cannam@89: 
cannam@89: /* A test program written to test robustness to decompression of
cannam@89:    corrupted data.  Usage is 
cannam@89:        unzcrash filename
cannam@89:    and the program will read the specified file, compress it (in memory),
cannam@89:    and then repeatedly decompress it, each time with a different bit of
cannam@89:    the compressed data inverted, so as to test all possible one-bit errors.
cannam@89:    This should not cause any invalid memory accesses.  If it does, 
cannam@89:    I want to know about it!
cannam@89: 
cannam@89:    PS.  As you can see from the above description, the process is
cannam@89:    incredibly slow.  A file of size eg 5KB will cause it to run for
cannam@89:    many hours.
cannam@89: */
cannam@89: 
cannam@89: /* ------------------------------------------------------------------
cannam@89:    This file is part of bzip2/libbzip2, a program and library for
cannam@89:    lossless, block-sorting data compression.
cannam@89: 
cannam@89:    bzip2/libbzip2 version 1.0.6 of 6 September 2010
cannam@89:    Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org>
cannam@89: 
cannam@89:    Please read the WARNING, DISCLAIMER and PATENTS sections in the 
cannam@89:    README file.
cannam@89: 
cannam@89:    This program is released under the terms of the license contained
cannam@89:    in the file LICENSE.
cannam@89:    ------------------------------------------------------------------ */
cannam@89: 
cannam@89: 
cannam@89: #include <stdio.h>
cannam@89: #include <assert.h>
cannam@89: #include "bzlib.h"
cannam@89: 
cannam@89: #define M_BLOCK 1000000
cannam@89: 
cannam@89: typedef unsigned char uchar;
cannam@89: 
cannam@89: #define M_BLOCK_OUT (M_BLOCK + 1000000)
cannam@89: uchar inbuf[M_BLOCK];
cannam@89: uchar outbuf[M_BLOCK_OUT];
cannam@89: uchar zbuf[M_BLOCK + 600 + (M_BLOCK / 100)];
cannam@89: 
cannam@89: int nIn, nOut, nZ;
cannam@89: 
cannam@89: static char *bzerrorstrings[] = {
cannam@89:        "OK"
cannam@89:       ,"SEQUENCE_ERROR"
cannam@89:       ,"PARAM_ERROR"
cannam@89:       ,"MEM_ERROR"
cannam@89:       ,"DATA_ERROR"
cannam@89:       ,"DATA_ERROR_MAGIC"
cannam@89:       ,"IO_ERROR"
cannam@89:       ,"UNEXPECTED_EOF"
cannam@89:       ,"OUTBUFF_FULL"
cannam@89:       ,"???"   /* for future */
cannam@89:       ,"???"   /* for future */
cannam@89:       ,"???"   /* for future */
cannam@89:       ,"???"   /* for future */
cannam@89:       ,"???"   /* for future */
cannam@89:       ,"???"   /* for future */
cannam@89: };
cannam@89: 
cannam@89: void flip_bit ( int bit )
cannam@89: {
cannam@89:    int byteno = bit / 8;
cannam@89:    int bitno  = bit % 8;
cannam@89:    uchar mask = 1 << bitno;
cannam@89:    //fprintf ( stderr, "(byte %d  bit %d  mask %d)",
cannam@89:    //          byteno, bitno, (int)mask );
cannam@89:    zbuf[byteno] ^= mask;
cannam@89: }
cannam@89: 
cannam@89: int main ( int argc, char** argv )
cannam@89: {
cannam@89:    FILE* f;
cannam@89:    int   r;
cannam@89:    int   bit;
cannam@89:    int   i;
cannam@89: 
cannam@89:    if (argc != 2) {
cannam@89:       fprintf ( stderr, "usage: unzcrash filename\n" );
cannam@89:       return 1;
cannam@89:    }
cannam@89: 
cannam@89:    f = fopen ( argv[1], "r" );
cannam@89:    if (!f) {
cannam@89:       fprintf ( stderr, "unzcrash: can't open %s\n", argv[1] );
cannam@89:       return 1;
cannam@89:    }
cannam@89: 
cannam@89:    nIn = fread ( inbuf, 1, M_BLOCK, f );
cannam@89:    fprintf ( stderr, "%d bytes read\n", nIn );
cannam@89: 
cannam@89:    nZ = M_BLOCK;
cannam@89:    r = BZ2_bzBuffToBuffCompress (
cannam@89:          zbuf, &nZ, inbuf, nIn, 9, 0, 30 );
cannam@89: 
cannam@89:    assert (r == BZ_OK);
cannam@89:    fprintf ( stderr, "%d after compression\n", nZ );
cannam@89: 
cannam@89:    for (bit = 0; bit < nZ*8; bit++) {
cannam@89:       fprintf ( stderr, "bit %d  ", bit );
cannam@89:       flip_bit ( bit );
cannam@89:       nOut = M_BLOCK_OUT;
cannam@89:       r = BZ2_bzBuffToBuffDecompress (
cannam@89:             outbuf, &nOut, zbuf, nZ, 0, 0 );
cannam@89:       fprintf ( stderr, " %d  %s ", r, bzerrorstrings[-r] );
cannam@89: 
cannam@89:       if (r != BZ_OK) {
cannam@89:          fprintf ( stderr, "\n" );
cannam@89:       } else {
cannam@89:          if (nOut != nIn) {
cannam@89:            fprintf(stderr, "nIn/nOut mismatch %d %d\n", nIn, nOut );
cannam@89:            return 1;
cannam@89:          } else {
cannam@89:            for (i = 0; i < nOut; i++)
cannam@89:              if (inbuf[i] != outbuf[i]) { 
cannam@89:                 fprintf(stderr, "mismatch at %d\n", i ); 
cannam@89:                 return 1; 
cannam@89:            }
cannam@89:            if (i == nOut) fprintf(stderr, "really ok!\n" );
cannam@89:          }
cannam@89:       }
cannam@89: 
cannam@89:       flip_bit ( bit );
cannam@89:    }
cannam@89: 
cannam@89: #if 0
cannam@89:    assert (nOut == nIn);
cannam@89:    for (i = 0; i < nOut; i++) {
cannam@89:      if (inbuf[i] != outbuf[i]) {
cannam@89:         fprintf ( stderr, "difference at %d !\n", i );
cannam@89:         return 1;
cannam@89:      }
cannam@89:    }
cannam@89: #endif
cannam@89: 
cannam@89:    fprintf ( stderr, "all ok\n" );
cannam@89:    return 0;
cannam@89: }