Line data Source code
1 : /* gzlib.c -- zlib functions common to reading and writing gzip files
2 : * Copyright (C) 2004-2017 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__) && !defined(__MINGW32__)
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 0 : local void gz_reset(state)
76 : gz_statep state;
77 : {
78 0 : state->x.have = 0; /* no output data available */
79 0 : if (state->mode == GZ_READ) { /* for reading ... */
80 0 : state->eof = 0; /* not at end of file */
81 0 : state->past = 0; /* have not read past end yet */
82 0 : state->how = LOOK; /* look for gzip header */
83 : }
84 0 : state->seek = 0; /* no seek request pending */
85 0 : gz_error(state, Z_OK, NULL); /* clear error */
86 0 : state->x.pos = 0; /* no uncompressed data yet */
87 0 : state->strm.avail_in = 0; /* no input data yet */
88 0 : }
89 :
90 : /* Open a gzip file either by name or file descriptor. */
91 0 : local gzFile gz_open(path, fd, mode)
92 : const void *path;
93 : int fd;
94 : const char *mode;
95 : {
96 : gz_statep state;
97 : z_size_t len;
98 : int oflag;
99 : #ifdef O_CLOEXEC
100 0 : int cloexec = 0;
101 : #endif
102 : #ifdef O_EXCL
103 0 : int exclusive = 0;
104 : #endif
105 :
106 : /* check input */
107 0 : if (path == NULL)
108 0 : return NULL;
109 :
110 : /* allocate gzFile structure to return */
111 0 : state = (gz_statep)malloc(sizeof(gz_state));
112 0 : if (state == NULL)
113 0 : return NULL;
114 0 : state->size = 0; /* no buffers allocated yet */
115 0 : state->want = GZBUFSIZE; /* requested buffer size */
116 0 : state->msg = NULL; /* no error message yet */
117 :
118 : /* interpret mode */
119 0 : state->mode = GZ_NONE;
120 0 : state->level = Z_DEFAULT_COMPRESSION;
121 0 : state->strategy = Z_DEFAULT_STRATEGY;
122 0 : state->direct = 0;
123 0 : while (*mode) {
124 0 : if (*mode >= '0' && *mode <= '9')
125 0 : state->level = *mode - '0';
126 : else
127 0 : switch (*mode) {
128 : case 'r':
129 0 : state->mode = GZ_READ;
130 0 : break;
131 : #ifndef NO_GZCOMPRESS
132 : case 'w':
133 0 : state->mode = GZ_WRITE;
134 0 : break;
135 : case 'a':
136 0 : state->mode = GZ_APPEND;
137 0 : break;
138 : #endif
139 : case '+': /* can't read and write at the same time */
140 0 : free(state);
141 0 : return NULL;
142 : case 'b': /* ignore -- will request binary anyway */
143 0 : break;
144 : #ifdef O_CLOEXEC
145 : case 'e':
146 0 : cloexec = 1;
147 0 : break;
148 : #endif
149 : #ifdef O_EXCL
150 : case 'x':
151 0 : exclusive = 1;
152 0 : break;
153 : #endif
154 : case 'f':
155 0 : state->strategy = Z_FILTERED;
156 0 : break;
157 : case 'h':
158 0 : state->strategy = Z_HUFFMAN_ONLY;
159 0 : break;
160 : case 'R':
161 0 : state->strategy = Z_RLE;
162 0 : break;
163 : case 'F':
164 0 : state->strategy = Z_FIXED;
165 0 : break;
166 : case 'T':
167 0 : state->direct = 1;
168 0 : break;
169 : default: /* could consider as an error, but just ignore */
170 : ;
171 : }
172 0 : mode++;
173 : }
174 :
175 : /* must provide an "r", "w", or "a" */
176 0 : if (state->mode == GZ_NONE) {
177 0 : free(state);
178 0 : return NULL;
179 : }
180 :
181 : /* can't force transparent read */
182 0 : if (state->mode == GZ_READ) {
183 0 : if (state->direct) {
184 0 : free(state);
185 0 : return NULL;
186 : }
187 0 : state->direct = 1; /* for empty file */
188 : }
189 :
