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1310 lines
39 KiB
1310 lines
39 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#define DEBG(x) |
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#define DEBG1(x) |
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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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|
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/* |
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* Adapted for booting Linux by Hannu Savolainen 1993 |
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* based on gzip-1.0.3 |
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* |
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* Nicolas Pitre <[email protected]>, 1999/04/14 : |
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* Little mods for all variable to reside either into rodata or bss segments |
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* by marking constant variables with 'const' and initializing all the others |
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* at run-time only. This allows for the kernel uncompressor to run |
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* directly from Flash or ROM memory on embedded systems. |
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*/ |
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|
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/* |
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Inflate deflated (PKZIP's method 8 compressed) data. The compression |
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method searches for as much of the current string of bytes (up to a |
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length of 258) in the previous 32 K bytes. If it doesn't find any |
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matches (of at least length 3), it codes the next byte. Otherwise, it |
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codes the length of the matched string and its distance backwards from |
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the current position. There is a single Huffman code that codes both |
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single bytes (called "literals") and match lengths. A second Huffman |
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code codes the distance information, which follows a length code. Each |
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length or distance code actually represents a base value and a number |
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of "extra" (sometimes zero) bits to get to add to the base value. At |
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the end of each deflated block is a special end-of-block (EOB) literal/ |
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length code. The decoding process is basically: get a literal/length |
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code; if EOB then done; if a literal, emit the decoded byte; if a |
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length then get the distance and emit the referred-to bytes from the |
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sliding window of previously emitted data. |
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|
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There are (currently) three kinds of inflate blocks: stored, fixed, and |
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dynamic. The compressor deals with some chunk of data at a time, and |
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decides which method to use on a chunk-by-chunk basis. A chunk might |
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typically be 32 K or 64 K. If the chunk is incompressible, then the |
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"stored" method is used. In this case, the bytes are simply stored as |
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is, eight bits per byte, with none of the above coding. The bytes are |
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preceded by a count, since there is no longer an EOB code. |
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|
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If the data is compressible, then either the fixed or dynamic methods |
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are used. In the dynamic method, the compressed data is preceded by |
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an encoding of the literal/length and distance Huffman codes that are |
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to be used to decode this block. The representation is itself Huffman |
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coded, and so is preceded by a description of that code. These code |
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descriptions take up a little space, and so for small blocks, there is |
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a predefined set of codes, called the fixed codes. The fixed method is |
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used if the block codes up smaller that way (usually for quite small |
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chunks), otherwise the dynamic method is used. In the latter case, the |
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codes are customized to the probabilities in the current block, and so |
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can code it much better than the pre-determined fixed codes. |
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|
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The Huffman codes themselves are decoded using a multi-level table |
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lookup, in order to maximize the speed of decoding plus the speed of |
