modules/zlib/src/gzlib.c@6474c204b198
modules/zlib/src/gzlib.c
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
1 /* gzlib.c -- zlib functions common to reading and writing gzip files
2 * Copyright (C) 2004, 2010, 2011, 2012, 2013 Mark Adler
3 * For conditions of distribution and use, see copyright notice in zlib.h
4 */
6 #include "gzguts.h"
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
18 /* Local functions */
19 local void gz_reset OF((gz_statep));
20 local gzFile gz_open OF((const void *, int, const char *));
22 #if defined UNDER_CE
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.
28 The string pointed to shall not be modified by the application, but may be
29 overwritten by a subsequent call to gz_strwinerror
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];
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 }
56 if (chars > sizeof (buf) - 1) {
57 chars = sizeof (buf) - 1;
58 msgbuf[chars] = 0;
59 }
61 wcstombs(buf, msgbuf, chars + 1);
62 LocalFree(msgbuf);
63 }
64 else {
65 sprintf(buf, "unknown win32 error (%ld)", error);
66 }
68 SetLastError(lasterr);
69 return buf;
70 }
72 #endif /* UNDER_CE */
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 }
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
106 /* check input */
107 if (path == NULL)
108 return NULL;
110 /* allocate gzFile structure to return */
111 state = (gz_statep)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 */
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 break;
166 case 'T':
167 state->direct = 1;
168 break;
169 default: /* could consider as an error, but just ignore */
170 ;
171 }
172 mode++;
173 }
175 /* must provide an "r", "w", or "a" */
176 if (state->mode == GZ_NONE) {
177 free(state);
178 return NULL;
179 }
181 /* can't force transparent read */
182 if (state->mode == GZ_READ) {
183 if (state->direct) {
184 free(state);
185 return NULL;
186 }
187 state->direct = 1; /* for empty file */
188 }
190 /* save the path name for error messages */
191 #ifdef _WIN32
192 if (fd == -2) {
193 len = wcstombs(NULL, path, 0);
194 if (len == (size_t)-1)
195 len = 0;
196 }
197 else
198 #endif
199 len = strlen((const char *)path);
200 state->path = (char *)malloc(len + 1);
201 if (state->path == NULL) {
202 free(state);
203 return NULL;
204 }
205 #ifdef _WIN32
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 snprintf(state->path, len + 1, "%s", (const char *)path);
215 #else
216 strcpy(state->path, path);
217 #endif
219 /* compute the flags for open() */
220 oflag =
221 #ifdef O_LARGEFILE
222 O_LARGEFILE |
223 #endif
224 #ifdef O_BINARY
225 O_BINARY |
226 #endif
227 #ifdef O_CLOEXEC
228 (cloexec ? O_CLOEXEC : 0) |
229 #endif
230 (state->mode == GZ_READ ?
231 O_RDONLY :
232 (O_WRONLY | O_CREAT |
233 #ifdef O_EXCL
234 (exclusive ? O_EXCL : 0) |
235 #endif
236 (state->mode == GZ_WRITE ?
237 O_TRUNC :
238 O_APPEND)));
240 /* open the file with the appropriate flags (or just use fd) */
241 state->fd = fd > -1 ? fd : (
242 #ifdef _WIN32
243 fd == -2 ? _wopen(path, oflag, 0666) :
244 #endif
245 open((const char *)path, oflag, 0666));
246 if (state->fd == -1) {
247 free(state->path);
248 free(state);
249 return NULL;
250 }
251 if (state->mode == GZ_APPEND)
252 state->mode = GZ_WRITE; /* simplify later checks */
254 /* save the current position for rewinding (only if reading) */
255 if (state->mode == GZ_READ) {
256 state->start = LSEEK(state->fd, 0, SEEK_CUR);
257 if (state->start == -1) state->start = 0;
258 }
260 /* initialize stream */
261 gz_reset(state);
263 /* return stream */
264 return (gzFile)state;
265 }
267 /* -- see zlib.h -- */
268 gzFile ZEXPORT gzopen(path, mode)
269 const char *path;
270 const char *mode;
271 {
272 return gz_open(path, -1, mode);
273 }
275 /* -- see zlib.h -- */
