src/netserv.c

   1 /***********************************************************
   2 * Rocks'n'Diamonds -- McDuffin Strikes Back!               *
   3 *----------------------------------------------------------*
   4 * (c) 1995-2002 Artsoft Entertainment                      *
   5 *               Holger Schemel                             *
   6 *               Detmolder Strasse 189                      *
   7 *               33604 Bielefeld                            *
   8 *               Germany                                    *
   9 *               e-mail: info@artsoft.org                   *
  10 *----------------------------------------------------------*
  11 * network.c                                                *
  12 ***********************************************************/
  13
  14 #include "libgame/platform.h"
  15
  16 #if defined(PLATFORM_UNIX)
  17
  18 #include <fcntl.h>
  19 #include <sys/time.h>
  20 #include <signal.h>
  21 #include <sys/socket.h>
  22 #include <errno.h>
  23 #include <netinet/in.h>
  24 #include <netinet/tcp.h>
  25 #include <arpa/inet.h>
  26 #include <netdb.h>
  27
  28 #include "libgame/libgame.h"
  29
  30 #include "netserv.h"
  31
  32 static int clients = 0;
  33 static int onceonly = 0;
  34
  35 struct NetworkServerPlayerInfo
  36 {
  37   int fd;
  38   char player_name[16];
  39   unsigned char number;
  40   struct NetworkServerPlayerInfo *next;
  41   char active;
  42   char introduced;
  43   unsigned char readbuffer[MAX_BUFFER_SIZE];
  44   unsigned char writbuffer[MAX_BUFFER_SIZE];
  45   int nread, nwrite;
  46   byte action;
  47   boolean action_received;
  48 };
  49
  50 static struct NetworkServerPlayerInfo *first_player = NULL;
  51
  52 #define NEXT(player) ((player)->next ? (player)->next : first_player)
  53
  54 static struct sockaddr_in saddr;
  55 static int lfd;
  56 static unsigned char realbuffer[512], *buffer = realbuffer + 4;
  57
  58 static int interrupt;
  59 static int tcp = -1;
  60
  61 static unsigned long ServerFrameCounter = 0;
  62
  63 static fd_set fds;
  64
  65 static void addtobuffer(struct NetworkServerPlayerInfo *player,
  66                         unsigned char *b, int len)
  67 {
  68   if (player->nwrite + len >= MAX_BUFFER_SIZE)
  69     Error(ERR_EXIT_NETWORK_SERVER,
  70           "internal error: network send buffer overflow");
  71
  72   memcpy(player->writbuffer + player->nwrite, b, len);
  73   player->nwrite += len;
  74 }
  75
  76 static void flushuser(struct NetworkServerPlayerInfo *player)
  77 {
  78   if (player->nwrite)
  79   {
  80     write(player->fd, player->writbuffer, player->nwrite);
  81     player->nwrite = 0;
  82   }
  83 }
  84
  85 static void broadcast(struct NetworkServerPlayerInfo *except,
  86                       int len, int activeonly)
  87 {
  88   struct NetworkServerPlayerInfo *player;
  89
  90   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  91   realbuffer[3] = (unsigned char)len;
  92   for (player = first_player; player; player = player->next)
  93     if (player != except && player->introduced &&
  94         (player->active || !activeonly))
  95       addtobuffer(player, realbuffer, 4 + len);
  96 }
  97
  98 static void sendtoone(struct NetworkServerPlayerInfo *to, int len)
  99 {
 100   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
 101   realbuffer[3] = (unsigned char)len;
 102   addtobuffer(to, realbuffer, 4 + len);
 103 }
 104
 105 static void RemovePlayer(struct NetworkServerPlayerInfo *player)
 106 {
 107   struct NetworkServerPlayerInfo *v;
 108
 109   if (options.verbose)
 110     Error(ERR_NETWORK_SERVER, "dropping client %d (%s)",
 111           player->number, player->player_name);
 112
 113   if (player == first_player)
 114     first_player = player->next;
 115   else
 116   {
 117     for (v = first_player; v; v = v->next)
 118     {
 119       if (v->next && v->next == player)
 120       {
