freebsd-skq/sys/kern/subr_diskmbr.c

/*-
 * Copyright (c) 1994 Bruce D. Evans.
 * All rights reserved.
 *
 * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *	from: @(#)ufs_disksubr.c	7.16 (Berkeley) 5/4/91
 *	from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $
 *	$Id: diskslice_machdep.c,v 1.6 1995/02/22 22:46:36 bde Exp $
 */

#include <stddef.h>
#include <sys/param.h>
#include <sys/buf.h>
#include <sys/disklabel.h>
#define	DOSPTYP_EXTENDED	5
#include <sys/diskslice.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <sys/systm.h>

#define TRACE(str)	do { if (dsi_debug) printf str; } while (0)

static volatile u_char dsi_debug;

static int check_part __P((char *sname, struct dos_partition *dp,
			   u_long offset, int nsectors, int ntracks));
static void extended __P((char *dname, dev_t dev, d_strategy_t *strat,
			  struct disklabel *lp, struct diskslices *ssp,
			  u_long ext_offset, u_long ext_size,
			  u_long base_ext_offset, int nsectors, int ntracks));

static int
check_part(sname, dp, offset, nsectors, ntracks)
	char	*sname;
	struct dos_partition *dp;
	u_long	offset;
	int	nsectors;
	int	ntracks;
{
	int	error;
	u_long	esector;
	u_long	esector1;
	u_long	secpercyl;
	u_long	ssector;
	u_long	ssector1;

	secpercyl = (u_long)nsectors * ntracks;
	ssector = DPSECT(dp->dp_ssect) - 1 + dp->dp_shd * nsectors
		  + DPCYL(dp->dp_scyl, dp->dp_ssect) * secpercyl;
	ssector1 = offset + dp->dp_start;
	esector = DPSECT(dp->dp_esect) - 1 + dp->dp_ehd * nsectors
		  + DPCYL(dp->dp_ecyl, dp->dp_esect) * secpercyl;
	esector1 = ssector1 + dp->dp_size - 1;
	error = ssector == ssector1 && esector == esector1 ? 0 : EINVAL;
	printf("%s: start %lu, end = %lu, size %lu%s\n",
	       sname, ssector, esector, dp->dp_size, error ? "" : ": OK");
	if (ssector != ssector1)
		printf("%s: C/H/S start %lu != start %lu: invalid\n",
		       sname, ssector, ssector1);
	if (esector != esector1)
		printf("%s: C/H/S end %lu != end %lu: invalid\n",
		       sname, esector, esector1);
	return (error);
}

int
dsinit(dname, dev, strat, lp, sspp)
	char	*dname;
	dev_t	dev;
	d_strategy_t *strat;
	struct disklabel *lp;
	struct diskslices **sspp;
{
	struct buf *bp;
	u_char	*cp;
	int	dospart;
	struct dos_partition *dp;
	struct dos_partition *dp0;
	int	error;
	int	max_ncyls;
	int	max_nsectors;
	int	max_ntracks;
	char	partname[2];
	u_long	secpercyl;
	int	slice;
	char	*sname;
	struct diskslice *sp;
	struct diskslices *ssp;

	/*
	 * Allocate a dummy slices "struct" and initialize it to contain
	 * only an empty compatibility slice (pointing to itself) and a
	 * whole disk slice (covering the disk as described by the label).
	 * If there is an error, then the dummy struct becomes final.
	 */
	ssp = malloc(offsetof(struct diskslices, dss_slices)
		     + BASE_SLICE * sizeof *sp, M_DEVBUF, M_WAITOK);
	*sspp = ssp;
	ssp->dss_first_bsd_slice = COMPATIBILITY_SLICE;
	ssp->dss_nslices = BASE_SLICE;
	sp = &ssp->dss_slices[0];
	bzero(sp, BASE_SLICE * sizeof *sp);
	sp[WHOLE_DISK_SLICE].ds_size = lp->d_secperunit;

