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  * \fn void TCP_Initialise()
  52  * \brief Initialise the TCP Layer
  53  */
  54 void TCP_Initialise()
  55 {
  56         IPStack_AddFile(&gTCP_ServerFile);
  57         IPStack_AddFile(&gTCP_ClientFile);
  58         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  59 }
  60
  61 /**
  62  * \brief Open a connection to another host using TCP
  63  */
  64 void TCP_StartConnection(tTCPConnection *Conn)
  65 {
  66         tTCPHeader      hdr;
  67
  68         hdr.SourcePort = Conn->LocalPort;
  69         hdr.DestPort = Conn->RemotePort;
  70         Conn->NextSequenceSend = rand();
  71         hdr.SequenceNumber = Conn->NextSequenceSend;
  72         hdr.DataOffset = (sizeof(tTCPHeader)+3)/4;
  73         hdr.Flags = TCP_FLAG_SYN;
  74         hdr.WindowSize = 0;     // TODO
  75         hdr.Checksum = 0;       // TODO
  76         hdr.UrgentPointer = 0;
  77         // SEND PACKET
  78         TCP_SendPacket( Conn, sizeof(tTCPHeader), &hdr );
  79         return ;
  80 }
  81
  82 /**
  83  * \brief Sends a packet from the specified connection, calculating the checksums
  84  * \param Conn  Connection
  85  * \param Length        Length of data
  86  * \param Data  Packet data
  87  */
  88 void TCP_SendPacket( tTCPConnection *Conn, size_t Length, tTCPHeader *Data )
  89 {
  90         size_t  buflen;
  91         Uint32  *buf;
  92         switch( Conn->Interface->Type )
  93         {
  94         case 4: // Append IPv4 Pseudo Header
  95                 buflen = 4 + 4 + 4 + ((Length+1)&~1);
  96                 buf = malloc( buflen );
  97                 buf[0] = Conn->Interface->IP4.Address.L;
  98                 buf[1] = Conn->RemoteIP.v4.L;
  99                 buf[2] = (htons(Length)<<16) | (6<<8) | 0;
 100                 Data->Checksum = 0;
 101                 memcpy( &buf[3], Data, Length );
 102                 Data->Checksum = IPv4_Checksum( buf, buflen );
 103                 free(buf);
 104                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, buflen, buf);
 105                 break;
 106         }
 107 }
 108
 109 /**
 110  * \fn void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 111  * \brief Handles a packet from the IP Layer
 112  */
 113 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 114 {
 115         tTCPHeader      *hdr = Buffer;
 116         tTCPListener    *srv;
 117         tTCPConnection  *conn;
 118
 119         Log("[TCP  ] sizeof(tTCPHeader) = %i", sizeof(tTCPHeader));
 120         Log("[TCP  ] SourcePort = %i", ntohs(hdr->SourcePort));
 121         Log("[TCP  ] DestPort = %i", ntohs(hdr->DestPort));
 122         Log("[TCP  ] SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 123         Log("[TCP  ] AcknowlegementNumber = 0x%x", ntohl(hdr->AcknowlegementNumber));
 124         Log("[TCP  ] DataOffset = %i", hdr->DataOffset >> 4);
 125         Log("[TCP  ] Flags = {");
 126         Log("[TCP  ]   CWR = %B", !!(hdr->Flags & TCP_FLAG_CWR));
 127         Log("[TCP  ]   ECE = %B", !!(hdr->Flags & TCP_FLAG_ECE));
 128         Log("[TCP  ]   URG = %B", !!(hdr->Flags & TCP_FLAG_URG));
 129         Log("[TCP  ]   ACK = %B", !!(hdr->Flags & TCP_FLAG_ACK));
 130         Log("[TCP  ]   PSH = %B", !!(hdr->Flags & TCP_FLAG_PSH));
 131         Log("[TCP  ]   RST = %B", !!(hdr->Flags & TCP_FLAG_RST));
 132         Log("[TCP  ]   SYN = %B", !!(hdr->Flags & TCP_FLAG_SYN));
 133         Log("[TCP  ]   FIN = %B", !!(hdr->Flags & TCP_FLAG_FIN));
 134         Log("[TCP  ] }");
 135         Log("[TCP  ] WindowSize = %i", htons(hdr->WindowSize));
 136         Log("[TCP  ] Checksum = 0x%x", htons(hdr->Checksum));
 137         Log("[TCP  ] UrgentPointer = 0x%x", htons(hdr->UrgentPointer));
 138
 139         // Check Servers
 140         {
 141                 for( srv = gTCP_Listeners; srv; srv = srv->Next )
 142                 {
 143                         Log("[TCP  ] Server %p, Port = 0x%04x", srv, srv->Port);
 144                         // Check if the server is active
 145                         if(srv->Port == 0)      continue;
 146                         // Check the interface
 147                         Log("[TCP  ]  Interface = %p (== %p ?)", srv->Interface, Interface);
 148                         if(srv->Interface && srv->Interface != Interface)       continue;
 149                         // Check the destination port
 150                         Log("[TCP  ]  hdr->DestPort = 0x%04x", ntohs(hdr->DestPort));
 151                         if(srv->Port != htons(hdr->DestPort))   continue;
 152
 153                         Log("[TCP  ] Matches");
 154                         // Is this in an established connection?
