network_server.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 "../strings_func.h"
#include "../date_func.h"
#include "network_admin.h"
#include "network_server.h"
#include "network_udp.h"
#include "network_base.h"
#include "../console_func.h"
#include "../company_base.h"
#include "../command_func.h"
#include "../saveload/saveload.h"
#include "../saveload/saveload_filter.h"
#include "../station_base.h"
#include "../genworld.h"
#include "../company_func.h"
#include "../company_gui.h"
#include "../roadveh.h"
#include "../order_backup.h"
#include "../core/pool_func.hpp"
#include "../core/random_func.hpp"
#include "../rev.h"
#include <mutex>
#include <condition_variable>
 
#include "../safeguards.h"
 
 
/* This file handles all the server-commands */
 
DECLARE_POSTFIX_INCREMENT(ClientID)
static ClientID _network_client_id = CLIENT_ID_FIRST;
 
static_assert(MAX_CLIENT_SLOTS > MAX_CLIENTS);
static_assert(NetworkClientSocketPool::MAX_SIZE == MAX_CLIENT_SLOTS);
 
NetworkClientSocketPool _networkclientsocket_pool("NetworkClientSocket");
INSTANTIATE_POOL_METHODS(NetworkClientSocket)
 
template SocketList TCPListenHandler<ServerNetworkGameSocketHandler, PACKET_SERVER_FULL, PACKET_SERVER_BANNED>::sockets;
 
struct PacketWriter : SaveFilter {
  ServerNetworkGameSocketHandler *cs; 
  Packet *current;                    
  size_t total_size;                  
  Packet *packets;                    
  std::mutex mutex;                   
  std::condition_variable exit_sig;   
 
  PacketWriter(ServerNetworkGameSocketHandler *cs) : SaveFilter(nullptr), cs(cs), current(nullptr), total_size(0), packets(nullptr)
  {
  }
 
  ~PacketWriter()
  {
    std::unique_lock<std::mutex> lock(this->mutex);
 
    if (this->cs != nullptr) this->exit_sig.wait(lock);
 
    /* This must all wait until the Destroy function is called. */
 
    while (this->packets != nullptr) {
      Packet *p = this->packets->next;
      delete this->packets;
      this->packets = p;
    }
 
    delete this->current;
  }
 
  void Destroy()
  {
    std::unique_lock<std::mutex> lock(this->mutex);
 
    this->cs = nullptr;
 
    this->exit_sig.notify_all();
    lock.unlock();
 
    /* Make sure the saving is completely cancelled. Yes,
     * we need to handle the save finish as well as the
     * next connection might just be requesting a map. */
    WaitTillSaved();
    ProcessAsyncSaveFinish();
  }
 
  bool HasPackets()
  {
    return this->packets != nullptr;
  }
 
  Packet *PopPacket()
  {
    std::lock_guard<std::mutex> lock(this->mutex);
 
    Packet *p = this->packets;
    this->packets = p->next;
    p->next = nullptr;
 
    return p;
  }
 
  void AppendQueue()
  {
    if (this->current == nullptr) return;
 
    Packet **p = &this->packets;
    while (*p != nullptr) {
      p = &(*p)->next;
    }
    *p = this->current;
 
    this->current = nullptr;
  }
 
  void PrependQueue()
  {
    if (this->current == nullptr) return;
 
    this->current->next = this->packets;
    this->packets = this->current;
    this->current = nullptr;
  }
 
  void Write(byte *buf, size_t size) override
  {
    /* We want to abort the saving when the socket is closed. */
    if (this->cs == nullptr) SlError(STR_NETWORK_ERROR_LOSTCONNECTION);
 
    if (this->current == nullptr) this->current = new Packet(PACKET_SERVER_MAP_DATA);
 
    std::lock_guard<std::mutex> lock(this->mutex);
 
    byte *bufe = buf + size;
    while (buf != bufe) {
      size_t to_write = std::min<size_t>(SEND_MTU - this->current->size, bufe - buf);
      memcpy(this->current->buffer + this->current->size, buf, to_write);
      this->current->size += (PacketSize)to_write;
      buf += to_write;
 
      if (this->current->size == SEND_MTU) {
        this->AppendQueue();
        if (buf != bufe) this->current = new Packet(PACKET_SERVER_MAP_DATA);
      }
    }
 
    this->total_size += size;
  }
 
  void Finish() override
  {
    /* We want to abort the saving when the socket is closed. */
    if (this->cs == nullptr) SlError(STR_NETWORK_ERROR_LOSTCONNECTION);
 
    std::lock_guard<std::mutex> lock(this->mutex);
 
    /* Make sure the last packet is flushed. */
    this->AppendQueue();
 
    /* Add a packet stating that this is the end to the queue. */
    this->current = new Packet(PACKET_SERVER_MAP_DONE);
    this->AppendQueue();
 
    /* Fast-track the size to the client. */
    this->current = new Packet(PACKET_SERVER_MAP_SIZE);
    this->current->Send_uint32((uint32)this->total_size);
    this->PrependQueue();
  }
};
 
 
ServerNetworkGameSocketHandler::ServerNetworkGameSocketHandler(SOCKET s) : NetworkGameSocketHandler(s)
{
  this->status = STATUS_INACTIVE;
  this->client_id = _network_client_id++;
  this->receive_limit = _settings_client.network.bytes_per_frame_burst;
 
  /* The Socket and Info pools need to be the same in size. After all,
   * each Socket will be associated with at most one Info object. As
   * such if the Socket was allocated the Info object can as well. */
  static_assert(NetworkClientSocketPool::MAX_SIZE == NetworkClientInfoPool::MAX_SIZE);
}
 
ServerNetworkGameSocketHandler::~ServerNetworkGameSocketHandler()
{
  if (_redirect_console_to_client == this->client_id) _redirect_console_to_client = INVALID_CLIENT_ID;
  OrderBackup::ResetUser(this->client_id);
 
  if (this->savegame != nullptr) {
    this->savegame->Destroy();
    this->savegame = nullptr;
  }
}
 
Packet *ServerNetworkGameSocketHandler::ReceivePacket()
{
  /* Only allow receiving when we have some buffer free; this value
   * can go negative, but eventually it will become positive again. */
  if (this->receive_limit <= 0) return nullptr;
 
  /* We can receive a packet, so try that and if needed account for
   * the amount of received data. */
  Packet *p = this->NetworkTCPSocketHandler::ReceivePacket();
  if (p != nullptr) this->receive_limit -= p->size;
  return p;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::CloseConnection(NetworkRecvStatus status)
{
  assert(status != NETWORK_RECV_STATUS_OKAY);
  /*
   * Sending a message just before leaving the game calls cs->SendPackets.
   * This might invoke this function, which means that when we close the
   * connection after cs->SendPackets we will close an already closed
   * connection. This handles that case gracefully without having to make
   * that code any more complex or more aware of the validity of the socket.
   */
  if (this->sock == INVALID_SOCKET) return status;
 
  if (status != NETWORK_RECV_STATUS_CONN_LOST && status != NETWORK_RECV_STATUS_SERVER_ERROR && !this->HasClientQuit() && this->status >= STATUS_AUTHORIZED) {
    /* We did not receive a leave message from this client... */
    char client_name[NETWORK_CLIENT_NAME_LENGTH];
 
    this->GetClientName(client_name, lastof(client_name));
 
    NetworkTextMessage(NETWORK_ACTION_LEAVE, CC_DEFAULT, false, client_name, nullptr, STR_NETWORK_ERROR_CLIENT_CONNECTION_LOST);
 
    /* Inform other clients of this... strange leaving ;) */
    for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
      if (new_cs->status > STATUS_AUTHORIZED && this != new_cs) {
        new_cs->SendErrorQuit(this->client_id, NETWORK_ERROR_CONNECTION_LOST);
      }
    }
  }
 
  /* If we were transfering a map to this client, stop the savegame creation
   * process and queue the next client to receive the map. */
  if (this->status == STATUS_MAP) {
    /* Ensure the saving of the game is stopped too. */
    this->savegame->Destroy();
    this->savegame = nullptr;
 
    this->CheckNextClientToSendMap(this);
  }
 
  NetworkAdminClientError(this->client_id, NETWORK_ERROR_CONNECTION_LOST);
  DEBUG(net, 1, "Closed client connection %d", this->client_id);
 
  /* We just lost one client :( */
  if (this->status >= STATUS_AUTHORIZED) _network_game_info.clients_on--;
  extern byte _network_clients_connected;
  _network_clients_connected--;
 
  DeleteWindowById(WC_CLIENT_LIST_POPUP, this->client_id);
  SetWindowDirty(WC_CLIENT_LIST, 0);
 
  this->SendPackets(true);
 
  delete this->GetInfo();
  delete this;
 
  return status;
}
 
/* static */ bool ServerNetworkGameSocketHandler::AllowConnection()
{
  extern byte _network_clients_connected;
  bool accept = _network_clients_connected < MAX_CLIENTS && _network_game_info.clients_on < _settings_client.network.max_clients;
 
