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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:54:16 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:54:16 +0000 |
commit | 485f6ecd453d8a2fd8b9b9fadea03159d8b50797 (patch) | |
tree | 32451fa3cdd9321fb2591fada9891b2cb70a9cd1 /grub-core/io/lzopio.c | |
parent | Initial commit. (diff) | |
download | grub2-upstream.tar.xz grub2-upstream.zip |
Adding upstream version 2.06.upstream/2.06upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | grub-core/io/lzopio.c | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/grub-core/io/lzopio.c b/grub-core/io/lzopio.c new file mode 100644 index 0000000..a7d4425 --- /dev/null +++ b/grub-core/io/lzopio.c @@ -0,0 +1,546 @@ +/* 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; + } + + /* 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; + } + } + + 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", + .fs_dir = 0, + .fs_open = 0, + .fs_read = grub_lzopio_read, + .fs_close = grub_lzopio_close, + .fs_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); +} |