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 #define TCP_DEBUG       0       // Set to non-0 to enable TCP packet logging
  26
  27 // === PROTOTYPES ===
  28 void    TCP_Initialise(void);
  29 void    TCP_StartConnection(tTCPConnection *Conn);
  30 void    TCP_SendPacket(tTCPConnection *Conn, tTCPHeader *Header, size_t DataLen, const void *Data);
  31 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  32 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  33 int     TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length);
  34 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  35 void    TCP_int_SendDelayedACK(void *ConnPtr);
  36 void    TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason);
  37 Uint16  TCP_GetUnusedPort();
  38  int    TCP_AllocatePort(Uint16 Port);
  39  int    TCP_DeallocatePort(Uint16 Port);
  40 // --- Server
  41 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  42  int    TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Name[FILENAME_MAX]);
  43 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags);
  44  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  45 void    TCP_Server_Close(tVFS_Node *Node);
  46 // --- Client
  47 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  48 size_t  TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  49 size_t  TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags);
  50  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  51 void    TCP_Client_Close(tVFS_Node *Node);
  52 // --- Helpers
  53  int    WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
  54
  55 // === TEMPLATES ===
  56 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  57 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  58 tVFS_NodeType   gTCP_ServerNodeType = {
  59         .TypeName = "TCP Server",
  60         .ReadDir = TCP_Server_ReadDir,
  61         .FindDir = TCP_Server_FindDir,
  62         .IOCtl   = TCP_Server_IOCtl,
  63         .Close   = TCP_Server_Close
  64         };
  65 tVFS_NodeType   gTCP_ClientNodeType = {
  66         .TypeName = "TCP Client/Connection",
  67         .Read  = TCP_Client_Read,
  68         .Write = TCP_Client_Write,
  69         .IOCtl = TCP_Client_IOCtl,
  70         .Close = TCP_Client_Close
  71         };
  72
  73 // === GLOBALS ===
  74  int    giTCP_NumHalfopen = 0;
  75 tShortSpinlock  glTCP_Listeners;
  76 tTCPListener    *gTCP_Listeners;
  77 tShortSpinlock  glTCP_OutbountCons;
  78 tTCPConnection  *gTCP_OutbountCons;
  79 Uint32  gaTCP_PortBitmap[0x800];
  80  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  81
  82 // === CODE ===
  83 /**
  84  * \brief Initialise the TCP Layer
  85  *
  86  * Registers the client and server files and the GetPacket callback
  87  */
  88 void TCP_Initialise(void)
  89 {
  90         giTCP_NextOutPort += rand()%32;
  91         IPStack_AddFile(&gTCP_ServerFile);
  92         IPStack_AddFile(&gTCP_ClientFile);
  93         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  94         IPv6_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  95 }
  96
  97 /**
  98  * \brief Sends a packet from the specified connection, calculating the checksums
  99  * \param Conn  Connection
 100  * \param Length        Length of data
 101  * \param Data  Packet data (cast as a TCP Header)
 102  */
 103 void TCP_SendPacket( tTCPConnection *Conn, tTCPHeader *Header, size_t Length, const void *Data )
 104 {
 105         tIPStackBuffer  *buffer;
 106         Uint16  checksum[3];
 107          int    packlen = sizeof(*Header) + Length;
 108
 109         buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
 110         if( Data && Length )
 111                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
 112         IPStack_Buffer_AppendSubBuffer(buffer, sizeof(*Header), 0, Header, NULL, NULL);
 113
 114         LOG("Sending %i+%i to %s:%i", sizeof(*Header), Length,
 115                 IPStack_PrintAddress(Conn->Interface->Type, &Conn->RemoteIP),
 116                 Conn->RemotePort
 117                 );
 118
 119         Header->Checksum = 0;
 120         checksum[1] = htons( ~IPv4_Checksum(Header, sizeof(tTCPHeader)) );
 121         checksum[2] = htons( ~IPv4_Checksum(Data, Length) );
 122
 123         // TODO: Fragment packet
 124
 125         switch( Conn->Interface->Type )
 126         {
 127         case 4:
 128                 // Get IPv4 pseudo-header checksum
 129                 {
 130                         Uint32  buf[3];
 131                         buf[0] = ((tIPv4*)Conn->Interface->Address)->L;
 132                         buf[1] = Conn->RemoteIP.v4.L;
 133                         buf[2] = (htons(packlen)<<16) | (6<<8) | 0;
 134                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 135                 }
 136                 // - Combine checksums
 137                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );
 138                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, buffer);
 139                 break;
 140
 141         case 6:
 142                 // Append IPv6 Pseudo Header
 143                 {
 144                         Uint32  buf[4+4+1+1];
 145                         memcpy(buf, Conn->Interface->Address, 16);
 146                         memcpy(&buf[4], &Conn->RemoteIP, 16);
 147                         buf[8] = htonl(packlen);
 148                         buf[9] = htonl(6);
 149                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 150                 }
 151                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );  // Combine the two
 152                 IPv6_SendPacket(Conn->Interface, Conn->RemoteIP.v6, IP4PROT_TCP, Length, Data);
 153                 break;
 154         }
 155 }
 156
 157 /**
 158  * \brief Handles a packet from the IP Layer
 159  * \param Interface     Interface the packet arrived from
 160  * \param Address       Pointer to the addres structure
 161  * \param Length        Size of packet in bytes
 162  * \param Buffer        Packet data
 163  */
 164 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 165 {
 166         tTCPHeader      *hdr = Buffer;
 167         tTCPListener    *srv;
 168         tTCPConnection  *conn;
 169
 170         #if TCP_DEBUG
 171         Log_Log("TCP", "TCP_GetPacket: <Local>:%i from [%s]:%i, Flags = %s%s%s%s%s%s%s%s",
 172                 ntohs(hdr->DestPort),
 173                 IPStack_PrintAddress(Interface->Type, Address),
 174                 ntohs(hdr->SourcePort),
 175                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
 176                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
 177                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
 178                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
 179                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
 180                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
 181                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
 182                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
 183                 );
 184         #endif
 185
 186         if( Length > (hdr->DataOffset >> 4)*4 )
 187         {
 188                 LOG("SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 189 #if HEXDUMP_INCOMING
 190                 Debug_HexDump(
 191                         "TCP_GetPacket: Packet Data = ",
 192                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 193                         Length - (hdr->DataOffset >> 4)*4
 194                         );
 195 #endif
 196         }
 197
 198         // Check Servers
 199         for( srv = gTCP_Listeners; srv; srv = srv->Next )
 200         {
 201                 // Check if the server is active
 202                 if(srv->Port == 0)      continue;
 203                 // Check the interface
 204                 if(srv->Interface && srv->Interface != Interface)       continue;
 205                 // Check the destination port
 206                 if(srv->Port != htons(hdr->DestPort))   continue;
 207
 208                 Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 209                 // Is this in an established connection?
