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1 | /* gzlib.c -- zlib functions common to reading and writing gzip files |
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2 | * Copyright (C) 2004-2019 Mark Adler |
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3 | * For conditions of distribution and use, see copyright notice in zlib.h |
4 | */ |
5 | |
6 | #include "gzguts.h" |
7 | |
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8 | #if defined(_WIN32) && !defined(__BORLANDC__) |
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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. */ |
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33 | char ZLIB_INTERNAL *gz_strwinerror(error) |
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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 | } |
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84 | else /* for writing ... */ |
85 | state->reset = 0; /* no deflateReset pending */ |
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86 | state->seek = 0; /* no seek request pending */ |
87 | gz_error(state, Z_OK, NULL); /* clear error */ |
88 | state->x.pos = 0; /* no uncompressed data yet */ |
89 | state->strm.avail_in = 0; /* no input data yet */ |
90 | } |
91 | |
92 | /* Open a gzip file either by name or file descriptor. */ |
93 | local gzFile gz_open(path, fd, mode) |
94 | const void *path; |
95 | int fd; |
96 | const char *mode; |
97 | { |
98 | gz_statep state; |
99 | z_size_t len; |
100 | int oflag; |
101 | #ifdef O_CLOEXEC |
102 | int cloexec = 0; |
103 | #endif |
104 | #ifdef O_EXCL |
105 | int exclusive = 0; |
106 | #endif |
107 | |
108 | /* check input */ |
109 | if (path == NULL) |
110 | return NULL; |
111 | |
112 | /* allocate gzFile structure to return */ |
113 | state = (gz_statep)malloc(sizeof(gz_state)); |
114 | if (state == NULL) |
115 | return NULL; |
116 | state->size = 0; /* no buffers allocated yet */ |
117 | state->want = GZBUFSIZE; /* requested buffer size */ |
118 | state->msg = NULL; /* no error message yet */ |
119 | |
120 | /* interpret mode */ |
121 | state->mode = GZ_NONE; |
122 | state->level = Z_DEFAULT_COMPRESSION; |
123 | state->strategy = Z_DEFAULT_STRATEGY; |
124 | state->direct = 0; |
125 | while (*mode) { |
126 | if (*mode >= '0' && *mode <= '9') |
127 | state->level = *mode - '0'; |
128 | else |
129 | switch (*mode) { |
130 | case 'r': |
131 | state->mode = GZ_READ; |
132 | break; |
133 | #ifndef NO_GZCOMPRESS |
134 | case 'w': |
135 | state->mode = GZ_WRITE; |
136 | break; |
137 | case 'a': |
138 | state->mode = GZ_APPEND; |
139 | break; |
140 | #endif |
141 | case '+': /* can't read and write at the same time */ |
142 | free(state); |
143 | return NULL; |
144 | case 'b': /* ignore -- will request binary anyway */ |
145 | break; |
146 | #ifdef O_CLOEXEC |
147 | case 'e': |
148 | cloexec = 1; |
149 | break; |
150 | #endif |
151 | #ifdef O_EXCL |
152 | case 'x': |
153 | exclusive = 1; |
154 | break; |
155 | #endif |
156 | case 'f': |
157 | state->strategy = Z_FILTERED; |
158 | break; |
159 | case 'h': |
160 | state->strategy = Z_HUFFMAN_ONLY; |
161 | break; |
162 | case 'R': |
163 | state->strategy = Z_RLE; |
164 | break; |
165 | case 'F': |
166 | state->strategy = Z_FIXED; |
167 | break; |
168 | case 'T': |
169 | state->direct = 1; |
170 | break; |
171 | default: /* could consider as an error, but just ignore */ |
