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 "tcp.h"
   9
  10 #define TCP_MIN_DYNPORT 0xC000
  11 #define TCP_MAX_HALFOPEN        1024    // Should be enough
  12
  13 #define TCP_MAX_PACKET_SIZE     1024
  14 #define TCP_WINDOW_SIZE 0x2000
  15 #define TCP_RECIEVE_BUFFER_SIZE 0x4000
  16
  17 // === PROTOTYPES ===
  18 void    TCP_Initialise();
  19 void    TCP_StartConnection(tTCPConnection *Conn);
  20 void    TCP_SendPacket(tTCPConnection *Conn, size_t Length, tTCPHeader *Data);
  21 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  22 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  23 void    TCP_INT_AppendRecieved(tTCPConnection *Connection, tTCPStoredPacket *Ptk);
  24 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  25 Uint16  TCP_GetUnusedPort();
  26  int    TCP_AllocatePort(Uint16 Port);
  27  int    TCP_DeallocatePort(Uint16 Port);
  28 // --- Server
  29 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  30 char    *TCP_Server_ReadDir(tVFS_Node *Node, int Pos);
  31 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, char *Name);
  32  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  33 void    TCP_Server_Close(tVFS_Node *Node);
  34 // --- Client
  35 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  36 Uint64  TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  37 Uint64  TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  38  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  39 void    TCP_Client_Close(tVFS_Node *Node);
  40
  41 // === TEMPLATES ===
  42 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  43 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  44
  45 // === GLOBALS ===
  46  int    giTCP_NumHalfopen = 0;
  47 tSpinlock       glTCP_Listeners;
  48 tTCPListener    *gTCP_Listeners;
  49 tSpinlock       glTCP_OutbountCons;
  50 tTCPConnection  *gTCP_OutbountCons;
  51 Uint32  gaTCP_PortBitmap[0x800];
  52  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  53
  54 // === CODE ===
  55 /**
  56  * \brief Initialise the TCP Layer
  57  *
  58  * Registers the client and server files and the GetPacket callback
  59  */
  60 void TCP_Initialise()
  61 {
  62         IPStack_AddFile(&gTCP_ServerFile);
  63         IPStack_AddFile(&gTCP_ClientFile);
  64         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  65 }
  66
  67 /**
  68  * \brief Sends a packet from the specified connection, calculating the checksums
  69  * \param Conn  Connection
  70  * \param Length        Length of data
  71  * \param Data  Packet data (cast as a TCP Header)
  72  */
  73 void TCP_SendPacket( tTCPConnection *Conn, size_t Length, tTCPHeader *Data )
  74 {
  75         size_t  buflen;
  76         Uint32  *buf;
  77         switch( Conn->Interface->Type )
  78         {
  79         case 4: // Append IPv4 Pseudo Header
  80                 buflen = 4 + 4 + 4 + ((Length+1)&~1);
  81                 buf = malloc( buflen );
  82                 buf[0] = Conn->Interface->IP4.Address.L;
  83                 buf[1] = Conn->RemoteIP.v4.L;
  84                 buf[2] = (htons(Length)<<16) | (6<<8) | 0;
  85                 Data->Checksum = 0;
  86                 memcpy( &buf[3], Data, Length );
  87                 Data->Checksum = IPv4_Checksum( buf, buflen );
  88                 free(buf);
  89                 IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, Length, Data);
  90                 break;
  91         }
  92 }
  93
  94 /**
  95  * \brief Handles a packet from the IP Layer
  96  * \param Interface     Interface the packet arrived from
  97  * \param Address       Pointer to the addres structure
  98  * \param Length        Size of packet in bytes
  99  * \param Buffer        Packet data
 100  */