 155                         for( conn = srv->Connections; conn; conn = conn->Next )
 156                         {
 157                                 // Check that it is coming in on the same interface
 158                                 if(conn->Interface != Interface)        continue;
 159
 160                                 // Check Source Port
 161                                 if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 162
 163                                 // Check Source IP
 164                                 if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 165                                         continue;
 166                                 if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 167                                         continue;
 168
 169                                 // We have a response!
 170                                 TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 171
 172                                 return;
 173                         }
 174
 175                         Log("[TCP  ] Opening Connection");
 176                         // Open a new connection (well, check that it's a SYN)
 177                         if(hdr->Flags != TCP_FLAG_SYN) {
 178                                 Log("[TCP  ] Packet is not a SYN");
 179                                 continue;
 180                         }
 181
 182                         // TODO: Check for halfopen max
 183
 184                         conn = calloc(1, sizeof(tTCPConnection));
 185                         conn->State = TCP_ST_HALFOPEN;
 186                         conn->LocalPort = srv->Port;
 187                         conn->RemotePort = ntohs(hdr->SourcePort);
 188                         conn->Interface = Interface;
 189
 190                         switch(Interface->Type)
 191                         {
 192                         case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 193                         case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 194                         }
 195
 196                         conn->NextSequenceRcv = ntohl( hdr->SequenceNumber );
 197                         conn->NextSequenceSend = rand();
 198
 199                         // Create node
 200                         conn->Node.NumACLs = 1;
 201                         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 202                         conn->Node.ImplInt = srv->NextID ++;
 203                         conn->Node.Read = TCP_Client_Read;
 204                         conn->Node.Write = TCP_Client_Write;
 205                         //conn->Node.Close = TCP_SrvConn_Close;
 206
 207                         // Hmm... Theoretically, this lock will never have to wait,
 208                         // as the interface is locked to the watching thread, and this
 209                         // runs in the watching thread. But, it's a good idea to have
 210                         // it, just in case
 211                         LOCK(&srv->lConnections);
 212                         conn->Next = srv->Connections;
 213                         srv->Connections = conn;
 214                         RELEASE(&srv->lConnections);
 215
 216                         // Send the SYN ACK
 217                         Log("[TCP  ] TODO: Sending SYN ACK");
 218                         hdr->Flags |= TCP_FLAG_ACK;
 219                         hdr->AcknowlegementNumber = hdr->SequenceNumber;
 220                         hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 221                         hdr->DestPort = hdr->SourcePort;
 222                         hdr->SourcePort = htonl(srv->Port);
 223                         TCP_SendPacket( conn, sizeof(tTCPHeader), hdr );
 224
 225                         break;
 226                 }
 227         }
 228
 229
 230         // Check Open Connections
 231         {
 232                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 233                 {
 234                         // Check that it is coming in on the same interface
 235                         if(conn->Interface != Interface)        continue;
 236
 237                         // Check Source Port
 238                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 239
 240                         // Check Source IP
 241                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 242                                 continue;
 243                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 244                                 continue;
 245
 246                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 247                 }
 248         }
 249 }
 250
 251 /**
 252  * \brief Handles a packet sent to a specific connection
 253  */
 254 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 255 {
 256         tTCPStoredPacket        *pkt;
 257          int    dataLen;
 258
 259         Connection->State = TCP_ST_OPEN;
 260         if(Header->Flags & TCP_FLAG_SYN) {
 261                 Connection->NextSequenceRcv = Header->SequenceNumber + 1;
 262         }
 263
 264         if(Header->Flags & TCP_FLAG_ACK) {
 265                 // TODO: Process an ACKed Packet
 266                 Log("[TCP  ] Conn %p, Packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 267                 return ;
 268         }
 269
 270         // Allocate and fill cached packet
 271         dataLen =  Length - (Header->DataOffset&0xF)*4;
 272         pkt = malloc( dataLen + sizeof(tTCPStoredPacket) );
 273         pkt->Next = NULL;
 274         pkt->Sequence = Header->SequenceNumber;
 275         memcpy(pkt->Data, (Uint8*)Header + (Header->DataOffset&0xF)*4, dataLen);
 276
 277         // Is this packet the next expected packet?
