/*      $NetBSD: unbzip2.c,v 1.14 2017/08/04 07:27:08 mrg Exp $ */

/*-
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Simon Burge.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/* This file is #included by gzip.c */

static off_t
unbzip2(int in, int out, char *pre, size_t prelen, off_t *bytes_in)
{
       int             ret, end_of_file, cold = 0;
       off_t           bytes_out = 0;
       bz_stream       bzs;
       static char     *inbuf, *outbuf;

       if (inbuf == NULL)
               inbuf = malloc(BUFLEN);
       if (outbuf == NULL)
               outbuf = malloc(BUFLEN);
       if (inbuf == NULL || outbuf == NULL)
               maybe_err("malloc");

       bzs.bzalloc = NULL;
       bzs.bzfree = NULL;
       bzs.opaque = NULL;

       end_of_file = 0;
       ret = BZ2_bzDecompressInit(&bzs, 0, 0);
       if (ret != BZ_OK)
               maybe_errx("bzip2 init");

       /* Prepend. */
       bzs.avail_in = prelen;
       bzs.next_in = pre;

       if (bytes_in)
               *bytes_in = prelen;

       while (ret == BZ_OK) {
               check_siginfo();
               if (bzs.avail_in == 0 && !end_of_file) {
                       ssize_t n;

                       n = read(in, inbuf, BUFLEN);
                       if (n < 0)
                               maybe_err("read");
                       if (n == 0)
                               end_of_file = 1;
                       infile_newdata(n);
                       bzs.next_in = inbuf;
                       bzs.avail_in = n;
                       if (bytes_in)
                               *bytes_in += n;
               }

               bzs.next_out = outbuf;
               bzs.avail_out = BUFLEN;
               ret = BZ2_bzDecompress(&bzs);

               switch (ret) {
               case BZ_STREAM_END:
               case BZ_OK:
                       if (ret == BZ_OK && end_of_file) {
                               /*
                                * If we hit this after a stream end, consider
                                * it as the end of the whole file and don't
                                * bail out.
                                */
                               if (cold == 1)
                                       ret = BZ_STREAM_END;
                               else
                                       maybe_errx("truncated file");
                       }
                       cold = 0;
                       if (!tflag && bzs.avail_out != BUFLEN) {
                               ssize_t n;

                               n = write(out, outbuf, BUFLEN - bzs.avail_out);
                               if (n < 0)
                                       maybe_err("write");
                               bytes_out += n;
                       }
                       if (ret == BZ_STREAM_END && !end_of_file) {
                               if (BZ2_bzDecompressEnd(&bzs) != BZ_OK ||
                                   BZ2_bzDecompressInit(&bzs, 0, 0) != BZ_OK)
                                       maybe_errx("bzip2 re-init");
                               cold = 1;
                               ret = BZ_OK;
                       }
                       break;

               case BZ_DATA_ERROR:
                       maybe_warnx("bzip2 data integrity error");
                       break;

               case BZ_DATA_ERROR_MAGIC:
                       maybe_warnx("bzip2 magic number error");
                       break;

               case BZ_MEM_ERROR:
                       maybe_warnx("bzip2 out of memory");
                       break;

               default:
                       maybe_warnx("unknown bzip2 error: %d", ret);
                       break;
               }
       }

       if (ret != BZ_STREAM_END || BZ2_bzDecompressEnd(&bzs) != BZ_OK)
               return (-1);

       return (bytes_out);
}