Pid file conflict running vtun in both client and server mode

[Jim Hatfield]

I'm trying to link three sites together using vtun.

Site A will be client to B and C.
Site B will be server to A and client to C.
Site C will be server to A and B.

A is a Linux box, B and C are FreeBSD.

The problem is site B. My rc.conf contains:

>vtund_enable="YES"
>vtunclient_enable="YES"
>vtunclient_flags="wycombe-fremont WWW.XXX.YYY.ZZZ"

The server process starts OK, but as soon as the client starts
it whines about the PID file already existing, and dies.

It appears the path to the PID file is hard coded as
/var/run/vtund.pid, so this is not surprising. And there does
not seem to be a command-line or config-file option to change it,
so how can I run two instances, short of modifying the Makefile.in,
editing the variable which specifies the path, building and
copying to, say, /usr/sbin/vtunclient?

I note that if box A were FreeBSD I would have further problems
since there doesn't seem to be the facility to run multiple clients,
though I guess I could hack the startup scripts in
/usr/local/etc/rc.d.