/*
 * Copyright (C) 2008 The Guava Authors
 *
 * 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.google.common.net;

import com.google.common.testing.NullPointerTester;

import junit.framework.TestCase;

import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * Tests for {@link InetAddresses}.
 *
 * @author Erik Kline
 */
public class InetAddressesTest extends TestCase {

  public void testNulls() {
    NullPointerTester tester = new NullPointerTester();

    tester.testAllPublicStaticMethods(InetAddresses.class);
  }

  public void testForStringBogusInput() {
    String[] bogusInputs = {
        "",
        "016.016.016.016",
        "016.016.016",
        "016.016",
        "016",
        "000.000.000.000",
        "000",
        "0x0a.0x0a.0x0a.0x0a",
        "0x0a.0x0a.0x0a",
        "0x0a.0x0a",
        "0x0a",
        "42.42.42.42.42",
        "42.42.42",
        "42.42",
        "42",
        "42..42.42",
        "42..42.42.42",
        "42.42.42.42.",
        "42.42.42.42...",
        ".42.42.42.42",
        "...42.42.42.42",
        "42.42.42.-0",
        "42.42.42.+0",
        ".",
        "...",
        "bogus",
        "bogus.com",
        "192.168.0.1.com",
        "12345.67899.-54321.-98765",
        "257.0.0.0",
        "42.42.42.-42",
        "3ffe::1.net",
        "3ffe::1::1",
        "1::2::3::4:5",
        "::7:6:5:4:3:2:",  // should end with ":0"
        ":6:5:4:3:2:1::",  // should begin with "0:"
        "2001::db:::1",
        "FEDC:9878",
        "+1.+2.+3.4",
        "1.2.3.4e0",
        "::7:6:5:4:3:2:1:0",  // too many parts
        "7:6:5:4:3:2:1:0::",  // too many parts
        "9:8:7:6:5:4:3::2:1",  // too many parts
        "0:1:2:3::4:5:6:7",  // :: must remove at least one 0.
        "3ffe:0:0:0:0:0:0:0:1",  // too many parts (9 instead of 8)
        "3ffe::10000",  // hextet exceeds 16 bits
        "3ffe::goog",
        "3ffe::-0",
        "3ffe::+0",
        "3ffe::-1",
        ":",
        ":::",
        "::1.2.3",
        "::1.2.3.4.5",
        "::1.2.3.4:",
        "1.2.3.4::",
        "2001:db8::1:",
        ":2001:db8::1",
        ":1:2:3:4:5:6:7",
        "1:2:3:4:5:6:7:",
        ":1:2:3:4:5:6:"
    };

    for (int i = 0; i < bogusInputs.length; i++) {
      try {
        InetAddresses.forString(bogusInputs[i]);
        fail("IllegalArgumentException expected for '" + bogusInputs[i] + "'");
      } catch (IllegalArgumentException expected) {
        // expected behavior
      }
      assertFalse(InetAddresses.isInetAddress(bogusInputs[i]));
    }
  }

  public void test3ff31() {
    try {
      InetAddresses.forString("3ffe:::1");
      fail("IllegalArgumentException expected");
    } catch (IllegalArgumentException expected) {
      // expected behavior
    }
    assertFalse(InetAddresses.isInetAddress("016.016.016.016"));
  }

  public void testForStringIPv4Input() throws UnknownHostException {
    String ipStr = "192.168.0.1";
    InetAddress ipv4Addr = null;
    // Shouldn't hit DNS, because it's an IP string literal.
    ipv4Addr = InetAddress.getByName(ipStr);
    assertEquals(ipv4Addr, InetAddresses.forString(ipStr));
    assertTrue(InetAddresses.isInetAddress(ipStr));
  }

