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 #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     Error(ERR_DEBUG, "========== %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     Error(ERR_DEBUG, "%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     Error(ERR_EXIT, "protocol error: reference to non-existing player %d",
 155           player_nr);
 156
 157   return player;
 158 }
 159
 160 char *getNetworkPlayerName(int player_nr)
 161 {
 162   struct NetworkClientPlayerInfo *player;
 163
 164   if (player_nr == 0)
 165     return("the network game server");
 166   else if (player_nr == first_player.nr)
 167     return("you");
 168   else
 169     for (player = &first_player; player; player = player->next)
 170       if (player->nr == player_nr && strlen(player->name) > 0)
 171         return(player->name);
 172
 173   return(EMPTY_PLAYER_NAME);
 174 }
 175
 176 boolean hasStartedNetworkGame(void)
 177 {
 178   return !network_level.use_network_level_files;
 179 }
 180
 181 static boolean hasPathSeparator(char *s)
 182 {
 183   return (strchr(s, '/') != NULL);
 184 }
 185
 186 static void StartNetworkServer(int port)
 187 {
 188   static int p;
 189
 190   p = port;
 191
 192   server_thread = SDL_CreateThread(NetworkServerThread,
 193                                    "NetworkServerThread", &p);
 194   network_server = TRUE;
 195 }
 196
 197 boolean ConnectToServer(char *hostname, int port)
 198 {
 199   IPaddress ip;
 200   int server_host = 0;
 201   int i;
 202
 203   if (read_buffer == NULL)
 204     read_buffer = newNetworkBuffer();
 205
 206   if (write_buffer == NULL)
 207     write_buffer = newNetworkBuffer();
 208
 209   DrawNetworkText_Title("Initializing Network");
 210
 211   if (port == 0)
 212     port = DEFAULT_SERVER_PORT;
 213
 214   if (hostname == NULL)
 215   {
 216     // if no hostname given, try to auto-detect network server in local network
 217     // by doing a UDP broadcast on the network server port and wait for answer
 218
 219     SDLNet_SocketSet udp_socket_set = SDLNet_AllocSocketSet(1);
 220     if (!udp_socket_set)
 221       Error(ERR_EXIT, "SDLNet_AllocSocketSet() failed: %s"), SDLNet_GetError();
 222
 223     udp = SDLNet_UDP_Open(0);
 224     if (!udp)
 225       Error(ERR_EXIT, "SDLNet_UDP_Open() failed: %s", SDLNet_GetError());
 226
 227     if (SDLNet_UDP_AddSocket(udp_socket_set, udp) == -1)
 228       Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 229         SDLNet_GetError();
 230
 231     char *data_ptr = "network server UDB broadcast";
 232     int data_len = strlen(data_ptr) + 1;
 233     IPaddress ip_address;
 234
 235     SDLNet_Write32(0xffffffff, &ip_address.host);       // 255.255.255.255
 236     SDLNet_Write16(port,       &ip_address.port);
 237
 238     UDPpacket packet =
 239     {
 240       -1,
 241       (Uint8 *)data_ptr,
 242       data_len,
 243       data_len,
 244       0,
 245       ip_address
 246     };
 247
 248     SDLNet_UDP_Send(udp, -1, &packet);
 249
 250     DrawNetworkText("Looking for nearby network server ...");
 251
 252     // wait for any nearby network server to answer UDP broadcast
 253     for (i = 0; i < 5; i++)
 254     {
 255       if (SDLNet_CheckSockets(udp_socket_set, 0) == 1)
 256       {
 257         int num_packets = SDLNet_UDP_Recv(udp, &packet);
 258
 259         if (num_packets == 1)
 260         {
 261           char message[100];
 262
 263           server_host = SDLNet_Read32(&packet.address.host);
 264
 265           sprintf(message, "Network server found at %d.%d.%d.%d!",
 266                   (server_host >> 24) & 0xff,
 267                   (server_host >> 16) & 0xff,
 268                   (server_host >>  8) & 0xff,
