|
0
|
1 /* inflate.c -- zlib interface to inflate modules
|
|
|
2 * Copyright (C) 1995-1998 Mark Adler
|
|
|
3 * For conditions of distribution and use, see copyright notice in zlib.h
|
|
|
4 */
|
|
|
5
|
|
|
6 #include "zutil.h"
|
|
|
7 #include "infblock.h"
|
|
|
8
|
|
|
9 struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
|
|
|
10
|
|
|
11 typedef enum {
|
|
|
12 METHOD, /* waiting for method byte */
|
|
|
13 FLAG, /* waiting for flag byte */
|
|
|
14 DICT4, /* four dictionary check bytes to go */
|
|
|
15 DICT3, /* three dictionary check bytes to go */
|
|
|
16 DICT2, /* two dictionary check bytes to go */
|
|
|
17 DICT1, /* one dictionary check byte to go */
|
|
|
18 DICT0, /* waiting for inflateSetDictionary */
|
|
|
19 BLOCKS, /* decompressing blocks */
|
|
|
20 CHECK4, /* four check bytes to go */
|
|
|
21 CHECK3, /* three check bytes to go */
|
|
|
22 CHECK2, /* two check bytes to go */
|
|
|
23 CHECK1, /* one check byte to go */
|
|
|
24 DONE, /* finished check, done */
|
|
|
25 BAD} /* got an error--stay here */
|
|
|
26 inflate_mode;
|
|
|
27
|
|
|
28 /* inflate private state */
|
|
|
29 struct internal_state {
|
|
|
30
|
|
|
31 /* mode */
|
|
|
32 inflate_mode mode; /* current inflate mode */
|
|
|
33
|
|
|
34 /* mode dependent information */
|
|
|
35 union {
|
|
|
36 uInt method; /* if FLAGS, method byte */
|
|
|
37 struct {
|
|
|
38 uLong was; /* computed check value */
|
|
|
39 uLong need; /* stream check value */
|
|
|
40 } check; /* if CHECK, check values to compare */
|
|
|
41 uInt marker; /* if BAD, inflateSync's marker bytes count */
|
|
|
42 } sub; /* submode */
|
|
|
43
|
|
|
44 /* mode independent information */
|
|
|
45 int nowrap; /* flag for no wrapper */
|
|
|
46 uInt wbits; /* log2(window size) (8..15, defaults to 15) */
|
|
|
47 inflate_blocks_statef
|
|
|
48 *blocks; /* current inflate_blocks state */
|
|
|
49
|
|
|
50 };
|
|
|
51
|
|
|
52
|
|
|
53 int ZEXPORT inflateReset(z)
|
|
|
54 z_streamp z;
|
|
|
55 {
|
|
|
56 if (z == Z_NULL || z->state == Z_NULL)
|
|
|
57 return Z_STREAM_ERROR;
|
|
|
58 z->total_in = z->total_out = 0;
|
|
|
59 z->msg = Z_NULL;
|
|
|
60 z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
|
|
|
61 inflate_blocks_reset(z->state->blocks, z, Z_NULL);
|
|
|
62 Tracev((stderr, "inflate: reset\n"));
|
|
|
63 return Z_OK;
|
|
|
64 }
|
|
|
65
|
|
|
66
|
|
|
67 int ZEXPORT inflateEnd(z)
|
|
|
68 z_streamp z;
|
|
|
69 {
|
|
|
70 if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
|
|
|
71 return Z_STREAM_ERROR;
|
|
|
72 if (z->state->blocks != Z_NULL)
|
|
|
73 inflate_blocks_free(z->state->blocks, z);
|
|
|
74 ZFREE(z, z->state);
|
|
|
75 z->state = Z_NULL;
|
|
|
76 Tracev((stderr, "inflate: end\n"));
|
|
|
77 return Z_OK;
|
|
|
78 }
|
|
|
79
|
|
|
80
|
|
|
81 int ZEXPORT inflateInit2_(z, w, version, stream_size)
|
|
|
82 z_streamp z;
|
|
|
83 int w;
|
|
|
84 const char *version;
|
|
|
85 int stream_size;
|
|
|
86 {
|
