unbzip2.c revision 1.13 
1/*	$NetBSD: unbzip2.c,v 1.13 2009/12/05 03:23:37 mrg Exp $	*/
2
3/*-
4 * Copyright (c) 2006 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Simon Burge.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/* This file is #included by gzip.c */
33
34static off_t
35unbzip2(int in, int out, char *pre, size_t prelen, off_t *bytes_in)
36{
37	int		ret, end_of_file, cold = 0;
38	off_t		bytes_out = 0;
39	bz_stream	bzs;
40	static char	*inbuf, *outbuf;
41
42	if (inbuf == NULL)
43		inbuf = malloc(BUFLEN);
44	if (outbuf == NULL)
45		outbuf = malloc(BUFLEN);
46	if (inbuf == NULL || outbuf == NULL)
47	        maybe_err("malloc");
48
49	bzs.bzalloc = NULL;
50	bzs.bzfree = NULL;
51	bzs.opaque = NULL;
52
53	end_of_file = 0;
54	ret = BZ2_bzDecompressInit(&bzs, 0, 0);
55	if (ret != BZ_OK)
56	        maybe_errx("bzip2 init");
57
58	/* Prepend. */
59	bzs.avail_in = prelen;
60	bzs.next_in = pre;
61
62	if (bytes_in)
63		*bytes_in = prelen;
64
65	while (ret == BZ_OK) {
66	        if (bzs.avail_in == 0 && !end_of_file) {
67			ssize_t	n;
68
69	                n = read(in, inbuf, BUFLEN);
70	                if (n < 0)
71	                        maybe_err("read");
72	                if (n == 0)
73	                        end_of_file = 1;
74	                bzs.next_in = inbuf;
75	                bzs.avail_in = n;
76			if (bytes_in)
77				*bytes_in += n;
78	        }
79
80	        bzs.next_out = outbuf;
81	        bzs.avail_out = BUFLEN;
82	        ret = BZ2_bzDecompress(&bzs);
83
84	        switch (ret) {
85	        case BZ_STREAM_END:
86	        case BZ_OK:
87	                if (ret == BZ_OK && end_of_file) {
88				/*
89				 * If we hit this after a stream end, consider
90				 * it as the end of the whole file and don't
91				 * bail out.
92				 */
93				if (cold == 1)
94					ret = BZ_STREAM_END;
95				else
96					maybe_errx("truncated file");
97			}
98			cold = 0;
99	                if (!tflag && bzs.avail_out != BUFLEN) {
100				ssize_t	n;
101
102	                        n = write(out, outbuf, BUFLEN - bzs.avail_out);
103	                        if (n < 0)
104	                                maybe_err("write");
105	                	bytes_out += n;
106	                }
107			if (ret == BZ_STREAM_END && !end_of_file) {
108				if (BZ2_bzDecompressEnd(&bzs) != BZ_OK ||
109				    BZ2_bzDecompressInit(&bzs, 0, 0) != BZ_OK)
110					maybe_errx("bzip2 re-init");
111				cold = 1;
112				ret = BZ_OK;
113			}
114			break;
115
116	        case BZ_DATA_ERROR:
117	                maybe_warnx("bzip2 data integrity error");
118			break;
119
120	        case BZ_DATA_ERROR_MAGIC:
121	                maybe_warnx("bzip2 magic number error");
122			break;
123
124	        case BZ_MEM_ERROR:
125	                maybe_warnx("bzip2 out of memory");
126			break;
127
128		default:
129			maybe_warnx("unknown bzip2 error: %d", ret);
130			break;
131	        }
132	}
133
134	if (ret != BZ_STREAM_END || BZ2_bzDecompressEnd(&bzs) != BZ_OK)
135	        return (-1);
136
137	return (bytes_out);
138}
139