  public void testForStringIPv6Input() throws UnknownHostException {
    String ipStr = "3ffe::1";
    InetAddress ipv6Addr = null;
    // Shouldn't hit DNS, because it's an IP string literal.
    ipv6Addr = InetAddress.getByName(ipStr);
    assertEquals(ipv6Addr, InetAddresses.forString(ipStr));
    assertTrue(InetAddresses.isInetAddress(ipStr));
  }

  public void testForStringIPv6EightColons() throws UnknownHostException {
    String[] eightColons = {
      "::7:6:5:4:3:2:1",
      "::7:6:5:4:3:2:0",
      "7:6:5:4:3:2:1::",
      "0:6:5:4:3:2:1::",
    };

    for (int i = 0; i < eightColons.length; i++) {
      InetAddress ipv6Addr = null;
      // Shouldn't hit DNS, because it's an IP string literal.
      ipv6Addr = InetAddress.getByName(eightColons[i]);
      assertEquals(ipv6Addr, InetAddresses.forString(eightColons[i]));
      assertTrue(InetAddresses.isInetAddress(eightColons[i]));
    }
  }

  public void testConvertDottedQuadToHex() throws UnknownHostException {
    String[] ipStrings = {"7::0.128.0.127", "7::0.128.0.128",
        "7::128.128.0.127", "7::0.128.128.127"};

    for (String ipString : ipStrings) {
      // Shouldn't hit DNS, because it's an IP string literal.
      InetAddress ipv6Addr = InetAddress.getByName(ipString);
      assertEquals(ipv6Addr, InetAddresses.forString(ipString));
      assertTrue(InetAddresses.isInetAddress(ipString));
    }
  }

  public void testToAddrStringIPv4() {
    // Don't need to test IPv4 much; it just calls getHostAddress().
    assertEquals("1.2.3.4",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("1.2.3.4")));
  }

  public void testToAddrStringIPv6() {
    assertEquals("1:2:3:4:5:6:7:8",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("1:2:3:4:5:6:7:8")));
    assertEquals("2001:0:0:4::8",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("2001:0:0:4:0:0:0:8")));
    assertEquals("2001::4:5:6:7:8",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("2001:0:0:4:5:6:7:8")));
    assertEquals("2001:0:3:4:5:6:7:8",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("2001:0:3:4:5:6:7:8")));
    assertEquals("0:0:3::ffff",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("0:0:3:0:0:0:0:ffff")));
    assertEquals("::4:0:0:0:ffff",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("0:0:0:4:0:0:0:ffff")));
    assertEquals("::5:0:0:ffff",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("0:0:0:0:5:0:0:ffff")));
    assertEquals("1::4:0:0:7:8",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("1:0:0:4:0:0:7:8")));
    assertEquals("::",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("0:0:0:0:0:0:0:0")));
    assertEquals("::1",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("0:0:0:0:0:0:0:1")));
    assertEquals("2001:658:22a:cafe::",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("2001:0658:022a:cafe::")));
    assertEquals("::102:304",
                 InetAddresses.toAddrString(
                     InetAddresses.forString("::1.2.3.4")));
  }

  public void testToUriStringIPv4() {
    String ipStr = "1.2.3.4";
    InetAddress ip = InetAddresses.forString(ipStr);
    assertEquals("1.2.3.4", InetAddresses.toUriString(ip));
  }

  public void testToUriStringIPv6() {
    // Unfortunately the InetAddress.toString() method for IPv6 addresses
    // does not collapse contiguous shorts of zeroes with the :: abbreviation.
    String ipStr = "3ffe::1";
    InetAddress ip = InetAddresses.forString(ipStr);
    assertEquals("[3ffe::1]", InetAddresses.toUriString(ip));
  }

  public void testForUriStringIPv4() {
    Inet4Address expected = (Inet4Address) InetAddresses.forString("192.168.1.1");
    assertEquals(expected, InetAddresses.forUriString("192.168.1.1"));
  }

  public void testForUriStringIPv6() {
    Inet6Address expected = (Inet6Address) InetAddresses.forString("3ffe:0:0:0:0:0:0:1");
    assertEquals(expected, InetAddresses.forUriString("[3ffe:0:0:0:0:0:0:1]"));
  }

