src/network.c

   1 /***********************************************************
   2 * Rocks'n'Diamonds -- McDuffin Strikes Back!               *
   3 *----------------------------------------------------------*
   4 * (c) 1995-2006 Artsoft Entertainment                      *
   5 *               Holger Schemel                             *
   6 *               Detmolder Strasse 189                      *
   7 *               33604 Bielefeld                            *
   8 *               Germany                                    *
   9 *               e-mail: info@artsoft.org                   *
  10 *----------------------------------------------------------*
  11 * network.c                                                *
  12 ***********************************************************/
  13
  14 #include "libgame/platform.h"
  15
  16 #if defined(NETWORK_AVALIABLE)
  17
  18 #include <signal.h>
  19 #include <sys/time.h>
  20
  21 #if defined(TARGET_SDL)
  22 #include "main.h"
  23 #else
  24 #include <sys/wait.h>
  25 #include <sys/socket.h>
  26 #include <netinet/in.h>
  27 #include <netinet/tcp.h>
  28 #include <arpa/inet.h>
  29 #include <netdb.h>
  30 #endif
  31
  32 #include "libgame/libgame.h"
  33
  34 #include "network.h"
  35 #include "netserv.h"
  36 #include "game.h"
  37 #include "tape.h"
  38 #include "files.h"
  39 #include "tools.h"
  40 #include "screens.h"
  41
  42 struct NetworkClientPlayerInfo
  43 {
  44   byte nr;
  45   char name[MAX_PLAYER_NAME_LEN + 1];
  46   struct NetworkClientPlayerInfo *next;
  47 };
  48
  49 static struct NetworkClientPlayerInfo first_player =
  50 {
  51   0,
  52   EMPTY_PLAYER_NAME,
  53   NULL
  54 };
  55
  56 /* server stuff */
  57
  58 #if defined(TARGET_SDL)
  59 static TCPsocket sfd;           /* server socket */
  60 static SDLNet_SocketSet rfds;   /* socket set */
  61 #else
  62 static int sfd;                 /* server socket */
  63 #endif
  64
  65 static byte realbuffer[512];
  66 static byte readbuffer[MAX_BUFFER_SIZE], writbuffer[MAX_BUFFER_SIZE];
  67 static byte *buffer = realbuffer + 4;
  68 static int nread = 0, nwrite = 0;
  69 static boolean stop_network_game = FALSE;
  70
  71 static void SendBufferToServer(int size)
  72 {
  73   if (!options.network)
  74     return;
  75
  76   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  77   realbuffer[3] = (byte)size;
  78   buffer[0] = 0;
  79
  80   if (nwrite + 4 + size >= MAX_BUFFER_SIZE)
  81     Error(ERR_EXIT, "internal error: network send buffer overflow");
  82
  83   memcpy(writbuffer + nwrite, realbuffer, 4 + size);
  84   nwrite += 4 + size;
  85
  86   /* directly send the buffer to the network server */
  87 #if defined(TARGET_SDL)
  88   SDLNet_TCP_Send(sfd, writbuffer, nwrite);
  89 #else
  90   if (write(sfd, writbuffer, nwrite) == -1)
  91     Error(ERR_WARN, "write() failed; %s", strerror(errno));
  92 #endif
  93   nwrite = 0;
  94 }
  95
  96 struct NetworkClientPlayerInfo *getNetworkPlayer(int player_nr)
  97 {
  98   struct NetworkClientPlayerInfo *player = NULL;
  99
 100   for (player = &first_player; player; player = player->next)
 101     if (player->nr == player_nr)
 102       break;
 103