|
|
87 if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
|
|
|
88 stream_size != sizeof(z_stream))
|
|
|
89 return Z_VERSION_ERROR;
|
|
|
90
|
|
|
91 /* initialize state */
|
|
|
92 if (z == Z_NULL)
|
|
|
93 return Z_STREAM_ERROR;
|
|
|
94 z->msg = Z_NULL;
|
|
|
95 if (z->zalloc == Z_NULL)
|
|
|
96 {
|
|
|
97 z->zalloc = zcalloc;
|
|
|
98 z->opaque = (voidpf)0;
|
|
|
99 }
|
|
|
100 if (z->zfree == Z_NULL) z->zfree = zcfree;
|
|
|
101 if ((z->state = (struct internal_state FAR *)
|
|
|
102 ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
|
|
|
103 return Z_MEM_ERROR;
|
|
|
104 z->state->blocks = Z_NULL;
|
|
|
105
|
|
|
106 /* handle undocumented nowrap option (no zlib header or check) */
|
|
|
107 z->state->nowrap = 0;
|
|
|
108 if (w < 0)
|
|
|
109 {
|
|
|
110 w = - w;
|
|
|
111 z->state->nowrap = 1;
|
|
|
112 }
|
|
|
113
|
|
|
114 /* set window size */
|
|
|
115 if (w < 8 || w > 15)
|
|
|
116 {
|
|
|
117 inflateEnd(z);
|
|
|
118 return Z_STREAM_ERROR;
|
|
|
119 }
|
|
|
120 z->state->wbits = (uInt)w;
|
|
|
121
|
|
|
122 /* create inflate_blocks state */
|
|
|
123 if ((z->state->blocks =
|
|
|
124 inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
|
|
|
125 == Z_NULL)
|
|
|
126 {
|
|
|
127 inflateEnd(z);
|
|
|
128 return Z_MEM_ERROR;
|
|
|
129 }
|
|
|
130 Tracev((stderr, "inflate: allocated\n"));
|
|
|
131
|
|
|
132 /* reset state */
|
|
|
133 inflateReset(z);
|
|
|
134 return Z_OK;
|
|
|
135 }
|
|
|
136
|
|
|
137
|
|
|
138 int ZEXPORT inflateInit_(z, version, stream_size)
|
|
|
139 z_streamp z;
|
|
|
140 const char *version;
|
|
|
141 int stream_size;
|
|
|
142 {
|
|
|
143 return inflateInit2_(z, DEF_WBITS, version, stream_size);
|
|
|
144 }
|
|
|
145
|
|
|
146
|
|
|
147 #define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
|
|
|
148 #define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
|
|
|
149
|
|
|
150 int ZEXPORT inflate(z, f)
|
|
|
151 z_streamp z;
|
|
|
152 int f;
|
|
|
153 {
|
|
|
154 int r;
|
|
|
155 uInt b;
|
|
|
156
|
|
|
157 if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
|
|
|
158 return Z_STREAM_ERROR;
|
|
|
159 f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
|
|
|
160 r = Z_BUF_ERROR;
|
|
|
161 while (1) switch (z->state->mode)
|
|
|
162 {
|
|
|
163 case METHOD:
|
|
|
164 NEEDBYTE
|
|
|
165 if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
|
|
|
166 {
|
|
|
167 z->state->mode = BAD;
|
|
|
168 z->msg = (char*)"unknown compression method";
|
|
|
169 z->state->sub.marker = 5; /* can't try inflateSync */
|
|
|
170 break;
|
|
|
171 }
|
|
|
172 if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
|
|
|
173 {
|
|
|
174 z->state->mode = BAD;
|
|
|
175 z->msg = (char*)"invalid window size";
|
|
|
176 z->state->sub.marker = 5; /* can't try inflateSync */
|
|
|
177 break;
|
|
|
178 }
|
|
|
179 z->state->mode = FLAG;
|
|
|
180 case FLAG:
|
|
|
181 NEEDBYTE
|
|
|
182 b = NEXTBYTE;
|
|
|
183 if (((z->state->sub.method << 8) + b) % 31)
