Refactors for server-side asynchronous handshakes

net/tools/quic/quic_dispatcher_test.cc

Index: net/tools/quic/quic_dispatcher_test.cc
diff --git a/net/tools/quic/quic_dispatcher_test.cc b/net/tools/quic/quic_dispatcher_test.cc
index 85712d62fac61f49e4a67b411b52457c077bda02..a857e74e66e773ed82f489f45e8f5a8faa373454 100644
--- a/net/tools/quic/quic_dispatcher_test.cc
+++ b/net/tools/quic/quic_dispatcher_test.cc
@@ -18,7 +18,9 @@
 #include "net/quic/core/quic_utils.h"
 #include "net/quic/test_tools/crypto_test_utils.h"
 #include "net/quic/test_tools/quic_buffered_packet_store_peer.h"
+#include "net/quic/test_tools/quic_crypto_server_config_peer.h"
 #include "net/quic/test_tools/quic_test_utils.h"
+#include "net/quic/test_tools/quic_time_wait_list_manager_peer.h"
 #include "net/test/gtest_util.h"
 #include "net/tools/epoll_server/epoll_server.h"
 #include "net/tools/quic/chlo_extractor.h"
@@ -169,12 +171,15 @@ class MockServerConnection : public MockQuicConnection {
 class QuicDispatcherTest : public ::testing::Test {
  public:
   QuicDispatcherTest()
+      : QuicDispatcherTest(CryptoTestUtils::ProofSourceForTesting()) {}
+
+  explicit QuicDispatcherTest(std::unique_ptr<ProofSource> proof_source)
       : helper_(&eps_, QuicAllocator::BUFFER_POOL),
         alarm_factory_(&eps_),
         version_manager_(AllSupportedVersions()),
         crypto_config_(QuicCryptoServerConfig::TESTING,
                        QuicRandom::GetInstance(),
-                       CryptoTestUtils::ProofSourceForTesting()),
+                       std::move(proof_source)),
         dispatcher_(new TestDispatcher(config_,
                                        &crypto_config_,
                                        &version_manager_,
@@ -1218,6 +1223,9 @@ TEST_P(BufferedPacketStoreTest,
     QuicConnectionId conn_id = i;
     if (FLAGS_quic_create_session_after_insertion &&
         conn_id == kNumConnections) {
+      // The last CHLO should trigger ShouldCreateOrBufferPacketForConnection()
+      // since it's the
+      // first packet arrives on that connection.
       EXPECT_CALL(*dispatcher_,
                   ShouldCreateOrBufferPacketForConnection(conn_id));
     }
@@ -1531,6 +1539,576 @@ TEST_P(BufferedPacketStoreTest, ReceiveCHLOForBufferedConnection) {
   EXPECT_TRUE(store->HasChloForConnection(/*connection_id=*/1));
 }
 
+// Implementation of ProofSource which delegates to a ProofSourceForTesting,
+// except that when the async GetProof is called, it captures the call and
+// allows tests to see that a call is pending, which they can then cause to
+// complete at a time of their choosing.
+class FakeProofSource : public ProofSource {
+ public:
+  FakeProofSource() : delegate_(CryptoTestUtils::ProofSourceForTesting()) {}
+
+  // Before this object is "active", all calls to GetProof will be delegated
+  // immediately.  Once "active", the async ones will be intercepted.  This
+  // distinction is necessary to ensure that GetProof can be called without
+  // interference during test case setup.
