/*      $NetBSD: disksubr.c,v 1.58 2019/04/03 22:10:50 christos 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.
 *
 *      @(#)ufs_disksubr.c      7.16 (Berkeley) 5/4/91
 */
/*-
 * Copyright (C) 1993   Allen K. Briggs, Chris P. Caputo,
 *                      Michael L. Finch, Bradley A. Grantham, and
 *                      Lawrence A. Kesteloot
 * 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 Alice Group.
 * 4. The names of the Alice Group or any of its members may not be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE ALICE GROUP ``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 ALICE GROUP 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 1.58 2019/04/03 22:10:50 christos Exp $");

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

#include <sys/bswap.h>

#define NUM_PARTS 32

#define ROOT_PART 1
#define UFS_PART 2
#define SWAP_PART 3
#define HFS_PART 4
#define SCRATCH_PART 5

int fat_types[] = {
        MBR_PTYPE_FAT12, MBR_PTYPE_FAT16S,
        MBR_PTYPE_FAT16B, MBR_PTYPE_FAT32,
        MBR_PTYPE_FAT32L, MBR_PTYPE_FAT16L,
        -1
};

static int getFreeLabelEntry(struct disklabel *);
static int whichType(struct part_map_entry *);
static void setpartition(struct part_map_entry *, struct partition *, int);
static int getNamedType(struct part_map_entry *, int, struct disklabel *, int,
            int, int *);
static char *read_mac_label(char *, struct disklabel *, int *);
static char *read_mbr_label(char *, struct disklabel *, int *);
static const char *read_bsd_label(char *, struct disklabel *, int *);


/*
 * Find an entry in the disk label that is unused and return it
 * or -1 if no entry
 */
static int
getFreeLabelEntry(struct disklabel *lp)
{
        int i;

        for (i = 0; i < MAXPARTITIONS; i++) {
                if ((i != RAW_PART)
                    && (lp->d_partitions[i].p_fstype == FS_UNUSED))
                        return i;
        }
        return -1;
}

/*
 * figure out what the type of the given part is and return it
 */
static int
whichType(struct part_map_entry *part)
{
        struct blockzeroblock *bzb;
        char typestr[32], *s;
        int type;

        if (part->pmSig != PART_ENTRY_MAGIC || part->pmPartType[0] == '\0')
                return 0;

        strncpy(typestr, (char *)part->pmPartType, sizeof(typestr));
        typestr[sizeof(typestr) - 1] = '\0';
        for (s = typestr; *s; s++)
                if ((*s >= 'a') && (*s <= 'z'))
                        *s = (*s - 'a' + 'A');

        if (strcmp(PART_TYPE_DRIVER, typestr) == 0 ||
            strcmp(PART_TYPE_DRIVER43, typestr) == 0 ||
            strcmp(PART_TYPE_DRIVERATA, typestr) == 0 ||
            strcmp(PART_TYPE_FWB_COMPONENT, typestr) == 0 ||
            strcmp(PART_TYPE_PARTMAP, typestr) == 0)
                type = 0;
        else if (strcmp(PART_TYPE_UNIX, typestr) == 0) {
                /* unix part, swap, root, usr */
                bzb = (struct blockzeroblock *)(&part->pmBootArgs);
                if (bzb->bzbMagic != BZB_MAGIC)
                        type = 0;
                else if (bzb->bzbFlags & BZB_ROOTFS)
                        type = ROOT_PART;
                else if (bzb->bzbFlags & BZB_USRFS)
                        type = UFS_PART;
                else if (bzb->bzbType == BZB_TYPESWAP)
                        type = SWAP_PART;
                else
                        type = SCRATCH_PART;
        } else if (strcmp(PART_TYPE_MAC, typestr) == 0)
                type = HFS_PART;
        else
                type = SCRATCH_PART;    /* no known type */

        return type;
}

static void
setpartition(struct part_map_entry *part, struct partition *pp, int fstype)
{
        pp->p_size = part->pmPartBlkCnt;
        pp->p_offset = part->pmPyPartStart;
        pp->p_fstype = fstype;

