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-rw-r--r--archival/libunarchive/decompress_bunzip2.c163
1 files changed, 145 insertions, 18 deletions
diff --git a/archival/libunarchive/decompress_bunzip2.c b/archival/libunarchive/decompress_bunzip2.c
index af3731b15..8694a32cd 100644
--- a/archival/libunarchive/decompress_bunzip2.c
+++ b/archival/libunarchive/decompress_bunzip2.c
@@ -7,7 +7,7 @@
7 Robert Sedgewick, and Jon L. Bentley. 7 Robert Sedgewick, and Jon L. Bentley.
8 8
9 This code is licensed under the LGPLv2: 9 This code is licensed under the LGPLv2:
10 LGPL (http://www.gnu.org/copyleft/lgpl.html 10 LGPL http://www.gnu.org/copyleft/lgpl.html
11*/ 11*/
12 12
13/* 13/*
@@ -23,19 +23,8 @@
23 23
24 I would ask that anyone benefiting from this work, especially those 24 I would ask that anyone benefiting from this work, especially those
25 using it in commercial products, consider making a donation to my local 25 using it in commercial products, consider making a donation to my local
26 non-profit hospice organization in the name of the woman I loved, who 26 non-profit hospice organization (www.hospiceacadiana.com) in the name of
27 passed away Feb. 12, 2003. 27 the woman I loved, Toni W. Hagan, who passed away Feb. 12, 2003.
28
29 In memory of Toni W. Hagan
30
31 Hospice of Acadiana, Inc.
32 2600 Johnston St., Suite 200
33 Lafayette, LA 70503-3240
34
35 Phone (337) 232-1234 or 1-800-738-2226
36 Fax (337) 232-1297
37
38 http://www.hospiceacadiana.com/
39 28
40 Manuel 29 Manuel
41 */ 30 */
@@ -79,51 +68,73 @@ struct group_data {
79 68
80/* Structure holding all the housekeeping data, including IO buffers and 69/* Structure holding all the housekeeping data, including IO buffers and
81 memory that persists between calls to bunzip */ 70 memory that persists between calls to bunzip */
71
82typedef struct { 72typedef struct {
83 /* State for interrupting output loop */ 73 /* State for interrupting output loop */
74
84 int writeCopies,writePos,writeRunCountdown,writeCount,writeCurrent; 75 int writeCopies,writePos,writeRunCountdown,writeCount,writeCurrent;
76
85 /* I/O tracking data (file handles, buffers, positions, etc.) */ 77 /* I/O tracking data (file handles, buffers, positions, etc.) */
78
86 int in_fd,out_fd,inbufCount,inbufPos /*,outbufPos*/; 79 int in_fd,out_fd,inbufCount,inbufPos /*,outbufPos*/;
87 unsigned char *inbuf /*,*outbuf*/; 80 unsigned char *inbuf /*,*outbuf*/;
88 unsigned int inbufBitCount, inbufBits; 81 unsigned int inbufBitCount, inbufBits;
82
89 /* The CRC values stored in the block header and calculated from the data */ 83 /* The CRC values stored in the block header and calculated from the data */
84
90 unsigned int crc32Table[256],headerCRC, totalCRC, writeCRC; 85 unsigned int crc32Table[256],headerCRC, totalCRC, writeCRC;
86
91 /* Intermediate buffer and its size (in bytes) */ 87 /* Intermediate buffer and its size (in bytes) */
88
92 unsigned int *dbuf, dbufSize; 89 unsigned int *dbuf, dbufSize;
90
93 /* These things are a bit too big to go on the stack */ 91 /* These things are a bit too big to go on the stack */
92
94 unsigned char selectors[32768]; /* nSelectors=15 bits */ 93 unsigned char selectors[32768]; /* nSelectors=15 bits */
95 struct group_data groups[MAX_GROUPS]; /* Huffman coding tables */ 94 struct group_data groups[MAX_GROUPS]; /* Huffman coding tables */
95
96 /* For I/O error handling */ 96 /* For I/O error handling */
97
97 jmp_buf jmpbuf; 98 jmp_buf jmpbuf;
98} bunzip_data; 99} bunzip_data;
99 100
100/* Return the next nnn bits of input. All reads from the compressed input 101/* Return the next nnn bits of input. All reads from the compressed input
101 are done through this function. All reads are big endian */ 102 are done through this function. All reads are big endian */
103
102static unsigned int get_bits(bunzip_data *bd, char bits_wanted) 104static unsigned int get_bits(bunzip_data *bd, char bits_wanted)
103{ 105{
104 unsigned int bits=0; 106 unsigned int bits=0;
105 107
106 /* If we need to get more data from the byte buffer, do so. (Loop getting 108 /* If we need to get more data from the byte buffer, do so. (Loop getting
107 one byte at a time to enforce endianness and avoid unaligned access.) */ 109 one byte at a time to enforce endianness and avoid unaligned access.) */
110
108 while (bd->inbufBitCount<bits_wanted) { 111 while (bd->inbufBitCount<bits_wanted) {
112
109 /* If we need to read more data from file into byte buffer, do so */ 113 /* If we need to read more data from file into byte buffer, do so */
114
