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::ConnectionInfo;
28 using os::IClientCallback;
29 using os::IServiceCallback;
30 using os::ServiceDebugInfo;
31 
32 class ServiceManager : public os::BnServiceManager, public IBinder::DeathRecipient {
33 public:
34     ServiceManager(std::unique_ptr<Access>&& access);
35     ~ServiceManager();
36 
37     // getService will try to start any services it cannot find
38     binder::Status getService(const std::string& name, sp<IBinder>* outBinder) override;
39     binder::Status checkService(const std::string& name, sp<IBinder>* outBinder) override;
40     binder::Status addService(const std::string& name, const sp<IBinder>& binder,
41                               bool allowIsolated, int32_t dumpPriority) override;
42     binder::Status listServices(int32_t dumpPriority, std::vector<std::string>* outList) override;
43     binder::Status registerForNotifications(const std::string& name,
44                                             const sp<IServiceCallback>& callback) override;
45     binder::Status unregisterForNotifications(const std::string& name,
46                                               const sp<IServiceCallback>& callback) override;
47 
48     binder::Status isDeclared(const std::string& name, bool* outReturn) override;
49     binder::Status getDeclaredInstances(const std::string& interface, std::vector<std::string>* outReturn) override;
50     binder::Status updatableViaApex(const std::string& name,
51                                     std::optional<std::string>* outReturn) override;
52     binder::Status getUpdatableNames(const std::string& apexName,
53                                      std::vector<std::string>* outReturn) override;
54     binder::Status getConnectionInfo(const std::string& name,
55                                      std::optional<ConnectionInfo>* outReturn) override;
56     binder::Status registerClientCallback(const std::string& name, const sp<IBinder>& service,
57                                           const sp<IClientCallback>& cb) override;
58     binder::Status tryUnregisterService(const std::string& name, const sp<IBinder>& binder) override;
59     binder::Status getServiceDebugInfo(std::vector<ServiceDebugInfo>* outReturn) override;
60     void binderDied(const wp<IBinder>& who) override;
61     void handleClientCallbacks();
62 
63     /**
64      *  This API is added for debug purposes. It clears members which hold service and callback
65      * information.
66      */
67     void clear();
68 
69 protected:
70     virtual void tryStartService(const Access::CallingContext& ctx, const std::string& name);
71 
72 private:
73     struct Service {
74         sp<IBinder> binder; // not null
75         bool allowIsolated;
76         int32_t dumpPriority;
77         bool hasClients = false; // notifications sent on true -> false.
78         bool guaranteeClient = false; // forces the client check to true
79         Access::CallingContext ctx;   // process that originally registers this
80 
81         // the number of clients of the service, including servicemanager itself
82         ssize_t getNodeStrongRefCount();
83 
84         ~Service();
85     };
86 
87     using ServiceCallbackMap = std::map<std::string, std::vector<sp<IServiceCallback>>>;
88     using ClientCallbackMap = std::map<std::string, std::vector<sp<IClientCallback>>>;
89     using ServiceMap = std::map<std::string, Service>;
90 
91     // removes a callback from mNameToRegistrationCallback, removing it if the vector is empty
92     // this updates iterator to the next location
93     void removeRegistrationCallback(const wp<IBinder>& who,
94                         ServiceCallbackMap::iterator* it,
95                         bool* found);
96     // returns whether there are known clients in addition to the count provided
97     bool handleServiceClientCallback(size_t knownClients, const std::string& serviceName,
98                                      bool isCalledOnInterval);
99     // Also updates mHasClients (of what the last callback was)
100     void sendClientCallbackNotifications(const std::string& serviceName, bool hasClients,
101                                          const char* context);
102     // removes a callback from mNameToClientCallback, deleting the entry if the vector is empty
103     // this updates the iterator to the next location
104     void removeClientCallback(const wp<IBinder>& who, ClientCallbackMap::iterator* it);
105 
106     sp<IBinder> tryGetService(const std::string& name, bool startIfNotFound);
107 
108     ServiceMap mNameToService;
109     ServiceCallbackMap mNameToRegistrationCallback;
110     ClientCallbackMap mNameToClientCallback;
111 
112     std::unique_ptr<Access> mAccess;
113 };
114 
115 }  // namespace android
116