Date: Thu, 24 Apr 2014 19:13:33 +0200 From: "Julian H. Stacey" <jhs@berklix.com> To: Rolf Nielsen <rmg1970swe@gmail.com> Cc: User questions <freebsd-questions@freebsd.org> Subject: Re: Running a command when a specific interface is created or destroyed Message-ID: <201404241713.s3OHDXkZ013843@fire.js.berklix.net> In-Reply-To: Your message "Thu, 24 Apr 2014 08:51:08 -0600." <alpine.BSF.2.00.1404240849380.4641@wonkity.com>
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Warren Block wrote: > On Thu, 24 Apr 2014, Rolf Nielsen wrote: > > > Hi, > > > > I use my phone's 3G/4G connection to connect my computer to the > > internet. With the help of the urndis driver, it comes up as ue0. > > However, if I reboot the computer, the phone automatically disables USB > > tethering, and I can't re-enable it until the boot is complete. > > > > Being somewhat paranoid, I use an OpenVPN service, and I want the cilent > > to start automatically. I obviously can't set it to start from rc.conf, > > as I can't log in to the server before I have an internet connection. > > > > So, is there a way to start the OpenVPN client automatically upon > > creation of the ue0 interface? E.g. can dhclient be set up to run the > > openvpn start script after it has given ue0 an IP address? And is there > > a way to automatically stop the openvpn client if ue0 is destroyed, e.g. > > if I disconnect my phone from the computer? > > devd(8) can do that. Look at /etc/devd.conf for some examples, and > devd.conf(5) for more detail. Yes, devd & its conf are very useful. > > So, is there a way to start the OpenVPN client automatically upon > > creation of the ue0 interface? Yes, Example: I automatically fetch a password (if environment is secure) to gbde decrypt & mount a UFS when a USB stick is attached. http://www.berklix.com/~jhs/src/bsd/fixes/FreeBSD/src/jhs/etc/devd/berklix.conf See lines beginning: gbde attach On detach, closing processes or unmounting file systems Before a device disappears is more problematic, as devd only gets nudged after. I suppose if a VPN has a watchdog/ keepalive, no problem. (For my crypted UFS, I should config AMD to umount my /media/* on timeout, [& remount on demand]). Cheers, Julian -- Julian Stacey, BSD Unix Linux C Sys Eng Consultant, Munich http://berklix.com Interleave replies below like a play script. Indent old text with "> ". Google breach privacy http://berklix.com/jhs/adverts/
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