190 : /* save the path name for error messages */
191 : #ifdef WIDECHAR
192 : if (fd == -2) {
193 : len = wcstombs(NULL, path, 0);
194 : if (len == (z_size_t)-1)
195 : len = 0;
196 : }
197 : else
198 : #endif
199 0 : len = strlen((const char *)path);
200 0 : state->path = (char *)malloc(len + 1);
201 0 : if (state->path == NULL) {
202 0 : free(state);
203 0 : return NULL;
204 : }
205 : #ifdef WIDECHAR
206 : if (fd == -2)
207 : if (len)
208 : wcstombs(state->path, path, len + 1);
209 : else
210 : *(state->path) = 0;
211 : else
212 : #endif
213 : #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
214 0 : (void)snprintf(state->path, len + 1, "%s", (const char *)path);
215 : #else
216 : strcpy(state->path, path);
217 : #endif
218 :
219 : /* compute the flags for open() */
220 0 : oflag =
221 : #ifdef O_LARGEFILE
222 : O_LARGEFILE |
223 : #endif
224 : #ifdef O_BINARY
225 : O_BINARY |
226 : #endif
227 : #ifdef O_CLOEXEC
228 0 : (cloexec ? O_CLOEXEC : 0) |
229 : #endif
230 0 : (state->mode == GZ_READ ?
231 0 : O_RDONLY :
232 0 : (O_WRONLY | O_CREAT |
233 : #ifdef O_EXCL
234 : (exclusive ? O_EXCL : 0) |
235 : #endif
236 0 : (state->mode == GZ_WRITE ?
237 0 : O_TRUNC :
238 : O_APPEND)));
239 :
240 : /* open the file with the appropriate flags (or just use fd) */
241 0 : state->fd = fd > -1 ? fd : (
242 : #ifdef WIDECHAR
243 : fd == -2 ? _wopen(path, oflag, 0666) :
244 : #endif
245 : open((const char *)path, oflag, 0666));
246 0 : if (state->fd == -1) {
247 0 : free(state->path);
248 0 : free(state);
249 0 : return NULL;
250 : }
251 0 : if (state->mode == GZ_APPEND) {
252 0 : LSEEK(state->fd, 0, SEEK_END); /* so gzoffset() is correct */
253 0 : state->mode = GZ_WRITE; /* simplify later checks */
254 : }
255 :
256 : /* save the current position for rewinding (only if reading) */
257 0 : if (state->mode == GZ_READ) {
258 0 : state->start = LSEEK(state->fd, 0, SEEK_CUR);
259 0 : if (state->start == -1) state->start = 0;
260 : }
261 :
262 : /* initialize stream */
263 0 : gz_reset(state);
264 :
265 : /* return stream */
266 0 : return (gzFile)state;
267 : }
268 :
269 : /* -- see zlib.h -- */
270 0 : gzFile ZEXPORT gzopen(path, mode)
271 : const char *path;
272 : const char *mode;
273 : {
274 0 : return gz_open(path, -1, mode);
275 : }
276 :
277 : /* -- see zlib.h -- */
278 0 : gzFile ZEXPORT gzopen64(path, mode)
279 : const char *path;
280 : const char *mode;
281 : {
282 0 : return gz_open(path, -1, mode);
283 : }
284 :
285 : /* -- see zlib.h -- */
286 0 : gzFile ZEXPORT gzdopen(fd, mode)
287 : int fd;
288 : const char *mode;
289 : {
290 : char *path; /* identifier for error messages */
291 : gzFile gz;
292 :
293 0 : if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
294 0 : return NULL;
295 : #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
296 0 : (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd);
297 : #else
298 : sprintf(path, "<fd:%d>", fd); /* for debugging */
299 : #endif
300 0 : gz = gz_open(path, fd, mode);
301 0 : free(path);
302 0 : return gz;
303 : }
304 :
305 : /* -- see zlib.h -- */
306 : #ifdef WIDECHAR
307 : gzFile ZEXPORT gzopen_w(path, mode)
308 : const wchar_t *path;
309 : const char *mode;
310 : {
311 : return gz_open(path, -2, mode);
312 : }
313 : #endif
314 :
315 : /* -- see zlib.h -- */
316 0 : int ZEXPORT gzbuffer(file, size)
