Code/net/minecraft/server/rcon/thread/RconClient.java

package net.minecraft.server.rcon.thread;

import com.mojang.logging.LogUtils;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.Locale;
import net.minecraft.server.ServerInterface;
import net.minecraft.server.rcon.PktUtils;
import org.slf4j.Logger;

public class RconClient extends GenericThread {
    private static final Logger LOGGER = LogUtils.getLogger();
    private static final int SERVERDATA_AUTH = 3;
    private static final int SERVERDATA_EXECCOMMAND = 2;
    private static final int SERVERDATA_RESPONSE_VALUE = 0;
    private static final int SERVERDATA_AUTH_RESPONSE = 2;
    private static final int SERVERDATA_AUTH_FAILURE = -1;
    private boolean authed;
    private final Socket client;
    private final byte[] buf = new byte[1460];
    private final String rconPassword;
    private final ServerInterface serverInterface;

    RconClient(ServerInterface p_11587_, String p_11588_, Socket p_11589_) {
        super("RCON Client " + p_11589_.getInetAddress());
        this.serverInterface = p_11587_;
        this.client = p_11589_;

        try {
            this.client.setSoTimeout(0);
        } catch (Exception exception) {
            this.running = false;
        }

        this.rconPassword = p_11588_;
    }

    @Override
    public void run() {
        try {
            try {
                while (this.running) {
                    BufferedInputStream bufferedinputstream = new BufferedInputStream(this.client.getInputStream());
                    int i = bufferedinputstream.read(this.buf, 0, 1460);
                    if (10 > i) {
                        return;
                    }

                    int j = 0;
                    int k = PktUtils.intFromByteArray(this.buf, 0, i);
                    if (k != i - 4) {
                        return;
                    }

                    j += 4;
                    int l = PktUtils.intFromByteArray(this.buf, j, i);
                    j += 4;
                    int i1 = PktUtils.intFromByteArray(this.buf, j);
                    j += 4;
                    switch (i1) {
                        case 2:
                            if (this.authed) {
                                String s1 = PktUtils.stringFromByteArray(this.buf, j, i);

                                try {
                                    this.sendCmdResponse(l, this.serverInterface.runCommand(s1));
                                } catch (Exception exception) {
                                    this.sendCmdResponse(l, "Error executing: " + s1 + " (" + exception.getMessage() + ")");
                                }
                                break;
                            }

                            this.sendAuthFailure();
                            break;
                        case 3:
                            String s = PktUtils.stringFromByteArray(this.buf, j, i);
                            j += s.length();
                            if (!s.isEmpty() && s.equals(this.rconPassword)) {
                                this.authed = true;
                                this.send(l, 2, "");
                                break;
                            }

                            this.authed = false;
                            this.sendAuthFailure();
                            break;
                        default:
                            this.sendCmdResponse(l, String.format(Locale.ROOT, "Unknown request %s", Integer.toHexString(i1)));
                    }
                }

                return;
            } catch (IOException ioexception) {
            } catch (Exception exception1) {
                LOGGER.error("Exception whilst parsing RCON input", (Throwable)exception1);
            }
        } finally {
            this.closeSocket();
            LOGGER.info("Thread {} shutting down", this.name);
            this.running = false;
        }
    }

    private void send(int p_11591_, int p_11592_, String p_11593_) throws IOException {
        ByteArrayOutputStream bytearrayoutputstream = new ByteArrayOutputStream(1248);
        DataOutputStream dataoutputstream = new DataOutputStream(bytearrayoutputstream);
        byte[] abyte = p_11593_.getBytes(StandardCharsets.UTF_8);
        dataoutputstream.writeInt(Integer.reverseBytes(abyte.length + 10));
        dataoutputstream.writeInt(Integer.reverseBytes(p_11591_));
        dataoutputstream.writeInt(Integer.reverseBytes(p_11592_));
        dataoutputstream.write(abyte);
        dataoutputstream.write(0);
        dataoutputstream.write(0);
        this.client.getOutputStream().write(bytearrayoutputstream.toByteArray());
    }

    private void sendAuthFailure() throws IOException {
        this.send(-1, 2, "");
    }

    private void sendCmdResponse(int p_11595_, String p_11596_) throws IOException {
        int i = p_11596_.length();

        do {
            int j = 4096 <= i ? 4096 : i;
            this.send(p_11595_, 0, p_11596_.substring(0, j));
            p_11596_ = p_11596_.substring(j);
            i = p_11596_.length();
        } while (0 != i);
    }

    @Override
    public void stop() {
        this.running = false;
        this.closeSocket();
        super.stop();
    }

    private void closeSocket() {
        try {
            this.client.close();
        } catch (IOException ioexception) {
            LOGGER.warn("Failed to close socket", (Throwable)ioexception);
        }
    }
}