Android,NSD / DNS-SD:NsdManager不可靠的发现和IPparsing

在过去的几周里,Android的NSD实现让我发疯:

从用户的angular度来看,会出现以下问题:

我现在已经提交了有关Google代码的错误报告( https://code.google.com/p/android/issues/detail?id=201314&thanks=201314&ts=1455814995 )。 我也在这里张贴这个,希望得到更多的反馈; 也许我在我的Nsd helper类中有错误的东西。

首先,经过无尽的debugging,现在我已经在logcat中发现了一些提示,说明Android的底层NsdService本身可能出现故障,而MDnsDS似乎正常工作。 但是我不确定…

下面是一些说明问题的日志输出(为了可读性过滤了一些消息):

 02-18 16:57:02.327: D/NsdService(628): startMDnsDaemon 02-18 16:57:02.327: D/MDnsDS(187): Starting MDNSD 02-18 16:57:02.529: D/NsdService(628): New client listening to asynchronous messages 02-18 16:57:02.529: D/NsdService(628): New client, channel: com.android.internal.util.AsyncChannel@1fa188ce messenger: android.os.Messenger@cca33ef 02-18 16:57:02.532: D/NsdService(628): Register service 02-18 16:57:02.532: D/NsdService(628): registerService: 106 name: TuSync-0.57392, type: _tusync._tcp., host: /::, port: 57392 02-18 16:57:02.533: D/MDnsDS(187): serviceRegister(106, (null), TuSync-0.57392, _tusync._tcp., (null), (null), 57392, 0, <binary>) 02-18 16:57:02.533: D/MDnsDS(187): serviceRegister successful 02-18 16:57:02.534: D/NsdService(628): Register 1 106 02-18 16:57:04.083: D/MDnsDS(187): register succeeded for 106 as TuSync-0.57392 02-18 16:57:04.087: D/NsdService(628): SERVICE_REGISTERED Raw: 606 106 "TuSync-0.57392" 02-18 16:57:04.109: D/NsdService(628): Discover services 02-18 16:57:04.109: D/NsdService(628): discoverServices: 107 _tusync._tcp. 02-18 16:57:04.110: D/MDnsDS(187): discover((null), _tusync._tcp., (null), 107, 0) 02-18 16:57:04.110: D/MDnsDS(187): discover successful 02-18 16:57:04.110: D/NsdService(628): Discover 2 107_tusync._tcp. 02-18 16:57:04.333: D/MDnsDS(187): Discover found new serviceName TuSync-0.57392, regType _tusync._tcp. and domain local. for 107 02-18 16:57:04.334: D/NsdService(628): SERVICE_FOUND Raw: 603 107 "TuSync-0.57392" _tusync._tcp. local. 02-18 16:57:04.338: D/NsdService(628): Resolve service 02-18 16:57:04.338: D/NsdService(628): resolveService: 108 name: TuSync-0.57392, type: _tusync._tcp., host: null, port: 0 02-18 16:57:04.339: D/MDnsDS(187): resolveService(108, (null), TuSync-0.57392, _tusync._tcp., local.) 02-18 16:57:04.345: D/MDnsDS(187): startMonitoring 108 02-18 16:57:04.345: D/MDnsDS(187): resolveService successful 02-18 16:57:04.346: D/MDnsDS(187): resolve succeeded for 108 finding TuSync-0\.57392._tusync._tcp.local. at Android-3.local.:57392 with txtLen 1 02-18 16:57:04.347: D/NsdService(628): SERVICE_RESOLVED Raw: 608 108 "TuSync-0\\.57392._tusync._tcp.local." "Android-3.local." 57392 1 02-18 16:57:04.347: D/NsdService(628): stopResolveService: 108 02-18 16:57:04.347: D/MDnsDS(187): Stopping resolve with ref 0xb5c4734c 02-18 16:57:04.349: D/NsdService(628): getAdddrInfo: 109 02-18 16:57:04.349: D/MDnsDS(187): getAddrInfo(109, (null) 0, Android-3.local.) 