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 40 extern "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 */ 103 u16_t lwip_htons(u16_t x); 104 u16_t lwip_ntohs(u16_t x); 105 u32_t lwip_htonl(u32_t x); 106 u32_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