src/network.c

   1 // ============================================================================
   2 // Rocks'n'Diamonds - McDuffin Strikes Back!
   3 // ----------------------------------------------------------------------------
   4 // (c) 1995-2014 by Artsoft Entertainment
   5 //                  Holger Schemel
   6 //                  info@artsoft.org
   7 //                  http://www.artsoft.org/
   8 // ----------------------------------------------------------------------------
   9 // network.c
  10 // ============================================================================
  11
  12 #include <signal.h>
  13 #include <sys/time.h>
  14
  15 #include "libgame/libgame.h"
  16
  17 #include "network.h"
  18 #include "netserv.h"
  19 #include "main.h"
  20 #include "game.h"
  21 #include "tape.h"
  22 #include "files.h"
  23 #include "tools.h"
  24 #include "screens.h"
  25
  26 struct NetworkClientPlayerInfo
  27 {
  28   byte nr;
  29   char name[MAX_PLAYER_NAME_LEN + 1];
  30   struct NetworkClientPlayerInfo *next;
  31 };
  32
  33 static struct NetworkClientPlayerInfo first_player =
  34 {
  35   0,
  36   EMPTY_PLAYER_NAME,
  37   NULL
  38 };
  39
  40 /* server stuff */
  41
  42 static TCPsocket sfd;           /* TCP server socket */
  43 static UDPsocket udp;           /* UDP server socket */
  44 static SDLNet_SocketSet rfds;   /* socket set */
  45
  46 static byte realbuffer[512];
  47 static byte readbuffer[MAX_BUFFER_SIZE], writbuffer[MAX_BUFFER_SIZE];
  48 static byte *buffer = realbuffer + 4;
  49 static int nread = 0, nwrite = 0;
  50 static boolean stop_network_game = FALSE;
  51 static boolean stop_network_client = FALSE;
  52 static char stop_network_client_message[MAX_OUTPUT_LINESIZE + 1];
  53
  54 static void DrawNetworkTextExt(char *message, int font_nr, boolean initialize)
  55 {
  56   static int xpos = 0, ypos = 0;
  57   static int max_line_width = 0;
  58   int font_width = getFontWidth(font_nr);
  59   int font_height = getFontHeight(font_nr);
  60   int ypos_1 = 120;
  61   int ypos_2 = 150;
  62
  63   if (initialize)
  64   {
  65     if (game_status == GAME_MODE_LOADING)
  66     {
  67       max_line_width = WIN_XSIZE;
  68
  69       xpos = (max_line_width - getTextWidth(message, font_nr)) / 2;
  70       ypos = ypos_1;
  71
  72       DrawText(xpos, ypos, message, font_nr);
  73
  74       xpos = 0;
  75       ypos = ypos_2;
  76     }
  77     else
  78     {
  79       max_line_width = SXSIZE;
  80
  81       DrawTextSCentered(ypos_1, font_nr, message);
  82
  83       /* calculate offset to x position caused by rounding */
  84       int max_chars_per_line = max_line_width / font_width;
  85       int xoffset = (max_line_width - max_chars_per_line * font_width) / 2;
  86
  87       xpos = SX + xoffset;
  88       ypos = SY + ypos_2;
  89     }
  90
  91     Error(ERR_DEBUG, "========== %s ==========", message);
  92   }
  93   else
  94   {
  95     int max_chars_per_line = max_line_width / font_width;
  96     int max_lines_per_text = 10;
  97     int num_lines_spacing = (font_nr == FC_YELLOW ? 1 : 3);
  98     int num_lines_printed = DrawTextBuffer(xpos, ypos, message, font_nr,
  99                                            max_chars_per_line, -1,
 100                                            max_lines_per_text, 0, -1,
 101                                            TRUE, TRUE, FALSE);
 102
 103     ypos += (num_lines_printed + num_lines_spacing) * font_height;
 104
 105     Error(ERR_DEBUG, "%s", message);
 106   }
 107
 108   BackToFront();
 109 }
 110
 111 static void DrawNetworkText(char *message)
