Eliminate connect to self (hyperledger#3342)

* don't allow connect to self

Signed-off-by: Sally MacFarlane <sally.macfarlane@consensys.net>

CHANGELOG.md

@@ -7,6 +7,7 @@
 - Updated besu-native to version 0.4.3 [#3331](https://github.com/hyperledger/besu/pull/3331)
 
 ### Bug Fixes
+- Prevent node from peering to itself [#3342](https://github.com/hyperledger/besu/pull/3342)
 
 
 ## 22.1.0-RC3

ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/permissions/PeerPermissionsDenylist.java

@@ -14,6 +14,7 @@
  */
 package org.hyperledger.besu.ethereum.p2p.permissions;
 
+import org.hyperledger.besu.ethereum.p2p.peers.EnodeURLImpl;
 import org.hyperledger.besu.ethereum.p2p.peers.Peer;
 import org.hyperledger.besu.util.LimitedSet;
 import org.hyperledger.besu.util.LimitedSet.Mode;
@@ -54,7 +55,8 @@ public static PeerPermissionsDenylist create(final int maxSize) {
 
   @Override
   public boolean isPermitted(final Peer localNode, final Peer remotePeer, final Action action) {
-    return !blacklist.contains(remotePeer.getId());
+    return !EnodeURLImpl.sameListeningEndpoint(localNode.getEnodeURL(), remotePeer.getEnodeURL())
+        && !blacklist.contains(remotePeer.getId());
   }
 
   public void add(final Peer peer) {

ethereum/p2p/src/test/java/org/hyperledger/besu/ethereum/p2p/permissions/PeerPermissionsDenylistTest.java

@@ -125,6 +125,13 @@ public void trackedPeerIsNotPermitted() {
     checkPermissions(blacklist, peer, true);
   }
 
+  @Test
+  public void selfPeerIsNotPermitted() {
+    PeerPermissionsDenylist blacklist = PeerPermissionsDenylist.create();
+
+    checkPermissions(blacklist, localNode, false);
+  }
+
   @Test
   public void subscribeUpdate() {
     PeerPermissionsDenylist blacklist = PeerPermissionsDenylist.create();