#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# SIP 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/>.

VARIANTS='full chat'

SIP_SERVER_PASSWORD=
SIP_PORT=5060
SIP_TLS_PORT=5061
VOIP_TURN_PORT=3478
VOIP_TURN_TLS_PORT=5349
VOIP_TURN_NONCE=

function reconfigure_sip {
    echo -n ''
}

function upgrade_sip {
    # remove the original sipwitch daemon if it exists
    if [ -f /etc/init.d/sipwitch ]; then
	rm -f /etc/init.d/sipwitch
    fi
}

function backup_local_sip {
    if [ -f /etc/sipwitch.conf ]; then
	echo $"Backing up SIP settings"
	temp_backup_dir=/root/tempsipbackup
	if [ ! -d $temp_backup_dir ]; then
	    mkdir -p $temp_backup_dir
	fi
	cp -f /etc/sipwitch.conf $temp_backup_dir
	backup_directory_to_usb $temp_backup_dir sip
	echo $"SIP settings backup complete"
    fi
}

function restore_local_sip {
    if [ -d $USB_MOUNT/backup/sip ]; then
	echo $"Restoring SIP settings"
	temp_restore_dir=/root/tempsip
	function_check restore_directory_from_usb
	restore_directory_from_usb $temp_restore_dir sip
	cp -f $temp_restore_dir/home/$ADMIN_USERNAME/tempbackup/sipwitch.conf /etc/sipwitch.conf
	if [ ! "$?" = "0" ]; then
	    rm -rf $temp_restore_dir
	    function_check set_user_permissions
	    set_user_permissions
	    backup_unmount_drive
	    exit 3679
	fi
	rm -rf $temp_restore_dir
	service sipwitch restart
	echo $"Restore of SIP settings complete"
    fi
}

function backup_remote_sip {
    if [ -f /etc/sipwitch.conf ]; then
	echo $"Backing up SIP settings"
	temp_backup_dir=/root/tempsipbackup
	if [ ! -d $temp_backup_dir ]; then
	    mkdir -p $temp_backup_dir
	fi
	cp -f /etc/sipwitch.conf $temp_backup_dir
	backup_directory_to_friend $temp_backup_dir sip
	echo $"Backup SIP settings complete"
    fi
}

function restore_remote_sip {
    echo -n ''
}

function remove_sip {
    if ! grep -Fxq "install_sip" $COMPLETION_FILE; then
	return
    fi
    iptables -D INPUT -p udp --dport $VOIP_TURN_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $VOIP_TURN_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $VOIP_TURN_TLS_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $SIP_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $SIP_PORT -j ACCEPT
    iptables -D INPUT -p udp --dport $SIP_TLS_PORT -j ACCEPT
    iptables -D INPUT -p tcp --dport $SIP_TLS_PORT -j ACCEPT
    function_check save_firewall_settings
    save_firewall_settings

    function_check remove_onion_service
    remove_onion_service sip ${SIP_PORT}

    apt-get -y remove --purge sipwitch
    apt-get -y remove --purge turnserver
    if [ -f /etc/sipwitch.conf ]; then
	rm /etc/sipwitch.conf
    fi
    if [ -d /etc/turnserver ]; then
	rm -rf /etc/turnserver
    fi
    sed -i '/install_sip/d' $COMPLETION_FILE
    sed -i '/configure_firewall_for_voip_turn/d' $COMPLETION_FILE
    sed -i '/configure_firewall_for_sip4/d' $COMPLETION_FILE
}

function configure_firewall_for_voip_turn {
    if grep -Fxq "configure_firewall_for_voip_turn" $COMPLETION_FILE; then
	return
    fi
    if [[ $ONION_ONLY != "no" ]]; then
	return
    fi
    iptables -A INPUT -p udp --dport $VOIP_TURN_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $VOIP_TURN_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $VOIP_TURN_TLS_PORT -j ACCEPT
    function_check save_firewall_settings
    save_firewall_settings

