/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 java.net;
import dalvik.system.BlockGuard;
import java.io.FileDescriptor;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamException;
import java.io.ObjectStreamField;
import java.io.Serializable;
import java.security.AccessController;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.List;
import org.apache.harmony.luni.platform.INetworkSystem;
import org.apache.harmony.luni.platform.Platform;
import org.apache.harmony.luni.util.PriviAction;
/**
* An Internet Protocol (IP) address. This can be either an IPv4 address or an IPv6 address, and
* in practice you'll have an instance of either {@code Inet4Address} or {@code Inet6Address} (this
* class cannot be instantiated directly). Most code does not need to distinguish between the two
* families, and should use {@code InetAddress}.
*
* <p>An {@code InetAddress} may have a hostname (accessible via {@code getHostName}), but may not,
* depending on how the {@code InetAddress} was created.
*
* <h4>IPv4 numeric address formats</h4>
* <p>The {@code getAllByName} method accepts IPv4 addresses in the following forms:
* <ul>
* <li>{@code "1.2.3.4"} - 1.2.3.4
* <li>{@code "1.2.3"} - 1.2.0.3
* <li>{@code "1.2"} - 1.0.0.2
* <li>{@code "16909060"} - 1.2.3.4
* </ul>
* <p>In the first three cases, each number is treated as an 8-bit value between 0 and 255.
* In the fourth case, the single number is treated as a 32-bit value representing the entire
* address.
* <p>Note that each numeric part can be expressed in decimal (as above) or hex. For example,
* {@code "0x01020304"} is equivalent to 1.2.3.4 and {@code "0xa.0xb.0xc.0xd"} is equivalent
* to 10.11.12.13.
*
* <p>Typically, only the four-dot decimal form ({@code "1.2.3.4"}) is ever used. Any method that
* <i>returns</i> a textual numeric address will use four-dot decimal form.
*
* <h4>IPv6 numeric address formats</h4>
* <p>The {@code getAllByName} method accepts IPv6 addresses in the following forms (this text
* comes from <a href="http://www.ietf.org/rfc/rfc2373.txt">RFC 2373</a>, which you should consult
* for full details of IPv6 addressing):
* <ul>
* <li><p>The preferred form is {@code x:x:x:x:x:x:x:x}, where the 'x's are the
* hexadecimal values of the eight 16-bit pieces of the address.
* Note that it is not necessary to write the leading zeros in an
* individual field, but there must be at least one numeral in every
* field (except for the case described in the next bullet).
* Examples:
* <pre>
* FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
* 1080:0:0:0:8:800:200C:417A</pre>
* </li>
* <li>Due to some methods of allocating certain styles of IPv6
* addresses, it will be common for addresses to contain long strings
* of zero bits. In order to make writing addresses containing zero
* bits easier a special syntax is available to compress the zeros.
* The use of "::" indicates multiple groups of 16-bits of zeros.
* The "::" can only appear once in an address. The "::" can also be
* used to compress the leading and/or trailing zeros in an address.
*
* For example the following addresses:
* <pre>
* 1080:0:0:0:8:800:200C:417A a unicast address
* FF01:0:0:0:0:0:0:101 a multicast address
* 0:0:0:0:0:0:0:1 the loopback address
* 0:0:0:0:0:0:0:0 the unspecified addresses</pre>
* may be represented as:
* <pre>
* 1080::8:800:200C:417A a unicast address
* FF01::101 a multicast address
* ::1 the loopback address
* :: the unspecified addresses</pre>
* </li>
* <li><p>An alternative form that is sometimes more convenient when dealing
* with a mixed environment of IPv4 and IPv6 nodes is
* {@code x:x:x:x:x:x:d.d.d.d}, where the 'x's are the hexadecimal values of
* the six high-order 16-bit pieces of the address, and the 'd's are
* the decimal values of the four low-order 8-bit pieces of the
* address (standard IPv4 representation). Examples:
* <pre>
* 0:0:0:0:0:0:13.1.68.3
* 0:0:0:0:0:FFFF:129.144.52.38</pre>
* or in compressed form:
* <pre>
* ::13.1.68.3
* ::FFFF:129.144.52.38</pre>
* </li>
* </ul>
* <p>Scopes are given using a trailing {@code %} followed by the scope id, as in
* {@code 1080::8:800:200C:417A%2} or {@code 1080::8:800:200C:417A%en0}.
