/* * Copyright (c) 2000, 2010, 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 com.sun.jndi.dns; import java.net.MalformedURLException;import java.util.ArrayList;import java.util.Hashtable;import java.util.List; import javax.naming.*;import javax.naming.spi.*; import com.sun.jndi.toolkit.url.UrlUtil;import sun.net.dns.ResolverConfiguration; // available since 1.4.1 /** * A DnsContextFactory serves as the initial context factory for DNS. * * <p> When an initial context is being created, the environment * property "java.naming.provider.url" should contain a DNS pseudo-URL * (see DnsUrl) or a space-separated list of them. Multiple URLs must * all have the same domain value. * If the property is not set, the default "dns:" is used. * * @author Scott Seligman */ public class DnsContextFactory implements InitialContextFactory { private static final String DEFAULT_URL = "dns:"; private static final int DEFAULT_PORT = 53; public Context getInitialContext(Hashtable<?,?> env) throws NamingException { if (env == null) { env = new Hashtable(5); } return urlToContext(getInitCtxUrl(env), env); } public static DnsContext getContext(String domain, String[] servers, Hashtable<?,?> env) throws NamingException { return new DnsContext(domain, servers, env); } /* * "urls" are used to determine the servers, but any domain * components are overridden by "domain". */ public static DnsContext getContext(String domain, DnsUrl[] urls, Hashtable env) throws NamingException { String[] servers = serversForUrls(urls); DnsContext ctx = getContext(domain, servers, env); if (platformServersUsed(urls)) { ctx.setProviderUrl(constructProviderUrl(domain, servers)); } return ctx; } /* * Public for use by product test suite. */ public static boolean platformServersAvailable() { return !filterNameServers( ResolverConfiguration.open().nameservers(), true ).isEmpty(); } private static Context urlToContext(String url, Hashtable env) throws NamingException { DnsUrl[] urls; try { urls = DnsUrl.fromList(url); } catch (MalformedURLException e) { throw new ConfigurationException(e.getMessage()); } if (urls.length == 0) { throw new ConfigurationException( "Invalid DNS pseudo-URL(s): " + url); } String domain = urls[0].getDomain(); // If multiple urls, all must have the same domain. for (int i = 1; i < urls.length; i++) { if (!domain.equalsIgnoreCase(urls[i].getDomain())) { throw new ConfigurationException( "Conflicting domains: " + url); } } return getContext(domain, urls, env); } /* * Returns all the servers specified in a set of URLs. * If a URL has no host (or port), the servers configured on the * underlying platform are used if possible. If no configured * servers can be found, then fall back to the old behavior of * using "localhost". * There must be at least one URL. */ private static String[] serversForUrls(DnsUrl[] urls) throws NamingException { if (urls.length == 0) { throw new ConfigurationException("DNS pseudo-URL required"); } List<String> servers = new ArrayList<>(); for (int i = 0; i < urls.length; i++) { String server = urls[i].getHost(); int port = urls[i].getPort(); if (server == null && port < 0) { // No server or port given, so look to underlying platform. // ResolverConfiguration does some limited caching, so the // following is reasonably efficient even if called rapid-fire. List<String> platformServers = filterNameServers( ResolverConfiguration.open().nameservers(), false); if (!platformServers.isEmpty()) { servers.addAll(platformServers); continue; // on to next URL (if any, which is unlikely) } } if (server == null) { server = "localhost"; } servers.add((port < 0) ? server : server + ":" + port); } return servers.toArray(new String[servers.size()]); } /* * Returns true if serversForUrls(urls) would make use of servers * from the underlying platform. */ private static boolean platformServersUsed(DnsUrl[] urls) { if (!platformServersAvailable()) { return false; } for (int i = 0; i < urls.length; i++) { if (urls[i].getHost() == null && urls[i].getPort() < 0) { return true; } } return false; } /* * Returns a value for the PROVIDER_URL property (space-separated URL * Strings) that reflects the given domain and servers. * Each server is of the form "server[:port]". * There must be at least one server. * IPv6 literal host names include delimiting brackets. */ private static String constructProviderUrl(String domain, String[] servers) { String path = ""; if (!domain.equals(".")) { try { path = "/" + UrlUtil.encode(domain, "ISO-8859-1"); } catch (java.io.UnsupportedEncodingException e) { // assert false : "ISO-Latin-1 charset unavailable"; } } StringBuffer buf = new StringBuffer(); for (int i = 0; i < servers.length; i++) { if (i > 0) { buf.append(' '); } buf.append("dns://").append(servers[i]).append(path); } return buf.toString(); } /* * Reads environment to find URL(s) of initial context. * Default URL is "dns:". */ private static String getInitCtxUrl(Hashtable env) { String url = (String) env.get(Context.PROVIDER_URL); return ((url != null) ? url : DEFAULT_URL); } /** * Removes any DNS server that's not permitted to access * @param input the input server[:port] list, must not be null * @param oneIsEnough return output once there exists one ok * @return the filtered list, all non-permitted input removed */ private static List filterNameServers(List input, boolean oneIsEnough) { SecurityManager security = System.getSecurityManager(); if (security == null || input == null || input.isEmpty()) { return input; } else { List output = new ArrayList(); for (Object o: input) { if (o instanceof String) { String platformServer = (String)o; int colon = platformServer.indexOf(':', platformServer.indexOf(']') + 1); int p = (colon < 0) ? DEFAULT_PORT : Integer.parseInt( platformServer.substring(colon + 1)); String s = (colon < 0) ? platformServer : platformServer.substring(0, colon); try { security.checkConnect(s, p); output.add(platformServer); if (oneIsEnough) { return output; } } catch (SecurityException se) { continue; } } } return output; } }}
/*
* Copyright (c) 2000, 2010, 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 com.sun.jndi.dns;
import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.Hashtable;
import java.util.List;
import javax.naming.*;
import javax.naming.spi.*;
import com.sun.jndi.toolkit.url.UrlUtil;
import sun.net.dns.ResolverConfiguration; // available since 1.4.1
/**
* A DnsContextFactory serves as the initial context factory for DNS.
*
* <p> When an initial context is being created, the environment
* property "java.naming.provider.url" should contain a DNS pseudo-URL
* (see DnsUrl) or a space-separated list of them. Multiple URLs must
* all have the same domain value.
* If the property is not set, the default "dns:" is used.
*
* @author Scott Seligman
*/
public class DnsContextFactory implements InitialContextFactory {
private static final String DEFAULT_URL = "dns:";
private static final int DEFAULT_PORT = 53;
public Context getInitialContext(Hashtable<?,?> env) throws NamingException {
if (env == null) {
env = new Hashtable(5);
}
return urlToContext(getInitCtxUrl(env), env);
}
public static DnsContext getContext(String domain,
String[] servers, Hashtable<?,?> env)
throws NamingException {
return new DnsContext(domain, servers, env);
}
/*
* "urls" are used to determine the servers, but any domain
* components are overridden by "domain".
*/
public static DnsContext getContext(String domain,
DnsUrl[] urls, Hashtable env)
throws NamingException {
String[] servers = serversForUrls(urls);
DnsContext ctx = getContext(domain, servers, env);
if (platformServersUsed(urls)) {
ctx.setProviderUrl(constructProviderUrl(domain, servers));
}
return ctx;
}
/*
* Public for use by product test suite.
*/
public static boolean platformServersAvailable() {
return !filterNameServers(
ResolverConfiguration.open().nameservers(), true
).isEmpty();
}
private static Context urlToContext(String url, Hashtable env)
throws NamingException {
DnsUrl[] urls;
try {
urls = DnsUrl.fromList(url);
} catch (MalformedURLException e) {
throw new ConfigurationException(e.getMessage());
}
if (urls.length == 0) {
throw new ConfigurationException(
"Invalid DNS pseudo-URL(s): " + url);
}
String domain = urls[0].getDomain();
// If multiple urls, all must have the same domain.
for (int i = 1; i < urls.length; i++) {
if (!domain.equalsIgnoreCase(urls[i].getDomain())) {
throw new ConfigurationException(
"Conflicting domains: " + url);
}
}
return getContext(domain, urls, env);
}
/*
* Returns all the servers specified in a set of URLs.
* If a URL has no host (or port), the servers configured on the
* underlying platform are used if possible. If no configured
* servers can be found, then fall back to the old behavior of
* using "localhost".
* There must be at least one URL.
*/
private static String[] serversForUrls(DnsUrl[] urls)
throws NamingException {
if (urls.length == 0) {
throw new ConfigurationException("DNS pseudo-URL required");
}
List<String> servers = new ArrayList<>();
for (int i = 0; i < urls.length; i++) {
String server = urls[i].getHost();
int port = urls[i].getPort();
if (server == null && port < 0) {
// No server or port given, so look to underlying platform.
// ResolverConfiguration does some limited caching, so the
// following is reasonably efficient even if called rapid-fire.
List<String> platformServers = filterNameServers(
ResolverConfiguration.open().nameservers(), false);
if (!platformServers.isEmpty()) {
servers.addAll(platformServers);
continue; // on to next URL (if any, which is unlikely)
}
}
if (server == null) {
server = "localhost";
}
servers.add((port < 0)
? server
: server + ":" + port);
}
return servers.toArray(new String[servers.size()]);
}
/*
* Returns true if serversForUrls(urls) would make use of servers
* from the underlying platform.
*/
private static boolean platformServersUsed(DnsUrl[] urls) {
if (!platformServersAvailable()) {
return false;
}
for (int i = 0; i < urls.length; i++) {
if (urls[i].getHost() == null &&
urls[i].getPort() < 0) {
return true;
}
}
return false;
}
/*
* Returns a value for the PROVIDER_URL property (space-separated URL
* Strings) that reflects the given domain and servers.
* Each server is of the form "server[:port]".
* There must be at least one server.
* IPv6 literal host names include delimiting brackets.
*/
private static String constructProviderUrl(String domain,
String[] servers) {
String path = "";
if (!domain.equals(".")) {
try {
path = "/" + UrlUtil.encode(domain, "ISO-8859-1");
} catch (java.io.UnsupportedEncodingException e) {
// assert false : "ISO-Latin-1 charset unavailable";
}
}
StringBuffer buf = new StringBuffer();
for (int i = 0; i < servers.length; i++) {
if (i > 0) {
buf.append(' ');
}
buf.append("dns://").append(servers[i]).append(path);
}
return buf.toString();
}
/*
* Reads environment to find URL(s) of initial context.
* Default URL is "dns:".
*/
private static String getInitCtxUrl(Hashtable env) {
String url = (String) env.get(Context.PROVIDER_URL);
return ((url != null) ? url : DEFAULT_URL);
}
/**
* Removes any DNS server that's not permitted to access
* @param input the input server[:port] list, must not be null
* @param oneIsEnough return output once there exists one ok
* @return the filtered list, all non-permitted input removed
*/
private static List filterNameServers(List input, boolean oneIsEnough) {
SecurityManager security = System.getSecurityManager();
if (security == null || input == null || input.isEmpty()) {
return input;
} else {
List output = new ArrayList();
for (Object o: input) {
if (o instanceof String) {
String platformServer = (String)o;
int colon = platformServer.indexOf(':',
platformServer.indexOf(']') + 1);
int p = (colon < 0)
? DEFAULT_PORT
: Integer.parseInt(
platformServer.substring(colon + 1));
String s = (colon < 0)
? platformServer
: platformServer.substring(0, colon);
try {
security.checkConnect(s, p);
output.add(platformServer);
if (oneIsEnough) {
return output;
}
} catch (SecurityException se) {
continue;
}
}
}
return output;
}
}
}