Modules/IPStack/tcp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - TCP Handling
   4  */
   5 #include "ipstack.h"
   6 #include "ipv4.h"
   7 #include "tcp.h"
   8
   9 #define TCP_MIN_DYNPORT 0xC000
  10 #define TCP_MAX_HALFOPEN        1024    // Should be enough
  11
  12 // === PROTOTYPES ===
  13 void    TCP_Initialise();
  14 void    TCP_StartConnection(tTCPConnection *Conn);
  15 void    TCP_SendPacket(tTCPConnection *Conn, size_t Length, tTCPHeader *Data);
  16 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  17 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  18 void    TCP_INT_AppendRecieved(tTCPConnection *Connection, tTCPStoredPacket *Ptk);
  19 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  20 Uint16  TCP_GetUnusedPort();
  21  int    TCP_AllocatePort(Uint16 Port);
  22  int    TCP_DeallocatePort(Uint16 Port);
  23 // --- Server
  24 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  25 char    *TCP_Server_ReadDir(tVFS_Node *Node, int Pos);
  26 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, char *Name);
  27  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  28 void    TCP_Server_Close(tVFS_Node *Node);
  29 // --- Client
  30 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  31 Uint64  TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  32 Uint64  TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  33  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  34 void    TCP_Client_Close(tVFS_Node *Node);
  35
  36 // === TEMPLATES ===
  37 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  38 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  39
  40 // === GLOBALS ===
  41  int    giTCP_NumHalfopen = 0;
  42 tSpinlock       glTCP_Listeners;
  43 tTCPListener    *gTCP_Listeners;
  44 tSpinlock       glTCP_OutbountCons;
  45 tTCPConnection  *gTCP_OutbountCons;
  46 Uint32  gaTCP_PortBitmap[0x800];
  47  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  48
  49 // === CODE ===
  50 /**
  51  * \brief Initialise the TCP Layer
  52  *
  53  * Registers the client and server files and the GetPacket callback
  54  */
  55 void TCP_Initialise()
  56 {
  57         IPStack_AddFile(&gTCP_ServerFile);
  58         IPStack_AddFile(&gTCP_ClientFile);
  59         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  60 }
  61
  62 /**
  63  * \brief Open a connection to another host using TCP
  64  * \param Conn  Connection structure
  65  */
  66 void TCP_StartConnection(tTCPConnection *Conn)
  67 {
  68         tTCPHeader      hdr;
  69
  70         hdr.SourcePort = Conn->LocalPort;
  71         hdr.DestPort = Conn->RemotePort;
  72         Conn->NextSequenceSend = rand();
  73         hdr.SequenceNumber = Conn->NextSequenceSend;
  74         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
  75         hdr.Flags = TCP_FLAG_SYN;
  76         hdr.WindowSize = 0;     // TODO
  77         hdr.Checksum = 0;       // TODO
  78         hdr.UrgentPointer = 0;
  79
  80         TCP_SendPacket( Conn, sizeof(tTCPHeader), &hdr );
  81         return ;
  82 }
  83
  84 /**
  85  * \brief Sends a packet from the specified connection, calculating the checksums
  86  * \param Conn  Connection
  87  * \param Length        Length of data
  88  * \param Data  Packet data (cast as a TCP Header)
  89  */
  90 void TCP_SendPacket( tTCPConnection *Conn, size_t Length, tTCPHeader *Data )
  91 {
  92         size_t  buflen;
  93         Uint32  *buf;
  94         switch( Conn->Interface->Type )
  95         {
  96         case 4: // Append IPv4 Pseudo Header
  97                 buflen = 4 + 4 + 4 + ((Length+1)&~1);
  98                 buf = malloc( buflen );
  99                 buf[0] = Conn->Interface->IP4.Address.L;
 100                 buf[1] = Conn->RemoteIP.v4.L;
 101                 buf[2] = (htons(Length)<<16) | (6<<8) | 0;
 102                 Data->Checksum = 0;
 103                 memcpy( &buf[3], Data, Length );
 104                 Data->Checksum = IPv4_Checksum( buf, buflen );
 105                 free(buf);
 106                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, Length, Data);
 107                 break;
 108         }
 109 }
 110
 111 /**
 112  * \brief Handles a packet from the IP Layer
 113  * \param Interface     Interface the packet arrived from
 114  * \param Address       Pointer to the addres structure
 115  * \param Length        Size of packet in bytes
 116  * \param Buffer        Packet data
 117  */
 118 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 119 {
 120         tTCPHeader      *hdr = Buffer;
 121         tTCPListener    *srv;
 122         tTCPConnection  *conn;
 123
 124         Log("[TCP  ] SourcePort = %i, DestPort = %i",
 125                 ntohs(hdr->SourcePort), ntohs(hdr->DestPort));
 126         Log("[TCP  ] SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 127         Log("[TCP  ] AcknowlegementNumber = 0x%x", ntohl(hdr->AcknowlegementNumber));
 128         Log("[TCP  ] DataOffset = %i", hdr->DataOffset >> 4);
 129         Log("[TCP  ] Flags = {");
 130         Log("[TCP  ]   CWR = %B, ECE = %B",
 131                 !!(hdr->Flags & TCP_FLAG_CWR), !!(hdr->Flags & TCP_FLAG_ECE));
 132         Log("[TCP  ]   URG = %B, ACK = %B",
 133                 !!(hdr->Flags & TCP_FLAG_URG), !!(hdr->Flags & TCP_FLAG_ACK));
 134         Log("[TCP  ]   PSH = %B, RST = %B",
 135                 !!(hdr->Flags & TCP_FLAG_PSH), !!(hdr->Flags & TCP_FLAG_RST));
 136         Log("[TCP  ]   SYN = %B, FIN = %B",
 137                 !!(hdr->Flags & TCP_FLAG_SYN), !!(hdr->Flags & TCP_FLAG_FIN));
 138         Log("[TCP  ] }");
 139         Log("[TCP  ] WindowSize = %i", htons(hdr->WindowSize));
 140         Log("[TCP  ] Checksum = 0x%x", htons(hdr->Checksum));
 141         Log("[TCP  ] UrgentPointer = 0x%x", htons(hdr->UrgentPointer));
 142
 143         if( Length > (hdr->DataOffset >> 4)*4 )
 144         {
 145                 Debug_HexDump(
 146                         "[TCP  ] Packet Data = ",
 147                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 148                         Length - (hdr->DataOffset >> 4)*4
 149                         );
 150         }
 151
 152         // Check Servers
 153         {
 154                 for( srv = gTCP_Listeners; srv; srv = srv->Next )
 155                 {
 156                         // Check if the server is active
 157                         if(srv->Port == 0)      continue;
 158                         // Check the interface
 159                         if(srv->Interface && srv->Interface != Interface)       continue;
 160                         // Check the destination port
 161                         if(srv->Port != htons(hdr->DestPort))   continue;
 162
 163                         Log("[TCP  ] Matches server %p", srv);
 164                         // Is this in an established connection?
 165                         for( conn = srv->Connections; conn; conn = conn->Next )
 166                         {
 167                                 Log("[TCP  ] conn->Interface(%p) == Interface(%p)",
 168                                         conn->Interface, Interface);
 169                                 // Check that it is coming in on the same interface
 170                                 if(conn->Interface != Interface)        continue;
 171
 172                                 // Check Source Port
 173                                 Log("[TCP  ] conn->RemotePort(%i) == hdr->SourcePort(%i)",
 174                                         conn->RemotePort, ntohs(hdr->SourcePort));
 175                                 if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 176
 177                                 // Check Source IP
 178                                 if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 179                                         continue;
 180                                 if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 181                                         continue;
 182
 183                                 Log("[TCP  ] Matches connection %p", conn);
 184                                 // We have a response!
