#!/bin/bash
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2007-2022  IPFire Team  <info@ipfire.org>                     #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

. /etc/sysconfig/rc
. ${rc_functions}

# Set PATH to find our own executables
export PATH=/usr/local/sbin:/usr/local/bin:${PATH}

# GCP only supports an MTU of 1460
DEFAULT_MTU=1460

get() {
	local file="${1}"

	wget -qO - "http://169.254.169.254/opc/v1/${file}"
}

try_base64_decode() {
	local input="${1}"

	local tmp="$(mktemp)"

	# Try to decode this and return output if successful
	if base64 -d <<< "${input}" > "${tmp}" 2>/dev/null; then
		echo "$(<${tmp})"

	# Otherwise just return the input
	else
		echo "${input}"
	fi

	# Cleanup
	unlink "${tmp}"
}

to_address() {
	local n="${1}"

	local o1=$(( (n & 0xff000000) >> 24 ))
	local o2=$(( (n & 0xff0000) >> 16 ))
	local o3=$(( (n & 0xff00) >> 8 ))
	local o4=$(( (n & 0xff) ))

	printf "%d.%d.%d.%d\n" "${o1}" "${o2}" "${o3}" "${o4}"
}

to_integer() {
	local address="${1}"

	local integer=0

	local i
	for i in ${address//\./ }; do
		integer=$(( (integer << 8) + i ))
	done

	printf "%d\n" "${integer}"
}

prefix2netmask() {
	local prefix=${1}

	local zeros=$(( 32 - prefix ))
	local netmask=0

	local i
	for (( i=0; i<${zeros}; i++ )); do
		netmask=$(( (netmask << 1) ^ 1 ))
	done

	to_address "$(( netmask ^ 0xffffffff ))"
}

oci_list_interfaces() {
	get "vnics/" | python3 -c "import json, sys; print(\"\n\".join([vnic[\"vnicId\"] for vnic in json.load(sys.stdin)]))"
}

oci_get_interface_param() {
	local id="${1}"
	local param="${2}"

	get "vnics/" | python3 -c "import json, sys; print(\"\n\".join(vnic.get(\"${param}\", \"\") for vnic in json.load(sys.stdin) if vnic[\"vnicId\"] == \"${id}\"))"
}

import_oci_configuration() {
	local instance_id="$(get instance/id)"

	boot_mesg "Importing Oracle Cloud Infrastructure configuration for instance ${instance_id}..."

	# Store instance ID
	echo "${instance_id}" > /var/run/oci-instance-id

	# Initialise system settings
	local hostname=$(get instance/hostname)

	# Set hostname
	if ! grep -q "^HOSTNAME=" /var/ipfire/main/settings; then
		echo "HOSTNAME=${hostname%%.*}" >> /var/ipfire/main/settings
	fi

	# Set domainname
	if ! grep -q "^DOMAINNAME=" /var/ipfire/main/settings; then
		echo "DOMAINNAME=${hostname#*.}" >> /var/ipfire/main/settings
	fi

	# Create setup user
	if ! getent passwd setup &>/dev/null; then
		useradd setup -s /usr/bin/run-setup -g nobody -m

		# Unlock the account
		usermod -p "x" setup
	fi

	# Import SSH keys for setup user
	local line
	while read -r line; do
		# Strip the username part from the key
		local key="${line#*:}"

		if [ -n "${key}" ] && ! grep -q "^${key}$" "/home/setup/.ssh/authorized_keys" 2>/dev/null; then
			mkdir -p "/home/setup/.ssh"
			chmod 700 "/home/setup/.ssh"
			chown setup.nobody "/home/setup/.ssh"

			echo "${key}" >> "/home/setup/.ssh/authorized_keys"
			chmod 600 "/home/setup/.ssh/authorized_keys"
			chown setup.nobody "/home/setup/.ssh/authorized_keys"
		fi
	done <<<"$(get instance/metadata/ssh_authorized_keys)"

	# Import network configuration
	# After this, no network connectivity will be available from this script due to the
	# renaming of the network interfaces for which they have to be shut down
	local config_type=1
	: > /var/ipfire/ethernet/settings

	local id
	for id in $(oci_list_interfaces); do
		local mac="$(oci_get_interface_param "${id}" "macAddr")"

		# First IPv4 address
		local ipv4_address="$(oci_get_interface_param "${id}" "privateIp")"
		local ipv4_address_num="$(to_integer "${ipv4_address}")"

		local subnet="$(oci_get_interface_param "${id}" "subnetCidrBlock")"
		local prefix="${subnet#*/}"

		local netmask="$(prefix2netmask "${prefix}")"

		# Calculate the network and broadcast addresses
		local netaddress="${subnet%/*}"

		local index="$(oci_get_interface_param "${id}" "nicIndex")"

		# Set index to zero if it was empty
		if [ -z "${index}" ]; then
			index=0
		fi

		case "${index}" in
			# RED
			0)
				local interface_name="red0"
				local gateway="$(oci_get_interface_param "${id}" "virtualRouterIp")"

