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 static boolean hasPathSeparator(char *s)
 177 {
 178   return (strchr(s, '/') != NULL);
 179 }
 180
 181 static void StartNetworkServer(int port)
 182 {
 183   static int p;
 184
 185   p = port;
 186 #if defined(TARGET_SDL2)
 187   server_thread = SDL_CreateThread(NetworkServerThread,
 188                                    "NetworkServerThread", &p);
 189 #else
 190   server_thread = SDL_CreateThread(NetworkServerThread, &p);
 191 #endif
 192   network_server = TRUE;
 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       Error(ERR_EXIT, "SDLNet_AllocSocketSet() failed: %s"), SDLNet_GetError();
 220
 221     udp = SDLNet_UDP_Open(0);
 222     if(!udp)
 223       Error(ERR_EXIT, "SDLNet_UDP_Open() failed: %s", SDLNet_GetError());
 224
 225     if (SDLNet_UDP_AddSocket(udp_socket_set, udp) == -1)
 226       Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 227         SDLNet_GetError();
 228
 229     char *data_ptr = "network server UDB broadcast";
 230     int data_len = strlen(data_ptr) + 1;
 231     IPaddress ip_address;
 232
 233     SDLNet_Write32(0xffffffff, &ip_address.host);       /* 255.255.255.255 */
 234     SDLNet_Write16(port,       &ip_address.port);
 235
 236     UDPpacket packet =
 237     {
 238       -1,
 239       (Uint8 *)data_ptr,
 240       data_len,
 241       data_len,
 242       0,
 243       ip_address
 244     };
 245
 246     SDLNet_UDP_Send(udp, -1, &packet);
 247
 248     DrawNetworkText("Looking for local network server ...");
 249
 250     /* wait for any local network server to answer UDP broadcast */
 251     for (i = 0; i < 5; i++)
 252     {
 253       if (SDLNet_CheckSockets(udp_socket_set, 0) == 1)
 254       {
 255         int num_packets = SDLNet_UDP_Recv(udp, &packet);
 256
 257         if (num_packets == 1)
 258         {
 259           DrawNetworkText_Success("Network server found!");
 260
 261           server_host = SDLNet_Read32(&packet.address.host);
 262         }
 263         else
 264         {
 265           DrawNetworkText_Failed("No answer from network server!");
 266         }
 267
 268         break;
 269       }
 270       else
 271       {
 272         Delay_WithScreenUpdates(100);
 273       }
 274     }
 275
 276     if (server_host == 0)
 277       DrawNetworkText_Failed("No network server found!");
 278   }
 279
 280   rfds = SDLNet_AllocSocketSet(1);
 281
 282   if (hostname)
 283   {
 284     SDLNet_ResolveHost(&ip, hostname, port);
 285
 286     if (ip.host == INADDR_NONE)
 287     {
 288       char message[100];
 289
 290       sprintf(message, "Failed to resolve network server hostname '%s'!",
 291               hostname);
 292
 293       DrawNetworkText_Failed(message);
 294
 295       return FALSE;
 296     }
 297     else
 298       server_host = SDLNet_Read32(&ip.host);
 299
 300     DrawNetworkText("Connecting to remote host ...");
 301   }
 302   else
 303   {
 304     // if no hostname was given and no network server was auto-detected in the
 305     // local network, try to connect to a network server at the local host
 306     if (server_host == 0)
 307       server_host = 0x7f000001;                 /* 127.0.0.1 */
 308
 309     SDLNet_Write32(server_host, &ip.host);
 310     SDLNet_Write16(port,        &ip.port);
 311
 312     DrawNetworkText("Connecting to local host ...");
 313   }
 314
 315   Error(ERR_DEBUG, "trying to connect to network server at %d.%d.%d.%d ...",
 316         (server_host >> 24) & 0xff,