110 if(bd->inbufPos==bd->inbufCount) { 115 if(bd->inbufPos==bd->inbufCount) {
111 if((bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE)) <= 0) 116 if((bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE)) <= 0)
112 longjmp(bd->jmpbuf,RETVAL_UNEXPECTED_INPUT_EOF); 117 longjmp(bd->jmpbuf,RETVAL_UNEXPECTED_INPUT_EOF);
113 bd->inbufPos=0; 118 bd->inbufPos=0;
114 } 119 }
120
115 /* Avoid 32-bit overflow (dump bit buffer to top of output) */ 121 /* Avoid 32-bit overflow (dump bit buffer to top of output) */
122
116 if(bd->inbufBitCount>=24) { 123 if(bd->inbufBitCount>=24) {
117 bits=bd->inbufBits&((1<<bd->inbufBitCount)-1); 124 bits=bd->inbufBits&((1<<bd->inbufBitCount)-1);
118 bits_wanted-=bd->inbufBitCount; 125 bits_wanted-=bd->inbufBitCount;
119 bits<<=bits_wanted; 126 bits<<=bits_wanted;
120 bd->inbufBitCount=0; 127 bd->inbufBitCount=0;
121 } 128 }
129
122 /* Grab next 8 bits of input from buffer. */ 130 /* Grab next 8 bits of input from buffer. */
131
123 bd->inbufBits=(bd->inbufBits<<8)|bd->inbuf[bd->inbufPos++]; 132 bd->inbufBits=(bd->inbufBits<<8)|bd->inbuf[bd->inbufPos++];
124 bd->inbufBitCount+=8; 133 bd->inbufBitCount+=8;
125 } 134 }
135
126 /* Calculate result */ 136 /* Calculate result */
137
127 bd->inbufBitCount-=bits_wanted; 138 bd->inbufBitCount-=bits_wanted;
128 bits|=(bd->inbufBits>>bd->inbufBitCount)&((1<<bits_wanted)-1); 139 bits|=(bd->inbufBits>>bd->inbufBitCount)&((1<<bits_wanted)-1);
129 140
@@ -143,26 +154,34 @@ static int get_next_block(bunzip_data *bd)
143 dbuf=bd->dbuf; 154 dbuf=bd->dbuf;
144 dbufSize=bd->dbufSize; 155 dbufSize=bd->dbufSize;
145 selectors=bd->selectors; 156 selectors=bd->selectors;
157
146 /* Reset longjmp I/O error handling */ 158 /* Reset longjmp I/O error handling */
159
147 i=setjmp(bd->jmpbuf); 160 i=setjmp(bd->jmpbuf);
148 if(i) return i; 161 if(i) return i;
162
149 /* Read in header signature and CRC, then validate signature. 163 /* Read in header signature and CRC, then validate signature.
150 (last block signature means CRC is for whole file, return now) */ 164 (last block signature means CRC is for whole file, return now) */
165
151 i = get_bits(bd,24); 166 i = get_bits(bd,24);
152 j = get_bits(bd,24); 167 j = get_bits(bd,24);
153 bd->headerCRC=get_bits(bd,32); 168 bd->headerCRC=get_bits(bd,32);
154 if ((i == 0x177245) && (j == 0x385090)) return RETVAL_LAST_BLOCK; 169 if ((i == 0x177245) && (j == 0x385090)) return RETVAL_LAST_BLOCK;
155 if ((i != 0x314159) || (j != 0x265359)) return RETVAL_NOT_BZIP_DATA; 170 if ((i != 0x314159) || (j != 0x265359)) return RETVAL_NOT_BZIP_DATA;
171
156 /* We can add support for blockRandomised if anybody complains. There was 172 /* We can add support for blockRandomised if anybody complains. There was
157 some code for this in busybox 1.0.0-pre3, but nobody ever noticed that 173 some code for this in busybox 1.0.0-pre3, but nobody ever noticed that
158 it didn't actually work. */ 174 it didn't actually work. */
175
159 if(get_bits(bd,1)) return RETVAL_OBSOLETE_INPUT; 176 if(get_bits(bd,1)) return RETVAL_OBSOLETE_INPUT;
160 if((origPtr=get_bits(bd,24)) > dbufSize) return RETVAL_DATA_ERROR; 177 if((origPtr=get_bits(bd,24)) > dbufSize) return RETVAL_DATA_ERROR;
178
161 /* mapping table: if some byte values are never used (encoding things 179 /* mapping table: if some byte values are never used (encoding things
162 like ascii text), the compression code removes the gaps to have fewer 180 like ascii text), the compression code removes the gaps to have fewer
163 symbols to deal with, and writes a sparse bitfield indicating which 181 symbols to deal with, and writes a sparse bitfield indicating which
164 values were present. We make a translation table to convert the symbols 182 values were present. We make a translation table to convert the symbols
165 back to the corresponding bytes. */ 183 back to the corresponding bytes. */
184
166 t=get_bits(bd, 16); 185 t=get_bits(bd, 16);
167 symTotal=0; 186 symTotal=0;
168 for (i=0;i<16;i++) { 187 for (i=0;i<16;i++) {
@@ -172,60 +191,81 @@ static int get_next_block(bunzip_data *bd)
172 if(k&(1<<(15-j))) symToByte[symTotal++]=(16*i)+j; 191 if(k&(1<<(15-j))) symToByte[symTotal++]=(16*i)+j;
173 } 192 }
174 } 193 }
194
175 /* How many different Huffman coding groups does this block use? */ 195 /* How many different Huffman coding groups does this block use? */
196
176 groupCount=get_bits(bd,3); 197 groupCount=get_bits(bd,3);
177 if (groupCount<2 || groupCount>MAX_GROUPS) return RETVAL_DATA_ERROR; 198 if (groupCount<2 || groupCount>MAX_GROUPS) return RETVAL_DATA_ERROR;
199