 210                 for( conn = srv->Connections; conn; conn = conn->Next )
 211                 {
 212                         // Check that it is coming in on the same interface
 213                         if(conn->Interface != Interface)        continue;
 214
 215                         // Check Source Port
 216                         Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 217                                 conn->RemotePort, ntohs(hdr->SourcePort));
 218                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 219
 220                         // Check Source IP
 221                         Log_Debug("TCP", "TCP_GetPacket: conn->RemoteIP(%s)",
 222                                 IPStack_PrintAddress(conn->Interface->Type, &conn->RemoteIP));
 223                         Log_Debug("TCP", "                == Address(%s)",
 224                                 IPStack_PrintAddress(conn->Interface->Type, Address));
 225                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
 226                                 continue ;
 227
 228                         Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 229                         // We have a response!
 230                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 231
 232                         return;
 233                 }
 234
 235                 Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 236                 // Open a new connection (well, check that it's a SYN)
 237                 if(hdr->Flags != TCP_FLAG_SYN) {
 238                         Log_Log("TCP", "TCP_GetPacket: Packet is not a SYN");
 239                         return ;
 240                 }
 241
 242                 // TODO: Check for halfopen max
 243
 244                 conn = calloc(1, sizeof(tTCPConnection));
 245                 conn->State = TCP_ST_SYN_RCVD;
 246                 conn->LocalPort = srv->Port;
 247                 conn->RemotePort = ntohs(hdr->SourcePort);
 248                 conn->Interface = Interface;
 249
 250                 switch(Interface->Type)
 251                 {
 252                 case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 253                 case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 254                 }
 255
 256                 conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 257
 258                 conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 259                 conn->NextSequenceSend = rand();
 260
 261                 // Create node
 262                 conn->Node.NumACLs = 1;
 263                 conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 264                 conn->Node.ImplPtr = conn;
 265                 conn->Node.ImplInt = srv->NextID ++;
 266                 conn->Node.Type = &gTCP_ClientNodeType; // TODO: Special type for the server end?
 267
 268                 // Hmm... Theoretically, this lock will never have to wait,
 269                 // as the interface is locked to the watching thread, and this
 270                 // runs in the watching thread. But, it's a good idea to have
 271                 // it, just in case
 272                 // Oh, wait, there is a case where a wildcard can be used
 273                 // (srv->Interface == NULL) so having the lock is a good idea
 274                 SHORTLOCK(&srv->lConnections);
 275                 if( !srv->Connections )
 276                         srv->Connections = conn;
 277                 else
 278                         srv->ConnectionsTail->Next = conn;
 279                 srv->ConnectionsTail = conn;
 280                 if(!srv->NewConnections)
 281                         srv->NewConnections = conn;
 282                 VFS_MarkAvaliable( &srv->Node, 1 );
 283                 SHORTREL(&srv->lConnections);
 284                 Semaphore_Signal(&srv->WaitingConnections, 1);
 285
 286                 // Send the SYN ACK
 287                 hdr->Flags |= TCP_FLAG_ACK;
 288                 hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 289                 hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 290                 hdr->DestPort = hdr->SourcePort;
 291                 hdr->SourcePort = htons(srv->Port);
 292                 hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 293                 TCP_SendPacket( conn, hdr, 0, NULL );
 294                 conn->NextSequenceSend ++;
 295                 return ;
 296         }
 297
 298         // Check Open Connections
 299         {
 300                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 301                 {
 302                         // Check that it is coming in on the same interface
 303                         if(conn->Interface != Interface)        continue;
 304
 305                         // Check Source Port
 306                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 307
 308                         // Check Source IP
 309                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 310                                 continue;
 311                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 312                                 continue;
 313
 314                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 315                         return ;
 316                 }
 317         }
 318
 319         Log_Log("TCP", "TCP_GetPacket: No Match");
 320 }
 321
 322 /**
 323  * \brief Handles a packet sent to a specific connection
 324  * \param Connection    TCP Connection pointer
 325  * \param Header        TCP Packet pointer
 326  * \param Length        Length of the packet
 327  */
 328 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 329 {
 330          int    dataLen;
 331         Uint32  sequence_num;
 332
 333         // Silently drop once finished
 334         // TODO: Check if this needs to be here
 335         if( Connection->State == TCP_ST_FINISHED ) {
 336                 Log_Log("TCP", "Packet ignored - connection finnished");
 337                 return ;
 338         }
 339
 340         // Syncronise sequence values
 341         if(Header->Flags & TCP_FLAG_SYN) {
 342                 // TODO: What if the packet also has data?
 343                 if( Connection->LastACKSequence != Connection->NextSequenceRcv )
 344                         TCP_INT_SendACK(Connection, "SYN");
 345                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
 346                 Connection->LastACKSequence = Connection->NextSequenceRcv;
 347         }
 348
 349         // Ackowledge a sent packet
 350         if(Header->Flags & TCP_FLAG_ACK) {
 351                 // TODO: Process an ACKed Packet
 352                 LOG("Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 353         }
 354
 355         // Get length of data
 356         dataLen = Length - (Header->DataOffset>>4)*4;
 357         LOG("dataLen = %i", dataLen);
 358         #if TCP_DEBUG
 359         Log_Debug("TCP", "State %i, dataLen = %x", Connection->State, dataLen);
 360         #endif
 361
 362         //
 363         // State Machine
 364         //
 365         switch( Connection->State )
 366         {
 367         // Pre-init connection?
