KernelLand/Modules/IPStack/tcp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - TCP Handling
   4  */
   5 #define DEBUG   0
   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 0x8000
  22 #define TCP_DACK_THRESHOLD      4096
  23 #define TCP_DACK_TIMEOUT        500
  24
  25 // === PROTOTYPES ===
  26 void    TCP_Initialise(void);
  27 void    TCP_StartConnection(tTCPConnection *Conn);
  28 void    TCP_SendPacket(tTCPConnection *Conn, tTCPHeader *Header, size_t DataLen, const void *Data);
  29 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  30 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  31 int     TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length);
  32 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  33 void    TCP_INT_SendACK(tTCPConnection *Connection);
  34 Uint16  TCP_GetUnusedPort();
  35  int    TCP_AllocatePort(Uint16 Port);
  36  int    TCP_DeallocatePort(Uint16 Port);
  37 // --- Server
  38 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  39  int    TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Name[FILENAME_MAX]);
  40 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags);
  41  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  42 void    TCP_Server_Close(tVFS_Node *Node);
  43 // --- Client
  44 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  45 size_t  TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  46 size_t  TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags);
  47  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  48 void    TCP_Client_Close(tVFS_Node *Node);
  49 // --- Helpers
  50  int    WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
  51
  52 // === TEMPLATES ===
  53 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  54 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  55 tVFS_NodeType   gTCP_ServerNodeType = {
  56         .TypeName = "TCP Server",
  57         .ReadDir = TCP_Server_ReadDir,
  58         .FindDir = TCP_Server_FindDir,
  59         .IOCtl   = TCP_Server_IOCtl,
  60         .Close   = TCP_Server_Close
  61         };
  62 tVFS_NodeType   gTCP_ClientNodeType = {
  63         .TypeName = "TCP Client/Connection",
  64         .Read  = TCP_Client_Read,
  65         .Write = TCP_Client_Write,
  66         .IOCtl = TCP_Client_IOCtl,
  67         .Close = TCP_Client_Close
  68         };
  69
  70 // === GLOBALS ===
  71  int    giTCP_NumHalfopen = 0;
  72 tShortSpinlock  glTCP_Listeners;
  73 tTCPListener    *gTCP_Listeners;
  74 tShortSpinlock  glTCP_OutbountCons;
  75 tTCPConnection  *gTCP_OutbountCons;
  76 Uint32  gaTCP_PortBitmap[0x800];
  77  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  78
  79 // === CODE ===
  80 /**
  81  * \brief Initialise the TCP Layer
  82  *
  83  * Registers the client and server files and the GetPacket callback
  84  */
  85 void TCP_Initialise(void)
  86 {
  87         giTCP_NextOutPort += rand()%32;
  88         IPStack_AddFile(&gTCP_ServerFile);
  89         IPStack_AddFile(&gTCP_ClientFile);
  90         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  91         IPv6_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  92 }
  93
  94 /**
  95  * \brief Sends a packet from the specified connection, calculating the checksums
  96  * \param Conn  Connection
  97  * \param Length        Length of data
  98  * \param Data  Packet data (cast as a TCP Header)
  99  */
 100 void TCP_SendPacket( tTCPConnection *Conn, tTCPHeader *Header, size_t Length, const void *Data )
 101 {
 102         tIPStackBuffer  *buffer;
 103         Uint16  checksum[3];
 104          int    packlen = sizeof(*Header) + Length;
 105
 106         buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
 107         if( Data && Length )
 108                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
 109         IPStack_Buffer_AppendSubBuffer(buffer, sizeof(*Header), 0, Header, NULL, NULL);
 110
 111         LOG("Sending %i+%i to %s:%i", sizeof(*Header), Length,
 112                 IPStack_PrintAddress(Conn->Interface->Type, &Conn->RemoteIP),
 113                 Conn->RemotePort
 114                 );
 115
 116         Header->Checksum = 0;
 117         checksum[1] = htons( ~IPv4_Checksum(Header, sizeof(tTCPHeader)) );
 118         checksum[2] = htons( ~IPv4_Checksum(Data, Length) );
 119
 120         // TODO: Fragment packet
 121
 122         switch( Conn->Interface->Type )
 123         {
 124         case 4:
 125                 // Get IPv4 pseudo-header checksum
 126                 {
 127                         Uint32  buf[3];
 128                         buf[0] = ((tIPv4*)Conn->Interface->Address)->L;
 129                         buf[1] = Conn->RemoteIP.v4.L;
 130                         buf[2] = (htons(packlen)<<16) | (6<<8) | 0;
 131                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 132                 }
 133                 // - Combine checksums
 134                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );
 135                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, buffer);
 136                 break;
 137
 138         case 6:
 139                 // Append IPv6 Pseudo Header
 140                 {
 141                         Uint32  buf[4+4+1+1];
 142                         memcpy(buf, Conn->Interface->Address, 16);
 143                         memcpy(&buf[4], &Conn->RemoteIP, 16);
 144                         buf[8] = htonl(packlen);
 145                         buf[9] = htonl(6);
 146                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 147                 }
 148                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );  // Combine the two
 149                 IPv6_SendPacket(Conn->Interface, Conn->RemoteIP.v6, IP4PROT_TCP, Length, Data);
 150                 break;
 151         }
 152 }
 153
 154 /**
 155  * \brief Handles a packet from the IP Layer
 156  * \param Interface     Interface the packet arrived from
 157  * \param Address       Pointer to the addres structure
 158  * \param Length        Size of packet in bytes
 159  * \param Buffer        Packet data
 160  */
 161 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 162 {
 163         tTCPHeader      *hdr = Buffer;
 164         tTCPListener    *srv;
 165         tTCPConnection  *conn;
 166
 167         Log_Log("TCP", "TCP_GetPacket: <Local>:%i from [%s]:%i, Flags = %s%s%s%s%s%s%s%s",
 168                 ntohs(hdr->DestPort),
 169                 IPStack_PrintAddress(Interface->Type, Address),
 170                 ntohs(hdr->SourcePort),
 171                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
 172                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
 173                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
 174                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
 175                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
 176                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
 177                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
 178                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
 179                 );
 180
 181         if( Length > (hdr->DataOffset >> 4)*4 )
 182         {
 183                 LOG("SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 184 #if HEXDUMP_INCOMING
 185                 Debug_HexDump(
 186                         "TCP_GetPacket: Packet Data = ",
 187                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 188                         Length - (hdr->DataOffset >> 4)*4
 189                         );
 190 #endif
 191         }
 192
 193         // Check Servers
 194         for( srv = gTCP_Listeners; srv; srv = srv->Next )
 195         {
 196                 // Check if the server is active
 197                 if(srv->Port == 0)      continue;
 198                 // Check the interface
 199                 if(srv->Interface && srv->Interface != Interface)       continue;
 200                 // Check the destination port
 201                 if(srv->Port != htons(hdr->DestPort))   continue;
 202
 203                 Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 204                 // Is this in an established connection?
