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->active || !activeonly) && player->introduced)
  94       addtobuffer(player, realbuffer, 4 + len);
  95 }
  96
  97 static void sendtoone(struct NetworkServerPlayerInfo *to, int len)
  98 {
  99   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
 100   realbuffer[3] = (unsigned char)len;
 101   addtobuffer(to, realbuffer, 4 + len);
 102 }
 103
 104 static void RemovePlayer(struct NetworkServerPlayerInfo *player)
 105 {
 106   struct NetworkServerPlayerInfo *v;
 107
 108   if (options.verbose)
 109     Error(ERR_NETWORK_SERVER, "dropping client %d (%s)",
 110           player->number, player->player_name);
 111
 112   if (player == first_player)
 113     first_player = player->next;
 114   else
 115   {
 116     for (v=first_player; v; v=v->next)
 117     {
 118       if (v->next && v->next == player)
 119       {
 120         v->next = player->next;
 121         break;
 122       }
 123     }
 124   }
 125   close(player->fd);
 126
 127   if (player->introduced)
 128   {
 129     buffer[0] = player->number;
 130     buffer[1] = OP_PLAYER_DISCONNECTED;
 131     broadcast(player, 2, 0);
 132   }
 133
 134   free(player);
 135   clients--;
 136
 137   if (onceonly && clients == 0)
 138   {
 139     if (options.verbose)
 140     {
 141       Error(ERR_NETWORK_SERVER, "no clients left");
 142       Error(ERR_NETWORK_SERVER, "aborting");
 143     }
 144     exit(0);
 145   }
 146 }
 147
 148 static void AddPlayer(int fd)
 149 {
 150   struct NetworkServerPlayerInfo *player, *v;
 151   unsigned char nxn;
 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   first_player = player;
 166
 167   nxn = 1;
 168
 169  again:
 170   v = player->next;
 171   while(v)
 172   {
 173     if (v->number == nxn)
 174     {
 175       nxn++;
 176       goto again;
 177     }
 178     v = v->next;
 179   }
 180
 181   player->number = nxn;
 182   if (options.verbose)
 183     Error(ERR_NETWORK_SERVER, "client %d connecting from %s",
 184           nxn, inet_ntoa(saddr.sin_addr));
 185   clients++;
 186
 187   buffer[0] = 0;
 188   buffer[1] = OP_YOUR_NUMBER;
 189   buffer[2] = player->number;
 190   sendtoone(player, 3);
 191 }
 192
 193 static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player,
 194                                        unsigned int len)
 195 {
 196   if (len != 5 ||
 197       buffer[2] != PROTOCOL_VERSION_1 ||
 198       buffer[3] != PROTOCOL_VERSION_2)
 199   {
 200     if (options.verbose)
 201       Error(ERR_NETWORK_SERVER,
 202             "client %d (%s) has wrong protocol version %d.%d.%d",
 203             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 204
 205     buffer[0] = 0;
 206     buffer[1] = OP_BAD_PROTOCOL_VERSION;
 207     buffer[2] = PROTOCOL_VERSION_1;
 208     buffer[3] = PROTOCOL_VERSION_2;
 209     buffer[4] = PROTOCOL_VERSION_3;
 210     sendtoone(player, 5);
 211     flushuser(player);
 212
 213     RemovePlayer(player);
 214     interrupt = 1;
 215   }
 216   else
 217   {
 218     if (options.verbose)
 219       Error(ERR_NETWORK_SERVER,
 220             "client %d (%s) uses protocol version %d.%d.%d",
 221             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 222   }
 223 }
 224
 225 static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 226 {
 227   struct NetworkServerPlayerInfo *v;
 228   int client_nr = player->number;
 229   int nr_wanted = buffer[2];
 230   int nr_is_free = 1;
 231
 232   if (options.verbose)
 233       Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
 234             player->number, player->player_name, nr_wanted);
 235
 236   for (v=first_player; v; v=v->next)
 237   {
 238     if (v->number == nr_wanted)
 239     {
 240       nr_is_free = 0;
 241       break;
 242     }
 243   }
 244
 245   if (options.verbose)
 246   {
 247     if (nr_is_free)
 248       Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
 249             player->number, player->player_name, nr_wanted);
 250     else if (player->number == nr_wanted)
