network: add socket interface factory and config option

api/BUILD

@@ -227,6 +227,7 @@ proto_library(
         "//envoy/extensions/internal_redirect/allow_listed_routes/v3:pkg",
         "//envoy/extensions/internal_redirect/previous_routes/v3:pkg",
         "//envoy/extensions/internal_redirect/safe_cross_scheme/v3:pkg",
+        "//envoy/extensions/network/socket_interface/v3:pkg",
         "//envoy/extensions/retry/host/omit_host_metadata/v3:pkg",
         "//envoy/extensions/retry/priority/previous_priorities/v3:pkg",
         "//envoy/extensions/transport_sockets/alts/v3:pkg",

api/envoy/config/bootstrap/v3/bootstrap.proto

@@ -39,7 +39,7 @@ option (udpa.annotations.file_status).package_version_status = ACTIVE;
 // <config_overview_bootstrap>` for more detail.
 
 // Bootstrap :ref:`configuration overview <config_overview_bootstrap>`.
-// [#next-free-field: 24]
+// [#next-free-field: 25]
 message Bootstrap {
   option (udpa.annotations.versioning).previous_message_type =
       "envoy.config.bootstrap.v2.Bootstrap";
@@ -222,6 +222,10 @@ message Bootstrap {
   // other resolution fails.
   // [#not-implemented-hide:]
   core.v3.ConfigSource default_config_source = 23;
+
+  // Optional overriding of default socket interface. The value must be the name of one of the
+  // socket interface factories initialized through a bootstrap extension
+  string default_socket_interface = 24;
 }
 
 // Administration interface :ref:`operations documentation

api/envoy/extensions/network/socket_interface/v3/BUILD

@@ -0,0 +1,9 @@
+# DO NOT EDIT. This file is generated by tools/proto_sync.py.
+
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
+
+licenses(["notice"])  # Apache 2
+
+api_proto_package(
+    deps = ["@com_github_cncf_udpa//udpa/annotations:pkg"],
+)

api/envoy/extensions/network/socket_interface/v3/default_socket_interface.proto

@@ -0,0 +1,17 @@
+syntax = "proto3";
+
+package envoy.extensions.network.socket_interface.v3;
+
+import "udpa/annotations/status.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.network.socket_interface.v3";
+option java_outer_classname = "DefaultSocketInterfaceProto";
+option java_multiple_files = true;
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Default Socket Interface configuration]
+
+// Configuration for default socket interface that relies on OS dependent syscall to create
+// sockets.
+message DefaultSocketInterface {
+}

api/versioning/BUILD

@@ -110,6 +110,7 @@ proto_library(
         "//envoy/extensions/internal_redirect/allow_listed_routes/v3:pkg",
         "//envoy/extensions/internal_redirect/previous_routes/v3:pkg",
         "//envoy/extensions/internal_redirect/safe_cross_scheme/v3:pkg",
+        "//envoy/extensions/network/socket_interface/v3:pkg",
         "//envoy/extensions/retry/host/omit_host_metadata/v3:pkg",
         "//envoy/extensions/retry/priority/previous_priorities/v3:pkg",
         "//envoy/extensions/transport_sockets/alts/v3:pkg",

docs/root/api-v3/common_messages/common_messages.rst

@@ -20,3 +20,4 @@ Common messages
   ../config/core/v3/substitution_format_string.proto
   ../extensions/common/ratelimit/v3/ratelimit.proto
   ../extensions/filters/common/fault/v3/fault.proto
+  ../extensions/network/socket_interface/v3/default_socket_interface.proto

include/envoy/network/BUILD

@@ -96,6 +96,7 @@ envoy_cc_library(
     deps = [
         ":address_interface",
         ":io_handle_interface",
+        "//include/envoy/config:typed_config_interface",
         "@envoy_api//envoy/config/core/v3:pkg_cc_proto",
     ],
 )

include/envoy/network/socket.h

@@ -271,5 +271,7 @@ class SocketInterface {
   virtual bool ipFamilySupported(int domain) PURE;
 };
 
+using SocketInterfacePtr = std::unique_ptr<SocketInterface>;
+
 } // namespace Network
 } // namespace Envoy

source/common/network/BUILD

@@ -17,10 +17,10 @@ envoy_cc_library(
     hdrs = [
         "address_impl.h",
         "io_socket_handle_impl.h",
-        "socket_interface_impl.h",
     ],
     deps = [
         ":io_socket_error_lib",
+        ":socket_interface_lib",
         "//include/envoy/buffer:buffer_interface",
         "//include/envoy/network:address_interface",
         "//include/envoy/network:io_handle_interface",
@@ -172,6 +172,17 @@ envoy_cc_library(
     ],
 )
 
+envoy_cc_library(
+    name = "socket_interface_lib",
+    hdrs = ["socket_interface.h"],
+    deps = [
+        "//include/envoy/config:typed_config_interface",
+        "//include/envoy/network:socket_interface",
+        "//include/envoy/registry",
+        "//include/envoy/server:bootstrap_extension_config_interface",
+    ],
+)
+
 envoy_cc_library(
     name = "socket_lib",
     srcs = [
@@ -184,10 +195,11 @@ envoy_cc_library(
     ],
     deps = [
         ":address_lib",
+        ":socket_interface_lib",
         "//include/envoy/network:socket_interface",
         "//source/common/common:assert_lib",
         "//source/common/common:utility_lib",
-        "//source/common/singleton:threadsafe_singleton",
+        "@envoy_api//envoy/extensions/network/socket_interface/v3:pkg_cc_proto",
     ],
 )
 

source/common/network/address_impl.cc

@@ -10,7 +10,7 @@
 #include "common/common/assert.h"
 #include "common/common/fmt.h"
 #include "common/common/utility.h"
-#include "common/network/socket_interface_impl.h"
+#include "common/network/socket_interface.h"
 
 namespace Envoy {
 namespace Network {

source/common/network/socket_interface.h

@@ -0,0 +1,56 @@
+#pragma once
+
+#include "envoy/config/typed_config.h"
+#include "envoy/network/socket.h"
+#include "envoy/registry/registry.h"
+#include "envoy/server/bootstrap_extension_config.h"
+
+#include "common/singleton/threadsafe_singleton.h"
+
+#include "absl/container/flat_hash_map.h"
+
+namespace Envoy {
+namespace Network {
+
+// Wrapper for SocketInterface instances returned by createBootstrapExtension() which must be
+// implemented by all factories that derive SocketInterfaceBase
+class SocketInterfaceExtension : public Server::BootstrapExtension {
+public:
+  SocketInterfaceExtension(SocketInterface& sock_interface) : sock_interface_(sock_interface) {}
+  SocketInterface& socketInterface() { return sock_interface_; }
+
+private:
+  SocketInterface& sock_interface_;
+};
+
+// Class to be derived by all SocketInterface implementations.
+//
+// It acts both as a SocketInterface and as a BootstrapExtensionFactory. The latter is used, on the
+// one hand, to configure and initialize the interface and, on the other, for SocketInterface lookup
+// by leveraging the FactoryRegistry. As required for all bootstrap extensions, all derived classes
+// should register via the REGISTER_FACTORY() macro as BootstrapExtensionFactory.
+//
+// SocketInterface instances can be retrieved using the factory name, i.e., string returned by
+// name() function implemented by all classes that derive SocketInterfaceBase, via
+// Network::socketInterface(). When instantiating addresses, address resolvers should
+// set the socket interface field to the name of the socket interface implementation that should
+// be used to create sockets for said addresses.
+class SocketInterfaceBase : public SocketInterface,
+                            public Server::Configuration::BootstrapExtensionFactory {};
+
+/**
+ * Lookup SocketInterface instance by name
+ * @param name Name of the socket interface to be looked up
+ * @return Pointer to @ref SocketInterface instance that registered using the name of nullptr
+ */
+static inline const SocketInterface* socketInterface(std::string name) {
+  auto factory =
+      Registry::FactoryRegistry<Server::Configuration::BootstrapExtensionFactory>::getFactory(name);
+  return dynamic_cast<SocketInterface*>(factory);
+}
+
+using SocketInterfaceSingleton = InjectableSingleton<SocketInterface>;
+using SocketInterfaceLoader = ScopedInjectableLoader<SocketInterface>;
+
+} // namespace Network
+} // namespace Envoy