 269                   (server_host >>  0) & 0xff);
 270
 271           DrawNetworkText_Success(message);
 272         }
 273         else
 274         {
 275           DrawNetworkText_Failed("No answer from network server!");
 276         }
 277
 278         break;
 279       }
 280       else
 281       {
 282         Delay_WithScreenUpdates(100);
 283       }
 284     }
 285
 286     if (server_host == 0)
 287       DrawNetworkText_Failed("No nearby network server found!");
 288   }
 289
 290   rfds = SDLNet_AllocSocketSet(1);
 291
 292   if (hostname)
 293   {
 294     char message[100];
 295
 296     SDLNet_ResolveHost(&ip, hostname, port);
 297
 298     if (ip.host == INADDR_NONE)
 299     {
 300       sprintf(message, "Failed to resolve network server hostname '%s'!",
 301               hostname);
 302
 303       DrawNetworkText_Failed(message);
 304
 305       return FALSE;
 306     }
 307     else
 308     {
 309       server_host = SDLNet_Read32(&ip.host);
 310     }
 311
 312     sprintf(message, "Connecting to network server host %s ...", hostname);
 313
 314     DrawNetworkText(message);
 315   }
 316   else
 317   {
 318     // if no hostname was given and no network server was auto-detected in the
 319     // local network, try to connect to a network server at the local host
 320     if (server_host == 0)
 321     {
 322       server_host = 0x7f000001;                 // 127.0.0.1
 323
 324       DrawNetworkText("Looking for local network server ...");
 325     }
 326     else
 327     {
 328       DrawNetworkText("Connecting to network server ...");
 329     }
 330
 331     SDLNet_Write32(server_host, &ip.host);
 332     SDLNet_Write16(port,        &ip.port);
 333   }
 334
 335   Error(ERR_DEBUG, "trying to connect to network server at %d.%d.%d.%d ...",
 336         (server_host >> 24) & 0xff,
 337         (server_host >> 16) & 0xff,
 338         (server_host >>  8) & 0xff,
 339         (server_host >>  0) & 0xff);
 340
 341   sfd = SDLNet_TCP_Open(&ip);
 342
 343   if (sfd)
 344   {
 345     SDLNet_TCP_AddSocket(rfds, sfd);
 346
 347     DrawNetworkText_Success("Successfully connected!");
 348
 349     return TRUE;
 350   }
 351   else
 352   {
 353     if (hostname)
 354       DrawNetworkText_Failed("Failed to connect to network server!");
 355     else
 356       DrawNetworkText_Failed("No local network server found!");
 357
 358     printf("SDLNet_TCP_Open(): %s\n", SDLNet_GetError());
 359   }
 360
 361   if (hostname)                 // connect to specified server failed
 362     return FALSE;
 363
 364   DrawNetworkText("Starting new local network server ...");
 365
 366   StartNetworkServer(port);
 367
 368   // wait for server to start up and try connecting several times
 369   for (i = 0; i < 30; i++)
 370   {
 371     if ((sfd = SDLNet_TCP_Open(&ip)))           // connected
 372     {
 373       DrawNetworkText_Success("Successfully connected to newly started network server!");
 374
 375       SDLNet_TCP_AddSocket(rfds, sfd);
 376
 377       return TRUE;
 378     }
 379
 380     Delay_WithScreenUpdates(100);
 381   }
 382
 383   DrawNetworkText_Failed("Failed to connect to newly started network server!");
 384
 385   // when reaching this point, connect to newly started server has failed
 386   return FALSE;
 387 }
 388
 389 void SendToServer_PlayerName(char *player_name)
 390 {
 391   initNetworkBufferForWriting(write_buffer, OP_PLAYER_NAME, 0);
 392
 393   putNetworkBufferString(write_buffer, player_name);
 394
 395   SendNetworkBufferToServer(write_buffer);
 396
 397   Error(ERR_NETWORK_CLIENT, "you set your player name to \"%s\"", player_name);
 398 }
 399
 400 void SendToServer_ProtocolVersion(void)
 401 {
