/* minix.c - The minix filesystem, version 1 and 2. */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2004,2005,2006,2007,2008 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 .
*/
#include
#include
#include
#include
#include
#include
#include
#include
GRUB_MOD_LICENSE ("GPLv3+");
#ifdef MODE_MINIX3
#define GRUB_MINIX_MAGIC 0x4D5A
#elif defined(MODE_MINIX2)
#define GRUB_MINIX_MAGIC 0x2468
#define GRUB_MINIX_MAGIC_30 0x2478
#else
#define GRUB_MINIX_MAGIC 0x137F
#define GRUB_MINIX_MAGIC_30 0x138F
#endif
#define GRUB_MINIX_INODE_DIR_BLOCKS 7
#define GRUB_MINIX_LOG2_BSIZE 1
#define GRUB_MINIX_ROOT_INODE 1
#define GRUB_MINIX_MAX_SYMLNK_CNT 8
#define GRUB_MINIX_SBLOCK 2
#define GRUB_MINIX_IFDIR 0040000U
#define GRUB_MINIX_IFLNK 0120000U
#ifdef MODE_BIGENDIAN
#define grub_cpu_to_minix16_compile_time grub_cpu_to_be16_compile_time
#define grub_minix_to_cpu16 grub_be_to_cpu16
#define grub_minix_to_cpu32 grub_be_to_cpu32
#else
#define grub_cpu_to_minix16_compile_time grub_cpu_to_le16_compile_time
#define grub_minix_to_cpu16 grub_le_to_cpu16
#define grub_minix_to_cpu32 grub_le_to_cpu32
#endif
#if defined(MODE_MINIX2) || defined(MODE_MINIX3)
typedef grub_uint32_t grub_minix_uintn_t;
#define grub_minix_to_cpu_n grub_minix_to_cpu32
#else
typedef grub_uint16_t grub_minix_uintn_t;
#define grub_minix_to_cpu_n grub_minix_to_cpu16
#endif
#define GRUB_MINIX_INODE_BLKSZ(data) sizeof (grub_minix_uintn_t)
#ifdef MODE_MINIX3
typedef grub_uint32_t grub_minix_ino_t;
#define grub_minix_to_cpu_ino grub_minix_to_cpu32
#else
typedef grub_uint16_t grub_minix_ino_t;
#define grub_minix_to_cpu_ino grub_minix_to_cpu16
#endif
#define GRUB_MINIX_INODE_SIZE(data) (grub_minix_to_cpu32 (data->inode.size))
#define GRUB_MINIX_INODE_MODE(data) (grub_minix_to_cpu16 (data->inode.mode))
#define GRUB_MINIX_INODE_DIR_ZONES(data,blk) (grub_minix_to_cpu_n \
(data->inode.dir_zones[blk]))
#define GRUB_MINIX_INODE_INDIR_ZONE(data) (grub_minix_to_cpu_n \
(data->inode.indir_zone))
#define GRUB_MINIX_INODE_DINDIR_ZONE(data) (grub_minix_to_cpu_n \
(data->inode.double_indir_zone))
#ifndef MODE_MINIX3
#define GRUB_MINIX_LOG2_ZONESZ (GRUB_MINIX_LOG2_BSIZE \
+ grub_minix_to_cpu16 (data->sblock.log2_zone_size))
#endif
#define GRUB_MINIX_ZONESZ ((grub_uint64_t) data->block_size << \
(GRUB_DISK_SECTOR_BITS + grub_minix_to_cpu16 (data->sblock.log2_zone_size)))
#ifdef MODE_MINIX3
#define GRUB_MINIX_ZONE2SECT(zone) ((zone) * data->block_size)
#else
#define GRUB_MINIX_ZONE2SECT(zone) ((zone) << GRUB_MINIX_LOG2_ZONESZ)
#endif
#ifdef MODE_MINIX3
struct grub_minix_sblock
{
grub_uint32_t inode_cnt;
grub_uint16_t zone_cnt;
grub_uint16_t inode_bmap_size;
grub_uint16_t zone_bmap_size;
grub_uint16_t first_data_zone;
grub_uint16_t log2_zone_size;
grub_uint16_t pad;
grub_uint32_t max_file_size;
grub_uint32_t zones;
grub_uint16_t magic;
grub_uint16_t pad2;
grub_uint16_t block_size;
grub_uint8_t disk_version;
};
#else
struct grub_minix_sblock
{
grub_uint16_t inode_cnt;
grub_uint16_t zone_cnt;
grub_uint16_t inode_bmap_size;
grub_uint16_t zone_bmap_size;
grub_uint16_t first_data_zone;
grub_uint16_t log2_zone_size;
grub_uint32_t max_file_size;
grub_uint16_t magic;
};
#endif
#if defined(MODE_MINIX3) || defined(MODE_MINIX2)
struct grub_minix_inode
{
grub_uint16_t mode;
grub_uint16_t nlinks;
grub_uint16_t uid;