 251       Error(ERR_NETWORK_SERVER, "client %d (%s) still has # %d",
 252             player->number, player->player_name, nr_wanted);
 253     else
 254       Error(ERR_NETWORK_SERVER,
 255             "client %d (%s) cannot switch (client %d still exists)",
 256             player->number, player->player_name, nr_wanted);
 257   }
 258
 259   if (nr_is_free)
 260     player->number = nr_wanted;
 261
 262   buffer[0] = client_nr;
 263   buffer[1] = OP_NUMBER_WANTED;
 264   buffer[2] = nr_wanted;
 265   buffer[3] = player->number;
 266
 267   /*
 268   sendtoone(player, 4);
 269   */
 270
 271   broadcast(NULL, 4, 0);
 272 }
 273
 274 static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player,
 275                                   unsigned int len)
 276 {
 277   struct NetworkServerPlayerInfo *v;
 278   int i;
 279
 280   if (len>16)
 281     len=16;
 282   memcpy(player->player_name, &buffer[2], len-2);
 283   player->player_name[len-2] = 0;
 284   for (i=0; i<len-2; i++)
 285   {
 286     if (player->player_name[i] < ' ' ||
 287         ((unsigned char)(player->player_name[i]) > 0x7e &&
 288          (unsigned char)(player->player_name[i]) <= 0xa0))
 289     {
 290       player->player_name[i] = 0;
 291       break;
 292     }
 293   }
 294
 295   if (!player->introduced)
 296   {
 297     buffer[0] = player->number;
 298     buffer[1] = OP_PLAYER_CONNECTED;
 299     broadcast(player, 2, 0);
 300   }
 301
 302   if (options.verbose)
 303     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 304           player->number, player->player_name);
 305   buffer[1] = OP_PLAYER_NAME;
 306   broadcast(player, len, 0);
 307
 308   if (!player->introduced)
 309   {
 310     for (v=first_player; v; v=v->next)
 311     {
 312       if (v != player && v->introduced)
 313       {
 314         buffer[0] = v->number;
 315         buffer[1] = OP_PLAYER_CONNECTED;
 316         sendtoone(player, 2);
 317         buffer[1] = OP_PLAYER_NAME;
 318         memcpy(&buffer[2], v->player_name, 14);
 319         sendtoone(player, 2+strlen(v->player_name));
 320       }
 321     }
 322   }
 323
 324   player->introduced = 1;
 325 }
 326
 327 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 328 {
 329   struct NetworkServerPlayerInfo *v, *w;
 330
 331   if (options.verbose)
 332     Error(ERR_NETWORK_SERVER,
 333           "client %d (%s) starts game [level %d from levedir %d (%s)]",
 334           player->number, player->player_name,
 335           (buffer[2] << 8) + buffer[3],
 336           (buffer[4] << 8) + buffer[5],
 337           &buffer[6]);
 338
 339   for (w=first_player; w; w=w->next)
 340     if (w->introduced)
 341       w->active = 1;
 342
 343   /* reset frame counter */
 344   ServerFrameCounter = 0;
 345
 346   /* reset player actions */
 347   for (v=first_player; v; v=v->next)
 348   {
 349     v->action = 0;
 350     v->action_received = FALSE;
 351   }
 352
 353   broadcast(NULL, 10 + strlen((char *)&buffer[10])+1, 0);
 354 }
 355
 356 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 357 {
 358   if (options.verbose)
 359     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 360           player->number, player->player_name);
 361   broadcast(NULL, 2, 0);
 362 }
 363
 364 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 365 {
 366   if (options.verbose)
 367     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 368           player->number, player->player_name);
 369   broadcast(NULL, 2, 0);
 370 }
 371
 372 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 373 {
 374   if (options.verbose)
 375     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game",
 376           player->number, player->player_name);
 377   broadcast(NULL, 2, 0);
 378 }
 379
 380 static void Handle_OP_MOVE_FIGURE(struct NetworkServerPlayerInfo *player)
 381 {
 382   struct NetworkServerPlayerInfo *v;
 383   int last_client_nr = 0;
 384   int i;
 385
 386   /* store player action */
 387   for (v=first_player; v; v=v->next)
 388   {
 389     if (v->number == player->number)
