src/network.c

   1 // ============================================================================
   2 // Rocks'n'Diamonds - McDuffin Strikes Back!
   3 // ----------------------------------------------------------------------------
   4 // (c) 1995-2014 by Artsoft Entertainment
   5 //                  Holger Schemel
   6 //                  info@artsoft.org
   7 //                  http://www.artsoft.org/
   8 // ----------------------------------------------------------------------------
   9 // network.c
  10 // ============================================================================
  11
  12 #include <signal.h>
  13 #include <sys/time.h>
  14
  15 #include "libgame/libgame.h"
  16
  17 #include "network.h"
  18 #include "netserv.h"
  19 #include "main.h"
  20 #include "game.h"
  21 #include "tape.h"
  22 #include "files.h"
  23 #include "tools.h"
  24 #include "screens.h"
  25
  26 struct NetworkClientPlayerInfo
  27 {
  28   byte nr;
  29   char name[MAX_PLAYER_NAME_LEN + 1];
  30   struct NetworkClientPlayerInfo *next;
  31 };
  32
  33 static struct NetworkClientPlayerInfo first_player =
  34 {
  35   0,
  36   EMPTY_PLAYER_NAME,
  37   NULL
  38 };
  39
  40 /* server stuff */
  41
  42 static TCPsocket sfd;           /* TCP server socket */
  43 static UDPsocket udp;           /* UDP server socket */
  44 static SDLNet_SocketSet rfds;   /* socket set */
  45
  46 static byte realbuffer[512];
  47 static byte readbuffer[MAX_BUFFER_SIZE], writbuffer[MAX_BUFFER_SIZE];
  48 static byte *buffer = realbuffer + 4;
  49 static int nread = 0, nwrite = 0;
  50 static boolean stop_network_game = FALSE;
  51
  52 static void DrawNetworkTextExt(char *message, int font_nr, boolean initialize)
  53 {
  54   static int xpos = 0, ypos = 0;
  55   int font_width = getFontWidth(font_nr);
  56   int font_height = getFontHeight(font_nr);
  57
  58   if (initialize)
  59   {
  60     xpos = (WIN_XSIZE - getTextWidth(message, font_nr)) / 2;
  61     ypos = 120;
  62
  63     DrawText(xpos, ypos, message, font_nr);
  64
  65     xpos = 0;
  66     ypos = 150;
  67
  68     Error(ERR_DEBUG, "========== %s ==========", message);
  69   }
  70   else
  71   {
  72     int max_chars_per_line = WIN_XSIZE / font_width;
  73     int max_lines_per_text = 10;
  74     int num_lines_spacing = (font_nr == FC_YELLOW ? 1 : 3);
  75     int num_lines_printed = DrawTextBuffer(xpos, ypos, message, font_nr,
  76                                            max_chars_per_line, -1,
  77                                            max_lines_per_text, 0, -1,
  78                                            TRUE, TRUE, FALSE);
  79
  80     ypos += (num_lines_printed + num_lines_spacing) * font_height;
  81
  82     Error(ERR_DEBUG, "%s", message);
  83   }
  84
  85   BackToFront();
  86 }
  87
  88 static void DrawNetworkText(char *message)
  89 {
  90   DrawNetworkTextExt(message, FC_YELLOW, FALSE);
  91 }
  92
  93 static void DrawNetworkText_Success(char *message)
  94 {
  95   DrawNetworkTextExt(message, FC_GREEN, FALSE);
  96 }
  97
  98 static void DrawNetworkText_Failed(char *message)
  99 {
 100   DrawNetworkTextExt(message, FC_RED, FALSE);
 101 }
 102
 103 static void DrawNetworkText_Title(char *message)
 104 {
 105   DrawNetworkTextExt(message, FC_GREEN, TRUE);
 106 }
 107
 108 static void SendBufferToServer(int size)
 109 {
 110   if (!network.enabled)
 111     return;
 112
 113   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
 114   realbuffer[3] = (byte)size;
 115   buffer[0] = 0;
 116
 117   if (nwrite + 4 + size >= MAX_BUFFER_SIZE)
 118     Error(ERR_EXIT, "internal error: network send buffer overflow");
