Minor changes to LinkAddress.

1. Simplify the parceling code. Since the InetAddress inside a
   LinkAddress can never be null, we don't need to special-case
   the case where it is.
2. Add / update method documentation.
3. Write a unit test.

Change-Id: Iba0a8cecc683d55d736419965e72ee33dd66dc22

1 files changed, 213 insertions, 0 deletions

diff --git a/core/tests/coretests/src/android/net/LinkAddressTest.java b/core/tests/coretests/src/android/net/LinkAddressTest.java
new file mode 100644
index 0000000..389ff4d
--- /dev/null
+++ b/core/tests/coretests/src/android/net/LinkAddressTest.java
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2013 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 android.net;
+
+import java.net.Inet4Address;
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.net.InterfaceAddress;
+import java.net.NetworkInterface;
+import java.net.SocketException;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+import android.net.LinkAddress;
+import android.os.Parcel;
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+
+/**
+ * Tests for {@link LinkAddress}.
+ */
+public class LinkAddressTest extends AndroidTestCase {
+
+    private static final String V4 = "192.0.2.1";
+    private static final String V6 = "2001:db8::1";
+    private static final InetAddress V4_ADDRESS = NetworkUtils.numericToInetAddress(V4);
+    private static final InetAddress V6_ADDRESS = NetworkUtils.numericToInetAddress(V6);
+
+    public void testConstructors() throws SocketException {
+        LinkAddress address;
+
+        // Valid addresses work as expected.
+        address = new LinkAddress(V4_ADDRESS, 25);
+        assertEquals(V4_ADDRESS, address.getAddress());
+        assertEquals(25, address.getNetworkPrefixLength());
+
+        address = new LinkAddress(V6_ADDRESS, 127);
+        assertEquals(V6_ADDRESS, address.getAddress());
+        assertEquals(127, address.getNetworkPrefixLength());
+
+        address = new LinkAddress(V6 + "/64");
+        assertEquals(V6_ADDRESS, address.getAddress());
+        assertEquals(64, address.getNetworkPrefixLength());
+
+        address = new LinkAddress(V4 + "/23");
+        assertEquals(V4_ADDRESS, address.getAddress());
+        assertEquals(23, address.getNetworkPrefixLength());
+
+        // InterfaceAddress doesn't have a constructor. Fetch some from an interface.
+        List<InterfaceAddress> addrs = NetworkInterface.getByName("lo").getInterfaceAddresses();
+
+        // We expect to find 127.0.0.1/8 and ::1/128, in any order.
+        LinkAddress ipv4Loopback, ipv6Loopback;
+        assertEquals(2, addrs.size());
+        if (addrs.get(0).getAddress() instanceof Inet4Address) {
+            ipv4Loopback = new LinkAddress(addrs.get(0));
+            ipv6Loopback = new LinkAddress(addrs.get(1));
+        } else {
+            ipv4Loopback = new LinkAddress(addrs.get(1));
+            ipv6Loopback = new LinkAddress(addrs.get(0));
+        }
+
+        assertEquals(NetworkUtils.numericToInetAddress("127.0.0.1"), ipv4Loopback.getAddress());
+        assertEquals(8, ipv4Loopback.getNetworkPrefixLength());
+
+        assertEquals(NetworkUtils.numericToInetAddress("::1"), ipv6Loopback.getAddress());
+        assertEquals(128, ipv6Loopback.getNetworkPrefixLength());
+
+        // Null addresses are rejected.
+        try {
+            address = new LinkAddress(null, 24);
+            fail("Null InetAddress should cause IllegalArgumentException");
+        } catch(IllegalArgumentException expected) {}
+
+        try {
+            address = new LinkAddress((String) null);
+            fail("Null string should cause IllegalArgumentException");
+        } catch(IllegalArgumentException expected) {}
+
+        try {
+            address = new LinkAddress((InterfaceAddress) null);
+            fail("Null string should cause NullPointerException");
+        } catch(NullPointerException expected) {}
+
+        // Invalid prefix lengths are rejected.
+        try {
