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
  15 #define TCP_MIN_DYNPORT 0xC000
  16 #define TCP_MAX_HALFOPEN        1024    // Should be enough
  17
  18 #define TCP_MAX_PACKET_SIZE     1024
  19 #define TCP_WINDOW_SIZE 0x2000
  20 #define TCP_RECIEVE_BUFFER_SIZE 0x8000
  21 #define TCP_DACK_THRESHOLD      4096
  22 #define TCP_DACK_TIMEOUT        500
  23
  24 #define TCP_DEBUG       0       // Set to non-0 to enable TCP packet logging
  25
  26 // === PROTOTYPES ===
  27 void    TCP_Initialise(void);
  28 void    TCP_StartConnection(tTCPConnection *Conn);
  29 void    TCP_SendPacket(tTCPConnection *Conn, tTCPHeader *Header, size_t DataLen, const void *Data);
  30 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  31 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  32 int     TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length);
  33 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  34 void    TCP_int_SendDelayedACK(void *ConnPtr);
  35 void    TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason);
  36 Uint16  TCP_GetUnusedPort();
  37  int    TCP_AllocatePort(Uint16 Port);
  38  int    TCP_DeallocatePort(Uint16 Port);
  39 tTCPConnection  *TCP_int_CreateConnection(tInterface *Interface, enum eTCPConnectionState State);
  40 // --- Server
  41 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  42  int    TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Name[FILENAME_MAX]);
  43 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags);
  44  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  45 void    TCP_Server_Close(tVFS_Node *Node);
  46 // --- Client
  47 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  48 size_t  TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  49 size_t  TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags);
  50  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  51 void    TCP_Client_Close(tVFS_Node *Node);
  52 // --- Helpers
  53  int    WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
  54
  55 // === TEMPLATES ===
  56 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  57 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  58 tVFS_NodeType   gTCP_ServerNodeType = {
  59         .TypeName = "TCP Server",
  60         .ReadDir = TCP_Server_ReadDir,
  61         .FindDir = TCP_Server_FindDir,
  62         .IOCtl   = TCP_Server_IOCtl,
  63         .Close   = TCP_Server_Close
  64         };
  65 tVFS_NodeType   gTCP_ClientNodeType = {
  66         .TypeName = "TCP Client/Connection",
  67         .Read  = TCP_Client_Read,
  68         .Write = TCP_Client_Write,
  69         .IOCtl = TCP_Client_IOCtl,
  70         .Close = TCP_Client_Close
  71         };
  72
  73 // === GLOBALS ===
  74  int    giTCP_NumHalfopen = 0;
  75 tShortSpinlock  glTCP_Listeners;
  76 tTCPListener    *gTCP_Listeners;
  77 tShortSpinlock  glTCP_OutbountCons;
  78 tTCPConnection  *gTCP_OutbountCons;
  79 Uint32  gaTCP_PortBitmap[0x800];
  80  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  81
  82 // === CODE ===
  83 /**
  84  * \brief Initialise the TCP Layer
  85  *
  86  * Registers the client and server files and the GetPacket callback
  87  */
  88 void TCP_Initialise(void)
  89 {
  90         giTCP_NextOutPort += rand()%32;
  91         IPStack_AddFile(&gTCP_ServerFile);
  92         IPStack_AddFile(&gTCP_ClientFile);
  93         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  94         IPv6_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  95 }
  96
  97 /**
  98  * \brief Sends a packet from the specified connection, calculating the checksums
  99  * \param Conn  Connection
 100  * \param Length        Length of data
 101  * \param Data  Packet data (cast as a TCP Header)
 102  */
 103 void TCP_SendPacket( tTCPConnection *Conn, tTCPHeader *Header, size_t Length, const void *Data )
 104 {
 105         tIPStackBuffer  *buffer;
 106         Uint16  checksum[3];
 107          int    packlen = sizeof(*Header) + Length;
 108
 109         buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
 110         if( Data && Length )
 111                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
 112         IPStack_Buffer_AppendSubBuffer(buffer, sizeof(*Header), 0, Header, NULL, NULL);
 113
 114         LOG("Sending %i+%i to %s:%i", sizeof(*Header), Length,
 115                 IPStack_PrintAddress(Conn->Interface->Type, &Conn->RemoteIP),
 116                 Conn->RemotePort
 117                 );
 118
 119         Header->Checksum = 0;
 120         checksum[1] = htons( ~IPv4_Checksum(Header, sizeof(tTCPHeader)) );
 121         checksum[2] = htons( ~IPv4_Checksum(Data, Length) );
 122
 123         // TODO: Fragment packet
 124
 125         switch( Conn->Interface->Type )
 126         {
 127         case 4:
 128                 // Get IPv4 pseudo-header checksum
 129                 {
 130                         Uint32  buf[3];
 131                         buf[0] = ((tIPv4*)Conn->Interface->Address)->L;
 132                         buf[1] = Conn->RemoteIP.v4.L;
 133                         buf[2] = (htons(packlen)<<16) | (6<<8) | 0;
 134                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 135                 }
 136                 // - Combine checksums
 137                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );
 138                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, buffer);
 139                 break;
 140
 141         case 6:
 142                 // Append IPv6 Pseudo Header
 143                 {
 144                         Uint32  buf[4+4+1+1];
 145                         memcpy(buf, Conn->Interface->Address, 16);
 146                         memcpy(&buf[4], &Conn->RemoteIP, 16);
 147                         buf[8] = htonl(packlen);
 148                         buf[9] = htonl(6);
 149                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 150                 }
 151                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );  // Combine the two
 152                 IPv6_SendPacket(Conn->Interface, Conn->RemoteIP.v6, IP4PROT_TCP, Length, Data);
 153                 break;
 154         }
 155 }
 156
 157 /**
 158  * \brief Handles a packet from the IP Layer
 159  * \param Interface     Interface the packet arrived from
 160  * \param Address       Pointer to the addres structure
 161  * \param Length        Size of packet in bytes
 162  * \param Buffer        Packet data
 163  */
 164 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 165 {
 166         tTCPHeader      *hdr = Buffer;
 167         tTCPListener    *srv;
 168         tTCPConnection  *conn;
 169
 170         #if TCP_DEBUG
 171         Log_Log("TCP", "TCP_GetPacket: <Local>:%i from [%s]:%i, Flags = %s%s%s%s%s%s%s%s",
 172                 ntohs(hdr->DestPort),
 173                 IPStack_PrintAddress(Interface->Type, Address),
 174                 ntohs(hdr->SourcePort),
 175                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
 176                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
 177                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
 178                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
