/*      $NetBSD: disklabel.c,v 1.12 2021/05/26 04:28:15 mrg Exp $       */

/*-
* Copyright (c) 1993
*      The 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.
*
*      @(#)disklabel.c 8.1 (Berkeley) 6/11/93
*/

#include <sys/param.h>
#include <sys/disklabel.h>
#include <lib/libkern/libkern.h>
#include "stand.h"


#if defined(LIBSA_NO_DISKLABEL_MSGS)
#define nolabel (char *)1
#define corruptedlabel (char *)1
#else
static char nolabel[] = "no disk label";
static char corruptedlabel[] = "disk label corrupted";
#endif

char *
getdisklabel(const char *buf, struct disklabel *lp)
{
       const struct disklabel *dlp, *elp;
       char *msg = NULL;

       elp = (const void *)(buf + DEV_BSIZE - sizeof(*dlp));
       for (dlp = (const void *)buf; dlp <= elp;
           dlp = (const void *)((const char *)dlp + sizeof(long))) {
#if defined(LIBSA_DISKLABEL_EI)
               if (dlp->d_magic == bswap32(DISKMAGIC) &&
                   dlp->d_magic2 == bswap32(DISKMAGIC)) {
                       disklabel_swap(__UNCONST(dlp), __UNCONST(dlp));
               }
#endif
               if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
                       if (msg == NULL)
                               msg = nolabel;
               } else if (dlp->d_npartitions > MAXPARTITIONS ||
                          dkcksum(dlp) != 0) {
                       msg = corruptedlabel;
               } else {
                       (void)memcpy(lp, dlp, sizeof *lp);
                       msg = NULL;
                       break;
               }
       }
       return msg;
}