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building the decoding tables. See the comments below that precede the |
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lbits and dbits tuning parameters. |
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*/ |
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|
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|
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/* |
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Notes beyond the 1.93a appnote.txt: |
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|
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1. Distance pointers never point before the beginning of the output |
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stream. |
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2. Distance pointers can point back across blocks, up to 32k away. |
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3. There is an implied maximum of 7 bits for the bit length table and |
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15 bits for the actual data. |
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4. If only one code exists, then it is encoded using one bit. (Zero |
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would be more efficient, but perhaps a little confusing.) If two |
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codes exist, they are coded using one bit each (0 and 1). |
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5. There is no way of sending zero distance codes--a dummy must be |
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sent if there are none. (History: a pre 2.0 version of PKZIP would |
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store blocks with no distance codes, but this was discovered to be |
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too harsh a criterion.) Valid only for 1.93a. 2.04c does allow |
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zero distance codes, which is sent as one code of zero bits in |
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length. |
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6. There are up to 286 literal/length codes. Code 256 represents the |
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end-of-block. Note however that the static length tree defines |
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288 codes just to fill out the Huffman codes. Codes 286 and 287 |
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cannot be used though, since there is no length base or extra bits |
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defined for them. Similarly, there are up to 30 distance codes. |
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However, static trees define 32 codes (all 5 bits) to fill out the |
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Huffman codes, but the last two had better not show up in the data. |
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7. Unzip can check dynamic Huffman blocks for complete code sets. |
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The exception is that a single code would not be complete (see #4). |
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8. The five bits following the block type is really the number of |
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literal codes sent minus 257. |
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9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits |
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(1+6+6). Therefore, to output three times the length, you output |
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three codes (1+1+1), whereas to output four times the same length, |
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you only need two codes (1+3). Hmm. |
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10. In the tree reconstruction algorithm, Code = Code + Increment |
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only if BitLength(i) is not zero. (Pretty obvious.) |
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11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) |
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12. Note: length code 284 can represent 227-258, but length code 285 |
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really is 258. The last length deserves its own, short code |
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since it gets used a lot in very redundant files. The length |
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258 is special since 258 - 3 (the min match length) is 255. |
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13. The literal/length and distance code bit lengths are read as a |
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single stream of lengths. It is possible (and advantageous) for |
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a repeat code (16, 17, or 18) to go across the boundary between |
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the two sets of lengths. |
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*/ |
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#include <linux/compiler.h> |
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#ifdef NO_INFLATE_MALLOC |
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#include <linux/slab.h> |
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#endif |
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|
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#ifdef RCSID |
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static char rcsid[] = "#Id: inflate.c,v 0.14 1993/06/10 13:27:04 jloup Exp #"; |
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#endif |
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|
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#ifndef STATIC |
