com.peterphi.std.net.IpHelper Maven / Gradle / Ivy
package com.peterphi.std.net;
import org.apache.log4j.Logger;
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.List;
import java.util.Vector;
/*
* Title: Ip Helper
*
* Description: IP address-related helper functions
*
* Copyright: Copyright (c) 2006-2009
*
*
*
*
* @version $Revision$
*/
public class IpHelper
{
private static final Logger log = Logger.getLogger(IpHelper.class);
/**
* The "Quad Zero" IPv4 address: 0.0.0.0
*/
public static final Inet4Address QUAD_ZERO = (Inet4Address) IpHelper.ntoa(0);
/**
* The IPv4 broadcast address: 255.255.255.255
*/
public static final Inet4Address BROADCAST_ADDRESS = (Inet4Address) IpHelper.ntoa(-1);
/**
* The IPv6 equivalent of the "Quad Zero" IPv4 address (0.0.0.0). This is the Inet6Address ::
*/
public static final Inet6Address IPV6_ZERO = (Inet6Address) IpHelper.stoa("::");
// Prevent instantiation
private IpHelper()
{
}
/**
* Gets the hostname of localhost
*
* @return String
*
* @throws RuntimeException
* When we cannot determine the local machine's hostname
*/
public static String getLocalhost() throws RuntimeException
{
String hostname = null;
try
{
InetAddress addr = InetAddress.getLocalHost();
hostname = addr.getHostName();
}
catch (UnknownHostException e)
{
throw new RuntimeException("[FileHelper] {getLocalhost}: Can't get local hostname");
}
return hostname;
}
/**
* Gets the local IP address
*
* @return String the local ip address's HostAddress
*
* @throws RuntimeException
* On error (eg. when the local host cannot be determined)
*/
public static String getLocalIp() throws RuntimeException
{
try
{
InetAddress addr = getLocalIpAddress();
return addr.getHostAddress();
}
catch (RuntimeException e)
{
throw new RuntimeException("[FileHelper] {getLocalIp}: Unable to find the local machine", e);
}
}
/**
* Returns the primary InetAddress of localhost
*
* @return InetAddress The InetAddress of the local host
*
* @throws RuntimeException
* On any error
* @since 1.0
*/
public static InetAddress getLocalIpAddress() throws RuntimeException
{
try
{
List ips = getLocalIpAddresses(false, true);
for (InetAddress ip : ips)
{
log.debug("[IpHelper] {getLocalIpAddress} Considering locality of " + ip.getHostAddress());
if (!ip.isAnyLocalAddress() && (ip instanceof Inet4Address))
{
// Ubuntu sets the unix hostname to resolve to 127.0.1.1; this is annoying so treat it as a loopback
if (!ip.getHostAddress().startsWith("127.0."))
{
log.debug("[IpHelper] {getLocalIpAddress} Found nonloopback IP: " + ip.getHostAddress());
return ip;
}
}
}
log.trace("[IpHelper] {getLocalIpAddress} Couldn't find a public IP in the ip (size " + ips.size() + ")");
return InetAddress.getLocalHost();
}
catch (UnknownHostException e)
{
throw new RuntimeException("[FileHelper] {getLocalIp}: Unable to acquire the current machine's InetAddress", e);
}
}
/**
* Returns the IP address associated with iface
*
* @param iface
* The interface name
*
* @return InetAddress The InetAddress of the interface (or null if none found)
*
* @throws RuntimeException
* On any error
* @since 1.0
*/
public static InetAddress getLocalIpAddress(String iface) throws RuntimeException
{
try
{
NetworkInterface nic = NetworkInterface.getByName(iface);
Enumeration ips = nic.getInetAddresses();
InetAddress firstIP = null;
while (ips != null && ips.hasMoreElements())
{
InetAddress ip = ips.nextElement();
if (firstIP == null)
firstIP = ip;
if (log.isDebugEnabled())
log.debug("[IpHelper] {getLocalIpAddress} Considering locality: " + ip.getHostAddress());
if (!ip.isAnyLocalAddress())
{
return ip;
}
}
// Return the first IP (or null if no IPs were returned)
return firstIP;
}
catch (SocketException e)
{
throw new RuntimeException("[IpHelper] {getLocalIpAddress}: Unable to acquire an IP", e);
}
}
/**
* Returns a list of local InetAddresses for this machine
*
* @return List[InetAddress] The list of IP addresses
*
* @throws RuntimeException
* If there is an error retrieving the InetAddresses
* @since 1.2
*/
public static List getLocalIpAddresses() throws RuntimeException
{
return getLocalIpAddresses(false, false);
}
/**
* Returns a list of local InetAddresses for this machine
