feat(nftables):add nftables support for nftables

ts/proxies/smart-proxy/route-connection-handler.ts

@@ -338,6 +338,22 @@ export class RouteConnectionHandler {
       );
     }
     
+    // Check if this route uses NFTables for forwarding
+    if (route.action.forwardingEngine === 'nftables') {
+      // For NFTables routes, we don't need to do anything at the application level
+      // The packet is forwarded at the kernel level
+      
+      // Log the connection
+      console.log(
+        `[${connectionId}] Connection forwarded by NFTables: ${record.remoteIP} -> port ${record.localPort}`
+      );
+      
+      // Just close the socket in our application since it's handled at kernel level
+      socket.end();
+      this.connectionManager.cleanupConnection(record, 'nftables_handled');
+      return;
+    }
+    
     // Handle the route based on its action type
     switch (route.action.type) {
       case 'forward':
@@ -368,6 +384,45 @@ export class RouteConnectionHandler {
     const connectionId = record.id;
     const action = route.action;
 
+    // Check if this route uses NFTables for forwarding
+    if (action.forwardingEngine === 'nftables') {
+      // Log detailed information about NFTables-handled connection
+      if (this.settings.enableDetailedLogging) {
+        console.log(
+          `[${record.id}] Connection forwarded by NFTables (kernel-level): ` +
+          `${record.remoteIP}:${socket.remotePort} -> ${socket.localAddress}:${record.localPort}` +
+          ` (Route: "${route.name || 'unnamed'}", Domain: ${record.lockedDomain || 'n/a'})`
+        );
+      } else {
+        console.log(
+          `[${record.id}] NFTables forwarding: ${record.remoteIP} -> port ${record.localPort} (Route: "${route.name || 'unnamed'}")`
+        );
+      }
+      
+      // Additional NFTables-specific logging if configured
+      if (action.nftables) {
+        const nftConfig = action.nftables;
+        if (this.settings.enableDetailedLogging) {
+          console.log(
+            `[${record.id}] NFTables config: ` +
+            `protocol=${nftConfig.protocol || 'tcp'}, ` +
+            `preserveSourceIP=${nftConfig.preserveSourceIP || false}, ` +
+            `priority=${nftConfig.priority || 'default'}, ` +
+            `maxRate=${nftConfig.maxRate || 'unlimited'}`
+          );
+        }
+      }
+      
+      // This connection is handled at the kernel level, no need to process at application level
+      // Close the socket gracefully in our application layer
+      socket.end();
+      
+      // Mark the connection as handled by NFTables for proper cleanup
+      record.nftablesHandled = true;
+      this.connectionManager.initiateCleanupOnce(record, 'nftables_handled');
+      return;
+    }
+
     // We should have a target configuration for forwarding
     if (!action.target) {
       console.log(`[${connectionId}] Forward action missing target configuration`);