Re: [Nbd] Problems in negotiating modern handshake

[Alex Bligh <alex@...872...>]

Wouter,

> Yes, but that would need to be handled in serveconnection() anyway (and
> it is now, in git HEAD).

Indeed, it was two different problems.

I can't see GIT HEAD from here, but are you also checking for
oversize names? That's a remote DoS too (specify -1 as the name
length).

> > I don't think you want to return here, or if you have found the
> > server, you don't send the flags and the 124 bytes of zeroes (the bit
> > marked "common"), etc.
>
> Actually, you do. negotiate() is called once more, in mainloop(),
> unconditionally. At that point, negotiate() skips the first block of
> 'common' code (due to client and client->modern being set), and the
> first block of 'modern' code (due to client being set), but continues at
> the second block of 'common' code. By not returning at that position,
> the 'client' variable in serveloop never gets anything assigned in the
> case of the modern socket.

I couldn't see the flags actually being sent as anything other than
a zero. Perhaps I broke something else. I will recheck.

--
Alex Bligh