 368         case TCP_ST_CLOSED:
 369                 Log_Log("TCP", "Packets to a closed connection?!");
 370                 break;
 371
 372         // --- Init States ---
 373         // SYN sent, expecting SYN-ACK Connection Opening
 374         case TCP_ST_SYN_SENT:
 375                 if( Header->Flags & TCP_FLAG_SYN )
 376                 {
 377                         Connection->NextSequenceRcv ++;
 378
 379                         if( Header->Flags & TCP_FLAG_ACK )
 380                         {
 381                                 Log_Log("TCP", "ACKing SYN-ACK");
 382                                 Connection->State = TCP_ST_OPEN;
 383                                 VFS_MarkFull(&Connection->Node, 0);
 384                         }
 385                         else
 386                         {
 387                                 Log_Log("TCP", "ACKing SYN");
 388                                 Connection->State = TCP_ST_SYN_RCVD;
 389                         }
 390                         Header->DestPort = Header->SourcePort;
 391                         Header->SourcePort = htons(Connection->LocalPort);
 392                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 393                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 394                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 395                         Header->Flags = TCP_FLAG_ACK;
 396                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 397                         TCP_SendPacket( Connection, Header, 0, NULL );
 398                 }
 399                 break;
 400
 401         // SYN-ACK sent, expecting ACK
 402         case TCP_ST_SYN_RCVD:
 403                 if( Header->Flags & TCP_FLAG_ACK )
 404                 {
 405                         // TODO: Handle max half-open limit
 406                         Log_Log("TCP", "Connection fully opened");
 407                         Connection->State = TCP_ST_OPEN;
 408                         VFS_MarkFull(&Connection->Node, 0);
 409                 }
 410                 break;
 411
 412         // --- Established State ---
 413         case TCP_ST_OPEN:
 414                 // - Handle State changes
 415                 //
 416                 if( Header->Flags & TCP_FLAG_FIN ) {
 417                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
 418                         VFS_MarkError(&Connection->Node, 1);
 419                         Connection->State = TCP_ST_CLOSE_WAIT;
 420 //                      Header->Flags &= ~TCP_FLAG_FIN;
 421                         // CLOSE WAIT requires the client to close (or does it?)
 422                         #if 0
 423
 424                         #endif
 425                 }
 426
 427                 // Check for an empty packet
 428                 if(dataLen == 0) {
 429                         if( Header->Flags == TCP_FLAG_ACK )
 430                         {
 431                                 Log_Log("TCP", "ACK only packet");
 432                                 return ;
 433                         }
 434                         Connection->NextSequenceRcv ++; // TODO: Is this right? (empty packet counts as one byte)
 435                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
 436                         TCP_INT_SendACK(Connection, "Empty");
 437                         #if 0
 438                         Header->DestPort = Header->SourcePort;
 439                         Header->SourcePort = htons(Connection->LocalPort);
 440                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 441                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 442                         Header->Flags |= TCP_FLAG_ACK;
 443                         TCP_SendPacket( Connection, Header, 0, NULL );
 444                         #endif
 445                         return ;
 446                 }
 447
 448                 // NOTES:
 449                 // Flags
 450                 //    PSH - Has Data?
 451                 // /NOTES
 452
 453                 sequence_num = ntohl(Header->SequenceNumber);
 454
 455                 LOG("0x%08x <= 0x%08x < 0x%08x",
 456                         Connection->NextSequenceRcv,
 457                         ntohl(Header->SequenceNumber),
 458                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
 459                         );
 460
 461                 // Is this packet the next expected packet?
 462                 if( sequence_num == Connection->NextSequenceRcv )
 463                 {
 464                          int    rv;
 465                         // Ooh, Goodie! Add it to the recieved list
 466                         rv = TCP_INT_AppendRecieved(Connection,
 467                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 468                                 dataLen
 469                                 );
 470                         if(rv != 0) {
 471                                 Log_Notice("TCP", "TCP_INT_AppendRecieved rv %i", rv);
 472                                 break;
 473                         }
 474                         LOG("0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 475                         Connection->NextSequenceRcv += dataLen;
 476
 477                         // TODO: This should be moved out of the watcher thread,
 478                         // so that a single lost packet on one connection doesn't cause
 479                         // all connections on the interface to lag.
