#!/bin/bash

. /usr/lib/network/functions

# Configure logging
LOG_FACILITY="dhclient-script"

network_settings_read

assert isset interface
assert isset reason

assert device_exists ${interface}

basename="$(basename $0)"
log DEBUG "${basename} called for interface=${interface} reason=${reason}"

# Log all information from dhclient
if enabled DEBUG; then
	while read line; do
		[[ ${line} =~ ^(cur|old|new)_ ]] || continue
		log DEBUG "  ${line}"
	done <<< "$(printenv | sort)"
fi

# Main pitchfork.
case "${reason}" in
	MEDIUM)
		# Linux does not handle MEDIUM.
		exit 0
		;;

	# IPv6

	PREINIT6)
		if ! device_is_up "${interface}"; then
			log WARNING "Device '${interface}' was not brought up before starting the DHCP client"
			device_set_up "${interface}"
		fi

		# Flush all other aborted IP addresses
		ipv6_address_flush "${interface}"

		# Disable autoconf because DHCP is handling this
		ipv6_device_autoconf_disable "${interface}"

		# Enable forwarding because we are acting as a host
		# to uplink network zones.
		ipv6_device_forwarding_enable "${interface}" --accept-ra

		# Wait until DAD for the link-local address has finished
		for address in $(ipv6_device_get_addresses "${interface}" --scope="link"); do
			ipv6_wait_for_dad "${address}" "${interface}" && exit ${EXIT_OK}
		done

		log ERROR "There is no active link-local address on ${interface}"

		exit ${EXIT_ERROR}
		;;

	BOUND6)
		# We will be called twice. Once for the assigned address and once for an assigned prefix.

		# Handle temporarily-assigned address
		if isset new_ip6_address && isset new_ip6_prefixlen; then
			ipv6_address_add "${new_ip6_address}/${new_ip6_prefixlen}" "${interface}" \
				--valid-lifetime="${new_max_life}" --preferred-lifetime="${new_preferred_life}"

			# Save configuration
			db_set "${interface}/ipv6/local-ip-address" "${new_ip6_address}/${new_ip6_prefixlen}"
			db_set "${interface}/ipv6/active" 1
			#db_set "${interface}/ipv6/domain-name" "${new_

			# Update the routing tables
			routing_update "${interface}" ipv6

			exit 0

		# Handle Prefix Delegation
		elif isset new_ip6_prefix; then
			db_set "${interface}/ipv6/delegated-prefix" "${new_ip6_prefix}"

			exit 0
		fi
		;;

	RENEW6|REBIND6)
		# Will be called twice like BOUND6.

		if isset new_ip6_address && isset new_ip6_prefixlen; then
			# Update nameservers if those have changed
			if [[ "${old_dhcp6_name_servers}" != "${new_dhcp6_name_servers}" ]]; then
				db_set "${interface}/ipv6/domain-name-servers" "${new_dhcp6_name_servers}"
				dns_server_update
			fi

			# Update the lifetime if the address has not changed
			if [[ "${old_ip6_address}" = "${new_ip6_address}" ]]; then
				ipv6_address_change_lifetime "${new_ip6_address}/${new_ip6_prefixlen}" "${interface}" \
					--valid-lifetime="${new_max_life}" --preferred-lifetime="${new_preferred_life}"

				exit ${EXIT_OK}
			fi

			# Remove any old IP addresses
			if [ -n "${old_ip6_address}" ]; then
				ipv6_address_del "${old_ip6_address}/${old_ip6_prefixlen}" "${interface}"
			fi

			# Update the database
			db_set "${interface}/ipv6/local-ip-address" \
				"${new_ip6_address}/${new_ip6_prefixlen}"

			# Add the new one
			ipv6_address_add "${new_ip6_address}/${new_ip6_prefixlen}" "${interface}" \
				--valid-lifetime="${new_max_life}" --preferred-lifetime="${new_preferred_life}"

			# Update the routing tables
			routing_update "${interface}" ipv6

			exit ${EXIT_OK}

		# Handle Prefix Delegation
		elif isset new_ip6_prefix || isset old_ip6_prefix; then
			if [[ "${old_ip6_prefix}" = "${new_ip6_prefix}" ]]; then
				# TODO What do we need to do if the prefix hasn't changed?
				exit ${EXIT_OK}
			fi

			log DEBUG "The delegated prefix has changed from ${old_ip6_prefix} to ${new_ip6_prefix}"
			db_set "${interface}/ipv6/delegated-prefix" "${new_ip6_prefix}"

			exit ${EXIT_OK}
		fi
		;;

