NTP: Enable IPv6 support (ticket #1896)

core/java/src/net/i2p/util/Addresses.java

@@ -58,6 +58,19 @@ public abstract class Addresses {
         return !getAddresses(true, false, false).isEmpty();
     }
 
+    /**
+     *  Do we have any non-loop, non-wildcard IPv6 address at all?
+     *  @since 0.9.29
+     */
+    public static boolean isConnectedIPv6() {
+        // not as good as using a Java DBus implementation to talk to NetworkManager...
+        for (String ip : getAddresses(false, true)) {
+            if (ip.contains(":"))
+                return true;
+        }
+        return false;
+    }
+
     /** @return the first non-local address IPv4 address it finds, or null */
     public static String getAnyAddress() {
         SortedSet<String> a = getAddresses();
@@ -599,6 +612,7 @@ public abstract class Addresses {
             } catch (UnknownHostException uhe) {}
             System.out.println(buf.toString());
         }
-        System.out.println("\nIs connected? " + isConnected());
+        System.out.println("\nIs connected? " + isConnected() +
+                           "\nHas IPv6?     " + isConnectedIPv6());
     }
 }

history.txt

@@ -1,3 +1,19 @@
+2017-02-04 zzz
+ * NTP: Enable IPv6 support (ticket #1896)
+
+2017-01-30 zzz
+ * Router: Run shutdown tasks in parallel,
+   increase max time for shutdown tasks (ticket #1893)
+   i2psnark: Remove most delay between announces at shutdown
+
+2017-01-29 zzz
+ * i2ptunnel CONNECT proxy:
+   - Add support for outproxy plugin (tickets #1364, #1895)
+   - Add support for ports
+
+2017-01-28 zzz
+ * Utils: Detect when running as service on Gentoo
+
 2017-01-26 zzz
  * Build: Set up translations for man pages
  * Javadoc: Fixes (ticket #1894)
@@ -41,8 +57,8 @@
  * NTP:
    - Verify source address and port
    - Add to command line
-   - Add KoD support (ticket #1896)
-   - Add initial IPv6 support (ticket #1897)
+   - Add KoD support (ticket #1897)
+   - Add initial IPv6 support (ticket #1896)
 
 2016-12-20 zzz
  * Build: Fix installer compile failure

router/java/src/net/i2p/router/RouterVersion.java

@@ -18,7 +18,7 @@ public class RouterVersion {
     /** deprecated */
     public final static String ID = "Monotone";
     public final static String VERSION = CoreVersion.VERSION;
-    public final static long BUILD = 4;
+    public final static long BUILD = 5;
 
     /** for example "-test" */
     public final static String EXTRA = "";

router/java/src/net/i2p/router/time/RouterTimestamper.java

@@ -8,6 +8,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 
 import net.i2p.I2PAppContext;
 import net.i2p.time.Timestamper;
+import net.i2p.util.Addresses;
 import net.i2p.util.I2PThread;
 import net.i2p.util.Log;
 
@@ -173,6 +174,7 @@ public class RouterTimestamper extends Timestamper {
             while (_isRunning) {
                 // NOTE: _log is null the first time through, to prevent problems and stack overflows
                 updateConfig();
+                boolean preferIPv6 = Addresses.isConnectedIPv6();
                 if (!_disabled) {
                     // first the servers for our country and continent, we know what country we're in...
                     if (_priorityServers != null) {
@@ -180,7 +182,7 @@ public class RouterTimestamper extends Timestamper {
                             if (_log != null && _log.shouldDebug())
                                 _log.debug("Querying servers " + servers);
                             try {
-                                lastFailed = !queryTime(servers.toArray(new String[servers.size()]), SHORT_TIMEOUT);
+                                lastFailed = !queryTime(servers.toArray(new String[servers.size()]), SHORT_TIMEOUT, preferIPv6);
                             } catch (IllegalArgumentException iae) {
                                 if (!lastFailed && _log != null && _log.shouldWarn())
                                     _log.warn("Unable to reach any regional NTP servers: " + servers);
@@ -195,7 +197,10 @@ public class RouterTimestamper extends Timestamper {
                         if (_log != null && _log.shouldDebug())
                             _log.debug("Querying servers " + _servers);
                         try {
-                            lastFailed = !queryTime(_servers.toArray(new String[_servers.size()]), DEFAULT_TIMEOUT);
+                            // If we failed, maybe it's because IPv6 is blocked, so try IPv4 only
+                            // also first time through, and randomly
+                            boolean prefIPv6 = preferIPv6 && !lastFailed && _log != null && _context.random().nextInt(4) != 0;
+                            lastFailed = !queryTime(_servers.toArray(new String[_servers.size()]), DEFAULT_TIMEOUT, prefIPv6);
                         } catch (IllegalArgumentException iae) {
                             lastFailed = true;
                         }
@@ -262,7 +267,7 @@ public class RouterTimestamper extends Timestamper {
     /**
      * True if the time was queried successfully, false if it couldn't be
      */
-    private boolean queryTime(String serverList[], int perServerTimeout) throws IllegalArgumentException {
+    private boolean queryTime(String serverList[], int perServerTimeout, boolean preferIPv6) throws IllegalArgumentException {
         long found[] = new long[_concurringServers];
         long now = -1;
         int stratum = -1;
@@ -273,8 +278,7 @@ public class RouterTimestamper extends Timestamper {
             //    // this delays startup when net is disconnected or the timeserver list is bad, don't make it too long
             //    try { Thread.sleep(2*1000); } catch (InterruptedException ie) {}
             //}
-            // IPv6 arg TODO
-            long[] timeAndStratum = NtpClient.currentTimeAndStratum(serverList, perServerTimeout, false, _log);
+            long[] timeAndStratum = NtpClient.currentTimeAndStratum(serverList, perServerTimeout, preferIPv6, _log);
             now = timeAndStratum[0];
             stratum = (int) timeAndStratum[1];
             long delta = now - _context.clock().now();