 179                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
 180                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
 181                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
 182                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
 183                 );
 184         #endif
 185
 186         if( Length > (hdr->DataOffset >> 4)*4 )
 187         {
 188                 LOG("SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 189 #if HEXDUMP_INCOMING
 190                 Debug_HexDump(
 191                         "TCP_GetPacket: Packet Data = ",
 192                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 193                         Length - (hdr->DataOffset >> 4)*4
 194                         );
 195 #endif
 196         }
 197
 198         // Check Servers
 199         for( srv = gTCP_Listeners; srv; srv = srv->Next )
 200         {
 201                 // Check if the server is active
 202                 if(srv->Port == 0)      continue;
 203                 // Check the interface
 204                 if(srv->Interface && srv->Interface != Interface)       continue;
 205                 // Check the destination port
 206                 if(srv->Port != htons(hdr->DestPort))   continue;
 207
 208                 Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 209                 // Is this in an established connection?
 210                 for( conn = srv->Connections; conn; conn = conn->Next )
 211                 {
 212                         // Check that it is coming in on the same interface
 213                         if(conn->Interface != Interface)        continue;
 214
 215                         // Check Source Port
 216                         Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 217                                 conn->RemotePort, ntohs(hdr->SourcePort));
 218                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 219
 220                         // Check Source IP
 221                         Log_Debug("TCP", "TCP_GetPacket: conn->RemoteIP(%s)",
 222                                 IPStack_PrintAddress(conn->Interface->Type, &conn->RemoteIP));
 223                         Log_Debug("TCP", "                == Address(%s)",
 224                                 IPStack_PrintAddress(conn->Interface->Type, Address));
 225                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
 226                                 continue ;
 227
 228                         Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 229                         // We have a response!
 230                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 231
 232                         return;
 233                 }
 234
 235                 Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 236                 // Open a new connection (well, check that it's a SYN)
 237                 if(hdr->Flags != TCP_FLAG_SYN) {
 238                         Log_Log("TCP", "TCP_GetPacket: Packet is not a SYN");
 239                         return ;
 240                 }
 241
 242                 // TODO: Check for halfopen max
 243
 244                 conn = TCP_int_CreateConnection(Interface, TCP_ST_SYN_RCVD);
 245                 conn->LocalPort = srv->Port;
 246                 conn->RemotePort = ntohs(hdr->SourcePort);
 247
 248                 switch(Interface->Type)
 249                 {
 250                 case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 251                 case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 252                 }
 253
 254                 conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 255                 conn->NextSequenceSend = rand();
 256
 257                 conn->Node.ImplInt = srv->NextID ++;
 258
 259                 // Hmm... Theoretically, this lock will never have to wait,
 260                 // as the interface is locked to the watching thread, and this
 261                 // runs in the watching thread. But, it's a good idea to have
 262                 // it, just in case
 263                 // Oh, wait, there is a case where a wildcard can be used
 264                 // (srv->Interface == NULL) so having the lock is a good idea
 265                 SHORTLOCK(&srv->lConnections);
 266                 if( !srv->Connections )
 267                         srv->Connections = conn;
 268                 else
 269                         srv->ConnectionsTail->Next = conn;
 270                 srv->ConnectionsTail = conn;
 271                 if(!srv->NewConnections)
 272                         srv->NewConnections = conn;
 273                 VFS_MarkAvaliable( &srv->Node, 1 );
 274                 SHORTREL(&srv->lConnections);
 275                 Semaphore_Signal(&srv->WaitingConnections, 1);
 276
 277                 // Send the SYN ACK
 278                 hdr->Flags |= TCP_FLAG_ACK;
 279                 hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 280                 hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 281                 hdr->DestPort = hdr->SourcePort;
 282                 hdr->SourcePort = htons(srv->Port);
 283                 hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 284                 TCP_SendPacket( conn, hdr, 0, NULL );
 285                 conn->NextSequenceSend ++;
 286                 return ;
 287         }
 288
 289         // Check Open Connections
 290         {
 291                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 292                 {
 293                         // Check that it is coming in on the same interface
 294                         if(conn->Interface != Interface)        continue;
 295
 296                         // Check Source Port
 297                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 298
 299                         // Check Source IP
 300                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 301                                 continue;
 302                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 303                                 continue;
 304
 305                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 306                         return ;
 307                 }
 308         }
 309
 310         Log_Log("TCP", "TCP_GetPacket: No Match");
 311 }
 312
 313 /**
 314  * \brief Handles a packet sent to a specific connection
 315  * \param Connection    TCP Connection pointer
 316  * \param Header        TCP Packet pointer
 317  * \param Length        Length of the packet
 318  */
 319 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 320 {
 321          int    dataLen;
 322         Uint32  sequence_num;
 323
 324         // Silently drop once finished
 325         // TODO: Check if this needs to be here
 326         if( Connection->State == TCP_ST_FINISHED ) {
 327                 Log_Log("TCP", "Packet ignored - connection finnished");
 328                 return ;
 329         }
 330
 331         // Syncronise sequence values
 332         if(Header->Flags & TCP_FLAG_SYN) {
 333                 // TODO: What if the packet also has data?
