1#ifndef AWS_COMMON_BYTE_ORDER_INL
2#define AWS_COMMON_BYTE_ORDER_INL
3
4/*
5 * Copyright 2010-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License").
8 * You may not use this file except in compliance with the License.
9 * A copy of the License is located at
10 *
11 * http://aws.amazon.com/apache2.0
12 *
13 * or in the "license" file accompanying this file. This file is distributed
14 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
15 * express or implied. See the License for the specific language governing
16 * permissions and limitations under the License.
17 */
18
19#include <aws/common/byte_order.h>
20#include <aws/common/common.h>
21
22#ifdef _MSC_VER
23# include <stdlib.h>
24#else
25# include <netinet/in.h>
26#endif /* _MSC_VER */
27
28AWS_EXTERN_C_BEGIN
29
30/**
31 * Returns 1 if machine is big endian, 0 if little endian.
32 * If you compile with even -O1 optimization, this check is completely optimized
33 * out at compile time and code which calls "if (aws_is_big_endian())" will do
34 * the right thing without branching.
35 */
36AWS_STATIC_IMPL int aws_is_big_endian(void) {
37 const uint16_t z = 0x100;
38 return *(const uint8_t *)&z;
39}
40
41/**
42 * Convert 64 bit integer from host to network byte order.
43 */
44AWS_STATIC_IMPL uint64_t aws_hton64(uint64_t x) {
45 if (aws_is_big_endian()) {
46 return x;
47 }
48#if defined(__x86_64__) && (defined(__GNUC__) || defined(__clang__)) && !defined(CBMC)
49 uint64_t v;
50 __asm__("bswap %q0" : "=r"(v) : "0"(x));
51 return v;
52#elif defined(_MSC_VER)
53 return _byteswap_uint64(x);
54#else
55 uint32_t low = (uint32_t)x;
56 uint32_t high = (uint32_t)(x >> 32);
57 return ((uint64_t)htonl(low)) << 32 | htonl(high);
58#endif
59}
60
61/**
62 * Convert 64 bit integer from network to host byte order.
63 */
64AWS_STATIC_IMPL uint64_t aws_ntoh64(uint64_t x) {
65 return aws_hton64(x);
66}
67
68/**
69 * Convert 32 bit integer from host to network byte order.
70 */
71AWS_STATIC_IMPL uint32_t aws_hton32(uint32_t x) {
72#ifdef _MSC_VER
73 return aws_is_big_endian() ? x : _byteswap_ulong(x);
74#else
75 return htonl(x);
76#endif
77}
78
79/**
80 * Convert 32 bit float from host to network byte order.
81 */
82AWS_STATIC_IMPL float aws_htonf32(float x) {
83 if (aws_is_big_endian()) {
84 return x;
85 }
86
87 uint8_t *f_storage = (uint8_t *)&x;
88
89 float ret_value;
90 uint8_t *ret_storage = (uint8_t *)&ret_value;
91
92 ret_storage[0] = f_storage[3];
93 ret_storage[1] = f_storage[2];
94 ret_storage[2] = f_storage[1];
95 ret_storage[3] = f_storage[0];
96
97 return ret_value;
98}
99
100/**
101 * Convert 64 bit double from host to network byte order.
102 */
103AWS_STATIC_IMPL double aws_htonf64(double x) {
104 if (aws_is_big_endian()) {
105 return x;
106 }
107
108 uint8_t *f_storage = (uint8_t *)&x;
109
110 double ret_value;
111 uint8_t *ret_storage = (uint8_t *)&ret_value;
112
113 ret_storage[0] = f_storage[7];
114 ret_storage[1] = f_storage[6];
115 ret_storage[2] = f_storage[5];
116 ret_storage[3] = f_storage[4];
117 ret_storage[4] = f_storage[3];
118 ret_storage[5] = f_storage[2];
119 ret_storage[6] = f_storage[1];
120 ret_storage[7] = f_storage[0];
121
122 return ret_value;
123}
124
125/**
126 * Convert 32 bit integer from network to host byte order.
127 */
128AWS_STATIC_IMPL uint32_t aws_ntoh32(uint32_t x) {
129#ifdef _MSC_VER
130 return aws_is_big_endian() ? x : _byteswap_ulong(x);
131#else
132 return ntohl(x);
133#endif
134}
135
136/**
137 * Convert 32 bit float from network to host byte order.
138 */
139AWS_STATIC_IMPL float aws_ntohf32(float x) {
140 return aws_htonf32(x);
141}
142
143/**
144 * Convert 32 bit float from network to host byte order.
145 */
146AWS_STATIC_IMPL double aws_ntohf64(double x) {
147 return aws_htonf64(x);
148}
149
150/**
151 * Convert 24 bit integer from host to network byte order.
152 */
153AWS_STATIC_IMPL uint32_t aws_hton24(uint32_t x) {
154 AWS_PRECONDITION(x <= 0xFFFFFF, "Input [x] must be representable with at most 3 bytes.");
155 if (aws_is_big_endian()) {
156 return x;
157 } else {
158 return aws_hton32(x) >> 8;
159 }
160}
161
162/**
163 * Convert 24 bit integer from network to host byte order.
164 */
165AWS_STATIC_IMPL uint32_t aws_ntoh24(uint32_t x) {
166 AWS_PRECONDITION((x) <= 0xFFFFFFF, "Input [x] must be representable with at most 3 bytes.");
167 if (aws_is_big_endian()) {
168 return x;
169 } else {
170 return aws_ntoh32(x) >> 8;
171 }
172}
173
174/**
175 * Convert 16 bit integer from host to network byte order.
176 */
177AWS_STATIC_IMPL uint16_t aws_hton16(uint16_t x) {
178#ifdef _MSC_VER
179 return aws_is_big_endian() ? x : _byteswap_ushort(x);
180#else
181 return htons(x);
182#endif
183}
184
185/**
186 * Convert 16 bit integer from network to host byte order.
187 */
188AWS_STATIC_IMPL uint16_t aws_ntoh16(uint16_t x) {
189#ifdef _MSC_VER
190 return aws_is_big_endian() ? x : _byteswap_ushort(x);
191#else
192 return ntohs(x);
193#endif
194}
195
196AWS_EXTERN_C_END
197
198#endif /* AWS_COMMON_BYTE_ORDER_INL */
199