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 void    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                         // Ooh, Goodie! Add it to the recieved list
 428                         TCP_INT_AppendRecieved(Connection,
 429                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 430                                 dataLen
 431                                 );
 432                         Log_Log("TCP", "0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 433                         Connection->NextSequenceRcv += dataLen;
 434
 435                         // TODO: This should be moved out of the watcher thread,
 436                         // so that a single lost packet on one connection doesn't cause
 437                         // all connections on the interface to lag.
 438                         // - Meh, no real issue, as the cache shouldn't be that large
 439                         TCP_INT_UpdateRecievedFromFuture(Connection);
 440
 441                         // ACK Packet
 442                         Header->DestPort = Header->SourcePort;
 443                         Header->SourcePort = htons(Connection->LocalPort);
 444                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 445                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 446                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 447                         Header->Flags &= TCP_FLAG_SYN;  // Eliminate all flags save for SYN
 448                         Header->Flags |= TCP_FLAG_ACK;  // Add ACK
 449                         Log_Log("TCP", "Sending ACK for 0x%08x", Connection->NextSequenceRcv);
 450                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 451                         //Connection->NextSequenceSend ++;
 452                 }
 453                 // Check if the packet is in window
 454                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 455                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 456                 {
 457                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 458                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 459                         Uint32  index;
 460                          int    i;
 461
 462                         index = sequence_num % TCP_WINDOW_SIZE;
 463                         for( i = 0; i < dataLen; i ++ )
 464                         {
 465                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
 466                                 Connection->FuturePacketData[index] = dataptr[i];
 467                                 // Do a wrap increment
 468                                 index ++;
 469                                 if(index == TCP_WINDOW_SIZE)    index = 0;
 470                         }
 471                         #else
 472                         tTCPStoredPacket        *pkt, *tmp, *prev = NULL;
 473
 474                         // Allocate and fill cached packet
 475                         pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
 476                         pkt->Next = NULL;
 477                         pkt->Sequence = ntohl(Header->SequenceNumber);
 478                         pkt->Length = dataLen;
 479                         memcpy(pkt->Data, dataptr, dataLen);
 480
 481                         Log_Log("TCP", "We missed a packet, caching",
 482                                 pkt->Sequence, Connection->NextSequenceRcv);
 483
 484                         // No? Well, let's cache it and look at it later
 485                         SHORTLOCK( &Connection->lFuturePackets );
 486                         for(tmp = Connection->FuturePackets;
 487                                 tmp;
 488                                 prev = tmp, tmp = tmp->Next)
 489                         {
 490                                 if(tmp->Sequence >= pkt->Sequence)      break;
 491                         }
 492
 493                         // Add if before first, or sequences don't match
 494                         if( !tmp || tmp->Sequence != pkt->Sequence )
 495                         {
 496                                 if(prev)
 497                                         prev->Next = pkt;
 498                                 else
 499                                         Connection->FuturePackets = pkt;
 500                                 pkt->Next = tmp;
 501                         }
 502                         // Replace if larger
 503                         else if(pkt->Length > tmp->Length)
 504                         {
 505                                 if(prev)
 506                                         prev->Next = pkt;
 507                                 pkt->Next = tmp->Next;
 508                                 free(tmp);
 509                         }
 510                         else
 511                         {
 512                                 free(pkt);      // TODO: Find some way to remove this
 513                         }
 514                         SHORTREL( &Connection->lFuturePackets );
 515                         #endif
 516                 }
 517                 // Badly out of sequence packet
 518                 else
 519                 {
 520                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
