Merge "Add utils to convert Inet4Address <-> int"

am: 2587292cd1

Change-Id: I347d23f4682eca623e3b10f72bc9000b1c5954a3

core/java/android/net/NetworkUtils.java

@@ -126,51 +126,122 @@ public class NetworkUtils {
     public native static boolean queryUserAccess(int uid, int netId);
 
     /**
-     * Convert a IPv4 address from an integer to an InetAddress.
+     * @see #intToInet4AddressHTL(int)
-     * @param hostAddress an int corresponding to the IPv4 address in network byte order
+     * @deprecated Use either {@link #intToInet4AddressHTH(int)}
+     *             or {@link #intToInet4AddressHTL(int)}
      */
+    @Deprecated
     public static InetAddress intToInetAddress(int hostAddress) {
-        byte[] addressBytes = { (byte)(0xff & hostAddress),
+        return intToInet4AddressHTL(hostAddress);
-                                (byte)(0xff & (hostAddress >> 8)),
+    }
-                                (byte)(0xff & (hostAddress >> 16)),
+
-                                (byte)(0xff & (hostAddress >> 24)) };
+    /**
+     * Convert a IPv4 address from an integer to an InetAddress (0x04030201 -> 1.2.3.4)
+     *
+     * <p>This method uses the higher-order int bytes as the lower-order IPv4 address bytes,
+     * which is an unusual convention. Consider {@link #intToInet4AddressHTH(int)} instead.
+     * @param hostAddress an int coding for an IPv4 address, where higher-order int byte is
+     *                    lower-order IPv4 address byte
+     */
+    public static InetAddress intToInet4AddressHTL(int hostAddress) {
+        return intToInet4AddressHTH(Integer.reverseBytes(hostAddress));
+    }
+
+    /**
+     * Convert a IPv4 address from an integer to an InetAddress (0x01020304 -> 1.2.3.4)
+     * @param hostAddress an int coding for an IPv4 address
+     */
+    public static InetAddress intToInet4AddressHTH(int hostAddress) {
+        byte[] addressBytes = { (byte) (0xff & (hostAddress >> 24)),
+                (byte) (0xff & (hostAddress >> 16)),
+                (byte) (0xff & (hostAddress >> 8)),
+                (byte) (0xff & hostAddress) };
 
         try {
-           return InetAddress.getByAddress(addressBytes);
+            return InetAddress.getByAddress(addressBytes);
         } catch (UnknownHostException e) {
-           throw new AssertionError();
+            throw new AssertionError();
         }
     }
 
     /**
-     * Convert a IPv4 address from an InetAddress to an integer
+     * @see #inet4AddressToIntHTL(Inet4Address)
-     * @param inetAddr is an InetAddress corresponding to the IPv4 address
+     * @deprecated Use either {@link #inet4AddressToIntHTH(Inet4Address)}
-     * @return the IP address as an integer in network byte order
+     *             or {@link #inet4AddressToIntHTL(Inet4Address)}
      */
+    @Deprecated
     public static int inetAddressToInt(Inet4Address inetAddr)
             throws IllegalArgumentException {
-        byte [] addr = inetAddr.getAddress();
+        return inet4AddressToIntHTL(inetAddr);
-        return ((addr[3] & 0xff) << 24) | ((addr[2] & 0xff) << 16) |
-                ((addr[1] & 0xff) << 8) | (addr[0] & 0xff);
     }
 
