conn_pool: making TCP upstreams pluggable (#13548)

Risk Level: Medium (some refactory)
Testing: existing tests pass
Docs Changes: n/a
Release Notes: n/a
Fixes #13185

Signed-off-by: Alyssa Wilk <alyssar@chromium.org>

Mirrored from https://github.com/envoyproxy/envoy @ 6a044a38b762214950aea40fcd0709cd7dccdc44

BUILD

@@ -247,6 +247,7 @@ proto_library(
         "//envoy/extensions/upstreams/http/generic/v3:pkg",
         "//envoy/extensions/upstreams/http/http/v3:pkg",
         "//envoy/extensions/upstreams/http/tcp/v3:pkg",
+        "//envoy/extensions/upstreams/tcp/generic/v3:pkg",
         "//envoy/extensions/wasm/v3:pkg",
         "//envoy/extensions/watchdog/profile_action/v3alpha:pkg",
         "//envoy/service/accesslog/v3:pkg",

envoy/extensions/upstreams/tcp/generic/v3/BUILD

@@ -0,0 +1,9 @@
+# DO NOT EDIT. This file is generated by tools/proto_format/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"],
+)

envoy/extensions/upstreams/tcp/generic/v3/generic_connection_pool.proto

@@ -0,0 +1,18 @@
+syntax = "proto3";
+
+package envoy.extensions.upstreams.tcp.generic.v3;
+
+import "udpa/annotations/status.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.upstreams.tcp.generic.v3";
+option java_outer_classname = "GenericConnectionPoolProtoOuterClass";
+option java_multiple_files = true;
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: Generic Connection Pool]
+
+// A connection pool which forwards downstream TCP as TCP or HTTP to upstream,
+// based on CONNECT configuration.
+// [#extension: envoy.upstreams.tcp.generic]
+message GenericConnectionPoolProto {
+}

versioning/BUILD

@@ -130,6 +130,7 @@ proto_library(
         "//envoy/extensions/upstreams/http/generic/v3:pkg",
         "//envoy/extensions/upstreams/http/http/v3:pkg",
         "//envoy/extensions/upstreams/http/tcp/v3:pkg",
+        "//envoy/extensions/upstreams/tcp/generic/v3:pkg",
         "//envoy/extensions/wasm/v3:pkg",
         "//envoy/extensions/watchdog/profile_action/v3alpha:pkg",
         "//envoy/service/accesslog/v3:pkg",