grub/fs/hfs.c

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/* hfs.c - HFS. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2004 Free Software Foundation, Inc.
*
* 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#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>
#define GRUB_HFS_SBLOCK 2
#define GRUB_HFS_MAGIC 0x4244
#define GRUB_HFS_BLKS (data->blksz >> 9)
#define GRUB_HFS_NODE_LEAF 0xFF
/* The two supported filesystems a record can have. */
enum
{
GRUB_HFS_FILETYPE_DIR = 1,
GRUB_HFS_FILETYPE_FILE = 2
};
/* A single extent. A file consists of suchs extents. */
struct grub_hfs_extent
{
/* The first physical block. */
grub_uint16_t first_block;
grub_uint16_t count;
};
/* HFS stores extents in groups of 3. */
typedef struct grub_hfs_extent grub_hfs_datarecord_t[3];
/* The HFS superblock (The official name is `Master Directory
Block'). */
struct grub_hfs_sblock
{
grub_uint16_t magic;
grub_uint8_t unused[18];
grub_uint32_t blksz;
grub_uint8_t unused2[4];
grub_uint16_t first_block;
grub_uint8_t unused4[6];
/* A pascal style string that holds the volumename. */
grub_uint8_t volname[28];
grub_uint8_t unused5[70];
grub_hfs_datarecord_t extent_recs;
grub_uint32_t catalog_size;
grub_hfs_datarecord_t catalog_recs;
} __attribute__ ((packed));
/* A node desciptor. This is the header of every node. */
struct grub_hfs_node
{
grub_uint32_t next;
grub_uint32_t prev;
grub_uint8_t type;
grub_uint8_t level;
grub_uint16_t reccnt;
grub_uint16_t unused;
} __attribute__ ((packed));
/* The head of the B*-Tree. */
struct grub_hfs_treeheader
{
grub_uint16_t tree_depth;
/* The number of the first node. */
grub_uint32_t root_node;
grub_uint32_t leaves;
grub_uint32_t first_leaf;
grub_uint32_t last_leaf;
grub_uint16_t node_size;
grub_uint16_t key_size;
grub_uint32_t nodes;
grub_uint32_t free_nodes;
grub_uint8_t unused[76];
} __attribute__ ((packed));
/* The state of a mounted HFS filesystem. */
struct grub_hfs_data
{
struct grub_hfs_sblock sblock;
grub_disk_t disk;
grub_hfs_datarecord_t extents;
int fileid;
int size;
int ext_root;
int ext_size;
int cat_root;
int cat_size;
int blksz;
int log2_blksz;
int rootdir;
};
/* The key as used on disk in a catalog tree. This is used to lookup
file/directory nodes by parent directory ID and filename. */
struct grub_hfs_catalog_key
{
grub_uint8_t unused;
grub_uint32_t parent_dir;
/* Filename length. */
grub_uint8_t strlen;
/* Filename. */
grub_uint8_t str[31];
} __attribute__ ((packed));
/* The key as used on disk in a extent overflow tree. Using this key
the extents can be looked up using a fileid and logical start block
as index. */
struct grub_hfs_extent_key
{
/* The kind of fork. This is used to store meta information like
icons, attributes, etc. We will only use the datafork, which is
0. */
grub_uint8_t forktype;
grub_uint32_t fileid;
grub_uint16_t first_block;
} __attribute__ ((packed));
/* A dirrect record. This is used to find out the directory ID. */
struct grub_hfs_dirrec
{
/* For a directory, type == 1. */
grub_uint8_t type;
grub_uint8_t unused[5];
grub_uint32_t dirid;
} __attribute__ ((packed));
/* Information about a file. */
struct grub_hfs_filerec
{
/* For a file, type == 2. */