     /**
-     * Convert a network prefix length to an IPv4 netmask integer
+     * Convert an IPv4 address from an InetAddress to an integer (1.2.3.4 -> 0x01020304)
-     * @param prefixLength
+     *
-     * @return the IPv4 netmask as an integer in network byte order
+     * <p>This conversion can help order IP addresses: considering the ordering
+     * 192.0.2.1 < 192.0.2.2 < ..., resulting ints will follow that ordering if read as unsigned
+     * integers with {@link Integer#toUnsignedLong}.
+     * @param inetAddr is an InetAddress corresponding to the IPv4 address
+     * @return the IP address as integer
      */
+    public static int inet4AddressToIntHTH(Inet4Address inetAddr)
+            throws IllegalArgumentException {
+        byte [] addr = inetAddr.getAddress();
+        return ((addr[0] & 0xff) << 24) | ((addr[1] & 0xff) << 16)
+                | ((addr[2] & 0xff) << 8) | (addr[3] & 0xff);
+    }
+
+    /**
+     * Convert a IPv4 address from an InetAddress to an integer (1.2.3.4 -> 0x04030201)
+     *
+     * <p>This method stores the higher-order IPv4 address bytes in the lower-order int bytes,
+     * which is an unusual convention. Consider {@link #inet4AddressToIntHTH(Inet4Address)} instead.
+     * @param inetAddr is an InetAddress corresponding to the IPv4 address
+     * @return the IP address as integer
+     */
+    public static int inet4AddressToIntHTL(Inet4Address inetAddr) {
+        return Integer.reverseBytes(inet4AddressToIntHTH(inetAddr));
+    }
+
+    /**
+     * @see #prefixLengthToV4NetmaskIntHTL(int)
+     * @deprecated Use either {@link #prefixLengthToV4NetmaskIntHTH(int)}
+     *             or {@link #prefixLengthToV4NetmaskIntHTL(int)}
+     */
+    @Deprecated
     public static int prefixLengthToNetmaskInt(int prefixLength)
             throws IllegalArgumentException {
+        return prefixLengthToV4NetmaskIntHTL(prefixLength);
+    }
+
+    /**
+     * Convert a network prefix length to an IPv4 netmask integer (prefixLength 17 -> 0xffff8000)
+     * @return the IPv4 netmask as an integer
+     */
+    public static int prefixLengthToV4NetmaskIntHTH(int prefixLength)
+            throws IllegalArgumentException {
         if (prefixLength < 0 || prefixLength > 32) {
             throw new IllegalArgumentException("Invalid prefix length (0 <= prefix <= 32)");
         }
-        int value = 0xffffffff << (32 - prefixLength);
+        // (int)a << b is equivalent to a << (b & 0x1f): can't shift by 32 (-1 << 32 == -1)
-        return Integer.reverseBytes(value);
+        return prefixLength == 0 ? 0 : 0xffffffff << (32 - prefixLength);
+    }
+
+    /**
+     * Convert a network prefix length to an IPv4 netmask integer (prefixLength 17 -> 0x0080ffff).
+     *
+     * <p>This method stores the higher-order IPv4 address bytes in the lower-order int bytes,
+     * which is an unusual convention. Consider {@link #prefixLengthToV4NetmaskIntHTH(int)} instead.
+     * @return the IPv4 netmask as an integer
+     */
+    public static int prefixLengthToV4NetmaskIntHTL(int prefixLength)
+            throws IllegalArgumentException {
+        return Integer.reverseBytes(prefixLengthToV4NetmaskIntHTH(prefixLength));
     }
 
     /**
      * Convert a IPv4 netmask integer to a prefix length
-     * @param netmask as an integer in network byte order
+     * @param netmask as an integer (0xff000000 for a /8 subnet)
      * @return the network prefix length
      */
     public static int netmaskIntToPrefixLength(int netmask) {

tests/net/java/android/net/NetworkUtilsTest.java

@@ -16,17 +16,32 @@
 
 package android.net;
 
-import android.net.NetworkUtils;
+import static android.net.NetworkUtils.getImplicitNetmask;
-import android.test.suitebuilder.annotation.SmallTest;
+import static android.net.NetworkUtils.inet4AddressToIntHTH;
+import static android.net.NetworkUtils.inet4AddressToIntHTL;
+import static android.net.NetworkUtils.intToInet4AddressHTH;
+import static android.net.NetworkUtils.intToInet4AddressHTL;
+import static android.net.NetworkUtils.netmaskToPrefixLength;
+import static android.net.NetworkUtils.prefixLengthToV4NetmaskIntHTH;
+import static android.net.NetworkUtils.prefixLengthToV4NetmaskIntHTL;
+
+import static junit.framework.Assert.assertEquals;
+
+import static org.junit.Assert.fail;
+
+import android.support.test.runner.AndroidJUnit4;
 
 import java.math.BigInteger;
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.util.TreeSet;
 
-import junit.framework.TestCase;
+import org.junit.Test;
+import org.junit.runner.RunWith;
 
-public class NetworkUtilsTest extends TestCase {
+@RunWith(AndroidJUnit4.class)
+@android.support.test.filters.SmallTest
+public class NetworkUtilsTest {
 
     private InetAddress Address(String addr) {
         return InetAddress.parseNumericAddress(addr);
@@ -36,41 +51,126 @@ public class NetworkUtilsTest extends TestCase {
         return (Inet4Address) Address(addr);
     }
 
