xzlib.c
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 LIBXML_LZMA_ENABLED 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 #ifdef HAVE_LZMA_H 38 #include <lzma.h> 39 #endif 40 41 #include "xzlib.h" 42 #include <libxml/xmlmemory.h> 43 44 /* values for xz_state how */ 45 #define LOOK 0 /* look for a gzip/lzma header */ 46 #define COPY 1 /* copy input directly */ 47 #define GZIP 2 /* decompress a gzip stream */ 48 #define LZMA 3 /* decompress a lzma stream */ 49 50 /* internal lzma file state data structure */ 51 typedef struct { 52 int mode; /* see lzma modes above */ 53 int fd; /* file descriptor */ 54 char *path; /* path or fd for error messages */ 55 uint64_t pos; /* current position in uncompressed data */ 56 unsigned int size; /* buffer size, zero if not allocated yet */ 57 unsigned int want; /* requested buffer size, default is BUFSIZ */ 58 unsigned char *in; /* input buffer */ 59 unsigned char *out; /* output buffer (double-sized when reading) */ 60 unsigned char *next; /* next output data to deliver or write */ 61 unsigned int have; /* amount of output data unused at next */ 62 int eof; /* true if end of input file reached */ 63 uint64_t start; /* where the lzma data started, for rewinding */ 64 uint64_t raw; /* where the raw data started, for seeking */ 65 int how; /* 0: get header, 1: copy, 2: decompress */ 66 int direct; /* true if last read direct, false if lzma */ 67 /* seek request */ 68 uint64_t skip; /* amount to skip (already rewound if backwards) */ 69 int seek; /* true if seek request pending */ 70 /* error information */ 71 int err; /* error code */ 72 char *msg; /* error message */ 73 /* lzma stream */ 74 int init; /* is the iniflate stream initialized */ 75 lzma_stream strm; /* stream structure in-place (not a pointer) */ 76 char padding1[32]; /* padding allowing to cope with possible 77 extensions of above structure without 78 too much side effect */ 79 #ifdef HAVE_ZLIB_H 80 /* zlib inflate or deflate stream */ 81 z_stream zstrm; /* stream structure in-place (not a pointer) */ 82 #endif 83 char padding2[32]; /* padding allowing to cope with possible 84 extensions of above structure without 85 too much side effect */ 86 } xz_state, *xz_statep; 87 88 static void 89 xz_error(xz_statep state, int err, const char *msg) 90 { 91 /* free previously allocated message and clear */ 92 if (state->msg != NULL) { 93 if (state->err != LZMA_MEM_ERROR) 94 xmlFree(state->msg); 95 state->msg = NULL; 96 } 97 98 /* set error code, and if no message, then done */ 99 state->err = err; 100 if (msg == NULL) 101 return; 102 103 /* for an out of memory error, save as static string */ 104 if (err == LZMA_MEM_ERROR) { 105 state->msg = (char *) msg; 106 return; 107 } 108 109 /* construct error message with path */ 110 { 111 const size_t msgLength = strlen(state->path) + 2 + strlen(msg) + 1; 112 if ((state->msg = xmlMalloc(msgLength)) == NULL) { 113 state->err = LZMA_MEM_ERROR; 114 state->msg = (char *) "out of memory"; 115 return; 116 } 117 snprintf(state->msg, msgLength, "%s: %s", state->path, msg); 118 } 119 return; 120 } 121 122 static void 123 xz_reset(xz_statep state) 124 { 125 state->have = 0; /* no output data available */ 126 state->eof = 0; /* not at end of file */ 127 state->how = LOOK; /* look for gzip header */ 128 state->direct = 1; /* default for empty file */ 129 state->seek = 0; /* no seek request pending */ 130 xz_error(state, LZMA_OK, NULL); /* clear error */ 131 state->pos = 0; /* no uncompressed data yet */ 132 state->strm.avail_in = 0; /* no input data yet */ 133 #ifdef HAVE_ZLIB_H 134 