 104   if (player == NULL)   /* should not happen */
 105     Error(ERR_EXIT, "protocol error: reference to non-existing player %d",
 106           player_nr);
 107
 108   return player;
 109 }
 110
 111 char *getNetworkPlayerName(int player_nr)
 112 {
 113   struct NetworkClientPlayerInfo *player;
 114
 115   if (player_nr == 0)
 116     return("the network game server");
 117   else if (player_nr == first_player.nr)
 118     return("you");
 119   else
 120     for (player = &first_player; player; player = player->next)
 121       if (player->nr == player_nr && player->name && strlen(player->name))
 122         return(player->name);
 123
 124   return(EMPTY_PLAYER_NAME);
 125 }
 126
 127 static void StartNetworkServer(int port)
 128 {
 129 #if defined(TARGET_SDL)
 130   static int p;
 131
 132   p = port;
 133   server_thread = SDL_CreateThread(NetworkServerThread, &p);
 134   network_server = TRUE;
 135
 136 #else
 137
 138   switch (fork())
 139   {
 140     case 0:
 141       NetworkServer(port, options.serveronly);
 142
 143       /* never reached */
 144       exit(0);
 145
 146     case -1:
 147       Error(ERR_WARN,
 148             "cannot create network server process - no network playing");
 149       options.network = FALSE;
 150       return;
 151
 152     default:
 153       /* we are parent process -- resume normal operation */
 154       return;
 155   }
 156 #endif
 157 }
 158
 159 #if defined(TARGET_SDL)
 160 boolean ConnectToServer(char *hostname, int port)
 161 {
 162   IPaddress ip;
 163   int i;
 164
 165   if (port == 0)
 166     port = DEFAULT_SERVER_PORT;
 167
 168   rfds = SDLNet_AllocSocketSet(1);
 169
 170   if (hostname)
 171   {
 172     SDLNet_ResolveHost(&ip, hostname, port);
 173     if (ip.host == INADDR_NONE)
 174       Error(ERR_EXIT, "cannot locate host '%s'", hostname);
 175   }
 176   else
 177   {
 178     SDLNet_Write32(0x7f000001, &ip.host);       /* 127.0.0.1 */
 179     SDLNet_Write16(port, &ip.port);
 180   }
 181
 182   sfd = SDLNet_TCP_Open(&ip);
 183
 184   if (sfd)
 185   {
 186     SDLNet_TCP_AddSocket(rfds, sfd);
 187     return TRUE;
 188   }
 189   else
 190   {
 191     printf("SDLNet_TCP_Open(): %s\n", SDLNet_GetError());
 192   }
 193
 194   if (hostname)                 /* connect to specified server failed */
 195     return FALSE;
 196
 197   printf("No rocksndiamonds server on localhost -- starting up one ...\n");
 198   StartNetworkServer(port);
 199
 200   /* wait for server to start up and try connecting several times */
 201   for (i = 0; i < 6; i++)
 202   {
 203     Delay(500);                 /* wait 500 ms == 0.5 seconds */
 204
 205     if ((sfd = SDLNet_TCP_Open(&ip)))           /* connected */
 206     {
 207       SDLNet_TCP_AddSocket(rfds, sfd);
 208       return TRUE;
 209     }
 210   }
 211
 212   /* when reaching this point, connect to newly started server has failed */
 213   return FALSE;
 214 }
 215
 216 #else
 217
 218 boolean ConnectToServer(char *hostname, int port)
 219 {
 220   struct sockaddr_in s;
 221   struct protoent *tcpproto;
 222   int on = 1, i;
 223
 224   if (hostname)
 225   {
 226     if ((s.sin_addr.s_addr = inet_addr(hostname)) == -1)
 227     {
 228       struct hostent *host;
 229
