archive_write_add_filter_gzip.c revision 231200 
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: head/lib/libarchive/archive_write_set_compression_gzip.c 201081 2009-12-28 02:04:42Z kientzle $");
29
30#ifdef HAVE_ERRNO_H
31#include <errno.h>
32#endif
33#ifdef HAVE_STDLIB_H
34#include <stdlib.h>
35#endif
36#ifdef HAVE_STRING_H
37#include <string.h>
38#endif
39#include <time.h>
40#ifdef HAVE_ZLIB_H
41#include <zlib.h>
42#endif
43
44#include "archive.h"
45#include "archive_private.h"
46#include "archive_write_private.h"
47
48#if ARCHIVE_VERSION_NUMBER < 4000000
49int
50archive_write_set_compression_gzip(struct archive *a)
51{
52	__archive_write_filters_free(a);
53	return (archive_write_add_filter_gzip(a));
54}
55#endif
56
57#ifndef HAVE_ZLIB_H
58int
59archive_write_add_filter_gzip(struct archive *a)
60{
61	archive_set_error(a, ARCHIVE_ERRNO_MISC,
62	    "gzip compression not supported on this platform");
63	return (ARCHIVE_FATAL);
64}
65#else
66/* Don't compile this if we don't have zlib. */
67
68struct private_data {
69	int		 compression_level;
70	z_stream	 stream;
71	int64_t		 total_in;
72	unsigned char	*compressed;
73	size_t		 compressed_buffer_size;
74	unsigned long	 crc;
75};
76
77/*
78 * Yuck.  zlib.h is not const-correct, so I need this one bit
79 * of ugly hackery to convert a const * pointer to a non-const pointer.
80 */
81#define	SET_NEXT_IN(st,src)					\
82	(st)->stream.next_in = (Bytef *)(uintptr_t)(const void *)(src)
83
84static int archive_compressor_gzip_options(struct archive_write_filter *,
85		    const char *, const char *);
86static int archive_compressor_gzip_open(struct archive_write_filter *);
87static int archive_compressor_gzip_write(struct archive_write_filter *,
88		    const void *, size_t);
89static int archive_compressor_gzip_close(struct archive_write_filter *);
90static int archive_compressor_gzip_free(struct archive_write_filter *);
91static int drive_compressor(struct archive_write_filter *,
92		    struct private_data *, int finishing);
93
94
95/*
96 * Add a gzip compression filter to this write handle.
97 */
98int
99archive_write_add_filter_gzip(struct archive *_a)
100{
101	struct archive_write *a = (struct archive_write *)_a;
102	struct archive_write_filter *f = __archive_write_allocate_filter(_a);
103	struct private_data *data;
104	archive_check_magic(&a->archive, ARCHIVE_WRITE_MAGIC,
105	    ARCHIVE_STATE_NEW, "archive_write_add_filter_gzip");
106
107	data = calloc(1, sizeof(*data));
108	if (data == NULL) {
109		archive_set_error(&a->archive, ENOMEM, "Out of memory");
110		return (ARCHIVE_FATAL);
111	}
112	f->data = data;
113	data->compression_level = Z_DEFAULT_COMPRESSION;
114	f->open = &archive_compressor_gzip_open;
115	f->options = &archive_compressor_gzip_options;
116	f->close = &archive_compressor_gzip_close;
117	f->free = &archive_compressor_gzip_free;
118	f->code = ARCHIVE_COMPRESSION_GZIP;
119	f->name = "gzip";
120	return (ARCHIVE_OK);
121}
122
123/*
124 * Setup callback.
125 */
126static int
127archive_compressor_gzip_open(struct archive_write_filter *f)
128{
129	struct private_data *data = (struct private_data *)f->data;
130	int ret;
131	time_t t;
132
133	ret = __archive_write_open_filter(f->next_filter);
134	if (ret != ARCHIVE_OK)
135		return (ret);
136
137	if (data->compressed == NULL) {
138		data->compressed_buffer_size = 65536;
139		data->compressed
140		    = (unsigned char *)malloc(data->compressed_buffer_size);
141		if (data->compressed == NULL) {
142			archive_set_error(f->archive, ENOMEM,
143			    "Can't allocate data for compression buffer");
144			return (ARCHIVE_FATAL);
145		}
146	}
147
148	data->crc = crc32(0L, NULL, 0);
149	data->stream.next_out = data->compressed;
150	data->stream.avail_out = data->compressed_buffer_size;
151
152	/* Prime output buffer with a gzip header. */
153	t = time(NULL);
154	data->compressed[0] = 0x1f; /* GZip signature bytes */
155	data->compressed[1] = 0x8b;
156	data->compressed[2] = 0x08; /* "Deflate" compression */
157	data->compressed[3] = 0; /* No options */
158	data->compressed[4] = (t)&0xff;  /* Timestamp */
159	data->compressed[5] = (t>>8)&0xff;
160	data->compressed[6] = (t>>16)&0xff;
161	data->compressed[7] = (t>>24)&0xff;
162	data->compressed[8] = 0; /* No deflate options */
163	data->compressed[9] = 3; /* OS=Unix */
164	data->stream.next_out += 10;
165	data->stream.avail_out -= 10;
166
167	f->write = archive_compressor_gzip_write;
168
169	/* Initialize compression library. */
170	ret = deflateInit2(&(data->stream),
171	    data->compression_level,
172	    Z_DEFLATED,
173	    -15 /* < 0 to suppress zlib header */,
174	    8,
175	    Z_DEFAULT_STRATEGY);
176
177	if (ret == Z_OK) {
178		f->data = data;
179		return (ARCHIVE_OK);
180	}
181
182	/* Library setup failed: clean up. */
183	archive_set_error(f->archive, ARCHIVE_ERRNO_MISC, "Internal error "
184	    "initializing compression library");
185
186	/* Override the error message if we know what really went wrong. */
187	switch (ret) {
188	case Z_STREAM_ERROR:
189		archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,
190		    "Internal error initializing "
191		    "compression library: invalid setup parameter");
192		break;
193	case Z_MEM_ERROR:
194		archive_set_error(f->archive, ENOMEM, "Internal error initializing "
195		    "compression library");
196		break;
197	case Z_VERSION_ERROR:
198		archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,
199		    "Internal error initializing "
200		    "compression library: invalid library version");
201		break;
202	}
203
204	return (ARCHIVE_FATAL);
205}
206
207/*
208 * Set write options.