 334                 if( Connection->LastACKSequence != Connection->NextSequenceRcv )
 335                         TCP_INT_SendACK(Connection, "SYN");
 336                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
 337                 Connection->LastACKSequence = Connection->NextSequenceRcv;
 338         }
 339
 340         // Ackowledge a sent packet
 341         if(Header->Flags & TCP_FLAG_ACK) {
 342                 // TODO: Process an ACKed Packet
 343                 LOG("Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 344         }
 345
 346         // Get length of data
 347         dataLen = Length - (Header->DataOffset>>4)*4;
 348         LOG("dataLen = %i", dataLen);
 349         #if TCP_DEBUG
 350         Log_Debug("TCP", "State %i, dataLen = %x", Connection->State, dataLen);
 351         #endif
 352
 353         //
 354         // State Machine
 355         //
 356         switch( Connection->State )
 357         {
 358         // Pre-init connection?
 359         case TCP_ST_CLOSED:
 360                 Log_Log("TCP", "Packets to a closed connection?!");
 361                 break;
 362
 363         // --- Init States ---
 364         // SYN sent, expecting SYN-ACK Connection Opening
 365         case TCP_ST_SYN_SENT:
 366                 if( Header->Flags & TCP_FLAG_SYN )
 367                 {
 368                         Connection->NextSequenceRcv ++;
 369
 370                         if( Header->Flags & TCP_FLAG_ACK )
 371                         {
 372                                 Log_Log("TCP", "ACKing SYN-ACK");
 373                                 Connection->State = TCP_ST_OPEN;
 374                                 VFS_MarkFull(&Connection->Node, 0);
 375                         }
 376                         else
 377                         {
 378                                 Log_Log("TCP", "ACKing SYN");
 379                                 Connection->State = TCP_ST_SYN_RCVD;
 380                         }
 381                         Header->DestPort = Header->SourcePort;
 382                         Header->SourcePort = htons(Connection->LocalPort);
 383                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 384                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 385                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 386                         Header->Flags = TCP_FLAG_ACK;
 387                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 388                         TCP_SendPacket( Connection, Header, 0, NULL );
 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                         Log_Log("TCP", "Connection fully opened");
 398                         Connection->State = TCP_ST_OPEN;
 399                         VFS_MarkFull(&Connection->Node, 0);
 400                 }
 401                 break;
 402
 403         // --- Established State ---
 404         case TCP_ST_OPEN:
 405                 // - Handle State changes
 406                 //
 407                 if( Header->Flags & TCP_FLAG_FIN ) {
 408                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
 409                         VFS_MarkError(&Connection->Node, 1);
 410                         Connection->State = TCP_ST_CLOSE_WAIT;
 411 //                      Header->Flags &= ~TCP_FLAG_FIN;
 412                         // CLOSE WAIT requires the client to close (or does it?)
 413                         #if 0
 414
 415                         #endif
 416                 }
 417
 418                 // Check for an empty packet
 419                 if(dataLen == 0) {
 420                         if( Header->Flags == TCP_FLAG_ACK )
 421                         {
 422                                 Log_Log("TCP", "ACK only packet");
 423                                 return ;
 424                         }
 425                         Connection->NextSequenceRcv ++; // TODO: Is this right? (empty packet counts as one byte)
 426                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
 427                         TCP_INT_SendACK(Connection, "Empty");
 428                         #if 0
 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                         #endif
 436                         return ;
 437                 }
 438
 439                 // NOTES:
 440                 // Flags
 441                 //    PSH - Has Data?
 442                 // /NOTES
 443
 444                 sequence_num = ntohl(Header->SequenceNumber);
 445
 446                 LOG("0x%08x <= 0x%08x < 0x%08x",
 447                         Connection->NextSequenceRcv,
 448                         ntohl(Header->SequenceNumber),
 449                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
 450                         );
 451
 452                 // Is this packet the next expected packet?
