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 LIBXML_ZLIB_ENABLED
35 #include <zlib.h>
36 #endif
37 #ifdef LIBXML_LZMA_ENABLED
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 LIBXML_ZLIB_ENABLED
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
xz_error(xz_statep state,int err,const char * msg)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 if ((state->msg =
111 xmlMalloc(strlen(state->path) + strlen(msg) + 3)) == NULL) {
112 state->err = LZMA_MEM_ERROR;
113 state->msg = (char *) "out of memory";
114 return;
115 }
116 strcpy(state->msg, state->path);
117 strcat(state->msg, ": ");
118 strcat(state->msg, msg);
119 return;
120 }
121
122 static void
xz_reset(xz_statep state)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 LIBXML_ZLIB_ENABLED
134 state->zstrm.avail_in = 0; /* no input data yet */
135 #endif
136 }
137
138 static xzFile
xz_open(const char * path,int fd,const char * mode ATTRIBUTE_UNUSED)139 xz_open(const char *path, int fd, const char *mode ATTRIBUTE_UNUSED)
140 {
141 xz_statep state;
142
143 /* allocate xzFile structure to return */
144 state = xmlMalloc(sizeof(xz_state));
145 if (state == NULL)
146 return NULL;
147 state->size = 0; /* no buffers allocated yet */
148 state->want = BUFSIZ; /* requested buffer size */
149 state->msg = NULL; /* no error message yet */
150 state->init = 0; /* initialization of zlib data */
151
152 /* save the path name for error messages */
153 state->path = xmlMalloc(strlen(path) + 1);
154 if (state->path == NULL) {
155 xmlFree(state);
156 return NULL;
157 }
158 strcpy(state->path, path);
159
160 /* open the file with the appropriate mode (or just use fd) */
161 state->fd = fd != -1 ? fd : open(path,
162 #ifdef O_LARGEFILE
163 O_LARGEFILE |
164 #endif
165 #ifdef O_BINARY
166 O_BINARY |
167 #endif
168 O_RDONLY, 0666);
169 if (state->fd == -1) {
170 xmlFree(state->path);
171 xmlFree(state);
172 return NULL;
173 }
174
175 /* save the current position for rewinding (only if reading) */
176 state->start = lseek(state->fd, 0, SEEK_CUR);
177 if (state->start == (uint64_t) - 1)
178 state->start = 0;
179
180 /* initialize stream */
181 xz_reset(state);
182
183 /* return stream */
184 return (xzFile) state;
185 }
186
187 static int
xz_compressed(xzFile f)188 xz_compressed(xzFile f) {
189 xz_statep state;
190
191 if (f == NULL)
192 return(-1);
193 state = (xz_statep) f;
194 if (state->init <= 0)
195 return(-1);
196
197 switch (state->how) {
198 case COPY:
199 return(0);
200 case GZIP:
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 int
__libxml2_xzcompressed(xzFile f)214 __libxml2_xzcompressed(xzFile f) {
215 return xz_compressed(f);
216 }
217
218 xzFile
__libxml2_xzdopen(int fd,const char * mode)219 __libxml2_xzdopen(int fd, const char *mode)
220 {
221 char *path; /* identifier for error messages */
222 xzFile xz;
223
224 if (fd == -1 || (path = xmlMalloc(7 + 3 * sizeof(int))) == NULL)
225 return NULL;
226 sprintf(path, "<fd:%d>", fd); /* for debugging */
