BIRD 3.0 utility for DN42 related operations

bird-dn42-util.conf

# BIRD 3.0 utility for DN42 related operations 
# To be used with:
#   include "bird-dn42-util.conf";
# in bird.conf main configuration file.

function reset_origin (int transit_; int origin)
{
    bgp_path.empty;
    bgp_path.prepend(origin);
    bgp_path.prepend(transit_);  # "transit" is a keyword since BIRD 3.0
    accept;
}

function mix_dn42 (int dn42_asn)
{
    if net ~ [ 172.20.0.0/14+ ] || net ~ [ fd00::/8+ ] then {
        bgp_path.filter([ 64600..64855, 76100..76199, 4242420000..4242429999 ]);
        if bgp_path.first != dn42_asn then bgp_path.prepend(dn42_asn);
    }
    accept;
}

filter only_dn42
{
    if net ~ [ 172.20.0.0/14{15,31} ] || net ~ [ fd00::/8{16,48} ] then accept;
    reject;
}

update-filters.sh

#!/bin/bash

AS=(
    AS64496
    AS64497
    AS-SET-EXAMPLE
)

set -e
[ "$(id -u)" = 0 ] || exec sudo -- "$0"
OUTPUT="$(mktemp)"
for as in "${AS[@]}"
do
    bgpq4 -6Ab -l "define ${as//-/_}" -R 48 -- "$as" | tee -a -- "$OUTPUT"
done
chmod 0644 -- "$OUTPUT"
mv -- "$OUTPUT" filters.conf