 112 {
 113   DrawNetworkTextExt(message, FC_YELLOW, FALSE);
 114 }
 115
 116 static void DrawNetworkText_Success(char *message)
 117 {
 118   DrawNetworkTextExt(message, FC_GREEN, FALSE);
 119 }
 120
 121 static void DrawNetworkText_Failed(char *message)
 122 {
 123   DrawNetworkTextExt(message, FC_RED, FALSE);
 124 }
 125
 126 static void DrawNetworkText_Title(char *message)
 127 {
 128   DrawNetworkTextExt(message, FC_GREEN, TRUE);
 129 }
 130
 131 static void SendBufferToServer(int size)
 132 {
 133   if (!network.enabled)
 134     return;
 135
 136   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
 137   realbuffer[3] = (byte)size;
 138   buffer[0] = 0;
 139
 140   if (nwrite + 4 + size >= MAX_BUFFER_SIZE)
 141     Error(ERR_EXIT, "internal error: network send buffer overflow");
 142
 143   memcpy(writbuffer + nwrite, realbuffer, 4 + size);
 144   nwrite += 4 + size;
 145
 146   /* directly send the buffer to the network server */
 147   SDLNet_TCP_Send(sfd, writbuffer, nwrite);
 148   nwrite = 0;
 149 }
 150
 151 struct NetworkClientPlayerInfo *getNetworkPlayer(int player_nr)
 152 {
 153   struct NetworkClientPlayerInfo *player = NULL;
 154
 155   for (player = &first_player; player; player = player->next)
 156     if (player->nr == player_nr)
 157       break;
 158
 159   if (player == NULL)   /* should not happen */
 160     Error(ERR_EXIT, "protocol error: reference to non-existing player %d",
 161           player_nr);
 162
 163   return player;
 164 }
 165
 166 char *getNetworkPlayerName(int player_nr)
 167 {
 168   struct NetworkClientPlayerInfo *player;
 169
 170   if (player_nr == 0)
 171     return("the network game server");
 172   else if (player_nr == first_player.nr)
 173     return("you");
 174   else
 175     for (player = &first_player; player; player = player->next)
 176       if (player->nr == player_nr && strlen(player->name) > 0)
 177         return(player->name);
 178
 179   return(EMPTY_PLAYER_NAME);
 180 }
 181
 182 static void StartNetworkServer(int port)
 183 {
 184   static int p;
 185
 186   p = port;
 187 #if defined(TARGET_SDL2)
 188   server_thread = SDL_CreateThread(NetworkServerThread,
 189                                    "NetworkServerThread", &p);
 190 #else
 191   server_thread = SDL_CreateThread(NetworkServerThread, &p);
 192 #endif
 193   network_server = TRUE;
 194 }
 195
 196 boolean ConnectToServer(char *hostname, int port)
 197 {
 198   IPaddress ip;
 199   int server_host = 0;
 200   int i;
 201
 202   DrawNetworkText_Title("Initializing Network");
 203
 204   if (port == 0)
 205     port = DEFAULT_SERVER_PORT;
 206
 207   if (hostname == NULL)
 208   {
 209     // if no hostname given, try to auto-detect network server in local network
 210     // by doing a UDP broadcast on the network server port and wait for answer
 211
 212     SDLNet_SocketSet udp_socket_set = SDLNet_AllocSocketSet(1);
 213     if (!udp_socket_set)
 214       Error(ERR_EXIT, "SDLNet_AllocSocketSet() failed: %s"), SDLNet_GetError();
 215
 216     udp = SDLNet_UDP_Open(0);
 217     if(!udp)
 218       Error(ERR_EXIT, "SDLNet_UDP_Open() failed: %s", SDLNet_GetError());
 219
 220     if (SDLNet_UDP_AddSocket(udp_socket_set, udp) == -1)
 221       Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 222         SDLNet_GetError();
 223
 224     char *data_ptr = "network server UDB broadcast";
 225     int data_len = strlen(data_ptr) + 1;
 226     IPaddress ip_address;
 227
 228     SDLNet_Write32(0xffffffff, &ip_address.host);       /* 255.255.255.255 */
 229     SDLNet_Write16(port,       &ip_address.port);
 230
 231     UDPpacket packet =
