LineageOS/android_packages_modules_Connectivity
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Open network service discovery API

Browse Source 
Add support for DNS based network service discovery API. This
allows applications to discover and resolve applications on a
local network such as Wi-Fi

Change-Id: Ie89895edd35d12b7f7a23fb5fed36cb2b2079f7a
This commit is contained in:
Irfan Sheriff
2012-04-13 12:15:41 -07:00
parent 287e63bbb6
commit 18da1320fe
3 changed files with 281 additions and 93 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
core/java/android/net/nsd/DnsSdServiceInfo.java
View File

@@ -22,8 +22,8 @@ import android.os.Parcel;
import java.net.InetAddress;
/**
* Defines a service based on DNS service discovery
* {@hide}
* A class representing service information for network service discovery
* {@see NsdManager}
*/
public class DnsSdServiceInfo implements NetworkServiceInfo, Parcelable {
@@ -40,56 +40,63 @@ public class DnsSdServiceInfo implements NetworkServiceInfo, Parcelable {
public DnsSdServiceInfo() {
}
/** @hide */
public DnsSdServiceInfo(String sn, String rt, DnsSdTxtRecord tr) {
mServiceName = sn;
mServiceType = rt;
mTxtRecord = tr;
}
/** Get the service name */
@Override
/** @hide */
public String getServiceName() {
return mServiceName;
}
/** Set the service name */
@Override
/** @hide */
public void setServiceName(String s) {
mServiceName = s;
}
/** Get the service type */
@Override
/** @hide */
public String getServiceType() {
return mServiceType;
}
/** Set the service type */
@Override
/** @hide */
public void setServiceType(String s) {
mServiceType = s;
}
/** @hide */
public DnsSdTxtRecord getTxtRecord() {
return mTxtRecord;
}
/** @hide */
public void setTxtRecord(DnsSdTxtRecord t) {
mTxtRecord = new DnsSdTxtRecord(t);
}
/** Get the host address. The host address is valid for a resolved service. */
public InetAddress getHost() {
return mHost;
}
/** Set the host address */
public void setHost(InetAddress s) {
mHost = s;
}
/** Get port number. The port number is valid for a resolved service. */
public int getPort() {
return mPort;
}
/** Set port number */
public void setPort(int p) {
mPort = p;
}
@@ -147,5 +154,4 @@ public class DnsSdServiceInfo implements NetworkServiceInfo, Parcelable {
return new DnsSdServiceInfo[size];
}
};
}

340
core/java/android/net/nsd/NsdManager.java
View File

@@ -24,29 +24,110 @@ import android.os.Looper;
import android.os.Message;
import android.os.RemoteException;
import android.os.Messenger;
import android.text.TextUtils;
import android.util.Log;
import com.android.internal.util.AsyncChannel;
import com.android.internal.util.Protocol;
/**
* The Network Service Discovery Manager class provides the API for service
* discovery. Service discovery enables applications to discover and connect with services
* on a network. Example applications include a game application discovering another instance
* of the game application or a printer application discovering other printers on a network.
* The Network Service Discovery Manager class provides the API to discover services
* on a network. As an example, if device A and device B are connected over a Wi-Fi
* network, a game registered on device A can be discovered by a game on device
* B. Another example use case is an application discovering printers on the network.
*
* <p> The API currently supports DNS based service discovery and discovery is currently
* limited to a local network over Multicast DNS. In future, it will be extended to
* support wide area discovery and other service discovery mechanisms.
* DNS service discovery is described at http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt
*
* <p> The API is asynchronous and responses to requests from an application are on listener
* callbacks provided by the application. The application needs to do an initialization with
* {@link #initialize} before doing any operation.
* callbacks provided by the application. The application must invoke {@link #initialize} before
* doing any other operation.
*
* <p> Android currently supports DNS based service discovery and it is limited to a local
* network with the use of multicast DNS. In future, this class will be
* extended to support other service discovery mechanisms.
* <p> There are three main operations the API supports - registration, discovery and resolution.
* <pre>
* Application start
* |
* | <----------------------------------------------
* initialize() |
* | |
* | Wait until channel connects |
* | before doing any operation |
* | |
* onChannelConnected() __________ |
* | | |
* | | |
* | onServiceRegistered() | |
* Register any local services / | |
* to be advertised with \ | | If application needs to
* registerService() onFailure() | | do any further operations
* | | | again, it needs to
* | | | initialize() connection
* discoverServices() | | to framework again
* | | |
* Maintain a list to track | |
* discovered services | |
* | | |
* |---------> |-> onChannelDisconnected()
* | | |
* | onServiceFound() |
* | | |
* | add service to list |
* | | |
* |<---------- |
* | |
* |---------> |
* | | |
* | onServiceLost() |
* | | |
* | remove service from list |
* | | |
* |<---------- |
* | |
* | |
* | Connect to a service |
* | from list ? |
* | |
* resolveService() |
* | |
* onServiceResolved() |
* | |
* Establish connection to service |
* with the host and port information |
* | |
* | ___________|
* deinitialize()
* when done with all operations
* or before quit
*
* </pre>
* An application that needs to advertise itself over a network for other applications to
* discover it can do so with a call to {@link #registerService}. If Example is a http based
* application that can provide HTML data to peer services, it can register a name "Example"
* with service type "_http._tcp". A successful registration is notified with a callback to
* {@link DnsSdRegisterListener#onServiceRegistered} and a failure to register is notified
* over {@link DnsSdRegisterListener#onFailure}
*
* <p> A peer application looking for http services can initiate a discovery for "_http._tcp"
* with a call to {@link #discoverServices}. A service found is notified with a callback
* to {@link DnsSdDiscoveryListener#onServiceFound} and a service lost is notified on
* {@link DnsSdDiscoveryListener#onServiceLost}.
*
* <p> Once the peer application discovers the "Example" http srevice, and needs to receive data
* from the "Example" application, it can initiate a resolve with {@link #resolveService} to
* resolve the host and port details for the purpose of establishing a connection. A successful
* resolve is notified on {@link DnsSdResolveListener#onServiceResolved} and a failure is notified
* on {@link DnsSdResolveListener#onFailure}.
*
* Applications can reserve for a service type at
* http://www.iana.org/form/ports-service. Existing services can be found at
* http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml
*
* Get an instance of this class by calling {@link android.content.Context#getSystemService(String)
* Context.getSystemService(Context.NSD_SERVICE)}.
* @hide
*
* {@see DnsSdServiceInfo}
*/
public class NsdManager {
private static final String TAG = "NsdManager";
@@ -80,27 +161,32 @@ public class NsdManager {
public static final int REGISTER_SERVICE_SUCCEEDED = BASE + 11;
/** @hide */
public static final int UPDATE_SERVICE = BASE + 12;
public static final int UNREGISTER_SERVICE = BASE + 12;
/** @hide */
public static final int UPDATE_SERVICE_FAILED = BASE + 13;
public static final int UNREGISTER_SERVICE_FAILED = BASE + 13;
/** @hide */
public static final int UPDATE_SERVICE_SUCCEEDED = BASE + 14;
public static final int UNREGISTER_SERVICE_SUCCEEDED = BASE + 14;
/** @hide */
public static final int RESOLVE_SERVICE = BASE + 15;
public static final int UPDATE_SERVICE = BASE + 15;
/** @hide */
public static final int RESOLVE_SERVICE_FAILED = BASE + 16;
public static final int UPDATE_SERVICE_FAILED = BASE + 16;
/** @hide */
public static final int RESOLVE_SERVICE_SUCCEEDED = BASE + 17;
public static final int UPDATE_SERVICE_SUCCEEDED = BASE + 17;
/** @hide */
public static final int STOP_RESOLVE = BASE + 18;
public static final int RESOLVE_SERVICE = BASE + 18;
/** @hide */
public static final int STOP_RESOLVE_FAILED = BASE + 19;
public static final int RESOLVE_SERVICE_FAILED = BASE + 19;
/** @hide */
public static final int STOP_RESOLVE_SUCCEEDED = BASE + 20;
public static final int RESOLVE_SERVICE_SUCCEEDED = BASE + 20;
/** @hide */
public static final int STOP_RESOLVE = BASE + 21;
/** @hide */
public static final int STOP_RESOLVE_FAILED = BASE + 22;
/** @hide */
public static final int STOP_RESOLVE_SUCCEEDED = BASE + 23;
/**
* Create a new Nsd instance. Applications use
@@ -115,36 +201,44 @@ public class NsdManager {
}
/**
* Passed with onFailure() calls.
* Indicates that the operation failed due to an internal error.
