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 0x4000
  22
  23 // === PROTOTYPES ===
  24 void    TCP_Initialise(void);
  25 void    TCP_StartConnection(tTCPConnection *Conn);
  26 void    TCP_SendPacket(tTCPConnection *Conn, tTCPHeader *Header, size_t DataLen, const void *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 size_t  TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  43 size_t  TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t 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, tTCPHeader *Header, size_t Length, const void *Data )
  98 {
  99         tIPStackBuffer  *buffer;
 100         Uint16  checksum[3];
 101          int    packlen = sizeof(*Header) + Length;
 102
 103         buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
 104         if( Data && Length )
 105                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
 106         IPStack_Buffer_AppendSubBuffer(buffer, sizeof(*Header), 0, Header, NULL, NULL);
 107
 108         LOG("Sending %i+%i to %s:%i", sizeof(*Header), Length,
 109                 IPStack_PrintAddress(Conn->Interface->Type, &Conn->RemoteIP),
 110                 Conn->RemotePort
 111                 );
 112
 113         Header->Checksum = 0;
 114         checksum[1] = htons( ~IPv4_Checksum(Header, sizeof(tTCPHeader)) );
 115         checksum[2] = htons( ~IPv4_Checksum(Data, Length) );
 116
 117         // TODO: Fragment packet
 118
 119         switch( Conn->Interface->Type )
 120         {
 121         case 4:
 122                 // Get IPv4 pseudo-header checksum
 123                 {
 124                         Uint32  buf[3];
 125                         buf[0] = ((tIPv4*)Conn->Interface->Address)->L;
 126                         buf[1] = Conn->RemoteIP.v4.L;
 127                         buf[2] = (htons(packlen)<<16) | (6<<8) | 0;
 128                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 129                 }
 130                 // - Combine checksums
 131                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );
 132                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, buffer);
 133                 break;
 134
 135         case 6:
 136                 // Append IPv6 Pseudo Header
 137                 {
 138                         Uint32  buf[4+4+1+1];
 139                         memcpy(buf, Conn->Interface->Address, 16);
 140                         memcpy(&buf[4], &Conn->RemoteIP, 16);
 141                         buf[8] = htonl(packlen);
 142                         buf[9] = htonl(6);
 143                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 144                 }
 145                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );  // Combine the two
 146                 IPv6_SendPacket(Conn->Interface, Conn->RemoteIP.v6, IP4PROT_TCP, Length, Data);
 147                 break;
 148         }
 149 }
 150
 151 /**
 152  * \brief Handles a packet from the IP Layer
 153  * \param Interface     Interface the packet arrived from
 154  * \param Address       Pointer to the addres structure
 155  * \param Length        Size of packet in bytes
 156  * \param Buffer        Packet data
 157  */
 158 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 159 {
 160         tTCPHeader      *hdr = Buffer;
 161         tTCPListener    *srv;
 162         tTCPConnection  *conn;
 163
 164         Log_Log("TCP", "TCP_GetPacket: <Local>:%i from [%s]:%i, Flags = %s%s%s%s%s%s%s%s",
 165                 ntohs(hdr->DestPort),
 166                 IPStack_PrintAddress(Interface->Type, Address),
 167                 ntohs(hdr->SourcePort),
 168                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
 169                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
 170                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
 171                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
 172                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
 173                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
 174                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
 175                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
 176                 );
 177
 178         if( Length > (hdr->DataOffset >> 4)*4 )
 179         {
 180                 LOG("SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 181 #if HEXDUMP_INCOMING
 182                 Debug_HexDump(
 183                         "TCP_GetPacket: Packet Data = ",
 184                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 185                         Length - (hdr->DataOffset >> 4)*4
 186                         );
 187 #endif
 188         }
 189
 190         // Check Servers
 191         for( srv = gTCP_Listeners; srv; srv = srv->Next )
 192         {
 193                 // Check if the server is active
 194                 if(srv->Port == 0)      continue;
 195                 // Check the interface
 196                 if(srv->Interface && srv->Interface != Interface)       continue;
 197                 // Check the destination port
 198                 if(srv->Port != htons(hdr->DestPort))   continue;
 199
 200                 Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 201                 // Is this in an established connection?
 202                 for( conn = srv->Connections; conn; conn = conn->Next )
 203                 {
 204                         // Check that it is coming in on the same interface
 205                         if(conn->Interface != Interface)        continue;
 206
 207                         // Check Source Port
 208                         Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 209                                 conn->RemotePort, ntohs(hdr->SourcePort));
 210                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 211
 212                         // Check Source IP
 213                         Log_Debug("TCP", "TCP_GetPacket: conn->RemoteIP(%s)",
 214                                 IPStack_PrintAddress(conn->Interface->Type, &conn->RemoteIP));
 215                         Log_Debug("TCP", "                == Address(%s)",
 216                                 IPStack_PrintAddress(conn->Interface->Type, Address));
 217                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
 218                                 continue ;
 219
 220                         Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 221                         // We have a response!