* See <a href="https://www.ietf.org/rfc/rfc4007.txt">RFC 4007</a> for more on IPv6's scoped
* address architecture.
*
* <h4>DNS caching</h4>
* <p>On Android, addresses are cached for 600 seconds (10 minutes) by default. Failed lookups are
* cached for 10 seconds. The underlying C library or OS may cache for longer, but you can control
* the Java-level caching with the usual {@code "networkaddress.cache.ttl"} and
* {@code "networkaddress.cache.negative.ttl"} system properties. These are parsed as integer
* numbers of seconds, where the special value 0 means "don't cache" and -1 means "cache forever".
*
* <p>Note also that on Android – unlike the RI – the cache is not unbounded. The
* current implementation caches around 512 entries, removed on a least-recently-used basis.
* (Obviously, you should not rely on these details.)
*
* @see Inet4Address
* @see Inet6Address
*/
public class InetAddress implements Serializable {
/** Our Java-side DNS cache. */
private static final AddressCache addressCache = new AddressCache();
private final static INetworkSystem NETIMPL = Platform.getNetworkSystem();
private static final String ERRMSG_CONNECTION_REFUSED = "Connection refused";
private static final long serialVersionUID = 3286316764910316507L;
String hostName;
private static class WaitReachable {
}
private transient Object waitReachable = new WaitReachable();
private boolean reached;
private int addrCount;
int family = 0;
byte[] ipaddress;
/**
* Constructs an {@code InetAddress}.
*
* Note: this constructor should not be used. Creating an InetAddress
* without specifying whether it's an IPv4 or IPv6 address does not make
* sense, because subsequent code cannot know which of of the subclasses'
* methods need to be called to implement a given InetAddress method. The
* proper way to create an InetAddress is to call new Inet4Address or
* Inet6Address or to use one of the static methods that return
* InetAddresses (e.g., getByAddress). That is why the API does not have
* public constructors for any of these classes.
*/
InetAddress() {}
/**
* Compares this {@code InetAddress} instance against the specified address
* in {@code obj}. Two addresses are equal if their address byte arrays have
* the same length and if the bytes in the arrays are equal.
*
* @param obj
* the object to be tested for equality.
* @return {@code true} if both objects are equal, {@code false} otherwise.
*/
@Override
public boolean equals(Object obj) {
if (!(obj instanceof InetAddress)) {
return false;
}
return Arrays.equals(this.ipaddress, ((InetAddress) obj).ipaddress);
}
/**
* Returns the IP address represented by this {@code InetAddress} instance
* as a byte array. The elements are in network order (the highest order
* address byte is in the zeroth element).
*
* @return the address in form of a byte array.
*/
public byte[] getAddress() {
return ipaddress.clone();
}
static final Comparator<byte[]> SHORTEST_FIRST = new Comparator<byte[]>() {
public int compare(byte[] a1, byte[] a2) {
return a1.length - a2.length;
}
};
/**
* Converts an array of byte arrays representing raw IP addresses of a host
* to an array of InetAddress objects, sorting to respect the value of the
* system property {@code "java.net.preferIPv6Addresses"}.
*
* @param rawAddresses the raw addresses to convert.
* @param hostName the hostname corresponding to the IP address.
* @return the corresponding InetAddresses, appropriately sorted.
*/
static InetAddress[] bytesToInetAddresses(byte[][] rawAddresses, String hostName) {
// If we prefer IPv4, ignore the RFC3484 ordering we get from getaddrinfo
// and always put IPv4 addresses first. Arrays.sort() is stable, so the
// internal ordering will not be changed.
if (!preferIPv6Addresses()) {
Arrays.sort(rawAddresses, SHORTEST_FIRST);
}
// Convert the byte arrays to InetAddresses.
