1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.jndi.ldap;
  27 
  28 import javax.naming.NamingException;
  29 import javax.naming.ldap.spi.LdapDnsProvider;
  30 import javax.naming.ldap.spi.LdapDnsProviderResult;
  31 import java.util.ArrayList;
  32 import java.util.List;
  33 import java.util.Map;
  34 import java.util.Optional;
  35 
  36 public class DefaultLdapDnsProvider {
  37 
  38     public Optional<LdapDnsProviderResult> lookupEndpoints(String url,
  39                                                            Map<?,?> env)
  40             throws NamingException
  41     {
  42         if (url == null || env == null) {
  43             throw new NullPointerException();
  44         }
  45 
  46         String domainName;
  47         List<String> endpoints = new ArrayList<>();
  48         LdapURL ldapUrl = new LdapURL(url);
  49         String dn = ldapUrl.getDN();
  50         String host = ldapUrl.getHost();
  51         int port = ldapUrl.getPort();
  52         String[] hostports;
  53 
  54         // handle a URL with no hostport (ldap:/// or ldaps:///)
  55         // locate the LDAP service using the URL's distinguished name
  56         if (host == null
  57                 && port == -1
  58                 && dn != null
  59                 && (domainName = ServiceLocator.mapDnToDomainName(dn)) != null
  60                 && (hostports = ServiceLocator.getLdapService(domainName, env)) != null) {
  61             // Generate new URLs that include the discovered hostports.
  62             // Reuse the original URL scheme.
  63             String scheme = ldapUrl.getScheme() + "://";
  64             String query = ldapUrl.getQuery();
  65             String urlSuffix = ldapUrl.getPath() + (query != null ? query : "");
  66             for (String hostPort : hostports) {
  67                 // the hostports come from the DNS SRV records
  68                 // we assume the SRV record is scheme aware
  69                 endpoints.add(scheme + hostPort + urlSuffix);
  70             }
  71         } else {
  72             // we don't have enough information to set the domain name
  73             // correctly
  74             domainName = "";
  75             endpoints.add(url);
  76         }
  77 
  78         LdapDnsProviderResult res = new LdapDnsProviderResult(domainName, endpoints);
  79         if (res.getEndpoints().size() == 0 && res.getDomainName().isEmpty()) {
  80             return Optional.empty();
  81         } else {
  82             return Optional.of(res);
  83         }
  84     }
  85 
  86 }