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* Copyright (c) 1995, 2018, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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package java.net;
import java.util.
HashMap;
import java.util.
LinkedHashMap;
import java.util.
Random;
import java.util.
Iterator;
import java.util.
LinkedList;
import java.util.
List;
import java.util.
ArrayList;
import java.util.
ServiceLoader;
import java.security.
AccessController;
import java.io.
ObjectStreamException;
import java.io.
ObjectStreamField;
import java.io.
IOException;
import java.io.
InvalidObjectException;
import java.io.
ObjectInputStream;
import java.io.
ObjectInputStream.
GetField;
import java.io.
ObjectOutputStream;
import java.io.
ObjectOutputStream.
PutField;
import sun.security.action.*;
import sun.net.
InetAddressCachePolicy;
import sun.net.util.
IPAddressUtil;
import sun.net.spi.nameservice.*;
/**
* This class represents an Internet Protocol (IP) address.
*
* <p> An IP address is either a 32-bit or 128-bit unsigned number
* used by IP, a lower-level protocol on which protocols like UDP and
* TCP are built. The IP address architecture is defined by <a
* href="http://www.ietf.org/rfc/rfc790.txt"><i>RFC 790:
* Assigned Numbers</i></a>, <a
* href="http://www.ietf.org/rfc/rfc1918.txt"> <i>RFC 1918:
* Address Allocation for Private Internets</i></a>, <a
* href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC 2365:
* Administratively Scoped IP Multicast</i></a>, and <a
* href="http://www.ietf.org/rfc/rfc2373.txt"><i>RFC 2373: IP
* Version 6 Addressing Architecture</i></a>. An instance of an
* InetAddress consists of an IP address and possibly its
* corresponding host name (depending on whether it is constructed
* with a host name or whether it has already done reverse host name
* resolution).
*
* <h3> Address types </h3>
*
* <blockquote><table cellspacing=2 summary="Description of unicast and multicast address types">
* <tr><th valign=top><i>unicast</i></th>
* <td>An identifier for a single interface. A packet sent to
* a unicast address is delivered to the interface identified by
* that address.
*
* <p> The Unspecified Address -- Also called anylocal or wildcard
* address. It must never be assigned to any node. It indicates the
* absence of an address. One example of its use is as the target of
* bind, which allows a server to accept a client connection on any
* interface, in case the server host has multiple interfaces.
*
* <p> The <i>unspecified</i> address must not be used as
* the destination address of an IP packet.
*
* <p> The <i>Loopback</i> Addresses -- This is the address
* assigned to the loopback interface. Anything sent to this
* IP address loops around and becomes IP input on the local
* host. This address is often used when testing a
* client.</td></tr>
* <tr><th valign=top><i>multicast</i></th>
* <td>An identifier for a set of interfaces (typically belonging
* to different nodes). A packet sent to a multicast address is
* delivered to all interfaces identified by that address.</td></tr>
* </table></blockquote>
*
* <h4> IP address scope </h4>
*
* <p> <i>Link-local</i> addresses are designed to be used for addressing
* on a single link for purposes such as auto-address configuration,
* neighbor discovery, or when no routers are present.
*
* <p> <i>Site-local</i> addresses are designed to be used for addressing
* inside of a site without the need for a global prefix.
*
* <p> <i>Global</i> addresses are unique across the internet.
*
* <h4> Textual representation of IP addresses </h4>
*
* The textual representation of an IP address is address family specific.
*
* <p>
*
* For IPv4 address format, please refer to <A
* HREF="Inet4Address.html#format">Inet4Address#format</A>; For IPv6
* address format, please refer to <A
* HREF="Inet6Address.html#format">Inet6Address#format</A>.
*
* <P>There is a <a href="doc-files/net-properties.html#Ipv4IPv6">couple of
* System Properties</a> affecting how IPv4 and IPv6 addresses are used.</P>
*
* <h4> Host Name Resolution </h4>
*
* Host name-to-IP address <i>resolution</i> is accomplished through
* the use of a combination of local machine configuration information
* and network naming services such as the Domain Name System (DNS)
* and Network Information Service(NIS). The particular naming
* services(s) being used is by default the local machine configured
* one. For any host name, its corresponding IP address is returned.
*
* <p> <i>Reverse name resolution</i> means that for any IP address,
* the host associated with the IP address is returned.
*
* <p> The InetAddress class provides methods to resolve host names to
* their IP addresses and vice versa.
*
* <h4> InetAddress Caching </h4>
*
* The InetAddress class has a cache to store successful as well as
* unsuccessful host name resolutions.
*
* <p> By default, when a security manager is installed, in order to
* protect against DNS spoofing attacks,
* the result of positive host name resolutions are
* cached forever. When a security manager is not installed, the default
* behavior is to cache entries for a finite (implementation dependent)
* period of time. The result of unsuccessful host
* name resolution is cached for a very short period of time (10
* seconds) to improve performance.
*
* <p> If the default behavior is not desired, then a Java security property
* can be set to a different Time-to-live (TTL) value for positive
* caching. Likewise, a system admin can configure a different
* negative caching TTL value when needed.
*
* <p> Two Java security properties control the TTL values used for
* positive and negative host name resolution caching:
*
* <blockquote>
* <dl>
* <dt><b>networkaddress.cache.ttl</b></dt>
* <dd>Indicates the caching policy for successful name lookups from
* the name service. The value is specified as as integer to indicate
* the number of seconds to cache the successful lookup. The default
* setting is to cache for an implementation specific period of time.
* <p>
* A value of -1 indicates "cache forever".
* </dd>
* <dt><b>networkaddress.cache.negative.ttl</b> (default: 10)</dt>
* <dd>Indicates the caching policy for un-successful name lookups
* from the name service. The value is specified as as integer to
* indicate the number of seconds to cache the failure for
* un-successful lookups.
* <p>
* A value of 0 indicates "never cache".
