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1 | /* gzlib.c -- zlib functions common to reading and writing gzip files |
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2 | * Copyright (C) 2004-2024 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 | |
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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. */ |
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29 | char ZLIB_INTERNAL *gz_strwinerror(DWORD error) { |
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30 | static char buf[1024]; |
31 | |
32 | wchar_t *msgbuf; |
33 | DWORD lasterr = GetLastError(); |
34 | DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
35 | | FORMAT_MESSAGE_ALLOCATE_BUFFER, |
36 | NULL, |
37 | error, |
38 | 0, /* Default language */ |
39 | (LPVOID)&msgbuf, |
40 | 0, |
41 | NULL); |
42 | if (chars != 0) { |
43 | /* If there is an \r\n appended, zap it. */ |
44 | if (chars >= 2 |
45 | && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') { |
46 | chars -= 2; |
47 | msgbuf[chars] = 0; |
48 | } |
49 | |
50 | if (chars > sizeof (buf) - 1) { |
51 | chars = sizeof (buf) - 1; |
52 | msgbuf[chars] = 0; |
53 | } |
54 | |
55 | wcstombs(buf, msgbuf, chars + 1); |
56 | LocalFree(msgbuf); |
57 | } |
58 | else { |
59 | sprintf(buf, "unknown win32 error (%ld)", error); |
60 | } |
61 | |
62 | SetLastError(lasterr); |
63 | return buf; |
64 | } |
65 | |
66 | #endif /* UNDER_CE */ |
67 | |
68 | /* Reset gzip file state */ |
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69 | local void gz_reset(gz_statep state) { |
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70 | state->x.have = 0; /* no output data available */ |
71 | if (state->mode == GZ_READ) { /* for reading ... */ |
72 | state->eof = 0; /* not at end of file */ |
73 | state->past = 0; /* have not read past end yet */ |
74 | state->how = LOOK; /* look for gzip header */ |
75 | } |
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76 | else /* for writing ... */ |
77 | state->reset = 0; /* no deflateReset pending */ |
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78 | state->seek = 0; /* no seek request pending */ |
79 | gz_error(state, Z_OK, NULL); /* clear error */ |
80 | state->x.pos = 0; /* no uncompressed data yet */ |
81 | state->strm.avail_in = 0; /* no input data yet */ |
82 | } |
83 | |
84 | /* Open a gzip file either by name or file descriptor. */ |
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85 | local gzFile gz_open(const void *path, int fd, const char *mode) { |
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86 | gz_statep state; |
87 | z_size_t len; |
88 | int oflag; |
89 | #ifdef O_CLOEXEC |
90 | int cloexec = 0; |
91 | #endif |
92 | #ifdef O_EXCL |
93 | int exclusive = 0; |
94 | #endif |
95 | |
96 | /* check input */ |
97 | if (path == NULL) |
98 | return NULL; |
99 | |
100 | /* allocate gzFile structure to return */ |
101 | state = (gz_statep)malloc(sizeof(gz_state)); |
102 | if (state == NULL) |
103 | return NULL; |
104 | state->size = 0; /* no buffers allocated yet */ |
105 | state->want = GZBUFSIZE; /* requested buffer size */ |
106 | state->msg = NULL; /* no error message yet */ |
107 | |
108 | /* interpret mode */ |
109 | state->mode = GZ_NONE; |
110 | state->level = Z_DEFAULT_COMPRESSION; |
111 | state->strategy = Z_DEFAULT_STRATEGY; |
112 | state->direct = 0; |
113 | while (*mode) { |
114 | if (*mode >= '0' && *mode <= '9') |
115 | state->level = *mode - '0'; |
116 | else |
117 | switch (*mode) { |
118 | case 'r': |
119 | state->mode = GZ_READ; |
120 | break; |
121 | #ifndef NO_GZCOMPRESS |
122 | case 'w': |
123 | state->mode = GZ_WRITE; |
124 | break; |
125 | case 'a': |
126 | state->mode = GZ_APPEND; |
127 | break; |
128 | #endif |
129 | case '+': /* can't read and write at the same time */ |
130 | free(state); |
131 | return NULL; |
132 | case 'b': /* ignore -- will request binary anyway */ |
