#!/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

#######################################
# Extended dynamic network variable checks and declarations depending on preseed.yaml.
# Globals:
#   ARY_IPV4_NS
#   ARY_IPV6_NS
#   VAR_FINAL_FQDN
#   VAR_FINAL_IPV4
#   VAR_FINAL_IPV4_GW
#   VAR_FINAL_IPV4_SUBNET
#   VAR_FINAL_IPV6
#   VAR_FINAL_IPV6_CIDR
#   VAR_FINAL_IPV6_GW
#   VAR_FINAL_NIC
#   VAR_LINK_IPV6
#   network_autoconfig_enable
#   network_choose_interface_static
#   network_hostname
#   network_ipv6
#   network_static_ipv4address
#   network_static_ipv4gateway
#   network_static_ipv4nameserver_0
#   network_static_ipv4nameserver_1
#   network_static_ipv4nameserver_2
#   network_static_ipv4nameserver_3
#   network_static_ipv4nameserver_fallback_0
#   network_static_ipv4nameserver_fallback_1
#   network_static_ipv4netmask
#   network_static_ipv6address
#   network_static_ipv6gateway
#   network_static_ipv6nameserver_0
#   network_static_ipv6nameserver_1
#   network_static_ipv6nameserver_2
#   network_static_ipv6nameserver_3
#   network_static_ipv6nameserver_fallback_0
#   network_static_ipv6nameserver_fallback_1
#   network_static_ipv6netmask
# Arguments:
#   None
# Returns:
#   0: on success
#######################################
yaml_validator() {
  ### Declare Arrays, HashMaps, and Variables.
  # shellcheck disable=SC2034
  declare -ag ARY_IPV4_NS=() ARY_IPV6_NS=()
  declare     var_auto_nic="" var_auto_ipv4="" var_auto_ipv4_cidr="" var_auto_ipv4_subnet="" var_auto_ipv4_gw="" \
              var_auto_ipv6="" var_auto_ipv6_cidr="" var_auto_ipv6_gw="" var_link_ipv4="" var_link_ipv6="" var_auto_fqdn=""
  declare -gx VAR_FINAL_NIC="" VAR_FINAL_FQDN="" VAR_FINAL_IPV4="" VAR_FINAL_IPV4_GW="" VAR_FINAL_IPV4_SUBNET="" \
              VAR_FINAL_IPV6="" VAR_LINK_IPV6="" VAR_FINAL_IPV6_GW="" VAR_FINAL_IPV6_CIDR=""

  ensure_lowercase "network_autoconfig_enable"
  ensure_lowercase "network_choose_interface_auto"
  ensure_lowercase "network_choose_interface_static"
  ensure_lowercase "network_hostname"

  # shellcheck disable=SC2034
  [[ -v network_static_ipv4nameserver_0 ]] && ARY_IPV4_NS+=( "${network_static_ipv4nameserver_0}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv4nameserver_1 ]] && ARY_IPV4_NS+=( "${network_static_ipv4nameserver_1}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv4nameserver_2 ]] && ARY_IPV4_NS+=( "${network_static_ipv4nameserver_2}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv4nameserver_3 ]] && ARY_IPV4_NS+=( "${network_static_ipv4nameserver_3}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv4nameserver_fallback_0 ]] && ARY_IPV4_NS+=( "${network_static_ipv4nameserver_fallback_0}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv4nameserver_fallback_1 ]] && ARY_IPV4_NS+=( "${network_static_ipv4nameserver_fallback_1}" )

  # shellcheck disable=SC2034
  [[ -v network_static_ipv6nameserver_0 ]] && ARY_IPV6_NS+=( "${network_static_ipv6nameserver_0}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv6nameserver_1 ]] && ARY_IPV6_NS+=( "${network_static_ipv6nameserver_1}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv6nameserver_2 ]] && ARY_IPV6_NS+=( "${network_static_ipv6nameserver_2}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv6nameserver_3 ]] && ARY_IPV6_NS+=( "${network_static_ipv6nameserver_3}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv6nameserver_fallback_0 ]] && ARY_IPV6_NS+=( "${network_static_ipv6nameserver_fallback_0}" )
  # shellcheck disable=SC2034
  [[ -v network_static_ipv6nameserver_fallback_1 ]] && ARY_IPV6_NS+=( "${network_static_ipv6nameserver_fallback_1}" )