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|
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#if defined(STDC_HEADERS) || defined(HAVE_STDLIB_H) |
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# include <sys/types.h> |
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# include <stdlib.h> |
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#endif |
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|
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#include "gzip.h" |
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#define STATIC |
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#endif /* !STATIC */ |
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|
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#ifndef INIT |
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#define INIT |
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#endif |
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|
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#define slide window |
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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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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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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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} v; |
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}; |
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|
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|
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/* Function prototypes */ |
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STATIC int INIT huft_build OF((unsigned *, unsigned, unsigned, |
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const ush *, const ush *, struct huft **, int *)); |
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STATIC int INIT huft_free OF((struct huft *)); |
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STATIC int INIT inflate_codes OF((struct huft *, struct huft *, int, int)); |
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STATIC int INIT inflate_stored OF((void)); |
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STATIC int INIT inflate_fixed OF((void)); |
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STATIC int INIT inflate_dynamic OF((void)); |
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STATIC int INIT inflate_block OF((int *)); |
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STATIC int INIT inflate OF((void)); |
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|
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/* The inflate algorithm uses a sliding 32 K 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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ANDing with 0x7fff (32K-1). */ |
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/* It is left to other modules to supply the 32 K 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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/* unsigned wp; current position in slide */ |
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#define wp outcnt |
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#define flush_output(w) (wp=(w),flush_window()) |
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|
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/* Tables for deflate from PKZIP's appnote.txt. */ |
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static const unsigned border[] = { /* 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 const ush cplens[] = { /* 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 const ush cplext[] = { /* 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 const ush cpdist[] = { /* 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 const ush cpdext[] = { /* 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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|
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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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|
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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. |
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|
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However, this assumption is not true for fixed blocks--the EOB code |
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is 7 bits, but the other literal/length codes can be 8 or 9 bits. |
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(The EOB code is shorter than other codes because fixed blocks are |
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generally short. So, while a block always has an EOB, many other |
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literal/length codes have a significantly lower probability of |
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showing up at all.) However, by making the first table have a |
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lookup of seven bits, the EOB code will be found in that first |
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lookup, and so will not require that too many bits be pulled from |
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the stream. |
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*/ |
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|
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STATIC ulg bb; /* bit buffer */ |
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STATIC unsigned bk; /* bits in bit buffer */ |
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|
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STATIC const ush mask_bits[] = { |
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0x0000, |
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0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, |