 453                 if( sequence_num == Connection->NextSequenceRcv )
 454                 {
 455                          int    rv;
 456                         // Ooh, Goodie! Add it to the recieved list
 457                         rv = TCP_INT_AppendRecieved(Connection,
 458                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 459                                 dataLen
 460                                 );
 461                         if(rv != 0) {
 462                                 Log_Notice("TCP", "TCP_INT_AppendRecieved rv %i", rv);
 463                                 break;
 464                         }
 465                         LOG("0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 466                         Connection->NextSequenceRcv += dataLen;
 467
 468                         // TODO: This should be moved out of the watcher thread,
 469                         // so that a single lost packet on one connection doesn't cause
 470                         // all connections on the interface to lag.
 471                         // - Meh, no real issue, as the cache shouldn't be that large
 472                         TCP_INT_UpdateRecievedFromFuture(Connection);
 473
 474                         #if 1
 475                         // - Only send an ACK if we've had a burst
 476                         if( Connection->NextSequenceRcv > (Uint32)(TCP_DACK_THRESHOLD + Connection->LastACKSequence) )
 477                         {
 478                                 TCP_INT_SendACK(Connection, "DACK Burst");
 479                                 // - Extend TCP deferred ACK timer
 480                                 Time_RemoveTimer(Connection->DeferredACKTimer);
 481                         }
 482                         // - Schedule the deferred ACK timer (if already scheduled, this is a NOP)
 483                         Time_ScheduleTimer(Connection->DeferredACKTimer, TCP_DACK_TIMEOUT);
 484                         #else
 485                         TCP_INT_SendACK(Connection, "RX");
 486                         #endif
 487                 }
 488                 // Check if the packet is in window
 489                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 490                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 491                 {
 492                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 493                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 494                         Uint32  index;
 495
 496                         index = sequence_num % TCP_WINDOW_SIZE;
 497                         for( int 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, "Bad Seq");
 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         // Calculate length of contiguous bytes
 692          int    length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 693         Uint32  index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 694         for( int i = 0; i < length; i ++ )
 695         {
 696                  int    bit = index % 8;
 697                 Uint8   bitfield_byte = Connection->FuturePacketValidBytes[index / 8];
 698                 if( (bitfield_byte & (1 << bit)) == 0 ) {
 699                         length = i;
 700                         break;
 701                 }
 702
 703                 if( bitfield_byte == 0xFF ) {
 704                          int    inc = 8 - bit;
 705                         i += inc - 1;
 706                         index += inc;
 707                 }
 708                 else {
 709                         index ++;
 710                 }
 711                 if(index > TCP_WINDOW_SIZE)
 712                         index -= TCP_WINDOW_SIZE;
 713         }
 714
 715         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 716
 717         // Write data to to the ring buffer
 718         if( TCP_WINDOW_SIZE - index > length )
 719         {
 720                 // Simple case
 721                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 722         }
 723         else
 724         {
 725                  int    endLen = TCP_WINDOW_SIZE - index;
 726                 // 2-part case
 727                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 728                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 729         }
 730
 731         // Mark (now saved) bytes as invalid
 732         // - Align index
 733         while(index % 8 && length)
 734         {
 735                 Connection->FuturePacketData[index] = 0;
 736                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 737                 index ++;
 738                 if(index > TCP_WINDOW_SIZE)
 739                         index -= TCP_WINDOW_SIZE;
 740                 length --;
 741         }
 742         while( length > 7 )
 743         {
 744                 Connection->FuturePacketData[index] = 0;
 745                 Connection->FuturePacketValidBytes[index/8] = 0;
 746                 length -= 8;
 747                 index += 8;
 748                 if(index > TCP_WINDOW_SIZE)
 749                         index -= TCP_WINDOW_SIZE;
 750         }
 751         while(length)
 752         {
 753                 Connection->FuturePacketData[index] = 0;
 754                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 755                 index ++;
 756                 if(index > TCP_WINDOW_SIZE)
 757                         index -= TCP_WINDOW_SIZE;
 758                 length --;
 759         }
 760
 761         #else
 762         tTCPStoredPacket        *pkt;
 763         for(;;)
 764         {
 765                 SHORTLOCK( &Connection->lFuturePackets );
 766
 767                 // Clear out duplicates from cache
 768                 // - If a packet has just been recieved, and it is expected, then
 769                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 770                 //   packets in cache that are smaller than the next expected
 771                 //   are now defunct.
