Chris@4: 
Chris@4: /* A test program written to test robustness to decompression of
Chris@4:    corrupted data.  Usage is 
Chris@4:        unzcrash filename
Chris@4:    and the program will read the specified file, compress it (in memory),
Chris@4:    and then repeatedly decompress it, each time with a different bit of
Chris@4:    the compressed data inverted, so as to test all possible one-bit errors.
Chris@4:    This should not cause any invalid memory accesses.  If it does, 
Chris@4:    I want to know about it!
Chris@4: 
Chris@4:    PS.  As you can see from the above description, the process is
Chris@4:    incredibly slow.  A file of size eg 5KB will cause it to run for
Chris@4:    many hours.
Chris@4: */
Chris@4: 
Chris@4: /* ------------------------------------------------------------------
Chris@4:    This file is part of bzip2/libbzip2, a program and library for
Chris@4:    lossless, block-sorting data compression.
Chris@4: 
Chris@4:    bzip2/libbzip2 version 1.0.6 of 6 September 2010
Chris@4:    Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org>
Chris@4: 
Chris@4:    Please read the WARNING, DISCLAIMER and PATENTS sections in the 
Chris@4:    README file.
Chris@4: 
Chris@4:    This program is released under the terms of the license contained
Chris@4:    in the file LICENSE.
Chris@4:    ------------------------------------------------------------------ */
Chris@4: 
Chris@4: 
Chris@4: #include <stdio.h>
Chris@4: #include <assert.h>
Chris@4: #include "bzlib.h"
Chris@4: 
Chris@4: #define M_BLOCK 1000000
Chris@4: 
Chris@4: typedef unsigned char uchar;
Chris@4: 
Chris@4: #define M_BLOCK_OUT (M_BLOCK + 1000000)
Chris@4: uchar inbuf[M_BLOCK];
Chris@4: uchar outbuf[M_BLOCK_OUT];
Chris@4: uchar zbuf[M_BLOCK + 600 + (M_BLOCK / 100)];
Chris@4: 
Chris@4: int nIn, nOut, nZ;
Chris@4: 
Chris@4: static char *bzerrorstrings[] = {
Chris@4:        "OK"
Chris@4:       ,"SEQUENCE_ERROR"
Chris@4:       ,"PARAM_ERROR"
Chris@4:       ,"MEM_ERROR"
Chris@4:       ,"DATA_ERROR"
Chris@4:       ,"DATA_ERROR_MAGIC"
Chris@4:       ,"IO_ERROR"
Chris@4:       ,"UNEXPECTED_EOF"
Chris@4:       ,"OUTBUFF_FULL"
Chris@4:       ,"???"   /* for future */
Chris@4:       ,"???"   /* for future */
Chris@4:       ,"???"   /* for future */
Chris@4:       ,"???"   /* for future */
Chris@4:       ,"???"   /* for future */
Chris@4:       ,"???"   /* for future */
Chris@4: };
Chris@4: 
Chris@4: void flip_bit ( int bit )
Chris@4: {
Chris@4:    int byteno = bit / 8;
Chris@4:    int bitno  = bit % 8;
Chris@4:    uchar mask = 1 << bitno;
Chris@4:    //fprintf ( stderr, "(byte %d  bit %d  mask %d)",
Chris@4:    //          byteno, bitno, (int)mask );
Chris@4:    zbuf[byteno] ^= mask;
Chris@4: }
Chris@4: 
Chris@4: int main ( int argc, char** argv )
Chris@4: {
Chris@4:    FILE* f;
Chris@4:    int   r;
Chris@4:    int   bit;
Chris@4:    int   i;
Chris@4: 
Chris@4:    if (argc != 2) {
Chris@4:       fprintf ( stderr, "usage: unzcrash filename\n" );
Chris@4:       return 1;
Chris@4:    }
Chris@4: 
Chris@4:    f = fopen ( argv[1], "r" );
Chris@4:    if (!f) {
Chris@4:       fprintf ( stderr, "unzcrash: can't open %s\n", argv[1] );
Chris@4:       return 1;
Chris@4:    }
Chris@4: 
Chris@4:    nIn = fread ( inbuf, 1, M_BLOCK, f );
Chris@4:    fprintf ( stderr, "%d bytes read\n", nIn );
Chris@4: 
Chris@4:    nZ = M_BLOCK;
Chris@4:    r = BZ2_bzBuffToBuffCompress (
Chris@4:          zbuf, &nZ, inbuf, nIn, 9, 0, 30 );
Chris@4: 
Chris@4:    assert (r == BZ_OK);
Chris@4:    fprintf ( stderr, "%d after compression\n", nZ );
Chris@4: 
Chris@4:    for (bit = 0; bit < nZ*8; bit++) {
Chris@4:       fprintf ( stderr, "bit %d  ", bit );
Chris@4:       flip_bit ( bit );
Chris@4:       nOut = M_BLOCK_OUT;
Chris@4:       r = BZ2_bzBuffToBuffDecompress (
Chris@4:             outbuf, &nOut, zbuf, nZ, 0, 0 );
Chris@4:       fprintf ( stderr, " %d  %s ", r, bzerrorstrings[-r] );
Chris@4: 
Chris@4:       if (r != BZ_OK) {
Chris@4:          fprintf ( stderr, "\n" );
Chris@4:       } else {
Chris@4:          if (nOut != nIn) {
Chris@4:            fprintf(stderr, "nIn/nOut mismatch %d %d\n", nIn, nOut );
Chris@4:            return 1;
Chris@4:          } else {
Chris@4:            for (i = 0; i < nOut; i++)
Chris@4:              if (inbuf[i] != outbuf[i]) { 
Chris@4:                 fprintf(stderr, "mismatch at %d\n", i ); 
Chris@4:                 return 1; 
Chris@4:            }
Chris@4:            if (i == nOut) fprintf(stderr, "really ok!\n" );
Chris@4:          }
Chris@4:       }
Chris@4: 
Chris@4:       flip_bit ( bit );
Chris@4:    }
Chris@4: 
Chris@4: #if 0
Chris@4:    assert (nOut == nIn);
Chris@4:    for (i = 0; i < nOut; i++) {
Chris@4:      if (inbuf[i] != outbuf[i]) {
Chris@4:         fprintf ( stderr, "difference at %d !\n", i );
Chris@4:         return 1;
Chris@4:      }
Chris@4:    }
Chris@4: #endif
Chris@4: 
Chris@4:    fprintf ( stderr, "all ok\n" );
Chris@4:    return 0;
Chris@4: }