Merge pull request #15797 from apolcyn/windows_compile_and_sort

Enable c-ares address sorting on windows

31 files changed, 577 insertions, 73 deletions

diff --git a/BUILD b/BUILD
index ee4b5dfaec..81390dd1aa 100644
--- a/BUILD
+++ b/BUILD
@@ -1433,7 +1433,10 @@ grpc_cc_library(
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc",
     ],
     hdrs = [
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 84e9c08cb5..e8e65d4b71 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -298,6 +298,7 @@ add_dependencies(buildtests_c grpc_completion_queue_test)
 add_dependencies(buildtests_c grpc_completion_queue_threading_test)
 add_dependencies(buildtests_c grpc_credentials_test)
 add_dependencies(buildtests_c grpc_fetch_oauth2)
+add_dependencies(buildtests_c grpc_ipv6_loopback_available_test)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_c grpc_json_token_test)
 endif()
@@ -671,12 +672,8 @@ endif()
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx resolver_component_tests_runner_invoker)
 endif()
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx address_sorting_test_unsecure)
-endif()
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx address_sorting_test)
-endif()
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 add_dependencies(buildtests_cxx cancel_ares_query_test)
 endif()
@@ -1236,8 +1233,11 @@ add_library(grpc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
   src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc
   src/cpp/ext/filters/census/grpc_context.cc
@@ -2538,8 +2538,11 @@ add_library(grpc_unsecure
   src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
+  src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
   src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
   src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc
   src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
@@ -7325,6 +7328,35 @@ target_link_libraries(grpc_fetch_oauth2
 
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
+
+add_executable(grpc_ipv6_loopback_available_test
+  test/core/iomgr/grpc_ipv6_loopback_available_test.cc
+)
+
+
+target_include_directories(grpc_ipv6_loopback_available_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${_gRPC_SSL_INCLUDE_DIR}
+  PRIVATE ${_gRPC_PROTOBUF_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ZLIB_INCLUDE_DIR}
+  PRIVATE ${_gRPC_BENCHMARK_INCLUDE_DIR}
+  PRIVATE ${_gRPC_CARES_INCLUDE_DIR}
+  PRIVATE ${_gRPC_GFLAGS_INCLUDE_DIR}
+  PRIVATE ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+  PRIVATE ${_gRPC_NANOPB_INCLUDE_DIR}
+)
+
+target_link_libraries(grpc_ipv6_loopback_available_test
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  grpc_test_util
+  grpc
+  gpr_test_util
+  gpr
+)
+
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 
 add_executable(grpc_json_token_test
@@ -16351,7 +16383,6 @@ target_link_libraries(resolver_component_tests_runner_invoker
 endif()
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 
 add_executable(address_sorting_test_unsecure
   test/cpp/naming/address_sorting_test.cc
@@ -16391,10 +16422,8 @@ target_link_libraries(address_sorting_test_unsecure
   ${_gRPC_GFLAGS_LIBRARIES}
 )
 
-endif()
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
-if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
 
 add_executable(address_sorting_test
   test/cpp/naming/address_sorting_test.cc
@@ -16434,7 +16463,6 @@ target_link_libraries(address_sorting_test
   ${_gRPC_GFLAGS_LIBRARIES}
 )
 
-endif()
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_MAC OR _gRPC_PLATFORM_POSIX)
diff --git a/Makefile b/Makefile
index bad41975a0..5174ab6719 100644
--- a/Makefile
+++ b/Makefile
@@ -1022,6 +1022,7 @@ grpc_completion_queue_threading_test: $(BINDIR)/$(CONFIG)/grpc_completion_queue_
 grpc_create_jwt: $(BINDIR)/$(CONFIG)/grpc_create_jwt
 grpc_credentials_test: $(BINDIR)/$(CONFIG)/grpc_credentials_test
 grpc_fetch_oauth2: $(BINDIR)/$(CONFIG)/grpc_fetch_oauth2
+grpc_ipv6_loopback_available_test: $(BINDIR)/$(CONFIG)/grpc_ipv6_loopback_available_test
 grpc_json_token_test: $(BINDIR)/$(CONFIG)/grpc_json_token_test
 grpc_jwt_verifier_test: $(BINDIR)/$(CONFIG)/grpc_jwt_verifier_test
 grpc_print_google_default_creds_token: $(BINDIR)/$(CONFIG)/grpc_print_google_default_creds_token
@@ -1472,6 +1473,7 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/grpc_completion_queue_threading_test \
   $(BINDIR)/$(CONFIG)/grpc_credentials_test \
   $(BINDIR)/$(CONFIG)/grpc_fetch_oauth2 \
+  $(BINDIR)/$(CONFIG)/grpc_ipv6_loopback_available_test \
   $(BINDIR)/$(CONFIG)/grpc_json_token_test \
   $(BINDIR)/$(CONFIG)/grpc_jwt_verifier_test \
   $(BINDIR)/$(CONFIG)/grpc_security_connector_test \
@@ -2028,6 +2030,8 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/grpc_completion_queue_threading_test || ( echo test grpc_completion_queue_threading_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpc_credentials_test"
 	$(Q) $(BINDIR)/$(CONFIG)/grpc_credentials_test || ( echo test grpc_credentials_test failed ; exit 1 )
+	$(E) "[RUN]     Testing grpc_ipv6_loopback_available_test"
+	$(Q) $(BINDIR)/$(CONFIG)/grpc_ipv6_loopback_available_test || ( echo test grpc_ipv6_loopback_available_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpc_json_token_test"
 	$(Q) $(BINDIR)/$(CONFIG)/grpc_json_token_test || ( echo test grpc_json_token_test failed ; exit 1 )
 	$(E) "[RUN]     Testing grpc_jwt_verifier_test"
@@ -3704,8 +3708,11 @@ LIBGRPC_SRC = \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
     src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc \
     src/cpp/ext/filters/census/grpc_context.cc \
@@ -4972,8 +4979,11 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
     src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc \
     src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc \
@@ -12365,6 +12375,38 @@ endif
 endif
 
