fix dns

Tun/DNS/DNSCloudClient.swift

@@ -16,33 +16,36 @@ actor DNSCloudClient {
         case invalidData
     }
     
-    private enum State {
-        case idle
-        case starting
-        case running
-        case stopped
-    }
-    
-    private var state: State = .idle
     private let queue = DispatchQueue(label: "com.sdl.DNSCloudClient.queue")
-    
+    private let connection: NWConnection
-    private var connection: NWConnection?
-    private let dnsServerAddress: NWEndpoint
     
     // 用于对外输出收到的 DNS 响应包
     nonisolated let packetFlow: AsyncThrowingStream<Data, Error>
     private let packetContinuation: AsyncThrowingStream<Data, Error>.Continuation
-    private var isPacketContinuationFinished: Bool = false
+    
     private let readySignal = AsyncOneShot<Void>()
     
+    private var isStopped: Bool = false
+    private var isPacketContinuationFinished: Bool = false
+    
     /// - Parameter serverIP: 你的 sn-server IP 地址 (如 "8.8.8.8")
     /// - Parameter port: 端口 (如 53)
     init(serverIP: String, port: UInt16) {
-        self.dnsServerAddress = .hostPort(host: Self.makeEndpointHost(address: serverIP), port: NWEndpoint.Port(integerLiteral: port))
+        let dnsServerAddress = NWEndpoint.hostPort(host: Self.makeEndpointHost(address: serverIP), port: NWEndpoint.Port(integerLiteral: port))
         
         let packetPair = AsyncThrowingStream.makeStream(of: Data.self)
         self.packetFlow = packetPair.stream
         self.packetContinuation = packetPair.continuation
+        
+        // 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
+        self.connection = NWConnection(to: dnsServerAddress, using: parameters)
     }
 
     private static func makeEndpointHost(address ip: String) -> NWEndpoint.Host {
@@ -58,46 +61,29 @@ actor DNSCloudClient {
     }
     
     func run() async throws {
-        guard self.state == .idle else {
+        self.connection.stateUpdateHandler = { [weak self] state in
-            return
-        }
-        self.state = .starting
-
-        // 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.dnsServerAddress, using: parameters)
-        connection.stateUpdateHandler = { [weak self] state in
             Task {
-                await self?.handleConnectionStateUpdate(state, for: connection)
+                await self?.handleConnectionStateUpdate(state)
             }
         }
-        self.connection = connection
+        self.connection.start(queue: self.queue)
-
-        // 启动连接队列
-        connection.start(queue: self.queue)
         
         try await withTaskCancellationHandler {
             try await self.readySignal.wait()
+
             while true {
                 try Task.checkCancellation()
                 let data = try await self.readOnce()
                 self.packetContinuation.yield(data)
             }
         } onCancel: {
-            connection.cancel()
+            self.connection.cancel()
         }
     }
     
     /// 发送 DNS 查询包（由 TUN 拦截到的原始 IP 包数据）
     func forward(ipPacketData: Data) {
-        guard self.state == .running,
+        guard connection.state == .ready else {
-              let connection = self.connection, connection.state == .ready else {
             return
         }
         
@@ -111,30 +97,25 @@ actor DNSCloudClient {
     }
     
     func stop() async {
-        guard self.state != .stopped else {
+        guard !self.isStopped else {
             return
         }
+        self.isStopped = true
         
-        self.state = .stopped
+        self.connection.cancel()
-        
-        let connection = self.connection
-        self.connection = nil
-        
-        connection?.cancel()
         await self.readySignal.fail(DNSCloudError.cancelled)
         self.finishPacketContinuationIfNeed(throwing: nil)
         
         SDLLogger.log("[SDLCloudClient] stopped")
     }
     
-    private func handleConnectionStateUpdate(_ state: NWConnection.State, for connection: NWConnection) async {
+    private func handleConnectionStateUpdate(_ state: NWConnection.State) async {
         switch state {
         case .ready:
-            guard self.state != .stopped, self.isCurrentConnection(connection) else {
+            guard !self.isStopped else {
                 return
             }
 
-            self.state = .running
             SDLLogger.log("[DNSClient] Connection ready", for: .debug)
             await self.readySignal.succeed(())
         case .failed(let error):
@@ -148,20 +129,13 @@ actor DNSCloudClient {
         }
     }
 
-    private func isCurrentConnection(_ connection: NWConnection) -> Bool {
-        guard let currentConnection = self.connection else {
-            return false
-        }
-
-        return currentConnection === connection
-    }
-    
     private func finishPacketContinuationIfNeed(throwing error: DNSCloudError?) {
         guard !self.isPacketContinuationFinished else {
             return
         }
 
         self.isPacketContinuationFinished = true
+
         if let error {
             self.packetContinuation.finish(throwing: error)
         } else {
@@ -170,21 +144,27 @@ actor DNSCloudClient {
     }
     
     private func readOnce() async throws -> Data {
-        guard let connection = self.connection, connection.state == .ready else {
+        guard self.connection.state == .ready else {
             throw DNSCloudError.cancelled
         }
         
-        return try await withCheckedThrowingContinuation { continuation in
+        let readContinuation = OnceContinuation<Data, Error>()
-            connection.receiveMessage { content, _, _, error in
+        return try await withTaskCancellationHandler {
+            try await withCheckedThrowingContinuation { cont in
+                readContinuation.set(cont)
+                self.connection.receiveMessage { content, _, _, error in
                     if let error {
-                    continuation.resume(throwing: error)
+                        readContinuation.resume(throwing: error)
                     } else if let data = content, !data.isEmpty {
-                    continuation.resume(returning: data)
+                        readContinuation.resume(returning: data)
                     } else {
-                    continuation.resume(throwing: DNSCloudError.invalidData)
+                        readContinuation.resume(throwing: DNSCloudError.invalidData)
                     }
                 }
             }
+        } onCancel: {
+            readContinuation.resume(throwing: CancellationError())
+        }
     }
     
     deinit {

Tun/DNS/DNSCloudService.swift

@@ -20,35 +20,11 @@ actor DNSCloudService {
         let client = DNSCloudClient(serverIP: self.serverIP, port: 15353)
         self.currentClient = client
 
+        defer {
+            self.clearCurrent(client, generation: generation)
+        }
+
         do {
-            try await self.run(client: client)
-            self.clearCurrent(client, generation: generation)
-            await client.stop()
-        } catch is CancellationError {
-            self.clearCurrent(client, generation: generation)
-            await client.stop()
-            throw CancellationError()
-        } catch {
-            self.clearCurrent(client, generation: generation)
-            await client.stop()
-            throw error
-        }
-    }
-
-    func stop() async {
-        self.generation &+= 1
-
-        let client = self.currentClient
-        self.currentClient = nil
-
-        await client?.stop()
-    }
-
-    func forward(ipPacketData: Data) async {
-        await self.currentClient?.forward(ipPacketData: ipPacketData)
-    }
-
-    private func run(client: DNSCloudClient) async throws {
             let onEvent = self.onEvent
 
             try await withThrowingTaskGroup(of: Void.self) { group in
@@ -69,6 +45,28 @@ actor DNSCloudService {
 
                 _ = try await group.next()
             }
+
+            await client.stop()
+        } catch is CancellationError {
+            await client.stop()
+            throw CancellationError()
+        } catch {
+            await client.stop()
+            throw error
+        }
+    }
+
+    func stop() async {
+        self.generation &+= 1
+
+        let client = self.currentClient
+        self.currentClient = nil
+
+        await client?.stop()
+    }
+
+    func forward(ipPacketData: Data) async {
+        await self.currentClient?.forward(ipPacketData: ipPacketData)
     }
 
     private func nextGeneration() -> UInt64 {