 119
 120   memcpy(writbuffer + nwrite, realbuffer, 4 + size);
 121   nwrite += 4 + size;
 122
 123   /* directly send the buffer to the network server */
 124   SDLNet_TCP_Send(sfd, writbuffer, nwrite);
 125   nwrite = 0;
 126 }
 127
 128 struct NetworkClientPlayerInfo *getNetworkPlayer(int player_nr)
 129 {
 130   struct NetworkClientPlayerInfo *player = NULL;
 131
 132   for (player = &first_player; player; player = player->next)
 133     if (player->nr == player_nr)
 134       break;
 135
 136   if (player == NULL)   /* should not happen */
 137     Error(ERR_EXIT, "protocol error: reference to non-existing player %d",
 138           player_nr);
 139
 140   return player;
 141 }
 142
 143 char *getNetworkPlayerName(int player_nr)
 144 {
 145   struct NetworkClientPlayerInfo *player;
 146
 147   if (player_nr == 0)
 148     return("the network game server");
 149   else if (player_nr == first_player.nr)
 150     return("you");
 151   else
 152     for (player = &first_player; player; player = player->next)
 153       if (player->nr == player_nr && strlen(player->name) > 0)
 154         return(player->name);
 155
 156   return(EMPTY_PLAYER_NAME);
 157 }
 158
 159 static void StartNetworkServer(int port)
 160 {
 161   static int p;
 162
 163   p = port;
 164 #if defined(TARGET_SDL2)
 165   server_thread = SDL_CreateThread(NetworkServerThread,
 166                                    "NetworkServerThread", &p);
 167 #else
 168   server_thread = SDL_CreateThread(NetworkServerThread, &p);
 169 #endif
 170   network_server = TRUE;
 171 }
 172
 173 boolean ConnectToServer(char *hostname, int port)
 174 {
 175   IPaddress ip;
 176   int server_host = 0;
 177   int i;
 178
 179   DrawNetworkText_Title("Initializing Network");
 180
 181   if (port == 0)
 182     port = DEFAULT_SERVER_PORT;
 183
 184   if (hostname == NULL)
 185   {
 186     // if no hostname given, try to auto-detect network server in local network
 187     // by doing a UDP broadcast on the network server port and wait for answer
 188
 189     SDLNet_SocketSet udp_socket_set = SDLNet_AllocSocketSet(1);
 190     if (!udp_socket_set)
 191       Error(ERR_EXIT, "SDLNet_AllocSocketSet() failed: %s"), SDLNet_GetError();
 192
 193     udp = SDLNet_UDP_Open(0);
 194     if(!udp)
 195       Error(ERR_EXIT, "SDLNet_UDP_Open() failed: %s", SDLNet_GetError());
 196
 197     if (SDLNet_UDP_AddSocket(udp_socket_set, udp) == -1)
 198       Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 199         SDLNet_GetError();
 200
 201     char *data_ptr = "network server UDB broadcast";
 202     int data_len = strlen(data_ptr) + 1;
 203     IPaddress ip_address;
 204
 205     SDLNet_Write32(0xffffffff, &ip_address.host);       /* 255.255.255.255 */
 206     SDLNet_Write16(port,       &ip_address.port);
 207
 208     UDPpacket packet =
 209     {
 210       -1,
 211       (Uint8 *)data_ptr,
 212       data_len,
 213       data_len,
 214       0,
 215       ip_address
 216     };
 217
 218     SDLNet_UDP_Send(udp, -1, &packet);
 219
 220     DrawNetworkText("Looking for local network server ...");
 221
 222     if (SDLNet_CheckSockets(udp_socket_set, 1000) == 1)
 223     {
 224       int num_packets = SDLNet_UDP_Recv(udp, &packet);
 225
 226       if (num_packets == 1)
 227       {
 228         DrawNetworkText_Success("Network server found!");
 229
 230         server_host = SDLNet_Read32(&packet.address.host);
 231       }
 232       else
 233       {
 234         DrawNetworkText_Failed("No answer from network server!");
 235       }
 236     }
 237     else
 238     {
 239       DrawNetworkText_Failed("No network server found!");
