grub/grub-core/fs/sfs.c
Colin Watson fc524edf65 Remove nested functions from filesystem directory iterators.
* include/grub/fs.h (grub_fs_dir_hook_t): New type.
(struct grub_fs.dir): Add hook_data argument.

Update all implementations and callers.
2013-01-21 01:33:46 +00:00

759 lines
18 KiB
C
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/* sfs.c - Amiga Smart 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 common header for a block. */
struct grub_sfs_bheader
{
grub_uint8_t magic[4];
grub_uint32_t chksum;
grub_uint32_t ipointtomyself;
} __attribute__ ((packed));
/* The sfs rootblock. */
struct grub_sfs_rblock
{
struct grub_sfs_bheader header;
grub_uint32_t version;
grub_uint32_t createtime;
grub_uint8_t flags;
grub_uint8_t unused1[31];
grub_uint32_t blocksize;
grub_uint8_t unused2[40];
grub_uint8_t unused3[8];
grub_uint32_t rootobject;
grub_uint32_t btree;
} __attribute__ ((packed));
enum
{
FLAGS_CASE_SENSITIVE = 0x80
};
/* A SFS object container. */
struct grub_sfs_obj
{
grub_uint8_t unused1[4];
grub_uint32_t nodeid;
grub_uint8_t unused2[4];
union
{
struct
{
grub_uint32_t first_block;
grub_uint32_t size;
} file __attribute__ ((packed));
struct
{
grub_uint32_t hashtable;
grub_uint32_t dir_objc;
} dir __attribute__ ((packed));
} file_dir;
grub_uint32_t mtime;
grub_uint8_t type;
grub_uint8_t filename[1];
grub_uint8_t comment[1];
} __attribute__ ((packed));
#define GRUB_SFS_TYPE_DELETED 32
#define GRUB_SFS_TYPE_SYMLINK 64
#define GRUB_SFS_TYPE_DIR 128
/* A SFS object container. */
struct grub_sfs_objc
{
struct grub_sfs_bheader header;
grub_uint32_t parent;
grub_uint32_t next;
grub_uint32_t prev;
/* The amount of objects depends on the blocksize. */
struct grub_sfs_obj objects[1];
} __attribute__ ((packed));
struct grub_sfs_btree_node
{
grub_uint32_t key;
grub_uint32_t data;
} __attribute__ ((packed));
struct grub_sfs_btree_extent
{
grub_uint32_t key;
grub_uint32_t next;
grub_uint32_t prev;
grub_uint16_t size;
} __attribute__ ((packed));
struct grub_sfs_btree
{
struct grub_sfs_bheader header;
grub_uint16_t nodes;
grub_uint8_t leaf;
grub_uint8_t nodesize;
/* Normally this can be kind of node, but just extents are
supported. */
struct grub_sfs_btree_node node[1];
} __attribute__ ((packed));
struct cache_entry
{
grub_uint32_t off;
grub_uint32_t block;
};
struct grub_fshelp_node
{
struct grub_sfs_data *data;
grub_uint32_t block;
grub_uint32_t size;
grub_uint32_t mtime;
grub_uint32_t cache_off;
grub_uint32_t next_extent;
grub_size_t cache_allocated;
grub_size_t cache_size;
struct cache_entry *cache;
};
/* Information about a "mounted" sfs filesystem. */
struct grub_sfs_data
{
struct grub_sfs_rblock rblock;
struct grub_fshelp_node diropen;
grub_disk_t disk;
/* Log of blocksize in sectors. */
int log_blocksize;
int fshelp_flags;
/* Label of the filesystem. */
char *label;
};
static grub_dl_t my_mod;
/* Lookup the extent starting with BLOCK in the filesystem described
by DATA. Return the extent size in SIZE and the following extent
in NEXTEXT. */
static grub_err_t
grub_sfs_read_extent (struct grub_sfs_data *data, unsigned int block,
grub_uint32_t *size, grub_uint32_t *nextext)
{
char *treeblock;
struct grub_sfs_btree *tree;
