Configuration backup/restore and custom sensors on the flash drive

README.md

@@ -59,15 +59,15 @@ Do not reinstall or run upstream FanCtrl Plus while FanCtrl Plus 2 is installed.
 
 ## Custom temperature sensors
 
-Any sensor the plugin does not know about can be added as a script. Drop an
-executable file in:
+Any sensor the plugin does not know about can be added as a readable script with
+a valid shebang. Place the file in:
 
 ```text
 /boot/config/plugins/fanctrlplus2/sensors.d/
 ```
 
-Each executable in that directory becomes one auxiliary sensor, named after the
-file, selectable per fan alongside the built-in sources. The contract is:
+Each readable script in that directory becomes one auxiliary sensor, named
+after the file, selectable per fan alongside the built-in sources. The contract is:
 
 - print the temperature in degrees Celsius and nothing else (a fractional
   reading is truncated to whole degrees);
@@ -79,10 +79,9 @@ driven by its other sources, and the script is tried again on the next round.
 Errors are reported by the exit status, never by a sentinel reading: a script
 that prints `0` has reported 0 °C.
 
-Readings are clamped to 0–200 °C, as they are for every other source, so a
-value outside that range drives the fan at the corresponding end of its curve
-rather than being discarded. A script that reads 0 °C when the settings page
-is opened is taken for a dead sensor and is not offered in the list.
+Readings below −100 °C or above 300 °C are rejected as implausible; valid negative
+readings are floored at 0 °C. A script that reads 0 °C when the settings page is
+opened is taken for an unpopulated sensor and is not offered in the list.
 
 ```sh
 #!/bin/bash
@@ -92,7 +91,28 @@ temp=$(some-tool --read-ambient 2>/dev/null) || exit 1
 echo "$temp"
 ```
 
-Remember to make the file executable (`chmod +x`).
+The flash drive does not need executable permissions. The plugin makes a private
+executable copy on runtime storage, preserving the shebang and using the file's
+current contents on each read. The copy is removed after the reading finishes.
+Use absolute paths for helper files: `$0` refers to the runtime copy, not the
+original flash-resident script.
+
+## Configuration backup and restore
+
+Use **General Settings → Export backup** to download saved fan configurations,
+PWM labels, dashboard switches, and fan ordering as a JSON file. Unsaved edits,
+custom sensor scripts, runtime history, and logs are not included.
+
+**Restore backup** asks for confirmation before replacing saved settings. The
+entire file is validated before changes are made, and unrelated files such as
+`sensors.d/` remain untouched. Fan control retains its prior running or stopped
+state; a failed replacement restores the previous managed configuration files.
+Reloading after a successful restore shows the restored settings.
+
+Store backups somewhere other than the Unraid flash drive. Back up custom sensor
+scripts separately. Restored USB identities are resolved by the existing device
+migration at service startup; a missing or ambiguous recorded controller is not
+assigned to another device.
 
 ## Fan identity and USB port changes
 

src/usr/local/emhttp/plugins/fanctrlplus2/fanctrlplus2.page

@@ -59,6 +59,8 @@ HTML;
 
 <?PHP
 $cfg_dir = "/boot/config/plugins/$plugin";
+require_once "$docroot/plugins/$plugin/include/ConfigBackup.php";
+$page_config_lock = fcp_config_lock($cfg_dir);
 
 // Load the shared fan-block renderer.
 require_once "$docroot/plugins/$plugin/include/FanBlockRender.php";
@@ -133,8 +135,6 @@ foreach ([false, true] as $temporary) {
 $pwms = list_pwm();
 $disks = list_valid_disks_by_id();
 $width = 300;
-$cpu_sensors = detect_cpu_sensors();
-$aux_sensors = detect_aux_sensors();
 
 // Read a dashboard-tile switch (e.g. __FCP_AIRFLOW__, __FCP_HISTORY__).
 function fcp_labels_flag_enabled(string $cfg_dir, string $flag): bool {
@@ -152,6 +152,10 @@ function fcp_labels_flag_enabled(string $cfg_dir, string $flag): bool {
 
 $fcp_airflow_enabled = fcp_labels_flag_enabled($cfg_dir, '__FCP_AIRFLOW__');
 $fcp_history_enabled = fcp_labels_flag_enabled($cfg_dir, '__FCP_HISTORY__');
+flock($page_config_lock, LOCK_UN);
+fclose($page_config_lock);
+$cpu_sensors = detect_cpu_sensors();
+$aux_sensors = detect_aux_sensors();
 ?>
 
 <div class="fanctrl-header">
@@ -779,7 +783,7 @@ $(function() {
         if (pwm.label) {
           display += '（' + pwm.label + '）';
         }
-        select.append(`<option value="${pwm.sensor}">${display}</option>`);
+        select.append($('<option>').val(pwm.sensor).text(display));
       });
     }).fail(function(jqXHR, textStatus, errorThrown) {
       console.error('Failed to load PWM list into ' + selector, textStatus, errorThrown);
@@ -828,8 +832,8 @@ $(function() {
           if (pwm.label) display += `（${pwm.label}）`;
 
           // Apply the selected state.
-          const isSelected = (selectedPWM && pwm.sensor === selectedPWM) ? ' selected' : '';
-          select.append(`<option value="${pwm.sensor}"${isSelected}>${display}</option>`);
+          select.append($('<option>').val(pwm.sensor).text(display)
+            .prop('selected', Boolean(selectedPWM && pwm.sensor === selectedPWM)));
         });
 
         // Preserve selectedPWM when no matching option was discovered.
@@ -931,7 +935,8 @@ $(function() {
           const isSelected = pwm.sensor === selected;
           const isUsed = usedPWMs.includes(pwm.sensor) && !isSelected;
 
-          $(this).append(`<option value="${pwm.sensor}" ${isSelected ? 'selected' : ''} ${isUsed ? 'disabled' : ''}>${display}</option>`);
+          $(this).append($('<option>').val(pwm.sensor).text(display)
+            .prop({selected: isSelected, disabled: isUsed}));
         });
       });
 
@@ -1353,6 +1358,76 @@ $(function() {
       enabled: checked ? 1 : 0
     });
   }
+
+  const configBackupUrl = '/plugins/fanctrlplus2/include/FanctrlLogic.php';
+  function setConfigBackupBusy(busy) {
+    $('#fcp-config-export, #fcp-config-import').prop('disabled', busy);
+  }
+  function configBackupError(xhr) {
+    $('#fcp-config-backup-status').text(
+      xhr.responseJSON && xhr.responseJSON.message
+        ? xhr.responseJSON.message : 'The configuration request failed.'
+    );
+  }
+
+  $(document).on('click', '#fcp-config-export', function () {
+    setConfigBackupBusy(true);
+    $('#fcp-config-backup-status').text('Preparing backup…');
+    $.ajax({url: configBackupUrl, data: {op: 'exportconfig'}, dataType: 'json'})
+      .done(function (snapshot) {
+        const url = URL.createObjectURL(new Blob([JSON.stringify(snapshot, null, 2)], {type: 'application/json'}));
+        const link = document.createElement('a');
+        link.href = url;
+        link.download = 'fanctrlplus2-config-' + new Date().toISOString().replace(/[:.]/g, '-') + '.json';
+        document.body.appendChild(link);
+        link.click();
+        link.remove();
+        setTimeout(() => URL.revokeObjectURL(url), 0);
+        $('#fcp-config-backup-status').text('Backup downloaded. Only saved settings are included.');
+      }).fail(configBackupError).always(() => setConfigBackupBusy(false));
+  });
+
+  $(document).on('click', '#fcp-config-import', function () {
+    document.getElementById('fcp-config-import-file').click();
+  });
+
+  $(document).on('change', '#fcp-config-import-file', async function () {
+    const file = this.files[0];
+    this.value = '';
+    if (!file) return;
+    if (file.size > 2 * 1024 * 1024) {
+      $('#fcp-config-backup-status').text('The backup exceeds the 2 MiB limit.');
+      return;
+    }
+    const confirmation = await Swal.fire({
+      title: 'Restore saved configuration?',
+      text: 'This replaces saved fan settings, labels and ordering. Unsaved edits will be discarded. Custom sensor scripts stay unchanged, and the running or stopped state is preserved.',
+      icon: 'warning',
+      showCancelButton: true,
+      focusCancel: true,
+      confirmButtonText: 'Restore',
+      cancelButtonText: 'Cancel'
+    });
+    if (!confirmation.isConfirmed) return;
+    setConfigBackupBusy(true);
+    $('#fcp-config-backup-status').text('Restoring configuration…');
+    try {
+      const backup = await file.text();
+      JSON.parse(backup);
+      $.ajax({url: configBackupUrl, type: 'POST', data: {op: 'importconfig', backup: backup}, dataType: 'json'})
+        .done(function (response) {
+          if (response.status !== 'ok') {
+            $('#fcp-config-backup-status').text(response.message || 'Restore failed.');
+            return;
+          }
+          $('#fcp-config-backup-status').text('Configuration restored. Reloading…');
+          window.location.reload();
+        }).fail(configBackupError).always(() => setConfigBackupBusy(false));
+    } catch (error) {
+      $('#fcp-config-backup-status').text('The selected file is not a readable JSON backup.');
+      setConfigBackupBusy(false);
+    }
+  });
 
   $(document).on('click', '.add-disk-group-btn', function () {
     const $btn = $(this);
@@ -1720,7 +1795,7 @@ $(function() {
     <p><strong>Auxiliary Sensor Settings:</strong>  
         Works the same way as Disk and CPU Temperature Settings, for anything that is neither: chipset, VRM, network card, RAID controller, GPU.<br>
         <strong>Include Sensor(s)</strong> lists the non-CPU, non-NVMe hwmon sensors, and adds LSI/MegaRAID controllers (storcli), NVIDIA GPUs (nvidia-smi) and Mellanox network cards (mget_temp) when those tools are installed. The highest temperature among the selected sensors drives this fan.<br>
-        <strong>Custom sensors:</strong> anything else can be added as a script. Any executable placed in <code>/boot/config/plugins/fanctrlplus2/sensors.d/</code> becomes a selectable sensor named after the file. It must print the temperature in degrees Celsius and nothing else, and on any error print nothing and exit with a non-zero status. A script that errors, prints something else, or takes longer than 5&nbsp;seconds is skipped for that round of checks only, and tried again on the next one. Readings from every source, this one included, are clamped to 0–200&nbsp;°C, so a value outside that range drives the fan at the corresponding end of its curve instead of being discarded.
+        <strong>Custom sensors:</strong> add a readable script with a valid shebang to <code>/boot/config/plugins/fanctrlplus2/sensors.d/</code>. It becomes a selectable sensor named after the file. No executable bit is needed on the flash drive: the plugin runs a private executable copy on runtime storage using the script’s own interpreter. The script must print only a temperature in degrees Celsius, or exit non-zero on error. Errors, invalid output and scripts taking longer than 5&nbsp;seconds are skipped for that round only. Outputs outside the plausible −100–300&nbsp;°C range are skipped; valid negative readings are floored at 0&nbsp;°C.
     </p>
 
     <p><strong>Chart:</strong> Click the <strong>Chart</strong> button in a fan block to preview the fan speed curve based on your current settings.  
@@ -1963,6 +2038,18 @@ $(function() {
           While disabled, no fan-speed history is collected.
         </blockquote>
       </div>
+
+      <div class="fcp-section">
+        <p><strong>Configuration backup</strong></p>
+        <p>Download saved fan settings, PWM labels, dashboard switches and ordering.
+          Restoring replaces those settings. Custom sensor scripts are not included.</p>
+        <div class="fcp-actions">
+          <button type="button" class="btn" id="fcp-config-export">Export backup</button>
+          <button type="button" class="btn" id="fcp-config-import" aria-controls="fcp-config-import-file">Restore backup</button>
+          <input type="file" id="fcp-config-import-file" accept=".json,application/json" aria-label="Choose a configuration backup" hidden>
+        </div>
+        <p id="fcp-config-backup-status" role="status" aria-live="polite"></p>
+      </div>
     </div>
 
     <!-- Syslog settings. -->

src/usr/local/emhttp/plugins/fanctrlplus2/include/Common.php

@@ -447,9 +447,10 @@ function fcp_clamp_temp(int $temp): ?int {
 }
 
 // ===== User-supplied sensor scripts =====
-// Any executable dropped in the sensors.d directory is a sensor. The contract
-// is deliberately small: print the temperature in Celsius and nothing else, or
-// print nothing and exit non-zero, which disables it for that round only.
+// Any readable file dropped in the sensors.d directory is a sensor, executable
+// or not: the directory sits on flash that cannot hold an execute bit. The
+// contract is deliberately small: print the temperature in Celsius and nothing
+// else, or print nothing and exit non-zero, which disables it for that round only.
 const FCP_CUSTOM_SENSOR_DIR = '/boot/config/plugins/fanctrlplus2/sensors.d';
 const FCP_CUSTOM_SENSOR_TIMEOUT = 5;
 
@@ -469,16 +470,22 @@ function detect_custom_temps(string $dir = FCP_CUSTOM_SENSOR_DIR): array {
   $result = [];
   $scripts = glob("$dir/*") ?: [];
   sort($scripts);
+  $runner = dirname(__DIR__) . '/scripts/custom_sensor.sh';
 
   foreach ($scripts as $script) {
     $name = basename($script);
-    if (!is_file($script) || !is_executable($script)) continue;
-    if ($name[0] === '.') continue;
+    // Same names the control loop can read back: no hidden files, no
+    // characters that would not survive the sensor list.
+    if (!preg_match('/^[A-Za-z0-9_-][A-Za-z0-9._-]*$/', $name)) continue;
+    if (!is_file($script) || !is_readable($script)) continue;
 
+    // The flash drive holding the directory cannot carry an execute bit, so
+    // the runner executes a private runtime copy and enforces the timeout.
     $output = [];
     $status = 0;
     exec(
-      'timeout ' . FCP_CUSTOM_SENSOR_TIMEOUT . ' ' . escapeshellarg($script) . ' 2>/dev/null',
+      'bash ' . escapeshellarg($runner) . ' ' . escapeshellarg($script) . ' '
+        . FCP_CUSTOM_SENSOR_TIMEOUT . ' 2>/dev/null',
       $output,
       $status
     );