 240     }
 241   }
 242
 243   rfds = SDLNet_AllocSocketSet(1);
 244
 245   if (hostname)
 246   {
 247     SDLNet_ResolveHost(&ip, hostname, port);
 248
 249     if (ip.host == INADDR_NONE)
 250       Error(ERR_EXIT, "cannot locate host '%s'", hostname);
 251     else
 252       server_host = SDLNet_Read32(&ip.host);
 253
 254     DrawNetworkText("Connecting to remote host ...");
 255   }
 256   else
 257   {
 258     // if no hostname was given and no network server was auto-detected in the
 259     // local network, try to connect to a network server at the local host
 260     if (server_host == 0)
 261       server_host = 0x7f000001;                 /* 127.0.0.1 */
 262
 263     SDLNet_Write32(server_host, &ip.host);
 264     SDLNet_Write16(port,        &ip.port);
 265
 266     DrawNetworkText("Connecting to local host ...");
 267   }
 268
 269   Error(ERR_DEBUG, "trying to connect to network server at %d.%d.%d.%d ...",
 270         (server_host >> 24) & 0xff,
 271         (server_host >> 16) & 0xff,
 272         (server_host >>  8) & 0xff,
 273         (server_host >>  0) & 0xff);
 274
 275   sfd = SDLNet_TCP_Open(&ip);
 276
 277   if (sfd)
 278   {
 279     SDLNet_TCP_AddSocket(rfds, sfd);
 280
 281     DrawNetworkText_Success("Successfully connected!");
 282
 283     return TRUE;
 284   }
 285   else
 286   {
 287     DrawNetworkText_Failed("Failed to connect to network server!");
 288
 289     printf("SDLNet_TCP_Open(): %s\n", SDLNet_GetError());
 290   }
 291
 292   if (hostname)                 /* connect to specified server failed */
 293     return FALSE;
 294
 295   DrawNetworkText("Starting new local network server ...");
 296
 297   StartNetworkServer(port);
 298
 299   /* wait for server to start up and try connecting several times */
 300   for (i = 0; i < 6; i++)
 301   {
 302     Delay(500);                 /* wait 500 ms == 0.5 seconds */
 303
 304     if ((sfd = SDLNet_TCP_Open(&ip)))           /* connected */
 305     {
 306       DrawNetworkText_Success("Successfully connected!");
 307
 308       SDLNet_TCP_AddSocket(rfds, sfd);
 309       return TRUE;
 310     }
 311   }
 312
 313   DrawNetworkText_Failed("Failed to connect to network server!");
 314
 315   /* when reaching this point, connect to newly started server has failed */
 316   return FALSE;
 317 }
 318
 319 void SendToServer_PlayerName(char *player_name)
 320 {
 321   int len_player_name = strlen(player_name);
 322
 323   buffer[1] = OP_PLAYER_NAME;
 324   memcpy(&buffer[2], player_name, len_player_name);
 325   SendBufferToServer(2 + len_player_name);
 326   Error(ERR_NETWORK_CLIENT, "you set your player name to \"%s\"", player_name);
 327 }
 328
 329 void SendToServer_ProtocolVersion()
 330 {
 331   buffer[1] = OP_PROTOCOL_VERSION;
 332   buffer[2] = PROTOCOL_VERSION_1;
 333   buffer[3] = PROTOCOL_VERSION_2;
 334   buffer[4] = PROTOCOL_VERSION_3;
 335
 336   SendBufferToServer(5);
 337 }
 338
 339 void SendToServer_NrWanted(int nr_wanted)
 340 {
 341   buffer[1] = OP_NUMBER_WANTED;
 342   buffer[2] = nr_wanted;
 343
 344   SendBufferToServer(3);
 345 }
 346
 347 void SendToServer_StartPlaying()
 348 {
 349   unsigned int new_random_seed = InitRND(level.random_seed);
 350
 351   int dummy = 0;                /* !!! HAS NO MEANING ANYMORE !!! */
 352                                 /* the name of the level must be enough */
 353
 354   buffer[1] = OP_START_PLAYING;
 355   buffer[2] = (byte)(level_nr >> 8);
 356   buffer[3] = (byte)(level_nr & 0xff);
 357   buffer[4] = (byte)(dummy >> 8);
 358   buffer[5] = (byte)(dummy & 0xff);
 359
 360   buffer[6] = (unsigned char)((new_random_seed >> 24) & 0xff);