  public void testForUriStringIPv4Mapped() {
    Inet4Address expected = (Inet4Address) InetAddresses.forString("192.0.2.1");
    assertEquals(expected, InetAddresses.forUriString("[::ffff:192.0.2.1]"));
  }

  public void testIsUriInetAddress() {
    assertTrue(InetAddresses.isUriInetAddress("192.168.1.1"));
    assertTrue(InetAddresses.isUriInetAddress("[3ffe:0:0:0:0:0:0:1]"));
    assertTrue(InetAddresses.isUriInetAddress("[::ffff:192.0.2.1]"));

    assertFalse(InetAddresses.isUriInetAddress("[192.168.1.1"));
    assertFalse(InetAddresses.isUriInetAddress("192.168.1.1]"));
    assertFalse(InetAddresses.isUriInetAddress(""));
    assertFalse(InetAddresses.isUriInetAddress("192.168.999.888"));
    assertFalse(InetAddresses.isUriInetAddress("www.google.com"));
    assertFalse(InetAddresses.isUriInetAddress("1:2e"));
    assertFalse(InetAddresses.isUriInetAddress("[3ffe:0:0:0:0:0:0:1"));
    assertFalse(InetAddresses.isUriInetAddress("3ffe:0:0:0:0:0:0:1]"));
    assertFalse(InetAddresses.isUriInetAddress("3ffe:0:0:0:0:0:0:1"));
    assertFalse(InetAddresses.isUriInetAddress("::ffff:192.0.2.1"));
  }

  public void testForUriStringBad() {
    try {
      InetAddresses.forUriString("");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("192.168.999.888");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("www.google.com");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("[1:2e]");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("[192.168.1.1]");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("192.168.1.1]");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("[192.168.1.1");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("[3ffe:0:0:0:0:0:0:1");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("3ffe:0:0:0:0:0:0:1]");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("3ffe:0:0:0:0:0:0:1");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }

    try {
      InetAddresses.forUriString("::ffff:192.0.2.1");
      fail("expected IllegalArgumentException");  // COV_NF_LINE
    } catch (IllegalArgumentException e) {
      // expected
    }
  }

  public void testCompatIPv4Addresses() {
    String[] nonCompatAddresses = {
        "3ffe::1",
        "::",
        "::1",
    };

    for (int i = 0; i < nonCompatAddresses.length; i++) {
      InetAddress ip = InetAddresses.forString(nonCompatAddresses[i]);
      assertFalse(InetAddresses.isCompatIPv4Address((Inet6Address) ip));
      try {
        InetAddresses.getCompatIPv4Address((Inet6Address) ip);
        fail("IllegalArgumentException expected for '" +
             nonCompatAddresses[i] + "'");
      } catch (IllegalArgumentException expected) {
        // expected behavior
      }
    }

    String[] validCompatAddresses = {
        "::1.2.3.4",
        "::102:304",
    };
    String compatStr = "1.2.3.4";
    InetAddress compat = InetAddresses.forString(compatStr);

    for (int i = 0; i < validCompatAddresses.length; i++) {
      InetAddress ip = InetAddresses.forString(validCompatAddresses[i]);
      assertTrue("checking '" + validCompatAddresses[i] + "'", ip instanceof Inet6Address);
      assertTrue("checking '" + validCompatAddresses[i] + "'",
          InetAddresses.isCompatIPv4Address((Inet6Address) ip));
      assertEquals("checking '" + validCompatAddresses[i] + "'", compat,
                   InetAddresses.getCompatIPv4Address((Inet6Address) ip));
    }
  }

  public void testMappedIPv4Addresses() throws UnknownHostException {
    /*
     * Verify that it is not possible to instantiate an Inet6Address
     * from an "IPv4 mapped" IPv6 address.  Our String-based method can
     * at least identify them, however.
     */
    String mappedStr = "::ffff:192.168.0.1";
    assertTrue(InetAddresses.isMappedIPv4Address(mappedStr));
    InetAddress mapped = InetAddresses.forString(mappedStr);
    assertFalse(mapped instanceof Inet6Address);
    assertEquals(InetAddress.getByName("192.168.0.1"), mapped);