 205                 for( conn = srv->Connections; conn; conn = conn->Next )
 206                 {
 207                         // Check that it is coming in on the same interface
 208                         if(conn->Interface != Interface)        continue;
 209
 210                         // Check Source Port
 211                         Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 212                                 conn->RemotePort, ntohs(hdr->SourcePort));
 213                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 214
 215                         // Check Source IP
 216                         Log_Debug("TCP", "TCP_GetPacket: conn->RemoteIP(%s)",
 217                                 IPStack_PrintAddress(conn->Interface->Type, &conn->RemoteIP));
 218                         Log_Debug("TCP", "                == Address(%s)",
 219                                 IPStack_PrintAddress(conn->Interface->Type, Address));
 220                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
 221                                 continue ;
 222
 223                         Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 224                         // We have a response!
 225                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 226
 227                         return;
 228                 }
 229
 230                 Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 231                 // Open a new connection (well, check that it's a SYN)
 232                 if(hdr->Flags != TCP_FLAG_SYN) {
 233                         Log_Log("TCP", "TCP_GetPacket: Packet is not a SYN");
 234                         return ;
 235                 }
 236
 237                 // TODO: Check for halfopen max
 238
 239                 conn = calloc(1, sizeof(tTCPConnection));
 240                 conn->State = TCP_ST_SYN_RCVD;
 241                 conn->LocalPort = srv->Port;
 242                 conn->RemotePort = ntohs(hdr->SourcePort);
 243                 conn->Interface = Interface;
 244
 245                 switch(Interface->Type)
 246                 {
 247                 case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 248                 case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 249                 }
 250
 251                 conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 252
 253                 conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 254                 conn->NextSequenceSend = rand();
 255
 256                 // Create node
 257                 conn->Node.NumACLs = 1;
 258                 conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 259                 conn->Node.ImplPtr = conn;
 260                 conn->Node.ImplInt = srv->NextID ++;
 261                 conn->Node.Type = &gTCP_ClientNodeType; // TODO: Special type for the server end?
 262
 263                 // Hmm... Theoretically, this lock will never have to wait,
 264                 // as the interface is locked to the watching thread, and this
 265                 // runs in the watching thread. But, it's a good idea to have
 266                 // it, just in case
 267                 // Oh, wait, there is a case where a wildcard can be used
 268                 // (srv->Interface == NULL) so having the lock is a good idea
 269                 SHORTLOCK(&srv->lConnections);
 270                 if( !srv->Connections )
 271                         srv->Connections = conn;
 272                 else
 273                         srv->ConnectionsTail->Next = conn;
 274                 srv->ConnectionsTail = conn;
 275                 if(!srv->NewConnections)
 276                         srv->NewConnections = conn;
 277                 VFS_MarkAvaliable( &srv->Node, 1 );
 278                 SHORTREL(&srv->lConnections);
 279                 Semaphore_Signal(&srv->WaitingConnections, 1);
 280
 281                 // Send the SYN ACK
 282                 hdr->Flags |= TCP_FLAG_ACK;
 283                 hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 284                 hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 285                 hdr->DestPort = hdr->SourcePort;
 286                 hdr->SourcePort = htons(srv->Port);
 287                 hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 288                 TCP_SendPacket( conn, hdr, 0, NULL );
 289                 conn->NextSequenceSend ++;
 290                 return ;
 291         }
 292
 293         // Check Open Connections
 294         {
 295                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 296                 {
 297                         // Check that it is coming in on the same interface
 298                         if(conn->Interface != Interface)        continue;
 299
 300                         // Check Source Port
 301                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 302
 303                         // Check Source IP
 304                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 305                                 continue;
 306                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 307                                 continue;
 308
 309                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 310                         return ;
 311                 }
 312         }
 313
 314         Log_Log("TCP", "TCP_GetPacket: No Match");
 315 }
 316
 317 /**
 318  * \brief Handles a packet sent to a specific connection
 319  * \param Connection    TCP Connection pointer
 320  * \param Header        TCP Packet pointer
 321  * \param Length        Length of the packet
 322  */
 323 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 324 {
 325          int    dataLen;
 326         Uint32  sequence_num;
 327
 328         // Silently drop once finished
 329         // TODO: Check if this needs to be here
 330         if( Connection->State == TCP_ST_FINISHED ) {
 331                 Log_Log("TCP", "Packet ignored - connection finnished");
 332                 return ;
 333         }
 334
 335         // Syncronise sequence values
 336         if(Header->Flags & TCP_FLAG_SYN) {
 337                 // TODO: What if the packet also has data?
