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Commit 4db917c0 authored by Hansong Zhang's avatar Hansong Zhang Committed by android-build-merger
Browse files

L2CAP: Add Reassembler to separate outgoing and incoming queue 

am: 8e8badfb

Change-Id: Ia28c80a0913d6a7427f140d8a6fb788357a73762
parents 0bdf3ed7 8e8badfb

system/gd/l2cap/Android.bp

+2 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ filegroup { 
        "classic/internal/signalling_manager.cc",

        "classic/l2cap_classic_module.cc",

        "internal/scheduler_fifo.cc",

        "internal/reassembler.cc",

        "le/internal/fixed_channel_impl.cc",

        "le/internal/fixed_channel_service_manager_impl.cc",

        "le/internal/link_manager.cc",
@@ -39,6 +40,7 @@ filegroup { 
        "classic/internal/link_manager_test.cc",

        "classic/internal/signalling_manager_test.cc",

        "internal/fixed_channel_allocator_test.cc",

        "internal/reassembler_test.cc",

        "internal/scheduler_fifo_test.cc",

        "l2cap_packet_test.cc",

        "le/internal/fixed_channel_impl_test.cc",

system/gd/l2cap/classic/internal/link.cc

+5 −1
Original line number Diff line number Diff line
@@ -34,7 +34,8 @@ Link::Link(os::Handler* l2cap_handler, std::unique_ptr<hci::AclConnection> acl_c 
           l2cap::internal::ParameterProvider* parameter_provider,

           DynamicChannelServiceManagerImpl* dynamic_service_manager,

           FixedChannelServiceManagerImpl* fixed_service_manager)

    : l2cap_handler_(l2cap_handler), acl_connection_(std::move(acl_connection)), scheduler_(std::move(scheduler)),

    : l2cap_handler_(l2cap_handler), acl_connection_(std::move(acl_connection)),

      reassembler_(acl_connection_->GetAclQueueEnd(), l2cap_handler_), scheduler_(std::move(scheduler)),

      parameter_provider_(parameter_provider), dynamic_service_manager_(dynamic_service_manager),

      fixed_service_manager_(fixed_service_manager),

      signalling_manager_(l2cap_handler_, this, dynamic_service_manager_, &dynamic_channel_allocator_,
@@ -59,6 +60,7 @@ void Link::Disconnect() { 
std::shared_ptr<FixedChannelImpl> Link::AllocateFixedChannel(Cid cid, SecurityPolicy security_policy) {

  auto channel = fixed_channel_allocator_.AllocateChannel(cid, security_policy);

  scheduler_->AttachChannel(cid, channel->GetQueueDownEnd(), cid);

  reassembler_.AttachChannel(cid, channel->GetQueueDownEnd(), {});

  return channel;

}
@@ -87,6 +89,7 @@ std::shared_ptr<DynamicChannelImpl> Link::AllocateDynamicChannel(Psm psm, Cid re 
  auto channel = dynamic_channel_allocator_.AllocateChannel(psm, remote_cid, security_policy);

  if (channel != nullptr) {

    scheduler_->AttachChannel(channel->GetCid(), channel->GetQueueDownEnd(), channel->GetRemoteCid());

    reassembler_.AttachChannel(channel->GetCid(), channel->GetQueueDownEnd(), {});

  }

  return channel;

}
@@ -96,6 +99,7 @@ std::shared_ptr<DynamicChannelImpl> Link::AllocateReservedDynamicChannel(Cid res 
  auto channel = dynamic_channel_allocator_.AllocateReservedChannel(reserved_cid, psm, remote_cid, security_policy);

  if (channel != nullptr) {

    scheduler_->AttachChannel(channel->GetCid(), channel->GetQueueDownEnd(), channel->GetRemoteCid());

    reassembler_.AttachChannel(channel->GetCid(), channel->GetQueueDownEnd(), {});

  }

  return channel;

