mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
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1358 lines
36 KiB
C
1358 lines
36 KiB
C
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/* gzio.c - decompression support for gzip */
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/*
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 1999,2005,2006,2007,2009 Free Software Foundation, Inc.
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*
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* Most of this file was originally the source file "inflate.c", written
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* by Mark Adler. It has been very heavily modified. In particular, the
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* original would run through the whole file at once, and this version can
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* be stopped and restarted on any boundary during the decompression process.
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*
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* The license and header comments that file are included here.
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*/
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/* inflate.c -- Not copyrighted 1992 by Mark Adler
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version c10p1, 10 January 1993 */
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/* You can do whatever you like with this source file, though I would
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prefer that if you modify it and redistribute it that you include
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comments to that effect with your name and the date. Thank you.
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*/
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#include <grub/err.h>
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#include <grub/types.h>
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#include <grub/mm.h>
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#include <grub/misc.h>
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#include <grub/fs.h>
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#include <grub/file.h>
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#include <grub/dl.h>
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#include <grub/deflate.h>
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#include <grub/i18n.h>
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GRUB_MOD_LICENSE ("GPLv3+");
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/*
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* Window Size
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*
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* This must be a power of two, and at least 32K for zip's deflate method
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*/
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#define WSIZE 0x8000
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#define INBUFSIZ 0x2000
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/* The state stored in filesystem-specific data. */
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struct grub_gzio
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{
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/* The underlying file object. */
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grub_file_t file;
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/* If input is in memory following fields are used instead of file. */
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grub_size_t mem_input_size, mem_input_off;
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grub_uint8_t *mem_input;
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/* The offset at which the data starts in the underlying file. */
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grub_off_t data_offset;
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/* The type of current block. */
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int block_type;
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/* The length of current block. */
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int block_len;
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/* The flag of the last block. */
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int last_block;
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/* The flag of codes. */
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int code_state;
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/* The length of a copy. */
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unsigned inflate_n;
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/* The index of a copy. */
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unsigned inflate_d;
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/* The input buffer. */
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grub_uint8_t inbuf[INBUFSIZ];
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int inbuf_d;
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/* The bit buffer. */
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unsigned long bb;
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/* The bits in the bit buffer. */
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unsigned bk;
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/* The sliding window in uncompressed data. */
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grub_uint8_t slide[WSIZE];
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/* Current position in the slide. */
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unsigned wp;
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/* The literal/length code table. */
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struct huft *tl;
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/* The distance code table. */
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struct huft *td;
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/* The lookup bits for the literal/length code table. */
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int bl;
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/* The lookup bits for the distance code table. */
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int bd;
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/* The original offset value. */
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grub_off_t saved_offset;
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};
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typedef struct grub_gzio *grub_gzio_t;
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/* Declare the filesystem structure for grub_gzio_open. */
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static struct grub_fs grub_gzio_fs;
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/* Function prototypes */
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static void initialize_tables (grub_gzio_t);
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/* Eat variable-length header fields. */
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static int
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eat_field (grub_file_t file, int len)
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{
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char ch = 1;
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int not_retval = 1;
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do
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{
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if (len >= 0)
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{
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if (! (len--))
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break;
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}
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else
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{
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if (! ch)
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break;
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}
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}
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while ((not_retval = grub_file_read (file, &ch, 1)) == 1);
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return ! not_retval;
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}
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/* Little-Endian defines for the 2-byte magic numbers for gzip files. */
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#define GZIP_MAGIC grub_le_to_cpu16 (0x8B1F)
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#define OLD_GZIP_MAGIC grub_le_to_cpu16 (0x9E1F)
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/* Compression methods (see algorithm.doc) */
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#define STORED 0
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#define COMPRESSED 1
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#ifndef PACKED
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#define PACKED 2
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#else /* PACKED is in use */
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#define GZPACKED 2
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#endif
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#define LZHED 3
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/* methods 4 to 7 reserved */
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#define DEFLATED 8
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#define MAX_METHODS 9
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/* gzip flag byte */
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#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
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#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
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#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
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#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
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#define COMMENT 0x10 /* bit 4 set: file comment present */
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#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
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#define RESERVED 0xC0 /* bit 6,7: reserved */
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#define UNSUPPORTED_FLAGS (CONTINUATION | ENCRYPTED | RESERVED)
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/* inflate block codes */
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#define INFLATE_STORED 0
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#define INFLATE_FIXED 1
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#define INFLATE_DYNAMIC 2
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typedef unsigned char uch;
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typedef unsigned short ush;
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typedef unsigned long ulg;
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static int
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test_gzip_header (grub_file_t file)
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{
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struct {
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grub_uint16_t magic;
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grub_uint8_t method;
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grub_uint8_t flags;
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grub_uint32_t timestamp;
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grub_uint8_t extra_flags;
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grub_uint8_t os_type;
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} hdr;
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grub_uint16_t extra_len;
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grub_uint32_t orig_len;
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grub_gzio_t gzio = file->data;
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if (grub_file_tell (gzio->file) != 0)
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grub_file_seek (gzio->file, 0);
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/*
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* This checks if the file is gzipped. If a problem occurs here
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* (other than a real error with the disk) then we don't think it
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* is a compressed file, and simply mark it as such.
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*/
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if (grub_file_read (gzio->file, &hdr, 10) != 10
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|| ((hdr.magic != GZIP_MAGIC)
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&& (hdr.magic != OLD_GZIP_MAGIC)))
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return 0;
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/*
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* This does consistency checking on the header data. If a
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* problem occurs from here on, then we have corrupt or otherwise
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* bad data, and the error should be reported to the user.
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*/
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if (hdr.method != DEFLATED
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|| (hdr.flags & UNSUPPORTED_FLAGS)
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|| ((hdr.flags & EXTRA_FIELD)
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&& (grub_file_read (gzio->file, &extra_len, 2) != 2
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|| eat_field (gzio->file,
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grub_le_to_cpu16 (extra_len))))
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|| ((hdr.flags & ORIG_NAME) && eat_field (gzio->file, -1))
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|| ((hdr.flags & COMMENT) && eat_field (gzio->file, -1)))
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return 0;
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gzio->data_offset = grub_file_tell (gzio->file);
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/* FIXME: don't do this on not easily seekable files. */
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{
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grub_file_seek (gzio->file, grub_file_size (gzio->file) - 4);
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if (grub_file_read (gzio->file, &orig_len, 4) != 4)
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return 0;
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/* FIXME: this does not handle files whose original size is over 4GB.