  ### Check current network connection and configure variables
  # shellcheck disable=SC2312
  var_auto_nic=$(ip -o link show | awk -F': ' '/state UP/ && $2!="lo" {print $2; exit}')

  # shellcheck disable=SC2312
  var_auto_ipv4_cidr=$(ip -4 -o addr show "${var_auto_nic}" | awk '{print $4; exit}')

  # shellcheck disable=SC2312
  var_auto_ipv4_subnet=$(generate_subnetmask "${var_auto_ipv4_cidr}")

  # shellcheck disable=SC2312
  var_auto_ipv4=$(echo "${var_auto_ipv4_cidr}" | awk -F'/' '{print $1}')

  # shellcheck disable=SC2312
  var_auto_ipv4_gw=$(ip route show default dev "${var_auto_nic}" | awk '/^default/ {print $3; exit}')

  # shellcheck disable=SC2312
  var_auto_ipv6_cidr=$(ip -6 -o addr show "${var_auto_nic}" | awk '/scope global/ {print $4; exit}')

  if [[ -n "${var_auto_ipv6_cidr}" ]]; then

    # shellcheck disable=SC2312
    var_auto_ipv6=$(echo "${var_auto_ipv6_cidr}" | awk -F'/' '{print $1}')
    # shellcheck disable=SC2312
    var_auto_ipv6_gw=$(ip -6 route show default dev "${var_auto_nic}" | awk '/^default/ {print $3; exit}')

  fi

  # shellcheck disable=SC2312
  var_link_ipv4="$(probe_link 4 heise.de)"
  #var_link_ipv4=$(ping -q -c 1 -W 1 -4 heise.de > /dev/null 2>&1 && echo "true" || echo "false")

  # shellcheck disable=SC2312
  var_link_ipv6="$(probe_link 6 heise.de)"
  #var_link_ipv6=$(ping -q -c 1 -W 1 -6 heise.de > /dev/null 2>&1 && echo "true" || echo "false")

  # shellcheck disable=SC2312
  var_auto_fqdn="$( getent hosts "${var_auto_ipv4}" | awk '{print $2}' | head -n1 )"
  var_auto_fqdn="${var_auto_fqdn:-$(dig +short -x "${var_auto_ipv4}")}"
  var_auto_fqdn="${var_auto_fqdn%.}"
  var_auto_fqdn="${var_auto_fqdn,,}"

  do_log "info" "file_only" "1252() Live environment network check: Auto NIC          = ${var_auto_nic}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv4         = ${var_auto_ipv4}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv4 CCIDR   = ${var_auto_ipv4_cidr}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv4 Subnet  = ${var_auto_ipv4_subnet}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv4 Gateway = ${var_auto_ipv4_gw}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv6         = ${var_auto_ipv6}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv6 CCIDR   = ${var_auto_ipv6_cidr}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv6 Gateway = ${var_auto_ipv6_gw}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv4 Link    = ${var_link_ipv4}"
  do_log "info" "file_only" "1252() Live environment network check: Auto IPv6 Link    = ${var_link_ipv6}"
  do_log "info" "file_only" "1252() Live environment network check: Auto FQDN         = ${var_auto_fqdn}"

  ### Export hostname and IPv4 and IPv6 addresses for further processing according to dynamic results and preseed.yaml settings.
  if [[ "${network_autoconfig_enable}" == "true" ]]; then

    # shellcheck disable=SC2034
    VAR_FINAL_NIC="${var_auto_nic}"
    # shellcheck disable=SC2034
    VAR_FINAL_FQDN="${var_auto_fqdn}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV4="${var_auto_ipv4}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV4_GW="${var_auto_ipv4_gw}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV4_SUBNET="${var_auto_ipv4_subnet}"

    do_log "info" "file_only" "1252() Network IPv4 auto configuration: [${network_autoconfig_enable}] and IPv4 Link: [${var_link_ipv4}]."