 185                                 TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 186
 187                                 return;
 188                         }
 189
 190                         Log("[TCP  ] Opening Connection");
 191                         // Open a new connection (well, check that it's a SYN)
 192                         if(hdr->Flags != TCP_FLAG_SYN) {
 193                                 Log("[TCP  ] Packet is not a SYN");
 194                                 return ;
 195                         }
 196
 197                         // TODO: Check for halfopen max
 198
 199                         conn = calloc(1, sizeof(tTCPConnection));
 200                         conn->State = TCP_ST_HALFOPEN;
 201                         conn->LocalPort = srv->Port;
 202                         conn->RemotePort = ntohs(hdr->SourcePort);
 203                         conn->Interface = Interface;
 204
 205                         switch(Interface->Type)
 206                         {
 207                         case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 208                         case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 209                         }
 210
 211                         conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 212                         conn->NextSequenceSend = rand();
 213
 214                         // Create node
 215                         conn->Node.NumACLs = 1;
 216                         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 217                         conn->Node.ImplInt = srv->NextID ++;
 218                         conn->Node.Read = TCP_Client_Read;
 219                         conn->Node.Write = TCP_Client_Write;
 220                         //conn->Node.Close = TCP_SrvConn_Close;
 221
 222                         // Hmm... Theoretically, this lock will never have to wait,
 223                         // as the interface is locked to the watching thread, and this
 224                         // runs in the watching thread. But, it's a good idea to have
 225                         // it, just in case
 226                         // Oh, wait, there is a case where a wildcard can be used
 227                         // (srv->Interface == NULL) so having the lock is a good idea
 228                         LOCK(&srv->lConnections);
 229                         if( !srv->Connections )
 230                                 srv->Connections = conn;
 231                         else
 232                                 srv->ConnectionsTail->Next = conn;
 233                         srv->ConnectionsTail = conn;
 234                         if(!srv->NewConnections)
 235                                 srv->NewConnections = conn;
 236                         RELEASE(&srv->lConnections);
 237
 238                         // Send the SYN ACK
 239                         hdr->Flags |= TCP_FLAG_ACK;
 240                         hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 241                         hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 242                         hdr->DestPort = hdr->SourcePort;
 243                         hdr->SourcePort = htons(srv->Port);
 244                         hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 245                         TCP_SendPacket( conn, sizeof(tTCPHeader), hdr );
 246
 247                         return ;
 248                 }
 249         }
 250
 251
 252         // Check Open Connections
 253         {
 254                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 255                 {
 256                         // Check that it is coming in on the same interface
 257                         if(conn->Interface != Interface)        continue;
 258
 259                         // Check Source Port
 260                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 261
 262                         // Check Source IP
 263                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 264                                 continue;
 265                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 266                                 continue;
 267
 268                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 269                         return ;
 270                 }
 271         }
 272
 273         Log("[TCP  ] No Match");
 274 }
 275
 276 /**
 277  * \brief Handles a packet sent to a specific connection
 278  * \param Connection    TCP Connection pointer
 279  * \param Header        TCP Packet pointer
 280  * \param Length        Length of the packet
 281  */
 282 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 283 {
 284         tTCPStoredPacket        *pkt;
 285          int    dataLen;
 286
 287         Connection->State = TCP_ST_OPEN;
 288         if(Header->Flags & TCP_FLAG_SYN) {
 289                 Connection->NextSequenceRcv = Header->SequenceNumber + 1;
 290         }
 291
 292         // Get length of data
 293         dataLen = Length - (Header->DataOffset>>4)*4;
 294         Log("[TCP  ] HandleConnectionPacket - dataLen = %i", dataLen);
 295
 296         if(Header->Flags & TCP_FLAG_ACK) {
 297                 // TODO: Process an ACKed Packet
 298                 Log("[TCP  ] Conn %p, Packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 299         }
 300
 301         if(dataLen == 0)        return ;
 302
 303         // NOTES:
 304         // Flags
 305         //    PSH - Has Data?
