#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Used to enable or disable batman mesh protocol on wlanX
#
# License
# =======
#
# Copyright (C) 2015-2017 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}"

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

if [[ $1 == "start" ]]; then
    # install avahi
    sed -i "s|#host-name=.*|host-name=$(hostname)|g" /etc/avahi/avahi-daemon.conf
    sed -i "s|host-name=.*|host-name=$(hostname)|g" /etc/avahi/avahi-daemon.conf
    sed -i "s|use-ipv4=.*|use-ipv4=yes|g" /etc/avahi/avahi-daemon.conf
    sed -i "s|use-ipv6=.*|use-ipv6=no|g" /etc/avahi/avahi-daemon.conf
    sed -i "s|#disallow-other-stacks=.*|disallow-other-stacks=yes|g" /etc/avahi/avahi-daemon.conf
    sed -i "s|hosts:.*|hosts:          files mdns4_minimal dns mdns4 mdns|g" /etc/nsswitch.conf
fi

# Mesh definition
WIFI_SSID='mesh'
if [ -f $COMPLETION_FILE ]; then
    if grep -q "WIFI_SSID:" $COMPLETION_FILE; then
        WIFI_SSID=$(cat $COMPLETION_FILE | grep "WIFI_SSID:" | awk -F ':' '{print $2}')
    fi
    sed -i "s|WIFI_SSID:.*|WIFI_SSID:${WIFI_SSID}|g" $COMPLETION_FILE
fi
CELLID='any'

CHANNEL=2
HOTSPOT_CHANNEL=6
if [ -f $COMPLETION_FILE ]; then
    if grep -q "Wifi channel:" $COMPLETION_FILE; then
        CHANNEL=$(cat $COMPLETION_FILE | grep "Wifi channel:" | awk -F ':' '{print $2}')
    fi
    sed -i "s|Wifi channel:.*|Wifi channel:${CHANNEL}|g" $COMPLETION_FILE
fi

ZERONET_PORT=15441
IPFS_PORT=4001
TOX_PORT=33445
TRACKER_PORT=6969
LIBREVAULT_PORT=42345
TAHOELAFS_PORT=50213

# Ethernet bridge definition (bridged to bat0)
BRIDGE=br-mesh
BRIDGE_HOTSPOT=br-hotspot
IFACE=
IFACE_SECONDARY=
EIFACE=eth0
WLAN_ADAPTORS=$(count_wlan)

if [ $WLAN_ADAPTORS -eq 0 ]; then
    echo $'No wlan adaptors found'
    exit 0
fi

update_wifi_adaptors

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

if [ -e /etc/default/batctl ]; then
    . /etc/default/batctl
fi

function get_ipv6_bat0 {
    echo $(ip -o -f inet6 addr show dev "bat0" | awk '{print $4}' | awk 'END {print}' | awk -F '/' '{print $1}')
}

function mesh_hotspot_ip_address {
    echo $(ip -o -f inet addr show dev "$BRIDGE" | awk '{print $4}' | awk 'END {print}' | awk -F '/' '{print $1}')
}

function global_rate_limit {
    if ! grep -q "tcp_challenge_ack_limit" /etc/sysctl.conf; then
        echo 'net.ipv4.tcp_challenge_ack_limit = 999999999' >> /etc/sysctl.conf
    else
        sed -i 's|net.ipv4.tcp_challenge_ack_limit.*|net.ipv4.tcp_challenge_ack_limit = 999999999|g' /etc/sysctl.conf
    fi
    sysctl -p -q
}

function status {
    batctl o
}

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

    avahi-autoipd -k $BRIDGE
    avahi-autoipd -k $IFACE
    ifconfig bat0 down -promisc

    batctl if del $IFACE
    ifconfig $IFACE mtu 1500
    ifconfig $IFACE down
    iwconfig $IFACE mode managed

    if [ $IFACE_SECONDARY ]; then
        systemctl stop hostapd
        systemctl disable hostapd
        batctl if del $IFACE_SECONDARY
        ifconfig $IFACE_SECONDARY mtu 1500
        ifconfig $IFACE_SECONDARY down
        iwconfig $IFACE_SECONDARY mode managed
    fi

