+++ /dev/null
-/*
- * Copyright (C) 1999 by Andries Brouwer
- * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
- * Copyright (C) 2001 by Andreas Dilger
- * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
- * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
- *
- * This file may be redistributed under the terms of the
- * GNU Lesser General Public License.
- */
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <errno.h>
-#include <ctype.h>
-#include <stdint.h>
-
-#include "superblocks.h"
-
-/* Yucky misaligned values */
-struct vfat_super_block {
-/* 00*/ unsigned char vs_ignored[3];
-/* 03*/ unsigned char vs_sysid[8];
-/* 0b*/ unsigned char vs_sector_size[2];
-/* 0d*/ uint8_t vs_cluster_size;
-/* 0e*/ uint16_t vs_reserved;
-/* 10*/ uint8_t vs_fats;
-/* 11*/ unsigned char vs_dir_entries[2];
-/* 13*/ unsigned char vs_sectors[2];
-/* 15*/ unsigned char vs_media;
-/* 16*/ uint16_t vs_fat_length;
-/* 18*/ uint16_t vs_secs_track;
-/* 1a*/ uint16_t vs_heads;
-/* 1c*/ uint32_t vs_hidden;
-/* 20*/ uint32_t vs_total_sect;
-/* 24*/ uint32_t vs_fat32_length;
-/* 28*/ uint16_t vs_flags;
-/* 2a*/ uint8_t vs_version[2];
-/* 2c*/ uint32_t vs_root_cluster;
-/* 30*/ uint16_t vs_fsinfo_sector;
-/* 32*/ uint16_t vs_backup_boot;
-/* 34*/ uint16_t vs_reserved2[6];
-/* 40*/ unsigned char vs_unknown[3];
-/* 43*/ unsigned char vs_serno[4];
-/* 47*/ unsigned char vs_label[11];
-/* 52*/ unsigned char vs_magic[8];
-/* 5a*/ unsigned char vs_dummy2[0x1fe - 0x5a];
-/*1fe*/ unsigned char vs_pmagic[2];
-} __attribute__((packed));
-
-/* Yucky misaligned values */
-struct msdos_super_block {
-/* 00*/ unsigned char ms_ignored[3];
-/* 03*/ unsigned char ms_sysid[8];
-/* 0b*/ unsigned char ms_sector_size[2];
-/* 0d*/ uint8_t ms_cluster_size;
-/* 0e*/ uint16_t ms_reserved;
-/* 10*/ uint8_t ms_fats;
-/* 11*/ unsigned char ms_dir_entries[2];
-/* 13*/ unsigned char ms_sectors[2]; /* =0 iff V3 or later */
-/* 15*/ unsigned char ms_media;
-/* 16*/ uint16_t ms_fat_length; /* Sectors per FAT */
-/* 18*/ uint16_t ms_secs_track;
-/* 1a*/ uint16_t ms_heads;
-/* 1c*/ uint32_t ms_hidden;
-/* V3 BPB */
-/* 20*/ uint32_t ms_total_sect; /* iff ms_sectors == 0 */
-/* V4 BPB */
-/* 24*/ unsigned char ms_unknown[3]; /* Phys drive no., resvd, V4 sig (0x29) */
-/* 27*/ unsigned char ms_serno[4];
-/* 2b*/ unsigned char ms_label[11];
-/* 36*/ unsigned char ms_magic[8];
-/* 3e*/ unsigned char ms_dummy2[0x1fe - 0x3e];
-/*1fe*/ unsigned char ms_pmagic[2];
-} __attribute__((packed));
-
-struct vfat_dir_entry {
- uint8_t name[11];
- uint8_t attr;
- uint16_t time_creat;
- uint16_t date_creat;
- uint16_t time_acc;
- uint16_t date_acc;
- uint16_t cluster_high;
- uint16_t time_write;
- uint16_t date_write;
- uint16_t cluster_low;
- uint32_t size;
-} __attribute__((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];
-} __attribute__((packed));
-
-/* maximum number of clusters */
-#define FAT12_MAX 0xFF4
-#define FAT16_MAX 0xFFF4
-#define FAT32_MAX 0x0FFFFFF6
-
-#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
-
-static const char *no_name = "NO NAME ";
-
-#define unaligned_le16(x) \
- (((unsigned char *) x)[0] + (((unsigned char *) x)[1] << 8))
-
-/*
- * Look for LABEL (name) in the FAT root directory.
- */
-static unsigned char *search_fat_label(blkid_probe pr,
- uint64_t offset, uint32_t entries)
-{
- struct vfat_dir_entry *ent, *dir = NULL;
- uint32_t i;
-
- DBG(DEBUG_LOWPROBE,
- printf("\tlook for label in root-dir "
- "(entries: %d, offset: %jd)\n", entries, offset));
-
- if (!blkid_probe_is_tiny(pr)) {
- /* large disk, read whole root directory */
- dir = (struct vfat_dir_entry *)
- blkid_probe_get_buffer(pr,
- offset,
- (blkid_loff_t) entries *
- sizeof(struct vfat_dir_entry));
- if (!dir)
- return NULL;
- }
-
- for (i = 0; i < entries; i++) {
- /*
- * The root directory could be relatively large (4-16kB).
- * Fortunately, the LABEL is usually the first entry in the
- * directory. On tiny disks we call read() per entry.
- */
- if (!dir)
- ent = (struct vfat_dir_entry *)
- blkid_probe_get_buffer(pr,
- (blkid_loff_t) offset + (i *
- sizeof(struct vfat_dir_entry)),
- sizeof(struct vfat_dir_entry));
- else
- ent = &dir[i];
-
- if (!ent || ent->name[0] == 0x00)
- break;
-
- if ((ent->name[0] == FAT_ENTRY_FREE) ||
- (ent->cluster_high != 0 || ent->cluster_low != 0) ||
- ((ent->attr & FAT_ATTR_MASK) == FAT_ATTR_LONG_NAME))
- continue;
-
- if ((ent->attr & (FAT_ATTR_VOLUME_ID | FAT_ATTR_DIR)) ==
- FAT_ATTR_VOLUME_ID) {
- DBG(DEBUG_LOWPROBE,
- printf("\tfound fs LABEL at entry %d\n", i));
- return ent->name;
- }
- }
- return NULL;
-}
-
-static int fat_valid_superblock(const struct blkid_idmag *mag,
- struct msdos_super_block *ms,
- struct vfat_super_block *vs,
- uint32_t *cluster_count, uint32_t *fat_size)
-{
- uint16_t sector_size, dir_entries, reserved;
- uint32_t sect_count, __fat_size, dir_size, __cluster_count, fat_length;
- uint32_t max_count;
-
- /* extra check for FATs without magic strings */
- if (mag->len <= 2) {
- /* Old floppies have a valid MBR signature */
- if (ms->ms_pmagic[0] != 0x55 || ms->ms_pmagic[1] != 0xAA)
- return 0;
-
- /*
- * OS/2 and apparently DFSee will place a FAT12/16-like
- * pseudo-superblock in the first 512 bytes of non-FAT
- * filesystems --- at least JFS and HPFS, and possibly others.
- * So we explicitly check for those filesystems at the
- * FAT12/16 filesystem magic field identifier, and if they are
- * present, we rule this out as a FAT filesystem, despite the
- * FAT-like pseudo-header.