 306         // /NOTES
 307
 308         // Allocate and fill cached packet
 309         pkt = malloc( dataLen + sizeof(tTCPStoredPacket) );
 310         pkt->Next = NULL;
 311         pkt->Sequence = ntohl(Header->SequenceNumber);
 312         pkt->Length = dataLen;
 313         memcpy(pkt->Data, (Uint8*)Header + (Header->DataOffset>>4)*4, dataLen);
 314
 315         // Is this packet the next expected packet?
 316         if( pkt->Sequence != Connection->NextSequenceRcv )
 317         {
 318                 tTCPStoredPacket        *tmp, *prev = NULL;
 319
 320                 Log("[TCP  ] Out of sequence packet (0x%08x != 0x%08x)",
 321                         pkt->Sequence, Connection->NextSequenceRcv);
 322
 323                 // No? Well, let's cache it and look at it later
 324                 LOCK( &Connection->lFuturePackets );
 325                 for(tmp = Connection->FuturePackets;
 326                         tmp;
 327                         prev = tmp, tmp = tmp->Next)
 328                 {
 329                         if(tmp->Sequence > pkt->Sequence)       break;
 330                 }
 331                 if(prev)
 332                         prev->Next = pkt;
 333                 else
 334                         Connection->FuturePackets = pkt;
 335                 pkt->Next = tmp;
 336                 RELEASE( &Connection->lFuturePackets );
 337         }
 338         else
 339         {
 340                 // Ooh, Goodie! Add it to the recieved list
 341                 TCP_INT_AppendRecieved(Connection, pkt);
 342                 if(dataLen)
 343                         Connection->NextSequenceRcv += dataLen;
 344                 else
 345                         Connection->NextSequenceRcv += 1;
 346
 347                 // TODO: This should be moved out of the watcher thread,
 348                 // so that a single lost packet on one connection doesn't cause
 349                 // all connections on the interface to lag.
 350                 TCP_INT_UpdateRecievedFromFuture(Connection);
 351         }
 352
 353         // TODO: Check ACK code validity
 354         Header->AcknowlegementNumber = ntohl(pkt->Sequence) + dataLen;
 355         Header->SequenceNumber = ntohl(Connection->NextSequenceSend);
 356         Header->Flags &= TCP_FLAG_SYN;
 357         Header->Flags = TCP_FLAG_ACK;
 358         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 359 }
 360
 361 /**
 362  * \brief Appends a packet to the recieved list
 363  * \param Connection    Connection structure
 364  * \param Pkt   Packet structure on heap
 365  */
 366 void TCP_INT_AppendRecieved(tTCPConnection *Connection, tTCPStoredPacket *Pkt)
 367 {
 368         LOCK( &Connection->lRecievedPackets );
 369         if(Connection->RecievedPackets)
 370         {
 371                 Connection->RecievedPacketsTail->Next = Pkt;
 372                 Connection->RecievedPacketsTail = Pkt;
 373         }
 374         else
 375         {
 376                 Connection->RecievedPackets = Pkt;
 377                 Connection->RecievedPacketsTail = Pkt;
 378         }
 379         RELEASE( &Connection->lRecievedPackets );
 380 }
 381
 382 /**
 383  * \brief Updates the connections recieved list from the future list
 384  * \param Connection    Connection structure
 385  *
 386  * Updates the recieved packets list with packets from the future (out
 387  * of order) packets list that are now able to be added in direct
 388  * sequence.
 389  */
 390 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 391 {
 392         tTCPStoredPacket        *pkt, *prev;
 393         for(;;)
 394         {
 395                 prev = NULL;
 396                 // Look for the next expected packet in the cache.
 397                 LOCK( &Connection->lFuturePackets );
 398                 for(pkt = Connection->FuturePackets;
 399                         pkt && pkt->Sequence < Connection->NextSequenceRcv;
 400                         prev = pkt, pkt = pkt->Next);
 401
 402                 // If we can't find the expected next packet, stop looking
 403                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 404                         RELEASE( &Connection->lFuturePackets );
 405                         return;
 406                 }
 407
 408                 // Delete packet from future list
 409                 if(prev)
 410                         prev->Next = pkt->Next;
 411                 else
 412                         Connection->FuturePackets = pkt->Next;
 413
 414                 // Release list
 415                 RELEASE( &Connection->lFuturePackets );
 416
 417                 // Looks like we found one
 418                 TCP_INT_AppendRecieved(Connection, pkt);
 419                 Connection->NextSequenceRcv ++;
 420         }
 421 }
 422
 423 /**
 424  * \fn Uint16 TCP_GetUnusedPort()
 425  * \brief Gets an unused port and allocates it
 426  */
 427 Uint16 TCP_GetUnusedPort()
 428 {
 429         Uint16  ret;
 430
 431         // Get Next outbound port
 432         ret = giTCP_NextOutPort++;
 433         while( gaTCP_PortBitmap[ret/32] & (1 << (ret%32)) )
 434         {
 435                 ret ++;
 436                 giTCP_NextOutPort++;
 437                 if(giTCP_NextOutPort == 0x10000) {
 438                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 439                 }
 440         }
 441
 442         // Mark the new port as used
 443         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 444
 445         return ret;
 446 }
 447
 448 /**
 449  * \fn int TCP_AllocatePort(Uint16 Port)
 450  * \brief Marks a port as used
 451  */
 452 int TCP_AllocatePort(Uint16 Port)
 453 {
 454         // Check if the port has already been allocated
 455         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 456                 return 0;
 457
 458         // Allocate
 459         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 460
 461         return 1;
 462 }
 463
 464 /**
 465  * \fn int TCP_DeallocatePort(Uint16 Port)
 466  * \brief Marks a port as unused
 467  */
 468 int TCP_DeallocatePort(Uint16 Port)
 469 {
 470         // Check if the port has already been allocated
 471         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 472                 return 0;
 473
 474         // Allocate
 475         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 476
 477         return 1;
 478 }
 479
 480 // --- Server
 481 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 482 {
 483         tTCPListener    *srv = malloc( sizeof(tTCPListener) );
 484
 485         srv->Interface = Interface;
 486         srv->Port = 0;
 487         srv->NextID = 0;
 488         srv->Connections = NULL;
 489         srv->Next = NULL;
 490         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 491         srv->Node.Size = -1;
 492         srv->Node.ImplPtr = srv;
 493         srv->Node.NumACLs = 1;
 494         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 495         srv->Node.ReadDir = TCP_Server_ReadDir;
 496         srv->Node.FindDir = TCP_Server_FindDir;
 497         srv->Node.IOCtl = TCP_Server_IOCtl;
 498         srv->Node.Close = TCP_Server_Close;
 499
 500         LOCK(&glTCP_Listeners);
 501         srv->Next = gTCP_Listeners;
 502         gTCP_Listeners = srv;
 503         RELEASE(&glTCP_Listeners);
 504
 505         return &srv->Node;
 506 }
 507
 508 /**
 509  * \brief Wait for a new connection and return the connection ID
 510  * \note Blocks until a new connection is made
 511  * \param Node  Server node
 512  * \param Pos   Position (ignored)
 513  */
 514 char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
 515 {
 516         tTCPListener    *srv = Node->ImplPtr;
 517         tTCPConnection  *conn;
 518         char    *ret;
 519
 520         Log("[TCP  ] Thread %i waiting for a connection", Threads_GetTID());
 521         for(;;)
 522         {
 523                 LOCK( &srv->lConnections );