 101 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 102 {
 103         tTCPHeader      *hdr = Buffer;
 104         tTCPListener    *srv;
 105         tTCPConnection  *conn;
 106
 107         Log_Log("TCP", "SourcePort = %i, DestPort = %i",
 108                 ntohs(hdr->SourcePort), ntohs(hdr->DestPort));
 109 /*
 110         Log_Log("TCP", "SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 111         Log_Log("TCP", "AcknowlegementNumber = 0x%x", ntohl(hdr->AcknowlegementNumber));
 112         Log_Log("TCP", "DataOffset = %i", hdr->DataOffset >> 4);
 113         Log_Log("TCP", "Flags = {");
 114         Log_Log("TCP", "  CWR = %B, ECE = %B",
 115                 !!(hdr->Flags & TCP_FLAG_CWR), !!(hdr->Flags & TCP_FLAG_ECE));
 116         Log_Log("TCP", "  URG = %B, ACK = %B",
 117                 !!(hdr->Flags & TCP_FLAG_URG), !!(hdr->Flags & TCP_FLAG_ACK));
 118         Log_Log("TCP", "  PSH = %B, RST = %B",
 119                 !!(hdr->Flags & TCP_FLAG_PSH), !!(hdr->Flags & TCP_FLAG_RST));
 120         Log_Log("TCP", "  SYN = %B, FIN = %B",
 121                 !!(hdr->Flags & TCP_FLAG_SYN), !!(hdr->Flags & TCP_FLAG_FIN));
 122         Log_Log("TCP", "}");
 123         Log_Log("TCP", "WindowSize = %i", htons(hdr->WindowSize));
 124         Log_Log("TCP", "Checksum = 0x%x", htons(hdr->Checksum));
 125         Log_Log("TCP", "UrgentPointer = 0x%x", htons(hdr->UrgentPointer));
 126 */
 127
 128         if( Length > (hdr->DataOffset >> 4)*4 )
 129         {
 130                 Debug_HexDump(
 131                         "[TCP  ] Packet Data = ",
 132                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 133                         Length - (hdr->DataOffset >> 4)*4
 134                         );
 135         }
 136
 137         // Check Servers
 138         {
 139                 for( srv = gTCP_Listeners; srv; srv = srv->Next )
 140                 {
 141                         // Check if the server is active
 142                         if(srv->Port == 0)      continue;
 143                         // Check the interface
 144                         if(srv->Interface && srv->Interface != Interface)       continue;
 145                         // Check the destination port
 146                         if(srv->Port != htons(hdr->DestPort))   continue;
 147
 148                         Log_Log("TCP", "Matches server %p", srv);
 149                         // Is this in an established connection?
 150                         for( conn = srv->Connections; conn; conn = conn->Next )
 151                         {
 152                                 Log_Log("TCP", "conn->Interface(%p) == Interface(%p)",
 153                                         conn->Interface, Interface);
 154                                 // Check that it is coming in on the same interface
 155                                 if(conn->Interface != Interface)        continue;
 156
 157                                 // Check Source Port
 158                                 Log_Log("TCP", "conn->RemotePort(%i) == hdr->SourcePort(%i)",
 159                                         conn->RemotePort, ntohs(hdr->SourcePort));
 160                                 if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 161
 162                                 // Check Source IP
 163                                 if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 164                                         continue;
 165                                 if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 166                                         continue;
 167
 168                                 Log_Log("TCP", "Matches connection %p", conn);
 169                                 // We have a response!
