#!/bin/sh
# Copyright 2018 Intel Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#	http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

SOFS_MNT=/var/sofs
SOFS_MACDIR=${SOFS_MNT}/factory-settings/network/mac

read_hw_mac() {
	local iface="$1"
	cat /sys/class/net/"$iface"/address 2>/dev/null | tr [:upper:] [:lower:] 2>/dev/null
}

set_hw_mac() {
	local iface="$1"
	local mac="$2"
	ip link show dev "$iface" | grep -q "${iface}:.*\<UP\>" 2>/dev/null
	local up=$?
	[[ $up -eq 0 ]] && ip link set dev "$iface" down
	ip link set dev "$iface" address "$mac"
	[[ $up -eq 0 ]] && ip link set dev "$iface" up
}

read_sofs_mac() {
	local iface="$1"
	cat "${SOFS_MACDIR}/${iface}" 2>/dev/null | tr [:upper:] [:lower:] 2>/dev/null
}

read_fw_env_mac() {
	local envname="$1"
	fw_printenv "$envname" 2>/dev/null | sed "s/^$envname=//" 2>/dev/null | tr [:upper:] [:lower:] 2>/dev/null
}

set_fw_env_mac() {
	local envname="$1"
	local mac="$2"
	fw_setenv "$envname" "$mac"
}

create_macdir() {
if [ -a ${SOFS_MACDIR} ]; then
	if [ ! -d ${SOFS_MACDIR} ]; then
		rm -rf ${SOFS_MACDIR}
		mkdir -p ${SOFS_MACDIR}
	fi
else
	mkdir -p ${SOFS_MACDIR}
fi
return 0
}

mac_check() {
	local iface="$1"
	local envname="$2"

	# Read the MAC address in use by the NIC
	local hw_mac=$(read_hw_mac "$iface")

	# Read the MAC address stored in the non-volatile file provisioned in
	# manufacturing.
	local sofs_mac=$(read_sofs_mac "$iface")

	if [ -n "$sofs_mac" ] && [ "$hw_mac" != "$sofs_mac" ]; then
		# A factory assigned address was found, and it is newly assigned.
		# Update the active interface and save the new value to the u-boot
		# environment.
		set_hw_mac "$iface" "$sofs_mac"
		set_fw_env_mac "$envname" "$sofs_mac"
		return $?
	elif [ -n "$hw_mac" ]; then
		# Read the MAC address stored by U-Boot
		local fw_env_mac=$(read_fw_env_mac "$envname")
		if [ -z "$fw_env_mac" ] || [ "$fw_env_mac" != "$hw_mac" ]; then
			set_fw_env_mac "$envname" "$hw_mac"
			return $?
		fi
	else
	    # Could not identify a MAC address
	    return 255
	fi
	return 0
}

create_macdir

error=0
first_error_seen=0

while read IFACE UBDEV; do
	# Try to configure the MAC address if the kernel finds the NIC. Blindly
	# trying all of the interfaces listed in the DOCSTRING (END_CONF) below
	# may result in first_error_seen being set to a non-zero value. If that
	# happens the journal log will report the error, which is undesirable.
	if [ -h /sys/class/net/$IFACE ]; then
		mac_check "$IFACE" "$UBDEV"
		error=$?
		if [ $error -ne 0 ] && [ $first_error_seen -eq 0 ]; then
		    first_error_seen=$error
		fi
	fi
done <<-END_CONF
	eth0 eth1addr
	eth1 ethaddr
END_CONF
exit $first_error_seen