* A value of -1 indicates "cache forever".
* </dd>
* </dl>
* </blockquote>
*
* @author Chris Warth
* @see java.net.InetAddress#getByAddress(byte[])
* @see java.net.InetAddress#getByAddress(java.lang.String, byte[])
* @see java.net.InetAddress#getAllByName(java.lang.String)
* @see java.net.InetAddress#getByName(java.lang.String)
* @see java.net.InetAddress#getLocalHost()
* @since JDK1.0
*/
public
class
InetAddress implements java.io.
Serializable {
/**
* Specify the address family: Internet Protocol, Version 4
* @since 1.4
*/
static final int
IPv4 = 1;
/**
* Specify the address family: Internet Protocol, Version 6
* @since 1.4
*/
static final int
IPv6 = 2;
/* Specify address family preference */
static transient boolean
preferIPv6Address = false;
static class
InetAddressHolder {
/**
* Reserve the original application specified hostname.
*
* The original hostname is useful for domain-based endpoint
* identification (see RFC 2818 and RFC 6125). If an address
* was created with a raw IP address, a reverse name lookup
* may introduce endpoint identification security issue via
* DNS forging.
*
* Oracle JSSE provider is using this original hostname, via
* sun.misc.JavaNetAccess, for SSL/TLS endpoint identification.
*
* Note: May define a new public method in the future if necessary.
*/
String originalHostName;
InetAddressHolder() {}
InetAddressHolder(
String hostName, int
address, int
family) {
this.
originalHostName =
hostName;
this.
hostName =
hostName;
this.
address =
address;
this.
family =
family;
}
void
init(
String hostName, int
family) {
this.
originalHostName =
hostName;
this.
hostName =
hostName;
if (
family != -1) {
this.
family =
family;
}
}
String hostName;
String getHostName() {
return
hostName;
}
String getOriginalHostName() {
return
originalHostName;
}
/**
* Holds a 32-bit IPv4 address.
*/
int
address;
int
getAddress() {
return
address;
}
/**
* Specifies the address family type, for instance, '1' for IPv4
* addresses, and '2' for IPv6 addresses.
*/
int
family;
int
getFamily() {
return
family;
}
}
/* Used to store the serializable fields of InetAddress */
final transient
InetAddressHolder holder;
InetAddressHolder holder() {
return
holder;
}
/* Used to store the name service provider */
private static
List<
NameService>
nameServices = null;
/* Used to store the best available hostname */
private transient
String canonicalHostName = null;
/** use serialVersionUID from JDK 1.0.2 for interoperability */
private static final long
serialVersionUID = 3286316764910316507L;
/*
* Load net library into runtime, and perform initializations.
*/
static {
preferIPv6Address = java.security.
AccessController.
doPrivileged(
new
GetBooleanAction("java.net.preferIPv6Addresses")).
booleanValue();
AccessController.
doPrivileged(
new java.security.
PrivilegedAction<
Void>() {
public
Void run() {
System.
loadLibrary("net");
return null;
}
});
init();
}
/**
* Constructor for the Socket.accept() method.
* This creates an empty InetAddress, which is filled in by
* the accept() method. This InetAddress, however, is not
* put in the address cache, since it is not created by name.
*/
InetAddress() {
holder = new
InetAddressHolder();
}
/**
* Replaces the de-serialized object with an Inet4Address object.
*
* @return the alternate object to the de-serialized object.
*
* @throws ObjectStreamException if a new object replacing this
* object could not be created
*/
private
Object readResolve() throws
ObjectStreamException {
// will replace the deserialized 'this' object
return new
Inet4Address(
holder().
getHostName(),
holder().
getAddress());
}
/**
* Utility routine to check if the InetAddress is an
* IP multicast address.
* @return a {@code boolean} indicating if the InetAddress is
* an IP multicast address
* @since JDK1.1
*/
public boolean
isMulticastAddress() {
return false;
}
/**
* Utility routine to check if the InetAddress in a wildcard address.
* @return a {@code boolean} indicating if the Inetaddress is
* a wildcard address.
* @since 1.4
*/
public boolean
isAnyLocalAddress() {
return false;
}
/**
* Utility routine to check if the InetAddress is a loopback address.
*
* @return a {@code boolean} indicating if the InetAddress is
* a loopback address; or false otherwise.
* @since 1.4
*/
public boolean
isLoopbackAddress() {
return false;
}
/**
* Utility routine to check if the InetAddress is an link local address.
*
* @return a {@code boolean} indicating if the InetAddress is
* a link local address; or false if address is not a link local unicast address.
* @since 1.4
*/
public boolean
isLinkLocalAddress() {
return false;
}
/**
* Utility routine to check if the InetAddress is a site local address.
*
* @return a {@code boolean} indicating if the InetAddress is
* a site local address; or false if address is not a site local unicast address.
* @since 1.4
*/
public boolean
isSiteLocalAddress() {
return false;
}
/**
* Utility routine to check if the multicast address has global scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of global scope, false if it is not
* of global scope or it is not a multicast address
* @since 1.4
*/
public boolean
isMCGlobal() {
return false;
}
/**
* Utility routine to check if the multicast address has node scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of node-local scope, false if it is not
* of node-local scope or it is not a multicast address
* @since 1.4
*/
public boolean
isMCNodeLocal() {
return false;
}
/**
* Utility routine to check if the multicast address has link scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of link-local scope, false if it is not
* of link-local scope or it is not a multicast address
* @since 1.4
*/
public boolean
isMCLinkLocal() {
return false;
}
/**
* Utility routine to check if the multicast address has site scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of site-local scope, false if it is not
* of site-local scope or it is not a multicast address
* @since 1.4
*/
public boolean
isMCSiteLocal() {
return false;
}
/**
* Utility routine to check if the multicast address has organization scope.