 170                                 TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 171
 172                                 return;
 173                         }
 174
 175                         Log_Log("TCP", "Opening Connection");
 176                         // Open a new connection (well, check that it's a SYN)
 177                         if(hdr->Flags != TCP_FLAG_SYN) {
 178                                 Log_Log("TCP", "Packet is not a SYN");
 179                                 return ;
 180                         }
 181
 182                         // TODO: Check for halfopen max
 183
 184                         conn = calloc(1, sizeof(tTCPConnection));
 185                         conn->State = TCP_ST_HALFOPEN;
 186                         conn->LocalPort = srv->Port;
 187                         conn->RemotePort = ntohs(hdr->SourcePort);
 188                         conn->Interface = Interface;
 189
 190                         switch(Interface->Type)
 191                         {
 192                         case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 193                         case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 194                         }
 195
 196                         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 197
 198                         conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 199                         conn->NextSequenceSend = rand();
 200
 201                         // Create node
 202                         conn->Node.NumACLs = 1;
 203                         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 204                         conn->Node.ImplPtr = conn;
 205                         conn->Node.ImplInt = srv->NextID ++;
 206                         conn->Node.Read = TCP_Client_Read;
 207                         conn->Node.Write = TCP_Client_Write;
 208                         //conn->Node.Close = TCP_SrvConn_Close;
 209
 210                         // Hmm... Theoretically, this lock will never have to wait,
 211                         // as the interface is locked to the watching thread, and this
 212                         // runs in the watching thread. But, it's a good idea to have
 213                         // it, just in case
 214                         // Oh, wait, there is a case where a wildcard can be used
 215                         // (srv->Interface == NULL) so having the lock is a good idea
 216                         LOCK(&srv->lConnections);
 217                         if( !srv->Connections )
 218                                 srv->Connections = conn;
 219                         else
 220                                 srv->ConnectionsTail->Next = conn;
 221                         srv->ConnectionsTail = conn;
 222                         if(!srv->NewConnections)
 223                                 srv->NewConnections = conn;
 224                         RELEASE(&srv->lConnections);
 225
 226                         // Send the SYN ACK
 227                         hdr->Flags |= TCP_FLAG_ACK;
 228                         hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 229                         hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 230                         hdr->DestPort = hdr->SourcePort;
 231                         hdr->SourcePort = htons(srv->Port);
 232                         hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 233                         TCP_SendPacket( conn, sizeof(tTCPHeader), hdr );
 234                         conn->NextSequenceSend ++;
 235                         return ;
 236                 }
 237         }
 238
 239
 240         // Check Open Connections
 241         {
 242                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 243                 {
 244                         // Check that it is coming in on the same interface
 245                         if(conn->Interface != Interface)        continue;
 246
 247                         // Check Source Port
 248                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 249
 250                         // Check Source IP
 251                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 252                                 continue;
 253                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 254                                 continue;
 255
 256                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 257                         return ;
 258                 }
 259         }
 260
 261         Log_Log("TCP", "No Match");
 262 }
 263
 264 /**
 265  * \brief Handles a packet sent to a specific connection
 266  * \param Connection    TCP Connection pointer
 267  * \param Header        TCP Packet pointer
 268  * \param Length        Length of the packet
 269  */
 270 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 271 {
 272         tTCPStoredPacket        *pkt;
 273          int    dataLen;
 274
 275         if(Header->Flags & TCP_FLAG_SYN) {
 276                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber) + 1;
 277         }
 278
 279         if( Connection->State == TCP_ST_SYN_SENT )
 280         {
 281                 if( (Header->Flags & (TCP_FLAG_SYN|TCP_FLAG_ACK)) == (TCP_FLAG_SYN|TCP_FLAG_ACK) ) {
 282
 283                         Header->DestPort = Header->SourcePort;
 284                         Header->SourcePort = htons(Connection->LocalPort);
 285                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 286                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 287                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 288                         Header->Flags = TCP_FLAG_ACK;
 289                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 290                         Log_Log("TCP", "ACKing SYN-ACK");
 291                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 292                         Connection->State = TCP_ST_OPEN;
 293                 }
 294         }
 295
 296         // Get length of data
 297         dataLen = Length - (Header->DataOffset>>4)*4;
 298         Log_Log("TCP", "HandleConnectionPacket - dataLen = %i", dataLen);
 299
 300         if(Header->Flags & TCP_FLAG_ACK) {
 301                 // TODO: Process an ACKed Packet
 302                 Log_Log("TCP", "Conn %p, Packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 303         }
 304
 305         // TODO: Check what to do here
 306         if(Header->Flags & TCP_FLAG_FIN) {
 307                 if( Connection->State == TCP_ST_FIN_SENT ) {
 308                         Connection->State = TCP_ST_FINISHED;
 309                         return ;
 310                 }
 311                 else {
 312                         Connection->State = TCP_ST_FINISHED;
 313                         Header->DestPort = Header->SourcePort;
 314                         Header->SourcePort = htons(Connection->LocalPort);
 315                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 316                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 317                         Header->Flags = TCP_FLAG_ACK;
 318                         TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 319                         return ;
 320                 }
 321         }
 322
 323         if(dataLen == 0) {
 324                 Log_Log("TCP", "Empty Packet");
 325                 return ;
 326         }
 327
 328         // NOTES:
 329         // Flags
 330         //    PSH - Has Data?