*
* @param pruneSiteLocal
* boolean Set to true if site local (10/8, for example) addresses should be pruned
*
* @return List[InetAddress] The list of addresses
*
* @throws RuntimeException
* If there is an error retrieving the InetAddresses
* @since IpHelper.java 1.2
*/
public static List getLocalIpAddresses(boolean pruneSiteLocal) throws RuntimeException
{
return getLocalIpAddresses(pruneSiteLocal, false);
}
/**
* Returns a list of local InetAddresses for this machine
*
* @param pruneSiteLocal
* boolean Set to true if site local (10/8, for example) addresses should be pruned
* @param pruneDown
* boolean Set to true to prune out interfaces whose .isUp() return false
*
* @return List[InetAddress] The list of addresses
*
* @throws RuntimeException
* If there is an error retrieving the InetAddresses
* @since IpHelper.java 2007-11-22
*/
public static List getLocalIpAddresses(boolean pruneSiteLocal, boolean pruneDown) throws RuntimeException
{
try
{
Enumeration nics = NetworkInterface.getNetworkInterfaces();
List addresses = new Vector();
while (nics.hasMoreElements())
{
NetworkInterface iface = nics.nextElement();
Enumeration addrs = iface.getInetAddresses();
if (!pruneDown || iface.isUp())
{
while (addrs.hasMoreElements())
{
InetAddress addr = addrs.nextElement();
if (!addr.isLoopbackAddress() && !addr.isLinkLocalAddress())
{
if (!pruneSiteLocal || (pruneSiteLocal && !addr.isSiteLocalAddress()))
{
addresses.add(addr);
}
}
}
}
}
return addresses;
}
catch (SocketException e)
{
throw new RuntimeException(e.getMessage(), e);
}
}
/**
* Given an InetAddress, determines the MAC Address (hardware address) of the corresponding interface
*
* @param addr
* The IP address
*
* @return The MAC Address
*
* @throws SocketException
* If we couldn't get the interface
* @throws NoMacAddressException
* If the interface doesn't have a mac address specified
*/
public static String getMacForLocalIp(InetAddress addr) throws SocketException, NoMacAddressException, NoInterfaceException
{
return getMacFor(getInterfaceForLocalIp(addr));
}
/**
* Given a network interface, determines its mac address
*
* @param iface
* the interface
*
* @return The MAC address formatted in lower-case colon-delimited hexidecimal bytes (aa:ab:ac)
*
* @throws SocketException
* @throws NoMacAddressException
* If the interface doesn't have a mac address
*/
public static String getMacFor(NetworkInterface iface) throws SocketException, NoMacAddressException
{
assert (iface != null);
byte[] hwaddr = iface.getHardwareAddress();
if (hwaddr == null || hwaddr.length == 0)
{
throw new NoMacAddressException("Interface " + iface.getName() + " has no physical address specified.");
}
else
{
return physicalAddressToString(hwaddr);
}
}
/**
* Given a local IP address, returns the Interface it corresponds to
*
* @param addr
* The address
*
* @return The interface, or null if no interface corresponds to that address
*
* @throws SocketException
* @throws NoInterfaceException
* If there's no corresponding interface for the given IP
*/
public static NetworkInterface getInterfaceForLocalIp(InetAddress addr) throws SocketException, NoInterfaceException
{
assert (getLocalIpAddresses(false).contains(addr)) : "IP is not local";
NetworkInterface iface = NetworkInterface.getByInetAddress(addr);
if (iface != null)
return iface;
else
throw new NoInterfaceException("No network interface for IP: " + addr.toString());
}
private static final char[] hex = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
public static String physicalAddressToString(byte[] addr)
{
StringBuffer sb = new StringBuffer((addr.length * 3) - 1);
for (int i = 0;/* termination handled by final if */ ; ++i)
{
byte lo = (byte) (addr[i] & 0x0F);
byte hi = (byte) ((addr[i] & 0xF0) >>> 4);
sb.append(hex[hi]);
sb.append(hex[lo]);
if (i + 1 < addr.length)
{
sb.append(":");
}
else
{
break;
}
}
return sb.toString();
}
public static List getLocalIpAddresses(String ifaceName, boolean pruneSiteLocal) throws RuntimeException
{
try
{
NetworkInterface iface = NetworkInterface.getByName(ifaceName);
List addresses = new Vector();
Enumeration addrs = iface.getInetAddresses();
