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| 1 /** |
| 2 * xzlib.c: front end for the transparent suport of lzma compression |
| 3 * at the I/O layer, based on an example file from lzma project |
| 4 * |
| 5 * See Copyright for the status of this software. |
| 6 * |
| 7 * Anders F Bjorklund <afb@users.sourceforge.net> |
| 8 */ |
| 9 #define IN_LIBXML |
| 10 #include "libxml.h" |
| 11 #ifdef HAVE_LZMA_H |
| 12 |
| 13 #include <string.h> |
| 14 #ifdef HAVE_ERRNO_H |
| 15 #include <errno.h> |
| 16 #endif |
| 17 |
| 18 |
| 19 #ifdef HAVE_SYS_TYPES_H |
| 20 #include <sys/types.h> |
| 21 #endif |
| 22 #ifdef HAVE_SYS_STAT_H |
| 23 #include <sys/stat.h> |
| 24 #endif |
| 25 #ifdef HAVE_FCNTL_H |
| 26 #include <fcntl.h> |
| 27 #endif |
| 28 #ifdef HAVE_UNISTD_H |
| 29 #include <unistd.h> |
| 30 #endif |
| 31 #ifdef HAVE_STDLIB_H |
| 32 #include <stdlib.h> |
| 33 #endif |
| 34 #ifdef HAVE_ZLIB_H |
| 35 #include <zlib.h> |
| 36 #endif |
| 37 #include <lzma.h> |
| 38 |
| 39 #include "xzlib.h" |
| 40 #include <libxml/xmlmemory.h> |
| 41 |
| 42 /* values for xz_state how */ |
| 43 #define LOOK 0 /* look for a gzip/lzma header */ |
| 44 #define COPY 1 /* copy input directly */ |
| 45 #define GZIP 2 /* decompress a gzip stream */ |
| 46 #define LZMA 3 /* decompress a lzma stream */ |
| 47 |
| 48 /* internal lzma file state data structure */ |
| 49 typedef struct { |
| 50 int mode; /* see lzma modes above */ |
| 51 int fd; /* file descriptor */ |
| 52 char *path; /* path or fd for error messages */ |
| 53 uint64_t pos; /* current position in uncompressed data */ |
| 54 unsigned int size; /* buffer size, zero if not allocated yet */ |
| 55 unsigned int want; /* requested buffer size, default is BUFSIZ */ |
| 56 unsigned char *in; /* input buffer */ |
| 57 unsigned char *out; /* output buffer (double-sized when reading) */ |
| 58 unsigned char *next; /* next output data to deliver or write */ |
| 59 unsigned int have; /* amount of output data unused at next */ |
| 60 int eof; /* true if end of input file reached */ |
| 61 uint64_t start; /* where the lzma data started, for rewinding */ |
| 62 uint64_t raw; /* where the raw data started, for seeking */ |
| 63 int how; /* 0: get header, 1: copy, 2: decompress */ |
| 64 int direct; /* true if last read direct, false if lzma */ |
| 65 /* seek request */ |
| 66 uint64_t skip; /* amount to skip (already rewound if backwards)
*/ |
| 67 int seek; /* true if seek request pending */ |
| 68 /* error information */ |
| 69 int err; /* error code */ |
| 70 char *msg; /* error message */ |
| 71 /* lzma stream */ |
| 72 int init; /* is the iniflate stream initialized */ |
| 73 lzma_stream strm; /* stream structure in-place (not a pointer) */ |
| 74 char padding1[32]; /* padding allowing to cope with possible |
| 75 extensions of above structure without |
| 76 too much side effect */ |
| 77 #ifdef HAVE_ZLIB_H |
| 78 /* zlib inflate or deflate stream */ |
| 79 z_stream zstrm; /* stream structure in-place (not a pointer) */ |
| 80 #endif |
| 81 char padding2[32]; /* padding allowing to cope with possible |
| 82 extensions of above structure without |
