java/6 : java/net/NetworkInterface.java

NetworkInterface
https://openjdk.java.net/
GPLv2 + Classpath Exception
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package java.net;

import java.net.SocketException;
import java.util.Enumeration;
import java.util.NoSuchElementException;
import sun.security.action.*;
import java.security.AccessController;

This class represents a Network Interface made up of a name,
and a list of IP addresses assigned to this interface.
It is used to identify the local interface on which a multicast group
is joined.
Interfaces are normally known by names such as "le0".
Since: 1.4/**
 * This class represents a Network Interface made up of a name,
 * and a list of IP addresses assigned to this interface.
 * It is used to identify the local interface on which a multicast group
 * is joined.
 *
 * Interfaces are normally known by names such as "le0".
 *
 * @since 1.4
 */
public final class NetworkInterface {
    private String name;
    private String displayName;
    private int index;
    private InetAddress addrs[];
    private InterfaceAddress bindings[];
    private NetworkInterface childs[];
    private NetworkInterface parent = null;
    private boolean virtual = false;

    static {
        AccessController.doPrivileged(new LoadLibraryAction("net"));
        init();
    }

    Returns an NetworkInterface object with index set to 0 and name to null.
Setting such an interface on a MulticastSocket will cause the
kernel to choose one interface for sending multicast packets.
/**
     * Returns an NetworkInterface object with index set to 0 and name to null.
     * Setting such an interface on a MulticastSocket will cause the
     * kernel to choose one interface for sending multicast packets.
     *
     */
    NetworkInterface() {
    }

    NetworkInterface(String name, int index, InetAddress[] addrs) {
        this.name = name;
        this.index = index;
        this.addrs = addrs;
    }

    Get the name of this network interface.
Returns: the name of this network interface/**
     * Get the name of this network interface.
     *
     * @return the name of this network interface
     */
    public String getName() {
            return name;
    }

    Convenience method to return an Enumeration with all or a
subset of the InetAddresses bound to this network interface.

If there is a security manager, its checkConnect
method is called for each InetAddress. Only InetAddresses where
the checkConnect doesn't throw a SecurityException
will be returned in the Enumeration.
Returns: an Enumeration object with all or a subset of the InetAddresses
bound to this network interface/**
     * Convenience method to return an Enumeration with all or a
     * subset of the InetAddresses bound to this network interface.
     * <p>
     * If there is a security manager, its <code>checkConnect</code>
     * method is called for each InetAddress. Only InetAddresses where
     * the <code>checkConnect</code> doesn't throw a SecurityException
     * will be returned in the Enumeration.
     * @return an Enumeration object with all or a subset of the InetAddresses
     * bound to this network interface
     */
    public Enumeration<InetAddress> getInetAddresses() {

        class checkedAddresses implements Enumeration<InetAddress> {

            private int i=0, count=0;
            private InetAddress local_addrs[];

            checkedAddresses() {
                local_addrs = new InetAddress[addrs.length];

                SecurityManager sec = System.getSecurityManager();
                for (int j=0; j<addrs.length; j++) {
                    try {
                        if (sec != null) {
                            sec.checkConnect(addrs[j].getHostAddress(), -1);
                        }
                        local_addrs[count++] = addrs[j];
                    } catch (SecurityException e) { }
                }

            }

            public InetAddress nextElement() {
                if (i < count) {
                    return local_addrs[i++];
                } else {
                    throw new NoSuchElementException();
                }
            }

            public boolean hasMoreElements() {
                return (i < count);
            }
        }
        return new checkedAddresses();

    }

    Get a List of all or a subset of the InterfaceAddresses
of this network interface.

