Modules/IPStack/tcp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - TCP Handling
   4  */
   5 #define DEBUG   1
   6 #include "ipstack.h"
   7 #include "ipv4.h"
   8 #include "ipv6.h"
   9 #include "tcp.h"
  10
  11 #define USE_SELECT      1
  12 #define HEXDUMP_INCOMING        0
  13 #define HEXDUMP_OUTGOING        0
  14 #define CACHE_FUTURE_PACKETS_IN_BYTES   1       // Use a ring buffer to cache out of order packets
  15
  16 #define TCP_MIN_DYNPORT 0xC000
  17 #define TCP_MAX_HALFOPEN        1024    // Should be enough
  18
  19 #define TCP_MAX_PACKET_SIZE     1024
  20 #define TCP_WINDOW_SIZE 0x2000
  21 #define TCP_RECIEVE_BUFFER_SIZE 0x4000
  22
  23 // === PROTOTYPES ===
  24 void    TCP_Initialise(void);
  25 void    TCP_StartConnection(tTCPConnection *Conn);
  26 void    TCP_SendPacket(tTCPConnection *Conn, size_t Length, tTCPHeader *Data);
  27 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  28 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  29 int     TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length);
  30 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  31 Uint16  TCP_GetUnusedPort();
  32  int    TCP_AllocatePort(Uint16 Port);
  33  int    TCP_DeallocatePort(Uint16 Port);
  34 // --- Server
  35 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  36 char    *TCP_Server_ReadDir(tVFS_Node *Node, int Pos);
  37 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, const char *Name);
  38  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  39 void    TCP_Server_Close(tVFS_Node *Node);
  40 // --- Client
  41 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  42 Uint64  TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  43 Uint64  TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  44  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  45 void    TCP_Client_Close(tVFS_Node *Node);
  46 // --- Helpers
  47  int    WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
  48
  49 // === TEMPLATES ===
  50 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  51 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  52
  53 // === GLOBALS ===
  54  int    giTCP_NumHalfopen = 0;
  55 tShortSpinlock  glTCP_Listeners;
  56 tTCPListener    *gTCP_Listeners;
  57 tShortSpinlock  glTCP_OutbountCons;
  58 tTCPConnection  *gTCP_OutbountCons;
  59 Uint32  gaTCP_PortBitmap[0x800];
  60  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  61
  62 // === CODE ===
  63 /**
  64  * \brief Initialise the TCP Layer
  65  *
  66  * Registers the client and server files and the GetPacket callback
  67  */
  68 void TCP_Initialise(void)
  69 {
  70         giTCP_NextOutPort += rand()%32;
  71         IPStack_AddFile(&gTCP_ServerFile);
  72         IPStack_AddFile(&gTCP_ClientFile);
  73         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  74         IPv6_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  75 }
  76
  77 /**
  78  * \brief Sends a packet from the specified connection, calculating the checksums
  79  * \param Conn  Connection
  80  * \param Length        Length of data
  81  * \param Data  Packet data (cast as a TCP Header)
  82  */
  83 void TCP_SendPacket( tTCPConnection *Conn, size_t Length, tTCPHeader *Data )
  84 {
  85         Uint16  checksum[2];
  86
  87         Data->Checksum = 0;
  88         checksum[1] = htons( ~IPv4_Checksum( (void*)Data, Length ) );   // Partial checksum
  89         if(Length & 1)
  90                 ((Uint8*)Data)[Length] = 0;
  91
  92         // TODO: Fragment packet
  93
  94         switch( Conn->Interface->Type )
  95         {
  96         case 4:
  97                 // Append IPv4 Pseudo Header
  98                 {
  99                         Uint32  buf[3];
 100                         buf[0] = ((tIPv4*)Conn->Interface->Address)->L;
 101                         buf[1] = Conn->RemoteIP.v4.L;
 102                         buf[2] = (htons(Length)<<16) | (6<<8) | 0;
 103                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 104                 }
 105                 Data->Checksum = htons( IPv4_Checksum(checksum, 2*2) ); // Combine the two
 106                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, Length, Data);
 107                 break;
 108
 109         case 6:
 110                 // Append IPv6 Pseudo Header
 111                 {
 112                         Uint32  buf[4+4+1+1];
 113                         memcpy(buf, Conn->Interface->Address, 16);
 114                         memcpy(&buf[4], &Conn->RemoteIP, 16);
 115                         buf[8] = htonl(Length);
 116                         buf[9] = htonl(6);
 117                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 118                 }
 119                 Data->Checksum = htons( IPv4_Checksum(checksum, 2*2) ); // Combine the two
 120                 IPv6_SendPacket(Conn->Interface, Conn->RemoteIP.v6, IP4PROT_TCP, Length, Data);
 121                 break;
 122         }
 123 }
 124
 125 /**
 126  * \brief Handles a packet from the IP Layer
 127  * \param Interface     Interface the packet arrived from
 128  * \param Address       Pointer to the addres structure
 129  * \param Length        Size of packet in bytes
 130  * \param Buffer        Packet data
 131  */
 132 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 133 {
 134         tTCPHeader      *hdr = Buffer;
 135         tTCPListener    *srv;
 136         tTCPConnection  *conn;
 137
 138         Log_Log("TCP", "TCP_GetPacket: SourcePort = %i, DestPort = %i",
 139                 ntohs(hdr->SourcePort), ntohs(hdr->DestPort));
 140 /*
 141         Log_Log("TCP", "TCP_GetPacket: SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 142         Log_Log("TCP", "TCP_GetPacket: AcknowlegementNumber = 0x%x", ntohl(hdr->AcknowlegementNumber));
 143         Log_Log("TCP", "TCP_GetPacket: DataOffset = %i", hdr->DataOffset >> 4);
 144         Log_Log("TCP", "TCP_GetPacket: WindowSize = %i", htons(hdr->WindowSize));
 145         Log_Log("TCP", "TCP_GetPacket: Checksum = 0x%x", htons(hdr->Checksum));
 146         Log_Log("TCP", "TCP_GetPacket: UrgentPointer = 0x%x", htons(hdr->UrgentPointer));
 147 */
 148         Log_Log("TCP", "TCP_GetPacket: Flags = %s%s%s%s%s%s%s%s",
 149                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
 150                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
 151                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
 152                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
 153                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
 154                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
 155                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
 156                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
 157                 );
 158
 159         if( Length > (hdr->DataOffset >> 4)*4 )
 160         {
 161                 Log_Log("TCP", "TCP_GetPacket: SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 162 #if HEXDUMP_INCOMING
 163                 Debug_HexDump(
 164                         "TCP_GetPacket: Packet Data = ",
 165                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 166                         Length - (hdr->DataOffset >> 4)*4
 167                         );
 168 #endif
 169         }
