Router: The first time we see a peer who is requesting tunnels from a…

… router with the G Capabilities, reply with an updated routerInfo to give them a chance to stop. If they don't, ban them after a little while.

router/java/src/net/i2p/router/tunnel/pool/BuildHandler.java

@@ -11,6 +11,7 @@
 import net.i2p.data.DataHelper;
 import net.i2p.data.EmptyProperties;
 import net.i2p.data.Hash;
+import net.i2p.data.i2np.DatabaseStoreMessage;
 import net.i2p.data.router.RouterIdentity;
 import net.i2p.data.router.RouterInfo;
 import net.i2p.data.TunnelId;
@@ -470,6 +471,48 @@ private long handleRequest(BuildMessageState state, long now) {
             _context.commSystem().mayDisconnect(from);
             return -1;
         }
+        // get my own RouterInfo
+        RouterInfo myRI = _context.router().getRouterInfo();
+        if (myRI != null) {
+            String caps = myRI.getCapabilities();
+            if (caps != null) {
+                if (caps.indexOf(Router.CAPABILITY_NO_TUNNELS) >= 0){
+                    _context.statManager().addRateData("tunnel.dropTunnelFromCongestionCapability", 1);
+                    if (_log.shouldLog(Log.WARN))
+                        _log.warn("Drop request, we are denying tunnels due to congestion: " + from);
+                    RouterInfo fromRI = _context.floodfillNetDb().lookupRouterInfoLocally(from);
+                    if (fromRI != null){
+                        String fromVersion = fromRI.getVersion();
+                        // if fromVersion is greater than 0.9.58, then then ban the router due to it disrespecting our
+                        // congestion flags
+                        if (fromVersion != null){
+                            if (VersionComparator.comp(fromVersion, MIN_VERSION_HONOR_CAPS) >= 0) {
+                                _context.statManager().addRateData("tunnel.dropTunnelFromVersion"+from, 1);
+                                long knocks = _context.statManager().getRate("tunnel.dropTunnelFromVersion"+from).getLifetimeEventCount();
+                                if (knocks > 10) {
+                                    if (_log.shouldLog(Log.WARN))
+                                        _log.warn("Banning peer: " + fromRI.getHash() + " due to it disrespecting our congestion flags");
+                                    _context.banlist().banlistRouter(from, "disrespected our tunnel flags", null, false);    
+                                } else if (knocks <= 1) {
+                                    if (_log.shouldLog(Log.WARN))
+                                        _log.warn("Replying with our RouterInfo to peer:" +fromRI.getHash() + 
+                                            " to give it a chance to update their own netDb and stop asking for new tunnels");
+                                    // send the peer our RouterInfo
+                                    int TIMEOUT = 10*1000;
+                                    DatabaseStoreMessage dsm = new DatabaseStoreMessage(_context);
+                                    dsm.setMessageExpiration(_context.clock().now() + TIMEOUT);
+                                    dsm.setEntry(myRI);
+                                    OutNetMessage outMsg = new OutNetMessage(_context, dsm, _context.clock().now() + TIMEOUT, PRIORITY, fromRI);
+                                    _context.outNetMessagePool().add(outMsg);
+                                }
+
+                            }
+                        }
+                    }
+                    return -1;
+                }
+            }
+        }
 
         if (timeSinceReceived > (BuildRequestor.REQUEST_TIMEOUT*3)) {
             // don't even bother, since we are so overloaded locally