227 xz = xz_open(path, fd, mode);
228 xmlFree(path);
229 return xz;
230 }
231
232 static int
xz_load(xz_statep state,unsigned char * buf,unsigned int len,unsigned int * have)233 xz_load(xz_statep state, unsigned char *buf, unsigned int len,
234 unsigned int *have)
235 {
236 int ret;
237
238 *have = 0;
239 do {
240 ret = read(state->fd, buf + *have, len - *have);
241 if (ret <= 0)
242 break;
243 *have += ret;
244 } while (*have < len);
245 if (ret < 0) {
246 xz_error(state, -1, strerror(errno));
247 return -1;
248 }
249 if (ret == 0)
250 state->eof = 1;
251 return 0;
252 }
253
254 static int
xz_avail(xz_statep state)255 xz_avail(xz_statep state)
256 {
257 lzma_stream *strm = &(state->strm);
258
259 if (state->err != LZMA_OK)
260 return -1;
261 if (state->eof == 0) {
262 /* avail_in is size_t, which is not necessary sizeof(unsigned) */
263 unsigned tmp = strm->avail_in;
264
265 if (xz_load(state, state->in, state->size, &tmp) == -1) {
266 strm->avail_in = tmp;
267 return -1;
268 }
269 strm->avail_in = tmp;
270 strm->next_in = state->in;
271 }
272 return 0;
273 }
274
275 #ifdef LIBXML_ZLIB_ENABLED
276 static int
xz_avail_zstrm(xz_statep state)277 xz_avail_zstrm(xz_statep state)
278 {
279 int ret;
280 state->strm.avail_in = state->zstrm.avail_in;
281 state->strm.next_in = state->zstrm.next_in;
282 ret = xz_avail(state);
283 state->zstrm.avail_in = (uInt) state->strm.avail_in;
284 state->zstrm.next_in = (Bytef *) state->strm.next_in;
285 return ret;
286 }
287 #endif
288
289 static int
is_format_xz(xz_statep state)290 is_format_xz(xz_statep state)
291 {
292 lzma_stream *strm = &(state->strm);
293
294 return strm->avail_in >= 6 && memcmp(state->in, "\3757zXZ", 6) == 0;
295 }
296
297 static int
is_format_lzma(xz_statep state)298 is_format_lzma(xz_statep state)
299 {
300 lzma_stream *strm = &(state->strm);
301
302 lzma_filter filter;
303 lzma_options_lzma *opt;
304 uint32_t dict_size;
305 uint64_t uncompressed_size;
306 size_t i;
307
308 if (strm->avail_in < 13)
309 return 0;
310
311 filter.id = LZMA_FILTER_LZMA1;
312 if (lzma_properties_decode(&filter, NULL, state->in, 5) != LZMA_OK)
313 return 0;
314
315 opt = filter.options;
316 dict_size = opt->dict_size;
317 free(opt); /* we can't use xmlFree on a string returned by zlib */
318
319 /* A hack to ditch tons of false positives: We allow only dictionary
320 * sizes that are 2^n or 2^n + 2^(n-1) or UINT32_MAX. LZMA_Alone
321 * created only files with 2^n, but accepts any dictionary size.
322 * If someone complains, this will be reconsidered.
323 */
324 if (dict_size != UINT32_MAX) {
325 uint32_t d = dict_size - 1;
326
327 d |= d >> 2;
328 d |= d >> 3;
329 d |= d >> 4;
330 d |= d >> 8;
331 d |= d >> 16;
332 ++d;
333 if (d != dict_size || dict_size == 0)
334 return 0;
335 }
336
337 /* Another hack to ditch false positives: Assume that if the
338 * uncompressed size is known, it must be less than 256 GiB.
339 * Again, if someone complains, this will be reconsidered.
