1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #define DEBG(x) |
3 | #define DEBG1(x) |
4 | /* inflate.c -- Not copyrighted 1992 by Mark Adler |
5 | version c10p1, 10 January 1993 */ |
6 | |
7 | /* |
8 | * Adapted for booting Linux by Hannu Savolainen 1993 |
9 | * based on gzip-1.0.3 |
10 | * |
11 | * Nicolas Pitre <nico@fluxnic.net>, 1999/04/14 : |
12 | * Little mods for all variable to reside either into rodata or bss segments |
13 | * by marking constant variables with 'const' and initializing all the others |
14 | * at run-time only. This allows for the kernel uncompressor to run |
15 | * directly from Flash or ROM memory on embedded systems. |
16 | */ |
17 | |
18 | /* |
19 | Inflate deflated (PKZIP's method 8 compressed) data. The compression |
20 | method searches for as much of the current string of bytes (up to a |
21 | length of 258) in the previous 32 K bytes. If it doesn't find any |
22 | matches (of at least length 3), it codes the next byte. Otherwise, it |
23 | codes the length of the matched string and its distance backwards from |
24 | the current position. There is a single Huffman code that codes both |
25 | single bytes (called "literals") and match lengths. A second Huffman |
26 | code codes the distance information, which follows a length code. Each |
27 | length or distance code actually represents a base value and a number |
28 | of "extra" (sometimes zero) bits to get to add to the base value. At |
29 | the end of each deflated block is a special end-of-block (EOB) literal/ |
30 | length code. The decoding process is basically: get a literal/length |
31 | code; if EOB then done; if a literal, emit the decoded byte; if a |
32 | length then get the distance and emit the referred-to bytes from the |
33 | sliding window of previously emitted data. |
34 | |
35 | There are (currently) three kinds of inflate blocks: stored, fixed, and |
36 | dynamic. The compressor deals with some chunk of data at a time, and |
37 | decides which method to use on a chunk-by-chunk basis. A chunk might |
38 | typically be 32 K or 64 K. If the chunk is incompressible, then the |
39 | "stored" method is used. In this case, the bytes are simply stored as |
40 | is, eight bits per byte, with none of the above coding. The bytes are |
41 | preceded by a count, since there is no longer an EOB code. |
42 | |
43 | If the data is compressible, then either the fixed or dynamic methods |
44 | are used. In the dynamic method, the compressed data is preceded by |
45 | an encoding of the literal/length and distance Huffman codes that are |
46 | to be used to decode this block. The representation is itself Huffman |
47 | coded, and so is preceded by a description of that code. These code |
48 | descriptions take up a little space, and so for small blocks, there is |
49 | a predefined set of codes, called the fixed codes. The fixed method is |
50 | used if the block codes up smaller that way (usually for quite small |
51 | chunks), otherwise the dynamic method is used. In the latter case, the |
52 | codes are customized to the probabilities in the current block, and so |
53 | can code it much better than the pre-determined fixed codes. |
54 | |
55 | The Huffman codes themselves are decoded using a multi-level table |
56 | lookup, in order to maximize the speed of decoding plus the speed of |
57 | building the decoding tables. See the comments below that precede the |
58 | lbits and dbits tuning parameters. |
59 | */ |
60 | |
61 | |
62 | /* |
63 | Notes beyond the 1.93a appnote.txt: |
64 | |
65 | 1. Distance pointers never point before the beginning of the output |
66 | stream. |
67 | 2. Distance pointers can point back across blocks, up to 32k away. |
68 | 3. There is an implied maximum of 7 bits for the bit length table and |
69 | 15 bits for the actual data. |
70 | 4. If only one code exists, then it is encoded using one bit. (Zero |
71 | would be more efficient, but perhaps a little confusing.) If two |
72 | codes exist, they are coded using one bit each (0 and 1). |
73 | 5. There is no way of sending zero distance codes--a dummy must be |
74 | sent if there are none. (History: a pre 2.0 version of PKZIP would |
75 | store blocks with no distance codes, but this was discovered to be |
76 | too harsh a criterion.) Valid only for 1.93a. 2.04c does allow |
77 | zero distance codes, which is sent as one code of zero bits in |
78 | length. |
79 | 6. There are up to 286 literal/length codes. Code 256 represents the |
80 | end-of-block. Note however that the static length tree defines |
81 | 288 codes just to fill out the Huffman codes. Codes 286 and 287 |
82 | cannot be used though, since there is no length base or extra bits |
83 | defined for them. Similarly, there are up to 30 distance codes. |
84 | However, static trees define 32 codes (all 5 bits) to fill out the |
85 | Huffman codes, but the last two had better not show up in the data. |
86 | 7. Unzip can check dynamic Huffman blocks for complete code sets. |
87 | The exception is that a single code would not be complete (see #4). |
88 | 8. The five bits following the block type is really the number of |
89 | literal codes sent minus 257. |
90 | 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits |
91 | (1+6+6). Therefore, to output three times the length, you output |
92 | three codes (1+1+1), whereas to output four times the same length, |
93 | you only need two codes (1+3). Hmm. |
94 | 10. In the tree reconstruction algorithm, Code = Code + Increment |
95 | only if BitLength(i) is not zero. (Pretty obvious.) |