 230       if ((host = gethostbyname(hostname)) == NULL)
 231         Error(ERR_EXIT, "cannot locate host '%s'", hostname);
 232
 233       s.sin_addr = *(struct in_addr *)(host->h_addr_list[0]);
 234     }
 235   }
 236   else
 237     s.sin_addr.s_addr = inet_addr("127.0.0.1");         /* localhost */
 238
 239   if (port == 0)
 240     port = DEFAULT_SERVER_PORT;
 241
 242   s.sin_port = htons(port);
 243   s.sin_family = AF_INET;
 244
 245   sfd = socket(PF_INET, SOCK_STREAM, 0);
 246   if (sfd < 0)
 247     Error(ERR_EXIT, "out of file descriptors");
 248
 249   if ((tcpproto = getprotobyname("tcp")) != NULL)
 250     setsockopt(sfd, tcpproto->p_proto, TCP_NODELAY, (char *)&on, sizeof(int));
 251
 252   if (connect(sfd, (struct sockaddr *)&s, sizeof(s)) == 0)      /* connected */
 253     return TRUE;
 254
 255   if (hostname) /* connect to specified server failed */
 256     return FALSE;
 257
 258   printf("No rocksndiamonds server on localhost -- starting up one ...\n");
 259   StartNetworkServer(port);
 260
 261   /* wait for server to start up and try connecting several times */
 262   for (i = 0; i < 6; i++)
 263   {
 264     Delay(500);         /* wait 500 ms == 0.5 seconds */
 265     close(sfd);
 266
 267     sfd = socket(PF_INET, SOCK_STREAM, 0);
 268     if (sfd < 0)
 269       Error(ERR_EXIT, "out of file descriptors");
 270
 271     setsockopt(sfd, tcpproto->p_proto, TCP_NODELAY, (char *)&on, sizeof(int));
 272
 273     if (connect(sfd, (struct sockaddr *)&s, sizeof(s)) >= 0)    /* connected */
 274       return TRUE;
 275   }
 276
 277   /* when reaching this point, connect to newly started server has failed */
 278   return FALSE;
 279 }
 280 #endif  /* defined(TARGET_SDL) */
 281
 282 void SendToServer_PlayerName(char *player_name)
 283 {
 284   int len_player_name = strlen(player_name);
 285
 286   buffer[1] = OP_PLAYER_NAME;
 287   memcpy(&buffer[2], player_name, len_player_name);
 288   SendBufferToServer(2 + len_player_name);
 289   Error(ERR_NETWORK_CLIENT, "you set your player name to \"%s\"", player_name);
 290 }
 291
 292 void SendToServer_ProtocolVersion()
 293 {
 294   buffer[1] = OP_PROTOCOL_VERSION;
 295   buffer[2] = PROTOCOL_VERSION_1;
 296   buffer[3] = PROTOCOL_VERSION_2;
 297   buffer[4] = PROTOCOL_VERSION_3;
 298
 299   SendBufferToServer(5);
 300 }
 301
 302 void SendToServer_NrWanted(int nr_wanted)
 303 {
 304   buffer[1] = OP_NUMBER_WANTED;
 305   buffer[2] = nr_wanted;
 306
 307   SendBufferToServer(3);
 308 }
 309
 310 void SendToServer_StartPlaying()
 311 {
 312   unsigned int new_random_seed = InitRND(level.random_seed);
 313
 314   int dummy = 0;                /* !!! HAS NO MEANING ANYMORE !!! */
 315                                 /* the name of the level must be enough */
 316
 317   buffer[1] = OP_START_PLAYING;
 318   buffer[2] = (byte)(level_nr >> 8);
 319   buffer[3] = (byte)(level_nr & 0xff);
 320   buffer[4] = (byte)(dummy >> 8);
 321   buffer[5] = (byte)(dummy & 0xff);
 322
 323   buffer[6] = (unsigned char)((new_random_seed >> 24) & 0xff);
 324   buffer[7] = (unsigned char)((new_random_seed >> 16) & 0xff);
 325   buffer[8] = (unsigned char)((new_random_seed >>  8) & 0xff);
 326   buffer[9] = (unsigned char)((new_random_seed >>  0) & 0xff);
