From 8451610737e5577aff530d2c1567a17eaea566a5 Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Mon, 20 Dec 2010 19:37:38 +0000
Subject: [PATCH] Several connect-to-self checks

---
 .../org/klomp/snark/ConnectionAcceptor.java   |  5 ++++
 .../src/org/klomp/snark/I2PSnarkUtil.java     | 26 +++++++++++++------
 .../java/src/org/klomp/snark/Peer.java        |  4 +++
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/apps/i2psnark/java/src/org/klomp/snark/ConnectionAcceptor.java b/apps/i2psnark/java/src/org/klomp/snark/ConnectionAcceptor.java
index 52099d1d2..34fa5054e 100644
--- a/apps/i2psnark/java/src/org/klomp/snark/ConnectionAcceptor.java
+++ b/apps/i2psnark/java/src/org/klomp/snark/ConnectionAcceptor.java
@@ -137,6 +137,11 @@ public class ConnectionAcceptor implements Runnable
                     }
                 }
             } else {
+                if (socket.getPeerDestination().equals(_util.getMyDestination())) {
+                    _util.debug("Incoming connection from myself", Snark.ERROR);
+                    try { socket.close(); } catch (IOException ioe) {}
+                    continue;
+                }
                 Thread t = new I2PAppThread(new Handler(socket), "I2PSnark incoming connection");
                 t.start();
             }
diff --git a/apps/i2psnark/java/src/org/klomp/snark/I2PSnarkUtil.java b/apps/i2psnark/java/src/org/klomp/snark/I2PSnarkUtil.java
index e8ff0881f..c0c272ae7 100644
--- a/apps/i2psnark/java/src/org/klomp/snark/I2PSnarkUtil.java
+++ b/apps/i2psnark/java/src/org/klomp/snark/I2PSnarkUtil.java
@@ -227,6 +227,8 @@ public class I2PSnarkUtil {
         Destination addr = peer.getAddress();
         if (addr == null)
             throw new IOException("Null address");
+        if (addr.equals(getMyDestination()))
+            throw new IOException("Attempt to connect to myself");
         Hash dest = addr.calculateHash();
         if (_shitlist.contains(dest))
             throw new IOException("Not trying to contact " + dest.toBase64() + ", as they are shitlisted");
@@ -300,17 +302,25 @@ public class I2PSnarkUtil {
     }
     
     String getOurIPString() {
-        if (_manager == null)
-            return "unknown";
-        I2PSession sess = _manager.getSession();
-        if (sess != null) {
-            Destination dest = sess.getMyDestination();
-            if (dest != null)
-                return dest.toBase64();
-        }
+        Destination dest = getMyDestination();
+        if (dest != null)
+            return dest.toBase64();
         return "unknown";
     }
 
+    /**
+     *  @return dest or null
+     *  @since 0.8.4
+     */
+    Destination getMyDestination() {
+        if (_manager == null)
+            return null;
+        I2PSession sess = _manager.getSession();
+        if (sess != null)
+            return sess.getMyDestination();
+        return null;
+    }
+
     /** Base64 only - static (no naming service) */
     static Destination getDestinationFromBase64(String ip) {
         if (ip == null) return null;
diff --git a/apps/i2psnark/java/src/org/klomp/snark/Peer.java b/apps/i2psnark/java/src/org/klomp/snark/Peer.java
index a65e45887..f5d200fda 100644
--- a/apps/i2psnark/java/src/org/klomp/snark/Peer.java
+++ b/apps/i2psnark/java/src/org/klomp/snark/Peer.java
@@ -30,6 +30,7 @@ import java.util.Arrays;
 import java.util.List;
 
 import net.i2p.client.streaming.I2PSocket;
+import net.i2p.data.DataHelper;
 import net.i2p.util.Log;
 
 public class Peer implements Comparable
@@ -353,6 +354,9 @@ public class Peer implements Comparable
     if (_log.shouldLog(Log.DEBUG))
         _log.debug("Read the remote side's hash and peerID fully from " + toString());
 
+    if (DataHelper.eq(my_id, bs))
+        throw new IOException("Connected to myself");
+
     if (options != 0) {
         // send them something in runConnection() above
         if (_log.shouldLog(Log.DEBUG))