org.silverpeas.components.silvercrawler.util.IpAddressMatcher.java Source code

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Here is the source code for org.silverpeas.components.silvercrawler.util.IpAddressMatcher.java

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/*
 * Copyright (C) 2000 - 2018 Silverpeas
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * As a special exception to the terms and conditions of version 3.0 of
 * the GPL, you may redistribute this Program in connection with Free/Libre
 * Open Source Software ("FLOSS") applications as described in Silverpeas's
 * FLOSS exception. You should have received a copy of the text describing
 * the FLOSS exception, and it is also available here:
 * "https://www.silverpeas.org/legal/floss_exception.html"
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.silverpeas.components.silvercrawler.util;

import org.apache.commons.lang3.StringUtils;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Arrays;

/**
 * Matches a request based on IP Address or subnet mask matching against the remote address.
 * <p>
 * Both IPv6 and IPv4 addresses are supported, but a matcher which is configured with an IPv4
 * address will never match a request which returns an IPv6 address, and vice-versa.
 * <p>
 * Implementation based on the org.springframework.security.web.util.matcher.IpAddressMatcher of
 * Spring Security.
 * @author Luke Taylor
 */
public class IpAddressMatcher {
    private final int nMaskBits;
    private final InetAddress requiredAddress;

    /**
     * Takes a specific IP address or a range specified using the
     * IP/Netmask (e.g. 192.168.1.0/24 or 202.24.0.0/14).
     * @param ipAddress the address or range of addresses from which the request must come.
     */
    public IpAddressMatcher(String ipAddress) {

        if (ipAddress.indexOf('/') > 0) {
            String[] addressAndMask = StringUtils.split(ipAddress, "/");
            ipAddress = addressAndMask[0];
            nMaskBits = Integer.parseInt(addressAndMask[1]);
        } else {
            nMaskBits = -1;
        }
        requiredAddress = parseAddress(ipAddress);
    }

    public boolean matches(String address) {
        InetAddress remoteAddress = parseAddress(address);

        if (!requiredAddress.getClass().equals(remoteAddress.getClass())) {
            return false;
        }

        if (nMaskBits < 0) {
            return remoteAddress.equals(requiredAddress);
        }

        byte[] remAddr = remoteAddress.getAddress();
        byte[] reqAddr = requiredAddress.getAddress();

        int oddBits = nMaskBits % 8;
        int nMaskBytes = nMaskBits / 8 + (oddBits == 0 ? 0 : 1);
        byte[] mask = new byte[nMaskBytes];

        Arrays.fill(mask, 0, oddBits == 0 ? mask.length : mask.length - 1, (byte) 0xFF);

        if (oddBits != 0) {
            int finalByte = (1 << oddBits) - 1;
            finalByte <<= 8 - oddBits;
            mask[mask.length - 1] = (byte) finalByte;
        }

        for (int i = 0; i < mask.length; i++) {
            if ((remAddr[i] & mask[i]) != (reqAddr[i] & mask[i])) {
                return false;
            }
        }

        return true;
    }

    private InetAddress parseAddress(String address) {
        try {
            return InetAddress.getByName(address);
        } catch (UnknownHostException e) {
            throw new IllegalArgumentException("Failed to parse address" + address, e);
        }
    }
}