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But how can we know the real original size? */
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file->size = grub_le_to_cpu32 (orig_len);
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}
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initialize_tables (gzio);
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return 1;
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}
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/* Huffman code lookup table entry--this entry is four bytes for machines
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that have 16-bit pointers (e.g. PC's in the small or medium model).
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Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16
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means that v is a literal, 16 < e < 32 means that v is a pointer to
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the next table, which codes e - 16 bits, and lastly e == 99 indicates
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an unused code. If a code with e == 99 is looked up, this implies an
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error in the data. */
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struct huft
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{
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uch e; /* number of extra bits or operation */
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uch b; /* number of bits in this code or subcode */
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union
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{
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ush n; /* literal, length base, or distance base */
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struct huft *t; /* pointer to next level of table */
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}
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v;
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};
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/* The inflate algorithm uses a sliding 32K byte window on the uncompressed
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stream to find repeated byte strings. This is implemented here as a
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circular buffer. The index is updated simply by incrementing and then
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and'ing with 0x7fff (32K-1). */
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/* It is left to other modules to supply the 32K area. It is assumed
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to be usable as if it were declared "uch slide[32768];" or as just
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"uch *slide;" and then malloc'ed in the latter case. The definition
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must be in unzip.h, included above. */
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/* Tables for deflate from PKZIP's appnote.txt. */
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static unsigned bitorder[] =
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{ /* Order of the bit length code lengths */
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16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
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static ush cplens[] =
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{ /* Copy lengths for literal codes 257..285 */
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3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
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35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
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/* note: see note #13 above about the 258 in this list. */
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static ush cplext[] =
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{ /* Extra bits for literal codes 257..285 */
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0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
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3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
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static ush cpdist[] =
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{ /* Copy offsets for distance codes 0..29 */
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1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
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257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
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8193, 12289, 16385, 24577};
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static ush cpdext[] =
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{ /* Extra bits for distance codes */
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0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
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7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
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12, 12, 13, 13};
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/*
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Huffman code decoding is performed using a multi-level table lookup.
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The fastest way to decode is to simply build a lookup table whose
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size is determined by the longest code. However, the time it takes
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to build this table can also be a factor if the data being decoded
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is not very long. The most common codes are necessarily the
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shortest codes, so those codes dominate the decoding time, and hence
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the speed. The idea is you can have a shorter table that decodes the
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shorter, more probable codes, and then point to subsidiary tables for
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the longer codes. The time it costs to decode the longer codes is
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then traded against the time it takes to make longer tables.
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This results of this trade are in the variables lbits and dbits
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below. lbits is the number of bits the first level table for literal/
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length codes can decode in one step, and dbits is the same thing for
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the distance codes. Subsequent tables are also less than or equal to
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those sizes. These values may be adjusted either when all of the
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codes are shorter than that, in which case the longest code length in
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bits is used, or when the shortest code is *longer* than the requested
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table size, in which case the length of the shortest code in bits is
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used.
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There are two different values for the two tables, since they code a
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different number of possibilities each. The literal/length table
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codes 286 possible values, or in a flat code, a little over eight
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bits. The distance table codes 30 possible values, or a little less
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than five bits, flat. The optimum values for speed end up being
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about one bit more than those, so lbits is 8+1 and dbits is 5+1.
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The optimum values may differ though from machine to machine, and
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possibly even between compilers. Your mileage may vary.
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*/
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static int lbits = 9; /* bits in base literal/length lookup table */
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static int dbits = 6; /* bits in base distance lookup table */
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/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
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#define BMAX 16 /* maximum bit length of any code (16 for explode) */
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#define N_MAX 288 /* maximum number of codes in any set */
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|||
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|||
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/* Macros for inflate() bit peeking and grabbing.
|
|||
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The usage is:
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|||
|
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NEEDBITS(j)
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x = b & mask_bits[j];
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DUMPBITS(j)
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|
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where NEEDBITS makes sure that b has at least j bits in it, and
|
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DUMPBITS removes the bits from b. The macros use the variable k
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for the number of bits in b. Normally, b and k are register
|
|||
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variables for speed, and are initialized at the beginning of a
|
|||
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routine that uses these macros from a global bit buffer and count.
|
|||
|
|
|||
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If we assume that EOB will be the longest code, then we will never
|
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ask for bits with NEEDBITS that are beyond the end of the stream.
|
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So, NEEDBITS should not read any more bytes than are needed to
|
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meet the request. Then no bytes need to be "returned" to the buffer
|
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at the end of the last block.
|
|||
|
|
|||
|
However, this assumption is not true for fixed blocks--the EOB code
|
|||
|
is 7 bits, but the other literal/length codes can be 8 or 9 bits.
|
|||
|
(The EOB code is shorter than other codes because fixed blocks are
|
|||
|
generally short. So, while a block always has an EOB, many other
|
|||
|
literal/length codes have a significantly lower probability of
|
|||
|
showing up at all.) However, by making the first table have a
|
|||
|
lookup of seven bits, the EOB code will be found in that first
|
|||
|
lookup, and so will not require that too many bits be pulled from
|
|||
|
the stream.
