Bluez DBus peripheral add support for extended properties

Task-number: QTBUG-107511
Change-Id: Ia94262a29457489f8b7d5ffd2f5b50f943eb4b21
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

3 files changed, 34 insertions, 8 deletions

diff --git a/src/bluetooth/bluez/bluezperipheralapplication.cpp b/src/bluetooth/bluez/bluezperipheralapplication.cpp
index 0da243e4..5a8e4899 100644
--- a/src/bluetooth/bluez/bluezperipheralapplication.cpp
+++ b/src/bluetooth/bluez/bluezperipheralapplication.cpp
@@ -180,9 +180,13 @@ void QtBluezPeripheralApplication::addService(const QLowEnergyServiceData &servi
         quint16 descriptorOrdinal{0};
         for (const auto& descriptorData : characteristicData.descriptors()) {
             // With bluez we don't use the CCCD user has provided, because Bluez
-            // generates it if 'notify/indicate' flag is set. Duplicate CCCDs would ensue
+            // generates it if 'notify/indicate' flag is set. Similarly the extended properties
+            // descriptor is generated by Bluez if the related flags are set. Using the application
+            // provided descriptors would result in duplicate descriptors.
             if (descriptorData.uuid()
-                    == QBluetoothUuid::DescriptorType::ClientCharacteristicConfiguration) {
+                    == QBluetoothUuid::DescriptorType::ClientCharacteristicConfiguration
+                    || descriptorData.uuid()
+                    == QBluetoothUuid::DescriptorType::CharacteristicExtendedProperties) {
                 continue;
             }
             auto descriptorHandle = handleForDescriptor(descriptorData.uuid(),
diff --git a/src/bluetooth/bluez/bluezperipheralobjects.cpp b/src/bluetooth/bluez/bluezperipheralobjects.cpp
index 090005ab..877b17ca 100644
--- a/src/bluetooth/bluez/bluezperipheralobjects.cpp
+++ b/src/bluetooth/bluez/bluezperipheralobjects.cpp
@@ -280,11 +280,24 @@ void QtBluezPeripheralCharacteristic::initializeFlags(const QLowEnergyCharacteri
         m_flags.append("indicate"_L1);
     if (data.properties() & QLowEnergyCharacteristic::PropertyType::WriteSigned)
         m_flags.append("authenticated-signed-writes"_L1);
-    // TODO how to interpet ExtendedProperty? (reliable-write and writable-auxiliaries?)
-    // (Note: Bluez will generate any needed special descriptors). Also: check
-    // the secure-read and secure-write flags
-    if (data.properties() & QLowEnergyCharacteristic::PropertyType::ExtendedProperty)
-        m_flags.append("extended-properties"_L1);
+    if (data.properties() & QLowEnergyCharacteristic::PropertyType::ExtendedProperty) {
+        // If extended properties property is set, check if we have the descriptor
+        // describing them. Bluez will generate the actual descriptor based on these
+        // flags. For clarity: the 'extended-properties' token mentioned in the Bluez
+        // API is implied by these flags.
+        for (const auto& descriptor : data.descriptors()) {
+            // Core Bluetooth v5.3 Vol 3, Part G, 3.3.3.1
+            if (descriptor.uuid()
+                    == QBluetoothUuid::DescriptorType::CharacteristicExtendedProperties
+                    && descriptor.value().size() == 2) {
+                const auto properties = descriptor.value().at(0);
+                if (properties & 0x01)
+                    m_flags.append("reliable-write"_L1);
+                if (properties & 0x02)
+                    m_flags.append("writable-auxiliaries"_L1);
+            }
+        }
+    }
 
     if (data.readConstraints() & QBluetooth::AttAccessConstraint::AttEncryptionRequired)
         m_flags.append("encrypt-read"_L1);
diff --git a/tests/bttestui/btlocaldevice.cpp b/tests/bttestui/btlocaldevice.cpp
index 9306c482..b0c55ca7 100644
--- a/tests/bttestui/btlocaldevice.cpp
+++ b/tests/bttestui/btlocaldevice.cpp
@@ -957,7 +957,8 @@ void BtLocalDevice::peripheralAddServices()
             charData.setValueLength(leCharacteristicSize, leCharacteristicSize);
             charData.setProperties(QLowEnergyCharacteristic::PropertyType::Read
                                    | QLowEnergyCharacteristic::PropertyType::Write
-                                   | QLowEnergyCharacteristic::PropertyType::Notify);
+                                   | QLowEnergyCharacteristic::PropertyType::Notify
+                                   | QLowEnergyCharacteristic::ExtendedProperty);
 
             const QLowEnergyDescriptorData clientConfig(
                     QBluetoothUuid::DescriptorType::ClientCharacteristicConfiguration,
@@ -968,6 +969,14 @@ void BtLocalDevice::peripheralAddServices()
                         QBluetoothUuid::DescriptorType::CharacteristicUserDescription,
                         leDescriptorValue);
             charData.addDescriptor(userDescription);
+
+            const QLowEnergyDescriptorData extendedProperties(
+                        QBluetoothUuid::DescriptorType::CharacteristicExtendedProperties,
+                        // From bluetooth specs: length 2 bytes
+                        // bit 0: reliable write, bit 1: writable auxiliaries
+                        QByteArray::fromHex("0300"));
+            charData.addDescriptor(extendedProperties);
+
             sd.addCharacteristic(charData);
 
             // Set another characteristic without notifications