/*      $NetBSD: bsdlabel.c,v 1.5 2025/11/19 09:43:27 nia Exp $ */

/*
 * Copyright (c) 1995 Waldi Ravens.
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "libtos.h"
#include "diskio.h"
#include "ahdilbl.h"
#include "disklbl.h"

static int      dkcksum    PROTO((struct disklabel *));

int
bsd_getlabel(disk_t *dd, struct disklabel *dlp, u_int offset)
{
        u_char          *bblk;
        u_int           nsec;
        int             rv;

        nsec = (BBMINSIZE + (dd->bsize - 1)) / dd->bsize;
        bblk = disk_read(dd, offset, nsec);
        if (bblk) {
                u_int   *end, *p;
                
                end = (u_int *)&bblk[BBMINSIZE - sizeof(struct disklabel)];
                rv  = 1;
                for (p = (u_int *)bblk; p < end; ++p) {
                        struct disklabel *dl = (struct disklabel *)&p[1];
                        if (  (  (p[0] == NBDAMAGIC && offset == 0)
                              || (p[0] == AHDIMAGIC && offset != 0)
                              || (u_char *)dl - bblk == 7168
                              )
                           && dl->d_npartitions <= MAXPARTITIONS
                           && dl->d_magic2 == DISKMAGIC
                           && dl->d_magic  == DISKMAGIC
                           && dkcksum(dl)  == 0
                           )    {
                                memcpy(dlp, dl, sizeof(*dlp));
                                rv = 0;
                                break;
                        }
                }
                free(bblk);
        }
        else rv = -1;

        return(rv);
}

static int
dkcksum(struct disklabel *dl)
{
        u_short *start, *end, sum = 0;

        start = (u_short *)dl;
        end   = (u_short *)&dl->d_partitions[dl->d_npartitions];
        while (start < end)
                sum ^= *start++;
        return(sum);
}