 402   initNetworkBufferForWriting(write_buffer, OP_PROTOCOL_VERSION, 0);
 403
 404   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MAJOR);
 405   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MINOR);
 406   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_PATCH);
 407
 408   SendNetworkBufferToServer(write_buffer);
 409 }
 410
 411 void SendToServer_NrWanted(int nr_wanted)
 412 {
 413   initNetworkBufferForWriting(write_buffer, OP_NUMBER_WANTED, 0);
 414
 415   putNetworkBuffer8BitInteger(write_buffer, nr_wanted);
 416
 417   SendNetworkBufferToServer(write_buffer);
 418 }
 419
 420 void SendToServer_LevelFile(void)
 421 {
 422   initNetworkBufferForWriting(write_buffer, OP_LEVEL_FILE, 0);
 423
 424   putNetworkBufferString(      write_buffer, leveldir_current->identifier);
 425   putNetworkBuffer16BitInteger(write_buffer, level.file_info.nr);
 426   putNetworkBuffer8BitInteger( write_buffer, level.file_info.type);
 427   putNetworkBuffer8BitInteger( write_buffer, level.file_info.packed);
 428   putNetworkBufferString(      write_buffer, level.file_info.basename);
 429   putNetworkBufferFile(        write_buffer, level.file_info.filename);
 430   putNetworkBuffer8BitInteger( write_buffer, level.use_custom_template);
 431
 432   if (level.use_custom_template)
 433   {
 434     putNetworkBufferString(write_buffer, level_template.file_info.basename);
 435     putNetworkBufferFile(  write_buffer, level_template.file_info.filename);
 436   }
 437
 438   SendNetworkBufferToServer(write_buffer);
 439
 440   setString(&network_level.leveldir_identifier, leveldir_current->identifier);
 441
 442   // the sending client does not use network level files (but the real ones)
 443   network_level.use_network_level_files = FALSE;
 444
 445 #if 0
 446   printf("::: '%s'\n", leveldir_current->identifier);
 447   printf("::: '%d'\n", level.file_info.nr);
 448   printf("::: '%d'\n", level.file_info.type);
 449   printf("::: '%d'\n", level.file_info.packed);
 450   printf("::: '%s'\n", level.file_info.basename);
 451   printf("::: '%s'\n", level.file_info.filename);
 452
 453   if (level.use_custom_template)
 454     printf("::: '%s'\n", level_template.file_info.filename);
 455 #endif
 456 }
 457
 458 void SendToServer_StartPlaying(void)
 459 {
 460   unsigned int new_random_seed = InitRND(level.random_seed);
 461
 462   initNetworkBufferForWriting(write_buffer, OP_START_PLAYING, 0);
 463
 464   putNetworkBufferString(      write_buffer, leveldir_current->identifier);
 465   putNetworkBuffer16BitInteger(write_buffer, level_nr);
 466   putNetworkBuffer32BitInteger(write_buffer, new_random_seed);
 467
 468   SendNetworkBufferToServer(write_buffer);
 469 }
 470
 471 void SendToServer_PausePlaying(void)
 472 {
 473   initNetworkBufferForWriting(write_buffer, OP_PAUSE_PLAYING, 0);
 474
 475   SendNetworkBufferToServer(write_buffer);
 476 }
 477
 478 void SendToServer_ContinuePlaying(void)
 479 {
 480   initNetworkBufferForWriting(write_buffer, OP_CONTINUE_PLAYING, 0);
 481
 482   SendNetworkBufferToServer(write_buffer);
 483 }
 484
 485 void SendToServer_StopPlaying(int cause_for_stopping)
 486 {
 487   initNetworkBufferForWriting(write_buffer, OP_STOP_PLAYING, 0);
 488
 489   putNetworkBuffer8BitInteger(write_buffer, cause_for_stopping);
 490
 491   SendNetworkBufferToServer(write_buffer);
 492 }
 493
 494 void SendToServer_MovePlayer(byte player_action)
 495 {
 496   initNetworkBufferForWriting(write_buffer, OP_MOVE_PLAYER, 0);
 497
 498   putNetworkBuffer8BitInteger(write_buffer, player_action);
 499
 500   SendNetworkBufferToServer(write_buffer);
 501 }
 502
 503 static void Handle_OP_BAD_PROTOCOL_VERSION(void)
 504 {
 505   int protocol_version_major = getNetworkBuffer8BitInteger(read_buffer);