grub_uint8_t type;
grub_uint8_t unused[19];
grub_uint32_t fileid;
grub_uint8_t unused2[2];
grub_uint32_t size;
grub_uint8_t unused3[44];
/* The first 3 extents of the file. The other extents can be found
in the extent overflow file. */
grub_hfs_datarecord_t extents;
} __attribute__ ((packed));
/* A record descriptor, both key and data, used to pass to call back
functions. */
struct grub_hfs_record
{
void *key;
int keylen;
void *data;
int datalen;
};
#ifndef GRUB_UTIL
static grub_dl_t my_mod;
#endif
static int grub_hfs_find_node (struct grub_hfs_data *, char *,
grub_uint32_t, int, char *, int);
/* Find block BLOCK of the file FILE in the mounted UFS filesystem
DATA. The first 3 extents are described by DAT. If cache is set,
using caching to improve non-random reads. */
static unsigned int
grub_hfs_block (struct grub_hfs_data *data, grub_hfs_datarecord_t dat,
int file, int block, int cache)
{
grub_hfs_datarecord_t dr;
int pos = 0;
struct grub_hfs_extent_key key;
int tree = 0;
static int cache_file = 0;
static int cache_pos = 0;
static grub_hfs_datarecord_t cache_dr;
grub_memcpy (dr, dat, sizeof (dr));
key.forktype = 0;
key.fileid = grub_cpu_to_be32 (file);
if (cache && cache_file == file && block > cache_pos)
{
pos = cache_pos;
key.first_block = grub_cpu_to_be16 (pos);
grub_memcpy (dr, cache_dr, sizeof (cache_dr));
}
for (;;)
{
int i;
/* Try all 3 extents. */
for (i = 0; i < 3; i++)
{
/* Check if the block is stored in this extent. */
if (grub_be_to_cpu16 (dr[i].count) + pos > block)
{
int first = grub_be_to_cpu16 (dr[i].first_block);
/* If the cache is enabled, store the current position
in the tree. */
if (tree && cache)
{
cache_file = file;
cache_pos = pos;
grub_memcpy (cache_dr, dr, sizeof (cache_dr));
}
return (grub_be_to_cpu16 (data->sblock.first_block)
+ (first + block - pos) * GRUB_HFS_BLKS);
}
/* Try the next extent. */
pos += grub_be_to_cpu16 (dr[i].count);
}
/* Lookup the block in the extent overflow file. */
key.first_block = grub_cpu_to_be16 (pos);
tree = 1;
grub_hfs_find_node (data, (char *) &key, data->ext_root,
1, (char *) &dr, sizeof (dr));
if (grub_errno)
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_hfs_read_file (struct grub_hfs_data *data,
void (*read_hook) (unsigned long sector,
unsigned offset, unsigned length),
int pos, unsigned int len, char *buf)
{
int i;
int blockcnt;
/* Adjust len so it we can't read past the end of the file. */
if (len > grub_le_to_cpu32 (data->size))
len = grub_le_to_cpu32 (data->size);
blockcnt = ((len + pos)
+ data->blksz - 1) / data->blksz;
for (i = pos / data->blksz; i < blockcnt; i++)
{
int blknr;
int blockoff = pos % data->blksz;
int blockend = data->blksz;
int skipfirst = 0;
blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1);
if (grub_errno)
return -1;
/* Last block. */
if (i == blockcnt - 1)
{
blockend = (len + pos) % data->blksz;
/* The last portion is exactly EXT2_BLOCK_SIZE (data). */
if (!blockend)
blockend = data->blksz;
}
/* First block. */
if (i == pos / data->blksz)
{
skipfirst = blockoff;
blockend -= skipfirst;
}
/* If the block number is 0 this block is not stored on disk but
is zero filled instead. */
if (blknr)
{