InetAddress[] returnedAddresses = new InetAddress[rawAddresses.length];
for (int i = 0; i < rawAddresses.length; i++) {
byte[] rawAddress = rawAddresses[i];
if (rawAddress.length == 16) {
returnedAddresses[i] = new Inet6Address(rawAddress, hostName);
} else if (rawAddress.length == 4) {
returnedAddresses[i] = new Inet4Address(rawAddress, hostName);
} else {
// Cannot happen, because the underlying code only returns
// addresses that are 4 or 16 bytes long.
throw new AssertionError("Impossible address length " +
rawAddress.length);
}
}
return returnedAddresses;
}
/**
* Gets all IP addresses associated with the given {@code host} identified
* by name or literal IP address. The IP address is resolved by the
* configured name service. If the host name is empty or {@code null} an
* {@code UnknownHostException} is thrown. If the host name is a literal IP
* address string an array with the corresponding single {@code InetAddress}
* is returned.
*
* @param host the hostname or literal IP string to be resolved.
* @return the array of addresses associated with the specified host.
* @throws UnknownHostException if the address lookup fails.
*/
public static InetAddress[] getAllByName(String host) throws UnknownHostException {
return getAllByNameImpl(host).clone();
}
/**
* Returns the InetAddresses for {@code host}. The returned array is shared
* and must be cloned before it is returned to application code.
*/
static InetAddress[] getAllByNameImpl(String host) throws UnknownHostException {
if (host == null || host.isEmpty()) {
if (preferIPv6Addresses()) {
return new InetAddress[] { Inet6Address.LOOPBACK, Inet4Address.LOOPBACK };
} else {
return new InetAddress[] { Inet4Address.LOOPBACK, Inet6Address.LOOPBACK };
}
}
// Special-case "0" for legacy IPv4 applications.
if (host.equals("0")) {
return new InetAddress[] { Inet4Address.ANY };
}
try {
byte[] hBytes = ipStringToByteArray(host);
if (hBytes.length == 4) {
return (new InetAddress[] { new Inet4Address(hBytes) });
} else if (hBytes.length == 16) {
return (new InetAddress[] { new Inet6Address(hBytes) });
} else {
throw new UnknownHostException(wrongAddressLength());
}
} catch (UnknownHostException e) {
}
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkConnect(host, -1);
}
return lookupHostByName(host);
}
private static native String byteArrayToIpString(byte[] address);
static native byte[] ipStringToByteArray(String address) throws UnknownHostException;
private static String wrongAddressLength() {
return "Invalid IP Address is neither 4 or 16 bytes";
}
static boolean preferIPv6Addresses() {
String propertyName = "java.net.preferIPv6Addresses";
String propertyValue = AccessController.doPrivileged(new PriviAction<String>(propertyName));
return Boolean.parseBoolean(propertyValue);
}
/**
* Returns the address of a host according to the given host string name
* {@code host}. The host string may be either a machine name or a dotted
* string IP address. If the latter, the {@code hostName} field is
* determined upon demand. {@code host} can be {@code null} which means that
* an address of the loopback interface is returned.
*
* @param host
* the hostName to be resolved to an address or {@code null}.
* @return the {@code InetAddress} instance representing the host.
* @throws UnknownHostException
* if the address lookup fails.
*/
public static InetAddress getByName(String host) throws UnknownHostException {
return getAllByNameImpl(host)[0];
}
/**
* Gets the textual representation of this IP address.
*
* @return the textual representation of host's IP address.
*/
public String getHostAddress() {
return byteArrayToIpString(ipaddress);
}
/**
* Gets the host name of this IP address. If the IP address could not be
* resolved, the textual representation in a dotted-quad-notation is
* returned.
*
* @return the corresponding string name of this IP address.
*/
public String getHostName() {
try {
if (hostName == null) {
int address = 0;
if (ipaddress.length == 4) {
address = bytesToInt(ipaddress, 0);
if (address == 0) {
return hostName = byteArrayToIpString(ipaddress);
}
}
hostName = getHostByAddrImpl(ipaddress).hostName;
if (hostName.equals("localhost") && ipaddress.length == 4
&& address != 0x7f000001) {
return hostName = byteArrayToIpString(ipaddress);
}
}
} catch (UnknownHostException e) {
return hostName = byteArrayToIpString(ipaddress);
}
SecurityManager security = System.getSecurityManager();
try {
// Only check host names, not addresses
if (security != null && isHostName(hostName)) {
security.checkConnect(hostName, -1);
}
} catch (SecurityException e) {
return byteArrayToIpString(ipaddress);
}
return hostName;
}
/**
* Gets the fully qualified domain name for the host associated with this IP
* address. If a security manager is set, it is checked if the method caller
* is allowed to get the hostname. Otherwise, the textual representation in
* a dotted-quad-notation is returned.
