Admonstrator · Copilot · Oct 26, 2025 · Oct 26, 2025 · Oct 26, 2025 · Oct 26, 2025
diff --git a/readme.md b/readme.md
@@ -73,6 +73,7 @@ The `update-tailscale.sh` script supports the following arguments:
 | `--no-download`       | Skips downloading binaries. Use pre-downloaded archive at `/tmp/tailscale.tar.gz`.                                               |
 | `--no-tiny`           | Uses full Tailscale binaries instead of tiny version. Not recommended for GL.iNet routers.                                       |
 | `--select-release`    | Displays available releases and lets you choose a specific version. ⚠️ Downgrading not officially supported!                      |
+| `--background`        | Runs script in background mode, survives SSH disconnection. Logs to `/tmp/tailscale-update.log`. Recommended when using `--ssh`! |
 | `--testing`           | Uses prerelease/testing versions from the testing branch. ⚠️ **Use at your own risk!** May contain bugs or experimental features. |
 | `--ssh`               | Enables Tailscale SSH feature after installation.                                                                                |
 | `--log`               | Shows timestamps in all log messages. Useful for debugging and tracking execution time.                                          |
@@ -83,6 +84,27 @@ The `update-tailscale.sh` script supports the following arguments:
 
 ## 📚 Usage Examples
 
+### Background Mode (Recommended for SSH over Tailscale)
+
+Run the script in background mode to prevent interruption when Tailscale restarts:
+
+```bash
+wget -O update-tailscale.sh https://raw.githubusercontent.com/Admonstrator/glinet-tailscale-updater/main/update-tailscale.sh && sh update-tailscale.sh --background --force
+```
+
+This is especially useful when:
+- Connected via Tailscale SSH (prevents session termination)
+- Running over an unstable connection
+- Enabling Tailscale SSH with `--ssh` flag
+
+Monitor the background execution:
+
+```bash
+tail -f /tmp/tailscale-update.log
+```
+
+> **💡 Tip:** The script automatically saves your preferences and continues running even if SSH disconnects!
+
 ### Testing/Prerelease Versions
 
 Install prerelease versions from the testing branch for early access to new features:
@@ -164,7 +186,15 @@ The script automatically adds `--stateful-filtering=false` to the `gl_tailscale`
 
 If you agree to enable Tailscale SSH during installation (manually or by using `--ssh`), the script will automatically configure Tailscale SSH after updating. You can read more about Tailscale SSH [here](https://tailscale.com/kb/1193/tailscale-ssh).
 
-**⚠️ Warning:** If you are connected to your router via Tailscale SSH, you will be disconnected when SSH support is enabled. This might cause the script to terminate prematurely. It is recommended to run the script via local SSH or via GoodCloud SSH terminal.
+**⚠️ Warning:** If you are connected to your router via Tailscale SSH, you will be disconnected when SSH support is enabled. This might cause the script to terminate prematurely.
+
+**💡 Solution:** Use the `--background` flag to run the script in background mode, which will continue execution even if your SSH session disconnects:
+
+```bash
+sh update-tailscale.sh --background --ssh --force
+```
+
+Alternatively, run the script via local SSH or via GoodCloud SSH terminal.
 
