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1 | /* gzlib.c -- zlib functions common to reading and writing gzip files |
2 | * Copyright (C) 2004, 2010, 2011, 2012 Mark Adler | |
3 | * For conditions of distribution and use, see copyright notice in zlib.h | |
4 | */ | |
5 | ||
6 | #include "gzguts.h" | |
7 | ||
8 | #if defined(_WIN32) && !defined(__BORLANDC__) | |
9 | # define LSEEK _lseeki64 | |
10 | #else | |
11 | #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 | |
12 | # define LSEEK lseek64 | |
13 | #else | |
14 | # define LSEEK lseek | |
15 | #endif | |
16 | #endif | |
17 | ||
18 | /* Local functions */ | |
19 | local void gz_reset OF((gz_statep)); | |
20 | local gzFile gz_open OF((const void *, int, const char *)); | |
21 | ||
22 | #if defined UNDER_CE | |
23 | ||
24 | /* Map the Windows error number in ERROR to a locale-dependent error message | |
25 | string and return a pointer to it. Typically, the values for ERROR come | |
26 | from GetLastError. | |
27 | ||
28 | The string pointed to shall not be modified by the application, but may be | |
29 | overwritten by a subsequent call to gz_strwinerror | |
30 | ||
31 | The gz_strwinerror function does not change the current setting of | |
32 | GetLastError. */ | |
33 | char ZLIB_INTERNAL *gz_strwinerror (error) | |
34 | DWORD error; | |
35 | { | |
36 | static char buf[1024]; | |
37 | ||
38 | wchar_t *msgbuf; | |
39 | DWORD lasterr = GetLastError(); | |
40 | DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | |
41 | | FORMAT_MESSAGE_ALLOCATE_BUFFER, | |
42 | NULL, | |
43 | error, | |
44 | 0, /* Default language */ | |
45 | (LPVOID)&msgbuf, | |
46 | 0, | |
47 | NULL); | |
48 | if (chars != 0) { | |
49 | /* If there is an \r\n appended, zap it. */ | |
50 | if (chars >= 2 | |
51 | && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') { | |
52 | chars -= 2; | |
53 | msgbuf[chars] = 0; | |
54 | } | |
55 | ||
56 | if (chars > sizeof (buf) - 1) { | |
57 | chars = sizeof (buf) - 1; | |
58 | msgbuf[chars] = 0; | |
59 | } | |
60 | ||
61 | wcstombs(buf, msgbuf, chars + 1); | |
62 | LocalFree(msgbuf); | |
63 | } | |
64 | else { | |
65 | sprintf(buf, "unknown win32 error (%ld)", error); | |
66 | } | |
67 | ||
68 | SetLastError(lasterr); | |
69 | return buf; | |
70 | } | |
71 | ||
72 | #endif /* UNDER_CE */ | |
73 | ||
74 | /* Reset gzip file state */ | |
75 | local void gz_reset(state) | |
76 | gz_statep state; | |
77 | { | |
78 | state->x.have = 0; /* no output data available */ | |
79 | if (state->mode == GZ_READ) { /* for reading ... */ | |
80 | state->eof = 0; /* not at end of file */ | |
81 | state->past = 0; /* have not read past end yet */ | |
82 | state->how = LOOK; /* look for gzip header */ | |
83 | } | |
84 | state->seek = 0; /* no seek request pending */ | |
85 | gz_error(state, Z_OK, NULL); /* clear error */ | |
86 | state->x.pos = 0; /* no uncompressed data yet */ | |
87 | state->strm.avail_in = 0; /* no input data yet */ | |
88 | } | |
89 | ||
90 | /* Open a gzip file either by name or file descriptor. */ | |
91 | local gzFile gz_open(path, fd, mode) | |
92 | const void *path; | |
93 | int fd; | |
94 | const char *mode; | |
95 | { | |
96 | gz_statep state; | |
97 | size_t len; | |
98 | int oflag; | |
99 | #ifdef O_CLOEXEC | |
100 | int cloexec = 0; | |
101 | #endif | |
102 | #ifdef O_EXCL | |
103 | int exclusive = 0; | |
104 | #endif | |
105 | ||
106 | /* check input */ | |
107 | if (path == NULL) | |
108 | return NULL; | |
109 | ||
110 | /* allocate gzFile structure to return */ | |
111 | state = malloc(sizeof(gz_state)); | |
112 | if (state == NULL) | |
113 | return NULL; | |
114 | state->size = 0; /* no buffers allocated yet */ | |
115 | state->want = GZBUFSIZE; /* requested buffer size */ | |
