KernelLand/Modules/IPStack/tcp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - TCP Handling
   4  */
   5 #define DEBUG   0
   6 #include "ipstack.h"
   7 #include "ipv4.h"
   8 #include "ipv6.h"
   9 #include "tcp.h"
  10
  11 #define HEXDUMP_INCOMING        0
  12 #define HEXDUMP_OUTGOING        0
  13
  14 #define TCP_MIN_DYNPORT 0xC000
  15 #define TCP_MAX_HALFOPEN        1024    // Should be enough
  16
  17 #define TCP_MAX_PACKET_SIZE     1024
  18 #define TCP_WINDOW_SIZE 0x2000
  19 #define TCP_RECIEVE_BUFFER_SIZE 0x8000
  20 #define TCP_DACK_THRESHOLD      4096
  21 #define TCP_DACK_TIMEOUT        500
  22
  23 #define TCP_DEBUG       0       // Set to non-0 to enable TCP packet logging
  24
  25 // === PROTOTYPES ===
  26 void    TCP_Initialise(void);
  27 void    TCP_StartConnection(tTCPConnection *Conn);
  28 void    TCP_SendPacket(tTCPConnection *Conn, tTCPHeader *Header, size_t DataLen, const void *Data);
  29 void    TCP_int_SendPacket(tInterface *Interface, const void *Dest, tTCPHeader *Header, size_t Length, const void *Data);
  30 void    TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  31 void    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
  32 int     TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length);
  33 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
  34 void    TCP_int_SendDelayedACK(void *ConnPtr);
  35 void    TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason);
  36 Uint16  TCP_GetUnusedPort();
  37  int    TCP_AllocatePort(Uint16 Port);
  38  int    TCP_DeallocatePort(Uint16 Port);
  39 tTCPConnection  *TCP_int_CreateConnection(tInterface *Interface, enum eTCPConnectionState State);
  40 // --- Server
  41 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
  42  int    TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Name[FILENAME_MAX]);
  43 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags);
  44  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
  45 void    TCP_Server_Close(tVFS_Node *Node);
  46 // --- Client
  47 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
  48 size_t  TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
  49 size_t  TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags);
  50  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
  51 void    TCP_Client_Close(tVFS_Node *Node);
  52 // --- Helpers
  53  int    WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
  54
  55 // === TEMPLATES ===
  56 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
  57 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
  58 tVFS_NodeType   gTCP_ServerNodeType = {
  59         .TypeName = "TCP Server",
  60         .ReadDir = TCP_Server_ReadDir,
  61         .FindDir = TCP_Server_FindDir,
  62         .IOCtl   = TCP_Server_IOCtl,
  63         .Close   = TCP_Server_Close
  64         };
  65 tVFS_NodeType   gTCP_ClientNodeType = {
  66         .TypeName = "TCP Client/Connection",
  67         .Read  = TCP_Client_Read,
  68         .Write = TCP_Client_Write,
  69         .IOCtl = TCP_Client_IOCtl,
  70         .Close = TCP_Client_Close
  71         };
  72
  73 // === GLOBALS ===
  74  int    giTCP_NumHalfopen = 0;
  75 tShortSpinlock  glTCP_Listeners;
  76 tTCPListener    *gTCP_Listeners;
  77 tShortSpinlock  glTCP_OutbountCons;
  78 tTCPConnection  *gTCP_OutbountCons;
  79 Uint32  gaTCP_PortBitmap[0x800];
  80  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  81
  82 // === CODE ===
  83 /**
  84  * \brief Initialise the TCP Layer
  85  *
  86  * Registers the client and server files and the GetPacket callback
  87  */
  88 void TCP_Initialise(void)
  89 {
  90         giTCP_NextOutPort += rand()%128;
  91         IPStack_AddFile(&gTCP_ServerFile);
  92         IPStack_AddFile(&gTCP_ClientFile);
  93         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  94         IPv6_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
  95 }
  96
  97 /**
  98  * \brief Sends a packet from the specified connection, calculating the checksums
  99  * \param Conn  Connection
 100  * \param Length        Length of data
 101  * \param Data  Packet data (cast as a TCP Header)
 102  */
 103 void TCP_SendPacket( tTCPConnection *Conn, tTCPHeader *Header, size_t Length, const void *Data )
 104 {
 105         TCP_int_SendPacket(Conn->Interface, &Conn->RemoteIP, Header, Length, Data);
 106 }
 107
 108 void TCP_int_SendPacket(tInterface *Interface, const void *Dest, tTCPHeader *Header, size_t Length, const void *Data )
 109 {
 110         tIPStackBuffer  *buffer;
 111         Uint16  checksum[3];
 112          int    packlen = sizeof(*Header) + Length;
 113
 114         buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
 115         if( Data && Length )
 116                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
 117         IPStack_Buffer_AppendSubBuffer(buffer, sizeof(*Header), 0, Header, NULL, NULL);
 118
 119         LOG("Sending %i+%i to %s:%i", sizeof(*Header), Length,
 120                 IPStack_PrintAddress(Interface->Type, Dest),
 121                 ntohs(Header->RemotePort)