    // check upper case
    mappedStr = "::FFFF:192.168.0.1";
    assertTrue(InetAddresses.isMappedIPv4Address(mappedStr));
    mapped = InetAddresses.forString(mappedStr);
    assertFalse(mapped instanceof Inet6Address);
    assertEquals(InetAddress.getByName("192.168.0.1"), mapped);

    mappedStr = "0:00:000:0000:0:ffff:1.2.3.4";
    assertTrue(InetAddresses.isMappedIPv4Address(mappedStr));
    mapped = InetAddresses.forString(mappedStr);
    assertFalse(mapped instanceof Inet6Address);
    assertEquals(InetAddress.getByName("1.2.3.4"), mapped);

    mappedStr = "::ffff:0102:0304";
    assertTrue(InetAddresses.isMappedIPv4Address(mappedStr));
    mapped = InetAddresses.forString(mappedStr);
    assertFalse(mapped instanceof Inet6Address);
    assertEquals(InetAddress.getByName("1.2.3.4"), mapped);

    assertFalse(InetAddresses.isMappedIPv4Address("::"));
    assertFalse(InetAddresses.isMappedIPv4Address("::ffff"));
    assertFalse(InetAddresses.isMappedIPv4Address("::ffff:0"));
    assertFalse(InetAddresses.isMappedIPv4Address("::fffe:0:0"));
    assertFalse(InetAddresses.isMappedIPv4Address("::1:ffff:0:0"));
    assertFalse(InetAddresses.isMappedIPv4Address("foo"));
    assertFalse(InetAddresses.isMappedIPv4Address("192.0.2.1"));
  }

  public void test6to4Addresses() {
    String[] non6to4Addresses = {
        "::1.2.3.4",
        "3ffe::1",
        "::",
        "::1",
    };

    for (int i = 0; i < non6to4Addresses.length; i++) {
      InetAddress ip = InetAddresses.forString(non6to4Addresses[i]);
      assertFalse(InetAddresses.is6to4Address((Inet6Address) ip));
      try {
        InetAddresses.get6to4IPv4Address(
            (Inet6Address) ip);
        fail("IllegalArgumentException expected for '" +
             non6to4Addresses[i] + "'");
      } catch (IllegalArgumentException expected) {
        // expected behavior
      }
    }

    String valid6to4Address = "2002:0102:0304::1";
    String ipv4Str = "1.2.3.4";

    InetAddress ipv4 = InetAddresses.forString(ipv4Str);
    InetAddress ip = InetAddresses.forString(valid6to4Address);
    assertTrue(InetAddresses.is6to4Address((Inet6Address) ip));
    assertEquals(ipv4, InetAddresses.get6to4IPv4Address((Inet6Address) ip));
  }

  public void testTeredoAddresses() {
    String[] nonTeredoAddresses = {
        "::1.2.3.4",
        "3ffe::1",
        "::",
        "::1",
    };

    for (int i = 0; i < nonTeredoAddresses.length; i++) {
      InetAddress ip = InetAddresses.forString(nonTeredoAddresses[i]);
      assertFalse(InetAddresses.isTeredoAddress((Inet6Address) ip));
      try {
        InetAddresses.getTeredoInfo((Inet6Address) ip);
        fail("IllegalArgumentException expected for '" +
             nonTeredoAddresses[i] + "'");
      } catch (IllegalArgumentException expected) {
        // expected behavior
      }
    }

    String validTeredoAddress = "2001:0000:4136:e378:8000:63bf:3fff:fdd2";
    String serverStr = "65.54.227.120";
    String clientStr = "192.0.2.45";
    int port = 40000;
    int flags = 0x8000;