116 | state->msg = NULL; /* no error message yet */ | |
117 | ||
118 | /* interpret mode */ | |
119 | state->mode = GZ_NONE; | |
120 | state->level = Z_DEFAULT_COMPRESSION; | |
121 | state->strategy = Z_DEFAULT_STRATEGY; | |
122 | state->direct = 0; | |
123 | while (*mode) { | |
124 | if (*mode >= '0' && *mode <= '9') | |
125 | state->level = *mode - '0'; | |
126 | else | |
127 | switch (*mode) { | |
128 | case 'r': | |
129 | state->mode = GZ_READ; | |
130 | break; | |
131 | #ifndef NO_GZCOMPRESS | |
132 | case 'w': | |
133 | state->mode = GZ_WRITE; | |
134 | break; | |
135 | case 'a': | |
136 | state->mode = GZ_APPEND; | |
137 | break; | |
138 | #endif | |
139 | case '+': /* can't read and write at the same time */ | |
140 | free(state); | |
141 | return NULL; | |
142 | case 'b': /* ignore -- will request binary anyway */ | |
143 | break; | |
144 | #ifdef O_CLOEXEC | |
145 | case 'e': | |
146 | cloexec = 1; | |
147 | break; | |
148 | #endif | |
149 | #ifdef O_EXCL | |
150 | case 'x': | |
151 | exclusive = 1; | |
152 | break; | |
153 | #endif | |
154 | case 'f': | |
155 | state->strategy = Z_FILTERED; | |
156 | break; | |
157 | case 'h': | |
158 | state->strategy = Z_HUFFMAN_ONLY; | |
159 | break; | |
160 | case 'R': | |
161 | state->strategy = Z_RLE; | |
162 | break; | |
163 | case 'F': | |
164 | state->strategy = Z_FIXED; | |
165 | case 'T': | |
166 | state->direct = 1; | |
167 | default: /* could consider as an error, but just ignore */ | |
168 | ; | |
169 | } | |
170 | mode++; | |
171 | } | |
172 | ||
173 | /* must provide an "r", "w", or "a" */ | |
174 | if (state->mode == GZ_NONE) { | |
175 | free(state); | |
176 | return NULL; | |
177 | } | |
178 | ||
179 | /* can't force transparent read */ | |
180 | if (state->mode == GZ_READ) { | |
181 | if (state->direct) { | |
182 | free(state); | |
183 | return NULL; | |
184 | } | |
185 | state->direct = 1; /* for empty file */ | |
186 | } | |
187 | ||
188 | /* save the path name for error messages */ | |
189 | #ifdef _WIN32 | |
190 | if (fd == -2) { | |
191 | len = wcstombs(NULL, path, 0); | |
192 | if (len == (size_t)-1) | |
193 | len = 0; | |
194 | } | |
195 | else | |
196 | #endif | |
197 | len = strlen(path); | |
198 | state->path = malloc(len + 1); | |
199 | if (state->path == NULL) { | |
200 | free(state); | |
201 | return NULL; | |
202 | } | |
203 | #ifdef _WIN32 | |
204 | if (fd == -2) | |
205 | if (len) | |
206 | wcstombs(state->path, path, len + 1); | |
207 | else | |
208 | *(state->path) = 0; | |
209 | else | |
210 | #endif | |
211 | strcpy(state->path, path); | |
212 | ||
213 | /* compute the flags for open() */ | |
214 | oflag = | |
215 | #ifdef O_LARGEFILE | |
216 | O_LARGEFILE | | |
217 | #endif | |
218 | #ifdef O_BINARY | |
219 | O_BINARY | | |
220 | #endif | |
221 | #ifdef O_CLOEXEC | |
222 | (cloexec ? O_CLOEXEC : 0) | | |
223 | #endif | |
224 | (state->mode == GZ_READ ? | |
225 | O_RDONLY : | |
226 | (O_WRONLY | O_CREAT | | |
227 | #ifdef O_EXCL | |
228 | (exclusive ? O_EXCL : 0) | | |
229 | #endif | |
230 | (state->mode == GZ_WRITE ? | |
231 | O_TRUNC : | |
232 | O_APPEND))); | |
233 | ||
234 | /* open the file with the appropriate flags (or just use fd) */ | |
235 | state->fd = fd > -1 ? fd : ( | |
236 | #ifdef _WIN32 | |
237 | fd == -2 ? _wopen(path, oflag, 0666) : | |
238 | #endif | |
239 | open(path, oflag, 0666)); | |
240 | if (state->fd == -1) { | |
241 | free(state->path); | |
242 | free(state); | |
243 | return NULL; | |
244 | } | |
245 | if (state->mode == GZ_APPEND) | |
246 | state->mode = GZ_WRITE; /* simplify later checks */ | |
247 | ||
248 | /* save the current position for rewinding (only if reading) */ | |
249 | if (state->mode == GZ_READ) { | |
250 | state->start = LSEEK(state->fd, 0, SEEK_CUR); | |
251 | if (state->start == -1) state->start = 0; | |