 
+GRPC_IPV6_LOOPBACK_AVAILABLE_TEST_SRC = \
+    test/core/iomgr/grpc_ipv6_loopback_available_test.cc \
+
+GRPC_IPV6_LOOPBACK_AVAILABLE_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(GRPC_IPV6_LOOPBACK_AVAILABLE_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/grpc_ipv6_loopback_available_test: openssl_dep_error
+
+else
+
+
+
+$(BINDIR)/$(CONFIG)/grpc_ipv6_loopback_available_test: $(GRPC_IPV6_LOOPBACK_AVAILABLE_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LD) $(LDFLAGS) $(GRPC_IPV6_LOOPBACK_AVAILABLE_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/grpc_ipv6_loopback_available_test
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/iomgr/grpc_ipv6_loopback_available_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_grpc_ipv6_loopback_available_test: $(GRPC_IPV6_LOOPBACK_AVAILABLE_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(GRPC_IPV6_LOOPBACK_AVAILABLE_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 GRPC_JSON_TOKEN_TEST_SRC = \
     test/core/security/json_token_test.cc \
 
diff --git a/build.yaml b/build.yaml
index 30389ec114..70af96046c 100644
--- a/build.yaml
+++ b/build.yaml
@@ -740,8 +740,11 @@ filegroups:
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
   - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
+  - src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
   plugin: grpc_resolver_dns_ares
   uses:
   - grpc_base
@@ -2730,6 +2733,18 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: grpc_ipv6_loopback_available_test
+  build: test
+  language: c
+  src:
+  - test/core/iomgr/grpc_ipv6_loopback_available_test.cc
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
+  exclude_iomgrs:
+  - uv
 - name: grpc_json_token_test
   build: test
   language: c
diff --git a/config.m4 b/config.m4
index c277ccafc8..aa40a698a6 100644
--- a/config.m4
+++ b/config.m4
@@ -380,8 +380,11 @@ if test "$PHP_GRPC" != "no"; then
     src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
     src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
+    src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
     src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
     src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc \
     src/cpp/ext/filters/census/grpc_context.cc \
diff --git a/config.w32 b/config.w32
index 2857781dd5..5afa4466ac 100644
--- a/config.w32
+++ b/config.w32
@@ -355,8 +355,11 @@ if (PHP_GRPC != "no") {
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\dns_resolver_ares.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_posix.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_ev_driver_windows.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_fallback.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_posix.cc " +
+    "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\c_ares\\grpc_ares_wrapper_windows.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\dns\\native\\dns_resolver.cc " +
     "src\\core\\ext\\filters\\client_channel\\resolver\\sockaddr\\sockaddr_resolver.cc " +
     "src\\cpp\\ext\\filters\\census\\grpc_context.cc " +
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 23edaec656..5c3649afbd 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -802,8 +802,11 @@ Pod::Spec.new do |s|
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
+                      'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
                       'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
                       'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
                       'src/cpp/ext/filters/census/grpc_context.cc',
diff --git a/grpc.gemspec b/grpc.gemspec
index b69d5a7c6f..c250316b99 100644
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -742,8 +742,11 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc )
+  s.files += %w( src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc )
   s.files += %w( src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc )
   s.files += %w( src/cpp/ext/filters/census/grpc_context.cc )
diff --git a/grpc.gyp b/grpc.gyp
index e1485efa05..25082fe540 100644
--- a/grpc.gyp
+++ b/grpc.gyp
@@ -572,8 +572,11 @@
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
         'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
         'src/cpp/ext/filters/census/grpc_context.cc',
@@ -1287,8 +1290,11 @@
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
         'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
+        'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
         'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
         'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
         'src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc',
diff --git a/include/grpc/impl/codegen/port_platform.h b/include/grpc/impl/codegen/port_platform.h
index 01ce5f03e9..2b61a8816d 100644
--- a/include/grpc/impl/codegen/port_platform.h
+++ b/include/grpc/impl/codegen/port_platform.h
@@ -420,12 +420,8 @@ typedef unsigned __int64 uint64_t;
 #define GPR_MAX_ALIGNMENT 16
 
 #ifndef GRPC_ARES
-#ifdef GPR_WINDOWS
-#define GRPC_ARES 0
-#else
 #define GRPC_ARES 1
 #endif
-#endif
 
 #ifndef GRPC_MUST_USE_RESULT
 #if defined(__GNUC__) && !defined(__MINGW32__)
diff --git a/package.xml b/package.xml
index 7f71536b1d..acdc6ffdb3 100644
--- a/package.xml
+++ b/package.xml
@@ -747,8 +747,11 @@
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc" role="src" />
     <file baseinstalldir="/" name="src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc" role="src" />
     <file baseinstalldir="/" name="src/cpp/ext/filters/census/grpc_context.cc" role="src" />
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
index f4f6444c5f..7050e82121 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
@@ -23,7 +23,6 @@
 #include <limits.h>
 #include <stdio.h>
 #include <string.h>
-#include <unistd.h>
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/string_util.h>
@@ -142,8 +141,8 @@ AresDnsResolver::AresDnsResolver(const ResolverArgs& args)
   channel_args_ = grpc_channel_args_copy(args.args);
   const grpc_arg* arg = grpc_channel_args_find(
       channel_args_, GRPC_ARG_SERVICE_CONFIG_DISABLE_RESOLUTION);
-  request_service_config_ = !grpc_channel_arg_get_integer(
-      arg, (grpc_integer_options){false, false, true});
+  grpc_integer_options integer_options = {false, false, true};
+  request_service_config_ = !grpc_channel_arg_get_integer(arg, integer_options);
   arg = grpc_channel_args_find(channel_args_,
                                GRPC_ARG_DNS_MIN_TIME_BETWEEN_RESOLUTIONS_MS);
   min_time_between_resolutions_ =
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
index c886795608..0068d0d5f4 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc
@@ -18,11 +18,10 @@
 #include <grpc/support/port_platform.h>
 
