Modules/IPStack/tcp.c

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