KernelLand/Modules/IPStack/tcp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - TCP Handling
   4  */
   5 #define DEBUG   0
   6 #include "ipstack.h"
   7 #include "ipv4.h"
   8 #include "ipv6.h"
   9 #include "tcp.h"
  10
  11 #define USE_SELECT      1
  12 #define HEXDUMP_INCOMING        0
  13 #define HEXDUMP_OUTGOING        0
  14 #define CACHE_FUTURE_PACKETS_IN_BYTES   1       // Use a ring buffer to cache out of order packets
  15
  16 #define TCP_MIN_DYNPORT 0xC000
  17 #define TCP_MAX_HALFOPEN        1024    // Should be enough
  18
  19 #define TCP_MAX_PACKET_SIZE     1024
  20 #define TCP_WINDOW_SIZE 0x2000
  21 #define TCP_RECIEVE_BUFFER_SIZE 0x8000
  22 #define TCP_DACK_THRESHOLD      4096
  23 #define TCP_DACK_TIMEOUT        500
  24
  25 // === PROTOTYPES ===
  26 void    TCP_Initialise(void);
  27 void    TCP_StartConnection(tTCPConnection *Conn);
  28 void    TCP_SendPacket(tTCPConnection *Conn, tTCPHeader *Header, size_t DataLen, const void *Data);
  29 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  30 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  31 int     TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length);
  32 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  33 void    TCP_INT_SendACK(tTCPConnection *Connection);
  34 Uint16  TCP_GetUnusedPort();
  35  int    TCP_AllocatePort(Uint16 Port);
  36  int    TCP_DeallocatePort(Uint16 Port);
  37 // --- Server
  38 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  39  int    TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Name[FILENAME_MAX]);
  40 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, const char *Name);
  41  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  42 void    TCP_Server_Close(tVFS_Node *Node);
  43 // --- Client
  44 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  45 size_t  TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  46 size_t  TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer);
  47  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  48 void    TCP_Client_Close(tVFS_Node *Node);
  49 // --- Helpers
  50  int    WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
  51
  52 // === TEMPLATES ===
  53 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  54 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  55 tVFS_NodeType   gTCP_ServerNodeType = {
  56         .TypeName = "TCP Server",
  57         .ReadDir = TCP_Server_ReadDir,
  58         .FindDir = TCP_Server_FindDir,
  59         .IOCtl   = TCP_Server_IOCtl,
  60         .Close   = TCP_Server_Close
  61         };
  62 tVFS_NodeType   gTCP_ClientNodeType = {
  63         .TypeName = "TCP Client/Connection",
  64         .Read  = TCP_Client_Read,
  65         .Write = TCP_Client_Write,
  66         .IOCtl = TCP_Client_IOCtl,
  67         .Close = TCP_Client_Close
  68         };
  69
  70 // === GLOBALS ===
  71  int    giTCP_NumHalfopen = 0;
  72 tShortSpinlock  glTCP_Listeners;
  73 tTCPListener    *gTCP_Listeners;
  74 tShortSpinlock  glTCP_OutbountCons;
  75 tTCPConnection  *gTCP_OutbountCons;
  76 Uint32  gaTCP_PortBitmap[0x800];
  77  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  78
  79 // === CODE ===
  80 /**
  81  * \brief Initialise the TCP Layer
  82  *
  83  * Registers the client and server files and the GetPacket callback
  84  */
  85 void TCP_Initialise(void)
  86 {
  87         giTCP_NextOutPort += rand()%32;
  88         IPStack_AddFile(&gTCP_ServerFile);
  89         IPStack_AddFile(&gTCP_ClientFile);
  90         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  91         IPv6_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  92 }
  93
  94 /**
  95  * \brief Sends a packet from the specified connection, calculating the checksums
  96  * \param Conn  Connection
  97  * \param Length        Length of data
  98  * \param Data  Packet data (cast as a TCP Header)
  99  */
 100 void TCP_SendPacket( tTCPConnection *Conn, tTCPHeader *Header, size_t Length, const void *Data )
 101 {
 102         tIPStackBuffer  *buffer;
 103         Uint16  checksum[3];
 104          int    packlen = sizeof(*Header) + Length;
 105
 106         buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
 107         if( Data && Length )
 108                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
 109         IPStack_Buffer_AppendSubBuffer(buffer, sizeof(*Header), 0, Header, NULL, NULL);
 110
 111         LOG("Sending %i+%i to %s:%i", sizeof(*Header), Length,
 112                 IPStack_PrintAddress(Conn->Interface->Type, &Conn->RemoteIP),
 113                 Conn->RemotePort
 114                 );
 115
 116         Header->Checksum = 0;
 117         checksum[1] = htons( ~IPv4_Checksum(Header, sizeof(tTCPHeader)) );
 118         checksum[2] = htons( ~IPv4_Checksum(Data, Length) );
 119
 120         // TODO: Fragment packet
 121
 122         switch( Conn->Interface->Type )
 123         {
 124         case 4:
 125                 // Get IPv4 pseudo-header checksum
 126                 {
 127                         Uint32  buf[3];
 128                         buf[0] = ((tIPv4*)Conn->Interface->Address)->L;
 129                         buf[1] = Conn->RemoteIP.v4.L;
 130                         buf[2] = (htons(packlen)<<16) | (6<<8) | 0;
 131                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 132                 }
 133                 // - Combine checksums
 134                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );
 135                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, buffer);
 136                 break;
 137
 138         case 6:
 139                 // Append IPv6 Pseudo Header
 140                 {
 141                         Uint32  buf[4+4+1+1];
 142                         memcpy(buf, Conn->Interface->Address, 16);
 143                         memcpy(&buf[4], &Conn->RemoteIP, 16);
 144                         buf[8] = htonl(packlen);
 145                         buf[9] = htonl(6);
 146                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 147                 }
 148                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );  // Combine the two
 149                 IPv6_SendPacket(Conn->Interface, Conn->RemoteIP.v6, IP4PROT_TCP, Length, Data);
 150                 break;
 151         }
 152 }
 153
 154 /**
 155  * \brief Handles a packet from the IP Layer
 156  * \param Interface     Interface the packet arrived from
 157  * \param Address       Pointer to the addres structure
 158  * \param Length        Size of packet in bytes
 159  * \param Buffer        Packet data
 160  */
 161 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 162 {
 163         tTCPHeader      *hdr = Buffer;
 164         tTCPListener    *srv;
 165         tTCPConnection  *conn;
 166
 167         Log_Log("TCP", "TCP_GetPacket: <Local>:%i from [%s]:%i, Flags = %s%s%s%s%s%s%s%s",
 168                 ntohs(hdr->DestPort),
 169                 IPStack_PrintAddress(Interface->Type, Address),
 170                 ntohs(hdr->SourcePort),
 171                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
 172                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
 173                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
 174                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
 175                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
 176                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
