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 "libgame/platform.h"
  13
  14 #if defined(NETWORK_AVALIABLE)
  15
  16 #include <fcntl.h>
  17 #include <sys/time.h>
  18 #include <signal.h>
  19 #include <errno.h>
  20
  21 #include "main.h"
  22
  23 #include "libgame/libgame.h"
  24
  25 #include "netserv.h"
  26
  27 static int clients = 0;
  28 static int onceonly = 0;
  29
  30 struct NetworkServerPlayerInfo
  31 {
  32   TCPsocket fd;
  33   char player_name[16];
  34   unsigned char number;
  35   struct NetworkServerPlayerInfo *next;
  36   char active;
  37   char introduced;
  38   unsigned char readbuffer[MAX_BUFFER_SIZE];
  39   unsigned char writbuffer[MAX_BUFFER_SIZE];
  40   int nread, nwrite;
  41   byte action;
  42   boolean action_received;
  43 };
  44
  45 static struct NetworkServerPlayerInfo *first_player = NULL;
  46
  47 #define NEXT(player) ((player)->next ? (player)->next : first_player)
  48
  49 /* TODO: peer address */
  50 static TCPsocket lfd;           /* listening TCP socket */
  51 static UDPsocket udp;           /* listening UDP socket */
  52 static SDLNet_SocketSet fds;    /* socket set */
  53
  54 static unsigned char realbuffer[512], *buffer = realbuffer + 4;
  55
  56 static int interrupt;
  57
  58 static unsigned int ServerFrameCounter = 0;
  59
  60 static void addtobuffer(struct NetworkServerPlayerInfo *player,
  61                         unsigned char *b, int len)
  62 {
  63   if (player->nwrite + len >= MAX_BUFFER_SIZE)
  64     Error(ERR_EXIT_NETWORK_SERVER,
  65           "internal error: network send buffer overflow");
  66
  67   memcpy(player->writbuffer + player->nwrite, b, len);
  68   player->nwrite += len;
  69 }
  70
  71 static void flushuser(struct NetworkServerPlayerInfo *player)
  72 {
  73   if (player->nwrite)
  74   {
  75     SDLNet_TCP_Send(player->fd, player->writbuffer, player->nwrite);
  76
  77     player->nwrite = 0;
  78   }
  79 }
  80
  81 static void broadcast(struct NetworkServerPlayerInfo *except,
  82                       int len, int activeonly)
  83 {
  84   struct NetworkServerPlayerInfo *player;
  85
  86   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  87   realbuffer[3] = (unsigned char)len;
  88   for (player = first_player; player; player = player->next)
  89     if (player != except && player->introduced &&
  90         (player->active || !activeonly))
  91       addtobuffer(player, realbuffer, 4 + len);
  92 }
  93
  94 static void sendtoone(struct NetworkServerPlayerInfo *to, int len)
  95 {
  96   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  97   realbuffer[3] = (unsigned char)len;
  98   addtobuffer(to, realbuffer, 4 + len);
  99 }
 100
 101 static void RemovePlayer(struct NetworkServerPlayerInfo *player)
 102 {
 103   struct NetworkServerPlayerInfo *v;
 104
 105   if (options.verbose)
 106     Error(ERR_NETWORK_SERVER, "dropping client %d (%s)",
 107           player->number, player->player_name);
 108
 109   if (player == first_player)
 110     first_player = player->next;
 111   else
 112   {
 113     for (v = first_player; v; v = v->next)
 114     {
 115       if (v->next && v->next == player)
 116       {
 117         v->next = player->next;
 118         break;
 119       }
 120     }
 121   }
 122
 123   SDLNet_TCP_DelSocket(fds, player->fd);
 124   SDLNet_TCP_Close(player->fd);
 125
 126   if (player->introduced)
 127   {
 128     buffer[0] = player->number;
 129     buffer[1] = OP_PLAYER_DISCONNECTED;
 130     broadcast(player, 2, 0);
 131   }
 132
 133   free(player);
 134   clients--;
 135
 136   if (onceonly && clients == 0)
 137   {
 138     if (options.verbose)
 139     {
 140       Error(ERR_NETWORK_SERVER, "no clients left");
 141       Error(ERR_NETWORK_SERVER, "aborting");
 142     }
 143     exit(0);
 144   }
 145 }
 146
