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grub/grub-core/fs/fat.c
David Michael 20def1a3c3 fat: Support file modification times 
This allows comparing file ages on EFI system partitions.

Signed-off-by: David Michael <fedora.dm0@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
2020-03-10 21:52:07 +01:00

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/* fat.c - FAT filesystem */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2000,2001,2002,2003,2004,2005,2007,2008,2009 Free Software Foundation, Inc.
*
* GRUB 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 3 of the License, or
* (at your option) any later version.
*
* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/fs.h>
#include <grub/disk.h>
#include <grub/file.h>
#include <grub/types.h>
#include <grub/misc.h>
#include <grub/mm.h>
#include <grub/err.h>
#include <grub/dl.h>
#include <grub/charset.h>
#include <grub/datetime.h>
#ifndef MODE_EXFAT
#include <grub/fat.h>
#else
#include <grub/exfat.h>
#endif
#include <grub/fshelp.h>
#include <grub/i18n.h>
GRUB_MOD_LICENSE ("GPLv3+");
enum
{
GRUB_FAT_ATTR_READ_ONLY = 0x01,
GRUB_FAT_ATTR_HIDDEN = 0x02,
GRUB_FAT_ATTR_SYSTEM = 0x04,
#ifndef MODE_EXFAT
GRUB_FAT_ATTR_VOLUME_ID = 0x08,
#endif
GRUB_FAT_ATTR_DIRECTORY = 0x10,
GRUB_FAT_ATTR_ARCHIVE = 0x20,
#ifndef MODE_EXFAT
GRUB_FAT_ATTR_LONG_NAME = (GRUB_FAT_ATTR_READ_ONLY
| GRUB_FAT_ATTR_HIDDEN
| GRUB_FAT_ATTR_SYSTEM
| GRUB_FAT_ATTR_VOLUME_ID),
#endif
GRUB_FAT_ATTR_VALID = (GRUB_FAT_ATTR_READ_ONLY
| GRUB_FAT_ATTR_HIDDEN
| GRUB_FAT_ATTR_SYSTEM
| GRUB_FAT_ATTR_DIRECTORY
| GRUB_FAT_ATTR_ARCHIVE
#ifndef MODE_EXFAT
| GRUB_FAT_ATTR_VOLUME_ID
#endif
)
};
#ifdef MODE_EXFAT
typedef struct grub_exfat_bpb grub_current_fat_bpb_t;
#else
typedef struct grub_fat_bpb grub_current_fat_bpb_t;
#endif
#ifdef MODE_EXFAT
enum
{
FLAG_CONTIGUOUS = 2
};
struct grub_fat_dir_entry
{
grub_uint8_t entry_type;
union
{
grub_uint8_t placeholder[31];
struct {
grub_uint8_t secondary_count;
grub_uint16_t checksum;
grub_uint16_t attr;
grub_uint16_t reserved1;
grub_uint32_t c_time;
grub_uint32_t m_time;
grub_uint32_t a_time;
grub_uint8_t c_time_tenth;
grub_uint8_t m_time_tenth;
grub_uint8_t a_time_tenth;
grub_uint8_t reserved2[9];
} GRUB_PACKED file;
struct {
grub_uint8_t flags;
grub_uint8_t reserved1;
grub_uint8_t name_length;
grub_uint16_t name_hash;
grub_uint16_t reserved2;
grub_uint64_t valid_size;
grub_uint32_t reserved3;
grub_uint32_t first_cluster;
grub_uint64_t file_size;
} GRUB_PACKED stream_extension;
struct {
grub_uint8_t flags;
grub_uint16_t str[15];
} GRUB_PACKED file_name;
struct {
grub_uint8_t character_count;
grub_uint16_t str[15];
} GRUB_PACKED volume_label;
} GRUB_PACKED type_specific;
} GRUB_PACKED;
struct grub_fat_dir_node
{
grub_uint32_t attr;
grub_uint32_t first_cluster;
grub_uint64_t file_size;
grub_uint64_t valid_size;
int have_stream;
int is_contiguous;
};
typedef struct grub_fat_dir_node grub_fat_dir_node_t;
#else
struct grub_fat_dir_entry
{
grub_uint8_t name[11];
grub_uint8_t attr;
grub_uint8_t nt_reserved;
grub_uint8_t c_time_tenth;
grub_uint16_t c_time;
grub_uint16_t c_date;
grub_uint16_t a_date;
