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("$FreeBSD$");
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)
52 struct 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 */
61 static ssize_t	bzip2_filter_read(struct archive_read_filter *, const void **);
62 static 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  */
71 static int	bzip2_reader_bid(struct archive_read_filter_bidder *, struct archive_read_filter *);
72 static int	bzip2_reader_init(struct archive_read_filter *);
73 static int	bzip2_reader_free(struct archive_read_filter_bidder *);
74 
75 #if ARCHIVE_VERSION_NUMBER < 4000000
76 /* Deprecated; remove in libarchive 4.0 */
77 int
78 archive_read_support_compression_bzip2(struct archive *a)
79 {
80 	return archive_read_support_filter_bzip2(a);
81 }
82 #endif
83 
84 int
85 archive_read_support_filter_bzip2(struct archive *_a)
86 {
87 	struct archive_read *a = (struct archive_read *)_a;
88 	struct archive_read_filter_bidder *reader;
89 
90 	archive_check_magic(_a, ARCHIVE_READ_MAGIC,
91 	    ARCHIVE_STATE_NEW, "archive_read_support_filter_bzip2");
92 
93 	if (__archive_read_get_bidder(a, &reader) != ARCHIVE_OK)
94 		return (ARCHIVE_FATAL);
95 
96 	reader->data = NULL;
97 	reader->name = "bzip2";
98 	reader->bid = bzip2_reader_bid;
99 	reader->init = bzip2_reader_init;
100 	reader->options = NULL;
101 	reader->free = bzip2_reader_free;
102 #if defined(HAVE_BZLIB_H) && defined(BZ_CONFIG_ERROR)
103 	return (ARCHIVE_OK);
104 #else
105 	archive_set_error(_a, ARCHIVE_ERRNO_MISC,
106 	    "Using external bzip2 program");
107 	return (ARCHIVE_WARN);
108 #endif
109 }
110 
111 static int
112 bzip2_reader_free(struct archive_read_filter_bidder *self){
113 	(void)self; /* UNUSED */
114 	return (ARCHIVE_OK);
115 }
116 
117 /*
118  * Test whether we can handle this data.
119  *
120  * This logic returns zero if any part of the signature fails.  It
121  * also tries to Do The Right Thing if a very short buffer prevents us
122  * from verifying as much as we would like.
123  */
124 static int
125 bzip2_reader_bid(struct archive_read_filter_bidder *self, struct archive_read_filter *filter)
126 {
127 	const unsigned char *buffer;
128 	ssize_t avail;
129 	int bits_checked;
130 
131 	(void)self; /* UNUSED */
132 
133 	/* Minimal bzip2 archive is 14 bytes. */
134 	buffer = __archive_read_filter_ahead(filter, 14, &avail);
135 	if (buffer == NULL)
136 		return (0);
137 
138 	/* First three bytes must be "BZh" */
139 	bits_checked = 0;
140 	if (memcmp(buffer, "BZh", 3) != 0)
141 		return (0);
142 	bits_checked += 24;
143 
144 	/* Next follows a compression flag which must be an ASCII digit. */
145 	if (buffer[3] < '1' || buffer[3] > '9')
146 		return (0);
147 	bits_checked += 5;
148 
149 	/* After BZh[1-9], there must be either a data block
150 	 * which begins with 0x314159265359 or an end-of-data
151 	 * marker of 0x177245385090. */
152 	if (memcmp(buffer + 4, "\x31\x41\x59\x26\x53\x59", 6) == 0)
153 		bits_checked += 48;
154 	else if (memcmp(buffer + 4, "\x17\x72\x45\x38\x50\x90", 6) == 0)
155 		bits_checked += 48;
156 	else
157 		return (0);
158 
159 	return (bits_checked);
160 }
161 
162 #if !defined(HAVE_BZLIB_H) || !defined(BZ_CONFIG_ERROR)
163 
164 /*
165  * If we don't have the library on this system, we can't actually do the
166  * decompression.  We can, however, still detect compressed archives
167  * and emit a useful message.
168  */
169 static int
170 bzip2_reader_init(struct archive_read_filter *self)
171 {
172 	int r;
173 
174 	r = __archive_read_program(self, "bzip2 -d");
175 	/* Note: We set the format here even if __archive_read_program()
176 	 * above fails.  We do, after all, know what the format is
177 	 * even if we weren't able to read it. */
178 	self->code = ARCHIVE_FILTER_BZIP2;
179 	self->name = "bzip2";
180 	return (r);
181 }
182 
183 
184 #else
185 
186 /*
187  * Setup the callbacks.
188  */
189 static int
190 bzip2_reader_init(struct archive_read_filter *self)
191 {
192 	static const size_t out_block_size = 64 * 1024;
193 	void *out_block;
194 	struct private_data *state;
195 
196 	self->code = ARCHIVE_FILTER_BZIP2;
197 	self->name = "bzip2";
198 
199 	state = (struct private_data *)calloc(sizeof(*state), 1);
200 	out_block = (unsigned char *)malloc(out_block_size);
201 	if (state == NULL || out_block == NULL) {
202 		archive_set_error(&self->archive->archive, ENOMEM,
203 		    "Can't allocate data for bzip2 decompression");
204 		free(out_block);
205 		free(state);
206 		return (ARCHIVE_FATAL);
207 	}
208 
209 	self->data = state;
210 	state->out_block_size = out_block_size;
211 	state->out_block = out_block;
212 	self->read = bzip2_filter_read;
213 	self->skip = NULL; /* not supported */
214 	self->close = bzip2_filter_close;
215 
216 	return (ARCHIVE_OK);
217 }
218 
219 /*
220  * Return the next block of decompressed data.
