NetDB:

- Just before midnight, flood to new location too so lookups
   don't fail after keyspace rotation (ticket #510)
 - Refactor RoutingKeyGenerator and UpdateRoutingKeyModifierJob
   in support of the above
 - Display next key on LS debug page

apps/routerconsole/java/src/net/i2p/router/web/NetDbRenderer.java

@@ -195,6 +195,8 @@ public class NetDbRenderer {
             buf.append("</b></p><p><b>Published (RAP) Leasesets: ").append(netdb.getKnownLeaseSets());
             buf.append("</b></p><p><b>Mod Data: \"").append(DataHelper.getUTF8(_context.routingKeyGenerator().getModData()))
                .append("\" Last Changed: ").append(new Date(_context.routingKeyGenerator().getLastChanged()));
+            buf.append("</b></p><p><b>Next Mod Data: \"").append(DataHelper.getUTF8(_context.routingKeyGenerator().getNextModData()))
+               .append("\" Change in: ").append(DataHelper.formatDuration(_context.routingKeyGenerator().getTimeTillMidnight()));
             int ff = _context.peerManager().getPeersByCapability(FloodfillNetworkDatabaseFacade.CAPABILITY_FLOODFILL).size();
             buf.append("</b></p><p><b>Known Floodfills: ").append(ff);
             buf.append("</b></p><p><b>Currently Floodfill? ");

core/java/src/net/i2p/data/DatabaseEntry.java

@@ -107,15 +107,17 @@ public abstract class DatabaseEntry extends DataStructureImpl {
      */
     public Hash getRoutingKey() {
         RoutingKeyGenerator gen = RoutingKeyGenerator.getInstance();
-        if ((gen.getModData() == null) || (_routingKeyGenMod == null)
+        byte[] mod = gen.getModData();
-            || (!DataHelper.eq(gen.getModData(), _routingKeyGenMod))) {
+        if (!DataHelper.eq(mod, _routingKeyGenMod)) {
             _currentRoutingKey = gen.getRoutingKey(getHash());
-            _routingKeyGenMod = gen.getModData();
+            _routingKeyGenMod = mod;
         }
         return _currentRoutingKey;
     }
 
-
+    /**
+     * @deprecated unused
+     */
     public void setRoutingKey(Hash key) {
         _currentRoutingKey = key;
     }

core/java/src/net/i2p/data/RoutingKeyGenerator.java

@@ -17,6 +17,7 @@ import java.util.TimeZone;
 
 import net.i2p.I2PAppContext;
 import net.i2p.crypto.SHA256Generator;
+import net.i2p.util.HexDump;
 import net.i2p.util.Log;
 
 /**
@@ -37,6 +38,8 @@ import net.i2p.util.Log;
  * Also - the method generateDateBasedModData() should be called after midnight GMT 
  * once per day to generate the correct routing keys!
  *
+ * Warning - API subject to change. Not for use outside the router.
+ *
  */
 public class RoutingKeyGenerator {
     private final Log _log;
@@ -54,6 +57,8 @@ public class RoutingKeyGenerator {
     }
     
     private volatile byte _currentModData[];
+    private volatile byte _nextModData[];
+    private volatile long _nextMidnight;
     private volatile long _lastChanged;
 
     private final static Calendar _cal = GregorianCalendar.getInstance(TimeZone.getTimeZone("GMT"));
@@ -61,14 +66,74 @@ public class RoutingKeyGenerator {
     private static final int LENGTH = FORMAT.length();
     private final static SimpleDateFormat _fmt = new SimpleDateFormat(FORMAT);
 
+    /**
+     *  The current (today's) mod data.
+     *  Warning - not a copy, do not corrupt.
+     *
+     *  @return non-null, 8 bytes
+     */
     public byte[] getModData() {
         return _currentModData;
     }
 
+    /**
+     *  Tomorrow's mod data.
+     *  Warning - not a copy, do not corrupt.
+     *  For debugging use only.
+     *
+     *  @return non-null, 8 bytes
+     *  @since 0.9.10
+     */
+    public byte[] getNextModData() {
+        return _nextModData;
+    }
+
     public long getLastChanged() {
         return _lastChanged;
     }
 
+    /**
+     *  How long until midnight (ms)
+     *
+     *  @return could be slightly negative
+     *  @since 0.9.10 moved from UpdateRoutingKeyModifierJob
+     */
+    public long getTimeTillMidnight() {
+        return _nextMidnight - _context.clock().now();
+    }
+
+    /**
+     *  Set _cal to midnight for the time given.
+     *  Caller must synch.
+     *  @since 0.9.10
+     */
+    private void setCalToPreviousMidnight(long now) {
+            _cal.setTime(new Date(now));
+            _cal.set(Calendar.YEAR, _cal.get(Calendar.YEAR));               // gcj <= 4.0 workaround
+            _cal.set(Calendar.DAY_OF_YEAR, _cal.get(Calendar.DAY_OF_YEAR)); // gcj <= 4.0 workaround
+            _cal.set(Calendar.HOUR_OF_DAY, 0);
+            _cal.set(Calendar.MINUTE, 0);
+            _cal.set(Calendar.SECOND, 0);
+            _cal.set(Calendar.MILLISECOND, 0);
+    }
+
+    /**
+     *  Generate mod data from _cal.
+     *  Caller must synch.
+     *  @since 0.9.10
+     */
+    private byte[] generateModDataFromCal() {
+        Date today = _cal.getTime();
+        
+        String modVal = _fmt.format(today);
+        if (modVal.length() != LENGTH)
+            throw new IllegalStateException();
+        byte[] mod = new byte[LENGTH];
+        for (int i = 0; i < LENGTH; i++)
+            mod[i] = (byte)(modVal.charAt(i) & 0xFF);
+        return mod;
+    }
+
     /**
      * Update the current modifier data with some bytes derived from the current
      * date (yyyyMMdd in GMT)
@@ -77,34 +142,26 @@ public class RoutingKeyGenerator {
      */
     public synchronized boolean generateDateBasedModData() {
         long now = _context.clock().now();
-            _cal.setTime(new Date(now));
+        setCalToPreviousMidnight(now);
-            _cal.set(Calendar.YEAR, _cal.get(Calendar.YEAR));               // gcj <= 4.0 workaround
+        byte[] mod = generateModDataFromCal();
-            _cal.set(Calendar.DAY_OF_YEAR, _cal.get(Calendar.DAY_OF_YEAR)); // gcj <= 4.0 workaround
-            _cal.set(Calendar.HOUR_OF_DAY, 0);
-            _cal.set(Calendar.MINUTE, 0);
-            _cal.set(Calendar.SECOND, 0);
-            _cal.set(Calendar.MILLISECOND, 0);
-        Date today = _cal.getTime();
-        
-        String modVal = _fmt.format(today);
-        if (modVal.length() != LENGTH)
-            throw new IllegalStateException();
-        byte[] mod = new byte[LENGTH];
-        for (int i = 0; i < LENGTH; i++)
-            mod[i] = (byte)(modVal.charAt(i) & 0xFF);
         boolean changed = !DataHelper.eq(_currentModData, mod);
         if (changed) {
+            // add a day and store next midnight and mod data for convenience
+            _cal.add(Calendar.DATE, 1);
+            _nextMidnight = _cal.getTime().getTime();
+            byte[] next = generateModDataFromCal();
             _currentModData = mod;
+            _nextModData = next;
             _lastChanged = now;
             if (_log.shouldLog(Log.INFO))
-                _log.info("Routing modifier generated: " + modVal);
+                _log.info("Routing modifier generated: " + HexDump.dump(mod));
         }
         return changed;
     }
     
     /**
      * Generate a modified (yet consistent) hash from the origKey by generating the
-     * SHA256 of the targetKey with the current modData appended to it, *then* 
+     * SHA256 of the targetKey with the current modData appended to it
      *
      * This makes Sybil's job a lot harder, as she needs to essentially take over the
      * whole keyspace.
@@ -112,10 +169,29 @@ public class RoutingKeyGenerator {
      * @throws IllegalArgumentException if origKey is null
      */
     public Hash getRoutingKey(Hash origKey) {
+        return getKey(origKey, _currentModData);
+    }
+    
+    /**
+     * Get the routing key using tomorrow's modData, not today's
+     *
+     * @since 0.9.10
+     */
+    public Hash getNextRoutingKey(Hash origKey) {
+        return getKey(origKey, _nextModData);
+    }
+    
+    /**
+     * Generate a modified (yet consistent) hash from the origKey by generating the
+     * SHA256 of the targetKey with the specified modData appended to it
+     *
+     * @throws IllegalArgumentException if origKey is null
+     */
+    private static Hash getKey(Hash origKey, byte[] modData) {
         if (origKey == null) throw new IllegalArgumentException("Original key is null");
         byte modVal[] = new byte[Hash.HASH_LENGTH + LENGTH];
         System.arraycopy(origKey.getData(), 0, modVal, 0, Hash.HASH_LENGTH);
-        System.arraycopy(_currentModData, 0, modVal, Hash.HASH_LENGTH, LENGTH);
+        System.arraycopy(modData, 0, modVal, Hash.HASH_LENGTH, LENGTH);
         return SHA256Generator.getInstance().calculateHash(modVal);
     }
 

history.txt

@@ -1,3 +1,10 @@
+2013-12-14 zzz
+* NetDB:
+ - Just before midnight, flood to new location too so lookups
+   don't fail after keyspace rotation (ticket #510)
+ - Refactor RoutingKeyGenerator and UpdateRoutingKeyModifierJob
+   in support of the above
+
 2013-12-13 zzz
  * i2ptunnel: Show destination for persistent client key only if available;
               show b32 for the key as well

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 = 2;
+    public final static long BUILD = 3;
 