If there is a security manager, its checkConnect
method is called with the InetAddress for each InterfaceAddress.
Only InterfaceAddresses where the checkConnect doesn't throw
a SecurityException will be returned in the List.
Returns: a List object with all or a subset of the
        InterfaceAddresss of this network interface
Since: 1.6/**
     * Get a List of all or a subset of the <code>InterfaceAddresses</code>
     * of this network interface.
     * <p>
     * If there is a security manager, its <code>checkConnect</code>
     * method is called with the InetAddress for each InterfaceAddress.
     * Only InterfaceAddresses where the <code>checkConnect</code> doesn't throw
     * a SecurityException will be returned in the List.
     *
     * @return a <code>List</code> object with all or a subset of the
     *         InterfaceAddresss of this network interface
     * @since 1.6
     */
    public java.util.List<InterfaceAddress> getInterfaceAddresses() {
        java.util.List<InterfaceAddress> lst = new java.util.ArrayList<InterfaceAddress>(1);
        SecurityManager sec = System.getSecurityManager();
        for (int j=0; j<bindings.length; j++) {
            try {
                if (sec != null) {
                    sec.checkConnect(bindings[j].getAddress().getHostAddress(), -1);
                }
                lst.add(bindings[j]);
            } catch (SecurityException e) { }
        }
        return lst;
    }

    Get an Enumeration with all the subinterfaces (also known as virtual
interfaces) attached to this network interface.

For instance eth0:1 will be a subinterface to eth0.
Returns: an Enumeration object with all of the subinterfaces
of this network interface
Since: 1.6/**
     * Get an Enumeration with all the subinterfaces (also known as virtual
     * interfaces) attached to this network interface.
     * <p>
     * For instance eth0:1 will be a subinterface to eth0.
     *
     * @return an Enumeration object with all of the subinterfaces
     * of this network interface
     * @since 1.6
     */
    public Enumeration<NetworkInterface> getSubInterfaces() {
        class subIFs implements Enumeration<NetworkInterface> {

            private int i=0;

            subIFs() {
            }

            public NetworkInterface nextElement() {
                if (i < childs.length) {
                    return childs[i++];
                } else {
                    throw new NoSuchElementException();
                }
            }

            public boolean hasMoreElements() {
                return (i < childs.length);
            }
        }
        return new subIFs();

    }

    Returns the parent NetworkInterface of this interface if this is
a subinterface, or null if it is a physical
(non virtual) interface or has no parent.
Returns: The NetworkInterface this interface is attached to.
Since: 1.6/**
     * Returns the parent NetworkInterface of this interface if this is
     * a subinterface, or <code>null</code> if it is a physical
     * (non virtual) interface or has no parent.
     *
     * @return The <code>NetworkInterface</code> this interface is attached to.
     * @since 1.6
     */
    public NetworkInterface getParent() {
        return parent;
    }

    Get the index of this network interface.
Returns: the index of this network interface/**
     * Get the index of this network interface.
     *
     * @return the index of this network interface
     */
    int getIndex() {
        return index;
    }

    Get the display name of this network interface.
A display name is a human readable String describing the network
device.
Returns: the display name of this network interface,
        or null if no display name is available./**
     * Get the display name of this network interface.
     * A display name is a human readable String describing the network
     * device.
     *
     * @return the display name of this network interface,
     *         or null if no display name is available.
     */
    public String getDisplayName() {
        return displayName;
    }

    Searches for the network interface with the specified name.
Params: name – 
         The name of the network interface.
Throws: SocketException – 
         If an I/O error occurs.
NullPointerException – 
         If the specified name is null.
Returns:  A NetworkInterface with the specified name,
         or null if there is no network interface
         with the specified name./**
     * Searches for the network interface with the specified name.
     *
     * @param   name
     *          The name of the network interface.
     *
     * @return  A <tt>NetworkInterface</tt> with the specified name,
     *          or <tt>null</tt> if there is no network interface
     *          with the specified name.
     *
     * @throws  SocketException
     *          If an I/O error occurs.
     *
     * @throws  NullPointerException
     *          If the specified name is <tt>null</tt>.
     */
    public static NetworkInterface getByName(String name) throws SocketException {
        if (name == null)
            throw new NullPointerException();
        return getByName0(name);
    }

    Get a network interface given its index.
Params: index – an integer, the index of the interface
Throws: SocketException –  if an I/O error occurs.
Returns: the NetworkInterface obtained from its index/**
     * Get a network interface given its index.
     *
     * @param index an integer, the index of the interface
     * @return the NetworkInterface obtained from its index
     * @exception  SocketException  if an I/O error occurs.
     */
    native static NetworkInterface getByIndex(int index)
        throws SocketException;

    Convenience method to search for a network interface that
has the specified Internet Protocol (IP) address bound to
it.