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0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff |
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}; |
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|
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#define NEXTBYTE() ({ int v = get_byte(); if (v < 0) goto underrun; (uch)v; }) |
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#define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}} |
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#define DUMPBITS(n) {b>>=(n);k-=(n);} |
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|
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#ifndef NO_INFLATE_MALLOC |
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/* A trivial malloc implementation, adapted from |
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* malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994 |
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*/ |
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|
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static unsigned long malloc_ptr; |
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static int malloc_count; |
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|
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static void *malloc(int size) |
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{ |
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void *p; |
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|
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if (size < 0) |
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error("Malloc error"); |
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if (!malloc_ptr) |
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malloc_ptr = free_mem_ptr; |
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malloc_ptr = (malloc_ptr + 3) & ~3; /* Align */ |
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p = (void *)malloc_ptr; |
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malloc_ptr += size; |
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|
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if (free_mem_end_ptr && malloc_ptr >= free_mem_end_ptr) |
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error("Out of memory"); |
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|
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malloc_count++; |
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return p; |
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} |
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|
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static void free(void *where) |
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{ |
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malloc_count--; |
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if (!malloc_count) |
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malloc_ptr = free_mem_ptr; |
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} |
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#else |
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#define malloc(a) kmalloc(a, GFP_KERNEL) |
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#define free(a) kfree(a) |
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#endif |
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|
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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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|
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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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|
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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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|
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STATIC const int lbits = 9; /* bits in base literal/length lookup table */ |
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STATIC const int dbits = 6; /* bits in base distance lookup table */ |
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|
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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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STATIC unsigned hufts; /* track memory usage */ |
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|
|
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STATIC int INIT huft_build( |
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unsigned *b, /* code lengths in bits (all assumed <= BMAX) */ |
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unsigned n, /* number of codes (assumed <= N_MAX) */ |
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unsigned s, /* number of simple-valued codes (0..s-1) */ |
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const ush *d, /* list of base values for non-simple codes */ |
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const ush *e, /* list of extra bits for non-simple codes */ |
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struct huft **t, /* result: starting table */ |
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int *m /* maximum lookup bits, returns actual */ |
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) |
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/* Given a list of code lengths and a maximum table size, make a set of |
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tables to decode that set of codes. Return zero on success, one if |
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the given code set is incomplete (the tables are still built in this |
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case), two if the input is invalid (all zero length codes or an |
