src/MultiPlayer/multiplaymgr.cxx

   1 //////////////////////////////////////////////////////////////////////
   2 //
   3 // multiplaymgr.hpp
   4 //
   5 // Written by Duncan McCreanor, started February 2003.
   6 // duncan.mccreanor@airservicesaustralia.com
   7 //
   8 // Copyright (C) 2003  Airservices Australia
   9 // Copyright (C) 2005  Oliver Schroeder
  10 // Copyright (C) 2006  Mathias Froehlich
  11 //
  12 // This program is free software; you can redistribute it and/or
  13 // modify it under the terms of the GNU General Public License as
  14 // published by the Free Software Foundation; either version 2 of the
  15 // License, or (at your option) any later version.
  16 //
  17 // This program is distributed in the hope that it will be useful, but
  18 // WITHOUT ANY WARRANTY; without even the implied warranty of
  19 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20 // General Public License for more details.
  21 //
  22 // You should have received a copy of the GNU General Public License
  23 // along with this program; if not, write to the Free Software
  24 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  25 //
  26 // $Id$
  27 //
  28 //////////////////////////////////////////////////////////////////////
  29
  30 #ifdef HAVE_CONFIG_H
  31 #include <config.h>
  32 #endif
  33
  34 #include <iostream>
  35 #include <algorithm>
  36 #include <osg/Math>             // isNaN
  37 #include <plib/netSocket.h>
  38
  39 #include <simgear/misc/stdint.hxx>
  40 #include <simgear/timing/timestamp.hxx>
  41 #include <simgear/debug/logstream.hxx>
  42 #include <simgear/props/props.hxx>
  43
  44 #include <AIModel/AIManager.hxx>
  45 #include <Main/fg_props.hxx>
  46 #include "multiplaymgr.hxx"
  47 #include "mpmessages.hxx"
  48
  49 using std::cerr;
  50
  51 #define MAX_PACKET_SIZE 1200
  52 #define MAX_TEXT_SIZE 128
  53
  54 // These constants are provided so that the ident
  55 // command can list file versions
  56 const char sMULTIPLAYMGR_BID[] = "$Id$";
  57 const char sMULTIPLAYMGR_HID[] = MULTIPLAYTXMGR_HID;
  58
  59 // A static map of protocol property id values to property paths,
  60 // This should be extendable dynamically for every specific aircraft ...
  61 // For now only that static list
  62 FGMultiplayMgr::IdPropertyList
  63 const FGMultiplayMgr::sIdPropertyList[] = {
  64   {100, "surface-positions/left-aileron-pos-norm",  SGPropertyNode::FLOAT},
  65   {101, "surface-positions/right-aileron-pos-norm", SGPropertyNode::FLOAT},
  66   {102, "surface-positions/elevator-pos-norm",      SGPropertyNode::FLOAT},
  67   {103, "surface-positions/rudder-pos-norm",        SGPropertyNode::FLOAT},
  68   {104, "surface-positions/flap-pos-norm",          SGPropertyNode::FLOAT},
  69   {105, "surface-positions/speedbrake-pos-norm",    SGPropertyNode::FLOAT},
  70   {106, "gear/tailhook/position-norm",              SGPropertyNode::FLOAT},
  71   {107, "gear/launchbar/position-norm",             SGPropertyNode::FLOAT},
  72   {108, "gear/launchbar/state",                     SGPropertyNode::STRING},
  73   {109, "gear/launchbar/holdback-position-norm",    SGPropertyNode::FLOAT},
  74   {110, "canopy/position-norm",                     SGPropertyNode::FLOAT},
  75   {111, "surface-positions/wing-pos-norm",          SGPropertyNode::FLOAT},
  76   {112, "surface-positions/wing-fold-pos-norm",     SGPropertyNode::FLOAT},
  77
  78   {200, "gear/gear[0]/compression-norm",           SGPropertyNode::FLOAT},
  79   {201, "gear/gear[0]/position-norm",              SGPropertyNode::FLOAT},
  80   {210, "gear/gear[1]/compression-norm",           SGPropertyNode::FLOAT},
  81   {211, "gear/gear[1]/position-norm",              SGPropertyNode::FLOAT},
  82   {220, "gear/gear[2]/compression-norm",           SGPropertyNode::FLOAT},
  83   {221, "gear/gear[2]/position-norm",              SGPropertyNode::FLOAT},
  84   {230, "gear/gear[3]/compression-norm",           SGPropertyNode::FLOAT},
  85   {231, "gear/gear[3]/position-norm",              SGPropertyNode::FLOAT},
  86   {240, "gear/gear[4]/compression-norm",           SGPropertyNode::FLOAT},
  87   {241, "gear/gear[4]/position-norm",              SGPropertyNode::FLOAT},
  88
  89   {300, "engines/engine[0]/n1",  SGPropertyNode::FLOAT},
  90   {301, "engines/engine[0]/n2",  SGPropertyNode::FLOAT},
  91   {302, "engines/engine[0]/rpm", SGPropertyNode::FLOAT},
  92   {310, "engines/engine[1]/n1",  SGPropertyNode::FLOAT},
  93   {311, "engines/engine[1]/n2",  SGPropertyNode::FLOAT},
  94   {312, "engines/engine[1]/rpm", SGPropertyNode::FLOAT},
  95   {320, "engines/engine[2]/n1",  SGPropertyNode::FLOAT},
  96   {321, "engines/engine[2]/n2",  SGPropertyNode::FLOAT},
  97   {322, "engines/engine[2]/rpm", SGPropertyNode::FLOAT},
  98   {330, "engines/engine[3]/n1",  SGPropertyNode::FLOAT},
  99   {331, "engines/engine[3]/n2",  SGPropertyNode::FLOAT},
 100   {332, "engines/engine[3]/rpm", SGPropertyNode::FLOAT},
 101   {340, "engines/engine[4]/n1",  SGPropertyNode::FLOAT},
 102   {341, "engines/engine[4]/n2",  SGPropertyNode::FLOAT},
 103   {342, "engines/engine[4]/rpm", SGPropertyNode::FLOAT},
 104   {350, "engines/engine[5]/n1",  SGPropertyNode::FLOAT},
 105   {351, "engines/engine[5]/n2",  SGPropertyNode::FLOAT},
 106   {352, "engines/engine[5]/rpm", SGPropertyNode::FLOAT},
 107   {360, "engines/engine[6]/n1",  SGPropertyNode::FLOAT},
