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      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel (at) 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