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oversubscribed set of lengths), and three if not enough memory. */ |
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{ |
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unsigned a; /* counter for codes of length k */ |
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unsigned f; /* i repeats in table every f entries */ |
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int g; /* maximum code length */ |
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int h; /* table level */ |
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register unsigned i; /* counter, current code */ |
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register unsigned j; /* counter */ |
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register int k; /* number of bits in current code */ |
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int l; /* bits per table (returned in m) */ |
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register unsigned *p; /* pointer into c[], b[], or v[] */ |
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register struct huft *q; /* points to current table */ |
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struct huft r; /* table entry for structure assignment */ |
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register int w; /* bits before this table == (l * h) */ |
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unsigned *xp; /* pointer into x */ |
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int y; /* number of dummy codes added */ |
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unsigned z; /* number of entries in current table */ |
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struct { |
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unsigned c[BMAX+1]; /* bit length count table */ |
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struct huft *u[BMAX]; /* table stack */ |
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unsigned v[N_MAX]; /* values in order of bit length */ |
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unsigned x[BMAX+1]; /* bit offsets, then code stack */ |
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} *stk; |
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unsigned *c, *v, *x; |
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struct huft **u; |
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int ret; |
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|
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DEBG("huft1 "); |
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|
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stk = malloc(sizeof(*stk)); |
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if (stk == NULL) |
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return 3; /* out of memory */ |
|
|
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c = stk->c; |
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v = stk->v; |
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x = stk->x; |
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u = stk->u; |
|
|
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/* Generate counts for each bit length */ |
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memzero(stk->c, sizeof(stk->c)); |
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p = b; i = n; |
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do { |
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Tracecv(*p, (stderr, (n-i >= ' ' && n-i <= '~' ? "%c %d\n" : "0x%x %d\n"), |
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n-i, *p)); |
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c[*p]++; /* assume all entries <= BMAX */ |
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p++; /* Can't combine with above line (Solaris bug) */ |
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} while (--i); |
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if (c[0] == n) /* null input--all zero length codes */ |
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{ |
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*t = (struct huft *)NULL; |
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*m = 0; |
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ret = 2; |
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goto out; |
|
} |
|
|
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DEBG("huft2 "); |
|
|
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/* Find minimum and maximum length, bound *m by those */ |
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l = *m; |
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for (j = 1; j <= BMAX; j++) |
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if (c[j]) |
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break; |
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k = j; /* minimum code length */ |
|
if ((unsigned)l < j) |
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l = j; |
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for (i = BMAX; i; i--) |
|
if (c[i]) |
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break; |
|
g = i; /* maximum code length */ |
|
if ((unsigned)l > i) |
|
l = i; |
|
*m = l; |
|
|
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DEBG("huft3 "); |
|
|
|
/* Adjust last length count to fill out codes, if needed */ |
|
for (y = 1 << j; j < i; j++, y <<= 1) |
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if ((y -= c[j]) < 0) { |
|
ret = 2; /* bad input: more codes than bits */ |
|
goto out; |
|
} |
|
if ((y -= c[i]) < 0) { |
|
ret = 2; |
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goto out; |
|
} |
|
c[i] += y; |
|
|
|
DEBG("huft4 "); |
|
|
|
/* Generate starting offsets into the value table for each length */ |
|
x[1] = j = 0; |
|
p = c + 1; xp = x + 2; |
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while (--i) { /* note that i == g from above */ |
