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 //                  https://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 #include "init.h"
  26
  27 struct NetworkClientPlayerInfo
  28 {
  29   byte nr;
  30   char name[MAX_PLAYER_NAME_LEN + 1];
  31   struct NetworkClientPlayerInfo *next;
  32 };
  33
  34 static struct NetworkClientPlayerInfo first_player =
  35 {
  36   0,
  37   EMPTY_PLAYER_NAME,
  38   NULL
  39 };
  40
  41 // server stuff
  42
  43 static TCPsocket sfd;           // TCP server socket
  44 static UDPsocket udp;           // UDP server socket
  45 static SDLNet_SocketSet rfds;   // socket set
  46
  47 static struct NetworkBuffer *read_buffer = NULL;
  48 static struct NetworkBuffer *write_buffer = NULL;
  49
  50 static boolean stop_network_game = FALSE;
  51 static boolean stop_network_client = FALSE;
  52 static char stop_network_client_message[MAX_OUTPUT_LINESIZE + 1];
  53
  54 static struct NetworkLevelInfo network_level;
  55
  56 static void DrawNetworkTextExt(char *message, int font_nr, boolean initialize)
  57 {
  58   static int xpos = 0, ypos = 0;
  59   static int max_line_width = 0;
  60   int font_width = getFontWidth(font_nr);
  61   int font_height = getFontHeight(font_nr);
  62   int ypos_1 = 120;
  63   int ypos_2 = 150;
  64
  65   if (initialize)
  66   {
  67     if (game_status == GAME_MODE_LOADING)
  68     {
  69       max_line_width = WIN_XSIZE;
  70
  71       xpos = (max_line_width - getTextWidth(message, font_nr)) / 2;
  72       ypos = ypos_1;
  73
  74       DrawText(xpos, ypos, message, font_nr);
  75
  76       xpos = 0;
  77       ypos = ypos_2;
  78     }
  79     else
  80     {
  81       max_line_width = SXSIZE;
  82
  83       DrawTextSCentered(ypos_1, font_nr, message);
  84
  85       // calculate offset to x position caused by rounding
  86       int max_chars_per_line = max_line_width / font_width;
  87       int xoffset = (max_line_width - max_chars_per_line * font_width) / 2;
  88
  89       xpos = SX + xoffset;
  90       ypos = SY + ypos_2;
  91     }
  92
  93     Debug("network:client", "========== %s ==========", message);
  94   }
  95   else
  96   {
  97     int max_chars_per_line = max_line_width / font_width;
  98     int max_lines_per_text = 10;
  99     int num_lines_spacing = (font_nr == FC_YELLOW ? 1 : 3);
 100     int num_lines_printed = DrawTextBuffer(xpos, ypos, message, font_nr,
 101                                            max_chars_per_line, -1,
 102                                            max_lines_per_text, 0, -1,
 103                                            TRUE, TRUE, FALSE);
 104
 105     ypos += (num_lines_printed + num_lines_spacing) * font_height;
 106
 107     Debug("network:client", "%s", message);
 108   }
 109
 110   BackToFront();
 111 }
 112
 113 static void DrawNetworkText(char *message)
 114 {
 115   DrawNetworkTextExt(message, FC_YELLOW, FALSE);
 116 }
 117
 118 static void DrawNetworkText_Success(char *message)
 119 {
 120   DrawNetworkTextExt(message, FC_GREEN, FALSE);
 121 }
 122
 123 static void DrawNetworkText_Failed(char *message)
 124 {
 125   DrawNetworkTextExt(message, FC_RED, FALSE);
 126 }
 127
 128 static void DrawNetworkText_Title(char *message)
 129 {
 130   DrawNetworkTextExt(message, FC_GREEN, TRUE);
 131 }
 132
 133 static void SendNetworkBufferToServer(struct NetworkBuffer *nb)
 134 {
 135   if (!network.enabled)
 136     return;
 137
 138   // set message length header
 139   putNetwork32BitInteger(nb->buffer, nb->size - 4);
 140
 141   // directly send the buffer to the network server
 142   SDLNet_TCP_Send(sfd, nb->buffer, nb->size);
 143 }
 144
 145 static struct NetworkClientPlayerInfo *getNetworkPlayer(int player_nr)
 146 {
 147   struct NetworkClientPlayerInfo *player = NULL;
 148
 149   for (player = &first_player; player; player = player->next)
 150     if (player->nr == player_nr)
 151       break;
 152
 153   if (player == NULL)   // should not happen
 154     Fail("protocol error: reference to non-existing player %d", player_nr);
 155
 156   return player;
 157 }
 158
 159 char *getNetworkPlayerName(int player_nr)
 160 {