276 gzFile ZEXPORT gzopen64(path, mode)
277 const char *path;
278 const char *mode;
279 {
280 return gz_open(path, -1, mode);
281 }
283 /* -- see zlib.h -- */
284 gzFile ZEXPORT gzdopen(fd, mode)
285 int fd;
286 const char *mode;
287 {
288 char *path; /* identifier for error messages */
289 gzFile gz;
291 if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL)
292 return NULL;
293 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
294 snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd); /* for debugging */
295 #else
296 sprintf(path, "<fd:%d>", fd); /* for debugging */
297 #endif
298 gz = gz_open(path, fd, mode);
299 free(path);
300 return gz;
301 }
303 /* -- see zlib.h -- */
304 #ifdef _WIN32
305 gzFile ZEXPORT gzopen_w(path, mode)
306 const wchar_t *path;
307 const char *mode;
308 {
309 return gz_open(path, -2, mode);
310 }
311 #endif
313 /* -- see zlib.h -- */
314 int ZEXPORT gzbuffer(file, size)
315 gzFile file;
316 unsigned size;
317 {
318 gz_statep state;
320 /* get internal structure and check integrity */
321 if (file == NULL)
322 return -1;
323 state = (gz_statep)file;
324 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
325 return -1;
327 /* make sure we haven't already allocated memory */
328 if (state->size != 0)
329 return -1;
331 /* check and set requested size */
332 if (size < 2)
333 size = 2; /* need two bytes to check magic header */
334 state->want = size;
335 return 0;
336 }
338 /* -- see zlib.h -- */
339 int ZEXPORT gzrewind(file)
340 gzFile file;
341 {
342 gz_statep state;
344 /* get internal structure */
345 if (file == NULL)
346 return -1;
347 state = (gz_statep)file;
349 /* check that we're reading and that there's no error */
350 if (state->mode != GZ_READ ||
351 (state->err != Z_OK && state->err != Z_BUF_ERROR))
352 return -1;
354 /* back up and start over */
355 if (LSEEK(state->fd, state->start, SEEK_SET) == -1)
356 return -1;
357 gz_reset(state);
358 return 0;
359 }
361 /* -- see zlib.h -- */
362 z_off64_t ZEXPORT gzseek64(file, offset, whence)
363 gzFile file;
364 z_off64_t offset;
365 int whence;
366 {
367 unsigned n;
368 z_off64_t ret;
369 gz_statep state;
371 /* get internal structure and check integrity */
372 if (file == NULL)
373 return -1;
374 state = (gz_statep)file;
375 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
376 return -1;
378 /* check that there's no error */
379 if (state->err != Z_OK && state->err != Z_BUF_ERROR)
380 return -1;
382 /* can only seek from start or relative to current position */
383 if (whence != SEEK_SET && whence != SEEK_CUR)
384 return -1;
386 /* normalize offset to a SEEK_CUR specification */
387 if (whence == SEEK_SET)
388 offset -= state->x.pos;
389 else if (state->seek)
390 offset += state->skip;
391 state->seek = 0;
393 /* if within raw area while reading, just go there */
394 if (state->mode == GZ_READ && state->how == COPY &&
395 state->x.pos + offset >= 0) {
396 ret = LSEEK(state->fd, offset - state->x.have, SEEK_CUR);
397 if (ret == -1)
398 return -1;
399 state->x.have = 0;
400 state->eof = 0;
401 state->past = 0;
402 state->seek = 0;
403 gz_error(state, Z_OK, NULL);
404 state->strm.avail_in = 0;
405 state->x.pos += offset;
406 return state->x.pos;
407 }
409 /* calculate skip amount, rewinding if needed for back seek when reading */
410 if (offset < 0) {
411 if (state->mode != GZ_READ) /* writing -- can't go backwards */
412 return -1;
413 offset += state->x.pos;
414 if (offset < 0) /* before start of file! */
415 return -1;
416 if (gzrewind(file) == -1) /* rewind, then skip to offset */
417 return -1;
418 }
420 /* if reading, skip what's in output buffer (one less gzgetc() check) */
421 if (state->mode == GZ_READ) {
422 n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ?
