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Merge "MacAddress follow-up: define the core of the class"

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This commit is contained in:
Hugo Benichi
2017-11-09 12:22:17 +00:00
committed by Gerrit Code Review
parent fcbbf2b939 d380d14c4d
commit 005a90b337
2 changed files with 358 additions and 15 deletions
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240
core/java/android/net/MacAddress.java
View File

@@ -16,29 +16,128 @@
package android.net;
import com.android.internal.annotations.VisibleForTesting;
import android.os.Parcel;
import android.os.Parcelable;
import com.android.internal.util.BitUtils;
import java.util.Arrays;
import java.util.Random;
import java.util.StringJoiner;
/**
* Represents a mac address.
*
* @hide
*/
public final class MacAddress {
// TODO: add isLocallyAssigned().
// TODO: add getRandomAddress() factory method.
public final class MacAddress implements Parcelable {
private static final int ETHER_ADDR_LEN = 6;
private static final byte FF = (byte) 0xff;
@VisibleForTesting
static final byte[] ETHER_ADDR_BROADCAST = { FF, FF, FF, FF, FF, FF };
private static final byte[] ETHER_ADDR_BROADCAST = addr(0xff, 0xff, 0xff, 0xff, 0xff, 0xff);
/** The broadcast mac address. */
public static final MacAddress BROADCAST_ADDRESS = new MacAddress(ETHER_ADDR_BROADCAST);
/** The zero mac address. */
public static final MacAddress ALL_ZEROS_ADDRESS = new MacAddress(0);
/** Represents categories of mac addresses. */
public enum MacAddressType {
UNICAST,
MULTICAST,
BROADCAST;
}
private static final long VALID_LONG_MASK = BROADCAST_ADDRESS.mAddr;
private static final long LOCALLY_ASSIGNED_MASK = new MacAddress("2:0:0:0:0:0").mAddr;
private static final long MULTICAST_MASK = new MacAddress("1:0:0:0:0:0").mAddr;
private static final long OUI_MASK = new MacAddress("ff:ff:ff:0:0:0").mAddr;
private static final long NIC_MASK = new MacAddress("0:0:0:ff:ff:ff").mAddr;
private static final MacAddress BASE_ANDROID_MAC = new MacAddress("da:a1:19:0:0:0");
// Internal representation of the mac address as a single 8 byte long.
// The encoding scheme sets the two most significant bytes to 0. The 6 bytes of the
// mac address are encoded in the 6 least significant bytes of the long, where the first
// byte of the array is mapped to the 3rd highest logical byte of the long, the second
// byte of the array is mapped to the 4th highest logical byte of the long, and so on.
private final long mAddr;
private MacAddress(long addr) {
mAddr = addr;
}
/** Creates a MacAddress for the given byte representation. */
public MacAddress(byte[] addr) {
this(longAddrFromByteAddr(addr));
}
/** Creates a MacAddress for the given string representation. */
public MacAddress(String addr) {
this(longAddrFromByteAddr(byteAddrFromStringAddr(addr)));
}
/** Returns the MacAddressType of this MacAddress. */
public MacAddressType addressType() {
if (equals(BROADCAST_ADDRESS)) {
return MacAddressType.BROADCAST;
}
if (isMulticastAddress()) {
return MacAddressType.MULTICAST;
}
return MacAddressType.UNICAST;
}
/** Returns true if this MacAddress corresponds to a multicast address. */
public boolean isMulticastAddress() {
return (mAddr & MULTICAST_MASK) != 0;
}
/** Returns true if this MacAddress corresponds to a locally assigned address. */
public boolean isLocallyAssigned() {
return (mAddr & LOCALLY_ASSIGNED_MASK) != 0;
}
/** Returns a byte array representation of this MacAddress. */
public byte[] toByteArray() {
return byteAddrFromLongAddr(mAddr);
}
@Override
public String toString() {
return stringAddrFromByteAddr(byteAddrFromLongAddr(mAddr));
}
@Override
public int hashCode() {
return (int) ((mAddr >> 32) ^ mAddr);
}
@Override
public boolean equals(Object o) {
return (o instanceof MacAddress) && ((MacAddress) o).mAddr == mAddr;
}
@Override
public void writeToParcel(Parcel out, int flags) {
out.writeLong(mAddr);
}
@Override
public int describeContents() {
return 0;
}
public static final Parcelable.Creator<MacAddress> CREATOR =
new Parcelable.Creator<MacAddress>() {
public MacAddress createFromParcel(Parcel in) {
return new MacAddress(in.readLong());
}
public MacAddress[] newArray(int size) {
return new MacAddress[size];
}
};
/** Return true if the given byte array is not null and has the length of a mac address. */
public static boolean isMacAddress(byte[] addr) {
return addr != null && addr.length == ETHER_ADDR_LEN;
@@ -46,17 +145,130 @@ public final class MacAddress {
/**
* Return the MacAddressType of the mac address represented by the given byte array,
* or null if the given byte array does not represent an mac address. */
* or null if the given byte array does not represent an mac address.
