Denis Vlasenko | 052ad9a | 2009-04-29 12:01:51 +0000 | [diff] [blame] | 1 | /* implementation of the LZO1X decompression algorithm |
| 2 | |
| 3 | This file is part of the LZO real-time data compression library. |
| 4 | |
| 5 | Copyright (C) 1996..2008 Markus Franz Xaver Johannes Oberhumer |
| 6 | All Rights Reserved. |
| 7 | |
| 8 | Markus F.X.J. Oberhumer <markus@oberhumer.com> |
| 9 | http://www.oberhumer.com/opensource/lzo/ |
| 10 | |
| 11 | The LZO library is free software; you can redistribute it and/or |
| 12 | modify it under the terms of the GNU General Public License as |
| 13 | published by the Free Software Foundation; either version 2 of |
| 14 | the License, or (at your option) any later version. |
| 15 | |
| 16 | The LZO library is distributed in the hope that it will be useful, |
| 17 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
Denys Vlasenko | 60cb48c | 2013-01-14 15:57:44 +0100 | [diff] [blame] | 18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
Denis Vlasenko | 052ad9a | 2009-04-29 12:01:51 +0000 | [diff] [blame] | 19 | GNU General Public License for more details. |
| 20 | |
| 21 | You should have received a copy of the GNU General Public License |
| 22 | along with the LZO library; see the file COPYING. |
| 23 | If not, write to the Free Software Foundation, Inc., |
| 24 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| 25 | */ |
| 26 | #include "libbb.h" |
| 27 | #include "liblzo.h" |
| 28 | |
| 29 | /*********************************************************************** |
| 30 | // decompress a block of data. |
| 31 | ************************************************************************/ |
| 32 | /* safe decompression with overrun testing */ |
| 33 | int lzo1x_decompress_safe(const uint8_t* in, unsigned in_len, |
| 34 | uint8_t* out, unsigned* out_len, |
| 35 | void* wrkmem UNUSED_PARAM) |
| 36 | { |
| 37 | register uint8_t* op; |
| 38 | register const uint8_t* ip; |
| 39 | register unsigned t; |
| 40 | #if defined(COPY_DICT) |
| 41 | unsigned m_off; |
| 42 | const uint8_t* dict_end; |
| 43 | #else |
| 44 | register const uint8_t* m_pos = NULL; /* possibly not needed */ |
| 45 | #endif |
| 46 | const uint8_t* const ip_end = in + in_len; |
| 47 | #if defined(HAVE_ANY_OP) |
| 48 | uint8_t* const op_end = out + *out_len; |
| 49 | #endif |
| 50 | #if defined(LZO1Z) |
| 51 | unsigned last_m_off = 0; |
| 52 | #endif |
| 53 | |
| 54 | // LZO_UNUSED(wrkmem); |
| 55 | |
| 56 | #if defined(COPY_DICT) |
| 57 | if (dict) { |
| 58 | if (dict_len > M4_MAX_OFFSET) { |
| 59 | dict += dict_len - M4_MAX_OFFSET; |
| 60 | dict_len = M4_MAX_OFFSET; |