 147 static void AddPlayer(TCPsocket fd)
 148 {
 149   struct NetworkServerPlayerInfo *player, *v;
 150   unsigned char nxn;
 151   boolean again = TRUE;
 152
 153   player = checked_malloc(sizeof (struct NetworkServerPlayerInfo));
 154
 155   player->fd = fd;
 156   player->player_name[0] = 0;
 157   player->next = first_player;
 158   player->active = 0;
 159   player->nread = 0;
 160   player->nwrite = 0;
 161   player->introduced = 0;
 162   player->action = 0;
 163   player->action_received = FALSE;
 164
 165   SDLNet_TCP_AddSocket(fds, fd);
 166
 167   first_player = player;
 168
 169   nxn = 1;
 170
 171   while (again)
 172   {
 173     again = FALSE;
 174     v = player->next;
 175
 176     while (v)
 177     {
 178       if (v->number == nxn)
 179       {
 180         nxn++;
 181
 182         again = TRUE;
 183         break;
 184       }
 185       v = v->next;
 186     }
 187   }
 188
 189   player->number = nxn;
 190   clients++;
 191
 192   buffer[0] = 0;
 193   buffer[1] = OP_YOUR_NUMBER;
 194   buffer[2] = player->number;
 195   sendtoone(player, 3);
 196 }
 197
 198 static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player,
 199                                        unsigned int len)
 200 {
 201   if (len != 5 ||
 202       buffer[2] != PROTOCOL_VERSION_1 ||
 203       buffer[3] != PROTOCOL_VERSION_2)
 204   {
 205     if (options.verbose)
 206       Error(ERR_NETWORK_SERVER,
 207             "client %d (%s) has wrong protocol version %d.%d.%d",
 208             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 209
 210     buffer[0] = 0;
 211     buffer[1] = OP_BAD_PROTOCOL_VERSION;
 212     buffer[2] = PROTOCOL_VERSION_1;
 213     buffer[3] = PROTOCOL_VERSION_2;
 214     buffer[4] = PROTOCOL_VERSION_3;
 215     sendtoone(player, 5);
 216     flushuser(player);
 217
 218     RemovePlayer(player);
 219     interrupt = 1;
 220   }
 221   else
 222   {
 223     if (options.verbose)
 224       Error(ERR_NETWORK_SERVER,
 225             "client %d (%s) uses protocol version %d.%d.%d",
 226             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 227   }
 228 }
 229
 230 static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 231 {
 232   struct NetworkServerPlayerInfo *v;
 233   int client_nr = player->number;
 234   int nr_wanted = buffer[2];
 235   int nr_is_free = 1;
 236
 237   if (options.verbose)
 238       Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
 239             player->number, player->player_name, nr_wanted);
 240
 241   for (v = first_player; v; v = v->next)
 242   {
 243     if (v->number == nr_wanted)
 244     {
 245       nr_is_free = 0;
 246       break;
 247     }
 248   }
 249
 250   if (options.verbose)
 251   {
 252     if (nr_is_free)
 253       Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
 254             player->number, player->player_name, nr_wanted);
 255     else if (player->number == nr_wanted)
 256       Error(ERR_NETWORK_SERVER, "client %d (%s) already has # %d",
 257             player->number, player->player_name, nr_wanted);
 258     else
 259       Error(ERR_NETWORK_SERVER,
 260             "client %d (%s) cannot switch (client %d already exists)",
 261             player->number, player->player_name, nr_wanted);
 262   }
 263
 264   if (nr_is_free)
 265     player->number = nr_wanted;
 266
 267   buffer[0] = client_nr;
 268   buffer[1] = OP_NUMBER_WANTED;
 269   buffer[2] = nr_wanted;
 270   buffer[3] = player->number;
 271
 272   /*
 273   sendtoone(player, 4);
 274   */
 275
 276   broadcast(NULL, 4, 0);
 277 }
 278
 279 static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player,
 280                                   unsigned int len)
 281 {
 282   struct NetworkServerPlayerInfo *v;
 283   int i;
 284
 285   if (len>16)
 286     len=16;
 287   memcpy(player->player_name, &buffer[2], len-2);
