1 /**
2 * xzlib.c: front end for the transparent support 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 #include <stdlib.h>
15 #include <errno.h>
16
17 #ifdef HAVE_SYS_STAT_H
18 #include <sys/stat.h>
19 #endif
20 #ifdef HAVE_FCNTL_H
21 #include <fcntl.h>
22 #endif
23 #ifdef HAVE_UNISTD_H
24 #include <unistd.h>
25 #elif defined (_WIN32)
26 #include <io.h>
27 #endif
28 #ifdef LIBXML_ZLIB_ENABLED
29 #include <zlib.h>
30 #endif
31 #ifdef LIBXML_LZMA_ENABLED
32 #include <lzma.h>
33 #endif
34
35 #include "private/xzlib.h"
36 #include <libxml/xmlmemory.h>
37
38 /* values for xz_state how */
39 #define LOOK 0 /* look for a gzip/lzma header */
40 #define COPY 1 /* copy input directly */
41 #define GZIP 2 /* decompress a gzip stream */
42 #define LZMA 3 /* decompress a lzma stream */
43
44 /* internal lzma file state data structure */
45 typedef struct {
46 int mode; /* see lzma modes above */
47 int fd; /* file descriptor */
48 char *path; /* path or fd for error messages */
49 uint64_t pos; /* current position in uncompressed data */
50 unsigned int size; /* buffer size, zero if not allocated yet */
51 unsigned int want; /* requested buffer size, default is BUFSIZ */
52 unsigned char *in; /* input buffer */
53 unsigned char *out; /* output buffer (double-sized when reading) */
54 unsigned char *next; /* next output data to deliver or write */
55 unsigned int have; /* amount of output data unused at next */
56 int eof; /* true if end of input file reached */
57 uint64_t start; /* where the lzma data started, for rewinding */
58 uint64_t raw; /* where the raw data started, for seeking */
59 int how; /* 0: get header, 1: copy, 2: decompress */
60 int direct; /* true if last read direct, false if lzma */
61 /* seek request */
62 uint64_t skip; /* amount to skip (already rewound if backwards) */
63 int seek; /* true if seek request pending */
64 /* error information */
65 int err; /* error code */
66 char *msg; /* error message */
67 /* lzma stream */
68 int init; /* is the inflate stream initialized */
69 lzma_stream strm; /* stream structure in-place (not a pointer) */
70 char padding1[32]; /* padding allowing to cope with possible
71 extensions of above structure without
72 too much side effect */
73 #ifdef LIBXML_ZLIB_ENABLED
74 /* zlib inflate or deflate stream */
75 z_stream zstrm; /* stream structure in-place (not a pointer) */
76 #endif
77 char padding2[32]; /* padding allowing to cope with possible
78 extensions of above structure without
79 too much side effect */
80 } xz_state, *xz_statep;
81
82 static void
83 xz_error(xz_statep state, int err, const char *msg)
84 {
85 /* free previously allocated message and clear */
86 if (state->msg != NULL) {
87 if (state->err != LZMA_MEM_ERROR)
88 xmlFree(state->msg);
89 state->msg = NULL;
90 }
91
92 /* set error code, and if no message, then done */
93 state->err = err;
94 if (msg == NULL)
95 return;
96
97 /* for an out of memory error, save as static string */
98 if (err == LZMA_MEM_ERROR) {
99 state->msg = (char *) msg;
100 return;
101 }
102
103 /* construct error message with path */
104 if ((state->msg =
105 xmlMalloc(strlen(state->path) + strlen(msg) + 3)) == NULL) {
106 state->err = LZMA_MEM_ERROR;
107 state->msg = (char *) "out of memory";
108 return;
109 }
110 strcpy(state->msg, state->path);
111 strcat(state->msg, ": ");
112 strcat(state->msg, msg);
113 return;
114 }
115
116 static void
117 xz_reset(xz_statep state)
118 {
119 state->have = 0; /* no output data available */
120 state->eof = 0; /* not at end of file */
121 state->how = LOOK; /* look for gzip header */
122 state->direct = 1; /* default for empty file */
123 state->seek = 0; /* no seek request pending */
124 xz_error(state, LZMA_OK, NULL); /* clear error */
125 state->pos = 0; /* no uncompressed data yet */
126 state->strm.avail_in = 0; /* no input data yet */