 772                 pkt = Connection->FuturePackets;
 773                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 774                 {
 775                         tTCPStoredPacket        *next = pkt->Next;
 776                         free(pkt);
 777                         pkt = next;
 778                 }
 779
 780                 // If there's no packets left in cache, stop looking
 781                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 782                         SHORTREL( &Connection->lFuturePackets );
 783                         return;
 784                 }
 785
 786                 // Delete packet from future list
 787                 Connection->FuturePackets = pkt->Next;
 788
 789                 // Release list
 790                 SHORTREL( &Connection->lFuturePackets );
 791
 792                 // Looks like we found one
 793                 TCP_INT_AppendRecieved(Connection, pkt->Data, pkt->Length);
 794                 Connection->NextSequenceRcv += pkt->Length;
 795                 free(pkt);
 796         }
 797         #endif
 798 }
 799
 800 void TCP_int_SendDelayedACK(void *ConnPtr)
 801 {
 802         TCP_INT_SendACK(ConnPtr, "DACK Timeout");
 803 }
 804
 805 void TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason)
 806 {
 807         tTCPHeader      hdr;
 808         // ACK Packet
 809         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
 810         hdr.DestPort = htons(Connection->RemotePort);
 811         hdr.SourcePort = htons(Connection->LocalPort);
 812         hdr.AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 813         hdr.SequenceNumber = htonl(Connection->NextSequenceSend);
 814         hdr.WindowSize = htons(TCP_WINDOW_SIZE);
 815         hdr.Flags = TCP_FLAG_ACK;       // TODO: Determine if SYN is wanted too
 816         hdr.Checksum = 0;       // TODO: Checksum
 817         hdr.UrgentPointer = 0;
 818         Log_Debug("TCP", "Sending ACK for 0x%08x (%s)", Connection->NextSequenceRcv, Reason);
 819         TCP_SendPacket( Connection, &hdr, 0, NULL );
 820         //Connection->NextSequenceSend ++;
 821         Connection->LastACKSequence = Connection->NextSequenceRcv;
 822 }
 823
 824 /**
 825  * \fn Uint16 TCP_GetUnusedPort()
 826  * \brief Gets an unused port and allocates it
 827  */
 828 Uint16 TCP_GetUnusedPort()
 829 {
 830         Uint16  ret;
 831
 832         // Get Next outbound port
 833         ret = giTCP_NextOutPort++;
 834         while( gaTCP_PortBitmap[ret/32] & (1UL << (ret%32)) )
 835         {
 836                 ret ++;
 837                 giTCP_NextOutPort++;
 838                 if(giTCP_NextOutPort == 0x10000) {
 839                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 840                 }
 841         }
 842
 843         // Mark the new port as used
 844         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 845
 846         return ret;
 847 }
 848
 849 /**
 850  * \fn int TCP_AllocatePort(Uint16 Port)
 851  * \brief Marks a port as used
 852  */
 853 int TCP_AllocatePort(Uint16 Port)
 854 {
 855         // Check if the port has already been allocated
 856         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 857                 return 0;
 858
 859         // Allocate
 860         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 861
 862         return 1;
 863 }
 864
 865 /**
 866  * \fn int TCP_DeallocatePort(Uint16 Port)
 867  * \brief Marks a port as unused
 868  */
 869 int TCP_DeallocatePort(Uint16 Port)
 870 {
 871         // Check if the port has already been allocated
 872         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 873                 return 0;
 874
 875         // Allocate
 876         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 877
 878         return 1;
 879 }
 880
 881 tTCPConnection *TCP_int_CreateConnection(tInterface *Interface, enum eTCPConnectionState State)
 882 {
 883         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
 884
 885         conn->State = State;
 886         conn->Interface = Interface;
 887         conn->LocalPort = -1;
 888         conn->RemotePort = -1;
 889
 890         conn->Node.ReferenceCount = 1;
 891         conn->Node.ImplPtr = conn;
 892         conn->Node.NumACLs = 1;
 893         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 894         conn->Node.Type = &gTCP_ClientNodeType;
 895         conn->Node.BufferFull = 1;      // Cleared when connection opens
 896
 897         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 898         #if 0
 899         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
 900         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
 901         #endif
 902
 903         #if CACHE_FUTURE_PACKETS_IN_BYTES
 904         // Future recieved data (ahead of the expected sequence number)
 905         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
 906         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
 907         #endif
 908
 909         conn->DeferredACKTimer = Time_AllocateTimer( TCP_int_SendDelayedACK, conn);
 910         return conn;
 911 }
 912
 913 // --- Server
 914 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 915 {
 916         tTCPListener    *srv;
 917
 918         srv = calloc( 1, sizeof(tTCPListener) );
 919
 920         if( srv == NULL ) {
 921                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 922                 return NULL;
 923         }
 924
 925         srv->Interface = Interface;
 926         srv->Port = 0;
 927         srv->NextID = 0;
 928         srv->Connections = NULL;
 929         srv->ConnectionsTail = NULL;
 930         srv->NewConnections = NULL;
 931         srv->Next = NULL;
 932         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 933         srv->Node.Size = -1;
 934         srv->Node.ImplPtr = srv;
 935         srv->Node.NumACLs = 1;
 936         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 937         srv->Node.Type = &gTCP_ServerNodeType;
 938
 939         SHORTLOCK(&glTCP_Listeners);
 940         srv->Next = gTCP_Listeners;
 941         gTCP_Listeners = srv;
 942         SHORTREL(&glTCP_Listeners);