    OPEN_PORTS+=("TURN     $VOIP_TURN_PORT")
    OPEN_PORTS+=("TURN TLS $VOIP_TURN_TLS_PORT")
    echo 'configure_firewall_for_voip_turn' >> $COMPLETION_FILE
}


function configure_firewall_for_sip4 {
    if grep -Fxq "configure_firewall_for_sip4" $COMPLETION_FILE; then
	return
    fi
    if [[ $ONION_ONLY != "no" ]]; then
	return
    fi
    iptables -A INPUT -p udp --dport $SIP_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $SIP_PORT -j ACCEPT
    iptables -A INPUT -p udp --dport $SIP_TLS_PORT -j ACCEPT
    iptables -A INPUT -p tcp --dport $SIP_TLS_PORT -j ACCEPT
    function_check save_firewall_settings
    save_firewall_settings

    OPEN_PORTS+=("SIP      $SIP_PORT")
    OPEN_PORTS+=("SIP TLS  $SIP_TLS_PORT")
    echo 'configure_firewall_for_sip4' >> $COMPLETION_FILE
}

function get_sip_server_password {
    if [ -f /home/$MY_USERNAME/README ]; then
	if grep -q "SIP server password" /home/$MY_USERNAME/README; then
	    if [ ! $SIP_SERVER_PASSWORD ]; then
		SIP_SERVER_PASSWORD=$(cat /home/$MY_USERNAME/README | grep "SIP server password" | awk -F ':' '{print $2}' | sed 's/^ *//')
	    fi
	fi
    fi
}

function update_sipwitch_daemon {
    if [ ! -f /etc/init.d/sipwitch ]; then
	return
    fi
    service sipwitch stop

    # remove the original sipwitch daemon if it exists
    if [ -f /etc/init.d/sipwitch ]; then
	rm -f /etc/init.d/sipwitch
    fi

    # daemon
    echo '[Unit]' > /etc/systemd/system/sipwitch.service
    echo 'Description=GNU SIP Witch, a SIP telephony service daemon.' >> /etc/systemd/system/sipwitch.service
    echo 'After=network.target' >> /etc/systemd/system/sipwitch.service
    echo '' >> /etc/systemd/system/sipwitch.service
    echo '[Service]' >> /etc/systemd/system/sipwitch.service
    echo 'Type=simple' >> /etc/systemd/system/sipwitch.service
    echo 'Group=sipwitch' >> /etc/systemd/system/sipwitch.service
    echo 'PIDFile=/var/run/sipwitch/pidfile' >> /etc/systemd/system/sipwitch.service
    echo 'EnvironmentFile=-/etc/conf.d/sipwitch' >> /etc/systemd/system/sipwitch.service
    echo 'EnvironmentFile=-/etc/sipwitch.conf' >> /etc/systemd/system/sipwitch.service
    echo 'EnvironmentFile=-/etc/default/sipwitch' >> /etc/systemd/system/sipwitch.service
    echo 'ExecStartPre=-/bin/rm -f /var/run/sipwitch/control' >> /etc/systemd/system/sipwitch.service
    echo "ExecStart=/usr/sbin/sipw -f \$OPTIONS -P$SIP_PORT" >> /etc/systemd/system/sipwitch.service
    echo 'Restart=always' >> /etc/systemd/system/sipwitch.service
    echo 'NotifyAccess=main' >> /etc/systemd/system/sipwitch.service
    echo '' >> /etc/systemd/system/sipwitch.service
    echo '[Install]' >> /etc/systemd/system/sipwitch.service
    echo 'WantedBy=multi-user.target' >> /etc/systemd/system/sipwitch.service

    systemctl enable sipwitch
    systemctl daemon-reload
    systemctl start sipwitch
}

function install_sip_main {
    if grep -Fxq "install_sip_main" $COMPLETION_FILE; then
	return
    fi

    apt-get -y install sipwitch

    function_check get_sip_server_password
    get_sip_server_password
    if [ ! $SIP_SERVER_PASSWORD ]; then
	if [ -f $IMAGE_PASSWORD_FILE ]; then
	    SIP_SERVER_PASSWORD="$(printf `cat $IMAGE_PASSWORD_FILE`)"
	else
	    SIP_SERVER_PASSWORD="$(create_password ${MINIMUM_PASSWORD_LENGTH})"
	fi
    fi