 480                         // - Meh, no real issue, as the cache shouldn't be that large
 481                         TCP_INT_UpdateRecievedFromFuture(Connection);
 482
 483                         #if 1
 484                         // - Only send an ACK if we've had a burst
 485                         if( Connection->NextSequenceRcv > (Uint32)(TCP_DACK_THRESHOLD + Connection->LastACKSequence) )
 486                         {
 487                                 TCP_INT_SendACK(Connection, "DACK Burst");
 488                                 // - Extend TCP deferred ACK timer
 489                                 Time_RemoveTimer(Connection->DeferredACKTimer);
 490                         }
 491                         // - Schedule the deferred ACK timer (if already scheduled, this is a NOP)
 492                         Time_ScheduleTimer(Connection->DeferredACKTimer, TCP_DACK_TIMEOUT);
 493                         #else
 494                         TCP_INT_SendACK(Connection, "RX");
 495                         #endif
 496                 }
 497                 // Check if the packet is in window
 498                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 499                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 500                 {
 501                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 502                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 503                         Uint32  index;
 504                          int    i;
 505
 506                         index = sequence_num % TCP_WINDOW_SIZE;
 507                         for( i = 0; i < dataLen; i ++ )
 508                         {
 509                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
 510                                 Connection->FuturePacketData[index] = dataptr[i];
 511                                 // Do a wrap increment
 512                                 index ++;
 513                                 if(index == TCP_WINDOW_SIZE)    index = 0;
 514                         }
 515                         #else
 516                         tTCPStoredPacket        *pkt, *tmp, *prev = NULL;
 517
 518                         // Allocate and fill cached packet
 519                         pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
 520                         pkt->Next = NULL;
 521                         pkt->Sequence = ntohl(Header->SequenceNumber);
 522                         pkt->Length = dataLen;
 523                         memcpy(pkt->Data, dataptr, dataLen);
 524
 525                         Log_Log("TCP", "We missed a packet, caching",
 526                                 pkt->Sequence, Connection->NextSequenceRcv);
 527
 528                         // No? Well, let's cache it and look at it later
 529                         SHORTLOCK( &Connection->lFuturePackets );
 530                         for(tmp = Connection->FuturePackets;
 531                                 tmp;
 532                                 prev = tmp, tmp = tmp->Next)
 533                         {
 534                                 if(tmp->Sequence >= pkt->Sequence)      break;
 535                         }
 536
 537                         // Add if before first, or sequences don't match
 538                         if( !tmp || tmp->Sequence != pkt->Sequence )
 539                         {
 540                                 if(prev)
 541                                         prev->Next = pkt;
 542                                 else
 543                                         Connection->FuturePackets = pkt;
 544                                 pkt->Next = tmp;
 545                         }
 546                         // Replace if larger
 547                         else if(pkt->Length > tmp->Length)
 548                         {
 549                                 if(prev)
 550                                         prev->Next = pkt;
 551                                 pkt->Next = tmp->Next;
 552                                 free(tmp);
 553                         }
 554                         else
 555                         {
 556                                 free(pkt);      // TODO: Find some way to remove this
 557                         }
 558                         SHORTREL( &Connection->lFuturePackets );
 559                         #endif
 560                 }
 561                 // Badly out of sequence packet
 562                 else
 563                 {
 564                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
 565                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
 566                         // Spec says we should send an empty ACK with the current state
 567                         TCP_INT_SendACK(Connection, "Bad Seq");
 568                 }
 569                 break;
 570
 571         // --- Remote close states
 572         case TCP_ST_CLOSE_WAIT:
 573
 574                 // Ignore everything, CLOSE_WAIT is terminated by the client
 575                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
 576
 577                 break;
 578
 579         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
 580         case TCP_ST_LAST_ACK:
 581                 if( Header->Flags & TCP_FLAG_ACK )
 582                 {
 583                         Connection->State = TCP_ST_FINISHED;    // Connection completed
 584                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
 585                         // TODO: Destrory the TCB
 586                 }
 587                 break;
 588
 589         // --- Local close States
 590         case TCP_ST_FIN_WAIT1:
 591                 if( Header->Flags & TCP_FLAG_FIN )
 592                 {
 593                         Connection->State = TCP_ST_CLOSING;
 594                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
 595                         VFS_MarkError(&Connection->Node, 1);
 596
 597                         // ACK Packet
 598                         Header->DestPort = Header->SourcePort;
 599                         Header->SourcePort = htons(Connection->LocalPort);
 600                         Header->AcknowlegementNumber = Header->SequenceNumber;
 601                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 602                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 603                         Header->Flags = TCP_FLAG_ACK;
 604                         TCP_SendPacket( Connection, Header, 0, NULL );
 605                         break ;
 606                 }
 607
 608                 // TODO: Make sure that the packet is actually ACKing the FIN
 609                 if( Header->Flags & TCP_FLAG_ACK )
 610                 {
 611                         Connection->State = TCP_ST_FIN_WAIT2;
 612                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
 613                         VFS_MarkError(&Connection->Node, 1);
 614                         return ;
 615                 }
 616                 break;
 617
 618         case TCP_ST_FIN_WAIT2:
 619                 if( Header->Flags & TCP_FLAG_FIN )
 620                 {
 621                         Connection->State = TCP_ST_TIME_WAIT;
 622                         Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
 623                         // Send ACK
 624                         Header->DestPort = Header->SourcePort;
 625                         Header->SourcePort = htons(Connection->LocalPort);
 626                         Header->AcknowlegementNumber = Header->SequenceNumber;
 627                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 628                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 629                         Header->Flags = TCP_FLAG_ACK;
 630                         TCP_SendPacket( Connection, Header, 0, NULL );
 631                 }
 632                 break;
 633
 634         case TCP_ST_CLOSING:
 635                 // TODO: Make sure that the packet is actually ACKing the FIN
 636                 if( Header->Flags & TCP_FLAG_ACK )
 637                 {
 638                         Connection->State = TCP_ST_TIME_WAIT;
 639                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
 640                         VFS_MarkError(&Connection->Node, 1);
 641                         return ;
 642                 }
 643                 break;
 644
 645         // --- Closed (or near closed) states) ---
 646         case TCP_ST_TIME_WAIT:
 647                 Log_Log("TCP", "Packets on Time-Wait, ignored");
 648                 break;
 649
 650         case TCP_ST_FINISHED:
 651                 Log_Log("TCP", "Packets when CLOSED, ignoring");
 652                 break;
 653
 654         //default:
 655         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
 656         //      break;
 657         }
 658
 659 }
 660
 661 /**
 662  * \brief Appends a packet to the recieved list
 663  * \param Connection    Connection structure
 664  * \param Data  Packet contents
 665  * \param Length        Length of \a Data
 666  */
 667 int TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
 668 {
 669         Mutex_Acquire( &Connection->lRecievedPackets );
 670
 671         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
 672         {
 673                 VFS_MarkAvaliable(&Connection->Node, 1);
 674                 Log_Error("TCP", "Buffer filled, packet dropped (:%i) - %i + %i > %i",
 675                         Connection->LocalPort, Connection->RecievedBuffer->Length, Length,
 676                         Connection->RecievedBuffer->Space
 677                         );
 678                 Mutex_Release( &Connection->lRecievedPackets );
 679                 return 1;
 680         }
 681
 682         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
 683
 684         VFS_MarkAvaliable(&Connection->Node, 1);
 685
 686         Mutex_Release( &Connection->lRecievedPackets );
 687         return 0;
 688 }
 689
 690 /**
 691  * \brief Updates the connections recieved list from the future list
 692  * \param Connection    Connection structure
 693  *
 694  * Updates the recieved packets list with packets from the future (out
 695  * of order) packets list that are now able to be added in direct
 696  * sequence.
