route-add

#!/bin/bash
trap "exit 1" TERM
export TOP_PID=$$

DOMAIN=$1
GW_DEV=$2
GW_IP=$3

bye()
{
	kill -s TERM $TOP_PID
}

askDevice ()
{
	while true; do
		echo "Select Device:"
		mapfile -t dev_list < <(ifconfig -s | cut -f1 -d ' ' | grep -v Iface)
		for i in "${!dev_list[@]}"; do
			printf "[%d]\t%s\n" "$i" "${dev_list[$i]}"
		done
		echo "---------------------------------------------"
		echo -n "Device number: "
		read dev_index
		if [ -z "${dev_list[${dev_index}]}" ]; then
			echo -e "\n\tInvalid device"
		else
			GW_DEV=${dev_list[$dev_index]}
			break
		fi
	done
}

getGatewayIp()
{
	echo $(ip route sh | grep "$1" | grep "default" | cut -d ' ' -f3)
}

getGatewayMetric()
{
	METRIC=""
	F8=$(ip route sh | grep "$1" | grep "default" | cut -d ' ' -f8)
	if [ "$F8" == "metric" ]; then
		METRIC=$(ip route sh | grep "$1" | grep "default" | cut -d ' ' -f9)
	fi
	echo "$METRIC"
}

getDomainIp()
{
	echo $(getent hosts ${DOMAIN} | awk '{print $1}')
}

setDomainRoutes()
{
	if [ -z "$4" ]; then
		getent hosts $1 | awk '{print $1}' | xargs -i{} sudo ip route replace {} via $2 dev $3
	else
		getent hosts $1 | awk '{print $1}' | xargs -i{} sudo ip route replace {} via $2 dev $3 metric $4
	fi
}

if [ -z "$DOMAIN" ]; then
	echo -e "\tDomain is not given!"
	bye
fi

DOMAIN_IP=$(getDomainIp)
echo -e "Domain: ${DOMAIN}\t (${DOMAIN_IP})"

if [ -z "$GW_DEV" ]; then
	askDevice
fi
echo -e "Device: ${GW_DEV}"

if [ -z "$GW_IP" ]; then
	ip=$(getGatewayIp $GW_DEV)
    if [ "$ip" == "$GW_DEV" ]; then
		echo -e "\tThis is your default out going traffic route!"
		echo -e "\tYour route to ${DOMAIN} is already passed via this gateway"
		bye
	else
		GW_IP=${ip}
	fi
fi

GW_METRIC=$(getGatewayMetric $GW_DEV)

echo "Gateway IP: ${GW_IP}"
if [ -z "$GW_IP" ]; then
	setDomainRoutes ${DOMAIN} ${GW_IP} ${GW_DEV}
else
	echo "Gateway Metric: ${GW_METRIC}"
	setDomainRoutes ${DOMAIN} ${GW_IP} ${GW_DEV} ${GW_METRIC}
fi

echo "Routes Added."