解决dns的问题

Tun/PacketTunnelProvider.swift

@@ -23,12 +23,6 @@ class PacketTunnelProvider: NEPacketTunnelProvider {
         SDLLogger.shared.log("NE read message: \(msg ?? "failed")")
         
         DarwinNotificationCenter.shared.post(.vpnStatusChanged)
-
-        // host: "192.168.0.101", port: 1265
-        guard let options, let config = SDLConfiguration.parse(options: options) else {
-            completionHandler(TunnelError.invalidConfiguration)
-            return
-        }
         
         // 如果当前在运行状态，不允许重复请求
         guard self.contextActor == nil else {
@@ -39,6 +33,12 @@ class PacketTunnelProvider: NEPacketTunnelProvider {
         // 加密算法
         let rsaCipher = try! CCRSACipher(keySize: 1024)
         self.rootTask = Task {
+            // host: "192.168.0.101", port: 1265
+            guard let options, let config = await SDLConfiguration.parse(options: options) else {
+                completionHandler(TunnelError.invalidConfiguration)
+                return
+            }
+            
             self.contextActor = SDLContextActor(provider: self, config: config, rsaCipher: rsaCipher)
             await self.contextActor?.start()
             completionHandler(nil)

Tun/Punchnet/Actors/SDLContextActor.swift

@@ -103,6 +103,7 @@ actor SDLContextActor {
     }
     
     public func start() async {
+                
         self.startMonitor()
         
         // 启动arp的定时清理任务
@@ -233,7 +234,7 @@ actor SDLContextActor {
         self.dnsWorker = nil
         
         // 启动dns服务
-        let dnsClient = DNSCloudClient(host: self.config.serverHost, port: 15353, logger: SDLLogger.shared)
+        let dnsClient = DNSCloudClient(host: self.config.serverIp, port: 15353, logger: SDLLogger.shared)
         dnsClient.start()
         SDLLogger.shared.log("[SDLContext] dnsClient started")
         self.dnsClient = dnsClient
@@ -264,6 +265,8 @@ actor SDLContextActor {
                 if Task.isCancelled {
                     break
                 }
+                
+                // 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])
             }
@@ -693,8 +696,31 @@ actor SDLContextActor {
         let networkAddr = self.config.networkAddress
         
         if DNSHelper.isDnsRequestPacket(ipPacket: packet) {
+            // 数据是通过offset解析的, dns查询必然是udp包
+            if case .udp(let udpPacket) = packet.transportPacket {
+                let payloadOffset = udpPacket.payloadOffset
+                let dnsParser = DNSParser(data: packet.data, offset: payloadOffset)
+                if let dnsMessage = dnsParser.parse(), let name = dnsMessage.questions.first?.name {
+                    // 如果是内部域名，则转发整个ip包的内容到云端服务器
+                    if name.contains(self.config.networkAddress.networkDomain) {
+                        SDLLogger.shared.log("[Tun] get cloud dns request: \(name)")
+                        self.dnsClient?.forward(ipPacketData: packet.data)
+                    }
+                    // 通过本地的dns解析，发送的是udp的payload部分
+                    else if packet.data.count > payloadOffset {
+                        // 尝试解析下对不对
+                        let dnsPayload = Data(packet.data[payloadOffset..<packet.data.count])
+                        SDLLogger.shared.log("[Tun] get local dns request: \(name)")
+                        
+                        let tracker = DNSLocalClient.DNSTracker(transactionID: dnsMessage.transactionID, clientIP: packet.header.source, clientPort: udpPacket.srcPort, createdAt: Date())
+                        self.dnsLocalClient?.query(tracker: tracker, dnsPayload: dnsPayload)
+                    }
+                }
+            }
             self.dnsClient?.forward(ipPacketData: packet.data)
             return
+        } else {
+            return
         }
         
         let dstIp = packet.header.destination
@@ -812,8 +838,8 @@ actor SDLContextActor {
         let dnsSettings = NEDNSSettings(servers: [dnsServer])
 
         dnsSettings.searchDomains = [networkDomain]
-        dnsSettings.matchDomains = [networkDomain]
+        dnsSettings.matchDomains = [networkDomain, ""]
-        // 必须设置为 false，否则它会尝试接管全局解析
+        // 设置为 false 允许系统在补全 Search Domain 时也能匹配到此设置
         dnsSettings.matchDomainsNoSearch = false
         
         networkSettings.dnsSettings = dnsSettings
@@ -822,12 +848,6 @@ actor SDLContextActor {
         // 设置路由表
         ipv4Settings.includedRoutes = routes
         