317 : gzFile file;
318 : unsigned size;
319 : {
320 : gz_statep state;
321 :
322 : /* get internal structure and check integrity */
323 0 : if (file == NULL)
324 0 : return -1;
325 0 : state = (gz_statep)file;
326 0 : if (state->mode != GZ_READ && state->mode != GZ_WRITE)
327 0 : return -1;
328 :
329 : /* make sure we haven't already allocated memory */
330 0 : if (state->size != 0)
331 0 : return -1;
332 :
333 : /* check and set requested size */
334 0 : if ((size << 1) < size)
335 0 : return -1; /* need to be able to double it */
336 0 : if (size < 2)
337 0 : size = 2; /* need two bytes to check magic header */
338 0 : state->want = size;
339 0 : return 0;
340 : }
341 :
342 : /* -- see zlib.h -- */
343 0 : int ZEXPORT gzrewind(file)
344 : gzFile file;
345 : {
346 : gz_statep state;
347 :
348 : /* get internal structure */
349 0 : if (file == NULL)
350 0 : return -1;
351 0 : state = (gz_statep)file;
352 :
353 : /* check that we're reading and that there's no error */
354 0 : if (state->mode != GZ_READ ||
355 0 : (state->err != Z_OK && state->err != Z_BUF_ERROR))
356 0 : return -1;
357 :
358 : /* back up and start over */
359 0 : if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
360 0 : return -1;
361 0 : gz_reset(state);
362 0 : return 0;
363 : }
364 :
365 : /* -- see zlib.h -- */
366 0 : z_off64_t ZEXPORT gzseek64(file, offset, whence)
367 : gzFile file;
368 : z_off64_t offset;
369 : int whence;
370 : {
371 : unsigned n;
372 : z_off64_t ret;
373 : gz_statep state;
374 :
375 : /* get internal structure and check integrity */
376 0 : if (file == NULL)
377 0 : return -1;
378 0 : state = (gz_statep)file;
379 0 : if (state->mode != GZ_READ && state->mode != GZ_WRITE)
380 0 : return -1;
381 :
382 : /* check that there's no error */
383 0 : if (state->err != Z_OK && state->err != Z_BUF_ERROR)
384 0 : return -1;
385 :
386 : /* can only seek from start or relative to current position */
387 0 : if (whence != SEEK_SET && whence != SEEK_CUR)
388 0 : return -1;
389 :
390 : /* normalize offset to a SEEK_CUR specification */
391 0 : if (whence == SEEK_SET)
392 0 : offset -= state->x.pos;
393 0 : else if (state->seek)
394 0 : offset += state->skip;
395 0 : state->seek = 0;
396 :
397 : /* if within raw area while reading, just go there */
398 0 : if (state->mode == GZ_READ && state->how == COPY &&
399 0 : state->x.pos + offset >= 0) {
400 0 : ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
401 0 : if (ret == -1)
402 0 : return -1;
403 0 : state->x.have = 0;
404 0 : state->eof = 0;
405 0 : state->past = 0;
406 0 : state->seek = 0;
407 0 : gz_error(state, Z_OK, NULL);
408 0 : state->strm.avail_in = 0;
409 0 : state->x.pos += offset;
410 0 : return state->x.pos;
411 : }
412 :
413 : /* calculate skip amount, rewinding if needed for back seek when reading */
414 0 : if (offset < 0) {
415 0 : if (state->mode != GZ_READ) /* writing -- can't go backwards */
416 0 : return -1;
417 0 : offset += state->x.pos;
418 0 : if (offset < 0) /* before start of file! */
419 0 : return -1;
420 0 : if (gzrewind(file) == -1) /* rewind, then skip to offset */
421 0 : return -1;
422 : }
423 :
424 : /* if reading, skip what's in output buffer (one less gzgetc() check) */
425 0 : if (state->mode == GZ_READ) {
426 0 : n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ?