133 | break; |
134 | #ifdef O_CLOEXEC |
135 | case 'e': |
136 | cloexec = 1; |
137 | break; |
138 | #endif |
139 | #ifdef O_EXCL |
140 | case 'x': |
141 | exclusive = 1; |
142 | break; |
143 | #endif |
144 | case 'f': |
145 | state->strategy = Z_FILTERED; |
146 | break; |
147 | case 'h': |
148 | state->strategy = Z_HUFFMAN_ONLY; |
149 | break; |
150 | case 'R': |
151 | state->strategy = Z_RLE; |
152 | break; |
153 | case 'F': |
154 | state->strategy = Z_FIXED; |
155 | break; |
156 | case 'T': |
157 | state->direct = 1; |
158 | break; |
159 | default: /* could consider as an error, but just ignore */ |
160 | ; |
161 | } |
162 | mode++; |
163 | } |
164 | |
165 | /* must provide an "r", "w", or "a" */ |
166 | if (state->mode == GZ_NONE) { |
167 | free(state); |
168 | return NULL; |
169 | } |
170 | |
171 | /* can't force transparent read */ |
172 | if (state->mode == GZ_READ) { |
173 | if (state->direct) { |
174 | free(state); |
175 | return NULL; |
176 | } |
177 | state->direct = 1; /* for empty file */ |
178 | } |
179 | |
180 | /* save the path name for error messages */ |
181 | #ifdef WIDECHAR |
182 | if (fd == -2) { |
183 | len = wcstombs(NULL, path, 0); |
184 | if (len == (z_size_t)-1) |
185 | len = 0; |
186 | } |
187 | else |
188 | #endif |
189 | len = strlen((const char *)path); |
190 | state->path = (char *)malloc(len + 1); |
191 | if (state->path == NULL) { |
192 | free(state); |
193 | return NULL; |
194 | } |
195 | #ifdef WIDECHAR |
196 | if (fd == -2) |
197 | if (len) |
198 | wcstombs(state->path, path, len + 1); |
199 | else |
200 | *(state->path) = 0; |
201 | else |
202 | #endif |
203 | #if !defined(NO_snprintf) && !defined(NO_vsnprintf) |
204 | (void)snprintf(state->path, len + 1, "%s", (const char *)path); |
205 | #else |
206 | strcpy(state->path, path); |
207 | #endif |
208 | |
209 | /* compute the flags for open() */ |
210 | oflag = |
211 | #ifdef O_LARGEFILE |
212 | O_LARGEFILE | |
213 | #endif |
214 | #ifdef O_BINARY |
215 | O_BINARY | |
216 | #endif |
217 | #ifdef O_CLOEXEC |
218 | (cloexec ? O_CLOEXEC : 0) | |
219 | #endif |
220 | (state->mode == GZ_READ ? |
221 | O_RDONLY : |
222 | (O_WRONLY | O_CREAT | |
223 | #ifdef O_EXCL |
224 | (exclusive ? O_EXCL : 0) | |
225 | #endif |
226 | (state->mode == GZ_WRITE ? |
227 | O_TRUNC : |
228 | O_APPEND))); |
229 | |
230 | /* open the file with the appropriate flags (or just use fd) */ |
231 | state->fd = fd > -1 ? fd : ( |
232 | #ifdef WIDECHAR |
233 | fd == -2 ? _wopen(path, oflag, 0666) : |
234 | #endif |
235 | open((const char *)path, oflag, 0666)); |
236 | if (state->fd == -1) { |
237 | free(state->path); |
238 | free(state); |
239 | return NULL; |
240 | } |
241 | if (state->mode == GZ_APPEND) { |
242 | LSEEK(state->fd, 0, SEEK_END); /* so gzoffset() is correct */ |
243 | state->mode = GZ_WRITE; /* simplify later checks */ |
244 | } |
245 | |
246 | /* save the current position for rewinding (only if reading) */ |
247 | if (state->mode == GZ_READ) { |
248 | state->start = LSEEK(state->fd, 0, SEEK_CUR); |
249 | if (state->start == -1) state->start = 0; |
250 | } |
251 | |
252 | /* initialize stream */ |
253 | gz_reset(state); |
254 | |
255 | /* return stream */ |
256 | return (gzFile)state; |
257 | } |
258 | |
259 | /* -- see zlib.h -- */ |
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260 | gzFile ZEXPORT gzopen(const char *path, const char *mode) { |
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261 | return gz_open(path, -1, mode); |
262 | } |
263 | |
264 | /* -- see zlib.h -- */ |
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265 | gzFile ZEXPORT gzopen64(const char *path, const char *mode) { |
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266 | return gz_open(path, -1, mode); |
267 | } |
268 | |
269 | /* -- see zlib.h -- */ |
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270 | gzFile ZEXPORT gzdopen(int fd, const char *mode) { |
