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 <[email protected]>
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 #include <fcntl.h>
18 #include <sys/stat.h>
19
20 #ifdef _WIN32
21 #include <io.h>
22 #else
23 #include <unistd.h>
24 #endif
25
26 #ifdef LIBXML_ZLIB_ENABLED
27 #include <zlib.h>
28 #endif
29 #ifdef LIBXML_LZMA_ENABLED
30 #include <lzma.h>
31 #endif
32
33 #include "private/xzlib.h"
34 #include <libxml/xmlmemory.h>
35
36 /* values for xz_state how */
37 #define LOOK 0 /* look for a gzip/lzma header */
38 #define COPY 1 /* copy input directly */
39 #define GZIP 2 /* decompress a gzip stream */
40 #define LZMA 3 /* decompress a lzma stream */
41
42 /* internal lzma file state data structure */
43 typedef struct {
44 int mode; /* see lzma modes above */
45 int fd; /* file descriptor */
46 char *path; /* path or fd for error messages */
47 uint64_t pos; /* current position in uncompressed data */
48 unsigned int size; /* buffer size, zero if not allocated yet */
49 unsigned int want; /* requested buffer size, default is BUFSIZ */
50 unsigned char *in; /* input buffer */
51 unsigned char *out; /* output buffer (double-sized when reading) */
52 unsigned char *next; /* next output data to deliver or write */
53 unsigned int have; /* amount of output data unused at next */
54 int eof; /* true if end of input file reached */
55 uint64_t start; /* where the lzma data started, for rewinding */
56 uint64_t raw; /* where the raw data started, for seeking */
57 int how; /* 0: get header, 1: copy, 2: decompress */
58 int direct; /* true if last read direct, false if lzma */
59 /* seek request */
60 uint64_t skip; /* amount to skip (already rewound if backwards) */
61 int seek; /* true if seek request pending */
62 /* error information */
63 int err; /* error code */
64 char *msg; /* error message */
65 /* lzma stream */
66 int init; /* is the inflate stream initialized */
67 lzma_stream strm; /* stream structure in-place (not a pointer) */
68 char padding1[32]; /* padding allowing to cope with possible
69 extensions of above structure without
70 too much side effect */
71 #ifdef LIBXML_ZLIB_ENABLED
72 /* zlib inflate or deflate stream */
73 z_stream zstrm; /* stream structure in-place (not a pointer) */
74 #endif
75 char padding2[32]; /* padding allowing to cope with possible
76 extensions of above structure without
77 too much side effect */
78 } xz_state, *xz_statep;
79
80 static void
xz_error(xz_statep state,int err,const char * msg)81 xz_error(xz_statep state, int err, const char *msg)
82 {
83 /* free previously allocated message and clear */
84 if (state->msg != NULL) {
85 if (state->err != LZMA_MEM_ERROR)
86 xmlFree(state->msg);
87 state->msg = NULL;
88 }
89
90 /* set error code, and if no message, then done */
91 state->err = err;
92 if (msg == NULL)
93 return;
94
95 /* for an out of memory error, save as static string */
96 if (err == LZMA_MEM_ERROR) {
97 state->msg = (char *) msg;
98 return;
99 }
100
101 /* construct error message with path */
102 state->msg = xmlMalloc(strlen(state->path) + strlen(msg) + 3);
103 if (state->msg == NULL) {
104 state->err = LZMA_MEM_ERROR;
105 state->msg = (char *) "out of memory";
106 return;
107 }
108 strcpy(state->msg, state->path);
109 strcat(state->msg, ": ");
110 strcat(state->msg, msg);
111 }
112
113 static void
xz_reset(xz_statep state)114 xz_reset(xz_statep state)
115 {
116 state->have = 0; /* no output data available */
117 state->eof = 0; /* not at end of file */
118 state->how = LOOK; /* look for gzip header */
119 state->direct = 1; /* default for empty file */
120 state->seek = 0; /* no seek request pending */
121 xz_error(state, LZMA_OK, NULL); /* clear error */
122 state->pos = 0; /* no uncompressed data yet */
123 state->strm.avail_in = 0; /* no input data yet */
124 #ifdef LIBXML_ZLIB_ENABLED
125 state->zstrm.avail_in = 0; /* no input data yet */
126 #endif
127 }
128
129 static xzFile
xz_open(const char * path,int fd,const char * mode ATTRIBUTE_UNUSED)130 xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED)
131 {
132 xz_statep state;
133 off_t offset;
134
135 /* allocate xzFile structure to return */
136 state = xmlMalloc(sizeof(xz_state));
137 if (state == NULL)
138 return NULL;
