Merge "Move byte logics from ApfFilter into BitsUtil"

am: 21b9b3a8ff

Change-Id: I9234b9dcb527de8a67bebab8cebc35e5b96aa986

core/java/com/android/internal/util/BitUtils.java

@@ -21,10 +21,16 @@ import android.annotation.Nullable;
 
 import libcore.util.Objects;
 
+import java.nio.ByteBuffer;
 import java.util.Arrays;
 import java.util.UUID;
 
-public class BitUtils {
+/**
+ * A utility class for handling unsigned integers and unsigned arithmetics, as well as syntactic
+ * sugar methods for ByteBuffer. Useful for networking and packet manipulations.
+ * {@hide}
+ */
+public final class BitUtils {
     private BitUtils() {}
 
     public static boolean maskedEquals(long a, long b, long mask) {
@@ -76,4 +82,46 @@ public class BitUtils {
         }
         return packed;
     }
+
+    public static int uint8(byte b) {
+        return b & 0xff;
+    }
+
+    public static int uint16(short s) {
+        return s & 0xffff;
+    }
+
+    public static long uint32(int i) {
+        return i & 0xffffffffL;
+    }
+
+    public static int bytesToBEInt(byte[] bytes) {
+        return (uint8(bytes[0]) << 24)
+                + (uint8(bytes[1]) << 16)
+                + (uint8(bytes[2]) << 8)
+                + (uint8(bytes[3]));
+    }
+
+    public static int bytesToLEInt(byte[] bytes) {
+        return Integer.reverseBytes(bytesToBEInt(bytes));
+    }
+
+    public static int getUint8(ByteBuffer buffer, int position) {
+        return uint8(buffer.get(position));
+    }
+
+    public static int getUint16(ByteBuffer buffer, int position) {
+        return uint16(buffer.getShort(position));
+    }
+
+    public static long getUint32(ByteBuffer buffer, int position) {
+        return uint32(buffer.getInt(position));
+    }
+
+    public static void put(ByteBuffer buffer, int position, byte[] bytes) {
+        final int original = buffer.position();
+        buffer.position(position);
+        buffer.put(bytes);
+        buffer.position(original);
+    }
 }

services/net/java/android/net/apf/ApfFilter.java

@@ -18,6 +18,14 @@ package android.net.apf;
 
 import static android.system.OsConstants.*;
 
+import static com.android.internal.util.BitUtils.bytesToBEInt;
+import static com.android.internal.util.BitUtils.getUint16;
+import static com.android.internal.util.BitUtils.getUint32;
+import static com.android.internal.util.BitUtils.getUint8;
+import static com.android.internal.util.BitUtils.uint16;
+import static com.android.internal.util.BitUtils.uint32;
+import static com.android.internal.util.BitUtils.uint8;
+
 import android.os.SystemClock;
 import android.net.LinkAddress;
 import android.net.LinkProperties;
@@ -1157,41 +1165,9 @@ public class ApfFilter {
         }
     }
 
-    private static int uint8(byte b) {
-        return b & 0xff;
-    }
-
-    private static int uint16(short s) {
-        return s & 0xffff;
-    }
-
-    private static long uint32(int i) {
-        return i & 0xffffffffL;
-    }
-
-    private static int getUint8(ByteBuffer buffer, int position) {
-        return uint8(buffer.get(position));
-    }
-
-    private static int getUint16(ByteBuffer buffer, int position) {
-        return uint16(buffer.getShort(position));
-    }
-
-    private static long getUint32(ByteBuffer buffer, int position) {
-        return uint32(buffer.getInt(position));
-    }
-
     // TODO: move to android.net.NetworkUtils
     @VisibleForTesting
     public static int ipv4BroadcastAddress(byte[] addrBytes, int prefixLength) {
-        return bytesToInt(addrBytes) | (int) (uint32(-1) >>> prefixLength);
-    }
-
-    @VisibleForTesting
-    public static int bytesToInt(byte[] addrBytes) {
-        return (uint8(addrBytes[0]) << 24)
-                + (uint8(addrBytes[1]) << 16)
-                + (uint8(addrBytes[2]) << 8)
-                + (uint8(addrBytes[3]));
+        return bytesToBEInt(addrBytes) | (int) (uint32(-1) >>> prefixLength);
     }
 }

tests/net/java/android/net/apf/ApfTest.java

@@ -39,6 +39,8 @@ import static android.system.OsConstants.*;
 
 import com.android.frameworks.tests.net.R;
 import com.android.internal.util.HexDump;
+import static com.android.internal.util.BitUtils.bytesToBEInt;
+import static com.android.internal.util.BitUtils.put;
 
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
@@ -65,7 +67,7 @@ import libcore.io.Streams;
  * Tests for APF program generator and interpreter.
  *
  * Build, install and run with:
- *  runtest frameworks-services -c android.net.apf.ApfTest
+ *  runtest frameworks-net -c android.net.apf.ApfTest
  */
 public class ApfTest extends AndroidTestCase {
     private static final int TIMEOUT_MS = 500;
@@ -1235,15 +1237,6 @@ public class ApfTest extends AndroidTestCase {
             byte[] apf_program);
 