 121         v->next = player->next;
 122         break;
 123       }
 124     }
 125   }
 126   close(player->fd);
 127
 128   if (player->introduced)
 129   {
 130     buffer[0] = player->number;
 131     buffer[1] = OP_PLAYER_DISCONNECTED;
 132     broadcast(player, 2, 0);
 133   }
 134
 135   free(player);
 136   clients--;
 137
 138   if (onceonly && clients == 0)
 139   {
 140     if (options.verbose)
 141     {
 142       Error(ERR_NETWORK_SERVER, "no clients left");
 143       Error(ERR_NETWORK_SERVER, "aborting");
 144     }
 145     exit(0);
 146   }
 147 }
 148
 149 static void AddPlayer(int fd)
 150 {
 151   struct NetworkServerPlayerInfo *player, *v;
 152   unsigned char nxn;
 153   boolean again = TRUE;
 154
 155   player = checked_malloc(sizeof (struct NetworkServerPlayerInfo));
 156
 157   player->fd = fd;
 158   player->player_name[0] = 0;
 159   player->next = first_player;
 160   player->active = 0;
 161   player->nread = 0;
 162   player->nwrite = 0;
 163   player->introduced = 0;
 164   player->action = 0;
 165   player->action_received = FALSE;
 166
 167   first_player = player;
 168
 169   nxn = 1;
 170
 171 #if 1
 172   while (again)
 173   {
 174     again = FALSE;
 175     v = player->next;
 176
 177     while (v)
 178     {
 179       if (v->number == nxn)
 180       {
 181         nxn++;
 182
 183         again = TRUE;
 184         break;
 185       }
 186       v = v->next;
 187     }
 188   }
 189 #else
 190  again:
 191   v = player->next;
 192   while (v)
 193   {
 194     if (v->number == nxn)
 195     {
 196       nxn++;
 197       goto again;
 198     }
 199     v = v->next;
 200   }
 201 #endif
 202
 203   player->number = nxn;
 204   if (options.verbose)
 205     Error(ERR_NETWORK_SERVER, "client %d connecting from %s",
 206           nxn, inet_ntoa(saddr.sin_addr));
 207   clients++;
 208
 209   buffer[0] = 0;
 210   buffer[1] = OP_YOUR_NUMBER;
 211   buffer[2] = player->number;
 212   sendtoone(player, 3);
 213 }
 214
 215 static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player,
 216                                        unsigned int len)
 217 {
 218   if (len != 5 ||
 219       buffer[2] != PROTOCOL_VERSION_1 ||
 220       buffer[3] != PROTOCOL_VERSION_2)
 221   {
 222     if (options.verbose)
 223       Error(ERR_NETWORK_SERVER,
 224             "client %d (%s) has wrong protocol version %d.%d.%d",
 225             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 226
 227     buffer[0] = 0;
 228     buffer[1] = OP_BAD_PROTOCOL_VERSION;
 229     buffer[2] = PROTOCOL_VERSION_1;
 230     buffer[3] = PROTOCOL_VERSION_2;
 231     buffer[4] = PROTOCOL_VERSION_3;
 232     sendtoone(player, 5);
 233     flushuser(player);
 234
 235     RemovePlayer(player);
 236     interrupt = 1;
 237   }
 238   else
 239   {
 240     if (options.verbose)
 241       Error(ERR_NETWORK_SERVER,
 242             "client %d (%s) uses protocol version %d.%d.%d",
 243             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 244   }
 245 }
 246
 247 static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 248 {
 249   struct NetworkServerPlayerInfo *v;
 250   int client_nr = player->number;
 251   int nr_wanted = buffer[2];
 252   int nr_is_free = 1;
 253
 254   if (options.verbose)
 255       Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
 256             player->number, player->player_name, nr_wanted);
 257
 258   for (v = first_player; v; v = v->next)
 259   {
 260     if (v->number == nr_wanted)
 261     {
 262       nr_is_free = 0;
 263       break;
 264     }
 265   }
 266
 267   if (options.verbose)
 268   {
 269     if (nr_is_free)
 270       Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
 271             player->number, player->player_name, nr_wanted);
 272     else if (player->number == nr_wanted)
 273       Error(ERR_NETWORK_SERVER, "client %d (%s) still has # %d",
 274             player->number, player->player_name, nr_wanted);
 275     else
