4029695dbf
Allow check to proceed with bad backup boot block if we're doing a readonly check. Various typos in comments. Obtained from: NetBSD
273 lines
8.6 KiB
C
273 lines
8.6 KiB
C
/*
|
|
* Copyright (C) 1995, 1997 Wolfgang Solfrank
|
|
* Copyright (c) 1995 Martin Husemann
|
|
*
|
|
* 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 Martin Husemann
|
|
* and Wolfgang Solfrank.
|
|
* 4. 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 AUTHORS ``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 AUTHORS 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>
|
|
#ifndef lint
|
|
__RCSID("$NetBSD: boot.c,v 1.9 2003/07/24 19:25:46 ws Exp $");
|
|
static const char rcsid[] =
|
|
"$FreeBSD$";
|
|
#endif /* not lint */
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <ctype.h>
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
|
|
#include "ext.h"
|
|
#include "fsutil.h"
|
|
|
|
int
|
|
readboot(dosfs, boot)
|
|
int dosfs;
|
|
struct bootblock *boot;
|
|
{
|
|
u_char block[DOSBOOTBLOCKSIZE];
|
|
u_char fsinfo[2 * DOSBOOTBLOCKSIZE];
|
|
u_char backup[DOSBOOTBLOCKSIZE];
|
|
int ret = FSOK;
|
|
|
|
if (read(dosfs, block, sizeof block) < sizeof block) {
|
|
perror("could not read boot block");
|
|
return FSFATAL;
|
|
}
|
|
|
|
if (block[510] != 0x55 || block[511] != 0xaa) {
|
|
pfatal("Invalid signature in boot block: %02x%02x", block[511], block[510]);
|
|
return FSFATAL;
|
|
}
|
|
|
|
memset(boot, 0, sizeof *boot);
|
|
boot->ValidFat = -1;
|
|
|
|
/* decode bios parameter block */
|
|
boot->BytesPerSec = block[11] + (block[12] << 8);
|
|
boot->SecPerClust = block[13];
|
|
boot->ResSectors = block[14] + (block[15] << 8);
|
|
boot->FATs = block[16];
|
|
boot->RootDirEnts = block[17] + (block[18] << 8);
|
|
boot->Sectors = block[19] + (block[20] << 8);
|
|
boot->Media = block[21];
|
|
boot->FATsmall = block[22] + (block[23] << 8);
|
|
boot->SecPerTrack = block[24] + (block[25] << 8);
|
|
boot->Heads = block[26] + (block[27] << 8);
|
|
boot->HiddenSecs = block[28] + (block[29] << 8) + (block[30] << 16) + (block[31] << 24);
|
|
boot->HugeSectors = block[32] + (block[33] << 8) + (block[34] << 16) + (block[35] << 24);
|
|
|
|
boot->FATsecs = boot->FATsmall;
|
|
|
|
if (!boot->RootDirEnts)
|
|
boot->flags |= FAT32;
|
|
if (boot->flags & FAT32) {
|
|
boot->FATsecs = block[36] + (block[37] << 8)
|
|
+ (block[38] << 16) + (block[39] << 24);
|
|
if (block[40] & 0x80)
|
|
boot->ValidFat = block[40] & 0x0f;
|
|
|
|
/* check version number: */
|
|
if (block[42] || block[43]) {
|
|
/* Correct? XXX */
|
|
pfatal("Unknown file system version: %x.%x",
|
|
block[43], block[42]);
|
|
return FSFATAL;
|
|
}