 222                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 223
 224                         return;
 225                 }
 226
 227                 Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 228                 // Open a new connection (well, check that it's a SYN)
 229                 if(hdr->Flags != TCP_FLAG_SYN) {
 230                         Log_Log("TCP", "TCP_GetPacket: Packet is not a SYN");
 231                         return ;
 232                 }
 233
 234                 // TODO: Check for halfopen max
 235
 236                 conn = calloc(1, sizeof(tTCPConnection));
 237                 conn->State = TCP_ST_SYN_RCVD;
 238                 conn->LocalPort = srv->Port;
 239                 conn->RemotePort = ntohs(hdr->SourcePort);
 240                 conn->Interface = Interface;
 241
 242                 switch(Interface->Type)
 243                 {
 244                 case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 245                 case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 246                 }
 247
 248                 conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 249
 250                 conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 251                 conn->NextSequenceSend = rand();
 252
 253                 // Create node
 254                 conn->Node.NumACLs = 1;
 255                 conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 256                 conn->Node.ImplPtr = conn;
 257                 conn->Node.ImplInt = srv->NextID ++;
 258                 conn->Node.Type = &gTCP_ClientNodeType; // TODO: Special type for the server end?
 259
 260                 // Hmm... Theoretically, this lock will never have to wait,
 261                 // as the interface is locked to the watching thread, and this
 262                 // runs in the watching thread. But, it's a good idea to have
 263                 // it, just in case
 264                 // Oh, wait, there is a case where a wildcard can be used
 265                 // (srv->Interface == NULL) so having the lock is a good idea
 266                 SHORTLOCK(&srv->lConnections);
 267                 if( !srv->Connections )
 268                         srv->Connections = conn;
 269                 else
 270                         srv->ConnectionsTail->Next = conn;
 271                 srv->ConnectionsTail = conn;
 272                 if(!srv->NewConnections)
 273                         srv->NewConnections = conn;
 274                 VFS_MarkAvaliable( &srv->Node, 1 );
 275                 SHORTREL(&srv->lConnections);
 276
 277                 // Send the SYN ACK
 278                 hdr->Flags |= TCP_FLAG_ACK;
 279                 hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 280                 hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 281                 hdr->DestPort = hdr->SourcePort;
 282                 hdr->SourcePort = htons(srv->Port);
 283                 hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 284                 TCP_SendPacket( conn, hdr, 0, NULL );
 285                 conn->NextSequenceSend ++;
 286                 return ;
 287         }
 288
 289         // Check Open Connections
 290         {
 291                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 292                 {
 293                         // Check that it is coming in on the same interface
 294                         if(conn->Interface != Interface)        continue;
 295
 296                         // Check Source Port
 297                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 298
 299                         // Check Source IP
 300                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 301                                 continue;
 302                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 303                                 continue;
 304
 305                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 306                         return ;
 307                 }
 308         }
 309
 310         Log_Log("TCP", "TCP_GetPacket: No Match");
 311 }
 312
 313 /**
 314  * \brief Handles a packet sent to a specific connection
 315  * \param Connection    TCP Connection pointer
 316  * \param Header        TCP Packet pointer
 317  * \param Length        Length of the packet
 318  */
 319 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 320 {
 321          int    dataLen;
 322         Uint32  sequence_num;
 323
 324         // Silently drop once finished
 325         // TODO: Check if this needs to be here
 326         if( Connection->State == TCP_ST_FINISHED ) {
 327                 Log_Log("TCP", "Packet ignored - connection finnished");
 328                 return ;
 329         }
 330
 331         // Syncronise sequence values
 332         if(Header->Flags & TCP_FLAG_SYN) {
 333                 // TODO: What if the packet also has data?
 334                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
 335         }
 336
 337         // Ackowledge a sent packet
 338         if(Header->Flags & TCP_FLAG_ACK) {
 339                 // TODO: Process an ACKed Packet
 340                 LOG("Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 341         }
 342
 343         // Get length of data
 344         dataLen = Length - (Header->DataOffset>>4)*4;
 345         LOG("dataLen = %i", dataLen);
 346
 347         //
 348         // State Machine
 349         //
 350         switch( Connection->State )
 351         {
 352         // Pre-init connection?
 353         case TCP_ST_CLOSED:
 354                 Log_Log("TCP", "Packets to a closed connection?!");
 355                 break;
 356
 357         // --- Init States ---
 358         // SYN sent, expecting SYN-ACK Connection Opening
 359         case TCP_ST_SYN_SENT:
 360                 if( Header->Flags & TCP_FLAG_SYN )
 361                 {
 362                         Connection->NextSequenceRcv ++;
 363                         Header->DestPort = Header->SourcePort;
 364                         Header->SourcePort = htons(Connection->LocalPort);
 365                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 366                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 367                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 368                         Header->Flags = TCP_FLAG_ACK;
 369                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 370                         TCP_SendPacket( Connection, Header, 0, NULL );
 371
 372                         if( Header->Flags & TCP_FLAG_ACK )
 373                         {
 374                                 Log_Log("TCP", "ACKing SYN-ACK");
 375                                 Connection->State = TCP_ST_OPEN;
 376                         }
 377                         else
 378                         {
 379                                 Log_Log("TCP", "ACKing SYN");
 380                                 Connection->State = TCP_ST_SYN_RCVD;
 381                         }
 382                 }
 383                 break;
 384
 385         // SYN-ACK sent, expecting ACK
 386         case TCP_ST_SYN_RCVD:
 387                 if( Header->Flags & TCP_FLAG_ACK )
 388                 {
 389                         // TODO: Handle max half-open limit
 390                         Connection->State = TCP_ST_OPEN;
 391                         Log_Log("TCP", "Connection fully opened");
 392                 }
 393                 break;
 394
 395         // --- Established State ---
 396         case TCP_ST_OPEN:
 397                 // - Handle State changes
 398                 //
 399                 if( Header->Flags & TCP_FLAG_FIN ) {
 400                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
 401                         VFS_MarkError(&Connection->Node, 1);
 402                         Connection->State = TCP_ST_CLOSE_WAIT;
 403 //                      Header->Flags &= ~TCP_FLAG_FIN;
 404                         // CLOSE WAIT requires the client to close (or does it?)