 232     {
 233       -1,
 234       (Uint8 *)data_ptr,
 235       data_len,
 236       data_len,
 237       0,
 238       ip_address
 239     };
 240
 241     SDLNet_UDP_Send(udp, -1, &packet);
 242
 243     DrawNetworkText("Looking for local network server ...");
 244
 245     /* wait for any local network server to answer UDP broadcast */
 246     for (i = 0; i < 5; i++)
 247     {
 248       if (SDLNet_CheckSockets(udp_socket_set, 0) == 1)
 249       {
 250         int num_packets = SDLNet_UDP_Recv(udp, &packet);
 251
 252         if (num_packets == 1)
 253         {
 254           DrawNetworkText_Success("Network server found!");
 255
 256           server_host = SDLNet_Read32(&packet.address.host);
 257         }
 258         else
 259         {
 260           DrawNetworkText_Failed("No answer from network server!");
 261         }
 262
 263         break;
 264       }
 265       else
 266       {
 267         Delay_WithScreenUpdates(100);
 268       }
 269     }
 270
 271     if (server_host == 0)
 272       DrawNetworkText_Failed("No network server found!");
 273   }
 274
 275   rfds = SDLNet_AllocSocketSet(1);
 276
 277   if (hostname)
 278   {
 279     SDLNet_ResolveHost(&ip, hostname, port);
 280
 281     if (ip.host == INADDR_NONE)
 282       Error(ERR_EXIT, "cannot locate host '%s'", hostname);
 283     else
 284       server_host = SDLNet_Read32(&ip.host);
 285
 286     DrawNetworkText("Connecting to remote host ...");
 287   }
 288   else
 289   {
 290     // if no hostname was given and no network server was auto-detected in the
 291     // local network, try to connect to a network server at the local host
 292     if (server_host == 0)
 293       server_host = 0x7f000001;                 /* 127.0.0.1 */
 294
 295     SDLNet_Write32(server_host, &ip.host);
 296     SDLNet_Write16(port,        &ip.port);
 297
 298     DrawNetworkText("Connecting to local host ...");
 299   }
 300
 301   Error(ERR_DEBUG, "trying to connect to network server at %d.%d.%d.%d ...",
 302         (server_host >> 24) & 0xff,
 303         (server_host >> 16) & 0xff,
 304         (server_host >>  8) & 0xff,
 305         (server_host >>  0) & 0xff);
 306
 307   sfd = SDLNet_TCP_Open(&ip);
 308
 309   if (sfd)
 310   {
 311     SDLNet_TCP_AddSocket(rfds, sfd);
 312
 313     DrawNetworkText_Success("Successfully connected!");
 314
 315     return TRUE;
 316   }
 317   else
 318   {
 319     DrawNetworkText_Failed("Failed to connect to network server!");
 320
 321     printf("SDLNet_TCP_Open(): %s\n", SDLNet_GetError());
 322   }
 323
 324   if (hostname)                 /* connect to specified server failed */
 325     return FALSE;
 326
 327   DrawNetworkText("Starting new local network server ...");
 328
 329   StartNetworkServer(port);
 330
 331   /* wait for server to start up and try connecting several times */
 332   for (i = 0; i < 30; i++)
 333   {
 334     if ((sfd = SDLNet_TCP_Open(&ip)))           /* connected */
 335     {
 336       DrawNetworkText_Success("Successfully connected!");
 337
 338       SDLNet_TCP_AddSocket(rfds, sfd);
 339       return TRUE;
 340     }
 341
 342     Delay_WithScreenUpdates(100);
 343   }
 344
 345   DrawNetworkText_Failed("Failed to connect to network server!");
 346
 347   /* when reaching this point, connect to newly started server has failed */
 348   return FALSE;
 349 }
 350
 351 void SendToServer_PlayerName(char *player_name)
 352 {
 353   int len_player_name = strlen(player_name);
 354
 355   buffer[1] = OP_PLAYER_NAME;
 356   memcpy(&buffer[2], player_name, len_player_name);
 357   SendBufferToServer(2 + len_player_name);
 358   Error(ERR_NETWORK_CLIENT, "you set your player name to \"%s\"", player_name);
 359 }
 360
 361 void SendToServer_ProtocolVersion()
 362 {
 363   buffer[1] = OP_PROTOCOL_VERSION;
 364   buffer[2] = PROTOCOL_VERSION_1;
 365   buffer[3] = PROTOCOL_VERSION_2;
 366   buffer[4] = PROTOCOL_VERSION_3;
 367
 368   SendBufferToServer(5);
 369 }
 370
 371 void SendToServer_NrWanted(int nr_wanted)
 372 {
 373   buffer[1] = OP_NUMBER_WANTED;
 374   buffer[2] = nr_wanted;
 375
 376   SendBufferToServer(3);
 377 }
 378
 379 void SendToServer_StartPlaying()
 380 {
 381   unsigned int new_random_seed = InitRND(level.random_seed);
 382
 383   int dummy = 0;                /* !!! HAS NO MEANING ANYMORE !!! */
 384                                 /* the name of the level must be enough */
 385
 386   buffer[1] = OP_START_PLAYING;
 387   buffer[2] = (byte)(level_nr >> 8);
 388   buffer[3] = (byte)(level_nr & 0xff);
 389   buffer[4] = (byte)(dummy >> 8);
 390   buffer[5] = (byte)(dummy & 0xff);
 391
 392   buffer[6] = (unsigned char)((new_random_seed >> 24) & 0xff);
 393   buffer[7] = (unsigned char)((new_random_seed >> 16) & 0xff);
 394   buffer[8] = (unsigned char)((new_random_seed >>  8) & 0xff);
 395   buffer[9] = (unsigned char)((new_random_seed >>  0) & 0xff);
 396
 397   strcpy((char *)&buffer[10], leveldir_current->identifier);
 398
 399   SendBufferToServer(10 + strlen(leveldir_current->identifier) + 1);
 400 }
 401
 402 void SendToServer_PausePlaying()
 403 {
 404   buffer[1] = OP_PAUSE_PLAYING;
 405
 406   SendBufferToServer(2);
 407 }
 408
 409 void SendToServer_ContinuePlaying()
 410 {
 411   buffer[1] = OP_CONTINUE_PLAYING;
 412
 413   SendBufferToServer(2);
 414 }
 415
 416 void SendToServer_StopPlaying(int cause_for_stopping)
 417 {
 418   buffer[1] = OP_STOP_PLAYING;
 419   buffer[2] = cause_for_stopping;
 420
 421   SendBufferToServer(3);
 422 }
 423
 424 void SendToServer_MovePlayer(byte player_action)
 425 {
 426   buffer[1] = OP_MOVE_PLAYER;
 427   buffer[2] = player_action;
 428
 429   SendBufferToServer(3);
 430 }
 431
 432 static void Handle_OP_BAD_PROTOCOL_VERSION()
 433 {
 434   Error(ERR_WARN, "protocol version mismatch");
 435   Error(ERR_WARN, "server expects %d.%d.x instead of %d.%d.%d",
 436         buffer[2], buffer[3],
 437         PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 438
 439   sprintf(stop_network_client_message, "Network protocol version mismatch! Server expects version %d.%d.x instead of %d.%d.%d!",
 440           buffer[2], buffer[3],
 441           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 442
 443   stop_network_client = TRUE;
 444 }
 445
 446 static void Handle_OP_YOUR_NUMBER()
 447 {
 448   int new_client_nr = buffer[2];
 449   int new_index_nr = new_client_nr - 1;
 450   struct PlayerInfo *old_local_player = local_player;
 451   struct PlayerInfo *new_local_player = &stored_player[new_index_nr];
 452
 453   printf("OP_YOUR_NUMBER: %d\n", buffer[0]);
 454   first_player.nr = new_client_nr;
 455
 456   if (old_local_player != new_local_player)
 457   {
 458     /* set relevant player settings and change to new player */
 459
 460     local_player = new_local_player;
 461
 462     old_local_player->connected_locally = FALSE;
 463     new_local_player->connected_locally = TRUE;
 464
 465     old_local_player->connected_network = FALSE;
 466     new_local_player->connected_network = TRUE;
 467   }
 468
 469   if (first_player.nr > MAX_PLAYERS)
 470     Error(ERR_EXIT, "sorry, more than %d players not allowed", MAX_PLAYERS);
 471
 472   Error(ERR_NETWORK_CLIENT, "you get client # %d", new_client_nr);