96 | 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) |
97 | 12. Note: length code 284 can represent 227-258, but length code 285 |
98 | really is 258. The last length deserves its own, short code |
99 | since it gets used a lot in very redundant files. The length |
100 | 258 is special since 258 - 3 (the min match length) is 255. |
101 | 13. The literal/length and distance code bit lengths are read as a |
102 | single stream of lengths. It is possible (and advantageous) for |
103 | a repeat code (16, 17, or 18) to go across the boundary between |
104 | the two sets of lengths. |
105 | */ |
106 | #include <linux/compiler.h> |
107 | #ifdef NO_INFLATE_MALLOC |
108 | #include <linux/slab.h> |
109 | #endif |
110 | |
111 | #ifdef RCSID |
112 | static char rcsid[] = "#Id: inflate.c,v 0.14 1993/06/10 13:27:04 jloup Exp #" ; |
113 | #endif |
114 | |
115 | #ifndef STATIC |
116 | |
117 | #if defined(STDC_HEADERS) || defined(HAVE_STDLIB_H) |
118 | # include <sys/types.h> |
119 | # include <stdlib.h> |
120 | #endif |
121 | |
122 | #include "gzip.h" |
123 | #define STATIC |
124 | #endif /* !STATIC */ |
125 | |
126 | #ifndef INIT |
127 | #define INIT |
128 | #endif |
129 | |
130 | #define slide window |
131 | |
132 | /* Huffman code lookup table entry--this entry is four bytes for machines |
133 | that have 16-bit pointers (e.g. PC's in the small or medium model). |
134 | Valid extra bits are 0..13. e == 15 is EOB (end of block), e == 16 |
135 | means that v is a literal, 16 < e < 32 means that v is a pointer to |
136 | the next table, which codes e - 16 bits, and lastly e == 99 indicates |
137 | an unused code. If a code with e == 99 is looked up, this implies an |
138 | error in the data. */ |
139 | struct huft { |
140 | uch e; /* number of extra bits or operation */ |
141 | uch b; /* number of bits in this code or subcode */ |
142 | union { |
143 | ush n; /* literal, length base, or distance base */ |
144 | struct huft *t; /* pointer to next level of table */ |
145 | } v; |
146 | }; |
147 | |
148 | |
149 | /* Function prototypes */ |
150 | STATIC int INIT huft_build OF((unsigned *, unsigned, unsigned, |
151 | const ush *, const ush *, struct huft **, int *)); |
152 | STATIC int INIT huft_free OF((struct huft *)); |
153 | STATIC int INIT inflate_codes OF((struct huft *, struct huft *, int, int)); |
154 | STATIC int INIT inflate_stored OF((void)); |
155 | STATIC int INIT inflate_fixed OF((void)); |
156 | STATIC int INIT inflate_dynamic OF((void)); |
157 | STATIC int INIT inflate_block OF((int *)); |
158 | STATIC int INIT inflate OF((void)); |
159 | |
160 | |
161 | /* The inflate algorithm uses a sliding 32 K byte window on the uncompressed |
162 | stream to find repeated byte strings. This is implemented here as a |
163 | circular buffer. The index is updated simply by incrementing and then |
164 | ANDing with 0x7fff (32K-1). */ |
165 | /* It is left to other modules to supply the 32 K area. It is assumed |
166 | to be usable as if it were declared "uch slide[32768];" or as just |
167 | "uch *slide;" and then malloc'ed in the latter case. The definition |
168 | must be in unzip.h, included above. */ |
169 | /* unsigned wp; current position in slide */ |
170 | #define wp outcnt |
171 | #define flush_output(w) (wp=(w),flush_window()) |
172 | |
173 | /* Tables for deflate from PKZIP's appnote.txt. */ |
174 | static const unsigned border[] = { /* Order of the bit length code lengths */ |
175 | 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; |
176 | static const ush cplens[] = { /* Copy lengths for literal codes 257..285 */ |
177 | 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, |
178 | 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; |
179 | /* note: see note #13 above about the 258 in this list. */ |
180 | static const ush cplext[] = { /* Extra bits for literal codes 257..285 */ |
181 | 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, |
182 | 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */ |
183 | static const ush cpdist[] = { /* Copy offsets for distance codes 0..29 */ |
184 | 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, |
185 | 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, |
186 | 8193, 12289, 16385, 24577}; |
187 | static const ush cpdext[] = { /* Extra bits for distance codes */ |
188 | 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, |
189 | 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, |
190 | 12, 12, 13, 13}; |
191 | |
192 | |
193 | |
194 | /* Macros for inflate() bit peeking and grabbing. |
195 | The usage is: |
196 | |
197 | NEEDBITS(j) |
198 | x = b & mask_bits[j]; |
199 | DUMPBITS(j) |
200 | |
201 | where NEEDBITS makes sure that b has at least j bits in it, and |
202 | DUMPBITS removes the bits from b. The macros use the variable k |
203 | for the number of bits in b. Normally, b and k are register |
204 | variables for speed, and are initialized at the beginning of a |
205 | routine that uses these macros from a global bit buffer and count. |
206 | |
207 | If we assume that EOB will be the longest code, then we will never |
208 | ask for bits with NEEDBITS that are beyond the end of the stream. |
209 | So, NEEDBITS should not read any more bytes than are needed to |
210 | meet the request. Then no bytes need to be "returned" to the buffer |
211 | at the end of the last block. |
212 | |
213 | However, this assumption is not true for fixed blocks--the EOB code |
214 | is 7 bits, but the other literal/length codes can be 8 or 9 bits. |
215 | (The EOB code is shorter than other codes because fixed blocks are |
216 | generally short. So, while a block always has an EOB, many other |
217 | literal/length codes have a significantly lower probability of |
218 | showing up at all.) However, by making the first table have a |
219 | lookup of seven bits, the EOB code will be found in that first |
220 | lookup, and so will not require that too many bits be pulled from |
221 | the stream. |
222 | */ |
223 | |
224 | STATIC ulg bb; /* bit buffer */ |
225 | STATIC unsigned bk; /* bits in bit buffer */ |
226 | |
227 | STATIC const ush mask_bits[] = { |
228 | 0x0000, |
229 | 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, |
230 | 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff |
231 | }; |
232 | |
233 | #define NEXTBYTE() ({ int v = get_byte(); if (v < 0) goto underrun; (uch)v; }) |
234 | #define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}} |
235 | #define DUMPBITS(n) {b>>=(n);k-=(n);} |
236 | |
237 | #ifndef NO_INFLATE_MALLOC |
238 | /* A trivial malloc implementation, adapted from |
239 | * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994 |
240 | */ |
241 | |
242 | static unsigned long malloc_ptr; |
243 | static int malloc_count; |
244 | |
245 | static void *malloc(int size) |
246 | { |
247 | void *p; |
248 | |
249 | if (size < 0) |
250 | error(m: "Malloc error" ); |
251 | if (!malloc_ptr) |
252 | malloc_ptr = free_mem_ptr; |
253 | |
254 | malloc_ptr = (malloc_ptr + 3) & ~3; /* Align */ |
255 | |
256 | p = (void *)malloc_ptr; |
257 | malloc_ptr += size; |
258 | |
259 | if (free_mem_end_ptr && malloc_ptr >= free_mem_end_ptr) |
260 | error(m: "Out of memory" ); |
261 | |
262 | malloc_count++; |
263 | return p; |
264 | } |
265 | |
266 | static void free(void *where) |
267 | { |
268 | malloc_count--; |
269 | if (!malloc_count) |
270 | malloc_ptr = free_mem_ptr; |
271 | } |
272 | #else |
273 | #define malloc(a) kmalloc(a, GFP_KERNEL) |
274 | #define free(a) kfree(a) |
275 | #endif |
276 | |
277 | /* |
278 | Huffman code decoding is performed using a multi-level table lookup. |
279 | The fastest way to decode is to simply build a lookup table whose |
280 | size is determined by the longest code. However, the time it takes |
281 | to build this table can also be a factor if the data being decoded |
282 | is not very long. The most common codes are necessarily the |
283 | shortest codes, so those codes dominate the decoding time, and hence |
284 | the speed. The idea is you can have a shorter table that decodes the |
285 | shorter, more probable codes, and then point to subsidiary tables for |
286 | the longer codes. The time it costs to decode the longer codes is |
287 | then traded against the time it takes to make longer tables. |
288 | |
289 | This results of this trade are in the variables lbits and dbits |
290 | below. lbits is the number of bits the first level table for literal/ |
291 | length codes can decode in one step, and dbits is the same thing for |
292 | the distance codes. Subsequent tables are also less than or equal to |
293 | those sizes. These values may be adjusted either when all of the |
294 | codes are shorter than that, in which case the longest code length in |
295 | bits is used, or when the shortest code is *longer* than the requested |
296 | table size, in which case the length of the shortest code in bits is |
297 | used. |
298 | |
299 | There are two different values for the two tables, since they code a |
300 | different number of possibilities each. The literal/length table |
301 | codes 286 possible values, or in a flat code, a little over eight |
302 | bits. The distance table codes 30 possible values, or a little less |
303 | than five bits, flat. The optimum values for speed end up being |
304 | about one bit more than those, so lbits is 8+1 and dbits is 5+1. |
305 | The optimum values may differ though from machine to machine, and |
306 | possibly even between compilers. Your mileage may vary. |
307 | */ |
308 | |
309 | |
310 | STATIC const int lbits = 9; /* bits in base literal/length lookup table */ |
311 | STATIC const int dbits = 6; /* bits in base distance lookup table */ |
312 | |
313 | |
314 | /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */ |
315 | #define BMAX 16 /* maximum bit length of any code (16 for explode) */ |
316 | #define N_MAX 288 /* maximum number of codes in any set */ |
317 | |
318 | |
319 | STATIC unsigned hufts; /* track memory usage */ |
320 | |
321 | |
322 | STATIC int INIT huft_build( |
323 | unsigned *b, /* code lengths in bits (all assumed <= BMAX) */ |
324 | unsigned n, /* number of codes (assumed <= N_MAX) */ |
325 | unsigned s, /* number of simple-valued codes (0..s-1) */ |
326 | const ush *d, /* list of base values for non-simple codes */ |
327 | const ush *e, /* list of extra bits for non-simple codes */ |
328 | struct huft **t, /* result: starting table */ |
329 | int *m /* maximum lookup bits, returns actual */ |
330 | ) |
331 | /* Given a list of code lengths and a maximum table size, make a set of |
332 | tables to decode that set of codes. Return zero on success, one if |
333 | the given code set is incomplete (the tables are still built in this |
334 | case), two if the input is invalid (all zero length codes or an |
335 | oversubscribed set of lengths), and three if not enough memory. */ |
336 | { |
337 | unsigned a; /* counter for codes of length k */ |
338 | unsigned f; /* i repeats in table every f entries */ |
339 | int g; /* maximum code length */ |
340 | int h; /* table level */ |
341 | register unsigned i; /* counter, current code */ |
342 | register unsigned j; /* counter */ |
