async_tcp_client: remove callbacks if connection was not closed (envoyproxy#35410)

When the ``AsyncTcpClient`` is being destroyed but it
also has an active client connection, there's a crash since during the
instance destruction, the ``ClientConnection`` object would also be
destroyed, causing ``raiseEvent`` to be called back to
``AsyncTcpClient`` while it is being destroyed

Caught with the following stack trace:
```
Caught Segmentation fault, suspect faulting address 0x0
Backtrace (use tools/stack_decode.py to get line numbers):
Envoy version: ee8c765a07037033766ea556c032120b497152b3/1.27.0/Clean/RELEASE/BoringSSL
#0: __restore_rt [0x7d80ab903420]
#1: Envoy::Extensions::AccessLoggers::Fluentd::FluentdAccessLoggerImpl::onEvent() [0x58313528746b]
#2: Envoy::Tcp::AsyncTcpClientImpl::onEvent() [0x5831359da00a]
#3: Envoy::Network::ConnectionImplBase::raiseConnectionEvent() [0x583135f0521d]
envoyproxy#4: Envoy::Network::ConnectionImpl::raiseEvent() [0x583135e9fed9]
envoyproxy#5: Envoy::Network::ConnectionImpl::closeSocket() [0x583135e9f90c]
envoyproxy#6: Envoy::Network::ConnectionImpl::close() [0x583135e9e54c]
envoyproxy#7: Envoy::Network::ConnectionImpl::~ConnectionImpl() [0x583135e9de5c]
envoyproxy#8: Envoy::Network::ClientConnectionImpl::~ClientConnectionImpl() [0x5831355fd25e]
envoyproxy#9: Envoy::Tcp::AsyncTcpClientImpl::~AsyncTcpClientImpl() [0x5831359da247]
envoyproxy#10: Envoy::Extensions::AccessLoggers::Fluentd::FluentdAccessLoggerImpl::~FluentdAccessLoggerImpl() [0x583135289350]
envoyproxy#11: Envoy::Extensions::AccessLoggers::Fluentd::FluentdAccessLog::ThreadLocalLogger::~ThreadLocalLogger() [0x58313528adbf]
envoyproxy#12: Envoy::ThreadLocal::InstanceImpl::shutdownThread() [0x58313560373a]
envoyproxy#13: Envoy::Server::WorkerImpl::threadRoutine() [0x583135630c0a]
envoyproxy#14: Envoy::Thread::ThreadImplPosix::ThreadImplPosix()::{lambda()#1}::__invoke() [0x5831364e88d5]
envoyproxy#15: start_thread [0x7d80ab8f7609]
```
Risk Level: low
Testing: unit tests
Docs Changes: none
Release Notes: none
Platform Specific Features: none

---------

Signed-off-by: Ohad Vano <ohadvano@gmail.com>

Author: ohadvano

source/common/tcp/async_tcp_client_impl.cc

@@ -24,6 +24,14 @@ AsyncTcpClientImpl::AsyncTcpClientImpl(Event::Dispatcher& dispatcher,
       connect_timer_(dispatcher.createTimer([this]() { onConnectTimeout(); })),
       enable_half_close_(enable_half_close) {}
 
+AsyncTcpClientImpl::~AsyncTcpClientImpl() {
+  if (connection_) {
+    connection_->removeConnectionCallbacks(*this);
+  }
+
+  close(Network::ConnectionCloseType::NoFlush);
+}
+
 bool AsyncTcpClientImpl::connect() {
   if (connection_) {
     return false;
@@ -69,7 +77,8 @@ void AsyncTcpClientImpl::onConnectTimeout() {
 }
 
 void AsyncTcpClientImpl::close(Network::ConnectionCloseType type) {
-  if (connection_) {
+  if (connection_ && !closing_) {
+    closing_ = true;
     connection_->close(type);
   }
 }
@@ -127,6 +136,7 @@ void AsyncTcpClientImpl::onEvent(Network::ConnectionEvent event) {
       detected_close_ = connection_->detectedCloseType();
     }
 
+    closing_ = false;
     dispatcher_.deferredDelete(std::move(connection_));
     if (callbacks_) {
       callbacks_->onEvent(event);

source/common/tcp/async_tcp_client_impl.h

@@ -28,6 +28,7 @@ class AsyncTcpClientImpl : public AsyncTcpClient,
   AsyncTcpClientImpl(Event::Dispatcher& dispatcher,
                      Upstream::ThreadLocalCluster& thread_local_cluster,
                      Upstream::LoadBalancerContext* context, bool enable_half_close);
+  ~AsyncTcpClientImpl();
 
   void close(Network::ConnectionCloseType type) override;
 
@@ -106,6 +107,7 @@ class AsyncTcpClientImpl : public AsyncTcpClient,
   Event::TimerPtr connect_timer_;
   AsyncTcpClientCallbacks* callbacks_{};
   Network::DetectedCloseType detected_close_{Network::DetectedCloseType::Normal};
+  bool closing_{false};
   bool connected_{false};
   bool enable_half_close_{false};
 };

test/common/tcp/async_tcp_client_impl_test.cc

@@ -18,6 +18,15 @@ using testing::Return;
 namespace Envoy {
 namespace Tcp {
 
+class CustomMockClientConnection : public Network::MockClientConnection {
+public:
+  ~CustomMockClientConnection() {
+    if (state_ != Connection::State::Closed) {
+      raiseEvent(Network::ConnectionEvent::LocalClose);
+    }
+  };
+};
+
 class AsyncTcpClientImplTest : public Event::TestUsingSimulatedTime, public testing::Test {
 public:
   AsyncTcpClientImplTest() = default;
@@ -32,7 +41,7 @@ class AsyncTcpClientImplTest : public Event::TestUsingSimulatedTime, public test
   }
 
   void expectCreateConnection(bool trigger_connected = true) {
-    connection_ = new NiceMock<Network::MockClientConnection>();
+    connection_ = new NiceMock<CustomMockClientConnection>();
     Upstream::MockHost::MockCreateConnectionData conn_info;
     connection_->streamInfo().setAttemptCount(1);
     conn_info.connection_ = connection_;
@@ -59,7 +68,7 @@ class AsyncTcpClientImplTest : public Event::TestUsingSimulatedTime, public test
   NiceMock<Event::MockTimer>* connect_timer_;
   NiceMock<Event::MockDispatcher> dispatcher_;
   NiceMock<Upstream::MockClusterManager> cluster_manager_;
-  Network::MockClientConnection* connection_{};
+  CustomMockClientConnection* connection_{};
 
   NiceMock<Tcp::AsyncClient::MockAsyncTcpClientCallbacks> callbacks_;
 };

test/integration/filters/test_network_async_tcp_filter.cc

@@ -41,7 +41,8 @@ class TestNetworkAsyncTcpFilter : public Network::ReadFilter {
       const test::integration::filters::TestNetworkAsyncTcpFilterConfig& config,
       Stats::Scope& scope, Upstream::ClusterManager& cluster_manager)
       : stats_(generateStats("test_network_async_tcp_filter", scope)),
-        cluster_name_(config.cluster_name()), cluster_manager_(cluster_manager) {
+        cluster_name_(config.cluster_name()), kill_after_on_data_(config.kill_after_on_data()),
+        cluster_manager_(cluster_manager) {
     const auto thread_local_cluster = cluster_manager_.getThreadLocalCluster(cluster_name_);
     options_ = std::make_shared<Tcp::AsyncTcpClientOptions>(true);
     if (thread_local_cluster != nullptr) {
@@ -60,6 +61,11 @@ class TestNetworkAsyncTcpFilter : public Network::ReadFilter {
                    data.length());
     client_->write(data, end_stream);
 
+    if (kill_after_on_data_) {
+      Tcp::AsyncTcpClient* c1 = client_.release();
+      delete c1;
+    }
+
     return Network::FilterStatus::StopIteration;
   }
 
@@ -166,6 +172,7 @@ class TestNetworkAsyncTcpFilter : public Network::ReadFilter {
   TestNetworkAsyncTcpFilterStats stats_;
   Tcp::AsyncTcpClientPtr client_;
   absl::string_view cluster_name_;
+  bool kill_after_on_data_;
   std::unique_ptr<RequestAsyncCallbacks> request_callbacks_;
   std::unique_ptr<DownstreamCallbacks> downstream_callbacks_;
   Upstream::ClusterManager& cluster_manager_;

test/integration/filters/test_network_async_tcp_filter.proto

@@ -4,4 +4,5 @@ package test.integration.filters;
 
 message TestNetworkAsyncTcpFilterConfig {
   string cluster_name = 1;
+  bool kill_after_on_data = 2;
 }

test/integration/tcp_async_client_integration_test.cc

@@ -1,3 +1,4 @@
+#include "test/integration/filters/test_network_async_tcp_filter.pb.h"
 #include "test/integration/integration.h"
 
 #include "gtest/gtest.h"
@@ -16,15 +17,37 @@ class TcpAsyncClientIntegrationTest : public testing::TestWithParam<Network::Add
         typed_config:
           "@type": type.googleapis.com/test.integration.filters.TestNetworkAsyncTcpFilterConfig
           cluster_name: cluster_0
-    )EOF")) {}
+    )EOF")) {
+    enableHalfClose(true);
+  }
+
+  void init(bool kill_after_on_data = false) {
+    const std::string yaml = fmt::format(R"EOF(
+        cluster_name: cluster_0
+        kill_after_on_data: {}
+    )EOF",
+                                         kill_after_on_data ? "true" : "false");
+
+    config_helper_.addConfigModifier(
+        [&](envoy::config::bootstrap::v3::Bootstrap& bootstrap) -> void {
+          test::integration::filters::TestNetworkAsyncTcpFilterConfig proto_config;
+          TestUtility::loadFromYaml(yaml, proto_config);
+
+          auto* listener = bootstrap.mutable_static_resources()->mutable_listeners(0);
+          auto* filter_chain = listener->mutable_filter_chains(0);
+          auto* filter = filter_chain->mutable_filters(0);
+          filter->mutable_typed_config()->PackFrom(proto_config);
+        });
+
+    BaseIntegrationTest::initialize();
+  }
 };
 
 INSTANTIATE_TEST_SUITE_P(IpVersions, TcpAsyncClientIntegrationTest,
                          testing::ValuesIn(TestEnvironment::getIpVersionsForTest()));
 
 TEST_P(TcpAsyncClientIntegrationTest, SingleRequest) {
-  enableHalfClose(true);
-  initialize();
+  init();
 
   std::string request("request");
   std::string response("response");
@@ -51,8 +74,7 @@ TEST_P(TcpAsyncClientIntegrationTest, SingleRequest) {
 }
 
 TEST_P(TcpAsyncClientIntegrationTest, MultipleRequestFrames) {
-  enableHalfClose(true);
-  initialize();
+  init();
 
   std::string data_frame_1("data_frame_1");
   std::string data_frame_2("data_frame_2");
@@ -85,8 +107,7 @@ TEST_P(TcpAsyncClientIntegrationTest, MultipleRequestFrames) {
 }
 
 TEST_P(TcpAsyncClientIntegrationTest, MultipleResponseFrames) {
-  enableHalfClose(true);
-  initialize();
+  init();
 
   std::string data_frame_1("data_frame_1");
   std::string response_1("response_1");
@@ -116,8 +137,7 @@ TEST_P(TcpAsyncClientIntegrationTest, Reconnect) {
     return;
   }
 
-  enableHalfClose(true);
-  initialize();
+  init();
 
   IntegrationTcpClientPtr tcp_client = makeTcpConnection(lookupPort("listener_0"));
   ASSERT_TRUE(tcp_client->write("hello1", false));
@@ -143,11 +163,24 @@ TEST_P(TcpAsyncClientIntegrationTest, Reconnect) {
   test_server_->waitForGaugeEq("cluster.cluster_0.upstream_cx_active", 0);
 }
 
+TEST_P(TcpAsyncClientIntegrationTest, ClientTearDown) {
+  init(true);
+
+  std::string request("request");
+
+  IntegrationTcpClientPtr tcp_client = makeTcpConnection(lookupPort("listener_0"));
+  ASSERT_TRUE(tcp_client->write(request, true));
+  FakeRawConnectionPtr fake_upstream_connection;
+  ASSERT_TRUE(fake_upstreams_[0]->waitForRawConnection(fake_upstream_connection));
+  ASSERT_TRUE(fake_upstream_connection->waitForData(request.size()));
+
+  tcp_client->close();
+}
+
 #if ENVOY_PLATFORM_ENABLE_SEND_RST
 // Test if RST close can be detected from downstream and upstream is closed by RST.
 TEST_P(TcpAsyncClientIntegrationTest, TestClientCloseRST) {
-  enableHalfClose(true);
-  initialize();
+  init();
 
   std::string request("request");
   std::string response("response");
@@ -178,8 +211,7 @@ TEST_P(TcpAsyncClientIntegrationTest, TestClientCloseRST) {
 
 // Test if RST close can be detected from upstream.
 TEST_P(TcpAsyncClientIntegrationTest, TestUpstreamCloseRST) {
-  enableHalfClose(true);
-  initialize();
+  init();
 
   std::string request("request");
   std::string response("response");
@@ -212,8 +244,7 @@ TEST_P(TcpAsyncClientIntegrationTest, TestUpstreamCloseRST) {
 // the client. The behavior is different for windows, since RST support is literally supported for
 // unix like system, disabled the test for windows.
 TEST_P(TcpAsyncClientIntegrationTest, TestDownstremHalfClosedThenRST) {
-  enableHalfClose(true);
-  initialize();
+  init();
 
   std::string request("request");
   std::string response("response");