*/
public static MacAddressType macAddressType(byte[] addr) {
if (!isMacAddress(addr)) {
return null;
}
if (Arrays.equals(addr, ETHER_ADDR_BROADCAST)) {
return MacAddressType.BROADCAST;
return new MacAddress(addr).addressType();
}
/** DOCME */
public static byte[] byteAddrFromStringAddr(String addr) {
if (addr == null) {
throw new IllegalArgumentException("cannot convert the null String");
}
if ((addr[0] & 0x01) == 1) {
return MacAddressType.MULTICAST;
String[] parts = addr.split(":");
if (parts.length != ETHER_ADDR_LEN) {
throw new IllegalArgumentException(addr + " was not a valid MAC address");
}
return MacAddressType.UNICAST;
byte[] bytes = new byte[ETHER_ADDR_LEN];
for (int i = 0; i < ETHER_ADDR_LEN; i++) {
int x = Integer.valueOf(parts[i], 16);
if (x < 0 || 0xff < x) {
throw new IllegalArgumentException(addr + "was not a valid MAC address");
}
bytes[i] = (byte) x;
}
return bytes;
}
/** DOCME */
public static String stringAddrFromByteAddr(byte[] addr) {
if (!isMacAddress(addr)) {
return null;
}
StringJoiner j = new StringJoiner(":");
for (byte b : addr) {
j.add(Integer.toHexString(BitUtils.uint8(b)));
}
return j.toString();
}
/** @hide */
public static byte[] byteAddrFromLongAddr(long addr) {
byte[] bytes = new byte[ETHER_ADDR_LEN];
int index = ETHER_ADDR_LEN;
while (index-- > 0) {
bytes[index] = (byte) addr;
addr = addr >> 8;
}
return bytes;
}
/** @hide */
public static long longAddrFromByteAddr(byte[] addr) {
if (!isMacAddress(addr)) {
throw new IllegalArgumentException(
Arrays.toString(addr) + " was not a valid MAC address");
}
long longAddr = 0;
for (byte b : addr) {
longAddr = (longAddr << 8) + BitUtils.uint8(b);
}
return longAddr;
}
/** @hide */
public static long longAddrFromStringAddr(String addr) {
if (addr == null) {
throw new IllegalArgumentException("cannot convert the null String");
}
String[] parts = addr.split(":");
if (parts.length != ETHER_ADDR_LEN) {
throw new IllegalArgumentException(addr + " was not a valid MAC address");
}
long longAddr = 0;
int index = ETHER_ADDR_LEN;
while (index-- > 0) {
int x = Integer.valueOf(parts[index], 16);
if (x < 0 || 0xff < x) {
throw new IllegalArgumentException(addr + "was not a valid MAC address");
}
longAddr = x + (longAddr << 8);
}
return longAddr;
}
/** @hide */
public static String stringAddrFromLongAddr(long addr) {
addr = Long.reverseBytes(addr) >> 16;
StringJoiner j = new StringJoiner(":");
for (int i = 0; i < ETHER_ADDR_LEN; i++) {
j.add(Integer.toHexString((byte) addr));
addr = addr >> 8;
}
return j.toString();
}
/**
* Returns a randomely generated mac address with the Android OUI value "DA-A1-19".
* The locally assigned bit is always set to 1.
*/
public static MacAddress getRandomAddress() {
return getRandomAddress(BASE_ANDROID_MAC, new Random());
}
/**
* Returns a randomely generated mac address using the given Random object and the same
* OUI values as the given MacAddress. The locally assigned bit is always set to 1.
*/
public static MacAddress getRandomAddress(MacAddress base, Random r) {
long longAddr = (base.mAddr & OUI_MASK) | (NIC_MASK & r.nextLong()) | LOCALLY_ASSIGNED_MASK;
return new MacAddress(longAddr);
}
// Convenience function for working around the lack of byte literals.