 161   struct NetworkClientPlayerInfo *player;
 162
 163   if (player_nr == 0)
 164     return("the network game server");
 165   else if (player_nr == first_player.nr)
 166     return("you");
 167   else
 168     for (player = &first_player; player; player = player->next)
 169       if (player->nr == player_nr && strlen(player->name) > 0)
 170         return(player->name);
 171
 172   return(EMPTY_PLAYER_NAME);
 173 }
 174
 175 boolean hasStartedNetworkGame(void)
 176 {
 177   return !network_level.use_network_level_files;
 178 }
 179
 180 static boolean hasPathSeparator(char *s)
 181 {
 182   return (strchr(s, '/') != NULL);
 183 }
 184
 185 static void StartNetworkServer(int port)
 186 {
 187   static int p;
 188
 189   p = port;
 190
 191   network.server_thread = SDL_CreateThread(NetworkServerThread,
 192                                            "NetworkServerThread", &p);
 193 }
 194
 195 boolean ConnectToServer(char *hostname, int port)
 196 {
 197   IPaddress ip;
 198   int server_host = 0;
 199   int i;
 200
 201   if (read_buffer == NULL)
 202     read_buffer = newNetworkBuffer();
 203
 204   if (write_buffer == NULL)
 205     write_buffer = newNetworkBuffer();
 206
 207   DrawNetworkText_Title("Initializing Network");
 208
 209   if (port == 0)
 210     port = DEFAULT_SERVER_PORT;
 211
 212   if (hostname == NULL)
 213   {
 214     // if no hostname given, try to auto-detect network server in local network
 215     // by doing a UDP broadcast on the network server port and wait for answer
 216
 217     SDLNet_SocketSet udp_socket_set = SDLNet_AllocSocketSet(1);
 218     if (!udp_socket_set)
 219       Fail("SDLNet_AllocSocketSet() failed: %s"), SDLNet_GetError();
 220
 221     udp = SDLNet_UDP_Open(0);
 222     if (!udp)
 223       Fail("SDLNet_UDP_Open() failed: %s", SDLNet_GetError());
 224
 225     if (SDLNet_UDP_AddSocket(udp_socket_set, udp) == -1)
 226       Fail("SDLNet_TCP_AddSocket() failed: %s"), SDLNet_GetError();
 227
 228     char *data_ptr = "network server UDB broadcast";
 229     int data_len = strlen(data_ptr) + 1;
 230     IPaddress ip_address;
 231
 232     SDLNet_Write32(0xffffffff, &ip_address.host);       // 255.255.255.255
 233     SDLNet_Write16(port,       &ip_address.port);
 234
 235     UDPpacket packet =
 236     {
 237       -1,
 238       (Uint8 *)data_ptr,
 239       data_len,
 240       data_len,
 241       0,
 242       ip_address
 243     };
 244
 245     SDLNet_UDP_Send(udp, -1, &packet);
 246
 247     DrawNetworkText("Looking for nearby network server ...");
 248
 249     // wait for any nearby network server to answer UDP broadcast
 250     for (i = 0; i < 5; i++)
 251     {
 252       if (SDLNet_CheckSockets(udp_socket_set, 0) == 1)
 253       {
 254         int num_packets = SDLNet_UDP_Recv(udp, &packet);
 255
 256         if (num_packets == 1)
 257         {
 258           char message[100];
 259
 260           server_host = SDLNet_Read32(&packet.address.host);
 261
 262           sprintf(message, "Network server found at %d.%d.%d.%d!",
 263                   (server_host >> 24) & 0xff,
 264                   (server_host >> 16) & 0xff,
 265                   (server_host >>  8) & 0xff,
 266                   (server_host >>  0) & 0xff);
 267
 268           DrawNetworkText_Success(message);
 269         }
 270         else
 271         {
 272           DrawNetworkText_Failed("No answer from network server!");
 273         }
 274
 275         break;
 276       }
 277       else
 278       {
 279         Delay_WithScreenUpdates(100);
 280       }
 281     }
 282
 283     if (server_host == 0)
 284       DrawNetworkText_Failed("No nearby network server found!");
 285   }
 286
 287   rfds = SDLNet_AllocSocketSet(1);
 288
 289   if (hostname)
 290   {
 291     char message[100];
 292
 293     SDLNet_ResolveHost(&ip, hostname, port);
 294
 295     if (ip.host == INADDR_NONE)
 296     {
 297       sprintf(message, "Failed to resolve network server hostname '%s'!",
 298               hostname);
 299
 300       DrawNetworkText_Failed(message);
 301
 302       return FALSE;
 303     }
 304     else
 305     {
 306       server_host = SDLNet_Read32(&ip.host);
