src/netserv.c

   1 /***********************************************************
   2 *  Rocks'n'Diamonds -- McDuffin Strikes Back!              *
   3 *----------------------------------------------------------*
   4 *  (c) 1995-98 Artsoft Entertainment                       *
   5 *              Holger Schemel                              *
   6 *              Oststrasse 11a                              *
   7 *              33604 Bielefeld                             *
   8 *              phone: ++49 +521 290471                     *
   9 *              email: aeglos@valinor.owl.de                *
  10 *----------------------------------------------------------*
  11 *  network.c                                               *
  12 ***********************************************************/
  13
  14 #ifndef MSDOS
  15
  16 #include <unistd.h>
  17 #include <fcntl.h>
  18 #include <sys/time.h>
  19 #include <signal.h>
  20 #include <sys/socket.h>
  21 #include <errno.h>
  22 #include <string.h>
  23 #include <netinet/in.h>
  24 #include <netinet/tcp.h>
  25 #include <arpa/inet.h>
  26 #include <netdb.h>
  27
  28 #include "netserv.h"
  29 #include "misc.h"
  30
  31 static int clients = 0;
  32 static int onceonly = 0;
  33
  34 struct NetworkServerPlayerInfo
  35 {
  36   int fd;
  37   char player_name[16];
  38   unsigned char number;
  39   struct NetworkServerPlayerInfo *next;
  40   char active;
  41   char introduced;
  42   unsigned char readbuffer[MAX_BUFFER_SIZE];
  43   unsigned char writbuffer[MAX_BUFFER_SIZE];
  44   int nread, nwrite;
  45   byte action;
  46   boolean action_received;
  47 };
  48
  49 static struct NetworkServerPlayerInfo *first_player = NULL;
  50
  51 #define NEXT(player) ((player)->next ? (player)->next : first_player)
  52
  53 static struct sockaddr_in saddr;
  54 static int lfd;
  55 static unsigned char realbuffer[512], *buffer = realbuffer + 4;
  56
  57 static int interrupt;
  58 static int tcp = -1;
  59
  60 static unsigned long ServerFrameCounter = 0;
  61
  62 static fd_set fds;
  63
  64 static void addtobuffer(struct NetworkServerPlayerInfo *player,
  65                         unsigned char *b, int len)
  66 {
  67   if (player->nwrite + len >= MAX_BUFFER_SIZE)
  68     Error(ERR_EXIT_NETWORK_SERVER,
  69           "internal error: network send buffer overflow");
  70
  71   memcpy(player->writbuffer + player->nwrite, b, len);
  72   player->nwrite += len;
  73 }
  74
  75 static void flushuser(struct NetworkServerPlayerInfo *player)
  76 {
  77   if (player->nwrite)
  78   {
  79     write(player->fd, player->writbuffer, player->nwrite);
  80     player->nwrite = 0;
  81   }
  82 }
  83
  84 static void broadcast(struct NetworkServerPlayerInfo *except,
  85                       int len, int activeonly)
  86 {
  87   struct NetworkServerPlayerInfo *player;
  88
  89   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  90   realbuffer[3] = (unsigned char)len;
  91   for (player=first_player; player; player=player->next)
  92     if (player != except && (player->active || !activeonly) && player->introduced)
  93       addtobuffer(player, realbuffer, 4 + len);
  94 }
  95
  96 static void sendtoone(struct NetworkServerPlayerInfo *to, int len)
  97 {
  98   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  99   realbuffer[3] = (unsigned char)len;
 100   addtobuffer(to, realbuffer, 4 + len);
 101 }
 102
 103 static void RemovePlayer(struct NetworkServerPlayerInfo *player)
 104 {
 105   struct NetworkServerPlayerInfo *v;
 106
 107   if (options.verbose)
 108     Error(ERR_NETWORK_SERVER, "dropping client %d (%s)",
 109           player->number, player->player_name);
 110
 111   if (player == first_player)
 112     first_player = player->next;
 113   else
 114   {