grub_uint16_t gid;
grub_uint32_t size;
grub_uint32_t atime;
grub_uint32_t mtime;
grub_uint32_t ctime;
grub_uint32_t dir_zones[7];
grub_uint32_t indir_zone;
grub_uint32_t double_indir_zone;
grub_uint32_t triple_indir_zone;
};
#else
struct grub_minix_inode
{
grub_uint16_t mode;
grub_uint16_t uid;
grub_uint32_t size;
grub_uint32_t mtime;
grub_uint8_t gid;
grub_uint8_t nlinks;
grub_uint16_t dir_zones[7];
grub_uint16_t indir_zone;
grub_uint16_t double_indir_zone;
};
#endif
/* Information about a "mounted" minix filesystem. */
struct grub_minix_data
{
struct grub_minix_sblock sblock;
struct grub_minix_inode inode;
grub_minix_ino_t ino;
int linknest;
grub_disk_t disk;
int filename_size;
grub_size_t block_size;
};
static grub_dl_t my_mod;
static grub_err_t grub_minix_find_file (struct grub_minix_data *data,
const char *path);
/* Read the block pointer in ZONE, on the offset NUM. */
static grub_minix_uintn_t
grub_get_indir (struct grub_minix_data *data,
grub_minix_uintn_t zone,
grub_minix_uintn_t num)
{
grub_minix_uintn_t indirn;
grub_disk_read (data->disk,
GRUB_MINIX_ZONE2SECT(zone),
sizeof (grub_minix_uintn_t) * num,
sizeof (grub_minix_uintn_t), (char *) &indirn);
return grub_minix_to_cpu_n (indirn);
}
static grub_minix_uintn_t
grub_minix_get_file_block (struct grub_minix_data *data, unsigned int blk)
{
grub_minix_uintn_t indir;
const grub_uint32_t block_per_zone = (GRUB_MINIX_ZONESZ
/ GRUB_MINIX_INODE_BLKSZ (data));
/* Direct block. */
if (blk < GRUB_MINIX_INODE_DIR_BLOCKS)
return GRUB_MINIX_INODE_DIR_ZONES (data, blk);
/* Indirect block. */
blk -= GRUB_MINIX_INODE_DIR_BLOCKS;
if (blk < block_per_zone)
{
indir = grub_get_indir (data, GRUB_MINIX_INODE_INDIR_ZONE (data), blk);
return indir;
}
/* Double indirect block. */
blk -= block_per_zone;
if (blk < block_per_zone * block_per_zone)
{
indir = grub_get_indir (data, GRUB_MINIX_INODE_DINDIR_ZONE (data),
blk / block_per_zone);
indir = grub_get_indir (data, indir, blk % block_per_zone);
return indir;
}
#if defined (MODE_MINIX3) || defined (MODE_MINIX2)
blk -= block_per_zone * block_per_zone;
if (blk < ((grub_uint64_t) block_per_zone * (grub_uint64_t) block_per_zone
* (grub_uint64_t) block_per_zone))
{
indir = grub_get_indir (data, grub_minix_to_cpu_n (data->inode.triple_indir_zone),
(blk / block_per_zone) / block_per_zone);
indir = grub_get_indir (data, indir, (blk / block_per_zone) % block_per_zone);
indir = grub_get_indir (data, indir, blk % block_per_zone);
return indir;
}
#endif
/* This should never happen. */
grub_error (GRUB_ERR_OUT_OF_RANGE, "file bigger than maximum size");
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_minix_read_file (struct grub_minix_data *data,
grub_disk_read_hook_t read_hook, void *read_hook_data,
grub_off_t pos, grub_size_t len, char *buf)
{
grub_uint32_t i;
grub_uint32_t blockcnt;
grub_uint32_t posblock;
grub_uint32_t blockoff;
/* Adjust len so it we can't read past the end of the file. */
if (len + pos > GRUB_MINIX_INODE_SIZE (data))
len = GRUB_MINIX_INODE_SIZE (data) - pos;
if (len == 0)
return 0;
/* Files are at most 2G/4G - 1 bytes on minixfs. Avoid 64-bit division. */
blockcnt = ((grub_uint32_t) ((len + pos - 1)
>> GRUB_DISK_SECTOR_BITS)) / data->block_size + 1;
posblock = (((grub_uint32_t) pos)
/ (data->block_size << GRUB_DISK_SECTOR_BITS));
