#!/bin/bash
#
#  Copyright (c) 2017, The OpenThread Authors.
#  All rights reserved.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions are met:
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#  3. Neither the name of the copyright holder nor the
#     names of its contributors may be used to endorse or promote products
#     derived from this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
#  POSSIBILITY OF SUCH DAMAGE.
#
#   Description:
#       This script manipulates DHCPv6-PD configuration.
#
#
# Currently solution was verified only on raspbian.
#

if [ "$PLATFORM" = "ubuntu" ]; then
    WAN_INTERFACE="enp0s3"
else
    WAN_INTERFACE="eth0"
fi

WLAN_INTERFACE="wlan0"
WPAN_INTERFACE="wpan0"

DHCPCD_CONF="/etc/dhcpcd.conf"
DHCPCD_CONF_BACKUP="$DHCPCD_CONF.orig"

NCP_STATE_NOTIFIER="/usr/sbin/ncp_state_notifier"
NCP_STATE_DISPATCHER="/etc/ncp_state_notifier/dispatcher.d"

NCP_STATE_NOTIFIER_SERVICE_NAME="ncp_state_notifier.service"
NCP_STATE_NOTIFIER_SERVICE="/etc/systemd/system/${NCP_STATE_NOTIFIER_SERVICE_NAME}"

DHCPCD_RELOADER="${NCP_STATE_DISPATCHER}/dhcpcd_reloader"

without DHCPV6_PD || test "$PLATFORM" = beagleboneblack || test "$PLATFORM" = raspbian || test "$PLATFORM" = ubuntu || die "DHCPv6-PD is not tested under $PLATFORM."

create_dhcpcd_conf_with_dhcpv6_pd()
{
    sudo tee ${DHCPCD_CONF} <<EOF
# A sample configuration for dhcpcd.
# See dhcpcd.conf(5) for details.

# Allow users of this group to interact with dhcpcd via the control socket.
#controlgroup wheel

# Inform the DHCP server of our hostname for DDNS.
hostname

# Use the hardware address of the interface for the Client ID.
#clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
duid

# Rapid commit support.
# Safe to enable by default because it requires the equivalent option set
# on the server to actually work.
option rapid_commit

# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
# Most distributions have NTP support.
option ntp_servers
# Respect the network MTU.
# Some interface drivers reset when changing the MTU so disabled by default.
#option interface_mtu

# A ServerID is required by RFC2131.
require dhcp_server_identifier

# Generate Stable Private IPv6 Addresses instead of hardware based ones
slaac hwaddr

# A hook script is provided to lookup the hostname if not set by the DHCP
# server, but it should not be run by default.
nohook lookup-hostname
nohook wpa_supplicant

denyinterfaces nat*

noipv6rs

interface $WPAN_INTERFACE
nodhcp
nodhcp6

interface $WAN_INTERFACE
iaid 1
ipv6rs
ia_na 2
ia_pd 3/::/63 $WPAN_INTERFACE/1

EOF

    if [ "$PLATFORM" = "raspbian" ] || with NETWORK_MANAGER_WIFI; then
        sudo tee -a ${DHCPCD_CONF} <<EOF
interface $WLAN_INTERFACE
iaid 4
ipv6rs
ia_na 5
ia_pd 6/::/63 $WPAN_INTERFACE/1
EOF
    fi
}

create_ncp_state_notifier_script()
{
    sudo tee ${NCP_STATE_NOTIFIER} <<EOF
#!/bin/sh
#
#  Copyright (c) 2017, The OpenThread Authors.
#  All rights reserved.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions are met:
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#  3. Neither the name of the copyright holder nor the
#     names of its contributors may be used to endorse or promote products
#     derived from this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
#  POSSIBILITY OF SUCH DAMAGE.
#
#   Description:
#       This script notifies about NCP state changes.
#

set -euxo pipefail

PID=\$\$
NAME="ncp_state_notifier"

DISPATCHER_PATH="${NCP_STATE_DISPATCHER}"

echo \${PID} > "/tmp/\${NAME}.pid"

if [ -z \${IFACE} ]; then
    IFACE=${WPAN_INTERFACE}
fi

OTBR_PATH="/io/openthread/BorderRouter/\${IFACE}"

WATCH1="type='signal', interface=org.freedesktop.DBus.Properties, path=\${OTBR_PATH}, member='PropertiesChanged'"

notify_about_state()
{
    logger -t "\${NAME}[\${PID}]" "Notifying about change state to: \${1} on the interface: \${2}"

    for SCRIPT in \`find \${DISPATCHER_PATH} -type f\`; do
        logger -t "\${NAME}[\${PID}]" "Running script: \${SCRIPT}"
        .\${SCRIPT} \${1} \${2}
    done
}

process_output()
{
    local NEXT_LINE_IS_STATE=0

    while read -r LINE; do
        if echo \${LINE} | grep -q "NCP:State"; then
            NEXT_LINE_IS_STATE=1
            continue
        fi