    echo '<?xml version="1.0"?>' > /etc/sipwitch.conf
    echo '<sipwitch>' >> /etc/sipwitch.conf
    echo '<provision>' >> /etc/sipwitch.conf

    echo "<user id=\"$MY_USERNAME\">" >> /etc/sipwitch.conf
    echo '<extension>201</extension>' >> /etc/sipwitch.conf
    echo "<secret>$SIP_SERVER_PASSWORD</secret>" >> /etc/sipwitch.conf
    echo "<display>$MY_USERNAME 201</display>" >> /etc/sipwitch.conf
    echo '</user>' >> /etc/sipwitch.conf

    echo '</provision>' >> /etc/sipwitch.conf
    echo '<access>' >> /etc/sipwitch.conf
    echo '</access>' >> /etc/sipwitch.conf
    echo '<stack>' >> /etc/sipwitch.conf
    echo "  <localnames>$DEFAULT_DOMAIN_NAME</localnames>" >> /etc/sipwitch.conf
    echo '  <mapped>200</mapped>' >> /etc/sipwitch.conf
    echo '  <threading>2</threading>' >> /etc/sipwitch.conf
    echo '  <interface>*</interface>' >> /etc/sipwitch.conf
    echo '  <dumping>false</dumping>' >> /etc/sipwitch.conf
    echo '  <system>system</system>' >> /etc/sipwitch.conf
    echo '  <anon>anonymous</anon>' >> /etc/sipwitch.conf
    echo '</stack>' >> /etc/sipwitch.conf
    echo '<timers>' >> /etc/sipwitch.conf
    echo '  <!-- ring every 4 seconds -->' >> /etc/sipwitch.conf
    echo '  <ring>4</ring>' >> /etc/sipwitch.conf
    echo '  <!-- call forward no answer after x rings -->' >> /etc/sipwitch.conf
    echo '  <cfna>4</cfna>' >> /etc/sipwitch.conf
    echo '  <!-- call reset to clear cid in stack, 6 seconds -->' >> /etc/sipwitch.conf
    echo '  <reset>6</reset>' >> /etc/sipwitch.conf
    echo '</timers>' >> /etc/sipwitch.conf
    echo '<!-- we have 2xx numbers plus space for external users -->' >> /etc/sipwitch.conf
    echo '<registry>' >> /etc/sipwitch.conf
    echo '  <prefix>200</prefix>' >> /etc/sipwitch.conf
    echo '  <range>100</range>' >> /etc/sipwitch.conf
    echo '  <keysize>77</keysize>' >> /etc/sipwitch.conf
    echo '  <mapped>200</mapped>' >> /etc/sipwitch.conf
    echo '  <!-- <realm>GNU Telephony</realm> -->' >> /etc/sipwitch.conf
    echo '</registry>' >> /etc/sipwitch.conf
    echo '<routing>' >> /etc/sipwitch.conf
    echo '</routing>' >> /etc/sipwitch.conf
    echo '</sipwitch>' >> /etc/sipwitch.conf

    sed -i 's|#PLUGINS=|PLUGINS=|g' /etc/default/sipwitch
    sed -i 's|PLUGINS=.*|PLUGINS="zeroconf subscriber forward"|g' /etc/default/sipwitch
    groupadd sipwitch
    usermod -aG sipwitch $MY_USERNAME

