split_routes

#!/bin/bash

# Check if at least two arguments are provided (action + at least one domain)
if [ $# -lt 2 ]; then
    if [ $# -eq 1 ]; then
    ARGUMENTS="argument"
    else
    ARGUMENTS="arguments"
    fi
    echo "$# $ARGUMENTS found, at least 2 arguments are required"
    echo "Usage: $0 <action> <table> <pref> <domain1> [domain2] [...]"
    echo "action: add, del, refresh"
    echo "Examples: "
    echo "$0 refresh someroutename 60 plex.tv app.plex.tv"
    echo "$0 add someroutename 60 plex.tv app.plex.tv"
    echo "$0 del someroutename"
    exit 1
fi

# Configuration variables
ARGUMENTS=$#                    # Reuse arguments variable to store num arguments
ACTION=$1                       # Action to perform
TABLE=$2                        # Table to route through
PREF=$3                         # Preference for the rules
GATEWAY="192.168.0.1"           # Gateway to route through
LOCAL_NETWORK="192.168.0.0/24"  # Local network to not mark
INTERFACE="eth0"                # Interface to route through
PORT=32400                      # Service port
shift 3                         # Remove the handled arguments, so now it should just be domains left
DOMAINS=("$@")                  # Remaining arguments are treated as domains

# Function to clear existing rules and routes for the table
clearRulesAndRoutes() {
    echo "Clearing existing rules and routes for table $TABLE..."

    sudo iptables -t mangle -D PREROUTING -p tcp --dport $PORT -j MARK --set-mark 1
    sudo iptables -t mangle -D OUTPUT -p tcp --sport $PORT ! -d $LOCAL_NETWORK -j MARK --set-mark 1
    sudo /sbin/ip rule del fwmark 1 table $TABLE

    # Find rules associated with the 'plexroute' table and delete them
    /sbin/ip rule show | grep "lookup $TABLE" | while read -r rule; do
        # Extract the from and to parts
        from=$(echo $rule | grep -oP 'from \S+')
        to=$(echo $rule | grep -oP 'to \S+')
        # Delete the rule, using the extracted parts for specificity
        sudo /sbin/ip rule del $from $to table $TABLE
    done

    # Clear routes from the table
    /sbin/ip route show table $TABLE | while read -r route; do
        sudo /sbin/ip route del $route table $TABLE
    done

}

# Function to add routes and rules for each IP address of a domain
addRoutesAndRules() {
    for domain in "${DOMAINS[@]}"; do
        echo "Processing domain: $domain"

        # Get IP addresses for the domain
        IPs=$(dig +short $domain)

        if [ -z "$IPs" ]; then  # Check if IPs is empty
            echo "No IPs found for domain $domain. Skipping..."
            continue  # Skip to the next domain
        fi
        sudo /sbin/ip route add default via $GATEWAY dev $INTERFACE table $TABLE
        # Add routes and rules for each IP address
        for ip in $IPs; do
            if [[ $ip =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then  # Simple check for IPv4 address
                echo "Adding route and rule for $ip..."
                sudo /sbin/ip rule add to $ip pref $PREF table $TABLE
            else
                echo "Skipping non-IPv4 address: $ip"
            fi
        done
    done

    echo Marking service traffic to avoid it being routed through the vpn
    sudo iptables -t mangle -A PREROUTING -p tcp --dport $PORT -j MARK --set-mark 1
    sudo iptables -t mangle -A OUTPUT -p tcp --sport $PORT ! -d $LOCAL_NETWORK -j MARK --set-mark 1
    sudo /sbin/ip rule add fwmark 1 table $TABLE
}

# Main
case $ACTION in
    add | refresh)
        if [ $# -lt 1 ]; then
            echo "\`$ACTION\` requires at least 4 arguments, $ARGUMENTS found"
            echo "Example: $0 $ACTION someroutename 60 plex.tv app.plex.tv"
	    exit
        fi
	case $ACTION in
	    add)
	        addRoutesAndRules
		;;
	    refresh)
                clearRulesAndRoutes
                addRoutesAndRules
	        ;;
	    *)
		echo "Something weird happened handling \`$ACTION\`"
        esac
	;;
    del)
        clearRulesAndRoutes
        ;;
    *)
        echo "Invalid action \`$ACTION\`specified. Please use 'add', 'del', or 'refresh'."
        exit 1
        ;;
esac