#!/usr/bin/env bash

# -------------------------------------------------------------------------- #
# Copyright 2002-2021, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
# not use this file except in compliance with the License. You may obtain    #
# a copy of the License at                                                   #
#                                                                            #
# http://www.apache.org/licenses/LICENSE-2.0                                 #
#                                                                            #
# Unless required by applicable law or agreed to in writing, software        #
# distributed under the License is distributed on an "AS IS" BASIS,          #
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
# See the License for the specific language governing permissions and        #
# limitations under the License.                                             #
#--------------------------------------------------------------------------- #

#
# network module implementation
#

is_network_supported()
{
    command -v netplan >/dev/null

    return $?
}

configure_network()
{
    init_netplan_renderer

    gen_resolvconf
    gen_network_configuration > /etc/netplan/50-one-context.yaml
    netplan generate
    nm_symlink_run_connections

    # On Debian 10 and Ubuntu 18.04 the initial netplan apply is needed to
    # set some interface parameters (e.g., MTU). Unfortunately, this deadlocks
    # booting of current systems, so we execute netplan apply on the background
    case "${NETCFG_NETPLAN_RENDERER}" in
        ''|networkd)
            flock /var/run/one-context/netplan.lock nohup netplan apply &>/dev/null &
            ;;
    esac
}

stop_network()
{
    service networking stop
}

start_network()
{
    netplan generate
    nm_symlink_run_connections
    service networking start
    flock /var/run/one-context/netplan.lock netplan apply
}

reload_network()
{
    netplan generate
    nm_symlink_run_connections
    flock /var/run/one-context/netplan.lock netplan apply
}

#
# helper functions
#

# TODO: remove global variables and get rid off exports
#
# to satisfy shellcheck SC2154:
export os_id
export ip
export network
export mask
export cidr
export ip6
export ip6_prefix_length
export ip6_ula
export mac
export dev
export mtu
export gateway
export ip6_gateway
export method
export ip6_method
export metric
export ip6_metric
export dns
export search_domains
export external
export detach
export all_nameservers
export all_search_domains

gen_addresses()
{
    case "${method}" in
        ''|static)
            [ -n "${ip}" ] && gen_addr_conf
            ;;
    esac

    case "${ip6_method}" in
        ''|static)
            [ -n "${ip6}" ] && gen_addr6_conf
            ;;
    esac

    _aliases=$(get_interface_alias "$_iface")

    for _nic_alias in $_aliases; do
        setup_ipadr_vars "$_nic_alias"
        setup_ip6adr_vars "$_nic_alias"
        setup_alias_vars "$_nic_alias"

        if [ -z "${detach}" ]; then
            if ! is_true "${external}" ; then
                [ -n "${ip}"  ] && gen_addr_conf
                [ -n "${ip6}" ] && gen_addr6_conf
            fi
        fi
    done
}

gen_routes()
{
    if [ -n "${gateway}" ] && { [ -z "${method}" ] || [ "${method}" = 'static' ]; }; then
        cat <<EOT
        - to: "0.0.0.0/0"
          via: ${gateway}
EOT



        # Force default Linux IPv4 metric (man 8 route) to override
        # automatic metrics calculation done by NetworkManager and unify
        # behavior among different renderers.
        metric=${metric:-0}

        if [ -n "${metric}" ] ; then
            echo "          metric: ${metric}"
        fi
    fi

    # Add static routes
    if [ -n "${static_routes}" ]; then

        IFS=',' read -r -a routes <<< "$static_routes"

        for route in "${routes[@]}"
        do
            rsplit=( ${route} )
            dst="${rsplit[0]}"
            gw="${rsplit[2]}"

        cat <<EOT
        - to: "${dst}"
          via: "${gw}"
EOT
            done

        fi

    # Add ONEGATE Proxy static route ip route replace 169.254.16.9 dev eth0
    if missing_onegate_proxy_route; then
        cat <<EOT
        - to: "${onegate_host}/32"
          scope: link
EOT

        unset onegate_proxy_route_missing
    fi

    if [ -n "${ip6_gateway}" ] && { [ -z "${ip6_method}" ] || [ "${ip6_method}" = 'static' ]; }; then
        cat <<EOT
        - to: "::/0"
          via: ${ip6_gateway}
EOT