 170
 171         // Check Servers
 172         {
 173                 for( srv = gTCP_Listeners; srv; srv = srv->Next )
 174                 {
 175                         // Check if the server is active
 176                         if(srv->Port == 0)      continue;
 177                         // Check the interface
 178                         if(srv->Interface && srv->Interface != Interface)       continue;
 179                         // Check the destination port
 180                         if(srv->Port != htons(hdr->DestPort))   continue;
 181
 182                         Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 183                         // Is this in an established connection?
 184                         for( conn = srv->Connections; conn; conn = conn->Next )
 185                         {
 186                                 Log_Log("TCP", "TCP_GetPacket: conn->Interface(%p) == Interface(%p)",
 187                                         conn->Interface, Interface);
 188                                 // Check that it is coming in on the same interface
 189                                 if(conn->Interface != Interface)        continue;
 190
 191                                 // Check Source Port
 192                                 Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 193                                         conn->RemotePort, ntohs(hdr->SourcePort));
 194                                 if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 195
 196                                 // Check Source IP
 197                                 if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) != 0 )
 198                                         continue ;
 199
 200                                 Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 201                                 // We have a response!
 202                                 TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 203
 204                                 return;
 205                         }
 206
 207                         Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 208                         // Open a new connection (well, check that it's a SYN)
 209                         if(hdr->Flags != TCP_FLAG_SYN) {
 210                                 Log_Log("TCP", "TCP_GetPacket: Packet is not a SYN");
 211                                 return ;
 212                         }
 213
 214                         // TODO: Check for halfopen max
 215
 216                         conn = calloc(1, sizeof(tTCPConnection));
 217                         conn->State = TCP_ST_SYN_RCVD;
 218                         conn->LocalPort = srv->Port;
 219                         conn->RemotePort = ntohs(hdr->SourcePort);
 220                         conn->Interface = Interface;
 221
 222                         switch(Interface->Type)
 223                         {
 224                         case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 225                         case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 226                         }
 227
 228                         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 229
 230                         conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 231                         conn->NextSequenceSend = rand();
 232
 233                         // Create node
 234                         conn->Node.NumACLs = 1;
 235                         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 236                         conn->Node.ImplPtr = conn;
 237                         conn->Node.ImplInt = srv->NextID ++;
 238                         conn->Node.Read = TCP_Client_Read;
 239                         conn->Node.Write = TCP_Client_Write;
 240                         //conn->Node.Close = TCP_SrvConn_Close;
 241
 242                         // Hmm... Theoretically, this lock will never have to wait,
 243                         // as the interface is locked to the watching thread, and this
 244                         // runs in the watching thread. But, it's a good idea to have
 245                         // it, just in case
 246                         // Oh, wait, there is a case where a wildcard can be used
 247                         // (srv->Interface == NULL) so having the lock is a good idea
 248                         SHORTLOCK(&srv->lConnections);
 249                         if( !srv->Connections )
 250                                 srv->Connections = conn;
 251                         else
 252                                 srv->ConnectionsTail->Next = conn;
 253                         srv->ConnectionsTail = conn;
 254                         if(!srv->NewConnections)
 255                                 srv->NewConnections = conn;
 256                         SHORTREL(&srv->lConnections);
 257
 258                         // Send the SYN ACK
 259                         hdr->Flags |= TCP_FLAG_ACK;
 260                         hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 261                         hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 262                         hdr->DestPort = hdr->SourcePort;
 263                         hdr->SourcePort = htons(srv->Port);
 264                         hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 265                         TCP_SendPacket( conn, sizeof(tTCPHeader), hdr );
 266                         conn->NextSequenceSend ++;
 267                         return ;
 268                 }
 269         }
 270
 271
 272         // Check Open Connections
 273         {
 274                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 275                 {
 276                         // Check that it is coming in on the same interface
 277                         if(conn->Interface != Interface)        continue;
 278
 279                         // Check Source Port
 280                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 281
 282                         // Check Source IP
 283                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 284                                 continue;
 285                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 286                                 continue;
 287
 288                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 289                         return ;
 290                 }
 291         }
 292
 293         Log_Log("TCP", "TCP_GetPacket: No Match");
 294 }
 295
 296 /**
 297  * \brief Handles a packet sent to a specific connection
 298  * \param Connection    TCP Connection pointer
 299  * \param Header        TCP Packet pointer
 300  * \param Length        Length of the packet
 301  */
 302 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 303 {
 304          int    dataLen;
 305         Uint32  sequence_num;
 306
 307         // Silently drop once finished
 308         // TODO: Check if this needs to be here
 309         if( Connection->State == TCP_ST_FINISHED ) {
 310                 Log_Log("TCP", "Packet ignored - connection finnished");
 311                 return ;
 312         }
 313
 314         // Syncronise sequence values
 315         if(Header->Flags & TCP_FLAG_SYN) {
 316                 // TODO: What if the packet also has data?
