Merge pull request #1691 from G10h4ck/fixup_brodcastdiscovery

Fix some bugs in broadcast discovery

libretroshare/src/retroshare/rsbroadcastdiscovery.h

@@ -107,5 +107,45 @@ public:
 	 */
 	virtual std::vector<RsBroadcastDiscoveryResult> getDiscoveredPeers() = 0;
 
+	/**
+	 * @brief Check if multicast listening is enabled
+	 * @jsonapi{development}
+	 * On some platforms such as Android multicast listening, which is needed
+	 * for broadcast discovery, is not enabled by default at WiFi driver level
+	 * @see enableMulticastListening, so this method check if it is enabled.
+	 * On platforms that are not expected to have such a limitation this method
+	 * always return true.
+	 * @return true if enabled, false otherwise.
+	 */
+	virtual bool isMulticastListeningEnabled() = 0;
+
+	/**
+	 * @brief On platforms that need it enable low level multicast listening
+	 * @jsonapi{development}
+	 * On Android and potencially other mobile platforms, WiFi drivers are
+	 * configured by default to discard any packet that is not directed to the
+	 * unicast mac address of the interface, this way they could save some
+	 * battery but breaks anything that is not unicast, such as broadcast
+	 * discovery. On such platforms this method enable low level multicast
+	 * listening so we can receive advertisement from same broadcast domain
+	 * nodes.
+	 * On platforms without such limitation does nothing and always return
+	 * false.
+	 * It is exposed as a public API so the UI can decide the right equilibrium
+	 * between discoverability and battery saving.
+	 * @return true if multicast listening has been enabled due to this call,
+	 *	false otherwise.
+	 */
+	virtual bool enableMulticastListening() = 0;
+
+	/**
+	 * @brief Disable multicast listening
+	 * @jsonapi{development}
+	 * The opposite of @see enableMulticastListening.
+	 * @return true if multicast listening has been disabled due to this call,
+	 *	false otherwise.
+	 */
+	virtual bool disableMulticastListening() = 0;
+
 	virtual ~RsBroadcastDiscovery();
 };

libretroshare/src/services/broadcastdiscoveryservice.cc

@@ -25,6 +25,10 @@
 #include <vector>
 #include <iostream>
 
+#ifdef __ANDROID__
+#	include <QtAndroid>
+#endif // def __ANDROID__
+
 #include "services/broadcastdiscoveryservice.h"
 #include "retroshare/rspeers.h"
 #include "serialiser/rsserializable.h"
@@ -94,6 +98,12 @@ BroadcastDiscoveryService::BroadcastDiscoveryService(
 {
 	if(mRsPeers.isHiddenNode(mRsPeers.getOwnId())) return;
 
+#ifdef __ANDROID__
+	createMulticastLock();
+#endif // def __ANDROID__
+
+	enableMulticastListening();
+
 	mUdcParameters.set_can_discover(true);
 	mUdcParameters.set_can_be_discovered(true);
 	mUdcParameters.set_port(port);
@@ -104,7 +114,10 @@ BroadcastDiscoveryService::BroadcastDiscoveryService(
 }
 
 BroadcastDiscoveryService::~BroadcastDiscoveryService()
-{ mUdcPeer.Stop(true); }
+{
+	mUdcPeer.Stop(true);
+	disableMulticastListening();
+}
 
 std::vector<RsBroadcastDiscoveryResult>
 BroadcastDiscoveryService::getDiscoveredPeers()
@@ -192,6 +205,7 @@ RsBroadcastDiscoveryResult BroadcastDiscoveryService::createResult(
 	        BroadcastDiscoveryPack::fromSerializedString(uData);
 
 	RsBroadcastDiscoveryResult rbdr;
+	rbdr.mPgpFingerprint = bdp.mPgpFingerprint;
 	rbdr.mSslId = bdp.mSslId;
 	rbdr.mProfileName = bdp.mProfileName;
 	rbdr.mLocator.
@@ -202,6 +216,95 @@ RsBroadcastDiscoveryResult BroadcastDiscoveryService::createResult(
 	return rbdr;
 }
 