-    @SmallTest
+    @Test
     public void testGetImplicitNetmask() {
-        assertEquals(8, NetworkUtils.getImplicitNetmask(IPv4Address("4.2.2.2")));
+        assertEquals(8, getImplicitNetmask(IPv4Address("4.2.2.2")));
-        assertEquals(8, NetworkUtils.getImplicitNetmask(IPv4Address("10.5.6.7")));
+        assertEquals(8, getImplicitNetmask(IPv4Address("10.5.6.7")));
-        assertEquals(16, NetworkUtils.getImplicitNetmask(IPv4Address("173.194.72.105")));
+        assertEquals(16, getImplicitNetmask(IPv4Address("173.194.72.105")));
-        assertEquals(16, NetworkUtils.getImplicitNetmask(IPv4Address("172.23.68.145")));
+        assertEquals(16, getImplicitNetmask(IPv4Address("172.23.68.145")));
-        assertEquals(24, NetworkUtils.getImplicitNetmask(IPv4Address("192.0.2.1")));
+        assertEquals(24, getImplicitNetmask(IPv4Address("192.0.2.1")));
-        assertEquals(24, NetworkUtils.getImplicitNetmask(IPv4Address("192.168.5.1")));
+        assertEquals(24, getImplicitNetmask(IPv4Address("192.168.5.1")));
-        assertEquals(32, NetworkUtils.getImplicitNetmask(IPv4Address("224.0.0.1")));
+        assertEquals(32, getImplicitNetmask(IPv4Address("224.0.0.1")));
-        assertEquals(32, NetworkUtils.getImplicitNetmask(IPv4Address("255.6.7.8")));
+        assertEquals(32, getImplicitNetmask(IPv4Address("255.6.7.8")));
     }
 
     private void assertInvalidNetworkMask(Inet4Address addr) {
         try {
-            NetworkUtils.netmaskToPrefixLength(addr);
+            netmaskToPrefixLength(addr);
             fail("Invalid netmask " + addr.getHostAddress() + " did not cause exception");
         } catch (IllegalArgumentException expected) {
         }
     }
 
-    @SmallTest
+    @Test
+    public void testInet4AddressToIntHTL() {
+        assertEquals(0, inet4AddressToIntHTL(IPv4Address("0.0.0.0")));
+        assertEquals(0x000080ff, inet4AddressToIntHTL(IPv4Address("255.128.0.0")));
+        assertEquals(0x0080ff0a, inet4AddressToIntHTL(IPv4Address("10.255.128.0")));
+        assertEquals(0x00feff0a, inet4AddressToIntHTL(IPv4Address("10.255.254.0")));
+        assertEquals(0xfeffa8c0, inet4AddressToIntHTL(IPv4Address("192.168.255.254")));
+        assertEquals(0xffffa8c0, inet4AddressToIntHTL(IPv4Address("192.168.255.255")));
+    }
+
+    @Test
+    public void testIntToInet4AddressHTL() {
+        assertEquals(IPv4Address("0.0.0.0"), intToInet4AddressHTL(0));
+        assertEquals(IPv4Address("255.128.0.0"), intToInet4AddressHTL(0x000080ff));
+        assertEquals(IPv4Address("10.255.128.0"), intToInet4AddressHTL(0x0080ff0a));
+        assertEquals(IPv4Address("10.255.254.0"), intToInet4AddressHTL(0x00feff0a));
+        assertEquals(IPv4Address("192.168.255.254"), intToInet4AddressHTL(0xfeffa8c0));
+        assertEquals(IPv4Address("192.168.255.255"), intToInet4AddressHTL(0xffffa8c0));
+    }
+
+    @Test
+    public void testInet4AddressToIntHTH() {
+        assertEquals(0, inet4AddressToIntHTH(IPv4Address("0.0.0.0")));
+        assertEquals(0xff800000, inet4AddressToIntHTH(IPv4Address("255.128.0.0")));
+        assertEquals(0x0aff8000, inet4AddressToIntHTH(IPv4Address("10.255.128.0")));
+        assertEquals(0x0afffe00, inet4AddressToIntHTH(IPv4Address("10.255.254.0")));
+        assertEquals(0xc0a8fffe, inet4AddressToIntHTH(IPv4Address("192.168.255.254")));
+        assertEquals(0xc0a8ffff, inet4AddressToIntHTH(IPv4Address("192.168.255.255")));
+    }
+
+    @Test
+    public void testIntToInet4AddressHTH() {
+        assertEquals(IPv4Address("0.0.0.0"), intToInet4AddressHTH(0));
+        assertEquals(IPv4Address("255.128.0.0"), intToInet4AddressHTH(0xff800000));
+        assertEquals(IPv4Address("10.255.128.0"), intToInet4AddressHTH(0x0aff8000));
+        assertEquals(IPv4Address("10.255.254.0"), intToInet4AddressHTH(0x0afffe00));
+        assertEquals(IPv4Address("192.168.255.254"), intToInet4AddressHTH(0xc0a8fffe));
+        assertEquals(IPv4Address("192.168.255.255"), intToInet4AddressHTH(0xc0a8ffff));
+    }
+
+    @Test
     public void testNetmaskToPrefixLength() {
-        assertEquals(0, NetworkUtils.netmaskToPrefixLength(IPv4Address("0.0.0.0")));
+        assertEquals(0, netmaskToPrefixLength(IPv4Address("0.0.0.0")));
-        assertEquals(9, NetworkUtils.netmaskToPrefixLength(IPv4Address("255.128.0.0")));
+        assertEquals(9, netmaskToPrefixLength(IPv4Address("255.128.0.0")));
-        assertEquals(17, NetworkUtils.netmaskToPrefixLength(IPv4Address("255.255.128.0")));
+        assertEquals(17, netmaskToPrefixLength(IPv4Address("255.255.128.0")));
-        assertEquals(23, NetworkUtils.netmaskToPrefixLength(IPv4Address("255.255.254.0")));
+        assertEquals(23, netmaskToPrefixLength(IPv4Address("255.255.254.0")));
-        assertEquals(31, NetworkUtils.netmaskToPrefixLength(IPv4Address("255.255.255.254")));
+        assertEquals(31, netmaskToPrefixLength(IPv4Address("255.255.255.254")));
-        assertEquals(32, NetworkUtils.netmaskToPrefixLength(IPv4Address("255.255.255.255")));
+        assertEquals(32, netmaskToPrefixLength(IPv4Address("255.255.255.255")));
 