 506   int protocol_version_minor = getNetworkBuffer8BitInteger(read_buffer);
 507
 508   Error(ERR_WARN, "protocol version mismatch");
 509   Error(ERR_WARN, "server expects %d.%d.x instead of %d.%d.%d",
 510         protocol_version_major,
 511         protocol_version_minor,
 512         PROTOCOL_VERSION_MAJOR,
 513         PROTOCOL_VERSION_MINOR,
 514         PROTOCOL_VERSION_PATCH);
 515
 516   sprintf(stop_network_client_message, "Network protocol version mismatch! Server expects version %d.%d.x instead of %d.%d.%d!",
 517           protocol_version_major,
 518           protocol_version_minor,
 519           PROTOCOL_VERSION_MAJOR,
 520           PROTOCOL_VERSION_MINOR,
 521           PROTOCOL_VERSION_PATCH);
 522
 523   stop_network_client = TRUE;
 524 }
 525
 526 static void Handle_OP_YOUR_NUMBER(void)
 527 {
 528   int old_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 529   int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 530   int new_index_nr = new_client_nr - 1;
 531   struct PlayerInfo *old_local_player = local_player;
 532   struct PlayerInfo *new_local_player = &stored_player[new_index_nr];
 533
 534   printf("OP_YOUR_NUMBER: %d\n", old_client_nr);
 535   first_player.nr = new_client_nr;
 536
 537   if (old_local_player != new_local_player)
 538   {
 539     // set relevant player settings and change to new player
 540
 541     local_player = new_local_player;
 542
 543     old_local_player->connected_locally = FALSE;
 544     new_local_player->connected_locally = TRUE;
 545
 546     old_local_player->connected_network = FALSE;
 547     new_local_player->connected_network = TRUE;
 548   }
 549
 550   if (first_player.nr > MAX_PLAYERS)
 551     Error(ERR_EXIT, "sorry, more than %d players not allowed", MAX_PLAYERS);
 552
 553   Error(ERR_NETWORK_CLIENT, "you get client # %d", new_client_nr);
 554
 555   stored_player[new_index_nr].connected_network = TRUE;
 556 }
 557
 558 static void Handle_OP_NUMBER_WANTED(void)
 559 {
 560   int old_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
 561   int client_nr_wanted = getNetworkBuffer8BitInteger(read_buffer);
 562   int new_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
 563   int old_index_nr = old_client_nr - 1;
 564   int new_index_nr = new_client_nr - 1;
 565   int index_nr_wanted = client_nr_wanted - 1;
 566   struct PlayerInfo *old_player = &stored_player[old_index_nr];
 567   struct PlayerInfo *new_player = &stored_player[new_index_nr];
 568
 569   printf("OP_NUMBER_WANTED: %d\n", old_client_nr);
 570
 571   if (new_client_nr == client_nr_wanted)        // switching succeeded
 572   {
 573     struct NetworkClientPlayerInfo *player;
 574
 575     if (old_client_nr != client_nr_wanted)      // client's nr has changed
 576       Error(ERR_NETWORK_CLIENT, "client %d switches to # %d",
 577             old_client_nr, new_client_nr);
 578     else if (old_client_nr == first_player.nr)  // local player keeps his nr
 579       Error(ERR_NETWORK_CLIENT, "keeping client # %d", new_client_nr);
 580
 581     if (old_client_nr != new_client_nr)
 582     {
 583       // set relevant player settings and change to new player
 584
 585       old_player->connected_network = FALSE;
 586       new_player->connected_network = TRUE;
 587     }
 588
 589     player = getNetworkPlayer(old_client_nr);
 590     player->nr = new_client_nr;
 591
 592     if (old_player == local_player)             // local player switched
 593     {
 594       local_player = new_player;
 595
 596       old_player->connected_locally = FALSE;
 597       new_player->connected_locally = TRUE;
 598     }
 599   }
 600   else if (old_client_nr == first_player.nr)    // failed -- local player?