+            address = new LinkAddress(V4 + "/-1");
+            fail("Negative IPv4 prefix length should cause IllegalArgumentException");
+        } catch(IllegalArgumentException expected) {}
+
+        try {
+            address = new LinkAddress(V6 + "/-1");
+            fail("Negative IPv6 prefix length should cause IllegalArgumentException");
+        } catch(IllegalArgumentException expected) {}
+
+        try {
+            address = new LinkAddress(V4 + "/33");
+            fail("/35 IPv4 prefix length should cause IllegalArgumentException");
+        } catch(IllegalArgumentException expected) {}
+
+        try {
+            address = new LinkAddress(V6 + "/129");
+            fail("/129 IPv6 prefix length should cause IllegalArgumentException");
+        } catch(IllegalArgumentException expected) {}
+    }
+
+    private void assertLinkAddressesEqual(LinkAddress l1, LinkAddress l2) {
+        assertTrue(l1 + " unexpectedly not equal to " + l2, l1.equals(l2));
+        assertTrue(l2 + " unexpectedly not equal to " + l1, l2.equals(l1));
+        assertEquals(l1.hashCode(), l2.hashCode());
+    }
+
+    private void assertLinkAddressesNotEqual(LinkAddress l1, LinkAddress l2) {
+        assertFalse(l1 + " unexpectedly equal to " + l2, l1.equals(l2));
+        assertFalse(l2 + " unexpectedly equal to " + l1, l2.equals(l1));
+    }
+
+    public void testEquals() {
+        LinkAddress l1, l2;
+
+        l1 = new LinkAddress("2001:db8::1/64");
+        l2 = new LinkAddress("2001:db8::1/64");
+        assertLinkAddressesEqual(l1, l2);
+
+        l2 = new LinkAddress("2001:db8::1/65");
+        assertLinkAddressesNotEqual(l1, l2);
+        l2 = new LinkAddress("2001:db8::2/64");
+        assertLinkAddressesNotEqual(l1, l2);
+
+        l1 = new LinkAddress("192.0.2.1/24");
+        l2 = new LinkAddress("192.0.2.1/24");
+        assertLinkAddressesEqual(l1, l2);
+
+        l2 = new LinkAddress("192.0.2.1/23");
+        assertLinkAddressesNotEqual(l1, l2);
+        l2 = new LinkAddress("192.0.2.2/24");
+        assertLinkAddressesNotEqual(l1, l2);
+
+        // Addresses with the same start or end bytes aren't equal between families.
+        l1 = new LinkAddress("255.255.255.255/24");
+        l2 = new LinkAddress("ffff:ffff::/24");
+        assertLinkAddressesNotEqual(l1, l2);
+        l2 = new LinkAddress("::ffff:ffff/24");
+        assertLinkAddressesNotEqual(l1, l2);
+
+        // Because we use InetAddress, an IPv4 address is equal to its IPv4-mapped address.
+        // TODO: Investigate fixing this.
+        String addressString = V4 + "/24";
+        l1 = new LinkAddress(addressString);
+        l2 = new LinkAddress("::ffff:" + addressString);
+        assertLinkAddressesEqual(l1, l2);
+    }
+
+    public void testHashCode() {
+        LinkAddress l;
+
+        l = new LinkAddress(V4_ADDRESS, 23);
+        assertEquals(-982787, l.hashCode());
+
+        l = new LinkAddress(V4_ADDRESS, 27);
+        assertEquals(-982743, l.hashCode());
+
+        l = new LinkAddress(V6_ADDRESS, 64);
+        assertEquals(1076522926, l.hashCode());
+
+        l = new LinkAddress(V6_ADDRESS, 128);
+        assertEquals(1076523630, l.hashCode());
+    }
+
+    private LinkAddress passThroughParcel(LinkAddress l) {
+        Parcel p = Parcel.obtain();
+        LinkAddress l2 = null;
+        try {
+            l.writeToParcel(p, 0);
+            p.setDataPosition(0);
+            l2 = LinkAddress.CREATOR.createFromParcel(p);
+        } finally {
+            p.recycle();
+        }
+        assertNotNull(l2);
+        return l2;
+    }
+
+    private void assertParcelingIsLossless(LinkAddress l) {
+      LinkAddress l2 = passThroughParcel(l);
+      assertEquals(l, l2);
+    }
+
+    public void testParceling() {
+        LinkAddress l;
+
+        l = new LinkAddress(V6_ADDRESS, 64);
+        assertParcelingIsLossless(l);
+
+        l = new LinkAddress(V4 + "/28");
+        assertParcelingIsLossless(l);
+    }
+}