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