 338                 if( Connection->LastACKSequence != Connection->NextSequenceRcv )
 339                         TCP_INT_SendACK(Connection);
 340                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
 341                 Connection->LastACKSequence = Connection->NextSequenceRcv;
 342         }
 343
 344         // Ackowledge a sent packet
 345         if(Header->Flags & TCP_FLAG_ACK) {
 346                 // TODO: Process an ACKed Packet
 347                 LOG("Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 348         }
 349
 350         // Get length of data
 351         dataLen = Length - (Header->DataOffset>>4)*4;
 352         LOG("dataLen = %i", dataLen);
 353         Log_Debug("TCP", "State %i, dataLen = %x", Connection->State, dataLen);
 354
 355         //
 356         // State Machine
 357         //
 358         switch( Connection->State )
 359         {
 360         // Pre-init connection?
 361         case TCP_ST_CLOSED:
 362                 Log_Log("TCP", "Packets to a closed connection?!");
 363                 break;
 364
 365         // --- Init States ---
 366         // SYN sent, expecting SYN-ACK Connection Opening
 367         case TCP_ST_SYN_SENT:
 368                 if( Header->Flags & TCP_FLAG_SYN )
 369                 {
 370                         Connection->NextSequenceRcv ++;
 371
 372                         if( Header->Flags & TCP_FLAG_ACK )
 373                         {
 374                                 Log_Log("TCP", "ACKing SYN-ACK");
 375                                 Connection->State = TCP_ST_OPEN;
 376                                 VFS_MarkFull(&Connection->Node, 0);
 377                         }
 378                         else
 379                         {
 380                                 Log_Log("TCP", "ACKing SYN");
 381                                 Connection->State = TCP_ST_SYN_RCVD;
 382                         }
 383                         Header->DestPort = Header->SourcePort;
 384                         Header->SourcePort = htons(Connection->LocalPort);
 385                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 386                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 387                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 388                         Header->Flags = TCP_FLAG_ACK;
 389                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 390                         TCP_SendPacket( Connection, Header, 0, NULL );
 391                 }
 392                 break;
 393
 394         // SYN-ACK sent, expecting ACK
 395         case TCP_ST_SYN_RCVD:
 396                 if( Header->Flags & TCP_FLAG_ACK )
 397                 {
 398                         // TODO: Handle max half-open limit
 399                         Log_Log("TCP", "Connection fully opened");
 400                         Connection->State = TCP_ST_OPEN;
 401                         VFS_MarkFull(&Connection->Node, 0);
 402                 }
 403                 break;
 404
 405         // --- Established State ---
 406         case TCP_ST_OPEN:
 407                 // - Handle State changes
 408                 //
 409                 if( Header->Flags & TCP_FLAG_FIN ) {
 410                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
 411                         VFS_MarkError(&Connection->Node, 1);
 412                         Connection->State = TCP_ST_CLOSE_WAIT;
 413 //                      Header->Flags &= ~TCP_FLAG_FIN;
 414                         // CLOSE WAIT requires the client to close (or does it?)
 415                         #if 0
 416
 417                         #endif
 418                 }
 419
 420                 // Check for an empty packet
 421                 if(dataLen == 0) {
 422                         if( Header->Flags == TCP_FLAG_ACK )
 423                         {
 424                                 Log_Log("TCP", "ACK only packet");
 425                                 return ;
 426                         }
 427                         Connection->NextSequenceRcv ++; // TODO: Is this right? (empty packet counts as one byte)
 428                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
 429                         TCP_INT_SendACK(Connection);
 430                         #if 0
 431                         Header->DestPort = Header->SourcePort;
 432                         Header->SourcePort = htons(Connection->LocalPort);
 433                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 434                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 435                         Header->Flags |= TCP_FLAG_ACK;
 436                         TCP_SendPacket( Connection, Header, 0, NULL );
 437                         #endif
 438                         return ;
 439                 }
 440
 441                 // NOTES:
 442                 // Flags
 443                 //    PSH - Has Data?
 444                 // /NOTES
 445
 446                 sequence_num = ntohl(Header->SequenceNumber);
 447
 448                 LOG("0x%08x <= 0x%08x < 0x%08x",
 449                         Connection->NextSequenceRcv,
 450                         ntohl(Header->SequenceNumber),
 451                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
 452                         );
 453
 454                 // Is this packet the next expected packet?
 455                 if( sequence_num == Connection->NextSequenceRcv )
 456                 {
 457                          int    rv;
 458                         // Ooh, Goodie! Add it to the recieved list
 459                         rv = TCP_INT_AppendRecieved(Connection,
 460                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 461                                 dataLen
 462                                 );
 463                         if(rv != 0) {
 464                                 Log_Notice("TCP", "TCP_INT_AppendRecieved rv %i", rv);
 465                                 break;
 466                         }
 467                         LOG("0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 468                         Connection->NextSequenceRcv += dataLen;
 469
 470                         // TODO: This should be moved out of the watcher thread,
 471                         // so that a single lost packet on one connection doesn't cause
 472                         // all connections on the interface to lag.