    InetAddress ip = InetAddresses.forString(validTeredoAddress);
    assertTrue(InetAddresses.isTeredoAddress((Inet6Address) ip));
    InetAddresses.TeredoInfo teredo =
        InetAddresses.getTeredoInfo((Inet6Address) ip);

    InetAddress server = InetAddresses.forString(serverStr);
    assertEquals(server, teredo.getServer());

    InetAddress client = InetAddresses.forString(clientStr);
    assertEquals(client, teredo.getClient());

    assertEquals(port, teredo.getPort());
    assertEquals(flags, teredo.getFlags());
  }

  public void testTeredoAddress_nullServer() {
    InetAddresses.TeredoInfo info = new InetAddresses.TeredoInfo(null, null, 80, 1000);
    assertEquals(InetAddresses.forString("0.0.0.0"), info.getServer());
    assertEquals(InetAddresses.forString("0.0.0.0"), info.getClient());
    assertEquals(80, info.getPort());
    assertEquals(1000, info.getFlags());
  }

  public void testIsatapAddresses() {
    InetAddress ipv4 = InetAddresses.forString("1.2.3.4");
    String[] validIsatapAddresses = {
        "2001:db8::5efe:102:304",
        "2001:db8::100:5efe:102:304",  // Private Multicast? Not likely.
        "2001:db8::200:5efe:102:304",
        "2001:db8::300:5efe:102:304"   // Public Multicast? Also unlikely.
    };
    String[] nonIsatapAddresses = {
        "::1.2.3.4",
        "3ffe::1",
        "::",
        "::1",
        "2001:db8::0040:5efe:102:304",
        "2001:db8::5ffe:102:304",
        "2001:db8::5eff:102:304",
        "2001:0:102:203:200:5efe:506:708",  // Teredo address; not ISATAP
    };

    for (int i = 0; i < validIsatapAddresses.length; i++) {
      InetAddress ip = InetAddresses.forString(validIsatapAddresses[i]);
      assertTrue(InetAddresses.isIsatapAddress((Inet6Address) ip));
      assertEquals("checking '" + validIsatapAddresses[i] + "'", ipv4,
                   InetAddresses.getIsatapIPv4Address((Inet6Address) ip));
    }
    for (int i = 0; i < nonIsatapAddresses.length; i++) {
      InetAddress ip = InetAddresses.forString(nonIsatapAddresses[i]);
      assertFalse(InetAddresses.isIsatapAddress((Inet6Address) ip));
      try {
        InetAddresses.getIsatapIPv4Address((Inet6Address) ip);
        fail("IllegalArgumentException expected for '" +
             nonIsatapAddresses[i] + "'");
      } catch (IllegalArgumentException expected) {
        // expected behavior
      }
    }
  }

  public void testGetEmbeddedIPv4ClientAddress() {
    Inet6Address testIp;

    // Test regular global unicast address.
    testIp = (Inet6Address) InetAddresses.forString("2001:db8::1");
    assertFalse(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));

    // Test ISATAP address.
    testIp = (Inet6Address) InetAddresses.forString("2001:db8::5efe:102:304");
    assertFalse(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));

    // Test compat address.
    testIp = (Inet6Address) InetAddresses.forString("::1.2.3.4");
    assertTrue(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));
    InetAddress ipv4 = InetAddresses.forString("1.2.3.4");
    assertEquals(ipv4, InetAddresses.getEmbeddedIPv4ClientAddress(testIp));

    // Test 6to4 address.
    testIp = (Inet6Address) InetAddresses.forString("2002:0102:0304::1");
    assertTrue(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));
    ipv4 = InetAddresses.forString("1.2.3.4");
    assertEquals(ipv4, InetAddresses.getEmbeddedIPv4ClientAddress(testIp));

