// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stddef.h>
#include <string>
#include <sys/epoll.h>
#include <vector>

#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/singleton.h"
#include "base/strings/string_number_conversions.h"
#include "base/synchronization/waitable_event.h"
#include "base/time/time.h"
#include "net/base/ip_endpoint.h"
#include "net/quic/congestion_control/tcp_cubic_sender.h"
#include "net/quic/crypto/aes_128_gcm_12_encrypter.h"
#include "net/quic/crypto/null_encrypter.h"
#include "net/quic/quic_flags.h"
#include "net/quic/quic_framer.h"
#include "net/quic/quic_packet_creator.h"
#include "net/quic/quic_protocol.h"
#include "net/quic/quic_server_id.h"
#include "net/quic/quic_utils.h"
#include "net/quic/test_tools/quic_connection_peer.h"
#include "net/quic/test_tools/quic_flow_controller_peer.h"
#include "net/quic/test_tools/quic_sent_packet_manager_peer.h"
#include "net/quic/test_tools/quic_session_peer.h"
#include "net/quic/test_tools/quic_test_utils.h"
#include "net/quic/test_tools/reliable_quic_stream_peer.h"
#include "net/test/gtest_util.h"
#include "net/tools/epoll_server/epoll_server.h"
#include "net/tools/quic/quic_epoll_connection_helper.h"
#include "net/tools/quic/quic_in_memory_cache.h"
#include "net/tools/quic/quic_packet_writer_wrapper.h"
#include "net/tools/quic/quic_server.h"
#include "net/tools/quic/quic_socket_utils.h"
#include "net/tools/quic/quic_spdy_client_stream.h"
#include "net/tools/quic/test_tools/http_message.h"
#include "net/tools/quic/test_tools/packet_dropping_test_writer.h"
#include "net/tools/quic/test_tools/quic_client_peer.h"
#include "net/tools/quic/test_tools/quic_dispatcher_peer.h"
#include "net/tools/quic/test_tools/quic_in_memory_cache_peer.h"
#include "net/tools/quic/test_tools/quic_server_peer.h"
#include "net/tools/quic/test_tools/quic_test_client.h"
#include "net/tools/quic/test_tools/server_thread.h"
#include "testing/gtest/include/gtest/gtest.h"

using base::StringPiece;
using base::WaitableEvent;
using net::EpollServer;
using net::test::GenerateBody;
using net::test::QuicConnectionPeer;
using net::test::QuicFlowControllerPeer;
using net::test::QuicSentPacketManagerPeer;
using net::test::QuicSessionPeer;
using net::test::ReliableQuicStreamPeer;
using net::test::ValueRestore;
using net::test::kClientDataStreamId1;
using net::tools::test::PacketDroppingTestWriter;
using net::tools::test::QuicDispatcherPeer;
using net::tools::test::QuicServerPeer;
using std::ostream;
using std::string;
using std::vector;

namespace net {
namespace tools {
namespace test {
namespace {

const char kFooResponseBody[] = "Artichoke hearts make me happy.";
const char kBarResponseBody[] = "Palm hearts are pretty delicious, also.";

// Run all tests with the cross products of all versions.
struct TestParams {
  TestParams(const QuicVersionVector& client_supported_versions,
             const QuicVersionVector& server_supported_versions,
             QuicVersion negotiated_version,
             bool use_pacing,
             bool use_fec,
             QuicTag congestion_control_tag)
      : client_supported_versions(client_supported_versions),
        server_supported_versions(server_supported_versions),
        negotiated_version(negotiated_version),
        use_pacing(use_pacing),
        use_fec(use_fec),
        congestion_control_tag(congestion_control_tag) {
  }

  friend ostream& operator<<(ostream& os, const TestParams& p) {
    os << "{ server_supported_versions: "
       << QuicVersionVectorToString(p.server_supported_versions);
    os << " client_supported_versions: "
       << QuicVersionVectorToString(p.client_supported_versions);
    os << " negotiated_version: " << QuicVersionToString(p.negotiated_version);
    os << " use_pacing: " << p.use_pacing;
    os << " use_fec: " << p.use_fec;
    os << " congestion_control_tag: "
       << QuicUtils::TagToString(p.congestion_control_tag) << " }";
    return os;
  }

  QuicVersionVector client_supported_versions;
  QuicVersionVector server_supported_versions;
  QuicVersion negotiated_version;
  bool use_pacing;
  bool use_fec;
  QuicTag congestion_control_tag;
};

// Constructs various test permutations.
vector<TestParams> GetTestParams() {
  vector<TestParams> params;
  QuicVersionVector all_supported_versions = QuicSupportedVersions();
  // TODO(rtenneti): Add kTBBR after BBR code is checked in.
  // QuicTag congestion_control_tags[] = {kRENO, kTBBR, kQBIC};
  QuicTag congestion_control_tags[] = {kRENO, kQBIC};
  QuicVersionVector spdy3_versions;
  QuicVersionVector spdy4_versions;
  for (QuicVersion version : all_supported_versions) {
    if (version > QUIC_VERSION_23) {
      spdy4_versions.push_back(version);
    } else {
      spdy3_versions.push_back(version);
    }
  }
  for (size_t congestion_control_index = 0;
       congestion_control_index < arraysize(congestion_control_tags);
       congestion_control_index++) {
    QuicTag congestion_control_tag =
        congestion_control_tags[congestion_control_index];
    for (int use_fec = 0; use_fec < 2; ++use_fec) {
      for (int use_pacing = 0; use_pacing < 2; ++use_pacing) {
        for (int spdy_version = 3; spdy_version <= 4; ++spdy_version) {
          const QuicVersionVector* client_versions =
              spdy_version == 3 ? &spdy3_versions : &spdy4_versions;
          // Add an entry for server and client supporting all versions.
          params.push_back(TestParams(*client_versions, all_supported_versions,
                                      (*client_versions)[0], use_pacing != 0,
                                      use_fec != 0, congestion_control_tag));

          // Test client supporting all versions and server supporting 1
          // version. Simulate an old server and exercise version downgrade in
          // the client. Protocol negotiation should occur. Skip the i = 0 case
          // because it is essentially the same as the default case.
          for (QuicVersion version : *client_versions) {
            QuicVersionVector server_supported_versions;
            server_supported_versions.push_back(version);
            params.push_back(
                TestParams(*client_versions, server_supported_versions,
                           server_supported_versions[0], use_pacing != 0,
                           use_fec != 0, congestion_control_tag));
          }
        }
      }
    }
  }
  return params;
}

class ServerDelegate : public PacketDroppingTestWriter::Delegate {
 public:
  ServerDelegate(TestWriterFactory* writer_factory,
                 QuicDispatcher* dispatcher)
      : writer_factory_(writer_factory),
        dispatcher_(dispatcher) {}
  ~ServerDelegate() override {}
  void OnPacketSent(WriteResult result) override {
    writer_factory_->OnPacketSent(result);
  }
  void OnCanWrite() override { dispatcher_->OnCanWrite(); }

 private:
  TestWriterFactory* writer_factory_;
  QuicDispatcher* dispatcher_;
};

class ClientDelegate : public PacketDroppingTestWriter::Delegate {
 public:
  explicit ClientDelegate(QuicClient* client) : client_(client) {}
  ~ClientDelegate() override {}
  void OnPacketSent(WriteResult result) override {}
  void OnCanWrite() override {
    EpollEvent event(EPOLLOUT, false);
    client_->OnEvent(client_->fd(), &event);
  }

 private:
  QuicClient* client_;
};

class EndToEndTest : public ::testing::TestWithParam<TestParams> {
 protected:
  EndToEndTest()
      : server_hostname_("example.com"),
        server_started_(false),
        strike_register_no_startup_period_(false) {
    net::IPAddressNumber ip;
    CHECK(net::ParseIPLiteralToNumber("127.0.0.1", &ip));
    server_address_ = IPEndPoint(ip, 0);

    client_supported_versions_ = GetParam().client_supported_versions;
    server_supported_versions_ = GetParam().server_supported_versions;
    negotiated_version_ = GetParam().negotiated_version;
    FLAGS_enable_quic_fec = GetParam().use_fec;

    VLOG(1) << "Using Configuration: " << GetParam();

    // Use different flow control windows for client/server.
    client_config_.SetInitialStreamFlowControlWindowToSend(
        2 * kInitialStreamFlowControlWindowForTest);
    client_config_.SetInitialSessionFlowControlWindowToSend(
        2 * kInitialSessionFlowControlWindowForTest);
    server_config_.SetInitialStreamFlowControlWindowToSend(
        3 * kInitialStreamFlowControlWindowForTest);
    server_config_.SetInitialSessionFlowControlWindowToSend(
        3 * kInitialSessionFlowControlWindowForTest);

    QuicInMemoryCachePeer::ResetForTests();
    AddToCache("GET", "https://www.google.com/foo",
               "HTTP/1.1", "200", "OK", kFooResponseBody);
    AddToCache("GET", "https://www.google.com/bar",
               "HTTP/1.1", "200", "OK", kBarResponseBody);
  }

  ~EndToEndTest() override {
    // TODO(rtenneti): port RecycleUnusedPort if needed.
    // RecycleUnusedPort(server_address_.port());
    QuicInMemoryCachePeer::ResetForTests();
  }

  QuicTestClient* CreateQuicClient(QuicPacketWriterWrapper* writer) {
    QuicTestClient* client = new QuicTestClient(
        server_address_,
        server_hostname_,
        false,  // not secure
        client_config_,
        client_supported_versions_);
    client->UseWriter(writer);
    client->Connect();
    return client;
  }

  void set_client_initial_stream_flow_control_receive_window(uint32 window) {
    CHECK(client_.get() == nullptr);
    DVLOG(1) << "Setting client initial stream flow control window: " << window;
    client_config_.SetInitialStreamFlowControlWindowToSend(window);
  }

  void set_client_initial_session_flow_control_receive_window(uint32 window) {
    CHECK(client_.get() == nullptr);
    DVLOG(1) << "Setting client initial session flow control window: "
             << window;
    client_config_.SetInitialSessionFlowControlWindowToSend(window);
  }

  void set_server_initial_stream_flow_control_receive_window(uint32 window) {
    CHECK(server_thread_.get() == nullptr);
    DVLOG(1) << "Setting server initial stream flow control window: "
             << window;
    server_config_.SetInitialStreamFlowControlWindowToSend(window);
  }

  void set_server_initial_session_flow_control_receive_window(uint32 window) {
    CHECK(server_thread_.get() == nullptr);
    DVLOG(1) << "Setting server initial session flow control window: "
             << window;
    server_config_.SetInitialSessionFlowControlWindowToSend(window);
  }

  const QuicSentPacketManager *
  GetSentPacketManagerFromFirstServerSession() const {
    QuicDispatcher* dispatcher =
        QuicServerPeer::GetDispatcher(server_thread_->server());
    QuicSession* session = dispatcher->session_map().begin()->second;
    return &session->connection()->sent_packet_manager();
  }

  bool Initialize() {
    QuicTagVector copt;

    if (GetParam().use_pacing) {
      copt.push_back(kPACE);
    }
    server_config_.SetConnectionOptionsToSend(copt);

    // TODO(nimia): Consider setting the congestion control algorithm for the
    // client as well according to the test parameter.
    copt.push_back(GetParam().congestion_control_tag);

    if (GetParam().use_fec) {
      // Set FEC config in client's connection options and in client session.
      copt.push_back(kFHDR);
    }

    client_config_.SetConnectionOptionsToSend(copt);

    // Start the server first, because CreateQuicClient() attempts
    // to connect to the server.
    StartServer();
    client_.reset(CreateQuicClient(client_writer_));
    if (GetParam().use_fec) {
      // Set FecPolicy to always protect data on all streams.
      client_->SetFecPolicy(FEC_PROTECT_ALWAYS);
    }
    static EpollEvent event(EPOLLOUT, false);
    client_writer_->Initialize(
        reinterpret_cast<QuicEpollConnectionHelper*>(
            QuicConnectionPeer::GetHelper(
                client_->client()->session()->connection())),
        new ClientDelegate(client_->client()));
    return client_->client()->connected();
  }

  void SetUp() override {
    // The ownership of these gets transferred to the QuicPacketWriterWrapper
    // and TestWriterFactory when Initialize() is executed.
    client_writer_ = new PacketDroppingTestWriter();
    server_writer_ = new PacketDroppingTestWriter();
  }

  void TearDown() override { StopServer(); }

  void StartServer() {
    server_thread_.reset(
        new ServerThread(
            new QuicServer(server_config_, server_supported_versions_),
            server_address_,
            strike_register_no_startup_period_));
    server_thread_->Initialize();
    server_address_ = IPEndPoint(server_address_.address(),
                                 server_thread_->GetPort());
    QuicDispatcher* dispatcher =
        QuicServerPeer::GetDispatcher(server_thread_->server());
    TestWriterFactory* packet_writer_factory = new TestWriterFactory();
    QuicDispatcherPeer::SetPacketWriterFactory(dispatcher,
                                               packet_writer_factory);
    QuicDispatcherPeer::UseWriter(dispatcher, server_writer_);
    server_writer_->Initialize(
        QuicDispatcherPeer::GetHelper(dispatcher),
        new ServerDelegate(packet_writer_factory, dispatcher));
    server_thread_->Start();
    server_started_ = true;
  }