 115     for (v=first_player; v; v=v->next)
 116     {
 117       if (v->next && v->next == player)
 118       {
 119         v->next = player->next;
 120         break;
 121       }
 122     }
 123   }
 124   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(int fd)
 148 {
 149   struct NetworkServerPlayerInfo *player, *v;
 150   unsigned char nxn;
 151
 152   player = checked_malloc(sizeof (struct NetworkServerPlayerInfo));
 153
 154   player->fd = fd;
 155   player->player_name[0] = 0;
 156   player->next = first_player;
 157   player->active = 0;
 158   player->nread = 0;
 159   player->nwrite = 0;
 160   player->introduced = 0;
 161   player->action = 0;
 162   player->action_received = FALSE;
 163
 164   first_player = player;
 165
 166   nxn = 1;
 167
 168  again:
 169   v = player->next;
 170   while(v)
 171   {
 172     if (v->number == nxn)
 173     {
 174       nxn++;
 175       goto again;
 176     }
 177     v = v->next;
 178   }
 179
 180   player->number = nxn;
 181   if (options.verbose)
 182     Error(ERR_NETWORK_SERVER, "client %d connecting from %s",
 183           nxn, inet_ntoa(saddr.sin_addr));
 184   clients++;
 185
 186   buffer[0] = 0;
 187   buffer[1] = OP_YOUR_NUMBER;
 188   buffer[2] = player->number;
 189   sendtoone(player, 3);
 190 }
 191
 192 static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player,
 193                                        unsigned int len)
 194 {
 195   if (len != 5 ||
 196       buffer[2] != PROTOCOL_VERSION_1 ||
 197       buffer[3] != PROTOCOL_VERSION_2)
 198   {
 199     if (options.verbose)
 200       Error(ERR_NETWORK_SERVER,
 201             "client %d (%s) has wrong protocol version %d.%d.%d",
 202             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 203
 204     buffer[0] = 0;
 205     buffer[1] = OP_BAD_PROTOCOL_VERSION;
 206     buffer[2] = PROTOCOL_VERSION_1;
 207     buffer[3] = PROTOCOL_VERSION_2;
 208     buffer[4] = PROTOCOL_VERSION_3;
 209     sendtoone(player, 5);
 210     flushuser(player);
 211
 212     RemovePlayer(player);
 213     interrupt = 1;
 214   }
 215   else
 216   {
 217     if (options.verbose)
 218       Error(ERR_NETWORK_SERVER,
 219             "client %d (%s) uses protocol version %d.%d.%d",
 220             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 221   }
 222 }
 223
 224 static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 225 {
 226   struct NetworkServerPlayerInfo *v;
 227   int client_nr = player->number;
 228   int nr_wanted = buffer[2];
 229   int nr_is_free = 1;
 230
 231   if (options.verbose)
 232       Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
 233             player->number, player->player_name, nr_wanted);
 234
 235   for (v=first_player; v; v=v->next)
 236   {
 237     if (v->number == nr_wanted)
 238     {
 239       nr_is_free = 0;
 240       break;
 241     }
 242   }
 243
 244   if (options.verbose)
 245   {
 246     if (nr_is_free)
 247       Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
 248             player->number, player->player_name, nr_wanted);
 249     else if (player->number == nr_wanted)
 250       Error(ERR_NETWORK_SERVER, "client %d (%s) still has # %d",
 251             player->number, player->player_name, nr_wanted);
 252     else
 253       Error(ERR_NETWORK_SERVER,
 254             "client %d (%s) cannot switch (client %d still exists)",
 255             player->number, player->player_name, nr_wanted);
 256   }
 257
 258   if (nr_is_free)
 259     player->number = nr_wanted;
 260
 261   buffer[0] = client_nr;
 262   buffer[1] = OP_NUMBER_WANTED;
 263   buffer[2] = nr_wanted;
 264   buffer[3] = player->number;
 265
 266   /*
 267   sendtoone(player, 4);
 268   */
 269
 270   broadcast(NULL, 4, 0);
 271 }
 272
 273 static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player,