 327
 328   strcpy((char *)&buffer[10], leveldir_current->identifier);
 329
 330   SendBufferToServer(10 + strlen(leveldir_current->identifier) + 1);
 331 }
 332
 333 void SendToServer_PausePlaying()
 334 {
 335   buffer[1] = OP_PAUSE_PLAYING;
 336
 337   SendBufferToServer(2);
 338 }
 339
 340 void SendToServer_ContinuePlaying()
 341 {
 342   buffer[1] = OP_CONTINUE_PLAYING;
 343
 344   SendBufferToServer(2);
 345 }
 346
 347 void SendToServer_StopPlaying(int cause_for_stopping)
 348 {
 349   buffer[1] = OP_STOP_PLAYING;
 350   buffer[2] = cause_for_stopping;
 351
 352   SendBufferToServer(3);
 353 }
 354
 355 void SendToServer_MovePlayer(byte player_action)
 356 {
 357   buffer[1] = OP_MOVE_PLAYER;
 358   buffer[2] = player_action;
 359
 360   SendBufferToServer(3);
 361 }
 362
 363 static void Handle_OP_BAD_PROTOCOL_VERSION()
 364 {
 365   Error(ERR_WARN, "protocol version mismatch");
 366   Error(ERR_EXIT, "server expects %d.%d.x instead of %d.%d.%d",
 367         buffer[2], buffer[3],
 368         PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 369 }
 370
 371 static void Handle_OP_YOUR_NUMBER()
 372 {
 373   int new_client_nr = buffer[2];
 374   int new_index_nr = new_client_nr - 1;
 375   struct PlayerInfo *old_local_player = local_player;
 376   struct PlayerInfo *new_local_player = &stored_player[new_index_nr];
 377
 378   printf("OP_YOUR_NUMBER: %d\n", buffer[0]);
 379   first_player.nr = new_client_nr;
 380
 381   if (old_local_player != new_local_player)
 382   {
 383     /* copy existing player settings and change to new player */
 384
 385     *new_local_player = *old_local_player;
 386     old_local_player->connected = FALSE;
 387     local_player = new_local_player;
 388   }
 389
 390   if (first_player.nr > MAX_PLAYERS)
 391     Error(ERR_EXIT, "sorry, more than %d players not allowed", MAX_PLAYERS);
 392
 393   Error(ERR_NETWORK_CLIENT, "you get client # %d", new_client_nr);
 394 }
 395
 396 static void Handle_OP_NUMBER_WANTED()
 397 {
 398   int client_nr_wanted = buffer[2];
 399   int old_client_nr = buffer[0];
 400   int new_client_nr = buffer[3];
 401   int old_index_nr = old_client_nr - 1;
 402   int new_index_nr = new_client_nr - 1;
 403   int index_nr_wanted = client_nr_wanted - 1;
 404   struct PlayerInfo *old_player = &stored_player[old_index_nr];
 405   struct PlayerInfo *new_player = &stored_player[new_index_nr];
 406
 407   printf("OP_NUMBER_WANTED: %d\n", buffer[0]);
 408
 409   if (new_client_nr == client_nr_wanted)        /* switching succeeded */
 410   {
 411     struct NetworkClientPlayerInfo *player;
 412
 413     if (old_client_nr != client_nr_wanted)      /* client's nr has changed */
 414       Error(ERR_NETWORK_CLIENT, "client %d switches to # %d",
 415             old_client_nr, new_client_nr);
 416     else if (old_client_nr == first_player.nr)  /* local player keeps his nr */
 417       Error(ERR_NETWORK_CLIENT, "keeping client # %d", new_client_nr);
 418
 419     if (old_client_nr != new_client_nr)
 420     {
 421       /* copy existing player settings and change to new player */
 422
 423       *new_player = *old_player;
 424       old_player->connected = FALSE;
 425     }
 426
 427     player = getNetworkPlayer(old_client_nr);