        part->pmPartType[0] = '\0';
}

static int
getNamedType(struct part_map_entry *part, int num_parts, struct disklabel *lp,
    int type, int alt, int *maxslot)
{
        struct blockzeroblock *bzb;
        int i;

        for (i = 0; i < num_parts; i++) {
                if (whichType(part + i) != type)
                        continue;

                if (type == ROOT_PART) {
                        bzb = (struct blockzeroblock *)
                            (&(part + i)->pmBootArgs);
                        if (alt >= 0 && alt != bzb->bzbCluster)
                                continue;
                        setpartition(part + i, &lp->d_partitions[0], FS_BSDFFS);
                } else if (type == UFS_PART) {
                        bzb = (struct blockzeroblock *)
                            (&(part + i)->pmBootArgs);
                        if (alt >= 0 && alt != bzb->bzbCluster)
                                continue;
                        setpartition(part + i, &lp->d_partitions[6], FS_BSDFFS);
                        if (*maxslot < 6)
                                *maxslot = 6;
                } else if (type == SWAP_PART) {
                        setpartition(part + i, &lp->d_partitions[1], FS_SWAP);
                        if (*maxslot < 1)
                                *maxslot = 1;
                } else
                        printf("disksubr.c: can't do type %d\n", type);

                return 0;
        }

        return -1;
}

/*
 * MF --
 * here's what i'm gonna do:
 * read in the entire diskpartition table, it may be bigger or smaller
 * than NUM_PARTS but read that many entries.  Each entry has a magic
 * number so we'll know if an entry is crap.
 * next fill in the disklabel with info like this
 * next fill in the root, usr, and swap parts.
 * then look for anything else and fit it in.
 *      A: root
 *      B: Swap
 *      C: Whole disk
 *      G: Usr
 *
 *
 * I'm not entirely sure what netbsd386 wants in c & d
 * 386bsd wants other stuff, so i'll leave them alone
 *
 * AKB -- I added to Mike's original algorithm by searching for a bzbCluster
 *      of zero for root, first.  This allows A/UX to live on cluster 1 and
 *      NetBSD to live on cluster 0--regardless of the actual order on the
 *      disk.  This whole algorithm should probably be changed in the future.
 */

/*
 * This uses sector zero.  If this contains what looks like a valid
 * Macintosh boot sector, we attempt to fill in the disklabel structure
 * with the partition data from block #1 on.
 */
static char *
read_mac_label(char *dlbuf, struct disklabel *lp, int *match)
{
        u_int16_t *sbSigp;
        struct part_map_entry *part;
        struct partition *pp;
        char *msg;
        int i, slot, maxslot;

        maxslot = 0;
        *match = 0;
        msg = NULL;

        sbSigp = (u_int16_t *)dlbuf;
        if (*sbSigp != DRIVER_MAP_MAGIC)
                return msg;

        /* Found Macintosh partition magic number; set up disklabel */
        *match = (-1);

        /* the Macintosh partition table starts at sector #1 */
        part = (struct part_map_entry *)(dlbuf + DEV_BSIZE);

        /* Fill in standard partitions */
        lp->d_npartitions = RAW_PART + 1;
        if (getNamedType(part, NUM_PARTS, lp, ROOT_PART, 0, &maxslot))
                getNamedType(part, NUM_PARTS, lp, ROOT_PART, -1, &maxslot);
        if (getNamedType(part, NUM_PARTS, lp, UFS_PART, 0, &maxslot))
                getNamedType(part, NUM_PARTS, lp, UFS_PART, -1, &maxslot);
        getNamedType(part, NUM_PARTS, lp, SWAP_PART, -1, &maxslot);