*
* @return the fully qualified domain name of this IP address.
*/
public String getCanonicalHostName() {
String canonicalName;
try {
int address = 0;
if (ipaddress.length == 4) {
address = bytesToInt(ipaddress, 0);
if (address == 0) {
return byteArrayToIpString(ipaddress);
}
}
canonicalName = getHostByAddrImpl(ipaddress).hostName;
} catch (UnknownHostException e) {
return byteArrayToIpString(ipaddress);
}
SecurityManager security = System.getSecurityManager();
try {
// Only check host names, not addresses
if (security != null && isHostName(canonicalName)) {
security.checkConnect(canonicalName, -1);
}
} catch (SecurityException e) {
return byteArrayToIpString(ipaddress);
}
return canonicalName;
}
/**
* Returns an {@code InetAddress} for the local host if possible, or the
* loopback address otherwise. This method works by getting the hostname,
* performing a DNS lookup, and then taking the first returned address.
* For devices with multiple network interfaces and/or multiple addresses
* per interface, this does not necessarily return the {@code InetAddress}
* you want.
*
* <p>Multiple interface/address configurations were relatively rare
* when this API was designed, but multiple interfaces are the default for
* modern mobile devices (with separate wifi and radio interfaces), and
* the need to support both IPv4 and IPv6 has made multiple addresses
* commonplace. New code should thus avoid this method except where it's
* basically being used to get a loopback address or equivalent.
*
* <p>There are two main ways to get a more specific answer:
* <ul>
* <li>If you have a connected socket, you should probably use
* {@link Socket#getLocalAddress} instead: that will give you the address
* that's actually in use for that connection. (It's not possible to ask
* the question "what local address would a connection to a given remote
* address use?"; you have to actually make the connection and see.)</li>
* <li>For other use cases, see {@link NetworkInterface}, which lets you
* enumerate all available network interfaces and their addresses.</li>
* </ul>
*
* <p>Note that if the host doesn't have a hostname set – as
* Android devices typically don't – this method will
* effectively return the loopback address, albeit by getting the name
* {@code localhost} and then doing a lookup to translate that to
* {@code 127.0.0.1}.
*
* @return an {@code InetAddress} representing the local host, or the
* loopback address.
* @throws UnknownHostException
* if the address lookup fails.
*/
public static InetAddress getLocalHost() throws UnknownHostException {
String host = gethostname();
SecurityManager security = System.getSecurityManager();
try {
if (security != null) {
security.checkConnect(host, -1);
}
} catch (SecurityException e) {
return Inet4Address.LOOPBACK;
}
return lookupHostByName(host)[0];
}
private static native String gethostname();
/**
* Gets the hashcode of the represented IP address.
*
* @return the appropriate hashcode value.
*/
@Override
public int hashCode() {
return Arrays.hashCode(ipaddress);
}
/*
* Returns whether this address is an IP multicast address or not. This
* implementation returns always {@code false}.
*
* @return {@code true} if this address is in the multicast group, {@code
* false} otherwise.
*/
public boolean isMulticastAddress() {
return false;
}
/**
* Resolves a hostname to its IP addresses using a cache.
*
* @param host the hostname to resolve.
* @return the IP addresses of the host.
*/
private static InetAddress[] lookupHostByName(String host) throws UnknownHostException {
BlockGuard.getThreadPolicy().onNetwork();
// Do we have a result cached?
InetAddress[] cachedResult = addressCache.get(host);
if (cachedResult != null) {
if (cachedResult.length > 0) {
// A cached positive result.
return cachedResult;
} else {
// A cached negative result.
throw new UnknownHostException(host);
}
}
try {
InetAddress[] addresses = bytesToInetAddresses(getaddrinfo(host), host);
addressCache.put(host, addresses);
return addresses;
} catch (UnknownHostException e) {
addressCache.putUnknownHost(host);
throw new UnknownHostException(host);
}
}
private static native byte[][] getaddrinfo(String name) throws UnknownHostException;
/**
* Query the IP stack for the host address. The host is in address form.
*
* @param addr
* the host address to lookup.