 276       Error(ERR_NETWORK_SERVER,
 277             "client %d (%s) cannot switch (client %d still exists)",
 278             player->number, player->player_name, nr_wanted);
 279   }
 280
 281   if (nr_is_free)
 282     player->number = nr_wanted;
 283
 284   buffer[0] = client_nr;
 285   buffer[1] = OP_NUMBER_WANTED;
 286   buffer[2] = nr_wanted;
 287   buffer[3] = player->number;
 288
 289   /*
 290   sendtoone(player, 4);
 291   */
 292
 293   broadcast(NULL, 4, 0);
 294 }
 295
 296 static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player,
 297                                   unsigned int len)
 298 {
 299   struct NetworkServerPlayerInfo *v;
 300   int i;
 301
 302   if (len>16)
 303     len=16;
 304   memcpy(player->player_name, &buffer[2], len-2);
 305   player->player_name[len-2] = 0;
 306   for (i = 0; i < len - 2; i++)
 307   {
 308     if (player->player_name[i] < ' ' ||
 309         ((unsigned char)(player->player_name[i]) > 0x7e &&
 310          (unsigned char)(player->player_name[i]) <= 0xa0))
 311     {
 312       player->player_name[i] = 0;
 313       break;
 314     }
 315   }
 316
 317   if (!player->introduced)
 318   {
 319     buffer[0] = player->number;
 320     buffer[1] = OP_PLAYER_CONNECTED;
 321     broadcast(player, 2, 0);
 322   }
 323
 324   if (options.verbose)
 325     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 326           player->number, player->player_name);
 327   buffer[1] = OP_PLAYER_NAME;
 328   broadcast(player, len, 0);
 329
 330   if (!player->introduced)
 331   {
 332     for (v = first_player; v; v = v->next)
 333     {
 334       if (v != player && v->introduced)
 335       {
 336         buffer[0] = v->number;
 337         buffer[1] = OP_PLAYER_CONNECTED;
 338         sendtoone(player, 2);
 339         buffer[1] = OP_PLAYER_NAME;
 340         memcpy(&buffer[2], v->player_name, 14);
 341         sendtoone(player, 2+strlen(v->player_name));
 342       }
 343     }
 344   }
 345
 346   player->introduced = 1;
 347 }
 348
 349 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 350 {
 351   struct NetworkServerPlayerInfo *v, *w;
 352
 353   if (options.verbose)
 354     Error(ERR_NETWORK_SERVER,
 355           "client %d (%s) starts game [level %d from levedir %d (%s)]",
 356           player->number, player->player_name,
 357           (buffer[2] << 8) + buffer[3],
 358           (buffer[4] << 8) + buffer[5],
 359           &buffer[6]);
 360
 361   for (w = first_player; w; w = w->next)
 362     if (w->introduced)
 363       w->active = 1;
 364
 365   /* reset frame counter */
 366   ServerFrameCounter = 0;
 367
 368   /* reset player actions */
 369   for (v = first_player; v; v = v->next)
 370   {
 371     v->action = 0;
 372     v->action_received = FALSE;
 373   }
 374
 375   broadcast(NULL, 10 + strlen((char *)&buffer[10])+1, 0);
 376 }
 377
 378 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 379 {
 380   if (options.verbose)
 381     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 382           player->number, player->player_name);
 383   broadcast(NULL, 2, 0);
 384 }
 385
 386 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 387 {
 388   if (options.verbose)
 389     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 390           player->number, player->player_name);
 391   broadcast(NULL, 2, 0);
 392 }
 393
 394 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 395 {
 396   if (options.verbose)
 397     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game",
 398           player->number, player->player_name);
 399   broadcast(NULL, 2, 0);
 400 }
 401
 402 static void Handle_OP_MOVE_PLAYER(struct NetworkServerPlayerInfo *player)
 403 {
 404   struct NetworkServerPlayerInfo *v;
 405   int last_client_nr = 0;
 406   int i;
 407
 408   /* store player action */
 409   for (v = first_player; v; v = v->next)
 410   {
 411     if (v->number == player->number)
 412     {
 413       v->action = buffer[2];