 288   player->player_name[len-2] = 0;
 289   for (i = 0; i < len - 2; i++)
 290   {
 291     if (player->player_name[i] < ' ' ||
 292         ((unsigned char)(player->player_name[i]) > 0x7e &&
 293          (unsigned char)(player->player_name[i]) <= 0xa0))
 294     {
 295       player->player_name[i] = 0;
 296       break;
 297     }
 298   }
 299
 300   if (!player->introduced)
 301   {
 302     buffer[0] = player->number;
 303     buffer[1] = OP_PLAYER_CONNECTED;
 304     broadcast(player, 2, 0);
 305   }
 306
 307   if (options.verbose)
 308     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 309           player->number, player->player_name);
 310   buffer[1] = OP_PLAYER_NAME;
 311   broadcast(player, len, 0);
 312
 313   if (!player->introduced)
 314   {
 315     for (v = first_player; v; v = v->next)
 316     {
 317       if (v != player && v->introduced)
 318       {
 319         buffer[0] = v->number;
 320         buffer[1] = OP_PLAYER_CONNECTED;
 321         sendtoone(player, 2);
 322         buffer[1] = OP_PLAYER_NAME;
 323         memcpy(&buffer[2], v->player_name, 14);
 324         sendtoone(player, 2+strlen(v->player_name));
 325       }
 326     }
 327   }
 328
 329   player->introduced = 1;
 330 }
 331
 332 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 333 {
 334   struct NetworkServerPlayerInfo *v, *w;
 335
 336   if (options.verbose)
 337     Error(ERR_NETWORK_SERVER,
 338           "client %d (%s) starts game [level %d from leveldir %d (%s)]",
 339           player->number, player->player_name,
 340           (buffer[2] << 8) + buffer[3],
 341           (buffer[4] << 8) + buffer[5],
 342           &buffer[10]);
 343
 344   for (w = first_player; w; w = w->next)
 345     if (w->introduced)
 346       w->active = 1;
 347
 348   /* reset frame counter */
 349   ServerFrameCounter = 0;
 350
 351   Error(ERR_NETWORK_SERVER, "resetting ServerFrameCounter to 0");
 352
 353   /* reset player actions */
 354   for (v = first_player; v; v = v->next)
 355   {
 356     v->action = 0;
 357     v->action_received = FALSE;
 358   }
 359
 360   broadcast(NULL, 10 + strlen((char *)&buffer[10])+1, 0);
 361 }
 362
 363 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 364 {
 365   if (options.verbose)
 366     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 367           player->number, player->player_name);
 368   broadcast(NULL, 2, 0);
 369 }
 370
 371 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 372 {
 373   if (options.verbose)
 374     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 375           player->number, player->player_name);
 376   broadcast(NULL, 2, 0);
 377 }
 378
 379 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 380 {
 381   int cause_for_stopping = buffer[2];
 382
 383   if (options.verbose)
 384     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game [%d]",
 385           player->number, player->player_name, cause_for_stopping);
 386   broadcast(NULL, 3, 0);
 387 }
 388
 389 static void Handle_OP_MOVE_PLAYER(struct NetworkServerPlayerInfo *player)
 390 {
 391   struct NetworkServerPlayerInfo *v;
 392   int last_client_nr = 0;
 393   int i;
 394
 395   /* store player action */
 396   for (v = first_player; v; v = v->next)
 397   {
 398     if (v->number == player->number)
 399     {
 400       v->action = buffer[2];
 401       v->action_received = TRUE;
 402     }
 403   }
 404
 405   /* check if server received action from each player */
 406   for (v = first_player; v; v = v->next)
 407   {
 408     if (!v->action_received)
 409       return;
 410
 411     if (v->number > last_client_nr)
 412       last_client_nr = v->number;
 413   }
 414
 415   /* initialize all player actions to zero */
 416   for (i = 0; i < last_client_nr; i++)
 417     buffer[6 + i] = 0;
 418
