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 0   /* do not terminate network server if last player disconnected */
 133   if (onceonly && clients == 0)
 134   {
 135     if (options.verbose)
 136     {
 137       Error(ERR_NETWORK_SERVER, "no clients left");
 138       Error(ERR_NETWORK_SERVER, "aborting");
 139     }
 140     exit(0);
 141   }
 142 #endif
 143 }
 144
 145 static void AddPlayer(TCPsocket fd)
 146 {
 147   struct NetworkServerPlayerInfo *player, *v;
 148   unsigned char nxn;
 149   boolean again = TRUE;
 150
 151   player = checked_malloc(sizeof (struct NetworkServerPlayerInfo));
 152
 153   player->fd = fd;
 154   player->player_name[0] = 0;
 155   player->next = first_player;
 156   player->active = 0;
 157   player->nread = 0;
 158   player->nwrite = 0;
 159   player->introduced = 0;
 160   player->action = 0;
 161   player->action_received = FALSE;
 162
 163   SDLNet_TCP_AddSocket(fds, fd);
 164
 165   first_player = player;
 166
 167   nxn = 1;
 168
 169   while (again)
 170   {
 171     again = FALSE;
 172     v = player->next;
 173
 174     while (v)
 175     {
 176       if (v->number == nxn)
 177       {
 178         nxn++;
 179
 180         again = TRUE;
 181         break;
 182       }
 183       v = v->next;
 184     }
 185   }
 186
 187   player->number = nxn;
 188   clients++;
 189
 190   buffer[0] = 0;
 191   buffer[1] = OP_YOUR_NUMBER;
 192   buffer[2] = player->number;
 193   sendtoone(player, 3);
 194 }
 195
 196 static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player,
 197                                        unsigned int len)
 198 {
 199   if (len != 5 ||
 200       buffer[2] != PROTOCOL_VERSION_1 ||
 201       buffer[3] != PROTOCOL_VERSION_2)
 202   {
 203     if (options.verbose)
 204       Error(ERR_NETWORK_SERVER,
 205             "client %d (%s) has wrong protocol version %d.%d.%d",
 206             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 207
 208     buffer[0] = 0;
 209     buffer[1] = OP_BAD_PROTOCOL_VERSION;
 210     buffer[2] = PROTOCOL_VERSION_1;
 211     buffer[3] = PROTOCOL_VERSION_2;
 212     buffer[4] = PROTOCOL_VERSION_3;
 213     sendtoone(player, 5);
 214     flushuser(player);
 215
 216     RemovePlayer(player);
 217     interrupt = 1;
 218   }
 219   else
 220   {
 221     if (options.verbose)
 222       Error(ERR_NETWORK_SERVER,
 223             "client %d (%s) uses protocol version %d.%d.%d",
 224             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 225   }
 226 }
 227
 228 static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 229 {
 230   struct NetworkServerPlayerInfo *v;
 231   int client_nr = player->number;
 232   int nr_wanted = buffer[2];
 233   int nr_is_free = 1;
 234
 235   if (options.verbose)
 236       Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
 237             player->number, player->player_name, nr_wanted);
 238
 239   for (v = first_player; v; v = v->next)
 240   {
 241     if (v->number == nr_wanted)
 242     {
 243       nr_is_free = 0;
 244       break;
 245     }
 246   }
 247
 248   if (options.verbose)
 249   {
 250     if (nr_is_free)
 251       Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
 252             player->number, player->player_name, nr_wanted);
 253     else if (player->number == nr_wanted)
 254       Error(ERR_NETWORK_SERVER, "client %d (%s) already has # %d",
 255             player->number, player->player_name, nr_wanted);
 256     else
 257       Error(ERR_NETWORK_SERVER,
 258             "client %d (%s) cannot switch (client %d already exists)",
 259             player->number, player->player_name, nr_wanted);
 260   }
 261
 262   if (nr_is_free)
 263     player->number = nr_wanted;
 264
 265   buffer[0] = client_nr;
 266   buffer[1] = OP_NUMBER_WANTED;
 267   buffer[2] = nr_wanted;
 268   buffer[3] = player->number;
 269
 270   /*
 271   sendtoone(player, 4);
 272   */
 273
 274   broadcast(NULL, 4, 0);
 275 }
 276
 277 static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player,
 278                                   unsigned int len)
 279 {
 280   struct NetworkServerPlayerInfo *v;
 281   int i;
 282
 283   if (len>16)
 284     len=16;
 285   memcpy(player->player_name, &buffer[2], len-2);
 286   player->player_name[len-2] = 0;
 287   for (i = 0; i < len - 2; i++)
 288   {
 289     if (player->player_name[i] < ' ' ||
 290         ((unsigned char)(player->player_name[i]) > 0x7e &&
 291          (unsigned char)(player->player_name[i]) <= 0xa0))
 292     {
 293       player->player_name[i] = 0;
 294       break;
 295     }
 296   }
 297
 298   if (!player->introduced)
 299   {
