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 #pragma once
18 
19 #include <memory>
20 #include <unordered_map>
21 
22 #include "hci/acl_manager/classic_acl_connection.h"
23 #include "l2cap/classic/dynamic_channel_configuration_option.h"
24 #include "l2cap/classic/internal/dynamic_channel_service_manager_impl.h"
25 #include "l2cap/classic/internal/fixed_channel_impl.h"
26 #include "l2cap/classic/internal/fixed_channel_service_manager_impl.h"
27 #include "l2cap/classic/security_enforcement_interface.h"
28 #include "l2cap/internal/data_pipeline_manager.h"
29 #include "l2cap/internal/dynamic_channel_allocator.h"
30 #include "l2cap/internal/dynamic_channel_impl.h"
31 #include "l2cap/internal/fixed_channel_allocator.h"
32 #include "l2cap/internal/ilink.h"
33 #include "l2cap/internal/parameter_provider.h"
34 #include "os/alarm.h"
35 #include "os/handler.h"
36 #include "signalling_manager.h"
37 
38 namespace bluetooth {
39 namespace l2cap {
40 namespace classic {
41 namespace internal {
42 
43 class LinkManager;
44 
45 class Link : public l2cap::internal::ILink, public hci::acl_manager::ConnectionManagementCallbacks {
46  public:
47   Link(os::Handler* l2cap_handler, std::unique_ptr<hci::acl_manager::ClassicAclConnection> acl_connection,
48        l2cap::internal::ParameterProvider* parameter_provider,
49        DynamicChannelServiceManagerImpl* dynamic_service_manager, FixedChannelServiceManagerImpl* fixed_service_manager,
50        LinkManager* link_manager);
51 
GetDevice()52   hci::AddressWithType GetDevice() const override {
53     return {acl_connection_->GetAddress(), hci::AddressType::PUBLIC_DEVICE_ADDRESS};
54   }
55 
56   struct PendingDynamicChannelConnection {
57     os::Handler* handler_;
58     DynamicChannelManager::OnConnectionOpenCallback on_open_callback_;
59     DynamicChannelManager::OnConnectionFailureCallback on_fail_callback_;
60     classic::DynamicChannelConfigurationOption configuration_;
61   };
62 
63   struct PendingAuthenticateDynamicChannelConnection {
64     Psm psm_;
65     Cid cid_;
66     PendingDynamicChannelConnection pending_dynamic_channel_connection_;
67   };
68 
69   // ACL methods
70 
71   virtual void OnAclDisconnected(hci::ErrorCode status);
72 
73   virtual void Disconnect();
74 
75   virtual void Encrypt();
76 
77   virtual void Authenticate();
78 
79   virtual bool IsAuthenticated() const;
80 
81   virtual void ReadRemoteVersionInformation();
82 
83   virtual void ReadRemoteSupportedFeatures();
84 
85   virtual void ReadRemoteExtendedFeatures();
86 
87   virtual void ReadClockOffset();
88 
89   // Increase the link usage refcount to ensure the link won't be disconnected when SecurityModule needs it
90   virtual void AcquireSecurityHold();
91 
92   // Decrease the link usage refcount when SecurityModule no longer needs it
93   virtual void ReleaseSecurityHold();
94 
95   // FixedChannel methods
96 
97   std::shared_ptr<FixedChannelImpl> AllocateFixedChannel(Cid cid);
98 
99   virtual bool IsFixedChannelAllocated(Cid cid);
100 
101   // DynamicChannel methods
102 
103   virtual Cid ReserveDynamicChannel();
104 
105   virtual void SendConnectionRequest(Psm psm, Cid local_cid);
106   virtual void SendConnectionRequest(Psm psm, Cid local_cid,
107                                      PendingDynamicChannelConnection pending_dynamic_channel_connection);
108 
109   // When a Link is established, LinkManager notifies pending dynamic channels to connect
110   virtual void SetPendingDynamicChannels(std::list<Psm> psm_list,
111                                          std::list<Link::PendingDynamicChannelConnection> callback_list);
112 
113   // Invoked by signalling manager to indicate an outgoing connection request failed and link shall free resources
114   virtual void OnOutgoingConnectionRequestFail(Cid local_cid, DynamicChannelManager::ConnectionResult result);
115 
116   virtual void SendInitialConfigRequestOrQueue(Cid local_cid);
117 
118   virtual void SendInformationRequest(InformationRequestInfoType type);
119 
120   virtual void SendDisconnectionRequest(Cid local_cid, Cid remote_cid) override;
121 
122   virtual std::shared_ptr<l2cap::internal::DynamicChannelImpl> AllocateDynamicChannel(Psm psm, Cid remote_cid);
123 
124   virtual std::shared_ptr<l2cap::internal::DynamicChannelImpl> AllocateReservedDynamicChannel(Cid reserved_cid, Psm psm,
125                                                                                               Cid remote_cid);
126 
127   virtual classic::DynamicChannelConfigurationOption GetConfigurationForInitialConfiguration(Cid cid);
128 
129   virtual void FreeDynamicChannel(Cid cid);
130 
131   // Check how many channels are acquired or in use, if zero, start tear down timer, if non-zero, cancel tear down timer
132   virtual void RefreshRefCount();
133 
134   virtual void NotifyChannelCreation(Cid cid, std::unique_ptr<DynamicChannel> channel);
135   virtual void NotifyChannelFail(Cid cid, DynamicChannelManager::ConnectionResult result);
136 
137   // Information received from signaling channel
138   virtual void SetRemoteConnectionlessMtu(Mtu mtu);
139   virtual Mtu GetRemoteConnectionlessMtu() const;
140   virtual bool GetRemoteSupportsErtm() const;
141   virtual bool GetRemoteSupportsFcs() const;
142   virtual void OnRemoteExtendedFeatureReceived(bool ertm_supported, bool fcs_supported);
143 
ToString()144   virtual std::string ToString() const {
145     return GetDevice().ToString();
146   }
147 
SendLeCredit(Cid local_cid,uint16_t credit)148   void SendLeCredit(Cid local_cid, uint16_t credit) override {}
149 
150   void AddChannelPendingingAuthentication(PendingAuthenticateDynamicChannelConnection pending_channel);
151 
152   // ConnectionManagementCallbacks
153   void OnConnectionPacketTypeChanged(uint16_t packet_type) override;
154   void OnAuthenticationComplete() override;
155   void OnEncryptionChange(hci::EncryptionEnabled enabled) override;
156   void OnChangeConnectionLinkKeyComplete() override;
157   void OnReadClockOffsetComplete(uint16_t clock_offset) override;
158   void OnModeChange(hci::Mode current_mode, uint16_t interval) override;
159   void OnQosSetupComplete(hci::ServiceType service_type, uint32_t token_rate, uint32_t peak_bandwidth, uint32_t latency,
160                           uint32_t delay_variation) override;
161   void OnFlowSpecificationComplete(hci::FlowDirection flow_direction, hci::ServiceType service_type,
162                                    uint32_t token_rate, uint32_t token_bucket_size, uint32_t peak_bandwidth,
163                                    uint32_t access_latency) override;
164   void OnFlushOccurred() override;
165   void OnRoleDiscoveryComplete(hci::Role current_role) override;
166   void OnReadLinkPolicySettingsComplete(uint16_t link_policy_settings) override;
167   void OnReadAutomaticFlushTimeoutComplete(uint16_t flush_timeout) override;
168   void OnReadTransmitPowerLevelComplete(uint8_t transmit_power_level) override;
169   void OnReadLinkSupervisionTimeoutComplete(uint16_t link_supervision_timeout) override;
170   void OnReadFailedContactCounterComplete(uint16_t failed_contact_counter) override;
171   void OnReadLinkQualityComplete(uint8_t link_quality) override;
172   void OnReadAfhChannelMapComplete(hci::AfhMode afh_mode, std::array<uint8_t, 10> afh_channel_map) override;
173   void OnReadRssiComplete(uint8_t rssi) override;
174   void OnReadClockComplete(uint32_t clock, uint16_t accuracy) override;
175   void OnMasterLinkKeyComplete(hci::KeyFlag key_flag) override;
176   void OnRoleChange(hci::Role new_role) override;
177   void OnDisconnection(hci::ErrorCode reason) override;
178 
179  private:
180   void connect_to_pending_dynamic_channels();
181   void send_pending_configuration_requests();
182 
183   os::Handler* l2cap_handler_;
184   l2cap::internal::FixedChannelAllocator<FixedChannelImpl, Link> fixed_channel_allocator_{this, l2cap_handler_};
185   l2cap::internal::DynamicChannelAllocator dynamic_channel_allocator_{this, l2cap_handler_};
186   std::unique_ptr<hci::acl_manager::ClassicAclConnection> acl_connection_;
187   l2cap::internal::DataPipelineManager data_pipeline_manager_;
188   l2cap::internal::ParameterProvider* parameter_provider_;
189   DynamicChannelServiceManagerImpl* dynamic_service_manager_;
190   FixedChannelServiceManagerImpl* fixed_service_manager_;
191   LinkManager* link_manager_;
192   std::unordered_map<Cid, PendingDynamicChannelConnection> local_cid_to_pending_dynamic_channel_connection_map_;
193   os::Alarm link_idle_disconnect_alarm_{l2cap_handler_};
194   ClassicSignallingManager signalling_manager_;
195   Mtu remote_connectionless_mtu_ = kMinimumClassicMtu;
196   bool remote_extended_feature_received_ = false;
197   bool remote_supports_ertm_ = false;
198   bool remote_supports_fcs_ = false;
199   hci::EncryptionEnabled encryption_enabled_ = hci::EncryptionEnabled::OFF;
200   std::list<Link::PendingAuthenticateDynamicChannelConnection> pending_channel_list_;
201   std::list<Psm> pending_dynamic_psm_list_;
202   std::list<Link::PendingDynamicChannelConnection> pending_dynamic_channel_callback_list_;
203   std::list<uint16_t> pending_outgoing_configuration_request_list_;
204   bool used_by_security_module_ = false;
205   bool has_requested_authentication_ = false;
206   DISALLOW_COPY_AND_ASSIGN(Link);
207 };
208 
209 }  // namespace internal
210 }  // namespace classic
211 }  // namespace l2cap
212 }  // namespace bluetooth
213