[asterisk-dev] dynamic spans: /etc/zaptel/dynamic.conf ?

[Tzafrir Cohen]

On Fri, Mar 21, 2008 at 09:01:57AM -0400, Brett Carrington wrote:
> Tzafrir,
>   I appreciate your commitment to improving the dynamic span
> subsystem. I agree that over all the implementation is clunky and in
> need of a lot of attention.
> 
>   Although separating the dynamic spans into separate files will
> prevent accidental crashes in some cases it does not fix the real
> issue. Instead it merely hides the underlying problem and lulls the
> user into a false sense of security (woe be unto them when they try to
> intentionally reconfigure ztdynamic spans without following the
> procedure I outlined in the bug.) Based on this I am not sure if
> changing the configuration file conventions is worth the confusion it
> may create?

I'm not trying to ignore the problem. But I realise that I can't just
change a form / interface and hope it will stick.

I speculatethat with my suggestion well-behaving utilities (sticking
with very simple guidelines) will not be able to crash, and I still
don't change any interface.

The guidelines are indeed very simple. I'm still not 100% certain that
they make things crash-prone. Do they?

Are there any technical messures of enforcing them? At the level of
ztcfg - easily - only process "dynamic" if an extra command-line flag is
used. But this is still pretending. Anybody with write access to
/dev/zap/ctl (and Asterisk is one - if you don't run Asterisk as root.
And you don't run Asterisk as root, do you?).

Do we give /dev/zap/ctl different write permissions? Allow only root to
write to it (but allow Asterisk to read from it). Asterisk's chan_zap
uses ZT_SET_DIALPARAMS so this will break asterisk. I did not check
further.

And yes - ztdynamic.c is buggy and ztd-eth.c is buggy. But before
jumping up and fixing them, I'd like to have an idea at where we're
heading.

-- 
               Tzafrir Cohen
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