fix dns转发

Tun/Punchnet/Actors/SDLContextActor.swift

@@ -693,7 +693,7 @@ actor SDLContextActor {
         }
     }
     
-    // 处理读取的每个数据包
+    // 处理读取的每个数据包, Tun收到的包的一级路由
     private func dealTunPacket(packet: IPPacket) async {
         let networkAddr = self.config.networkAddress
         let dstIp = packet.header.destination
@@ -704,7 +704,8 @@ actor SDLContextActor {
             self.provider.packetFlow.writePacketObjects([nePacket])
         }
         // 处理dns的解析
-        else if DNSHelper.isDnsRequestPacket(ipPacket: packet), case .udp(let udpPacket) = packet.transportPacket {
+        else if DNSHelper.isDnsRequestPacket(ipPacket: packet) {
+            if case .udp(let udpPacket) = packet.transportPacket {
                 // 数据是通过offset解析的, dns查询必然是udp包
                 let payloadOffset = udpPacket.payloadOffset
                 let dnsParser = DNSParser(data: packet.data, offset: payloadOffset)
@@ -714,12 +715,22 @@ actor SDLContextActor {
                         SDLLogger.log("[SDLContext] get cloud dns request: \(name)")
                         self.dnsClient?.forward(ipPacketData: packet.data)
                     }
+                    // 如果开启了出口节点，则转发给出口节点
+                    else if let exitNode = config.exitNode {
+                        let exitNodeIp = exitNode.exitNodeIp
+                        SDLLogger.log("[SDLContext] dstIp: \(packet.header.destination.asIpAddress()), use exit_node: \(exitNodeIp.asIpAddress())")
+                        // 查找arp缓存中是否有目标mac地址
+                        if let dstMac = await self.arpServer.query(ip: exitNodeIp) {
+                            await self.routeLayerPacket(dstMac: dstMac, type: .ipv4, data: packet.data)
+                        }
+                        else {
+                            try? await self.arpServer.arpRequest(targetIp: exitNodeIp, use: self.quicClient)
+                        }
+                    }
                     // 通过本地的dns解析，发送的是udp的payload部分
                     else {
-                    // 尝试解析下对不对
-                    let dnsPayload = Data(packet.data[payloadOffset..<packet.data.count])
                         SDLLogger.log("[SDLContext] get local dns request: \(name)")
-                    
+                        let dnsPayload = Data(packet.data[payloadOffset..<packet.data.count])
                         let tracker = DNSLocalClient.DNSTracker(transactionID: dnsMessage.transactionID,
                                                                 clientIP: packet.header.source,
                                                                 clientPort: udpPacket.srcPort,
@@ -728,6 +739,7 @@ actor SDLContextActor {
                     }
                 }
             }
+        }
         else {
             // 外部出去的数据，需要建立FlowSession
             // 外部数据进来的时候需要查找
@@ -739,7 +751,6 @@ actor SDLContextActor {
             // 判断目标地址是否和当前的网络地址是否在同一个网段
             // 只有在同一个网段的ip数据才直接发送
             if SDLUtil.inSameNetwork(ip: dstIp, compareIp: networkAddr.ip, maskLen: networkAddr.maskLen) {
-                SDLLogger.log("[SDLContext] read Tun packet step 3, data: \(Array(packet.data))", for: .trace)
                 // 查找arp缓存中是否有目标mac地址
                 if let dstMac = await self.arpServer.query(ip: dstIp) {
                     SDLLogger.log("[SDLContext] dstIp: \(dstIp.asIpAddress()), dst_mac is: \(SDLUtil.formatMacAddress(mac: dstMac))", for: .trace)
@@ -754,8 +765,7 @@ actor SDLContextActor {
                     try? await self.arpServer.arpRequest(targetIp: dstIp, use: self.quicClient)
                 }
             }
-            // 不在同一个网段的数据，看到是否配置了网络出口
+            // 不在同一个网段的数据，看是否配置了网络出口, 如果配置了，转发数据个网络出口，否则丢弃
-            // 如果配置了，转发数据个网络出口，否则丢弃
             else if let exitNode = config.exitNode {
                 let exitNodeIp: UInt32 = exitNode.exitNodeIp
                 SDLLogger.log("[SDLContext] dstIp: \(packet.header.destination.asIpAddress()), use exit_node: \(exitNodeIp.asIpAddress())")