| 83 too much side effect */ |
| 84 } xz_state, *xz_statep; |
| 85 |
| 86 static void |
| 87 xz_error(xz_statep state, int err, const char *msg) |
| 88 { |
| 89 /* free previously allocated message and clear */ |
| 90 if (state->msg != NULL) { |
| 91 if (state->err != LZMA_MEM_ERROR) |
| 92 xmlFree(state->msg); |
| 93 state->msg = NULL; |
| 94 } |
| 95 |
| 96 /* set error code, and if no message, then done */ |
| 97 state->err = err; |
| 98 if (msg == NULL) |
| 99 return; |
| 100 |
| 101 /* for an out of memory error, save as static string */ |
| 102 if (err == LZMA_MEM_ERROR) { |
| 103 state->msg = (char *) msg; |
| 104 return; |
| 105 } |
| 106 |
| 107 /* construct error message with path */ |
| 108 if ((state->msg = |
| 109 xmlMalloc(strlen(state->path) + strlen(msg) + 3)) == NULL) { |
| 110 state->err = LZMA_MEM_ERROR; |
| 111 state->msg = (char *) "out of memory"; |
| 112 return; |
| 113 } |
| 114 strcpy(state->msg, state->path); |
| 115 strcat(state->msg, ": "); |
| 116 strcat(state->msg, msg); |
| 117 return; |
| 118 } |
| 119 |
| 120 static void |
| 121 xz_reset(xz_statep state) |
| 122 { |
| 123 state->have = 0; /* no output data available */ |
| 124 state->eof = 0; /* not at end of file */ |
| 125 state->how = LOOK; /* look for gzip header */ |
| 126 state->direct = 1; /* default for empty file */ |
| 127 state->seek = 0; /* no seek request pending */ |
| 128 xz_error(state, LZMA_OK, NULL); /* clear error */ |
| 129 state->pos = 0; /* no uncompressed data yet */ |
| 130 state->strm.avail_in = 0; /* no input data yet */ |
| 131 #ifdef HAVE_ZLIB_H |
| 132 state->zstrm.avail_in = 0; /* no input data yet */ |
| 133 #endif |
| 134 } |
| 135 |
| 136 static xzFile |
| 137 xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED) |
| 138 { |
| 139 xz_statep state; |
| 140 |
| 141 /* allocate xzFile structure to return */ |
| 142 state = xmlMalloc(sizeof(xz_state)); |
| 143 if (state == NULL) |
| 144 return NULL; |
| 145 state->size = 0; /* no buffers allocated yet */ |
| 146 state->want = BUFSIZ; /* requested buffer size */ |
| 147 state->msg = NULL; /* no error message yet */ |
| 148 state->init = 0; /* initialization of zlib data */ |
| 149 |
| 150 /* save the path name for error messages */ |
| 151 state->path = xmlMalloc(strlen(path) + 1); |
| 152 if (state->path == NULL) { |
| 153 xmlFree(state); |
| 154 return NULL; |
| 155 } |
| 156 strcpy(state->path, path); |
| 157 |
| 158 /* open the file with the appropriate mode (or just use fd) */ |
| 159 state->fd = fd != -1 ? fd : open(path, |
| 160 #ifdef O_LARGEFILE |
| 161 O_LARGEFILE | |
| 162 #endif |
| 163 #ifdef O_BINARY |
| 164 O_BINARY | |
| 165 #endif |
| 166 O_RDONLY, 0666); |
| 167 if (state->fd == -1) { |
| 168 xmlFree(state->path); |
| 169 xmlFree(state); |
| 170 return NULL; |
| 171 } |
| 172 |
| 173 /* save the current position for rewinding (only if reading) */ |
| 174 state->start = lseek(state->fd, 0, SEEK_CUR); |
| 175 if (state->start == (uint64_t) - 1) |
| 176 state->start = 0; |
| 177 |
| 178 /* initialize stream */ |
| 179 xz_reset(state); |
| 180 |
| 181 /* return stream */ |
| 182 return (xzFile) state; |