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271 | char *path; /* identifier for error messages */ |
272 | gzFile gz; |
273 | |
274 | if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL) |
275 | return NULL; |
276 | #if !defined(NO_snprintf) && !defined(NO_vsnprintf) |
277 | (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd); |
278 | #else |
279 | sprintf(path, "<fd:%d>", fd); /* for debugging */ |
280 | #endif |
281 | gz = gz_open(path, fd, mode); |
282 | free(path); |
283 | return gz; |
284 | } |
285 | |
286 | /* -- see zlib.h -- */ |
287 | #ifdef WIDECHAR |
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288 | gzFile ZEXPORT gzopen_w(const wchar_t *path, const char *mode) { |
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289 | return gz_open(path, -2, mode); |
290 | } |
291 | #endif |
292 | |
293 | /* -- see zlib.h -- */ |
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294 | int ZEXPORT gzbuffer(gzFile file, unsigned size) { |
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295 | gz_statep state; |
296 | |
297 | /* get internal structure and check integrity */ |
298 | if (file == NULL) |
299 | return -1; |
300 | state = (gz_statep)file; |
301 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
302 | return -1; |
303 | |
304 | /* make sure we haven't already allocated memory */ |
305 | if (state->size != 0) |
306 | return -1; |
307 | |
308 | /* check and set requested size */ |
309 | if ((size << 1) < size) |
310 | return -1; /* need to be able to double it */ |
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311 | if (size < 8) |
312 | size = 8; /* needed to behave well with flushing */ |
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313 | state->want = size; |
314 | return 0; |
315 | } |
316 | |
317 | /* -- see zlib.h -- */ |
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318 | int ZEXPORT gzrewind(gzFile file) { |
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319 | gz_statep state; |
320 | |
321 | /* get internal structure */ |
322 | if (file == NULL) |
323 | return -1; |
324 | state = (gz_statep)file; |
325 | |
326 | /* check that we're reading and that there's no error */ |
327 | if (state->mode != GZ_READ || |
328 | (state->err != Z_OK && state->err != Z_BUF_ERROR)) |
329 | return -1; |
330 | |
331 | /* back up and start over */ |
332 | if (LSEEK(state->fd, state->start, SEEK_SET) == -1) |
333 | return -1; |
334 | gz_reset(state); |
335 | return 0; |
336 | } |
337 | |
338 | /* -- see zlib.h -- */ |
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339 | z_off64_t ZEXPORT gzseek64(gzFile file, z_off64_t offset, int whence) { |
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340 | unsigned n; |
341 | z_off64_t ret; |
342 | gz_statep state; |
343 | |
344 | /* get internal structure and check integrity */ |
345 | if (file == NULL) |
346 | return -1; |
347 | state = (gz_statep)file; |
348 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
349 | return -1; |
350 | |
351 | /* check that there's no error */ |
352 | if (state->err != Z_OK && state->err != Z_BUF_ERROR) |
353 | return -1; |
354 | |
355 | /* can only seek from start or relative to current position */ |
356 | if (whence != SEEK_SET && whence != SEEK_CUR) |
357 | return -1; |
358 | |
359 | /* normalize offset to a SEEK_CUR specification */ |
360 | if (whence == SEEK_SET) |
361 | offset -= state->x.pos; |
362 | else if (state->seek) |
363 | offset += state->skip; |
364 | state->seek = 0; |
365 | |
366 | /* if within raw area while reading, just go there */ |
367 | if (state->mode == GZ_READ && state->how == COPY && |
368 | state->x.pos + offset >= 0) { |
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369 | ret = LSEEK(state->fd, offset - (z_off64_t)state->x.have, SEEK_CUR); |
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370 | if (ret == -1) |
371 | return -1; |
372 | state->x.have = 0; |
373 | state->eof = 0; |
374 | state->past = 0; |
