#!/bin/bash
#  _____               _           _
# |   __|___ ___ ___ _| |___ _____| |_ ___ ___ ___
# |   __|  _| -_| -_| . | . |     | . | . |   | -_|
# |__|  |_| |___|___|___|___|_|_|_|___|___|_|_|___|
#
#                              Freedom in the Cloud
#
# Used to enable or disable batman mesh protocol on a given interface
#
# License
# =======
#
# Copyright (C) 2015-2018 Bob Mottram <bob@freedombone.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

PROJECT_NAME='freedombone'
COMPLETION_FILE="/root/${PROJECT_NAME}-completed.txt"

# hotspot passphrase must be 5 characters or longer
HOTSPOT_PASSPHRASE="${PROJECT_NAME}"

# The type of interface which the mesh will run on
MESH_INTERFACE_TYPE='wlan'

source /usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-wifi
source /usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-mesh

function status {
    batctl o

    if grep -q "bmx6" "$MESH_CURRENT_PROTOCOL"; then
        bmx6 -c show=originators
    fi
    if grep -q "bmx7" "$MESH_CURRENT_PROTOCOL"; then
        bmx7 -c show=originators
    fi
}

function stop {
    if [ ! -f "$MESH_CURRENT_PROTOCOL" ]; then
        return
    fi

    if [ -z "$IFACE" ]; then
        echo 'error: unable to find wifi interface, not enabling batman-adv mesh'
        return
    fi

    systemctl stop bmx6
    if [ -d /etc/bmx7 ]; then
        systemctl stop bmx7
    fi
    systemctl stop olsr2
    systemctl stop babel
    systemctl disable bmx6
    systemctl disable bmx7
    systemctl disable olsr2
    systemctl disable babel
    systemctl stop dnsmasq
    systemctl disable dnsmasq

    # shellcheck disable=SC2153
    if [ "$EIFACE" ]; then
        if [[ "$EIFACE" != "$IFACE" ]] ; then
            brctl delif "$BRIDGE" bat0
            ifconfig "$BRIDGE" down || true
            ethernet_connected=$(cat "/sys/class/net/$EIFACE/carrier")
            if [[ "$ethernet_connected" != "0" ]]; then
                systemctl stop hostapd
                brctl delif "$BRIDGE" "$EIFACE"
                ifconfig "$EIFACE" down -promisc
            fi
            brctl delbr "$BRIDGE"
        fi
    fi

    ifconfig bat0 down -promisc

    batctl if del "$IFACE"
    ifconfig "$IFACE" mtu 1500
    ifconfig "$IFACE" down
    if [[ "$MESH_INTERFACE_TYPE" == 'wlan'* ]]; then
        iwconfig "$IFACE" mode managed
    fi

    if [ "$IFACE_SECONDARY" ]; then
        systemctl stop hostapd
        systemctl disable hostapd
        batctl if del "$IFACE_SECONDARY"
        ifconfig "$IFACE_SECONDARY" mtu 1500
        ifconfig "$IFACE_SECONDARY" down
        if [[ "$MESH_INTERFACE_TYPE" == 'wlan'* ]]; then
            iwconfig "$IFACE_SECONDARY" mode managed
        fi
    fi

    rmmod batman-adv

    disable_mesh_firewall

    systemctl restart network-manager

    if [ -f "$MESH_CURRENT_PROTOCOL" ]; then
        rm "$MESH_CURRENT_PROTOCOL"
    fi
}

function verify {
    tempfile="$(mktemp)"
    batctl o > "$tempfile"
    if grep -q "disabled" "$tempfile"; then
        echo $'B.A.T.M.A.N. not enabled'
        rm "$tempfile"
        stop
        exit 726835
    fi
    echo $'B.A.T.M.A.N. is running'
    rm "$tempfile"
}

function add_wifi_interface {
    ifname=$1
    ifssid=$WIFI_SSID
    if [ "$2" ]; then
        ifssid=$2
    fi
    ifmode=ad-hoc
    if [ "$3" ]; then
        ifmode=$3
    fi
    ifchannel=$CHANNEL
    if [ "$4" ]; then
        ifchannel=$4
    fi

    ifconfig "$ifname" down
    ifconfig "$ifname" mtu 1532
    peermac=$(assign_peer_address)
    if [ ! "$peermac" ]; then
        echo $"Unable to obtain MAC address for $peermac on $ifname"
        return
    fi
    ifconfig "$ifname" hw ether "$peermac"
    echo $"$ifname assigned MAC address $peermac"
    if [[ "$MESH_INTERFACE_TYPE" == 'wlan'* ]]; then
        iwconfig "$ifname" enc off
        iwconfig "$ifname" mode "$ifmode" essid "$ifssid" channel "$ifchannel"
    fi

