source: mainline/uspace/srv/fs/exfat/exfat_dentry.c

/*
 * Copyright (c) 2011 Oleg Romanenko
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup exfat
 * @{
 */

/**
 * @file        exfat_dentry.c
 * @brief       Functions that work with exFAT directory entries.
 */

#include "exfat_dentry.h"
#include <ctype.h>
#include <str.h>
#include <errno.h>
#include <byteorder.h>
#include <assert.h>

exfat_dentry_clsf_t exfat_classify_dentry(const exfat_dentry_t *d)
{
        switch (d->type) {
        case EXFAT_TYPE_VOLLABEL:
                return EXFAT_DENTRY_VOLLABEL;
        case EXFAT_TYPE_BITMAP:
                return EXFAT_DENTRY_BITMAP;
        case EXFAT_TYPE_UCTABLE:
                return EXFAT_DENTRY_UCTABLE;
        case EXFAT_TYPE_GUID:
                return EXFAT_DENTRY_GUID;
        case EXFAT_TYPE_FILE:
                return EXFAT_DENTRY_FILE;
        case EXFAT_TYPE_STREAM:
                return EXFAT_DENTRY_STREAM;
        case EXFAT_TYPE_NAME:
                return EXFAT_DENTRY_NAME;
        case EXFAT_TYPE_UNUSED:
                return EXFAT_DENTRY_LAST;
        default:
                if (d->type & EXFAT_TYPE_USED)
                        return EXFAT_DENTRY_SKIP;
                else
                        return EXFAT_DENTRY_FREE;
        }
}

uint16_t exfat_name_hash(const uint16_t *name, const uint16_t *uctable, size_t chars)
{
        uint16_t hash = 0;
        uint16_t ch;
        while (*name) {
                if (*name < chars)
                        ch = uint16_t_le2host(uctable[*name]);
                else
                        ch = *name;
                name++;

                hash = ((hash << 15) | (hash >> 1)) + (ch & 0xff);
                hash = ((hash << 15) | (hash >> 1)) + (ch >> 8);
        }

        return hash;
}

void exfat_dentry_get_name(const exfat_name_dentry_t *name, size_t size, uint16_t *dst, size_t *offset)
{
        size_t i = 0;
        while (i < EXFAT_NAME_PART_LEN && *offset < size) {
                dst[*offset] = uint16_t_le2host(name->name[i]);
                i++;
                (*offset)++;
        }
        dst[*offset] = '\0';
}

void exfat_dentry_get_vollabel(const exfat_vollabel_dentry_t *vollabel,
    size_t size, uint16_t *dst)
{
        size_t i = 0;
        while (i < EXFAT_VOLLABEL_LEN && i < vollabel->size && i < size) {
                dst[i] = uint16_t_le2host(vollabel->label[i]);
                i++;
        }
        dst[i] = '\0';
}

bool exfat_valid_char(char32_t ch)
{
        if (ch >= 0x01 && ch <= 0x1F)
                return false;

        switch (ch) {
        case '/':
        case '\\':
        case '?':
        case '|':
        case '>':
        case '<':
        case '"':
        case '*':
        case ':':
                return false;
        default:
                return true;
        }
}

bool exfat_valid_name(const char *name)
{
        size_t off = 0;
        char32_t ch;

        while ((ch = str_decode(name, &off, STR_NO_LIMIT)) != 0) {
                if (!exfat_valid_char(ch))
                        return false;
        }
        return true;
}

/**
 * @}
 */