178 /* nSelectors: Every GROUP_SIZE many symbols we select a new Huffman coding 200 /* nSelectors: Every GROUP_SIZE many symbols we select a new Huffman coding
179 group. Read in the group selector list, which is stored as MTF encoded 201 group. Read in the group selector list, which is stored as MTF encoded
180 bit runs. (MTF=Move To Front, as each value is used it's moved to the 202 bit runs. (MTF=Move To Front, as each value is used it's moved to the
181 start of the list.) */ 203 start of the list.) */
204
182 if(!(nSelectors=get_bits(bd, 15))) return RETVAL_DATA_ERROR; 205 if(!(nSelectors=get_bits(bd, 15))) return RETVAL_DATA_ERROR;
183 for(i=0; i<groupCount; i++) mtfSymbol[i] = i; 206 for(i=0; i<groupCount; i++) mtfSymbol[i] = i;
184 for(i=0; i<nSelectors; i++) { 207 for(i=0; i<nSelectors; i++) {
208
185 /* Get next value */ 209 /* Get next value */
210
186 for(j=0;get_bits(bd,1);j++) if (j>=groupCount) return RETVAL_DATA_ERROR; 211 for(j=0;get_bits(bd,1);j++) if (j>=groupCount) return RETVAL_DATA_ERROR;
212
187 /* Decode MTF to get the next selector */ 213 /* Decode MTF to get the next selector */
214
188 uc = mtfSymbol[j]; 215 uc = mtfSymbol[j];
189 for(;j;j--) mtfSymbol[j] = mtfSymbol[j-1]; 216 for(;j;j--) mtfSymbol[j] = mtfSymbol[j-1];
190 mtfSymbol[0]=selectors[i]=uc; 217 mtfSymbol[0]=selectors[i]=uc;
191 } 218 }
219
192 /* Read the Huffman coding tables for each group, which code for symTotal 220 /* Read the Huffman coding tables for each group, which code for symTotal
193 literal symbols, plus two run symbols (RUNA, RUNB) */ 221 literal symbols, plus two run symbols (RUNA, RUNB) */
222
194 symCount=symTotal+2; 223 symCount=symTotal+2;
195 for (j=0; j<groupCount; j++) { 224 for (j=0; j<groupCount; j++) {
196 unsigned char length[MAX_SYMBOLS],temp[MAX_HUFCODE_BITS+1]; 225 unsigned char length[MAX_SYMBOLS],temp[MAX_HUFCODE_BITS+1];
197 int minLen, maxLen, pp; 226 int minLen, maxLen, pp;
227
198 /* Read Huffman code lengths for each symbol. They're stored in 228 /* Read Huffman code lengths for each symbol. They're stored in
199 a way similar to mtf; record a starting value for the first symbol, 229 a way similar to mtf; record a starting value for the first symbol,
200 and an offset from the previous value for everys symbol after that. 230 and an offset from the previous value for everys symbol after that.
201 (Subtracting 1 before the loop and then adding it back at the end is 231 (Subtracting 1 before the loop and then adding it back at the end is
202 an optimization that makes the test inside the loop simpler: symbol 232 an optimization that makes the test inside the loop simpler: symbol
203 length 0 becomes negative, so an unsigned inequality catches it.) */ 233 length 0 becomes negative, so an unsigned inequality catches it.) */
234
204 t=get_bits(bd, 5)-1; 235 t=get_bits(bd, 5)-1;
205 for (i = 0; i < symCount; i++) { 236 for (i = 0; i < symCount; i++) {
206 for(;;) { 237 for(;;) {
207 if (((unsigned)t) > (MAX_HUFCODE_BITS-1)) 238 if (((unsigned)t) > (MAX_HUFCODE_BITS-1))
208 return RETVAL_DATA_ERROR; 239 return RETVAL_DATA_ERROR;
240
209 /* If first bit is 0, stop. Else second bit indicates whether 241 /* If first bit is 0, stop. Else second bit indicates whether
210 to increment or decrement the value. Optimization: grab 2 242 to increment or decrement the value. Optimization: grab 2
211 bits and unget the second if the first was 0. */ 243 bits and unget the second if the first was 0. */
244
212 k = get_bits(bd,2); 245 k = get_bits(bd,2);
213 if (k < 2) { 246 if (k < 2) {
214 bd->inbufBitCount++; 247 bd->inbufBitCount++;
215 break; 248 break;
216 } 249 }
250
217 /* Add one if second bit 1, else subtract 1. Avoids if/else */ 251 /* Add one if second bit 1, else subtract 1. Avoids if/else */
252
218 t+=(((k+1)&2)-1); 253 t+=(((k+1)&2)-1);
219 } 254 }
255
220 /* Correct for the initial -1, to get the final symbol length */ 256 /* Correct for the initial -1, to get the final symbol length */
257
221 length[i]=t+1; 258 length[i]=t+1;
222 } 259 }
260
223 /* Find largest and smallest lengths in this group */ 261 /* Find largest and smallest lengths in this group */
262
224 minLen=maxLen=length[0]; 263 minLen=maxLen=length[0];
225 for(i = 1; i < symCount; i++) { 264 for(i = 1; i < symCount; i++) {
226 if(length[i] > maxLen) maxLen = length[i]; 265 if(length[i] > maxLen) maxLen = length[i];
227 else if(length[i] < minLen) minLen = length[i]; 266 else if(length[i] < minLen) minLen = length[i];
228 } 267 }
268
229 /* Calculate permute[], base[], and limit[] tables from length[]. 269 /* Calculate permute[], base[], and limit[] tables from length[].
