grub/grub-core/fs/affs.c
2013-10-18 16:47:30 +02:00

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/* affs.c - Amiga Fast FileSystem. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2005,2006,2007,2008,2009 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/err.h>
#include <grub/file.h>
#include <grub/mm.h>
#include <grub/misc.h>
#include <grub/disk.h>
#include <grub/dl.h>
#include <grub/types.h>
#include <grub/fshelp.h>
#include <grub/charset.h>
GRUB_MOD_LICENSE ("GPLv3+");
/* The affs bootblock. */
struct grub_affs_bblock
{
grub_uint8_t type[3];
grub_uint8_t flags;
grub_uint32_t checksum;
grub_uint32_t rootblock;
} __attribute__ ((packed));
/* Set if the filesystem is a AFFS filesystem. Otherwise this is an
OFS filesystem. */
#define GRUB_AFFS_FLAG_FFS 1
/* The affs rootblock. */
struct grub_affs_rblock
{
grub_uint32_t type;
grub_uint8_t unused1[8];
grub_uint32_t htsize;
grub_uint32_t unused2;
grub_uint32_t checksum;
grub_uint32_t hashtable[1];
} __attribute__ ((packed));
struct grub_affs_time
{
grub_int32_t day;
grub_uint32_t min;
grub_uint32_t hz;
} __attribute__ ((packed));
/* The second part of a file header block. */
struct grub_affs_file
{
grub_uint8_t unused1[12];
grub_uint32_t size;
grub_uint8_t unused2[92];
struct grub_affs_time mtime;
grub_uint8_t namelen;
grub_uint8_t name[30];
grub_uint8_t unused3[5];
grub_uint32_t hardlink;
grub_uint32_t unused4[6];
grub_uint32_t next;
grub_uint32_t parent;
grub_uint32_t extension;
grub_uint32_t type;
} __attribute__ ((packed));
/* The location of `struct grub_affs_file' relative to the end of a
file header block. */
#define GRUB_AFFS_FILE_LOCATION 200
/* The offset in both the rootblock and the file header block for the
hashtable, symlink and block pointers (all synonyms). */
#define GRUB_AFFS_HASHTABLE_OFFSET 24
#define GRUB_AFFS_BLOCKPTR_OFFSET 24
#define GRUB_AFFS_SYMLINK_OFFSET 24
enum
{
GRUB_AFFS_FILETYPE_DIR = 2,
GRUB_AFFS_FILETYPE_SYMLINK = 3,
GRUB_AFFS_FILETYPE_HARDLINK = 0xfffffffc,
GRUB_AFFS_FILETYPE_REG = 0xfffffffd
};
#define AFFS_MAX_LOG_BLOCK_SIZE 4
#define AFFS_MAX_SUPERBLOCK 1
struct grub_fshelp_node
{
struct grub_affs_data *data;
grub_uint32_t block;
struct grub_fshelp_node *parent;
struct grub_affs_file di;
grub_uint32_t *block_cache;
grub_uint32_t last_block_cache;
};
/* Information about a "mounted" affs filesystem. */
struct grub_affs_data
{
struct grub_affs_bblock bblock;
struct grub_fshelp_node diropen;
grub_disk_t disk;
/* Log blocksize in sectors. */
int log_blocksize;
/* The number of entries in the hashtable. */
unsigned int htsize;
};
static grub_dl_t my_mod;
static grub_disk_addr_t
grub_affs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
{
grub_uint32_t target, curblock;
grub_uint32_t pos;
struct grub_affs_file file;
struct grub_affs_data *data = node->data;
grub_uint64_t mod;
if (!node->block_cache)
{
node->block_cache = grub_malloc (((grub_be_to_cpu32 (node->di.size)
>> (9 + node->data->log_blocksize))
/ data->htsize + 2)
* sizeof (node->block_cache[0]));
if (!node->block_cache)
return -1;
