constants only (so that there is no little-endian 111 overhead at runtime). */ 112#define PP_HTONS(x) ((((x) & 0xff) << 8) | (((x) & 0xff00) >> 8)) 113#define PP_NTOHS(x) PP_HTONS(x) 114#define PP_HTONL(x) ((((x) & 0xff) << 24) | \ 115 (((x) & 0xff00) << 8) | \ 116 (((x) & 0xff0000UL) >> 8) | \ 117 (((x) & 0xff000000UL) >> 24)) 118#define PP_NTOHL(x) PP_HTONL(x) 119 120#endif /* BYTE_ORDER == BIG_ENDIAN */ 121 122#ifdef __cplusplus 123} 124#endif 125 126#endif /* __LWIP_DEF_H__ */ 127 128