 317         (server_host >> 16) & 0xff,
 318         (server_host >>  8) & 0xff,
 319         (server_host >>  0) & 0xff);
 320
 321   sfd = SDLNet_TCP_Open(&ip);
 322
 323   if (sfd)
 324   {
 325     SDLNet_TCP_AddSocket(rfds, sfd);
 326
 327     DrawNetworkText_Success("Successfully connected!");
 328
 329     return TRUE;
 330   }
 331   else
 332   {
 333     DrawNetworkText_Failed("Failed to connect to network server!");
 334
 335     printf("SDLNet_TCP_Open(): %s\n", SDLNet_GetError());
 336   }
 337
 338   if (hostname)                 /* connect to specified server failed */
 339     return FALSE;
 340
 341   DrawNetworkText("Starting new local network server ...");
 342
 343   StartNetworkServer(port);
 344
 345   /* wait for server to start up and try connecting several times */
 346   for (i = 0; i < 30; i++)
 347   {
 348     if ((sfd = SDLNet_TCP_Open(&ip)))           /* connected */
 349     {
 350       DrawNetworkText_Success("Successfully connected!");
 351
 352       SDLNet_TCP_AddSocket(rfds, sfd);
 353       return TRUE;
 354     }
 355
 356     Delay_WithScreenUpdates(100);
 357   }
 358
 359   DrawNetworkText_Failed("Failed to connect to network server!");
 360
 361   /* when reaching this point, connect to newly started server has failed */
 362   return FALSE;
 363 }
 364
 365 void SendToServer_PlayerName(char *player_name)
 366 {
 367   initNetworkBufferForWriting(write_buffer, OP_PLAYER_NAME, 0);
 368
 369   putNetworkBufferString(write_buffer, player_name);
 370
 371   SendNetworkBufferToServer(write_buffer);
 372
 373   Error(ERR_NETWORK_CLIENT, "you set your player name to \"%s\"", player_name);
 374 }
 375
 376 void SendToServer_ProtocolVersion(void)
 377 {
 378   initNetworkBufferForWriting(write_buffer, OP_PROTOCOL_VERSION, 0);
 379
 380   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MAJOR);
 381   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_MINOR);
 382   putNetworkBuffer8BitInteger(write_buffer, PROTOCOL_VERSION_PATCH);
 383
 384   SendNetworkBufferToServer(write_buffer);
 385 }
 386
 387 void SendToServer_NrWanted(int nr_wanted)
 388 {
 389   initNetworkBufferForWriting(write_buffer, OP_NUMBER_WANTED, 0);
 390
 391   putNetworkBuffer8BitInteger(write_buffer, nr_wanted);
 392
 393   SendNetworkBufferToServer(write_buffer);
 394 }
 395
 396 void SendToServer_LevelFile(void)
 397 {
 398   initNetworkBufferForWriting(write_buffer, OP_LEVEL_FILE, 0);
 399
 400   putNetworkBufferString(      write_buffer, leveldir_current->identifier);
 401   putNetworkBuffer16BitInteger(write_buffer, level.file_info.nr);
 402   putNetworkBuffer8BitInteger( write_buffer, level.file_info.type);
 403   putNetworkBuffer8BitInteger( write_buffer, level.file_info.packed);
 404   putNetworkBufferString(      write_buffer, level.file_info.basename);
 405   putNetworkBufferFile(        write_buffer, level.file_info.filename);
 406   putNetworkBuffer8BitInteger( write_buffer, level.use_custom_template);
 407
 408   if (level.use_custom_template)
 409   {
 410     putNetworkBufferString(write_buffer, level_template.file_info.basename);
 411     putNetworkBufferFile(  write_buffer, level_template.file_info.filename);
 412   }
 413
 414   SendNetworkBufferToServer(write_buffer);
 415
 416   setString(&network_level.leveldir_identifier, leveldir_current->identifier);
 417
 418   /* the sending client does not use network level files (but the real ones) */
 419   network_level.use_network_level_files = FALSE;
 420
 421 #if 0
