lwpa_pack

Overview

Platform- and endianness-independent buffer packing and unpacking.

#include "lwpa_pack.h"

This module defines macros for packing and unpacking integer types to/from a byte buffer. They are architected in such a way that the endianness of the integer in the buffer is always known, regardless of the endianness of your platform.

Macros
#define	upack_16b(ptr)
	Unpack a uint16_t from a known big-endian buffer. More...
#define	pack_16b(ptr, val)
	Pack a uint16_t to a known big-endian buffer. More...
#define	upack_16l(ptr)
	Unpack a uint16_t from a known little-endian buffer. More...
#define	pack_16l(ptr, val)
	Pack a uint16_t to a known little-endian buffer. More...
#define	upack_32b(ptr)
	Unpack a uint32_t from a known big-endian buffer. More...
#define	pack_32b(ptr, val)
	Pack a uint32_t to a known big-endian buffer. More...
#define	upack_32l(ptr)
	Unpack a uint32_t from a known little-endian buffer. More...
#define	pack_32l(ptr, val)
	Pack a uint32_t to a known little-endian buffer. More...
#define	upack_64b(ptr)
	Unpack a uint64_t from a known big-endian buffer. More...
#define	pack_64b(ptr, val)
	Pack a uint64_t to a known big-endian buffer. More...
#define	upack_64l(ptr)
	Unpack a uint64_t from a known little-endian buffer. More...
#define	pack_64l(ptr, val)
	Pack a uint64_t to a known little-endian buffer. More...

Macro Definition Documentation

pack_16b

#define pack_16b	(		ptr,
			val
	)

Value:

  do                                                          \
  {                                                           \
    ((uint8_t *)(ptr))[1] = (uint8_t) ((val) & 0xff);         \
    ((uint8_t *)(ptr))[0] = (uint8_t)(((val) & 0xff00) >> 8); \
  } while (0)

Pack a uint16_t to a known big-endian buffer.

Parameters

ptr	Pointer to the buffer into which to pack a uint16_t.
val	uint16_t value to pack into the buffer.

pack_16l

#define pack_16l	(		ptr,
			val
	)

Value:

  do                                                          \
  {                                                           \
    ((uint8_t *)(ptr))[0] = (uint8_t) ((val) & 0xff);         \
    ((uint8_t *)(ptr))[1] = (uint8_t)(((val) & 0xff00) >> 8); \
  } while (0)

Pack a uint16_t to a known little-endian buffer.

Parameters

ptr	Pointer to the buffer into which to pack a uint16_t.
val	uint16_t value to pack into the buffer.

pack_32b

#define pack_32b	(		ptr,
			val
	)

Value:

  do                                                               \
  {                                                                \
    ((uint8_t *)(ptr))[3] = (uint8_t) ((val) & 0xff);              \
    ((uint8_t *)(ptr))[2] = (uint8_t)(((val) & 0xff00) >> 8);      \
    ((uint8_t *)(ptr))[1] = (uint8_t)(((val) & 0xff0000) >> 16);   \
    ((uint8_t *)(ptr))[0] = (uint8_t)(((val) & 0xff000000) >> 24); \
  } while (0)

Pack a uint32_t to a known big-endian buffer.

Parameters

ptr	Pointer to the buffer into which to pack a uint32_t.
val	uint32_t value to pack into the buffer.

pack_32l

#define pack_32l	(		ptr,
			val
	)

Value:

  do                                                               \
  {                                                                \
    ((uint8_t *)(ptr))[0] = (uint8_t) ((val) & 0xff);              \
    ((uint8_t *)(ptr))[1] = (uint8_t)(((val) & 0xff00) >> 8);      \
    ((uint8_t *)(ptr))[2] = (uint8_t)(((val) & 0xff0000) >> 16);   \
    ((uint8_t *)(ptr))[3] = (uint8_t)(((val) & 0xff000000) >> 24); \
  } while (0)

Pack a uint32_t to a known little-endian buffer.

Parameters

ptr	Pointer to the buffer into which to pack a uint32_t.
val	uint32_t value to pack into the buffer.

pack_64b

#define pack_64b	(		ptr,
			val
	)

Value:

  do                                                                       \
  {                                                                        \
    ((uint8_t *)(ptr))[7] = (uint8_t) ((val) & 0xff);                      \
    ((uint8_t *)(ptr))[6] = (uint8_t)(((val) & 0xff00) >> 8);              \
    ((uint8_t *)(ptr))[5] = (uint8_t)(((val) & 0xff0000) >> 16);           \
    ((uint8_t *)(ptr))[4] = (uint8_t)(((val) & 0xff000000) >> 24);         \
    ((uint8_t *)(ptr))[3] = (uint8_t)(((val) & 0xff00000000) >> 32);       \
    ((uint8_t *)(ptr))[2] = (uint8_t)(((val) & 0xff0000000000) >> 40);     \
    ((uint8_t *)(ptr))[1] = (uint8_t)(((val) & 0xff000000000000) >> 48);   \
    ((uint8_t *)(ptr))[0] = (uint8_t)(((val) & 0xff00000000000000) >> 56); \
  } while (0)

Pack a uint64_t to a known big-endian buffer.