|
*xp++ = (j += *p++); |
|
} |
|
|
|
DEBG("huft5 "); |
|
|
|
/* 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); |
|
n = x[g]; /* set n to length of v */ |
|
|
|
DEBG("h6 "); |
|
|
|
/* 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 */ |
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z = 0; /* ditto */ |
|
DEBG("h6a "); |
|
|
|
/* go through the bit lengths (k already is bits in shortest code) */ |
|
for (; k <= g; k++) |
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{ |
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DEBG("h6b "); |
|
a = c[k]; |
|
while (a--) |
|
{ |
|
DEBG("h6b1 "); |
|
/* here i is the Huffman code of length k bits for value *p */ |
|
/* make tables up to required level */ |
|
while (k > w + l) |
|
{ |
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DEBG1("1 "); |
|
h++; |
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w += l; /* previous table always l bits */ |
|
|
|
/* compute minimum size table less than or equal to l bits */ |
|
z = (z = g - w) > (unsigned)l ? 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 */ |
|
DEBG1("2 "); |
|
f -= a + 1; /* deduct codes from patterns left */ |
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xp = c + k; |
|
if (j < z) |
|
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 */ |
|
} |
|
} |
|
DEBG1("3 "); |
|
z = 1 << j; /* table entries for j-bit table */ |
|
|
|
/* allocate and link in new table */ |
|
if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) == |
|
(struct huft *)NULL) |
|
{ |
|
if (h) |
|
huft_free(u[0]); |
|
ret = 3; /* not enough memory */ |
|
goto out; |
|
} |
|
DEBG1("4 "); |
|
hufts += z + 1; /* track memory usage */ |
|
*t = q + 1; /* link to list for huft_free() */ |
|
*(t = &(q->v.t)) = (struct huft *)NULL; |
|
u[h] = ++q; /* table starts after link */ |
|
|
|
DEBG1("5 "); |
|
/* 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 */ |
|
} |
|
DEBG1("6 "); |
|
} |
|
DEBG("h6c "); |
|
|
|
/* 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]; |
|
} |
|
DEBG("h6d "); |
|
|
|
/* 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; |
|
} |
|
DEBG("h6e "); |
|
} |
|
DEBG("h6f "); |
|
} |
|
|
|
DEBG("huft7 "); |
|
|
|
/* Return true (1) if we were given an incomplete table */ |
|
ret = y != 0 && g != 1; |
|
|
|
out: |
|
free(stk); |
|
return ret; |
|
} |
|
|
|
|
|
|
|
STATIC int INIT huft_free( |
|
struct huft *t /* table to free */ |
|
) |
|
/* 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. */ |
|
{ |
|
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; |
|
free((char*)p); |
|
p = q; |
|
} |
|
return 0; |
|
} |
|
|
|
|
|
STATIC int INIT inflate_codes( |
|
struct huft *tl, /* literal/length decoder tables */ |
|
struct huft *td, /* distance decoder tables */ |
|
int bl, /* number of bits decoded by tl[] */ |
|
int bd /* number of bits decoded by td[] */ |
|
) |
|
/* inflate (decompress) the codes in a deflated (compressed) block. |
|
Return an error code or zero if it all goes ok. */ |
|
{ |
|
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 */ |
|
b = bb; /* initialize bit buffer */ |
|
k = bk; |
|
w = wp; /* initialize window position */ |
|
|
|
/* inflate the coded data */ |
|
ml = mask_bits[bl]; /* precompute masks for speed */ |
|
md = mask_bits[bd]; |
|
for (;;) /* do until end of block */ |
|
{ |
|
NEEDBITS((unsigned)bl) |
|
if ((e = (t = tl + ((unsigned)b & ml))->e) > 16) |
|
do { |
|
if (e == 99) |
|
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 */ |
|
{ |
|
slide[w++] = (uch)t->v.n; |
|
Tracevv((stderr, "%c", slide[w-1])); |
|
if (w == WSIZE) |
|
{ |
|
flush_output(w); |
|
w = 0; |
|
} |
|
} |
|
else /* it's an EOB or a length */ |
|
{ |
|
/* exit if end of block */ |
|
if (e == 15) |
|
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)bd) |
|
if ((e = (t = td + ((unsigned)b & md))->e) > 16) |
|
do { |
|
if (e == 99) |
|
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) |
|
Tracevv((stderr,"\\[%d,%d]", w-d, n)); |
|
|
|
/* do the copy */ |
|
do { |
|
n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e); |
|
#if !defined(NOMEMCPY) && !defined(DEBUG) |
|
if (w - d >= e) /* (this test assumes unsigned comparison) */ |
|
{ |
|
memcpy(slide + w, slide + d, e); |
|
w += e; |
|
d += e; |
|
} |
|
else /* do it slow to avoid memcpy() overlap */ |
|
#endif /* !NOMEMCPY */ |
|
do { |
|
slide[w++] = slide[d++]; |
|
Tracevv((stderr, "%c", slide[w-1])); |
|
} while (--e); |
|
if (w == WSIZE) |
|
{ |
|
flush_output(w); |
|
w = 0; |
|
} |
|
} while (n); |
|
} |
|
} |
|
|
|
|
|
/* restore the globals from the locals */ |
|
wp = w; /* restore global window pointer */ |
|
bb = b; /* restore global bit buffer */ |
|
bk = k; |
|
|
|
/* done */ |
|
return 0; |
|
|
|
underrun: |
|
return 4; /* Input underrun */ |
|
} |
|
|
|
|
|
|
|
STATIC int INIT inflate_stored(void) |
|
/* "decompress" an inflated type 0 (stored) block. */ |
|
{ |
|
unsigned n; /* number of bytes in block */ |
|
unsigned w; /* current window position */ |
|
register ulg b; /* bit buffer */ |
|
register unsigned k; /* number of bits in bit buffer */ |
|
|
|
DEBG("<stor"); |
|
|
|
/* make local copies of globals */ |
|
b = bb; /* initialize bit buffer */ |
|
k = bk; |
|
w = wp; /* initialize window position */ |
|
|
|
|
|
/* go to byte boundary */ |
|
n = k & 7; |
|
DUMPBITS(n); |
|
|
|
|
|
/* get the length and its complement */ |
|
NEEDBITS(16) |
|
n = ((unsigned)b & 0xffff); |
|
DUMPBITS(16) |
|
NEEDBITS(16) |
|
if (n != (unsigned)((~b) & 0xffff)) |
|
return 1; /* error in compressed data */ |
|
DUMPBITS(16) |
|
|
|
|
|
/* read and output the compressed data */ |
|
while (n--) |
|
{ |
|
NEEDBITS(8) |
|
slide[w++] = (uch)b; |
|
if (w == WSIZE) |
|
{ |
|
flush_output(w); |
|
w = 0; |
|
} |
|
DUMPBITS(8) |
|
} |
|
|
|
|
|
/* restore the globals from the locals */ |
|
wp = w; /* restore global window pointer */ |
|
bb = b; /* restore global bit buffer */ |