 473
 474   stored_player[new_index_nr].connected_network = TRUE;
 475 }
 476
 477 static void Handle_OP_NUMBER_WANTED()
 478 {
 479   int client_nr_wanted = buffer[2];
 480   int old_client_nr = buffer[0];
 481   int new_client_nr = buffer[3];
 482   int old_index_nr = old_client_nr - 1;
 483   int new_index_nr = new_client_nr - 1;
 484   int index_nr_wanted = client_nr_wanted - 1;
 485   struct PlayerInfo *old_player = &stored_player[old_index_nr];
 486   struct PlayerInfo *new_player = &stored_player[new_index_nr];
 487
 488   printf("OP_NUMBER_WANTED: %d\n", buffer[0]);
 489
 490   if (new_client_nr == client_nr_wanted)        /* switching succeeded */
 491   {
 492     struct NetworkClientPlayerInfo *player;
 493
 494     if (old_client_nr != client_nr_wanted)      /* client's nr has changed */
 495       Error(ERR_NETWORK_CLIENT, "client %d switches to # %d",
 496             old_client_nr, new_client_nr);
 497     else if (old_client_nr == first_player.nr)  /* local player keeps his nr */
 498       Error(ERR_NETWORK_CLIENT, "keeping client # %d", new_client_nr);
 499
 500     if (old_client_nr != new_client_nr)
 501     {
 502       /* set relevant player settings and change to new player */
 503
 504       old_player->connected_network = FALSE;
 505       new_player->connected_network = TRUE;
 506     }
 507
 508     player = getNetworkPlayer(old_client_nr);
 509     player->nr = new_client_nr;
 510
 511     if (old_player == local_player)             /* local player switched */
 512     {
 513       local_player = new_player;
 514
 515       old_player->connected_locally = FALSE;
 516       new_player->connected_locally = TRUE;
 517     }
 518   }
 519   else if (old_client_nr == first_player.nr)    /* failed -- local player? */
 520   {
 521     char request[100];
 522
 523     sprintf(request, "Sorry! Player %d already exists! You are player %d!",
 524             index_nr_wanted + 1, new_index_nr + 1);
 525
 526     Request(request, REQ_CONFIRM);
 527
 528     Error(ERR_NETWORK_CLIENT, "cannot switch -- you keep client # %d",
 529           new_client_nr);
 530   }
 531
 532   if (game_status == GAME_MODE_MAIN)
 533     DrawNetworkPlayers();
 534 }
 535
 536 static void Handle_OP_PLAYER_NAME(unsigned int len)
 537 {
 538   struct NetworkClientPlayerInfo *player;
 539   int player_nr = (int)buffer[0];
 540
 541   printf("OP_PLAYER_NAME: %d\n", player_nr);
 542   player = getNetworkPlayer(player_nr);
 543   buffer[len] = 0;
 544   Error(ERR_NETWORK_CLIENT, "client %d calls itself \"%s\"",
 545         buffer[0], &buffer[2]);
 546   strncpy(player->name, (char *)&buffer[2], MAX_PLAYER_NAME_LEN);
 547 }
 548
 549 static void Handle_OP_PLAYER_CONNECTED()
 550 {
 551   struct NetworkClientPlayerInfo *player, *last_player = NULL;
 552   int new_client_nr = (int)buffer[0];
 553   int new_index_nr = new_client_nr - 1;
 554
 555   printf("OP_PLAYER_CONNECTED: %d\n", new_client_nr);
 556   Error(ERR_NETWORK_CLIENT, "new client %d connected", new_client_nr);
 557
 558   for (player = &first_player; player; player = player->next)
 559   {
 560     if (player->nr == new_client_nr)
 561       Error(ERR_EXIT, "multiplayer server sent duplicate player id");
 562
 563     last_player = player;
 564   }
 565
 566   last_player->next = player =
 567     checked_malloc(sizeof(struct NetworkClientPlayerInfo));
 568   player->nr = new_client_nr;
 569   player->name[0] = '\0';
 570   player->next = NULL;
 571
 572   stored_player[new_index_nr].connected_network = TRUE;
 573 }
 574
 575 static void Handle_OP_PLAYER_DISCONNECTED()
 576 {
