#!/bin/bash
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-10-06; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.live.builder.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: LicenseRef-CNCL-1.1 OR LicenseRef-CCLA-1.1
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.live.builder
# SPDX-Security-Contact: security@coresecret.eu

set -Ceuo pipefail
umask 0077

declare -gx   VAR_RDNS_DOMAIN=""             # Forward-confirmed reverse DNS domain.
declare -gx   VAR_RDNS_IPV4=""               # IPv4 address used for RDNS verification.
declare -gx   VAR_RDNS_NORMALIZED=""         # RDNS domain normalized for Primordial branch names.
declare -gx   VAR_PRIMORDIAL_KEY=""          # Primordial SSH identity filename.
declare -gx   VAR_PRIMORDIAL_SSH_PORT=""     # Primordial SSH port.
declare -gx   VAR_PRIMORDIAL_URL=""          # Primordial HTTPS Git URL.
declare -grx  VAR_SEMAPHORE="/root/cdi.ciss" # Semaphore to appear.
declare -girx VAR_TIMEOUT=3600               # Semaphore timer in seconds.

install -d -m 0755 /run/lock
exec 9> /run/lock/9999_cdi_starter.lock
flock -n 9 || { echo "9999_cdi_starter already running. Exiting."; exit 0; }

#######################################
# Call into the CISS.debian.installer once the semaphore file is present.
# Globals:
#   None
# Arguments:
#   None
# Returns:
#   0: on success
#######################################
cdi() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -i rc=""

  ./ciss_debian_installer.sh \
    --autoinstall \
    --debug XTRACE \
    --log debug \
    --reionice-priority 1 0 \
    --renice-priority "-19" \

  rc="$?"

  if [[ "${rc}" -eq 0 ]]; then

    ### In autoinstall mode this command should never be reached due to the reboot command inside ciss_debian_installer.sh.
    logger -t cdi-watcher "cdi(): ciss_debian_installer.sh completed SUCCESSFULLY [${rc}]."
    exit 0

  else

    logger -t cdi-watcher "cdi(): ciss_debian_installer.sh FAILED [${rc}]."
    exit "${rc}"

  fi
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f cdi

#######################################
# Wait for network connectivity by looping.
# Globals:
#   None
# Arguments:
#   None
# Returns:
#   0: on success
#######################################
net_wait() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -i i

  for ((i=1; i<=60; i++)); do

    if getent hosts git.coresecret.dev >/dev/null 2>&1; then

      return 0

    fi

    sleep 1

  done

  return 1
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f net_wait

#######################################
# Validate an IPv4 address.
# Globals:
#   None
# Arguments:
#   $1: IPv4 address
# Returns:
#   0: valid IPv4 address
#   1: invalid IPv4 address
#######################################
is_ipv4() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -r var_ip="${1:-}"
  declare -a ary_octets=()
  declare     var_octet=""

  [[ "${var_ip}" =~ ^([0-9]{1,3}\.){3}[0-9]{1,3}$ ]] || return 1

  IFS='.' read -r -a ary_octets <<< "${var_ip}"

  for var_octet in "${ary_octets[@]}"; do

    if ! ((10#${var_octet} <= 255)); then

      return 1

    fi

  done

  return 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f is_ipv4

#######################################
# Validate a DNS domain name returned by RDNS.
# Globals:
#   None
# Arguments:
#   $1: domain name
# Returns:
#   0: valid domain name
#   1: invalid domain name
#######################################
is_dns_name() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -r var_name="${1:-}"

  [[ "${#var_name}" -le 253 ]] || return 1
  [[ "${var_name}" =~ ^[A-Za-z0-9]([A-Za-z0-9-]{0,61}[A-Za-z0-9])?(\.[A-Za-z0-9]([A-Za-z0-9-]{0,61}[A-Za-z0-9])?)+$ ]] \
    || return 1