 521                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
 522                         // TODO: Spec says we should send an empty ACK with the current state
 523                 }
 524                 break;
 525
 526         // --- Remote close states
 527         case TCP_ST_CLOSE_WAIT:
 528
 529                 // Ignore everything, CLOSE_WAIT is terminated by the client
 530                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
 531
 532                 break;
 533
 534         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
 535         case TCP_ST_LAST_ACK:
 536                 if( Header->Flags & TCP_FLAG_ACK )
 537                 {
 538                         Connection->State = TCP_ST_FINISHED;    // Connection completed
 539                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
 540                         // TODO: Destrory the TCB
 541                 }
 542                 break;
 543
 544         // --- Local close States
 545         case TCP_ST_FIN_WAIT1:
 546                 if( Header->Flags & TCP_FLAG_FIN )
 547                 {
 548                         Connection->State = TCP_ST_CLOSING;
 549                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
 550                         VFS_MarkError(&Connection->Node, 1);
 551
 552                         // ACK Packet
 553                         Header->DestPort = Header->SourcePort;
 554                         Header->SourcePort = htons(Connection->LocalPort);
 555                         Header->AcknowlegementNumber = Header->SequenceNumber;
 556                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 557                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 558                         Header->Flags = TCP_FLAG_ACK;
 559                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 560                         break ;
 561                 }
 562
 563                 // TODO: Make sure that the packet is actually ACKing the FIN
 564                 if( Header->Flags & TCP_FLAG_ACK )
 565                 {
 566                         Connection->State = TCP_ST_FIN_WAIT2;
 567                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
 568                         VFS_MarkError(&Connection->Node, 1);
 569                         return ;
 570                 }
 571                 break;
 572
 573         case TCP_ST_FIN_WAIT2:
 574                 if( Header->Flags & TCP_FLAG_FIN )
 575                 {
 576                         Connection->State = TCP_ST_TIME_WAIT;
 577                         Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
 578                         // Send ACK
 579                         Header->DestPort = Header->SourcePort;
 580                         Header->SourcePort = htons(Connection->LocalPort);
 581                         Header->AcknowlegementNumber = Header->SequenceNumber;
 582                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 583                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 584                         Header->Flags = TCP_FLAG_ACK;
 585                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 586                 }
 587                 break;
 588
 589         case TCP_ST_CLOSING:
 590                 // TODO: Make sure that the packet is actually ACKing the FIN
 591                 if( Header->Flags & TCP_FLAG_ACK )
 592                 {
 593                         Connection->State = TCP_ST_TIME_WAIT;
 594                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
 595                         VFS_MarkError(&Connection->Node, 1);
 596                         return ;
 597                 }
 598                 break;
 599
 600         // --- Closed (or near closed) states) ---
 601         case TCP_ST_TIME_WAIT:
 602                 Log_Log("TCP", "Packets on Time-Wait, ignored");
 603                 break;
 604
 605         case TCP_ST_FINISHED:
 606                 Log_Log("TCP", "Packets when CLOSED, ignoring");
 607                 break;
 608
 609         //default:
 610         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
 611         //      break;
 612         }
 613
 614 }
 615
 616 /**
 617  * \brief Appends a packet to the recieved list
 618  * \param Connection    Connection structure
 619  * \param Data  Packet contents
 620  * \param Length        Length of \a Data
 621  */
 622 void TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
 623 {
 624         Mutex_Acquire( &Connection->lRecievedPackets );
 625         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
 626         {
 627                 Log_Error("TCP", "Buffer filled, packet dropped (%s)",
 628                 //      TCP_INT_DumpConnection(Connection)
 629                         ""
 630                         );
 631                 return ;
 632         }
 633
 634         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
 635
 636         VFS_MarkAvaliable(&Connection->Node, 1);
 637
 638         Mutex_Release( &Connection->lRecievedPackets );
 639 }
 640
 641 /**
 642  * \brief Updates the connections recieved list from the future list
 643  * \param Connection    Connection structure
 644  *
 645  * Updates the recieved packets list with packets from the future (out
 646  * of order) packets list that are now able to be added in direct
 647  * sequence.