 390     {
 391       v->action = buffer[2];
 392       v->action_received = TRUE;
 393     }
 394   }
 395
 396   /* check if server received action from each player */
 397   for (v=first_player; v; v=v->next)
 398   {
 399     if (!v->action_received)
 400       return;
 401
 402     if (v->number > last_client_nr)
 403       last_client_nr = v->number;
 404   }
 405
 406   /* initialize all player actions to zero */
 407   for (i=0; i<last_client_nr; i++)
 408     buffer[6 + i] = 0;
 409
 410   /* broadcast actions of all players to all players */
 411   for (v=first_player; v; v=v->next)
 412   {
 413     buffer[6 + v->number-1] = v->action;
 414     v->action = 0;
 415     v->action_received = FALSE;
 416   }
 417
 418   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 419   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 420   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 421   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 422
 423   broadcast(NULL, 6 + last_client_nr, 0);
 424
 425   ServerFrameCounter++;
 426 }
 427
 428 void NetworkServer(int port, int serveronly)
 429 {
 430   int i, sl, on;
 431   struct NetworkServerPlayerInfo *player;
 432   int mfd;
 433   int r;
 434   unsigned int len;
 435   struct protoent *tcpproto;
 436   struct timeval tv;
 437   int is_daemon = 0;
 438
 439 #ifndef NeXT
 440   struct sigaction sact;
 441 #endif
 442
 443   if (port == 0)
 444     port = DEFAULT_SERVER_PORT;
 445
 446   if (!serveronly)
 447     onceonly = 1;
 448
 449   if ((tcpproto = getprotobyname("tcp")) != NULL)
 450     tcp = tcpproto->p_proto;
 451
 452 #ifdef NeXT
 453   signal(SIGPIPE, SIG_IGN);
 454 #else
 455   sact.sa_handler = SIG_IGN;
 456   sigemptyset(&sact.sa_mask);
 457   sact.sa_flags = 0;
 458   sigaction(SIGPIPE, &sact, NULL);
 459 #endif
 460
 461
 462   if ((lfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
 463     Error(ERR_EXIT_NETWORK_SERVER, "socket() failed");
 464
 465   saddr.sin_family = AF_INET;
 466   saddr.sin_addr.s_addr = htonl(INADDR_ANY);
 467   saddr.sin_port = htons(port);
 468
 469   on = 1;
 470
 471   setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(int));
 472   if (bind(lfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0)
 473     Error(ERR_EXIT_NETWORK_SERVER, "bind() failed");
 474
 475   listen(lfd, 5);
 476
 477   if (is_daemon)
 478   {
 479     /* become a daemon, breaking all ties with the controlling terminal */
 480     options.verbose = FALSE;
 481     for (i=0; i<255; i++)
 482     {
 483       if (i != lfd)
 484         close(i);
 485     }
 486
 487     if (fork())
 488       exit(0);
 489     setsid();
 490     if (fork())
 491       exit(0);
 492     chdir("/");
 493
 494     /* open a fake stdin, stdout, stderr, just in case */
 495     open("/dev/null", O_RDONLY);
 496     open("/dev/null", O_WRONLY);
 497     open("/dev/null", O_WRONLY);
 498   }
 499
 500   if (options.verbose)
 501   {
 502     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 503     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 504           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 505   }
 506
 507   while(1)
 508   {
 509     interrupt = 0;
 510
 511     for (player=first_player; player; player=player->next)
 512       flushuser(player);
 513
 514     FD_ZERO(&fds);
 515     mfd = lfd;
 516     player = first_player;
 517     while (player)
 518     {
 519       FD_SET(player->fd, &fds);
 520       if (player->fd > mfd)
 521         mfd = player->fd;
 522       player = player->next;
 523     }
 524     FD_SET(lfd, &fds);
 525     tv.tv_sec = 0;
 526     tv.tv_usec = 500000;
 527     if ((sl = select(mfd + 1, &fds, NULL, NULL, &tv)) < 0)
 528     {
 529       if (errno != EINTR)
 530         Error(ERR_EXIT_NETWORK_SERVER, "select() failed");
 531       else
 532         continue;
 533     }
 534
 535     if (sl < 0)
 536       continue;
 537
 538     if (sl == 0)
 539       continue;
 540
 541     if (FD_ISSET(lfd, &fds))
 542     {
