Time for a 6.00 release?

Nikos Mavrogiannopoulos nmav at gnutls.org
Tue Jun 24 09:26:34 PDT 2014

On Tue, Jun 24, 2014 at 5:04 PM, Kevin Cernekee <cernekee at gmail.com> wrote:
> <nmav at gnutls.org> wrote:
>>> Hm, joy. So that's a third way of negotiating the MTU, and this time
>>> possibly even after the interface has been set up?
>> That's a quite reasonable approach as one's idea of the MTU during
>> negotiation may not be precise. I don't think it's an issue to change
>> the MTU of the tun device at any point (at least if you know the name
>> of the tun device and SIOCSIFMTU is available).
> That does require CAP_NET_ADMIN; Android will have a problem with
> this.  The app only has the ability to perform a one-time interface
> setup through a special API[1]; it doesn't run with root access.

Could the MTU discovery phase take place prior to establishing the
TUN? I.e., send the special DPD and expect a reply within a second or
two. If the reply is received create the device, if not resend a
smaller packet. That would add few seconds of latency in the creation
of the tun device and the channel, but the user wouldn't need to
search for the mtu manually.


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