343 | register int k; /* number of bits in current code */ |
344 | int l; /* bits per table (returned in m) */ |
345 | register unsigned *p; /* pointer into c[], b[], or v[] */ |
346 | register struct huft *q; /* points to current table */ |
347 | struct huft r; /* table entry for structure assignment */ |
348 | register int w; /* bits before this table == (l * h) */ |
349 | unsigned *xp; /* pointer into x */ |
350 | int y; /* number of dummy codes added */ |
351 | unsigned z; /* number of entries in current table */ |
352 | struct { |
353 | unsigned c[BMAX+1]; /* bit length count table */ |
354 | struct huft *u[BMAX]; /* table stack */ |
355 | unsigned v[N_MAX]; /* values in order of bit length */ |
356 | unsigned x[BMAX+1]; /* bit offsets, then code stack */ |
357 | } *stk; |
358 | unsigned *c, *v, *x; |
359 | struct huft **u; |
360 | int ret; |
361 | |
362 | DEBG("huft1 " ); |
363 | |
364 | stk = malloc(size: sizeof(*stk)); |
365 | if (stk == NULL) |
366 | return 3; /* out of memory */ |
367 | |
368 | c = stk->c; |
369 | v = stk->v; |
370 | x = stk->x; |
371 | u = stk->u; |
372 | |
373 | /* Generate counts for each bit length */ |
374 | memzero(stk->c, sizeof(stk->c)); |
375 | p = b; i = n; |
376 | do { |
377 | Tracecv(*p, (stderr, (n-i >= ' ' && n-i <= '~' ? "%c %d\n" : "0x%x %d\n" ), |
378 | n-i, *p)); |
379 | c[*p]++; /* assume all entries <= BMAX */ |
380 | p++; /* Can't combine with above line (Solaris bug) */ |
381 | } while (--i); |
382 | if (c[0] == n) /* null input--all zero length codes */ |
383 | { |
384 | *t = (struct huft *)NULL; |
385 | *m = 0; |
386 | ret = 2; |
387 | goto out; |
388 | } |
389 | |
390 | DEBG("huft2 " ); |
391 | |
392 | /* Find minimum and maximum length, bound *m by those */ |
393 | l = *m; |
394 | for (j = 1; j <= BMAX; j++) |
395 | if (c[j]) |
396 | break; |
397 | k = j; /* minimum code length */ |
398 | if ((unsigned)l < j) |
399 | l = j; |
400 | for (i = BMAX; i; i--) |
401 | if (c[i]) |
402 | break; |
403 | g = i; /* maximum code length */ |
404 | if ((unsigned)l > i) |
405 | l = i; |
406 | *m = l; |
407 | |
408 | DEBG("huft3 " ); |
409 | |
410 | /* Adjust last length count to fill out codes, if needed */ |
411 | for (y = 1 << j; j < i; j++, y <<= 1) |
412 | if ((y -= c[j]) < 0) { |
413 | ret = 2; /* bad input: more codes than bits */ |
414 | goto out; |
415 | } |
416 | if ((y -= c[i]) < 0) { |
417 | ret = 2; |
418 | goto out; |
419 | } |
420 | c[i] += y; |
421 | |
422 | DEBG("huft4 " ); |
423 | |
424 | /* Generate starting offsets into the value table for each length */ |
425 | x[1] = j = 0; |
426 | p = c + 1; xp = x + 2; |
427 | while (--i) { /* note that i == g from above */ |
428 | *xp++ = (j += *p++); |
429 | } |
430 | |
431 | DEBG("huft5 " ); |
432 | |
433 | /* Make a table of values in order of bit lengths */ |
434 | p = b; i = 0; |
435 | do { |
436 | if ((j = *p++) != 0) |
437 | v[x[j]++] = i; |
438 | } while (++i < n); |
439 | n = x[g]; /* set n to length of v */ |
440 | |
441 | DEBG("h6 " ); |
442 | |
443 | /* Generate the Huffman codes and for each, make the table entries */ |
444 | x[0] = i = 0; /* first Huffman code is zero */ |
445 | p = v; /* grab values in bit order */ |
446 | h = -1; /* no tables yet--level -1 */ |
447 | w = -l; /* bits decoded == (l * h) */ |
448 | u[0] = (struct huft *)NULL; /* just to keep compilers happy */ |
449 | q = (struct huft *)NULL; /* ditto */ |
450 | z = 0; /* ditto */ |
451 | DEBG("h6a " ); |
452 | |
453 | /* go through the bit lengths (k already is bits in shortest code) */ |
454 | for (; k <= g; k++) |
455 | { |
456 | DEBG("h6b " ); |
457 | a = c[k]; |
458 | while (a--) |
459 | { |
460 | DEBG("h6b1 " ); |
461 | /* here i is the Huffman code of length k bits for value *p */ |
462 | /* make tables up to required level */ |
463 | while (k > w + l) |
464 | { |
465 | DEBG1("1 " ); |
466 | h++; |
467 | w += l; /* previous table always l bits */ |
468 | |
469 | /* compute minimum size table less than or equal to l bits */ |
470 | z = (z = g - w) > (unsigned)l ? l : z; /* upper limit on table size */ |
471 | if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ |
472 | { /* too few codes for k-w bit table */ |
473 | DEBG1("2 " ); |
474 | f -= a + 1; /* deduct codes from patterns left */ |
475 | xp = c + k; |
476 | if (j < z) |
477 | while (++j < z) /* try smaller tables up to z bits */ |
478 | { |
479 | if ((f <<= 1) <= *++xp) |
480 | break; /* enough codes to use up j bits */ |
481 | f -= *xp; /* else deduct codes from patterns */ |
482 | } |
483 | } |
484 | DEBG1("3 " ); |
485 | z = 1 << j; /* table entries for j-bit table */ |
486 | |
487 | /* allocate and link in new table */ |
488 | if ((q = (struct huft *)malloc(size: (z + 1)*sizeof(struct huft))) == |
489 | (struct huft *)NULL) |
490 | { |
491 | if (h) |
492 | huft_free(u[0]); |
493 | ret = 3; /* not enough memory */ |
494 | goto out; |
495 | } |
496 | DEBG1("4 " ); |
497 | hufts += z + 1; /* track memory usage */ |
498 | *t = q + 1; /* link to list for huft_free() */ |
499 | *(t = &(q->v.t)) = (struct huft *)NULL; |
500 | u[h] = ++q; /* table starts after link */ |
501 | |
502 | DEBG1("5 " ); |
503 | /* connect to last table, if there is one */ |
504 | if (h) |
505 | { |
506 | x[h] = i; /* save pattern for backing up */ |
507 | r.b = (uch)l; /* bits to dump before this table */ |
508 | r.e = (uch)(16 + j); /* bits in this table */ |
509 | r.v.t = q; /* pointer to this table */ |
510 | j = i >> (w - l); /* (get around Turbo C bug) */ |
511 | u[h-1][j] = r; /* connect to last table */ |
512 | } |
513 | DEBG1("6 " ); |
