rom/filesys/SFS/SFSchecksum/SFSchecksum.c

   1 #include <dos/dos.h>
   2 #include <exec/memory.h>
   3 #include <proto/dos.h>
   4 #include <proto/exec.h>
   5
   6 #include "/fs/blockstructure.h"
   7
   8 /* ASM prototypes */
   9
  10 extern ULONG __asm RANDOM(register __d0 ULONG);
  11 extern LONG __asm STACKSWAP(void);
  12 extern ULONG __asm CALCCHECKSUM(register __d0 ULONG,register __a0 ULONG *);
  13 extern ULONG __asm MULU64(register __d0 ULONG,register __d1 ULONG,register __a0 ULONG *);
  14 extern WORD __asm COMPRESSFROMZERO(register __a0 UWORD *,register __a1 UBYTE *,register __d0 ULONG);
  15
  16 void setchecksum(void *cb);
  17
  18 const char version[]="\0$VER: SFSchecksum 1.0 (" ADATE ")\r\n";
  19
  20 ULONG bytes_block;                /* size of a block in bytes */
  21
  22 LONG main() {
  23   struct RDArgs *readarg;
  24   UBYTE template[]="FILE/A,BLOCKSIZE/N/A,BLOCK/N\n";
  25
  26   struct {char *file;
  27           ULONG *blocksize;
  28           ULONG *blockno;} arglist={NULL};
  29
  30   if((DOSBase=(struct DosLibrary *)OpenLibrary("dos.library",39))!=0) {
  31     if((readarg=ReadArgs(template,(LONG *)&arglist,0))!=0) {
  32       ULONG *buffer;
  33       ULONG blockno=0;
  34
  35       if(arglist.blockno!=0) {
  36         blockno=*arglist.blockno;
  37       }
  38
  39       bytes_block=*arglist.blocksize;
  40
  41       if((buffer=AllocVec(*arglist.blocksize, MEMF_PUBLIC))!=0) {
  42         BPTR fh;
  43
  44         if((fh=Open(arglist.file, MODE_OLDFILE))!=0) {
  45           if((Seek(fh, *arglist.blocksize * blockno, OFFSET_BEGINNING))==0) {
  46             ULONG old;
  47
  48             if(Read(fh, buffer, *arglist.blocksize)==*arglist.blocksize) {
  49               old=AROS_BE2LONG(buffer[1]);
  50
  51               setchecksum(buffer);
  52
  53               Printf("Block is of type 0x%08lx;", AROS_BE2LONG(buffer[0]));
  54               Printf(" ownblock is 0x%08lx\n", AROS_BE2LONG(buffer[2]));
  55               Printf("Checksum for this block was 0x%08lx",old);
  56               Printf(" but should be 0x%08lx\n",AROS_BE2LONG(buffer[1]));
  57             }
  58             else {
  59               PutStr("End of file reached.\n");
  60             }
  61           }
  62           else {
  63             PrintFault(IoErr(), "error while seeking in file");
  64           }
  65
  66           Close(fh);
  67         }
  68         else {
  69           PrintFault(IoErr(), "error while opening file");
  70         }
  71
  72         FreeVec(buffer);
  73       }
  74       else {
  75         PutStr("Out of memory\n");
  76       }
  77
  78       FreeArgs(readarg);
  79     }
  80     else {
  81       PutStr("wrong arguments\n");
  82     }
  83
  84     CloseLibrary((struct Library *)DOSBase);
  85   }
  86   return(0);
  87 }
  88
  89
  90
  91 void setchecksum(void *cb) {
  92   struct fsBlockHeader *bh=cb;
  93
  94   bh->checksum=0;    /* Important! */
  95   bh->checksum=-CALCCHECKSUM(bytes_block,cb);
  96 }
  97
  98
  99 BOOL checkchecksum(void *d) {
 100   ULONG *data=(ULONG *)d;
 101
 102   if(CALCCHECKSUM(bytes_block,data)==0) {
 103     return(TRUE);
 104   }
 105   return(FALSE);
 106 }