#!/bin/sh

set -e

if [ ! -f /usr/local/etc/bird-peers-update.conf ]; then
	printf "Write /usr/local/etc/bird-peers-update.conf with at least "
	printf "PDB_API_KEY and BIRD_CONF_PATH vars\n"
	exit 1
else
	. /usr/local/etc/bird-peers-update.conf
fi

# comma list
NEVER_VIA_RS_LIST="$(
	curl -H 'Authorization: Api-Key '"${PDB_API_KEY}" \
		-s 'https://www.peeringdb.com/api/net?info_never_via_route_servers=1' | \
		jq '.data[].asn' | sort -n | tr '\n' ',' | sed 's/,/, /g;s/, $//'
)"

# bird set
NEVER_VIA_RS_SET="$(
	printf "[ ${NEVER_VIA_RS_LIST} ]"
)"


if [ -n "${NEVER_VIA_RS_SET}" ]; then
printf "# generated by $0 $@
function check_import(int peeras; ip nexthop)
  int set reserved_asn;
  int set never_via_rs;
{
    reserved_asn = [ 0, 64297..131071, 4200000000..4294967294, 4294967295 ];

    never_via_rs = ${NEVER_VIA_RS_SET};

    # Check that the next AS is our neighbour's.
    # Same for next-hop
    if bgp_path.first != peeras then return false;
    if bgp_next_hop != nexthop then return false;

    # AS_PATH too long (8 because a member could re-annonce its clients, and
    # the clients of it clients, and prepend on the IXP)
    if bgp_path.len > 8 then return false;

	# Don't accept if path contains a reserved AS
	# Disabled because it removes legit prefixes
	if bgp_path ~ reserved_asn then return false;
	if bgp_path ~ never_via_rs then return false;

    return true;
}
" > "${BIRD_CONF_PATH}"/check_import.conf
fi