diff options
author | obrien <obrien@FreeBSD.org> | 2001-07-09 10:35:18 +0000 |
---|---|---|
committer | obrien <obrien@FreeBSD.org> | 2001-07-09 10:35:18 +0000 |
commit | a72361c15b80c8dbedfab7d4281a74712fdcd14f (patch) | |
tree | ba97756f9a412a2d7d9a1fd20ab2bd1f3f3dac78 /sbin/fsck_msdosfs/boot.c | |
parent | eaa6ee03b8ac1955cc60d99d119a22318d1baa61 (diff) | |
download | FreeBSD-src-a72361c15b80c8dbedfab7d4281a74712fdcd14f.zip FreeBSD-src-a72361c15b80c8dbedfab7d4281a74712fdcd14f.tar.gz |
Add fsck_msdosfs.
Obtained from: NetBSD
Diffstat (limited to 'sbin/fsck_msdosfs/boot.c')
-rw-r--r-- | sbin/fsck_msdosfs/boot.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/sbin/fsck_msdosfs/boot.c b/sbin/fsck_msdosfs/boot.c new file mode 100644 index 0000000..5c1ae5a --- /dev/null +++ b/sbin/fsck_msdosfs/boot.c @@ -0,0 +1,268 @@ +/* + * 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 1.5 1997/10/17 11:19:23 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 filesystem 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; + } + if (memcmp(block, backup, DOSBOOTBLOCKSIZE)) { + /* Correct? XXX */ + pfatal("backup doesn't compare to primary bootblock"); + 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 neccessary, but otherwise ignoring the + * fact that it was incorrect. + */ + return 0; +} |