    rmmod batman-adv

    iptables -D INPUT -p tcp --dport $TRACKER_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $TRACKER_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport 80 -j ACCEPT
    iptables -D INPUT -p udp --dport 80 -j ACCEPT
    iptables -D INPUT -p tcp --dport 548 -j ACCEPT
    iptables -D INPUT -p udp --dport 548 -j ACCEPT
    iptables -D INPUT -p tcp --dport 5353 -j ACCEPT
    iptables -D INPUT -p udp --dport 5353 -j ACCEPT
    iptables -D INPUT -p tcp --dport 5354 -j ACCEPT
    iptables -D INPUT -p udp --dport 5354 -j ACCEPT
    iptables -D INPUT -p tcp --dport $ZERONET_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $ZERONET_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $IPFS_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $IPFS_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $TOX_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $TOX_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $LIBREVAULT_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $LIBREVAULT_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $TAHOELAFS_PORT -j ACCEPT
    # SSB/Scuttlebot/Patchwork
    iptables -D INPUT -p udp --dport 8008 -j ACCEPT
    iptables -D INPUT -p tcp --dport 8008 -j ACCEPT
    iptables -D INPUT -p udp --dport 8010 -j ACCEPT
    iptables -D INPUT -p tcp --dport 8010 -j ACCEPT
    # vpn over the internet
    iptables -D INPUT -p tcp --dport 653 -j ACCEPT
    iptables -D INPUT -p udp --dport 653 -j ACCEPT
    iptables -D INPUT -i ${EIFACE} -m state --state NEW -p tcp --dport 1194 -j ACCEPT
    iptables -D INPUT -i tun+ -j ACCEPT
    iptables -D FORWARD -i tun+ -j ACCEPT
    iptables -D FORWARD -i tun+ -o ${EIFACE} -m state --state RELATED,ESTABLISHED -j ACCEPT
    iptables -D FORWARD -i ${EIFACE} -o tun+ -m state --state RELATED,ESTABLISHED -j ACCEPT
    iptables -t nat -D POSTROUTING -s 10.8.0.0/24 -o ${EIFACE} -j MASQUERADE
    iptables -D OUTPUT -o tun+ -j ACCEPT

    echo 0 > /proc/sys/net/ipv4/ip_forward
    sed -i 's|net.ipv4.ip_forward=.*|net.ipv4.ip_forward=0|g' /etc/sysctl.conf

    systemctl restart network-manager
}

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 assign_peer_address {
    for i in {1..6}; do
        number=$RANDOM
        let "number %= 255"
        octet=$(echo "obase=16;$number" | bc)
        if [ ${#octet} -lt 2 ]; then
            octet="0${octet}"
        fi
        if [ $i -gt 1 ]; then
            echo -n ":"
        fi
        echo -n "${octet}"
    done
}

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"
    iwconfig $ifname enc off
    iwconfig $ifname mode $ifmode essid $ifssid channel $ifchannel

    batctl if add $ifname
    ifconfig $ifname up
}

function mesh_create_app_downloads_page {
    if [ ! -d /root/$PROJECT_NAME/image_build/mesh_apps ]; then
        return
    fi
    if [ ! -d /var/www/html ]; then
        return
    fi
    cp /root/$PROJECT_NAME/website/EN/meshindex.html /var/www/html/index.html
    if [ ! -f /var/www/html/ssb.apk ]; then
        cp /root/$PROJECT_NAME/image_build/mesh_apps/ssb.apk /var/www/html/ssb.apk
    fi
    if [ ! -d /var/www/html/images ]; then
        mkdir /var/www/html/images
    fi
    if [ ! -f /var/www/html/images/logo.png ]; then
        cp /root/$PROJECT_NAME/img/logo.png /var/www/html/images/logo.png
    fi
    if [ ! -f /var/www/html/images/ssb.png ]; then
        cp /root/$PROJECT_NAME/img/icon_patchwork.png /var/www/html/images/ssb.png
    fi
    if [ ! -f /var/www/html/freedombone.css ]; then
        cp /root/$PROJECT_NAME/website/freedombone.css /var/www/html/freedombone.css
    fi
    chown -R www-data:www-data /var/www/html/*
}

function start {
    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"

    systemctl stop network-manager
    sleep 5

    # 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 [ $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

    modprobe batman-adv

    add_wifi_interface $IFACE $WIFI_SSID ad-hoc $CHANNEL
    avahi-autoipd --force-bind --daemonize --wait $IFACE

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

    ifconfig bat0 up promisc

    brctl addbr $BRIDGE
    brctl addif $BRIDGE bat0
    ifconfig bat0 0.0.0.0
    if [ "$EIFACE" ] ; 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 ethernet bridge'
        else
            echo $"$EIFACE is not connected"
        fi
    fi
    ifconfig $BRIDGE up
    dhclient $BRIDGE

    if [ $secondary_wifi_available ]; then
        sed -i 's|#DAEMON_CONF=.*|DAEMON_CONF="/etc/hostapd/hostapd.conf"|g' /etc/default/hostapd