state->zstrm.avail_in = 0; /* no input data yet */ 135 #endif 136 } 137 138 static xzFile 139 xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED) 140 { 141 const size_t pathLength = strlen(path) + 1; 142 xz_statep state; 143 144 /* allocate xzFile structure to return */ 145 state = xmlMalloc(sizeof(xz_state)); 146 if (state == NULL) 147 return NULL; 148 state->size = 0; /* no buffers allocated yet */ 149 state->want = BUFSIZ; /* requested buffer size */ 150 state->msg = NULL; /* no error message yet */ 151 state->init = 0; /* initialization of zlib data */ 152 153 /* save the path name for error messages */ 154 state->path = xmlMalloc(pathLength); 155 if (state->path == NULL) { 156 xmlFree(state); 157 return NULL; 158 } 159 strncpy(state->path, path, pathLength); 160 state->path[pathLength - 1] = '\0'; 161 162 /* open the file with the appropriate mode (or just use fd) */ 163 state->fd = fd != -1 ? fd : open(path, 164 #ifdef O_LARGEFILE 165 O_LARGEFILE | 166 #endif 167 #ifdef O_BINARY 168 O_BINARY | 169 #endif 170 O_RDONLY, 0666); 171 if (state->fd == -1) { 172 xmlFree(state->path); 173 xmlFree(state); 174 return NULL; 175 } 176 177 /* save the current position for rewinding (only if reading) */ 178 state->start = lseek(state->fd, 0, SEEK_CUR); 179 if (state->start == (uint64_t) - 1) 180 state->start = 0; 181 182 /* initialize stream */ 183 xz_reset(state); 184 185 /* return stream */ 186 return (xzFile) state; 187 } 188 189 static int 190 xz_compressed(xzFile f) { 191 xz_statep state; 192 193 if (f == NULL) 194 return(-1); 195 state = (xz_statep) f; 196 if (state->init <= 0) 197 return(-1); 198 199 switch (state->how) { 200 case COPY: 201 return(0); 202 case GZIP: 203 case LZMA: 204 return(1); 205 } 206 return(-1); 207 } 208 209 xzFile 210 __libxml2_xzopen(const char *path, const char *mode) 211 { 212 return xz_open(path, -1, mode); 213 } 214 215 int 216 __libxml2_xzcompressed(xzFile f) { 217 return xz_compressed(f); 218 } 219 220 xzFile 221 __libxml2_xzdopen(int fd, const char *mode) 222 { 223 char *path; /* identifier for error messages */ 224 xzFile xz; 225 size_t pathLength = 7 + (3 * sizeof(int)) + 1; 226 227 if (fd == -1 || (path = xmlMalloc(pathLength)) == NULL) 228 return NULL; 229 snprintf(path, pathLength, "<fd:%d>", fd); /* for debugging */ 230 xz = xz_open(path, fd, mode); 231 xmlFree(path); 232 return xz; 233 } 234 235 static int 236 xz_load(xz_statep state, unsigned char *buf, unsigned int len, 237 unsigned int *have) 238 { 239 int ret; 240 241 *have = 0; 242 do { 243 ret = read(state->fd, buf + *have, len - *have); 244 if (ret <= 0) 245 break; 246 *have += ret; 247 } while (*have < len); 248 if (ret < 0) { 249 xz_error(state, -1, strerror(errno)); 250 return -1; 251 } 252 if (ret == 0) 253 state->eof = 1; 254 return 0; 255 } 256 257 static int 258 xz_avail(xz_statep state) 259 { 260 lzma_stream *strm = &(state->strm); 261 262 if (state->err != LZMA_OK) 263 return -1; 264 if (state->eof == 0) { 265 /* avail_in is size_t, which is not necessary sizeof(unsigned) */ 266 unsigned tmp = strm->avail_in; 267 268 if (xz_load(state, state->in, state->size, &tmp) == -1) { 269 strm->avail_in = tmp; 270 return -1; 271 } 272 strm->avail_in = tmp; 273 strm->next_in = state->in; 274 } 275 return 0; 276 } 277 278 #ifdef HAVE_ZLIB_H 279 static int 280 xz_avail_zstrm(xz_statep state) 281 { 282 int ret; 283 state->strm.avail_in = state->zstrm.avail_in; 284 state->strm.next_in = state->zstrm.next_in; 285 ret = xz_avail(state); 286 state->zstrm.avail_in = (uInt) state->strm.avail_in; 287 state->zstrm.next_in = (Bytef *) state->strm.next_in; 288 return ret; 289 } 290 #endif 291 292 static int 293 is_format_xz(xz_statep state) 294 { 295 lzma_stream *strm = &(state->strm); 296 297 return strm->avail_in >= 6 && memcmp(state->in, "\3757zXZ", 6) == 0; 298 } 299 300 static int 301 is_format_lzma(xz_statep state) 302 { 303 lzma_stream *strm = &(state->strm); 304 305 lzma_filter filter; 306 lzma_options_lzma *opt; 307 uint32_t dict_size; 308 uint64_t uncompressed_size; 309 size_t i; 310 311 if (strm->avail_in < 13) 312 return 0; 313 314 filter.id = LZMA_FILTER_LZMA1; 315 if (lzma_properties_decode(&filter, NULL, state->in, 5) != LZMA_OK) 316 return 0; 317 318 opt = filter.options; 319 dict_size = opt->dict_size; 320 free(opt); /* we can't use xmlFree on a string returned by zlib */ 321 322 /* A hack to ditch tons of false positives: We allow only dictionary 323 * sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone 324 * created only files with 2^n, but accepts any dictionary size. 325 * If someone complains, this will be reconsidered. 326 */ 327 if (dict_size != UINT32_MAX) { 328 uint32_t d = dict_size - 1; 329 330 d |= d >> 2; 331 d |= d >> 3; 332 d |= d >> 4; 333 d |= d >> 8; 334 d |= d >> 16; 335 ++d; 336 if (d != dict_size || dict_size == 0) 337 return 0; 338 } 339 340 /* Another hack to ditch false positives: Assume that if the 341 * uncompressed size is known, it must be less than 256 GiB. 342 * Again, if someone complains, this will be reconsidered. 343 */ 344 uncompressed_size = 0; 345 for (i = 0; i < 8; ++i) 346 uncompressed_size |= (uint64_t) (state->in[5 + i]) << (i * 8); 347 348 if (uncompressed_size != UINT64_MAX 349 && uncompressed_size > (UINT64_C(1) << 38)) 350 return 0; 351 352 return 1; 353 } 354 355 #ifdef HAVE_ZLIB_H 356 357 /* Get next byte from input, or -1 if end or error. */ 358 #define NEXT() ((strm->avail_in == 0 && xz_avail(state) == -1) ? -1 : \ 359 (strm->avail_in == 0 ? -1 : \ 360 (strm->avail_in--, *(strm->next_in)++))) 361 /* Same thing, but from zstrm */ 362 #define NEXTZ() ((strm->avail_in == 0 && xz_avail_zstrm(state) == -1) ? -1 : \ 363 (strm->avail_in == 0 ? -1 : \ 364 (strm->avail_in--, *(strm->next_in)++))) 365 366 /* Get a four-byte little-endian integer and return 0 on success and the value 367 in *ret. Otherwise -1 is returned and *ret is not modified. */ 368 static int 369 gz_next4(xz_statep state, unsigned long *ret) 370 { 371 int ch; 372 unsigned long val; 373 z_streamp strm = &(state->zstrm); 374 375 val = NEXTZ(); 376 val += (unsigned) NEXTZ() << 8; 377 val += (unsigned long) NEXTZ() << 16; 378 ch = NEXTZ(); 379 if (ch == -1) 380 return -1; 381 val += (unsigned long) ch << 24; 382 *ret = val; 383 return 0; 384 } 385 #endif 386 387 static int 388 xz_head(xz_statep state) 389 { 390 lzma_stream *strm = &(state->strm); 391 lzma_stream init = LZMA_STREAM_INIT; 392 int flags; 393 unsigned len; 394 395 /* allocate read buffers and inflate memory */ 396 if (state->size == 0) { 397 /* allocate buffers */ 398 state->in = xmlMalloc(state->want); 399 state->out = xmlMalloc(state->want << 1); 400 if (state->in == NULL || state->out == NULL) { 401 if (state->out != NULL) 402 xmlFree(state->out); 403 if (state->in != NULL) 404 xmlFree(state->in); 405 xz_error(state, LZMA_MEM_ERROR, "out of memory"); 406 return -1; 407 } 408 state->size = state->want; 409 410 /* allocate decoder memory */ 411 state->strm = init; 412 state->strm.avail_in = 0; 413 state->strm.next_in = NULL; 414 if (lzma_auto_decoder(&state->strm, UINT64_MAX, 0) != LZMA_OK) { 415 xmlFree(state->out); 416 xmlFree(state->in); 417 state->size = 0; 