 122                 );
 123
 124         Header->Checksum = 0;
 125         checksum[1] = htons( ~IPv4_Checksum(Header, sizeof(tTCPHeader)) );
 126         checksum[2] = htons( ~IPv4_Checksum(Data, Length) );
 127
 128         // TODO: Fragment packet
 129
 130         switch( Interface->Type )
 131         {
 132         case 4:
 133                 // Get IPv4 pseudo-header checksum
 134                 {
 135                         Uint32  buf[3];
 136                         buf[0] = ((tIPv4*)Interface->Address)->L;
 137                         buf[1] = ((tIPv4*)Dest)->L;
 138                         buf[2] = htonl( (packlen) | (IP4PROT_TCP<<16) | (0<<24) );
 139                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 140                 }
 141                 // - Combine checksums
 142                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );
 143                 IPv4_SendPacket(Interface, *(tIPv4*)Dest, IP4PROT_TCP, 0, buffer);
 144                 break;
 145
 146         case 6:
 147                 // Append IPv6 Pseudo Header
 148                 {
 149                         Uint32  buf[4+4+1+1];
 150                         memcpy(buf, Interface->Address, 16);
 151                         memcpy(&buf[4], Dest, 16);
 152                         buf[8] = htonl(packlen);
 153                         buf[9] = htonl(IP4PROT_TCP);
 154                         checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
 155                 }
 156                 Header->Checksum = htons( IPv4_Checksum(checksum, sizeof(checksum)) );  // Combine the two
 157                 IPv6_SendPacket(Interface, *(tIPv6*)Dest, IP4PROT_TCP, buffer);
 158                 break;
 159         }
 160 }
 161
 162 void TCP_int_SendRSTTo(tInterface *Interface, void *Address, size_t Length, const tTCPHeader *Header)
 163 {
 164         tTCPHeader      out_hdr = {0};
 165
 166         out_hdr.DataOffset = (sizeof(out_hdr)/4) << 4;
 167         out_hdr.DestPort = Header->SourcePort;
 168         out_hdr.SourcePort = Header->DestPort;
 169
 170         size_t  data_len = Length - (Header->DataOffset>>4)*4;
 171         out_hdr.AcknowlegementNumber = htonl( ntohl(Header->SequenceNumber) + data_len );
 172         if( Header->Flags & TCP_FLAG_ACK ) {
 173                 out_hdr.Flags = TCP_FLAG_RST;
 174                 out_hdr.SequenceNumber = Header->AcknowlegementNumber;
 175         }
 176         else {
 177                 out_hdr.Flags = TCP_FLAG_RST|TCP_FLAG_ACK;
 178                 out_hdr.SequenceNumber = 0;
 179         }
 180         TCP_int_SendPacket(Interface, Address, &out_hdr, 0, NULL);
 181 }
 182
 183 /**
 184  * \brief Handles a packet from the IP Layer
 185  * \param Interface     Interface the packet arrived from
 186  * \param Address       Pointer to the addres structure
 187  * \param Length        Size of packet in bytes
 188  * \param Buffer        Packet data
 189  */
 190 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 191 {
 192         tTCPHeader      *hdr = Buffer;
 193
 194         #if TCP_DEBUG
 195         Log_Log("TCP", "TCP_GetPacket: <Local>:%i from [%s]:%i, Flags = %s%s%s%s%s%s%s%s",
 196                 ntohs(hdr->DestPort),
 197                 IPStack_PrintAddress(Interface->Type, Address),
 198                 ntohs(hdr->SourcePort),
 199                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
 200                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
 201                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
 202                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
 203                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
 204                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
 205                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
 206                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
 207                 );
 208         #endif
 209
 210         if( Length > (hdr->DataOffset >> 4)*4 )
 211         {
 212                 LOG("SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 213 #if HEXDUMP_INCOMING
 214                 Debug_HexDump(
 215                         "TCP_GetPacket: Packet Data = ",
 216                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
 217                         Length - (hdr->DataOffset >> 4)*4
 218                         );
 219 #endif
 220         }
 221
 222         // Check Servers
 223         for( tTCPListener *srv = gTCP_Listeners; srv; srv = srv->Next )
 224         {
 225                 // Check if the server is active
 226                 if(srv->Port == 0)      continue;
 227                 // Check the interface
 228                 if(srv->Interface && srv->Interface != Interface)       continue;
 229                 // Check the destination port
 230                 if(srv->Port != htons(hdr->DestPort))   continue;
 231
 232                 Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 233                 // Is this in an established connection?