| 61 | } |
| 62 | dict_end = dict + dict_len; |
| 63 | } else { |
| 64 | dict_len = 0; |
| 65 | dict_end = NULL; |
| 66 | } |
| 67 | #endif /* COPY_DICT */ |
| 68 | |
| 69 | *out_len = 0; |
| 70 | |
| 71 | op = out; |
| 72 | ip = in; |
| 73 | |
| 74 | if (*ip > 17) { |
| 75 | t = *ip++ - 17; |
| 76 | if (t < 4) |
| 77 | goto match_next; |
| 78 | assert(t > 0); NEED_OP(t); NEED_IP(t+1); |
| 79 | do *op++ = *ip++; while (--t > 0); |
| 80 | goto first_literal_run; |
| 81 | } |
| 82 | |
| 83 | while (TEST_IP && TEST_OP) { |
| 84 | t = *ip++; |
| 85 | if (t >= 16) |
| 86 | goto match; |
| 87 | /* a literal run */ |
| 88 | if (t == 0) { |
| 89 | NEED_IP(1); |
| 90 | while (*ip == 0) { |
| 91 | t += 255; |
| 92 | ip++; |
| 93 | NEED_IP(1); |
| 94 | } |
Denys Vlasenko | a9dc7c2 | 2014-06-30 10:14:34 +0200 | [diff] [blame^] | 95 | TEST_IV(t); |
Denis Vlasenko | 052ad9a | 2009-04-29 12:01:51 +0000 | [diff] [blame] | 96 | t += 15 + *ip++; |
| 97 | } |
| 98 | /* copy literals */ |
| 99 | assert(t > 0); |
| 100 | NEED_OP(t+3); |
| 101 | NEED_IP(t+4); |
| 102 | #if defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4) |
| 103 | # if !defined(LZO_UNALIGNED_OK_4) |
| 104 | if (PTR_ALIGNED2_4(op, ip)) |
| 105 | # endif |
| 106 | { |
| 107 | COPY4(op, ip); |
| 108 | op += 4; |
| 109 | ip += 4; |
| 110 | if (--t > 0) { |
| 111 | if (t >= 4) { |
| 112 | do { |
| 113 | COPY4(op, ip); |
| 114 | op += 4; |
| 115 | ip += 4; |
| 116 | t -= 4; |
| 117 | } while (t >= 4); |
| 118 | if (t > 0) |
| 119 | do *op++ = *ip++; while (--t > 0); |
| 120 | } else { |
| 121 | do *op++ = *ip++; while (--t > 0); |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | # if !defined(LZO_UNALIGNED_OK_4) |
| 126 | else |
| 127 | # endif |
| 128 | #endif |
| 129 | #if !defined(LZO_UNALIGNED_OK_4) |
| 130 | { |
| 131 | *op++ = *ip++; |
| 132 | *op++ = *ip++; |
| 133 | *op++ = *ip++; |
| 134 | do *op++ = *ip++; while (--t > 0); |
| 135 | } |
| 136 | #endif |
| 137 | |
| 138 | first_literal_run: |
| 139 | t = *ip++; |
| 140 | if (t >= 16) |
| 141 | goto match; |
| 142 | #if defined(COPY_DICT) |
| 143 | #if defined(LZO1Z) |
| 144 | m_off = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2); |
| 145 | last_m_off = m_off; |
| 146 | #else |
| 147 | m_off = (1 + M2_MAX_OFFSET) + (t >> 2) + (*ip++ << 2); |
| 148 | #endif |
| 149 | NEED_OP(3); |
| 150 | t = 3; COPY_DICT(t,m_off) |
| 151 | #else /* !COPY_DICT */ |
| 152 | #if defined(LZO1Z) |
| 153 | t = (1 + M2_MAX_OFFSET) + (t << 6) + (*ip++ >> 2); |
| 154 | m_pos = op - t; |
| 155 | last_m_off = t; |
| 156 | #else |
| 157 | m_pos = op - (1 + M2_MAX_OFFSET); |