  /* We can't go over the MAX_CLIENTS limit here. However, the
   * pool must have place for all clients and ourself. */
  static_assert(NetworkClientSocketPool::MAX_SIZE == MAX_CLIENTS + 1);
  assert(!accept || ServerNetworkGameSocketHandler::CanAllocateItem());
  return accept;
}
 
/* static */ void ServerNetworkGameSocketHandler::Send()
{
  for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
    if (cs->writable) {
      if (cs->SendPackets() != SPS_CLOSED && cs->status == STATUS_MAP) {
        /* This client is in the middle of a map-send, call the function for that */
        cs->SendMap();
      }
    }
  }
}
 
static void NetworkHandleCommandQueue(NetworkClientSocket *cs);
 
/***********
 * Sending functions
 *   DEF_SERVER_SEND_COMMAND has parameter: NetworkClientSocket *cs
 ************/
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendClientInfo(NetworkClientInfo *ci)
{
  if (ci->client_id != INVALID_CLIENT_ID) {
    Packet *p = new Packet(PACKET_SERVER_CLIENT_INFO);
    p->Send_uint32(ci->client_id);
    p->Send_uint8 (ci->client_playas);
    p->Send_string(ci->client_name);
 
    this->SendPacket(p);
  }
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendCompanyInfo()
{
  /* Fetch the latest version of the stats */
  NetworkCompanyStats company_stats[MAX_COMPANIES];
  NetworkPopulateCompanyStats(company_stats);
 
  /* Make a list of all clients per company */
  char clients[MAX_COMPANIES][NETWORK_CLIENTS_LENGTH];
  memset(clients, 0, sizeof(clients));
 
  /* Add the local player (if not dedicated) */
  const NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(CLIENT_ID_SERVER);
  if (ci != nullptr && Company::IsValidID(ci->client_playas)) {
    strecpy(clients[ci->client_playas], ci->client_name, lastof(clients[ci->client_playas]));
  }
 
  for (NetworkClientSocket *csi : NetworkClientSocket::Iterate()) {
    char client_name[NETWORK_CLIENT_NAME_LENGTH];
 
    ((ServerNetworkGameSocketHandler*)csi)->GetClientName(client_name, lastof(client_name));
 
    ci = csi->GetInfo();
    if (ci != nullptr && Company::IsValidID(ci->client_playas)) {
      if (!StrEmpty(clients[ci->client_playas])) {
        strecat(clients[ci->client_playas], ", ", lastof(clients[ci->client_playas]));
      }
 
      strecat(clients[ci->client_playas], client_name, lastof(clients[ci->client_playas]));
    }
  }
 
  /* Now send the data */
 
  Packet *p;
 
  for (const Company *company : Company::Iterate()) {
    p = new Packet(PACKET_SERVER_COMPANY_INFO);
 
    p->Send_uint8 (NETWORK_COMPANY_INFO_VERSION);
    p->Send_bool  (true);
    this->SendCompanyInformation(p, company, &company_stats[company->index]);
 
    if (StrEmpty(clients[company->index])) {
      p->Send_string("<none>");
    } else {
      p->Send_string(clients[company->index]);
    }
 
    this->SendPacket(p);
  }
 
  p = new Packet(PACKET_SERVER_COMPANY_INFO);
 
  p->Send_uint8 (NETWORK_COMPANY_INFO_VERSION);
  p->Send_bool  (false);
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendError(NetworkErrorCode error, const char *reason)
{
  char str[100];
  Packet *p = new Packet(PACKET_SERVER_ERROR);
 
  p->Send_uint8(error);
  if (reason != nullptr) p->Send_string(reason);
  this->SendPacket(p);
 
  StringID strid = GetNetworkErrorMsg(error);
  GetString(str, strid, lastof(str));
 
  /* Only send when the current client was in game */
  if (this->status > STATUS_AUTHORIZED) {
    char client_name[NETWORK_CLIENT_NAME_LENGTH];
 
    this->GetClientName(client_name, lastof(client_name));
 
    DEBUG(net, 1, "'%s' made an error and has been disconnected. Reason: '%s'", client_name, str);
 
    if (error == NETWORK_ERROR_KICKED && reason != nullptr) {
      NetworkTextMessage(NETWORK_ACTION_KICKED, CC_DEFAULT, false, client_name, reason, strid);
    } else {
      NetworkTextMessage(NETWORK_ACTION_LEAVE, CC_DEFAULT, false, client_name, nullptr, strid);
    }
 
    for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
      if (new_cs->status >= STATUS_AUTHORIZED && new_cs != this) {
        /* Some errors we filter to a more general error. Clients don't have to know the real
         *  reason a joining failed. */
        if (error == NETWORK_ERROR_NOT_AUTHORIZED || error == NETWORK_ERROR_NOT_EXPECTED || error == NETWORK_ERROR_WRONG_REVISION) {
          error = NETWORK_ERROR_ILLEGAL_PACKET;
        }
        new_cs->SendErrorQuit(this->client_id, error);
      }
    }
 
    NetworkAdminClientError(this->client_id, error);
  } else {
    DEBUG(net, 1, "Client %d made an error and has been disconnected. Reason: '%s'", this->client_id, str);
  }
 
  /* The client made a mistake, so drop his connection now! */
  return this->CloseConnection(NETWORK_RECV_STATUS_SERVER_ERROR);
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendNewGRFCheck()
{
  Packet *p = new Packet(PACKET_SERVER_CHECK_NEWGRFS);
  const GRFConfig *c;
  uint grf_count = 0;
 
  for (c = _grfconfig; c != nullptr; c = c->next) {
    if (!HasBit(c->flags, GCF_STATIC)) grf_count++;
  }
 
  p->Send_uint8 (grf_count);
  for (c = _grfconfig; c != nullptr; c = c->next) {
    if (!HasBit(c->flags, GCF_STATIC)) this->SendGRFIdentifier(p, &c->ident);
  }
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendNeedGamePassword()
{
  /* Invalid packet when status is STATUS_AUTH_GAME or higher */
  if (this->status >= STATUS_AUTH_GAME) return this->CloseConnection(NETWORK_RECV_STATUS_MALFORMED_PACKET);
 
  this->status = STATUS_AUTH_GAME;
  /* Reset 'lag' counters */
  this->last_frame = this->last_frame_server = _frame_counter;
 
  Packet *p = new Packet(PACKET_SERVER_NEED_GAME_PASSWORD);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendNeedCompanyPassword()
{
  /* Invalid packet when status is STATUS_AUTH_COMPANY or higher */
  if (this->status >= STATUS_AUTH_COMPANY) return this->CloseConnection(NETWORK_RECV_STATUS_MALFORMED_PACKET);
 
  this->status = STATUS_AUTH_COMPANY;
  /* Reset 'lag' counters */
  this->last_frame = this->last_frame_server = _frame_counter;
 
  Packet *p = new Packet(PACKET_SERVER_NEED_COMPANY_PASSWORD);
  p->Send_uint32(_settings_game.game_creation.generation_seed);
  p->Send_string(_settings_client.network.network_id);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendWelcome()
{
  Packet *p;
 
  /* Invalid packet when status is AUTH or higher */
  if (this->status >= STATUS_AUTHORIZED) return this->CloseConnection(NETWORK_RECV_STATUS_MALFORMED_PACKET);
 
  this->status = STATUS_AUTHORIZED;
  /* Reset 'lag' counters */
  this->last_frame = this->last_frame_server = _frame_counter;
 
  _network_game_info.clients_on++;
 
  p = new Packet(PACKET_SERVER_WELCOME);
  p->Send_uint32(this->client_id);
  p->Send_uint32(_settings_game.game_creation.generation_seed);
  p->Send_string(_settings_client.network.network_id);
  this->SendPacket(p);
 
  /* Transmit info about all the active clients */
  for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
    if (new_cs != this && new_cs->status >= STATUS_AUTHORIZED) {
      this->SendClientInfo(new_cs->GetInfo());
    }
  }
  /* Also send the info of the server */
  return this->SendClientInfo(NetworkClientInfo::GetByClientID(CLIENT_ID_SERVER));
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendWait()
{
  int waiting = 1; // current player getting the map counts as 1
  Packet *p;
 
  /* Count how many clients are waiting in the queue, in front of you! */
  for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
    if (new_cs->status != STATUS_MAP_WAIT) continue;
    if (new_cs->GetInfo()->join_date < this->GetInfo()->join_date || (new_cs->GetInfo()->join_date == this->GetInfo()->join_date && new_cs->client_id < this->client_id)) waiting++;
  }
 
  p = new Packet(PACKET_SERVER_WAIT);
  p->Send_uint8(waiting);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
void ServerNetworkGameSocketHandler::CheckNextClientToSendMap(NetworkClientSocket *ignore_cs)
{
  /* Find the best candidate for joining, i.e. the first joiner. */
  NetworkClientSocket *best = nullptr;
  for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
    if (ignore_cs == new_cs) continue;
 
    if (new_cs->status == STATUS_MAP_WAIT) {
      if (best == nullptr || best->GetInfo()->join_date > new_cs->GetInfo()->join_date || (best->GetInfo()->join_date == new_cs->GetInfo()->join_date && best->client_id > new_cs->client_id)) {
        best = new_cs;
      }
    }
  }
 