node->last_block_cache = 0;
node->block_cache[0] = node->block;
}
/* Files are at most 2G on AFFS, so no need for 64-bit division. */
target = (grub_uint32_t) fileblock / data->htsize;
mod = (grub_uint32_t) fileblock % data->htsize;
/* Find the block that points to the fileblock we are looking up by
following the chain until the right table is reached. */
for (curblock = node->last_block_cache + 1; curblock < target + 1; curblock++)
{
grub_disk_read (data->disk,
(((grub_uint64_t) node->block_cache[curblock - 1] + 1)
<< data->log_blocksize) - 1,
GRUB_DISK_SECTOR_SIZE - GRUB_AFFS_FILE_LOCATION,
sizeof (file), &file);
if (grub_errno)
return 0;
node->block_cache[curblock] = grub_be_to_cpu32 (file.extension);
node->last_block_cache = curblock;
}
/* Translate the fileblock to the block within the right table. */
grub_disk_read (data->disk, (grub_uint64_t) node->block_cache[target]
<< data->log_blocksize,
GRUB_AFFS_BLOCKPTR_OFFSET
+ (data->htsize - mod - 1) * sizeof (pos),
sizeof (pos), &pos);
if (grub_errno)
return 0;
return grub_be_to_cpu32 (pos);
}
static struct grub_affs_data *
grub_affs_mount (grub_disk_t disk)
{
struct grub_affs_data *data;
grub_uint32_t *rootblock = 0;
struct grub_affs_rblock *rblock = 0;
int log_blocksize = 0;
int bsnum = 0;
data = grub_zalloc (sizeof (struct grub_affs_data));
if (!data)
return 0;
for (bsnum = 0; bsnum < AFFS_MAX_SUPERBLOCK + 1; bsnum++)
{
/* Read the bootblock. */
grub_disk_read (disk, bsnum, 0, sizeof (struct grub_affs_bblock),
&data->bblock);
if (grub_errno)
goto fail;
/* Make sure this is an affs filesystem. */
if (grub_strncmp ((char *) (data->bblock.type), "DOS", 3) != 0
/* Test if the filesystem is a OFS filesystem. */
|| !(data->bblock.flags & GRUB_AFFS_FLAG_FFS))
continue;
/* No sane person uses more than 8KB for a block. At least I hope
for that person because in that case this won't work. */
if (!rootblock)
rootblock = grub_malloc (GRUB_DISK_SECTOR_SIZE
<< AFFS_MAX_LOG_BLOCK_SIZE);
if (!rootblock)
goto fail;
rblock = (struct grub_affs_rblock *) rootblock;
/* The filesystem blocksize is not stored anywhere in the filesystem
itself. One way to determine it is try reading blocks for the
rootblock until the checksum is correct. */
for (log_blocksize = 0; log_blocksize <= AFFS_MAX_LOG_BLOCK_SIZE;
log_blocksize++)
{
grub_uint32_t *currblock = rootblock;
unsigned int i;
grub_uint32_t checksum = 0;
/* Read the rootblock. */
grub_disk_read (disk,
(grub_uint64_t) grub_be_to_cpu32 (data->bblock.rootblock)
<< log_blocksize, 0,
GRUB_DISK_SECTOR_SIZE << log_blocksize, rootblock);
if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
{
grub_errno = 0;
break;
}
if (grub_errno)
goto fail;
if (rblock->type != grub_cpu_to_be32_compile_time (2)
|| rblock->htsize == 0
|| currblock[(GRUB_DISK_SECTOR_SIZE << log_blocksize)
/ sizeof (*currblock) - 1]
!= grub_cpu_to_be32_compile_time (1))
continue;
for (i = 0; i < (GRUB_DISK_SECTOR_SIZE << log_blocksize)
/ sizeof (*currblock);
i++)
checksum += grub_be_to_cpu32 (currblock[i]);
if (checksum == 0)
{
data->log_blocksize = log_blocksize;
