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 "libgame/platform.h"
  13
  14 #if defined(NETWORK_AVALIABLE)
  15
  16 #include <fcntl.h>
  17 #include <sys/time.h>
  18 #include <signal.h>
  19 #include <errno.h>
  20
  21 #include "main.h"
  22
  23 #include "libgame/libgame.h"
  24
  25 #include "netserv.h"
  26
  27 static int clients = 0;
  28 static int onceonly = 0;
  29
  30 struct NetworkServerPlayerInfo
  31 {
  32   TCPsocket fd;
  33   char player_name[16];
  34   unsigned char number;
  35   struct NetworkServerPlayerInfo *next;
  36   char active;
  37   char introduced;
  38   unsigned char readbuffer[MAX_BUFFER_SIZE];
  39   unsigned char writbuffer[MAX_BUFFER_SIZE];
  40   int nread, nwrite;
  41   byte action;
  42   boolean action_received;
  43 };
  44
  45 static struct NetworkServerPlayerInfo *first_player = NULL;
  46
  47 #define NEXT(player) ((player)->next ? (player)->next : first_player)
  48
  49 /* TODO: peer address */
  50 static TCPsocket lfd;           /* listening socket */
  51 static SDLNet_SocketSet fds;    /* socket set */
  52
  53 static unsigned char realbuffer[512], *buffer = realbuffer + 4;
  54
  55 static int interrupt;
  56
  57 static unsigned int ServerFrameCounter = 0;
  58
  59 static void addtobuffer(struct NetworkServerPlayerInfo *player,
  60                         unsigned char *b, int len)
  61 {
  62   if (player->nwrite + len >= MAX_BUFFER_SIZE)
  63     Error(ERR_EXIT_NETWORK_SERVER,
  64           "internal error: network send buffer overflow");
  65
  66   memcpy(player->writbuffer + player->nwrite, b, len);
  67   player->nwrite += len;
  68 }
  69
  70 static void flushuser(struct NetworkServerPlayerInfo *player)
  71 {
  72   if (player->nwrite)
  73   {
  74     SDLNet_TCP_Send(player->fd, player->writbuffer, player->nwrite);
  75
  76     player->nwrite = 0;
  77   }
  78 }
  79
  80 static void broadcast(struct NetworkServerPlayerInfo *except,
  81                       int len, int activeonly)
  82 {
  83   struct NetworkServerPlayerInfo *player;
  84
  85   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  86   realbuffer[3] = (unsigned char)len;
  87   for (player = first_player; player; player = player->next)
  88     if (player != except && player->introduced &&
  89         (player->active || !activeonly))
  90       addtobuffer(player, realbuffer, 4 + len);
  91 }
  92
  93 static void sendtoone(struct NetworkServerPlayerInfo *to, int len)
  94 {
  95   realbuffer[0] = realbuffer[1] = realbuffer[2] = 0;
  96   realbuffer[3] = (unsigned char)len;
  97   addtobuffer(to, realbuffer, 4 + len);
  98 }
  99
 100 static void RemovePlayer(struct NetworkServerPlayerInfo *player)
 101 {
 102   struct NetworkServerPlayerInfo *v;
 103
 104   if (options.verbose)
 105     Error(ERR_NETWORK_SERVER, "dropping client %d (%s)",
 106           player->number, player->player_name);
 107
 108   if (player == first_player)
 109     first_player = player->next;
 110   else
 111   {
 112     for (v = first_player; v; v = v->next)
 113     {
 114       if (v->next && v->next == player)
 115       {
 116         v->next = player->next;
 117         break;
 118       }
 119     }
 120   }
 121
 122   SDLNet_TCP_DelSocket(fds, player->fd);
 123   SDLNet_TCP_Close(player->fd);
 124
 125   if (player->introduced)
 126   {
 127     buffer[0] = player->number;
 128     buffer[1] = OP_PLAYER_DISCONNECTED;
 129     broadcast(player, 2, 0);
 130   }
 131
 132   free(player);
 133   clients--;
 134
 135   if (onceonly && clients == 0)
 136   {
 137     if (options.verbose)
 138     {
 139       Error(ERR_NETWORK_SERVER, "no clients left");
 140       Error(ERR_NETWORK_SERVER, "aborting");
 141     }
 142     exit(0);
 143   }
 144 }
 145
 146 static void AddPlayer(TCPsocket fd)
 147 {
 148   struct NetworkServerPlayerInfo *player, *v;
 149   unsigned char nxn;
 150   boolean again = TRUE;
 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   SDLNet_TCP_AddSocket(fds, fd);
 165
 166   first_player = player;
 167
 168   nxn = 1;
 169
 170   while (again)
 171   {
 172     again = FALSE;
 173     v = player->next;
 174
 175     while (v)
 176     {
 177       if (v->number == nxn)
 178       {
 179         nxn++;
 180
 181         again = TRUE;
 182         break;
 183       }
 184       v = v->next;
 185     }
 186   }
 187
 188   player->number = nxn;
 189   clients++;
 190
 191   buffer[0] = 0;
 192   buffer[1] = OP_YOUR_NUMBER;
 193   buffer[2] = player->number;
 194   sendtoone(player, 3);
 195 }
 196
 197 static void Handle_OP_PROTOCOL_VERSION(struct NetworkServerPlayerInfo *player,
 198                                        unsigned int len)
 199 {
 200   if (len != 5 ||
 201       buffer[2] != PROTOCOL_VERSION_1 ||
 202       buffer[3] != PROTOCOL_VERSION_2)
 203   {
 204     if (options.verbose)
 205       Error(ERR_NETWORK_SERVER,
 206             "client %d (%s) has wrong protocol version %d.%d.%d",
 207             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 208
 209     buffer[0] = 0;
 210     buffer[1] = OP_BAD_PROTOCOL_VERSION;
 211     buffer[2] = PROTOCOL_VERSION_1;
 212     buffer[3] = PROTOCOL_VERSION_2;
 213     buffer[4] = PROTOCOL_VERSION_3;
 214     sendtoone(player, 5);
 215     flushuser(player);
 216
 217     RemovePlayer(player);
 218     interrupt = 1;
 219   }
 220   else
 221   {
 222     if (options.verbose)
 223       Error(ERR_NETWORK_SERVER,
 224             "client %d (%s) uses protocol version %d.%d.%d",
 225             player->number, player->player_name, buffer[2], buffer[3], buffer[4]);
 226   }
 227 }
 228
 229 static void Handle_OP_NUMBER_WANTED(struct NetworkServerPlayerInfo *player)
 230 {
 231   struct NetworkServerPlayerInfo *v;
 232   int client_nr = player->number;
 233   int nr_wanted = buffer[2];
 234   int nr_is_free = 1;
 235
 236   if (options.verbose)
 237       Error(ERR_NETWORK_SERVER, "client %d (%s) wants to switch to # %d",
 238             player->number, player->player_name, nr_wanted);
 239
 240   for (v = first_player; v; v = v->next)
 241   {
 242     if (v->number == nr_wanted)
 243     {
 244       nr_is_free = 0;
 245       break;
 246     }
 247   }
 248
 249   if (options.verbose)
 250   {
 251     if (nr_is_free)
 252       Error(ERR_NETWORK_SERVER, "client %d (%s) switches to # %d",
 253             player->number, player->player_name, nr_wanted);
 254     else if (player->number == nr_wanted)
 255       Error(ERR_NETWORK_SERVER, "client %d (%s) already has # %d",
 256             player->number, player->player_name, nr_wanted);
 257     else
 258       Error(ERR_NETWORK_SERVER,
 259             "client %d (%s) cannot switch (client %d already exists)",
 260             player->number, player->player_name, nr_wanted);
 261   }
 262
 263   if (nr_is_free)
 264     player->number = nr_wanted;
 265
 266   buffer[0] = client_nr;
 267   buffer[1] = OP_NUMBER_WANTED;
 268   buffer[2] = nr_wanted;
 269   buffer[3] = player->number;
 270
 271   /*
 272   sendtoone(player, 4);
 273   */
 274
 275   broadcast(NULL, 4, 0);
 276 }
 277
 278 static void Handle_OP_PLAYER_NAME(struct NetworkServerPlayerInfo *player,
 279                                   unsigned int len)