02-18 16:57:04.350: D/MDnsDS(187): getAddrInfo successful 02-18 16:57:04.352: D/MDnsDS(187): getAddrInfo succeeded for 109: 109 "Android-3.local." 120 10.0.0.4 02-18 16:57:04.352: D/MDnsDS(187): getAddrInfo succeeded for 109: 109 "Android-3.local." 120 fe80::204:4bff:fe2c:6c87 02-18 16:57:04.354: D/NsdService(628): SERVICE_GET_ADDR_SUCCESS Raw: 612 109 "Android-3.local." 120 10.0.0.4 02-18 16:57:04.354: D/NsdService(628): stopGetAdddrInfo: 109 02-18 16:57:04.355: D/MDnsDS(187): Stopping getaddrinfo with ref 0xb5c472d4 02-18 16:57:04.364: E/NsdService(628): Unique id with no client mapping: 109 02-18 16:57:04.364: E/NsdService(628): Unhandled { when=-10ms what=393242 obj=com.android.server.NsdService$NativeEvent@86af300 target=com.android.internal.util.StateMachine$SmHandler } 02-18 16:57:04.627: D/MDnsDS(187): Discover found new serviceName TuSync-0.36230, regType _tusync._tcp. and domain local. for 107 02-18 16:57:04.632: D/MDnsDS(187): Discover found new serviceName TuSync-0.60493, regType _tusync._tcp. and domain local. for 107 02-18 16:57:04.633: D/NsdService(628): SERVICE_FOUND Raw: 603 107 "TuSync-0.36230" _tusync._tcp. local. 02-18 16:57:04.634: D/NsdService(628): SERVICE_FOUND Raw: 603 107 "TuSync-0.60493" _tusync._tcp. local. 02-18 16:57:04.635: D/NsdService(628): Resolve service 02-18 16:57:04.635: D/NsdService(628): resolveService: 110 name: TuSync-0.36230, type: _tusync._tcp., host: null, port: 0 02-18 16:57:04.636: D/MDnsDS(187): resolveService(110, (null), TuSync-0.36230, _tusync._tcp., local.) 02-18 16:57:04.637: D/MDnsDS(187): resolve succeeded for 110 finding TuSync-0\.36230._tusync._tcp.local. at Android.local.:36230 with txtLen 1 02-18 16:57:04.638: D/NsdService(628): Resolve service 02-18 16:57:04.638: D/NsdService(628): SERVICE_RESOLVED Raw: 608 110 "TuSync-0\\.36230._tusync._tcp.local." "Android.local." 36230 1 02-18 16:57:04.639: D/NsdService(628): stopResolveService: 110 02-18 16:57:04.639: D/MDnsDS(187): Stopping resolve with ref 0xb5c473c4 02-18 16:57:04.643: D/MDnsDS(187): getAddrInfo succeeded for 111: 111 "Android.local." 120 10.0.0.5 02-18 16:57:04.643: D/MDnsDS(187): getAddrInfo succeeded for 111: 111 "Android.local." 120 fe80::204:4bff:fe26:8483 02-18 16:57:04.644: D/NsdService(628): SERVICE_GET_ADDR_SUCCESS Raw: 612 111 "Android.local." 120 10.0.0.5 02-18 16:57:04.644: D/NsdService(628): stopGetAdddrInfo: 111 02-18 16:57:04.645: D/MDnsDS(187): Stopping getaddrinfo with ref 0xb5c47364 02-18 16:57:04.645: D/MDnsDS(187): Going to poll with pollCount 3 02-18 16:57:04.658: E/NsdService(628): Unique id with no client mapping: 111 02-18 16:57:04.658: E/NsdService(628): Unhandled { when=-14ms what=393242 obj=com.android.server.NsdService$NativeEvent@1d93a739 target=com.android.internal.util.StateMachine$SmHandler } 

关于上下文的一些说明:

  • 我的NSD服务types是_tusync._tcp。
  • 我为TuSync-0。[本地端口号]格式的所有节点创build唯一的服务名称,以防止命名冲突和简化debugging。
  • 在这个testing场景中,有三个设备。 日志logging设备的IP是10.0.0.4,端口57392。