 473                         // - Meh, no real issue, as the cache shouldn't be that large
 474                         TCP_INT_UpdateRecievedFromFuture(Connection);
 475
 476                         #if 1
 477                         // - Only send an ACK if we've had a burst
 478                         if( Connection->NextSequenceRcv > (Uint32)(TCP_DACK_THRESHOLD + Connection->LastACKSequence) )
 479                         {
 480                                 TCP_INT_SendACK(Connection);
 481                                 // - Extend TCP deferred ACK timer
 482                                 Time_RemoveTimer(Connection->DeferredACKTimer);
 483                         }
 484                         // - Schedule the deferred ACK timer (if already scheduled, this is a NOP)
 485                         Time_ScheduleTimer(Connection->DeferredACKTimer, TCP_DACK_TIMEOUT);
 486                         #else
 487                         TCP_INT_SendACK(Connection);
 488                         #endif
 489                 }
 490                 // Check if the packet is in window
 491                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 492                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 493                 {
 494                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 495                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 496                         Uint32  index;
 497                          int    i;
 498
 499                         index = sequence_num % TCP_WINDOW_SIZE;
 500                         for( i = 0; i < dataLen; i ++ )
 501                         {
 502                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
 503                                 Connection->FuturePacketData[index] = dataptr[i];
 504                                 // Do a wrap increment
 505                                 index ++;
 506                                 if(index == TCP_WINDOW_SIZE)    index = 0;
 507                         }
 508                         #else
 509                         tTCPStoredPacket        *pkt, *tmp, *prev = NULL;
 510
 511                         // Allocate and fill cached packet
 512                         pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
 513                         pkt->Next = NULL;
 514                         pkt->Sequence = ntohl(Header->SequenceNumber);
 515                         pkt->Length = dataLen;
 516                         memcpy(pkt->Data, dataptr, dataLen);
 517
 518                         Log_Log("TCP", "We missed a packet, caching",
 519                                 pkt->Sequence, Connection->NextSequenceRcv);
 520
 521                         // No? Well, let's cache it and look at it later
 522                         SHORTLOCK( &Connection->lFuturePackets );
 523                         for(tmp = Connection->FuturePackets;
 524                                 tmp;
 525                                 prev = tmp, tmp = tmp->Next)
 526                         {
 527                                 if(tmp->Sequence >= pkt->Sequence)      break;
 528                         }
 529
 530                         // Add if before first, or sequences don't match
 531                         if( !tmp || tmp->Sequence != pkt->Sequence )
 532                         {
 533                                 if(prev)
 534                                         prev->Next = pkt;
 535                                 else
 536                                         Connection->FuturePackets = pkt;
 537                                 pkt->Next = tmp;
 538                         }
 539                         // Replace if larger
 540                         else if(pkt->Length > tmp->Length)
 541                         {
 542                                 if(prev)
 543                                         prev->Next = pkt;
 544                                 pkt->Next = tmp->Next;
 545                                 free(tmp);
 546                         }
 547                         else
 548                         {
 549                                 free(pkt);      // TODO: Find some way to remove this
 550                         }
 551                         SHORTREL( &Connection->lFuturePackets );
 552                         #endif
 553                 }
 554                 // Badly out of sequence packet
 555                 else
 556                 {
 557                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
 558                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
 559                         // Spec says we should send an empty ACK with the current state
 560                         TCP_INT_SendACK(Connection);
 561                 }
 562                 break;
 563
 564         // --- Remote close states
 565         case TCP_ST_CLOSE_WAIT:
 566
 567                 // Ignore everything, CLOSE_WAIT is terminated by the client
 568                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
 569
 570                 break;
 571
 572         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
 573         case TCP_ST_LAST_ACK:
 574                 if( Header->Flags & TCP_FLAG_ACK )
 575                 {
 576                         Connection->State = TCP_ST_FINISHED;    // Connection completed
 577                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
 578                         // TODO: Destrory the TCB
 579                 }
 580                 break;
 581
 582         // --- Local close States
 583         case TCP_ST_FIN_WAIT1:
 584                 if( Header->Flags & TCP_FLAG_FIN )
 585                 {
 586                         Connection->State = TCP_ST_CLOSING;
 587                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
 588                         VFS_MarkError(&Connection->Node, 1);
 589
 590                         // ACK Packet
 591                         Header->DestPort = Header->SourcePort;
 592                         Header->SourcePort = htons(Connection->LocalPort);
 593                         Header->AcknowlegementNumber = Header->SequenceNumber;
 594                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 595                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 596                         Header->Flags = TCP_FLAG_ACK;
 597                         TCP_SendPacket( Connection, Header, 0, NULL );
 598                         break ;
 599                 }
 600
 601                 // TODO: Make sure that the packet is actually ACKing the FIN
 602                 if( Header->Flags & TCP_FLAG_ACK )
 603                 {
 604                         Connection->State = TCP_ST_FIN_WAIT2;
 605                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
 606                         VFS_MarkError(&Connection->Node, 1);
 607                         return ;
 608                 }
 609                 break;
 610
 611         case TCP_ST_FIN_WAIT2:
 612                 if( Header->Flags & TCP_FLAG_FIN )
 613                 {
 614                         Connection->State = TCP_ST_TIME_WAIT;
 615                         Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
 616                         // Send ACK
 617                         Header->DestPort = Header->SourcePort;
 618                         Header->SourcePort = htons(Connection->LocalPort);
 619                         Header->AcknowlegementNumber = Header->SequenceNumber;
 620                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 621                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 622                         Header->Flags = TCP_FLAG_ACK;
 623                         TCP_SendPacket( Connection, Header, 0, NULL );
 624                 }
 625                 break;
 626
 627         case TCP_ST_CLOSING:
 628                 // TODO: Make sure that the packet is actually ACKing the FIN
 629                 if( Header->Flags & TCP_FLAG_ACK )
 630                 {
 631                         Connection->State = TCP_ST_TIME_WAIT;
 632                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
 633                         VFS_MarkError(&Connection->Node, 1);
 634                         return ;
 635                 }
 636                 break;
 637
 638         // --- Closed (or near closed) states) ---
 639         case TCP_ST_TIME_WAIT:
 640                 Log_Log("TCP", "Packets on Time-Wait, ignored");
 641                 break;
 642
 643         case TCP_ST_FINISHED:
 644                 Log_Log("TCP", "Packets when CLOSED, ignoring");
 645                 break;
 646
 647         //default:
 648         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
 649         //      break;
 650         }
 651
 652 }
 653
 654 /**
 655  * \brief Appends a packet to the recieved list
 656  * \param Connection    Connection structure
 657  * \param Data  Packet contents
 658  * \param Length        Length of \a Data
 659  */
 660 int TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
 661 {
 662         Mutex_Acquire( &Connection->lRecievedPackets );
 663
 664         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
 665         {
 666                 VFS_MarkAvaliable(&Connection->Node, 1);
 667                 Log_Error("TCP", "Buffer filled, packet dropped (:%i) - %i + %i > %i",
 668                         Connection->LocalPort, Connection->RecievedBuffer->Length, Length,
 669                         Connection->RecievedBuffer->Space
 670                         );
 671                 Mutex_Release( &Connection->lRecievedPackets );
 672                 return 1;
 673         }
 674
 675         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
 676
 677         VFS_MarkAvaliable(&Connection->Node, 1);
 678
 679         Mutex_Release( &Connection->lRecievedPackets );
 680         return 0;
 681 }
 682
 683 /**
 684  * \brief Updates the connections recieved list from the future list
 685  * \param Connection    Connection structure
 686  *
 687  * Updates the recieved packets list with packets from the future (out
 688  * of order) packets list that are now able to be added in direct
 689  * sequence.
