1 /*
2  * Copyright 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "l2cap/internal/receiver.h"
18 
19 #include <bluetooth/log.h>
20 
21 #include "common/bidi_queue.h"
22 #include "l2cap/cid.h"
23 #include "l2cap/internal/data_pipeline_manager.h"
24 #include "l2cap/l2cap_packets.h"
25 #include "packet/packet_view.h"
26 
27 namespace bluetooth {
28 namespace l2cap {
29 namespace internal {
Receiver(LowerQueueUpEnd * link_queue_up_end,os::Handler * handler,DataPipelineManager * data_pipeline_manager_)30 Receiver::Receiver(
31     LowerQueueUpEnd* link_queue_up_end, os::Handler* handler, DataPipelineManager* data_pipeline_manager_)
32     : link_queue_up_end_(link_queue_up_end),
33       handler_(handler),
34       buffer_timer_(handler),
35       data_pipeline_manager_(data_pipeline_manager_) {
36   log::assert_that(
37       link_queue_up_end_ != nullptr && handler_ != nullptr,
38       "assert failed: link_queue_up_end_ != nullptr && handler_ != nullptr");
39   link_queue_up_end_->RegisterDequeue(handler_,
40                                       common::Bind(&Receiver::link_queue_dequeue_callback, common::Unretained(this)));
41 }
42 
43 // Invoked from external handler/thread (ModuleRegistry)
~Receiver()44 Receiver::~Receiver() {
45   link_queue_up_end_->UnregisterDequeue();
46 }
47 
48 // Invoked from external (Queue Reactable)
link_queue_dequeue_callback()49 void Receiver::link_queue_dequeue_callback() {
50   auto packet = link_queue_up_end_->TryDequeue();
51   auto basic_frame_view = BasicFrameView::Create(*packet);
52   if (!basic_frame_view.IsValid()) {
53     log::warn("Received an invalid basic frame");
54     return;
55   }
56   Cid cid = static_cast<Cid>(basic_frame_view.GetChannelId());
57   auto* data_controller = data_pipeline_manager_->GetDataController(cid);
58   if (data_controller == nullptr) {
59     // TODO(b/150170271): Buffer a few packets before data controller is attached
60     log::warn("Received a packet without data controller. cid: {}", cid);
61     buffered_packets_.emplace(*packet);
62     log::warn("Enqueued the unexpected packet. Current queue size: {}", buffered_packets_.size());
63     buffer_timer_.Schedule(
64         common::BindOnce(&Receiver::check_buffered_packets, common::Unretained(this)), std::chrono::milliseconds(500));
65 
66     return;
67   }
68   data_controller->OnPdu(*packet);
69 }
70 
check_buffered_packets()71 void Receiver::check_buffered_packets() {
72   while (!buffered_packets_.empty()) {
73     auto packet = buffered_packets_.front();
74     buffered_packets_.pop();
75     auto basic_frame_view = BasicFrameView::Create(packet);
76     if (!basic_frame_view.IsValid()) {
77       log::warn("Received an invalid basic frame");
78       return;
79     }
80     Cid cid = static_cast<Cid>(basic_frame_view.GetChannelId());
81     auto* data_controller = data_pipeline_manager_->GetDataController(cid);
82     if (data_controller == nullptr) {
83       log::error("Dropping a packet with invalid cid: {}", cid);
84     } else {
85       data_controller->OnPdu(packet);
86     }
87   }
88 }
89 
90 }  // namespace internal
91 }  // namespace l2cap
92 }  // namespace bluetooth
93