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   unsigned 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         (player->player_name[i] > 0x7e && player->player_name[i] <= 0xa0))
 287     {
 288       player->player_name[i] = 0;
 289       break;
 290     }
 291   }
 292
 293   if (!player->introduced)
 294   {
 295     buffer[0] = player->number;
 296     buffer[1] = OP_PLAYER_CONNECTED;
 297     broadcast(player, 2, 0);
 298   }
 299
 300   if (options.verbose)
 301     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 302           player->number, player->player_name);
 303   buffer[1] = OP_PLAYER_NAME;
 304   broadcast(player, len, 0);
 305
 306   if (!player->introduced)
 307   {
 308     for (v=first_player; v; v=v->next)
 309     {
 310       if (v != player && v->introduced)
 311       {
 312         buffer[0] = v->number;
 313         buffer[1] = OP_PLAYER_CONNECTED;
 314         sendtoone(player, 2);
 315         buffer[1] = OP_PLAYER_NAME;
 316         memcpy(&buffer[2], v->player_name, 14);
 317         sendtoone(player, 2+strlen(v->player_name));
 318       }
 319     }
 320   }
 321
 322   player->introduced = 1;
 323 }
 324
 325 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 326 {
 327   struct NetworkServerPlayerInfo *v, *w;
 328
 329   if (options.verbose)
 330     Error(ERR_NETWORK_SERVER,
 331           "client %d (%s) starts game [level %d from levedir %d (%s)]",
 332           player->number, player->player_name,
 333           (buffer[2] << 8) + buffer[3],
 334           (buffer[4] << 8) + buffer[5],
 335           &buffer[6]);
 336
 337   for (w=first_player; w; w=w->next)
 338     if (w->introduced)
 339       w->active = 1;
 340
 341   /* reset frame counter */
 342   ServerFrameCounter = 0;
 343
 344   /* reset player actions */
 345   for (v=first_player; v; v=v->next)
 346   {
 347     v->action = 0;
 348     v->action_received = FALSE;
 349   }
 350
 351   broadcast(NULL, 10 + strlen(&buffer[10])+1, 0);
 352 }
 353
 354 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 355 {
 356   if (options.verbose)
 357     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 358           player->number, player->player_name);
 359   broadcast(NULL, 2, 0);
 360 }
 361
 362 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 363 {
 364   if (options.verbose)
 365     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 366           player->number, player->player_name);
 367   broadcast(NULL, 2, 0);
 368 }
 369
 370 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 371 {
 372   if (options.verbose)
 373     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game",
 374           player->number, player->player_name);
 375   broadcast(NULL, 2, 0);
 376 }
 377
 378 static void Handle_OP_MOVE_FIGURE(struct NetworkServerPlayerInfo *player)
 379 {
 380   struct NetworkServerPlayerInfo *v;
 381   int last_client_nr = 0;
 382   int i;
 383
 384   /* store player action */
 385   for (v=first_player; v; v=v->next)
 386   {
 387     if (v->number == player->number)
 388     {
 389       v->action = buffer[2];
 390       v->action_received = TRUE;
 391     }
 392   }
 393
 394   /* check if server received action from each player */
 395   for (v=first_player; v; v=v->next)
 396   {
 397     if (!v->action_received)
 398       return;
 399
 400     if (v->number > last_client_nr)
 401       last_client_nr = v->number;
 402   }
 403
 404   /* initialize all player actions to zero */
 405   for (i=0; i<last_client_nr; i++)
 406     buffer[6 + i] = 0;
 407
 408   /* broadcast actions of all players to all players */
 409   for (v=first_player; v; v=v->next)
 410   {
 411     buffer[6 + v->number-1] = v->action;
 412     v->action = 0;
 413     v->action_received = FALSE;
 414   }
 415
 416   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 417   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 418   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 419   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 420
 421   broadcast(NULL, 6 + last_client_nr, 0);
 422
 423   ServerFrameCounter++;
 424 }
 425
 426 void NetworkServer(int port, int serveronly)
 427 {
 428   int i, sl, on;
 429   struct NetworkServerPlayerInfo *player;
 430   int mfd;
 431   int r;
 432   unsigned int len;
 433   struct protoent *tcpproto;
 434   struct timeval tv;
 435   int is_daemon = 0;
 436
 437 #ifndef NeXT
 438   struct sigaction sact;
 439 #endif
 440
 441   if (port == 0)
 442     port = DEFAULT_SERVER_PORT;
 443
 444   if (!serveronly)
 445     onceonly = 1;
 446
 447   if ((tcpproto = getprotobyname("tcp")) != NULL)
 448     tcp = tcpproto->p_proto;
 449
 450 #ifdef NeXT
 451   signal(SIGPIPE, SIG_IGN);
 452 #else
 453   sact.sa_handler = SIG_IGN;
 454   sigemptyset(&sact.sa_mask);
 455   sact.sa_flags = 0;
 456   sigaction(SIGPIPE, &sact, NULL);
 457 #endif
 458
 459
 460   if ((lfd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
 461     Error(ERR_EXIT_NETWORK_SERVER, "socket() failed");
 462
 463   saddr.sin_family = AF_INET;
 464   saddr.sin_addr.s_addr = htonl(INADDR_ANY);
 465   saddr.sin_port = htons(port);
 466
 467   on = 1;
 468
 469   setsockopt(lfd, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(int));
 470   if (bind(lfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0)
 471     Error(ERR_EXIT_NETWORK_SERVER, "bind() failed");
 472
 473   listen(lfd, 5);
 474
 475   if (is_daemon)
 476   {
 477     /* become a daemon, breaking all ties with the controlling terminal */
 478     options.verbose = 0;