 331         // /NOTES
 332
 333         // Allocate and fill cached packet
 334         pkt = malloc( dataLen + sizeof(tTCPStoredPacket) );
 335         pkt->Next = NULL;
 336         pkt->Sequence = ntohl(Header->SequenceNumber);
 337         pkt->Length = dataLen;
 338         memcpy(pkt->Data, (Uint8*)Header + (Header->DataOffset>>4)*4, dataLen);
 339
 340         // Is this packet the next expected packet?
 341         // TODO: Fix this to check if the packet is in the window.
 342         if( pkt->Sequence != Connection->NextSequenceRcv )
 343         {
 344                 tTCPStoredPacket        *tmp, *prev = NULL;
 345
 346                 Log_Log("TCP", "Out of sequence packet (0x%08x != 0x%08x)",
 347                         pkt->Sequence, Connection->NextSequenceRcv);
 348
 349                 // No? Well, let's cache it and look at it later
 350                 LOCK( &Connection->lFuturePackets );
 351                 for(tmp = Connection->FuturePackets;
 352                         tmp;
 353                         prev = tmp, tmp = tmp->Next)
 354                 {
 355                         if(tmp->Sequence > pkt->Sequence)       break;
 356                 }
 357                 if(prev)
 358                         prev->Next = pkt;
 359                 else
 360                         Connection->FuturePackets = pkt;
 361                 pkt->Next = tmp;
 362                 RELEASE( &Connection->lFuturePackets );
 363         }
 364         else
 365         {
 366                 // Ooh, Goodie! Add it to the recieved list
 367                 TCP_INT_AppendRecieved(Connection, pkt);
 368                 free(pkt);
 369                 Log_Log("TCP", "0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 370                 Connection->NextSequenceRcv += dataLen;
 371
 372                 // TODO: This should be moved out of the watcher thread,
 373                 // so that a single lost packet on one connection doesn't cause
 374                 // all connections on the interface to lag.
 375                 TCP_INT_UpdateRecievedFromFuture(Connection);
 376
 377                 // ACK Packet
 378                 Header->DestPort = Header->SourcePort;
 379                 Header->SourcePort = htons(Connection->LocalPort);
 380                 Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 381                 Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 382                 Header->WindowSize = htons(TCP_WINDOW_SIZE);
 383                 Header->Flags &= TCP_FLAG_SYN;  // Eliminate all flags save for SYN
 384                 Header->Flags |= TCP_FLAG_ACK;  // Add ACK
 385                 Log_Log("TCP", "Sending ACK for 0x%08x", Connection->NextSequenceRcv);
 386                 TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
 387                 //Connection->NextSequenceSend ++;
 388         }
 389 }
 390
 391 /**
 392  * \brief Appends a packet to the recieved list
 393  * \param Connection    Connection structure
 394  * \param Pkt   Packet structure on heap
 395  */
 396 void TCP_INT_AppendRecieved(tTCPConnection *Connection, tTCPStoredPacket *Pkt)
 397 {
 398         LOCK( &Connection->lRecievedPackets );
 399         if(Connection->RecievedBuffer->Length + Pkt->Length > Connection->RecievedBuffer->Space )
 400         {
 401                 Log_Error("TCP", "Buffer filled, packet dropped (%s)",
 402                 //      TCP_INT_DumpConnection(Connection)
 403                         ""
 404                         );
 405                 return ;
 406         }
 407
 408         RingBuffer_Write( Connection->RecievedBuffer, Pkt->Data, Pkt->Length );
 409
 410         RELEASE( &Connection->lRecievedPackets );
 411 }
 412
 413 /**
 414  * \brief Updates the connections recieved list from the future list
 415  * \param Connection    Connection structure
 416  *
 417  * Updates the recieved packets list with packets from the future (out
 418  * of order) packets list that are now able to be added in direct
 419  * sequence.
 420  */
 421 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 422 {
 423         tTCPStoredPacket        *pkt, *prev;
 424         for(;;)
 425         {
 426                 prev = NULL;
 427                 // Look for the next expected packet in the cache.
 428                 LOCK( &Connection->lFuturePackets );
 429                 for(pkt = Connection->FuturePackets;
 430                         pkt && pkt->Sequence < Connection->NextSequenceRcv;
 431                         prev = pkt, pkt = pkt->Next);
 432
 433                 // If we can't find the expected next packet, stop looking
 434                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 435                         RELEASE( &Connection->lFuturePackets );
 436                         return;
 437                 }
 438
 439                 // Delete packet from future list
 440                 if(prev)
 441                         prev->Next = pkt->Next;
 442                 else
 443                         Connection->FuturePackets = pkt->Next;
 444
 445                 // Release list
 446                 RELEASE( &Connection->lFuturePackets );
 447
 448                 // Looks like we found one
 449                 TCP_INT_AppendRecieved(Connection, pkt);
 450                 Connection->NextSequenceRcv += pkt->Length;
 451                 free(pkt);
 452         }
 453 }
 454
 455 /**
 456  * \fn Uint16 TCP_GetUnusedPort()
 457  * \brief Gets an unused port and allocates it
 458  */
 459 Uint16 TCP_GetUnusedPort()
 460 {
 461         Uint16  ret;
 462
 463         // Get Next outbound port
 464         ret = giTCP_NextOutPort++;
 465         while( gaTCP_PortBitmap[ret/32] & (1 << (ret%32)) )
 466         {
 467                 ret ++;
 468                 giTCP_NextOutPort++;
 469                 if(giTCP_NextOutPort == 0x10000) {
 470                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 471                 }
 472         }
 473
 474         // Mark the new port as used
 475         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 476
 477         return ret;
 478 }
 479
 480 /**
 481  * \fn int TCP_AllocatePort(Uint16 Port)
 482  * \brief Marks a port as used
 483  */
 484 int TCP_AllocatePort(Uint16 Port)
 485 {
 486         // Check if the port has already been allocated
 487         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 488                 return 0;
 489
 490         // Allocate
 491         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 492
 493         return 1;
 494 }
 495
 496 /**
 497  * \fn int TCP_DeallocatePort(Uint16 Port)
 498  * \brief Marks a port as unused
 499  */
 500 int TCP_DeallocatePort(Uint16 Port)
 501 {
 502         // Check if the port has already been allocated
 503         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 504                 return 0;
 505
 506         // Allocate
 507         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 508
 509         return 1;
 510 }
 511
 512 // --- Server
 513 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 514 {
 515         tTCPListener    *srv;
 516
 517         srv = malloc( sizeof(tTCPListener) );
 518
 519         if( srv == NULL ) {
 520                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 521                 return NULL;
 522         }
 523
 524         srv->Interface = Interface;
 525         srv->Port = 0;
 526         srv->NextID = 0;
 527         srv->Connections = NULL;
 528         srv->ConnectionsTail = NULL;
 529         srv->NewConnections = NULL;
 530         srv->Next = NULL;
 531         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 532         srv->Node.Size = -1;
 533         srv->Node.ImplPtr = srv;
 534         srv->Node.NumACLs = 1;
 535         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 536         srv->Node.ReadDir = TCP_Server_ReadDir;
 537         srv->Node.FindDir = TCP_Server_FindDir;
 538         srv->Node.IOCtl = TCP_Server_IOCtl;
 539         srv->Node.Close = TCP_Server_Close;
 540
 541         LOCK(&glTCP_Listeners);
 542         srv->Next = gTCP_Listeners;
 543         gTCP_Listeners = srv;
 544         RELEASE(&glTCP_Listeners);
 545
 546         return &srv->Node;
 547 }
 548
 549 /**
 550  * \brief Wait for a new connection and return the connection ID
 551  * \note Blocks until a new connection is made
 552  * \param Node  Server node
 553  * \param Pos   Position (ignored)
 554  */
 555 char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
 556 {
 557         tTCPListener    *srv = Node->ImplPtr;
 558         tTCPConnection  *conn;
 559         char    *ret;
 560
 561         ENTER("pNode iPos", Node, Pos);
 562
 563         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 564         for(;;)
 565         {
 566                 LOCK( &srv->lConnections );
 567                 if( srv->NewConnections != NULL )       break;
 568                 RELEASE( &srv->lConnections );
 569                 Threads_Yield();
 570                 continue;
 571         }
 572
