[Swan-dev] Question on writefds fd

[Paul Wouters]

On Fri, 16 Jan 2015, Antony Antony wrote:

> There are two mysterious functions/events that I don't understand yet.
> pfkey_dequeue(void). This is also probably related to old OE and klips.

Note that netkey/xfrm does not support/use this function.

>From a comment in the function:

         /* Handle any orphaned holds, but only if no pfkey input is
 	 * pending.
          * For each, we initiate Opportunistic.

This might indicate missing OE functionality for netkey/xfrm!

> connection_check_ddns() which calls
> 	connection_check_ddns1(). It seems to wakeup every minute and do
> ttoaddr(c->dnshostname, 0, AF_UNSPEC, &new_addr);

This seems to be the dynamic dns support. If a connection used a DNS
name, this event will resolve these names again. This was to support
people dynamic IP that used a static hostname like foo.dyn.org.

I'm a little concerned this happens every minute. Possibly this was done
in case the remote vanished and appeared elsewhere so we would
proactively find out about it sooner. But that's really the job of
dpd/liveness, and I think these lookups should only be done when
initiating (as a result of the original --add/--up, or as a result
of a dpd/liveness timeout or rekey event. So I think this event should
not be ported to libevent.

Paul