 #include "src/core/lib/iomgr/port.h"
-#if GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET_ARES_EV_DRIVER)
+#if GRPC_ARES == 1 && !defined(GRPC_UV)
 
 #include <ares.h>
 #include <string.h>
-#include <sys/ioctl.h>
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
 
@@ -32,7 +31,6 @@
 #include <grpc/support/time.h>
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/lib/gpr/string.h"
-#include "src/core/lib/iomgr/ev_posix.h"
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
 
@@ -314,4 +312,4 @@ void grpc_ares_ev_driver_start_locked(grpc_ares_ev_driver* ev_driver) {
   }
 }
 
-#endif /* GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET_ARES_EV_DRIVER) */
+#endif /* GRPC_ARES == 1 && !defined(GRPC_UV) */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
new file mode 100644
index 0000000000..5d65ae3ab3
--- /dev/null
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc
@@ -0,0 +1,59 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && defined(GPR_WINDOWS)
+
+#include <ares.h>
+#include <string.h>
+#include "src/core/lib/gprpp/memory.h"
+
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h"
+
+namespace grpc_core {
+
+/* TODO: fill in the body of GrpcPolledFdWindows to enable c-ares on Windows.
+   This dummy implementation only allows grpc to compile on windows with
+   GRPC_ARES=1. */
+class GrpcPolledFdWindows : public GrpcPolledFd {
+ public:
+  GrpcPolledFdWindows() { abort(); }
+  ~GrpcPolledFdWindows() { abort(); }
+  void RegisterForOnReadableLocked(grpc_closure* read_closure) override {
+    abort();
+  }
+  void RegisterForOnWriteableLocked(grpc_closure* write_closure) override {
+    abort();
+  }
+  bool IsFdStillReadableLocked() override { abort(); }
+  void ShutdownLocked(grpc_error* error) override { abort(); }
+  ares_socket_t GetWrappedAresSocketLocked() override { abort(); }
+  const char* GetName() override { abort(); }
+};
+
+GrpcPolledFd* NewGrpcPolledFdLocked(ares_socket_t as,
+                                    grpc_pollset_set* driver_pollset_set) {
+  return nullptr;
+}
+
+void ConfigureAresChannelLocked(ares_channel* channel) { abort(); }
+
+}  // namespace grpc_core
+
+#endif /* GRPC_ARES == 1 && defined(GPR_WINDOWS) */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
index 497ad998af..b3d6437e9a 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc
@@ -22,7 +22,6 @@
 
 #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
 #include "src/core/lib/iomgr/sockaddr.h"
-#include "src/core/lib/iomgr/socket_utils_posix.h"
 
 #include <string.h>
 #include <sys/types.h>
@@ -215,7 +214,7 @@ static void on_hostbyname_done_locked(void* arg, int status, int timeouts,
           memset(&addr, 0, addr_len);
           memcpy(&addr.sin6_addr, hostent->h_addr_list[i - prev_naddr],
                  sizeof(struct in6_addr));
-          addr.sin6_family = static_cast<sa_family_t>(hostent->h_addrtype);
+          addr.sin6_family = static_cast<unsigned char>(hostent->h_addrtype);
           addr.sin6_port = hr->port;
           grpc_lb_addresses_set_address(
               *lb_addresses, i, &addr, addr_len,
@@ -236,7 +235,7 @@ static void on_hostbyname_done_locked(void* arg, int status, int timeouts,
           memset(&addr, 0, addr_len);
           memcpy(&addr.sin_addr, hostent->h_addr_list[i - prev_naddr],
                  sizeof(struct in_addr));
-          addr.sin_family = static_cast<sa_family_t>(hostent->h_addrtype);
+          addr.sin_family = static_cast<unsigned char>(hostent->h_addrtype);
           addr.sin_port = hr->port;
           grpc_lb_addresses_set_address(
               *lb_addresses, i, &addr, addr_len,
@@ -281,7 +280,7 @@ static void on_srv_query_done_locked(void* arg, int status, int timeouts,
           grpc_ares_ev_driver_get_channel_locked(r->ev_driver);
       for (struct ares_srv_reply* srv_it = reply; srv_it != nullptr;
            srv_it = srv_it->next) {
-        if (grpc_ipv6_loopback_available()) {
+        if (grpc_ares_query_ipv6()) {
           grpc_ares_hostbyname_request* hr = create_hostbyname_request_locked(
               r, srv_it->host, htons(srv_it->port), true /* is_balancer */);
           ares_gethostbyname(*channel, hr->host, AF_INET6,
@@ -452,7 +451,7 @@ static grpc_ares_request* grpc_dns_lookup_ares_locked_impl(
     }
   }
   r->pending_queries = 1;
-  if (grpc_ipv6_loopback_available()) {
+  if (grpc_ares_query_ipv6()) {
     hr = create_hostbyname_request_locked(r, host, strhtons(port),
                                           false /* is_balancer */);
     ares_gethostbyname(*channel, hr->host, AF_INET6, on_hostbyname_done_locked,
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
index ce26f5d524..17eaa7ccf0 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h
@@ -70,6 +70,10 @@ void grpc_ares_cleanup(void);
  * and destroys the grpc_ares_request */
 void grpc_ares_complete_request_locked(grpc_ares_request* request);
 
+/* Indicates whether or not AAAA queries should be attempted. */
+/* E.g., return false if ipv6 is known to not be available. */
+bool grpc_ares_query_ipv6();
+
 /* Exposed only for testing */
 void grpc_cares_wrapper_test_only_address_sorting_sort(
     grpc_lb_addresses* lb_addrs);
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
new file mode 100644
index 0000000000..23c0fec74f
--- /dev/null
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc
@@ -0,0 +1,29 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET_ARES_EV_DRIVER)
+
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/lib/iomgr/socket_utils_posix.h"
+
+bool grpc_ares_query_ipv6() { return grpc_ipv6_loopback_available(); }
+
+#endif /* GRPC_ARES == 1 && defined(GRPC_POSIX_SOCKET_ARES_EV_DRIVER) */
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
new file mode 100644
index 0000000000..ee827e284e
--- /dev/null
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc
@@ -0,0 +1,29 @@
+/*
+ *
+ * Copyright 2016 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/port.h"
+#if GRPC_ARES == 1 && defined(GPR_WINDOWS)
+
+#include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h"
+#include "src/core/lib/iomgr/socket_windows.h"
+
+bool grpc_ares_query_ipv6() { return grpc_ipv6_loopback_available(); }
+
+#endif /* GRPC_ARES == 1 && defined(GPR_WINDOWS) */
diff --git a/src/core/lib/iomgr/socket_windows.cc b/src/core/lib/iomgr/socket_windows.cc
index 2e23409582..4ad31cb35d 100644
--- a/src/core/lib/iomgr/socket_windows.cc
+++ b/src/core/lib/iomgr/socket_windows.cc
@@ -36,6 +36,7 @@
 #include "src/core/lib/iomgr/iomgr_internal.h"
 #include "src/core/lib/iomgr/pollset.h"
 #include "src/core/lib/iomgr/pollset_windows.h"
+#include "src/core/lib/iomgr/sockaddr_windows.h"
 #include "src/core/lib/iomgr/socket_windows.h"
 
 grpc_winsocket* grpc_winsocket_create(SOCKET socket, const char* name) {
@@ -148,4 +149,32 @@ void grpc_socket_become_ready(grpc_winsocket* socket,
   if (should_destroy) destroy(socket);
 }
 
+static gpr_once g_probe_ipv6_once = GPR_ONCE_INIT;
+static bool g_ipv6_loopback_available = false;
+
+static void probe_ipv6_once(void) {
+  SOCKET s = socket(AF_INET6, SOCK_STREAM, 0);
+  g_ipv6_loopback_available = 0;
+  if (s == INVALID_SOCKET) {
+    gpr_log(GPR_INFO, "Disabling AF_INET6 sockets because socket() failed.");
+  } else {
+    grpc_sockaddr_in6 addr;
+    memset(&addr, 0, sizeof(addr));
+    addr.sin6_family = AF_INET6;
+    addr.sin6_addr.s6_addr[15] = 1; /* [::1]:0 */
+    if (bind(s, reinterpret_cast<grpc_sockaddr*>(&addr), sizeof(addr)) == 0) {
+      g_ipv6_loopback_available = 1;
+    } else {
+      gpr_log(GPR_INFO,
+              "Disabling AF_INET6 sockets because ::1 is not available.");
+    }
+    closesocket(s);
+  }
+}
+
+int grpc_ipv6_loopback_available(void) {
+  gpr_once_init(&g_probe_ipv6_once, probe_ipv6_once);
+  return g_ipv6_loopback_available;
+}
+
 #endif /* GRPC_WINSOCK_SOCKET */
diff --git a/src/core/lib/iomgr/socket_windows.h b/src/core/lib/iomgr/socket_windows.h
index 7bd01eded5..b09b9da562 100644
--- a/src/core/lib/iomgr/socket_windows.h
+++ b/src/core/lib/iomgr/socket_windows.h
@@ -108,6 +108,10 @@ void grpc_socket_notify_on_read(grpc_winsocket* winsocket,
 void grpc_socket_become_ready(grpc_winsocket* winsocket,
                               grpc_winsocket_callback_info* ci);
 
+/* Returns true if this system can create AF_INET6 sockets bound to ::1.
+   The value is probed once, and cached for the life of the process. */
+int grpc_ipv6_loopback_available(void);
+
 #endif
 
 #endif /* GRPC_CORE_LIB_IOMGR_SOCKET_WINDOWS_H */
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index 49185cc648..d6efb49750 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -354,8 +354,11 @@ CORE_SOURCE_FILES = [
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc',
+    'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc',
     'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc',
+    'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc',
+    'src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc',
     'src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc',
     'src/core/ext/filters/client_channel/resolver/sockaddr/sockaddr_resolver.cc',
     'src/cpp/ext/filters/census/grpc_context.cc',
diff --git a/test/core/iomgr/BUILD b/test/core/iomgr/BUILD
index fb0490a95f..002671a5fa 100644
--- a/test/core/iomgr/BUILD
+++ b/test/core/iomgr/BUILD
@@ -125,6 +125,19 @@ grpc_cc_test(
 )
 
 grpc_cc_test(
+    name = "grpc_ipv6_loopback_available_test",
+    srcs = ["grpc_ipv6_loopback_available_test.cc"],
+    language = "C++",
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:gpr_test_util",
+        "//test/core/util:grpc_test_util",
+    ],
+)
+
+
+grpc_cc_test(
     name = "load_file_test",
     srcs = ["load_file_test.cc"],
     language = "C++",
diff --git a/test/core/iomgr/grpc_ipv6_loopback_available_test.cc b/test/core/iomgr/grpc_ipv6_loopback_available_test.cc
new file mode 100644
index 0000000000..329aa9a851
--- /dev/null
+++ b/test/core/iomgr/grpc_ipv6_loopback_available_test.cc
@@ -0,0 +1,48 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+// grpc_ipv6_loopback_available isn't currently available on UV.
+#ifndef GRPC_UV
+
+#include <grpc/grpc.h>
+#include <grpc/support/log.h>
+#include "test/core/util/test_config.h"
+
+#ifdef GPR_WINDOWS
+#include "src/core/lib/iomgr/socket_windows.h"
+#else
+#include "src/core/lib/iomgr/socket_utils_posix.h"
+#endif
+
+int main(int argc, char** argv) {
+  grpc_test_init(argc, argv);
+  grpc_init();
+  // This test assumes that the ipv6 loopback is available
+  // in all environments in which grpc tests run in.
+  GPR_ASSERT(grpc_ipv6_loopback_available());
+  grpc_shutdown();
+  return 0;
+}
+
+#else
+
+int main(int argc, char** argv) { return 0; }
+
+#endif /* GRPC_UV */
diff --git a/test/cpp/naming/address_sorting_test.cc b/test/cpp/naming/address_sorting_test.cc
index a92e9e3b3e..04c300876c 100644
--- a/test/cpp/naming/address_sorting_test.cc
+++ b/test/cpp/naming/address_sorting_test.cc
@@ -24,10 +24,8 @@
 #include <grpc/support/time.h>
 #include <string.h>
 
-#include <arpa/inet.h>
 #include <gflags/gflags.h>
 #include <gmock/gmock.h>
-#include <sys/socket.h>
 #include <sys/types.h>
 #include <vector>
 
@@ -51,6 +49,11 @@
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
 
+#ifndef GPR_WINDOWS
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#endif
+
 namespace {
 
 struct TestAddress {
@@ -190,10 +193,18 @@ void VerifyLbAddrOutputs(grpc_lb_addresses* lb_addrs,
   grpc_lb_addresses_destroy(lb_addrs);
 }
 
-}  // namespace
+/* We need to run each test case inside of its own
+ * isolated grpc_init/grpc_shutdown pair, so that
+ * the "address sorting source addr factory" can be
+ * restored to its default for each test case. */
+class AddressSortingTest : public ::testing::Test {
+ protected:
+  void SetUp() override { grpc_init(); }
+  void TearDown() override { grpc_shutdown(); }
+};
 
 /* Tests for rule 1 */
-TEST(AddressSortingTest, TestDepriotizesUnreachableAddresses) {
+TEST_F(AddressSortingTest, TestDepriotizesUnreachableAddresses) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -212,7 +223,7 @@ TEST(AddressSortingTest, TestDepriotizesUnreachableAddresses) {
                                 });
 }
 
-TEST(AddressSortingTest, TestDepriotizesUnsupportedDomainIpv6) {
+TEST_F(AddressSortingTest, TestDepriotizesUnsupportedDomainIpv6) {
   bool ipv4_supported = true;
   bool ipv6_supported = false;
   OverrideAddressSortingSourceAddrFactory(
@@ -231,7 +242,7 @@ TEST(AddressSortingTest, TestDepriotizesUnsupportedDomainIpv6) {
                                 });
 }
 
-TEST(AddressSortingTest, TestDepriotizesUnsupportedDomainIpv4) {
+TEST_F(AddressSortingTest, TestDepriotizesUnsupportedDomainIpv4) {
   bool ipv4_supported = false;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -253,7 +264,7 @@ TEST(AddressSortingTest, TestDepriotizesUnsupportedDomainIpv4) {
 
 /* Tests for rule 2 */
 
-TEST(AddressSortingTest, TestDepriotizesNonMatchingScope) {
+TEST_F(AddressSortingTest, TestDepriotizesNonMatchingScope) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -277,7 +288,7 @@ TEST(AddressSortingTest, TestDepriotizesNonMatchingScope) {
 
 /* Tests for rule 5 */
 
-TEST(AddressSortingTest, TestUsesLabelFromDefaultTable) {
+TEST_F(AddressSortingTest, TestUsesLabelFromDefaultTable) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -300,7 +311,7 @@ TEST(AddressSortingTest, TestUsesLabelFromDefaultTable) {
 
 /* Flip the input on the test above to reorder the sort function's
  * comparator's inputs. */
-TEST(AddressSortingTest, TestUsesLabelFromDefaultTableInputFlipped) {
+TEST_F(AddressSortingTest, TestUsesLabelFromDefaultTableInputFlipped) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -323,8 +334,8 @@ TEST(AddressSortingTest, TestUsesLabelFromDefaultTableInputFlipped) {
 
 /* Tests for rule 6 */
 
-TEST(AddressSortingTest,
-     TestUsesDestinationWithHigherPrecedenceWithAnIpv4Address) {
+TEST_F(AddressSortingTest,
+       TestUsesDestinationWithHigherPrecedenceWithAnIpv4Address) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -348,8 +359,8 @@ TEST(AddressSortingTest,
                 });
 }
 
-TEST(AddressSortingTest,
-     TestUsesDestinationWithHigherPrecedenceWithV4CompatAndLocalhostAddress) {
+TEST_F(AddressSortingTest,
+       TestUsesDestinationWithHigherPrecedenceWithV4CompatAndLocalhostAddress) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
 // Handle unique observed behavior of inet_ntop(v4-compatible-address) on OS X.
@@ -377,8 +388,8 @@ TEST(AddressSortingTest,
                                 });
 }
 
-TEST(AddressSortingTest,
-     TestUsesDestinationWithHigherPrecedenceWithCatchAllAndLocalhostAddress) {
+TEST_F(AddressSortingTest,
+       TestUsesDestinationWithHigherPrecedenceWithCatchAllAndLocalhostAddress) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -403,8 +414,8 @@ TEST(AddressSortingTest,
       });
 }
 
-TEST(AddressSortingTest,
-     TestUsesDestinationWithHigherPrecedenceWith2000PrefixedAddress) {
+TEST_F(AddressSortingTest,
+       TestUsesDestinationWithHigherPrecedenceWith2000PrefixedAddress) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -426,7 +437,7 @@ TEST(AddressSortingTest,
                 });
 }
 
-TEST(
+TEST_F(
     AddressSortingTest,
     TestUsesDestinationWithHigherPrecedenceWith2000PrefixedAddressEnsurePrefixMatchHasNoEffect) {
   bool ipv4_supported = true;
@@ -448,8 +459,8 @@ TEST(
                                 });
 }
 
-TEST(AddressSortingTest,
-     TestUsesDestinationWithHigherPrecedenceWithLinkAndSiteLocalAddresses) {
+TEST_F(AddressSortingTest,
+       TestUsesDestinationWithHigherPrecedenceWithLinkAndSiteLocalAddresses) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -469,19 +480,22 @@ TEST(AddressSortingTest,
                                 });
 }
 
-TEST(
+TEST_F(
     AddressSortingTest,
     TestUsesDestinationWithHigherPrecedenceWithCatchAllAndAndV4MappedAddresses) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
+  // Use embedded ipv4 addresses with leading 1's instead of zero's to be
+  // compatible with inet_ntop implementations that can display such
+  // addresses with leading zero's as e.g.: "::ffff:0:2", as on windows.
   OverrideAddressSortingSourceAddrFactory(
       ipv4_supported, ipv6_supported,
       {
-          {"[::ffff:0.0.0.2]:443", {"[::ffff:0.0.0.3]:0", AF_INET6}},
+          {"[::ffff:1.1.1.2]:443", {"[::ffff:1.1.1.3]:0", AF_INET6}},
           {"[1234::2]:443", {"[1234::3]:0", AF_INET6}},
       });
   grpc_lb_addresses* lb_addrs = BuildLbAddrInputs({
-      {"[::ffff:0.0.0.2]:443", AF_INET6},
+      {"[::ffff:1.1.1.2]:443", AF_INET6},
       {"[1234::2]:443", AF_INET6},
   });
   grpc_cares_wrapper_test_only_address_sorting_sort(lb_addrs);
@@ -489,13 +503,13 @@ TEST(
                                     // ::ffff:0:2 should match the v4-mapped
                                     // precedence entry and be deprioritized.
                                     "[1234::2]:443",
-                                    "[::ffff:0.0.0.2]:443",
+                                    "[::ffff:1.1.1.2]:443",
                                 });
 }
 
 /* Tests for rule 8 */
 
-TEST(AddressSortingTest, TestPrefersSmallerScope) {
+TEST_F(AddressSortingTest, TestPrefersSmallerScope) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -520,7 +534,7 @@ TEST(AddressSortingTest, TestPrefersSmallerScope) {
 
 /* Tests for rule 9 */
 
-TEST(AddressSortingTest, TestPrefersLongestMatchingSrcDstPrefix) {
+TEST_F(AddressSortingTest, TestPrefersLongestMatchingSrcDstPrefix) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -543,8 +557,8 @@ TEST(AddressSortingTest, TestPrefersLongestMatchingSrcDstPrefix) {
                                 });
 }
 
-TEST(AddressSortingTest,
-     TestPrefersLongestMatchingSrcDstPrefixMatchesWholeAddress) {
+TEST_F(AddressSortingTest,
+       TestPrefersLongestMatchingSrcDstPrefixMatchesWholeAddress) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -564,7 +578,7 @@ TEST(AddressSortingTest,
                                 });
 }
 
-TEST(AddressSortingTest, TestPrefersLongestPrefixStressInnerBytePrefix) {
+TEST_F(AddressSortingTest, TestPrefersLongestPrefixStressInnerBytePrefix) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -584,7 +598,7 @@ TEST(AddressSortingTest, TestPrefersLongestPrefixStressInnerBytePrefix) {
                                 });
 }
 
-TEST(AddressSortingTest, TestPrefersLongestPrefixDiffersOnHighestBitOfByte) {
+TEST_F(AddressSortingTest, TestPrefersLongestPrefixDiffersOnHighestBitOfByte) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -604,7 +618,7 @@ TEST(AddressSortingTest, TestPrefersLongestPrefixDiffersOnHighestBitOfByte) {
                                 });
 }
 
-TEST(AddressSortingTest, TestPrefersLongestPrefixDiffersByLastBit) {
+TEST_F(AddressSortingTest, TestPrefersLongestPrefixDiffersByLastBit) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -628,7 +642,7 @@ TEST(AddressSortingTest, TestPrefersLongestPrefixDiffersByLastBit) {
 
 /* Tests for rule 10 */
 
-TEST(AddressSortingTest, TestStableSort) {
+TEST_F(AddressSortingTest, TestStableSort) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -648,7 +662,7 @@ TEST(AddressSortingTest, TestStableSort) {
                                 });
 }
 
-TEST(AddressSortingTest, TestStableSortFiveElements) {
+TEST_F(AddressSortingTest, TestStableSortFiveElements) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(
@@ -677,7 +691,7 @@ TEST(AddressSortingTest, TestStableSortFiveElements) {
                                 });
 }
 
-TEST(AddressSortingTest, TestStableSortNoSrcAddrsExist) {
+TEST_F(AddressSortingTest, TestStableSortNoSrcAddrsExist) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(ipv4_supported, ipv6_supported, {});
@@ -698,7 +712,7 @@ TEST(AddressSortingTest, TestStableSortNoSrcAddrsExist) {
                                 });
 }
 
-TEST(AddressSortingTest, TestStableSortNoSrcAddrsExistWithIpv4) {
+TEST_F(AddressSortingTest, TestStableSortNoSrcAddrsExistWithIpv4) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
   OverrideAddressSortingSourceAddrFactory(ipv4_supported, ipv6_supported, {});
@@ -713,7 +727,7 @@ TEST(AddressSortingTest, TestStableSortNoSrcAddrsExistWithIpv4) {
                                 });
 }
 
-TEST(AddressSortingTest, TestStableSortV4CompatAndSiteLocalAddresses) {
+TEST_F(AddressSortingTest, TestStableSortV4CompatAndSiteLocalAddresses) {
   bool ipv4_supported = true;
   bool ipv6_supported = true;
 // Handle unique observed behavior of inet_ntop(v4-compatible-address) on OS X.
@@ -744,6 +758,78 @@ TEST(AddressSortingTest, TestStableSortV4CompatAndSiteLocalAddresses) {
                       });
 }
 