 317                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
 318         }
 319
 320         // Ackowledge a sent packet
 321         if(Header->Flags & TCP_FLAG_ACK) {
 322                 // TODO: Process an ACKed Packet
 323                 Log_Log("TCP", "Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 324         }
 325
 326         // Get length of data
 327         dataLen = Length - (Header->DataOffset>>4)*4;
 328         Log_Log("TCP", "HandleConnectionPacket - dataLen = %i", dataLen);
 329
 330         //
 331         // State Machine
 332         //
 333         switch( Connection->State )
 334         {
 335         // Pre-init connection?
 336         case TCP_ST_CLOSED:
 337                 Log_Log("TCP", "Packets to a closed connection?!");
 338                 break;
 339
 340         // --- Init States ---
 341         // SYN sent, expecting SYN-ACK Connection Opening
 342         case TCP_ST_SYN_SENT:
 343                 if( Header->Flags & TCP_FLAG_SYN )
 344                 {
 345                         Connection->NextSequenceRcv ++;
 346                         Header->DestPort = Header->SourcePort;
 347                         Header->SourcePort = htons(Connection->LocalPort);
 348                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 349                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 350                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 351                         Header->Flags = TCP_FLAG_ACK;
 352                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 353                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 354
 355                         if( Header->Flags & TCP_FLAG_ACK )
 356                         {
 357                                 Log_Log("TCP", "ACKing SYN-ACK");
 358                                 Connection->State = TCP_ST_OPEN;
 359                         }
 360                         else
 361                         {
 362                                 Log_Log("TCP", "ACKing SYN");
 363                                 Connection->State = TCP_ST_SYN_RCVD;
 364                         }
 365                 }
 366                 break;
 367
 368         // SYN-ACK sent, expecting ACK
 369         case TCP_ST_SYN_RCVD:
 370                 if( Header->Flags & TCP_FLAG_ACK )
 371                 {
 372                         // TODO: Handle max half-open limit
 373                         Connection->State = TCP_ST_OPEN;
 374                         Log_Log("TCP", "Connection fully opened");
 375                 }
 376                 break;
 377
 378         // --- Established State ---
 379         case TCP_ST_OPEN:
 380                 // - Handle State changes
 381                 //
 382                 if( Header->Flags & TCP_FLAG_FIN ) {
 383                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
 384                         VFS_MarkError(&Connection->Node, 1);
 385                         Connection->State = TCP_ST_CLOSE_WAIT;
 386 //                      Header->Flags &= ~TCP_FLAG_FIN;
 387                         // CLOSE WAIT requires the client to close (or does it?)
 388                         #if 0
 389
 390                         #endif
 391                 }
 392
 393                 // Check for an empty packet
 394                 if(dataLen == 0) {
 395                         if( Header->Flags == TCP_FLAG_ACK )
 396                         {
 397                                 Log_Log("TCP", "ACK only packet");
 398                                 return ;
 399                         }
 400                         Connection->NextSequenceRcv ++; // TODO: Is this right? (empty packet counts as one byte)
 401                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
 402                         Header->DestPort = Header->SourcePort;
 403                         Header->SourcePort = htons(Connection->LocalPort);
 404                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 405                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 406                         Header->Flags |= TCP_FLAG_ACK;
 407                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 408                         return ;
 409                 }
 410
 411                 // NOTES:
 412                 // Flags
 413                 //    PSH - Has Data?
 414                 // /NOTES
 415
 416                 sequence_num = ntohl(Header->SequenceNumber);
 417
 418                 Log_Log("TCP", "0x%08x <= 0x%08x < 0x%08x",
 419                         Connection->NextSequenceRcv,
 420                         ntohl(Header->SequenceNumber),
 421                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
 422                         );
 423
 424                 // Is this packet the next expected packet?
 425                 if( sequence_num == Connection->NextSequenceRcv )
 426                 {
 427                          int    rv;
 428                         // Ooh, Goodie! Add it to the recieved list
 429                         rv = TCP_INT_AppendRecieved(Connection,
 430                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 431                                 dataLen
 432                                 );
 433                         if(rv != 0) {
 434                                 break;
 435                         }
 436                         Log_Log("TCP", "0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 437                         Connection->NextSequenceRcv += dataLen;
 438
 439                         // TODO: This should be moved out of the watcher thread,
 440                         // so that a single lost packet on one connection doesn't cause
 441                         // all connections on the interface to lag.
