The Tcpdump Group git mirrors - tcpdump/blob - extract.h

   1 /*
   2  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * @(#) $Header: /tcpdump/master/tcpdump/extract.h,v 1.17 2001-09-17 21:57:52 fenner Exp $ (LBL)
  22  */
  23
  24 /* Network to host order macros */
  25
  26 #ifdef LBL_ALIGN
  27 #define EXTRACT_16BITS(p) \
  28         ((u_int16_t)*((const u_int8_t *)(p) + 0) << 8 | \
  29         (u_int16_t)*((const u_int8_t *)(p) + 1))
  30 #define EXTRACT_32BITS(p) \
  31         ((u_int32_t)*((const u_int8_t *)(p) + 0) << 24 | \
  32         (u_int32_t)*((const u_int8_t *)(p) + 1) << 16 | \
  33         (u_int32_t)*((const u_int8_t *)(p) + 2) << 8 | \
  34         (u_int32_t)*((const u_int8_t *)(p) + 3))
  35 #else
  36 #define EXTRACT_16BITS(p) \
  37         ((u_int16_t)ntohs(*(const u_int16_t *)(p)))
  38 #define EXTRACT_32BITS(p) \
  39         ((u_int32_t)ntohl(*(const u_int32_t *)(p)))
  40 #endif
  41
  42 #define EXTRACT_24BITS(p) \
  43         ((u_int32_t)*((const u_int8_t *)(p) + 0) << 16 | \
  44         (u_int32_t)*((const u_int8_t *)(p) + 1) << 8 | \
  45         (u_int32_t)*((const u_int8_t *)(p) + 2))
  46
  47 /* Little endian protocol host order macros */
  48
  49 #define EXTRACT_LE_8BITS(p) (*(p))
  50 #define EXTRACT_LE_16BITS(p) \
  51         ((u_int16_t)*((const u_int8_t *)(p) + 1) << 8 | \
  52         (u_int16_t)*((const u_int8_t *)(p) + 0))
  53 #define EXTRACT_LE_32BITS(p) \
  54         ((u_int32_t)*((const u_int8_t *)(p) + 3) << 24 | \
  55         (u_int32_t)*((const u_int8_t *)(p) + 2) << 16 | \
  56         (u_int32_t)*((const u_int8_t *)(p) + 1) << 8 | \
  57         (u_int32_t)*((const u_int8_t *)(p) + 0))