* @throws UnknownHostException
* if an error occurs during lookup.
*/
static InetAddress getHostByAddrImpl(byte[] addr)
throws UnknownHostException {
BlockGuard.getThreadPolicy().onNetwork();
if (addr.length == 4) {
return new Inet4Address(addr, getnameinfo(addr));
} else if (addr.length == 16) {
return new Inet6Address(addr, getnameinfo(addr));
} else {
throw new UnknownHostException(wrongAddressLength());
}
}
/**
* Resolves an IP address to a hostname. Thread safe.
*/
private static native String getnameinfo(byte[] addr);
static String getHostNameInternal(String host, boolean isCheck) throws UnknownHostException {
if (host == null || 0 == host.length()) {
return Inet4Address.LOOPBACK.getHostAddress();
}
if (isHostName(host)) {
if (isCheck) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
sm.checkConnect(host, -1);
}
}
return lookupHostByName(host)[0].getHostAddress();
}
return host;
}
/**
* Returns a string containing a concise, human-readable description of this
* IP address.
*
* @return the description, as host/address.
*/
@Override
public String toString() {
return (hostName == null ? "" : hostName) + "/" + getHostAddress();
}
/**
* Returns true if the string is a host name, false if it is an IP Address.
*/
static boolean isHostName(String value) {
try {
ipStringToByteArray(value);
return false;
} catch (UnknownHostException e) {
return true;
}
}
/**
* Returns whether this address is a loopback address or not. This
* implementation returns always {@code false}. Valid IPv4 loopback
* addresses are 127.d.d.d The only valid IPv6 loopback address is ::1.
*
* @return {@code true} if this instance represents a loopback address,
* {@code false} otherwise.
*/
public boolean isLoopbackAddress() {
return false;
}
/**
* Returns whether this address is a link-local address or not. This
* implementation returns always {@code false}.
* <p>
* Valid IPv6 link-local addresses are FE80::0 through to
* FEBF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.
* <p>
* There are no valid IPv4 link-local addresses.
*
* @return {@code true} if this instance represents a link-local address,
* {@code false} otherwise.
*/
public boolean isLinkLocalAddress() {
return false;
}
/**
* Returns whether this address is a site-local address or not. This
* implementation returns always {@code false}.
* <p>
* Valid IPv6 site-local addresses are FEC0::0 through to
* FEFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.
* <p>
* There are no valid IPv4 site-local addresses.
*
* @return {@code true} if this instance represents a site-local address,
* {@code false} otherwise.
*/
public boolean isSiteLocalAddress() {
return false;
}
/**
* Returns whether this address is a global multicast address or not. This
* implementation returns always {@code false}.
* <p>
* Valid IPv6 link-global multicast addresses are FFxE:/112 where x is a set
* of flags, and the additional 112 bits make up the global multicast
* address space.
* <p>
* Valid IPv4 global multicast addresses are between: 224.0.1.0 to
* 238.255.255.255.
*
* @return {@code true} if this instance represents a global multicast
* address, {@code false} otherwise.
*/
public boolean isMCGlobal() {
return false;
}
/**
* Returns whether this address is a node-local multicast address or not.
* This implementation returns always {@code false}.
* <p>
* Valid IPv6 node-local multicast addresses are FFx1:/112 where x is a set
* of flags, and the additional 112 bits make up the node-local multicast
* address space.
* <p>
* There are no valid IPv4 node-local multicast addresses.
*
* @return {@code true} if this instance represents a node-local multicast
* address, {@code false} otherwise.
*/
public boolean isMCNodeLocal() {
return false;
}
/**
* Returns whether this address is a link-local multicast address or not.
* This implementation returns always {@code false}.
* <p>
* Valid IPv6 link-local multicast addresses are FFx2:/112 where x is a set
* of flags, and the additional 112 bits make up the link-local multicast
* address space.
* <p>
* Valid IPv4 link-local addresses are between: 224.0.0.0 to 224.0.0.255
*
* @return {@code true} if this instance represents a link-local multicast
* address, {@code false} otherwise.
*/
public boolean isMCLinkLocal() {
return false;
}
/**
* Returns whether this address is a site-local multicast address or not.
* This implementation returns always {@code false}.
