Re: [Mldonkey-users] pthread MD4 hashing bug ?

[Goswin Brederlow]

Taros666 <address@hidden> writes:

> Sergio Bayarri Gausi wrote:
> > I agree here, it happened to me several times lately... I just had a
> > couple of files above 100% some minutes ago (one was about 23MB and the
> > other one is about 600MB). I verified the chunks and they went back to the
> > "real" size (the small file has already been downloaded). The big file
> > went from around 125% to 57.9% :(
> > I don't compile mldonkey using pthreads yet.
> 
> > Greetings,
> 
> > Sergio
> 
> 
> As I wrote about 4 times in the mldonkeyworld english forum:
> This is a problem of ALL ed2k-net Clients. Corrupted blocks are a
> problem of edonkey, Hybrid, lmule, emule, jmule, cdonkey and
> mldonkey. (at least 5 of them I personally tried ;) )

Didn't emule have checksums for smaller chunks than 9 MB? That should
detect errors faster and more precise and redownload only small parts.

> It seems that some smartasses want to get credit by uploading fake
> chunks to other clients, so they upload a lot of "zeros" (they get
> well compressed by emule). It "could" be an action of some other
> organisation (overpeer), but there seems to be at least some evidence,
> that it is a emule-mod trying to get credits (the real stupid thing
> is, that the credits are not granted, because the real uploaded data
> and NOT the uncompressed data is taken in account...)
> 
> So if you get some zeros, your whole chunk is bad, and has to be
> redownloaded. There are a leats 3 different patches for emule, that
> try to identify the "zeros-uploader" and ban them. At least 1
> emule-mod is already been released, that will ban these fakers...

There also seem to be spamer (or buggy clients) that have broken
md4sums for some chunks. The md4sum is that of a chunk full of
0's. Could be some client gotten spamed by a 0 uploader and not
checking the chunk but that would be just as evil as spaming itself.

MfG
        Goswin