boot-132.tar.gz

[apple/boot.git] / i386 / libsaio / ntfs.c

/*
 * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2004 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

#include "libsaio.h"
#include "sl.h"

#define BYTE_ORDER_MARK	0xFEFF

#include "ntfs_private.h"

#define FS_TYPE			"ntfs"
#define FS_NAME_FILE		"NTFS"

#define MAX_BLOCK_SIZE		2048
#define MAX_CLUSTER_SIZE	32768

#define LABEL_LENGTH	1024
#define UNKNOWN_LABEL	"Untitled NTFS"

#define FSUR_IO_FAIL -1
#define FSUR_UNRECOGNIZED -1
#define FSUR_RECOGNIZED 0

#define ERROR -1

/*
 * Process per-sector "fixups" that NTFS uses to detect corruption of
 * multi-sector data structures, like MFT records.
 */
static int
ntfs_fixup(
            char *buf,
            size_t len,
            u_int32_t magic,
            u_int32_t bytesPerSector)
{
	struct fixuphdr *fhp = (struct fixuphdr *) buf;
	int             i;
	u_int16_t       fixup;
	u_int16_t      *fxp;
	u_int16_t      *cfxp;
        u_int32_t	fixup_magic;
        u_int16_t	fixup_count;
        u_int16_t	fixup_offset;
        
        fixup_magic = OSReadLittleInt32(&fhp->fh_magic,0);
	if (fixup_magic != magic) {
		error("ntfs_fixup: magic doesn't match: %08x != %08x\n",
		       fixup_magic, magic);
		return (ERROR);
	}
        fixup_count = OSReadLittleInt16(&fhp->fh_fnum,0);
	if ((fixup_count - 1) * bytesPerSector != len) {
		error("ntfs_fixup: " \
		       "bad fixups number: %d for %ld bytes block\n", 
		       fixup_count, (long)len);	/* XXX printf kludge */
		return (ERROR);
	}
        fixup_offset = OSReadLittleInt16(&fhp->fh_foff,0);
	if (fixup_offset >= len) {
		error("ntfs_fixup: invalid offset: %x", fixup_offset);
		return (ERROR);
	}
	fxp = (u_int16_t *) (buf + fixup_offset);
	cfxp = (u_int16_t *) (buf + bytesPerSector - 2);
	fixup = *fxp++;
	for (i = 1; i < fixup_count; i++, fxp++) {
		if (*cfxp != fixup) {
			error("ntfs_fixup: fixup %d doesn't match\n", i);
			return (ERROR);
		}
		*cfxp = *fxp;
                cfxp = (u_int16_t *)(((caddr_t)cfxp) + bytesPerSector);
	}
	return (0);
}

/*
 * Find a resident attribute of a given type.  Returns a pointer to the
 * attribute data, and its size in bytes.
 */
static int
ntfs_find_attr(
                char *buf,
                u_int32_t attrType,
                void **attrData,
                size_t *attrSize)
{
    struct filerec *filerec;
    struct attr *attr;
    u_int16_t offset;
    
    filerec = (struct filerec *) buf;
    offset = OSReadLittleInt16(&filerec->fr_attroff,0);
    attr = (struct attr *) (buf + offset);