Avoid ABI/API break by adding new private interface

Signed-off-by: Emilio Cuesta <emiliocuesta@eprosima.com>

Author: emiliocuestaf

include/fastdds/rtps/transport/ChainingTransport.hpp

@@ -227,17 +227,6 @@ class ChainingTransport : public TransportInterface
         return low_level_transport_->getDefaultMetatrafficMulticastLocators(locators, metatraffic_multicast_port);
     }
 
-    /**
-     * Call the low-level transport `getDefaultMulticastLocators()`.
-     * Add multicast locator with the given port
-     */
-    FASTDDS_EXPORTED_API bool getDefaultMulticastLocators(
-            fastdds::rtps::LocatorList_t& locators,
-            uint32_t multicast_port) const override
-    {
-        return low_level_transport_->getDefaultMulticastLocators(locators, multicast_port);
-    }
-
     /*!
      * Call the low-level transport `getDefaultMetatrafficUnicastLocators()`.
      * Add metatraffic unicast locator with the given port
@@ -295,17 +284,6 @@ class ChainingTransport : public TransportInterface
         return low_level_transport_->configureInitialPeerLocator(locator, port_params, domainId, list);
     }
 
-    /**
-     * Call the low-level transport `fillMulticastLocator()`.
-     * Assign default values (address and port) to the given multicast locator if not already defined
-     */
-    FASTDDS_EXPORTED_API bool fillMulticastLocator(
-            fastdds::rtps::Locator_t& locator,
-            uint32_t well_known_port) const override
-    {
-        return low_level_transport_->fillMulticastLocator(locator, well_known_port);
-    }
-
     /*!
      * Call the low-level transport `fillUnicastLocator()`.
      * Assign port to the given unicast locator if not already defined

include/fastdds/rtps/transport/TransportInterface.hpp

@@ -245,11 +245,6 @@ class FASTDDS_EXPORTED_API TransportInterface
             LocatorList& locators,
             uint32_t unicast_port) const = 0;
 
-    //! Add multicast locator with the given port
-    virtual bool getDefaultMulticastLocators(
-            LocatorList& locators,
-            uint32_t multicast_port) const = 0;
-
     //! Assign port to the given metatraffic multicast locator if not already defined
     virtual bool fillMetatrafficMulticastLocator(
             Locator& locator,
@@ -276,14 +271,6 @@ class FASTDDS_EXPORTED_API TransportInterface
             Locator& locator,
             uint32_t well_known_port) const = 0;
 
-    /**
-     *  Assign default multicast values to a locator if the transport supports them
-     *  and if they are not already defined.
-     */
-    virtual bool fillMulticastLocator(
-            Locator& locator,
-            uint32_t well_known_port) const = 0;
-
     /**
      * @return The maximum datagram size for reception supported by the transport
      */

src/cpp/rtps/network/NetworkFactory.cpp

@@ -25,6 +25,7 @@
 #include <fastdds/utils/IPLocator.hpp>
 
 #include <rtps/network/NetworkConfiguration.hpp>
+#include <rtps/transport/MulticastTransportInterface.h>
 #include <rtps/transport/TCPTransportInterface.h>
 
 using namespace std;
@@ -495,7 +496,12 @@ bool NetworkFactory::getDefaultMulticastLocators(
     bool result = false;
     for (auto& transport : mRegisteredTransports)
     {
-        result |= transport->getDefaultMulticastLocators(locators, port);
+        const MulticastTransportInterface* multicast_transport =
+                dynamic_cast<const MulticastTransportInterface*>(transport.get());
+        if (multicast_transport)
+        {
+            result |= multicast_transport->getDefaultMulticastLocators(locators, port);
+        }
     }
     return result;
 }
@@ -524,7 +530,12 @@ bool NetworkFactory::fill_default_multicast_locator(
     {
         if (transport->IsLocatorSupported(locator))
         {
-            result |= transport->fillMulticastLocator(locator, port);
+            const MulticastTransportInterface* multicast_transport =
+                    dynamic_cast<const MulticastTransportInterface*>(transport.get());
+            if (multicast_transport)
+            {
+                result |= multicast_transport->fillMulticastLocator(locator, port);
+            }
         }
     }
     return result;

src/cpp/rtps/transport/MulticastTransportInterface.cpp

@@ -0,0 +1,47 @@
+// Copyright 2026 Proyectos y Sistemas de Mantenimiento SL (eProsima).
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <rtps/transport/MulticastTransportInterface.h>
+
+#include <fastdds/utils/IPLocator.hpp>
+
+namespace eprosima {
+namespace fastdds {
+namespace rtps {
+
+bool MulticastTransportInterface::fillMulticastLocator(
+        Locator& locator,
+        uint32_t well_known_port) const
+{
+    LocatorList defaults;
+    getDefaultMulticastLocators(defaults, well_known_port);
+    if (!defaults.empty())
+    {
+        const Locator& default_loc = *defaults.begin();
+        if (locator.port == 0)
+        {
+            locator.port = default_loc.port;
+        }
+        if (!IsAddressDefined(locator))
+        {
+            IPLocator::copy_address(default_loc, locator);
+        }
+    }
+
+    return true;
+}
+
+} // namespace rtps
+} // namespace fastdds
+} // namespace eprosima

src/cpp/rtps/transport/MulticastTransportInterface.h

@@ -0,0 +1,46 @@
+// Copyright 2026 Proyectos y Sistemas de Mantenimiento SL (eProsima).
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef _FASTDDS_MULTICAST_TRANSPORT_INTERFACE_H_
+#define _FASTDDS_MULTICAST_TRANSPORT_INTERFACE_H_
+
+#include <cstdint>
+
+#include <fastdds/rtps/common/Locator.hpp>
+#include <fastdds/rtps/common/LocatorList.hpp>
+
+namespace eprosima {
+namespace fastdds {
+namespace rtps {
+
+class MulticastTransportInterface
+{
+public:
+
+    virtual ~MulticastTransportInterface() = default;
+
+    virtual bool getDefaultMulticastLocators(
+            LocatorList& locators,
+            uint32_t multicast_port) const = 0;
+
+    virtual bool fillMulticastLocator(
+            Locator& locator,
+            uint32_t well_known_port) const;
+};
+
+} // namespace rtps
+} // namespace fastdds
+} // namespace eprosima
+
+#endif // _FASTDDS_MULTICAST_TRANSPORT_INTERFACE_H_

src/cpp/rtps/transport/TCPTransportInterface.cpp

@@ -1693,14 +1693,6 @@ bool TCPTransportInterface::getDefaultMetatrafficMulticastLocators(
     return false;
 }
 
-bool TCPTransportInterface::getDefaultMulticastLocators(
-        LocatorList&,
-        uint32_t ) const
-{
-    // TCP doesn't have multicast support
-    return false;
-}
-
 bool TCPTransportInterface::getDefaultMetatrafficUnicastLocators(
         LocatorList& locators,
         uint32_t metatraffic_unicast_port) const
@@ -1733,14 +1725,6 @@ bool TCPTransportInterface::fillMetatrafficMulticastLocator(
     return false;
 }
 
-bool TCPTransportInterface::fillMulticastLocator(
-        Locator&,
-        uint32_t) const
-{
-    // TCP doesn't have multicast support
-    return false;
-}
-
 bool TCPTransportInterface::fillMetatrafficUnicastLocator(
         Locator& locator,
         uint32_t metatraffic_unicast_port) const

src/cpp/rtps/transport/TCPTransportInterface.h

@@ -468,14 +468,6 @@ class TCPTransportInterface : public TransportInterface
             LocatorList& locators,
             uint32_t unicast_port) const override;
 
-    /**
-     * This method should never be called because TCP interfaces do not support
-     * multicast locators. It always returns false
-     */
-    bool getDefaultMulticastLocators(
-            LocatorList& locators,
-            uint32_t multicast_port) const override;
-
     /**
      * This method should never be called because TCP interfaces do not support
      * multicast locators. It always returns false
@@ -498,14 +490,6 @@ class TCPTransportInterface : public TransportInterface
             Locator& locator,
             uint32_t well_known_port) const override;
 
-    /**
-     * This method should never be called because TCP interfaces do not support
-     * multicast locators. It always returns false
-     */
-    bool fillMulticastLocator(
-            Locator& locator,
-            uint32_t well_known_port) const override;
-
     uint32_t max_recv_buffer_size() const override
     {
         return configuration()->maxMessageSize;

src/cpp/rtps/transport/UDPTransportInterface.cpp

@@ -796,27 +796,6 @@ bool UDPTransportInterface::fillUnicastLocator(
     return true;
 }
 
-bool UDPTransportInterface::fillMulticastLocator(
-        Locator& locator,
-        uint32_t well_known_port) const
-{
-    LocatorList defaults;
-    getDefaultMulticastLocators(defaults, well_known_port);
-    if (!defaults.empty())
-    {
-        const Locator& default_loc = *defaults.begin();
-        if (locator.port == 0)
-        {
-            locator.port = default_loc.port;
-        }
-        if (!IsAddressDefined(locator))
-        {
-            IPLocator::copy_address(default_loc, locator);
-        }
-    }
-    return true;
-}
-
 void UDPTransportInterface::get_unknown_network_interfaces(
         const SendResourceList& sender_resource_list,
         std::vector<IPFinder::info_IP>& locNames,

src/cpp/rtps/transport/UDPTransportInterface.h

@@ -29,14 +29,17 @@
 #include <fastdds/rtps/transport/UDPTransportDescriptor.hpp>
 #include <fastdds/utils/IPFinder.hpp>
 
+#include <rtps/transport/MulticastTransportInterface.h>
 #include <rtps/transport/UDPChannelResource.h>
 #include <statistics/rtps/messages/OutputTrafficManager.hpp>
 
 namespace eprosima {
 namespace fastdds {
 namespace rtps {
 
-class UDPTransportInterface : public TransportInterface
+class UDPTransportInterface
+    : public TransportInterface
+    , public MulticastTransportInterface
 {
     friend class UDPSenderResource;
     friend struct TSN_UDPSender;
@@ -180,18 +183,6 @@ class UDPTransportInterface : public TransportInterface
             uint32_t domainId,
             LocatorList& list) const override;
 
-    /**
-     *  Assign default multicast values to a locator if they are not already defined.
-     *  This means setting both the address and the port to the default multicast
-     *  values for each version of UDP
-     *
-     *  @param locator Locator to be filled with default multicast values if not already defined.
-     *  @param well_known_port Port to be used if the locator port is not already defined.
-     */
-    bool fillMulticastLocator(
-            Locator& locator,
-            uint32_t well_known_port) const override;
-
     bool fillUnicastLocator(
             Locator& locator,
             uint32_t well_known_port) const override;

src/cpp/rtps/transport/shared_mem/SharedMemTransport.cpp

@@ -96,15 +96,6 @@ bool SharedMemTransport::getDefaultMetatrafficUnicastLocators(
     return true;
 }
 
-bool SharedMemTransport::getDefaultMulticastLocators(
-        LocatorList& locators,
-        uint32_t multicast_port) const
-{
-    static_cast<void>(locators);
-    static_cast<void>(multicast_port);
-    return false;
-}
-
 bool SharedMemTransport::getDefaultUnicastLocators(
         LocatorList& locators,
         uint32_t unicast_port) const
@@ -763,15 +754,6 @@ bool SharedMemTransport::fillUnicastLocator(
     return true;
 }
 
-bool SharedMemTransport::fillMulticastLocator(
-        Locator& locator,
-        uint32_t well_known_port) const
-{
-    static_cast<void>(locator);
-    static_cast<void>(well_known_port);
-    return false;
-}
-
 }  // namsepace rtps
 }  // namespace fastdds
 }  // namespace eprosima