  void StopServer() {
    if (!server_started_)
      return;
    if (server_thread_.get()) {
      server_thread_->Quit();
      server_thread_->Join();
    }
  }

  void AddToCache(StringPiece method,
                  StringPiece path,
                  StringPiece version,
                  StringPiece response_code,
                  StringPiece response_detail,
                  StringPiece body) {
    QuicInMemoryCache::GetInstance()->AddSimpleResponse(
        method, path, version, response_code, response_detail, body);
  }

  void SetPacketLossPercentage(int32 loss) {
    // TODO(rtenneti): enable when we can do random packet loss tests in
    // chrome's tree.
    if (loss != 0 && loss != 100)
      return;
    client_writer_->set_fake_packet_loss_percentage(loss);
    server_writer_->set_fake_packet_loss_percentage(loss);
  }

  void SetPacketSendDelay(QuicTime::Delta delay) {
    // TODO(rtenneti): enable when we can do random packet send delay tests in
    // chrome's tree.
    // client_writer_->set_fake_packet_delay(delay);
    // server_writer_->set_fake_packet_delay(delay);
  }

  void SetReorderPercentage(int32 reorder) {
    // TODO(rtenneti): enable when we can do random packet reorder tests in
    // chrome's tree.
    // client_writer_->set_fake_reorder_percentage(reorder);
    // server_writer_->set_fake_reorder_percentage(reorder);
  }

  // Verifies that the client and server connections were both free of packets
  // being discarded, based on connection stats.
  // Calls server_thread_ Pause() and Resume(), which may only be called once
  // per test.
  void VerifyCleanConnection(bool had_packet_loss) {
    QuicConnectionStats client_stats =
        client_->client()->session()->connection()->GetStats();
    if (!had_packet_loss) {
      EXPECT_EQ(0u, client_stats.packets_lost);
    }
    EXPECT_EQ(0u, client_stats.packets_discarded);
    EXPECT_EQ(0u, client_stats.packets_dropped);
    EXPECT_EQ(client_stats.packets_received, client_stats.packets_processed);

    server_thread_->Pause();
    QuicDispatcher* dispatcher =
        QuicServerPeer::GetDispatcher(server_thread_->server());
    ASSERT_EQ(1u, dispatcher->session_map().size());
    QuicSession* session = dispatcher->session_map().begin()->second;
    QuicConnectionStats server_stats = session->connection()->GetStats();
    if (!had_packet_loss) {
      EXPECT_EQ(0u, server_stats.packets_lost);
    }
    EXPECT_EQ(0u, server_stats.packets_discarded);
    // TODO(ianswett): Restore the check for packets_dropped equals 0.
    // The expect for packets received is equal to packets processed fails
    // due to version negotiation packets.
    server_thread_->Resume();
  }

  IPEndPoint server_address_;
  string server_hostname_;
  scoped_ptr<ServerThread> server_thread_;
  scoped_ptr<QuicTestClient> client_;
  PacketDroppingTestWriter* client_writer_;
  PacketDroppingTestWriter* server_writer_;
  bool server_started_;
  QuicConfig client_config_;
  QuicConfig server_config_;
  QuicVersionVector client_supported_versions_;
  QuicVersionVector server_supported_versions_;
  QuicVersion negotiated_version_;
  bool strike_register_no_startup_period_;
};

// Run all end to end tests with all supported versions.
INSTANTIATE_TEST_CASE_P(EndToEndTests,
                        EndToEndTest,
                        ::testing::ValuesIn(GetTestParams()));

TEST_P(EndToEndTest, SimpleRequestResponse) {
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
}

// TODO(rch): figure out how to detect missing v6 supprt (like on the linux
// try bots) and selectively disable this test.
TEST_P(EndToEndTest, DISABLED_SimpleRequestResponsev6) {
  IPAddressNumber ip;
  CHECK(net::ParseIPLiteralToNumber("::1", &ip));
  server_address_ = IPEndPoint(ip, server_address_.port());
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
}

TEST_P(EndToEndTest, SeparateFinPacket) {
  ASSERT_TRUE(Initialize());

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.set_has_complete_message(false);

  // Send a request in two parts: the request and then an empty packet with FIN.
  client_->SendMessage(request);
  client_->SendData("", true);
  client_->WaitForResponse();
  EXPECT_EQ(kFooResponseBody, client_->response_body());
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  // Now do the same thing but with a content length.
  request.AddBody("foo", true);
  client_->SendMessage(request);
  client_->SendData("", true);
  client_->WaitForResponse();
  EXPECT_EQ(kFooResponseBody, client_->response_body());
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
}

TEST_P(EndToEndTest, MultipleRequestResponse) {
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
  EXPECT_EQ(kBarResponseBody, client_->SendSynchronousRequest("/bar"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
}

TEST_P(EndToEndTest, MultipleClients) {
  ASSERT_TRUE(Initialize());
  scoped_ptr<QuicTestClient> client2(CreateQuicClient(nullptr));

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddHeader("content-length", "3");
  request.set_has_complete_message(false);

  client_->SendMessage(request);
  client2->SendMessage(request);

  client_->SendData("bar", true);
  client_->WaitForResponse();
  EXPECT_EQ(kFooResponseBody, client_->response_body());
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  client2->SendData("eep", true);
  client2->WaitForResponse();
  EXPECT_EQ(kFooResponseBody, client2->response_body());
  EXPECT_EQ(200u, client2->response_headers()->parsed_response_code());
}

TEST_P(EndToEndTest, RequestOverMultiplePackets) {
  // Send a large enough request to guarantee fragmentation.
  string huge_request =
      "https://www.google.com/some/path?query=" + string(kMaxPacketSize, '.');
  AddToCache("GET", huge_request, "HTTP/1.1", "200", "OK", kBarResponseBody);

  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kBarResponseBody, client_->SendSynchronousRequest(huge_request));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
}

TEST_P(EndToEndTest, MultiplePacketsRandomOrder) {
  // Send a large enough request to guarantee fragmentation.
  string huge_request =
      "https://www.google.com/some/path?query=" + string(kMaxPacketSize, '.');
  AddToCache("GET", huge_request, "HTTP/1.1", "200", "OK", kBarResponseBody);

  ASSERT_TRUE(Initialize());
  SetPacketSendDelay(QuicTime::Delta::FromMilliseconds(2));
  SetReorderPercentage(50);

  EXPECT_EQ(kBarResponseBody, client_->SendSynchronousRequest(huge_request));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
}

TEST_P(EndToEndTest, PostMissingBytes) {
  ASSERT_TRUE(Initialize());

  // Add a content length header with no body.
  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddHeader("content-length", "3");
  request.set_skip_message_validation(true);