340 */
341 uncompressed_size = 0;
342 for (i = 0; i < 8; ++i)
343 uncompressed_size |= (uint64_t) (state->in[5 + i]) << (i * 8);
344
345 if (uncompressed_size != UINT64_MAX
346 && uncompressed_size > (UINT64_C(1) << 38))
347 return 0;
348
349 return 1;
350 }
351
352 #ifdef LIBXML_ZLIB_ENABLED
353
354 /* Get next byte from input, or -1 if end or error. */
355 #define NEXT() ((strm->avail_in == 0 && xz_avail(state) == -1) ? -1 : \
356 (strm->avail_in == 0 ? -1 : \
357 (strm->avail_in--, *(strm->next_in)++)))
358 /* Same thing, but from zstrm */
359 #define NEXTZ() ((strm->avail_in == 0 && xz_avail_zstrm(state) == -1) ? -1 : \
360 (strm->avail_in == 0 ? -1 : \
361 (strm->avail_in--, *(strm->next_in)++)))
362
363 /* Get a four-byte little-endian integer and return 0 on success and the value
364 in *ret. Otherwise -1 is returned and *ret is not modified. */
365 static int
gz_next4(xz_statep state,unsigned long * ret)366 gz_next4(xz_statep state, unsigned long *ret)
367 {
368 int ch;
369 unsigned long val;
370 z_streamp strm = &(state->zstrm);
371
372 val = NEXTZ();
373 val += (unsigned) NEXTZ() << 8;
374 val += (unsigned long) NEXTZ() << 16;
375 ch = NEXTZ();
376 if (ch == -1)
377 return -1;
378 val += (unsigned long) ch << 24;
379 *ret = val;
380 return 0;
381 }
382 #endif
383
384 static int
xz_head(xz_statep state)385 xz_head(xz_statep state)
386 {
387 lzma_stream *strm = &(state->strm);
388 lzma_stream init = LZMA_STREAM_INIT;
389 int flags;
390 unsigned len;
391
392 /* allocate read buffers and inflate memory */
393 if (state->size == 0) {
394 /* allocate buffers */
395 state->in = xmlMalloc(state->want);
396 state->out = xmlMalloc(state->want << 1);
397 if (state->in == NULL || state->out == NULL) {
398 if (state->out != NULL)
399 xmlFree(state->out);
400 if (state->in != NULL)
401 xmlFree(state->in);
402 xz_error(state, LZMA_MEM_ERROR, "out of memory");
403 return -1;
404 }
405 state->size = state->want;
406
407 /* allocate decoder memory */
408 state->strm = init;
409 state->strm.avail_in = 0;
410 state->strm.next_in = NULL;
411 if (lzma_auto_decoder(&state->strm, 100000000, 0) != LZMA_OK) {
412 xmlFree(state->out);
413 xmlFree(state->in);
414 state->size = 0;
415 xz_error(state, LZMA_MEM_ERROR, "out of memory");
416 return -1;
417 }
418 #ifdef LIBXML_ZLIB_ENABLED
419 /* allocate inflate memory */
420 state->zstrm.zalloc = Z_NULL;
421 state->zstrm.zfree = Z_NULL;
422 state->zstrm.opaque = Z_NULL;
423 state->zstrm.avail_in = 0;
424 state->zstrm.next_in = Z_NULL;
425 if (state->init == 0) {
426 if (inflateInit2(&(state->zstrm), -15) != Z_OK) {/* raw inflate */
427 xmlFree(state->out);
428 xmlFree(state->in);
429 state->size = 0;
430 xz_error(state, LZMA_MEM_ERROR, "out of memory");
431 return -1;
432 }
433 state->init = 1;
434 }
435 #endif
436 }
437
438 /* get some data in the input buffer */
439 if (strm->avail_in == 0) {
440 if (xz_avail(state) == -1)
441 return -1;
442 if (strm->avail_in == 0)
443 return 0;
444 }
445
446 /* look for the xz magic header bytes */
447 if (is_format_xz(state) || is_format_lzma(state)) {
448 state->how = LZMA;
449 state->direct = 0;
450 return 0;
451 }
452 #ifdef LIBXML_ZLIB_ENABLED
453 /* look for the gzip magic header bytes 31 and 139 */
454 if (strm->next_in[0] == 31) {
455 strm->avail_in--;