|
|||
|
*/
|
|||
|
|
|||
|
static ush mask_bits[] =
|
|||
|
{
|
|||
|
0x0000,
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|||
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0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
|
|||
|
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
|
|||
|
};
|
|||
|
|
|||
|
#define NEEDBITS(n) do {while(k<(n)){b|=((ulg)get_byte(gzio))<<k;k+=8;}} while (0)
|
|||
|
#define DUMPBITS(n) do {b>>=(n);k-=(n);} while (0)
|
|||
|
|
|||
|
static int
|
|||
|
get_byte (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
if (gzio->mem_input)
|
|||
|
{
|
|||
|
if (gzio->mem_input_off < gzio->mem_input_size)
|
|||
|
return gzio->mem_input[gzio->mem_input_off++];
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
if (gzio->file && (grub_file_tell (gzio->file)
|
|||
|
== (grub_off_t) gzio->data_offset
|
|||
|
|| gzio->inbuf_d == INBUFSIZ))
|
|||
|
{
|
|||
|
gzio->inbuf_d = 0;
|
|||
|
grub_file_read (gzio->file, gzio->inbuf, INBUFSIZ);
|
|||
|
}
|
|||
|
|
|||
|
return gzio->inbuf[gzio->inbuf_d++];
|
|||
|
}
|
|||
|
|
|||
|
static void
|
|||
|
gzio_seek (grub_gzio_t gzio, grub_off_t off)
|
|||
|
{
|
|||
|
if (gzio->mem_input)
|
|||
|
{
|
|||
|
if (off > gzio->mem_input_size)
|
|||
|
grub_error (GRUB_ERR_OUT_OF_RANGE,
|
|||
|
N_("attempt to seek outside of the file"));
|
|||
|
else
|
|||
|
gzio->mem_input_off = off;
|
|||
|
}
|
|||
|
else
|
|||
|
grub_file_seek (gzio->file, off);
|
|||
|
}
|
|||
|
|
|||
|
/* more function prototypes */
|
|||
|
static int huft_build (unsigned *, unsigned, unsigned, ush *, ush *,
|
|||
|
struct huft **, int *);
|
|||
|
static int huft_free (struct huft *);
|
|||
|
static int inflate_codes_in_window (grub_gzio_t);
|
|||
|
|
|||
|
|
|||
|
/* Given a list of code lengths and a maximum table size, make a set of
|
|||
|
tables to decode that set of codes. Return zero on success, one if
|
|||
|
the given code set is incomplete (the tables are still built in this
|
|||
|
case), two if the input is invalid (all zero length codes or an
|
|||
|
oversubscribed set of lengths), and three if not enough memory. */
|
|||
|
|
|||
|
static int
|
|||
|
huft_build (unsigned *b, /* code lengths in bits (all assumed <= BMAX) */
|
|||
|
unsigned n, /* number of codes (assumed <= N_MAX) */
|
|||
|
unsigned s, /* number of simple-valued codes (0..s-1) */
|
|||
|
ush * d, /* list of base values for non-simple codes */
|
|||
|
ush * e, /* list of extra bits for non-simple codes */
|
|||
|
struct huft **t, /* result: starting table */
|
|||
|
int *m) /* maximum lookup bits, returns actual */
|
|||
|
{
|
|||
|
unsigned a; /* counter for codes of length k */
|
|||
|
unsigned c[BMAX + 1]; /* bit length count table */
|
|||
|
unsigned f; /* i repeats in table every f entries */
|
|||
|
int g; /* maximum code length */
|
|||
|
int h; /* table level */
|
|||
|
register unsigned i; /* counter, current code */
|
|||
|
register unsigned j; /* counter */
|
|||
|
register int k; /* number of bits in current code */
|
|||
|
int l; /* bits per table (returned in m) */
|
|||
|
register unsigned *p; /* pointer into c[], b[], or v[] */
|
|||
|
register struct huft *q; /* points to current table */
|
|||
|
struct huft r; /* table entry for structure assignment */
|
|||
|
struct huft *u[BMAX]; /* table stack */
|
|||
|
unsigned v[N_MAX]; /* values in order of bit length */
|
|||
|
register int w; /* bits before this table == (l * h) */
|
|||
|
unsigned x[BMAX + 1]; /* bit offsets, then code stack */
|
|||
|
unsigned *xp; /* pointer into x */
|
|||
|
int y; /* number of dummy codes added */
|
|||
|
unsigned z; /* number of entries in current table */
|
|||
|
|
|||
|
/* Generate counts for each bit length */
|
|||
|
grub_memset ((char *) c, 0, sizeof (c));
|
|||
|
p = b;
|
|||
|
i = n;
|
|||
|
do
|
|||
|
{
|
|||
|
c[*p]++; /* assume all entries <= BMAX */
|
|||
|
p++; /* Can't combine with above line (Solaris bug) */
|
|||
|
}
|
|||
|
while (--i);
|
|||
|
if (c[0] == n) /* null input--all zero length codes */
|
|||
|
{
|
|||
|
*t = (struct huft *) NULL;
|
|||
|
*m = 0;
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
/* Find minimum and maximum length, bound *m by those */
|
|||
|
l = *m;
|
|||
|
for (j = 1; j <= BMAX; j++)
|
|||
|
if (c[j])
|
|||
|
break;
|
|||
|
k = j; /* minimum code length */
|
|||
|
if ((unsigned) l < j)
|
|||
|
l = j;
|
|||
|
for (i = BMAX; i; i--)
|
|||
|
if (c[i])
|
|||
|
break;
|
|||
|
g = i; /* maximum code length */
|
|||
|
if ((unsigned) l > i)
|
|||
|
l = i;
|
|||
|
*m = l;
|
|||
|
|
|||
|
/* Adjust last length count to fill out codes, if needed */
|
|||
|
for (y = 1 << j; j < i; j++, y <<= 1)
|
|||
|
if ((y -= c[j]) < 0)
|
|||
|
return 2; /* bad input: more codes than bits */