int i;
grub_uint32_t next;
treeblock = grub_malloc (GRUB_DISK_SECTOR_SIZE << data->log_blocksize);
if (!block)
return 0;
next = grub_be_to_cpu32 (data->rblock.btree);
tree = (struct grub_sfs_btree *) treeblock;
/* Handle this level in the btree. */
do
{
grub_disk_read (data->disk,
((grub_disk_addr_t) next) << data->log_blocksize,
0, GRUB_DISK_SECTOR_SIZE << data->log_blocksize,
treeblock);
if (grub_errno)
{
grub_free (treeblock);
return grub_errno;
}
for (i = grub_be_to_cpu16 (tree->nodes) - 1; i >= 0; i--)
{
#define EXTNODE(tree, index) \
((struct grub_sfs_btree_node *) (((char *) &(tree)->node[0]) \
+ (index) * (tree)->nodesize))
/* Follow the tree down to the leaf level. */
if ((grub_be_to_cpu32 (EXTNODE(tree, i)->key) <= block)
&& !tree->leaf)
{
next = grub_be_to_cpu32 (EXTNODE (tree, i)->data);
break;
}
/* If the leaf level is reached, just find the correct extent. */
if (grub_be_to_cpu32 (EXTNODE (tree, i)->key) == block && tree->leaf)
{
struct grub_sfs_btree_extent *extent;
extent = (struct grub_sfs_btree_extent *) EXTNODE (tree, i);
/* We found a correct leaf. */
*size = grub_be_to_cpu16 (extent->size);
*nextext = grub_be_to_cpu32 (extent->next);
grub_free (treeblock);
return 0;
}
#undef EXTNODE
}
} while (!tree->leaf);
grub_free (treeblock);
return grub_error (GRUB_ERR_FILE_READ_ERROR, "SFS extent not found");
}
static grub_disk_addr_t
grub_sfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
{
grub_uint32_t blk;
grub_uint32_t size = 0;
grub_uint32_t next = 0;
grub_disk_addr_t off;
struct grub_sfs_data *data = node->data;
/* In case of the first block we don't have to lookup the
extent, the minimum size is always 1. */
if (fileblock == 0)
return node->block;
if (!node->cache)
{
grub_size_t cache_size;
/* Assume half-max extents (32768 sectors). */
cache_size = ((node->size >> (data->log_blocksize + GRUB_DISK_SECTOR_BITS
+ 15))
+ 3);
if (cache_size < 8)
cache_size = 8;
node->cache_off = 0;
node->next_extent = node->block;
node->cache_size = 0;
node->cache = grub_malloc (sizeof (node->cache[0]) * cache_size);
if (!node->cache)
{
grub_errno = 0;
node->cache_allocated = 0;
}
else
{
node->cache_allocated = cache_size;
node->cache[0].off = 0;
node->cache[0].block = node->block;
}
}
if (fileblock < node->cache_off)
{
unsigned int i = 0;
int j, lg;
for (lg = 0; node->cache_size >> lg; lg++);
for (j = lg - 1; j >= 0; j--)
if ((i | (1 << j)) < node->cache_size
&& node->cache[(i | (1 << j))].off <= fileblock)
i |= (1 << j);
return node->cache[i].block + fileblock - node->cache[i].off;
}
off = node->cache_off;
blk = node->next_extent;
while (blk)
{
grub_err_t err;
err = grub_sfs_read_extent (node->data, blk, &size, &next);
if (err)
return 0;
if (node->cache && node->cache_size >= node->cache_allocated)
{
struct cache_entry *e = node->cache;
e = grub_realloc (node->cache,node->cache_allocated * 2
* sizeof (e[0]));
if (!e)
{
grub_errno = 0;
grub_free (node->cache);
node->cache = 0;
}
else
{
node->cache_allocated *= 2;
node->cache = e;
}
}
if (node->cache)
{
node->cache_off = off + size;
node->next_extent = next;
node->cache[node->cache_size].off = off;
node->cache[node->cache_size].block = blk;
node->cache_size++;
}
if (fileblock - off < size)