+  void Activate() { active_ = true; }
+
+  bool GetProof(const IPAddress& server_ip,
+                const string& hostname,
+                const string& server_config,
+                QuicVersion quic_version,
+                StringPiece chlo_hash,
+                scoped_refptr<ProofSource::Chain>* out_chain,
+                string* out_signature,
+                string* out_leaf_cert_sct) override {
+    return delegate_->GetProof(server_ip, hostname, server_config, quic_version,
+                               chlo_hash, out_chain, out_signature,
+                               out_leaf_cert_sct);
+  }
+
+  void GetProof(const IPAddress& server_ip,
+                const string& hostname,
+                const string& server_config,
+                QuicVersion quic_version,
+                StringPiece chlo_hash,
+                std::unique_ptr<ProofSource::Callback> callback) override {
+    if (!active_) {
+      scoped_refptr<Chain> chain;
+      string signature;
+      string leaf_cert_sct;
+      const bool ok =
+          GetProof(server_ip, hostname, server_config, quic_version,
+                   chlo_hash.as_string(), &chain, &signature, &leaf_cert_sct);
+      callback->Run(ok, chain, signature, leaf_cert_sct,
+                    /* details = */ nullptr);
+      return;
+    }
+
+    params_.push_back(Params{server_ip, hostname, server_config, quic_version,
+                             chlo_hash.as_string(), std::move(callback)});
+  }
+
+  int NumPendingCallbacks() const { return params_.size(); }
+
+  void InvokePendingCallback(int n) {
+    CHECK(NumPendingCallbacks() > n);
+
+    const Params& params = params_[n];
+
+    scoped_refptr<ProofSource::Chain> chain;
+    string signature;
+    string leaf_cert_sct;
+    const bool ok = delegate_->GetProof(params.server_ip, params.hostname,
+                                        params.server_config,
+                                        params.quic_version, params.chlo_hash,
+                                        &chain, &signature, &leaf_cert_sct);
+
+    params.callback->Run(ok, chain, signature, leaf_cert_sct,
+                         /* details = */ nullptr);
+    params_.erase(params_.begin() + n);
+  }
+
+ private:
+  std::unique_ptr<ProofSource> delegate_;
+  bool active_ = false;
+
+  struct Params {
+    IPAddress server_ip;
+    string hostname;
+    string server_config;
+    QuicVersion quic_version;
+    string chlo_hash;
+    std::unique_ptr<ProofSource::Callback> callback;
+  };
+
+  std::vector<Params> params_;
+};
+
+// Test which exercises the async GetProof codepaths, especially in the context
+// of stateless rejection.
+class AsyncGetProofTest : public QuicDispatcherTest {
+ public:
+  AsyncGetProofTest()
+      : QuicDispatcherTest(
+            std::unique_ptr<FakeProofSource>(new FakeProofSource())),
+        client_addr_(net::test::Loopback4(), 1234),
+        crypto_config_peer_(&crypto_config_) {
+    FLAGS_enable_async_get_proof = true;
+    FLAGS_quic_buffer_packet_till_chlo = true;
+    FLAGS_enable_quic_stateless_reject_support = true;
+    FLAGS_quic_use_cheap_stateless_rejects = true;
+    FLAGS_quic_create_session_after_insertion = true;
+  }
+
+  void SetUp() override {
+    QuicDispatcherTest::SetUp();
+
+    clock_ = QuicDispatcherPeer::GetHelper(dispatcher_.get())->GetClock();
+    QuicVersion version = AllSupportedVersions().front();
+    chlo_ = CryptoTestUtils::GenerateDefaultInchoateCHLO(clock_, version,
+                                                         &crypto_config_);
+    chlo_.SetVector(net::kCOPT, net::QuicTagVector{net::kSREJ});
+    // Pass an inchoate CHLO.
+    CryptoTestUtils::GenerateFullCHLO(
+        chlo_, &crypto_config_, server_ip_, client_addr_, version, clock_,
+        &proof_, QuicDispatcherPeer::GetCache(dispatcher_.get()), &full_chlo_);
+
+    GetFakeProofSource()->Activate();
+  }
+
+  FakeProofSource* GetFakeProofSource() const {
+    return static_cast<FakeProofSource*>(crypto_config_peer_.GetProofSource());
+  }
+
+  string SerializeFullCHLO() {
+    return full_chlo_.GetSerialized().AsStringPiece().as_string();
+  }
+
+  string SerializeCHLO() {
+    return chlo_.GetSerialized().AsStringPiece().as_string();
+  }
+
+  // Sets up a session, and crypto stream based on the test parameters.
