fix dns

Tun/Punchnet/DNS/DNSLocalClient.swift

@@ -12,14 +12,18 @@ final class DNSLocalClient {
     
     private var connections: [NWConnection] = []
     
-    // 准备多个公共 DNS
-    private let dnsServers = ["114.114.114.114", "223.5.5.5", "8.8.8.8"]
-    
+    // 阿里云 + 腾讯云
+    private let dnsServers = ["223.5.5.5", "119.29.29.29"]
+
     public let packetFlow: AsyncStream<Data>
     private let packetContinuation: AsyncStream<Data>.Continuation
     
     private let locker = NSLock()
     private var trackers: [UInt16: [DNSTracker]] = [:]
+    
+    // 定期的任务清理
+    private var cleanupTask: Task<Void, Never>?
+    private let timeoutInterval: TimeInterval = 10.0 // 超过10秒认为丢包
 
     init() {
         let (stream, continuation) = AsyncStream.makeStream(of: Data.self, bufferingPolicy: .unbounded)
@@ -52,11 +56,21 @@ final class DNSLocalClient {
             
             connections.append(conn)
         }
+        
+        // 启动清理循环
+        self.cleanupTask = Task { [weak self] in
+            while !Task.isCancelled {
+                // 每隔 cleanupTick 秒运行一次
+                try? await Task.sleep(nanoseconds: 5 * 1_000_000_000)
+                self?.performCleanup()
+            }
+        }
     }
 
     /// 并发查询：对所有服务器广播
     func query(tracker: DNSTracker, dnsPayload: Data) {
         locker.lock()
+        SDLLogger.shared.log("[DNSLocalClient] query transId: \(tracker.transactionID)")
         self.trackers[tracker.transactionID, default: []].append(tracker)
         locker.unlock()
         
@@ -71,6 +85,7 @@ final class DNSLocalClient {
                 // ！！！核心：由于 AsyncStream 是流式的
                 // 谁先 yield，上层就先收到谁。
                 // 只要上层收到了第一个有效响应并回填给系统，
+                SDLLogger.shared.log("[DNSLocalClient] get response data: \(data.count)")
                 self?.handleResponse(data: data)
             }
             
@@ -91,6 +106,8 @@ final class DNSLocalClient {
         let items = self.trackers.removeValue(forKey: tranId)
         locker.unlock()
         
+        SDLLogger.shared.log("[DNSLocalClient] transId: \(tranId) get response items: \(items?.count)")
+
         items?.forEach { tracker in
             let packet = Self.createDNSResponse(
                 payload: data,
@@ -103,11 +120,33 @@ final class DNSLocalClient {
         }
     }
     
+    private func performCleanup() {
+        locker.lock()
+        defer {
+            locker.unlock()
+        }
+        
+        // 遍历所有 ID，过滤掉过期的 tracker
+        let now = Date()
+        for (id, list) in trackers {
+            let validItems = list.filter { now.timeIntervalSince($0.createdAt) < timeoutInterval }
+            
+            if validItems.isEmpty {
+                trackers.removeValue(forKey: id)
+            } else {
+                trackers[id] = validItems
+            }
+        }
+    }
+    
     func stop() {
         connections.forEach { conn in
             conn.cancel()
         }
         self.connections.removeAll()
+        
+        self.cleanupTask?.cancel()
+        self.cleanupTask = nil
     }
     
 }