feat(net): limit SR connections to fast forwarding nodes

framework/src/main/java/org/tron/core/net/service/relay/RelayService.java

@@ -71,6 +71,8 @@ public class RelayService {
 
   private int maxFastForwardNum = Args.getInstance().getMaxFastForwardNum();
 
+  private static final int MAX_PEER_COUNT_PER_ADDRESS = 2;
+
   public void init() {
     manager = ctx.getBean(Manager.class);
     witnessScheduleStore = ctx.getBean(WitnessScheduleStore.class);
@@ -139,6 +141,13 @@ public boolean checkHelloMessage(HelloMessage message, Channel channel) {
       return false;
     }
 
+    if (getPeerCountByAddress(msg.getAddress()) >= MAX_PEER_COUNT_PER_ADDRESS) {
+      logger.warn("HelloMessage from {}, the number of peers of {} exceeds 2.",
+          channel.getInetAddress(),
+          ByteArray.toHexString(msg.getAddress().toByteArray()));
+      return false;
+    }
+
     boolean flag;
     try {
       Sha256Hash hash = Sha256Hash.of(CommonParameter
@@ -164,6 +173,12 @@ public boolean checkHelloMessage(HelloMessage message, Channel channel) {
     }
   }
 
+  private long getPeerCountByAddress(ByteString address) {
+    return tronNetDelegate.getActivePeer().stream()
+        .filter(peer -> peer.getAddress() != null && peer.getAddress().equals(address))
+        .count();
+  }
+
   private boolean isActiveWitness() {
     return parameter.isWitness()
         && keySize > 0

framework/src/test/java/org/tron/core/net/services/RelayServiceTest.java

@@ -2,7 +2,10 @@
 
 import com.google.common.collect.Lists;
 import com.google.protobuf.ByteString;
+
+import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.net.InetSocketAddress;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
@@ -13,19 +16,29 @@
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
+import org.mockito.Mockito;
+import org.springframework.context.ApplicationContext;
 import org.tron.common.BaseTest;
 import org.tron.common.utils.ReflectUtils;
+import org.tron.core.ChainBaseManager;
 import org.tron.core.Constant;
 import org.tron.core.capsule.BlockCapsule;
 import org.tron.core.capsule.WitnessCapsule;
 import org.tron.core.config.args.Args;
 import org.tron.core.net.P2pEventHandlerImpl;
 import org.tron.core.net.message.adv.BlockMessage;
+import org.tron.core.net.message.handshake.HelloMessage;
 import org.tron.core.net.peer.Item;
 import org.tron.core.net.peer.PeerConnection;
+import org.tron.core.net.peer.PeerManager;
 import org.tron.core.net.service.relay.RelayService;
+import org.tron.p2p.connection.Channel;
+import org.tron.p2p.discover.Node;
+import org.tron.p2p.utils.NetUtil;
 import org.tron.protos.Protocol;
 
+import static org.mockito.Mockito.mock;
+
 public class RelayServiceTest extends BaseTest {
 
   @Resource
@@ -49,6 +62,7 @@ public void test() throws Exception {
     initWitness();
     testGetNextWitnesses();
     testBroadcast();
+    testCheckHelloMessage();
   }
 
   private void initWitness() {
@@ -119,4 +133,39 @@ private ByteString getFromHexString(String s) {
     return ByteString.copyFrom(Hex.decode(s));
   }
 
+  private void testCheckHelloMessage() {
+    ByteString address = getFromHexString("A04711BF7AFBDF44557DEFBDF4C4E7AA6138C6331F");
+    InetSocketAddress a1 = new InetSocketAddress("127.0.0.1", 10001);
+    Node node = new Node(NetUtil.getNodeId(), a1.getAddress().getHostAddress(),
+        null, a1.getPort());
+    HelloMessage helloMessage = new HelloMessage(node, System.currentTimeMillis(),
+        ChainBaseManager.getChainBaseManager());
+    helloMessage.setHelloMessage(helloMessage.getHelloMessage().toBuilder()
+        .setAddress(address).build());
+    Channel c1 = mock(Channel.class);
+    Mockito.when(c1.getInetSocketAddress()).thenReturn(a1);
+    Mockito.when(c1.getInetAddress()).thenReturn(a1.getAddress());
+    Channel c2 = mock(Channel.class);
+    Mockito.when(c2.getInetSocketAddress()).thenReturn(a1);
+    Mockito.when(c2.getInetAddress()).thenReturn(a1.getAddress());
+    Args.getInstance().fastForward = true;
+    ApplicationContext ctx = (ApplicationContext) ReflectUtils.getFieldObject(p2pEventHandler,
+        "ctx");
+    PeerConnection peer1 = PeerManager.add(ctx, c1);
+    assert peer1 != null;
+    peer1.setAddress(address);
+    PeerConnection peer2 = PeerManager.add(ctx, c2);
+    assert peer2 != null;
+    peer2.setAddress(address);
+    try {
+      Field field = service.getClass().getDeclaredField("witnessScheduleStore");
+      field.setAccessible(true);
+      field.set(service, chainBaseManager.getWitnessScheduleStore());
+      boolean res = service.checkHelloMessage(helloMessage, c1);
+      Assert.assertFalse(res);
+    } catch (Exception e) {
+
+    }
+  }
+
 }