sys/lib/libsa/disklabel.c

   1 /*      $NetBSD: disklabel.c,v 1.10 2007/11/24 13:20:54 isaki Exp $     */
   2
   3 /*-
   4  * Copyright (c) 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)disklabel.c 8.1 (Berkeley) 6/11/93
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/disklabel.h>
  36 #include "stand.h"
  37
  38
  39 #if defined(LIBSA_NO_DISKLABEL_MSGS)
  40 #define nolabel (char *)1
  41 #define corruptedlabel (char *)1
  42 #else
  43 static char nolabel[] = "no disk label";
  44 static char corruptedlabel[] = "disk label corrupted";
  45 #endif
  46
  47 char *
  48 getdisklabel(const char *buf, struct disklabel *lp)
  49 {
  50         const struct disklabel *dlp, *elp;
  51         char *msg = NULL;
  52
  53         elp = (const void *)(buf + DEV_BSIZE - sizeof(*dlp));
  54         for (dlp = (const void *)buf; dlp <= elp;
  55             dlp = (const void *)((const char *)dlp + sizeof(long))) {
  56                 if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) {
  57                         if (msg == NULL)
  58                                 msg = nolabel;
  59                 } else if (dlp->d_npartitions > MAXPARTITIONS ||
  60                            dkcksum(dlp) != 0) {
  61                         msg = corruptedlabel;
  62                 } else {
  63                         (void)memcpy(lp, dlp, sizeof *lp);
  64                         msg = NULL;
  65                         break;
  66                 }
  67         }
  68         return msg;
  69 }