// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // This header defines cross-platform ByteSwap() implementations for 16, 32 and // 64-bit values, and NetToHostXX() / HostToNextXX() functions equivalent to // the traditional ntohX() and htonX() functions. // Use the functions defined here rather than using the platform-specific // functions directly. #ifndef BASE_SYS_BYTEORDER_H_ #define BASE_SYS_BYTEORDER_H_ #include "base/basictypes.h" #include "base/build_config.h" #if defined(OS_WIN) #include <winsock2.h> #else #include <arpa/inet.h> #endif namespace base { #if defined(COMPILER_MSVC) #include <stdlib.h> inline uint16_t ByteSwap(uint16_t x) { return _byteswap_ushort(x); } inline uint32_t ByteSwap(uint32_t x) { return _byteswap_ulong(x); } inline uint64_t ByteSwap(uint64_t x) { return _byteswap_uint64(x); } #elif defined(OS_MACOSX) // Mac OS X / Darwin features #include <libkern/OSByteOrder.h> inline uint16_t ByteSwap(uint16_t x) { return OSSwapInt16(x); } inline uint32_t ByteSwap(uint32_t x) { return OSSwapInt32(x); } inline uint64_t ByteSwap(uint64_t x) { return OSSwapInt64(x); } #elif defined(OS_LINUX) #include <byteswap.h> inline uint16_t ByteSwap(uint16_t x) { return bswap_16(x); } inline uint32_t ByteSwap(uint32_t x) { return bswap_32(x); } inline uint64_t ByteSwap(uint64_t x) { return bswap_64(x); } #else // Returns a value with all bytes in |x| swapped, i.e. reverses the endianness. inline uint16_t ByteSwap(uint16_t x) { return (x << 8) | (x >> 8); } inline uint32_t ByteSwap(uint32_t x) { x = ((x & 0xff00ff00UL) >> 8) | ((x & 0x00ff00ffUL) << 8); return (x >> 16) | (x << 16); } inline uint64_t ByteSwap(uint64_t x) { x = ((x & 0xff00ff00ff00ff00ULL) >> 8) | ((x & 0x00ff00ff00ff00ffULL) << 8); x = ((x & 0xffff0000ffff0000ULL) >> 16) | ((x & 0x0000ffff0000ffffULL) << 16); return (x >> 32) | (x << 32); } #endif // Converts the bytes in |x| from host order (endianness) to little endian, and // returns the result. inline uint16_t ByteSwapToLE16(uint16_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return x; #else return ByteSwap(x); #endif } inline uint32_t ByteSwapToLE32(uint32_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return x; #else return ByteSwap(x); #endif } inline uint64_t ByteSwapToLE64(uint64_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return x; #else return ByteSwap(x); #endif } // Converts the bytes in |x| from network to host order (endianness), and // returns the result. inline uint16_t NetToHost16(uint16_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return ByteSwap(x); #else return x; #endif } inline uint32_t NetToHost32(uint32_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return ByteSwap(x); #else return x; #endif } inline uint64_t NetToHost64(uint64_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return ByteSwap(x); #else return x; #endif } // Converts the bytes in |x| from host to network order (endianness), and // returns the result. inline uint16_t HostToNet16(uint16_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return ByteSwap(x); #else return x; #endif } inline uint32_t HostToNet32(uint32_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return ByteSwap(x); #else return x; #endif } inline uint64_t HostToNet64(uint64_t x) { #if defined(ARCH_CPU_LITTLE_ENDIAN) return ByteSwap(x); #else return x; #endif } } // namespace base #endif // BASE_SYS_BYTEORDER_H_