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: src/usr.bin/gzip/unxz.c,v 1.2 2011/10/16 07:35:26 delphij Exp $");
  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 }