/*      $NetBSD: cd9660_util.c,v 1.16 2024/05/25 06:27:57 tsutsui Exp $ */

/*-
* Copyright (c) 1994
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software contributed to Berkeley
* by Pace Willisson ([email protected]).  The Rock Ridge Extension
* Support code is derived from software contributed to Berkeley
* by Atsushi Murai ([email protected]).
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
*
*      @(#)cd9660_util.c       8.3 (Berkeley) 12/5/94
*/

#include <sys/cdefs.h>
#ifdef _KERNEL
__KERNEL_RCSID(0, "$NetBSD: cd9660_util.c,v 1.16 2024/05/25 06:27:57 tsutsui Exp $");
#else
/* used by macppc_installboot */
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#endif

#include <sys/param.h>
#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#else
#include <assert.h>
#include <dirent.h>
#define KASSERT(x)      assert(x)       /* XXX for <fs/unicode.h> */

#if !HAVE_NBTOOL_CONFIG_H || HAVE_SYS_ENDIAN_H
#include <sys/endian.h>         /* for le16dec(9) etc. in iso.h */
#endif
#endif

#include <fs/cd9660/iso.h>
#include <fs/cd9660/cd9660_extern.h>

#include <fs/unicode.h>

static uint16_t wget(const u_char **, size_t *, int);
static int wput(u_char *, size_t, uint16_t, int);

int cd9660_utf8_joliet = 1;

/*
* Get one character out of an iso filename
* Return number of bytes consumed
*/
int
isochar(const u_char *isofn, const u_char *isoend, int joliet_level,
   uint16_t *c)
{

       *c = isofn[0];
       if (joliet_level == 0 || isofn + 1 == isoend) {
               /* (00) and (01) are one byte in Joliet, too */
               return 1;
       }

       if (cd9660_utf8_joliet) {
               *c = (*c << 8) + isofn[1];
       } else {
               /* characters outside ISO-8859-1 subset replaced with '?' */
               if (*c != 0)
                       *c = '?';
               else
                       *c = isofn[1];
       }

       return 2;
}

/*
* translate and compare a filename
* Note: Version number plus ';' may be omitted.
*/
int
isofncmp(const u_char *fn, size_t fnlen, const u_char *isofn, size_t isolen,
   int joliet_level)
{
       int i, j;
       uint16_t fc, ic;
       const u_char *isoend = isofn + isolen;

#ifdef ISOFNCMPDEBUG
       printf("fn = %s, fnlen = %zu, isofn = %s, isolen = %zu\n",
           fn, fnlen, isofn, isolen);
#endif

       while (fnlen > 0) {
               fc = wget(&fn, &fnlen, joliet_level);

               if (isofn == isoend)
                       return fc;
               isofn += isochar(isofn, isoend, joliet_level, &ic);
               if (ic == ';') {
                       switch (fc) {
                       default:
                               return fc;
                       case 0:
                               return 0;
                       case ';':
                               break;
                       }
                       for (i = 0; fnlen-- != 0; i = i * 10 + *fn++ - '0') {
                               if (*fn < '0' || *fn > '9') {
                                       return -1;
                               }
                       }
                       for (j = 0; isofn != isoend; j = j * 10 + ic - '0')
                               isofn += isochar(isofn, isoend,
                                                joliet_level, &ic);
                       return i - j;
               }
               if (ic != fc) {
                       if (ic >= 'A' && ic <= 'Z') {
                               if (ic + ('a' - 'A') != fc) {
                                       if (fc >= 'a' && fc <= 'z')
                                               fc -= 'a' - 'A';

                                       return (int)fc - (int)ic;
                               }
                       } else
                               return (int)fc - (int)ic;
               }
       }
       if (isofn != isoend) {
               isofn += isochar(isofn, isoend, joliet_level, &ic);
               switch (ic) {
               default:
                       return -1;
               case '.':
                       if (isofn != isoend) {
                               isochar(isofn, isoend, joliet_level, &ic);
                               if (ic == ';')
                                       return 0;
                       }
                       return -1;
               case ';':
                       return 0;
               }
       }
       return 0;
}

/*
* translate a filename
*/
void
isofntrans(const u_char *infn, int infnlen, u_char *outfn, u_short *outfnlen,
   int original, int casetrans, int assoc, int joliet_level)
{
       int fnidx = 0;
       const u_char *infnend = infn + infnlen;
       uint16_t c;
       int sz;

       if (assoc) {
               *outfn++ = ASSOCCHAR;
               fnidx++;
       }

       for(; infn != infnend; fnidx += sz) {
               infn += isochar(infn, infnend, joliet_level, &c);

               if (casetrans && joliet_level == 0 && c >= 'A' && c <= 'Z')
                       c = c + ('a' - 'A');
               else if (!original && c == ';') {
                       if (fnidx > 0 && outfn[-1] == '.')
                               fnidx--;
                       break;
               }

               sz = wput(outfn, ISO_MAXNAMLEN - fnidx, c, joliet_level);
               if (sz == 0) {
                       /* not enough space to write the character */
                       if (fnidx < ISO_MAXNAMLEN) {
                               *outfn = '?';
                               fnidx++;
                       }
                       break;
               }
               outfn += sz;
       }
       *outfnlen = fnidx;
}

static uint16_t
wget(const u_char **str, size_t *sz, int joliet_level)
{
       if (joliet_level > 0 && cd9660_utf8_joliet) {
               /* decode UTF-8 sequence */
               return wget_utf8((const char **) str, sz);
       } else {
               /*
                * Raw 8-bit characters without any conversion. For Joliet,
                * this effectively assumes provided file name is using
                * ISO-8859-1 subset.
                */
               uint16_t c = *str[0];
               (*str)++;
               (*sz)--;

               return c;
       }
}

static int
wput(u_char *s, size_t n, uint16_t c, int joliet_level)
{
       if (joliet_level > 0 && cd9660_utf8_joliet) {
               /* Store Joliet file name encoded into UTF-8 */
               return wput_utf8((char *)s, n, c);
       } else {
               /*
                * Store raw 8-bit characters without any conversion.
                * For Joliet case, this filters the Unicode characters
                * to ISO-8859-1 subset.
                */
               *s = (u_char)c;
               return 1;
       }
}