 274                                   unsigned int len)
 275 {
 276   struct NetworkServerPlayerInfo *v;
 277   int i;
 278
 279   if (len>16)
 280     len=16;
 281   memcpy(player->player_name, &buffer[2], len-2);
 282   player->player_name[len-2] = 0;
 283   for (i=0; i<len-2; i++)
 284   {
 285     if (player->player_name[i] < ' ' ||
 286         ((unsigned char)(player->player_name[i]) > 0x7e &&
 287          (unsigned char)(player->player_name[i]) <= 0xa0))
 288     {
 289       player->player_name[i] = 0;
 290       break;
 291     }
 292   }
 293
 294   if (!player->introduced)
 295   {
 296     buffer[0] = player->number;
 297     buffer[1] = OP_PLAYER_CONNECTED;
 298     broadcast(player, 2, 0);
 299   }
 300
 301   if (options.verbose)
 302     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 303           player->number, player->player_name);
 304   buffer[1] = OP_PLAYER_NAME;
 305   broadcast(player, len, 0);
 306
 307   if (!player->introduced)
 308   {
 309     for (v=first_player; v; v=v->next)
 310     {
 311       if (v != player && v->introduced)
 312       {
 313         buffer[0] = v->number;
 314         buffer[1] = OP_PLAYER_CONNECTED;
 315         sendtoone(player, 2);
 316         buffer[1] = OP_PLAYER_NAME;
 317         memcpy(&buffer[2], v->player_name, 14);
 318         sendtoone(player, 2+strlen(v->player_name));
 319       }
 320     }
 321   }
 322
 323   player->introduced = 1;
 324 }
 325
 326 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 327 {
 328   struct NetworkServerPlayerInfo *v, *w;
 329
 330   if (options.verbose)
 331     Error(ERR_NETWORK_SERVER,
 332           "client %d (%s) starts game [level %d from levedir %d (%s)]",
 333           player->number, player->player_name,
 334           (buffer[2] << 8) + buffer[3],
 335           (buffer[4] << 8) + buffer[5],
 336           &buffer[6]);
 337
 338   for (w=first_player; w; w=w->next)
 339     if (w->introduced)
 340       w->active = 1;
 341
 342   /* reset frame counter */
 343   ServerFrameCounter = 0;
 344
 345   /* reset player actions */
 346   for (v=first_player; v; v=v->next)
 347   {
 348     v->action = 0;
 349     v->action_received = FALSE;
 350   }
 351
 352   broadcast(NULL, 10 + strlen((char *)&buffer[10])+1, 0);
 353 }
 354
 355 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 356 {
 357   if (options.verbose)
 358     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 359           player->number, player->player_name);
 360   broadcast(NULL, 2, 0);
 361 }
 362
 363 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 364 {
 365   if (options.verbose)
 366     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 367           player->number, player->player_name);
 368   broadcast(NULL, 2, 0);
 369 }
 370
 371 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 372 {
 373   if (options.verbose)
 374     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game",
 375           player->number, player->player_name);
 376   broadcast(NULL, 2, 0);
 377 }
 378
 379 static void Handle_OP_MOVE_FIGURE(struct NetworkServerPlayerInfo *player)
 380 {
 381   struct NetworkServerPlayerInfo *v;
 382   int last_client_nr = 0;
 383   int i;
 384
 385   /* store player action */
 386   for (v=first_player; v; v=v->next)
 387   {
 388     if (v->number == player->number)
 389     {
 390       v->action = buffer[2];
 391       v->action_received = TRUE;
 392     }
 393   }
 394
 395   /* check if server received action from each player */
 396   for (v=first_player; v; v=v->next)
 397   {
 398     if (!v->action_received)
 399       return;
 400
 401     if (v->number > last_client_nr)
 402       last_client_nr = v->number;
 403   }
 404
 405   /* initialize all player actions to zero */
 406   for (i=0; i<last_client_nr; i++)