	/* Read master boot record. */
	bp = geteblk((int)lp->d_secsize);
	bp->b_dev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
	bp->b_blkno = DOSBBSECTOR;
	bp->b_bcount = lp->d_secsize;
	bp->b_flags = B_BUSY | B_READ;
	(*strat)(bp);
	if (biowait(bp) != 0) {
		diskerr(bp, dname, "error reading partition table",
			LOG_PRINTF, 0, lp);
		printf("\n");
		error = EIO;
		goto done;
	}

	/* Weakly verify it. */
	cp = bp->b_un.b_addr;
	if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
		diskerr(bp, dname, "invalid partition table",
			LOG_PRINTF, 0, lp);
		printf("\n");
		error = EINVAL;
		goto done;
	}

	/* Guess the geometry. */
	/*
	 * TODO:
	 * Perhaps skip entries with 0 size.
	 * Perhaps only look at entries of type DOSPTYP_386BSD.
	 */
	max_ncyls = 0;
	max_nsectors = 0;
	max_ntracks = 0;
	dp0 = (struct dos_partition *)(cp + DOSPARTOFF);
	for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
		int	nsectors;
		int	ntracks;

		max_ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect);
		if (max_ncyls < max_ncyls)
			max_ncyls = max_ncyls;
		nsectors = DPSECT(dp->dp_esect);
		if (max_nsectors < nsectors)
			max_nsectors = nsectors;
		ntracks = dp->dp_ehd + 1;
		if (max_ntracks < ntracks)
			max_ntracks = ntracks;
	}

	/* Check the geometry. */
	/*
	 * TODO:
	 * As above.
	 * Check for overlaps.
	 * Check against d_secperunit if the latter is reliable.
	 */
	error = 0;
	secpercyl = (u_long)max_nsectors * max_ntracks;
	for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
		if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
		    && dp->dp_start == 0 && dp->dp_size == 0)
			continue;
		sname = dsname(dname, dkunit(dev), BASE_SLICE + dospart,
			       RAW_PART, partname);

		/*
		 * Temporarily ignore errors from this check.  We could
		 * simplify things by accepting the table eariler if we
		 * always ignore errors here.  Perhaps we should always
		 * accept the table if the magic is right but not let
		 * bad entries affect the geometry.
		 */
		check_part(sname, dp, (u_long)0, max_nsectors, max_ntracks);
	}
	if (error != 0)
		goto done;

	/*
	 * Accept the DOS partition table.
	 * First adjust the label (we have been careful not to change it
	 * before we can guarantee success).
	 */
	if (secpercyl != 0) {
		u_long	secperunit;

		lp->d_nsectors = max_nsectors;
		lp->d_ntracks = max_ntracks;
		lp->d_secpercyl = secpercyl;
		secperunit = secpercyl * max_ncyls;
		if (lp->d_secperunit < secperunit)
			lp->d_secperunit = secperunit;
	}

	/*
	 * Free the dummy slices "struct" and allocate a real new one.
	 * Initialize special slices as above.
	 */
	free(ssp, M_DEVBUF);
	ssp = malloc(offsetof(struct diskslices, dss_slices)
#define	MAX_SLICES_SUPPORTED	MAX_SLICES  /* was (BASE_SLICE + NDOSPART) */
		     + MAX_SLICES_SUPPORTED * sizeof *sp, M_DEVBUF, M_WAITOK);
	*sspp = ssp;
	ssp->dss_first_bsd_slice = COMPATIBILITY_SLICE;
	sp = &ssp->dss_slices[0];
	bzero(sp, MAX_SLICES_SUPPORTED * sizeof *sp);
	sp[WHOLE_DISK_SLICE].ds_size = lp->d_secperunit;

	/* Initialize normal slices. */
	sp += BASE_SLICE;
	for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) {
		sp->ds_offset = dp->dp_start;
		sp->ds_size = dp->dp_size;
		sp->ds_type = dp->dp_typ;
#if 0
		lp->d_subtype |= (lp->d_subtype & 3) | dospart
				 | DSTYPE_INDOSPART;
#endif
	}
	ssp->dss_nslices = BASE_SLICE + NDOSPART;

