src/MultiPlayer/multiplayrxmgr.cxx

   1 // multiplayrxmgr.cxx -- routines for receiving multiplayer data
   2 //                       for Flightgear
   3 //
   4 // Written by Duncan McCreanor, started February 2003.
   5 // duncan.mccreanor@airservicesaustralia.com
   6 //
   7 // Copyright (C) 2003  Airservices Australia
   8 //
   9 // This program is free software; you can redistribute it and/or
  10 // modify it under the terms of the GNU General Public License as
  11 // published by the Free Software Foundation; either version 2 of the
  12 // License, or (at your option) any later version.
  13 //
  14 // This program is distributed in the hope that it will be useful, but
  15 // WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 // General Public License for more details.
  18 //
  19 // You should have received a copy of the GNU General Public License
  20 // along with this program; if not, write to the Free Software
  21 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 //
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #ifdef FG_MPLAYER_AS
  29
  30 /******************************************************************
  31 * $Id$
  32 *
  33 * Description: The multiplayer rx manager provides control over
  34 * multiplayer data reception and processing for an interactive
  35 * multiplayer FlightGear simulation.
  36 *
  37 * The objects that hold player information are accessed via
  38 * a fixed size array. A fixed array is used since it provides
  39 * speed benefits over working with linked lists and is easier
  40 * to code. Also, there is no point allowing for an unlimited
  41 * number of players as too many players will slow the game
  42 * down to the point where it is unplayable.
  43 *
  44 * When player position data is received, the callsign of
  45 * the player is checked against existing players. If the
  46 * player does not exist, a new player is created in the
  47 * next free slot of the player array. If the player does
  48 * exist, the player's positional matrix is updated.
  49 *
  50 * The Update method is used to move the players on the
  51 * scene. The return value from calling MPPlayer::Draw
  52 * indicates the state of the player. If data for a player
  53 * has not been received data for some time, the player object
  54 * is deleted and the array element freed.
  55 *
  56 ******************************************************************/
  57
  58 #include <sys/types.h>
  59 #if !(defined(_MSC_VER) || defined(__MINGW32__))
  60 # include <sys/socket.h>
  61 # include <netinet/in.h>
  62 # include <arpa/inet.h>
  63 #endif
  64 #include <plib/netSocket.h>
  65 #include <stdlib.h>
  66
  67 #include <simgear/debug/logstream.hxx>
  68 #include <Main/fg_props.hxx>
  69
  70 #include "multiplayrxmgr.hxx"
  71 #include "mpmessages.hxx"
  72 #include "mpplayer.hxx"
  73
  74 #define MAX_PACKET_SIZE 1024
  75
  76 // These constants are provided so that the ident command can list file versions.
  77 const char sMULTIPLAYTXMGR_BID[] = "$Id$";
  78 const char sMULTIPLAYRXMGR_HID[] = MULTIPLAYRXMGR_HID;
  79
  80
  81
  82 /******************************************************************
  83 * Name: FGMultiplayRxMgr
  84 * Description: Constructor.
  85 ******************************************************************/
  86 FGMultiplayRxMgr::FGMultiplayRxMgr() {
  87
  88     int iPlayerCnt;         // Count of players in player array
  89
  90     // Initialise private members
  91     m_sRxAddress = "0";
  92     m_iRxPort = 0;
  93     m_bInitialised = false;
  94
  95     // Clear the player array
  96     for (iPlayerCnt = 0; iPlayerCnt < MAX_PLAYERS; iPlayerCnt++) {
  97         m_Player[iPlayerCnt] = NULL;
  98     }
  99
 100 }
 101
 102
 103 /******************************************************************
 104 * Name: ~FGMultiplayRxMgr
 105 * Description: Destructor. Closes and deletes objects owned by
 106 * this object.
 107 ******************************************************************/
 108 FGMultiplayRxMgr::~FGMultiplayRxMgr() {
 109
 110     Close();
 111
 112 }
 113
 114
 115 /******************************************************************
 116 * Name: init
 117 * Description: Initialises multiplayer receive.
 118 ******************************************************************/
 119 bool FGMultiplayRxMgr::init(void) {
 120
 121     bool bSuccess = true;                       // Result of initialisation
 122
 123     // Initialise object if not already done
 124     if (!m_bInitialised) {
 125
 126         // Set members from property values
 127         m_sCallsign = fgGetString("/sim/multiplay/callsign");
 128         m_sRxAddress = fgGetString("/sim/multiplay/rxhost");
 129         m_iRxPort = fgGetInt("/sim/multiplay/rxport");
 130
 131         SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::init - rxaddress= "
 132                                      << m_sRxAddress );
 133         SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::init - rxport= "
 134                                      << m_iRxPort);
 135         SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::init - callsign= "
 136                                      << m_sCallsign );
 137
 138
 139         // Create and open rx socket
 140         mDataRxSocket = new netSocket();
 141         if (!mDataRxSocket->open(false)) {
 142             // Failed to open rx socket
 143             SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::Open - Failed to create data receive socket" );
 144             bSuccess = false;
 145         } else {
 146
 147             // Configure the socket
 148             mDataRxSocket->setBlocking(false);
 149             mDataRxSocket->setBroadcast(true);
 150             if (mDataRxSocket->bind(m_sRxAddress.c_str(), m_iRxPort) != 0) {
 151                 perror("bind");
 152                 // Failed to bind
 153                 SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::Open - Failed to bind receive socket" );
 154                 bSuccess = false;
 155             }
 156
 157         }
 158
 159         // Save manager state
 160         m_bInitialised = bSuccess;
 161
 162     } else {
 163         SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::OpenRx - Receiver open requested when receiver is already open" );
 164         bSuccess = false;
 165     }
 166
 167     /* Return true if open succeeds */
 168     return bSuccess;
 169
 170 }
 171
 172
 173 /******************************************************************
 174 * Name: Close
 175 * Description: Closes and deletes and player connections. Closes
 176 * and deletes the rx socket. Resets the object state
 177 * to unitialised.
 178 ******************************************************************/
 179 void FGMultiplayRxMgr::Close(void) {
 180
 181     int iPlayerCnt;         // Count of players in player array
 182
 183     // Delete any existing players
 184     for (iPlayerCnt = 0; iPlayerCnt < MAX_PLAYERS; iPlayerCnt++) {
 185         if (m_Player[iPlayerCnt] != NULL) {
 186             delete m_Player[iPlayerCnt];
 187             m_Player[iPlayerCnt] = NULL;
 188         }
 189     }
 190
 191     // Delete socket
 192     if (mDataRxSocket) {
 193         mDataRxSocket->close();
 194         delete mDataRxSocket;
 195         mDataRxSocket = NULL;
 196     }
 197
 198     m_bInitialised = false;
 199
 200 }
 201
 202
 203 /******************************************************************
 204 * Name: ProcessData
 205 * Description: Processes data waiting at the receive socket. The
 206 * processing ends when there is no more data at the socket.
 207 ******************************************************************/
 208 void FGMultiplayRxMgr::ProcessData(void) {
 209
 210     char sMsg[MAX_PACKET_SIZE];         // Buffer for received message
 211     int iBytes;                         // Bytes received
 212     T_MsgHdr *MsgHdr;                   // Pointer to header in received data
 213     T_ChatMsg *ChatMsg;                 // Pointer to chat message in received data
 214     T_PositionMsg *PosMsg;              // Pointer to position message in received data
 215     char *sIpAddress;                   // Address information from header
 216     char *sModelName;                   // Model that the remote player is using
 217     char *sCallsign;                    // Callsign of the remote player
 218     struct in_addr PlayerAddress;       // Used for converting the player's address into dot notation
 219     int iPlayerCnt;                     // Count of players in player array
 220     bool bActivePlayer = false;         // The state of the player that sent the data
 221     int iPort;                          // Port that the remote player receives on
 222
 223
 224     if (m_bInitialised) {
 225
 226         // Read the receive socket and process any data
 227         do {
 228
 229             // Although the recv call asks for MAX_PACKET_SIZE of data,
 230             // the number of bytes returned will only be that of the next
 231             // packet waiting to be processed.
 232             iBytes = mDataRxSocket->recv(sMsg, MAX_PACKET_SIZE, 0);
 233
 234             // Data received
 235             if (iBytes > 0) {
 236                 if (iBytes >= (int)sizeof(MsgHdr)) {
 237
 238                     // Read header
 239                     MsgHdr = (T_MsgHdr *)sMsg;
 240                     PlayerAddress.s_addr = MsgHdr->lReplyAddress;
 241                     sIpAddress = inet_ntoa(PlayerAddress);
 242                     iPort = MsgHdr->iReplyPort;
 243                     sCallsign = MsgHdr->sCallsign;
 244
 245                     // Process the player data unless we generated it
 246                     if (m_sCallsign != MsgHdr->sCallsign) {
 247
 248
 249                         // Process messages
 250                         switch(MsgHdr->MsgId) {
 251                             case CHAT_MSG_ID:
 252                                 if (MsgHdr->iMsgLen == sizeof(T_MsgHdr) + sizeof(T_ChatMsg)) {
 253                                     ChatMsg = (T_ChatMsg *)(sMsg + sizeof(T_MsgHdr));
 254                                     SG_LOG( SG_NETWORK, SG_BULK, "Chat [" << MsgHdr->sCallsign << "]" << " " << ChatMsg->sText );
 255                                 } else {
 256                                     SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::MP_ProcessData - Chat message received with insufficient data" );
 257                                 }
 258                                 break;
 259
 260                             case POS_DATA_ID:
 261                                 if (MsgHdr->iMsgLen == sizeof(T_MsgHdr) + sizeof(T_PositionMsg)) {
 262                                     PosMsg = (T_PositionMsg *)(sMsg + sizeof(T_MsgHdr));
 263                                     sModelName = PosMsg->sModel;
 264
 265                                     // Check if the player is already in the game by using the Callsign.