 108   {361, "engines/engine[6]/n2",  SGPropertyNode::FLOAT},
 109   {362, "engines/engine[6]/rpm", SGPropertyNode::FLOAT},
 110   {370, "engines/engine[7]/n1",  SGPropertyNode::FLOAT},
 111   {371, "engines/engine[7]/n2",  SGPropertyNode::FLOAT},
 112   {372, "engines/engine[7]/rpm", SGPropertyNode::FLOAT},
 113   {380, "engines/engine[8]/n1",  SGPropertyNode::FLOAT},
 114   {381, "engines/engine[8]/n2",  SGPropertyNode::FLOAT},
 115   {382, "engines/engine[8]/rpm", SGPropertyNode::FLOAT},
 116   {390, "engines/engine[9]/n1",  SGPropertyNode::FLOAT},
 117   {391, "engines/engine[9]/n2",  SGPropertyNode::FLOAT},
 118   {392, "engines/engine[9]/rpm", SGPropertyNode::FLOAT},
 119
 120   {800, "rotors/main/rpm", SGPropertyNode::FLOAT},
 121   {801, "rotors/tail/rpm", SGPropertyNode::FLOAT},
 122   {810, "rotors/main/blade[0]/position-deg",  SGPropertyNode::FLOAT},
 123   {811, "rotors/main/blade[1]/position-deg",  SGPropertyNode::FLOAT},
 124   {812, "rotors/main/blade[2]/position-deg",  SGPropertyNode::FLOAT},
 125   {813, "rotors/main/blade[3]/position-deg",  SGPropertyNode::FLOAT},
 126   {820, "rotors/main/blade[0]/flap-deg",  SGPropertyNode::FLOAT},
 127   {821, "rotors/main/blade[1]/flap-deg",  SGPropertyNode::FLOAT},
 128   {822, "rotors/main/blade[2]/flap-deg",  SGPropertyNode::FLOAT},
 129   {823, "rotors/main/blade[3]/flap-deg",  SGPropertyNode::FLOAT},
 130   {830, "rotors/tail/blade[0]/position-deg",  SGPropertyNode::FLOAT},
 131   {831, "rotors/tail/blade[1]/position-deg",  SGPropertyNode::FLOAT},
 132
 133   {900, "sim/hitches/aerotow/tow/length",                       SGPropertyNode::FLOAT},
 134   {901, "sim/hitches/aerotow/tow/elastic-constant",             SGPropertyNode::FLOAT},
 135   {902, "sim/hitches/aerotow/tow/weight-per-m-kg-m",            SGPropertyNode::FLOAT},
 136   {903, "sim/hitches/aerotow/tow/dist",                         SGPropertyNode::FLOAT},
 137   {904, "sim/hitches/aerotow/tow/connected-to-property-node",   SGPropertyNode::BOOL},
 138   {905, "sim/hitches/aerotow/tow/connected-to-ai-or-mp-callsign",   SGPropertyNode::STRING},
 139   {906, "sim/hitches/aerotow/tow/brake-force",                  SGPropertyNode::FLOAT},
 140   {907, "sim/hitches/aerotow/tow/end-force-x",                  SGPropertyNode::FLOAT},
 141   {908, "sim/hitches/aerotow/tow/end-force-y",                  SGPropertyNode::FLOAT},
 142   {909, "sim/hitches/aerotow/tow/end-force-z",                  SGPropertyNode::FLOAT},
 143   {930, "sim/hitches/aerotow/is-slave",                         SGPropertyNode::BOOL},
 144   {931, "sim/hitches/aerotow/speed-in-tow-direction",           SGPropertyNode::FLOAT},
 145   {932, "sim/hitches/aerotow/open",                             SGPropertyNode::BOOL},
 146   {933, "sim/hitches/aerotow/local-pos-x",                      SGPropertyNode::FLOAT},
 147   {934, "sim/hitches/aerotow/local-pos-y",                      SGPropertyNode::FLOAT},
 148   {935, "sim/hitches/aerotow/local-pos-z",                      SGPropertyNode::FLOAT},
 149
 150   {1001, "controls/flight/slats",  SGPropertyNode::FLOAT},
 151   {1002, "controls/flight/speedbrake",  SGPropertyNode::FLOAT},
 152   {1003, "controls/flight/spoilers",  SGPropertyNode::FLOAT},
 153   {1004, "controls/gear/gear-down",  SGPropertyNode::FLOAT},
 154   {1005, "controls/lighting/nav-lights",  SGPropertyNode::FLOAT},
 155   {1006, "controls/armament/station[0]/jettison-all",  SGPropertyNode::BOOL},
 156
 157   {1100, "sim/model/variant", SGPropertyNode::INT},
 158   {1101, "sim/model/livery/file", SGPropertyNode::STRING},
 159
 160   {1200, "environment/wildfire/data", SGPropertyNode::STRING},
 161
 162   {10001, "sim/multiplay/transmission-freq-hz",  SGPropertyNode::STRING},
 163   {10002, "sim/multiplay/chat",  SGPropertyNode::STRING},
 164
 165   {10100, "sim/multiplay/generic/string[0]", SGPropertyNode::STRING},
 166   {10101, "sim/multiplay/generic/string[1]", SGPropertyNode::STRING},
 167   {10102, "sim/multiplay/generic/string[2]", SGPropertyNode::STRING},
 168   {10103, "sim/multiplay/generic/string[3]", SGPropertyNode::STRING},
 169   {10104, "sim/multiplay/generic/string[4]", SGPropertyNode::STRING},
 170   {10105, "sim/multiplay/generic/string[5]", SGPropertyNode::STRING},
 171   {10106, "sim/multiplay/generic/string[6]", SGPropertyNode::STRING},
 172   {10107, "sim/multiplay/generic/string[7]", SGPropertyNode::STRING},
 173   {10108, "sim/multiplay/generic/string[8]", SGPropertyNode::STRING},
 174   {10109, "sim/multiplay/generic/string[9]", SGPropertyNode::STRING},
 175   {10110, "sim/multiplay/generic/string[10]", SGPropertyNode::STRING},
 176   {10111, "sim/multiplay/generic/string[11]", SGPropertyNode::STRING},
 177   {10112, "sim/multiplay/generic/string[12]", SGPropertyNode::STRING},
 178   {10113, "sim/multiplay/generic/string[13]", SGPropertyNode::STRING},
 179   {10114, "sim/multiplay/generic/string[14]", SGPropertyNode::STRING},
 180   {10115, "sim/multiplay/generic/string[15]", SGPropertyNode::STRING},
 181   {10116, "sim/multiplay/generic/string[16]", SGPropertyNode::STRING},
 182   {10117, "sim/multiplay/generic/string[17]", SGPropertyNode::STRING},
 183   {10118, "sim/multiplay/generic/string[18]", SGPropertyNode::STRING},
 184   {10119, "sim/multiplay/generic/string[19]", SGPropertyNode::STRING},
 185