|
|||
|
if ((y -= c[i]) < 0)
|
|||
|
return 2;
|
|||
|
c[i] += y;
|
|||
|
|
|||
|
/* Generate starting offsets into the value table for each length */
|
|||
|
x[1] = j = 0;
|
|||
|
p = c + 1;
|
|||
|
xp = x + 2;
|
|||
|
while (--i)
|
|||
|
{ /* note that i == g from above */
|
|||
|
*xp++ = (j += *p++);
|
|||
|
}
|
|||
|
|
|||
|
/* Make a table of values in order of bit lengths */
|
|||
|
p = b;
|
|||
|
i = 0;
|
|||
|
do
|
|||
|
{
|
|||
|
if ((j = *p++) != 0)
|
|||
|
v[x[j]++] = i;
|
|||
|
}
|
|||
|
while (++i < n);
|
|||
|
|
|||
|
/* Generate the Huffman codes and for each, make the table entries */
|
|||
|
x[0] = i = 0; /* first Huffman code is zero */
|
|||
|
p = v; /* grab values in bit order */
|
|||
|
h = -1; /* no tables yet--level -1 */
|
|||
|
w = -l; /* bits decoded == (l * h) */
|
|||
|
u[0] = (struct huft *) NULL; /* just to keep compilers happy */
|
|||
|
q = (struct huft *) NULL; /* ditto */
|
|||
|
z = 0; /* ditto */
|
|||
|
|
|||
|
/* go through the bit lengths (k already is bits in shortest code) */
|
|||
|
for (; k <= g; k++)
|
|||
|
{
|
|||
|
a = c[k];
|
|||
|
while (a--)
|
|||
|
{
|
|||
|
/* here i is the Huffman code of length k bits for value *p */
|
|||
|
/* make tables up to required level */
|
|||
|
while (k > w + l)
|
|||
|
{
|
|||
|
h++;
|
|||
|
w += l; /* previous table always l bits */
|
|||
|
|
|||
|
/* compute minimum size table less than or equal to l bits */
|
|||
|
z = (z = (unsigned) (g - w)) > (unsigned) l ? (unsigned) l : z; /* upper limit on table size */
|
|||
|
if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */
|
|||
|
{ /* too few codes for k-w bit table */
|
|||
|
f -= a + 1; /* deduct codes from patterns left */
|
|||
|
xp = c + k;
|
|||
|
while (++j < z) /* try smaller tables up to z bits */
|
|||
|
{
|
|||
|
if ((f <<= 1) <= *++xp)
|
|||
|
break; /* enough codes to use up j bits */
|
|||
|
f -= *xp; /* else deduct codes from patterns */
|
|||
|
}
|
|||
|
}
|
|||
|
z = 1 << j; /* table entries for j-bit table */
|
|||
|
|
|||
|
/* allocate and link in new table */
|
|||
|
q = (struct huft *) grub_zalloc ((z + 1) * sizeof (struct huft));
|
|||
|
if (! q)
|
|||
|
{
|
|||
|
if (h)
|
|||
|
huft_free (u[0]);
|
|||
|
return 3;
|
|||
|
}
|
|||
|
|
|||
|
*t = q + 1; /* link to list for huft_free() */
|
|||
|
*(t = &(q->v.t)) = (struct huft *) NULL;
|
|||
|
u[h] = ++q; /* table starts after link */
|
|||
|
|
|||
|
/* connect to last table, if there is one */
|
|||
|
if (h)
|
|||
|
{
|
|||
|
x[h] = i; /* save pattern for backing up */
|
|||
|
r.b = (uch) l; /* bits to dump before this table */
|
|||
|
r.e = (uch) (16 + j); /* bits in this table */
|
|||
|
r.v.t = q; /* pointer to this table */
|
|||
|
j = i >> (w - l); /* (get around Turbo C bug) */
|
|||
|
u[h - 1][j] = r; /* connect to last table */
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
/* set up table entry in r */
|
|||
|
r.b = (uch) (k - w);
|
|||
|
if (p >= v + n)
|
|||
|
r.e = 99; /* out of values--invalid code */
|
|||
|
else if (*p < s)
|
|||
|
{
|
|||
|
r.e = (uch) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
|
|||
|
r.v.n = (ush) (*p); /* simple code is just the value */
|
|||
|
p++; /* one compiler does not like *p++ */
|
|||
|
}
|
|||
|
else
|
|||
|
{
|
|||
|
r.e = (uch) e[*p - s]; /* non-simple--look up in lists */
|
|||
|
r.v.n = d[*p++ - s];
|
|||
|
}
|
|||
|
|
|||
|
/* fill code-like entries with r */
|
|||
|
f = 1 << (k - w);
|
|||
|
for (j = i >> w; j < z; j += f)
|
|||
|
q[j] = r;
|
|||
|
|
|||
|
/* backwards increment the k-bit code i */
|
|||
|
for (j = 1 << (k - 1); i & j; j >>= 1)
|
|||
|
i ^= j;
|
|||
|
i ^= j;
|
|||
|
|
|||
|
/* backup over finished tables */
|
|||
|
while ((i & ((1 << w) - 1)) != x[h])
|
|||
|
{
|
|||
|
h--; /* don't need to update q */
|
|||
|
w -= l;
|
|||
|
}
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
/* Return true (1) if we were given an incomplete table */
|
|||
|
return y != 0 && g != 1;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
/* Free the malloc'ed tables built by huft_build(), which makes a linked
|
|||
|
list of the tables it made, with the links in a dummy first entry of
|
|||
|
each table. */
|
|||
|
static int
|
|||
|
huft_free (struct huft *t)
|
|||
|
{
|
|||
|
register struct huft *p, *q;
|
|||
|
|
|||
|
|
|||
|
/* Go through linked list, freeing from the malloced (t[-1]) address. */
|
|||
|
p = t;
|
|||
|
while (p != (struct huft *) NULL)
|
|||
|
{
|
|||
|
q = (--p)->v.t;
|
|||
|
grub_free ((char *) p);
|
|||
|
p = q;
|
|||
|
}
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
/*
|
|||
|
* inflate (decompress) the codes in a deflated (compressed) block.
|
|||
|
* Return an error code or zero if it all goes ok.