+  QuicServerSessionBase* GetSession(QuicConnectionId connection_id) {
+    auto it = sessions_.find(connection_id);
+    if (it != sessions_.end()) {
+      return it->second.session;
+    }
+
+    TestQuicSpdyServerSession* session;
+    CreateSession(dispatcher_.get(), config_, connection_id, client_addr_,
+                  &mock_helper_, &mock_alarm_factory_, &crypto_config_,
+                  QuicDispatcherPeer::GetCache(dispatcher_.get()), &session);
+
+    std::unique_ptr<MockQuicCryptoServerStream> crypto_stream(
+        new MockQuicCryptoServerStream(
+            crypto_config_, QuicDispatcherPeer::GetCache(dispatcher_.get()),
+            session, session->stream_helper()));
+    session->SetCryptoStream(crypto_stream.get());
+    crypto_stream->SetPeerSupportsStatelessRejects(true);
+    const bool ok =
+        sessions_
+            .insert(std::make_pair(
+                connection_id, SessionInfo{session, std::move(crypto_stream)}))
+            .second;
+    CHECK(ok);
+    return session;
+  }
+
+ protected:
+  const IPEndPoint client_addr_;
+
+ private:
+  QuicCryptoServerConfigPeer crypto_config_peer_;
+  IPAddress server_ip_;
+  QuicCryptoProof proof_;
+  const QuicClock* clock_;
+  CryptoHandshakeMessage chlo_;
+  CryptoHandshakeMessage full_chlo_;
+
+  struct SessionInfo {
+    TestQuicSpdyServerSession* session;
+    std::unique_ptr<MockQuicCryptoServerStream> crypto_stream;
+  };
+  std::map<QuicConnectionId, SessionInfo> sessions_;
+};
+
+// Test a simple situation of connections which the StatelessRejector will
+// accept.
+TEST_F(AsyncGetProofTest, BasicAccept) {
+  QuicConnectionId conn_id = 1;
+
+  testing::MockFunction<void(int check_point)> check;
+  {
+    InSequence s;
+
+    EXPECT_CALL(check, Call(1));
+    EXPECT_CALL(*dispatcher_, ShouldCreateOrBufferPacketForConnection(conn_id));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id, client_addr_))
+        .WillOnce(testing::Return(GetSession(conn_id)));
+    EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(
+                    GetSession(conn_id)->connection()),
+                ProcessUdpPacket(_, _, _))
+        .WillOnce(testing::WithArg<2>(
+            Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                                 base::Unretained(this), conn_id))));
+
+    EXPECT_CALL(check, Call(2));
+    EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(
+                    GetSession(conn_id)->connection()),
+                ProcessUdpPacket(_, _, _))
+        .WillOnce(testing::WithArg<2>(
+            Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                                 base::Unretained(this), conn_id))));
+  }
+
+  // Send a CHLO that the StatelessRejector will accept.
+  ProcessPacket(client_addr_, conn_id, true, false, SerializeFullCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+
+  check.Call(1);
+  // Complete the ProofSource::GetProof call and verify that a session is
+  // created.
+  GetFakeProofSource()->InvokePendingCallback(0);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 0);
+
+  check.Call(2);
+  // Verify that a data packet gets processed immediately.
+  ProcessPacket(client_addr_, conn_id, true, false, "My name is Data");
+}
+
+// Test a simple situation of connections which the StatelessRejector will
+// reject.
+TEST_F(AsyncGetProofTest, BasicReject) {
+  CreateTimeWaitListManager();
+
+  QuicConnectionId conn_id = 1;
+
+  testing::MockFunction<void(int check_point)> check;
+  {
+    InSequence s;
+    EXPECT_CALL(check, Call(1));
+    EXPECT_CALL(*time_wait_list_manager_,
+                AddConnectionIdToTimeWait(conn_id, _, true, _));
+    EXPECT_CALL(*time_wait_list_manager_,
+                ProcessPacket(_, client_addr_, conn_id, _, _));
+
+    EXPECT_CALL(check, Call(2));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id, client_addr_))
+        .Times(0);
+    EXPECT_CALL(*time_wait_list_manager_,
+                ProcessPacket(_, client_addr_, conn_id, _, _));
+  }
+
+  // Send a CHLO that the StatelessRejector will reject.
+  ProcessPacket(client_addr_, conn_id, true, false, SerializeCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+
+  // Complete the ProofSource::GetProof call and verify that the connection and
+  // packet are processed by the time wait list manager.
+  check.Call(1);
+  GetFakeProofSource()->InvokePendingCallback(0);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 0);
+
+  // Verify that a data packet is passed to the time wait list manager.
+  check.Call(2);
+  ProcessPacket(client_addr_, conn_id, true, false, "My name is Data");
+}
+
+// Test a situation with multiple interleaved connections which the
+// StatelessRejector will accept.
+TEST_F(AsyncGetProofTest, MultipleAccept) {
+  QuicConnectionId conn_id_1 = 1;
+  QuicConnectionId conn_id_2 = 2;
+  QuicBufferedPacketStore* store =
+      QuicDispatcherPeer::GetBufferedPackets(dispatcher_.get());
+
+  testing::MockFunction<void(int check_point)> check;
+  {
+    InSequence s;
+    EXPECT_CALL(check, Call(1));
+    EXPECT_CALL(*dispatcher_,
+                ShouldCreateOrBufferPacketForConnection(conn_id_2));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id_2, client_addr_))
+        .WillOnce(testing::Return(GetSession(conn_id_2)));
+    EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(
+                    GetSession(conn_id_2)->connection()),
+                ProcessUdpPacket(_, _, _))
+        .WillOnce(testing::WithArg<2>(
+            Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                                 base::Unretained(this), conn_id_2))));
+
+    EXPECT_CALL(check, Call(2));
+    EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(
+                    GetSession(conn_id_2)->connection()),
+                ProcessUdpPacket(_, _, _))
+        .WillOnce(testing::WithArg<2>(
+            Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                                 base::Unretained(this), conn_id_2))));
+
+    EXPECT_CALL(check, Call(3));
+    EXPECT_CALL(*dispatcher_,
+                ShouldCreateOrBufferPacketForConnection(conn_id_1));
+
+    EXPECT_CALL(check, Call(4));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id_1, client_addr_))
+        .WillOnce(testing::Return(GetSession(conn_id_1)));
+    EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(
+                    GetSession(conn_id_1)->connection()),
+                ProcessUdpPacket(_, _, _))
+        .WillRepeatedly(testing::WithArg<2>(
+            Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                                 base::Unretained(this), conn_id_1))));
+  }
+
+  // Send a CHLO that the StatelessRejector will accept.
+  ProcessPacket(client_addr_, conn_id_1, true, false, SerializeFullCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+
+  // Send another CHLO that the StatelessRejector will accept.
+  ProcessPacket(client_addr_, conn_id_2, true, false, SerializeFullCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 2);
+
+  // Complete the second ProofSource::GetProof call and verify that a session is
+  // created.
+  check.Call(1);
+  GetFakeProofSource()->InvokePendingCallback(1);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+
+  // Verify that a data packet on that connection gets processed immediately.
+  check.Call(2);
+  ProcessPacket(client_addr_, conn_id_2, true, false, "My name is Data");
+
+  // Verify that a data packet on the other connection does not get processed
+  // yet.
+  check.Call(3);
+  ProcessPacket(client_addr_, conn_id_1, true, false, "My name is Data");
+  EXPECT_TRUE(store->HasBufferedPackets(conn_id_1));
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id_2));
+
+  // Complete the first ProofSource::GetProof call and verify that a session is
+  // created and the buffered packet is processed.
+  check.Call(4);
+  GetFakeProofSource()->InvokePendingCallback(0);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 0);
+}
+
+// Test a situation with multiple interleaved connections which the
+// StatelessRejector will reject.
+TEST_F(AsyncGetProofTest, MultipleReject) {
+  CreateTimeWaitListManager();
+
+  QuicConnectionId conn_id_1 = 1;
+  QuicConnectionId conn_id_2 = 2;
+  QuicBufferedPacketStore* store =
+      QuicDispatcherPeer::GetBufferedPackets(dispatcher_.get());
+
+  testing::MockFunction<void(int check_point)> check;
+  {
+    InSequence s;
+
+    EXPECT_CALL(check, Call(1));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id_2, client_addr_))
+        .Times(0);
+    EXPECT_CALL(*time_wait_list_manager_,
+                AddConnectionIdToTimeWait(conn_id_2, _, true, _));
+    EXPECT_CALL(*time_wait_list_manager_,
+                ProcessPacket(_, client_addr_, conn_id_2, _, _));
+
+    EXPECT_CALL(check, Call(2));
+    EXPECT_CALL(*time_wait_list_manager_,
+                ProcessPacket(_, client_addr_, conn_id_2, _, _));
+
+    EXPECT_CALL(check, Call(3));
+    EXPECT_CALL(*dispatcher_,
+                ShouldCreateOrBufferPacketForConnection(conn_id_1));
+
+    EXPECT_CALL(check, Call(4));
+    EXPECT_CALL(*time_wait_list_manager_,
+                AddConnectionIdToTimeWait(conn_id_1, _, true, _));
+    EXPECT_CALL(*time_wait_list_manager_,
+                ProcessPacket(_, client_addr_, conn_id_1, _, _));
+  }
+
+  // Send a CHLO that the StatelessRejector will reject.
+  ProcessPacket(client_addr_, conn_id_1, true, false, SerializeCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+
+  // Send another CHLO that the StatelessRejector will reject.