 186   {10200, "sim/multiplay/generic/float[0]", SGPropertyNode::FLOAT},
 187   {10201, "sim/multiplay/generic/float[1]", SGPropertyNode::FLOAT},
 188   {10202, "sim/multiplay/generic/float[2]", SGPropertyNode::FLOAT},
 189   {10203, "sim/multiplay/generic/float[3]", SGPropertyNode::FLOAT},
 190   {10204, "sim/multiplay/generic/float[4]", SGPropertyNode::FLOAT},
 191   {10205, "sim/multiplay/generic/float[5]", SGPropertyNode::FLOAT},
 192   {10206, "sim/multiplay/generic/float[6]", SGPropertyNode::FLOAT},
 193   {10207, "sim/multiplay/generic/float[7]", SGPropertyNode::FLOAT},
 194   {10208, "sim/multiplay/generic/float[8]", SGPropertyNode::FLOAT},
 195   {10209, "sim/multiplay/generic/float[9]", SGPropertyNode::FLOAT},
 196   {10210, "sim/multiplay/generic/float[10]", SGPropertyNode::FLOAT},
 197   {10211, "sim/multiplay/generic/float[11]", SGPropertyNode::FLOAT},
 198   {10212, "sim/multiplay/generic/float[12]", SGPropertyNode::FLOAT},
 199   {10213, "sim/multiplay/generic/float[13]", SGPropertyNode::FLOAT},
 200   {10214, "sim/multiplay/generic/float[14]", SGPropertyNode::FLOAT},
 201   {10215, "sim/multiplay/generic/float[15]", SGPropertyNode::FLOAT},
 202   {10216, "sim/multiplay/generic/float[16]", SGPropertyNode::FLOAT},
 203   {10217, "sim/multiplay/generic/float[17]", SGPropertyNode::FLOAT},
 204   {10218, "sim/multiplay/generic/float[18]", SGPropertyNode::FLOAT},
 205   {10219, "sim/multiplay/generic/float[19]", SGPropertyNode::FLOAT},
 206
 207   {10300, "sim/multiplay/generic/int[0]", SGPropertyNode::INT},
 208   {10301, "sim/multiplay/generic/int[1]", SGPropertyNode::INT},
 209   {10302, "sim/multiplay/generic/int[2]", SGPropertyNode::INT},
 210   {10303, "sim/multiplay/generic/int[3]", SGPropertyNode::INT},
 211   {10304, "sim/multiplay/generic/int[4]", SGPropertyNode::INT},
 212   {10305, "sim/multiplay/generic/int[5]", SGPropertyNode::INT},
 213   {10306, "sim/multiplay/generic/int[6]", SGPropertyNode::INT},
 214   {10307, "sim/multiplay/generic/int[7]", SGPropertyNode::INT},
 215   {10308, "sim/multiplay/generic/int[8]", SGPropertyNode::INT},
 216   {10309, "sim/multiplay/generic/int[9]", SGPropertyNode::INT},
 217   {10310, "sim/multiplay/generic/int[10]", SGPropertyNode::INT},
 218   {10311, "sim/multiplay/generic/int[11]", SGPropertyNode::INT},
 219   {10312, "sim/multiplay/generic/int[12]", SGPropertyNode::INT},
 220   {10313, "sim/multiplay/generic/int[13]", SGPropertyNode::INT},
 221   {10314, "sim/multiplay/generic/int[14]", SGPropertyNode::INT},
 222   {10315, "sim/multiplay/generic/int[15]", SGPropertyNode::INT},
 223   {10316, "sim/multiplay/generic/int[16]", SGPropertyNode::INT},
 224   {10317, "sim/multiplay/generic/int[17]", SGPropertyNode::INT},
 225   {10318, "sim/multiplay/generic/int[18]", SGPropertyNode::INT},
 226   {10319, "sim/multiplay/generic/int[19]", SGPropertyNode::INT},
 227 };
 228
 229 const unsigned
 230 FGMultiplayMgr::numProperties = (sizeof(FGMultiplayMgr::sIdPropertyList)
 231                                  / sizeof(FGMultiplayMgr::sIdPropertyList[0]));
 232
 233 // Look up a property ID using binary search.
 234 namespace
 235 {
 236   struct ComparePropertyId
 237   {
 238     bool operator()(const FGMultiplayMgr::IdPropertyList& lhs,
 239                     const FGMultiplayMgr::IdPropertyList& rhs)
 240     {
 241       return lhs.id < rhs.id;
 242     }
 243     bool operator()(const FGMultiplayMgr::IdPropertyList& lhs,
 244                     unsigned id)
 245     {
 246       return lhs.id < id;
 247     }
 248     bool operator()(unsigned id,
 249                     const FGMultiplayMgr::IdPropertyList& rhs)
 250     {
 251       return id < rhs.id;
 252     }
 253   };
 254
 255 }
 256 const FGMultiplayMgr::IdPropertyList* FGMultiplayMgr::findProperty(unsigned id)
 257 {
 258   std::pair<const IdPropertyList*, const IdPropertyList*> result
 259     = std::equal_range(sIdPropertyList, sIdPropertyList + numProperties, id,
 260                        ComparePropertyId());
 261   if (result.first == result.second) {
 262     return 0;
 263   } else {
 264     return result.first;
 265   }
 266 }
 267
 268 namespace
 269 {
 270   bool verifyProperties(const xdr_data_t* data, const xdr_data_t* end)
 271   {
 272     const xdr_data_t* xdr = data;
 273     while (xdr < end) {
 274       unsigned id = XDR_decode_uint32(*xdr);
 275       const FGMultiplayMgr::IdPropertyList* plist
 276         = FGMultiplayMgr::findProperty(id);
 277
 278       if (plist) {
 279         xdr++;
 280         // How we decode the remainder of the property depends on the type
 281         switch (plist->type) {
 282         case SGPropertyNode::INT:
 283         case SGPropertyNode::BOOL:
 284         case SGPropertyNode::LONG:
 285           xdr++;
 286           break;
 287         case SGPropertyNode::FLOAT:
 288         case SGPropertyNode::DOUBLE:
 289           {
 290             float val = XDR_decode_float(*xdr);
 291             if (osg::isNaN(val))
 292               return false;
 293             xdr++;
 294             break;
 295           }
 296         case SGPropertyNode::STRING:
 297         case SGPropertyNode::UNSPECIFIED:
 298           {
 299             // String is complicated. It consists of
 300             // The length of the string
 301             // The string itself
 302             // Padding to the nearest 4-bytes.
