Re: [Vserver] sshd creates /dev/pts/*, how can I create a /dev/pts/rob with an init.d script?

From: Robert Michel <news_at_robertmichel.de>
Date: Thu 06 Jul 2006 - 17:44:12 BST
Message-ID: <20060706164412.GC30358@it1.de>

Salve Herbert!

Herbert Poetzl schrieb am Donnerstag, den 06. Juli 2006 um 13:10h:

> > but on the next day /usr/sbin/safe_asterisk does
> > not found /dev/tty9..... /dev/pts/31 exist only
> > for my bash, after exiting this bash, also
> > /dev/pts/31 has been gone, and so this "hack"
> > does not work... ;(
>
> precisely, either you _want_ that output to go
> somewhere, then you have to 'provide' a real vc
> terminal or to make asterisk 'create' it on startup
> (by requesting a new one, like e.g. screen does)

Exactly.

> you could, for example, use screen to provide that
> pseudo terminal without modifying asterisk

I have to play more with screen/dtach
- could screen create performance or other problems?
  IMHO does screen does much more than to just create
  a pseudo terminal and to slow asterik significant.
 
> better use /dev/vc/9 (c:4:9 or the udev equiv) but
> basically you 'could' create the device for the guest
> on the host side, and the guest will be able to use
> it, just be careful _what_ you give to your guests :)
 
> > So root@guest can indirectly create dumy devices
> > and there is still no tool like mknode for vserver
> > - because it is not so neccessary and does not
> > have such a high priority - right?
>
> no,
> because it is a big can of worms and a security
> issue, just imagine somebody creating a block device
> which 'accidentially' is identical to your host's
> root partition, and then starts modifying stuff at
> a very low level :)

You mean root@guest23 could do things with the
power of root@host?

I can understand that it is good that root@guest23
can't dump the RAM, read the bios etc...
and everybody who setup his own vserver is happy
about a securiy gain - but it is a bit different
for people who rent a vserver and are only
root@guest.

  BTW I'm in favor that by default every vserver
  installation creates a Vserver-README inside
  the root directory for every guest instance
  and a vserver-root@guest-HowTo.

  ISP are promoting vserver with "full root
  access" As far as I know yet root-guest
  can't use: iptables, ping, tracerout,
  ntp, mknod
  so some misunderstandings or noise on mailinglist
  will come automaticaly.
  When I know more about vservers, I will try
  to contribute in that way...

But back to the topic "could root@guest use mknod".
Theoreticaly would it possible to add this feature
with a vmknode and a tool for root@host that guest
could create a block devices of their own without
harming other guests or the host itself
but it seems not to be a planed feature for vserver.

It's unthankful that people asking everytime
about errors or thinks that are not supported
But I'm thankful about the vserver project
and that you have the focus on security

Greetings,
rob

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Received on Thu Jul 6 17:54:33 2006

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