Re: [patch] Multiple ips for jails

[Joerg Sonnenberger <joerg@xxxxxxxxxxxxxxxxx>]

On Tue, Nov 14, 2006 at 10:00:54AM +0100, Simon 'corecode' Schubert wrote:
> Joerg Sonnenberger wrote:
> >At least the IPv6 case is incomplete as it doesn't deal with mapped ipv4
> >addresses. I also don't think the behaviour for INADDR_ANY is correct.
> 
> Could you elaborate on that?  How should mapped ipv4 addresses be handled?  
> I guess there would need to be a check for already used ipv4 addresses, and 
> vice versa.

If mapped IPv4 addresses are allowed, they should get exactly the same
handling as normal IPv4 addresses. Esp. mapped 127.0.0.1 needs to be
handled accordingly.

> What behaviour for INADDR_ANY would be correct?  (If you can use this term)

When a socket is allowed to bind to INADDR_ANY two things have to be
guarantied:
(a) Connections to it are effectively only allowed, when one of the jail
IPs can be used. E.g. if the jail is bound to 192.168.1.1 and 10.1.1.1,
but the machine has also 176.1.1.1 as IP, a connection to that must not
go to the jail.
(b) Connections *from* the jail must use one of the jail addresses as
source. E.g. when the jail is bound to 192.168.1.1 as before, a
connection to 10.1.1.2 must not use 10.1.1.1 as soure address.

This gets further complicated by the question whether or not binding to
broadcast and/or multicast addresses should be enabled by default.

Joerg