 524                 if( srv->NewConnections != NULL )       break;
 525                 RELEASE( &srv->lConnections );
 526                 Threads_Yield();
 527                 continue;
 528         }
 529
 530
 531         // Increment the new list (the current connection is still on the
 532         // normal list
 533         conn = srv->NewConnections;
 534         srv->NewConnections = conn->Next;
 535
 536         RELEASE( &srv->lConnections );
 537
 538         ret = malloc(9);
 539         itoa(ret, Node->ImplInt, 16, 8, '0');
 540         Log("TCP_Server_ReadDir: RETURN '%s'", ret);
 541         return ret;
 542 }
 543
 544 /**
 545  * \brief Gets a client connection node
 546  * \param Node  Server node
 547  * \param Name  Hexadecimal ID of the node
 548  */
 549 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, char *Name)
 550 {
 551         tTCPConnection  *conn;
 552         tTCPListener    *srv = Node->ImplPtr;
 553         char    tmp[9];
 554          int    id = atoi(Name);
 555
 556         // Sanity Check
 557         itoa(tmp, id, 16, 8, '0');
 558         if(strcmp(tmp, Name) != 0)      return NULL;
 559
 560         // Search
 561         LOCK( &srv->lConnections );
 562         for(conn = srv->Connections;
 563                 conn && conn->Node.ImplInt != id;
 564                 conn = conn->Next);
 565         RELEASE( &srv->lConnections );
 566
 567         // If not found, ret NULL
 568         if(!conn)       return NULL;
 569
 570         // Return node
 571         return &conn->Node;
 572 }
 573
 574 /**
 575  * \brief Handle IOCtl calls
 576  */
 577 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
 578 {
 579         tTCPListener    *srv = Node->ImplPtr;
 580
 581         switch(ID)
 582         {
 583         case 4: // Get/Set Port
 584                 if(!Data)       // Get Port
 585                         return srv->Port;
 586
 587                 if(srv->Port)   // Wait, you can't CHANGE the port
 588                         return -1;
 589
 590                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
 591                         return -1;
 592
 593                 // Permissions check
 594                 if(Threads_GetUID() != 0
 595                 && *(Uint16*)Data != 0
 596                 && *(Uint16*)Data < 1024)
 597                         return -1;
 598
 599                 // TODO: Check if a port is in use
 600
 601                 // Set Port
 602                 srv->Port = *(Uint16*)Data;
 603                 if(srv->Port == 0)      // Allocate a random port
 604                         srv->Port = TCP_GetUnusedPort();
 605                 else    // Else, mark this as used
 606                         TCP_AllocatePort(srv->Port);
 607
 608                 Log("[TCP  ] Server %p listening on port %i", srv, srv->Port);
 609
 610                 return srv->Port;
 611         }
 612         return 0;
 613 }
 614
 615 void TCP_Server_Close(tVFS_Node *Node)
 616 {
 617         free(Node->ImplPtr);
 618 }
 619
 620 // --- Client
 621 /**
 622  * \brief Create a client node
 623  */
 624 tVFS_Node *TCP_Client_Init(tInterface *Interface)
 625 {
 626         tTCPConnection  *conn = malloc( sizeof(tTCPConnection) );
 627
 628         conn->State = TCP_ST_CLOSED;
 629         conn->Interface = Interface;
 630         conn->LocalPort = 0;
 631         conn->RemotePort = 0;
 632         memset( &conn->RemoteIP, 0, sizeof(conn->RemoteIP) );
 633
 634         conn->Node.ImplPtr = conn;
 635         conn->Node.NumACLs = 1;
 636         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 637         conn->Node.Read = TCP_Client_Read;
 638         conn->Node.Write = TCP_Client_Write;
 639         conn->Node.IOCtl = TCP_Client_IOCtl;
 640         conn->Node.Close = TCP_Client_Close;
 641
 642         LOCK(&glTCP_OutbountCons);
 643         conn->Next = gTCP_OutbountCons;
 644         gTCP_OutbountCons = conn;
 645         RELEASE(&glTCP_OutbountCons);
 646
 647         return &conn->Node;
 648 }
 649
 650 /**
 651  * \brief Wait for a packet and return it
 652  * \note If \a Length is smaller than the size of the packet, the rest
 653  *       of the packet's data will be discarded.
