Valhalla Legends Archive

The two functions in NBBot called UDPChecksum() and SubChecksum(), are they proven to work?

Quote from: PiaNKA on June 23, 2004, 04:41 PM
The two functions in NBBot called UDPChecksum() and SubChecksum(), are they proven to work?

test them :X

A little rant on forum etiquette...

1.) If you wanted this to go to Adron, you should have sent him a private message.  If you wanted other people to reply to your question, a more descriptive title, such as "Accuracy of NBBot Checksum functions" might have been more appropriate.

2.) Gosu -- this might be a bit of a suprise to you, but you don't have to reply to *every* thread.  You don't contribute much at all to the realm of original knowledge.  To suggest that he "test" the functions would be to suggest that he compile a list of all possible input and output values and run them through the function.  Impractical, I might say.  And warzone's thread -- your blinding revelation of "buy a book" (where one or two people had already suggested it) is the same way.  Perhaps suggesting a specific book would have been helpful, but what you said was just a way to get your name on the post.

And I'm spent.

Please accept my apology;)

Quote from: Myndfyre on June 23, 2004, 06:11 PM
A little rant on forum etiquette...

1.) If you wanted this to go to Adron, you should have sent him a private message.  If you wanted other people to reply to your question, a more descriptive title, such as "Accuracy of NBBot Checksum functions" might have been more appropriate.

2.) Gosu -- this might be a bit of a suprise to you, but you don't have to reply to *every* thread.  You don't contribute much at all to the realm of original knowledge.  To suggest that he "test" the functions would be to suggest that he compile a list of all possible input and output values and run them through the function.  Impractical, I might say.  And warzone's thread -- your blinding revelation of "buy a book" (where one or two people had already suggested it) is the same way.  Perhaps suggesting a specific book would have been helpful, but what you said was just a way to get your name on the post.

And I'm spent.

is this a wasted post? just like wasted bandwidth to brighten the day!

GoSuGaMING: This might also come as a surprise to you, but a lot of people here think you are a complete and total ass. If you don't clean up your act, I will request that you be banned from the forum - and I'm on excellent terms with the forum admins, so my request WILL be granted.

You have been warned.

On a lighter note, can anyone post UDPChecksum() and SubChecksum() (maybe Pianka)?

I'm curious as to what it looks like and how it works....

Quote from: Zakath on June 23, 2004, 08:54 PM
GoSuGaMING: This might also come as a surprise to you, but a lot of people here thing you are a complete and total ass.

I agree totally.

Quote from: Kk)Blaze(kK on June 23, 2004, 09:14 PM

Quote from: Zakath on June 23, 2004, 08:54 PM
GoSuGaMING: This might also come as a surprise to you, but a lot of people here thing you are a complete and total ass.

I agree totally.

Second.

Anyway, I'd also like to see these functions.


unsigned long subchecksum(unsigned char *buf, int len)
{
   unsigned sum1=0, sum2=0;
   unsigned char *p;
   p = buf+len-1;
   while(len--) {
      sum2 += *p--;
      if(sum2 > 0xff)
         sum2 -= 0xff;
      sum1 += sum2;
   }
   return ((sum2 & 0xff)<<8) | ((sum1 % 0xff) & 0xff);
}


I cant find the other

Public Function UDPChecksum(ByVal buffer As String, ByVal size As Long) As Long
Dim a&, b&, n&, q&, sum&
   For n = 0 To size - 1
       a = a + ((n + 1) * Asc(Mid$(buffer, n + 1, 1)))
       b = b + ((n + 2) * Asc(Mid$(buffer, n + 1, 1)))
   Next n
   q = a
   While (q > &HFF)
       q = (q / &H100) + (q Mod &H100)
   Wend
   sum = q
   q = b
   While (q > &HFF)
       q = (q / &H100) + (q Mod &H100)
   Wend
   sum = sum + (LShift(&HFF - q, 8))
   UDPChecksum = sum
End Function


And the vb version of checksum...


Public Sub InitCRC32()
   Dim i As Long, J As Long, K As Long, XorVal As Long
   Static CRC32Initialized As Boolean
   If CRC32Initialized Then Exit Sub
   CRC32Initialized = True
   For i = 0 To 255
       K = i
       For J = 1 To 8
           If K And 1 Then XorVal = CRC32_POLYNOMIAL Else XorVal = 0
           If K < 0 Then K = ((K And &H7FFFFFFF) \ 2) Or &H40000000 Else K = K \ 2
           K = K Xor XorVal
       Next
       CRC32Table(i) = K
   Next
End Sub
Public Function CRC32(ByVal data As String) As Long
   Dim i As Long, J As Long
   Call InitCRC32
   CRC32 = &HFFFFFFFF
   For i = 1 To Len(data)
       J = CByte(Asc(Mid(data, i, 1))) Xor (CRC32 And &HFF&)
       If CRC32 < 0 Then CRC32 = ((CRC32 And &H7FFFFFFF) \ &H100&) Or &H800000 Else CRC32 = CRC32 \ &H100&
       CRC32 = CRC32 Xor CRC32Table(J)
   Next
   CRC32 = Not CRC32
End Function

'Put this in some module...
Public Const CRC32_POLYNOMIAL As Long = &HEDB88320
Public CRC32Table(0 To 255) As Long

Quote from: Kk)Blaze(kK on June 24, 2004, 12:21 AM
And the vb version of checksum...

Wrong checksum -- read the thread before replying.

So does that mean nobody is gonna post it for me?

Quote from: Zakath on June 23, 2004, 08:54 PM
GoSuGaMING: This might also come as a surprise to you, but a lot of people here think you are a complete and total ass. If you don't clean up your act, I will request that you be banned from the forum - and I'm on excellent terms with the forum admins, so my request WILL be granted.

You have been warned.

You forgot "moron!"