 422   printf("::: '%s'\n", leveldir_current->identifier);
 423   printf("::: '%d'\n", level.file_info.nr);
 424   printf("::: '%d'\n", level.file_info.type);
 425   printf("::: '%d'\n", level.file_info.packed);
 426   printf("::: '%s'\n", level.file_info.basename);
 427   printf("::: '%s'\n", level.file_info.filename);
 428
 429   if (level.use_custom_template)
 430     printf("::: '%s'\n", level_template.file_info.filename);
 431 #endif
 432 }
 433
 434 void SendToServer_StartPlaying(void)
 435 {
 436   unsigned int new_random_seed = InitRND(level.random_seed);
 437
 438   initNetworkBufferForWriting(write_buffer, OP_START_PLAYING, 0);
 439
 440   putNetworkBufferString(      write_buffer, leveldir_current->identifier);
 441   putNetworkBuffer16BitInteger(write_buffer, level_nr);
 442   putNetworkBuffer32BitInteger(write_buffer, new_random_seed);
 443
 444   SendNetworkBufferToServer(write_buffer);
 445 }
 446
 447 void SendToServer_PausePlaying(void)
 448 {
 449   initNetworkBufferForWriting(write_buffer, OP_PAUSE_PLAYING, 0);
 450
 451   SendNetworkBufferToServer(write_buffer);
 452 }
 453
 454 void SendToServer_ContinuePlaying(void)
 455 {
 456   initNetworkBufferForWriting(write_buffer, OP_CONTINUE_PLAYING, 0);
 457
 458   SendNetworkBufferToServer(write_buffer);
 459 }
 460
 461 void SendToServer_StopPlaying(int cause_for_stopping)
 462 {
 463   initNetworkBufferForWriting(write_buffer, OP_STOP_PLAYING, 0);
 464
 465   putNetworkBuffer8BitInteger(write_buffer, cause_for_stopping);
 466
 467   SendNetworkBufferToServer(write_buffer);
 468 }
 469
 470 void SendToServer_MovePlayer(byte player_action)
 471 {
 472   initNetworkBufferForWriting(write_buffer, OP_MOVE_PLAYER, 0);
 473
 474   putNetworkBuffer8BitInteger(write_buffer, player_action);
 475
 476   SendNetworkBufferToServer(write_buffer);
 477 }
 478
 479 static void Handle_OP_BAD_PROTOCOL_VERSION(void)
 480 {
 481   int protocol_version_major = getNetworkBuffer8BitInteger(read_buffer);
 482   int protocol_version_minor = getNetworkBuffer8BitInteger(read_buffer);
 483
 484   Error(ERR_WARN, "protocol version mismatch");
 485   Error(ERR_WARN, "server expects %d.%d.x instead of %d.%d.%d",
 486         protocol_version_major,
 487         protocol_version_minor,
 488         PROTOCOL_VERSION_MAJOR,
 489         PROTOCOL_VERSION_MINOR,
 490         PROTOCOL_VERSION_PATCH);
 491
 492   sprintf(stop_network_client_message, "Network protocol version mismatch! Server expects version %d.%d.x instead of %d.%d.%d!",
 493           protocol_version_major,
 494           protocol_version_minor,
 495           PROTOCOL_VERSION_MAJOR,
 496           PROTOCOL_VERSION_MINOR,
 497           PROTOCOL_VERSION_PATCH);
 498
 499   stop_network_client = TRUE;
 500 }
 501
 502 static void Handle_OP_YOUR_NUMBER(void)
 503 {
 504   int old_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 505   int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 506   int new_index_nr = new_client_nr - 1;
 507   struct PlayerInfo *old_local_player = local_player;
 508   struct PlayerInfo *new_local_player = &stored_player[new_index_nr];
 509
 510   printf("OP_YOUR_NUMBER: %d\n", old_client_nr);
 511   first_player.nr = new_client_nr;
 512
 513   if (old_local_player != new_local_player)
 514   {
 515     /* set relevant player settings and change to new player */
 516
 517     local_player = new_local_player;
 518
 519     old_local_player->connected_locally = FALSE;
 520     new_local_player->connected_locally = TRUE;
 521
 522     old_local_player->connected_network = FALSE;