 697  */
 698 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 699 {
 700         #if CACHE_FUTURE_PACKETS_IN_BYTES
 701          int    i, length = 0;
 702         Uint32  index;
 703
 704         // Calculate length of contiguous bytes
 705         length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 706         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 707         for( i = 0; i < length; i ++ )
 708         {
 709                 if( Connection->FuturePacketValidBytes[i / 8] == 0xFF ) {
 710                         i += 7; index += 7;
 711                         continue;
 712                 }
 713                 else if( !(Connection->FuturePacketValidBytes[i / 8] & (1 << (i%8))) )
 714                         break;
 715
 716                 index ++;
 717                 if(index > TCP_WINDOW_SIZE)
 718                         index -= TCP_WINDOW_SIZE;
 719         }
 720         length = i;
 721
 722         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 723
 724         // Write data to to the ring buffer
 725         if( TCP_WINDOW_SIZE - index > length )
 726         {
 727                 // Simple case
 728                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 729         }
 730         else
 731         {
 732                  int    endLen = TCP_WINDOW_SIZE - index;
 733                 // 2-part case
 734                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 735                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 736         }
 737
 738         // Mark (now saved) bytes as invalid
 739         // - Align index
 740         while(index % 8 && length)
 741         {
 742                 Connection->FuturePacketData[index] = 0;
 743                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 744                 index ++;
 745                 if(index > TCP_WINDOW_SIZE)
 746                         index -= TCP_WINDOW_SIZE;
 747                 length --;
 748         }
 749         while( length > 7 )
 750         {
 751                 Connection->FuturePacketData[index] = 0;
 752                 Connection->FuturePacketValidBytes[index/8] = 0;
 753                 length -= 8;
 754                 index += 8;
 755                 if(index > TCP_WINDOW_SIZE)
 756                         index -= TCP_WINDOW_SIZE;
 757         }
 758         while(length)
 759         {
 760                 Connection->FuturePacketData[index] = 0;
 761                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 762                 index ++;
 763                 if(index > TCP_WINDOW_SIZE)
 764                         index -= TCP_WINDOW_SIZE;
 765                 length --;
 766         }
 767
 768         #else
 769         tTCPStoredPacket        *pkt;
 770         for(;;)
 771         {
 772                 SHORTLOCK( &Connection->lFuturePackets );
 773
 774                 // Clear out duplicates from cache
 775                 // - If a packet has just been recieved, and it is expected, then
 776                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 777                 //   packets in cache that are smaller than the next expected
 778                 //   are now defunct.
 779                 pkt = Connection->FuturePackets;
 780                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 781                 {
 782                         tTCPStoredPacket        *next = pkt->Next;
 783                         free(pkt);
 784                         pkt = next;
 785                 }
 786
 787                 // If there's no packets left in cache, stop looking
 788                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 789                         SHORTREL( &Connection->lFuturePackets );
 790                         return;
 791                 }
 792
 793                 // Delete packet from future list
 794                 Connection->FuturePackets = pkt->Next;
 795
 796                 // Release list
 797                 SHORTREL( &Connection->lFuturePackets );
 798
 799                 // Looks like we found one
 800                 TCP_INT_AppendRecieved(Connection, pkt);
 801                 Connection->NextSequenceRcv += pkt->Length;
 802                 free(pkt);
 803         }
 804         #endif
 805 }
 806
 807 void TCP_int_SendDelayedACK(void *ConnPtr)
 808 {
 809         TCP_INT_SendACK(ConnPtr, "DACK Timeout");
 810 }
 811
 812 void TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason)
 813 {
 814         tTCPHeader      hdr;
 815         // ACK Packet
 816         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
 817         hdr.DestPort = htons(Connection->RemotePort);
 818         hdr.SourcePort = htons(Connection->LocalPort);
 819         hdr.AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 820         hdr.SequenceNumber = htonl(Connection->NextSequenceSend);
 821         hdr.WindowSize = htons(TCP_WINDOW_SIZE);
 822         hdr.Flags = TCP_FLAG_ACK;       // TODO: Determine if SYN is wanted too
 823         hdr.Checksum = 0;       // TODO: Checksum
 824         hdr.UrgentPointer = 0;
 825         Log_Debug("TCP", "Sending ACK for 0x%08x (%s)", Connection->NextSequenceRcv, Reason);
 826         TCP_SendPacket( Connection, &hdr, 0, NULL );
 827         //Connection->NextSequenceSend ++;
 828         Connection->LastACKSequence = Connection->NextSequenceRcv;
 829 }
 830
 831 /**
 832  * \fn Uint16 TCP_GetUnusedPort()
 833  * \brief Gets an unused port and allocates it
 834  */
 835 Uint16 TCP_GetUnusedPort()
 836 {
 837         Uint16  ret;
 838
 839         // Get Next outbound port
 840         ret = giTCP_NextOutPort++;
 841         while( gaTCP_PortBitmap[ret/32] & (1UL << (ret%32)) )
 842         {
 843                 ret ++;
 844                 giTCP_NextOutPort++;
 845                 if(giTCP_NextOutPort == 0x10000) {
 846                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 847                 }
 848         }
 849
 850         // Mark the new port as used
 851         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 852
 853         return ret;
 854 }
 855
 856 /**
 857  * \fn int TCP_AllocatePort(Uint16 Port)
 858  * \brief Marks a port as used
 859  */
 860 int TCP_AllocatePort(Uint16 Port)
 861 {
 862         // Check if the port has already been allocated
 863         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 864                 return 0;
 865
 866         // Allocate
 867         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 868
 869         return 1;
 870 }
 871
 872 /**
 873  * \fn int TCP_DeallocatePort(Uint16 Port)
 874  * \brief Marks a port as unused
 875  */
 876 int TCP_DeallocatePort(Uint16 Port)
 877 {
 878         // Check if the port has already been allocated
 879         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 880                 return 0;
 881
 882         // Allocate
 883         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 884
 885         return 1;
 886 }
 887
 888 // --- Server
 889 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 890 {
 891         tTCPListener    *srv;
 892
 893         srv = calloc( 1, sizeof(tTCPListener) );
 894
 895         if( srv == NULL ) {
 896                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 897                 return NULL;
 898         }
 899
 900         srv->Interface = Interface;
 901         srv->Port = 0;
 902         srv->NextID = 0;
 903         srv->Connections = NULL;
 904         srv->ConnectionsTail = NULL;
 905         srv->NewConnections = NULL;
 906         srv->Next = NULL;
