#!/bin/sh
# Template to generate a bgp protocol configuration file for bird(1).
# Required non-empty variables:
# __object_id, local_{ip,as}, neighbor_{ip,as}
#
# Required defined variables:
# description, password, ipv{4,6}_{import,export}

# Header
echo "protocol bgp ${__object_id:?} {"

# Optional description
[ -n "${description?}" ] && printf "\tdescription \"%s\";\n" "${description?}"

# Mandatory session information
cat << EOF
	local ${local_ip?} as ${local_as:?};
	neighbor ${neighbor_ip:?} as ${neighbor_as:?};
EOF

# Direct connection ?
[ -n "${direct?}" ] && printf "\tdirect;\n"

# Password-protected session ?
[ -n "${password?}" ] && printf "\tpassword \"%s\";\n" "${password?}"

if [ -n "${ipv4_import?}" ] || [ -n "${ipv4_export?}" ] || "${ipv4_extended_next_hop?}";
then
	printf "\tipv4 {\n"
	[ -n "${ipv4_import?}" ] && printf "\t\timport %s;\n" "${ipv4_import:?}"
	[ -n "${ipv4_export?}" ] && printf "\t\texport %s;\n" "${ipv4_export:?}"
	[ -n "${ipv4_extended_next_hop?}" ] && printf "\t\textended next hop;\n"
	printf "\t};\n"
fi
if [ -n "${ipv6_import?}" ] || [ -n "${ipv6_export?}" ] || "${ipv6_extended_next_hop?}";
then
	printf "\tipv6 {\n"
	[ -n "${ipv6_import?}" ] && printf "\t\timport %s;\n" "${ipv6_import:?}"
	[ -n "${ipv6_export?}" ] && printf "\t\texport %s;\n" "${ipv6_export:?}"
	[ -n "${ipv6_extended_next_hop?}" ] && printf "\t\textended next hop;\n"
	printf "\t};\n"
fi

# Header close
echo "}"