sys/arch/atari/stand/ahdilabel/magic.c

   1 /*      $NetBSD: magic.c,v 1.2 2008/04/28 20:23:15 martin Exp $ */
   2
   3 /*
   4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Julian Coleman, Waldi Ravens and Leo Weppelman.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "privahdi.h"
  33 #include <stdlib.h>
  34
  35 /*
  36  * Check label magic numbers for AHDI partitions
  37  */
  38 int
  39 check_magic(int fd, u_int offset, int flags)
  40 {
  41         u_char  *bblk;
  42         u_int    nsec;
  43         int      rv = 1;
  44
  45         nsec = (BBMINSIZE + (DEV_BSIZE - 1)) / DEV_BSIZE;
  46         bblk = disk_read(fd, offset, nsec);
  47         if (bblk != NULL) {
  48                 u_int   *end, *p;
  49
  50                 end = (u_int *)&bblk[BBMINSIZE - sizeof(struct disklabel)];
  51                 for (p = (u_int *)bblk; p < end; ++p) {
  52                         struct disklabel *dl = (struct disklabel *)&p[1];
  53                         if (((p[0] == NBDAMAGIC && offset == 0 &&
  54                             !(flags & FORCE_AHDI)) ||
  55                             (p[0] == AHDIMAGIC && offset != 0) ||
  56                             (u_char *)dl - bblk == 7168) &&
  57                             dl->d_npartitions <= MAXPARTITIONS &&
  58                             dl->d_magic2 == DISKMAGIC &&
  59                             dl->d_magic  == DISKMAGIC &&
  60                             dkcksum(dl)  == 0) {
  61                                 rv = -3;
  62                                 break;
  63                         }
  64                 }
  65                 free(bblk);
  66         }
  67         else
  68                 rv = -1;
  69
  70         return (rv);
  71 }