--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.dns.client/share/classes/jdk/dns/client/NetworkNamesResolver.java Thu Oct 31 16:16:21 2019 +0000
@@ -0,0 +1,382 @@
+/*
+ * Copyright (c) 2019, 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 jdk.dns.client;
+
+import jdk.dns.client.ex.DnsResolverException;
+import jdk.dns.client.internal.DnsName;
+import jdk.dns.client.internal.HostsFileResolver;
+import jdk.dns.client.internal.Resolver;
+import jdk.dns.client.internal.ResourceClassType;
+import jdk.dns.client.internal.ResourceRecord;
+import jdk.dns.client.internal.ResourceRecords;
+import jdk.dns.conf.DnsResolverConfiguration;
+import sun.net.util.IPAddressUtil;
+
+import java.net.InetAddress;
+import java.net.ProtocolFamily;
+import java.net.UnknownHostException;
+import java.security.PrivilegedAction;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class NetworkNamesResolver {
+
+ private final AddressFamily addressFamily;
+
+ public static NetworkNamesResolver open() throws UnknownHostException {
+ return new NetworkNamesResolver(AddressFamily.ANY);
+ }
+
+ public static NetworkNamesResolver open(ProtocolFamily protocolFamily) throws UnknownHostException {
+ return new NetworkNamesResolver(AddressFamily.fromProtocolFamily(protocolFamily));
+ }
+
+ private NetworkNamesResolver(AddressFamily addressFamily) throws UnknownHostException {
+ this.addressFamily = addressFamily;
+ this.dnsResolver = new Resolver(dnsResolverConfiguration.nameservers(), 1000, 4);
+ }
+
+
+ /**
+ * Lookup the IP address of a host.
+ * The family of required address needed can be specified with {@code addressFamily} parameter.
+ *
+ * @param hostname the specified host name
+ * @return first IP address that matches requested {@code addressFamily}
+ * @throws UnknownHostException if no IP address found for the specified host name and the specified address family
+ */
+ public InetAddress lookupHostAddr(String hostname) throws UnknownHostException {
+
+ // First try hosts file
+ // TODO: Add nsswitch.conf to select proper order
+ try {
+ return hostsFileResolver.getHostAddress(hostname, addressFamily);
+ } catch (UnknownHostException uhe) {
+ if (DEBUG) {
+ System.err.printf("Hosts file doesn't know '%s' host with '%s' address family%n",
+ hostname, addressFamily.toString());
+ }
+ }
+
+ // If no luck - try to ask name servers
+ try {
+ var results = lookup(hostname, addressFamily, true, true, 0);
+ if (results.isEmpty()) {
+ throw new UnknownHostException(hostname);
+ }
+ return results.get(0);
+ } catch (DnsResolverException e) {
+ UnknownHostException uhe = new UnknownHostException(hostname);
+ uhe.initCause(e);
+ throw uhe;
+ }
+ }
+
+ /**
+ * <p>Lookup a host mapping by name. Retrieve the IP addresses
+ * associated with a host.
+ *
+ * @param hostname the specified hostname
+ * @return array of IP addresses for the requested host
+ * @throws UnknownHostException if no IP address for the {@code hostname} could be found
+ */
+ public List<InetAddress> lookupAllHostAddr(String hostname) throws UnknownHostException {
+ // First try hosts file
+ // TODO: Add nsswitch.conf ReloadTracker and parser to select proper order
+ try {
+ return List.of(hostsFileResolver.getHostAddress(hostname));
+ } catch (UnknownHostException uhe) {
+ if (DEBUG) {
+ System.err.printf("Resolver API: Hosts file doesn't know '%s' host%n", hostname);
+ }
+ }
+ try {
+ var results = lookup(hostname, AddressFamily.ANY, false, true, 0);
+ if (results.isEmpty()) {
+ throw new UnknownHostException(hostname + " unknown host name");
+ }
+ return results;
+ } catch (DnsResolverException e) {
+ UnknownHostException uhe = new UnknownHostException(hostname);
+ uhe.initCause(e);
+ throw uhe;
+ }
+ }
+
+ /**
+ * Lookup the host name corresponding to the IP address provided.
+ *
+ * @param address the specified IP address
+ * @return {@code String} representing the host name
+ * @throws UnknownHostException if no host found for the specified IP address
+ */
+ public String getHostByAddr(InetAddress address) throws UnknownHostException {
+ var results = getAllHostsByAddr(address);
+ return results.get(0);
+ }
+
+ /**
+ * Lookup all known host names which correspond to the IP address provided
+ *
+ * @param address the specified IP address
+ * @return array of {@code String} representing the host names
+ * @throws UnknownHostException if no host found for the specified IP address
+ */
+ public List<String> getAllHostsByAddr(InetAddress address) throws UnknownHostException {
+ // First try hosts file
+ // TODO: Add nsswitch.conf to select proper order
+ try {
+ return List.of(hostsFileResolver.getByAddress(address));
+ } catch (UnknownHostException uhe) {
+ if (DEBUG) {
+ System.err.printf("Resolver API: No host in hosts file with %s address%n", address);
+ }
+ }
+ try {
+ var literalIP = addressToLiteralIP(address);
+ var family = AddressFamily.fromInetAddress(address);
+ var results = rlookup(literalIP, family);
+ if (results.isEmpty()) {
+ throw new UnknownHostException();
+ }
+ // remove trailing dot
+ return results.stream()
+ .map(host -> host.endsWith(".") ? host.substring(0, host.length() - 1) : host)
+ .collect(Collectors.toList());
+ } catch (DnsResolverException dre) {
+ UnknownHostException uhe = new UnknownHostException();
+ uhe.initCause(dre);
+ throw uhe;
+ }
+ }
+
+ private Set<String> prepareDomainsSearchList() {
+ var domainsToSearch = new LinkedHashSet<String>();
+ var domain = dnsResolverConfiguration.domain();
+ // First will try the domain
+ if (!domain.isBlank()) {
+ domainsToSearch.add(domain);
+ }
+ // Then will iterate over search list
+ domainsToSearch.addAll(dnsResolverConfiguration.searchlist());
+ if (DEBUG) {
+ System.out.printf("Domains search list:%s%n", domainsToSearch);
+ }
+ return domainsToSearch;
+ }
+
+ private List<InetAddress> lookup(String host, AddressFamily addressFamily, boolean oneIsEnough, boolean checkDomains, int depth) throws UnknownHostException, DnsResolverException {
+
+ if (DEBUG) {
+ System.out.printf("Resolver API: internal lookup call - %s%n", host);
+ }
+
+ // Will remain the same during DNS queries execution
+ ResourceClassType ct = ResourceClassType.fromAddressFamily(addressFamily);
+ ResourceRecords rrs = null;
+
+ // First try to get the resource records with the requested DNS host name if it is FQDN
+ if (host.contains(".")) {
+ rrs = execAddrResolutionQuery(new DnsName(host), ct);
+ }
+ // Non-FQDN or not known host address and domains still can be checked
+ if ((rrs == null || rrs.answer.isEmpty()) && checkDomains) {
+ for (String domain : prepareDomainsSearchList()) {
+ String hostWithSuffix = host + "." + domain;
+ if (DEBUG) {
+ System.err.printf("Resolver API: Trying to lookup:'%s'%n", hostWithSuffix);
+ }
+ rrs = execAddrResolutionQuery(new DnsName(hostWithSuffix), ct);
+ if (rrs != null && !rrs.answer.isEmpty()) {
+ if (DEBUG) {
+ System.err.printf("Resolver API: Found host in '%s' domain%n", domain);
+ }
+ break;
+ }
+ }
+ }
+
+ // If no answers then host is not known in registered domain
+ if (rrs == null || rrs.answer.isEmpty()) {
+ throw new UnknownHostException(host);
+ }
+
+ // Parse answers
+ List<InetAddress> results = new ArrayList<>();
+ for (int i = 0; i < rrs.answer.size(); i++) {
+ ResourceRecord rr = rrs.answer.elementAt(i);
+ int answerType = rr.getType();
+ String recordData = rr.getRdata().toString();
+ if (DEBUG) {
+ System.err.printf("Resolver API: Got %s type: %s%n", ResourceRecord.getTypeName(rr.getType()), rr.getRdata());
+ }
+ if (answerType == ResourceRecord.TYPE_CNAME) {
+ // We've got CNAME entry - issue another request to resolve the canonical host name
+ if (depth > MAX_CNAME_RESOLUTION_DEPTH) {
+ throw new UnknownHostException(host);
+ }
+ List<InetAddress> cnameResults = lookup(recordData, addressFamily, oneIsEnough, false, depth + 1);
+ if (oneIsEnough) {
+ return cnameResults;
+ } else {
+ results.addAll(cnameResults);
+ }
+ } else {
+ byte[] addrBytes;
+ if (answerType == ResourceRecord.TYPE_A && (addressFamily == AddressFamily.IPv4 || addressFamily == AddressFamily.ANY)) {
+ addrBytes = IPAddressUtil.textToNumericFormatV4(recordData);
+ if (addrBytes == null) {
+ if (DEBUG) {
+ System.err.println("Incorrect A resource record answer");
+ }
+ return Collections.emptyList();
+ }
+ } else if (answerType == ResourceRecord.TYPE_AAAA && (addressFamily == AddressFamily.IPv6 || addressFamily == AddressFamily.ANY)) {
+ addrBytes = IPAddressUtil.textToNumericFormatV6(recordData);
+ if (addrBytes == null) {
+ if (DEBUG) {
+ System.err.println("Incorrect AAAA resource record answer");
+ }
+ return Collections.emptyList();
+ }
+ } else {
+ continue;
+ }
+ // IPAddressUtil.textToNumeric can return null
+ if (addrBytes == null) {
+ throw new RuntimeException("Internal error");
+ }
+ InetAddress address = InetAddress.getByAddress(host, addrBytes);
+ results.add(address);
+ if (oneIsEnough) {
+ break;
+ }
+ }
+ }
+
+ return results;
+ }
+
+ // Can return null if query failed
+ private ResourceRecords execAddrResolutionQuery(DnsName name, ResourceClassType ct) {
+ // Not supporting authoritative requests [for now?]
+ try {
+ ResourceRecords rrs = dnsResolver.query(name, ct.getRecordClass(), ct.getRecordType(),
+ true, false);
+ return rrs.hasAddressOrAlias() ? rrs : null;
+ } catch (DnsResolverException e) {
+ if (DEBUG) {
+ System.err.println("Query failed:" + e.getMessage());
+ e.printStackTrace();
+ }
+ return null;
+ }
+ }
+
+ private List<String> rlookup(String literalIP, AddressFamily family) throws DnsResolverException {
+ switch (family) {
+ case IPv4:
+ return ipv4rlookup(literalIP);
+ case IPv6:
+ return ipv6rlookup(literalIP);
+ default:
+ throw new RuntimeException("Only IPv4 and IPv6 addresses are supported");
+ }
+ }
+
+ private List<String> ipv4rlookup(String literalIP) throws DnsResolverException {
+ var request = literalIP + "IN-ADDR.ARPA.";
+ var hostNames = new ArrayList<String>();
+ var name = new DnsName(request);
+ var rrs = dnsResolver.query(name, ResourceRecord.CLASS_INTERNET,
+ ResourceRecord.TYPE_PTR, true, false);
+ for (int i = 0; i < rrs.answer.size(); i++) {
+ ResourceRecord rr = rrs.answer.elementAt(i);
+ hostNames.add(rr.getRdata().toString());
+ }
+ return hostNames;
+ }
+
+ private List<String> ipv6rlookup(String literalIP) throws DnsResolverException {
+ List<String> hostNames = new ArrayList<>();
+ DnsName name = new DnsName(literalIP + "IP6.ARPA.");
+ ResourceRecords rrs = dnsResolver.query(name, ResourceRecord.CLASS_INTERNET,
+ ResourceRecord.TYPE_PTR, true, false);
+ /**
+ * Because RFC 3152 changed the root domain name for reverse
+ * lookups from IP6.INT. to IP6.ARPA., we need to check
+ * both. I.E. first the new one, IP6.ARPA, then if it fails
+ * the older one, IP6.INT
+ */
+ if (rrs.answer.isEmpty()) {
+ name = new DnsName(literalIP + "IP6.INT.");
+ rrs = dnsResolver.query(name, ResourceRecord.CLASS_INTERNET,
+ ResourceRecord.TYPE_PTR, true, false);
+ }
+ for (int i = 0; i < rrs.answer.size(); i++) {
+ ResourceRecord rr = rrs.answer.elementAt(i);
+ hostNames.add(rr.getRdata().toString());
+ }
+ return hostNames;
+ }
+
+ private static String addressToLiteralIP(InetAddress address) {
+ byte[] bytes = address.getAddress();
+ StringBuilder addressBuff = new StringBuilder();
+ // IPv4 address
+ if (bytes.length == 4) {
+ for (int i = bytes.length - 1; i >= 0; i--) {
+ addressBuff.append(bytes[i] & 0xff);
+ addressBuff.append(".");
+ }
+ // IPv6 address
+ } else if (bytes.length == 16) {
+ for (int i = bytes.length - 1; i >= 0; i--) {
+ addressBuff.append(Integer.toHexString((bytes[i] & 0x0f)));
+ addressBuff.append(".");
+ addressBuff.append(Integer.toHexString((bytes[i] & 0xf0) >> 4));
+ addressBuff.append(".");
+ }
+ } else {
+ return null;
+ }
+ return addressBuff.toString();
+ }
+
+ private static DnsResolverConfiguration dnsResolverConfiguration = new DnsResolverConfiguration();
+ private static HostsFileResolver hostsFileResolver = new HostsFileResolver();
+
+ // TODO: Add system property with the sequence of resolution OR nsswitch.conf location to get the order:
+ // file, name
+ private final Resolver dnsResolver;
+ private static final boolean DEBUG = java.security.AccessController.doPrivileged(
+ (PrivilegedAction<Boolean>) () -> Boolean.getBoolean("jdk.dns.client.debug"));
+ private static final int MAX_CNAME_RESOLUTION_DEPTH = 4;
+}