 234                 for( tTCPConnection *conn = srv->Connections; conn; conn = conn->Next )
 235                 {
 236                         // Check that it is coming in on the same interface
 237                         if(conn->Interface != Interface)        continue;
 238
 239                         // Check Source Port
 240                         Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 241                                 conn->RemotePort, ntohs(hdr->SourcePort));
 242                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 243
 244                         // Check Source IP
 245                         Log_Debug("TCP", "TCP_GetPacket: conn->RemoteIP(%s)",
 246                                 IPStack_PrintAddress(conn->Interface->Type, &conn->RemoteIP));
 247                         Log_Debug("TCP", "                == Address(%s)",
 248                                 IPStack_PrintAddress(conn->Interface->Type, Address));
 249                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
 250                                 continue ;
 251
 252                         Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 253                         // We have a response!
 254                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 255
 256                         return;
 257                 }
 258
 259
 260                 if( hdr->Flags & TCP_FLAG_RST ) {
 261                         LOG("RST, ignore");
 262                         return ;
 263                 }
 264                 else if( hdr->Flags & TCP_FLAG_ACK ) {
 265                         LOG("ACK, send RST");
 266                         TCP_int_SendRSTTo(Interface, Address, Length, hdr);
 267                         return ;
 268                 }
 269                 else if( !(hdr->Flags & TCP_FLAG_SYN) ) {
 270                         LOG("Other, ignore");
 271                         return ;
 272                 }
 273                 Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 274
 275                 // TODO: Check for halfopen max
 276
 277                 tTCPConnection *conn = TCP_int_CreateConnection(Interface, TCP_ST_SYN_RCVD);
 278                 conn->LocalPort = srv->Port;
 279                 conn->RemotePort = ntohs(hdr->SourcePort);
 280
 281                 switch(Interface->Type)
 282                 {
 283                 case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
 284                 case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
 285                 default:        ASSERTC(Interface->Type,==,4);  return;
 286                 }
 287
 288                 conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 289                 conn->HighestSequenceRcvd = conn->NextSequenceRcv;
 290                 conn->NextSequenceSend = rand();
 291
 292                 conn->Node.ImplInt = srv->NextID ++;
 293
 294                 // Hmm... Theoretically, this lock will never have to wait,
 295                 // as the interface is locked to the watching thread, and this
 296                 // runs in the watching thread. But, it's a good idea to have
 297                 // it, just in case
 298                 // Oh, wait, there is a case where a wildcard can be used
 299                 // (srv->Interface == NULL) so having the lock is a good idea
 300                 SHORTLOCK(&srv->lConnections);
 301                 if( !srv->Connections )
 302                         srv->Connections = conn;
 303                 else
 304                         srv->ConnectionsTail->Next = conn;
 305                 srv->ConnectionsTail = conn;
 306                 if(!srv->NewConnections)
 307                         srv->NewConnections = conn;
 308                 VFS_MarkAvaliable( &srv->Node, 1 );
 309                 SHORTREL(&srv->lConnections);