 943
 944         return &srv->Node;
 945 }
 946
 947 /**
 948  * \brief Wait for a new connection and return the connection ID
 949  * \note Blocks until a new connection is made
 950  * \param Node  Server node
 951  * \param Pos   Position (ignored)
 952  */
 953 int TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Dest[FILENAME_MAX])
 954 {
 955         tTCPListener    *srv = Node->ImplPtr;
 956         tTCPConnection  *conn;
 957
 958         ENTER("pNode iPos", Node, Pos);
 959
 960         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 961         Semaphore_Wait( &srv->WaitingConnections, 1 );
 962
 963         SHORTLOCK(&srv->lConnections);
 964         // Increment the new list (the current connection is still on the
 965         // normal list)
 966         conn = srv->NewConnections;
 967         srv->NewConnections = conn->Next;
 968
 969         if( srv->NewConnections == NULL )
 970                 VFS_MarkAvaliable( Node, 0 );
 971
 972         SHORTREL( &srv->lConnections );
 973
 974         LOG("conn = %p", conn);
 975         LOG("srv->Connections = %p", srv->Connections);
 976         LOG("srv->NewConnections = %p", srv->NewConnections);
 977         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 978
 979         itoa(Dest, conn->Node.ImplInt, 16, 8, '0');
 980         Log_Log("TCP", "Thread %i got connection '%s'", Threads_GetTID(), Dest);
 981         LEAVE('i', 0);
 982         return 0;
 983 }
 984
 985 /**
 986  * \brief Gets a client connection node
 987  * \param Node  Server node
 988  * \param Name  Hexadecimal ID of the node
 989  */
 990 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags)
 991 {
 992         tTCPConnection  *conn;
 993         tTCPListener    *srv = Node->ImplPtr;
 994         char    tmp[9];
 995          int    id = atoi(Name);
 996
 997         ENTER("pNode sName", Node, Name);
 998
 999         // Check for a non-empty name
1000         if( Name[0] )
1001         {
1002                 // Sanity Check
1003                 itoa(tmp, id, 16, 8, '0');
1004                 if(strcmp(tmp, Name) != 0) {
1005                         LOG("'%s' != '%s' (%08x)", Name, tmp, id);
1006                         LEAVE('n');
1007                         return NULL;
1008                 }
1009
1010                 Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
1011                 Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
1012                 Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
1013
1014                 // Search
1015                 SHORTLOCK( &srv->lConnections );
1016                 for(conn = srv->Connections;
1017                         conn;
1018                         conn = conn->Next)
1019                 {
1020                         LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
1021                         if(conn->Node.ImplInt == id)    break;
1022                 }
1023                 SHORTREL( &srv->lConnections );
1024
1025                 // If not found, ret NULL
1026                 if(!conn) {
1027                         LOG("Connection %i not found", id);
1028                         LEAVE('n');
1029                         return NULL;
1030                 }
1031         }
1032         // Empty Name - Check for a new connection and if it's there, open it
1033         else
1034         {
1035                 SHORTLOCK( &srv->lConnections );
1036                 conn = srv->NewConnections;
1037                 if( conn != NULL )
1038                         srv->NewConnections = conn->Next;
1039                 VFS_MarkAvaliable( Node, srv->NewConnections != NULL );
1040                 SHORTREL( &srv->lConnections );
1041                 if( !conn ) {
1042                         LOG("No new connections");
1043                         LEAVE('n');
1044                         return NULL;
1045                 }
1046         }
1047
1048         // Return node
1049         LEAVE('p', &conn->Node);
1050         return &conn->Node;
1051 }
1052
1053 /**
1054  * \brief Handle IOCtl calls
1055  */
1056 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
1057 {
1058         tTCPListener    *srv = Node->ImplPtr;
1059
1060         switch(ID)
1061         {
1062         case 4: // Get/Set Port
1063                 if(!Data)       // Get Port
1064                         return srv->Port;
1065
1066                 if(srv->Port)   // Wait, you can't CHANGE the port
1067                         return -1;
1068
1069                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
1070                         return -1;
1071
1072                 // Permissions check
1073                 if(Threads_GetUID() != 0
1074                 && *(Uint16*)Data != 0
1075                 && *(Uint16*)Data < 1024)
1076                         return -1;
1077
1078                 // TODO: Check if a port is in use
1079
1080                 // Set Port
1081                 srv->Port = *(Uint16*)Data;
1082                 if(srv->Port == 0)      // Allocate a random port
1083                         srv->Port = TCP_GetUnusedPort();
1084                 else    // Else, mark this as used
1085                         TCP_AllocatePort(srv->Port);
1086
1087                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
1088
1089                 return srv->Port;
1090         }
1091         return 0;
1092 }
1093
1094 void TCP_Server_Close(tVFS_Node *Node)
1095 {
1096         free(Node->ImplPtr);
1097 }
1098
1099 // --- Client
1100 /**
1101  * \brief Create a client node
1102  */
1103 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1104 {
1105         tTCPConnection  *conn = TCP_int_CreateConnection(Interface, TCP_ST_CLOSED);
1106
1107         SHORTLOCK(&glTCP_OutbountCons);
1108         conn->Next = gTCP_OutbountCons;
1109         gTCP_OutbountCons = conn;
1110         SHORTREL(&glTCP_OutbountCons);
1111
1112         return &conn->Node;
1113 }
1114
1115 /**
1116  * \brief Wait for a packet and return it
1117  * \note If \a Length is smaller than the size of the packet, the rest
1118  *       of the packet's data will be discarded.