514 | } |
515 | DEBG("h6c " ); |
516 | |
517 | /* set up table entry in r */ |
518 | r.b = (uch)(k - w); |
519 | if (p >= v + n) |
520 | r.e = 99; /* out of values--invalid code */ |
521 | else if (*p < s) |
522 | { |
523 | r.e = (uch)(*p < 256 ? 16 : 15); /* 256 is end-of-block code */ |
524 | r.v.n = (ush)(*p); /* simple code is just the value */ |
525 | p++; /* one compiler does not like *p++ */ |
526 | } |
527 | else |
528 | { |
529 | r.e = (uch)e[*p - s]; /* non-simple--look up in lists */ |
530 | r.v.n = d[*p++ - s]; |
531 | } |
532 | DEBG("h6d " ); |
533 | |
534 | /* fill code-like entries with r */ |
535 | f = 1 << (k - w); |
536 | for (j = i >> w; j < z; j += f) |
537 | q[j] = r; |
538 | |
539 | /* backwards increment the k-bit code i */ |
540 | for (j = 1 << (k - 1); i & j; j >>= 1) |
541 | i ^= j; |
542 | i ^= j; |
543 | |
544 | /* backup over finished tables */ |
545 | while ((i & ((1 << w) - 1)) != x[h]) |
546 | { |
547 | h--; /* don't need to update q */ |
548 | w -= l; |
549 | } |
550 | DEBG("h6e " ); |
551 | } |
552 | DEBG("h6f " ); |
553 | } |
554 | |
555 | DEBG("huft7 " ); |
556 | |
557 | /* Return true (1) if we were given an incomplete table */ |
558 | ret = y != 0 && g != 1; |
559 | |
560 | out: |
561 | free(where: stk); |
562 | return ret; |
563 | } |
564 | |
565 | |
566 | |
567 | STATIC int INIT huft_free( |
568 | struct huft *t /* table to free */ |
569 | ) |
570 | /* Free the malloc'ed tables built by huft_build(), which makes a linked |
571 | list of the tables it made, with the links in a dummy first entry of |
572 | each table. */ |
573 | { |
574 | register struct huft *p, *q; |
575 | |
576 | |
577 | /* Go through linked list, freeing from the malloced (t[-1]) address. */ |
578 | p = t; |
579 | while (p != (struct huft *)NULL) |
580 | { |
581 | q = (--p)->v.t; |
582 | free(where: (char*)p); |
583 | p = q; |
584 | } |
585 | return 0; |
586 | } |
587 | |
588 | |
589 | STATIC int INIT inflate_codes( |
590 | struct huft *tl, /* literal/length decoder tables */ |
591 | struct huft *td, /* distance decoder tables */ |
592 | int bl, /* number of bits decoded by tl[] */ |
593 | int bd /* number of bits decoded by td[] */ |
594 | ) |
595 | /* inflate (decompress) the codes in a deflated (compressed) block. |
596 | Return an error code or zero if it all goes ok. */ |
597 | { |
598 | register unsigned e; /* table entry flag/number of extra bits */ |
599 | unsigned n, d; /* length and index for copy */ |
600 | unsigned w; /* current window position */ |
601 | struct huft *t; /* pointer to table entry */ |
602 | unsigned ml, md; /* masks for bl and bd bits */ |
603 | register ulg b; /* bit buffer */ |
604 | register unsigned k; /* number of bits in bit buffer */ |
605 | |
606 | |
607 | /* make local copies of globals */ |
608 | b = bb; /* initialize bit buffer */ |
609 | k = bk; |
610 | w = wp; /* initialize window position */ |
611 | |
612 | /* inflate the coded data */ |
613 | ml = mask_bits[bl]; /* precompute masks for speed */ |
614 | md = mask_bits[bd]; |
615 | for (;;) /* do until end of block */ |
616 | { |
617 | NEEDBITS((unsigned)bl) |
618 | if ((e = (t = tl + ((unsigned)b & ml))->e) > 16) |
619 | do { |
620 | if (e == 99) |
621 | return 1; |
622 | DUMPBITS(t->b) |
623 | e -= 16; |
624 | NEEDBITS(e) |
625 | } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16); |
626 | DUMPBITS(t->b) |
627 | if (e == 16) /* then it's a literal */ |
628 | { |
629 | slide[w++] = (uch)t->v.n; |
630 | Tracevv((stderr, "%c" , slide[w-1])); |
631 | if (w == WSIZE) |
632 | { |
633 | flush_output(w); |
634 | w = 0; |
635 | } |
636 | } |
637 | else /* it's an EOB or a length */ |
638 | { |
639 | /* exit if end of block */ |
640 | if (e == 15) |
641 | break; |
642 | |
643 | /* get length of block to copy */ |
644 | NEEDBITS(e) |
645 | n = t->v.n + ((unsigned)b & mask_bits[e]); |
646 | DUMPBITS(e); |
647 | |
648 | /* decode distance of block to copy */ |
649 | NEEDBITS((unsigned)bd) |
650 | if ((e = (t = td + ((unsigned)b & md))->e) > 16) |
651 | do { |
652 | if (e == 99) |
653 | return 1; |
654 | DUMPBITS(t->b) |
655 | e -= 16; |
656 | NEEDBITS(e) |
657 | } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16); |
658 | DUMPBITS(t->b) |
659 | NEEDBITS(e) |
660 | d = w - t->v.n - ((unsigned)b & mask_bits[e]); |
661 | DUMPBITS(e) |
662 | Tracevv((stderr,"\\[%d,%d]" , w-d, n)); |
663 | |
664 | /* do the copy */ |
665 | do { |
666 | n -= (e = (e = WSIZE - ((d &= WSIZE-1) > w ? d : w)) > n ? n : e); |
667 | #if !defined(NOMEMCPY) && !defined(DEBUG) |
668 | if (w - d >= e) /* (this test assumes unsigned comparison) */ |
669 | { |
670 | memcpy(slide + w, slide + d, e); |
671 | w += e; |
672 | d += e; |
673 | } |
674 | else /* do it slow to avoid memcpy() overlap */ |
675 | #endif /* !NOMEMCPY */ |
676 | do { |
677 | slide[w++] = slide[d++]; |
678 | Tracevv((stderr, "%c" , slide[w-1])); |
679 | } while (--e); |
680 | if (w == WSIZE) |
681 | { |
682 | flush_output(w); |
683 | w = 0; |
684 | } |
685 | } while (n); |
686 | } |
687 | } |
688 | |
689 | |
690 | /* restore the globals from the locals */ |
691 | wp = w; /* restore global window pointer */ |
692 | bb = b; /* restore global bit buffer */ |
693 | bk = k; |
694 | |
695 | /* done */ |
696 | return 0; |
697 | |
698 | underrun: |
699 | return 4; /* Input underrun */ |
700 | } |
701 | |
702 | |
703 | |
704 | STATIC int INIT inflate_stored(void) |
705 | /* "decompress" an inflated type 0 (stored) block. */ |
706 | { |
707 | unsigned n; /* number of bytes in block */ |
708 | unsigned w; /* current window position */ |