 177                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
 178                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
 179                 );
 180
 181         if( Length > (hdr->DataOffset >> 4)*4 )
 182         {
 183                 LOG("SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 184 #if HEXDUMP_INCOMING
 185                 Debug_HexDump(
 186                         "TCP_GetPacket: Packet Data = ",
 187                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 188                         Length - (hdr->DataOffset >> 4)*4
 189                         );
 190 #endif
 191         }
 192
 193         // Check Servers
 194         for( srv = gTCP_Listeners; srv; srv = srv->Next )
 195         {
 196                 // Check if the server is active
 197                 if(srv->Port == 0)      continue;
 198                 // Check the interface
 199                 if(srv->Interface && srv->Interface != Interface)       continue;
 200                 // Check the destination port
 201                 if(srv->Port != htons(hdr->DestPort))   continue;
 202
 203                 Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 204                 // Is this in an established connection?
 205                 for( conn = srv->Connections; conn; conn = conn->Next )
 206                 {
 207                         // Check that it is coming in on the same interface
 208                         if(conn->Interface != Interface)        continue;
 209
 210                         // Check Source Port
 211                         Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 212                                 conn->RemotePort, ntohs(hdr->SourcePort));
 213                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 214
 215                         // Check Source IP
 216                         Log_Debug("TCP", "TCP_GetPacket: conn->RemoteIP(%s)",
 217                                 IPStack_PrintAddress(conn->Interface->Type, &conn->RemoteIP));
 218                         Log_Debug("TCP", "                == Address(%s)",
 219                                 IPStack_PrintAddress(conn->Interface->Type, Address));
 220                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
 221                                 continue ;
 222
 223                         Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 224                         // We have a response!
 225                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 226
 227                         return;
 228                 }
 229
 230                 Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 231                 // Open a new connection (well, check that it's a SYN)
 232                 if(hdr->Flags != TCP_FLAG_SYN) {
 233                         Log_Log("TCP", "TCP_GetPacket: Packet is not a SYN");
 234                         return ;
 235                 }
 236
 237                 // TODO: Check for halfopen max
 238
 239                 conn = calloc(1, sizeof(tTCPConnection));
 240                 conn->State = TCP_ST_SYN_RCVD;
 241                 conn->LocalPort = srv->Port;
 242                 conn->RemotePort = ntohs(hdr->SourcePort);
 243                 conn->Interface = Interface;
 244
 245                 switch(Interface->Type)
 246                 {
 247                 case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 248                 case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 249                 }
 250
 251                 conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 252
 253                 conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 254                 conn->NextSequenceSend = rand();
 255
 256                 // Create node
 257                 conn->Node.NumACLs = 1;
 258                 conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 259                 conn->Node.ImplPtr = conn;
 260                 conn->Node.ImplInt = srv->NextID ++;
 261                 conn->Node.Type = &gTCP_ClientNodeType; // TODO: Special type for the server end?
 262
 263                 // Hmm... Theoretically, this lock will never have to wait,
 264                 // as the interface is locked to the watching thread, and this
 265                 // runs in the watching thread. But, it's a good idea to have
 266                 // it, just in case
 267                 // Oh, wait, there is a case where a wildcard can be used
 268                 // (srv->Interface == NULL) so having the lock is a good idea
 269                 SHORTLOCK(&srv->lConnections);
 270                 if( !srv->Connections )
 271                         srv->Connections = conn;
 272                 else
 273                         srv->ConnectionsTail->Next = conn;
 274                 srv->ConnectionsTail = conn;
 275                 if(!srv->NewConnections)
 276                         srv->NewConnections = conn;
 277                 VFS_MarkAvaliable( &srv->Node, 1 );
 278                 SHORTREL(&srv->lConnections);
 279
 280                 // Send the SYN ACK
 281                 hdr->Flags |= TCP_FLAG_ACK;
 282                 hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 283                 hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 284                 hdr->DestPort = hdr->SourcePort;
 285                 hdr->SourcePort = htons(srv->Port);
 286                 hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 287                 TCP_SendPacket( conn, hdr, 0, NULL );
 288                 conn->NextSequenceSend ++;
 289                 return ;
 290         }
 291
 292         // Check Open Connections
 293         {
 294                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 295                 {
 296                         // Check that it is coming in on the same interface
 297                         if(conn->Interface != Interface)        continue;
 298
 299                         // Check Source Port
 300                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 301
 302                         // Check Source IP
 303                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 304                                 continue;
 305                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 306                                 continue;
 307
 308                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 309                         return ;
 310                 }
 311         }
 312
 313         Log_Log("TCP", "TCP_GetPacket: No Match");
 314 }
 315
 316 /**
 317  * \brief Handles a packet sent to a specific connection
 318  * \param Connection    TCP Connection pointer
 319  * \param Header        TCP Packet pointer
 320  * \param Length        Length of the packet
 321  */
 322 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 323 {
 324          int    dataLen;
 325         Uint32  sequence_num;
 326
 327         // Silently drop once finished
 328         // TODO: Check if this needs to be here
 329         if( Connection->State == TCP_ST_FINISHED ) {
 330                 Log_Log("TCP", "Packet ignored - connection finnished");
 331                 return ;
 332         }
 333
 334         // Syncronise sequence values
 335         if(Header->Flags & TCP_FLAG_SYN) {
 336                 // TODO: What if the packet also has data?
