Some hardening for misbehaving apps (e.g. calling connect while scanning)

Author: psychogenic

CMakeLists.txt

@@ -45,7 +45,7 @@ set(CPACK_PACKAGE_INSTALL_DIRECTORY /usr CACHE STRING "Install directory (defaul
 if (ENV{TRAVIS_TAG})
   set(CPACK_PACKAGE_VERSION $ENV{TRAVIS_TAG})
 else()
-  set(CPACK_PACKAGE_VERSION 1.0.2)
+  set(CPACK_PACKAGE_VERSION 1.0.3)
 endif()
 set(CPACK_PACKAGE_CONTACT "Pat Deegan, https://psychogenic.com")
 set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "C++ Wrapper for gattlib, to access GATT information from Bluetooth Low Energy (BLE) devices")

gattlibpp/BLECentral.cpp

@@ -306,11 +306,42 @@ bool BLECentral::scan(SecondsValue runSeconds,
 	BLECENTRAL_ENSURE_ADAPTER_AVAIL(failure);
 
 	if (is_scanning) {
+		/*
+		AsyncAction::Details asyncAlreadyRunningAct("scanrunning", scanCompleted, failure);
+		asyncAlreadyRunningAct.trigger = [](AsyncAction::Details * thisAction) {
+			thisAction->completedWithSuccess();
+		};
 
-		BLECENTRAL_TRIGGER_CB_IFSET(failure, "already scanning");
-		return false;
+		queueAsyncAction(asyncAlreadyRunningAct);
+		*/
+		return true;
 	}
 
+	if (connected_to.size() && ! numAsyncActionsQueued()) {
+		BLECNTL_DEBUGLN("asked to scan but we're connected and there's nothing queued to disconn... do that first");
+
+		Device::Details * dets = deviceDetails(connected_to);
+		if (dets && dets->connection) {
+			// we really seem to be still connected to this thing
+			AsyncAction::Details autoDisconnAction("autodisconn", [](){
+				BLECNTL_DEBUGLN("auto disconn completed");
+			}, [](){
+				BLECNTL_DEBUGLN("hm, auto disconn failed?");
+			});
+
+			UUID devId = dets->id;
+
+			autoDisconnAction.trigger = [this, devId](AsyncAction::Details * thisAction){
+
+				this->disconnect(devId, [](){
+				}, [](){
+				});
+			};
+
+		}
+	}
+
+
 
 	devDiscoveredCb = deviceDiscoveredCb;
 
@@ -320,7 +351,7 @@ bool BLECentral::scan(SecondsValue runSeconds,
 		if (gattlib_adapter_scan_enable_async(adapter, clib_device_discovered_callback,
 				runSeconds, clib_scan_complete_callback) != 0)
 		{
-
+			this->is_scanning = false;
 			thisAction->completedWithFailure();
 		}
 
@@ -329,27 +360,6 @@ bool BLECentral::scan(SecondsValue runSeconds,
 
 	queueAsyncAction(asyncAct);
 
-
-
-#if 0
-	// let's push this onto the queue, because bluez has
-	// a tendency to spit out all the cached deviced immediately,
-	// and we want to ensure that
-	//  a) we're well into 'scanning mode' when the discovered callback triggers, and
-	//  b) we want the discovered cb to alway be called in the same context -- meaning
-	//     if the async processing happens is some thread, then every cb should happen
-	//     in that thread.
-	reportQueue.push_back([runSeconds, this, failure](){
-
-		if (gattlib_adapter_scan_enable_async(adapter, clib_device_discovered_callback,
-				runSeconds, clib_scan_complete_callback) != 0)
-		{
-			BLECENTRAL_TRIGGER_CB_IFSET(failure, "scan enable call failed");
-		}
-
-	});
-#endif
-
 	is_scanning = true;
 	return true;
 }
@@ -381,7 +391,13 @@ bool BLECentral::stopScan(Callbacks::SuccessNotification succ,
 		Callbacks::Error failure) {
 	BLECENTRAL_ENSURE_ADAPTER_AVAIL(failure);
 	if (! is_scanning) {
-		BLECENTRAL_TRIGGER_CB_IFSET(failure, "not currently scanning");
+
+		AsyncAction::Details alreadyDoneAct("stopScanDone", succ, failure);
+		alreadyDoneAct.trigger = [](AsyncAction::Details * thisAction) {
+			thisAction->completedWithSuccess();
+		};
+		queueAsyncAction(alreadyDoneAct);
+		return true;
 	}
 
 	// we are currently scanning, which means we have an async op running
@@ -962,7 +978,7 @@ void BLECentral::deviceDiscovered(const Discovery::Device & dev) {
 
 void BLECentral::scanCompleted() {
 
-	// is_scanning = false;
+	is_scanning = false;
 	currentOpCompleted();
 
 }

include/gattlibpp/BLECentral.h

@@ -442,7 +442,7 @@ class BLECentral {
 	void autoDiscoverServicesStep(Device::Details * onDevice);
 	void autoDiscoverCharacteristicsStep(Device::Details * onDevice);
 	void queueAsyncAction(const AsyncAction::Details & dets);
-
+	inline AsyncActionQueue::size_type numAsyncActionsQueued() { return asyncActions.size(); }
 
 	AdapterPtr adapter;
 	AdapterName adapter_name;