    // Test Teredo address.
    testIp = (Inet6Address) InetAddresses.forString(
        "2001:0000:4136:e378:8000:63bf:3fff:fdd2");
    assertTrue(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));
    ipv4 = InetAddresses.forString("192.0.2.45");
    assertEquals(ipv4, InetAddresses.getEmbeddedIPv4ClientAddress(testIp));
  }

  public void testGetCoercedIPv4Address() {
    // Check that a coerced IPv4 address is unaltered.
    InetAddress localHost4 = InetAddresses.forString("127.0.0.1");
    assertEquals(localHost4,
                 InetAddresses.getCoercedIPv4Address(localHost4));

    // ::1 special case
    assertEquals(localHost4,
                 InetAddresses.getCoercedIPv4Address(
                     InetAddresses.forString("::1")));

    // :: special case
    assertEquals(InetAddresses.forString("0.0.0.0"),
                 InetAddresses.getCoercedIPv4Address(
                     InetAddresses.forString("::")));

    // test compat address (should be hashed)
    assertTrue(InetAddresses.forString("1.2.3.4") !=
               InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString("::1.2.3.4")));

    // test 6to4 address (should be hashed)
    assertTrue(InetAddresses.forString("1.2.3.4") !=
               InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString("2002:0102:0304::1")));

    // 2 6to4 addresses differing in the embedded IPv4 address should
    // hash to the different values.
    assertTrue(InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString("2002:0102:0304::1")) !=
               InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString("2002:0506:0708::1")));

    // 2 6to4 addresses NOT differing in the embedded IPv4 address should
    // hash to the same value.
    assertTrue(InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString("2002:0102:0304::1")) !=
               InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString("2002:0102:0304::2")));

    // test Teredo address (should be hashed)
    assertTrue(InetAddresses.forString("192.0.2.45") !=
               InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString(
                       "2001:0000:4136:e378:8000:63bf:3fff:fdd2")));

    // 2 Teredo addresses differing in the embedded IPv4 address should
    // hash to the different values.
    assertTrue(InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString(
                       "2001:0000:4136:e378:8000:63bf:3fff:fdd2")) !=
               InetAddresses.getCoercedIPv4Address(
                   InetAddresses.forString(
                       "2001:0000:4136:e379:8000:63bf:3fff:fdd2")));

    // 2 Teredo addresses NOT differing in the embedded IPv4 address should
    // hash to the same value.
    assertEquals(InetAddresses.getCoercedIPv4Address(
                     InetAddresses.forString(
                         "2001:0000:4136:e378:8000:63bf:3fff:fdd2")),
                 InetAddresses.getCoercedIPv4Address(
                     InetAddresses.forString(
                         "2001:0000:4136:e378:9000:63bf:3fff:fdd2")));

    // Test that an address hashes in to the 224.0.0.0/3 number-space.
    InetAddress coerced = InetAddresses.getCoercedIPv4Address(
                              InetAddresses.forString("2001:4860::1"));
    assertTrue(0xe0000000 <= InetAddresses.coerceToInteger(coerced));
    assertTrue(InetAddresses.coerceToInteger(coerced) <= 0xfffffffe);
  }

  public void testToInteger() {
    InetAddress ipv4Addr = InetAddresses.forString("127.0.0.1");
    assertEquals(0x7f000001, InetAddresses.coerceToInteger(ipv4Addr));
  }

  public void testFromInteger() {
    assertEquals(InetAddresses.fromInteger(0x7f000001),
                 InetAddresses.forString("127.0.0.1"));
  }

  public void testFromLittleEndianByteArray() throws UnknownHostException {
    assertEquals(
        InetAddresses.fromLittleEndianByteArray(new byte[] {1, 2, 3, 4}),
        InetAddress.getByAddress(new byte[] {4, 3, 2, 1}));

    assertEquals(
        InetAddresses.fromLittleEndianByteArray(
            new byte[] {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}),
        InetAddress.getByAddress(
            new byte[] {16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1}));