 307     }
 308
 309     sprintf(message, "Connecting to network server host %s ...", hostname);
 310
 311     DrawNetworkText(message);
 312   }
 313   else
 314   {
 315     // if no hostname was given and no network server was auto-detected in the
 316     // local network, try to connect to a network server at the local host
 317     if (server_host == 0)
 318     {
 319       server_host = 0x7f000001;                 // 127.0.0.1
 320
 321       DrawNetworkText("Looking for local network server ...");
 322     }
 323     else
 324     {
 325       DrawNetworkText("Connecting to network server ...");
 326     }
 327
 328     SDLNet_Write32(server_host, &ip.host);
 329     SDLNet_Write16(port,        &ip.port);
 330   }
 331
 332   Debug("network:client", "trying to connect to network server at %d.%d.%d.%d ...",
 333         (server_host >> 24) & 0xff,
 334         (server_host >> 16) & 0xff,
 335         (server_host >>  8) & 0xff,
 336         (server_host >>  0) & 0xff);
 337
 338   sfd = SDLNet_TCP_Open(&ip);
 339
 340   if (sfd)
 341   {
 342     SDLNet_TCP_AddSocket(rfds, sfd);
 343
 344     DrawNetworkText_Success("Successfully connected!");
 345
 346     return TRUE;
 347   }
 348   else
 349   {
 350     if (hostname)
 351       DrawNetworkText_Failed("Failed to connect to network server!");
 352     else
 353       DrawNetworkText_Failed("No local network server found!");
 354
 355     Debug("network:client", "SDLNet_TCP_Open(): %s", SDLNet_GetError());
 356   }
 357
 358   if (hostname)                 // connect to specified server failed
 359     return FALSE;
 360
 361   DrawNetworkText("Starting new local network server ...");
 362
 363   StartNetworkServer(port);
 364
 365   // wait for server to start up and try connecting several times
 366   for (i = 0; i < 30; i++)
 367   {
 368     if ((sfd = SDLNet_TCP_Open(&ip)))           // connected
 369     {
 370       DrawNetworkText_Success("Successfully connected to newly started network server!");
 371
 372       SDLNet_TCP_AddSocket(rfds, sfd);
 373
 374       return TRUE;
 375     }
 376
 377     Delay_WithScreenUpdates(100);
 378   }
 379
 380   DrawNetworkText_Failed("Failed to connect to newly started network server!");
 381
 382   // when reaching this point, connect to newly started server has failed
 383   return FALSE;
 384 }
 385
 386 void SendToServer_PlayerName(char *player_name)
 387 {
 388   initNetworkBufferForWriting(write_buffer, OP_PLAYER_NAME, 0);
 389
 390   putNetworkBufferString(write_buffer, player_name);
 391
 392   SendNetworkBufferToServer(write_buffer);
 393
 394   Debug("network:client", "you set your player name to \"%s\"", player_name);
 395 }
 396
 397 void SendToServer_ProtocolVersion(void)
 398 {
 399   initNetworkBufferForWriting(write_buffer, OP_PROTOCOL_VERSION, 0);
 400
 401   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MAJOR);
 402   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MINOR);
 403   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_PATCH);
 404
 405   SendNetworkBufferToServer(write_buffer);
 406 }
 407
 408 void SendToServer_NrWanted(int nr_wanted)
 409 {
 410   initNetworkBufferForWriting(write_buffer, OP_NUMBER_WANTED, 0);
 411
 412   putNetworkBuffer8BitInteger(write_buffer, nr_wanted);
 413
 414   SendNetworkBufferToServer(write_buffer);
 415 }
 416
 417 void SendToServer_LevelFile(void)
 418 {
 419   initNetworkBufferForWriting(write_buffer, OP_LEVEL_FILE, 0);
 420
 421   putNetworkBufferString(      write_buffer, leveldir_current->identifier);
 422   putNetworkBuffer16BitInteger(write_buffer, level.file_info.nr);
 423   putNetworkBuffer8BitInteger( write_buffer, level.file_info.type);
 424   putNetworkBuffer8BitInteger( write_buffer, level.file_info.packed);
 425   putNetworkBufferString(      write_buffer, level.file_info.basename);
 426   putNetworkBufferFile(        write_buffer, level.file_info.filename);
 427   putNetworkBuffer8BitInteger( write_buffer, level.use_custom_template);
 428
 429   if (level.use_custom_template)
 430   {
 431     putNetworkBufferString(write_buffer, level_template.file_info.basename);
