#!/bin/bash
#----------------------------------------------------------------------
# reconfig-named 
#
# Allows easy way to config a chroot bind environmet
#
# This software is distributed under the GPL V2
#----------------------------------------------------------------------

progname="reconfig-named"
menutitle="Bind DNS reconfigurator"
config_file="/etc/conf.d/named"

check_root() {
        ####################### TEST ROOT PRIVILEDGES #######################
        # test if program start as root, warn user and terminate program
        # if not started as root
        #####################################################################

        if [ ! $(whoami) = "root" ]
        then
                # Access denied
                echo
                echo "This program requires root access to work properly."
		echo
                exit
        fi
}


check_dialog_bin() {
        ###################### LOOK FOR DIALOG BINARY #######################
        # check if the dialog program is installed at /usr/bin/dialog.  If
        # not warn the user and allow to install it using Pacman.
        #####################################################################
        local answer

        if [ ! -f "/usr/bin/dialog" ]
        then
                echo
                echo "The dialog program could not be found, and $progname needs it"
                echo "to display dialog messages."
                echo 
                echo -n "Do you want to install it using pacman (Y/N)? "
                read answer
                if [ $answer = "Y" ] || [ $answer = "y" ]
                then
                         echo "Installing dialog with pacman, please wait..."
                         pacman -S dialog
                else
                         echo
                         echo "Required program missing, cannot continue."
                         echo
                         exit
                fi
        fi
}

check_named_is_running() {
        ##################### LOOK IF NAMED IS RUNNING ######################
        # check if the named daemon is running, and return true if it is
        #####################################################################
        local retval
        declare -i retval=1    # default to think named is not running

        if [ -f /var/run/named/named.pid ] || [ -f /var/named/var/run/named/named.pid ]; then
            retval=0
        fi
        return $retval
}

file_header() {
        ################### WRITE STANDARD HEADER FILE ######################
        # Write standard header to /etc/rc.d/named file that is shared by
        # both environments
        #####################################################################

        echo "#" > $config_file
        echo "# Parameters to be passed to BIND" >> $config_file
        echo "#" >> $config_file
}

mod_init_normal() {
        ################# NORMAL ENVIRONMENT MODE CHANGES ###################
        # Normal environment options will be set within this routine
        # making named work the usual Archlinux way
        #####################################################################

	# write header to config file
        file_header

        # write named args for normal environment
        echo "NAMED_ARGS=\"-u named\"" >> $config_file

	# remove chroot directories if they exists
	rm -rf /var/named/{dev,var} 
}

normal_env() {
        ################# CHECK NORMAL ENVIRONMENT STATUS ###################
        # Check if named is running prior to making changes to it.  The 
        # changes allow named work the usual Archlinux way
        #####################################################################

        # before doing anything, check if bind is already configure in a
        # normal environment
        if [ -d /var/named/dev ]
        then
                if check_named_is_running
                then
                        # stop service, do changes to config and restart named again
                        /etc/rc.d/named stop
                        /bin/sleep 1
                        mod_init_normal
                        /etc/rc.d/named start
                else
                        # named is not running, just do the changes
                        mod_init_normal
                fi        
        else      
                echo "bind was previously configured for normal environment."
        fi
}

mod_init_chroot() {
        ################# CHROOT ENVIRONMENT MODE CHANGES ###################
        # Chroot environment options will be set within this routine
        #####################################################################

	# write header to config file
        file_header

        # write named args for normal environment
        echo "NAMED_ARGS=\"-u named -t /var/named -c /etc/bind/named.conf\"" >> $config_file

	# add chroot directories and files
	mkdir /var/named/dev
        mkdir -p /var/named/var/run/named
        mkdir -p /var/named/var/log

        # create needed devices
        mknod /var/named/dev/null c 1 3
        mknod /var/named/dev/random c 1 8

        # syncronize bind time with system time
        cp /etc/localtime /var/named/etc

        # adjust ownership and priviledges of new files
        chmod 666 /var/named/dev/{null,random}
        chown -R named:named /var/named/var
        chown -R root:named /var/named/dev
        chown named:named /var/named/etc/localtime
        chmod 640 /var/named/etc/localtime
}

chroot_env() {
        ################# CHECK CHROOT ENVIRONMENT STATUS ###################
        # Check if named is running prior to making changes to it.  The 
        # changes allow named work under a chroot environment
        #####################################################################

        # before doing anything, check if bind is already configure in a
        # chroot environment
        if [ ! -d /var/named/dev ]
        then
                if check_named_is_running
                then
                        # stop service, do changes to config and restart named again
                        /etc/rc.d/named stop
                        mod_init_chroot
                        /etc/rc.d/named start
                else
                        # named is not running, just do the changes
                        mod_init_chroot
                fi  
        else      
                echo "bind was previously configured for chroot environment."
        fi
}


####################### MAIN MENU LOGIC ########################
# This loop handles the main menu functionality and invoke the
# selected menu subroutine
################################################################
tempfile="/tmp/reconfig-named"    # temp file to store menu choice

# test root access
check_root

# check for /usr/bin/dialog
check_dialog_bin

dialog --backtitle "$progname"  --nocancel --title "$menutitle" --menu "\nSelect how the named enviroment will reside \n \n" 13 50 3 1 "Normal environment" 2 "Chroot environment" 3 "Exit this menu" 2> $tempfile
mynetsel=`cat $tempfile`
case $mynetsel in
        1)  normal_env ;;    # adjust named to work on a normal environment
        2)  chroot_env ;;    # adjust named to work on a chroot environment
esac

# remove temporary file and exit
rm $tempfile
exit