grub_uint16_t first_cluster_high;
grub_uint16_t w_time;
grub_uint16_t w_date;
grub_uint16_t first_cluster_low;
grub_uint32_t file_size;
} GRUB_PACKED;
struct grub_fat_long_name_entry
{
grub_uint8_t id;
grub_uint16_t name1[5];
grub_uint8_t attr;
grub_uint8_t reserved;
grub_uint8_t checksum;
grub_uint16_t name2[6];
grub_uint16_t first_cluster;
grub_uint16_t name3[2];
} GRUB_PACKED;
typedef struct grub_fat_dir_entry grub_fat_dir_node_t;
#endif
struct grub_fat_data
{
int logical_sector_bits;
grub_uint32_t num_sectors;
grub_uint32_t fat_sector;
grub_uint32_t sectors_per_fat;
int fat_size;
grub_uint32_t root_cluster;
#ifndef MODE_EXFAT
grub_uint32_t root_sector;
grub_uint32_t num_root_sectors;
#endif
int cluster_bits;
grub_uint32_t cluster_eof_mark;
grub_uint32_t cluster_sector;
grub_uint32_t num_clusters;
grub_uint32_t uuid;
};
struct grub_fshelp_node {
grub_disk_t disk;
struct grub_fat_data *data;
grub_uint8_t attr;
#ifndef MODE_EXFAT
grub_uint32_t file_size;
#else
grub_uint64_t file_size;
#endif
grub_uint32_t file_cluster;
grub_uint32_t cur_cluster_num;
grub_uint32_t cur_cluster;
#ifdef MODE_EXFAT
int is_contiguous;
#endif
};
static grub_dl_t my_mod;
#ifndef MODE_EXFAT
static int
fat_log2 (unsigned x)
{
int i;
if (x == 0)
return -1;
for (i = 0; (x & 1) == 0; i++)
x >>= 1;
if (x != 1)
return -1;
return i;
}
#endif
static struct grub_fat_data *
grub_fat_mount (grub_disk_t disk)
{
grub_current_fat_bpb_t bpb;
struct grub_fat_data *data = 0;
grub_uint32_t first_fat, magic;
if (! disk)
goto fail;
data = (struct grub_fat_data *) grub_malloc (sizeof (*data));
if (! data)
goto fail;
/* Read the BPB. */
if (grub_disk_read (disk, 0, 0, sizeof (bpb), &bpb))
goto fail;
#ifdef MODE_EXFAT
if (grub_memcmp ((const char *) bpb.oem_name, "EXFAT ",
sizeof (bpb.oem_name)) != 0)
goto fail;
#endif
/* Get the sizes of logical sectors and clusters. */
#ifdef MODE_EXFAT
data->logical_sector_bits = bpb.bytes_per_sector_shift;
#else
data->logical_sector_bits =
fat_log2 (grub_le_to_cpu16 (bpb.bytes_per_sector));
#endif
if (data->logical_sector_bits < GRUB_DISK_SECTOR_BITS
|| data->logical_sector_bits >= 16)
goto fail;
data->logical_sector_bits -= GRUB_DISK_SECTOR_BITS;
#ifdef MODE_EXFAT
data->cluster_bits = bpb.sectors_per_cluster_shift;
#else
data->cluster_bits = fat_log2 (bpb.sectors_per_cluster);
#endif
if (data->cluster_bits < 0 || data->cluster_bits > 25)
goto fail;
data->cluster_bits += data->logical_sector_bits;
/* Get information about FATs. */
#ifdef MODE_EXFAT
data->fat_sector = (grub_le_to_cpu32 (bpb.num_reserved_sectors)
<< data->logical_sector_bits);
#else
data->fat_sector = (grub_le_to_cpu16 (bpb.num_reserved_sectors)
<< data->logical_sector_bits);
#endif
if (data->fat_sector == 0)
goto fail;
#ifdef MODE_EXFAT
data->sectors_per_fat = (grub_le_to_cpu32 (bpb.sectors_per_fat)
<< data->logical_sector_bits);
#else
data->sectors_per_fat = ((bpb.sectors_per_fat_16
? grub_le_to_cpu16 (bpb.sectors_per_fat_16)
: grub_le_to_cpu32 (bpb.version_specific.fat32.sectors_per_fat_32))
<< data->logical_sector_bits);
#endif
if (data->sectors_per_fat == 0)
goto fail;
/* Get the number of sectors in this volume. */