139 state->size = 0; /* no buffers allocated yet */
140 state->want = BUFSIZ; /* requested buffer size */
141 state->msg = NULL; /* no error message yet */
142 state->init = 0; /* initialization of zlib data */
143
144 /* save the path name for error messages */
145 state->path = xmlMalloc(strlen(path) + 1);
146 if (state->path == NULL) {
147 xmlFree(state);
148 return NULL;
149 }
150 strcpy(state->path, path);
151
152 /* open the file with the appropriate mode (or just use fd) */
153 state->fd = fd != -1 ? fd : open(path,
154 #ifdef O_LARGEFILE
155 O_LARGEFILE |
156 #endif
157 #ifdef O_BINARY
158 O_BINARY |
159 #endif
160 O_RDONLY, 0666);
161 if (state->fd == -1) {
162 xmlFree(state->path);
163 xmlFree(state);
164 return NULL;
165 }
166
167 /* save the current position for rewinding (only if reading) */
168 offset = lseek(state->fd, 0, SEEK_CUR);
169 if (offset == -1)
170 state->start = 0;
171 else
172 state->start = offset;
173
174 /* initialize stream */
175 xz_reset(state);
176
177 /* return stream */
178 return (xzFile) state;
179 }
180
181 static int
xz_compressed(xzFile f)182 xz_compressed(xzFile f) {
183 xz_statep state;
184
185 if (f == NULL)
186 return(-1);
187 state = (xz_statep) f;
188 if (state->init <= 0)
189 return(-1);
190
191 switch (state->how) {
192 case COPY:
193 return(0);
194 case GZIP:
195 #ifdef LIBXML_ZLIB_ENABLED
196 /* Don't use lzma for gzip */
197 return(0);
198 #else
199 return(1);
200 #endif
201 case LZMA:
202 return(1);
203 }
204 return(-1);
205 }
206
207 xzFile
__libxml2_xzopen(const char * path,const char * mode)208 __libxml2_xzopen(const char *path, const char *mode)
209 {
210 return xz_open(path, -1, mode);
211 }
212
213 xzFile
__libxml2_xzdopen(const char * path,int fd,const char * mode)214 __libxml2_xzdopen(const char *path, int fd, const char *mode)
215 {
216 return xz_open(path, fd, mode);
217 }
218
219 static int
xz_load(xz_statep state,unsigned char * buf,unsigned int len,unsigned int * have)220 xz_load(xz_statep state, unsigned char *buf, unsigned int len,
221 unsigned int *have)
222 {
223 int ret;
224
225 *have = 0;
226 do {
227 ret = read(state->fd, buf + *have, len - *have);
228 if (ret <= 0)
229 break;
230 *have += ret;
231 } while (*have < len);
232 if (ret < 0) {
233 xz_error(state, -1, strerror(errno));
234 return -1;
235 }
236 if (ret == 0)
237 state->eof = 1;
238 return 0;
239 }
240
241 static int
xz_avail(xz_statep state)242 xz_avail(xz_statep state)
243 {
244 lzma_stream *strm = &(state->strm);
245
246 if (state->err != LZMA_OK)
247 return -1;
248 if (state->eof == 0) {
249 /* avail_in is size_t, which is not necessary sizeof(unsigned) */
250 unsigned tmp = strm->avail_in;
251
252 if (xz_load(state, state->in, state->size, &tmp) == -1) {
253 strm->avail_in = tmp;
254 return -1;
255 }
256 strm->avail_in = tmp;
257 strm->next_in = state->in;
258 }
259 return 0;
260 }
261
262 #ifdef LIBXML_ZLIB_ENABLED
263 static int
xz_avail_zstrm(xz_statep state)264 xz_avail_zstrm(xz_statep state)
265 {
266 int ret;
267 state->strm.avail_in = state->zstrm.avail_in;
268 state->strm.next_in = state->zstrm.next_in;
269 ret = xz_avail(state);
270 state->zstrm.avail_in = (uInt) state->strm.avail_in;
271 state->zstrm.next_in = (Bytef *) state->strm.next_in;
272 return ret;
273 }
274 #endif
275
276 static int
is_format_xz(xz_statep state)277 is_format_xz(xz_statep state)
278 {
279 lzma_stream *strm = &(state->strm);
280
281 return strm->avail_in >= 6 && memcmp(state->in, "\3757zXZ", 6) == 0;
282 }
283
284 static int
is_format_lzma(xz_statep state)285 is_format_lzma(xz_statep state)
286 {
287 lzma_stream *strm = &(state->strm);
288
289 lzma_filter filter;
290 lzma_options_lzma *opt;
291 uint32_t dict_size;
292 uint64_t uncompressed_size;
293 size_t i;
294
295 if (strm->avail_in < 13)
296 return 0;
297
298 filter.id = LZMA_FILTER_LZMA1;
299 if (lzma_properties_decode(&filter, NULL, state->in, 5) != LZMA_OK)
300 return 0;
301
302 opt = filter.options;
303 dict_size = opt->dict_size;
304 free(opt); /* we can't use xmlFree on a string returned by zlib */
305
306 /* A hack to ditch tons of false positives: We allow only dictionary
307 * sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone
308 * created only files with 2^n, but accepts any dictionary size.