 442                         // - Meh, no real issue, as the cache shouldn't be that large
 443                         TCP_INT_UpdateRecievedFromFuture(Connection);
 444
 445                         // ACK Packet
 446                         Header->DestPort = Header->SourcePort;
 447                         Header->SourcePort = htons(Connection->LocalPort);
 448                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 449                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 450                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 451                         Header->Flags &= TCP_FLAG_SYN;  // Eliminate all flags save for SYN
 452                         Header->Flags |= TCP_FLAG_ACK;  // Add ACK
 453                         Log_Log("TCP", "Sending ACK for 0x%08x", Connection->NextSequenceRcv);
 454                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 455                         //Connection->NextSequenceSend ++;
 456                 }
 457                 // Check if the packet is in window
 458                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 459                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 460                 {
 461                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 462                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 463                         Uint32  index;
 464                          int    i;
 465
 466                         index = sequence_num % TCP_WINDOW_SIZE;
 467                         for( i = 0; i < dataLen; i ++ )
 468                         {
 469                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
 470                                 Connection->FuturePacketData[index] = dataptr[i];
 471                                 // Do a wrap increment
 472                                 index ++;
 473                                 if(index == TCP_WINDOW_SIZE)    index = 0;
 474                         }
 475                         #else
 476                         tTCPStoredPacket        *pkt, *tmp, *prev = NULL;
 477
 478                         // Allocate and fill cached packet
 479                         pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
 480                         pkt->Next = NULL;
 481                         pkt->Sequence = ntohl(Header->SequenceNumber);
 482                         pkt->Length = dataLen;
 483                         memcpy(pkt->Data, dataptr, dataLen);
 484
 485                         Log_Log("TCP", "We missed a packet, caching",
 486                                 pkt->Sequence, Connection->NextSequenceRcv);
 487
 488                         // No? Well, let's cache it and look at it later
 489                         SHORTLOCK( &Connection->lFuturePackets );
 490                         for(tmp = Connection->FuturePackets;
 491                                 tmp;
 492                                 prev = tmp, tmp = tmp->Next)
 493                         {
 494                                 if(tmp->Sequence >= pkt->Sequence)      break;
 495                         }
 496
 497                         // Add if before first, or sequences don't match
 498                         if( !tmp || tmp->Sequence != pkt->Sequence )
 499                         {
 500                                 if(prev)
 501                                         prev->Next = pkt;
 502                                 else
 503                                         Connection->FuturePackets = pkt;
 504                                 pkt->Next = tmp;
 505                         }
 506                         // Replace if larger
 507                         else if(pkt->Length > tmp->Length)
 508                         {
 509                                 if(prev)
 510                                         prev->Next = pkt;
 511                                 pkt->Next = tmp->Next;
 512                                 free(tmp);
 513                         }
 514                         else
 515                         {
 516                                 free(pkt);      // TODO: Find some way to remove this
 517                         }
 518                         SHORTREL( &Connection->lFuturePackets );
 519                         #endif
 520                 }
 521                 // Badly out of sequence packet
 522                 else
 523                 {
 524                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
 525                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
 526                         // TODO: Spec says we should send an empty ACK with the current state
 527                 }
 528                 break;
 529
 530         // --- Remote close states
 531         case TCP_ST_CLOSE_WAIT:
 532
 533                 // Ignore everything, CLOSE_WAIT is terminated by the client
 534                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
 535
 536                 break;
 537
 538         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
 539         case TCP_ST_LAST_ACK:
 540                 if( Header->Flags & TCP_FLAG_ACK )
 541                 {
 542                         Connection->State = TCP_ST_FINISHED;    // Connection completed
 543                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
 544                         // TODO: Destrory the TCB
 545                 }
 546                 break;
 547
 548         // --- Local close States
 549         case TCP_ST_FIN_WAIT1:
 550                 if( Header->Flags & TCP_FLAG_FIN )
 551                 {
 552                         Connection->State = TCP_ST_CLOSING;
 553                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
 554                         VFS_MarkError(&Connection->Node, 1);
 555
 556                         // ACK Packet
 557                         Header->DestPort = Header->SourcePort;
 558                         Header->SourcePort = htons(Connection->LocalPort);
 559                         Header->AcknowlegementNumber = Header->SequenceNumber;
 560                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 561                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 562                         Header->Flags = TCP_FLAG_ACK;
 563                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 564                         break ;
 565                 }
 566
 567                 // TODO: Make sure that the packet is actually ACKing the FIN
 568                 if( Header->Flags & TCP_FLAG_ACK )
 569                 {
 570                         Connection->State = TCP_ST_FIN_WAIT2;
 571                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
 572                         VFS_MarkError(&Connection->Node, 1);
 573                         return ;
 574                 }
 575                 break;
 576
 577         case TCP_ST_FIN_WAIT2:
 578                 if( Header->Flags & TCP_FLAG_FIN )
 579                 {
 580                         Connection->State = TCP_ST_TIME_WAIT;
 581                         Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
 582                         // Send ACK
 583                         Header->DestPort = Header->SourcePort;
 584                         Header->SourcePort = htons(Connection->LocalPort);
 585                         Header->AcknowlegementNumber = Header->SequenceNumber;
 586                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 587                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 588                         Header->Flags = TCP_FLAG_ACK;
 589                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 590                 }
 591                 break;
 592
 593         case TCP_ST_CLOSING:
 594                 // TODO: Make sure that the packet is actually ACKing the FIN
 595                 if( Header->Flags & TCP_FLAG_ACK )
 596                 {
 597                         Connection->State = TCP_ST_TIME_WAIT;
 598                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
 599                         VFS_MarkError(&Connection->Node, 1);
 600                         return ;
 601                 }
 602                 break;
 603
 604         // --- Closed (or near closed) states) ---
 605         case TCP_ST_TIME_WAIT:
 606                 Log_Log("TCP", "Packets on Time-Wait, ignored");
 607                 break;
 608
 609         case TCP_ST_FINISHED:
 610                 Log_Log("TCP", "Packets when CLOSED, ignoring");
 611                 break;
 612
 613         //default:
 614         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
 615         //      break;
 616         }
 617
 618 }
 619
 620 /**
 621  * \brief Appends a packet to the recieved list
 622  * \param Connection    Connection structure
 623  * \param Data  Packet contents
 624  * \param Length        Length of \a Data
 625  */
 626 int TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
 627 {
 628         Mutex_Acquire( &Connection->lRecievedPackets );
 629
 630         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
 631         {
 632                 VFS_MarkAvaliable(&Connection->Node, 1);
 633                 Log_Error("TCP", "Buffer filled, packet dropped (:%i) - %i + %i > %i",
 634                         Connection->LocalPort, Connection->RecievedBuffer->Length, Length,
 635                         Connection->RecievedBuffer->Space
 636                         );
 637                 Mutex_Release( &Connection->lRecievedPackets );
 638                 return 1;
 639         }
 640
 641         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
 642
 643         VFS_MarkAvaliable(&Connection->Node, 1);
 644
 645         Mutex_Release( &Connection->lRecievedPackets );
 646         return 0;
 647 }
 648
 649 /**
 650  * \brief Updates the connections recieved list from the future list
 651  * \param Connection    Connection structure
 652  *
 653  * Updates the recieved packets list with packets from the future (out
 654  * of order) packets list that are now able to be added in direct
 655  * sequence.