日志显示,底层MDnsDS守护进程正确发现并parsing所有节点。 但是,上面的NsdService并不传播所有这些解决scheme。 在16:57:04.627似乎有一个ID冲突,其中设备的同级(TuSync-0.36230和TuSync-0.60493)被分配一个内部ID为107(如果我通过查看日志正确解释机制) 。 我在NsdManager注册的NsdManager会在发现这两个节点时得到通知,但parsing仅适用于其中的一个,另一个触发错误:

 02-18 16:57:04.638: E/NsdHelper(6370): Resolve failed with error code: 3. Service: name: TuSync-0.60493, type: _tusync._tcp., host: null, port: 0 

我还遇到过额外的情况,在NsdService在日志中发出“SERVICE_FOUND Raw”消息之后,我的发现侦听器不会被通知。 一个典型的日志(严重过滤;与上面相同的testing设置):

 02-18 17:54:06.692: D/MDnsDS(187): Starting MDNSD 02-18 17:54:06.896: D/NsdService(628): registerService: 112 name: TuSync-0.57392, type: _tusync._tcp., host: /::, port: 57392 02-18 17:54:06.896: D/MDnsDS(187): serviceRegister(112, (null), TuSync-0.57392, _tusync._tcp., (null), (null), 57392, 0, <binary>) 02-18 17:54:06.896: D/MDnsDS(187): serviceRegister successful 02-18 17:54:08.802: D/NsdService(628): SERVICE_REGISTERED Raw: 606 112 "TuSync-0.57392" 02-18 17:54:08.820: D/NsdService(628): Discover services 02-18 17:54:09.050: D/MDnsDS(187): Discover found new serviceName TuSync-0.57392, regType _tusync._tcp. and domain local. for 113 02-18 17:54:09.050: D/NsdService(628): SERVICE_FOUND Raw: 603 113 "TuSync-0.57392" _tusync._tcp. local. 02-18 17:54:09.211: D/MDnsDS(187): Discover found new serviceName TuSync-0.60493, regType _tusync._tcp. and domain local. for 113 02-18 17:54:09.212: D/NsdService(628): SERVICE_FOUND Raw: 603 113 "TuSync-0.60493" _tusync._tcp. local. 02-18 17:54:09.215: D/NsdService(628): resolveService: 116 name: TuSync-0.60493, type: _tusync._tcp., host: null, port: 0 02-18 17:54:09.216: D/MDnsDS(187): resolveService(116, (null), TuSync-0.60493, _tusync._tcp., local.) 02-18 17:54:09.217: D/MDnsDS(187): resolve succeeded for 116 finding TuSync-0\.60493._tusync._tcp.local. at Android-2.local.:60493 with txtLen 1 02-18 17:54:09.219: D/NsdService(628): SERVICE_RESOLVED Raw: 608 116 "TuSync-0\\.60493._tusync._tcp.local." "Android-2.local." 60493 1 02-18 17:54:09.228: D/MDnsDS(187): getAddrInfo succeeded for 117: 117 "Android-2.local." 120 10.0.0.6 02-18 17:54:09.228: D/MDnsDS(187): getAddrInfo succeeded for 117: 117 "Android-2.local." 120 fe80::c643:8fff:fec5:5648 02-18 17:54:09.229: D/NsdService(628): SERVICE_GET_ADDR_SUCCESS Raw: 612 117 "Android-2.local." 120 10.0.0.6 02-18 17:54:09.244: D/MDnsDS(187): Discover found new serviceName TuSync-0.36230, regType _tusync._tcp. and domain local. for 113 02-18 17:54:09.251: E/NsdService(628): Unique id with no client mapping: 117 02-18 17:54:09.251: E/NsdService(628): Unhandled { when=-22ms what=393242 obj=com.android.server.NsdService$NativeEvent@1e992653 target=com.android.internal.util.StateMachine$SmHandler } 02-18 17:54:09.255: D/NsdService(628): SERVICE_FOUND Raw: 603 113 "TuSync-0.36230" _tusync._tcp. local. 