427 0 : (unsigned)offset : state->x.have;
428 0 : state->x.have -= n;
429 0 : state->x.next += n;
430 0 : state->x.pos += n;
431 0 : offset -= n;
432 : }
433 :
434 : /* request skip (if not zero) */
435 0 : if (offset) {
436 0 : state->seek = 1;
437 0 : state->skip = offset;
438 : }
439 0 : return state->x.pos + offset;
440 : }
441 :
442 : /* -- see zlib.h -- */
443 0 : z_off_t ZEXPORT gzseek(file, offset, whence)
444 : gzFile file;
445 : z_off_t offset;
446 : int whence;
447 : {
448 : z_off64_t ret;
449 :
450 0 : ret = gzseek64(file, (z_off64_t)offset, whence);
451 0 : return ret == (z_off_t)ret ? (z_off_t)ret : -1;
452 : }
453 :
454 : /* -- see zlib.h -- */
455 0 : z_off64_t ZEXPORT gztell64(file)
456 : gzFile file;
457 : {
458 : gz_statep state;
459 :
460 : /* get internal structure and check integrity */
461 0 : if (file == NULL)
462 0 : return -1;
463 0 : state = (gz_statep)file;
464 0 : if (state->mode != GZ_READ && state->mode != GZ_WRITE)
465 0 : return -1;
466 :
467 : /* return position */
468 0 : return state->x.pos + (state->seek ? state->skip : 0);
469 : }
470 :
471 : /* -- see zlib.h -- */
472 0 : z_off_t ZEXPORT gztell(file)
473 : gzFile file;
474 : {
475 : z_off64_t ret;
476 :
477 0 : ret = gztell64(file);
478 0 : return ret == (z_off_t)ret ? (z_off_t)ret : -1;
479 : }
480 :
481 : /* -- see zlib.h -- */
482 0 : z_off64_t ZEXPORT gzoffset64(file)
483 : gzFile file;
484 : {
485 : z_off64_t offset;
486 : gz_statep state;
487 :
488 : /* get internal structure and check integrity */
489 0 : if (file == NULL)
490 0 : return -1;
491 0 : state = (gz_statep)file;
492 0 : if (state->mode != GZ_READ && state->mode != GZ_WRITE)
493 0 : return -1;
494 :
495 : /* compute and return effective offset in file */
496 0 : offset = LSEEK(state->fd, 0, SEEK_CUR);
497 0 : if (offset == -1)
498 0 : return -1;
499 0 : if (state->mode == GZ_READ) /* reading */
500 0 : offset -= state->strm.avail_in; /* don't count buffered input */
501 0 : return offset;
502 : }
503 :
504 : /* -- see zlib.h -- */
505 0 : z_off_t ZEXPORT gzoffset(file)
506 : gzFile file;
507 : {
508 : z_off64_t ret;
509 :
510 0 : ret = gzoffset64(file);
511 0 : return ret == (z_off_t)ret ? (z_off_t)ret : -1;
512 : }
513 :
514 : /* -- see zlib.h -- */
515 0 : int ZEXPORT gzeof(file)
516 : gzFile file;
517 : {
518 : gz_statep state;
519 :
520 : /* get internal structure and check integrity */
521 0 : if (file == NULL)
522 0 : return 0;
523 0 : state = (gz_statep)file;
524 0 : if (state->mode != GZ_READ && state->mode != GZ_WRITE)
525 0 : return 0;
526 :
527 : /* return end-of-file state */
528 0 : return state->mode == GZ_READ ? state->past : 0;
529 : }
530 :
531 : /* -- see zlib.h -- */
532 0 : const char * ZEXPORT gzerror(file, errnum)
533 : gzFile file;
534 : int *errnum;
535 : {
536 : gz_statep state;
537 :
538 : /* get internal structure and check integrity */
539 0 : if (file == NULL)
540 0 : return NULL;
541 0 : state = (gz_statep)file;
542 0 : if (state->mode != GZ_READ && state->mode != GZ_WRITE)