 656  */
 657 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 658 {
 659         #if CACHE_FUTURE_PACKETS_IN_BYTES
 660          int    i, length = 0;
 661         Uint32  index;
 662
 663         // Calculate length of contiguous bytes
 664         length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 665         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 666         for( i = 0; i < length; i ++ )
 667         {
 668                 if( Connection->FuturePacketValidBytes[i / 8] == 0xFF ) {
 669                         i += 7; index += 7;
 670                         continue;
 671                 }
 672                 else if( !(Connection->FuturePacketValidBytes[i / 8] & (1 << (i%8))) )
 673                         break;
 674
 675                 index ++;
 676                 if(index > TCP_WINDOW_SIZE)
 677                         index -= TCP_WINDOW_SIZE;
 678         }
 679         length = i;
 680
 681         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 682
 683         // Write data to to the ring buffer
 684         if( TCP_WINDOW_SIZE - index > length )
 685         {
 686                 // Simple case
 687                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 688         }
 689         else
 690         {
 691                  int    endLen = TCP_WINDOW_SIZE - index;
 692                 // 2-part case
 693                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 694                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 695         }
 696
 697         // Mark (now saved) bytes as invalid
 698         // - Align index
 699         while(index % 8 && length)
 700         {
 701                 Connection->FuturePacketData[index] = 0;
 702                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 703                 index ++;
 704                 if(index > TCP_WINDOW_SIZE)
 705                         index -= TCP_WINDOW_SIZE;
 706                 length --;
 707         }
 708         while( length > 7 )
 709         {
 710                 Connection->FuturePacketData[index] = 0;
 711                 Connection->FuturePacketValidBytes[index/8] = 0;
 712                 length -= 8;
 713                 index += 8;
 714                 if(index > TCP_WINDOW_SIZE)
 715                         index -= TCP_WINDOW_SIZE;
 716         }
 717         while(length)
 718         {
 719                 Connection->FuturePacketData[index] = 0;
 720                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 721                 index ++;
 722                 if(index > TCP_WINDOW_SIZE)
 723                         index -= TCP_WINDOW_SIZE;
 724                 length --;
 725         }
 726
 727         #else
 728         tTCPStoredPacket        *pkt;
 729         for(;;)
 730         {
 731                 SHORTLOCK( &Connection->lFuturePackets );
 732
 733                 // Clear out duplicates from cache
 734                 // - If a packet has just been recieved, and it is expected, then
 735                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 736                 //   packets in cache that are smaller than the next expected
 737                 //   are now defunct.