221  */
222 static ssize_t
223 bzip2_filter_read(struct archive_read_filter *self, const void **p)
224 {
225 	struct private_data *state;
226 	size_t decompressed;
227 	const char *read_buf;
228 	ssize_t ret;
229 
230 	state = (struct private_data *)self->data;
231 
232 	if (state->eof) {
233 		*p = NULL;
234 		return (0);
235 	}
236 
237 	/* Empty our output buffer. */
238 	state->stream.next_out = state->out_block;
239 	state->stream.avail_out = state->out_block_size;
240 
241 	/* Try to fill the output buffer. */
242 	for (;;) {
243 		if (!state->valid) {
244 			if (bzip2_reader_bid(self->bidder, self->upstream) == 0) {
245 				state->eof = 1;
246 				*p = state->out_block;
247 				decompressed = state->stream.next_out
248 				    - state->out_block;
249 				return (decompressed);
250 			}
251 			/* Initialize compression library. */
252 			ret = BZ2_bzDecompressInit(&(state->stream),
253 					   0 /* library verbosity */,
254 					   0 /* don't use low-mem algorithm */);
255 
256 			/* If init fails, try low-memory algorithm instead. */
257 			if (ret == BZ_MEM_ERROR)
258 				ret = BZ2_bzDecompressInit(&(state->stream),
259 					   0 /* library verbosity */,
260 					   1 /* do use low-mem algo */);
261 
262 			if (ret != BZ_OK) {
263 				const char *detail = NULL;
264 				int err = ARCHIVE_ERRNO_MISC;
265 				switch (ret) {
266 				case BZ_PARAM_ERROR:
267 					detail = "invalid setup parameter";
268 					break;
269 				case BZ_MEM_ERROR:
270 					err = ENOMEM;
271 					detail = "out of memory";
272 					break;
273 				case BZ_CONFIG_ERROR:
274 					detail = "mis-compiled library";
275 					break;
276 				}
277 				archive_set_error(&self->archive->archive, err,
278 				    "Internal error initializing decompressor%s%s",
279 				    detail == NULL ? "" : ": ",
280 				    detail);
281 				return (ARCHIVE_FATAL);
282 			}
283 			state->valid = 1;
284 		}
285 
286 		/* stream.next_in is really const, but bzlib
287 		 * doesn't declare it so. <sigh> */
288 		read_buf =
289 		    __archive_read_filter_ahead(self->upstream, 1, &ret);
290 		if (read_buf == NULL) {
291 			archive_set_error(&self->archive->archive,
292 			    ARCHIVE_ERRNO_MISC,
293 			    "truncated bzip2 input");
294 			return (ARCHIVE_FATAL);
295 		}
296 		state->stream.next_in = (char *)(uintptr_t)read_buf;
297 		state->stream.avail_in = ret;
298 		/* There is no more data, return whatever we have. */
299 		if (ret == 0) {
300 			state->eof = 1;
301 			*p = state->out_block;
302 			decompressed = state->stream.next_out
303 			    - state->out_block;
304 			return (decompressed);
305 		}
306 
307 		/* Decompress as much as we can in one pass. */
308 		ret = BZ2_bzDecompress(&(state->stream));
309 		__archive_read_filter_consume(self->upstream,
310 		    state->stream.next_in - read_buf);
311 
312 		switch (ret) {
313 		case BZ_STREAM_END: /* Found end of stream. */
314 			switch (BZ2_bzDecompressEnd(&(state->stream))) {
315 			case BZ_OK:
316 				break;
317 			default:
318 				archive_set_error(&(self->archive->archive),
319 					  ARCHIVE_ERRNO_MISC,
320 					  "Failed to clean up decompressor");
321 				return (ARCHIVE_FATAL);
322 			}
323 			state->valid = 0;
324 			/* FALLTHROUGH */
325 		case BZ_OK: /* Decompressor made some progress. */
326 			/* If we filled our buffer, update stats and return. */
327 			if (state->stream.avail_out == 0) {
328 				*p = state->out_block;
329 				decompressed = state->stream.next_out
330 				    - state->out_block;
331 				return (decompressed);
332 			}
333 			break;
334 		default: /* Return an error. */
335 			archive_set_error(&self->archive->archive,
336 			    ARCHIVE_ERRNO_MISC, "bzip decompression failed");
337 			return (ARCHIVE_FATAL);
338 		}
339 	}
340 }
341 
342 /*
343  * Clean up the decompressor.
344  */
345 static int
346 bzip2_filter_close(struct archive_read_filter *self)
347 {
348 	struct private_data *state;
349 	int ret = ARCHIVE_OK;
350 
351 	state = (struct private_data *)self->data;
352 
353 	if (state->valid) {
354 		switch (BZ2_bzDecompressEnd(&state->stream)) {
355 		case BZ_OK:
356 			break;
357 		default:
358 			archive_set_error(&self->archive->archive,
359 					  ARCHIVE_ERRNO_MISC,
360 					  "Failed to clean up decompressor");
361 			ret = ARCHIVE_FATAL;
362 		}
363 		state->valid = 0;
364 	}
365 
366 	free(state->out_block);
367 	free(state);
368 	return (ret);
369 }
370 
371 #endif /* HAVE_BZLIB_H && BZ_CONFIG_ERROR */
372