 278         if( Header->SequenceNumber != Connection->NextSequenceRcv )
 279         {
 280                 tTCPStoredPacket        *tmp, *prev;
 281                 // No? Well, let's cache it and look at it later
 282                 LOCK( &Connection->lFuturePackets );
 283                 for(tmp = Connection->FuturePackets;
 284                         tmp;
 285                         prev = tmp, tmp = tmp->Next)
 286                 {
 287                         if(tmp->Sequence > pkt->Sequence)       break;
 288                 }
 289                 if(prev)
 290                         prev->Next = pkt;
 291                 else
 292                         Connection->FuturePackets = pkt;
 293                 pkt->Next = tmp;
 294                 RELEASE( &Connection->lFuturePackets );
 295         }
 296         else
 297         {
 298                 // Ooh, Goodie! Add it to the recieved list
 299                 TCP_INT_AppendRecieved(Connection, pkt);
 300                 Connection->NextSequenceRcv ++;
 301
 302                 // TODO: This should be moved out of the watcher thread,
 303                 // so that a single lost packet on one connection doesn't cause
 304                 // all connections on the interface to lag.
 305                 TCP_INT_UpdateRecievedFromFuture(Connection);
 306         }
 307
 308         // TODO: Check ACK code validity
 309         Header->AcknowlegementNumber = pkt->Sequence;
 310         Header->SequenceNumber = Connection->NextSequenceSend;
 311         Header->Flags |= TCP_FLAG_ACK;
 312         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 313 }
 314
 315 /**
 316  * \brief Appends a packet to the recieved list
 317  */
 318 void TCP_INT_AppendRecieved(tTCPConnection *Connection, tTCPStoredPacket *Pkt)
 319 {
 320         LOCK( &Connection->lRecievedPackets );
 321         if(Connection->RecievedPackets)
 322         {
 323                 Connection->RecievedPacketsTail->Next = Pkt;
 324                 Connection->RecievedPacketsTail = Pkt;
 325         }
 326         else
 327         {
 328                 Connection->RecievedPackets = Pkt;
 329                 Connection->RecievedPacketsTail = Pkt;
 330         }
 331         RELEASE( &Connection->lRecievedPackets );
 332 }
 333
 334 /**
 335  * \brief Updates the connections recieved list from the future list
 336  */
 337 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 338 {
 339         tTCPStoredPacket        *pkt, *prev;
 340         for(;;)
 341         {
 342                 prev = NULL;
 343                 // Look for the next expected packet in the cache.
 344                 LOCK( &Connection->lFuturePackets );
 345                 for(pkt = Connection->FuturePackets;
 346                         pkt && pkt->Sequence < Connection->NextSequenceRcv;
 347                         prev = pkt, pkt = pkt->Next);
 348
 349                 // If we can't find the expected next packet, stop looking
 350                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 351                         RELEASE( &Connection->lFuturePackets );
 352                         return;
 353                 }
 354
 355                 // Delete packet from future list
 356                 if(prev)
 357                         prev->Next = pkt->Next;
 358                 else
 359                         Connection->FuturePackets = pkt->Next;
 360
 361                 // Release list
 362                 RELEASE( &Connection->lFuturePackets );
 363
 364                 // Looks like we found one
 365                 TCP_INT_AppendRecieved(Connection, pkt);
 366                 Connection->NextSequenceRcv ++;
 367         }
 368 }
 369
 370 /**
 371  * \fn Uint16 TCP_GetUnusedPort()
 372  * \brief Gets an unused port and allocates it
 373  */
 374 Uint16 TCP_GetUnusedPort()
 375 {
 376         Uint16  ret;
 377
 378         // Get Next outbound port
 379         ret = giTCP_NextOutPort++;
 380         while( gaTCP_PortBitmap[ret/32] & (1 << (ret%32)) )
 381         {
 382                 ret ++;
 383                 giTCP_NextOutPort++;
 384                 if(giTCP_NextOutPort == 0x10000) {
 385                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 386                 }
 387         }
 388
 389         // Mark the new port as used
 390         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 391
 392         return ret;
 393 }
 394
 395 /**
 396  * \fn int TCP_AllocatePort(Uint16 Port)
 397  * \brief Marks a port as used
 398  */
 399 int TCP_AllocatePort(Uint16 Port)
 400 {
 401         // Check if the port has already been allocated
 402         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 403                 return 0;
 404
 405         // Allocate
 406         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 407
 408         return 1;
 409 }
 410
 411 /**
 412  * \fn int TCP_DeallocatePort(Uint16 Port)
