Guidance to implement io_select on network devices

Hi,

The dhcpcd port is stuck waiting for the libpcap patch to be accepted

https://github.com/the-tcpdump-group/libpcap/pull/1565

It's been a month since I sent my last changes to the PR and there's no 
answer so far. I wonder how should we proceed, should we wait more time?

The alternative that should be accepted upstream implies implementing 
`io_select` on network devices in gnumach. I'm not working on anything 
else right now, so I might try, but, how difficult would be?, is it 
doable? If so, I'd need some basic guidance on how to start doing this.