309 * If someone complains, this will be reconsidered.
310 */
311 if (dict_size != UINT32_MAX) {
312 uint32_t d;
313
314 if (dict_size == 0)
315 return 0;
316
317 d = dict_size - 1;
318 d |= d >> 2;
319 d |= d >> 3;
320 d |= d >> 4;
321 d |= d >> 8;
322 d |= d >> 16;
323 ++d;
324 if (d != dict_size || dict_size == 0)
325 return 0;
326 }
327
328 /* Another hack to ditch false positives: Assume that if the
329 * uncompressed size is known, it must be less than 256 GiB.
330 * Again, if someone complains, this will be reconsidered.
331 */
332 uncompressed_size = 0;
333 for (i = 0; i < 8; ++i)
334 uncompressed_size |= (uint64_t) (state->in[5 + i]) << (i * 8);
335
336 if (uncompressed_size != UINT64_MAX
337 && uncompressed_size > (UINT64_C(1) << 38))
338 return 0;
339
340 return 1;
341 }
342
343 #ifdef LIBXML_ZLIB_ENABLED
344
345 /* Get next byte from input, or -1 if end or error. */
346 #define NEXT() ((strm->avail_in == 0 && xz_avail(state) == -1) ? -1 : \
347 (strm->avail_in == 0 ? -1 : \
348 (strm->avail_in--, *(strm->next_in)++)))
349 /* Same thing, but from zstrm */
350 #define NEXTZ() ((strm->avail_in == 0 && xz_avail_zstrm(state) == -1) ? -1 : \
351 (strm->avail_in == 0 ? -1 : \
352 (strm->avail_in--, *(strm->next_in)++)))
353
354 /* Get a four-byte little-endian integer and return 0 on success and the value
355 in *ret. Otherwise -1 is returned and *ret is not modified. */
356 static int
gz_next4(xz_statep state,unsigned long * ret)357 gz_next4(xz_statep state, unsigned long *ret)
358 {
359 int ch;
360 unsigned long val;
361 z_streamp strm = &(state->zstrm);
362
363 val = NEXTZ();
364 val += (unsigned) NEXTZ() << 8;
365 val += (unsigned long) NEXTZ() << 16;
366 ch = NEXTZ();
367 if (ch == -1)
368 return -1;
369 val += (unsigned long) ch << 24;
370 *ret = val;
371 return 0;
372 }
373 #endif
374
375 static int
xz_head(xz_statep state)376 xz_head(xz_statep state)
377 {
378 lzma_stream *strm = &(state->strm);
379 lzma_stream init = LZMA_STREAM_INIT;
380 int flags;
381 unsigned len;
382
383 /* Avoid unused variable warning if features are disabled. */
384 (void) flags;
385 (void) len;
386
387 /* allocate read buffers and inflate memory */
388 if (state->size == 0) {
389 /* allocate buffers */
390 state->in = xmlMalloc(state->want);
391 state->out = xmlMalloc(state->want << 1);
392 if (state->in == NULL || state->out == NULL) {
393 if (state->out != NULL)
394 xmlFree(state->out);
395 if (state->in != NULL)
396 xmlFree(state->in);
397 xz_error(state, LZMA_MEM_ERROR, "out of memory");
398 return -1;
399 }
400 state->size = state->want;
401
402 /* allocate decoder memory */
403 state->strm = init;
404 state->strm.avail_in = 0;
405 state->strm.next_in = NULL;
406 if (lzma_auto_decoder(&state->strm, 100000000, 0) != LZMA_OK) {
407 xmlFree(state->out);
408 xmlFree(state->in);
409 state->size = 0;
410 xz_error(state, LZMA_MEM_ERROR, "out of memory");
411 return -1;
412 }
413 #ifdef LIBXML_ZLIB_ENABLED
414 /* allocate inflate memory */
415 state->zstrm.zalloc = Z_NULL;
416 state->zstrm.zfree = Z_NULL;
417 state->zstrm.opaque = Z_NULL;
418 state->zstrm.avail_in = 0;
419 state->zstrm.next_in = Z_NULL;
420 if (state->init == 0) {
421 if (inflateInit2(&(state->zstrm), -15) != Z_OK) {/* raw inflate */
422 xmlFree(state->out);
423 xmlFree(state->in);
424 state->size = 0;
425 xz_error(state, LZMA_MEM_ERROR, "out of memory");
426 return -1;
427 }
428 state->init = 1;
429 }
430 #endif
431 }
432
433 /* get some data in the input buffer */
434 if (strm->avail_in == 0) {
435 if (xz_avail(state) == -1)
436 return -1;
437 if (strm->avail_in == 0)
438 return 0;
439 }
440
441 /* look for the xz magic header bytes */
