include/net/hton.h

   1 /*
   2 The following macro definitions convert to and from the network standard byte
   3 order. The macros with their name in lower case guarantee to evaluate their
   4 argument exactly once. The function of the macros is encoded in their names;
   5 htons means convert a (unsigned) short in host byte order to network byte order.
   6 */
   7
   8 #ifndef _NET__HTON_H
   9 #define _NET__HTON_H
  10
  11 #include <minix/sys_config.h>
  12
  13 extern u16_t _tmp;
  14 extern u32_t _tmp_l;
  15
  16 /* Find out about the byte order. */
  17
  18 /* assume <minix/config.h> is included, let's check */
  19 #if (_MINIX_CHIP == 0)
  20 #include "_MINIX_CHIP macro not set, include <minix/config.h>"
  21 #endif
  22
  23 #if (_MINIX_CHIP == _CHIP_INTEL)
  24 #define LITTLE_ENDIAN   1
  25 #endif
  26
  27 #if (_MINIX_CHIP == _CHIP_M68000 || _MINIX_CHIP == _CHIP_SPARC)
  28 #define BIG_ENDIAN      1
  29 #endif
  30
  31 #if (LITTLE_ENDIAN) && (BIG_ENDIAN)
  32 #include "both LITTLE_ENDIAN and BIG_ENDIAN are defined"
  33                         /* LITTLE_ENDIAN and BIG_ENDIAN are both defined */
  34 #endif
  35
  36 #if !(LITTLE_ENDIAN) && !(BIG_ENDIAN)
  37 #include "neither LITTLE_ENDIAN nor BIG_ENDIAN is defined"
  38                         /* LITTLE_ENDIAN and BIG_ENDIAN are both NOT defined */
  39 #endif
  40
  41 #if LITTLE_ENDIAN
  42 #define HTONS(x) ( ( (((unsigned short)(x)) >>8) & 0xff) | \
  43                 ((((unsigned short)(x)) & 0xff)<<8) )
  44 #define NTOHS(x) ( ( (((unsigned short)(x)) >>8) & 0xff) | \
  45                 ((((unsigned short)(x)) & 0xff)<<8) )
  46 #define HTONL(x) ((((x)>>24) & 0xffL) | (((x)>>8) & 0xff00L) | \
  47                 (((x)<<8) & 0xff0000L) | (((x)<<24) & 0xff000000L))
  48 #define NTOHL(x) ((((x)>>24) & 0xffL) | (((x)>>8) & 0xff00L) | \
  49                 (((x)<<8) & 0xff0000L) | (((x)<<24) & 0xff000000L))
  50
  51 #if _WORD_SIZE > 2
  52 #define htons(x) (_tmp=(x), ((_tmp>>8) & 0xff) | ((_tmp<<8) & 0xff00))
  53 #define ntohs(x) (_tmp=(x), ((_tmp>>8) & 0xff) | ((_tmp<<8) & 0xff00))
  54 #define htonl(x) (_tmp_l=(x), ((_tmp_l>>24) & 0xffL) | \
  55                 ((_tmp_l>>8) & 0xff00L) | \
  56                 ((_tmp_l<<8) & 0xff0000L) | ((_tmp_l<<24) & 0xff000000L))
  57 #define ntohl(x) (_tmp_l=(x), ((_tmp_l>>24) & 0xffL) \
  58                 | ((_tmp_l>>8) & 0xff00L) | \
  59                 ((_tmp_l<<8) & 0xff0000L) | ((_tmp_l<<24) & 0xff000000L))
  60
  61 #else /* _WORD_SIZE == 2 */
  62 /* The above macros are too unwieldy for a 16-bit machine. */
  63 u16_t htons(u16_t x);
  64 u16_t ntohs(u16_t x);
  65 u32_t htonl(u32_t x);
  66 u32_t ntohl(u32_t x);
  67 #endif /* _WORD_SIZE == 2 */
  68
  69 #endif /* LITTLE_ENDIAN */
  70
  71 #if BIG_ENDIAN
  72 #define htons(x) (x)
  73 #define HTONS(x) (x)
  74 #define ntohs(x) (x)
  75 #define NTOHS(x) (x)
  76 #define htonl(x) (x)
  77 #define HTONL(x) (x)
  78 #define ntohl(x) (x)
  79 #define NTOHL(x) (x)
  80 #endif /* BIG_ENDIAN */
  81
  82 #endif /* _NET__HTON_H */