while (addrs.hasMoreElements())
{
InetAddress addr = addrs.nextElement();
if (!addr.isLoopbackAddress() || (pruneSiteLocal && !addr.isLinkLocalAddress()))
{
addresses.add(addr);
}
}
return addresses;
}
catch (SocketException e)
{
throw new RuntimeException(e.getMessage(), e);
}
}
/**
* Validates a netmask
*
* @param netmask
* String A netmask to test
*
* @return boolean True if it validates, otherwise false
*/
public static boolean isValidNetmask(String netmask)
{
try
{
return isValidNetmask(InetAddress.getByName(netmask));
}
catch (UnknownHostException e)
{
return false;
}
}
/**
* Validates a netmask
*
* @param netmask
* InetAddress A netmask to test
*
* @return boolean True if it validates, otherwise false
*/
public static boolean isValidNetmask(InetAddress netmask)
{
byte[] segments = netmask.getAddress();
return isValidNetmask(segments);
}
/**
* Validates a netmask
*
* @param segments
* byte[] A signed byte array whose binary values represent the address
*
* @return boolean True if valid, otherwise false
*/
public static boolean isValidNetmask(byte[] segments)
{
boolean mustBeZero = false;
for (int i = 0; i < segments.length; i++)
{
// Valid segments: 0, 128, 192, 224, 240, 248, 252, 254, 255
switch (segments[i])
{
case -1:
if (mustBeZero)
return false;
break;
case 0:
if (mustBeZero)
{
break;
}
case -2:
case -4:
case -8:
case -16:
case -32:
case -64:
case -128:
if (!mustBeZero)
mustBeZero = true;
else
{
return false;
}
break;
default:
return false;
}
}
return true;
}
/**
* Determines the prefix for a given netmask (ie. turns 255.255.255.0 into 24)
* Returns the number of contiguous 1 bits. Throws an IllegalArgumentException if the address is an invalid netmask
*
* @param netmask
* An IP netmask (eg. 255.255.252.0)
*
* @return A prefix length (the number of 1-bits in the netmask)
*
* @throws IllegalArgumentException
* if an invalid netmask is passed
*/
public static int netmaskToPrefix(InetAddress netmask)
{
byte[] mask = netmask.getAddress();
if (!isValidNetmask(mask))
throw new IllegalArgumentException("Not a valid netmask: " + netmask.getHostAddress());
int prefix = 0;
for (int i = 0; i < mask.length; i++)
{
// drops-through all lower cases to accumulate additions (so case: -2 becomes prefix += 7)
switch (mask[i])
{
case -1:
prefix += 8; // Hand-optimisation for a 255 segment (since it's so frequent)
break;
case -2:
prefix++;
case -4:
prefix++;
case -8:
prefix++;
case -16:
prefix++;
case -32:
prefix++;
case -64:
prefix++;
case -128:
prefix++;
default:
}
}
return prefix;
}
/**
* Turns an IPv4 prefix into a netmask
*
* @param prefix
*
* @return
*/
public static InetAddress prefixToNetmask(final int prefix)
{
return IpHelper.ntoa(prefixToMask(prefix));
}
/**
* Turns an IPv4 prefix into a numeric mask (the equivalent of running IpHelper.aton(prefixToNetmask(prefix)) but
* significantly faster)
*
* @param prefix
*
* @return
*/
public static int prefixToMask(final int prefix)
{
// We need to special-case zero because -1 << 32 != 0
if (prefix != 0)
return -1 << (32 - prefix);
else
return 0;
}
/**
* Determines if a specified address is a valid Cisco Wildcard (cisco's representation of a netmask)
*
* @param wildcard
* InetAddress
*
* @return boolean
*/
public static boolean isValidCiscoWildcard(InetAddress wildcard)
{
byte[] segments = wildcard.getAddress();
for (int i = 0; i < segments.length; i++)
{
assert (((byte) ~(byte) ~segments[i]) == segments[i]);
segments[i] = (byte) ~segments[i];
}
return isValidNetmask(segments);
}
/**
* Determines if a specified host or IP refers to the local machine
*
* @param addr
* String The host/IP
*
* @return boolean True if the input points to the local machine, otherwise false
*/
public static boolean isLocalAddress(String addr)
{
try
{
InetAddress iAddr = InetAddress.getByName(addr);
return isLocalAddress(iAddr);
}
catch (UnknownHostException e)
{
return false;
}
}
/**
* Determines if a specified host or IP refers to the local machine
*
* @param addr
* String The host/IP
*
* @return boolean True if the input points to the local machine, otherwise false Checks by enumerating the NetworkInterfaces
* available to Java.