+/* TestPrefersIpv6Loopback tests the actual "address probing" code
+ * for the current platform, without any mocks.
+ * This test relies on the assumption that the ipv6 loopback address is
+ * available in the hosts/containers that grpc C/C++ tests run on
+ * (whether ipv4 loopback is available or not, an available ipv6
+ * loopback should be preferred). */
+TEST_F(AddressSortingTest, TestPrefersIpv6Loopback) {
+  grpc_lb_addresses* lb_addrs = BuildLbAddrInputs({
+      {"[::1]:443", AF_INET6},
+      {"127.0.0.1:443", AF_INET},
+  });
+  grpc_cares_wrapper_test_only_address_sorting_sort(lb_addrs);
+  VerifyLbAddrOutputs(lb_addrs, {
+                                    "[::1]:443",
+                                    "127.0.0.1:443",
+                                });
+}
+
+/* Flip the order of the inputs above and expect the same output order
+ * (try to rule out influence of arbitrary qsort ordering) */
+TEST_F(AddressSortingTest, TestPrefersIpv6LoopbackInputsFlipped) {
+  grpc_lb_addresses* lb_addrs = BuildLbAddrInputs({
+      {"127.0.0.1:443", AF_INET},
+      {"[::1]:443", AF_INET6},
+  });
+  grpc_cares_wrapper_test_only_address_sorting_sort(lb_addrs);
+  VerifyLbAddrOutputs(lb_addrs, {
+                                    "[::1]:443",
+                                    "127.0.0.1:443",
+                                });
+}
+
+/* Try to rule out false positives in the above two tests in which
+ * the sorter might think that neither ipv6 or ipv4 loopback is
+ * available, but ipv6 loopback is still preferred only due
+ * to precedance table lookups. */
+TEST_F(AddressSortingTest, TestSorterKnowsIpv6LoopbackIsAvailable) {
+  sockaddr_in6 ipv6_loopback;
+  memset(&ipv6_loopback, 0, sizeof(ipv6_loopback));
+  ipv6_loopback.sin6_family = AF_INET6;
+  ((char*)&ipv6_loopback.sin6_addr)[15] = 1;
+  ipv6_loopback.sin6_port = htons(443);
+  // Set up the source and destination parameters of
+  // address_sorting_get_source_addr
+  address_sorting_address sort_input_dest;
+  memcpy(&sort_input_dest.addr, &ipv6_loopback, sizeof(ipv6_loopback));
+  sort_input_dest.len = sizeof(ipv6_loopback);
+  address_sorting_address source_for_sort_input_dest;
+  memset(&source_for_sort_input_dest, 0, sizeof(source_for_sort_input_dest));
+  // address_sorting_get_source_addr returns true if a source address was found
+  // for the destination address, otherwise false.
+  EXPECT_TRUE(address_sorting_get_source_addr_for_testing(
+      &sort_input_dest, &source_for_sort_input_dest));
+  // Now also check that the source address was filled in correctly.
+  EXPECT_GT(source_for_sort_input_dest.len, 0u);
+  sockaddr_in6* source_addr_output =
+      (sockaddr_in6*)source_for_sort_input_dest.addr;
+  EXPECT_EQ(source_addr_output->sin6_family, AF_INET6);
+  char* buf = static_cast<char*>(gpr_zalloc(100));
+  EXPECT_NE(inet_ntop(AF_INET6, &source_addr_output->sin6_addr, buf, 100),
+            nullptr)
+      << "inet_ntop failed. Errno: " + std::to_string(errno);
+  std::string source_addr_str(buf);
+  gpr_free(buf);
+  // This test
+  // assumes that the source address for any loopback destination is also the
+  // loopback address.
+  EXPECT_EQ(source_addr_str, "::1");
+}
+
+}  // namespace
+
 int main(int argc, char** argv) {
   char* resolver = gpr_getenv("GRPC_DNS_RESOLVER");
   if (resolver == nullptr || strlen(resolver) == 0) {
@@ -754,9 +840,7 @@ int main(int argc, char** argv) {
   gpr_free(resolver);
   grpc_test_init(argc, argv);
   ::testing::InitGoogleTest(&argc, argv);
-  grpc_init();
   auto result = RUN_ALL_TESTS();
-  grpc_shutdown();
   // Test sequential and nested inits and shutdowns.
   grpc_init();
   grpc_init();
diff --git a/test/cpp/naming/gen_build_yaml.py b/test/cpp/naming/gen_build_yaml.py
index baa6512f62..5dad2ea7af 100755
--- a/test/cpp/naming/gen_build_yaml.py
+++ b/test/cpp/naming/gen_build_yaml.py
@@ -110,7 +110,7 @@ def main():
               'gtest': True,
               'run': True,
               'src': ['test/cpp/naming/address_sorting_test.cc'],
-              'platforms': ['linux', 'posix', 'mac'],
+              'platforms': ['linux', 'posix', 'mac', 'windows'],
               'deps': [
                   'grpc++_test_util' + unsecure_build_config_suffix,
                   'grpc_test_util' + unsecure_build_config_suffix,
diff --git a/third_party/address_sorting/address_sorting.c b/third_party/address_sorting/address_sorting.c
index e4f3b53799..9aee0a5419 100644
--- a/third_party/address_sorting/address_sorting.c
+++ b/third_party/address_sorting/address_sorting.c
@@ -55,12 +55,17 @@ static const int kIPv6AddrScopeGlobal = 3;
 static address_sorting_source_addr_factory* g_current_source_addr_factory =
     NULL;
 
-static int address_sorting_get_source_addr(const address_sorting_address* dest,
-                                           address_sorting_address* source) {
+static bool address_sorting_get_source_addr(const address_sorting_address* dest,
+                                            address_sorting_address* source) {
   return g_current_source_addr_factory->vtable->get_source_addr(
       g_current_source_addr_factory, dest, source);
 }
 