375 | state->seek = 0; |
376 | gz_error(state, Z_OK, NULL); |
377 | state->strm.avail_in = 0; |
378 | state->x.pos += offset; |
379 | return state->x.pos; |
380 | } |
381 | |
382 | /* calculate skip amount, rewinding if needed for back seek when reading */ |
383 | if (offset < 0) { |
384 | if (state->mode != GZ_READ) /* writing -- can't go backwards */ |
385 | return -1; |
386 | offset += state->x.pos; |
387 | if (offset < 0) /* before start of file! */ |
388 | return -1; |
389 | if (gzrewind(file) == -1) /* rewind, then skip to offset */ |
390 | return -1; |
391 | } |
392 | |
393 | /* if reading, skip what's in output buffer (one less gzgetc() check) */ |
394 | if (state->mode == GZ_READ) { |
395 | n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ? |
396 | (unsigned)offset : state->x.have; |
397 | state->x.have -= n; |
398 | state->x.next += n; |
399 | state->x.pos += n; |
400 | offset -= n; |
401 | } |
402 | |
403 | /* request skip (if not zero) */ |
404 | if (offset) { |
405 | state->seek = 1; |
406 | state->skip = offset; |
407 | } |
408 | return state->x.pos + offset; |
409 | } |
410 | |
411 | /* -- see zlib.h -- */ |
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412 | z_off_t ZEXPORT gzseek(gzFile file, z_off_t offset, int whence) { |
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413 | z_off64_t ret; |
414 | |
415 | ret = gzseek64(file, (z_off64_t)offset, whence); |
416 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
417 | } |
418 | |
419 | /* -- see zlib.h -- */ |
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420 | z_off64_t ZEXPORT gztell64(gzFile file) { |
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421 | gz_statep state; |
422 | |
423 | /* get internal structure and check integrity */ |
424 | if (file == NULL) |
425 | return -1; |
426 | state = (gz_statep)file; |
427 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
428 | return -1; |
429 | |
430 | /* return position */ |
431 | return state->x.pos + (state->seek ? state->skip : 0); |
432 | } |
433 | |
434 | /* -- see zlib.h -- */ |
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435 | z_off_t ZEXPORT gztell(gzFile file) { |
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436 | z_off64_t ret; |
437 | |
438 | ret = gztell64(file); |
439 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
440 | } |
441 | |
442 | /* -- see zlib.h -- */ |
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443 | z_off64_t ZEXPORT gzoffset64(gzFile file) { |
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444 | z_off64_t offset; |
445 | gz_statep state; |
446 | |
447 | /* get internal structure and check integrity */ |
448 | if (file == NULL) |
449 | return -1; |
450 | state = (gz_statep)file; |
451 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
452 | return -1; |
453 | |
454 | /* compute and return effective offset in file */ |
455 | offset = LSEEK(state->fd, 0, SEEK_CUR); |
456 | if (offset == -1) |
457 | return -1; |
458 | if (state->mode == GZ_READ) /* reading */ |
459 | offset -= state->strm.avail_in; /* don't count buffered input */ |
460 | return offset; |
461 | } |
462 | |
463 | /* -- see zlib.h -- */ |
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464 | z_off_t ZEXPORT gzoffset(gzFile file) { |
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465 | z_off64_t ret; |
466 | |
467 | ret = gzoffset64(file); |
468 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
469 | } |
470 | |
471 | /* -- see zlib.h -- */ |
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472 | int ZEXPORT gzeof(gzFile file) { |
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473 | gz_statep state; |
474 | |
475 | /* get internal structure and check integrity */ |
476 | if (file == NULL) |
477 | return 0; |
478 | state = (gz_statep)file; |
479 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
480 | return 0; |
481 | |
482 | /* return end-of-file state */ |