230 * 270 *
231 * permute[] is the lookup table for converting Huffman coded symbols 271 * permute[] is the lookup table for converting Huffman coded symbols
@@ -236,36 +276,47 @@ static int get_next_block(bunzip_data *bd)
236 * number of bits can have. This is how the Huffman codes can vary in 276 * number of bits can have. This is how the Huffman codes can vary in
237 * length: each code with a value>limit[length] needs another bit. 277 * length: each code with a value>limit[length] needs another bit.
238 */ 278 */
279
239 hufGroup=bd->groups+j; 280 hufGroup=bd->groups+j;
240 hufGroup->minLen = minLen; 281 hufGroup->minLen = minLen;
241 hufGroup->maxLen = maxLen; 282 hufGroup->maxLen = maxLen;
283
242 /* Note that minLen can't be smaller than 1, so we adjust the base 284 /* Note that minLen can't be smaller than 1, so we adjust the base
243 and limit array pointers so we're not always wasting the first 285 and limit array pointers so we're not always wasting the first
244 entry. We do this again when using them (during symbol decoding).*/ 286 entry. We do this again when using them (during symbol decoding).*/
287
245 base=hufGroup->base-1; 288 base=hufGroup->base-1;
246 limit=hufGroup->limit-1; 289 limit=hufGroup->limit-1;
290
247 /* Calculate permute[]. Concurently, initialize temp[] and limit[]. */ 291 /* Calculate permute[]. Concurently, initialize temp[] and limit[]. */
292
248 pp=0; 293 pp=0;
249 for(i=minLen;i<=maxLen;i++) { 294 for(i=minLen;i<=maxLen;i++) {
250 temp[i]=limit[i]=0; 295 temp[i]=limit[i]=0;
251 for(t=0;t<symCount;t++) 296 for(t=0;t<symCount;t++)
252 if(length[t]==i) hufGroup->permute[pp++] = t; 297 if(length[t]==i) hufGroup->permute[pp++] = t;
253 } 298 }
299
254 /* Count symbols coded for at each bit length */ 300 /* Count symbols coded for at each bit length */
301
255 for (i=0;i<symCount;i++) temp[length[i]]++; 302 for (i=0;i<symCount;i++) temp[length[i]]++;
303
256 /* Calculate limit[] (the largest symbol-coding value at each bit 304 /* Calculate limit[] (the largest symbol-coding value at each bit
257 * length, which is (previous limit<<1)+symbols at this level), and 305 * length, which is (previous limit<<1)+symbols at this level), and
258 * base[] (number of symbols to ignore at each bit length, which is 306 * base[] (number of symbols to ignore at each bit length, which is
259 * limit minus the cumulative count of symbols coded for already). */ 307 * limit minus the cumulative count of symbols coded for already). */
308
260 pp=t=0; 309 pp=t=0;
261 for (i=minLen; i<maxLen; i++) { 310 for (i=minLen; i<maxLen; i++) {
262 pp+=temp[i]; 311 pp+=temp[i];
312
263 /* We read the largest possible symbol size and then unget bits 313 /* We read the largest possible symbol size and then unget bits
264 after determining how many we need, and those extra bits could 314 after determining how many we need, and those extra bits could
265 be set to anything. (They're noise from future symbols.) At 315 be set to anything. (They're noise from future symbols.) At
266 each level we're really only interested in the first few bits, 316 each level we're really only interested in the first few bits,
267 so here we set all the trailing to-be-ignored bits to 1 so they 317 so here we set all the trailing to-be-ignored bits to 1 so they
268 don't affect the value>limit[length] comparison. */ 318 don't affect the value>limit[length] comparison. */
319
269 limit[i]= (pp << (maxLen - i)) - 1; 320 limit[i]= (pp << (maxLen - i)) - 1;
270 pp<<=1; 321 pp<<=1;
271 base[i+1]=pp-(t+=temp[i]); 322 base[i+1]=pp-(t+=temp[i]);
@@ -274,26 +325,34 @@ static int get_next_block(bunzip_data *bd)
274 limit[maxLen]=pp+temp[maxLen]-1; 325 limit[maxLen]=pp+temp[maxLen]-1;
275 base[minLen]=0; 326 base[minLen]=0;
276 } 327 }
328
277 /* We've finished reading and digesting the block header. Now read this 329 /* We've finished reading and digesting the block header. Now read this
278 block's Huffman coded symbols from the file and undo the Huffman coding 330 block's Huffman coded symbols from the file and undo the Huffman coding
279 and run length encoding, saving the result into dbuf[dbufCount++]=uc */ 331 and run length encoding, saving the result into dbuf[dbufCount++]=uc */
280 332
281 /* Initialize symbol occurrence counters and symbol Move To Front table */ 333 /* Initialize symbol occurrence counters and symbol Move To Front table */
