src/netserv.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 // netserv.c
  10 // ============================================================================
  11
  12 #include <fcntl.h>
  13 #include <sys/time.h>
  14 #include <signal.h>
  15 #include <errno.h>
  16
  17 #include "libgame/libgame.h"
  18
  19 #include "netserv.h"
  20 #include "main.h"
  21
  22
  23 static int clients = 0;
  24 static int onceonly = 0;
  25
  26 struct NetworkServerPlayerInfo
  27 {
  28   TCPsocket fd;
  29   char player_name[16];
  30   unsigned char number;
  31   struct NetworkServerPlayerInfo *next;
  32   char active;
  33   char introduced;
  34   unsigned char readbuffer[MAX_BUFFER_SIZE];
  35   unsigned char writbuffer[MAX_BUFFER_SIZE];
  36   int nread, nwrite;
  37   byte action;
  38   boolean action_received;
  39 };
  40
  41 static struct NetworkServerPlayerInfo *first_player = NULL;
  42
  43 #define NEXT(player) ((player)->next ? (player)->next : first_player)
  44
  45 /* TODO: peer address */
  46 static TCPsocket lfd;           /* listening TCP socket */
  47 static UDPsocket udp;           /* listening UDP socket */
  48 static SDLNet_SocketSet fds;    /* socket set */
  49
  50 static unsigned char realbuffer[512], *buffer = realbuffer + 4;
  51
  52 static int interrupt;
  53
  54 static unsigned int ServerFrameCounter = 0;
  55
  56 static void addtobuffer(struct NetworkServerPlayerInfo *player,
  57                         unsigned char *b, int len)
  58 {
  59   if (player->nwrite + len >= MAX_BUFFER_SIZE)
  60     Error(ERR_EXIT_NETWORK_SERVER,
  61           "internal error: network send buffer overflow");
  62
  63   memcpy(player->writbuffer + player->nwrite, b, len);
  64   player->nwrite += len;
  65 }
  66
  67 static void flushuser(struct NetworkServerPlayerInfo *player)
  68 {
  69   if (player->nwrite)
  70   {
  71     SDLNet_TCP_Send(player->fd, player->writbuffer, player->nwrite);
  72
  73     player->nwrite = 0;
  74   }
  75 }
  76
  77 static void broadcast(struct NetworkServerPlayerInfo *except,
  78                       int len, int activeonly)
  79 {
  80   struct NetworkServerPlayerInfo *player;
  81
  82   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  83   realbuffer[3] = (unsigned char)len;
  84   for (player = first_player; player; player = player->next)
  85     if (player != except && player->introduced &&
  86         (player->active || !activeonly))
  87       addtobuffer(player, realbuffer, 4 + len);
  88 }
  89
  90 static void sendtoone(struct NetworkServerPlayerInfo *to, int len)
  91 {
  92   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  93   realbuffer[3] = (unsigned char)len;
  94   addtobuffer(to, realbuffer, 4 + len);
  95 }
  96
  97 static void RemovePlayer(struct NetworkServerPlayerInfo *player)
  98 {
  99   struct NetworkServerPlayerInfo *v;
 100
 101   if (options.verbose)
 102     Error(ERR_NETWORK_SERVER, "dropping client %d (%s)",
 103           player->number, player->player_name);
 104
 105   if (player == first_player)
 106     first_player = player->next;
 107   else
 108   {
 109     for (v = first_player; v; v = v->next)
 110     {
 111       if (v->next && v->next == player)
 112       {
 113         v->next = player->next;
 114         break;
 115       }
 116     }
 117   }
 118
 119   SDLNet_TCP_DelSocket(fds, player->fd);
 120   SDLNet_TCP_Close(player->fd);
 121
 122   if (player->introduced)
 123   {
 124     buffer[0] = player->number;
 125     buffer[1] = OP_PLAYER_DISCONNECTED;
 126     broadcast(player, 2, 0);
 127   }
 128
 129   free(player);
 130   clients--;
 131
 132   if (onceonly && clients == 0)
 133   {
 134     if (options.verbose)
 135     {
 136       Error(ERR_NETWORK_SERVER, "no clients left");
 137       Error(ERR_NETWORK_SERVER, "aborting");
 138     }
 139     exit(0);
 140   }
 141 }
 142
 143 static void AddPlayer(TCPsocket fd)
 144 {
 145   struct NetworkServerPlayerInfo *player, *v;
 146   unsigned char nxn;
 147   boolean again = TRUE;
 148
 149   player = checked_malloc(sizeof (struct NetworkServerPlayerInfo));
 150
 151   player->fd = fd;
 152   player->player_name[0] = 0;
 153   player->next = first_player;
 154   player->active = 0;
 155   player->nread = 0;
 156   player->nwrite = 0;
 157   player->introduced = 0;
 158   player->action = 0;
 159   player->action_received = FALSE;
 160
 161   SDLNet_TCP_AddSocket(fds, fd);
 162
 163   first_player = player;
 164
 165   nxn = 1;
 166
 167   while (again)
 168   {
 169     again = FALSE;
 170     v = player->next;
 171
 172     while (v)
 173     {
 174       if (v->number == nxn)
 175       {
 176         nxn++;
 177
 178         again = TRUE;
 179         break;
 180       }
 181       v = v->next;
 182     }
 183   }
 184
 185   player->number = nxn;
 186   clients++;
 187
 188   buffer[0] = 0;
 189   buffer[1] = OP_YOUR_NUMBER;
 190   buffer[2] = player->number;
 191   sendtoone(player, 3);
 192 }
 193
 194 static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player,
 195                                        unsigned int len)
 196 {
 197   if (len != 5 ||
 198       buffer[2] != PROTOCOL_VERSION_1 ||
 199       buffer[3] != PROTOCOL_VERSION_2)
 200   {
 201     if (options.verbose)
 202       Error(ERR_NETWORK_SERVER,
 203             "client %d (%s) has wrong protocol version %d.%d.%d",
 204             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 205
 206     buffer[0] = 0;
 207     buffer[1] = OP_BAD_PROTOCOL_VERSION;
 208     buffer[2] = PROTOCOL_VERSION_1;
 209     buffer[3] = PROTOCOL_VERSION_2;
 210     buffer[4] = PROTOCOL_VERSION_3;
 211     sendtoone(player, 5);
 212     flushuser(player);
 213
 214     RemovePlayer(player);
 215     interrupt = 1;
 216   }
 217   else
 218   {
 219     if (options.verbose)
 220       Error(ERR_NETWORK_SERVER,
 221             "client %d (%s) uses protocol version %d.%d.%d",
 222             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 223   }
 224 }
 225
 226 static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 227 {
 228   struct NetworkServerPlayerInfo *v;
 229   int client_nr = player->number;
 230   int nr_wanted = buffer[2];
 231   int nr_is_free = 1;
 232
 233   if (options.verbose)
 234       Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
 235             player->number, player->player_name, nr_wanted);
 236
 237   for (v = first_player; v; v = v->next)
 238   {
 239     if (v->number == nr_wanted)
 240     {
 241       nr_is_free = 0;
 242       break;
 243     }
 244   }
 245
 246   if (options.verbose)
 247   {
 248     if (nr_is_free)
 249       Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
 250             player->number, player->player_name, nr_wanted);
 251     else if (player->number == nr_wanted)
 252       Error(ERR_NETWORK_SERVER, "client %d (%s) already has # %d",
 253             player->number, player->player_name, nr_wanted);
 254     else
 255       Error(ERR_NETWORK_SERVER,
 256             "client %d (%s) cannot switch (client %d already exists)",
 257             player->number, player->player_name, nr_wanted);
 258   }
 259
 260   if (nr_is_free)
 261     player->number = nr_wanted;
 262
 263   buffer[0] = client_nr;
 264   buffer[1] = OP_NUMBER_WANTED;
 265   buffer[2] = nr_wanted;
 266   buffer[3] = player->number;
 267
 268   /*
 269   sendtoone(player, 4);
 270   */
 271
 272   broadcast(NULL, 4, 0);
 273 }
 274
 275 static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player,
 276                                   unsigned int len)
 277 {
 278   struct NetworkServerPlayerInfo *v;
 279   int i;
 280
 281   if (len>16)
 282     len=16;