 407     buffer[6 + i] = 0;
 408
 409   /* broadcast actions of all players to all players */
 410   for (v=first_player; v; v=v->next)
 411   {
 412     buffer[6 + v->number-1] = v->action;
 413     v->action = 0;
 414     v->action_received = FALSE;
 415   }
 416
 417   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 418   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 419   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 420   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 421
 422   broadcast(NULL, 6 + last_client_nr, 0);
 423
 424   ServerFrameCounter++;
 425 }
 426
 427 void NetworkServer(int port, int serveronly)
 428 {
 429   int i, sl, on;
 430   struct NetworkServerPlayerInfo *player;
 431   int mfd;
 432   int r;
 433   unsigned int len;
 434   struct protoent *tcpproto;
 435   struct timeval tv;
 436   int is_daemon = 0;
 437
 438 #ifndef NeXT
 439   struct sigaction sact;
 440 #endif
 441
 442   if (port == 0)
 443     port = DEFAULT_SERVER_PORT;
 444
 445   if (!serveronly)
 446     onceonly = 1;
 447
 448   if ((tcpproto = getprotobyname("tcp")) != NULL)
 449     tcp = tcpproto->p_proto;
 450
 451 #ifdef NeXT
 452   signal(SIGPIPE, SIG_IGN);
 453 #else
 454   sact.sa_handler = SIG_IGN;
 455   sigemptyset(&sact.sa_mask);
 456   sact.sa_flags = 0;
 457   sigaction(SIGPIPE, &sact, NULL);
 458 #endif
 459
 460
 461   if ((lfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
 462     Error(ERR_EXIT_NETWORK_SERVER, "socket() failed");
 463
 464   saddr.sin_family = AF_INET;
 465   saddr.sin_addr.s_addr = htonl(INADDR_ANY);
 466   saddr.sin_port = htons(port);
 467
 468   on = 1;
 469
 470   setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(int));
 471   if (bind(lfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0)
 472     Error(ERR_EXIT_NETWORK_SERVER, "bind() failed");
 473
 474   listen(lfd, 5);
 475
 476   if (is_daemon)
 477   {
 478     /* become a daemon, breaking all ties with the controlling terminal */
 479     options.verbose = 0;
 480     for (i=0; i<255; i++)
 481     {
 482       if (i != lfd)
 483         close(i);
 484     }
 485
 486     if (fork())
 487       exit(0);
 488     setsid();
 489     if (fork())
 490       exit(0);
 491     chdir("/");
 492
 493     /* open a fake stdin, stdout, stderr, just in case */
 494     open("/dev/null", O_RDONLY);
 495     open("/dev/null", O_WRONLY);
 496     open("/dev/null", O_WRONLY);
 497   }
 498
 499   if (options.verbose)
 500   {
 501     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 502     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 503           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 504   }
 505
 506   while(1)
 507   {
 508     interrupt = 0;
 509
 510     for (player=first_player; player; player=player->next)
 511       flushuser(player);
 512
 513     FD_ZERO(&fds);
 514     mfd = lfd;
 515     player = first_player;
 516     while (player)
 517     {
 518       FD_SET(player->fd, &fds);
 519       if (player->fd > mfd)
 520         mfd = player->fd;
 521       player = player->next;
 522     }
 523     FD_SET(lfd, &fds);
 524     tv.tv_sec = 0;
 525     tv.tv_usec = 500000;
 526     if ((sl = select(mfd + 1, &fds, NULL, NULL, &tv)) < 0)
 527     {
 528       if (errno != EINTR)
 529         Error(ERR_EXIT_NETWORK_SERVER, "select() failed");
 530       else
 531         continue;
 532     }
 533
 534     if (sl < 0)
 535       continue;
 536
 537     if (sl == 0)
 538       continue;
 539
 540     if (FD_ISSET(lfd, &fds))
 541     {
 542       int newfd, slen;
 543
 544       slen = sizeof(saddr);
 545       newfd = accept(lfd, (struct sockaddr *)&saddr, &slen);
 546       if (newfd < 0)
 547       {
 548         if (errno != EINTR)
 549           Error(ERR_EXIT_NETWORK_SERVER, "accept() failed");
