#!/bin/bash
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

guard_sourcing

#######################################
# Setup network.
# Globals:
#   ARY_IPV4_NS
#   ARY_IPV6_NS
#   TARGET
#   VAR_ARCHITECTURE
#   VAR_CODENAME
#   VAR_FINAL_IPV4
#   VAR_FINAL_IPV4_GW
#   VAR_FINAL_IPV4_SUBNET
#   VAR_FINAL_IPV6
#   VAR_FINAL_IPV6_GW
#   VAR_FINAL_IPV6_SUBNET
#   VAR_FINAL_NIC
#   VAR_LINK_IPV6
#   VAR_VERSION
#   network_autoconfig_enable
#   network_choose_interface_auto
#   network_static_ipv4nameserver_0
#   network_static_ipv6address
#   network_static_ipv6nameserver_0
# Arguments:
#  None
# Returns:
#   0: on success
#######################################
installation_network() {
  ### Declare Arrays, HashMaps, and Variables.
  declare     var_supersede="" var_supersede_ipv6=""

  do_in_target "${TARGET}" apt-get install -y isc-dhcp-client ifupdown
  mkdir -p "${TARGET}/etc/network/interfaces.d"

  ### Create a network configuration file header.
  if [[ -f "${TARGET}/etc/network/interfaces" ]]; then
    mkdir -p "${TARGET}/root/.ciss/cdi/backup/etc/network"
    mv "${TARGET}/etc/network/interfaces" "${TARGET}/root/.ciss/cdi/backup/etc/network/interfaces.bak"
    do_log "info" "file_only" "4300() Existing '${TARGET}/etc/network/interfaces' moved."
  fi

  cat << EOF >| "${TARGET}/etc/network/interfaces"
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

# /etc/network/interfaces      : Generated by CISS.debian.installer ${VAR_VERSION}
# Architecture                 : ${VAR_ARCHITECTURE}
# Distribution                 : ${VAR_CODENAME}

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
EOF
  chmod 0644 "${TARGET}/etc/network/interfaces"
  do_log "info" "file_only" "4300() Header '${TARGET}/etc/network/interfaces' created."

  ### Configure network interfaces based on 'preseed.yaml' and create network configuration files for IPv4.
  if [[ "${network_autoconfig_enable}" == "true" && "${network_choose_interface_auto}" == "true" ]]; then

    ### Reminder ###
    # auto:
    # For servers or systems with static interfaces that should always be available (e.g., eth0 on a server).
    # For configurations where the interface should be active regardless of the cable status.
    # allow-hotplug:
    # For systems with dynamic or removable network devices (e.g., laptops or USB adapters).
    # To avoid boot delays when interfaces are unavailable.

    cat << EOF >| "${TARGET}/etc/network/interfaces.d/10-ipv4-dhcp"
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

# /etc/network/interfaces      : Generated by CISS.debian.installer ${VAR_VERSION}
# Architecture                 : ${VAR_ARCHITECTURE}
# Distribution                 : ${VAR_CODENAME}

# The primary network interface IPv4
auto ${VAR_FINAL_NIC}
iface ${VAR_FINAL_NIC} inet dhcp

# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
EOF
    chmod 0644 "${TARGET}/etc/network/interfaces.d/10-ipv4-dhcp"
    do_log "info" "file_only" "4300() IPv4 on the primary NIC: '${VAR_FINAL_NIC}' configured with DHCP."

  elif [[ "${network_autoconfig_enable}" == "true" && "${network_choose_interface_auto}" == "false" ]]; then

    cat << EOF >| "${TARGET}/etc/network/interfaces.d/10-ipv4-dhcp"
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

# /etc/network/interfaces      : Generated by CISS.debian.installer ${VAR_VERSION}
# Architecture                 : ${VAR_ARCHITECTURE}
# Distribution                 : ${VAR_CODENAME}

# The primary network interface IPv4
auto ${VAR_FINAL_NIC}
iface ${VAR_FINAL_NIC} inet dhcp

# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
EOF
    chmod 0644 "${TARGET}/etc/network/interfaces.d/10-ipv4-dhcp"
    do_log "info" "file_only" "4300() IPv4 on the primary NIC: '${VAR_FINAL_NIC}' configured with DHCP."

  fi

  if [[ "${network_autoconfig_enable}" == "false" ]]; then

    # shellcheck disable=SC2153
    cat << EOF >| "${TARGET}/etc/network/interfaces.d/10-ipv4-static"
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

# /etc/network/interfaces      : Generated by CISS.debian.installer ${VAR_VERSION}
# Architecture                 : ${VAR_ARCHITECTURE}
# Distribution                 : ${VAR_CODENAME}