  /* Is there someone else to join? */
  if (best != nullptr) {
    /* Let the first start joining. */
    best->status = STATUS_AUTHORIZED;
    best->SendMap();
 
    /* And update the rest. */
    for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
      if (new_cs->status == STATUS_MAP_WAIT) new_cs->SendWait();
    }
  }
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendMap()
{
  static uint sent_packets; // How many packets we did send successfully last time
 
  if (this->status < STATUS_AUTHORIZED) {
    /* Illegal call, return error and ignore the packet */
    return this->SendError(NETWORK_ERROR_NOT_AUTHORIZED);
  }
 
  if (this->status == STATUS_AUTHORIZED) {
    this->savegame = new PacketWriter(this);
 
    /* Now send the _frame_counter and how many packets are coming */
    Packet *p = new Packet(PACKET_SERVER_MAP_BEGIN);
    p->Send_uint32(_frame_counter);
    this->SendPacket(p);
 
    NetworkSyncCommandQueue(this);
    this->status = STATUS_MAP;
    /* Mark the start of download */
    this->last_frame = _frame_counter;
    this->last_frame_server = _frame_counter;
 
    sent_packets = 4; // We start with trying 4 packets
 
    /* Make a dump of the current game */
    if (SaveWithFilter(this->savegame, true) != SL_OK) usererror("network savedump failed");
  }
 
  if (this->status == STATUS_MAP) {
    bool last_packet = false;
    bool has_packets = false;
 
    for (uint i = 0; (has_packets = this->savegame->HasPackets()) && i < sent_packets; i++) {
      Packet *p = this->savegame->PopPacket();
      last_packet = p->buffer[2] == PACKET_SERVER_MAP_DONE;
 
      this->SendPacket(p);
 
      if (last_packet) {
        /* There is no more data, so break the for */
        break;
      }
    }
 
    if (last_packet) {
      /* Done reading, make sure saving is done as well */
      this->savegame->Destroy();
      this->savegame = nullptr;
 
      /* Set the status to DONE_MAP, no we will wait for the client
       *  to send it is ready (maybe that happens like never ;)) */
      this->status = STATUS_DONE_MAP;
 
      this->CheckNextClientToSendMap();
    }
 
    switch (this->SendPackets()) {
      case SPS_CLOSED:
        return NETWORK_RECV_STATUS_CONN_LOST;
 
      case SPS_ALL_SENT:
        /* All are sent, increase the sent_packets */
        if (has_packets) sent_packets *= 2;
        break;
 
      case SPS_PARTLY_SENT:
        /* Only a part is sent; leave the transmission state. */
        break;
 
      case SPS_NONE_SENT:
        /* Not everything is sent, decrease the sent_packets */
        if (sent_packets > 1) sent_packets /= 2;
        break;
    }
  }
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendJoin(ClientID client_id)
{
  Packet *p = new Packet(PACKET_SERVER_JOIN);
 
  p->Send_uint32(client_id);
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendFrame()
{
  Packet *p = new Packet(PACKET_SERVER_FRAME);
  p->Send_uint32(_frame_counter);
  p->Send_uint32(_frame_counter_max);
#ifdef ENABLE_NETWORK_SYNC_EVERY_FRAME
  p->Send_uint32(_sync_seed_1);
#ifdef NETWORK_SEND_DOUBLE_SEED
  p->Send_uint32(_sync_seed_2);
#endif
#endif
 
  /* If token equals 0, we need to make a new token and send that. */
  if (this->last_token == 0) {
    this->last_token = InteractiveRandomRange(UINT8_MAX - 1) + 1;
    p->Send_uint8(this->last_token);
  }
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendSync()
{
  Packet *p = new Packet(PACKET_SERVER_SYNC);
  p->Send_uint32(_frame_counter);
  p->Send_uint32(_sync_seed_1);
 
#ifdef NETWORK_SEND_DOUBLE_SEED
  p->Send_uint32(_sync_seed_2);
#endif
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendCommand(const CommandPacket *cp)
{
  Packet *p = new Packet(PACKET_SERVER_COMMAND);
 
  this->NetworkGameSocketHandler::SendCommand(p, cp);
  p->Send_uint32(cp->frame);
  p->Send_bool  (cp->my_cmd);
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendChat(NetworkAction action, ClientID client_id, bool self_send, const char *msg, int64 data)
{
  if (this->status < STATUS_PRE_ACTIVE) return NETWORK_RECV_STATUS_OKAY;
 
  Packet *p = new Packet(PACKET_SERVER_CHAT);
 
  p->Send_uint8 (action);
  p->Send_uint32(client_id);
  p->Send_bool  (self_send);
  p->Send_string(msg);
  p->Send_uint64(data);
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendErrorQuit(ClientID client_id, NetworkErrorCode errorno)
{
  Packet *p = new Packet(PACKET_SERVER_ERROR_QUIT);
 
  p->Send_uint32(client_id);
  p->Send_uint8 (errorno);
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendQuit(ClientID client_id)
{
  Packet *p = new Packet(PACKET_SERVER_QUIT);
 
  p->Send_uint32(client_id);
 
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendShutdown()
{
  Packet *p = new Packet(PACKET_SERVER_SHUTDOWN);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendNewGame()
{
  Packet *p = new Packet(PACKET_SERVER_NEWGAME);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendRConResult(uint16 colour, const char *command)
{
  Packet *p = new Packet(PACKET_SERVER_RCON);
 
  p->Send_uint16(colour);
  p->Send_string(command);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendMove(ClientID client_id, CompanyID company_id)
{
  Packet *p = new Packet(PACKET_SERVER_MOVE);
 
  p->Send_uint32(client_id);
  p->Send_uint8(company_id);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendCompanyUpdate()
{
  Packet *p = new Packet(PACKET_SERVER_COMPANY_UPDATE);
 
  p->Send_uint16(_network_company_passworded);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::SendConfigUpdate()
{
  Packet *p = new Packet(PACKET_SERVER_CONFIG_UPDATE);
 
  p->Send_uint8(_settings_client.network.max_companies);
  p->Send_uint8(_settings_client.network.max_spectators);
  this->SendPacket(p);
  return NETWORK_RECV_STATUS_OKAY;
}
 
/***********
 * Receiving functions
 *   DEF_SERVER_RECEIVE_COMMAND has parameter: NetworkClientSocket *cs, Packet *p
 ************/
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_COMPANY_INFO(Packet *p)
{
  return this->SendCompanyInfo();
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_NEWGRFS_CHECKED(Packet *p)
{
  if (this->status != STATUS_NEWGRFS_CHECK) {
    /* Illegal call, return error and ignore the packet */
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
  NetworkClientInfo *ci = this->GetInfo();
 
  /* We now want a password from the client else we do not allow him in! */
  if (!StrEmpty(_settings_client.network.server_password)) {
    return this->SendNeedGamePassword();
  }
 
  if (Company::IsValidID(ci->client_playas) && !StrEmpty(_network_company_states[ci->client_playas].password)) {
    return this->SendNeedCompanyPassword();
  }
 
  return this->SendWelcome();
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_JOIN(Packet *p)
{
  if (this->status != STATUS_INACTIVE) {
    /* Illegal call, return error and ignore the packet */
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
  char name[NETWORK_CLIENT_NAME_LENGTH];
  CompanyID playas;
  NetworkLanguage client_lang;
  char client_revision[NETWORK_REVISION_LENGTH];
 
  p->Recv_string(client_revision, sizeof(client_revision));
  uint32 newgrf_version = p->Recv_uint32();
 
  /* Check if the client has revision control enabled */
  if (!IsNetworkCompatibleVersion(client_revision) || _openttd_newgrf_version != newgrf_version) {
    /* Different revisions!! */
    return this->SendError(NETWORK_ERROR_WRONG_REVISION);
  }
 
  p->Recv_string(name, sizeof(name));
  playas = (Owner)p->Recv_uint8();
  client_lang = (NetworkLanguage)p->Recv_uint8();
 
  if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CONN_LOST;
 
  /* join another company does not affect these values */
  switch (playas) {
    case COMPANY_NEW_COMPANY: // New company
      if (Company::GetNumItems() >= _settings_client.network.max_companies) {
        return this->SendError(NETWORK_ERROR_FULL);
      }
      break;
    case COMPANY_SPECTATOR: // Spectator
      if (NetworkSpectatorCount() >= _settings_client.network.max_spectators) {
        return this->SendError(NETWORK_ERROR_FULL);
      }
      break;
    default: // Join another company (companies 1-8 (index 0-7))
      if (!Company::IsValidHumanID(playas)) {
        return this->SendError(NETWORK_ERROR_COMPANY_MISMATCH);
      }
      break;
  }
 