    batctl if add "$ifname"
    ifconfig "$ifname" up
}

# shellcheck disable=SC2120
function start {
    update_wifi_adaptors "${MESH_INTERFACE_TYPE}"

    if [ -z "$IFACE" ] ; then
        echo 'error: unable to find wifi interface, not enabling batman-adv mesh'
        exit 723657
    fi
    echo "info: enabling batman-adv mesh network $WIFI_SSID on $IFACE"

    stop
    systemctl stop network-manager
    sleep 5

    systemctl stop dnsmasq
    systemctl disable dnsmasq

    # remove an avahi service which isn't used
    if [ -f /etc/avahi/services/udisks.service ]; then
        sudo rm /etc/avahi/services/udisks.service
    fi

    global_rate_limit

    # Might have to re-enable wifi
    rfkill unblock "$(rfkill list|awk -F: "/phy/ {print $1}")" || true

    secondary_wifi_available=
    if [[ "$MESH_INTERFACE_TYPE" == 'wlan'* ]]; then
        if [ "$IFACE_SECONDARY" ]; then
            if [[ "$IFACE" != "$IFACE_SECONDARY" ]]; then
                if [ -d /etc/hostapd ]; then
                    if [ ${#HOTSPOT_PASSPHRASE} -gt 4 ]; then
                        secondary_wifi_available=1
                    else
                        echo $'Hotspot passphrase is too short'
                    fi
                fi
            fi
        fi
    fi

    modprobe batman-adv

    # avahi on ipv6
    sed -i 's|use-ipv4=.*|use-ipv4=no|g' /etc/avahi/avahi-daemon.conf
    sed -i 's|use-ipv6=.*|use-ipv6=yes|g' /etc/avahi/avahi-daemon.conf

    # set the wifi interface for layer 3 routing
    sed -i "s|ExecStart=.*|ExecStart=/usr/sbin/bmx6 dev=${IFACE}|g" /etc/systemd/system/bmx6.service
    sed -i "s|ExecStart=.*|ExecStart=/usr/sbin/bmx7 dev=${IFACE}|g" /etc/systemd/system/bmx7.service
    sed -i "s|ExecStart=.*|ExecStart=/usr/local/sbin/olsrd2_static ${IFACE}|g" /etc/systemd/system/olsr2.service
    sed -i "s|ExecStart=.*|ExecStart=/usr/local/bin/babeld ${IFACE}|g" /etc/systemd/system/babel.service
    systemctl daemon-reload

    add_wifi_interface "$IFACE" "$WIFI_SSID" ad-hoc "$CHANNEL"

    # NOTE: Don't connect the secondary wifi device. hostapd will handle that by itself

    ifconfig bat0 up promisc

    brctl addbr "$BRIDGE"
    brctl addif "$BRIDGE" bat0
    ifconfig bat0 0.0.0.0
    ethernet_connected='0'
    if [ "$EIFACE" ] ; then
        if [[ "$EIFACE" != "$IFACE" ]] ; then
            ethernet_connected=$(cat "/sys/class/net/$EIFACE/carrier")
            if [[ "$ethernet_connected" != "0" ]]; then
                echo $'Trying ethernet bridge to the internet'
                brctl addif "$BRIDGE" "$EIFACE"
                ifconfig "$EIFACE" 0.0.0.0
                ifconfig "$EIFACE" up promisc
                echo $'End of internet bridge'

                # set the wifi interfaces for layer 3 routing
                sed -i "s|ExecStart=.*|ExecStart=/usr/sbin/bmx6 dev=${IFACE} dev=${EIFACE}|g" /etc/systemd/system/bmx6.service
                sed -i "s|ExecStart=.*|ExecStart=/usr/sbin/bmx7 dev=${IFACE} dev=${EIFACE}|g" /etc/systemd/system/bmx7.service
                sed -i "s|ExecStart=.*|ExecStart=/usr/local/sbin/olsrd2_static ${IFACE} ${EIFACE}|g" /etc/systemd/system/olsr2.service
                sed -i "s|ExecStart=.*|ExecStart=/usr/local/bin/babeld ${IFACE} ${EIFACE}|g" /etc/systemd/system/babel.service
                systemctl daemon-reload
            else
                echo $"$EIFACE is not connected"
            fi
        fi
    fi
    ifconfig "$BRIDGE" up
    dhclient "$BRIDGE"

    enable_mesh_seconary_wifi

    enable_mesh_firewall

    enable_mesh_scuttlebot
    enable_mesh_tor

    sed -i "s|server_name .*|server_name ${HOSTNAME}.local;|g" /etc/nginx/sites-available/git_ssb

    systemctl restart nginx

    if [ ! -f "$MESH_DEFAULT_PROTOCOL" ]; then
        echo 'bmx6' > "$MESH_DEFAULT_PROTOCOL"
    fi

    if grep -q "bmx6" "$MESH_DEFAULT_PROTOCOL"; then
        systemctl enable bmx6
        systemctl restart bmx6
        sed -i 's|<type>.*|<type>_bmx6._tcp</type>|g' /etc/avahi/services/routing.service
    fi