418 xz_error(state, LZMA_MEM_ERROR, "out of memory"); 419 return -1; 420 } 421 #ifdef HAVE_ZLIB_H 422 /* allocate inflate memory */ 423 state->zstrm.zalloc = Z_NULL; 424 state->zstrm.zfree = Z_NULL; 425 state->zstrm.opaque = Z_NULL; 426 state->zstrm.avail_in = 0; 427 state->zstrm.next_in = Z_NULL; 428 if (state->init == 0) { 429 if (inflateInit2(&(state->zstrm), -15) != Z_OK) {/* raw inflate */ 430 xmlFree(state->out); 431 xmlFree(state->in); 432 state->size = 0; 433 xz_error(state, LZMA_MEM_ERROR, "out of memory"); 434 return -1; 435 } 436 state->init = 1; 437 } 438 #endif 439 } 440 441 /* get some data in the input buffer */ 442 if (strm->avail_in == 0) { 443 if (xz_avail(state) == -1) 444 return -1; 445 if (strm->avail_in == 0) 446 return 0; 447 } 448 449 /* look for the xz magic header bytes */ 450 if (is_format_xz(state) || is_format_lzma(state)) { 451 state->how = LZMA; 452 state->direct = 0; 453 return 0; 454 } 455 #ifdef HAVE_ZLIB_H 456 /* look for the gzip magic header bytes 31 and 139 */ 457 if (strm->next_in[0] == 31) { 458 strm->avail_in--; 459 strm->next_in++; 460 if (strm->avail_in == 0 && xz_avail(state) == -1) 461 return -1; 462 if (strm->avail_in && strm->next_in[0] == 139) { 463 /* we have a gzip header, woo hoo! */ 464 strm->avail_in--; 465 strm->next_in++; 466 467 /* skip rest of header */ 468 if (NEXT() != 8) { /* compression method */ 469 xz_error(state, LZMA_DATA_ERROR, 470 "unknown compression method"); 471 return -1; 472 } 473 flags = NEXT(); 474 if (flags & 0xe0) { /* reserved flag bits */ 475 xz_error(state, LZMA_DATA_ERROR, 476 "unknown header flags set"); 477 return -1; 478 } 479 NEXT(); /* modification time */ 480 NEXT(); 481 NEXT(); 482 NEXT(); 483 NEXT(); /* extra flags */ 484 NEXT(); /* operating system */ 485 if (flags & 4) { /* extra field */ 486 len = (unsigned) NEXT(); 487 len += (unsigned) NEXT() << 8; 488 while (len--) 489 if (NEXT() < 0) 490 break; 491 } 492 if (flags & 8) /* file name */ 493 while (NEXT() > 0) ; 494 if (flags & 16) /* comment */ 495 while (NEXT() > 0) ; 496 if (flags & 2) { /* header crc */ 497 NEXT(); 498 NEXT(); 499 } 500 /* an unexpected end of file is not checked for here -- it will be 501 * noticed on the first request for uncompressed data */ 502 503 /* set up for decompression */ 504 inflateReset(&state->zstrm); 505 state->zstrm.adler = crc32(0L, Z_NULL, 0); 506 state->how = GZIP; 507 state->direct = 0; 508 return 0; 509 } else { 510 /* not a gzip file -- save first byte (31) and fall to raw i/o */ 511 state->out[0] = 31; 512 state->have = 1; 513 } 514 } 515 #endif 516 517 /* doing raw i/o, save start of raw data for seeking, copy any leftover 518 * input to output -- this assumes that the output buffer is larger than 519 * the input buffer, which also assures space for gzungetc() */ 520 state->raw = state->pos; 521 state->next = state->out; 522 if (strm->avail_in) { 523 memcpy(state->next + state->have, strm->next_in, strm->avail_in); 524 state->have += strm->avail_in; 525 strm->avail_in = 0; 526 } 527 state->how = COPY; 528 state->direct = 1; 529 return 0; 530 } 531 532 static int 533 xz_decomp(xz_statep state) 534 { 535 int ret; 536 unsigned had; 537 unsigned long crc, len; 538 lzma_stream *strm = &(state->strm); 539 540 lzma_action action = LZMA_RUN; 541 542 /* fill output buffer up to end of deflate stream */ 543 had = strm->avail_out; 544 do { 545 /* get more input for inflate() */ 546 if (strm->avail_in == 0 && xz_avail(state) == -1) 547 return -1; 548 if (strm->avail_in == 0) { 549 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file"); 550 