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Diffstat (limited to 'extras/volume_id/lib/fat.c')
-rw-r--r--extras/volume_id/lib/fat.c509
1 files changed, 0 insertions, 509 deletions
diff --git a/extras/volume_id/lib/fat.c b/extras/volume_id/lib/fat.c
deleted file mode 100644
index c0cfed82c0..0000000000
--- a/extras/volume_id/lib/fat.c
+++ /dev/null
@@ -1,509 +0,0 @@
-/*
- * volume_id - reads filesystem label and uuid
- *
- * Copyright (C) 2004-2007 Kay Sievers <kay.sievers@vrfy.org>
- * Copyright (C) 2007 Ryan Lortie <desrt@desrt.ca>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE 1
-#endif
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <errno.h>
-#include <ctype.h>
-
-#include "libvolume_id.h"
-#include "libvolume_id-private.h"
-
-#define FAT12_MAX 0xff5
-#define FAT16_MAX 0xfff5
-#define FAT_ATTR_VOLUME_ID 0x08
-#define FAT_ATTR_DIR 0x10
-#define FAT_ATTR_LONG_NAME 0x0f
-#define FAT_ATTR_MASK 0x3f
-#define FAT_ENTRY_FREE 0xe5
-
-#define VFAT_LFN_SEQ_MASK 0x3f
-#define VFAT_LFN_SEQ_LAST 0x40
-#define VFAT_LFN_SEQ_MAX 20
-#define VFAT_LFN_CHARS_PER_ENTRY (5 + 6 + 2)
-#define VFAT_LOWERCASE_NAME 0x10
-#define VFAT_LOWERCASE_EXT 0x08
-
-struct vfat_super_block {
- uint8_t boot_jump[3];
- uint8_t sysid[8];
- uint16_t sector_size;
- uint8_t sectors_per_cluster;
- uint16_t reserved;
- uint8_t fats;
- uint16_t dir_entries;
- uint16_t sectors;
- uint8_t media;
- uint16_t fat_length;
- uint16_t secs_track;
- uint16_t heads;
- uint32_t hidden;
- uint32_t total_sect;
- union {
- struct fat_super_block {
- uint8_t unknown[3];
- uint8_t serno[4];
- uint8_t label[11];
- uint8_t magic[8];
- uint8_t dummy2[192];
- uint8_t pmagic[2];
- } PACKED fat;
- struct fat32_super_block {
- uint32_t fat32_length;
- uint16_t flags;
- uint8_t version[2];
- uint32_t root_cluster;
- uint16_t fsinfo_sector;
- uint16_t backup_boot;
- uint16_t reserved2[6];
- uint8_t unknown[3];
- uint8_t serno[4];
- uint8_t label[11];
- uint8_t magic[8];
- uint8_t dummy2[164];
- uint8_t pmagic[2];
- } PACKED fat32;
- } PACKED type;
-} PACKED;
-
-struct fat32_fsinfo {
- uint8_t signature1[4];
- uint32_t reserved1[120];
- uint8_t signature2[4];
- uint32_t free_clusters;
- uint32_t next_cluster;
- uint32_t reserved2[4];
-} PACKED;
-
-struct vfat_dir_entry {
- uint8_t name[11];
- uint8_t attr;
- uint8_t lowercase;
- uint8_t fine_time_creat;
- uint16_t time_creat;
- uint16_t date_creat;
- uint16_t date_acc;
- uint16_t cluster_high;
- uint16_t time_write;
- uint16_t date_write;
- uint16_t cluster_low;
- uint32_t size;
-} PACKED;
-
-
-struct vfat_lfn_entry {
- uint8_t seq;
- uint16_t name0[5];
- uint8_t attr;
- uint8_t reserved;
- uint8_t cksum;
- uint16_t name1[6];
- uint16_t cluster;
- uint16_t name2[2];
-} PACKED;
-
-static uint8_t fat_lfn_checksum(const uint8_t name[11])
-{
- uint8_t cksum = 0;
- int i;
-
- /* http://en.wikipedia.org/wiki/File_Allocation_Table */
- for (i = 0; i < 11; i++)
- cksum = ((cksum & 1) ? 0x80 : 0) + (cksum >> 1) + name[i];
-
- return cksum;
-}
-
-static size_t fat_read_lfn(uint8_t *filename, size_t fnsize,
- struct vfat_dir_entry *dir,
- struct vfat_dir_entry *entry)
-{
- uint8_t buffer[VFAT_LFN_SEQ_MAX * VFAT_LFN_CHARS_PER_ENTRY * 2];
- uint8_t expected_seq = 1;
- uint8_t cksum;
- size_t len = 0;
- size_t fnlen = 0;
-
- cksum = fat_lfn_checksum(entry->name);
-
- while (--entry >= dir) {
- struct vfat_lfn_entry *lfn = (struct vfat_lfn_entry *) entry;
-
- if (expected_seq > VFAT_LFN_SEQ_MAX)
