Re: proposed /etc/rc.d/staticroute change to allow variables

[David Brownlee <abs%netbsd.org@localhost>]

On 17 October 2011 22:19, Tracy Di Marco White <netbsd-t%menelos.com@localhost> 
wrote:
> Currently I have done this for local systems:
>
> % cat /etc/rc.conf.d/staticroute
> ifname=$(ifconfig -lbs | awk '{print $1}')
> ipaddr=$(ifconfig ${ifname} | awk '$1 == "inet" {print $2}')
> staticroute_doit() {
>        if [ -s /etc/route.conf ]; then
>                echo "$1 static routes."
>                while read args; do
>                        [ -z "$args" ] && continue
>                        case "$args" in
>                        "#"*)
>                                ;;
>                        "+"*)
>                                [ $2 = "add" ] && eval ${args#*+}
>                                ;;
>                        "-"*)
>                                [ $2 = "delete" ] && eval ${args#*-}
>                                ;;
>                        *)
>                                eval route -q $2 -$args
>                                ;;
>                        esac
>                done < /etc/route.conf
>        fi
> }
> % cat /etc/route.conf
> #
> net 10.10.1.0  -netmask 255.255.255.0 ${ipaddr} ; true work
> net 10.10.6.0  -netmask 255.255.255.0 ${ipaddr} ; true work
> net 10.10.142.0 -netmask 255.255.255.0 ${ipaddr} ; true work
> %
>
> The only difference between the system staticroute_doit() and mine is
> the "eval" before the route. Without it, I can't have "; true work"
> (which I can get rid of anyway), and I can't have ${ipaddr} to easily
> deal with IP address and interface changes.
>
> If adding 'eval' to *) seems too risky, alternatively an additional
> option of ! would work as well, such that staticroute_doit() looks
> like:
>
> staticroute_doit() {
>        if [ -s /etc/route.conf ]; then
>                echo "$1 static routes."
>                while read args; do
>                        [ -z "$args" ] && continue
>                        case "$args" in
>                        "#"*)
>                                ;;
>                        "+"*)
>                                [ $2 = "add" ] && eval ${args#*+}
>                                ;;
>                        "-"*)
>                                [ $2 = "delete" ] && eval ${args#*-}
>                                ;;
>                        "!"*)
>                                eval route -q $2 -${args#*!}
>                                ;;
>                        *)
>                                route -q $2 -$args
>                                ;;
>                        esac
>                done < /etc/route.conf
>        fi
> }
>
> and /etc/route.conf looks like:
>
> !net 10.10.1.0  -netmask 255.255.255.0 ${ipaddr} ; true durham95
> !net 10.10.6.0  -netmask 255.255.255.0 ${ipaddr} ; true durham95
> !net 10.10.142.0 -netmask 255.255.255.0 ${ipaddr} ; true durham95
>
> Opinions? Objections?
>

Since ! has a well defined meaning in ifconfig.if, maybe use a '$' or
similar prefix to mean eval?