|
|||
|
*/
|
|||
|
|
|||
|
static int
|
|||
|
inflate_codes_in_window (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
register unsigned e; /* table entry flag/number of extra bits */
|
|||
|
unsigned n, d; /* length and index for copy */
|
|||
|
unsigned w; /* current window position */
|
|||
|
struct huft *t; /* pointer to table entry */
|
|||
|
unsigned ml, md; /* masks for bl and bd bits */
|
|||
|
register ulg b; /* bit buffer */
|
|||
|
register unsigned k; /* number of bits in bit buffer */
|
|||
|
|
|||
|
/* make local copies of globals */
|
|||
|
d = gzio->inflate_d;
|
|||
|
n = gzio->inflate_n;
|
|||
|
b = gzio->bb; /* initialize bit buffer */
|
|||
|
k = gzio->bk;
|
|||
|
w = gzio->wp; /* initialize window position */
|
|||
|
|
|||
|
/* inflate the coded data */
|
|||
|
ml = mask_bits[gzio->bl]; /* precompute masks for speed */
|
|||
|
md = mask_bits[gzio->bd];
|
|||
|
for (;;) /* do until end of block */
|
|||
|
{
|
|||
|
if (! gzio->code_state)
|
|||
|
{
|
|||
|
NEEDBITS ((unsigned) gzio->bl);
|
|||
|
if ((e = (t = gzio->tl + ((unsigned) b & ml))->e) > 16)
|
|||
|
do
|
|||
|
{
|
|||
|
if (e == 99)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"an unused code found");
|
|||
|
return 1;
|
|||
|
}
|
|||
|
DUMPBITS (t->b);
|
|||
|
e -= 16;
|
|||
|
NEEDBITS (e);
|
|||
|
}
|
|||
|
while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
|
|||
|
DUMPBITS (t->b);
|
|||
|
|
|||
|
if (e == 16) /* then it's a literal */
|
|||
|
{
|
|||
|
gzio->slide[w++] = (uch) t->v.n;
|
|||
|
if (w == WSIZE)
|
|||
|
break;
|
|||
|
}
|
|||
|
else
|
|||
|
/* it's an EOB or a length */
|
|||
|
{
|
|||
|
/* exit if end of block */
|
|||
|
if (e == 15)
|
|||
|
{
|
|||
|
gzio->block_len = 0;
|
|||
|
break;
|
|||
|
}
|
|||
|
|
|||
|
/* get length of block to copy */
|
|||
|
NEEDBITS (e);
|
|||
|
n = t->v.n + ((unsigned) b & mask_bits[e]);
|
|||
|
DUMPBITS (e);
|
|||
|
|
|||
|
/* decode distance of block to copy */
|
|||
|
NEEDBITS ((unsigned) gzio->bd);
|
|||
|
if ((e = (t = gzio->td + ((unsigned) b & md))->e) > 16)
|
|||
|
do
|
|||
|
{
|
|||
|
if (e == 99)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"an unused code found");
|
|||
|
return 1;
|
|||
|
}
|
|||
|
DUMPBITS (t->b);
|
|||
|
e -= 16;
|
|||
|
NEEDBITS (e);
|
|||
|
}
|
|||
|
while ((e = (t = t->v.t + ((unsigned) b & mask_bits[e]))->e)
|
|||
|
> 16);
|
|||
|
DUMPBITS (t->b);
|
|||
|
NEEDBITS (e);
|
|||
|
d = w - t->v.n - ((unsigned) b & mask_bits[e]);
|
|||
|
DUMPBITS (e);
|
|||
|
gzio->code_state++;
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
if (gzio->code_state)
|
|||
|
{
|
|||
|
/* do the copy */
|
|||
|
do
|
|||
|
{
|
|||
|
n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n
|
|||
|
: e);
|
|||
|
|
|||
|
if (w - d >= e)
|
|||
|
{
|
|||
|
grub_memmove (gzio->slide + w, gzio->slide + d, e);
|
|||
|
w += e;
|
|||
|
d += e;
|
|||
|
}
|
|||
|
else
|
|||
|
/* purposefully use the overlap for extra copies here!! */
|
|||
|
{
|
|||
|
while (e--)
|
|||
|
gzio->slide[w++] = gzio->slide[d++];
|
|||
|
}
|
|||
|
|
|||
|
if (w == WSIZE)
|
|||
|
break;
|
|||
|
}
|
|||
|
while (n);
|
|||
|
|
|||
|
if (! n)
|
|||
|
gzio->code_state--;
|
|||
|
|
|||
|
/* did we break from the loop too soon? */
|
|||
|
if (w == WSIZE)
|
|||
|
break;
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
/* restore the globals from the locals */
|
|||
|
gzio->inflate_d = d;
|
|||
|
gzio->inflate_n = n;
|
|||
|
gzio->wp = w; /* restore global window pointer */
|
|||
|
gzio->bb = b; /* restore global bit buffer */
|
|||
|
gzio->bk = k;
|
|||
|
|
|||
|
return ! gzio->block_len;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
/* get header for an inflated type 0 (stored) block. */
|
|||
|
|
|||
|
static void
|
|||
|
init_stored_block (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
register ulg b; /* bit buffer */
|
|||
|
register unsigned k; /* number of bits in bit buffer */
|
|||
|
|
|||
|
/* make local copies of globals */
|
|||
|
b = gzio->bb; /* initialize bit buffer */
|
|||
|
k = gzio->bk;
|
|||
|
|
|||
|
/* go to byte boundary */
|
|||
|
DUMPBITS (k & 7);
|
|||
|
|
|||
|
/* get the length and its complement */
|
|||
|
NEEDBITS (16);
|
|||
|
gzio->block_len = ((unsigned) b & 0xffff);
|
|||
|
DUMPBITS (16);
|
|||
|
NEEDBITS (16);
|
|||
|
if (gzio->block_len != (int) ((~b) & 0xffff))
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"the length of a stored block does not match");
|
|||
|
DUMPBITS (16);
|
|||
|
|
|||
|
/* restore global variables */
|
|||
|
gzio->bb = b;
|
|||
|
gzio->bk = k;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
/* get header for an inflated type 1 (fixed Huffman codes) block. We should
|
|||
|
either replace this with a custom decoder, or at least precompute the
|
|||
|
Huffman tables. */
|
|||
|
|
|||
|
static void
|
|||
|
init_fixed_block (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
int i; /* temporary variable */
|
|||
|
unsigned l[288]; /* length list for huft_build */
|
|||
|
|
|||
|
/* set up literal table */
|
|||
|
for (i = 0; i < 144; i++)
|
|||
|
l[i] = 8;
|
|||
|
for (; i < 256; i++)
|
|||
|
l[i] = 9;
|
|||
|
for (; i < 280; i++)
|
|||
|
l[i] = 7;
|
|||
|
for (; i < 288; i++) /* make a complete, but wrong code set */
|
|||
|
l[i] = 8;
|
|||
|
gzio->bl = 7;
|
|||
|
if (huft_build (l, 288, 257, cplens, cplext, &gzio->tl, &gzio->bl) != 0)
|
|||
|
{
|
|||
|
if (grub_errno == GRUB_ERR_NONE)
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"failed in building a Huffman code table");
|
|||
|
return;
|
|||
|
}
|
|||
|
|
|||
|
/* set up distance table */
|
|||
|
for (i = 0; i < 30; i++) /* make an incomplete code set */
|
|||
|
l[i] = 5;
|
|||
|
gzio->bd = 5;
|
|||
|
if (huft_build (l, 30, 0, cpdist, cpdext, &gzio->td, &gzio->bd) > 1)
|
|||
|
{
|
|||
|
if (grub_errno == GRUB_ERR_NONE)
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"failed in building a Huffman code table");