 432     putNetworkBufferFile(  write_buffer, level_template.file_info.filename);
 433   }
 434
 435   SendNetworkBufferToServer(write_buffer);
 436
 437   setString(&network_level.leveldir_identifier, leveldir_current->identifier);
 438
 439   // the sending client does not use network level files (but the real ones)
 440   network_level.use_network_level_files = FALSE;
 441
 442 #if 0
 443   Debug("network:client", "'%s'", leveldir_current->identifier);
 444   Debug("network:client", "'%d'", level.file_info.nr);
 445   Debug("network:client", "'%d'", level.file_info.type);
 446   Debug("network:client", "'%d'", level.file_info.packed);
 447   Debug("network:client", "'%s'", level.file_info.basename);
 448   Debug("network:client", "'%s'", level.file_info.filename);
 449
 450   if (level.use_custom_template)
 451     Debug("network:client", "'%s'", level_template.file_info.filename);
 452 #endif
 453 }
 454
 455 void SendToServer_StartPlaying(void)
 456 {
 457   unsigned int new_random_seed = InitRND(level.random_seed);
 458
 459   initNetworkBufferForWriting(write_buffer, OP_START_PLAYING, 0);
 460
 461   putNetworkBufferString(      write_buffer, leveldir_current->identifier);
 462   putNetworkBuffer16BitInteger(write_buffer, level_nr);
 463   putNetworkBuffer32BitInteger(write_buffer, new_random_seed);
 464
 465   SendNetworkBufferToServer(write_buffer);
 466 }
 467
 468 void SendToServer_PausePlaying(void)
 469 {
 470   initNetworkBufferForWriting(write_buffer, OP_PAUSE_PLAYING, 0);
 471
 472   SendNetworkBufferToServer(write_buffer);
 473 }
 474
 475 void SendToServer_ContinuePlaying(void)
 476 {
 477   initNetworkBufferForWriting(write_buffer, OP_CONTINUE_PLAYING, 0);
 478
 479   SendNetworkBufferToServer(write_buffer);
 480 }
 481
 482 void SendToServer_StopPlaying(int cause_for_stopping)
 483 {
 484   initNetworkBufferForWriting(write_buffer, OP_STOP_PLAYING, 0);
 485
 486   putNetworkBuffer8BitInteger(write_buffer, cause_for_stopping);
 487
 488   SendNetworkBufferToServer(write_buffer);
 489 }
 490
 491 void SendToServer_MovePlayer(byte player_action)
 492 {
 493   initNetworkBufferForWriting(write_buffer, OP_MOVE_PLAYER, 0);
 494
 495   putNetworkBuffer8BitInteger(write_buffer, player_action);
 496
 497   SendNetworkBufferToServer(write_buffer);
 498 }
 499
 500 static void Handle_OP_BAD_PROTOCOL_VERSION(void)
 501 {
 502   int protocol_version_major = getNetworkBuffer8BitInteger(read_buffer);
 503   int protocol_version_minor = getNetworkBuffer8BitInteger(read_buffer);
 504
 505   Warn("protocol version mismatch");
 506   Warn("server expects %d.%d.x instead of %d.%d.%d",
 507         protocol_version_major,
 508         protocol_version_minor,
 509         PROTOCOL_VERSION_MAJOR,
 510         PROTOCOL_VERSION_MINOR,
 511         PROTOCOL_VERSION_PATCH);
 512
 513   sprintf(stop_network_client_message, "Network protocol version mismatch! Server expects version %d.%d.x instead of %d.%d.%d!",
 514           protocol_version_major,
 515           protocol_version_minor,
 516           PROTOCOL_VERSION_MAJOR,
 517           PROTOCOL_VERSION_MINOR,
 518           PROTOCOL_VERSION_PATCH);
 519
 520   stop_network_client = TRUE;
 521 }
 522
 523 static void Handle_OP_YOUR_NUMBER(void)
 524 {
 525   int old_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 526   int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 527   int new_index_nr = new_client_nr - 1;
 528   struct PlayerInfo *old_local_player = local_player;
 529   struct PlayerInfo *new_local_player = &stored_player[new_index_nr];
 530
 531   Debug("network:client", "OP_YOUR_NUMBER: %d", old_client_nr);
 532
 533   first_player.nr = new_client_nr;
 534
 535   if (old_local_player != new_local_player)
 536   {
 537     // set relevant player settings and change to new player
 538
 539     local_player = new_local_player;
 540
 541     old_local_player->connected_locally = FALSE;
 542     new_local_player->connected_locally = TRUE;
 543
 544     old_local_player->connected_network = FALSE;
 545     new_local_player->connected_network = TRUE;
 546   }
 547
 548   if (first_player.nr > MAX_PLAYERS)
 549     Fail("sorry, more than %d players not allowed", MAX_PLAYERS);
