Merge "Parse and validate txt records." into nyc-dev (343e1d8a) · Commits · e / os / android_frameworks_base

core/java/android/net/nsd/NsdServiceInfo.java

+96 −2

Original line number	Diff line number	Diff line
		@@ -16,8 +16,11 @@

		package android.net.nsd;

		import android.annotation.NonNull;
		import android.os.Parcelable;
		import android.os.Parcel;
		import android.text.TextUtils;
		import android.util.Base64;
		import android.util.Log;
		import android.util.ArrayMap;

		@@ -95,8 +98,99 @@ public final class NsdServiceInfo implements Parcelable {
		mPort = p;
		}

		/**
		* Unpack txt information from a base-64 encoded byte array.
		*
		* @param rawRecords The raw base64 encoded records string read from netd.
		*
		* @hide
		*/
		public void setTxtRecords(@NonNull String rawRecords) {
		byte[] txtRecordsRawBytes = Base64.decode(rawRecords, Base64.DEFAULT);

		// There can be multiple TXT records after each other. Each record has to following format:
		//
		// byte type required meaning
		// ------------------- ------------------- -------- ----------------------------------
		// 0 unsigned 8 bit yes size of record excluding this byte
		// 1 - n ASCII but not '=' yes key
		// n + 1 '=' optional separator of key and value
		// n + 2 - record size uninterpreted bytes optional value
		//
		// Example legal records:
		// [11, 'm', 'y', 'k', 'e', 'y', '=', 0x0, 0x4, 0x65, 0x7, 0xff]
		// [17, 'm', 'y', 'K', 'e', 'y', 'W', 'i', 't', 'h', 'N', 'o', 'V', 'a', 'l', 'u', 'e', '=']
		// [12, 'm', 'y', 'B', 'o', 'o', 'l', 'e', 'a', 'n', 'K', 'e', 'y']
		//
		// Example corrupted records
		// [3, =, 1, 2] <- key is empty
		// [3, 0, =, 2] <- key contains non-ASCII character. We handle this by replacing the
		// invalid characters instead of skipping the record.
		// [30, 'a', =, 2] <- length exceeds total left over bytes in the TXT records array, we
		// handle this by reducing the length of the record as needed.
		int pos = 0;
		while (pos < txtRecordsRawBytes.length) {
		// recordLen is an unsigned 8 bit value
		int recordLen = txtRecordsRawBytes[pos] & 0xff;
		pos += 1;

		try {
		if (recordLen == 0) {
		throw new IllegalArgumentException("Zero sized txt record");
		} else if (pos + recordLen > txtRecordsRawBytes.length) {
		Log.w(TAG, "Corrupt record length (pos = " + pos + "): " + recordLen);
		recordLen = txtRecordsRawBytes.length - pos;
		}

		// Decode key-value records
		String key = null;
		byte[] value = null;
		int valueLen = 0;
		for (int i = pos; i < pos + recordLen; i++) {
		if (key == null) {
		if (txtRecordsRawBytes[i] == '=') {
		key = new String(txtRecordsRawBytes, pos, i - pos,
		StandardCharsets.US_ASCII);
		}
		} else {
		if (value == null) {
		value = new byte[recordLen - key.length() - 1];
		}
		value[valueLen] = txtRecordsRawBytes[i];
		valueLen++;
		}
		}

		// If '=' was not found we have a boolean record
		if (key == null) {
		key = new String(txtRecordsRawBytes, pos, recordLen, StandardCharsets.US_ASCII);
		}

		if (TextUtils.isEmpty(key)) {
		// Empty keys are not allowed (RFC6763 6.4)
		throw new IllegalArgumentException("Invalid txt record (key is empty)");
		}

		if (getAttributes().containsKey(key)) {
		// When we have a duplicate record, the later ones are ignored (RFC6763 6.4)
		throw new IllegalArgumentException("Invalid txt record (duplicate key \"" + key + "\")");
		}

		setAttribute(key, value);
		} catch (IllegalArgumentException e) {
		Log.e(TAG, "While parsing txt records (pos = " + pos + "): " + e.getMessage());
		}

		pos += recordLen;
		}
		}

		/** @hide */
		public void setAttribute(String key, byte[] value) {
		if (TextUtils.isEmpty(key)) {
		throw new IllegalArgumentException("Key cannot be empty");
		}

		// Key must be printable US-ASCII, excluding =.
		for (int i = 0; i < key.length(); ++i) {
		char character = key.charAt(i);
		@@ -177,10 +271,10 @@ public final class NsdServiceInfo implements Parcelable {
		}

		/** @hide */
		public byte[] getTxtRecord() {
		public @NonNull byte[] getTxtRecord() {
		int txtRecordSize = getTxtRecordSize();
		if (txtRecordSize == 0) {
		return null;
		return new byte[]{};
		}

		byte[] txtRecord = new byte[txtRecordSize];

services/core/java/com/android/server/NsdService.java

+5 −17

Original line number	Diff line number	Diff line
		@@ -30,16 +30,14 @@ import android.os.Message;
		import android.os.Messenger;
		import android.os.UserHandle;
		import android.provider.Settings;
		import android.util.Base64;
		import android.util.Slog;
		import android.util.SparseArray;

		import java.io.FileDescriptor;
		import java.io.PrintWriter;
		import java.io.UnsupportedEncodingException;
		import java.net.InetAddress;
		import java.util.HashMap;
		import java.util.Locale;
		import java.util.Map;
		import java.util.concurrent.CountDownLatch;

		import com.android.internal.util.AsyncChannel;
		@@ -492,6 +490,7 @@ public class NsdService extends INsdManager.Stub {
		clientInfo.mResolvedService.setServiceName(name);
		clientInfo.mResolvedService.setServiceType(type);
		clientInfo.mResolvedService.setPort(Integer.parseInt(cooked[4]));
		clientInfo.mResolvedService.setTxtRecords(cooked[6]);

		stopResolveService(id);
		removeRequestMap(clientId, id, clientInfo);
		@@ -708,20 +707,9 @@ public class NsdService extends INsdManager.Stub {
		if (DBG) Slog.d(TAG, "registerService: " + regId + " " + service);
		try {
		Command cmd = new Command("mdnssd", "register", regId, service.getServiceName(),
		service.getServiceType(), service.getPort());

		// Add TXT records as additional arguments.
		Map<String, byte[]> txtRecords = service.getAttributes();
		for (String key : txtRecords.keySet()) {
		try {
		// TODO: Send encoded TXT record as bytes once NDC/netd supports binary data.
		byte[] recordValue = txtRecords.get(key);
		cmd.appendArg(String.format(Locale.US, "%s=%s", key,
		recordValue != null ? new String(recordValue, "UTF_8") : ""));
		} catch (UnsupportedEncodingException e) {
		Slog.e(TAG, "Failed to encode txtRecord " + e);
		}
		}
		service.getServiceType(), service.getPort(),
		Base64.encodeToString(service.getTxtRecord(), Base64.DEFAULT)
		.replace("\n", ""));

		mNativeConnector.execute(cmd);
		} catch(NativeDaemonConnectorException e) {