*/
public static boolean isLocalAddress(final InetAddress addr)
{
if (addr.isLoopbackAddress())
{
return true;
}
try
{
Enumeration nics = NetworkInterface.getNetworkInterfaces();
while (nics.hasMoreElements())
{
Enumeration addrs = nics.nextElement().getInetAddresses();
while (addrs.hasMoreElements())
{
if (addrs.nextElement().equals(addr))
{
return true; // Search successful
}
}
}
}
catch (SocketException e)
{
log.debug(e.getMessage(), e);
}
log.debug("[FileHelper] {isLocalAddress} not local: " + addr.getHostAddress());
// Search failed
return false;
}
/**
* Parses an IP address, returning it as an InetAddress
* This method exists to prevent code which is handling valid IP addresses from having to catch UnknownHostException
* excessively (when there is often no choice but to totally fail out anyway)
*
* @param ip
* a valid IP address (IPv4 or IPv6)
*
* @return the resulting InetAddress for that ip; this is equivalent to calling InetAddress.getByName on the IP
* (but without having to catch UnknownHostException)
*
* @throws IllegalArgumentException
* if the IP address is invalid (eg. null, an empty string or otherwise not in the valid IP address format)
*/
public static InetAddress stoa(final String ip)
{
if (ip == null || ip.isEmpty())
throw new IllegalArgumentException("must pass a valid ip: null or empty strings are not valid IPs!");
try
{
return InetAddress.getByName(ip);
}
catch (UnknownHostException e)
{
throw new IllegalArgumentException("must pass a valid ip. Illegal input was: " + ip, e);
}
}
/**
* An equivalent of the C inet_aton function
*
* @param ip
*
* @return
*/
public static int aton(final String ip)
{
try
{
return aton(InetAddress.getByName(ip));
}
catch (UnknownHostException e)
{
throw new IllegalArgumentException("must pass a valid ip. Illegal input was: " + ip, e);
}
}
/**
* Converts an InetAddress to a numeric address only in the case of IPv4 (Inet4Address) addresses. Other
* addresses will result in an Error being thrown
*
* @param ip
*
* @return
*/
public static int aton(final InetAddress ip)
{
if (ip == null)
{
throw new Error("the result of aton(null) is undefined");
}
if (ip instanceof Inet4Address)
{
return aton((Inet4Address) ip);
}
else
{
throw new Error("int aton(InetAddress) does not function for " + ip.getClass());
}
}
/**
* Converts an InetAddress to a numeric address
*
* @param ip
*
* @return
*/
public static int aton(final Inet4Address ip)
{
return aton(ip.getAddress());
}
/**
* Converts an InetAddress' byte[] representation to a numeric address
* This only works for IPv4 (obviously)
*
* @param addr
*
* @return
*/
public static int aton(final byte[] addr)
{
int address = addr[3] & 0xFF;
address |= ((addr[2] << 8) & 0xFF00);
address |= ((addr[1] << 16) & 0xFF0000);
address |= ((addr[0] << 24) & 0xFF000000);
return address;
}
public static InetAddress ntoa(final byte[] addr)
{
try
{
if (addr.length == 4 || addr.length == 16)
{
return InetAddress.getByAddress(addr);
}
else
{
throw new IllegalArgumentException("a byte[] address for ntoa must be 4 bytes (ipv4) or 16 bytes (ipv6)");
}
}
catch (UnknownHostException e)
{
// will never be thrown since we check the length manually
throw new Error(e);
}
}
/**
* Converts numeric address to an InetAddress
*
* @param address
*
* @return
*/
public static InetAddress ntoa(final int address)
{
try
{
final byte[] addr = new byte[4];
addr[0] = (byte) ((address >>> 24) & 0xFF);
addr[1] = (byte) ((address >>> 16) & 0xFF);
addr[2] = (byte) ((address >>> 8) & 0xFF);
addr[3] = (byte) (address & 0xFF);
return InetAddress.getByAddress(addr);
}
catch (UnknownHostException e)
{
// will never be thrown
throw new Error(e);
}
}
/**
* Parses an IP address, throwing an {@link IllegalArgumentException} (rather than an {@link UnknownHostException}) if it is
* invalid
*
* @param ip
* the IP - must not be null or an empty string. should be a valid IP address (eg. 1.2.3.4)
*
* @return an InetAddress
*/
public static InetAddress parse(final String ip)
{
if (ip == null || ip.isEmpty())
throw new IllegalArgumentException("A null or empty string is not a valid IP address!");
try
{
return InetAddress.getByName(ip);
}
catch (Throwable t)
{
throw new IllegalArgumentException("Not a valid IP address: " + ip, t);
}
}
/**
* Determines whether a particular IP address is publicly routable on the internet
*
* @param addrIP
*
* @return
*
* @deprecated use isPubliclyRoutable(java.net.InetAddress)
*/
@Deprecated
public static boolean isPublicallyRoutable(final InetAddress addrIP)
{
return isPubliclyRoutable(addrIP);
}
/**
* Determines whether a particular IP address is publicly routable on the internet
*
* @param addrIP
*
* @return
*/
public static boolean isPubliclyRoutable(final InetAddress addrIP)
{
if (addrIP == null)
throw new NullPointerException("isPubliclyRoutable requires an IP address be passed to it!");
return !addrIP.isSiteLocalAddress() && !addrIP.isLinkLocalAddress() && !addrIP.isLoopbackAddress();
}
}
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