Harden dnsmasq setup and fix restart diagnostic exit codes

update_and_deploy_fips.sh

@@ -200,7 +200,7 @@ restart_unit_with_diagnostics() {
   local output rc
 
   if command -v timeout >/dev/null 2>&1; then
-    if ! output="$(sudo timeout "${timeout_seconds}" systemctl restart "${unit}" 2>&1)"; then
+    output="$(sudo timeout "${timeout_seconds}" systemctl restart "${unit}" 2>&1)" || {
       rc=$?
       echo "Error: failed to restart ${unit} (exit ${rc})." >&2
       if [[ ${rc} -eq 124 ]]; then
@@ -213,9 +213,9 @@ restart_unit_with_diagnostics() {
       sudo journalctl -u "${unit}" -n "${journal_lines}" --no-pager >&2 || true
       [[ "${required}" == "yes" ]] && return 1
       return 0
-    fi
+    }
   else
-    if ! output="$(sudo systemctl restart "${unit}" 2>&1)"; then
+    output="$(sudo systemctl restart "${unit}" 2>&1)" || {
       rc=$?
       echo "Error: failed to restart ${unit} (exit ${rc})." >&2
       [[ -n "${output}" ]] && printf '%s\n' "${output}" >&2
@@ -225,7 +225,7 @@ restart_unit_with_diagnostics() {
       sudo journalctl -u "${unit}" -n "${journal_lines}" --no-pager >&2 || true
       [[ "${required}" == "yes" ]] && return 1
       return 0
-    fi
+    }
   fi
 
   if ! sudo systemctl is-active --quiet "${unit}"; then
@@ -259,6 +259,11 @@ ensure_dnsmasq_package() {
     echo "Warning: unable to auto-install dnsmasq on this distro." >&2
     return 1
   fi
+
+  if ! command -v dnsmasq >/dev/null 2>&1; then
+    echo "Warning: dnsmasq command is still unavailable after package install." >&2
+    return 1
+  fi
 }
 
 configure_dnsmasq_fips_dns() {
@@ -277,6 +282,7 @@ configure_dnsmasq_fips_dns() {
   fi
 
   echo "==> Configuring dnsmasq for .fips forwarding"
+  sudo mkdir -p "$(dirname "${conf_file}")"
   tmp_file="$(mktemp)"
   cat > "${tmp_file}" <<EOF
 # Managed by update_and_deploy_fips.sh
@@ -313,8 +319,13 @@ EOF
     fi
   fi
 
-  sudo systemctl enable dnsmasq.service >/dev/null 2>&1 || true
-  restart_unit_with_diagnostics "dnsmasq.service" "no"
+  if sudo systemctl list-unit-files dnsmasq.service --no-legend 2>/dev/null | grep -q '^dnsmasq\.service'; then
+    sudo systemctl enable dnsmasq.service >/dev/null 2>&1 || true
+    restart_unit_with_diagnostics "dnsmasq.service" "no"
+  else
+    echo "Warning: dnsmasq.service unit not found; install/enable dnsmasq manually." >&2
+    return 1
+  fi
 }
 
 ensure_build_toolchain