 419   /* broadcast actions of all players to all players */
 420   for (v = first_player; v; v = v->next)
 421   {
 422     buffer[6 + v->number-1] = v->action;
 423     v->action = 0;
 424     v->action_received = FALSE;
 425   }
 426
 427   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 428   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 429   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 430   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 431
 432   broadcast(NULL, 6 + last_client_nr, 0);
 433
 434   ServerFrameCounter++;
 435 }
 436
 437 void ExitNetworkServer(int exit_value)
 438 {
 439   Error(ERR_NETWORK_SERVER, "exiting network server");
 440
 441   exit(exit_value);
 442 }
 443
 444 /* the following is not used for a standalone server;
 445    the pointer points to an integer containing the port-number */
 446 int NetworkServerThread(void *ptr)
 447 {
 448   NetworkServer(*((int *) ptr), 0);
 449
 450   /* should never be reached */
 451   return 0;
 452 }
 453
 454 void NetworkServer(int port, int serveronly)
 455 {
 456   struct NetworkServerPlayerInfo *player;
 457   int r;
 458   unsigned int len;
 459   IPaddress ip;
 460
 461 #if defined(PLATFORM_UNIX) && !defined(PLATFORM_NEXT)
 462   struct sigaction sact;
 463 #endif
 464
 465   if (port == 0)
 466     port = DEFAULT_SERVER_PORT;
 467
 468   // if only running the network server, exit on Ctrl-C
 469   if (serveronly)
 470     signal(SIGINT, ExitNetworkServer);
 471
 472   if (!serveronly)
 473     onceonly = 1;
 474
 475 #if defined(PLATFORM_UNIX)
 476 #if defined(PLATFORM_NEXT)
 477   signal(SIGPIPE, SIG_IGN);
 478 #else
 479   sact.sa_handler = SIG_IGN;
 480   sigemptyset(&sact.sa_mask);
 481   sact.sa_flags = 0;
 482   sigaction(SIGPIPE, &sact, NULL);
 483 #endif
 484 #endif
 485
 486   if (SDLNet_ResolveHost(&ip, NULL, port) == -1)
 487     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_ResolveHost() failed: %s",
 488           SDLNet_GetError());
 489
 490   if ((fds = SDLNet_AllocSocketSet(MAX_PLAYERS + 1 + 1)) == NULL)
 491     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_AllocSocketSet() failed: %s"),
 492       SDLNet_GetError();
 493
 494   if ((lfd = SDLNet_TCP_Open(&ip)) == NULL)
 495     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_Open() failed: %s"),
 496       SDLNet_GetError();
 497
 498   if (SDLNet_TCP_AddSocket(fds, lfd) == -1)
 499     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 500       SDLNet_GetError();
 501
 502   if ((udp = SDLNet_UDP_Open(port)) == NULL)
 503     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_UDP_Open() failed: %s",
 504           SDLNet_GetError());
 505
 506   if (SDLNet_UDP_AddSocket(fds, udp) == -1)
 507     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 508       SDLNet_GetError();
 509
 510   if (options.verbose)
 511   {
 512     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 513     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 514           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 515   }
 516
 517   while (1)
 518   {
 519     interrupt = 0;
 520
 521     for (player = first_player; player; player = player->next)
 522       flushuser(player);
 523
 524     // wait for 100 ms for activity on open network sockets
 525     if (SDLNet_CheckSockets(fds, 100) < 1)
 526       continue;
 527
 528     /* accept incoming TCP connections */
 529     if (SDLNet_SocketReady(lfd))
 530     {
 531       Error(ERR_DEBUG, "got TCP packet");
 532
 533       TCPsocket newsock;
 534
 535       newsock = SDLNet_TCP_Accept(lfd);
 536
 537       if (newsock)
 538         AddPlayer(newsock);
 539     }
 540
 541     /* accept incoming UDP packets */
 542     if (SDLNet_SocketReady(udp))
 543     {
 544       Error(ERR_DEBUG, "got UDP packet");
 545
 546       static UDPpacket packet;