 280 {
 281   struct NetworkServerPlayerInfo *v;
 282   int i;
 283
 284   if (len>16)
 285     len=16;
 286   memcpy(player->player_name, &buffer[2], len-2);
 287   player->player_name[len-2] = 0;
 288   for (i = 0; i < len - 2; i++)
 289   {
 290     if (player->player_name[i] < ' ' ||
 291         ((unsigned char)(player->player_name[i]) > 0x7e &&
 292          (unsigned char)(player->player_name[i]) <= 0xa0))
 293     {
 294       player->player_name[i] = 0;
 295       break;
 296     }
 297   }
 298
 299   if (!player->introduced)
 300   {
 301     buffer[0] = player->number;
 302     buffer[1] = OP_PLAYER_CONNECTED;
 303     broadcast(player, 2, 0);
 304   }
 305
 306   if (options.verbose)
 307     Error(ERR_NETWORK_SERVER, "client %d calls itself \"%s\"",
 308           player->number, player->player_name);
 309   buffer[1] = OP_PLAYER_NAME;
 310   broadcast(player, len, 0);
 311
 312   if (!player->introduced)
 313   {
 314     for (v = first_player; v; v = v->next)
 315     {
 316       if (v != player && v->introduced)
 317       {
 318         buffer[0] = v->number;
 319         buffer[1] = OP_PLAYER_CONNECTED;
 320         sendtoone(player, 2);
 321         buffer[1] = OP_PLAYER_NAME;
 322         memcpy(&buffer[2], v->player_name, 14);
 323         sendtoone(player, 2+strlen(v->player_name));
 324       }
 325     }
 326   }
 327
 328   player->introduced = 1;
 329 }
 330
 331 static void Handle_OP_START_PLAYING(struct NetworkServerPlayerInfo *player)
 332 {
 333   struct NetworkServerPlayerInfo *v, *w;
 334
 335   if (options.verbose)
 336     Error(ERR_NETWORK_SERVER,
 337           "client %d (%s) starts game [level %d from leveldir %d (%s)]",
 338           player->number, player->player_name,
 339           (buffer[2] << 8) + buffer[3],
 340           (buffer[4] << 8) + buffer[5],
 341           &buffer[10]);
 342
 343   for (w = first_player; w; w = w->next)
 344     if (w->introduced)
 345       w->active = 1;
 346
 347   /* reset frame counter */
 348   ServerFrameCounter = 0;
 349
 350   Error(ERR_NETWORK_SERVER, "resetting ServerFrameCounter to 0");
 351
 352   /* reset player actions */
 353   for (v = first_player; v; v = v->next)
 354   {
 355     v->action = 0;
 356     v->action_received = FALSE;
 357   }
 358
 359   broadcast(NULL, 10 + strlen((char *)&buffer[10])+1, 0);
 360 }
 361
 362 static void Handle_OP_PAUSE_PLAYING(struct NetworkServerPlayerInfo *player)
 363 {
 364   if (options.verbose)
 365     Error(ERR_NETWORK_SERVER, "client %d (%s) pauses game",
 366           player->number, player->player_name);
 367   broadcast(NULL, 2, 0);
 368 }
 369
 370 static void Handle_OP_CONTINUE_PLAYING(struct NetworkServerPlayerInfo *player)
 371 {
 372   if (options.verbose)
 373     Error(ERR_NETWORK_SERVER, "client %d (%s) continues game",
 374           player->number, player->player_name);
 375   broadcast(NULL, 2, 0);
 376 }
 377
 378 static void Handle_OP_STOP_PLAYING(struct NetworkServerPlayerInfo *player)
 379 {
 380   int cause_for_stopping = buffer[2];
 381
 382   if (options.verbose)
 383     Error(ERR_NETWORK_SERVER, "client %d (%s) stops game [%d]",
 384           player->number, player->player_name, cause_for_stopping);
 385   broadcast(NULL, 3, 0);
 386 }
 387
 388 static void Handle_OP_MOVE_PLAYER(struct NetworkServerPlayerInfo *player)
 389 {
 390   struct NetworkServerPlayerInfo *v;
 391   int last_client_nr = 0;
 392   int i;
 393
 394   /* store player action */
 395   for (v = first_player; v; v = v->next)
 396   {
 397     if (v->number == player->number)
 398     {
 399       v->action = buffer[2];
 400       v->action_received = TRUE;
 401     }
 402   }
 403
 404   /* check if server received action from each player */
 405   for (v = first_player; v; v = v->next)
 406   {
 407     if (!v->action_received)
 408       return;
 409
 410     if (v->number > last_client_nr)
 411       last_client_nr = v->number;
 412   }
 413
 414   /* initialize all player actions to zero */
 415   for (i = 0; i < last_client_nr; i++)
 416     buffer[6 + i] = 0;
 417
 418   /* broadcast actions of all players to all players */
 419   for (v = first_player; v; v = v->next)
 420   {
 421     buffer[6 + v->number-1] = v->action;
 422     v->action = 0;
 423     v->action_received = FALSE;
 424   }
 425
 426   buffer[2] = (unsigned char)((ServerFrameCounter >> 24) & 0xff);
 427   buffer[3] = (unsigned char)((ServerFrameCounter >> 16) & 0xff);
 428   buffer[4] = (unsigned char)((ServerFrameCounter >>  8) & 0xff);
 429   buffer[5] = (unsigned char)((ServerFrameCounter >>  0) & 0xff);
 430
 431   broadcast(NULL, 6 + last_client_nr, 0);
 432
 433   ServerFrameCounter++;
 434 }
 435
 436 /* the following is not used for a standalone server;
 437    the pointer points to an integer containing the port-number */
 438 int NetworkServerThread(void *ptr)
 439 {
 440   NetworkServer(*((int *) ptr), 0);
 441
 442   /* should never be reached */
 443   return 0;
 444 }
 445
 446 void NetworkServer(int port, int serveronly)
 447 {
 448   int sl;
 449   struct NetworkServerPlayerInfo *player;
 450   int r;
 451   unsigned int len;
 452   IPaddress ip;
 453
 454 #if defined(PLATFORM_UNIX) && !defined(PLATFORM_NEXT)
 455   struct sigaction sact;
 456 #endif
 457
 458   if (port == 0)
 459     port = DEFAULT_SERVER_PORT;
 460
 461   if (!serveronly)
 462     onceonly = 1;
 463
 464 #if defined(PLATFORM_UNIX)
 465 #if defined(PLATFORM_NEXT)
 466   signal(SIGPIPE, SIG_IGN);
 467 #else
 468   sact.sa_handler = SIG_IGN;
 469   sigemptyset(&sact.sa_mask);
 470   sact.sa_flags = 0;
 471   sigaction(SIGPIPE, &sact, NULL);
 472 #endif
 473 #endif
 474
 475   if (SDLNet_ResolveHost(&ip, NULL, port) == -1)
 476     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_ResolveHost() failed");
 477
 478   lfd = SDLNet_TCP_Open(&ip);
 479   if (!lfd)
 480     Error(ERR_EXIT_NETWORK_SERVER, "SDLNet_TCP_Open() failed");
 481
 482   fds = SDLNet_AllocSocketSet(MAX_PLAYERS+1);
 483   SDLNet_TCP_AddSocket(fds, lfd);
 484
 485   if (options.verbose)
 486   {
 487     Error(ERR_NETWORK_SERVER, "started up, listening on port %d", port);
 488     Error(ERR_NETWORK_SERVER, "using protocol version %d.%d.%d",
 489           PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, PROTOCOL_VERSION_3);
 490   }
 491
 492   while (1)
 493   {
 494     interrupt = 0;
 495
 496     for (player = first_player; player; player = player->next)
 497       flushuser(player);
 498
 499     if ((sl = SDLNet_CheckSockets(fds, 500000)) < 1)
 500     {
 501       Error(ERR_NETWORK_SERVER, "SDLNet_CheckSockets failed: %s",
 502             SDLNet_GetError());
 503       perror("SDLNet_CheckSockets");
 504     }
 505
 506     if (sl < 0)
 507       continue;
 508
 509     if (sl == 0)
 510       continue;
 511
 512     /* accept incoming connections */
 513     if (SDLNet_SocketReady(lfd))
 514     {
 515       TCPsocket newsock;
 516
 517       newsock = SDLNet_TCP_Accept(lfd);
 518
 519       if (newsock)
 520         AddPlayer(newsock);
 521     }
 522
 523     player = first_player;
 524
 525     do
 526     {
 527       if (SDLNet_SocketReady(player->fd))
 528       {
