From: Michal Suchanek <hramrach@...>
Date: 2007-05-16T20:01:12+09:00
Subject: Re: DRb connection error with more than 250+ DRb services

On 14/05/07, Brian Candler <B.Candler@pobox.com> wrote:
> On Mon, May 14, 2007 at 11:13:34PM +0900, Michal Suchanek wrote:
> > Of course, the FDs are only to organize your IO. You can use TCP ans
> > the OS provided sockets, or you can use a single UDP socket and
> > maintain the connection state yourself.
>
> If you want to run your own TCP stack you'll need to open a raw socket, and
> you can't do that unless you're root, because of the security implications
> (e.g. ordinary users could masquerade as privileged services such as SMTP on
> port 25)
>
> > Similarly the FDs to open files give you organized access to space on
> > a disk drive, and you can always open the partition device and manage
> > the storage yourself.
>
> Similarly, only root can have direct access to the raw device. Otherwise,
> any user would be able to read any other user's files, modify any file at
> whim, totally corrupt the filesystem etc.
>
Of course, using UDP is not the same as implementing your own TCP
stack. You just do not need the enormous amounts of sockets even if
you communicate with multiple hosts. And you have to keep track of the
communication yourself because the OS will not do it for you.

Also you would want to decide for each partition if you use it for a
filesystem and mount it, or give access to the partition to a service
or user. Note that mtools use raw floppy devices in exactly this way,
and given the access they can be used for partitions as well.

Thanks

Michal