 907         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 908         srv->Node.Size = -1;
 909         srv->Node.ImplPtr = srv;
 910         srv->Node.NumACLs = 1;
 911         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 912         srv->Node.Type = &gTCP_ServerNodeType;
 913
 914         SHORTLOCK(&glTCP_Listeners);
 915         srv->Next = gTCP_Listeners;
 916         gTCP_Listeners = srv;
 917         SHORTREL(&glTCP_Listeners);
 918
 919         return &srv->Node;
 920 }
 921
 922 /**
 923  * \brief Wait for a new connection and return the connection ID
 924  * \note Blocks until a new connection is made
 925  * \param Node  Server node
 926  * \param Pos   Position (ignored)
 927  */
 928 int TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Dest[FILENAME_MAX])
 929 {
 930         tTCPListener    *srv = Node->ImplPtr;
 931         tTCPConnection  *conn;
 932
 933         ENTER("pNode iPos", Node, Pos);
 934
 935         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 936         Semaphore_Wait( &srv->WaitingConnections, 1 );
 937
 938         SHORTLOCK(&srv->lConnections);
 939         // Increment the new list (the current connection is still on the
 940         // normal list)
 941         conn = srv->NewConnections;
 942         srv->NewConnections = conn->Next;
 943
 944         if( srv->NewConnections == NULL )
 945                 VFS_MarkAvaliable( Node, 0 );
 946
 947         SHORTREL( &srv->lConnections );
 948
 949         LOG("conn = %p", conn);
 950         LOG("srv->Connections = %p", srv->Connections);
 951         LOG("srv->NewConnections = %p", srv->NewConnections);
 952         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 953
 954         itoa(Dest, conn->Node.ImplInt, 16, 8, '0');
 955         Log_Log("TCP", "Thread %i got connection '%s'", Threads_GetTID(), Dest);
 956         LEAVE('i', 0);
 957         return 0;
 958 }
 959
 960 /**
 961  * \brief Gets a client connection node
 962  * \param Node  Server node
 963  * \param Name  Hexadecimal ID of the node
 964  */
 965 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags)
 966 {
 967         tTCPConnection  *conn;
 968         tTCPListener    *srv = Node->ImplPtr;
 969         char    tmp[9];
 970          int    id = atoi(Name);
 971
 972         ENTER("pNode sName", Node, Name);
 973
 974         // Check for a non-empty name
 975         if( Name[0] )
 976         {
 977                 // Sanity Check
 978                 itoa(tmp, id, 16, 8, '0');
 979                 if(strcmp(tmp, Name) != 0) {
 980                         LOG("'%s' != '%s' (%08x)", Name, tmp, id);
 981                         LEAVE('n');
 982                         return NULL;
 983                 }
 984
 985                 Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
 986                 Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
 987                 Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 988
 989                 // Search
 990                 SHORTLOCK( &srv->lConnections );
 991                 for(conn = srv->Connections;
 992                         conn;
 993                         conn = conn->Next)
 994                 {
 995                         LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
 996                         if(conn->Node.ImplInt == id)    break;
 997                 }
 998                 SHORTREL( &srv->lConnections );
 999
1000                 // If not found, ret NULL
1001                 if(!conn) {
1002                         LOG("Connection %i not found", id);
1003                         LEAVE('n');
1004                         return NULL;
1005                 }
1006         }
1007         // Empty Name - Check for a new connection and if it's there, open it
1008         else
1009         {
1010                 SHORTLOCK( &srv->lConnections );
1011                 conn = srv->NewConnections;
1012                 if( conn != NULL )
1013                         srv->NewConnections = conn->Next;
1014                 VFS_MarkAvaliable( Node, srv->NewConnections != NULL );
1015                 SHORTREL( &srv->lConnections );
1016                 if( !conn ) {
1017                         LOG("No new connections");
1018                         LEAVE('n');
1019                         return NULL;
1020                 }
1021         }
1022
1023         // Return node
1024         LEAVE('p', &conn->Node);
1025         return &conn->Node;
1026 }
1027
1028 /**
1029  * \brief Handle IOCtl calls
1030  */
1031 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
1032 {
1033         tTCPListener    *srv = Node->ImplPtr;
1034
1035         switch(ID)
1036         {
1037         case 4: // Get/Set Port
1038                 if(!Data)       // Get Port
1039                         return srv->Port;
1040
1041                 if(srv->Port)   // Wait, you can't CHANGE the port
1042                         return -1;
1043
1044                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
1045                         return -1;
1046
1047                 // Permissions check
1048                 if(Threads_GetUID() != 0
1049                 && *(Uint16*)Data != 0
1050                 && *(Uint16*)Data < 1024)
1051                         return -1;
1052
1053                 // TODO: Check if a port is in use
1054
1055                 // Set Port
1056                 srv->Port = *(Uint16*)Data;
1057                 if(srv->Port == 0)      // Allocate a random port
1058                         srv->Port = TCP_GetUnusedPort();
1059                 else    // Else, mark this as used
1060                         TCP_AllocatePort(srv->Port);
1061
1062                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
1063
1064                 return srv->Port;
1065         }
1066         return 0;
1067 }
1068
1069 void TCP_Server_Close(tVFS_Node *Node)
1070 {
1071         free(Node->ImplPtr);
1072 }
1073
1074 // --- Client
1075 /**
1076  * \brief Create a client node
1077  */
1078 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1079 {
1080         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
1081
1082         conn->State = TCP_ST_CLOSED;
1083         conn->Interface = Interface;
1084         conn->LocalPort = -1;
1085         conn->RemotePort = -1;
1086
1087         conn->Node.ReferenceCount = 1;
1088         conn->Node.ImplPtr = conn;
1089         conn->Node.NumACLs = 1;
1090         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
1091         conn->Node.Type = &gTCP_ClientNodeType;
1092         conn->Node.BufferFull = 1;      // Cleared when connection opens
1093
1094         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
1095         #if 0
1096         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
1097         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
1098         #endif
1099
1100         #if CACHE_FUTURE_PACKETS_IN_BYTES
1101         // Future recieved data (ahead of the expected sequence number)
1102         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
1103         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
1104         #endif
1105
1106         conn->DeferredACKTimer = Time_AllocateTimer( TCP_int_SendDelayedACK, conn);
1107
1108         SHORTLOCK(&glTCP_OutbountCons);
1109         conn->Next = gTCP_OutbountCons;
1110         gTCP_OutbountCons = conn;
1111         SHORTREL(&glTCP_OutbountCons);
1112
1113         return &conn->Node;
1114 }
1115
1116 /**
1117  * \brief Wait for a packet and return it
1118  * \note If \a Length is smaller than the size of the packet, the rest
1119  *       of the packet's data will be discarded.