252 | } | |
253 | ||
254 | /* initialize stream */ | |
255 | gz_reset(state); | |
256 | ||
257 | /* return stream */ | |
258 | return (gzFile)state; | |
259 | } | |
260 | ||
261 | /* -- see zlib.h -- */ | |
262 | gzFile ZEXPORT gzopen(path, mode) | |
263 | const char *path; | |
264 | const char *mode; | |
265 | { | |
266 | return gz_open(path, -1, mode); | |
267 | } | |
268 | ||
269 | /* -- see zlib.h -- */ | |
270 | gzFile ZEXPORT gzopen64(path, mode) | |
271 | const char *path; | |
272 | const char *mode; | |
273 | { | |
274 | return gz_open(path, -1, mode); | |
275 | } | |
276 | ||
277 | /* -- see zlib.h -- */ | |
278 | gzFile ZEXPORT gzdopen(fd, mode) | |
279 | int fd; | |
280 | const char *mode; | |
281 | { | |
282 | char *path; /* identifier for error messages */ | |
283 | gzFile gz; | |
284 | ||
285 | if (fd == -1 || (path = malloc(7 + 3 * sizeof(int))) == NULL) | |
286 | return NULL; | |
287 | sprintf(path, "<fd:%d>", fd); /* for debugging */ | |
288 | gz = gz_open(path, fd, mode); | |
289 | free(path); | |
290 | return gz; | |
291 | } | |
292 | ||
293 | /* -- see zlib.h -- */ | |
294 | #ifdef _WIN32 | |
295 | gzFile ZEXPORT gzopen_w(path, mode) | |
296 | const wchar_t *path; | |
297 | const char *mode; | |
298 | { | |
299 | return gz_open(path, -2, mode); | |
300 | } | |
301 | #endif | |
302 | ||
303 | /* -- see zlib.h -- */ | |
304 | int ZEXPORT gzbuffer(file, size) | |
305 | gzFile file; | |
306 | unsigned size; | |
307 | { | |
308 | gz_statep state; | |
309 | ||
310 | /* get internal structure and check integrity */ | |
311 | if (file == NULL) | |
312 | return -1; | |
313 | state = (gz_statep)file; | |
314 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
315 | return -1; | |
316 | ||
317 | /* make sure we haven't already allocated memory */ | |
318 | if (state->size != 0) | |
319 | return -1; | |
320 | ||
321 | /* check and set requested size */ | |
322 | if (size < 2) | |
323 | size = 2; /* need two bytes to check magic header */ | |
324 | state->want = size; | |
325 | return 0; | |
326 | } | |
327 | ||
328 | /* -- see zlib.h -- */ | |
329 | int ZEXPORT gzrewind(file) | |
330 | gzFile file; | |
331 | { | |
332 | gz_statep state; | |
333 | ||
334 | /* get internal structure */ | |
335 | if (file == NULL) | |
336 | return -1; | |
337 | state = (gz_statep)file; | |
338 | ||
339 | /* check that we're reading and that there's no error */ | |
340 | if (state->mode != GZ_READ || | |
341 | (state->err != Z_OK && state->err != Z_BUF_ERROR)) | |
342 | return -1; | |
343 | ||
344 | /* back up and start over */ | |
345 | if (LSEEK(state->fd, state->start, SEEK_SET) == -1) | |
346 | return -1; | |
347 | gz_reset(state); | |
348 | return 0; | |
349 | } | |
350 | ||
351 | /* -- see zlib.h -- */ | |
352 | z_off64_t ZEXPORT gzseek64(file, offset, whence) | |
353 | gzFile file; | |
354 | z_off64_t offset; | |
355 | int whence; | |
356 | { | |
357 | unsigned n; | |
358 | z_off64_t ret; | |
359 | gz_statep state; | |
360 | ||
361 | /* get internal structure and check integrity */ | |
362 | if (file == NULL) | |
363 | return -1; | |
364 | state = (gz_statep)file; | |
365 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
366 | return -1; | |
367 | ||
368 | /* check that there's no error */ | |
369 | if (state->err != Z_OK && state->err != Z_BUF_ERROR) | |
370 | return -1; | |
371 | ||
372 | /* can only seek from start or relative to current position */ | |
373 | if (whence != SEEK_SET && whence != SEEK_CUR) | |
374 | return -1; | |
375 | ||
376 | /* normalize offset to a SEEK_CUR specification */ | |
377 | if (whence == SEEK_SET) | |
378 | offset -= state->x.pos; | |
379 | else if (state->seek) | |
380 | offset += state->skip; | |
381 | state->seek = 0; | |
382 | ||