 337                 if( Connection->LastACKSequence != Connection->NextSequenceRcv )
 338                         TCP_INT_SendACK(Connection);
 339                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
 340                 Connection->LastACKSequence = Connection->NextSequenceRcv;
 341         }
 342
 343         // Ackowledge a sent packet
 344         if(Header->Flags & TCP_FLAG_ACK) {
 345                 // TODO: Process an ACKed Packet
 346                 LOG("Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 347         }
 348
 349         // Get length of data
 350         dataLen = Length - (Header->DataOffset>>4)*4;
 351         LOG("dataLen = %i", dataLen);
 352 //      Log_Debug("TCP", "State %i, dataLen = %x", Connection->State, dataLen);
 353
 354         //
 355         // State Machine
 356         //
 357         switch( Connection->State )
 358         {
 359         // Pre-init connection?
 360         case TCP_ST_CLOSED:
 361                 Log_Log("TCP", "Packets to a closed connection?!");
 362                 break;
 363
 364         // --- Init States ---
 365         // SYN sent, expecting SYN-ACK Connection Opening
 366         case TCP_ST_SYN_SENT:
 367                 if( Header->Flags & TCP_FLAG_SYN )
 368                 {
 369                         Connection->NextSequenceRcv ++;
 370                         Header->DestPort = Header->SourcePort;
 371                         Header->SourcePort = htons(Connection->LocalPort);
 372                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 373                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 374                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 375                         Header->Flags = TCP_FLAG_ACK;
 376                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 377                         TCP_SendPacket( Connection, Header, 0, NULL );
 378
 379                         if( Header->Flags & TCP_FLAG_ACK )
 380                         {
 381                                 Log_Log("TCP", "ACKing SYN-ACK");
 382                                 Connection->State = TCP_ST_OPEN;
 383                         }
 384                         else
 385                         {
 386                                 Log_Log("TCP", "ACKing SYN");
 387                                 Connection->State = TCP_ST_SYN_RCVD;
 388                         }
 389                 }
 390                 break;
 391
 392         // SYN-ACK sent, expecting ACK
 393         case TCP_ST_SYN_RCVD:
 394                 if( Header->Flags & TCP_FLAG_ACK )
 395                 {
 396                         // TODO: Handle max half-open limit
 397                         Connection->State = TCP_ST_OPEN;
 398                         Log_Log("TCP", "Connection fully opened");
 399                 }
 400                 break;
 401
 402         // --- Established State ---
 403         case TCP_ST_OPEN:
 404                 // - Handle State changes
 405                 //
 406                 if( Header->Flags & TCP_FLAG_FIN ) {
 407                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
 408                         VFS_MarkError(&Connection->Node, 1);
 409                         Connection->State = TCP_ST_CLOSE_WAIT;
 410 //                      Header->Flags &= ~TCP_FLAG_FIN;
 411                         // CLOSE WAIT requires the client to close (or does it?)
 412                         #if 0
 413
 414                         #endif
 415                 }
 416
 417                 // Check for an empty packet
 418                 if(dataLen == 0) {
 419                         if( Header->Flags == TCP_FLAG_ACK )
 420                         {
 421                                 Log_Log("TCP", "ACK only packet");
 422                                 return ;
 423                         }
 424                         Connection->NextSequenceRcv ++; // TODO: Is this right? (empty packet counts as one byte)
 425                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
 426                         Header->DestPort = Header->SourcePort;
 427                         Header->SourcePort = htons(Connection->LocalPort);
 428                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 429                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 430                         Header->Flags |= TCP_FLAG_ACK;
 431                         TCP_SendPacket( Connection, Header, 0, NULL );
 432                         return ;
 433                 }
 434
 435                 // NOTES:
 436                 // Flags
 437                 //    PSH - Has Data?
 438                 // /NOTES
 439
 440                 sequence_num = ntohl(Header->SequenceNumber);
 441
 442                 LOG("TCP", "0x%08x <= 0x%08x < 0x%08x",
 443                         Connection->NextSequenceRcv,
 444                         ntohl(Header->SequenceNumber),
 445                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
 446                         );
 447
 448                 // Is this packet the next expected packet?
 449                 if( sequence_num == Connection->NextSequenceRcv )
 450                 {
 451                          int    rv;
 452                         // Ooh, Goodie! Add it to the recieved list
 453                         rv = TCP_INT_AppendRecieved(Connection,
 454                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 455                                 dataLen
 456                                 );
 457                         if(rv != 0) {
 458                                 Log_Notice("TCP", "TCP_INT_AppendRecieved rv %i", rv);
 459                                 break;
 460                         }
 461                         LOG("0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 462                         Connection->NextSequenceRcv += dataLen;
 463
 464                         // TODO: This should be moved out of the watcher thread,
 465                         // so that a single lost packet on one connection doesn't cause
 466                         // all connections on the interface to lag.
