| /* |
| * Copyright (C) 2019 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.net.module.util; |
| |
| import static com.android.net.module.util.DnsPacketUtils.DnsRecordParser; |
| |
| import static org.junit.Assert.assertEquals; |
| import static org.junit.Assert.assertThrows; |
| |
| import androidx.test.filters.SmallTest; |
| import androidx.test.runner.AndroidJUnit4; |
| |
| import org.junit.Test; |
| import org.junit.runner.RunWith; |
| |
| import java.nio.ByteBuffer; |
| |
| @RunWith(AndroidJUnit4.class) |
| @SmallTest |
| public class DnsPacketUtilsTest { |
| |
| /** |
| * Verifies that the compressed NAME field in the answer section of the DNS message is parsed |
| * successfully when name compression is permitted. Additionally, verifies that a |
| * {@link DnsPacket.ParseException} is thrown in a hypothetical scenario where name compression |
| * is not expected. |
| */ |
| @Test |
| public void testParsingAnswerSectionNameCompressed() throws Exception { |
| final byte[] v4blobNameCompressedAnswer = new byte[] { |
| /* Header */ |
| 0x55, 0x66, /* Transaction ID */ |
| (byte) 0x81, (byte) 0x80, /* Flags */ |
| 0x00, 0x01, /* Questions */ |
| 0x00, 0x01, /* Answer RRs */ |
| 0x00, 0x00, /* Authority RRs */ |
| 0x00, 0x00, /* Additional RRs */ |
| /* Queries */ |
| 0x03, 0x77, 0x77, 0x77, 0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6c, 0x65, |
| 0x03, 0x63, 0x6f, 0x6d, 0x00, /* Name */ |
| 0x00, 0x01, /* Type */ |
| 0x00, 0x01, /* Class */ |
| /* Answers */ |
| (byte) 0xc0, 0x0c, /* Name */ |
| 0x00, 0x01, /* Type */ |
| 0x00, 0x01, /* Class */ |
| 0x00, 0x00, 0x01, 0x2b, /* TTL */ |
| 0x00, 0x04, /* Data length */ |
| (byte) 0xac, (byte) 0xd9, (byte) 0xa1, (byte) 0x84 /* Address */ |
| }; |
| final int answerOffsetBytePosition = 32; |
| final ByteBuffer nameCompressedBuf = ByteBuffer.wrap(v4blobNameCompressedAnswer); |
| |
| nameCompressedBuf.position(answerOffsetBytePosition); |
| assertThrows(DnsPacket.ParseException.class, () -> DnsRecordParser.parseName( |
| nameCompressedBuf, /* depth= */ 0, /* isNameCompressionSupported= */false)); |
| |
| nameCompressedBuf.position(answerOffsetBytePosition); |
| String domainName = DnsRecordParser.parseName( |
| nameCompressedBuf, /* depth= */ 0, /* isNameCompressionSupported= */true); |
| assertEquals(domainName, "www.google.com"); |
| } |
| |
| /** |
| * Verifies that an uncompressed NAME field in the answer section of the DNS message is parsed |
| * successfully irrespective of whether name compression is permitted. |
| */ |
| @Test |
| public void testParsingAnswerSectionNoNameCompression() throws Exception { |
| final byte[] v4blobNoNameCompression = new byte[] { |
| /* Header */ |
| 0x55, 0x66, /* Transaction ID */ |
| (byte) 0x81, (byte) 0x80, /* Flags */ |
| 0x00, 0x01, /* Questions */ |
| 0x00, 0x01, /* Answer RRs */ |
| 0x00, 0x00, /* Authority RRs */ |
| 0x00, 0x00, /* Additional RRs */ |
| /* Queries */ |
| 0x03, 0x77, 0x77, 0x77, 0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6c, 0x65, |
| 0x03, 0x63, 0x6f, 0x6d, 0x00, /* Name */ |
| 0x00, 0x01, /* Type */ |
| 0x00, 0x01, /* Class */ |
| /* Answers */ |
| 0x03, 0x77, 0x77, 0x77, 0x06, 0x67, 0x6F, 0x6F, 0x67, 0x6c, 0x65, |
| 0x03, 0x63, 0x6f, 0x6d, 0x00, /* Name */ |
| 0x00, 0x01, /* Type */ |
| 0x00, 0x01, /* Class */ |
| 0x00, 0x00, 0x01, 0x2b, /* TTL */ |
| 0x00, 0x04, /* Data length */ |
| (byte) 0xac, (byte) 0xd9, (byte) 0xa1, (byte) 0x84 /* Address */ |
| }; |
| final int answerOffsetBytePosition = 32; |
| final ByteBuffer notNameCompressedBuf = ByteBuffer.wrap(v4blobNoNameCompression); |
| |
| notNameCompressedBuf.position(answerOffsetBytePosition); |
| String domainName = DnsRecordParser.parseName( |
| notNameCompressedBuf, /* depth= */ 0, /* isNameCompressionSupported= */ true); |
| assertEquals(domainName, "www.google.com"); |
| |
| notNameCompressedBuf.position(answerOffsetBytePosition); |
| domainName = DnsRecordParser.parseName( |
| notNameCompressedBuf, /* depth= */ 0, /* isNameCompressionSupported= */ false); |
| assertEquals(domainName, "www.google.com"); |
| } |
| } |