1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
9  *
10  * This software is licensed as described in the file COPYING, which
11  * you should have received as part of this distribution. The terms
12  * are also available at https://curl.haxx.se/docs/copyright.html.
13  *
14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15  * copies of the Software, and permit persons to whom the Software is
16  * furnished to do so, under the terms of the COPYING file.
17  *
18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19  * KIND, either express or implied.
20  *
21  ***************************************************************************/
22 
23 #include "curl_setup.h"
24 
25 #include "curl_endian.h"
26 
27 /*
28  * Curl_read16_le()
29  *
30  * This function converts a 16-bit integer from the little endian format, as
31  * used in the incoming package to whatever endian format we're using
32  * natively.
33  *
34  * Parameters:
35  *
36  * buf      [in]     - A pointer to a 2 byte buffer.
37  *
38  * Returns the integer.
39  */
40 unsigned short Curl_read16_le(const unsigned char *buf)
41 {
42   return (unsigned short)(((unsigned short)buf[0]) |
43                           ((unsigned short)buf[1] << 8));
44 }
45 
46 /*
47  * Curl_read32_le()
48  *
49  * This function converts a 32-bit integer from the little endian format, as
50  * used in the incoming package to whatever endian format we're using
51  * natively.
52  *
53  * Parameters:
54  *
55  * buf      [in]     - A pointer to a 4 byte buffer.
56  *
57  * Returns the integer.
58  */
59 unsigned int Curl_read32_le(const unsigned char *buf)
60 {
61   return ((unsigned int)buf[0]) | ((unsigned int)buf[1] << 8) |
62          ((unsigned int)buf[2] << 16) | ((unsigned int)buf[3] << 24);
63 }
64 
65 /*
66  * Curl_read16_be()
67  *
68  * This function converts a 16-bit integer from the big endian format, as
69  * used in the incoming package to whatever endian format we're using
70  * natively.
71  *
72  * Parameters:
73  *
74  * buf      [in]     - A pointer to a 2 byte buffer.
75  *
76  * Returns the integer.
77  */
78 unsigned short Curl_read16_be(const unsigned char *buf)
79 {
80   return (unsigned short)(((unsigned short)buf[0] << 8) |
81                           ((unsigned short)buf[1]));
82 }
83 
84 /*
85  * Curl_write32_le()
86  *
87  * This function converts a 32-bit integer from the native endian format,
88  * to little endian format ready for sending down the wire.
89  *
90  * Parameters:
91  *
92  * value    [in]     - The 32-bit integer value.
93  * buffer   [in]     - A pointer to the output buffer.
94  */
95 void Curl_write32_le(const int value, unsigned char *buffer)
96 {
97   buffer[0] = (char)(value & 0x000000FF);
98   buffer[1] = (char)((value & 0x0000FF00) >> 8);
99   buffer[2] = (char)((value & 0x00FF0000) >> 16);
100   buffer[3] = (char)((value & 0xFF000000) >> 24);
101 }
102 
103 #if (CURL_SIZEOF_CURL_OFF_T > 4)
104 /*
105  * Curl_write64_le()
106  *
107  * This function converts a 64-bit integer from the native endian format,
108  * to little endian format ready for sending down the wire.
109  *
110  * Parameters:
111  *
112  * value    [in]     - The 64-bit integer value.
113  * buffer   [in]     - A pointer to the output buffer.
114  */
115 #if defined(HAVE_LONGLONG)
116 void Curl_write64_le(const long long value, unsigned char *buffer)
117 #else
118 void Curl_write64_le(const __int64 value, unsigned char *buffer)
119 #endif
120 {
121   Curl_write32_le((int)value, buffer);
122   Curl_write32_le((int)(value >> 32), buffer + 4);
123 }
124 #endif /* CURL_SIZEOF_CURL_OFF_T > 4 */
125