 550
 551   Debug("network:client", "you get client # %d", new_client_nr);
 552
 553   stored_player[new_index_nr].connected_network = TRUE;
 554 }
 555
 556 static void Handle_OP_NUMBER_WANTED(void)
 557 {
 558   int old_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
 559   int client_nr_wanted = getNetworkBuffer8BitInteger(read_buffer);
 560   int new_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
 561   int old_index_nr = old_client_nr - 1;
 562   int new_index_nr = new_client_nr - 1;
 563   int index_nr_wanted = client_nr_wanted - 1;
 564   struct PlayerInfo *old_player = &stored_player[old_index_nr];
 565   struct PlayerInfo *new_player = &stored_player[new_index_nr];
 566
 567   Debug("network:client", "OP_NUMBER_WANTED: %d", old_client_nr);
 568
 569   if (new_client_nr == client_nr_wanted)        // switching succeeded
 570   {
 571     struct NetworkClientPlayerInfo *player;
 572
 573     if (old_client_nr != client_nr_wanted)      // client's nr has changed
 574       Debug("network:client", "client %d switches to # %d",
 575             old_client_nr, new_client_nr);
 576     else if (old_client_nr == first_player.nr)  // local player keeps his nr
 577       Debug("network:client", "keeping client # %d", new_client_nr);
 578
 579     if (old_client_nr != new_client_nr)
 580     {
 581       // set relevant player settings and change to new player
 582
 583       old_player->connected_network = FALSE;
 584       new_player->connected_network = TRUE;
 585     }
 586
 587     player = getNetworkPlayer(old_client_nr);
 588     player->nr = new_client_nr;
 589
 590     if (old_player == local_player)             // local player switched
 591     {
 592       local_player = new_player;
 593
 594       old_player->connected_locally = FALSE;
 595       new_player->connected_locally = TRUE;
 596     }
 597   }
 598   else if (old_client_nr == first_player.nr)    // failed -- local player?
 599   {
 600     char request[100];
 601
 602     sprintf(request, "Sorry! Player %d already exists! You are player %d!",
 603             index_nr_wanted + 1, new_index_nr + 1);
 604
 605     Request(request, REQ_CONFIRM);
 606
 607     Debug("network:client", "cannot switch -- you keep client # %d",
 608           new_client_nr);
 609   }
 610
 611   if (game_status == GAME_MODE_MAIN)
 612     DrawNetworkPlayers();
 613 }
 614
 615 static void Handle_OP_PLAYER_NAME(void)
 616 {
 617   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 618   char *player_name = getNetworkBufferString(read_buffer);
 619   struct NetworkClientPlayerInfo *player = getNetworkPlayer(player_nr);
 620
 621   Debug("network:client", "OP_PLAYER_NAME: %d", player_nr);
 622
 623   strncpy(player->name, player_name, MAX_PLAYER_NAME_LEN);
 624   player->name[MAX_PLAYER_NAME_LEN] = '\0';
 625
 626   Debug("network:client", "client %d calls itself \"%s\"",
 627         player_nr, player->name);
 628 }
 629
 630 static void Handle_OP_PLAYER_CONNECTED(void)
 631 {
 632   struct NetworkClientPlayerInfo *player, *last_player = NULL;
 633   int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 634   int new_index_nr = new_client_nr - 1;
 635
 636   Debug("network:client", "OP_PLAYER_CONNECTED: %d", new_client_nr);
 637   Debug("network:client", "new client %d connected", new_client_nr);
 638
 639   for (player = &first_player; player; player = player->next)
 640   {
 641     if (player->nr == new_client_nr)
 642       Fail("multiplayer server sent duplicate player id");
 643
 644     last_player = player;
 645   }
 646
 647   last_player->next = player =
 648     checked_malloc(sizeof(struct NetworkClientPlayerInfo));
 649   player->nr = new_client_nr;
 650   player->name[0] = '\0';
 651   player->next = NULL;
 652
 653   stored_player[new_index_nr].connected_network = TRUE;
 654 }
 655
 656 static void Handle_OP_PLAYER_DISCONNECTED(void)
 657 {
 658   struct NetworkClientPlayerInfo *player, *player_disconnected;
 659   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 660   int index_nr = player_nr - 1;
 661
 662   Debug("network:client", "OP_PLAYER_DISCONNECTED: %d", player_nr);