+bool BroadcastDiscoveryService::isMulticastListeningEnabled()
+{
+#ifdef __ANDROID__
+	return assertMulticastLockIsvalid() &&
+	        mWifiMulticastLock.callMethod<jboolean>("isHeld");
+#endif // def __ANDROID__
+
+	return true;
+}
+
+bool BroadcastDiscoveryService::enableMulticastListening()
+{
+#ifdef __ANDROID__
+	if(assertMulticastLockIsvalid() && !isMulticastListeningEnabled())
+	{
+		mWifiMulticastLock.callMethod<void>("acquire");
+		return true;
+	}
+#endif // def __ANDROID__
+
+	return false;
+}
+
+bool BroadcastDiscoveryService::disableMulticastListening()
+{
+#ifdef __ANDROID__
+	if(assertMulticastLockIsvalid() && isMulticastListeningEnabled())
+	{
+		mWifiMulticastLock.callMethod<void>("release");
+		return true;
+	}
+#endif // def __ANDROID__
+
+	return false;
+}
+
+#ifdef __ANDROID__
+bool BroadcastDiscoveryService::createMulticastLock()
+{
+	Dbg2() << __PRETTY_FUNCTION__ << std::endl;
+
+	constexpr auto fname = __PRETTY_FUNCTION__;
+	const auto failure = [&](const std::string& err)
+	{
+		RsErr() << fname << " " << err << std::endl;
+		return false;
+	};
+
+	if(mWifiMulticastLock.isValid())
+		return failure("mWifiMulticastLock is already initialized");
+
+	QAndroidJniObject context = QtAndroid::androidContext();
+	if(!context.isValid())
+		return failure("Cannot retrieve Android context");
+
+	QAndroidJniObject WIFI_SERVICE = QAndroidJniObject::getStaticObjectField(
+	            "android.content.Context", "WIFI_SERVICE", "Ljava/lang/String;");
+	if(!WIFI_SERVICE.isValid())
+		return failure("Cannot retrieve Context.WIFI_SERVICE value");
+
+	QAndroidJniObject wifiManager = context.callObjectMethod(
+	            "getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;",
+	            WIFI_SERVICE.object<jstring>() );
+	if(!wifiManager.isValid())
+		return failure("Cannot retrieve Android Wifi Manager");
+
+	mWifiMulticastLock = wifiManager.callObjectMethod(
+	            "createMulticastLock",
+	            "(Ljava/lang/String;)Landroid/net/wifi/WifiManager$MulticastLock;",
+	            QAndroidJniObject::fromString(fname).object<jstring>() );
+	if(!mWifiMulticastLock.isValid())
+		return failure("Cannot create WifiManager.MulticastLock");
+
+	return true;
+}
+
+bool BroadcastDiscoveryService::assertMulticastLockIsvalid()
+{
+	if(!mWifiMulticastLock.isValid())
+	{
+		RsErr() << __PRETTY_FUNCTION__ << " mWifiMulticastLock is invalid!"
+		        << std::endl;
+		print_stacktrace();
+		return false;
+	}
+	return true;
+}
+#endif // def __ANDROID__
+
 RsBroadcastDiscovery::~RsBroadcastDiscovery() = default;
 RsBroadcastDiscoveryResult::~RsBroadcastDiscoveryResult() = default;
 RsBroadcastDiscoveryPeerFoundEvent::~RsBroadcastDiscoveryPeerFoundEvent() = default;

libretroshare/src/services/broadcastdiscoveryservice.h

@@ -27,8 +27,13 @@
 
 #include <udp_discovery_peer.hpp>
 
+#ifdef __ANDROID__
+#	include <QtAndroidExtras/QAndroidJniObject>
+#endif // def __ANDROID__
+
 #include "retroshare/rsbroadcastdiscovery.h"
 #include "util/rsthreads.h"
+#include "util/rsdebug.h"
 
 namespace UDC = udpdiscovery;
 class RsPeers;
@@ -37,13 +42,21 @@ class BroadcastDiscoveryService :
         public RsBroadcastDiscovery, public RsTickingThread
 {
 public:
-	// TODO: std::shared_ptr<RsPeers> mRsPeers;
 	BroadcastDiscoveryService(RsPeers& pRsPeers);
-	virtual ~BroadcastDiscoveryService() override;
+	~BroadcastDiscoveryService() override;
 
 	/// @see RsBroadcastDiscovery
 	std::vector<RsBroadcastDiscoveryResult> getDiscoveredPeers() override;
 
+	/// @see RsBroadcastDiscovery
+	bool isMulticastListeningEnabled() override;
+
+	/// @see RsBroadcastDiscovery
+	bool enableMulticastListening() override;
+
+	/// @see RsBroadcastDiscovery
+	bool disableMulticastListening() override;
+
 	/// @see RsTickingThread
 	void data_tick() override;
 
@@ -63,4 +76,22 @@ protected:
 
 	RsBroadcastDiscoveryResult createResult(
 	        const UDC::IpPort& ipp, const std::string& uData );
+
+#ifdef __ANDROID__
+	/** Android WifiManager.MulticastLock */
+	QAndroidJniObject mWifiMulticastLock;
+
+	/** Initialize the wifi multicast lock without acquiring it
+	 * Needed to enable multicast listening in Android, for RetroShare broadcast
+	 * discovery inspired by:
+	 * https://github.com/flutter/flutter/issues/16335#issuecomment-420547860
+	 */
+	bool createMulticastLock();
+
+	/** Return false if mWifiMulticastLock is invalid and print error messages */
+	bool assertMulticastLockIsvalid();
+
+#endif // def __ANDROID__
+
+	RS_SET_CONTEXT_DEBUG_LEVEL(3)
 };

retroshare-service/src/android/AndroidManifest.xml

@@ -85,4 +85,8 @@
     <!-- Added by G10h4ck: Needed permission for network usage -->
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <!-- Added by G10h4ck: Needed to listen for multicast packets, needed for
+     !   broadcast discovery -->
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
 </manifest>