*/
public static final int ERROR = 0;
/**
* Indicates that the operation failed because service discovery is unsupported on the device.
* Passed with onFailure() calls.
* Indicates that the operation failed because service discovery
* is unsupported on the device.
*/
public static final int UNSUPPORTED = 1;
/**
* Indicates that the operation failed because the framework is busy and
* unable to service the request.
* Passed with onFailure() calls.
* Indicates that the operation failed because the framework is
* busy and unable to service the request.
*/
public static final int BUSY = 2;
/**
* Passed with onFailure() calls.
* Indicates that the operation failed because it is already active.
*/
public static final int ALREADY_ACTIVE = 3;
/**
* Passed with onFailure() calls.
* Indicates that the operation failed because maximum limit on
* service registrations has reached.
*/
public static final int MAX_REGS_REACHED = 4;
/** Interface for callback invocation when framework channel is connected or lost */
public interface ChannelListener {
/**
* The channel to the framework is connected.
* Application can initiate calls into the framework using the channel instance passed.
*/
public void onChannelConnected(Channel c);
/**
* The channel to the framework has been disconnected.
@@ -153,6 +247,7 @@ public class NsdManager {
public void onChannelDisconnected();
}
/** Generic interface for callback invocation for a success or failure */
public interface ActionListener {
public void onFailure(int errorCode);
@@ -160,11 +255,12 @@ public class NsdManager {
public void onSuccess();
}
/** Interface for callback invocation for service discovery */
public interface DnsSdDiscoveryListener {
public void onFailure(int errorCode);
public void onStarted(String registrationType);
public void onStarted(String serviceType);
public void onServiceFound(DnsSdServiceInfo serviceInfo);
@@ -172,6 +268,7 @@ public class NsdManager {
}
/** Interface for callback invocation for service registration */
public interface DnsSdRegisterListener {
public void onFailure(int errorCode);
@@ -179,6 +276,7 @@ public class NsdManager {
public void onServiceRegistered(int registeredId, DnsSdServiceInfo serviceInfo);
}
/** @hide */
public interface DnsSdUpdateRegistrationListener {
public void onFailure(int errorCode);
@@ -186,6 +284,7 @@ public class NsdManager {
public void onServiceUpdated(int registeredId, DnsSdTxtRecord txtRecord);
}
/** Interface for callback invocation for service resolution */
public interface DnsSdResolveListener {
public void onFailure(int errorCode);
@@ -208,6 +307,7 @@ public class NsdManager {
private DnsSdDiscoveryListener mDnsSdDiscoveryListener;
private ActionListener mDnsSdStopDiscoveryListener;
private DnsSdRegisterListener mDnsSdRegisterListener;
private ActionListener mDnsSdUnregisterListener;
private DnsSdUpdateRegistrationListener mDnsSdUpdateListener;
private DnsSdResolveListener mDnsSdResolveListener;
private ActionListener mDnsSdStopResolveListener;
@@ -279,7 +379,17 @@ public class NsdManager {
(DnsSdServiceInfo) message.obj);
}
break;
case UPDATE_SERVICE_FAILED:
case UNREGISTER_SERVICE_FAILED:
if (mDnsSdUnregisterListener != null) {
mDnsSdUnregisterListener.onFailure(message.arg1);
}
break;
case UNREGISTER_SERVICE_SUCCEEDED:
if (mDnsSdUnregisterListener != null) {
mDnsSdUnregisterListener.onSuccess();
}
break;
case UPDATE_SERVICE_FAILED:
if (mDnsSdUpdateListener != null) {
mDnsSdUpdateListener.onFailure(message.arg1);
}
@@ -319,6 +429,10 @@ public class NsdManager {
}
}
private static void checkChannel(Channel c) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
}
/**
* Registers the application with the service discovery framework. This function
* must be the first to be called before any other operations are performed. No service
@@ -327,7 +441,7 @@ public class NsdManager {
*
* @param srcContext is the context of the source
* @param srcLooper is the Looper on which the callbacks are receivied
* @param listener for callback at loss of framework communication.
* @param listener for callback at loss of framework communication. Cannot be null.
*/
public void initialize(Context srcContext, Looper srcLooper, ChannelListener listener) {
Messenger messenger = getMessenger();
@@ -339,88 +453,142 @@ public class NsdManager {
}
/**
* Set the listener for service discovery. Can be null.
