]>
Commit | Line | Data |
---|---|---|
43743d63 MK |
1 | /* gzlib.c -- zlib functions common to reading and writing gzip files |
2 | * Copyright (C) 2004, 2010 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(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 | |
9 | # define LSEEK lseek64 | |
10 | #else | |
11 | # define LSEEK lseek | |
12 | #endif | |
13 | ||
14 | /* Local functions */ | |
15 | local void gz_reset OF((gz_statep)); | |
16 | local gzFile gz_open OF((const char *, int, const char *)); | |
17 | ||
18 | #if defined UNDER_CE | |
19 | ||
20 | /* Map the Windows error number in ERROR to a locale-dependent error message | |
21 | string and return a pointer to it. Typically, the values for ERROR come | |
22 | from GetLastError. | |
23 | ||
24 | The string pointed to shall not be modified by the application, but may be | |
25 | overwritten by a subsequent call to gz_strwinerror | |
26 | ||
27 | The gz_strwinerror function does not change the current setting of | |
28 | GetLastError. */ | |
29 | char ZLIB_INTERNAL *gz_strwinerror (error) | |
30 | DWORD error; | |
31 | { | |
32 | static char buf[1024]; | |
33 | ||
34 | wchar_t *msgbuf; | |
35 | DWORD lasterr = GetLastError(); | |
36 | DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | |
37 | | FORMAT_MESSAGE_ALLOCATE_BUFFER, | |
38 | NULL, | |
39 | error, | |
40 | 0, /* Default language */ | |
41 | (LPVOID)&msgbuf, | |
42 | 0, | |
43 | NULL); | |
44 | if (chars != 0) { | |
45 | /* If there is an \r\n appended, zap it. */ | |
46 | if (chars >= 2 | |
47 | && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') { | |
48 | chars -= 2; | |
49 | msgbuf[chars] = 0; | |
50 | } | |
51 | ||
52 | if (chars > sizeof (buf) - 1) { | |
53 | chars = sizeof (buf) - 1; | |
54 | msgbuf[chars] = 0; | |
55 | } | |
56 | ||
57 | wcstombs(buf, msgbuf, chars + 1); | |
58 | LocalFree(msgbuf); | |
59 | } | |
60 | else { | |
61 | sprintf(buf, "unknown win32 error (%ld)", error); | |
62 | } | |
63 | ||
64 | SetLastError(lasterr); | |
65 | return buf; | |
66 | } | |
67 | ||
68 | #endif /* UNDER_CE */ | |
69 | ||
70 | /* Reset gzip file state */ | |
71 | local void gz_reset(state) | |
72 | gz_statep state; | |
73 | { | |
74 | if (state->mode == GZ_READ) { /* for reading ... */ | |
75 | state->have = 0; /* no output data available */ | |
76 | state->eof = 0; /* not at end of file */ | |
77 | state->how = LOOK; /* look for gzip header */ | |
78 | state->direct = 1; /* default for empty file */ | |
79 | } | |
80 | state->seek = 0; /* no seek request pending */ | |
81 | gz_error(state, Z_OK, NULL); /* clear error */ | |
82 | state->pos = 0; /* no uncompressed data yet */ | |
83 | state->strm.avail_in = 0; /* no input data yet */ | |
84 | } | |
85 | ||
86 | /* Open a gzip file either by name or file descriptor. */ | |
87 | local gzFile gz_open(path, fd, mode) | |
88 | const char *path; | |
89 | int fd; | |
90 | const char *mode; | |
91 | { | |
92 | gz_statep state; | |
93 | ||
94 | /* allocate gzFile structure to return */ | |
95 | state = malloc(sizeof(gz_state)); | |
96 | if (state == NULL) | |
97 | return NULL; | |
98 | state->size = 0; /* no buffers allocated yet */ | |
99 | state->want = GZBUFSIZE; /* requested buffer size */ | |
100 | state->msg = NULL; /* no error message yet */ | |
101 | ||
102 | /* interpret mode */ | |