 523     new_local_player->connected_network = TRUE;
 524   }
 525
 526   if (first_player.nr > MAX_PLAYERS)
 527     Error(ERR_EXIT, "sorry, more than %d players not allowed", MAX_PLAYERS);
 528
 529   Error(ERR_NETWORK_CLIENT, "you get client # %d", new_client_nr);
 530
 531   stored_player[new_index_nr].connected_network = TRUE;
 532 }
 533
 534 static void Handle_OP_NUMBER_WANTED(void)
 535 {
 536   int old_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
 537   int client_nr_wanted = getNetworkBuffer8BitInteger(read_buffer);
 538   int new_client_nr    = getNetworkBuffer8BitInteger(read_buffer);
 539   int old_index_nr = old_client_nr - 1;
 540   int new_index_nr = new_client_nr - 1;
 541   int index_nr_wanted = client_nr_wanted - 1;
 542   struct PlayerInfo *old_player = &stored_player[old_index_nr];
 543   struct PlayerInfo *new_player = &stored_player[new_index_nr];
 544
 545   printf("OP_NUMBER_WANTED: %d\n", old_client_nr);
 546
 547   if (new_client_nr == client_nr_wanted)        /* switching succeeded */
 548   {
 549     struct NetworkClientPlayerInfo *player;
 550
 551     if (old_client_nr != client_nr_wanted)      /* client's nr has changed */
 552       Error(ERR_NETWORK_CLIENT, "client %d switches to # %d",
 553             old_client_nr, new_client_nr);
 554     else if (old_client_nr == first_player.nr)  /* local player keeps his nr */
 555       Error(ERR_NETWORK_CLIENT, "keeping client # %d", new_client_nr);
 556
 557     if (old_client_nr != new_client_nr)
 558     {
 559       /* set relevant player settings and change to new player */
 560
 561       old_player->connected_network = FALSE;
 562       new_player->connected_network = TRUE;
 563     }
 564
 565     player = getNetworkPlayer(old_client_nr);
 566     player->nr = new_client_nr;
 567
 568     if (old_player == local_player)             /* local player switched */
 569     {
 570       local_player = new_player;
 571
 572       old_player->connected_locally = FALSE;
 573       new_player->connected_locally = TRUE;
 574     }
 575   }
 576   else if (old_client_nr == first_player.nr)    /* failed -- local player? */
 577   {
 578     char request[100];
 579
 580     sprintf(request, "Sorry! Player %d already exists! You are player %d!",
 581             index_nr_wanted + 1, new_index_nr + 1);
 582
 583     Request(request, REQ_CONFIRM);
 584
 585     Error(ERR_NETWORK_CLIENT, "cannot switch -- you keep client # %d",
 586           new_client_nr);
 587   }
 588
 589   if (game_status == GAME_MODE_MAIN)
 590     DrawNetworkPlayers();
 591 }
 592
 593 static void Handle_OP_PLAYER_NAME(void)
 594 {
 595   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 596   char *player_name = getNetworkBufferString(read_buffer);
 597   struct NetworkClientPlayerInfo *player = getNetworkPlayer(player_nr);
 598
 599   printf("OP_PLAYER_NAME: %d\n", player_nr);
 600
 601   strncpy(player->name, player_name, MAX_PLAYER_NAME_LEN);
 602   player->name[MAX_PLAYER_NAME_LEN] = '\0';
 603
 604   Error(ERR_NETWORK_CLIENT, "client %d calls itself \"%s\"",
 605         player_nr, player->name);
 606 }
 607
 608 static void Handle_OP_PLAYER_CONNECTED(void)
 609 {
 610   struct NetworkClientPlayerInfo *player, *last_player = NULL;
 611   int new_client_nr = getNetworkBuffer8BitInteger(read_buffer);
 612   int new_index_nr = new_client_nr - 1;
 613
 614   printf("OP_PLAYER_CONNECTED: %d\n", new_client_nr);
 615   Error(ERR_NETWORK_CLIENT, "new client %d connected", new_client_nr);