  // This should be detected as stream fin without complete request,
  // triggering an error response.
  client_->SendCustomSynchronousRequest(request);
  EXPECT_EQ("bad", client_->response_body());
  EXPECT_EQ(500u, client_->response_headers()->parsed_response_code());
}

// TODO(rtenneti): DISABLED_LargePostNoPacketLoss seems to be flaky.
// http://crbug.com/297040.
TEST_P(EndToEndTest, DISABLED_LargePostNoPacketLoss) {
  ASSERT_TRUE(Initialize());

  client_->client()->WaitForCryptoHandshakeConfirmed();

  // 1 MB body.
  string body;
  GenerateBody(&body, 1024 * 1024);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);

  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
  VerifyCleanConnection(false);
}

TEST_P(EndToEndTest, LargePostNoPacketLoss1sRTT) {
  ASSERT_TRUE(Initialize());
  SetPacketSendDelay(QuicTime::Delta::FromMilliseconds(1000));

  client_->client()->WaitForCryptoHandshakeConfirmed();

  // 100 KB body.
  string body;
  GenerateBody(&body, 100 * 1024);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);

  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
  VerifyCleanConnection(false);
}

TEST_P(EndToEndTest, LargePostWithPacketLoss) {
  // Connect with lower fake packet loss than we'd like to test.  Until
  // b/10126687 is fixed, losing handshake packets is pretty brutal.
  SetPacketLossPercentage(5);
  ASSERT_TRUE(Initialize());

  // Wait for the server SHLO before upping the packet loss.
  client_->client()->WaitForCryptoHandshakeConfirmed();
  SetPacketLossPercentage(30);

  // 10 KB body.
  string body;
  GenerateBody(&body, 1024 * 10);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);

  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
  VerifyCleanConnection(true);
}

TEST_P(EndToEndTest, LargePostWithPacketLossAndBlockedSocket) {
  // Connect with lower fake packet loss than we'd like to test.  Until
  // b/10126687 is fixed, losing handshake packets is pretty brutal.
  SetPacketLossPercentage(5);
  ASSERT_TRUE(Initialize());

  // Wait for the server SHLO before upping the packet loss.
  client_->client()->WaitForCryptoHandshakeConfirmed();
  SetPacketLossPercentage(10);
  client_writer_->set_fake_blocked_socket_percentage(10);

  // 10 KB body.
  string body;
  GenerateBody(&body, 1024 * 10);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);

  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
}

TEST_P(EndToEndTest, LargePostNoPacketLossWithDelayAndReordering) {
  ASSERT_TRUE(Initialize());

  client_->client()->WaitForCryptoHandshakeConfirmed();
  // Both of these must be called when the writer is not actively used.
  SetPacketSendDelay(QuicTime::Delta::FromMilliseconds(2));
  SetReorderPercentage(30);

  // 1 MB body.
  string body;
  GenerateBody(&body, 1024 * 1024);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);

  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
}

TEST_P(EndToEndTest, LargePostZeroRTTFailure) {
  // Have the server accept 0-RTT without waiting a startup period.
  strike_register_no_startup_period_ = true;

  // Send a request and then disconnect. This prepares the client to attempt
  // a 0-RTT handshake for the next request.
  ASSERT_TRUE(Initialize());

  string body;
  GenerateBody(&body, 20480);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);

  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
  EXPECT_EQ(2, client_->client()->session()->GetNumSentClientHellos());

  client_->Disconnect();

  // The 0-RTT handshake should succeed.
  client_->Connect();
  client_->WaitForResponseForMs(-1);
  ASSERT_TRUE(client_->client()->connected());
  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
  EXPECT_EQ(1, client_->client()->session()->GetNumSentClientHellos());

  client_->Disconnect();

  // Restart the server so that the 0-RTT handshake will take 1 RTT.
  StopServer();
  server_writer_ = new PacketDroppingTestWriter();
  StartServer();

  client_->Connect();
  ASSERT_TRUE(client_->client()->connected());
  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
  EXPECT_EQ(2, client_->client()->session()->GetNumSentClientHellos());
  VerifyCleanConnection(false);
}

TEST_P(EndToEndTest, CorrectlyConfiguredFec) {
  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();
  server_thread_->WaitForCryptoHandshakeConfirmed();

  FecPolicy expected_policy =
      GetParam().use_fec ? FEC_PROTECT_ALWAYS : FEC_PROTECT_OPTIONAL;

  // Verify that server's FEC configuration is correct.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  ASSERT_EQ(1u, dispatcher->session_map().size());
  QuicSession* session = dispatcher->session_map().begin()->second;
  EXPECT_EQ(expected_policy,
            QuicSessionPeer::GetHeadersStream(session)->fec_policy());
  server_thread_->Resume();

  // Verify that client's FEC configuration is correct.
  EXPECT_EQ(expected_policy,
            QuicSessionPeer::GetHeadersStream(
                client_->client()->session())->fec_policy());
  EXPECT_EQ(expected_policy,
            client_->GetOrCreateStream()->fec_policy());
}

// TODO(shess): This is flaky on ChromiumOS bots.
// http://crbug.com/374871
TEST_P(EndToEndTest, DISABLED_LargePostSmallBandwidthLargeBuffer) {
  ASSERT_TRUE(Initialize());
  SetPacketSendDelay(QuicTime::Delta::FromMicroseconds(1));
  // 256KB per second with a 256KB buffer from server to client.  Wireless
  // clients commonly have larger buffers, but our max CWND is 200.
  server_writer_->set_max_bandwidth_and_buffer_size(
      QuicBandwidth::FromBytesPerSecond(256 * 1024), 256 * 1024);

  client_->client()->WaitForCryptoHandshakeConfirmed();

  // 1 MB body.
  string body;
  GenerateBody(&body, 1024 * 1024);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);

  EXPECT_EQ(kFooResponseBody, client_->SendCustomSynchronousRequest(request));
  // This connection will not drop packets, because the buffer size is larger
  // than the default receive window.
  VerifyCleanConnection(false);
}

TEST_P(EndToEndTest, DoNotSetResumeWriteAlarmIfConnectionFlowControlBlocked) {
  // Regression test for b/14677858.
  // Test that the resume write alarm is not set in QuicConnection::OnCanWrite
  // if currently connection level flow control blocked. If set, this results in
  // an infinite loop in the EpollServer, as the alarm fires and is immediately
  // rescheduled.
  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();

  // Ensure both stream and connection level are flow control blocked by setting
  // the send window offset to 0.
  const uint64 kFlowControlWindow =
      server_config_.GetInitialStreamFlowControlWindowToSend();
  QuicSpdyClientStream* stream = client_->GetOrCreateStream();
  QuicSession* session = client_->client()->session();
  QuicFlowControllerPeer::SetSendWindowOffset(stream->flow_controller(), 0);
  QuicFlowControllerPeer::SetSendWindowOffset(session->flow_controller(), 0);
  EXPECT_TRUE(stream->flow_controller()->IsBlocked());
  EXPECT_TRUE(session->flow_controller()->IsBlocked());

  // Make sure that the stream has data pending so that it will be marked as
  // write blocked when it receives a stream level WINDOW_UPDATE.
  stream->SendBody("hello", false);

  // The stream now attempts to write, fails because it is still connection
  // level flow control blocked, and is added to the write blocked list.
  QuicWindowUpdateFrame window_update(stream->id(), 2 * kFlowControlWindow);
  stream->OnWindowUpdateFrame(window_update);

  // Prior to fixing b/14677858 this call would result in an infinite loop in
  // Chromium. As a proxy for detecting this, we now check whether the
  // resume_writes_alarm is set after OnCanWrite. It should not be, as the
  // connection is still flow control blocked.
  session->connection()->OnCanWrite();

  QuicAlarm* resume_writes_alarm =
      QuicConnectionPeer::GetResumeWritesAlarm(session->connection());
  EXPECT_FALSE(resume_writes_alarm->IsSet());
}

TEST_P(EndToEndTest, InvalidStream) {
  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();

  string body;
  GenerateBody(&body, kMaxPacketSize);

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddBody(body, true);
  // Force the client to write with a stream ID belonging to a nonexistent
  // server-side stream.
  QuicSessionPeer::SetNextStreamId(client_->client()->session(), 2);

  client_->SendCustomSynchronousRequest(request);
  // EXPECT_EQ(QUIC_STREAM_CONNECTION_ERROR, client_->stream_error());
  EXPECT_EQ(QUIC_PACKET_FOR_NONEXISTENT_STREAM, client_->connection_error());
}

// TODO(rch): this test seems to cause net_unittests timeouts :|
TEST_P(EndToEndTest, DISABLED_MultipleTermination) {
  ASSERT_TRUE(Initialize());

  HTTPMessage request(HttpConstants::HTTP_1_1,
                      HttpConstants::POST, "/foo");
  request.AddHeader("content-length", "3");
  request.set_has_complete_message(false);

  // Set the offset so we won't frame.  Otherwise when we pick up termination
  // before HTTP framing is complete, we send an error and close the stream,
  // and the second write is picked up as writing on a closed stream.
  QuicSpdyClientStream* stream = client_->GetOrCreateStream();
  ASSERT_TRUE(stream != nullptr);
  ReliableQuicStreamPeer::SetStreamBytesWritten(3, stream);

  client_->SendData("bar", true);
  client_->WaitForWriteToFlush();

  // By default the stream protects itself from writes after terminte is set.
  // Override this to test the server handling buggy clients.
  ReliableQuicStreamPeer::SetWriteSideClosed(
      false, client_->GetOrCreateStream());

  EXPECT_DFATAL(client_->SendData("eep", true), "Fin already buffered");
}

TEST_P(EndToEndTest, Timeout) {
  client_config_.SetIdleConnectionStateLifetime(
      QuicTime::Delta::FromMicroseconds(500),
      QuicTime::Delta::FromMicroseconds(500));
  // Note: we do NOT ASSERT_TRUE: we may time out during initial handshake:
  // that's enough to validate timeout in this case.
  Initialize();
  while (client_->client()->connected()) {
    client_->client()->WaitForEvents();
  }
}

TEST_P(EndToEndTest, NegotiateMaxOpenStreams) {
  // Negotiate 1 max open stream.
  client_config_.SetMaxStreamsPerConnection(1, 1);
  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();

  // Make the client misbehave after negotiation.
  const int kServerMaxStreams = kMaxStreamsMinimumIncrement + 1;
  QuicSessionPeer::SetMaxOpenStreams(client_->client()->session(),
                                     kServerMaxStreams + 1);

  HTTPMessage request(HttpConstants::HTTP_1_1, HttpConstants::POST, "/foo");
  request.AddHeader("content-length", "3");
  request.set_has_complete_message(false);

  // The server supports a small number of additional streams beyond the
  // negotiated limit. Open enough streams to go beyond that limit.
  for (int i = 0; i < kServerMaxStreams + 1; ++i) {
    client_->SendMessage(request);
  }
  client_->WaitForResponse();

  EXPECT_FALSE(client_->connected());
  EXPECT_EQ(QUIC_STREAM_CONNECTION_ERROR, client_->stream_error());
  EXPECT_EQ(QUIC_TOO_MANY_OPEN_STREAMS, client_->connection_error());
}

TEST_P(EndToEndTest, NegotiateCongestionControl) {
  ValueRestore<bool> old_flag(&FLAGS_quic_allow_bbr, true);
  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();

  CongestionControlType expected_congestion_control_type = kReno;
  switch (GetParam().congestion_control_tag) {
    case kRENO:
      expected_congestion_control_type = kReno;
      break;
    case kTBBR:
      expected_congestion_control_type = kBBR;
      break;
    case kQBIC:
      expected_congestion_control_type = kCubic;
      break;
    default:
      DLOG(FATAL) << "Unexpected congestion control tag";
  }

  EXPECT_EQ(expected_congestion_control_type,
            QuicSentPacketManagerPeer::GetSendAlgorithm(
                *GetSentPacketManagerFromFirstServerSession())
            ->GetCongestionControlType());
}

TEST_P(EndToEndTest, LimitMaxOpenStreams) {
  // Server limits the number of max streams to 2.
  server_config_.SetMaxStreamsPerConnection(2, 2);
  // Client tries to negotiate for 10.
  client_config_.SetMaxStreamsPerConnection(10, 5);

  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();
  QuicConfig* client_negotiated_config = client_->client()->session()->config();
  EXPECT_EQ(2u, client_negotiated_config->MaxStreamsPerConnection());
}

TEST_P(EndToEndTest, ClientSuggestsRTT) {
  // Client suggests initial RTT, verify it is used.
  const uint32 kInitialRTT = 20000;
  client_config_.SetInitialRoundTripTimeUsToSend(kInitialRTT);

  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();
  server_thread_->WaitForCryptoHandshakeConfirmed();

  // Pause the server so we can access the server's internals without races.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  ASSERT_EQ(1u, dispatcher->session_map().size());
  const QuicSentPacketManager& client_sent_packet_manager =
      client_->client()->session()->connection()->sent_packet_manager();
  const QuicSentPacketManager& server_sent_packet_manager =
      *GetSentPacketManagerFromFirstServerSession();

  // BBR automatically enables pacing.
  EXPECT_EQ(GetParam().use_pacing ||
            (FLAGS_quic_allow_bbr &&
             GetParam().congestion_control_tag == kTBBR),
            server_sent_packet_manager.using_pacing());
  EXPECT_EQ(GetParam().use_pacing ||
            (FLAGS_quic_allow_bbr &&
             GetParam().congestion_control_tag == kTBBR),
            client_sent_packet_manager.using_pacing());