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

#######################################
# Retrieve and forward-confirm reverse DNS for the active IPv4 route.
# Globals:
#   VAR_RDNS_DOMAIN
#   VAR_RDNS_IPV4
# Arguments:
#   $1: module log file
# Returns:
#   0: on confirmed RDNS
#   1: on missing or unconfirmed RDNS
#######################################
# retrieve_rdns() intentionally probes optional resolver tools and validation helpers inside conditionals.
# shellcheck disable=SC2310,SC2312
retrieve_rdns() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -r var_log="${1:-}"
  declare -a ary_a=()
  declare -a ary_rdns=()
  declare -a ary_targets=()
  declare    var_a="" var_ipv4="" var_rdns="" var_target=""

  VAR_RDNS_DOMAIN=""
  VAR_RDNS_IPV4=""

  mapfile -t ary_targets < <(
    getent ahostsv4 git.coresecret.dev 2>/dev/null \
      | awk '/^([0-9]{1,3}\.){3}[0-9]{1,3}[[:space:]]/ && !seen[$1]++ { print $1 }'
  )
  ary_targets+=( "1.1.1.1" "9.9.9.9" "8.8.8.8" )

  if command -v ip >/dev/null 2>&1; then

    for var_target in "${ary_targets[@]}"; do

      if var_ipv4="$(
        ip -o -4 route get "${var_target}" 2>/dev/null \
          | awk '{ for (i = 1; i <= NF; i++) { if ($i == "src") { print $(i + 1); exit } } }'
      )" && is_ipv4 "${var_ipv4}"; then

        break

      fi

      var_ipv4=""

    done

    if [[ -z "${var_ipv4}" ]]; then

      mapfile -t ary_targets < <(
        ip -o -4 addr show scope global up 2>/dev/null \
          | awk '{ split($4, addr, "/"); if (!seen[addr[1]]++) { print addr[1] } }'
      )

      for var_target in "${ary_targets[@]}"; do

        if is_ipv4 "${var_target}"; then

          var_ipv4="${var_target}"
          break

        fi

      done

    fi

  fi

  if [[ -z "${var_ipv4}" ]]; then

    logger -t cdi-watcher "retrieve_rdns(): no active IPv4 address found; continuing without RDNS."
    printf "Command: [retrieve_rdns] no active IPv4 address found; continuing without RDNS.\n" >> "${var_log}"
    return 1

  fi

  if command -v dig >/dev/null 2>&1; then

    mapfile -t ary_rdns < <(
      dig +time=3 +tries=1 +short -x "${var_ipv4}" 2>/dev/null \
        | sed 's/[.]$//' \
        | awk 'NF && !seen[$0]++ { print $0 }'
    )

  fi

  if ((${#ary_rdns[@]} == 0)) && command -v host >/dev/null 2>&1; then

    mapfile -t ary_rdns < <(
      host "${var_ipv4}" 2>/dev/null \
        | awk '/domain name pointer/ { sub(/[.]$/, "", $NF); if (!seen[$NF]++) { print $NF } }'
    )

  fi

  if ((${#ary_rdns[@]} == 0)); then

    mapfile -t ary_rdns < <(
      getent hosts "${var_ipv4}" 2>/dev/null \
        | awk '{ for (i = 2; i <= NF; i++) { sub(/[.]$/, "", $i); if (!seen[$i]++) { print $i } } }'
    )

  fi

  for var_rdns in "${ary_rdns[@]}"; do

    var_rdns="${var_rdns%.}"
    var_rdns="${var_rdns,,}"

    if ! is_dns_name "${var_rdns}"; then

      continue

    fi

    ary_a=()

    if command -v dig >/dev/null 2>&1; then

      mapfile -t ary_a < <(
        dig +time=3 +tries=1 +short A "${var_rdns}" 2>/dev/null \
          | awk '/^([0-9]{1,3}\.){3}[0-9]{1,3}$/ && !seen[$0]++ { print $0 }'
      )

    fi

    if ((${#ary_a[@]} == 0)) && command -v host >/dev/null 2>&1; then

      mapfile -t ary_a < <(
        host -t A "${var_rdns}" 2>/dev/null \
          | awk '/ has address / && !seen[$NF]++ { print $NF }'
      )