 663   Debug("network:client", "client %d (%s) disconnected",
 664         player_nr, getNetworkPlayerName(player_nr));
 665
 666   player_disconnected = getNetworkPlayer(player_nr);
 667
 668   for (player = &first_player; player; player = player->next)
 669     if (player->next == player_disconnected)
 670       player->next = player_disconnected->next;
 671   free(player_disconnected);
 672
 673   stored_player[index_nr].connected_locally = FALSE;
 674   stored_player[index_nr].connected_network = FALSE;
 675
 676   if (game_status == GAME_MODE_PLAYING)
 677   {
 678     char message[100];
 679
 680     sprintf(message, "Player %d left network server! Network game stopped!",
 681             player_nr);
 682
 683     Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 684
 685     SetGameStatus(GAME_MODE_MAIN);
 686
 687     DrawMainMenu();
 688   }
 689   else if (game_status == GAME_MODE_MAIN)
 690   {
 691     DrawNetworkPlayers();
 692   }
 693 }
 694
 695 static void Handle_OP_START_PLAYING(void)
 696 {
 697   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 698   char *new_leveldir_identifier = getNetworkBufferString(read_buffer);
 699   int new_level_nr = getNetworkBuffer16BitInteger(read_buffer);
 700   unsigned int new_random_seed = getNetworkBuffer32BitInteger(read_buffer);
 701
 702   if (!strEqual(new_leveldir_identifier, network_level.leveldir_identifier))
 703   {
 704     Warn("no such level identifier: '%s'", new_leveldir_identifier);
 705
 706     stop_network_game = TRUE;
 707
 708     return;
 709   }
 710
 711   Debug("network:client", "OP_START_PLAYING: %d", player_nr);
 712   Debug("network:client",
 713         "client %d starts game [level %d from level identifier '%s']",
 714         player_nr, new_level_nr, new_leveldir_identifier);
 715
 716   LevelDirTree *new_leveldir =
 717     getTreeInfoFromIdentifier(leveldir_first, new_leveldir_identifier);
 718
 719   if (new_leveldir != NULL)
 720   {
 721     leveldir_current = new_leveldir;
 722     level_nr = new_level_nr;
 723   }
 724
 725   // needed if level set of network game changed graphics, sounds or music
 726   ReloadCustomArtwork(0);
 727
 728   TapeErase();
 729
 730   if (network_level.use_network_level_files)
 731     LoadNetworkLevel(&network_level);
 732   else
 733     LoadLevel(level_nr);
 734
 735   StartGameActions(FALSE, setup.autorecord, new_random_seed);
 736 }
 737
 738 static void Handle_OP_PAUSE_PLAYING(void)
 739 {
 740   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 741
 742   Debug("network:client", "OP_PAUSE_PLAYING: %d", player_nr);
 743   Debug("network:client", "client %d pauses game", player_nr);
 744
 745   if (game_status == GAME_MODE_PLAYING)
 746   {
 747     tape.pausing = TRUE;
 748     DrawVideoDisplay(VIDEO_STATE_PAUSE_ON, 0);
 749   }
 750 }
 751
 752 static void Handle_OP_CONTINUE_PLAYING(void)
 753 {
 754   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 755
 756   Debug("network:client", "OP_CONTINUE_PLAYING: %d", player_nr);
 757   Debug("network:client", "client %d continues game", player_nr);
 758
 759   if (game_status == GAME_MODE_PLAYING)
 760   {
 761     tape.pausing = FALSE;
 762     DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF, 0);
 763   }
 764 }
 765
 766 static void Handle_OP_STOP_PLAYING(void)
 767 {
 768   int client_nr = getNetworkBuffer8BitInteger(read_buffer);
 769   int cause_for_stopping = getNetworkBuffer8BitInteger(read_buffer);
 770
 771   Debug("network:client", "OP_STOP_PLAYING: %d [%d]",
 772         client_nr, cause_for_stopping);
 773   Debug("network:client", "client %d stops game [%d]",
 774         client_nr, cause_for_stopping);
 775
 776   if (game_status == GAME_MODE_PLAYING)
 777   {
 778     int index_nr = client_nr - 1;
 779     struct PlayerInfo *client_player = &stored_player[index_nr];
 780     boolean stopped_by_remote_player = (!client_player->connected_locally);
 781     char message[100];
 782
 783     if (cause_for_stopping == NETWORK_STOP_BY_PLAYER)
 784       sprintf(message, "Network game stopped by player %d!", client_nr);
 785     else
 786       sprintf(message, (cause_for_stopping == NETWORK_STOP_BY_ERROR ?
