archive_read_support_compression_bzip2.c revision 229592 
1/*-
2 * Copyright (c) 2003-2007 Tim Kientzle
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "archive_platform.h"
27
28__FBSDID("$FreeBSD: stable/9/contrib/libarchive/libarchive/archive_read_support_compression_bzip2.c 229592 2012-01-05 12:06:54Z mm $");
29
30#ifdef HAVE_ERRNO_H
31#include <errno.h>
32#endif
33#include <stdio.h>
34#ifdef HAVE_STDLIB_H
35#include <stdlib.h>
36#endif
37#ifdef HAVE_STRING_H
38#include <string.h>
39#endif
40#ifdef HAVE_UNISTD_H
41#include <unistd.h>
42#endif
43#ifdef HAVE_BZLIB_H
44#include <bzlib.h>
45#endif
46
47#include "archive.h"
48#include "archive_private.h"
49#include "archive_read_private.h"
50
51#if defined(HAVE_BZLIB_H) && defined(BZ_CONFIG_ERROR)
52struct private_data {
53	bz_stream	 stream;
54	char		*out_block;
55	size_t		 out_block_size;
56	char		 valid; /* True = decompressor is initialized */
57	char		 eof; /* True = found end of compressed data. */
58};
59
60/* Bzip2 filter */
61static ssize_t	bzip2_filter_read(struct archive_read_filter *, const void **);
62static int	bzip2_filter_close(struct archive_read_filter *);
63#endif
64
65/*
66 * Note that we can detect bzip2 archives even if we can't decompress
67 * them.  (In fact, we like detecting them because we can give better
68 * error messages.)  So the bid framework here gets compiled even
69 * if bzlib is unavailable.
70 */
71static int	bzip2_reader_bid(struct archive_read_filter_bidder *, struct archive_read_filter *);
72static int	bzip2_reader_init(struct archive_read_filter *);
73static int	bzip2_reader_free(struct archive_read_filter_bidder *);
74
75int
76archive_read_support_compression_bzip2(struct archive *_a)
77{
78	struct archive_read *a = (struct archive_read *)_a;
79	struct archive_read_filter_bidder *reader = __archive_read_get_bidder(a);
80
81	if (reader == NULL)
82		return (ARCHIVE_FATAL);
83
84	reader->data = NULL;
85	reader->bid = bzip2_reader_bid;
86	reader->init = bzip2_reader_init;
87	reader->options = NULL;
88	reader->free = bzip2_reader_free;
89#if defined(HAVE_BZLIB_H) && defined(BZ_CONFIG_ERROR)
90	return (ARCHIVE_OK);
91#else
92	archive_set_error(_a, ARCHIVE_ERRNO_MISC,
93	    "Using external bunzip2 program");
94	return (ARCHIVE_WARN);
95#endif
96}
97
98static int
99bzip2_reader_free(struct archive_read_filter_bidder *self){
100	(void)self; /* UNUSED */
101	return (ARCHIVE_OK);
102}
103
104/*
105 * Test whether we can handle this data.
106 *
107 * This logic returns zero if any part of the signature fails.  It
108 * also tries to Do The Right Thing if a very short buffer prevents us
109 * from verifying as much as we would like.
110 */
111static int
112bzip2_reader_bid(struct archive_read_filter_bidder *self, struct archive_read_filter *filter)
113{
114	const unsigned char *buffer;
115	ssize_t avail;
116	int bits_checked;
117
118	(void)self; /* UNUSED */
119
120	/* Minimal bzip2 archive is 14 bytes. */
121	buffer = __archive_read_filter_ahead(filter, 14, &avail);
122	if (buffer == NULL)
123		return (0);
124
125	/* First three bytes must be "BZh" */
126	bits_checked = 0;
127	if (buffer[0] != 'B' || buffer[1] != 'Z' || buffer[2] != 'h')
128		return (0);
129	bits_checked += 24;
130
131	/* Next follows a compression flag which must be an ASCII digit. */
132	if (buffer[3] < '1' || buffer[3] > '9')
133		return (0);
134	bits_checked += 5;
135
136	/* After BZh[1-9], there must be either a data block
137	 * which begins with 0x314159265359 or an end-of-data
138	 * marker of 0x177245385090. */
139	if (memcmp(buffer + 4, "\x31\x41\x59\x26\x53\x59", 6) == 0)
140		bits_checked += 48;
141	else if (memcmp(buffer + 4, "\x17\x72\x45\x38\x50\x90", 6) == 0)
142		bits_checked += 48;
143	else
144		return (0);
145
146	return (bits_checked);
147}
148
149#if !defined(HAVE_BZLIB_H) || !defined(BZ_CONFIG_ERROR)
150
151/*
152 * If we don't have the library on this system, we can't actually do the
153 * decompression.  We can, however, still detect compressed archives
154 * and emit a useful message.
155 */
156static int
157bzip2_reader_init(struct archive_read_filter *self)
158{
159	int r;
160
161	r = __archive_read_program(self, "bunzip2");
162	/* Note: We set the format here even if __archive_read_program()
163	 * above fails.  We do, after all, know what the format is
164	 * even if we weren't able to read it. */
165	self->code = ARCHIVE_COMPRESSION_BZIP2;
166	self->name = "bzip2";
167	return (r);
168}
169
170
171#else
172
173/*
174 * Setup the callbacks.
