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 #include "daemon/logging.h"
18 
19 #include <mutex>
20 #include <optional>
21 #include <string_view>
22 
23 #include <android-base/no_destructor.h>
24 #include <android-base/properties.h>
25 #include <android-base/strings.h>
26 #include <android-base/thread_annotations.h>
27 
28 #if defined(__ANDROID__)
29 struct LogStatus {
30     bool enabled[static_cast<size_t>(adb::LogType::COUNT)];
31 
32     bool& operator[](adb::LogType type) { return enabled[static_cast<size_t>(type)]; }
33 };
34 
35 using android::base::CachedProperty;
36 using android::base::NoDestructor;
37 
38 static NoDestructor<std::mutex> log_mutex;
39 static NoDestructor<CachedProperty> log_property GUARDED_BY(log_mutex)("debug.adbd.logging");
40 static std::optional<LogStatus> cached_log_status GUARDED_BY(log_mutex);
41 
42 static NoDestructor<CachedProperty> persist_log_property
43         GUARDED_BY(log_mutex)("persist.debug.adbd.logging");
44 static std::optional<LogStatus> cached_persist_log_status GUARDED_BY(log_mutex);
45 
46 static LogStatus ParseLogStatus(std::string_view str) {
47     LogStatus result = {};
48     for (const auto& part : android::base::Split(std::string(str), ",")) {
49         if (part == "cnxn") {
50             result[adb::LogType::Connection] = true;
51         } else if (part == "service") {
52             result[adb::LogType::Service] = true;
53         } else if (part == "shell") {
54             result[adb::LogType::Shell] = true;
55         } else if (part == "all") {
56             result[adb::LogType::Connection] = true;
57             result[adb::LogType::Service] = true;
58             result[adb::LogType::Shell] = true;
59         }
60     }
61     return result;
62 }
63 
64 static LogStatus GetLogStatus(android::base::CachedProperty* property,
65                               std::optional<LogStatus>* cached_status) REQUIRES(log_mutex) {
66     bool changed;
67     const char* value = property->Get(&changed);
68     if (changed || !*cached_status) {
69         **cached_status = ParseLogStatus(value);
70     }
71     return **cached_status;
72 }
73 
74 namespace adb {
75 bool is_logging_enabled(LogType type) {
76     std::lock_guard<std::mutex> lock(*log_mutex);
77     return GetLogStatus(log_property.get(), &cached_log_status)[type] ||
78            GetLogStatus(persist_log_property.get(), &cached_persist_log_status)[type];
79 }
80 }  // namespace adb
81 
82 #else
83 
84 namespace adb {
85 bool is_logging_enabled(LogType type) {
86     return false;
87 }
88 }  // namespace adb
89 #endif
90