383 | /* if within raw area while reading, just go there */ | |
384 | if (state->mode == GZ_READ && state->how == COPY && | |
385 | state->x.pos + offset >= 0) { | |
386 | ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR); | |
387 | if (ret == -1) | |
388 | return -1; | |
389 | state->x.have = 0; | |
390 | state->eof = 0; | |
391 | state->past = 0; | |
392 | state->seek = 0; | |
393 | gz_error(state, Z_OK, NULL); | |
394 | state->strm.avail_in = 0; | |
395 | state->x.pos += offset; | |
396 | return state->x.pos; | |
397 | } | |
398 | ||
399 | /* calculate skip amount, rewinding if needed for back seek when reading */ | |
400 | if (offset < 0) { | |
401 | if (state->mode != GZ_READ) /* writing -- can't go backwards */ | |
402 | return -1; | |
403 | offset += state->x.pos; | |
404 | if (offset < 0) /* before start of file! */ | |
405 | return -1; | |
406 | if (gzrewind(file) == -1) /* rewind, then skip to offset */ | |
407 | return -1; | |
408 | } | |
409 | ||
410 | /* if reading, skip what's in output buffer (one less gzgetc() check) */ | |
411 | if (state->mode == GZ_READ) { | |
412 | n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ? | |
413 | (unsigned)offset : state->x.have; | |
414 | state->x.have -= n; | |
415 | state->x.next += n; | |
416 | state->x.pos += n; | |
417 | offset -= n; | |
418 | } | |
419 | ||
420 | /* request skip (if not zero) */ | |
421 | if (offset) { | |
422 | state->seek = 1; | |
423 | state->skip = offset; | |
424 | } | |
425 | return state->x.pos + offset; | |
426 | } | |
427 | ||
428 | /* -- see zlib.h -- */ | |
429 | z_off_t ZEXPORT gzseek(file, offset, whence) | |
430 | gzFile file; | |
431 | z_off_t offset; | |
432 | int whence; | |
433 | { | |
434 | z_off64_t ret; | |
435 | ||
436 | ret = gzseek64(file, (z_off64_t)offset, whence); | |
437 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; | |
438 | } | |
439 | ||
440 | /* -- see zlib.h -- */ | |
441 | z_off64_t ZEXPORT gztell64(file) | |
442 | gzFile file; | |
443 | { | |
444 | gz_statep state; | |
445 | ||
446 | /* get internal structure and check integrity */ | |
447 | if (file == NULL) | |
448 | return -1; | |
449 | state = (gz_statep)file; | |
450 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
451 | return -1; | |
452 | ||
453 | /* return position */ | |
454 | return state->x.pos + (state->seek ? state->skip : 0); | |
455 | } | |
456 | ||
457 | /* -- see zlib.h -- */ | |
458 | z_off_t ZEXPORT gztell(file) | |
459 | gzFile file; | |
460 | { | |
461 | z_off64_t ret; | |
462 | ||
463 | ret = gztell64(file); | |
464 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; | |
465 | } | |
466 | ||
467 | /* -- see zlib.h -- */ | |
468 | z_off64_t ZEXPORT gzoffset64(file) | |
469 | gzFile file; | |
470 | { | |
471 | z_off64_t offset; | |
472 | gz_statep state; | |
473 | ||
474 | /* get internal structure and check integrity */ | |
475 | if (file == NULL) | |
476 | return -1; | |
477 | state = (gz_statep)file; | |
478 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
479 | return -1; | |
480 | ||
481 | /* compute and return effective offset in file */ | |
482 | offset = LSEEK(state->fd, 0, SEEK_CUR); | |
483 | if (offset == -1) | |
484 | return -1; | |
485 | if (state->mode == GZ_READ) /* reading */ | |
486 | offset -= state->strm.avail_in; /* don't count buffered input */ | |
487 | return offset; | |
488 | } | |
489 | ||
490 | /* -- see zlib.h -- */ | |
491 | z_off_t ZEXPORT gzoffset(file) | |
492 | gzFile file; | |
493 | { | |
494 | z_off64_t ret; | |
495 | ||
496 | ret = gzoffset64(file); | |
497 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; | |
498 | } | |
499 | ||
500 | /* -- see zlib.h -- */ | |
501 | int ZEXPORT gzeof(file) | |
502 | gzFile file; | |
503 | { | |
504 | gz_statep state; | |
505 | ||