If the specified IP address is bound to multiple network
interfaces it is not defined which network interface is
returned.
Params: addr – 
         The InetAddress to search with.
Throws: SocketException – 
         If an I/O error occurs.
NullPointerException – 
         If the specified address is null.
Returns:  A NetworkInterface
         or null if there is no network interface
         with the specified IP address./**
     * Convenience method to search for a network interface that
     * has the specified Internet Protocol (IP) address bound to
     * it.
     * <p>
     * If the specified IP address is bound to multiple network
     * interfaces it is not defined which network interface is
     * returned.
     *
     * @param   addr
     *          The <tt>InetAddress</tt> to search with.
     *
     * @return  A <tt>NetworkInterface</tt>
     *          or <tt>null</tt> if there is no network interface
     *          with the specified IP address.
     *
     * @throws  SocketException
     *          If an I/O error occurs.
     *
     * @throws  NullPointerException
     *          If the specified address is <tt>null</tt>.
     */
    public static NetworkInterface getByInetAddress(InetAddress addr) throws SocketException {
        if (addr == null) {
            throw new NullPointerException();
        }
        if (addr instanceof Inet4Address) {
            Inet4Address inet4Address = (Inet4Address) addr;
            if (inet4Address.holder.family != InetAddress.IPv4) {
                throw new IllegalArgumentException("invalid family type: "
                        + inet4Address.holder.family);
            }
        } else if (addr instanceof Inet6Address) {
            Inet6Address inet6Address = (Inet6Address) addr;
            if (inet6Address.holder.family != InetAddress.IPv6) {
                throw new IllegalArgumentException("invalid family type: "
                        + inet6Address.holder.family);
            }
        } else {
            throw new IllegalArgumentException("invalid address type: " + addr);
        }
        return getByInetAddress0(addr);
    }

    Returns all the interfaces on this machine. Returns null if no
network interfaces could be found on this machine.
NOTE: can use getNetworkInterfaces()+getInetAddresses()
      to obtain all IP addresses for this node
Throws: SocketException –  if an I/O error occurs.
Returns: an Enumeration of NetworkInterfaces found on this machine/**
     * Returns all the interfaces on this machine. Returns null if no
     * network interfaces could be found on this machine.
     *
     * NOTE: can use getNetworkInterfaces()+getInetAddresses()
     *       to obtain all IP addresses for this node
     *
     * @return an Enumeration of NetworkInterfaces found on this machine
     * @exception  SocketException  if an I/O error occurs.
     */

    public static Enumeration<NetworkInterface> getNetworkInterfaces()
        throws SocketException {
        final NetworkInterface[] netifs = getAll();

        // specified to return null if no network interfaces
        if (netifs == null)
            return null;

        return new Enumeration<NetworkInterface>() {
            private int i = 0;
            public NetworkInterface nextElement() {
                if (netifs != null && i < netifs.length) {
                    NetworkInterface netif = netifs[i++];
                    return netif;
                } else {
                    throw new NoSuchElementException();
                }
            }

            public boolean hasMoreElements() {
                return (netifs != null && i < netifs.length);
            }
        };
    }

    private native static NetworkInterface[] getAll()
        throws SocketException;

    private native static NetworkInterface getByName0(String name)
        throws SocketException;

    private native static NetworkInterface getByInetAddress0(InetAddress addr)
        throws SocketException;

    Returns whether a network interface is up and running.
Throws: SocketException – if an I/O error occurs.
Returns:  true if the interface is up and running.
Since: 1.6/**
     * Returns whether a network interface is up and running.
     *
     * @return  <code>true</code> if the interface is up and running.
     * @exception       SocketException if an I/O error occurs.
     * @since 1.6
     */

    public boolean isUp() throws SocketException {
        return isUp0(name, index);
    }