+bool address_sorting_get_source_addr_for_testing(
+    const address_sorting_address* dest, address_sorting_address* source) {
+  return address_sorting_get_source_addr(dest, source);
+}
+
 static int ipv6_prefix_match_length(const struct sockaddr_in6* sa,
                                     const struct sockaddr_in6* sb) {
   unsigned char* a = (unsigned char*)&sa->sin6_addr;
diff --git a/third_party/address_sorting/address_sorting_windows.c b/third_party/address_sorting/address_sorting_windows.c
index b2f5708649..662a88248e 100644
--- a/third_party/address_sorting/address_sorting_windows.c
+++ b/third_party/address_sorting/address_sorting_windows.c
@@ -42,14 +42,54 @@
 
 #if defined(ADDRESS_SORTING_WINDOWS)
 
+#include <errno.h>
+#include <inttypes.h>
+#include <limits.h>
 #include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
 
-/* TODO : Add address sorting functionality to work on windows. */
+static bool windows_source_addr_factory_get_source_addr(
+    address_sorting_source_addr_factory* factory,
+    const address_sorting_address* dest_addr,
+    address_sorting_address* source_addr) {
+  bool source_addr_exists = false;
+  SOCKET s = socket(((struct sockaddr_in6*)dest_addr)->sin6_family, SOCK_DGRAM,
+                    IPPROTO_UDP);
+  if (s != INVALID_SOCKET) {
+    if (connect(s, (struct sockaddr*)dest_addr, (int)dest_addr->len) == 0) {
+      address_sorting_address found_source_addr;
+      memset(&found_source_addr, 0, sizeof(found_source_addr));
+      found_source_addr.len = sizeof(found_source_addr.addr);
+      if (getsockname(s, (struct sockaddr*)&found_source_addr.addr,
+                      (socklen_t*)&found_source_addr.len) == 0) {
+        source_addr_exists = true;
+        *source_addr = found_source_addr;
+      }
+    }
+    closesocket(s);
+  }
+  return source_addr_exists;
+}
+
+static void windows_source_addr_factory_destroy(
+    address_sorting_source_addr_factory* self) {
+  free(self);
+}
+
+static const address_sorting_source_addr_factory_vtable
+    windows_source_addr_factory_vtable = {
+        windows_source_addr_factory_get_source_addr,
+        windows_source_addr_factory_destroy,
+};
 
 address_sorting_source_addr_factory*
 address_sorting_create_source_addr_factory_for_current_platform() {
-  abort();
-  return NULL;
+  address_sorting_source_addr_factory* factory =
+      malloc(sizeof(address_sorting_source_addr_factory));
+  memset(factory, 0, sizeof(address_sorting_source_addr_factory));
+  factory->vtable = &windows_source_addr_factory_vtable;
+  return factory;
 }
 
 #endif  // defined(ADDRESS_SORTING_WINDOWS)
diff --git a/third_party/address_sorting/include/address_sorting/address_sorting.h b/third_party/address_sorting/include/address_sorting/address_sorting.h
index f11cd424b5..c58fafe3f7 100644
--- a/third_party/address_sorting/include/address_sorting/address_sorting.h
+++ b/third_party/address_sorting/include/address_sorting/address_sorting.h
@@ -103,6 +103,9 @@ address_sorting_family address_sorting_abstract_get_family(
 void address_sorting_override_source_addr_factory_for_testing(
     address_sorting_source_addr_factory* factory);
 
+bool address_sorting_get_source_addr_for_testing(
+    const address_sorting_address* dest, address_sorting_address* source);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index 576950934e..18f56984fe 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -924,9 +924,12 @@ src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc \
+src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h \
 src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc \
+src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc \
+src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc \
 src/core/ext/filters/client_channel/resolver/dns/native/README.md \
 src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc \
 src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc \
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 072402b2cf..a686dae8b4 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -1042,6 +1042,23 @@
     "headers": [], 
     "is_filegroup": false, 
     "language": "c", 
+    "name": "grpc_ipv6_loopback_available_test", 
+    "src": [
+      "test/core/iomgr/grpc_ipv6_loopback_available_test.cc"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util", 
+      "grpc", 
+      "grpc_test_util"
+    ], 
+    "headers": [], 
+    "is_filegroup": false, 
+    "language": "c", 
     "name": "grpc_json_token_test", 
     "src": [
       "test/core/security/json_token_test.cc"
@@ -10254,9 +10271,12 @@
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc", 
+      "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc", 
       "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h", 
-      "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc"
+      "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc", 
+      "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc", 
+      "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc"
     ], 
     "third_party": false, 
     "type": "filegroup"
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index a5439a5db1..5815f82fef 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -1319,6 +1319,32 @@
     "ci_platforms": [
       "linux", 
       "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "gtest": false, 
+    "language": "c", 
+    "name": "grpc_ipv6_loopback_available_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "uses_polling": true
+  }, 
+  {
+    "args": [], 
+    "benchmark": false, 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
       "posix"
     ], 
     "cpu_cost": 1.0, 
@@ -5710,7 +5736,8 @@
     "ci_platforms": [
       "linux", 
       "mac", 
-      "posix"
+      "posix", 
+      "windows"
     ], 
     "cpu_cost": 1.0, 
     "exclude_configs": [], 
@@ -5722,7 +5749,8 @@
     "platforms": [
       "linux", 
       "mac", 
-      "posix"
+      "posix", 
+      "windows"
     ], 
     "uses_polling": true
   }, 
@@ -5732,7 +5760,8 @@
     "ci_platforms": [
       "linux", 
       "mac", 
-      "posix"
+      "posix", 
+      "windows"
     ], 
     "cpu_cost": 1.0, 
     "exclude_configs": [], 
@@ -5744,7 +5773,8 @@
     "platforms": [
       "linux", 
       "mac", 
-      "posix"
+      "posix", 
+      "windows"
     ], 
     "uses_polling": true
   },