*
* @return a {@code boolean} indicating if the address has
* is a multicast address of organization-local scope,
* false if it is not of organization-local scope
* or it is not a multicast address
* @since 1.4
*/
public boolean
isMCOrgLocal() {
return false;
}
/**
* Test whether that address is reachable. Best effort is made by the
* implementation to try to reach the host, but firewalls and server
* configuration may block requests resulting in a unreachable status
* while some specific ports may be accessible.
* A typical implementation will use ICMP ECHO REQUESTs if the
* privilege can be obtained, otherwise it will try to establish
* a TCP connection on port 7 (Echo) of the destination host.
* <p>
* The timeout value, in milliseconds, indicates the maximum amount of time
* the try should take. If the operation times out before getting an
* answer, the host is deemed unreachable. A negative value will result
* in an IllegalArgumentException being thrown.
*
* @param timeout the time, in milliseconds, before the call aborts
* @return a {@code boolean} indicating if the address is reachable.
* @throws IOException if a network error occurs
* @throws IllegalArgumentException if {@code timeout} is negative.
* @since 1.5
*/
public boolean
isReachable(int
timeout) throws
IOException {
return
isReachable(null, 0 ,
timeout);
}
/**
* Test whether that address is reachable. Best effort is made by the
* implementation to try to reach the host, but firewalls and server
* configuration may block requests resulting in a unreachable status
* while some specific ports may be accessible.
* A typical implementation will use ICMP ECHO REQUESTs if the
* privilege can be obtained, otherwise it will try to establish
* a TCP connection on port 7 (Echo) of the destination host.
* <p>
* The {@code network interface} and {@code ttl} parameters
* let the caller specify which network interface the test will go through
* and the maximum number of hops the packets should go through.
* A negative value for the {@code ttl} will result in an
* IllegalArgumentException being thrown.
* <p>
* The timeout value, in milliseconds, indicates the maximum amount of time
* the try should take. If the operation times out before getting an
* answer, the host is deemed unreachable. A negative value will result
* in an IllegalArgumentException being thrown.
*
* @param netif the NetworkInterface through which the
* test will be done, or null for any interface
* @param ttl the maximum numbers of hops to try or 0 for the
* default
* @param timeout the time, in milliseconds, before the call aborts
* @throws IllegalArgumentException if either {@code timeout}
* or {@code ttl} are negative.
* @return a {@code boolean}indicating if the address is reachable.
* @throws IOException if a network error occurs
* @since 1.5
*/
public boolean
isReachable(
NetworkInterface netif, int
ttl,
int
timeout) throws
IOException {
if (
ttl < 0)
throw new
IllegalArgumentException("ttl can't be negative");
if (
timeout < 0)
throw new
IllegalArgumentException("timeout can't be negative");
return
impl.
isReachable(this,
timeout,
netif,
ttl);
}
/**
* Gets the host name for this IP address.
*
* <p>If this InetAddress was created with a host name,
* this host name will be remembered and returned;
* otherwise, a reverse name lookup will be performed
* and the result will be returned based on the system
* configured name lookup service. If a lookup of the name service
* is required, call
* {@link #getCanonicalHostName() getCanonicalHostName}.
*
* <p>If there is a security manager, its
* {@code checkConnect} method is first called
* with the hostname and {@code -1}
* as its arguments to see if the operation is allowed.
* If the operation is not allowed, it will return
* the textual representation of the IP address.
*
* @return the host name for this IP address, or if the operation
* is not allowed by the security check, the textual
* representation of the IP address.
*
* @see InetAddress#getCanonicalHostName
* @see SecurityManager#checkConnect
*/
public
String getHostName() {
return
getHostName(true);
}
/**
* Returns the hostname for this address.
* If the host is equal to null, then this address refers to any
* of the local machine's available network addresses.
* this is package private so SocketPermission can make calls into
* here without a security check.
*
* <p>If there is a security manager, this method first
* calls its {@code checkConnect} method
* with the hostname and {@code -1}
* as its arguments to see if the calling code is allowed to know
* the hostname for this IP address, i.e., to connect to the host.
* If the operation is not allowed, it will return
* the textual representation of the IP address.
*
* @return the host name for this IP address, or if the operation
* is not allowed by the security check, the textual
* representation of the IP address.
*
* @param check make security check if true
*
* @see SecurityManager#checkConnect
*/
String getHostName(boolean
check) {
if (
holder().
getHostName() == null) {
holder().
hostName =
InetAddress.
getHostFromNameService(this,
check);
}
return
holder().
getHostName();
}
/**
* Gets the fully qualified domain name for this IP address.
* Best effort method, meaning we may not be able to return
* the FQDN depending on the underlying system configuration.
*
* <p>If there is a security manager, this method first
* calls its {@code checkConnect} method
* with the hostname and {@code -1}
* as its arguments to see if the calling code is allowed to know
* the hostname for this IP address, i.e., to connect to the host.
* If the operation is not allowed, it will return
* the textual representation of the IP address.
*
* @return the fully qualified domain name for this IP address,
* or if the operation is not allowed by the security check,
* the textual representation of the IP address.
*
* @see SecurityManager#checkConnect
*
* @since 1.4
*/
public
String getCanonicalHostName() {
if (
canonicalHostName == null) {
canonicalHostName =
InetAddress.
getHostFromNameService(this, true);
}
return
canonicalHostName;
}
/**
* Returns the hostname for this address.
*
* <p>If there is a security manager, this method first
* calls its {@code checkConnect} method
* with the hostname and {@code -1}
* as its arguments to see if the calling code is allowed to know
* the hostname for this IP address, i.e., to connect to the host.
* If the operation is not allowed, it will return
* the textual representation of the IP address.
*
* @return the host name for this IP address, or if the operation
* is not allowed by the security check, the textual
* representation of the IP address.