 467                         // - Meh, no real issue, as the cache shouldn't be that large
 468                         TCP_INT_UpdateRecievedFromFuture(Connection);
 469
 470                         #if 1
 471                         // - Only send an ACK if we've had a burst
 472                         if( Connection->NextSequenceRcv > (Uint32)(TCP_DACK_THRESHOLD + Connection->LastACKSequence) )
 473                         {
 474                                 TCP_INT_SendACK(Connection);
 475                                 // - Extend TCP deferred ACK timer
 476                                 Time_RemoveTimer(Connection->DeferredACKTimer);
 477                         }
 478                         // - Schedule the deferred ACK timer (if already scheduled, this is a NOP)
 479                         Time_ScheduleTimer(Connection->DeferredACKTimer, TCP_DACK_TIMEOUT);
 480                         #else
 481                         TCP_INT_SendACK(Connection);
 482                         #endif
 483                 }
 484                 // Check if the packet is in window
 485                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 486                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 487                 {
 488                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 489                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 490                         Uint32  index;
 491                          int    i;
 492
 493                         index = sequence_num % TCP_WINDOW_SIZE;
 494                         for( i = 0; i < dataLen; i ++ )
 495                         {
 496                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
 497                                 Connection->FuturePacketData[index] = dataptr[i];
 498                                 // Do a wrap increment
 499                                 index ++;
 500                                 if(index == TCP_WINDOW_SIZE)    index = 0;
 501                         }
 502                         #else
 503                         tTCPStoredPacket        *pkt, *tmp, *prev = NULL;
 504
 505                         // Allocate and fill cached packet
 506                         pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
 507                         pkt->Next = NULL;
 508                         pkt->Sequence = ntohl(Header->SequenceNumber);
 509                         pkt->Length = dataLen;
 510                         memcpy(pkt->Data, dataptr, dataLen);
 511
 512                         Log_Log("TCP", "We missed a packet, caching",
 513                                 pkt->Sequence, Connection->NextSequenceRcv);
 514
 515                         // No? Well, let's cache it and look at it later
 516                         SHORTLOCK( &Connection->lFuturePackets );
 517                         for(tmp = Connection->FuturePackets;
 518                                 tmp;
 519                                 prev = tmp, tmp = tmp->Next)
 520                         {
 521                                 if(tmp->Sequence >= pkt->Sequence)      break;
 522                         }
 523
 524                         // Add if before first, or sequences don't match
 525                         if( !tmp || tmp->Sequence != pkt->Sequence )
 526                         {
 527                                 if(prev)
 528                                         prev->Next = pkt;
 529                                 else
 530                                         Connection->FuturePackets = pkt;
 531                                 pkt->Next = tmp;
 532                         }
 533                         // Replace if larger
 534                         else if(pkt->Length > tmp->Length)
 535                         {
 536                                 if(prev)
 537                                         prev->Next = pkt;
 538                                 pkt->Next = tmp->Next;
 539                                 free(tmp);
 540                         }
 541                         else
 542                         {
 543                                 free(pkt);      // TODO: Find some way to remove this
 544                         }
 545                         SHORTREL( &Connection->lFuturePackets );
 546                         #endif
 547                 }
 548                 // Badly out of sequence packet
 549                 else
 550                 {
 551                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
 552                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
 553                         // Spec says we should send an empty ACK with the current state
 554                         TCP_INT_SendACK(Connection);
 555                 }
 556                 break;
 557
 558         // --- Remote close states
 559         case TCP_ST_CLOSE_WAIT:
 560
 561                 // Ignore everything, CLOSE_WAIT is terminated by the client
 562                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
 563
 564                 break;
 565
 566         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
 567         case TCP_ST_LAST_ACK:
 568                 if( Header->Flags & TCP_FLAG_ACK )
 569                 {
 570                         Connection->State = TCP_ST_FINISHED;    // Connection completed
 571                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
 572                         // TODO: Destrory the TCB
 573                 }
 574                 break;
 575
 576         // --- Local close States
 577         case TCP_ST_FIN_WAIT1:
 578                 if( Header->Flags & TCP_FLAG_FIN )
 579                 {
 580                         Connection->State = TCP_ST_CLOSING;
 581                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
 582                         VFS_MarkError(&Connection->Node, 1);
 583
 584                         // ACK Packet
 585                         Header->DestPort = Header->SourcePort;
 586                         Header->SourcePort = htons(Connection->LocalPort);
 587                         Header->AcknowlegementNumber = Header->SequenceNumber;
 588                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 589                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 590                         Header->Flags = TCP_FLAG_ACK;
 591                         TCP_SendPacket( Connection, Header, 0, NULL );
 592                         break ;
 593                 }
 594
 595                 // TODO: Make sure that the packet is actually ACKing the FIN
 596                 if( Header->Flags & TCP_FLAG_ACK )
 597                 {
 598                         Connection->State = TCP_ST_FIN_WAIT2;
 599                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
 600                         VFS_MarkError(&Connection->Node, 1);
 601                         return ;
 602                 }
 603                 break;
 604
 605         case TCP_ST_FIN_WAIT2:
 606                 if( Header->Flags & TCP_FLAG_FIN )
 607                 {
 608                         Connection->State = TCP_ST_TIME_WAIT;
 609                         Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
 610                         // Send ACK
 611                         Header->DestPort = Header->SourcePort;
 612                         Header->SourcePort = htons(Connection->LocalPort);
 613                         Header->AcknowlegementNumber = Header->SequenceNumber;
 614                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 615                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 616                         Header->Flags = TCP_FLAG_ACK;
 617                         TCP_SendPacket( Connection, Header, 0, NULL );
 618                 }
 619                 break;
 620
 621         case TCP_ST_CLOSING:
 622                 // TODO: Make sure that the packet is actually ACKing the FIN
 623                 if( Header->Flags & TCP_FLAG_ACK )
 624                 {
 625                         Connection->State = TCP_ST_TIME_WAIT;
 626                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
 627                         VFS_MarkError(&Connection->Node, 1);
 628                         return ;
 629                 }
 630                 break;
 631
 632         // --- Closed (or near closed) states) ---
 633         case TCP_ST_TIME_WAIT:
 634                 Log_Log("TCP", "Packets on Time-Wait, ignored");
 635                 break;
 636
 637         case TCP_ST_FINISHED:
 638                 Log_Log("TCP", "Packets when CLOSED, ignoring");
 639                 break;
 640
 641         //default:
 642         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
 643         //      break;
 644         }
 645
 646 }
 647
 648 /**
 649  * \brief Appends a packet to the recieved list
 650  * \param Connection    Connection structure
 651  * \param Data  Packet contents
 652  * \param Length        Length of \a Data
 653  */
 654 int TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
 655 {
 656         Mutex_Acquire( &Connection->lRecievedPackets );
 657
 658         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
 659         {
 660                 VFS_MarkAvaliable(&Connection->Node, 1);
 661                 Log_Error("TCP", "Buffer filled, packet dropped (:%i) - %i + %i > %i",
 662                         Connection->LocalPort, Connection->RecievedBuffer->Length, Length,
 663                         Connection->RecievedBuffer->Space
 664                         );
 665                 Mutex_Release( &Connection->lRecievedPackets );
 666                 return 1;
 667         }
 668
 669         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
 670
 671         VFS_MarkAvaliable(&Connection->Node, 1);
 672
 673         Mutex_Release( &Connection->lRecievedPackets );
 674         return 0;
 675 }
 676
 677 /**
 678  * \brief Updates the connections recieved list from the future list
 679  * \param Connection    Connection structure
 680  *
 681  * Updates the recieved packets list with packets from the future (out
 682  * of order) packets list that are now able to be added in direct
 683  * sequence.