 361   buffer[7] = (unsigned char)((new_random_seed >> 16) & 0xff);
 362   buffer[8] = (unsigned char)((new_random_seed >>  8) & 0xff);
 363   buffer[9] = (unsigned char)((new_random_seed >>  0) & 0xff);
 364
 365   strcpy((char *)&buffer[10], leveldir_current->identifier);
 366
 367   SendBufferToServer(10 + strlen(leveldir_current->identifier) + 1);
 368 }
 369
 370 void SendToServer_PausePlaying()
 371 {
 372   buffer[1] = OP_PAUSE_PLAYING;
 373
 374   SendBufferToServer(2);
 375 }
 376
 377 void SendToServer_ContinuePlaying()
 378 {
 379   buffer[1] = OP_CONTINUE_PLAYING;
 380
 381   SendBufferToServer(2);
 382 }
 383
 384 void SendToServer_StopPlaying(int cause_for_stopping)
 385 {
 386   buffer[1] = OP_STOP_PLAYING;
 387   buffer[2] = cause_for_stopping;
 388
 389   SendBufferToServer(3);
 390 }
 391
 392 void SendToServer_MovePlayer(byte player_action)
 393 {
 394   buffer[1] = OP_MOVE_PLAYER;
 395   buffer[2] = player_action;
 396
 397   SendBufferToServer(3);
 398 }
 399
 400 static void Handle_OP_BAD_PROTOCOL_VERSION()
 401 {
 402   Error(ERR_WARN, "protocol version mismatch");
 403   Error(ERR_EXIT, "server expects %d.%d.x instead of %d.%d.%d",
 404         buffer[2], buffer[3],
 405         PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 406 }
 407
 408 static void Handle_OP_YOUR_NUMBER()
 409 {
 410   int new_client_nr = buffer[2];
 411   int new_index_nr = new_client_nr - 1;
 412   struct PlayerInfo *old_local_player = local_player;
 413   struct PlayerInfo *new_local_player = &stored_player[new_index_nr];
 414
 415   printf("OP_YOUR_NUMBER: %d\n", buffer[0]);
 416   first_player.nr = new_client_nr;
 417
 418   if (old_local_player != new_local_player)
 419   {
 420     /* set relevant player settings and change to new player */
 421
 422     local_player = new_local_player;
 423
 424     old_local_player->connected_locally = FALSE;
 425     new_local_player->connected_locally = TRUE;
 426
 427     old_local_player->connected_network = FALSE;
 428     new_local_player->connected_network = TRUE;
 429   }
 430
 431   if (first_player.nr > MAX_PLAYERS)
 432     Error(ERR_EXIT, "sorry, more than %d players not allowed", MAX_PLAYERS);
 433
 434   Error(ERR_NETWORK_CLIENT, "you get client # %d", new_client_nr);
 435 }
 436
 437 static void Handle_OP_NUMBER_WANTED()
 438 {
 439   int client_nr_wanted = buffer[2];
 440   int old_client_nr = buffer[0];
 441   int new_client_nr = buffer[3];
 442   int old_index_nr = old_client_nr - 1;
 443   int new_index_nr = new_client_nr - 1;
 444   int index_nr_wanted = client_nr_wanted - 1;
 445   struct PlayerInfo *old_player = &stored_player[old_index_nr];
 446   struct PlayerInfo *new_player = &stored_player[new_index_nr];
 447
 448   printf("OP_NUMBER_WANTED: %d\n", buffer[0]);
 449
 450   if (new_client_nr == client_nr_wanted)        /* switching succeeded */
 451   {
 452     struct NetworkClientPlayerInfo *player;
 453
 454     if (old_client_nr != client_nr_wanted)      /* client's nr has changed */
 455       Error(ERR_NETWORK_CLIENT, "client %d switches to # %d",
 456             old_client_nr, new_client_nr);
 457     else if (old_client_nr == first_player.nr)  /* local player keeps his nr */
 458       Error(ERR_NETWORK_CLIENT, "keeping client # %d", new_client_nr);
 459
 460     if (old_client_nr != new_client_nr)
 461     {
 462       /* set relevant player settings and change to new player */
 463
 464       old_player->connected_network = FALSE;
 465       new_player->connected_network = TRUE;
 466     }
 467
 468     player = getNetworkPlayer(old_client_nr);
 469     player->nr = new_client_nr;
