pmt: revert 7f8090b
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@@ -1,271 +0,0 @@
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/*
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libparted
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Copyright (C) 1998-2000, 2002, 2004, 2007, 2009-2014, 2019-2023 Free
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Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <config.h>
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#include "fat.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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/* Reads in the boot sector (superblock), and does a minimum of sanity
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* checking. The goals are:
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* - to detect fat file systems, even if they are damaged [i.e. not
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* return an error / throw an exception]
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* - to fail detection if there's not enough information for
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* fat_boot_sector_probe_type() to work (or possibly crash on a divide-by-zero)
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*/
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int
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fat_boot_sector_read (FatBootSector** bsp, const PedGeometry *geom)
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{
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PED_ASSERT (bsp != NULL);
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PED_ASSERT (geom != NULL);
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if (!ped_geometry_read_alloc (geom, (void **)bsp, 0, 1))
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return 0;
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FatBootSector *bs = *bsp;
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if (PED_LE16_TO_CPU (bs->boot_sign) != 0xAA55) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("File system has an invalid signature for a FAT "
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"file system."));
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return 0;
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}
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if (!bs->sector_size
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|| PED_LE16_TO_CPU (bs->sector_size) % PED_SECTOR_SIZE_DEFAULT) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("File system has an invalid sector size for a FAT "
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"file system."));
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return 0;
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}
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if (!bs->cluster_size) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("File system has an invalid cluster size for a FAT "
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"file system."));
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return 0;
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}
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if (!bs->reserved) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("File system has an invalid number of reserved "
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"sectors for a FAT file system."));
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return 0;
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}
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if (bs->fats < 1 || bs->fats > 4) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("File system has an invalid number of FATs."));
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return 0;
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}
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return 1;
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}
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/*
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Don't trust the FAT12, FAT16 or FAT32 label string.
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*/
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FatType _GL_ATTRIBUTE_PURE
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fat_boot_sector_probe_type (const FatBootSector* bs, const PedGeometry* geom)
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{
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PedSector logical_sector_size;
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PedSector first_cluster_sector;
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FatCluster cluster_count;
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if (!PED_LE16_TO_CPU (bs->dir_entries))
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return FAT_TYPE_FAT32;
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logical_sector_size = PED_LE16_TO_CPU (bs->sector_size) / 512;
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first_cluster_sector
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= PED_LE16_TO_CPU (bs->reserved) * logical_sector_size
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+ 2 * PED_LE16_TO_CPU (bs->fat_length) * logical_sector_size
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+ PED_LE16_TO_CPU (bs->dir_entries)
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/ (512 / sizeof (FatDirEntry));
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cluster_count = (geom->length - first_cluster_sector)
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/ bs->cluster_size / logical_sector_size;
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if (cluster_count > MAX_FAT12_CLUSTERS)
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return FAT_TYPE_FAT16;
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else
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return FAT_TYPE_FAT12;
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}
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static int
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_fat_table_entry_size (FatType fat_type)
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{
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switch (fat_type) {
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case FAT_TYPE_FAT12:
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return 2; /* FIXME: how? */
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case FAT_TYPE_FAT16:
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return 2;
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case FAT_TYPE_FAT32:
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return 4;
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}
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return 0;
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}
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/* Analyses the boot sector, and sticks appropriate numbers in
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fs->type_specific.