#ifdef MODE_EXFAT
data->num_sectors = ((grub_le_to_cpu64 (bpb.num_total_sectors))
<< data->logical_sector_bits);
#else
data->num_sectors = ((bpb.num_total_sectors_16
? grub_le_to_cpu16 (bpb.num_total_sectors_16)
: grub_le_to_cpu32 (bpb.num_total_sectors_32))
<< data->logical_sector_bits);
#endif
if (data->num_sectors == 0)
goto fail;
/* Get information about the root directory. */
if (bpb.num_fats == 0)
goto fail;
#ifndef MODE_EXFAT
data->root_sector = data->fat_sector + bpb.num_fats * data->sectors_per_fat;
data->num_root_sectors
= ((((grub_uint32_t) grub_le_to_cpu16 (bpb.num_root_entries)
* sizeof (struct grub_fat_dir_entry)
+ grub_le_to_cpu16 (bpb.bytes_per_sector) - 1)
>> (data->logical_sector_bits + GRUB_DISK_SECTOR_BITS))
<< (data->logical_sector_bits));
#endif
#ifdef MODE_EXFAT
data->cluster_sector = (grub_le_to_cpu32 (bpb.cluster_offset)
<< data->logical_sector_bits);
data->num_clusters = (grub_le_to_cpu32 (bpb.cluster_count)
<< data->logical_sector_bits);
#else
data->cluster_sector = data->root_sector + data->num_root_sectors;
data->num_clusters = (((data->num_sectors - data->cluster_sector)
>> data->cluster_bits)
+ 2);
#endif
if (data->num_clusters <= 2)
goto fail;
#ifdef MODE_EXFAT
{
/* exFAT. */
data->root_cluster = grub_le_to_cpu32 (bpb.root_cluster);
data->fat_size = 32;
data->cluster_eof_mark = 0xffffffff;
if ((bpb.volume_flags & grub_cpu_to_le16_compile_time (0x1))
&& bpb.num_fats > 1)
data->fat_sector += data->sectors_per_fat;
}
#else
if (! bpb.sectors_per_fat_16)
{
/* FAT32. */
grub_uint16_t flags = grub_le_to_cpu16 (bpb.version_specific.fat32.extended_flags);
data->root_cluster = grub_le_to_cpu32 (bpb.version_specific.fat32.root_cluster);
data->fat_size = 32;
data->cluster_eof_mark = 0x0ffffff8;
if (flags & 0x80)
{
/* Get an active FAT. */
unsigned active_fat = flags & 0xf;
if (active_fat > bpb.num_fats)
goto fail;
data->fat_sector += active_fat * data->sectors_per_fat;
}
if (bpb.num_root_entries != 0 || bpb.version_specific.fat32.fs_version != 0)
goto fail;
}
else
{
/* FAT12 or FAT16. */
data->root_cluster = ~0U;
if (data->num_clusters <= 4085 + 2)
{
/* FAT12. */
data->fat_size = 12;
data->cluster_eof_mark = 0x0ff8;
}
else
{
/* FAT16. */
data->fat_size = 16;
data->cluster_eof_mark = 0xfff8;
}
}
#endif
/* More sanity checks. */
if (data->num_sectors <= data->fat_sector)
goto fail;
if (grub_disk_read (disk,
data->fat_sector,
0,
sizeof (first_fat),
&first_fat))
goto fail;
first_fat = grub_le_to_cpu32 (first_fat);
if (data->fat_size == 32)
{
first_fat &= 0x0fffffff;
magic = 0x0fffff00;
}
else if (data->fat_size == 16)
{
first_fat &= 0x0000ffff;
magic = 0xff00;
}
else
{
first_fat &= 0x00000fff;
magic = 0x0f00;
}
/* Serial number. */
#ifdef MODE_EXFAT
data->uuid = grub_le_to_cpu32 (bpb.num_serial);
#else
if (bpb.sectors_per_fat_16)
data->uuid = grub_le_to_cpu32 (bpb.version_specific.fat12_or_fat16.num_serial);
else
data->uuid = grub_le_to_cpu32 (bpb.version_specific.fat32.num_serial);
#endif
#ifndef MODE_EXFAT
/* Ignore the 3rd bit, because some BIOSes assigns 0xF0 to the media
descriptor, even if it is a so-called superfloppy (e.g. an USB key).
