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