| /* lzopio.c - decompression support for lzop */ |
| /* |
| * GRUB -- GRand Unified Bootloader |
| * Copyright (C) 2011 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/mm.h> |
| #include <grub/file.h> |
| #include <grub/fs.h> |
| #include <grub/dl.h> |
| #include <grub/crypto.h> |
| #include <minilzo.h> |
| |
| GRUB_MOD_LICENSE ("GPLv3+"); |
| |
| #define LZOP_MAGIC "\x89\x4c\x5a\x4f\x00\x0d\x0a\x1a\x0a" |
| #define LZOP_MAGIC_SIZE 9 |
| #define LZOP_CHECK_SIZE 4 |
| #define LZOP_NEW_LIB 0x0940 |
| |
| /* Header flags - copied from conf.h of LZOP source code. */ |
| #define F_ADLER32_D 0x00000001L |
| #define F_ADLER32_C 0x00000002L |
| #define F_STDIN 0x00000004L |
| #define F_STDOUT 0x00000008L |
| #define F_NAME_DEFAULT 0x00000010L |
| #define F_DOSISH 0x00000020L |
| #define F_H_EXTRA_FIELD 0x00000040L |
| #define F_H_GMTDIFF 0x00000080L |
| #define F_CRC32_D 0x00000100L |
| #define F_CRC32_C 0x00000200L |
| #define F_MULTIPART 0x00000400L |
| #define F_H_FILTER 0x00000800L |
| #define F_H_CRC32 0x00001000L |
| #define F_H_PATH 0x00002000L |
| #define F_MASK 0x00003FFFL |
| |
| struct block_header |
| { |
| grub_uint32_t usize; |
| grub_uint32_t csize; |
| grub_uint32_t ucheck; |
| grub_uint32_t ccheck; |
| unsigned char *cdata; |
| unsigned char *udata; |
| }; |
| |
| struct grub_lzopio |
| { |
| grub_file_t file; |
| int has_ccheck; |
| int has_ucheck; |
| const gcry_md_spec_t *ucheck_fun; |
| const gcry_md_spec_t *ccheck_fun; |
| grub_off_t saved_off; /* Rounded down to block boundary. */ |
| grub_off_t start_block_off; |
| struct block_header block; |
| }; |
| |
| typedef struct grub_lzopio *grub_lzopio_t; |
| static struct grub_fs grub_lzopio_fs; |
| |
| /* Some helper functions. On errors memory allocated by those function is free |
| * either on close() so no risk of leaks. This makes functions simpler. */ |
| |
| /* Read block header from file, after successful exit file points to |
| * beginning of block data. */ |
| static int |
| read_block_header (struct grub_lzopio *lzopio) |
| { |
| lzopio->saved_off += lzopio->block.usize; |
| |
| /* Free cached block data if any. */ |
| grub_free (lzopio->block.udata); |
| grub_free (lzopio->block.cdata); |
| lzopio->block.udata = NULL; |
| lzopio->block.cdata = NULL; |
| |
| if (grub_file_read (lzopio->file, &lzopio->block.usize, |
| sizeof (lzopio->block.usize)) != |
| sizeof (lzopio->block.usize)) |
| return -1; |
| |
| lzopio->block.usize = grub_be_to_cpu32 (lzopio->block.usize); |
| |
| /* Last block has uncompressed data size == 0 and no other fields. */ |
| if (lzopio->block.usize == 0) |
| { |
| if (grub_file_tell (lzopio->file) == grub_file_size (lzopio->file)) |
| return 0; |
| else |
| return -1; |
| } |
| |
| /* Read compressed data block size. */ |
| if (grub_file_read (lzopio->file, &lzopio->block.csize, |
| sizeof (lzopio->block.csize)) != |
| sizeof (lzopio->block.csize)) |
| return -1; |
| |
| lzopio->block.csize = grub_be_to_cpu32 (lzopio->block.csize); |
| |
| /* Corrupted. */ |
| if (lzopio->block.csize > lzopio->block.usize) |
| return -1; |
| |
| /* Read checksum of uncompressed data. */ |
| if (lzopio->has_ucheck) |
| { |
| if (grub_file_read (lzopio->file, &lzopio->block.ucheck, |
| sizeof (lzopio->block.ucheck)) != |
| sizeof (lzopio->block.ucheck)) |
| return -1; |
| |
| lzopio->block.ucheck = lzopio->block.ucheck; |
| } |
| |
| /* Read checksum of compressed data. */ |