334
282 for(i=0;i<256;i++) { 335 for(i=0;i<256;i++) {
283 byteCount[i] = 0; 336 byteCount[i] = 0;
284 mtfSymbol[i]=(unsigned char)i; 337 mtfSymbol[i]=(unsigned char)i;
285 } 338 }
339
286 /* Loop through compressed symbols. */ 340 /* Loop through compressed symbols. */
341
287 runPos=dbufCount=selector=0; 342 runPos=dbufCount=selector=0;
288 for(;;) { 343 for(;;) {
344
289 /* fetch next Huffman coding group from list. */ 345 /* fetch next Huffman coding group from list. */
346
290 symCount=GROUP_SIZE-1; 347 symCount=GROUP_SIZE-1;
291 if(selector>=nSelectors) return RETVAL_DATA_ERROR; 348 if(selector>=nSelectors) return RETVAL_DATA_ERROR;
292 hufGroup=bd->groups+selectors[selector++]; 349 hufGroup=bd->groups+selectors[selector++];
293 base=hufGroup->base-1; 350 base=hufGroup->base-1;
294 limit=hufGroup->limit-1; 351 limit=hufGroup->limit-1;
295continue_this_group: 352continue_this_group:
353
296 /* Read next Huffman-coded symbol. */ 354 /* Read next Huffman-coded symbol. */
355
297 /* Note: It is far cheaper to read maxLen bits and back up than it is 356 /* Note: It is far cheaper to read maxLen bits and back up than it is
298 to read minLen bits and then an additional bit at a time, testing 357 to read minLen bits and then an additional bit at a time, testing
299 as we go. Because there is a trailing last block (with file CRC), 358 as we go. Because there is a trailing last block (with file CRC),
@@ -303,6 +362,7 @@ continue_this_group:
303 dry). The following (up to got_huff_bits:) is equivalent to 362 dry). The following (up to got_huff_bits:) is equivalent to
304 j=get_bits(bd,hufGroup->maxLen); 363 j=get_bits(bd,hufGroup->maxLen);
305 */ 364 */
365
306 while (bd->inbufBitCount<hufGroup->maxLen) { 366 while (bd->inbufBitCount<hufGroup->maxLen) {
307 if(bd->inbufPos==bd->inbufCount) { 367 if(bd->inbufPos==bd->inbufCount) {
308 j = get_bits(bd,hufGroup->maxLen); 368 j = get_bits(bd,hufGroup->maxLen);
@@ -313,27 +373,37 @@ continue_this_group:
313 }; 373 };
314 bd->inbufBitCount-=hufGroup->maxLen; 374 bd->inbufBitCount-=hufGroup->maxLen;
315 j = (bd->inbufBits>>bd->inbufBitCount)&((1<<hufGroup->maxLen)-1); 375 j = (bd->inbufBits>>bd->inbufBitCount)&((1<<hufGroup->maxLen)-1);
376
316got_huff_bits: 377got_huff_bits:
378
317 /* Figure how how many bits are in next symbol and unget extras */ 379 /* Figure how how many bits are in next symbol and unget extras */
380
318 i=hufGroup->minLen; 381 i=hufGroup->minLen;
319 while(j>limit[i]) ++i; 382 while(j>limit[i]) ++i;
320 bd->inbufBitCount += (hufGroup->maxLen - i); 383 bd->inbufBitCount += (hufGroup->maxLen - i);
384
321 /* Huffman decode value to get nextSym (with bounds checking) */ 385 /* Huffman decode value to get nextSym (with bounds checking) */
386
322 if ((i > hufGroup->maxLen) 387 if ((i > hufGroup->maxLen)
323 || (((unsigned)(j=(j>>(hufGroup->maxLen-i))-base[i])) 388 || (((unsigned)(j=(j>>(hufGroup->maxLen-i))-base[i]))
324 >= MAX_SYMBOLS)) 389 >= MAX_SYMBOLS))
325 return RETVAL_DATA_ERROR; 390 return RETVAL_DATA_ERROR;
326 nextSym = hufGroup->permute[j]; 391 nextSym = hufGroup->permute[j];
392
327 /* We have now decoded the symbol, which indicates either a new literal 393 /* We have now decoded the symbol, which indicates either a new literal
328 byte, or a repeated run of the most recent literal byte. First, 394 byte, or a repeated run of the most recent literal byte. First,
329 check if nextSym indicates a repeated run, and if so loop collecting 395 check if nextSym indicates a repeated run, and if so loop collecting
330 how many times to repeat the last literal. */ 396 how many times to repeat the last literal. */
397
331 if (((unsigned)nextSym) <= SYMBOL_RUNB) { /* RUNA or RUNB */ 398 if (((unsigned)nextSym) <= SYMBOL_RUNB) { /* RUNA or RUNB */
399
332 /* If this is the start of a new run, zero out counter */ 400 /* If this is the start of a new run, zero out counter */
401
333 if(!runPos) { 402 if(!runPos) {
334 runPos = 1; 403 runPos = 1;
335 t = 0; 404 t = 0;
336 } 405 }
406
337 /* Neat trick that saves 1 symbol: instead of or-ing 0 or 1 at 407 /* Neat trick that saves 1 symbol: instead of or-ing 0 or 1 at
338 each bit position, add 1 or 2 instead. For example, 408 each bit position, add 1 or 2 instead. For example,
339 1011 is 1<<0 + 1<<1 + 2<<2. 1010 is 2<<0 + 2<<1 + 1<<2. 409 1011 is 1<<0 + 1<<1 + 2<<2. 1010 is 2<<0 + 2<<1 + 1<<2.