| 183 } |
| 184 |
| 185 static int |
| 186 xz_compressed(xzFile f) { |
| 187 xz_statep state; |
| 188 |
| 189 if (f == NULL) |
| 190 return(-1); |
| 191 state = (xz_statep) f; |
| 192 if (state->init <= 0) |
| 193 return(-1); |
| 194 |
| 195 switch (state->how) { |
| 196 case COPY: |
| 197 return(0); |
| 198 case GZIP: |
| 199 case LZMA: |
| 200 return(1); |
| 201 } |
| 202 return(-1); |
| 203 } |
| 204 |
| 205 xzFile |
| 206 __libxml2_xzopen(const char *path, const char *mode) |
| 207 { |
| 208 return xz_open(path, -1, mode); |
| 209 } |
| 210 |
| 211 int |
| 212 __libxml2_xzcompressed(xzFile f) { |
| 213 return xz_compressed(f); |
| 214 } |
| 215 |
| 216 xzFile |
| 217 __libxml2_xzdopen(int fd, const char *mode) |
| 218 { |
| 219 char *path; /* identifier for error messages */ |
| 220 xzFile xz; |
| 221 |
| 222 if (fd == -1 || (path = xmlMalloc(7 + 3 * sizeof(int))) == NULL) |
| 223 return NULL; |
| 224 sprintf(path, "<fd:%d>", fd); /* for debugging */ |
| 225 xz = xz_open(path, fd, mode); |
| 226 xmlFree(path); |
| 227 return xz; |
| 228 } |
| 229 |
| 230 static int |
| 231 xz_load(xz_statep state, unsigned char *buf, unsigned int len, |
| 232 unsigned int *have) |
| 233 { |
| 234 int ret; |
| 235 |
| 236 *have = 0; |
| 237 do { |
| 238 ret = read(state->fd, buf + *have, len - *have); |
| 239 if (ret <= 0) |
| 240 break; |
| 241 *have += ret; |
| 242 } while (*have < len); |
| 243 if (ret < 0) { |
| 244 xz_error(state, -1, strerror(errno)); |
| 245 return -1; |
| 246 } |
| 247 if (ret == 0) |
| 248 state->eof = 1; |
| 249 return 0; |
| 250 } |
| 251 |
| 252 static int |
| 253 xz_avail(xz_statep state) |
| 254 { |
| 255 lzma_stream *strm = &(state->strm); |
| 256 |
| 257 if (state->err != LZMA_OK) |
| 258 return -1; |
| 259 if (state->eof == 0) { |
| 260 /* avail_in is size_t, which is not necessary sizeof(unsigned) */ |
| 261 unsigned tmp = strm->avail_in; |
| 262 |
| 263 if (xz_load(state, state->in, state->size, &tmp) == -1) { |
| 264 strm->avail_in = tmp; |
| 265 return -1; |
| 266 } |
| 267 strm->avail_in = tmp; |
| 268 strm->next_in = state->in; |
| 269 } |
| 270 return 0; |
| 271 } |
| 272 |
| 273 #ifdef HAVE_ZLIB_H |
| 274 static int |
| 275 xz_avail_zstrm(xz_statep state) |
| 276 { |
| 277 int ret; |
| 278 state->strm.avail_in = state->zstrm.avail_in; |
| 279 state->strm.next_in = state->zstrm.next_in; |
| 280 ret = xz_avail(state); |
| 281 state->zstrm.avail_in = (uInt) state->strm.avail_in; |
| 282 state->zstrm.next_in = (Bytef *) state->strm.next_in; |
| 283 return ret; |
| 284 } |
| 285 #endif |
| 286 |
| 287 static int |
| 288 is_format_xz(xz_statep state) |
| 289 { |
| 290 lzma_stream *strm = &(state->strm); |
| 291 |
| 292 return strm->avail_in >= 6 && memcmp(state->in, "\3757zXZ", 6) == 0; |
| 293 } |
| 294 |
| 295 static int |
| 296 is_format_lzma(xz_statep state) |
| 297 { |
| 298 lzma_stream *strm = &(state->strm); |
| 299 |
| 300 lzma_filter filter; |
| 301 lzma_options_lzma *opt; |
| 302 uint32_t dict_size; |
| 303 uint64_t uncompressed_size; |
| 304 size_t i; |
| 305 |
| 306 if (strm->avail_in < 13) |
| 307 return 0; |
| 308 |
| 309 filter.id = LZMA_FILTER_LZMA1; |