 414       v->action_received = TRUE;
 415     }
 416   }
 417
 418   /* check if server received action from each player */
 419   for (v = first_player; v; v = v->next)
 420   {
 421     if (!v->action_received)
 422       return;
 423
 424     if (v->number > last_client_nr)
 425       last_client_nr = v->number;
 426   }
 427
 428   /* initialize all player actions to zero */
 429   for (i = 0; i < last_client_nr; i++)
 430     buffer[6 + i] = 0;
 431
 432   /* broadcast actions of all players to all players */
 433   for (v = first_player; v; v = v->next)
 434   {
 435     buffer[6 + v->number-1] = v->action;
 436     v->action = 0;
 437     v->action_received = FALSE;
 438   }
 439
 440   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 441   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 442   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 443   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 444
 445   broadcast(NULL, 6 + last_client_nr, 0);
 446
 447   ServerFrameCounter++;
 448 }
 449
 450 void NetworkServer(int port, int serveronly)
 451 {
 452   int i, sl, on;
 453   struct NetworkServerPlayerInfo *player;
 454   int mfd;
 455   int r;
 456   unsigned int len;
 457   struct protoent *tcpproto;
 458   struct timeval tv;
 459   int is_daemon = 0;
 460
 461 #ifndef NeXT
 462   struct sigaction sact;
 463 #endif
 464
 465   if (port == 0)
 466     port = DEFAULT_SERVER_PORT;
 467
 468   if (!serveronly)
 469     onceonly = 1;
 470
 471   if ((tcpproto = getprotobyname("tcp")) != NULL)
 472     tcp = tcpproto->p_proto;
 473
 474 #ifdef 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
 483
 484   if ((lfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
 485     Error(ERR_EXIT_NETWORK_SERVER, "socket() failed");
 486
 487   saddr.sin_family = AF_INET;
 488   saddr.sin_addr.s_addr = htonl(INADDR_ANY);
 489   saddr.sin_port = htons(port);
 490
 491   on = 1;
 492
 493   setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(int));
 494   if (bind(lfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0)
 495     Error(ERR_EXIT_NETWORK_SERVER, "bind() failed");
 496
 497   listen(lfd, 5);
 498
 499   if (is_daemon)
 500   {
 501     /* become a daemon, breaking all ties with the controlling terminal */
 502     options.verbose = FALSE;
 503     for (i = 0; i < 255; i++)
 504     {
 505       if (i != lfd)
 506         close(i);
 507     }
 508
 509     if (fork())
 510       exit(0);
 511     setsid();
 512     if (fork())
 513       exit(0);
 514     chdir("/");
 515
 516     /* open a fake stdin, stdout, stderr, just in case */
 517     open("/dev/null", O_RDONLY);
 518     open("/dev/null", O_WRONLY);
 519     open("/dev/null", O_WRONLY);
 520   }
 521
 522   if (options.verbose)
 523   {
 524     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 525     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 526           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 527   }
 528
 529   while (1)
 530   {
 531     interrupt = 0;
 532
 533     for (player = first_player; player; player = player->next)
 534       flushuser(player);
 535
 536     FD_ZERO(&fds);
 537     mfd = lfd;
 538     player = first_player;
 539     while (player)
 540     {
 541       FD_SET(player->fd, &fds);
 542       if (player->fd > mfd)
 543         mfd = player->fd;
 544       player = player->next;
 545     }
 546     FD_SET(lfd, &fds);
 547     tv.tv_sec = 0;
 548     tv.tv_usec = 500000;
 549     if ((sl = select(mfd + 1, &fds, NULL, NULL, &tv)) < 0)
 550     {
 551       if (errno != EINTR)
 552         Error(ERR_EXIT_NETWORK_SERVER, "select() failed");
 553       else
 554         continue;
 555     }
 556
 557     if (sl < 0)
 558       continue;
 559
 560     if (sl == 0)
 561       continue;
 562
 563     if (FD_ISSET(lfd, &fds))
 564     {
 565       int newfd, slen;
 566
 567       slen = sizeof(saddr);