* <p>
* Valid IPv6 site-local multicast addresses are FFx5:/112 where x is a set
* of flags, and the additional 112 bits make up the site-local multicast
* address space.
* <p>
* Valid IPv4 site-local addresses are between: 239.252.0.0 to
* 239.255.255.255
*
* @return {@code true} if this instance represents a site-local multicast
* address, {@code false} otherwise.
*/
public boolean isMCSiteLocal() {
return false;
}
/**
* Returns whether this address is a organization-local multicast address or
* not. This implementation returns always {@code false}.
* <p>
* Valid IPv6 organization-local multicast addresses are FFx8:/112 where x
* is a set of flags, and the additional 112 bits make up the
* organization-local multicast address space.
* <p>
* Valid IPv4 organization-local addresses are between: 239.192.0.0 to
* 239.251.255.255
*
* @return {@code true} if this instance represents a organization-local
* multicast address, {@code false} otherwise.
*/
public boolean isMCOrgLocal() {
return false;
}
/**
* Returns whether this is a wildcard address or not. This implementation
* returns always {@code false}.
*
* @return {@code true} if this instance represents a wildcard address,
* {@code false} otherwise.
*/
public boolean isAnyLocalAddress() {
return false;
}
/**
* Tries to reach this {@code InetAddress}. This method first tries to use
* ICMP <i>(ICMP ECHO REQUEST)</i>. When first step fails, a TCP connection
* on port 7 (Echo) of the remote host is established.
*
* @param timeout
* timeout in milliseconds before the test fails if no connection
* could be established.
* @return {@code true} if this address is reachable, {@code false}
* otherwise.
* @throws IOException
* if an error occurs during an I/O operation.
* @throws IllegalArgumentException
* if timeout is less than zero.
*/
public boolean isReachable(int timeout) throws IOException {
return isReachable(null, 0, timeout);
}
/**
* Tries to reach this {@code InetAddress}. This method first tries to use
* ICMP <i>(ICMP ECHO REQUEST)</i>. When first step fails, a TCP connection
* on port 7 (Echo) of the remote host is established.
*
* @param networkInterface
* the network interface on which to connection should be
* established.
* @param ttl
* the maximum count of hops (time-to-live).
* @param timeout
* timeout in milliseconds before the test fails if no connection
* could be established.
* @return {@code true} if this address is reachable, {@code false}
* otherwise.
* @throws IOException
* if an error occurs during an I/O operation.
* @throws IllegalArgumentException
* if ttl or timeout is less than zero.
*/
public boolean isReachable(NetworkInterface networkInterface, final int ttl,
final int timeout) throws IOException {
if (ttl < 0 || timeout < 0) {
throw new IllegalArgumentException("ttl < 0 || timeout < 0");
}
if (networkInterface == null) {
return isReachableByTCP(this, null, timeout);
} else {
return isReachableByMultiThread(networkInterface, ttl, timeout);
}
}
/*
* Uses multi-Thread to try if isReachable, returns true if any of threads
* returns in time
*/
private boolean isReachableByMultiThread(NetworkInterface netif,
final int ttl, final int timeout)
throws IOException {
List<InetAddress> addresses = Collections.list(netif.getInetAddresses());
if (addresses.isEmpty()) {
return false;
}
reached = false;
addrCount = addresses.size();
boolean needWait = false;
for (final InetAddress addr : addresses) {
// loopback interface can only reach to local addresses
if (addr.isLoopbackAddress()) {
Enumeration<NetworkInterface> NetworkInterfaces = NetworkInterface
.getNetworkInterfaces();
while (NetworkInterfaces.hasMoreElements()) {
NetworkInterface networkInterface = NetworkInterfaces
.nextElement();
Enumeration<InetAddress> localAddresses = networkInterface
.getInetAddresses();
while (localAddresses.hasMoreElements()) {
if (InetAddress.this.equals(localAddresses
.nextElement())) {
return true;
}
}
}
synchronized (waitReachable) {
addrCount--;
if (addrCount == 0) {
// if count equals zero, all thread
// expired,notifies main thread
waitReachable.notifyAll();
}
}
continue;
}
needWait = true;
new Thread() {
@Override public void run() {
/*
* Spec violation! This implementation doesn't attempt an
* ICMP; it skips right to TCP echo.
