LinuxNetworkParams.java

/**
 * Oshi (https://github.com/oshi/oshi)
 *
 * Copyright (c) 2010 - 2017 The Oshi Project Team
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Maintainers:
 * dblock[at]dblock[dot]org
 * widdis[at]gmail[dot]com
 * enrico.bianchi[at]gmail[dot]com
 *
 * Contributors:
 * https://github.com/oshi/oshi/graphs/contributors
 */
package oshi.software.os.linux;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.sun.jna.ptr.PointerByReference;

import oshi.jna.platform.linux.Libc;
import oshi.software.common.AbstractNetworkParams;
import oshi.util.ExecutingCommand;
import oshi.util.ParseUtil;

public class LinuxNetworkParams extends AbstractNetworkParams {

    private static final long serialVersionUID = 1L;

    private static final Logger LOG = LoggerFactory.getLogger(LinuxNetworkParams.class);

    private static final String IPV4_DEFAULT_DEST = "0.0.0.0";
    private static final String IPV6_DEFAULT_DEST = "::/0";

    /**
     * {@inheritDoc}
     */
    @Override
    public String getDomainName() {
        Libc.Addrinfo hint = new Libc.Addrinfo();
        hint.ai_flags = Libc.AI_CANONNAME;
        String hostname = "";
        try {
            hostname = InetAddress.getLocalHost().getHostName();
        } catch (UnknownHostException e) {
            LOG.error("Unknown host exception when getting address of local host: {}", e);
            return "";
        }
        PointerByReference ptr = new PointerByReference();
        int res = Libc.INSTANCE.getaddrinfo(hostname, null, hint, ptr);
        if (res > 0) {
            LOG.error("Failed getaddrinfo(): {}", Libc.INSTANCE.gai_strerror(res));
            return "";
        }
        Libc.Addrinfo info = new Libc.Addrinfo(ptr.getValue());
        String canonname = info.ai_canonname.trim();
        Libc.INSTANCE.freeaddrinfo(ptr.getValue());
        return canonname;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getIpv4DefaultGateway() {
        List<String> routes = ExecutingCommand.runNative("route -A inet -n");
        if (routes.size() <= 2) {
            return "";
        }

        String gateway = "";
        int minMetric = Integer.MAX_VALUE;

        for (int i = 2; i < routes.size(); i++) {
            String[] fields = routes.get(i).split("\\s+");
            if (fields.length > 4 && fields[0].equals(IPV4_DEFAULT_DEST)) {
                boolean isGateway = fields[3].indexOf('G') != -1;
                int metric = ParseUtil.parseIntOrDefault(fields[4], Integer.MAX_VALUE);
                if (isGateway && metric < minMetric) {
                    minMetric = metric;
                    gateway = fields[1];
                }
            }
        }
        return gateway;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getIpv6DefaultGateway() {
        List<String> routes = ExecutingCommand.runNative("route -A inet6 -n");
        if (routes.size() <= 2) {
            return "";
        }

        String gateway = "";
        int minMetric = Integer.MAX_VALUE;

        for (int i = 2; i < routes.size(); i++) {
            String[] fields = routes.get(i).split("\\s+");
            if (fields.length > 3 && fields[0].equals(IPV6_DEFAULT_DEST)) {
                boolean isGateway = fields[2].indexOf('G') != -1;
                int metric = ParseUtil.parseIntOrDefault(fields[3], Integer.MAX_VALUE);
                if (isGateway && metric < minMetric) {
                    minMetric = metric;
                    gateway = fields[1];
                }
            }
        }
        return gateway;
    }
}