}

system/gd/l2cap/classic/internal/link.h

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include "l2cap/classic/internal/fixed_channel_service_manager_impl.h"

#include "l2cap/internal/fixed_channel_allocator.h"

#include "l2cap/internal/parameter_provider.h"

#include "l2cap/internal/reassembler.h"

#include "l2cap/internal/scheduler.h"

#include "os/alarm.h"

#include "os/handler.h"
@@ -87,6 +88,7 @@ class Link { 
  l2cap::internal::FixedChannelAllocator<FixedChannelImpl, Link> fixed_channel_allocator_{this, l2cap_handler_};

  DynamicChannelAllocator dynamic_channel_allocator_{this, l2cap_handler_};

  std::unique_ptr<hci::AclConnection> acl_connection_;

  l2cap::internal::Reassembler reassembler_;

  std::unique_ptr<l2cap::internal::Scheduler> scheduler_;

  l2cap::internal::ParameterProvider* parameter_provider_;

  DynamicChannelServiceManagerImpl* dynamic_service_manager_;

system/gd/l2cap/internal/reassembler.cc

0 → 100644
+92 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2019 The Android Open Source Project

 *

 * 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

 *

 *      http://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 "l2cap/internal/reassembler.h"

#include "common/bidi_queue.h"

#include "l2cap/cid.h"

#include "l2cap/l2cap_packets.h"

#include "packet/base_packet_builder.h"

#include "packet/packet_view.h"

#



namespace bluetooth {

namespace l2cap {

namespace internal {

Reassembler::Reassembler(LowerQueueUpEnd* link_queue_up_end, os::Handler* handler)

    : link_queue_up_end_(link_queue_up_end), handler_(handler) {

  ASSERT(link_queue_up_end_ != nullptr && handler_ != nullptr);

  link_queue_up_end_->RegisterDequeue(

      handler_, common::Bind(&Reassembler::link_queue_dequeue_callback, common::Unretained(this)));

}



Reassembler::~Reassembler() {

  link_queue_up_end_->UnregisterDequeue();

}



void Reassembler::AttachChannel(Cid cid, Reassembler::UpperQueueDownEnd* channel_down_end,

                                Reassembler::ChannelConfigurationOptions options) {

  ASSERT_LOG(channel_map_.find(cid) == channel_map_.end(), "Channel is already attached");

  auto pair = ChannelBufferAndOptions(channel_down_end, options);

  channel_map_.emplace(std::piecewise_construct, std::forward_as_tuple(cid),

                       std::forward_as_tuple(channel_down_end, options));

}



void Reassembler::DetachChannel(Cid cid) {

  ASSERT_LOG(channel_map_.find(cid) != channel_map_.end(), "Channel is not attached");

  channel_map_.erase(cid);

}



void Reassembler::link_queue_dequeue_callback() {

  auto packet = link_queue_up_end_->TryDequeue();

  auto basic_frame_view = BasicFrameView::Create(*packet);

  if (!basic_frame_view.IsValid()) {

    LOG_WARN("Received an invalid basic frame");

    return;

  }

  Cid cid = static_cast<Cid>(basic_frame_view.GetChannelId());

  auto channel = channel_map_.find(cid);

  if (channel == channel_map_.end()) {

    LOG_WARN("Received a packet with invalid cid: %d", cid);

    return;  // Channel is not attached to scheduler

  }



  auto channel_mode = channel->second.options_.mode_;

  switch (channel_mode) {

    case RetransmissionAndFlowControlModeOption::L2CAP_BASIC:

      handle_basic_mode_packet(cid, basic_frame_view);

      break;

    case RetransmissionAndFlowControlModeOption::ENHANCED_RETRANSMISSION:

      handle_enhanced_retransmission_mode_packet(cid, std::move(basic_frame_view));

      break;

    default:

      LOG_WARN("channel mode is not supported: %d", static_cast<int>(channel_mode));

