Merge pull request #8916

1924c17 protocol: drop peers sending duplicate txes (moneromooo-monero)

src/cryptonote_protocol/cryptonote_protocol_handler.inl

@@ -979,8 +979,18 @@ namespace cryptonote
   int t_cryptonote_protocol_handler<t_core>::handle_notify_new_transactions(int command, NOTIFY_NEW_TRANSACTIONS::request& arg, cryptonote_connection_context& context)
   {
     MLOG_P2P_MESSAGE("Received NOTIFY_NEW_TRANSACTIONS (" << arg.txs.size() << " txes)");
+    std::unordered_set<blobdata> seen;
     for (const auto &blob: arg.txs)
+    {
       MLOGIF_P2P_MESSAGE(cryptonote::transaction tx; crypto::hash hash; bool ret = cryptonote::parse_and_validate_tx_from_blob(blob, tx, hash);, ret, "Including transaction " << hash);
+      if (seen.find(blob) != seen.end())
+      {
+        LOG_PRINT_CCONTEXT_L1("Duplicate transaction in notification, dropping connection");
+        drop_connection(context, false, false);
+        return 1;
+      }
+      seen.insert(blob);
+    }
 
     if(context.m_state != cryptonote_connection_context::state_normal)
       return 1;