1 // multiplayrxmgr.cxx -- routines for receiving multiplayer data
4 // Written by Duncan McCreanor, started February 2003.
5 // duncan.mccreanor@airservicesaustralia.com
7 // Copyright (C) 2003 Airservices Australia
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.
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.
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.
25 /******************************************************************
28 * Description: The multiplayer rx manager provides control over
29 * multiplayer data reception and processing for an interactive
30 * multiplayer FlightGear simulation.
32 * The objects that hold player information are accessed via
33 * a fixed size array. A fixed array is used since it provides
34 * speed benefits over working with linked lists and is easier
35 * to code. Also, there is no point allowing for an unlimited
36 * number of players as too many players will slow the game
37 * down to the point where it is unplayable.
39 * When player position data is received, the callsign of
40 * the player is checked against existing players. If the
41 * player does not exist, a new player is created in the
42 * next free slot of the player array. If the player does
43 * exist, the player's positional matrix is updated.
45 * The Update method is used to move the players on the
46 * scene. The return value from calling MPPlayer::Draw
47 * indicates the state of the player. If data for a player
48 * has not been received data for some time, the player object
49 * is deleted and the array element freed.
51 ******************************************************************/
53 #include <sys/types.h>
54 #include <sys/socket.h>
55 #include <netinet/in.h>
56 #include <arpa/inet.h>
57 #include <plib/netSocket.h>
60 #include <simgear/debug/logstream.hxx>
61 #include <Main/fg_props.hxx>
63 #include "multiplayrxmgr.hxx"
64 #include "mpmessages.hxx"
65 #include "mpplayer.hxx"
67 #define MAX_PACKET_SIZE 1024
69 // These constants are provided so that the ident command can list file versions.
70 const char sMULTIPLAYTXMGR_BID[] = "$Id$";
71 const char sMULTIPLAYRXMGR_HID[] = MULTIPLAYRXMGR_HID;
75 /******************************************************************
76 * Name: FGMultiplayRxMgr
77 * Description: Constructor.
78 ******************************************************************/
79 FGMultiplayRxMgr::FGMultiplayRxMgr() {
81 int iPlayerCnt; // Count of players in player array
83 // Initialise private members
86 m_bInitialised = false;
88 // Clear the player array
89 for (iPlayerCnt = 0; iPlayerCnt < MAX_PLAYERS; iPlayerCnt++) {
90 m_Player[iPlayerCnt] = NULL;
96 /******************************************************************
97 * Name: ~FGMultiplayRxMgr
98 * Description: Destructor. Closes and deletes objects owned by
100 ******************************************************************/
101 FGMultiplayRxMgr::~FGMultiplayRxMgr() {
108 /******************************************************************
110 * Description: Initialises multiplayer receive.
111 ******************************************************************/
112 bool FGMultiplayRxMgr::init(void) {
114 bool bSuccess = true; // Result of initialisation
116 // Initialise object if not already done
117 if (!m_bInitialised) {
119 // Set members from property values
120 m_sCallsign = fgGetString("/sim/multiplay/callsign");
121 m_sRxAddress = fgGetString("/sim/multiplay/rxhost");
122 m_iRxPort = fgGetInt("/sim/multiplay/rxport");
124 SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::init - rxaddress= "
126 SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::init - rxport= "
128 SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::init - callsign= "
132 // Create and open rx socket
133 mDataRxSocket = new netSocket();
134 if (!mDataRxSocket->open(false)) {
135 // Failed to open rx socket
136 cerr << "FGMultiplayRxMgr::Open - Failed to create data receive socket" << endl;
140 // Configure the socket
141 mDataRxSocket->setBlocking(false);
142 mDataRxSocket->setBroadcast(true);
143 if (mDataRxSocket->bind(m_sRxAddress.c_str(), m_iRxPort) != 0) {
146 cerr << "FGMultiplayRxMgr::Open - Failed to bind receive socket" << endl;
152 // Save manager state
153 m_bInitialised = bSuccess;
156 cerr << "FGMultiplayRxMgr::OpenRx - Receiver open requested when receiver is already open" << endl;
160 /* Return true if open succeeds */
166 /******************************************************************
168 * Description: Closes and deletes and player connections. Closes
169 * and deletes the rx socket. Resets the object state
171 ******************************************************************/
172 void FGMultiplayRxMgr::Close(void) {
174 int iPlayerCnt; // Count of players in player array
176 // Delete any existing players
177 for (iPlayerCnt = 0; iPlayerCnt < MAX_PLAYERS; iPlayerCnt++) {
178 if (m_Player[iPlayerCnt] != NULL) {
179 delete m_Player[iPlayerCnt];
180 m_Player[iPlayerCnt] = NULL;
186 mDataRxSocket->close();
187 delete mDataRxSocket;
188 mDataRxSocket = NULL;
191 m_bInitialised = false;
196 /******************************************************************
198 * Description: Processes data waiting at the receive socket. The
199 * processing ends when there is no more data at the socket.