    Returns whether a network interface is a loopback interface.
Throws: SocketException – if an I/O error occurs.
Returns:  true if the interface is a loopback interface.
Since: 1.6/**
     * Returns whether a network interface is a loopback interface.
     *
     * @return  <code>true</code> if the interface is a loopback interface.
     * @exception       SocketException if an I/O error occurs.
     * @since 1.6
     */

    public boolean isLoopback() throws SocketException {
        return isLoopback0(name, index);
    }

    Returns whether a network interface is a point to point interface.
A typical point to point interface would be a PPP connection through
a modem.
Throws: SocketException – if an I/O error occurs.
Returns:  true if the interface is a point to point
         interface.
Since: 1.6/**
     * Returns whether a network interface is a point to point interface.
     * A typical point to point interface would be a PPP connection through
     * a modem.
     *
     * @return  <code>true</code> if the interface is a point to point
     *          interface.
     * @exception       SocketException if an I/O error occurs.
     * @since 1.6
     */

    public boolean isPointToPoint() throws SocketException {
        return isP2P0(name, index);
    }

    Returns whether a network interface supports multicasting or not.
Throws: SocketException – if an I/O error occurs.
Returns:  true if the interface supports Multicasting.
Since: 1.6/**
     * Returns whether a network interface supports multicasting or not.
     *
     * @return  <code>true</code> if the interface supports Multicasting.
     * @exception       SocketException if an I/O error occurs.
     * @since 1.6
     */

    public boolean supportsMulticast() throws SocketException {
        return supportsMulticast0(name, index);
    }

    Returns the hardware address (usually MAC) of the interface if it
has one and if it can be accessed given the current privileges.
Throws: SocketException – if an I/O error occurs.
Returns:  a byte array containing the address or null if
         the address doesn't exist or is not accessible.
Since: 1.6/**
     * Returns the hardware address (usually MAC) of the interface if it
     * has one and if it can be accessed given the current privileges.
     *
     * @return  a byte array containing the address or <code>null</code> if
     *          the address doesn't exist or is not accessible.
     * @exception       SocketException if an I/O error occurs.
     * @since 1.6
     */
    public byte[] getHardwareAddress() throws SocketException {
        if (!getInetAddresses().hasMoreElements()) {
            // don't have connect permission to any local address
            return null;
        }
        for (InetAddress addr : addrs) {
            if (addr instanceof Inet4Address) {
                return getMacAddr0(((Inet4Address)addr).getAddress(), name, index);
            }
        }
        return getMacAddr0(null, name, index);
    }

    Returns the Maximum Transmission Unit (MTU) of this interface.
Throws: SocketException – if an I/O error occurs.
Returns: the value of the MTU for that interface.
Since: 1.6/**
     * Returns the Maximum Transmission Unit (MTU) of this interface.
     *
     * @return the value of the MTU for that interface.
     * @exception       SocketException if an I/O error occurs.
     * @since 1.6
     */
    public int getMTU() throws SocketException {
        return getMTU0(name, index);
    }

    Returns whether this interface is a virtual interface (also called
subinterface).
Virtual interfaces are, on some systems, interfaces created as a child
of a physical interface and given different settings (like address or
MTU). Usually the name of the interface will the name of the parent
followed by a colon (:) and a number identifying the child since there
can be several virtual interfaces attached to a single physical
interface.
Returns: true if this interface is a virtual interface.
Since: 1.6/**
     * Returns whether this interface is a virtual interface (also called
     * subinterface).
     * Virtual interfaces are, on some systems, interfaces created as a child
     * of a physical interface and given different settings (like address or
     * MTU). Usually the name of the interface will the name of the parent
     * followed by a colon (:) and a number identifying the child since there
     * can be several virtual interfaces attached to a single physical
     * interface.
     *
     * @return <code>true</code> if this interface is a virtual interface.
     * @since 1.6
     */
    public boolean isVirtual() {
        return virtual;
    }

    private native static long getSubnet0(String name, int ind) throws SocketException;
    private native static Inet4Address getBroadcast0(String name, int ind) throws SocketException;
    private native static boolean isUp0(String name, int ind) throws SocketException;
    private native static boolean isLoopback0(String name, int ind) throws SocketException;
    private native static boolean supportsMulticast0(String name, int ind) throws SocketException;
    private native static boolean isP2P0(String name, int ind) throws SocketException;
    private native static byte[] getMacAddr0(byte[] inAddr, String name, int ind) throws SocketException;
    private native static int getMTU0(String name, int ind) throws SocketException;

    Compares this object against the specified object.
The result is true if and only if the argument is
not null and it represents the same NetworkInterface
as this object.

