/*      $NetBSD: cd9660_conversion.c,v 1.6 2024/06/17 13:31:17 reinoud Exp $    */

/*
* Copyright (c) 2005 Daniel Watt, Walter Deignan, Ryan Gabrys, Alan
* Perez-Rathke and Ram Vedam.  All rights reserved.
*
* This code was written by Daniel Watt, Walter Deignan, Ryan Gabrys,
* Alan Perez-Rathke and Ram Vedam.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
*    copyright notice, this list of conditions and the following
*    disclaimer in the documentation and/or other materials provided
*    with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY DANIEL WATT, WALTER DEIGNAN, RYAN
* GABRYS, ALAN PEREZ-RATHKE AND RAM VEDAM ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED.  IN NO EVENT SHALL DANIEL WATT, WALTER DEIGNAN, RYAN
* GABRYS, ALAN PEREZ-RATHKE AND RAM VEDAM BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE,DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*/
#include "cd9660.h"

#include <sys/cdefs.h>
#if defined(__RCSID) && !defined(__lint)
__RCSID("$NetBSD: cd9660_conversion.c,v 1.6 2024/06/17 13:31:17 reinoud Exp $");
#endif  /* !__lint */


static char cd9660_compute_gm_offset(time_t);

#if 0
static inline int
cd9660_pad_even(length)
int length;
{
       return length + (length & 0x01);
}
#endif

/*
* These can probably be implemented using a macro
*/

/* Little endian */
void
cd9660_721(uint16_t w, unsigned char *twochar)
{
#if BYTE_ORDER == BIG_ENDIAN
       w = bswap16(w);
#endif
       memcpy(twochar,&w,2);
}

void
cd9660_731(uint32_t w, unsigned char *fourchar)
{
#if BYTE_ORDER == BIG_ENDIAN
       w = bswap32(w);
#endif
       memcpy(fourchar,&w,4);
}

/* Big endian */
void
cd9660_722(uint16_t w, unsigned char *twochar)
{
#if BYTE_ORDER == LITTLE_ENDIAN
       w = bswap16(w);
#endif
       memcpy(twochar,&w,2);
}

void
cd9660_732(uint32_t w, unsigned char *fourchar)
{
#if BYTE_ORDER == LITTLE_ENDIAN
       w = bswap32(w);
#endif
       memcpy(fourchar,&w,4);
}

/**
* Convert a dword into a double endian string of eight characters
* @param int The double word to convert
* @param char* The string to write the both endian double word to - It is assumed this is allocated and at least
*               eight characters long
*/
void
cd9660_bothendian_dword(uint32_t dw, unsigned char *eightchar)
{
       uint32_t le, be;
#if BYTE_ORDER == LITTLE_ENDIAN
       le = dw;
       be = bswap32(dw);
#endif
#if BYTE_ORDER == BIG_ENDIAN
       be = dw;
       le = bswap32(dw);
#endif
       memcpy(eightchar, &le, 4);
       memcpy((eightchar+4), &be, 4);
}

/**
* Convert a word into a double endian string of four characters
* @param int The word to convert
* @param char* The string to write the both endian word to - It is assumed this is allocated and at least
*               four characters long
*/
void
cd9660_bothendian_word(uint16_t dw, unsigned char *fourchar)
{
       uint16_t le, be;
#if BYTE_ORDER == LITTLE_ENDIAN
       le = dw;
       be = bswap16(dw);
#endif
#if BYTE_ORDER == BIG_ENDIAN
       be = dw;
       le = bswap16(dw);
#endif
       memcpy(fourchar, &le, 2);
       memcpy((fourchar+2), &be, 2);
}

void
cd9660_pad_string_spaces(char *str, int len)
{
       int i;

       for (i = 0; i < len; i ++) {
               if (str[i] == '\0')
                       str[i] = 0x20;
       }
}

static char
cd9660_compute_gm_offset(time_t tim)
{
       if (stampst.st_ino)
               return 0;

       struct tm t, gm;

       (void)localtime_r(&tim, &t);
       (void)gmtime_r(&tim, &gm);
       gm.tm_year -= t.tm_year;
       gm.tm_yday -= t.tm_yday;
       gm.tm_hour -= t.tm_hour;
       gm.tm_min  -= t.tm_min;
       if (gm.tm_year < 0)
               gm.tm_yday = -1;
       else if (gm.tm_year > 0)
               gm.tm_yday = 1;

       return (char)(-(gm.tm_min + 60* (24 * gm.tm_yday + gm.tm_hour)) / 15);
}

/* Long dates: 17 characters */
void
cd9660_time_8426(unsigned char *buf, time_t tim)
{
       struct tm t;
       char temp[70];  /* we know its only 18 but gcc can't figure this out */

       if (stampst.st_ino)
               (void)gmtime_r(&tim, &t);
       else
               (void)localtime_r(&tim, &t);
       (void)snprintf(temp, sizeof(temp), "%04i%02i%02i%02i%02i%02i%02i",
               1900+(int)t.tm_year,
               (int)t.tm_mon+1,
               (int)t.tm_mday,
               (int)t.tm_hour,
               (int)t.tm_min,
               (int)t.tm_sec,
               0);
       (void)memcpy(buf, temp, 16);
       buf[16] = cd9660_compute_gm_offset(tim);
}

/* Short dates: 7 characters */
void
cd9660_time_915(unsigned char *buf, time_t tim)
{
       struct tm t;

       if (stampst.st_ino)
               (void)gmtime_r(&tim, &t);
       else
               (void)localtime_r(&tim, &t);
       buf[0] = t.tm_year;
       buf[1] = t.tm_mon+1;
       buf[2] = t.tm_mday;
       buf[3] = t.tm_hour;
       buf[4] = t.tm_min;
       buf[5] = t.tm_sec;
       buf[6] = cd9660_compute_gm_offset(tim);
}