|
|||
|
huft_free (gzio->tl);
|
|||
|
gzio->tl = 0;
|
|||
|
return;
|
|||
|
}
|
|||
|
|
|||
|
/* indicate we're now working on a block */
|
|||
|
gzio->code_state = 0;
|
|||
|
gzio->block_len++;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
/* get header for an inflated type 2 (dynamic Huffman codes) block. */
|
|||
|
|
|||
|
static void
|
|||
|
init_dynamic_block (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
int i; /* temporary variables */
|
|||
|
unsigned j;
|
|||
|
unsigned l; /* last length */
|
|||
|
unsigned m; /* mask for bit lengths table */
|
|||
|
unsigned n; /* number of lengths to get */
|
|||
|
unsigned nb; /* number of bit length codes */
|
|||
|
unsigned nl; /* number of literal/length codes */
|
|||
|
unsigned nd; /* number of distance codes */
|
|||
|
unsigned ll[286 + 30]; /* literal/length and distance code lengths */
|
|||
|
register ulg b; /* bit buffer */
|
|||
|
register unsigned k; /* number of bits in bit buffer */
|
|||
|
|
|||
|
/* make local bit buffer */
|
|||
|
b = gzio->bb;
|
|||
|
k = gzio->bk;
|
|||
|
|
|||
|
/* read in table lengths */
|
|||
|
NEEDBITS (5);
|
|||
|
nl = 257 + ((unsigned) b & 0x1f); /* number of literal/length codes */
|
|||
|
DUMPBITS (5);
|
|||
|
NEEDBITS (5);
|
|||
|
nd = 1 + ((unsigned) b & 0x1f); /* number of distance codes */
|
|||
|
DUMPBITS (5);
|
|||
|
NEEDBITS (4);
|
|||
|
nb = 4 + ((unsigned) b & 0xf); /* number of bit length codes */
|
|||
|
DUMPBITS (4);
|
|||
|
if (nl > 286 || nd > 30)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "too much data");
|
|||
|
return;
|
|||
|
}
|
|||
|
|
|||
|
/* read in bit-length-code lengths */
|
|||
|
for (j = 0; j < nb; j++)
|
|||
|
{
|
|||
|
NEEDBITS (3);
|
|||
|
ll[bitorder[j]] = (unsigned) b & 7;
|
|||
|
DUMPBITS (3);
|
|||
|
}
|
|||
|
for (; j < 19; j++)
|
|||
|
ll[bitorder[j]] = 0;
|
|||
|
|
|||
|
/* build decoding table for trees--single level, 7 bit lookup */
|
|||
|
gzio->bl = 7;
|
|||
|
if (huft_build (ll, 19, 19, NULL, NULL, &gzio->tl, &gzio->bl) != 0)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"failed in building a Huffman code table");
|
|||
|
return;
|
|||
|
}
|
|||
|
|
|||
|
/* read in literal and distance code lengths */
|
|||
|
n = nl + nd;
|
|||
|
m = mask_bits[gzio->bl];
|
|||
|
i = l = 0;
|
|||
|
while ((unsigned) i < n)
|
|||
|
{
|
|||
|
NEEDBITS ((unsigned) gzio->bl);
|
|||
|
j = (gzio->td = gzio->tl + ((unsigned) b & m))->b;
|
|||
|
DUMPBITS (j);
|
|||
|
j = gzio->td->v.n;
|
|||
|
if (j < 16) /* length of code in bits (0..15) */
|
|||
|
ll[i++] = l = j; /* save last length in l */
|
|||
|
else if (j == 16) /* repeat last length 3 to 6 times */
|
|||
|
{
|
|||
|
NEEDBITS (2);
|
|||
|
j = 3 + ((unsigned) b & 3);
|
|||
|
DUMPBITS (2);
|
|||
|
if ((unsigned) i + j > n)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "too many codes found");
|
|||
|
return;
|
|||
|
}
|
|||
|
while (j--)
|
|||
|
ll[i++] = l;
|
|||
|
}
|
|||
|
else if (j == 17) /* 3 to 10 zero length codes */
|
|||
|
{
|
|||
|
NEEDBITS (3);
|
|||
|
j = 3 + ((unsigned) b & 7);
|
|||
|
DUMPBITS (3);
|
|||
|
if ((unsigned) i + j > n)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "too many codes found");
|
|||
|
return;
|
|||
|
}
|
|||
|
while (j--)
|
|||
|
ll[i++] = 0;
|
|||
|
l = 0;
|
|||
|
}
|
|||
|
else
|
|||
|
/* j == 18: 11 to 138 zero length codes */
|
|||
|
{
|
|||
|
NEEDBITS (7);
|
|||
|
j = 11 + ((unsigned) b & 0x7f);
|
|||
|
DUMPBITS (7);
|
|||
|
if ((unsigned) i + j > n)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "too many codes found");
|
|||
|
return;
|
|||
|
}
|
|||
|
while (j--)
|
|||
|
ll[i++] = 0;
|
|||
|
l = 0;
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
/* free decoding table for trees */
|
|||
|
huft_free (gzio->tl);
|
|||
|
gzio->td = 0;
|
|||
|
gzio->tl = 0;
|
|||
|
|
|||
|
/* restore the global bit buffer */
|
|||
|
gzio->bb = b;
|
|||
|
gzio->bk = k;
|
|||
|
|
|||
|
/* build the decoding tables for literal/length and distance codes */
|
|||
|
gzio->bl = lbits;
|
|||
|
if (huft_build (ll, nl, 257, cplens, cplext, &gzio->tl, &gzio->bl) != 0)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"failed in building a Huffman code table");
|
|||
|
return;
|
|||
|
}
|
|||
|
gzio->bd = dbits;
|
|||
|
if (huft_build (ll + nl, nd, 0, cpdist, cpdext, &gzio->td, &gzio->bd) != 0)
|
|||
|
{
|
|||
|
huft_free (gzio->tl);
|
|||
|
gzio->tl = 0;
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"failed in building a Huffman code table");
|
|||
|
return;
|
|||
|
}
|
|||
|
|
|||
|
/* indicate we're now working on a block */
|
|||
|
gzio->code_state = 0;
|
|||
|
gzio->block_len++;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
static void
|
|||
|
get_new_block (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
register ulg b; /* bit buffer */
|
|||
|
register unsigned k; /* number of bits in bit buffer */
|
|||
|
|
|||
|
/* make local bit buffer */
|
|||
|
b = gzio->bb;
|
|||
|
k = gzio->bk;
|
|||
|
|
|||
|
/* read in last block bit */
|
|||
|
NEEDBITS (1);
|
|||
|
gzio->last_block = (int) b & 1;
|
|||
|
DUMPBITS (1);
|
|||
|
|
|||
|
/* read in block type */
|
|||
|
NEEDBITS (2);
|
|||
|
gzio->block_type = (unsigned) b & 3;
|
|||
|
DUMPBITS (2);
|
|||
|
|
|||
|
/* restore the global bit buffer */
|
|||
|
gzio->bb = b;
|
|||
|
gzio->bk = k;
|
|||
|
|
|||
|
switch (gzio->block_type)
|
|||
|
{
|
|||
|
case INFLATE_STORED:
|
|||
|
init_stored_block (gzio);
|
|||
|
break;
|
|||
|
case INFLATE_FIXED:
|
|||
|
init_fixed_block (gzio);
|
|||
|
break;
|
|||
|
case INFLATE_DYNAMIC:
|
|||
|
init_dynamic_block (gzio);
|
|||
|
break;
|
|||
|
default:
|
|||
|
break;
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
static void
|
|||
|
inflate_window (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
/* initialize window */
|
|||
|
gzio->wp = 0;
|
|||
|
|
|||
|
/*
|
|||
|
* Main decompression loop.
