2
* Copyright (c) 2003-2004 Tim Kientzle
5
* Redistribution and use in source and binary forms, with or without
6
* modification, are permitted provided that the following conditions
8
* 1. Redistributions of source code must retain the above copyright
9
* notice, this list of conditions and the following disclaimer
10
* in this position and unchanged.
11
* 2. Redistributions in binary form must reproduce the above copyright
12
* notice, this list of conditions and the following disclaimer in the
13
* documentation and/or other materials provided with the distribution.
15
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
16
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
19
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
#include "archive_platform.h"
29
__FBSDID("$FreeBSD: src/lib/libarchive/archive_read_support_compression_gzip.c,v 1.9 2005/03/13 01:48:33 kientzle Exp $");
41
#include "archive_private.h"
46
unsigned char *uncompressed_buffer;
47
size_t uncompressed_buffer_size;
48
unsigned char *read_next;
54
static int finish(struct archive *);
55
static ssize_t read_ahead(struct archive *, const void **, size_t);
56
static ssize_t read_consume(struct archive *, size_t);
57
static int drive_decompressor(struct archive *a, struct private_data *);
60
/* These two functions are defined even if we lack zlib. See below. */
61
static int bid(const void *, size_t);
62
static int init(struct archive *, const void *, size_t);
65
archive_read_support_compression_gzip(struct archive *a)
67
return (__archive_read_register_compression(a, bid, init));
71
* Test whether we can handle this data.
73
* This logic returns zero if any part of the signature fails. It
74
* also tries to Do The Right Thing if a very short buffer prevents us
75
* from verifying as much as we would like.
78
bid(const void *buff, size_t len)
80
const unsigned char *buffer;
88
if (buffer[0] != 037) /* Verify first ID byte. */
92
return (bits_checked);
94
if (buffer[1] != 0213) /* Verify second ID byte. */
98
return (bits_checked);
100
if (buffer[2] != 8) /* Compression must be 'deflate'. */
104
return (bits_checked);
106
if ((buffer[3] & 0xE0)!= 0) /* No reserved flags set. */
110
return (bits_checked);
113
* TODO: Verify more; in particular, gzip has an optional
114
* header CRC, which would give us 16 more verified bits. We
115
* may also be able to verify certain constraints on other
119
return (bits_checked);
126
* If we don't have zlib on this system, we can't actually do the
127
* decompression. We can, however, still detect gzip-compressed
128
* archives and emit a useful message.
131
init(struct archive *a, const void *buff, size_t n)
133
(void)a; /* UNUSED */
134
(void)buff; /* UNUSED */
135
(void)n; /* UNUSED */
137
archive_set_error(a, -1,
138
"This version of libarchive was compiled without gzip support");
139
return (ARCHIVE_FATAL);
146
* Setup the callbacks.
149
init(struct archive *a, const void *buff, size_t n)
151
struct private_data *state;
154
a->compression_code = ARCHIVE_COMPRESSION_GZIP;
155
a->compression_name = "gzip";
157
state = malloc(sizeof(*state));
159
archive_set_error(a, ENOMEM,
160
"Can't allocate data for %s decompression",
161
a->compression_name);
162
return (ARCHIVE_FATAL);
164
memset(state, 0, sizeof(*state));
166
state->crc = crc32(0L, NULL, 0);
167
state->header_done = 0; /* We've not yet begun to parse header... */
169
state->uncompressed_buffer_size = 64 * 1024;
170
state->uncompressed_buffer = malloc(state->uncompressed_buffer_size);
171
state->stream.next_out = state->uncompressed_buffer;
172
state->read_next = state->uncompressed_buffer;
173
state->stream.avail_out = state->uncompressed_buffer_size;
175
if (state->uncompressed_buffer == NULL) {
176
archive_set_error(a, ENOMEM,
177
"Can't allocate %s decompression buffers",
178
a->compression_name);
180
return (ARCHIVE_FATAL);
184
* A bug in zlib.h: stream.next_in should be marked 'const'
185
* but isn't (the library never alters data through the
186
* next_in pointer, only reads it). The result: this ugly
187
* cast to remove 'const'.