 283   memcpy(player->player_name, &buffer[2], len-2);
 284   player->player_name[len-2] = 0;
 285   for (i = 0; i < len - 2; i++)
 286   {
 287     if (player->player_name[i] < ' ' ||
 288         ((unsigned char)(player->player_name[i]) > 0x7e &&
 289          (unsigned char)(player->player_name[i]) <= 0xa0))
 290     {
 291       player->player_name[i] = 0;
 292       break;
 293     }
 294   }
 295
 296   if (!player->introduced)
 297   {
 298     buffer[0] = player->number;
 299     buffer[1] = OP_PLAYER_CONNECTED;
 300     broadcast(player, 2, 0);
 301   }
 302
 303   if (options.verbose)
 304     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 305           player->number, player->player_name);
 306   buffer[1] = OP_PLAYER_NAME;
 307   broadcast(player, len, 0);
 308
 309   if (!player->introduced)
 310   {
 311     for (v = first_player; v; v = v->next)
 312     {
 313       if (v != player && v->introduced)
 314       {
 315         buffer[0] = v->number;
 316         buffer[1] = OP_PLAYER_CONNECTED;
 317         sendtoone(player, 2);
 318         buffer[1] = OP_PLAYER_NAME;
 319         memcpy(&buffer[2], v->player_name, 14);
 320         sendtoone(player, 2+strlen(v->player_name));
 321       }
 322     }
 323   }
 324
 325   player->introduced = 1;
 326 }
 327
 328 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 329 {
 330   struct NetworkServerPlayerInfo *v, *w;
 331
 332   if (options.verbose)
 333     Error(ERR_NETWORK_SERVER,
 334           "client %d (%s) starts game [level %d from leveldir %d (%s)]",
 335           player->number, player->player_name,
 336           (buffer[2] << 8) + buffer[3],
 337           (buffer[4] << 8) + buffer[5],
 338           &buffer[10]);
 339
 340   for (w = first_player; w; w = w->next)
 341     if (w->introduced)
 342       w->active = 1;
 343
 344   /* reset frame counter */
 345   ServerFrameCounter = 0;
 346
 347   Error(ERR_NETWORK_SERVER, "resetting ServerFrameCounter to 0");
 348
 349   /* reset player actions */
 350   for (v = first_player; v; v = v->next)
 351   {
 352     v->action = 0;
 353     v->action_received = FALSE;
 354   }
 355
 356   broadcast(NULL, 10 + strlen((char *)&buffer[10])+1, 0);
 357 }
 358
 359 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 360 {
 361   if (options.verbose)
 362     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 363           player->number, player->player_name);
 364   broadcast(NULL, 2, 0);
 365 }
 366
 367 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 368 {
 369   if (options.verbose)
 370     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 371           player->number, player->player_name);
 372   broadcast(NULL, 2, 0);
 373 }
 374
 375 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 376 {
 377   int cause_for_stopping = buffer[2];
 378
 379   if (options.verbose)
 380     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game [%d]",
 381           player->number, player->player_name, cause_for_stopping);
 382   broadcast(NULL, 3, 0);
 383 }
 384
 385 static void Handle_OP_MOVE_PLAYER(struct NetworkServerPlayerInfo *player)
 386 {
 387   struct NetworkServerPlayerInfo *v;
 388   int last_client_nr = 0;
 389   int i;
 390
 391   /* store player action */
 392   for (v = first_player; v; v = v->next)
 393   {
 394     if (v->number == player->number)
 395     {
 396       v->action = buffer[2];
 397       v->action_received = TRUE;
 398     }
 399   }
 400
 401   /* check if server received action from each player */
 402   for (v = first_player; v; v = v->next)
 403   {
 404     if (!v->action_received)
 405       return;
 406
 407     if (v->number > last_client_nr)
 408       last_client_nr = v->number;
 409   }
 410
 411   /* initialize all player actions to zero */
 412   for (i = 0; i < last_client_nr; i++)