 428     player->nr = new_client_nr;
 429
 430     if (old_player == local_player)             /* local player switched */
 431       local_player = new_player;
 432   }
 433   else if (old_client_nr == first_player.nr)    /* failed -- local player? */
 434   {
 435     char request[100];
 436
 437     sprintf(request, "Sorry ! Player %d already exists ! You are player %d !",
 438             index_nr_wanted + 1, new_index_nr + 1);
 439
 440     Request(request, REQ_CONFIRM);
 441
 442     Error(ERR_NETWORK_CLIENT, "cannot switch -- you keep client # %d",
 443           new_client_nr);
 444   }
 445 }
 446
 447 static void Handle_OP_PLAYER_NAME(unsigned int len)
 448 {
 449   struct NetworkClientPlayerInfo *player;
 450   int player_nr = (int)buffer[0];
 451
 452   printf("OP_PLAYER_NAME: %d\n", player_nr);
 453   player = getNetworkPlayer(player_nr);
 454   buffer[len] = 0;
 455   Error(ERR_NETWORK_CLIENT, "client %d calls itself \"%s\"",
 456         buffer[0], &buffer[2]);
 457   strncpy(player->name, (char *)&buffer[2], MAX_PLAYER_NAME_LEN);
 458 }
 459
 460 static void Handle_OP_PLAYER_CONNECTED()
 461 {
 462   struct NetworkClientPlayerInfo *player, *last_player = NULL;
 463   int new_client_nr = (int)buffer[0];
 464   int new_index_nr = new_client_nr - 1;
 465
 466   printf("OP_PLAYER_CONNECTED: %d\n", new_client_nr);
 467   Error(ERR_NETWORK_CLIENT, "new client %d connected", new_client_nr);
 468
 469   for (player = &first_player; player; player = player->next)
 470   {
 471     if (player->nr == new_client_nr)
 472       Error(ERR_EXIT, "multiplayer server sent duplicate player id");
 473
 474     last_player = player;
 475   }
 476
 477   last_player->next = player =
 478     checked_malloc(sizeof(struct NetworkClientPlayerInfo));
 479   player->nr = new_client_nr;
 480   player->name[0] = '\0';
 481   player->next = NULL;
 482
 483   stored_player[new_index_nr].connected = TRUE;
 484 }
 485
 486 static void Handle_OP_PLAYER_DISCONNECTED()
 487 {
 488   struct NetworkClientPlayerInfo *player, *player_disconnected;
 489   int player_nr = (int)buffer[0];
 490
 491   printf("OP_PLAYER_DISCONNECTED: %d\n", player_nr);
 492   player_disconnected = getNetworkPlayer(player_nr);
 493   Error(ERR_NETWORK_CLIENT, "client %d (%s) disconnected",
 494         player_nr, getNetworkPlayerName(buffer[0]));
 495
 496   for (player = &first_player; player; player = player->next)
 497     if (player->next == player_disconnected)
 498       player->next = player_disconnected->next;
 499   free(player_disconnected);
 500 }
 501
 502 static void Handle_OP_START_PLAYING()
 503 {
 504   LevelDirTree *new_leveldir;
 505   int new_level_nr;
 506   unsigned int new_random_seed;
 507   char *new_leveldir_identifier;
 508
 509   new_level_nr = (buffer[2] << 8) + buffer[3];
 510   new_random_seed =
 511     (buffer[6] << 24) | (buffer[7] << 16) | (buffer[8] << 8) | (buffer[9]);
 512   new_leveldir_identifier = (char *)&buffer[10];
 513
 514   new_leveldir = getTreeInfoFromIdentifier(leveldir_first,
 515                                            new_leveldir_identifier);
 516   if (new_leveldir == NULL)
 517   {
 518     Error(ERR_WARN, "no such level identifier: '%s'", new_leveldir_identifier);
