pcfs/fstyp/fstyp.c

	fstyp.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * fstyp
 *
 * Designed to work with block devices (e.g., /dev/diskette), not
 * raw devices (e.g., /dev/rdiskette)
 */
#include <sys/param.h>
#include <sys/types.h>
#include <sys/mntent.h>
#include <errno.h>
#include <sys/fs/pc_fs.h>
#include <sys/fs/pc_label.h>
#include <sys/stat.h>
#include <sys/vfs.h>

#include <stdio.h>
#include <sys/mnttab.h>

#include <locale.h>

extern offset_t llseek();


#define PC_BPSEC(a) ((a[12]<<8)+a[11])  /* bytes per sector */
#define PC_SPC(a)   (a[13])         /* sectors per cluster */
#define PC_RESSEC(a)    ((a[15]<<8)+a[14])  /* reserved sectors */
#define PC_NFAT(a)  (a[16])         /* number of fats */
#define PC_NROOTENT(a)  ((a[18]<<8)+a[17])  /* number of root dir entries */
#define PC_MEDIA(a) (a[21])         /* media descriptor */
#define PC_SPT(a)   ((a[25]<<8)+a[24])  /* sectors per track */
#define PC_NHEAD(a) ((a[27]<<8)+a[26])  /* number of heads */
#define PC_HIDSEC(a)    ((a[29]<<8)+a[28])  /* number of hidden sectors */
#define PC_DRVNUM(a)    (a[36])         /* drive number */
#define PC_LAB_ADDR(a)  (&a[43])        /* addr of volume label */
#define LABEL_SIZE 11               /* size of volume label */

/*
 * Parse out all the following forms as unsigned quantities. It would
 * not be unusual for them to be large enough that the high bit would be
 * set and they would then be misinterpreted as negative quantities.
 *
 * The values are:
 *  number of sectors
 *  big number of sectors (MSDOS4.0 and later)
 *  sectors/FAT
 *  big sectors/FAT (FAT32 only)
 */
#define PC_NSEC(a)  ((unsigned short)((a[20]<<8)+a[19]))
#define PC_BIGNSEC(a)   ((unsigned)((a[35]<<24)+(a[34]<<16)+(a[33]<<8)+a[32]))
#define PC_SPF(a)   ((unsigned short)(a[23]<<8)+a[22])
#define PC_BIGSPF(a)    ((unsigned)((a[39]<<24)+(a[38]<<16)+(a[37]<<8)+a[36]))

/*
 * Boolean macros
 */
#define PC_EXTSIG(a)    (a[38] == 0x29) /* do we have an extended BPB? */
#define PC_EXTSIG32(a)  (a[66] == 0x29) /* do we have FAT32 w/ extended BPB? */

int vflag = 0;      /* verbose output */
int errflag = 0;
extern  int optind;
char    *cbasename;
char    *special;
char    *fstype;

int
main(argc, argv)
    int argc;
    char *argv[];
{
    int c;

    (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
    (void) textdomain(TEXT_DOMAIN);

    cbasename = argv[0];
    while ((c = getopt(argc, argv, "v")) != EOF) {
        switch (c) {

        case 'v':       /* dump super block */
            vflag++;
            break;

        case '?':
            errflag++;
        }
    }
    if (errflag || argc <= optind) {
        usage();
        exit(31+1);
    }
    special = argv[optind];
    dumpfs(special);

    /* NOTREACHED */
}


usage()
{
    (void) fprintf(stderr, gettext("pcfs usage: fstyp [-v] special\n"));
}


dumpfs(name)
    char *name;
{
    char    buf[DEV_BSIZE];
    char    label[LABEL_SIZE+1];
    unsigned char   media;

    close(0);
    if (open(name, 0) != 0) {
        perror(name);
        exit(1);
    }
    llseek(0, (offset_t)0, 0);
    if (read(0, buf, sizeof (buf)) != sizeof (buf)) {