Two instances of NetworkInterface represent the same
NetworkInterface if both name and addrs are the same for both.
Params: obj –   the object to compare against.
See Also: InetAddress.getAddress()
Returns:  true if the objects are the same;
         false otherwise./**
     * Compares this object against the specified object.
     * The result is <code>true</code> if and only if the argument is
     * not <code>null</code> and it represents the same NetworkInterface
     * as this object.
     * <p>
     * Two instances of <code>NetworkInterface</code> represent the same
     * NetworkInterface if both name and addrs are the same for both.
     *
     * @param   obj   the object to compare against.
     * @return  <code>true</code> if the objects are the same;
     *          <code>false</code> otherwise.
     * @see     java.net.InetAddress#getAddress()
     */
    public boolean equals(Object obj) {
        if ((obj == null) || !(obj instanceof NetworkInterface)) {
            return false;
        }
        NetworkInterface netIF = (NetworkInterface)obj;
        if (name != null ) {
            if (netIF.getName() != null) {
                if (!name.equals(netIF.getName())) {
                    return false;
                }
            } else {
                return false;
            }
        } else {
            if (netIF.getName() != null) {
                return false;
            }
        }
        Enumeration newAddrs = netIF.getInetAddresses();
        int i = 0;
        for (i = 0; newAddrs.hasMoreElements();newAddrs.nextElement(), i++);
        if (addrs == null) {
            if (i != 0) {
                return false;
            }
        } else {
            /*
             * Compare number of addresses (in the checked subset)
             */
            int count = 0;
            Enumeration e = getInetAddresses();
            for (; e.hasMoreElements(); count++) {
                e.nextElement();
            }
            if (i != count) {
                return false;
            }
        }
        newAddrs = netIF.getInetAddresses();
        for (; newAddrs.hasMoreElements();) {
            boolean equal = false;
            Enumeration thisAddrs = getInetAddresses();
            InetAddress newAddr = (InetAddress)newAddrs.nextElement();
            for (; thisAddrs.hasMoreElements();) {
                InetAddress thisAddr = (InetAddress)thisAddrs.nextElement();
                if (thisAddr.equals(newAddr)) {
                    equal = true;
                }
            }
            if (!equal) {
                return false;
            }
        }
        return true;
    }

    public int hashCode() {
        int count = name == null? 0: name.hashCode();
        Enumeration<InetAddress> addrs = getInetAddresses();
        while (addrs.hasMoreElements()) {
            count += addrs.nextElement().hashCode();
        }
        return count;
    }

    public String toString() {
        String result = "name:";
        result += name == null? "null": name;
        if (displayName != null) {
            result += " (" + displayName + ")";
        }
        return result;
    }

    private static native void init();
}
Returns:	a `List` object with all or a subset of the InterfaceAddresss of this network interface
Since:	1.6
Returns:	an Enumeration object with all of the subinterfaces of this network interface
Since:	1.6
Returns:	The `NetworkInterface` this interface is attached to.
Since:	1.6
Params:	name – The name of the network interface.
Throws:	SocketException – If an I/O error occurs. NullPointerException – If the specified name is `null`.
Returns:	A `NetworkInterface` with the specified name, or `null` if there is no network interface with the specified name.
Params:	index – an integer, the index of the interface
Throws:	SocketException – if an I/O error occurs.
Returns:	the NetworkInterface obtained from its index
Params:	addr – The `InetAddress` to search with.
Throws:	SocketException – If an I/O error occurs. NullPointerException – If the specified address is `null`.
Returns:	A `NetworkInterface` or `null` if there is no network interface with the specified IP address.
Returns:	`true` if this interface is a virtual interface.
Since:	1.6
Params:	obj – the object to compare against.
See Also:	InetAddress.getAddress()
Returns:	`true` if the objects are the same; `false` otherwise.
/

java/ 6/ java/net/NetworkInterface.java
