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 <chrono>
21 #include <memory>
22 
23 #include "common/interfaces/ILoggable.h"
24 #include "hci/acl_manager/le_acl_connection.h"
25 #include "l2cap/internal/data_pipeline_manager.h"
26 #include "l2cap/internal/dynamic_channel_allocator.h"
27 #include "l2cap/internal/fixed_channel_allocator.h"
28 #include "l2cap/internal/ilink.h"
29 #include "l2cap/internal/parameter_provider.h"
30 #include "l2cap/le/dynamic_channel_manager.h"
31 #include "l2cap/le/internal/dynamic_channel_service_manager_impl.h"
32 #include "l2cap/le/internal/fixed_channel_impl.h"
33 #include "l2cap/le/internal/fixed_channel_service_manager_impl.h"
34 #include "l2cap/le/internal/signalling_manager.h"
35 #include "l2cap/le/link_options.h"
36 #include "l2cap/le/security_enforcement_interface.h"
37 #include "os/alarm.h"
38 
39 namespace bluetooth {
40 namespace l2cap {
41 namespace le {
42 namespace internal {
43 
44 class LinkManager;
45 
46 class Link : public l2cap::internal::ILink,
47              public hci::acl_manager::LeConnectionManagementCallbacks,
48              public bluetooth::common::IRedactableLoggable {
49  public:
50   Link(os::Handler* l2cap_handler, std::unique_ptr<hci::acl_manager::LeAclConnection> acl_connection,
51        l2cap::internal::ParameterProvider* parameter_provider,
52        DynamicChannelServiceManagerImpl* dynamic_service_manager, FixedChannelServiceManagerImpl* fixed_service_manager,
53        LinkManager* link_manager);
54 
55   Link(const Link&) = delete;
56   Link& operator=(const Link&) = delete;
57 
58   ~Link() = default;
59 
GetDevice()60   inline hci::AddressWithType GetDevice() const override {
61     return acl_connection_->GetRemoteAddress();
62   }
63 
64   struct PendingDynamicChannelConnection {
65     os::Handler* handler_;
66     DynamicChannelManager::OnConnectionOpenCallback on_open_callback_;
67     DynamicChannelManager::OnConnectionFailureCallback on_fail_callback_;
68     le::DynamicChannelConfigurationOption configuration_;
69   };
70 
GetRole()71   inline virtual hci::Role GetRole() {
72     return acl_connection_->GetRole();
73   }
74 
GetAclConnection()75   inline virtual hci::acl_manager::LeAclConnection* GetAclConnection() {
76     return acl_connection_.get();
77   }
78 
79   // ACL methods
80 
81   virtual void OnAclDisconnected(hci::ErrorCode reason);
82 
83   void OnDisconnection(hci::ErrorCode reason) override;
84 
85   void OnConnectionUpdate(
86       hci::ErrorCode hci_status,
87       uint16_t connection_interval,
88       uint16_t connection_latency,
89       uint16_t supervision_timeout) override;
90 
91   void OnDataLengthChange(uint16_t tx_octets, uint16_t tx_time, uint16_t rx_octets, uint16_t rx_time) override;
92 
93   void OnReadRemoteVersionInformationComplete(
94       hci::ErrorCode hci_status, uint8_t lmp_version, uint16_t manufacturer_name, uint16_t sub_version) override;
95 
96   void OnLeReadRemoteFeaturesComplete(hci::ErrorCode hci_status, uint64_t features) override;
97 
98   void OnPhyUpdate(hci::ErrorCode hci_status, uint8_t tx_phy, uint8_t rx_phy) override;
99 
100   void OnLeSubrateChange(
101       hci::ErrorCode hci_status,
102       uint16_t subrate_factor,
103       uint16_t peripheral_latency,
104       uint16_t continuation_number,
105       uint16_t supervision_timeout) override;
106 
107   virtual void Disconnect();
108 
109   // Handles connection parameter update request from remote
110   virtual void UpdateConnectionParameterFromRemote(SignalId signal_id, uint16_t conn_interval_min,
111                                                    uint16_t conn_interval_max, uint16_t conn_latency,
112                                                    uint16_t supervision_timeout);
113   virtual bool CheckConnectionParameters(
114       uint16_t conn_interval_min, uint16_t conn_interval_max, uint16_t conn_latency, uint16_t supervision_timeout);
115 
116   virtual void SendConnectionParameterUpdate(uint16_t conn_interval_min, uint16_t conn_interval_max,
117                                              uint16_t conn_latency, uint16_t supervision_timeout,
