lua: add downstreamRemoteAddress() method

changelogs/current.yaml

@@ -212,6 +212,10 @@ new_features:
 - area: extension_discovery_service
   change: |
     added metric listener.listener_stat.network_extension_config_missing to track closed connections due to missing config.
+- area: lua
+  change: |
+    added :ref:`downstreamRemoteAddress() <config_http_filters_lua_stream_info_downstream_remote_address>`
+    method to the Stream info object API.
 - area: quic
   change: |
     added support for QUIC listener filters with ECDS support reusing the same config API

docs/root/configuration/http/http_filters/lua_filter.rst

@@ -791,6 +791,8 @@ downstreamLocalAddress()
 Returns the string representation of :repo:`downstream local address <envoy/stream_info/stream_info.h>`
 used by the current request.
 
+.. _config_http_filters_lua_stream_info_downstream_direct_remote_address:
+
 downstreamDirectRemoteAddress()
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -801,6 +803,19 @@ downstreamDirectRemoteAddress()
 Returns the string representation of :repo:`downstream directly connected address <envoy/stream_info/stream_info.h>`
 used by the current request. This is equivalent to the address of the physical connection.
 
+.. _config_http_filters_lua_stream_info_downstream_remote_address:
+
+downstreamRemoteAddress()
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: lua
+
+  streamInfo:downstreamRemoteAddress()
+
+Returns the string representation of the downstream remote address for the current request. This may differ from
+:ref:`downstreamDirectRemoteAddress() <config_http_filters_lua_stream_info_downstream_direct_remote_address>` depending upon the setting of
+:ref:`xff_num_trusted_hops <envoy_v3_api_field_extensions.filters.network.http_connection_manager.v3.HttpConnectionManager.xff_num_trusted_hops>`.
+
 dynamicMetadata()
 ^^^^^^^^^^^^^^^^^
 

source/extensions/filters/http/lua/wrappers.cc

@@ -199,6 +199,13 @@ int StreamInfoWrapper::luaDownstreamDirectRemoteAddress(lua_State* state) {
   return 1;
 }
 
+int StreamInfoWrapper::luaDownstreamRemoteAddress(lua_State* state) {
+  const std::string& remote_address =
+      stream_info_.downstreamAddressProvider().remoteAddress()->asString();
+  lua_pushlstring(state, remote_address.data(), remote_address.size());
+  return 1;
+}
+
 int StreamInfoWrapper::luaRequestedServerName(lua_State* state) {
   absl::string_view requested_serve_name =
       stream_info_.downstreamAddressProvider().requestedServerName();

source/extensions/filters/http/lua/wrappers.h

@@ -209,6 +209,7 @@ class StreamInfoWrapper : public Filters::Common::Lua::BaseLuaObject<StreamInfoW
             {"dynamicMetadata", static_luaDynamicMetadata},
             {"downstreamLocalAddress", static_luaDownstreamLocalAddress},
             {"downstreamDirectRemoteAddress", static_luaDownstreamDirectRemoteAddress},
+            {"downstreamRemoteAddress", static_luaDownstreamRemoteAddress},
             {"downstreamSslConnection", static_luaDownstreamSslConnection},
             {"requestedServerName", static_luaRequestedServerName}};
   }
@@ -239,12 +240,18 @@ class StreamInfoWrapper : public Filters::Common::Lua::BaseLuaObject<StreamInfoW
   DECLARE_LUA_FUNCTION(StreamInfoWrapper, luaDownstreamLocalAddress);
 
   /**
-   * Get current downstream local address
+   * Get current direct downstream remote address
    * @return string representation of downstream directly connected address.
    * This is equivalent to the address of the physical connection.
    */
   DECLARE_LUA_FUNCTION(StreamInfoWrapper, luaDownstreamDirectRemoteAddress);
 
+  /**
+   * Get current downstream remote address
+   * @return string representation of downstream remote address.
+   */
+  DECLARE_LUA_FUNCTION(StreamInfoWrapper, luaDownstreamRemoteAddress);
+
   /**
    * Get requested server name
    * @return requested server name (e.g. SNI in TLS), if any.

test/extensions/filters/http/lua/lua_integration_test.cc

@@ -311,6 +311,8 @@ name: lua
           request_handle:streamInfo():downstreamLocalAddress())
         request_handle:headers():add("request_downstream_directremote_address_value",
           request_handle:streamInfo():downstreamDirectRemoteAddress())
+        request_handle:headers():add("request_downstream_remote_address_value",
+          request_handle:streamInfo():downstreamRemoteAddress())
         request_handle:headers():add("request_requested_server_name",
           request_handle:streamInfo():requestedServerName())
       end
@@ -420,6 +422,12 @@ name: lua
           .getStringView(),
       GetParam() == Network::Address::IpVersion::v4 ? "127.0.0.1:" : "[::1]:"));
 
+  EXPECT_EQ("10.0.0.1:0",
+            upstream_request_->headers()
+                .get(Http::LowerCaseString("request_downstream_remote_address_value"))[0]
+                ->value()
+                .getStringView());
+
   EXPECT_EQ("", upstream_request_->headers()
                     .get(Http::LowerCaseString("request_requested_server_name"))[0]
                     ->value()

test/extensions/filters/http/lua/wrappers_test.cc

@@ -349,6 +349,7 @@ TEST_F(LuaStreamInfoWrapperTest, ReturnCurrentDownstreamAddresses) {
       function callMe(object)
         testPrint(object:downstreamLocalAddress())
         testPrint(object:downstreamDirectRemoteAddress())
+        testPrint(object:downstreamRemoteAddress())
       end
     )EOF"};
 
@@ -360,13 +361,17 @@ TEST_F(LuaStreamInfoWrapperTest, ReturnCurrentDownstreamAddresses) {
       new Network::Address::Ipv4Instance("127.0.0.1", 8000)};
   auto downstream_direct_remote =
       Network::Address::InstanceConstSharedPtr{new Network::Address::Ipv4Instance("8.8.8.8", 3000)};
+  auto downstream_remote = Network::Address::InstanceConstSharedPtr{
+      new Network::Address::Ipv4Instance("10.1.2.3", 5000)};
   stream_info.downstream_connection_info_provider_->setLocalAddress(address);
   stream_info.downstream_connection_info_provider_->setDirectRemoteAddressForTest(
       downstream_direct_remote);
+  stream_info.downstream_connection_info_provider_->setRemoteAddress(downstream_remote);
   Filters::Common::Lua::LuaDeathRef<StreamInfoWrapper> wrapper(
       StreamInfoWrapper::create(coroutine_->luaState(), stream_info), true);
   EXPECT_CALL(printer_, testPrint(address->asString()));
   EXPECT_CALL(printer_, testPrint(downstream_direct_remote->asString()));
+  EXPECT_CALL(printer_, testPrint(downstream_remote->asString()));
   start("callMe");
   wrapper.reset();
 }