@@ -341,14 +411,17 @@ got_huff_bits:
341 the basic or 0/1 method (except all bits 0, which would use no 411 the basic or 0/1 method (except all bits 0, which would use no
342 symbols, but a run of length 0 doesn't mean anything in this 412 symbols, but a run of length 0 doesn't mean anything in this
343 context). Thus space is saved. */ 413 context). Thus space is saved. */
414
344 t += (runPos << nextSym); /* +runPos if RUNA; +2*runPos if RUNB */ 415 t += (runPos << nextSym); /* +runPos if RUNA; +2*runPos if RUNB */
345 runPos <<= 1; 416 runPos <<= 1;
346 goto end_of_huffman_loop; 417 goto end_of_huffman_loop;
347 } 418 }
419
348 /* When we hit the first non-run symbol after a run, we now know 420 /* When we hit the first non-run symbol after a run, we now know
349 how many times to repeat the last literal, so append that many 421 how many times to repeat the last literal, so append that many
350 copies to our buffer of decoded symbols (dbuf) now. (The last 422 copies to our buffer of decoded symbols (dbuf) now. (The last
351 literal used is the one at the head of the mtfSymbol array.) */ 423 literal used is the one at the head of the mtfSymbol array.) */
424
352 if(runPos) { 425 if(runPos) {
353 runPos=0; 426 runPos=0;
354 if(dbufCount+t>=dbufSize) return RETVAL_DATA_ERROR; 427 if(dbufCount+t>=dbufSize) return RETVAL_DATA_ERROR;
@@ -357,8 +430,11 @@ got_huff_bits:
357 byteCount[uc] += t; 430 byteCount[uc] += t;
358 while(t--) dbuf[dbufCount++]=uc; 431 while(t--) dbuf[dbufCount++]=uc;
359 } 432 }
433
360 /* Is this the terminating symbol? */ 434 /* Is this the terminating symbol? */
435
361 if(nextSym>symTotal) break; 436 if(nextSym>symTotal) break;
437
362 /* At this point, nextSym indicates a new literal character. Subtract 438 /* At this point, nextSym indicates a new literal character. Subtract
363 one to get the position in the MTF array at which this literal is 439 one to get the position in the MTF array at which this literal is
364 currently to be found. (Note that the result can't be -1 or 0, 440 currently to be found. (Note that the result can't be -1 or 0,
@@ -366,48 +442,62 @@ got_huff_bits:
366 first symbol in the mtf array, position 0, would have been handled 442 first symbol in the mtf array, position 0, would have been handled
367 as part of a run above. Therefore 1 unused mtf position minus 443 as part of a run above. Therefore 1 unused mtf position minus
368 2 non-literal nextSym values equals -1.) */ 444 2 non-literal nextSym values equals -1.) */
445
369 if(dbufCount>=dbufSize) return RETVAL_DATA_ERROR; 446 if(dbufCount>=dbufSize) return RETVAL_DATA_ERROR;
370 i = nextSym - 1; 447 i = nextSym - 1;
371 uc = mtfSymbol[i]; 448 uc = mtfSymbol[i];
449
372 /* Adjust the MTF array. Since we typically expect to move only a 450 /* Adjust the MTF array. Since we typically expect to move only a
373 * small number of symbols, and are bound by 256 in any case, using 451 * small number of symbols, and are bound by 256 in any case, using
374 * memmove here would typically be bigger and slower due to function 452 * memmove here would typically be bigger and slower due to function
375 * call overhead and other assorted setup costs. */ 453 * call overhead and other assorted setup costs. */
454
376 do { 455 do {
377 mtfSymbol[i] = mtfSymbol[i-1]; 456 mtfSymbol[i] = mtfSymbol[i-1];
378 } while (--i); 457 } while (--i);
379 mtfSymbol[0] = uc; 458 mtfSymbol[0] = uc;
380 uc=symToByte[uc]; 459 uc=symToByte[uc];
460
381 /* We have our literal byte. Save it into dbuf. */ 461 /* We have our literal byte. Save it into dbuf. */
462
382 byteCount[uc]++; 463 byteCount[uc]++;
383 dbuf[dbufCount++] = (unsigned int)uc; 464 dbuf[dbufCount++] = (unsigned int)uc;
384 /* Skip group initialization if we're not done with this group. Done this 465
385 * way to avoid compiler warning. */ 466 /* Skip group initialization if we're not done with this group. Done
467 * this way to avoid compiler warning. */
468
386end_of_huffman_loop: 469end_of_huffman_loop:
387 if(symCount--) goto continue_this_group; 470 if(symCount--) goto continue_this_group;
388 } 471 }
472
389 /* At this point, we've read all the Huffman-coded symbols (and repeated 473 /* At this point, we've read all the Huffman-coded symbols (and repeated
390 runs) for this block from the input stream, and decoded them into the 474 runs) for this block from the input stream, and decoded them into the
391 intermediate buffer. There are dbufCount many decoded bytes in dbuf[]. 475 intermediate buffer. There are dbufCount many decoded bytes in dbuf[].
