1 /*
2  * Copyright (C) 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 <android/os/BnServiceManager.h>
20 #include <android/os/IClientCallback.h>
21 #include <android/os/IServiceCallback.h>
22 
23 #include "Access.h"
24 
25 namespace android {
26 
27 using os::IClientCallback;
28 using os::IServiceCallback;
29 
30 class ServiceManager : public os::BnServiceManager, public IBinder::DeathRecipient {
31 public:
32     ServiceManager(std::unique_ptr<Access>&& access);
33     ~ServiceManager();
34 
35     // getService will try to start any services it cannot find
36     binder::Status getService(const std::string& name, sp<IBinder>* outBinder) override;
37     binder::Status checkService(const std::string& name, sp<IBinder>* outBinder) override;
38     binder::Status addService(const std::string& name, const sp<IBinder>& binder,
39                               bool allowIsolated, int32_t dumpPriority) override;
40     binder::Status listServices(int32_t dumpPriority, std::vector<std::string>* outList) override;
41     binder::Status registerForNotifications(const std::string& name,
42                                             const sp<IServiceCallback>& callback) override;
43     binder::Status unregisterForNotifications(const std::string& name,
44                                               const sp<IServiceCallback>& callback) override;
45 
46     binder::Status isDeclared(const std::string& name, bool* outReturn) override;
47     binder::Status registerClientCallback(const std::string& name, const sp<IBinder>& service,
48                                           const sp<IClientCallback>& cb) override;
49     binder::Status tryUnregisterService(const std::string& name, const sp<IBinder>& binder) override;
50     void binderDied(const wp<IBinder>& who) override;
51     void handleClientCallbacks();
52 
53 protected:
54     virtual void tryStartService(const std::string& name);
55 
56 private:
57     struct Service {
58         sp<IBinder> binder; // not null
59         bool allowIsolated;
60         int32_t dumpPriority;
61         bool hasClients = false; // notifications sent on true -> false.
62         bool guaranteeClient = false; // forces the client check to true
63         pid_t debugPid = 0; // the process in which this service runs
64 
65         // the number of clients of the service, including servicemanager itself
66         ssize_t getNodeStrongRefCount();
67     };
68 
69     using ServiceCallbackMap = std::map<std::string, std::vector<sp<IServiceCallback>>>;
70     using ClientCallbackMap = std::map<std::string, std::vector<sp<IClientCallback>>>;
71     using ServiceMap = std::map<std::string, Service>;
72 
73     // removes a callback from mNameToRegistrationCallback, removing it if the vector is empty
74     // this updates iterator to the next location
75     void removeRegistrationCallback(const wp<IBinder>& who,
76                         ServiceCallbackMap::iterator* it,
77                         bool* found);
78     ssize_t handleServiceClientCallback(const std::string& serviceName, bool isCalledOnInterval);
79      // Also updates mHasClients (of what the last callback was)
80     void sendClientCallbackNotifications(const std::string& serviceName, bool hasClients);
81     // removes a callback from mNameToClientCallback, deleting the entry if the vector is empty
82     // this updates the iterator to the next location
83     void removeClientCallback(const wp<IBinder>& who, ClientCallbackMap::iterator* it);
84 
85     sp<IBinder> tryGetService(const std::string& name, bool startIfNotFound);
86 
87     ServiceMap mNameToService;
88     ServiceCallbackMap mNameToRegistrationCallback;
89     ClientCallbackMap mNameToClientCallback;
90 
91     std::unique_ptr<Access> mAccess;
92 };
93 
94 }  // namespace android
95