- break;
-
- if ((lfn->attr & FAT_ATTR_MASK) != FAT_ATTR_LONG_NAME)
- break;
-
- if (lfn->cksum != cksum)
- break;
-
- if ((lfn->seq & VFAT_LFN_SEQ_MASK) != expected_seq++)
- break;
-
- if (lfn->cluster != 0)
- break;
-
- /* extra paranoia -- should never happen */
- if (len + sizeof(lfn->name0) + sizeof(lfn->name1) +
- sizeof(lfn->name2) > sizeof(buffer))
- break;
-
- memcpy (&buffer[len], lfn->name0, sizeof(lfn->name0));
- len += sizeof(lfn->name0);
- memcpy (&buffer[len], lfn->name1, sizeof(lfn->name1));
- len += sizeof(lfn->name1);
- memcpy (&buffer[len], lfn->name2, sizeof(lfn->name2));
- len += sizeof(lfn->name2);
-
- if (lfn->seq & VFAT_LFN_SEQ_LAST) {
- fnlen = volume_id_set_unicode16(filename, fnsize, buffer, LE, len);
- break;
- }
- }
-
- return fnlen;
-}
-
-static size_t fat_read_filename(uint8_t *filename, size_t fnsize,
- struct vfat_dir_entry *dir, struct vfat_dir_entry *entry)
-{
- size_t len;
- int i;
-
- /* check if maybe we have LFN entries */
- len = fat_read_lfn(filename, fnsize, dir, entry);
- if (len > 0)
- goto out;
-
- /* else, read the normal 8.3 name */
- for (i = 0; i < 11; i++) {
- if (entry->lowercase & ((i < 8) ? VFAT_LOWERCASE_NAME : VFAT_LOWERCASE_EXT))
- filename[i] = tolower(entry->name[i]);
- else
- filename[i] = entry->name[i];
- }
- len = 11;
-
-out:
- filename[len] = '\0';
- return len;
-}
-
-/* fills filename, returns string length */
-static size_t get_fat_attr_volume_id(uint8_t *filename, size_t fnsize,
- struct vfat_dir_entry *dir, unsigned int count)
-{
- unsigned int i;
-
- for (i = 0; i < count; i++) {
- /* end marker */
- if (dir[i].name[0] == 0x00) {
- dbg("end of dir\n");
- break;
- }
-
- /* empty entry */
- if (dir[i].name[0] == FAT_ENTRY_FREE)
- continue;
-
- /* long name */
- if ((dir[i].attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME)
- continue;
-
- if ((dir[i].attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) == FAT_ATTR_VOLUME_ID) {
- /* labels do not have file data */
- if (dir[i].cluster_high != 0 || dir[i].cluster_low != 0)
- continue;
-
- dbg("found ATTR_VOLUME_ID id in root dir\n");
- return fat_read_filename(filename, fnsize, dir, &dir[i]);
- }
-
- dbg("skip dir entry\n");
- }
-
- return 0;
-}
-
-int volume_id_probe_vfat(struct volume_id *id, uint64_t off, uint64_t size)
-{
- uint8_t filename[255 * 3];
- struct vfat_super_block *vs;
- struct vfat_dir_entry *dir;
- struct fat32_fsinfo *fsinfo;
- uint16_t sector_size;
- uint16_t dir_entries;
- uint32_t sect_count;
- uint16_t reserved;
- uint32_t fat_size;
- uint32_t root_cluster;
- uint32_t dir_size;
- uint32_t cluster_count;
- uint16_t fat_length;
- uint32_t fat32_length;
- uint64_t root_start;
- uint32_t start_data_sect;
- uint16_t root_dir_entries;
- uint16_t fsinfo_sect;
- uint8_t *buf;
- uint32_t buf_size;
- uint32_t next;
- int maxloop;
- size_t fnlen;
-
- info("probing at offset 0x%" PRIx64 "\n", off);
-
- buf = volume_id_get_buffer(id, off, 0x400);
- if (buf == NULL)
- return -1;
-
- vs = (struct vfat_super_block *) buf;
- if (memcmp(vs->sysid, "NTFS", 4) == 0)
- return -1;
-
- /* believe only that's fat, don't trust the version */
- if (memcmp(vs->type.fat32.magic, "MSWIN", 5) == 0)
- goto magic;
-
- if (memcmp(vs->type.fat32.magic, "FAT32 ", 8) == 0)
- goto magic;
-
- if (memcmp(vs->type.fat.magic, "FAT16 ", 8) == 0)
- goto magic;
-
- if (memcmp(vs->type.fat.magic, "MSDOS", 5) == 0)
- goto magic;
-
- if (memcmp(vs->type.fat.magic, "FAT12 ", 8) == 0)