423 (unsigned)offset : state->x.have;
424 state->x.have -= n;
425 state->x.next += n;
426 state->x.pos += n;
427 offset -= n;
428 }
430 /* request skip (if not zero) */
431 if (offset) {
432 state->seek = 1;
433 state->skip = offset;
434 }
435 return state->x.pos + offset;
436 }
438 /* -- see zlib.h -- */
439 z_off_t ZEXPORT gzseek(file, offset, whence)
440 gzFile file;
441 z_off_t offset;
442 int whence;
443 {
444 z_off64_t ret;
446 ret = gzseek64(file, (z_off64_t)offset, whence);
447 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
448 }
450 /* -- see zlib.h -- */
451 z_off64_t ZEXPORT gztell64(file)
452 gzFile file;
453 {
454 gz_statep state;
456 /* get internal structure and check integrity */
457 if (file == NULL)
458 return -1;
459 state = (gz_statep)file;
460 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
461 return -1;
463 /* return position */
464 return state->x.pos + (state->seek ? state->skip : 0);
465 }
467 /* -- see zlib.h -- */
468 z_off_t ZEXPORT gztell(file)
469 gzFile file;
470 {
471 z_off64_t ret;
473 ret = gztell64(file);
474 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
475 }
477 /* -- see zlib.h -- */
478 z_off64_t ZEXPORT gzoffset64(file)
479 gzFile file;
480 {
481 z_off64_t offset;
482 gz_statep state;
484 /* get internal structure and check integrity */
485 if (file == NULL)
486 return -1;
487 state = (gz_statep)file;
488 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
489 return -1;
491 /* compute and return effective offset in file */
492 offset = LSEEK(state->fd, 0, SEEK_CUR);
493 if (offset == -1)
494 return -1;
495 if (state->mode == GZ_READ) /* reading */
496 offset -= state->strm.avail_in; /* don't count buffered input */
497 return offset;
498 }
500 /* -- see zlib.h -- */
501 z_off_t ZEXPORT gzoffset(file)
502 gzFile file;
503 {
504 z_off64_t ret;
506 ret = gzoffset64(file);
507 return ret == (z_off_t)ret ? (z_off_t)ret : -1;
508 }
510 /* -- see zlib.h -- */
511 int ZEXPORT gzeof(file)
512 gzFile file;
513 {
514 gz_statep state;
516 /* get internal structure and check integrity */
517 if (file == NULL)
518 return 0;
519 state = (gz_statep)file;
520 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
521 return 0;
523 /* return end-of-file state */
524 return state->mode == GZ_READ ? state->past : 0;
525 }
527 /* -- see zlib.h -- */
528 const char * ZEXPORT gzerror(file, errnum)
529 gzFile file;
530 int *errnum;
531 {
532 gz_statep state;
534 /* get internal structure and check integrity */
535 if (file == NULL)
536 return NULL;
537 state = (gz_statep)file;
538 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
539 return NULL;
541 /* return error information */
542 if (errnum != NULL)
543 *errnum = state->err;
544 return state->err == Z_MEM_ERROR ? "out of memory" :
545 (state->msg == NULL ? "" : state->msg);
546 }
548 /* -- see zlib.h -- */
549 void ZEXPORT gzclearerr(file)
550 gzFile file;
551 {
552 gz_statep state;
554 /* get internal structure and check integrity */
555 if (file == NULL)
556 return;
557 state = (gz_statep)file;
558 if (state->mode != GZ_READ && state->mode != GZ_WRITE)
559 return;
561 /* clear error and end-of-file */
562 if (state->mode == GZ_READ) {
563 state->eof = 0;
564 state->past = 0;
565 }
566 gz_error(state, Z_OK, NULL);
567 }
569 /* Create an error message in allocated memory and set state->err and
570 state->msg accordingly. Free any previous error message already there. Do
571 not try to free or allocate space if the error is Z_MEM_ERROR (out of
572 memory). Simply save the error message as a static string. If there is an
573 allocation failure constructing the error message, then convert the error to
574 out of memory. */
575 void ZLIB_INTERNAL gz_error(state, err, msg)
576 gz_statep state;
577 int err;
578 const char *msg;
579 {
580 /* free previously allocated message and clear */
581 if (state->msg != NULL) {
582 if (state->err != Z_MEM_ERROR)
583 free(state->msg);
584 state->msg = NULL;
585 }
587 /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
588 if (err != Z_OK && err != Z_BUF_ERROR)
589 state->x.have = 0;
591 /* set error code, and if no message, then done */
592 state->err = err;
593 if (msg == NULL)
594 return;
596 /* for an out of memory error, return literal string when requested */
597 if (err == Z_MEM_ERROR)
598 return;
600 /* construct error message with path */
601 if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
602 NULL) {
603 state->err = Z_MEM_ERROR;
604 return;
605 }
606 #if !defined(NO_snprintf) && !defined(NO_vsnprintf)
607 snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
608 "%s%s%s", state->path, ": ", msg);
609 #else
610 strcpy(state->msg, state->path);
611 strcat(state->msg, ": ");
612 strcat(state->msg, msg);
613 #endif
614 return;
615 }
617 #ifndef INT_MAX
618 /* portably return maximum value for an int (when limits.h presumed not
619 available) -- we need to do this to cover cases where 2's complement not
620 used, since C standard permits 1's complement and sign-bit representations,
621 otherwise we could just use ((unsigned)-1) >> 1 */
622 unsigned ZLIB_INTERNAL gz_intmax()
623 {
624 unsigned p, q;
626 p = 1;
627 do {
628 q = p;
629 p <<= 1;
630 p++;
631 } while (p > q);
632 return q >> 1;
633 }
634 #endif