The check may be too strict for this kind of stupid BIOSes, as
they overwrite the media descriptor. */
if ((first_fat | 0x8) != (magic | bpb.media | 0x8))
goto fail;
#else
(void) magic;
#endif
return data;
fail:
grub_free (data);
grub_error (GRUB_ERR_BAD_FS, "not a FAT filesystem");
return 0;
}
static grub_ssize_t
grub_fat_read_data (grub_disk_t disk, grub_fshelp_node_t node,
grub_disk_read_hook_t read_hook, void *read_hook_data,
grub_off_t offset, grub_size_t len, char *buf)
{
grub_size_t size;
grub_uint32_t logical_cluster;
unsigned logical_cluster_bits;
grub_ssize_t ret = 0;
unsigned long sector;
#ifndef MODE_EXFAT
/* This is a special case. FAT12 and FAT16 doesn't have the root directory
in clusters. */
if (node->file_cluster == ~0U)
{
size = (node->data->num_root_sectors << GRUB_DISK_SECTOR_BITS) - offset;
if (size > len)
size = len;
if (grub_disk_read (disk, node->data->root_sector, offset, size, buf))
return -1;
return size;
}
#endif
#ifdef MODE_EXFAT
if (node->is_contiguous)
{
/* Read the data here. */
sector = (node->data->cluster_sector
+ ((node->file_cluster - 2)
<< node->data->cluster_bits));
disk->read_hook = read_hook;
disk->read_hook_data = read_hook_data;
grub_disk_read (disk, sector + (offset >> GRUB_DISK_SECTOR_BITS),
offset & (GRUB_DISK_SECTOR_SIZE - 1), len, buf);
disk->read_hook = 0;
if (grub_errno)
return -1;
return len;
}
#endif
/* Calculate the logical cluster number and offset. */
logical_cluster_bits = (node->data->cluster_bits
+ GRUB_DISK_SECTOR_BITS);
logical_cluster = offset >> logical_cluster_bits;
offset &= (1ULL << logical_cluster_bits) - 1;
if (logical_cluster < node->cur_cluster_num)
{
node->cur_cluster_num = 0;
node->cur_cluster = node->file_cluster;
}
while (len)
{
while (logical_cluster > node->cur_cluster_num)
{
/* Find next cluster. */
grub_uint32_t next_cluster;
grub_uint32_t fat_offset;
switch (node->data->fat_size)
{
case 32:
fat_offset = node->cur_cluster << 2;
break;
case 16:
fat_offset = node->cur_cluster << 1;
break;
default:
/* case 12: */
fat_offset = node->cur_cluster + (node->cur_cluster >> 1);
break;
}
/* Read the FAT. */
if (grub_disk_read (disk, node->data->fat_sector, fat_offset,
(node->data->fat_size + 7) >> 3,
(char *) &next_cluster))
return -1;
next_cluster = grub_le_to_cpu32 (next_cluster);
switch (node->data->fat_size)
{
case 16:
next_cluster &= 0xFFFF;
break;
case 12:
if (node->cur_cluster & 1)
next_cluster >>= 4;
next_cluster &= 0x0FFF;
break;
}
grub_dprintf ("fat", "fat_size=%d, next_cluster=%u\n",
node->data->fat_size, next_cluster);
/* Check the end. */
if (next_cluster >= node->data->cluster_eof_mark)
return ret;
if (next_cluster < 2 || next_cluster >= node->data->num_clusters)
{
grub_error (GRUB_ERR_BAD_FS, "invalid cluster %u",
next_cluster);
return -1;
}
node->cur_cluster = next_cluster;
node->cur_cluster_num++;
}
/* Read the data here. */
sector = (node->data->cluster_sector
+ ((node->cur_cluster - 2)
<< node->data->cluster_bits));
size = (1 << logical_cluster_bits) - offset;
if (size > len)
size = len;
disk->read_hook = read_hook;
disk->read_hook_data = read_hook_data;
grub_disk_read (disk, sector, offset, size, buf);
disk->read_hook = 0;
if (grub_errno)
return -1;
len -= size;
buf += size;
ret += size;
logical_cluster++;
offset = 0;
}
return ret;
}
struct grub_fat_iterate_context
{
#ifdef MODE_EXFAT
struct grub_fat_dir_node dir;
struct grub_fat_dir_entry entry;
#else
struct grub_fat_dir_entry dir;
#endif
char *filename;
grub_uint16_t *unibuf;
grub_ssize_t offset;
};
static grub_err_t
grub_fat_iterate_init (struct grub_fat_iterate_context *ctxt)
{
ctxt->offset = -sizeof (struct grub_fat_dir_entry);
#ifndef MODE_EXFAT
/* Allocate space enough to hold a long name. */
