/*      $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 (pace@blitz.com).  The Rock Ridge Extension
 * Support code is derived from software contributed to Berkeley
 * by Atsushi Murai (amurai@spec.co.jp).
 *
 * 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;
        }
}