709 | register ulg b; /* bit buffer */ |
710 | register unsigned k; /* number of bits in bit buffer */ |
711 | |
712 | DEBG("<stor" ); |
713 | |
714 | /* make local copies of globals */ |
715 | b = bb; /* initialize bit buffer */ |
716 | k = bk; |
717 | w = wp; /* initialize window position */ |
718 | |
719 | |
720 | /* go to byte boundary */ |
721 | n = k & 7; |
722 | DUMPBITS(n); |
723 | |
724 | |
725 | /* get the length and its complement */ |
726 | NEEDBITS(16) |
727 | n = ((unsigned)b & 0xffff); |
728 | DUMPBITS(16) |
729 | NEEDBITS(16) |
730 | if (n != (unsigned)((~b) & 0xffff)) |
731 | return 1; /* error in compressed data */ |
732 | DUMPBITS(16) |
733 | |
734 | |
735 | /* read and output the compressed data */ |
736 | while (n--) |
737 | { |
738 | NEEDBITS(8) |
739 | slide[w++] = (uch)b; |
740 | if (w == WSIZE) |
741 | { |
742 | flush_output(w); |
743 | w = 0; |
744 | } |
745 | DUMPBITS(8) |
746 | } |
747 | |
748 | |
749 | /* restore the globals from the locals */ |
750 | wp = w; /* restore global window pointer */ |
751 | bb = b; /* restore global bit buffer */ |
752 | bk = k; |
753 | |
754 | DEBG(">" ); |
755 | return 0; |
756 | |
757 | underrun: |
758 | return 4; /* Input underrun */ |
759 | } |
760 | |
761 | |
762 | /* |
763 | * We use `noinline' here to prevent gcc-3.5 from using too much stack space |
764 | */ |
765 | STATIC int noinline INIT inflate_fixed(void) |
766 | /* decompress an inflated type 1 (fixed Huffman codes) block. We should |
767 | either replace this with a custom decoder, or at least precompute the |
768 | Huffman tables. */ |
769 | { |
770 | int i; /* temporary variable */ |
771 | struct huft *tl; /* literal/length code table */ |
772 | struct huft *td; /* distance code table */ |
773 | int bl; /* lookup bits for tl */ |
774 | int bd; /* lookup bits for td */ |
775 | unsigned *l; /* length list for huft_build */ |
776 | |
777 | DEBG("<fix" ); |
778 | |
779 | l = malloc(size: sizeof(*l) * 288); |
780 | if (l == NULL) |
781 | return 3; /* out of memory */ |
782 | |
783 | /* set up literal table */ |
784 | for (i = 0; i < 144; i++) |
785 | l[i] = 8; |
786 | for (; i < 256; i++) |
787 | l[i] = 9; |
788 | for (; i < 280; i++) |
789 | l[i] = 7; |
790 | for (; i < 288; i++) /* make a complete, but wrong code set */ |
791 | l[i] = 8; |
792 | bl = 7; |
793 | if ((i = huft_build(b: l, n: 288, s: 257, d: cplens, e: cplext, t: &tl, m: &bl)) != 0) { |
794 | free(where: l); |
795 | return i; |
796 | } |
797 | |
798 | /* set up distance table */ |
799 | for (i = 0; i < 30; i++) /* make an incomplete code set */ |
800 | l[i] = 5; |
801 | bd = 5; |
802 | if ((i = huft_build(b: l, n: 30, s: 0, d: cpdist, e: cpdext, t: &td, m: &bd)) > 1) |
803 | { |
804 | huft_free(t: tl); |
805 | free(where: l); |
806 | |
807 | DEBG(">" ); |
808 | return i; |
809 | } |
810 | |
811 | |
812 | /* decompress until an end-of-block code */ |
813 | if (inflate_codes(tl, td, bl, bd)) { |
814 | free(where: l); |
815 | return 1; |
816 | } |
817 | |
818 | /* free the decoding tables, return */ |
819 | free(where: l); |
820 | huft_free(t: tl); |
821 | huft_free(t: td); |
822 | return 0; |
823 | } |
824 | |
825 | |
826 | /* |
827 | * We use `noinline' here to prevent gcc-3.5 from using too much stack space |
828 | */ |
829 | STATIC int noinline INIT inflate_dynamic(void) |
830 | /* decompress an inflated type 2 (dynamic Huffman codes) block. */ |
831 | { |
832 | int i; /* temporary variables */ |
833 | unsigned j; |
834 | unsigned l; /* last length */ |
835 | unsigned m; /* mask for bit lengths table */ |
836 | unsigned n; /* number of lengths to get */ |
837 | struct huft *tl; /* literal/length code table */ |
838 | struct huft *td; /* distance code table */ |
839 | int bl; /* lookup bits for tl */ |
840 | int bd; /* lookup bits for td */ |
841 | unsigned nb; /* number of bit length codes */ |
842 | unsigned nl; /* number of literal/length codes */ |
843 | unsigned nd; /* number of distance codes */ |
844 | unsigned *ll; /* literal/length and distance code lengths */ |
845 | register ulg b; /* bit buffer */ |
846 | register unsigned k; /* number of bits in bit buffer */ |
847 | int ret; |
848 | |
849 | DEBG("<dyn" ); |
850 | |
851 | #ifdef PKZIP_BUG_WORKAROUND |
852 | ll = malloc(sizeof(*ll) * (288+32)); /* literal/length and distance code lengths */ |
853 | #else |
854 | ll = malloc(size: sizeof(*ll) * (286+30)); /* literal/length and distance code lengths */ |
855 | #endif |
856 | |
857 | if (ll == NULL) |
858 | return 1; |
859 | |
860 | /* make local bit buffer */ |
861 | b = bb; |
862 | k = bk; |
863 | |
864 | |
865 | /* read in table lengths */ |
866 | NEEDBITS(5) |
867 | nl = 257 + ((unsigned)b & 0x1f); /* number of literal/length codes */ |
868 | DUMPBITS(5) |
869 | NEEDBITS(5) |
870 | nd = 1 + ((unsigned)b & 0x1f); /* number of distance codes */ |
871 | DUMPBITS(5) |
872 | NEEDBITS(4) |
873 | nb = 4 + ((unsigned)b & 0xf); /* number of bit length codes */ |
874 | DUMPBITS(4) |
875 | #ifdef PKZIP_BUG_WORKAROUND |
876 | if (nl > 288 || nd > 32) |
877 | #else |
878 | if (nl > 286 || nd > 30) |
879 | #endif |
880 | { |
881 | ret = 1; /* bad lengths */ |
882 | goto out; |
883 | } |
884 | |
885 | DEBG("dyn1 " ); |
886 | |
887 | /* read in bit-length-code lengths */ |
888 | for (j = 0; j < nb; j++) |
889 | { |
890 | NEEDBITS(3) |
891 | ll[border[j]] = (unsigned)b & 7; |
892 | DUMPBITS(3) |
893 | } |
894 | for (; j < 19; j++) |
895 | ll[border[j]] = 0; |
896 | |
897 | DEBG("dyn2 " ); |
898 | |
899 | /* build decoding table for trees--single level, 7 bit lookup */ |
900 | bl = 7; |
