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 #include <android-base/logging.h>
18 #include <binder/IPCThreadState.h>
19 #include <binder/ProcessState.h>
20 #include <binder/Status.h>
21 #include <sys/timerfd.h>
22 #include <utils/Looper.h>
23 #include <utils/StrongPointer.h>
24 
25 #include "Access.h"
26 #include "ServiceManager.h"
27 
28 using ::android::Access;
29 using ::android::sp;
30 using ::android::Looper;
31 using ::android::LooperCallback;
32 using ::android::ProcessState;
33 using ::android::IPCThreadState;
34 using ::android::ProcessState;
35 using ::android::ServiceManager;
36 using ::android::os::IServiceManager;
37 using ::android::sp;
38 
39 class BinderCallback : public LooperCallback {
40 public:
setupTo(const sp<Looper> & looper)41     static sp<BinderCallback> setupTo(const sp<Looper>& looper) {
42         sp<BinderCallback> cb = new BinderCallback;
43 
44         int binder_fd = -1;
45         IPCThreadState::self()->setupPolling(&binder_fd);
46         LOG_ALWAYS_FATAL_IF(binder_fd < 0, "Failed to setupPolling: %d", binder_fd);
47 
48         // Flush after setupPolling(), to make sure the binder driver
49         // knows about this thread handling commands.
50         IPCThreadState::self()->flushCommands();
51 
52         int ret = looper->addFd(binder_fd,
53                                 Looper::POLL_CALLBACK,
54                                 Looper::EVENT_INPUT,
55                                 cb,
56                                 nullptr /*data*/);
57         LOG_ALWAYS_FATAL_IF(ret != 1, "Failed to add binder FD to Looper");
58 
59         return cb;
60     }
61 
handleEvent(int,int,void *)62     int handleEvent(int /* fd */, int /* events */, void* /* data */) override {
63         IPCThreadState::self()->handlePolledCommands();
64         return 1;  // Continue receiving callbacks.
65     }
66 };
67 
68 // LooperCallback for IClientCallback
69 class ClientCallbackCallback : public LooperCallback {
70 public:
setupTo(const sp<Looper> & looper,const sp<ServiceManager> & manager)71     static sp<ClientCallbackCallback> setupTo(const sp<Looper>& looper, const sp<ServiceManager>& manager) {
72         sp<ClientCallbackCallback> cb = new ClientCallbackCallback(manager);
73 
74         int fdTimer = timerfd_create(CLOCK_MONOTONIC, 0 /*flags*/);
75         LOG_ALWAYS_FATAL_IF(fdTimer < 0, "Failed to timerfd_create: fd: %d err: %d", fdTimer, errno);
76 
77         itimerspec timespec {
78             .it_interval = {
79                 .tv_sec = 5,
80                 .tv_nsec = 0,
81             },
82             .it_value = {
83                 .tv_sec = 5,
84                 .tv_nsec = 0,
85             },
86         };
87 
88         int timeRes = timerfd_settime(fdTimer, 0 /*flags*/, &timespec, nullptr);
89         LOG_ALWAYS_FATAL_IF(timeRes < 0, "Failed to timerfd_settime: res: %d err: %d", timeRes, errno);
90 
91         int addRes = looper->addFd(fdTimer,
92                                    Looper::POLL_CALLBACK,
93                                    Looper::EVENT_INPUT,
94                                    cb,
95                                    nullptr);
96         LOG_ALWAYS_FATAL_IF(addRes != 1, "Failed to add client callback FD to Looper");
97 
98         return cb;
99     }
100 
handleEvent(int fd,int,void *)101     int handleEvent(int fd, int /*events*/, void* /*data*/) override {
102         uint64_t expirations;
103         int ret = read(fd, &expirations, sizeof(expirations));
104         if (ret != sizeof(expirations)) {
105             ALOGE("Read failed to callback FD: ret: %d err: %d", ret, errno);
106         }
107 
108         mManager->handleClientCallbacks();
109         return 1;  // Continue receiving callbacks.
110     }
111 private:
ClientCallbackCallback(const sp<ServiceManager> & manager)112     ClientCallbackCallback(const sp<ServiceManager>& manager) : mManager(manager) {}
113     sp<ServiceManager> mManager;
114 };
115 
main(int argc,char ** argv)116 int main(int argc, char** argv) {
117     if (argc > 2) {
118         LOG(FATAL) << "usage: " << argv[0] << " [binder driver]";
119     }
120 
121     const char* driver = argc == 2 ? argv[1] : "/dev/binder";
122 
123     sp<ProcessState> ps = ProcessState::initWithDriver(driver);
124     ps->setThreadPoolMaxThreadCount(0);
125     ps->setCallRestriction(ProcessState::CallRestriction::FATAL_IF_NOT_ONEWAY);
126 
127     sp<ServiceManager> manager = new ServiceManager(std::make_unique<Access>());
128     if (!manager->addService("manager", manager, false /*allowIsolated*/, IServiceManager::DUMP_FLAG_PRIORITY_DEFAULT).isOk()) {
129         LOG(ERROR) << "Could not self register servicemanager";
130     }
131 
132     IPCThreadState::self()->setTheContextObject(manager);
133     ps->becomeContextManager(nullptr, nullptr);
134 
135     sp<Looper> looper = Looper::prepare(false /*allowNonCallbacks*/);
136 
137     BinderCallback::setupTo(looper);
138     ClientCallbackCallback::setupTo(looper, manager);
139 
140     while(true) {
141         looper->pollAll(-1);
142     }
143 
144     // should not be reached
145     return EXIT_FAILURE;
146 }
147