118                                              uint16_t min_ce_length, uint16_t max_ce_length);
119 
120   // FixedChannel methods
121 
122   virtual std::shared_ptr<FixedChannelImpl> AllocateFixedChannel(Cid cid, SecurityPolicy security_policy);
123 
124   virtual bool IsFixedChannelAllocated(Cid cid);
125 
126   // DynamicChannel methods
127 
128   virtual Cid ReserveDynamicChannel();
129 
130   virtual void SendConnectionRequest(Psm psm, PendingDynamicChannelConnection pending_dynamic_channel_connection);
131 
132   void SendDisconnectionRequest(Cid local_cid, Cid remote_cid) override;
133 
134   // Invoked by signalling manager to indicate an outgoing connection request failed and link shall free resources
135   virtual void OnOutgoingConnectionRequestFail(Cid local_cid, LeCreditBasedConnectionResponseResult result);
136 
137   virtual std::shared_ptr<l2cap::internal::DynamicChannelImpl> AllocateDynamicChannel(Psm psm, Cid remote_cid);
138 
139   virtual std::shared_ptr<l2cap::internal::DynamicChannelImpl> AllocateReservedDynamicChannel(Cid reserved_cid, Psm psm,
140                                                                                               Cid remote_cid);
141 
142   virtual void FreeDynamicChannel(Cid cid);
143 
144   // Check how many channels are acquired or in use, if zero, start tear down timer, if non-zero, cancel tear down timer
145   virtual void RefreshRefCount();
146 
147   void NotifyChannelCreation(Cid cid, std::unique_ptr<DynamicChannel> user_channel);
148   void NotifyChannelFail(Cid cid, DynamicChannelManager::ConnectionResult result);
149 
ToString()150   virtual std::string ToString() {
151     return GetDevice().ToString();
152   }
153 
ToStringForLogging()154   std::string ToStringForLogging() const override {
155     return GetDevice().ToStringForLogging();
156   }
157 
ToRedactedStringForLogging()158   std::string ToRedactedStringForLogging() const override {
159     return GetDevice().ToRedactedStringForLogging();
160   }
161 
162   virtual uint16_t GetMps() const;
163 
164   virtual uint16_t GetInitialCredit() const;
165 
166   void SendLeCredit(Cid local_cid, uint16_t credit) override;
167 
GetLinkOptions()168   LinkOptions* GetLinkOptions() {
169     return &link_options_;
170   }
171 
172   void ReadRemoteVersionInformation();
173 
174   void OnPendingPacketChange(Cid local_cid, bool has_packet) override;
175 
176  private:
177   os::Handler* l2cap_handler_;
178   l2cap::internal::FixedChannelAllocator<FixedChannelImpl, Link> fixed_channel_allocator_{this, l2cap_handler_};
179   l2cap::internal::DynamicChannelAllocator dynamic_channel_allocator_{this, l2cap_handler_};
180   std::unique_ptr<hci::acl_manager::LeAclConnection> acl_connection_;
181   l2cap::internal::DataPipelineManager data_pipeline_manager_;
182   l2cap::internal::ParameterProvider* parameter_provider_;
183   DynamicChannelServiceManagerImpl* dynamic_service_manager_;
184   LeSignallingManager signalling_manager_;
185   std::unordered_map<Cid, PendingDynamicChannelConnection> local_cid_to_pending_dynamic_channel_connection_map_;
186   os::Alarm link_idle_disconnect_alarm_{l2cap_handler_};
187   LinkOptions link_options_{acl_connection_.get(), this, l2cap_handler_};
188   LinkManager* link_manager_;
189   SignalId update_request_signal_id_ = kInvalidSignalId;
190   uint16_t update_request_interval_min_;
191   uint16_t update_request_interval_max_;
192   uint16_t update_request_latency_;
193   uint16_t update_request_supervision_timeout_;
194   std::atomic_int remaining_packets_to_be_sent_ = 0;
195 
196   // Received connection update complete from ACL manager. SignalId is bound to a valid number when we need to send a
197   // response to remote. If SignalId is bound to an invalid number, we don't send a response to remote, because the
198   // connection update request is not from remote LL peripheral.
199   void on_connection_update_complete(SignalId signal_id, hci::ErrorCode error_code);
200 };
201 
202 }  // namespace internal
203 }  // namespace le
204 }  // namespace l2cap
205 }  // namespace bluetooth
206