|
|||
|
*/
|
|||
|
|
|||
|
while (gzio->wp < WSIZE && grub_errno == GRUB_ERR_NONE)
|
|||
|
{
|
|||
|
if (! gzio->block_len)
|
|||
|
{
|
|||
|
if (gzio->last_block)
|
|||
|
break;
|
|||
|
|
|||
|
get_new_block (gzio);
|
|||
|
}
|
|||
|
|
|||
|
if (gzio->block_type > INFLATE_DYNAMIC)
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA,
|
|||
|
"unknown block type %d", gzio->block_type);
|
|||
|
|
|||
|
if (grub_errno != GRUB_ERR_NONE)
|
|||
|
return;
|
|||
|
|
|||
|
/*
|
|||
|
* Expand stored block here.
|
|||
|
*/
|
|||
|
if (gzio->block_type == INFLATE_STORED)
|
|||
|
{
|
|||
|
int w = gzio->wp;
|
|||
|
|
|||
|
/*
|
|||
|
* This is basically a glorified pass-through
|
|||
|
*/
|
|||
|
|
|||
|
while (gzio->block_len && w < WSIZE && grub_errno == GRUB_ERR_NONE)
|
|||
|
{
|
|||
|
gzio->slide[w++] = get_byte (gzio);
|
|||
|
gzio->block_len--;
|
|||
|
}
|
|||
|
|
|||
|
gzio->wp = w;
|
|||
|
|
|||
|
continue;
|
|||
|
}
|
|||
|
|
|||
|
/*
|
|||
|
* Expand other kind of block.
|
|||
|
*/
|
|||
|
|
|||
|
if (inflate_codes_in_window (gzio))
|
|||
|
{
|
|||
|
huft_free (gzio->tl);
|
|||
|
huft_free (gzio->td);
|
|||
|
gzio->tl = 0;
|
|||
|
gzio->td = 0;
|
|||
|
}
|
|||
|
}
|
|||
|
|
|||
|
gzio->saved_offset += gzio->wp;
|
|||
|
|
|||
|
/* XXX do CRC calculation here! */
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
static void
|
|||
|
initialize_tables (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
gzio->saved_offset = 0;
|
|||
|
gzio_seek (gzio, gzio->data_offset);
|
|||
|
|
|||
|
/* Initialize the bit buffer. */
|
|||
|
gzio->bk = 0;
|
|||
|
gzio->bb = 0;
|
|||
|
|
|||
|
/* Reset partial decompression code. */
|
|||
|
gzio->last_block = 0;
|
|||
|
gzio->block_len = 0;
|
|||
|
|
|||
|
/* Reset memory allocation stuff. */
|
|||
|
huft_free (gzio->tl);
|
|||
|
huft_free (gzio->td);
|
|||
|
gzio->tl = NULL;
|
|||
|
gzio->td = NULL;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
/* Open a new decompressing object on the top of IO. If TRANSPARENT is true,
|
|||
|
even if IO does not contain data compressed by gzip, return a valid file
|
|||
|
object. Note that this function won't close IO, even if an error occurs. */
|
|||
|
static grub_file_t
|
|||
|
grub_gzio_open (grub_file_t io, const char *name __attribute__ ((unused)))
|
|||
|
{
|
|||
|
grub_file_t file;
|
|||
|
grub_gzio_t gzio = 0;
|
|||
|
|
|||
|
file = (grub_file_t) grub_zalloc (sizeof (*file));
|
|||
|
if (! file)
|
|||
|
return 0;
|
|||
|
|
|||
|
gzio = grub_zalloc (sizeof (*gzio));
|
|||
|
if (! gzio)
|
|||
|
{
|
|||
|
grub_free (file);
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
gzio->file = io;
|
|||
|
|
|||
|
file->device = io->device;
|
|||
|
file->data = gzio;
|
|||
|
file->fs = &grub_gzio_fs;
|
|||
|
file->not_easily_seekable = 1;
|
|||
|
|
|||
|
if (! test_gzip_header (file))
|
|||
|
{
|
|||
|
grub_errno = GRUB_ERR_NONE;
|
|||
|
grub_free (gzio);
|
|||
|
grub_free (file);
|
|||
|
grub_file_seek (io, 0);
|
|||
|
|
|||
|
return io;
|
|||
|
}
|
|||
|
|
|||
|
return file;
|
|||
|
}
|
|||
|
|
|||
|
static int
|
|||
|
test_zlib_header (grub_gzio_t gzio)
|
|||
|
{
|
|||
|
grub_uint8_t cmf, flg;
|
|||
|
|
|||
|
cmf = get_byte (gzio);
|
|||
|
flg = get_byte (gzio);
|
|||
|
|
|||
|
/* Check that compression method is DEFLATE. */
|
|||
|
if ((cmf & 0xf) != DEFLATED)
|
|||
|
{
|
|||
|
/* TRANSLATORS: It's about given file having some strange format, not
|
|||
|
complete lack of gzip support. */
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, N_("unsupported gzip format"));
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
if ((cmf * 256U + flg) % 31U)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, N_("unsupported gzip format"));
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
/* Dictionary isn't supported. */
|
|||
|
if (flg & 0x20)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, N_("unsupported gzip format"));
|
|||
|
return 0;
|
|||
|
}
|
|||
|
|
|||
|
gzio->data_offset = 2;
|
|||
|
initialize_tables (gzio);
|
|||
|
|
|||
|
return 1;
|
|||
|
}
|
|||
|
|
|||
|
static grub_ssize_t
|
|||
|
grub_gzio_read_real (grub_gzio_t gzio, grub_off_t offset,
|
|||
|
char *buf, grub_size_t len)
|
|||
|
{
|
|||
|
grub_ssize_t ret = 0;
|
|||
|
|
|||
|
/* Do we reset decompression to the beginning of the file? */
|
|||
|
if (gzio->saved_offset > offset + WSIZE)
|
|||
|
initialize_tables (gzio);
|
|||
|
|
|||
|
/*
|
|||
|
* This loop operates upon uncompressed data only. The only
|
|||
|
* special thing it does is to make sure the decompression
|
|||
|
* window is within the range of data it needs.
