usr.bin/gzip/unxz.c

   1 /*      $NetBSD: unxz.c,v 1.7 2017/08/04 07:27:08 mrg Exp $     */
   2
   3 /*-
   4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
   5  *
   6  * Copyright (c) 2011 The NetBSD Foundation, Inc.
   7  * All rights reserved.
   8  *
   9  * This code is derived from software contributed to The NetBSD Foundation
  10  * by Christos Zoulas.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include <stdarg.h>
  37 #include <errno.h>
  38 #include <stdio.h>
  39 #include <unistd.h>
  40 #include <lzma.h>
  41
  42 static off_t
  43 unxz(int i, int o, char *pre, size_t prelen, off_t *bytes_in)
  44 {
  45         lzma_stream strm = LZMA_STREAM_INIT;
  46         static const int flags = LZMA_TELL_UNSUPPORTED_CHECK|LZMA_CONCATENATED;
  47         lzma_ret ret;
  48         lzma_action action = LZMA_RUN;
  49         off_t bytes_out, bp;
  50         uint8_t ibuf[BUFSIZ];
  51         uint8_t obuf[BUFSIZ];
  52
  53         if (bytes_in == NULL)
  54                 bytes_in = &bp;
  55
  56         strm.next_in = ibuf;
  57         memcpy(ibuf, pre, prelen);
  58         strm.avail_in = read(i, ibuf + prelen, sizeof(ibuf) - prelen);
  59         if (strm.avail_in == (size_t)-1)
  60                 maybe_err("read failed");
  61         infile_newdata(strm.avail_in);
  62         strm.avail_in += prelen;
  63         *bytes_in = strm.avail_in;
  64
  65         if ((ret = lzma_stream_decoder(&strm, UINT64_MAX, flags)) != LZMA_OK)
  66                 maybe_errx("Can't initialize decoder (%d)", ret);
  67
  68         strm.next_out = NULL;
  69         strm.avail_out = 0;
  70         if ((ret = lzma_code(&strm, LZMA_RUN)) != LZMA_OK)
  71                 maybe_errx("Can't read headers (%d)", ret);
  72
  73         bytes_out = 0;
  74         strm.next_out = obuf;
  75         strm.avail_out = sizeof(obuf);
  76
  77         for (;;) {
  78                 check_siginfo();
  79                 if (strm.avail_in == 0) {
  80                         strm.next_in = ibuf;
  81                         strm.avail_in = read(i, ibuf, sizeof(ibuf));
  82                         switch (strm.avail_in) {
  83                         case (size_t)-1:
  84                                 maybe_err("read failed");
  85                                 /*NOTREACHED*/
  86                         case 0:
  87                                 action = LZMA_FINISH;
  88                                 break;
  89                         default:
  90                                 infile_newdata(strm.avail_in);
  91                                 *bytes_in += strm.avail_in;
  92                                 break;
  93                         }
  94                 }
  95
  96                 ret = lzma_code(&strm, action);
  97
  98                 // Write and check write error before checking decoder error.
  99                 // This way as much data as possible gets written to output
 100                 // even if decoder detected an error.
 101                 if (strm.avail_out == 0 || ret != LZMA_OK) {
 102                         const size_t write_size = sizeof(obuf) - strm.avail_out;
 103
 104                         if (write(o, obuf, write_size) != (ssize_t)write_size)
 105                                 maybe_err("write failed");
 106
 107                         strm.next_out = obuf;
 108                         strm.avail_out = sizeof(obuf);
 109                         bytes_out += write_size;
 110                 }
 111
 112                 if (ret != LZMA_OK) {
 113                         if (ret == LZMA_STREAM_END) {
 114                                 // Check that there's no trailing garbage.
 115                                 if (strm.avail_in != 0 || read(i, ibuf, 1))
 116                                         ret = LZMA_DATA_ERROR;
 117                                 else {
 118                                         lzma_end(&strm);
 119                                         return bytes_out;
 120                                 }
 121                         }
 122
 123                         const char *msg;
 124                         switch (ret) {
 125                         case LZMA_MEM_ERROR:
 126                                 msg = strerror(ENOMEM);
 127                                 break;
 128
 129                         case LZMA_FORMAT_ERROR:
 130                                 msg = "File format not recognized";
 131                                 break;
 132
 133                         case LZMA_OPTIONS_ERROR:
 134                                 // FIXME: Better message?
 135                                 msg = "Unsupported compression options";
 136                                 break;
 137
 138                         case LZMA_DATA_ERROR:
 139                                 msg = "File is corrupt";
 140                                 break;
 141
 142                         case LZMA_BUF_ERROR:
 143                                 msg = "Unexpected end of input";
 144                                 break;
 145
 146                         case LZMA_MEMLIMIT_ERROR:
 147                                 msg = "Reached memory limit";
 148                                 break;
 149
 150                         default:
 151                                 maybe_errx("Unknown error (%d)", ret);
 152                                 break;
 153                         }
 154                         maybe_errx("%s", msg);
 155
 156                 }
 157         }
 158 }