  /* We need a valid name.. make it Player */
  if (StrEmpty(name)) strecpy(name, "Player", lastof(name));
 
  if (!NetworkFindName(name, lastof(name))) { // Change name if duplicate
    /* We could not create a name for this client */
    return this->SendError(NETWORK_ERROR_NAME_IN_USE);
  }
 
  assert(NetworkClientInfo::CanAllocateItem());
  NetworkClientInfo *ci = new NetworkClientInfo(this->client_id);
  this->SetInfo(ci);
  ci->join_date = _date;
  strecpy(ci->client_name, name, lastof(ci->client_name));
  ci->client_playas = playas;
  ci->client_lang = client_lang;
  DEBUG(desync, 1, "client: %08x; %02x; %02x; %02x", _date, _date_fract, (int)ci->client_playas, (int)ci->index);
 
  /* Make sure companies to which people try to join are not autocleaned */
  if (Company::IsValidID(playas)) _network_company_states[playas].months_empty = 0;
 
  this->status = STATUS_NEWGRFS_CHECK;
 
  if (_grfconfig == nullptr) {
    /* Behave as if we received PACKET_CLIENT_NEWGRFS_CHECKED */
    return this->Receive_CLIENT_NEWGRFS_CHECKED(nullptr);
  }
 
  return this->SendNewGRFCheck();
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_GAME_PASSWORD(Packet *p)
{
  if (this->status != STATUS_AUTH_GAME) {
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
  char password[NETWORK_PASSWORD_LENGTH];
  p->Recv_string(password, sizeof(password));
 
  /* Check game password. Allow joining if we cleared the password meanwhile */
  if (!StrEmpty(_settings_client.network.server_password) &&
      strcmp(password, _settings_client.network.server_password) != 0) {
    /* Password is invalid */
    return this->SendError(NETWORK_ERROR_WRONG_PASSWORD);
  }
 
  const NetworkClientInfo *ci = this->GetInfo();
  if (Company::IsValidID(ci->client_playas) && !StrEmpty(_network_company_states[ci->client_playas].password)) {
    return this->SendNeedCompanyPassword();
  }
 
  /* Valid password, allow user */
  return this->SendWelcome();
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_COMPANY_PASSWORD(Packet *p)
{
  if (this->status != STATUS_AUTH_COMPANY) {
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
  char password[NETWORK_PASSWORD_LENGTH];
  p->Recv_string(password, sizeof(password));
 
  /* Check company password. Allow joining if we cleared the password meanwhile.
   * Also, check the company is still valid - client could be moved to spectators
   * in the middle of the authorization process */
  CompanyID playas = this->GetInfo()->client_playas;
  if (Company::IsValidID(playas) && !StrEmpty(_network_company_states[playas].password) &&
      strcmp(password, _network_company_states[playas].password) != 0) {
    /* Password is invalid */
    return this->SendError(NETWORK_ERROR_WRONG_PASSWORD);
  }
 
  return this->SendWelcome();
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_GETMAP(Packet *p)
{
  /* The client was never joined.. so this is impossible, right?
   *  Ignore the packet, give the client a warning, and close his connection */
  if (this->status < STATUS_AUTHORIZED || this->HasClientQuit()) {
    return this->SendError(NETWORK_ERROR_NOT_AUTHORIZED);
  }
 
  /* Check if someone else is receiving the map */
  for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
    if (new_cs->status == STATUS_MAP) {
      /* Tell the new client to wait */
      this->status = STATUS_MAP_WAIT;
      return this->SendWait();
    }
  }
 
  /* We receive a request to upload the map.. give it to the client! */
  return this->SendMap();
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_MAP_OK(Packet *p)
{
  /* Client has the map, now start syncing */
  if (this->status == STATUS_DONE_MAP && !this->HasClientQuit()) {
    char client_name[NETWORK_CLIENT_NAME_LENGTH];
 
    this->GetClientName(client_name, lastof(client_name));
 
    NetworkTextMessage(NETWORK_ACTION_JOIN, CC_DEFAULT, false, client_name, nullptr, this->client_id);
 
    /* Mark the client as pre-active, and wait for an ACK
     *  so we know he is done loading and in sync with us */
    this->status = STATUS_PRE_ACTIVE;
    NetworkHandleCommandQueue(this);
    this->SendFrame();
    this->SendSync();
 
    /* This is the frame the client receives
     *  we need it later on to make sure the client is not too slow */
    this->last_frame = _frame_counter;
    this->last_frame_server = _frame_counter;
 
    for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
      if (new_cs->status >= STATUS_AUTHORIZED) {
        new_cs->SendClientInfo(this->GetInfo());
        new_cs->SendJoin(this->client_id);
      }
    }
 
    NetworkAdminClientInfo(this, true);
 
    /* also update the new client with our max values */
    this->SendConfigUpdate();
 
    /* quickly update the syncing client with company details */
    return this->SendCompanyUpdate();
  }
 
  /* Wrong status for this packet, give a warning to client, and close connection */
  return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_COMMAND(Packet *p)
{
  /* The client was never joined.. so this is impossible, right?
   *  Ignore the packet, give the client a warning, and close his connection */
  if (this->status < STATUS_DONE_MAP || this->HasClientQuit()) {
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
  if (this->incoming_queue.Count() >= _settings_client.network.max_commands_in_queue) {
    return this->SendError(NETWORK_ERROR_TOO_MANY_COMMANDS);
  }
 
  CommandPacket cp;
  const char *err = this->ReceiveCommand(p, &cp);
 
  if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CONN_LOST;
 
  NetworkClientInfo *ci = this->GetInfo();
 
  if (err != nullptr) {
    IConsolePrintF(CC_ERROR, "WARNING: %s from client %d (IP: %s).", err, ci->client_id, this->GetClientIP());
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
 
  if ((GetCommandFlags(cp.cmd) & CMD_SERVER) && ci->client_id != CLIENT_ID_SERVER) {
    IConsolePrintF(CC_ERROR, "WARNING: server only command %u from client %u (IP: %s), kicking...", cp.cmd & CMD_ID_MASK, ci->client_id, this->GetClientIP());
    return this->SendError(NETWORK_ERROR_KICKED);
  }
 
  if ((GetCommandFlags(cp.cmd) & CMD_SPECTATOR) == 0 && !Company::IsValidID(cp.company) && ci->client_id != CLIENT_ID_SERVER) {
    IConsolePrintF(CC_ERROR, "WARNING: spectator (client: %u, IP: %s) issued non-spectator command %u, kicking...", ci->client_id, this->GetClientIP(), cp.cmd & CMD_ID_MASK);
    return this->SendError(NETWORK_ERROR_KICKED);
  }
 
  if (!(cp.cmd == CMD_COMPANY_CTRL && cp.p1 == 0 && ci->client_playas == COMPANY_NEW_COMPANY) && ci->client_playas != cp.company) {
    IConsolePrintF(CC_ERROR, "WARNING: client %d (IP: %s) tried to execute a command as company %d, kicking...",
                   ci->client_playas + 1, this->GetClientIP(), cp.company + 1);
    return this->SendError(NETWORK_ERROR_COMPANY_MISMATCH);
  }
 
  if (cp.cmd == CMD_COMPANY_CTRL) {
    if (cp.p1 != 0 || cp.company != COMPANY_SPECTATOR) {
      return this->SendError(NETWORK_ERROR_CHEATER);
    }
 
    /* Check if we are full - else it's possible for spectators to send a CMD_COMPANY_CTRL and the company is created regardless of max_companies! */
    if (Company::GetNumItems() >= _settings_client.network.max_companies) {
      NetworkServerSendChat(NETWORK_ACTION_SERVER_MESSAGE, DESTTYPE_CLIENT, ci->client_id, "cannot create new company, server full", CLIENT_ID_SERVER);
      return NETWORK_RECV_STATUS_OKAY;
    }
  }
 
  if (GetCommandFlags(cp.cmd) & CMD_CLIENT_ID) cp.p2 = this->client_id;
 
  this->incoming_queue.Append(&cp);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ERROR(Packet *p)
{
  /* This packets means a client noticed an error and is reporting this
   *  to us. Display the error and report it to the other clients */
  char str[100];
  char client_name[NETWORK_CLIENT_NAME_LENGTH];
  NetworkErrorCode errorno = (NetworkErrorCode)p->Recv_uint8();
 
  /* The client was never joined.. thank the client for the packet, but ignore it */
  if (this->status < STATUS_DONE_MAP || this->HasClientQuit()) {
    return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
  }
 
  this->GetClientName(client_name, lastof(client_name));
 
  StringID strid = GetNetworkErrorMsg(errorno);
  GetString(str, strid, lastof(str));
 
  DEBUG(net, 2, "'%s' reported an error and is closing its connection (%s)", client_name, str);
 
  NetworkTextMessage(NETWORK_ACTION_LEAVE, CC_DEFAULT, false, client_name, nullptr, strid);
 
  for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
    if (new_cs->status >= STATUS_AUTHORIZED) {
      new_cs->SendErrorQuit(this->client_id, errorno);
    }
  }
 
  NetworkAdminClientError(this->client_id, errorno);
 
  return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_QUIT(Packet *p)
{
  /* The client wants to leave. Display this and report it to the other
   *  clients. */
  char client_name[NETWORK_CLIENT_NAME_LENGTH];
 