 303             // XXX Yes, each byte is padded out to a word! Too late
 304             // to change...
 305             uint32_t length = XDR_decode_uint32(*xdr);
 306             xdr++;
 307             if ((length > 0) && (length < MAX_TEXT_SIZE)) {
 308               xdr += length;
 309               // Now handle the padding
 310               while ((length % 4) != 0)
 311                 {
 312                   xdr++;
 313                   length++;
 314                   //cout << "0";
 315                 }
 316             } else {
 317               // The string appears to be invalid; bail.
 318               return false;
 319             }
 320           }
 321           break;
 322         default:
 323           // cerr << "Unknown Prop type " << id << " " << type << "\n";
 324           xdr++;
 325           break;
 326         }
 327       }
 328       else {
 329         // give up; this is a malformed property list.
 330         return false;
 331       }
 332     }
 333     return true;
 334   }
 335 }
 336 //////////////////////////////////////////////////////////////////////
 337 //
 338 //  MultiplayMgr constructor
 339 //
 340 //////////////////////////////////////////////////////////////////////
 341 FGMultiplayMgr::FGMultiplayMgr()
 342 {
 343   mSocket        = 0;
 344   mInitialised   = false;
 345   mHaveServer    = false;
 346 } // FGMultiplayMgr::FGMultiplayMgr()
 347 //////////////////////////////////////////////////////////////////////
 348
 349 //////////////////////////////////////////////////////////////////////
 350 //
 351 //  MultiplayMgr destructor
 352 //
 353 //////////////////////////////////////////////////////////////////////
 354 FGMultiplayMgr::~FGMultiplayMgr()
 355 {
 356   Close();
 357 } // FGMultiplayMgr::~FGMultiplayMgr()
 358 //////////////////////////////////////////////////////////////////////
 359
 360 //////////////////////////////////////////////////////////////////////
 361 //
 362 //  Initialise object
 363 //
 364 //////////////////////////////////////////////////////////////////////
 365 bool
 366 FGMultiplayMgr::init (void)
 367 {
 368   //////////////////////////////////////////////////
 369   //  Initialise object if not already done
 370   //////////////////////////////////////////////////
 371   if (mInitialised) {
 372     SG_LOG(SG_NETWORK, SG_WARN, "FGMultiplayMgr::init - already initialised");
 373     return false;
 374   }
 375   //////////////////////////////////////////////////
 376   //  Set members from property values
 377   //////////////////////////////////////////////////
 378   short rxPort = fgGetInt("/sim/multiplay/rxport");
 379   string rxAddress = fgGetString("/sim/multiplay/rxhost");
 380   short txPort = fgGetInt("/sim/multiplay/txport");
 381   string txAddress = fgGetString("/sim/multiplay/txhost");
 382   mCallsign = fgGetString("/sim/multiplay/callsign");
 383   if (txPort > 0 && !txAddress.empty()) {
 384     mServer.set(txAddress.c_str(), txPort);
 385     if (strncmp (mServer.getHost(), "0.0.0.0", 8) == 0) {
 386       mHaveServer = false;
 387       SG_LOG(SG_NETWORK, SG_ALERT,
 388         "FGMultiplayMgr - could not resolve '"
 389         << txAddress << "', Multiplayermode disabled");
 390     } else {
 391       mHaveServer = true;
 392     }
 393     if (rxPort <= 0)
 394       rxPort = txPort;
 395   }
 396   if (rxPort <= 0) {
 397     SG_LOG(SG_NETWORK, SG_ALERT,
 398       "FGMultiplayMgr - No receiver port, Multiplayermode disabled");
 399     return (false);
 400   }
 401   if (mCallsign.empty())
 402     mCallsign = "JohnDoe"; // FIXME: use getpwuid
 403   SG_LOG(SG_NETWORK,SG_INFO,"FGMultiplayMgr::init-txaddress= "<<txAddress);
 404   SG_LOG(SG_NETWORK,SG_INFO,"FGMultiplayMgr::init-txport= "<<txPort );
 405   SG_LOG(SG_NETWORK,SG_INFO,"FGMultiplayMgr::init-rxaddress="<<rxAddress );
 406   SG_LOG(SG_NETWORK,SG_INFO,"FGMultiplayMgr::init-rxport= "<<rxPort);
 407   SG_LOG(SG_NETWORK,SG_INFO,"FGMultiplayMgr::init-callsign= "<<mCallsign);
 408   Close(); // Should Init be called twice, close Socket first
 409            // A memory leak was reported here by valgrind
 410   mSocket = new netSocket();
 411   if (!mSocket->open(false)) {
 412     SG_LOG( SG_NETWORK, SG_ALERT,
 413             "FGMultiplayMgr::init - Failed to create data socket" );
 414     return false;
 415   }
 416   mSocket->setBlocking(false);
 417   if (mSocket->bind(rxAddress.c_str(), rxPort) != 0) {
 418     perror("bind");
 419     SG_LOG( SG_NETWORK, SG_ALERT,
 420             "FGMultiplayMgr::Open - Failed to bind receive socket" );
 421     return false;
 422   }
 423   mInitialised = true;
 424   return true;
 425 } // FGMultiplayMgr::init()
 426 //////////////////////////////////////////////////////////////////////
 427
 428 //////////////////////////////////////////////////////////////////////
 429 //
 430 //  Closes and deletes the local player object. Closes
 431 //  and deletes the tx socket. Resets the object state to unitialised.