 787                         "Network game stopped due to internal error!" :
 788                         "Network game stopped!"));
 789
 790     if (cause_for_stopping != NETWORK_STOP_BY_PLAYER ||
 791         stopped_by_remote_player)
 792       Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 793
 794     SetGameStatus(GAME_MODE_MAIN);
 795
 796     DrawMainMenu();
 797   }
 798 }
 799
 800 static void Handle_OP_MOVE_PLAYER(void)
 801 {
 802   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 803   int server_frame_counter = getNetworkBuffer32BitInteger(read_buffer);
 804   int i;
 805
 806   if (!network_playing)
 807     return;
 808
 809   if (server_frame_counter != FrameCounter)
 810   {
 811     Warn("frame counters of client %d and server out of sync", player_nr);
 812     Warn("frame counter of client is %d", FrameCounter);
 813     Warn("frame counter of server is %d", server_frame_counter);
 814     Warn("this should not happen -- please debug");
 815
 816     stop_network_game = TRUE;
 817
 818     return;
 819   }
 820
 821   // copy valid player actions (will be set to 0 for not connected players)
 822   for (i = 0; i < MAX_PLAYERS; i++)
 823     stored_player[i].effective_action =
 824       getNetworkBuffer8BitInteger(read_buffer);
 825
 826   network_player_action_received = TRUE;
 827 }
 828
 829 static void Handle_OP_BROADCAST_MESSAGE(void)
 830 {
 831   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 832
 833   Debug("network:client", "OP_BROADCAST_MESSAGE: %d", player_nr);
 834   Debug("network:client", "client %d sends message", player_nr);
 835 }
 836
 837 static void Handle_OP_LEVEL_FILE(void)
 838 {
 839   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 840   char *leveldir_identifier;
 841   char *network_level_dir;
 842   struct LevelFileInfo *file_info = &network_level.file_info;
 843   struct LevelFileInfo *tmpl_info = &network_level.tmpl_info;
 844   boolean use_custom_template;
 845
 846   setString(&network_level.leveldir_identifier, NULL);
 847   setString(&network_level.file_info.basename,  NULL);
 848   setString(&network_level.file_info.filename,  NULL);
 849   setString(&network_level.tmpl_info.basename,  NULL);
 850   setString(&network_level.tmpl_info.filename,  NULL);
 851
 852   Debug("network:client", "OP_LEVEL_FILE: %d", player_nr);
 853
 854   leveldir_identifier = getStringCopy(getNetworkBufferString(read_buffer));
 855
 856   if (hasPathSeparator(leveldir_identifier))
 857     Fail("protocol error: invalid filename from network client");
 858
 859   InitNetworkLevelDirectory(leveldir_identifier);
 860
 861   network_level_dir   = getNetworkLevelDir(leveldir_identifier);
 862
 863   file_info->nr       = getNetworkBuffer16BitInteger(read_buffer);
 864   file_info->type     = getNetworkBuffer8BitInteger(read_buffer);
 865   file_info->packed   = getNetworkBuffer8BitInteger(read_buffer);
 866   file_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
 867   file_info->filename = getPath2(network_level_dir, file_info->basename);
 868
 869   if (hasPathSeparator(file_info->basename))
 870     Fail("protocol error: invalid filename from network client");
 871
 872   int num_bytes = getNetworkBufferFile(read_buffer, file_info->filename);
 873
 874   // if received level file is empty, remove it (as being non-existent)
 875   if (num_bytes == 0)
 876     remove(file_info->filename);
 877
 878   use_custom_template = getNetworkBuffer8BitInteger(read_buffer);
 879   if (use_custom_template)
 880   {
 881     *tmpl_info = *file_info;
 882
 883     tmpl_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
 884     tmpl_info->filename = getPath2(network_level_dir, tmpl_info->basename);
 885
 886     if (hasPathSeparator(tmpl_info->basename))
 887       Fail("protocol error: invalid filename from network client");
 888
 889     getNetworkBufferFile(read_buffer, tmpl_info->filename);
 890
 891     // if received level file is empty, use level template file instead
 892     if (num_bytes == 0)
 893       setString(&file_info->filename,  tmpl_info->filename);
 894   }
 895
 896   network_level.leveldir_identifier = leveldir_identifier;
 897   network_level.use_custom_template = use_custom_template;
 898
 899   // the receiving client(s) use(s) the transferred network level files
 900   network_level.use_network_level_files = TRUE;
 901
 902 #if 0
 903   Debug("network:client", "'%s'", leveldir_identifier);
 904   Debug("network:client", "'%d'", file_info->nr);
 905   Debug("network:client", "'%d'", file_info->type);
 906   Debug("network:client", "'%d'", file_info->packed);
 907   Debug("network:client", "'%s'", file_info->basename);
 908   Debug("network:client", "'%s'", file_info->filename);