 550       }
 551       else
 552       {
 553         if (tcp != -1)
 554         {
 555           on = 1;
 556           setsockopt(newfd, tcp, TCP_NODELAY, (char *)&on, sizeof(int));
 557         }
 558         AddPlayer(newfd);
 559       }
 560       continue;
 561     }
 562
 563     player = first_player;
 564
 565     do
 566     {
 567       if (FD_ISSET(player->fd, &fds))
 568       {
 569         r = read(player->fd, player->readbuffer + player->nread, MAX_BUFFER_SIZE - player->nread);
 570         if (r <= 0)
 571         {
 572           if (options.verbose)
 573             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 574                   player->number, player->player_name);
 575           RemovePlayer(player);
 576           interrupt = 1;
 577           break;
 578         }
 579         player->nread += r;
 580         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 581         {
 582           len = player->readbuffer[3];
 583           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 584           {
 585             if (options.verbose)
 586               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 587                     player->number, player->player_name);
 588             RemovePlayer(player);
 589             interrupt = 1;
 590             break;
 591           }
 592           memcpy(buffer, &player->readbuffer[4], len);
 593           player->nread -= 4 + len;
 594           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 595
 596           buffer[0] = player->number;
 597           if (!player->introduced && buffer[1] != OP_PLAYER_NAME)
 598           {
 599             if (options.verbose)
 600               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME)", buffer[0], buffer[1]);
 601
 602             RemovePlayer(player);
 603             interrupt = 1;
 604             break;
 605           }
 606
 607           switch(buffer[1])
 608           {
 609             case OP_PLAYER_NAME:
 610               Handle_OP_PLAYER_NAME(player, len);
 611               break;
 612
 613             case OP_PROTOCOL_VERSION:
 614               Handle_OP_PROTOCOL_VERSION(player, len);
 615               break;
 616
 617             case OP_NUMBER_WANTED:
 618               Handle_OP_NUMBER_WANTED(player);
 619               break;
 620
 621             case OP_START_PLAYING:
 622               Handle_OP_START_PLAYING(player);
 623               break;
 624
 625             case OP_PAUSE_PLAYING:
 626               Handle_OP_PAUSE_PLAYING(player);
 627               break;
 628
 629             case OP_CONTINUE_PLAYING:
 630               Handle_OP_CONTINUE_PLAYING(player);
 631               break;
 632
 633             case OP_STOP_PLAYING:
 634               Handle_OP_STOP_PLAYING(player);
 635               break;
 636
 637             case OP_MOVE_FIGURE:
 638               Handle_OP_MOVE_FIGURE(player);
 639               break;
 640
 641             case OP_BROADCAST_MESSAGE:
 642               buffer[len] = '\0';
 643               if (options.verbose)
 644                 Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
 645                       player->number, player->player_name, &buffer[2]);
 646               broadcast(player, len, 0);
 647               break;
 648
 649             default:
 650               if (options.verbose)
 651                 Error(ERR_NETWORK_SERVER,
 652                       "unknown opcode %d from client %d (%s)",
 653                       buffer[0], player->number, player->player_name);
 654           }
 655         }
 656       }
 657
 658       if (player && !interrupt)
 659         player = player->next;
 660     }
 661     while (player && !interrupt);
 662   }
 663 }
 664
 665 #endif /* !MSDOS */