// SPDX-License-Identifier: GPL-2.0

  /*
   *  linux/fs/isofs/joliet.c
   *
   *  (C) 1996 Gordon Chaffee
   *
   *  Joliet: Microsoft's Unicode extensions to iso9660
   */

  #include <linux/types.h>

  #include <linux/nls.h>

  #include "isofs.h"

  
  /*

   * Convert Unicode 16 to UTF-8 or ASCII.

   */
  static int

  uni16_to_x8(unsigned char *ascii, __be16 *uni, int len, struct nls_table *nls)

  {

  	__be16 *ip, ch;

  	unsigned char *op;
  
  	ip = uni;
  	op = ascii;
  
  	while ((ch = get_unaligned(ip)) && len) {
  		int llen;

  		llen = nls->uni2char(be16_to_cpu(ch), op, NLS_MAX_CHARSET_SIZE);
  		if (llen > 0)

  			op += llen;
  		else
  			*op++ = '?';
  		ip++;
  
  		len--;
  	}
  	*op = 0;
  	return (op - ascii);
  }

  int
  get_joliet_filename(struct iso_directory_record * de, unsigned char *outname, struct inode * inode)
  {
  	unsigned char utf8;
  	struct nls_table *nls;
  	unsigned char len = 0;
  
  	utf8 = ISOFS_SB(inode->i_sb)->s_utf8;
  	nls = ISOFS_SB(inode->i_sb)->s_nls_iocharset;
  
  	if (utf8) {

  		len = utf16s_to_utf8s((const wchar_t *) de->name,
  				de->name_len[0] >> 1, UTF16_BIG_ENDIAN,
  				outname, PAGE_SIZE);

  	} else {

  		len = uni16_to_x8(outname, (__be16 *) de->name,

  				de->name_len[0] >> 1, nls);

  	}

  	if ((len > 2) && (outname[len-2] == ';') && (outname[len-1] == '1'))

  		len -= 2;

  
  	/*
  	 * Windows doesn't like periods at the end of a name,
  	 * so neither do we
  	 */

  	while (len >= 2 && (outname[len-1] == '.'))

  		len--;

  
  	return len;
  }