543 0 : return NULL;
544 :
545 : /* return error information */
546 0 : if (errnum != NULL)
547 0 : *errnum = state->err;
548 0 : return state->err == Z_MEM_ERROR ? "out of memory" :
549 0 : (state->msg == NULL ? "" : state->msg);
550 : }
551 :
552 : /* -- see zlib.h -- */
553 0 : void ZEXPORT gzclearerr(file)
554 : gzFile file;
555 : {
556 : gz_statep state;
557 :
558 : /* get internal structure and check integrity */
559 0 : if (file == NULL)
560 0 : return;
561 0 : state = (gz_statep)file;
562 0 : if (state->mode != GZ_READ && state->mode != GZ_WRITE)
563 0 : return;
564 :
565 : /* clear error and end-of-file */
566 0 : if (state->mode == GZ_READ) {
567 0 : state->eof = 0;
568 0 : state->past = 0;
569 : }
570 0 : gz_error(state, Z_OK, NULL);
571 : }
572 :
573 : /* Create an error message in allocated memory and set state->err and
574 : state->msg accordingly. Free any previous error message already there. Do
575 : not try to free or allocate space if the error is Z_MEM_ERROR (out of
576 : memory). Simply save the error message as a static string. If there is an
577 : allocation failure constructing the error message, then convert the error to
578 : out of memory. */
579 0 : void ZLIB_INTERNAL gz_error(state, err, msg)
580 : gz_statep state;
581 : int err;
582 : const char *msg;
583 : {
584 : /* free previously allocated message and clear */
585 0 : if (state->msg != NULL) {
586 0 : if (state->err != Z_MEM_ERROR)
587 0 : free(state->msg);
588 0 : state->msg = NULL;
589 : }
590 :
591 : /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
592 0 : if (err != Z_OK && err != Z_BUF_ERROR)
593 0 : state->x.have = 0;
594 :
595 : /* set error code, and if no message, then done */
596 0 : state->err = err;
597 0 : if (msg == NULL)
598 0 : return;
599 :
600 : /* for an out of memory error, return literal string when requested */
601 0 : if (err == Z_MEM_ERROR)
602 0 : return;
603 :
604 : /* construct error message with path */
605 0 : if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
606 : NULL) {
607 0 : state->err = Z_MEM_ERROR;
608 0 : return;
609 : }
610 : #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
611 0 : (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
612 : "%s%s%s", state->path, ": ", msg);
613 : #else
614 : strcpy(state->msg, state->path);
615 : strcat(state->msg, ": ");
616 : strcat(state->msg, msg);
617 : #endif
618 : }
619 :
620 : #ifndef INT_MAX
621 : /* portably return maximum value for an int (when limits.h presumed not
622 : available) -- we need to do this to cover cases where 2's complement not
623 : used, since C standard permits 1's complement and sign-bit representations,
624 : otherwise we could just use ((unsigned)-1) >> 1 */
625 : unsigned ZLIB_INTERNAL gz_intmax()
626 : {
627 : unsigned p, q;
628 :
629 : p = 1;
630 : do {
631 : q = p;
632 : p <<= 1;
633 : p++;
634 : } while (p > q);
635 : return q >> 1;
636 : }
637 : #endif
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