 738                 pkt = Connection->FuturePackets;
 739                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 740                 {
 741                         tTCPStoredPacket        *next = pkt->Next;
 742                         free(pkt);
 743                         pkt = next;
 744                 }
 745
 746                 // If there's no packets left in cache, stop looking
 747                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 748                         SHORTREL( &Connection->lFuturePackets );
 749                         return;
 750                 }
 751
 752                 // Delete packet from future list
 753                 Connection->FuturePackets = pkt->Next;
 754
 755                 // Release list
 756                 SHORTREL( &Connection->lFuturePackets );
 757
 758                 // Looks like we found one
 759                 TCP_INT_AppendRecieved(Connection, pkt);
 760                 Connection->NextSequenceRcv += pkt->Length;
 761                 free(pkt);
 762         }
 763         #endif
 764 }
 765
 766 /**
 767  * \fn Uint16 TCP_GetUnusedPort()
 768  * \brief Gets an unused port and allocates it
 769  */
 770 Uint16 TCP_GetUnusedPort()
 771 {
 772         Uint16  ret;
 773
 774         // Get Next outbound port
 775         ret = giTCP_NextOutPort++;
 776         while( gaTCP_PortBitmap[ret/32] & (1 << (ret%32)) )
 777         {
 778                 ret ++;
 779                 giTCP_NextOutPort++;
 780                 if(giTCP_NextOutPort == 0x10000) {
 781                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 782                 }
 783         }
 784
 785         // Mark the new port as used
 786         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 787
 788         return ret;
 789 }
 790
 791 /**
 792  * \fn int TCP_AllocatePort(Uint16 Port)
 793  * \brief Marks a port as used
 794  */
 795 int TCP_AllocatePort(Uint16 Port)
 796 {
 797         // Check if the port has already been allocated
 798         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 799                 return 0;
 800
 801         // Allocate
 802         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 803
 804         return 1;
 805 }
 806
 807 /**
 808  * \fn int TCP_DeallocatePort(Uint16 Port)
 809  * \brief Marks a port as unused
 810  */
 811 int TCP_DeallocatePort(Uint16 Port)
 812 {
 813         // Check if the port has already been allocated
 814         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 815                 return 0;
 816
 817         // Allocate
 818         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 819
 820         return 1;
 821 }
 822
 823 // --- Server
 824 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 825 {
 826         tTCPListener    *srv;
 827
 828         srv = malloc( sizeof(tTCPListener) );
 829
 830         if( srv == NULL ) {
 831                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 832                 return NULL;
 833         }
 834
 835         srv->Interface = Interface;
 836         srv->Port = 0;
 837         srv->NextID = 0;
 838         srv->Connections = NULL;
 839         srv->ConnectionsTail = NULL;
 840         srv->NewConnections = NULL;
 841         srv->Next = NULL;
 842         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 843         srv->Node.Size = -1;
 844         srv->Node.ImplPtr = srv;
 845         srv->Node.NumACLs = 1;
 846         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 847         srv->Node.ReadDir = TCP_Server_ReadDir;
 848         srv->Node.FindDir = TCP_Server_FindDir;
 849         srv->Node.IOCtl = TCP_Server_IOCtl;
 850         srv->Node.Close = TCP_Server_Close;
 851
 852         SHORTLOCK(&glTCP_Listeners);
 853         srv->Next = gTCP_Listeners;
 854         gTCP_Listeners = srv;
 855         SHORTREL(&glTCP_Listeners);
 856
 857         return &srv->Node;
 858 }
 859
 860 /**
 861  * \brief Wait for a new connection and return the connection ID
 862  * \note Blocks until a new connection is made
 863  * \param Node  Server node
 864  * \param Pos   Position (ignored)
 865  */
 866 char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
 867 {
 868         tTCPListener    *srv = Node->ImplPtr;
 869         tTCPConnection  *conn;
 870         char    *ret;
 871
 872         ENTER("pNode iPos", Node, Pos);
 873
 874         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 875         for(;;)
 876         {
 877                 SHORTLOCK( &srv->lConnections );
 878                 if( srv->NewConnections != NULL )       break;
 879                 SHORTREL( &srv->lConnections );
 880                 Threads_Yield();        // TODO: Sleep until poked
 881                 continue;
 882         }
 883
 884
 885         // Increment the new list (the current connection is still on the
 886         // normal list)
 887         conn = srv->NewConnections;
 888         srv->NewConnections = conn->Next;
 889
 890         SHORTREL( &srv->lConnections );
 891
 892         LOG("conn = %p", conn);
 893         LOG("srv->Connections = %p", srv->Connections);
 894         LOG("srv->NewConnections = %p", srv->NewConnections);
 895         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 896
 897         ret = malloc(9);
 898         itoa(ret, conn->Node.ImplInt, 16, 8, '0');
 899         Log_Log("TCP", "Thread %i got '%s'", Threads_GetTID(), ret);
 900         LEAVE('s', ret);
 901         return ret;
 902 }
 903
 904 /**
 905  * \brief Gets a client connection node
 906  * \param Node  Server node
 907  * \param Name  Hexadecimal ID of the node
 908  */
 909 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name)
 910 {
 911         tTCPConnection  *conn;
 912         tTCPListener    *srv = Node->ImplPtr;
 913         char    tmp[9];
 914          int    id = atoi(Name);
 915
 916         ENTER("pNode sName", Node, Name);
 917
 918         // Sanity Check
 919         itoa(tmp, id, 16, 8, '0');
 920         if(strcmp(tmp, Name) != 0) {
 921                 LOG("'%s' != '%s' (%08x)", Name, tmp, id);
 922                 LEAVE('n');
 923                 return NULL;
 924         }
 925
 926         Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
 927         Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
 928         Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 929
 930         // Search
 931         SHORTLOCK( &srv->lConnections );
 932         for(conn = srv->Connections;
 933                 conn;
 934                 conn = conn->Next)
 935         {
 936                 LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
 937                 if(conn->Node.ImplInt == id)    break;
 938         }
 939         SHORTREL( &srv->lConnections );
 940
 941         // If not found, ret NULL
 942         if(!conn) {
 943                 LOG("Connection %i not found", id);
 944                 LEAVE('n');
 945                 return NULL;
 946         }
 947
 948         // Return node
 949         LEAVE('p', &conn->Node);