return fileblock - off + blk;
off += size;
blk = next;
}
grub_error (GRUB_ERR_FILE_READ_ERROR,
"reading a SFS block outside the extent");
return 0;
}
/* Read LEN bytes from the file described by DATA starting with byte
POS. Return the amount of read bytes in READ. */
static grub_ssize_t
grub_sfs_read_file (grub_fshelp_node_t node,
void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
unsigned offset, unsigned length),
grub_off_t pos, grub_size_t len, char *buf)
{
return grub_fshelp_read_file (node->data->disk, node, read_hook,
pos, len, buf, grub_sfs_read_block,
node->size, node->data->log_blocksize, 0);
}
static struct grub_sfs_data *
grub_sfs_mount (grub_disk_t disk)
{
struct grub_sfs_data *data;
struct grub_sfs_objc *rootobjc;
char *rootobjc_data = 0;
grub_uint32_t blk;
data = grub_malloc (sizeof (*data));
if (!data)
return 0;
/* Read the rootblock. */
grub_disk_read (disk, 0, 0, sizeof (struct grub_sfs_rblock),
&data->rblock);
if (grub_errno)
goto fail;
/* Make sure this is a sfs filesystem. */
if (grub_strncmp ((char *) (data->rblock.header.magic), "SFS", 4)
|| data->rblock.blocksize == 0
|| (data->rblock.blocksize & (data->rblock.blocksize - 1)) != 0
|| (data->rblock.blocksize & grub_cpu_to_be32_compile_time (0xf00001ff)))
{
grub_error (GRUB_ERR_BAD_FS, "not a SFS filesystem");
goto fail;
}
for (data->log_blocksize = 9;
(1U << data->log_blocksize) < grub_be_to_cpu32 (data->rblock.blocksize);
data->log_blocksize++);
data->log_blocksize -= GRUB_DISK_SECTOR_BITS;
if (data->rblock.flags & FLAGS_CASE_SENSITIVE)
data->fshelp_flags = 0;
else
data->fshelp_flags = GRUB_FSHELP_CASE_INSENSITIVE;
rootobjc_data = grub_malloc (GRUB_DISK_SECTOR_SIZE << data->log_blocksize);
if (! rootobjc_data)
goto fail;
/* Read the root object container. */
grub_disk_read (disk, ((grub_disk_addr_t) grub_be_to_cpu32 (data->rblock.rootobject))
<< data->log_blocksize, 0,
GRUB_DISK_SECTOR_SIZE << data->log_blocksize, rootobjc_data);
if (grub_errno)
goto fail;
rootobjc = (struct grub_sfs_objc *) rootobjc_data;
blk = grub_be_to_cpu32 (rootobjc->objects[0].file_dir.dir.dir_objc);
data->diropen.size = 0;
data->diropen.block = blk;
data->diropen.data = data;
data->diropen.cache = 0;
data->disk = disk;
data->label = grub_strdup ((char *) (rootobjc->objects[0].filename));
grub_free (rootobjc_data);
return data;
fail:
if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
grub_error (GRUB_ERR_BAD_FS, "not an SFS filesystem");
grub_free (data);
grub_free (rootobjc_data);
return 0;
}
static char *
grub_sfs_read_symlink (grub_fshelp_node_t node)
{
struct grub_sfs_data *data = node->data;
char *symlink;
char *block;
block = grub_malloc (GRUB_DISK_SECTOR_SIZE << data->log_blocksize);
if (!block)
return 0;
grub_disk_read (data->disk, ((grub_disk_addr_t) node->block)
<< data->log_blocksize,
0, GRUB_DISK_SECTOR_SIZE << data->log_blocksize, block);
if (grub_errno)
{
grub_free (block);
return 0;
}
/* This is just a wild guess, but it always worked for me. How the
SLNK block looks like is not documented in the SFS docs. */
symlink = grub_malloc (((GRUB_DISK_SECTOR_SIZE << data->log_blocksize)
- 24) * GRUB_MAX_UTF8_PER_LATIN1 + 1);
if (!symlink)
{
grub_free (block);
