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A main program (executable JAR) that will listen to port 29998. At first, it can only answer that it is an Envoy (a limited agent). The only function it supports is installing a -runpath. It will then create a framework + agent and transfer the connection to the just installed agent who will then install the bundles. This JAR is a main command for JPM called bndremote. In JPM, it will start up with debug enabled. This JAR does some highly complicated class loading wizardy to ensure that it does not enforce any constraints on the -runpath.
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package aQute.bnd.util.dto;

/*
 * Copyright (c) OSGi Alliance (2012, 2017). All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Super type for Data Transfer Objects.
 * 
 * A Data Transfer Object (DTO) is easily serializable having only public fields
 * of primitive types and their wrapper classes, Strings, enums, Version, and
 * DTOs. List, Set, Map, and array aggregates may also be used. The aggregates
 * must only hold objects of the listed types or aggregates.
 * 

 * The object graph from a Data Transfer Object must be a tree to simplify
 * serialization and deserialization.
 *
 * @author $Id: 505218c264553320b144bddb2d08db836d025245 $
 * @NotThreadSafe
 */
public abstract class DTO {

	/**
	 * Return a string representation of this DTO suitable for use when
	 * debugging.
	 * 

	 * The format of the string representation is not specified and subject to
	 * change.
	 *
	 * @return A string representation of this DTO suitable for use when
	 *         debugging.
	 */
	@Override
	public String toString() {
		return appendValue(new StringBuilder(), new IdentityHashMap(), "#", this).toString();
	}

	/**
	 * Append the specified DTO's string representation to the specified
	 * StringBuilder.
	 *
	 * @param result StringBuilder to which the string representation is
	 *            appended.
	 * @param objectRefs References to "seen" objects.
	 * @param refpath The reference path of the specified DTO.
	 * @param dto The DTO whose string representation is to be appended.
	 * @return The specified StringBuilder.
	 */
	private static StringBuilder appendDTO(final StringBuilder result, final Map objectRefs,
		final String refpath, final DTO dto) {
		result.append("{");
		String delim = "";
		for (Field field : dto.getClass()
			.getFields()) {
			if (Modifier.isStatic(field.getModifiers())) {
				continue;
			}
			result.append(delim);
			final String name = field.getName();
			appendString(result, name);
			result.append(":");
			Object value = null;
			try {
				value = field.get(dto);
			} catch (IllegalAccessException e) {
				// use null value;
			}
			appendValue(result, objectRefs, refpath + "/" + name, value);
			delim = ", ";
		}
		result.append("}");
		return result;
	}

	/**
	 * Append the specified value's string representation to the specified
	 * StringBuilder.
	 * 
	 * This method handles cycles in the object graph, using path-based
	 * references, even though the specification requires the object graph from
	 * a DTO to be a tree.
	 *
	 * @param result StringBuilder to which the string representation is
	 *            appended.
	 * @param objectRefs References to "seen" objects.
	 * @param refpath The reference path of the specified value.
	 * @param value The object whose string representation is to be appended.
	 * @return The specified StringBuilder.
	 */
	private static StringBuilder appendValue(final StringBuilder result, final Map objectRefs,
		final String refpath, final Object value) {
		if (value == null) {
			return result.append("null");
		}
		// Simple Java types
		if (value instanceof String || value instanceof Character) {
			return appendString(result, compress(value.toString()));
		}
		if (value instanceof Number || value instanceof Boolean) {
			return result.append(value.toString());
		}
		if (value instanceof Enum enumValue) {
			return appendString(result, enumValue.name());
		}
		if ("org.osgi.framework.Version".equals(value.getClass()
			.getName())) {
			return appendString(result, value.toString());
		}
		if ("aQute.bnd.version.Version".equals(value.getClass()
			.getName())) {
			return appendString(result, value.toString());
		}

		// Complex types
		final String path = objectRefs.get(value);
		if (path != null) {
			result.append("{\"$ref\":");
			appendString(result, path);
			result.append("}");
			return result;
		}
		objectRefs.put(value, refpath);

		if (value instanceof DTO dtoValue) {
			return appendDTO(result, objectRefs, refpath, dtoValue);
		}
		if (value instanceof Map mapValue) {
			return appendMap(result, objectRefs, refpath, mapValue);
		}
		if (value instanceof List || value instanceof Set) {
			return appendIterable(result, objectRefs, refpath, (Iterable) value);
		}
		if (value.getClass()
			.isArray()) {
			return appendArray(result, objectRefs, refpath, value);
		}
		return appendString(result, compress(value.toString()));
	}

	/**
	 * Append the specified array's string representation to the specified
	 * StringBuilder.
	 *
	 * @param result StringBuilder to which the string representation is
	 *            appended.
	 * @param objectRefs References to "seen" objects.
	 * @param refpath The reference path of the specified array.
	 * @param array The array whose string representation is to be appended.
	 * @return The specified StringBuilder.
	 */
	private static StringBuilder appendArray(final StringBuilder result, final Map objectRefs,
		final String refpath, final Object array) {
		result.append("[");
		final int length = Array.getLength(array);
		for (int i = 0; i < length; i++) {
			if (i > 0) {
				result.append(",");
			}
			appendValue(result, objectRefs, refpath + "/" + i, Array.get(array, i));
		}
		result.append("]");
		return result;
	}

	/**
	 * Append the specified iterable's string representation to the specified
	 * StringBuilder.
	 *
	 * @param result StringBuilder to which the string representation is
	 *            appended.
	 * @param objectRefs References to "seen" objects.
	 * @param refpath The reference path of the specified list.
	 * @param iterable The iterable whose string representation is to be
	 *            appended.
	 * @return The specified StringBuilder.
	 */
	private static StringBuilder appendIterable(final StringBuilder result, final Map objectRefs,
		final String refpath, final Iterable iterable) {
		result.append("[");
		int i = 0;
		for (Object item : iterable) {
			if (i > 0) {
				result.append(",");
			}
			appendValue(result, objectRefs, refpath + "/" + i, item);
			i++;
		}
		result.append("]");
		return result;
	}

	/**
	 * Append the specified map's string representation to the specified
	 * StringBuilder.
	 *
	 * @param result StringBuilder to which the string representation is
	 *            appended.
	 * @param objectRefs References to "seen" objects.
	 * @param refpath The reference path of the specified map.
	 * @param map The map whose string representation is to be appended.
	 * @return The specified StringBuilder.
	 */
	private static StringBuilder appendMap(final StringBuilder result, final Map objectRefs,
		final String refpath, final Map map) {
		result.append("{");
		String delim = "";
		for (Map.Entry entry : map.entrySet()) {
			result.append(delim);
			final String name = String.valueOf(entry.getKey());
			appendString(result, name);
			result.append(":");
			final Object value = entry.getValue();
			appendValue(result, objectRefs, refpath + "/" + name, value);
			delim = ", ";
		}
		result.append("}");
		return result;
	}

	/**
	 * Append the specified string to the specified StringBuilder.
	 *
	 * @param result StringBuilder to which the string is appended.
	 * @param string The string to be appended.
	 * @return The specified StringBuilder.
	 */
	private static StringBuilder appendString(final StringBuilder result, final CharSequence string) {
		result.append("\"");
		int i = result.length();
		result.append(string);
		while (i < result.length()) { // escape if necessary
			char c = result.charAt(i);
			if ((c == '"') || (c == '\\')) {
				result.insert(i, '\\');
				i = i + 2;
				continue;
			}
			if (c < 0x20) {
				result.insert(i + 1, Integer.toHexString(c | 0x10000));
				result.replace(i, i + 2, "\\u");
				i = i + 6;
				continue;
			}
			i++;
		}
		result.append("\"");
		return result;
	}

	/**
	 * Compress, in length, the specified string.
	 *
	 * @param in The string to potentially compress.
	 * @return The string compressed, if necessary.
	 */
	private static CharSequence compress(final CharSequence in) {
		final int length = in.length();
		if (length <= 21) {
			return in;
		}
		StringBuilder result = new StringBuilder(21);
		result.append(in, 0, 9);
		result.append("...");
		result.append(in, length - 9, length);
		return result;
	}
}