        /* Now get as many of the rest of the partitions as we can */
        for (i = 0; i < NUM_PARTS; i++) {
                slot = getFreeLabelEntry(lp);
                if (slot < 0)
                        break;

                pp = &lp->d_partitions[slot];

                switch (whichType(part + i)) {
                case ROOT_PART:
                /*
                 * another root part will turn into a plain old
                 * UFS_PART partition, live with it.
                 */
                case UFS_PART:
                        setpartition(part + i, pp, FS_BSDFFS);
                        break;
                case SWAP_PART:
                        setpartition(part + i, pp, FS_SWAP);
                        break;
                case HFS_PART:
                        setpartition(part + i, pp, FS_HFS);
                        break;
                case SCRATCH_PART:
                        setpartition(part + i, pp, FS_OTHER);
                        break;
                default:
                        slot = 0;
                        break;
                }
                if (slot > maxslot)
                        maxslot = slot;
        }
        lp->d_npartitions = ((maxslot >= RAW_PART) ? maxslot : RAW_PART) + 1;
        return msg;
}

/*
 * Scan the disk buffer for a DOS style master boot record.
 * Return if no match; otherwise, set up an in-core disklabel .
 *
 * XXX stuff like this really should be MI
 *
 * Since FFS is endian sensitive, we pay no effort in attempting to
 * dig up *BSD/i386 disk labels that may be present on the disk.
 * Hence anything but DOS partitions is treated as unknown FS type, but
 * this should suffice to mount_msdos Zip and other removable media.
 */
static char *
read_mbr_label(char *dlbuf, struct disklabel *lp, int *match)
{
        struct mbr_partition *dp;
        struct partition *pp;
        char *msg;
        size_t mbr_lbl_off;
        int i, *ip, slot, maxslot;

        maxslot = 0;
        *match = 0;
        msg = NULL;

        if (MBR_MAGIC != bswap16(*(u_int16_t *)(dlbuf + MBR_MAGIC_OFFSET)))
                return msg;

        /* Found MBR magic number; set up disklabel */
        *match = (-1);
        mbr_lbl_off = MBR_BBSECTOR * lp->d_secsize + MBR_PART_OFFSET;
        
        dp = (struct mbr_partition *)(dlbuf + mbr_lbl_off);
        for (i = 0; i < MBR_PART_COUNT; i++, dp++) {
                if (dp->mbrp_type == 0)
                        continue;
                
                slot = getFreeLabelEntry(lp);
                maxslot = (slot > maxslot) ? maxslot : slot;
                
                pp = &lp->d_partitions[slot];
                pp->p_fstype = FS_OTHER;
                pp->p_offset = bswap32(dp->mbrp_start);
                pp->p_size = bswap32(dp->mbrp_size);
                
                for (ip = fat_types; *ip != -1; ip++) {
                        if (dp->mbrp_type == *ip) {
                                pp->p_fstype = FS_MSDOS;
                                break;
                        }
                }
        }
        lp->d_npartitions = ((maxslot >= RAW_PART) ? maxslot : RAW_PART) + 1;
        return msg;
}

/*
 * Scan the disk buffer in four byte steps for a native BSD disklabel
 * (different ports have variable-sized bootcode before the label)
 */
static const char *
read_bsd_label(char *dlbuf, struct disklabel *lp, int *match)
{
        struct disklabel *dlp;
        const char *msg;
        struct disklabel *blk_start, *blk_end;
        
        *match = 0;
        msg = NULL;

        blk_start = (struct disklabel *)dlbuf;
        blk_end = (struct disklabel *)(dlbuf + (NUM_PARTS << DEV_BSHIFT) -
            sizeof(struct disklabel));

        for (dlp = blk_start; dlp <= blk_end; 
             dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
                if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC) {
                        /* Sanity check */
                        if (dlp->d_npartitions <= MAXPARTITIONS && 
                            dkcksum(dlp) == 0) {
                                *lp = *dlp;
                                *match = (-1);
                        } else
                                msg = "Disk label corrupted";
                        break;
                }
        }
        return msg;
}

/*
 * Attempt to read a disk label from a device using the indicated strategy
 * routine.  The label must be partly set up before this: secpercyl and
 * anything required in the strategy routine (e.g., sector size) must be
 * filled in before calling us.  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 *osdep)
{
        struct buf *bp;
        const char *msg;
        int size;

        if (lp->d_secperunit == 0)
                lp->d_secperunit = 0x1fffffff;

        if (lp->d_secpercyl == 0)
                return msg = "Zero secpercyl";

        msg = NULL;

