/*      $OpenBSD: disksubr.c,v 1.83 2022/10/11 23:39:08 krw Exp $       */
/*      $NetBSD: disksubr.c,v 1.21 1996/05/03 19:42:03 christos Exp $   */

/*
 * Copyright (c) 1996 Theo de Raadt
 * 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. 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/disklabel.h>
#include <sys/disk.h>

int     readdpmelabel(struct buf *, void (*)(struct buf *),
            struct disklabel *, daddr_t *, int);

/*
 * Attempt to read a disk label from a device
 * using the indicated strategy routine.
 * The label must be partly set up before this:
 * secpercyl, secsize and anything required for a block i/o read
 * operation in the driver's strategy/start routines
 * must be filled in before calling us.
 *
 * If dos partition table requested, attempt to load it and
 * find disklabel inside a DOS partition.
 *
 * We would like to check if each MBR has a valid DOSMBR_SIGNATURE, but
 * we cannot because it doesn't always exist. So.. we assume the
 * MBR is valid.
 */
int
readdisklabel(dev_t dev, void (*strat)(struct buf *),
    struct disklabel *lp, int spoofonly)
{
        struct buf *bp = NULL;
        int error;

        if ((error = initdisklabel(lp)))
                goto done;

        /* get a buffer and initialize it */
        bp = geteblk(lp->d_secsize);
        bp->b_dev = dev;

        error = readdpmelabel(bp, strat, lp, NULL, spoofonly);
        if (error == 0)
                goto done;

        error = readdoslabel(bp, strat, lp, NULL, spoofonly);
        if (error == 0)
                goto done;

#if defined(CD9660)
        error = iso_disklabelspoof(dev, strat, lp);
        if (error == 0)
                goto done;
#endif
#if defined(UDF)
        error = udf_disklabelspoof(dev, strat, lp);
        if (error == 0)
                goto done;
#endif

done:
        if (bp) {
                bp->b_flags |= B_INVAL;
                brelse(bp);
        }
        disk_change = 1;
        return (error);
}

int
readdpmelabel(struct buf *bp, void (*strat)(struct buf *),
    struct disklabel *lp, daddr_t *partoffp, int spoofonly)
{
        int error, i, part_cnt, n, hfspartoff = -1;
        long long hfspartend = DL_GETDSIZE(lp);
        struct part_map_entry *part;

        /* First check for a DPME (HFS) disklabel */
        error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp, LABELSECTOR));
        if (error)
                return (error);

        /* if successful, wander through DPME partition table */
        part = (struct part_map_entry *)bp->b_data;
        /* if first partition is not valid, assume not HFS/DPME partitioned */
        if (part->pmSig != PART_ENTRY_MAGIC)
                return (EINVAL);        /* not a DPME partition */
        part_cnt = part->pmMapBlkCnt;
        n = 8;
        for (i = 0; i < part_cnt; i++) {
                struct partition *pp;
                char *s;

                error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp,
                    LABELSECTOR + i));
                if (error)
                        return (error);

                part = (struct part_map_entry *)bp->b_data;
                /* toupper the string, in case caps are different... */
                for (s = part->pmPartType; *s; s++)
                        if ((*s >= 'a') && (*s <= 'z'))
                                *s = (*s - 'a' + 'A');

                if (strcmp(part->pmPartType, PART_TYPE_OPENBSD) == 0) {
                        hfspartoff = part->pmPyPartStart;
                        hfspartend = hfspartoff + part->pmPartBlkCnt;
                        if (partoffp) {
                                *partoffp = hfspartoff;
                                return (0);
                        } else {
                                DL_SETBSTART(lp, hfspartoff);
                                DL_SETBEND(lp,
                                    hfspartend < DL_GETDSIZE(lp) ? hfspartend :
                                    DL_GETDSIZE(lp));
                        }
                        continue;
                }

                if (n >= MAXPARTITIONS || partoffp)
                        continue;

                /* Currently we spoof HFS partitions only. */
                if (strcmp(part->pmPartType, PART_TYPE_MAC) == 0) {
                        pp = &lp->d_partitions[n];
                        DL_SETPOFFSET(pp, part->pmPyPartStart);
                        DL_SETPSIZE(pp, part->pmPartBlkCnt);
                        pp->p_fstype = FS_HFS;
                        n++;
                }

        }

        if (hfspartoff == -1)
                return (EINVAL);        /* no OpenBSD partition inside DPME label */

        if (spoofonly)
                return (0);

        /* next, dig out disk label */
        error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp, hfspartoff));
        if (error)
                return (error);

        error = checkdisklabel(bp->b_dev, bp->b_data + LABELOFFSET, lp,
            hfspartoff, hfspartend);

        return (error);
}

/*
 * Write disk label back to device after modification.
 */
int
writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp)
{
        daddr_t partoff = -1;
        int error = EIO;
        int offset;
        struct disklabel *dlp;
        struct buf *bp = NULL;

        /* get a buffer and initialize it */
        bp = geteblk(lp->d_secsize);
        bp->b_dev = dev;

        /* Read it in, slap the new label in, and write it back out */
        if (readdpmelabel(bp, strat, lp, &partoff, 1) == 0) {
                error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp, partoff));
                offset = 0;
        } else if (readdoslabel(bp, strat, lp, &partoff, 1) == 0) {
                error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp,
                    partoff + DOS_LABELSECTOR));
                offset = DL_BLKOFFSET(lp, partoff + DOS_LABELSECTOR);
        } else
                goto done;

        if (error)
                goto done;

        dlp = (struct disklabel *)(bp->b_data + offset);
        *dlp = *lp;
        CLR(bp->b_flags, B_READ | B_WRITE | B_DONE);
        SET(bp->b_flags, B_BUSY | B_WRITE | B_RAW);
        (*strat)(bp);
        error = biowait(bp);

done:
        if (bp) {
                bp->b_flags |= B_INVAL;
                brelse(bp);
        }
        disk_change = 1;
        return (error);
}