127 #ifdef LIBXML_ZLIB_ENABLED
128 state->zstrm.avail_in = 0; /* no input data yet */
129 #endif
130 }
131
132 static xzFile
133 xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED)
134 {
135 xz_statep state;
136 off_t offset;
137
138 /* allocate xzFile structure to return */
139 state = xmlMalloc(sizeof(xz_state));
140 if (state == NULL)
141 return NULL;
142 state->size = 0; /* no buffers allocated yet */
143 state->want = BUFSIZ; /* requested buffer size */
144 state->msg = NULL; /* no error message yet */
145 state->init = 0; /* initialization of zlib data */
146
147 /* save the path name for error messages */
148 state->path = xmlMalloc(strlen(path) + 1);
149 if (state->path == NULL) {
150 xmlFree(state);
151 return NULL;
152 }
153 strcpy(state->path, path);
154
155 /* open the file with the appropriate mode (or just use fd) */
156 state->fd = fd != -1 ? fd : open(path,
157 #ifdef O_LARGEFILE
158 O_LARGEFILE |
159 #endif
160 #ifdef O_BINARY
161 O_BINARY |
162 #endif
163 O_RDONLY, 0666);
164 if (state->fd == -1) {
165 xmlFree(state->path);
166 xmlFree(state);
167 return NULL;
168 }
169
170 /* save the current position for rewinding (only if reading) */
171 offset = lseek(state->fd, 0, SEEK_CUR);
172 if (offset == -1)
173 state->start = 0;
174 else
175 state->start = offset;
176
177 /* initialize stream */
178 xz_reset(state);
179
180 /* return stream */
181 return (xzFile) state;
182 }
183
184 static int
185 xz_compressed(xzFile f) {
186 xz_statep state;
187
188 if (f == NULL)
189 return(-1);
190 state = (xz_statep) f;
191 if (state->init <= 0)
192 return(-1);
193
194 switch (state->how) {
195 case COPY:
196 return(0);
197 case GZIP:
198 case LZMA:
199 return(1);
200 }
201 return(-1);
202 }
203
204 xzFile
205 __libxml2_xzopen(const char *path, const char *mode)
206 {
207 return xz_open(path, -1, mode);
208 }
209
210 int
211 __libxml2_xzcompressed(xzFile f) {
212 return xz_compressed(f);
213 }
214
215 xzFile
216 __libxml2_xzdopen(int fd, const char *mode)
217 {
218 char *path; /* identifier for error messages */
219 size_t path_size = 7 + 3 * sizeof(int);
220 xzFile xz;
221
222 if (fd == -1 || (path = xmlMalloc(path_size)) == NULL)
223 return NULL;
224 snprintf(path, path_size, "<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 LIBXML_ZLIB_ENABLED
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 LIBXML_ZLIB_ENABLED
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 /* Avoid unused variable warning if features are disabled. */
391 (void) flags;
392 (void) len;
393
394 /* allocate read buffers and inflate memory */
395 if (state->size == 0) {
396 /* allocate buffers */
397 state->in = xmlMalloc(state->want);
398 state->out = xmlMalloc(state->want << 1);
399 if (state->in == NULL || state->out == NULL) {
400 if (state->out != NULL)
401 xmlFree(state->out);
402 if (state->in != NULL)
403 xmlFree(state->in);
404 xz_error(state, LZMA_MEM_ERROR, "out of memory");
405 return -1;
406 }
407 state->size = state->want;
408
409 /* allocate decoder memory */
410 state->strm = init;
411 state->strm.avail_in = 0;
412 state->strm.next_in = NULL;
413 if (lzma_auto_decoder(&state->strm, 100000000, 0) != LZMA_OK) {
414 xmlFree(state->out);
415 xmlFree(state->in);
416 state->size = 0;
417 xz_error(state, LZMA_MEM_ERROR, "out of memory");
418 return -1;
419 }
420 #ifdef LIBXML_ZLIB_ENABLED
421 /* allocate inflate memory */
422 state->zstrm.zalloc = Z_NULL;
423 state->zstrm.zfree = Z_NULL;
424 state->zstrm.opaque = Z_NULL;
425 state->zstrm.avail_in = 0;
426 state->zstrm.next_in = Z_NULL;
427 if (state->init == 0) {
428 if (inflateInit2(&(state->zstrm), -15) != Z_OK) {/* raw inflate */
429 xmlFree(state->out);
430 xmlFree(state->in);
431 state->size = 0;
432 xz_error(state, LZMA_MEM_ERROR, "out of memory");
433 return -1;
434 }
435 state->init = 1;
436 }
437 #endif