 413  * \brief Marks a port as unused
 414  */
 415 int TCP_DeallocatePort(Uint16 Port)
 416 {
 417         // Check if the port has already been allocated
 418         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 419                 return 0;
 420
 421         // Allocate
 422         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 423
 424         return 1;
 425 }
 426
 427 // --- Server
 428 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 429 {
 430         tTCPListener    *srv = malloc( sizeof(tTCPListener) );
 431
 432         srv->Interface = Interface;
 433         srv->Port = 0;
 434         srv->NextID = 0;
 435         srv->Connections = NULL;
 436         srv->Next = NULL;
 437         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 438         srv->Node.Size = -1;
 439         srv->Node.ImplPtr = srv;
 440         srv->Node.NumACLs = 1;
 441         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 442         srv->Node.ReadDir = TCP_Server_ReadDir;
 443         srv->Node.FindDir = TCP_Server_FindDir;
 444         srv->Node.IOCtl = TCP_Server_IOCtl;
 445         srv->Node.Close = TCP_Server_Close;
 446
 447         LOCK(&glTCP_Listeners);
 448         srv->Next = gTCP_Listeners;
 449         gTCP_Listeners = srv;
 450         RELEASE(&glTCP_Listeners);
 451
 452         return &srv->Node;
 453 }
 454
 455 /**
 456  * \brief Wait for a new connection and return the connection ID
 457  * \note Blocks until a new connection is made
 458  * \param Node  Server node
 459  * \param Pos   Position (ignored)
 460  */
 461 char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
 462 {
 463         tTCPListener    *srv = Node->ImplPtr;
 464         tTCPConnection  *conn;
 465         char    *ret;
 466
 467         while( srv->NewConnections == NULL )    Threads_Yield();
 468
 469         conn = srv->NewConnections;
 470         srv->NewConnections = conn->Next;
 471
 472         ret = malloc(9);
 473         itoa(ret, Node->ImplInt, 16, '0', 8);
 474         return ret;
 475 }
 476
 477 /**
 478  * \brief Gets a client connection node
 479  * \param Node  Server node
 480  * \param Name  Hexadecimal ID of the node
 481  */
 482 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, char *Name)
 483 {
 484         return NULL;
 485 }
 486
 487 /**
 488  * \brief Handle IOCtl calls
 489  */
 490 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
 491 {
 492         tTCPListener    *srv = Node->ImplPtr;
 493
 494         switch(ID)
 495         {
 496         case 4: // Get/Set Port
 497                 if(!Data)       // Get Port
 498                         return srv->Port;
 499
 500                 if(srv->Port)   // Wait, you can't CHANGE the port
 501                         return -1;
 502
 503                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
 504                         return -1;
 505
 506                 // Permissions check
 507                 if(Threads_GetUID() != 0
 508                 && *(Uint16*)Data != 0
 509                 && *(Uint16*)Data < 1024)
 510                         return -1;
 511
 512                 // TODO: Check if a port is in use
 513
 514                 // Set Port
 515                 srv->Port = *(Uint16*)Data;
 516                 if(srv->Port == 0)      // Allocate a random port
 517                         srv->Port = TCP_GetUnusedPort();
 518                 else    // Else, mark this as used
 519                         TCP_AllocatePort(srv->Port);
 520
 521                 Log("[TCP  ] Server %p listening on port %i", srv, srv->Port);
 522
 523                 return srv->Port;
 524         }
 525         return 0;
 526 }
 527
 528 void TCP_Server_Close(tVFS_Node *Node)
 529 {
 530         free(Node->ImplPtr);
 531 }
 532
 533 // --- Client
 534 /**
 535  * \brief Create a client node
 536  */
 537 tVFS_Node *TCP_Client_Init(tInterface *Interface)
 538 {
 539         tTCPConnection  *conn = malloc( sizeof(tTCPConnection) );
 540
 541         conn->State = TCP_ST_CLOSED;
 542         conn->Interface = Interface;
 543         conn->LocalPort = 0;
 544         conn->RemotePort = 0;
 545         memset( &conn->RemoteIP, 0, sizeof(conn->RemoteIP) );
 546
 547         conn->Node.ImplPtr = conn;
 548         conn->Node.NumACLs = 1;
 549         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 550         conn->Node.Read = TCP_Client_Read;
 551         conn->Node.Write = TCP_Client_Write;
 552         conn->Node.IOCtl = TCP_Client_IOCtl;
 553         conn->Node.Close = TCP_Client_Close;
 554
 555         LOCK(&glTCP_OutbountCons);
 556         conn->Next = gTCP_OutbountCons;
 557         gTCP_OutbountCons = conn;
 558         RELEASE(&glTCP_OutbountCons);
 559
 560         return &conn->Node;
 561 }
 562
 563 /**
 564  * \brief Wait for a packet and return it
 565  * \note If \a Length is smaller than the size of the packet, the rest
 566  *       of the packet's data will be discarded.
