org.sonar.process.NetworkUtils.java Source code

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Here is the source code for org.sonar.process.NetworkUtils.java

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/*
 * SonarQube
 * Copyright (C) 2009-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.process;

import java.io.IOException;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.ServerSocket;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.HashSet;
import java.util.Set;
import java.util.stream.Collectors;

import static java.lang.String.format;
import static java.util.Collections.list;
import static org.apache.commons.lang.StringUtils.isBlank;

public final class NetworkUtils {

    private static final Set<Integer> ALREADY_ALLOCATED = new HashSet<>();
    private static final int MAX_TRIES = 50;

    private NetworkUtils() {
        // prevent instantiation
    }

    public static int getNextAvailablePort(InetAddress address) {
        return getNextAvailablePort(address, PortAllocator.INSTANCE);
    }

    /**
     * Identifying the localhost machine
     * It will try to retrieve the hostname and the IPv4 addresses
     *
     * @return "hostname (ipv4_1, ipv4_2...)"
     */
    public static String getHostName() {
        String hostname;
        String ips;
        try {
            hostname = InetAddress.getLocalHost().getHostName();
        } catch (UnknownHostException e) {
            hostname = "unresolved hostname";
        }

        try {
            ips = list(NetworkInterface.getNetworkInterfaces()).stream()
                    .flatMap(netif -> list(netif.getInetAddresses()).stream().filter(inetAddress ->
                    // Removing IPv6 for the time being
                    inetAddress instanceof Inet4Address &&
                    // Removing loopback addresses, useless for identifying a server
                            !inetAddress.isLoopbackAddress() &&
                            // Removing interfaces without IPs
                            !isBlank(inetAddress.getHostAddress())).map(InetAddress::getHostAddress))
                    .filter(p -> !isBlank(p)).collect(Collectors.joining(","));
        } catch (SocketException e) {
            ips = "unresolved IPs";
        }

        return format("%s (%s)", hostname, ips);
    }

    /**
     * Warning - the allocated ports are kept in memory and are never clean-up. Besides the memory consumption,
     * that means that ports already allocated are never freed. As a consequence
     * no more than ~64512 calls to this method are allowed.
     */
    static int getNextAvailablePort(InetAddress address, PortAllocator portAllocator) {
        for (int i = 0; i < MAX_TRIES; i++) {
            int port = portAllocator.getAvailable(address);
            if (isValidPort(port)) {
                ALREADY_ALLOCATED.add(port);
                return port;
            }
        }
        throw new IllegalStateException("Fail to find an available port on " + address);
    }

    private static boolean isValidPort(int port) {
        return port > 1023 && !ALREADY_ALLOCATED.contains(port);
    }

    static class PortAllocator {
        private static final PortAllocator INSTANCE = new PortAllocator();

        int getAvailable(InetAddress address) {
            try (ServerSocket socket = new ServerSocket(0, 50, address)) {
                return socket.getLocalPort();
            } catch (IOException e) {
                throw new IllegalStateException("Fail to find an available port on " + address, e);
            }
        }
    }
}