ports/115967: enable chrooted dhcpd on the FreeBSD 7.x

[Eygene Ryabinkin]

>Number:         115967
>Category:       ports
>Synopsis:       enable chrooted dhcpd on the FreeBSD 7.x
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-ports-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Aug 31 13:30:01 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Eygene Ryabinkin
>Release:        FreeBSD 7.0-CURRENT i386
>Organization:
Code Labs
>Environment:
System: FreeBSD XXX 7.0-CURRENT FreeBSD 7.0-CURRENT #9: Wed Aug 8 10:56:57 MSD 2007 root at XXX:/usr/src/sys/i386/compile/XXX i386

>Description:

rc.d script for the ISC dhcpd tries to locate the mount_devfs
executable and disables the creation of the device filesystem
at the chroot directory if the binary was not found.

The reason of the error is that mount_devfs was removed from
FreeBSD 7: see src/sbin/Makefile, rev. 1.164.

>How-To-Repeat:

Install FreeBSD 7, isc-dhcpd3 and try to run the daemon.  It will
warn you that 'dhcpd_devfs_enable disabled -- not available' and
dhcpd will not start because it won't see any bpf devices.

>Fix:

Check for the FreeBSD version and do not look for mount_devfs on
7-CURRENT and later.  The following patch implements a quick check
for the first symbol of the 'uname -r'.  It might be possible to
implement more fine-grained check to catch early 7-CURRENT versions
that had mount_devfs inside, but I doubt that it worth the effort.

--- files/isc-dhcpd.in.orig	2007-08-31 16:57:04.000000000 +0400
+++ files/isc-dhcpd.in	2007-08-31 16:58:15.000000000 +0400
@@ -354,12 +354,15 @@
 				err 1 "dhcpd_devfs_enable and dhcpd_makedev_enable" \
 				      "are mutually exclusive. enable only one!"
 			fi
+			# mount_devfs disappeared in FreeBSD 7.
+			if test `uname -r | cut -c 1` -le 6; then
 			if checkyesno dhcpd_devfs_enable &&
 			   ! ( type mount_devfs ) > /dev/null 2>&1; then
 				warn "dhcpd_devfs_enable disabled" \
 				     "-- not available"
 				dhcpd_devfs_enable=NO
 			fi
+			fi
 			if checkyesno dhcpd_makedev_enable &&
 			   ! [ -x ${__dhcpd_devdir}/MAKEDEV ]; then
 				warn "dhcpd_makedev_enable disabled" \
>Release-Note:
>Audit-Trail:
>Unformatted: