dns: add a getaddrinfo based system resolver (#22080)

This can be used when using the system resolver is desired. For
example, on Android.

Signed-off-by: Matt Klein <mklein@lyft.com>

Mirrored from https://github.com/envoyproxy/envoy @ 516b3f304bccf451691224c71a357f9c62840b2b

BUILD

@@ -238,6 +238,7 @@ proto_library(
         "//envoy/extensions/matching/input_matchers/ip/v3:pkg",
         "//envoy/extensions/network/dns_resolver/apple/v3:pkg",
         "//envoy/extensions/network/dns_resolver/cares/v3:pkg",
+        "//envoy/extensions/network/dns_resolver/getaddrinfo/v3:pkg",
         "//envoy/extensions/network/socket_interface/v3:pkg",
         "//envoy/extensions/quic/crypto_stream/v3:pkg",
         "//envoy/extensions/quic/proof_source/v3:pkg",

envoy/extensions/network/dns_resolver/getaddrinfo/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/network/dns_resolver/getaddrinfo/v3/getaddrinfo_dns_resolver.proto

@@ -0,0 +1,30 @@
+syntax = "proto3";
+
+package envoy.extensions.network.dns_resolver.getaddrinfo.v3;
+
+import "udpa/annotations/status.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.network.dns_resolver.getaddrinfo.v3";
+option java_outer_classname = "GetaddrinfoDnsResolverProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/network/dns_resolver/getaddrinfo/v3;getaddrinfov3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: getaddrinfo DNS resolver]
+// [#extension: envoy.network.dns_resolver.getaddrinfo]
+
+// Configuration for getaddrinfo DNS resolver. This resolver will use the system's getaddrinfo()
+// function to resolve hosts.
+//
+// .. attention::
+//
+//   This resolver uses a single background thread to do resolutions. As such, it is not currently
+//   advised for use in situations requiring a high resolution rate. A thread pool can be added
+//   in the future if needed.
+//
+// .. attention::
+//
+//   Resolutions currently use a hard coded TTL of 60s because the getaddrinfo() API does not
+//   provide the actual TTL. Configuration for this can be added in the future if needed.
+message GetAddrInfoDnsResolverConfig {
+}

versioning/BUILD

@@ -180,6 +180,7 @@ proto_library(
         "//envoy/extensions/matching/input_matchers/ip/v3:pkg",
         "//envoy/extensions/network/dns_resolver/apple/v3:pkg",
         "//envoy/extensions/network/dns_resolver/cares/v3:pkg",
+        "//envoy/extensions/network/dns_resolver/getaddrinfo/v3:pkg",
         "//envoy/extensions/network/socket_interface/v3:pkg",
         "//envoy/extensions/quic/crypto_stream/v3:pkg",
         "//envoy/extensions/quic/proof_source/v3:pkg",