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  * 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
  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 }