 690  */
 691 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 692 {
 693         #if CACHE_FUTURE_PACKETS_IN_BYTES
 694          int    i, length = 0;
 695         Uint32  index;
 696
 697         // Calculate length of contiguous bytes
 698         length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 699         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 700         for( i = 0; i < length; i ++ )
 701         {
 702                 if( Connection->FuturePacketValidBytes[i / 8] == 0xFF ) {
 703                         i += 7; index += 7;
 704                         continue;
 705                 }
 706                 else if( !(Connection->FuturePacketValidBytes[i / 8] & (1 << (i%8))) )
 707                         break;
 708
 709                 index ++;
 710                 if(index > TCP_WINDOW_SIZE)
 711                         index -= TCP_WINDOW_SIZE;
 712         }
 713         length = i;
 714
 715         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 716
 717         // Write data to to the ring buffer
 718         if( TCP_WINDOW_SIZE - index > length )
 719         {
 720                 // Simple case
 721                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 722         }
 723         else
 724         {
 725                  int    endLen = TCP_WINDOW_SIZE - index;
 726                 // 2-part case
 727                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 728                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 729         }
 730
 731         // Mark (now saved) bytes as invalid
 732         // - Align index
 733         while(index % 8 && length)
 734         {
 735                 Connection->FuturePacketData[index] = 0;
 736                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 737                 index ++;
 738                 if(index > TCP_WINDOW_SIZE)
 739                         index -= TCP_WINDOW_SIZE;
 740                 length --;
 741         }
 742         while( length > 7 )
 743         {
 744                 Connection->FuturePacketData[index] = 0;
 745                 Connection->FuturePacketValidBytes[index/8] = 0;
 746                 length -= 8;
 747                 index += 8;
 748                 if(index > TCP_WINDOW_SIZE)
 749                         index -= TCP_WINDOW_SIZE;
 750         }
 751         while(length)
 752         {
 753                 Connection->FuturePacketData[index] = 0;
 754                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 755                 index ++;
 756                 if(index > TCP_WINDOW_SIZE)
 757                         index -= TCP_WINDOW_SIZE;
 758                 length --;
 759         }
 760
 761         #else
 762         tTCPStoredPacket        *pkt;
 763         for(;;)
 764         {
 765                 SHORTLOCK( &Connection->lFuturePackets );
 766
 767                 // Clear out duplicates from cache
 768                 // - If a packet has just been recieved, and it is expected, then
 769                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 770                 //   packets in cache that are smaller than the next expected
 771                 //   are now defunct.
 772                 pkt = Connection->FuturePackets;
 773                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 774                 {
 775                         tTCPStoredPacket        *next = pkt->Next;
 776                         free(pkt);
 777                         pkt = next;
 778                 }
 779
 780                 // If there's no packets left in cache, stop looking
 781                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 782                         SHORTREL( &Connection->lFuturePackets );
 783                         return;
 784                 }
 785
 786                 // Delete packet from future list
 787                 Connection->FuturePackets = pkt->Next;
 788
 789                 // Release list
 790                 SHORTREL( &Connection->lFuturePackets );
 791
 792                 // Looks like we found one
 793                 TCP_INT_AppendRecieved(Connection, pkt);
 794                 Connection->NextSequenceRcv += pkt->Length;
 795                 free(pkt);
 796         }
 797         #endif
 798 }
 799
 800 void TCP_INT_SendACK(tTCPConnection *Connection)
 801 {
 802         tTCPHeader      hdr;
 803         // ACK Packet
 804         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
 805         hdr.DestPort = htons(Connection->RemotePort);
 806         hdr.SourcePort = htons(Connection->LocalPort);
 807         hdr.AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 808         hdr.SequenceNumber = htonl(Connection->NextSequenceSend);
 809         hdr.WindowSize = htons(TCP_WINDOW_SIZE);
 810         hdr.Flags = TCP_FLAG_ACK;       // TODO: Determine if SYN is wanted too
 811         hdr.Checksum = 0;       // TODO: Checksum
 812         hdr.UrgentPointer = 0;
 813         Log_Debug("TCP", "Sending ACK for 0x%08x", Connection->NextSequenceRcv);
 814         TCP_SendPacket( Connection, &hdr, 0, NULL );
 815         //Connection->NextSequenceSend ++;
 816         Connection->LastACKSequence = Connection->NextSequenceRcv;
 817 }
 818
 819 /**
 820  * \fn Uint16 TCP_GetUnusedPort()
 821  * \brief Gets an unused port and allocates it
 822  */
 823 Uint16 TCP_GetUnusedPort()
 824 {
 825         Uint16  ret;
 826
 827         // Get Next outbound port
 828         ret = giTCP_NextOutPort++;
 829         while( gaTCP_PortBitmap[ret/32] & (1UL << (ret%32)) )
 830         {
 831                 ret ++;
 832                 giTCP_NextOutPort++;
 833                 if(giTCP_NextOutPort == 0x10000) {
 834                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 835                 }
 836         }
 837
 838         // Mark the new port as used
 839         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 840
 841         return ret;
 842 }
 843
 844 /**
 845  * \fn int TCP_AllocatePort(Uint16 Port)
 846  * \brief Marks a port as used
 847  */
 848 int TCP_AllocatePort(Uint16 Port)
 849 {
 850         // Check if the port has already been allocated
 851         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 852                 return 0;
 853
 854         // Allocate
 855         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 856
 857         return 1;
 858 }
 859
 860 /**
 861  * \fn int TCP_DeallocatePort(Uint16 Port)
 862  * \brief Marks a port as unused
 863  */
 864 int TCP_DeallocatePort(Uint16 Port)
 865 {
 866         // Check if the port has already been allocated
