2 * Copyright (c) 2003-2007 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 * 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.
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.
26 #include "archive_platform.h"
28 __FBSDID("$FreeBSD$");
48 #include "archive_private.h"
49 #include "archive_read_private.h"
55 unsigned char *out_block;
56 size_t out_block_size;
59 char eof; /* True = found end of compressed data. */
63 static ssize_t gzip_filter_read(struct archive_read_filter *, const void **);
64 static int gzip_filter_close(struct archive_read_filter *);
68 * Note that we can detect gzip archives even if we can't decompress
69 * them. (In fact, we like detecting them because we can give better
70 * error messages.) So the bid framework here gets compiled even
71 * if zlib is unavailable.
73 * TODO: If zlib is unavailable, gzip_bidder_init() should
74 * use the compress_program framework to try to fire up an external
77 static int gzip_bidder_bid(struct archive_read_filter_bidder *,
78 struct archive_read_filter *);
79 static int gzip_bidder_init(struct archive_read_filter *);
82 archive_read_support_compression_gzip(struct archive *_a)
84 struct archive_read *a = (struct archive_read *)_a;
85 struct archive_read_filter_bidder *bidder = __archive_read_get_bidder(a);
88 return (ARCHIVE_FATAL);
91 bidder->bid = gzip_bidder_bid;
92 bidder->init = gzip_bidder_init;
93 bidder->options = NULL;
94 bidder->free = NULL; /* No data, so no cleanup necessary. */
95 /* Signal the extent of gzip support with the return value here. */
99 archive_set_error(_a, ARCHIVE_ERRNO_MISC,
100 "Using external gunzip program");
101 return (ARCHIVE_WARN);
106 * Read and verify the header.
108 * Returns zero if the header couldn't be validated, else returns
109 * number of bytes in header. If pbits is non-NULL, it receives a
110 * count of bits verified, suitable for use by bidder.
113 peek_at_header(struct archive_read_filter *filter, int *pbits)
115 const unsigned char *p;
120 /* Start by looking at the first ten bytes of the header, which
121 * is all fixed layout. */
123 p = __archive_read_filter_ahead(filter, len, &avail);
124 if (p == NULL || avail == 0)
132 if (p[2] != 8) /* We only support deflation. */
135 if ((p[3] & 0xE0)!= 0) /* No reserved flags set. */
139 /* Bytes 4-7 are mod time. */
140 /* Byte 8 is deflate flags. */
141 /* XXXX TODO: return deflate flags back to consume_header for use
142 in initializing the decompressor. */
145 /* Optional extra data: 2 byte length plus variable body. */
146 if (header_flags & 4) {
147 p = __archive_read_filter_ahead(filter, len + 2, &avail);
150 len += ((int)p[len + 1] << 8) | (int)p[len];
154 /* Null-terminated optional filename. */
155 if (header_flags & 8) {
159 p = __archive_read_filter_ahead(filter,
163 } while (p[len - 1] != 0);
166 /* Null-terminated optional comment. */
167 if (header_flags & 16) {
171 p = __archive_read_filter_ahead(filter,
175 } while (p[len - 1] != 0);
178 /* Optional header CRC */
179 if ((header_flags & 2)) {
180 p = __archive_read_filter_ahead(filter, len + 2, &avail);
184 int hcrc = ((int)p[len + 1] << 8) | (int)p[len];
185 int crc = /* XXX TODO: Compute header CRC. */;
199 * Bidder just verifies the header and returns the number of verified bits.
202 gzip_bidder_bid(struct archive_read_filter_bidder *self,
203 struct archive_read_filter *filter)
207 (void)self; /* UNUSED */
209 if (peek_at_header(filter, &bits_checked))
210 return (bits_checked);
218 * If we don't have the library on this system, we can't do the
219 * decompression directly. We can, however, try to run gunzip
220 * in case that's available.
223 gzip_bidder_init(struct archive_read_filter *self)
227 r = __archive_read_program(self, "gunzip");
228 /* Note: We set the format here even if __archive_read_program()
229 * above fails. We do, after all, know what the format is
230 * even if we weren't able to read it. */
231 self->code = ARCHIVE_COMPRESSION_GZIP;
239 * Initialize the filter object.
