Modules/IPStack/tcp.c

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