data->disk->read_hook = read_hook;
grub_disk_read (data->disk, blknr, skipfirst,
blockend, buf);
data->disk->read_hook = 0;
if (grub_errno)
return -1;
}
buf += data->blksz - skipfirst;
}
return len;
}
/* Mount the filesystem on the disk DISK. */
static struct grub_hfs_data *
grub_hfs_mount (grub_disk_t disk)
{
struct grub_hfs_data *data;
struct grub_hfs_catalog_key key;
struct grub_hfs_dirrec dir;
int first_block;
struct
{
struct grub_hfs_node node;
struct grub_hfs_treeheader head;
} treehead;
data = grub_malloc (sizeof (struct grub_hfs_data));
if (!data)
return 0;
/* Read the superblock. */
if (grub_disk_read (disk, GRUB_HFS_SBLOCK, 0,
sizeof (struct grub_hfs_sblock), (char *) &data->sblock))
goto fail;
/* Check if this is a HFS filesystem. */
if (grub_be_to_cpu16 (data->sblock.magic) != GRUB_HFS_MAGIC)
{
grub_error (GRUB_ERR_BAD_FS, "not a hfs filesystem");
goto fail;
}
data->blksz = grub_be_to_cpu32 (data->sblock.blksz);
data->disk = disk;
/* Lookup the root node of the extent overflow tree. */
first_block = ((grub_be_to_cpu16 (data->sblock.extent_recs[0].first_block)
* GRUB_HFS_BLKS)
+ grub_be_to_cpu16 (data->sblock.first_block));
if (grub_disk_read (data->disk, first_block, 0,
sizeof (treehead), (char *) &treehead))
goto fail;
data->ext_root = grub_be_to_cpu32 (treehead.head.root_node);
data->ext_size = grub_be_to_cpu16 (treehead.head.node_size);
/* Lookup the root node of the catalog tree. */
first_block = ((grub_be_to_cpu16 (data->sblock.catalog_recs[0].first_block)
* GRUB_HFS_BLKS)
+ grub_be_to_cpu16 (data->sblock.first_block));
if (grub_disk_read (data->disk, first_block, 0,
sizeof (treehead), (char *) &treehead))
goto fail;
data->cat_root = grub_be_to_cpu32 (treehead.head.root_node);
data->cat_size = grub_be_to_cpu16 (treehead.head.node_size);
/* Lookup the root directory node in the catalog tree using the
volume name. */
key.parent_dir = grub_cpu_to_be32 (1);
key.strlen = data->sblock.volname[0];
grub_strcpy (key.str, data->sblock.volname + 1);
if (grub_hfs_find_node (data, (char *) &key, data->cat_root,
0, (char *) &dir, sizeof (dir)) == 0)
{
grub_error (GRUB_ERR_BAD_FS, "can not find the hfs root directory");
goto fail;
}
if (grub_errno)
goto fail;
data->rootdir = grub_be_to_cpu32 (dir.dirid);
return data;
fail:
grub_free (data);
if (grub_errno == GRUB_ERR_OUT_OF_RANGE)
grub_error (GRUB_ERR_BAD_FS, "not a hfs filesystem");
return 0;
}
/* Compare the K1 and K2 catalog file keys. */
static int
grub_hfs_cmp_catkeys (struct grub_hfs_catalog_key *k1,
struct grub_hfs_catalog_key *k2)
{
int cmp = (grub_be_to_cpu32 (k1->parent_dir)
- grub_be_to_cpu32 (k2->parent_dir));
if (cmp != 0)
return cmp;
cmp = grub_strncasecmp (k1->str, k2->str, k1->strlen);
/* This is required because the compared strings are not of equal
length. */
if (cmp == 0 && k1->strlen < k2->strlen)
return -1;
return cmp;
}
/* Compare the K1 and K2 extent overflow file keys. */
static int
grub_hfs_cmp_extkeys (struct grub_hfs_extent_key *k1,
struct grub_hfs_extent_key *k2)
{
int cmp = k1->forktype - k2->forktype;
if (cmp == 0)
cmp = grub_be_to_cpu32 (k1->fileid) - grub_be_to_cpu32 (k2->fileid);
if (cmp == 0)
cmp = (grub_be_to_cpu16 (k1->first_block)