103 | state->mode = GZ_NONE; | |
104 | state->level = Z_DEFAULT_COMPRESSION; | |
105 | state->strategy = Z_DEFAULT_STRATEGY; | |
106 | while (*mode) { | |
107 | if (*mode >= '0' && *mode <= '9') | |
108 | state->level = *mode - '0'; | |
109 | else | |
110 | switch (*mode) { | |
111 | case 'r': | |
112 | state->mode = GZ_READ; | |
113 | break; | |
114 | #ifndef NO_GZCOMPRESS | |
115 | case 'w': | |
116 | state->mode = GZ_WRITE; | |
117 | break; | |
118 | case 'a': | |
119 | state->mode = GZ_APPEND; | |
120 | break; | |
121 | #endif | |
122 | case '+': /* can't read and write at the same time */ | |
123 | free(state); | |
124 | return NULL; | |
125 | case 'b': /* ignore -- will request binary anyway */ | |
126 | break; | |
127 | case 'f': | |
128 | state->strategy = Z_FILTERED; | |
129 | break; | |
130 | case 'h': | |
131 | state->strategy = Z_HUFFMAN_ONLY; | |
132 | break; | |
133 | case 'R': | |
134 | state->strategy = Z_RLE; | |
135 | break; | |
136 | case 'F': | |
137 | state->strategy = Z_FIXED; | |
138 | default: /* could consider as an error, but just ignore */ | |
139 | ; | |
140 | } | |
141 | mode++; | |
142 | } | |
143 | ||
144 | /* must provide an "r", "w", or "a" */ | |
145 | if (state->mode == GZ_NONE) { | |
146 | free(state); | |
147 | return NULL; | |
148 | } | |
149 | ||
150 | /* save the path name for error messages */ | |
151 | state->path = malloc(strlen(path) + 1); | |
152 | if (state->path == NULL) { | |
153 | free(state); | |
154 | return NULL; | |
155 | } | |
156 | strcpy(state->path, path); | |
157 | ||
158 | /* open the file with the appropriate mode (or just use fd) */ | |
159 | state->fd = fd != -1 ? fd : | |
160 | open(path, | |
161 | #ifdef O_LARGEFILE | |
162 | O_LARGEFILE | | |
163 | #endif | |
164 | #ifdef O_BINARY | |
165 | O_BINARY | | |
166 | #endif | |
167 | (state->mode == GZ_READ ? | |
168 | O_RDONLY : | |
169 | (O_WRONLY | O_CREAT | ( | |
170 | state->mode == GZ_WRITE ? | |
171 | O_TRUNC : | |
172 | O_APPEND))), | |
173 | 0666); | |
174 | if (state->fd == -1) { | |
175 | free(state->path); | |
176 | free(state); | |
177 | return NULL; | |
178 | } | |
179 | if (state->mode == GZ_APPEND) | |
180 | state->mode = GZ_WRITE; /* simplify later checks */ | |
181 | ||
182 | /* save the current position for rewinding (only if reading) */ | |
183 | if (state->mode == GZ_READ) { | |
184 | state->start = LSEEK(state->fd, 0, SEEK_CUR); | |
185 | if (state->start == -1) state->start = 0; | |
186 | } | |
187 | ||
188 | /* initialize stream */ | |
189 | gz_reset(state); | |
190 | ||
191 | /* return stream */ | |
192 | return (gzFile)state; | |
193 | } | |
194 | ||
195 | /* -- see zlib.h -- */ | |
196 | gzFile ZEXPORT gzopen(path, mode) | |
197 | const char *path; | |
198 | const char *mode; | |
199 | { | |
200 | return gz_open(path, -1, mode); | |
201 | } | |
202 | ||
203 | /* -- see zlib.h -- */ | |
204 | gzFile ZEXPORT gzopen64(path, mode) | |
205 | const char *path; | |
206 | const char *mode; | |
207 | { | |
208 | return gz_open(path, -1, mode); | |
209 | } | |
210 | ||
211 | /* -- see zlib.h -- */ | |
212 | gzFile ZEXPORT gzdopen(fd, mode) | |
213 | int fd; | |
214 | const char *mode; | |
215 | { | |
216 | char *path; /* identifier for error messages */ | |
217 | gzFile gz; | |
218 | ||
