include/squid_endian.h

   1 /*
   2  * AUTHOR: Alan Barrett
   3  *
   4  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   5  * ----------------------------------------------------------
   6  *
   7  *  Squid is the result of efforts by numerous individuals from
   8  *  the Internet community; see the CONTRIBUTORS file for full
   9  *  details.   Many organizations have provided support for Squid's
  10  *  development; see the SPONSORS file for full details.  Squid is
  11  *  Copyrighted (C) 2001 by the Regents of the University of
  12  *  California; see the COPYRIGHT file for full details.  Squid
  13  *  incorporates software developed and/or copyrighted by other
  14  *  sources; see the CREDITS file for full details.
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License as published by
  18  *  the Free Software Foundation; either version 2 of the License, or
  19  *  (at your option) any later version.
  20  *
  21  *  This program is distributed in the hope that it will be useful,
  22  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *  GNU General Public License for more details.
  25  *
  26  *  You should have received a copy of the GNU General Public License
  27  *  along with this program; if not, write to the Free Software
  28  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  29  *
  30  */
  31
  32 #ifndef SQUID_ENDIAN_H
  33 #define SQUID_ENDIAN_H
  34
  35 /*
  36  * Macros to deal with byte swapping.  These macros provide
  37  * the following interface:
  38  *
  39  * // Byte-swap
  40  * uint16_t bswap16(uint16_t);
  41  * uint32_t bswap32(uint32_t);
  42  *
  43  * // Convert from host byte order to big-endian, and vice versa.
  44  * uint16_t htobe16(uint16_t); // equivalent to htons()
  45  * uint32_t htobe32(uint32_t); // equivalent to htonl()
  46  * uint16_t be16toh(uint16_t); // equivalent to ntohs()
  47  * uint32_t be32toh(uint32_t); // equivalent to ntohs()
  48  *
  49  * // Convert from host byte order to little-endian, and vice versa.
  50  * uint16_t htole16(uint16_t);
  51  * uint32_t htole32(uint32_t);
  52  * uint16_t le16toh(uint16_t);
  53  * uint32_t le32toh(uint32_t);
  54  */
  55
  56 /*
  57  * Some systems define bswap_16() and bswap_32() in <byteswap.h>
  58  *
  59  * Some systems define bswap16() and bswap32() in <sys/bswap.h>.
  60  *
  61  * Some systems define htobe16()/be16toh() and friends in <sys/endian.h>.
  62  */
  63 #if HAVE_BYTESWAP_H
  64 #  include <byteswap.h>
  65 #endif /* HAVE_BYTESWAP_H */
  66 #if HAVE_MACHINE_BYTE_SWAP_H
  67 #  include <machine/byte_swap.h>
  68 #endif  /* HAVE_MACHINE_BYTE_SWAP_H */
  69 #if HAVE_SYS_BSWAP_H
  70 #  include <sys/bswap.h>
  71 #endif /* HAVE_SYS_BSWAP_H */
  72 #if HAVE_SYS_ENDIAN_H
  73 #  include <sys/endian.h>
  74 #endif /* HAVE_SYS_ENDIAN_H */
  75
  76 /*
  77  * Define bswap16() and bswap32() in terms of bswap_16() and bswap_32(),
  78  * or the hard way.
  79  */
  80 #if ! HAVE_BSWAP16 && ! defined(bswap16)
  81 #  if defined(bswap_16)
  82 #    define bswap16(x) bswap_16(x)
  83 #  else
  84 #    define bswap16(x) \
  85        (((((uint16_t)(x)) >> 8) & 0xff) | ((((uint16_t)(x)) & 0xff) << 8))
  86 #  endif
  87 #endif /* ! HAVE_BSWAP16 && ! defined(bswap16) */
  88 #if ! HAVE_BSWAP32 && ! defined(bswap32)
  89 #  if defined(bswap_32)
  90 #    define bswap32(x) bswap_32(x)
  91 #  else
  92 #    define bswap32(x) \
  93        (((((uint32_t)(x)) & 0xff000000) >> 24) | \
  94         ((((uint32_t)(x)) & 0x00ff0000) >>  8) | \
  95         ((((uint32_t)(x)) & 0x0000ff00) <<  8) | \
  96         ((((uint32_t)(x)) & 0x000000ff) << 24))
  97 #  endif
  98 #endif /* ! HAVE_BSWAP32 && ! defined(bswap32) */
  99
 100 /*
 101  * Define htobe*()/be*toh() in terms of hton*()/ntoh*().
 102  *
 103  * XXX: If htobe16() is missing, we assume that the other *be*() functions
 104  *      are also missing.
 105  */
 106 #if ! HAVE_HTOBE16 && ! defined(htobe16)
 107 #  ifdef WORDS_BIGENDIAN
 108 #    define htobe16(x) (x)
 109 #    define htobe32(x) (x)
 110 #    define be16toh(x) (x)
 111 #    define be32toh(x) (x)
 112 #  else /* ! WORDS_BIGENDIAN */
 113 #    define htobe16(x) htons(x)
 114 #    define htobe32(x) htonl(x)
 115 #    define be16toh(x) ntohs(x)
 116 #    define be32toh(x) ntohl(x)
 117 #  endif /* ! WORDS_BIGENDIAN */
 118 #endif /* ! HAVE_HTOBE16 && ! defined(htobe16) */
 119
 120 /*
 121  * Define htole*()/le*toh() in terms of bswap*().
 122  *
 123  * XXX: If htole16() is missing, we assume that the other *le*() functions
 124  *      are also missing.
 125  *
 126  *      Except OpenBSD - htole16 & 32 exist, but not le16toh etc
 127  */
 128 #if _SQUID_OPENBSD_
 129 #  define le16toh(x) htole16(x)
 130 #  define le32toh(x) htole32(x)
 131 #endif
 132
 133 #if ! HAVE_HTOLE16 && ! defined(htole16)
 134 #  ifdef WORDS_BIGENDIAN
 135 #    define htole16(x) bswap16(x)
 136 #    define htole32(x) bswap32(x)
 137 #    define le16toh(x) bswap16(x)
 138 #    define le32toh(x) bswap32(x)
 139 #  else /* ! WORDS_BIGENDIAN */
 140 /*
 141 * XXX: What about unusual byte orders like 3412 or 2143 ?
 142 *      Nothing else in squid seems to care about them,
 143 *      so we don't worry about them here either.
 144 */
 145 #    define htole16(x) (x)
 146 #    define htole32(x) (x)
 147 #    define le16toh(x) (x)
 148 #    define le32toh(x) (x)
 149 #  endif /* ! WORDS_BIGENDIAN */
 150 #endif /* ! HAVE_HTOLE16 && ! defined(htole16) */
 151
 152 #endif /* SQUID_ENDIAN_H */