438 }
439
440 /* get some data in the input buffer */
441 if (strm->avail_in == 0) {
442 if (xz_avail(state) == -1)
443 return -1;
444 if (strm->avail_in == 0)
445 return 0;
446 }
447
448 /* look for the xz magic header bytes */
449 if (is_format_xz(state) || is_format_lzma(state)) {
450 state->how = LZMA;
451 state->direct = 0;
452 return 0;
453 }
454 #ifdef LIBXML_ZLIB_ENABLED
455 /* look for the gzip magic header bytes 31 and 139 */
456 if (strm->next_in[0] == 31) {
457 strm->avail_in--;
458 strm->next_in++;
459 if (strm->avail_in == 0 && xz_avail(state) == -1)
460 return -1;
461 if (strm->avail_in && strm->next_in[0] == 139) {
462 /* we have a gzip header, woo hoo! */
463 strm->avail_in--;
464 strm->next_in++;
465
466 /* skip rest of header */
467 if (NEXT() != 8) { /* compression method */
468 xz_error(state, LZMA_DATA_ERROR,
469 "unknown compression method");
470 return -1;
471 }
472 flags = NEXT();
473 if (flags & 0xe0) { /* reserved flag bits */
474 xz_error(state, LZMA_DATA_ERROR,
475 "unknown header flags set");
476 return -1;
477 }
478 NEXT(); /* modification time */
479 NEXT();
480 NEXT();
481 NEXT();
482 NEXT(); /* extra flags */
483 NEXT(); /* operating system */
484 if (flags & 4) { /* extra field */
485 len = (unsigned) NEXT();
486 len += (unsigned) NEXT() << 8;
487 while (len--)
488 if (NEXT() < 0)
489 break;
490 }
491 if (flags & 8) /* file name */
492 while (NEXT() > 0) ;
493 if (flags & 16) /* comment */
494 while (NEXT() > 0) ;
495 if (flags & 2) { /* header crc */
496 NEXT();
497 NEXT();
498 }
499 /* an unexpected end of file is not checked for here -- it will be
500 * noticed on the first request for uncompressed data */
501
502 /* set up for decompression */
503 inflateReset(&state->zstrm);
504 state->zstrm.adler = crc32(0L, Z_NULL, 0);
505 state->how = GZIP;
506 state->direct = 0;
507 return 0;
508 } else {
509 /* not a gzip file -- save first byte (31) and fall to raw i/o */
510 state->out[0] = 31;
511 state->have = 1;
512 }
513 }
514 #endif
515
516 /* doing raw i/o, save start of raw data for seeking, copy any leftover
517 * input to output -- this assumes that the output buffer is larger than
518 * the input buffer, which also assures space for gzungetc() */
519 state->raw = state->pos;
520 state->next = state->out;
521 if (strm->avail_in) {
522 memcpy(state->next + state->have, strm->next_in, strm->avail_in);
523 state->have += strm->avail_in;
524 strm->avail_in = 0;
525 }
526 state->how = COPY;
527 state->direct = 1;
528 return 0;
529 }
530
531 static int
532 xz_decomp(xz_statep state)
533 {
534 int ret;
535 unsigned had;
536 unsigned long crc, len;
537 lzma_stream *strm = &(state->strm);
538
539 lzma_action action = LZMA_RUN;
540
541 /* Avoid unused variable warning if features are disabled. */
542 (void) crc;
543 (void) len;
544
545 /* fill output buffer up to end of deflate stream */
546 had = strm->avail_out;
547 do {
548 /* get more input for inflate() */
549 if (strm->avail_in == 0 && xz_avail(state) == -1)
550 return -1;
551 if (strm->avail_in == 0) {
552 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
553 return -1;
554 }
555 if (state->eof)
556 action = LZMA_FINISH;
557
558 /* decompress and handle errors */
559 #ifdef LIBXML_ZLIB_ENABLED
560 if (state->how == GZIP) {
561 state->zstrm.avail_in = (uInt) state->strm.avail_in;
562 state->zstrm.next_in = (Bytef *) state->strm.next_in;
563 state->zstrm.avail_out = (uInt) state->strm.avail_out;
564 state->zstrm.next_out = (Bytef *) state->strm.next_out;
565 ret = inflate(&state->zstrm, Z_NO_FLUSH);
566 if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
567 xz_error(state, Z_STREAM_ERROR,
568 "internal error: inflate stream corrupt");
569 return -1;
570 }
571 /*
572 * FIXME: Remapping a couple of error codes and falling through
573 * to the LZMA error handling looks fragile.