        /* 
         * Read in the first #(NUM_PARTS + 1) blocks of the disk.
         * The native Macintosh partition table starts at 
         * sector #1, but we want #0 too for the BSD label.
         */

        size = roundup((NUM_PARTS + 1) << DEV_BSHIFT, lp->d_secsize);
        bp = geteblk(size);

        bp->b_dev = dev;
        bp->b_blkno = 0;
        bp->b_resid = 0;
        bp->b_bcount = size;
        bp->b_flags |= B_READ;
        bp->b_cylinder = 1 / lp->d_secpercyl;
        (*strat)(bp);

        if (biowait(bp)) {
                msg = "I/O error reading block zero";
        } else {
                int match;

                /* Add any offsets in the table handlers */
                msg = read_mac_label(bp->b_data, lp, &match);
                if (!match && msg == NULL)
                        msg = read_mbr_label(bp->b_data, lp, &match);
                if (!match && msg == NULL)
                        msg = read_bsd_label(bp->b_data, lp, &match);
                if (!match && msg == NULL)
                        msg = "no disk label";
        }

        brelse(bp, 0);
        return (msg);
}

/*
 * Check new disk label for sensibility before setting it.
 */
int
setdisklabel(struct disklabel *olp, struct disklabel *nlp, u_long openmask,
    struct cpu_disklabel *osdep)
{
        return 0;
}

/*
 * Write disk label back to device after modification.
 *
 *  MF - 8-14-93 This function is never called.  It is here just in case
 *  we want to write dos disklabels some day. Really!
 */
int
writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp,
    struct cpu_disklabel *osdep)
{
#if 0
        struct buf *bp;
        struct disklabel *dlp;
        int labelpart;
        int error = 0;

        labelpart = DISKPART(dev);
        if (lp->d_partitions[labelpart].p_offset != 0) {
                if (lp->d_partitions[0].p_offset != 0)
                        return (EXDEV); /* not quite right */
                labelpart = 0;
        }
        bp = geteblk((int)lp->d_secsize);
        bp->b_dev = MAKEDISKDEV(major(dev), DISKUNIT(dev), labelpart);
        bp->b_blkno = LABELSECTOR;
        bp->b_bcount = lp->d_secsize;
        bp->b_flags |= B_READ;
        (*strat)(bp);
        if (error = biowait(bp))
                goto done;
        for (dlp = (struct disklabel *)bp->b_data;
            dlp <= (struct disklabel *)
            ((char *)bp->b_data + lp->d_secsize - sizeof(*dlp));
            dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
                if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
                    dkcksum(dlp) == 0) {
                        *dlp = *lp;
                        bp->b_oflags &= ~(BO_DONE);
                        bp->b_flags &= ~(B_READ);
                        bp->b_flags |= B_WRITE;
                        (*strat)(bp);
                        error = biowait(bp);
                        goto done;
                }
        }
        error = ESRCH;
done:
        brelse(bp, 0);
        return (error);
#else
        int i;

        /*
         * Clear and re-analyze the ondisk Apple Disk Partition Map,
         * then recompute the faked incore disk label. This is necessary
         * for sysinst, which may have modified the disk layout. We don't
         * (yet?) support writing real BSD disk labels, so this hack
         * instead causes the DIOCWDINFO ioctl invoked by sysinst to
         * update the in-core disk label when it is "written" to disk.
         * This code was originally developed by Bob Nestor on 9/13/99.
         */
        lp->d_npartitions = 0;
        for (i = 0; i < MAXPARTITIONS; i++) {
                lp->d_partitions[i].p_fstype = FS_UNUSED;
                lp->d_partitions[i].p_offset = 0;
                if (i != RAW_PART)
                        lp->d_partitions[i].p_size = 0;
        }
        return (readdisklabel(dev, strat, lp, osdep) ? EINVAL : 0);
#endif
}