 300     buffer[0] = player->number;
 301     buffer[1] = OP_PLAYER_CONNECTED;
 302     broadcast(player, 2, 0);
 303   }
 304
 305   if (options.verbose)
 306     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 307           player->number, player->player_name);
 308   buffer[1] = OP_PLAYER_NAME;
 309   broadcast(player, len, 0);
 310
 311   if (!player->introduced)
 312   {
 313     for (v = first_player; v; v = v->next)
 314     {
 315       if (v != player && v->introduced)
 316       {
 317         buffer[0] = v->number;
 318         buffer[1] = OP_PLAYER_CONNECTED;
 319         sendtoone(player, 2);
 320         buffer[1] = OP_PLAYER_NAME;
 321         memcpy(&buffer[2], v->player_name, 14);
 322         sendtoone(player, 2+strlen(v->player_name));
 323       }
 324     }
 325   }
 326
 327   player->introduced = 1;
 328 }
 329
 330 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 331 {
 332   struct NetworkServerPlayerInfo *v, *w;
 333
 334   if (options.verbose)
 335     Error(ERR_NETWORK_SERVER,
 336           "client %d (%s) starts game [level %d from leveldir %d (%s)]",
 337           player->number, player->player_name,
 338           (buffer[2] << 8) + buffer[3],
 339           (buffer[4] << 8) + buffer[5],
 340           &buffer[10]);
 341
 342   for (w = first_player; w; w = w->next)
 343     if (w->introduced)
 344       w->active = 1;
 345
 346   /* reset frame counter */
 347   ServerFrameCounter = 0;
 348
 349   Error(ERR_NETWORK_SERVER, "resetting ServerFrameCounter to 0");
 350
 351   /* reset player actions */
 352   for (v = first_player; v; v = v->next)
 353   {
 354     v->action = 0;
 355     v->action_received = FALSE;
 356   }
 357
 358   broadcast(NULL, 10 + strlen((char *)&buffer[10])+1, 0);
 359 }
 360
 361 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 362 {
 363   if (options.verbose)
 364     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 365           player->number, player->player_name);
 366   broadcast(NULL, 2, 0);
 367 }
 368
 369 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 370 {
 371   if (options.verbose)
 372     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 373           player->number, player->player_name);
 374   broadcast(NULL, 2, 0);
 375 }
 376
 377 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 378 {
 379   int cause_for_stopping = buffer[2];
 380
 381   if (options.verbose)
 382     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game [%d]",
 383           player->number, player->player_name, cause_for_stopping);
 384   broadcast(NULL, 3, 0);
 385 }
 386
 387 static void Handle_OP_MOVE_PLAYER(struct NetworkServerPlayerInfo *player)
 388 {
 389   struct NetworkServerPlayerInfo *v;
 390   int last_client_nr = 0;
 391   int i;
 392
 393   /* store player action */
 394   for (v = first_player; v; v = v->next)
 395   {
 396     if (v->number == player->number)
 397     {
 398       v->action = buffer[2];
 399       v->action_received = TRUE;
 400     }
 401   }
 402
 403   /* check if server received action from each player */
 404   for (v = first_player; v; v = v->next)
 405   {
 406     if (!v->action_received)
 407       return;
 408
 409     if (v->number > last_client_nr)
 410       last_client_nr = v->number;
 411   }
 412
 413   /* initialize all player actions to zero */
 414   for (i = 0; i < last_client_nr; i++)
 415     buffer[6 + i] = 0;
 416
 417   /* broadcast actions of all players to all players */
 418   for (v = first_player; v; v = v->next)
 419   {
 420     buffer[6 + v->number-1] = v->action;
 421     v->action = 0;
 422     v->action_received = FALSE;
 423   }
 424
 425   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 426   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 427   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 428   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 429
 430   broadcast(NULL, 6 + last_client_nr, 0);
 431
 432   ServerFrameCounter++;
 433 }
 434
 435 void ExitNetworkServer(int exit_value)
 436 {
 437   Error(ERR_NETWORK_SERVER, "exiting network server");
 438
 439   exit(exit_value);
 440 }
 441
 442 /* the following is not used for a standalone server;
 443    the pointer points to an integer containing the port-number */
 444 int NetworkServerThread(void *ptr)
 445 {
 446   NetworkServer(*((int *) ptr), 0);
 447
 448   /* should never be reached */
 449   return 0;
 450 }
 451
 452 void NetworkServer(int port, int serveronly)
 453 {
 454   struct NetworkServerPlayerInfo *player;
 455   int r;
 456   unsigned int len;
 457   IPaddress ip;
 458
 459 #if defined(PLATFORM_UNIX) && !defined(PLATFORM_NEXT)
