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 <atomic>
20 #include <memory>
21 #include <unordered_map>
22 
23 #include "hci/acl_manager/classic_acl_connection.h"
24 #include "l2cap/classic/dynamic_channel_configuration_option.h"
25 #include "l2cap/classic/internal/dynamic_channel_service_manager_impl.h"
26 #include "l2cap/classic/internal/fixed_channel_impl.h"
27 #include "l2cap/classic/internal/fixed_channel_service_manager_impl.h"
28 #include "l2cap/classic/security_enforcement_interface.h"
29 #include "l2cap/internal/data_pipeline_manager.h"
30 #include "l2cap/internal/dynamic_channel_allocator.h"
31 #include "l2cap/internal/dynamic_channel_impl.h"
32 #include "l2cap/internal/fixed_channel_allocator.h"
33 #include "l2cap/internal/ilink.h"
34 #include "l2cap/internal/parameter_provider.h"
35 #include "os/alarm.h"
36 #include "os/handler.h"
37 #include "signalling_manager.h"
38 
39 namespace bluetooth {
40 namespace l2cap {
41 namespace classic {
42 namespace internal {
43 
44 class LinkManager;
45 class DumpsysHelper;
46 
47 class Link : public l2cap::internal::ILink, public hci::acl_manager::ConnectionManagementCallbacks {
48  public:
49   Link(os::Handler* l2cap_handler, std::unique_ptr<hci::acl_manager::ClassicAclConnection> acl_connection,
50        l2cap::internal::ParameterProvider* parameter_provider,
51        DynamicChannelServiceManagerImpl* dynamic_service_manager, FixedChannelServiceManagerImpl* fixed_service_manager,
52        LinkManager* link_manager);
53 
GetDevice()54   hci::AddressWithType GetDevice() const override {
55     return {acl_connection_->GetAddress(), hci::AddressType::PUBLIC_DEVICE_ADDRESS};
56   }
57 
58   struct PendingDynamicChannelConnection {
59     os::Handler* handler_;
60     DynamicChannelManager::OnConnectionOpenCallback on_open_callback_;
61     DynamicChannelManager::OnConnectionFailureCallback on_fail_callback_;
62     classic::DynamicChannelConfigurationOption configuration_;
63   };
64 
65   struct PendingAuthenticateDynamicChannelConnection {
66     Psm psm_;
67     Cid cid_;
68     PendingDynamicChannelConnection pending_dynamic_channel_connection_;
69   };
70 
71   // ACL methods
72 
73   virtual void OnAclDisconnected(hci::ErrorCode status);
74 
75   virtual void Disconnect();
76 
77   virtual void Encrypt();
78 
79   virtual void Authenticate();
80 
81   virtual bool IsAuthenticated() const;
82 
83   virtual void ReadRemoteVersionInformation();
84 
85   virtual void ReadRemoteSupportedFeatures();
86 
87   virtual void ReadRemoteExtendedFeatures(uint8_t page_number);
88 
89   virtual void ReadClockOffset();
90 
91   // Increase the link usage refcount to ensure the link won't be disconnected when SecurityModule needs it
92   virtual void AcquireSecurityHold();
93 
94   // Decrease the link usage refcount when SecurityModule no longer needs it
95   virtual void ReleaseSecurityHold();
96 
97   // FixedChannel methods
98 
99   std::shared_ptr<FixedChannelImpl> AllocateFixedChannel(Cid cid);
100 
101   virtual bool IsFixedChannelAllocated(Cid cid);
102 
103   // DynamicChannel methods
104 
105   virtual Cid ReserveDynamicChannel();
106 
107   virtual void SendConnectionRequest(Psm psm, Cid local_cid);
108   virtual void SendConnectionRequest(Psm psm, Cid local_cid,
109                                      PendingDynamicChannelConnection pending_dynamic_channel_connection);
110   void SetChannelTxPriority(Cid local_cid, bool high_priority) override;
111 
112   // When a Link is established, LinkManager notifies pending dynamic channels to connect