|
bk = k; |
|
|
|
DEBG(">"); |
|
return 0; |
|
|
|
underrun: |
|
return 4; /* Input underrun */ |
|
} |
|
|
|
|
|
/* |
|
* We use `noinline' here to prevent gcc-3.5 from using too much stack space |
|
*/ |
|
STATIC int noinline INIT inflate_fixed(void) |
|
/* decompress an inflated type 1 (fixed Huffman codes) block. We should |
|
either replace this with a custom decoder, or at least precompute the |
|
Huffman tables. */ |
|
{ |
|
int i; /* temporary variable */ |
|
struct huft *tl; /* literal/length code table */ |
|
struct huft *td; /* distance code table */ |
|
int bl; /* lookup bits for tl */ |
|
int bd; /* lookup bits for td */ |
|
unsigned *l; /* length list for huft_build */ |
|
|
|
DEBG("<fix"); |
|
|
|
l = malloc(sizeof(*l) * 288); |
|
if (l == NULL) |
|
return 3; /* out of memory */ |
|
|
|
/* 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; |
|
bl = 7; |
|
if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) { |
|
free(l); |
|
return i; |
|
} |
|
|
|
/* set up distance table */ |
|
for (i = 0; i < 30; i++) /* make an incomplete code set */ |
|
l[i] = 5; |
|
bd = 5; |
|
if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) |
|
{ |
|
huft_free(tl); |
|
free(l); |
|
|
|
DEBG(">"); |
|
return i; |
|
} |
|
|
|
|
|
/* decompress until an end-of-block code */ |
|
if (inflate_codes(tl, td, bl, bd)) { |
|
free(l); |
|
return 1; |
|
} |
|
|
|
/* free the decoding tables, return */ |
|
free(l); |
|
huft_free(tl); |
|
huft_free(td); |
|
return 0; |
|
} |
|
|
|
|
|
/* |
|
* We use `noinline' here to prevent gcc-3.5 from using too much stack space |
|
*/ |
|
STATIC int noinline INIT inflate_dynamic(void) |
|
/* decompress an inflated type 2 (dynamic Huffman codes) block. */ |
|
{ |
|
int i; /* temporary variables */ |
|
unsigned j; |
|
unsigned l; /* last length */ |
|
unsigned m; /* mask for bit lengths table */ |
|
unsigned n; /* number of lengths to get */ |
|
struct huft *tl; /* literal/length code table */ |
|
struct huft *td; /* distance code table */ |
|
int bl; /* lookup bits for tl */ |
|
int bd; /* lookup bits for td */ |
|
unsigned nb; /* number of bit length codes */ |
|
unsigned nl; /* number of literal/length codes */ |
|
unsigned nd; /* number of distance codes */ |
|
unsigned *ll; /* literal/length and distance code lengths */ |
|
register ulg b; /* bit buffer */ |
|
register unsigned k; /* number of bits in bit buffer */ |
|
int ret; |
|
|
|
DEBG("<dyn"); |
|
|
|
#ifdef PKZIP_BUG_WORKAROUND |
|
ll = malloc(sizeof(*ll) * (288+32)); /* literal/length and distance code lengths */ |
|
#else |
|
ll = malloc(sizeof(*ll) * (286+30)); /* literal/length and distance code lengths */ |
|
#endif |
|
|
|
if (ll == NULL) |
|
return 1; |
|
|
|
/* make local bit buffer */ |
|
b = bb; |
|
k = 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) |
|
#ifdef PKZIP_BUG_WORKAROUND |
|
if (nl > 288 || nd > 32) |
|
#else |
|
if (nl > 286 || nd > 30) |
|
#endif |
|
{ |
|
ret = 1; /* bad lengths */ |
|
goto out; |
|
} |
|
|
|
DEBG("dyn1 "); |
|
|
|
/* read in bit-length-code lengths */ |
|
for (j = 0; j < nb; j++) |
|
{ |
|
NEEDBITS(3) |
|
ll[border[j]] = (unsigned)b & 7; |
|
DUMPBITS(3) |
|
} |
|
for (; j < 19; j++) |
|
ll[border[j]] = 0; |
|
|
|
DEBG("dyn2 "); |
|
|
|
/* build decoding table for trees--single level, 7 bit lookup */ |
|
bl = 7; |
|
if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0) |
|
{ |
|
if (i == 1) |
|
huft_free(tl); |
|
ret = i; /* incomplete code set */ |
|
goto out; |
|
} |
|
|
|
DEBG("dyn3 "); |
|
|
|
/* read in literal and distance code lengths */ |
|
n = nl + nd; |
|
m = mask_bits[bl]; |
|
i = l = 0; |
|
while ((unsigned)i < n) |
|
{ |
|
NEEDBITS((unsigned)bl) |
|
j = (td = tl + ((unsigned)b & m))->b; |
|
DUMPBITS(j) |
|
j = 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) { |
|
ret = 1; |
|
goto out; |
|
} |
|
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) { |
|
ret = 1; |
|
goto out; |
|
} |
|
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) { |
|
ret = 1; |
|
goto out; |
|
} |
|
while (j--) |
|
ll[i++] = 0; |
|
l = 0; |
|
} |
|
} |
|
|
|
DEBG("dyn4 "); |
|
|
|
/* free decoding table for trees */ |
|
huft_free(tl); |
|
|
|
DEBG("dyn5 "); |
|
|
|
/* restore the global bit buffer */ |
|
bb = b; |
|
bk = k; |
|
|
|
DEBG("dyn5a "); |
|
|
|
/* build the decoding tables for literal/length and distance codes */ |
|
bl = lbits; |
|
if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) |
|
{ |
|
DEBG("dyn5b "); |
|
if (i == 1) { |
|
error("incomplete literal tree"); |
|
huft_free(tl); |
|
} |
|
ret = i; /* incomplete code set */ |
|
goto out; |
|
} |
|
DEBG("dyn5c "); |
|
bd = dbits; |
|
if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) |
|
{ |
|
DEBG("dyn5d "); |
|
if (i == 1) { |
|
error("incomplete distance tree"); |
|
#ifdef PKZIP_BUG_WORKAROUND |
|
i = 0; |
|
} |
|
#else |
|
huft_free(td); |
|
} |
|
huft_free(tl); |
|
ret = i; /* incomplete code set */ |
|
goto out; |
|
#endif |
|
} |
|
|
|
DEBG("dyn6 "); |
|
|
|
/* decompress until an end-of-block code */ |
|
if (inflate_codes(tl, td, bl, bd)) { |
|
ret = 1; |
|
goto out; |
|
} |
|
|
|
DEBG("dyn7 "); |
|
|
|
/* free the decoding tables, return */ |
|
huft_free(tl); |
|
huft_free(td); |
|
|
|
DEBG(">"); |
|
ret = 0; |
|
out: |
|
free(ll); |
|
return ret; |
|
|
|
underrun: |
|
ret = 4; /* Input underrun */ |
|
goto out; |
|
} |
|
|
|
|
|
|
|
STATIC int INIT inflate_block( |
|
int *e /* last block flag */ |
|
) |
|
/* decompress an inflated block */ |
|
{ |
|
unsigned t; /* block type */ |
|
register ulg b; /* bit buffer */ |
|
register unsigned k; /* number of bits in bit buffer */ |
|
|
|
DEBG("<blk"); |
|
|
|
/* make local bit buffer */ |
|
b = bb; |
|
k = bk; |
|
|
|
|
|
/* read in last block bit */ |
|
NEEDBITS(1) |
|
*e = (int)b & 1; |
|
DUMPBITS(1) |
|
|
|
|
|
/* read in block type */ |
|
NEEDBITS(2) |
|
t = (unsigned)b & 3; |
|
DUMPBITS(2) |
|
|
|
|
|
/* restore the global bit buffer */ |
