1 /* $NetBSD: unxz.c,v 1.5 2011/09/30 01:32:21 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2011 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38 #include <sys/cdefs.h>
39 __RCSID("$NetBSD: unxz.c,v 1.5 2011/09/30 01:32:21 christos Exp $");
40
41 #include <stdarg.h>
42 #include <errno.h>
43 #include <stdio.h>
44 #include <unistd.h>
45 #include <lzma.h>
46
47 static off_t
unxz(int i,int o,char * pre,size_t prelen,off_t * bytes_in)48 unxz(int i, int o, char *pre, size_t prelen, off_t *bytes_in)
49 {
50 lzma_stream strm = LZMA_STREAM_INIT;
51 static const int flags = LZMA_TELL_UNSUPPORTED_CHECK|LZMA_CONCATENATED;
52 lzma_ret ret;
53 lzma_action action = LZMA_RUN;
54 off_t bytes_out, bp;
55 uint8_t ibuf[BUFSIZ];
56 uint8_t obuf[BUFSIZ];
57
58 if (bytes_in == NULL)
59 bytes_in = &bp;
60
61 strm.next_in = ibuf;
62 memcpy(ibuf, pre, prelen);
63 strm.avail_in = read(i, ibuf + prelen, sizeof(ibuf) - prelen);
64 if (strm.avail_in == (size_t)-1)
65 maybe_err("read failed");
66 strm.avail_in += prelen;
67 *bytes_in = strm.avail_in;
68
69 if ((ret = lzma_stream_decoder(&strm, UINT64_MAX, flags)) != LZMA_OK)
70 maybe_errx("Can't initialize decoder (%d)", ret);
71
72 strm.next_out = NULL;
73 strm.avail_out = 0;
74 if ((ret = lzma_code(&strm, LZMA_RUN)) != LZMA_OK)
75 maybe_errx("Can't read headers (%d)", ret);
76
77 bytes_out = 0;
78 strm.next_out = obuf;
79 strm.avail_out = sizeof(obuf);
80
81 for (;;) {
82 if (strm.avail_in == 0) {
83 strm.next_in = ibuf;
84 strm.avail_in = read(i, ibuf, sizeof(ibuf));
85 switch (strm.avail_in) {
86 case (size_t)-1:
87 maybe_err("read failed");
88 /*NOTREACHED*/
89 case 0:
90 action = LZMA_FINISH;
91 break;
92 default:
93 *bytes_in += strm.avail_in;
94 break;
95 }
96 }
97
98 ret = lzma_code(&strm, action);
99
100 // Write and check write error before checking decoder error.
101 // This way as much data as possible gets written to output
102 // even if decoder detected an error.
103 if (strm.avail_out == 0 || ret != LZMA_OK) {
104 const size_t write_size = sizeof(obuf) - strm.avail_out;
105
106 if (write(o, obuf, write_size) != (ssize_t)write_size)
107 maybe_err("write failed");
108
109 strm.next_out = obuf;
110 strm.avail_out = sizeof(obuf);
111 bytes_out += write_size;
112 }
113
114 if (ret != LZMA_OK) {
115 if (ret == LZMA_STREAM_END) {
116 // Check that there's no trailing garbage.
117 if (strm.avail_in != 0 || read(i, ibuf, 1))
118 ret = LZMA_DATA_ERROR;
119 else {
120 lzma_end(&strm);
121 return bytes_out;
122 }
123 }
124
125 const char *msg;
126 switch (ret) {
127 case LZMA_MEM_ERROR:
128 msg = strerror(ENOMEM);
129 break;
130
131 case LZMA_FORMAT_ERROR:
132 msg = "File format not recognized";
133 break;
134
135 case LZMA_OPTIONS_ERROR:
136 // FIXME: Better message?
137 msg = "Unsupported compression options";
138 break;
139
140 case LZMA_DATA_ERROR:
141 msg = "File is corrupt";
142 break;
143
144 case LZMA_BUF_ERROR:
145 msg = "Unexpected end of input";
146 break;
147
148 case LZMA_MEMLIMIT_ERROR:
149 msg = "Reached memory limit";
150 break;
151
152 default:
153 maybe_errx("Unknown error (%d)", ret);
154 break;
155 }
156 maybe_errx("%s", msg);
157
158 }
159 }
160 }
161