#!/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_${onion_service_name}/hostname ]; then
		# restart and try a second time
		systemctl restart tor
		sleep_ctr=0
		while [ ! -f /var/lib/tor/hidden_service_${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
	systemctl restart 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 restart 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
	echo $(cat /var/lib/tor/hidden_service_${onion_service_name}/hostname)
}

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

	if [ ${#MICROBLOG_DOMAIN_NAME} -gt 1 ]; then
		MICROBLOG_DOMAIN_NAME='microblog.local'
	fi
	if [ ${#FULLBLOG_DOMAIN_NAME} -gt 1 ]; then
		FULLBLOG_DOMAIN_NAME='blog.local'
	fi
	if [ ${#WIKI_DOMAIN_NAME} -gt 1 ]; then
		WIKI_DOMAIN_NAME='wiki.local'
	fi
	if [ ${#DEFAULT_DOMAIN_NAME} -gt 1 ]; then
		DEFAULT_DOMAIN_NAME="${PROJECT_NAME}.local"
	fi
	if [ ${#GIT_DOMAIN_NAME} -gt 1 ]; then
		GIT_DOMAIN_NAME='git.local'
	fi
	if [ ${#MEDIAGOBLIN_DOMAIN_NAME} -gt 1 ]; then
		MEDIAGOBLIN_DOMAIN_NAME='media.local'
	fi
}

function create_avahi_onion_domains {
	if [[ $SYSTEM_TYPE == "$VARIANT_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 [[ $SYSTEM_TYPE == "$VARIANT_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 [[ $SYSTEM_TYPE == "$VARIANT_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 [[ $SYSTEM_TYPE == "$VARIANT_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 [[ $SYSTEM_TYPE == "$VARIANT_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 [[ $SYSTEM_TYPE == "$VARIANT_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 restart 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
	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