    if grep -q "bmx7" "$MESH_DEFAULT_PROTOCOL"; then
        systemctl enable bmx7
        systemctl restart bmx7
        sed -i 's|<type>.*|<type>_bmx7._tcp</type>|g' /etc/avahi/services/routing.service
    fi

    if grep -q "olsr" "$MESH_DEFAULT_PROTOCOL"; then
        IFACE=$(grep ExecStart "/etc/systemd/system/olsr2.service" | awk -F ' ' '{print $2}')
        mesh_generate_ipv6_address "$IFACE"

        systemctl enable olsr2
        systemctl restart olsr2
        sed -i 's|<type>.*|<type>_olsr2._tcp</type>|g' /etc/avahi/services/routing.service
    fi

    if grep -q "babel" "$MESH_DEFAULT_PROTOCOL"; then
        IFACE=$(grep ExecStart /etc/systemd/system/babel.service | awk -F ' ' '{print $2}')
        mesh_generate_ipv6_address "$IFACE"

        systemctl enable babel
        systemctl restart babel
        sed -i 's|<type>.*|<type>_babel._tcp</type>|g' /etc/avahi/services/routing.service
    fi

    systemctl restart avahi-daemon

    verify

    cat "$MESH_DEFAULT_PROTOCOL" > "$MESH_CURRENT_PROTOCOL"
}

function monitor {
    if [[ "$MESH_INTERFACE_TYPE" != 'wlan'* ]]; then
        return
    fi
    if [ -z "$IFACE" ] ; then
        echo 'error: unable to find wifi interface, not enabling batman-adv mesh'
        exit 723657
    fi

    clear
    echo ''
    echo $'*** Stopping network ***'
    echo ''

    stop

    echo "info: monitoring mesh network $WIFI_SSID on $IFACE"

    systemctl stop network-manager
    sleep 5

    clear
    echo ''
    echo $'*** Setting firewall rate limit ***'
    echo ''

    global_rate_limit

    clear
    echo ''
    echo $'*** Enabling wifi adaptor in monitor mode ***'
    echo ''

    # Might have to re-enable wifi
    rfkill unblock "$(rfkill list|awk -F: "/phy/ {print $1}")" || true

    ifconfig "$IFACE" down
    ifconfig "$IFACE" mtu 1532
    ifconfig "$IFACE" hw ether "$(assign_peer_address)"
    iwconfig "$IFACE" enc off
    iwconfig "$IFACE" mode monitor channel "$CHANNEL"
    sleep 1
    iwconfig "$IFACE" ap "$CELLID"

    modprobe batman-adv
    batctl if add "$IFACE"
    ifconfig "$IFACE" up

    horst -i "$IFACE"

    clear
    echo ''
    echo $'*** Restarting the network daemon. This may take a while. ***'
    echo ''

    # shellcheck disable=SC2119
    start
}

# optionally a file can contain the mesh interface type
mesh_interface_type_file=/root/.mesh_interface_type
if [ -f "$mesh_interface_type_file" ]; then
    MESH_INTERFACE_TYPE=$(head -n 1 < "$mesh_interface_type_file")
    if [[ "$MESH_INTERFACE_TYPE" == 'wlan'* ]]; then
        MESH_INTERFACE_TYPE='wlan'
    fi
    if [[ "$MESH_INTERFACE_TYPE" == 'eth'* ]]; then
        MESH_INTERFACE_TYPE='eth'
    fi
fi

mesh_protocol_init

if [[ "$MESH_INTERFACE_TYPE" == 'eth'* ]]; then
    MESH_INTERFACE_TYPE='eth'
fi

update_wifi_adaptors "${MESH_INTERFACE_TYPE}"

if [ ! "$IFACE" ]; then
    echo $'No wlan adaptor'
    exit 0
fi

if [ -e /etc/default/batctl ]; then
    # shellcheck disable=SC1091
    . /etc/default/batctl
fi

if ! grep -q "$IFACE" /proc/net/dev; then
    echo "Interface \$IFACE was not found"
    stop
    exit 1
fi

case "$1" in
    start|stop|status|monitor)
        $1
        ;;
    restart)
        clear
        echo ''
        echo $'*** Stopping mesh network connection ***'
        echo ''
        stop
        sleep 10
        clear
        echo ''
        echo $'*** Starting mesh network connection ***'
        echo ''
        # shellcheck disable=SC2119
        start
        ;;
    ping)
        batctl ping "$2"
        ;;
    data)
        watch -n1 "batctl s | grep mgmt | grep bytes"
        ;;
    ls|list)
        avahi-browse -atl
        ;;
    *)
        echo "error: invalid parameter $1"
        echo "usage: \$0 {start|stop|restart|status|ping|ls|list}"
        exit 2
        ;;
esac
exit 0