From b20496e42bdf3a8d755de6b5385f4fae82c3fb50 Mon Sep 17 00:00:00 2001
From: theli <theli@6c8d7289-2bf4-0310-a012-ef5d649a1542>
Date: Wed, 21 Jun 2006 19:28:42 +0000
Subject: [PATCH] *) make DHT DoS check configurable (requested by KoH)    -
 check can be disabled via property indexDistribution.dhtReceiptLimitEnabled  
  - upper bound can be configured via indexDistribution.dhtReceiptLimit

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@2234 6c8d7289-2bf4-0310-a012-ef5d649a1542
---
 htroot/yacy/transferRWI.java                   | 11 ++++++++---
 source/de/anomic/plasma/plasmaDHTTransfer.java |  3 ++-
 yacy.init                                      |  8 ++++++++
 3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/htroot/yacy/transferRWI.java b/htroot/yacy/transferRWI.java
index 510749299..fb7346da0 100644
--- a/htroot/yacy/transferRWI.java
+++ b/htroot/yacy/transferRWI.java
@@ -78,8 +78,10 @@ public final class transferRWI {
         final int entryc      = Integer.parseInt(post.get("entryc", "")); // number of entries in indexes
         byte[] indexes        = post.get("indexes", "").getBytes();       // the indexes, as list of word entries
         boolean granted       = sb.getConfig("allowReceiveIndex", "false").equals("true");
+        boolean checkLimit    = sb.getConfigBool("indexDistribution.dhtReceiptLimitEnabled", true);
+        final long cachelimit = sb.getConfigLong("indexDistribution.dhtReceiptLimit", 1000);
         final yacySeed otherPeer = yacyCore.seedDB.get(iam);
-        final String otherPeerName = iam + ":" + ((otherPeer == null) ? "NULL" : (otherPeer.getName() + "/" + otherPeer.getVersion()));        
+        final String otherPeerName = iam + ":" + ((otherPeer == null) ? "NULL" : (otherPeer.getName() + "/" + otherPeer.getVersion()));                
         
         // response values
         String       result      = "ok";
@@ -91,7 +93,7 @@ public final class transferRWI {
             sb.getLog().logInfo("Rejecting RWIs from peer " + otherPeerName + ". Not granted.");
             result = "not_granted";
             pause = 0;
-        } else if (sb.wordIndex.kSize() > 1000) {
+        } else if (checkLimit && sb.wordIndex.kSize() > cachelimit) {
             // we are too busy to receive indexes
             sb.getLog().logInfo("Rejecting RWIs from peer " + otherPeerName + ". We are too busy (buffersize=" + sb.wordIndex.kSize() + ").");
             granted = false; // don't accept more words if there are too many words to flush
@@ -171,7 +173,10 @@ public final class transferRWI {
                 sb.getLog().logInfo("Received " + received + " Words [" + wordhashes[0] + " .. " + wordhashes[received - 1] + "]/" + avdist + " from " + otherPeerName + ", processed in " + (System.currentTimeMillis() - startProcess) + " milliseconds, requesting " + unknownURL.size() + " URLs");
             }
             result = "ok";
-            pause = (sb.wordIndex.kSize() < 500) ? 0 : 60 * sb.wordIndex.kSize(); // estimation of necessary pause time
+            
+            if (checkLimit) {
+                pause = (sb.wordIndex.kSize() < 500) ? 0 : 60 * sb.wordIndex.kSize(); // estimation of necessary pause time
+            }
         }
 
         prop.put("unknownURL", unknownURLs.toString());
diff --git a/source/de/anomic/plasma/plasmaDHTTransfer.java b/source/de/anomic/plasma/plasmaDHTTransfer.java
index b686a6665..7d40dedfd 100644
--- a/source/de/anomic/plasma/plasmaDHTTransfer.java
+++ b/source/de/anomic/plasma/plasmaDHTTransfer.java
@@ -258,13 +258,14 @@ public class plasmaDHTTransfer extends Thread {
         if (transferRWIResult != null && transferRWIResult.containsKey("pause")) {
             String pauseStr = (String) transferRWIResult.get("pause");
             try { pause = Integer.valueOf(pauseStr).intValue(); } catch (NumberFormatException numEx){}
-            if (pause <= 0) pause = 60000;
+            if (pause < 0) pause = 60000;
             else if (pause > 1800000) pause = 1800000;
         }        
         return pause;     
     }
     
     private void pause(long sleepTime) throws InterruptedException {        
+        if (sleepTime == 0) return;
         long sleepCounter = sleepTime / 1000;
         long sleepRest = sleepTime % 1000;
         while (!this.isAborted() && sleepCounter > 0) {
diff --git a/yacy.init b/yacy.init
index 44c2d3ad0..b856bac5f 100644
--- a/yacy.init
+++ b/yacy.init
@@ -649,6 +649,14 @@ indexDistribution.minChunkSize = 5
 indexDistribution.maxChunkSize = 1000
 indexDistribution.startChunkSize = 50
 
+# defines if the peer should reject incoming index transfer
+# request if a given limit is reached
+indexDistribution.dhtReceiptLimitEnabled = false
+
+# defines the word cache for DHT reaches this level
+# the peer reports itself as busy
+indexDistribution.dhtReceiptLimit = 1000
+
 # Distribution of Citation-Reference (CR-) files
 # The distribution is done in two steps:
 # first step to anonymize the records