#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Onion functions
#
# License
# =======
#
# Copyright (C) 2014-2016 Bob Mottram <bob@robotics.uk.to>
#
# 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/>.

function wait_for_onion_service {
    onion_service_name="$1"

    sleep_ctr=0
    while [ ! -f /var/lib/tor/hidden_service_${onion_service_name}/hostname ]; do
        sleep 1
        sleep_ctr=$((sleep_ctr + 1))
        if [ $sleep_ctr -gt 10 ]; then
            break
        fi
    done

    if [ ! -f /var/lib/tor/hidden_service_${onion_service_name}/hostname ]; then
        # reload and try a second time
        systemctl reload tor
        sleep_ctr=0
        while [ ! -f /var/lib/tor/hidden_service_${onion_service_name}/hostname ]; do
            sleep 1
            sleep_ctr=$((sleep_ctr + 1))
            if [ $sleep_ctr -gt 10 ]; then
                break
            fi
        done
    fi
}

function remove_onion_service {
    onion_service_name="$1"
    onion_service_port_to=$2
    sed -i "/hidden_service_${onion_service_name}/d" /etc/tor/torrc
    sed -i "/127.0.0.1:${onion_service_port_to}/d" /etc/tor/torrc
    if [ $3 ]; then
        sed -i "/127.0.0.1:${3}/d" /etc/tor/torrc
        if [ $4 ]; then
            sed -i "/127.0.0.1:${4}/d" /etc/tor/torrc
            if [ $5 ]; then
                sed -i "/127.0.0.1:${5}/d" /etc/tor/torrc
            fi
        fi
    fi
    if [ -d /var/lib/tor/hidden_service_${onion_service_name} ]; then
        shred -zu /var/lib/tor/hidden_service_${onion_service_name}/*
        rm -rf /var/lib/tor/hidden_service_${onion_service_name}
    fi
    systemctl reload tor
}

function add_onion_service {
    onion_service_name="$1"
    onion_service_port_from=$2
    onion_service_port_to=$3

    if [ -f /var/lib/tor/hidden_service_${onion_service_name}/hostname ]; then
        echo $(cat /var/lib/tor/hidden_service_${onion_service_name}/hostname)
        return
    fi

    if [ ! -d /var/lib/tor ]; then
        echo $"No Tor installation found. ${onion_service_name} onion site cannot be configured."
        exit 877367
    fi
    if ! grep -q "hidden_service_${onion_service_name}" /etc/tor/torrc; then
        echo "HiddenServiceDir /var/lib/tor/hidden_service_${onion_service_name}/" >> /etc/tor/torrc
        echo "HiddenServicePort ${onion_service_port_from} 127.0.0.1:${onion_service_port_to}" >> /etc/tor/torrc
    fi

    systemctl reload tor

    function_check wait_for_onion_service
    wait_for_onion_service ${onion_service_name}

    if [ ! -f /var/lib/tor/hidden_service_${onion_service_name}/hostname ]; then
        echo $"${onion_service_name} onion site hostname not found"
        exit 76362
    fi

    onion_address=$(cat /var/lib/tor/hidden_service_${onion_service_name}/hostname)

    # Record the domain in the completion file
    if [ -f $COMPLETION_FILE ]; then
        if ! grep "${onion_service_name} onion domain" $COMPLETION_FILE; then
            echo "${onion_service_name} onion domain:${onion_address}" >> $COMPLETION_FILE
        else
            sed -i "s|${onion_service_name} onion domain.*|${onion_service_name} onion domain:${onion_address}|g" $COMPLETION_FILE
        fi
    fi

    echo $onion_address
}

function set_default_onion_domains {
    # If sites are only visible via Tor then for installation
    # purposes assign them some default domain names
    if [[ $ONION_ONLY == "no" ]]; then
        return
    fi

