Wait for carrier in /etc/rc.d/defaultroute

[Jeremy Chadwick]

On Mon, Sep 27, 2010 at 08:23:52PM -0700, Doug Barton wrote:
> On 9/24/2010 5:04 PM, Ed Maste wrote:
> >/etc/rc.d/defaultroute currently bails immediately if all interfaces
> >set to use DHCP have no carrier.  This caused grief at work as it takes
> >some time for link to be established, and defaultroute ran before this
> >happened.  The rest of rc.d/ ran then before DHCP could assign an
> >address and route.
> >
> >The attached patch introduces a defaultroute_carrier_delay variable
> >and a change to /etc/rc.d/defaultroute to wait that long before bailing
> >out if there are no interfaces with carrier.  With the default settings
> >defaultroute will wait for five seconds to see if any interface gets
> >carrier.  The original 30 second wait for a default route to appear is
> >unchanged.
> >
> >Any comments?  I'll commit it sometime next week if there's no concern.
> 
> There was a more generic solution floating around fairly recently,
> from Jeremy Chadwick. The thread on this list starts back in april,
> but the latest version of the script appeared in june, so you might
> want to start there. I used versions of that script for most of this
> calendar year, and offered to commit it if the rc.conf.5 update was
> written.
> 
> Jeremy, if you've done that bit and I lost track, apologies, my
> FreeBSD time has been super limited lately, but it's on the upswing
> at the moment, so maybe you could update us?

Ack, I forgot all about this (and despite recommending the script to
someone on the lists a couple weeks ago)!  The script Doug's referring
to is available below, and should be placed into /usr/local/etc/rc.d (be
sure to chmod 755/555 it as well):

http://jdc.parodius.com/freebsd/netwait

Example usage in /etc/rc.conf:

netwait_enable="yes"
netwait_ip="4.2.2.1 4.2.2.2"
netwait_if="em0"
netwait_timeout="15"

This version lacks some of Doug's recommended changes (some minor syntax
changes and a more realtime indicator of what's going on by printing
dots/periods) -- I'll dig up Doug's Email from a while back and make
some time to implement his recommendations.

The idea in the long-run is to get this script committed to the base
system (e.g. /etc/rc.d), have rc.conf(5) updated to mention the
variables, in addition to src/etc/defaults/rc.conf.

Furthermore, I should probably file a PR for all of this...

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |