oshi.software.os.windows.WindowsNetworkParams Maven / Gradle / Ivy

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/*
 * Copyright 2017-2023 The OSHI Project Contributors
 * SPDX-License-Identifier: MIT
 */
package oshi.software.os.windows;

import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

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

import com.sun.jna.Memory;
import com.sun.jna.Native;
import com.sun.jna.platform.win32.IPHlpAPI;
import com.sun.jna.platform.win32.IPHlpAPI.FIXED_INFO;
import com.sun.jna.platform.win32.IPHlpAPI.IP_ADDR_STRING;
import com.sun.jna.platform.win32.Kernel32;
import com.sun.jna.platform.win32.Kernel32Util;
import com.sun.jna.platform.win32.Win32Exception;
import com.sun.jna.platform.win32.WinError;

import oshi.annotation.concurrent.ThreadSafe;
import oshi.jna.ByRef.CloseableIntByReference;
import oshi.software.common.AbstractNetworkParams;
import oshi.util.ExecutingCommand;
import oshi.util.ParseUtil;

/**
 * WindowsNetworkParams class.
 */
@ThreadSafe
final class WindowsNetworkParams extends AbstractNetworkParams {

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

    private static final int COMPUTER_NAME_DNS_DOMAIN_FULLY_QUALIFIED = 3;

    @Override
    public String getDomainName() {
        char[] buffer = new char[256];
        try (CloseableIntByReference bufferSize = new CloseableIntByReference(buffer.length)) {
            if (!Kernel32.INSTANCE.GetComputerNameEx(COMPUTER_NAME_DNS_DOMAIN_FULLY_QUALIFIED, buffer, bufferSize)) {
                LOG.error("Failed to get dns domain name. Error code: {}", Kernel32.INSTANCE.GetLastError());
                return "";
            }
        }
        return Native.toString(buffer);
    }

    @Override
    public String[] getDnsServers() {
        try (CloseableIntByReference bufferSize = new CloseableIntByReference()) {
            int ret = IPHlpAPI.INSTANCE.GetNetworkParams(null, bufferSize);
            if (ret != WinError.ERROR_BUFFER_OVERFLOW) {
                LOG.error("Failed to get network parameters buffer size. Error code: {}", ret);
                return new String[0];
            }

            try (Memory buffer = new Memory(bufferSize.getValue())) {
                ret = IPHlpAPI.INSTANCE.GetNetworkParams(buffer, bufferSize);
                if (ret != 0) {
                    LOG.error("Failed to get network parameters. Error code: {}", ret);
                    return new String[0];
                }
                FIXED_INFO fixedInfo = new FIXED_INFO(buffer);

                List list = new ArrayList<>();
                IP_ADDR_STRING dns = fixedInfo.DnsServerList;
                while (dns != null) {
                    // a char array of size 16.
                    // This array holds an IPv4 address in dotted decimal notation.
                    String addr = Native.toString(dns.IpAddress.String, StandardCharsets.US_ASCII);
                    int nullPos = addr.indexOf(0);
                    if (nullPos != -1) {
                        addr = addr.substring(0, nullPos);
                    }
                    list.add(addr);
                    dns = dns.Next;
                }
                return list.toArray(new String[0]);
            }
        }
    }

    @Override
    public String getHostName() {
        try {
            return Kernel32Util.getComputerName();
        } catch (Win32Exception e) {
            return super.getHostName();
        }
    }

    @Override
    public String getIpv4DefaultGateway() {
        return parseIpv4Route();
    }

    @Override
    public String getIpv6DefaultGateway() {
        return parseIpv6Route();
    }

    private static String parseIpv4Route() {
        List lines = ExecutingCommand.runNative("route print -4 0.0.0.0");
        for (String line : lines) {
            String[] fields = ParseUtil.whitespaces.split(line.trim());
            if (fields.length > 2 && "0.0.0.0".equals(fields[0])) {
                return fields[2];
            }
        }
        return "";
    }

    private static String parseIpv6Route() {
        List lines = ExecutingCommand.runNative("route print -6 ::/0");
        for (String line : lines) {
            String[] fields = ParseUtil.whitespaces.split(line.trim());
            if (fields.length > 3 && "::/0".equals(fields[2])) {
                return fields[3];
            }
        }
        return "";
    }
}