 867         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 868                 return 0;
 869
 870         // Allocate
 871         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 872
 873         return 1;
 874 }
 875
 876 // --- Server
 877 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 878 {
 879         tTCPListener    *srv;
 880
 881         srv = calloc( 1, sizeof(tTCPListener) );
 882
 883         if( srv == NULL ) {
 884                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 885                 return NULL;
 886         }
 887
 888         srv->Interface = Interface;
 889         srv->Port = 0;
 890         srv->NextID = 0;
 891         srv->Connections = NULL;
 892         srv->ConnectionsTail = NULL;
 893         srv->NewConnections = NULL;
 894         srv->Next = NULL;
 895         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 896         srv->Node.Size = -1;
 897         srv->Node.ImplPtr = srv;
 898         srv->Node.NumACLs = 1;
 899         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 900         srv->Node.Type = &gTCP_ServerNodeType;
 901
 902         SHORTLOCK(&glTCP_Listeners);
 903         srv->Next = gTCP_Listeners;
 904         gTCP_Listeners = srv;
 905         SHORTREL(&glTCP_Listeners);
 906
 907         return &srv->Node;
 908 }
 909
 910 /**
 911  * \brief Wait for a new connection and return the connection ID
 912  * \note Blocks until a new connection is made
 913  * \param Node  Server node
 914  * \param Pos   Position (ignored)
 915  */
 916 int TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Dest[FILENAME_MAX])
 917 {
 918         tTCPListener    *srv = Node->ImplPtr;
 919         tTCPConnection  *conn;
 920
 921         ENTER("pNode iPos", Node, Pos);
 922
 923         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 924         Semaphore_Wait( &srv->WaitingConnections, 1 );
 925
 926         SHORTLOCK(&srv->lConnections);
 927         // Increment the new list (the current connection is still on the
 928         // normal list)
 929         conn = srv->NewConnections;
 930         srv->NewConnections = conn->Next;
 931
 932         if( srv->NewConnections == NULL )
 933                 VFS_MarkAvaliable( Node, 0 );
 934
 935         SHORTREL( &srv->lConnections );
 936
 937         LOG("conn = %p", conn);
 938         LOG("srv->Connections = %p", srv->Connections);
 939         LOG("srv->NewConnections = %p", srv->NewConnections);
 940         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 941
 942         itoa(Dest, conn->Node.ImplInt, 16, 8, '0');
 943         Log_Log("TCP", "Thread %i got connection '%s'", Threads_GetTID(), Dest);
 944         LEAVE('i', 0);
 945         return 0;
 946 }
 947
 948 /**
 949  * \brief Gets a client connection node
 950  * \param Node  Server node
 951  * \param Name  Hexadecimal ID of the node
 952  */
 953 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags)
 954 {
 955         tTCPConnection  *conn;
 956         tTCPListener    *srv = Node->ImplPtr;
 957         char    tmp[9];
 958          int    id = atoi(Name);
 959
 960         ENTER("pNode sName", Node, Name);
 961
 962         // Check for a non-empty name
 963         if( Name[0] )
 964         {
 965                 // Sanity Check
 966                 itoa(tmp, id, 16, 8, '0');
 967                 if(strcmp(tmp, Name) != 0) {
 968                         LOG("'%s' != '%s' (%08x)", Name, tmp, id);
 969                         LEAVE('n');
 970                         return NULL;
 971                 }
 972
 973                 Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
 974                 Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
 975                 Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 976
 977                 // Search
 978                 SHORTLOCK( &srv->lConnections );
 979                 for(conn = srv->Connections;
 980                         conn;
 981                         conn = conn->Next)
 982                 {
 983                         LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
 984                         if(conn->Node.ImplInt == id)    break;
 985                 }
 986                 SHORTREL( &srv->lConnections );
 987
 988                 // If not found, ret NULL
 989                 if(!conn) {
 990                         LOG("Connection %i not found", id);
 991                         LEAVE('n');
 992                         return NULL;
 993                 }
 994         }
 995         // Empty Name - Check for a new connection and if it's there, open it
 996         else
 997         {
 998                 SHORTLOCK( &srv->lConnections );
 999                 conn = srv->NewConnections;
1000                 if( conn != NULL )
1001                         srv->NewConnections = conn->Next;
1002                 VFS_MarkAvaliable( Node, srv->NewConnections != NULL );
1003                 SHORTREL( &srv->lConnections );
1004                 if( !conn ) {
1005                         LOG("No new connections");
1006                         LEAVE('n');
1007                         return NULL;
1008                 }
1009         }
1010
1011         // Return node
1012         LEAVE('p', &conn->Node);
1013         return &conn->Node;
1014 }
1015
1016 /**
1017  * \brief Handle IOCtl calls
1018  */
1019 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
1020 {
1021         tTCPListener    *srv = Node->ImplPtr;
1022
1023         switch(ID)
1024         {
1025         case 4: // Get/Set Port
1026                 if(!Data)       // Get Port
1027                         return srv->Port;
1028
1029                 if(srv->Port)   // Wait, you can't CHANGE the port
1030                         return -1;
1031
1032                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
1033                         return -1;
1034
1035                 // Permissions check
1036                 if(Threads_GetUID() != 0
1037                 && *(Uint16*)Data != 0
1038                 && *(Uint16*)Data < 1024)
1039                         return -1;
1040
1041                 // TODO: Check if a port is in use
1042
1043                 // Set Port
1044                 srv->Port = *(Uint16*)Data;
1045                 if(srv->Port == 0)      // Allocate a random port
1046                         srv->Port = TCP_GetUnusedPort();
1047                 else    // Else, mark this as used
1048                         TCP_AllocatePort(srv->Port);
1049
1050                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
1051
1052                 return srv->Port;
1053         }
1054         return 0;
1055 }
1056
1057 void TCP_Server_Close(tVFS_Node *Node)