- grub_be_to_cpu16 (k2->first_block));
return cmp;
}
/* Iterate the records in the node with index IDX in the mounted HFS
filesystem DATA. This node holds data of the type TYPE (0 =
catalog node, 1 = extent overflow node). If this is set, continue
iterating to the next node. For every records, call NODE_HOOK. */
static grub_err_t
grub_hfs_iterate_records (struct grub_hfs_data *data, int type, int idx,
int this, int (*node_hook) (struct grub_hfs_node *hnd,
struct grub_hfs_record *))
{
int nodesize = type == 0 ? data->cat_size : data->ext_size;
union
{
struct grub_hfs_node node;
char rawnode[nodesize];
grub_uint16_t offsets[nodesize / 2];
} node;
do
{
int i;
struct grub_hfs_extent *dat;
int blk;
dat = (struct grub_hfs_extent *) (type == 0
? (&data->sblock.catalog_recs)
: (&data->sblock.extent_recs));
/* Read the node into memory. */
blk = grub_hfs_block (data, dat,
0, idx / (data->blksz / nodesize), 0);
blk += (idx % (data->blksz / nodesize));
if (grub_errno)
return grub_errno;
if (grub_disk_read (data->disk, blk, 0,
sizeof (node), (char *) &node))
return grub_errno;
/* Iterate over all records in this node. */
for (i = 0; i < grub_be_to_cpu16 (node.node.reccnt); i++)
{
int pos = (nodesize >> 1) - 1 - i;
struct pointer
{
grub_uint8_t keylen;
grub_uint8_t key;
} __attribute__ ((packed)) *pnt;
pnt = (struct pointer *) (grub_be_to_cpu16 (node.offsets[pos])
+ node.rawnode);
struct grub_hfs_record rec =
{
&pnt->key,
pnt->keylen,
&pnt->key + pnt->keylen +(pnt->keylen + 1) % 2,
nodesize - grub_be_to_cpu16 (node.offsets[pos])
- pnt->keylen - 1
};
if (node_hook (&node.node, &rec))
return 0;
}
if (idx % (data->blksz / nodesize) == 0)
idx = grub_be_to_cpu32 (node.node.next);
else
idx++;
} while (idx && this);
return 0;
}
/* Lookup a record in the mounted filesystem DATA using the key KEY.
The index of the node on top of the tree is IDX. The tree is of
the type TYPE (0 = catalog node, 1 = extent overflow node). Return
the data in DATAR with a maximum length of DATALEN. */
static int
grub_hfs_find_node (struct grub_hfs_data *data, char *key,
grub_uint32_t idx, int type, char *datar, int datalen)
{
int found = -1;
int isleaf = 0;
auto int node_found (struct grub_hfs_node *, struct grub_hfs_record *);
int node_found (struct grub_hfs_node *hnd, struct grub_hfs_record *rec)
{
int cmp = 1;
if (type == 0)
cmp = grub_hfs_cmp_catkeys (rec->key, (void *) key);
else
cmp = grub_hfs_cmp_extkeys (rec->key, (void *) key);
/* If the key is smaller or equal to the currect node, mark the
entry. In case of a non-leaf mode it will be used to lookup
the rest of the tree. */
if (cmp <= 0)
{
grub_uint32_t *node = (grub_uint32_t *) rec->data;
found = grub_be_to_cpu32 (*node);
}
else /* The key can not be found in the tree. */
return 1;
/* Check if this node is a leaf node. */
if (hnd->type == GRUB_HFS_NODE_LEAF)
{
isleaf = 1;
/* Found it!!!! */
if (cmp == 0)
{
grub_memcpy (datar, rec->data,
rec->datalen < datalen ? rec->datalen : datalen);
return 1;
}
}
return 0;
}
if (grub_hfs_iterate_records (data, type, idx, 0, node_found))
return 0;
if (found == -1)
return 0;
if (isleaf)
return 1;
return grub_hfs_find_node (data, key, found, type, datar, datalen);
}
