#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# mesh utilities used by the batman and bmx commands
#
# License
# =======
#
# Copyright (C) 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/>.

# File which contains the current protocol in use
MESH_CURRENT_PROTOCOL=/root/.mesh_protocol
MESH_DEFAULT_PROTOCOL=/root/.mesh_protocol_default

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

    if grep -q "bmx6" $MESH_CURRENT_PROTOCOL; then
        bmx stop
    fi

    if grep -q "bmx7" $MESH_CURRENT_PROTOCOL; then
        bmxsec stop
    fi

    if grep -q "batman-adv" $MESH_CURRENT_PROTOCOL; then
        batman stop
    fi

    rm $MESH_CURRENT_PROTOCOL
}

function mesh_protocol_init {
    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
    GIT_SSB_PORT=7718
    NGINX_GIT_SSB_PORT=7719

    # 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
}

function get_ipv4_wlan {
    echo $(ip -o -f inet addr show dev "$IFACE" | 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
        echo 'net.ipv6.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
        sed -i 's|net.ipv6.tcp_challenge_ack_limit.*|net.ipv6.tcp_challenge_ack_limit = 999999999|g' /etc/sysctl.conf
    fi
    sysctl -p -q
}

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 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
    # Don't go straight to cryptpad when navigating to the peer's IP address
    if [ -L /etc/nginx/sites-enabled/cryptpad ]; then
        rm /etc/nginx/sites-enabled/cryptpad
        ln -s /etc/nginx/sites-available/default /etc/nginx/sites-enabled/default
        if [ -d /etc/cryptpad ]; then
            systemctl stop cryptpad
            systemctl disable cryptpad
        fi
        systemctl restart nginx
    fi
    # Don't show the cryptpad icon on the desktop
    if [ -f /home/fbone/Desktop/cryptpad.desktop ]; then
        mv /home/fbone/Desktop/cryptpad.desktop /home/fbone/.cryptpad.desktop
    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 [ ! -f /var/www/html/trifa.apk ]; then
        cp /root/$PROJECT_NAME/image_build/mesh_apps/trifa.apk /var/www/html/trifa.apk
    fi
    if [ ! -d /var/www/html/images ]; then
        mkdir /var/www/html/images
    fi
    if [ ! -f /var/www/html/images/logo.png ]; then
        cp /root/$PROJECT_NAME/img/logo.png /var/www/html/images/logo.png
    fi
    if [ ! -f /var/www/html/images/ssb.png ]; then
        cp /root/$PROJECT_NAME/img/icon_patchwork.png /var/www/html/images/ssb.png
    fi
    if [ ! -f /var/www/html/images/trifa.png ]; then
        cp /root/$PROJECT_NAME/img/trifa.png /var/www/html/images/trifa.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 enable_mesh_firewall {
    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 udp --dport 6240 -j ACCEPT
    iptables -A INPUT -p tcp --dport 6240 -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 tcp --dport $GIT_SSB_PORT -j ACCEPT
    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


    ip6tables -A INPUT -p ipv6-icmp -j ACCEPT
    ip6tables -A OUTPUT -p ipv6-icmp -j ACCEPT
    ip6tables -A INPUT -p tcp --dport $TRACKER_PORT -j ACCEPT
    ip6tables -A INPUT -p udp --dport $TRACKER_PORT -j ACCEPT
    ip6tables -A INPUT -p udp --dport 6240 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport 6240 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport 80 -j ACCEPT
    ip6tables -A INPUT -p udp --dport 80 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport 548 -j ACCEPT
    ip6tables -A INPUT -p udp --dport 548 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport 5353 -j ACCEPT
    ip6tables -A INPUT -p udp --dport 5353 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport 5354 -j ACCEPT
    ip6tables -A INPUT -p udp --dport 5354 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport $ZERONET_PORT -j ACCEPT
    ip6tables -A INPUT -p udp --dport $ZERONET_PORT -j ACCEPT
    ip6tables -A INPUT -p tcp --dport $IPFS_PORT -j ACCEPT
    ip6tables -A INPUT -p tcp --dport $TOX_PORT -j ACCEPT
    ip6tables -A INPUT -p udp --dport $TOX_PORT -j ACCEPT
    ip6tables -A INPUT -p tcp --dport $LIBREVAULT_PORT -j ACCEPT
    ip6tables -A INPUT -p udp --dport $LIBREVAULT_PORT -j ACCEPT
    ip6tables -A INPUT -p tcp --dport $TAHOELAFS_PORT -j ACCEPT
    # SSB/Scuttlebot/Patchwork
    ip6tables -A INPUT -p tcp --dport $GIT_SSB_PORT -j ACCEPT
    ip6tables -A INPUT -p udp --dport 8008 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport 8008 -j ACCEPT
    ip6tables -A INPUT -p udp --dport 8010 -j ACCEPT
    ip6tables -A INPUT -p tcp --dport 8010 -j ACCEPT