 405                         #if 0
 406
 407                         #endif
 408                 }
 409
 410                 // Check for an empty packet
 411                 if(dataLen == 0) {
 412                         if( Header->Flags == TCP_FLAG_ACK )
 413                         {
 414                                 Log_Log("TCP", "ACK only packet");
 415                                 return ;
 416                         }
 417                         Connection->NextSequenceRcv ++; // TODO: Is this right? (empty packet counts as one byte)
 418                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
 419                         Header->DestPort = Header->SourcePort;
 420                         Header->SourcePort = htons(Connection->LocalPort);
 421                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 422                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 423                         Header->Flags |= TCP_FLAG_ACK;
 424                         TCP_SendPacket( Connection, Header, 0, NULL );
 425                         return ;
 426                 }
 427
 428                 // NOTES:
 429                 // Flags
 430                 //    PSH - Has Data?
 431                 // /NOTES
 432
 433                 sequence_num = ntohl(Header->SequenceNumber);
 434
 435                 LOG("TCP", "0x%08x <= 0x%08x < 0x%08x",
 436                         Connection->NextSequenceRcv,
 437                         ntohl(Header->SequenceNumber),
 438                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
 439                         );
 440
 441                 // Is this packet the next expected packet?
 442                 if( sequence_num == Connection->NextSequenceRcv )
 443                 {
 444                          int    rv;
 445                         // Ooh, Goodie! Add it to the recieved list
 446                         rv = TCP_INT_AppendRecieved(Connection,
 447                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 448                                 dataLen
 449                                 );
 450                         if(rv != 0) {
 451                                 break;
 452                         }
 453                         LOG("0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 454                         Connection->NextSequenceRcv += dataLen;
 455
 456                         // TODO: This should be moved out of the watcher thread,
 457                         // so that a single lost packet on one connection doesn't cause
 458                         // all connections on the interface to lag.
 459                         // - Meh, no real issue, as the cache shouldn't be that large
 460                         TCP_INT_UpdateRecievedFromFuture(Connection);
 461
 462                         // ACK Packet
 463                         // TODO: Implement delayed ACK sending
 464                         Header->DestPort = Header->SourcePort;
 465                         Header->SourcePort = htons(Connection->LocalPort);
 466                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 467                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 468                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 469                         Header->Flags &= TCP_FLAG_SYN;  // Eliminate all flags save for SYN
 470                         Header->Flags |= TCP_FLAG_ACK;  // Add ACK
 471                         LOG("TCP", "Sending ACK for 0x%08x", Connection->NextSequenceRcv);
 472                         TCP_SendPacket( Connection, Header, 0, NULL );
 473                         //Connection->NextSequenceSend ++;
 474                 }
 475                 // Check if the packet is in window
 476                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 477                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 478                 {
 479                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 480                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 481                         Uint32  index;
 482                          int    i;
 483
 484                         index = sequence_num % TCP_WINDOW_SIZE;
 485                         for( i = 0; i < dataLen; i ++ )
 486                         {
 487                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
 488                                 Connection->FuturePacketData[index] = dataptr[i];
 489                                 // Do a wrap increment
 490                                 index ++;
 491                                 if(index == TCP_WINDOW_SIZE)    index = 0;
 492                         }
 493                         #else
 494                         tTCPStoredPacket        *pkt, *tmp, *prev = NULL;
 495
 496                         // Allocate and fill cached packet
 497                         pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
 498                         pkt->Next = NULL;
 499                         pkt->Sequence = ntohl(Header->SequenceNumber);
 500                         pkt->Length = dataLen;
 501                         memcpy(pkt->Data, dataptr, dataLen);
 502
 503                         Log_Log("TCP", "We missed a packet, caching",
 504                                 pkt->Sequence, Connection->NextSequenceRcv);
 505
 506                         // No? Well, let's cache it and look at it later
 507                         SHORTLOCK( &Connection->lFuturePackets );
 508                         for(tmp = Connection->FuturePackets;
 509                                 tmp;
 510                                 prev = tmp, tmp = tmp->Next)
 511                         {
 512                                 if(tmp->Sequence >= pkt->Sequence)      break;
 513                         }
 514
 515                         // Add if before first, or sequences don't match
 516                         if( !tmp || tmp->Sequence != pkt->Sequence )
 517                         {
 518                                 if(prev)
 519                                         prev->Next = pkt;
 520                                 else
 521                                         Connection->FuturePackets = pkt;
 522                                 pkt->Next = tmp;
 523                         }
 524                         // Replace if larger
 525                         else if(pkt->Length > tmp->Length)
