src/jdk.dns.client/share/classes/jdk/dns/client/NetworkNamesResolver.java
branchaefimov-dns-client-branch
changeset 58971 465a15dd6bed
parent 58870 35c438a6d45c
child 58984 15e026239a6c
--- a/src/jdk.dns.client/share/classes/jdk/dns/client/NetworkNamesResolver.java	Thu Nov 07 18:44:09 2019 +0000
+++ b/src/jdk.dns.client/share/classes/jdk/dns/client/NetworkNamesResolver.java	Thu Nov 07 18:46:06 2019 +0000
@@ -26,76 +26,58 @@
 package jdk.dns.client;
 
 import jdk.dns.client.ex.DnsResolverException;
-import jdk.dns.client.internal.DnsName;
+import jdk.dns.client.internal.AddressResolutionQueue;
+import jdk.dns.client.internal.DnsResolver;
 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;
+    private final ProtocolFamily protocolFamily;
 
     public static NetworkNamesResolver open() throws UnknownHostException {
-        return new NetworkNamesResolver(AddressFamily.ANY);
+        // null for any (IPv4+IPv6) addresses family
+        return new NetworkNamesResolver(null);
     }
 
     public static NetworkNamesResolver open(ProtocolFamily protocolFamily) throws UnknownHostException {
-        return new NetworkNamesResolver(AddressFamily.fromProtocolFamily(protocolFamily));
+        return new NetworkNamesResolver(protocolFamily);
     }
 
-    private NetworkNamesResolver(AddressFamily addressFamily) throws UnknownHostException {
-        this.addressFamily = addressFamily;
-        this.dnsResolver = new Resolver(dnsResolverConfiguration.nameservers(), 1000, 4);
+    private NetworkNamesResolver(ProtocolFamily protocolFamily) throws UnknownHostException {
+        this.protocolFamily = protocolFamily;
     }
 
-
     /**
      * 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
+     * @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);
+            return hostsFileResolver.getHostAddress(hostname, protocolFamily);
         } catch (UnknownHostException uhe) {
             if (DEBUG) {
                 System.err.printf("Hosts file doesn't know '%s' host with '%s' address family%n",
-                        hostname, addressFamily.toString());
+                        hostname, protocolFamily == null ? "ANY" : protocolFamily.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);
-            }
+        try (DnsResolver dnsResolver = new DnsResolver()) {
+            var results = lookup(dnsResolver, hostname, protocolFamily, true);
             return results.get(0);
-        } catch (DnsResolverException e) {
-            UnknownHostException uhe = new UnknownHostException(hostname);
-            uhe.initCause(e);
-            throw uhe;
         }
     }
 
@@ -111,22 +93,19 @@
         // First try hosts file
         // TODO: Add nsswitch.conf ReloadTracker and parser to select proper order
         try {
-            return List.of(hostsFileResolver.getHostAddress(hostname));
+            return List.of(hostsFileResolver.getHostAddress(hostname, protocolFamily));
         } 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);
+
+        try (var dnsResolver = new DnsResolver()) {
+            var results = lookup(dnsResolver, hostname, null, false);
             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;
         }
     }
 
@@ -159,10 +138,9 @@
                 System.err.printf("Resolver API: No host in hosts file with %s address%n", address);
             }
         }
-        try {
+        try (DnsResolver dnsResolver = new DnsResolver()) {
             var literalIP = addressToLiteralIP(address);
-            var family = AddressFamily.fromInetAddress(address);
-            var results = rlookup(literalIP, family);
+            var results = dnsResolver.rlookup(literalIP, address);
             if (results.isEmpty()) {
                 throw new UnknownHostException();
             }
@@ -177,176 +155,6 @@
         }
     }
 
-    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();
@@ -356,7 +164,7 @@
                 addressBuff.append(bytes[i] & 0xff);
                 addressBuff.append(".");
             }
-        // IPv6 address
+            // IPv6 address
         } else if (bytes.length == 16) {
             for (int i = bytes.length - 1; i >= 0; i--) {
                 addressBuff.append(Integer.toHexString((bytes[i] & 0x0f)));
@@ -370,13 +178,14 @@
         return addressBuff.toString();
     }
 
-    private static DnsResolverConfiguration dnsResolverConfiguration = new DnsResolverConfiguration();
-    private static HostsFileResolver hostsFileResolver = new HostsFileResolver();
+    private List<InetAddress> lookup(DnsResolver dnsResolver, String host, ProtocolFamily protocolFamily, boolean oneIsEnough) throws UnknownHostException {
+        if (DEBUG) {
+            System.out.printf("Resolver API: internal lookup call - %s%n", host);
+        }
+        return AddressResolutionQueue.resolve(dnsResolver, host, protocolFamily, oneIsEnough);
+    }
 
-    // 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 HostsFileResolver hostsFileResolver = new HostsFileResolver();
     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;
 }