diff options
Diffstat (limited to 'grub-core/fs/minix.c')
-rw-r--r-- | grub-core/fs/minix.c | 758 |
1 files changed, 758 insertions, 0 deletions
diff --git a/grub-core/fs/minix.c b/grub-core/fs/minix.c new file mode 100644 index 0000000..3cd18c8 --- /dev/null +++ b/grub-core/fs/minix.c @@ -0,0 +1,758 @@ +/* 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 <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/i18n.h> + +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 EXT2_MAGIC 0xEF53 + +#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 + +#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)) + + +#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 + +#if defined(MODE_MINIX3) +#define MAX_MINIX_FILENAME_SIZE 60 +#else +#define MAX_MINIX_FILENAME_SIZE 30 +#endif + +/* Information about a "mounted" minix filesystem. */ +struct grub_minix_data +{ + struct grub_minix_sblock sblock; + struct grub_minix_inode inode; + grub_uint32_t block_per_zone; + 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); + +#ifdef MODE_MINIX3 +static inline grub_disk_addr_t +grub_minix_zone2sect (struct grub_minix_data *data, grub_minix_uintn_t zone) +{ + return ((grub_disk_addr_t) zone) * data->block_size; +} +#else +static inline grub_disk_addr_t +grub_minix_zone2sect (struct grub_minix_data *data, grub_minix_uintn_t zone) +{ + int log2_zonesz = (GRUB_MINIX_LOG2_BSIZE + + grub_minix_to_cpu16 (data->sblock.log2_zone_size)); + return (((grub_disk_addr_t) zone) << log2_zonesz); +} +#endif + + + /* 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(data, 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; + + /* 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 < data->block_per_zone) + { + indir = grub_get_indir (data, GRUB_MINIX_INODE_INDIR_ZONE (data), blk); + return indir; + } + + /* Double indirect block. */ + blk -= data->block_per_zone; + if (blk < (grub_uint64_t) data->block_per_zone * (grub_uint64_t) data->block_per_zone) + { + indir = grub_get_indir (data, GRUB_MINIX_INODE_DINDIR_ZONE (data), + blk / data->block_per_zone); + + indir = grub_get_indir (data, indir, blk % data->block_per_zone); + + return indir; + } + +#if defined (MODE_MINIX3) || defined (MODE_MINIX2) + blk -= data->block_per_zone * data->block_per_zone; + if (blk < ((grub_uint64_t) data->block_per_zone * (grub_uint64_t) data->block_per_zone + * (grub_uint64_t) data->block_per_zone)) + { + indir = grub_get_indir (data, grub_minix_to_cpu_n (data->inode.triple_indir_zone), + (blk / data->block_per_zone) / data->block_per_zone); + indir = grub_get_indir (data, indir, (blk / data->block_per_zone) % data->block_per_zone); + indir = grub_get_indir (data, indir, blk % data->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; + + if (pos > GRUB_MINIX_INODE_SIZE (data)) + { + grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("attempt to read past the end of file")); + return -1; + } + + /* 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_minix_uintn_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(data, 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 (data, + 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_size_t sz = GRUB_MINIX_INODE_SIZE (data); + + if (++data->linknest > GRUB_MINIX_MAX_SYMLNK_CNT) + return grub_error (GRUB_ERR_SYMLINK_LOOP, N_("too deep nesting of symlinks")); + + symlink = grub_malloc (sz + 1); + if (!symlink) + return grub_errno; + if (grub_minix_read_file (data, 0, 0, 0, sz, symlink) < 0) + return grub_errno; + + symlink[sz] = '\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) +{ + const char *name; + const char *next = path; + unsigned int pos = 0; + grub_minix_ino_t dirino; + + while (1) + { + name = next; + /* Skip the first slash. */ + while (*name == '/') + name++; + if (!*name) + return GRUB_ERR_NONE; + + if ((GRUB_MINIX_INODE_MODE (data) + & GRUB_MINIX_IFDIR) != GRUB_MINIX_IFDIR) + return grub_error (GRUB_ERR_BAD_FILE_TYPE, N_("not a directory")); + + /* Extract the actual part from the pathname. */ + for (next = name; *next && *next != '/'; next++); + + for (pos = 0; ; ) + { + grub_minix_ino_t ino; + char filename[MAX_MINIX_FILENAME_SIZE + 1]; + + if (pos >= GRUB_MINIX_INODE_SIZE (data)) + { + grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), path); + return grub_errno; + } + + 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; + + pos += sizeof (ino) + data->filename_size; + + filename[data->filename_size] = '\0'; + + /* Check if the current direntry matches the current part of the + pathname. */ + if (grub_strncmp (name, filename, next - name) == 0 + && filename[next - name] == '\0') + { + 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; + } + + break; + } + } + } +} + + +/* Mount the filesystem on the disk DISK. */ +static struct grub_minix_data * +grub_minix_mount (grub_disk_t disk) +{ + struct grub_minix_data *data = NULL; + grub_uint16_t ext2_marker; + + grub_disk_read (disk, 2, 56, sizeof (ext2_marker), &ext2_marker); + if (grub_errno != GRUB_ERR_NONE) + goto fail; + + /* + * The ext2 filesystems can sometimes be mistakenly identified as MINIX, e.g. + * due to the number of free ext2 inodes being written to the same location + * where the MINIX superblock magic is found. Avoid such situations by + * skipping any filesystems that have the ext2 superblock magic. + */ + if (ext2_marker == grub_cpu_to_le16_compile_time (EXT2_MAGIC)) + goto fail; + + 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 + + data->block_per_zone = (((grub_uint64_t) data->block_size << \ + (GRUB_DISK_SECTOR_BITS + grub_minix_to_cpu16 (data->sblock.log2_zone_size))) + / sizeof (grub_minix_uintn_t)); + if (!data->block_per_zone) + goto fail; + + 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[MAX_MINIX_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 + .fs_dir = grub_minix_dir, + .fs_open = grub_minix_open, + .fs_read = grub_minix_read, + .fs_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); +} |