  /* The client was never joined.. thank the client for the packet, but ignore it */
  if (this->status < STATUS_DONE_MAP || this->HasClientQuit()) {
    return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
  }
 
  this->GetClientName(client_name, lastof(client_name));
 
  NetworkTextMessage(NETWORK_ACTION_LEAVE, CC_DEFAULT, false, client_name, nullptr, STR_NETWORK_MESSAGE_CLIENT_LEAVING);
 
  for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
    if (new_cs->status >= STATUS_AUTHORIZED && new_cs != this) {
      new_cs->SendQuit(this->client_id);
    }
  }
 
  NetworkAdminClientQuit(this->client_id);
 
  return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ACK(Packet *p)
{
  if (this->status < STATUS_AUTHORIZED) {
    /* Illegal call, return error and ignore the packet */
    return this->SendError(NETWORK_ERROR_NOT_AUTHORIZED);
  }
 
  uint32 frame = p->Recv_uint32();
 
  /* The client is trying to catch up with the server */
  if (this->status == STATUS_PRE_ACTIVE) {
    /* The client is not yet caught up? */
    if (frame + DAY_TICKS < _frame_counter) return NETWORK_RECV_STATUS_OKAY;
 
    /* Now he is! Unpause the game */
    this->status = STATUS_ACTIVE;
    this->last_token_frame = _frame_counter;
 
    /* Execute script for, e.g. MOTD */
    IConsoleCmdExec("exec scripts/on_server_connect.scr 0");
  }
 
  /* Get, and validate the token. */
  uint8 token = p->Recv_uint8();
  if (token == this->last_token) {
    /* We differentiate between last_token_frame and last_frame so the lag
     * test uses the actual lag of the client instead of the lag for getting
     * the token back and forth; after all, the token is only sent every
     * time we receive a PACKET_CLIENT_ACK, after which we will send a new
     * token to the client. If the lag would be one day, then we would not
     * be sending the new token soon enough for the new daily scheduled
     * PACKET_CLIENT_ACK. This would then register the lag of the client as
     * two days, even when it's only a single day. */
    this->last_token_frame = _frame_counter;
    /* Request a new token. */
    this->last_token = 0;
  }
 
  /* The client received the frame, make note of it */
  this->last_frame = frame;
  /* With those 2 values we can calculate the lag realtime */
  this->last_frame_server = _frame_counter;
  return NETWORK_RECV_STATUS_OKAY;
}
 
 
void NetworkServerSendChat(NetworkAction action, DestType desttype, int dest, const char *msg, ClientID from_id, int64 data, bool from_admin)
{
  const NetworkClientInfo *ci, *ci_own, *ci_to;
 
  switch (desttype) {
    case DESTTYPE_CLIENT:
      /* Are we sending to the server? */
      if ((ClientID)dest == CLIENT_ID_SERVER) {
        ci = NetworkClientInfo::GetByClientID(from_id);
        /* Display the text locally, and that is it */
        if (ci != nullptr) {
          NetworkTextMessage(action, GetDrawStringCompanyColour(ci->client_playas), false, ci->client_name, msg, data);
 
          if (_settings_client.network.server_admin_chat) {
            NetworkAdminChat(action, desttype, from_id, msg, data, from_admin);
          }
        }
      } else {
        /* Else find the client to send the message to */
        for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
          if (cs->client_id == (ClientID)dest) {
            cs->SendChat(action, from_id, false, msg, data);
            break;
          }
        }
      }
 
      /* Display the message locally (so you know you have sent it) */
      if (from_id != (ClientID)dest) {
        if (from_id == CLIENT_ID_SERVER) {
          ci = NetworkClientInfo::GetByClientID(from_id);
          ci_to = NetworkClientInfo::GetByClientID((ClientID)dest);
          if (ci != nullptr && ci_to != nullptr) {
            NetworkTextMessage(action, GetDrawStringCompanyColour(ci->client_playas), true, ci_to->client_name, msg, data);
          }
        } else {
          for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
            if (cs->client_id == from_id) {
              cs->SendChat(action, (ClientID)dest, true, msg, data);
              break;
            }
          }
        }
      }
      break;
    case DESTTYPE_TEAM: {
      /* If this is false, the message is already displayed on the client who sent it. */
      bool show_local = true;
      /* Find all clients that belong to this company */
      ci_to = nullptr;
      for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
        ci = cs->GetInfo();
        if (ci != nullptr && ci->client_playas == (CompanyID)dest) {
          cs->SendChat(action, from_id, false, msg, data);
          if (cs->client_id == from_id) show_local = false;
          ci_to = ci; // Remember a client that is in the company for company-name
        }
      }
 
      /* if the server can read it, let the admin network read it, too. */
      if (_local_company == (CompanyID)dest && _settings_client.network.server_admin_chat) {
        NetworkAdminChat(action, desttype, from_id, msg, data, from_admin);
      }
 
      ci = NetworkClientInfo::GetByClientID(from_id);
      ci_own = NetworkClientInfo::GetByClientID(CLIENT_ID_SERVER);
      if (ci != nullptr && ci_own != nullptr && ci_own->client_playas == dest) {
        NetworkTextMessage(action, GetDrawStringCompanyColour(ci->client_playas), false, ci->client_name, msg, data);
        if (from_id == CLIENT_ID_SERVER) show_local = false;
        ci_to = ci_own;
      }
 
      /* There is no such client */
      if (ci_to == nullptr) break;
 
      /* Display the message locally (so you know you have sent it) */
      if (ci != nullptr && show_local) {
        if (from_id == CLIENT_ID_SERVER) {
          char name[NETWORK_NAME_LENGTH];
          StringID str = Company::IsValidID(ci_to->client_playas) ? STR_COMPANY_NAME : STR_NETWORK_SPECTATORS;
          SetDParam(0, ci_to->client_playas);
          GetString(name, str, lastof(name));
          NetworkTextMessage(action, GetDrawStringCompanyColour(ci_own->client_playas), true, name, msg, data);
        } else {
          for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
            if (cs->client_id == from_id) {
              cs->SendChat(action, ci_to->client_id, true, msg, data);
            }
          }
        }
      }
      break;
    }
    default:
      DEBUG(net, 0, "[server] received unknown chat destination type %d. Doing broadcast instead", desttype);
      FALLTHROUGH;
 
    case DESTTYPE_BROADCAST:
      for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
        cs->SendChat(action, from_id, false, msg, data);
      }
 
      NetworkAdminChat(action, desttype, from_id, msg, data, from_admin);
 
      ci = NetworkClientInfo::GetByClientID(from_id);
      if (ci != nullptr) {
        NetworkTextMessage(action, GetDrawStringCompanyColour(ci->client_playas), false, ci->client_name, msg, data);
      }
      break;
  }
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_CHAT(Packet *p)
{
  if (this->status < STATUS_PRE_ACTIVE) {
    /* Illegal call, return error and ignore the packet */
    return this->SendError(NETWORK_ERROR_NOT_AUTHORIZED);
  }
 
  NetworkAction action = (NetworkAction)p->Recv_uint8();
  DestType desttype = (DestType)p->Recv_uint8();
  int dest = p->Recv_uint32();
  char msg[NETWORK_CHAT_LENGTH];
 
  p->Recv_string(msg, NETWORK_CHAT_LENGTH);
  int64 data = p->Recv_uint64();
 
  NetworkClientInfo *ci = this->GetInfo();
  switch (action) {
    case NETWORK_ACTION_CHAT:
    case NETWORK_ACTION_CHAT_CLIENT:
    case NETWORK_ACTION_CHAT_COMPANY:
      NetworkServerSendChat(action, desttype, dest, msg, this->client_id, data);
      break;
    default:
      IConsolePrintF(CC_ERROR, "WARNING: invalid chat action from client %d (IP: %s).", ci->client_id, this->GetClientIP());
      return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_SET_PASSWORD(Packet *p)
{
  if (this->status != STATUS_ACTIVE) {
    /* Illegal call, return error and ignore the packet */
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
  char password[NETWORK_PASSWORD_LENGTH];
  const NetworkClientInfo *ci;
 
  p->Recv_string(password, sizeof(password));
  ci = this->GetInfo();
 
