/* * 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 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.util.Arrays; import java.util.Collections; import java.util.Comparator; import java.util.Enumeration; import java.util.List; import org.apache.harmony.luni.net.NetUtil; import org.apache.harmony.luni.platform.INetworkSystem; import org.apache.harmony.luni.platform.Platform; /** * 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}. *
* An {@code InetAddress} may have a hostname (accessible via {@code getHostName}), but may not, * depending on how the {@code InetAddress} was created. *
* 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". *
* 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;
static final int AF_INET = 2;
static final int AF_INET6 = 10;
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 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.
*
* There are two main ways to get a more specific answer:
* 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 {
// 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 {
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 {
NETIMPL.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}.
*
* Valid IPv6 link-local addresses are FE80::0 through to
* FEBF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.
*
* 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}.
*
* Valid IPv6 site-local addresses are FEC0::0 through to
* FEFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.
*
* 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}.
*
* 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.
*
* 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}.
*
* 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.
*
* 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}.
*
* 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.
*
* 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}.
*
* 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.
*
* 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}.
*
* 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.
*
* 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 (ICMP ECHO REQUEST). 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 (ICMP ECHO REQUEST). 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
* The IP address is not validated by a name service.
*
* 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.
*
* 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
* 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);
}
}
*
*
*