	DEPREF6)
		# Check if all necessary information is there
		if ! isset cur_ip6_address || ! isset cur_ip6_prefixlen; then
			exit ${EXIT_ERROR}
		fi

		# Set lifetime to zero
		ipv6_address_change_lifetime "${cur_ip6_address}/${cur_ip6_prefixlen}" "${interface}" \
			--preferred-lifetime=0 || exit ${EXIT_ERROR}
		;;

	EXPIRE6|FAIL6|RELEASE6|STOP6)
		# Remove the currently configured addresses from the device.
		ipv6_address_flush "${interface}"

		# Reset autoconf mode and disable forwarding
		ipv6_device_forwarding_disable "${interface}"
		ipv6_device_autoconf_disable "${interface}"

		db_delete "${interface}/ipv6"

		exit 0
		;;

	# IPv4

	PREINIT)
		# Bring up the device if it hasn't been done before.
		if ! device_is_up ${interface}; then
			log DEBUG "The interface '${interface}' does not appear to be up."

			zone_up ${interface}
		fi

		# We will try to detect is STP has brought the bridge up
		if device_is_bridge ${interface}; then
			counter=60

			while [ ${counter} -gt 0 ]; do
				# We may end this, when the bridge is in forwarding mode.
				if bridge_is_forwarding ${interface}; then
					log DEBUG "Bridge '${interface}' is in forwarding mode."
					break
				fi

				counter=$(( ${counter} - 1 ))
				sleep 1
			done

			# Tell the daemon, that we are not ready to go on.
			if [ ${counter} -eq 0 ]; then
				log ERROR "Bridge '${interface}' is not in forwarding mode."
				log ERROR "Could not go on with getting a DHCP lease. Exiting."

				exit 1
			fi
		fi

		exit 0
		;;

	BOUND|RENEW|REBIND|REBOOT)
		# Check if the IP address has changed. If so, delete all routes and stuff.
		if [ -n "${old_ip_address}" -a "${old_ip_address}" != "${new_ip_address}" ] || \
			[ "${reason}" = "BOUND" ]; then
			ipv4_flush_device ${interface}
		fi

		case "${reason}" in
			BOUND|REBIND|REBOOT)
				if [ ! "${old_ip_address}" = "${new_ip_address}" ] || \
					[ ! "${old_subnet_mask}" = "${new_subnet_mask}" ] || \
					[ ! "${old_network_number}" = "${new_network_number}" ] || \
					[ ! "${old_broadcast_address}" = "${new_broadcast_address}" ] || \
					[ ! "${old_routers}" = "${new_routers}" ] || \
					[ ! "${old_interface_mtu}" = "${new_interface_mtu}" ] || \
					[ "${reason}" = "BOUND" ]; then


					# Calc the prefix from the subnet mask
					new_prefix="$(ipv4_netmask2prefix "${new_subnet_mask}")"

					# Set the new ip address.
					ip_address_add "${interface}" "${new_ip_address}/${new_prefix}"

					# A MTU of 576 is used for X.25 and dialup connections. Some broken DHCP
					# servers send out an MTU of 576 bytes, which will be ignored.
					if [ -n "${new_interface_mtu}" ] && [ ${new_interface_mtu} -gt 576 ]; then
						device_set_mtu ${interface} ${new_interface_mtu}
					fi

					# Save configuration
					db_set "${interface}/ipv4/type" "ipv4-dhcp"
					db_set "${interface}/ipv4/local-ip-address" \
						"${new_ip_address}/${new_prefix}"
					db_set "${interface}/ipv4/remote-ip-address" "${new_routers}"
					db_set "${interface}/ipv4/active" 1
					db_set "${interface}/ipv4/domain-name" "${new_domain_name}"
					db_set "${interface}/ipv4/domain-name-servers" \
						"${new_domain_name_servers}"
					db_set "${interface}/ipv4/domain-name-servers-priority" \
						"${DNS_SERVER_DYNAMIC_PRIORITY}"

					# Update the routing tables.
					routing_update ${interface} ipv4
					routing_default_update

					# Update DNS configuration
					dns_server_update
				fi
				;;
		esac

		exit 0
		;;

	EXPIRE|FAIL|RELEASE|STOP)
		# Remove the currently configured addresses from the device.
		if [ -n "${old_ip_address}" ]; then
			ipv4_flush_device ${interface}
		fi

		db_delete "${interface}/ipv4"
		routing_default_update

		exit 0
		;;

	*)
		log ERROR "Unhandled reason: ${reason}"
		;;
esac

exit 1