219 | if (fd == -1 || (path = malloc(7 + 3 * sizeof(int))) == NULL) | |
220 | return NULL; | |
221 | sprintf(path, "<fd:%d>", fd); /* for debugging */ | |
222 | gz = gz_open(path, fd, mode); | |
223 | free(path); | |
224 | return gz; | |
225 | } | |
226 | ||
227 | /* -- see zlib.h -- */ | |
228 | int ZEXPORT gzbuffer(file, size) | |
229 | gzFile file; | |
230 | unsigned size; | |
231 | { | |
232 | gz_statep state; | |
233 | ||
234 | /* get internal structure and check integrity */ | |
235 | if (file == NULL) | |
236 | return -1; | |
237 | state = (gz_statep)file; | |
238 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
239 | return -1; | |
240 | ||
241 | /* make sure we haven't already allocated memory */ | |
242 | if (state->size != 0) | |
243 | return -1; | |
244 | ||
245 | /* check and set requested size */ | |
246 | if (size == 0) | |
247 | return -1; | |
248 | state->want = size; | |
249 | return 0; | |
250 | } | |
251 | ||
252 | /* -- see zlib.h -- */ | |
253 | int ZEXPORT gzrewind(file) | |
254 | gzFile file; | |
255 | { | |
256 | gz_statep state; | |
257 | ||
258 | /* get internal structure */ | |
259 | if (file == NULL) | |
260 | return -1; | |
261 | state = (gz_statep)file; | |
262 | ||
263 | /* check that we're reading and that there's no error */ | |
264 | if (state->mode != GZ_READ || state->err != Z_OK) | |
265 | return -1; | |
266 | ||
267 | /* back up and start over */ | |
268 | if (LSEEK(state->fd, state->start, SEEK_SET) == -1) | |
269 | return -1; | |
270 | gz_reset(state); | |
271 | return 0; | |
272 | } | |
273 | ||
274 | /* -- see zlib.h -- */ | |
275 | z_off64_t ZEXPORT gzseek64(file, offset, whence) | |
276 | gzFile file; | |
277 | z_off64_t offset; | |
278 | int whence; | |
279 | { | |
280 | unsigned n; | |
281 | z_off64_t ret; | |
282 | gz_statep state; | |
283 | ||
284 | /* get internal structure and check integrity */ | |
285 | if (file == NULL) | |
286 | return -1; | |
287 | state = (gz_statep)file; | |
288 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
289 | return -1; | |
290 | ||
291 | /* check that there's no error */ | |
292 | if (state->err != Z_OK) | |
293 | return -1; | |
294 | ||
295 | /* can only seek from start or relative to current position */ | |
296 | if (whence != SEEK_SET && whence != SEEK_CUR) | |
297 | return -1; | |
298 | ||
299 | /* normalize offset to a SEEK_CUR specification */ | |
300 | if (whence == SEEK_SET) | |
301 | offset -= state->pos; | |
302 | else if (state->seek) | |
303 | offset += state->skip; | |
304 | state->seek = 0; | |
305 | ||
306 | /* if within raw area while reading, just go there */ | |
307 | if (state->mode == GZ_READ && state->how == COPY && | |
308 | state->pos + offset >= state->raw) { | |
309 | ret = LSEEK(state->fd, offset - state->have, SEEK_CUR); | |
310 | if (ret == -1) | |
311 | return -1; | |
312 | state->have = 0; | |
313 | state->eof = 0; | |
314 | state->seek = 0; | |
315 | gz_error(state, Z_OK, NULL); | |
316 | state->strm.avail_in = 0; | |
317 | state->pos += offset; | |
318 | return state->pos; | |
319 | } | |
320 | ||
321 | /* calculate skip amount, rewinding if needed for back seek when reading */ | |
322 | if (offset < 0) { | |
323 | if (state->mode != GZ_READ) /* writing -- can't go backwards */ | |
324 | return -1; | |
325 | offset += state->pos; | |