  NetworkServerSetCompanyPassword(ci->client_playas, password);
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_SET_NAME(Packet *p)
{
  if (this->status != STATUS_ACTIVE) {
    /* Illegal call, return error and ignore the packet */
    return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
  }
 
  char client_name[NETWORK_CLIENT_NAME_LENGTH];
  NetworkClientInfo *ci;
 
  p->Recv_string(client_name, sizeof(client_name));
  ci = this->GetInfo();
 
  if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CONN_LOST;
 
  if (ci != nullptr) {
    /* Display change */
    if (NetworkFindName(client_name, lastof(client_name))) {
      NetworkTextMessage(NETWORK_ACTION_NAME_CHANGE, CC_DEFAULT, false, ci->client_name, client_name);
      strecpy(ci->client_name, client_name, lastof(ci->client_name));
      NetworkUpdateClientInfo(ci->client_id);
    }
  }
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_RCON(Packet *p)
{
  if (this->status != STATUS_ACTIVE) return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
 
  char pass[NETWORK_PASSWORD_LENGTH];
  char command[NETWORK_RCONCOMMAND_LENGTH];
 
  if (StrEmpty(_settings_client.network.rcon_password)) return NETWORK_RECV_STATUS_OKAY;
 
  p->Recv_string(pass, sizeof(pass));
  p->Recv_string(command, sizeof(command));
 
  if (strcmp(pass, _settings_client.network.rcon_password) != 0) {
    DEBUG(net, 0, "[rcon] wrong password from client-id %d", this->client_id);
    return NETWORK_RECV_STATUS_OKAY;
  }
 
  DEBUG(net, 0, "[rcon] client-id %d executed: '%s'", this->client_id, command);
 
  _redirect_console_to_client = this->client_id;
  IConsoleCmdExec(command);
  _redirect_console_to_client = INVALID_CLIENT_ID;
  return NETWORK_RECV_STATUS_OKAY;
}
 
NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_MOVE(Packet *p)
{
  if (this->status != STATUS_ACTIVE) return this->SendError(NETWORK_ERROR_NOT_EXPECTED);
 
  CompanyID company_id = (Owner)p->Recv_uint8();
 
  /* Check if the company is valid, we don't allow moving to AI companies */
  if (company_id != COMPANY_SPECTATOR && !Company::IsValidHumanID(company_id)) return NETWORK_RECV_STATUS_OKAY;
 
  /* Check if we require a password for this company */
  if (company_id != COMPANY_SPECTATOR && !StrEmpty(_network_company_states[company_id].password)) {
    /* we need a password from the client - should be in this packet */
    char password[NETWORK_PASSWORD_LENGTH];
    p->Recv_string(password, sizeof(password));
 
    /* Incorrect password sent, return! */
    if (strcmp(password, _network_company_states[company_id].password) != 0) {
      DEBUG(net, 2, "[move] wrong password from client-id #%d for company #%d", this->client_id, company_id + 1);
      return NETWORK_RECV_STATUS_OKAY;
    }
  }
 
  /* if we get here we can move the client */
  NetworkServerDoMove(this->client_id, company_id);
  return NETWORK_RECV_STATUS_OKAY;
}
 
void NetworkSocketHandler::SendCompanyInformation(Packet *p, const Company *c, const NetworkCompanyStats *stats, uint max_len)
{
  /* Grab the company name */
  char company_name[NETWORK_COMPANY_NAME_LENGTH];
  SetDParam(0, c->index);
 
  assert(max_len <= lengthof(company_name));
  GetString(company_name, STR_COMPANY_NAME, company_name + max_len - 1);
 
  /* Get the income */
  Money income = 0;
  if (_cur_year - 1 == c->inaugurated_year) {
    /* The company is here just 1 year, so display [2], else display[1] */
    for (uint i = 0; i < lengthof(c->yearly_expenses[2]); i++) {
      income -= c->yearly_expenses[2][i];
    }
  } else {
    for (uint i = 0; i < lengthof(c->yearly_expenses[1]); i++) {
      income -= c->yearly_expenses[1][i];
    }
  }
 
  /* Send the information */
  p->Send_uint8 (c->index);
  p->Send_string(company_name);
  p->Send_uint32(c->inaugurated_year);
  p->Send_uint64(c->old_economy[0].company_value);
  p->Send_uint64(c->money);
  p->Send_uint64(income);
  p->Send_uint16(c->old_economy[0].performance_history);
 
  /* Send 1 if there is a password for the company else send 0 */
  p->Send_bool  (!StrEmpty(_network_company_states[c->index].password));
 
  for (uint i = 0; i < NETWORK_VEH_END; i++) {
    p->Send_uint16(stats->num_vehicle[i]);
  }
 
  for (uint i = 0; i < NETWORK_VEH_END; i++) {
    p->Send_uint16(stats->num_station[i]);
  }
 
  p->Send_bool(c->is_ai);
}
 
void NetworkPopulateCompanyStats(NetworkCompanyStats *stats)
{
  memset(stats, 0, sizeof(*stats) * MAX_COMPANIES);
 
  /* Go through all vehicles and count the type of vehicles */
  for (const Vehicle *v : Vehicle::Iterate()) {
    if (!Company::IsValidID(v->owner) || !v->IsPrimaryVehicle()) continue;
    byte type = 0;
    switch (v->type) {
      case VEH_TRAIN: type = NETWORK_VEH_TRAIN; break;
      case VEH_ROAD: type = RoadVehicle::From(v)->IsBus() ? NETWORK_VEH_BUS : NETWORK_VEH_LORRY; break;
      case VEH_AIRCRAFT: type = NETWORK_VEH_PLANE; break;
      case VEH_SHIP: type = NETWORK_VEH_SHIP; break;
      default: continue;
    }
    stats[v->owner].num_vehicle[type]++;
  }
 
  /* Go through all stations and count the types of stations */
  for (const Station *s : Station::Iterate()) {
    if (Company::IsValidID(s->owner)) {
      NetworkCompanyStats *npi = &stats[s->owner];
 
      if (s->facilities & FACIL_TRAIN)      npi->num_station[NETWORK_VEH_TRAIN]++;
      if (s->facilities & FACIL_TRUCK_STOP) npi->num_station[NETWORK_VEH_LORRY]++;
      if (s->facilities & FACIL_BUS_STOP)   npi->num_station[NETWORK_VEH_BUS]++;
      if (s->facilities & FACIL_AIRPORT)    npi->num_station[NETWORK_VEH_PLANE]++;
      if (s->facilities & FACIL_DOCK)       npi->num_station[NETWORK_VEH_SHIP]++;
    }
  }
}
 
void NetworkUpdateClientInfo(ClientID client_id)
{
  NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(client_id);
 
  if (ci == nullptr) return;
 
  DEBUG(desync, 1, "client: %08x; %02x; %02x; %04x", _date, _date_fract, (int)ci->client_playas, client_id);
 
  for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
    if (cs->status >= ServerNetworkGameSocketHandler::STATUS_AUTHORIZED) {
      cs->SendClientInfo(ci);
    }
  }
 
  NetworkAdminClientUpdate(ci);
}
 
static void NetworkCheckRestartMap()
{
  if (_settings_client.network.restart_game_year != 0 && _cur_year >= _settings_client.network.restart_game_year) {
    DEBUG(net, 0, "Auto-restarting map. Year %d reached", _cur_year);
 
    _settings_newgame.game_creation.generation_seed = GENERATE_NEW_SEED;
    switch(_file_to_saveload.abstract_ftype) {
      case FT_SAVEGAME:
      case FT_SCENARIO:
        _switch_mode = SM_LOAD_GAME;
        break;
 
      case FT_HEIGHTMAP:
        _switch_mode = SM_START_HEIGHTMAP;
        break;
 
      default:
        _switch_mode = SM_NEWGAME;
    }
  }
}
 
static void NetworkAutoCleanCompanies()
{
  bool clients_in_company[MAX_COMPANIES];
  int vehicles_in_company[MAX_COMPANIES];
 
  if (!_settings_client.network.autoclean_companies) return;
 
  memset(clients_in_company, 0, sizeof(clients_in_company));
 
  /* Detect the active companies */
  for (const NetworkClientInfo *ci : NetworkClientInfo::Iterate()) {
    if (Company::IsValidID(ci->client_playas)) clients_in_company[ci->client_playas] = true;
  }
 
  if (!_network_dedicated) {
    const NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(CLIENT_ID_SERVER);
    if (Company::IsValidID(ci->client_playas)) clients_in_company[ci->client_playas] = true;
  }
 
  if (_settings_client.network.autoclean_novehicles != 0) {
    memset(vehicles_in_company, 0, sizeof(vehicles_in_company));
 
    for (const Vehicle *v : Vehicle::Iterate()) {
      if (!Company::IsValidID(v->owner) || !v->IsPrimaryVehicle()) continue;
      vehicles_in_company[v->owner]++;
    }
  }
 
  /* Go through all the companies */
  for (const Company *c : Company::Iterate()) {
    /* Skip the non-active once */
    if (c->is_ai) continue;
 
    if (!clients_in_company[c->index]) {
      /* The company is empty for one month more */
      _network_company_states[c->index].months_empty++;
 