189
state->stream.next_in = (void *)(uintptr_t)(const void *)buff;
190
state->stream.avail_in = n;
192
a->compression_read_ahead = read_ahead;
193
a->compression_read_consume = read_consume;
194
a->compression_finish = finish;
197
* TODO: Do I need to parse the gzip header before calling
198
* inflateInit2()? In particular, one of the header bytes
199
* marks "best compression" or "fastest", which may be
200
* appropriate for setting the second parameter here.
201
* However, I think the only penalty for not setting it
202
* correctly is wasted memory. If this is necessary, it
203
* should probably go into drive_decompressor() below.
206
/* Initialize compression library. */
207
ret = inflateInit2(&(state->stream),
208
-15 /* Don't check for zlib header */);
210
a->compression_data = state;
214
/* Library setup failed: Clean up. */
215
archive_set_error(a, ARCHIVE_ERRNO_MISC,
216
"Internal error initializing %s library", a->compression_name);
217
free(state->uncompressed_buffer);
220
/* Override the error message if we know what really went wrong. */
223
archive_set_error(a, ARCHIVE_ERRNO_MISC,
224
"Internal error initializing compression library: "
225
"invalid setup parameter");
228
archive_set_error(a, ENOMEM,
229
"Internal error initializing compression library: "
232
case Z_VERSION_ERROR:
233
archive_set_error(a, ARCHIVE_ERRNO_MISC,
234
"Internal error initializing compression library: "
235
"invalid library version");
239
return (ARCHIVE_FATAL);
243
* Return a block of data from the decompression buffer. Decompress more
247
read_ahead(struct archive *a, const void **p, size_t min)
249
struct private_data *state;
250
int read_avail, was_avail, ret;
252
state = a->compression_data;
254
if (!a->client_reader) {
255
archive_set_error(a, ARCHIVE_ERRNO_PROGRAMMER,
256
"No read callback is registered? "
257
"This is probably an internal programming error.");
258
return (ARCHIVE_FATAL);
261
read_avail = state->stream.next_out - state->read_next;
263
if (read_avail + state->stream.avail_out < min) {
264
memmove(state->uncompressed_buffer, state->read_next,
266
state->read_next = state->uncompressed_buffer;
267
state->stream.next_out = state->read_next + read_avail;
268
state->stream.avail_out
269
= state->uncompressed_buffer_size - read_avail;
272
while (was_avail < read_avail && /* Made some progress. */
273
read_avail < (int)min && /* Haven't satisfied min. */
274
read_avail < (int)state->uncompressed_buffer_size) { /* !full */
275
if ((ret = drive_decompressor(a, state)) != ARCHIVE_OK)
277
was_avail = read_avail;
278
read_avail = state->stream.next_out - state->read_next;
281
*p = state->read_next;
286
* Mark a previously-returned block of data as read.
289
read_consume(struct archive *a, size_t n)
291
struct private_data *state;
293
state = a->compression_data;
294
a->file_position += n;
295
state->read_next += n;
296
if (state->read_next > state->stream.next_out)
297
__archive_errx(1, "Request to consume too many "
298
"bytes from gzip decompressor");
303
* Clean up the decompressor.
306
finish(struct archive *a)
308
struct private_data *state;
311
state = a->compression_data;
313
switch (inflateEnd(&(state->stream))) {
317
archive_set_error(a, ARCHIVE_ERRNO_MISC,
318
"Failed to clean up %s compressor", a->compression_name);
322
free(state->uncompressed_buffer);
325
a->compression_data = NULL;
326
if (a->client_closer != NULL)
327
(a->client_closer)(a, a->client_data);
333
* Utility function to pull data through decompressor, reading input
334
* blocks as necessary.
