network_query.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "../stdafx.h"
#include "core/network_game_info.h"
#include "network_query.h"
#include "network_gamelist.h"
#include "../error.h"
 
#include "table/strings.h"
 
#include "../safeguards.h"
 
std::vector<std::unique_ptr<QueryNetworkGameSocketHandler>> QueryNetworkGameSocketHandler::queries = {};
 
NetworkRecvStatus QueryNetworkGameSocketHandler::CloseConnection(NetworkRecvStatus status)
{
  assert(status != NETWORK_RECV_STATUS_OKAY);
  assert(this->sock != INVALID_SOCKET);
 
  /* Connection is closed, but we never received a packet. Must be offline. */
  NetworkGameList *item = NetworkGameListAddItem(this->connection_string);
  if (item->refreshing) {
    item->status = NGLS_OFFLINE;
    item->refreshing = false;
 
    UpdateNetworkGameWindow();
  }
 
  return status;
}
 
bool QueryNetworkGameSocketHandler::CheckConnection()
{
  std::chrono::steady_clock::duration lag = std::chrono::steady_clock::now() - this->last_packet;
 
  /* If there was no response in 5 seconds, terminate the query. */
  if (lag > std::chrono::seconds(5)) {
    Debug(net, 0, "Timeout while waiting for response from {}", this->connection_string);
    this->CloseConnection(NETWORK_RECV_STATUS_CONNECTION_LOST);
    return false;
  }
 
  return true;
}
 
bool QueryNetworkGameSocketHandler::Receive()
{
  if (this->CanSendReceive()) {
    NetworkRecvStatus res = this->ReceivePackets();
    if (res != NETWORK_RECV_STATUS_OKAY) {
      this->CloseConnection(res);
      return false;
    }
  }
  return true;
}
 
void QueryNetworkGameSocketHandler::Send()
{
  this->SendPackets();
}
 
NetworkRecvStatus QueryNetworkGameSocketHandler::SendGameInfo()
{
  Debug(net, 9, "Query::SendGameInfo()");
 
  this->SendPacket(std::make_unique<Packet>(this, PACKET_CLIENT_GAME_INFO));
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus QueryNetworkGameSocketHandler::Receive_SERVER_FULL(Packet &)
{
  Debug(net, 9, "Query::Receive_SERVER_FULL()");
 
  NetworkGameList *item = NetworkGameListAddItem(this->connection_string);
  item->status = NGLS_FULL;
  item->refreshing = false;
 
  UpdateNetworkGameWindow();
 
  return NETWORK_RECV_STATUS_CLOSE_QUERY;
}
 
NetworkRecvStatus QueryNetworkGameSocketHandler::Receive_SERVER_BANNED(Packet &)
{
  Debug(net, 9, "Query::Receive_SERVER_BANNED()");
 
  NetworkGameList *item = NetworkGameListAddItem(this->connection_string);
  item->status = NGLS_BANNED;
  item->refreshing = false;
 
  UpdateNetworkGameWindow();
 
  return NETWORK_RECV_STATUS_CLOSE_QUERY;
}
 
NetworkRecvStatus QueryNetworkGameSocketHandler::Receive_SERVER_GAME_INFO(Packet &p)
{
  Debug(net, 9, "Query::Receive_SERVER_GAME_INFO()");
 
  NetworkGameList *item = NetworkGameListAddItem(this->connection_string);
 
  /* Clear any existing GRFConfig chain. */
  ClearGRFConfigList(&item->info.grfconfig);
  /* Retrieve the NetworkGameInfo from the packet. */
  DeserializeNetworkGameInfo(p, item->info);
  /* Check for compatability with the client. */
  CheckGameCompatibility(item->info);
  /* Ensure we consider the server online. */
  item->status = NGLS_ONLINE;
  item->refreshing = false;
 
  UpdateNetworkGameWindow();
 
  return NETWORK_RECV_STATUS_CLOSE_QUERY;
}
 
NetworkRecvStatus QueryNetworkGameSocketHandler::Receive_SERVER_ERROR(Packet &p)
{
  NetworkErrorCode error = (NetworkErrorCode)p.Recv_uint8();
 
  Debug(net, 9, "Query::Receive_SERVER_ERROR(): error={}", error);
 
  NetworkGameList *item = NetworkGameListAddItem(this->connection_string);
 
  if (error == NETWORK_ERROR_NOT_EXPECTED) {
    /* If we query a server that is 1.11.1 or older, we get an
     * NETWORK_ERROR_NOT_EXPECTED on requesting the game info. Show to the
     * user this server is too old to query.
     */
    item->status = NGLS_TOO_OLD;
  } else {
    item->status = NGLS_OFFLINE;
  }
  item->refreshing = false;
 
  UpdateNetworkGameWindow();
 
  return NETWORK_RECV_STATUS_CLOSE_QUERY;
}
 
/* static */ void QueryNetworkGameSocketHandler::SendReceive()
{
  for (auto it = QueryNetworkGameSocketHandler::queries.begin(); it != QueryNetworkGameSocketHandler::queries.end(); /* nothing */) {
    if (!(*it)->Receive()) {
      it = QueryNetworkGameSocketHandler::queries.erase(it);
    } else if (!(*it)->CheckConnection()) {
      it = QueryNetworkGameSocketHandler::queries.erase(it);
    } else {
      it++;
    }
  }
 
  for (auto &query : QueryNetworkGameSocketHandler::queries) {
    query->Send();
  }
}