 568       newfd = accept(lfd, (struct sockaddr *)&saddr, &slen);
 569       if (newfd < 0)
 570       {
 571         if (errno != EINTR)
 572           Error(ERR_EXIT_NETWORK_SERVER, "accept() failed");
 573       }
 574       else
 575       {
 576         if (tcp != -1)
 577         {
 578           on = 1;
 579           setsockopt(newfd, tcp, TCP_NODELAY, (char *)&on, sizeof(int));
 580         }
 581         AddPlayer(newfd);
 582       }
 583       continue;
 584     }
 585
 586     player = first_player;
 587
 588     do
 589     {
 590       if (FD_ISSET(player->fd, &fds))
 591       {
 592         r = read(player->fd, player->readbuffer + player->nread, MAX_BUFFER_SIZE - player->nread);
 593         if (r <= 0)
 594         {
 595           if (options.verbose)
 596             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 597                   player->number, player->player_name);
 598           RemovePlayer(player);
 599           interrupt = 1;
 600           break;
 601         }
 602         player->nread += r;
 603         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 604         {
 605           len = player->readbuffer[3];
 606           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 607           {
 608             if (options.verbose)
 609               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 610                     player->number, player->player_name);
 611             RemovePlayer(player);
 612             interrupt = 1;
 613             break;
 614           }
 615           memcpy(buffer, &player->readbuffer[4], len);
 616           player->nread -= 4 + len;
 617           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 618
 619           buffer[0] = player->number;
 620           if (!player->introduced && buffer[1] != OP_PLAYER_NAME)
 621           {
 622             if (options.verbose)
 623               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME)", buffer[0], buffer[1]);
 624
 625             RemovePlayer(player);
 626             interrupt = 1;
 627             break;
 628           }
 629
 630           switch(buffer[1])
 631           {
 632             case OP_PLAYER_NAME:
 633               Handle_OP_PLAYER_NAME(player, len);
 634               break;
 635
 636             case OP_PROTOCOL_VERSION:
 637               Handle_OP_PROTOCOL_VERSION(player, len);
 638               break;
 639
 640             case OP_NUMBER_WANTED:
 641               Handle_OP_NUMBER_WANTED(player);
 642               break;
 643
 644             case OP_START_PLAYING:
 645               Handle_OP_START_PLAYING(player);
 646               break;
 647
 648             case OP_PAUSE_PLAYING:
 649               Handle_OP_PAUSE_PLAYING(player);
 650               break;
 651
 652             case OP_CONTINUE_PLAYING:
 653               Handle_OP_CONTINUE_PLAYING(player);
 654               break;
 655
 656             case OP_STOP_PLAYING:
 657               Handle_OP_STOP_PLAYING(player);
 658               break;
 659
 660             case OP_MOVE_PLAYER:
 661               Handle_OP_MOVE_PLAYER(player);
 662               break;
 663
 664             case OP_BROADCAST_MESSAGE:
 665               buffer[len] = '\0';
 666               if (options.verbose)
 667                 Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
 668                       player->number, player->player_name, &buffer[2]);
 669               broadcast(player, len, 0);
 670               break;
 671
 672             default:
 673               if (options.verbose)
 674                 Error(ERR_NETWORK_SERVER,
 675                       "unknown opcode %d from client %d (%s)",
 676                       buffer[0], player->number, player->player_name);
 677           }
 678         }
 679       }
 680
 681       if (player && !interrupt)
 682         player = player->next;
 683     }
 684     while (player && !interrupt);
 685   }
 686 }
 687
 688 #endif /* PLATFORM_UNIX */