1119  */
1120 size_t TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
1121 {
1122         tTCPConnection  *conn = Node->ImplPtr;
1123         size_t  len;
1124
1125         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1126         LOG("conn = %p {State:%i}", conn, conn->State);
1127
1128         // If the connection has been closed (state > ST_OPEN) then clear
1129         // any stale data in the buffer (until it is empty (until it is empty))
1130         if( conn->State > TCP_ST_OPEN )
1131         {
1132                 Mutex_Acquire( &conn->lRecievedPackets );
1133                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1134                 Mutex_Release( &conn->lRecievedPackets );
1135
1136                 if( len == 0 ) {
1137                         VFS_MarkAvaliable(Node, 0);
1138                         errno = 0;
1139                         LEAVE('i', -1);
1140                         return -1;
1141                 }
1142
1143                 LEAVE('i', len);
1144                 return len;
1145         }
1146
1147         // Wait
1148         {
1149                 tTime   *timeout = NULL;
1150                 tTime   timeout_zero = 0;
1151                 if( Flags & VFS_IOFLAG_NOBLOCK )
1152                         timeout = &timeout_zero;
1153                 if( !VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, timeout, "TCP_Client_Read") ) {
1154                         errno = EWOULDBLOCK;
1155                         LEAVE('i', -1);
1156                         return -1;
1157                 }
1158         }
1159
1160         // Lock list and read as much as possible (up to `Length`)
1161         Mutex_Acquire( &conn->lRecievedPackets );
1162         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1163
1164         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1165                 LOG("Marking as none avaliable (len = %i)", len);
1166                 VFS_MarkAvaliable(Node, 0);
1167         }
1168
1169         // Release the lock (we don't need it any more)
1170         Mutex_Release( &conn->lRecievedPackets );
1171
1172         LEAVE('i', len);
1173         return len;
1174 }
1175
1176 /**
1177  * \brief Send a data packet on a connection
1178  */
1179 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, const void *Data)
1180 {
1181         char    buf[sizeof(tTCPHeader)+Length];
1182         tTCPHeader      *packet = (void*)buf;
1183
1184         // - Stop Delayed ACK timer (as this data packet ACKs)
1185         Time_RemoveTimer(Connection->DeferredACKTimer);
1186
1187         packet->SourcePort = htons(Connection->LocalPort);
1188         packet->DestPort = htons(Connection->RemotePort);
1189         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1190         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1191
1192         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1193         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1194         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1195         packet->UrgentPointer = 0;
1196
1197         memcpy(packet->Options, Data, Length);
1198
1199         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1200 #if HEXDUMP_OUTGOING
1201         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1202 #endif
1203
1204         TCP_SendPacket( Connection, packet, Length, Data );
1205
1206         Connection->NextSequenceSend += Length;
1207 }
1208
1209 /**
1210  * \brief Send some bytes on a connection
1211  */
1212 size_t TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
1213 {
1214         tTCPConnection  *conn = Node->ImplPtr;
1215         size_t  rem = Length;
1216
1217         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1218
1219 //      #if DEBUG
1220 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1221 //              Buffer, Length);
1222 //      #endif
1223
1224         // Don't allow a write to a closed connection
1225         if( conn->State > TCP_ST_OPEN ) {
1226                 VFS_MarkError(Node, 1);
1227                 errno = 0;
1228                 LEAVE('i', -1);
1229                 return -1;
1230         }
1231
1232         // Wait
1233         {
1234                 tTime   *timeout = NULL;
1235                 tTime   timeout_zero = 0;
1236                 if( Flags & VFS_IOFLAG_NOBLOCK )
1237                         timeout = &timeout_zero;
1238                 if( !VFS_SelectNode(Node, VFS_SELECT_WRITE|VFS_SELECT_ERROR, timeout, "TCP_Client_Write") ) {
1239                         errno = EWOULDBLOCK;
1240                         LEAVE('i', -1);
1241                         return -1;
1242                 }
1243         }
1244
1245         do
1246         {
1247                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1248
1249                 #if 0
1250                 // Wait for space in the buffer
1251                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1252
1253                 // Save data to buffer (and update the length read by the ammount written)
1254                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1255                 #endif
1256
1257                 // Send packet
1258                 TCP_INT_SendDataPacket(conn, len, Buffer);
1259
1260                 Buffer += len;
1261                 rem -= len;
1262         } while( rem > 0 );
1263
1264         LEAVE('i', Length);
1265         return Length;
1266 }
1267
1268 /**
1269  * \brief Open a connection to another host using TCP
1270  * \param Conn  Connection structure
1271  */
1272 void TCP_StartConnection(tTCPConnection *Conn)
1273 {
1274         tTCPHeader      hdr = {0};
1275
1276         Conn->State = TCP_ST_SYN_SENT;
1277
1278         hdr.SourcePort = htons(Conn->LocalPort);
1279         hdr.DestPort = htons(Conn->RemotePort);
1280         Conn->NextSequenceSend = rand();
1281         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1282         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1283         hdr.Flags = TCP_FLAG_SYN;
1284         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1285         hdr.Checksum = 0;       // TODO