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Note: you need to subtract (2 * cluster_sectors) off cluster offset,
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because the first cluster is number 2. (0 and 1 are not real clusters,
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and referencing them is a bug)
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*/
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int
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fat_boot_sector_analyse (FatBootSector* bs, PedFileSystem* fs)
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{
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FatSpecific* fs_info = FAT_SPECIFIC (fs);
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int fat_entry_size;
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PED_ASSERT (bs != NULL);
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fs_info->logical_sector_size = PED_LE16_TO_CPU (bs->sector_size) / 512;
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fs_info->sectors_per_track = PED_LE16_TO_CPU (bs->secs_track);
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fs_info->heads = PED_LE16_TO_CPU (bs->heads);
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if (fs_info->sectors_per_track < 1 || fs_info->sectors_per_track > 63
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|| fs_info->heads < 1 || fs_info->heads > 255) {
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PedCHSGeometry* bios_geom = &fs->geom->dev->bios_geom;
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int cyl_count = 0;
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if (fs_info->heads > 0 && fs_info->sectors_per_track > 0)
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cyl_count = fs->geom->dev->length / fs_info->heads
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/ fs_info->sectors_per_track;
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switch (ped_exception_throw (
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PED_EXCEPTION_ERROR,
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PED_EXCEPTION_IGNORE_CANCEL,
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_("The file system's CHS geometry is (%d, %d, %d), "
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"which is invalid. The partition table's CHS "
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"geometry is (%d, %d, %d)."),
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cyl_count, fs_info->heads, fs_info->sectors_per_track,
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bios_geom->cylinders, bios_geom->heads,
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bios_geom->sectors)) {
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case PED_EXCEPTION_CANCEL:
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return 0;
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case PED_EXCEPTION_IGNORE:
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break;
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default:
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break;
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}
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}
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if (bs->sectors)
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fs_info->sector_count = PED_LE16_TO_CPU (bs->sectors)
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* fs_info->logical_sector_size;
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else
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fs_info->sector_count = PED_LE32_TO_CPU (bs->sector_count)
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* fs_info->logical_sector_size;
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fs_info->fat_table_count = bs->fats;
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fs_info->root_dir_entry_count = PED_LE16_TO_CPU (bs->dir_entries);
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fs_info->fat_offset = PED_LE16_TO_CPU (bs->reserved)
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* fs_info->logical_sector_size;
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fs_info->cluster_sectors = bs->cluster_size
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* fs_info->logical_sector_size;
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fs_info->cluster_size = fs_info->cluster_sectors * 512;
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if (fs_info->logical_sector_size == 0) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("FAT boot sector says logical sector size is 0. "
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"This is weird. "));
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return 0;
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}
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if (fs_info->fat_table_count == 0) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("FAT boot sector says there are no FAT tables. This "
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"is weird. "));
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return 0;
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}
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if (fs_info->cluster_sectors == 0) {
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ped_exception_throw (PED_EXCEPTION_ERROR, PED_EXCEPTION_CANCEL,
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_("FAT boot sector says clusters are 0 sectors. This "
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"is weird. "));
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return 0;
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}
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fs_info->fat_type = fat_boot_sector_probe_type (bs, fs->geom);
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if (fs_info->fat_type == FAT_TYPE_FAT12) {
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ped_exception_throw (
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PED_EXCEPTION_NO_FEATURE,
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PED_EXCEPTION_CANCEL,
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_("File system is FAT12, which is unsupported."));
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return 0;
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}
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if (fs_info->fat_type == FAT_TYPE_FAT16) {
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fs_info->fat_sectors = PED_LE16_TO_CPU (bs->fat_length)
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* fs_info->logical_sector_size;
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fs_info->serial_number
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= PED_LE32_TO_CPU (bs->u.fat16.serial_number);
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fs_info->root_cluster = 0;
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fs_info->root_dir_offset
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= fs_info->fat_offset
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+ fs_info->fat_sectors * fs_info->fat_table_count;
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fs_info->root_dir_sector_count
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= fs_info->root_dir_entry_count * sizeof (FatDirEntry)
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/ (512 * fs_info->logical_sector_size);
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fs_info->cluster_offset
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= fs_info->root_dir_offset
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+ fs_info->root_dir_sector_count;
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}
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if (fs_info->fat_type == FAT_TYPE_FAT32) {
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fs_info->fat_sectors = PED_LE32_TO_CPU (bs->u.fat32.fat_length)
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* fs_info->logical_sector_size;
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fs_info->serial_number
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= PED_LE32_TO_CPU (bs->u.fat32.serial_number);
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fs_info->info_sector_offset
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= PED_LE16_TO_CPU (fs_info->boot_sector->u.fat32.info_sector)
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* fs_info->logical_sector_size;
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fs_info->boot_sector_backup_offset
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= PED_LE16_TO_CPU (fs_info->boot_sector->u.fat32.backup_sector)
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* fs_info->logical_sector_size;
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fs_info->root_cluster
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= PED_LE32_TO_CPU (bs->u.fat32.root_dir_cluster);
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fs_info->root_dir_offset = 0;
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fs_info->root_dir_sector_count = 0;
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fs_info->cluster_offset
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= fs_info->fat_offset
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+ fs_info->fat_sectors * fs_info->fat_table_count;
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}
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fs_info->cluster_count
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= (fs_info->sector_count - fs_info->cluster_offset)
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/ fs_info->cluster_sectors;
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fat_entry_size = _fat_table_entry_size (fs_info->fat_type);
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if (fs_info->cluster_count + 2
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> fs_info->fat_sectors * 512 / fat_entry_size)
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fs_info->cluster_count
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= fs_info->fat_sectors * 512 / fat_entry_size - 2;
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fs_info->dir_entries_per_cluster
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= fs_info->cluster_size / sizeof (FatDirEntry);
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return 1;
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}
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