1120  */
1121 size_t TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
1122 {
1123         tTCPConnection  *conn = Node->ImplPtr;
1124         size_t  len;
1125
1126         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1127         LOG("conn = %p {State:%i}", conn, conn->State);
1128
1129         // If the connection has been closed (state > ST_OPEN) then clear
1130         // any stale data in the buffer (until it is empty (until it is empty))
1131         if( conn->State > TCP_ST_OPEN )
1132         {
1133                 Mutex_Acquire( &conn->lRecievedPackets );
1134                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1135                 Mutex_Release( &conn->lRecievedPackets );
1136
1137                 if( len == 0 ) {
1138                         VFS_MarkAvaliable(Node, 0);
1139                         errno = 0;
1140                         LEAVE('i', -1);
1141                         return -1;
1142                 }
1143
1144                 LEAVE('i', len);
1145                 return len;
1146         }
1147
1148         // Wait
1149         {
1150                 tTime   *timeout = NULL;
1151                 tTime   timeout_zero = 0;
1152                 if( Flags & VFS_IOFLAG_NOBLOCK )
1153                         timeout = &timeout_zero;
1154                 if( !VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, timeout, "TCP_Client_Read") ) {
1155                         errno = EWOULDBLOCK;
1156                         LEAVE('i', -1);
1157                         return -1;
1158                 }
1159         }
1160
1161         // Lock list and read as much as possible (up to `Length`)
1162         Mutex_Acquire( &conn->lRecievedPackets );
1163         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1164
1165         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1166                 LOG("Marking as none avaliable (len = %i)", len);
1167                 VFS_MarkAvaliable(Node, 0);
1168         }
1169
1170         // Release the lock (we don't need it any more)
1171         Mutex_Release( &conn->lRecievedPackets );
1172
1173         LEAVE('i', len);
1174         return len;
1175 }
1176
1177 /**
1178  * \brief Send a data packet on a connection
1179  */
1180 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, const void *Data)
1181 {
1182         char    buf[sizeof(tTCPHeader)+Length];
1183         tTCPHeader      *packet = (void*)buf;
1184
1185         packet->SourcePort = htons(Connection->LocalPort);
1186         packet->DestPort = htons(Connection->RemotePort);
1187         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1188         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1189
1190         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1191         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1192         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1193
1194         memcpy(packet->Options, Data, Length);
1195
1196         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1197 #if HEXDUMP_OUTGOING
1198         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1199 #endif
1200
1201         TCP_SendPacket( Connection, packet, Length, Data );
1202
1203         Connection->NextSequenceSend += Length;
1204 }
1205
1206 /**
1207  * \brief Send some bytes on a connection
1208  */
1209 size_t TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
1210 {
1211         tTCPConnection  *conn = Node->ImplPtr;
1212         size_t  rem = Length;
1213
1214         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1215
1216 //      #if DEBUG
1217 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1218 //              Buffer, Length);
1219 //      #endif
1220
1221         // Don't allow a write to a closed connection
1222         if( conn->State > TCP_ST_OPEN ) {
1223                 VFS_MarkError(Node, 1);
1224                 errno = 0;
1225                 LEAVE('i', -1);
1226                 return -1;
1227         }
1228
1229         // Wait
1230         {
1231                 tTime   *timeout = NULL;
1232                 tTime   timeout_zero = 0;
1233                 if( Flags & VFS_IOFLAG_NOBLOCK )
1234                         timeout = &timeout_zero;
1235                 if( !VFS_SelectNode(Node, VFS_SELECT_WRITE|VFS_SELECT_ERROR, timeout, "TCP_Client_Write") ) {
1236                         errno = EWOULDBLOCK;
1237                         LEAVE('i', -1);
1238                         return -1;
1239                 }
1240         }
1241
1242         do
1243         {
1244                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1245
1246                 #if 0
1247                 // Wait for space in the buffer
1248                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1249
1250                 // Save data to buffer (and update the length read by the ammount written)
1251                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1252                 #endif
1253
1254                 // Send packet
1255                 TCP_INT_SendDataPacket(conn, len, Buffer);
1256
1257                 Buffer += len;
1258                 rem -= len;
1259         } while( rem > 0 );
1260
1261         LEAVE('i', Length);
1262         return Length;
1263 }
1264
1265 /**
1266  * \brief Open a connection to another host using TCP
1267  * \param Conn  Connection structure
1268  */
1269 void TCP_StartConnection(tTCPConnection *Conn)
1270 {
1271         tTCPHeader      hdr = {0};
1272
1273         Conn->State = TCP_ST_SYN_SENT;
1274
1275         hdr.SourcePort = htons(Conn->LocalPort);
1276         hdr.DestPort = htons(Conn->RemotePort);
1277         Conn->NextSequenceSend = rand();
1278         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1279         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1280         hdr.Flags = TCP_FLAG_SYN;
1281         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1282         hdr.Checksum = 0;       // TODO
1283
1284         TCP_SendPacket( Conn, &hdr, 0, NULL );