200 ******************************************************************/
201 void FGMultiplayRxMgr::ProcessData(void) {
203 char sMsg[MAX_PACKET_SIZE]; // Buffer for received message
204 int iBytes; // Bytes received
205 T_MsgHdr *MsgHdr; // Pointer to header in received data
206 T_ChatMsg *ChatMsg; // Pointer to chat message in received data
207 T_PositionMsg *PosMsg; // Pointer to position message in received data
208 char *sIpAddress; // Address information from header
209 char *sModelName; // Model that the remote player is using
210 char *sCallsign; // Callsign of the remote player
211 struct in_addr PlayerAddress; // Used for converting the player's address into dot notation
212 int iPlayerCnt; // Count of players in player array
213 bool bActivePlayer = false; // The state of the player that sent the data
214 int iPort; // Port that the remote player receives on
217 if (m_bInitialised) {
219 // Read the receive socket and process any data
222 // Although the recv call asks for MAX_PACKET_SIZE of data,
223 // the number of bytes returned will only be that of the next
224 // packet waiting to be processed.
225 iBytes = mDataRxSocket->recv(sMsg, MAX_PACKET_SIZE, 0);
229 if (iBytes >= sizeof(MsgHdr)) {
232 MsgHdr = (T_MsgHdr *)sMsg;
233 PlayerAddress.s_addr = MsgHdr->lReplyAddress;
234 sIpAddress = inet_ntoa(PlayerAddress);
235 iPort = MsgHdr->iReplyPort;
236 sCallsign = MsgHdr->sCallsign;
238 // Process the player data unless we generated it
239 if (m_sCallsign != MsgHdr->sCallsign) {
243 switch(MsgHdr->MsgId) {
245 if (MsgHdr->iMsgLen == sizeof(T_MsgHdr) + sizeof(T_ChatMsg)) {
246 ChatMsg = (T_ChatMsg *)(sMsg + sizeof(T_MsgHdr));
247 SG_LOG( SG_NETWORK, SG_BULK, "Chat [" << MsgHdr->sCallsign << "]" << " " << ChatMsg->sText );
249 SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayRxMgr::MP_ProcessData - Chat message received with insufficient data" );
254 if (MsgHdr->iMsgLen == sizeof(T_MsgHdr) + sizeof(T_PositionMsg)) {
255 PosMsg = (T_PositionMsg *)(sMsg + sizeof(T_MsgHdr));
256 sModelName = PosMsg->sModel;
258 // Check if the player is already in the game by using the Callsign.
259 bActivePlayer = false;
260 for (iPlayerCnt = 0; iPlayerCnt < MAX_PLAYERS; iPlayerCnt++) {
261 if (m_Player[iPlayerCnt] != NULL) {
262 if (m_Player[iPlayerCnt]->CompareCallsign(MsgHdr->sCallsign)) {
264 // Player found. Update the data for the player.
265 m_Player[iPlayerCnt]->SetPosition(PosMsg->PlayerPos);
266 bActivePlayer = true;
272 // Player not active, so add as new player
273 if (!bActivePlayer) {
276 if (m_Player[iPlayerCnt] == NULL) {
277 SG_LOG( SG_NETWORK, SG_INFO, "FGMultiplayRxMgr::ProcessRxData - Add new player. IP: " << sIpAddress << ", Call: " << sCallsign << ", model: " << sModelName );
278 m_Player[iPlayerCnt] = new MPPlayer;
279 m_Player[iPlayerCnt]->Open(string(sIpAddress), iPort, string(sCallsign), string(sModelName), false);
280 m_Player[iPlayerCnt]->SetPosition(PosMsg->PlayerPos);
281 bActivePlayer = true;
284 } while (iPlayerCnt < MAX_PLAYERS && !bActivePlayer);
286 // Check if the player was added
287 if (!bActivePlayer) {
288 if (iPlayerCnt == MAX_PLAYERS) {
289 cerr << "FGMultiplayRxMgr::MP_ProcessData - Unable to add new player (" << sCallsign << "). Too many players." << endl;
295 cerr << "FGMultiplayRxMgr::MP_ProcessData - Position message received with insufficient data" << endl;
300 cerr << "FGMultiplayRxMgr::MP_ProcessData - Unknown message Id received: " << MsgHdr->MsgId << endl;
310 } else if (iBytes == -1) {
311 if (errno != EAGAIN) {
312 perror("FGMultiplayRxMgr::MP_ProcessData");
316 } while (iBytes > 0);
324 /******************************************************************
326 * Description: For each active player, tell the player object
327 * to update its position on the scene. If a player object
328 * returns status information indicating that it has not
329 * had an update for some time then the player is deleted.
330 ******************************************************************/
331 void FGMultiplayRxMgr::Update(void) {
333 int iPlayerDataState;
336 for (iPlayerId = 0; iPlayerId < MAX_PLAYERS; iPlayerId++) {
337 if (m_Player[iPlayerId] != NULL) {
338 iPlayerDataState = m_Player[iPlayerId]->Draw();
340 // If the player has not received an update for some
341 // time then assume that the player has quit.
342 if (iPlayerDataState == PLAYER_DATA_EXPIRED) {
343 delete m_Player[iPlayerId];
344 m_Player[iPlayerId] = NULL;