 567  */
 568 Uint64 TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 569 {
 570         tTCPConnection  *conn = Node->ImplPtr;
 571         tTCPStoredPacket        *pkt;
 572
 573         // Check if connection is open
 574         if( conn->State != TCP_ST_OPEN )        return 0;
 575
 576         // Poll packets
 577         for(;;)
 578         {
 579                 // Sleep until the packet is recieved
 580                 while( conn->RecievedPackets == NULL )
 581                         Threads_Yield();
 582                 //      Threads_Sleep();
 583
 584                 // Lock list and check if there is a packet
 585                 LOCK( &conn->lRecievedPackets );
 586                 if( conn->RecievedPackets == NULL ) {
 587                         // If not, release the lock and return to waiting
 588                         RELEASE( &conn->lRecievedPackets );
 589                         continue;
 590                 }
 591
 592                 // Get packet pointer
 593                 pkt = conn->RecievedPackets;
 594                 conn->RecievedPackets = pkt->Next;
 595                 // Release the lock (we don't need it any more)
 596                 RELEASE( &conn->lRecievedPackets );
 597
 598                 // Copy Data
 599                 if(Length > pkt->Length)        Length = pkt->Length;
 600                 memcpy(Buffer, pkt->Data, Length);
 601
 602                 // Free packet and return
 603                 free(pkt);
 604                 return Length;
 605         }
 606 }
 607
 608 Uint64 TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 609 {
 610         return 0;
 611 }
 612
 613 /**
 614  * \brief Control a client socket
 615  */
 616 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
 617 {
 618         tTCPConnection  *conn = Node->ImplPtr;
 619
 620         switch(ID)
 621         {
 622         case 4: // Get/Set local port
 623                 if(!Data)
 624                         return conn->LocalPort;
 625                 if(conn->State != TCP_ST_CLOSED)
 626                         return -1;
 627                 if(!CheckMem(Data, sizeof(Uint16)))
 628                         return -1;
 629
 630                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
 631                         return -1;
 632
 633                 conn->LocalPort = *(Uint16*)Data;
 634                 return 0;
 635
 636         case 5: // Get/Set remote port
 637                 if(!Data)       return conn->RemotePort;
 638                 if(conn->State != TCP_ST_CLOSED)        return -1;
 639                 if(!CheckMem(Data, sizeof(Uint16)))     return -1;
 640                 conn->RemotePort = *(Uint16*)Data;
 641                 return 0;
 642
 643         case 6: // Set Remote IP
 644                 if( conn->State != TCP_ST_CLOSED )
 645                         return -1;
 646                 if( conn->Interface->Type == 4 )
 647                 {
 648                         if(!CheckMem(Data, sizeof(tIPv4)))      return -1;
 649                         conn->RemoteIP.v4 = *(tIPv4*)Data;
 650                 }
 651                 else if( conn->Interface->Type == 6 )
 652                 {
 653                         if(!CheckMem(Data, sizeof(tIPv6)))      return -1;
 654                         conn->RemoteIP.v6 = *(tIPv6*)Data;
 655                 }
 656                 return 0;
 657
 658         case 7: // Connect
 659                 if(conn->LocalPort == -1)
 660                         conn->LocalPort = TCP_GetUnusedPort();
 661                 if(conn->RemotePort == -1)
 662                         return 0;
 663
 664                 TCP_StartConnection(conn);
 665                 return 1;
 666         }
 667
 668         return 0;
 669 }
 670
 671 void TCP_Client_Close(tVFS_Node *Node)
 672 {
 673         free(Node->ImplPtr);
 674 }