/* Iterate over the directory with the id DIR. The tree is searched
starting with the node ROOT_IDX. For every entry in this directory
call HOOK. */
static grub_err_t
grub_hfs_iterate_dir (struct grub_hfs_data *data, grub_uint32_t root_idx,
unsigned int dir, int (*hook) (struct grub_hfs_record *))
{
int found = -1;
int isleaf = 0;
int next = 0;
/* The lowest key possible with DIR as root directory. */
struct grub_hfs_catalog_key key = {0, grub_cpu_to_be32 (dir), 0, ""};
auto int node_found (struct grub_hfs_node *, struct grub_hfs_record *);
auto int it_dir (struct grub_hfs_node * __attribute ((unused)),
struct grub_hfs_record *);
int node_found (struct grub_hfs_node *hnd, struct grub_hfs_record *rec)
{
struct grub_hfs_catalog_key *ckey = rec->key;
if (grub_hfs_cmp_catkeys (rec->key, (void *) &key) <= 0)
found = grub_be_to_cpu32 (*(grub_uint32_t *) rec->data);
if (hnd->type == 0xFF && ckey->strlen > 0)
{
isleaf = 1;
next = grub_be_to_cpu32 (hnd->next);
/* An entry was found. */
if (grub_be_to_cpu32 (ckey->parent_dir) == dir)
return hook (rec);
}
return 0;
}
int it_dir (struct grub_hfs_node *hnd __attribute ((unused)),
struct grub_hfs_record *rec)
{
struct grub_hfs_catalog_key *ckey = rec->key;
struct grub_hfs_catalog_key *origkey = &key;
/* Stop when the entries do not match anymore. */
if (grub_be_to_cpu32 (ckey->parent_dir)
!= grub_be_to_cpu32 ((origkey)->parent_dir))
return 1;
return hook (rec);
}
if (grub_hfs_iterate_records (data, 0, root_idx, 0, node_found))
return grub_errno;
if (found == -1)
return 0;
/* If there was a matching record in this leaf node, continue the
iteration until the last record was found. */
if (isleaf)
{
grub_hfs_iterate_records (data, 0, next, 1, it_dir);
return grub_errno;
}
return grub_hfs_iterate_dir (data, found, dir, hook);
}
/* Find a file or directory with the pathname PATH in the filesystem
DATA. Return the file record in RETDATA when it is non-zero.
Return the directory number in RETINODE when it is non-zero. */
static grub_err_t
grub_hfs_find_dir (struct grub_hfs_data *data, const char *path,
struct grub_hfs_filerec *retdata, int *retinode)
{
int inode = data->rootdir;
char *next;
char *origpath;
struct grub_hfs_filerec frec;
struct grub_hfs_dirrec *dir = (struct grub_hfs_dirrec *) &frec;
frec.type = GRUB_HFS_FILETYPE_DIR;
if (path[0] != '/')
{
grub_error (GRUB_ERR_BAD_FILENAME, "bad filename");
return 0;
}
origpath = grub_strdup (path);
if (!origpath)
return grub_errno;
path = origpath;
path++;
while (path && grub_strlen (path))
{
if (frec.type != GRUB_HFS_FILETYPE_DIR)
{
grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
goto fail;
}
/* Isolate a part of the path. */
next = grub_strchr (path, '/');
if (next)
{
next[0] = '\0';
next++;
}
struct grub_hfs_catalog_key key;
key.parent_dir = grub_cpu_to_be32 (inode);
key.strlen = grub_strlen (path);
grub_strcpy (key.str, path);
/* Lookup this node. */
if (!grub_hfs_find_node (data, (char *) &key, data->cat_root,
0, (char *) &frec, sizeof (frec)))
{
grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
goto fail;
}
if (grub_errno)
goto fail;
inode = grub_be_to_cpu32 (dir->dirid);
path = next;
}
if (retdata)