392 Now undo the Burrows-Wheeler transform on dbuf. 476 Now undo the Burrows-Wheeler transform on dbuf.
393 See http://dogma.net/markn/articles/bwt/bwt.htm 477 See http://dogma.net/markn/articles/bwt/bwt.htm
394 */ 478 */
479
395 /* Turn byteCount into cumulative occurrence counts of 0 to n-1. */ 480 /* Turn byteCount into cumulative occurrence counts of 0 to n-1. */
481
396 j=0; 482 j=0;
397 for(i=0;i<256;i++) { 483 for(i=0;i<256;i++) {
398 k=j+byteCount[i]; 484 k=j+byteCount[i];
399 byteCount[i] = j; 485 byteCount[i] = j;
400 j=k; 486 j=k;
401 } 487 }
488
402 /* Figure out what order dbuf would be in if we sorted it. */ 489 /* Figure out what order dbuf would be in if we sorted it. */
490
403 for (i=0;i<dbufCount;i++) { 491 for (i=0;i<dbufCount;i++) {
404 uc=(unsigned char)(dbuf[i] & 0xff); 492 uc=(unsigned char)(dbuf[i] & 0xff);
405 dbuf[byteCount[uc]] |= (i << 8); 493 dbuf[byteCount[uc]] |= (i << 8);
406 byteCount[uc]++; 494 byteCount[uc]++;
407 } 495 }
496
408 /* Decode first byte by hand to initialize "previous" byte. Note that it 497 /* Decode first byte by hand to initialize "previous" byte. Note that it
409 doesn't get output, and if the first three characters are identical 498 doesn't get output, and if the first three characters are identical
410 it doesn't qualify as a run (hence writeRunCountdown=5). */ 499 it doesn't qualify as a run (hence writeRunCountdown=5). */
500
411 if(dbufCount) { 501 if(dbufCount) {
412 if(origPtr>=dbufCount) return RETVAL_DATA_ERROR; 502 if(origPtr>=dbufCount) return RETVAL_DATA_ERROR;
413 bd->writePos=dbuf[origPtr]; 503 bd->writePos=dbuf[origPtr];
@@ -445,22 +535,32 @@ static int read_bunzip(bunzip_data *bd, char *outbuf, int len)
445 Huffman-decoded a block into the intermediate buffer yet). */ 535 Huffman-decoded a block into the intermediate buffer yet). */
446 536
447 if (bd->writeCopies) { 537 if (bd->writeCopies) {
538
448 /* Inside the loop, writeCopies means extra copies (beyond 1) */ 539 /* Inside the loop, writeCopies means extra copies (beyond 1) */
540
449 --bd->writeCopies; 541 --bd->writeCopies;
542
450 /* Loop outputting bytes */ 543 /* Loop outputting bytes */
544
451 for(;;) { 545 for(;;) {
546
452 /* If the output buffer is full, snapshot state and return */ 547 /* If the output buffer is full, snapshot state and return */
548
453 if(gotcount >= len) { 549 if(gotcount >= len) {
454 bd->writePos=pos; 550 bd->writePos=pos;
455 bd->writeCurrent=current; 551 bd->writeCurrent=current;
456 bd->writeCopies++; 552 bd->writeCopies++;
457 return len; 553 return len;
458 } 554 }
555
459 /* Write next byte into output buffer, updating CRC */ 556 /* Write next byte into output buffer, updating CRC */
557
460 outbuf[gotcount++] = current; 558 outbuf[gotcount++] = current;
461 bd->writeCRC=(((bd->writeCRC)<<8) 559 bd->writeCRC=(((bd->writeCRC)<<8)
462 ^bd->crc32Table[((bd->writeCRC)>>24)^current]); 560 ^bd->crc32Table[((bd->writeCRC)>>24)^current]);
561
463 /* Loop now if we're outputting multiple copies of this byte */ 562 /* Loop now if we're outputting multiple copies of this byte */
563
464 if (bd->writeCopies) { 564 if (bd->writeCopies) {
465 --bd->writeCopies; 565 --bd->writeCopies;
466 continue; 566 continue;
@@ -472,26 +572,38 @@ decode_next_byte:
472 pos=dbuf[pos]; 572 pos=dbuf[pos];
473 current=pos&0xff; 573 current=pos&0xff;
474 pos>>=8; 574 pos>>=8;
575
475 /* After 3 consecutive copies of the same byte, the 4th is a repeat 576 /* After 3 consecutive copies of the same byte, the 4th is a repeat
476 count. We count down from 4 instead 577 count. We count down from 4 instead
477 * of counting up because testing for non-zero is faster */ 578 * of counting up because testing for non-zero is faster */
579
478 if(--bd->writeRunCountdown) { 580 if(--bd->writeRunCountdown) {
479 if(current!=previous) bd->writeRunCountdown=4; 581 if(current!=previous) bd->writeRunCountdown=4;
480 } else { 582 } else {
583
481 /* We have a repeated run, this byte indicates the count */ 584 /* We have a repeated run, this byte indicates the count */
585
482 bd->writeCopies=current; 586 bd->writeCopies=current;
483 current=previous; 587 current=previous;
484 bd->writeRunCountdown=5; 588 bd->writeRunCountdown=5;
589
485 /* Sometimes there are just 3 bytes (run length 0) */ 590 /* Sometimes there are just 3 bytes (run length 0) */
591
486 if(!bd->writeCopies) goto decode_next_byte; 592 if(!bd->writeCopies) goto decode_next_byte;
593
487 /* Subtract the 1 copy we'd output anyway to get extras */ 594 /* Subtract the 1 copy we'd output anyway to get extras */
595
488 --bd->writeCopies; 596 --bd->writeCopies;
489 } 597 }
490 } 598 }
599
491 /* Decompression of this block completed successfully */ 600 /* Decompression of this block completed successfully */
601
492 bd->writeCRC=~bd->writeCRC; 602 bd->writeCRC=~bd->writeCRC;
493 bd->totalCRC=((bd->totalCRC<<1) | (bd->totalCRC>>31)) ^ bd->writeCRC; 603 bd->totalCRC=((bd->totalCRC<<1) | (bd->totalCRC>>31)) ^ bd->writeCRC;
604
494 /* If this block had a CRC error, force file level CRC error. */ 605 /* If this block had a CRC error, force file level CRC error. */