  }

}



void Reassembler::handle_basic_mode_packet(Cid cid, const BasicFrameView& view) {

  auto channel = channel_map_.find(cid);

  auto& enqueue_buffer = channel->second.enqueue_buffer_;



  enqueue_buffer.Enqueue(std::make_unique<PacketView<kLittleEndian>>(view.GetPayload()), handler_);

}



void Reassembler::handle_enhanced_retransmission_mode_packet(Cid cid, BasicFrameView view) {

  LOG_ERROR("Enhanced retransmission mode is not implemented");

}



}  // namespace internal

}  // namespace l2cap

}  // namespace bluetooth

system/gd/l2cap/internal/reassembler.h

0 → 100644
+90 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2019 The Android Open Source Project

 *

 * 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

 *

 *      http://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.

 */



#pragma once



#include <unordered_map>

#include <utility>



#include "common/bidi_queue.h"

#include "l2cap/cid.h"

#include "l2cap/l2cap_packets.h"

#include "l2cap/mtu.h"

#include "os/queue.h"

#include "packet/base_packet_builder.h"

#include "packet/packet_view.h"



namespace bluetooth {

namespace l2cap {

namespace internal {



/**

 * Handle the reassembly of L2CAP SDU from PDU.

 * Dequeue incoming packets from LinkQueueUpEnd, and enqueue it to ChannelQueueDownEnd. Note: If a channel

 * cannot dequeue from ChannelQueueDownEnd so that the buffer for incoming packet is full, further incoming packets will

 * be dropped.

 * The Reassembler keeps the reference to ChannelImpl objects, because it needs to check channel mode and parameters.

 */

class Reassembler {

 public:

  using UpperEnqueue = packet::PacketView<packet::kLittleEndian>;

  using UpperDequeue = packet::BasePacketBuilder;

  using UpperQueueDownEnd = common::BidiQueueEnd<UpperEnqueue, UpperDequeue>;

  using LowerEnqueue = UpperDequeue;

  using LowerDequeue = UpperEnqueue;

  using LowerQueueUpEnd = common::BidiQueueEnd<LowerEnqueue, LowerDequeue>;



  Reassembler(LowerQueueUpEnd* link_queue_up_end, os::Handler* handler);

  ~Reassembler();



  struct ChannelConfigurationOptions {

    Mtu incoming_mtu_ = kDefaultClassicMtu;

    RetransmissionAndFlowControlModeOption mode_ = RetransmissionAndFlowControlModeOption::L2CAP_BASIC;

    // TODO: Add all RetransmissionAndFlowControlConfigurationOptions

    FcsType fcs_type_ = FcsType::NO_FCS;

  };



  /**

   * Attach a channel for packet reassembly.

   * If the channel is reconfigured, signalling manager should detach channel and attach channel again.

   */

  void AttachChannel(Cid cid, UpperQueueDownEnd* channel_down_end, ChannelConfigurationOptions options);



  /**

   * Detach a channel for packet reassembly. Incoming packets won't be delivered to the specified cid.

   */

  void DetachChannel(Cid cid);



 private:

  struct ChannelBufferAndOptions {

    ChannelBufferAndOptions(UpperQueueDownEnd* queue_end, ChannelConfigurationOptions options)

        : enqueue_buffer_(queue_end), options_(std::move(options)) {}

    os::EnqueueBuffer<UpperEnqueue> enqueue_buffer_;

    ChannelConfigurationOptions options_;

  };



  LowerQueueUpEnd* link_queue_up_end_;

  os::Handler* handler_;

  std::unordered_map<Cid, ChannelBufferAndOptions> channel_map_;



  void link_queue_dequeue_callback();

  void handle_basic_mode_packet(Cid cid, const BasicFrameView& view);

  void handle_enhanced_retransmission_mode_packet(Cid cid, BasicFrameView view);

};



}  // namespace internal

}  // namespace l2cap

}  // namespace bluetooth