 577   struct NetworkClientPlayerInfo *player, *player_disconnected;
 578   int player_nr = (int)buffer[0];
 579   int index_nr = player_nr - 1;
 580
 581   printf("OP_PLAYER_DISCONNECTED: %d\n", player_nr);
 582   player_disconnected = getNetworkPlayer(player_nr);
 583   Error(ERR_NETWORK_CLIENT, "client %d (%s) disconnected",
 584         player_nr, getNetworkPlayerName(buffer[0]));
 585
 586   for (player = &first_player; player; player = player->next)
 587     if (player->next == player_disconnected)
 588       player->next = player_disconnected->next;
 589   free(player_disconnected);
 590
 591   stored_player[index_nr].connected_locally = FALSE;
 592   stored_player[index_nr].connected_network = FALSE;
 593
 594   if (game_status == GAME_MODE_PLAYING)
 595   {
 596     char message[100];
 597
 598     sprintf(message, "Player %d left network server! Network game stopped!",
 599             player_nr);
 600
 601     Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 602
 603     SetGameStatus(GAME_MODE_MAIN);
 604
 605     DrawMainMenu();
 606   }
 607   else if (game_status == GAME_MODE_MAIN)
 608   {
 609     DrawNetworkPlayers();
 610   }
 611 }
 612
 613 static void Handle_OP_START_PLAYING()
 614 {
 615   LevelDirTree *new_leveldir;
 616   int new_level_nr;
 617   unsigned int new_random_seed;
 618   char *new_leveldir_identifier;
 619
 620   new_level_nr = (buffer[2] << 8) + buffer[3];
 621   new_random_seed =
 622     (buffer[6] << 24) | (buffer[7] << 16) | (buffer[8] << 8) | (buffer[9]);
 623   new_leveldir_identifier = (char *)&buffer[10];
 624
 625   new_leveldir = getTreeInfoFromIdentifier(leveldir_first,
 626                                            new_leveldir_identifier);
 627   if (new_leveldir == NULL)
 628   {
 629     Error(ERR_WARN, "no such level identifier: '%s'", new_leveldir_identifier);
 630
 631     stop_network_game = TRUE;
 632
 633     return;
 634   }
 635
 636   printf("OP_START_PLAYING: %d\n", buffer[0]);
 637   Error(ERR_NETWORK_CLIENT,
 638         "client %d starts game [level %d from level identifier '%s']\n",
 639         buffer[0], new_level_nr, new_leveldir->identifier);
 640
 641   leveldir_current = new_leveldir;
 642   level_nr = new_level_nr;
 643
 644   TapeErase();
 645   LoadTape(level_nr);
 646   LoadLevel(level_nr);
 647
 648   StartGameActions(FALSE, setup.autorecord, new_random_seed);
 649 }
 650
 651 static void Handle_OP_PAUSE_PLAYING()
 652 {
 653   printf("OP_PAUSE_PLAYING: %d\n", buffer[0]);
 654   Error(ERR_NETWORK_CLIENT, "client %d pauses game", buffer[0]);
 655
 656   if (game_status == GAME_MODE_PLAYING)
 657   {
 658     tape.pausing = TRUE;
 659     DrawVideoDisplay(VIDEO_STATE_PAUSE_ON,0);
 660   }
 661 }
 662
 663 static void Handle_OP_CONTINUE_PLAYING()
 664 {
 665   printf("OP_CONTINUE_PLAYING: %d\n", buffer[0]);
 666   Error(ERR_NETWORK_CLIENT, "client %d continues game", buffer[0]);
 667
 668   if (game_status == GAME_MODE_PLAYING)
 669   {
 670     tape.pausing = FALSE;
 671     DrawVideoDisplay(VIDEO_STATE_PAUSE_OFF,0);
 672   }
 673 }
 674
 675 static void Handle_OP_STOP_PLAYING()
 676 {
 677   printf("OP_STOP_PLAYING: %d [%d]\n", buffer[0], buffer[2]);
 678   Error(ERR_NETWORK_CLIENT, "client %d stops game [%d]", buffer[0], buffer[2]);
 679
 680   if (game_status == GAME_MODE_PLAYING)
 681   {
 682     int client_nr = buffer[0];
 683     int index_nr = client_nr - 1;
 684     struct PlayerInfo *client_player = &stored_player[index_nr];
 685     boolean stopped_by_remote_player = (!client_player->connected_locally);
 686     char message[100];
 687
 688     sprintf(message, (buffer[2] == NETWORK_STOP_BY_PLAYER ?