 413     buffer[6 + i] = 0;
 414
 415   /* broadcast actions of all players to all players */
 416   for (v = first_player; v; v = v->next)
 417   {
 418     buffer[6 + v->number-1] = v->action;
 419     v->action = 0;
 420     v->action_received = FALSE;
 421   }
 422
 423   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 424   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 425   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 426   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 427
 428   broadcast(NULL, 6 + last_client_nr, 0);
 429
 430   ServerFrameCounter++;
 431 }
 432
 433 void ExitNetworkServer(int exit_value)
 434 {
 435   Error(ERR_NETWORK_SERVER, "exiting network server");
 436
 437   exit(exit_value);
 438 }
 439
 440 /* the following is not used for a standalone server;
 441    the pointer points to an integer containing the port-number */
 442 int NetworkServerThread(void *ptr)
 443 {
 444   NetworkServer(*((int *) ptr), 0);
 445
 446   /* should never be reached */
 447   return 0;
 448 }
 449
 450 void NetworkServer(int port, int serveronly)
 451 {
 452   struct NetworkServerPlayerInfo *player;
 453   int r;
 454   unsigned int len;
 455   IPaddress ip;
 456
 457 #if defined(PLATFORM_UNIX) && !defined(PLATFORM_NEXT)
 458   struct sigaction sact;
 459 #endif
 460
 461   if (port == 0)
 462     port = DEFAULT_SERVER_PORT;
 463
 464   // if only running the network server, exit on Ctrl-C
 465   if (serveronly)
 466     signal(SIGINT, ExitNetworkServer);
 467
 468   if (!serveronly)
 469     onceonly = 1;
 470
 471 #if defined(PLATFORM_UNIX)
 472 #if defined(PLATFORM_NEXT)
 473   signal(SIGPIPE, SIG_IGN);
 474 #else
 475   sact.sa_handler = SIG_IGN;
 476   sigemptyset(&sact.sa_mask);
 477   sact.sa_flags = 0;
 478   sigaction(SIGPIPE, &sact, NULL);
 479 #endif
 480 #endif
 481
 482   if (SDLNet_ResolveHost(&ip, NULL, port) == -1)
 483     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_ResolveHost() failed: %s",
 484           SDLNet_GetError());
 485
 486   if ((fds = SDLNet_AllocSocketSet(MAX_PLAYERS + 1 + 1)) == NULL)
 487     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_AllocSocketSet() failed: %s"),
 488       SDLNet_GetError();
 489
 490   if ((lfd = SDLNet_TCP_Open(&ip)) == NULL)
 491     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_Open() failed: %s"),
 492       SDLNet_GetError();
 493
 494   if (SDLNet_TCP_AddSocket(fds, lfd) == -1)
 495     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 496       SDLNet_GetError();
 497
 498   if ((udp = SDLNet_UDP_Open(port)) == NULL)
 499     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_UDP_Open() failed: %s",
 500           SDLNet_GetError());
 501
 502   if (SDLNet_UDP_AddSocket(fds, udp) == -1)
 503     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 504       SDLNet_GetError();
 505
 506   if (options.verbose)
 507   {
 508     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 509     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 510           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 511   }
 512
 513   while (1)
 514   {
 515     interrupt = 0;
 516
 517     for (player = first_player; player; player = player->next)
 518       flushuser(player);
 519
 520     // wait for 100 ms for activity on open network sockets
 521     if (SDLNet_CheckSockets(fds, 100) < 1)
 522       continue;
 523
 524     /* accept incoming TCP connections */
 525     if (SDLNet_SocketReady(lfd))
 526     {
 527       Error(ERR_DEBUG, "got TCP packet");
 528
 529       TCPsocket newsock;
 530
 531       newsock = SDLNet_TCP_Accept(lfd);
 532
 533       if (newsock)
 534         AddPlayer(newsock);
 535     }
 536
 537     /* accept incoming UDP packets */
 538     if (SDLNet_SocketReady(udp))
 539     {
 540       Error(ERR_DEBUG, "got UDP packet");