242 gzip_bidder_init(struct archive_read_filter *self)
244 struct private_data *state;
245 static const size_t out_block_size = 64 * 1024;
248 self->code = ARCHIVE_COMPRESSION_GZIP;
251 state = (struct private_data *)calloc(sizeof(*state), 1);
252 out_block = (unsigned char *)malloc(out_block_size);
253 if (state == NULL || out_block == NULL) {
256 archive_set_error(&self->archive->archive, ENOMEM,
257 "Can't allocate data for gzip decompression");
258 return (ARCHIVE_FATAL);
262 state->out_block_size = out_block_size;
263 state->out_block = out_block;
264 self->read = gzip_filter_read;
265 self->skip = NULL; /* not supported */
266 self->close = gzip_filter_close;
268 state->in_stream = 0; /* We're not actually within a stream yet. */
274 consume_header(struct archive_read_filter *self)
276 struct private_data *state;
281 state = (struct private_data *)self->data;
283 /* If this is a real header, consume it. */
284 len = peek_at_header(self->upstream, NULL);
286 return (ARCHIVE_EOF);
287 __archive_read_filter_consume(self->upstream, len);
289 /* Initialize CRC accumulator. */
290 state->crc = crc32(0L, NULL, 0);
292 /* Initialize compression library. */
293 state->stream.next_in = (unsigned char *)(uintptr_t)
294 __archive_read_filter_ahead(self->upstream, 1, &avail);
295 state->stream.avail_in = avail;
296 ret = inflateInit2(&(state->stream),
297 -15 /* Don't check for zlib header */);
299 /* Decipher the error code. */
302 state->in_stream = 1;
305 archive_set_error(&self->archive->archive,
307 "Internal error initializing compression library: "
308 "invalid setup parameter");
311 archive_set_error(&self->archive->archive, ENOMEM,
312 "Internal error initializing compression library: "
315 case Z_VERSION_ERROR:
316 archive_set_error(&self->archive->archive,
318 "Internal error initializing compression library: "
319 "invalid library version");
322 archive_set_error(&self->archive->archive,
324 "Internal error initializing compression library: "
325 " Zlib error %d", ret);
328 return (ARCHIVE_FATAL);
332 consume_trailer(struct archive_read_filter *self)
334 struct private_data *state;
335 const unsigned char *p;
338 state = (struct private_data *)self->data;
340 state->in_stream = 0;
341 switch (inflateEnd(&(state->stream))) {
345 archive_set_error(&self->archive->archive,
347 "Failed to clean up gzip decompressor");
348 return (ARCHIVE_FATAL);
351 /* GZip trailer is a fixed 8 byte structure. */
352 p = __archive_read_filter_ahead(self->upstream, 8, &avail);
353 if (p == NULL || avail == 0)
354 return (ARCHIVE_FATAL);
356 /* XXX TODO: Verify the length and CRC. */
358 /* We've verified the trailer, so consume it now. */
359 __archive_read_filter_consume(self->upstream, 8);
365 gzip_filter_read(struct archive_read_filter *self, const void **p)
367 struct private_data *state;
372 state = (struct private_data *)self->data;
374 /* Empty our output buffer. */
375 state->stream.next_out = state->out_block;
376 state->stream.avail_out = state->out_block_size;
378 /* Try to fill the output buffer. */
379 while (state->stream.avail_out > 0 && !state->eof) {
380 /* If we're not in a stream, read a header
381 * and initialize the decompression library. */
382 if (!state->in_stream) {
383 ret = consume_header(self);
384 if (ret == ARCHIVE_EOF) {
388 if (ret < ARCHIVE_OK)
392 /* Peek at the next available data. */
393 /* ZLib treats stream.next_in as const but doesn't declare
394 * it so, hence this ugly cast. */
395 state->stream.next_in = (unsigned char *)(uintptr_t)
396 __archive_read_filter_ahead(self->upstream, 1, &avail_in);
397 if (state->stream.next_in == NULL)
398 return (ARCHIVE_FATAL);
399 state->stream.avail_in = avail_in;
401 /* Decompress and consume some of that data. */
402 ret = inflate(&(state->stream), 0);
404 case Z_OK: /* Decompressor made some progress. */
405 __archive_read_filter_consume(self->upstream,
406 avail_in - state->stream.avail_in);
408 case Z_STREAM_END: /* Found end of stream. */
409 __archive_read_filter_consume(self->upstream,
410 avail_in - state->stream.avail_in);
411 /* Consume the stream trailer; release the
412 * decompression library. */
413 ret = consume_trailer(self);
416 /* Return an error. */
417 archive_set_error(&self->archive->archive,
419 "gzip decompression failed");
420 return (ARCHIVE_FATAL);
424 /* We've read as much as we can. */
425 decompressed = state->stream.next_out - state->out_block;
426 state->total_out += decompressed;
427 if (decompressed == 0)
430 *p = state->out_block;
431 return (decompressed);
435 * Clean up the decompressor.
438 gzip_filter_close(struct archive_read_filter *self)
440 struct private_data *state;
443 state = (struct private_data *)self->data;
446 if (state->in_stream) {
447 switch (inflateEnd(&(state->stream))) {
451 archive_set_error(&(self->archive->archive),
453 "Failed to clean up gzip compressor");
458 free(state->out_block);
463 #endif /* HAVE_ZLIB_H */