1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // This header defines cross-platform ByteSwap() implementations for 16, 32 and 6 // 64-bit values, and NetToHostXX() / HostToNextXX() functions equivalent to 7 // the traditional ntohX() and htonX() functions. 8 // Use the functions defined here rather than using the platform-specific 9 // functions directly. 10 11 #ifndef BASE_SYS_BYTEORDER_H_ 12 #define BASE_SYS_BYTEORDER_H_ 13 14 #include "base/basictypes.h" 15 #include "build/build_config.h" 16 17 #if defined(OS_WIN) 18 #include <winsock2.h> 19 #else 20 #include <arpa/inet.h> 21 #endif 22 23 // Include headers to provide byteswap for all platforms. 24 #if defined(COMPILER_MSVC) 25 #include <stdlib.h> 26 #elif defined(OS_MACOSX) 27 #include <libkern/OSByteOrder.h> 28 #elif defined(OS_BSD) 29 #include <sys/endian.h> 30 #else 31 #include <byteswap.h> 32 #endif 33 34 35 namespace base { 36 37 // Returns a value with all bytes in |x| swapped, i.e. reverses the endianness. 38 inline uint16 ByteSwap(uint16 x) { 39 #if defined(COMPILER_MSVC) 40 return _byteswap_ushort(x); 41 #elif defined(OS_MACOSX) 42 return OSSwapInt16(x); 43 #elif defined(OS_OPENBSD) 44 return swap16(x); 45 #elif defined(OS_FREEBSD) 46 return bswap16(x); 47 #else 48 return bswap_16(x); 49 #endif 50 } 51 inline uint32 ByteSwap(uint32 x) { 52 #if defined(COMPILER_MSVC) 53 return _byteswap_ulong(x); 54 #elif defined(OS_MACOSX) 55 return OSSwapInt32(x); 56 #elif defined(OS_OPENBSD) 57 return swap32(x); 58 #elif defined(OS_FREEBSD) 59 return bswap32(x); 60 #else 61 return bswap_32(x); 62 #endif 63 } 64 inline uint64 ByteSwap(uint64 x) { 65 #if defined(COMPILER_MSVC) 66 return _byteswap_uint64(x); 67 #elif defined(OS_MACOSX) 68 return OSSwapInt64(x); 69 #elif defined(OS_OPENBSD) 70 return swap64(x); 71 #elif defined(OS_FREEBSD) 72 return bswap64(x); 73 #else 74 return bswap_64(x); 75 #endif 76 } 77 78 // Converts the bytes in |x| from host order (endianness) to little endian, and 79 // returns the result. 80 inline uint16 ByteSwapToLE16(uint16 x) { 81 #if defined(ARCH_CPU_LITTLE_ENDIAN) 82 return x; 83 #else 84 return ByteSwap(x); 85 #endif 86 } 87 inline uint32 ByteSwapToLE32(uint32 x) { 88 #if defined(ARCH_CPU_LITTLE_ENDIAN) 89 return x; 90 #else 91 return ByteSwap(x); 92 #endif 93 } 94 inline uint64 ByteSwapToLE64(uint64 x) { 95 #if defined(ARCH_CPU_LITTLE_ENDIAN) 96 return x; 97 #else 98 return ByteSwap(x); 99 #endif 100 } 101 102 // Converts the bytes in |x| from network to host order (endianness), and 103 // returns the result. 104 inline uint16 NetToHost16(uint16 x) { 105 #if defined(ARCH_CPU_LITTLE_ENDIAN) 106 return ByteSwap(x); 107 #else 108 return x; 109 #endif 110 } 111 inline uint32 NetToHost32(uint32 x) { 112 #if defined(ARCH_CPU_LITTLE_ENDIAN) 113 return ByteSwap(x); 114 #else 115 return x; 116 #endif 117 } 118 inline uint64 NetToHost64(uint64 x) { 119 #if defined(ARCH_CPU_LITTLE_ENDIAN) 120 return ByteSwap(x); 121 #else 122 return x; 123 #endif 124 } 125 126 // Converts the bytes in |x| from host to network order (endianness), and 127 // returns the result. 128 inline uint16 HostToNet16(uint16 x) { 129 #if defined(ARCH_CPU_LITTLE_ENDIAN) 130 return ByteSwap(x); 131 #else 132 return x; 133 #endif 134 } 135 inline uint32 HostToNet32(uint32 x) { 136 #if defined(ARCH_CPU_LITTLE_ENDIAN) 137 return ByteSwap(x); 138 #else 139 return x; 140 #endif 141 } 142 inline uint64 HostToNet64(uint64 x) { 143 #if defined(ARCH_CPU_LITTLE_ENDIAN) 144 return ByteSwap(x); 145 #else 146 return x; 147 #endif 148 } 149 150 } // namespace base 151 152 153 #endif // BASE_SYS_BYTEORDER_H_ 154