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

    # shellcheck disable=SC2034
    VAR_FINAL_NIC="${network_choose_interface_static}"
    # shellcheck disable=SC2034
    VAR_FINAL_FQDN="${network_hostname}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV4="${network_static_ipv4address}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV4_GW="${network_static_ipv4gateway}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV4_SUBNET="${network_static_ipv4netmask}"

    do_log "info" "file_only" "1252() Network IPv4 static configuration: [${network_static_ipv4address}] and IPv4 Link: [${var_link_ipv4}]."

  elif [[ "${network_autoconfig_enable}" == "false" && -z "${network_static_ipv4address}" ]]; then

    do_log "info" "file_only" "1252() Network IPv4: no IPv4 configuration applied."

  fi


  if [[ "${network_autoconfig_enable}" == "true" && "${network_ipv6}" == "true" && -z "${network_static_ipv6address}" ]]; then

    # shellcheck disable=SC2034
    VAR_FINAL_IPV6="${var_auto_ipv6}"
    # shellcheck disable=SC2034
    VAR_LINK_IPV6="${var_link_ipv6}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV6_GW="${var_auto_ipv6_gw}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV6_CIDR="${var_auto_ipv6_cidr}"

    do_log "info" "file_only" "1252() Network IPv6 auto configuration: [${network_autoconfig_enable}] and IPv6 Link: [${var_link_ipv6}]."

  elif [[ -n "${network_static_ipv6address}" ]]; then

    # shellcheck disable=SC2034
    VAR_FINAL_IPV6="${network_static_ipv6address}"
    # shellcheck disable=SC2034
    VAR_LINK_IPV6="${var_link_ipv6}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV6_GW="${network_static_ipv6gateway}"
    # shellcheck disable=SC2034
    VAR_FINAL_IPV6_CIDR="${network_static_ipv6address}/${network_static_ipv6netmask}"

    do_log "info" "file_only" "1252() Network IPv6 static configuration: [${network_static_ipv6address}] and IPv6 Link: [${var_link_ipv6}]."

  else

    # shellcheck disable=SC2034
    VAR_FINAL_IPV6=""
    do_log "info" "file_only" "1252() Network IPv6: no IPv6 configuration applied."

  fi

  guard_dir && return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f yaml_validator

#######################################
# Network connectivity prober.
# Globals:
#   network_timeout_linkwait
# Arguments:
#   1: IP-Family
#   2: TLD to probe
# Returns:
#   0: on success
#######################################
probe_link() {
  declare -r  var_fam="${1:-4}"           # "4" or "6"
  declare -r  var_target="${2:-heise.de}" # hostname or IP
  declare     var_ok="false"

  ### 1) Try ping (quiet, 1 probe, 3s deadline)
  if ping -q -c 1 -W "${network_timeout_linkwait:-3}" "-${var_fam}" "${var_target}" >/dev/null 2>&1; then

    var_ok="true"

  else

    ### 2) Fallback: mtr in report mode (non-interactive), no DNS to avoid TUI/delays.
    if command -v mtr >/dev/null 2>&1; then

      ### Treat as success if ANY hop resolves to something other than "???".
      ### '-r = report', '-c 2 = two cycles', -n = no DNS, -4/-6 = address family

      # shellcheck disable=SC2312
      if mtr "-${var_fam}" -r -c 3 -n "${var_target}" 2>/dev/null \
        | awk 'NR>2 && $2!="???"{ok=1} END{exit ok?0:1}'; then

        var_ok="true"

      fi

    fi

  fi

  printf '%s' "${var_ok}"
  return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f probe_link
# vim: number et ts=2 sw=2 sts=2 ai tw=128 ft=sh