-        let rs = self.getIpv4ExcludeRoutes()
-        
-        rs.forEach { x in
-            SDLLogger.shared.log("excludsL: \(x.destinationAddress)")
-        }
-
         // 配置要排除的路由
         ipv4Settings.excludedRoutes = self.getIpv4ExcludeRoutes()
         

Tun/Punchnet/DNS/DNSLocalClient.swift

@@ -2,6 +2,14 @@ import Foundation
 import Network
 
 final class DNSLocalClient {
+    // 需要保存DNS请求的追踪信息
+    struct DNSTracker {
+        let transactionID: UInt16
+        let clientIP: UInt32   // 原始包的源 IP (大端序)
+        let clientPort: UInt16 // 原始包的源端口 (大端序)
+        let createdAt: Date    // 用于超时清理
+    }
+    
     private var connections: [NWConnection] = []
     
     // 准备多个公共 DNS
@@ -9,6 +17,9 @@ final class DNSLocalClient {
     
     public let packetFlow: AsyncStream<Data>
     private let packetContinuation: AsyncStream<Data>.Continuation
+    
+    private let locker = NSLock()
+    private var trackers: [UInt16: [DNSTracker]] = [:]
 
     init() {
         let (stream, continuation) = AsyncStream.makeStream(of: Data.self, bufferingPolicy: .unbounded)
@@ -29,6 +40,7 @@ final class DNSLocalClient {
                 case .ready:
                     self?.receiveLoop(for: conn)
                 case .failed(let error):
+                    SDLLogger.shared.log("[DNSLocalClient] failed with error: \(error.localizedDescription)")
                     self?.stop()
                 case .cancelled:
                     self?.packetContinuation.finish()
@@ -43,7 +55,11 @@ final class DNSLocalClient {
     }
 
     /// 并发查询：对所有服务器广播
-    func query(dnsPayload: Data) {
+    func query(tracker: DNSTracker, dnsPayload: Data) {
+        locker.lock()
+        self.trackers[tracker.transactionID, default: []].append(tracker)
+        locker.unlock()
+        
         for conn in connections where conn.state == .ready {
             conn.send(content: dnsPayload, completion: .contentProcessed({ _ in }))
         }
@@ -55,8 +71,7 @@ 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，
-                // 后面迟到的重复响应会被系统协议栈自动忽略（因为 Transaction ID 已失效）
+                self?.handleResponse(data: data)
-                self?.packetContinuation.yield(data)
             }
             
             if error == nil && conn.state == .ready {
@@ -65,6 +80,30 @@ final class DNSLocalClient {
         }
     }
     
+    private func handleResponse(data: Data) {
+        let dnsParser = DNSParser(data: data, offset: 0)
+        if let message = dnsParser.parse() {
+            let tranId = message.transactionID
+            
+            locker.lock()
+            let items = self.trackers.removeValue(forKey: tranId)
+            locker.unlock()
+            
+            if let items {
+                items.forEach { tracker in
+                    let packet = Self.createDNSResponse(
+                        payload: data,
+                        srcIP: DNSHelper.dnsDestIpAddr,
+                        srcPort: 53,
+                        destIP: tracker.clientIP,
+                        destPort: tracker.clientPort
+                    )
+                    self.packetContinuation.yield(packet)
+                }
+            }
+        }
+    }
+    
     func stop() {
         connections.forEach { conn in
             conn.cancel()
@@ -73,3 +112,77 @@ final class DNSLocalClient {
     }
     