  EXPECT_EQ(kInitialRTT,
            client_sent_packet_manager.GetRttStats()->initial_rtt_us());
  EXPECT_EQ(kInitialRTT,
            server_sent_packet_manager.GetRttStats()->initial_rtt_us());
  server_thread_->Resume();
}

TEST_P(EndToEndTest, MaxInitialRTT) {
  // Client tries to suggest twice the server's max initial rtt and the server
  // uses the max.
  client_config_.SetInitialRoundTripTimeUsToSend(
      2 * kMaxInitialRoundTripTimeUs);

  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();
  server_thread_->WaitForCryptoHandshakeConfirmed();

  // Pause the server so we can access the server's internals without races.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  ASSERT_EQ(1u, dispatcher->session_map().size());
  QuicSession* session = dispatcher->session_map().begin()->second;
  const QuicSentPacketManager& client_sent_packet_manager =
      client_->client()->session()->connection()->sent_packet_manager();

  // Now that acks have been exchanged, the RTT estimate has decreased on the
  // server and is not infinite on the client.
  EXPECT_FALSE(
      client_sent_packet_manager.GetRttStats()->smoothed_rtt().IsInfinite());
  const RttStats& server_rtt_stats =
      *session->connection()->sent_packet_manager().GetRttStats();
  EXPECT_EQ(static_cast<int64>(kMaxInitialRoundTripTimeUs),
            server_rtt_stats.initial_rtt_us());
  EXPECT_GE(static_cast<int64>(kMaxInitialRoundTripTimeUs),
            server_rtt_stats.smoothed_rtt().ToMicroseconds());
  server_thread_->Resume();
}

TEST_P(EndToEndTest, MinInitialRTT) {
  // Client tries to suggest 0 and the server uses the default.
  client_config_.SetInitialRoundTripTimeUsToSend(0);

  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();
  server_thread_->WaitForCryptoHandshakeConfirmed();

  // Pause the server so we can access the server's internals without races.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  ASSERT_EQ(1u, dispatcher->session_map().size());
  QuicSession* session = dispatcher->session_map().begin()->second;
  const QuicSentPacketManager& client_sent_packet_manager =
      client_->client()->session()->connection()->sent_packet_manager();
  const QuicSentPacketManager& server_sent_packet_manager =
      session->connection()->sent_packet_manager();

  // Now that acks have been exchanged, the RTT estimate has decreased on the
  // server and is not infinite on the client.
  EXPECT_FALSE(
      client_sent_packet_manager.GetRttStats()->smoothed_rtt().IsInfinite());
  // Expect the default rtt of 100ms.
  EXPECT_EQ(static_cast<int64>(100 * kNumMicrosPerMilli),
            server_sent_packet_manager.GetRttStats()->initial_rtt_us());
  // Ensure the bandwidth is valid.
  client_sent_packet_manager.BandwidthEstimate();
  server_sent_packet_manager.BandwidthEstimate();
  server_thread_->Resume();
}

TEST_P(EndToEndTest, 0ByteConnectionId) {
  client_config_.SetBytesForConnectionIdToSend(0);
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  QuicPacketHeader* header = QuicConnectionPeer::GetLastHeader(
      client_->client()->session()->connection());
  EXPECT_EQ(PACKET_0BYTE_CONNECTION_ID,
            header->public_header.connection_id_length);
}

TEST_P(EndToEndTest, 1ByteConnectionId) {
  client_config_.SetBytesForConnectionIdToSend(1);
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
  QuicPacketHeader* header = QuicConnectionPeer::GetLastHeader(
      client_->client()->session()->connection());
  EXPECT_EQ(PACKET_1BYTE_CONNECTION_ID,
            header->public_header.connection_id_length);
}

TEST_P(EndToEndTest, 4ByteConnectionId) {
  client_config_.SetBytesForConnectionIdToSend(4);
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
  QuicPacketHeader* header = QuicConnectionPeer::GetLastHeader(
      client_->client()->session()->connection());
  EXPECT_EQ(PACKET_4BYTE_CONNECTION_ID,
            header->public_header.connection_id_length);
}

TEST_P(EndToEndTest, 8ByteConnectionId) {
  client_config_.SetBytesForConnectionIdToSend(8);
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
  QuicPacketHeader* header = QuicConnectionPeer::GetLastHeader(
      client_->client()->session()->connection());
  EXPECT_EQ(PACKET_8BYTE_CONNECTION_ID,
            header->public_header.connection_id_length);
}

TEST_P(EndToEndTest, 15ByteConnectionId) {
  client_config_.SetBytesForConnectionIdToSend(15);
  ASSERT_TRUE(Initialize());

  // Our server is permissive and allows for out of bounds values.
  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
  QuicPacketHeader* header = QuicConnectionPeer::GetLastHeader(
      client_->client()->session()->connection());
  EXPECT_EQ(PACKET_8BYTE_CONNECTION_ID,
            header->public_header.connection_id_length);
}

TEST_P(EndToEndTest, ResetConnection) {
  ASSERT_TRUE(Initialize());
  client_->client()->WaitForCryptoHandshakeConfirmed();

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
  client_->ResetConnection();
  EXPECT_EQ(kBarResponseBody, client_->SendSynchronousRequest("/bar"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());
}

TEST_P(EndToEndTest, MaxStreamsUberTest) {
  SetPacketLossPercentage(1);
  ASSERT_TRUE(Initialize());
  string large_body;
  GenerateBody(&large_body, 10240);
  int max_streams = 100;

  AddToCache("GET", "/large_response", "HTTP/1.1", "200", "OK", large_body);;

  client_->client()->WaitForCryptoHandshakeConfirmed();
  SetPacketLossPercentage(10);

  for (int i = 0; i < max_streams; ++i) {
    EXPECT_LT(0, client_->SendRequest("/large_response"));
  }

  // WaitForEvents waits 50ms and returns true if there are outstanding
  // requests.
  while (client_->client()->WaitForEvents() == true) {
  }
}

TEST_P(EndToEndTest, StreamCancelErrorTest) {
  ASSERT_TRUE(Initialize());
  string small_body;
  GenerateBody(&small_body, 256);

  AddToCache("GET", "/small_response", "HTTP/1.1", "200", "OK", small_body);

  client_->client()->WaitForCryptoHandshakeConfirmed();

  QuicSession* session = client_->client()->session();
  // Lose the request.
  SetPacketLossPercentage(100);
  EXPECT_LT(0, client_->SendRequest("/small_response"));
  client_->client()->WaitForEvents();
  // Transmit the cancel, and ensure the connection is torn down properly.
  SetPacketLossPercentage(0);
  QuicStreamId stream_id = kClientDataStreamId1;
  session->SendRstStream(stream_id, QUIC_STREAM_CANCELLED, 0);

