isc-dhcp3-server chroot behavior

[Andrew D. Clark]

Here's a patch to the isc-dhcpd.sh script in /usr/local/etc/rc.d that 
handles copying a few files out of /etc into the chroot for name 
resolution and also handles copying a directory of configs to be 
included (handy if you want to modularize the config):


--- isc-dhcpd.sh.orig   Fri Dec  3 14:21:50 2004
+++ isc-dhcpd.sh        Fri Dec  3 15:39:03 2004
@@ -11,6 +11,19 @@
 # dhcpd_enable="YES"
 #

+# ADC - I've made a few changes to this file.
+#
+# In order for name resolution to work (necessary if you want to use 
DNS
+# names in the config (e.g. fixed-address somehost instead of some IP)
+# copy the following out of /etc:      host.conf hosts localtime 
resolv.conf
+#
+# define a directory containing included config files and copy those
+# to the chroot too.  Otherwise, the real included configs must live 
in
+# the chroot.  This is confusing compared to the behavior of 
dhcpd.conf,
+# which is copied from /usr/local/etc/dhcpd.conf to the chroot at 
startup
+# and the chrooted copy should not be edited (since changes are lost 
at
+# startup)
+
 . /usr/local/etc/rc.subr

 name=dhcpd
@@ -37,6 +50,10 @@
 dhcpd_hostname=${dhcpd_hostname:-}                     # jail hostname
 dhcpd_ipaddress=${dhcpd_ipaddress:-}                   # jail ip 
address

+# added by ADC
+dhcpd_include_dir=${dhcpd_include_dir:-}       # directory containing 
included
+                                            # config files
+
 safe_run ()    # rc command [args...]
 {
        local _rc
@@ -409,6 +426,10 @@
        _dhcpd_conffile=${dhcpd_rootdir}${dhcpd_conffile}
        _dhcpd_pidfile=${dhcpd_rootdir}${dhcpd_pidfile}
        _dhcpd_leasesfile=${dhcpd_rootdir}${dhcpd_leasesfile}
+
+       #
+       # added by ADC
+       _dhcpd_include_dir=${dhcpd_rootdir}${dhcpd_include_dir}
 }

 setup_compat ()
@@ -450,6 +471,22 @@
                        safe_copy ${dhcpd_devdir} ${_dhcpd_devdir}
                fi
                safe_copy ${dhcpd_conffile} ${_dhcpd_conffile}
+
+               #
+               # added by ADC - copy files out of /etc for name 
resolution
+               # host.conf hosts localtime resolv.conf
+               safe_mkdir ${_dhcpd_rootdir}/etc
+               safe_copy /etc/host.conf ${_dhcpd_rootdir}/etc/host.conf
+               safe_copy /etc/hosts ${_dhcpd_rootdir}/etc/hosts
+               safe_copy /etc/localtime ${_dhcpd_rootdir}/etc/localtime
+               safe_copy /etc/resolv.conf 
${_dhcpd_rootdir}/etc/resolv.conf
+
+               #
+               # added by ADC - copy dhcpd_include_dir if defined
+               if [ -d "${dhcpd_include_dir}" ]; then
+                       safe_mkdir ${_dhcpd_include_dir}
+                       safe_copy ${dhcpd_include_dir} 
${_dhcpd_include_dir}
+               fi
        fi
 }



--On Friday, December 03, 2004 02:38:41 PM -0800 "Andrew D. Clark" 
<andrew.clark at ucsb.edu> wrote:

> Hello,
>
> I'm using the chrooted isc-dhcp3-server and I'd like the startup
> script to do a few extra things which it does not.  In order for name
> resolution to work for a chrooted dhcp server, the following files
> must be in /etc in the chroot:
>
> host.conf    hosts        localtime    resolv.conf
>
> The startup script doesn't handle copying those into the chroot,
> though I think it should.  Name resolution is handy if one wants to
> do something like:
>
> host somehost {
>         hardware ethernet blahblah;
>         fixed-address somehost.somedomain;
> }
>
> instead of using an IP address as the parameter for the fixed-address
> argument.
>
> I'd also like to add a feature to the rc script whereby one can
> define a directory containing configs to be included in the
> dhcpd.conf to also be copied to the chroot.  A large configuration
> file is often easier to handle if it is broken up into smaller files
> which are included into the dhcpd.conf.  If these included files
> lived only in the chroot, they'd have to be edited there, which would
> be confusing compared to the behavior of the dhcpd.conf in the
> chroot, which is copied from /usr/local/etc/dhcpd.conf at startup.
>
> I'm running isc-dhcp3-server-3.0.1.r14_6
> I'll happily submit a patch against the current rc script which
> implements these features if desired.
>
> --
> Andrew Clark
> Campus Network Programmer
> Office of Information Technology
> University of California, Santa Barbara
> andrew.clark at ucsb.edu (805) 893-5311



--
Andrew Clark
Campus Network Programmer
Office of Information Technology
University of California, Santa Barbara
andrew.clark at ucsb.edu (805) 893-5311