 616
 617   for (player = &first_player; player; player = player->next)
 618   {
 619     if (player->nr == new_client_nr)
 620       Error(ERR_EXIT, "multiplayer server sent duplicate player id");
 621
 622     last_player = player;
 623   }
 624
 625   last_player->next = player =
 626     checked_malloc(sizeof(struct NetworkClientPlayerInfo));
 627   player->nr = new_client_nr;
 628   player->name[0] = '\0';
 629   player->next = NULL;
 630
 631   stored_player[new_index_nr].connected_network = TRUE;
 632 }
 633
 634 static void Handle_OP_PLAYER_DISCONNECTED(void)
 635 {
 636   struct NetworkClientPlayerInfo *player, *player_disconnected;
 637   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 638   int index_nr = player_nr - 1;
 639
 640   printf("OP_PLAYER_DISCONNECTED: %d\n", player_nr);
 641   player_disconnected = getNetworkPlayer(player_nr);
 642   Error(ERR_NETWORK_CLIENT, "client %d (%s) disconnected",
 643         player_nr, getNetworkPlayerName(player_nr));
 644
 645   for (player = &first_player; player; player = player->next)
 646     if (player->next == player_disconnected)
 647       player->next = player_disconnected->next;
 648   free(player_disconnected);
 649
 650   stored_player[index_nr].connected_locally = FALSE;
 651   stored_player[index_nr].connected_network = FALSE;
 652
 653   if (game_status == GAME_MODE_PLAYING)
 654   {
 655     char message[100];
 656
 657     sprintf(message, "Player %d left network server! Network game stopped!",
 658             player_nr);
 659
 660     Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 661
 662     SetGameStatus(GAME_MODE_MAIN);
 663
 664     DrawMainMenu();
 665   }
 666   else if (game_status == GAME_MODE_MAIN)
 667   {
 668     DrawNetworkPlayers();
 669   }
 670 }
 671
 672 static void Handle_OP_START_PLAYING(void)
 673 {
 674   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 675   char *new_leveldir_identifier = getNetworkBufferString(read_buffer);
 676   int new_level_nr = getNetworkBuffer16BitInteger(read_buffer);
 677   unsigned int new_random_seed = getNetworkBuffer32BitInteger(read_buffer);
 678
 679   if (!strEqual(new_leveldir_identifier, network_level.leveldir_identifier))
 680   {
 681     Error(ERR_WARN, "no such level identifier: '%s'", new_leveldir_identifier);
 682
 683     stop_network_game = TRUE;
 684
 685     return;
 686   }
 687
 688   printf("OP_START_PLAYING: %d\n", player_nr);
 689   Error(ERR_NETWORK_CLIENT,
 690         "client %d starts game [level %d from level identifier '%s']\n",
 691         player_nr, new_level_nr, new_leveldir_identifier);
 692
 693   LevelDirTree *new_leveldir =
 694     getTreeInfoFromIdentifier(leveldir_first, new_leveldir_identifier);
 695
 696   if (new_leveldir != NULL)
 697   {
 698     leveldir_current = new_leveldir;
 699     level_nr = new_level_nr;
 700   }
 701
 702   /* needed if level set of network game changed graphics, sounds or music */
 703   ReloadCustomArtwork(0);
 704
 705   TapeErase();
 706
 707   if (network_level.use_network_level_files)
 708     LoadNetworkLevel(&network_level);
 709   else
 710     LoadLevel(level_nr);
 711
 712   StartGameActions(FALSE, setup.autorecord, new_random_seed);
 713 }
 714
 715 static void Handle_OP_PAUSE_PLAYING(void)
 716 {
 717   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 718
 719   printf("OP_PAUSE_PLAYING: %d\n", player_nr);
 720   Error(ERR_NETWORK_CLIENT, "client %d pauses game", player_nr);
 721
 722   if (game_status == GAME_MODE_PLAYING)
 723   {