    SIP_ONION_HOSTNAME=$(add_onion_service sip ${SIP_PORT} ${SIP_PORT})
    if ! grep -q $"SIP onion domain" $COMPLETION_FILE; then
	echo "SIP onion domain:$SIP_ONION_HOSTNAME" >> $COMPLETION_FILE
    fi

    if ! grep -q $"SIP Server" /home/$MY_USERNAME/README; then
	echo '' >> /home/$MY_USERNAME/README
	echo '' >> /home/$MY_USERNAME/README
	echo $'SIP Server' >> /home/$MY_USERNAME/README
	echo '==========' >> /home/$MY_USERNAME/README
	echo $"SIP onion_domain: $SIP_ONION_HOSTNAME" >> /home/$MY_USERNAME/README
	echo $"SIP server username: $MY_USERNAME" >> /home/$MY_USERNAME/README
	echo $"SIP server extension: 201" >> /home/$MY_USERNAME/README
	echo $"SIP server password: $SIP_SERVER_PASSWORD" >> /home/$MY_USERNAME/README
	chown $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME/README
	chmod 600 /home/$MY_USERNAME/README
    fi

    function_check configure_firewall_for_sip4
    configure_firewall_for_sip4
    echo 'install_sip_main' >> $COMPLETION_FILE
}

function install_sip_turn {
    if grep -Fxq "install_sip_turn" $COMPLETION_FILE; then
	return
    fi

    apt-get -y install turnserver

    # create a nonce if needed
    if [ ! $VOIP_TURN_NONCE ]; then
	VOIP_TURN_NONCE="$(create_password 30)"
    fi

    function_check create_site_certificate
    create_site_certificate $DEFAULT_DOMAIN_NAME