 601   {
 602     char request[100];
 603
 604     sprintf(request, "Sorry! Player %d already exists! You are player %d!",
 605             index_nr_wanted + 1, new_index_nr + 1);
 606
 607     Request(request, REQ_CONFIRM);
 608
 609     Error(ERR_NETWORK_CLIENT, "cannot switch -- you keep client # %d",
 610           new_client_nr);
 611   }
 612
 613   if (game_status == GAME_MODE_MAIN)
 614     DrawNetworkPlayers();
 615 }
 616
 617 static void Handle_OP_PLAYER_NAME(void)
 618 {
 619   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 620   char *player_name = getNetworkBufferString(read_buffer);
 621   struct NetworkClientPlayerInfo *player = getNetworkPlayer(player_nr);
 622
 623   printf("OP_PLAYER_NAME: %d\n", player_nr);
 624
 625   strncpy(player->name, player_name, MAX_PLAYER_NAME_LEN);
 626   player->name[MAX_PLAYER_NAME_LEN] = '\0';
 627
 628   Error(ERR_NETWORK_CLIENT, "client %d calls itself \"%s\"",
 629         player_nr, player->name);
 630 }
 631
 632 static void Handle_OP_PLAYER_CONNECTED(void)
 633 {
 634   struct NetworkClientPlayerInfo *player, *last_player = NULL;
 635   int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 636   int new_index_nr = new_client_nr - 1;
 637
 638   printf("OP_PLAYER_CONNECTED: %d\n", new_client_nr);
 639   Error(ERR_NETWORK_CLIENT, "new client %d connected", new_client_nr);
 640
 641   for (player = &first_player; player; player = player->next)
 642   {
 643     if (player->nr == new_client_nr)
 644       Error(ERR_EXIT, "multiplayer server sent duplicate player id");
 645
 646     last_player = player;
 647   }
 648
 649   last_player->next = player =
 650     checked_malloc(sizeof(struct NetworkClientPlayerInfo));
 651   player->nr = new_client_nr;
 652   player->name[0] = '\0';
 653   player->next = NULL;
 654
 655   stored_player[new_index_nr].connected_network = TRUE;
 656 }
 657
 658 static void Handle_OP_PLAYER_DISCONNECTED(void)
 659 {
 660   struct NetworkClientPlayerInfo *player, *player_disconnected;
 661   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 662   int index_nr = player_nr - 1;
 663
 664   printf("OP_PLAYER_DISCONNECTED: %d\n", player_nr);
 665   player_disconnected = getNetworkPlayer(player_nr);
 666   Error(ERR_NETWORK_CLIENT, "client %d (%s) disconnected",
 667         player_nr, getNetworkPlayerName(player_nr));
 668
 669   for (player = &first_player; player; player = player->next)
 670     if (player->next == player_disconnected)
 671       player->next = player_disconnected->next;
 672   free(player_disconnected);
 673
 674   stored_player[index_nr].connected_locally = FALSE;
 675   stored_player[index_nr].connected_network = FALSE;
 676
 677   if (game_status == GAME_MODE_PLAYING)
 678   {
 679     char message[100];
 680
 681     sprintf(message, "Player %d left network server! Network game stopped!",
 682             player_nr);
 683
 684     Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 685
 686     SetGameStatus(GAME_MODE_MAIN);
 687
 688     DrawMainMenu();
 689   }
 690   else if (game_status == GAME_MODE_MAIN)
 691   {
 692     DrawNetworkPlayers();
 693   }
 694 }
 695
 696 static void Handle_OP_START_PLAYING(void)
 697 {
 698   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 699   char *new_leveldir_identifier = getNetworkBufferString(read_buffer);
 700   int new_level_nr = getNetworkBuffer16BitInteger(read_buffer);
 701   unsigned int new_random_seed = getNetworkBuffer32BitInteger(read_buffer);
 702
 703   if (!strEqual(new_leveldir_identifier, network_level.leveldir_identifier))
 704   {
 705     Error(ERR_WARN, "no such level identifier: '%s'", new_leveldir_identifier);