 ### 📦 Tiny-Tailscale
 

diff --git a/update-tailscale.sh b/update-tailscale.sh
@@ -25,13 +25,125 @@ SHOW_LOG=0
 ASCII_MODE=0
 TESTING=0
 ENABLE_SSH=0
+BACKGROUND_MODE=0
+WRAPPED_EXECUTION=0
 USER_WANTS_UPX=""
 USER_WANTS_SSH=""
 USER_WANTS_PERSISTENCE=""
 RED='\033[0;31m'
 GREEN='\033[0;32m'
 YELLOW='\033[0;33m'
 INFO='\033[0m' # No Color
+ENV_FILE="/tmp/tailscale-update.env"
+LOG_FILE="/tmp/tailscale-update.log"
+WRAPPER_SCRIPT="/tmp/update-tailscale-wrapper.sh"
+
+# Wrapper Functions
+save_environment() {
+    log "INFO" "Saving execution environment to $ENV_FILE"
+    cat > "$ENV_FILE" << EOF
+# Tailscale Update Environment
+# Generated: $(date)
+IGNORE_FREE_SPACE=$IGNORE_FREE_SPACE
+FORCE=$FORCE
+FORCE_UPGRADE=$FORCE_UPGRADE
+RESTORE=$RESTORE
+NO_UPX=$NO_UPX
+NO_DOWNLOAD=$NO_DOWNLOAD
+NO_TINY=$NO_TINY
+SELECT_RELEASE=$SELECT_RELEASE
+SHOW_LOG=$SHOW_LOG
+ASCII_MODE=$ASCII_MODE
+TESTING=$TESTING
+ENABLE_SSH=$ENABLE_SSH
+BACKGROUND_MODE=$BACKGROUND_MODE
+WRAPPED_EXECUTION=1
+USER_WANTS_UPX="$USER_WANTS_UPX"
+USER_WANTS_SSH="$USER_WANTS_SSH"
+USER_WANTS_PERSISTENCE="$USER_WANTS_PERSISTENCE"
+EOF
+    log "SUCCESS" "Environment saved successfully"
+}
+
+load_environment() {
+    if [ -f "$ENV_FILE" ]; then
+        log "INFO" "Loading saved environment from $ENV_FILE"
+        # shellcheck source=/dev/null
+        . "$ENV_FILE"
+        log "SUCCESS" "Environment loaded successfully"
+        return 0
+    else
+        log "WARNING" "No saved environment found at $ENV_FILE"
+        return 1
+    fi
+}
+
+invoke_wrapper() {
+    log "INFO" "Starting background execution wrapper"
+
+    # Get the current script path (portable method for OpenWrt/BusyBox)
+    if command -v readlink >/dev/null 2>&1 && readlink -f "$0" >/dev/null 2>&1; then
+        SCRIPT_PATH=$(readlink -f "$0")
+    else
+        # Fallback for systems without readlink -f (e.g., some BusyBox versions)
+        SCRIPT_PATH="$(cd "$(dirname "$0")" && pwd)/$(basename "$0")"
+    fi
+
+    # Copy script to temp location
+    log "INFO" "Copying script to $WRAPPER_SCRIPT"
+    cp "$SCRIPT_PATH" "$WRAPPER_SCRIPT"
+    chmod +x "$WRAPPER_SCRIPT"
+
+    # Save all current flags and user responses
+    save_environment
+
+    # Create a wrapper invocation message
+    echo "============================================================"
+    echo ""
+    echo "  Background Execution Mode"
+    echo ""
+    echo "============================================================"
+    echo ""
+    echo "  The script will now run in the background to prevent"
+    echo "  interruption if your SSH session disconnects."
+    echo ""
+    echo "  You can monitor progress by checking:"
+    echo "    tail -f $LOG_FILE"
+    echo ""
+    echo "  The script will continue running even if you disconnect."
+    echo ""
+    echo "============================================================"
+    echo ""
+
+    # Start the wrapped script in background with nohup
+    log "INFO" "Starting background execution..."
+
+    # Launch the wrapped script with appropriate method
+    if command -v nohup >/dev/null 2>&1; then
+        nohup "$WRAPPER_SCRIPT" --wrapped >> "$LOG_FILE" 2>&1 &
+        WRAPPER_PID=$!
+        log "SUCCESS" "Background process started with PID: $WRAPPER_PID (using nohup)"
+    elif command -v setsid >/dev/null 2>&1; then
+        setsid "$WRAPPER_SCRIPT" --wrapped >> "$LOG_FILE" 2>&1 &
+        WRAPPER_PID=$!
+        log "SUCCESS" "Background process started with PID: $WRAPPER_PID (using setsid)"
+    else
+        # Fallback to simple background execution
+        "$WRAPPER_SCRIPT" --wrapped >> "$LOG_FILE" 2>&1 &
+        WRAPPER_PID=$!
+        log "WARNING" "Started without nohup/setsid (PID: $WRAPPER_PID)"
+    fi
+
+    echo ""
+    echo "To view the log in real-time, run:"
+    echo "  tail -f $LOG_FILE"
+    echo ""
+    echo "The script is now running in the background."
+    echo "You can safely disconnect from SSH."
+    echo ""
+
+    exit 0
+}
 