source/common/network/socket_interface_impl.cc

@@ -1,6 +1,7 @@
 #include "common/network/socket_interface_impl.h"
 
 #include "envoy/common/exception.h"
+#include "envoy/extensions/network/socket_interface/v3/default_socket_interface.pb.h"
 #include "envoy/network/socket.h"
 
 #include "common/api/os_sys_calls_impl.h"
@@ -81,6 +82,19 @@ bool SocketInterfaceImpl::ipFamilySupported(int domain) {
   return SOCKET_VALID(result.rc_);
 }
 
+Server::BootstrapExtensionPtr
+SocketInterfaceImpl::createBootstrapExtension(const Protobuf::Message&,
+                                              Server::Configuration::ServerFactoryContext&) {
+  return std::make_unique<SocketInterfaceExtension>(*this);
+}
+
+ProtobufTypes::MessagePtr SocketInterfaceImpl::createEmptyConfigProto() {
+  return std::make_unique<
+      envoy::extensions::network::socket_interface::v3::DefaultSocketInterface>();
+}
+
+REGISTER_FACTORY(SocketInterfaceImpl, Server::Configuration::BootstrapExtensionFactory);
+
 static SocketInterfaceLoader* socket_interface_ =
     new SocketInterfaceLoader(std::make_unique<SocketInterfaceImpl>());
 

source/common/network/socket_interface_impl.h

@@ -3,22 +3,31 @@
 #include "envoy/network/address.h"
 #include "envoy/network/socket.h"
 
-#include "common/singleton/threadsafe_singleton.h"
+#include "common/network/socket_interface.h"
 
 namespace Envoy {
 namespace Network {
 
-class SocketInterfaceImpl : public SocketInterface {
+class SocketInterfaceImpl : public SocketInterfaceBase {
 public:
+  // SocketInterface
   IoHandlePtr socket(Socket::Type socket_type, Address::Type addr_type,
                      Address::IpVersion version) override;
   IoHandlePtr socket(Socket::Type socket_type, const Address::InstanceConstSharedPtr addr) override;
   IoHandlePtr socket(os_fd_t fd) override;
   bool ipFamilySupported(int domain) override;
+
+  // Server::Configuration::BootstrapExtensionFactory
+  Server::BootstrapExtensionPtr
+  createBootstrapExtension(const Protobuf::Message& config,
+                           Server::Configuration::ServerFactoryContext& context) override;
+  ProtobufTypes::MessagePtr createEmptyConfigProto() override;
+  std::string name() const override {
+    return "envoy.extensions.network.socket_interface.default_socket_interface";
+  };
 };
 
-using SocketInterfaceSingleton = InjectableSingleton<SocketInterface>;
-using SocketInterfaceLoader = ScopedInjectableLoader<SocketInterface>;
+DECLARE_FACTORY(SocketInterfaceImpl);
 
 } // namespace Network
 } // namespace Envoy

source/server/BUILD

@@ -46,6 +46,7 @@ envoy_cc_library(
         "//source/common/config:runtime_utility_lib",
         "//source/common/config:utility_lib",
         "//source/common/network:resolver_lib",
+        "//source/common/network:socket_interface_lib",
         "//source/common/network:socket_option_factory_lib",
         "//source/common/network:utility_lib",
         "//source/common/protobuf:utility_lib",