| 158 | m_pos -= t >> 2; |
| 159 | m_pos -= *ip++ << 2; |
| 160 | #endif |
| 161 | TEST_LB(m_pos); NEED_OP(3); |
| 162 | *op++ = *m_pos++; |
| 163 | *op++ = *m_pos++; |
| 164 | *op++ = *m_pos; |
| 165 | #endif /* COPY_DICT */ |
| 166 | goto match_done; |
| 167 | |
| 168 | /* handle matches */ |
| 169 | do { |
| 170 | match: |
| 171 | if (t >= 64) { /* a M2 match */ |
| 172 | #if defined(COPY_DICT) |
| 173 | #if defined(LZO1X) |
| 174 | m_off = 1 + ((t >> 2) & 7) + (*ip++ << 3); |
| 175 | t = (t >> 5) - 1; |
| 176 | #elif defined(LZO1Y) |
| 177 | m_off = 1 + ((t >> 2) & 3) + (*ip++ << 2); |
| 178 | t = (t >> 4) - 3; |
| 179 | #elif defined(LZO1Z) |
| 180 | m_off = t & 0x1f; |
| 181 | if (m_off >= 0x1c) |
| 182 | m_off = last_m_off; |
| 183 | else { |
| 184 | m_off = 1 + (m_off << 6) + (*ip++ >> 2); |
| 185 | last_m_off = m_off; |
| 186 | } |
| 187 | t = (t >> 5) - 1; |
| 188 | #endif |
| 189 | #else /* !COPY_DICT */ |
| 190 | #if defined(LZO1X) |
| 191 | m_pos = op - 1; |
| 192 | m_pos -= (t >> 2) & 7; |
| 193 | m_pos -= *ip++ << 3; |
| 194 | t = (t >> 5) - 1; |
| 195 | #elif defined(LZO1Y) |
| 196 | m_pos = op - 1; |
| 197 | m_pos -= (t >> 2) & 3; |
| 198 | m_pos -= *ip++ << 2; |
| 199 | t = (t >> 4) - 3; |
| 200 | #elif defined(LZO1Z) |
| 201 | { |
| 202 | unsigned off = t & 0x1f; |
| 203 | m_pos = op; |
| 204 | if (off >= 0x1c) { |
| 205 | assert(last_m_off > 0); |
| 206 | m_pos -= last_m_off; |
| 207 | } else { |
| 208 | off = 1 + (off << 6) + (*ip++ >> 2); |
| 209 | m_pos -= off; |
| 210 | last_m_off = off; |
| 211 | } |
| 212 | } |
| 213 | t = (t >> 5) - 1; |
| 214 | #endif |
| 215 | TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1); |
| 216 | goto copy_match; |
| 217 | #endif /* COPY_DICT */ |
| 218 | } |
| 219 | else if (t >= 32) { /* a M3 match */ |
| 220 | t &= 31; |
| 221 | if (t == 0) { |
| 222 | NEED_IP(1); |
| 223 | while (*ip == 0) { |
| 224 | t += 255; |
| 225 | ip++; |
| 226 | NEED_IP(1); |
| 227 | } |
Denys Vlasenko | a9dc7c2 | 2014-06-30 10:14:34 +0200 | [diff] [blame^] | 228 | TEST_IV(t); |
Denis Vlasenko | 052ad9a | 2009-04-29 12:01:51 +0000 | [diff] [blame] | 229 | t += 31 + *ip++; |
| 230 | } |
| 231 | #if defined(COPY_DICT) |
| 232 | #if defined(LZO1Z) |
| 233 | m_off = 1 + (ip[0] << 6) + (ip[1] >> 2); |
| 234 | last_m_off = m_off; |
| 235 | #else |
| 236 | m_off = 1 + (ip[0] >> 2) + (ip[1] << 6); |
| 237 | #endif |
| 238 | #else /* !COPY_DICT */ |
| 239 | #if defined(LZO1Z) |
| 240 | { |
| 241 | unsigned off = 1 + (ip[0] << 6) + (ip[1] >> 2); |
| 242 | m_pos = op - off; |
| 243 | last_m_off = off; |
| 244 | } |