data->disk = disk;
data->htsize = grub_be_to_cpu32 (rblock->htsize);
data->diropen.data = data;
data->diropen.block = grub_be_to_cpu32 (data->bblock.rootblock);
data->diropen.parent = NULL;
grub_memcpy (&data->diropen.di, rootblock,
sizeof (data->diropen.di));
grub_free (rootblock);
return data;
}
}
}
fail:
if (grub_errno == GRUB_ERR_NONE || grub_errno == GRUB_ERR_OUT_OF_RANGE)
grub_error (GRUB_ERR_BAD_FS, "not an AFFS filesystem");
grub_free (data);
grub_free (rootblock);
return 0;
}
static char *
grub_affs_read_symlink (grub_fshelp_node_t node)
{
struct grub_affs_data *data = node->data;
grub_uint8_t *latin1, *utf8;
const grub_size_t symlink_size = ((GRUB_DISK_SECTOR_SIZE
<< data->log_blocksize) - GRUB_AFFS_SYMLINK_OFFSET);
latin1 = grub_malloc (symlink_size + 1);
if (!latin1)
return 0;
grub_disk_read (data->disk,
(grub_uint64_t) node->block << data->log_blocksize,
GRUB_AFFS_SYMLINK_OFFSET,
symlink_size, latin1);
if (grub_errno)
{
grub_free (latin1);
return 0;
}
latin1[symlink_size] = 0;
utf8 = grub_malloc (symlink_size * GRUB_MAX_UTF8_PER_LATIN1 + 1);
if (!utf8)
{
grub_free (latin1);
return 0;
}
*grub_latin1_to_utf8 (utf8, latin1, symlink_size) = '\0';
grub_dprintf ("affs", "Symlink: `%s'\n", utf8);
grub_free (latin1);
if (utf8[0] == ':')
utf8[0] = '/';
return (char *) utf8;
}
/* Helper for grub_affs_iterate_dir. */
static int
grub_affs_create_node (grub_fshelp_node_t dir,
grub_fshelp_iterate_dir_hook_t hook, void *hook_data,
struct grub_fshelp_node **node,
grub_uint32_t **hashtable,
grub_uint32_t block, const struct grub_affs_file *fil)
{
struct grub_affs_data *data = dir->data;
int type = GRUB_FSHELP_REG;
grub_uint8_t name_u8[sizeof (fil->name) * GRUB_MAX_UTF8_PER_LATIN1 + 1];
grub_size_t len;
unsigned int nest;
*node = grub_zalloc (sizeof (**node));
if (!*node)
{
grub_free (*hashtable);
return 1;
}
(*node)->data = data;
(*node)->block = block;
(*node)->parent = dir;
len = fil->namelen;
if (len > sizeof (fil->name))
len = sizeof (fil->name);
*grub_latin1_to_utf8 (name_u8, fil->name, len) = '\0';
(*node)->di = *fil;
for (nest = 0; nest < 8; nest++)
{
switch ((*node)->di.type)
{
case grub_cpu_to_be32_compile_time (GRUB_AFFS_FILETYPE_REG):
type = GRUB_FSHELP_REG;
break;
case grub_cpu_to_be32_compile_time (GRUB_AFFS_FILETYPE_DIR):
type = GRUB_FSHELP_DIR;
break;
case grub_cpu_to_be32_compile_time (GRUB_AFFS_FILETYPE_SYMLINK):
type = GRUB_FSHELP_SYMLINK;
break;
case grub_cpu_to_be32_compile_time (GRUB_AFFS_FILETYPE_HARDLINK):
{
grub_err_t err;
(*node)->block = grub_be_to_cpu32 ((*node)->di.hardlink);
err = grub_disk_read (data->disk,
(((grub_uint64_t) (*node)->block + 1) << data->log_blocksize)
- 1,
GRUB_DISK_SECTOR_SIZE - GRUB_AFFS_FILE_LOCATION,
sizeof ((*node)->di), (char *) &(*node)->di);
if (err)
return 1;
continue;
}
default:
return 0;
}
break;
}
if (nest == 8)
return 0;
type |= GRUB_FSHELP_CASE_INSENSITIVE;
if (hook ((char *) name_u8, type, *node, hook_data))
{
grub_free (*hashtable);
*node = 0;
return 1;
}
*node = 0;
return 0;
}
static int
grub_affs_iterate_dir (grub_fshelp_node_t dir,