在这种情况下,发现的对等端10.0.0.5(端口36230)不触发discoveryListener通知。 在最后的日志消息之后,没有任何反应。 所以我的日志logging节点10.0.0.4只发现了另一个对等体10.0.0.6:60493。

less量类似的错误报告让我怀疑,如果我是唯一一个有这些问题,或者如果NsdManager是完全不稳定的,没有人使用它呢?

作为参考,这里是我的帮手类的代码 – 它类似于Android的NSD聊天教程,但我试图改进它,因为该教程似乎引起的其他一些错误。

 public final class NsdHelper { public static final String TAG = "NsdHelper"; private final Context mContext; private final NsdManager mNsdManager; private final String mBaseServiceName; // Base component of the service name, eg "service_xy" private String mServiceName; // Service name of the local node, may be updated upon peer detection with service name conflicts, eg to "service_xy (2)" private final String mServiceType; private final NsdHandler mNsdHandler; private MyRegistrationListener mRegistrationListener; private final Object mRegistrationLock = new Object(); private MyDiscoveryListener mDiscoveryListener; private final Object mDiscoveryLock = new Object(); private final Object mResolveLock = new Object(); private final Semaphore mResolveSemaphore; public NsdHelper(Context context, String baseServiceName, String serviceName, String serviceType, NsdHandler nsdHandler) { mContext = context; mNsdManager = (NsdManager) context.getSystemService(Context.NSD_SERVICE); mNsdHandler = nsdHandler; mBaseServiceName = baseServiceName; mServiceName = serviceName; mServiceType = serviceType; mResolveSemaphore = new Semaphore(10, true); } /********************* * Lifecycle methods * *********************/ public void registerLocalService(final int port) { NsdServiceInfo localServiceInfo = new NsdServiceInfo(); localServiceInfo.setServiceName(mServiceName); localServiceInfo.setServiceType(mServiceType); localServiceInfo.setPort(port); synchronized (mRegistrationLock) { if (mRegistrationListener == null) { mRegistrationListener = new MyRegistrationListener(); // try { mNsdManager.registerService( localServiceInfo, NsdManager.PROTOCOL_DNS_SD, mRegistrationListener); /*} catch (Exception e) { MLog.e(TAG, "Exception registering service; trying to unregister.", e); unregisterLocalService(); mNsdHandler.onRegistrationFailed(localServiceInfo, 0); }*/ } else { MLog.w(TAG, "registerLocalService called while service registration already in progress or service already registered."); } } } public void unregisterLocalService() { synchronized (mRegistrationLock) { if (mRegistrationListener != null) { // try { mNsdManager.unregisterService(mRegistrationListener); /*} catch (IllegalArgumentException e) { MLog.w(TAG, "Exception trying to unregister registrationListener."); }*/ mRegistrationListener = null; } else { MLog.w(TAG, "unregisterLocalService called while service not yet registered or already unregistered."); } } } public void startDiscovery() { synchronized(mDiscoveryLock) { if(mDiscoveryListener == null) { mDiscoveryListener = new MyDiscoveryListener(); mNsdManager.discoverServices( mServiceType, NsdManager.PROTOCOL_DNS_SD, mDiscoveryListener); } else { MLog.w(TAG, "StartDiscovery called while discovery is already in progress."); } } } public void stopDiscovery() { synchronized (mDiscoveryLock) { if (mDiscoveryListener != null) { mNsdManager.stopServiceDiscovery(mDiscoveryListener); mDiscoveryListener = null; } else { MLog.w(TAG, "StopDiscovery called while no discovery is in progress."); } } } public void tearDown() { MLog.v(TAG, "NsdHelper: tearDown()"); stopDiscovery(); unregisterLocalService(); // TODO this causes an exception, when the listener is already unregistered } /** * Returns the current service name of the service. * @return */ public String getServiceName() { return mServiceName; } /** * Convenience method to initiate service resolution * @param serviceInfo NsdServiceInfo object