 519
 520     new_leveldir = leveldir_first;
 521     Error(ERR_WARN, "using default level set: '%s'", new_leveldir->identifier);
 522   }
 523
 524   printf("OP_START_PLAYING: %d\n", buffer[0]);
 525   Error(ERR_NETWORK_CLIENT,
 526         "client %d starts game [level %d from level identifier '%s']\n",
 527         buffer[0], new_level_nr, new_leveldir->identifier);
 528
 529   leveldir_current = new_leveldir;
 530   level_nr = new_level_nr;
 531
 532   TapeErase();
 533   LoadTape(level_nr);
 534   LoadLevel(level_nr);
 535
 536   StartGameActions(FALSE, setup.autorecord, new_random_seed);
 537 }
 538
 539 static void Handle_OP_PAUSE_PLAYING()
 540 {
 541   printf("OP_PAUSE_PLAYING: %d\n", buffer[0]);
 542   Error(ERR_NETWORK_CLIENT, "client %d pauses game", buffer[0]);
 543
 544   tape.pausing = TRUE;
 545   DrawVideoDisplay(VIDEO_STATE_PAUSE_ON,0);
 546 }
 547
 548 static void Handle_OP_CONTINUE_PLAYING()
 549 {
 550   printf("OP_CONTINUE_PLAYING: %d\n", buffer[0]);
 551   Error(ERR_NETWORK_CLIENT, "client %d continues game", buffer[0]);
 552
 553   tape.pausing = FALSE;
 554   DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF,0);
 555 }
 556
 557 static void Handle_OP_STOP_PLAYING()
 558 {
 559   printf("OP_STOP_PLAYING: %d [%d]\n", buffer[0], buffer[2]);
 560   Error(ERR_NETWORK_CLIENT, "client %d stops game [%d]", buffer[0], buffer[2]);
 561
 562   if (game_status == GAME_MODE_PLAYING)
 563   {
 564     if (buffer[2] == NETWORK_STOP_BY_PLAYER)
 565       Request("Network game stopped by player!", REQ_CONFIRM);
 566     else if (buffer[2] == NETWORK_STOP_BY_ERROR)
 567       Request("Network game stopped due to internal error!", REQ_CONFIRM);
 568     else
 569       Request("Network game stopped !", REQ_CONFIRM);
 570   }
 571
 572   game_status = GAME_MODE_MAIN;
 573   DrawMainMenu();
 574 }
 575
 576 static void Handle_OP_MOVE_PLAYER(unsigned int len)
 577 {
 578   int server_frame_counter;
 579   int i;
 580
 581   if (!network_playing)
 582     return;
 583
 584   server_frame_counter =
 585     (buffer[2] << 24) | (buffer[3] << 16) | (buffer[4] << 8) | (buffer[5]);
 586
 587 #if 0
 588   Error(ERR_NETWORK_CLIENT, "receiving server frame counter value %d [%d]",
 589         server_frame_counter, FrameCounter);
 590 #endif
 591
 592   if (server_frame_counter != FrameCounter)
 593   {
 594     Error(ERR_INFO, "client and servers frame counters out of sync");
 595     Error(ERR_INFO, "frame counter of client is %d", FrameCounter);
 596     Error(ERR_INFO, "frame counter of server is %d", server_frame_counter);
 597     Error(ERR_INFO, "this should not happen -- please debug");
 598
 599     stop_network_game = TRUE;
 600
 601     return;
 602   }
 603
 604   /* copy valid player actions */
 605   for (i = 0; i < MAX_PLAYERS; i++)
 606     stored_player[i].effective_action =
 607       (i < len - 6 && stored_player[i].active ? buffer[6 + i] : 0);
 608
 609   network_player_action_received = TRUE;
 610 }
 611
 612 static void HandleNetworkingMessages()
 613 {
 614   unsigned int message_length;
 615
 616   stop_network_game = FALSE;
 617
 618   while (nread >= 4 && nread >= 4 + readbuffer[3])
 619   {
 620     message_length = readbuffer[3];