|
bb = b; |
|
bk = k; |
|
|
|
/* inflate that block type */ |
|
if (t == 2) |
|
return inflate_dynamic(); |
|
if (t == 0) |
|
return inflate_stored(); |
|
if (t == 1) |
|
return inflate_fixed(); |
|
|
|
DEBG(">"); |
|
|
|
/* bad block type */ |
|
return 2; |
|
|
|
underrun: |
|
return 4; /* Input underrun */ |
|
} |
|
|
|
|
|
|
|
STATIC int INIT inflate(void) |
|
/* decompress an inflated entry */ |
|
{ |
|
int e; /* last block flag */ |
|
int r; /* result code */ |
|
unsigned h; /* maximum struct huft's malloc'ed */ |
|
|
|
/* initialize window, bit buffer */ |
|
wp = 0; |
|
bk = 0; |
|
bb = 0; |
|
|
|
|
|
/* decompress until the last block */ |
|
h = 0; |
|
do { |
|
hufts = 0; |
|
#ifdef ARCH_HAS_DECOMP_WDOG |
|
arch_decomp_wdog(); |
|
#endif |
|
r = inflate_block(&e); |
|
if (r) |
|
return r; |
|
if (hufts > h) |
|
h = hufts; |
|
} while (!e); |
|
|
|
/* Undo too much lookahead. The next read will be byte aligned so we |
|
* can discard unused bits in the last meaningful byte. |
|
*/ |
|
while (bk >= 8) { |
|
bk -= 8; |
|
inptr--; |
|
} |
|
|
|
/* flush out slide */ |
|
flush_output(wp); |
|
|
|
|
|
/* return success */ |
|
#ifdef DEBUG |
|
fprintf(stderr, "<%u> ", h); |
|
#endif /* DEBUG */ |
|
return 0; |
|
} |
|
|
|
/********************************************************************** |
|
* |
|
* The following are support routines for inflate.c |
|
* |
|
**********************************************************************/ |
|
|
|
static ulg crc_32_tab[256]; |
|
static ulg crc; /* initialized in makecrc() so it'll reside in bss */ |
|
#define CRC_VALUE (crc ^ 0xffffffffUL) |
|
|
|
/* |
|
* Code to compute the CRC-32 table. Borrowed from |
|
* gzip-1.0.3/makecrc.c. |
|
*/ |
|
|
|
static void INIT |
|
makecrc(void) |
|
{ |
|
/* Not copyrighted 1990 Mark Adler */ |
|
|
|
unsigned long c; /* crc shift register */ |
|
unsigned long e; /* polynomial exclusive-or pattern */ |
|
int i; /* counter for all possible eight bit values */ |
|
int k; /* byte being shifted into crc apparatus */ |
|
|
|
/* terms of polynomial defining this crc (except x^32): */ |
|
static const int p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; |
|
|
|
/* Make exclusive-or pattern from polynomial */ |
|
e = 0; |
|
for (i = 0; i < sizeof(p)/sizeof(int); i++) |
|
e |= 1L << (31 - p[i]); |
|
|
|
crc_32_tab[0] = 0; |
|
|
|
for (i = 1; i < 256; i++) |
|
{ |
|
c = 0; |
|
for (k = i | 256; k != 1; k >>= 1) |
|
{ |
|
c = c & 1 ? (c >> 1) ^ e : c >> 1; |
|
if (k & 1) |
|
c ^= e; |
|
} |
|
crc_32_tab[i] = c; |
|
} |
|
|
|
/* this is initialized here so this code could reside in ROM */ |
|
crc = (ulg)0xffffffffUL; /* shift register contents */ |
|
} |
|
|
|
/* gzip flag byte */ |
|
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ |
|
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ |
|
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ |
|
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ |
|
#define COMMENT 0x10 /* bit 4 set: file comment present */ |
|
#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ |
|
#define RESERVED 0xC0 /* bit 6,7: reserved */ |
|
|
|
/* |
|
* Do the uncompression! |
|
*/ |
|
static int INIT gunzip(void) |
|
{ |
|
uch flags; |
|
unsigned char magic[2]; /* magic header */ |
|
char method; |
|
ulg orig_crc = 0; /* original crc */ |
|
ulg orig_len = 0; /* original uncompressed length */ |
|
int res; |
|
|
|
magic[0] = NEXTBYTE(); |
|
magic[1] = NEXTBYTE(); |
|
method = NEXTBYTE(); |
|
|
|
if (magic[0] != 037 || |
|
((magic[1] != 0213) && (magic[1] != 0236))) { |
|
error("bad gzip magic numbers"); |
|
return -1; |
|
} |
|
|
|
/* We only support method #8, DEFLATED */ |
|
if (method != 8) { |
|
error("internal error, invalid method"); |
|
return -1; |
|
} |
|
|
|
flags = (uch)get_byte(); |
|
if ((flags & ENCRYPTED) != 0) { |
|
error("Input is encrypted"); |
|
return -1; |
|
} |
|
if ((flags & CONTINUATION) != 0) { |
|
error("Multi part input"); |
|
return -1; |
|
} |
|
if ((flags & RESERVED) != 0) { |
|
error("Input has invalid flags"); |
|
return -1; |
|
} |
|
NEXTBYTE(); /* Get timestamp */ |
|
NEXTBYTE(); |
|
NEXTBYTE(); |
|
NEXTBYTE(); |
|
|
|
(void)NEXTBYTE(); /* Ignore extra flags for the moment */ |
|
(void)NEXTBYTE(); /* Ignore OS type for the moment */ |
|
|
|
if ((flags & EXTRA_FIELD) != 0) { |
|
unsigned len = (unsigned)NEXTBYTE(); |
|
len |= ((unsigned)NEXTBYTE())<<8; |
|
while (len--) (void)NEXTBYTE(); |
|
} |
|
|
|
/* Get original file name if it was truncated */ |
|
if ((flags & ORIG_NAME) != 0) { |
|
/* Discard the old name */ |
|
while (NEXTBYTE() != 0) /* null */ ; |
|
} |
|
|
|
/* Discard file comment if any */ |
|
if ((flags & COMMENT) != 0) { |
|
while (NEXTBYTE() != 0) /* null */ ; |
|
} |
|
|
|
/* Decompress */ |
|
if ((res = inflate())) { |
|
switch (res) { |
|
case 0: |
|
break; |
|
case 1: |
|
error("invalid compressed format (err=1)"); |
|
break; |
|
case 2: |
|
error("invalid compressed format (err=2)"); |
|
break; |
|
case 3: |
|
error("out of memory"); |
|
break; |
|
case 4: |
|
error("out of input data"); |
|
break; |
|
default: |
|
error("invalid compressed format (other)"); |
|
} |
|
return -1; |
|
} |
|
|
|
/* Get the crc and original length */ |
|
/* crc32 (see algorithm.doc) |
|
* uncompressed input size modulo 2^32 |
|
*/ |
|
orig_crc = (ulg) NEXTBYTE(); |
|
orig_crc |= (ulg) NEXTBYTE() << 8; |
|
orig_crc |= (ulg) NEXTBYTE() << 16; |
|
orig_crc |= (ulg) NEXTBYTE() << 24; |
|
|
|
orig_len = (ulg) NEXTBYTE(); |
|
orig_len |= (ulg) NEXTBYTE() << 8; |
|
orig_len |= (ulg) NEXTBYTE() << 16; |
|
orig_len |= (ulg) NEXTBYTE() << 24; |
|
|
|
/* Validate decompression */ |
|
if (orig_crc != CRC_VALUE) { |
|
error("crc error"); |
|
return -1; |
|
} |
|
if (orig_len != bytes_out) { |
|
error("length error"); |
|
return -1; |
|
} |
|
return 0; |
|
|
|
underrun: /* NEXTBYTE() goto's here if needed */ |
|
error("out of input data"); |
|
return -1; |
|
} |
|
|
|
|
|
|