[EventEngine] [reland] Migrate `chttp2_server` to use EE DNSResolver (#37901)

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Closes #37901

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/37901 from yijiem:dns-migration-chttp2-server-2 70d29b3b6c
PiperOrigin-RevId: 687466646

bazel/experiments.bzl

@@ -23,6 +23,7 @@ EXPERIMENT_ENABLES = {
     "event_engine_application_callbacks": "event_engine_application_callbacks",
     "event_engine_client": "event_engine_client",
     "event_engine_dns": "event_engine_dns",
+    "event_engine_dns_non_client_channel": "event_engine_dns_non_client_channel",
     "event_engine_listener": "event_engine_listener",
     "free_large_allocator": "free_large_allocator",
     "local_connector_secure": "local_connector_secure",
@@ -45,6 +46,7 @@ EXPERIMENT_ENABLES = {
 EXPERIMENT_POLLERS = [
     "event_engine_client",
     "event_engine_dns",
+    "event_engine_dns_non_client_channel",
     "event_engine_listener",
 ]
 
@@ -54,6 +56,7 @@ EXPERIMENTS = {
         },
         "off": {
             "core_end2end_test": [
+                "event_engine_dns_non_client_channel",
                 "local_connector_secure",
             ],
             "endpoint_test": [
@@ -103,6 +106,7 @@ EXPERIMENTS = {
         },
         "off": {
             "core_end2end_test": [
+                "event_engine_dns_non_client_channel",
                 "local_connector_secure",
             ],
             "endpoint_test": [
@@ -136,6 +140,7 @@ EXPERIMENTS = {
         },
         "off": {
             "core_end2end_test": [
+                "event_engine_dns_non_client_channel",
                 "local_connector_secure",
             ],
             "endpoint_test": [

src/core/BUILD

@@ -2378,9 +2378,11 @@ grpc_cc_library(
     hdrs = ["lib/event_engine/utils.h"],
     external_deps = [
         "absl/log:check",
+        "absl/status:statusor",
         "absl/strings",
     ],
     deps = [
+        "notification",
         "time",
         "//:event_engine_base_hdrs",
         "//:gpr_platform",
@@ -7658,8 +7660,11 @@ grpc_cc_library(
         "connection_quota",
         "error",
         "error_utils",
+        "event_engine_common",
         "event_engine_extensions",
         "event_engine_query_extensions",
+        "event_engine_tcp_socket_utils",
+        "event_engine_utils",
         "grpc_insecure_credentials",
         "handshaker_registry",
         "iomgr_fwd",

src/core/ext/transport/chttp2/server/chttp2_server.cc

@@ -59,6 +59,9 @@
 #include "src/core/lib/event_engine/channel_args_endpoint_config.h"
 #include "src/core/lib/event_engine/extensions/supports_fd.h"
 #include "src/core/lib/event_engine/query_extensions.h"
+#include "src/core/lib/event_engine/resolved_address_internal.h"
+#include "src/core/lib/event_engine/tcp_socket_utils.h"
+#include "src/core/lib/event_engine/utils.h"
 #include "src/core/lib/iomgr/closure.h"
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/event_engine_shims/endpoint.h"
@@ -113,7 +116,8 @@ using AcceptorPtr = std::unique_ptr<grpc_tcp_server_acceptor, AcceptorDeleter>;
 
 class Chttp2ServerListener : public Server::ListenerInterface {
  public:
-  static grpc_error_handle Create(Server* server, grpc_resolved_address* addr,
+  static grpc_error_handle Create(Server* server,
+                                  const EventEngine::ResolvedAddress& addr,
                                   const ChannelArgs& args,
                                   Chttp2ServerArgsModifier args_modifier,
                                   int* port_num);
@@ -703,8 +707,9 @@ void Chttp2ServerListener::ActiveConnection::OnDrainGraceTimeExpiry() {
 //
 