 648  */
 649 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 650 {
 651         #if CACHE_FUTURE_PACKETS_IN_BYTES
 652          int    i, length = 0;
 653         Uint32  index;
 654
 655         // Calculate length of contiguous bytes
 656         length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 657         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 658         for( i = 0; i < length; i ++ )
 659         {
 660                 if( Connection->FuturePacketValidBytes[i / 8] == 0xFF ) {
 661                         i += 7; index += 7;
 662                         continue;
 663                 }
 664                 else if( !(Connection->FuturePacketValidBytes[i / 8] & (1 << (i%8))) )
 665                         break;
 666
 667                 index ++;
 668                 if(index > TCP_WINDOW_SIZE)
 669                         index -= TCP_WINDOW_SIZE;
 670         }
 671         length = i;
 672
 673         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 674
 675         // Write data to to the ring buffer
 676         if( TCP_WINDOW_SIZE - index > length )
 677         {
 678                 // Simple case
 679                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 680         }
 681         else
 682         {
 683                  int    endLen = TCP_WINDOW_SIZE - index;
 684                 // 2-part case
 685                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 686                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 687         }
 688
 689         // Mark (now saved) bytes as invalid
 690         // - Align index
 691         while(index % 8 && length)
 692         {
 693                 Connection->FuturePacketData[index] = 0;
 694                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 695                 index ++;
 696                 if(index > TCP_WINDOW_SIZE)
 697                         index -= TCP_WINDOW_SIZE;
 698                 length --;
 699         }
 700         while( length > 7 )
 701         {
 702                 Connection->FuturePacketData[index] = 0;
 703                 Connection->FuturePacketValidBytes[index/8] = 0;
 704                 length -= 8;
 705                 index += 8;
 706                 if(index > TCP_WINDOW_SIZE)
 707                         index -= TCP_WINDOW_SIZE;
 708         }
 709         while(length)
 710         {
 711                 Connection->FuturePacketData[index] = 0;
 712                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 713                 index ++;
 714                 if(index > TCP_WINDOW_SIZE)
 715                         index -= TCP_WINDOW_SIZE;
 716                 length --;
 717         }
 718
 719         #else
 720         tTCPStoredPacket        *pkt;
 721         for(;;)
 722         {
 723                 SHORTLOCK( &Connection->lFuturePackets );
 724
 725                 // Clear out duplicates from cache
 726                 // - If a packet has just been recieved, and it is expected, then
 727                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 728                 //   packets in cache that are smaller than the next expected
 729                 //   are now defunct.
 730                 pkt = Connection->FuturePackets;
 731                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 732                 {
 733                         tTCPStoredPacket        *next = pkt->Next;
 734                         free(pkt);
 735                         pkt = next;
 736                 }
 737
 738                 // If there's no packets left in cache, stop looking
 739                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 740                         SHORTREL( &Connection->lFuturePackets );
 741                         return;
 742                 }
 743
 744                 // Delete packet from future list
 745                 Connection->FuturePackets = pkt->Next;
 746
 747                 // Release list
 748                 SHORTREL( &Connection->lFuturePackets );
 749
 750                 // Looks like we found one
 751                 TCP_INT_AppendRecieved(Connection, pkt);
 752                 Connection->NextSequenceRcv += pkt->Length;
 753                 free(pkt);
 754         }
 755         #endif
 756 }
 757
 758 /**
 759  * \fn Uint16 TCP_GetUnusedPort()
 760  * \brief Gets an unused port and allocates it
 761  */
 762 Uint16 TCP_GetUnusedPort()
 763 {
 764         Uint16  ret;
