fix dnsClient

Tun/Punchnet/Actors/SDLContextActor.swift

@@ -341,49 +341,23 @@ actor SDLContextActor {
         SDLLogger.log("[SDLContext] dnsLocalClient started")
         self.dnsLocalClient = dnsLocalClient
         
-        try await withThrowingTaskGroup { group in
         defer {
-                group.cancelAll()
+            self.dnsLocalClient = nil
+            //dnsLocalClient.stop()
         }
         
-            group.addTask {
+        try await withTaskCancellationHandler {
             // 处理事件流
-                for await packet in dnsLocalClient.packetFlow {
+            for try await packet in dnsLocalClient.packetFlow {
                 try Task.checkCancellation()
-                    
                 // 要想办法构造一个完整的Ip包
                 let nePacket = NEPacket(data: packet, protocolFamily: 2)
                 self.provider.packetFlow.writePacketObjects([nePacket])
             }
             throw SDLContextError.dnsLocalClientClosed
-            }
+        } onCancel: {
-            
+            Task {
-            group.addTask {
-                for await event in dnsLocalClient.eventStream {
-                    try Task.checkCancellation()
-                    
-                    switch event {
-                    case .failed(let error):
-                        SDLLogger.log("[SDLContext] dnsLocalClient failed: \(error)")
-                        throw error
-                    case .cancelled:
-                        SDLLogger.log("[SDLContext] dnsLocalClient cancelled")
-                        throw SDLContextError.dnsLocalClientCancelled
-                    case .sendFailed(let error):
-                        SDLLogger.log("[SDLContext] dnsLocalClient sendFailed: \(error)")
-                        throw error
-                    }
-                }
-            }
-            
-            do {
-                try await group.next()
                 await dnsLocalClient.stop()
-                self.dnsLocalClient = nil
-            } catch let err {
-                await dnsLocalClient.stop()
-                self.dnsLocalClient = nil
-                throw err
             }
         }
     }

Tun/Punchnet/DNS/DNSLocalClient.swift

@@ -16,11 +16,12 @@ actor DNSLocalClient {
     
     private enum State {
         case idle
+        case starting
         case running
         case stopped
     }
     
-    enum Event {
+    enum DNSLocalError: Error {
         case failed(Error)
         case cancelled
         case sendFailed(Error)
@@ -35,16 +36,10 @@ actor DNSLocalClient {
     private var cleanupTask: Task<Void, Never>?
     private let timeoutInterval: TimeInterval = 3.0
     
-    
+    nonisolated let packetFlow: AsyncThrowingStream<Data, Error>
-    
-    public let packetFlow: AsyncStream<Data>
     @ObservationIgnored
-    private let packetContinuation: AsyncStream<Data>.Continuation
+    private let packetContinuation: AsyncThrowingStream<Data, Error>.Continuation
-    
+    private var isPacketContinuationFinished: Bool = false
-    // 事件处理
-    public let eventStream: AsyncStream<Event>
-    @ObservationIgnored
-    private let eventContinuation: AsyncStream<Event>.Continuation
     
     private var pendingRequests: [UInt16: PendingRequest] = [:]
     private var nextTransactionID: UInt16 = 1
@@ -52,16 +47,21 @@ actor DNSLocalClient {
     init(host: String) {
         self.dnsServerEndpoint = .hostPort(host: NWEndpoint.Host(host), port: 53)
         
-        let (stream, continuation) = AsyncStream.makeStream(of: Data.self, bufferingPolicy: .bufferingNewest(256))
+        let (stream, continuation) = AsyncThrowingStream.makeStream(of: Data.self, bufferingPolicy: .bufferingNewest(256))
         self.packetFlow = stream
         self.packetContinuation = continuation
         
-        let eventPair = AsyncStream.makeStream(of: Event.self)
+        self.packetContinuation.onTermination = { termination in
-        self.eventStream = eventPair.stream
+            SDLLogger.log("[DNSLocalClient] packetFlow terminated: \(termination)")
-        self.eventContinuation = eventPair.continuation
+        }
     }
     
     func start() {
+        guard self.state == .idle else {
+            return
+        }
+        self.state = .starting
+
         let parameters = NWParameters.udp
         parameters.prohibitedInterfaceTypes = [.other]
         // 2. 增强健壮性：启用多路径切换（替代 pathSelectionOptions 的意图）
@@ -73,44 +73,47 @@ actor DNSLocalClient {
                 await self?.handleConnectionStateUpdate(state, for: connection)
             }
         }
-        connection.start(queue: .global())
-        self.connection = connection
 
-        self.cleanupTask = Task { [weak self] in
+        let cleanupTask = Task { [weak self] in
             while !Task.isCancelled {
                 try? await Task.sleep(nanoseconds: 3 * 1_000_000_000)
                 await self?.performCleanup()
             }
         }
+
+        self.connection = connection
+        self.cleanupTask = cleanupTask
+        connection.start(queue: .global())
     }
     
     func query(tracker: DNSTracker, dnsPayload: Data) {
-        guard let connection = self.connection, connection.state == .ready, dnsPayload.count >= 2 else {
+        let transactionID: UInt16
+        let connection: NWConnection
+        let rewrittenPayload: Data
+
+        guard self.state != .stopped,
+              let connection = self.connection, connection.state == .ready, dnsPayload.count >= 2 else {
             return
         }
         
-        guard let transactionID = self.allocateTransactionID() else {
+        guard let allocatedTransactionID = self.allocateTransactionID() else {
             SDLLogger.log("[DNSLocalClient] no available transaction id", for: .debug)
             return
         }
         
+        transactionID = allocatedTransactionID
         self.pendingRequests[transactionID] = PendingRequest(tracker: tracker)
-        let rewrittenPayload = Self.rewriteTransactionID(in: dnsPayload, to: transactionID)
+        rewrittenPayload = Self.rewriteTransactionID(in: dnsPayload, to: transactionID)
         
-        connection.send(content: rewrittenPayload, completion: .contentProcessed { error in
+        connection.send(content: rewrittenPayload, completion: .contentProcessed { [weak self] error in
             if let error {
-                self.eventContinuation.yield(.sendFailed(error))
                 Task {
-                    await self.removePendingRequest(forKey: transactionID)
+                    await self?.handleSendFailure(transactionID: transactionID, error: error)
                 }
             }
         })
     }
     
-    private func removePendingRequest(forKey id: UInt16) {
-        self.pendingRequests.removeValue(forKey: id)
-    }
-    
     func stop() {
         guard self.state != .stopped else {
             return
@@ -118,31 +121,35 @@ actor DNSLocalClient {
         
         self.state = .stopped
         
-        self.receiveTask?.cancel()
+        let receiveTask = self.receiveTask
         self.receiveTask = nil
         
-        self.connection?.cancel()
+        let connection = self.connection
         self.connection = nil
         
-        self.cleanupTask?.cancel()
+        let cleanupTask = self.cleanupTask
         self.cleanupTask = nil
         
         self.pendingRequests.removeAll()
         self.nextTransactionID = 1
 
-        self.packetContinuation.finish()
+        receiveTask?.cancel()
+        connection?.cancel()
+        cleanupTask?.cancel()
+        self.finishPacketContinuationIfNeed(throwing: nil)
     }
     
     private func handleConnectionStateUpdate(_ state: NWConnection.State, for conn: NWConnection) {
         switch state {
         case .ready:
+            if self.markConnectionReady(conn) {
                 self.startReceiveTask(for: conn)
-            self.state = .running
+            }
         case .failed(let error):
             SDLLogger.log("[DNSLocalClient] failed with error: \(error.localizedDescription)", for: .debug)
-            self.eventContinuation.yield(.failed(error))
+            self.finishPacketContinuationIfNeed(throwing: .failed(error))
         case .cancelled:
-            self.eventContinuation.yield(.cancelled)
+            self.finishPacketContinuationIfNeed(throwing: .cancelled)
         default:
             ()
         }
@@ -151,7 +158,7 @@ actor DNSLocalClient {
     private func startReceiveTask(for conn: NWConnection) {
         let stream = Self.makeReceiveStream(for: conn)
         
-        self.receiveTask = Task { [weak self] in
+        let task = Task { [weak self] in
             for await data in stream {
                 guard let self else {
                     break
@@ -159,6 +166,30 @@ actor DNSLocalClient {
                 await self.handleResponse(data: data)
             }
         }
+
+        let shouldKeepTask = self.state != .stopped && self.isCurrentConnection(conn)
+        if shouldKeepTask {
+            self.receiveTask?.cancel()
+            self.receiveTask = task
+        }
+
+        if !shouldKeepTask {
+            task.cancel()
+        }
+    }
+    
+    private func finishPacketContinuationIfNeed(throwing error: DNSLocalError?) {
+        guard !self.isPacketContinuationFinished else {
+            return
+        }
+        
+        self.isPacketContinuationFinished = true
+
+        if let error {
+            self.packetContinuation.finish(throwing: error)
+        } else {
+            self.packetContinuation.finish()
+        }
     }
     
     private func handleResponse(data: Data) {
@@ -179,6 +210,28 @@ actor DNSLocalClient {
         self.packetContinuation.yield(packet)
     }
 
+    private func markConnectionReady(_ conn: NWConnection) -> Bool {
+        guard self.state != .stopped, self.isCurrentConnection(conn) else {
+            return false
+        }
+
+        self.state = .running
+        return true
+    }
+
+    private func isCurrentConnection(_ conn: NWConnection) -> Bool {
+        guard let currentConnection = self.connection else {
+            return false
+        }
+
+        return currentConnection === conn
+    }
+
+    private func handleSendFailure(transactionID: UInt16, error: NWError) {
+        self.pendingRequests.removeValue(forKey: transactionID)
+        self.finishPacketContinuationIfNeed(throwing: .sendFailed(error))
+    }
+    
     private func performCleanup() {
         let now = Date()
         self.pendingRequests = self.pendingRequests.filter { _, request in