 470
 471     if (old_player == local_player)             /* local player switched */
 472     {
 473       local_player = new_player;
 474
 475       old_player->connected_locally = FALSE;
 476       new_player->connected_locally = TRUE;
 477     }
 478   }
 479   else if (old_client_nr == first_player.nr)    /* failed -- local player? */
 480   {
 481     char request[100];
 482
 483     sprintf(request, "Sorry! Player %d already exists! You are player %d!",
 484             index_nr_wanted + 1, new_index_nr + 1);
 485
 486     Request(request, REQ_CONFIRM);
 487
 488     Error(ERR_NETWORK_CLIENT, "cannot switch -- you keep client # %d",
 489           new_client_nr);
 490   }
 491 }
 492
 493 static void Handle_OP_PLAYER_NAME(unsigned int len)
 494 {
 495   struct NetworkClientPlayerInfo *player;
 496   int player_nr = (int)buffer[0];
 497
 498   printf("OP_PLAYER_NAME: %d\n", player_nr);
 499   player = getNetworkPlayer(player_nr);
 500   buffer[len] = 0;
 501   Error(ERR_NETWORK_CLIENT, "client %d calls itself \"%s\"",
 502         buffer[0], &buffer[2]);
 503   strncpy(player->name, (char *)&buffer[2], MAX_PLAYER_NAME_LEN);
 504 }
 505
 506 static void Handle_OP_PLAYER_CONNECTED()
 507 {
 508   struct NetworkClientPlayerInfo *player, *last_player = NULL;
 509   int new_client_nr = (int)buffer[0];
 510   int new_index_nr = new_client_nr - 1;
 511
 512   printf("OP_PLAYER_CONNECTED: %d\n", new_client_nr);
 513   Error(ERR_NETWORK_CLIENT, "new client %d connected", new_client_nr);
 514
 515   for (player = &first_player; player; player = player->next)
 516   {
 517     if (player->nr == new_client_nr)
 518       Error(ERR_EXIT, "multiplayer server sent duplicate player id");
 519
 520     last_player = player;
 521   }
 522
 523   last_player->next = player =
 524     checked_malloc(sizeof(struct NetworkClientPlayerInfo));
 525   player->nr = new_client_nr;
 526   player->name[0] = '\0';
 527   player->next = NULL;
 528
 529   stored_player[new_index_nr].connected_network = TRUE;
 530 }
 531
 532 static void Handle_OP_PLAYER_DISCONNECTED()
 533 {
 534   struct NetworkClientPlayerInfo *player, *player_disconnected;
 535   int player_nr = (int)buffer[0];
 536   int index_nr = player_nr - 1;
 537
 538   printf("OP_PLAYER_DISCONNECTED: %d\n", player_nr);
 539   player_disconnected = getNetworkPlayer(player_nr);
 540   Error(ERR_NETWORK_CLIENT, "client %d (%s) disconnected",
 541         player_nr, getNetworkPlayerName(buffer[0]));
 542
 543   for (player = &first_player; player; player = player->next)
 544     if (player->next == player_disconnected)
 545       player->next = player_disconnected->next;
 546   free(player_disconnected);
 547
 548   stored_player[index_nr].connected_locally = FALSE;
 549   stored_player[index_nr].connected_network = FALSE;
 550 }
 551
 552 static void Handle_OP_START_PLAYING()
 553 {
 554   LevelDirTree *new_leveldir;
 555   int new_level_nr;
 556   unsigned int new_random_seed;
 557   char *new_leveldir_identifier;
 558
 559   new_level_nr = (buffer[2] << 8) + buffer[3];
 560   new_random_seed =
 561     (buffer[6] << 24) | (buffer[7] << 16) | (buffer[8] << 8) | (buffer[9]);
 562   new_leveldir_identifier = (char *)&buffer[10];
 563
 564   new_leveldir = getTreeInfoFromIdentifier(leveldir_first,
 565                                            new_leveldir_identifier);
 566   if (new_leveldir == NULL)
 567   {
 568     Error(ERR_WARN, "no such level identifier: '%s'", new_leveldir_identifier);
 569
 570     new_leveldir = leveldir_first;
 571     Error(ERR_WARN, "using default level set: '%s'", new_leveldir->identifier);
 572   }
