1 /**
2  * Copyright (c) 2020, 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 #ifndef WATCHDOG_SERVER_SRC_WATCHDOGPROCESSSERVICE_H_
18 #define WATCHDOG_SERVER_SRC_WATCHDOGPROCESSSERVICE_H_
19 
20 #include <android-base/result.h>
21 #include <android/automotive/watchdog/BnCarWatchdog.h>
22 #include <android/automotive/watchdog/PowerCycle.h>
23 #include <android/automotive/watchdog/UserState.h>
24 #include <binder/IBinder.h>
25 #include <binder/Status.h>
26 #include <cutils/multiuser.h>
27 #include <utils/Looper.h>
28 #include <utils/Mutex.h>
29 #include <utils/String16.h>
30 #include <utils/StrongPointer.h>
31 #include <utils/Vector.h>
32 
33 #include <unordered_map>
34 #include <unordered_set>
35 #include <vector>
36 
37 namespace android {
38 namespace automotive {
39 namespace watchdog {
40 
41 class WatchdogProcessService : public IBinder::DeathRecipient {
42 public:
43     explicit WatchdogProcessService(const android::sp<Looper>& handlerLooper);
44 
45     virtual android::base::Result<void> dump(int fd, const Vector<String16>& args);
46 
47     virtual binder::Status registerClient(const sp<ICarWatchdogClient>& client,
48                                           TimeoutLength timeout);
49     virtual binder::Status unregisterClient(const sp<ICarWatchdogClient>& client);
50     virtual binder::Status registerMediator(const sp<ICarWatchdogClient>& mediator);
51     virtual binder::Status unregisterMediator(const sp<ICarWatchdogClient>& mediator);
52     virtual binder::Status registerMonitor(const sp<ICarWatchdogMonitor>& monitor);
53     virtual binder::Status unregisterMonitor(const sp<ICarWatchdogMonitor>& monitor);
54     virtual binder::Status tellClientAlive(const sp<ICarWatchdogClient>& client, int32_t sessionId);
55     virtual binder::Status tellMediatorAlive(const sp<ICarWatchdogClient>& mediator,
56                                              const std::vector<int32_t>& clientsNotResponding,
57                                              int32_t sessionId);
58     virtual binder::Status tellDumpFinished(const android::sp<ICarWatchdogMonitor>& monitor,
59                                             int32_t pid);
60     virtual binder::Status notifyPowerCycleChange(PowerCycle cycle);
61     virtual binder::Status notifyUserStateChange(userid_t userId, UserState state);
62     virtual void binderDied(const android::wp<IBinder>& who);
63 
64     void doHealthCheck(int what);
65     void terminate();
66 
67 private:
68     enum ClientType {
69         Regular,
70         Mediator,
71     };
72 
73     struct ClientInfo {
ClientInfoClientInfo74         ClientInfo(const android::sp<ICarWatchdogClient>& client, pid_t pid, userid_t userId,
75                    ClientType type) :
76               client(client),
77               pid(pid),
78               userId(userId),
79               type(type) {}
80         std::string toString();
81 
82         android::sp<ICarWatchdogClient> client;
83         pid_t pid;
84         userid_t userId;
85         int sessionId;
86         ClientType type;
87     };
88 
89     typedef std::unordered_map<int, ClientInfo> PingedClientMap;
90 
91     class MessageHandlerImpl : public MessageHandler {
92     public:
93         explicit MessageHandlerImpl(const android::sp<WatchdogProcessService>& service);
94 
95         void handleMessage(const Message& message) override;
96 
97     private:
98         android::sp<WatchdogProcessService> mService;
99     };
100 
101 private:
102     binder::Status registerClientLocked(const android::sp<ICarWatchdogClient>& client,
103                                         TimeoutLength timeout, ClientType clientType);
104     binder::Status unregisterClientLocked(const std::vector<TimeoutLength>& timeouts,
105                                           android::sp<IBinder> binder, ClientType clientType);
106     bool isRegisteredLocked(const android::sp<ICarWatchdogClient>& client);
107     binder::Status tellClientAliveLocked(const android::sp<ICarWatchdogClient>& client,
108                                          int32_t sessionId);
109     base::Result<void> startHealthCheckingLocked(TimeoutLength timeout);
110     base::Result<void> dumpAndKillClientsIfNotResponding(TimeoutLength timeout);
111     base::Result<void> dumpAndKillAllProcesses(const std::vector<int32_t>& processesNotResponding);
112     int32_t getNewSessionId();
113     bool isWatchdogEnabled();
114 
115     using Processor =
116             std::function<void(std::vector<ClientInfo>&, std::vector<ClientInfo>::const_iterator)>;
117     bool findClientAndProcessLocked(const std::vector<TimeoutLength> timeouts,
118                                     const android::sp<IBinder> binder, const Processor& processor);
119 
120 private:
121     sp<Looper> mHandlerLooper;
122     android::sp<MessageHandlerImpl> mMessageHandler;
123     Mutex mMutex;
124     std::unordered_map<TimeoutLength, std::vector<ClientInfo>> mClients GUARDED_BY(mMutex);
125     std::unordered_map<TimeoutLength, PingedClientMap> mPingedClients GUARDED_BY(mMutex);
126     std::unordered_set<userid_t> mStoppedUserId GUARDED_BY(mMutex);
127     android::sp<ICarWatchdogMonitor> mMonitor GUARDED_BY(mMutex);
128     bool mWatchdogEnabled GUARDED_BY(mMutex);
129     // mLastSessionId is accessed only within main thread. No need for mutual-exclusion.
130     int32_t mLastSessionId;
131 };
132 
133 }  // namespace watchdog
134 }  // namespace automotive
135 }  // namespace android
136 
137 #endif  // WATCHDOG_SERVER_SRC_WATCHDOGPROCESSSERVICE_H_
138