 432 //
 433 //////////////////////////////////////////////////////////////////////
 434 void
 435 FGMultiplayMgr::Close (void)
 436 {
 437   mMultiPlayerMap.clear();
 438
 439   if (mSocket) {
 440     mSocket->close();
 441     delete mSocket;
 442     mSocket = 0;
 443   }
 444   mInitialised = false;
 445 } // FGMultiplayMgr::Close(void)
 446 //////////////////////////////////////////////////////////////////////
 447
 448 //////////////////////////////////////////////////////////////////////
 449 //
 450 //  Description: Sends the position data for the local position.
 451 //
 452 //////////////////////////////////////////////////////////////////////
 453 void
 454 FGMultiplayMgr::SendMyPosition(const FGExternalMotionData& motionInfo)
 455 {
 456   if ((! mInitialised) || (! mHaveServer))
 457         return;
 458   if (! mHaveServer) {
 459     SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::SendMyPosition - no server");
 460     return;
 461   }
 462
 463   T_PositionMsg PosMsg;
 464
 465   memset(&PosMsg, 0, sizeof(PosMsg));
 466   strncpy(PosMsg.Model, fgGetString("/sim/model/path"), MAX_MODEL_NAME_LEN);
 467   PosMsg.Model[MAX_MODEL_NAME_LEN - 1] = '\0';
 468
 469   PosMsg.time = XDR_encode_double (motionInfo.time);
 470   PosMsg.lag = XDR_encode_double (motionInfo.lag);
 471   for (unsigned i = 0 ; i < 3; ++i)
 472     PosMsg.position[i] = XDR_encode_double (motionInfo.position(i));
 473   SGVec3f angleAxis;
 474   motionInfo.orientation.getAngleAxis(angleAxis);
 475   for (unsigned i = 0 ; i < 3; ++i)
 476     PosMsg.orientation[i] = XDR_encode_float (angleAxis(i));
 477   for (unsigned i = 0 ; i < 3; ++i)
 478     PosMsg.linearVel[i] = XDR_encode_float (motionInfo.linearVel(i));
 479   for (unsigned i = 0 ; i < 3; ++i)
 480     PosMsg.angularVel[i] = XDR_encode_float (motionInfo.angularVel(i));
 481   for (unsigned i = 0 ; i < 3; ++i)
 482     PosMsg.linearAccel[i] = XDR_encode_float (motionInfo.linearAccel(i));
 483   for (unsigned i = 0 ; i < 3; ++i)
 484     PosMsg.angularAccel[i] = XDR_encode_float (motionInfo.angularAccel(i));
 485
 486   char Msg[MAX_PACKET_SIZE];
 487   memcpy(Msg + sizeof(T_MsgHdr), &PosMsg, sizeof(T_PositionMsg));
 488
 489   char* ptr = Msg + sizeof(T_MsgHdr) + sizeof(T_PositionMsg);
 490   std::vector<FGPropertyData*>::const_iterator it;
 491   it = motionInfo.properties.begin();
 492   //cout << "OUTPUT PROPERTIES\n";
 493   while (it != motionInfo.properties.end()
 494          && ptr + 2 * sizeof(xdr_data_t) < (Msg + MAX_PACKET_SIZE)) {
 495
 496     // First elements is the ID
 497     xdr_data_t xdr = XDR_encode_uint32((*it)->id);
 498     memcpy(ptr, &xdr, sizeof(xdr_data_t));
 499     ptr += sizeof(xdr_data_t);
 500
 501     // The actual data representation depends on the type
 502     switch ((*it)->type) {
 503       case SGPropertyNode::INT:
 504       case SGPropertyNode::BOOL:
 505       case SGPropertyNode::LONG:
 506         xdr = XDR_encode_uint32((*it)->int_value);
 507         memcpy(ptr, &xdr, sizeof(xdr_data_t));
 508         ptr += sizeof(xdr_data_t);
 509         //cout << "Prop:" << (*it)->id << " " << (*it)->type << " "<< (*it)->int_value << "\n";
 510         break;
 511       case SGPropertyNode::FLOAT:
 512       case SGPropertyNode::DOUBLE:
 513         xdr = XDR_encode_float((*it)->float_value);;
 514         memcpy(ptr, &xdr, sizeof(xdr_data_t));
 515         ptr += sizeof(xdr_data_t);
 516         //cout << "Prop:" << (*it)->id << " " << (*it)->type << " "<< (*it)->float_value << "\n";
 517         break;
 518       case SGPropertyNode::STRING:
 519       case SGPropertyNode::UNSPECIFIED:
 520         {
 521           // String is complicated. It consists of
 522           // The length of the string
 523           // The string itself
 524           // Padding to the nearest 4-bytes.
 525           const char* lcharptr = (*it)->string_value;
 526
 527           if (lcharptr != 0)
 528           {
 529             // Add the length
 530             ////cout << "String length: " << strlen(lcharptr) << "\n";
 531             uint32_t len = strlen(lcharptr);
 532             // XXX This should not be using 4 bytes per character!
 533             if (ptr + (1 + len + (4 - len % 4)) * sizeof (xdr_data_t)
 534                 >= (Msg + MAX_PACKET_SIZE))
 535                 goto escape;
 536             //cout << "String length unint32: " << len << "\n";
 537             xdr = XDR_encode_uint32(len);
 538             memcpy(ptr, &xdr, sizeof(xdr_data_t));
 539             ptr += sizeof(xdr_data_t);
 540
 541             if (len != 0)
 542             {
 543
 544               // Now the text itself
 545               // XXX This should not be using 4 bytes per character!