 541
 542       static UDPpacket packet;
 543
 544       int num_packets = SDLNet_UDP_Recv(udp, &packet);
 545
 546       if (num_packets == 1)
 547       {
 548         // bounce packet
 549         SDLNet_UDP_Send(udp, -1, &packet);
 550       }
 551     }
 552
 553     player = first_player;
 554
 555     while (player && !interrupt)
 556     {
 557       if (SDLNet_SocketReady(player->fd))
 558       {
 559         /* read only 1 byte, because SDLNet blocks when we want more than is
 560            in the buffer */
 561         r = SDLNet_TCP_Recv(player->fd, player->readbuffer + player->nread, 1);
 562
 563         if (r <= 0)
 564         {
 565           if (options.verbose)
 566             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 567                   player->number, player->player_name);
 568           RemovePlayer(player);
 569           interrupt = 1;
 570           break;
 571         }
 572         player->nread += r;
 573         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 574         {
 575           len = player->readbuffer[3];
 576           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 577           {
 578             if (options.verbose)
 579               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 580                     player->number, player->player_name);
 581             RemovePlayer(player);
 582             interrupt = 1;
 583             break;
 584           }
 585           memcpy(buffer, &player->readbuffer[4], len);
 586           player->nread -= 4 + len;
 587           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 588
 589           buffer[0] = player->number;
 590           if (!player->introduced && buffer[1] != OP_PLAYER_NAME)
 591           {
 592             if (options.verbose)
 593               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME)", buffer[0], buffer[1]);
 594
 595             RemovePlayer(player);
 596             interrupt = 1;
 597             break;
 598           }
 599
 600           switch (buffer[1])
 601           {
 602             case OP_PLAYER_NAME:
 603               Handle_OP_PLAYER_NAME(player, len);
 604               break;
 605
 606             case OP_PROTOCOL_VERSION:
 607               Handle_OP_PROTOCOL_VERSION(player, len);
 608               break;
 609
 610             case OP_NUMBER_WANTED:
 611               Handle_OP_NUMBER_WANTED(player);
 612               break;
 613
 614             case OP_START_PLAYING:
 615               Handle_OP_START_PLAYING(player);
 616               break;
 617
 618             case OP_PAUSE_PLAYING:
 619               Handle_OP_PAUSE_PLAYING(player);
 620               break;
 621
 622             case OP_CONTINUE_PLAYING:
 623               Handle_OP_CONTINUE_PLAYING(player);
 624               break;
 625
 626             case OP_STOP_PLAYING:
 627               Handle_OP_STOP_PLAYING(player);
 628               break;
 629
 630             case OP_MOVE_PLAYER:
 631               Handle_OP_MOVE_PLAYER(player);
 632               break;
 633
 634             case OP_BROADCAST_MESSAGE:
 635               buffer[len] = '\0';
 636               if (options.verbose)
 637                 Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
 638                       player->number, player->player_name, &buffer[2]);
 639               broadcast(player, len, 0);
 640               break;
 641
 642             default:
 643               if (options.verbose)
 644                 Error(ERR_NETWORK_SERVER,
 645                       "unknown opcode %d from client %d (%s)",
 646                       buffer[0], player->number, player->player_name);
 647           }
 648         }
 649       }
 650
 651       if (player && !interrupt)
 652         player = player->next;
 653     }
 654   }
 655 }