    try {
      InetAddresses.fromLittleEndianByteArray(new byte[3]);
      fail("expected exception");
    } catch (UnknownHostException expected) {
      // success
    }
  }

  public void testIsMaximum() throws UnknownHostException {
    InetAddress address = InetAddress.getByName("255.255.255.254");
    assertFalse(InetAddresses.isMaximum(address));

    address = InetAddress.getByName("255.255.255.255");
    assertTrue(InetAddresses.isMaximum(address));

    address = InetAddress.getByName("ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffe");
    assertFalse(InetAddresses.isMaximum(address));

    address = InetAddress.getByName("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff");
    assertTrue(InetAddresses.isMaximum(address));
  }

  public void testIncrementIPv4() throws UnknownHostException {
    InetAddress address_66_0 = InetAddress.getByName("172.24.66.0");
    InetAddress address_66_255 = InetAddress.getByName("172.24.66.255");
    InetAddress address_67_0 = InetAddress.getByName("172.24.67.0");

    InetAddress address = address_66_0;
    for (int i = 0; i < 255; i++) {
      address = InetAddresses.increment(address);
    }
    assertEquals(address_66_255, address);

    address = InetAddresses.increment(address);
    assertEquals(address_67_0, address);

    InetAddress address_ffffff = InetAddress.getByName("255.255.255.255");
    address = address_ffffff;
    try {
      address = InetAddresses.increment(address);
      fail();
    } catch (IllegalArgumentException expected) {}
  }

  public void testIncrementIPv6() throws UnknownHostException {
    InetAddress addressV6_66_0 = InetAddress.getByName("2001:db8::6600");
    InetAddress addressV6_66_ff = InetAddress.getByName("2001:db8::66ff");
    InetAddress addressV6_67_0 = InetAddress.getByName("2001:db8::6700");

    InetAddress address = addressV6_66_0;
    for (int i = 0; i < 255; i++) {
      address = InetAddresses.increment(address);
    }
    assertEquals(addressV6_66_ff, address);

    address = InetAddresses.increment(address);
    assertEquals(addressV6_67_0, address);

    InetAddress addressV6_ffffff =
        InetAddress.getByName("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff");
    address = addressV6_ffffff;
    try {
      address = InetAddresses.increment(address);
      fail();
    } catch (IllegalArgumentException expected) {}
  }

  public void testDecrementIPv4() throws UnknownHostException {
    InetAddress address660 = InetAddress.getByName("172.24.66.0");
    InetAddress address66255 = InetAddress.getByName("172.24.66.255");
    InetAddress address670 = InetAddress.getByName("172.24.67.0");

    InetAddress address = address670;
    address = InetAddresses.decrement(address);

    assertEquals(address66255, address);

    for (int i = 0; i < 255; i++) {
      address = InetAddresses.decrement(address);
    }
    assertEquals(address660, address);

    InetAddress address0000 = InetAddress.getByName("0.0.0.0");
    address = address0000;
    try {
      address = InetAddresses.decrement(address);
      fail();
    } catch (IllegalArgumentException expected) {}
  }

  public void testDecrementIPv6() throws UnknownHostException {
    InetAddress addressV6660 = InetAddress.getByName("2001:db8::6600");
    InetAddress addressV666ff = InetAddress.getByName("2001:db8::66ff");
    InetAddress addressV6670 = InetAddress.getByName("2001:db8::6700");

    InetAddress address = addressV6670;
    address = InetAddresses.decrement(address);

    assertEquals(addressV666ff, address);

    for (int i = 0; i < 255; i++) {
      address = InetAddresses.decrement(address);
    }
    assertEquals(addressV6660, address);

    InetAddress addressV6000000 =
        InetAddress.getByName("0:0:0:0:0:0:0:0");
    address = addressV6000000;
    try {
      address = InetAddresses.decrement(address);
      fail();
    } catch (IllegalArgumentException expected) {}
  }
}