 573
 574         // Increment the new list (the current connection is still on the
 575         // normal list)
 576         conn = srv->NewConnections;
 577         srv->NewConnections = conn->Next;
 578
 579         LOG("conn = %p", conn);
 580         LOG("srv->Connections = %p", srv->Connections);
 581         LOG("srv->NewConnections = %p", srv->NewConnections);
 582         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 583
 584         RELEASE( &srv->lConnections );
 585
 586         ret = malloc(9);
 587         itoa(ret, conn->Node.ImplInt, 16, 8, '0');
 588         Log_Log("TCP", "Thread %i got '%s'", Threads_GetTID(), ret);
 589         LEAVE('s', ret);
 590         return ret;
 591 }
 592
 593 /**
 594  * \brief Gets a client connection node
 595  * \param Node  Server node
 596  * \param Name  Hexadecimal ID of the node
 597  */
 598 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, char *Name)
 599 {
 600         tTCPConnection  *conn;
 601         tTCPListener    *srv = Node->ImplPtr;
 602         char    tmp[9];
 603          int    id = atoi(Name);
 604
 605         ENTER("pNode sName", Node, Name);
 606
 607         // Sanity Check
 608         itoa(tmp, id, 16, 8, '0');
 609         if(strcmp(tmp, Name) != 0) {
 610                 LOG("'%s' != '%s' (%08x)", Name, tmp, id);
 611                 LEAVE('n');
 612                 return NULL;
 613         }
 614
 615         Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
 616         Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
 617         Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 618
 619         // Search
 620         LOCK( &srv->lConnections );
 621         for(conn = srv->Connections;
 622                 conn;
 623                 conn = conn->Next)
 624         {
 625                 LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
 626                 if(conn->Node.ImplInt == id)    break;
 627         }
 628         RELEASE( &srv->lConnections );
 629
 630         // If not found, ret NULL
 631         if(!conn) {
 632                 LOG("Connection %i not found", id);
 633                 LEAVE('n');
 634                 return NULL;
 635         }
 636
 637         // Return node
 638         LEAVE('p', &conn->Node);
 639         return &conn->Node;
 640 }
 641
 642 /**
 643  * \brief Handle IOCtl calls
 644  */
 645 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
 646 {
 647         tTCPListener    *srv = Node->ImplPtr;
 648
 649         switch(ID)
 650         {
 651         case 4: // Get/Set Port
 652                 if(!Data)       // Get Port
 653                         return srv->Port;
 654
 655                 if(srv->Port)   // Wait, you can't CHANGE the port
 656                         return -1;
 657
 658                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
 659                         return -1;
 660
 661                 // Permissions check
 662                 if(Threads_GetUID() != 0
 663                 && *(Uint16*)Data != 0
 664                 && *(Uint16*)Data < 1024)
 665                         return -1;
 666
 667                 // TODO: Check if a port is in use
 668
 669                 // Set Port
 670                 srv->Port = *(Uint16*)Data;
 671                 if(srv->Port == 0)      // Allocate a random port
 672                         srv->Port = TCP_GetUnusedPort();
 673                 else    // Else, mark this as used
 674                         TCP_AllocatePort(srv->Port);
 675
 676                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
 677
 678                 return srv->Port;
 679         }
 680         return 0;
 681 }
 682
 683 void TCP_Server_Close(tVFS_Node *Node)
 684 {
 685         free(Node->ImplPtr);
 686 }
 687
 688 // --- Client
 689 /**
 690  * \brief Create a client node
 691  */
 692 tVFS_Node *TCP_Client_Init(tInterface *Interface)
 693 {
 694         tTCPConnection  *conn = malloc( sizeof(tTCPConnection) );
 695
 696         conn->State = TCP_ST_CLOSED;
 697         conn->Interface = Interface;
 698         conn->LocalPort = -1;
 699         conn->RemotePort = -1;
 700         memset( &conn->RemoteIP, 0, sizeof(conn->RemoteIP) );
 701
 702         conn->Node.ImplPtr = conn;
 703         conn->Node.NumACLs = 1;
 704         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 705         conn->Node.Read = TCP_Client_Read;
 706         conn->Node.Write = TCP_Client_Write;
 707         conn->Node.IOCtl = TCP_Client_IOCtl;
 708         conn->Node.Close = TCP_Client_Close;
 709
 710         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 711
 712         LOCK(&glTCP_OutbountCons);
 713         conn->Next = gTCP_OutbountCons;
 714         gTCP_OutbountCons = conn;
 715         RELEASE(&glTCP_OutbountCons);
 716
 717         return &conn->Node;
 718 }
 719
 720 /**
 721  * \brief Wait for a packet and return it
 722  * \note If \a Length is smaller than the size of the packet, the rest
 723  *       of the packet's data will be discarded.