*
* @param check make security check if true
*
* @see SecurityManager#checkConnect
*/
private static
String getHostFromNameService(
InetAddress addr, boolean
check) {
String host = null;
for (
NameService nameService :
nameServices) {
try {
// first lookup the hostname
host =
nameService.
getHostByAddr(
addr.
getAddress());
/* check to see if calling code is allowed to know
* the hostname for this IP address, ie, connect to the host
*/
if (
check) {
SecurityManager sec =
System.
getSecurityManager();
if (
sec != null) {
sec.
checkConnect(
host, -1);
}
}
/* now get all the IP addresses for this hostname,
* and make sure one of them matches the original IP
* address. We do this to try and prevent spoofing.
*/
InetAddress[]
arr =
InetAddress.
getAllByName0(
host,
check);
boolean
ok = false;
if(
arr != null) {
for(int
i = 0; !
ok &&
i <
arr.length;
i++) {
ok =
addr.
equals(
arr[
i]);
}
}
//XXX: if it looks a spoof just return the address?
if (!
ok) {
host =
addr.
getHostAddress();
return
host;
}
break;
} catch (
SecurityException e) {
host =
addr.
getHostAddress();
break;
} catch (
UnknownHostException e) {
host =
addr.
getHostAddress();
// let next provider resolve the hostname
}
}
return
host;
}
/**
* Returns the raw IP address of this {@code InetAddress}
* object. The result is in network byte order: the highest order
* byte of the address is in {@code getAddress()[0]}.
*
* @return the raw IP address of this object.
*/
public byte[]
getAddress() {
return null;
}
/**
* Returns the IP address string in textual presentation.
*
* @return the raw IP address in a string format.
* @since JDK1.0.2
*/
public
String getHostAddress() {
return null;
}
/**
* Returns a hashcode for this IP address.
*
* @return a hash code value for this IP address.
*/
public int
hashCode() {
return -1;
}
/**
* Compares this object against the specified object.
* The result is {@code true} if and only if the argument is
* not {@code null} and it represents the same IP address as
* this object.
* <p>
* Two instances of {@code InetAddress} represent the same IP
* address if the length of the byte arrays returned by
* {@code getAddress} is the same for both, and each of the
* array components is the same for the byte arrays.
*
* @param obj the object to compare against.
* @return {@code true} if the objects are the same;
* {@code false} otherwise.
* @see java.net.InetAddress#getAddress()
*/
public boolean
equals(
Object obj) {
return false;
}
/**
* Converts this IP address to a {@code String}. The
* string returned is of the form: hostname / literal IP
* address.
*
* If the host name is unresolved, no reverse name service lookup
* is performed. The hostname part will be represented by an empty string.
*
* @return a string representation of this IP address.
*/
public
String toString() {
String hostName =
holder().
getHostName();
return ((
hostName != null) ?
hostName : "")
+ "/" +
getHostAddress();
}
/*
* Cached addresses - our own litle nis, not!
*/
private static
Cache addressCache = new
Cache(
Cache.
Type.
Positive);
private static
Cache negativeCache = new
Cache(
Cache.
Type.
Negative);
private static boolean
addressCacheInit = false;
static
InetAddress[]
unknown_array; // put THIS in cache
static
InetAddressImpl impl;
private static final
HashMap<
String,
Void>
lookupTable = new
HashMap<>();
/**
* Represents a cache entry
*/
static final class
CacheEntry {
CacheEntry(
InetAddress[]
addresses, long
expiration) {
this.
addresses =
addresses;
this.
expiration =
expiration;
}
InetAddress[]
addresses;
long
expiration;
}
/**
* A cache that manages entries based on a policy specified
* at creation time.
*/
static final class
Cache {
private
LinkedHashMap<
String,
CacheEntry>
cache;
private
Type type;
enum
Type {Positive, Negative};
/**
* Create cache
*/
public
Cache(
Type type) {
this.
type =
type;
cache = new
LinkedHashMap<
String,
CacheEntry>();
}
private int
getPolicy() {
if (
type ==
Type.
Positive) {
return
InetAddressCachePolicy.
get();
} else {
return
InetAddressCachePolicy.
getNegative();
}
}
/**
* Add an entry to the cache. If there's already an
* entry then for this host then the entry will be
* replaced.
*/
public
Cache put(
String host,
InetAddress[]
addresses) {
int
policy =
getPolicy();
if (
policy ==
InetAddressCachePolicy.
NEVER) {
return this;
}
// purge any expired entries
if (
policy !=
InetAddressCachePolicy.
FOREVER) {
// As we iterate in insertion order we can
// terminate when a non-expired entry is found.
LinkedList<
String>
expired = new
LinkedList<>();
long
now =
System.
currentTimeMillis();
for (
String key :
cache.
keySet()) {
CacheEntry entry =
cache.
get(
key);
if (
entry.
expiration >= 0 &&
entry.
expiration <
now) {
expired.
add(
key);
} else {
break;
}
}
for (
String key :
expired) {
cache.
remove(
key);
}
}
// create new entry and add it to the cache
// -- as a HashMap replaces existing entries we
// don't need to explicitly check if there is
// already an entry for this host.
long
expiration;
if (
policy ==
InetAddressCachePolicy.
FOREVER) {
expiration = -1;
} else {
expiration =
System.
currentTimeMillis() + (
policy * 1000);
}
CacheEntry entry = new
CacheEntry(
addresses,
expiration);
cache.
put(
host,
entry);
return this;
}
/**
* Query the cache for the specific host. If found then
* return its CacheEntry, or null if not found.
*/
public
CacheEntry get(
String host) {
int
policy =
getPolicy();
if (
policy ==
InetAddressCachePolicy.
NEVER) {
return null;
}
CacheEntry entry =
cache.
get(
host);
// check if entry has expired
if (
entry != null &&
policy !=
InetAddressCachePolicy.
FOREVER) {
if (
entry.
expiration >= 0 &&
entry.
expiration <
System.
currentTimeMillis()) {
cache.
remove(
host);
entry = null;
}
}
return
entry;
}
}
/*
* Initialize cache and insert anyLocalAddress into the
* unknown array with no expiry.
