/*      $OpenBSD: disksubr.c,v 1.91 2022/10/11 23:39:07 krw Exp $       */

/*
 * Copyright (c) 1999 Michael Shalayeff
 * Copyright (c) 1997 Niklas Hallqvist
 * 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     readliflabel(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.
 */
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 = readliflabel(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
readliflabel(struct buf *bp, void (*strat)(struct buf *),
    struct disklabel *lp, daddr_t *partoffp, int spoofonly)
{
        struct lifdir *p;
        struct lifvol *lvp;
        int error = 0;
        daddr_t fsoff = 0, openbsdstart = MAXLIFSPACE;
        int i;

        /* read LIF volume header */
        error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp,
            btodb(LIF_VOLSTART)));
        if (error)
                return (error);

        lvp = (struct lifvol *)bp->b_data;
        if (lvp->vol_id != LIF_VOL_ID) {
                error = EINVAL;         /* no LIF volume header */
                goto done;
        }

        /* read LIF directory */
        error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp,
            lifstodb(lvp->vol_addr)));
        if (error)
                goto done;

        /* scan for LIF_DIR_FS dir entry */
        for (i=0, p=(struct lifdir *)bp->b_data; i < LIF_NUMDIR; p++, i++) {
                if (p->dir_type == LIF_DIR_FS || p->dir_type == LIF_DIR_HPLBL)
                        break;
        }

        if (p->dir_type == LIF_DIR_FS) {
                fsoff = lifstodb(p->dir_addr);
                openbsdstart = 0;
                goto finished;
        }

        /* Only came here to find the offset... */
        if (partoffp)
                goto finished;

        if (p->dir_type == LIF_DIR_HPLBL) {
                struct hpux_label *hl;
                struct partition *pp;
                u_int8_t fstype;
                int i;

                /* read LIF directory */
                error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp,
                    lifstodb(p->dir_addr)));
                if (error)
                        goto done;

                hl = (struct hpux_label *)bp->b_data;
                if (hl->hl_magic1 != hl->hl_magic2 ||
                    hl->hl_magic != HPUX_MAGIC || hl->hl_version != 1) {
                        error = EINVAL;  /* HPUX label magic mismatch */
                        goto done;
                }

                for (i = 0; i < MAXPARTITIONS; i++) {
                        DL_SETPSIZE(&lp->d_partitions[i], 0);
                        DL_SETPOFFSET(&lp->d_partitions[i], 0);
                        lp->d_partitions[i].p_fstype = 0;
                }

                for (i = 0; i < HPUX_MAXPART; i++) {
                        if (!hl->hl_flags[i])
                                continue;
                        if (hl->hl_flags[i] == HPUX_PART_ROOT) {
                                pp = &lp->d_partitions[0];
                                fstype = FS_BSDFFS;
                        } else if (hl->hl_flags[i] == HPUX_PART_SWAP) {
                                pp = &lp->d_partitions[1];
                                fstype = FS_SWAP;
                        } else if (hl->hl_flags[i] == HPUX_PART_BOOT) {
                                pp = &lp->d_partitions[RAW_PART + 1];
                                fstype = FS_BSDFFS;
                        } else
                                continue;

                        DL_SETPSIZE(pp, hl->hl_parts[i].hlp_length * 2);
                        DL_SETPOFFSET(pp, hl->hl_parts[i].hlp_start * 2);
                        pp->p_fstype = fstype;
                }

                DL_SETPSIZE(&lp->d_partitions[RAW_PART], DL_GETDSIZE(lp));
                DL_SETPOFFSET(&lp->d_partitions[RAW_PART], 0);
                lp->d_partitions[RAW_PART].p_fstype = FS_UNUSED;
                lp->d_npartitions = MAXPARTITIONS;
                lp->d_magic = DISKMAGIC;
                lp->d_magic2 = DISKMAGIC;
                lp->d_version = 1;
                lp->d_checksum = 0;
                lp->d_checksum = dkcksum(lp);
                /* drop through */
        }

finished:
        /* record the OpenBSD partition's placement for the caller */
        if (partoffp)
                *partoffp = fsoff;
        else {
                DL_SETBSTART(lp, DL_BLKTOSEC(lp, openbsdstart));
                DL_SETBEND(lp, DL_GETDSIZE(lp));        /* XXX */
        }

        /* don't read the on-disk label if we are in spoofed-only mode */
        if (spoofonly)
                goto done;

        error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp, fsoff +
            LABELSECTOR));
        if (error)
                goto done;

        error = checkdisklabel(bp->b_dev, bp->b_data, lp, openbsdstart,
            DL_GETDSIZE(lp));

done:
        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 (readliflabel(bp, strat, lp, &partoff, 1) == 0) {
                error = readdisksector(bp, strat, lp, DL_BLKTOSEC(lp,
                    partoff + LABELSECTOR));
                offset = LABELOFFSET;
        } 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);
}