456 strm->next_in++;
457 if (strm->avail_in == 0 && xz_avail(state) == -1)
458 return -1;
459 if (strm->avail_in && strm->next_in[0] == 139) {
460 /* we have a gzip header, woo hoo! */
461 strm->avail_in--;
462 strm->next_in++;
463
464 /* skip rest of header */
465 if (NEXT() != 8) { /* compression method */
466 xz_error(state, LZMA_DATA_ERROR,
467 "unknown compression method");
468 return -1;
469 }
470 flags = NEXT();
471 if (flags & 0xe0) { /* reserved flag bits */
472 xz_error(state, LZMA_DATA_ERROR,
473 "unknown header flags set");
474 return -1;
475 }
476 NEXT(); /* modification time */
477 NEXT();
478 NEXT();
479 NEXT();
480 NEXT(); /* extra flags */
481 NEXT(); /* operating system */
482 if (flags & 4) { /* extra field */
483 len = (unsigned) NEXT();
484 len += (unsigned) NEXT() << 8;
485 while (len--)
486 if (NEXT() < 0)
487 break;
488 }
489 if (flags & 8) /* file name */
490 while (NEXT() > 0) ;
491 if (flags & 16) /* comment */
492 while (NEXT() > 0) ;
493 if (flags & 2) { /* header crc */
494 NEXT();
495 NEXT();
496 }
497 /* an unexpected end of file is not checked for here -- it will be
498 * noticed on the first request for uncompressed data */
499
500 /* set up for decompression */
501 inflateReset(&state->zstrm);
502 state->zstrm.adler = crc32(0L, Z_NULL, 0);
503 state->how = GZIP;
504 state->direct = 0;
505 return 0;
506 } else {
507 /* not a gzip file -- save first byte (31) and fall to raw i/o */
508 state->out[0] = 31;
509 state->have = 1;
510 }
511 }
512 #endif
513
514 /* doing raw i/o, save start of raw data for seeking, copy any leftover
515 * input to output -- this assumes that the output buffer is larger than
516 * the input buffer, which also assures space for gzungetc() */
517 state->raw = state->pos;
518 state->next = state->out;
519 if (strm->avail_in) {
520 memcpy(state->next + state->have, strm->next_in, strm->avail_in);
521 state->have += strm->avail_in;
522 strm->avail_in = 0;
523 }
524 state->how = COPY;
525 state->direct = 1;
526 return 0;
527 }
528
529 static int
xz_decomp(xz_statep state)530 xz_decomp(xz_statep state)
531 {
532 int ret;
533 unsigned had;
534 unsigned long crc, len;
535 lzma_stream *strm = &(state->strm);
536
537 lzma_action action = LZMA_RUN;
538
539 /* fill output buffer up to end of deflate stream */
540 had = strm->avail_out;
541 do {
542 /* get more input for inflate() */
543 if (strm->avail_in == 0 && xz_avail(state) == -1)
544 return -1;
545 if (strm->avail_in == 0) {
546 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
547 return -1;
548 }
549 if (state->eof)
550 action = LZMA_FINISH;
551
552 /* decompress and handle errors */
553 #ifdef LIBXML_ZLIB_ENABLED
554 if (state->how == GZIP) {
555 state->zstrm.avail_in = (uInt) state->strm.avail_in;
556 state->zstrm.next_in = (Bytef *) state->strm.next_in;
557 state->zstrm.avail_out = (uInt) state->strm.avail_out;
558 state->zstrm.next_out = (Bytef *) state->strm.next_out;
559 ret = inflate(&state->zstrm, Z_NO_FLUSH);
560 if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
561 xz_error(state, Z_STREAM_ERROR,
562 "internal error: inflate stream corrupt");
563 return -1;
564 }
565 /*
566 * FIXME: Remapping a couple of error codes and falling through
567 * to the LZMA error handling looks fragile.