172 | ; |
173 | } |
174 | mode++; |
175 | } |
176 | |
177 | /* must provide an "r", "w", or "a" */ |
178 | if (state->mode == GZ_NONE) { |
179 | free(state); |
180 | return NULL; |
181 | } |
182 | |
183 | /* can't force transparent read */ |
184 | if (state->mode == GZ_READ) { |
185 | if (state->direct) { |
186 | free(state); |
187 | return NULL; |
188 | } |
189 | state->direct = 1; /* for empty file */ |
190 | } |
191 | |
192 | /* save the path name for error messages */ |
193 | #ifdef WIDECHAR |
194 | if (fd == -2) { |
195 | len = wcstombs(NULL, path, 0); |
196 | if (len == (z_size_t)-1) |
197 | len = 0; |
198 | } |
199 | else |
200 | #endif |
201 | len = strlen((const char *)path); |
202 | state->path = (char *)malloc(len + 1); |
203 | if (state->path == NULL) { |
204 | free(state); |
205 | return NULL; |
206 | } |
207 | #ifdef WIDECHAR |
208 | if (fd == -2) |
209 | if (len) |
210 | wcstombs(state->path, path, len + 1); |
211 | else |
212 | *(state->path) = 0; |
213 | else |
214 | #endif |
215 | #if !defined(NO_snprintf) && !defined(NO_vsnprintf) |
216 | (void)snprintf(state->path, len + 1, "%s", (const char *)path); |
217 | #else |
218 | strcpy(state->path, path); |
219 | #endif |
220 | |
221 | /* compute the flags for open() */ |
222 | oflag = |
223 | #ifdef O_LARGEFILE |
224 | O_LARGEFILE | |
225 | #endif |
226 | #ifdef O_BINARY |
227 | O_BINARY | |
228 | #endif |
229 | #ifdef O_CLOEXEC |
230 | (cloexec ? O_CLOEXEC : 0) | |
231 | #endif |
232 | (state->mode == GZ_READ ? |
233 | O_RDONLY : |
234 | (O_WRONLY | O_CREAT | |
235 | #ifdef O_EXCL |
236 | (exclusive ? O_EXCL : 0) | |
237 | #endif |
238 | (state->mode == GZ_WRITE ? |
239 | O_TRUNC : |
240 | O_APPEND))); |
241 | |
242 | /* open the file with the appropriate flags (or just use fd) */ |
243 | state->fd = fd > -1 ? fd : ( |
244 | #ifdef WIDECHAR |
245 | fd == -2 ? _wopen(path, oflag, 0666) : |
246 | #endif |
247 | open((const char *)path, oflag, 0666)); |
248 | if (state->fd == -1) { |
249 | free(state->path); |
250 | free(state); |
251 | return NULL; |
252 | } |
253 | if (state->mode == GZ_APPEND) { |
254 | LSEEK(state->fd, 0, SEEK_END); /* so gzoffset() is correct */ |
255 | state->mode = GZ_WRITE; /* simplify later checks */ |
256 | } |
257 | |
258 | /* save the current position for rewinding (only if reading) */ |
259 | if (state->mode == GZ_READ) { |
260 | state->start = LSEEK(state->fd, 0, SEEK_CUR); |
261 | if (state->start == -1) state->start = 0; |
262 | } |
263 | |
264 | /* initialize stream */ |
265 | gz_reset(state); |
266 | |
267 | /* return stream */ |
268 | return (gzFile)state; |
269 | } |
270 | |
271 | /* -- see zlib.h -- */ |
272 | gzFile ZEXPORT gzopen(path, mode) |
273 | const char *path; |
274 | const char *mode; |
275 | { |
276 | return gz_open(path, -1, mode); |
277 | } |
278 | |
279 | /* -- see zlib.h -- */ |
280 | gzFile ZEXPORT gzopen64(path, mode) |
281 | const char *path; |
282 | const char *mode; |
283 | { |
284 | return gz_open(path, -1, mode); |
285 | } |
286 | |
287 | /* -- see zlib.h -- */ |
288 | gzFile ZEXPORT gzdopen(fd, mode) |
289 | int fd; |
290 | const char *mode; |
291 | { |
292 | char *path; /* identifier for error messages */ |
293 | gzFile gz; |
294 | |
295 | if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL) |
296 | return NULL; |
297 | #if !defined(NO_snprintf) && !defined(NO_vsnprintf) |
298 | (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd); |
