#!/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.
#

AP_CONN="BorderRouter-AP"
ETH_CONN="BorderRouter-Eth"

AP_HELPER_SCRIPT="/etc/NetworkManager/dispatcher.d/ap-helper"
DHCPV6_HELPER_SCRIPT="/etc/NetworkManager/dispatcher.d/dhcpv6-helper"

create_ap_connection()
{
    IFNAME=$(nmcli d | grep wifi | cut -d" " -f1)

    sudo nmcli c add type wifi ifname "${IFNAME}" con-name ${AP_CONN} ssid ${AP_CONN}
    sudo nmcli c modify ${AP_CONN} 802-11-wireless.mode ap 802-11-wireless.band bg ipv4.method shared ipv6.method auto
    sudo nmcli c modify ${AP_CONN} wifi-sec.key-mgmt wpa-psk
    sudo nmcli c modify ${AP_CONN} wifi-sec.proto rsn
    sudo nmcli c modify ${AP_CONN} wifi-sec.psk "12345678"
}

create_eth_connection()
{
    IFNAME=$(nmcli d | grep ethernet | cut -d" " -f1 | grep -v usb)

    sudo nmcli c add type ethernet ifname "${IFNAME}" con-name ${ETH_CONN}
    sudo nmcli c modify ${ETH_CONN} ipv6.method ignore
}

create_ap_helper_script()
{
    sudo tee ${AP_HELPER_SCRIPT} <<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.
#

set -euxo pipefail

NAME="ap-helper"

IFNAME=\$1
ACTION=\$2

AP_CONN="${AP_CONN}"

DHCP_START="10.42.0.2"
DHCP_END="10.42.0.8"

ROUTER_IP="10.42.0.1"

DNS1=\${ROUTER_IP}
DNS2="8.8.8.8"


log()
{
    logger -t "\${NAME}[\${\$}]" \$*
}

disable_accept_ra()
{
    log "Disable accepting Router Advertisements on the interface: '\${IFNAME}'"
    sysctl -w net.ipv6.conf.\${IFNAME}.accept_ra=1
}

start_dnsmasq()
{
    log "Starting 'dnsmasq' on the interface: '\${IFNAME}'"
    /usr/sbin/dnsmasq -i \${IFNAME} -a \${ROUTER_IP} -b -z -K -F\${DHCP_START},\${DHCP_END},24h -p0 -O3,\${ROUTER_IP} -O6,\${DNS1},\${DNS2}
}

kill_dnsmasq()
{
    local DNSMASQ_PID=\`pidof dnsmasq\`

    if [ -n \${DNSMASQ_PID} ]; then
        log "Killing 'dnsmasq' process with PID: '\${DNSMASQ_PID}'"
        kill -9 \${DNSMASQ_PID}
    else
        log "'dnsmasq' is not running"
    fi
}

release_dhcpcd()
{
    log "Releasing 'dhcpcd' on the interface: '\${IFNAME}'"
    /sbin/dhcpcd -6 -k \${IFNAME}
}

handle_action_up()
{
    case \${IFNAME} in
    wlan*)
        if [ \${CONNECTION_ID} = \${AP_CONN} ]; then
            release_dhcpcd
            disable_accept_ra
            start_dnsmasq
        fi
        ;;
    *)
        ;;
    esac
}

handle_action_down()
{
    case \${IFNAME} in
    wlan*)
        if [ \${CONNECTION_ID} = \${AP_CONN} ]; then
            kill_dnsmasq
        fi
        ;;
    *)
        log "Skipping action: '\${ACTION}' on the interface: '\${IFNAME}'"
        ;;
    esac
}


case \${ACTION} in
up)
    handle_action_up
    ;;
down)
    handle_action_down
    ;;
*)
    log "Unsupported action: '\${ACTION}'"
    ;;
esac
EOF
}

create_dhcpv6_helper_script()
{
    sudo tee ${DHCPV6_HELPER_SCRIPT} <<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.
#  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.
#

set -euxo pipefail

NAME="dhcpv6-helper"

IFNAME=\$1
ACTION=\$2

AP_CONN="${AP_CONN}"

DHCPCD_INTERFACES="/tmp/dhcpcd_interfaces"


log()
{
    logger -t "\${NAME}[\${\$}]" \$*
}

enable_accept_ra()
{
    log "Enable accepting Router Advertisements on the interface: '\${IFNAME}'"
    sysctl -w net.ipv6.conf.\${IFNAME}.accept_ra=2
}

kill_dnsmasq()
{
    local DNSMASQ_PID=\`pidof dnsmasq\`

    log "Killing 'dnsmasq' process with PID: '\${DNSMASQ_PID}'"
    kill -9 \${DNSMASQ_PID}
}

start_dhcpcd()
{
    log "Starting 'dhcpcd' on the interface: '\${IFNAME}'"
    /sbin/dhcpcd -6 -b -K -E \${IFNAME}

