Allow FirmwarePlugin to drop incoming messages

src/FirmwarePlugin/FirmwarePlugin.cc

@@ -93,11 +93,12 @@ int FirmwarePlugin::manualControlReservedButtonCount(void)
     return -1;
 }
 
-void FirmwarePlugin::adjustIncomingMavlinkMessage(Vehicle* vehicle, mavlink_message_t* message)
+bool FirmwarePlugin::adjustIncomingMavlinkMessage(Vehicle* vehicle, mavlink_message_t* message)
 {
     Q_UNUSED(vehicle);
     Q_UNUSED(message);    
     // Generic plugin does no message adjustment
+    return true;
 }
 
 void FirmwarePlugin::adjustOutgoingMavlinkMessage(Vehicle* vehicle, mavlink_message_t* message)

src/FirmwarePlugin/FirmwarePlugin.h

@@ -120,7 +120,8 @@ public:
     /// spec implementations such that the base code can remain mavlink generic.
     ///     @param vehicle Vehicle message came from
     ///     @param message[in,out] Mavlink message to adjust if needed.
-    virtual void adjustIncomingMavlinkMessage(Vehicle* vehicle, mavlink_message_t* message);
+    /// @return false: skip message, true: process message
+    virtual bool adjustIncomingMavlinkMessage(Vehicle* vehicle, mavlink_message_t* message);
     
     /// Called before any mavlink message is sent to the Vehicle so plugin can adjust any message characteristics.
     /// This is handy to adjust or differences in mavlink spec implementations such that the base code can remain

src/Vehicle/Vehicle.cc

@@ -377,7 +377,9 @@ void Vehicle::_mavlinkMessageReceived(LinkInterface* link, mavlink_message_t mes
     }
 
     // Give the plugin a change to adjust the message contents
-    _firmwarePlugin->adjustIncomingMavlinkMessage(this, &message);
+    if (!_firmwarePlugin->adjustIncomingMavlinkMessage(this, &message)) {
+        return;
+    }
 
     switch (message.msgid) {
     case MAVLINK_MSG_ID_HOME_POSITION: