// Copyright 2023 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

#include "pw_bluetooth_sapphire/internal/host/l2cap/bredr_dynamic_channel.h"

#include <pw_async/fake_dispatcher_fixture.h>

#include <vector>

#include "pw_bluetooth_sapphire/internal/host/common/byte_buffer.h"
#include "pw_bluetooth_sapphire/internal/host/hci-spec/protocol.h"
#include "pw_bluetooth_sapphire/internal/host/l2cap/fake_signaling_channel.h"
#include "pw_bluetooth_sapphire/internal/host/l2cap/l2cap_defs.h"
#include "pw_bluetooth_sapphire/internal/host/testing/test_helpers.h"
#include "pw_unit_test/framework.h"

#pragma clang diagnostic ignored "-Wshadow"

namespace bt::l2cap::internal {
namespace {

// TODO(fxbug.dev/42056068): Add integration test with FakeChannelTest and
// BrEdrSignalingChannel using snooped connection data to verify signaling
// channel traffic.

constexpr uint16_t kPsm = 0x0001;
constexpr uint16_t kInvalidPsm = 0x0002;  // Valid PSMs are odd.
constexpr ChannelId kLocalCId = 0x0040;
constexpr ChannelId kLocalCId2 = 0x0041;
constexpr ChannelId kRemoteCId = 0x60a3;
constexpr ChannelId kBadCId = 0x003f;  // Not a dynamic channel.

constexpr ChannelParameters kChannelParams;
constexpr ChannelParameters kERTMChannelParams{
    RetransmissionAndFlowControlMode::kEnhancedRetransmission,
    std::nullopt,
    std::nullopt};

// Commands Reject

const StaticByteBuffer kRejNotUnderstood(
    // Reject Reason (Not Understood)
    0x00,
    0x00);

// Connection Requests

const StaticByteBuffer kConnReq(
    // PSM
    LowerBits(kPsm),
    UpperBits(kPsm),

    // Source CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId));

auto MakeConnectionRequest(ChannelId src_id, Psm psm) {
  return StaticByteBuffer(
      // PSM
      LowerBits(psm),
      UpperBits(psm),

      // Source CID
      LowerBits(src_id),
      UpperBits(src_id));
}

const StaticByteBuffer kInboundConnReq(
    // PSM
    LowerBits(kPsm),
    UpperBits(kPsm),

    // Source CID
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId));

const StaticByteBuffer kInboundInvalidPsmConnReq(
    // PSM
    LowerBits(kInvalidPsm),
    UpperBits(kInvalidPsm),

    // Source CID
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId));

const StaticByteBuffer kInboundBadCIdConnReq(
    // PSM
    LowerBits(kPsm),
    UpperBits(kPsm),

    // Source CID
    LowerBits(kBadCId),
    UpperBits(kBadCId));

// Connection Responses

const StaticByteBuffer kPendingConnRsp(
    // Destination CID
    0x00,
    0x00,

    // Source CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Result (Pending)
    0x01,
    0x00,

    // Status (Authorization Pending)
    0x02,
    0x00);

const StaticByteBuffer kPendingConnRspWithId(
    // Destination CID (Wrong endianness but valid)
    UpperBits(kRemoteCId),
    LowerBits(kRemoteCId),

    // Source CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Result (Pending)
    0x01,
    0x00,

    // Status (Authorization Pending)
    0x02,
    0x00);

auto MakeConnectionResponseWithResultPending(ChannelId src_id,
                                             ChannelId dst_id) {
  return StaticByteBuffer(
      // Destination CID
      LowerBits(dst_id),
      UpperBits(dst_id),

      // Source CID
      LowerBits(src_id),
      UpperBits(src_id),

      // Result (Pending)
      0x01,
      0x00,

      // Status (Authorization Pending)
      0x02,
      0x00);
}

const StaticByteBuffer kOkConnRsp(
    // Destination CID
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId),

    // Source CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Result (Successful)
    0x00,
    0x00,

    // Status (No further information available)
    0x00,
    0x00);

auto MakeConnectionResponse(ChannelId src_id, ChannelId dst_id) {
  return StaticByteBuffer(
      // Destination CID
      LowerBits(dst_id),
      UpperBits(dst_id),

      // Source CID
      LowerBits(src_id),
      UpperBits(src_id),

      // Result (Successful)
      0x00,
      0x00,

      // Status (No further information available)
      0x00,
      0x00);
}

const StaticByteBuffer kInvalidConnRsp(
    // Destination CID (Not a dynamic channel ID)
    LowerBits(kBadCId),
    UpperBits(kBadCId),

    // Source CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Result (Successful)
    0x00,
    0x00,

    // Status (No further information available)
    0x00,
    0x00);

const StaticByteBuffer kRejectConnRsp(
    // Destination CID (Invalid)
    LowerBits(kInvalidChannelId),
    UpperBits(kInvalidChannelId),

    // Source CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Result (No resources)
    0x04,
    0x00,

    // Status (No further information available)
    0x00,
    0x00);

const StaticByteBuffer kInboundOkConnRsp(
    // Destination CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Source CID
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId),

    // Result (Successful)
    0x00,
    0x00,

    // Status (No further information available)
    0x00,
    0x00);

const StaticByteBuffer kOutboundSourceCIdAlreadyAllocatedConnRsp(
    // Destination CID (Invalid)
    0x00,
    0x00,

    // Source CID (Invalid)
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId),

    // Result (Connection refused - source CID already allocated)
    0x07,
    0x00,

    // Status (No further information available)
    0x00,
    0x00);

const StaticByteBuffer kInboundBadPsmConnRsp(
    // Destination CID (Invalid)
    0x00,
    0x00,

    // Source CID
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId),

    // Result (PSM Not Supported)
    0x02,
    0x00,

    // Status (No further information available)
    0x00,
    0x00);

const StaticByteBuffer kInboundBadCIdConnRsp(
    // Destination CID (Invalid)
    0x00,
    0x00,

    // Source CID
    LowerBits(kBadCId),
    UpperBits(kBadCId),

    // Result (Invalid Source CID)
    0x06,
    0x00,

    // Status (No further information available)
    0x00,
    0x00);

// Disconnection Requests

const StaticByteBuffer kDisconReq(
    // Destination CID
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId),

    // Source CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId));

const StaticByteBuffer kInboundDisconReq(
    // Destination CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Source CID
    LowerBits(kRemoteCId),
    UpperBits(kRemoteCId));

// Disconnection Responses

const ByteBuffer& kInboundDisconRsp = kInboundDisconReq;

const ByteBuffer& kDisconRsp = kDisconReq;

// Configuration Requests

auto MakeConfigReqWithMtuAndRfc(ChannelId dest_cid,
                                uint16_t mtu,

                                RetransmissionAndFlowControlMode mode,
                                uint8_t tx_window,
                                uint8_t max_transmit,
                                uint16_t retransmission_timeout,
                                uint16_t monitor_timeout,
                                uint16_t mps) {
  return StaticByteBuffer(
      // Destination CID
      LowerBits(dest_cid),
      UpperBits(dest_cid),

      // Flags
      0x00,
      0x00,

      // MTU option (Type, Length, MTU value)
      0x01,
      0x02,
      LowerBits(mtu),
      UpperBits(mtu),

      // Retransmission & Flow Control option (Type, Length = 9, mode, unused
      // fields)
      0x04,
      0x09,
      static_cast<uint8_t>(mode),
      tx_window,
      max_transmit,
      LowerBits(retransmission_timeout),
      UpperBits(retransmission_timeout),
      LowerBits(monitor_timeout),
      UpperBits(monitor_timeout),
      LowerBits(mps),
      UpperBits(mps));
}

auto MakeConfigReqWithMtu(ChannelId dest_cid,
                          uint16_t mtu = kMaxMTU,
                          uint16_t flags = 0x0000) {
  return StaticByteBuffer(
      // Destination CID
      LowerBits(dest_cid),
      UpperBits(dest_cid),

      // Flags
      LowerBits(flags),
      UpperBits(flags),

      // MTU option (Type, Length, MTU value)
      0x01,
      0x02,
      LowerBits(mtu),
      UpperBits(mtu));
}

const ByteBuffer& kOutboundConfigReq = MakeConfigReqWithMtu(kRemoteCId);

const ByteBuffer& kOutboundConfigReqWithErtm = MakeConfigReqWithMtuAndRfc(
    kRemoteCId,
    kMaxInboundPduPayloadSize,
    RetransmissionAndFlowControlMode::kEnhancedRetransmission,
    kErtmMaxUnackedInboundFrames,
    kErtmMaxInboundRetransmissions,
    0,
    0,
    kMaxInboundPduPayloadSize);

const StaticByteBuffer kInboundConfigReq(
    // Destination CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Flags
    0x00,
    0x00);

// Use plausible ERTM parameters that do not necessarily match values in
// production. See Core Spec v5.0 Vol 3, Part A, Sec 5.4 for meanings.
constexpr uint8_t kErtmNFramesInTxWindow = 32;
constexpr uint8_t kErtmMaxTransmissions = 8;
constexpr uint16_t kMaxTxPduPayloadSize = 1024;

const StaticByteBuffer kInboundConfigReqWithERTM(
    // Destination CID
    LowerBits(kLocalCId),
    UpperBits(kLocalCId),

    // Flags
    0x00,
    0x00,

    // Retransmission & Flow Control option (Type, Length = 9, mode = ERTM,
    // arbitrary parameters)
    0x04,
    0x09,
    0x03,
    kErtmNFramesInTxWindow,
    kErtmMaxTransmissions,
    0x00,
    0x00,
    0x00,
    0x00,
    LowerBits(kMaxTxPduPayloadSize),
    UpperBits(kMaxTxPduPayloadSize),

    // FCS Option (Type, Length = 1) - turn off which we should accept and
    // ignore
    0x05,
    0x01,
    static_cast<uint8_t>(FcsType::kNoFcs));

// Configuration Responses

auto MakeEmptyConfigRsp(
    ChannelId src_id,
    ConfigurationResult result = ConfigurationResult::kSuccess,
    uint16_t flags = 0x0000) {
  return StaticByteBuffer(
      // Source CID
      LowerBits(src_id),
      UpperBits(src_id),

      // Flags
      LowerBits(flags),
      UpperBits(flags),

      // Result
      LowerBits(static_cast<uint16_t>(result)),
      UpperBits(static_cast<uint16_t>(result)));
}

const ByteBuffer& kOutboundEmptyContinuationConfigRsp = MakeEmptyConfigRsp(
    kRemoteCId, ConfigurationResult::kSuccess, kConfigurationContinuation);

const ByteBuffer& kInboundEmptyConfigRsp = MakeEmptyConfigRsp(kLocalCId);

const ByteBuffer& kUnknownIdConfigRsp = MakeEmptyConfigRsp(kBadCId);

const ByteBuffer& kOutboundEmptyPendingConfigRsp =
    MakeEmptyConfigRsp(kRemoteCId, ConfigurationResult::kPending);

const ByteBuffer& kInboundEmptyPendingConfigRsp =
    MakeEmptyConfigRsp(kLocalCId, ConfigurationResult::kPending);

auto MakeConfigRspWithMtu(
    ChannelId source_cid,
    uint16_t mtu,
    ConfigurationResult result = ConfigurationResult::kSuccess,
    uint16_t flags = 0x0000) {
  return StaticByteBuffer(
      // Source CID
      LowerBits(source_cid),
      UpperBits(source_cid),

      // Flags
      LowerBits(flags),
      UpperBits(flags),

      // Result
      LowerBits(static_cast<uint16_t>(result)),
      UpperBits(static_cast<uint16_t>(result)),

      // MTU option (Type, Length, MTU value)
      0x01,
      0x02,
      LowerBits(mtu),
      UpperBits(mtu));
}

const ByteBuffer& kOutboundOkConfigRsp =
    MakeConfigRspWithMtu(kRemoteCId, kDefaultMTU);

auto MakeConfigRspWithRfc(ChannelId source_cid,
                          ConfigurationResult result,
                          RetransmissionAndFlowControlMode mode,
                          uint8_t tx_window,
                          uint8_t max_transmit,
                          uint16_t retransmission_timeout,
                          uint16_t monitor_timeout,
                          uint16_t mps) {
  return StaticByteBuffer(
      // Source CID
      LowerBits(source_cid),
      UpperBits(source_cid),

      // Flags
      0x00,
      0x00,

      // Result
      LowerBits(static_cast<uint16_t>(result)),
      UpperBits(static_cast<uint16_t>(result)),

      // Retransmission & Flow Control option (Type, Length: 9, mode, unused
      // parameters)
      0x04,
      0x09,
      static_cast<uint8_t>(mode),
      tx_window,
      max_transmit,
      LowerBits(retransmission_timeout),
      UpperBits(retransmission_timeout),
      LowerBits(monitor_timeout),
      UpperBits(monitor_timeout),
      LowerBits(mps),
      UpperBits(mps));
}

const ByteBuffer& kInboundUnacceptableParamsWithRfcBasicConfigRsp =
    MakeConfigRspWithRfc(kLocalCId,
                         ConfigurationResult::kUnacceptableParameters,
                         RetransmissionAndFlowControlMode::kBasic,
                         0,
                         0,
                         0,
                         0,
                         0);

const ByteBuffer& kOutboundUnacceptableParamsWithRfcBasicConfigRsp =
    MakeConfigRspWithRfc(kRemoteCId,
                         ConfigurationResult::kUnacceptableParameters,
                         RetransmissionAndFlowControlMode::kBasic,
                         0,
                         0,
                         0,
                         0,
                         0);

const ByteBuffer& kOutboundUnacceptableParamsWithRfcERTMConfigRsp =
    MakeConfigRspWithRfc(
        kRemoteCId,
        ConfigurationResult::kUnacceptableParameters,
        RetransmissionAndFlowControlMode::kEnhancedRetransmission,
        0,
        0,
        0,
        0,
        0);

auto MakeConfigRspWithMtuAndRfc(ChannelId source_cid,
                                ConfigurationResult result,
                                RetransmissionAndFlowControlMode mode,
                                uint16_t mtu,
                                uint8_t tx_window,
                                uint8_t max_transmit,
                                uint16_t retransmission_timeout,
                                uint16_t monitor_timeout,
                                uint16_t mps) {
  return StaticByteBuffer(
      // Source CID
      LowerBits(source_cid),
      UpperBits(source_cid),

      // Flags
      0x00,
      0x00,

      // Result
      LowerBits(static_cast<uint16_t>(result)),
      UpperBits(static_cast<uint16_t>(result)),

      // MTU option (Type, Length, MTU value)
      0x01,
      0x02,
      LowerBits(mtu),
      UpperBits(mtu),

      // Retransmission & Flow Control option (Type, Length = 9, mode, ERTM
      // fields)
      0x04,
      0x09,
      static_cast<uint8_t>(mode),
      tx_window,
      max_transmit,
      LowerBits(retransmission_timeout),
      UpperBits(retransmission_timeout),
      LowerBits(monitor_timeout),
      UpperBits(monitor_timeout),
      LowerBits(mps),
      UpperBits(mps));
}

// Corresponds to kInboundConfigReqWithERTM
const ByteBuffer& kOutboundOkConfigRspWithErtm = MakeConfigRspWithMtuAndRfc(
    kRemoteCId,
    ConfigurationResult::kSuccess,
    RetransmissionAndFlowControlMode::kEnhancedRetransmission,
    kDefaultMTU,
    kErtmNFramesInTxWindow,
    kErtmMaxTransmissions,
    2000,
    12000,
    kMaxTxPduPayloadSize);

// Information Requests

auto MakeInfoReq(InformationType info_type) {
  const auto type = static_cast<uint16_t>(info_type);
  return StaticByteBuffer(LowerBits(type), UpperBits(type));
}

const ByteBuffer& kExtendedFeaturesInfoReq =
    MakeInfoReq(InformationType::kExtendedFeaturesSupported);

// Information Responses

auto MakeExtendedFeaturesInfoRsp(
    InformationResult result = InformationResult::kSuccess,
    ExtendedFeatures features = 0u) {
  const auto type =
      static_cast<uint16_t>(InformationType::kExtendedFeaturesSupported);
  const auto res = static_cast<uint16_t>(result);
  const auto features_bytes = ToBytes(features);
  return StaticByteBuffer(
      // Type
      LowerBits(type),
      UpperBits(type),

      // Result
      LowerBits(res),
      UpperBits(res),

      // Data
      features_bytes[0],
      features_bytes[1],
      features_bytes[2],
      features_bytes[3]);
}

const ByteBuffer& kExtendedFeaturesInfoRsp =
    MakeExtendedFeaturesInfoRsp(InformationResult::kSuccess);
const ByteBuffer& kExtendedFeaturesInfoRspWithERTM =
    MakeExtendedFeaturesInfoRsp(InformationResult::kSuccess,
                                kExtendedFeaturesBitEnhancedRetransmission);

class BrEdrDynamicChannelTest : public pw::async::test::FakeDispatcherFixture {
 public:
  BrEdrDynamicChannelTest() = default;
  ~BrEdrDynamicChannelTest() override = default;

 protected:
  // Import types for brevity.
  using DynamicChannelCallback = DynamicChannelRegistry::DynamicChannelCallback;
  using ServiceRequestCallback = DynamicChannelRegistry::ServiceRequestCallback;

  // TestLoopFixture overrides
  void SetUp() override {
    channel_close_cb_ = nullptr;
    service_request_cb_ = nullptr;
    signaling_channel_ =
        std::make_unique<testing::FakeSignalingChannel>(dispatcher());

    ext_info_transaction_id_ = EXPECT_OUTBOUND_REQ(
        *sig(), kInformationRequest, kExtendedFeaturesInfoReq.view());
    // TODO(fxbug.dev/42141538): Make these tests not rely on strict ordering of
    // channel IDs.
    registry_ = std::make_unique<BrEdrDynamicChannelRegistry>(
        sig(),
        fit::bind_member<&BrEdrDynamicChannelTest::OnChannelClose>(this),
        fit::bind_member<&BrEdrDynamicChannelTest::OnServiceRequest>(this),
        /*random_channel_ids=*/false);
  }

  void TearDown() override {
    RunUntilIdle();
    registry_ = nullptr;
    signaling_channel_ = nullptr;
    service_request_cb_ = nullptr;
    channel_close_cb_ = nullptr;
  }

  testing::FakeSignalingChannel* sig() const {
    return signaling_channel_.get();
  }

  BrEdrDynamicChannelRegistry* registry() const { return registry_.get(); }

  void set_channel_close_cb(DynamicChannelCallback close_cb) {
    channel_close_cb_ = std::move(close_cb);
  }

  void set_service_request_cb(ServiceRequestCallback service_request_cb) {
    service_request_cb_ = std::move(service_request_cb);
  }

  testing::FakeSignalingChannel::TransactionId ext_info_transaction_id() {
    return ext_info_transaction_id_;
  }

 private:
  void OnChannelClose(const DynamicChannel* channel) {
    if (channel_close_cb_) {
      channel_close_cb_(channel);
    }
  }

  // Default to rejecting all service requests if no test callback is set.
  std::optional<DynamicChannelRegistry::ServiceInfo> OnServiceRequest(Psm psm) {
    if (service_request_cb_) {
      return service_request_cb_(psm);
    }
    return std::nullopt;
  }

  DynamicChannelCallback channel_close_cb_;
  ServiceRequestCallback service_request_cb_;
  std::unique_ptr<testing::FakeSignalingChannel> signaling_channel_;
  std::unique_ptr<BrEdrDynamicChannelRegistry> registry_;
  testing::FakeSignalingChannel::TransactionId ext_info_transaction_id_;

  BT_DISALLOW_COPY_AND_ASSIGN_ALLOW_MOVE(BrEdrDynamicChannelTest);
};

TEST_F(BrEdrDynamicChannelTest,
       InboundConnectionResponseReusingChannelIdCausesInboundChannelFailure) {
  // make successful connection
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_TRUE(chan->IsConnected());
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kRemoteCId, chan->remote_cid());
    }
    open_cb_count++;
  };

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto chan) {
    EXPECT_TRUE(chan);
    close_cb_count++;
  });

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);
  EXPECT_EQ(0, close_cb_count);

  // simulate inbound request to make new connection using already allocated
  // remote CId
  sig()->ReceiveExpect(kConnectionRequest,
                       kInboundConnReq,
                       kOutboundSourceCIdAlreadyAllocatedConnRsp);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest,
       PeerConnectionResponseReusingChannelIdCausesOutboundChannelFailure) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  // make successful connection
  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_TRUE(chan->IsConnected());
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kRemoteCId, chan->remote_cid());
    }
    open_cb_count++;
  };

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto chan) {
    EXPECT_TRUE(chan);
    close_cb_count++;
  });

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);
  EXPECT_EQ(0, close_cb_count);

  // peer responds with already allocated remote CID
  const auto kConnReq2 = MakeConnectionRequest(kLocalCId2, kPsm);
  const auto kOkConnRspSamePeerCId =
      MakeConnectionResponse(kLocalCId2, kRemoteCId);

  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConnectionRequest,
      kConnReq2.view(),
      {SignalingChannel::Status::kSuccess, kOkConnRspSamePeerCId.view()});

  auto channel = BrEdrDynamicChannel::MakeOutbound(
      registry(), sig(), kPsm, kLocalCId2, kChannelParams, false);
  EXPECT_FALSE(channel->IsConnected());
  EXPECT_FALSE(channel->IsOpen());

  int close_cb_count2 = 0;
  set_channel_close_cb([&close_cb_count2](auto) { close_cb_count2++; });

  int open_cb_count2 = 0;
  channel->Open([&open_cb_count2] { open_cb_count2++; });

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_FALSE(channel->IsConnected());
  EXPECT_FALSE(channel->IsOpen());
  EXPECT_EQ(open_cb_count2, 1);
  EXPECT_EQ(close_cb_count2, 0);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(
    BrEdrDynamicChannelTest,
    PeerPendingConnectionResponseReusingChannelIdCausesOutboundChannelFailure) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  // make successful connection
  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_TRUE(chan->IsConnected());
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kRemoteCId, chan->remote_cid());
    }
    open_cb_count++;
  };

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto chan) {
    EXPECT_TRUE(chan);
    close_cb_count++;
  });

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);
  EXPECT_EQ(0, close_cb_count);

  // peer responds with already allocated remote CID
  const auto kConnReq2 = MakeConnectionRequest(kLocalCId2, kPsm);
  const auto kOkConnRspWithResultPendingSamePeerCId =
      MakeConnectionResponseWithResultPending(kLocalCId2, kRemoteCId);
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq2.view(),
                      {SignalingChannel::Status::kSuccess,
                       kOkConnRspWithResultPendingSamePeerCId.view()});

  int open_cb_count2 = 0;
  int close_cb_count2 = 0;
  set_channel_close_cb([&close_cb_count2](auto) { close_cb_count2++; });

  registry()->OpenOutbound(
      kPsm, kChannelParams, [&open_cb_count2](auto) { open_cb_count2++; });

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(open_cb_count2, 1);
  // A failed-to-open channel should not invoke the close callback.
  EXPECT_EQ(close_cb_count2, 0);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(
    BrEdrDynamicChannelTest,
    PeerConnectionResponseWithSameRemoteChannelIdAsPeerPendingConnectionResponseSucceeds) {
  const auto kOkPendingConnRsp =
      MakeConnectionResponseWithResultPending(kLocalCId, kRemoteCId);
  auto conn_rsp_id = EXPECT_OUTBOUND_REQ(
      *sig(),
      kConnectionRequest,
      kConnReq.view(),
      {SignalingChannel::Status::kSuccess, kOkPendingConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_TRUE(chan->IsConnected());
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kRemoteCId, chan->remote_cid());
    }
    open_cb_count++;
  };

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto) { close_cb_count++; });

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveResponses(
      conn_rsp_id, {{SignalingChannel::Status::kSuccess, kOkConnRsp.view()}}));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(open_cb_count, 1);
  EXPECT_EQ(close_cb_count, 0);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, ChannelDeletedBeforeConnectionResponse) {
  auto conn_id =
      EXPECT_OUTBOUND_REQ(*sig(), kConnectionRequest, kConnReq.view());

  // Build channel and operate it directly to be able to delete it.
  auto channel = BrEdrDynamicChannel::MakeOutbound(
      registry(), sig(), kPsm, kLocalCId, kChannelParams, false);
  ASSERT_TRUE(channel);

  int open_result_cb_count = 0;
  channel->Open([&open_result_cb_count] { open_result_cb_count++; });

  RETURN_IF_FATAL(RunUntilIdle());

  channel = nullptr;
  RETURN_IF_FATAL(
      sig()->ReceiveResponses(conn_id,
                              {{SignalingChannel::Status::kSuccess,
                                kOutboundEmptyPendingConfigRsp.view()}}));

  EXPECT_EQ(0, open_result_cb_count);

  // No disconnection transaction expected because the channel isn't actually
  // owned by the registry.
}

TEST_F(BrEdrDynamicChannelTest, FailConnectChannel) {
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConnectionRequest,
      kConnReq.view(),
      {SignalingChannel::Status::kSuccess, kRejectConnRsp.view()});

  // Build channel and operate it directly to be able to inspect it in the
  // connected but not open state.
  auto channel = BrEdrDynamicChannel::MakeOutbound(
      registry(), sig(), kPsm, kLocalCId, kChannelParams, false);
  EXPECT_FALSE(channel->IsConnected());
  EXPECT_FALSE(channel->IsOpen());
  EXPECT_EQ(kLocalCId, channel->local_cid());

  int open_result_cb_count = 0;
  auto open_result_cb = [&open_result_cb_count, &channel] {
    if (open_result_cb_count == 0) {
      EXPECT_FALSE(channel->IsConnected());
      EXPECT_FALSE(channel->IsOpen());
    }
    open_result_cb_count++;
  };
  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto) { close_cb_count++; });

  channel->Open(std::move(open_result_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_result_cb_count);
  EXPECT_FALSE(channel->IsConnected());
  EXPECT_FALSE(channel->IsOpen());
  EXPECT_EQ(kInvalidChannelId, channel->remote_cid());

  // A failed-to-open channel should not invoke the close callback.
  EXPECT_EQ(0, close_cb_count);

  // No disconnection transaction expected because the channel isn't actually
  // owned by the registry.
}

TEST_F(BrEdrDynamicChannelTest, ConnectChannelFailConfig) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kReject, kRejNotUnderstood.view()});

  // Build channel and operate it directly to be able to inspect it in the
  // connected but not open state.
  auto channel = BrEdrDynamicChannel::MakeOutbound(
      registry(), sig(), kPsm, kLocalCId, kChannelParams, false);
  EXPECT_FALSE(channel->IsConnected());
  EXPECT_FALSE(channel->IsOpen());
  EXPECT_EQ(kLocalCId, channel->local_cid());

  int open_result_cb_count = 0;
  auto open_result_cb = [&open_result_cb_count, &channel] {
    if (open_result_cb_count == 0) {
      EXPECT_TRUE(channel->IsConnected());
      EXPECT_FALSE(channel->IsOpen());
    }
    open_result_cb_count++;
  };
  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto) { close_cb_count++; });

  channel->Open(std::move(open_result_cb));
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel->IsConnected());

  // A connected channel should have a valid remote channel ID.
  EXPECT_EQ(kRemoteCId, channel->remote_cid());

  EXPECT_FALSE(channel->IsOpen());
  EXPECT_EQ(1, open_result_cb_count);

  // A failed-to-open channel should not invoke the close callback.
  EXPECT_EQ(0, close_cb_count);

  // No disconnection transaction expected because the channel isn't actually
  // owned by the registry.
}

TEST_F(BrEdrDynamicChannelTest, ConnectChannelFailInvalidResponse) {
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConnectionRequest,
      kConnReq.view(),
      {SignalingChannel::Status::kSuccess, kInvalidConnRsp.view()});

  // Build channel and operate it directly to be able to inspect it in the
  // connected but not open state.
  auto channel = BrEdrDynamicChannel::MakeOutbound(
      registry(), sig(), kPsm, kLocalCId, kChannelParams, false);

  int open_result_cb_count = 0;
  auto open_result_cb = [&open_result_cb_count, &channel] {
    if (open_result_cb_count == 0) {
      EXPECT_FALSE(channel->IsConnected());
      EXPECT_FALSE(channel->IsOpen());
    }
    open_result_cb_count++;
  };
  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto) { close_cb_count++; });

  channel->Open(std::move(open_result_cb));
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_FALSE(channel->IsConnected());
  EXPECT_FALSE(channel->IsOpen());
  EXPECT_EQ(1, open_result_cb_count);
  EXPECT_EQ(0, close_cb_count);

  // No disconnection transaction expected because the channel isn't actually
  // owned by the registry.
}

TEST_F(BrEdrDynamicChannelTest,
       OutboundFailsAfterRtxExpiryForConnectionResponse) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kTimeOut, BufferView()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      EXPECT_FALSE(chan);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  // FakeSignalingChannel doesn't need to be clocked in order to simulate a
  // timeout.
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest,
       OutboundFailsAfterErtxExpiryForConnectionResponse) {
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConnectionRequest,
      kConnReq.view(),
      {SignalingChannel::Status::kSuccess, kPendingConnRsp.view()},
      {SignalingChannel::Status::kTimeOut, BufferView()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      EXPECT_FALSE(chan);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  // FakeSignalingChannel doesn't need to be clocked in order to simulate a
  // timeout.
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_cb_count);
}

// In L2CAP Test Spec v5.0.2, this is L2CAP/COS/CED/BV-08-C [Disconnect on
// Timeout].
TEST_F(BrEdrDynamicChannelTest,
       OutboundFailsAndDisconnectsAfterRtxExpiryForConfigurationResponse) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConfigurationRequest,
                      kOutboundConfigReq.view(),
                      {SignalingChannel::Status::kTimeOut, BufferView()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kTimeOut, BufferView()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      EXPECT_FALSE(chan);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  // FakeSignalingChannel doesn't need to be clocked in order to simulate a
  // timeout.
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_cb_count);
}

// Simulate a ERTX timer expiry after a Configuration Response with "Pending"
// status.
TEST_F(BrEdrDynamicChannelTest,
       OutboundFailsAndDisconnectsAfterErtxExpiryForConfigurationResponse) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConfigurationRequest,
                      kOutboundConfigReq.view(),
                      {SignalingChannel::Status::kSuccess,
                       kInboundEmptyPendingConfigRsp.view()},
                      {SignalingChannel::Status::kTimeOut, BufferView()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kTimeOut, BufferView()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      EXPECT_FALSE(chan);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  // FakeSignalingChannel doesn't need to be clocked in order to simulate a
  // timeout.
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, OpenAndLocalCloseChannel) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_TRUE(chan->IsConnected());
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kRemoteCId, chan->remote_cid());
      EXPECT_EQ(RetransmissionAndFlowControlMode::kBasic, chan->info().mode);
    }
    open_cb_count++;
  };

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto chan) {
    EXPECT_TRUE(chan);
    close_cb_count++;
  });

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);
  EXPECT_EQ(0, close_cb_count);

  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_cb_count);

  // Local channel closure shouldn't trigger the close callback.
  EXPECT_EQ(0, close_cb_count);

  // Callback passed to CloseChannel should be called nonetheless.
  EXPECT_TRUE(channel_close_cb_called);

  // Repeated closure of the same channel should not have any effect.
  channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  EXPECT_TRUE(channel_close_cb_called);
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_cb_count);
  EXPECT_EQ(0, close_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, OpenAndRemoteCloseChannel) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) { open_cb_count++; };

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto chan) {
    ASSERT_TRUE(chan);
    EXPECT_FALSE(chan->IsOpen());
    EXPECT_FALSE(chan->IsConnected());
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(kRemoteCId, chan->remote_cid());
    close_cb_count++;
  });

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);
  EXPECT_EQ(0, close_cb_count);

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kDisconnectionRequest, kInboundDisconReq, kInboundDisconRsp));

  EXPECT_EQ(1, open_cb_count);

  // Remote channel closure should trigger the close callback.
  EXPECT_EQ(1, close_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, OpenChannelWithPendingConn) {
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConnectionRequest,
      kConnReq.view(),
      {SignalingChannel::Status::kSuccess, kPendingConnRsp.view()},
      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  registry()->OpenOutbound(kPsm, kChannelParams, [&open_cb_count](auto chan) {
    open_cb_count++;
    ASSERT_TRUE(chan);
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(kRemoteCId, chan->remote_cid());
  });

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, OpenChannelMismatchConnRsp) {
  // The first Connection Response (pending) has a different ID than the final
  // Connection Response (success).
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConnectionRequest,
      kConnReq.view(),
      {SignalingChannel::Status::kSuccess, kPendingConnRspWithId.view()},
      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  registry()->OpenOutbound(kPsm, kChannelParams, [&open_cb_count](auto chan) {
    open_cb_count++;
    ASSERT_TRUE(chan);
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(kRemoteCId, chan->remote_cid());
  });

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, OpenChannelConfigPending) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess,
       kOutboundEmptyPendingConfigRsp.view()},
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  registry()->OpenOutbound(kPsm, kChannelParams, [&open_cb_count](auto chan) {
    open_cb_count++;
    ASSERT_TRUE(chan);
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(kRemoteCId, chan->remote_cid());
  });

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, OpenChannelRemoteDisconnectWhileConfiguring) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  auto config_id = EXPECT_OUTBOUND_REQ(
      *sig(), kConfigurationRequest, kOutboundConfigReq.view());

  int open_cb_count = 0;
  registry()->OpenOutbound(kPsm, kChannelParams, [&open_cb_count](auto chan) {
    open_cb_count++;
    EXPECT_FALSE(chan);
  });

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kDisconnectionRequest, kInboundDisconReq, kInboundDisconRsp));

  // Response handler should return false ("no more responses") when called, so
  // trigger single responses rather than a set of two.
  RETURN_IF_FATAL(
      sig()->ReceiveResponses(config_id,
                              {{SignalingChannel::Status::kSuccess,
                                kOutboundEmptyPendingConfigRsp.view()}}));
  RETURN_IF_FATAL(sig()->ReceiveResponses(
      config_id,
      {{SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()}}));

  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, ChannelIdNotReusedUntilDisconnectionCompletes) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  auto disconn_id =
      EXPECT_OUTBOUND_REQ(*sig(), kDisconnectionRequest, kDisconReq.view());

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    ASSERT_TRUE(chan);
    open_cb_count++;
  };

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto chan) {
    EXPECT_TRUE(chan);
    close_cb_count++;
  });

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  // Complete opening the channel.
  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, open_cb_count);
  EXPECT_EQ(0, close_cb_count);

  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());

  // Disconnection Response hasn't been received yet so the second channel
  // should use a different channel ID.
  const StaticByteBuffer kSecondChannelConnReq(
      // PSM
      LowerBits(kPsm),
      UpperBits(kPsm),

      // Source CID
      LowerBits(kLocalCId + 1),
      UpperBits(kLocalCId + 1));

  EXPECT_OUTBOUND_REQ(*sig(), kConnectionRequest, kSecondChannelConnReq.view());
  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  // CloseChannel callback hasn't been called either.
  EXPECT_FALSE(channel_close_cb_called);

  // Complete the disconnection on the first channel.
  RETURN_IF_FATAL(sig()->ReceiveResponses(
      disconn_id, {{SignalingChannel::Status::kSuccess, kDisconRsp.view()}}));

  EXPECT_TRUE(channel_close_cb_called);

  // Now the first channel ID gets reused.
  EXPECT_OUTBOUND_REQ(*sig(), kConnectionRequest, kConnReq.view());
  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));
}

// DisconnectDoneCallback is load-bearing as a signal for the registry to delete
// a channel's state and recycle its channel ID, so test that it's called even
// when the peer doesn't actually send a Disconnect Response.
TEST_F(BrEdrDynamicChannelTest,
       DisconnectDoneCallbackCalledAfterDisconnectResponseTimeOut) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  // Build channel and operate it directly to be able to disconnect it.
  auto channel = BrEdrDynamicChannel::MakeOutbound(
      registry(), sig(), kPsm, kLocalCId, kChannelParams, false);
  ASSERT_TRUE(channel);
  channel->Open([] {});

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_TRUE(channel->IsConnected());

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kTimeOut, BufferView()});

  bool disconnect_done_cb_called = false;
  channel->Disconnect(
      [&disconnect_done_cb_called] { disconnect_done_cb_called = true; });
  EXPECT_FALSE(channel->IsConnected());

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_TRUE(disconnect_done_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, OpenChannelConfigWrongId) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kUnknownIdConfigRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  registry()->OpenOutbound(kPsm, kChannelParams, [&open_cb_count](auto chan) {
    open_cb_count++;
    EXPECT_FALSE(chan);
  });

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpectRejectInvalidChannelId(
      kConfigurationRequest, kInboundConfigReq, kLocalCId, kInvalidChannelId));

  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, InboundConnectionOk) {
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  DynamicChannelCallback open_cb = [&open_cb_count](auto chan) {
    open_cb_count++;
    ASSERT_TRUE(chan);
    EXPECT_EQ(kPsm, chan->psm());
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(kRemoteCId, chan->remote_cid());
  };

  int service_request_cb_count = 0;
  auto service_request_cb = [&service_request_cb_count,
                             open_cb = std::move(open_cb)](Psm psm) mutable
      -> std::optional<DynamicChannelRegistry::ServiceInfo> {
    service_request_cb_count++;
    EXPECT_EQ(kPsm, psm);
    if (psm == kPsm) {
      return DynamicChannelRegistry::ServiceInfo(kChannelParams,
                                                 open_cb.share());
    }
    return std::nullopt;
  };

  set_service_request_cb(std::move(service_request_cb));

  int close_cb_count = 0;
  set_channel_close_cb([&close_cb_count](auto chan) { close_cb_count++; });

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConnectionRequest, kInboundConnReq, kInboundOkConnRsp));
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, service_request_cb_count);
  EXPECT_EQ(0, open_cb_count);

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1, service_request_cb_count);
  EXPECT_EQ(1, open_cb_count);

  registry()->CloseChannel(kLocalCId, [] {});
  EXPECT_EQ(0, close_cb_count);
}

TEST_F(BrEdrDynamicChannelTest,
       InboundConnectionRemoteDisconnectWhileConfiguring) {
  auto config_id = EXPECT_OUTBOUND_REQ(
      *sig(), kConfigurationRequest, kOutboundConfigReq.view());

  int open_cb_count = 0;
  DynamicChannelCallback open_cb = [&open_cb_count](auto chan) {
    open_cb_count++;
    FAIL() << "Failed-to-open inbound channels shouldn't trip open callback";
  };

  int service_request_cb_count = 0;
  auto service_request_cb = [&service_request_cb_count,
                             open_cb = std::move(open_cb)](Psm psm) mutable
      -> std::optional<DynamicChannelRegistry::ServiceInfo> {
    service_request_cb_count++;
    EXPECT_EQ(kPsm, psm);
    if (psm == kPsm) {
      return DynamicChannelRegistry::ServiceInfo(kChannelParams,
                                                 open_cb.share());
    }
    return std::nullopt;
  };

  set_service_request_cb(std::move(service_request_cb));

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConnectionRequest, kInboundConnReq, kInboundOkConnRsp));
  RunUntilIdle();

  EXPECT_EQ(1, service_request_cb_count);
  EXPECT_EQ(0, open_cb_count);

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));
  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kDisconnectionRequest, kInboundDisconReq, kInboundDisconRsp));

  // Drop response received after the channel is disconnected.
  RETURN_IF_FATAL(sig()->ReceiveResponses(
      config_id,
      {{SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()}}));

  EXPECT_EQ(1, service_request_cb_count);

  // Channel that failed to open shouldn't have triggered channel open callback.
  EXPECT_EQ(0, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, InboundConnectionInvalidPsm) {
  auto service_request_cb =
      [](Psm psm) -> std::optional<DynamicChannelRegistry::ServiceInfo> {
    // Write user code that accepts the invalid PSM, but control flow may not
    // reach here.
    EXPECT_EQ(kInvalidPsm, psm);
    if (psm == kInvalidPsm) {
      return DynamicChannelRegistry::ServiceInfo(
          kChannelParams, [](auto /*unused*/) {
            FAIL() << "Channel should fail to open for PSM";
          });
    }
    return std::nullopt;
  };

  set_service_request_cb(std::move(service_request_cb));

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConnectionRequest, kInboundInvalidPsmConnReq, kInboundBadPsmConnRsp));
  RunUntilIdle();
}

TEST_F(BrEdrDynamicChannelTest, InboundConnectionUnsupportedPsm) {
  int service_request_cb_count = 0;
  auto service_request_cb =
      [&service_request_cb_count](
          Psm psm) -> std::optional<DynamicChannelRegistry::ServiceInfo> {
    service_request_cb_count++;
    EXPECT_EQ(kPsm, psm);

    // Reject the service request.
    return std::nullopt;
  };

  set_service_request_cb(std::move(service_request_cb));

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConnectionRequest, kInboundConnReq, kInboundBadPsmConnRsp));
  RunUntilIdle();

  EXPECT_EQ(1, service_request_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, InboundConnectionInvalidSrcCId) {
  auto service_request_cb =
      [](Psm psm) -> std::optional<DynamicChannelRegistry::ServiceInfo> {
    // Control flow may not reach here.
    EXPECT_EQ(kPsm, psm);
    if (psm == kPsm) {
      return DynamicChannelRegistry::ServiceInfo(
          kChannelParams, [](auto /*unused*/) {
            FAIL() << "Channel from src_cid should fail to open";
          });
    }
    return std::nullopt;
  };

  set_service_request_cb(std::move(service_request_cb));

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConnectionRequest, kInboundBadCIdConnReq, kInboundBadCIdConnRsp));
  RunUntilIdle();
}

TEST_F(BrEdrDynamicChannelTest, RejectConfigReqWithUnknownOptions) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  size_t open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    EXPECT_FALSE(chan);
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  const StaticByteBuffer kInboundConfigReqUnknownOption(
      // Destination CID
      LowerBits(kLocalCId),
      UpperBits(kLocalCId),

      // Flags
      0x00,
      0x00,

      // Unknown Option: Type, Length, Data
      0x70,
      0x01,
      0x02);

  const StaticByteBuffer kOutboundConfigRspUnknownOption(
      // Source CID
      LowerBits(kRemoteCId),
      UpperBits(kRemoteCId),

      // Flags
      0x00,
      0x00,

      // Result (Failure - unknown options)
      0x03,
      0x00,

      // Unknown Option: Type, Length, Data
      0x70,
      0x01,
      0x02);

  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqUnknownOption,
                                       kOutboundConfigRspUnknownOption));

  EXPECT_EQ(0u, open_cb_count);

  RunUntilIdle();
}

TEST_F(BrEdrDynamicChannelTest,
       ClampErtmChannelInfoMaxTxSduSizeToMaxPduPayloadSize) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReqWithErtm.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  const auto kPeerMps = 1024;
  const auto kPeerMtu = kPeerMps + 1;
  bool channel_opened = false;
  auto open_cb = [&](auto chan) {
    channel_opened = true;
    ASSERT_TRUE(chan);
    EXPECT_TRUE(chan->IsOpen());
    EXPECT_EQ(kLocalCId, chan->local_cid());

    // Note that max SDU size is the peer's MPS because it's smaller than its
    // MTU.
    EXPECT_EQ(kPeerMps, chan->info().max_tx_sdu_size);
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(RunUntilIdle());

  const auto kInboundConfigReq = MakeConfigReqWithMtuAndRfc(
      kLocalCId,
      kPeerMtu,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      kErtmNFramesInTxWindow,
      kErtmMaxTransmissions,
      0,
      0,
      kPeerMps);
  const auto kOutboundConfigRsp = MakeConfigRspWithMtuAndRfc(
      kRemoteCId,
      ConfigurationResult::kSuccess,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      kPeerMtu,
      kErtmNFramesInTxWindow,
      kErtmMaxTransmissions,
      2000,
      12000,
      kPeerMps);

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundConfigRsp));

  EXPECT_TRUE(channel_opened);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

struct ReceiveMtuTestParams {
  std::optional<uint16_t> request_mtu;
  uint16_t response_mtu;
  ConfigurationResult response_status;
};
class ReceivedMtuTest
    : public BrEdrDynamicChannelTest,
      public ::testing::WithParamInterface<ReceiveMtuTestParams> {};

TEST_P(ReceivedMtuTest, ResponseMtuAndStatus) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  bool channel_opened = false;
  auto open_cb = [&](auto chan) {
    channel_opened = true;
    ASSERT_TRUE(chan);
    EXPECT_TRUE(chan->IsOpen());
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(chan->info().max_tx_sdu_size, GetParam().response_mtu);
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  const auto kOutboundConfigRsp = MakeConfigRspWithMtu(
      kRemoteCId, GetParam().response_mtu, GetParam().response_status);

  if (GetParam().request_mtu) {
    RETURN_IF_FATAL(sig()->ReceiveExpect(
        kConfigurationRequest,
        MakeConfigReqWithMtu(kLocalCId, *GetParam().request_mtu),
        kOutboundConfigRsp));
  } else {
    RETURN_IF_FATAL(sig()->ReceiveExpect(
        kConfigurationRequest, kInboundConfigReq, kOutboundConfigRsp));
  }

  EXPECT_EQ(GetParam().response_status == ConfigurationResult::kSuccess,
            channel_opened);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

INSTANTIATE_TEST_SUITE_P(
    BrEdrDynamicChannelTest,
    ReceivedMtuTest,
    ::testing::Values(
        ReceiveMtuTestParams{
            std::nullopt, kDefaultMTU, ConfigurationResult::kSuccess},
        ReceiveMtuTestParams{
            kMinACLMTU, kMinACLMTU, ConfigurationResult::kSuccess},
        ReceiveMtuTestParams{kMinACLMTU - 1,
                             kMinACLMTU,
                             ConfigurationResult::kUnacceptableParameters},
        ReceiveMtuTestParams{
            kDefaultMTU + 1, kDefaultMTU + 1, ConfigurationResult::kSuccess}));

class ConfigRspWithMtuTest : public BrEdrDynamicChannelTest,
                             public ::testing::WithParamInterface<
                                 std::optional<uint16_t> /*response mtu*/> {};

TEST_P(ConfigRspWithMtuTest, ConfiguredLocalMtu) {
  const auto kExpectedConfiguredLocalMtu = GetParam() ? *GetParam() : kMaxMTU;

  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});

  const auto kInboundConfigRspWithParamMtu =
      MakeConfigRspWithMtu(kLocalCId, GetParam() ? *GetParam() : 0);
  if (GetParam()) {
    EXPECT_OUTBOUND_REQ(*sig(),
                        kConfigurationRequest,
                        kOutboundConfigReq.view(),
                        {SignalingChannel::Status::kSuccess,
                         kInboundConfigRspWithParamMtu.view()});
  } else {
    EXPECT_OUTBOUND_REQ(
        *sig(),
        kConfigurationRequest,
        kOutboundConfigReq.view(),
        {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  }

  size_t open_cb_count = 0;
  auto open_cb = [&](auto chan) {
    EXPECT_TRUE(chan->IsOpen());
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(kExpectedConfiguredLocalMtu, chan->info().max_rx_sdu_size);
    open_cb_count++;
  };
  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1u, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_P(ConfigRspWithMtuTest, ConfiguredLocalMtuWithPendingRsp) {
  const auto kExpectedConfiguredLocalMtu = GetParam() ? *GetParam() : kMaxMTU;

  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});

  const auto kInboundPendingConfigRspWithMtu = MakeConfigRspWithMtu(
      kLocalCId, GetParam() ? *GetParam() : 0, ConfigurationResult::kPending);
  if (GetParam()) {
    EXPECT_OUTBOUND_REQ(
        *sig(),
        kConfigurationRequest,
        kOutboundConfigReq.view(),
        {SignalingChannel::Status::kSuccess,
         kInboundPendingConfigRspWithMtu.view()},
        {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  } else {
    EXPECT_OUTBOUND_REQ(
        *sig(),
        kConfigurationRequest,
        kOutboundConfigReq.view(),
        {SignalingChannel::Status::kSuccess,
         kInboundEmptyPendingConfigRsp.view()},
        {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  }

  size_t open_cb_count = 0;
  auto open_cb = [&](auto chan) {
    EXPECT_TRUE(chan->IsOpen());
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(kExpectedConfiguredLocalMtu, chan->info().max_rx_sdu_size);
    open_cb_count++;
  };
  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  EXPECT_EQ(1u, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

INSTANTIATE_TEST_SUITE_P(BrEdrDynamicChannelTest,
                         ConfigRspWithMtuTest,
                         ::testing::Values(std::nullopt, kMinACLMTU));

TEST_F(BrEdrDynamicChannelTest, RespondsToInboundExtendedFeaturesRequest) {
  const auto kExpectedExtendedFeatures =
      kExtendedFeaturesBitFixedChannels | kExtendedFeaturesBitFCSOption |
      kExtendedFeaturesBitEnhancedRetransmission;
  const auto kExpectedExtendedFeaturesInfoRsp = MakeExtendedFeaturesInfoRsp(
      InformationResult::kSuccess, kExpectedExtendedFeatures);
  sig()->ReceiveExpect(kInformationRequest,
                       kExtendedFeaturesInfoReq,
                       kExpectedExtendedFeaturesInfoRsp);
}

TEST_F(BrEdrDynamicChannelTest, ExtendedFeaturesResponseSaved) {
  const auto kExpectedExtendedFeatures =
      kExtendedFeaturesBitFixedChannels | kExtendedFeaturesBitFCSOption |
      kExtendedFeaturesBitEnhancedRetransmission;
  const auto kInfoRsp = MakeExtendedFeaturesInfoRsp(InformationResult::kSuccess,
                                                    kExpectedExtendedFeatures);

  EXPECT_FALSE(registry()->extended_features());

  sig()->ReceiveResponses(
      ext_info_transaction_id(),
      {{SignalingChannel::Status::kSuccess, kInfoRsp.view()}});
  EXPECT_TRUE(registry()->extended_features());
  EXPECT_EQ(kExpectedExtendedFeatures, *registry()->extended_features());
}

TEST_F(BrEdrDynamicChannelTest, ExtendedFeaturesResponseInvalidFailureResult) {
  constexpr auto kResult = static_cast<InformationResult>(0xFFFF);
  const auto kInfoRsp = MakeExtendedFeaturesInfoRsp(kResult);

  EXPECT_FALSE(registry()->extended_features());

  sig()->ReceiveResponses(
      ext_info_transaction_id(),
      {{SignalingChannel::Status::kSuccess, kInfoRsp.view()}});
  EXPECT_FALSE(registry()->extended_features());
}

class InformationResultTest
    : public BrEdrDynamicChannelTest,
      public ::testing::WithParamInterface<InformationResult> {};

TEST_P(
    InformationResultTest,
    ERTMChannelWaitsForExtendedFeaturesResultBeforeFallingBackToBasicModeAndStartingConfigFlow) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});

  size_t open_cb_count = 0;
  auto open_cb = [&open_cb_count](auto chan) {
    EXPECT_EQ(kLocalCId, chan->local_cid());
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  // Config request should not be sent.
  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  const auto kExtendedFeaturesInfoRsp = MakeExtendedFeaturesInfoRsp(GetParam());
  sig()->ReceiveResponses(
      ext_info_transaction_id(),
      {{SignalingChannel::Status::kSuccess, kExtendedFeaturesInfoRsp.view()}});

  RunUntilIdle();

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  // Config should have been sent, so channel should be open.
  EXPECT_EQ(1u, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

INSTANTIATE_TEST_SUITE_P(
    BrEdrDynamicChannelTest,
    InformationResultTest,
    ::testing::Values(InformationResult::kSuccess,
                      InformationResult::kNotSupported,
                      static_cast<InformationResult>(0xFFFF)));

TEST_F(BrEdrDynamicChannelTest,
       ERTChannelDoesNotSendConfigReqBeforeConnRspReceived) {
  auto conn_id =
      EXPECT_OUTBOUND_REQ(*sig(), kConnectionRequest, kConnReq.view(), {});

  registry()->OpenOutbound(kPsm, kERTMChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  // Channel will be notified that extended features received.
  sig()->ReceiveResponses(
      ext_info_transaction_id(),
      {{SignalingChannel::Status::kSuccess, kExtendedFeaturesInfoRsp.view()}});

  // Config request should not be sent before connection response received.
  RunUntilIdle();

  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  sig()->ReceiveResponses(
      conn_id, {{SignalingChannel::Status::kSuccess, kOkConnRsp.view()}});
  RunUntilIdle();

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, SendAndReceiveERTMConfigReq) {
  constexpr uint16_t kPreferredMtu = kDefaultMTU + 1;
  const auto kExpectedOutboundConfigReq = MakeConfigReqWithMtuAndRfc(
      kRemoteCId,
      kPreferredMtu,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      kErtmMaxUnackedInboundFrames,
      kErtmMaxInboundRetransmissions,
      0,
      0,
      kMaxInboundPduPayloadSize);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kExpectedOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [kPreferredMtu, &open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_EQ(kLocalCId, chan->local_cid());

      // Check values of ChannelInfo fields.
      EXPECT_EQ(RetransmissionAndFlowControlMode::kEnhancedRetransmission,
                chan->info().mode);

      // Receive capability even under ERTM is based on MTU option, not on the
      // MPS in R&FC option.
      EXPECT_EQ(kPreferredMtu, chan->info().max_rx_sdu_size);

      // Inbound request has no MTU option, so the peer's receive capability is
      // the default.
      EXPECT_EQ(kDefaultMTU, chan->info().max_tx_sdu_size);

      // These values should match the contents of kInboundConfigReqWithERTM.
      EXPECT_EQ(kErtmNFramesInTxWindow, chan->info().n_frames_in_tx_window);
      EXPECT_EQ(kErtmMaxTransmissions, chan->info().max_transmissions);
      EXPECT_EQ(kMaxTxPduPayloadSize, chan->info().max_tx_pdu_payload_size);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(
      kPsm,
      {RetransmissionAndFlowControlMode::kEnhancedRetransmission,
       kPreferredMtu,
       std::nullopt},
      std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqWithERTM,
                                       kOutboundOkConfigRspWithErtm));

  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

// When the peer rejects ERTM with the result Unacceptable Parameters and the
// R&FC option specifying basic mode, the local device should send a new request
// with basic mode. When the peer then requests basic mode, it should be
// accepted. PTS: L2CAP/CMC/BV-03-C
TEST_F(BrEdrDynamicChannelTest, PeerRejectsERTM) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConfigurationRequest,
                      kOutboundConfigReqWithErtm.view(),
                      {SignalingChannel::Status::kSuccess,
                       kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_EQ(kLocalCId, chan->local_cid());
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

// Local device that prefers ERTM will renegotiate channel mode to basic mode
// after peer negotiates basic mode and rejects ERTM. PTS: L2CAP/CMC/BV-07-C
TEST_F(BrEdrDynamicChannelTest,
       RenegotiateChannelModeAfterPeerRequestsBasicModeAndRejectsERTM) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  auto config_req_id = EXPECT_OUTBOUND_REQ(
      *sig(), kConfigurationRequest, kOutboundConfigReqWithErtm.view());

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_TRUE(chan->IsOpen());
      EXPECT_EQ(kLocalCId, chan->local_cid());
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  RunUntilIdle();

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});
  RunUntilIdle();

  // Peer requests basic mode.
  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));
  RunUntilIdle();

  // New config request requesting basic mode should be sent in response to
  // unacceptable params response.
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  sig()->ReceiveResponses(
      config_req_id,
      {{SignalingChannel::Status::kSuccess,
        kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()}});

  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

// The local device should configure basic mode if peer does not indicate
// support for ERTM when it is preferred. PTS: L2CAP/CMC/BV-10-C
TEST_F(BrEdrDynamicChannelTest,
       PreferredModeIsERTMButERTMIsNotInPeerFeatureMask) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  registry()->OpenOutbound(kPsm, kERTMChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  // Receive features mask without ERTM bit set.
  sig()->ReceiveResponses(
      ext_info_transaction_id(),
      {{SignalingChannel::Status::kSuccess, kExtendedFeaturesInfoRsp.view()}});

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, RejectERTMRequestWhenPreferredModeIsBasic) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  registry()->OpenOutbound(kPsm, kChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  // Peer requests ERTM. Local device should reject with unacceptable params.
  RETURN_IF_FATAL(
      sig()->ReceiveExpect(kConfigurationRequest,
                           kInboundConfigReqWithERTM,
                           kOutboundUnacceptableParamsWithRfcBasicConfigRsp));

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

// Core Spec v5.1, Vol 3, Part A, Sec 5.4:
// If the mode in the remote device's negative Configuration Response does
// not match the mode in the remote device's Configuration Request then the
// local device shall disconnect the channel.
//
// Inbound config request received BEFORE outbound config request:
// <- ConfigurationRequest (with ERTM)
// -> ConfigurationResponse (Ok)
// -> ConfigurationRequest (with ERTM)
// <- ConfigurationResponse (Unacceptable, with Basic)
TEST_F(
    BrEdrDynamicChannelTest,
    DisconnectWhenInboundConfigReqReceivedBeforeOutboundConfigReqSentModeInInboundUnacceptableParamsConfigRspDoesNotMatchPeerConfigReq) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConfigurationRequest,
                      kOutboundConfigReqWithErtm.view(),
                      {SignalingChannel::Status::kSuccess,
                       kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      EXPECT_FALSE(chan);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  // Receive inbound config request.
  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqWithERTM,
                                       kOutboundOkConfigRspWithErtm));

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});
  // Send outbound config request.
  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);
}

// Same as above, but inbound config request received AFTER outbound
// configuration request:
// -> ConfigurationRequest (with ERTM)
// <- ConfigurationRequest (with ERTM)
// -> ConfigurationResponse (Ok)
// <- ConfigurationResponse (Unacceptable, with Basic)
TEST_F(
    BrEdrDynamicChannelTest,
    DisconnectWhenInboundConfigReqReceivedAfterOutboundConfigReqSentAndModeInInboundUnacceptableParamsConfigRspDoesNotMatchPeerConfigReq) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  const auto outbound_config_req_id = EXPECT_OUTBOUND_REQ(
      *sig(), kConfigurationRequest, kOutboundConfigReqWithErtm.view());
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      EXPECT_FALSE(chan);
    }
    open_cb_count++;
  };

  ChannelParameters params;
  params.mode = RetransmissionAndFlowControlMode::kEnhancedRetransmission;
  registry()->OpenOutbound(kPsm, params, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});
  // Send outbound config request.
  RunUntilIdle();

  // Receive inbound config request.
  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqWithERTM,
                                       kOutboundOkConfigRspWithErtm));

  sig()->ReceiveResponses(
      outbound_config_req_id,
      {{SignalingChannel::Status::kSuccess,
        kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()}});
  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest,
       DisconnectAfterReceivingTwoConfigRequestsWithoutDesiredMode) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      EXPECT_FALSE(chan);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  RETURN_IF_FATAL(
      sig()->ReceiveExpect(kConfigurationRequest,
                           kInboundConfigReqWithERTM,
                           kOutboundUnacceptableParamsWithRfcBasicConfigRsp));
  RETURN_IF_FATAL(
      sig()->ReceiveExpect(kConfigurationRequest,
                           kInboundConfigReqWithERTM,
                           kOutboundUnacceptableParamsWithRfcBasicConfigRsp));

  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest, RetryWhenPeerRejectsConfigReqWithBasicMode) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConfigurationRequest,
                      kOutboundConfigReq.view(),
                      {SignalingChannel::Status::kSuccess,
                       kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    EXPECT_FALSE(chan);
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(0, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest,
       RetryNTimesWhenPeerRejectsConfigReqWithBasicMode) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  uint8_t retry_limit = 2;
  for (int i = 0; i < retry_limit; i++) {
    EXPECT_OUTBOUND_REQ(
        *sig(),
        kConfigurationRequest,
        kOutboundConfigReq.view(),
        {SignalingChannel::Status::kSuccess,
         kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()});
  }
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    ASSERT_TRUE(chan == nullptr);
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest,
       RetryNTimesWhenPeerRejectsERTMConfigReqWithBasicMode) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConfigurationRequest,
                      kOutboundConfigReqWithErtm.view(),
                      {SignalingChannel::Status::kSuccess,
                       kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()});
  uint8_t retry_limit = 2;
  for (int i = 0; i < retry_limit; i++) {
    EXPECT_OUTBOUND_REQ(
        *sig(),
        kConfigurationRequest,
        kOutboundConfigReq.view(),
        {SignalingChannel::Status::kSuccess,
         kInboundUnacceptableParamsWithRfcBasicConfigRsp.view()});
  }
  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    ASSERT_TRUE(chan == nullptr);
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);
}

TEST_F(BrEdrDynamicChannelTest,
       SendUnacceptableParamsResponseWhenPeerRequestsUnsupportedChannelMode) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});

  registry()->OpenOutbound(kPsm, kERTMChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  // Retransmission mode is not supported.
  const auto kInboundConfigReqWithRetransmissionMode =
      MakeConfigReqWithMtuAndRfc(
          kLocalCId,
          kMaxMTU,
          RetransmissionAndFlowControlMode::kRetransmission,
          0,
          0,
          0,
          0,
          0);
  RETURN_IF_FATAL(
      sig()->ReceiveExpect(kConfigurationRequest,
                           kInboundConfigReqWithRetransmissionMode,
                           kOutboundUnacceptableParamsWithRfcBasicConfigRsp));

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(
    BrEdrDynamicChannelTest,
    SendUnacceptableParamsResponseWhenPeerRequestsUnsupportedChannelModeAndSupportsErtm) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(), kConfigurationRequest, kOutboundConfigReqWithErtm.view(), {});

  registry()->OpenOutbound(kPsm, kERTMChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(RunUntilIdle());

  // Retransmission mode is not supported.
  const auto kInboundConfigReqWithRetransmissionMode =
      MakeConfigReqWithMtuAndRfc(
          kLocalCId,
          kMaxMTU,
          RetransmissionAndFlowControlMode::kRetransmission,
          0,
          0,
          0,
          0,
          0);
  RETURN_IF_FATAL(
      sig()->ReceiveExpect(kConfigurationRequest,
                           kInboundConfigReqWithRetransmissionMode,
                           kOutboundUnacceptableParamsWithRfcERTMConfigRsp));

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest,
       SendUnacceptableParamsResponseWhenPeerRequestErtmWithZeroTxWindow) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReqWithErtm.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  registry()->OpenOutbound(kPsm, kERTMChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(RunUntilIdle());

  constexpr uint8_t kMaxTransmit = 31;
  constexpr auto kMps = kMaxTxPduPayloadSize;

  // TxWindow of zero is out of range.
  const auto kInboundConfigReqWithZeroTxWindow = MakeConfigReqWithMtuAndRfc(
      kLocalCId,
      kDefaultMTU,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      /*tx_window=*/0,
      /*max_transmit=*/kMaxTransmit,
      /*retransmission_timeout=*/0,
      /*monitor_timeout=*/0,
      /*mps=*/kMps);
  const auto kOutboundConfigRsp = MakeConfigRspWithRfc(
      kRemoteCId,
      ConfigurationResult::kUnacceptableParameters,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      /*tx_window=*/1,
      /*max_transmit=*/kMaxTransmit,
      /*retransmission_timeout=*/0,
      /*monitor_timeout=*/0,
      /*mps=*/kMps);
  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqWithZeroTxWindow,
                                       kOutboundConfigRsp));
}

TEST_F(BrEdrDynamicChannelTest,
       SendUnacceptableParamsResponseWhenPeerRequestErtmWithOversizeTxWindow) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReqWithErtm.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  registry()->OpenOutbound(kPsm, kERTMChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(RunUntilIdle());

  constexpr uint8_t kMaxTransmit = 31;
  constexpr auto kMps = kMaxTxPduPayloadSize;

  // TxWindow of 200 is out of range.
  const auto kInboundConfigReqWithOversizeTxWindow = MakeConfigReqWithMtuAndRfc(
      kLocalCId,
      kDefaultMTU,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      /*tx_window=*/200,
      /*max_transmit=*/kMaxTransmit,
      /*retransmission_timeout=*/0,
      /*monitor_timeout=*/0,
      /*mps=*/kMps);
  const auto kOutboundConfigRsp = MakeConfigRspWithRfc(
      kRemoteCId,
      ConfigurationResult::kUnacceptableParameters,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      /*tx_window=*/63,
      /*max_transmit=*/kMaxTransmit,
      /*retransmission_timeout=*/0,
      /*monitor_timeout=*/0,
      /*mps=*/kMps);
  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqWithOversizeTxWindow,
                                       kOutboundConfigRsp));

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest,
       SendUnacceptableParamsResponseWhenPeerRequestErtmWithUndersizeMps) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReqWithErtm.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  registry()->OpenOutbound(kPsm, kERTMChannelParams, {});

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(RunUntilIdle());

  constexpr uint8_t kMaxTransmit = 31;
  constexpr uint8_t kTxWindow = kErtmMaxUnackedInboundFrames;

  // MPS of 16 would not be able to fit a 48-byte (minimum MTU) SDU without
  // segmentation.
  const auto kInboundConfigReqWithUndersizeMps = MakeConfigReqWithMtuAndRfc(
      kLocalCId,
      kDefaultMTU,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      /*tx_window=*/kTxWindow,
      /*max_transmit=*/kMaxTransmit,
      /*retransmission_timeout=*/0,
      /*monitor_timeout=*/0,
      /*mps=*/16);
  const auto kOutboundConfigRsp = MakeConfigRspWithRfc(
      kRemoteCId,
      ConfigurationResult::kUnacceptableParameters,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      /*tx_window=*/kTxWindow,
      /*max_transmit=*/kMaxTransmit,
      /*retransmission_timeout=*/0,
      /*monitor_timeout=*/0,
      /*mps=*/kMinACLMTU);
  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqWithUndersizeMps,
                                       kOutboundConfigRsp));

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

// Local config with ERTM incorrectly accepted by peer, then peer requests basic
// mode which the local device must accept. These modes are incompatible, so the
// local device should default to Basic Mode.
TEST_F(BrEdrDynamicChannelTest,
       OpenBasicModeChannelAfterPeerAcceptsErtmThenPeerRequestsBasicMode) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReqWithErtm.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(RetransmissionAndFlowControlMode::kBasic, chan->info().mode);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  // Request ERTM.
  RunUntilIdle();

  // Peer requests basic mode.
  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  // Disconnect
  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

// Same as above, but the peer sends its positive response after sending its
// Basic Mode request.
TEST_F(BrEdrDynamicChannelTest,
       OpenBasicModeChannelAfterPeerRequestsBasicModeThenPeerAcceptsErtm) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReqWithErtm.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&open_cb_count](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(RetransmissionAndFlowControlMode::kBasic, chan->info().mode);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kERTMChannelParams, std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  // Peer requests basic mode.
  RETURN_IF_FATAL(sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp));

  // Local device will request ERTM.
  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});
  // Request ERTM & Disconnect
  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, MtuChannelParameterSentInConfigReq) {
  constexpr uint16_t kPreferredMtu = kDefaultMTU + 1;
  const auto kExpectedOutboundConfigReq =
      MakeConfigReqWithMtu(kRemoteCId, kPreferredMtu);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kExpectedOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kPreferredMtu, chan->info().max_rx_sdu_size);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(
      kPsm,
      {RetransmissionAndFlowControlMode::kBasic, kPreferredMtu, std::nullopt},
      open_cb);
  RunUntilIdle();

  sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp);
  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest, UseMinMtuWhenMtuChannelParameterIsBelowMin) {
  constexpr uint16_t kMtu = kMinACLMTU - 1;
  const auto kExpectedOutboundConfigReq =
      MakeConfigReqWithMtu(kRemoteCId, kMinACLMTU);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kExpectedOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kMinACLMTU, chan->info().max_rx_sdu_size);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(
      kPsm,
      {RetransmissionAndFlowControlMode::kBasic, kMtu, std::nullopt},
      open_cb);
  RunUntilIdle();

  sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kOutboundOkConfigRsp);
  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest,
       UseMaxPduPayloadSizeWhenMtuChannelParameterExceedsItWithErtm) {
  constexpr uint16_t kPreferredMtu = kMaxInboundPduPayloadSize + 1;
  const auto kExpectedOutboundConfigReq = MakeConfigReqWithMtuAndRfc(
      kRemoteCId,
      kMaxInboundPduPayloadSize,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      kErtmMaxUnackedInboundFrames,
      kErtmMaxInboundRetransmissions,
      0,
      0,
      kMaxInboundPduPayloadSize);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kExpectedOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  int open_cb_count = 0;
  auto open_cb = [&](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kMaxInboundPduPayloadSize, chan->info().max_rx_sdu_size);
    }
    open_cb_count++;
  };

  registry()->OpenOutbound(
      kPsm,
      {RetransmissionAndFlowControlMode::kEnhancedRetransmission,
       kPreferredMtu,
       std::nullopt},
      std::move(open_cb));

  RETURN_IF_FATAL(RunUntilIdle());

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});

  RETURN_IF_FATAL(sig()->ReceiveExpect(kConfigurationRequest,
                                       kInboundConfigReqWithERTM,
                                       kOutboundOkConfigRspWithErtm));

  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest,
       BasicModeChannelReportsChannelInfoWithBasicModeAndSduCapacities) {
  constexpr uint16_t kPreferredMtu = kDefaultMTU + 1;
  const auto kExpectedOutboundConfigReq =
      MakeConfigReqWithMtu(kRemoteCId, kPreferredMtu);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kExpectedOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  constexpr uint16_t kPeerMtu = kDefaultMTU + 2;
  const auto kInboundConfigReq = MakeConfigReqWithMtu(kLocalCId, kPeerMtu);

  int open_cb_count = 0;
  auto open_cb = [&](const DynamicChannel* chan) {
    ASSERT_TRUE(chan);
    EXPECT_EQ(kLocalCId, chan->local_cid());
    EXPECT_EQ(RetransmissionAndFlowControlMode::kBasic, chan->info().mode);
    EXPECT_EQ(kPreferredMtu, chan->info().max_rx_sdu_size);
    EXPECT_EQ(kPeerMtu, chan->info().max_tx_sdu_size);
    open_cb_count++;
  };

  registry()->OpenOutbound(
      kPsm,
      {RetransmissionAndFlowControlMode::kBasic, kPreferredMtu, std::nullopt},
      open_cb);
  RunUntilIdle();

  const ByteBuffer& kExpectedOutboundOkConfigRsp =
      MakeConfigRspWithMtu(kRemoteCId, kPeerMtu);
  sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReq, kExpectedOutboundOkConfigRsp);
  RunUntilIdle();
  EXPECT_EQ(1, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

TEST_F(BrEdrDynamicChannelTest,
       Receive2ConfigReqsWithContinuationFlagInFirstReq) {
  constexpr uint16_t kTxMtu = kMinACLMTU;
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReqWithErtm.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  const auto kInboundConfigReq0 =
      MakeConfigReqWithMtu(kLocalCId, kTxMtu, kConfigurationContinuation);
  const auto kOutboundConfigRsp1 = MakeConfigRspWithMtuAndRfc(
      kRemoteCId,
      ConfigurationResult::kSuccess,
      RetransmissionAndFlowControlMode::kEnhancedRetransmission,
      kTxMtu,
      kErtmNFramesInTxWindow,
      kErtmMaxTransmissions,
      2000,
      12000,
      kMaxTxPduPayloadSize);

  size_t open_cb_count = 0;
  auto open_cb = [&](const DynamicChannel* chan) {
    if (open_cb_count == 0) {
      ASSERT_TRUE(chan);
      EXPECT_EQ(kLocalCId, chan->local_cid());
      EXPECT_EQ(kTxMtu, chan->info().max_tx_sdu_size);
      EXPECT_EQ(RetransmissionAndFlowControlMode::kEnhancedRetransmission,
                chan->info().mode);
    }
    open_cb_count++;
  };

  sig()->ReceiveResponses(ext_info_transaction_id(),
                          {{SignalingChannel::Status::kSuccess,
                            kExtendedFeaturesInfoRspWithERTM.view()}});
  registry()->OpenOutbound(kPsm, kERTMChannelParams, open_cb);
  RunUntilIdle();

  sig()->ReceiveExpect(kConfigurationRequest,
                       kInboundConfigReq0,
                       kOutboundEmptyContinuationConfigRsp);
  RunUntilIdle();
  EXPECT_EQ(0u, open_cb_count);

  sig()->ReceiveExpect(
      kConfigurationRequest, kInboundConfigReqWithERTM, kOutboundConfigRsp1);
  RunUntilIdle();
  EXPECT_EQ(1u, open_cb_count);

  EXPECT_OUTBOUND_REQ(*sig(),
                      kDisconnectionRequest,
                      kDisconReq.view(),
                      {SignalingChannel::Status::kSuccess, kDisconRsp.view()});
  bool channel_close_cb_called = false;
  registry()->CloseChannel(kLocalCId, [&] { channel_close_cb_called = true; });
  RETURN_IF_FATAL(RunUntilIdle());
  EXPECT_TRUE(channel_close_cb_called);
}

// The unknown options from both configuration requests should be included when
// responding with the "unknown options" result.
TEST_F(
    BrEdrDynamicChannelTest,
    Receive2ConfigReqsWithContinuationFlagInFirstReqAndUnknownOptionInBothReqs) {
  EXPECT_OUTBOUND_REQ(*sig(),
                      kConnectionRequest,
                      kConnReq.view(),
                      {SignalingChannel::Status::kSuccess, kOkConnRsp.view()});
  EXPECT_OUTBOUND_REQ(
      *sig(),
      kConfigurationRequest,
      kOutboundConfigReq.view(),
      {SignalingChannel::Status::kSuccess, kInboundEmptyConfigRsp.view()});

  constexpr uint8_t kUnknownOption0Type = 0x70;
  constexpr uint8_t kUnknownOption1Type = 0x71;
  const StaticByteBuffer kInboundConfigReq0(
      // Destination CID
      LowerBits(kLocalCId),
      UpperBits(kLocalCId),
      // Flags (C = 1)
      0x01,
      0x00,
      // Unknown Option
      kUnknownOption0Type,
      0x01,
      0x00);
  const StaticByteBuffer kInboundConfigReq1(
      // Destination CID
      LowerBits(kLocalCId),
      UpperBits(kLocalCId),
      // Flags (C = 0)
      0x00,
      0x00,
      // Unknown Option
      kUnknownOption1Type,
      0x01,
      0x00);

  const StaticByteBuffer kOutboundUnknownOptionsConfigRsp(
      // Source CID
      LowerBits(kRemoteCId),
      UpperBits(kRemoteCId),
      // Flags (C = 0)
      0x00,
      0x00,
      // Result
      LowerBits(static_cast<uint16_t>(ConfigurationResult::kUnknownOptions)),
      UpperBits(static_cast<uint16_t>(ConfigurationResult::kUnknownOptions)),
      // Unknown Options
      kUnknownOption0Type,
      0x01,
      0x00,
      kUnknownOption1Type,
      0x01,
      0x00);

  size_t open_cb_count = 0;
  auto open_cb = [&](const DynamicChannel* chan) {
    EXPECT_FALSE(chan);
    open_cb_count++;
  };

  registry()->OpenOutbound(kPsm, kChannelParams, open_cb);
  RunUntilIdle();

  sig()->ReceiveExpect(kConfigurationRequest,
                       kInboundConfigReq0,
                       kOutboundEmptyContinuationConfigRsp);
  RunUntilIdle();
  EXPECT_EQ(0u, open_cb_count);

  sig()->ReceiveExpect(kConfigurationRequest,
                       kInboundConfigReq1,
                       kOutboundUnknownOptionsConfigRsp);
  RunUntilIdle();
  EXPECT_EQ(0u, open_cb_count);
}

}  // namespace
}  // namespace bt::l2cap::internal