209 */
210static int
211archive_compressor_gzip_options(struct archive_write_filter *f, const char *key,
212    const char *value)
213{
214	struct private_data *data = (struct private_data *)f->data;
215
216	if (strcmp(key, "compression-level") == 0) {
217		if (value == NULL || !(value[0] >= '0' && value[0] <= '9') ||
218		    value[1] != '\0')
219			return (ARCHIVE_WARN);
220		data->compression_level = value[0] - '0';
221		return (ARCHIVE_OK);
222	}
223	return (ARCHIVE_WARN);
224}
225
226/*
227 * Write data to the compressed stream.
228 */
229static int
230archive_compressor_gzip_write(struct archive_write_filter *f, const void *buff,
231    size_t length)
232{
233	struct private_data *data = (struct private_data *)f->data;
234	int ret;
235
236	/* Update statistics */
237	data->crc = crc32(data->crc, (const Bytef *)buff, length);
238	data->total_in += length;
239
240	/* Compress input data to output buffer */
241	SET_NEXT_IN(data, buff);
242	data->stream.avail_in = length;
243	if ((ret = drive_compressor(f, data, 0)) != ARCHIVE_OK)
244		return (ret);
245
246	return (ARCHIVE_OK);
247}
248
249/*
250 * Finish the compression...
251 */
252static int
253archive_compressor_gzip_close(struct archive_write_filter *f)
254{
255	unsigned char trailer[8];
256	struct private_data *data = (struct private_data *)f->data;
257	int ret, r1;
258
259	/* Finish compression cycle */
260	ret = drive_compressor(f, data, 1);
261	if (ret == ARCHIVE_OK) {
262		/* Write the last compressed data. */
263		ret = __archive_write_filter(f->next_filter,
264		    data->compressed,
265		    data->compressed_buffer_size - data->stream.avail_out);
266	}
267	if (ret == ARCHIVE_OK) {
268		/* Build and write out 8-byte trailer. */
269		trailer[0] = (data->crc)&0xff;
270		trailer[1] = (data->crc >> 8)&0xff;
271		trailer[2] = (data->crc >> 16)&0xff;
272		trailer[3] = (data->crc >> 24)&0xff;
273		trailer[4] = (data->total_in)&0xff;
274		trailer[5] = (data->total_in >> 8)&0xff;
275		trailer[6] = (data->total_in >> 16)&0xff;
276		trailer[7] = (data->total_in >> 24)&0xff;
277		ret = __archive_write_filter(f->next_filter, trailer, 8);
278	}
279
280	switch (deflateEnd(&(data->stream))) {
281	case Z_OK:
282		break;
283	default:
284		archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,
285		    "Failed to clean up compressor");
286		ret = ARCHIVE_FATAL;
287	}
288	r1 = __archive_write_close_filter(f->next_filter);
289	return (r1 < ret ? r1 : ret);
290}
291
292static int
293archive_compressor_gzip_free(struct archive_write_filter *f)
294{
295	struct private_data *data = (struct private_data *)f->data;
296	free(data->compressed);
297	free(data);
298	f->data = NULL;
299	return (ARCHIVE_OK);
300}
301
302/*
303 * Utility function to push input data through compressor,
304 * writing full output blocks as necessary.
305 *
306 * Note that this handles both the regular write case (finishing ==
307 * false) and the end-of-archive case (finishing == true).
308 */
309static int
310drive_compressor(struct archive_write_filter *f,
311    struct private_data *data, int finishing)
312{
313	int ret;
314
315	for (;;) {
316		if (data->stream.avail_out == 0) {
317			ret = __archive_write_filter(f->next_filter,
318			    data->compressed,
319			    data->compressed_buffer_size);
320			if (ret != ARCHIVE_OK)
321				return (ARCHIVE_FATAL);
322			data->stream.next_out = data->compressed;
323			data->stream.avail_out = data->compressed_buffer_size;
324		}
325
326		/* If there's nothing to do, we're done. */
327		if (!finishing && data->stream.avail_in == 0)
328			return (ARCHIVE_OK);
329
330		ret = deflate(&(data->stream),
331		    finishing ? Z_FINISH : Z_NO_FLUSH );
332
333		switch (ret) {
334		case Z_OK:
335			/* In non-finishing case, check if compressor
336			 * consumed everything */
337			if (!finishing && data->stream.avail_in == 0)
338				return (ARCHIVE_OK);
339			/* In finishing case, this return always means
340			 * there's more work */
341			break;
342		case Z_STREAM_END:
343			/* This return can only occur in finishing case. */
344			return (ARCHIVE_OK);
345		default:
346			/* Any other return value indicates an error. */
347			archive_set_error(f->archive, ARCHIVE_ERRNO_MISC,
348			    "GZip compression failed:"
349			    " deflate() call returned status %d",
350			    ret);
351			return (ARCHIVE_FATAL);
352		}
353	}
354}
355
356#endif /* HAVE_ZLIB_H */
357