      /* Is the company empty for autoclean_unprotected-months, and is there no protection? */
      if (_settings_client.network.autoclean_unprotected != 0 && _network_company_states[c->index].months_empty > _settings_client.network.autoclean_unprotected && StrEmpty(_network_company_states[c->index].password)) {
        /* Shut the company down */
        DoCommandP(0, CCA_DELETE | c->index << 16 | CRR_AUTOCLEAN << 24, 0, CMD_COMPANY_CTRL);
        IConsolePrintF(CC_DEFAULT, "Auto-cleaned company #%d with no password", c->index + 1);
      }
      /* Is the company empty for autoclean_protected-months, and there is a protection? */
      if (_settings_client.network.autoclean_protected != 0 && _network_company_states[c->index].months_empty > _settings_client.network.autoclean_protected && !StrEmpty(_network_company_states[c->index].password)) {
        /* Unprotect the company */
        _network_company_states[c->index].password[0] = '\0';
        IConsolePrintF(CC_DEFAULT, "Auto-removed protection from company #%d", c->index + 1);
        _network_company_states[c->index].months_empty = 0;
        NetworkServerUpdateCompanyPassworded(c->index, false);
      }
      /* Is the company empty for autoclean_novehicles-months, and has no vehicles? */
      if (_settings_client.network.autoclean_novehicles != 0 && _network_company_states[c->index].months_empty > _settings_client.network.autoclean_novehicles && vehicles_in_company[c->index] == 0) {
        /* Shut the company down */
        DoCommandP(0, CCA_DELETE | c->index << 16 | CRR_AUTOCLEAN << 24, 0, CMD_COMPANY_CTRL);
        IConsolePrintF(CC_DEFAULT, "Auto-cleaned company #%d with no vehicles", c->index + 1);
      }
    } else {
      /* It is not empty, reset the date */
      _network_company_states[c->index].months_empty = 0;
    }
  }
}
 
bool NetworkFindName(char *new_name, const char *last)
{
  bool found_name = false;
  uint number = 0;
  char original_name[NETWORK_CLIENT_NAME_LENGTH];
 
  strecpy(original_name, new_name, lastof(original_name));
 
  while (!found_name) {
    found_name = true;
    for (const NetworkClientInfo *ci : NetworkClientInfo::Iterate()) {
      if (strcmp(ci->client_name, new_name) == 0) {
        /* Name already in use */
        found_name = false;
        break;
      }
    }
    /* Check if it is the same as the server-name */
    const NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(CLIENT_ID_SERVER);
    if (ci != nullptr) {
      if (strcmp(ci->client_name, new_name) == 0) found_name = false; // name already in use
    }
 
    if (!found_name) {
      /* Try a new name (<name> #1, <name> #2, and so on) */
 
      /* Something's really wrong when there're more names than clients */
      if (number++ > MAX_CLIENTS) break;
      seprintf(new_name, last, "%s #%d", original_name, number);
    }
  }
 
  return found_name;
}
 
bool NetworkServerChangeClientName(ClientID client_id, const char *new_name)
{
  /* Check if the name's already in use */
  for (NetworkClientInfo *ci : NetworkClientInfo::Iterate()) {
    if (strcmp(ci->client_name, new_name) == 0) return false;
  }
 
  NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(client_id);
  if (ci == nullptr) return false;
 
  NetworkTextMessage(NETWORK_ACTION_NAME_CHANGE, CC_DEFAULT, true, ci->client_name, new_name);
 
  strecpy(ci->client_name, new_name, lastof(ci->client_name));
 
  NetworkUpdateClientInfo(client_id);
  return true;
}
 
void NetworkServerSetCompanyPassword(CompanyID company_id, const char *password, bool already_hashed)
{
  if (!Company::IsValidHumanID(company_id)) return;
 
  if (!already_hashed) {
    password = GenerateCompanyPasswordHash(password, _settings_client.network.network_id, _settings_game.game_creation.generation_seed);
  }
 
  strecpy(_network_company_states[company_id].password, password, lastof(_network_company_states[company_id].password));
  NetworkServerUpdateCompanyPassworded(company_id, !StrEmpty(_network_company_states[company_id].password));
}
 
static void NetworkHandleCommandQueue(NetworkClientSocket *cs)
{
  CommandPacket *cp;
  while ((cp = cs->outgoing_queue.Pop()) != nullptr) {
    cs->SendCommand(cp);
    free(cp);
  }
}
 
void NetworkServer_Tick(bool send_frame)
{
#ifndef ENABLE_NETWORK_SYNC_EVERY_FRAME
  bool send_sync = false;
#endif
 
#ifndef ENABLE_NETWORK_SYNC_EVERY_FRAME
  if (_frame_counter >= _last_sync_frame + _settings_client.network.sync_freq) {
    _last_sync_frame = _frame_counter;
    send_sync = true;
  }
#endif
 
  /* Now we are done with the frame, inform the clients that they can
   *  do their frame! */
  for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
    /* We allow a number of bytes per frame, but only to the burst amount
     * to be available for packet receiving at any particular time. */
    cs->receive_limit = std::min<int>(cs->receive_limit + _settings_client.network.bytes_per_frame,
        _settings_client.network.bytes_per_frame_burst);
 
    /* Check if the speed of the client is what we can expect from a client */
    uint lag = NetworkCalculateLag(cs);
    switch (cs->status) {
      case NetworkClientSocket::STATUS_ACTIVE:
        if (lag > _settings_client.network.max_lag_time) {
          /* Client did still not report in within the specified limit. */
          IConsolePrintF(CC_ERROR, cs->last_packet + std::chrono::milliseconds(lag * MILLISECONDS_PER_TICK) > std::chrono::steady_clock::now() ?
              /* A packet was received in the last three game days, so the client is likely lagging behind. */
                "Client #%d is dropped because the client's game state is more than %d ticks behind" :
              /* No packet was received in the last three game days; sounds like a lost connection. */
                "Client #%d is dropped because the client did not respond for more than %d ticks",
              cs->client_id, lag);
          cs->SendError(NETWORK_ERROR_TIMEOUT_COMPUTER);
          continue;
        }
 
        /* Report once per time we detect the lag, and only when we
         * received a packet in the last 2 seconds. If we
         * did not receive a packet, then the client is not just
         * slow, but the connection is likely severed. Mentioning
         * frame_freq is not useful in this case. */
        if (lag > (uint)DAY_TICKS && cs->lag_test == 0 && cs->last_packet + std::chrono::seconds(2) > std::chrono::steady_clock::now()) {
          IConsolePrintF(CC_WARNING, "[%d] Client #%d is slow, try increasing [network.]frame_freq to a higher value!", _frame_counter, cs->client_id);
          cs->lag_test = 1;
        }
 
        if (cs->last_frame_server - cs->last_token_frame >= _settings_client.network.max_lag_time) {
          /* This is a bad client! It didn't send the right token back within time. */
          IConsolePrintF(CC_ERROR, "Client #%d is dropped because it fails to send valid acks", cs->client_id);
          cs->SendError(NETWORK_ERROR_TIMEOUT_COMPUTER);
          continue;
        }
        break;
 
      case NetworkClientSocket::STATUS_INACTIVE:
      case NetworkClientSocket::STATUS_NEWGRFS_CHECK:
      case NetworkClientSocket::STATUS_AUTHORIZED:
        /* NewGRF check and authorized states should be handled almost instantly.
         * So give them some lee-way, likewise for the query with inactive. */
        if (lag > _settings_client.network.max_init_time) {
          IConsolePrintF(CC_ERROR, "Client #%d is dropped because it took longer than %d ticks to start the joining process", cs->client_id, _settings_client.network.max_init_time);
          cs->SendError(NETWORK_ERROR_TIMEOUT_COMPUTER);
          continue;
        }
        break;
 
      case NetworkClientSocket::STATUS_MAP_WAIT:
        /* Send every two seconds a packet to the client, to make sure
         * he knows the server is still there; just someone else is
         * still receiving the map. */
        if (std::chrono::steady_clock::now() > cs->last_packet + std::chrono::seconds(2)) {
          cs->SendWait();
          /* We need to reset the timer, as otherwise we will be
           * spamming the client. Strictly speaking this variable
           * tracks when we last received a packet from the client,
           * but as he is waiting, he will not send us any till we
           * start sending him data. */
          cs->last_packet = std::chrono::steady_clock::now();
        }
        break;
 
      case NetworkClientSocket::STATUS_MAP:
        /* Downloading the map... this is the amount of time since starting the saving. */
        if (lag > _settings_client.network.max_download_time) {
          IConsolePrintF(CC_ERROR, "Client #%d is dropped because it took longer than %d ticks to download the map", cs->client_id, _settings_client.network.max_download_time);
          cs->SendError(NETWORK_ERROR_TIMEOUT_MAP);
          continue;
        }
        break;
 
      case NetworkClientSocket::STATUS_DONE_MAP:
      case NetworkClientSocket::STATUS_PRE_ACTIVE:
        /* The map has been sent, so this is for loading the map and syncing up. */
        if (lag > _settings_client.network.max_join_time) {
          IConsolePrintF(CC_ERROR, "Client #%d is dropped because it took longer than %d ticks to join", cs->client_id, _settings_client.network.max_join_time);
          cs->SendError(NETWORK_ERROR_TIMEOUT_JOIN);
          continue;
        }
        break;
 
      case NetworkClientSocket::STATUS_AUTH_GAME:
      case NetworkClientSocket::STATUS_AUTH_COMPANY:
        /* These don't block? */
        if (lag > _settings_client.network.max_password_time) {
          IConsolePrintF(CC_ERROR, "Client #%d is dropped because it took longer than %d ticks to enter the password", cs->client_id, _settings_client.network.max_password_time);
          cs->SendError(NETWORK_ERROR_TIMEOUT_PASSWORD);
          continue;
        }
        break;
 
      case NetworkClientSocket::STATUS_END:
        /* Bad server/code. */
        NOT_REACHED();
    }
 
    if (cs->status >= NetworkClientSocket::STATUS_PRE_ACTIVE) {
      /* Check if we can send command, and if we have anything in the queue */
      NetworkHandleCommandQueue(cs);
 