 266                                     bActivePlayer = false;
 267                                     for (iPlayerCnt = 0; iPlayerCnt < MAX_PLAYERS; iPlayerCnt++) {
 268                                         if (m_Player[iPlayerCnt] != NULL) {
 269                                             if (m_Player[iPlayerCnt]->CompareCallsign(MsgHdr->sCallsign)) {
 270
 271                                                 // Player found. Update the data for the player.
 272                                                 m_Player[iPlayerCnt]->SetPosition(PosMsg->PlayerPos);
 273                                                 bActivePlayer = true;
 274
 275                                             }
 276                                         }
 277                                     }
 278
 279                                     // Player not active, so add as new player
 280                                     if (!bActivePlayer) {
 281                                         iPlayerCnt = 0;
 282                                         do {
 283                                             if (m_Player[iPlayerCnt] == NULL) {
 284                                                 SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::ProcessRxData - Add new player. IP: " << sIpAddress << ", Call: " <<  sCallsign << ", model: " << sModelName );
 285                                                 m_Player[iPlayerCnt] = new MPPlayer;
 286                                                 m_Player[iPlayerCnt]->Open(sIpAddress, iPort, sCallsign, sModelName, false);
 287                                                 m_Player[iPlayerCnt]->SetPosition(PosMsg->PlayerPos);
 288                                                 bActivePlayer = true;
 289                                             }
 290                                             iPlayerCnt++;
 291                                         } while (iPlayerCnt < MAX_PLAYERS && !bActivePlayer);
 292
 293                                         // Check if the player was added
 294                                         if (!bActivePlayer) {
 295                                             if (iPlayerCnt == MAX_PLAYERS) {
 296                                                 SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::MP_ProcessData - Unable to add new player (" << sCallsign << "). Too many players." );
 297                                             }
 298                                         }
 299                                     }
 300
 301                                 } else {
 302                                     SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::MP_ProcessData - Position message received with insufficient data" );
 303                                 }
 304                                 break;
 305
 306                             default:
 307                                 SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::MP_ProcessData - Unknown message Id received: " << MsgHdr->MsgId );
 308                                 break;
 309
 310
 311                         }
 312                     }
 313                 }
 314
 315
 316             // Error or no data
 317             } else if (iBytes == -1) {
 318                 if (errno != EAGAIN) {
 319                     perror("FGMultiplayRxMgr::MP_ProcessData");
 320                 }
 321             }
 322
 323         } while (iBytes > 0);
 324
 325     }
 326
 327
 328 }
 329
 330
 331 /******************************************************************
 332 * Name: Update
 333 * Description: For each active player, tell the player object
 334 * to update its position on the scene. If a player object
 335 * returns status information indicating that it has not
 336 * had an update for some time then the player is deleted.
 337 ******************************************************************/
 338 void FGMultiplayRxMgr::Update(void) {
 339
 340     MPPlayer::TPlayerDataState ePlayerDataState;
 341     int iPlayerId;
 342
 343     for (iPlayerId = 0; iPlayerId < MAX_PLAYERS; iPlayerId++) {
 344         if (m_Player[iPlayerId] != NULL) {
 345             ePlayerDataState = m_Player[iPlayerId]->Draw();
 346
 347             // If the player has not received an update for some
 348             // time then assume that the player has quit.
 349             if (ePlayerDataState == MPPlayer::PLAYER_DATA_EXPIRED) {
 350                 SG_LOG( SG_NETWORK, SG_BULK, "FGMultiplayRxMgr::Update - Deleting player from game. Callsign: "
 351                         << m_Player[iPlayerId]->Callsign() );
 352                 delete m_Player[iPlayerId];
 353                 m_Player[iPlayerId] = NULL;
 354             }
 355
 356         }
 357     }
 358
 359 }
 360
 361 #endif // FG_MPLAYER_AS
 362