 684  */
 685 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 686 {
 687         #if CACHE_FUTURE_PACKETS_IN_BYTES
 688          int    i, length = 0;
 689         Uint32  index;
 690
 691         // Calculate length of contiguous bytes
 692         length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 693         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 694         for( i = 0; i < length; i ++ )
 695         {
 696                 if( Connection->FuturePacketValidBytes[i / 8] == 0xFF ) {
 697                         i += 7; index += 7;
 698                         continue;
 699                 }
 700                 else if( !(Connection->FuturePacketValidBytes[i / 8] & (1 << (i%8))) )
 701                         break;
 702
 703                 index ++;
 704                 if(index > TCP_WINDOW_SIZE)
 705                         index -= TCP_WINDOW_SIZE;
 706         }
 707         length = i;
 708
 709         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 710
 711         // Write data to to the ring buffer
 712         if( TCP_WINDOW_SIZE - index > length )
 713         {
 714                 // Simple case
 715                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 716         }
 717         else
 718         {
 719                  int    endLen = TCP_WINDOW_SIZE - index;
 720                 // 2-part case
 721                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 722                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 723         }
 724
 725         // Mark (now saved) bytes as invalid
 726         // - Align index
 727         while(index % 8 && length)
 728         {
 729                 Connection->FuturePacketData[index] = 0;
 730                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 731                 index ++;
 732                 if(index > TCP_WINDOW_SIZE)
 733                         index -= TCP_WINDOW_SIZE;
 734                 length --;
 735         }
 736         while( length > 7 )
 737         {
 738                 Connection->FuturePacketData[index] = 0;
 739                 Connection->FuturePacketValidBytes[index/8] = 0;
 740                 length -= 8;
 741                 index += 8;
 742                 if(index > TCP_WINDOW_SIZE)
 743                         index -= TCP_WINDOW_SIZE;
 744         }
 745         while(length)
 746         {
 747                 Connection->FuturePacketData[index] = 0;
 748                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 749                 index ++;
 750                 if(index > TCP_WINDOW_SIZE)
 751                         index -= TCP_WINDOW_SIZE;
 752                 length --;
 753         }
 754
 755         #else
 756         tTCPStoredPacket        *pkt;
 757         for(;;)
 758         {
 759                 SHORTLOCK( &Connection->lFuturePackets );
 760
 761                 // Clear out duplicates from cache
 762                 // - If a packet has just been recieved, and it is expected, then
 763                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 764                 //   packets in cache that are smaller than the next expected
 765                 //   are now defunct.
 766                 pkt = Connection->FuturePackets;
 767                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 768                 {
 769                         tTCPStoredPacket        *next = pkt->Next;
 770                         free(pkt);
 771                         pkt = next;
 772                 }
 773
 774                 // If there's no packets left in cache, stop looking
 775                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 776                         SHORTREL( &Connection->lFuturePackets );
 777                         return;
 778                 }
 779
 780                 // Delete packet from future list
 781                 Connection->FuturePackets = pkt->Next;
 782
 783                 // Release list
 784                 SHORTREL( &Connection->lFuturePackets );
 785
 786                 // Looks like we found one
 787                 TCP_INT_AppendRecieved(Connection, pkt);
 788                 Connection->NextSequenceRcv += pkt->Length;
 789                 free(pkt);
 790         }
 791         #endif
 792 }
 793
 794 void TCP_INT_SendACK(tTCPConnection *Connection)
 795 {
 796         tTCPHeader      hdr;
 797         // ACK Packet
 798         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
 799         hdr.DestPort = htons(Connection->RemotePort);
 800         hdr.SourcePort = htons(Connection->LocalPort);
 801         hdr.AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 802         hdr.SequenceNumber = htonl(Connection->NextSequenceSend);
 803         hdr.WindowSize = htons(TCP_WINDOW_SIZE);
 804         hdr.Flags = TCP_FLAG_ACK;       // TODO: Determine if SYN is wanted too
 805         hdr.Checksum = 0;       // TODO: Checksum
 806         hdr.UrgentPointer = 0;
 807         Log_Debug("TCP", "Sending ACK for 0x%08x", Connection->NextSequenceRcv);
 808         TCP_SendPacket( Connection, &hdr, 0, NULL );
 809         //Connection->NextSequenceSend ++;
 810         Connection->LastACKSequence = Connection->NextSequenceRcv;
 811 }
 812
 813 /**
 814  * \fn Uint16 TCP_GetUnusedPort()
 815  * \brief Gets an unused port and allocates it
 816  */
 817 Uint16 TCP_GetUnusedPort()
 818 {
 819         Uint16  ret;
 820
 821         // Get Next outbound port
 822         ret = giTCP_NextOutPort++;
 823         while( gaTCP_PortBitmap[ret/32] & (1UL << (ret%32)) )
 824         {
 825                 ret ++;
 826                 giTCP_NextOutPort++;
 827                 if(giTCP_NextOutPort == 0x10000) {
 828                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 829                 }
 830         }
 831
 832         // Mark the new port as used
 833         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 834
 835         return ret;
 836 }
 837
 838 /**
 839  * \fn int TCP_AllocatePort(Uint16 Port)
 840  * \brief Marks a port as used
 841  */
 842 int TCP_AllocatePort(Uint16 Port)
 843 {
 844         // Check if the port has already been allocated
 845         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 846                 return 0;
 847
 848         // Allocate
 849         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 850
 851         return 1;
 852 }
 853
 854 /**
 855  * \fn int TCP_DeallocatePort(Uint16 Port)
 856  * \brief Marks a port as unused
 857  */
