/*      $NetBSD: disksubr.c,v 1.19 2026/07/03 21:36:27 thorpej Exp $ */

/*
 * 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.
 */

/*
 * Copyright (c) 1994, 1995 Gordon W. Ross
 * Copyright (c) 1994 Theo de Raadt
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: disksubr.c,v 1.19 2026/07/03 21:36:27 thorpej Exp $");

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

#include <dev/sun/disklabel.h>

#if LABELSECTOR != 0
#error  "Default value of LABELSECTOR no longer zero?"
#endif

static  const char *disklabel_sun_to_bsd(char *, struct disklabel *);
static  int disklabel_bsd_to_sun(struct disklabel *, char *);

/*
 * 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.
 *
 * Return buffer for use in signalling errors if requested.
 *
 * Returns null on success and an error string on failure.
 */
const char *
readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, struct cpu_disklabel *clp)
{
        struct buf *bp;
        struct disklabel *dlp;
        struct sun_disklabel *slp;
        int error;

        /* minimal requirements for archetypal disk label */
        if (lp->d_secperunit == 0)
                lp->d_secperunit = 0x1fffffff;
        if (lp->d_npartitions == 0) {
                lp->d_npartitions = RAW_PART + 1;
                if (lp->d_partitions[RAW_PART].p_size == 0)
                        lp->d_partitions[RAW_PART].p_size = 0x1fffffff;
                lp->d_partitions[RAW_PART].p_offset = 0;
        }
        if (lp->d_secsize == 0)
                return ("sector size 0");

        /* obtain buffer to probe drive with */
        bp = geteblk((int)lp->d_secsize);

        /* next, dig out disk label */
        bp->b_dev = dev;
        bp->b_blkno = LABELSECTOR;
        bp->b_cylinder = 0;
        bp->b_bcount = lp->d_secsize;
        bp->b_flags |= B_READ;
        (*strat)(bp);

        /* if successful, locate disk label within block and validate */
        error = biowait(bp);
        if (error == 0) {
                /* Save the whole block in case it has info we need. */
                memcpy(clp->cd_block, bp->b_data, sizeof(clp->cd_block));
        }
        brelse(bp, 0);
        if (error)
                return ("disk label read error");

        /* Check for a NetBSD disk label at LABELOFFSET */
        dlp = (struct disklabel *) (clp->cd_block + LABELOFFSET);
        if (dlp->d_magic == DISKMAGIC) {
                if (dkcksum(dlp))
                        return ("NetBSD disk label corrupted");
                *lp = *dlp;
                return (NULL);
        }

        /* Check for a Sun disk label (for PROM compatibility). */
        slp = (struct sun_disklabel *) clp->cd_block;
        if (slp->sl_magic == SUN_DKMAGIC)
                return (disklabel_sun_to_bsd(clp->cd_block, lp));

        /*
         * Check for a NetBSD disk label somewhere in LABELSECTOR
         * (compat with others big-endian boxes)
         */
        for (dlp = (struct disklabel *)clp->cd_block;
            dlp <= (struct disklabel *)((char *)clp->cd_block +
            DEV_BSIZE - sizeof(*dlp));
            dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
                if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
                        continue;
                }
                if (dlp->d_npartitions > MAXPARTITIONS || dkcksum(dlp) != 0)
                        return("NetBSD disk label corrupted");
                else {
                        *lp = *dlp;
                        return(NULL);
                }
        }

        memset(clp->cd_block, 0, sizeof(clp->cd_block));
        return NULL;
}

/*
 * Write disk label back to device after modification.
 * Current label is already in clp->cd_block[]
 */
int
writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, struct cpu_disklabel *clp)
{
        struct buf *bp;
        int error;
        struct disklabel *dlp;
        struct sun_disklabel *slp;

        /*
         * Embed native label in a piece of wasteland.
         */
        if (sizeof(struct disklabel) > sizeof slp->sl_bsdlabel)
                return EFBIG;

        slp = (struct sun_disklabel *)clp->cd_block;
        memset(slp->sl_bsdlabel, 0, sizeof(slp->sl_bsdlabel));
        dlp = (struct disklabel *)slp->sl_bsdlabel;
        *dlp = *lp;

        /* Build a SunOS compatible label around the native label */
        error = disklabel_bsd_to_sun(lp, clp->cd_block);
        if (error)
                return (error);

        /* Get a buffer and copy the new label into it. */
        bp = geteblk((int)lp->d_secsize);
        memcpy(bp->b_data, clp->cd_block, sizeof(clp->cd_block));

        /* Write out the updated label. */
        bp->b_dev = dev;
        bp->b_blkno = LABELSECTOR;
        bp->b_cylinder = 0;
        bp->b_bcount = lp->d_secsize;
        bp->b_flags |= B_WRITE;
        (*strat)(bp);
        error = biowait(bp);
        brelse(bp, 0);

        return (error);
}

/************************************************************************
 *
 * The rest of this was taken from arch/sparc/scsi/sun_disklabel.c
 * and then substantially rewritten by Gordon W. Ross
 *
 ************************************************************************/

/* What partition types to assume for Sun disklabels: */
static u_char
sun_fstypes[8] = {
        FS_BSDFFS,      /* a */
        FS_SWAP,        /* b */
        FS_OTHER,       /* c - whole disk */
        FS_BSDFFS,      /* d */
        FS_BSDFFS,      /* e */
        FS_BSDFFS,      /* f */
        FS_BSDFFS,      /* g */
        FS_BSDFFS,      /* h */
};