299 | #else |
300 | sprintf(path, "<fd:%d>", fd); /* for debugging */ |
301 | #endif |
302 | gz = gz_open(path, fd, mode); |
303 | free(path); |
304 | return gz; |
305 | } |
306 | |
307 | /* -- see zlib.h -- */ |
308 | #ifdef WIDECHAR |
309 | gzFile ZEXPORT gzopen_w(path, mode) |
310 | const wchar_t *path; |
311 | const char *mode; |
312 | { |
313 | return gz_open(path, -2, mode); |
314 | } |
315 | #endif |
316 | |
317 | /* -- see zlib.h -- */ |
318 | int ZEXPORT gzbuffer(file, size) |
319 | gzFile file; |
320 | unsigned size; |
321 | { |
322 | gz_statep state; |
323 | |
324 | /* get internal structure and check integrity */ |
325 | if (file == NULL) |
326 | return -1; |
327 | state = (gz_statep)file; |
328 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
329 | return -1; |
330 | |
331 | /* make sure we haven't already allocated memory */ |
332 | if (state->size != 0) |
333 | return -1; |
334 | |
335 | /* check and set requested size */ |
336 | if ((size << 1) < size) |
337 | return -1; /* need to be able to double it */ |
338 | if (size < 2) |
339 | size = 2; /* need two bytes to check magic header */ |
340 | state->want = size; |
341 | return 0; |
342 | } |
343 | |
344 | /* -- see zlib.h -- */ |
345 | int ZEXPORT gzrewind(file) |
346 | gzFile file; |
347 | { |
348 | gz_statep state; |
349 | |
350 | /* get internal structure */ |
351 | if (file == NULL) |
352 | return -1; |
353 | state = (gz_statep)file; |
354 | |
355 | /* check that we're reading and that there's no error */ |
356 | if (state->mode != GZ_READ || |
357 | (state->err != Z_OK && state->err != Z_BUF_ERROR)) |
358 | return -1; |
359 | |
360 | /* back up and start over */ |
361 | if (LSEEK(state->fd, state->start, SEEK_SET) == -1) |
362 | return -1; |
363 | gz_reset(state); |
364 | return 0; |
365 | } |
366 | |
367 | /* -- see zlib.h -- */ |
368 | z_off64_t ZEXPORT gzseek64(file, offset, whence) |
369 | gzFile file; |
370 | z_off64_t offset; |
371 | int whence; |
372 | { |
373 | unsigned n; |
374 | z_off64_t ret; |
375 | gz_statep state; |
376 | |
377 | /* get internal structure and check integrity */ |
378 | if (file == NULL) |
379 | return -1; |
380 | state = (gz_statep)file; |
381 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
382 | return -1; |
383 | |
384 | /* check that there's no error */ |
385 | if (state->err != Z_OK && state->err != Z_BUF_ERROR) |
386 | return -1; |
387 | |
388 | /* can only seek from start or relative to current position */ |
389 | if (whence != SEEK_SET && whence != SEEK_CUR) |
390 | return -1; |
391 | |
392 | /* normalize offset to a SEEK_CUR specification */ |
393 | if (whence == SEEK_SET) |
394 | offset -= state->x.pos; |
395 | else if (state->seek) |
396 | offset += state->skip; |
397 | state->seek = 0; |
398 | |
399 | /* if within raw area while reading, just go there */ |
400 | if (state->mode == GZ_READ && state->how == COPY && |
401 | state->x.pos + offset >= 0) { |
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402 | ret = LSEEK(state->fd, offset - (z_off64_t)state->x.have, SEEK_CUR); |
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403 | if (ret == -1) |
404 | return -1; |
405 | state->x.have = 0; |
406 | state->eof = 0; |
407 | state->past = 0; |
408 | state->seek = 0; |
409 | gz_error(state, Z_OK, NULL); |
410 | state->strm.avail_in = 0; |
411 | state->x.pos += offset; |
412 | return state->x.pos; |