grub_memcpy (retdata, &frec, sizeof (frec));
if (retinode)
*retinode = inode;
fail:
grub_free (origpath);
return grub_errno;
}
static grub_err_t
grub_hfs_dir (grub_device_t device, const char *path,
int (*hook) (const char *filename, int dir))
{
int inode;
auto int dir_hook (struct grub_hfs_record *rec);
int dir_hook (struct grub_hfs_record *rec)
{
char fname[32] = { 0 };
char *filetype = rec->data;
struct grub_hfs_catalog_key *ckey = rec->key;
grub_strncpy (fname, ckey->str, ckey->strlen);
if (*filetype == GRUB_HFS_FILETYPE_DIR)
return hook (fname, 1);
else if (*filetype == GRUB_HFS_FILETYPE_FILE)
return hook (fname, 0);
return 0;
}
struct grub_hfs_data *data;
struct grub_hfs_filerec frec;
#ifndef GRUB_UTIL
grub_dl_ref (my_mod);
#endif
data = grub_hfs_mount (device->disk);
if (!data)
goto fail;
/* First the directory ID for the directory. */
if (grub_hfs_find_dir (data, path, &frec, &inode))
goto fail;
if (frec.type != GRUB_HFS_FILETYPE_DIR)
{
grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
goto fail;
}
grub_hfs_iterate_dir (data, data->cat_root, inode, dir_hook);
fail:
grub_free (data);
#ifndef GRUB_UTIL
grub_dl_unref (my_mod);
#endif
return grub_errno;
}
/* Open a file named NAME and initialize FILE. */
static grub_err_t
grub_hfs_open (struct grub_file *file, const char *name)
{
struct grub_hfs_data *data;
struct grub_hfs_filerec frec;
#ifndef GRUB_UTIL
grub_dl_ref (my_mod);
#endif
data = grub_hfs_mount (file->device->disk);
if (grub_hfs_find_dir (data, name, &frec, 0))
{
grub_free (data);
#ifndef GRUB_UTIL
grub_dl_unref (my_mod);
#endif
return grub_errno;
}
if (frec.type != GRUB_HFS_FILETYPE_FILE)
{
grub_free (data);
grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a file");
#ifndef GRUB_UTIL
grub_dl_unref (my_mod);
#endif
return grub_errno;
}
grub_memcpy (data->extents, frec.extents, sizeof (grub_hfs_datarecord_t));
file->size = grub_be_to_cpu32 (frec.size);
data->size = grub_be_to_cpu32 (frec.size);
data->fileid = grub_be_to_cpu32 (frec.fileid);
file->offset = 0;
file->data = data;
return 0;
}
static grub_ssize_t
grub_hfs_read (grub_file_t file, char *buf, grub_ssize_t len)
{
struct grub_hfs_data *data =
(struct grub_hfs_data *) file->data;
return grub_hfs_read_file (data, file->read_hook, file->offset, len, buf);
}
static grub_err_t
grub_hfs_close (grub_file_t file)
{
grub_free (file->data);
#ifndef GRUB_UTIL
grub_dl_unref (my_mod);
#endif
return 0;
}
static grub_err_t
grub_hfs_label (grub_device_t device, char **label)
{
struct grub_hfs_data *data;
data = grub_hfs_mount (device->disk);
if (data)
*label = grub_strndup (data->sblock.volname + 1, *data->sblock.volname);
else
*label = 0;
grub_free (data);
return grub_errno;
}
static struct grub_fs grub_hfs_fs =
{
.name = "hfs",
.dir = grub_hfs_dir,
.open = grub_hfs_open,
.read = grub_hfs_read,
.close = grub_hfs_close,
.label = grub_hfs_label,
.next = 0
};
#ifdef GRUB_UTIL
void
grub_hfs_init (void)
{
grub_fs_register (&grub_hfs_fs);
}
void
grub_hfs_fini (void)
{
grub_fs_unregister (&grub_hfs_fs);
}
#else /* ! GRUB_UTIL */
GRUB_MOD_INIT
{
grub_fs_register (&grub_hfs_fs);
my_mod = mod;
}
GRUB_MOD_FINI
{
grub_fs_unregister (&grub_hfs_fs);
}
#endif /* ! GRUB_UTIL */