*/
private static void
cacheInitIfNeeded() {
assert
Thread.
holdsLock(
addressCache);
if (
addressCacheInit) {
return;
}
unknown_array = new
InetAddress[1];
unknown_array[0] =
impl.
anyLocalAddress();
addressCache.
put(
impl.
anyLocalAddress().
getHostName(),
unknown_array);
addressCacheInit = true;
}
/*
* Cache the given hostname and addresses.
*/
private static void
cacheAddresses(
String hostname,
InetAddress[]
addresses,
boolean
success) {
hostname =
hostname.
toLowerCase();
synchronized (
addressCache) {
cacheInitIfNeeded();
if (
success) {
addressCache.
put(
hostname,
addresses);
} else {
negativeCache.
put(
hostname,
addresses);
}
}
}
/*
* Lookup hostname in cache (positive & negative cache). If
* found return addresses, null if not found.
*/
private static
InetAddress[]
getCachedAddresses(
String hostname) {
hostname =
hostname.
toLowerCase();
// search both positive & negative caches
synchronized (
addressCache) {
cacheInitIfNeeded();
CacheEntry entry =
addressCache.
get(
hostname);
if (
entry == null) {
entry =
negativeCache.
get(
hostname);
}
if (
entry != null) {
return
entry.
addresses;
}
}
// not found
return null;
}
private static
NameService createNSProvider(
String provider) {
if (
provider == null)
return null;
NameService nameService = null;
if (
provider.
equals("default")) {
// initialize the default name service
nameService = new
NameService() {
public
InetAddress[]
lookupAllHostAddr(
String host)
throws
UnknownHostException {
return
impl.
lookupAllHostAddr(
host);
}
public
String getHostByAddr(byte[]
addr)
throws
UnknownHostException {
return
impl.
getHostByAddr(
addr);
}
};
} else {
final
String providerName =
provider;
try {
nameService = java.security.
AccessController.
doPrivileged(
new java.security.
PrivilegedExceptionAction<
NameService>() {
public
NameService run() {
Iterator<
NameServiceDescriptor>
itr =
ServiceLoader.
load(
NameServiceDescriptor.class)
.
iterator();
while (
itr.
hasNext()) {
NameServiceDescriptor nsd =
itr.
next();
if (
providerName.
equalsIgnoreCase(
nsd.
getType()+","
+
nsd.
getProviderName())) {
try {
return
nsd.
createNameService();
} catch (
Exception e) {
e.
printStackTrace();
System.
err.
println(
"Cannot create name service:"
+
providerName+": " +
e);
}
}
}
return null;
}
}
);
} catch (java.security.
PrivilegedActionException e) {
}
}
return
nameService;
}
static {
// create the impl
impl =
InetAddressImplFactory.
create();
// get name service if provided and requested
String provider = null;;
String propPrefix = "sun.net.spi.nameservice.provider.";
int
n = 1;
nameServices = new
ArrayList<
NameService>();
provider =
AccessController.
doPrivileged(
new
GetPropertyAction(
propPrefix +
n));
while (
provider != null) {
NameService ns =
createNSProvider(
provider);
if (
ns != null)
nameServices.
add(
ns);
n++;
provider =
AccessController.
doPrivileged(
new
GetPropertyAction(
propPrefix +
n));
}
// if not designate any name services provider,
// create a default one
if (
nameServices.
size() == 0) {
NameService ns =
createNSProvider("default");
nameServices.
add(
ns);
}
}
/**
* Creates an InetAddress based on the provided host name and IP address.
* No name service is checked for the validity of the address.
*
* <p> The host name can either be a machine name, such as
* "{@code java.sun.com}", or a textual representation of its IP
* address.
* <p> No validity checking is done on the host name either.
*
* <p> If addr specifies an IPv4 address an instance of Inet4Address
* will be returned; otherwise, an instance of Inet6Address
* will be returned.
*
* <p> IPv4 address byte array must be 4 bytes long and IPv6 byte array
* must be 16 bytes long
*
* @param host the specified host
* @param addr the raw IP address in network byte order
* @return an InetAddress object created from the raw IP address.
* @exception UnknownHostException if IP address is of illegal length
* @since 1.4
*/
public static
InetAddress getByAddress(
String host, byte[]
addr)
throws
UnknownHostException {
if (
host != null &&
host.
length() > 0 &&
host.
charAt(0) == '[') {
if (
host.
charAt(
host.
length()-1) == ']') {
host =
host.
substring(1,
host.
length() -1);
}
}
if (
addr != null) {
if (
addr.length ==
Inet4Address.
INADDRSZ) {
return new
Inet4Address(
host,
addr);
} else if (
addr.length ==
Inet6Address.
INADDRSZ) {
byte[]
newAddr
=
IPAddressUtil.
convertFromIPv4MappedAddress(
addr);
if (
newAddr != null) {
return new
Inet4Address(
host,
newAddr);
} else {
return new
Inet6Address(
host,
addr);
}
}
}
throw new
UnknownHostException("addr is of illegal length");
}
/**
* Determines the IP address of a host, given the host's name.
*
* <p> The host name can either be a machine name, such as
* "{@code java.sun.com}", or a textual representation of its
* IP address. If a literal IP address is supplied, only the
* validity of the address format is checked.
*
* <p> For {@code host} specified in literal IPv6 address,
* either the form defined in RFC 2732 or the literal IPv6 address
* format defined in RFC 2373 is accepted. IPv6 scoped addresses are also
* supported. See <a href="Inet6Address.html#scoped">here</a> for a description of IPv6
* scoped addresses.
*
* <p> If the host is {@code null} then an {@code InetAddress}
* representing an address of the loopback interface is returned.
* See <a href="http://www.ietf.org/rfc/rfc3330.txt">RFC 3330</a>
* section 2 and <a href="http://www.ietf.org/rfc/rfc2373.txt">RFC 2373</a>
* section 2.5.3. </p>
*
* @param host the specified host, or {@code null}.