175 */
176static int
177bzip2_reader_init(struct archive_read_filter *self)
178{
179	static const size_t out_block_size = 64 * 1024;
180	void *out_block;
181	struct private_data *state;
182
183	self->code = ARCHIVE_COMPRESSION_BZIP2;
184	self->name = "bzip2";
185
186	state = (struct private_data *)calloc(sizeof(*state), 1);
187	out_block = (unsigned char *)malloc(out_block_size);
188	if (self == NULL || state == NULL || out_block == NULL) {
189		archive_set_error(&self->archive->archive, ENOMEM,
190		    "Can't allocate data for bzip2 decompression");
191		free(out_block);
192		free(state);
193		return (ARCHIVE_FATAL);
194	}
195
196	self->data = state;
197	state->out_block_size = out_block_size;
198	state->out_block = out_block;
199	self->read = bzip2_filter_read;
200	self->skip = NULL; /* not supported */
201	self->close = bzip2_filter_close;
202
203	return (ARCHIVE_OK);
204}
205
206/*
207 * Return the next block of decompressed data.
208 */
209static ssize_t
210bzip2_filter_read(struct archive_read_filter *self, const void **p)
211{
212	struct private_data *state;
213	size_t decompressed;
214	const char *read_buf;
215	ssize_t ret;
216
217	state = (struct private_data *)self->data;
218
219	if (state->eof) {
220		*p = NULL;
221		return (0);
222	}
223
224	/* Empty our output buffer. */
225	state->stream.next_out = state->out_block;
226	state->stream.avail_out = state->out_block_size;
227
228	/* Try to fill the output buffer. */
229	for (;;) {
230		if (!state->valid) {
231			if (bzip2_reader_bid(self->bidder, self->upstream) == 0) {
232				state->eof = 1;
233				*p = state->out_block;
234				decompressed = state->stream.next_out
235				    - state->out_block;
236				return (decompressed);
237			}
238			/* Initialize compression library. */
239			ret = BZ2_bzDecompressInit(&(state->stream),
240					   0 /* library verbosity */,
241					   0 /* don't use low-mem algorithm */);
242
243			/* If init fails, try low-memory algorithm instead. */
244			if (ret == BZ_MEM_ERROR)
245				ret = BZ2_bzDecompressInit(&(state->stream),
246					   0 /* library verbosity */,
247					   1 /* do use low-mem algo */);
248
249			if (ret != BZ_OK) {
250				const char *detail = NULL;
251				int err = ARCHIVE_ERRNO_MISC;
252				switch (ret) {
253				case BZ_PARAM_ERROR:
254					detail = "invalid setup parameter";
255					break;
256				case BZ_MEM_ERROR:
257					err = ENOMEM;
258					detail = "out of memory";
259					break;
260				case BZ_CONFIG_ERROR:
261					detail = "mis-compiled library";
262					break;
263				}
264				archive_set_error(&self->archive->archive, err,
265				    "Internal error initializing decompressor%s%s",
266				    detail == NULL ? "" : ": ",
267				    detail);
268				return (ARCHIVE_FATAL);
269			}
270			state->valid = 1;
271		}
272
273		/* stream.next_in is really const, but bzlib
274		 * doesn't declare it so. <sigh> */
275		read_buf =
276		    __archive_read_filter_ahead(self->upstream, 1, &ret);
277		if (read_buf == NULL)
278			return (ARCHIVE_FATAL);
279		state->stream.next_in = (char *)(uintptr_t)read_buf;
280		state->stream.avail_in = ret;
281		/* There is no more data, return whatever we have. */
282		if (ret == 0) {
283			state->eof = 1;
284			*p = state->out_block;
285			decompressed = state->stream.next_out
286			    - state->out_block;
287			return (decompressed);
288		}
289
290		/* Decompress as much as we can in one pass. */
291		ret = BZ2_bzDecompress(&(state->stream));
292		__archive_read_filter_consume(self->upstream,
293		    state->stream.next_in - read_buf);
294
295		switch (ret) {
296		case BZ_STREAM_END: /* Found end of stream. */
297			switch (BZ2_bzDecompressEnd(&(state->stream))) {
298			case BZ_OK:
299				break;
300			default:
301				archive_set_error(&(self->archive->archive),
302					  ARCHIVE_ERRNO_MISC,
303					  "Failed to clean up decompressor");
304				return (ARCHIVE_FATAL);
305			}
306			state->valid = 0;
307			/* FALLTHROUGH */
308		case BZ_OK: /* Decompressor made some progress. */
309			/* If we filled our buffer, update stats and return. */
310			if (state->stream.avail_out == 0) {
311				*p = state->out_block;
312				decompressed = state->stream.next_out
313				    - state->out_block;
314				return (decompressed);
315			}
316			break;
317		default: /* Return an error. */
318			archive_set_error(&self->archive->archive,
319			    ARCHIVE_ERRNO_MISC, "bzip decompression failed");
320			return (ARCHIVE_FATAL);
321		}
322	}
323}
324
325/*
326 * Clean up the decompressor.
327 */
328static int
329bzip2_filter_close(struct archive_read_filter *self)
330{
331	struct private_data *state;
332	int ret = ARCHIVE_OK;
333
334	state = (struct private_data *)self->data;
335
336	if (state->valid) {
337		switch (BZ2_bzDecompressEnd(&state->stream)) {
338		case BZ_OK:
339			break;
340		default:
341			archive_set_error(&self->archive->archive,
342					  ARCHIVE_ERRNO_MISC,
343					  "Failed to clean up decompressor");
344			ret = ARCHIVE_FATAL;
345		}
346	}
347
348	free(state->out_block);
349	free(state);
350	return (ret);
351}
352
353#endif /* HAVE_BZLIB_H && BZ_CONFIG_ERROR */
354