326 | if (offset < 0) /* before start of file! */ | |
327 | return -1; | |
328 | if (gzrewind(file) == -1) /* rewind, then skip to offset */ | |
329 | return -1; | |
330 | } | |
331 | ||
332 | /* if reading, skip what's in output buffer (one less gzgetc() check) */ | |
333 | if (state->mode == GZ_READ) { | |
334 | n = GT_OFF(state->have) || (z_off64_t)state->have > offset ? | |
335 | (unsigned)offset : state->have; | |
336 | state->have -= n; | |
337 | state->next += n; | |
338 | state->pos += n; | |
339 | offset -= n; | |
340 | } | |
341 | ||
342 | /* request skip (if not zero) */ | |
343 | if (offset) { | |
344 | state->seek = 1; | |
345 | state->skip = offset; | |
346 | } | |
347 | return state->pos + offset; | |
348 | } | |
349 | ||
350 | /* -- see zlib.h -- */ | |
351 | z_off_t ZEXPORT gzseek(file, offset, whence) | |
352 | gzFile file; | |
353 | z_off_t offset; | |
354 | int whence; | |
355 | { | |
356 | z_off64_t ret; | |
357 | ||
358 | ret = gzseek64(file, (z_off64_t)offset, whence); | |
359 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; | |
360 | } | |
361 | ||
362 | /* -- see zlib.h -- */ | |
363 | z_off64_t ZEXPORT gztell64(file) | |
364 | gzFile file; | |
365 | { | |
366 | gz_statep state; | |
367 | ||
368 | /* get internal structure and check integrity */ | |
369 | if (file == NULL) | |
370 | return -1; | |
371 | state = (gz_statep)file; | |
372 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
373 | return -1; | |
374 | ||
375 | /* return position */ | |
376 | return state->pos + (state->seek ? state->skip : 0); | |
377 | } | |
378 | ||
379 | /* -- see zlib.h -- */ | |
380 | z_off_t ZEXPORT gztell(file) | |
381 | gzFile file; | |
382 | { | |
383 | z_off64_t ret; | |
384 | ||
385 | ret = gztell64(file); | |
386 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; | |
387 | } | |
388 | ||
389 | /* -- see zlib.h -- */ | |
390 | z_off64_t ZEXPORT gzoffset64(file) | |
391 | gzFile file; | |
392 | { | |
393 | z_off64_t offset; | |
394 | gz_statep state; | |
395 | ||
396 | /* get internal structure and check integrity */ | |
397 | if (file == NULL) | |
398 | return -1; | |
399 | state = (gz_statep)file; | |
400 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
401 | return -1; | |
402 | ||
403 | /* compute and return effective offset in file */ | |
404 | offset = LSEEK(state->fd, 0, SEEK_CUR); | |
405 | if (offset == -1) | |
406 | return -1; | |
407 | if (state->mode == GZ_READ) /* reading */ | |
408 | offset -= state->strm.avail_in; /* don't count buffered input */ | |
409 | return offset; | |
410 | } | |
411 | ||
412 | /* -- see zlib.h -- */ | |
413 | z_off_t ZEXPORT gzoffset(file) | |
414 | gzFile file; | |
415 | { | |
416 | z_off64_t ret; | |
417 | ||
418 | ret = gzoffset64(file); | |
419 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; | |
420 | } | |
421 | ||
422 | /* -- see zlib.h -- */ | |
423 | int ZEXPORT gzeof(file) | |
424 | gzFile file; | |
425 | { | |
426 | gz_statep state; | |
427 | ||
428 | /* get internal structure and check integrity */ | |
429 | if (file == NULL) | |
430 | return 0; | |
431 | state = (gz_statep)file; | |
432 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
433 | return 0; | |
434 | ||
435 | /* return end-of-file state */ | |
436 | return state->mode == GZ_READ ? | |