* Disconnects application from service discovery framework. No further operations
* will succeed until a {@link #initialize} is called again.
*
* @param c channel initialized with {@link #initialize}
*/
public void setDiscoveryListener(Channel c, DnsSdDiscoveryListener b) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
c.mDnsSdDiscoveryListener = b;
public void deinitialize(Channel c) {
checkChannel(c);
c.mAsyncChannel.disconnect();
}
/**
* Set the listener for stop service discovery. Can be null.
* Register a service to be discovered by other services.
*
* <p> The function call immediately returns after sending a request to register service
* to the framework. The application is notified of a success to initiate
* discovery through the callback {@link DnsSdRegisterListener#onServiceRegistered} or a failure
* through {@link DnsSdRegisterListener#onFailure}.
*
* @param c is the channel created at {@link #initialize}
* @param serviceType The service type being advertised.
* @param port on which the service is listenering for incoming connections
* @param listener for success or failure callback. Can be null.
*/
public void setStopDiscoveryListener(Channel c, ActionListener a) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
c.mDnsSdStopDiscoveryListener = a;
}
/**
* Set the listener for service registration. Can be null.
*/
public void setRegisterListener(Channel c, DnsSdRegisterListener b) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
c.mDnsSdRegisterListener = b;
}
/**
* Set the listener for service registration. Can be null.
*/
public void setUpdateRegistrationListener(Channel c, DnsSdUpdateRegistrationListener b) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
c.mDnsSdUpdateListener = b;
}
/**
* Set the listener for service resolution. Can be null.
*/
public void setResolveListener(Channel c, DnsSdResolveListener b) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
c.mDnsSdResolveListener = b;
}
/**
* Set the listener for stopping service resolution. Can be null.
*/
public void setStopResolveListener(Channel c, ActionListener b) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
c.mDnsSdStopResolveListener = b;
}
public void registerService(Channel c, DnsSdServiceInfo serviceInfo) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
if (serviceInfo == null) throw new IllegalArgumentException("Null serviceInfo");
public void registerService(Channel c, String serviceName, String serviceType, int port,
DnsSdRegisterListener listener) {
checkChannel(c);
if (TextUtils.isEmpty(serviceName) || TextUtils.isEmpty(serviceType)) {
throw new IllegalArgumentException("Service name or type cannot be empty");
}
if (port <= 0) {
throw new IllegalArgumentException("Invalid port number");
}
DnsSdServiceInfo serviceInfo = new DnsSdServiceInfo(serviceName, serviceType, null);
serviceInfo.setPort(port);
c.mDnsSdRegisterListener = listener;
c.mAsyncChannel.sendMessage(REGISTER_SERVICE, serviceInfo);
}
/**
* Unregister a service registered through {@link #registerService}
* @param c is the channel created at {@link #initialize}
* @param registeredId is obtained at {@link DnsSdRegisterListener#onServiceRegistered}
* @param listener provides callbacks for success or failure. Can be null.
*/
public void unregisterService(Channel c, int registeredId, ActionListener listener) {
checkChannel(c);
c.mDnsSdUnregisterListener = listener;
c.mAsyncChannel.sendMessage(UNREGISTER_SERVICE, registeredId);
}
/** @hide */
public void updateService(Channel c, int registeredId, DnsSdTxtRecord txtRecord) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
checkChannel(c);
c.mAsyncChannel.sendMessage(UPDATE_SERVICE, registeredId, 0, txtRecord);
}
public void discoverServices(Channel c, String serviceType) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
if (c.mDnsSdDiscoveryListener == null) throw new
IllegalStateException("Discovery listener needs to be set first");
/**
* Initiate service discovery to browse for instances of a service type. Service discovery
* consumes network bandwidth and will continue until the application calls
* {@link #stopServiceDiscovery}.
*
* <p> The function call immediately returns after sending a request to start service
* discovery to the framework. The application is notified of a success to initiate
* discovery through the callback {@link DnsSdDiscoveryListener#onStarted} or a failure
* through {@link DnsSdDiscoveryListener#onFailure}.
*
* <p> Upon successful start, application is notified when a service is found with
* {@link DnsSdDiscoveryListener#onServiceFound} or when a service is lost with
* {@link DnsSdDiscoveryListener#onServiceLost}.