574 */
575 if (ret == Z_MEM_ERROR)
576 ret = LZMA_MEM_ERROR;
577 if (ret == Z_DATA_ERROR)
578 ret = LZMA_DATA_ERROR;
579 if (ret == Z_STREAM_END)
580 ret = LZMA_STREAM_END;
581 state->strm.avail_in = state->zstrm.avail_in;
582 state->strm.next_in = state->zstrm.next_in;
583 state->strm.avail_out = state->zstrm.avail_out;
584 state->strm.next_out = state->zstrm.next_out;
585 } else /* state->how == LZMA */
586 #endif
587 ret = lzma_code(strm, action);
588 if (ret == LZMA_MEM_ERROR) {
589 xz_error(state, LZMA_MEM_ERROR, "out of memory");
590 return -1;
591 }
592 if (ret == LZMA_DATA_ERROR) {
593 xz_error(state, LZMA_DATA_ERROR, "compressed data error");
594 return -1;
595 }
596 if (ret == LZMA_PROG_ERROR) {
597 xz_error(state, LZMA_PROG_ERROR, "compression error");
598 return -1;
599 }
600 if ((state->how != GZIP) &&
601 (ret != LZMA_OK) && (ret != LZMA_STREAM_END)) {
602 xz_error(state, ret, "lzma error");
603 return -1;
604 }
605 } while (strm->avail_out && ret != LZMA_STREAM_END);
606
607 /* update available output and crc check value */
608 state->have = had - strm->avail_out;
609 state->next = strm->next_out - state->have;
610 #ifdef LIBXML_ZLIB_ENABLED
611 state->zstrm.adler =
612 crc32(state->zstrm.adler, state->next, state->have);
613 #endif
614
615 if (ret == LZMA_STREAM_END) {
616 #ifdef LIBXML_ZLIB_ENABLED
617 if (state->how == GZIP) {
618 if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
619 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
620 return -1;
621 }
622 if (crc != state->zstrm.adler) {
623 xz_error(state, LZMA_DATA_ERROR, "incorrect data check");
624 return -1;
625 }
626 if (len != (state->zstrm.total_out & 0xffffffffL)) {
627 xz_error(state, LZMA_DATA_ERROR, "incorrect length check");
628 return -1;
629 }
630 state->strm.avail_in = 0;
631 state->strm.next_in = NULL;
632 state->strm.avail_out = 0;
633 state->strm.next_out = NULL;
634 } else
635 #endif
636 if (strm->avail_in != 0 || !state->eof) {
637 xz_error(state, LZMA_DATA_ERROR, "trailing garbage");
638 return -1;
639 }
640 state->how = LOOK; /* ready for next stream, once have is 0 (leave
641 * state->direct unchanged to remember how) */
642 }
643
644 /* good decompression */
645 return 0;
646 }
647
648 static int
649 xz_make(xz_statep state)
650 {
651 lzma_stream *strm = &(state->strm);
652
653 if (state->how == LOOK) { /* look for lzma / gzip header */
654 if (xz_head(state) == -1)
655 return -1;
656 if (state->have) /* got some data from xz_head() */
657 return 0;
658 }
659 if (state->how == COPY) { /* straight copy */
660 if (xz_load(state, state->out, state->size << 1, &(state->have)) ==
661 -1)
662 return -1;
663 state->next = state->out;
664 } else if (state->how == LZMA || state->how == GZIP) { /* decompress */
665 strm->avail_out = state->size << 1;
666 strm->next_out = state->out;
667 if (xz_decomp(state) == -1)
668 return -1;
669 }
670 return 0;
671 }
672
673 static int
674 xz_skip(xz_statep state, uint64_t len)
675 {
676 unsigned n;
677
678 /* skip over len bytes or reach end-of-file, whichever comes first */
679 while (len)
680 /* skip over whatever is in output buffer */
681 if (state->have) {
682 n = (uint64_t) state->have > len ?
