SSU:

- Sort introducers in router address, so we won't force a republish
due to a different ordering of the same introducers
- Don't publish an address if we need introducers but don't have any,
so the user won't see a 'firewalled with inbound NTCP enabled' message

history.txt

@@ -1,5 +1,10 @@
 2015-01-29 zzz
- * SSU: Fix replaceExternalAddress churn when firewalled
+ * SSU:
+   - Fix replaceExternalAddress churn when firewalled
+   - Sort introducers in router address, so we won't force a republish
+     due to a different ordering of the same introducers
+   - Don't publish an address if we need introducers but don't have any,
+     so the user won't see a 'firewalled with inbound NTCP enabled' message
 
 2015-01-28 zzz
  * UPnP:

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 = 13;
+    public final static long BUILD = 14;
 
     /** for example "-test" */
     public final static String EXTRA = "";

router/java/src/net/i2p/router/transport/udp/IntroductionManager.java

@@ -3,6 +3,7 @@ package net.i2p.router.transport.udp;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -176,6 +177,7 @@ class IntroductionManager {
         // if not too many to choose from, be less picky
         if (sz <= howMany + 2)
             inactivityCutoff -= UDPTransport.EXPIRE_TIMEOUT / 4;
+        List<Introducer> introducers = new ArrayList<Introducer>(howMany);
         for (int i = 0; i < sz && found < howMany; i++) {
             PeerState cur = peers.get((start + i) % sz);
             RouterInfo ri = _context.netDb().lookupRouterInfoLocally(cur.getRemotePeer());
@@ -222,19 +224,45 @@ class IntroductionManager {
             byte[] ikey = ura.getIntroKey();
             if (ikey == null)
                 continue;
-            ssuOptions.setProperty(UDPAddress.PROP_INTRO_HOST_PREFIX + found, Addresses.toString(ip));
-            ssuOptions.setProperty(UDPAddress.PROP_INTRO_PORT_PREFIX + found, String.valueOf(port));
-            ssuOptions.setProperty(UDPAddress.PROP_INTRO_KEY_PREFIX + found, Base64.encode(ikey));
-            ssuOptions.setProperty(UDPAddress.PROP_INTRO_TAG_PREFIX + found, String.valueOf(cur.getTheyRelayToUsAs()));
+            introducers.add(new Introducer(ip, port, ikey, cur.getTheyRelayToUsAs()));
             found++;
         }
 
+        // we sort them so a change in order only won't happen, and won't cause a republish
+        Collections.sort(introducers);
+        for (int i = 0; i < found; i++) {
+            Introducer in = introducers.get(i);
+            ssuOptions.setProperty(UDPAddress.PROP_INTRO_HOST_PREFIX + i, in.sip);
+            ssuOptions.setProperty(UDPAddress.PROP_INTRO_PORT_PREFIX + i, in.sport);
+            ssuOptions.setProperty(UDPAddress.PROP_INTRO_KEY_PREFIX + i, in.skey);
+            ssuOptions.setProperty(UDPAddress.PROP_INTRO_TAG_PREFIX + i, in.stag);
+        }
+
         // FIXME failsafe if found == 0, relax inactivityCutoff and try again?
 
         pingIntroducers();
         return found;
     }
 
+    /**
+     *  So we can sort them
+     *  @since 0.9.18
+     */
+    private static class Introducer implements Comparable<Introducer> {
+        public final String sip, sport, skey, stag;
+
+        public Introducer(byte[] ip, int port, byte[] key, long tag) {
+            sip = Addresses.toString(ip);
+            sport = String.valueOf(port);
+            skey = Base64.encode(key);
+            stag = String.valueOf(tag);
+        }
+
+        public int compareTo(Introducer i) {
+            return skey.compareTo(i.skey);
+        }
+    }
+
     /**
      *  Was part of pickInbound(), moved out so we can call it more often
      *  @since 0.8.11

router/java/src/net/i2p/router/transport/udp/UDPTransport.java

@@ -1878,9 +1878,9 @@ public class UDPTransport extends TransportImpl implements TimedWeightedPriority
 
         boolean introducersIncluded = false;
         if (introducersRequired) {
-            // FIXME intro manager doesn't sort introducers, so
-            // deepEquals() below can fail even with same introducers.
-            // Only a problem when we have very very few peers to pick from.
+            // intro manager now sorts introducers, so
+            // deepEquals() below will not fail even with same introducers.
+            // Was only a problem when we had very very few peers to pick from.
             int found = _introManager.pickInbound(options, PUBLIC_RELAY_COUNT);
             if (found > 0) {
                 if (_log.shouldLog(Log.INFO))
@@ -1974,6 +1974,15 @@ public class UDPTransport extends TransportImpl implements TimedWeightedPriority
                 _log.warn("Wanted to rebuild my SSU address, but couldn't specify either the direct or indirect info (needs introducers? " 
                            + introducersRequired + ")", new Exception("source"));
             _needsRebuild = true;
+            if (hasCurrentAddress()) {
+                // We must remove current address, otherwise the user will see
+                // "firewalled with inbound NTCP enabled" warning in console.
+                // Unfortunately this will remove any IPv6 also,
+                // but we don't have a method to remove just the IPv4 address. FIXME
+                replaceAddress(null);
+                if (allowRebuildRouterInfo)
+                    _context.router().rebuildRouterInfo();
+            }
             return null;
         }
     }