 310                 Semaphore_Signal(&srv->WaitingConnections, 1);
 311
 312                 // Send the SYN ACK
 313                 hdr->Flags |= TCP_FLAG_ACK;
 314                 hdr->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
 315                 hdr->SequenceNumber = htonl(conn->NextSequenceSend);
 316                 hdr->DestPort = hdr->SourcePort;
 317                 hdr->SourcePort = htons(srv->Port);
 318                 hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 319                 TCP_SendPacket( conn, hdr, 0, NULL );
 320                 conn->NextSequenceSend ++;
 321                 return ;
 322         }
 323
 324         // Check Open Connections
 325         {
 326                 for( tTCPConnection *conn = gTCP_OutbountCons; conn; conn = conn->Next )
 327                 {
 328                         // Check that it is coming in on the same interface
 329                         if(conn->Interface != Interface)        continue;
 330
 331                         // Check Source Port
 332                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
 333
 334                         // Check Source IP
 335                         if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
 336                                 continue;
 337                         if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 338                                 continue;
 339
 340                         TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 341                         return ;
 342                 }
 343         }
 344
 345         Log_Log("TCP", "TCP_GetPacket: No Match");
 346         // If not a RST, send a RST
 347         if( !(hdr->Flags & TCP_FLAG_RST) )
 348         {
 349                 TCP_int_SendRSTTo(Interface, Address, Length, hdr);
 350         }
 351 }
 352
 353 /**
 354  * \brief Handles a packet sent to a specific connection
 355  * \param Connection    TCP Connection pointer
 356  * \param Header        TCP Packet pointer
 357  * \param Length        Length of the packet
 358  */
 359 void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
 360 {
 361          int    dataLen;
 362         Uint32  sequence_num;
 363
 364         // Silently drop once finished
 365         // TODO: Check if this needs to be here
 366         if( Connection->State == TCP_ST_FINISHED ) {
 367                 Log_Log("TCP", "Packet ignored - connection finnished");
 368                 return ;
 369         }
 370
 371         // Syncronise sequence values
 372         if(Header->Flags & TCP_FLAG_SYN) {
 373                 // TODO: What if the packet also has data?
 374                 if( Connection->LastACKSequence != Connection->NextSequenceRcv )
 375                         TCP_INT_SendACK(Connection, "SYN");
 376                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
 377                 // TODO: Process HighestSequenceRcvd
 378                 // HACK!
 379                 if( Connection->HighestSequenceRcvd == 0 )
 380                         Connection->HighestSequenceRcvd = Connection->NextSequenceRcv;
 381                 Connection->LastACKSequence = Connection->NextSequenceRcv;
 382         }
 383
 384         // Ackowledge a sent packet
 385         if(Header->Flags & TCP_FLAG_ACK) {
 386                 // TODO: Process an ACKed Packet
 387                 LOG("Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 388         }
 389
 390         // Get length of data
 391         dataLen = Length - (Header->DataOffset>>4)*4;
 392         LOG("dataLen = %i", dataLen);
 393         #if TCP_DEBUG
 394         Log_Debug("TCP", "State %i, dataLen = %x", Connection->State, dataLen);
 395         #endif
 396
 397         //
 398         // State Machine
 399         //
 400         switch( Connection->State )
 401         {
 402         // Pre-init connection?