*
* <p> Upon failure to start, service discovery is not active and application does
* not need to invoke {@link #stopServiceDiscovery}
*
* @param c is the channel created at {@link #initialize}
* @param serviceType The service type being discovered. Examples include "_http._tcp" for
* http services or "_ipp._tcp" for printers
* @param listener provides callbacks when service is found or lost. Cannot be null.
*/
public void discoverServices(Channel c, String serviceType, DnsSdDiscoveryListener listener) {
checkChannel(c);
if (listener == null) {
throw new IllegalStateException("Discovery listener needs to be set first");
}
if (TextUtils.isEmpty(serviceType)) {
throw new IllegalStateException("Service type cannot be empty");
}
DnsSdServiceInfo s = new DnsSdServiceInfo();
s.setServiceType(serviceType);
c.mDnsSdDiscoveryListener = listener;
c.mAsyncChannel.sendMessage(DISCOVER_SERVICES, s);
}
public void stopServiceDiscovery(Channel c) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
/**
* Stop service discovery initiated with {@link #discoverServices}. An active service
* discovery is notified to the application with {@link DnsSdDiscoveryListener#onStarted}
* and it stays active until the application invokes a stop service discovery.
*
* <p> Upon failure to start service discovery notified through
* {@link DnsSdDiscoveryListener#onFailure} service discovery is not active and
* application does not need to stop it.
*
* @param c is the channel created at {@link #initialize}
* @param listener notifies success or failure. Can be null.
*/
public void stopServiceDiscovery(Channel c, ActionListener listener) {
checkChannel(c);
c.mDnsSdStopDiscoveryListener = listener;
c.mAsyncChannel.sendMessage(STOP_DISCOVERY);
}
public void resolveService(Channel c, DnsSdServiceInfo serviceInfo) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
if (serviceInfo == null) throw new IllegalArgumentException("Null serviceInfo");
if (c.mDnsSdResolveListener == null) throw new
IllegalStateException("Resolve listener needs to be set first");
/**
* Resolve a discovered service. An application can resolve a service right before
* establishing a connection to fetch the IP and port details on which to setup
* the connection.
*
* @param c is the channel created at {@link #initialize}
* @param serviceName of the the service
* @param serviceType of the service
* @param listener to receive callback upon success or failure. Cannot be null.
*/
public void resolveService(Channel c, String serviceName, String serviceType,
DnsSdResolveListener listener) {
checkChannel(c);
if (TextUtils.isEmpty(serviceName) || TextUtils.isEmpty(serviceType)) {
throw new IllegalArgumentException("Service name or type cannot be empty");
}
if (listener == null) throw new
IllegalStateException("Resolve listener cannot be null");
c.mDnsSdResolveListener = listener;
DnsSdServiceInfo serviceInfo = new DnsSdServiceInfo(serviceName, serviceType, null);
c.mAsyncChannel.sendMessage(RESOLVE_SERVICE, serviceInfo);
}
/** @hide */
public void stopServiceResolve(Channel c) {
if (c == null) throw new IllegalArgumentException("Channel needs to be initialized");
checkChannel(c);
if (c.mDnsSdResolveListener == null) throw new
IllegalStateException("Resolve listener needs to be set first");
c.mAsyncChannel.sendMessage(STOP_RESOLVE);

14
services/java/com/android/server/NsdService.java
View File

@@ -167,6 +167,18 @@ public class NsdService extends INsdManager.Stub {
NsdManager.ERROR);
}
break;
case NsdManager.UNREGISTER_SERVICE:
if (DBG) Slog.d(TAG, "unregister service");
clientInfo = mClients.get(msg.replyTo);
int regId = msg.arg1;
if (clientInfo.mRegisteredIds.remove(new Integer(regId)) &&
unregisterService(regId)) {
mReplyChannel.replyToMessage(msg, NsdManager.UNREGISTER_SERVICE_SUCCEEDED);
} else {
mReplyChannel.replyToMessage(msg, NsdManager.UNREGISTER_SERVICE_FAILED,
NsdManager.ERROR);
}
break;
case NsdManager.UPDATE_SERVICE:
if (DBG) Slog.d(TAG, "Update service");
//TODO: implement
@@ -237,6 +249,8 @@ public class NsdService extends INsdManager.Stub {
}
public Messenger getMessenger() {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.INTERNET,
"NsdService");
return new Messenger(mAsyncServiceHandler);
}