 724     tape.pausing = TRUE;
 725     DrawVideoDisplay(VIDEO_STATE_PAUSE_ON, 0);
 726   }
 727 }
 728
 729 static void Handle_OP_CONTINUE_PLAYING(void)
 730 {
 731   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 732
 733   printf("OP_CONTINUE_PLAYING: %d\n", player_nr);
 734   Error(ERR_NETWORK_CLIENT, "client %d continues game", player_nr);
 735
 736   if (game_status == GAME_MODE_PLAYING)
 737   {
 738     tape.pausing = FALSE;
 739     DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF, 0);
 740   }
 741 }
 742
 743 static void Handle_OP_STOP_PLAYING(void)
 744 {
 745   int client_nr = getNetworkBuffer8BitInteger(read_buffer);
 746   int cause_for_stopping = getNetworkBuffer8BitInteger(read_buffer);
 747
 748   printf("OP_STOP_PLAYING: %d [%d]\n", client_nr, cause_for_stopping);
 749   Error(ERR_NETWORK_CLIENT, "client %d stops game [%d]",
 750         client_nr, cause_for_stopping);
 751
 752   if (game_status == GAME_MODE_PLAYING)
 753   {
 754     int index_nr = client_nr - 1;
 755     struct PlayerInfo *client_player = &stored_player[index_nr];
 756     boolean stopped_by_remote_player = (!client_player->connected_locally);
 757     char message[100];
 758
 759     if (cause_for_stopping == NETWORK_STOP_BY_PLAYER)
 760       sprintf(message, "Network game stopped by player %d!", client_nr);
 761     else
 762       sprintf(message, (cause_for_stopping == NETWORK_STOP_BY_ERROR ?
 763                         "Network game stopped due to internal error!" :
 764                         "Network game stopped!"));
 765
 766     if (cause_for_stopping != NETWORK_STOP_BY_PLAYER ||
 767         stopped_by_remote_player)
 768       Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 769
 770     SetGameStatus(GAME_MODE_MAIN);
 771
 772     DrawMainMenu();
 773   }
 774 }
 775
 776 static void Handle_OP_MOVE_PLAYER(void)
 777 {
 778   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 779   int server_frame_counter = getNetworkBuffer32BitInteger(read_buffer);
 780   int i;
 781
 782   if (!network_playing)
 783     return;
 784
 785   if (server_frame_counter != FrameCounter)
 786   {
 787     Error(ERR_INFO, "frame counters of client %d and server out of sync",
 788           player_nr);
 789     Error(ERR_INFO, "frame counter of client is %d", FrameCounter);
 790     Error(ERR_INFO, "frame counter of server is %d", server_frame_counter);
 791     Error(ERR_INFO, "this should not happen -- please debug");
 792
 793     stop_network_game = TRUE;
 794
 795     return;
 796   }
 797
 798   /* copy valid player actions (will be set to 0 for not connected players) */
 799   for (i = 0; i < MAX_PLAYERS; i++)
 800     stored_player[i].effective_action =
 801       getNetworkBuffer8BitInteger(read_buffer);
 802
 803   network_player_action_received = TRUE;
 804 }
 805
 806 static void Handle_OP_BROADCAST_MESSAGE(void)
 807 {
 808   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 809
 810   printf("OP_BROADCAST_MESSAGE: %d\n", player_nr);
 811   Error(ERR_NETWORK_CLIENT, "client %d sends message", player_nr);
 812 }
 813
 814 static void Handle_OP_LEVEL_FILE(void)
 815 {
 816   int player_nr = getNetworkBuffer8BitInteger(read_buffer);
 817   char *leveldir_identifier;
 818   char *network_level_dir;
 819   struct LevelFileInfo *file_info = &network_level.file_info;
 820   struct LevelFileInfo *tmpl_info = &network_level.tmpl_info;
 821   boolean use_custom_template;
 822
 823   setString(&network_level.leveldir_identifier, NULL);
