// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) International Business Machines Corp., 2000-2004
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include "jfs_incore.h"
#include "jfs_filsys.h"
#include "jfs_unicode.h"
#include "jfs_debug.h"

/*
 * NAME:        jfs_strfromUCS()
 *
 * FUNCTION:    Convert little-endian unicode string to character string
 *
 */
int jfs_strfromUCS_le(char *to, const __le16 * from,
                      int len, struct nls_table *codepage)
{
        int i;
        int outlen = 0;
        static int warn_again = 5;      /* Only warn up to 5 times total */
        int warn = !!warn_again;        /* once per string */

        if (codepage) {
                for (i = 0; (i < len) && from[i]; i++) {
                        int charlen;
                        charlen =
                            codepage->uni2char(le16_to_cpu(from[i]),
                                               &to[outlen],
                                               NLS_MAX_CHARSET_SIZE);
                        if (charlen > 0)
                                outlen += charlen;
                        else
                                to[outlen++] = '?';
                }
        } else {
                for (i = 0; (i < len) && from[i]; i++) {
                        if (unlikely(le16_to_cpu(from[i]) & 0xff00)) {
                                to[i] = '?';
                                if (unlikely(warn)) {
                                        warn--;
                                        warn_again--;
                                        printk(KERN_ERR
                        "non-latin1 character 0x%x found in JFS file name\n",
                                               le16_to_cpu(from[i]));
                                        printk(KERN_ERR
                                "mount with iocharset=utf8 to access\n");
                                }

                        }
                        else
                                to[i] = (char) (le16_to_cpu(from[i]));
                }
                outlen = i;
        }
        to[outlen] = 0;
        return outlen;
}

/*
 * NAME:        jfs_strtoUCS()
 *
 * FUNCTION:    Convert character string to unicode string
 *
 */
static int jfs_strtoUCS(wchar_t * to, const unsigned char *from, int len,
                struct nls_table *codepage)
{
        int charlen;
        int i;

        if (codepage) {
                for (i = 0; len && *from; i++, from += charlen, len -= charlen)
                {
                        charlen = codepage->char2uni(from, len, &to[i]);
                        if (charlen < 1) {
                                jfs_err("jfs_strtoUCS: char2uni returned %d.",
                                        charlen);
                                jfs_err("charset = %s, char = 0x%x",
                                        codepage->charset, *from);
                                return charlen;
                        }
                }
        } else {
                for (i = 0; (i < len) && from[i]; i++)
                        to[i] = (wchar_t) from[i];
        }

        to[i] = 0;
        return i;
}

/*
 * NAME:        get_UCSname()
 *
 * FUNCTION:    Allocate and translate to unicode string
 *
 */
int get_UCSname(struct component_name * uniName, struct dentry *dentry)
{
        struct nls_table *nls_tab = JFS_SBI(dentry->d_sb)->nls_tab;
        int length = dentry->d_name.len;

        if (length > JFS_NAME_MAX)
                return -ENAMETOOLONG;

        uniName->name =
            kmalloc_array(length + 1, sizeof(wchar_t), GFP_NOFS);

        if (uniName->name == NULL)
                return -ENOMEM;

        uniName->namlen = jfs_strtoUCS(uniName->name, dentry->d_name.name,
                                       length, nls_tab);

        if (uniName->namlen < 0) {
                kfree(uniName->name);
                return uniName->namlen;
        }

        return 0;
}