/*
 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation. Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.net;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;
import java.io.Serializable;
import java.net.InetAddress;
import java.security.AccessController;
import java.security.Permission;
import java.security.PermissionCollection;
import java.security.PrivilegedAction;
import java.security.Security;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.Vector;
import java.util.StringJoiner;
import java.util.StringTokenizer;
import java.util.concurrent.ConcurrentSkipListMap;
import sun.net.util.IPAddressUtil;
import sun.net.PortConfig;
import sun.security.util.RegisteredDomain;
import sun.security.util.SecurityConstants;
import sun.security.util.Debug;


/**
 * This class represents access to a network via sockets.
 * A SocketPermission consists of a
 * host specification and a set of "actions" specifying ways to
 * connect to that host. The host is specified as
 * <pre>
 * host = (hostname | IPv4address | iPv6reference) [:portrange]
 * portrange = portnumber | -portnumber | portnumber-[portnumber]
 * </pre>
 * The host is expressed as a DNS name, as a numerical IP address,
 * or as "localhost" (for the local machine).
 * The wildcard "*" may be included once in a DNS name host
 * specification. If it is included, it must be in the leftmost
 * position, as in "*.example.com".
 * <p>
 * The format of the IPv6reference should follow that specified in <a
 * href="http://www.ietf.org/rfc/rfc2732.txt"><i>RFC&nbsp;2732: Format
 * for Literal IPv6 Addresses in URLs</i></a>:
 * <pre>
 * ipv6reference = "[" IPv6address "]"
 *</pre>
 * For example, you can construct a SocketPermission instance
 * as the following:
 * <pre>
 * String hostAddress = inetaddress.getHostAddress();
 * if (inetaddress instanceof Inet6Address) {
 * sp = new SocketPermission("[" + hostAddress + "]:" + port, action);
 * } else {
 * sp = new SocketPermission(hostAddress + ":" + port, action);
 * }
 * </pre>
 * or
 * <pre>
 * String host = url.getHost();
 * sp = new SocketPermission(host + ":" + port, action);
 * </pre>
 * <p>
 * The <A HREF="Inet6Address.html#lform">full uncompressed form</A> of
 * an IPv6 literal address is also valid.
 * <p>
 * The port or portrange is optional. A port specification of the
 * form "N-", where <i>N</i> is a port number, signifies all ports
 * numbered <i>N</i> and above, while a specification of the
 * form "-N" indicates all ports numbered <i>N</i> and below.
 * The special port value {@code 0} refers to the entire <i>ephemeral</i>
 * port range. This is a fixed range of ports a system may use to
 * allocate dynamic ports from. The actual range may be system dependent.
 * <p>
 * The possible ways to connect to the host are
 * <pre>
 * accept
 * connect
 * listen
 * resolve
 * </pre>
 * The "listen" action is only meaningful when used with "localhost" and
 * means the ability to bind to a specified port.
 * The "resolve" action is implied when any of the other actions are present.
 * The action "resolve" refers to host/ip name service lookups.
 * <P>
 * The actions string is converted to lowercase before processing.
 * <p>As an example of the creation and meaning of SocketPermissions,
 * note that if the following permission:
 *
 * <pre>
 * p1 = new SocketPermission("foo.example.com:7777", "connect,accept");
 * </pre>
 *
 * is granted to some code, it allows that code to connect to port 7777 on
 * {@code foo.example.com}, and to accept connections on that port.
 *
 * <p>Similarly, if the following permission:
 *
 * <pre>
 * p2 = new SocketPermission("localhost:1024-", "accept,connect,listen");
 * </pre>
 *
 * is granted to some code, it allows that code to
 * accept connections on, connect to, or listen on any port between
 * 1024 and 65535 on the local host.
 *
 * <p>Note: Granting code permission to accept or make connections to remote
 * hosts may be dangerous because malevolent code can then more easily
 * transfer and share confidential data among parties who may not
 * otherwise have access to the data.
 *
 * @see java.security.Permissions
 * @see SocketPermission
 *
 *
 * @author Marianne Mueller
 * @author Roland Schemers
 * @since 1.2
 *
 * @serial exclude
 */

public final class SocketPermission extends Permission
 implements java.io.Serializable
{
 private static final long serialVersionUID = -7204263841984476862L;

 /**
 * Connect to host:port
 */
 private static final int CONNECT = 0x1;

 /**
 * Listen on host:port
 */
 private static final int LISTEN = 0x2;

 /**
 * Accept a connection from host:port
 */
 private static final int ACCEPT = 0x4;

 /**
 * Resolve DNS queries
 */
 private static final int RESOLVE = 0x8;

 /**
 * No actions
 */
 private static final int NONE = 0x0;

 /**
 * All actions
 */
 private static final int ALL = CONNECT|LISTEN|ACCEPT|RESOLVE;

 // various port constants
 private static final int PORT_MIN = 0;
 private static final int PORT_MAX = 65535;
 private static final int PRIV_PORT_MAX = 1023;
 private static final int DEF_EPH_LOW = 49152;

 // the actions mask
 private transient int mask;

 /**
 * the actions string.
 *
 * @serial
 */

 private String actions; // Left null as long as possible, then
 // created and re-used in the getAction function.