        if [ \${NEXT_LINE_IS_STATE} -eq 1 ]; then
            NEXT_LINE_IS_STATE=1

            STATE=\`echo \${LINE} | cut -d'"' -f2\`
            notify_about_state \${STATE} \${IFACE}
        fi
    done
}

dbus-monitor --system "\${WATCH1}" | process_output
EOF
}

create_dhcpcd_reloader_script()
{
    sudo tee ${DHCPCD_RELOADER} <<EOF
#!/bin/sh
#
#  Copyright (c) 2017, The OpenThread Authors.
#  All rights reserved.
#
#  Redistribution and use in source and binary forms, with or without
#  modification, are permitted provided that the following conditions are met:
#  1. Redistributions of source code must retain the above copyright
#     notice, this list of conditions and the following disclaimer.
#  2. Redistributions in binary form must reproduce the above copyright
#     notice, this list of conditions and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#  3. Neither the name of the copyright holder nor the
#     names of its contributors may be used to endorse or promote products
#     derived from this software without specific prior written permission.
#
#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
#  POSSIBILITY OF SUCH DAMAGE.
#
#   Description:
#       This script reloads dhcpcd.
#

PID=\$\$
NAME="dhcpcd_reloader"

DHCPCD_INTERFACES="/tmp/dhcpcd_interfaces"

STATE=\$1

if [ \${STATE} = "associated" ]; then
    if systemctl is-active NetworkManager; then
        logger -t "\${NAME}[\${PID}]" "NetworkManager: active"

        if ! [ -f \${DHCPCD_INTERFACES} ]; then
            exit 1
        fi

        for interface in \`cat \${DHCPCD_INTERFACES}\`; do
            logger -t "\${NAME}[\${PID}]" "dhcpcd: rebind on the interface: \${interface}"
            /sbin/dhcpcd -6 -n \${interface}
        done
    fi

    if systemctl is-active dhcpcd; then
        logger -t "\${NAME}[\${PID}]" "dhcpcd: reload"

        sudo systemctl reload-daemon
        sudo systemctl force-reload dhcpcd
    fi
fi
EOF
}

create_ncp_state_notifier_service()
{
    sudo tee ${NCP_STATE_NOTIFIER_SERVICE} <<EOF
[Unit]
Description=Daemon call scripts on every NCP state change
After=otbr-agent.service
ConditionPathExists=${NCP_STATE_NOTIFIER}

[Service]
ExecStart=/bin/sh ${NCP_STATE_NOTIFIER}
PIDFile=/tmp/ncp_state_notifier.pid
KillMode=control-group

[Install]
WantedBy=multi-user.target
EOF
}

dhcpv6_pd_install()
{
    with DHCPV6_PD || return 0

    # Create backup of the default configuration of dhcpcd
    sudo mv ${DHCPCD_CONF} ${DHCPCD_CONF_BACKUP}

    create_dhcpcd_conf_with_dhcpv6_pd

    create_ncp_state_notifier_script
    sudo chmod +x ${NCP_STATE_NOTIFIER}

    sudo mkdir -p ${NCP_STATE_DISPATCHER}

    create_dhcpcd_reloader_script
    sudo chmod +x ${DHCPCD_RELOADER}

    if have systemctl; then
        create_ncp_state_notifier_service

        sudo systemctl daemon-reload

        if systemctl is-active NetworkManager; then
            sudo systemctl restart NetworkManager || die "Unable to restart NetworkManager!"
        fi

        if systemctl is-active dhcpcd; then
            sudo systemctl restart dhcpcd || die 'Unable to restart dhcpcd!'
        fi

        sudo systemctl start ${NCP_STATE_NOTIFIER_SERVICE_NAME} || die "Unable to start ${NCP_STATE_NOTIFIER_SERVICE_NAME}!"
        sudo systemctl enable ${NCP_STATE_NOTIFIER_SERVICE_NAME} || die "Unable to enable ${NCP_STATE_NOTIFIER_SERVICE_NAME}!"
    fi
}

dhcpv6_pd_uninstall()
{
    with DHCPV6_PD || return 0

    if have systemctl; then
        sudo systemctl disable ${NCP_STATE_NOTIFIER_SERVICE_NAME} || true
        sudo systemctl stop ${NCP_STATE_NOTIFIER_SERVICE_NAME} || true

        sudo rm ${NCP_STATE_NOTIFIER_SERVICE} || true
    fi

    sudo rm ${NCP_STATE_NOTIFIER} || true
    sudo rm ${DHCPCD_RELOADER} || true

    sudo rm -r ${NCP_STATE_DISPATCHER} || true

    # Restore backup of the default configuration of dhcpcd
    sudo mv ${DHCPCD_CONF_BACKUP} ${DHCPCD_CONF} || true

    # Restart dhcpcd or NetworkManager
    if have systemctl; then
        sudo systemctl daemon-reload

        if systemctl is-active NetworkManager; then
            sudo systemctl restart NetworkManager || true
        fi

        if systemctl is-active dhcpcd; then
            sudo systemctl restart dhcpcd || true
        fi
    fi
}