blockoff = (((grub_uint32_t) pos)
% (data->block_size << GRUB_DISK_SECTOR_BITS));
for (i = posblock; i < blockcnt; i++)
{
grub_disk_addr_t blknr;
grub_uint64_t blockend = data->block_size << GRUB_DISK_SECTOR_BITS;
grub_off_t skipfirst = 0;
blknr = grub_minix_get_file_block (data, i);
if (grub_errno)
return -1;
/* Last block. */
if (i == blockcnt - 1)
{
/* len + pos < 4G (checked above), so it doesn't overflow. */
blockend = (((grub_uint32_t) (len + pos))
% (data->block_size << GRUB_DISK_SECTOR_BITS));
if (!blockend)
blockend = data->block_size << GRUB_DISK_SECTOR_BITS;
}
/* First block. */
if (i == posblock)
{
skipfirst = blockoff;
blockend -= skipfirst;
}
data->disk->read_hook = read_hook;
data->disk->read_hook_data = read_hook_data;
grub_disk_read (data->disk,
GRUB_MINIX_ZONE2SECT(blknr),
skipfirst, blockend, buf);
data->disk->read_hook = 0;
if (grub_errno)
return -1;
buf += (data->block_size << GRUB_DISK_SECTOR_BITS) - skipfirst;
}
return len;
}
/* Read inode INO from the mounted filesystem described by DATA. This
inode is used by default now. */
static grub_err_t
grub_minix_read_inode (struct grub_minix_data *data, grub_minix_ino_t ino)
{
struct grub_minix_sblock *sblock = &data->sblock;
/* Block in which the inode is stored. */
grub_disk_addr_t block;
data->ino = ino;
/* The first inode in minix is inode 1. */
ino--;
block = GRUB_MINIX_ZONE2SECT (2 + grub_minix_to_cpu16 (sblock->inode_bmap_size)
+ grub_minix_to_cpu16 (sblock->zone_bmap_size));
block += ino / (GRUB_DISK_SECTOR_SIZE / sizeof (struct grub_minix_inode));
int offs = (ino % (GRUB_DISK_SECTOR_SIZE
/ sizeof (struct grub_minix_inode))
* sizeof (struct grub_minix_inode));
grub_disk_read (data->disk, block, offs,
sizeof (struct grub_minix_inode), &data->inode);
return GRUB_ERR_NONE;
}
/* Lookup the symlink the current inode points to. INO is the inode
number of the directory the symlink is relative to. */
static grub_err_t
grub_minix_lookup_symlink (struct grub_minix_data *data, grub_minix_ino_t ino)
{
char symlink[GRUB_MINIX_INODE_SIZE (data) + 1];
if (++data->linknest > GRUB_MINIX_MAX_SYMLNK_CNT)
return grub_error (GRUB_ERR_SYMLINK_LOOP, N_("too deep nesting of symlinks"));
if (grub_minix_read_file (data, 0, 0, 0,
GRUB_MINIX_INODE_SIZE (data), symlink) < 0)
return grub_errno;
symlink[GRUB_MINIX_INODE_SIZE (data)] = '\0';
/* The symlink is an absolute path, go back to the root inode. */
if (symlink[0] == '/')
ino = GRUB_MINIX_ROOT_INODE;
/* Now load in the old inode. */
if (grub_minix_read_inode (data, ino))
return grub_errno;
grub_minix_find_file (data, symlink);
return grub_errno;
}
/* Find the file with the pathname PATH on the filesystem described by
DATA. */
static grub_err_t
grub_minix_find_file (struct grub_minix_data *data, const char *path)
{
char fpath[grub_strlen (path) + 1];
char *name = fpath;
char *next;
unsigned int pos = 0;
grub_minix_ino_t dirino;
grub_strcpy (fpath, path);
/* Skip the first slash. */
while (*name == '/')
name++;
if (!*name)
return 0;
/* Extract the actual part from the pathname. */
next = grub_strchr (name, '/');
if (next)
{
next[0] = '\0';
next++;
while (*next == '/')
next++;
}
do
{
grub_minix_ino_t ino;
char filename[data->filename_size + 1];
if (grub_strlen (name) == 0)
return GRUB_ERR_NONE;