| 310 if (lzma_properties_decode(&filter, NULL, state->in, 5) != LZMA_OK) |
| 311 return 0; |
| 312 |
| 313 opt = filter.options; |
| 314 dict_size = opt->dict_size; |
| 315 free(opt); /* we can't use xmlFree on a string returned by zlib */ |
| 316 |
| 317 /* A hack to ditch tons of false positives: We allow only dictionary |
| 318 * sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone |
| 319 * created only files with 2^n, but accepts any dictionary size. |
| 320 * If someone complains, this will be reconsidered. |
| 321 */ |
| 322 if (dict_size != UINT32_MAX) { |
| 323 uint32_t d = dict_size - 1; |
| 324 |
| 325 d |= d >> 2; |
| 326 d |= d >> 3; |
| 327 d |= d >> 4; |
| 328 d |= d >> 8; |
| 329 d |= d >> 16; |
| 330 ++d; |
| 331 if (d != dict_size || dict_size == 0) |
| 332 return 0; |
| 333 } |
| 334 |
| 335 /* Another hack to ditch false positives: Assume that if the |
| 336 * uncompressed size is known, it must be less than 256 GiB. |
| 337 * Again, if someone complains, this will be reconsidered. |
| 338 */ |
| 339 uncompressed_size = 0; |
| 340 for (i = 0; i < 8; ++i) |
| 341 uncompressed_size |= (uint64_t) (state->in[5 + i]) << (i * 8); |
| 342 |
| 343 if (uncompressed_size != UINT64_MAX |
| 344 && uncompressed_size > (UINT64_C(1) << 38)) |
| 345 return 0; |
| 346 |
| 347 return 1; |
| 348 } |
| 349 |
| 350 #ifdef HAVE_ZLIB_H |
| 351 |
| 352 /* Get next byte from input, or -1 if end or error. */ |
| 353 #define NEXT() ((strm->avail_in == 0 && xz_avail(state) == -1) ? -1 : \ |
| 354 (strm->avail_in == 0 ? -1 : \ |
| 355 (strm->avail_in--, *(strm->next_in)++))) |
| 356 /* Same thing, but from zstrm */ |
| 357 #define NEXTZ() ((strm->avail_in == 0 && xz_avail_zstrm(state) == -1) ? -1 : \ |
| 358 (strm->avail_in == 0 ? -1 : \ |
| 359 (strm->avail_in--, *(strm->next_in)++))) |
| 360 |
| 361 /* Get a four-byte little-endian integer and return 0 on success and the value |
| 362 in *ret. Otherwise -1 is returned and *ret is not modified. */ |
| 363 static int |
| 364 gz_next4(xz_statep state, unsigned long *ret) |
| 365 { |
| 366 int ch; |
| 367 unsigned long val; |
| 368 z_streamp strm = &(state->zstrm); |
| 369 |
| 370 val = NEXTZ(); |
| 371 val += (unsigned) NEXTZ() << 8; |
| 372 val += (unsigned long) NEXTZ() << 16; |
| 373 ch = NEXTZ(); |
| 374 if (ch == -1) |
| 375 return -1; |
| 376 val += (unsigned long) ch << 24; |
| 377 *ret = val; |
| 378 return 0; |
| 379 } |
| 380 #endif |
| 381 |
| 382 static int |
| 383 xz_head(xz_statep state) |
| 384 { |
| 385 lzma_stream *strm = &(state->strm); |
| 386 lzma_stream init = LZMA_STREAM_INIT; |
| 387 int flags; |
| 388 unsigned len; |
| 389 |
| 390 /* allocate read buffers and inflate memory */ |
| 391 if (state->size == 0) { |
| 392 /* allocate buffers */ |
| 393 state->in = xmlMalloc(state->want); |
| 394 state->out = xmlMalloc(state->want << 1); |
| 395 if (state->in == NULL || state->out == NULL) { |
| 396 if (state->out != NULL) |
| 397 xmlFree(state->out); |
| 398 if (state->in != NULL) |
| 399 xmlFree(state->in); |
| 400 xz_error(state, LZMA_MEM_ERROR, "out of memory"); |
| 401 return -1; |
| 402 } |
| 403 state->size = state->want; |
| 404 |
| 405 /* allocate decoder memory */ |
| 406 state->strm = init; |
| 407 state->strm.avail_in = 0; |
| 408 state->strm.next_in = NULL; |
| 409 if (lzma_auto_decoder(&state->strm, UINT64_MAX, 0) != LZMA_OK) { |
| 410 xmlFree(state->out); |
| 411 xmlFree(state->in); |
| 412 state->size = 0; |
| 413 xz_error(state, LZMA_MEM_ERROR, "out of memory"); |
| 414 return -1; |
| 415 } |
| 416 #ifdef HAVE_ZLIB_H |
| 417 /* allocate inflate memory */ |
| 418 state->zstrm.zalloc = Z_NULL; |
| 419 state->zstrm.zfree = Z_NULL; |
| 420 state->zstrm.opaque = Z_NULL; |
| 421 state->zstrm.avail_in = 0; |
| 422 state->zstrm.next_in = Z_NULL; |
| 423 if (state->init == 0) { |
| 424 if (inflateInit2(&(state->zstrm), -15) != Z_OK) {/* raw inflate */ |
| 425 xmlFree(state->out); |
| 426 xmlFree(state->in); |
| 427 state->size = 0; |
| 428 xz_error(state, LZMA_MEM_ERROR, "out of memory"); |
| 429 return -1; |
| 430 } |
| 431 state->init = 1; |
| 432 } |
| 433 #endif |
| 434 } |
| 435 |
| 436 /* get some data in the input buffer */ |
| 437 if (strm->avail_in == 0) { |
| 438 if (xz_avail(state) == -1) |
| 439 return -1; |
| 440 if (strm->avail_in == 0) |
| 441 return 0; |
| 442 } |
| 443 |
| 444 /* look for the xz magic header bytes */ |
| 445 if (is_format_xz(state) || is_format_lzma(state)) { |
| 446 state->how = LZMA; |
| 447 state->direct = 0; |
| 448 return 0; |
| 449 } |
| 450 #ifdef HAVE_ZLIB_H |
| 451 /* look for the gzip magic header bytes 31 and 139 */ |
| 452 if (strm->next_in[0] == 31) { |
| 453 strm->avail_in--; |
| 454 strm->next_in++; |
| 455 if (strm->avail_in == 0 && xz_avail(state) == -1) |
| 456 return -1; |
| 457 if (strm->avail_in && strm->next_in[0] == 139) { |
| 458 /* we have a gzip header, woo hoo! */ |
| 459 strm->avail_in--; |
| 460 strm->next_in++; |
| 461 |
| 462 /* skip rest of header */ |
| 463 if (NEXT() != 8) { /* compression method */ |
| 464 xz_error(state, LZMA_DATA_ERROR, |
| 465 "unknown compression method"); |
| 466 return -1; |
| 467 } |
| 468 flags = NEXT(); |
| 469 if (flags & 0xe0) { /* reserved flag bits */ |
| 470 xz_error(state, LZMA_DATA_ERROR, |
| 471 "unknown header flags set"); |
| 472 return -1; |
| 473 } |
| 474 NEXT(); /* modification time */ |
| 475 NEXT(); |
| 476 NEXT(); |
| 477 NEXT(); |
| 478 NEXT(); /* extra flags */ |
| 479 NEXT(); /* operating system */ |
| 480 if (flags & 4) { /* extra field */ |
| 481 len = (unsigned) NEXT(); |
| 482 len += (unsigned) NEXT() << 8; |
| 483 while (len--) |
| 484 if (NEXT() < 0) |
| 485 break; |
| 486 } |
| 487 if (flags & 8) /* file name */ |
| 488 while (NEXT() > 0) ; |
| 489 if (flags & 16) /* comment */ |
| 490 while (NEXT() > 0) ; |
| 491 if (flags & 2) { /* header crc */ |
| 492 NEXT(); |
| 493 NEXT(); |
| 494 } |
| 495 /* an unexpected end of file is not checked for here -- it will be |
| 496 * noticed on the first request for uncompressed data */ |
| 497 |
| 498 /* set up for decompression */ |
| 499 inflateReset(&state->zstrm); |
| 500 state->zstrm.adler = crc32(0L, Z_NULL, 0); |
| 501 state->how = GZIP; |
| 502 state->direct = 0; |
| 503 return 0; |
| 504 } else { |