grub_fshelp_iterate_dir_hook_t hook, void *hook_data)
{
unsigned int i;
struct grub_affs_file file;
struct grub_fshelp_node *node = 0;
struct grub_affs_data *data = dir->data;
grub_uint32_t *hashtable;
/* Create the directory entries for `.' and `..'. */
node = grub_zalloc (sizeof (*node));
if (!node)
return 1;
*node = *dir;
if (hook (".", GRUB_FSHELP_DIR, node, hook_data))
return 1;
if (dir->parent)
{
node = grub_zalloc (sizeof (*node));
if (!node)
return 1;
*node = *dir->parent;
if (hook ("..", GRUB_FSHELP_DIR, node, hook_data))
return 1;
}
hashtable = grub_zalloc (data->htsize * sizeof (*hashtable));
if (!hashtable)
return 1;
grub_disk_read (data->disk,
(grub_uint64_t) dir->block << data->log_blocksize,
GRUB_AFFS_HASHTABLE_OFFSET,
data->htsize * sizeof (*hashtable), (char *) hashtable);
if (grub_errno)
goto fail;
for (i = 0; i < data->htsize; i++)
{
grub_uint32_t next;
if (!hashtable[i])
continue;
/* Every entry in the hashtable can be chained. Read the entire
chain. */
next = grub_be_to_cpu32 (hashtable[i]);
while (next)
{
grub_disk_read (data->disk,
(((grub_uint64_t) next + 1) << data->log_blocksize)
- 1,
GRUB_DISK_SECTOR_SIZE - GRUB_AFFS_FILE_LOCATION,
sizeof (file), (char *) &file);
if (grub_errno)
goto fail;
if (grub_affs_create_node (dir, hook, hook_data, &node, &hashtable,
next, &file))
return 1;
next = grub_be_to_cpu32 (file.next);
}
}
grub_free (hashtable);
return 0;
fail:
grub_free (node);
grub_free (hashtable);
return 0;
}
/* Open a file named NAME and initialize FILE. */
static grub_err_t
grub_affs_open (struct grub_file *file, const char *name)
{
struct grub_affs_data *data;
struct grub_fshelp_node *fdiro = 0;
grub_dl_ref (my_mod);
data = grub_affs_mount (file->device->disk);
if (!data)
goto fail;
grub_fshelp_find_file (name, &data->diropen, &fdiro, grub_affs_iterate_dir,
grub_affs_read_symlink, GRUB_FSHELP_REG);
if (grub_errno)
goto fail;
file->size = grub_be_to_cpu32 (fdiro->di.size);
data->diropen = *fdiro;
grub_free (fdiro);
file->data = data;
file->offset = 0;
return 0;
fail:
if (data && fdiro != &data->diropen)
grub_free (fdiro);
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_err_t
grub_affs_close (grub_file_t file)
{
struct grub_affs_data *data =
(struct grub_affs_data *) file->data;
grub_free (data->diropen.block_cache);
grub_free (file->data);
grub_dl_unref (my_mod);
return GRUB_ERR_NONE;
}
/* Read LEN bytes data from FILE into BUF. */
static grub_ssize_t
grub_affs_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_affs_data *data =
(struct grub_affs_data *) file->data;
return grub_fshelp_read_file (data->diropen.data->disk, &data->diropen,
file->read_hook, file->read_hook_data,
file->offset, len, buf, grub_affs_read_block,
grub_be_to_cpu32 (data->diropen.di.size),
data->log_blocksize, 0);
}
static grub_int32_t
aftime2ctime (const struct grub_affs_time *t)
{
return grub_be_to_cpu32 (t->day) * 86400
+ grub_be_to_cpu32 (t->min) * 60
+ grub_be_to_cpu32 (t->hz) / 50
+ 8 * 365 * 86400 + 86400 * 2;
}
/* Context for grub_affs_dir. */
struct grub_affs_dir_ctx
{
grub_fs_dir_hook_t hook;