 546               int lcount = 0;
 547               while ((*lcharptr != '\0') && (lcount < MAX_TEXT_SIZE))
 548               {
 549                 xdr = XDR_encode_int8(*lcharptr);
 550                 memcpy(ptr, &xdr, sizeof(xdr_data_t));
 551                 ptr += sizeof(xdr_data_t);
 552                 lcharptr++;
 553                 lcount++;
 554               }
 555
 556               //cout << "Prop:" << (*it)->id << " " << (*it)->type << " " << len << " " << (*it)->string_value;
 557
 558               // Now pad if required
 559               while ((lcount % 4) != 0)
 560               {
 561                 xdr = XDR_encode_int8(0);
 562                 memcpy(ptr, &xdr, sizeof(xdr_data_t));
 563                 ptr += sizeof(xdr_data_t);
 564                 lcount++;
 565                 //cout << "0";
 566               }
 567
 568               //cout << "\n";
 569             }
 570           }
 571           else
 572           {
 573             // Nothing to encode
 574             xdr = XDR_encode_uint32(0);
 575             memcpy(ptr, &xdr, sizeof(xdr_data_t));
 576             ptr += sizeof(xdr_data_t);
 577             //cout << "Prop:" << (*it)->id << " " << (*it)->type << " 0\n";
 578           }
 579
 580         }
 581         break;
 582
 583       default:
 584         //cout << " Unknown Type: " << (*it)->type << "\n";
 585         xdr = XDR_encode_float((*it)->float_value);;
 586         memcpy(ptr, &xdr, sizeof(xdr_data_t));
 587         ptr += sizeof(xdr_data_t);
 588         //cout << "Prop:" << (*it)->id << " " << (*it)->type << " "<< (*it)->float_value << "\n";
 589         break;
 590     }
 591
 592     ++it;
 593   }
 594 escape:
 595
 596   T_MsgHdr MsgHdr;
 597   FillMsgHdr(&MsgHdr, POS_DATA_ID, ptr - Msg);
 598   memcpy(Msg, &MsgHdr, sizeof(T_MsgHdr));
 599
 600   mSocket->sendto(Msg, ptr - Msg, 0, &mServer);
 601   SG_LOG(SG_NETWORK, SG_DEBUG, "FGMultiplayMgr::SendMyPosition");
 602 } // FGMultiplayMgr::SendMyPosition()
 603 //////////////////////////////////////////////////////////////////////
 604
 605 //////////////////////////////////////////////////////////////////////
 606 //
 607 //  Name: SendTextMessage
 608 //  Description: Sends a message to the player. The message must
 609 //  contain a valid and correctly filled out header and optional
 610 //  message body.
 611 //
 612 //////////////////////////////////////////////////////////////////////
 613 void
 614 FGMultiplayMgr::SendTextMessage(const string &MsgText)
 615 {
 616   if (!mInitialised || !mHaveServer)
 617     return;
 618
 619   T_MsgHdr MsgHdr;
 620   FillMsgHdr(&MsgHdr, CHAT_MSG_ID);
 621   //////////////////////////////////////////////////
 622   // Divide the text string into blocks that fit
 623   // in the message and send the blocks.
 624   //////////////////////////////////////////////////
 625   unsigned iNextBlockPosition = 0;
 626   T_ChatMsg ChatMsg;
 627
 628   char Msg[sizeof(T_MsgHdr) + sizeof(T_ChatMsg)];
 629   while (iNextBlockPosition < MsgText.length()) {
 630     strncpy (ChatMsg.Text,
 631              MsgText.substr(iNextBlockPosition, MAX_CHAT_MSG_LEN - 1).c_str(),
 632              MAX_CHAT_MSG_LEN);
 633     ChatMsg.Text[MAX_CHAT_MSG_LEN - 1] = '\0';
 634     memcpy (Msg, &MsgHdr, sizeof(T_MsgHdr));
 635     memcpy (Msg + sizeof(T_MsgHdr), &ChatMsg, sizeof(T_ChatMsg));
 636     mSocket->sendto (Msg, sizeof(T_MsgHdr) + sizeof(T_ChatMsg), 0, &mServer);
 637     iNextBlockPosition += MAX_CHAT_MSG_LEN - 1;
 638
 639   }
 640
 641
 642 } // FGMultiplayMgr::SendTextMessage ()
 643 //////////////////////////////////////////////////////////////////////
 644
 645 //////////////////////////////////////////////////////////////////////
 646 //
 647 //  Name: ProcessData
 648 //  Description: Processes data waiting at the receive socket. The
 649 //  processing ends when there is no more data at the socket.
 650 //
 651 //////////////////////////////////////////////////////////////////////
 652 void
 653 FGMultiplayMgr::Update(void)
 654 {
 655   if (!mInitialised)
 656     return;
 657
 658   /// Just for expiry
 659   SGTimeStamp timestamper;
 660   timestamper.stamp();
 661   long stamp = timestamper.get_seconds();
 662
 663   //////////////////////////////////////////////////
 664   //  Read the receive socket and process any data
 665   //////////////////////////////////////////////////
 666   int bytes;
 667   do {
 668     char Msg[MAX_PACKET_SIZE];
 669     //////////////////////////////////////////////////
 670     //  Although the recv call asks for
 671     //  MAX_PACKET_SIZE of data, the number of bytes
 672     //  returned will only be that of the next
 673     //  packet waiting to be processed.
