trunk/java/com/l2jserver/util/IPSubnet.java

@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2004-2014 L2J Server
+ * 
+ * This file is part of L2J Server.
+ * 
+ * L2J Server is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * L2J Server is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.l2jserver.util;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+
+public class IPSubnet
+{
+	final byte[] _addr;
+	final byte[] _mask;
+	final boolean _isIPv4;
+	
+	public IPSubnet(String input) throws UnknownHostException, NumberFormatException, ArrayIndexOutOfBoundsException
+	{
+		int idx = input.indexOf("/");
+		if (idx > 0)
+		{
+			_addr = InetAddress.getByName(input.substring(0, idx)).getAddress();
+			_mask = getMask(Integer.parseInt(input.substring(idx + 1)), _addr.length);
+			_isIPv4 = _addr.length == 4;
+			
+			if (!applyMask(_addr))
+			{
+				throw new UnknownHostException(input);
+			}
+		}
+		else
+		{
+			_addr = InetAddress.getByName(input).getAddress();
+			_mask = getMask(_addr.length * 8, _addr.length); // host, no need to check mask
+			_isIPv4 = _addr.length == 4;
+		}
+	}
+	
+	public IPSubnet(InetAddress addr, int mask) throws UnknownHostException
+	{
+		_addr = addr.getAddress();
+		_isIPv4 = _addr.length == 4;
+		_mask = getMask(mask, _addr.length);
+		if (!applyMask(_addr))
+		{
+			throw new UnknownHostException(addr.toString() + "/" + mask);
+		}
+	}
+	
+	public byte[] getAddress()
+	{
+		return _addr;
+	}
+	
+	public boolean applyMask(byte[] addr)
+	{
+		// V4 vs V4 or V6 vs V6 checks
+		if (_isIPv4 == (addr.length == 4))
+		{
+			for (int i = 0; i < _addr.length; i++)
+			{
+				if ((addr[i] & _mask[i]) != _addr[i])
+				{
+					return false;
+				}
+			}
+		}
+		else
+		{
+			// check for embedded v4 in v6 addr (not done !)
+			if (_isIPv4)
+			{
+				// my V4 vs V6
+				for (int i = 0; i < _addr.length; i++)
+				{
+					if ((addr[i + 12] & _mask[i]) != _addr[i])
+					{
+						return false;
+					}
+				}
+			}
+			else
+			{
+				// my V6 vs V4
+				for (int i = 0; i < _addr.length; i++)
+				{
+					if ((addr[i] & _mask[i + 12]) != _addr[i + 12])
+					{
+						return false;
+					}
+				}
+			}
+		}
+		
+		return true;
+	}
+	
+	@Override
+	public String toString()
+	{
+		int size = 0;
+		for (byte element : _mask)
+		{
+			size += Integer.bitCount((element & 0xFF));
+		}
+		
+		try
+		{
+			return InetAddress.getByAddress(_addr).toString() + "/" + size;
+		}
+		catch (UnknownHostException e)
+		{
+			return "Invalid";
+		}
+	}
+	
+	@Override
+	public boolean equals(Object o)
+	{
+		if (this == o)
+		{
+			return true;
+		}
+		if (o instanceof IPSubnet)
+		{
+			return applyMask(((IPSubnet) o).getAddress());
+		}
+		else if (o instanceof InetAddress)
+		{
+			return applyMask(((InetAddress) o).getAddress());
+		}
+		
+		return false;
+	}
+	
+	private static final byte[] getMask(int n, int maxLength) throws UnknownHostException
+	{
+		if ((n > (maxLength << 3)) || (n < 0))
+		{
+			throw new UnknownHostException("Invalid netmask: " + n);
+		}
+		
+		final byte[] result = new byte[maxLength];
+		for (int i = 0; i < maxLength; i++)
+		{
+			result[i] = (byte) 0xFF;
+		}
+		
+		for (int i = (maxLength << 3) - 1; i >= n; i--)
+		{
+			result[i >> 3] = (byte) (result[i >> 3] << 1);
+		}
+		
+		return result;
+	}
+}