1285
1286         Conn->NextSequenceSend ++;
1287         Conn->State = TCP_ST_SYN_SENT;
1288
1289         return ;
1290 }
1291
1292 /**
1293  * \brief Control a client socket
1294  */
1295 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1296 {
1297         tTCPConnection  *conn = Node->ImplPtr;
1298
1299         ENTER("pNode iID pData", Node, ID, Data);
1300
1301         switch(ID)
1302         {
1303         case 4: // Get/Set local port
1304                 if(!Data)
1305                         LEAVE_RET('i', conn->LocalPort);
1306                 if(conn->State != TCP_ST_CLOSED)
1307                         LEAVE_RET('i', -1);
1308                 if(!CheckMem(Data, sizeof(Uint16)))
1309                         LEAVE_RET('i', -1);
1310
1311                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1312                         LEAVE_RET('i', -1);
1313
1314                 conn->LocalPort = *(Uint16*)Data;
1315                 LEAVE_RET('i', conn->LocalPort);
1316
1317         case 5: // Get/Set remote port
1318                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1319                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1320                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1321                 conn->RemotePort = *(Uint16*)Data;
1322                 LEAVE_RET('i', conn->RemotePort);
1323
1324         case 6: // Set Remote IP
1325                 if( conn->State != TCP_ST_CLOSED )
1326                         LEAVE_RET('i', -1);
1327                 if( conn->Interface->Type == 4 )
1328                 {
1329                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1330                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1331                 }
1332                 else if( conn->Interface->Type == 6 )
1333                 {
1334                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1335                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1336                 }
1337                 LEAVE_RET('i', 0);
1338
1339         case 7: // Connect
1340                 if(conn->LocalPort == 0xFFFF)
1341                         conn->LocalPort = TCP_GetUnusedPort();
1342                 if(conn->RemotePort == -1)
1343                         LEAVE_RET('i', 0);
1344
1345                 {
1346                         tTime   timeout = conn->Interface->TimeoutDelay;
1347
1348                         TCP_StartConnection(conn);
1349                         VFS_SelectNode(&conn->Node, VFS_SELECT_WRITE, &timeout, "TCP Connection");
1350                         if( conn->State == TCP_ST_SYN_SENT )
1351                                 LEAVE_RET('i', 0);
1352                 }
1353
1354                 LEAVE_RET('i', 1);
1355
1356         // Get recieve buffer length
1357         case 8:
1358                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1359         }
1360
1361         return 0;
1362 }
1363
1364 void TCP_Client_Close(tVFS_Node *Node)
1365 {
1366         tTCPConnection  *conn = Node->ImplPtr;
1367         tTCPHeader      packet;
1368
1369         ENTER("pNode", Node);
1370
1371         ASSERT(Node->ReferenceCount != 0);
1372
1373         if( Node->ReferenceCount > 1 ) {
1374                 Node->ReferenceCount --;
1375                 LOG("Dereference only");
1376                 LEAVE('-');
1377                 return ;
1378         }
1379
1380         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1381         {
1382                 packet.SourcePort = htons(conn->LocalPort);
1383                 packet.DestPort = htons(conn->RemotePort);
1384                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1385                 packet.WindowSize = TCP_WINDOW_SIZE;
1386
1387                 packet.AcknowlegementNumber = 0;
1388                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1389                 packet.Flags = TCP_FLAG_FIN;
1390
1391                 TCP_SendPacket( conn, &packet, 0, NULL );
1392         }
1393
1394         switch( conn->State )
1395         {
1396         case TCP_ST_CLOSED:
1397                 Log_Warning("TCP", "Closing connection that was never opened");
1398                 break;
1399         case TCP_ST_CLOSE_WAIT:
1400                 conn->State = TCP_ST_LAST_ACK;
1401                 break;
1402         case TCP_ST_OPEN:
1403                 conn->State = TCP_ST_FIN_WAIT1;
1404                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1405                 break;
1406         default:
1407                 Log_Warning("TCP", "Unhandled connection state %i in TCP_Client_Close",
1408                         conn->State);
1409                 break;
1410         }
1411
1412         Time_RemoveTimer(conn->DeferredACKTimer);
1413         Time_FreeTimer(conn->DeferredACKTimer);
1414         free(conn);
1415
1416         LEAVE('-');
1417 }
1418
1419 /**
1420  * \brief Checks if a value is between two others (after taking into account wrapping)
1421  */
1422 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1423 {
1424         if( MaxValue < 0xFFFFFFFF )
1425         {
1426                 Lower %= MaxValue + 1;
1427                 Value %= MaxValue + 1;
1428                 Higher %= MaxValue + 1;
1429         }
1430
1431         // Simple Case, no wrap ?
1432         //       Lower Value Higher
1433         // | ... + ... + ... + ... |
1434
1435         if( Lower < Higher ) {
1436                 return Lower < Value && Value < Higher;
1437         }
1438         // Higher has wrapped below lower
1439
1440         // Value > Lower ?
1441         //       Higher Lower Value
1442         // | ... +  ... + ... + ... |
1443         if( Value > Lower ) {
1444                 return 1;
1445         }
1446
1447         // Value < Higher ?
1448         //       Value Higher Lower
1449         // | ... + ... +  ... + ... |
1450         if( Value < Higher ) {
1451                 return 1;
1452         }
1453
1454         return 0;
1455 }