 }
+
+extension DNSLocalClient {
+    /// 构造发回 TUN 的完整 UDP/IPv4 数据包
+    static func createDNSResponse(payload: Data, srcIP: UInt32, srcPort: UInt16, destIP: UInt32, destPort: UInt16) -> Data {
+        let udpLen = 8 + payload.count
+        let ipLen = 20 + udpLen
+        
+        // --- 1. IPv4 Header (20 字节) ---
+        var ipHeader = Data(count: 20)
+        ipHeader[0] = 0x45 // Version 4, IHL 5
+        ipHeader[2...3] = withUnsafeBytes(of: UInt16(ipLen).bigEndian) { Data($0) }
+        ipHeader[8] = 64   // TTL
+        ipHeader[9] = 17   // Protocol UDP
+        
+        // 填充 IP 地址
+        ipHeader[12...15] = withUnsafeBytes(of: srcIP.bigEndian) { Data($0) }
+        ipHeader[16...19] = withUnsafeBytes(of: destIP.bigEndian) { Data($0) }
+        
+        // 计算 IP Checksum
+        let ipChecksum = calculateChecksum(data: ipHeader)
+        ipHeader[10...11] = withUnsafeBytes(of: ipChecksum.bigEndian) { Data($0) }
+        
+        // --- 2. UDP Header (8 字节) ---
+        var udpHeader = Data(count: 8)
+        udpHeader[0...1] = withUnsafeBytes(of: srcPort.bigEndian) { Data($0) }
+        udpHeader[2...3] = withUnsafeBytes(of: destPort.bigEndian) { Data($0) }
+        udpHeader[4...5] = withUnsafeBytes(of: UInt16(udpLen).bigEndian) { Data($0) }
+        // UDP Checksum 在 IPv4 中可选，设为 0 可跳过计算（大部分系统接受）
+        udpHeader[6...7] = Data([0, 0])
+        
+        // --- 3. 拼接 ---
+        var packet = Data(capacity: ipLen)
+        packet.append(ipHeader)
+        packet.append(udpHeader)
+        packet.append(payload)
+        
+        return packet
+    }
+    
+    /// 经典的 Internet Checksum 算法
+    static func calculateChecksum(data: Data) -> UInt16 {
+        var sum: UInt32 = 0
+        let count = data.count
+        
+        data.withUnsafeBytes { (ptr: UnsafeRawBufferPointer) in
+            guard let baseAddress = ptr.baseAddress else { return }
+            
+            // 1. 处理成对的 16-bit 单词
+            let wordCount = count / 2
+            let words = baseAddress.bindMemory(to: UInt16.self, capacity: wordCount)
+            
+            for i in 0..<wordCount {
+                // 使用 bigEndian: words[i] 是正确的，但要确保不越界
+                sum += UInt32(UInt16(bigEndian: words[i]))
+            }
+            
+            // 2. 关键修复：处理奇数长度的最后一个字节
+            if count % 2 != 0 {
+                // 获取最后一个字节，并左移 8 位（作为 16-bit 的高位）
+                let lastByte = ptr[count - 1]
+                sum += UInt32(lastByte) << 8
+            }
+        }
+        
+        // 3. 将进位加回低 16 位
+        while (sum >> 16) != 0 {
+            sum = (sum & 0xffff) + (sum >> 16)
+        }
+        
+        return UInt16(~sum & 0xffff)
+    }
+
+    
+}

Tun/Punchnet/DNS/DNSParser.swift

@@ -29,7 +29,9 @@ struct DNSMessage {
     var questions: [DNSQuestion] = []
     var answers: [DNSResourceRecord] = []
     
-    var isResponse: Bool { (flags & 0x8000) != 0 }
+    var isResponse: Bool {
+        (flags & 0x8000) != 0
+    }
 }
 
 // MARK: - DNS 完整解析器
@@ -37,13 +39,15 @@ final class DNSParser {
     private let data: Data
     private var offset: Int = 0
 
-    init(data: Data) {
+    init(data: Data, offset: Int) {
         self.data = data
+        self.offset = offset
     }
 
     func parse() -> DNSMessage? {
-        guard data.count >= 12 else { return nil }
+        guard data.count >= 12 + self.offset else {
-        offset = 0
+            return nil
+        }
         
         let id = readUInt16()
         let flags = readUInt16()
@@ -55,11 +59,17 @@ final class DNSParser {
         var message = DNSMessage(transactionID: id, flags: flags)
         
         for _ in 0..<qdCount {
-            if let q = parseQuestion() { message.questions.append(q) }
+            if let q = parseQuestion() {
+                message.questions.append(q)
+            }
         }
+        
         for _ in 0..<anCount {
-            if let rr = parseRR() { message.answers.append(rr) }
+            if let rr = parseRR() {
+                message.answers.append(rr)
+            }
         }
+        
         return message
     }
 