| if (lzopio->has_ccheck) |
| { |
| /* Incompressible data block. */ |
| if (lzopio->block.csize == lzopio->block.usize) |
| { |
| lzopio->block.ccheck = lzopio->block.ucheck; |
| } |
| else |
| { |
| if (grub_file_read (lzopio->file, &lzopio->block.ccheck, |
| sizeof (lzopio->block.ccheck)) != |
| sizeof (lzopio->block.ccheck)) |
| return -1; |
| |
| lzopio->block.ccheck = lzopio->block.ccheck; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Read block data into memory. File must be set to beginning of block data. |
| * Can't be called on last block. */ |
| static int |
| read_block_data (struct grub_lzopio *lzopio) |
| { |
| lzopio->block.cdata = grub_malloc (lzopio->block.csize); |
| if (!lzopio->block.cdata) |
| return -1; |
| |
| if (grub_file_read (lzopio->file, lzopio->block.cdata, lzopio->block.csize) |
| != (grub_ssize_t) lzopio->block.csize) |
| return -1; |
| |
| if (lzopio->ccheck_fun) |
| { |
| grub_uint8_t computed_hash[GRUB_CRYPTO_MAX_MDLEN]; |
| |
| if (lzopio->ccheck_fun->mdlen > GRUB_CRYPTO_MAX_MDLEN) |
| return -1; |
| |
| grub_crypto_hash (lzopio->ccheck_fun, computed_hash, |
| lzopio->block.cdata, |
| lzopio->block.csize); |
| |
| if (grub_memcmp |
| (computed_hash, &lzopio->block.ccheck, |
| sizeof (lzopio->block.ccheck)) != 0) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /* Read block data, uncompressed and also store it in memory. */ |
| /* XXX Investigate possibility of in-place decompression to reduce memory |
| * footprint. Or try to uncompress directly to buf if possible. */ |
| static int |
| uncompress_block (struct grub_lzopio *lzopio) |
| { |
| lzo_uint usize = lzopio->block.usize; |
| |
| if (read_block_data (lzopio) < 0) |
| return -1; |
| |
| /* Incompressible data. */ |
| if (lzopio->block.csize == lzopio->block.usize) |
| { |
| lzopio->block.udata = lzopio->block.cdata; |
| lzopio->block.cdata = NULL; |
| } |
| else |
| { |
| lzopio->block.udata = grub_malloc (lzopio->block.usize); |
| if (!lzopio->block.udata) |
| return -1; |
| |
| if (lzo1x_decompress_safe (lzopio->block.cdata, lzopio->block.csize, |
| lzopio->block.udata, &usize, NULL) |
| != LZO_E_OK) |
| return -1; |
| |
| if (lzopio->ucheck_fun) |
| { |
| grub_uint8_t computed_hash[GRUB_CRYPTO_MAX_MDLEN]; |
| |
| if (lzopio->ucheck_fun->mdlen > GRUB_CRYPTO_MAX_MDLEN) |
| return -1; |
| |
| grub_crypto_hash (lzopio->ucheck_fun, computed_hash, |
| lzopio->block.udata, |
| lzopio->block.usize); |
| |
| if (grub_memcmp |
| (computed_hash, &lzopio->block.ucheck, |
| sizeof (lzopio->block.ucheck)) != 0) |
| return -1; |
| } |
| |
| /* Compressed data can be free now. */ |
| grub_free (lzopio->block.cdata); |
| lzopio->block.cdata = NULL; |
| } |
| |
| return 0; |
| } |
| |
| /* Jump to next block and read its header. */ |
| static int |
| jump_block (struct grub_lzopio *lzopio) |
| { |
| /* only jump if block was not decompressed (and read from disk) */ |
| if (!lzopio->block.udata) |
| { |
| grub_off_t off = grub_file_tell (lzopio->file) + lzopio->block.csize; |
| |
| if (grub_file_seek (lzopio->file, off) == ((grub_off_t) - 1)) |
| return -1; |
| } |
| |
| return read_block_header (lzopio); |
| } |
| |
| static int |
| calculate_uncompressed_size (grub_file_t file) |
| { |
| grub_lzopio_t lzopio = file->data; |
| grub_off_t usize_total = 0; |
| |
| if (read_block_header (lzopio) < 0) |
| return -1; |
| |
| /* FIXME: Don't do this for not easily seekable files. */ |
| while (lzopio->block.usize != 0) |
| { |
| usize_total += lzopio->block.usize; |
| |
| if (jump_block (lzopio) < 0) |
| return -1; |
| } |
| |
| file->size = usize_total; |
| |
| return 0; |
| } |
| |
| struct lzop_header |
| { |
| grub_uint8_t magic[LZOP_MAGIC_SIZE]; |
| grub_uint16_t lzop_version; |
| grub_uint16_t lib_version; |
| grub_uint16_t lib_version_ext; |
| grub_uint8_t method; |
| grub_uint8_t level; |
| grub_uint32_t flags; |
| /* grub_uint32_t filter; */ /* No filters support. Rarely used anyway. */ |
| grub_uint32_t mode; |
| grub_uint32_t mtime_lo; |
| grub_uint32_t mtime_hi; |
| grub_uint8_t name_len; |
| } GRUB_PACKED; |
| |
| static int |
| test_header (grub_file_t file) |
| { |
| grub_lzopio_t lzopio = file->data; |
| struct lzop_header header; |
| grub_uint32_t flags, checksum; |
| const gcry_md_spec_t *hcheck; |
| grub_uint8_t *context = NULL; |
| grub_uint8_t *name = NULL; |
| |
| if (grub_file_read (lzopio->file, &header, sizeof (header)) != sizeof (header)) |
| return 0; |
| |
| if (grub_memcmp (header.magic, LZOP_MAGIC, LZOP_MAGIC_SIZE) != 0) |
| return 0; |
| |
| if (grub_be_to_cpu16(header.lib_version) < LZOP_NEW_LIB) |
| return 0; |
| |
| /* Too new version, should upgrade minilzo? */ |
| if (grub_be_to_cpu16 (header.lib_version_ext) > MINILZO_VERSION) |
| return 0; |
| |
| flags = grub_be_to_cpu32 (header.flags); |
| |
| if (flags & F_CRC32_D) |
| { |
| lzopio->has_ucheck = 1; |
| lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("crc32"); |
| } |
| else if (flags & F_ADLER32_D) |
| { |
| lzopio->has_ucheck = 1; |
| lzopio->ucheck_fun = grub_crypto_lookup_md_by_name ("adler32"); |
| } |
| |
| if (flags & F_CRC32_C) |
| { |
| lzopio->has_ccheck = 1; |
| lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("crc32"); |
| } |
| else if (flags & F_ADLER32_C) |
| { |
| lzopio->has_ccheck = 1; |
| lzopio->ccheck_fun = grub_crypto_lookup_md_by_name ("adler32"); |
| } |
| |
| if (flags & F_H_CRC32) |
| hcheck = grub_crypto_lookup_md_by_name ("crc32"); |
| else |
| hcheck = grub_crypto_lookup_md_by_name ("adler32"); |
| |
| if (hcheck) { |
| context = grub_malloc(hcheck->contextsize); |
| if (! context) |
| return 0; |
| |
| hcheck->init(context); |
| |
| /* MAGIC is not included in check calculation. */ |
| hcheck->write(context, &header.lzop_version, sizeof(header)- LZOP_MAGIC_SIZE); |
| } |
| |
| if (header.name_len != 0) |
| { |
| name = grub_malloc (header.name_len); |
| if (! name) |
| { |
| grub_free (context); |
| return 0; |
| } |
| |
| if (grub_file_read (lzopio->file, name, header.name_len) != |
| header.name_len) |
| { |
| grub_free(name); |
| goto CORRUPTED; |
| } |
| |
| if (hcheck) |
| hcheck->write(context, name, header.name_len); |
| |
| grub_free(name); |
| } |
| |
| if (hcheck) |
| hcheck->final(context); |
| |
| if (grub_file_read (lzopio->file, &checksum, sizeof (checksum)) != |
| sizeof (checksum)) |
| goto CORRUPTED; |
| |
| if (hcheck && grub_memcmp (&checksum, hcheck->read(context), sizeof(checksum)) != 0) |
| goto CORRUPTED; |
| |
| lzopio->start_block_off = grub_file_tell (lzopio->file); |
| |
| if (calculate_uncompressed_size (file) < 0) |
| goto CORRUPTED; |
| |
| /* Get back to start block. */ |
| grub_file_seek (lzopio->file, lzopio->start_block_off); |
| |
| /* Read first block - grub_lzopio_read() expects valid block. */ |
| if (read_block_header (lzopio) < 0) |