 526                         {
 527                                 if(prev)
 528                                         prev->Next = pkt;
 529                                 pkt->Next = tmp->Next;
 530                                 free(tmp);
 531                         }
 532                         else
 533                         {
 534                                 free(pkt);      // TODO: Find some way to remove this
 535                         }
 536                         SHORTREL( &Connection->lFuturePackets );
 537                         #endif
 538                 }
 539                 // Badly out of sequence packet
 540                 else
 541                 {
 542                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
 543                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
 544                         // TODO: Spec says we should send an empty ACK with the current state
 545                 }
 546                 break;
 547
 548         // --- Remote close states
 549         case TCP_ST_CLOSE_WAIT:
 550
 551                 // Ignore everything, CLOSE_WAIT is terminated by the client
 552                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
 553
 554                 break;
 555
 556         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
 557         case TCP_ST_LAST_ACK:
 558                 if( Header->Flags & TCP_FLAG_ACK )
 559                 {
 560                         Connection->State = TCP_ST_FINISHED;    // Connection completed
 561                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
 562                         // TODO: Destrory the TCB
 563                 }
 564                 break;
 565
 566         // --- Local close States
 567         case TCP_ST_FIN_WAIT1:
 568                 if( Header->Flags & TCP_FLAG_FIN )
 569                 {
 570                         Connection->State = TCP_ST_CLOSING;
 571                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
 572                         VFS_MarkError(&Connection->Node, 1);
 573
 574                         // ACK Packet
 575                         Header->DestPort = Header->SourcePort;
 576                         Header->SourcePort = htons(Connection->LocalPort);
 577                         Header->AcknowlegementNumber = Header->SequenceNumber;
 578                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 579                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 580                         Header->Flags = TCP_FLAG_ACK;
 581                         TCP_SendPacket( Connection, Header, 0, NULL );
 582                         break ;
 583                 }
 584
 585                 // TODO: Make sure that the packet is actually ACKing the FIN
 586                 if( Header->Flags & TCP_FLAG_ACK )
 587                 {
 588                         Connection->State = TCP_ST_FIN_WAIT2;
 589                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
 590                         VFS_MarkError(&Connection->Node, 1);
 591                         return ;
 592                 }
 593                 break;
 594
 595         case TCP_ST_FIN_WAIT2:
 596                 if( Header->Flags & TCP_FLAG_FIN )
 597                 {
 598                         Connection->State = TCP_ST_TIME_WAIT;
 599                         Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
 600                         // Send ACK
 601                         Header->DestPort = Header->SourcePort;
 602                         Header->SourcePort = htons(Connection->LocalPort);
 603                         Header->AcknowlegementNumber = Header->SequenceNumber;
 604                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 605                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 606                         Header->Flags = TCP_FLAG_ACK;
 607                         TCP_SendPacket( Connection, Header, 0, NULL );
 608                 }
 609                 break;
 610
 611         case TCP_ST_CLOSING:
 612                 // TODO: Make sure that the packet is actually ACKing the FIN
 613                 if( Header->Flags & TCP_FLAG_ACK )
 614                 {
 615                         Connection->State = TCP_ST_TIME_WAIT;
 616                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
 617                         VFS_MarkError(&Connection->Node, 1);
 618                         return ;
 619                 }
 620                 break;
 621
 622         // --- Closed (or near closed) states) ---
 623         case TCP_ST_TIME_WAIT:
 624                 Log_Log("TCP", "Packets on Time-Wait, ignored");
 625                 break;
 626
 627         case TCP_ST_FINISHED:
 628                 Log_Log("TCP", "Packets when CLOSED, ignoring");
 629                 break;
 630
 631         //default:
 632         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
 633         //      break;
 634         }
 635
 636 }
 637
 638 /**
 639  * \brief Appends a packet to the recieved list
 640  * \param Connection    Connection structure
 641  * \param Data  Packet contents
 642  * \param Length        Length of \a Data
 643  */
 644 int TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
 645 {
 646         Mutex_Acquire( &Connection->lRecievedPackets );
 647
 648         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
 649         {
 650                 VFS_MarkAvaliable(&Connection->Node, 1);
 651                 Log_Error("TCP", "Buffer filled, packet dropped (:%i) - %i + %i > %i",
 652                         Connection->LocalPort, Connection->RecievedBuffer->Length, Length,
 653                         Connection->RecievedBuffer->Space
 654                         );
 655                 Mutex_Release( &Connection->lRecievedPackets );
 656                 return 1;
 657         }
 658
 659         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
 660
 661         VFS_MarkAvaliable(&Connection->Node, 1);
 662
 663         Mutex_Release( &Connection->lRecievedPackets );
 664         return 0;
 665 }
 666
 667 /**
 668  * \brief Updates the connections recieved list from the future list
 669  * \param Connection    Connection structure
 670  *
 671  * Updates the recieved packets list with packets from the future (out
 672  * of order) packets list that are now able to be added in direct
 673  * sequence.