337
drive_decompressor(struct archive *a, struct private_data *state)
340
int decompressed, total_decompressed;
341
int count, flags, header_state;
342
unsigned char *output;
348
total_decompressed = 0;
350
if (state->stream.avail_in == 0) {
351
ret = (a->client_reader)(a, a->client_data,
352
(const void **)&state->stream.next_in);
355
* TODO: Find a better way to handle
360
if (ret == 0 && total_decompressed == 0) {
361
archive_set_error(a, EIO,
362
"Premature end of %s compressed data",
363
a->compression_name);
364
return (ARCHIVE_FATAL);
366
a->raw_position += ret;
367
state->stream.avail_in = ret;
370
if (!state->header_done) {
372
* If still parsing the header, interpret the
375
b = *(state->stream.next_in++);
376
state->stream.avail_in--;
379
* Yes, this is somewhat crude, but it works,
380
* GZip format isn't likely to change anytime
381
* in the near future, and header parsing is
382
* certainly not a performance issue, so
383
* there's little point in making this more
384
* elegant. Of course, if you see an easy way
385
* to make this more elegant, please let me
388
switch (header_state) {
389
case 0: /* First byte of signature. */
394
case 1: /* Second byte of signature. */
399
case 2: /* Compression type must be 8. */
404
case 3: /* GZip flags. */
408
case 4: case 5: case 6: case 7: /* Mod time. */
411
case 8: /* Deflate flags. */
417
case 10: /* Optional Extra: First byte of Length. */
419
count = 255 & (int)b;
424
* Fall through if there is no
425
* Optional Extra field.
427
case 11: /* Optional Extra: Second byte of Length. */
429
count = (0xff00 & ((int)b << 8)) | count;
434
* Fall through if there is no
435
* Optional Extra field.
437
case 12: /* Optional Extra Field: counted length. */
440
if (count == 0) header_state = 13;
441
else header_state = 12;
445
* Fall through if there is no
446
* Optional Extra field.
448
case 13: /* Optional Original Filename. */
450
if (b == 0) header_state = 14;
451
else header_state = 13;
455
* Fall through if no Optional
458
case 14: /* Optional Comment. */
460
if (b == 0) header_state = 15;
461
else header_state = 14;
464
/* Fall through if no Optional Comment. */
465
case 15: /* Optional Header CRC: First byte. */
470
/* Fall through if no Optional Header CRC. */
471
case 16: /* Optional Header CRC: Second byte. */
476
/* Fall through if no Optional Header CRC. */
477
case 17: /* First byte of compressed data. */
478
state->header_done = 1; /* done with header */
479
state->stream.avail_in++;
480
state->stream.next_in--;
484
* TODO: Consider moving the inflateInit2 call
485
* here so it can include the compression type
489
output = state->stream.next_out;
491
/* Decompress some data. */
492
ret = inflate(&(state->stream), 0);
493
decompressed = state->stream.next_out - output;
495
/* Accumulate the CRC of the uncompressed data. */
496
state->crc = crc32(state->crc, output, decompressed);
498
/* Accumulate the total bytes of output. */
499
state->total_out += decompressed;
500
total_decompressed += decompressed;
503
case Z_OK: /* Decompressor made some progress. */
504
if (decompressed > 0)
507
case Z_STREAM_END: /* Found end of stream. */
509
* TODO: Verify gzip trailer
510
* (uncompressed length and CRC).
514
/* Any other return value is an error. */
515
archive_set_error(a, ARCHIVE_ERRNO_MISC,
516
"gzip decompression failed (%s)",
524
/* Return a fatal error. */
526
archive_set_error(a, ARCHIVE_ERRNO_MISC, "%s decompression failed",
527
a->compression_name);
528
return (ARCHIVE_FATAL);
531
#endif /* HAVE_ZLIB_H */
added
removed
sources/libarchive-1.2.53/libarchive/archive_read_support_compression_gzip.c