606
495 if(bd->writeCRC!=bd->headerCRC) { 607 if(bd->writeCRC!=bd->headerCRC) {
496 bd->totalCRC=bd->headerCRC+1; 608 bd->totalCRC=bd->headerCRC+1;
497 return RETVAL_LAST_BLOCK; 609 return RETVAL_LAST_BLOCK;
@@ -500,6 +612,7 @@ decode_next_byte:
500 612
501 /* Refill the intermediate buffer by Huffman-decoding next block of input */ 613 /* Refill the intermediate buffer by Huffman-decoding next block of input */
502 /* (previous is just a convenient unused temp variable here) */ 614 /* (previous is just a convenient unused temp variable here) */
615
503 previous=get_next_block(bd); 616 previous=get_next_block(bd);
504 if(previous) { 617 if(previous) {
505 bd->writeCount=previous; 618 bd->writeCount=previous;
@@ -514,6 +627,7 @@ decode_next_byte:
514/* Allocate the structure, read file header. If in_fd==-1, inbuf must contain 627/* Allocate the structure, read file header. If in_fd==-1, inbuf must contain
515 a complete bunzip file (len bytes long). If in_fd!=-1, inbuf and len are 628 a complete bunzip file (len bytes long). If in_fd!=-1, inbuf and len are
516 ignored, and data is read from file handle into temporary buffer. */ 629 ignored, and data is read from file handle into temporary buffer. */
630
517static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf, 631static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf,
518 int len) 632 int len)
519{ 633{
@@ -523,33 +637,44 @@ static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf,
523 +(((unsigned int)'h')<<8)+(unsigned int)'0'; 637 +(((unsigned int)'h')<<8)+(unsigned int)'0';
524 638
525 /* Figure out how much data to allocate */ 639 /* Figure out how much data to allocate */
640
526 i=sizeof(bunzip_data); 641 i=sizeof(bunzip_data);
527 if(in_fd!=-1) i+=IOBUF_SIZE; 642 if(in_fd!=-1) i+=IOBUF_SIZE;
643
528 /* Allocate bunzip_data. Most fields initialize to zero. */ 644 /* Allocate bunzip_data. Most fields initialize to zero. */
645
529 bd=*bdp=xmalloc(i); 646 bd=*bdp=xmalloc(i);
530 memset(bd,0,sizeof(bunzip_data)); 647 memset(bd,0,sizeof(bunzip_data));
648
531 /* Setup input buffer */ 649 /* Setup input buffer */
650
532 if(-1==(bd->in_fd=in_fd)) { 651 if(-1==(bd->in_fd=in_fd)) {
533 bd->inbuf=inbuf; 652 bd->inbuf=inbuf;
534 bd->inbufCount=len; 653 bd->inbufCount=len;
535 } else bd->inbuf=(unsigned char *)(bd+1); 654 } else bd->inbuf=(unsigned char *)(bd+1);
655
536 /* Init the CRC32 table (big endian) */ 656 /* Init the CRC32 table (big endian) */
657
537 for(i=0;i<256;i++) { 658 for(i=0;i<256;i++) {
538 c=i<<24; 659 c=i<<24;
539 for(j=8;j;j--) 660 for(j=8;j;j--)
540 c=c&0x80000000 ? (c<<1)^0x04c11db7 : (c<<1); 661 c=c&0x80000000 ? (c<<1)^0x04c11db7 : (c<<1);
541 bd->crc32Table[i]=c; 662 bd->crc32Table[i]=c;
542 } 663 }
664
543 /* Setup for I/O error handling via longjmp */ 665 /* Setup for I/O error handling via longjmp */
666
544 i=setjmp(bd->jmpbuf); 667 i=setjmp(bd->jmpbuf);
545 if(i) return i; 668 if(i) return i;
546 669
547 /* Ensure that file starts with "BZh['1'-'9']." */ 670 /* Ensure that file starts with "BZh['1'-'9']." */
671
548 i = get_bits(bd,32); 672 i = get_bits(bd,32);
549 if (((unsigned int)(i-BZh0-1)) >= 9) return RETVAL_NOT_BZIP_DATA; 673 if (((unsigned int)(i-BZh0-1)) >= 9) return RETVAL_NOT_BZIP_DATA;
550 674
551 /* Fourth byte (ascii '1'-'9'), indicates block size in units of 100k of 675 /* Fourth byte (ascii '1'-'9'), indicates block size in units of 100k of
552 uncompressed data. Allocate intermediate buffer for block. */ 676 uncompressed data. Allocate intermediate buffer for block. */
677
553 bd->dbufSize=100000*(i-BZh0); 678 bd->dbufSize=100000*(i-BZh0);
554 679
555 bd->dbuf=xmalloc(bd->dbufSize * sizeof(int)); 680 bd->dbuf=xmalloc(bd->dbufSize * sizeof(int));
@@ -558,6 +683,7 @@ static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf,
558 683
559/* Example usage: decompress src_fd to dst_fd. (Stops at end of bzip data, 684/* Example usage: decompress src_fd to dst_fd. (Stops at end of bzip data,
560 not end of file.) */ 685 not end of file.) */
686
561extern int uncompressStream(int src_fd, int dst_fd) 687extern int uncompressStream(int src_fd, int dst_fd)
562{ 688{
563 char *outbuf; 689 char *outbuf;
@@ -574,15 +700,16 @@ extern int uncompressStream(int src_fd, int dst_fd)
574 } 700 }
575 } 701 }
576 } 702 }
703
577 /* Check CRC and release memory */ 704 /* Check CRC and release memory */
705
578 if(i==RETVAL_LAST_BLOCK) { 706 if(i==RETVAL_LAST_BLOCK) {
579 if (bd->headerCRC!=bd->totalCRC) { 707 if (bd->headerCRC!=bd->totalCRC) {
580 bb_error_msg("Data integrity error when decompressing."); 708 bb_error_msg("Data integrity error when decompressing.");
581 } else { 709 } else {
582 i=RETVAL_OK; 710 i=RETVAL_OK;
583 } 711 }
584 } 712 } else if (i==RETVAL_UNEXPECTED_OUTPUT_EOF) {
585 else if (i==RETVAL_UNEXPECTED_OUTPUT_EOF) {
586 bb_error_msg("Compressed file ends unexpectedly"); 713 bb_error_msg("Compressed file ends unexpectedly");
587 } else { 714 } else {
588 bb_error_msg("Decompression failed"); 715 bb_error_msg("Decompression failed");