udm-iptvd

#!/bin/sh
# Script for managing the udm-iptv service
#
# Copyright (C) 2021 Fabian Mastenbroek.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# Default options
IPTV_WAN_VLAN_INTERFACE="${IPTV_WAN_VLAN_INTERFACE:-iptv}"
IPTV_WAN_DHCP_OPTIONS="${IPTV_WAN_DHCP_OPTIONS:-"-O staticroutes -V IPTV_RG"}"
IPTV_LAN_RANGES="${IPTV_LAN_RANGES:-""}"

# Use busybox if udhcpc is not installed directly
if ! command -v udhcpc > /dev/null 2>&1; then
    alias udhcpc="busybox udhcpc"
fi

# Setup the network, creating the IPTV VLAN interface if necessary
# and obtaining an IP address for the interface.
_network_setup() {
    local target
    target="$IPTV_WAN_INTERFACE"

    # Make sure we obtain IP address for VLAN interface
    if [ "$IPTV_WAN_VLAN" -gt 0 ]; then
        target="$IPTV_WAN_VLAN_INTERFACE"

        if ! ip link show "$IPTV_WAN_INTERFACE" >/dev/null; then
            echo "Device $IPTV_WAN_INTERFACE for $IPTV_WAN_VLAN_INTERFACE does not exist"
            exit 1
        fi

        # Delete existing VLAN interface
        if [ -e /sys/class/net/"$IPTV_WAN_VLAN_INTERFACE" ]; then
            echo "Device $IPTV_WAN_VLAN_INTERFACE already exists.. Deleting device"
            ip link delete dev "$IPTV_WAN_VLAN_INTERFACE"
        fi

        ip link add link "$IPTV_WAN_INTERFACE" name "$IPTV_WAN_VLAN_INTERFACE" type vlan id "$IPTV_WAN_VLAN"

        # Specify custom MAC address for VLAN interface
        if [ -n "$IPTV_WAN_VLAN_MAC" ]; then
            ip link set dev "$IPTV_WAN_VLAN_INTERFACE" address "$IPTV_WAN_VLAN_MAC"
        fi

        # Bring VLAN interface up
        ip link set dev "$IPTV_WAN_VLAN_INTERFACE" up

        if [ "$IPTV_WAN_DHCP" != "false" ]; then
            echo "Obtaining IP address for VLAN interface"

            # Obtain IP address for VLAN interface
            udhcpc -b -R -p /var/run/udhcpc."$IPTV_WAN_VLAN_INTERFACE".pid -s "$(dirname "$0")"/udhcpc.hook -i "$IPTV_WAN_VLAN_INTERFACE" $IPTV_WAN_DHCP_OPTIONS
        fi
    fi

    if [ "$IPTV_WAN_DHCP" = "false" ] && [ -n "$IPTV_WAN_STATIC_IP" ]; then
        ip -4 addr change "$IPTV_WAN_STATIC_IP" dev "$target"
    fi

    echo "NATing IPTV network ranges (if necessary)"

    # NAT the IPTV ranges
    for range in $IPTV_WAN_RANGES; do
        # Only add the NAT rule if it does not yet exist
        if ! iptables -C POSTROUTING -t nat -d "$range" -j MASQUERADE -o "$target" >/dev/null 2>&1; then
            iptables -A POSTROUTING -t nat -d "$range" -j MASQUERADE -o "$target"
        fi
    done

    echo "Creating static routes (if necessary)"
    for range in $IPTV_STATIC_ROUTES; do
        ip route add "$range" dev "$target"
    done
}

# Watch for network changes and re-apply the configuration
_network_watch() {
    if [ "$IPTV_WAN_VLAN" -gt 0 ]; then
        return
    fi

    echo "Monitoring interface $IPTV_WAN_INTERFACE for changes"

    # Monitor for changes on the WAN interface
    ip monitor address dev "$IPTV_WAN_INTERFACE" | while read line; do
        if echo "$line" | grep -q "Deleted"; then
            _network_setup
        fi
    done & # Monitoring happens in background
}

# Tear down the network configuration
_network_teardown() {
    # Delete the IPTables rules
    for range in $IPTV_WAN_RANGES; do
        iptables -D POSTROUTING -t nat -d "$range" -j MASQUERADE -o "$target" >/dev/null 2>&1
    done
}