				(
					echo "RED_TYPE=STATIC"
					echo "RED_DEV=${interface_name}"
					echo "RED_MACADDR=${mac}"
					echo "RED_DESCRIPTION='${id}'"
					echo "RED_ADDRESS=${ipv4_address}"
					echo "RED_NETMASK=${netmask}"
					echo "RED_NETADDRESS=${netaddress}"
					echo "RED_MTU=1500"
					echo "DEFAULT_GATEWAY=${gateway}"
				) >> /var/ipfire/ethernet/settings

				# Import aliases for RED
				#for alias in $(get "instance/network-interfaces/${device_number}/ip-aliases"); do
				#	echo "${alias},on,"
				#done > /var/ipfire/ethernet/aliases
				;;

			# GREEN
			1)
				local interface_name="green0"

				(
					echo "GREEN_DEV=${interface_name}"
					echo "GREEN_MACADDR=${mac}"
					echo "GREEN_DESCRIPTION='${id}'"
					echo "GREEN_ADDRESS=${ipv4_address}"
					echo "GREEN_NETMASK=${netmask}"
					echo "GREEN_NETADDRESS=${netaddress}"
					echo "GREEN_MTU=${DEFAULT_MTU}"
				) >> /var/ipfire/ethernet/settings
				;;

			# ORANGE
			2)
				local interface_name="orange0"
				config_type=2

				(
					echo "ORANGE_DEV=${interface_name}"
					echo "ORANGE_MACADDR=${mac}"
					echo "ORANGE_DESCRIPTION='${id}'"
					echo "ORANGE_ADDRESS=${ipv4_address}"
					echo "ORANGE_NETMASK=${netmask}"
					echo "ORANGE_NETADDRESS=${netaddress}"
					echo "ORANGE_MTU=${DEFAULT_MTU}"
				) >> /var/ipfire/ethernet/settings
				;;
		esac
	done

	# Save CONFIG_TYPE
	echo "CONFIG_TYPE=${config_type}" >> /var/ipfire/ethernet/settings

	# Actions performed only on the very first start
	if [ ! -e "/var/ipfire/main/firstsetup_ok" ]; then
		# Disable using ISP nameservers
		sed -e "s/^USE_ISP_NAMESERVERS=.*/USE_ISP_NAMESERVERS=off/" -i /var/ipfire/dns/settings

		# Enable SSH
		sed -e "s/ENABLE_SSH=.*/ENABLE_SSH=on/g" -i /var/ipfire/remote/settings

		# Disable SSH password authentication
		sed -e "s/^ENABLE_SSH_PASSWORDS=.*/ENABLE_SSH_PASSWORDS=off/" -i /var/ipfire/remote/settings

		# Enable SSH key authentication
		sed -e "s/^ENABLE_SSH_KEYS=.*/ENABLE_SSH_KEYS=on/" -i /var/ipfire/remote/settings

		# Apply SSH settings
		/usr/local/bin/sshctrl

		# Mark SSH to start immediately (but not right now)
		touch /var/ipfire/remote/enablessh
		chown nobody:nobody /var/ipfire/remote/enablessh

		# Firewall rules for SSH and WEBIF
		(
			echo "1,ACCEPT,INPUTFW,ON,std_net_src,ALL,ipfire,RED1,,TCP,,,ON,,,cust_srv,SSH,,,,,,,,,,,00:00,00:00,,AUTO,,dnat,,,,,second"
			echo "2,ACCEPT,INPUTFW,ON,std_net_src,ALL,ipfire,RED1,,TCP,,,ON,,,TGT_PORT,444,,,,,,,,,,,00:00,00:00,,AUTO,,dnat,,,,,second"
		) >> /var/ipfire/firewall/input

		# Download a startup script
		local script="$(get instance/metadata/user_data)"

		# Try to decode this
		script="$(try_base64_decode "${script}")"

		# Execute the script
		if [ "${script:0:2}" = "#!" ]; then
			echo "${script}" > /tmp/user-data.script
			chmod 700 /tmp/user-data.script

			# Run the script
			local now="$(date -u +"%s")"
			/tmp/user-data.script &>/var/log/user-data.log.${now}

			# Delete the script right away
			rm /tmp/user-data.script
		fi

		# This script has now completed the first steps of setup
		touch /var/ipfire/main/firstsetup_ok
	fi

	# All done
	echo_ok
}

case "${reason}" in
	PREINIT)
		# Bring up the interface
		ip link set "${interface}" up
		;;

	BOUND|RENEW|REBIND|REBOOT)
		# Remove any previous IP addresses
		ip addr flush dev "${interface}"

		# Add (or re-add) the new IP address
		ip addr add "${new_ip_address}/${new_subnet_mask}" dev "${interface}"

		# Add the default route
		ip route add "${new_routers}" dev "${interface}"
		ip route add default via "${new_routers}"

		# Setup DNS
		for domain_name_server in ${new_domain_name_servers}; do
			echo "nameserver ${domain_name_server}"
		done > /etc/resolv.conf

		# The system is online now
		touch /var/ipfire/red/active

		# Import OCI configuration
		import_oci_configuration
		;;

	EXPIRE|FAIL|RELEASE|STOP)
		# The system is no longer online
		rm -f /var/ipfire/red/active

		# Remove all IP addresses
		ip addr flush dev "${interface}"

		# Shut down the interface
		ip link set "${interface}" down
		;;

	*)
		echo "Unhandled reason: ${reason}" >&2
		exit 2
		;;
esac

# Terminate
exit 0