113   virtual void SetPendingDynamicChannels(std::list<Psm> psm_list,
114                                          std::list<Link::PendingDynamicChannelConnection> callback_list);
115 
116   // Invoked by signalling manager to indicate an outgoing connection request failed and link shall free resources
117   virtual void OnOutgoingConnectionRequestFail(Cid local_cid, DynamicChannelManager::ConnectionResult result);
118 
119   virtual void SendInitialConfigRequestOrQueue(Cid local_cid);
120 
121   virtual void SendInformationRequest(InformationRequestInfoType type);
122 
123   virtual void SendDisconnectionRequest(Cid local_cid, Cid remote_cid) override;
124 
125   virtual std::shared_ptr<l2cap::internal::DynamicChannelImpl> AllocateDynamicChannel(Psm psm, Cid remote_cid);
126 
127   virtual std::shared_ptr<l2cap::internal::DynamicChannelImpl> AllocateReservedDynamicChannel(Cid reserved_cid, Psm psm,
128                                                                                               Cid remote_cid);
129 
130   virtual classic::DynamicChannelConfigurationOption GetConfigurationForInitialConfiguration(Cid cid);
131 
132   virtual void FreeDynamicChannel(Cid cid);
133 
134   // Check how many channels are acquired or in use, if zero, start tear down timer, if non-zero, cancel tear down timer
135   virtual void RefreshRefCount();
136 
137   virtual void NotifyChannelCreation(Cid cid, std::unique_ptr<DynamicChannel> channel);
138   virtual void NotifyChannelFail(Cid cid, DynamicChannelManager::ConnectionResult result);
139 
140   // Information received from signaling channel
141   virtual void SetRemoteConnectionlessMtu(Mtu mtu);
142   virtual Mtu GetRemoteConnectionlessMtu() const;
143   virtual bool GetRemoteSupportsErtm() const;
144   virtual bool GetRemoteSupportsFcs() const;
145   virtual void OnRemoteExtendedFeatureReceived(bool ertm_supported, bool fcs_supported);
146 
ToString()147   virtual std::string ToString() const {
148     return GetDevice().ToString();
149   }
150 
SendLeCredit(Cid local_cid,uint16_t credit)151   void SendLeCredit(Cid local_cid, uint16_t credit) override {}
152 
153   // ConnectionManagementCallbacks
154   void OnConnectionPacketTypeChanged(uint16_t packet_type) override;
155   void OnAuthenticationComplete(hci::ErrorCode hci_status) override;
156   void OnEncryptionChange(hci::EncryptionEnabled enabled) override;
157   void OnChangeConnectionLinkKeyComplete() override;
158   void OnReadClockOffsetComplete(uint16_t clock_offset) override;
159   void OnModeChange(hci::ErrorCode status, hci::Mode current_mode, uint16_t interval) override;
160   void OnSniffSubrating(
161       hci::ErrorCode hci_status,
162       uint16_t maximum_transmit_latency,
163       uint16_t maximum_receive_latency,
164       uint16_t minimum_remote_timeout,
165       uint16_t minimum_local_timeout) override;
166   void OnQosSetupComplete(hci::ServiceType service_type, uint32_t token_rate, uint32_t peak_bandwidth, uint32_t latency,
167                           uint32_t delay_variation) override;
168   void OnFlowSpecificationComplete(hci::FlowDirection flow_direction, hci::ServiceType service_type,
169                                    uint32_t token_rate, uint32_t token_bucket_size, uint32_t peak_bandwidth,
170                                    uint32_t access_latency) override;
171   void OnFlushOccurred() override;
172   void OnRoleDiscoveryComplete(hci::Role current_role) override;
173   void OnReadLinkPolicySettingsComplete(uint16_t link_policy_settings) override;