      /* Send an updated _frame_counter_max to the client */
      if (send_frame) cs->SendFrame();
 
#ifndef ENABLE_NETWORK_SYNC_EVERY_FRAME
      /* Send a sync-check packet */
      if (send_sync) cs->SendSync();
#endif
    }
  }
 
  /* See if we need to advertise */
  NetworkUDPAdvertise();
}
 
void NetworkServerYearlyLoop()
{
  NetworkCheckRestartMap();
  NetworkAdminUpdate(ADMIN_FREQUENCY_ANUALLY);
}
 
void NetworkServerMonthlyLoop()
{
  NetworkAutoCleanCompanies();
  NetworkAdminUpdate(ADMIN_FREQUENCY_MONTHLY);
  if ((_cur_month % 3) == 0) NetworkAdminUpdate(ADMIN_FREQUENCY_QUARTERLY);
}
 
void NetworkServerDailyLoop()
{
  NetworkAdminUpdate(ADMIN_FREQUENCY_DAILY);
  if ((_date % 7) == 3) NetworkAdminUpdate(ADMIN_FREQUENCY_WEEKLY);
}
 
const char *ServerNetworkGameSocketHandler::GetClientIP()
{
  return this->client_address.GetHostname();
}
 
void NetworkServerShowStatusToConsole()
{
  static const char * const stat_str[] = {
    "inactive",
    "checking NewGRFs",
    "authorizing (server password)",
    "authorizing (company password)",
    "authorized",
    "waiting",
    "loading map",
    "map done",
    "ready",
    "active"
  };
  static_assert(lengthof(stat_str) == NetworkClientSocket::STATUS_END);
 
  for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
    NetworkClientInfo *ci = cs->GetInfo();
    if (ci == nullptr) continue;
    uint lag = NetworkCalculateLag(cs);
    const char *status;
 
    status = (cs->status < (ptrdiff_t)lengthof(stat_str) ? stat_str[cs->status] : "unknown");
    IConsolePrintF(CC_INFO, "Client #%1d  name: '%s'  status: '%s'  frame-lag: %3d  company: %1d  IP: %s",
      cs->client_id, ci->client_name, status, lag,
      ci->client_playas + (Company::IsValidID(ci->client_playas) ? 1 : 0),
      cs->GetClientIP());
  }
}
 
void NetworkServerSendConfigUpdate()
{
  for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
    if (cs->status >= NetworkClientSocket::STATUS_PRE_ACTIVE) cs->SendConfigUpdate();
  }
}
 
void NetworkServerUpdateCompanyPassworded(CompanyID company_id, bool passworded)
{
  if (NetworkCompanyIsPassworded(company_id) == passworded) return;
 
  SB(_network_company_passworded, company_id, 1, !!passworded);
  SetWindowClassesDirty(WC_COMPANY);
 
  for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
    if (cs->status >= NetworkClientSocket::STATUS_PRE_ACTIVE) cs->SendCompanyUpdate();
  }
 
  NetworkAdminCompanyUpdate(Company::GetIfValid(company_id));
}
 
void NetworkServerDoMove(ClientID client_id, CompanyID company_id)
{
  /* Only allow non-dedicated servers and normal clients to be moved */
  if (client_id == CLIENT_ID_SERVER && _network_dedicated) return;
 
  NetworkClientInfo *ci = NetworkClientInfo::GetByClientID(client_id);
 
  /* No need to waste network resources if the client is in the company already! */
  if (ci->client_playas == company_id) return;
 
  ci->client_playas = company_id;
 
  if (client_id == CLIENT_ID_SERVER) {
    SetLocalCompany(company_id);
  } else {
    NetworkClientSocket *cs = NetworkClientSocket::GetByClientID(client_id);
    /* When the company isn't authorized we can't move them yet. */
    if (cs->status < NetworkClientSocket::STATUS_AUTHORIZED) return;
    cs->SendMove(client_id, company_id);
  }
 
  /* announce the client's move */
  NetworkUpdateClientInfo(client_id);
 
  NetworkAction action = (company_id == COMPANY_SPECTATOR) ? NETWORK_ACTION_COMPANY_SPECTATOR : NETWORK_ACTION_COMPANY_JOIN;
  NetworkServerSendChat(action, DESTTYPE_BROADCAST, 0, "", client_id, company_id + 1);
}
 
void NetworkServerSendRcon(ClientID client_id, TextColour colour_code, const char *string)
{
  NetworkClientSocket::GetByClientID(client_id)->SendRConResult(colour_code, string);
}
 
void NetworkServerKickClient(ClientID client_id, const char *reason)
{
  if (client_id == CLIENT_ID_SERVER) return;
  NetworkClientSocket::GetByClientID(client_id)->SendError(NETWORK_ERROR_KICKED, reason);
}
 
uint NetworkServerKickOrBanIP(ClientID client_id, bool ban, const char *reason)
{
  return NetworkServerKickOrBanIP(NetworkClientSocket::GetByClientID(client_id)->GetClientIP(), ban, reason);
}
 
uint NetworkServerKickOrBanIP(const char *ip, bool ban, const char *reason)
{
  /* Add address to ban-list */
  if (ban) {
    bool contains = false;
    for (const auto &iter : _network_ban_list) {
      if (iter == ip) {
        contains = true;
        break;
      }
    }
    if (!contains) _network_ban_list.emplace_back(ip);
  }
 
  uint n = 0;
 
  /* There can be multiple clients with the same IP, kick them all but don't kill the server,
   * or the client doing the rcon. The latter can't be kicked because kicking frees closes
   * and subsequently free the connection related instances, which we would be reading from
   * and writing to after returning. So we would read or write data from freed memory up till
   * the segfault triggers. */
  for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
    if (cs->client_id == CLIENT_ID_SERVER) continue;
    if (cs->client_id == _redirect_console_to_client) continue;
    if (cs->client_address.IsInNetmask(ip)) {
      NetworkServerKickClient(cs->client_id, reason);
      n++;
    }
  }
 
  return n;
}
 
bool NetworkCompanyHasClients(CompanyID company)
{
  for (const NetworkClientInfo *ci : NetworkClientInfo::Iterate()) {
    if (ci->client_playas == company) return true;
  }
  return false;
}
 
 
void ServerNetworkGameSocketHandler::GetClientName(char *client_name, const char *last) const
{
  const NetworkClientInfo *ci = this->GetInfo();
 
  if (ci == nullptr || StrEmpty(ci->client_name)) {
    seprintf(client_name, last, "Client #%4d", this->client_id);
  } else {
    strecpy(client_name, ci->client_name, last);
  }
}
 
void NetworkPrintClients()
{
  for (NetworkClientInfo *ci : NetworkClientInfo::Iterate()) {
    if (_network_server) {
      IConsolePrintF(CC_INFO, "Client #%1d  name: '%s'  company: %1d  IP: %s",
          ci->client_id,
          ci->client_name,
          ci->client_playas + (Company::IsValidID(ci->client_playas) ? 1 : 0),
          ci->client_id == CLIENT_ID_SERVER ? "server" : NetworkClientSocket::GetByClientID(ci->client_id)->GetClientIP());
    } else {
      IConsolePrintF(CC_INFO, "Client #%1d  name: '%s'  company: %1d",
          ci->client_id,
          ci->client_name,
          ci->client_playas + (Company::IsValidID(ci->client_playas) ? 1 : 0));
    }
  }
}
 
void NetworkServerNewCompany(const Company *c, NetworkClientInfo *ci)
{
  assert(c != nullptr);
 
  if (!_network_server) return;
 
  _network_company_states[c->index].months_empty = 0;
  _network_company_states[c->index].password[0] = '\0';
  NetworkServerUpdateCompanyPassworded(c->index, false);
 
  if (ci != nullptr) {
    /* ci is nullptr when replaying, or for AIs. In neither case there is a client. */
    ci->client_playas = c->index;
    NetworkUpdateClientInfo(ci->client_id);
    NetworkSendCommand(0, 0, 0, CMD_RENAME_PRESIDENT, nullptr, ci->client_name, c->index);
  }
 
  /* Announce new company on network. */
  NetworkAdminCompanyInfo(c, true);
 
  if (ci != nullptr) {
    /* ci is nullptr when replaying, or for AIs. In neither case there is a client.
       We need to send Admin port update here so that they first know about the new company
       and then learn about a possibly joining client (see FS#6025) */
    NetworkServerSendChat(NETWORK_ACTION_COMPANY_NEW, DESTTYPE_BROADCAST, 0, "", ci->client_id, c->index + 1);
  }
}