Parameters

ptr	Pointer to the buffer into which to pack a uint64_t.
val	uint64_t value to pack into the buffer.

pack_64l

#define pack_64l	(		ptr,
			val
	)

Value:

  do                                                                       \
  {                                                                        \
    ((uint8_t *)(ptr))[0] = (uint8_t) ((val) & 0xff);                      \
    ((uint8_t *)(ptr))[1] = (uint8_t)(((val) & 0xff00) >> 8);              \
    ((uint8_t *)(ptr))[2] = (uint8_t)(((val) & 0xff0000) >> 16);           \
    ((uint8_t *)(ptr))[3] = (uint8_t)(((val) & 0xff000000) >> 24);         \
    ((uint8_t *)(ptr))[4] = (uint8_t)(((val) & 0xff00000000) >> 32);       \
    ((uint8_t *)(ptr))[5] = (uint8_t)(((val) & 0xff0000000000) >> 40);     \
    ((uint8_t *)(ptr))[6] = (uint8_t)(((val) & 0xff000000000000) >> 48);   \
    ((uint8_t *)(ptr))[7] = (uint8_t)(((val) & 0xff00000000000000) >> 56); \
  } while (0)

Pack a uint64_t to a known little-endian buffer.

Parameters

ptr	Pointer to the buffer into which to pack a uint64_t.
val	uint64_t value to pack into the buffer.

upack_16b

#define upack_16b

(

ptr

)

Value:

  (((uint16_t)0u) |                           \
   (((uint16_t)((uint8_t *)(ptr))[0]) << 8) | \
    ((uint16_t)((uint8_t *)(ptr))[1]))

Unpack a uint16_t from a known big-endian buffer.

Parameters

ptr	Pointer to the buffer from which to unpack a uint16_t.

Returns

Unpacked uint16_t.

upack_16l

#define upack_16l

(

ptr

)

Value:

  (((uint16_t)0u) |                           \
   (((uint16_t)((uint8_t *)(ptr))[1]) << 8) | \
    ((uint16_t)((uint8_t *)(ptr))[0]))

Unpack a uint16_t from a known little-endian buffer.

Parameters

ptr	Pointer to the buffer from which to unpack a uint16_t.

Returns

Unpacked uint16_t.

upack_32b

#define upack_32b

(

ptr

)

Value:

  (((uint32_t)0u) |                            \
   (((uint32_t)((uint8_t *)(ptr))[0]) << 24) | \
   (((uint32_t)((uint8_t *)(ptr))[1]) << 16) | \
   (((uint32_t)((uint8_t *)(ptr))[2]) << 8)  | \
    ((uint32_t)((uint8_t *)(ptr))[3]))

Unpack a uint32_t from a known big-endian buffer.

Parameters

ptr	Pointer to the buffer from which to unpack a uint32_t.

Returns

Unpacked uint32_t.

upack_32l

#define upack_32l

(

ptr

)

Value:

  (((uint32_t)0u) |                            \
   (((uint32_t)((uint8_t *)(ptr))[3]) << 24) | \
   (((uint32_t)((uint8_t *)(ptr))[2]) << 16) | \
   (((uint32_t)((uint8_t *)(ptr))[1]) << 8)  | \
    ((uint32_t)((uint8_t *)(ptr))[0]))

Unpack a uint32_t from a known little-endian buffer.

Parameters

ptr	Pointer to the buffer from which to unpack a uint32_t.

Returns

Unpacked uint32_t.

upack_64b

#define upack_64b

(

ptr

)

Value:

  (((uint64_t)0u) |                            \
   (((uint64_t)((uint8_t *)(ptr))[0]) << 56) | \
   (((uint64_t)((uint8_t *)(ptr))[1]) << 48) | \
   (((uint64_t)((uint8_t *)(ptr))[2]) << 40) | \
   (((uint64_t)((uint8_t *)(ptr))[3]) << 32) | \
   (((uint64_t)((uint8_t *)(ptr))[4]) << 24) | \
   (((uint64_t)((uint8_t *)(ptr))[5]) << 16) | \
   (((uint64_t)((uint8_t *)(ptr))[6]) << 8)  | \
    ((uint64_t)((uint8_t *)(ptr))[7]))

Unpack a uint64_t from a known big-endian buffer.

Parameters

ptr	Pointer to the buffer from which to unpack a uint64_t.

Returns

Unpacked uint64_t.

upack_64l

#define upack_64l

(

ptr

)

Value:

  (((uint64_t)0u) |                            \
   (((uint64_t)((uint8_t *)(ptr))[7]) << 56) | \
   (((uint64_t)((uint8_t *)(ptr))[6]) << 48) | \
   (((uint64_t)((uint8_t *)(ptr))[5]) << 40) | \
   (((uint64_t)((uint8_t *)(ptr))[4]) << 32) | \
   (((uint64_t)((uint8_t *)(ptr))[3]) << 24) | \
   (((uint64_t)((uint8_t *)(ptr))[2]) << 16) | \
   (((uint64_t)((uint8_t *)(ptr))[1]) << 8)  | \
    ((uint64_t)((uint8_t *)(ptr))[0]))

Unpack a uint64_t from a known little-endian buffer.

Parameters

ptr	Pointer to the buffer from which to unpack a uint64_t.

Returns

Unpacked uint64_t.