| 245 | #elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN) |
| 246 | m_pos = op - 1; |
| 247 | m_pos -= (* (const lzo_ushortp) ip) >> 2; |
| 248 | #else |
| 249 | m_pos = op - 1; |
| 250 | m_pos -= (ip[0] >> 2) + (ip[1] << 6); |
| 251 | #endif |
| 252 | #endif /* COPY_DICT */ |
| 253 | ip += 2; |
| 254 | } |
| 255 | else if (t >= 16) { /* a M4 match */ |
| 256 | #if defined(COPY_DICT) |
| 257 | m_off = (t & 8) << 11; |
| 258 | #else /* !COPY_DICT */ |
| 259 | m_pos = op; |
| 260 | m_pos -= (t & 8) << 11; |
| 261 | #endif /* COPY_DICT */ |
| 262 | t &= 7; |
| 263 | if (t == 0) { |
| 264 | NEED_IP(1); |
| 265 | while (*ip == 0) { |
| 266 | t += 255; |
| 267 | ip++; |
| 268 | NEED_IP(1); |
| 269 | } |
Denys Vlasenko | a9dc7c2 | 2014-06-30 10:14:34 +0200 | [diff] [blame^] | 270 | TEST_IV(t); |
Denis Vlasenko | 052ad9a | 2009-04-29 12:01:51 +0000 | [diff] [blame] | 271 | t += 7 + *ip++; |
| 272 | } |
| 273 | #if defined(COPY_DICT) |
| 274 | #if defined(LZO1Z) |
| 275 | m_off += (ip[0] << 6) + (ip[1] >> 2); |
| 276 | #else |
| 277 | m_off += (ip[0] >> 2) + (ip[1] << 6); |
| 278 | #endif |
| 279 | ip += 2; |
| 280 | if (m_off == 0) |
| 281 | goto eof_found; |
| 282 | m_off += 0x4000; |
| 283 | #if defined(LZO1Z) |
| 284 | last_m_off = m_off; |
| 285 | #endif |
| 286 | #else /* !COPY_DICT */ |
| 287 | #if defined(LZO1Z) |
| 288 | m_pos -= (ip[0] << 6) + (ip[1] >> 2); |
| 289 | #elif defined(LZO_UNALIGNED_OK_2) && defined(LZO_ABI_LITTLE_ENDIAN) |
| 290 | m_pos -= (* (const lzo_ushortp) ip) >> 2; |
| 291 | #else |
| 292 | m_pos -= (ip[0] >> 2) + (ip[1] << 6); |
| 293 | #endif |
| 294 | ip += 2; |
| 295 | if (m_pos == op) |
| 296 | goto eof_found; |
| 297 | m_pos -= 0x4000; |
| 298 | #if defined(LZO1Z) |
| 299 | last_m_off = pd((const uint8_t*)op, m_pos); |
| 300 | #endif |
| 301 | #endif /* COPY_DICT */ |
| 302 | } |
| 303 | else { /* a M1 match */ |
| 304 | #if defined(COPY_DICT) |
| 305 | #if defined(LZO1Z) |
| 306 | m_off = 1 + (t << 6) + (*ip++ >> 2); |
| 307 | last_m_off = m_off; |
| 308 | #else |
| 309 | m_off = 1 + (t >> 2) + (*ip++ << 2); |
| 310 | #endif |
| 311 | NEED_OP(2); |
| 312 | t = 2; COPY_DICT(t,m_off) |
| 313 | #else /* !COPY_DICT */ |
| 314 | #if defined(LZO1Z) |
| 315 | t = 1 + (t << 6) + (*ip++ >> 2); |
| 316 | m_pos = op - t; |
| 317 | last_m_off = t; |
| 318 | #else |
| 319 | m_pos = op - 1; |
| 320 | m_pos -= t >> 2; |
| 321 | m_pos -= *ip++ << 2; |
| 322 | #endif |
| 323 | TEST_LB(m_pos); NEED_OP(2); |
| 324 | *op++ = *m_pos++; |
| 325 | *op++ = *m_pos; |
| 326 | #endif /* COPY_DICT */ |
| 327 | goto match_done; |
| 328 | } |
| 329 | |
| 330 | /* copy match */ |