437 | (state->eof && state->strm.avail_in == 0 && state->have == 0) : 0; | |
438 | } | |
439 | ||
440 | /* -- see zlib.h -- */ | |
441 | const char * ZEXPORT gzerror(file, errnum) | |
442 | gzFile file; | |
443 | int *errnum; | |
444 | { | |
445 | gz_statep state; | |
446 | ||
447 | /* get internal structure and check integrity */ | |
448 | if (file == NULL) | |
449 | return NULL; | |
450 | state = (gz_statep)file; | |
451 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
452 | return NULL; | |
453 | ||
454 | /* return error information */ | |
455 | if (errnum != NULL) | |
456 | *errnum = state->err; | |
457 | return state->msg == NULL ? "" : state->msg; | |
458 | } | |
459 | ||
460 | /* -- see zlib.h -- */ | |
461 | void ZEXPORT gzclearerr(file) | |
462 | gzFile file; | |
463 | { | |
464 | gz_statep state; | |
465 | ||
466 | /* get internal structure and check integrity */ | |
467 | if (file == NULL) | |
468 | return; | |
469 | state = (gz_statep)file; | |
470 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) | |
471 | return; | |
472 | ||
473 | /* clear error and end-of-file */ | |
474 | if (state->mode == GZ_READ) | |
475 | state->eof = 0; | |
476 | gz_error(state, Z_OK, NULL); | |
477 | } | |
478 | ||
479 | /* Create an error message in allocated memory and set state->err and | |
480 | state->msg accordingly. Free any previous error message already there. Do | |
481 | not try to free or allocate space if the error is Z_MEM_ERROR (out of | |
482 | memory). Simply save the error message as a static string. If there is an | |
483 | allocation failure constructing the error message, then convert the error to | |
484 | out of memory. */ | |
485 | void ZLIB_INTERNAL gz_error(state, err, msg) | |
486 | gz_statep state; | |
487 | int err; | |
488 | const char *msg; | |
489 | { | |
490 | /* free previously allocated message and clear */ | |
491 | if (state->msg != NULL) { | |
492 | if (state->err != Z_MEM_ERROR) | |
493 | free(state->msg); | |
494 | state->msg = NULL; | |
495 | } | |
496 | ||
497 | /* set error code, and if no message, then done */ | |
498 | state->err = err; | |
499 | if (msg == NULL) | |
500 | return; | |
501 | ||
502 | /* for an out of memory error, save as static string */ | |
503 | if (err == Z_MEM_ERROR) { | |
504 | state->msg = (char *)msg; | |
505 | return; | |
506 | } | |
507 | ||
508 | /* construct error message with path */ | |
509 | if ((state->msg = malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) { | |
510 | state->err = Z_MEM_ERROR; | |
511 | state->msg = (char *)"out of memory"; | |
512 | return; | |
513 | } | |
514 | strcpy(state->msg, state->path); | |
515 | strcat(state->msg, ": "); | |
516 | strcat(state->msg, msg); | |
517 | return; | |
518 | } | |
519 | ||
520 | #ifndef INT_MAX | |
521 | /* portably return maximum value for an int (when limits.h presumed not | |
522 | available) -- we need to do this to cover cases where 2's complement not | |
523 | used, since C standard permits 1's complement and sign-bit representations, | |
524 | otherwise we could just use ((unsigned)-1) >> 1 */ | |
525 | unsigned ZLIB_INTERNAL gz_intmax() | |
526 | { | |
527 | unsigned p, q; | |
528 | ||
529 | p = 1; | |
530 | do { | |
531 | q = p; | |
532 | p <<= 1; | |
533 | p++; | |
534 | } while (p > q); | |
535 | return q >> 1; | |
536 | } | |
537 | #endif |