# Build the configuration needed by IGMP Proxy
_igmpproxy_build_config() {
    echo "# igmpproxy configuration for udm-iptv"
    if [ -z "$IPTV_IGMPPROXY_DISABLE_QUICKLEAVE" ] || [ "$IPTV_IGMPPROXY_DISABLE_QUICKLEAVE" = "false" ]; then
        echo "quickleave"
    fi

    local target
    if [ "$IPTV_WAN_VLAN" -gt 0 ]; then
        target="$IPTV_WAN_VLAN_INTERFACE"
    else
        target="$IPTV_WAN_INTERFACE"
    fi

    echo "phyint $target upstream  ratelimit 0  threshold 1"
    for range in $IPTV_LAN_RANGES $IPTV_WAN_RANGES; do
        echo "  altnet $range"
    done

    # Configure the igmpproxy interfaces
    for path in /sys/class/net/*; do
        local interface
        interface=$(basename "$path")
        if echo "$IPTV_LAN_INTERFACES" | grep -w -q "$interface"; then
            echo "phyint $interface downstream  ratelimit 0  threshold 1"
        elif [ "$interface" != "lo" ] && [ "$interface" != "$target" ]; then
            echo "phyint $interface disabled"
        fi
    done
}

# Build the configuration needed by IMProxy
_igmpproxy_build_config_improxy() {
    echo "# improxy configuration for udm-iptv"
    if [ "$IPTV_IGMPPROXY_IGMP_VERSION" = 3 ]; then
        echo "igmp enable version 3"
    else
        echo "igmp enable version 2"
    fi

    echo "mld disable"

    local target
    if [ "$IPTV_WAN_VLAN" -gt 0 ]; then
        target="$IPTV_WAN_VLAN_INTERFACE"
    else
        target="$IPTV_WAN_INTERFACE"
    fi

    echo "upstream $target"

    # Configure the upstream interfaces
    for path in /sys/class/net/*; do
        local interface
        interface=$(basename "$path")
        if echo "$IPTV_LAN_INTERFACES" | grep -w -q "$interface"; then
            echo "downstream $interface"
        fi
    done
}

# Configure IGMP Proxy to bridge multicast traffic
_igmpproxy_setup() {
    echo "Setting up IGMP Proxy"

    if [ "$IPTV_IGMPPROXY_PROGRAM" = "improxy" ]; then
        echo "Using improxy..."
        _igmpproxy_build_config_improxy > /var/run/igmpproxy.iptv.conf
    else
        echo "Using igmpproxy..."
        _igmpproxy_build_config > /var/run/igmpproxy.iptv.conf
    fi
}

# Tear down the IGMP Proxy configuration
_igmpproxy_teardown() {
    rm -f /var/run/igmpproxy.iptv.conf
}

# Start the igmpproxy service
_igmpproxy_start() {
    echo "Starting IGMP Proxy"
    args=""
    if [ -n "$IPTV_IGMPPROXY_DEBUG" ] && [ "$IPTV_IGMPPROXY_DEBUG" != "false" ]; then
        if [ "$IPTV_IGMPPROXY_PROGRAM" = "improxy" ]; then
            args="-d 5"
        else
            args="-d -v"
        fi
    fi

    if [ "$IPTV_IGMPPROXY_PROGRAM" = "improxy" ]; then
        if ! command -v improxy > /dev/null 2>&1; then
            echo "error: improxy not installed..."
            exit 1
        fi

        # shellcheck disable=SC2086
        exec improxy $args "$@" -c /var/run/igmpproxy.iptv.conf
    else
        if ! command -v igmpproxy > /dev/null 2>&1; then
            echo "error: igmpproxy not installed..."
            exit 1
        fi

        # shellcheck disable=SC2086
        exec igmpproxy -n $args "$@" /var/run/igmpproxy.iptv.conf
    fi
}


# Check if the user passed any argument
if [ $# -eq 0 ]; then
    exit 1
fi

case $1 in
    start)
        shift
        _network_setup
        _network_watch
        _igmpproxy_setup
        _igmpproxy_start "$@"
        ;;
    stop)
        shift
        _network_teardown
        _igmpproxy_teardown
        ;;
    *)
        exit 1
        ;;
esac