Bug 103168

The port for isc-dhcp3-server has config options for enabling FreeBSD
process jails. Basically, through a series of command line arguments
that are generated by the isc-dhcpd.sh script, the chroot is
auto-generated when you start the service and dhcpd makes the syscall to
jail itself. This is actually really nifty and makes the process of
running dhcpd in a thin jail brainless.

The problem happens when I run "isc-dhcpd.sh stop": 
dhcpd not running? (check /var/jails/dhcpd/var/run/dhcpd/dhcpd.pid).

Well, I know better. dhcpd is clearly running with the pid indicated in
the pid file. After investigating /etc/rc.subr, I've determined the
cause (where $JID is the jid of the running rc script and $_jid is the
jid of the process, determined by ps output):
  if [ "$JID" -eq "$_jid" ];

This prevents me from using the rc script outside the jail to stop the
jail'd dhcpd process. /etc/rc.subr is making a false assumption that
people won't want to be controlling jailed services via rc scripts on
the host machine.

Fix: Override JID in isc-dhcpd.sh:
How-To-Repeat: In /etc/rc.conf:
dhcpd_enable="YES"
dhcpd_flags="-q"
dhcpd_conf="/usr/local/etc/dhcpd.conf"
dhcpd_includedir="/usr/local/etc/dhcpd.d"
dhcpd_withumask="022"
dhcpd_chuser_enable="YES"
dhcpd_withuser="dhcpd"
dhcpd_withgroup="dhcpd"
dhcpd_devfs_enable="YES"
dhcpd_rootdir="/var/jails/dhcpd"
dhcpd_chroot_enable="YES"
dhcpd_jail_enable="YES"
dhcpd_hostname="dhcp.example.com"
dhcpd_ipaddress="10.0.0.10"

Start dhcpd:
$ sudo /usr/local/etc/rc.d/isc-dhcpd.sh start
Starting dhcpd.

Try:
$ sudo /usr/local/etc/rc.d/isc-dhcpd.sh stop
dhcpd not running? (check /var/jails/dhcpd/var/run/dhcpd/dhcpd.pid).

But:
$ ps auxwww | grep dhcpd
dhcpd   11950  0.0  1.4 14940 14140  ??  SsJ   3:58PM   0:00.00 /usr/local/sbin/dhcpd -q -cf /usr/local/etc/dhcpd.conf -lf /var/db/dhcpd/dhcpd.leases -pf /var/run/dhcpd/dhcpd.pid -user dhcpd -group dhcpd -chroot /var/jails/dhcpd -jail dhcp.example.com 10.0.0.10