ctxt->filename = grub_malloc (0x40 * 13 * GRUB_MAX_UTF8_PER_UTF16 + 1);
ctxt->unibuf = (grub_uint16_t *) grub_malloc (0x40 * 13 * 2);
#else
ctxt->unibuf = grub_malloc (15 * 256 * 2);
ctxt->filename = grub_malloc (15 * 256 * GRUB_MAX_UTF8_PER_UTF16 + 1);
#endif
if (! ctxt->filename || ! ctxt->unibuf)
{
grub_free (ctxt->filename);
grub_free (ctxt->unibuf);
return grub_errno;
}
return GRUB_ERR_NONE;
}
static void
grub_fat_iterate_fini (struct grub_fat_iterate_context *ctxt)
{
grub_free (ctxt->filename);
grub_free (ctxt->unibuf);
}
#ifdef MODE_EXFAT
static grub_err_t
grub_fat_iterate_dir_next (grub_fshelp_node_t node,
struct grub_fat_iterate_context *ctxt)
{
grub_memset (&ctxt->dir, 0, sizeof (ctxt->dir));
while (1)
{
struct grub_fat_dir_entry *dir = &ctxt->entry;
ctxt->offset += sizeof (*dir);
if (grub_fat_read_data (node->disk, node, 0, 0, ctxt->offset, sizeof (*dir),
(char *) dir)
!= sizeof (*dir))
break;
if (dir->entry_type == 0)
break;
if (!(dir->entry_type & 0x80))
continue;
if (dir->entry_type == 0x85)
{
unsigned i, nsec, slots = 0;
nsec = dir->type_specific.file.secondary_count;
ctxt->dir.attr = grub_cpu_to_le16 (dir->type_specific.file.attr);
ctxt->dir.have_stream = 0;
for (i = 0; i < nsec; i++)
{
struct grub_fat_dir_entry sec;
ctxt->offset += sizeof (sec);
if (grub_fat_read_data (node->disk, node, 0, 0,
ctxt->offset, sizeof (sec), (char *) &sec)
!= sizeof (sec))
break;
if (!(sec.entry_type & 0x80))
continue;
if (!(sec.entry_type & 0x40))
break;
switch (sec.entry_type)
{
case 0xc0:
ctxt->dir.first_cluster = grub_cpu_to_le32 (sec.type_specific.stream_extension.first_cluster);
ctxt->dir.valid_size
= grub_cpu_to_le64 (sec.type_specific.stream_extension.valid_size);
ctxt->dir.file_size
= grub_cpu_to_le64 (sec.type_specific.stream_extension.file_size);
ctxt->dir.have_stream = 1;
ctxt->dir.is_contiguous = !!(sec.type_specific.stream_extension.flags
& grub_cpu_to_le16_compile_time (FLAG_CONTIGUOUS));
break;
case 0xc1:
{
int j;
for (j = 0; j < 15; j++)
ctxt->unibuf[slots * 15 + j]
= grub_le_to_cpu16 (sec.type_specific.file_name.str[j]);
slots++;
}
break;
default:
grub_dprintf ("exfat", "unknown secondary type 0x%02x\n",
sec.entry_type);
}
}
if (i != nsec)
{
ctxt->offset -= sizeof (*dir);
continue;
}
*grub_utf16_to_utf8 ((grub_uint8_t *) ctxt->filename, ctxt->unibuf,
slots * 15) = '\0';
return 0;
}
/* Allocation bitmap. */
if (dir->entry_type == 0x81)
continue;
/* Upcase table. */
if (dir->entry_type == 0x82)
continue;
/* Volume label. */
if (dir->entry_type == 0x83)
continue;
grub_dprintf ("exfat", "unknown primary type 0x%02x\n",
dir->entry_type);
}
return grub_errno ? : GRUB_ERR_EOF;
}
/*
* Convert a timestamp in exFAT format to seconds since the UNIX epoch
* according to sections 7.4.8 and 7.4.9 in the exFAT specification.
* https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification
*/
static int
grub_exfat_timestamp (grub_uint32_t field, grub_uint8_t msec, grub_int32_t *nix) {
struct grub_datetime datetime = {
.year = (field >> 25) + 1980,
.month = (field & 0x01E00000) >> 21,
.day = (field & 0x001F0000) >> 16,
.hour = (field & 0x0000F800) >> 11,
.minute = (field & 0x000007E0) >> 5,
.second = (field & 0x0000001F) * 2 + (msec >= 100 ? 1 : 0),
};
/* The conversion below allows seconds=60, so don't trust its validation. */
if ((field & 0x1F) > 29)
return 0;
/* Validate the 10-msec field even though it is rounded down to seconds. */
if (msec > 199)
return 0;
return grub_datetime2unixtime (&datetime, nix);
}
#else
static grub_err_t
grub_fat_iterate_dir_next (grub_fshelp_node_t node,
struct grub_fat_iterate_context *ctxt)
{
char *filep = 0;
int checksum = -1;
int slot = -1, slots = -1;
while (1)
{
unsigned i;
/* Adjust the offset. */
ctxt->offset += sizeof (ctxt->dir);
/* Read a directory entry. */
if (grub_fat_read_data (node->disk, node, 0, 0,
ctxt->offset, sizeof (ctxt->dir),
(char *) &ctxt->dir)
!= sizeof (ctxt->dir) || ctxt->dir.name[0] == 0)
break;
/* Handle long name entries. */
if (ctxt->dir.attr == GRUB_FAT_ATTR_LONG_NAME)
{
struct grub_fat_long_name_entry *long_name
= (struct grub_fat_long_name_entry *) &ctxt->dir;
grub_uint8_t id = long_name->id;
if (id & 0x40)
{
id &= 0x3f;
slots = slot = id;
checksum = long_name->checksum;
}
if (id != slot || slot == 0 || checksum != long_name->checksum)
{
checksum = -1;
continue;
}
slot--;
grub_memcpy (ctxt->unibuf + slot * 13, long_name->name1, 5 * 2);
grub_memcpy (ctxt->unibuf + slot * 13 + 5, long_name->name2, 6 * 2);
grub_memcpy (ctxt->unibuf + slot * 13 + 11, long_name->name3, 2 * 2);
continue;
}
/* Check if this entry is valid. */
if (ctxt->dir.name[0] == 0xe5 || (ctxt->dir.attr & ~GRUB_FAT_ATTR_VALID))
continue;
/* This is a workaround for Japanese. */
if (ctxt->dir.name[0] == 0x05)
ctxt->dir.name[0] = 0xe5;
if (checksum != -1 && slot == 0)
{
grub_uint8_t sum;
for (sum = 0, i = 0; i < sizeof (ctxt->dir.name); i++)
sum = ((sum >> 1) | (sum << 7)) + ctxt->dir.name[i];
if (sum == checksum)
{
int u;
for (u = 0; u < slots * 13; u++)
ctxt->unibuf[u] = grub_le_to_cpu16 (ctxt->unibuf[u]);
*grub_utf16_to_utf8 ((grub_uint8_t *) ctxt->filename,
ctxt->unibuf,
slots * 13) = '\0';
return GRUB_ERR_NONE;
}
checksum = -1;
}
/* Convert the 8.3 file name. */
filep = ctxt->filename;
if (ctxt->dir.attr & GRUB_FAT_ATTR_VOLUME_ID)
{
for (i = 0; i < sizeof (ctxt->dir.name) && ctxt->dir.name[i]; i++)
*filep++ = ctxt->dir.name[i];
while (i > 0 && ctxt->dir.name[i - 1] == ' ')
{
filep--;
i--;
}
}
else
{
for (i = 0; i < 8 && ctxt->dir.name[i]; i++)
*filep++ = grub_tolower (ctxt->dir.name[i]);
while (i > 0 && ctxt->dir.name[i - 1] == ' ')
{
filep--;
i--;
}
/* XXX should we check that dir position is 0 or 1? */
if (i > 2 || filep[0] != '.' || (i == 2 && filep[1] != '.'))
*filep++ = '.';
for (i = 8; i < 11 && ctxt->dir.name[i]; i++)
*filep++ = grub_tolower (ctxt->dir.name[i]);
while (i > 8 && ctxt->dir.name[i - 1] == ' ')
{
filep--;
i--;
}
if (i == 8)
filep--;
}
*filep = '\0';
return GRUB_ERR_NONE;
}
return grub_errno ? : GRUB_ERR_EOF;
}
/*
* Convert a date and time in FAT format to seconds since the UNIX epoch
* according to sections 11.3.5 and 11.3.6 in ECMA-107.
* https://www.ecma-international.org/publications/files/ECMA-ST/Ecma-107.pdf
*/
static int
grub_fat_timestamp (grub_uint16_t time, grub_uint16_t date, grub_int32_t *nix) {
struct grub_datetime datetime = {
.year = (date >> 9) + 1980,
.month = (date & 0x01E0) >> 5,
.day = (date & 0x001F),
.hour = (time >> 11),
.minute = (time & 0x07E0) >> 5,
.second = (time & 0x001F) * 2,
};
/* The conversion below allows seconds=60, so don't trust its validation. */
if ((time & 0x1F) > 29)
return 0;
return grub_datetime2unixtime (&datetime, nix);
}
#endif
static grub_err_t lookup_file (grub_fshelp_node_t node,
const char *name,
grub_fshelp_node_t *foundnode,
enum grub_fshelp_filetype *foundtype)
{
grub_err_t err;
struct grub_fat_iterate_context ctxt;
err = grub_fat_iterate_init (&ctxt);
if (err)
return err;
while (!(err = grub_fat_iterate_dir_next (node, &ctxt)))
{
#ifdef MODE_EXFAT
if (!ctxt.dir.have_stream)
continue;
#else
if (ctxt.dir.attr & GRUB_FAT_ATTR_VOLUME_ID)
continue;
#endif
if (grub_strcasecmp (name, ctxt.filename) == 0)
{
*foundnode = grub_malloc (sizeof (struct grub_fshelp_node));
if (!*foundnode)
return grub_errno;
(*foundnode)->attr = ctxt.dir.attr;
#ifdef MODE_EXFAT
(*foundnode)->file_size = ctxt.dir.file_size;
(*foundnode)->file_cluster = ctxt.dir.first_cluster;
(*foundnode)->is_contiguous = ctxt.dir.is_contiguous;