        /*
         * As an fstyp command, this can get called for a device from
         * any filesystem (or for that matter, a bogus device). The
         * read() returns EINVAL when it's not a pcfs. In this case,
         * don't print an error message.
         */
        if (errno != EINVAL) {
            perror(name);
        }
        exit(1);
    }

    media = (unsigned char)PC_MEDIA(buf);
    if (!valid_media(media))
        exit(31+1);
    if (!well_formed(buf))
        exit(31+1);
    printf("%s\n", "pcfs");

    if (!vflag)
        exit(0);

    printf("Bytes Per Sector  %d\t\tSectors Per Cluster    %d\n",
        (unsigned short)PC_BPSEC(buf), (unsigned char)PC_SPC(buf));
    printf("Reserved Sectors  %d\t\tNumber of FATs         %d\n",
        (unsigned short)PC_RESSEC(buf), (unsigned char)PC_NFAT(buf));
    printf("Root Dir Entries  %d\t\tNumber of Sectors      %d\n",
        (unsigned short)PC_NROOTENT(buf), (unsigned short)PC_NSEC(buf));
    printf("Sectors Per FAT   %d\t\tSectors Per Track      %d\n",
        (unsigned short)PC_SPF(buf), (unsigned short)PC_SPT(buf));
    printf("Number of Heads   %d\t\tNumber Hidden Sectors  %d\n",
        (unsigned short)PC_NHEAD(buf), (unsigned short)PC_HIDSEC(buf));
    strncpy(label, PC_LAB_ADDR(buf), LABEL_SIZE);
    label[LABEL_SIZE+1] = 0;
    printf("Volume Label: %s\n", label);
    printf("Drive Number: 0x%x\n", (unsigned char)PC_DRVNUM(buf));
    printf("Media Type: 0x%x   ", media);

    switch (media) {
    case MD_FIXED:
        printf("\"Fixed\" Disk\n");
        break;
    case SS8SPT:
        printf("Single Sided, 8 Sectors Per Track\n");
        break;
    case DS8SPT:
        printf("Double Sided, 8 Sectors Per Track\n");
        break;
    case SS9SPT:
        printf("Single Sided, 9 Sectors Per Track\n");
        break;
    case DS9SPT:
        printf("Double Sided, 9 Sectors Per Track\n");
        break;
    case DS18SPT:
        printf("Double Sided, 18 Sectors Per Track\n");
        break;
    case DS9_15SPT:
        printf("Double Sided, 9-15 Sectors Per Track\n");
        break;
    default:
        printf("Unknown Media Type\n");
    }

    close(0);
    exit(0);
}

valid_media(media_type)
unsigned char media_type;
{
    switch (media_type) {

    case MD_FIXED:
    case SS8SPT:
    case DS8SPT:
    case SS9SPT:
    case DS9SPT:
    case DS18SPT:
    case DS9_15SPT:
        return (1);
    default:
        return (0);
    }
}

well_formed(char bs[])
{
    int fatmatch;

    if (PC_EXTSIG(bs)) {
        fatmatch = ((bs[PCFS_TYPESTRING_OFFSET16] == 'F' &&
            bs[PCFS_TYPESTRING_OFFSET16 + 1] == 'A' &&
            bs[PCFS_TYPESTRING_OFFSET16 + 2] == 'T') &&
            (PC_SPF(bs) > 0) &&
            ((PC_NSEC(bs) == 0 && PC_BIGNSEC(bs) > 0) ||
                PC_NSEC(bs) > 0));
    } else if (PC_EXTSIG32(bs)) {
        fatmatch = ((bs[PCFS_TYPESTRING_OFFSET32] == 'F' &&
            bs[PCFS_TYPESTRING_OFFSET32 + 1] == 'A' &&
            bs[PCFS_TYPESTRING_OFFSET32 + 2] == 'T') &&
            (PC_SPF(bs) == 0 && PC_BIGSPF(bs) > 0) &&
            ((PC_NSEC(bs) == 0 && PC_BIGNSEC(bs) > 0) ||
                PC_NSEC(bs) > 0));
    } else {
        fatmatch = (PC_NSEC(bs) > 0 && PC_SPF(bs) > 0);
    }

    return (fatmatch && PC_BPSEC(bs) > 0 && PC_BPSEC(bs) % 512 == 0 &&
        PC_SPC(bs) > 0 && PC_RESSEC(bs) >= 1 && PC_NFAT(bs) > 0);
}