         assertInvalidNetworkMask(IPv4Address("0.0.0.1"));
         assertInvalidNetworkMask(IPv4Address("255.255.255.253"));
         assertInvalidNetworkMask(IPv4Address("255.255.0.255"));
     }
 
-    @SmallTest
+
+    @Test
+    public void testPrefixLengthToV4NetmaskIntHTL() {
+        assertEquals(0, prefixLengthToV4NetmaskIntHTL(0));
+        assertEquals(0x000080ff /* 255.128.0.0 */, prefixLengthToV4NetmaskIntHTL(9));
+        assertEquals(0x0080ffff /* 255.255.128.0 */, prefixLengthToV4NetmaskIntHTL(17));
+        assertEquals(0x00feffff /* 255.255.254.0 */, prefixLengthToV4NetmaskIntHTL(23));
+        assertEquals(0xfeffffff /* 255.255.255.254 */, prefixLengthToV4NetmaskIntHTL(31));
+        assertEquals(0xffffffff /* 255.255.255.255 */, prefixLengthToV4NetmaskIntHTL(32));
+    }
+
+    @Test
+    public void testPrefixLengthToV4NetmaskIntHTH() {
+        assertEquals(0, prefixLengthToV4NetmaskIntHTH(0));
+        assertEquals(0xff800000 /* 255.128.0.0 */, prefixLengthToV4NetmaskIntHTH(9));
+        assertEquals(0xffff8000 /* 255.255.128.0 */, prefixLengthToV4NetmaskIntHTH(17));
+        assertEquals(0xfffffe00 /* 255.255.254.0 */, prefixLengthToV4NetmaskIntHTH(23));
+        assertEquals(0xfffffffe /* 255.255.255.254 */, prefixLengthToV4NetmaskIntHTH(31));
+        assertEquals(0xffffffff /* 255.255.255.255 */, prefixLengthToV4NetmaskIntHTH(32));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testPrefixLengthToV4NetmaskIntHTH_NegativeLength() {
+        prefixLengthToV4NetmaskIntHTH(-1);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testPrefixLengthToV4NetmaskIntHTH_LengthTooLarge() {
+        prefixLengthToV4NetmaskIntHTH(33);
+    }
+
+    private void checkAddressMasking(String expectedAddr, String addr, int prefixLength) {
+        final int prefix = prefixLengthToV4NetmaskIntHTH(prefixLength);
+        final int addrInt = inet4AddressToIntHTH(IPv4Address(addr));
+        assertEquals(IPv4Address(expectedAddr), intToInet4AddressHTH(prefix & addrInt));
+    }
+
+    @Test
+    public void testPrefixLengthToV4NetmaskIntHTH_MaskAddr() {
+        checkAddressMasking("192.168.0.0", "192.168.128.1", 16);
+        checkAddressMasking("255.240.0.0", "255.255.255.255", 12);
+        checkAddressMasking("255.255.255.255", "255.255.255.255", 32);
+        checkAddressMasking("0.0.0.0", "255.255.255.255", 0);
+    }
+
+    @Test
     public void testRoutedIPv4AddressCount() {
         final TreeSet<IpPrefix> set = new TreeSet<>(IpPrefix.lengthComparator());
         // No routes routes to no addresses.
@@ -118,7 +218,7 @@ public class NetworkUtilsTest extends TestCase {
         assertEquals(7l - 4 + 4 + 16 + 65536, NetworkUtils.routedIPv4AddressCount(set));
     }
 
-    @SmallTest
+    @Test
     public void testRoutedIPv6AddressCount() {
         final TreeSet<IpPrefix> set = new TreeSet<>(IpPrefix.lengthComparator());
         // No routes routes to no addresses.