Tun/Punchnet/NetworkStack/IPPacket.swift

@@ -201,17 +201,20 @@ struct UDPPacket {
     let dstPort: UInt16
     let length: UInt16
     let checksum: UInt16
-
+    let payloadOffset: Int
+    
     init?(_ data: Data, offset: Int) {
         guard data.count >= offset + 8 else {
             return nil
         }
-
+        
         self.srcPort = UInt16(bytes: (data[offset], data[offset + 1]))
         self.dstPort = UInt16(bytes: (data[offset + 2], data[offset + 3]))
         self.length  = UInt16(bytes: (data[offset + 4], data[offset + 5]))
         self.checksum = UInt16(bytes: (data[offset + 6], data[offset + 7]))
+        self.payloadOffset = offset + 8
     }
+    
 }
 
 // MARK: - ICMP Packet

Tun/Punchnet/SDLConfiguration.swift

@@ -49,6 +49,7 @@ public class SDLConfiguration {
     let version: Int
     
     let serverHost: String
+    let serverIp: String
     let stunServers: [String]
     
     let noticePort: Int
@@ -78,6 +79,7 @@ public class SDLConfiguration {
     
     public init(version: Int,
                 serverHost: String,
+                serverIp: String,
                 stunServers: [String],
                 clientId: String,
                 networkAddress: NetworkAddress,
@@ -86,9 +88,9 @@ public class SDLConfiguration {
                 accessToken: String,
                 identityId: UInt32,
                 exitNode: ExitNode?) {
-        
         self.version = version
         self.serverHost = serverHost
+        self.serverIp = serverIp
         self.stunServers = stunServers
         self.clientId = clientId
         self.networkAddress = networkAddress
@@ -104,7 +106,7 @@ public class SDLConfiguration {
 // 解析配置文件
 extension SDLConfiguration {
     
-    static func parse(options: [String: NSObject]) -> SDLConfiguration? {
+    static func parse(options: [String: NSObject]) async -> SDLConfiguration? {
         guard let version = options["version"] as? Int,
               let serverHost = options["server_host"] as? String,
               let stunAssistHost = options["stun_assist_host"] as? String,
@@ -121,6 +123,11 @@ extension SDLConfiguration {
             return nil
         }
         
+        // 解析dns域名所在的服务器地址
+        guard let serverIp = await SDLUtil.resolveHostname(host: serverHost) else {
+            return nil
+        }
+        
         // 网络出口配置是可选的
         var exitNode: ExitNode? = nil
         if let exitNodeIpStr = options["exit_node_ip"] as? String, let exitNodeIp = SDLUtil.ipv4StrToInt32(exitNodeIpStr) {
@@ -129,6 +136,7 @@ extension SDLConfiguration {
         
         return SDLConfiguration(version: version,
                                 serverHost: serverHost,
+                                serverIp: serverIp,
                                 stunServers: [serverHost, stunAssistHost],
                                 clientId: clientId,
                                 networkAddress: networkAddress,

Tun/Punchnet/SDLUtil.swift

@@ -7,6 +7,7 @@
 
 import Foundation
 import SystemConfiguration
+import Network
 
 struct SDLUtil {
     
@@ -76,5 +77,31 @@ struct SDLUtil {
         }
         return results
     }
+    
+    // 域名解析
+    static func resolveHostname(host: String) async -> String? {
+        let endpoint = NWEndpoint.hostPort(host: NWEndpoint.Host(host), port: 53)
+        let parameters = NWParameters.udp
+        // 即使还没正式开始，也加上这个，确保不会被残留的旧 utun 路由卡死
+        parameters.prohibitedInterfaceTypes = [.other]
+        
+        let connection = NWConnection(to: endpoint, using: parameters)
+        
+        return await withCheckedContinuation { continuation in
+            connection.stateUpdateHandler = { state in
+                if case .ready = state {
+                    if let path = connection.currentPath,
+                       case .hostPort(let resolvedHost, _) = path.remoteEndpoint {
+                        let ip = String(describing: resolvedHost)
+                        continuation.resume(returning: ip)
+                        connection.cancel()
+                    }
+                } else if case .failed = state {
+                    continuation.resume(returning: nil)
+                }
+            }
+            connection.start(queue: .global())
+        }
+    }
 
 }