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 #pragma once
17 
18 #include <string>
19 
20 #include "hci/address_with_type.h"
21 #include "l2cap/cid.h"
22 #include "l2cap/le/fixed_channel.h"
23 #include "l2cap/le/fixed_channel_service.h"
24 #include "os/handler.h"
25 
26 namespace bluetooth {
27 namespace l2cap {
28 namespace le {
29 
30 class L2capLeModule;
31 
32 namespace internal {
33 class LinkManager;
34 class FixedChannelServiceManagerImpl;
35 }  // namespace internal
36 
37 class FixedChannelManager {
38  public:
39   enum class ConnectionResultCode {
40     SUCCESS = 0,
41     FAIL_NO_SERVICE_REGISTERED = 1,      // No service is registered
42     FAIL_ALL_SERVICES_HAVE_CHANNEL = 2,  // All registered services already have a channel
43     FAIL_HCI_ERROR = 3,                  // See hci_error
44   };
45 
46   struct ConnectionResult {
47     ConnectionResultCode connection_result_code = ConnectionResultCode::SUCCESS;
48     hci::ErrorCode hci_error = hci::ErrorCode::SUCCESS;
49   };
50   /**
51    * OnConnectionFailureCallback(ConnectionResult failure_reason);
52    */
53   using OnConnectionFailureCallback = common::OnceCallback<void(ConnectionResult)>;
54 
55   /**
56    * OnConnectionOpenCallback(FixedChannel channel);
57    */
58   using OnConnectionOpenCallback = common::Callback<void(std::unique_ptr<FixedChannel>)>;
59 
60   enum class RegistrationResult {
61     SUCCESS = 0,
62     FAIL_DUPLICATE_SERVICE = 1,  // Duplicate service registration for the same CID
63     FAIL_INVALID_SERVICE = 2,    // Invalid CID
64   };
65 
66   /**
67    * OnRegistrationFailureCallback(RegistrationResult result, FixedChannelService service);
68    */
69   using OnRegistrationCompleteCallback =
70       common::OnceCallback<void(RegistrationResult, std::unique_ptr<FixedChannelService>)>;
71 
72   /**
73    * Connect to ALL fixed channels on a remote device
74    *
75    * - This method is asynchronous
76    * - When false is returned, the connection fails immediately
77    * - When true is returned, method caller should wait for on_fail_callback or on_open_callback registered through
78    *   RegisterService() API.
79    * - If an ACL connection does not exist, this method will create an ACL connection. As a result, on_open_callback
80    *   supplied through RegisterService() will be triggered to provide the actual FixedChannel objects
81    * - If HCI connection failed, on_fail_callback will be triggered with FAIL_HCI_ERROR
82    * - If fixed channel on a remote device is already reported as connected via on_open_callback and has been acquired
83    *   via FixedChannel#Acquire() API, it won't be reported again
84    * - If no service is registered, on_fail_callback will be triggered with FAIL_NO_SERVICE_REGISTERED
85    * - If there is an ACL connection and channels for each service is allocated, on_fail_callback will be triggered with
86    *   FAIL_ALL_SERVICES_HAVE_CHANNEL
87    *
88    * NOTE:
89    * This call will initiate an effort to connect all fixed channel services on a remote device.
90    * Due to the connectionless nature of fixed channels, all fixed channels will be connected together.
91    * If a fixed channel service does not need a particular fixed channel. It should release the received
92    * channel immediately after receiving on_open_callback via FixedChannel#Release()
93    *
94    * A module calling ConnectServices() must have called RegisterService() before.
95    * The callback will come back from on_open_callback in the service that is registered
96    *
97    * @param address_with_type: Remote device with type to make this connection.
98    * @param address_type: Address type of remote device
99    * @param on_fail_callback: A callback to indicate connection failure along with a status code.
100    * @param handler: The handler context in which to execute the @callback parameters.
101    *
102    * Returns: true if connection was able to be initiated, false otherwise.
103    */
104   bool ConnectServices(hci::AddressWithType address_with_type, OnConnectionFailureCallback on_fail_callback,
105                        os::Handler* handler);
106 
107   /**
108    * Register a service to receive incoming connections bound to a specific channel.
109    *
110    * - This method is asynchronous.
111    * - When false is returned, the registration fails immediately.
112    * - When true is returned, method caller should wait for on_service_registered callback that contains a
113    *   FixedChannelService object. The registered service can be managed from that object.
114    * - If a CID is already registered or some other error happens, on_registration_complete will be triggered with a
115    *   non-SUCCESS value
116    * - After a service is registered, any LE ACL connection will create a FixedChannel object that is
117    *   delivered through on_open_callback
118    * - on_open_callback, will only be triggered after on_service_registered callback
119    *
120    * @param cid:  cid used to receive incoming connections
121    * @param on_registration_complete: A callback to indicate the service setup has completed. If the return status is
122    *        not SUCCESS, it means service is not registered due to reasons like CID already take
123    * @param on_open_callback: A callback to indicate success of a connection initiated from a remote device.
124    * @param handler: The handler context in which to execute the @callback parameter.
125    */
126   bool RegisterService(Cid cid, OnRegistrationCompleteCallback on_registration_complete,
127                        OnConnectionOpenCallback on_connection_open, os::Handler* handler);
128 
129   friend class L2capLeModule;
130 
131  private:
132   // The constructor is not to be used by user code
FixedChannelManager(internal::FixedChannelServiceManagerImpl * service_manager,internal::LinkManager * link_manager,os::Handler * l2cap_layer_handler)133   FixedChannelManager(internal::FixedChannelServiceManagerImpl* service_manager, internal::LinkManager* link_manager,
134                       os::Handler* l2cap_layer_handler)
135       : service_manager_(service_manager), link_manager_(link_manager), l2cap_layer_handler_(l2cap_layer_handler) {}
136   internal::FixedChannelServiceManagerImpl* service_manager_ = nullptr;
137   internal::LinkManager* link_manager_ = nullptr;
138   os::Handler* l2cap_layer_handler_ = nullptr;
139   DISALLOW_COPY_AND_ASSIGN(FixedChannelManager);
140 };
141 
142 }  // namespace le
143 }  // namespace l2cap
144 }  // namespace bluetooth
145