trans.c

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/*
 *  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;
}