	/* Handle extended partitions. */
	sp -= NDOSPART;
	for (dospart = 0; dospart < NDOSPART; dospart++, sp++)
		if (sp->ds_type == DOSPTYP_EXTENDED)
			extended(dname, bp->b_dev, strat, lp, ssp,
				 sp->ds_offset, sp->ds_size, sp->ds_offset,
				 max_nsectors, max_ntracks);

done:
	bp->b_flags = B_INVAL | B_AGE;
	brelse(bp);
	if (error == EINVAL)
		error = 0;
	return (error);
}

void
extended(dname, dev, strat, lp, ssp, ext_offset, ext_size, base_ext_offset,
	 nsectors, ntracks)
	char	*dname;
	dev_t	dev;
	struct disklabel *lp;
	d_strategy_t *strat;
	struct diskslices *ssp;
	u_long	ext_offset;
	u_long	ext_size;
	u_long	base_ext_offset;
	int	nsectors;
	int	ntracks;
{
	struct buf *bp;
	u_char	*cp;
	int	dospart;
	struct dos_partition *dp;
	int	end_slice;
	u_long	ext_offsets[NDOSPART];
	u_long	ext_sizes[NDOSPART];
	char	partname[2];
	int	slice;
	char	*sname;
	struct diskslice *sp;

	/* Read extended boot record. */
	bp = geteblk((int)lp->d_secsize);
	bp->b_dev = dev;
	bp->b_blkno = ext_offset;
	bp->b_bcount = lp->d_secsize;
	bp->b_flags = B_BUSY | B_READ;
	(*strat)(bp);
	if (biowait(bp) != 0) {
		diskerr(bp, dname, "error reading extended partition table",
			LOG_PRINTF, 0, lp);
		printf("\n");
		return;
	}

	/* Weakly verify it. */
	cp = bp->b_un.b_addr;
	if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
		diskerr(bp, dname, "invalid extended partition table",
			LOG_PRINTF, 0, lp);
		printf("\n");
		return;
	}

	for (dospart = 0,
	     dp = (struct dos_partition *)(bp->b_un.b_addr + DOSPARTOFF),
	     slice = ssp->dss_nslices, sp = &ssp->dss_slices[slice];
	     dospart < NDOSPART; dospart++, dp++) {
		ext_sizes[dospart] = 0;
		if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
		    && dp->dp_start == 0 && dp->dp_size == 0)
			continue;
		if (dp->dp_typ == DOSPTYP_EXTENDED) {
			char buf[32];

			sname = dsname(dname, dkunit(dev), WHOLE_DISK_SLICE,
				       RAW_PART, partname);
			strcpy(buf, sname);
			if (strlen(buf) < sizeof buf - 11)
				strcat(buf, "<extended>");
			check_part(buf, dp, base_ext_offset, nsectors,
				   ntracks);
			ext_offsets[dospart] = base_ext_offset + dp->dp_start;
			ext_sizes[dospart] = dp->dp_size;
		} else {
			sname = dsname(dname, dkunit(dev), slice, RAW_PART,
				       partname);
			check_part(sname, dp, ext_offset, nsectors, ntracks);
			if (slice >= MAX_SLICES) {
				printf("%s: too many slices\n", sname);
				slice++;
				continue;
			}
			sp->ds_offset = ext_offset + dp->dp_start;
			sp->ds_size = dp->dp_size;
			sp->ds_type = dp->dp_typ;
			ssp->dss_nslices++;
			slice++;
			sp++;
		}
	}

	/* If we found any more slices, recursively find all the subslices. */
	for (dospart = 0; dospart < NDOSPART; dospart++)
		if (ext_sizes[dospart] != 0)
			extended(dname, dev, strat, lp, ssp,
				 ext_offsets[dospart], ext_sizes[dospart],
				 base_ext_offset, nsectors, ntracks);
}