     /** for example "-test" */
     public final static String EXTRA = "";

router/java/src/net/i2p/router/networkdb/kademlia/FloodfillNetworkDatabaseFacade.java

@@ -43,6 +43,9 @@ public class FloodfillNetworkDatabaseFacade extends KademliaNetworkDatabaseFacad
     
     private static final int FLOOD_PRIORITY = OutNetMessage.PRIORITY_NETDB_FLOOD;
     private static final int FLOOD_TIMEOUT = 30*1000;
+    private static final long NEXT_RKEY_RI_ADVANCE_TIME = 45*60*1000;
+    private static final long NEXT_RKEY_LS_ADVANCE_TIME = 10*60*1000;
+    private static final int NEXT_FLOOD_QTY = 2;
     
     public FloodfillNetworkDatabaseFacade(RouterContext context) {
         super(context);
@@ -197,6 +200,23 @@ public class FloodfillNetworkDatabaseFacade extends KademliaNetworkDatabaseFacad
         Hash rkey = _context.routingKeyGenerator().getRoutingKey(key);
         FloodfillPeerSelector sel = (FloodfillPeerSelector)getPeerSelector();
         List<Hash> peers = sel.selectFloodfillParticipants(rkey, MAX_TO_FLOOD, getKBuckets());
+        long until = _context.routingKeyGenerator().getTimeTillMidnight();
+        if (until < NEXT_RKEY_LS_ADVANCE_TIME ||
+            (ds.getType() == DatabaseEntry.KEY_TYPE_ROUTERINFO && until < NEXT_RKEY_RI_ADVANCE_TIME)) {
+            // to avoid lookup failures after midnight, also flood to some closest to the
+            // next routing key for a period of time before midnight.
+            Hash nkey = _context.routingKeyGenerator().getNextRoutingKey(key);
+            List<Hash> nextPeers = sel.selectFloodfillParticipants(nkey, NEXT_FLOOD_QTY, getKBuckets());
+            int i = 0;
+            for (Hash h : nextPeers) {
+                if (!peers.contains(h)) {
+                    peers.add(h);
+                    i++;
+                }
+            }
+            if (i > 0 && _log.shouldLog(Log.INFO))
+                _log.info("Flooding the entry for " + key + " to " + i + " more, just before midnight");
+        }
         int flooded = 0;
         for (int i = 0; i < peers.size(); i++) {
             Hash peer = peers.get(i);

router/java/src/net/i2p/router/tasks/UpdateRoutingKeyModifierJob.java

@@ -8,11 +8,7 @@ package net.i2p.router.tasks;
  *
  */
 
-import java.util.Calendar;
+import net.i2p.data.RoutingKeyGenerator;
-import java.util.Date;
-import java.util.GregorianCalendar;
-import java.util.TimeZone;
-
 import net.i2p.router.JobImpl;
 import net.i2p.router.RouterContext;
 import net.i2p.util.Log;
@@ -26,7 +22,6 @@ import net.i2p.util.Log;
  */
 public class UpdateRoutingKeyModifierJob extends JobImpl {
     private final Log _log;
-    private final Calendar _cal = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
     // Run every 15 minutes in case of time zone change, clock skew, etc.
     private static final long MAX_DELAY_FAILSAFE = 15*60*1000;
 
@@ -38,29 +33,11 @@ public class UpdateRoutingKeyModifierJob extends JobImpl {
     public String getName() { return "Update Routing Key Modifier"; }
 
     public void runJob() {
+        RoutingKeyGenerator gen = getContext().routingKeyGenerator();
         // make sure we requeue quickly if just before midnight
-        long delay = Math.min(MAX_DELAY_FAILSAFE, getTimeTillMidnight());
+        long delay = Math.max(5, Math.min(MAX_DELAY_FAILSAFE, gen.getTimeTillMidnight()));
         // TODO tell netdb if mod data changed?
-        getContext().routingKeyGenerator().generateDateBasedModData();
+        gen.generateDateBasedModData();
         requeue(delay);
     }
-
-    private long getTimeTillMidnight() {
-        long now = getContext().clock().now();
-        _cal.setTime(new Date(now));
-        _cal.set(Calendar.YEAR, _cal.get(Calendar.YEAR));               // gcj <= 4.0 workaround
-        _cal.set(Calendar.DAY_OF_YEAR, _cal.get(Calendar.DAY_OF_YEAR)); // gcj <= 4.0 workaround
-        _cal.add(Calendar.DATE, 1);
-        _cal.set(Calendar.HOUR_OF_DAY, 0);
-        _cal.set(Calendar.MINUTE, 0);
-        _cal.set(Calendar.SECOND, 0);
-        _cal.set(Calendar.MILLISECOND, 0);
-        long then = _cal.getTime().getTime();
-        long howLong = then - now;
-        if (howLong < 0) // hi kaffe
-            howLong = 24*60*60*1000l + howLong;
-        if (_log.shouldLog(Log.DEBUG))
-            _log.debug("Time till midnight: " + howLong + "ms");
-        return howLong;
-    }
 }