442 if (is_format_xz(state) || is_format_lzma(state)) {
443 state->how = LZMA;
444 state->direct = 0;
445 return 0;
446 }
447 #ifdef LIBXML_ZLIB_ENABLED
448 /* look for the gzip magic header bytes 31 and 139 */
449 if (strm->next_in[0] == 31) {
450 strm->avail_in--;
451 strm->next_in++;
452 if (strm->avail_in == 0 && xz_avail(state) == -1)
453 return -1;
454 if (strm->avail_in && strm->next_in[0] == 139) {
455 /* we have a gzip header, woo hoo! */
456 strm->avail_in--;
457 strm->next_in++;
458
459 /* skip rest of header */
460 if (NEXT() != 8) { /* compression method */
461 xz_error(state, LZMA_DATA_ERROR,
462 "unknown compression method");
463 return -1;
464 }
465 flags = NEXT();
466 if (flags & 0xe0) { /* reserved flag bits */
467 xz_error(state, LZMA_DATA_ERROR,
468 "unknown header flags set");
469 return -1;
470 }
471 NEXT(); /* modification time */
472 NEXT();
473 NEXT();
474 NEXT();
475 NEXT(); /* extra flags */
476 NEXT(); /* operating system */
477 if (flags & 4) { /* extra field */
478 len = (unsigned) NEXT();
479 len += (unsigned) NEXT() << 8;
480 while (len--)
481 if (NEXT() < 0)
482 break;
483 }
484 if (flags & 8) /* file name */
485 while (NEXT() > 0) ;
486 if (flags & 16) /* comment */
487 while (NEXT() > 0) ;
488 if (flags & 2) { /* header crc */
489 NEXT();
490 NEXT();
491 }
492 /* an unexpected end of file is not checked for here -- it will be
493 * noticed on the first request for uncompressed data */
494
495 /* set up for decompression */
496 inflateReset(&state->zstrm);
497 state->zstrm.adler = crc32(0L, Z_NULL, 0);
498 state->how = GZIP;
499 state->direct = 0;
500 return 0;
501 } else {
502 /* not a gzip file -- save first byte (31) and fall to raw i/o */
503 state->out[0] = 31;
504 state->have = 1;
505 }
506 }
507 #endif
508
509 /* doing raw i/o, save start of raw data for seeking, copy any leftover
510 * input to output -- this assumes that the output buffer is larger than
511 * the input buffer, which also assures space for gzungetc() */
512 state->raw = state->pos;
513 state->next = state->out;
514 if (strm->avail_in) {
515 memcpy(state->next + state->have, strm->next_in, strm->avail_in);
516 state->have += strm->avail_in;
517 strm->avail_in = 0;
518 }
519 state->how = COPY;
520 state->direct = 1;
521 return 0;
522 }
523
524 static int
xz_decomp(xz_statep state)525 xz_decomp(xz_statep state)
526 {
527 int ret;
528 unsigned had;
529 unsigned long crc, len;
530 lzma_stream *strm = &(state->strm);
531
532 lzma_action action = LZMA_RUN;
533
534 /* Avoid unused variable warning if features are disabled. */
535 (void) crc;
536 (void) len;
537
538 /* fill output buffer up to end of deflate stream */
539 had = strm->avail_out;
540 do {
541 /* get more input for inflate() */
542 if (strm->avail_in == 0 && xz_avail(state) == -1)
543 return -1;
544 if (strm->avail_in == 0) {
545 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
546 return -1;
547 }
548 if (state->eof)
549 action = LZMA_FINISH;
550
551 /* decompress and handle errors */
552 #ifdef LIBXML_ZLIB_ENABLED
553 if (state->how == GZIP) {
554 state->zstrm.avail_in = (uInt) state->strm.avail_in;
555 state->zstrm.next_in = (Bytef *) state->strm.next_in;
556 state->zstrm.avail_out = (uInt) state->strm.avail_out;
557 state->zstrm.next_out = (Bytef *) state->strm.next_out;
558 ret = inflate(&state->zstrm, Z_NO_FLUSH);
559 if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
560 xz_error(state, Z_STREAM_ERROR,
561 "internal error: inflate stream corrupt");
562 return -1;
563 }
564 /*
565 * FIXME: Remapping a couple of error codes and falling through
566 * to the LZMA error handling looks fragile.
