FreeLists / openbeosnetteam / [openbeosnetteam] Re: DHCP Stay Alive Question

[Waldemar Kornewald <Waldemar.Kornewald@xxxxxx>]

David Enderson wrote:
> > I guess we can consider DHCP being a protocol and making a network
> > protocol kernel module make sense to me. However, currently your
> > (C++) code can't be refactoring into a kernel module like this,
> > before move from socket API to internal API to send and receive
> > UDP packets, iterate and setup interfaces.
>
>
> I agree.  What you said makes perfect sense that the DHCP client should
> be a protocol module.

But that makes the DHCP code vulnerable to buffer overflow attacks. Is 
there any use in making DHCP really live (as a whole) in the kernel? I 
mean, if speed were an issue I would do it, but I cannot imagine any 
good reason to use that.
We could easily make the DHCP module run a dhcp_client userland app that 
cares for everything and communicates with the kernel module.

> I knew whatever I wrote would have to be switched all around and maybe
> be converted from C++ to C code.  I just tried to organize it well and
> write something since I knew I wouldn't be able to guess the correct
> format the first time.  When I get the DHCP conversation completely
> working, it looks like my next task will be to make a kernel protocol
> module.

You can continue using C++ in the kernel. It makes the code look cleaner 
and you can use BAutoLocker-like tools which simplify locking.

> Which existing kernel protocol module would you suggest I use as an
> example to make mine from?

Uhm, there is really nothing similar to DHCP in our kernel. Maybe, take 
a look at our "route" module. The ethernet and ARP modules might be 
interesting, too.

> > BTW, maybe it's a good occasion to write a kernel module exporting
> > the basic (without DNS resolver support at start) sockets API to
> > kernelland. That would help network-related drivers (netblock
> > devices?) and kernel add-ons (network filesystems) but also porting
> > your DHCP_client code...
>
>
> Since I don't know the exact status of everything, I'll take your word
> on the fact that its needed.  Are you saying this is needed before I can
> get my DHCP protocol module to work?

It would be rather difficult without such an API module (and you code 
would not be portable).

Bye,
Waldemar