# The primary network interface IPv4
auto ${VAR_FINAL_NIC}
iface ${VAR_FINAL_NIC} inet static
    address ${VAR_FINAL_IPV4}
    netmask ${VAR_FINAL_IPV4_SUBNET}
    gateway ${VAR_FINAL_IPV4_GW}
    dns-nameservers ${ARY_IPV4_NS[*]}

# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
EOF
    chmod 0644  "${TARGET}/etc/network/interfaces.d/10-ipv4-static"
    do_log "info" "file_only" "4300() IPv4 on the primary NIC: '${VAR_FINAL_NIC}' configured statically."

  fi

  ### Configure network interfaces based on 'preseed.yaml' and create network configuration files for IPv6.
  if [[ "${network_autoconfig_enable}" == "true" && "${VAR_LINK_IPV6}" == "true" ]]; then

    cat << EOF >| "${TARGET}/etc/network/interfaces.d/10-ipv6-dhcp"
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

# /etc/network/interfaces      : Generated by CISS.debian.installer ${VAR_VERSION}
# Architecture                 : ${VAR_ARCHITECTURE}
# Distribution                 : ${VAR_CODENAME}

# The primary network interface IPv6
auto ${VAR_FINAL_NIC}
iface ${VAR_FINAL_NIC} inet6 dhcp

# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
EOF
    chmod 0644 "${TARGET}/etc/network/interfaces.d/10-ipv6-dhcp"
    do_log "info" "file_only" "4300() IPv6 on the primary NIC: '${VAR_FINAL_NIC}' configured with DHCP."

  fi

  if [[ "${network_autoconfig_enable}" == "false" && -n "${network_static_ipv6address}" ]]; then

    # shellcheck disable=SC2153
    cat << EOF >| "${TARGET}/etc/network/interfaces.d/10-ipv6-static"
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-06-17; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.installer
# SPDX-Security-Contact: security@coresecret.eu

# The primary network interface IPv6
auto ${VAR_FINAL_NIC}
iface ${VAR_FINAL_NIC} inet6 static
    address ${VAR_FINAL_IPV6}/${VAR_FINAL_IPV6_SUBNET}
    gateway ${VAR_FINAL_IPV6_GW}
    dns-nameservers ${ARY_IPV6_NS[*]}

# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
EOF
    chmod 0644 "${TARGET}/etc/network/interfaces.d/10-ipv6-static"
    do_log "info" "file_only" "4300() IPv6 on the primary NIC: '${VAR_FINAL_NIC}' configured statically."

  fi

  ### Ensure Internet Systems Consortium DHCP Client is not overwriting the static nameserver settings.
  if [[ -f "${TARGET}/etc/dhcp/dhclient.conf" ]]; then
    mkdir -p "${TARGET}/root/.ciss/cdi/backup/etc/dhcp"
    cp "${TARGET}/etc/dhcp/dhclient.conf" "${TARGET}/root/.ciss/cdi/backup/etc/dhcp/dhclient.conf.bak"
    do_log "info" "file_only" "4300() Existing '${TARGET}/etc/dhcp/dhclient.conf' copied."
  fi

  if [[ "${network_autoconfig_enable}" == "true" && -n "${network_static_ipv4nameserver_0}" ]]; then

    cat << EOF >> "${TARGET}/etc/dhcp/dhclient.conf"

# Custom dhclient config to override DHCP DNS
EOF
    var_supersede=$(printf "%s, " "${ARY_IPV4_NS[@]}")
    var_supersede="${var_supersede%, }"
    echo "supersede domain-name-servers ${var_supersede};" >> "${TARGET}/etc/dhcp/dhclient.conf"

    do_log "info" "file_only" "4300() DHCP client configuration for IPv4: '${TARGET}/etc/dhcp/dhclient.conf' configured."

  fi

  if [[ "${network_autoconfig_enable}" == "false" && -n "${network_static_ipv6nameserver_0}" ]]; then

    var_supersede_ipv6=$(printf "%s, " "${ARY_IPV6_NS[@]}")
    var_supersede_ipv6="${var_supersede_ipv6%, }"
    echo "supersede domain-name-servers ${var_supersede_ipv6};" >> "${TARGET}/etc/dhcp/dhclient.conf"

    do_log "info" "file_only" "4300() DHCP client configuration for IPv6: '${TARGET}/etc/dhcp/dhclient.conf' configured."

  fi

  if [[ "${network_autoconfig_enable}" == "true" && -n "${network_static_ipv4nameserver_0}" ]]; then

    cat << EOF >> "${TARGET}/etc/dhcp/dhclient.conf"

# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
EOF
  fi

  guard_dir && return 0
}
# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh
