--- /dev/null
+package org.argeo.cms.dns;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.PrintStream;
+import java.util.ArrayList;
+import java.util.Base64;
+import java.util.Collections;
+import java.util.Hashtable;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.SortedSet;
+import java.util.StringJoiner;
+import java.util.TreeMap;
+import java.util.TreeSet;
+
+import javax.naming.Binding;
+import javax.naming.Context;
+import javax.naming.NameNotFoundException;
+import javax.naming.NamingEnumeration;
+import javax.naming.NamingException;
+import javax.naming.directory.Attribute;
+import javax.naming.directory.Attributes;
+import javax.naming.directory.DirContext;
+import javax.naming.directory.InitialDirContext;
+
+public class DnsBrowser implements Closeable {
+ private final DirContext initialCtx;
+
+ public DnsBrowser() {
+ this(new ArrayList<>());
+ }
+
+ public DnsBrowser(List<String> dnsServerUrls) {
+ try {
+ Objects.requireNonNull(dnsServerUrls);
+ Hashtable<String, Object> env = new Hashtable<>();
+ env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.dns.DnsContextFactory");
+ if (!dnsServerUrls.isEmpty()) {
+ boolean specified = false;
+ StringJoiner providerUrl = new StringJoiner(" ");
+ for (String dnsUrl : dnsServerUrls) {
+ if (dnsUrl != null) {
+ providerUrl.add(dnsUrl);
+ specified = true;
+ }
+ }
+ if (specified)
+ env.put(Context.PROVIDER_URL, providerUrl.toString());
+ }
+ initialCtx = new InitialDirContext(env);
+ } catch (NamingException e) {
+ throw new IllegalStateException("Cannot initialise DNS borowser.", e);
+ }
+ }
+
+ public Map<String, List<String>> getAllRecords(String name) {
+ try {
+ Map<String, List<String>> res = new TreeMap<>();
+ Attributes attrs = initialCtx.getAttributes(name);
+ NamingEnumeration<String> ids = attrs.getIDs();
+ while (ids.hasMore()) {
+ String recordType = ids.next();
+ List<String> lst = new ArrayList<String>();
+ res.put(recordType, lst);
+ Attribute attr = attrs.get(recordType);
+ addValues(attr, lst);
+ }
+ return Collections.unmodifiableMap(res);
+ } catch (NamingException e) {
+ throw new IllegalStateException("Cannot get allrecords of " + name, e);
+ }
+ }
+
+ /**
+ * Return a single record (typically A, AAAA, etc. or null if not available.
+ * Will fail if multiple records.
+ */
+ public String getRecord(String name, String recordType) {
+ try {
+ Attributes attrs = initialCtx.getAttributes(name, new String[] { recordType });
+ if (attrs.size() == 0)
+ return null;
+ Attribute attr = attrs.get(recordType);
+ if (attr.size() > 1)
+ throw new IllegalArgumentException("Multiple record type " + recordType);
+ assert attr.size() != 0;
+ Object value = attr.get();
+ assert value != null;
+ return value.toString();
+ } catch (NameNotFoundException e) {
+ return null;
+ } catch (NamingException e) {
+ throw new IllegalStateException("Cannot get DNS entry " + recordType + " of " + name, e);
+ }
+ }
+
+ /**
+ * Return records of a given type.
+ */
+ public List<String> getRecords(String name, String recordType) {
+ try {
+ List<String> res = new ArrayList<String>();
+ Attributes attrs = initialCtx.getAttributes(name, new String[] { recordType });
+ Attribute attr = attrs.get(recordType);
+ addValues(attr, res);
+ return res;
+ } catch (NamingException e) {
+ throw new IllegalStateException("Cannot get records " + recordType + " of " + name, e);
+ }
+ }
+
+ /** Ordered, with preferred first. */
+ public List<String> getSrvRecordsAsHosts(String name, boolean withPort) {
+ List<String> raw = getRecords(name, "SRV");
+ if (raw.size() == 0)
+ return null;
+ SortedSet<SrvRecord> res = new TreeSet<>();
+ for (int i = 0; i < raw.size(); i++) {
+ String record = raw.get(i);
+ String[] arr = record.split(" ");
+ Integer priority = Integer.parseInt(arr[0]);
+ Integer weight = Integer.parseInt(arr[1]);
+ Integer port = Integer.parseInt(arr[2]);
+ String hostname = arr[3];
+ SrvRecord order = new SrvRecord(priority, weight, port, hostname);
+ res.add(order);
+ }
+ List<String> lst = new ArrayList<>();
+ for (SrvRecord order : res) {
+ lst.add(order.toHost(withPort));
+ }
+ return Collections.unmodifiableList(lst);
+ }
+
+ private void addValues(Attribute attr, List<String> lst) throws NamingException {
+ NamingEnumeration<?> values = attr.getAll();
+ while (values.hasMore()) {
+ Object value = values.next();
+ if (value != null) {
+ if (value instanceof byte[]) {
+ String str = Base64.getEncoder().encodeToString((byte[]) value);
+ lst.add(str);
+ } else
+ lst.add(value.toString());
+ }
+ }
+
+ }
+
+ public List<String> listEntries(String name) {
+ try {
+ List<String> res = new ArrayList<String>();
+ NamingEnumeration<Binding> ne = initialCtx.listBindings(name);
+ while (ne.hasMore()) {
+ Binding b = ne.next();
+ res.add(b.getName());
+ }
+ return Collections.unmodifiableList(res);
+ } catch (NamingException e) {
+ throw new IllegalStateException("Cannot list entries of " + name, e);
+ }
+ }
+
+ @Override
+ public void close() throws IOException {
+ destroy();
+ }
+
+ public void destroy() {
+ try {
+ initialCtx.close();
+ } catch (NamingException e) {
+ // silent
+ }
+ }
+
+ public static void main(String[] args) {
+ if (args.length == 0) {
+ printUsage(System.err);
+ System.exit(1);
+ }
+ try (DnsBrowser dnsBrowser = new DnsBrowser()) {
+ String hostname = args[0];
+ String recordType = args.length > 1 ? args[1] : "A";
+ if (recordType.equals("*")) {
+ Map<String, List<String>> records = dnsBrowser.getAllRecords(hostname);
+ for (String type : records.keySet()) {
+ for (String record : records.get(type)) {
+ String typeLabel;
+ if ("44".equals(type))
+ typeLabel = "SSHFP";
+ else if ("46".equals(type))
+ typeLabel = "RRSIG";
+ else if ("48".equals(type))
+ typeLabel = "DNSKEY";
+ else
+ typeLabel = type;
+ System.out.println(typeLabel + "\t" + record);
+ }
+ }
+ } else {
+ System.out.println(dnsBrowser.getRecord(hostname, recordType));
+ }
+
+ } catch (Exception e) {
+ e.printStackTrace();
+ }
+ }
+
+ public static void printUsage(PrintStream out) {
+ out.println("java org.argeo.naming.DnsBrowser <hostname> [<record type> | *]");
+ }
+
+}
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projects / lgpl / argeo-commons.git / blobdiff