Add DomainsUtils class to encode/decode domain names.
Both encode and deocde methods support message compression which is
described in RFC1035 section 4.1.4. We can leverage both methods in
a follow-up CL to parse DHCPv4 option 119 and DNSSL RA option.
This cl also adds maxLabelCount argument for DnsRecordParser#parseName
to prevent the potential recursion from overflowing the stack.
Bug: 189865016
Test: atest NetworkStaticLibTests
Change-Id: I90101ecda64bfecb0233e80ea93c91c204fbf176
diff --git a/staticlibs/device/com/android/net/module/util/DomainUtils.java b/staticlibs/device/com/android/net/module/util/DomainUtils.java
index 80e0b64..b327fd0 100644
--- a/staticlibs/device/com/android/net/module/util/DomainUtils.java
+++ b/staticlibs/device/com/android/net/module/util/DomainUtils.java
@@ -123,7 +123,7 @@
* @return domain name(s) string array with space separated, or empty string if decode fails.
*/
@NonNull
- public static String[] decode(@NonNull final ByteBuffer buffer, boolean compression) {
+ public static ArrayList<String> decode(@NonNull final ByteBuffer buffer, boolean compression) {
final ArrayList<String> domainList = new ArrayList<>();
while (buffer.remaining() > 0) {
try {
@@ -138,6 +138,6 @@
break;
}
}
- return domainList.toArray(new String[0]);
+ return domainList;
}
}
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/DomainUtilsTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/DomainUtilsTest.java
index 606ed5f..5eaf2ad 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/DomainUtilsTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/DomainUtilsTest.java
@@ -30,6 +30,9 @@
import org.junit.runner.RunWith;
import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.List;
@RunWith(AndroidJUnit4.class)
@SmallTest
@@ -168,39 +171,40 @@
@Test
public void testDecodeDomainNames() {
+ ArrayList<String> suffixStringList;
String suffixes = "06676F6F676C6503636F6D00" // google.com
+ "076578616D706C6503636F6D00" // example.com
+ "06676F6F676C6500"; // google
- String[] expected = new String[] {"google.com", "example.com"};
+ List<String> expected = Arrays.asList("google.com", "example.com");
ByteBuffer buffer = ByteBuffer.wrap(HexEncoding.decode(suffixes));
- String[] suffixString = DomainUtils.decode(buffer, false /* compression */);
- assertArrayEquals(expected, suffixString);
+ suffixStringList = DomainUtils.decode(buffer, false /* compression */);
+ assertEquals(expected, suffixStringList);
// include suffix with invalid length: 64
suffixes = "06676F6F676C6503636F6D00" // google.com
+ "406578616D706C6503636F6D00" // example.com(length=64)
+ "06676F6F676C6500"; // google
- expected = new String[] {"google.com"};
+ expected = Arrays.asList("google.com");
buffer = ByteBuffer.wrap(HexEncoding.decode(suffixes));
- suffixString = DomainUtils.decode(buffer, false /* compression */);
- assertArrayEquals(expected, suffixString);
+ suffixStringList = DomainUtils.decode(buffer, false /* compression */);
+ assertEquals(expected, suffixStringList);
// include suffix with invalid length: 0
suffixes = "06676F6F676C6503636F6D00" // google.com
+ "076578616D706C6503636F6D00" // example.com
+ "00676F6F676C6500"; // google(length=0)
- expected = new String[] {"google.com", "example.com"};
+ expected = Arrays.asList("google.com", "example.com");
buffer = ByteBuffer.wrap(HexEncoding.decode(suffixes));
- suffixString = DomainUtils.decode(buffer, false /* compression */);
- assertArrayEquals(expected, suffixString);
+ suffixStringList = DomainUtils.decode(buffer, false /* compression */);
+ assertEquals(expected, suffixStringList);
suffixes =
"076578616D706C6504636F727006676F6F676C6503636F6D00" // example.corp.google.com
+ "C008" // corp.google.com
+ "C00D"; // google.com
- expected = new String[] {"example.corp.google.com", "corp.google.com", "google.com"};
+ expected = Arrays.asList("example.corp.google.com", "corp.google.com", "google.com");
buffer = ByteBuffer.wrap(HexEncoding.decode(suffixes));
- suffixString = DomainUtils.decode(buffer, true /* compression */);
- assertArrayEquals(expected, suffixString);
+ suffixStringList = DomainUtils.decode(buffer, true /* compression */);
+ assertEquals(expected, suffixStringList);
}
}