- goto magic;
-
- /* check signature */
- if (buf[510] != 0x55 || buf[511] != 0xaa)
- return -1;
-
- /* some old floppies don't have a magic, expect the boot jump address to match */
- if ((vs->boot_jump[0] != 0xeb || vs->boot_jump[2] != 0x90) &&
- vs->boot_jump[0] != 0xe9)
- return -1;
-
-magic:
- info("magic found\n");
- /* reserverd sector count */
- if (!vs->reserved)
- return -1;
-
- /* fat count */
- if (!vs->fats)
- return -1;
-
- /* media check */
- if (vs->media < 0xf8 && vs->media != 0xf0)
- return -1;
-
- /* cluster size check */
- if (vs->sectors_per_cluster == 0 ||
- (vs->sectors_per_cluster & (vs->sectors_per_cluster-1)))
- return -1;
-
- /* sector size check */
- sector_size = le16_to_cpu(vs->sector_size);
- if (sector_size == 0 || ((sector_size & (sector_size-1)) != 0))
- return -1;
-
- info("checks passed\n");
- dbg("sector_size 0x%x\n", sector_size);
- dbg("sectors_per_cluster 0x%x\n", vs->sectors_per_cluster);
-
- dir_entries = le16_to_cpu(vs->dir_entries);
- reserved = le16_to_cpu(vs->reserved);
- dbg("reserved 0x%x\n", reserved);
-
- sect_count = le16_to_cpu(vs->sectors);
- if (sect_count == 0)
- sect_count = le32_to_cpu(vs->total_sect);
- dbg("sect_count 0x%x\n", sect_count);
-
- fat_length = le16_to_cpu(vs->fat_length);
- info("fat_length 0x%x\n", fat_length);
- fat32_length = le32_to_cpu(vs->type.fat32.fat32_length);
- info("fat32_length 0x%x\n", fat32_length);
-
- if (fat_length)
- fat_size = fat_length * vs->fats;
- else if (fat32_length)
- fat_size = fat32_length * vs->fats;
- else
- return -1;
- info("fat_size 0x%x\n", fat_size);
-
- dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
- (sector_size-1)) / sector_size;
- info("dir_size 0x%x\n", dir_size);
-
- cluster_count = sect_count - (reserved + fat_size + dir_size);
- cluster_count /= vs->sectors_per_cluster;
- info("cluster_count 0x%x\n", cluster_count);
-
- /* must be FAT32 */
- if (!fat_length && fat32_length)
- goto fat32;
-
- /* cluster_count tells us the format */
- if (cluster_count < FAT12_MAX)
- strcpy(id->type_version, "FAT12");
- else if (cluster_count < FAT16_MAX)
- strcpy(id->type_version, "FAT16");
- else
- goto fat32;
-
- /* the label may be an attribute in the root directory */
- root_start = (reserved + fat_size) * sector_size;
- dbg("root dir start 0x%" PRIx64 "\n", root_start);
- root_dir_entries = le16_to_cpu(vs->dir_entries);
- dbg("expected entries 0x%x\n", root_dir_entries);
-
- buf_size = root_dir_entries * sizeof(struct vfat_dir_entry);
- buf = volume_id_get_buffer(id, off + root_start, buf_size);
- if (buf == NULL)
- goto found;
-
- dir = (struct vfat_dir_entry*) buf;
-
- fnlen = get_fat_attr_volume_id(filename, sizeof(filename), dir, root_dir_entries);
-
- vs = (struct vfat_super_block *) volume_id_get_buffer(id, off, 0x200);
- if (vs == NULL)
- return -1;
-
- if (fnlen > 0 && memcmp(filename, "NO NAME ", 11) != 0) {
- volume_id_set_label_raw(id, filename, fnlen);
- volume_id_set_label_string(id, filename, fnlen);
- } else if (memcmp(vs->type.fat.label, "NO NAME ", 11) != 0) {
- volume_id_set_label_raw(id, vs->type.fat.label, 11);
- volume_id_set_label_string(id, vs->type.fat.label, 11);
- }
- volume_id_set_uuid(id, vs->type.fat.serno, 0, UUID_DOS);
- goto found;
-
-fat32:
- info("looking for FAT32\n");
- /*
- * FAT32 should have a valid signature in the fsinfo block,
- * but also allow all bytes set to '\0', because some volumes
- * do not set the signature at all.
