tor-android/external/badvpn_dns/misc/byteorder.h

197 lines
4.4 KiB
C

/**
* @file byteorder.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* Byte order conversion functions.
*
* hton* functions convert from host to big-endian (network) byte order.
* htol* functions convert from host to little-endian byte order.
* ntoh* functions convert from big-endian (network) to host byte order.
* ltoh* functions convert from little-endian to host byte order.
*/
#ifndef BADVPN_MISC_BYTEORDER_H
#define BADVPN_MISC_BYTEORDER_H
#if (defined(BADVPN_LITTLE_ENDIAN) + defined(BADVPN_BIG_ENDIAN)) != 1
#error Unknown byte order or too many byte orders
#endif
#include <stdint.h>
static uint16_t badvpn_reverse16 (uint16_t x)
{
uint16_t y;
*((uint8_t *)&y+0) = *((uint8_t *)&x+1);
*((uint8_t *)&y+1) = *((uint8_t *)&x+0);
return y;
}
static uint32_t badvpn_reverse32 (uint32_t x)
{
uint32_t y;
*((uint8_t *)&y+0) = *((uint8_t *)&x+3);
*((uint8_t *)&y+1) = *((uint8_t *)&x+2);
*((uint8_t *)&y+2) = *((uint8_t *)&x+1);
*((uint8_t *)&y+3) = *((uint8_t *)&x+0);
return y;
}
static uint64_t badvpn_reverse64 (uint64_t x)
{
uint64_t y;
*((uint8_t *)&y+0) = *((uint8_t *)&x+7);
*((uint8_t *)&y+1) = *((uint8_t *)&x+6);
*((uint8_t *)&y+2) = *((uint8_t *)&x+5);
*((uint8_t *)&y+3) = *((uint8_t *)&x+4);
*((uint8_t *)&y+4) = *((uint8_t *)&x+3);
*((uint8_t *)&y+5) = *((uint8_t *)&x+2);
*((uint8_t *)&y+6) = *((uint8_t *)&x+1);
*((uint8_t *)&y+7) = *((uint8_t *)&x+0);
return y;
}
static uint8_t hton8 (uint8_t x)
{
return x;
}
static uint8_t htol8 (uint8_t x)
{
return x;
}
#if defined(BADVPN_LITTLE_ENDIAN)
static uint16_t hton16 (uint16_t x)
{
return badvpn_reverse16(x);
}
static uint32_t hton32 (uint32_t x)
{
return badvpn_reverse32(x);
}
static uint64_t hton64 (uint64_t x)
{
return badvpn_reverse64(x);
}
static uint16_t htol16 (uint16_t x)
{
return x;
}
static uint32_t htol32 (uint32_t x)
{
return x;
}
static uint64_t htol64 (uint64_t x)
{
return x;
}
#elif defined(BADVPN_BIG_ENDIAN)
static uint16_t hton16 (uint16_t x)
{
return x;
}
static uint32_t hton32 (uint32_t x)
{
return x;
}
static uint64_t hton64 (uint64_t x)
{
return x;
}
static uint16_t htol16 (uint16_t x)
{
return badvpn_reverse16(x);
}
static uint32_t htol32 (uint32_t x)
{
return badvpn_reverse32(x);
}
static uint64_t htol64 (uint64_t x)
{
return badvpn_reverse64(x);
}
#endif
static uint8_t ntoh8 (uint8_t x)
{
return hton8(x);
}
static uint16_t ntoh16 (uint16_t x)
{
return hton16(x);
}
static uint32_t ntoh32 (uint32_t x)
{
return hton32(x);
}
static uint64_t ntoh64 (uint64_t x)
{
return hton64(x);
}
static uint8_t ltoh8 (uint8_t x)
{
return htol8(x);
}
static uint16_t ltoh16 (uint16_t x)
{
return htol16(x);
}
static uint32_t ltoh32 (uint32_t x)
{
return htol32(x);
}
static uint64_t ltoh64 (uint64_t x)
{
return htol64(x);
}
#endif