- */
- if ((memcmp(ms->ms_magic, "JFS ", 8) == 0) ||
- (memcmp(ms->ms_magic, "HPFS ", 8) == 0))
- return 0;
- }
-
- /* fat counts(Linux kernel expects at least 1 FAT table) */
- if (!ms->ms_fats)
- return 0;
- if (!ms->ms_reserved)
- return 0;
- if (!(0xf8 <= ms->ms_media || ms->ms_media == 0xf0))
- return 0;
- if (!is_power_of_2(ms->ms_cluster_size))
- return 0;
-
- sector_size = unaligned_le16(&ms->ms_sector_size);
- if (!is_power_of_2(sector_size) ||
- sector_size < 512 || sector_size > 4096)
- return 0;
-
- dir_entries = unaligned_le16(&ms->ms_dir_entries);
- reserved = le16_to_cpu(ms->ms_reserved);
- sect_count = unaligned_le16(&ms->ms_sectors);
-
- if (sect_count == 0)
- sect_count = le32_to_cpu(ms->ms_total_sect);
-
- fat_length = le16_to_cpu(ms->ms_fat_length);
- if (fat_length == 0)
- fat_length = le32_to_cpu(vs->vs_fat32_length);
-
- __fat_size = fat_length * ms->ms_fats;
- dir_size = ((dir_entries * sizeof(struct vfat_dir_entry)) +
- (sector_size-1)) / sector_size;
-
- __cluster_count = (sect_count - (reserved + __fat_size + dir_size)) /
- ms->ms_cluster_size;
- if (!ms->ms_fat_length && vs->vs_fat32_length)
- max_count = FAT32_MAX;
- else
- max_count = __cluster_count > FAT12_MAX ? FAT16_MAX : FAT12_MAX;
-
- if (__cluster_count > max_count)
- return 0;
-
- if (fat_size)
- *fat_size = __fat_size;
- if (cluster_count)
- *cluster_count = __cluster_count;
-
- return 1; /* valid */
-}
-
-/*
- * This function is used by MBR partition table parser to avoid
- * misinterpretation of FAT filesystem.
- */
-/*static int blkid_probe_is_vfat(blkid_probe pr)
-{
- struct vfat_super_block *vs;
- struct msdos_super_block *ms;
- const struct blkid_idmag *mag = NULL;
-
- if (blkid_probe_get_idmag(pr, &vfat_idinfo, NULL, &mag) || !mag)
- return 0;
-
- ms = blkid_probe_get_sb(pr, mag, struct msdos_super_block);
- if (!ms)
- return 0;
- vs = blkid_probe_get_sb(pr, mag, struct vfat_super_block);
- if (!vs)
- return 0;
-
- return fat_valid_superblock(mag, ms, vs, NULL, NULL);
-}*/
-static struct vfat_super_block vs;
-static struct msdos_super_block ms;
-
-static int set_label(blkid_probe pr, unsigned char *vol_label)
-{
- unsigned char *c;
-
- for (c = vol_label + 10; c >= vol_label && *c == ' '; c--)
- *c = 0;
-
- if (!*vol_label)
- return 0;
-
- return blkid_probe_set_label(pr, vol_label, 11);
-}
-
-/* FAT label extraction from the root directory taken from Kay
- * Sievers's volume_id library */
-static int probe_vfat(blkid_probe pr, const struct blkid_idmag *mag)
-{
- struct vfat_super_block *_vs;
- struct msdos_super_block *_ms;
- const unsigned char *vol_label = 0;
- unsigned char *vol_serno = NULL, vol_label_buf[11];
- uint16_t sector_size = 0, reserved;
- uint32_t cluster_count, fat_size;
- const char *version = NULL;
-
- _ms = blkid_probe_get_sb(pr, mag, struct msdos_super_block);
- if (!_ms)
- return 0;
- _vs = blkid_probe_get_sb(pr, mag, struct vfat_super_block);
- if (!_vs)
- return 0;
- memcpy(&ms, _ms, sizeof(struct vfat_super_block));
- memcpy(&vs, _vs, sizeof(struct msdos_super_block));
- if (!fat_valid_superblock(mag, &ms, &vs, &cluster_count, &fat_size))
- return 1;
-
- sector_size = unaligned_le16(&ms.ms_sector_size);
- reserved = le16_to_cpu(ms.ms_reserved);
-
- if (ms.ms_fat_length) {
- /* the label may be an attribute in the root directory */
- uint32_t root_start = (reserved + fat_size) * sector_size;
- uint32_t root_dir_entries = unaligned_le16(&vs.vs_dir_entries);
-
- vol_label = search_fat_label(pr, root_start, root_dir_entries);
- if (vol_label) {
- memcpy(vol_label_buf, vol_label, 11);
- vol_label = vol_label_buf;
- }
-
- if (!vol_label || !memcmp(vol_label, no_name, 11))
- vol_label = ms.ms_label;
- vol_serno = ms.ms_serno;
-
- blkid_probe_set_value(pr, "SEC_TYPE", (unsigned char *) "msdos",
- sizeof("msdos"));
-
- if (cluster_count < FAT12_MAX)
- version = "FAT12";
- else if (cluster_count < FAT16_MAX)
- version = "FAT16";
-
- } else if (vs.vs_fat32_length) {
- unsigned char *buf;
- uint16_t fsinfo_sect;
- int maxloop = 100;
-
- /* Search the FAT32 root dir for the label attribute */
- uint32_t buf_size = vs.vs_cluster_size * sector_size;
- uint32_t start_data_sect = reserved + fat_size;
- uint32_t entries = le32_to_cpu(vs.vs_fat32_length) *
- sector_size / sizeof(uint32_t);
- uint32_t next = le32_to_cpu(vs.vs_root_cluster);
-
- while (next && next < entries && --maxloop) {
- uint32_t next_sect_off;
- uint64_t next_off, fat_entry_off;
- int count;
-
- next_sect_off = (next - 2) * le32_to_cpu(vs.vs_cluster_size);
- next_off = (uint64_t)(start_data_sect + next_sect_off) *
- sector_size;
-
- count = buf_size / sizeof(struct vfat_dir_entry);
-
- vol_label = search_fat_label(pr, next_off, count);
- if (vol_label) {
- memcpy(vol_label_buf, vol_label, 11);
- vol_label = vol_label_buf;
- break;
- }
-
- /* get FAT entry */
- fat_entry_off = ((uint64_t) reserved * sector_size) +
- (next * sizeof(uint32_t));
- buf = blkid_probe_get_buffer(pr, fat_entry_off, buf_size);
- if (buf == NULL)
- break;
-
- /* set next cluster */
- next = le32_to_cpu(*((uint32_t *) buf)) & 0x0fffffff;
- }
-
- version = "FAT32";
-
- if (!vol_label || !memcmp(vol_label, no_name, 11))
- vol_label = NULL;
- vol_serno = vs.vs_serno;
-
- /*
- * 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.vs_fsinfo_sector);
- if (fsinfo_sect) {
- struct fat32_fsinfo *fsinfo;
-
- buf = blkid_probe_get_buffer(pr,
- (blkid_loff_t) fsinfo_sect * sector_size,
- sizeof(struct fat32_fsinfo));
- if (buf == NULL)
- return -1;
-
- fsinfo = (struct fat32_fsinfo *) buf;
- if (memcmp(fsinfo->signature1, "\x52\x52\x61\x41", 4) != 0 &&
- memcmp(fsinfo->signature1, "\x52\x52\x64\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;
- }
- }
-
- if (vol_label && memcmp(vol_label, no_name, 11))
- set_label(pr, (unsigned char *) vol_label);
-
- /* We can't just print them as %04X, because they are unaligned */
- if (vol_serno)
- blkid_probe_sprintf_uuid(pr, vol_serno, 4, "%02x%02x-%02x%02x",
- vol_serno[3], vol_serno[2], vol_serno[1], vol_serno[0]);
- if (version)
- blkid_probe_set_version(pr, version);
-
- return 0;
-}
-
-
-const struct blkid_idinfo vfat_idinfo =
-{
- .name = "vfat",
- .usage = BLKID_USAGE_FILESYSTEM,
- .probefunc = probe_vfat,
- .magics =
- {
- { .magic = "MSWIN", .len = 5, .sboff = 0x52 },
- { .magic = "FAT32 ", .len = 8, .sboff = 0x52 },
- { .magic = "MSDOS", .len = 5, .sboff = 0x36 },
- { .magic = "FAT16 ", .len = 8, .sboff = 0x36 },
- { .magic = "FAT12 ", .len = 8, .sboff = 0x36 },
- { .magic = "FAT ", .len = 8, .sboff = 0x36 },
- { .magic = "\353", .len = 1, },
- { .magic = "\351", .len = 1, },
- { .magic = "\125\252", .len = 2, .sboff = 0x1fe },
- { NULL }
- }
-};
-
projects / project / ubox.git / blobdiff