LineageOS/android_packages_modules_Connectivity
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Avoid going over max service name length when renaming NSD services

Browse Source 
As per  RFC 1034/1035, the max size of the label is 63 bytes. It should
also be guaranteed when the serviceName is renamed due to the conflict.

Bug: 265865456
Test: atest FrameworksNetTests
Change-Id: I077d8abdb91071db62b9618d9918e3a12682aaf4
This commit is contained in:
Yuyang Huang
2023-05-02 17:14:22 +09:00
parent 441a32e39d
commit de802c8dc4
6 changed files with 83 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
service-t/src/com/android/server/NsdService.java
View File

@@ -23,6 +23,7 @@ import static android.provider.DeviceConfig.NAMESPACE_CONNECTIVITY;
import static android.provider.DeviceConfig.NAMESPACE_TETHERING;
import static com.android.modules.utils.build.SdkLevel.isAtLeastU;
import static com.android.server.connectivity.mdns.MdnsRecord.MAX_LABEL_LENGTH;
import android.annotation.NonNull;
import android.annotation.Nullable;
@@ -73,6 +74,7 @@ import com.android.server.connectivity.mdns.MdnsServiceBrowserListener;
import com.android.server.connectivity.mdns.MdnsServiceInfo;
import com.android.server.connectivity.mdns.MdnsSocketClientBase;
import com.android.server.connectivity.mdns.MdnsSocketProvider;
import com.android.server.connectivity.mdns.util.MdnsUtils;
import java.io.FileDescriptor;
import java.io.PrintWriter;
@@ -81,11 +83,6 @@ import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
@@ -108,8 +105,6 @@ public class NsdService extends INsdManager.Stub {
*/
private static final String MDNS_DISCOVERY_MANAGER_VERSION = "mdns_discovery_manager_version";
private static final String LOCAL_DOMAIN_NAME = "local";
// Max label length as per RFC 1034/1035
private static final int MAX_LABEL_LENGTH = 63;
/**
* Enable advertising using the Java MdnsAdvertiser, instead of the legacy mdnsresponder
@@ -570,18 +565,7 @@ public class NsdService extends INsdManager.Stub {
*/
@NonNull
private String truncateServiceName(@NonNull String originalName) {
// UTF-8 is at most 4 bytes per character; return early in the common case where
// the name can't possibly be over the limit given its string length.
if (originalName.length() <= MAX_LABEL_LENGTH / 4) return originalName;
final Charset utf8 = StandardCharsets.UTF_8;
final CharsetEncoder encoder = utf8.newEncoder();
final ByteBuffer out = ByteBuffer.allocate(MAX_LABEL_LENGTH);
// encode will write as many characters as possible to the out buffer, and just
// return an overflow code if there were too many characters (no need to check the
// return code here, this method truncates the name on purpose).
encoder.encode(CharBuffer.wrap(originalName), out, true /* endOfInput */);
return new String(out.array(), 0, out.position(), utf8);
return MdnsUtils.truncateServiceName(originalName, MAX_LABEL_LENGTH);
}
private void stopDiscoveryManagerRequest(ClientRequest request, int clientId, int id,