private static byte[] addr(int... in) {
if (in.length != ETHER_ADDR_LEN) {
throw new IllegalArgumentException(Arrays.toString(in)
+ " was not an array with length equal to " + ETHER_ADDR_LEN);
}
byte[] out = new byte[ETHER_ADDR_LEN];
for (int i = 0; i < ETHER_ADDR_LEN; i++) {
out[i] = (byte) in[i];
}
return out;
}
}

133
tests/net/java/android/net/MacAddressTest.java
View File

@@ -19,12 +19,14 @@ package android.net;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.fail;
import android.net.MacAddress.MacAddressType;
import android.support.test.filters.SmallTest;
import android.support.test.runner.AndroidJUnit4;
import java.util.Arrays;
import java.util.Random;
import org.junit.Test;
import org.junit.runner.RunWith;
@@ -64,10 +66,139 @@ public class MacAddressTest {
String msg = String.format("expected type of %s to be %s, but got %s",
Arrays.toString(t.addr), t.expected, got);
assertEquals(msg, t.expected, got);
if (got != null) {
assertEquals(got, new MacAddress(t.addr).addressType());
}
}
}
static byte[] toByteArray(int[] in) {
@Test
public void testIsMulticastAddress() {
MacAddress[] multicastAddresses = {
MacAddress.BROADCAST_ADDRESS,
new MacAddress("07:00:d3:56:8a:c4"),
new MacAddress("33:33:aa:bb:cc:dd"),
};
MacAddress[] unicastAddresses = {
MacAddress.ALL_ZEROS_ADDRESS,
new MacAddress("00:01:44:55:66:77"),
new MacAddress("08:00:22:33:44:55"),
new MacAddress("06:00:00:00:00:00"),
};
for (MacAddress mac : multicastAddresses) {
String msg = mac.toString() + " expected to be a multicast address";
assertTrue(msg, mac.isMulticastAddress());
}
for (MacAddress mac : unicastAddresses) {
String msg = mac.toString() + " expected not to be a multicast address";
assertFalse(msg, mac.isMulticastAddress());
}
}
@Test
public void testIsLocallyAssignedAddress() {
MacAddress[] localAddresses = {
new MacAddress("06:00:00:00:00:00"),
new MacAddress("07:00:d3:56:8a:c4"),
new MacAddress("33:33:aa:bb:cc:dd"),
};
MacAddress[] universalAddresses = {
new MacAddress("00:01:44:55:66:77"),
new MacAddress("08:00:22:33:44:55"),
};
for (MacAddress mac : localAddresses) {
String msg = mac.toString() + " expected to be a locally assigned address";
assertTrue(msg, mac.isLocallyAssigned());
}
for (MacAddress mac : universalAddresses) {
String msg = mac.toString() + " expected not to be globally unique address";
assertFalse(msg, mac.isLocallyAssigned());
}
}
@Test
public void testMacAddressConversions() {
final int iterations = 10000;
for (int i = 0; i < iterations; i++) {
MacAddress mac = MacAddress.getRandomAddress();
String stringRepr = mac.toString();
byte[] bytesRepr = mac.toByteArray();
assertEquals(mac, new MacAddress(stringRepr));
assertEquals(mac, new MacAddress(bytesRepr));
}
}
@Test
public void testMacAddressRandomGeneration() {
final int iterations = 1000;
final String expectedAndroidOui = "da:a1:19";
for (int i = 0; i < iterations; i++) {
MacAddress mac = MacAddress.getRandomAddress();
String stringRepr = mac.toString();
assertTrue(stringRepr + " expected to be a locally assigned address",
mac.isLocallyAssigned());
assertTrue(stringRepr + " expected to begin with " + expectedAndroidOui,
stringRepr.startsWith(expectedAndroidOui));
}
final Random r = new Random();
final String anotherOui = "24:5f:78";
final String expectedLocalOui = "26:5f:78";
final MacAddress base = new MacAddress(anotherOui + ":0:0:0");
for (int i = 0; i < iterations; i++) {
MacAddress mac = MacAddress.getRandomAddress(base, r);
String stringRepr = mac.toString();
assertTrue(stringRepr + " expected to be a locally assigned address",
mac.isLocallyAssigned());
assertTrue(stringRepr + " expected to begin with " + expectedLocalOui,
stringRepr.startsWith(expectedLocalOui));
}
}
@Test
public void testConstructorInputValidation() {
String[] invalidStringAddresses = {
null,
"",
"abcd",
"1:2:3:4:5",
"1:2:3:4:5:6:7",
"10000:2:3:4:5:6",
};
for (String s : invalidStringAddresses) {
try {
MacAddress mac = new MacAddress(s);
fail("new MacAddress(" + s + ") should have failed, but returned " + mac);
} catch (IllegalArgumentException excepted) {
}
}
byte[][] invalidBytesAddresses = {
null,
{},
{1,2,3,4,5},
{1,2,3,4,5,6,7},
};
for (byte[] b : invalidBytesAddresses) {
try {
MacAddress mac = new MacAddress(b);
fail("new MacAddress(" + Arrays.toString(b)
+ ") should have failed, but returned " + mac);
} catch (IllegalArgumentException excepted) {
}
}
}
static byte[] toByteArray(int... in) {
byte[] out = new byte[in.length];
for (int i = 0; i < in.length; i++) {
out[i] = (byte) in[i];