        # Force default Linux IPv6 metric (man 8 route) to override
        # automatic metrics calculation done by NetworkManager and unify
        # behavior among different renderers.
        ip6_metric=${ip6_metric:-1}

        if [ -n "${ip6_metric}" ] ; then
            echo "          metric: ${ip6_metric}"
        fi
    fi
}

gen_dhcp_conf()
{
    cat <<EOT
      dhcp4: true
EOT
}

gen_addr_conf()
{
    echo "        - ${ip}/${cidr}"
}

gen_addr6_conf()
{
    echo "        - ${ip6}/${ip6_prefix_length:-64}"

    if [ -n "$ip6_ula" ]; then
        echo "        - ${ip6_ula}/64"
    fi
}

gen_dhcp6_conf()
{
    if [ "${ip6_method}" = "auto" ] ; then
        cat <<EOT
      accept-ra: true
      dhcp6: false
EOT
    else
        cat <<EOT
      accept-ra: true
      dhcp6: true
EOT
    fi

    cat <<EOT
      ipv6-privacy: false
EOT
}

gen_ipv6_disable()
{
    cat <<EOT
      accept-ra: false
      link-local: []
EOT
}

# Old NM doesn't read from /run/NetworkManager/system-connections,
# so the generated Netplan configuration is not respected. As a workaround,
# we symlink the connection files into /etc
nm_symlink_run_connections()
{
    if [ "${NETCFG_NETPLAN_RENDERER}" != 'NetworkManager' ] ||
       ! [ -d /run/NetworkManager/system-connections ];
    then
        return
    fi

    # cleanup any old symlinks
    rm -f /etc/NetworkManager/system-connections/netplan-*

    case "$(NetworkManager --version 2>/dev/null)" in
        1.14.*) # Debian 10
            echo "WARNING: Symlinking NM's ephemeral connections into /etc" >&2
            ;;
        *)
            return
            ;;
    esac

    # symlink Netplan connection files
    for _src in /run/NetworkManager/system-connections/netplan-*; do
        if [ -f "${_src}" ]; then
            _dst="/etc/NetworkManager/system-connections/$(basename "${_src}")"
            ln -s "${_src}" "${_dst}"
        fi
    done
}

init_netplan_renderer()
{
    if [ -z "${NETCFG_NETPLAN_RENDERER}" ] ; then
        if command -v networkctl >/dev/null ; then
            NETCFG_NETPLAN_RENDERER='networkd'
        elif command -v nmcli >/dev/null ; then
            NETCFG_NETPLAN_RENDERER='NetworkManager'
        else
            # fallback to networkd only not to leave the variable
            # uninitialized, deployment most likely won't work!
            NETCFG_NETPLAN_RENDERER='networkd'
        fi
    else
        # support alternative names for some configuration renderers
        _netcfg_netplan_renderer=$(echo "$NETCFG_NETPLAN_RENDERER" | \
            sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' | \
            tr '[:upper:]' '[:lower:]')

        # normalize renderer names and support alternatives
        case "${_netcfg_netplan_renderer}" in
            systemd-networkd|systemd-network|systemd|networkd)
                NETCFG_NETPLAN_RENDERER='networkd'
                ;;
            networkmanager|nm)
                NETCFG_NETPLAN_RENDERER='NetworkManager'
                ;;
        esac
    fi
}

gen_network_configuration()
{
    if [ "${NETCFG_NETPLAN_RENDERER}" = 'NetworkManager' ]; then

        # since Ubuntu 22.04 and newer networkd systemd-networkd-wait-online
        # started to timeout+fail with NETCFG_TYPE='interfaces' or 'nm' (including netplan+nm)
        _networkd_version=$(networkctl --version 2>/dev/null | head -1 | awk '{print $2}')
        if [ $_networkd_version -ge 249 ]; then
            systemctl disable --now systemd-networkd-wait-online.service
        fi

        nm_enable
    fi

    cat <<EOT
# Generated by one-context
network:
  version: 2
  renderer: ${NETCFG_NETPLAN_RENDERER}
EOT

    # ethernets key must have at least one interface
    _ethernets_written=

    _context_interfaces=$(get_context_interfaces)

    for _iface in $_context_interfaces; do
        setup_iface_vars "$_iface"

        skip_interface && continue

        if [ -z "${_ethernets_written}" ] ; then
            echo "  ethernets:"
            _ethernets_written=yes
        fi
        echo "    ${dev}:"

        if [ -n "${mtu}" ]; then
            echo "      mtu: ${mtu}"
        fi

        ## Requires Netplan 0.98+
        # if [ -n "${mtu}" ]; then
        #     echo "      ip6-mtu: ${mtu}"
        # fi

        case "${method}" in
            ''|static)
                : # in gen_addresses
                ;;
            dhcp)
                gen_dhcp_conf
                ;;
        esac

        case "${ip6_method}" in
            ''|static)
                : # in gen_addresses
                ;;
            auto|dhcp)
                gen_dhcp6_conf
                ;;
            disable)
                gen_ipv6_disable
                ;;
        esac

        _addresses=$(gen_addresses)
        if [ -n "${_addresses}" ] ; then
            echo "      addresses:"
            echo "${_addresses}"
        fi

        _routes=$(gen_routes)
        if [ -n "${_routes}" ] ; then
            echo "      routes:"
            echo "${_routes}"
        fi
    done
}