* @return an IP address for the given host name.
* @exception UnknownHostException if no IP address for the
* {@code host} could be found, or if a scope_id was specified
* for a global IPv6 address.
* @exception SecurityException if a security manager exists
* and its checkConnect method doesn't allow the operation
*/
public static
InetAddress getByName(
String host)
throws
UnknownHostException {
return
InetAddress.
getAllByName(
host)[0];
}
// called from deployment cache manager
private static
InetAddress getByName(
String host,
InetAddress reqAddr)
throws
UnknownHostException {
return
InetAddress.
getAllByName(
host,
reqAddr)[0];
}
/**
* Given the name of a host, returns an array of its IP addresses,
* based on the configured name service on the system.
*
* <p> The host name can either be a machine name, such as
* "{@code java.sun.com}", or a textual representation of its IP
* address. If a literal IP address is supplied, only the
* validity of the address format is checked.
*
* <p> For {@code host} specified in <i>literal IPv6 address</i>,
* either the form defined in RFC 2732 or the literal IPv6 address
* format defined in RFC 2373 is accepted. A literal IPv6 address may
* also be qualified by appending a scoped zone identifier or scope_id.
* The syntax and usage of scope_ids is described
* <a href="Inet6Address.html#scoped">here</a>.
* <p> If the host is {@code null} then an {@code InetAddress}
* representing an address of the loopback interface is returned.
* See <a href="http://www.ietf.org/rfc/rfc3330.txt">RFC 3330</a>
* section 2 and <a href="http://www.ietf.org/rfc/rfc2373.txt">RFC 2373</a>
* section 2.5.3. </p>
*
* <p> If there is a security manager and {@code host} is not
* null and {@code host.length() } is not equal to zero, the
* security manager's
* {@code checkConnect} method is called
* with the hostname and {@code -1}
* as its arguments to see if the operation is allowed.
*
* @param host the name of the host, or {@code null}.
* @return an array of all the IP addresses for a given host name.
*
* @exception UnknownHostException if no IP address for the
* {@code host} could be found, or if a scope_id was specified
* for a global IPv6 address.
* @exception SecurityException if a security manager exists and its
* {@code checkConnect} method doesn't allow the operation.
*
* @see SecurityManager#checkConnect
*/
public static
InetAddress[]
getAllByName(
String host)
throws
UnknownHostException {
return
getAllByName(
host, null);
}
private static
InetAddress[]
getAllByName(
String host,
InetAddress reqAddr)
throws
UnknownHostException {
if (
host == null ||
host.
length() == 0) {
InetAddress[]
ret = new
InetAddress[1];
ret[0] =
impl.
loopbackAddress();
return
ret;
}
boolean
ipv6Expected = false;
if (
host.
charAt(0) == '[') {
// This is supposed to be an IPv6 literal
if (
host.
length() > 2 &&
host.
charAt(
host.
length()-1) == ']') {
host =
host.
substring(1,
host.
length() -1);
ipv6Expected = true;
} else {
// This was supposed to be a IPv6 address, but it's not!
throw new
UnknownHostException(
host + ": invalid IPv6 address");
}
}
// if host is an IP address, we won't do further lookup
if (
Character.
digit(
host.
charAt(0), 16) != -1
|| (
host.
charAt(0) == ':')) {
byte[]
addr = null;
int
numericZone = -1;
String ifname = null;
// see if it is IPv4 address
addr =
IPAddressUtil.
textToNumericFormatV4(
host);
if (
addr == null) {
// This is supposed to be an IPv6 literal
// Check if a numeric or string zone id is present
int
pos;
if ((
pos=
host.
indexOf ("%")) != -1) {
numericZone =
checkNumericZone (
host);
if (
numericZone == -1) { /* remainder of string must be an ifname */
ifname =
host.
substring (
pos+1);
}
}
if ((
addr =
IPAddressUtil.
textToNumericFormatV6(
host)) == null &&
host.
contains(":")) {
throw new
UnknownHostException(
host + ": invalid IPv6 address");
}
} else if (
ipv6Expected) {
// Means an IPv4 litteral between brackets!
throw new
UnknownHostException("["+
host+"]");
}
InetAddress[]
ret = new
InetAddress[1];
if(
addr != null) {
if (
addr.length ==
Inet4Address.
INADDRSZ) {
ret[0] = new
Inet4Address(null,
addr);
} else {
if (
ifname != null) {
ret[0] = new
Inet6Address(null,
addr,
ifname);
} else {
ret[0] = new
Inet6Address(null,
addr,
numericZone);
}
}
return
ret;
}
} else if (
ipv6Expected) {
// We were expecting an IPv6 Litteral, but got something else
throw new
UnknownHostException("["+
host+"]");
}
return
getAllByName0(
host,
reqAddr, true);
}
/**
* Returns the loopback address.
* <p>
* The InetAddress returned will represent the IPv4
* loopback address, 127.0.0.1, or the IPv6 loopback
* address, ::1. The IPv4 loopback address returned
* is only one of many in the form 127.*.*.*
*
* @return the InetAddress loopback instance.
* @since 1.7
*/
public static
InetAddress getLoopbackAddress() {
return
impl.
loopbackAddress();
}
/**
* check if the literal address string has %nn appended
* returns -1 if not, or the numeric value otherwise.
*
* %nn may also be a string that represents the displayName of
* a currently available NetworkInterface.