901 | if ((i = huft_build(b: ll, n: 19, s: 19, NULL, NULL, t: &tl, m: &bl)) != 0) |
902 | { |
903 | if (i == 1) |
904 | huft_free(t: tl); |
905 | ret = i; /* incomplete code set */ |
906 | goto out; |
907 | } |
908 | |
909 | DEBG("dyn3 " ); |
910 | |
911 | /* read in literal and distance code lengths */ |
912 | n = nl + nd; |
913 | m = mask_bits[bl]; |
914 | i = l = 0; |
915 | while ((unsigned)i < n) |
916 | { |
917 | NEEDBITS((unsigned)bl) |
918 | j = (td = tl + ((unsigned)b & m))->b; |
919 | DUMPBITS(j) |
920 | j = td->v.n; |
921 | if (j < 16) /* length of code in bits (0..15) */ |
922 | ll[i++] = l = j; /* save last length in l */ |
923 | else if (j == 16) /* repeat last length 3 to 6 times */ |
924 | { |
925 | NEEDBITS(2) |
926 | j = 3 + ((unsigned)b & 3); |
927 | DUMPBITS(2) |
928 | if ((unsigned)i + j > n) { |
929 | ret = 1; |
930 | goto out; |
931 | } |
932 | while (j--) |
933 | ll[i++] = l; |
934 | } |
935 | else if (j == 17) /* 3 to 10 zero length codes */ |
936 | { |
937 | NEEDBITS(3) |
938 | j = 3 + ((unsigned)b & 7); |
939 | DUMPBITS(3) |
940 | if ((unsigned)i + j > n) { |
941 | ret = 1; |
942 | goto out; |
943 | } |
944 | while (j--) |
945 | ll[i++] = 0; |
946 | l = 0; |
947 | } |
948 | else /* j == 18: 11 to 138 zero length codes */ |
949 | { |
950 | NEEDBITS(7) |
951 | j = 11 + ((unsigned)b & 0x7f); |
952 | DUMPBITS(7) |
953 | if ((unsigned)i + j > n) { |
954 | ret = 1; |
955 | goto out; |
956 | } |
957 | while (j--) |
958 | ll[i++] = 0; |
959 | l = 0; |
960 | } |
961 | } |
962 | |
963 | DEBG("dyn4 " ); |
964 | |
965 | /* free decoding table for trees */ |
966 | huft_free(t: tl); |
967 | |
968 | DEBG("dyn5 " ); |
969 | |
970 | /* restore the global bit buffer */ |
971 | bb = b; |
972 | bk = k; |
973 | |
974 | DEBG("dyn5a " ); |
975 | |
976 | /* build the decoding tables for literal/length and distance codes */ |
977 | bl = lbits; |
978 | if ((i = huft_build(b: ll, n: nl, s: 257, d: cplens, e: cplext, t: &tl, m: &bl)) != 0) |
979 | { |
980 | DEBG("dyn5b " ); |
981 | if (i == 1) { |
982 | error(m: "incomplete literal tree" ); |
983 | huft_free(t: tl); |
984 | } |
985 | ret = i; /* incomplete code set */ |
986 | goto out; |
987 | } |
988 | DEBG("dyn5c " ); |
989 | bd = dbits; |
990 | if ((i = huft_build(b: ll + nl, n: nd, s: 0, d: cpdist, e: cpdext, t: &td, m: &bd)) != 0) |
991 | { |
992 | DEBG("dyn5d " ); |
993 | if (i == 1) { |
994 | error(m: "incomplete distance tree" ); |
995 | #ifdef PKZIP_BUG_WORKAROUND |
996 | i = 0; |
997 | } |
998 | #else |
999 | huft_free(t: td); |
1000 | } |
1001 | huft_free(t: tl); |
1002 | ret = i; /* incomplete code set */ |
1003 | goto out; |
1004 | #endif |
1005 | } |
1006 | |
1007 | DEBG("dyn6 " ); |
1008 | |
1009 | /* decompress until an end-of-block code */ |
1010 | if (inflate_codes(tl, td, bl, bd)) { |
1011 | ret = 1; |
1012 | goto out; |
1013 | } |
1014 | |
1015 | DEBG("dyn7 " ); |
1016 | |
1017 | /* free the decoding tables, return */ |
1018 | huft_free(t: tl); |
1019 | huft_free(t: td); |
1020 | |
1021 | DEBG(">" ); |
1022 | ret = 0; |
1023 | out: |
1024 | free(where: ll); |
1025 | return ret; |
1026 | |
1027 | underrun: |
1028 | ret = 4; /* Input underrun */ |
1029 | goto out; |
1030 | } |
1031 | |
1032 | |
1033 | |
1034 | STATIC int INIT inflate_block( |
1035 | int *e /* last block flag */ |
1036 | ) |
1037 | /* decompress an inflated block */ |
1038 | { |
1039 | unsigned t; /* block type */ |
1040 | register ulg b; /* bit buffer */ |
1041 | register unsigned k; /* number of bits in bit buffer */ |
1042 | |
1043 | DEBG("<blk" ); |
1044 | |
1045 | /* make local bit buffer */ |
1046 | b = bb; |
1047 | k = bk; |
1048 | |
1049 | |
1050 | /* read in last block bit */ |
1051 | NEEDBITS(1) |
1052 | *e = (int)b & 1; |
1053 | DUMPBITS(1) |
1054 | |
1055 | |
1056 | /* read in block type */ |
1057 | NEEDBITS(2) |
1058 | t = (unsigned)b & 3; |
1059 | DUMPBITS(2) |
1060 | |
1061 | |
1062 | /* restore the global bit buffer */ |
1063 | bb = b; |
1064 | bk = k; |
1065 | |
1066 | /* inflate that block type */ |
1067 | if (t == 2) |
1068 | return inflate_dynamic(); |
1069 | if (t == 0) |
1070 | return inflate_stored(); |
1071 | if (t == 1) |
1072 | return inflate_fixed(); |
1073 | |
1074 | DEBG(">" ); |
1075 | |
1076 | /* bad block type */ |
1077 | return 2; |
1078 | |
1079 | underrun: |
1080 | return 4; /* Input underrun */ |
1081 | } |
1082 | |
1083 | |
1084 | |
1085 | STATIC int INIT inflate(void) |
1086 | /* decompress an inflated entry */ |
1087 | { |
1088 | int e; /* last block flag */ |
1089 | int r; /* result code */ |
1090 | unsigned h; /* maximum struct huft's malloc'ed */ |
1091 | |
1092 | /* initialize window, bit buffer */ |
1093 | wp = 0; |
1094 | bk = 0; |
1095 | bb = 0; |
1096 | |
1097 | |
1098 | /* decompress until the last block */ |
1099 | h = 0; |
1100 | do { |
1101 | hufts = 0; |
1102 | #ifdef ARCH_HAS_DECOMP_WDOG |
1103 | arch_decomp_wdog(); |
1104 | #endif |
1105 | r = inflate_block(e: &e); |
1106 | if (r) |
1107 | return r; |
1108 | if (hufts > h) |
1109 | h = hufts; |
1110 | } while (!e); |
1111 | |
1112 | /* Undo too much lookahead. The next read will be byte aligned so we |
1113 | * can discard unused bits in the last meaningful byte. |
1114 | */ |
1115 | while (bk >= 8) { |
1116 | bk -= 8; |
1117 | inptr--; |
1118 | } |
1119 | |
1120 | /* flush out slide */ |
1121 | flush_output(wp); |
1122 | |
1123 | |
1124 | /* return success */ |
1125 | #ifdef DEBUG |
1126 | fprintf(stderr, "<%u> " , h); |
1127 | #endif /* DEBUG */ |
1128 | return 0; |
1129 | } |
1130 | |
1131 | /********************************************************************** |
