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 <regex>
18 #include <thread>
19 
20 #include <android-base/strings.h>
21 #include <android-base/test_utils.h>
22 #include <gtest/gtest.h>
23 #include <netdutils/NetNativeTestBase.h>
24 
25 #include "DnsQueryLog.h"
26 #include "tests/resolv_test_utils.h"
27 
28 using namespace std::chrono_literals;
29 
30 namespace android::net {
31 
32 namespace {
33 
34 // Dump the log to STDOUT and capture it.
captureDumpOutput(const DnsQueryLog & queryLog)35 std::string captureDumpOutput(const DnsQueryLog& queryLog) {
36     netdutils::DumpWriter dw(STDOUT_FILENO);
37     CapturedStdout captured;
38     queryLog.dump(dw);
39     return captured.str();
40 }
41 
42 // A simple check for the dump result by checking the netIds one by one.
verifyDumpOutput(const std::string & dumpLog,const std::vector<int> & expectedNetIds)43 void verifyDumpOutput(const std::string& dumpLog, const std::vector<int>& expectedNetIds) {
44     // Capture three matches: netId, hostname, and answer (empty allowed).
45     static const std::regex pattern(
46             R"(netId=(\d+).* hostname=([\w\*]+) answer=\[([\w:,\.\*\s]*)\])");
47 
48     std::string str(dumpLog);
49     std::smatch sm;
50     for (const auto& netId : expectedNetIds) {
51         SCOPED_TRACE(netId);
52         EXPECT_TRUE(std::regex_search(str, sm, pattern));
53         EXPECT_EQ(sm[1], std::to_string(netId));
54         str = sm.suffix();
55     }
56 
57     // Ensure the dumpLog is exactly as expected.
58     EXPECT_FALSE(std::regex_search(str, sm, pattern));
59 }
60 
61 }  // namespace
62 
63 class DnsQueryLogTest : public NetNativeTestBase {
64   protected:
65     const std::vector<std::string> serversV4 = {"127.0.0.1", "1.2.3.4"};
66     const std::vector<std::string> serversV4V6 = {"127.0.0.1", "1.2.3.4", "2001:db8::1",
67                                                   "fe80:1::2%testnet"};
68 };
69 
TEST_F(DnsQueryLogTest,Push)70 TEST_F(DnsQueryLogTest, Push) {
71     std::vector<DnsQueryLog::Record> records = {
72             DnsQueryLog::Record(30, 1000, 1000, "example.com", serversV4, 10),
73             DnsQueryLog::Record(31, 1000, 1000, "", serversV4, 10),      // Empty hostname.
74             DnsQueryLog::Record(32, 1000, 1000, "example.com", {}, 10),  // No answer.
75             DnsQueryLog::Record(33, 1000, 1000, "example.com", serversV4V6, 10),
76     };
77     DnsQueryLog queryLog;
78     for (auto& r : records) {
79         queryLog.push(std::move(r));
80     }
81 
82     std::string output = captureDumpOutput(queryLog);
83     verifyDumpOutput(output, {30, 31, 32, 33});
84 }
85 
TEST_F(DnsQueryLogTest,PushStressTest)86 TEST_F(DnsQueryLogTest, PushStressTest) {
87     const int threadNum = 100;
88     const int pushNum = 1000;
89     const size_t size = 500;
90     DnsQueryLog queryLog(size);
91     std::vector<std::thread> threads(threadNum);
92 
93     // Launch 'threadNum' threads to push the same queryLog 'pushNum' times.
94     for (auto& thread : threads) {
95         thread = std::thread([&]() {
96             for (int i = 0; i < pushNum; i++) {
97                 DnsQueryLog::Record record(30, 1000, 1000, "www.example.com", serversV4, 10);
98                 queryLog.push(std::move(record));
99             }
100         });
101     }
102     for (auto& thread : threads) {
103         thread.join();
104     }
105 
106     // Verify there are exact 'size' records in queryLog.
107     std::string output = captureDumpOutput(queryLog);
108     verifyDumpOutput(output, std::vector(size, 30));
109 }
110 
TEST_F(DnsQueryLogTest,ZeroSize)111 TEST_F(DnsQueryLogTest, ZeroSize) {
112     const size_t size = 0;
113     DnsQueryLog::Record r1(30, 1000, 1000, "www.example1.com", serversV4V6, 10);
114     DnsQueryLog::Record r2(31, 1000, 1000, "www.example2.com", serversV4V6, 10);
115     DnsQueryLog::Record r3(32, 1000, 1000, "www.example3.com", serversV4V6, 10);
116 
117     DnsQueryLog queryLog(size);
118     queryLog.push(std::move(r1));
119     queryLog.push(std::move(r2));
120     queryLog.push(std::move(r3));
121 
122     std::string output = captureDumpOutput(queryLog);
123     verifyDumpOutput(output, {});
124 }
125 
TEST_F(DnsQueryLogTest,CapacityFull)126 TEST_F(DnsQueryLogTest, CapacityFull) {
127     const size_t size = 3;
128     DnsQueryLog::Record r1(30, 1000, 1000, "www.example1.com", serversV4V6, 10);
129     DnsQueryLog::Record r2(31, 1000, 1000, "www.example2.com", serversV4V6, 10);
130     DnsQueryLog::Record r3(32, 1000, 1000, "www.example3.com", serversV4V6, 10);
131     DnsQueryLog::Record r4(33, 1000, 1000, "www.example4.com", serversV4V6, 10);
132     const std::vector<int> expectedNetIds = {31, 32, 33};
133 
134     DnsQueryLog queryLog(size);
135     queryLog.push(std::move(r1));
136     queryLog.push(std::move(r2));
137     queryLog.push(std::move(r3));
138     queryLog.push(std::move(r4));
139 
140     std::string output = captureDumpOutput(queryLog);
141     verifyDumpOutput(output, expectedNetIds);
142 }
143 
TEST_F(DnsQueryLogTest,SizeCustomization)144 TEST_F(DnsQueryLogTest, SizeCustomization) {
145     const size_t logSize = 3;
146     const ScopedSystemProperties sp(kQueryLogSize, std::to_string(logSize));
147     DnsQueryLog queryLog;
148 
149     for (int i = 0; i < 200; i++) {
150         DnsQueryLog::Record record(30, 1000, 1000, "www.example.com", serversV4, 10);
151         queryLog.push(std::move(record));
152     }
153 
154     // Verify that there are exact customized number of records in queryLog.
155     const std::string output = captureDumpOutput(queryLog);
156     verifyDumpOutput(output, std::vector(logSize, 30));
157 }
158 
TEST_F(DnsQueryLogTest,InvalidSizeCustomization)159 TEST_F(DnsQueryLogTest, InvalidSizeCustomization) {
160     // The max log size defined in DnsQueryLog.h is 10000.
161     for (const auto& logSize : {"-1", "10001", "non-digit"}) {
162         const ScopedSystemProperties sp(kQueryLogSize, logSize);
163         DnsQueryLog queryLog;
164 
165         for (int i = 0; i < 300; i++) {
166             DnsQueryLog::Record record(30, 1000, 1000, "www.example.com", serversV4, 10);
167             queryLog.push(std::move(record));
168         }
169 
170         // Verify that queryLog has the default number of records. The default size defined in
171         // DnsQueryLog.h is 200.
172         const std::string output = captureDumpOutput(queryLog);
173         verifyDumpOutput(output, std::vector(200, 30));
174     }
175 }
176 
177 }  // namespace android::net
178