1 /*
2  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_BASE_BYTEORDER_H_
12 #define WEBRTC_BASE_BYTEORDER_H_
13 
14 #if defined(WEBRTC_POSIX) && !defined(__native_client__)
15 #include <arpa/inet.h>
16 #endif
17 
18 #if defined(WEBRTC_WIN)
19 #include <stdlib.h>
20 #endif
21 
22 #include "webrtc/base/basictypes.h"
23 
24 namespace rtc {
25 
26 // Reading and writing of little and big-endian numbers from memory
27 // TODO: Optimized versions, with direct read/writes of
28 // integers in host-endian format, when the platform supports it.
29 
Set8(void * memory,size_t offset,uint8_t v)30 inline void Set8(void* memory, size_t offset, uint8_t v) {
31   static_cast<uint8_t*>(memory)[offset] = v;
32 }
33 
Get8(const void * memory,size_t offset)34 inline uint8_t Get8(const void* memory, size_t offset) {
35   return static_cast<const uint8_t*>(memory)[offset];
36 }
37 
SetBE16(void * memory,uint16_t v)38 inline void SetBE16(void* memory, uint16_t v) {
39   Set8(memory, 0, static_cast<uint8_t>(v >> 8));
40   Set8(memory, 1, static_cast<uint8_t>(v >> 0));
41 }
42 
SetBE32(void * memory,uint32_t v)43 inline void SetBE32(void* memory, uint32_t v) {
44   Set8(memory, 0, static_cast<uint8_t>(v >> 24));
45   Set8(memory, 1, static_cast<uint8_t>(v >> 16));
46   Set8(memory, 2, static_cast<uint8_t>(v >> 8));
47   Set8(memory, 3, static_cast<uint8_t>(v >> 0));
48 }
49 
SetBE64(void * memory,uint64_t v)50 inline void SetBE64(void* memory, uint64_t v) {
51   Set8(memory, 0, static_cast<uint8_t>(v >> 56));
52   Set8(memory, 1, static_cast<uint8_t>(v >> 48));
53   Set8(memory, 2, static_cast<uint8_t>(v >> 40));
54   Set8(memory, 3, static_cast<uint8_t>(v >> 32));
55   Set8(memory, 4, static_cast<uint8_t>(v >> 24));
56   Set8(memory, 5, static_cast<uint8_t>(v >> 16));
57   Set8(memory, 6, static_cast<uint8_t>(v >> 8));
58   Set8(memory, 7, static_cast<uint8_t>(v >> 0));
59 }
60 
GetBE16(const void * memory)61 inline uint16_t GetBE16(const void* memory) {
62   return static_cast<uint16_t>((Get8(memory, 0) << 8) | (Get8(memory, 1) << 0));
63 }
64 
GetBE32(const void * memory)65 inline uint32_t GetBE32(const void* memory) {
66   return (static_cast<uint32_t>(Get8(memory, 0)) << 24) |
67          (static_cast<uint32_t>(Get8(memory, 1)) << 16) |
68          (static_cast<uint32_t>(Get8(memory, 2)) << 8) |
69          (static_cast<uint32_t>(Get8(memory, 3)) << 0);
70 }
71 
GetBE64(const void * memory)72 inline uint64_t GetBE64(const void* memory) {
73   return (static_cast<uint64_t>(Get8(memory, 0)) << 56) |
74          (static_cast<uint64_t>(Get8(memory, 1)) << 48) |
75          (static_cast<uint64_t>(Get8(memory, 2)) << 40) |
76          (static_cast<uint64_t>(Get8(memory, 3)) << 32) |
77          (static_cast<uint64_t>(Get8(memory, 4)) << 24) |
78          (static_cast<uint64_t>(Get8(memory, 5)) << 16) |
79          (static_cast<uint64_t>(Get8(memory, 6)) << 8) |
80          (static_cast<uint64_t>(Get8(memory, 7)) << 0);
81 }
82 
SetLE16(void * memory,uint16_t v)83 inline void SetLE16(void* memory, uint16_t v) {
84   Set8(memory, 0, static_cast<uint8_t>(v >> 0));