|
|||
|
*/
|
|||
|
|
|||
|
while (len > 0 && grub_errno == GRUB_ERR_NONE)
|
|||
|
{
|
|||
|
register grub_size_t size;
|
|||
|
register char *srcaddr;
|
|||
|
|
|||
|
while (offset >= gzio->saved_offset)
|
|||
|
{
|
|||
|
inflate_window (gzio);
|
|||
|
if (gzio->wp == 0)
|
|||
|
goto out;
|
|||
|
}
|
|||
|
|
|||
|
if (gzio->wp == 0)
|
|||
|
goto out;
|
|||
|
|
|||
|
srcaddr = (char *) ((offset & (WSIZE - 1)) + gzio->slide);
|
|||
|
size = gzio->saved_offset - offset;
|
|||
|
if (size > len)
|
|||
|
size = len;
|
|||
|
|
|||
|
grub_memmove (buf, srcaddr, size);
|
|||
|
|
|||
|
buf += size;
|
|||
|
len -= size;
|
|||
|
ret += size;
|
|||
|
offset += size;
|
|||
|
}
|
|||
|
|
|||
|
out:
|
|||
|
if (grub_errno != GRUB_ERR_NONE)
|
|||
|
ret = -1;
|
|||
|
|
|||
|
return ret;
|
|||
|
}
|
|||
|
|
|||
|
static grub_ssize_t
|
|||
|
grub_gzio_read (grub_file_t file, char *buf, grub_size_t len)
|
|||
|
{
|
|||
|
grub_ssize_t ret;
|
|||
|
ret = grub_gzio_read_real (file->data, file->offset, buf, len);
|
|||
|
|
|||
|
if (!grub_errno && ret != (grub_ssize_t) len)
|
|||
|
{
|
|||
|
grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "premature end of compressed");
|
|||
|
ret = -1;
|
|||
|
}
|
|||
|
return ret;
|
|||
|
}
|
|||
|
|
|||
|
/* Release everything, including the underlying file object. */
|
|||
|
static grub_err_t
|
|||
|
grub_gzio_close (grub_file_t file)
|
|||
|
{
|
|||
|
grub_gzio_t gzio = file->data;
|
|||
|
|
|||
|
grub_file_close (gzio->file);
|
|||
|
huft_free (gzio->tl);
|
|||
|
huft_free (gzio->td);
|
|||
|
grub_free (gzio);
|
|||
|
|
|||
|
/* No need to close the same device twice. */
|
|||
|
file->device = 0;
|
|||
|
file->name = 0;
|
|||
|
|
|||
|
return grub_errno;
|
|||
|
}
|
|||
|
|
|||
|
grub_ssize_t
|
|||
|
grub_zlib_decompress (char *inbuf, grub_size_t insize, grub_off_t off,
|
|||
|
char *outbuf, grub_size_t outsize)
|
|||
|
{
|
|||
|
grub_gzio_t gzio = 0;
|
|||
|
grub_ssize_t ret;
|
|||
|
|
|||
|
gzio = grub_zalloc (sizeof (*gzio));
|
|||
|
if (! gzio)
|
|||
|
return -1;
|
|||
|
gzio->mem_input = (grub_uint8_t *) inbuf;
|
|||
|
gzio->mem_input_size = insize;
|
|||
|
gzio->mem_input_off = 0;
|
|||
|
|
|||
|
if (!test_zlib_header (gzio))
|
|||
|
{
|
|||
|
grub_free (gzio);
|
|||
|
return -1;
|
|||
|
}
|
|||
|
|
|||
|
ret = grub_gzio_read_real (gzio, off, outbuf, outsize);
|
|||
|
grub_free (gzio);
|
|||
|
|
|||
|
/* FIXME: Check Adler. */
|
|||
|
return ret;
|
|||
|
}
|
|||
|
|
|||
|
grub_ssize_t
|
|||
|
grub_deflate_decompress (char *inbuf, grub_size_t insize, grub_off_t off,
|
|||
|
char *outbuf, grub_size_t outsize)
|
|||
|
{
|
|||
|
grub_gzio_t gzio = 0;
|
|||
|
grub_ssize_t ret;
|
|||
|
|
|||
|
gzio = grub_zalloc (sizeof (*gzio));
|
|||
|
if (! gzio)
|
|||
|
return -1;
|
|||
|
gzio->mem_input = (grub_uint8_t *) inbuf;
|
|||
|
gzio->mem_input_size = insize;
|
|||
|
gzio->mem_input_off = 0;
|
|||
|
|
|||
|
initialize_tables (gzio);
|
|||
|
|
|||
|
ret = grub_gzio_read_real (gzio, off, outbuf, outsize);
|
|||
|
grub_free (gzio);
|
|||
|
|
|||
|
return ret;
|
|||
|
}
|
|||
|
|
|||
|
|
|||
|
|
|||
|
static struct grub_fs grub_gzio_fs =
|
|||
|
{
|
|||
|
.name = "gzio",
|
|||
|
.dir = 0,
|
|||
|
.open = 0,
|
|||
|
.read = grub_gzio_read,
|
|||
|
.close = grub_gzio_close,
|
|||
|
.label = 0,
|
|||
|
.next = 0
|
|||
|
};
|
|||
|
|
|||
|
GRUB_MOD_INIT(gzio)
|
|||
|
{
|
|||
|
grub_file_filter_register (GRUB_FILE_FILTER_GZIO, grub_gzio_open);
|
|||
|
}
|
|||
|
|
|||
|
GRUB_MOD_FINI(gzio)
|
|||
|
{
|
|||
|
grub_file_filter_unregister (GRUB_FILE_FILTER_GZIO);
|
|||
|
}
|