 824   setString(&network_level.file_info.basename,  NULL);
 825   setString(&network_level.file_info.filename,  NULL);
 826   setString(&network_level.tmpl_info.basename,  NULL);
 827   setString(&network_level.tmpl_info.filename,  NULL);
 828
 829   printf("OP_LEVEL_FILE: %d\n", player_nr);
 830
 831   leveldir_identifier = getStringCopy(getNetworkBufferString(read_buffer));
 832
 833   if (hasPathSeparator(leveldir_identifier))
 834     Error(ERR_EXIT, "protocol error: invalid filename from network client");
 835
 836   InitNetworkLevelDirectory(leveldir_identifier);
 837
 838   network_level_dir   = getNetworkLevelDir(leveldir_identifier);
 839
 840   file_info->nr       = getNetworkBuffer16BitInteger(read_buffer);
 841   file_info->type     = getNetworkBuffer8BitInteger(read_buffer);
 842   file_info->packed   = getNetworkBuffer8BitInteger(read_buffer);
 843   file_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
 844   file_info->filename = getPath2(network_level_dir, file_info->basename);
 845
 846   if (hasPathSeparator(file_info->basename))
 847     Error(ERR_EXIT, "protocol error: invalid filename from network client");
 848
 849   getNetworkBufferFile(read_buffer, file_info->filename);
 850
 851   use_custom_template = getNetworkBuffer8BitInteger(read_buffer);
 852   if (use_custom_template)
 853   {
 854     *tmpl_info = *file_info;
 855
 856     tmpl_info->basename = getStringCopy(getNetworkBufferString(read_buffer));
 857     tmpl_info->filename = getPath2(network_level_dir, tmpl_info->basename);
 858
 859     if (hasPathSeparator(tmpl_info->basename))
 860       Error(ERR_EXIT, "protocol error: invalid filename from network client");
 861
 862     getNetworkBufferFile(read_buffer, tmpl_info->filename);
 863   }
 864
 865   network_level.leveldir_identifier = leveldir_identifier;
 866   network_level.use_custom_template = use_custom_template;
 867
 868   /* the receiving client(s) use(s) the transferred network level files */
 869   network_level.use_network_level_files = TRUE;
 870
 871 #if 0
 872   printf("::: '%s'\n", leveldir_identifier);
 873   printf("::: '%d'\n", file_info->nr);
 874   printf("::: '%d'\n", file_info->type);
 875   printf("::: '%d'\n", file_info->packed);
 876   printf("::: '%s'\n", file_info->basename);
 877   printf("::: '%s'\n", file_info->filename);
 878
 879   if (use_custom_template)
 880     printf("::: '%s'\n", tmpl_info->filename);
 881 #endif
 882 }
 883
 884 static void HandleNetworkingMessage(void)
 885 {
 886   stop_network_game = FALSE;
 887
 888   initNetworkBufferForReading(read_buffer);
 889
 890   int message_type = getNetworkBuffer8BitInteger(read_buffer);
 891
 892   switch (message_type)
 893   {
 894     case OP_BAD_PROTOCOL_VERSION:
 895       Handle_OP_BAD_PROTOCOL_VERSION();
 896       break;
 897
 898     case OP_YOUR_NUMBER:
 899       Handle_OP_YOUR_NUMBER();
 900       break;
 901
 902     case OP_NUMBER_WANTED:
 903       Handle_OP_NUMBER_WANTED();
 904       break;
 905
 906     case OP_PLAYER_NAME:
 907       Handle_OP_PLAYER_NAME();
 908       break;
 909
 910     case OP_PLAYER_CONNECTED:
 911       Handle_OP_PLAYER_CONNECTED();
 912       break;
 913
 914     case OP_PLAYER_DISCONNECTED:
 915       Handle_OP_PLAYER_DISCONNECTED();
 916       break;
 917
 918     case OP_START_PLAYING:
 919       Handle_OP_START_PLAYING();
 920       break;
 921
 922     case OP_PAUSE_PLAYING:
 923       Handle_OP_PAUSE_PLAYING();
 924       break;
 925
 926     case OP_CONTINUE_PLAYING:
 927       Handle_OP_CONTINUE_PLAYING();