    # Add interface to active dhcpcd interfaces.
    sed -i "/\${IFNAME}/d" \${DHCPCD_INTERFACES}
    echo "\${IFNAME}" >> \${DHCPCD_INTERFACES}
}

release_dhcpcd()
{
    log "Releasing 'dhcpcd' on the interface: '\${IFNAME}'"
    /sbin/dhcpcd -6 -k \${IFNAME}

    # Remove interface from active dhcpcd interfaces.
    sed -i "/\${IFNAME}/d" \${DHCPCD_INTERFACES}
}

handle_action_up()
{
    case \${IFNAME} in
    enp*)
        enable_accept_ra
        start_dhcpcd
        ;;
    eth*)
        enable_accept_ra
        start_dhcpcd
        ;;
    wlan*)
        if ! [ \${CONNECTION_ID} = \${AP_CONN} ]; then
            enable_accept_ra
            start_dhcpcd
        fi
        ;;
    *)
        ;;
    esac

}

handle_action_down()
{
    case \${IFNAME} in
    enp*)
        release_dhcpcd
        ;;
    eth*)
        release_dhcpcd
        ;;
    wlan*)
        if ! [ \${CONNECTION_ID} = \${AP_CONN} ]; then
            release_dhcpcd
        fi
        ;;
    *)
        log "Skipping action: '\${ACTION}' on the interface: '\${IFNAME}'"
        ;;
    esac
}

case \${ACTION} in
up)
    handle_action_up
    ;;
down)
    handle_action_down
    ;;
*)
    log "Unsupported action: '\${ACTION}'"
    ;;
esac
EOF
}

network_manager_install()
{
    with NETWORK_MANAGER || return 0

    if ! have systemctl; then
        echo "This script requires systemctl!"
        return 0
    fi

    if with DNS64; then
        # bind9 provides DNS service
        sudo sed -i 's/^#port=5353/port=0/g' /etc/dnsmasq.conf
        sudo systemctl restart dnsmasq
    fi

    sudo systemctl daemon-reload

    sudo systemctl stop wpa_supplicant || true
    sudo systemctl disable wpa_supplicant || true

    sudo systemctl stop dhcpcd || true
    sudo systemctl disable dhcpcd || true

    sudo systemctl daemon-reload

    sudo systemctl start NetworkManager || die "Failed to start NetworkManager."
    sudo systemctl enable NetworkManager || die "Failed to enable NetworkManager."

    # Create AP connection only on raspbian platform.
    if [ "$PLATFORM" = raspbian ] || with NETWORK_MANAGER_WIFI; then
        create_ap_helper_script
        sudo chmod a+x ${AP_HELPER_SCRIPT}

        create_ap_connection
    fi

    create_dhcpv6_helper_script
    sudo chmod a+x ${DHCPV6_HELPER_SCRIPT}

    create_eth_connection

    sudo systemctl daemon-reload
    sudo systemctl restart NetworkManager

    sleep 15

    if [ "$PLATFORM" = raspbian ] || with NETWORK_MANAGER_WIFI; then
        sudo nmcli c up ${AP_CONN}
    fi

    sudo nmcli c up ${ETH_CONN}
}

network_manager_uninstall()
{
    with NETWORK_MANAGER || return 0

    if with DNS64; then
        sudo systemctl stop dnsmasq
        # revert changes to dnsmasq
        sudo sed -i 's/^port=0/#port=5353/g' /etc/dnsmasq.conf
    fi

    if ! have systemctl; then
        echo "This script requires systemctl!"
        return 0
    fi

    if ! systemctl is-active NetworkManager; then
        sudo systemctl daemon-reload
        sudo systemctl start NetworkManager
    fi

    if [ "$PLATFORM" = raspbian ] || with NETWORK_MANAGER_WIFI; then
        sudo nmcli c down ${AP_CONN} || true
        sudo nmcli c delete ${AP_CONN} || true
    fi

    sudo nmcli c down ${ETH_CONN} || true
    sudo nmcli c delete ${ETH_CONN} || true

    sudo systemctl disable NetworkManager || die 'Failed to disable NetworkManager!'
    sudo systemctl stop NetworkManager || die 'Failed to stop NetworkManager!'

    sudo rm ${AP_HELPER_SCRIPT} || true
    sudo rm ${DHCPV6_HELPER_SCRIPT} || true

    sudo systemctl daemon-reload

    sudo systemctl start dhcpcd || true
    sudo systemctl enable dhcpcd || true

    sudo systemctl start wpa_supplicant || true
    sudo systemctl enable wpa_supplicant || true
}