#!/bin/sh
#
# $Id$
#
# Point the DNS for a domain to this server (the primary server)
# if this server can access the internet.
#
# This script should be run periodically on the primary host.
#
# Which DNS records are updated is determined by the ddclient
# configuration file (e.g. $HOME/.ddclient.<domain>.conf).
#
# You must set the following variables in ~/.checkdns
# domain    name of A record to redirect
# primary   public host name of server that should serve domain whenever possible

###
# FUNCTIONS
if test -f "${HOME}/bin/functions"
then
    . "${HOME}/bin/functions"
else
    echo "${0##/*/}: Cannot find function library, exiting"
    exit 1
fi

###
# CONFIGURATION
# defaults
debug=
quiet=
sms=true
syslog=true

while getopts "c:dq" flag
do
    case $flag in
    d)
        debug=true
        quiet=
        ;;
    q)
        quiet=true
        debug=
        ;;
    *)
        error "Invalid option -$flag"
        exit 2
    esac
done

# Read local configuration.
if test -f "${HOME}/.checkdns"
then
    . "${HOME}/.checkdns"
else
    error "Cannot find configuration file ${HOME}/.checkdns"
    exit 1
fi

# Configuration file for ddclient.
conf=$HOME/.ddclient.$domain.conf

###
# INITIALIZATION
tmpdir="$(get_temporary_directory)"
if test $? -ne 0
then
    error "Cannot use temporary directory"
    exit 1
fi

trap 'test -f "${tmpfile}" && rm -f ${tmpfile}' EXIT


###
# MAIN

primaryaddress="$(get_address_of ${primary})"
if test $? -eq 0
then
    debug "Address of primary server for ${domain} is ${primaryaddress}"
else
    error "Cannot get address of primary host ${primary}"
    exit 1
fi

domainaddress="$(get_address_of ${domain})"
if test $? -eq 0
then
    debug "Address of ${domain} is ${domainaddress}"
else
    error "Cannot get address of domain ${domain}"
    exit 1

fi

if test "${domainaddress}" != "${primaryaddress}"
then
    notice "Primary server for ${domain} is up, redirecting to ${primary} (${primaryaddress})"
    run /usr/sbin/ddclient -file "${conf}" -cache /dev/null -use=ip -ip "${primaryaddress}"
    if test $? -eq 0
    then
        info "Redirected ${domain} to ${primary}"
    else
        error "Error redirecting ${domain} to ${primary}"
        exit 1
    fi
else
    info "Primary server for ${domain} is already in charge, not redirecting"
fi