 858 int TCP_DeallocatePort(Uint16 Port)
 859 {
 860         // Check if the port has already been allocated
 861         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 862                 return 0;
 863
 864         // Allocate
 865         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 866
 867         return 1;
 868 }
 869
 870 // --- Server
 871 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 872 {
 873         tTCPListener    *srv;
 874
 875         srv = calloc( 1, sizeof(tTCPListener) );
 876
 877         if( srv == NULL ) {
 878                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 879                 return NULL;
 880         }
 881
 882         srv->Interface = Interface;
 883         srv->Port = 0;
 884         srv->NextID = 0;
 885         srv->Connections = NULL;
 886         srv->ConnectionsTail = NULL;
 887         srv->NewConnections = NULL;
 888         srv->Next = NULL;
 889         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 890         srv->Node.Size = -1;
 891         srv->Node.ImplPtr = srv;
 892         srv->Node.NumACLs = 1;
 893         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 894         srv->Node.Type = &gTCP_ServerNodeType;
 895
 896         SHORTLOCK(&glTCP_Listeners);
 897         srv->Next = gTCP_Listeners;
 898         gTCP_Listeners = srv;
 899         SHORTREL(&glTCP_Listeners);
 900
 901         return &srv->Node;
 902 }
 903
 904 /**
 905  * \brief Wait for a new connection and return the connection ID
 906  * \note Blocks until a new connection is made
 907  * \param Node  Server node
 908  * \param Pos   Position (ignored)
 909  */
 910 int TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Dest[FILENAME_MAX])
 911 {
 912         tTCPListener    *srv = Node->ImplPtr;
 913         tTCPConnection  *conn;
 914
 915         ENTER("pNode iPos", Node, Pos);
 916
 917         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 918         for(;;)
 919         {
 920                 SHORTLOCK( &srv->lConnections );
 921                 if( srv->NewConnections != NULL )       break;
 922                 SHORTREL( &srv->lConnections );
 923                 Threads_Yield();        // TODO: Sleep until poked
 924         }
 925
 926
 927         // Increment the new list (the current connection is still on the
 928         // normal list)
 929         conn = srv->NewConnections;
 930         srv->NewConnections = conn->Next;
 931
 932         if( srv->NewConnections == NULL )
 933                 VFS_MarkAvaliable( Node, 0 );
 934
 935         SHORTREL( &srv->lConnections );
 936
 937         LOG("conn = %p", conn);
 938         LOG("srv->Connections = %p", srv->Connections);
 939         LOG("srv->NewConnections = %p", srv->NewConnections);
 940         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 941
 942         itoa(Dest, conn->Node.ImplInt, 16, 8, '0');
 943         Log_Log("TCP", "Thread %i got connection '%s'", Threads_GetTID(), Dest);
 944         LEAVE('i', 0);
 945         return 0;
 946 }
 947
 948 /**
 949  * \brief Gets a client connection node
 950  * \param Node  Server node
 951  * \param Name  Hexadecimal ID of the node
 952  */
 953 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name)
 954 {
 955         tTCPConnection  *conn;
 956         tTCPListener    *srv = Node->ImplPtr;
 957         char    tmp[9];
 958          int    id = atoi(Name);
 959
 960         ENTER("pNode sName", Node, Name);
 961
 962         // Check for a non-empty name
 963         if( Name[0] )
 964         {
 965                 // Sanity Check
 966                 itoa(tmp, id, 16, 8, '0');
 967                 if(strcmp(tmp, Name) != 0) {
 968                         LOG("'%s' != '%s' (%08x)", Name, tmp, id);
 969                         LEAVE('n');
 970                         return NULL;
 971                 }
 972
 973                 Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
 974                 Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
 975                 Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 976
 977                 // Search
 978                 SHORTLOCK( &srv->lConnections );
 979                 for(conn = srv->Connections;
 980                         conn;
 981                         conn = conn->Next)
 982                 {
 983                         LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
 984                         if(conn->Node.ImplInt == id)    break;
 985                 }
 986                 SHORTREL( &srv->lConnections );
 987
 988                 // If not found, ret NULL
 989                 if(!conn) {
 990                         LOG("Connection %i not found", id);
 991                         LEAVE('n');
 992                         return NULL;
 993                 }
 994         }
 995         // Empty Name - Check for a new connection and if it's there, open it
 996         else
 997         {
 998                 SHORTLOCK( &srv->lConnections );
 999                 conn = srv->NewConnections;
1000                 if( conn != NULL )
1001                         srv->NewConnections = conn->Next;
1002                 VFS_MarkAvaliable( Node, srv->NewConnections != NULL );
1003                 SHORTREL( &srv->lConnections );
1004                 if( !conn ) {
1005                         LOG("No new connections");
1006                         LEAVE('n');
1007                         return NULL;
1008                 }
1009         }
1010
1011         // Return node
1012         LEAVE('p', &conn->Node);
1013         return &conn->Node;
1014 }
1015
1016 /**
1017  * \brief Handle IOCtl calls
1018  */
1019 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
1020 {
1021         tTCPListener    *srv = Node->ImplPtr;
1022
1023         switch(ID)
1024         {
1025         case 4: // Get/Set Port
1026                 if(!Data)       // Get Port
1027                         return srv->Port;
1028
1029                 if(srv->Port)   // Wait, you can't CHANGE the port
1030                         return -1;
1031
1032                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
1033                         return -1;
1034
1035                 // Permissions check
1036                 if(Threads_GetUID() != 0
1037                 && *(Uint16*)Data != 0
1038                 && *(Uint16*)Data < 1024)
1039                         return -1;
1040
1041                 // TODO: Check if a port is in use
1042
1043                 // Set Port
1044                 srv->Port = *(Uint16*)Data;
