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-rw-r--r--grub-core/io/lzopio.c546
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);
+}
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