 689                       "Network game stopped by player %d!" :
 690                       buffer[2] == NETWORK_STOP_BY_ERROR ?
 691                       "Network game stopped due to internal error!" :
 692                       "Network game stopped!"), client_nr);
 693
 694     if (buffer[2] != NETWORK_STOP_BY_PLAYER || stopped_by_remote_player)
 695       Request(message, REQ_CONFIRM | REQ_STAY_CLOSED);
 696
 697     SetGameStatus(GAME_MODE_MAIN);
 698
 699     DrawMainMenu();
 700   }
 701 }
 702
 703 static void Handle_OP_MOVE_PLAYER(unsigned int len)
 704 {
 705   int server_frame_counter;
 706   int i;
 707
 708   if (!network_playing)
 709     return;
 710
 711   server_frame_counter =
 712     (buffer[2] << 24) | (buffer[3] << 16) | (buffer[4] << 8) | (buffer[5]);
 713
 714   if (server_frame_counter != FrameCounter)
 715   {
 716     Error(ERR_INFO, "client and servers frame counters out of sync");
 717     Error(ERR_INFO, "frame counter of client is %d", FrameCounter);
 718     Error(ERR_INFO, "frame counter of server is %d", server_frame_counter);
 719     Error(ERR_INFO, "this should not happen -- please debug");
 720
 721     stop_network_game = TRUE;
 722
 723     return;
 724   }
 725
 726   /* copy valid player actions */
 727   for (i = 0; i < MAX_PLAYERS; i++)
 728     stored_player[i].effective_action =
 729       (i < len - 6 ? buffer[6 + i] : 0);
 730
 731   network_player_action_received = TRUE;
 732 }
 733
 734 static void HandleNetworkingMessages()
 735 {
 736   unsigned int message_length;
 737
 738   stop_network_game = FALSE;
 739
 740   while (nread >= 4 && nread >= 4 + readbuffer[3])
 741   {
 742     message_length = readbuffer[3];
 743     if (readbuffer[0] || readbuffer[1] || readbuffer[2])
 744       Error(ERR_EXIT, "wrong network server line length");
 745
 746     memcpy(buffer, &readbuffer[4], message_length);
 747     nread -= 4 + message_length;
 748     memmove(readbuffer, readbuffer + 4 + message_length, nread);
 749
 750     switch (buffer[1])
 751     {
 752       case OP_BAD_PROTOCOL_VERSION:
 753         Handle_OP_BAD_PROTOCOL_VERSION();
 754         break;
 755
 756       case OP_YOUR_NUMBER:
 757         Handle_OP_YOUR_NUMBER();
 758         break;
 759
 760       case OP_NUMBER_WANTED:
 761         Handle_OP_NUMBER_WANTED();
 762         break;
 763
 764       case OP_PLAYER_NAME:
 765         Handle_OP_PLAYER_NAME(message_length);
 766         break;
 767
 768       case OP_PLAYER_CONNECTED:
 769         Handle_OP_PLAYER_CONNECTED();
 770         break;
 771
 772       case OP_PLAYER_DISCONNECTED:
 773         Handle_OP_PLAYER_DISCONNECTED();
 774         break;
 775
 776       case OP_START_PLAYING:
 777         Handle_OP_START_PLAYING();
 778         break;
 779
 780       case OP_PAUSE_PLAYING:
 781         Handle_OP_PAUSE_PLAYING();
 782         break;
 783
 784       case OP_CONTINUE_PLAYING:
 785         Handle_OP_CONTINUE_PLAYING();
 786         break;
 787
 788       case OP_STOP_PLAYING:
 789         Handle_OP_STOP_PLAYING();
 790         break;
 791
 792       case OP_MOVE_PLAYER:
 793         Handle_OP_MOVE_PLAYER(message_length);