|
|
|
184 {
|
|
|
185 z->state->mode = BAD;
|
|
|
186 z->msg = (char*)"incorrect header check";
|
|
|
187 z->state->sub.marker = 5; /* can't try inflateSync */
|
|
|
188 break;
|
|
|
189 }
|
|
|
190 Tracev((stderr, "inflate: zlib header ok\n"));
|
|
|
191 if (!(b & PRESET_DICT))
|
|
|
192 {
|
|
|
193 z->state->mode = BLOCKS;
|
|
|
194 break;
|
|
|
195 }
|
|
|
196 z->state->mode = DICT4;
|
|
|
197 case DICT4:
|
|
|
198 NEEDBYTE
|
|
|
199 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
|
|
|
200 z->state->mode = DICT3;
|
|
|
201 case DICT3:
|
|
|
202 NEEDBYTE
|
|
|
203 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
|
|
|
204 z->state->mode = DICT2;
|
|
|
205 case DICT2:
|
|
|
206 NEEDBYTE
|
|
|
207 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
|
|
|
208 z->state->mode = DICT1;
|
|
|
209 case DICT1:
|
|
|
210 NEEDBYTE
|
|
|
211 z->state->sub.check.need += (uLong)NEXTBYTE;
|
|
|
212 z->adler = z->state->sub.check.need;
|
|
|
213 z->state->mode = DICT0;
|
|
|
214 return Z_NEED_DICT;
|
|
|
215 case DICT0:
|
|
|
216 z->state->mode = BAD;
|
|
|
217 z->msg = (char*)"need dictionary";
|
|
|
218 z->state->sub.marker = 0; /* can try inflateSync */
|
|
|
219 return Z_STREAM_ERROR;
|
|
|
220 case BLOCKS:
|
|
|
221 r = inflate_blocks(z->state->blocks, z, r);
|
|
|
222 if (r == Z_DATA_ERROR)
|
|
|
223 {
|
|
|
224 z->state->mode = BAD;
|
|
|
225 z->state->sub.marker = 0; /* can try inflateSync */
|
|
|
226 break;
|
|
|
227 }
|
|
|
228 if (r == Z_OK)
|
|
|
229 r = f;
|
|
|
230 if (r != Z_STREAM_END)
|
|
|
231 return r;
|
|
|
232 r = f;
|
|
|
233 inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
|
|
|
234 if (z->state->nowrap)
|
|
|
235 {
|
|
|
236 z->state->mode = DONE;
|
|
|
237 break;
|
|
|
238 }
|
|
|
239 z->state->mode = CHECK4;
|
|
|
240 case CHECK4:
|
|
|
241 NEEDBYTE
|
|
|
242 z->state->sub.check.need = (uLong)NEXTBYTE << 24;
|
|
|
243 z->state->mode = CHECK3;
|
|
|
244 case CHECK3:
|
|
|
245 NEEDBYTE
|
|
|
246 z->state->sub.check.need += (uLong)NEXTBYTE << 16;
|
|
|
247 z->state->mode = CHECK2;
|
|
|
248 case CHECK2:
|
|
|
249 NEEDBYTE
|
|
|
250 z->state->sub.check.need += (uLong)NEXTBYTE << 8;
|
|
|
251 z->state->mode = CHECK1;
|
|
|
252 case CHECK1:
|
|
|
253 NEEDBYTE
|
|
|
254 z->state->sub.check.need += (uLong)NEXTBYTE;
|
|
|
255
|
|
|
256 if (z->state->sub.check.was != z->state->sub.check.need)
|
|
|
257 {
|
|
|
258 z->state->mode = BAD;
|
|
|
259 z->msg = (char*)"incorrect data check";
|
|
|
260 z->state->sub.marker = 5; /* can't try inflateSync */
|
|
|
261 break;
|
|
|
262 }
|
|
|
263 Tracev((stderr, "inflate: zlib check ok\n"));
|
|
|
264 z->state->mode = DONE;
|
|
|
265 case DONE:
|
|
|
266 return Z_STREAM_END;
|
|
|
267 case BAD:
|
|
|
268 return Z_DATA_ERROR;
|
|
|
269 default:
|
|
|
270 return Z_STREAM_ERROR;
|
|
|
271 }
|
|
|
272 #ifdef NEED_DUMMY_RETURN
|
|
|
273 return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
|
|
|