413 | } |
414 | |
415 | /* calculate skip amount, rewinding if needed for back seek when reading */ |
416 | if (offset < 0) { |
417 | if (state->mode != GZ_READ) /* writing -- can't go backwards */ |
418 | return -1; |
419 | offset += state->x.pos; |
420 | if (offset < 0) /* before start of file! */ |
421 | return -1; |
422 | if (gzrewind(file) == -1) /* rewind, then skip to offset */ |
423 | return -1; |
424 | } |
425 | |
426 | /* if reading, skip what's in output buffer (one less gzgetc() check) */ |
427 | if (state->mode == GZ_READ) { |
428 | n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ? |
429 | (unsigned)offset : state->x.have; |
430 | state->x.have -= n; |
431 | state->x.next += n; |
432 | state->x.pos += n; |
433 | offset -= n; |
434 | } |
435 | |
436 | /* request skip (if not zero) */ |
437 | if (offset) { |
438 | state->seek = 1; |
439 | state->skip = offset; |
440 | } |
441 | return state->x.pos + offset; |
442 | } |
443 | |
444 | /* -- see zlib.h -- */ |
445 | z_off_t ZEXPORT gzseek(file, offset, whence) |
446 | gzFile file; |
447 | z_off_t offset; |
448 | int whence; |
449 | { |
450 | z_off64_t ret; |
451 | |
452 | ret = gzseek64(file, (z_off64_t)offset, whence); |
453 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
454 | } |
455 | |
456 | /* -- see zlib.h -- */ |
457 | z_off64_t ZEXPORT gztell64(file) |
458 | gzFile file; |
459 | { |
460 | gz_statep state; |
461 | |
462 | /* get internal structure and check integrity */ |
463 | if (file == NULL) |
464 | return -1; |
465 | state = (gz_statep)file; |
466 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
467 | return -1; |
468 | |
469 | /* return position */ |
470 | return state->x.pos + (state->seek ? state->skip : 0); |
471 | } |
472 | |
473 | /* -- see zlib.h -- */ |
474 | z_off_t ZEXPORT gztell(file) |
475 | gzFile file; |
476 | { |
477 | z_off64_t ret; |
478 | |
479 | ret = gztell64(file); |
480 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
481 | } |
482 | |
483 | /* -- see zlib.h -- */ |
484 | z_off64_t ZEXPORT gzoffset64(file) |
485 | gzFile file; |
486 | { |
487 | z_off64_t offset; |
488 | gz_statep state; |
489 | |
490 | /* get internal structure and check integrity */ |
491 | if (file == NULL) |
492 | return -1; |
493 | state = (gz_statep)file; |
494 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
495 | return -1; |
496 | |
497 | /* compute and return effective offset in file */ |
498 | offset = LSEEK(state->fd, 0, SEEK_CUR); |
499 | if (offset == -1) |
500 | return -1; |
501 | if (state->mode == GZ_READ) /* reading */ |
502 | offset -= state->strm.avail_in; /* don't count buffered input */ |
503 | return offset; |
504 | } |
505 | |
506 | /* -- see zlib.h -- */ |
507 | z_off_t ZEXPORT gzoffset(file) |
508 | gzFile file; |
509 | { |
510 | z_off64_t ret; |
511 | |
512 | ret = gzoffset64(file); |
513 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
514 | } |
515 | |
516 | /* -- see zlib.h -- */ |
517 | int ZEXPORT gzeof(file) |
518 | gzFile file; |
519 | { |
520 | gz_statep state; |
521 | |
522 | /* get internal structure and check integrity */ |
523 | if (file == NULL) |
524 | return 0; |
525 | state = (gz_statep)file; |
526 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
527 | return 0; |
528 | |
529 | /* return end-of-file state */ |
530 | return state->mode == GZ_READ ? state->past : 0; |
531 | } |
532 | |