| 505 /* not a gzip file -- save first byte (31) and fall to raw i/o */ |
| 506 state->out[0] = 31; |
| 507 state->have = 1; |
| 508 } |
| 509 } |
| 510 #endif |
| 511 |
| 512 /* doing raw i/o, save start of raw data for seeking, copy any leftover |
| 513 * input to output -- this assumes that the output buffer is larger than |
| 514 * the input buffer, which also assures space for gzungetc() */ |
| 515 state->raw = state->pos; |
| 516 state->next = state->out; |
| 517 if (strm->avail_in) { |
| 518 memcpy(state->next + state->have, strm->next_in, strm->avail_in); |
| 519 state->have += strm->avail_in; |
| 520 strm->avail_in = 0; |
| 521 } |
| 522 state->how = COPY; |
| 523 state->direct = 1; |
| 524 return 0; |
| 525 } |
| 526 |
| 527 static int |
| 528 xz_decomp(xz_statep state) |
| 529 { |
| 530 int ret; |
| 531 unsigned had; |
| 532 unsigned long crc, len; |
| 533 lzma_stream *strm = &(state->strm); |
| 534 |
| 535 lzma_action action = LZMA_RUN; |
| 536 |
| 537 /* fill output buffer up to end of deflate stream */ |
| 538 had = strm->avail_out; |
| 539 do { |
| 540 /* get more input for inflate() */ |
| 541 if (strm->avail_in == 0 && xz_avail(state) == -1) |
| 542 return -1; |
| 543 if (strm->avail_in == 0) { |
| 544 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file"); |
| 545 return -1; |
| 546 } |
| 547 if (state->eof) |
| 548 action = LZMA_FINISH; |
| 549 |
| 550 /* decompress and handle errors */ |
| 551 #ifdef HAVE_ZLIB_H |
| 552 if (state->how == GZIP) { |
| 553 state->zstrm.avail_in = (uInt) state->strm.avail_in; |
| 554 state->zstrm.next_in = (Bytef *) state->strm.next_in; |
| 555 state->zstrm.avail_out = (uInt) state->strm.avail_out; |
| 556 state->zstrm.next_out = (Bytef *) state->strm.next_out; |
| 557 ret = inflate(&state->zstrm, Z_NO_FLUSH); |
| 558 if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) { |
| 559 xz_error(state, Z_STREAM_ERROR, |
| 560 "internal error: inflate stream corrupt"); |
| 561 return -1; |
| 562 } |
| 563 if (ret == Z_MEM_ERROR) |
| 564 ret = LZMA_MEM_ERROR; |
| 565 if (ret == Z_DATA_ERROR) |
| 566 ret = LZMA_DATA_ERROR; |
| 567 if (ret == Z_STREAM_END) |
| 568 ret = LZMA_STREAM_END; |
| 569 state->strm.avail_in = state->zstrm.avail_in; |
| 570 state->strm.next_in = state->zstrm.next_in; |
| 571 state->strm.avail_out = state->zstrm.avail_out; |
| 572 state->strm.next_out = state->zstrm.next_out; |
| 573 } else /* state->how == LZMA */ |
| 574 #endif |
| 575 ret = lzma_code(strm, action); |
| 576 if (ret == LZMA_MEM_ERROR) { |
| 577 xz_error(state, LZMA_MEM_ERROR, "out of memory"); |
| 578 return -1; |
| 579 } |
| 580 if (ret == LZMA_DATA_ERROR) { |
| 581 xz_error(state, LZMA_DATA_ERROR, "compressed data error"); |
| 582 return -1; |
| 583 } |
| 584 } while (strm->avail_out && ret != LZMA_STREAM_END); |
| 585 |
| 586 /* update available output and crc check value */ |
| 587 state->have = had - strm->avail_out; |
| 588 state->next = strm->next_out - state->have; |
| 589 #ifdef HAVE_ZLIB_H |
| 590 state->zstrm.adler = |
| 591 crc32(state->zstrm.adler, state->next, state->have); |
| 592 #endif |
| 593 |
| 594 if (ret == LZMA_STREAM_END) { |