1045                 if(srv->Port == 0)      // Allocate a random port
1046                         srv->Port = TCP_GetUnusedPort();
1047                 else    // Else, mark this as used
1048                         TCP_AllocatePort(srv->Port);
1049
1050                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
1051
1052                 return srv->Port;
1053         }
1054         return 0;
1055 }
1056
1057 void TCP_Server_Close(tVFS_Node *Node)
1058 {
1059         free(Node->ImplPtr);
1060 }
1061
1062 // --- Client
1063 /**
1064  * \brief Create a client node
1065  */
1066 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1067 {
1068         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
1069
1070         conn->State = TCP_ST_CLOSED;
1071         conn->Interface = Interface;
1072         conn->LocalPort = -1;
1073         conn->RemotePort = -1;
1074
1075         conn->Node.ImplPtr = conn;
1076         conn->Node.NumACLs = 1;
1077         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
1078         conn->Node.Type = &gTCP_ClientNodeType;
1079
1080         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
1081         #if 0
1082         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
1083         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
1084         #endif
1085
1086         #if CACHE_FUTURE_PACKETS_IN_BYTES
1087         // Future recieved data (ahead of the expected sequence number)
1088         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
1089         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
1090         #endif
1091
1092         conn->DeferredACKTimer = Time_AllocateTimer( (void(*)(void*)) TCP_INT_SendACK, conn);
1093
1094         SHORTLOCK(&glTCP_OutbountCons);
1095         conn->Next = gTCP_OutbountCons;
1096         gTCP_OutbountCons = conn;
1097         SHORTREL(&glTCP_OutbountCons);
1098
1099         return &conn->Node;
1100 }
1101
1102 /**
1103  * \brief Wait for a packet and return it
1104  * \note If \a Length is smaller than the size of the packet, the rest
1105  *       of the packet's data will be discarded.
1106  */
1107 size_t TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
1108 {
1109         tTCPConnection  *conn = Node->ImplPtr;
1110         size_t  len;
1111
1112         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1113         LOG("conn = %p {State:%i}", conn, conn->State);
1114
1115         // Check if connection is estabilishing
1116         // - TODO: Sleep instead (maybe using VFS_SelectNode to wait for the
1117         //   data to be availiable
1118         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1119                 Threads_Yield();
1120
1121         // If the conneciton is not open, then clean out the recieved buffer
1122         if( conn->State != TCP_ST_OPEN )
1123         {
1124                 Mutex_Acquire( &conn->lRecievedPackets );
1125                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1126                 Mutex_Release( &conn->lRecievedPackets );
1127
1128                 if( len == 0 ) {
1129                         VFS_MarkAvaliable(Node, 0);
1130                         LEAVE('i', -1);
1131                         return -1;
1132                 }
1133
1134                 LEAVE('i', len);
1135                 return len;
1136         }
1137
1138         // Wait
1139         VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, NULL, "TCP_Client_Read");
1140
1141         // Lock list and read as much as possible (up to `Length`)
1142         Mutex_Acquire( &conn->lRecievedPackets );
1143         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1144
1145         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1146                 LOG("Marking as none avaliable (len = %i)", len);
1147                 VFS_MarkAvaliable(Node, 0);
1148         }
1149
1150         // Release the lock (we don't need it any more)
1151         Mutex_Release( &conn->lRecievedPackets );
1152
1153         LEAVE('i', len);
1154         return len;
1155 }
1156
1157 /**
1158  * \brief Send a data packet on a connection
1159  */
1160 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, const void *Data)
1161 {
1162         char    buf[sizeof(tTCPHeader)+Length];
1163         tTCPHeader      *packet = (void*)buf;
1164
1165         packet->SourcePort = htons(Connection->LocalPort);
1166         packet->DestPort = htons(Connection->RemotePort);
1167         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1168         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1169
1170         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1171         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1172         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1173
1174         memcpy(packet->Options, Data, Length);
1175
1176         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1177 #if HEXDUMP_OUTGOING
1178         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1179 #endif
1180
1181         TCP_SendPacket( Connection, packet, Length, Data );
1182
1183         Connection->NextSequenceSend += Length;
1184 }
1185
1186 /**
1187  * \brief Send some bytes on a connection
1188  */
1189 size_t TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer)
1190 {
1191         tTCPConnection  *conn = Node->ImplPtr;
1192         size_t  rem = Length;
1193
1194         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1195
1196 //      #if DEBUG
1197 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1198 //              Buffer, Length);
1199 //      #endif
1200
1201         // Check if connection is open
1202         while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
1203                 Threads_Yield();
1204
1205         if( conn->State != TCP_ST_OPEN ) {
1206                 VFS_MarkError(Node, 1);
1207                 LEAVE('i', -1);
1208                 return -1;
1209         }
1210
1211         do
1212         {
1213                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1214
1215                 #if 0
1216                 // Wait for space in the buffer
1217                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1218
1219                 // Save data to buffer (and update the length read by the ammount written)
1220                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1221                 #endif
1222
1223                 // Send packet
1224                 TCP_INT_SendDataPacket(conn, len, Buffer);
1225
1226                 Buffer += len;
1227                 rem -= len;