1058 {
1059         free(Node->ImplPtr);
1060 }
1061
1062 // --- Client
1063 /**
1064  * \brief Create a client node
1065  */
1066 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1067 {
1068         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
1069
1070         conn->State = TCP_ST_CLOSED;
1071         conn->Interface = Interface;
1072         conn->LocalPort = -1;
1073         conn->RemotePort = -1;
1074
1075         conn->Node.ImplPtr = conn;
1076         conn->Node.NumACLs = 1;
1077         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
1078         conn->Node.Type = &gTCP_ClientNodeType;
1079         conn->Node.BufferFull = 1;      // Cleared when connection opens
1080
1081         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
1082         #if 0
1083         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
1084         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
1085         #endif
1086
1087         #if CACHE_FUTURE_PACKETS_IN_BYTES
1088         // Future recieved data (ahead of the expected sequence number)
1089         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
1090         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
1091         #endif
1092
1093         conn->DeferredACKTimer = Time_AllocateTimer( (void(*)(void*)) TCP_INT_SendACK, conn);
1094
1095         SHORTLOCK(&glTCP_OutbountCons);
1096         conn->Next = gTCP_OutbountCons;
1097         gTCP_OutbountCons = conn;
1098         SHORTREL(&glTCP_OutbountCons);
1099
1100         return &conn->Node;
1101 }
1102
1103 /**
1104  * \brief Wait for a packet and return it
1105  * \note If \a Length is smaller than the size of the packet, the rest
1106  *       of the packet's data will be discarded.
1107  */
1108 size_t TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
1109 {
1110         tTCPConnection  *conn = Node->ImplPtr;
1111         size_t  len;
1112
1113         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1114         LOG("conn = %p {State:%i}", conn, conn->State);
1115
1116         // If the connection has been closed (state > ST_OPEN) then clear
1117         // any stale data in the buffer (until it is empty (until it is empty))
1118         if( conn->State > TCP_ST_OPEN )
1119         {
1120                 Mutex_Acquire( &conn->lRecievedPackets );
1121                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1122                 Mutex_Release( &conn->lRecievedPackets );
1123
1124                 if( len == 0 ) {
1125                         VFS_MarkAvaliable(Node, 0);
1126                         errno = 0;
1127                         LEAVE('i', -1);
1128                         return -1;
1129                 }
1130
1131                 LEAVE('i', len);
1132                 return len;
1133         }
1134
1135         // Wait
1136         {
1137                 tTime   *timeout = NULL;
1138                 tTime   timeout_zero = 0;
1139                 if( Flags & VFS_IOFLAG_NOBLOCK )
1140                         timeout = &timeout_zero;
1141                 if( !VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, timeout, "TCP_Client_Read") ) {
1142                         errno = EWOULDBLOCK;
1143                         LEAVE('i', -1);
1144                         return -1;
1145                 }
1146         }
1147
1148         // Lock list and read as much as possible (up to `Length`)
1149         Mutex_Acquire( &conn->lRecievedPackets );
1150         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1151
1152         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1153                 LOG("Marking as none avaliable (len = %i)", len);
1154                 VFS_MarkAvaliable(Node, 0);
1155         }
1156
1157         // Release the lock (we don't need it any more)
1158         Mutex_Release( &conn->lRecievedPackets );
1159
1160         LEAVE('i', len);
1161         return len;
1162 }
1163
1164 /**
1165  * \brief Send a data packet on a connection
1166  */
1167 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, const void *Data)
1168 {
1169         char    buf[sizeof(tTCPHeader)+Length];
1170         tTCPHeader      *packet = (void*)buf;
1171
1172         packet->SourcePort = htons(Connection->LocalPort);
1173         packet->DestPort = htons(Connection->RemotePort);
1174         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1175         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1176
1177         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1178         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1179         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1180
1181         memcpy(packet->Options, Data, Length);
1182
1183         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1184 #if HEXDUMP_OUTGOING
1185         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1186 #endif
1187
1188         TCP_SendPacket( Connection, packet, Length, Data );
1189
1190         Connection->NextSequenceSend += Length;
1191 }
1192
1193 /**
1194  * \brief Send some bytes on a connection
1195  */
1196 size_t TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
1197 {
1198         tTCPConnection  *conn = Node->ImplPtr;
1199         size_t  rem = Length;
1200
1201         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1202
1203 //      #if DEBUG
1204 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1205 //              Buffer, Length);
1206 //      #endif
1207
1208         // Don't allow a write to a closed connection
1209         if( conn->State > TCP_ST_OPEN ) {
1210                 VFS_MarkError(Node, 1);
1211                 errno = 0;
1212                 LEAVE('i', -1);
1213                 return -1;
1214         }
1215
1216         // Wait
1217         {
1218                 tTime   *timeout = NULL;
1219                 tTime   timeout_zero = 0;
1220                 if( Flags & VFS_IOFLAG_NOBLOCK )
1221                         timeout = &timeout_zero;
1222                 if( !VFS_SelectNode(Node, VFS_SELECT_WRITE|VFS_SELECT_ERROR, timeout, "TCP_Client_Write") ) {
1223                         errno = EWOULDBLOCK;
1224                         LEAVE('i', -1);
1225                         return -1;
1226                 }
1227         }
1228
1229         do
1230         {
1231                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1232
1233                 #if 0
1234                 // Wait for space in the buffer
1235                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1236
1237                 // Save data to buffer (and update the length read by the ammount written)
1238                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1239                 #endif