#else
(*foundnode)->file_size = grub_le_to_cpu32 (ctxt.dir.file_size);
(*foundnode)->file_cluster = ((grub_le_to_cpu16 (ctxt.dir.first_cluster_high) << 16)
| grub_le_to_cpu16 (ctxt.dir.first_cluster_low));
/* If directory points to root, starting cluster is 0 */
if (!(*foundnode)->file_cluster)
(*foundnode)->file_cluster = node->data->root_cluster;
#endif
(*foundnode)->cur_cluster_num = ~0U;
(*foundnode)->data = node->data;
(*foundnode)->disk = node->disk;
*foundtype = ((*foundnode)->attr & GRUB_FAT_ATTR_DIRECTORY) ? GRUB_FSHELP_DIR : GRUB_FSHELP_REG;
grub_fat_iterate_fini (&ctxt);
return GRUB_ERR_NONE;
}
}
grub_fat_iterate_fini (&ctxt);
if (err == GRUB_ERR_EOF)
err = 0;
return err;
}
static grub_err_t
grub_fat_dir (grub_device_t device, const char *path, grub_fs_dir_hook_t hook,
void *hook_data)
{
struct grub_fat_data *data = 0;
grub_disk_t disk = device->disk;
grub_fshelp_node_t found = NULL;
grub_err_t err;
struct grub_fat_iterate_context ctxt;
grub_dl_ref (my_mod);
data = grub_fat_mount (disk);
if (! data)
goto fail;
struct grub_fshelp_node root = {
.data = data,
.disk = disk,
.attr = GRUB_FAT_ATTR_DIRECTORY,
.file_size = 0,
.file_cluster = data->root_cluster,
.cur_cluster_num = ~0U,
.cur_cluster = 0,
#ifdef MODE_EXFAT
.is_contiguous = 0,
#endif
};
err = grub_fshelp_find_file_lookup (path, &root, &found, lookup_file, NULL, GRUB_FSHELP_DIR);
if (err)
goto fail;
err = grub_fat_iterate_init (&ctxt);
if (err)
goto fail;
while (!(err = grub_fat_iterate_dir_next (found, &ctxt)))
{
struct grub_dirhook_info info;
grub_memset (&info, 0, sizeof (info));
info.dir = !! (ctxt.dir.attr & GRUB_FAT_ATTR_DIRECTORY);
info.case_insensitive = 1;
#ifdef MODE_EXFAT
if (!ctxt.dir.have_stream)
continue;
info.mtimeset = grub_exfat_timestamp (grub_le_to_cpu32 (ctxt.entry.type_specific.file.m_time),
ctxt.entry.type_specific.file.m_time_tenth,
&info.mtime);
#else
if (ctxt.dir.attr & GRUB_FAT_ATTR_VOLUME_ID)
continue;
info.mtimeset = grub_fat_timestamp (grub_le_to_cpu16 (ctxt.dir.w_time),
grub_le_to_cpu16 (ctxt.dir.w_date),
&info.mtime);
#endif
if (info.mtimeset == 0)
grub_error (GRUB_ERR_OUT_OF_RANGE,
"invalid modification timestamp for %s", path);
if (hook (ctxt.filename, &info, hook_data))
break;
}
grub_fat_iterate_fini (&ctxt);
if (err == GRUB_ERR_EOF)
err = 0;
fail:
if (found != &root)
grub_free (found);
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_err_t
grub_fat_open (grub_file_t file, const char *name)
{
struct grub_fat_data *data = 0;
grub_fshelp_node_t found = NULL;
grub_err_t err;
grub_disk_t disk = file->device->disk;
grub_dl_ref (my_mod);
data = grub_fat_mount (disk);
if (! data)
goto fail;
struct grub_fshelp_node root = {
.data = data,
.disk = disk,
.attr = GRUB_FAT_ATTR_DIRECTORY,
.file_size = 0,
.file_cluster = data->root_cluster,
.cur_cluster_num = ~0U,
.cur_cluster = 0,
#ifdef MODE_EXFAT
.is_contiguous = 0,
#endif
};
err = grub_fshelp_find_file_lookup (name, &root, &found, lookup_file, NULL, GRUB_FSHELP_REG);
if (err)
goto fail;
file->data = found;
file->size = found->file_size;
return GRUB_ERR_NONE;
fail:
if (found != &root)
grub_free (found);
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_ssize_t
grub_fat_read (grub_file_t file, char *buf, grub_size_t len)
{
return grub_fat_read_data (file->device->disk, file->data,
file->read_hook, file->read_hook_data,
file->offset, len, buf);
}
static grub_err_t
grub_fat_close (grub_file_t file)
{
grub_fshelp_node_t node = file->data;
grub_free (node->data);
grub_free (node);
grub_dl_unref (my_mod);
return grub_errno;
}
#ifdef MODE_EXFAT
static grub_err_t
grub_fat_label (grub_device_t device, char **label)
{
struct grub_fat_dir_entry dir;
grub_ssize_t offset = -sizeof(dir);
