1 /* $NetBSD: unxz.c,v 1.6 2016/01/29 15:19:01 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 40 static off_t 41 unxz(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 } 154