85   Set8(memory, 1, static_cast<uint8_t>(v >> 8));
86 }
87 
SetLE32(void * memory,uint32_t v)88 inline void SetLE32(void* memory, uint32_t v) {
89   Set8(memory, 0, static_cast<uint8_t>(v >> 0));
90   Set8(memory, 1, static_cast<uint8_t>(v >> 8));
91   Set8(memory, 2, static_cast<uint8_t>(v >> 16));
92   Set8(memory, 3, static_cast<uint8_t>(v >> 24));
93 }
94 
SetLE64(void * memory,uint64_t v)95 inline void SetLE64(void* memory, uint64_t v) {
96   Set8(memory, 0, static_cast<uint8_t>(v >> 0));
97   Set8(memory, 1, static_cast<uint8_t>(v >> 8));
98   Set8(memory, 2, static_cast<uint8_t>(v >> 16));
99   Set8(memory, 3, static_cast<uint8_t>(v >> 24));
100   Set8(memory, 4, static_cast<uint8_t>(v >> 32));
101   Set8(memory, 5, static_cast<uint8_t>(v >> 40));
102   Set8(memory, 6, static_cast<uint8_t>(v >> 48));
103   Set8(memory, 7, static_cast<uint8_t>(v >> 56));
104 }
105 
GetLE16(const void * memory)106 inline uint16_t GetLE16(const void* memory) {
107   return static_cast<uint16_t>((Get8(memory, 0) << 0) | (Get8(memory, 1) << 8));
108 }
109 
GetLE32(const void * memory)110 inline uint32_t GetLE32(const void* memory) {
111   return (static_cast<uint32_t>(Get8(memory, 0)) << 0) |
112          (static_cast<uint32_t>(Get8(memory, 1)) << 8) |
113          (static_cast<uint32_t>(Get8(memory, 2)) << 16) |
114          (static_cast<uint32_t>(Get8(memory, 3)) << 24);
115 }
116 
GetLE64(const void * memory)117 inline uint64_t GetLE64(const void* memory) {
118   return (static_cast<uint64_t>(Get8(memory, 0)) << 0) |
119          (static_cast<uint64_t>(Get8(memory, 1)) << 8) |
120          (static_cast<uint64_t>(Get8(memory, 2)) << 16) |
121          (static_cast<uint64_t>(Get8(memory, 3)) << 24) |
122          (static_cast<uint64_t>(Get8(memory, 4)) << 32) |
123          (static_cast<uint64_t>(Get8(memory, 5)) << 40) |
124          (static_cast<uint64_t>(Get8(memory, 6)) << 48) |
125          (static_cast<uint64_t>(Get8(memory, 7)) << 56);
126 }
127 
128 // Check if the current host is big endian.
IsHostBigEndian()129 inline bool IsHostBigEndian() {
130   static const int number = 1;
131   return 0 == *reinterpret_cast<const char*>(&number);
132 }
133 
HostToNetwork16(uint16_t n)134 inline uint16_t HostToNetwork16(uint16_t n) {
135   uint16_t result;
136   SetBE16(&result, n);
137   return result;
138 }
139 
HostToNetwork32(uint32_t n)140 inline uint32_t HostToNetwork32(uint32_t n) {
141   uint32_t result;
142   SetBE32(&result, n);
143   return result;
144 }
145 
HostToNetwork64(uint64_t n)146 inline uint64_t HostToNetwork64(uint64_t n) {
147   uint64_t result;
148   SetBE64(&result, n);
149   return result;
150 }
151 
NetworkToHost16(uint16_t n)152 inline uint16_t NetworkToHost16(uint16_t n) {
153   return GetBE16(&n);
154 }
155 
NetworkToHost32(uint32_t n)156 inline uint32_t NetworkToHost32(uint32_t n) {
157   return GetBE32(&n);
158 }
159 
NetworkToHost64(uint64_t n)160 inline uint64_t NetworkToHost64(uint64_t n) {
161   return GetBE64(&n);
162 }
163 
164 }  // namespace rtc
165 
166 #endif  // WEBRTC_BASE_BYTEORDER_H_
167