 674  */
 675 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 676 {
 677         #if CACHE_FUTURE_PACKETS_IN_BYTES
 678          int    i, length = 0;
 679         Uint32  index;
 680
 681         // Calculate length of contiguous bytes
 682         length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 683         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 684         for( i = 0; i < length; i ++ )
 685         {
 686                 if( Connection->FuturePacketValidBytes[i / 8] == 0xFF ) {
 687                         i += 7; index += 7;
 688                         continue;
 689                 }
 690                 else if( !(Connection->FuturePacketValidBytes[i / 8] & (1 << (i%8))) )
 691                         break;
 692
 693                 index ++;
 694                 if(index > TCP_WINDOW_SIZE)
 695                         index -= TCP_WINDOW_SIZE;
 696         }
 697         length = i;
 698
 699         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 700
 701         // Write data to to the ring buffer
 702         if( TCP_WINDOW_SIZE - index > length )
 703         {
 704                 // Simple case
 705                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 706         }
 707         else
 708         {
 709                  int    endLen = TCP_WINDOW_SIZE - index;
 710                 // 2-part case
 711                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 712                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 713         }
 714
 715         // Mark (now saved) bytes as invalid
 716         // - Align index
 717         while(index % 8 && length)
 718         {
 719                 Connection->FuturePacketData[index] = 0;
 720                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 721                 index ++;
 722                 if(index > TCP_WINDOW_SIZE)
 723                         index -= TCP_WINDOW_SIZE;
 724                 length --;
 725         }
 726         while( length > 7 )
 727         {
 728                 Connection->FuturePacketData[index] = 0;
 729                 Connection->FuturePacketValidBytes[index/8] = 0;
 730                 length -= 8;
 731                 index += 8;
 732                 if(index > TCP_WINDOW_SIZE)
 733                         index -= TCP_WINDOW_SIZE;
 734         }
 735         while(length)
 736         {
 737                 Connection->FuturePacketData[index] = 0;
 738                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 739                 index ++;
 740                 if(index > TCP_WINDOW_SIZE)
 741                         index -= TCP_WINDOW_SIZE;
 742                 length --;
 743         }
 744
 745         #else
 746         tTCPStoredPacket        *pkt;
 747         for(;;)
 748         {
 749                 SHORTLOCK( &Connection->lFuturePackets );
 750
 751                 // Clear out duplicates from cache
 752                 // - If a packet has just been recieved, and it is expected, then
 753                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 754                 //   packets in cache that are smaller than the next expected
 755                 //   are now defunct.
 756                 pkt = Connection->FuturePackets;
 757                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 758                 {
 759                         tTCPStoredPacket        *next = pkt->Next;
 760                         free(pkt);
 761                         pkt = next;
 762                 }
 763
 764                 // If there's no packets left in cache, stop looking
 765                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 766                         SHORTREL( &Connection->lFuturePackets );
 767                         return;
 768                 }
 769
 770                 // Delete packet from future list
 771                 Connection->FuturePackets = pkt->Next;
 772
 773                 // Release list
 774                 SHORTREL( &Connection->lFuturePackets );
 775
 776                 // Looks like we found one
 777                 TCP_INT_AppendRecieved(Connection, pkt);
 778                 Connection->NextSequenceRcv += pkt->Length;
 779                 free(pkt);
 780         }
 781         #endif
 782 }
 783
 784 /**
 785  * \fn Uint16 TCP_GetUnusedPort()
 786  * \brief Gets an unused port and allocates it
 787  */
 788 Uint16 TCP_GetUnusedPort()
 789 {
 790         Uint16  ret;
 791
 792         // Get Next outbound port
 793         ret = giTCP_NextOutPort++;
 794         while( gaTCP_PortBitmap[ret/32] & (1UL << (ret%32)) )
 795         {
 796                 ret ++;
 797                 giTCP_NextOutPort++;
 798                 if(giTCP_NextOutPort == 0x10000) {
 799                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 800                 }
 801         }
 802
 803         // Mark the new port as used
 804         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 805
 806         return ret;
 807 }
 808
 809 /**
 810  * \fn int TCP_AllocatePort(Uint16 Port)
 811  * \brief Marks a port as used
 812  */
 813 int TCP_AllocatePort(Uint16 Port)
 814 {
 815         // Check if the port has already been allocated
 816         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 817                 return 0;
 818
 819         // Allocate
 820         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 821
 822         return 1;
 823 }
 824
 825 /**
 826  * \fn int TCP_DeallocatePort(Uint16 Port)
 827  * \brief Marks a port as unused
 828  */
 829 int TCP_DeallocatePort(Uint16 Port)
 830 {
 831         // Check if the port has already been allocated
 832         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 833                 return 0;
 834
 835         // Allocate
 836         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 837
 838         return 1;
 839 }
 840
 841 // --- Server
 842 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 843 {
 844         tTCPListener    *srv;
 845
 846         srv = calloc( 1, sizeof(tTCPListener) );
 847
 848         if( srv == NULL ) {
 849                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 850                 return NULL;
 851         }
 852
 853         srv->Interface = Interface;
 854         srv->Port = 0;
 855         srv->NextID = 0;
 856         srv->Connections = NULL;
 857         srv->ConnectionsTail = NULL;
 858         srv->NewConnections = NULL;
 859         srv->Next = NULL;
 860         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 861         srv->Node.Size = -1;
 862         srv->Node.ImplPtr = srv;
 863         srv->Node.NumACLs = 1;
 864         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 865         srv->Node.Type = &gTCP_ServerNodeType;
 866
 867         SHORTLOCK(&glTCP_Listeners);
 868         srv->Next = gTCP_Listeners;
 869         gTCP_Listeners = srv;
 870         SHORTREL(&glTCP_Listeners);
 871
 872         return &srv->Node;
 873 }
 874
 875 /**
 876  * \brief Wait for a new connection and return the connection ID