void *hook_data;
};
/* Helper for grub_affs_dir. */
static int
grub_affs_dir_iter (const char *filename, enum grub_fshelp_filetype filetype,
grub_fshelp_node_t node, void *data)
{
struct grub_affs_dir_ctx *ctx = data;
struct grub_dirhook_info info;
grub_memset (&info, 0, sizeof (info));
info.dir = ((filetype & GRUB_FSHELP_TYPE_MASK) == GRUB_FSHELP_DIR);
info.mtimeset = 1;
info.mtime = aftime2ctime (&node->di.mtime);
grub_free (node);
return ctx->hook (filename, &info, ctx->hook_data);
}
static grub_err_t
grub_affs_dir (grub_device_t device, const char *path,
grub_fs_dir_hook_t hook, void *hook_data)
{
struct grub_affs_dir_ctx ctx = { hook, hook_data };
struct grub_affs_data *data = 0;
struct grub_fshelp_node *fdiro = 0;
grub_dl_ref (my_mod);
data = grub_affs_mount (device->disk);
if (!data)
goto fail;
grub_fshelp_find_file (path, &data->diropen, &fdiro, grub_affs_iterate_dir,
grub_affs_read_symlink, GRUB_FSHELP_DIR);
if (grub_errno)
goto fail;
grub_affs_iterate_dir (fdiro, grub_affs_dir_iter, &ctx);
fail:
if (data && fdiro != &data->diropen)
grub_free (fdiro);
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_err_t
grub_affs_label (grub_device_t device, char **label)
{
struct grub_affs_data *data;
struct grub_affs_file file;
grub_disk_t disk = device->disk;
grub_dl_ref (my_mod);
data = grub_affs_mount (disk);
if (data)
{
grub_size_t len;
/* The rootblock maps quite well on a file header block, it's
something we can use here. */
grub_disk_read (data->disk,
(((grub_uint64_t)
grub_be_to_cpu32 (data->bblock.rootblock) + 1)
<< data->log_blocksize) - 1,
GRUB_DISK_SECTOR_SIZE - GRUB_AFFS_FILE_LOCATION,
sizeof (file), &file);
if (grub_errno)
return grub_errno;
len = file.namelen;
if (len > sizeof (file.name))
len = sizeof (file.name);
*label = grub_malloc (len * GRUB_MAX_UTF8_PER_LATIN1 + 1);
if (*label)
*grub_latin1_to_utf8 ((grub_uint8_t *) *label, file.name, len) = '\0';
}
else
*label = 0;
grub_dl_unref (my_mod);
grub_free (data);
return grub_errno;
}
static grub_err_t
grub_affs_mtime (grub_device_t device, grub_int32_t *t)
{
struct grub_affs_data *data;
grub_disk_t disk = device->disk;
struct grub_affs_time af_time;
*t = 0;
grub_dl_ref (my_mod);
data = grub_affs_mount (disk);
if (!data)
{
grub_dl_unref (my_mod);
return grub_errno;
}
grub_disk_read (data->disk,
(((grub_uint64_t)
grub_be_to_cpu32 (data->bblock.rootblock) + 1)
<< data->log_blocksize) - 1,
GRUB_DISK_SECTOR_SIZE - 40,
sizeof (af_time), &af_time);
if (grub_errno)
{
grub_dl_unref (my_mod);
grub_free (data);
return grub_errno;
}
*t = aftime2ctime (&af_time);
grub_dl_unref (my_mod);
grub_free (data);
return GRUB_ERR_NONE;
}
static struct grub_fs grub_affs_fs =
{
.name = "affs",
.dir = grub_affs_dir,
.open = grub_affs_open,
.read = grub_affs_read,
.close = grub_affs_close,
.label = grub_affs_label,
.mtime = grub_affs_mtime,
#ifdef GRUB_UTIL
.reserved_first_sector = 0,
.blocklist_install = 1,
#endif
.next = 0
};
GRUB_MOD_INIT(affs)
{
grub_fs_register (&grub_affs_fs);
my_mod = mod;
}
GRUB_MOD_FINI(affs)
{
grub_fs_unregister (&grub_affs_fs);
}