GAP: Allow BT name upto 248 bytes from setName (e1c6797b) · Commits · e / os / android_packages_modules_Bluetooth

android/app/src/com/android/bluetooth/Utils.java

+43 −1

Original line number	Diff line number	Diff line
		@@ -63,7 +63,6 @@ import android.provider.DeviceConfig;
		import android.provider.Telephony;
		import android.util.Log;

		import androidx.annotation.RequiresApi;

		import com.android.bluetooth.btservice.AdapterService;
		import com.android.bluetooth.btservice.ProfileService;
		@@ -1235,4 +1234,47 @@ public final class Utils {
		return pm.hasSystemFeature(PackageManager.FEATURE_TELEVISION)
		\|\| pm.hasSystemFeature(PackageManager.FEATURE_LEANBACK);
		}

		/**
		* Returns the longest prefix of a string for which the UTF-8 encoding fits into the given
		* number of bytes, with the additional guarantee that the string is not truncated in the middle
		* of a valid surrogate pair.
		*
		* <p>Unpaired surrogates are counted as taking 3 bytes of storage. However, a subsequent
		* attempt to actually encode a string containing unpaired surrogates is likely to be rejected
		* by the UTF-8 implementation.
		*
		* <p>(copied from framework/base/core/java/android/text/TextUtils.java)
		*
		* @param str a string
		* @param maxbytes the maximum number of UTF-8 encoded bytes
		* @return the beginning of the string, so that it uses at most maxbytes bytes in UTF-8
		* @throws IndexOutOfBoundsException if maxbytes is negative
		*/
		public static String truncateStringForUtf8Storage(String str, int maxbytes) {
		if (maxbytes < 0) {
		throw new IndexOutOfBoundsException();
		}

		int bytes = 0;
		for (int i = 0, len = str.length(); i < len; i++) {
		char c = str.charAt(i);
		if (c < 0x80) {
		bytes += 1;
		} else if (c < 0x800) {
		bytes += 2;
		} else if (c < Character.MIN_SURROGATE
		\|\| c > Character.MAX_SURROGATE
		\|\| str.codePointAt(i) < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
		bytes += 3;
		} else {
		bytes += 4;
		i += (bytes > maxbytes) ? 0 : 1;
		}
		if (bytes > maxbytes) {
		return str.substring(0, i);
		}
		}
		return str;
		}
		}

android/app/src/com/android/bluetooth/btservice/AdapterProperties.java

+6 −1

Original line number	Diff line number	Diff line
		@@ -82,6 +82,7 @@ class AdapterProperties {
		"persist.bluetooth.a2dp_offload.disabled";

		private static final long DEFAULT_DISCOVERY_TIMEOUT_MS = 12800;
		@VisibleForTesting static final int BLUETOOTH_NAME_MAX_LENGTH_BYTES = 248;
		private static final int BD_ADDR_LEN = 6; // in bytes

		private volatile String mName;
		@@ -318,7 +319,11 @@ class AdapterProperties {
		boolean setName(String name) {
		synchronized (mObject) {
		return mService.getNative()
		.setAdapterProperty(AbstractionLayer.BT_PROPERTY_BDNAME, name.getBytes());
		.setAdapterProperty(
		AbstractionLayer.BT_PROPERTY_BDNAME,
		Utils.truncateStringForUtf8Storage(
		name, BLUETOOTH_NAME_MAX_LENGTH_BYTES)
		.getBytes());
		}
		}

android/app/tests/unit/src/com/android/bluetooth/UtilsTest.java

+70 −0

Original line number	Diff line number	Diff line
		@@ -47,6 +47,7 @@ import java.io.InputStream;
		import java.io.OutputStream;
		import java.nio.ByteBuffer;
		import java.nio.ByteOrder;
		import java.nio.charset.StandardCharsets;
		import java.util.UUID;

		/**
		@@ -249,4 +250,73 @@ public class UtilsTest {
		doThrow(new IOException()).when(os).close();
		Utils.safeCloseStream(os);
		}

		@Test
		public void truncateUtf8_toZeroLength_isEmpty() {
		assertThat(Utils.truncateStringForUtf8Storage("abc", 0)).isEmpty();
		}

		@Test
		public void truncateUtf8_longCase_isExpectedResult() {
		StringBuilder builder = new StringBuilder();

		int n = 50;
		for (int i = 0; i < 2 * n; i++) {
		builder.append("哈");
		}
		String initial = builder.toString();
		String result = Utils.truncateStringForUtf8Storage(initial, n);

		// Result should be the beginning of initial
		assertThat(initial.startsWith(result)).isTrue();