if (grub_minix_read_file (data, 0, 0, pos, sizeof (ino),
(char *) &ino) < 0)
return grub_errno;
if (grub_minix_read_file (data, 0, 0, pos + sizeof (ino),
data->filename_size, (char *) filename)< 0)
return grub_errno;
filename[data->filename_size] = '\0';
/* Check if the current direntry matches the current part of the
pathname. */
if (!grub_strcmp (name, filename))
{
dirino = data->ino;
grub_minix_read_inode (data, grub_minix_to_cpu_ino (ino));
/* Follow the symlink. */
if ((GRUB_MINIX_INODE_MODE (data)
& GRUB_MINIX_IFLNK) == GRUB_MINIX_IFLNK)
{
grub_minix_lookup_symlink (data, dirino);
if (grub_errno)
return grub_errno;
}
if (!next)
return 0;
pos = 0;
name = next;
next = grub_strchr (name, '/');
if (next)
{
next[0] = '\0';
next++;
while (*next == '/')
next++;
}
if ((GRUB_MINIX_INODE_MODE (data)
& GRUB_MINIX_IFDIR) != GRUB_MINIX_IFDIR)
return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory"));
continue;
}
pos += sizeof (ino) + data->filename_size;
} while (pos < GRUB_MINIX_INODE_SIZE (data));
grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), path);
return grub_errno;
}
/* Mount the filesystem on the disk DISK. */
static struct grub_minix_data *
grub_minix_mount (grub_disk_t disk)
{
struct grub_minix_data *data;
data = grub_malloc (sizeof (struct grub_minix_data));
if (!data)
return 0;
/* Read the superblock. */
grub_disk_read (disk, GRUB_MINIX_SBLOCK, 0,
sizeof (struct grub_minix_sblock),&data->sblock);
if (grub_errno)
goto fail;
if (data->sblock.magic == grub_cpu_to_minix16_compile_time (GRUB_MINIX_MAGIC))
{
#if !defined(MODE_MINIX3)
data->filename_size = 14;
#else
data->filename_size = 60;
#endif
}
#if !defined(MODE_MINIX3)
else if (data->sblock.magic
== grub_cpu_to_minix16_compile_time (GRUB_MINIX_MAGIC_30))
data->filename_size = 30;
#endif
else
goto fail;
/* 20 means 1G zones. We could support up to 31 but already 1G isn't
supported by anything else. */
if (grub_minix_to_cpu16 (data->sblock.log2_zone_size) >= 20)
goto fail;
data->disk = disk;
data->linknest = 0;
#ifdef MODE_MINIX3
/* These tests are endian-independent. No need to byteswap. */
if (data->sblock.block_size == 0xffff)
data->block_size = 2;
else
{
if ((data->sblock.block_size == grub_cpu_to_minix16_compile_time (0x200))
|| (data->sblock.block_size == 0)
|| (data->sblock.block_size & grub_cpu_to_minix16_compile_time (0x1ff)))
goto fail;
data->block_size = grub_minix_to_cpu16 (data->sblock.block_size)
>> GRUB_DISK_SECTOR_BITS;
}
#else
data->block_size = 2;
#endif
return data;
fail:
grub_free (data);
#if defined(MODE_MINIX3)
grub_error (GRUB_ERR_BAD_FS, "not a minix3 filesystem");
#elif defined(MODE_MINIX2)
grub_error (GRUB_ERR_BAD_FS, "not a minix2 filesystem");
#else
grub_error (GRUB_ERR_BAD_FS, "not a minix filesystem");
#endif
return 0;
}
static grub_err_t
grub_minix_dir (grub_device_t device, const char *path,
grub_fs_dir_hook_t hook, void *hook_data)
{
struct grub_minix_data *data = 0;
unsigned int pos = 0;
data = grub_minix_mount (device->disk);
if (!data)
return grub_errno;
grub_minix_read_inode (data, GRUB_MINIX_ROOT_INODE);
if (grub_errno)
goto fail;
grub_minix_find_file (data, path);
if (grub_errno)
goto fail;
if ((GRUB_MINIX_INODE_MODE (data) & GRUB_MINIX_IFDIR) != GRUB_MINIX_IFDIR)
{
grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory"));
goto fail;
}