 479     for (i=0; i<255; i++)
 480     {
 481       if (i != lfd)
 482         close(i);
 483     }
 484
 485     if (fork())
 486       exit(0);
 487     setsid();
 488     if (fork())
 489       exit(0);
 490     chdir("/");
 491
 492     /* open a fake stdin, stdout, stderr, just in case */
 493     open("/dev/null", O_RDONLY);
 494     open("/dev/null", O_WRONLY);
 495     open("/dev/null", O_WRONLY);
 496   }
 497
 498   if (options.verbose)
 499   {
 500     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 501     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 502           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 503   }
 504
 505   while(1)
 506   {
 507     interrupt = 0;
 508
 509     for (player=first_player; player; player=player->next)
 510       flushuser(player);
 511
 512     FD_ZERO(&fds);
 513     mfd = lfd;
 514     player = first_player;
 515     while (player)
 516     {
 517       FD_SET(player->fd, &fds);
 518       if (player->fd > mfd)
 519         mfd = player->fd;
 520       player = player->next;
 521     }
 522     FD_SET(lfd, &fds);
 523     tv.tv_sec = 0;
 524     tv.tv_usec = 500000;
 525     if ((sl = select(mfd + 1, &fds, NULL, NULL, &tv)) < 0)
 526     {
 527       if (errno != EINTR)
 528         Error(ERR_EXIT_NETWORK_SERVER, "select() failed");
 529       else
 530         continue;
 531     }
 532
 533     if (sl < 0)
 534       continue;
 535
 536     if (sl == 0)
 537       continue;
 538
 539     if (FD_ISSET(lfd, &fds))
 540     {
 541       int newfd, slen;
 542
 543       slen = sizeof(saddr);
 544       newfd = accept(lfd, (struct sockaddr *)&saddr, &slen);
 545       if (newfd < 0)
 546       {
 547         if (errno != EINTR)
 548           Error(ERR_EXIT_NETWORK_SERVER, "accept() failed");
 549       }
 550       else
 551       {
 552         if (tcp != -1)
 553         {
 554           on = 1;
 555           setsockopt(newfd, tcp, TCP_NODELAY, (char *)&on, sizeof(int));
 556         }
 557         AddPlayer(newfd);
 558       }
 559       continue;
 560     }
 561
 562     player = first_player;
 563
 564     do
 565     {
 566       if (FD_ISSET(player->fd, &fds))
 567       {
 568         r = read(player->fd, player->readbuffer + player->nread, MAX_BUFFER_SIZE - player->nread);
 569         if (r <= 0)
 570         {
 571           if (options.verbose)
 572             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 573                   player->number, player->player_name);
 574           RemovePlayer(player);
 575           interrupt = 1;
 576           break;
 577         }
 578         player->nread += r;
 579         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 580         {
 581           len = player->readbuffer[3];
 582           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 583           {
 584             if (options.verbose)
 585               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 586                     player->number, player->player_name);
 587             RemovePlayer(player);
 588             interrupt = 1;
 589             break;
 590           }
 591           memcpy(buffer, &player->readbuffer[4], len);
 592           player->nread -= 4 + len;
 593           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 594
 595           buffer[0] = player->number;
 596           if (!player->introduced && buffer[1] != OP_PLAYER_NAME)
 597           {
 598             if (options.verbose)
 599               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME)", buffer[0], buffer[1]);
 600
 601             RemovePlayer(player);
 602             interrupt = 1;
 603             break;
 604           }
 605
 606           switch(buffer[1])
 607           {
 608             case OP_PLAYER_NAME:
 609               Handle_OP_PLAYER_NAME(player, len);
 610               break;
 611
 612             case OP_PROTOCOL_VERSION:
 613               Handle_OP_PROTOCOL_VERSION(player, len);
 614               break;
 615
 616             case OP_NUMBER_WANTED:
 617               Handle_OP_NUMBER_WANTED(player);
 618               break;
 619
 620             case OP_START_PLAYING:
 621               Handle_OP_START_PLAYING(player);
 622               break;
 623
 624             case OP_PAUSE_PLAYING:
 625               Handle_OP_PAUSE_PLAYING(player);
 626               break;
 627
 628             case OP_CONTINUE_PLAYING:
 629               Handle_OP_CONTINUE_PLAYING(player);
 630               break;
 631
 632             case OP_STOP_PLAYING:
 633               Handle_OP_STOP_PLAYING(player);
 634               break;
 635
 636             case OP_MOVE_FIGURE:
 637               Handle_OP_MOVE_FIGURE(player);
 638               break;
 639
 640             case OP_BROADCAST_MESSAGE:
 641               buffer[len] = '\0';
 642               if (options.verbose)
 643                 Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
 644                       player->number, player->player_name, &buffer[2]);
 645               broadcast(player, len, 0);
 646               break;
 647
 648             default:
 649               if (options.verbose)
 650                 Error(ERR_NETWORK_SERVER,
 651                       "unknown opcode %d from client %d (%s)",
 652                       buffer[0], player->number, player->player_name);
 653           }
 654         }
 655       }
 656
 657       if (player && !interrupt)
 658         player = player->next;
 659     }
 660     while (player && !interrupt);
 661   }
 662 }
 663
 664 #endif /* !MSDOS */