 # Functions
 invoke_intro() {
@@ -58,6 +170,12 @@ invoke_intro() {
     }
 
 collect_user_preferences() {
+    # If running in wrapped mode, load from saved environment
+    if [ "$WRAPPED_EXECUTION" -eq 1 ]; then
+        log "INFO" "Running in wrapped execution mode - using saved preferences"
+        return 0
+    fi
+
     log "INFO" "Collecting user preferences before starting the update process"
     echo ""
 
@@ -564,6 +682,38 @@ invoke_outro() {
         tailscale set --ssh --accept-risk=lose-ssh
         log "SUCCESS" "Tailscale SSH support enabled."
     fi
+
+    # Clean up wrapper files if running in wrapped mode
+    if [ "$WRAPPED_EXECUTION" -eq 1 ]; then
+        log "INFO" "Cleaning up wrapper files"
+        # Validate paths before deletion to ensure they're in /tmp
+        # Using case pattern matching for robust path validation
+        case "$ENV_FILE" in
+            /tmp/*)
+                if [ -f "$ENV_FILE" ]; then
+                    rm -f "$ENV_FILE"
+                    log "SUCCESS" "Removed environment file: $ENV_FILE"
+                fi
+                ;;
+            *)
+                log "WARNING" "Skipping cleanup of ENV_FILE - path outside /tmp: $ENV_FILE"
+                ;;
+        esac
+
+        case "$WRAPPER_SCRIPT" in
+            /tmp/*)
+                if [ -f "$WRAPPER_SCRIPT" ]; then
+                    rm -f "$WRAPPER_SCRIPT"
+                    log "SUCCESS" "Removed wrapper script: $WRAPPER_SCRIPT"
+                fi
+                ;;
+            *)
+                log "WARNING" "Skipping cleanup of WRAPPER_SCRIPT - path outside /tmp: $WRAPPER_SCRIPT"
+                ;;
+        esac
+
+        log "SUCCESS" "Wrapper cleanup complete"
+    fi
 }
 
 invoke_help() {
@@ -578,13 +728,20 @@ invoke_help() {
     printf "  \033[93m--no-tiny\033[0m            \033[97mDo not use the tiny version of tailscale\033[0m\n"
     printf "  \033[93m--select-release\033[0m     \033[97mSelect a specific release version\033[0m\n"
     printf "  \033[93m--ssh\033[0m                \033[97mEnable Tailscale SSH support automatically\033[0m\n"
+    printf "  \033[93m--background\033[0m         \033[97mRun in background mode (survives SSH disconnection)\033[0m\n"
     printf "  \033[93m--testing\033[0m            \033[97mUse testing/prerelease versions from testing branch\033[0m\n"
     printf "  \033[93m--log\033[0m                \033[97mShow timestamps in log messages\033[0m\n"
     printf "  \033[93m--ascii\033[0m              \033[97mUse ASCII characters instead of emojis\033[0m\n"
     printf "  \033[93m--help\033[0m               \033[97mShow this help\033[0m\n"
 }
 
 invoke_update() {
+    # Skip update check if running in wrapped mode
+    if [ "$WRAPPED_EXECUTION" -eq 1 ]; then
+        log "INFO" "Running in wrapped mode - skipping update check"
+        return 0
+    fi
+
     log "INFO" "Checking for script updates"
     local update_url="$UPDATE_URL"
     if [ "$TESTING" -eq 1 ]; then
@@ -826,6 +983,12 @@ for arg in "$@"; do
     --ssh)
         ENABLE_SSH=1
         ;;
+    --background)
+        BACKGROUND_MODE=1
+        ;;
+    --wrapped)
+        WRAPPED_EXECUTION=1
+        ;;
     *)
         echo "Unknown argument: $arg"
         invoke_help
@@ -835,6 +998,17 @@ for arg in "$@"; do
 done
 
 # Main
+# Check if running in wrapped mode - if so, load environment
+if [ "$WRAPPED_EXECUTION" -eq 1 ]; then
+    load_environment
+fi
+
+# Check if background mode is requested and not already wrapped
+if [ "$BACKGROUND_MODE" -eq 1 ] && [ "$WRAPPED_EXECUTION" -eq 0 ]; then
+    invoke_wrapper
+    # invoke_wrapper will exit, so we never reach here
+fi
+
 # Check if --restore flag is used, if yes, restore tailscale
 if [ "$RESTORE" -eq 1 ]; then
     restore