1240
1241                 // Send packet
1242                 TCP_INT_SendDataPacket(conn, len, Buffer);
1243
1244                 Buffer += len;
1245                 rem -= len;
1246         } while( rem > 0 );
1247
1248         LEAVE('i', Length);
1249         return Length;
1250 }
1251
1252 /**
1253  * \brief Open a connection to another host using TCP
1254  * \param Conn  Connection structure
1255  */
1256 void TCP_StartConnection(tTCPConnection *Conn)
1257 {
1258         tTCPHeader      hdr = {0};
1259
1260         Conn->State = TCP_ST_SYN_SENT;
1261
1262         hdr.SourcePort = htons(Conn->LocalPort);
1263         hdr.DestPort = htons(Conn->RemotePort);
1264         Conn->NextSequenceSend = rand();
1265         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1266         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1267         hdr.Flags = TCP_FLAG_SYN;
1268         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1269         hdr.Checksum = 0;       // TODO
1270
1271         TCP_SendPacket( Conn, &hdr, 0, NULL );
1272
1273         Conn->NextSequenceSend ++;
1274         Conn->State = TCP_ST_SYN_SENT;
1275
1276         return ;
1277 }
1278
1279 /**
1280  * \brief Control a client socket
1281  */
1282 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1283 {
1284         tTCPConnection  *conn = Node->ImplPtr;
1285
1286         ENTER("pNode iID pData", Node, ID, Data);
1287
1288         switch(ID)
1289         {
1290         case 4: // Get/Set local port
1291                 if(!Data)
1292                         LEAVE_RET('i', conn->LocalPort);
1293                 if(conn->State != TCP_ST_CLOSED)
1294                         LEAVE_RET('i', -1);
1295                 if(!CheckMem(Data, sizeof(Uint16)))
1296                         LEAVE_RET('i', -1);
1297
1298                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1299                         LEAVE_RET('i', -1);
1300
1301                 conn->LocalPort = *(Uint16*)Data;
1302                 LEAVE_RET('i', conn->LocalPort);
1303
1304         case 5: // Get/Set remote port
1305                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1306                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1307                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1308                 conn->RemotePort = *(Uint16*)Data;
1309                 LEAVE_RET('i', conn->RemotePort);
1310
1311         case 6: // Set Remote IP
1312                 if( conn->State != TCP_ST_CLOSED )
1313                         LEAVE_RET('i', -1);
1314                 if( conn->Interface->Type == 4 )
1315                 {
1316                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1317                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1318                 }
1319                 else if( conn->Interface->Type == 6 )
1320                 {
1321                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1322                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1323                 }
1324                 LEAVE_RET('i', 0);
1325
1326         case 7: // Connect
1327                 if(conn->LocalPort == 0xFFFF)
1328                         conn->LocalPort = TCP_GetUnusedPort();
1329                 if(conn->RemotePort == -1)
1330                         LEAVE_RET('i', 0);
1331
1332                 {
1333                         tTime   timeout = conn->Interface->TimeoutDelay;
1334
1335                         TCP_StartConnection(conn);
1336                         VFS_SelectNode(&conn->Node, VFS_SELECT_WRITE, &timeout, "TCP Connection");
1337                         if( conn->State == TCP_ST_SYN_SENT )
1338                                 LEAVE_RET('i', 0);
1339                 }
1340
1341                 LEAVE_RET('i', 1);
1342
1343         // Get recieve buffer length
1344         case 8:
1345                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1346         }
1347
1348         return 0;
1349 }
1350
1351 void TCP_Client_Close(tVFS_Node *Node)
1352 {
1353         tTCPConnection  *conn = Node->ImplPtr;
1354         tTCPHeader      packet;
1355
1356         ENTER("pNode", Node);
1357
1358         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1359         {
1360                 packet.SourcePort = htons(conn->LocalPort);
1361                 packet.DestPort = htons(conn->RemotePort);
1362                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1363                 packet.WindowSize = TCP_WINDOW_SIZE;
1364
1365                 packet.AcknowlegementNumber = 0;
1366                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1367                 packet.Flags = TCP_FLAG_FIN;
1368
1369                 TCP_SendPacket( conn, &packet, 0, NULL );
1370         }
1371
1372         switch( conn->State )
1373         {
1374         case TCP_ST_CLOSE_WAIT:
1375                 conn->State = TCP_ST_LAST_ACK;
1376                 break;
1377         case TCP_ST_OPEN:
1378                 conn->State = TCP_ST_FIN_WAIT1;
1379                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1380                 break;
1381         default:
1382                 Log_Warning("TCP", "Unhandled connection state %i in TCP_Client_Close",
1383                         conn->State);
1384                 break;
1385         }
1386
1387         Time_RemoveTimer(conn->DeferredACKTimer);
1388         Time_FreeTimer(conn->DeferredACKTimer);
1389         free(conn);
1390
1391         LEAVE('-');
1392 }
1393
1394 /**
1395  * \brief Checks if a value is between two others (after taking into account wrapping)
1396  */
1397 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1398 {
1399         if( MaxValue < 0xFFFFFFFF )
1400         {
1401                 Lower %= MaxValue + 1;
1402                 Value %= MaxValue + 1;
1403                 Higher %= MaxValue + 1;
1404         }
1405
1406         // Simple Case, no wrap ?
1407         //       Lower Value Higher
1408         // | ... + ... + ... + ... |
1409
1410         if( Lower < Higher ) {
1411                 return Lower < Value && Value < Higher;
1412         }
1413         // Higher has wrapped below lower
1414
1415         // Value > Lower ?
1416         //       Higher Lower Value
1417         // | ... +  ... + ... + ... |
1418         if( Value > Lower ) {
1419                 return 1;
1420         }
1421
1422         // Value < Higher ?
1423         //       Value Higher Lower
1424         // | ... + ... +  ... + ... |
1425         if( Value < Higher ) {
1426                 return 1;
1427         }
1428
1429         return 0;
1430 }