Imported Upstream version 1.41.0
[platform/upstream/grpc.git] / src / core / ext / transport / chttp2 / server / chttp2_server.cc
index 5e9cd77..8d330ae 100644 (file)
 #include <limits.h>
 #include <string.h>
 
+#include <vector>
+
+#include "absl/strings/match.h"
+#include "absl/strings/str_cat.h"
+#include "absl/strings/str_format.h"
+
 #include <grpc/grpc.h>
 #include <grpc/impl/codegen/grpc_types.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
-#include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 
 #include "src/core/ext/filters/http/server/http_server_filter.h"
 #include "src/core/ext/transport/chttp2/transport/chttp2_transport.h"
 #include "src/core/ext/transport/chttp2/transport/internal.h"
+#include "src/core/lib/address_utils/sockaddr_utils.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/handshaker.h"
-#include "src/core/lib/channel/handshaker_registry.h"
+#include "src/core/lib/config/core_configuration.h"
+#include "src/core/lib/gprpp/ref_counted.h"
+#include "src/core/lib/gprpp/ref_counted_ptr.h"
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/resolve_address.h"
 #include "src/core/lib/iomgr/resource_quota.h"
 #include "src/core/lib/iomgr/tcp_server.h"
+#include "src/core/lib/iomgr/unix_sockets_posix.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/server.h"
 
-typedef struct {
-  grpc_server* server;
-  grpc_tcp_server* tcp_server;
-  grpc_channel_args* args;
-  gpr_mu mu;
-  bool shutdown;
-  grpc_closure tcp_server_shutdown_complete;
-  grpc_closure* server_destroy_listener_done;
-  grpc_core::HandshakeManager* pending_handshake_mgrs;
-  grpc_core::RefCountedPtr<grpc_core::channelz::ListenSocketNode>
-      channelz_listen_socket;
-} server_state;
-
-typedef struct {
-  gpr_refcount refs;
-  server_state* svr_state;
-  grpc_pollset* accepting_pollset;
-  grpc_tcp_server_acceptor* acceptor;
-  grpc_core::RefCountedPtr<grpc_core::HandshakeManager> handshake_mgr;
-  // State for enforcing handshake timeout on receiving HTTP/2 settings.
-  grpc_chttp2_transport* transport;
-  grpc_millis deadline;
-  grpc_timer timer;
-  grpc_closure on_timeout;
-  grpc_closure on_receive_settings;
-  grpc_pollset_set* interested_parties;
-} server_connection_state;
-
-static void server_connection_state_unref(
-    server_connection_state* connection_state) {
-  if (gpr_unref(&connection_state->refs)) {
-    if (connection_state->transport != nullptr) {
-      GRPC_CHTTP2_UNREF_TRANSPORT(connection_state->transport,
-                                  "receive settings timeout");
+namespace grpc_core {
+namespace {
+
+const char kUnixUriPrefix[] = "unix:";
+const char kUnixAbstractUriPrefix[] = "unix-abstract:";
+
+class Chttp2ServerListener : public Server::ListenerInterface {
+ public:
+  static grpc_error_handle Create(Server* server, grpc_resolved_address* addr,
+                                  grpc_channel_args* args,
+                                  Chttp2ServerArgsModifier args_modifier,
+                                  int* port_num);
+
+  static grpc_error_handle CreateWithAcceptor(
+      Server* server, const char* name, grpc_channel_args* args,
+      Chttp2ServerArgsModifier args_modifier);
+
+  // Do not instantiate directly.  Use one of the factory methods above.
+  Chttp2ServerListener(Server* server, grpc_channel_args* args,
+                       Chttp2ServerArgsModifier args_modifier,
+                       grpc_resource_quota* resource_quota);
+  ~Chttp2ServerListener() override;
+
+  void Start(Server* server,
+             const std::vector<grpc_pollset*>* pollsets) override;
+
+  channelz::ListenSocketNode* channelz_listen_socket_node() const override {
+    return channelz_listen_socket_.get();
+  }
+
+  void SetOnDestroyDone(grpc_closure* on_destroy_done) override;
+
+  void Orphan() override;
+
+ private:
+  class ConfigFetcherWatcher
+      : public grpc_server_config_fetcher::WatcherInterface {
+   public:
+    explicit ConfigFetcherWatcher(RefCountedPtr<Chttp2ServerListener> listener)
+        : listener_(std::move(listener)) {}
+
+    void UpdateConnectionManager(
+        RefCountedPtr<grpc_server_config_fetcher::ConnectionManager>
+            connection_manager) override;
+
+    void StopServing() override;
+
+   private:
+    RefCountedPtr<Chttp2ServerListener> listener_;
+  };
+
+  class ActiveConnection : public InternallyRefCounted<ActiveConnection> {
+   public:
+    class HandshakingState : public InternallyRefCounted<HandshakingState> {
+     public:
+      HandshakingState(RefCountedPtr<ActiveConnection> connection_ref,
+                       grpc_pollset* accepting_pollset,
+                       grpc_tcp_server_acceptor* acceptor,
+                       grpc_channel_args* args,
+                       grpc_resource_user* channel_resource_user);
+
+      ~HandshakingState() override;
+
+      void Orphan() override;
+
+      void Start(grpc_endpoint* endpoint, grpc_channel_args* args);
+
+      // Needed to be able to grab an external ref in ActiveConnection::Start()
+      using InternallyRefCounted<HandshakingState>::Ref;
+
+     private:
+      static void OnTimeout(void* arg, grpc_error_handle error);
+      static void OnReceiveSettings(void* arg, grpc_error_handle /* error */);
+      static void OnHandshakeDone(void* arg, grpc_error_handle error);
+      RefCountedPtr<ActiveConnection> const connection_;
+      grpc_pollset* const accepting_pollset_;
+      grpc_tcp_server_acceptor* acceptor_;
+      RefCountedPtr<HandshakeManager> handshake_mgr_
+          ABSL_GUARDED_BY(&connection_->mu_);
+      // State for enforcing handshake timeout on receiving HTTP/2 settings.
+      grpc_millis const deadline_;
+      grpc_timer timer_ ABSL_GUARDED_BY(&connection_->mu_);
+      grpc_closure on_timeout_ ABSL_GUARDED_BY(&connection_->mu_);
+      grpc_closure on_receive_settings_ ABSL_GUARDED_BY(&connection_->mu_);
+      grpc_pollset_set* const interested_parties_;
+      grpc_resource_user* channel_resource_user_;
+    };
+
+    ActiveConnection(grpc_pollset* accepting_pollset,
+                     grpc_tcp_server_acceptor* acceptor,
+                     grpc_channel_args* args,
+                     grpc_resource_user* channel_resource_user);
+    ~ActiveConnection() override;
+
+    void Orphan() override;
+
+    void SendGoAway();
+
+    void Start(RefCountedPtr<Chttp2ServerListener> listener,
+               grpc_endpoint* endpoint, grpc_channel_args* args);
+
+    // Needed to be able to grab an external ref in
+    // Chttp2ServerListener::OnAccept()
+    using InternallyRefCounted<ActiveConnection>::Ref;
+
+   private:
+    static void OnClose(void* arg, grpc_error_handle error);
+
+    RefCountedPtr<Chttp2ServerListener> listener_;
+    Mutex mu_ ABSL_ACQUIRED_AFTER(&listener_->mu_);
+    // Set by HandshakingState before the handshaking begins and reset when
+    // handshaking is done.
+    OrphanablePtr<HandshakingState> handshaking_state_ ABSL_GUARDED_BY(&mu_);
+    // Set by HandshakingState when handshaking is done and a valid transport is
+    // created.
+    grpc_chttp2_transport* transport_ ABSL_GUARDED_BY(&mu_) = nullptr;
+    grpc_closure on_close_;
+    bool shutdown_ ABSL_GUARDED_BY(&mu_) = false;
+  };
+
+  // To allow access to RefCounted<> like interface.
+  friend class RefCountedPtr<Chttp2ServerListener>;
+
+  // Should only be called once so as to start the TCP server.
+  void StartListening();
+
+  static void OnAccept(void* arg, grpc_endpoint* tcp,
+                       grpc_pollset* accepting_pollset,
+                       grpc_tcp_server_acceptor* acceptor);
+
+  static void TcpServerShutdownComplete(void* arg, grpc_error_handle error);
+
+  static void DestroyListener(Server* /*server*/, void* arg,
+                              grpc_closure* destroy_done);
+
+  // The interface required by RefCountedPtr<> has been manually implemented
+  // here to take a ref on tcp_server_ instead. Note that, the handshaker needs
+  // tcp_server_ to exist for the lifetime of the handshake since it's needed by
+  // acceptor. Sharing refs between the listener and tcp_server_ is just an
+  // optimization to avoid taking additional refs on the listener, since
+  // TcpServerShutdownComplete already holds a ref to the listener.
+  void IncrementRefCount() { grpc_tcp_server_ref(tcp_server_); }
+  void IncrementRefCount(const DebugLocation& /* location */,
+                         const char* /* reason */) {
+    IncrementRefCount();
+  }
+
+  RefCountedPtr<Chttp2ServerListener> Ref() GRPC_MUST_USE_RESULT {
+    IncrementRefCount();
+    return RefCountedPtr<Chttp2ServerListener>(this);
+  }
+  RefCountedPtr<Chttp2ServerListener> Ref(const DebugLocation& /* location */,
+                                          const char* /* reason */)
+      GRPC_MUST_USE_RESULT {
+    return Ref();
+  }
+
+  void Unref() { grpc_tcp_server_unref(tcp_server_); }
+  void Unref(const DebugLocation& /* location */, const char* /* reason */) {
+    Unref();
+  }
+
+  Server* const server_;
+  grpc_tcp_server* tcp_server_;
+  grpc_resolved_address resolved_address_;
+  Chttp2ServerArgsModifier const args_modifier_;
+  ConfigFetcherWatcher* config_fetcher_watcher_ = nullptr;
+  Mutex channel_args_mu_;
+  grpc_channel_args* args_ ABSL_GUARDED_BY(channel_args_mu_);
+  RefCountedPtr<grpc_server_config_fetcher::ConnectionManager>
+      connection_manager_ ABSL_GUARDED_BY(channel_args_mu_);
+  Mutex mu_;
+  // Signals whether grpc_tcp_server_start() has been called.
+  bool started_ ABSL_GUARDED_BY(mu_) = false;
+  // Signals whether grpc_tcp_server_start() has completed.
+  CondVar started_cv_ ABSL_GUARDED_BY(mu_);
+  // Signals whether new requests/connections are to be accepted.
+  bool is_serving_ ABSL_GUARDED_BY(mu_) = false;
+  // Signals whether the application has triggered shutdown.
+  bool shutdown_ ABSL_GUARDED_BY(mu_) = false;
+  std::map<ActiveConnection*, OrphanablePtr<ActiveConnection>> connections_
+      ABSL_GUARDED_BY(mu_);
+  grpc_closure tcp_server_shutdown_complete_ ABSL_GUARDED_BY(mu_);
+  grpc_closure* on_destroy_done_ ABSL_GUARDED_BY(mu_) = nullptr;
+  RefCountedPtr<channelz::ListenSocketNode> channelz_listen_socket_;
+  grpc_resource_quota* resource_quota_;
+};
+
+//
+// Chttp2ServerListener::ConfigFetcherWatcher
+//
+
+void Chttp2ServerListener::ConfigFetcherWatcher::UpdateConnectionManager(
+    RefCountedPtr<grpc_server_config_fetcher::ConnectionManager>
+        connection_manager) {
+  RefCountedPtr<grpc_server_config_fetcher::ConnectionManager>
+      connection_manager_to_destroy;
+  {
+    MutexLock lock(&listener_->channel_args_mu_);
+    connection_manager_to_destroy = listener_->connection_manager_;
+    listener_->connection_manager_ = std::move(connection_manager);
+  }
+  {
+    MutexLock lock(&listener_->mu_);
+    if (listener_->shutdown_) {
+      return;
+    }
+    listener_->is_serving_ = true;
+    if (listener_->started_) return;
+  }
+  int port_temp;
+  grpc_error_handle error = grpc_tcp_server_add_port(
+      listener_->tcp_server_, &listener_->resolved_address_, &port_temp);
+  if (error != GRPC_ERROR_NONE) {
+    GRPC_ERROR_UNREF(error);
+    gpr_log(GPR_ERROR, "Error adding port to server: %s",
+            grpc_error_std_string(error).c_str());
+    // TODO(yashykt): We wouldn't need to assert here if we bound to the
+    // port earlier during AddPort.
+    GPR_ASSERT(0);
+  }
+  listener_->StartListening();
+  {
+    MutexLock lock(&listener_->mu_);
+    listener_->started_ = true;
+    listener_->started_cv_.SignalAll();
+  }
+}
+
+void Chttp2ServerListener::ConfigFetcherWatcher::StopServing() {
+  std::map<ActiveConnection*, OrphanablePtr<ActiveConnection>> connections;
+  {
+    MutexLock lock(&listener_->mu_);
+    listener_->is_serving_ = false;
+    connections = std::move(listener_->connections_);
+  }
+  // Send GOAWAYs on the transports so that they disconnected when existing RPCs
+  // finish.
+  for (auto& connection : connections) {
+    connection.first->SendGoAway();
+  }
+}
+
+//
+// Chttp2ServerListener::ActiveConnection::HandshakingState
+//
+
+grpc_millis GetConnectionDeadline(const grpc_channel_args* args) {
+  int timeout_ms =
+      grpc_channel_args_find_integer(args, GRPC_ARG_SERVER_HANDSHAKE_TIMEOUT_MS,
+                                     {120 * GPR_MS_PER_SEC, 1, INT_MAX});
+  return ExecCtx::Get()->Now() + timeout_ms;
+}
+
+Chttp2ServerListener::ActiveConnection::HandshakingState::HandshakingState(
+    RefCountedPtr<ActiveConnection> connection_ref,
+    grpc_pollset* accepting_pollset, grpc_tcp_server_acceptor* acceptor,
+    grpc_channel_args* args, grpc_resource_user* channel_resource_user)
+    : connection_(std::move(connection_ref)),
+      accepting_pollset_(accepting_pollset),
+      acceptor_(acceptor),
+      handshake_mgr_(MakeRefCounted<HandshakeManager>()),
+      deadline_(GetConnectionDeadline(args)),
+      interested_parties_(grpc_pollset_set_create()),
+      channel_resource_user_(channel_resource_user) {
+  grpc_pollset_set_add_pollset(interested_parties_, accepting_pollset_);
+  CoreConfiguration::Get().handshaker_registry().AddHandshakers(
+      HANDSHAKER_SERVER, args, interested_parties_, handshake_mgr_.get());
+}
+
+Chttp2ServerListener::ActiveConnection::HandshakingState::~HandshakingState() {
+  grpc_pollset_set_del_pollset(interested_parties_, accepting_pollset_);
+  grpc_pollset_set_destroy(interested_parties_);
+  if (channel_resource_user_ != nullptr) {
+    grpc_resource_user_unref(channel_resource_user_);
+  }
+  gpr_free(acceptor_);
+}
+
+void Chttp2ServerListener::ActiveConnection::HandshakingState::Orphan() {
+  {
+    MutexLock lock(&connection_->mu_);
+    if (handshake_mgr_ != nullptr) {
+      handshake_mgr_->Shutdown(
+          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Listener stopped serving."));
     }
-    grpc_pollset_set_del_pollset(connection_state->interested_parties,
-                                 connection_state->accepting_pollset);
-    grpc_pollset_set_destroy(connection_state->interested_parties);
-    gpr_free(connection_state);
   }
+  Unref();
 }
 
-static void on_timeout(void* arg, grpc_error* error) {
-  server_connection_state* connection_state =
-      static_cast<server_connection_state*>(arg);
+void Chttp2ServerListener::ActiveConnection::HandshakingState::Start(
+    grpc_endpoint* endpoint, grpc_channel_args* args) {
+  Ref().release();  // Held by OnHandshakeDone
+  RefCountedPtr<HandshakeManager> handshake_mgr;
+  {
+    MutexLock lock(&connection_->mu_);
+    if (handshake_mgr_ == nullptr) return;
+    handshake_mgr = handshake_mgr_;
+  }
+  handshake_mgr->DoHandshake(endpoint, args, deadline_, acceptor_,
+                             OnHandshakeDone, this);
+}
+
+void Chttp2ServerListener::ActiveConnection::HandshakingState::OnTimeout(
+    void* arg, grpc_error_handle error) {
+  HandshakingState* self = static_cast<HandshakingState*>(arg);
   // Note that we may be called with GRPC_ERROR_NONE when the timer fires
   // or with an error indicating that the timer system is being shut down.
   if (error != GRPC_ERROR_CANCELLED) {
     grpc_transport_op* op = grpc_make_transport_op(nullptr);
     op->disconnect_with_error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
         "Did not receive HTTP/2 settings before handshake timeout");
-    grpc_transport_perform_op(&connection_state->transport->base, op);
+    grpc_chttp2_transport* transport = nullptr;
+    {
+      MutexLock lock(&self->connection_->mu_);
+      transport = self->connection_->transport_;
+    }
+    grpc_transport_perform_op(&transport->base, op);
   }
-  server_connection_state_unref(connection_state);
+  self->Unref();
 }
 
-static void on_receive_settings(void* arg, grpc_error* error) {
-  server_connection_state* connection_state =
-      static_cast<server_connection_state*>(arg);
-  if (error == GRPC_ERROR_NONE) {
-    grpc_timer_cancel(&connection_state->timer);
-  }
-  server_connection_state_unref(connection_state);
+void Chttp2ServerListener::ActiveConnection::HandshakingState::
+    OnReceiveSettings(void* arg, grpc_error_handle /* error */) {
+  HandshakingState* self = static_cast<HandshakingState*>(arg);
+  grpc_timer_cancel(&self->timer_);
+  self->Unref();
 }
 
-static void on_handshake_done(void* arg, grpc_error* error) {
-  auto* args = static_cast<grpc_core::HandshakerArgs*>(arg);
-  server_connection_state* connection_state =
-      static_cast<server_connection_state*>(args->user_data);
-  gpr_mu_lock(&connection_state->svr_state->mu);
-  grpc_resource_user* resource_user = grpc_server_get_default_resource_user(
-      connection_state->svr_state->server);
-  if (error != GRPC_ERROR_NONE || connection_state->svr_state->shutdown) {
-    const char* error_str = grpc_error_string(error);
-    gpr_log(GPR_DEBUG, "Handshaking failed: %s", error_str);
-    grpc_resource_user* resource_user = grpc_server_get_default_resource_user(
-        connection_state->svr_state->server);
-    if (resource_user != nullptr) {
-      grpc_resource_user_free(resource_user, GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
+void Chttp2ServerListener::ActiveConnection::HandshakingState::OnHandshakeDone(
+    void* arg, grpc_error_handle error) {
+  auto* args = static_cast<HandshakerArgs*>(arg);
+  HandshakingState* self = static_cast<HandshakingState*>(args->user_data);
+  OrphanablePtr<HandshakingState> handshaking_state_ref;
+  RefCountedPtr<HandshakeManager> handshake_mgr;
+  bool cleanup_connection = false;
+  {
+    MutexLock connection_lock(&self->connection_->mu_);
+    if (error != GRPC_ERROR_NONE || self->connection_->shutdown_) {
+      std::string error_str = grpc_error_std_string(error);
+      gpr_log(GPR_DEBUG, "Handshaking failed: %s", error_str.c_str());
+      cleanup_connection = true;
+      if (error == GRPC_ERROR_NONE && args->endpoint != nullptr) {
+        // We were shut down or stopped serving after handshaking completed
+        // successfully, so destroy the endpoint here.
+        // TODO(ctiller): It is currently necessary to shutdown endpoints
+        // before destroying them, even if we know that there are no
+        // pending read/write callbacks.  This should be fixed, at which
+        // point this can be removed.
+        grpc_endpoint_shutdown(args->endpoint, GRPC_ERROR_NONE);
+        grpc_endpoint_destroy(args->endpoint);
+        grpc_channel_args_destroy(args->args);
+        grpc_slice_buffer_destroy_internal(args->read_buffer);
+        gpr_free(args->read_buffer);
+      }
+    } else {
+      // If the handshaking succeeded but there is no endpoint, then the
+      // handshaker may have handed off the connection to some external
+      // code, so we can just clean up here without creating a transport.
+      if (args->endpoint != nullptr) {
+        grpc_transport* transport = grpc_create_chttp2_transport(
+            args->args, args->endpoint, false,
+            grpc_resource_user_create(
+                self->connection_->listener_->resource_quota_,
+                absl::StrCat(grpc_endpoint_get_peer(args->endpoint),
+                             ":chttp2_server_transport")));
+        grpc_error_handle channel_init_err =
+            self->connection_->listener_->server_->SetupTransport(
+                transport, self->accepting_pollset_, args->args,
+                grpc_chttp2_transport_get_socket_node(transport),
+                self->channel_resource_user_, GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
+        self->channel_resource_user_ = nullptr;
+        if (channel_init_err == GRPC_ERROR_NONE) {
+          // Use notify_on_receive_settings callback to enforce the
+          // handshake deadline.
+          // Note: The reinterpret_cast<>s here are safe, because
+          // grpc_chttp2_transport is a C-style extension of
+          // grpc_transport, so this is morally equivalent of a
+          // static_cast<> to a derived class.
+          // TODO(roth): Change to static_cast<> when we C++-ify the
+          // transport API.
+          self->connection_->transport_ =
+              reinterpret_cast<grpc_chttp2_transport*>(transport);
+          GRPC_CHTTP2_REF_TRANSPORT(self->connection_->transport_,
+                                    "ActiveConnection");  // Held by connection_
+          self->Ref().release();  // Held by OnReceiveSettings().
+          GRPC_CLOSURE_INIT(&self->on_receive_settings_, OnReceiveSettings,
+                            self, grpc_schedule_on_exec_ctx);
+          // If the listener has been configured with a config fetcher, we need
+          // to watch on the transport being closed so that we can an updated
+          // list of active connections.
+          grpc_closure* on_close = nullptr;
+          if (self->connection_->listener_->config_fetcher_watcher_ !=
+              nullptr) {
+            // Refs helds by OnClose()
+            self->connection_->Ref().release();
+            on_close = &self->connection_->on_close_;
+          } else {
+            // Remove the connection from the connections_ map since OnClose()
+            // will not be invoked when a config fetcher is set.
+            cleanup_connection = true;
+          }
+          grpc_chttp2_transport_start_reading(transport, args->read_buffer,
+                                              &self->on_receive_settings_,
+                                              on_close);
+          grpc_channel_args_destroy(args->args);
+          self->Ref().release();  // Held by OnTimeout().
+          GRPC_CLOSURE_INIT(&self->on_timeout_, OnTimeout, self,
+                            grpc_schedule_on_exec_ctx);
+          grpc_timer_init(&self->timer_, self->deadline_, &self->on_timeout_);
+        } else {
+          // Failed to create channel from transport. Clean up.
+          gpr_log(GPR_ERROR, "Failed to create channel: %s",
+                  grpc_error_std_string(channel_init_err).c_str());
+          GRPC_ERROR_UNREF(channel_init_err);
+          grpc_transport_destroy(transport);
+          grpc_slice_buffer_destroy_internal(args->read_buffer);
+          gpr_free(args->read_buffer);
+          cleanup_connection = true;
+          grpc_channel_args_destroy(args->args);
+        }
+      } else {
+        cleanup_connection = true;
+      }
     }
-    if (error == GRPC_ERROR_NONE && args->endpoint != nullptr) {
-      // We were shut down after handshaking completed successfully, so
-      // destroy the endpoint here.
-      // TODO(ctiller): It is currently necessary to shutdown endpoints
-      // before destroying them, even if we know that there are no
-      // pending read/write callbacks.  This should be fixed, at which
-      // point this can be removed.
-      grpc_endpoint_shutdown(args->endpoint, GRPC_ERROR_NONE);
-      grpc_endpoint_destroy(args->endpoint);
-      grpc_channel_args_destroy(args->args);
-      grpc_slice_buffer_destroy_internal(args->read_buffer);
-      gpr_free(args->read_buffer);
+    // Since the handshake manager is done, the connection no longer needs to
+    // shutdown the handshake when the listener needs to stop serving.
+    // Avoid calling the destructor of HandshakeManager and HandshakingState
+    // from within the critical region.
+    handshake_mgr = std::move(self->handshake_mgr_);
+    handshaking_state_ref = std::move(self->connection_->handshaking_state_);
+  }
+  gpr_free(self->acceptor_);
+  self->acceptor_ = nullptr;
+  OrphanablePtr<ActiveConnection> connection;
+  if (self->channel_resource_user_ != nullptr) {
+    grpc_resource_user_free(self->channel_resource_user_,
+                            GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
+  }
+  if (cleanup_connection) {
+    MutexLock listener_lock(&self->connection_->listener_->mu_);
+    auto it = self->connection_->listener_->connections_.find(
+        self->connection_.get());
+    if (it != self->connection_->listener_->connections_.end()) {
+      connection = std::move(it->second);
+      self->connection_->listener_->connections_.erase(it);
     }
-  } else {
-    // If the handshaking succeeded but there is no endpoint, then the
-    // handshaker may have handed off the connection to some external
-    // code, so we can just clean up here without creating a transport.
-    if (args->endpoint != nullptr) {
-      grpc_transport* transport = grpc_create_chttp2_transport(
-          args->args, args->endpoint, false, resource_user);
-      grpc_server_setup_transport(
-          connection_state->svr_state->server, transport,
-          connection_state->accepting_pollset, args->args,
-          grpc_chttp2_transport_get_socket_node(transport), resource_user);
-      // Use notify_on_receive_settings callback to enforce the
-      // handshake deadline.
-      connection_state->transport =
-          reinterpret_cast<grpc_chttp2_transport*>(transport);
-      gpr_ref(&connection_state->refs);
-      GRPC_CLOSURE_INIT(&connection_state->on_receive_settings,
-                        on_receive_settings, connection_state,
-                        grpc_schedule_on_exec_ctx);
-      grpc_chttp2_transport_start_reading(
-          transport, args->read_buffer, &connection_state->on_receive_settings);
-      grpc_channel_args_destroy(args->args);
-      gpr_ref(&connection_state->refs);
-      GRPC_CHTTP2_REF_TRANSPORT((grpc_chttp2_transport*)transport,
-                                "receive settings timeout");
-      GRPC_CLOSURE_INIT(&connection_state->on_timeout, on_timeout,
-                        connection_state, grpc_schedule_on_exec_ctx);
-      grpc_timer_init(&connection_state->timer, connection_state->deadline,
-                      &connection_state->on_timeout);
+  }
+  self->Unref();
+}
+
+//
+// Chttp2ServerListener::ActiveConnection
+//
+
+Chttp2ServerListener::ActiveConnection::ActiveConnection(
+    grpc_pollset* accepting_pollset, grpc_tcp_server_acceptor* acceptor,
+    grpc_channel_args* args, grpc_resource_user* channel_resource_user)
+    : handshaking_state_(MakeOrphanable<HandshakingState>(
+          Ref(), accepting_pollset, acceptor, args, channel_resource_user)) {
+  GRPC_CLOSURE_INIT(&on_close_, ActiveConnection::OnClose, this,
+                    grpc_schedule_on_exec_ctx);
+}
+
+Chttp2ServerListener::ActiveConnection::~ActiveConnection() {
+  if (transport_ != nullptr) {
+    GRPC_CHTTP2_UNREF_TRANSPORT(transport_, "ActiveConnection");
+  }
+}
+
+void Chttp2ServerListener::ActiveConnection::Orphan() {
+  OrphanablePtr<HandshakingState> handshaking_state;
+  {
+    MutexLock lock(&mu_);
+    shutdown_ = true;
+    // Reset handshaking_state_ since we have been orphaned by the listener
+    // signaling that the listener has stopped serving.
+    handshaking_state = std::move(handshaking_state_);
+  }
+  Unref();
+}
+
+void Chttp2ServerListener::ActiveConnection::SendGoAway() {
+  grpc_chttp2_transport* transport = nullptr;
+  {
+    MutexLock lock(&mu_);
+    transport = transport_;
+  }
+  if (transport != nullptr) {
+    grpc_transport_op* op = grpc_make_transport_op(nullptr);
+    op->goaway_error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+        "Server is stopping to serve requests.");
+    grpc_transport_perform_op(&transport->base, op);
+  }
+}
+
+void Chttp2ServerListener::ActiveConnection::Start(
+    RefCountedPtr<Chttp2ServerListener> listener, grpc_endpoint* endpoint,
+    grpc_channel_args* args) {
+  RefCountedPtr<HandshakingState> handshaking_state_ref;
+  listener_ = std::move(listener);
+  {
+    MutexLock lock(&mu_);
+    if (shutdown_) return;
+    // Hold a ref to HandshakingState to allow starting the handshake outside
+    // the critical region.
+    handshaking_state_ref = handshaking_state_->Ref();
+  }
+  handshaking_state_ref->Start(endpoint, args);
+}
+
+void Chttp2ServerListener::ActiveConnection::OnClose(
+    void* arg, grpc_error_handle /* error */) {
+  ActiveConnection* self = static_cast<ActiveConnection*>(arg);
+  OrphanablePtr<ActiveConnection> connection;
+  {
+    MutexLock listener_lock(&self->listener_->mu_);
+    MutexLock connection_lock(&self->mu_);
+    // The node was already deleted from the connections_ list if the connection
+    // is shutdown.
+    if (!self->shutdown_) {
+      auto it = self->listener_->connections_.find(self);
+      if (it != self->listener_->connections_.end()) {
+        connection = std::move(it->second);
+        self->listener_->connections_.erase(it);
+      }
+    }
+  }
+  self->Unref();
+}
+
+//
+// Chttp2ServerListener
+//
+
+grpc_error_handle Chttp2ServerListener::Create(
+    Server* server, grpc_resolved_address* addr, grpc_channel_args* args,
+    Chttp2ServerArgsModifier args_modifier, int* port_num) {
+  Chttp2ServerListener* listener = nullptr;
+  // The bulk of this method is inside of a lambda to make cleanup
+  // easier without using goto.
+  grpc_error_handle error = [&]() {
+    // Create Chttp2ServerListener.
+    listener = new Chttp2ServerListener(
+        server, args, args_modifier,
+        grpc_resource_quota_from_channel_args(args, true));
+    grpc_resource_quota_ref_internal(listener->resource_quota_);
+    error = grpc_tcp_server_create(
+        &listener->tcp_server_shutdown_complete_, args,
+        grpc_slice_allocator_factory_create(listener->resource_quota_),
+        &listener->tcp_server_);
+    if (error != GRPC_ERROR_NONE) return error;
+    if (server->config_fetcher() != nullptr) {
+      listener->resolved_address_ = *addr;
+      // TODO(yashykt): Consider binding so as to be able to return the port
+      // number.
     } else {
-      if (resource_user != nullptr) {
-        grpc_resource_user_free(resource_user,
-                                GRPC_RESOURCE_QUOTA_CHANNEL_SIZE);
+      error = grpc_tcp_server_add_port(listener->tcp_server_, addr, port_num);
+      if (error != GRPC_ERROR_NONE) return error;
+    }
+    // Create channelz node.
+    if (grpc_channel_args_find_bool(args, GRPC_ARG_ENABLE_CHANNELZ,
+                                    GRPC_ENABLE_CHANNELZ_DEFAULT)) {
+      std::string string_address = grpc_sockaddr_to_uri(addr);
+      listener->channelz_listen_socket_ =
+          MakeRefCounted<channelz::ListenSocketNode>(
+              string_address.c_str(),
+              absl::StrFormat("chttp2 listener %s", string_address.c_str()));
+    }
+    // Register with the server only upon success
+    server->AddListener(OrphanablePtr<Server::ListenerInterface>(listener));
+    return GRPC_ERROR_NONE;
+  }();
+  if (error != GRPC_ERROR_NONE) {
+    if (listener != nullptr) {
+      if (listener->tcp_server_ != nullptr) {
+        // listener is deleted when tcp_server_ is shutdown.
+        grpc_tcp_server_unref(listener->tcp_server_);
+      } else {
+        delete listener;
       }
+    } else {
+      grpc_channel_args_destroy(args);
     }
   }
-  connection_state->handshake_mgr->RemoveFromPendingMgrList(
-      &connection_state->svr_state->pending_handshake_mgrs);
-  gpr_mu_unlock(&connection_state->svr_state->mu);
-  connection_state->handshake_mgr.reset();
-  gpr_free(connection_state->acceptor);
-  grpc_tcp_server_unref(connection_state->svr_state->tcp_server);
-  server_connection_state_unref(connection_state);
+  return error;
 }
 
-static void on_accept(void* arg, grpc_endpoint* tcp,
-                      grpc_pollset* accepting_pollset,
-                      grpc_tcp_server_acceptor* acceptor) {
-  server_state* state = static_cast<server_state*>(arg);
-  gpr_mu_lock(&state->mu);
-  if (state->shutdown) {
-    gpr_mu_unlock(&state->mu);
-    grpc_endpoint_shutdown(tcp, GRPC_ERROR_NONE);
-    grpc_endpoint_destroy(tcp);
-    gpr_free(acceptor);
-    return;
-  }
-  grpc_resource_user* resource_user =
-      grpc_server_get_default_resource_user(state->server);
-  if (resource_user != nullptr &&
-      !grpc_resource_user_safe_alloc(resource_user,
-                                     GRPC_RESOURCE_QUOTA_CHANNEL_SIZE)) {
-    gpr_log(
-        GPR_ERROR,
-        "Memory quota exhausted, rejecting the connection, no handshaking.");
-    gpr_mu_unlock(&state->mu);
-    grpc_endpoint_shutdown(tcp, GRPC_ERROR_NONE);
-    grpc_endpoint_destroy(tcp);
-    gpr_free(acceptor);
-    return;
-  }
-  auto handshake_mgr = grpc_core::MakeRefCounted<grpc_core::HandshakeManager>();
-  handshake_mgr->AddToPendingMgrList(&state->pending_handshake_mgrs);
-  grpc_tcp_server_ref(state->tcp_server);
-  gpr_mu_unlock(&state->mu);
-  server_connection_state* connection_state =
-      static_cast<server_connection_state*>(
-          gpr_zalloc(sizeof(*connection_state)));
-  gpr_ref_init(&connection_state->refs, 1);
-  connection_state->svr_state = state;
-  connection_state->accepting_pollset = accepting_pollset;
-  connection_state->acceptor = acceptor;
-  connection_state->handshake_mgr = handshake_mgr;
-  connection_state->interested_parties = grpc_pollset_set_create();
-  grpc_pollset_set_add_pollset(connection_state->interested_parties,
-                               connection_state->accepting_pollset);
-  grpc_core::HandshakerRegistry::AddHandshakers(
-      grpc_core::HANDSHAKER_SERVER, state->args,
-      connection_state->interested_parties,
-      connection_state->handshake_mgr.get());
-  const grpc_arg* timeout_arg =
-      grpc_channel_args_find(state->args, GRPC_ARG_SERVER_HANDSHAKE_TIMEOUT_MS);
-  connection_state->deadline =
-      grpc_core::ExecCtx::Get()->Now() +
-      grpc_channel_arg_get_integer(timeout_arg,
-                                   {120 * GPR_MS_PER_SEC, 1, INT_MAX});
-  connection_state->handshake_mgr->DoHandshake(
-      tcp, state->args, connection_state->deadline, acceptor, on_handshake_done,
-      connection_state);
+grpc_error_handle Chttp2ServerListener::CreateWithAcceptor(
+    Server* server, const char* name, grpc_channel_args* args,
+    Chttp2ServerArgsModifier args_modifier) {
+  Chttp2ServerListener* listener = new Chttp2ServerListener(
+      server, args, args_modifier,
+      grpc_resource_quota_from_channel_args(args, true));
+  grpc_resource_quota_ref_internal(listener->resource_quota_);
+  grpc_error_handle error = grpc_tcp_server_create(
+      &listener->tcp_server_shutdown_complete_, args,
+      grpc_slice_allocator_factory_create(listener->resource_quota_),
+      &listener->tcp_server_);
+  if (error != GRPC_ERROR_NONE) {
+    delete listener;
+    return error;
+  }
+  // TODO(yangg) channelz
+  TcpServerFdHandler** arg_val =
+      grpc_channel_args_find_pointer<TcpServerFdHandler*>(args, name);
+  *arg_val = grpc_tcp_server_create_fd_handler(listener->tcp_server_);
+  server->AddListener(OrphanablePtr<Server::ListenerInterface>(listener));
+  return GRPC_ERROR_NONE;
 }
 
-/* Server callback: start listening on our ports */
-static void server_start_listener(grpc_server* server, void* arg,
-                                  grpc_pollset** pollsets,
-                                  size_t pollset_count) {
-  server_state* state = static_cast<server_state*>(arg);
-  gpr_mu_lock(&state->mu);
-  state->shutdown = false;
-  gpr_mu_unlock(&state->mu);
-  grpc_tcp_server_start(state->tcp_server, pollsets, pollset_count, on_accept,
-                        state);
+Chttp2ServerListener::Chttp2ServerListener(
+    Server* server, grpc_channel_args* args,
+    Chttp2ServerArgsModifier args_modifier, grpc_resource_quota* resource_quota)
+    : server_(server),
+      args_modifier_(args_modifier),
+      args_(args),
+      resource_quota_(resource_quota) {
+  GRPC_CLOSURE_INIT(&tcp_server_shutdown_complete_, TcpServerShutdownComplete,
+                    this, grpc_schedule_on_exec_ctx);
 }
 
-static void tcp_server_shutdown_complete(void* arg, grpc_error* error) {
-  server_state* state = static_cast<server_state*>(arg);
-  /* ensure all threads have unlocked */
-  gpr_mu_lock(&state->mu);
-  grpc_closure* destroy_done = state->server_destroy_listener_done;
-  GPR_ASSERT(state->shutdown);
-  if (state->pending_handshake_mgrs != nullptr) {
-    state->pending_handshake_mgrs->ShutdownAllPending(GRPC_ERROR_REF(error));
-  }
-  state->channelz_listen_socket.reset();
-  gpr_mu_unlock(&state->mu);
+Chttp2ServerListener::~Chttp2ServerListener() {
   // Flush queued work before destroying handshaker factory, since that
   // may do a synchronous unref.
-  grpc_core::ExecCtx::Get()->Flush();
-  if (destroy_done != nullptr) {
-    destroy_done->cb(destroy_done->cb_arg, GRPC_ERROR_REF(error));
-    grpc_core::ExecCtx::Get()->Flush();
-  }
-  grpc_channel_args_destroy(state->args);
-  gpr_mu_destroy(&state->mu);
-  gpr_free(state);
-}
-
-/* Server callback: destroy the tcp listener (so we don't generate further
-   callbacks) */
-static void server_destroy_listener(grpc_server* server, void* arg,
-                                    grpc_closure* destroy_done) {
-  server_state* state = static_cast<server_state*>(arg);
-  gpr_mu_lock(&state->mu);
-  state->shutdown = true;
-  state->server_destroy_listener_done = destroy_done;
-  grpc_tcp_server* tcp_server = state->tcp_server;
-  gpr_mu_unlock(&state->mu);
-  grpc_tcp_server_shutdown_listeners(tcp_server);
-  grpc_tcp_server_unref(tcp_server);
+  ExecCtx::Get()->Flush();
+  if (on_destroy_done_ != nullptr) {
+    ExecCtx::Run(DEBUG_LOCATION, on_destroy_done_, GRPC_ERROR_NONE);
+    ExecCtx::Get()->Flush();
+  }
+  grpc_resource_quota_unref_internal(resource_quota_);
+  grpc_channel_args_destroy(args_);
 }
 
-static grpc_error* chttp2_server_add_acceptor(grpc_server* server,
-                                              const char* name,
-                                              grpc_channel_args* args) {
-  grpc_tcp_server* tcp_server = nullptr;
-  grpc_error* err = GRPC_ERROR_NONE;
-  server_state* state = nullptr;
-  const grpc_arg* arg = nullptr;
-  grpc_core::TcpServerFdHandler** arg_val = nullptr;
-  state = static_cast<server_state*>(gpr_zalloc(sizeof(*state)));
-  GRPC_CLOSURE_INIT(&state->tcp_server_shutdown_complete,
-                    tcp_server_shutdown_complete, state,
-                    grpc_schedule_on_exec_ctx);
-  err = grpc_tcp_server_create(&state->tcp_server_shutdown_complete, args,
-                               &tcp_server);
-  if (err != GRPC_ERROR_NONE) {
-    goto error;
-  }
-  state->server = server;
-  state->tcp_server = tcp_server;
-  state->args = args;
-  state->shutdown = true;
-  gpr_mu_init(&state->mu);
-  // TODO(yangg) channelz
-  arg = grpc_channel_args_find(args, name);
-  GPR_ASSERT(arg->type == GRPC_ARG_POINTER);
-  arg_val = static_cast<grpc_core::TcpServerFdHandler**>(arg->value.pointer.p);
-  *arg_val = grpc_tcp_server_create_fd_handler(tcp_server);
-
-  grpc_server_add_listener(server, state, server_start_listener,
-                           server_destroy_listener, /* node */ nullptr);
-  return err;
-
-/* Error path: cleanup and return */
-error:
-  GPR_ASSERT(err != GRPC_ERROR_NONE);
-  if (tcp_server) {
-    grpc_tcp_server_unref(tcp_server);
+/* Server callback: start listening on our ports */
+void Chttp2ServerListener::Start(
+    Server* /*server*/, const std::vector<grpc_pollset*>* /* pollsets */) {
+  if (server_->config_fetcher() != nullptr) {
+    grpc_channel_args* args = nullptr;
+    auto watcher = absl::make_unique<ConfigFetcherWatcher>(Ref());
+    config_fetcher_watcher_ = watcher.get();
+    {
+      MutexLock lock(&channel_args_mu_);
+      args = grpc_channel_args_copy(args_);
+    }
+    server_->config_fetcher()->StartWatch(
+        grpc_sockaddr_to_string(&resolved_address_, false), args,
+        std::move(watcher));
   } else {
-    grpc_channel_args_destroy(args);
-    gpr_free(state);
+    {
+      MutexLock lock(&mu_);
+      started_ = true;
+      is_serving_ = true;
+    }
+    StartListening();
   }
-  return err;
 }
 
-grpc_error* grpc_chttp2_server_add_port(grpc_server* server, const char* addr,
-                                        grpc_channel_args* args,
-                                        int* port_num) {
-  grpc_resolved_addresses* resolved = nullptr;
-  grpc_tcp_server* tcp_server = nullptr;
-  size_t i;
-  size_t count = 0;
-  int port_temp;
-  grpc_error* err = GRPC_ERROR_NONE;
-  server_state* state = nullptr;
-  grpc_error** errors = nullptr;
-  size_t naddrs = 0;
-  const grpc_arg* arg = nullptr;
+void Chttp2ServerListener::StartListening() {
+  grpc_tcp_server_start(tcp_server_, &server_->pollsets(), OnAccept, this);
+}
 
-  *port_num = -1;
+void Chttp2ServerListener::SetOnDestroyDone(grpc_closure* on_destroy_done) {
+  MutexLock lock(&mu_);
+  on_destroy_done_ = on_destroy_done;
+}
 
-  if (strncmp(addr, "external:", 9) == 0) {
-    return chttp2_server_add_acceptor(server, addr, args);
+void Chttp2ServerListener::OnAccept(void* arg, grpc_endpoint* tcp,
+                                    grpc_pollset* accepting_pollset,
+                                    grpc_tcp_server_acceptor* acceptor) {
+  Chttp2ServerListener* self = static_cast<Chttp2ServerListener*>(arg);
+  grpc_channel_args* args = nullptr;
+  RefCountedPtr<grpc_server_config_fetcher::ConnectionManager>
+      connection_manager;
+  {
+    MutexLock lock(&self->channel_args_mu_);
+    args = grpc_channel_args_copy(self->args_);
+    connection_manager = self->connection_manager_;
   }
-
-  /* resolve address */
-  err = grpc_blocking_resolve_address(addr, "https", &resolved);
-  if (err != GRPC_ERROR_NONE) {
-    goto error;
+  auto endpoint_cleanup = [&](grpc_error_handle error) {
+    grpc_endpoint_shutdown(tcp, error);
+    grpc_endpoint_destroy(tcp);
+    gpr_free(acceptor);
+  };
+  if (self->server_->config_fetcher() != nullptr) {
+    if (connection_manager == nullptr) {
+      grpc_error_handle error = GRPC_ERROR_CREATE_FROM_STATIC_STRING(
+          "No ConnectionManager configured. Closing connection.");
+      endpoint_cleanup(error);
+      grpc_channel_args_destroy(args);
+      return;
+    }
+    // TODO(yashykt): Maybe combine the following two arg modifiers into a
+    // single one.
+    absl::StatusOr<grpc_channel_args*> args_result =
+        connection_manager->UpdateChannelArgsForConnection(args, tcp);
+    if (!args_result.ok()) {
+      gpr_log(GPR_DEBUG, "Closing connection: %s",
+              args_result.status().ToString().c_str());
+      endpoint_cleanup(
+          GRPC_ERROR_CREATE_FROM_CPP_STRING(args_result.status().ToString()));
+      return;
+    }
+    grpc_error_handle error = GRPC_ERROR_NONE;
+    args = self->args_modifier_(*args_result, &error);
+    if (error != GRPC_ERROR_NONE) {
+      gpr_log(GPR_DEBUG, "Closing connection: %s",
+              grpc_error_std_string(error).c_str());
+      endpoint_cleanup(error);
+      grpc_channel_args_destroy(args);
+      return;
+    }
   }
-  state = static_cast<server_state*>(gpr_zalloc(sizeof(*state)));
-  GRPC_CLOSURE_INIT(&state->tcp_server_shutdown_complete,
-                    tcp_server_shutdown_complete, state,
-                    grpc_schedule_on_exec_ctx);
-  err = grpc_tcp_server_create(&state->tcp_server_shutdown_complete, args,
-                               &tcp_server);
-  if (err != GRPC_ERROR_NONE) {
-    goto error;
-  }
-
-  state->server = server;
-  state->tcp_server = tcp_server;
-  state->args = args;
-  state->shutdown = true;
-  gpr_mu_init(&state->mu);
-
-  naddrs = resolved->naddrs;
-  errors = static_cast<grpc_error**>(gpr_malloc(sizeof(*errors) * naddrs));
-  for (i = 0; i < naddrs; i++) {
-    errors[i] =
-        grpc_tcp_server_add_port(tcp_server, &resolved->addrs[i], &port_temp);
-    if (errors[i] == GRPC_ERROR_NONE) {
-      if (*port_num == -1) {
-        *port_num = port_temp;
+  grpc_resource_user* channel_resource_user = grpc_resource_user_create(
+      self->resource_quota_,
+      absl::StrCat(grpc_endpoint_get_peer(tcp), ":server_channel"));
+  auto connection = MakeOrphanable<ActiveConnection>(
+      accepting_pollset, acceptor, args, channel_resource_user);
+  // We no longer own acceptor
+  acceptor = nullptr;
+  // Hold a ref to connection to allow starting handshake outside the
+  // critical region
+  RefCountedPtr<ActiveConnection> connection_ref = connection->Ref();
+  RefCountedPtr<Chttp2ServerListener> listener_ref;
+  {
+    MutexLock lock(&self->mu_);
+    // Shutdown the the connection if listener's stopped serving.
+    if (!self->shutdown_ && self->is_serving_) {
+      if (!grpc_resource_user_safe_alloc(channel_resource_user,
+                                         GRPC_RESOURCE_QUOTA_CHANNEL_SIZE)) {
+        gpr_log(
+            GPR_INFO,
+            "Memory quota exhausted, rejecting connection, no handshaking.");
       } else {
-        GPR_ASSERT(*port_num == port_temp);
+        // This ref needs to be taken in the critical region after having made
+        // sure that the listener has not been Orphaned, so as to avoid
+        // heap-use-after-free issues where `Ref()` is invoked when the ref of
+        // tcp_server_ has already reached 0. (Ref() implementation of
+        // Chttp2ServerListener is grpc_tcp_server_ref().)
+        listener_ref = self->Ref();
+        self->connections_.emplace(connection.get(), std::move(connection));
       }
-      count++;
     }
   }
-  if (count == 0) {
-    char* msg;
-    gpr_asprintf(&msg, "No address added out of total %" PRIuPTR " resolved",
-                 naddrs);
-    err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
-    gpr_free(msg);
-    goto error;
-  } else if (count != naddrs) {
-    char* msg;
-    gpr_asprintf(&msg,
-                 "Only %" PRIuPTR " addresses added out of total %" PRIuPTR
-                 " resolved",
-                 count, naddrs);
-    err = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(msg, errors, naddrs);
-    gpr_free(msg);
-
-    const char* warning_message = grpc_error_string(err);
-    gpr_log(GPR_INFO, "WARNING: %s", warning_message);
-
-    /* we managed to bind some addresses: continue */
-  }
-  grpc_resolved_addresses_destroy(resolved);
-
-  arg = grpc_channel_args_find(args, GRPC_ARG_ENABLE_CHANNELZ);
-  if (grpc_channel_arg_get_bool(arg, GRPC_ENABLE_CHANNELZ_DEFAULT)) {
-    char* socket_name = nullptr;
-    gpr_asprintf(&socket_name, "chttp2 listener %s", addr);
-    state->channelz_listen_socket =
-        grpc_core::MakeRefCounted<grpc_core::channelz::ListenSocketNode>(
-            grpc_core::UniquePtr<char>(gpr_strdup(addr)),
-            grpc_core::UniquePtr<char>(socket_name));
-  }
-
-  /* Register with the server only upon success */
-  grpc_server_add_listener(server, state, server_start_listener,
-                           server_destroy_listener,
-                           state->channelz_listen_socket);
-  goto done;
-
-/* Error path: cleanup and return */
-error:
-  GPR_ASSERT(err != GRPC_ERROR_NONE);
-  if (resolved) {
-    grpc_resolved_addresses_destroy(resolved);
-  }
-  if (tcp_server) {
-    grpc_tcp_server_unref(tcp_server);
+  if (connection != nullptr) {
+    endpoint_cleanup(GRPC_ERROR_NONE);
   } else {
-    grpc_channel_args_destroy(args);
-    gpr_free(state);
+    connection_ref->Start(std::move(listener_ref), tcp, args);
+  }
+  grpc_channel_args_destroy(args);
+}
+
+void Chttp2ServerListener::TcpServerShutdownComplete(void* arg,
+                                                     grpc_error_handle error) {
+  Chttp2ServerListener* self = static_cast<Chttp2ServerListener*>(arg);
+  self->channelz_listen_socket_.reset();
+  GRPC_ERROR_UNREF(error);
+  delete self;
+}
+
+/* Server callback: destroy the tcp listener (so we don't generate further
+   callbacks) */
+void Chttp2ServerListener::Orphan() {
+  // Cancel the watch before shutting down so as to avoid holding a ref to the
+  // listener in the watcher.
+  if (config_fetcher_watcher_ != nullptr) {
+    server_->config_fetcher()->CancelWatch(config_fetcher_watcher_);
   }
-  *port_num = 0;
+  std::map<ActiveConnection*, OrphanablePtr<ActiveConnection>> connections;
+  grpc_tcp_server* tcp_server;
+  {
+    MutexLock lock(&mu_);
+    shutdown_ = true;
+    is_serving_ = false;
+    // Orphan the connections so that they can start cleaning up.
+    connections = std::move(connections_);
+    // If the listener is currently set to be serving but has not been started
+    // yet, it means that `grpc_tcp_server_start` is in progress. Wait for the
+    // operation to finish to avoid causing races.
+    while (is_serving_ && !started_) {
+      started_cv_.Wait(&mu_);
+    }
+    tcp_server = tcp_server_;
+  }
+  grpc_tcp_server_shutdown_listeners(tcp_server);
+  grpc_tcp_server_unref(tcp_server);
+}
 
-done:
-  if (errors != nullptr) {
-    for (i = 0; i < naddrs; i++) {
-      GRPC_ERROR_UNREF(errors[i]);
+}  // namespace
+
+//
+// Chttp2ServerAddPort()
+//
+
+grpc_error_handle Chttp2ServerAddPort(Server* server, const char* addr,
+                                      grpc_channel_args* args,
+                                      Chttp2ServerArgsModifier args_modifier,
+                                      int* port_num) {
+  if (strncmp(addr, "external:", 9) == 0) {
+    return grpc_core::Chttp2ServerListener::CreateWithAcceptor(
+        server, addr, args, args_modifier);
+  }
+  *port_num = -1;
+  grpc_resolved_addresses* resolved = nullptr;
+  std::vector<grpc_error_handle> error_list;
+  // Using lambda to avoid use of goto.
+  grpc_error_handle error = [&]() {
+    if (absl::StartsWith(addr, kUnixUriPrefix)) {
+      error = grpc_resolve_unix_domain_address(
+          addr + sizeof(kUnixUriPrefix) - 1, &resolved);
+    } else if (absl::StartsWith(addr, kUnixAbstractUriPrefix)) {
+      error = grpc_resolve_unix_abstract_domain_address(
+          addr + sizeof(kUnixAbstractUriPrefix) - 1, &resolved);
+    } else {
+      error = grpc_blocking_resolve_address(addr, "https", &resolved);
+    }
+    if (error != GRPC_ERROR_NONE) return error;
+    // Create a listener for each resolved address.
+    for (size_t i = 0; i < resolved->naddrs; i++) {
+      // If address has a wildcard port (0), use the same port as a previous
+      // listener.
+      if (*port_num != -1 && grpc_sockaddr_get_port(&resolved->addrs[i]) == 0) {
+        grpc_sockaddr_set_port(&resolved->addrs[i], *port_num);
+      }
+      int port_temp = -1;
+      error = grpc_core::Chttp2ServerListener::Create(
+          server, &resolved->addrs[i], grpc_channel_args_copy(args),
+          args_modifier, &port_temp);
+      if (error != GRPC_ERROR_NONE) {
+        error_list.push_back(error);
+      } else {
+        if (*port_num == -1) {
+          *port_num = port_temp;
+        } else {
+          GPR_ASSERT(*port_num == port_temp);
+        }
+      }
+    }
+    if (error_list.size() == resolved->naddrs) {
+      std::string msg =
+          absl::StrFormat("No address added out of total %" PRIuPTR " resolved",
+                          resolved->naddrs);
+      return GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(
+          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->naddrs - error_list.size(), resolved->naddrs);
+      error = GRPC_ERROR_CREATE_REFERENCING_FROM_COPIED_STRING(
+          msg.c_str(), error_list.data(), error_list.size());
+      gpr_log(GPR_INFO, "WARNING: %s", grpc_error_std_string(error).c_str());
+      GRPC_ERROR_UNREF(error);
+      // we managed to bind some addresses: continue without error
     }
-    gpr_free(errors);
+    return GRPC_ERROR_NONE;
+  }();  // lambda end
+  for (grpc_error_handle error : error_list) {
+    GRPC_ERROR_UNREF(error);
   }
-  return err;
+  grpc_channel_args_destroy(args);
+  if (resolved != nullptr) {
+    grpc_resolved_addresses_destroy(resolved);
+  }
+  if (error != GRPC_ERROR_NONE) *port_num = 0;
+  return error;
 }
+
+}  // namespace grpc_core