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_OPENBSD) 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 #else 46 return bswap_16(x); 47 #endif 48 } 49 inline uint32 ByteSwap(uint32 x) { 50 #if defined(COMPILER_MSVC) 51 return _byteswap_ulong(x); 52 #elif defined(OS_MACOSX) 53 return OSSwapInt32(x); 54 #elif defined(OS_OPENBSD) 55 return swap32(x); 56 #else 57 return bswap_32(x); 58 #endif 59 } 60 inline uint64 ByteSwap(uint64 x) { 61 #if defined(COMPILER_MSVC) 62 return _byteswap_uint64(x); 63 #elif defined(OS_MACOSX) 64 return OSSwapInt64(x); 65 #elif defined(OS_OPENBSD) 66 return swap64(x); 67 #else 68 return bswap_64(x); 69 #endif 70 } 71 72 // Converts the bytes in |x| from host order (endianness) to little endian, and 73 // returns the result. 74 inline uint16 ByteSwapToLE16(uint16 x) { 75 #if defined(ARCH_CPU_LITTLE_ENDIAN) 76 return x; 77 #else 78 return ByteSwap(x); 79 #endif 80 } 81 inline uint32 ByteSwapToLE32(uint32 x) { 82 #if defined(ARCH_CPU_LITTLE_ENDIAN) 83 return x; 84 #else 85 return ByteSwap(x); 86 #endif 87 } 88 inline uint64 ByteSwapToLE64(uint64 x) { 89 #if defined(ARCH_CPU_LITTLE_ENDIAN) 90 return x; 91 #else 92 return ByteSwap(x); 93 #endif 94 } 95 96 // Converts the bytes in |x| from network to host order (endianness), and 97 // returns the result. 98 inline uint16 NetToHost16(uint16 x) { 99 #if defined(ARCH_CPU_LITTLE_ENDIAN) 100 return ByteSwap(x); 101 #else 102 return x; 103 #endif 104 } 105 inline uint32 NetToHost32(uint32 x) { 106 #if defined(ARCH_CPU_LITTLE_ENDIAN) 107 return ByteSwap(x); 108 #else 109 return x; 110 #endif 111 } 112 inline uint64 NetToHost64(uint64 x) { 113 #if defined(ARCH_CPU_LITTLE_ENDIAN) 114 return ByteSwap(x); 115 #else 116 return x; 117 #endif 118 } 119 120 // Converts the bytes in |x| from host to network order (endianness), and 121 // returns the result. 122 inline uint16 HostToNet16(uint16 x) { 123 #if defined(ARCH_CPU_LITTLE_ENDIAN) 124 return ByteSwap(x); 125 #else 126 return x; 127 #endif 128 } 129 inline uint32 HostToNet32(uint32 x) { 130 #if defined(ARCH_CPU_LITTLE_ENDIAN) 131 return ByteSwap(x); 132 #else 133 return x; 134 #endif 135 } 136 inline uint64 HostToNet64(uint64 x) { 137 #if defined(ARCH_CPU_LITTLE_ENDIAN) 138 return ByteSwap(x); 139 #else 140 return x; 141 #endif 142 } 143 144 } // namespace base 145 146 147 #endif // BASE_SYS_BYTEORDER_H_ 148