1286
1287         TCP_SendPacket( Conn, &hdr, 0, NULL );
1288
1289         Conn->NextSequenceSend ++;
1290         Conn->State = TCP_ST_SYN_SENT;
1291
1292         return ;
1293 }
1294
1295 /**
1296  * \brief Control a client socket
1297  */
1298 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1299 {
1300         tTCPConnection  *conn = Node->ImplPtr;
1301
1302         ENTER("pNode iID pData", Node, ID, Data);
1303
1304         switch(ID)
1305         {
1306         case 4: // Get/Set local port
1307                 if(!Data)
1308                         LEAVE_RET('i', conn->LocalPort);
1309                 if(conn->State != TCP_ST_CLOSED)
1310                         LEAVE_RET('i', -1);
1311                 if(!CheckMem(Data, sizeof(Uint16)))
1312                         LEAVE_RET('i', -1);
1313
1314                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1315                         LEAVE_RET('i', -1);
1316
1317                 conn->LocalPort = *(Uint16*)Data;
1318                 LEAVE_RET('i', conn->LocalPort);
1319
1320         case 5: // Get/Set remote port
1321                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1322                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1323                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1324                 conn->RemotePort = *(Uint16*)Data;
1325                 LEAVE_RET('i', conn->RemotePort);
1326
1327         case 6: // Set Remote IP
1328                 if( conn->State != TCP_ST_CLOSED )
1329                         LEAVE_RET('i', -1);
1330                 if( conn->Interface->Type == 4 )
1331                 {
1332                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1333                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1334                 }
1335                 else if( conn->Interface->Type == 6 )
1336                 {
1337                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1338                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1339                 }
1340                 LEAVE_RET('i', 0);
1341
1342         case 7: // Connect
1343                 if(conn->LocalPort == 0xFFFF)
1344                         conn->LocalPort = TCP_GetUnusedPort();
1345                 if(conn->RemotePort == -1)
1346                         LEAVE_RET('i', 0);
1347
1348                 {
1349                         tTime   timeout = conn->Interface->TimeoutDelay;
1350
1351                         TCP_StartConnection(conn);
1352                         VFS_SelectNode(&conn->Node, VFS_SELECT_WRITE, &timeout, "TCP Connection");
1353                         if( conn->State == TCP_ST_SYN_SENT )
1354                                 LEAVE_RET('i', 0);
1355                 }
1356
1357                 LEAVE_RET('i', 1);
1358
1359         // Get recieve buffer length
1360         case 8:
1361                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1362         }
1363
1364         return 0;
1365 }
1366
1367 void TCP_Client_Close(tVFS_Node *Node)
1368 {
1369         tTCPConnection  *conn = Node->ImplPtr;
1370         tTCPHeader      packet;
1371
1372         ENTER("pNode", Node);
1373
1374         ASSERT(Node->ReferenceCount != 0);
1375
1376         if( Node->ReferenceCount > 1 ) {
1377                 Node->ReferenceCount --;
1378                 LOG("Dereference only");
1379                 LEAVE('-');
1380                 return ;
1381         }
1382
1383         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1384         {
1385                 packet.SourcePort = htons(conn->LocalPort);
1386                 packet.DestPort = htons(conn->RemotePort);
1387                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1388                 packet.WindowSize = TCP_WINDOW_SIZE;
1389
1390                 packet.AcknowlegementNumber = 0;
1391                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1392                 packet.Flags = TCP_FLAG_FIN;
1393
1394                 TCP_SendPacket( conn, &packet, 0, NULL );
1395         }
1396
1397         switch( conn->State )
1398         {
1399         case TCP_ST_CLOSED:
1400                 Log_Warning("TCP", "Closing connection that was never opened");
1401                 break;
1402         case TCP_ST_CLOSE_WAIT:
1403                 conn->State = TCP_ST_LAST_ACK;
1404                 break;
1405         case TCP_ST_OPEN:
1406                 conn->State = TCP_ST_FIN_WAIT1;
1407                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1408                 break;
1409         default:
1410                 Log_Warning("TCP", "Unhandled connection state %i in TCP_Client_Close",
1411                         conn->State);
1412                 break;
1413         }
1414
1415         Time_RemoveTimer(conn->DeferredACKTimer);
1416         Time_FreeTimer(conn->DeferredACKTimer);
1417         free(conn);
1418
1419         LEAVE('-');
1420 }
1421
1422 /**
1423  * \brief Checks if a value is between two others (after taking into account wrapping)
1424  */
1425 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1426 {
1427         if( MaxValue < 0xFFFFFFFF )
1428         {
1429                 Lower %= MaxValue + 1;
1430                 Value %= MaxValue + 1;
1431                 Higher %= MaxValue + 1;
1432         }
1433
1434         // Simple Case, no wrap ?
1435         //       Lower Value Higher
1436         // | ... + ... + ... + ... |
1437
1438         if( Lower < Higher ) {
1439                 return Lower < Value && Value < Higher;
1440         }
1441         // Higher has wrapped below lower
1442
1443         // Value > Lower ?
1444         //       Higher Lower Value
1445         // | ... +  ... + ... + ... |
1446         if( Value > Lower ) {
1447                 return 1;
1448         }
1449
1450         // Value < Higher ?
1451         //       Value Higher Lower
1452         // | ... + ... +  ... + ... |
1453         if( Value < Higher ) {
1454                 return 1;
1455         }
1456
1457         return 0;
1458 }