 403         case TCP_ST_CLOSED:
 404                 Log_Log("TCP", "Packets to a closed connection?!");
 405                 break;
 406
 407         // --- Init States ---
 408         // SYN sent, expecting SYN-ACK Connection Opening
 409         case TCP_ST_SYN_SENT:
 410                 if( Header->Flags & TCP_FLAG_SYN )
 411                 {
 412                         if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
 413                                 Connection->HighestSequenceRcvd ++;
 414                         Connection->NextSequenceRcv ++;
 415
 416                         if( Header->Flags & TCP_FLAG_ACK )
 417                         {
 418                                 Log_Log("TCP", "ACKing SYN-ACK");
 419                                 Connection->State = TCP_ST_OPEN;
 420                                 VFS_MarkFull(&Connection->Node, 0);
 421                         }
 422                         else
 423                         {
 424                                 Log_Log("TCP", "ACKing SYN");
 425                                 Connection->State = TCP_ST_SYN_RCVD;
 426                         }
 427                         Header->DestPort = Header->SourcePort;
 428                         Header->SourcePort = htons(Connection->LocalPort);
 429                         Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 430                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 431                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 432                         Header->Flags = TCP_FLAG_ACK;
 433                         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 434                         TCP_SendPacket( Connection, Header, 0, NULL );
 435                 }
 436                 break;
 437
 438         // SYN-ACK sent, expecting ACK
 439         case TCP_ST_SYN_RCVD:
 440                 if( Header->Flags & TCP_FLAG_ACK )
 441                 {
 442                         // TODO: Handle max half-open limit
 443                         Log_Log("TCP", "Connection fully opened");
 444                         Connection->State = TCP_ST_OPEN;
 445                         VFS_MarkFull(&Connection->Node, 0);
 446                 }
 447                 break;
 448
 449         // --- Established State ---
 450         case TCP_ST_OPEN:
 451                 // - Handle State changes
 452                 //
 453                 if( Header->Flags & TCP_FLAG_FIN ) {
 454                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
 455                         VFS_MarkError(&Connection->Node, 1);
 456                         Connection->State = TCP_ST_CLOSE_WAIT;
 457 //                      Header->Flags &= ~TCP_FLAG_FIN;
 458                         // CLOSE WAIT requires the client to close (or does it?)
 459                         #if 0
 460
 461                         #endif
 462                 }
 463
 464                 // Check for an empty packet
 465                 if(dataLen == 0) {
 466                         if( Header->Flags == TCP_FLAG_ACK )
 467                         {
 468                                 Log_Log("TCP", "ACK only packet");
 469                                 return ;
 470                         }
 471                         // TODO: Is this right? (empty packet counts as one byte)
 472                         if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
 473                                 Connection->HighestSequenceRcvd ++;
 474                         Connection->NextSequenceRcv ++;
 475                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
 476                         TCP_INT_SendACK(Connection, "Empty");
 477                         return ;
 478                 }
 479
 480                 // NOTES:
 481                 // Flags
 482                 //    PSH - Has Data?
 483                 // /NOTES
 484
 485                 sequence_num = ntohl(Header->SequenceNumber);
 486
 487                 LOG("0x%08x <= 0x%08x < 0x%08x",
 488                         Connection->NextSequenceRcv,
 489                         ntohl(Header->SequenceNumber),
 490                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
 491                         );
 492
 493                 // Is this packet the next expected packet?
 494                 if( sequence_num == Connection->NextSequenceRcv )
 495                 {
 496                          int    rv;
 497                         // Ooh, Goodie! Add it to the recieved list
 498                         rv = TCP_INT_AppendRecieved(Connection,
 499                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
 500                                 dataLen
 501                                 );
 502                         if(rv != 0) {
 503                                 Log_Notice("TCP", "TCP_INT_AppendRecieved rv %i", rv);
 504                                 break;
 505                         }
 506                         LOG("0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 507                         if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
 508                                 Connection->HighestSequenceRcvd += dataLen;
 509                         Connection->NextSequenceRcv += dataLen;
 510
 511                         // TODO: This should be moved out of the watcher thread,
 512                         // so that a single lost packet on one connection doesn't cause
 513                         // all connections on the interface to lag.