 573
 574   printf("OP_START_PLAYING: %d\n", buffer[0]);
 575   Error(ERR_NETWORK_CLIENT,
 576         "client %d starts game [level %d from level identifier '%s']\n",
 577         buffer[0], new_level_nr, new_leveldir->identifier);
 578
 579   leveldir_current = new_leveldir;
 580   level_nr = new_level_nr;
 581
 582   TapeErase();
 583   LoadTape(level_nr);
 584   LoadLevel(level_nr);
 585
 586   StartGameActions(FALSE, setup.autorecord, new_random_seed);
 587 }
 588
 589 static void Handle_OP_PAUSE_PLAYING()
 590 {
 591   printf("OP_PAUSE_PLAYING: %d\n", buffer[0]);
 592   Error(ERR_NETWORK_CLIENT, "client %d pauses game", buffer[0]);
 593
 594   tape.pausing = TRUE;
 595   DrawVideoDisplay(VIDEO_STATE_PAUSE_ON,0);
 596 }
 597
 598 static void Handle_OP_CONTINUE_PLAYING()
 599 {
 600   printf("OP_CONTINUE_PLAYING: %d\n", buffer[0]);
 601   Error(ERR_NETWORK_CLIENT, "client %d continues game", buffer[0]);
 602
 603   tape.pausing = FALSE;
 604   DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF,0);
 605 }
 606
 607 static void Handle_OP_STOP_PLAYING()
 608 {
 609   printf("OP_STOP_PLAYING: %d [%d]\n", buffer[0], buffer[2]);
 610   Error(ERR_NETWORK_CLIENT, "client %d stops game [%d]", buffer[0], buffer[2]);
 611
 612   if (game_status == GAME_MODE_PLAYING)
 613   {
 614     int client_nr = buffer[0];
 615     int index_nr = client_nr - 1;
 616     struct PlayerInfo *client_player = &stored_player[index_nr];
 617     boolean stopped_by_remote_player = (!client_player->connected_locally);
 618     char *message = (buffer[2] == NETWORK_STOP_BY_PLAYER ?
 619                      "Network game stopped by player!" :
 620                      buffer[2] == NETWORK_STOP_BY_ERROR ?
 621                      "Network game stopped due to internal error!" :
 622                      "Network game stopped!");
 623
 624     if (buffer[2] != NETWORK_STOP_BY_PLAYER || stopped_by_remote_player)
 625       Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 626   }
 627
 628   SetGameStatus(GAME_MODE_MAIN);
 629
 630   DrawMainMenu();
 631 }
 632
 633 static void Handle_OP_MOVE_PLAYER(unsigned int len)
 634 {
 635   int server_frame_counter;
 636   int i;
 637
 638   if (!network_playing)
 639     return;
 640
 641   server_frame_counter =
 642     (buffer[2] << 24) | (buffer[3] << 16) | (buffer[4] << 8) | (buffer[5]);
 643
 644   if (server_frame_counter != FrameCounter)
 645   {
 646     Error(ERR_INFO, "client and servers frame counters out of sync");
 647     Error(ERR_INFO, "frame counter of client is %d", FrameCounter);
 648     Error(ERR_INFO, "frame counter of server is %d", server_frame_counter);
 649     Error(ERR_INFO, "this should not happen -- please debug");
 650
 651     stop_network_game = TRUE;
 652
 653     return;
 654   }
 655
 656   /* copy valid player actions */
 657   for (i = 0; i < MAX_PLAYERS; i++)
 658     stored_player[i].effective_action =
 659       (i < len - 6 ? buffer[6 + i] : 0);
 660
 661   network_player_action_received = TRUE;
 662 }
 663
 664 static void HandleNetworkingMessages()
 665 {
 666   unsigned int message_length;
 667
 668   stop_network_game = FALSE;
 669
 670   while (nread >= 4 && nread >= 4 + readbuffer[3])
 671   {
 672     message_length = readbuffer[3];
 673     if (readbuffer[0] || readbuffer[1] || readbuffer[2])
 674       Error(ERR_EXIT, "wrong network server line length");
 675
 676     memcpy(buffer, &readbuffer[4], message_length);
 677     nread -= 4 + message_length;
 678     memmove(readbuffer, readbuffer + 4 + message_length, nread);
 679
 680     switch (buffer[1])
 681     {
 682       case OP_BAD_PROTOCOL_VERSION:
 683         Handle_OP_BAD_PROTOCOL_VERSION();
 684         break;
 685
 686       case OP_YOUR_NUMBER:
 687         Handle_OP_YOUR_NUMBER();
 688         break;
 689
 690       case OP_NUMBER_WANTED:
 691         Handle_OP_NUMBER_WANTED();
 692         break;
 693
 694       case OP_PLAYER_NAME:
 695         Handle_OP_PLAYER_NAME(message_length);
 696         break;
 697
 698       case OP_PLAYER_CONNECTED:
 699         Handle_OP_PLAYER_CONNECTED();
 700         break;
 701
 702       case OP_PLAYER_DISCONNECTED:
 703         Handle_OP_PLAYER_DISCONNECTED();
 704         break;
 705
 706       case OP_START_PLAYING:
 707         Handle_OP_START_PLAYING();
 708         break;
 709
 710       case OP_PAUSE_PLAYING:
 711         Handle_OP_PAUSE_PLAYING();
 712         break;
 713
 714       case OP_CONTINUE_PLAYING:
 715         Handle_OP_CONTINUE_PLAYING();
 716         break;
 717
 718       case OP_STOP_PLAYING:
 719         Handle_OP_STOP_PLAYING();
 720         break;
 721
 722       case OP_MOVE_PLAYER:
 723         Handle_OP_MOVE_PLAYER(message_length);
 724         break;
 725
 726       case OP_BROADCAST_MESSAGE:
 727         printf("OP_BROADCAST_MESSAGE: %d\n", buffer[0]);
 728         Error(ERR_NETWORK_CLIENT, "client %d sends message", buffer[0]);
 729         break;
 730     }
 731   }
 732
 733   fflush(stdout);
 734
 735   /* in case of internal error, stop network game */
 736   if (stop_network_game)
 737     SendToServer_StopPlaying(NETWORK_STOP_BY_ERROR);
 738 }
 739
 740 static char *HandleNetworkingPackets()
 741 {
 742   while (1)
 743   {
 744     /* ---------- check network server for activity ---------- */
 745
 746     int num_active_sockets = SDLNet_CheckSockets(rfds, 1);
 747
 748     if (num_active_sockets < 0)
 749       return "Error checking network sockets!";
 750
 751     if (num_active_sockets == 0)
 752       break;    // no active sockets, stop here
 753
 754     /* ---------- read packets from network server ---------- */
 755
 756     int num_bytes = SDLNet_TCP_Recv(sfd, readbuffer + nread, 1);
 757
 758     if (num_bytes < 0)
 759       return "Error reading from network server!";
 760
 761     if (num_bytes == 0)
 762       return "Connection to network server lost!";
 763
 764     nread += num_bytes;
 765
 766     HandleNetworkingMessages();
 767   }
 768
 769   return NULL;
 770 }
 771
 772 static void HandleNetworkingDisconnect()
 773 {
 774   int i;
 775
 776   SDLNet_TCP_DelSocket(rfds, sfd);
 777   SDLNet_TCP_Close(sfd);
 778
 779   network_playing = FALSE;
 780
 781   network.enabled = FALSE;
 782   network.connected = FALSE;
 783
 784   setup.network_mode = FALSE;
 785
 786   for (i = 0; i < MAX_PLAYERS; i++)
 787     stored_player[i].connected_network = FALSE;
 788 }
 789
 790 void HandleNetworking()
 791 {
 792   char *error_message = HandleNetworkingPackets();
 793
 794   if (error_message != NULL)
 795   {
 796     HandleNetworkingDisconnect();
 797
 798     if (game_status == GAME_MODE_PLAYING)
 799     {
 800       Request(error_message, REQ_CONFIRM | REQ_STAY_CLOSED);
 801
 802       SetGameStatus(GAME_MODE_MAIN);
 803
 804       DrawMainMenu();
 805     }
 806     else
 807     {
 808       Request(error_message, REQ_CONFIRM);
 809     }
 810   }
 811 }
 812
 813 void DisconnectFromNetworkServer()
 814 {
 815   DrawNetworkText_Title("Terminating Network");
 816   DrawNetworkText("Disconnecting from network server ...");
 817
 818   HandleNetworkingDisconnect();
 819
 820   DrawNetworkText_Success("Successfully disconnected!");
 821
 822   /* short time to recognize result of network initialization */
 823   Delay(1000);
 824 }