274 #endif
|
|
|
275 }
|
|
|
276
|
|
|
277
|
|
|
278 int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
|
|
|
279 z_streamp z;
|
|
|
280 const Bytef *dictionary;
|
|
|
281 uInt dictLength;
|
|
|
282 {
|
|
|
283 uInt length = dictLength;
|
|
|
284
|
|
|
285 if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
|
|
|
286 return Z_STREAM_ERROR;
|
|
|
287
|
|
|
288 if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
|
|
|
289 z->adler = 1L;
|
|
|
290
|
|
|
291 if (length >= ((uInt)1<<z->state->wbits))
|
|
|
292 {
|
|
|
293 length = (1<<z->state->wbits)-1;
|
|
|
294 dictionary += dictLength - length;
|
|
|
295 }
|
|
|
296 inflate_set_dictionary(z->state->blocks, dictionary, length);
|
|
|
297 z->state->mode = BLOCKS;
|
|
|
298 return Z_OK;
|
|
|
299 }
|
|
|
300
|
|
|
301
|
|
|
302 int ZEXPORT inflateSync(z)
|
|
|
303 z_streamp z;
|
|
|
304 {
|
|
|
305 uInt n; /* number of bytes to look at */
|
|
|
306 Bytef *p; /* pointer to bytes */
|
|
|
307 uInt m; /* number of marker bytes found in a row */
|
|
|
308 uLong r, w; /* temporaries to save total_in and total_out */
|
|
|
309
|
|
|
310 /* set up */
|
|
|
311 if (z == Z_NULL || z->state == Z_NULL)
|
|
|
312 return Z_STREAM_ERROR;
|
|
|
313 if (z->state->mode != BAD)
|
|
|
314 {
|
|
|
315 z->state->mode = BAD;
|
|
|
316 z->state->sub.marker = 0;
|
|
|
317 }
|
|
|
318 if ((n = z->avail_in) == 0)
|
|
|
319 return Z_BUF_ERROR;
|
|
|
320 p = z->next_in;
|
|
|
321 m = z->state->sub.marker;
|
|
|
322
|
|
|
323 /* search */
|
|
|
324 while (n && m < 4)
|
|
|
325 {
|
|
|
326 static const Byte mark[4] = {0, 0, 0xff, 0xff};
|
|
|
327 if (*p == mark[m])
|
|
|
328 m++;
|
|
|
329 else if (*p)
|
|
|
330 m = 0;
|
|
|
331 else
|
|
|
332 m = 4 - m;
|
|
|
333 p++, n--;
|
|
|
334 }
|
|
|
335
|
|
|
336 /* restore */
|
|
|
337 z->total_in += p - z->next_in;
|
|
|
338 z->next_in = p;
|
|
|
339 z->avail_in = n;
|
|
|
340 z->state->sub.marker = m;
|
|
|
341
|
|
|
342 /* return no joy or set up to restart on a new block */
|
|
|
343 if (m != 4)
|
|
|
344 return Z_DATA_ERROR;
|
|
|
345 r = z->total_in; w = z->total_out;
|
|
|
346 inflateReset(z);
|
|
|
347 z->total_in = r; z->total_out = w;
|
|
|
348 z->state->mode = BLOCKS;
|
|
|
349 return Z_OK;
|
|
|
350 }
|
|
|
351
|
|
|
352
|
|
|
353 /* Returns true if inflate is currently at the end of a block generated
|
|
|
354 * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
|
|
|
355 * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
|
|
|
356 * but removes the length bytes of the resulting empty stored block. When
|
|
|
357 * decompressing, PPP checks that at the end of input packet, inflate is
|
|
|
358 * waiting for these length bytes.
|
|
|
359 */
|
|
|
360 int ZEXPORT inflateSyncPoint(z)
|
|
|
361 z_streamp z;
|
|
|
362 {
|
|
|
363 if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
|
|
|
364 return Z_STREAM_ERROR;
|
|
|
365 return inflate_blocks_sync_point(z->state->blocks);
|
|
|
366 }
|