grub_disk_t disk = device->disk;
struct grub_fshelp_node root = {
.disk = disk,
.attr = GRUB_FAT_ATTR_DIRECTORY,
.file_size = 0,
.cur_cluster_num = ~0U,
.cur_cluster = 0,
.is_contiguous = 0,
};
root.data = grub_fat_mount (disk);
if (! root.data)
return grub_errno;
root.file_cluster = root.data->root_cluster;
*label = NULL;
while (1)
{
offset += sizeof (dir);
if (grub_fat_read_data (disk, &root, 0, 0,
offset, sizeof (dir), (char *) &dir)
!= sizeof (dir))
break;
if (dir.entry_type == 0)
break;
if (!(dir.entry_type & 0x80))
continue;
/* Volume label. */
if (dir.entry_type == 0x83)
{
grub_size_t chc;
grub_uint16_t t[ARRAY_SIZE (dir.type_specific.volume_label.str)];
grub_size_t i;
*label = grub_malloc (ARRAY_SIZE (dir.type_specific.volume_label.str)
* GRUB_MAX_UTF8_PER_UTF16 + 1);
if (!*label)
{
grub_free (root.data);
return grub_errno;
}
chc = dir.type_specific.volume_label.character_count;
if (chc > ARRAY_SIZE (dir.type_specific.volume_label.str))
chc = ARRAY_SIZE (dir.type_specific.volume_label.str);
for (i = 0; i < chc; i++)
t[i] = grub_le_to_cpu16 (dir.type_specific.volume_label.str[i]);
*grub_utf16_to_utf8 ((grub_uint8_t *) *label, t, chc) = '\0';
}
}
grub_free (root.data);
return grub_errno;
}
#else
static grub_err_t
grub_fat_label (grub_device_t device, char **label)
{
grub_disk_t disk = device->disk;
grub_err_t err;
struct grub_fat_iterate_context ctxt;
struct grub_fshelp_node root = {
.disk = disk,
.attr = GRUB_FAT_ATTR_DIRECTORY,
.file_size = 0,
.cur_cluster_num = ~0U,
.cur_cluster = 0,
};
*label = 0;
grub_dl_ref (my_mod);
root.data = grub_fat_mount (disk);
if (! root.data)
goto fail;
root.file_cluster = root.data->root_cluster;
err = grub_fat_iterate_init (&ctxt);
if (err)
goto fail;
while (!(err = grub_fat_iterate_dir_next (&root, &ctxt)))
if ((ctxt.dir.attr & ~GRUB_FAT_ATTR_ARCHIVE) == GRUB_FAT_ATTR_VOLUME_ID)
{
*label = grub_strdup (ctxt.filename);
break;
}
grub_fat_iterate_fini (&ctxt);
fail:
grub_dl_unref (my_mod);
grub_free (root.data);
return grub_errno;
}
#endif
static grub_err_t
grub_fat_uuid (grub_device_t device, char **uuid)
{
struct grub_fat_data *data;
grub_disk_t disk = device->disk;
grub_dl_ref (my_mod);
data = grub_fat_mount (disk);
if (data)
{
char *ptr;
*uuid = grub_xasprintf ("%04x-%04x",
(grub_uint16_t) (data->uuid >> 16),
(grub_uint16_t) data->uuid);
for (ptr = *uuid; ptr && *ptr; ptr++)
*ptr = grub_toupper (*ptr);
}
else
*uuid = NULL;
grub_dl_unref (my_mod);
grub_free (data);
return grub_errno;
}
#ifdef GRUB_UTIL
#ifndef MODE_EXFAT
grub_disk_addr_t
grub_fat_get_cluster_sector (grub_disk_t disk, grub_uint64_t *sec_per_lcn)
#else
grub_disk_addr_t
grub_exfat_get_cluster_sector (grub_disk_t disk, grub_uint64_t *sec_per_lcn)
#endif
{
grub_disk_addr_t ret;
struct grub_fat_data *data;
data = grub_fat_mount (disk);
if (!data)
return 0;
ret = data->cluster_sector;
*sec_per_lcn = 1ULL << data->cluster_bits;
grub_free (data);
return ret;
}
#endif
static struct grub_fs grub_fat_fs =
{
#ifdef MODE_EXFAT
.name = "exfat",
#else
.name = "fat",
#endif
.fs_dir = grub_fat_dir,
.fs_open = grub_fat_open,
.fs_read = grub_fat_read,
.fs_close = grub_fat_close,
.fs_label = grub_fat_label,
.fs_uuid = grub_fat_uuid,
#ifdef GRUB_UTIL
#ifdef MODE_EXFAT
/* ExFAT BPB is 30 larger than FAT32 one. */
.reserved_first_sector = 0,
#else
.reserved_first_sector = 1,
#endif
.blocklist_install = 1,
#endif
.next = 0
};
#ifdef MODE_EXFAT
GRUB_MOD_INIT(exfat)
#else
GRUB_MOD_INIT(fat)
#endif
{
COMPILE_TIME_ASSERT (sizeof (struct grub_fat_dir_entry) == 32);
grub_fs_register (&grub_fat_fs);
my_mod = mod;
}
#ifdef MODE_EXFAT
GRUB_MOD_FINI(exfat)
#else
GRUB_MOD_FINI(fat)
#endif
{
grub_fs_unregister (&grub_fat_fs);
}
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