 724  */
 725 Uint64 TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 726 {
 727         tTCPConnection  *conn = Node->ImplPtr;
 728         char    *destbuf = Buffer;
 729         size_t  len;
 730
 731         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
 732         LOG("conn = %p", conn);
 733         LOG("conn->State = %i", conn->State);
 734
 735         // Check if connection is open
 736         while( conn->State == TCP_ST_HALFOPEN || conn->State == TCP_ST_SYN_SENT )
 737                 Threads_Yield();
 738         if( conn->State != TCP_ST_OPEN ) {
 739                 LEAVE('i', 0);
 740                 return 0;
 741         }
 742
 743         // Poll packets
 744         for(;;)
 745         {
 746                 // Lock list and check if there is a packet
 747                 LOCK( &conn->lRecievedPackets );
 748                 if( conn->RecievedBuffer->Length == 0 ) {
 749                         // If not, release the lock, yield and try again
 750                         RELEASE( &conn->lRecievedPackets );
 751                         Threads_Yield();
 752                         continue;
 753                 }
 754
 755                 // Attempt to read all `Length` bytes
 756                 len = RingBuffer_Read( destbuf, conn->RecievedBuffer, Length );
 757
 758                 // Release the lock (we don't need it any more)
 759                 RELEASE( &conn->lRecievedPackets );
 760
 761                 LEAVE('i', len);
 762                 return len;
 763         }
 764 }
 765
 766 /**
 767  * \brief Send a data packet on a connection
 768  */
 769 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, void *Data)
 770 {
 771         char    buf[sizeof(tTCPHeader)+Length];
 772         tTCPHeader      *packet = (void*)buf;
 773
 774         packet->SourcePort = htons(Connection->LocalPort);
 775         packet->DestPort = htons(Connection->RemotePort);
 776         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
 777         packet->WindowSize = TCP_WINDOW_SIZE;
 778
 779         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 780         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
 781         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
 782
 783         memcpy(packet->Options, Data, Length);
 784
 785         TCP_SendPacket( Connection, sizeof(tTCPHeader)+Length, packet );
 786
 787         Connection->NextSequenceSend += Length;
 788 }
 789
 790 /**
 791  * \brief Send some bytes on a connection
 792  */
 793 Uint64 TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 794 {
 795         tTCPConnection  *conn = Node->ImplPtr;
 796         size_t  rem = Length;
 797
 798         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
 799
 800         // Check if connection is open
 801         while( conn->State == TCP_ST_HALFOPEN || conn->State == TCP_ST_SYN_SENT )
 802                 Threads_Yield();
 803         if( conn->State != TCP_ST_OPEN ) {
 804                 LEAVE('i', 0);
 805                 return 0;
 806         }
 807
 808         while( rem > TCP_MAX_PACKET_SIZE )
 809         {
 810                 TCP_INT_SendDataPacket(conn, TCP_MAX_PACKET_SIZE, Buffer);
 811                 Buffer += TCP_MAX_PACKET_SIZE;
 812         }
 813
 814         TCP_INT_SendDataPacket(conn, rem, Buffer);
 815
 816         LEAVE('i', Length);
 817         return Length;
 818 }
 819
 820 /**
 821  * \brief Open a connection to another host using TCP
 822  * \param Conn  Connection structure
 823  */
 824 void TCP_StartConnection(tTCPConnection *Conn)
 825 {
 826         tTCPHeader      hdr;
