Merge branch '8lecramm-anti-spam' into main

p2p/chain_sync.go

@@ -388,6 +388,12 @@ func (connection *Connection) process_object_response(response Objects, sent int
 
 			return nil
 		}
+
+		// too old TXs will be ignored for mining, but we should check incoming TX here to avoid high system load
+		if uint64(chain.Get_Height()) > tx.Height+blockchain.TX_VALIDITY_HEIGHT {
+			connection.logger.V(2).Error(err, "Incoming TX is too far in the past", "txid", tx.GetHash().String())
+			continue
+		}
 
 		if !chain.Mempool.Mempool_TX_Exist(tx.GetHash()) { // we still donot have it, so try to process it
 			if chain.Add_TX_To_Pool(&tx) == nil { // currently we are ignoring error