 547
 548       int num_packets = SDLNet_UDP_Recv(udp, &packet);
 549
 550       if (num_packets == 1)
 551       {
 552         // bounce packet
 553         SDLNet_UDP_Send(udp, -1, &packet);
 554       }
 555     }
 556
 557     player = first_player;
 558
 559     while (player && !interrupt)
 560     {
 561       if (SDLNet_SocketReady(player->fd))
 562       {
 563         /* read only 1 byte, because SDLNet blocks when we want more than is
 564            in the buffer */
 565         r = SDLNet_TCP_Recv(player->fd, player->readbuffer + player->nread, 1);
 566
 567         if (r <= 0)
 568         {
 569           if (options.verbose)
 570             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 571                   player->number, player->player_name);
 572           RemovePlayer(player);
 573           interrupt = 1;
 574           break;
 575         }
 576         player->nread += r;
 577         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 578         {
 579           len = player->readbuffer[3];
 580           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 581           {
 582             if (options.verbose)
 583               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 584                     player->number, player->player_name);
 585             RemovePlayer(player);
 586             interrupt = 1;
 587             break;
 588           }
 589           memcpy(buffer, &player->readbuffer[4], len);
 590           player->nread -= 4 + len;
 591           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 592
 593           buffer[0] = player->number;
 594           if (!player->introduced && buffer[1] != OP_PLAYER_NAME)
 595           {
 596             if (options.verbose)
 597               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME)", buffer[0], buffer[1]);
 598
 599             RemovePlayer(player);
 600             interrupt = 1;
 601             break;
 602           }
 603
 604           switch (buffer[1])
 605           {
 606             case OP_PLAYER_NAME:
 607               Handle_OP_PLAYER_NAME(player, len);
 608               break;
 609
 610             case OP_PROTOCOL_VERSION:
 611               Handle_OP_PROTOCOL_VERSION(player, len);
 612               break;
 613
 614             case OP_NUMBER_WANTED:
 615               Handle_OP_NUMBER_WANTED(player);
 616               break;
 617
 618             case OP_START_PLAYING:
 619               Handle_OP_START_PLAYING(player);
 620               break;
 621
 622             case OP_PAUSE_PLAYING:
 623               Handle_OP_PAUSE_PLAYING(player);
 624               break;
 625
 626             case OP_CONTINUE_PLAYING:
 627               Handle_OP_CONTINUE_PLAYING(player);
 628               break;
 629
 630             case OP_STOP_PLAYING:
 631               Handle_OP_STOP_PLAYING(player);
 632               break;
 633
 634             case OP_MOVE_PLAYER:
 635               Handle_OP_MOVE_PLAYER(player);
 636               break;
 637
 638             case OP_BROADCAST_MESSAGE:
 639               buffer[len] = '\0';
 640               if (options.verbose)
 641                 Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
 642                       player->number, player->player_name, &buffer[2]);
 643               broadcast(player, len, 0);
 644               break;
 645
 646             default:
 647               if (options.verbose)
 648                 Error(ERR_NETWORK_SERVER,
 649                       "unknown opcode %d from client %d (%s)",
 650                       buffer[0], player->number, player->player_name);
 651           }
 652         }
 653       }
 654
 655       if (player && !interrupt)
 656         player = player->next;
 657     }
 658   }
 659 }
 660
 661 #endif /* NETWORK_AVALIABLE */