    MICROBLOG_DOMAIN_NAME='microblog.local'
    FULLBLOG_DOMAIN_NAME='blog.local'
    WIKI_DOMAIN_NAME='wiki.local'
    DEFAULT_DOMAIN_NAME="${PROJECT_NAME}.local"
    GIT_DOMAIN_NAME='git.local'
    MEDIAGOBLIN_DOMAIN_NAME='media.local'
}

function create_avahi_onion_domains {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if [ ! -d /etc/avahi/services ]; then
        return
    fi
    if [ $MICROBLOG_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service microblog http tcp $MICROBLOG_ONION_PORT
    fi
    if [ $FULLBLOG_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service blog http tcp $BLOG_ONION_PORT
    fi
    if [ $GIT_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service git http tcp $GIT_ONION_PORT
    fi
    if [ $WIKI_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service wiki http tcp $WIKI_ONION_PORT
    fi
}

function allow_ssh_to_onion_address {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if [ ! -d /home/$MY_USERNAME/.ssh ]; then
        mkdir /home/$MY_USERNAME/.ssh
    fi
    if [ ! -d /etc/tor ]; then
        echo $'Tor not found when updating ssh'
        exit 528257
    fi
    if ! grep -q "onion" /home/$MY_USERNAME/.ssh/config; then
        echo 'Host *.onion' >> /home/$MY_USERNAME/.ssh/config
        echo 'ProxyCommand connect -R remote -5 -S 127.0.0.1:9050 %h %p' >> /home/$MY_USERNAME/.ssh/config
    fi
}

function enable_ssh_via_onion {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if grep -Fxq "enable_ssh_via_onion" $COMPLETION_FILE; then
        return
    fi
    apt-get -y install tor connect-proxy
    if ! grep -q 'Host *.onion' /home/$MY_USERNAME/.ssh/config; then
        if [ ! -d /home/$MY_USERNAME/.ssh ]; then
            mkdir /home/$MY_USERNAME/.ssh
        fi
        echo 'Host *.onion' >> /home/$MY_USERNAME/.ssh/config
        echo 'ProxyCommand connect -R remote -5 -S 127.0.0.1:9050 %h %p' >> /home/$MY_USERNAME/.ssh/config
        chown $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME/.ssh
        chown $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME/.ssh/config
    fi
    if ! grep -q 'Host *.onion' /root/.ssh/config; then
        if [ ! -d /root/.ssh ]; then
            mkdir /root/.ssh
        fi
        echo 'Host *.onion' >> /root/.ssh/config
        echo 'ProxyCommand connect -R remote -5 -S 127.0.0.1:9050 %h %p' >> /root/.ssh/config
    fi
    echo 'enable_ssh_via_onion' >> $COMPLETION_FILE
}

function configure_ssh_onion {
    if grep -Fxq "configure_ssh_onion" $COMPLETION_FILE; then
        return
    fi
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi

    SSH_ONION_HOSTNAME=$(add_onion_service ssh ${SSH_PORT} ${SSH_PORT})

    if ! grep -q "ssh onion domain" $COMPLETION_FILE; then
        echo "ssh onion domain:${SSH_ONION_HOSTNAME}" >> $COMPLETION_FILE
    else
        sed -i "s|ssh onion domain.*|ssh onion domain:${SSH_ONION_HOSTNAME}|g" $COMPLETION_FILE
    fi

    echo 'configure_ssh_onion' >> $COMPLETION_FILE
}

function install_tor {
    if [[ $SYSTEM_TYPE == "mesh*" ]]; then
        return
    fi
    if grep -Fxq "install_tor" $COMPLETION_FILE; then
        return
    fi
    apt-get -y install tor
    if [ ! -f /etc/tor/torrc ]; then
        echo 'Tor failed to install'
        exit 38259
    fi
    echo 'install_tor' >> $COMPLETION_FILE
}

function resolve_dns_via_tor {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if grep -Fxq "resolve_dns_via_tor" $COMPLETION_FILE; then
        return
    fi
    if [ ! -f /etc/tor/torrc ]; then
        echo $'tor was not installed'
        exit 52952
    fi

    # resolve DNS via tor
    if ! grep 'DNSPort 53' /etc/tor/torrc; then
        echo 'DNSPort 53' >> /etc/tor/torrc
        echo 'AutomapHostsOnResolve 1' >> /etc/tor/torrc
        echo 'AutomapHostsSuffixes .exit,.onion' >> /etc/tor/torrc
        systemctl reload tor
    fi