506 | /* get internal structure and check integrity */ | |
507 | if (file == NULL) | |
508 | return 0; | |
509 | state = (gz_statep)file; | |
510 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
511 | return 0; | |
512 | ||
513 | /* return end-of-file state */ | |
514 | return state->mode == GZ_READ ? state->past : 0; | |
515 | } | |
516 | ||
517 | /* -- see zlib.h -- */ | |
518 | const char * ZEXPORT gzerror(file, errnum) | |
519 | gzFile file; | |
520 | int *errnum; | |
521 | { | |
522 | gz_statep state; | |
523 | ||
524 | /* get internal structure and check integrity */ | |
525 | if (file == NULL) | |
526 | return NULL; | |
527 | state = (gz_statep)file; | |
528 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
529 | return NULL; | |
530 | ||
531 | /* return error information */ | |
532 | if (errnum != NULL) | |
533 | *errnum = state->err; | |
534 | return state->msg == NULL ? "" : state->msg; | |
535 | } | |
536 | ||
537 | /* -- see zlib.h -- */ | |
538 | void ZEXPORT gzclearerr(file) | |
539 | gzFile file; | |
540 | { | |
541 | gz_statep state; | |
542 | ||
543 | /* get internal structure and check integrity */ | |
544 | if (file == NULL) | |
545 | return; | |
546 | state = (gz_statep)file; | |
547 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
548 | return; | |
549 | ||
550 | /* clear error and end-of-file */ | |
551 | if (state->mode == GZ_READ) { | |
552 | state->eof = 0; | |
553 | state->past = 0; | |
554 | } | |
555 | gz_error(state, Z_OK, NULL); | |
556 | } | |
557 | ||
558 | /* Create an error message in allocated memory and set state->err and | |
559 | state->msg accordingly. Free any previous error message already there. Do | |
560 | not try to free or allocate space if the error is Z_MEM_ERROR (out of | |
561 | memory). Simply save the error message as a static string. If there is an | |
562 | allocation failure constructing the error message, then convert the error to | |
563 | out of memory. */ | |
564 | void ZLIB_INTERNAL gz_error(state, err, msg) | |
565 | gz_statep state; | |
566 | int err; | |
567 | const char *msg; | |
568 | { | |
569 | /* free previously allocated message and clear */ | |
570 | if (state->msg != NULL) { | |
571 | if (state->err != Z_MEM_ERROR) | |
572 | free(state->msg); | |
573 | state->msg = NULL; | |
574 | } | |
575 | ||
576 | /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */ | |
577 | if (err != Z_OK && err != Z_BUF_ERROR) | |
578 | state->x.have = 0; | |
579 | ||
580 | /* set error code, and if no message, then done */ | |
581 | state->err = err; | |
582 | if (msg == NULL) | |
583 | return; | |
584 | ||
585 | /* for an out of memory error, save as static string */ | |
586 | if (err == Z_MEM_ERROR) { | |
587 | state->msg = (char *)msg; | |
588 | return; | |
589 | } | |
590 | ||
591 | /* construct error message with path */ | |
592 | if ((state->msg = malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) { | |
593 | state->err = Z_MEM_ERROR; | |
594 | state->msg = (char *)"out of memory"; | |
595 | return; | |
596 | } | |
597 | strcpy(state->msg, state->path); | |
598 | strcat(state->msg, ": "); | |
599 | strcat(state->msg, msg); | |
600 | return; | |
601 | } | |
602 | ||
603 | #ifndef INT_MAX | |
604 | /* portably return maximum value for an int (when limits.h presumed not | |
605 | available) -- we need to do this to cover cases where 2's complement not | |
606 | used, since C standard permits 1's complement and sign-bit representations, | |
607 | otherwise we could just use ((unsigned)-1) >> 1 */ | |
608 | unsigned ZLIB_INTERNAL gz_intmax() | |
609 | { | |
610 | unsigned p, q; | |
611 | ||
612 | p = 1; | |
613 | do { | |
614 | q = p; | |
615 | p <<= 1; | |
616 | p++; | |
617 | } while (p > q); | |
618 | return q >> 1; | |
619 | } | |
620 | #endif |