*/
private static int
checkNumericZone (
String s) throws
UnknownHostException {
int
percent =
s.
indexOf ('%');
int
slen =
s.
length();
int
digit,
zone=0;
if (
percent == -1) {
return -1;
}
for (int
i=
percent+1;
i<
slen;
i++) {
char
c =
s.
charAt(
i);
if (
c == ']') {
if (
i ==
percent+1) {
/* empty per-cent field */
return -1;
}
break;
}
if ((
digit =
Character.
digit (
c, 10)) < 0) {
return -1;
}
zone = (
zone * 10) +
digit;
}
return
zone;
}
private static
InetAddress[]
getAllByName0 (
String host)
throws
UnknownHostException
{
return
getAllByName0(
host, true);
}
/**
* package private so SocketPermission can call it
*/
static
InetAddress[]
getAllByName0 (
String host, boolean
check)
throws
UnknownHostException {
return
getAllByName0 (
host, null,
check);
}
private static
InetAddress[]
getAllByName0 (
String host,
InetAddress reqAddr, boolean
check)
throws
UnknownHostException {
/* If it gets here it is presumed to be a hostname */
/* Cache.get can return: null, unknownAddress, or InetAddress[] */
/* make sure the connection to the host is allowed, before we
* give out a hostname
*/
if (
check) {
SecurityManager security =
System.
getSecurityManager();
if (
security != null) {
security.
checkConnect(
host, -1);
}
}
InetAddress[]
addresses =
getCachedAddresses(
host);
/* If no entry in cache, then do the host lookup */
if (
addresses == null) {
addresses =
getAddressesFromNameService(
host,
reqAddr);
}
if (
addresses ==
unknown_array)
throw new
UnknownHostException(
host);
return
addresses.
clone();
}
private static
InetAddress[]
getAddressesFromNameService(
String host,
InetAddress reqAddr)
throws
UnknownHostException
{
InetAddress[]
addresses = null;
boolean
success = false;
UnknownHostException ex = null;
// Check whether the host is in the lookupTable.
// 1) If the host isn't in the lookupTable when
// checkLookupTable() is called, checkLookupTable()
// would add the host in the lookupTable and
// return null. So we will do the lookup.
// 2) If the host is in the lookupTable when
// checkLookupTable() is called, the current thread
// would be blocked until the host is removed
// from the lookupTable. Then this thread
// should try to look up the addressCache.
// i) if it found the addresses in the
// addressCache, checkLookupTable() would
// return the addresses.
// ii) if it didn't find the addresses in the
// addressCache for any reason,
// it should add the host in the
// lookupTable and return null so the
// following code would do a lookup itself.
if ((
addresses =
checkLookupTable(
host)) == null) {
try {
// This is the first thread which looks up the addresses
// this host or the cache entry for this host has been
// expired so this thread should do the lookup.
for (
NameService nameService :
nameServices) {
try {
/*
* Do not put the call to lookup() inside the
* constructor. if you do you will still be
* allocating space when the lookup fails.
*/
addresses =
nameService.
lookupAllHostAddr(
host);
success = true;
break;
} catch (
UnknownHostException uhe) {
if (
host.
equalsIgnoreCase("localhost")) {
InetAddress[]
local = new
InetAddress[] {
impl.
loopbackAddress() };
addresses =
local;
success = true;
break;
}
else {
addresses =
unknown_array;
success = false;
ex =
uhe;
}
}
}
// More to do?
if (
reqAddr != null &&
addresses.length > 1 && !
addresses[0].
equals(
reqAddr)) {
// Find it?
int
i = 1;
for (;
i <
addresses.length;
i++) {
if (
addresses[
i].
equals(
reqAddr)) {
break;
}
}
// Rotate
if (
i <
addresses.length) {
InetAddress tmp,
tmp2 =
reqAddr;
for (int
j = 0;
j <
i;
j++) {
tmp =
addresses[
j];
addresses[
j] =
tmp2;
tmp2 =
tmp;
}
addresses[
i] =
tmp2;
}
}
// Cache the address.
cacheAddresses(
host,
addresses,
success);
if (!
success &&
ex != null)
throw
ex;
} finally {
// Delete host from the lookupTable and notify
// all threads waiting on the lookupTable monitor.
updateLookupTable(
host);
}
}
return
addresses;
}
private static
InetAddress[]
checkLookupTable(
String host) {
synchronized (
lookupTable) {
// If the host isn't in the lookupTable, add it in the
// lookuptable and return null. The caller should do
// the lookup.
if (
lookupTable.
containsKey(
host) == false) {
lookupTable.
put(
host, null);
return null;
}
// If the host is in the lookupTable, it means that another
// thread is trying to look up the addresses of this host.
// This thread should wait.
while (
lookupTable.
containsKey(
host)) {
try {
lookupTable.
wait();
} catch (
InterruptedException e) {
}
}
}
// The other thread has finished looking up the addresses of
// the host. This thread should retry to get the addresses
// from the addressCache. If it doesn't get the addresses from
// the cache, it will try to look up the addresses itself.
InetAddress[]
addresses =
getCachedAddresses(
host);
if (
addresses == null) {
synchronized (
lookupTable) {
lookupTable.
put(
host, null);
return null;
}
}
return
addresses;
}
private static void
updateLookupTable(
String host) {
synchronized (
lookupTable) {
lookupTable.
remove(
host);
lookupTable.
notifyAll();
}
}
/**
* Returns an {@code InetAddress} object given the raw IP address .
* The argument is in network byte order: the highest order
* byte of the address is in {@code getAddress()[0]}.
*
* <p> This method doesn't block, i.e. no reverse name service lookup
* is performed.
*
* <p> IPv4 address byte array must be 4 bytes long and IPv6 byte array
* must be 16 bytes long
*
* @param addr the raw IP address in network byte order
* @return an InetAddress object created from the raw IP address.
* @exception UnknownHostException if IP address is of illegal length
* @since 1.4
*/
public static
InetAddress getByAddress(byte[]
addr)
throws
UnknownHostException {
return
getByAddress(null,
addr);
}
private static
InetAddress cachedLocalHost = null;
private static long
cacheTime = 0;
private static final long
maxCacheTime = 5000L;
private static final
Object cacheLock = new
Object();
/**
* Returns the address of the local host. This is achieved by retrieving
* the name of the host from the system, then resolving that name into
* an {@code InetAddress}.