| 595 #ifdef HAVE_ZLIB_H |
| 596 if (state->how == GZIP) { |
| 597 if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) { |
| 598 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file"); |
| 599 return -1; |
| 600 } |
| 601 if (crc != state->zstrm.adler) { |
| 602 xz_error(state, LZMA_DATA_ERROR, "incorrect data check"); |
| 603 return -1; |
| 604 } |
| 605 if (len != (state->zstrm.total_out & 0xffffffffL)) { |
| 606 xz_error(state, LZMA_DATA_ERROR, "incorrect length check"); |
| 607 return -1; |
| 608 } |
| 609 state->strm.avail_in = 0; |
| 610 state->strm.next_in = NULL; |
| 611 state->strm.avail_out = 0; |
| 612 state->strm.next_out = NULL; |
| 613 } else |
| 614 #endif |
| 615 if (strm->avail_in != 0 || !state->eof) { |
| 616 xz_error(state, LZMA_DATA_ERROR, "trailing garbage"); |
| 617 return -1; |
| 618 } |
| 619 state->how = LOOK; /* ready for next stream, once have is 0 (leave |
| 620 * state->direct unchanged to remember how) */ |
| 621 } |
| 622 |
| 623 /* good decompression */ |
| 624 return 0; |
| 625 } |
| 626 |
| 627 static int |
| 628 xz_make(xz_statep state) |
| 629 { |
| 630 lzma_stream *strm = &(state->strm); |
| 631 |
| 632 if (state->how == LOOK) { /* look for lzma / gzip header */ |
| 633 if (xz_head(state) == -1) |
| 634 return -1; |
| 635 if (state->have) /* got some data from xz_head() */ |
| 636 return 0; |
| 637 } |
| 638 if (state->how == COPY) { /* straight copy */ |
| 639 if (xz_load(state, state->out, state->size << 1, &(state->have)) == |
| 640 -1) |
| 641 return -1; |
| 642 state->next = state->out; |
| 643 } else if (state->how == LZMA || state->how == GZIP) { /* decompress */ |
| 644 strm->avail_out = state->size << 1; |
| 645 strm->next_out = state->out; |
| 646 if (xz_decomp(state) == -1) |
| 647 return -1; |
| 648 } |
| 649 return 0; |
| 650 } |
| 651 |
| 652 static int |
| 653 xz_skip(xz_statep state, uint64_t len) |
| 654 { |
| 655 unsigned n; |
| 656 |
| 657 /* skip over len bytes or reach end-of-file, whichever comes first */ |
| 658 while (len) |
| 659 /* skip over whatever is in output buffer */ |
| 660 if (state->have) { |
| 661 n = (uint64_t) state->have > len ? |
| 662 (unsigned) len : state->have; |
| 663 state->have -= n; |
| 664 state->next += n; |
| 665 state->pos += n; |
| 666 len -= n; |
| 667 } |
| 668 |
| 669 /* output buffer empty -- return if we're at the end of the input */ |
| 670 else if (state->eof && state->strm.avail_in == 0) |
| 671 break; |
| 672 |
| 673 /* need more data to skip -- load up output buffer */ |
| 674 else { |
| 675 /* get more output, looking for header if required */ |
| 676 if (xz_make(state) == -1) |
| 677 return -1; |
| 678 } |
| 679 return 0; |
| 680 } |
| 681 |
| 682 int |
| 683 __libxml2_xzread(xzFile file, void *buf, unsigned len) |
| 684 { |
| 685 unsigned got, n; |
| 686 xz_statep state; |
| 687 lzma_stream *strm; |
| 688 |
| 689 /* get internal structure */ |
| 690 if (file == NULL) |
| 691 return -1; |
| 692 state = (xz_statep) file; |
| 693 strm = &(state->strm); |
| 694 |
| 695 /* check that we're reading and that there's no error */ |
| 696 if (state->err != LZMA_OK) |
| 697 return -1; |