533 | /* -- see zlib.h -- */ |
534 | const char * ZEXPORT gzerror(file, errnum) |
535 | gzFile file; |
536 | int *errnum; |
537 | { |
538 | gz_statep state; |
539 | |
540 | /* get internal structure and check integrity */ |
541 | if (file == NULL) |
542 | return NULL; |
543 | state = (gz_statep)file; |
544 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
545 | return NULL; |
546 | |
547 | /* return error information */ |
548 | if (errnum != NULL) |
549 | *errnum = state->err; |
550 | return state->err == Z_MEM_ERROR ? "out of memory" : |
551 | (state->msg == NULL ? "" : state->msg); |
552 | } |
553 | |
554 | /* -- see zlib.h -- */ |
555 | void ZEXPORT gzclearerr(file) |
556 | gzFile file; |
557 | { |
558 | gz_statep state; |
559 | |
560 | /* get internal structure and check integrity */ |
561 | if (file == NULL) |
562 | return; |
563 | state = (gz_statep)file; |
564 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
565 | return; |
566 | |
567 | /* clear error and end-of-file */ |
568 | if (state->mode == GZ_READ) { |
569 | state->eof = 0; |
570 | state->past = 0; |
571 | } |
572 | gz_error(state, Z_OK, NULL); |
573 | } |
574 | |
575 | /* Create an error message in allocated memory and set state->err and |
576 | state->msg accordingly. Free any previous error message already there. Do |
577 | not try to free or allocate space if the error is Z_MEM_ERROR (out of |
578 | memory). Simply save the error message as a static string. If there is an |
579 | allocation failure constructing the error message, then convert the error to |
580 | out of memory. */ |
581 | void ZLIB_INTERNAL gz_error(state, err, msg) |
582 | gz_statep state; |
583 | int err; |
584 | const char *msg; |
585 | { |
586 | /* free previously allocated message and clear */ |
587 | if (state->msg != NULL) { |
588 | if (state->err != Z_MEM_ERROR) |
589 | free(state->msg); |
590 | state->msg = NULL; |
591 | } |
592 | |
593 | /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */ |
594 | if (err != Z_OK && err != Z_BUF_ERROR) |
595 | state->x.have = 0; |
596 | |
597 | /* set error code, and if no message, then done */ |
598 | state->err = err; |
599 | if (msg == NULL) |
600 | return; |
601 | |
602 | /* for an out of memory error, return literal string when requested */ |
603 | if (err == Z_MEM_ERROR) |
604 | return; |
605 | |
606 | /* construct error message with path */ |
607 | if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) == |
608 | NULL) { |
609 | state->err = Z_MEM_ERROR; |
610 | return; |
611 | } |
612 | #if !defined(NO_snprintf) && !defined(NO_vsnprintf) |
613 | (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3, |
614 | "%s%s%s", state->path, ": ", msg); |
615 | #else |
616 | strcpy(state->msg, state->path); |
617 | strcat(state->msg, ": "); |
618 | strcat(state->msg, msg); |
619 | #endif |
620 | } |
621 | |
622 | #ifndef INT_MAX |
623 | /* portably return maximum value for an int (when limits.h presumed not |
624 | available) -- we need to do this to cover cases where 2's complement not |
625 | used, since C standard permits 1's complement and sign-bit representations, |
626 | otherwise we could just use ((unsigned)-1) >> 1 */ |
627 | unsigned ZLIB_INTERNAL gz_intmax() |
628 | { |
629 | unsigned p, q; |
630 | |
631 | p = 1; |
632 | do { |
633 | q = p; |
634 | p <<= 1; |
635 | p++; |
636 | } while (p > q); |
637 | return q >> 1; |
638 | } |
639 | #endif |