568 */
569 if (ret == Z_MEM_ERROR)
570 ret = LZMA_MEM_ERROR;
571 if (ret == Z_DATA_ERROR)
572 ret = LZMA_DATA_ERROR;
573 if (ret == Z_STREAM_END)
574 ret = LZMA_STREAM_END;
575 state->strm.avail_in = state->zstrm.avail_in;
576 state->strm.next_in = state->zstrm.next_in;
577 state->strm.avail_out = state->zstrm.avail_out;
578 state->strm.next_out = state->zstrm.next_out;
579 } else /* state->how == LZMA */
580 #endif
581 ret = lzma_code(strm, action);
582 if (ret == LZMA_MEM_ERROR) {
583 xz_error(state, LZMA_MEM_ERROR, "out of memory");
584 return -1;
585 }
586 if (ret == LZMA_DATA_ERROR) {
587 xz_error(state, LZMA_DATA_ERROR, "compressed data error");
588 return -1;
589 }
590 if (ret == LZMA_PROG_ERROR) {
591 xz_error(state, LZMA_PROG_ERROR, "compression error");
592 return -1;
593 }
594 if ((state->how != GZIP) &&
595 (ret != LZMA_OK) && (ret != LZMA_STREAM_END)) {
596 xz_error(state, ret, "lzma error");
597 return -1;
598 }
599 } while (strm->avail_out && ret != LZMA_STREAM_END);
600
601 /* update available output and crc check value */
602 state->have = had - strm->avail_out;
603 state->next = strm->next_out - state->have;
604 #ifdef LIBXML_ZLIB_ENABLED
605 state->zstrm.adler =
606 crc32(state->zstrm.adler, state->next, state->have);
607 #endif
608
609 if (ret == LZMA_STREAM_END) {
610 #ifdef LIBXML_ZLIB_ENABLED
611 if (state->how == GZIP) {
612 if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) {
613 xz_error(state, LZMA_DATA_ERROR, "unexpected end of file");
614 return -1;
615 }
616 if (crc != state->zstrm.adler) {
617 xz_error(state, LZMA_DATA_ERROR, "incorrect data check");
618 return -1;
619 }
620 if (len != (state->zstrm.total_out & 0xffffffffL)) {
621 xz_error(state, LZMA_DATA_ERROR, "incorrect length check");
622 return -1;
623 }
624 state->strm.avail_in = 0;
625 state->strm.next_in = NULL;
626 state->strm.avail_out = 0;
627 state->strm.next_out = NULL;
628 } else
629 #endif
630 if (strm->avail_in != 0 || !state->eof) {
631 xz_error(state, LZMA_DATA_ERROR, "trailing garbage");
632 return -1;
633 }
634 state->how = LOOK; /* ready for next stream, once have is 0 (leave
635 * state->direct unchanged to remember how) */
636 }
637
638 /* good decompression */
639 return 0;
640 }
641
642 static int
xz_make(xz_statep state)643 xz_make(xz_statep state)
644 {
645 lzma_stream *strm = &(state->strm);
646
647 if (state->how == LOOK) { /* look for lzma / gzip header */
648 if (xz_head(state) == -1)
649 return -1;
650 if (state->have) /* got some data from xz_head() */
651 return 0;
652 }
653 if (state->how == COPY) { /* straight copy */
654 if (xz_load(state, state->out, state->size << 1, &(state->have)) ==
655 -1)
656 return -1;
657 state->next = state->out;
658 } else if (state->how == LZMA || state->how == GZIP) { /* decompress */
659 strm->avail_out = state->size << 1;
660 strm->next_out = state->out;
661 if (xz_decomp(state) == -1)
662 return -1;
663 }
664 return 0;
665 }
666
667 static int
xz_skip(xz_statep state,uint64_t len)668 xz_skip(xz_statep state, uint64_t len)
669 {
670 unsigned n;
671
672 /* skip over len bytes or reach end-of-file, whichever comes first */
673 while (len)
674 /* skip over whatever is in output buffer */
675 if (state->have) {
676 n = (uint64_t) state->have > len ?