 674     //////////////////////////////////////////////////
 675     netAddress SenderAddress;
 676     bytes = mSocket->recvfrom(Msg, sizeof(Msg), 0, &SenderAddress);
 677     //////////////////////////////////////////////////
 678     //  no Data received
 679     //////////////////////////////////////////////////
 680     if (bytes <= 0) {
 681       if (errno != EAGAIN && errno != 0) // MSVC output "NoError" otherwise
 682         perror("FGMultiplayMgr::MP_ProcessData");
 683       break;
 684     }
 685     if (bytes <= sizeof(T_MsgHdr)) {
 686       SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
 687               << "received message with insufficient data" );
 688       break;
 689     }
 690     //////////////////////////////////////////////////
 691     //  Read header
 692     //////////////////////////////////////////////////
 693     T_MsgHdr* MsgHdr = (T_MsgHdr *)Msg;
 694     MsgHdr->Magic       = XDR_decode_uint32 (MsgHdr->Magic);
 695     MsgHdr->Version     = XDR_decode_uint32 (MsgHdr->Version);
 696     MsgHdr->MsgId       = XDR_decode_uint32 (MsgHdr->MsgId);
 697     MsgHdr->MsgLen      = XDR_decode_uint32 (MsgHdr->MsgLen);
 698     MsgHdr->ReplyPort   = XDR_decode_uint32 (MsgHdr->ReplyPort);
 699     if (MsgHdr->Magic != MSG_MAGIC) {
 700       SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
 701               << "message has invalid magic number!" );
 702       break;
 703     }
 704     if (MsgHdr->Version != PROTO_VER) {
 705       SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
 706               << "message has invalid protocoll number!" );
 707       break;
 708     }
 709     if (MsgHdr->MsgLen != bytes) {
 710       SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
 711               << "message has invalid length!" );
 712       break;
 713     }
 714     //////////////////////////////////////////////////
 715     //  Process messages
 716     //////////////////////////////////////////////////
 717     switch (MsgHdr->MsgId) {
 718     case CHAT_MSG_ID:
 719       ProcessChatMsg(Msg, SenderAddress);
 720       break;
 721     case POS_DATA_ID:
 722       ProcessPosMsg(Msg, SenderAddress, bytes, stamp);
 723       break;
 724     case UNUSABLE_POS_DATA_ID:
 725     case OLD_OLD_POS_DATA_ID:
 726     case OLD_PROP_MSG_ID:
 727     case OLD_POS_DATA_ID:
 728       break;
 729     default:
 730       SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
 731               << "Unknown message Id received: " << MsgHdr->MsgId );
 732       break;
 733     }
 734   } while (bytes > 0);
 735
 736   // check for expiry
 737   MultiPlayerMap::iterator it = mMultiPlayerMap.begin();
 738   while (it != mMultiPlayerMap.end()) {
 739     if (it->second->getLastTimestamp() + 10 < stamp) {
 740       std::string name = it->first;
 741       it->second->setDie(true);
 742       mMultiPlayerMap.erase(it);
 743       it = mMultiPlayerMap.upper_bound(name);
 744     } else
 745       ++it;
 746   }
 747 } // FGMultiplayMgr::ProcessData(void)
 748 //////////////////////////////////////////////////////////////////////
 749
 750 //////////////////////////////////////////////////////////////////////
 751 //
 752 //  handle a position message
 753 //
 754 //////////////////////////////////////////////////////////////////////
 755 void
 756 FGMultiplayMgr::ProcessPosMsg(const char *Msg, netAddress & SenderAddress,
 757                               unsigned len, long stamp)
 758 {
 759   T_MsgHdr* MsgHdr = (T_MsgHdr *)Msg;
 760   if (MsgHdr->MsgLen < sizeof(T_MsgHdr) + sizeof(T_PositionMsg)) {
 761     SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
 762             << "Position message received with insufficient data" );
 763     return;
 764   }
 765   T_PositionMsg* PosMsg = (T_PositionMsg *)(Msg + sizeof(T_MsgHdr));
 766   FGExternalMotionData motionInfo;
 767   motionInfo.time = XDR_decode_double(PosMsg->time);
 768   motionInfo.lag = XDR_decode_double(PosMsg->lag);
 769   for (unsigned i = 0; i < 3; ++i)
 770     motionInfo.position(i) = XDR_decode_double(PosMsg->position[i]);
 771   SGVec3f angleAxis;
 772   for (unsigned i = 0; i < 3; ++i)
 773     angleAxis(i) = XDR_decode_float(PosMsg->orientation[i]);
 774   motionInfo.orientation = SGQuatf::fromAngleAxis(angleAxis);
 775   for (unsigned i = 0; i < 3; ++i)
 776     motionInfo.linearVel(i) = XDR_decode_float(PosMsg->linearVel[i]);
 777   for (unsigned i = 0; i < 3; ++i)
 778     motionInfo.angularVel(i) = XDR_decode_float(PosMsg->angularVel[i]);
 779   for (unsigned i = 0; i < 3; ++i)
 780     motionInfo.linearAccel(i) = XDR_decode_float(PosMsg->linearAccel[i]);
 781   for (unsigned i = 0; i < 3; ++i)
 782     motionInfo.angularAccel(i) = XDR_decode_float(PosMsg->angularAccel[i]);
 783
 784
 785   //cout << "INPUT MESSAGE\n";
 786   xdr_data_t* xdr = (xdr_data_t*)
 787                    (Msg + sizeof(T_MsgHdr) + sizeof(T_PositionMsg));
 788   // There was a bug in 1.9.0 and before: T_PositionMsg was 196 bytes
 789   // on 32 bit architectures and 200 bytes on 64 bit, and this
 790   // structure is put directly on the wire. By looking at the padding,
 791   // we can sort through the mess, mostly:
 792   // If padding is 0 (which is not a valid property type), then the
 793   // message was produced by a new client or an old 64 bit client that
 794   // happened to have 0 on the stack;
 795   // Else if the property list starting with the padding word is
 796   // well-formed, then the client is probably an old 32 bit client and
 797   // we'll go with that;
 798   // Else it is an old 64-bit client and properties start after the
 799   // padding.
 800   // There is a chance that we could be fooled by garbage in the
 801   // padding looking like a valid property, so verifyProperties() is
 802   // strict about the validity of the property values.
 803   if (PosMsg->pad != 0) {
 804     if (verifyProperties(&PosMsg->pad,
 805                          reinterpret_cast<const xdr_data_t*>(Msg + len)))
 806       xdr = &PosMsg->pad;
 807     else if (!verifyProperties(xdr,
 808                                reinterpret_cast<const xdr_data_t*>(Msg + len)))
 809       goto noprops;
 810   }
 811   while ((char*)xdr < Msg + len) {
 812     FGPropertyData* pData = new FGPropertyData;
 813     SGPropertyNode::Type type = SGPropertyNode::UNSPECIFIED;
 814
 815     // First element is always the ID
 816     pData->id = XDR_decode_uint32(*xdr);
 817     //cout << pData->id << " ";
 818     xdr++;
 819
 820     // Check the ID actually exists and get the type
 821     const IdPropertyList* plist = findProperty(pData->id);
 822
 823     if (plist)
 824     {
 825       pData->type = plist->type;
 826       // How we decode the remainder of the property depends on the type
 827       switch (pData->type) {
 828         case SGPropertyNode::INT:
 829         case SGPropertyNode::BOOL:
 830         case SGPropertyNode::LONG:
 831           pData->int_value = XDR_decode_uint32(*xdr);
 832           xdr++;
 833           //cout << pData->int_value << "\n";
 834           break;
 835         case SGPropertyNode::FLOAT:
 836         case SGPropertyNode::DOUBLE:
 837           pData->float_value = XDR_decode_float(*xdr);
 838           xdr++;
 839           //cout << pData->float_value << "\n";
 840           break;
 841         case SGPropertyNode::STRING:
 842         case SGPropertyNode::UNSPECIFIED:
 843           {
 844             // String is complicated. It consists of
 845             // The length of the string
 846             // The string itself
 847             // Padding to the nearest 4-bytes.