 654  */
 655 Uint64 TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 656 {
 657         tTCPConnection  *conn = Node->ImplPtr;
 658         tTCPStoredPacket        *pkt;
 659
 660         Log("TCP_Client_Read: (Length=%i)", Length);
 661
 662         // Check if connection is open
 663         if( conn->State != TCP_ST_OPEN )        return 0;
 664
 665         // Poll packets
 666         for(;;)
 667         {
 668                 // Lock list and check if there is a packet
 669                 LOCK( &conn->lRecievedPackets );
 670                 if( conn->RecievedPackets == NULL ) {
 671                         // If not, release the lock, yield and try again
 672                         RELEASE( &conn->lRecievedPackets );
 673                         Threads_Yield();
 674                         continue;
 675                 }
 676
 677                 // Get packet pointer
 678                 pkt = conn->RecievedPackets;
 679                 conn->RecievedPackets = pkt->Next;
 680                 // Release the lock (we don't need it any more)
 681                 RELEASE( &conn->lRecievedPackets );
 682
 683                 Log("TCP_Client_Read: pkt->Length = %i", pkt->Length);
 684
 685                 // Copy Data
 686                 if(Length > pkt->Length)        Length = pkt->Length;
 687                 memcpy(Buffer, pkt->Data, Length);
 688
 689                 // Free packet and return
 690                 free(pkt);
 691                 return Length;
 692         }
 693 }
 694
 695 Uint64 TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 696 {
 697         return 0;
 698 }
 699
 700 /**
 701  * \brief Control a client socket
 702  */
 703 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
 704 {
 705         tTCPConnection  *conn = Node->ImplPtr;
 706
 707         switch(ID)
 708         {
 709         case 4: // Get/Set local port
 710                 if(!Data)
 711                         return conn->LocalPort;
 712                 if(conn->State != TCP_ST_CLOSED)
 713                         return -1;
 714                 if(!CheckMem(Data, sizeof(Uint16)))
 715                         return -1;
 716
 717                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
 718                         return -1;
 719
 720                 conn->LocalPort = *(Uint16*)Data;
 721                 return 0;
 722
 723         case 5: // Get/Set remote port
 724                 if(!Data)       return conn->RemotePort;
 725                 if(conn->State != TCP_ST_CLOSED)        return -1;
 726                 if(!CheckMem(Data, sizeof(Uint16)))     return -1;
 727                 conn->RemotePort = *(Uint16*)Data;
 728                 return 0;
 729
 730         case 6: // Set Remote IP
 731                 if( conn->State != TCP_ST_CLOSED )
 732                         return -1;
 733                 if( conn->Interface->Type == 4 )
 734                 {
 735                         if(!CheckMem(Data, sizeof(tIPv4)))      return -1;
 736                         conn->RemoteIP.v4 = *(tIPv4*)Data;
 737                 }
 738                 else if( conn->Interface->Type == 6 )
 739                 {
 740                         if(!CheckMem(Data, sizeof(tIPv6)))      return -1;
 741                         conn->RemoteIP.v6 = *(tIPv6*)Data;
 742                 }
 743                 return 0;
 744
 745         case 7: // Connect
 746                 if(conn->LocalPort == -1)
 747                         conn->LocalPort = TCP_GetUnusedPort();
 748                 if(conn->RemotePort == -1)
 749                         return 0;
 750
 751                 TCP_StartConnection(conn);
 752                 return 1;
 753         }
 754
 755         return 0;
 756 }
 757
 758 void TCP_Client_Close(tVFS_Node *Node)
 759 {
 760         free(Node->ImplPtr);
 761 }