1132 | * |
1133 | * The following are support routines for inflate.c |
1134 | * |
1135 | **********************************************************************/ |
1136 | |
1137 | static ulg crc_32_tab[256]; |
1138 | static ulg crc; /* initialized in makecrc() so it'll reside in bss */ |
1139 | #define CRC_VALUE (crc ^ 0xffffffffUL) |
1140 | |
1141 | /* |
1142 | * Code to compute the CRC-32 table. Borrowed from |
1143 | * gzip-1.0.3/makecrc.c. |
1144 | */ |
1145 | |
1146 | static void INIT |
1147 | makecrc(void) |
1148 | { |
1149 | /* Not copyrighted 1990 Mark Adler */ |
1150 | |
1151 | unsigned long c; /* crc shift register */ |
1152 | unsigned long e; /* polynomial exclusive-or pattern */ |
1153 | int i; /* counter for all possible eight bit values */ |
1154 | int k; /* byte being shifted into crc apparatus */ |
1155 | |
1156 | /* terms of polynomial defining this crc (except x^32): */ |
1157 | static const int p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; |
1158 | |
1159 | /* Make exclusive-or pattern from polynomial */ |
1160 | e = 0; |
1161 | for (i = 0; i < sizeof(p)/sizeof(int); i++) |
1162 | e |= 1L << (31 - p[i]); |
1163 | |
1164 | crc_32_tab[0] = 0; |
1165 | |
1166 | for (i = 1; i < 256; i++) |
1167 | { |
1168 | c = 0; |
1169 | for (k = i | 256; k != 1; k >>= 1) |
1170 | { |
1171 | c = c & 1 ? (c >> 1) ^ e : c >> 1; |
1172 | if (k & 1) |
1173 | c ^= e; |
1174 | } |
1175 | crc_32_tab[i] = c; |
1176 | } |
1177 | |
1178 | /* this is initialized here so this code could reside in ROM */ |
1179 | crc = (ulg)0xffffffffUL; /* shift register contents */ |
1180 | } |
1181 | |
1182 | /* gzip flag byte */ |
1183 | #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ |
1184 | #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ |
1185 | #define 0x04 /* bit 2 set: extra field present */ |
1186 | #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ |
1187 | #define 0x10 /* bit 4 set: file comment present */ |
1188 | #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ |
1189 | #define RESERVED 0xC0 /* bit 6,7: reserved */ |
1190 | |
1191 | /* |
1192 | * Do the uncompression! |
1193 | */ |
1194 | static int INIT gunzip(void) |
1195 | { |
1196 | uch flags; |
1197 | unsigned char magic[2]; /* magic header */ |
1198 | char method; |
1199 | ulg orig_crc = 0; /* original crc */ |
1200 | ulg orig_len = 0; /* original uncompressed length */ |
1201 | int res; |
1202 | |
1203 | magic[0] = NEXTBYTE(); |
1204 | magic[1] = NEXTBYTE(); |
1205 | method = NEXTBYTE(); |
1206 | |
1207 | if (magic[0] != 037 || |
1208 | ((magic[1] != 0213) && (magic[1] != 0236))) { |
1209 | error(m: "bad gzip magic numbers" ); |
1210 | return -1; |
1211 | } |
1212 | |
1213 | /* We only support method #8, DEFLATED */ |
1214 | if (method != 8) { |
1215 | error(m: "internal error, invalid method" ); |
1216 | return -1; |
1217 | } |
1218 | |
1219 | flags = (uch)get_byte(); |
1220 | if ((flags & ENCRYPTED) != 0) { |
1221 | error(m: "Input is encrypted" ); |
1222 | return -1; |
1223 | } |
1224 | if ((flags & CONTINUATION) != 0) { |
1225 | error(m: "Multi part input" ); |
1226 | return -1; |
1227 | } |
1228 | if ((flags & RESERVED) != 0) { |
1229 | error(m: "Input has invalid flags" ); |
1230 | return -1; |
1231 | } |
1232 | NEXTBYTE(); /* Get timestamp */ |
1233 | NEXTBYTE(); |
1234 | NEXTBYTE(); |
1235 | NEXTBYTE(); |
1236 | |
1237 | (void)NEXTBYTE(); /* Ignore extra flags for the moment */ |
1238 | (void)NEXTBYTE(); /* Ignore OS type for the moment */ |
1239 | |
1240 | if ((flags & EXTRA_FIELD) != 0) { |
1241 | unsigned len = (unsigned)NEXTBYTE(); |
1242 | len |= ((unsigned)NEXTBYTE())<<8; |
1243 | while (len--) (void)NEXTBYTE(); |
1244 | } |
1245 | |
1246 | /* Get original file name if it was truncated */ |
1247 | if ((flags & ORIG_NAME) != 0) { |
1248 | /* Discard the old name */ |
1249 | while (NEXTBYTE() != 0) /* null */ ; |
1250 | } |
1251 | |
1252 | /* Discard file comment if any */ |
1253 | if ((flags & COMMENT) != 0) { |
1254 | while (NEXTBYTE() != 0) /* null */ ; |
1255 | } |
1256 | |
1257 | /* Decompress */ |
1258 | if ((res = inflate())) { |
1259 | switch (res) { |
1260 | case 0: |
1261 | break; |
1262 | case 1: |
1263 | error(m: "invalid compressed format (err=1)" ); |
1264 | break; |
1265 | case 2: |
1266 | error(m: "invalid compressed format (err=2)" ); |
1267 | break; |
1268 | case 3: |
1269 | error(m: "out of memory" ); |
1270 | break; |
1271 | case 4: |
1272 | error(m: "out of input data" ); |
1273 | break; |
1274 | default: |
1275 | error(m: "invalid compressed format (other)" ); |
1276 | } |
1277 | return -1; |
1278 | } |
1279 | |
1280 | /* Get the crc and original length */ |
1281 | /* crc32 (see algorithm.doc) |
1282 | * uncompressed input size modulo 2^32 |
1283 | */ |
1284 | orig_crc = (ulg) NEXTBYTE(); |
1285 | orig_crc |= (ulg) NEXTBYTE() << 8; |
1286 | orig_crc |= (ulg) NEXTBYTE() << 16; |
1287 | orig_crc |= (ulg) NEXTBYTE() << 24; |
1288 | |
1289 | orig_len = (ulg) NEXTBYTE(); |
1290 | orig_len |= (ulg) NEXTBYTE() << 8; |
1291 | orig_len |= (ulg) NEXTBYTE() << 16; |
1292 | orig_len |= (ulg) NEXTBYTE() << 24; |
1293 | |
1294 | /* Validate decompression */ |
1295 | if (orig_crc != CRC_VALUE) { |
1296 | error(m: "crc error" ); |
1297 | return -1; |
1298 | } |
1299 | if (orig_len != bytes_out) { |
1300 | error(m: "length error" ); |
1301 | return -1; |
1302 | } |
1303 | return 0; |
1304 | |
1305 | underrun: /* NEXTBYTE() goto's here if needed */ |
1306 | error(m: "out of input data" ); |
1307 | return -1; |
1308 | } |
1309 | |
1310 | |
1311 | |