 794         break;
 795
 796       case OP_BROADCAST_MESSAGE:
 797         printf("OP_BROADCAST_MESSAGE: %d\n", buffer[0]);
 798         Error(ERR_NETWORK_CLIENT, "client %d sends message", buffer[0]);
 799         break;
 800     }
 801   }
 802
 803   fflush(stdout);
 804
 805   /* in case of internal error, stop network game */
 806   if (stop_network_game)
 807     SendToServer_StopPlaying(NETWORK_STOP_BY_ERROR);
 808 }
 809
 810 static char *HandleNetworkingPackets()
 811 {
 812   while (1)
 813   {
 814     /* ---------- check network server for activity ---------- */
 815
 816     int num_active_sockets = SDLNet_CheckSockets(rfds, 1);
 817
 818     if (num_active_sockets < 0)
 819       return "Error checking network sockets!";
 820
 821     if (num_active_sockets == 0)
 822       break;    // no active sockets, stop here
 823
 824     /* ---------- read packets from network server ---------- */
 825
 826     int num_bytes = SDLNet_TCP_Recv(sfd, readbuffer + nread, 1);
 827
 828     if (num_bytes < 0)
 829       return "Error reading from network server!";
 830
 831     if (num_bytes == 0)
 832       return "Connection to network server lost!";
 833
 834     nread += num_bytes;
 835
 836     HandleNetworkingMessages();
 837
 838     if (stop_network_client)
 839       return stop_network_client_message;
 840   }
 841
 842   return NULL;
 843 }
 844
 845 static void FreeNetworkClientPlayerInfo(struct NetworkClientPlayerInfo *player)
 846 {
 847   if (player == NULL)
 848     return;
 849
 850   if (player->next)
 851     FreeNetworkClientPlayerInfo(player->next);
 852
 853   checked_free(player);
 854 }
 855
 856 static void HandleNetworkingDisconnect()
 857 {
 858   int i;
 859
 860   SDLNet_TCP_DelSocket(rfds, sfd);
 861   SDLNet_TCP_Close(sfd);
 862
 863   network_playing = FALSE;
 864
 865   network.enabled = FALSE;
 866   network.connected = FALSE;
 867
 868   setup.network_mode = FALSE;
 869
 870   for (i = 0; i < MAX_PLAYERS; i++)
 871     stored_player[i].connected_network = FALSE;
 872
 873   FreeNetworkClientPlayerInfo(first_player.next);
 874
 875   first_player.nr = 0;
 876   first_player.next = NULL;
 877 }
 878
 879 void HandleNetworking()
 880 {
 881   char *error_message = HandleNetworkingPackets();
 882
 883   if (error_message != NULL)
 884   {
 885     HandleNetworkingDisconnect();
 886
 887     if (game_status == GAME_MODE_PLAYING)
 888     {
 889       Request(error_message, REQ_CONFIRM | REQ_STAY_CLOSED);
 890
 891       SetGameStatus(GAME_MODE_MAIN);
 892
 893       DrawMainMenu();
 894     }
 895     else
 896     {
 897       Request(error_message, REQ_CONFIRM);
 898
 899       if (game_status == GAME_MODE_MAIN)
 900         ClearNetworkPlayers();
 901     }
 902   }
 903 }
 904
 905 void DisconnectFromNetworkServer()
 906 {
 907   DrawNetworkText_Title("Terminating Network");
 908   DrawNetworkText("Disconnecting from network server ...");
 909
 910   HandleNetworkingDisconnect();
 911
 912   DrawNetworkText_Success("Successfully disconnected!");
 913
 914   /* short time to recognize result of network initialization */
 915   Delay_WithScreenUpdates(1000);
 916 }