|
|
boot->RootCl = block[44] + (block[45] << 8)
|
|
+ (block[46] << 16) + (block[47] << 24);
|
|
boot->FSInfo = block[48] + (block[49] << 8);
|
|
boot->Backup = block[50] + (block[51] << 8);
|
|
|
|
if (lseek(dosfs, boot->FSInfo * boot->BytesPerSec, SEEK_SET)
|
|
!= boot->FSInfo * boot->BytesPerSec
|
|
|| read(dosfs, fsinfo, sizeof fsinfo)
|
|
!= sizeof fsinfo) {
|
|
perror("could not read fsinfo block");
|
|
return FSFATAL;
|
|
}
|
|
if (memcmp(fsinfo, "RRaA", 4)
|
|
|| memcmp(fsinfo + 0x1e4, "rrAa", 4)
|
|
|| fsinfo[0x1fc]
|
|
|| fsinfo[0x1fd]
|
|
|| fsinfo[0x1fe] != 0x55
|
|
|| fsinfo[0x1ff] != 0xaa
|
|
|| fsinfo[0x3fc]
|
|
|| fsinfo[0x3fd]
|
|
|| fsinfo[0x3fe] != 0x55
|
|
|| fsinfo[0x3ff] != 0xaa) {
|
|
pwarn("Invalid signature in fsinfo block");
|
|
if (ask(0, "fix")) {
|
|
memcpy(fsinfo, "RRaA", 4);
|
|
memcpy(fsinfo + 0x1e4, "rrAa", 4);
|
|
fsinfo[0x1fc] = fsinfo[0x1fd] = 0;
|
|
fsinfo[0x1fe] = 0x55;
|
|
fsinfo[0x1ff] = 0xaa;
|
|
fsinfo[0x3fc] = fsinfo[0x3fd] = 0;
|
|
fsinfo[0x3fe] = 0x55;
|
|
fsinfo[0x3ff] = 0xaa;
|
|
if (lseek(dosfs, boot->FSInfo * boot->BytesPerSec, SEEK_SET)
|
|
!= boot->FSInfo * boot->BytesPerSec
|
|
|| write(dosfs, fsinfo, sizeof fsinfo)
|
|
!= sizeof fsinfo) {
|
|
perror("Unable to write FSInfo");
|
|
return FSFATAL;
|
|
}
|
|
ret = FSBOOTMOD;
|
|
} else
|
|
boot->FSInfo = 0;
|
|
}
|
|
if (boot->FSInfo) {
|
|
boot->FSFree = fsinfo[0x1e8] + (fsinfo[0x1e9] << 8)
|
|
+ (fsinfo[0x1ea] << 16)
|
|
+ (fsinfo[0x1eb] << 24);
|
|
boot->FSNext = fsinfo[0x1ec] + (fsinfo[0x1ed] << 8)
|
|
+ (fsinfo[0x1ee] << 16)
|
|
+ (fsinfo[0x1ef] << 24);
|
|
}
|
|
|
|
if (lseek(dosfs, boot->Backup * boot->BytesPerSec, SEEK_SET)
|
|
!= boot->Backup * boot->BytesPerSec
|
|
|| read(dosfs, backup, sizeof backup) != sizeof backup) {
|
|
perror("could not read backup bootblock");
|
|
return FSFATAL;
|
|
}
|
|
backup[65] = block[65]; /* XXX */
|
|
if (memcmp(block + 11, backup + 11, 79)) {
|
|
/* Correct? XXX */
|
|
pfatal("backup doesn't compare to primary bootblock");
|
|
if (alwaysno)
|
|
pfatal("\n");
|
|
else
|
|
return FSFATAL;
|
|
}
|
|
/* Check backup FSInfo? XXX */
|
|
}
|
|
|
|
boot->ClusterOffset = (boot->RootDirEnts * 32 + boot->BytesPerSec - 1)
|
|
/ boot->BytesPerSec
|
|
+ boot->ResSectors
|
|
+ boot->FATs * boot->FATsecs
|
|
- CLUST_FIRST * boot->SecPerClust;
|
|
|
|
if (boot->BytesPerSec % DOSBOOTBLOCKSIZE != 0) {
|
|
pfatal("Invalid sector size: %u", boot->BytesPerSec);
|
|
return FSFATAL;
|
|
}
|
|
if (boot->SecPerClust == 0) {
|
|
pfatal("Invalid cluster size: %u", boot->SecPerClust);
|
|
return FSFATAL;
|
|
}
|
|
if (boot->Sectors) {
|
|
boot->HugeSectors = 0;
|
|