        echo "interface=${IFACE_SECONDARY}" > /etc/hostapd/hostapd.conf
        echo "bridge=${BRIDGE}" >> /etc/hostapd/hostapd.conf
        echo 'driver=nl80211' >> /etc/hostapd/hostapd.conf
        echo "country_code=UK" >> /etc/hostapd/hostapd.conf
        echo "ssid=${WIFI_SSID}-$(mesh_hotspot_ip_address)" >> /etc/hostapd/hostapd.conf
        echo 'hw_mode=g' >> /etc/hostapd/hostapd.conf
        echo "channel=${HOTSPOT_CHANNEL}" >> /etc/hostapd/hostapd.conf
        echo 'wpa=2' >> /etc/hostapd/hostapd.conf
        echo "wpa_passphrase=$HOTSPOT_PASSPHRASE" >> /etc/hostapd/hostapd.conf
        echo 'wpa_key_mgmt=WPA-PSK' >> /etc/hostapd/hostapd.conf
        echo 'wpa_pairwise=TKIP' >> /etc/hostapd/hostapd.conf
        echo 'rsn_pairwise=CCMP' >> /etc/hostapd/hostapd.conf
        echo 'auth_algs=1' >> /etc/hostapd/hostapd.conf
        echo 'macaddr_acl=0' >> /etc/hostapd/hostapd.conf

        systemctl enable hostapd
        systemctl restart hostapd
        mesh_create_app_downloads_page
    fi

    iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
    iptables -A OUTPUT -p icmp --icmp-type echo-reply -j ACCEPT
    iptables -A INPUT -p tcp --dport $TRACKER_PORT -j ACCEPT
    iptables -A INPUT -p udp --dport $TRACKER_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport 80 -j ACCEPT
    iptables -A INPUT -p udp --dport 80 -j ACCEPT
    iptables -A INPUT -p tcp --dport 548 -j ACCEPT
    iptables -A INPUT -p udp --dport 548 -j ACCEPT
    iptables -A INPUT -p tcp --dport 5353 -j ACCEPT
    iptables -A INPUT -p udp --dport 5353 -j ACCEPT
    iptables -A INPUT -p tcp --dport 5354 -j ACCEPT
    iptables -A INPUT -p udp --dport 5354 -j ACCEPT
    iptables -A INPUT -p tcp --dport $ZERONET_PORT -j ACCEPT
    iptables -A INPUT -p udp --dport $ZERONET_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $IPFS_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $TOX_PORT -j ACCEPT
    iptables -A INPUT -p udp --dport $TOX_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $LIBREVAULT_PORT -j ACCEPT
    iptables -A INPUT -p udp --dport $LIBREVAULT_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $TAHOELAFS_PORT -j ACCEPT
    # SSB/Scuttlebot/Patchwork
    iptables -A INPUT -p udp --dport 8008 -j ACCEPT
    iptables -A INPUT -p tcp --dport 8008 -j ACCEPT
    iptables -A INPUT -p udp --dport 8010 -j ACCEPT
    iptables -A INPUT -p tcp --dport 8010 -j ACCEPT
    # vpn over the internet
    iptables -A INPUT -p tcp --dport 653 -j ACCEPT
    iptables -A INPUT -p udp --dport 653 -j ACCEPT
    iptables -A INPUT -i ${EIFACE} -m state --state NEW -p tcp --dport 1194 -j ACCEPT
    iptables -A INPUT -i tun+ -j ACCEPT
    iptables -A FORWARD -i tun+ -j ACCEPT
    iptables -A FORWARD -i tun+ -o ${EIFACE} -m state --state RELATED,ESTABLISHED -j ACCEPT
    iptables -A FORWARD -i ${EIFACE} -o tun+ -m state --state RELATED,ESTABLISHED -j ACCEPT
    iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o ${EIFACE} -j MASQUERADE
    iptables -A OUTPUT -o tun+ -j ACCEPT

    echo 1 > /proc/sys/net/ipv4/ip_forward
    sed -i 's|# net.ipv4.ip_forward|net.ipv4.ip_forward|g' /etc/sysctl.conf
    sed -i 's|#net.ipv4.ip_forward|net.ipv4.ip_forward|g' /etc/sysctl.conf
    sed -i 's|net.ipv4.ip_forward.*|net.ipv4.ip_forward=1|g' /etc/sysctl.conf

    systemctl restart avahi-daemon

    if [ -f /etc/scuttlebot/.ssb/config ]; then
        ipv6addr=$(get_ipv6_bat0)
        sed -i "s|\"host\": .*|\"host\": \"${ipv6addr}\",|g" /etc/scuttlebot/.ssb/config
        systemctl restart scuttlebot
    fi

    verify
}

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

    stop

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

    systemctl stop network-manager
    sleep 5

    global_rate_limit

    # 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
    start
}

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)
        stop
        sleep 10
        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