1228         } while( rem > 0 );
1229
1230         LEAVE('i', Length);
1231         return Length;
1232 }
1233
1234 /**
1235  * \brief Open a connection to another host using TCP
1236  * \param Conn  Connection structure
1237  */
1238 void TCP_StartConnection(tTCPConnection *Conn)
1239 {
1240         tTCPHeader      hdr = {0};
1241
1242         Conn->State = TCP_ST_SYN_SENT;
1243
1244         hdr.SourcePort = htons(Conn->LocalPort);
1245         hdr.DestPort = htons(Conn->RemotePort);
1246         Conn->NextSequenceSend = rand();
1247         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1248         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1249         hdr.Flags = TCP_FLAG_SYN;
1250         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1251         hdr.Checksum = 0;       // TODO
1252
1253         TCP_SendPacket( Conn, &hdr, 0, NULL );
1254
1255         Conn->NextSequenceSend ++;
1256         Conn->State = TCP_ST_SYN_SENT;
1257
1258         return ;
1259 }
1260
1261 /**
1262  * \brief Control a client socket
1263  */
1264 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1265 {
1266         tTCPConnection  *conn = Node->ImplPtr;
1267
1268         ENTER("pNode iID pData", Node, ID, Data);
1269
1270         switch(ID)
1271         {
1272         case 4: // Get/Set local port
1273                 if(!Data)
1274                         LEAVE_RET('i', conn->LocalPort);
1275                 if(conn->State != TCP_ST_CLOSED)
1276                         LEAVE_RET('i', -1);
1277                 if(!CheckMem(Data, sizeof(Uint16)))
1278                         LEAVE_RET('i', -1);
1279
1280                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1281                         LEAVE_RET('i', -1);
1282
1283                 conn->LocalPort = *(Uint16*)Data;
1284                 LEAVE_RET('i', conn->LocalPort);
1285
1286         case 5: // Get/Set remote port
1287                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1288                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1289                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1290                 conn->RemotePort = *(Uint16*)Data;
1291                 LEAVE_RET('i', conn->RemotePort);
1292
1293         case 6: // Set Remote IP
1294                 if( conn->State != TCP_ST_CLOSED )
1295                         LEAVE_RET('i', -1);
1296                 if( conn->Interface->Type == 4 )
1297                 {
1298                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1299                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1300                 }
1301                 else if( conn->Interface->Type == 6 )
1302                 {
1303                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1304                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1305                 }
1306                 LEAVE_RET('i', 0);
1307
1308         case 7: // Connect
1309                 if(conn->LocalPort == 0xFFFF)
1310                         conn->LocalPort = TCP_GetUnusedPort();
1311                 if(conn->RemotePort == -1)
1312                         LEAVE_RET('i', 0);
1313
1314                 {
1315                         tTime   timeout_end = now() + conn->Interface->TimeoutDelay;
1316
1317                         TCP_StartConnection(conn);
1318                         // TODO: Wait for connection to open
1319                         while( conn->State == TCP_ST_SYN_SENT && timeout_end > now() ) {
1320                                 Threads_Yield();
1321                         }
1322                         if( conn->State == TCP_ST_SYN_SENT )
1323                                 LEAVE_RET('i', 0);
1324                 }
1325
1326                 LEAVE_RET('i', 1);
1327
1328         // Get recieve buffer length
1329         case 8:
1330                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1331         }
1332
1333         return 0;
1334 }
1335
1336 void TCP_Client_Close(tVFS_Node *Node)
1337 {
1338         tTCPConnection  *conn = Node->ImplPtr;
1339         tTCPHeader      packet;
1340
1341         ENTER("pNode", Node);
1342
1343         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1344         {
1345                 packet.SourcePort = htons(conn->LocalPort);
1346                 packet.DestPort = htons(conn->RemotePort);
1347                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1348                 packet.WindowSize = TCP_WINDOW_SIZE;
1349
1350                 packet.AcknowlegementNumber = 0;
1351                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1352                 packet.Flags = TCP_FLAG_FIN;
1353
1354                 TCP_SendPacket( conn, &packet, 0, NULL );
1355         }
1356
1357         switch( conn->State )
1358         {
1359         case TCP_ST_CLOSE_WAIT:
1360                 conn->State = TCP_ST_LAST_ACK;
1361                 break;
1362         case TCP_ST_OPEN:
1363                 conn->State = TCP_ST_FIN_WAIT1;
1364                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1365                 break;
1366         default:
1367                 Log_Warning("TCP", "Unhandled connection state in TCP_Client_Close");
1368                 break;
1369         }
1370
1371         Time_RemoveTimer(conn->DeferredACKTimer);
1372         Time_FreeTimer(conn->DeferredACKTimer);
1373         free(conn);
1374
1375         LEAVE('-');
1376 }
1377
1378 /**
1379  * \brief Checks if a value is between two others (after taking into account wrapping)
1380  */
1381 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1382 {
1383         if( MaxValue < 0xFFFFFFFF )
1384         {
1385                 Lower %= MaxValue + 1;
1386                 Value %= MaxValue + 1;
1387                 Higher %= MaxValue + 1;
1388         }
1389
1390         // Simple Case, no wrap ?
1391         //       Lower Value Higher
1392         // | ... + ... + ... + ... |
1393
1394         if( Lower < Higher ) {
1395                 return Lower < Value && Value < Higher;
1396         }
1397         // Higher has wrapped below lower
1398
1399         // Value > Lower ?
1400         //       Higher Lower Value
1401         // | ... +  ... + ... + ... |
1402         if( Value > Lower ) {
1403                 return 1;
1404         }
1405
1406         // Value < Higher ?
1407         //       Value Higher Lower
1408         // | ... + ... +  ... + ... |
1409         if( Value < Higher ) {
1410                 return 1;
1411         }
1412
1413         return 0;
1414 }