boot->NumSectors = boot->Sectors;
|
|
} else
|
|
boot->NumSectors = boot->HugeSectors;
|
|
boot->NumClusters = (boot->NumSectors - boot->ClusterOffset) / boot->SecPerClust;
|
|
|
|
if (boot->flags&FAT32)
|
|
boot->ClustMask = CLUST32_MASK;
|
|
else if (boot->NumClusters < (CLUST_RSRVD&CLUST12_MASK))
|
|
boot->ClustMask = CLUST12_MASK;
|
|
else if (boot->NumClusters < (CLUST_RSRVD&CLUST16_MASK))
|
|
boot->ClustMask = CLUST16_MASK;
|
|
else {
|
|
pfatal("Filesystem too big (%u clusters) for non-FAT32 partition",
|
|
boot->NumClusters);
|
|
return FSFATAL;
|
|
}
|
|
|
|
switch (boot->ClustMask) {
|
|
case CLUST32_MASK:
|
|
boot->NumFatEntries = (boot->FATsecs * boot->BytesPerSec) / 4;
|
|
break;
|
|
case CLUST16_MASK:
|
|
boot->NumFatEntries = (boot->FATsecs * boot->BytesPerSec) / 2;
|
|
break;
|
|
default:
|
|
boot->NumFatEntries = (boot->FATsecs * boot->BytesPerSec * 2) / 3;
|
|
break;
|
|
}
|
|
|
|
if (boot->NumFatEntries < boot->NumClusters) {
|
|
pfatal("FAT size too small, %u entries won't fit into %u sectors\n",
|
|
boot->NumClusters, boot->FATsecs);
|
|
return FSFATAL;
|
|
}
|
|
boot->ClusterSize = boot->BytesPerSec * boot->SecPerClust;
|
|
|
|
boot->NumFiles = 1;
|
|
boot->NumFree = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
int
|
|
writefsinfo(dosfs, boot)
|
|
int dosfs;
|
|
struct bootblock *boot;
|
|
{
|
|
u_char fsinfo[2 * DOSBOOTBLOCKSIZE];
|
|
|
|
if (lseek(dosfs, boot->FSInfo * boot->BytesPerSec, SEEK_SET)
|
|
!= boot->FSInfo * boot->BytesPerSec
|
|
|| read(dosfs, fsinfo, sizeof fsinfo) != sizeof fsinfo) {
|
|
perror("could not read fsinfo block");
|
|
return FSFATAL;
|
|
}
|
|
fsinfo[0x1e8] = (u_char)boot->FSFree;
|
|
fsinfo[0x1e9] = (u_char)(boot->FSFree >> 8);
|
|
fsinfo[0x1ea] = (u_char)(boot->FSFree >> 16);
|
|
fsinfo[0x1eb] = (u_char)(boot->FSFree >> 24);
|
|
fsinfo[0x1ec] = (u_char)boot->FSNext;
|
|
fsinfo[0x1ed] = (u_char)(boot->FSNext >> 8);
|
|
fsinfo[0x1ee] = (u_char)(boot->FSNext >> 16);
|
|
fsinfo[0x1ef] = (u_char)(boot->FSNext >> 24);
|
|
if (lseek(dosfs, boot->FSInfo * boot->BytesPerSec, SEEK_SET)
|
|
!= boot->FSInfo * boot->BytesPerSec
|
|
|| write(dosfs, fsinfo, sizeof fsinfo)
|
|
!= sizeof fsinfo) {
|
|
perror("Unable to write FSInfo");
|
|
return FSFATAL;
|
|
}
|
|
/*
|
|
* Technically, we should return FSBOOTMOD here.
|
|
*
|
|
* However, since Win95 OSR2 (the first M$ OS that has
|
|
* support for FAT32) doesn't maintain the FSINFO block
|
|
* correctly, it has to be fixed pretty often.
|
|
*
|
|
* Therefor, we handle the FSINFO block only informally,
|
|
* fixing it if necessary, but otherwise ignoring the
|
|
* fact that it was incorrect.
|
|
*/
|
|
return 0;
|
|
}
|