 grpc_error_handle Chttp2ServerListener::Create(
-    Server* server, grpc_resolved_address* addr, const ChannelArgs& args,
-    Chttp2ServerArgsModifier args_modifier, int* port_num) {
+    Server* server, const EventEngine::ResolvedAddress& addr,
+    const ChannelArgs& args, Chttp2ServerArgsModifier args_modifier,
+    int* port_num) {
   // Create Chttp2ServerListener.
   OrphanablePtr<Chttp2ServerListener> listener =
       MakeOrphanable<Chttp2ServerListener>(server, args, args_modifier,
@@ -716,18 +721,24 @@ grpc_error_handle Chttp2ServerListener::Create(
       &listener->tcp_server_shutdown_complete_, ChannelArgsEndpointConfig(args),
       OnAccept, listener.get(), &listener->tcp_server_);
   if (!error.ok()) return error;
+  // TODO(yijiem): remove this conversion when we remove all
+  // grpc_resolved_address usages.
+  grpc_resolved_address iomgr_addr =
+      grpc_event_engine::experimental::CreateGRPCResolvedAddress(addr);
   if (listener->config_fetcher_ != nullptr) {
-    listener->resolved_address_ = *addr;
+    listener->resolved_address_ = iomgr_addr;
     // TODO(yashykt): Consider binding so as to be able to return the port
     // number.
   } else {
-    error = grpc_tcp_server_add_port(listener->tcp_server_, addr, port_num);
+    error =
+        grpc_tcp_server_add_port(listener->tcp_server_, &iomgr_addr, port_num);
     if (!error.ok()) return error;
   }
   // Create channelz node.
   if (args.GetBool(GRPC_ARG_ENABLE_CHANNELZ)
           .value_or(GRPC_ENABLE_CHANNELZ_DEFAULT)) {
-    auto string_address = grpc_sockaddr_to_uri(addr);
+    auto string_address =
+        grpc_event_engine::experimental::ResolvedAddressToString(addr);
     if (!string_address.ok()) {
       return GRPC_ERROR_CREATE(string_address.status().ToString());
     }
@@ -957,37 +968,68 @@ grpc_error_handle Chttp2ServerAddPort(Server* server, const char* addr,
                                                     args_modifier);
   }
   *port_num = -1;
-  absl::StatusOr<std::vector<grpc_resolved_address>> resolved_or;
+  absl::StatusOr<std::vector<grpc_resolved_address>> resolved;
+  absl::StatusOr<std::vector<EventEngine::ResolvedAddress>> results =
+      std::vector<EventEngine::ResolvedAddress>();
   std::vector<grpc_error_handle> error_list;
   std::string parsed_addr = URI::PercentDecode(addr);
   absl::string_view parsed_addr_unprefixed{parsed_addr};
   // Using lambda to avoid use of goto.
   grpc_error_handle error = [&]() {
     grpc_error_handle error;
+    // TODO(ladynana, yijiem): this code does not handle address URIs correctly:
+    // it's parsing `unix://foo/bar` as path `/foo/bar` when it should be
+    // parsing it as authority `foo` and path `/bar`. Also add API documentation
+    // on the valid URIs that grpc_server_add_http2_port accepts.
     if (absl::ConsumePrefix(&parsed_addr_unprefixed, kUnixUriPrefix)) {
-      resolved_or = grpc_resolve_unix_domain_address(parsed_addr_unprefixed);
+      resolved = grpc_resolve_unix_domain_address(parsed_addr_unprefixed);
+      GRPC_RETURN_IF_ERROR(resolved.status());
     } else if (absl::ConsumePrefix(&parsed_addr_unprefixed,
                                    kUnixAbstractUriPrefix)) {
-      resolved_or =
+      resolved =
           grpc_resolve_unix_abstract_domain_address(parsed_addr_unprefixed);
+      GRPC_RETURN_IF_ERROR(resolved.status());
     } else if (absl::ConsumePrefix(&parsed_addr_unprefixed, kVSockUriPrefix)) {
-      resolved_or = grpc_resolve_vsock_address(parsed_addr_unprefixed);
+      resolved = grpc_resolve_vsock_address(parsed_addr_unprefixed);
+      GRPC_RETURN_IF_ERROR(resolved.status());
+    } else {
+      if (IsEventEngineDnsNonClientChannelEnabled()) {
+        absl::StatusOr<std::unique_ptr<EventEngine::DNSResolver>> ee_resolver =
+            args.GetObjectRef<EventEngine>()->GetDNSResolver(
+                EventEngine::DNSResolver::ResolverOptions());
+        GRPC_RETURN_IF_ERROR(ee_resolver.status());
+        results = grpc_event_engine::experimental::LookupHostnameBlocking(
+            ee_resolver->get(), parsed_addr, "https");
       } else {
-      resolved_or =
+        // TODO(yijiem): Remove this after event_engine_dns_non_client_channel
+        // is fully enabled.
+        absl::StatusOr<std::vector<grpc_resolved_address>> iomgr_results =
             GetDNSResolver()->LookupHostnameBlocking(parsed_addr, "https");
+        GRPC_RETURN_IF_ERROR(iomgr_results.status());
+        for (const auto& addr : *iomgr_results) {
+          results->push_back(
+              grpc_event_engine::experimental::CreateResolvedAddress(addr));
+        }
       }
-    if (!resolved_or.ok()) {
-      return absl_status_to_grpc_error(resolved_or.status());
     }
+    if (resolved.ok()) {
+      for (const auto& addr : *resolved) {
+        results->push_back(
+            grpc_event_engine::experimental::CreateResolvedAddress(addr));
+      }
+    }
+    GRPC_RETURN_IF_ERROR(results.status());
     // Create a listener for each resolved address.
-    for (auto& addr : *resolved_or) {
+    for (EventEngine::ResolvedAddress& addr : *results) {
       // If address has a wildcard port (0), use the same port as a previous
       // listener.
-      if (*port_num != -1 && grpc_sockaddr_get_port(&addr) == 0) {
-        grpc_sockaddr_set_port(&addr, *port_num);
+      if (*port_num != -1 &&
+          grpc_event_engine::experimental::ResolvedAddressGetPort(addr) == 0) {
+        grpc_event_engine::experimental::ResolvedAddressSetPort(addr,
+                                                                *port_num);
       }
       int port_temp = -1;
-      error = Chttp2ServerListener::Create(server, &addr, args, args_modifier,
+      error = Chttp2ServerListener::Create(server, addr, args, args_modifier,
                                            &port_temp);
       if (!error.ok()) {
         error_list.push_back(error);
@@ -999,17 +1041,17 @@ grpc_error_handle Chttp2ServerAddPort(Server* server, const char* addr,
         }
       }
     }
-    if (error_list.size() == resolved_or->size()) {
+    if (error_list.size() == results->size()) {
       std::string msg = absl::StrFormat(
           "No address added out of total %" PRIuPTR " resolved for '%s'",
-          resolved_or->size(), addr);
+          results->size(), addr);
       return GRPC_ERROR_CREATE_REFERENCING(msg.c_str(), error_list.data(),
                                            error_list.size());
     } else if (!error_list.empty()) {
-      std::string msg = absl::StrFormat(
-          "Only %" PRIuPTR " addresses added out of total %" PRIuPTR
-          " resolved",
-          resolved_or->size() - error_list.size(), resolved_or->size());
+      std::string msg =
+          absl::StrFormat("Only %" PRIuPTR
+                          " addresses added out of total %" PRIuPTR " resolved",
+                          results->size() - error_list.size(), results->size());
       error = GRPC_ERROR_CREATE_REFERENCING(msg.c_str(), error_list.data(),
                                             error_list.size());
       LOG(INFO) << "WARNING: " << StatusToString(error);

src/core/lib/event_engine/resolved_address.cc

@@ -48,6 +48,9 @@ EventEngine::ResolvedAddress CreateResolvedAddress(
 
 grpc_resolved_address CreateGRPCResolvedAddress(
     const EventEngine::ResolvedAddress& ra) {
+  static_assert(
+      GRPC_MAX_SOCKADDR_SIZE == EventEngine::ResolvedAddress::MAX_SIZE_BYTES,
+      "size should match");
   grpc_resolved_address grpc_addr;
   memset(&grpc_addr, 0, sizeof(grpc_resolved_address));
   memcpy(grpc_addr.addr, ra.address(), ra.size());

src/core/lib/event_engine/utils.cc

@@ -20,6 +20,7 @@
 #include <algorithm>
 
 #include "absl/strings/str_cat.h"
+#include "src/core/util/notification.h"
 #include "src/core/util/time.h"
 
 namespace grpc_event_engine {
@@ -38,5 +39,20 @@ grpc_core::Timestamp ToTimestamp(grpc_core::Timestamp now,
          grpc_core::Duration::Milliseconds(1);
 }
 
+absl::StatusOr<std::vector<EventEngine::ResolvedAddress>>
+LookupHostnameBlocking(EventEngine::DNSResolver* dns_resolver,
+                       absl::string_view name, absl::string_view default_port) {
+  absl::StatusOr<std::vector<EventEngine::ResolvedAddress>> results;
+  grpc_core::Notification done;
+  dns_resolver->LookupHostname(
+      [&](absl::StatusOr<std::vector<EventEngine::ResolvedAddress>> addresses) {
+        results = std::move(addresses);
+        done.Notify();
+      },
+      name, default_port);
+  done.WaitForNotification();
+  return results;
+}
+
 }  // namespace experimental
 }  // namespace grpc_event_engine

src/core/lib/event_engine/utils.h

@@ -19,7 +19,10 @@
 #include <stdint.h>
 
 #include <string>
+#include <vector>
 
+#include "absl/status/statusor.h"
+#include "absl/strings/string_view.h"
 #include "src/core/util/time.h"
 
 namespace grpc_event_engine {
@@ -36,6 +39,10 @@ std::string HandleToString(const Handle& handle) {
 grpc_core::Timestamp ToTimestamp(grpc_core::Timestamp now,
                                  EventEngine::Duration delta);
 
+absl::StatusOr<std::vector<EventEngine::ResolvedAddress>>
+LookupHostnameBlocking(EventEngine::DNSResolver* dns_resolver,
+                       absl::string_view name, absl::string_view default_port);
+
 }  // namespace experimental
 }  // namespace grpc_event_engine
 

src/core/lib/experiments/experiments.cc

@@ -41,6 +41,11 @@ const char* const additional_constraints_event_engine_client = "{}";
 const char* const description_event_engine_dns =
     "If set, use EventEngine DNSResolver for client channel resolution";
 const char* const additional_constraints_event_engine_dns = "{}";
+const char* const description_event_engine_dns_non_client_channel =
+    "If set, use EventEngine DNSResolver in other places besides client "
+    "channel.";
+const char* const additional_constraints_event_engine_dns_non_client_channel =
+    "{}";
 const char* const description_event_engine_listener =
     "Use EventEngine listeners instead of iomgr's grpc_tcp_server";
 const char* const additional_constraints_event_engine_listener = "{}";
@@ -122,6 +127,10 @@ const ExperimentMetadata g_experiment_metadata[] = {
      additional_constraints_event_engine_client, nullptr, 0, false, true},
     {"event_engine_dns", description_event_engine_dns,
      additional_constraints_event_engine_dns, nullptr, 0, false, false},
+    {"event_engine_dns_non_client_channel",
+     description_event_engine_dns_non_client_channel,
+     additional_constraints_event_engine_dns_non_client_channel, nullptr, 0,
+     false, false},
     {"event_engine_listener", description_event_engine_listener,
      additional_constraints_event_engine_listener, nullptr, 0, false, true},
     {"free_large_allocator", description_free_large_allocator,
@@ -188,6 +197,11 @@ const char* const additional_constraints_event_engine_client = "{}";
 const char* const description_event_engine_dns =
     "If set, use EventEngine DNSResolver for client channel resolution";
 const char* const additional_constraints_event_engine_dns = "{}";
+const char* const description_event_engine_dns_non_client_channel =
+    "If set, use EventEngine DNSResolver in other places besides client "
+    "channel.";
+const char* const additional_constraints_event_engine_dns_non_client_channel =
+    "{}";
 const char* const description_event_engine_listener =
     "Use EventEngine listeners instead of iomgr's grpc_tcp_server";
 const char* const additional_constraints_event_engine_listener = "{}";
@@ -269,6 +283,10 @@ const ExperimentMetadata g_experiment_metadata[] = {
      additional_constraints_event_engine_client, nullptr, 0, true, true},
     {"event_engine_dns", description_event_engine_dns,
      additional_constraints_event_engine_dns, nullptr, 0, true, false},
+    {"event_engine_dns_non_client_channel",
+     description_event_engine_dns_non_client_channel,
+     additional_constraints_event_engine_dns_non_client_channel, nullptr, 0,
+     false, false},
     {"event_engine_listener", description_event_engine_listener,
      additional_constraints_event_engine_listener, nullptr, 0, true, true},
     {"free_large_allocator", description_free_large_allocator,
@@ -335,6 +353,11 @@ const char* const additional_constraints_event_engine_client = "{}";
 const char* const description_event_engine_dns =
     "If set, use EventEngine DNSResolver for client channel resolution";
 const char* const additional_constraints_event_engine_dns = "{}";
+const char* const description_event_engine_dns_non_client_channel =
+    "If set, use EventEngine DNSResolver in other places besides client "
+    "channel.";
+const char* const additional_constraints_event_engine_dns_non_client_channel =
+    "{}";
 const char* const description_event_engine_listener =
     "Use EventEngine listeners instead of iomgr's grpc_tcp_server";
 const char* const additional_constraints_event_engine_listener = "{}";
@@ -416,6 +439,10 @@ const ExperimentMetadata g_experiment_metadata[] = {
      additional_constraints_event_engine_client, nullptr, 0, true, true},
     {"event_engine_dns", description_event_engine_dns,
      additional_constraints_event_engine_dns, nullptr, 0, true, false},
+    {"event_engine_dns_non_client_channel",
+     description_event_engine_dns_non_client_channel,
+     additional_constraints_event_engine_dns_non_client_channel, nullptr, 0,
+     false, false},
     {"event_engine_listener", description_event_engine_listener,
      additional_constraints_event_engine_listener, nullptr, 0, true, true},
     {"free_large_allocator", description_free_large_allocator,