return -1; 551 } 552 if (state->eof) 553 action = LZMA_FINISH; 554 555 /* decompress and handle errors */ 556 #ifdef HAVE_ZLIB_H 557 if (state->how == GZIP) { 558 state->zstrm.avail_in = (uInt) state->strm.avail_in; 559 state->zstrm.next_in = (Bytef *) state->strm.next_in; 560 state->zstrm.avail_out = (uInt) state->strm.avail_out; 561 state->zstrm.next_out = (Bytef *) state->strm.next_out; 562 ret = inflate(&state->zstrm, Z_NO_FLUSH); 563 if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) { 564 xz_error(state, Z_STREAM_ERROR, 565 "internal error: inflate stream corrupt"); 566 return -1; 567 } 568 if (ret == Z_MEM_ERROR) 569 ret = LZMA_MEM_ERROR; 570 if (ret == Z_DATA_ERROR) 571 ret = LZMA_DATA_ERROR; 572 if (ret == Z_STREAM_END) 573 ret = LZMA_STREAM_END; 574 state->strm.avail_in = state->zstrm.avail_in; 575 state->strm.next_in = state->zstrm.next_in; 576 state->strm.avail_out = state->zstrm.avail_out; 577 state->strm.next_out = state->zstrm.next_out; 578 } else /* state->how == LZMA */ 579 #endif 580 ret = lzma_code(strm, action); 581 if (ret == LZMA_MEM_ERROR) { 582 xz_error(state, LZMA_MEM_ERROR, "out of memory"); 583 return -1; 584 } 585 if (ret == LZMA_DATA_ERROR) { 586 xz_error(state, LZMA_DATA_ERROR, "compressed data error"); 587 return -1; 588 } 589 if (ret == LZMA_PROG_ERROR) { 590 xz_error(state, LZMA_PROG_ERROR, "compression error"); 591 return -1; 592 } 593 } while (strm->avail_out && ret != LZMA_STREAM_END); 594 595 /* update available output and crc check value */ 596 state->have = had - strm->avail_out; 597 state->next = strm->next_out - state->have; 598 #ifdef HAVE_ZLIB_H 599 state->zstrm.adler = 600 crc32(state->zstrm.adler, state->next, state->have); 601 #endif 602 603 if (ret == LZMA_STREAM_END) { 604 #ifdef HAVE_ZLIB_H 605 if (state->how == GZIP) { 606 if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) { 607 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file"); 608 return -1; 609 } 610 if (crc != state->zstrm.adler) { 611 xz_error(state, LZMA_DATA_ERROR, "incorrect data check"); 612 return -1; 613 } 614 if (len != (state->zstrm.total_out & 0xffffffffL)) { 615 xz_error(state, LZMA_DATA_ERROR, "incorrect length check"); 616 return -1; 617 } 618 state->strm.avail_in = 0; 619 state->strm.next_in = NULL; 620 state->strm.avail_out = 0; 621 state->strm.next_out = NULL; 622 } else 623 #endif 624 if (strm->avail_in != 0 || !state->eof) { 625 xz_error(state, LZMA_DATA_ERROR, "trailing garbage"); 626 return -1; 627 } 628 state->how = LOOK; /* ready for next stream, once have is 0 (leave 629 * state->direct unchanged to remember how) */ 630 } 631 632 /* good decompression */ 633 return 0; 634 } 635 636 static int 637 xz_make(xz_statep state) 638 { 639 lzma_stream *strm = &(state->strm); 640 641 if (state->how == LOOK) { /* look for lzma / gzip header */ 642 if (xz_head(state) == -1) 643 return -1; 644 if (state->have) /* got some data from xz_head() */ 645 return 0; 646 } 647 if (state->how == COPY) { /* straight copy */ 648 if (xz_load(state, state->out, state->size << 1, &(state->have)) == 649 -1) 650 return -1; 651 state->next = state->out; 652 } else if (state->how == LZMA || state->how == GZIP) { /* decompress */ 653 strm->avail_out = state->size << 1; 654 strm->next_out = state->out; 655 if (xz_decomp(state) == -1) 656 return -1; 657 } 658 return 0; 659 } 660 661 static int 662 xz_skip(xz_statep state, uint64_t len) 663 { 664 unsigned n; 665 666 /* skip over len bytes or reach end-of-file, whichever comes first */ 667 while (len) 668 /* skip over whatever is in output buffer */ 669 if (state->have) { 670 n = (uint64_t) state->have > len ? 