/*
** get
** The Sleuth Kit
**
** $Date: 2007/03/23 15:02:18 $ 
**
** routines to get values in a structure that solves endian issues
**
** Brian Carrier [carrier@sleuthkit.org]
** Copyright (c) 2003-2005 Brian Carrier.  All rights reserved 
**
** Copyright (c) 2002 Brian Carrier, @stake Inc.  All rights reserved
**
** This software is distributed under the Common Public License 1.0
**
*/

#include "aux_tools.h"


/* A temporary data structure with an endian field */
typedef struct {
    uint8_t endian;
} tmp_ds;

/*
 * try both endian orderings to figure out which one is equal to 'val'
 *
 * if neither of them do, then 1 is returned.  Else 0 is.
 * fs->flags will be set accordingly
 */
uint8_t
tsk_guess_end_u16(uint8_t * flag, uint8_t * x, uint16_t val)
{
    /* try little */
    if (tsk_getu16(TSK_LIT_ENDIAN, x) == val) {
        *flag &= ~TSK_BIG_ENDIAN;
        *flag |= TSK_LIT_ENDIAN;
        return 0;
    }

    /* ok, big now */
    if (tsk_getu16(TSK_BIG_ENDIAN, x) == val) {
        *flag &= ~TSK_LIT_ENDIAN;
        *flag |= TSK_BIG_ENDIAN;
        return 0;
    }

    /* didn't find it */
    return 1;
}

/*
 * same idea as guessu16 except that val is a 32-bit value
 *
 * return 1 on error and 0 else
 */
uint8_t
tsk_guess_end_u32(uint8_t * flag, uint8_t * x, uint32_t val)
{
    /* try little */
    if (tsk_getu32(TSK_LIT_ENDIAN, x) == val) {
        *flag &= ~TSK_BIG_ENDIAN;
        *flag |= TSK_LIT_ENDIAN;
        return 0;
    }

    /* ok, big now */
    if (tsk_getu32(TSK_BIG_ENDIAN, x) == val) {
        *flag &= ~TSK_LIT_ENDIAN;
        *flag |= TSK_BIG_ENDIAN;
        return 0;
    }

    return 1;
}