 877  * \note Blocks until a new connection is made
 878  * \param Node  Server node
 879  * \param Pos   Position (ignored)
 880  */
 881 char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
 882 {
 883         tTCPListener    *srv = Node->ImplPtr;
 884         tTCPConnection  *conn;
 885         char    *ret;
 886
 887         ENTER("pNode iPos", Node, Pos);
 888
 889         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 890         for(;;)
 891         {
 892                 SHORTLOCK( &srv->lConnections );
 893                 if( srv->NewConnections != NULL )       break;
 894                 SHORTREL( &srv->lConnections );
 895                 Threads_Yield();        // TODO: Sleep until poked
 896         }
 897
 898
 899         // Increment the new list (the current connection is still on the
 900         // normal list)
 901         conn = srv->NewConnections;
 902         srv->NewConnections = conn->Next;
 903
 904         if( srv->NewConnections == NULL )
 905                 VFS_MarkAvaliable( Node, 0 );
 906
 907         SHORTREL( &srv->lConnections );
 908
 909         LOG("conn = %p", conn);
 910         LOG("srv->Connections = %p", srv->Connections);
 911         LOG("srv->NewConnections = %p", srv->NewConnections);
 912         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 913
 914         ret = malloc(9);
 915         itoa(ret, conn->Node.ImplInt, 16, 8, '0');
 916         Log_Log("TCP", "Thread %i got '%s'", Threads_GetTID(), ret);
 917         LEAVE('s', ret);
 918         return ret;
 919 }
 920
 921 /**
 922  * \brief Gets a client connection node
 923  * \param Node  Server node
 924  * \param Name  Hexadecimal ID of the node
 925  */
 926 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name)
 927 {
 928         tTCPConnection  *conn;
 929         tTCPListener    *srv = Node->ImplPtr;
 930         char    tmp[9];
 931          int    id = atoi(Name);
 932
 933         ENTER("pNode sName", Node, Name);
 934
 935         // Check for a non-empty name
 936         if( Name[0] )
 937         {
 938                 // Sanity Check
 939                 itoa(tmp, id, 16, 8, '0');
 940                 if(strcmp(tmp, Name) != 0) {
 941                         LOG("'%s' != '%s' (%08x)", Name, tmp, id);
 942                         LEAVE('n');
 943                         return NULL;
 944                 }
 945
 946                 Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
 947                 Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
 948                 Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 949
 950                 // Search
 951                 SHORTLOCK( &srv->lConnections );
 952                 for(conn = srv->Connections;
 953                         conn;
 954                         conn = conn->Next)
 955                 {
 956                         LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
 957                         if(conn->Node.ImplInt == id)    break;
 958                 }
 959                 SHORTREL( &srv->lConnections );
 960
 961                 // If not found, ret NULL
 962                 if(!conn) {
 963                         LOG("Connection %i not found", id);
 964                         LEAVE('n');
 965                         return NULL;
 966                 }
 967         }
 968         // Empty Name - Check for a new connection and if it's there, open it
 969         else
 970         {
 971                 SHORTLOCK( &srv->lConnections );
 972                 conn = srv->NewConnections;
 973                 if( conn != NULL )
 974                         srv->NewConnections = conn->Next;
 975                 VFS_MarkAvaliable( Node, srv->NewConnections != NULL );
 976                 SHORTREL( &srv->lConnections );
 977                 if( !conn ) {
 978                         LOG("No new connections");
 979                         LEAVE('n');
 980                         return NULL;
 981                 }
 982         }
 983
 984         // Return node
 985         LEAVE('p', &conn->Node);
 986         return &conn->Node;
 987 }
 988
 989 /**
 990  * \brief Handle IOCtl calls
 991  */
 992 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
 993 {
 994         tTCPListener    *srv = Node->ImplPtr;
 995
 996         switch(ID)
 997         {
 998         case 4: // Get/Set Port
 999                 if(!Data)       // Get Port
1000                         return srv->Port;
1001
1002                 if(srv->Port)   // Wait, you can't CHANGE the port
1003                         return -1;
1004
1005                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
1006                         return -1;
1007
1008                 // Permissions check
1009                 if(Threads_GetUID() != 0
1010                 && *(Uint16*)Data != 0
1011                 && *(Uint16*)Data < 1024)
1012                         return -1;
1013
1014                 // TODO: Check if a port is in use
1015
1016                 // Set Port
1017                 srv->Port = *(Uint16*)Data;
1018                 if(srv->Port == 0)      // Allocate a random port
1019                         srv->Port = TCP_GetUnusedPort();
1020                 else    // Else, mark this as used
1021                         TCP_AllocatePort(srv->Port);
1022
1023                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
1024
1025                 return srv->Port;
1026         }
1027         return 0;
1028 }
1029
1030 void TCP_Server_Close(tVFS_Node *Node)
1031 {
1032         free(Node->ImplPtr);
1033 }
1034
1035 // --- Client
1036 /**
1037  * \brief Create a client node
1038  */
1039 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1040 {
1041         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
1042
1043         conn->State = TCP_ST_CLOSED;
1044         conn->Interface = Interface;
1045         conn->LocalPort = -1;
1046         conn->RemotePort = -1;
1047
1048         conn->Node.ImplPtr = conn;
1049         conn->Node.NumACLs = 1;
1050         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
1051         conn->Node.Type = &gTCP_ClientNodeType;
1052
1053         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
1054         #if 0
1055         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
1056         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
1057         #endif
1058
1059         #if CACHE_FUTURE_PACKETS_IN_BYTES
1060         // Future recieved data (ahead of the expected sequence number)
1061         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
1062         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
1063         #endif
1064
1065         SHORTLOCK(&glTCP_OutbountCons);
1066         conn->Next = gTCP_OutbountCons;
1067         gTCP_OutbountCons = conn;
1068         SHORTREL(&glTCP_OutbountCons);
1069
1070         return &conn->Node;
1071 }
1072
1073 /**
1074  * \brief Wait for a packet and return it
1075  * \note If \a Length is smaller than the size of the packet, the rest
1076  *       of the packet's data will be discarded.