     @SmallTest
-    public void testBytesToInt() {
-        assertEquals(0x00000000, ApfFilter.bytesToInt(IPV4_ANY_HOST_ADDR));
-        assertEquals(0xffffffff, ApfFilter.bytesToInt(IPV4_BROADCAST_ADDRESS));
-        assertEquals(0x0a000001, ApfFilter.bytesToInt(MOCK_IPV4_ADDR));
-        assertEquals(0x0a000002, ApfFilter.bytesToInt(ANOTHER_IPV4_ADDR));
-        assertEquals(0x0a001fff, ApfFilter.bytesToInt(MOCK_BROADCAST_IPV4_ADDR));
-        assertEquals(0xe0000001, ApfFilter.bytesToInt(MOCK_MULTICAST_IPV4_ADDR));
-    }
-
     public void testBroadcastAddress() throws Exception {
         assertEqualsIp("255.255.255.255", ApfFilter.ipv4BroadcastAddress(IPV4_ANY_HOST_ADDR, 0));
         assertEqualsIp("0.0.0.0", ApfFilter.ipv4BroadcastAddress(IPV4_ANY_HOST_ADDR, 32));
@@ -1257,7 +1250,7 @@ public class ApfTest extends AndroidTestCase {
     }
 
     public void assertEqualsIp(String expected, int got) throws Exception {
-        int want = ApfFilter.bytesToInt(InetAddress.getByName(expected).getAddress());
+        int want = bytesToBEInt(InetAddress.getByName(expected).getAddress());
         assertEquals(want, got);
     }
 }

tests/net/java/com/android/internal/util/BitUtilsTest.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2017 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.internal.util;
+
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import java.nio.ByteBuffer;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.assertEquals;
+import static com.android.internal.util.BitUtils.*;
+
+@SmallTest
+@RunWith(AndroidJUnit4.class)
+public class BitUtilsTest {
+
+    @Test
+    public void testUnsignedByteWideningConversions() {
+        byte b0 = 0;
+        byte b1 = 1;
+        byte bm1 = -1;
+        assertEquals(0, uint8(b0));
+        assertEquals(1, uint8(b1));
+        assertEquals(127, uint8(Byte.MAX_VALUE));
+        assertEquals(128, uint8(Byte.MIN_VALUE));
+        assertEquals(255, uint8(bm1));
+        assertEquals(255, uint8((byte)255));
+    }
+
+    @Test
+    public void testUnsignedShortWideningConversions() {
+        short s0 = 0;
+        short s1 = 1;
+        short sm1 = -1;
+        assertEquals(0, uint16(s0));
+        assertEquals(1, uint16(s1));
+        assertEquals(32767, uint16(Short.MAX_VALUE));
+        assertEquals(32768, uint16(Short.MIN_VALUE));
+        assertEquals(65535, uint16(sm1));
+        assertEquals(65535, uint16((short)65535));
+    }
+
+    @Test
+    public void testUnsignedIntWideningConversions() {
+        assertEquals(0, uint32(0));
+        assertEquals(1, uint32(1));
+        assertEquals(2147483647L, uint32(Integer.MAX_VALUE));
+        assertEquals(2147483648L, uint32(Integer.MIN_VALUE));
+        assertEquals(4294967295L, uint32(-1));
+        assertEquals(4294967295L, uint32((int)4294967295L));
+    }
+
+    @Test
+    public void testBytesToInt() {
+        assertEquals(0x00000000, bytesToBEInt(bytes(0, 0, 0, 0)));
+        assertEquals(0xffffffff, bytesToBEInt(bytes(255, 255, 255, 255)));
+        assertEquals(0x0a000001, bytesToBEInt(bytes(10, 0, 0, 1)));
+        assertEquals(0x0a000002, bytesToBEInt(bytes(10, 0, 0, 2)));
+        assertEquals(0x0a001fff, bytesToBEInt(bytes(10, 0, 31, 255)));
+        assertEquals(0xe0000001, bytesToBEInt(bytes(224, 0, 0, 1)));
+
+        assertEquals(0x00000000, bytesToLEInt(bytes(0, 0, 0, 0)));
+        assertEquals(0x01020304, bytesToLEInt(bytes(4, 3, 2, 1)));
+        assertEquals(0xffff0000, bytesToLEInt(bytes(0, 0, 255, 255)));
+    }
+
+    @Test
+    public void testUnsignedGetters() {
+      ByteBuffer b = ByteBuffer.allocate(4);
+      b.putInt(0xffff);
+
+      assertEquals(0x0, getUint8(b, 0));
+      assertEquals(0x0, getUint8(b, 1));
+      assertEquals(0xff, getUint8(b, 2));
+      assertEquals(0xff, getUint8(b, 3));
+
+      assertEquals(0x0, getUint16(b, 0));
+      assertEquals(0xffff, getUint16(b, 2));
+
+      b.rewind();
+      b.putInt(0xffffffff);
+      assertEquals(0xffffffffL, getUint32(b, 0));
+    }
+
+    static byte[] bytes(int b1, int b2, int b3, int b4) {
+        return new byte[] {b(b1), b(b2), b(b3), b(b4)};
+    }
+
+    static byte b(int i) {
+        return (byte) i;
+    }
+}