 765
 766         // Get Next outbound port
 767         ret = giTCP_NextOutPort++;
 768         while( gaTCP_PortBitmap[ret/32] & (1 << (ret%32)) )
 769         {
 770                 ret ++;
 771                 giTCP_NextOutPort++;
 772                 if(giTCP_NextOutPort == 0x10000) {
 773                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 774                 }
 775         }
 776
 777         // Mark the new port as used
 778         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 779
 780         return ret;
 781 }
 782
 783 /**
 784  * \fn int TCP_AllocatePort(Uint16 Port)
 785  * \brief Marks a port as used
 786  */
 787 int TCP_AllocatePort(Uint16 Port)
 788 {
 789         // Check if the port has already been allocated
 790         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 791                 return 0;
 792
 793         // Allocate
 794         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 795
 796         return 1;
 797 }
 798
 799 /**
 800  * \fn int TCP_DeallocatePort(Uint16 Port)
 801  * \brief Marks a port as unused
 802  */
 803 int TCP_DeallocatePort(Uint16 Port)
 804 {
 805         // Check if the port has already been allocated
 806         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 807                 return 0;
 808
 809         // Allocate
 810         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 811
 812         return 1;
 813 }
 814
 815 // --- Server
 816 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 817 {
 818         tTCPListener    *srv;
 819
 820         srv = malloc( sizeof(tTCPListener) );
 821
 822         if( srv == NULL ) {
 823                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 824                 return NULL;
 825         }
 826
 827         srv->Interface = Interface;
 828         srv->Port = 0;
 829         srv->NextID = 0;
 830         srv->Connections = NULL;
 831         srv->ConnectionsTail = NULL;
 832         srv->NewConnections = NULL;
 833         srv->Next = NULL;
 834         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 835         srv->Node.Size = -1;
 836         srv->Node.ImplPtr = srv;
 837         srv->Node.NumACLs = 1;
 838         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 839         srv->Node.ReadDir = TCP_Server_ReadDir;
 840         srv->Node.FindDir = TCP_Server_FindDir;
 841         srv->Node.IOCtl = TCP_Server_IOCtl;
 842         srv->Node.Close = TCP_Server_Close;
 843
 844         SHORTLOCK(&glTCP_Listeners);
 845         srv->Next = gTCP_Listeners;
 846         gTCP_Listeners = srv;
 847         SHORTREL(&glTCP_Listeners);
 848
 849         return &srv->Node;
 850 }
 851
 852 /**
 853  * \brief Wait for a new connection and return the connection ID
 854  * \note Blocks until a new connection is made
 855  * \param Node  Server node
 856  * \param Pos   Position (ignored)
 857  */
 858 char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
 859 {
 860         tTCPListener    *srv = Node->ImplPtr;
 861         tTCPConnection  *conn;
 862         char    *ret;
 863
 864         ENTER("pNode iPos", Node, Pos);
 865
 866         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 867         for(;;)
 868         {
 869                 SHORTLOCK( &srv->lConnections );
 870                 if( srv->NewConnections != NULL )       break;
 871                 SHORTREL( &srv->lConnections );
 872                 Threads_Yield();        // TODO: Sleep until poked
 873                 continue;
 874         }
 875
 876
 877         // Increment the new list (the current connection is still on the
 878         // normal list)
 879         conn = srv->NewConnections;
 880         srv->NewConnections = conn->Next;
 881
 882         SHORTREL( &srv->lConnections );
 883
 884         LOG("conn = %p", conn);
 885         LOG("srv->Connections = %p", srv->Connections);
 886         LOG("srv->NewConnections = %p", srv->NewConnections);
 887         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 888
 889         ret = malloc(9);
 890         itoa(ret, conn->Node.ImplInt, 16, 8, '0');
 891         Log_Log("TCP", "Thread %i got '%s'", Threads_GetTID(), ret);
 892         LEAVE('s', ret);
 893         return ret;
 894 }
 895
 896 /**
 897  * \brief Gets a client connection node
 898  * \param Node  Server node
 899  * \param Name  Hexadecimal ID of the node
 900  */
 901 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name)
 902 {