683 (unsigned) len : state->have;
684 state->have -= n;
685 state->next += n;
686 state->pos += n;
687 len -= n;
688 }
689
690 /* output buffer empty -- return if we're at the end of the input */
691 else if (state->eof && state->strm.avail_in == 0)
692 break;
693
694 /* need more data to skip -- load up output buffer */
695 else {
696 /* get more output, looking for header if required */
697 if (xz_make(state) == -1)
698 return -1;
699 }
700 return 0;
701 }
702
703 int
704 __libxml2_xzread(xzFile file, void *buf, unsigned len)
705 {
706 unsigned got, n;
707 xz_statep state;
708 lzma_stream *strm;
709
710 /* get internal structure */
711 if (file == NULL)
712 return -1;
713 state = (xz_statep) file;
714 strm = &(state->strm);
715
716 /* check that we're reading and that there's no error */
717 if (state->err != LZMA_OK)
718 return -1;
719
720 /* since an int is returned, make sure len fits in one, otherwise return
721 * with an error (this avoids the flaw in the interface) */
722 if ((int) len < 0) {
723 xz_error(state, LZMA_BUF_ERROR,
724 "requested length does not fit in int");
725 return -1;
726 }
727
728 /* if len is zero, avoid unnecessary operations */
729 if (len == 0)
730 return 0;
731
732 /* process a skip request */
733 if (state->seek) {
734 state->seek = 0;
735 if (xz_skip(state, state->skip) == -1)
736 return -1;
737 }
738
739 /* get len bytes to buf, or less than len if at the end */
740 got = 0;
741 do {
742 /* first just try copying data from the output buffer */
743 if (state->have) {
744 n = state->have > len ? len : state->have;
745 memcpy(buf, state->next, n);
746 state->next += n;
747 state->have -= n;
748 }
749
750 /* output buffer empty -- return if we're at the end of the input */
751 else if (state->eof && strm->avail_in == 0)
752 break;
753
754 /* need output data -- for small len or new stream load up our output
755 * buffer */
756 else if (state->how == LOOK || len < (state->size << 1)) {
757 /* get more output, looking for header if required */
758 if (xz_make(state) == -1)
759 return -1;
760 continue; /* no progress yet -- go back to memcpy() above */
761 /* the copy above assures that we will leave with space in the
762 * output buffer, allowing at least one gzungetc() to succeed */
763 }
764
765 /* large len -- read directly into user buffer */
766 else if (state->how == COPY) { /* read directly */
767 if (xz_load(state, buf, len, &n) == -1)
768 return -1;
769 }
770
771 /* large len -- decompress directly into user buffer */
772 else { /* state->how == LZMA */
773 strm->avail_out = len;
774 strm->next_out = buf;
775 if (xz_decomp(state) == -1)
776 return -1;
777 n = state->have;
778 state->have = 0;
779 }
780
781 /* update progress */
782 len -= n;
783 buf = (char *) buf + n;
784 got += n;
785 state->pos += n;
786 } while (len);
787
788 /* return number of bytes read into user buffer (will fit in int) */
789 return (int) got;
790 }
791
792 int
793 __libxml2_xzclose(xzFile file)
794 {
795 int ret;
796 xz_statep state;
797
798 /* get internal structure */
799 if (file == NULL)
800 return LZMA_DATA_ERROR;
801 state = (xz_statep) file;
802
803 /* free memory and close file */
804 if (state->size) {
805 lzma_end(&(state->strm));
806 #ifdef LIBXML_ZLIB_ENABLED
807 if (state->init == 1)
808 inflateEnd(&(state->zstrm));
809 state->init = 0;
810 #endif
811 xmlFree(state->out);
812 xmlFree(state->in);
813 }
814 xmlFree(state->path);
815 if ((state->msg != NULL) && (state->err != LZMA_MEM_ERROR))
816 xmlFree(state->msg);
817 ret = close(state->fd);
818 xmlFree(state);
819 return ret ? ret : LZMA_OK;
820 }
821 #endif /* LIBXML_LZMA_ENABLED */