		// Result should take less than n bytes in UTF-8
		assertThat(result.getBytes(StandardCharsets.UTF_8).length).isAtMost(n);

		// result + the next codePoint should take strictly more than
		// n bytes in UTF-8
		assertThat(
		initial.substring(0, initial.offsetByCodePoints(result.length(), 1))
		.getBytes(StandardCharsets.UTF_8)
		.length)
		.isGreaterThan(n);
		}

		@Test
		public void truncateUtf8_untruncatedString_isEqual() {
		String s = "sf\u20ACgk\u00E9ls\u00E9fg";
		assertThat(Utils.truncateStringForUtf8Storage(s, 100)).isEqualTo(s);
		}

		@Test
		public void truncateUtf8_inMiddleOfSurrogate_isStillUtf8() {
		StringBuilder builder = new StringBuilder();
		String beginning = "a";
		builder.append(beginning);
		builder.append(Character.toChars(0x1D11E));

		// \u1D11E is a surrogate and needs 4 bytes in UTF-8. beginning == "a" uses
		// only 1 bytes in UTF8
		// As we allow only 3 bytes for the whole string, so just 2 for this
		// codePoint, there is not enough place and the string will be truncated
		// just before it
		assertThat(Utils.truncateStringForUtf8Storage(builder.toString(), 3)).isEqualTo(beginning);
		}

		@Test
		public void truncateUtf8_inMiddleOfChar_isStillUtf8() {
		StringBuilder builder = new StringBuilder();
		String beginning = "a";
		builder.append(beginning);
		builder.append(Character.toChars(0x20AC));

		// Like above, \u20AC uses 3 bytes in UTF-8, with "beginning", that makes
		// 4 bytes so it is too big and should be truncated
		assertThat(Utils.truncateStringForUtf8Storage(builder.toString(), 3)).isEqualTo(beginning);
		}

		@Test(expected = IndexOutOfBoundsException.class)
		public void truncateUtf8_toNegativeSize_ThrowsException() {
		Utils.truncateStringForUtf8Storage("abc", -1);
		}
		}

android/app/tests/unit/src/com/android/bluetooth/btservice/AdapterPropertiesTest.java

+48 −0

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@ import static com.google.common.truth.Truth.assertThat;

		import static org.mockito.Mockito.any;
		import static org.mockito.Mockito.doReturn;
		import static org.mockito.Mockito.eq;
		import static org.mockito.Mockito.times;
		import static org.mockito.Mockito.verify;
		import static org.mockito.Mockito.when;
		@@ -37,6 +38,7 @@ import com.android.bluetooth.Utils;
		import org.junit.Before;
		import org.junit.Test;
		import org.junit.runner.RunWith;
		import org.mockito.ArgumentCaptor;
		import org.mockito.Mock;
		import org.mockito.MockitoAnnotations;

		@@ -110,4 +112,50 @@ public class AdapterPropertiesTest {
		assertThat(mAdapterProperties.getBondedDevices()[0].getAddress())
		.isEqualTo(Utils.getAddressStringFromByte(TEST_BT_ADDR_BYTES_2));
		}

		@Test
		public void setName_shortName_isEqual() {
		StringBuilder builder = new StringBuilder();
		String stringName = "Wonderful Bluetooth Name Using utf8";
		builder.append(stringName);
		builder.append(Character.toChars(0x20AC));

		String initial = builder.toString();

		final ArgumentCaptor<byte[]> argumentName = ArgumentCaptor.forClass(byte[].class);

		mAdapterProperties.setName(initial);
		verify(mNativeInterface)
		.setAdapterProperty(
		eq(AbstractionLayer.BT_PROPERTY_BDNAME), argumentName.capture());

		assertThat(argumentName.getValue()).isEqualTo(initial.getBytes());
		}

		@Test
		public void setName_tooLongName_isTruncated() {
		StringBuilder builder = new StringBuilder();
		String stringName = "Wonderful Bluetooth Name Using utf8 ... But this name is too long";
		builder.append(stringName);

		int n = 300;
		for (int i = 0; i < 2 * n; i++) {
		builder.append(Character.toChars(0x20AC));
		}

		String initial = builder.toString();

		final ArgumentCaptor<byte[]> argumentName = ArgumentCaptor.forClass(byte[].class);

		mAdapterProperties.setName(initial);
		verify(mNativeInterface)
		.setAdapterProperty(
		eq(AbstractionLayer.BT_PROPERTY_BDNAME), argumentName.capture());

		byte[] name = argumentName.getValue();

		assertThat(name.length).isLessThan(initial.getBytes().length);

		assertThat(initial).startsWith(new String(name));
		}
		}