xref: /minix/usr.bin/gzip/unbzip2.c (revision 5a645f22)
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 
34 static off_t
unbzip2(int in,int out,char * pre,size_t prelen,off_t * bytes_in)35 unbzip2(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