 903         tTCPConnection  *conn;
 904         tTCPListener    *srv = Node->ImplPtr;
 905         char    tmp[9];
 906          int    id = atoi(Name);
 907
 908         ENTER("pNode sName", Node, Name);
 909
 910         // Sanity Check
 911         itoa(tmp, id, 16, 8, '0');
 912         if(strcmp(tmp, Name) != 0) {
 913                 LOG("'%s' != '%s' (%08x)", Name, tmp, id);
 914                 LEAVE('n');
 915                 return NULL;
 916         }
 917
 918         Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
 919         Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
 920         Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 921
 922         // Search
 923         SHORTLOCK( &srv->lConnections );
 924         for(conn = srv->Connections;
 925                 conn;
 926                 conn = conn->Next)
 927         {
 928                 LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
 929                 if(conn->Node.ImplInt == id)    break;
 930         }
 931         SHORTREL( &srv->lConnections );
 932
 933         // If not found, ret NULL
 934         if(!conn) {
 935                 LOG("Connection %i not found", id);
 936                 LEAVE('n');
 937                 return NULL;
 938         }
 939
 940         // Return node
 941         LEAVE('p', &conn->Node);
 942         return &conn->Node;
 943 }
 944
 945 /**
 946  * \brief Handle IOCtl calls
 947  */
 948 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
 949 {
 950         tTCPListener    *srv = Node->ImplPtr;
 951
 952         switch(ID)
 953         {
 954         case 4: // Get/Set Port
 955                 if(!Data)       // Get Port
 956                         return srv->Port;
 957
 958                 if(srv->Port)   // Wait, you can't CHANGE the port
 959                         return -1;
 960
 961                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
 962                         return -1;
 963
 964                 // Permissions check
 965                 if(Threads_GetUID() != 0
 966                 && *(Uint16*)Data != 0
 967                 && *(Uint16*)Data < 1024)
 968                         return -1;
 969
 970                 // TODO: Check if a port is in use
 971
 972                 // Set Port
 973                 srv->Port = *(Uint16*)Data;
 974                 if(srv->Port == 0)      // Allocate a random port
 975                         srv->Port = TCP_GetUnusedPort();
 976                 else    // Else, mark this as used
 977                         TCP_AllocatePort(srv->Port);
 978
 979                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
 980
 981                 return srv->Port;
 982         }
 983         return 0;
 984 }
 985
 986 void TCP_Server_Close(tVFS_Node *Node)
 987 {
 988         free(Node->ImplPtr);
 989 }
 990
 991 // --- Client
 992 /**
 993  * \brief Create a client node
 994  */
 995 tVFS_Node *TCP_Client_Init(tInterface *Interface)
 996 {
 997         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
 998
 999         conn->State = TCP_ST_CLOSED;
1000         conn->Interface = Interface;
1001         conn->LocalPort = -1;
1002         conn->RemotePort = -1;
1003
1004         conn->Node.ImplPtr = conn;
1005         conn->Node.NumACLs = 1;
1006         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
1007         conn->Node.Read = TCP_Client_Read;
1008         conn->Node.Write = TCP_Client_Write;
1009         conn->Node.IOCtl = TCP_Client_IOCtl;
1010         conn->Node.Close = TCP_Client_Close;
1011
1012         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
1013         #if 0
1014         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
1015         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
1016         #endif
1017
1018         #if CACHE_FUTURE_PACKETS_IN_BYTES
1019         // Future recieved data (ahead of the expected sequence number)
1020         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
1021         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
1022         #endif
1023
1024         SHORTLOCK(&glTCP_OutbountCons);
1025         conn->Next = gTCP_OutbountCons;
1026         gTCP_OutbountCons = conn;
1027         SHORTREL(&glTCP_OutbountCons);
1028
1029         return &conn->Node;
1030 }
1031
1032 /**
1033  * \brief Wait for a packet and return it
1034  * \note If \a Length is smaller than the size of the packet, the rest
1035  *       of the packet's data will be discarded.