1077  */
1078 size_t TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
1079 {
1080         tTCPConnection  *conn = Node->ImplPtr;
1081         size_t  len;
1082
1083         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1084         LOG("conn = %p {State:%i}", conn, conn->State);
1085
1086         // Check if connection is estabilishing
1087         // - TODO: Sleep instead (maybe using VFS_SelectNode to wait for the
1088         //   data to be availiable
1089         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1090                 Threads_Yield();
1091
1092         // If the conneciton is not open, then clean out the recieved buffer
1093         if( conn->State != TCP_ST_OPEN )
1094         {
1095                 Mutex_Acquire( &conn->lRecievedPackets );
1096                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1097                 Mutex_Release( &conn->lRecievedPackets );
1098
1099                 if( len == 0 ) {
1100                         VFS_MarkAvaliable(Node, 0);
1101                         LEAVE('i', -1);
1102                         return -1;
1103                 }
1104
1105                 LEAVE('i', len);
1106                 return len;
1107         }
1108
1109         // Wait
1110         VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, NULL, "TCP_Client_Read");
1111
1112         // Lock list and read as much as possible (up to `Length`)
1113         Mutex_Acquire( &conn->lRecievedPackets );
1114         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1115
1116         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1117                 LOG("Marking as none avaliable (len = %i)", len);
1118                 VFS_MarkAvaliable(Node, 0);
1119         }
1120
1121         // Release the lock (we don't need it any more)
1122         Mutex_Release( &conn->lRecievedPackets );
1123
1124         LEAVE('i', len);
1125         return len;
1126 }
1127
1128 /**
1129  * \brief Send a data packet on a connection
1130  */
1131 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, const void *Data)
1132 {
1133         char    buf[sizeof(tTCPHeader)+Length];
1134         tTCPHeader      *packet = (void*)buf;
1135
1136         packet->SourcePort = htons(Connection->LocalPort);
1137         packet->DestPort = htons(Connection->RemotePort);
1138         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1139         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1140
1141         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1142         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1143         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1144
1145         memcpy(packet->Options, Data, Length);
1146
1147         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1148 #if HEXDUMP_OUTGOING
1149         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1150 #endif
1151
1152         TCP_SendPacket( Connection, packet, Length, Data );
1153
1154         Connection->NextSequenceSend += Length;
1155 }
1156
1157 /**
1158  * \brief Send some bytes on a connection
1159  */
1160 size_t TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer)
1161 {
1162         tTCPConnection  *conn = Node->ImplPtr;
1163         size_t  rem = Length;
1164
1165         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1166
1167 //      #if DEBUG
1168 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1169 //              Buffer, Length);
1170 //      #endif
1171
1172         // Check if connection is open
1173         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1174                 Threads_Yield();
1175
1176         if( conn->State != TCP_ST_OPEN ) {
1177                 VFS_MarkError(Node, 1);
1178                 LEAVE('i', -1);
1179                 return -1;
1180         }
1181
1182         do
1183         {
1184                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1185
1186                 #if 0
1187                 // Wait for space in the buffer
1188                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1189
1190                 // Save data to buffer (and update the length read by the ammount written)
1191                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1192                 #endif
1193
1194                 // Send packet
1195                 TCP_INT_SendDataPacket(conn, len, Buffer);
1196
1197                 Buffer += len;
1198                 rem -= len;
1199         } while( rem > 0 );
1200
1201         LEAVE('i', Length);
1202         return Length;
1203 }
1204
1205 /**
1206  * \brief Open a connection to another host using TCP
1207  * \param Conn  Connection structure
1208  */
1209 void TCP_StartConnection(tTCPConnection *Conn)
1210 {
1211         tTCPHeader      hdr = {0};
1212
1213         Conn->State = TCP_ST_SYN_SENT;
1214
1215         hdr.SourcePort = htons(Conn->LocalPort);
1216         hdr.DestPort = htons(Conn->RemotePort);
1217         Conn->NextSequenceSend = rand();
1218         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1219         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1220         hdr.Flags = TCP_FLAG_SYN;
1221         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1222         hdr.Checksum = 0;       // TODO
1223
1224         TCP_SendPacket( Conn, &hdr, 0, NULL );
1225
1226         Conn->NextSequenceSend ++;
1227         Conn->State = TCP_ST_SYN_SENT;
1228
1229         return ;
1230 }
1231