 // hostname part as it is passed
 private transient String hostname;

 // the canonical name of the host
 // in the case of "*.foo.com", cname is ".foo.com".

 private transient String cname;

 // all the IP addresses of the host
 private transient InetAddress[] addresses;

 // true if the hostname is a wildcard (e.g. "*.example.com")
 private transient boolean wildcard;

 // true if we were initialized with a single numeric IP address
 private transient boolean init_with_ip;

 // true if this SocketPermission represents an invalid/unknown host
 // used for implies when the delayed lookup has already failed
 private transient boolean invalid;

 // port range on host
 private transient int[] portrange;

 private transient boolean defaultDeny = false;

 // true if this SocketPermission represents a hostname
 // that failed our reverse mapping heuristic test
 private transient boolean untrusted;
 private transient boolean trusted;

 // true if the sun.net.trustNameService system property is set
 private static boolean trustNameService;

 private static Debug debug = null;
 private static boolean debugInit = false;

 // lazy initializer
 private static class EphemeralRange {
 static final int low = initEphemeralPorts("low", DEF_EPH_LOW);
 static final int high = initEphemeralPorts("high", PORT_MAX);
 };

 static {
 Boolean tmp = java.security.AccessController.doPrivileged(
 new sun.security.action.GetBooleanAction("sun.net.trustNameService"));
 trustNameService = tmp.booleanValue();
 }

 private static synchronized Debug getDebug() {
 if (!debugInit) {
 debug = Debug.getInstance("access");
 debugInit = true;
 }
 return debug;
 }

 /**
 * Creates a new SocketPermission object with the specified actions.
 * The host is expressed as a DNS name, or as a numerical IP address.
 * Optionally, a port or a portrange may be supplied (separated
 * from the DNS name or IP address by a colon).
 * <p>
 * To specify the local machine, use "localhost" as the <i>host</i>.
 * Also note: An empty <i>host</i> String ("") is equivalent to "localhost".
 * <p>
 * The <i>actions</i> parameter contains a comma-separated list of the
 * actions granted for the specified host (and port(s)). Possible actions are
 * "connect", "listen", "accept", "resolve", or
 * any combination of those. "resolve" is automatically added
 * when any of the other three are specified.
 * <p>
 * Examples of SocketPermission instantiation are the following:
 * <pre>
 * nr = new SocketPermission("www.example.com", "connect");
 * nr = new SocketPermission("www.example.com:80", "connect");
 * nr = new SocketPermission("*.example.com", "connect");
 * nr = new SocketPermission("*.edu", "resolve");
 * nr = new SocketPermission("204.160.241.0", "connect");
 * nr = new SocketPermission("localhost:1024-65535", "listen");
 * nr = new SocketPermission("204.160.241.0:1024-65535", "connect");
 * </pre>
 *
 * @param host the hostname or IP address of the computer, optionally
 * including a colon followed by a port or port range.
 * @param action the action string.
 */
 public SocketPermission(String host, String action) {
 super(getHost(host));
 // name initialized to getHost(host); NPE detected in getHost()
 init(getName(), getMask(action));
 }


 SocketPermission(String host, int mask) {
 super(getHost(host));
 // name initialized to getHost(host); NPE detected in getHost()
 init(getName(), mask);
 }

 private void setDeny() {
 defaultDeny = true;
 }

 private static String getHost(String host) {
 if (host.isEmpty()) {
 return "localhost";
 } else {
 /* IPv6 literal address used in this context should follow
 * the format specified in RFC 2732;
 * if not, we try to solve the unambiguous case
 */
 int ind;
 if (host.charAt(0) != '[') {
 if ((ind = host.indexOf(':')) != host.lastIndexOf(':')) {
 /* More than one ":", meaning IPv6 address is not
 * in RFC 2732 format;
 * We will rectify user errors for all unambiguous cases
 */
 StringTokenizer st = new StringTokenizer(host, ":");
 int tokens = st.countTokens();
 if (tokens == 9) {
 // IPv6 address followed by port
 ind = host.lastIndexOf(':');
 host = "[" + host.substring(0, ind) + "]" +
 host.substring(ind);
 } else if (tokens == 8 && host.indexOf("::") == -1) {
 // IPv6 address only, not followed by port
 host = "[" + host + "]";
 } else {
 // could be ambiguous
 throw new IllegalArgumentException("Ambiguous"+
 " hostport part");
 }
 }
 }
 return host;
 }
 }

 private int[] parsePort(String port)
 throws Exception
 {

 if (port == null || port.isEmpty() || port.equals("*")) {
 return new int[] {PORT_MIN, PORT_MAX};
 }

 int dash = port.indexOf('-');

 if (dash == -1) {
 int p = Integer.parseInt(port);
 return new int[] {p, p};
 } else {
 String low = port.substring(0, dash);
 String high = port.substring(dash+1);
 int l,h;

 if (low.isEmpty()) {
 l = PORT_MIN;
 } else {
 l = Integer.parseInt(low);
 }

 if (high.isEmpty()) {
 h = PORT_MAX;
 } else {
 h = Integer.parseInt(high);
 }
 if (l < 0 || h < 0 || h<l)
 throw new IllegalArgumentException("invalid port range");

 return new int[] {l, h};
 }
 }

 /**
 * Returns true if the permission has specified zero
 * as its value (or lower bound) signifying the ephemeral range
 */
 private boolean includesEphemerals() {
 return portrange[0] == 0;
 }

 /**
 * Initialize the SocketPermission object. We don't do any DNS lookups
 * as this point, instead we hold off until the implies method is
 * called.
 */
 private void init(String host, int mask) {
 // Set the integer mask that represents the actions

 if ((mask & ALL) != mask)
 throw new IllegalArgumentException("invalid actions mask");

 // always OR in RESOLVE if we allow any of the others
 this.mask = mask | RESOLVE;

 // Parse the host name. A name has up to three components, the
 // hostname, a port number, or two numbers representing a port
 // range. "www.example.com:8080-9090" is a valid host name.

 // With IPv6 an address can be 2010:836B:4179::836B:4179
 // An IPv6 address needs to be enclose in []
 // For ex: [2010:836B:4179::836B:4179]:8080-9090
 // Refer to RFC 2732 for more information.

 int rb = 0 ;
 int start = 0, end = 0;
 int sep = -1;
 String hostport = host;
 if (host.charAt(0) == '[') {
 start = 1;
 rb = host.indexOf(']');
 if (rb != -1) {
 host = host.substring(start, rb);
 } else {
 throw new
 IllegalArgumentException("invalid host/port: "+host);
 }
 sep = hostport.indexOf(':', rb+1);
 } else {
 start = 0;
 sep = host.indexOf(':', rb);
 end = sep;
 if (sep != -1) {
 host = host.substring(start, end);
 }
 }

 if (sep != -1) {
 String port = hostport.substring(sep+1);
 try {
 portrange = parsePort(port);
 } catch (Exception e) {
 throw new
 IllegalArgumentException("invalid port range: "+port);
 }
 } else {
 portrange = new int[] { PORT_MIN, PORT_MAX };
 }

 hostname = host;

 // is this a domain wildcard specification
 if (host.lastIndexOf('*') > 0) {
 throw new
 IllegalArgumentException("invalid host wildcard specification");
 } else if (host.startsWith("*")) {
 wildcard = true;
 if (host.equals("*")) {
 cname = "";
 } else if (host.startsWith("*.")) {
 cname = host.substring(1).toLowerCase();
 } else {
 throw new
 IllegalArgumentException("invalid host wildcard specification");
 }
 return;
 } else {
 if (!host.isEmpty()) {
 // see if we are being initialized with an IP address.
 char ch = host.charAt(0);
 if (ch == ':' || Character.digit(ch, 16) != -1) {
 byte ip[] = IPAddressUtil.textToNumericFormatV4(host);
 if (ip == null) {
 ip = IPAddressUtil.textToNumericFormatV6(host);
 }
 if (ip != null) {
 try {
 addresses =
 new InetAddress[]
 {InetAddress.getByAddress(ip) };
 init_with_ip = true;
 } catch (UnknownHostException uhe) {
 // this shouldn't happen
 invalid = true;
 }
 }
 }
 }
 }
 }

 /**
 * Convert an action string to an integer actions mask.
 *
 * @param action the action string
 * @return the action mask
 */
 private static int getMask(String action) {

 if (action == null) {
 throw new NullPointerException("action can't be null");
 }

 if (action.isEmpty()) {
 throw new IllegalArgumentException("action can't be empty");
 }

 int mask = NONE;

 // Use object identity comparison against known-interned strings for
 // performance benefit (these values are used heavily within the JDK).
 if (action == SecurityConstants.SOCKET_RESOLVE_ACTION) {
 return RESOLVE;
 } else if (action == SecurityConstants.SOCKET_CONNECT_ACTION) {
 return CONNECT;
 } else if (action == SecurityConstants.SOCKET_LISTEN_ACTION) {
 return LISTEN;
 } else if (action == SecurityConstants.SOCKET_ACCEPT_ACTION) {
 return ACCEPT;
 } else if (action == SecurityConstants.SOCKET_CONNECT_ACCEPT_ACTION) {
 return CONNECT|ACCEPT;
 }

 char[] a = action.toCharArray();

 int i = a.length - 1;
 if (i < 0)
 return mask;

 while (i != -1) {
 char c;

 // skip whitespace
 while ((i!=-1) && ((c = a[i]) == ' ' ||
 c == '\r' ||
 c == '\n' ||
 c == '\f' ||
 c == '\t'))
 i--;

 // check for the known strings
 int matchlen;

 if (i >= 6 && (a[i-6] == 'c' || a[i-6] == 'C') &&
 (a[i-5] == 'o' || a[i-5] == 'O') &&
 (a[i-4] == 'n' || a[i-4] == 'N') &&
 (a[i-3] == 'n' || a[i-3] == 'N') &&
 (a[i-2] == 'e' || a[i-2] == 'E') &&
 (a[i-1] == 'c' || a[i-1] == 'C') &&
 (a[i] == 't' || a[i] == 'T'))
 {
 matchlen = 7;
 mask |= CONNECT;

 } else if (i >= 6 && (a[i-6] == 'r' || a[i-6] == 'R') &&
 (a[i-5] == 'e' || a[i-5] == 'E') &&
 (a[i-4] == 's' || a[i-4] == 'S') &&
 (a[i-3] == 'o' || a[i-3] == 'O') &&
 (a[i-2] == 'l' || a[i-2] == 'L') &&
 (a[i-1] == 'v' || a[i-1] == 'V') &&
 (a[i] == 'e' || a[i] == 'E'))
 {
 matchlen = 7;
 mask |= RESOLVE;

 } else if (i >= 5 && (a[i-5] == 'l' || a[i-5] == 'L') &&
 (a[i-4] == 'i' || a[i-4] == 'I') &&
 (a[i-3] == 's' || a[i-3] == 'S') &&
 (a[i-2] == 't' || a[i-2] == 'T') &&
 (a[i-1] == 'e' || a[i-1] == 'E') &&
 (a[i] == 'n' || a[i] == 'N'))
 {
 matchlen = 6;
 mask |= LISTEN;

 } else if (i >= 5 && (a[i-5] == 'a' || a[i-5] == 'A') &&
 (a[i-4] == 'c' || a[i-4] == 'C') &&
 (a[i-3] == 'c' || a[i-3] == 'C') &&
 (a[i-2] == 'e' || a[i-2] == 'E') &&
 (a[i-1] == 'p' || a[i-1] == 'P') &&
 (a[i] == 't' || a[i] == 'T'))
 {
 matchlen = 6;
 mask |= ACCEPT;

 } else {
 // parse error
 throw new IllegalArgumentException(
 "invalid permission: " + action);
 }

 // make sure we didn't just match the tail of a word
 // like "ackbarfaccept". Also, skip to the comma.
 boolean seencomma = false;
 while (i >= matchlen && !seencomma) {
 switch(a[i-matchlen]) {
 case ',':
 seencomma = true;
 break;
 case ' ': case '\r': case '\n':
 case '\f': case '\t':
 break;
 default:
 throw new IllegalArgumentException(
 "invalid permission: " + action);
 }
 i--;
 }

 // point i at the location of the comma minus one (or -1).
 i -= matchlen;
 }

 return mask;
 }

 private boolean isUntrusted()
 throws UnknownHostException
 {
 if (trusted) return false;
 if (invalid || untrusted) return true;
 try {
 if (!trustNameService && (defaultDeny ||
 sun.net.www.URLConnection.isProxiedHost(hostname))) {
 if (this.cname == null) {
 this.getCanonName();
 }
 if (!match(cname, hostname)) {
 // Last chance
 if (!authorized(hostname, addresses[0].getAddress())) {
 untrusted = true;
 Debug debug = getDebug();
 if (debug != null && Debug.isOn("failure")) {
 debug.println("socket access restriction: proxied host " + "(" + addresses[0] + ")" + " does not match " + cname + " from reverse lookup");
 }
 return true;
 }
 }
 trusted = true;
 }
 } catch (UnknownHostException uhe) {
 invalid = true;
 throw uhe;
 }
 return false;
 }

 /**
 * attempt to get the fully qualified domain name
 *
 */
 void getCanonName()
 throws UnknownHostException
 {
 if (cname != null || invalid || untrusted) return;

 // attempt to get the canonical name

 try {
 // first get the IP addresses if we don't have them yet
 // this is because we need the IP address to then get
 // FQDN.
 if (addresses == null) {
 getIP();
 }

 // we have to do this check, otherwise we might not
 // get the fully qualified domain name
 if (init_with_ip) {
 cname = addresses[0].getHostName(false).toLowerCase();
 } else {
 cname = InetAddress.getByName(addresses[0].getHostAddress()).
 getHostName(false).toLowerCase();
 }
 } catch (UnknownHostException uhe) {
 invalid = true;
 throw uhe;
 }
 }

 private transient String cdomain, hdomain;

 /**
 * previously we allowed domain names to be specified in IDN ACE form
 * Need to check for that and convert to Unicode
 */
 private static String checkForIDN(String name) {
 if (name.startsWith("xn--") || name.contains(".xn--")) {
 return IDN.toUnicode(name);
 } else {
 return name;
 }
 }

 private boolean match(String cname, String hname) {
 String a = checkForIDN(cname.toLowerCase());
 String b = checkForIDN(hname.toLowerCase());
 if (a.startsWith(b) &&
 ((a.length() == b.length()) || (a.charAt(b.length()) == '.'))) {
 return true;
 }
 if (cdomain == null) {
 cdomain = RegisteredDomain.from(a)
 .map(RegisteredDomain::name)
 .orElse(a);
 }
 if (hdomain == null) {
 hdomain = RegisteredDomain.from(b)
 .map(RegisteredDomain::name)
 .orElse(b);
 }

 return !cdomain.isEmpty() && !hdomain.isEmpty() && cdomain.equals(hdomain);
 }

 private boolean authorized(String cname, byte[] addr) {
 if (addr.length == 4)
 return authorizedIPv4(cname, addr);
 else if (addr.length == 16)
 return authorizedIPv6(cname, addr);
 else
 return false;
 }

 private boolean authorizedIPv4(String cname, byte[] addr) {
 String authHost = "";
 InetAddress auth;

 try {
 authHost = "auth." +
 (addr[3] & 0xff) + "." + (addr[2] & 0xff) + "." +
 (addr[1] & 0xff) + "." + (addr[0] & 0xff) +
 ".in-addr.arpa";
 // Following check seems unnecessary
 // auth = InetAddress.getAllByName0(authHost, false)[0];
 authHost = hostname + '.' + authHost;
 auth = InetAddress.getAllByName0(authHost, false)[0];
 if (auth.equals(InetAddress.getByAddress(addr))) {
 return true;
 }
 Debug debug = getDebug();
 if (debug != null && Debug.isOn("failure")) {
 debug.println("socket access restriction: IP address of " + auth + " != " + InetAddress.getByAddress(addr));
 }
 } catch (UnknownHostException uhe) {
 Debug debug = getDebug();
 if (debug != null && Debug.isOn("failure")) {
 debug.println("socket access restriction: forward lookup failed for " + authHost);
 }
 }
 return false;
 }

 private boolean authorizedIPv6(String cname, byte[] addr) {
 String authHost = "";
 InetAddress auth;

 try {
 StringBuilder sb = new StringBuilder(39);

 for (int i = 15; i >= 0; i--) {
 sb.append(Integer.toHexString(((addr[i]) & 0x0f)));
 sb.append('.');
 sb.append(Integer.toHexString(((addr[i] >> 4) & 0x0f)));
 sb.append('.');
 }
 authHost = "auth." + sb.toString() + "IP6.ARPA";
 //auth = InetAddress.getAllByName0(authHost, false)[0];
 authHost = hostname + '.' + authHost;
 auth = InetAddress.getAllByName0(authHost, false)[0];
 if (auth.equals(InetAddress.getByAddress(addr)))
 return true;
 Debug debug = getDebug();
 if (debug != null && Debug.isOn("failure")) {
 debug.println("socket access restriction: IP address of " + auth + " != " + InetAddress.getByAddress(addr));
 }
 } catch (UnknownHostException uhe) {
 Debug debug = getDebug();
 if (debug != null && Debug.isOn("failure")) {
 debug.println("socket access restriction: forward lookup failed for " + authHost);
 }
 }
 return false;
 }


 /**
 * get IP addresses. Sets invalid to true if we can't get them.
 *
 */
 void getIP()
 throws UnknownHostException
 {
 if (addresses != null || wildcard || invalid) return;

 try {
 // now get all the IP addresses
 String host;
 if (getName().charAt(0) == '[') {
 // Literal IPv6 address
 host = getName().substring(1, getName().indexOf(']'));
 } else {
 int i = getName().indexOf(':');
 if (i == -1)
 host = getName();
 else {
 host = getName().substring(0,i);
 }
 }

 addresses =
 new InetAddress[] {InetAddress.getAllByName0(host, false)[0]};

 } catch (UnknownHostException uhe) {
 invalid = true;
 throw uhe;
 } catch (IndexOutOfBoundsException iobe) {
 invalid = true;
 throw new UnknownHostException(getName());
 }
 }

 /**
 * Checks if this socket permission object "implies" the
 * specified permission.
 * <P>
 * More specifically, this method first ensures that all of the following
 * are true (and returns false if any of them are not):
 * <ul>
 * <li> <i>p</i> is an instanceof SocketPermission,
 * <li> <i>p</i>'s actions are a proper subset of this
 * object's actions, and
 * <li> <i>p</i>'s port range is included in this port range. Note:
 * port range is ignored when p only contains the action, 'resolve'.
 * </ul>
 *
 * Then {@code implies} checks each of the following, in order,
 * and for each returns true if the stated condition is true:
 * <ul>
 * <li> If this object was initialized with a single IP address and one of <i>p</i>'s
 * IP addresses is equal to this object's IP address.
 * <li>If this object is a wildcard domain (such as *.example.com), and
 * <i>p</i>'s canonical name (the name without any preceding *)
 * ends with this object's canonical host name. For example, *.example.com
 * implies *.foo.example.com.
 * <li>If this object was not initialized with a single IP address, and one of this
 * object's IP addresses equals one of <i>p</i>'s IP addresses.
 * <li>If this canonical name equals <i>p</i>'s canonical name.
 * </ul>
 *
 * If none of the above are true, {@code implies} returns false.
 * @param p the permission to check against.
 *
 * @return true if the specified permission is implied by this object,
 * false if not.
 */
 @Override
 public boolean implies(Permission p) {
 int i,j;

 if (!(p instanceof SocketPermission))
 return false;

 if (p == this)
 return true;

 SocketPermission that = (SocketPermission) p;

 return ((this.mask & that.mask) == that.mask) &&
 impliesIgnoreMask(that);
 }

 /**
 * Checks if the incoming Permission's action are a proper subset of
 * the this object's actions.
 * <P>
 * Check, in the following order:
 * <ul>
 * <li> Checks that "p" is an instanceof a SocketPermission
 * <li> Checks that "p"'s actions are a proper subset of the
 * current object's actions.
 * <li> Checks that "p"'s port range is included in this port range
 * <li> If this object was initialized with an IP address, checks that
 * one of "p"'s IP addresses is equal to this object's IP address.
 * <li> If either object is a wildcard domain (i.e., "*.example.com"),
 * attempt to match based on the wildcard.
 * <li> If this object was not initialized with an IP address, attempt
 * to find a match based on the IP addresses in both objects.
 * <li> Attempt to match on the canonical hostnames of both objects.
 * </ul>
 * @param that the incoming permission request
 *
 * @return true if "permission" is a proper subset of the current object,
 * false if not.
 */
 boolean impliesIgnoreMask(SocketPermission that) {
 int i,j;

 if ((that.mask & RESOLVE) != that.mask) {

 // check simple port range
 if ((that.portrange[0] < this.portrange[0]) ||
 (that.portrange[1] > this.portrange[1])) {

 // if either includes the ephemeral range, do full check
 if (this.includesEphemerals() || that.includesEphemerals()) {
 if (!inRange(this.portrange[0], this.portrange[1],
 that.portrange[0], that.portrange[1]))
 {
 return false;
 }
 } else {
 return false;
 }
 }
 }

 // allow a "*" wildcard to always match anything
 if (this.wildcard && "".equals(this.cname))
 return true;

 // return if either one of these NetPerm objects are invalid...
 if (this.invalid || that.invalid) {
 return compareHostnames(that);
 }

 try {
 if (this.init_with_ip) { // we only check IP addresses
 if (that.wildcard)
 return false;

 if (that.init_with_ip) {
 return (this.addresses[0].equals(that.addresses[0]));
 } else {
 if (that.addresses == null) {
 that.getIP();
 }
 for (i=0; i < that.addresses.length; i++) {
 if (this.addresses[0].equals(that.addresses[i]))
 return true;
 }
 }
 // since "this" was initialized with an IP address, we
 // don't check any other cases
 return false;
 }

 // check and see if we have any wildcards...
 if (this.wildcard || that.wildcard) {
 // if they are both wildcards, return true iff
 // that's cname ends with this cname (i.e., *.example.com
 // implies *.foo.example.com)
 if (this.wildcard && that.wildcard)
 return (that.cname.endsWith(this.cname));

 // a non-wildcard can't imply a wildcard
 if (that.wildcard)
 return false;

 // this is a wildcard, lets see if that's cname ends with
 // it...
 if (that.cname == null) {
 that.getCanonName();
 }
 return (that.cname.endsWith(this.cname));
 }

 // compare IP addresses
 if (this.addresses == null) {
 this.getIP();
 }

 if (that.addresses == null) {
 that.getIP();
 }

 if (!(that.init_with_ip && this.isUntrusted())) {
 for (j = 0; j < this.addresses.length; j++) {
 for (i=0; i < that.addresses.length; i++) {
 if (this.addresses[j].equals(that.addresses[i]))
 return true;
 }
 }

 // XXX: if all else fails, compare hostnames?
 // Do we really want this?
 if (this.cname == null) {
 this.getCanonName();
 }

 if (that.cname == null) {
 that.getCanonName();
 }

 return (this.cname.equalsIgnoreCase(that.cname));
 }

 } catch (UnknownHostException uhe) {
 return compareHostnames(that);
 }

 // make sure the first thing that is done here is to return
 // false. If not, uncomment the return false in the above catch.

 return false;
 }

 private boolean compareHostnames(SocketPermission that) {
 // we see if the original names/IPs passed in were equal.

 String thisHost = hostname;
 String thatHost = that.hostname;

 if (thisHost == null) {
 return false;
 } else if (this.wildcard) {
 final int cnameLength = this.cname.length();
 return thatHost.regionMatches(true,
 (thatHost.length() - cnameLength),
 this.cname, 0, cnameLength);
 } else {
 return thisHost.equalsIgnoreCase(thatHost);
 }
 }

 /**
 * Checks two SocketPermission objects for equality.
 *
 * @param obj the object to test for equality with this object.
 *
 * @return true if <i>obj</i> is a SocketPermission, and has the
 * same hostname, port range, and actions as this
 * SocketPermission object. However, port range will be ignored
 * in the comparison if <i>obj</i> only contains the action, 'resolve'.
 */
 @Override
 public boolean equals(Object obj) {
 if (obj == this)
 return true;

 if (! (obj instanceof SocketPermission))
 return false;

 SocketPermission that = (SocketPermission) obj;

 //this is (overly?) complex!!!

 // check the mask first
 if (this.mask != that.mask) return false;

 if ((that.mask & RESOLVE) != that.mask) {
 // now check the port range...
 if ((this.portrange[0] != that.portrange[0]) ||
 (this.portrange[1] != that.portrange[1])) {
 return false;
 }
 }

 // short cut. This catches:
 // "crypto" equal to "crypto", or
 // "1.2.3.4" equal to "1.2.3.4.", or
 // "*.edu" equal to "*.edu", but it
 // does not catch "crypto" equal to
 // "crypto.foo.example.com".

 if (this.getName().equalsIgnoreCase(that.getName())) {
 return true;
 }

 // we now attempt to get the Canonical (FQDN) name and
 // compare that. If this fails, about all we can do is return
 // false.

 try {
 this.getCanonName();
 that.getCanonName();
 } catch (UnknownHostException uhe) {
 return false;
 }

 if (this.invalid || that.invalid)
 return false;

 if (this.cname != null) {
 return this.cname.equalsIgnoreCase(that.cname);
 }

 return false;
 }

 /**
 * Returns the hash code value for this object.
 *
 * @return a hash code value for this object.
 */
 @Override
 public int hashCode() {
 /*
 * If this SocketPermission was initialized with an IP address
 * or a wildcard, use getName().hashCode(), otherwise use
 * the hashCode() of the host name returned from
 * java.net.InetAddress.getHostName method.
 */

 if (init_with_ip || wildcard) {
 return this.getName().hashCode();
 }

 try {
 getCanonName();
 } catch (UnknownHostException uhe) {

 }

 if (invalid || cname == null)
 return this.getName().hashCode();
 else
 return this.cname.hashCode();
 }

 /**
 * Return the current action mask.
 *
 * @return the actions mask.
 */

 int getMask() {
 return mask;
 }

 /**
 * Returns the "canonical string representation" of the actions in the
 * specified mask.
 * Always returns present actions in the following order:
 * connect, listen, accept, resolve.
 *
 * @param mask a specific integer action mask to translate into a string
 * @return the canonical string representation of the actions
 */
 private static String getActions(int mask) {
 StringJoiner sj = new StringJoiner(",");
 if ((mask & CONNECT) == CONNECT) {
 sj.add("connect");
 }
 if ((mask & LISTEN) == LISTEN) {
 sj.add("listen");
 }
 if ((mask & ACCEPT) == ACCEPT) {
 sj.add("accept");
 }
 if ((mask & RESOLVE) == RESOLVE) {
 sj.add("resolve");
 }
 return sj.toString();
 }

 /**
 * Returns the canonical string representation of the actions.
 * Always returns present actions in the following order:
 * connect, listen, accept, resolve.
 *
 * @return the canonical string representation of the actions.
 */
 @Override
 public String getActions()
 {
 if (actions == null)
 actions = getActions(this.mask);

 return actions;
 }

 /**
 * Returns a new PermissionCollection object for storing SocketPermission
 * objects.
 * <p>
 * SocketPermission objects must be stored in a manner that allows them
 * to be inserted into the collection in any order, but that also enables the
 * PermissionCollection {@code implies}
 * method to be implemented in an efficient (and consistent) manner.
 *
 * @return a new PermissionCollection object suitable for storing SocketPermissions.
 */
 @Override
 public PermissionCollection newPermissionCollection() {
 return new SocketPermissionCollection();
 }

 /**
 * WriteObject is called to save the state of the SocketPermission
 * to a stream. The actions are serialized, and the superclass
 * takes care of the name.
 */
 private synchronized void writeObject(java.io.ObjectOutputStream s)
 throws IOException
 {
 // Write out the actions. The superclass takes care of the name
 // call getActions to make sure actions field is initialized
 if (actions == null)
 getActions();
 s.defaultWriteObject();
 }

 /**
 * readObject is called to restore the state of the SocketPermission from
 * a stream.
 */
 private synchronized void readObject(java.io.ObjectInputStream s)
 throws IOException, ClassNotFoundException
 {
 // Read in the action, then initialize the rest
 s.defaultReadObject();
 init(getName(),getMask(actions));
 }

 /**
 * Check the system/security property for the ephemeral port range
 * for this system. The suffix is either "high" or "low"
 */
 private static int initEphemeralPorts(String suffix, int defval) {
 return AccessController.doPrivileged(
 new PrivilegedAction<>(){
 public Integer run() {
 int val = Integer.getInteger(
 "jdk.net.ephemeralPortRange."+suffix, -1
 );
 if (val != -1) {
 return val;
 } else {
 return suffix.equals("low") ?
 PortConfig.getLower() : PortConfig.getUpper();
 }
 }
 }
 );
 }

 /**
 * Check if the target range is within the policy range
 * together with the ephemeral range for this platform
 * (if policy includes ephemeral range)
 */
 private static boolean inRange(
 int policyLow, int policyHigh, int targetLow, int targetHigh
 )
 {
 final int ephemeralLow = EphemeralRange.low;
 final int ephemeralHigh = EphemeralRange.high;

 if (targetLow == 0) {
 // check policy includes ephemeral range
 if (!inRange(policyLow, policyHigh, ephemeralLow, ephemeralHigh)) {
 return false;
 }
 if (targetHigh == 0) {
 // nothing left to do
 return true;
 }
 // continue check with first real port number
 targetLow = 1;
 }

 if (policyLow == 0 && policyHigh == 0) {
 // ephemeral range only
 return targetLow >= ephemeralLow && targetHigh <= ephemeralHigh;
 }

 if (policyLow != 0) {
 // simple check of policy only
 return targetLow >= policyLow && targetHigh <= policyHigh;
 }

 // policyLow == 0 which means possibly two ranges to check

 // first check if policy and ephem range overlap/contiguous

 if (policyHigh >= ephemeralLow - 1) {
 return targetHigh <= ephemeralHigh;
 }

 // policy and ephem range do not overlap

 // target range must lie entirely inside policy range or eph range

 return (targetLow <= policyHigh && targetHigh <= policyHigh) ||
 (targetLow >= ephemeralLow && targetHigh <= ephemeralHigh);
 }
 /*
 public String toString()
 {
 StringBuffer s = new StringBuffer(super.toString() + "\n" +
 "cname = " + cname + "\n" +
 "wildcard = " + wildcard + "\n" +
 "invalid = " + invalid + "\n" +
 "portrange = " + portrange[0] + "," + portrange[1] + "\n");
 if (addresses != null) for (int i=0; i<addresses.length; i++) {
 s.append( addresses[i].getHostAddress());
 s.append("\n");
 } else {
 s.append("(no addresses)\n");
 }

 return s.toString();
 }

 public static void main(String args[]) throws Exception {
 SocketPermission this_ = new SocketPermission(args[0], "connect");
 SocketPermission that_ = new SocketPermission(args[1], "connect");
 System.out.println("-----\n");
 System.out.println("this.implies(that) = " + this_.implies(that_));
 System.out.println("-----\n");
 System.out.println("this = "+this_);
 System.out.println("-----\n");
 System.out.println("that = "+that_);
 System.out.println("-----\n");

 SocketPermissionCollection nps = new SocketPermissionCollection();
 nps.add(this_);
 nps.add(new SocketPermission("www-leland.stanford.edu","connect"));
 nps.add(new SocketPermission("www-example.com","connect"));
 System.out.println("nps.implies(that) = " + nps.implies(that_));
 System.out.println("-----\n");
 }
 */
}

/**

if (init'd with IP, key is IP as string)
if wildcard, its the wild card
else its the cname?

 *
 * @see java.security.Permission
 * @see java.security.Permissions
 * @see java.security.PermissionCollection
 *
 *
 * @author Roland Schemers
 *
 * @serial include
 */

final class SocketPermissionCollection extends PermissionCollection
 implements Serializable
{
 // Not serialized; see serialization section at end of class
 // A ConcurrentSkipListMap is used to preserve order, so that most
 // recently added permissions are checked first (see JDK-4301064).
 private transient ConcurrentSkipListMap<String, SocketPermission> perms;

 /**
 * Create an empty SocketPermissions object.
 *
 */
 public SocketPermissionCollection() {
 perms = new ConcurrentSkipListMap<>(new SPCComparator());
 }

 /**
 * Adds a permission to the SocketPermissions. The key for the hash is
 * the name in the case of wildcards, or all the IP addresses.
 *
 * @param permission the Permission object to add.
 *
 * @exception IllegalArgumentException - if the permission is not a
 * SocketPermission
 *
 * @exception SecurityException - if this SocketPermissionCollection object
 * has been marked readonly
 */
 @Override
 public void add(Permission permission) {
 if (! (permission instanceof SocketPermission))
 throw new IllegalArgumentException("invalid permission: "+
 permission);
 if (isReadOnly())
 throw new SecurityException(
 "attempt to add a Permission to a readonly PermissionCollection");

 SocketPermission sp = (SocketPermission)permission;

 // Add permission to map if it is absent, or replace with new
 // permission if applicable. NOTE: cannot use lambda for
 // remappingFunction parameter until JDK-8076596 is fixed.
 perms.merge(sp.getName(), sp,
 new java.util.function.BiFunction<>() {
 @Override
 public SocketPermission apply(SocketPermission existingVal,
 SocketPermission newVal) {
 int oldMask = existingVal.getMask();
 int newMask = newVal.getMask();
 if (oldMask != newMask) {
 int effective = oldMask | newMask;
 if (effective == newMask) {
 return newVal;
 }
 if (effective != oldMask) {
 return new SocketPermission(sp.getName(),
 effective);
 }
 }
 return existingVal;
 }
 }
 );
 }

 /**
 * Check and see if this collection of permissions implies the permissions
 * expressed in "permission".
 *
 * @param permission the Permission object to compare
 *
 * @return true if "permission" is a proper subset of a permission in
 * the collection, false if not.
 */
 @Override
 public boolean implies(Permission permission)
 {
 if (! (permission instanceof SocketPermission))
 return false;

 SocketPermission np = (SocketPermission) permission;

 int desired = np.getMask();
 int effective = 0;
 int needed = desired;

 //System.out.println("implies "+np);
 for (SocketPermission x : perms.values()) {
 //System.out.println(" trying "+x);
 if (((needed & x.getMask()) != 0) && x.impliesIgnoreMask(np)) {
 effective |= x.getMask();
 if ((effective & desired) == desired) {
 return true;
 }
 needed = (desired ^ effective);
 }
 }
 return false;
 }

 /**
 * Returns an enumeration of all the SocketPermission objects in the
 * container.
 *
 * @return an enumeration of all the SocketPermission objects.
 */
 @Override
 @SuppressWarnings("unchecked")
 public Enumeration<Permission> elements() {
 return (Enumeration)Collections.enumeration(perms.values());
 }

 private static final long serialVersionUID = 2787186408602843674L;

 // Need to maintain serialization interoperability with earlier releases,
 // which had the serializable field:

 //
 // The SocketPermissions for this set.
 // @serial
 //
 // private Vector permissions;

 /**
 * @serialField permissions java.util.Vector
 * A list of the SocketPermissions for this set.
 */
 private static final ObjectStreamField[] serialPersistentFields = {
 new ObjectStreamField("permissions", Vector.class),
 };

 /**
 * @serialData "permissions" field (a Vector containing the SocketPermissions).
 */
 /*
 * Writes the contents of the perms field out as a Vector for
 * serialization compatibility with earlier releases.
 */
 private void writeObject(ObjectOutputStream out) throws IOException {
 // Don't call out.defaultWriteObject()

 // Write out Vector
 Vector<SocketPermission> permissions = new Vector<>(perms.values());

 ObjectOutputStream.PutField pfields = out.putFields();
 pfields.put("permissions", permissions);
 out.writeFields();
 }

 /*
 * Reads in a Vector of SocketPermissions and saves them in the perms field.
 */
 private void readObject(ObjectInputStream in)
 throws IOException, ClassNotFoundException
 {
 // Don't call in.defaultReadObject()

 // Read in serialized fields
 ObjectInputStream.GetField gfields = in.readFields();

 // Get the one we want
 @SuppressWarnings("unchecked")
 Vector<SocketPermission> permissions = (Vector<SocketPermission>)gfields.get("permissions", null);
 perms = new ConcurrentSkipListMap<>(new SPCComparator());
 for (SocketPermission sp : permissions) {
 perms.put(sp.getName(), sp);
 }
 }

 /**
 * A simple comparator that orders new non-equal entries at the beginning.
 */
 private static class SPCComparator implements Comparator<String> {
 @Override
 public int compare(String s1, String s2) {
 if (s1.equals(s2)) {
 return 0;
 }
 return -1;
 }
 }
}