671 (unsigned) len : state->have; 672 state->have -= n; 673 state->next += n; 674 state->pos += n; 675 len -= n; 676 } 677 678 /* output buffer empty -- return if we're at the end of the input */ 679 else if (state->eof && state->strm.avail_in == 0) 680 break; 681 682 /* need more data to skip -- load up output buffer */ 683 else { 684 /* get more output, looking for header if required */ 685 if (xz_make(state) == -1) 686 return -1; 687 } 688 return 0; 689 } 690 691 int 692 __libxml2_xzread(xzFile file, void *buf, unsigned len) 693 { 694 unsigned got, n; 695 xz_statep state; 696 lzma_stream *strm; 697 698 /* get internal structure */ 699 if (file == NULL) 700 return -1; 701 state = (xz_statep) file; 702 strm = &(state->strm); 703 704 /* check that we're reading and that there's no error */ 705 if (state->err != LZMA_OK) 706 return -1; 707 708 /* since an int is returned, make sure len fits in one, otherwise return 709 * with an error (this avoids the flaw in the interface) */ 710 if ((int) len < 0) { 711 xz_error(state, LZMA_BUF_ERROR, 712 "requested length does not fit in int"); 713 return -1; 714 } 715 716 /* if len is zero, avoid unnecessary operations */ 717 if (len == 0) 718 return 0; 719 720 /* process a skip request */ 721 if (state->seek) { 722 state->seek = 0; 723 if (xz_skip(state, state->skip) == -1) 724 return -1; 725 } 726 727 /* get len bytes to buf, or less than len if at the end */ 728 got = 0; 729 do { 730 /* first just try copying data from the output buffer */ 731 if (state->have) { 732 n = state->have > len ? len : state->have; 733 memcpy(buf, state->next, n); 734 state->next += n; 735 state->have -= n; 736 } 737 738 /* output buffer empty -- return if we're at the end of the input */ 739 else if (state->eof && strm->avail_in == 0) 740 break; 741 742 /* need output data -- for small len or new stream load up our output 743 * buffer */ 744 else if (state->how == LOOK || len < (state->size << 1)) { 745 /* get more output, looking for header if required */ 746 if (xz_make(state) == -1) 747 return -1; 748 continue; /* no progress yet -- go back to memcpy() above */ 749 /* the copy above assures that we will leave with space in the 750 * output buffer, allowing at least one gzungetc() to succeed */ 751 } 752 753 /* large len -- read directly into user buffer */ 754 else if (state->how == COPY) { /* read directly */ 755 if (xz_load(state, buf, len, &n) == -1) 756 return -1; 757 } 758 759 /* large len -- decompress directly into user buffer */ 760 else { /* state->how == LZMA */ 761 strm->avail_out = len; 762 strm->next_out = buf; 763 if (xz_decomp(state) == -1) 764 return -1; 765 n = state->have; 766 state->have = 0; 767 } 768 769 /* update progress */ 770 len -= n; 771 buf = (char *) buf + n; 772 got += n; 773 state->pos += n; 774 } while (len); 775 776 /* return number of bytes read into user buffer (will fit in int) */ 777 return (int) got; 778 } 779 780 int 781 __libxml2_xzclose(xzFile file) 782 { 783 int ret; 784 xz_statep state; 785 786 /* get internal structure */ 787 if (file == NULL) 788 return LZMA_DATA_ERROR; 789 state = (xz_statep) file; 790 791 /* free memory and close file */ 792 if (state->size) { 793 lzma_end(&(state->strm)); 794 #ifdef HAVE_ZLIB_H 795 if (state->init == 1) 796 inflateEnd(&(state->zstrm)); 797 state->init = 0; 798 #endif 799 xmlFree(state->out); 800 xmlFree(state->in); 801 } 802 xmlFree(state->path); 803 ret = close(state->fd); 804 xmlFree(state); 805 return ret ? ret : LZMA_OK; 806 } 807 #endif /* LIBXML_LZMA_ENABLED */