    fi

    if ((${#ary_a[@]} == 0)); then

      mapfile -t ary_a < <(
        getent ahostsv4 "${var_rdns}" 2>/dev/null \
          | awk '!seen[$1]++ { print $1 }'
      )

    fi

    for var_a in "${ary_a[@]}"; do

      if is_ipv4 "${var_a}" && [[ "${var_a}" == "${var_ipv4}" ]]; then

        VAR_RDNS_IPV4="${var_ipv4}"
        VAR_RDNS_DOMAIN="${var_rdns}"
        logger -t cdi-watcher "retrieve_rdns(): confirmed IPv4 ${VAR_RDNS_IPV4} RDNS ${VAR_RDNS_DOMAIN}."
        printf "Command: [retrieve_rdns] confirmed IPv4 [%s] RDNS [%s].\n" \
          "${VAR_RDNS_IPV4}" "${VAR_RDNS_DOMAIN}" >> "${var_log}"
        return 0

      fi

    done

  done

  logger -t cdi-watcher "retrieve_rdns(): no forward-confirmed RDNS for IPv4 ${var_ipv4}; continuing without RDNS."
  printf "Command: [retrieve_rdns] no forward-confirmed RDNS for IPv4 [%s]; continuing without RDNS.\n" \
    "${var_ipv4}" >> "${var_log}"

  return 1
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f retrieve_rdns

#######################################
# Normalize a DNS domain into a Primordial branch name.
# Globals:
#   None
# Arguments:
#   $1: DNS domain name
# Returns:
#   0: on success
#   1: on invalid DNS domain
#######################################
normalize_rdns_domain() {
  ### Declare Arrays, HashMaps, and Variables.
  declare var_domain="${1:-}"

  var_domain="${var_domain%.}"
  var_domain="${var_domain,,}"

  # shellcheck disable=SC2310
  is_dns_name "${var_domain}" || return 1

  printf '%s\n' "${var_domain//./_}"

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

#######################################
# Convert an HTTPS Git URL into the SSH URL used for Primordial clone.
# Globals:
#   None
# Arguments:
#   $1: HTTPS Git URL
#   $2: SSH port
# Returns:
#   0: on success
#   1: on invalid URL or port
#######################################
derive_ssh_git_url() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -r var_https_url="${1:-}"
  declare -r var_ssh_port="${2:-}"
  declare    var_host="" var_path=""

  if [[ ! "${var_https_url}" =~ ^https://([A-Za-z0-9.-]+)/([A-Za-z0-9._~/%+=:@,-]+\.git)$ ]]; then

    return 1

  fi

  var_host="${BASH_REMATCH[1]}"
  var_path="${BASH_REMATCH[2]}"

  if [[ -z "${var_host}" || -z "${var_path}" || ! "${var_ssh_port}" =~ ^[0-9]+$ ]] \
    || ((10#${var_ssh_port} < 1 || 10#${var_ssh_port} > 65535)); then

    return 1

  fi

  printf 'ssh://git@%s:%s/%s\n' "${var_host}" "${var_ssh_port}" "${var_path}"

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

#######################################
# Apply the Primordial overlay and create the CDI semaphore only on success.
# Globals:
#   VAR_PRIMORDIAL_KEY
#   VAR_PRIMORDIAL_SSH_PORT
#   VAR_PRIMORDIAL_URL
#   VAR_RDNS_DOMAIN
#   VAR_RDNS_NORMALIZED
#   VAR_SEMAPHORE
# Arguments:
#   $1: module log file
#   $2: CISS.debian.installer directory
# Returns:
#   0: on success or optional skip
#   1: on failed configured Primordial overlay
#######################################
apply_primordial_overlay() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -r var_log="${1:-}"
  declare -r var_repo_dir="${2:-}"
  declare -r var_overlay_dir="/root/git/overlay"
  declare    var_identity="" var_ssh_url="" var_rdns_normalized=""

  if [[ -z "${VAR_PRIMORDIAL_URL}" && -z "${VAR_PRIMORDIAL_KEY}" && -z "${VAR_PRIMORDIAL_SSH_PORT}" ]]; then

    logger -t cdi-watcher "Primordial overlay not configured; continuing with existing semaphore polling."
    printf "Command: [apply_primordial_overlay] skipped; Primordial overlay not configured.\n" >> "${var_log}"
    return 0