+  ProcessPacket(client_addr_, conn_id_2, true, false, SerializeCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 2);
+
+  // Complete the second ProofSource::GetProof call and verify that the
+  // connection and packet are processed by the time wait manager.
+  check.Call(1);
+  GetFakeProofSource()->InvokePendingCallback(1);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+
+  // Verify that a data packet on that connection gets processed immediately by
+  // the time wait manager.
+  check.Call(2);
+  ProcessPacket(client_addr_, conn_id_2, true, false, "My name is Data");
+
+  // Verify that a data packet on the first connection gets buffered.
+  check.Call(3);
+  ProcessPacket(client_addr_, conn_id_1, true, false, "My name is Data");
+  EXPECT_TRUE(store->HasBufferedPackets(conn_id_1));
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id_2));
+
+  // Complete the first ProofSource::GetProof call and verify that the CHLO is
+  // processed by the time wait manager and the remaining packets are discarded.
+  check.Call(4);
+  GetFakeProofSource()->InvokePendingCallback(0);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 0);
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id_1));
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id_2));
+}
+
+// Test a situation with multiple identical CHLOs which the StatelessRejector
+// will reject.
+TEST_F(AsyncGetProofTest, MultipleIdenticalReject) {
+  CreateTimeWaitListManager();
+
+  QuicConnectionId conn_id_1 = 1;
+  QuicBufferedPacketStore* store =
+      QuicDispatcherPeer::GetBufferedPackets(dispatcher_.get());
+
+  testing::MockFunction<void(int check_point)> check;
+  {
+    InSequence s;
+    EXPECT_CALL(check, Call(1));
+    EXPECT_CALL(*dispatcher_,
+                ShouldCreateOrBufferPacketForConnection(conn_id_1));
+
+    EXPECT_CALL(check, Call(2));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id_1, client_addr_))
+        .Times(0);
+    EXPECT_CALL(*time_wait_list_manager_,
+                AddConnectionIdToTimeWait(conn_id_1, _, true, _));
+    EXPECT_CALL(*time_wait_list_manager_,
+                ProcessPacket(_, client_addr_, conn_id_1, _, _));
+  }
+
+  // Send a CHLO that the StatelessRejector will reject.
+  ProcessPacket(client_addr_, conn_id_1, true, false, SerializeCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id_1));
+
+  // Send an identical CHLO which should get buffered.
+  check.Call(1);
+  ProcessPacket(client_addr_, conn_id_1, true, false, SerializeCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+  EXPECT_TRUE(store->HasBufferedPackets(conn_id_1));
+
+  // Complete the ProofSource::GetProof call and verify that the CHLO is
+  // rejected and the copy is discarded.
+  check.Call(2);
+  GetFakeProofSource()->InvokePendingCallback(0);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 0);
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id_1));
+}
+
+// Test dispatcher behavior when packets time out of the buffer while CHLO
+// validation is still pending.
+TEST_F(AsyncGetProofTest, BufferTimeout) {
+  CreateTimeWaitListManager();
+
+  QuicConnectionId conn_id = 1;
+  QuicBufferedPacketStore* store =
+      QuicDispatcherPeer::GetBufferedPackets(dispatcher_.get());
+  QuicBufferedPacketStorePeer::set_clock(store, mock_helper_.GetClock());
+
+  testing::MockFunction<void(int check_point)> check;
+  {
+    InSequence s;
+    EXPECT_CALL(check, Call(1));
+    EXPECT_CALL(*dispatcher_, ShouldCreateOrBufferPacketForConnection(conn_id));
+
+    EXPECT_CALL(check, Call(2));
+    EXPECT_CALL(*time_wait_list_manager_,
+                ProcessPacket(_, client_addr_, conn_id, _, _));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id, client_addr_))
+        .Times(0);
+  }
+
+  // Send a CHLO that the StatelessRejector will accept.
+  ProcessPacket(client_addr_, conn_id, true, false, SerializeFullCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id));
+
+  // Send a data packet that will get buffered
+  check.Call(1);
+  ProcessPacket(client_addr_, conn_id, true, false, "My name is Data");
+  EXPECT_TRUE(store->HasBufferedPackets(conn_id));
+
+  // Pretend that enough time has gone by for the packets to get expired out of
+  // the buffer
+  mock_helper_.AdvanceTime(
+      QuicTime::Delta::FromSeconds(kInitialIdleTimeoutSecs));
+  QuicBufferedPacketStorePeer::expiration_alarm(store)->Cancel();
+  store->OnExpirationTimeout();
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id));
+  EXPECT_TRUE(time_wait_list_manager_->IsConnectionIdInTimeWait(conn_id));
+
+  // Now allow the CHLO validation to complete, and verify that no connection
+  // gets created.
