fix dnsLocalClient

Tun/Punchnet/Actors/SDLContextActor.swift

@@ -58,8 +58,8 @@ actor SDLContextActor {
     private var dnsClient: DNSCloudClient?
     
     // Localdns的client对象
+    private let publicDnsServers = ["223.5.5.5", "119.29.29.29"]
     private var dnsLocalClient: DNSLocalClient?
-    private var dnsLocalWorker: Task<Void, Never>?
 
     private var quicClient: SDLQUICClient?
     
@@ -351,28 +351,58 @@ actor SDLContextActor {
         
     }
     
-    private func startDnsLocalClient() async {
+    private func startDnsLocalClient() async throws {
-        self.dnsLocalWorker?.cancel()
+        let dnsServer = self.publicDnsServers.randomElement() ?? self.publicDnsServers[0]
-        self.dnsLocalWorker = nil
-        
         // 启动dns服务
-        let dnsLocalClient = DNSLocalClient()
+        let dnsLocalClient = DNSLocalClient(host: dnsServer)
         await dnsLocalClient.start()
-        SDLLogger.log("[SDLContext] dnsClient started")
+        SDLLogger.log("[SDLContext] dnsLocalClient started")
         self.dnsLocalClient = dnsLocalClient
-        let packetFlow = dnsLocalClient.packetFlow
+        
-        self.dnsLocalWorker = Task.detached {
+        try await withThrowingTaskGroup { group in
-            // 处理事件流
+            defer {
-            for await packet in packetFlow {
+                group.cancelAll()
-                if Task.isCancelled {
-                    break
             }
             
+            group.addTask {
+                // 处理事件流
+                for 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])
                 }
             }
+            
+            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")
+                        return
+                    case .sendFailed(let error):
+                        SDLLogger.log("[SDLContext] dnsLocalClient sendFailed: \(error)")
+                        throw error
+                    }
+                }
+            }
+            
+            do {
+                try await group.next()
+                await self.dnsLocalClient?.stop()
+                self.dnsLocalClient = nil
+            } catch let err {
+                await self.dnsLocalClient?.stop()
+                self.dnsLocalClient = nil
+                throw err
+            }
+        }
     }
     
     private func startUDPHole() async throws {
@@ -498,11 +528,6 @@ actor SDLContextActor {
 
     // 处理context的停止问题
     public func stop() async {
-        await self.stopRuntime()
-    }
-
-    private func stopRuntime() async {
-
         await self.supervisor.stop()
         await self.puncherActor.stop()
         await self.arpServer.clear()
@@ -520,14 +545,10 @@ actor SDLContextActor {
         self.quicClient?.stop()
         self.quicClient = nil
         
-        await self.dnsClient?.stop()
+        self.dnsClient?.stop()
-        self.dnsWorker?.cancel()
-        self.dnsWorker = nil
         self.dnsClient = nil
         
         await self.dnsLocalClient?.stop()
-        self.dnsLocalWorker?.cancel()
-        self.dnsLocalWorker = nil
         self.dnsLocalClient = nil
                 
         self.readTask?.cancel()

Tun/Punchnet/DNS/DNSLocalClient.swift

@@ -20,48 +20,61 @@ actor DNSLocalClient {
         case stopped
     }
     
-    private var state: State = .idle
+    enum Event {
-    private var connections: [NWConnection] = []
+        case failed(Error)
-    private var receiveTasks: [ObjectIdentifier: Task<Void, Never>] = [:]
+        case cancelled
-    private let dnsServers = ["223.5.5.5", "119.29.29.29"]
+        case sendFailed(Error)
+    }
     
-    let packetFlow: AsyncStream<Data>
+    private var state: State = .idle
+    
+    private let dnsServerEndpoint: NWEndpoint
+    private var connection: NWConnection?
+    private var receiveTask: Task<Void, Never>?
+    
+    private var cleanupTask: Task<Void, Never>?
+    private let timeoutInterval: TimeInterval = 3.0
+    
+    
+    
+    public let packetFlow: AsyncStream<Data>
+    @ObservationIgnored
     private let packetContinuation: AsyncStream<Data>.Continuation
     
+    // 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
    
-    private var cleanupTask: Task<Void, Never>?
+    init(host: String) {
-    private let timeoutInterval: TimeInterval = 3.0
+        self.dnsServerEndpoint = .hostPort(host: NWEndpoint.Host(host), port: 53)
-    private var didFinishPacketFlow = false
         
-    init() {
         let (stream, continuation) = AsyncStream.makeStream(of: Data.self, bufferingPolicy: .bufferingNewest(256))
         self.packetFlow = stream
         self.packetContinuation = continuation
+        
+        let eventPair = AsyncStream.makeStream(of: Event.self)
+        self.eventStream = eventPair.stream
+        self.eventContinuation = eventPair.continuation
     }
     
     func start() {
-        guard case .idle = self.state else {
-            return
-        }
-        
-        self.state = .running
-        
-        for server in self.dnsServers {
-            let endpoint = NWEndpoint.hostPort(host: NWEndpoint.Host(server), port: 53)
         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）
+        parameters.multipathServiceType = .handover
         
-            let conn = NWConnection(to: endpoint, using: parameters)
+        let connection = NWConnection(to: self.dnsServerEndpoint, using: parameters)
-            conn.stateUpdateHandler = { [weak self] state in
+        connection.stateUpdateHandler = { [weak self] state in
             Task {
-                    await self?.handleConnectionStateUpdate(state, for: conn)
+                await self?.handleConnectionStateUpdate(state, for: connection)
             }
         }
-            conn.start(queue: .global())
+        connection.start(queue: .global())
-            self.connections.append(conn)
+        self.connection = connection
-        }
         
         self.cleanupTask = Task { [weak self] in
             while !Task.isCancelled {
@@ -72,7 +85,7 @@ actor DNSLocalClient {
     }
     
     func query(tracker: DNSTracker, dnsPayload: Data) {
-        guard case .running = self.state, dnsPayload.count >= 2 else {
+        guard let connection = self.connection, connection.state == .ready, dnsPayload.count >= 2 else {
             return
         }
         
@@ -84,19 +97,18 @@ actor DNSLocalClient {
         self.pendingRequests[transactionID] = PendingRequest(tracker: tracker)
         let rewrittenPayload = Self.rewriteTransactionID(in: dnsPayload, to: transactionID)
         
-        var hasReadyConnection = false
+        connection.send(content: rewrittenPayload, completion: .contentProcessed { error in
-        for conn in self.connections where conn.state == .ready {
-            hasReadyConnection = true
-            conn.send(content: rewrittenPayload, completion: .contentProcessed({ error in
             if let error {
-                    SDLLogger.log("[DNSLocalClient] send error: \(error.localizedDescription)", for: .debug)
+                self.eventContinuation.yield(.sendFailed(error))
+                Task {
+                    await self.removePendingRequest(forKey: transactionID)
                 }
-            }))
+            }
+        })
     }
     
-        if !hasReadyConnection {
+    private func removePendingRequest(forKey id: UInt16) {
-            self.pendingRequests.removeValue(forKey: transactionID)
+        self.pendingRequests.removeValue(forKey: id)
-        }
     }
     
     func stop() {
@@ -105,69 +117,52 @@ actor DNSLocalClient {
         }
         
         self.state = .stopped
-        self.receiveTasks.values.forEach { $0.cancel() }
+        
-        self.receiveTasks.removeAll()
+        self.receiveTask?.cancel()
-        self.connections.forEach { $0.cancel() }
+        self.receiveTask = nil
-        self.connections.removeAll()
+        
+        self.connection?.cancel()
+        self.connection = nil
         
         self.cleanupTask?.cancel()
         self.cleanupTask = nil
         
         self.pendingRequests.removeAll()
         self.nextTransactionID = 1
-        self.finishPacketFlowIfNeeded()
+        
+        self.packetContinuation.finish()
     }
     
     private func handleConnectionStateUpdate(_ state: NWConnection.State, for conn: NWConnection) {
-        guard case .running = self.state else {
-            return
-        }
-        
         switch state {
         case .ready:
             self.startReceiveTask(for: conn)
+            self.state = .running
         case .failed(let error):
             SDLLogger.log("[DNSLocalClient] failed with error: \(error.localizedDescription)", for: .debug)
-            self.stop()
+            self.eventContinuation.yield(.failed(error))
         case .cancelled:
-            let key = ObjectIdentifier(conn)
+            self.eventContinuation.yield(.cancelled)
-            self.receiveTasks.removeValue(forKey: key)?.cancel()
-            self.connections.removeAll { $0 === conn }
-            if self.connections.isEmpty {
-                self.stop()
-            }
         default:
             ()
         }
     }
     
     private func startReceiveTask(for conn: NWConnection) {
-        let key = ObjectIdentifier(conn)
-        guard self.receiveTasks[key] == nil else {
-            return
-        }
-        
         let stream = Self.makeReceiveStream(for: conn)
-        self.receiveTasks[key] = Task { [weak self] in
+        
+        self.receiveTask = Task { [weak self] in
             for await data in stream {
                 guard let self else {
                     break
                 }
                 await self.handleResponse(data: data)
             }
-            
-            await self?.didFinishReceiving(for: conn)
         }
     }
     
-    private func didFinishReceiving(for conn: NWConnection) {
-        let key = ObjectIdentifier(conn)
-        self.receiveTasks.removeValue(forKey: key)
-    }
-    
     private func handleResponse(data: Data) {
-        guard case .running = self.state,
+        guard let rewrittenTransactionID = Self.readTransactionID(from: data),
-              let rewrittenTransactionID = Self.readTransactionID(from: data),
               let pendingRequest = self.pendingRequests.removeValue(forKey: rewrittenTransactionID) else {
             return
         }
@@ -185,10 +180,6 @@ actor DNSLocalClient {
     }
     
     private func performCleanup() {
-        guard case .running = self.state else {
-            return
-        }
-        
         let now = Date()
         self.pendingRequests = self.pendingRequests.filter { _, request in
             now.timeIntervalSince(request.tracker.createdAt) < self.timeoutInterval
@@ -211,15 +202,6 @@ actor DNSLocalClient {
         return nil
     }
     
-    private func finishPacketFlowIfNeeded() {
-        guard !self.didFinishPacketFlow else {
-            return
-        }
-        
-        self.didFinishPacketFlow = true
-        self.packetContinuation.finish()
-    }
-    
     private static func nextTransactionID(after id: UInt16) -> UInt16 {
         return id == UInt16.max ? 1 : id &+ 1
     }