[CUWiN-Dev] network watchdog ; netbsd source snapshot

[David Young]

*** Source snapshot ***

If you have an account on cuw, you will find the NetBSD sources I am
using at ~dyoung/cuwin-netbsd-snap-11-Jul-2005.tgz.  These are not
release-quality sources---I do know of a regression affecting IBSS
merges---but I hope that somebody can put them up on SourceForge for
people to download who are trying to track my development on a day-to-day
basis.

(If you have an account on cuw, then you know who you are.)

*** Network watchdog ***

I have added a "network watchdog" to the CUWiN station software.
The way it works is that every time hslsd receives a Hello on the
wireless interface, it runs a shell script, /usr/sbin/tickle,
to "tickle" a shell "watchdog" daemon.  The "tickling" is
rate-limited to once every 15 seconds or more.

As long as the shell daemon, /usr/sbin/hellowdog, is getting tickled
at least once every 5 minutes, it lays dormant.  (I realize I'm mixing
metaphors here.)  If 5 minutes do elapse without a tickle, hellowdog
wakes up and tries to restart hslsd.  If that doesn't work (because,
for example, hslsd is already running!), then it puts wdogctl to sleep.
wdogctl is in charge of tickling the hardware watchdog timer.  At most
32 seconds after wdogctl is put to sleep, the system will reboot.

In theory, if the wireless adapter or hslsd goes "out to lunch," the
network watchdog will bring the router back onto the network in 5 minutes
plus 32 seconds plus however long it takes for the node to reboot.

Dave

-- 
David Young             OJC Technologies
dyoung at ojctech.com      Urbana, IL * (217) 278-3933