1036  */
1037 Uint64 TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
1038 {
1039         tTCPConnection  *conn = Node->ImplPtr;
1040         size_t  len;
1041
1042         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1043         LOG("conn = %p {State:%i}", conn, conn->State);
1044
1045         // Check if connection is estabilishing
1046         // - TODO: Sleep instead (maybe using VFS_SelectNode to wait for the
1047         //   data to be availiable
1048         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1049                 Threads_Yield();
1050
1051         // If the conneciton is not open, then clean out the recieved buffer
1052         if( conn->State != TCP_ST_OPEN )
1053         {
1054                 Mutex_Acquire( &conn->lRecievedPackets );
1055                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1056                 Mutex_Release( &conn->lRecievedPackets );
1057
1058                 if( len == 0 ) {
1059                         VFS_MarkAvaliable(Node, 0);
1060                         LEAVE('i', -1);
1061                         return -1;
1062                 }
1063
1064                 LEAVE('i', len);
1065                 return len;
1066         }
1067
1068         // Wait
1069         VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, NULL, "TCP_Client_Read");
1070
1071         // Lock list and read as much as possible (up to `Length`)
1072         Mutex_Acquire( &conn->lRecievedPackets );
1073         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1074
1075         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1076                 LOG("Marking as none avaliable (len = %i)", len);
1077                 VFS_MarkAvaliable(Node, 0);
1078         }
1079
1080         // Release the lock (we don't need it any more)
1081         Mutex_Release( &conn->lRecievedPackets );
1082
1083         LEAVE('i', len);
1084         return len;
1085 }
1086
1087 /**
1088  * \brief Send a data packet on a connection
1089  */
1090 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, void *Data)
1091 {
1092         char    buf[sizeof(tTCPHeader)+Length];
1093         tTCPHeader      *packet = (void*)buf;
1094
1095         packet->SourcePort = htons(Connection->LocalPort);
1096         packet->DestPort = htons(Connection->RemotePort);
1097         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1098         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1099
1100         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1101         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1102         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1103
1104         memcpy(packet->Options, Data, Length);
1105
1106         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1107 #if HEXDUMP_OUTGOING
1108         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1109 #endif
1110
1111         TCP_SendPacket( Connection, sizeof(tTCPHeader)+Length, packet );
1112
1113         Connection->NextSequenceSend += Length;
1114 }
1115
1116 /**
1117  * \brief Send some bytes on a connection
1118  */
1119 Uint64 TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
1120 {
1121         tTCPConnection  *conn = Node->ImplPtr;
1122         size_t  rem = Length;
1123
1124         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1125
1126 //      #if DEBUG
1127 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1128 //              Buffer, Length);
1129 //      #endif
1130
1131         // Check if connection is open
1132         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1133                 Threads_Yield();
1134
1135         if( conn->State != TCP_ST_OPEN ) {
1136                 VFS_MarkError(Node, 1);
1137                 LEAVE('i', -1);
1138                 return -1;
1139         }
1140
1141         do
1142         {
1143                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1144
1145                 #if 0
1146                 // Wait for space in the buffer
1147                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1148
1149                 // Save data to buffer (and update the length read by the ammount written)
1150                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1151                 #endif
1152
1153                 // Send packet
1154                 TCP_INT_SendDataPacket(conn, len, Buffer);
1155
1156                 Buffer += len;
1157                 rem -= len;
1158         } while( rem > 0 );
1159
1160         LEAVE('i', Length);
1161         return Length;
1162 }
1163
1164 /**
1165  * \brief Open a connection to another host using TCP
1166  * \param Conn  Connection structure
1167  */
1168 void TCP_StartConnection(tTCPConnection *Conn)
1169 {
1170         tTCPHeader      hdr = {0};
1171
1172         Conn->State = TCP_ST_SYN_SENT;
1173
1174         hdr.SourcePort = htons(Conn->LocalPort);
1175         hdr.DestPort = htons(Conn->RemotePort);
1176         Conn->NextSequenceSend = rand();
1177         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1178         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1179         hdr.Flags = TCP_FLAG_SYN;
1180         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1181         hdr.Checksum = 0;       // TODO
1182
1183         TCP_SendPacket( Conn, sizeof(tTCPHeader), &hdr );
1184
1185         Conn->NextSequenceSend ++;
1186         Conn->State = TCP_ST_SYN_SENT;
1187
1188         return ;
1189 }
1190
1191 /**
1192  * \brief Control a client socket
1193  */
1194 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1195 {
1196         tTCPConnection  *conn = Node->ImplPtr;
1197
1198         ENTER("pNode iID pData", Node, ID, Data);
1199
1200         switch(ID)
1201         {
1202         case 4: // Get/Set local port
1203                 if(!Data)
1204                         LEAVE_RET('i', conn->LocalPort);
1205                 if(conn->State != TCP_ST_CLOSED)
1206                         LEAVE_RET('i', -1);
1207                 if(!CheckMem(Data, sizeof(Uint16)))
1208                         LEAVE_RET('i', -1);
1209
1210                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1211                         LEAVE_RET('i', -1);
1212
1213                 conn->LocalPort = *(Uint16*)Data;
1214                 LEAVE_RET('i', conn->LocalPort);
1215
1216         case 5: // Get/Set remote port
1217                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1218                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1219                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1220                 conn->RemotePort = *(Uint16*)Data;
1221                 LEAVE_RET('i', conn->RemotePort);
1222
1223         case 6: // Set Remote IP
1224                 if( conn->State != TCP_ST_CLOSED )
1225                         LEAVE_RET('i', -1);
1226                 if( conn->Interface->Type == 4 )
1227                 {
1228                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1229                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1230                 }
1231                 else if( conn->Interface->Type == 6 )
1232                 {
1233                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1234                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1235                 }
1236                 LEAVE_RET('i', 0);
1237
1238         case 7: // Connect
1239                 if(conn->LocalPort == 0xFFFF)
1240                         conn->LocalPort = TCP_GetUnusedPort();
1241                 if(conn->RemotePort == -1)
1242                         LEAVE_RET('i', 0);
1243
1244                 {
1245                         tTime   timeout_end = now() + conn->Interface->TimeoutDelay;
1246
1247                         TCP_StartConnection(conn);
1248                         // TODO: Wait for connection to open
1249                         while( conn->State == TCP_ST_SYN_SENT && timeout_end > now() ) {
1250                                 Threads_Yield();
1251                         }
1252                         if( conn->State == TCP_ST_SYN_SENT )
1253                                 LEAVE_RET('i', 0);
1254                 }
1255
1256                 LEAVE_RET('i', 1);
1257
1258         // Get recieve buffer length
1259         case 8:
1260                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1261         }
1262
1263         return 0;
1264 }
1265
1266 void TCP_Client_Close(tVFS_Node *Node)
1267 {
1268         tTCPConnection  *conn = Node->ImplPtr;
1269         tTCPHeader      packet;
1270
1271         ENTER("pNode", Node);
1272
1273         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1274         {
1275                 packet.SourcePort = htons(conn->LocalPort);
1276                 packet.DestPort = htons(conn->RemotePort);
1277                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1278                 packet.WindowSize = TCP_WINDOW_SIZE;
1279
1280                 packet.AcknowlegementNumber = 0;
1281                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1282                 packet.Flags = TCP_FLAG_FIN;
1283
1284                 TCP_SendPacket( conn, sizeof(tTCPHeader), &packet );
1285         }
1286
1287         switch( conn->State )
1288         {
1289         case TCP_ST_CLOSE_WAIT:
1290                 conn->State = TCP_ST_LAST_ACK;
1291                 break;
1292         case TCP_ST_OPEN:
1293                 conn->State = TCP_ST_FIN_WAIT1;
1294                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1295                 break;
1296         default:
1297                 Log_Warning("TCP", "Unhandled connection state in TCP_Client_Close");
1298                 break;
1299         }
1300
1301         free(conn);
1302
1303         LEAVE('-');
1304 }
1305
1306 /**
1307  * \brief Checks if a value is between two others (after taking into account wrapping)
1308  */
1309 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1310 {
1311         if( MaxValue < 0xFFFFFFFF )
1312         {
1313                 Lower %= MaxValue + 1;
1314                 Value %= MaxValue + 1;
1315                 Higher %= MaxValue + 1;
1316         }
1317
1318         // Simple Case, no wrap ?
1319         //       Lower Value Higher
1320         // | ... + ... + ... + ... |
1321
1322         if( Lower < Higher ) {
1323                 return Lower < Value && Value < Higher;
1324         }
1325         // Higher has wrapped below lower
1326
1327         // Value > Lower ?
1328         //       Higher Lower Value
1329         // | ... +  ... + ... + ... |
1330         if( Value > Lower ) {
1331                 return 1;
1332         }
1333
1334         // Value < Higher ?
1335         //       Value Higher Lower
1336         // | ... + ... +  ... + ... |
1337         if( Value < Higher ) {
1338                 return 1;
1339         }
1340
1341         return 0;
1342 }