 928       break;
 929
 930     case OP_STOP_PLAYING:
 931       Handle_OP_STOP_PLAYING();
 932       break;
 933
 934     case OP_MOVE_PLAYER:
 935       Handle_OP_MOVE_PLAYER();
 936       break;
 937
 938     case OP_BROADCAST_MESSAGE:
 939       Handle_OP_BROADCAST_MESSAGE();
 940       break;
 941
 942     case OP_LEVEL_FILE:
 943       Handle_OP_LEVEL_FILE();
 944       break;
 945
 946     default:
 947       if (options.verbose)
 948         Error(ERR_NETWORK_CLIENT,
 949               "unknown opcode %d from server", message_type);
 950   }
 951
 952   fflush(stdout);
 953
 954   /* in case of internal error, stop network game */
 955   if (stop_network_game)
 956     SendToServer_StopPlaying(NETWORK_STOP_BY_ERROR);
 957 }
 958
 959 static char *HandleNetworkingPackets(void)
 960 {
 961   while (1)
 962   {
 963     /* ---------- check network server for activity ---------- */
 964
 965     int num_active_sockets = SDLNet_CheckSockets(rfds, 0);
 966
 967     if (num_active_sockets < 0)
 968       return "Error checking network sockets!";
 969
 970     if (num_active_sockets == 0)
 971       break;    // no active sockets, stop here
 972
 973     /* ---------- read packets from network server ---------- */
 974
 975     initNetworkBufferForReceiving(read_buffer);
 976
 977     int num_bytes = receiveNetworkBufferPacket(read_buffer, sfd);
 978
 979     if (num_bytes < 0)
 980       return "Error reading from network server!";
 981
 982     if (num_bytes == 0)
 983       return "Connection to network server lost!";
 984
 985     HandleNetworkingMessage();
 986
 987     if (stop_network_client)
 988       return stop_network_client_message;
 989   }
 990
 991   return NULL;
 992 }
 993
 994 static void FreeNetworkClientPlayerInfo(struct NetworkClientPlayerInfo *player)
 995 {
 996   if (player == NULL)
 997     return;
 998
 999   if (player->next)
1000     FreeNetworkClientPlayerInfo(player->next);
1001
1002   checked_free(player);
1003 }
1004
1005 static void HandleNetworkingDisconnect(void)
1006 {
1007   int i;
1008
1009   SDLNet_TCP_DelSocket(rfds, sfd);
1010   SDLNet_TCP_Close(sfd);
1011
1012   network_playing = FALSE;
1013
1014   network.enabled = FALSE;
1015   network.connected = FALSE;
1016
1017   setup.network_mode = FALSE;
1018
1019   for (i = 0; i < MAX_PLAYERS; i++)
1020     stored_player[i].connected_network = FALSE;
1021
1022   FreeNetworkClientPlayerInfo(first_player.next);
1023
1024   first_player.nr = 0;
1025   first_player.next = NULL;
1026 }
1027
1028 void HandleNetworking(void)
1029 {
1030   char *error_message = HandleNetworkingPackets();
1031
1032   if (error_message != NULL)
1033   {
1034     HandleNetworkingDisconnect();
1035
1036     if (game_status == GAME_MODE_PLAYING)
1037     {
1038       Request(error_message, REQ_CONFIRM | REQ_STAY_CLOSED);
1039
1040       SetGameStatus(GAME_MODE_MAIN);
1041
1042       DrawMainMenu();
1043     }
1044     else
1045     {
1046       Request(error_message, REQ_CONFIRM);
1047
1048       if (game_status == GAME_MODE_MAIN)
1049         ClearNetworkPlayers();
1050     }
1051   }
1052 }
1053
1054 void DisconnectFromNetworkServer(void)
1055 {
1056   DrawNetworkText_Title("Terminating Network");
1057   DrawNetworkText("Disconnecting from network server ...");
1058
1059   HandleNetworkingDisconnect();
1060
1061   DrawNetworkText_Success("Successfully disconnected!");
1062
1063   /* short time to recognize result of network initialization */
1064   Delay_WithScreenUpdates(1000);
1065 }