*
* <P>Note: The resolved address may be cached for a short period of time.
* </P>
*
* <p>If there is a security manager, its
* {@code checkConnect} method is called
* with the local host name and {@code -1}
* as its arguments to see if the operation is allowed.
* If the operation is not allowed, an InetAddress representing
* the loopback address is returned.
*
* @return the address of the local host.
*
* @exception UnknownHostException if the local host name could not
* be resolved into an address.
*
* @see SecurityManager#checkConnect
* @see java.net.InetAddress#getByName(java.lang.String)
*/
public static
InetAddress getLocalHost() throws
UnknownHostException {
SecurityManager security =
System.
getSecurityManager();
try {
String local =
impl.
getLocalHostName();
if (
security != null) {
security.
checkConnect(
local, -1);
}
if (
local.
equals("localhost")) {
return
impl.
loopbackAddress();
}
InetAddress ret = null;
synchronized (
cacheLock) {
long
now =
System.
currentTimeMillis();
if (
cachedLocalHost != null) {
if ((
now -
cacheTime) <
maxCacheTime) // Less than 5s old?
ret =
cachedLocalHost;
else
cachedLocalHost = null;
}
// we are calling getAddressesFromNameService directly
// to avoid getting localHost from cache
if (
ret == null) {
InetAddress[]
localAddrs;
try {
localAddrs =
InetAddress.
getAddressesFromNameService(
local, null);
} catch (
UnknownHostException uhe) {
// Rethrow with a more informative error message.
UnknownHostException uhe2 =
new
UnknownHostException(
local + ": " +
uhe.
getMessage());
uhe2.
initCause(
uhe);
throw
uhe2;
}
cachedLocalHost =
localAddrs[0];
cacheTime =
now;
ret =
localAddrs[0];
}
}
return
ret;
} catch (java.lang.
SecurityException e) {
return
impl.
loopbackAddress();
}
}
/**
* Perform class load-time initializations.
*/
private static native void
init();
/*
* Returns the InetAddress representing anyLocalAddress
* (typically 0.0.0.0 or ::0)
*/
static
InetAddress anyLocalAddress() {
return
impl.
anyLocalAddress();
}
/*
* Load and instantiate an underlying impl class
*/
static
InetAddressImpl loadImpl(
String implName) {
Object impl = null;
/*
* Property "impl.prefix" will be prepended to the classname
* of the implementation object we instantiate, to which we
* delegate the real work (like native methods). This
* property can vary across implementations of the java.
* classes. The default is an empty String "".
*/
String prefix =
AccessController.
doPrivileged(
new
GetPropertyAction("impl.prefix", ""));
try {
impl =
Class.
forName("java.net." +
prefix +
implName).
newInstance();
} catch (
ClassNotFoundException e) {
System.
err.
println("Class not found: java.net." +
prefix +
implName + ":\ncheck impl.prefix property " +
"in your properties file.");
} catch (
InstantiationException e) {
System.
err.
println("Could not instantiate: java.net." +
prefix +
implName + ":\ncheck impl.prefix property " +
"in your properties file.");
} catch (
IllegalAccessException e) {
System.
err.
println("Cannot access class: java.net." +
prefix +
implName + ":\ncheck impl.prefix property " +
"in your properties file.");
}
if (
impl == null) {
try {
impl =
Class.
forName(
implName).
newInstance();
} catch (
Exception e) {
throw new
Error("System property impl.prefix incorrect");
}
}
return (
InetAddressImpl)
impl;
}
private void
readObjectNoData (
ObjectInputStream s) throws
IOException,
ClassNotFoundException {
if (
getClass().
getClassLoader() != null) {
throw new
SecurityException ("invalid address type");
}
}
private static final long
FIELDS_OFFSET;
private static final sun.misc.
Unsafe UNSAFE;
static {
try {
sun.misc.
Unsafe unsafe = sun.misc.
Unsafe.
getUnsafe();
FIELDS_OFFSET =
unsafe.
objectFieldOffset(
InetAddress.class.
getDeclaredField("holder")
);
UNSAFE =
unsafe;
} catch (
ReflectiveOperationException e) {
throw new
Error(
e);
}
}
private void
readObject (
ObjectInputStream s) throws
IOException,
ClassNotFoundException {
if (
getClass().
getClassLoader() != null) {
throw new
SecurityException ("invalid address type");
}
GetField gf =
s.
readFields();
String host = (
String)
gf.
get("hostName", null);
int
address =
gf.
get("address", 0);
int
family =
gf.
get("family", 0);
if (
family !=
IPv4 &&
family !=
IPv6) {
throw new
InvalidObjectException("invalid address family type: " +
family);
}
InetAddressHolder h = new
InetAddressHolder(
host,
address,
family);
UNSAFE.
putObject(this,
FIELDS_OFFSET,
h);
}
/* needed because the serializable fields no longer exist */
/**
* @serialField hostName String
* @serialField address int
* @serialField family int
*/
private static final
ObjectStreamField[]
serialPersistentFields = {
new
ObjectStreamField("hostName",
String.class),
new
ObjectStreamField("address", int.class),
new
ObjectStreamField("family", int.class),
};
private void
writeObject (
ObjectOutputStream s) throws
IOException {
if (
getClass().
getClassLoader() != null) {
throw new
SecurityException ("invalid address type");
}
PutField pf =
s.
putFields();
pf.
put("hostName",
holder().
getHostName());
pf.
put("address",
holder().
getAddress());
pf.
put("family",
holder().
getFamily());
s.
writeFields();
}
}
/*
* Simple factory to create the impl
*/
class
InetAddressImplFactory {
static
InetAddressImpl create() {
return
InetAddress.
loadImpl(
isIPv6Supported() ?
"Inet6AddressImpl" : "Inet4AddressImpl");
}
static native boolean
isIPv6Supported();
}