 543       int newfd, slen;
 544
 545       slen = sizeof(saddr);
 546       newfd = accept(lfd, (struct sockaddr *)&saddr, &slen);
 547       if (newfd < 0)
 548       {
 549         if (errno != EINTR)
 550           Error(ERR_EXIT_NETWORK_SERVER, "accept() failed");
 551       }
 552       else
 553       {
 554         if (tcp != -1)
 555         {
 556           on = 1;
 557           setsockopt(newfd, tcp, TCP_NODELAY, (char *)&on, sizeof(int));
 558         }
 559         AddPlayer(newfd);
 560       }
 561       continue;
 562     }
 563
 564     player = first_player;
 565
 566     do
 567     {
 568       if (FD_ISSET(player->fd, &fds))
 569       {
 570         r = read(player->fd, player->readbuffer + player->nread, MAX_BUFFER_SIZE - player->nread);
 571         if (r <= 0)
 572         {
 573           if (options.verbose)
 574             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 575                   player->number, player->player_name);
 576           RemovePlayer(player);
 577           interrupt = 1;
 578           break;
 579         }
 580         player->nread += r;
 581         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 582         {
 583           len = player->readbuffer[3];
 584           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 585           {
 586             if (options.verbose)
 587               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 588                     player->number, player->player_name);
 589             RemovePlayer(player);
 590             interrupt = 1;
 591             break;
 592           }
 593           memcpy(buffer, &player->readbuffer[4], len);
 594           player->nread -= 4 + len;
 595           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 596
 597           buffer[0] = player->number;
 598           if (!player->introduced && buffer[1] != OP_PLAYER_NAME)
 599           {
 600             if (options.verbose)
 601               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME)", buffer[0], buffer[1]);
 602
 603             RemovePlayer(player);
 604             interrupt = 1;
 605             break;
 606           }
 607
 608           switch(buffer[1])
 609           {
 610             case OP_PLAYER_NAME:
 611               Handle_OP_PLAYER_NAME(player, len);
 612               break;
 613
 614             case OP_PROTOCOL_VERSION:
 615               Handle_OP_PROTOCOL_VERSION(player, len);
 616               break;
 617
 618             case OP_NUMBER_WANTED:
 619               Handle_OP_NUMBER_WANTED(player);
 620               break;
 621
 622             case OP_START_PLAYING:
 623               Handle_OP_START_PLAYING(player);
 624               break;
 625
 626             case OP_PAUSE_PLAYING:
 627               Handle_OP_PAUSE_PLAYING(player);
 628               break;
 629
 630             case OP_CONTINUE_PLAYING:
 631               Handle_OP_CONTINUE_PLAYING(player);
 632               break;
 633
 634             case OP_STOP_PLAYING:
 635               Handle_OP_STOP_PLAYING(player);
 636               break;
 637
 638             case OP_MOVE_FIGURE:
 639               Handle_OP_MOVE_FIGURE(player);
 640               break;
 641
 642             case OP_BROADCAST_MESSAGE:
 643               buffer[len] = '\0';
 644               if (options.verbose)
 645                 Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
 646                       player->number, player->player_name, &buffer[2]);
 647               broadcast(player, len, 0);
 648               break;
 649
 650             default:
 651               if (options.verbose)
 652                 Error(ERR_NETWORK_SERVER,
 653                       "unknown opcode %d from client %d (%s)",
 654                       buffer[0], player->number, player->player_name);
 655           }
 656         }
 657       }
 658
 659       if (player && !interrupt)
 660         player = player->next;
 661     }
 662     while (player && !interrupt);
 663   }
 664 }
 665
 666 #endif /* PLATFORM_UNIX */