  fi

  if ! rm -f -- "${VAR_SEMAPHORE}"; then

    logger -t cdi-watcher "Failed to remove existing CDI semaphore; aborting CDI autostart."
    printf "Command: [rm -f -- %s] failed; aborting CDI autostart.\n" "${VAR_SEMAPHORE}" >> "${var_log}"
    return 1

  fi

  if [[ -z "${VAR_PRIMORDIAL_URL}" || -z "${VAR_PRIMORDIAL_KEY}" || -z "${VAR_PRIMORDIAL_SSH_PORT}" || -z "${VAR_RDNS_DOMAIN}" ]]; then

    logger -t cdi-watcher "Primordial overlay configuration incomplete; aborting CDI autostart."
    printf "Command: [apply_primordial_overlay] failed; Primordial URL, key, SSH port, and RDNS domain are required.\n" >> "${var_log}"
    return 1

  fi

  # shellcheck disable=SC2310
  if ! var_rdns_normalized="$(normalize_rdns_domain "${VAR_RDNS_DOMAIN}")"; then

    logger -t cdi-watcher "Primordial overlay RDNS branch derivation failed; aborting CDI autostart."
    printf "Command: [normalize_rdns_domain %s] failed; aborting CDI autostart.\n" "${VAR_RDNS_DOMAIN}" >> "${var_log}"
    return 1

  fi

  declare -gx VAR_RDNS_NORMALIZED="${var_rdns_normalized}"

  # shellcheck disable=SC2310
  if ! var_ssh_url="$(derive_ssh_git_url "${VAR_PRIMORDIAL_URL}" "${VAR_PRIMORDIAL_SSH_PORT}")"; then

    logger -t cdi-watcher "Primordial HTTPS Git URL conversion failed; aborting CDI autostart."
    printf "Command: [derive_ssh_git_url] failed for configured Primordial URL; aborting CDI autostart.\n" >> "${var_log}"
    return 1

  fi

  var_identity="/root/.ssh/${VAR_PRIMORDIAL_KEY}"

  if [[ ! -e "${var_identity}" ]]; then

    logger -t cdi-watcher "Primordial SSH identity file is missing; aborting CDI autostart."
    printf "Command: [test -e /root/.ssh/<primordial-key>] failed; aborting CDI autostart.\n" >> "${var_log}"
    return 1

  fi

  if [[ ! -f "${var_identity}" ]]; then

    logger -t cdi-watcher "Primordial SSH identity path is not a regular file; aborting CDI autostart."
    printf "Command: [test -f /root/.ssh/<primordial-key>] failed; aborting CDI autostart.\n" >> "${var_log}"
    return 1

  fi

  if [[ ! -r "${var_identity}" ]]; then

    logger -t cdi-watcher "Primordial SSH identity file is not readable by root; aborting CDI autostart."
    printf "Command: [test -r /root/.ssh/<primordial-key>] failed; aborting CDI autostart.\n" >> "${var_log}"
    return 1

  fi

  if ! rm -rf -- "${var_overlay_dir}"; then

    logger -t cdi-watcher "Failed to remove existing Primordial overlay directory; aborting CDI autostart."
    printf "Command: [rm -rf -- %s] failed; aborting CDI autostart.\n" "${var_overlay_dir}" >> "${var_log}"
    return 1

  fi

  if ! GIT_SSH_COMMAND="ssh -i ${var_identity} -p ${VAR_PRIMORDIAL_SSH_PORT}" \
    git clone --branch "${VAR_RDNS_NORMALIZED}" "${var_ssh_url}" "${var_overlay_dir}"; then

    logger -t cdi-watcher "Primordial overlay clone failed; aborting CDI autostart."
    printf "Command: [git clone --branch %s <primordial-ssh-url> %s] failed; aborting CDI autostart.\n" \
      "${VAR_RDNS_NORMALIZED}" "${var_overlay_dir}" >> "${var_log}"
    rm -rf -- "${var_overlay_dir}" || true
    return 1

