From 720bf3549a217833de47caded51a9375670a8f29 Mon Sep 17 00:00:00 2001
From: anlicheng <244108715@qq.com>
Date: Thu, 16 Apr 2026 15:53:37 +0800
Subject: [PATCH] fix SDLIPV6AssistClient

---
 Tun/Punchnet/SDLIPV6AssistClient.swift | 148 +++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 Tun/Punchnet/SDLIPV6AssistClient.swift

diff --git a/Tun/Punchnet/SDLIPV6AssistClient.swift b/Tun/Punchnet/SDLIPV6AssistClient.swift
new file mode 100644
index 0000000..345feaa
--- /dev/null
+++ b/Tun/Punchnet/SDLIPV6AssistClient.swift
@@ -0,0 +1,148 @@
+//
+//  SDLDNSClient 2.swift
+//  punchnet
+//
+//  Created by 安礼成 on 2026/4/9.
+//
+import Foundation
+import Network
+
+actor SDLIPV6AssistClient {
+    private enum State {
+        case idle
+        case running
+        case stopped
+    }
+    
+    private var state: State = .idle
+    private var connection: NWConnection?
+    private var receiveTask: Task<Void, Never>?
+    private let assistServerAddress: NWEndpoint
+    
+    init(host: String, port: UInt16 ) {
+        self.assistServerAddress = .hostPort(host: NWEndpoint.Host(host), port: NWEndpoint.Port(integerLiteral: port))
+    }
+    
+    func start() {
+        guard case .idle = self.state else {
+            return
+        }
+        
+        self.state = .running
+        
+        // 1. 配置参数：这是解决环路的关键
+        let parameters = NWParameters.udp
+        
+        // 禁止此连接走 TUN 网卡（在 NE 中 TUN 通常被归类为 .other）
+        parameters.prohibitedInterfaceTypes = [.other]
+        // 2. 增强健壮性：启用多路径切换（替代 pathSelectionOptions 的意图）
+        parameters.multipathServiceType = .handover
+        
+        // 2. 创建连接
+        let connection = NWConnection(to: self.assistServerAddress, using: parameters)
+        self.connection = connection
+        
+        connection.stateUpdateHandler = { [weak self] state in
+            Task {
+                await self?.handleConnectionStateUpdate(state, for: connection)
+            }
+        }
+        
+        // 启动连接队列
+        connection.start(queue: .global())
+    }
+    
+    /// 接收数据的递归循环
+    private static func makeReceiveStream(for connection: NWConnection) -> AsyncStream<Data> {
+        return AsyncStream(bufferingPolicy: .bufferingNewest(256)) { continuation in
+            func receiveNext() {
+                connection.receiveMessage { content, _, _, error in
+                    if let data = content, !data.isEmpty {
+                        // 将收到的 DNS 响应写回 AsyncStream
+                        continuation.yield(data)
+                    }
+                    
+                    if error == nil && connection.state == .ready {
+                        receiveNext() // 继续监听下一个包
+                    } else {
+                        continuation.finish()
+                    }
+                }
+            }
+            
+            receiveNext()
+        }
+    }
+    
+    /// 发送 DNS 查询包（由 TUN 拦截到的原始 IP 包数据）
+    func forward(ipPacketData: Data) {
+        guard case .running = self.state, let connection = self.connection, connection.state == .ready else {
+            return
+        }
+        
+        connection.send(content: ipPacketData, completion: .contentProcessed { error in
+            if let error = error {
+                SDLLogger.log("[SDLIPV6AssistClient] Send error: \(error)", for: .debug)
+            }
+        })
+    }
+    
+    func stop() {
+        guard self.state != .stopped else {
+            return
+        }
+        
+        self.state = .stopped
+        self.receiveTask?.cancel()
+        self.receiveTask = nil
+        self.connection?.cancel()
+        self.connection = nil
+    }
+    
+    private func handleConnectionStateUpdate(_ state: NWConnection.State, for connection: NWConnection) {
+        guard case .running = self.state else {
+            return
+        }
+        
+        switch state {
+        case .ready:
+            SDLLogger.log("[SDLIPV6AssistClient] Connection ready", for: .debug)
+            self.startReceiveTask(for: connection)
+        case .failed(let error):
+            SDLLogger.log("[SDLIPV6AssistClient] Connection failed: \(error)", for: .debug)
+            self.stop()
+        case .cancelled:
+            self.stop()
+        default:
+            break
+        }
+    }
+    
+    private func startReceiveTask(for connection: NWConnection) {
+        guard self.receiveTask == nil else {
+            return
+        }
+        
+        let stream = Self.makeReceiveStream(for: connection)
+        self.receiveTask = Task { [weak self] in
+            for await data in stream {
+                guard let self else {
+                    break
+                }
+                await self.handleReceivedPacket(data)
+            }
+        }
+    }
+    
+    private func handleReceivedPacket(_ data: Data) {
+        guard case .running = self.state else {
+            return
+        }
+        
+        NSLog("data: \(data)")
+    }
+    
+    deinit {
+        self.connection?.cancel()
+    }
+}