    echo '##' > /etc/turnserver/turnserver.conf
    echo '# TurnServer configuration file.' >> /etc/turnserver/turnserver.conf
    echo '#' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Public IPv4 address of any relayed address (if not set, no relay for IPv4).' >> /etc/turnserver/turnserver.conf
    echo '## To have multiple address, separate addresses with a comma' >> /etc/turnserver/turnserver.conf
    echo '## (i.e. listen_address = { "172.16.0.1", "172.17.0.1" }).' >> /etc/turnserver/turnserver.conf
    echo "listen_address = { \"192.168.0.1\" }" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Public IPv6 address of any relayed address (if not set, no relay for IPv6).' >> /etc/turnserver/turnserver.conf
    echo '## To have multiple address, separate address with a comma' >> /etc/turnserver/turnserver.conf
    echo '## (i.e. listen_addressv6 = { "2001:db8:1::1", "2001:db8:2::1" }).' >> /etc/turnserver/turnserver.conf
    echo "#listen_addressv6 = { \"2001:db8::1\" }" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## UDP listening port.' >> /etc/turnserver/turnserver.conf
    echo "udp_port = $VOIP_TURN_PORT" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## TCP listening port.' >> /etc/turnserver/turnserver.conf
    echo "tcp_port = $VOIP_TURN_PORT" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## TLS listening port.' >> /etc/turnserver/turnserver.conf
    echo "tls_port = $VOIP_TURN_TLS_PORT" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## TLS support.' >> /etc/turnserver/turnserver.conf
    echo 'tls = true' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## DTLS support. It is an experimental feature and is not defined in TURN' >> /etc/turnserver/turnserver.conf
    echo '## standard.' >> /etc/turnserver/turnserver.conf
    echo 'dtls = false' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Maximum allocation port number.' >> /etc/turnserver/turnserver.conf
    echo 'max_port = 65535' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Minimum allocation port number.' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo 'min_port = 49152' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## TURN-TCP support.' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo 'turn_tcp = true' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## TURN-TCP buffering mode:' >> /etc/turnserver/turnserver.conf
    echo '## - true, use userspace buffering;' >> /etc/turnserver/turnserver.conf
    echo '## - false, use kernel buffering.' >> /etc/turnserver/turnserver.conf
    echo 'tcp_buffer_userspace = true' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## TURN-TCP maximum buffer size.' >> /etc/turnserver/turnserver.conf
    echo 'tcp_buffer_size = 32768' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Daemon mode.' >> /etc/turnserver/turnserver.conf
    echo 'daemon = true' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Unprivileged user.' >> /etc/turnserver/turnserver.conf
    echo '## If you want to use this feature create a system user.' >> /etc/turnserver/turnserver.conf
    echo '## On Linux: adduser --system --group turnserver' >> /etc/turnserver/turnserver.conf
    echo 'unpriv_user = turnserver' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Realm value.' >> /etc/turnserver/turnserver.conf
    echo "realm = \"$DEFAULT_DOMAIN_NAME\"" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Nonce key.' >> /etc/turnserver/turnserver.conf
    echo "nonce_key = \"$VOIP_TURN_NONCE\"" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Max relay per username.' >> /etc/turnserver/turnserver.conf
    echo 'max_relay_per_username = 5' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Allocation lifetime.' >> /etc/turnserver/turnserver.conf
    echo 'allocation_lifetime = 1800' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Allocation bandwidth limitation (in KBytes/s).' >> /etc/turnserver/turnserver.conf
    echo '## 0 value means bandwidth quota disabled.' >> /etc/turnserver/turnserver.conf
    echo 'bandwidth_per_allocation = 150' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Restricted user bandwidth (in KBytes/s).' >> /etc/turnserver/turnserver.conf
    echo '## 0 value means bandwidth limitation disabled.' >> /etc/turnserver/turnserver.conf
    echo 'restricted_bandwidth = 10' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Denied addresses.' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '# disallow relaying to localhost' >> /etc/turnserver/turnserver.conf
    echo 'denied_address {' >> /etc/turnserver/turnserver.conf
    echo '  address = "127.0.0.1"' >> /etc/turnserver/turnserver.conf
    echo '  mask = "8"' >> /etc/turnserver/turnserver.conf
    echo '  port = 0' >> /etc/turnserver/turnserver.conf
    echo '}' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '# disallow relaying to ip6-localhost' >> /etc/turnserver/turnserver.conf
    echo 'denied_address {' >> /etc/turnserver/turnserver.conf
    echo '  address = "::1"' >> /etc/turnserver/turnserver.conf
    echo '  mask = "128"' >> /etc/turnserver/turnserver.conf
    echo '  port = 0' >> /etc/turnserver/turnserver.conf
    echo '}' >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Certification Authority file.' >> /etc/turnserver/turnserver.conf
    echo "ca_file = \"/etc/ssl/certs/ca-certificates.crt\"" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Server certificate file.' >> /etc/turnserver/turnserver.conf
    if [ -f /etc/ssl/certs/$DEFAULT_DOMAIN_NAME.pem ]; then
	echo "cert_file = \"/etc/ssl/certs/$DEFAULT_DOMAIN_NAME.pem\"" >> /etc/turnserver/turnserver.conf
    else
	if [ -f /etc/ssl/certs/$DEFAULT_DOMAIN_NAME.crt ]; then
	    echo "cert_file = \"/etc/ssl/certs/$DEFAULT_DOMAIN_NAME.crt\"" >> /etc/turnserver/turnserver.conf
	fi
    fi
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Private key file.' >> /etc/turnserver/turnserver.conf
    echo "private_key_file = \"/etc/ssl/certs/$DEFAULT_DOMAIN_NAME.key\"" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Account method.' >> /etc/turnserver/turnserver.conf
    echo "account_method = \"file\"" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## Account file (if account_method = file).' >> /etc/turnserver/turnserver.conf
    echo "account_file = \"/etc/turnserver/turnusers.txt\"" >> /etc/turnserver/turnserver.conf
    echo '' >> /etc/turnserver/turnserver.conf
    echo '## mod_tmpuser.' >> /etc/turnserver/turnserver.conf
    echo 'mod_tmpuser = false' >> /etc/turnserver/turnserver.conf

    echo "${MY_USERNAME}:password:${DEFAULT_DOMAIN_NAME}:authorized" > /etc/turnserver/turnusers.txt

    systemctl restart turnserver

    function_check configure_firewall_for_voip_turn
    configure_firewall_for_voip_turn
    echo 'install_sip_turn' >> $COMPLETION_FILE
}

function install_sip {
    if grep -Fxq "install_sip" $COMPLETION_FILE; then
	return
    fi
    install_sip_main
    update_sipwitch_daemon
    echo 'install_sip' >> $COMPLETION_FILE
}

# NOTE: deliberately no exit 0