return 0;
}
*grub_latin1_to_utf8 ((grub_uint8_t *) symlink, (grub_uint8_t *) &block[24],
(GRUB_DISK_SECTOR_SIZE << data->log_blocksize) - 24) = '\0';
grub_free (block);
return symlink;
}
/* Helper for grub_sfs_iterate_dir. */
static int
grub_sfs_create_node (struct grub_fshelp_node **node,
struct grub_sfs_data *data,
const char *name,
grub_uint32_t block, grub_uint32_t size, int type,
grub_uint32_t mtime,
grub_fshelp_iterate_dir_hook_t hook, void *hook_data)
{
grub_size_t len = grub_strlen (name);
grub_uint8_t *name_u8;
int ret;
*node = grub_malloc (sizeof (**node));
if (!*node)
return 1;
name_u8 = grub_malloc (len * GRUB_MAX_UTF8_PER_LATIN1 + 1);
if (!name_u8)
{
grub_free (*node);
return 1;
}
(*node)->data = data;
(*node)->size = size;
(*node)->block = block;
(*node)->mtime = mtime;
(*node)->cache = 0;
(*node)->cache_off = 0;
(*node)->next_extent = block;
(*node)->cache_size = 0;
(*node)->cache_allocated = 0;
*grub_latin1_to_utf8 (name_u8, (const grub_uint8_t *) name, len) = '\0';
ret = hook ((char *) name_u8, type | data->fshelp_flags, *node, hook_data);
grub_free (name_u8);
return ret;
}
static int
grub_sfs_iterate_dir (grub_fshelp_node_t dir,
grub_fshelp_iterate_dir_hook_t hook, void *hook_data)
{
struct grub_fshelp_node *node = 0;
struct grub_sfs_data *data = dir->data;
char *objc_data;
struct grub_sfs_objc *objc;
unsigned int next = dir->block;
grub_uint32_t pos;
objc_data = grub_malloc (GRUB_DISK_SECTOR_SIZE << data->log_blocksize);
if (!objc_data)
goto fail;
/* The Object container can consist of multiple blocks, iterate over
every block. */
while (next)
{
grub_disk_read (data->disk, ((grub_disk_addr_t) next)
<< data->log_blocksize, 0,
GRUB_DISK_SECTOR_SIZE << data->log_blocksize, objc_data);
if (grub_errno)
goto fail;
objc = (struct grub_sfs_objc *) objc_data;
pos = (char *) &objc->objects[0] - (char *) objc;
/* Iterate over all entries in this block. */
while (pos + sizeof (struct grub_sfs_obj)
< (1U << (GRUB_DISK_SECTOR_BITS + data->log_blocksize)))
{
struct grub_sfs_obj *obj;
obj = (struct grub_sfs_obj *) ((char *) objc + pos);
const char *filename = (const char *) obj->filename;
grub_size_t len;
enum grub_fshelp_filetype type;
grub_uint32_t block;
/* The filename and comment dynamically increase the size of
the object. */
len = grub_strlen (filename);
len += grub_strlen (filename + len + 1);
pos += sizeof (*obj) + len;
/* Round up to a multiple of two bytes. */
pos = ((pos + 1) >> 1) << 1;
if (filename[0] == 0)
continue;
/* First check if the file was not deleted. */
if (obj->type & GRUB_SFS_TYPE_DELETED)
continue;
else if (obj->type & GRUB_SFS_TYPE_SYMLINK)
type = GRUB_FSHELP_SYMLINK;
else if (obj->type & GRUB_SFS_TYPE_DIR)
type = GRUB_FSHELP_DIR;
else
type = GRUB_FSHELP_REG;
if (type == GRUB_FSHELP_DIR)
block = grub_be_to_cpu32 (obj->file_dir.dir.dir_objc);
else
block = grub_be_to_cpu32 (obj->file_dir.file.first_block);
if (grub_sfs_create_node (&node, data, filename, block,
grub_be_to_cpu32 (obj->file_dir.file.size),
type, grub_be_to_cpu32 (obj->mtime),
hook, hook_data))
{
grub_free (objc_data);
return 1;
}
}
next = grub_be_to_cpu32 (objc->next);
}
fail:
grub_free (objc_data);
return 0;
}