| goto CORRUPTED; |
| |
| lzopio->saved_off = 0; |
| return 1; |
| |
| CORRUPTED: |
| return 0; |
| } |
| |
| static grub_file_t |
| grub_lzopio_open (grub_file_t io, enum grub_file_type type) |
| { |
| grub_file_t file; |
| grub_lzopio_t lzopio; |
| |
| if (type & GRUB_FILE_TYPE_NO_DECOMPRESS) |
| return io; |
| |
| file = (grub_file_t) grub_zalloc (sizeof (*file)); |
| if (!file) |
| return 0; |
| |
| lzopio = grub_zalloc (sizeof (*lzopio)); |
| if (!lzopio) |
| { |
| grub_free (file); |
| return 0; |
| } |
| |
| lzopio->file = io; |
| |
| file->device = io->device; |
| file->data = lzopio; |
| file->fs = &grub_lzopio_fs; |
| file->size = GRUB_FILE_SIZE_UNKNOWN; |
| file->not_easily_seekable = 1; |
| |
| if (grub_file_tell (lzopio->file) != 0) |
| grub_file_seek (lzopio->file, 0); |
| |
| if (!test_header (file)) |
| { |
| grub_errno = GRUB_ERR_NONE; |
| grub_file_seek (io, 0); |
| grub_free (lzopio); |
| grub_free (file); |
| |
| return io; |
| } |
| |
| return file; |
| } |
| |
| static grub_ssize_t |
| grub_lzopio_read (grub_file_t file, char *buf, grub_size_t len) |
| { |
| grub_lzopio_t lzopio = file->data; |
| grub_ssize_t ret = 0; |
| grub_off_t off; |
| |
| /* Backward seek before last read block. */ |
| if (lzopio->saved_off > grub_file_tell (file)) |
| { |
| grub_file_seek (lzopio->file, lzopio->start_block_off); |
| |
| if (read_block_header (lzopio) < 0) |
| goto CORRUPTED; |
| |
| lzopio->saved_off = 0; |
| } |
| |
| /* Forward to first block with requested data. */ |
| while (lzopio->saved_off + lzopio->block.usize <= grub_file_tell (file)) |
| { |
| /* EOF, could be possible files with unknown size. */ |
| if (lzopio->block.usize == 0) |
| return 0; |
| |
| if (jump_block (lzopio) < 0) |
| goto CORRUPTED; |
| } |
| |
| off = grub_file_tell (file) - lzopio->saved_off; |
| |
| while (len != 0 && lzopio->block.usize != 0) |
| { |
| grub_size_t to_copy; |
| |
| /* Block not decompressed yet. */ |
| if (!lzopio->block.udata && uncompress_block (lzopio) < 0) |
| goto CORRUPTED; |
| |
| /* Copy requested data into buffer. */ |
| to_copy = lzopio->block.usize - off; |
| if (to_copy > len) |
| to_copy = len; |
| grub_memcpy (buf, lzopio->block.udata + off, to_copy); |
| |
| len -= to_copy; |
| buf += to_copy; |
| ret += to_copy; |
| off = 0; |
| |
| /* Read next block if needed. */ |
| if (len > 0 && read_block_header (lzopio) < 0) |
| goto CORRUPTED; |
| } |
| |
| return ret; |
| |
| CORRUPTED: |
| grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, N_("lzop file corrupted")); |
| return -1; |
| } |
| |
| /* Release everything, including the underlying file object. */ |
| static grub_err_t |
| grub_lzopio_close (grub_file_t file) |
| { |
| grub_lzopio_t lzopio = file->data; |
| |
| grub_file_close (lzopio->file); |
| grub_free (lzopio->block.cdata); |
| grub_free (lzopio->block.udata); |
| grub_free (lzopio); |
| |
| /* Device must not be closed twice. */ |
| file->device = 0; |
| file->name = 0; |
| return grub_errno; |
| } |
| |
| static struct grub_fs grub_lzopio_fs = { |
| .name = "lzopio", |
| .dir = 0, |
| .open = 0, |
| .read = grub_lzopio_read, |
| .close = grub_lzopio_close, |
| .label = 0, |
| .next = 0 |
| }; |
| |
| GRUB_MOD_INIT (lzopio) |
| { |
| grub_file_filter_register (GRUB_FILE_FILTER_LZOPIO, grub_lzopio_open); |
| } |
| |
| GRUB_MOD_FINI (lzopio) |
| { |
| grub_file_filter_unregister (GRUB_FILE_FILTER_LZOPIO); |
| } |