#!/bin/bash

. /etc/functions

TRACE_FUNC

# bring up the ethernet interface
ifconfig lo 127.0.0.1

echo "Loading Ethernet network modules..."
network_modules="e1000 e1000e igb sfc mdio mlx4_core mlx4_en"
for module in $(echo $network_modules); do
	if [ -f /lib/modules/$module.ko ]; then
		#check if module is already loaded and load it if not
		lsmod | grep -q $module || insmod /lib/modules/$module.ko
	fi
done

#Tethering over USB for Mobile phones supporting CDC (Android Pixel 6a+, Librem phone, etc.)
if [ -e /lib/modules/cdc_ether.ko ]; then
	#first enable USB controllers
	enable_usb
	echo ""
	echo "Please verify that your mobile (CDC NCM/EEM tethering compatible phone) is networked in the desired way (WIFI/mobile + VPN/Orbot/etc)"
	echo "Please connect mobile phone to this machine's fast USB port (blue identified) through a known working data cable"
	echo "Please enable USB tethering prior of going further (Android: select 'Charging this device via USB' notification and enable tethering option)"
	read -p "Press Enter to continue now or wait 30 seconds..." -n 1 -r -t 30
	
	network_modules="mii usbnet cdc_ether cdc_ncm cdc_eem"
	echo "Loading USB tethering network related modules: $network_modules..."
	for module in $(echo $network_modules); do
		if [ -f /lib/modules/$module.ko ]; then
			#check if module is already loaded and load it if not
			lsmod | grep -q $module || insmod /lib/modules/$module.ko
		fi
	done
	if ! [ -e /sys/class/net/usb0 ]; then
		echo ""
		echo "Tethering USB network interface was NOT detected with loaded kernel modules : $network_modules"
		echo "Please check your phone's linux drivers requirements"
		echo "Note that RNDIS kernel module inclusion was discussed and rejected due to security implications and planned deprecation under Linux kernel altogether"
		echo "CDC NCM/CDC EEM support is known to be available on a majority of Android/GrapheneOS as well as Librem phones"
		echo "Non-exhaustive exeptions: Pixel 4a* known to only tether over RNDIS and won't be supported"
		echo "Apple phones won't be supported due to size and complexity of the drivers and toolstack required to support tethering"
		read -p "Press Enter to continue now or wait 30 seconds..." -n 1 -r -t 30
	fi
fi

if [ -e /sys/class/net/usb0 ]; then
	dev=usb0
	echo "USB tethering network interface detected as $dev"
elif [ -e /sys/class/net/eth0 ]; then
	dev=eth0
	echo "Ethernet network interface detected as $dev"
	#Randomize eth0 MAC address of maximized boards
	if echo "$CONFIG_BOARD" | grep -q maximized; then
		ifconfig $dev down
		echo "Generating random MAC address..."
		mac=$(generate_random_mac_address)
		echo "Assigning randomly generated MAC: $mac to eth0..."
		ifconfig $dev hw ether $mac
		echo "Bringing up $dev... Connect a network cable to the $dev port and make sure status LEDs are on"
		ifconfig $dev up
	fi
fi

# Set up static IP
if [ ! -z "$CONFIG_BOOT_STATIC_IP" ]; then
	echo "Setting static IP: $CONFIG_BOOT_STATIC_IP"
	ifconfig $dev $CONFIG_BOOT_STATIC_IP
	echo "No NTP sync with static IP: no DNS server nor gateway defined, set time manually"
elif [ -e /sbin/udhcpc ]; then
	echo "Getting IP from first DHCP server answering. This may take a while..."
	if udhcpc -T 1 -i $dev -q; then
		if [ -e /sbin/ntpd ]; then
			DNS_SERVER=$(grep nameserver /etc/resolv.conf | awk -F " " {'print $2'})
			killall ntpd 2 &>1 >/dev/null
			echo "Attempting to sync time with NTP server: $DNS_SERVER..."
			if ! ntpd -d -N -n -q -p $DNS_SERVER; then
				echo "NTP sync unsuccessful with DNS server"
			       	echo "Attempting NTP time sync with pool.ntp.org..."
				if ! ntpd -d -d -N -n -q -p pool.ntp.org; then
					echo "NTP sync unsuccessful."
				else
					echo "NTP time sync successful."
				fi
			fi
			echo "Syncing hardware clock with system time in UTC/GMT timezone... NOT LOCAL TIMEZONE!"
			hwclock -w
			echo ""
			date=$(date "+%Y-%m-%d %H:%M:%S %Z")
			echo "Time: $date"
		fi
	fi
fi

if [ -e /bin/dropbear ]; then
	# Set up the ssh server, allow root logins and log to stderr
	if [ ! -d /etc/dropbear ]; then
		mkdir /etc/dropbear
	fi
	echo "Starting dropbear ssh server..."
	dropbear -B -R
fi
echo ""
echo "Network setup complete:"
ifconfig