www.pudn.com > RakNet-2.52.zip > unzcrash.c

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