1 /*
2  * Copyright (C) 2016 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 <set>
20 
21 #include <android/hidl/manager/1.2/IServiceManager.h>
22 #include <hidl/Status.h>
23 #include <hidl/MQDescriptor.h>
24 
25 namespace android {
26 namespace hidl {
27 namespace manager {
28 namespace implementation {
29 
30 using ::android::hardware::hidl_vec;
31 using ::android::hardware::hidl_string;
32 using ::android::hardware::Return;
33 using ::android::hardware::Void;
34 using ::android::hidl::base::V1_0::IBase;
35 using ::android::hidl::manager::V1_0::IServiceNotification;
36 using ::android::hidl::manager::V1_1::IServiceManager;
37 using ::android::hidl::manager::V1_2::IClientCallback;
38 using ::android::sp;
39 
40 struct HidlService {
41     HidlService(const std::string &interfaceName,
42                 const std::string &instanceName,
43                 const sp<IBase> &service,
44                 const pid_t pid);
45     HidlService(const std::string &interfaceName,
46                 const std::string &instanceName)
47     : HidlService(
48         interfaceName,
49         instanceName,
50         nullptr,
51         static_cast<pid_t>(IServiceManager::PidConstant::NO_PID))
52     {}
53     virtual ~HidlService() {}
54 
55     /**
56      * Note, getService() can be nullptr. This is because you can have a HidlService
57      * with registered IServiceNotification objects but no service registered yet.
58      */
59     sp<IBase> getService() const;
60     void setService(sp<IBase> service, pid_t pid);
61     pid_t getDebugPid() const;
62     const std::string &getInterfaceName() const;
63     const std::string &getInstanceName() const;
64 
65     void addListener(const sp<IServiceNotification> &listener);
66     bool removeListener(const wp<IBase> &listener);
67     void registerPassthroughClient(pid_t pid);
68 
69     // also sends onClients(true) if we have clients
70     // knownClientCount, see forceHandleClientCallbacks
71     void addClientCallback(const sp<IClientCallback>& callback, size_t knownClientCount);
72     bool removeClientCallback(const sp<IClientCallback>& callback);
73 
74     // return is if we are guaranteed to have a client
75     // knownClientCount, see forceHandleClientCallbacks
76     bool handleClientCallbacks(bool isCalledOnInterval, size_t knownClientCount);
77 
78     // Updates client callbacks (even if mClientCallbacks is emtpy)
79     // see handleClientCallbacks
80     //
81     // knownClientCount - this is the number of clients that is currently
82     // expected to be in use by known actors. This number of clients must be
83     // exceeded in order to consider the service to have clients.
84     //
85     // returns whether or not this service has clients
86     bool forceHandleClientCallbacks(bool isCalledOnInterval, size_t knownClientCount);
87 
88     // when giving out a handle to a client, but the kernel might not know this yet
89     void guaranteeClient();
90 
91     std::string string() const; // e.x. "android.hidl.manager@1.0::IServiceManager/manager"
92     const std::set<pid_t> &getPassthroughClients() const;
93 
94 protected:
95     // mockable number of clients including hwservicemanager. -1 if not implemented or unavailable.
96     virtual ssize_t getNodeStrongRefCount();
97 
98 private:
99     void sendRegistrationNotifications();
100 
101     // Also updates mHasClients (of what the last callback was)
102     void sendClientCallbackNotifications(bool hasClients);
103 
104     // Only sends notification
105     void sendClientCallbackNotification(const sp<IClientCallback>& callback, bool hasClients);
106 
107     const std::string                     mInterfaceName; // e.x. "android.hidl.manager@1.0::IServiceManager"
108     const std::string                     mInstanceName;  // e.x. "manager"
109     sp<IBase>                             mService;
110 
111     std::vector<sp<IServiceNotification>> mListeners{};
112     std::set<pid_t>                       mPassthroughClients{};
113     pid_t                                 mPid = static_cast<pid_t>(IServiceManager::PidConstant::NO_PID);
114 
115     std::vector<sp<IClientCallback>>      mClientCallbacks{};
116     bool                                  mHasClients = false; // notifications sent on true -> false.
117     bool                                  mGuaranteeClient = false; // whenever a client is handed out
118     size_t                                mNoClientsCounter = 0;
119 };
120 
121 }  // namespace implementation
122 }  // namespace manager
123 }  // namespace hidl
124 }  // namespace android
125