while (pos < GRUB_MINIX_INODE_SIZE (data))
{
grub_minix_ino_t ino;
char filename[data->filename_size + 1];
grub_minix_ino_t dirino = data->ino;
struct grub_dirhook_info info;
grub_memset (&info, 0, sizeof (info));
if (grub_minix_read_file (data, 0, 0, pos, sizeof (ino),
(char *) &ino) < 0)
return grub_errno;
if (grub_minix_read_file (data, 0, 0, pos + sizeof (ino),
data->filename_size,
(char *) filename) < 0)
return grub_errno;
filename[data->filename_size] = '\0';
if (!ino)
{
pos += sizeof (ino) + data->filename_size;
continue;
}
grub_minix_read_inode (data, grub_minix_to_cpu_ino (ino));
info.dir = ((GRUB_MINIX_INODE_MODE (data)
& GRUB_MINIX_IFDIR) == GRUB_MINIX_IFDIR);
info.mtimeset = 1;
info.mtime = grub_minix_to_cpu32 (data->inode.mtime);
if (hook (filename, &info, hook_data) ? 1 : 0)
break;
/* Load the old inode back in. */
grub_minix_read_inode (data, dirino);
pos += sizeof (ino) + data->filename_size;
}
fail:
grub_free (data);
return grub_errno;
}
/* Open a file named NAME and initialize FILE. */
static grub_err_t
grub_minix_open (struct grub_file *file, const char *name)
{
struct grub_minix_data *data;
data = grub_minix_mount (file->device->disk);
if (!data)
return grub_errno;
/* Open the inode op the root directory. */
grub_minix_read_inode (data, GRUB_MINIX_ROOT_INODE);
if (grub_errno)
{
grub_free (data);
return grub_errno;
}
if (!name || name[0] != '/')
{
grub_error (GRUB_ERR_BAD_FILENAME, N_("invalid file name `%s'"), name);
return grub_errno;
}
/* Traverse the directory tree to the node that should be
opened. */
grub_minix_find_file (data, name);
if (grub_errno)
{
grub_free (data);
return grub_errno;
}
file->data = data;
file->size = GRUB_MINIX_INODE_SIZE (data);
return GRUB_ERR_NONE;
}
static grub_ssize_t
grub_minix_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_minix_data *data =
(struct grub_minix_data *) file->data;
return grub_minix_read_file (data, file->read_hook, file->read_hook_data,
file->offset, len, buf);
}
static grub_err_t
grub_minix_close (grub_file_t file)
{
grub_free (file->data);
return GRUB_ERR_NONE;
}
static struct grub_fs grub_minix_fs =
{
#ifdef MODE_BIGENDIAN
#if defined(MODE_MINIX3)
.name = "minix3_be",
#elif defined(MODE_MINIX2)
.name = "minix2_be",
#else
.name = "minix_be",
#endif
#else
#if defined(MODE_MINIX3)
.name = "minix3",
#elif defined(MODE_MINIX2)
.name = "minix2",
#else
.name = "minix",
#endif
#endif
.dir = grub_minix_dir,
.open = grub_minix_open,
.read = grub_minix_read,
.close = grub_minix_close,
#ifdef GRUB_UTIL
.reserved_first_sector = 1,
.blocklist_install = 1,
#endif
.next = 0
};
#ifdef MODE_BIGENDIAN
#if defined(MODE_MINIX3)
GRUB_MOD_INIT(minix3_be)
#elif defined(MODE_MINIX2)
GRUB_MOD_INIT(minix2_be)
#else
GRUB_MOD_INIT(minix_be)
#endif
#else
#if defined(MODE_MINIX3)
GRUB_MOD_INIT(minix3)
#elif defined(MODE_MINIX2)
GRUB_MOD_INIT(minix2)
#else
GRUB_MOD_INIT(minix)
#endif
#endif
{
grub_fs_register (&grub_minix_fs);
my_mod = mod;
}
#ifdef MODE_BIGENDIAN
#if defined(MODE_MINIX3)
GRUB_MOD_FINI(minix3_be)
#elif defined(MODE_MINIX2)
GRUB_MOD_FINI(minix2_be)
#else
GRUB_MOD_FINI(minix_be)
#endif
#else
#if defined(MODE_MINIX3)
GRUB_MOD_FINI(minix3)
#elif defined(MODE_MINIX2)
GRUB_MOD_FINI(minix2)
#else
GRUB_MOD_FINI(minix)
#endif
#endif
{
grub_fs_unregister (&grub_minix_fs);
}