 950         return &conn->Node;
 951 }
 952
 953 /**
 954  * \brief Handle IOCtl calls
 955  */
 956 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
 957 {
 958         tTCPListener    *srv = Node->ImplPtr;
 959
 960         switch(ID)
 961         {
 962         case 4: // Get/Set Port
 963                 if(!Data)       // Get Port
 964                         return srv->Port;
 965
 966                 if(srv->Port)   // Wait, you can't CHANGE the port
 967                         return -1;
 968
 969                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
 970                         return -1;
 971
 972                 // Permissions check
 973                 if(Threads_GetUID() != 0
 974                 && *(Uint16*)Data != 0
 975                 && *(Uint16*)Data < 1024)
 976                         return -1;
 977
 978                 // TODO: Check if a port is in use
 979
 980                 // Set Port
 981                 srv->Port = *(Uint16*)Data;
 982                 if(srv->Port == 0)      // Allocate a random port
 983                         srv->Port = TCP_GetUnusedPort();
 984                 else    // Else, mark this as used
 985                         TCP_AllocatePort(srv->Port);
 986
 987                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
 988
 989                 return srv->Port;
 990         }
 991         return 0;
 992 }
 993
 994 void TCP_Server_Close(tVFS_Node *Node)
 995 {
 996         free(Node->ImplPtr);
 997 }
 998
 999 // --- Client
1000 /**
1001  * \brief Create a client node
1002  */
1003 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1004 {
1005         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
1006
1007         conn->State = TCP_ST_CLOSED;
1008         conn->Interface = Interface;
1009         conn->LocalPort = -1;
1010         conn->RemotePort = -1;
1011
1012         conn->Node.ImplPtr = conn;
1013         conn->Node.NumACLs = 1;
1014         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
1015         conn->Node.Read = TCP_Client_Read;
1016         conn->Node.Write = TCP_Client_Write;
1017         conn->Node.IOCtl = TCP_Client_IOCtl;
1018         conn->Node.Close = TCP_Client_Close;
1019
1020         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
1021         #if 0
1022         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
1023         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
1024         #endif
1025
1026         #if CACHE_FUTURE_PACKETS_IN_BYTES
1027         // Future recieved data (ahead of the expected sequence number)
1028         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
1029         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
1030         #endif
1031
1032         SHORTLOCK(&glTCP_OutbountCons);
1033         conn->Next = gTCP_OutbountCons;
1034         gTCP_OutbountCons = conn;
1035         SHORTREL(&glTCP_OutbountCons);
1036
1037         return &conn->Node;
1038 }
1039
1040 /**
1041  * \brief Wait for a packet and return it
1042  * \note If \a Length is smaller than the size of the packet, the rest
1043  *       of the packet's data will be discarded.
1044  */
1045 Uint64 TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
1046 {
1047         tTCPConnection  *conn = Node->ImplPtr;
1048         size_t  len;
1049
1050         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1051         LOG("conn = %p {State:%i}", conn, conn->State);
1052
1053         // Check if connection is estabilishing
1054         // - TODO: Sleep instead (maybe using VFS_SelectNode to wait for the
1055         //   data to be availiable
1056         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1057                 Threads_Yield();
1058
1059         // If the conneciton is not open, then clean out the recieved buffer
1060         if( conn->State != TCP_ST_OPEN )
1061         {
1062                 Mutex_Acquire( &conn->lRecievedPackets );
1063                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1064                 Mutex_Release( &conn->lRecievedPackets );
1065
1066                 if( len == 0 ) {
1067                         VFS_MarkAvaliable(Node, 0);
1068                         LEAVE('i', -1);
1069                         return -1;
1070                 }
1071
1072                 LEAVE('i', len);
1073                 return len;
1074         }
1075
1076         // Wait
1077         VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, NULL, "TCP_Client_Read");
1078
1079         // Lock list and read as much as possible (up to `Length`)
1080         Mutex_Acquire( &conn->lRecievedPackets );
1081         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1082
1083         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1084                 LOG("Marking as none avaliable (len = %i)", len);
1085                 VFS_MarkAvaliable(Node, 0);
1086         }
1087
1088         // Release the lock (we don't need it any more)
1089         Mutex_Release( &conn->lRecievedPackets );
1090
1091         LEAVE('i', len);
1092         return len;
1093 }
1094
1095 /**
1096  * \brief Send a data packet on a connection
1097  */
1098 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, void *Data)
1099 {
1100         char    buf[sizeof(tTCPHeader)+Length];
1101         tTCPHeader      *packet = (void*)buf;
1102
1103         packet->SourcePort = htons(Connection->LocalPort);
1104         packet->DestPort = htons(Connection->RemotePort);
1105         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1106         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1107
1108         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1109         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1110         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1111
1112         memcpy(packet->Options, Data, Length);
1113
1114         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1115 #if HEXDUMP_OUTGOING
1116         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1117 #endif
1118
1119         TCP_SendPacket( Connection, sizeof(tTCPHeader)+Length, packet );
1120
1121         Connection->NextSequenceSend += Length;
1122 }
1123
1124 /**
1125  * \brief Send some bytes on a connection
1126  */
1127 Uint64 TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
1128 {
1129         tTCPConnection  *conn = Node->ImplPtr;
1130         size_t  rem = Length;
1131
1132         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1133
1134 //      #if DEBUG
1135 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1136 //              Buffer, Length);
1137 //      #endif
1138
1139         // Check if connection is open
1140         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1141                 Threads_Yield();
1142
1143         if( conn->State != TCP_ST_OPEN ) {
1144                 VFS_MarkError(Node, 1);
1145                 LEAVE('i', -1);
1146                 return -1;
1147         }
1148
1149         do
1150         {
