udp_listener: refactor ActiveUdpListener creation

include/envoy/network/connection_handler.h

@@ -103,6 +103,10 @@ class ActiveUdpListenerFactory {
    * Creates an ActiveUdpListener object and a corresponding UdpListener
    * according to given config.
    * @param parent is the owner of the created ActiveListener objects.
+   * @param dispatcher is used to create actual UDP listener.
+   * @param logger might not need to be passed in.
+   * TODO(danzh): investigate if possible to use statically defined logger in ActiveUdpListener
+   * implementation instead.
    * @param config provides information needed to create ActiveUdpListener and
    * UdpListener objects.
    * @return the ActiveUdpListener created.

source/server/BUILD

@@ -261,6 +261,7 @@ envoy_cc_library(
         ":filter_chain_manager_lib",
         ":lds_api_lib",
         ":transport_socket_config_lib",
+        ":well_known_names_lib",
         "//include/envoy/server:active_udp_listener_config_interface",
         "//include/envoy/server:filter_config_interface",
         "//include/envoy/server:listener_manager_interface",
@@ -443,12 +444,18 @@ envoy_cc_library(
     ],
 )
 
+envoy_cc_library(
+    name = "well_known_names_lib",
+    hdrs = ["well_known_names.h"],
+)
+
 envoy_cc_library(
     name = "active_raw_udp_listener_config",
     srcs = ["active_raw_udp_listener_config.cc"],
     hdrs = ["active_raw_udp_listener_config.h"],
     deps = [
         ":connection_handler_lib",
+        ":well_known_names_lib",
         "//include/envoy/registry",
         "//include/envoy/server:active_udp_listener_config_interface",
     ],

source/server/active_raw_udp_listener_config.cc

@@ -1,6 +1,7 @@
 #include "server/active_raw_udp_listener_config.h"
 
 #include "server/connection_handler_impl.h"
+#include "server/well_known_names.h"
 
 namespace Envoy {
 namespace Server {
@@ -17,7 +18,7 @@ ActiveRawUdpListenerConfigFactory::createActiveUdpListenerFactory(
   return std::make_unique<Server::ActiveRawUdpListenerFactory>();
 }
 
-std::string ActiveRawUdpListenerConfigFactory::name() { return "raw_udp_listener"; }
+std::string ActiveRawUdpListenerConfigFactory::name() { return UdpListenerNames::get().RawUdp; }
 
 REGISTER_FACTORY(ActiveRawUdpListenerConfigFactory, Server::ActiveUdpListenerConfigFactory);
 

source/server/listener_manager_impl.cc

@@ -24,6 +24,7 @@
 #include "server/drain_manager_impl.h"
 #include "server/filter_chain_manager_impl.h"
 #include "server/transport_socket_config_impl.h"
+#include "server/well_known_names.h"
 
 #include "extensions/filters/listener/well_known_names.h"
 #include "extensions/transport_sockets/well_known_names.h"
@@ -230,7 +231,7 @@ ListenerImpl::ListenerImpl(const envoy::api::v2::Listener& config, const std::st
     std::string listener_name =
         config.has_udp_listener_config() ? config.udp_listener_config().udp_listener_name() : "";
     if (listener_name.empty()) {
-      listener_name = "raw_udp_listener";
+      listener_name = UdpListenerNames::get().RawUdp;
     }
     udp_listener_factory_ =
         Config::Utility::getAndCheckFactory<ActiveUdpListenerConfigFactory>(listener_name)

source/server/well_known_names.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <string>
+
+#include "common/singleton/const_singleton.h"
+
+namespace Envoy {
+namespace Server {
+
+/**
+ * Well-known active UDP listener names.
+ */
+class UdpListenerNameValues {
+public:
+  const std::string RawUdp = "raw_udp_listener";
+  const std::string Quic = "quic_listener";
+};
+
+using UdpListenerNames = ConstSingleton<UdpListenerNameValues>;
+
+} // namespace Server
+} // namespace Envoy