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 #include "EventReporter.h"
18 
19 using android::interface_cast;
20 using android::net::INetdUnsolicitedEventListener;
21 using android::net::metrics::INetdEventListener;
22 
getNetdEventListener()23 android::sp<INetdEventListener> EventReporter::getNetdEventListener() {
24     std::lock_guard lock(mEventMutex);
25     if (mNetdEventListener == nullptr) {
26         // Use checkService instead of getService because getService waits for 5 seconds for the
27         // service to become available. The DNS resolver inside netd is started much earlier in the
28         // boot sequence than the framework DNS listener, and we don't want to delay all DNS lookups
29         // for 5 seconds until the DNS listener starts up.
30         android::sp<android::IBinder> b = android::defaultServiceManager()->checkService(
31                 android::String16("netd_listener"));
32         mNetdEventListener = interface_cast<INetdEventListener>(b);
33     }
34     // If the netd listener service is dead, the binder call will just return an error, which should
35     // be fine because the only impact is that we can't log netd events. In any case, this should
36     // only happen if the system server is going down, which means it will shortly be taking us down
37     // with it.
38     return mNetdEventListener;
39 }
40 
getNetdUnsolicitedEventListenerMap() const41 EventReporter::UnsolListenerMap EventReporter::getNetdUnsolicitedEventListenerMap() const {
42     std::lock_guard lock(mUnsolicitedMutex);
43     return mUnsolListenerMap;
44 }
45 
registerUnsolEventListener(const android::sp<INetdUnsolicitedEventListener> & listener)46 void EventReporter::registerUnsolEventListener(
47         const android::sp<INetdUnsolicitedEventListener>& listener) {
48     std::lock_guard lock(mUnsolicitedMutex);
49 
50     // Create the death listener.
51     class DeathRecipient : public android::IBinder::DeathRecipient {
52       public:
53         DeathRecipient(EventReporter* eventReporter,
54                        android::sp<INetdUnsolicitedEventListener> listener)
55             : mEventReporter(eventReporter), mListener(std::move(listener)) {}
56         ~DeathRecipient() override = default;
57         void binderDied(const android::wp<android::IBinder>& /* who */) override {
58             mEventReporter->unregisterUnsolEventListener(mListener);
59         }
60 
61       private:
62         EventReporter* mEventReporter;
63         android::sp<INetdUnsolicitedEventListener> mListener;
64     };
65     android::sp<android::IBinder::DeathRecipient> deathRecipient =
66             new DeathRecipient(this, listener);
67 
68     android::IInterface::asBinder(listener)->linkToDeath(deathRecipient);
69 
70     // TODO: Consider to use remote binder address as registering key
71     mUnsolListenerMap.insert({listener, deathRecipient});
72 }
73 
unregisterUnsolEventListener(const android::sp<INetdUnsolicitedEventListener> & listener)74 void EventReporter::unregisterUnsolEventListener(
75         const android::sp<INetdUnsolicitedEventListener>& listener) {
76     std::lock_guard lock(mUnsolicitedMutex);
77     mUnsolListenerMap.erase(listener);
78 }
79