*/
boolean threadReached = false;
try {
threadReached = isReachableByTCP(addr, InetAddress.this, timeout);
} catch (IOException e) {
}
synchronized (waitReachable) {
if (threadReached) {
// if thread reached this address, sets reached to
// true and notifies main thread
reached = true;
waitReachable.notifyAll();
} else {
addrCount--;
if (0 == addrCount) {
// if count equals zero, all thread
// expired,notifies main thread
waitReachable.notifyAll();
}
}
}
}
}.start();
}
if (needWait) {
synchronized (waitReachable) {
try {
while (!reached && (addrCount != 0)) {
// wait for notification
waitReachable.wait(1000);
}
} catch (InterruptedException e) {
// do nothing
}
return reached;
}
}
return false;
}
private boolean isReachableByTCP(InetAddress destination, InetAddress source, int timeout)
throws IOException {
FileDescriptor fd = new FileDescriptor();
boolean reached = false;
NETIMPL.socket(fd, true);
try {
if (null != source) {
NETIMPL.bind(fd, source, 0);
}
NETIMPL.connect(fd, destination, 7, timeout);
reached = true;
} catch (IOException e) {
if (ERRMSG_CONNECTION_REFUSED.equals(e.getMessage())) {
// Connection refused means the IP is reachable
reached = true;
}
}
NETIMPL.close(fd);
return reached;
}
/**
* Returns the {@code InetAddress} corresponding to the array of bytes. In
* the case of an IPv4 address there must be exactly 4 bytes and for IPv6
* exactly 16 bytes. If not, an {@code UnknownHostException} is thrown.
* <p>
* The IP address is not validated by a name service.
* <p>
* The high order byte is {@code ipAddress[0]}.
*
* @param ipAddress
* is either a 4 (IPv4) or 16 (IPv6) byte long array.
* @return an {@code InetAddress} instance representing the given IP address
* {@code ipAddress}.
* @throws UnknownHostException
* if the given byte array has no valid length.
*/
public static InetAddress getByAddress(byte[] ipAddress)
throws UnknownHostException {
// simply call the method by the same name specifying the default scope
// id of 0
return getByAddressInternal(null, ipAddress, 0);
}
/**
* Returns the {@code InetAddress} corresponding to the array of bytes. In
* the case of an IPv4 address there must be exactly 4 bytes and for IPv6
* exactly 16 bytes. If not, an {@code UnknownHostException} is thrown. The
* IP address is not validated by a name service. The high order byte is
* {@code ipAddress[0]}.
*
* @param ipAddress
* either a 4 (IPv4) or 16 (IPv6) byte array.
* @param scope_id
* the scope id for an IPV6 scoped address. If not a scoped
* address just pass in 0.
* @return the InetAddress
* @throws UnknownHostException
*/
static InetAddress getByAddress(byte[] ipAddress, int scope_id)
throws UnknownHostException {
return getByAddressInternal(null, ipAddress, scope_id);
}
private static boolean isIPv4MappedAddress(byte[] ipAddress) {
// Check if the address matches ::FFFF:d.d.d.d
// The first 10 bytes are 0. The next to are -1 (FF).
// The last 4 bytes are varied.
if (ipAddress == null || ipAddress.length != 16) {
return false;
}
for (int i = 0; i < 10; i++) {
if (ipAddress[i] != 0) {
return false;
}
}
if (ipAddress[10] != -1 || ipAddress[11] != -1) {
return false;
}
return true;
}
private static byte[] ipv4MappedToIPv4(byte[] mappedAddress) {
byte[] ipv4Address = new byte[4];
for(int i = 0; i < 4; i++) {
ipv4Address[i] = mappedAddress[12 + i];
}
return ipv4Address;
}
/**
* Returns the {@code InetAddress} corresponding to the array of bytes, and
* the given hostname. In the case of an IPv4 address there must be exactly
* 4 bytes and for IPv6 exactly 16 bytes. If not, an {@code
* UnknownHostException} will be thrown.
* <p>
* The host name and IP address are not validated.
* <p>
* The hostname either be a machine alias or a valid IPv6 or IPv4 address
* format.
* <p>
* The high order byte is {@code ipAddress[0]}.
*
* @param hostName
* the string representation of hostname or IP address.