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 if ((state->how != GZIP) &&
594 (ret != LZMA_OK) && (ret != LZMA_STREAM_END)) {
595 xz_error(state, ret, "lzma error");
596 return -1;
597 }
598 } while (strm->avail_out && ret != LZMA_STREAM_END);
599
600 /* update available output and crc check value */
601 state->have = had - strm->avail_out;
602 state->next = strm->next_out - state->have;
603 #ifdef LIBXML_ZLIB_ENABLED
604 state->zstrm.adler =
605 crc32(state->zstrm.adler, state->next, state->have);
606 #endif
607
608 if (ret == LZMA_STREAM_END) {
609 #ifdef LIBXML_ZLIB_ENABLED
610 if (state->how == GZIP) {
611 if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
612 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
613 return -1;
614 }
615 if (crc != state->zstrm.adler) {
616 xz_error(state, LZMA_DATA_ERROR, "incorrect data check");
617 return -1;
618 }
619 if (len != (state->zstrm.total_out & 0xffffffffL)) {
620 xz_error(state, LZMA_DATA_ERROR, "incorrect length check");
621 return -1;
622 }
623 state->strm.avail_in = 0;
624 state->strm.next_in = NULL;
625 state->strm.avail_out = 0;
626 state->strm.next_out = NULL;
627 } else
628 #endif
629 if (strm->avail_in != 0 || !state->eof) {
630 xz_error(state, LZMA_DATA_ERROR, "trailing garbage");
631 return -1;
632 }
633 state->how = LOOK; /* ready for next stream, once have is 0 (leave
634 * state->direct unchanged to remember how) */
635 }
636
637 /* good decompression */
638 return 0;
639 }
640
641 static int
xz_make(xz_statep state)642 xz_make(xz_statep state)
643 {
644 lzma_stream *strm = &(state->strm);
645
646 if (state->how == LOOK) { /* look for lzma / gzip header */
647 if (xz_head(state) == -1)
648 return -1;
649 if (state->have) /* got some data from xz_head() */
650 return 0;
651 }
652 if (state->how == COPY) { /* straight copy */
653 if (xz_load(state, state->out, state->size << 1, &(state->have)) ==
654 -1)
655 return -1;
656 state->next = state->out;
657 } else if (state->how == LZMA || state->how == GZIP) { /* decompress */
658 strm->avail_out = state->size << 1;
659 strm->next_out = state->out;
660 if (xz_decomp(state) == -1)
661 return -1;
662 }
663 return 0;
664 }
665
666 static int
xz_skip(xz_statep state,uint64_t len)667 xz_skip(xz_statep state, uint64_t len)
668 {
669 unsigned n;
670
671 /* skip over len bytes or reach end-of-file, whichever comes first */
672 while (len)
673 /* skip over whatever is in output buffer */
674 if (state->have) {
675 n = (uint64_t) state->have > len ?
676 (unsigned) len : state->have;
677 state->have -= n;
678 state->next += n;
679 state->pos += n;
680 len -= n;
681 }
682
683 /* output buffer empty -- return if we're at the end of the input */
684 else if (state->eof && state->strm.avail_in == 0)
685 break;
686
687 /* need more data to skip -- load up output buffer */
688 else {
689 /* get more output, looking for header if required */
690 if (xz_make(state) == -1)
691 return -1;
692 }
693 return 0;
694 }
695
696 int
__libxml2_xzcompressed(xzFile f)697 __libxml2_xzcompressed(xzFile f) {
698 xz_head(f);
699
700 return xz_compressed(f);
701 }
702
703 int
__libxml2_xzread(xzFile file,void * buf,unsigned len)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
__libxml2_xzclose(xzFile file)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 */
822