483 | return state->mode == GZ_READ ? state->past : 0; |
484 | } |
485 | |
486 | /* -- see zlib.h -- */ |
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487 | const char * ZEXPORT gzerror(gzFile file, int *errnum) { |
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488 | gz_statep state; |
489 | |
490 | /* get internal structure and check integrity */ |
491 | if (file == NULL) |
492 | return NULL; |
493 | state = (gz_statep)file; |
494 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
495 | return NULL; |
496 | |
497 | /* return error information */ |
498 | if (errnum != NULL) |
499 | *errnum = state->err; |
500 | return state->err == Z_MEM_ERROR ? "out of memory" : |
501 | (state->msg == NULL ? "" : state->msg); |
502 | } |
503 | |
504 | /* -- see zlib.h -- */ |
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505 | void ZEXPORT gzclearerr(gzFile file) { |
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506 | gz_statep state; |
507 | |
508 | /* get internal structure and check integrity */ |
509 | if (file == NULL) |
510 | return; |
511 | state = (gz_statep)file; |
512 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
513 | return; |
514 | |
515 | /* clear error and end-of-file */ |
516 | if (state->mode == GZ_READ) { |
517 | state->eof = 0; |
518 | state->past = 0; |
519 | } |
520 | gz_error(state, Z_OK, NULL); |
521 | } |
522 | |
523 | /* Create an error message in allocated memory and set state->err and |
524 | state->msg accordingly. Free any previous error message already there. Do |
525 | not try to free or allocate space if the error is Z_MEM_ERROR (out of |
526 | memory). Simply save the error message as a static string. If there is an |
527 | allocation failure constructing the error message, then convert the error to |
528 | out of memory. */ |
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529 | void ZLIB_INTERNAL gz_error(gz_statep state, int err, const char *msg) { |
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530 | /* free previously allocated message and clear */ |
531 | if (state->msg != NULL) { |
532 | if (state->err != Z_MEM_ERROR) |
533 | free(state->msg); |
534 | state->msg = NULL; |
535 | } |
536 | |
537 | /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */ |
538 | if (err != Z_OK && err != Z_BUF_ERROR) |
539 | state->x.have = 0; |
540 | |
541 | /* set error code, and if no message, then done */ |
542 | state->err = err; |
543 | if (msg == NULL) |
544 | return; |
545 | |
546 | /* for an out of memory error, return literal string when requested */ |
547 | if (err == Z_MEM_ERROR) |
548 | return; |
549 | |
550 | /* construct error message with path */ |
551 | if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) == |
552 | NULL) { |
553 | state->err = Z_MEM_ERROR; |
554 | return; |
555 | } |
556 | #if !defined(NO_snprintf) && !defined(NO_vsnprintf) |
557 | (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3, |
558 | "%s%s%s", state->path, ": ", msg); |
559 | #else |
560 | strcpy(state->msg, state->path); |
561 | strcat(state->msg, ": "); |
562 | strcat(state->msg, msg); |
563 | #endif |
564 | } |
565 | |
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566 | /* portably return maximum value for an int (when limits.h presumed not |
567 | available) -- we need to do this to cover cases where 2's complement not |
568 | used, since C standard permits 1's complement and sign-bit representations, |
569 | otherwise we could just use ((unsigned)-1) >> 1 */ |
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570 | unsigned ZLIB_INTERNAL gz_intmax(void) { |
571 | #ifdef INT_MAX |
572 | return INT_MAX; |
573 | #else |
574 | unsigned p = 1, q; |
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575 | do { |
576 | q = p; |
577 | p <<= 1; |
578 | p++; |
579 | } while (p > q); |
580 | return q >> 1; |
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581 | #endif |
648db22b |
582 | } |