677 (unsigned) len : state->have;
678 state->have -= n;
679 state->next += n;
680 state->pos += n;
681 len -= n;
682 }
683
684 /* output buffer empty -- return if we're at the end of the input */
685 else if (state->eof && state->strm.avail_in == 0)
686 break;
687
688 /* need more data to skip -- load up output buffer */
689 else {
690 /* get more output, looking for header if required */
691 if (xz_make(state) == -1)
692 return -1;
693 }
694 return 0;
695 }
696
697 int
__libxml2_xzread(xzFile file,void * buf,unsigned len)698 __libxml2_xzread(xzFile file, void *buf, unsigned len)
699 {
700 unsigned got, n;
701 xz_statep state;
702 lzma_stream *strm;
703
704 /* get internal structure */
705 if (file == NULL)
706 return -1;
707 state = (xz_statep) file;
708 strm = &(state->strm);
709
710 /* check that we're reading and that there's no error */
711 if (state->err != LZMA_OK)
712 return -1;
713
714 /* since an int is returned, make sure len fits in one, otherwise return
715 * with an error (this avoids the flaw in the interface) */
716 if ((int) len < 0) {
717 xz_error(state, LZMA_BUF_ERROR,
718 "requested length does not fit in int");
719 return -1;
720 }
721
722 /* if len is zero, avoid unnecessary operations */
723 if (len == 0)
724 return 0;
725
726 /* process a skip request */
727 if (state->seek) {
728 state->seek = 0;
729 if (xz_skip(state, state->skip) == -1)
730 return -1;
731 }
732
733 /* get len bytes to buf, or less than len if at the end */
734 got = 0;
735 do {
736 /* first just try copying data from the output buffer */
737 if (state->have) {
738 n = state->have > len ? len : state->have;
739 memcpy(buf, state->next, n);
740 state->next += n;
741 state->have -= n;
742 }
743
744 /* output buffer empty -- return if we're at the end of the input */
745 else if (state->eof && strm->avail_in == 0)
746 break;
747
748 /* need output data -- for small len or new stream load up our output
749 * buffer */
750 else if (state->how == LOOK || len < (state->size << 1)) {
751 /* get more output, looking for header if required */
752 if (xz_make(state) == -1)
753 return -1;
754 continue; /* no progress yet -- go back to memcpy() above */
755 /* the copy above assures that we will leave with space in the
756 * output buffer, allowing at least one gzungetc() to succeed */
757 }
758
759 /* large len -- read directly into user buffer */
760 else if (state->how == COPY) { /* read directly */
761 if (xz_load(state, buf, len, &n) == -1)
762 return -1;
763 }
764
765 /* large len -- decompress directly into user buffer */
766 else { /* state->how == LZMA */
767 strm->avail_out = len;
768 strm->next_out = buf;
769 if (xz_decomp(state) == -1)
770 return -1;
771 n = state->have;
772 state->have = 0;
773 }
774
775 /* update progress */
776 len -= n;
777 buf = (char *) buf + n;
778 got += n;
779 state->pos += n;
780 } while (len);
781
782 /* return number of bytes read into user buffer (will fit in int) */
783 return (int) got;
784 }
785
786 int
__libxml2_xzclose(xzFile file)787 __libxml2_xzclose(xzFile file)
788 {
789 int ret;
790 xz_statep state;
791
792 /* get internal structure */
793 if (file == NULL)
794 return LZMA_DATA_ERROR;
795 state = (xz_statep) file;
796
797 /* free memory and close file */
798 if (state->size) {
799 lzma_end(&(state->strm));
800 #ifdef LIBXML_ZLIB_ENABLED
801 if (state->init == 1)
802 inflateEnd(&(state->zstrm));
803 state->init = 0;
804 #endif
805 xmlFree(state->out);
806 xmlFree(state->in);
807 }
808 xmlFree(state->path);
809 if ((state->msg != NULL) && (state->err != LZMA_MEM_ERROR))
810 xmlFree(state->msg);
811 ret = close(state->fd);
812 xmlFree(state);
813 return ret ? ret : LZMA_OK;
814 }
815 #endif /* LIBXML_LZMA_ENABLED */
816