 827
 828         Conn->State = TCP_ST_SYN_SENT;
 829
 830         hdr.SourcePort = htons(Conn->LocalPort);
 831         hdr.DestPort = htons(Conn->RemotePort);
 832         Conn->NextSequenceSend = rand();
 833         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
 834         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
 835         hdr.Flags = TCP_FLAG_SYN;
 836         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
 837         hdr.Checksum = 0;       // TODO
 838         hdr.UrgentPointer = 0;
 839
 840         TCP_SendPacket( Conn, sizeof(tTCPHeader), &hdr );
 841
 842         Conn->NextSequenceSend ++;
 843         Conn->State = TCP_ST_SYN_SENT;
 844         return ;
 845 }
 846
 847 /**
 848  * \brief Control a client socket
 849  */
 850 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
 851 {
 852         tTCPConnection  *conn = Node->ImplPtr;
 853
 854         switch(ID)
 855         {
 856         case 4: // Get/Set local port
 857                 if(!Data)
 858                         return conn->LocalPort;
 859                 if(conn->State != TCP_ST_CLOSED)
 860                         return -1;
 861                 if(!CheckMem(Data, sizeof(Uint16)))
 862                         return -1;
 863
 864                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
 865                         return -1;
 866
 867                 conn->LocalPort = *(Uint16*)Data;
 868                 return 0;
 869
 870         case 5: // Get/Set remote port
 871                 if(!Data)       return conn->RemotePort;
 872                 if(conn->State != TCP_ST_CLOSED)        return -1;
 873                 if(!CheckMem(Data, sizeof(Uint16)))     return -1;
 874                 conn->RemotePort = *(Uint16*)Data;
 875                 return 0;
 876
 877         case 6: // Set Remote IP
 878                 if( conn->State != TCP_ST_CLOSED )
 879                         return -1;
 880                 if( conn->Interface->Type == 4 )
 881                 {
 882                         if(!CheckMem(Data, sizeof(tIPv4)))      return -1;
 883                         conn->RemoteIP.v4 = *(tIPv4*)Data;
 884                 }
 885                 else if( conn->Interface->Type == 6 )
 886                 {
 887                         if(!CheckMem(Data, sizeof(tIPv6)))      return -1;
 888                         conn->RemoteIP.v6 = *(tIPv6*)Data;
 889                 }
 890                 return 0;
 891
 892         case 7: // Connect
 893                 if(conn->LocalPort == 0xFFFF)
 894                         conn->LocalPort = TCP_GetUnusedPort();
 895                 if(conn->RemotePort == -1)
 896                         return 0;
 897
 898                 TCP_StartConnection(conn);
 899                 return 1;
 900         }
 901
 902         return 0;
 903 }
 904
 905 void TCP_Client_Close(tVFS_Node *Node)
 906 {
 907         tTCPConnection  *conn = Node->ImplPtr;
 908         tTCPHeader      packet;
 909
 910         packet.SourcePort = htons(conn->LocalPort);
 911         packet.DestPort = htons(conn->RemotePort);
 912         packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
 913         packet.WindowSize = TCP_WINDOW_SIZE;
 914
 915         packet.AcknowlegementNumber = 0;
 916         packet.SequenceNumber = htonl(conn->NextSequenceSend);
 917         packet.Flags = TCP_FLAG_FIN;
 918
 919         conn->State = TCP_ST_FIN_SENT;
 920
 921         TCP_SendPacket( conn, sizeof(tTCPHeader), &packet );
 922
 923         while( conn->State == TCP_ST_FIN_SENT ) Threads_Yield();
 924
 925         free(conn);
 926 }