/* Open a file named NAME and initialize FILE. */
static grub_err_t
grub_sfs_open (struct grub_file *file, const char *name)
{
struct grub_sfs_data *data;
struct grub_fshelp_node *fdiro = 0;
grub_dl_ref (my_mod);
data = grub_sfs_mount (file->device->disk);
if (!data)
goto fail;
grub_fshelp_find_file (name, &data->diropen, &fdiro, grub_sfs_iterate_dir,
grub_sfs_read_symlink, GRUB_FSHELP_REG);
if (grub_errno)
goto fail;
file->size = fdiro->size;
data->diropen = *fdiro;
grub_free (fdiro);
file->data = data;
file->offset = 0;
return 0;
fail:
if (data && fdiro != &data->diropen)
grub_free (fdiro);
if (data)
grub_free (data->label);
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_err_t
grub_sfs_close (grub_file_t file)
{
struct grub_sfs_data *data = (struct grub_sfs_data *) file->data;
grub_free (data->diropen.cache);
grub_free (data->label);
grub_free (data);
grub_dl_unref (my_mod);
return GRUB_ERR_NONE;
}
/* Read LEN bytes data from FILE into BUF. */
static grub_ssize_t
grub_sfs_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_sfs_data *data = (struct grub_sfs_data *) file->data;
return grub_sfs_read_file (&data->diropen, file->read_hook,
file->offset, len, buf);
}
/* Context for grub_sfs_dir. */
struct grub_sfs_dir_ctx
{
grub_fs_dir_hook_t hook;
void *hook_data;
};
/* Helper for grub_sfs_dir. */
static int
grub_sfs_dir_iter (const char *filename, enum grub_fshelp_filetype filetype,
grub_fshelp_node_t node, void *data)
{
struct grub_sfs_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.mtime = node->mtime + 8 * 365 * 86400 + 86400 * 2;
info.mtimeset = 1;
grub_free (node->cache);
grub_free (node);
return ctx->hook (filename, &info, ctx->hook_data);
}
static grub_err_t
grub_sfs_dir (grub_device_t device, const char *path,
grub_fs_dir_hook_t hook, void *hook_data)
{
struct grub_sfs_dir_ctx ctx = { hook, hook_data };
struct grub_sfs_data *data = 0;
struct grub_fshelp_node *fdiro = 0;
grub_dl_ref (my_mod);
data = grub_sfs_mount (device->disk);
if (!data)
goto fail;
grub_fshelp_find_file (path, &data->diropen, &fdiro, grub_sfs_iterate_dir,
grub_sfs_read_symlink, GRUB_FSHELP_DIR);
if (grub_errno)
goto fail;
grub_sfs_iterate_dir (fdiro, grub_sfs_dir_iter, &ctx);
fail:
if (data && fdiro != &data->diropen)
grub_free (fdiro);
if (data)
grub_free (data->label);
grub_free (data);
grub_dl_unref (my_mod);
return grub_errno;
}
static grub_err_t
grub_sfs_label (grub_device_t device, char **label)
{
struct grub_sfs_data *data;
grub_disk_t disk = device->disk;
data = grub_sfs_mount (disk);
if (data)
{
grub_size_t len = grub_strlen (data->label);
*label = grub_malloc (len * GRUB_MAX_UTF8_PER_LATIN1 + 1);
if (*label)
*grub_latin1_to_utf8 ((grub_uint8_t *) *label,
(const grub_uint8_t *) data->label,
len) = '\0';
grub_free (data->label);
}
grub_free (data);
return grub_errno;
}
static struct grub_fs grub_sfs_fs =
{
.name = "sfs",
.dir = grub_sfs_dir,
.open = grub_sfs_open,
.read = grub_sfs_read,
.close = grub_sfs_close,
.label = grub_sfs_label,
#ifdef GRUB_UTIL
.reserved_first_sector = 0,
.blocklist_install = 1,
#endif
.next = 0
};
GRUB_MOD_INIT(sfs)
{
grub_fs_register (&grub_sfs_fs);
my_mod = mod;
}
GRUB_MOD_FINI(sfs)
{
grub_fs_unregister (&grub_sfs_fs);
}