    # vpn over the internet
    # Note: the vpn firewall settings are needed in order for Patchwork
    # to discover local peers
    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
}

function disable_mesh_firewall {
    iptables -D INPUT -p tcp --dport $TRACKER_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $TRACKER_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport 6240 -j ACCEPT
    iptables -D INPUT -p tcp --dport 6240 -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 tcp --dport $GIT_SSB_PORT -j ACCEPT
    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


    ip6tables -D INPUT -p tcp --dport $TRACKER_PORT -j ACCEPT
    ip6tables -D INPUT -p udp --dport $TRACKER_PORT -j ACCEPT
    ip6tables -D INPUT -p udp --dport 6240 -j ACCEPT
    ip6tables -D INPUT -p tcp --dport 6240 -j ACCEPT
    ip6tables -D INPUT -p tcp --dport 80 -j ACCEPT
    ip6tables -D INPUT -p udp --dport 80 -j ACCEPT
    ip6tables -D INPUT -p tcp --dport 548 -j ACCEPT
    ip6tables -D INPUT -p udp --dport 548 -j ACCEPT
    ip6tables -D INPUT -p tcp --dport 5353 -j ACCEPT
    ip6tables -D INPUT -p udp --dport 5353 -j ACCEPT
    ip6tables -D INPUT -p tcp --dport 5354 -j ACCEPT
    ip6tables -D INPUT -p udp --dport 5354 -j ACCEPT
    ip6tables -D INPUT -p tcp --dport $ZERONET_PORT -j ACCEPT
    ip6tables -D INPUT -p udp --dport $ZERONET_PORT -j ACCEPT
    ip6tables -D INPUT -p tcp --dport $IPFS_PORT -j ACCEPT
    ip6tables -D INPUT -p udp --dport $IPFS_PORT -j ACCEPT
    ip6tables -D INPUT -p tcp --dport $TOX_PORT -j ACCEPT
    ip6tables -D INPUT -p udp --dport $TOX_PORT -j ACCEPT
    ip6tables -D INPUT -p tcp --dport $LIBREVAULT_PORT -j ACCEPT
    ip6tables -D INPUT -p udp --dport $LIBREVAULT_PORT -j ACCEPT
    ip6tables -D INPUT -p tcp --dport $TAHOELAFS_PORT -j ACCEPT
    # SSB/Scuttlebot/Patchwork
    ip6tables -D INPUT -p tcp --dport $GIT_SSB_PORT -j ACCEPT
    ip6tables -D INPUT -p udp --dport 8008 -j ACCEPT
    ip6tables -D INPUT -p tcp --dport 8008 -j ACCEPT
    ip6tables -D INPUT -p udp --dport 8010 -j ACCEPT
    ip6tables -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
}

function enable_mesh_scuttlebot {
    if [ -f /etc/scuttlebot/.ssb/config ]; then
        ethernet_connected=$(cat /sys/class/net/eth0/carrier)
        if [[ "$ethernet_connected" != "0" ]]; then
            sed -i "s|\"host\": .*|\"host\": \"$(get_ipv4_wlan)\",|g" /etc/scuttlebot/.ssb/config
            systemctl restart scuttlebot
        else
            if [ ! -f /etc/nginx/sites-available/git_ssb ]; then
                systemctl stop scuttlebot
            else
                systemctl restart scuttlebot
            fi
        fi
    fi
    sed -i "s|\"host\":.*|\"host\": \"${HOSTNAME}.local\",|g" /etc/scuttlebot/.ssb/config
    systemctl restart scuttlebot
}

function enable_mesh_tor {
    # if we have an ethernet connection to an internet router then create
    # an onion address for this peer
    if [[ "$ethernet_connected" != "0" ]]; then
        systemctl enable tor
        systemctl start tor
        HIDDEN_SERVICE_PATH=/var/lib/tor/hidden_service_
        if [ ! -f ${HIDDEN_SERVICE_PATH}mesh/hostname ]; then
            echo "HiddenServiceDir ${HIDDEN_SERVICE_PATH}mesh/" >> /etc/tor/torrc
            echo "HiddenServicePort 653 127.0.0.1:653" >> /etc/tor/torrc
            systemctl restart tor
        fi
    else
        systemctl stop tor
        systemctl disable tor
    fi
}

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

        mesh_hotspot_address=$(mesh_hotspot_ip_address)
        if [[ "$mesh_hotspot_address" == *'.'* ]]; then
            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_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

            sed -i "s|#interface=.*|interface=${IFACE_SECONDARY}|g" /etc/dnsmasq.conf
            sed -i "s|interface=.*|interface=${IFACE_SECONDARY}|g" /etc/dnsmasq.conf
            sed -i "s|listen-address=.*|listen-address=127.0.0.1,$mesh_hotspot_address|g" /etc/dnsmasq.conf
            sed -i 's|#listen-address|listen-address|g' /etc/dnsmasq.conf
            systemctl enable dnsmasq
            systemctl restart dnsmasq

            systemctl enable hostapd
            systemctl restart hostapd
            mesh_create_app_downloads_page
        else
            secondary_wifi_available=
            echo $'WARNING: No IP address could be obtained for the hotspot'
        fi
    fi

    if [ ! $secondary_wifi_available ]; then
        systemctl stop hostapd
        systemctl disable hostapd

        # Recreate the cryptpad symlink
        if [ -f /etc/nginx/sites-available/cryptpad ]; then
            if [ -L /etc/nginx/sites-enabled/cryptpad ]; then
                rm /etc/nginx/sites-enabled/default
            fi
            systemctl enable cryptpad
            systemctl start cryptpad

            if [ ! -L /etc/nginx/sites-enabled/cryptpad ]; then
                ln -s /etc/nginx/sites-available/cryptpad /etc/nginx/sites-enabled/cryptpad
                systemctl restart nginx
            fi
        fi
        if [ -f /home/fbone/.cryptpad.desktop ]; then
            mv /home/fbone/.cryptpad.desktop /home/fbone/Desktop/cryptpad.desktop
        fi
    fi
}

# NOTE: deliberately there is no "exit 0"