 706
 707     stop_network_game = TRUE;
 708
 709     return;
 710   }
 711
 712   printf("OP_START_PLAYING: %d\n", player_nr);
 713   Error(ERR_NETWORK_CLIENT,
 714         "client %d starts game [level %d from level identifier '%s']\n",
 715         player_nr, new_level_nr, new_leveldir_identifier);
 716
 717   LevelDirTree *new_leveldir =
 718     getTreeInfoFromIdentifier(leveldir_first, new_leveldir_identifier);
 719
 720   if (new_leveldir != NULL)
 721   {
 722     leveldir_current = new_leveldir;
 723     level_nr = new_level_nr;
 724   }
 725
 726   // needed if level set of network game changed graphics, sounds or music
 727   ReloadCustomArtwork(0);
 728
 729   TapeErase();
 730
 731   if (network_level.use_network_level_files)
 732     LoadNetworkLevel(&network_level);
 733   else
 734     LoadLevel(level_nr);
 735
 736   StartGameActions(FALSE, setup.autorecord, new_random_seed);
 737 }
 738
 739 static void Handle_OP_PAUSE_PLAYING(void)
 740 {
 741   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 742
 743   printf("OP_PAUSE_PLAYING: %d\n", player_nr);
 744   Error(ERR_NETWORK_CLIENT, "client %d pauses game", player_nr);
 745
 746   if (game_status == GAME_MODE_PLAYING)
 747   {
 748     tape.pausing = TRUE;
 749     DrawVideoDisplay(VIDEO_STATE_PAUSE_ON, 0);
 750   }
 751 }
 752
 753 static void Handle_OP_CONTINUE_PLAYING(void)
 754 {
 755   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 756
 757   printf("OP_CONTINUE_PLAYING: %d\n", player_nr);
 758   Error(ERR_NETWORK_CLIENT, "client %d continues game", player_nr);
 759
 760   if (game_status == GAME_MODE_PLAYING)
 761   {
 762     tape.pausing = FALSE;
 763     DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF, 0);
 764   }
 765 }
 766
 767 static void Handle_OP_STOP_PLAYING(void)
 768 {
 769   int client_nr = getNetworkBuffer8BitInteger(read_buffer);
 770   int cause_for_stopping = getNetworkBuffer8BitInteger(read_buffer);
 771
 772   printf("OP_STOP_PLAYING: %d [%d]\n", client_nr, cause_for_stopping);
 773   Error(ERR_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     Error(ERR_INFO, "frame counters of client %d and server out of sync",
 812           player_nr);
 813     Error(ERR_INFO, "frame counter of client is %d", FrameCounter);
 814     Error(ERR_INFO, "frame counter of server is %d", server_frame_counter);
 815     Error(ERR_INFO, "this should not happen -- please debug");
 816
 817     stop_network_game = TRUE;
 818
 819     return;
 820   }
 821
 822   // copy valid player actions (will be set to 0 for not connected players)
 823   for (i = 0; i < MAX_PLAYERS; i++)
 824     stored_player[i].effective_action =
 825       getNetworkBuffer8BitInteger(read_buffer);
 826
 827   network_player_action_received = TRUE;
 828 }
 829
 830 static void Handle_OP_BROADCAST_MESSAGE(void)
 831 {
 832   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 833
 834   printf("OP_BROADCAST_MESSAGE: %d\n", player_nr);
 835   Error(ERR_NETWORK_CLIENT, "client %d sends message", player_nr);
 836 }
 837
 838 static void Handle_OP_LEVEL_FILE(void)
 839 {
 840   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 841   char *leveldir_identifier;
 842   char *network_level_dir;
 843   struct LevelFileInfo *file_info = &network_level.file_info;
 844   struct LevelFileInfo *tmpl_info = &network_level.tmpl_info;
 845   boolean use_custom_template;
 846
 847   setString(&network_level.leveldir_identifier, NULL);
 848   setString(&network_level.file_info.basename,  NULL);
 849   setString(&network_level.file_info.filename,  NULL);