174   void OnReadAutomaticFlushTimeoutComplete(uint16_t flush_timeout) override;
175   void OnReadTransmitPowerLevelComplete(uint8_t transmit_power_level) override;
176   void OnReadLinkSupervisionTimeoutComplete(uint16_t link_supervision_timeout) override;
177   void OnReadFailedContactCounterComplete(uint16_t failed_contact_counter) override;
178   void OnReadLinkQualityComplete(uint8_t link_quality) override;
179   void OnReadAfhChannelMapComplete(hci::AfhMode afh_mode, std::array<uint8_t, 10> afh_channel_map) override;
180   void OnReadRssiComplete(uint8_t rssi) override;
181   void OnReadClockComplete(uint32_t clock, uint16_t accuracy) override;
182   void OnCentralLinkKeyComplete(hci::KeyFlag key_flag) override;
183   void OnRoleChange(hci::ErrorCode hci_status, hci::Role new_role) override;
184   void OnDisconnection(hci::ErrorCode reason) override;
185   void OnReadRemoteVersionInformationComplete(
186       hci::ErrorCode hci_status, uint8_t lmp_version, uint16_t manufacturer_name, uint16_t sub_version);
187   void OnReadRemoteSupportedFeaturesComplete(uint64_t features);
188   void OnReadRemoteExtendedFeaturesComplete(uint8_t page_number, uint8_t max_page_number, uint64_t features);
189 
190   struct EncryptionChangeListener {
191     Cid cid;
192     Psm psm;
193   };
194   void AddEncryptionChangeListener(EncryptionChangeListener);
195 
GetAclHandle()196   uint16_t GetAclHandle() const {
197     return acl_handle_;
198   }
199 
GetRole()200   hci::Role GetRole() const {
201     return role_;
202   }
203 
204   void OnPendingPacketChange(Cid local_cid, bool has_packet) override;
205 
206  private:
207   friend class DumpsysHelper;
208   void connect_to_pending_dynamic_channels();
209   void send_pending_configuration_requests();
210 
211   os::Handler* l2cap_handler_;
212   l2cap::internal::FixedChannelAllocator<FixedChannelImpl, Link> fixed_channel_allocator_{this, l2cap_handler_};
213   l2cap::internal::DynamicChannelAllocator dynamic_channel_allocator_{this, l2cap_handler_};
214   std::unique_ptr<hci::acl_manager::ClassicAclConnection> acl_connection_;
215   l2cap::internal::DataPipelineManager data_pipeline_manager_;
216   l2cap::internal::ParameterProvider* parameter_provider_;
217   DynamicChannelServiceManagerImpl* dynamic_service_manager_;
218   FixedChannelServiceManagerImpl* fixed_service_manager_;
219   LinkManager* link_manager_;
220   std::unordered_map<Cid, PendingDynamicChannelConnection> local_cid_to_pending_dynamic_channel_connection_map_;
221   os::Alarm link_idle_disconnect_alarm_{l2cap_handler_};
222   ClassicSignallingManager signalling_manager_;
223   uint16_t acl_handle_;
224   Mtu remote_connectionless_mtu_ = kMinimumClassicMtu;
225   hci::Role role_ = hci::Role::CENTRAL;
226   bool remote_extended_feature_received_ = false;
227   bool remote_supports_ertm_ = false;
228   bool remote_supports_fcs_ = false;
229   hci::EncryptionEnabled encryption_enabled_ = hci::EncryptionEnabled::OFF;
230   std::list<Psm> pending_dynamic_psm_list_;
231   std::list<Link::PendingDynamicChannelConnection> pending_dynamic_channel_callback_list_;
232   std::list<uint16_t> pending_outgoing_configuration_request_list_;
233   bool used_by_security_module_ = false;
234   bool has_requested_authentication_ = false;
235   std::list<EncryptionChangeListener> encryption_change_listener_;
236   std::atomic_int remaining_packets_to_be_sent_ = 0;
237   DISALLOW_COPY_AND_ASSIGN(Link);
238 };
239 
240 }  // namespace internal
241 }  // namespace classic
242 }  // namespace l2cap
243 }  // namespace bluetooth
244