  // WaitForEvents waits 50ms and returns true if there are outstanding
  // requests.
  while (client_->client()->WaitForEvents() == true) {
  }
  // It should be completely fine to RST a stream before any data has been
  // received for that stream.
  EXPECT_EQ(QUIC_NO_ERROR, client_->connection_error());
}

class WrongAddressWriter : public QuicPacketWriterWrapper {
 public:
  WrongAddressWriter() {
    IPAddressNumber ip;
    CHECK(net::ParseIPLiteralToNumber("127.0.0.2", &ip));
    self_address_ = IPEndPoint(ip, 0);
  }

  WriteResult WritePacket(const char* buffer,
                          size_t buf_len,
                          const IPAddressNumber& real_self_address,
                          const IPEndPoint& peer_address) override {
    // Use wrong address!
    return QuicPacketWriterWrapper::WritePacket(
        buffer, buf_len, self_address_.address(), peer_address);
  }

  bool IsWriteBlockedDataBuffered() const override { return false; }

  IPEndPoint self_address_;
};

TEST_P(EndToEndTest, ConnectionMigrationClientIPChanged) {
  // Tests that the client's IP can not change during an established QUIC
  // connection. If it changes, the connection is closed by the server as we do
  // not yet support IP migration.
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  WrongAddressWriter* writer = new WrongAddressWriter();

  writer->set_writer(new QuicDefaultPacketWriter(client_->client()->fd()));
  QuicConnectionPeer::SetWriter(client_->client()->session()->connection(),
                                writer,
                                /* owns_writer= */ true);

  client_->SendSynchronousRequest("/bar");

  EXPECT_EQ(QUIC_STREAM_CONNECTION_ERROR, client_->stream_error());
  EXPECT_EQ(QUIC_ERROR_MIGRATING_ADDRESS, client_->connection_error());
}

TEST_P(EndToEndTest, ConnectionMigrationClientPortChanged) {
  // Tests that the client's port can change during an established QUIC
  // connection, and that doing so does not result in the connection being
  // closed by the server.
  ASSERT_TRUE(Initialize());

  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  // Store the client address which was used to send the first request.
  IPEndPoint old_address = client_->client()->client_address();

  // Stop listening on the old FD.
  EpollServer* eps = client_->epoll_server();
  int old_fd = client_->client()->fd();
  eps->UnregisterFD(old_fd);
  // Create a new socket before closing the old one, which will result in a new
  // ephemeral port.
  QuicClientPeer::CreateUDPSocket(client_->client());
  close(old_fd);

  // The packet writer needs to be updated to use the new FD.
  client_->client()->CreateQuicPacketWriter();

  // Change the internal state of the client and connection to use the new port,
  // this is done because in a real NAT rebinding the client wouldn't see any
  // port change, and so expects no change to incoming port.
  // This is kind of ugly, but needed as we are simply swapping out the client
  // FD rather than any more complex NAT rebinding simulation.
  int new_port = client_->client()->client_address().port();
  QuicClientPeer::SetClientPort(client_->client(), new_port);
  QuicConnectionPeer::SetSelfAddress(
      client_->client()->session()->connection(),
      IPEndPoint(
          client_->client()->session()->connection()->self_address().address(),
          new_port));

  // Register the new FD for epoll events.
  int new_fd = client_->client()->fd();
  eps->RegisterFD(new_fd, client_->client(), EPOLLIN | EPOLLOUT | EPOLLET);

  // Send a second request, using the new FD.
  EXPECT_EQ(kBarResponseBody, client_->SendSynchronousRequest("/bar"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  // Verify that the client's ephemeral port is different.
  IPEndPoint new_address = client_->client()->client_address();
  EXPECT_EQ(old_address.address(), new_address.address());
  EXPECT_NE(old_address.port(), new_address.port());
}

TEST_P(EndToEndTest, DifferentFlowControlWindows) {
  // Client and server can set different initial flow control receive windows.
  // These are sent in CHLO/SHLO. Tests that these values are exchanged properly
  // in the crypto handshake.
  const uint32 kClientStreamIFCW = 123456;
  const uint32 kClientSessionIFCW = 234567;
  set_client_initial_stream_flow_control_receive_window(kClientStreamIFCW);
  set_client_initial_session_flow_control_receive_window(kClientSessionIFCW);

  const uint32 kServerStreamIFCW = 654321;
  const uint32 kServerSessionIFCW = 765432;
  set_server_initial_stream_flow_control_receive_window(kServerStreamIFCW);
  set_server_initial_session_flow_control_receive_window(kServerSessionIFCW);

  ASSERT_TRUE(Initialize());

  // Values are exchanged during crypto handshake, so wait for that to finish.
  client_->client()->WaitForCryptoHandshakeConfirmed();
  server_thread_->WaitForCryptoHandshakeConfirmed();

  // Open a data stream to make sure the stream level flow control is updated.
  QuicSpdyClientStream* stream = client_->GetOrCreateStream();
  stream->SendBody("hello", false);

  // Client should have the right values for server's receive window.
  EXPECT_EQ(kServerStreamIFCW,
            client_->client()
                ->session()
                ->config()
                ->ReceivedInitialStreamFlowControlWindowBytes());
  EXPECT_EQ(kServerSessionIFCW,
            client_->client()
                ->session()
                ->config()
                ->ReceivedInitialSessionFlowControlWindowBytes());
  EXPECT_EQ(kServerStreamIFCW, QuicFlowControllerPeer::SendWindowOffset(
                                   stream->flow_controller()));
  EXPECT_EQ(kServerSessionIFCW,
            QuicFlowControllerPeer::SendWindowOffset(
                client_->client()->session()->flow_controller()));

  // Server should have the right values for client's receive window.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  QuicSession* session = dispatcher->session_map().begin()->second;
  EXPECT_EQ(kClientStreamIFCW,
            session->config()->ReceivedInitialStreamFlowControlWindowBytes());
  EXPECT_EQ(kClientSessionIFCW,
            session->config()->ReceivedInitialSessionFlowControlWindowBytes());
  EXPECT_EQ(kClientSessionIFCW, QuicFlowControllerPeer::SendWindowOffset(
                                    session->flow_controller()));
  server_thread_->Resume();
}

TEST_P(EndToEndTest, HeadersAndCryptoStreamsNoConnectionFlowControl) {
  // The special headers and crypto streams should be subject to per-stream flow
  // control limits, but should not be subject to connection level flow control.
  const uint32 kStreamIFCW = 123456;
  const uint32 kSessionIFCW = 234567;
  set_client_initial_stream_flow_control_receive_window(kStreamIFCW);
  set_client_initial_session_flow_control_receive_window(kSessionIFCW);
  set_server_initial_stream_flow_control_receive_window(kStreamIFCW);
  set_server_initial_session_flow_control_receive_window(kSessionIFCW);