- */
- fsinfo_sect = le16_to_cpu(vs->type.fat32.fsinfo_sector);
- buf = volume_id_get_buffer(id, off + (fsinfo_sect * sector_size), 0x200);
- if (buf == NULL)
- return -1;
- fsinfo = (struct fat32_fsinfo *) buf;
- info("signature1: 0x%02x%02x%02x%02x\n",
- fsinfo->signature1[0], fsinfo->signature1[1],
- fsinfo->signature1[2], fsinfo->signature1[3]);
- info("signature2: 0x%02x%02x%02x%02x\n",
- fsinfo->signature2[0], fsinfo->signature2[1],
- fsinfo->signature2[2], fsinfo->signature2[3]);
- if (memcmp(fsinfo->signature1, "\x52\x52\x61\x41", 4) != 0 &&
- memcmp(fsinfo->signature1, "\x00\x00\x00\x00", 4) != 0)
- return -1;
- if (memcmp(fsinfo->signature2, "\x72\x72\x41\x61", 4) != 0 &&
- memcmp(fsinfo->signature2, "\x00\x00\x00\x00", 4) != 0)
- return -1 ;
- info("FAT32 signatures ok\n");
-
- vs = (struct vfat_super_block *) volume_id_get_buffer(id, off, 0x200);
- if (vs == NULL)
- return -1;
-
- strcpy(id->type_version, "FAT32");
-
- /* FAT32 root dir is a cluster chain like any other directory */
- buf_size = vs->sectors_per_cluster * sector_size;
- root_cluster = le32_to_cpu(vs->type.fat32.root_cluster);
- dbg("root dir cluster %u\n", root_cluster);
- start_data_sect = reserved + fat_size;
-
- next = root_cluster;
- maxloop = 100;
- while (--maxloop) {
- uint32_t next_sect_off;
- uint64_t next_off;
- uint64_t fat_entry_off;
- int count;
-
- dbg("next cluster %u\n", next);
- next_sect_off = (next - 2) * vs->sectors_per_cluster;
- next_off = (start_data_sect + next_sect_off) * sector_size;
- dbg("cluster offset 0x%" PRIx64 "\n", next_off);
-
- /* get cluster */
- buf = volume_id_get_buffer(id, off + next_off, buf_size);
- if (buf == NULL)
- goto found;
-
- dir = (struct vfat_dir_entry*) buf;
- count = buf_size / sizeof(struct vfat_dir_entry);
- dbg("expected entries 0x%x\n", count);
-
- fnlen = get_fat_attr_volume_id(filename, sizeof(filename), dir, count);
- if (fnlen > 0)
- break;
-
- /* get FAT entry */
- fat_entry_off = (reserved * sector_size) + (next * sizeof(uint32_t));
- buf = volume_id_get_buffer(id, off + fat_entry_off, buf_size);
- if (buf == NULL)
- goto found;
-
- /* set next cluster */
- next = le32_to_cpu(*((uint32_t *) buf)) & 0x0fffffff;
- if (next < 2 || next >= 0x0ffffff0)
- break;
- }
- if (maxloop == 0)
- dbg("reached maximum follow count of root cluster chain, give up\n");
-
- vs = (struct vfat_super_block *) volume_id_get_buffer(id, off, 0x200);
- if (vs == NULL)
- return -1;
-
- if (fnlen > 0 && memcmp(filename, "NO NAME ", 11) != 0) {
- volume_id_set_label_raw(id, filename, fnlen);
- volume_id_set_label_string(id, filename, fnlen);
- } else if (memcmp(vs->type.fat32.label, "NO NAME ", 11) != 0) {
- volume_id_set_label_raw(id, vs->type.fat32.label, 11);
- volume_id_set_label_string(id, vs->type.fat32.label, 11);
- }
- volume_id_set_uuid(id, vs->type.fat32.serno, 0, UUID_DOS);
-
-found:
- volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
- id->type = "vfat";
- /* we think this is fat, but we make sure no other signatures are found */
- id->force_unique_result = 1;
- return 0;
-}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2025-01-18 08:08:34 +0000