 621     if (readbuffer[0] || readbuffer[1] || readbuffer[2])
 622       Error(ERR_EXIT, "wrong network server line length");
 623
 624     memcpy(buffer, &readbuffer[4], message_length);
 625     nread -= 4 + message_length;
 626     memmove(readbuffer, readbuffer + 4 + message_length, nread);
 627
 628     switch (buffer[1])
 629     {
 630       case OP_BAD_PROTOCOL_VERSION:
 631         Handle_OP_BAD_PROTOCOL_VERSION();
 632         break;
 633
 634       case OP_YOUR_NUMBER:
 635         Handle_OP_YOUR_NUMBER();
 636         break;
 637
 638       case OP_NUMBER_WANTED:
 639         Handle_OP_NUMBER_WANTED();
 640         break;
 641
 642       case OP_PLAYER_NAME:
 643         Handle_OP_PLAYER_NAME(message_length);
 644         break;
 645
 646       case OP_PLAYER_CONNECTED:
 647         Handle_OP_PLAYER_CONNECTED();
 648         break;
 649
 650       case OP_PLAYER_DISCONNECTED:
 651         Handle_OP_PLAYER_DISCONNECTED();
 652         break;
 653
 654       case OP_START_PLAYING:
 655         Handle_OP_START_PLAYING();
 656         break;
 657
 658       case OP_PAUSE_PLAYING:
 659         Handle_OP_PAUSE_PLAYING();
 660         break;
 661
 662       case OP_CONTINUE_PLAYING:
 663         Handle_OP_CONTINUE_PLAYING();
 664         break;
 665
 666       case OP_STOP_PLAYING:
 667         Handle_OP_STOP_PLAYING();
 668         break;
 669
 670       case OP_MOVE_PLAYER:
 671         Handle_OP_MOVE_PLAYER(message_length);
 672         break;
 673
 674       case OP_BROADCAST_MESSAGE:
 675         printf("OP_BROADCAST_MESSAGE: %d\n", buffer[0]);
 676         Error(ERR_NETWORK_CLIENT, "client %d sends message", buffer[0]);
 677         break;
 678     }
 679   }
 680
 681   fflush(stdout);
 682
 683   /* in case of internal error, stop network game */
 684   if (stop_network_game)
 685     SendToServer_StopPlaying(NETWORK_STOP_BY_ERROR);
 686 }
 687
 688 /* TODO */
 689
 690 void HandleNetworking()
 691 {
 692 #if !defined(TARGET_SDL)
 693   static struct timeval tv = { 0, 0 };
 694   fd_set rfds;
 695 #endif
 696   int r = 0;
 697
 698   do
 699   {
 700 #if defined(TARGET_SDL)
 701     if ((r = SDLNet_CheckSockets(rfds, 1)) < 0)
 702       Error(ERR_EXIT, "HandleNetworking(): SDLNet_CheckSockets() failed");
 703
 704 #else
 705
 706     FD_ZERO(&rfds);
 707     FD_SET(sfd, &rfds);
 708
 709     r = select(sfd + 1, &rfds, NULL, NULL, &tv);
 710
 711     if (r < 0 && errno != EINTR)
 712       Error(ERR_EXIT, "HandleNetworking(): select() failed");
 713
 714     if (r < 0)
 715       FD_ZERO(&rfds);
 716 #endif
 717
 718 #if defined(TARGET_SDL)
 719     if (r > 0)
 720 #else
 721     if (FD_ISSET(sfd, &rfds))
 722 #endif
 723     {
 724 #if defined(TARGET_SDL)
 725       r = SDLNet_TCP_Recv(sfd, readbuffer + nread, 1);
 726 #else
 727       r = read(sfd, readbuffer + nread, MAX_BUFFER_SIZE - nread);
 728 #endif
 729
 730       if (r < 0)
 731         Error(ERR_EXIT, "error reading from network server");
 732
 733       if (r == 0)
 734         Error(ERR_EXIT, "connection to network server lost");
 735
 736       nread += r;
 737
 738       HandleNetworkingMessages();
 739     }
 740   }
 741   while (r > 0);
 742 }
 743
 744 #endif /* PLATFORM_UNIX */