for the service to be resolved */ private void resolveService(NsdServiceInfo serviceInfo) { try { MLog.vv(TAG, "Resolving service: acquiring semaphore."); mResolveSemaphore.acquire(); MLog.vv(TAG, "Resolving service: semaphore acquired."); } catch (InterruptedException e) { MLog.w(TAG, "resolveService: Waiting for acquisition of semaphore interrupted."); } mNsdManager.resolveService(serviceInfo, new MyResolveListener(serviceInfo.getServiceName())); } /************* * Listeners * *************/ private class MyDiscoveryListener implements NsdManager.DiscoveryListener { @Override public void onDiscoveryStarted(String regType) { MLog.d(TAG, "Service discovery started"); mNsdHandler.onDiscoveryStarted(); } @Override public void onServiceFound(NsdServiceInfo serviceInfo) { MLog.d(TAG, "Discovered service: " + serviceInfo); // Protocol matches? if (!serviceInfo.getServiceType().equals(mServiceType)) { MLog.v(TAG, "Discovered: other serviceType: " + serviceInfo.getServiceType()); } // Make sure, that service name matches, and just resolve remote host else if (serviceInfo.getServiceName().contains(mBaseServiceName)){ MLog.d(TAG, "Discovered: correct serviceType: " + mBaseServiceName); resolveService(serviceInfo); } else { // Other service name, log anyway MLog.d(TAG, "Discovered: service with different serviceName: " + serviceInfo.getServiceName() + ". Ignoring."); } } @Override public void onServiceLost(NsdServiceInfo service) { MLog.e(TAG, "Service lost: " + service); mNsdHandler.onRemotePeerLost(service); } @Override public void onDiscoveryStopped(String serviceType) { MLog.v(TAG, "Discovery stopped: " + serviceType); mNsdHandler.onDiscoveryStopped(); } @Override public void onStartDiscoveryFailed(String serviceType, int errorCode) { MLog.e(TAG, "Discovery starting failed. Error code: " + errorCode); synchronized (mDiscoveryLock) { mDiscoveryListener = null; // just throw away the discovery listener, explicit stopping of the discovery should not be needed according to // https://code.google.com/p/android/issues/detail?id=99510&q=nsd&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars } } @Override public void onStopDiscoveryFailed(String serviceType, int errorCode) { MLog.e(TAG, "Discovery stopping failed. Error code: " + errorCode); // try again // mNsdManager.stopServiceDiscovery(this); // This should not be needed according to https://code.google.com/p/android/issues/detail?id=99510&q=nsd&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars } }; private class MyRegistrationListener implements NsdManager.RegistrationListener { @Override public void onServiceRegistered(NsdServiceInfo nsdServiceInfo) { MLog.d(TAG, "Service registered. NsdServiceInfo: " + nsdServiceInfo); boolean nameChanged = false; // Update service name of this node (might change due to automatic conflict resolution!) if(!mServiceName.equals(nsdServiceInfo.getServiceName())){ mServiceName = nsdServiceInfo.getServiceName(); nameChanged = true; MLog.d(TAG, "Local service name updated to: " + mServiceName); } // Notify if (mNsdHandler != null) { mNsdHandler.onRegistrationSuccess(nsdServiceInfo); if (nameChanged) { mNsdHandler.onLocalServiceNameChanged(mServiceName); } } else { MLog.w(TAG, "onServiceRegistered: NsdHandler is null."); } } @Override public void onRegistrationFailed(NsdServiceInfo arg0, int arg1) { MLog.w(TAG, "Service registration failed with error code " + arg1 + "."); if (mNsdHandler == null) { MLog.w(TAG, "onRegistrationFailed: NsdHandler is null."); return; } mNsdHandler.onRegistrationFailed(arg0, arg1); } @Override public void onServiceUnregistered(NsdServiceInfo arg0) { MLog.d(TAG, "Service unregistered."); if (mNsdHandler == null) { MLog.w(TAG, "onServiceUnRegistered: NsdHandler is null."); return; } } @Override public void onUnregistrationFailed(NsdServiceInfo serviceInfo, int errorCode) { MLog.w(TAG, "Service unregistering failed."); if (mNsdHandler == null) { MLog.w(TAG, "onUnRegistrationFailed: NsdHandler is null."); return; } } }; private class MyResolveListener implements NsdManager.ResolveListener { private final String mServiceName; public MyResolveListener(String serviceName) { mServiceName = serviceName; } @Override public void onResolveFailed(final NsdServiceInfo serviceInfo, int errorCode) { // Release resource mResolveSemaphore.release(); MLog.e(TAG, "Resolve failed with error code: " + errorCode + ". Service: " + serviceInfo); if((serviceInfo.getServiceName() != null) && (!serviceInfo.getServiceName().equals(mServiceName))) { MLog.e(TAG, "Service name changed: " + mServiceName + " => " + serviceInfo.getServiceName()); } } @Override public void onServiceResolved(final NsdServiceInfo serviceInfo) { // Release resource mResolveSemaphore.release(); MLog.v(TAG, "Resolve succeeded. Service: " + serviceInfo + ", Address: " + serviceInfo.getHost().getHostAddress() + ":" + serviceInfo.getPort()); if((serviceInfo.getServiceName() != null) && (!serviceInfo.getServiceName().equals(mServiceName))) { MLog.w(TAG, "Service name changed: " + mServiceName + " => " + serviceInfo.getServiceName()); } mNsdHandler.onNewRemotePeerResolved(serviceInfo); } }; /** * Interface for handlers that deal just with essential NSD events. * @author Alexander Fischl (alexander.fischl@semeion.net) */ public interface NsdHandler { /** * Called, when the NSD manager registered the service successfully. * @param nsdServiceInfo */ public void onRegistrationSuccess(final NsdServiceInfo nsdServiceInfo); /** * Called, when the NSD registration was unsuccessful. */ public void onRegistrationFailed(final NsdServiceInfo nsdServiceInfo, final int errorCode); /** * Called, when the NSD manager discovers a new peer. Services registered on the * local machine DO NOT trigger this call! * @param nsdServiceInfo */ public void onNewRemotePeerDiscovered(final NsdServiceInfo nsdServiceInfo); /** * Called, when the NSD manager resolves a new peer, yielding the connection data. * Services registered on the local machine DO NOT trigger this call! * @param nsdServiceInfo */ public void onNewRemotePeerResolved(final NsdServiceInfo nsdServiceInfo); /** * Called, when the NSD manager loses an already discovered peer. * @param nsdServiceInfo */ public void onRemotePeerLost(final NsdServiceInfo nsdServiceInfo); /** * Called, when the local service name needs to be updated (eg due to * conflict resolution when the local service is registered, and the chosen service * name is already taken by another node in the network.) * @param newLocalServiceName */ public void onLocalServiceNameChanged(String newLocalServiceName); /** * Called, when the service discovery has successfully started. */ public void onDiscoveryStarted(); /** * Called, when the service discovery was halted. */ public void onDiscoveryStopped(); } } 

请注意,我甚至实现了一个可以设置为1的信号量,以防止并行parsing多个服务,因为有人报告了并行parsing的问题。 然而,将它设置为1是行不通的,因为有时正在进行的决议既不成功也不失败; 这导致信号量不被释放,并且NsdManager线程在下一个parsing请求中永久停留。

有没有人遇到这样的问题? 如果成功使用NsdManager的人也会发表评论,我会很高兴 – 这至less意味着我面临一个问题,我可以修复:)

我已经考虑放弃NSD并实现我自己的广播/多播发现机制。 理论上这可能是一件轻而易举的事情,但我已经读过Android上的多播是一个PITA,因为有些设备阻止它…

Solutions Collecting From Web of "Android,NSD / DNS-SD:NsdManager不可靠的发现和IPparsing"

与Android NSD仍然没有什么不同。 我一直在使用Android和NSD的棉花糖版本,实际上依然不可靠。 我用RxDNSSDreplace了NSD( https://github.com/andriydruk/RxDNSSD )。 目前为止,很less有class轮码可以完美工作。

我testing了NSD和RXDNSSD,NSD能够发现服务,但是无法parsingIP地址,而RXDNSSD一直在工作。

希望它会帮助其他用户。