| 331 | #if defined(COPY_DICT) |
| 332 | |
| 333 | NEED_OP(t+3-1); |
| 334 | t += 3-1; COPY_DICT(t,m_off) |
| 335 | |
| 336 | #else /* !COPY_DICT */ |
| 337 | |
| 338 | TEST_LB(m_pos); assert(t > 0); NEED_OP(t+3-1); |
| 339 | #if defined(LZO_UNALIGNED_OK_4) || defined(LZO_ALIGNED_OK_4) |
| 340 | # if !defined(LZO_UNALIGNED_OK_4) |
| 341 | if (t >= 2 * 4 - (3 - 1) && PTR_ALIGNED2_4(op,m_pos)) { |
| 342 | assert((op - m_pos) >= 4); /* both pointers are aligned */ |
| 343 | # else |
| 344 | if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) { |
| 345 | # endif |
| 346 | COPY4(op,m_pos); |
| 347 | op += 4; m_pos += 4; t -= 4 - (3 - 1); |
| 348 | do { |
| 349 | COPY4(op,m_pos); |
| 350 | op += 4; m_pos += 4; t -= 4; |
| 351 | } while (t >= 4); |
| 352 | if (t > 0) |
| 353 | do *op++ = *m_pos++; while (--t > 0); |
| 354 | } |
| 355 | else |
| 356 | #endif |
| 357 | { |
| 358 | copy_match: |
| 359 | *op++ = *m_pos++; *op++ = *m_pos++; |
| 360 | do *op++ = *m_pos++; while (--t > 0); |
| 361 | } |
| 362 | |
| 363 | #endif /* COPY_DICT */ |
| 364 | |
| 365 | match_done: |
| 366 | #if defined(LZO1Z) |
| 367 | t = ip[-1] & 3; |
| 368 | #else |
| 369 | t = ip[-2] & 3; |
| 370 | #endif |
| 371 | if (t == 0) |
| 372 | break; |
| 373 | |
| 374 | /* copy literals */ |
| 375 | match_next: |
| 376 | assert(t > 0); |
| 377 | assert(t < 4); |
| 378 | NEED_OP(t); |
| 379 | NEED_IP(t+1); |
| 380 | #if 0 |
| 381 | do *op++ = *ip++; while (--t > 0); |
| 382 | #else |
| 383 | *op++ = *ip++; |
| 384 | if (t > 1) { |
| 385 | *op++ = *ip++; |
| 386 | if (t > 2) |
| 387 | *op++ = *ip++; |
| 388 | } |
| 389 | #endif |
| 390 | t = *ip++; |
| 391 | } while (TEST_IP && TEST_OP); |
| 392 | } |
| 393 | |
| 394 | //#if defined(HAVE_TEST_IP) || defined(HAVE_TEST_OP) |
| 395 | /* no EOF code was found */ |
| 396 | *out_len = pd(op, out); |
| 397 | return LZO_E_EOF_NOT_FOUND; |
| 398 | //#endif |
| 399 | |
| 400 | eof_found: |
| 401 | assert(t == 1); |
| 402 | *out_len = pd(op, out); |
| 403 | return (ip == ip_end ? LZO_E_OK : |
| 404 | (ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN)); |
| 405 | |
| 406 | //#if defined(HAVE_NEED_IP) |
| 407 | input_overrun: |
| 408 | *out_len = pd(op, out); |
| 409 | return LZO_E_INPUT_OVERRUN; |
| 410 | //#endif |
| 411 | |
| 412 | //#if defined(HAVE_NEED_OP) |
| 413 | output_overrun: |
| 414 | *out_len = pd(op, out); |
| 415 | return LZO_E_OUTPUT_OVERRUN; |
| 416 | //#endif |
| 417 | |
| 418 | //#if defined(LZO_TEST_OVERRUN_LOOKBEHIND) |
| 419 | lookbehind_overrun: |
| 420 | *out_len = pd(op, out); |
| 421 | return LZO_E_LOOKBEHIND_OVERRUN; |
| 422 | //#endif |
| 423 | } |