 460   struct sigaction sact;
 461 #endif
 462
 463   if (port == 0)
 464     port = DEFAULT_SERVER_PORT;
 465
 466   // if only running the network server, exit on Ctrl-C
 467   if (serveronly)
 468     signal(SIGINT, ExitNetworkServer);
 469
 470   if (!serveronly)
 471     onceonly = 1;
 472
 473 #if defined(PLATFORM_UNIX)
 474 #if defined(PLATFORM_NEXT)
 475   signal(SIGPIPE, SIG_IGN);
 476 #else
 477   sact.sa_handler = SIG_IGN;
 478   sigemptyset(&sact.sa_mask);
 479   sact.sa_flags = 0;
 480   sigaction(SIGPIPE, &sact, NULL);
 481 #endif
 482 #endif
 483
 484   if (SDLNet_ResolveHost(&ip, NULL, port) == -1)
 485     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_ResolveHost() failed: %s",
 486           SDLNet_GetError());
 487
 488   if ((fds = SDLNet_AllocSocketSet(MAX_PLAYERS + 1 + 1)) == NULL)
 489     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_AllocSocketSet() failed: %s"),
 490       SDLNet_GetError();
 491
 492   if ((lfd = SDLNet_TCP_Open(&ip)) == NULL)
 493     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_Open() failed: %s"),
 494       SDLNet_GetError();
 495
 496   if (SDLNet_TCP_AddSocket(fds, lfd) == -1)
 497     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 498       SDLNet_GetError();
 499
 500   if ((udp = SDLNet_UDP_Open(port)) == NULL)
 501     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_UDP_Open() failed: %s",
 502           SDLNet_GetError());
 503
 504   if (SDLNet_UDP_AddSocket(fds, udp) == -1)
 505     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_AddSocket() failed: %s"),
 506       SDLNet_GetError();
 507
 508   if (options.verbose)
 509   {
 510     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 511     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 512           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 513   }
 514
 515   while (1)
 516   {
 517     interrupt = 0;
 518
 519     for (player = first_player; player; player = player->next)
 520       flushuser(player);
 521
 522     // wait for 100 ms for activity on open network sockets
 523     if (SDLNet_CheckSockets(fds, 100) < 1)
 524       continue;
 525
 526     /* accept incoming TCP connections */
 527     if (SDLNet_SocketReady(lfd))
 528     {
 529       Error(ERR_DEBUG, "got TCP packet");
 530
 531       TCPsocket newsock;
 532
 533       newsock = SDLNet_TCP_Accept(lfd);
 534
 535       if (newsock)
 536         AddPlayer(newsock);
 537     }
 538
 539     /* accept incoming UDP packets */
 540     if (SDLNet_SocketReady(udp))
 541     {
 542       Error(ERR_DEBUG, "got UDP packet");
 543
 544       static UDPpacket packet;
 545
 546       int num_packets = SDLNet_UDP_Recv(udp, &packet);
 547
 548       if (num_packets == 1)
 549       {
 550         // bounce packet
 551         SDLNet_UDP_Send(udp, -1, &packet);
 552       }
 553     }
 554
 555     player = first_player;
 556
 557     while (player && !interrupt)
 558     {
 559       if (SDLNet_SocketReady(player->fd))
 560       {
 561         /* read only 1 byte, because SDLNet blocks when we want more than is
 562            in the buffer */
 563         r = SDLNet_TCP_Recv(player->fd, player->readbuffer + player->nread, 1);
 564
 565         if (r <= 0)
 566         {
 567           if (options.verbose)
 568             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 569                   player->number, player->player_name);
 570           RemovePlayer(player);
 571           interrupt = 1;
 572           break;
 573         }
 574         player->nread += r;
 575         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 576         {
 577           len = player->readbuffer[3];
 578           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 579           {
 580             if (options.verbose)
 581               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 582                     player->number, player->player_name);
 583             RemovePlayer(player);
 584             interrupt = 1;
 585             break;
 586           }
 587           memcpy(buffer, &player->readbuffer[4], len);
 588           player->nread -= 4 + len;
 589           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 590
 591           buffer[0] = player->number;
 592           if (!player->introduced &&
 593               buffer[1] != OP_PLAYER_NAME &&
 594               buffer[1] != OP_PROTOCOL_VERSION)
 595           {
 596             if (options.verbose)
 597               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME or OP_PROTOCOL_VERSION)", 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 }