 850   setString(&network_level.tmpl_info.basename,  NULL);
 851   setString(&network_level.tmpl_info.filename,  NULL);
 852
 853   printf("OP_LEVEL_FILE: %d\n", player_nr);
 854
 855   leveldir_identifier = getStringCopy(getNetworkBufferString(read_buffer));
 856
 857   if (hasPathSeparator(leveldir_identifier))
 858     Error(ERR_EXIT, "protocol error: invalid filename from network client");
 859
 860   InitNetworkLevelDirectory(leveldir_identifier);
 861
 862   network_level_dir   = getNetworkLevelDir(leveldir_identifier);
 863
 864   file_info->nr       = getNetworkBuffer16BitInteger(read_buffer);
 865   file_info->type     = getNetworkBuffer8BitInteger(read_buffer);
 866   file_info->packed   = getNetworkBuffer8BitInteger(read_buffer);
 867   file_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
 868   file_info->filename = getPath2(network_level_dir, file_info->basename);
 869
 870   if (hasPathSeparator(file_info->basename))
 871     Error(ERR_EXIT, "protocol error: invalid filename from network client");
 872
 873   int num_bytes = getNetworkBufferFile(read_buffer, file_info->filename);
 874
 875   // if received level file is empty, remove it (as being non-existent)
 876   if (num_bytes == 0)
 877     remove(file_info->filename);
 878
 879   use_custom_template = getNetworkBuffer8BitInteger(read_buffer);
 880   if (use_custom_template)
 881   {
 882     *tmpl_info = *file_info;
 883
 884     tmpl_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
 885     tmpl_info->filename = getPath2(network_level_dir, tmpl_info->basename);
 886
 887     if (hasPathSeparator(tmpl_info->basename))
 888       Error(ERR_EXIT, "protocol error: invalid filename from network client");
 889
 890     getNetworkBufferFile(read_buffer, tmpl_info->filename);
 891
 892     // if received level file is empty, use level template file instead
 893     if (num_bytes == 0)
 894       setString(&file_info->filename,  tmpl_info->filename);
 895   }
 896
 897   network_level.leveldir_identifier = leveldir_identifier;
 898   network_level.use_custom_template = use_custom_template;
 899
 900   // the receiving client(s) use(s) the transferred network level files
 901   network_level.use_network_level_files = TRUE;
 902
 903 #if 0
 904   printf("::: '%s'\n", leveldir_identifier);
 905   printf("::: '%d'\n", file_info->nr);
 906   printf("::: '%d'\n", file_info->type);
 907   printf("::: '%d'\n", file_info->packed);
 908   printf("::: '%s'\n", file_info->basename);
 909   printf("::: '%s'\n", file_info->filename);
 910
 911   if (use_custom_template)
 912     printf("::: '%s'\n", tmpl_info->filename);
 913 #endif
 914 }
 915
 916 static void HandleNetworkingMessage(void)
 917 {
 918   stop_network_game = FALSE;
 919
 920   initNetworkBufferForReading(read_buffer);
 921
 922   int message_type = getNetworkBuffer8BitInteger(read_buffer);
 923
 924   switch (message_type)
 925   {
 926     case OP_BAD_PROTOCOL_VERSION:
 927       Handle_OP_BAD_PROTOCOL_VERSION();
 928       break;
 929
 930     case OP_YOUR_NUMBER:
 931       Handle_OP_YOUR_NUMBER();
 932       break;
 933
 934     case OP_NUMBER_WANTED:
 935       Handle_OP_NUMBER_WANTED();
 936       break;
 937
 938     case OP_PLAYER_NAME:
 939       Handle_OP_PLAYER_NAME();
 940       break;
 941
 942     case OP_PLAYER_CONNECTED:
 943       Handle_OP_PLAYER_CONNECTED();
 944       break;
 945
 946     case OP_PLAYER_DISCONNECTED:
 947       Handle_OP_PLAYER_DISCONNECTED();
 948       break;
 949
 950     case OP_START_PLAYING:
 951       Handle_OP_START_PLAYING();
 952       break;
 953
 954     case OP_PAUSE_PLAYING:
 955       Handle_OP_PAUSE_PLAYING();