 909
 910   if (use_custom_template)
 911     Debug("network:client", "'%s'", tmpl_info->filename);
 912 #endif
 913 }
 914
 915 static void HandleNetworkingMessage(void)
 916 {
 917   stop_network_game = FALSE;
 918
 919   initNetworkBufferForReading(read_buffer);
 920
 921   int message_type = getNetworkBuffer8BitInteger(read_buffer);
 922
 923   switch (message_type)
 924   {
 925     case OP_BAD_PROTOCOL_VERSION:
 926       Handle_OP_BAD_PROTOCOL_VERSION();
 927       break;
 928
 929     case OP_YOUR_NUMBER:
 930       Handle_OP_YOUR_NUMBER();
 931       break;
 932
 933     case OP_NUMBER_WANTED:
 934       Handle_OP_NUMBER_WANTED();
 935       break;
 936
 937     case OP_PLAYER_NAME:
 938       Handle_OP_PLAYER_NAME();
 939       break;
 940
 941     case OP_PLAYER_CONNECTED:
 942       Handle_OP_PLAYER_CONNECTED();
 943       break;
 944
 945     case OP_PLAYER_DISCONNECTED:
 946       Handle_OP_PLAYER_DISCONNECTED();
 947       break;
 948
 949     case OP_START_PLAYING:
 950       Handle_OP_START_PLAYING();
 951       break;
 952
 953     case OP_PAUSE_PLAYING:
 954       Handle_OP_PAUSE_PLAYING();
 955       break;
 956
 957     case OP_CONTINUE_PLAYING:
 958       Handle_OP_CONTINUE_PLAYING();
 959       break;
 960
 961     case OP_STOP_PLAYING:
 962       Handle_OP_STOP_PLAYING();
 963       break;
 964
 965     case OP_MOVE_PLAYER:
 966       Handle_OP_MOVE_PLAYER();
 967       break;
 968
 969     case OP_BROADCAST_MESSAGE:
 970       Handle_OP_BROADCAST_MESSAGE();
 971       break;
 972
 973     case OP_LEVEL_FILE:
 974       Handle_OP_LEVEL_FILE();
 975       break;
 976
 977     default:
 978       Debug("network:client", "unknown opcode %d from server", message_type);
 979   }
 980
 981   fflush(stdout);
 982
 983   // in case of internal error, stop network game
 984   if (stop_network_game)
 985     SendToServer_StopPlaying(NETWORK_STOP_BY_ERROR);
 986 }
 987
 988 static char *HandleNetworkingPackets(void)
 989 {
 990   while (1)
 991   {
 992     // ---------- check network server for activity ----------
 993
 994     int num_active_sockets = SDLNet_CheckSockets(rfds, 0);
 995
 996     if (num_active_sockets < 0)
 997       return "Error checking network sockets!";
 998
 999     if (num_active_sockets == 0)
1000       break;    // no active sockets, stop here
1001
1002     // ---------- read packets from network server ----------
1003
1004     initNetworkBufferForReceiving(read_buffer);
1005
1006     int num_bytes = receiveNetworkBufferPacket(read_buffer, sfd);
1007
1008     if (num_bytes < 0)
1009       return "Error reading from network server!";
1010
1011     if (num_bytes == 0)
1012       return "Connection to network server lost!";
1013
1014     HandleNetworkingMessage();
1015
1016     if (stop_network_client)
1017       return stop_network_client_message;
1018   }
1019
1020   return NULL;
1021 }
1022
1023 static void FreeNetworkClientPlayerInfo(struct NetworkClientPlayerInfo *player)
1024 {
1025   if (player == NULL)
1026     return;
1027
1028   if (player->next)
1029     FreeNetworkClientPlayerInfo(player->next);
1030
1031   checked_free(player);
1032 }
1033
1034 static void HandleNetworkingDisconnect(void)
1035 {
1036   int i;
1037
1038   SDLNet_TCP_DelSocket(rfds, sfd);
1039   SDLNet_TCP_Close(sfd);
1040
1041   network_playing = FALSE;
1042
1043   network.enabled = FALSE;
1044   network.connected = FALSE;
1045
1046   setup.network_mode = FALSE;
1047
1048   for (i = 0; i < MAX_PLAYERS; i++)
1049     stored_player[i].connected_network = FALSE;
1050
1051   FreeNetworkClientPlayerInfo(first_player.next);
1052
1053   first_player.nr = 0;
1054   first_player.next = NULL;
1055 }
1056
1057 void HandleNetworking(void)
1058 {
1059   // do not handle any networking packets if request dialog is active
1060   if (game.request_active)
1061     return;
1062
1063   char *error_message = HandleNetworkingPackets();
1064
1065   if (error_message != NULL)
1066   {
1067     HandleNetworkingDisconnect();
1068
1069     if (game_status == GAME_MODE_PLAYING)
1070     {
1071       Request(error_message, REQ_CONFIRM | REQ_STAY_CLOSED);
1072
1073       SetGameStatus(GAME_MODE_MAIN);
1074
1075       DrawMainMenu();
1076     }
1077     else
1078     {
1079       Request(error_message, REQ_CONFIRM);
1080
1081       if (game_status == GAME_MODE_MAIN)
1082         ClearNetworkPlayers();
1083     }
1084   }
1085 }
1086
1087 void DisconnectFromNetworkServer(void)
1088 {
1089   DrawNetworkText_Title("Terminating Network");
1090   DrawNetworkText("Disconnecting from network server ...");
1091
1092   HandleNetworkingDisconnect();
1093
1094   DrawNetworkText_Success("Successfully disconnected!");
1095 }