+  check.Call(2);
+  GetFakeProofSource()->InvokePendingCallback(0);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 0);
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id));
+  EXPECT_TRUE(time_wait_list_manager_->IsConnectionIdInTimeWait(conn_id));
+}
+
+// Test behavior when packets time out of the buffer *and* the connection times
+// out of the time wait manager while CHLO validation is still pending.  This
+// *should* be impossible, but anything can happen with timing conditions.
+TEST_F(AsyncGetProofTest, TimeWaitTimeout) {
+  QuicConnectionId conn_id = 1;
+  QuicBufferedPacketStore* store =
+      QuicDispatcherPeer::GetBufferedPackets(dispatcher_.get());
+  QuicBufferedPacketStorePeer::set_clock(store, mock_helper_.GetClock());
+  CreateTimeWaitListManager();
+  QuicTimeWaitListManagerPeer::set_clock(time_wait_list_manager_,
+                                         mock_helper_.GetClock());
+
+  testing::MockFunction<void(int check_point)> check;
+  {
+    InSequence s;
+    EXPECT_CALL(check, Call(1));
+    EXPECT_CALL(*dispatcher_, ShouldCreateOrBufferPacketForConnection(conn_id));
+
+    EXPECT_CALL(check, Call(2));
+    EXPECT_CALL(*dispatcher_, ShouldCreateOrBufferPacketForConnection(conn_id));
+    EXPECT_CALL(*dispatcher_, CreateQuicSession(conn_id, client_addr_))
+        .WillOnce(testing::Return(GetSession(conn_id)));
+    EXPECT_CALL(*reinterpret_cast<MockQuicConnection*>(
+                    GetSession(conn_id)->connection()),
+                ProcessUdpPacket(_, _, _))
+        .WillOnce(testing::WithArg<2>(
+            Invoke(CreateFunctor(&QuicDispatcherTest::ValidatePacket,
+                                 base::Unretained(this), conn_id))));
+  }
+
+  // Send a CHLO that the StatelessRejector will accept.
+  ProcessPacket(client_addr_, conn_id, true, false, SerializeFullCHLO());
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 1);
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id));
+
+  // Send a data packet that will get buffered
+  check.Call(1);
+  ProcessPacket(client_addr_, conn_id, true, false, "My name is Data");
+  EXPECT_TRUE(store->HasBufferedPackets(conn_id));
+
+  // Pretend that enough time has gone by for the packets to get expired out of
+  // the buffer
+  mock_helper_.AdvanceTime(
+      QuicTime::Delta::FromSeconds(kInitialIdleTimeoutSecs));
+  QuicBufferedPacketStorePeer::expiration_alarm(store)->Cancel();
+  store->OnExpirationTimeout();
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id));
+  EXPECT_TRUE(time_wait_list_manager_->IsConnectionIdInTimeWait(conn_id));
+
+  // Pretend that enough time has gone by for the connection ID to be removed
+  // from the time wait manager
+  mock_helper_.AdvanceTime(
+      QuicTimeWaitListManagerPeer::time_wait_period(time_wait_list_manager_));
+  QuicTimeWaitListManagerPeer::expiration_alarm(time_wait_list_manager_)
+      ->Cancel();
+  time_wait_list_manager_->CleanUpOldConnectionIds();
+  EXPECT_FALSE(time_wait_list_manager_->IsConnectionIdInTimeWait(conn_id));
+
+  // Now allow the CHLO validation to complete.  Expect that a connection is
+  // indeed created, since QUIC has forgotten that this connection ever existed.
+  // This is a miniscule corner case which should never happen in the wild, so
+  // really we are just verifying that the dispatcher does not explode in this
+  // situation.
+  check.Call(2);
+  GetFakeProofSource()->InvokePendingCallback(0);
+  ASSERT_EQ(GetFakeProofSource()->NumPendingCallbacks(), 0);
+  EXPECT_FALSE(store->HasBufferedPackets(conn_id));
+  EXPECT_FALSE(time_wait_list_manager_->IsConnectionIdInTimeWait(conn_id));
+}
+
 }  // namespace
 }  // namespace test
 }  // namespace net