 956       break;
 957
 958     case OP_CONTINUE_PLAYING:
 959       Handle_OP_CONTINUE_PLAYING();
 960       break;
 961
 962     case OP_STOP_PLAYING:
 963       Handle_OP_STOP_PLAYING();
 964       break;
 965
 966     case OP_MOVE_PLAYER:
 967       Handle_OP_MOVE_PLAYER();
 968       break;
 969
 970     case OP_BROADCAST_MESSAGE:
 971       Handle_OP_BROADCAST_MESSAGE();
 972       break;
 973
 974     case OP_LEVEL_FILE:
 975       Handle_OP_LEVEL_FILE();
 976       break;
 977
 978     default:
 979       if (options.verbose)
 980         Error(ERR_NETWORK_CLIENT,
 981               "unknown opcode %d from server", message_type);
 982   }
 983
 984   fflush(stdout);
 985
 986   // in case of internal error, stop network game
 987   if (stop_network_game)
 988     SendToServer_StopPlaying(NETWORK_STOP_BY_ERROR);
 989 }
 990
 991 static char *HandleNetworkingPackets(void)
 992 {
 993   while (1)
 994   {
 995     // ---------- check network server for activity ----------
 996
 997     int num_active_sockets = SDLNet_CheckSockets(rfds, 0);
 998
 999     if (num_active_sockets < 0)
1000       return "Error checking network sockets!";
1001
1002     if (num_active_sockets == 0)
1003       break;    // no active sockets, stop here
1004
1005     // ---------- read packets from network server ----------
1006
1007     initNetworkBufferForReceiving(read_buffer);
1008
1009     int num_bytes = receiveNetworkBufferPacket(read_buffer, sfd);
1010
1011     if (num_bytes < 0)
1012       return "Error reading from network server!";
1013
1014     if (num_bytes == 0)
1015       return "Connection to network server lost!";
1016
1017     HandleNetworkingMessage();
1018
1019     if (stop_network_client)
1020       return stop_network_client_message;
1021   }
1022
1023   return NULL;
1024 }
1025
1026 static void FreeNetworkClientPlayerInfo(struct NetworkClientPlayerInfo *player)
1027 {
1028   if (player == NULL)
1029     return;
1030
1031   if (player->next)
1032     FreeNetworkClientPlayerInfo(player->next);
1033
1034   checked_free(player);
1035 }
1036
1037 static void HandleNetworkingDisconnect(void)
1038 {
1039   int i;
1040
1041   SDLNet_TCP_DelSocket(rfds, sfd);
1042   SDLNet_TCP_Close(sfd);
1043
1044   network_playing = FALSE;
1045
1046   network.enabled = FALSE;
1047   network.connected = FALSE;
1048
1049   setup.network_mode = FALSE;
1050
1051   for (i = 0; i < MAX_PLAYERS; i++)
1052     stored_player[i].connected_network = FALSE;
1053
1054   FreeNetworkClientPlayerInfo(first_player.next);
1055
1056   first_player.nr = 0;
1057   first_player.next = NULL;
1058 }
1059
1060 void HandleNetworking(void)
1061 {
1062   // do not handle any networking packets if request dialog is active
1063   if (game.request_active)
1064     return;
1065
1066   char *error_message = HandleNetworkingPackets();
1067
1068   if (error_message != NULL)
1069   {
1070     HandleNetworkingDisconnect();
1071
1072     if (game_status == GAME_MODE_PLAYING)
1073     {
1074       Request(error_message, REQ_CONFIRM | REQ_STAY_CLOSED);
1075
1076       SetGameStatus(GAME_MODE_MAIN);
1077
1078       DrawMainMenu();
1079     }
1080     else
1081     {
1082       Request(error_message, REQ_CONFIRM);
1083
1084       if (game_status == GAME_MODE_MAIN)
1085         ClearNetworkPlayers();
1086     }
1087   }
1088 }
1089
1090 void DisconnectFromNetworkServer(void)
1091 {
1092   DrawNetworkText_Title("Terminating Network");
1093   DrawNetworkText("Disconnecting from network server ...");
1094
1095   HandleNetworkingDisconnect();
1096
1097   DrawNetworkText_Success("Successfully disconnected!");
1098 }