 514                         // - Meh, no real issue, as the cache shouldn't be that large
 515                         TCP_INT_UpdateRecievedFromFuture(Connection);
 516
 517                         #if 1
 518                         // - Only send an ACK if we've had a burst
 519                         if( Connection->NextSequenceRcv > (Uint32)(TCP_DACK_THRESHOLD + Connection->LastACKSequence) )
 520                         {
 521                                 TCP_INT_SendACK(Connection, "DACK Burst");
 522                                 // - Extend TCP deferred ACK timer
 523                                 Time_RemoveTimer(Connection->DeferredACKTimer);
 524                         }
 525                         // - Schedule the deferred ACK timer (if already scheduled, this is a NOP)
 526                         Time_ScheduleTimer(Connection->DeferredACKTimer, TCP_DACK_TIMEOUT);
 527                         #else
 528                         TCP_INT_SendACK(Connection, "RX");
 529                         #endif
 530                 }
 531                 // Check if the packet is in window
 532                 else if( WrapBetween(Connection->NextSequenceRcv, sequence_num,
 533                                 Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
 534                 {
 535                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
 536                         #if CACHE_FUTURE_PACKETS_IN_BYTES
 537                         Uint32  index;
 538
 539                         index = sequence_num % TCP_WINDOW_SIZE;
 540                         for( int i = 0; i < dataLen; i ++ )
 541                         {
 542                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
 543                                 Connection->FuturePacketData[index] = dataptr[i];
 544                                 // Do a wrap increment
 545                                 index ++;
 546                                 if(index == TCP_WINDOW_SIZE)    index = 0;
 547                         }
 548                         #else
 549                         tTCPStoredPacket        *pkt, *tmp, *prev = NULL;
 550
 551                         // Allocate and fill cached packet
 552                         pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
 553                         pkt->Next = NULL;
 554                         pkt->Sequence = ntohl(Header->SequenceNumber);
 555                         pkt->Length = dataLen;
 556                         memcpy(pkt->Data, dataptr, dataLen);
 557
 558                         Log_Log("TCP", "We missed a packet, caching",
 559                                 pkt->Sequence, Connection->NextSequenceRcv);
 560
 561                         // No? Well, let's cache it and look at it later
 562                         SHORTLOCK( &Connection->lFuturePackets );
 563                         for(tmp = Connection->FuturePackets;
 564                                 tmp;
 565                                 prev = tmp, tmp = tmp->Next)
 566                         {
 567                                 if(tmp->Sequence >= pkt->Sequence)      break;
 568                         }
 569
 570                         // Add if before first, or sequences don't match
 571                         if( !tmp || tmp->Sequence != pkt->Sequence )
 572                         {
 573                                 if(prev)
 574                                         prev->Next = pkt;
 575                                 else
 576                                         Connection->FuturePackets = pkt;
 577                                 pkt->Next = tmp;
 578                         }
 579                         // Replace if larger
 580                         else if(pkt->Length > tmp->Length)
 581                         {
 582                                 if(prev)
 583                                         prev->Next = pkt;
 584                                 pkt->Next = tmp->Next;
 585                                 free(tmp);
 586                         }
 587                         else
 588                         {
 589                                 free(pkt);      // TODO: Find some way to remove this
 590                         }
 591                         SHORTREL( &Connection->lFuturePackets );
 592                         #endif
 593                 }
 594                 // Badly out of sequence packet
 595                 else
 596                 {
 597                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
 598                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
 599                         // Spec says we should send an empty ACK with the current state
 600                         TCP_INT_SendACK(Connection, "Bad Seq");
 601                 }
 602                 break;
 603
 604         // --- Remote close states
 605         case TCP_ST_CLOSE_WAIT:
 606
 607                 // Ignore everything, CLOSE_WAIT is terminated by the client
 608                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
 609
 610                 break;
 611
 612         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
 613         case TCP_ST_LAST_ACK:
 614                 if( Header->Flags & TCP_FLAG_ACK )
 615                 {
 616                         Connection->State = TCP_ST_FINISHED;    // Connection completed
 617                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
 618                         // TODO: Destrory the TCB
 619                 }
 620                 break;
 621
 622         // --- Local close States
 623         case TCP_ST_FIN_WAIT1:
 624                 if( Header->Flags & TCP_FLAG_FIN )
 625                 {
 626                         Connection->State = TCP_ST_CLOSING;
 627                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
 628                         VFS_MarkError(&Connection->Node, 1);
 629
 630                         // ACK Packet
 631                         Header->DestPort = Header->SourcePort;