| 698 |
| 699 /* since an int is returned, make sure len fits in one, otherwise return |
| 700 * with an error (this avoids the flaw in the interface) */ |
| 701 if ((int) len < 0) { |
| 702 xz_error(state, LZMA_BUF_ERROR, |
| 703 "requested length does not fit in int"); |
| 704 return -1; |
| 705 } |
| 706 |
| 707 /* if len is zero, avoid unnecessary operations */ |
| 708 if (len == 0) |
| 709 return 0; |
| 710 |
| 711 /* process a skip request */ |
| 712 if (state->seek) { |
| 713 state->seek = 0; |
| 714 if (xz_skip(state, state->skip) == -1) |
| 715 return -1; |
| 716 } |
| 717 |
| 718 /* get len bytes to buf, or less than len if at the end */ |
| 719 got = 0; |
| 720 do { |
| 721 /* first just try copying data from the output buffer */ |
| 722 if (state->have) { |
| 723 n = state->have > len ? len : state->have; |
| 724 memcpy(buf, state->next, n); |
| 725 state->next += n; |
| 726 state->have -= n; |
| 727 } |
| 728 |
| 729 /* output buffer empty -- return if we're at the end of the input */ |
| 730 else if (state->eof && strm->avail_in == 0) |
| 731 break; |
| 732 |
| 733 /* need output data -- for small len or new stream load up our output |
| 734 * buffer */ |
| 735 else if (state->how == LOOK || len < (state->size << 1)) { |
| 736 /* get more output, looking for header if required */ |
| 737 if (xz_make(state) == -1) |
| 738 return -1; |
| 739 continue; /* no progress yet -- go back to memcpy() above
*/ |
| 740 /* the copy above assures that we will leave with space in the |
| 741 * output buffer, allowing at least one gzungetc() to succeed */ |
| 742 } |
| 743 |
| 744 /* large len -- read directly into user buffer */ |
| 745 else if (state->how == COPY) { /* read directly */ |
| 746 if (xz_load(state, buf, len, &n) == -1) |
| 747 return -1; |
| 748 } |
| 749 |
| 750 /* large len -- decompress directly into user buffer */ |
| 751 else { /* state->how == LZMA */ |
| 752 strm->avail_out = len; |
| 753 strm->next_out = buf; |
| 754 if (xz_decomp(state) == -1) |
| 755 return -1; |
| 756 n = state->have; |
| 757 state->have = 0; |
| 758 } |
| 759 |
| 760 /* update progress */ |
| 761 len -= n; |
| 762 buf = (char *) buf + n; |
| 763 got += n; |
| 764 state->pos += n; |
| 765 } while (len); |
| 766 |
| 767 /* return number of bytes read into user buffer (will fit in int) */ |
| 768 return (int) got; |
| 769 } |
| 770 |
| 771 int |
| 772 __libxml2_xzclose(xzFile file) |
| 773 { |
| 774 int ret; |
| 775 xz_statep state; |
| 776 |
| 777 /* get internal structure */ |
| 778 if (file == NULL) |
| 779 return LZMA_DATA_ERROR; |
| 780 state = (xz_statep) file; |
| 781 |
| 782 /* free memory and close file */ |
| 783 if (state->size) { |
| 784 lzma_end(&(state->strm)); |
| 785 #ifdef HAVE_ZLIB_H |
| 786 if (state->init == 1) |
| 787 inflateEnd(&(state->zstrm)); |
| 788 state->init = 0; |
| 789 #endif |
| 790 xmlFree(state->out); |
| 791 xmlFree(state->in); |
| 792 } |
| 793 xmlFree(state->path); |
| 794 ret = close(state->fd); |
| 795 xmlFree(state); |
| 796 return ret ? ret : LZMA_OK; |
| 797 } |
| 798 #endif /* HAVE_LZMA_H */ |
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