    # don't change resolv.conf
    sed -i 's|, domain-name-servers||g' /etc/dhcp/dhclient.conf

    # point resolv.conf to tor
    echo 'nameserver 127.0.0.1:53' > /etc/resolv.conf

    # prevent resolv.conf from changing
    chattr +i /etc/resolv.conf

    echo 'resolve_dns_via_tor' >> $COMPLETION_FILE
}

# see https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy
# Local Redirection and Anonymizing Middlebox
function route_outgoing_traffic_through_tor {
    if grep -Fxq "route_outgoing_traffic_through_tor" $COMPLETION_FILE; then
        return
    fi
    if [[ $ROUTE_THROUGH_TOR != "yes" ]]; then
        return
    fi
    apt-get -y install tor tor-arm

    ### set variables
    # Destinations you don't want routed through Tor
    _non_tor="192.168.1.0/24 192.168.0.0/24"

    # The user that Tor runs as
    _tor_uid="debian-tor"

    # Tor's TransPort
    _trans_port="9040"

    # Your internal interface
    _int_if="eth0"

    ### Set iptables *nat
    iptables -t nat -A OUTPUT -o lo -j RETURN
    iptables -t nat -A OUTPUT -m owner --uid-owner $_tor_uid -j RETURN
    iptables -t nat -A OUTPUT -p udp --dport 53 -j REDIRECT --to-ports 53

    # Allow clearnet access for hosts in $_non_tor
    for _clearnet in $_non_tor; do
        iptables -t nat -A OUTPUT -d $_clearnet -j RETURN
        iptables -t nat -A PREROUTING -i $_int_if -d $_clearnet -j RETURN
    done

    # Redirect all other pre-routing and output to Tor
    iptables -t nat -A OUTPUT -p tcp --syn -j REDIRECT --to-ports $_trans_port
    iptables -t nat -A PREROUTING -i $_int_if -p udp --dport 53 -j REDIRECT --to-ports 53
    iptables -t nat -A PREROUTING -i $_int_if -p tcp --syn -j REDIRECT --to-ports $_trans_port

    ### set iptables *filter
    iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

    # Allow clearnet access for hosts in $_non_tor
    for _clearnet in $_non_tor 127.0.0.0/8; do
        iptables -A OUTPUT -d $_clearnet -j ACCEPT
    done

    # Allow only Tor output
    iptables -A OUTPUT -m owner --uid-owner $_tor_uid -j ACCEPT
    iptables -A OUTPUT -j REJECT

    function_check save_firewall_settings
    save_firewall_settings

    if ! grep -q "fs.file-max" /etc/sysctl.conf; then
        echo "fs.file-max=100000" >> /etc/sysctl.conf
        /sbin/sysctl -p -q
    fi

    echo 'domain localdomain' > /etc/resolv.conf
    echo 'search localdomain' >> /etc/resolv.conf
    echo 'nameserver 127.0.0.1' >> /etc/resolv.conf

    if ! grep -q "VirtualAddrNetworkIPv4" /etc/tor/torrc; then
        echo 'VirtualAddrNetworkIPv4 10.192.0.0/10' >> /etc/tor/torrc
    fi

    if ! grep -q "AutomapHostsOnResolve" /etc/tor/torrc; then
        echo 'AutomapHostsOnResolve 1' >> /etc/tor/torrc
    fi

    if ! grep -q "TransPort" /etc/tor/torrc; then
        echo 'TransPort 9040' >> /etc/tor/torrc
    fi

    if ! grep -q "TransListenAddress 127.0.0.1" /etc/tor/torrc; then
        echo 'TransListenAddress 127.0.0.1' >> /etc/tor/torrc
    fi

    if ! grep -q "TransListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" /etc/tor/torrc; then
        echo "TransListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" >> /etc/tor/torrc
    fi

    if ! grep -q "DNSPort" /etc/tor/torrc; then
        echo 'DNSPort 53' >> /etc/tor/torrc
    fi

    if ! grep -q "DNSListenAddress 127.0.0.1" /etc/tor/torrc; then
        echo 'DNSListenAddress 127.0.0.1' >> /etc/tor/torrc
    fi

    if ! grep -q "DNSListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" /etc/tor/torrc; then
        echo "DNSListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" >> /etc/tor/torrc
    fi

    echo 'route_outgoing_traffic_through_tor' >> $COMPLETION_FILE
}

# NOTE: deliberately no exit 0