1151                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1152
1153                 #if 0
1154                 // Wait for space in the buffer
1155                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1156
1157                 // Save data to buffer (and update the length read by the ammount written)
1158                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1159                 #endif
1160
1161                 // Send packet
1162                 TCP_INT_SendDataPacket(conn, len, Buffer);
1163
1164                 Buffer += len;
1165                 rem -= len;
1166         } while( rem > 0 );
1167
1168         LEAVE('i', Length);
1169         return Length;
1170 }
1171
1172 /**
1173  * \brief Open a connection to another host using TCP
1174  * \param Conn  Connection structure
1175  */
1176 void TCP_StartConnection(tTCPConnection *Conn)
1177 {
1178         tTCPHeader      hdr = {0};
1179
1180         Conn->State = TCP_ST_SYN_SENT;
1181
1182         hdr.SourcePort = htons(Conn->LocalPort);
1183         hdr.DestPort = htons(Conn->RemotePort);
1184         Conn->NextSequenceSend = rand();
1185         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1186         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1187         hdr.Flags = TCP_FLAG_SYN;
1188         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1189         hdr.Checksum = 0;       // TODO
1190
1191         TCP_SendPacket( Conn, sizeof(tTCPHeader), &hdr );
1192
1193         Conn->NextSequenceSend ++;
1194         Conn->State = TCP_ST_SYN_SENT;
1195
1196         return ;
1197 }
1198
1199 /**
1200  * \brief Control a client socket
1201  */
1202 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1203 {
1204         tTCPConnection  *conn = Node->ImplPtr;
1205
1206         ENTER("pNode iID pData", Node, ID, Data);
1207
1208         switch(ID)
1209         {
1210         case 4: // Get/Set local port
1211                 if(!Data)
1212                         LEAVE_RET('i', conn->LocalPort);
1213                 if(conn->State != TCP_ST_CLOSED)
1214                         LEAVE_RET('i', -1);
1215                 if(!CheckMem(Data, sizeof(Uint16)))
1216                         LEAVE_RET('i', -1);
1217
1218                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1219                         LEAVE_RET('i', -1);
1220
1221                 conn->LocalPort = *(Uint16*)Data;
1222                 LEAVE_RET('i', conn->LocalPort);
1223
1224         case 5: // Get/Set remote port
1225                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1226                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1227                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1228                 conn->RemotePort = *(Uint16*)Data;
1229                 LEAVE_RET('i', conn->RemotePort);
1230
1231         case 6: // Set Remote IP
1232                 if( conn->State != TCP_ST_CLOSED )
1233                         LEAVE_RET('i', -1);
1234                 if( conn->Interface->Type == 4 )
1235                 {
1236                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1237                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1238                 }
1239                 else if( conn->Interface->Type == 6 )
1240                 {
1241                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1242                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1243                 }
1244                 LEAVE_RET('i', 0);
1245
1246         case 7: // Connect
1247                 if(conn->LocalPort == 0xFFFF)
1248                         conn->LocalPort = TCP_GetUnusedPort();
1249                 if(conn->RemotePort == -1)
1250                         LEAVE_RET('i', 0);
1251
1252                 {
1253                         tTime   timeout_end = now() + conn->Interface->TimeoutDelay;
1254
1255                         TCP_StartConnection(conn);
1256                         // TODO: Wait for connection to open
1257                         while( conn->State == TCP_ST_SYN_SENT && timeout_end > now() ) {
1258                                 Threads_Yield();
1259                         }
1260                         if( conn->State == TCP_ST_SYN_SENT )
1261                                 LEAVE_RET('i', 0);
1262                 }
1263
1264                 LEAVE_RET('i', 1);
1265
1266         // Get recieve buffer length
1267         case 8:
1268                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1269         }
1270
1271         return 0;
1272 }
1273
1274 void TCP_Client_Close(tVFS_Node *Node)
1275 {
1276         tTCPConnection  *conn = Node->ImplPtr;
1277         tTCPHeader      packet;
1278
1279         ENTER("pNode", Node);
1280
1281         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1282         {
1283                 packet.SourcePort = htons(conn->LocalPort);
1284                 packet.DestPort = htons(conn->RemotePort);
1285                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1286                 packet.WindowSize = TCP_WINDOW_SIZE;
1287
1288                 packet.AcknowlegementNumber = 0;
1289                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1290                 packet.Flags = TCP_FLAG_FIN;
1291
1292                 TCP_SendPacket( conn, sizeof(tTCPHeader), &packet );
1293         }
1294
1295         switch( conn->State )
1296         {
1297         case TCP_ST_CLOSE_WAIT:
1298                 conn->State = TCP_ST_LAST_ACK;
1299                 break;
1300         case TCP_ST_OPEN:
1301                 conn->State = TCP_ST_FIN_WAIT1;
1302                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1303                 break;
1304         default:
1305                 Log_Warning("TCP", "Unhandled connection state in TCP_Client_Close");
1306                 break;
1307         }
1308
1309         free(conn);
1310
1311         LEAVE('-');
1312 }
1313
1314 /**
1315  * \brief Checks if a value is between two others (after taking into account wrapping)
1316  */
1317 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1318 {
1319         if( MaxValue < 0xFFFFFFFF )
1320         {
1321                 Lower %= MaxValue + 1;
1322                 Value %= MaxValue + 1;
1323                 Higher %= MaxValue + 1;
1324         }
1325
1326         // Simple Case, no wrap ?
1327         //       Lower Value Higher
1328         // | ... + ... + ... + ... |
1329
1330         if( Lower < Higher ) {
1331                 return Lower < Value && Value < Higher;
1332         }
1333         // Higher has wrapped below lower
1334
1335         // Value > Lower ?
1336         //       Higher Lower Value
1337         // | ... +  ... + ... + ... |
1338         if( Value > Lower ) {
1339                 return 1;
1340         }
1341
1342         // Value < Higher ?
1343         //       Value Higher Lower
1344         // | ... + ... +  ... + ... |
1345         if( Value < Higher ) {
1346                 return 1;
1347         }
1348
1349         return 0;
1350 }