* @param ipAddress
* either a 4 (IPv4) or 16 (IPv6) byte long array.
* @return an {@code InetAddress} instance representing the given IP address
* and hostname.
* @throws UnknownHostException
* if the given byte array has no valid length.
*/
public static InetAddress getByAddress(String hostName, byte[] ipAddress)
throws UnknownHostException {
// just call the method by the same name passing in a default scope id
// of 0
return getByAddressInternal(hostName, ipAddress, 0);
}
/**
* Returns the {@code InetAddress} corresponding to the array of bytes, and
* the given hostname. In the case of an IPv4 address there must be exactly
* 4 bytes and for IPv6 exactly 16 bytes. If not, an {@code
* UnknownHostException} is thrown. The host name and IP address are not
* validated. The hostname either be a machine alias or a valid IPv6 or IPv4
* address format. The high order byte is {@code ipAddress[0]}.
*
* @param hostName
* string representation of hostname or IP address.
* @param ipAddress
* either a 4 (IPv4) or 16 (IPv6) byte array.
* @param scope_id
* the scope id for a scoped address. If not a scoped address
* just pass in 0.
* @return the InetAddress
* @throws UnknownHostException
*/
static InetAddress getByAddressInternal(String hostName, byte[] ipAddress,
int scope_id) throws UnknownHostException {
if (ipAddress == null) {
throw new UnknownHostException("ipAddress == null");
}
switch (ipAddress.length) {
case 4:
return new Inet4Address(ipAddress.clone());
case 16:
// First check to see if the address is an IPv6-mapped
// IPv4 address. If it is, then we can make it a IPv4
// address, otherwise, we'll create an IPv6 address.
if (isIPv4MappedAddress(ipAddress)) {
return new Inet4Address(ipv4MappedToIPv4(ipAddress));
} else {
return new Inet6Address(ipAddress.clone(), scope_id);
}
default:
throw new UnknownHostException(
"Invalid IP Address is neither 4 or 16 bytes: " + hostName);
}
}
/**
* Takes the integer and chops it into 4 bytes, putting it into the byte
* array starting with the high order byte at the index start. This method
* makes no checks on the validity of the parameters.
*/
static void intToBytes(int value, byte[] bytes, int start) {
// Shift the int so the current byte is right-most
// Use a byte mask of 255 to single out the last byte.
bytes[start] = (byte) ((value >> 24) & 255);
bytes[start + 1] = (byte) ((value >> 16) & 255);
bytes[start + 2] = (byte) ((value >> 8) & 255);
bytes[start + 3] = (byte) (value & 255);
}
/**
* Takes the byte array and creates an integer out of four bytes starting at
* start as the high-order byte. This method makes no checks on the validity
* of the parameters.
*/
static int bytesToInt(byte[] bytes, int start) {
// First mask the byte with 255, as when a negative
// signed byte converts to an integer, it has bits
// on in the first 3 bytes, we are only concerned
// about the right-most 8 bits.
// Then shift the rightmost byte to align with its
// position in the integer.
int value = ((bytes[start + 3] & 255))
| ((bytes[start + 2] & 255) << 8)
| ((bytes[start + 1] & 255) << 16)
| ((bytes[start] & 255) << 24);
return value;
}
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("address", Integer.TYPE),
new ObjectStreamField("family", Integer.TYPE),
new ObjectStreamField("hostName", String.class) };
private void writeObject(ObjectOutputStream stream) throws IOException {
ObjectOutputStream.PutField fields = stream.putFields();
if (ipaddress == null) {
fields.put("address", 0);
} else {
fields.put("address", bytesToInt(ipaddress, 0));
}
fields.put("family", family);
fields.put("hostName", hostName);
stream.writeFields();
}
private void readObject(ObjectInputStream stream) throws IOException,
ClassNotFoundException {
ObjectInputStream.GetField fields = stream.readFields();
int addr = fields.get("address", 0);
ipaddress = new byte[4];
intToBytes(addr, ipaddress, 0);
hostName = (String) fields.get("hostName", null);
family = fields.get("family", 2);
}
/*
* The spec requires that if we encounter a generic InetAddress in
* serialized form then we should interpret it as an Inet4 address.
*/
private Object readResolve() throws ObjectStreamException {
return new Inet4Address(ipaddress, hostName);
}
}
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