  fi

  if [[ ! -d "${var_overlay_dir}/.preseed" ]]; then

    logger -t cdi-watcher "Primordial overlay .preseed directory is missing; aborting CDI autostart."
    printf "Command: [test -d %s/.preseed] failed; aborting CDI autostart.\n" "${var_overlay_dir}" >> "${var_log}"
    return 1

  fi

  if [[ ! -d "${var_overlay_dir}/includes" ]]; then

    logger -t cdi-watcher "Primordial overlay includes directory is missing; aborting CDI autostart."
    printf "Command: [test -d %s/includes] failed; aborting CDI autostart.\n" "${var_overlay_dir}" >> "${var_log}"
    return 1

  fi

  install -d -m 0700 "${var_repo_dir}/.preseed" "${var_repo_dir}/includes"

  if ! rsync -av "${var_overlay_dir}/.preseed/" "${var_repo_dir}/.preseed/"; then

    logger -t cdi-watcher "Primordial overlay .preseed rsync failed; aborting CDI autostart."
    printf "Command: [rsync -av %s/.preseed/ %s/.preseed/] failed; aborting CDI autostart.\n" \
      "${var_overlay_dir}" "${var_repo_dir}" >> "${var_log}"
    return 1

  fi

  if ! rsync -av "${var_overlay_dir}/includes/" "${var_repo_dir}/includes"; then

    logger -t cdi-watcher "Primordial overlay includes rsync failed; aborting CDI autostart."
    printf "Command: [rsync -av %s/includes/ %s/includes] failed; aborting CDI autostart.\n" \
      "${var_overlay_dir}" "${var_repo_dir}" >> "${var_log}"
    return 1

  fi

  if ! install -m 0600 /dev/null "${VAR_SEMAPHORE}"; then

    logger -t cdi-watcher "Primordial overlay applied but semaphore creation failed; aborting CDI autostart."
    printf "Command: [install -m 0600 /dev/null %s] failed; aborting CDI autostart.\n" "${VAR_SEMAPHORE}" >> "${var_log}"
    return 1

  fi

  logger -t cdi-watcher "Primordial overlay applied for branch ${VAR_RDNS_NORMALIZED}; CDI semaphore created."
  printf "Command: [apply_primordial_overlay] executed for branch [%s].\n" "${VAR_RDNS_NORMALIZED}" >> "${var_log}"

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

#######################################
# Wrapper for loading CISS hardened Kernel Parameters.
# Globals:
#   None
# Arguments:
#   None
# Returns:
#   0: on success
#######################################
sysp() {
  sysctl -p /etc/sysctl.d/90-ciss-local.hardened

  # shellcheck disable=SC2312
  sysctl -a | grep -E '^(kernel|vm|net)\.' >| "/var/log/sysctl_check_$(date +'%Y-%m-%d_%H-%M-%S').log"

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

#######################################
# Main autostart function.
# Arguments:
#   None
#######################################
main() {
  ### Declare Arrays, HashMaps, and Variables.
  declare -r  var_repo_url="https://git.coresecret.dev/msw/CISS.debian.installer.git"
  declare -r  var_repo_dir="/root/git/CISS.debian.installer"
  declare -i  i=""
  declare     var_log="" var_mode=""

  ### Prepare logging.
  install -d -m 0700 /root/.ciss/cdi
  install -d -m 0700 /root/.ciss/cdi/log
  var_log="/root/.ciss/cdi/log/9999-cdi-starter_$(date +"%Y-%m-%d_%H-%M-%S").log"
  touch "${var_log}"

  printf "CISS.debian.live.builder V9.14.024.2026.06.11 calling CISS.debian.installer ... \n" >> "${var_log}"

  ### Sleep a moment to settle boot artifacts.
  sleep 8

  ### Harden Kernel parameters.
  printf "Command: [sysp] to be executed ... \n" >> "${var_log}"
  sysp
  printf "Command: [sysp] executed.\n" >> "${var_log}"

  ### Wait for network connectivity.
  printf "Command: [net_wait] to be executed ... \n" >> "${var_log}"
  # shellcheck disable=SC2310
  if ! net_wait; then

    logger -t cdi-watcher "Network/DNS not available after 60s; skipping online bootstrap."
    printf "Command: [net_wait] no DNS/network after 60s; skipping apt/git bootstrap.\n" >> "${var_log}"
    ### Do not mark the service as failed when the system is simply offline.
    exit 0

  fi
  printf "Command: [net_wait] executed.\n" >> "${var_log}"

  ### Retrieve forward-confirmed reverse DNS.
  printf "Command: [retrieve_rdns] to be executed ... \n" >> "${var_log}"
  # shellcheck disable=SC2310
  retrieve_rdns "${var_log}" || true
  printf "Command: [retrieve_rdns] executed.\n" >> "${var_log}"

  ### apt update.
  if ! apt-get update >> "${var_log}"; then

    logger -t cdi-watcher "apt-get update failed; continuing without package refresh."
    printf "Command: [apt-get update] failed; continuing without package refresh.\n" >> "${var_log}"

  fi

  ### Download CISS.debian.installer.
  install -d -m 0700 /root/git
  cd /root/git

  [[ -d "${var_repo_dir}" ]] && rm -rf "${var_repo_dir}"

  if ! git clone "${var_repo_url}" "${var_repo_dir}"; then

    logger -t cdi-watcher "git clone of ${var_repo_url} failed; aborting CDI autostart."
    printf "Command: [git clone %s %s] failed; aborting CDI autostart.\n" "${var_repo_url}" "${var_repo_dir}" >> "${var_log}"
    exit 0

  fi

  chmod 0700 "${var_repo_dir}/ciss_debian_installer.sh"
  cd "${var_repo_dir}"
  printf "Command: [git clone %s %s] executed.\n" "${var_repo_url}" "${var_repo_dir}" >> "${var_log}"

  ### Apply Primordial overlay before allowing CDI autostart.
  # shellcheck disable=SC2310
  if ! apply_primordial_overlay "${var_log}" "${var_repo_dir}"; then

    logger -t cdi-watcher "Primordial overlay failed; CDI autostart aborted before semaphore polling."
    printf "Command: [apply_primordial_overlay] failed; CDI autostart aborted before semaphore polling.\n" >> "${var_log}"
    exit 0

  fi

  ### Poll up to VAR_TIMEOUT seconds for the semaphore to appear and be mode 0600.
  for ((i=0; i<VAR_TIMEOUT; i++)); do

    if [[ -e "${VAR_SEMAPHORE}" && ! -s "${VAR_SEMAPHORE}" ]]; then

      var_mode="$(stat -c '%a' -- "${VAR_SEMAPHORE}" 2>/dev/null || echo '?')"

      if [[ "${var_mode}" == "600" ]]; then

        logger -t cdi-watcher "Semaphore found (${VAR_SEMAPHORE}, mode 0600) after ${i}s -> invoking cdi()"
        printf "Command: [cdi] to be executed.\n" >> "${var_log}"

        cdi
        ### cdi() never returns (it exits the script), so no code below this point in the 'then'-block will run.

      else

        logger -t cdi-watcher "Semaphore ${VAR_SEMAPHORE} present but wrong mode ${var_mode} (expected 600); ignoring"
        printf "INFO: [Semaphore %s present but wrong mode %s (expected 600); ignoring] executed.\n" "${VAR_SEMAPHORE}" "${var_mode}" >> "${var_log}"

      fi

    fi

    sleep 1

  done

  ### Timeout reached without acceptable semaphore.
  logger -t cdi-watcher "No valid semaphore ${VAR_SEMAPHORE} (mode 0600) within ${VAR_TIMEOUT}s; exiting idle."
  printf "CISS.debian.live.builder V9.14.024.2026.06.11: No valid semaphore [%s] within [%s]s.\n" "${VAR_SEMAPHORE}" "${VAR_TIMEOUT}" >> "${var_log}"

  exit 0
}
### Prevents accidental 'unset -f'.
# shellcheck disable=SC2034
readonly -f main

main "$@"

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