9 Jun
2010
9 Jun
'10
11:58 a.m.
On 06/09/2010 05:45 PM, Sylvain Munaut wrote:
Oh, I didn't know that, that is funny. Well we have two settings here...
one is if we want encryption on, the second is if that subscriber can do
encryption. With what I have in mind, you would get the subscriber
connection (currently embedded in the lchan) on a new connection and
then your function can decide to close the channel, or to secure it and
then hand it to someone else.
Ok, when I look back at the code, most of it was
gsm_04_08.c only. But
not all of it. I needed some change in the paging system because once
a paging succeded, I needed to be able to 'inject' myself before the
callback was called. (So that I could secure the channel in the
meantime).
Makes sense. This will certainly be more easy with the split but we need
a dispatcher in the MSC code. That is doing auditing, then does other
stuff, then hands it over to the subsystem, once the subsystem is done,
we can hand it to the next one or close (leaving SMS during a phonecall
out of the picture).
3.) better lchan management and this is
where encyrption comes
in. When we have a new connection, we should run it through
auth first... and then hand it to the subsystem.
One thing that makes a 'transparent' implementation tricky is that a
CIPHER MODE COMMAND is considered to be an implicit CM SERVICE ACCEPT.
So what the code did it to offer a simple function to call whenever
you wanted to secure the channel and offer a callback with the result.