 848             uint32_t length = XDR_decode_uint32(*xdr);
 849             xdr++;
 850             //cout << length << " ";
 851
 852             if ((length > 0) && (length < MAX_TEXT_SIZE))
 853             {
 854               pData->string_value = new char[length + 1];
 855               //cout << " String: ";
 856
 857               for (int i = 0; i < length; i++)
 858               {
 859                 pData->string_value[i] = (char) XDR_decode_int8(*xdr);
 860                 xdr++;
 861                 //cout << pData->string_value[i];
 862               }
 863
 864               pData->string_value[length] = '\0';
 865
 866               // Now handle the padding
 867               while ((length % 4) != 0)
 868               {
 869                 xdr++;
 870                 length++;
 871                 //cout << "0";
 872               }
 873             }
 874             else
 875             {
 876               pData->string_value = new char[1];
 877               pData->string_value[0] = '\0';
 878             }
 879
 880             //cout << "\n";
 881           }
 882           break;
 883
 884         default:
 885           pData->float_value = XDR_decode_float(*xdr);
 886           cerr << "Unknown Prop type " << pData->id << " " << pData->type << "\n";
 887           xdr++;
 888           break;
 889       }
 890
 891       motionInfo.properties.push_back(pData);
 892     }
 893     else
 894     {
 895       // We failed to find the property. We'll try the next packet immediately.
 896       SG_LOG(SG_NETWORK, SG_WARN, "FGMultiplayMgr::ProcessPosMsg - "
 897              << "found unknown property id" << pData->id);
 898     }
 899   }
 900  noprops:
 901   FGAIMultiplayer* mp = getMultiplayer(MsgHdr->Callsign);
 902   if (!mp)
 903     mp = addMultiplayer(MsgHdr->Callsign, PosMsg->Model);
 904   mp->addMotionInfo(motionInfo, stamp);
 905 } // FGMultiplayMgr::ProcessPosMsg()
 906 //////////////////////////////////////////////////////////////////////
 907
 908 //////////////////////////////////////////////////////////////////////
 909 //
 910 //  handle a chat message
 911 //  FIXME: display chat message withi flightgear
 912 //
 913 //////////////////////////////////////////////////////////////////////
 914 void
 915 FGMultiplayMgr::ProcessChatMsg(const char *Msg, netAddress& SenderAddress)
 916 {
 917   T_MsgHdr* MsgHdr = (T_MsgHdr *)Msg;
 918   if (MsgHdr->MsgLen < sizeof(T_MsgHdr) + 1) {
 919     SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
 920             << "Chat message received with insufficient data" );
 921     return;
 922   }
 923
 924   char *MsgBuf = new char[MsgHdr->MsgLen - sizeof(T_MsgHdr)];
 925   strncpy(MsgBuf, ((T_ChatMsg *)(Msg + sizeof(T_MsgHdr)))->Text,
 926           MsgHdr->MsgLen - sizeof(T_MsgHdr));
 927   MsgBuf[MsgHdr->MsgLen - sizeof(T_MsgHdr) - 1] = '\0';
 928
 929   T_ChatMsg* ChatMsg = (T_ChatMsg *)(Msg + sizeof(T_MsgHdr));
 930   SG_LOG (SG_NETWORK, SG_ALERT, "Chat [" << MsgHdr->Callsign << "]"
 931            << " " << MsgBuf);
 932
 933   delete [] MsgBuf;
 934 } // FGMultiplayMgr::ProcessChatMsg ()
 935 //////////////////////////////////////////////////////////////////////
 936
 937 void
 938 FGMultiplayMgr::FillMsgHdr(T_MsgHdr *MsgHdr, int MsgId, unsigned _len)
 939 {
 940   uint32_t len;
 941   switch (MsgId) {
 942   case CHAT_MSG_ID:
 943     len = sizeof(T_MsgHdr) + sizeof(T_ChatMsg);
 944     break;
 945   case POS_DATA_ID:
 946     len = _len;
 947     break;
 948   default:
 949     len = sizeof(T_MsgHdr);
 950     break;
 951   }
 952   MsgHdr->Magic           = XDR_encode_uint32(MSG_MAGIC);
 953   MsgHdr->Version         = XDR_encode_uint32(PROTO_VER);
 954   MsgHdr->MsgId           = XDR_encode_uint32(MsgId);
 955   MsgHdr->MsgLen          = XDR_encode_uint32(len);
 956   MsgHdr->ReplyAddress    = 0; // Are obsolete, keep them for the server for
 957   MsgHdr->ReplyPort       = 0; // now
 958   strncpy(MsgHdr->Callsign, mCallsign.c_str(), MAX_CALLSIGN_LEN);
 959   MsgHdr->Callsign[MAX_CALLSIGN_LEN - 1] = '\0';
 960 }
 961
 962 FGAIMultiplayer*
 963 FGMultiplayMgr::addMultiplayer(const std::string& callsign,
 964                                const std::string& modelName)
 965 {
 966   if (0 < mMultiPlayerMap.count(callsign))
 967     return mMultiPlayerMap[callsign].get();
 968
 969   FGAIMultiplayer* mp = new FGAIMultiplayer;
 970   mp->setPath(modelName.c_str());
 971   mp->setCallSign(callsign);
 972   mMultiPlayerMap[callsign] = mp;
 973
 974   FGAIManager *aiMgr = (FGAIManager*)globals->get_subsystem("ai_model");
 975   if (aiMgr) {
 976     aiMgr->attach(mp);
 977
 978     /// FIXME: that must follow the attach ATM ...
 979     for (unsigned i = 0; i < numProperties; ++i)
 980       mp->addPropertyId(sIdPropertyList[i].id, sIdPropertyList[i].name);
 981   }
 982
 983   return mp;
 984 }
 985
 986 FGAIMultiplayer*
 987 FGMultiplayMgr::getMultiplayer(const std::string& callsign)
 988 {
 989   if (0 < mMultiPlayerMap.count(callsign))
 990     return mMultiPlayerMap[callsign].get();
 991   else
 992     return 0;
 993 }