src/core/lib/experiments/experiments.h

@@ -65,6 +65,7 @@ inline bool IsClientPrivacyEnabled() { return false; }
 inline bool IsEventEngineApplicationCallbacksEnabled() { return true; }
 inline bool IsEventEngineClientEnabled() { return false; }
 inline bool IsEventEngineDnsEnabled() { return false; }
+inline bool IsEventEngineDnsNonClientChannelEnabled() { return false; }
 inline bool IsEventEngineListenerEnabled() { return false; }
 inline bool IsFreeLargeAllocatorEnabled() { return false; }
 inline bool IsLocalConnectorSecureEnabled() { return false; }
@@ -98,6 +99,7 @@ inline bool IsEventEngineApplicationCallbacksEnabled() { return true; }
 inline bool IsEventEngineClientEnabled() { return true; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_DNS
 inline bool IsEventEngineDnsEnabled() { return true; }
+inline bool IsEventEngineDnsNonClientChannelEnabled() { return false; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_LISTENER
 inline bool IsEventEngineListenerEnabled() { return true; }
 inline bool IsFreeLargeAllocatorEnabled() { return false; }
@@ -132,6 +134,7 @@ inline bool IsEventEngineApplicationCallbacksEnabled() { return true; }
 inline bool IsEventEngineClientEnabled() { return true; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_DNS
 inline bool IsEventEngineDnsEnabled() { return true; }
+inline bool IsEventEngineDnsNonClientChannelEnabled() { return false; }
 #define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_LISTENER
 inline bool IsEventEngineListenerEnabled() { return true; }
 inline bool IsFreeLargeAllocatorEnabled() { return false; }
@@ -165,6 +168,7 @@ enum ExperimentIds {
   kExperimentIdEventEngineApplicationCallbacks,
   kExperimentIdEventEngineClient,
   kExperimentIdEventEngineDns,
+  kExperimentIdEventEngineDnsNonClientChannel,
   kExperimentIdEventEngineListener,
   kExperimentIdFreeLargeAllocator,
   kExperimentIdLocalConnectorSecure,
@@ -208,6 +212,10 @@ inline bool IsEventEngineClientEnabled() {
 inline bool IsEventEngineDnsEnabled() {
   return IsExperimentEnabled<kExperimentIdEventEngineDns>();
 }
+#define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_DNS_NON_CLIENT_CHANNEL
+inline bool IsEventEngineDnsNonClientChannelEnabled() {
+  return IsExperimentEnabled<kExperimentIdEventEngineDnsNonClientChannel>();
+}
 #define GRPC_EXPERIMENT_IS_INCLUDED_EVENT_ENGINE_LISTENER
 inline bool IsEventEngineListenerEnabled() {
   return IsExperimentEnabled<kExperimentIdEventEngineListener>();

src/core/lib/experiments/experiments.yaml

@@ -77,6 +77,14 @@
   test_tags: ["cancel_ares_query_test", "resolver_component_tests_runner_invoker"]
   allow_in_fuzzing_config: false
   uses_polling: true
+- name: event_engine_dns_non_client_channel
+  description:
+    If set, use EventEngine DNSResolver in other places besides client channel.
+  expiry: 2025/03/01
+  owner: yijiem@google.com
+  test_tags: ["core_end2end_test"]
+  allow_in_fuzzing_config: false
+  uses_polling: true
 - name: event_engine_listener
   description: Use EventEngine listeners instead of iomgr's grpc_tcp_server
   expiry: 2025/03/01