  ASSERT_TRUE(Initialize());

  // Wait for crypto handshake to finish. This should have contributed to the
  // crypto stream flow control window, but not affected the session flow
  // control window.
  client_->client()->WaitForCryptoHandshakeConfirmed();
  server_thread_->WaitForCryptoHandshakeConfirmed();

  QuicCryptoStream* crypto_stream =
      QuicSessionPeer::GetCryptoStream(client_->client()->session());
  EXPECT_LT(
      QuicFlowControllerPeer::SendWindowSize(crypto_stream->flow_controller()),
      kStreamIFCW);
  EXPECT_EQ(kSessionIFCW, QuicFlowControllerPeer::SendWindowSize(
                              client_->client()->session()->flow_controller()));

  // Send a request with no body, and verify that the connection level window
  // has not been affected.
  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));

  QuicHeadersStream* headers_stream =
      QuicSessionPeer::GetHeadersStream(client_->client()->session());
  EXPECT_LT(
      QuicFlowControllerPeer::SendWindowSize(headers_stream->flow_controller()),
      kStreamIFCW);
  EXPECT_EQ(kSessionIFCW, QuicFlowControllerPeer::SendWindowSize(
                              client_->client()->session()->flow_controller()));

  // Server should be in a similar state: connection flow control window should
  // not have any bytes marked as received.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  QuicSession* session = dispatcher->session_map().begin()->second;
  QuicFlowController* server_connection_flow_controller =
      session->flow_controller();
  EXPECT_EQ(kSessionIFCW, QuicFlowControllerPeer::ReceiveWindowSize(
      server_connection_flow_controller));
  server_thread_->Resume();
}

TEST_P(EndToEndTest, RequestWithNoBodyWillNeverSendStreamFrameWithFIN) {
  // Regression test for b/16010251.
  // A stream created on receipt of a simple request with no body will never get
  // a stream frame with a FIN. Verify that we don't keep track of the stream in
  // the locally closed streams map: it will never be removed if so.
  ASSERT_TRUE(Initialize());

  // Send a simple headers only request, and receive response.
  EXPECT_EQ(kFooResponseBody, client_->SendSynchronousRequest("/foo"));
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  // Now verify that the server is not waiting for a final FIN or RST.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  QuicSession* session = dispatcher->session_map().begin()->second;
  EXPECT_EQ(0u, QuicSessionPeer::GetLocallyClosedStreamsHighestOffset(
      session).size());
  server_thread_->Resume();
}

TEST_P(EndToEndTest, EnablePacingViaFlag) {
  // When pacing is enabled via command-line flag, it will always be enabled,
  // regardless of the config. or the specific congestion-control algorithm.
  ValueRestore<bool> old_flag(&FLAGS_quic_enable_pacing, true);
  ASSERT_TRUE(Initialize());

  client_->client()->WaitForCryptoHandshakeConfirmed();
  server_thread_->WaitForCryptoHandshakeConfirmed();

  // Pause the server so we can access the server's internals without races.
  server_thread_->Pause();
  QuicDispatcher* dispatcher =
      QuicServerPeer::GetDispatcher(server_thread_->server());
  ASSERT_EQ(1u, dispatcher->session_map().size());
  const QuicSentPacketManager& client_sent_packet_manager =
      client_->client()->session()->connection()->sent_packet_manager();
  const QuicSentPacketManager& server_sent_packet_manager =
      *GetSentPacketManagerFromFirstServerSession();
  EXPECT_TRUE(server_sent_packet_manager.using_pacing());
  EXPECT_TRUE(client_sent_packet_manager.using_pacing());
}

// A TestAckNotifierDelegate verifies that its OnAckNotification method has been
// called exactly once on destruction.
class TestAckNotifierDelegate : public QuicAckNotifier::DelegateInterface {
 public:
  TestAckNotifierDelegate() {}

  void OnAckNotification(int /*num_retransmitted_packets*/,
                         int /*num_retransmitted_bytes*/,
                         QuicTime::Delta /*delta_largest_observed*/) override {
    ASSERT_FALSE(has_been_notified_);
    has_been_notified_ = true;
  }

  bool has_been_notified() const { return has_been_notified_; }

 protected:
  // Object is ref counted.
  ~TestAckNotifierDelegate() override { EXPECT_TRUE(has_been_notified_); }

 private:
  bool has_been_notified_ = false;
};

TEST_P(EndToEndTest, AckNotifierWithPacketLossAndBlockedSocket) {
  // Verify that even in the presence of packet loss and occasionally blocked
  // socket,  an AckNotifierDelegate will get informed that the data it is
  // interested in has been ACKed. This tests end-to-end ACK notification, and
  // demonstrates that retransmissions do not break this functionality.
  ValueRestore<bool> old_flag(&FLAGS_quic_attach_ack_notifiers_to_packets,
                              true);
  ValueRestore<bool> old_flag2(&FLAGS_quic_ack_notifier_informed_on_serialized,
                               true);

  SetPacketLossPercentage(5);
  ASSERT_TRUE(Initialize());

  // Wait for the server SHLO before upping the packet loss.
  client_->client()->WaitForCryptoHandshakeConfirmed();
  SetPacketLossPercentage(30);
  client_writer_->set_fake_blocked_socket_percentage(10);

  // Create a POST request and send the headers only.
  HTTPMessage request(HttpConstants::HTTP_1_1, HttpConstants::POST, "/foo");
  request.set_has_complete_message(false);
  client_->SendMessage(request);

  // The TestAckNotifierDelegate will cause a failure if not notified.
  scoped_refptr<TestAckNotifierDelegate> delegate(new TestAckNotifierDelegate);

  // Test the AckNotifier's ability to track multiple packets by making the
  // request body exceed the size of a single packet.
  string request_string =
      "a request body bigger than one packet" + string(kMaxPacketSize, '.');

  // Send the request, and register the delegate for ACKs.
  client_->SendData(request_string, true, delegate.get());
  client_->WaitForResponse();
  EXPECT_EQ(kFooResponseBody, client_->response_body());
  EXPECT_EQ(200u, client_->response_headers()->parsed_response_code());

  // Send another request to flush out any pending ACKs on the server.
  client_->SendSynchronousRequest(request_string);

  // Pause the server to avoid races.
  server_thread_->Pause();
  // Make sure the delegate does get the notification it expects.
  while (!delegate->has_been_notified()) {
    // Waits for up to 50 ms.
    client_->client()->WaitForEvents();
  }
  server_thread_->Resume();
}

}  // namespace
}  // namespace test
}  // namespace tools
}  // namespace net