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/*
* Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* 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 <stdio.h>
#include <stdlib.h>
#include <sys/disk.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <sys/stat.h>
/* copied from diskdev_cmds/fsck_msdos/dosfs.h */
#define DOSBOOTBLOCKSIZE 512
#define MAX_SECTOR_SIZE 4096
#define E_OPENDEV -1
#define E_READ -5
void usage(void);
char *rawname(char *name);
char *unrawname(char *name);
int checkVolHdr(const unsigned char *volhdr);
char *blockcheck(char *origname);
char *progname;
/*
* prefer to use raw device. TODO: suppose block device is valid but
* the corresponding raw device is not valid, then we fail. this is
* probably no the desired behavior.
*/
int
main(int argc, char **argv)
{
unsigned char volhdr[MAX_SECTOR_SIZE] = {0};
int fd, retval;
char *devname;
fd = -1;
retval = 0;
if ((progname = strrchr(*argv, '/')))
++progname;
else
progname = *argv;
if (argc != 2) {
usage();
} else {
devname = blockcheck(argv[1]);
if (devname != NULL) {
if ((fd = open(devname, O_RDONLY, 0)) < 0) {
retval = E_OPENDEV;
} else if (read(fd, volhdr, MAX_SECTOR_SIZE) != MAX_SECTOR_SIZE) {
retval = E_READ;
} else {
retval = checkVolHdr(volhdr);
}
if (-1 != fd) {
close(fd);
fd = -1;
}
}
}
return retval;
}
void
usage(void)
{
fprintf(stdout, "usage: %s device\n", progname);
return;
}
/* copied from diskdev_cmds/fsck_hfs/utilities.c */
char *
rawname(char *name)
{
static char rawbuf[32];
char *dp;
if ((dp = strrchr(name, '/')) == 0)
return (0);
*dp = 0;
(void) strlcpy(rawbuf, name, sizeof(rawbuf));
*dp = '/';
(void) strlcat(rawbuf, "/r", sizeof(rawbuf));
(void) strlcat(rawbuf, &dp[1], sizeof(rawbuf));
return (rawbuf);
}
/* copied from diskdev_cmds/fsck_hfs/utilities.c */
char *
unrawname(char *name)
{
char *dp;
struct stat stb;
size_t dp_len;
if ((dp = strrchr(name, '/')) == 0)
return (name);
if (stat(name, &stb) < 0)
return (name);
if ((stb.st_mode & S_IFMT) != S_IFCHR)
return (name);
if (dp[1] != 'r')
return (name);
dp_len = strlen(&dp[2]) + 1;
(void)memmove(&dp[1], &dp[2], dp_len);
return (name);
}
/*
* copied from diskdev_cmds/fsck_hfs/utilities.c, and modified:
* 1) remove "hotroot"
* 2) if error, return NULL
* 3) if not a char device, return NULL (effectively, this is treated
* as error even if accessing the block device might have been OK)
*/
char *
blockcheck(char *origname)
{
struct stat stblock, stchar;
char *newname, *raw;
int retried;
retried = 0;
newname = origname;
retry:
if (stat(newname, &stblock) < 0) {
perror(newname);
fprintf(stderr, "Can't stat %s\n", newname);
return NULL;
}
if ((stblock.st_mode & S_IFMT) == S_IFBLK) {
raw = rawname(newname);
if (stat(raw, &stchar) < 0) {
perror(raw);
fprintf(stderr, "Can't stat %s\n", raw);
return NULL;
}
if ((stchar.st_mode & S_IFMT) == S_IFCHR) {
return (raw);
} else {
fprintf(stderr, "%s is not a character device\n", raw);
return NULL;
}
} else if ((stblock.st_mode & S_IFMT) == S_IFCHR && !retried) {
newname = unrawname(newname);
retried++;
goto retry;
}
/* not a block or character device */
return NULL;
}
/*
* (sanity) check the volume header in volhdr
*
* return 1 if volhdr is a FAT volhdr, 0 otherwise
*/
int
checkVolHdr(const unsigned char *volhdr)
{
/* NTFS volumes have an OEMid of NTFS followed by four spaces. */
const char *ntfs_oemid = "NTFS ";
int retval;
retval = 1;
/* copied from diskdev_cmds/fsck_msdos/boot.c */
/*
* [2699033]
*
* The first three bytes are an Intel x86 jump instruction. It should
* be one of the following forms: 0xE9 0x?? 0x?? 0xEC 0x?? 0x90 where
* 0x?? means any byte value is OK.
*/
if (volhdr[0] != 0xE9 && (volhdr[0] != 0xEB || volhdr[2] != 0x90)) {
retval = 0;
}
if (!memcmp(ntfs_oemid, volhdr + 3, 8))
retval = 0;
return retval;
}
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