/usr.bin/gzip/unxz.c

  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 *
 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#include <sys/cdefs.h>
 32__FBSDID("$FreeBSD$");
 33
 34#include <stdarg.h>
 35#include <errno.h>
 36#include <stdio.h>
 37#include <unistd.h>
 38#include <lzma.h>
 39
 40static off_t
 41unxz(int i, int o, char *pre, size_t prelen, off_t *bytes_in)
 42{
 43	lzma_stream strm = LZMA_STREAM_INIT;
 44	static const int flags = LZMA_TELL_UNSUPPORTED_CHECK|LZMA_CONCATENATED;
 45	lzma_ret ret;
 46	lzma_action action = LZMA_RUN;
 47	off_t bytes_out, bp;
 48	uint8_t ibuf[BUFSIZ];
 49	uint8_t obuf[BUFSIZ];
 50
 51	if (bytes_in == NULL)
 52		bytes_in = &bp;
 53
 54	strm.next_in = ibuf;
 55	memcpy(ibuf, pre, prelen);
 56	strm.avail_in = read(i, ibuf + prelen, sizeof(ibuf) - prelen);
 57	if (strm.avail_in == (size_t)-1)
 58		maybe_err("read failed");
 59	strm.avail_in += prelen;
 60	*bytes_in = strm.avail_in;
 61
 62	if ((ret = lzma_stream_decoder(&strm, UINT64_MAX, flags)) != LZMA_OK)
 63		maybe_errx("Can't initialize decoder (%d)", ret);
 64
 65	strm.next_out = NULL;
 66	strm.avail_out = 0;
 67	if ((ret = lzma_code(&strm, LZMA_RUN)) != LZMA_OK)
 68		maybe_errx("Can't read headers (%d)", ret);
 69
 70	bytes_out = 0;
 71	strm.next_out = obuf;
 72	strm.avail_out = sizeof(obuf);
 73
 74	for (;;) {
 75		if (strm.avail_in == 0) {
 76			strm.next_in = ibuf;
 77			strm.avail_in = read(i, ibuf, sizeof(ibuf));
 78			switch (strm.avail_in) {
 79			case (size_t)-1:
 80				maybe_err("read failed");
 81				/*NOTREACHED*/
 82			case 0:
 83				action = LZMA_FINISH;
 84				break;
 85			default:
 86				*bytes_in += strm.avail_in;
 87				break;
 88			}
 89		}
 90
 91		ret = lzma_code(&strm, action);
 92
 93		// Write and check write error before checking decoder error.
 94		// This way as much data as possible gets written to output
 95		// even if decoder detected an error.
 96		if (strm.avail_out == 0 || ret != LZMA_OK) {
 97			const size_t write_size = sizeof(obuf) - strm.avail_out;
 98
 99			if (write(o, obuf, write_size) != (ssize_t)write_size)
100				maybe_err("write failed");
101
102			strm.next_out = obuf;
103			strm.avail_out = sizeof(obuf);
104			bytes_out += write_size;
105		}
106
107		if (ret != LZMA_OK) {
108			if (ret == LZMA_STREAM_END) {
109				// Check that there's no trailing garbage.
110				if (strm.avail_in != 0 || read(i, ibuf, 1))
111					ret = LZMA_DATA_ERROR;
112				else {
113					lzma_end(&strm);
114					return bytes_out;
115				}
116			}
117
118			const char *msg;
119			switch (ret) {
120			case LZMA_MEM_ERROR:
121				msg = strerror(ENOMEM);
122				break;
123
124			case LZMA_FORMAT_ERROR:
125				msg = "File format not recognized";
126				break;
127
128			case LZMA_OPTIONS_ERROR:
129				// FIXME: Better message?
130				msg = "Unsupported compression options";
131				break;
132
133			case LZMA_DATA_ERROR:
134				msg = "File is corrupt";
135				break;
136
137			case LZMA_BUF_ERROR:
138				msg = "Unexpected end of input";
139				break;
140
141			case LZMA_MEMLIMIT_ERROR:
142				msg = "Reached memory limit";
143				break;
144
145			default:
146				maybe_errx("Unknown error (%d)", ret);
147				break;
148			}
149			maybe_errx("%s", msg);
150
151		}
152	}
153}