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