1232 /**
1233  * \brief Control a client socket
1234  */
1235 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1236 {
1237         tTCPConnection  *conn = Node->ImplPtr;
1238
1239         ENTER("pNode iID pData", Node, ID, Data);
1240
1241         switch(ID)
1242         {
1243         case 4: // Get/Set local port
1244                 if(!Data)
1245                         LEAVE_RET('i', conn->LocalPort);
1246                 if(conn->State != TCP_ST_CLOSED)
1247                         LEAVE_RET('i', -1);
1248                 if(!CheckMem(Data, sizeof(Uint16)))
1249                         LEAVE_RET('i', -1);
1250
1251                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1252                         LEAVE_RET('i', -1);
1253
1254                 conn->LocalPort = *(Uint16*)Data;
1255                 LEAVE_RET('i', conn->LocalPort);
1256
1257         case 5: // Get/Set remote port
1258                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1259                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1260                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1261                 conn->RemotePort = *(Uint16*)Data;
1262                 LEAVE_RET('i', conn->RemotePort);
1263
1264         case 6: // Set Remote IP
1265                 if( conn->State != TCP_ST_CLOSED )
1266                         LEAVE_RET('i', -1);
1267                 if( conn->Interface->Type == 4 )
1268                 {
1269                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1270                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1271                 }
1272                 else if( conn->Interface->Type == 6 )
1273                 {
1274                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1275                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1276                 }
1277                 LEAVE_RET('i', 0);
1278
1279         case 7: // Connect
1280                 if(conn->LocalPort == 0xFFFF)
1281                         conn->LocalPort = TCP_GetUnusedPort();
1282                 if(conn->RemotePort == -1)
1283                         LEAVE_RET('i', 0);
1284
1285                 {
1286                         tTime   timeout_end = now() + conn->Interface->TimeoutDelay;
1287
1288                         TCP_StartConnection(conn);
1289                         // TODO: Wait for connection to open
1290                         while( conn->State == TCP_ST_SYN_SENT && timeout_end > now() ) {
1291                                 Threads_Yield();
1292                         }
1293                         if( conn->State == TCP_ST_SYN_SENT )
1294                                 LEAVE_RET('i', 0);
1295                 }
1296
1297                 LEAVE_RET('i', 1);
1298
1299         // Get recieve buffer length
1300         case 8:
1301                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1302         }
1303
1304         return 0;
1305 }
1306
1307 void TCP_Client_Close(tVFS_Node *Node)
1308 {
1309         tTCPConnection  *conn = Node->ImplPtr;
1310         tTCPHeader      packet;
1311
1312         ENTER("pNode", Node);
1313
1314         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1315         {
1316                 packet.SourcePort = htons(conn->LocalPort);
1317                 packet.DestPort = htons(conn->RemotePort);
1318                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1319                 packet.WindowSize = TCP_WINDOW_SIZE;
1320
1321                 packet.AcknowlegementNumber = 0;
1322                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1323                 packet.Flags = TCP_FLAG_FIN;
1324
1325                 TCP_SendPacket( conn, &packet, 0, NULL );
1326         }
1327
1328         switch( conn->State )
1329         {
1330         case TCP_ST_CLOSE_WAIT:
1331                 conn->State = TCP_ST_LAST_ACK;
1332                 break;
1333         case TCP_ST_OPEN:
1334                 conn->State = TCP_ST_FIN_WAIT1;
1335                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1336                 break;
1337         default:
1338                 Log_Warning("TCP", "Unhandled connection state in TCP_Client_Close");
1339                 break;
1340         }
1341
1342         free(conn);
1343
1344         LEAVE('-');
1345 }
1346
1347 /**
1348  * \brief Checks if a value is between two others (after taking into account wrapping)
1349  */
1350 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1351 {
1352         if( MaxValue < 0xFFFFFFFF )
1353         {
1354                 Lower %= MaxValue + 1;
1355                 Value %= MaxValue + 1;
1356                 Higher %= MaxValue + 1;
1357         }
1358
1359         // Simple Case, no wrap ?
1360         //       Lower Value Higher
1361         // | ... + ... + ... + ... |
1362
1363         if( Lower < Higher ) {
1364                 return Lower < Value && Value < Higher;
1365         }
1366         // Higher has wrapped below lower
1367
1368         // Value > Lower ?
1369         //       Higher Lower Value
1370         // | ... +  ... + ... + ... |
1371         if( Value > Lower ) {
1372                 return 1;
1373         }
1374
1375         // Value < Higher ?
1376         //       Value Higher Lower
1377         // | ... + ... +  ... + ... |
1378         if( Value < Higher ) {
1379                 return 1;
1380         }
1381
1382         return 0;
1383 }