 529         /* read only 1 byte, because SDLNet blocks when we want more than is
 530            in the buffer */
 531         r = SDLNet_TCP_Recv(player->fd, player->readbuffer + player->nread, 1);
 532
 533         if (r <= 0)
 534         {
 535           if (options.verbose)
 536             Error(ERR_NETWORK_SERVER, "EOF from client %d (%s)",
 537                   player->number, player->player_name);
 538           RemovePlayer(player);
 539           interrupt = 1;
 540           break;
 541         }
 542         player->nread += r;
 543         while (player->nread >= 4 && player->nread >= 4 + player->readbuffer[3])
 544         {
 545           len = player->readbuffer[3];
 546           if (player->readbuffer[0] || player->readbuffer[1] || player->readbuffer[2])
 547           {
 548             if (options.verbose)
 549               Error(ERR_NETWORK_SERVER, "crap from client %d (%s)",
 550                     player->number, player->player_name);
 551             RemovePlayer(player);
 552             interrupt = 1;
 553             break;
 554           }
 555           memcpy(buffer, &player->readbuffer[4], len);
 556           player->nread -= 4 + len;
 557           memmove(player->readbuffer, player->readbuffer + 4 + len, player->nread);
 558
 559           buffer[0] = player->number;
 560           if (!player->introduced && buffer[1] != OP_PLAYER_NAME)
 561           {
 562             if (options.verbose)
 563               Error(ERR_NETWORK_SERVER, "!(client %d)->introduced && buffer[1]==%d (expected OP_PLAYER_NAME)", buffer[0], buffer[1]);
 564
 565             RemovePlayer(player);
 566             interrupt = 1;
 567             break;
 568           }
 569
 570           switch (buffer[1])
 571           {
 572             case OP_PLAYER_NAME:
 573               Handle_OP_PLAYER_NAME(player, len);
 574               break;
 575
 576             case OP_PROTOCOL_VERSION:
 577               Handle_OP_PROTOCOL_VERSION(player, len);
 578               break;
 579
 580             case OP_NUMBER_WANTED:
 581               Handle_OP_NUMBER_WANTED(player);
 582               break;
 583
 584             case OP_START_PLAYING:
 585               Handle_OP_START_PLAYING(player);
 586               break;
 587
 588             case OP_PAUSE_PLAYING:
 589               Handle_OP_PAUSE_PLAYING(player);
 590               break;
 591
 592             case OP_CONTINUE_PLAYING:
 593               Handle_OP_CONTINUE_PLAYING(player);
 594               break;
 595
 596             case OP_STOP_PLAYING:
 597               Handle_OP_STOP_PLAYING(player);
 598               break;
 599
 600             case OP_MOVE_PLAYER:
 601               Handle_OP_MOVE_PLAYER(player);
 602               break;
 603
 604             case OP_BROADCAST_MESSAGE:
 605               buffer[len] = '\0';
 606               if (options.verbose)
 607                 Error(ERR_NETWORK_SERVER, "client %d (%s) sends message: %s",
 608                       player->number, player->player_name, &buffer[2]);
 609               broadcast(player, len, 0);
 610               break;
 611
 612             default:
 613               if (options.verbose)
 614                 Error(ERR_NETWORK_SERVER,
 615                       "unknown opcode %d from client %d (%s)",
 616                       buffer[0], player->number, player->player_name);
 617           }
 618         }
 619       }
 620
 621       if (player && !interrupt)
 622         player = player->next;
 623     }
 624     while (player && !interrupt);
 625   }
 626 }
 627
 628 #endif /* NETWORK_AVALIABLE */