/*
   *  linux/fs/hfs/trans.c
   *
   * Copyright (C) 1995-1997  Paul H. Hargrove
   * This file may be distributed under the terms of the GNU General Public License.
   *
   * This file contains routines for converting between the Macintosh
   * character set and various other encodings.  This includes dealing
   * with ':' vs. '/' as the path-element separator.
   */
  
  #include <linux/types.h>
  #include <linux/nls.h>
  
  #include "hfs_fs.h"
  
  /*================ Global functions ================*/
  
  /*
   * hfs_mac2asc()
   *
   * Given a 'Pascal String' (a string preceded by a length byte) in
   * the Macintosh character set produce the corresponding filename using
   * the 'trivial' name-mangling scheme, returning the length of the
   * mangled filename.  Note that the output string is not NULL
   * terminated.
   *
   * The name-mangling works as follows:
   * The character '/', which is illegal in Linux filenames is replaced
   * by ':' which never appears in HFS filenames.	 All other characters
   * are passed unchanged from input to output.
   */
  int hfs_mac2asc(struct super_block *sb, char *out, const struct hfs_name *in)
  {
  	struct nls_table *nls_disk = HFS_SB(sb)->nls_disk;
  	struct nls_table *nls_io = HFS_SB(sb)->nls_io;
  	const char *src;
  	char *dst;
  	int srclen, dstlen, size;
  
  	src = in->name;
  	srclen = in->len;
  	if (srclen > HFS_NAMELEN)
  		srclen = HFS_NAMELEN;
  	dst = out;
  	dstlen = HFS_MAX_NAMELEN;
  	if (nls_io) {
  		wchar_t ch;
  
  		while (srclen > 0) {
  			if (nls_disk) {
  				size = nls_disk->char2uni(src, srclen, &ch);
  				if (size <= 0) {
  					ch = '?';
  					size = 1;
  				}
  				src += size;
  				srclen -= size;
  			} else {
  				ch = *src++;
  				srclen--;
  			}
  			if (ch == '/')
  				ch = ':';
  			size = nls_io->uni2char(ch, dst, dstlen);
  			if (size < 0) {
  				if (size == -ENAMETOOLONG)
  					goto out;
  				*dst = '?';
  				size = 1;
  			}
  			dst += size;
  			dstlen -= size;
  		}
  	} else {
  		char ch;
  
  		while (--srclen >= 0)
  			*dst++ = (ch = *src++) == '/' ? ':' : ch;
  	}
  out:
  	return dst - out;
  }
  
  /*
   * hfs_asc2mac()
   *
   * Given an ASCII string (not null-terminated) and its length,
   * generate the corresponding filename in the Macintosh character set
   * using the 'trivial' name-mangling scheme, returning the length of
   * the mangled filename.  Note that the output string is not NULL
   * terminated.
   *
   * This routine is a inverse to hfs_mac2triv().
   * A ':' is replaced by a '/'.
   */
  void hfs_asc2mac(struct super_block *sb, struct hfs_name *out, struct qstr *in)
  {
  	struct nls_table *nls_disk = HFS_SB(sb)->nls_disk;
  	struct nls_table *nls_io = HFS_SB(sb)->nls_io;
  	const char *src;
  	char *dst;
  	int srclen, dstlen, size;
  
  	src = in->name;
  	srclen = in->len;
  	dst = out->name;
  	dstlen = HFS_NAMELEN;
  	if (nls_io) {
  		wchar_t ch;
  
  		while (srclen > 0) {
  			size = nls_io->char2uni(src, srclen, &ch);
  			if (size < 0) {
  				ch = '?';
  				size = 1;
  			}
  			src += size;
  			srclen -= size;
  			if (ch == ':')
  				ch = '/';
  			if (nls_disk) {
  				size = nls_disk->uni2char(ch, dst, dstlen);
  				if (size < 0) {
  					if (size == -ENAMETOOLONG)
  						goto out;
  					*dst = '?';
  					size = 1;
  				}
  				dst += size;
  				dstlen -= size;
  			} else {
  				*dst++ = ch > 0xff ? '?' : ch;
  				dstlen--;
  			}
  		}
  	} else {
  		char ch;
  
  		if (dstlen > srclen)
  			dstlen = srclen;
  		while (--dstlen >= 0)
  			*dst++ = (ch = *src++) == ':' ? '/' : ch;
  	}
  out:
  	out->len = dst - (char *)out->name;
  	dstlen = HFS_NAMELEN - out->len;
  	while (--dstlen >= 0)
  		*dst++ = 0;
  }