/*
 * Given a SunOS disk label, set lp to a BSD disk label.
 * Returns NULL on success, else an error string.
 *
 * The BSD label is cleared out before this is called.
 */
static const char *
disklabel_sun_to_bsd(char *cp, struct disklabel *lp)
{
        struct sun_disklabel *sl;
        struct partition *npp;
        struct sun_dkpart *spp;
        int i, secpercyl;
        unsigned int secpblck;
        u_short cksum, *sp1, *sp2;

        sl = (struct sun_disklabel *)cp;

        /* Verify the XOR check. */
        sp1 = (u_short *)sl;
        sp2 = (u_short *)(sl + 1);
        cksum = 0;
        while (sp1 < sp2)
                cksum ^= *sp1++;
        if (cksum != 0)
                return("SunOS disk label, bad checksum");

        /* Format conversion. */
        lp->d_magic = DISKMAGIC;
        lp->d_magic2 = DISKMAGIC;
        memcpy(lp->d_packname, sl->sl_text, sizeof(lp->d_packname));

        secpblck = lp->d_secsize / 512;
        if (secpblck == 0) secpblck = 1; /* can't happen */
        lp->d_secsize = 512;
        lp->d_nsectors   = sl->sl_nsectors;
        lp->d_ntracks    = sl->sl_ntracks;
        lp->d_ncylinders = sl->sl_ncylinders;

        secpercyl = sl->sl_nsectors * sl->sl_ntracks;
        lp->d_secpercyl  = secpercyl;
        lp->d_secperunit = secpercyl * sl->sl_ncylinders;

        lp->d_sparespercyl = sl->sl_sparespercyl;
        lp->d_acylinders   = sl->sl_acylinders;
        lp->d_rpm          = sl->sl_rpm;
        lp->d_interleave   = sl->sl_interleave;

        lp->d_npartitions = 8;
        /* These are as defined in <ufs/ffs/fs.h> */
        lp->d_bbsize = 8192;    /* XXX */
        lp->d_sbsize = 8192;    /* XXX */

        for (i = 0; i < 8; i++) {
                spp = &sl->sl_part[i];
                npp = &lp->d_partitions[i];

                if (npp->p_fstype == FS_ISO9660
                    && spp->sdkp_cyloffset * secpercyl == npp->p_offset*secpblck
                    && spp->sdkp_nsectors <= npp->p_size*secpblck
                    && npp->p_size > 0 && spp->sdkp_nsectors > 0) {
                        /*
                         * This happens for example on sunlabel'd hybrid
                         * (ffs + ISO9660) CDs, like our install CDs.
                         * The cd driver has initialized a valid ISO9660
                         * partition (including session parameters), so
                         * we better not overwrite it.
                         */
                        npp->p_offset *= secpblck;
                        npp->p_size = spp->sdkp_nsectors;
                        npp->p_cdsession *= secpblck;
                        continue;
                }
                npp->p_offset = spp->sdkp_cyloffset * secpercyl;
                npp->p_size = spp->sdkp_nsectors;
                if (npp->p_size == 0) {
                        npp->p_fstype = FS_UNUSED;
                } else {
                        npp->p_fstype = sun_fstypes[i];
                        if (npp->p_fstype == FS_BSDFFS) {
                                /*
                                 * The sun label does not store the FFS fields,
                                 * so just set them with default values here.
                                 */
                                npp->p_fsize = 1024;
                                npp->p_frag = 8;
                                npp->p_cpg = 16;
                        }
                }
        }

        lp->d_checksum = 0;
        lp->d_checksum = dkcksum(lp);
        return (NULL);
}

/*
 * Given a BSD disk label, update the Sun disklabel
 * pointed to by cp with the new info.  Note that the
 * Sun disklabel may have other info we need to keep.
 * Returns zero or error code.
 */
static int
disklabel_bsd_to_sun(struct disklabel *lp, char *cp)
{
        struct sun_disklabel *sl;
        struct partition *npp;
        struct sun_dkpart *spp;
        int i, secpercyl;
        u_short cksum, *sp1, *sp2;

        if (lp->d_secsize != 512)
                return (EINVAL);

        sl = (struct sun_disklabel *)cp;

        /*
         * Format conversion.
         */
        memcpy(sl->sl_text, lp->d_packname, sizeof(lp->d_packname));
        sl->sl_rpm = lp->d_rpm;
        sl->sl_pcylinders   = lp->d_ncylinders + lp->d_acylinders; /* XXX */
        sl->sl_sparespercyl = lp->d_sparespercyl;
        sl->sl_interleave   = lp->d_interleave;
        sl->sl_ncylinders   = lp->d_ncylinders;
        sl->sl_acylinders   = lp->d_acylinders;
        sl->sl_ntracks      = lp->d_ntracks;
        sl->sl_nsectors     = lp->d_nsectors;

        secpercyl = sl->sl_nsectors * sl->sl_ntracks;
        for (i = 0; i < 8; i++) {
                spp = &sl->sl_part[i];
                npp = &lp->d_partitions[i];

                /*
                 * SunOS partitions must start on a cylinder boundary.
                 * Note this restriction is forced upon NetBSD/sparc
                 * labels too, since we want to keep both labels
                 * synchronised.
                 */
                if (npp->p_offset % secpercyl)
                        return (EINVAL);
                spp->sdkp_cyloffset = npp->p_offset / secpercyl;
                spp->sdkp_nsectors = npp->p_size;
        }
        sl->sl_magic = SUN_DKMAGIC;

        /* Compute the XOR check. */
        sp1 = (u_short *)sl;
        sp2 = (u_short *)(sl + 1);
        sl->sl_cksum = cksum = 0;
        while (sp1 < sp2)
                cksum ^= *sp1++;
        sl->sl_cksum = cksum;

        return (0);
}