 632                         Header->SourcePort = htons(Connection->LocalPort);
 633                         Header->AcknowlegementNumber = Header->SequenceNumber;
 634                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 635                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 636                         Header->Flags = TCP_FLAG_ACK;
 637                         TCP_SendPacket( Connection, Header, 0, NULL );
 638                         break ;
 639                 }
 640
 641                 // TODO: Make sure that the packet is actually ACKing the FIN
 642                 if( Header->Flags & TCP_FLAG_ACK )
 643                 {
 644                         Connection->State = TCP_ST_FIN_WAIT2;
 645                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
 646                         VFS_MarkError(&Connection->Node, 1);
 647                         return ;
 648                 }
 649                 break;
 650
 651         case TCP_ST_FIN_WAIT2:
 652                 if( Header->Flags & TCP_FLAG_FIN )
 653                 {
 654                         Connection->State = TCP_ST_TIME_WAIT;
 655                         Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
 656                         // Send ACK
 657                         Header->DestPort = Header->SourcePort;
 658                         Header->SourcePort = htons(Connection->LocalPort);
 659                         Header->AcknowlegementNumber = Header->SequenceNumber;
 660                         Header->SequenceNumber = htonl(Connection->NextSequenceSend);
 661                         Header->WindowSize = htons(TCP_WINDOW_SIZE);
 662                         Header->Flags = TCP_FLAG_ACK;
 663                         TCP_SendPacket( Connection, Header, 0, NULL );
 664                 }
 665                 break;
 666
 667         case TCP_ST_CLOSING:
 668                 // TODO: Make sure that the packet is actually ACKing the FIN
 669                 if( Header->Flags & TCP_FLAG_ACK )
 670                 {
 671                         Connection->State = TCP_ST_TIME_WAIT;
 672                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
 673                         VFS_MarkError(&Connection->Node, 1);
 674                         return ;
 675                 }
 676                 break;
 677
 678         // --- Closed (or near closed) states) ---
 679         case TCP_ST_TIME_WAIT:
 680                 Log_Log("TCP", "Packets on Time-Wait, ignored");
 681                 break;
 682
 683         case TCP_ST_FINISHED:
 684                 Log_Log("TCP", "Packets when CLOSED, ignoring");
 685                 break;
 686
 687         //default:
 688         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
 689         //      break;
 690         }
 691
 692 }
 693
 694 /**
 695  * \brief Appends a packet to the recieved list
 696  * \param Connection    Connection structure
 697  * \param Data  Packet contents
 698  * \param Length        Length of \a Data
 699  */
 700 int TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
 701 {
 702         Mutex_Acquire( &Connection->lRecievedPackets );
 703
 704         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
 705         {
 706                 VFS_MarkAvaliable(&Connection->Node, 1);
 707                 Log_Error("TCP", "Buffer filled, packet dropped (:%i) - %i + %i > %i",
 708                         Connection->LocalPort, Connection->RecievedBuffer->Length, Length,
 709                         Connection->RecievedBuffer->Space
 710                         );
 711                 Mutex_Release( &Connection->lRecievedPackets );
 712                 return 1;
 713         }
 714
 715         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
 716
 717         VFS_MarkAvaliable(&Connection->Node, 1);
 718
 719         Mutex_Release( &Connection->lRecievedPackets );
 720         return 0;
 721 }
 722
 723 /**
 724  * \brief Updates the connections recieved list from the future list
 725  * \param Connection    Connection structure
 726  *
 727  * Updates the recieved packets list with packets from the future (out
 728  * of order) packets list that are now able to be added in direct
 729  * sequence.
 730  */
 731 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 732 {
 733         #if CACHE_FUTURE_PACKETS_IN_BYTES
 734         // Calculate length of contiguous bytes
 735          int    length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
 736         Uint32  index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 737         LOG("length=%i, index=%i", length, index);
 738         for( int i = 0; i < length; i ++ )
 739         {
 740                  int    bit = index % 8;
 741                 Uint8   bitfield_byte = Connection->FuturePacketValidBytes[index / 8];
 742                 if( (bitfield_byte & (1 << bit)) == 0 ) {
 743                         length = i;
 744                         break;
 745                 }
 746
 747                 if( bitfield_byte == 0xFF ) {
 748                          int    inc = 8 - bit;
 749                         i += inc - 1;
 750                         index += inc;
 751                 }
 752                 else {
 753                         index ++;
 754                 }
 755                 if(index > TCP_WINDOW_SIZE)
 756                         index -= TCP_WINDOW_SIZE;
 757         }
 758
 759         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
 760
 761         // Write data to to the ring buffer
 762         if( TCP_WINDOW_SIZE - index > length )
 763         {
 764                 // Simple case
 765                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, length );
 766         }
 767         else
 768         {
 769                  int    endLen = TCP_WINDOW_SIZE - index;
 770                 // 2-part case
 771                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
 772                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - length );
 773         }
 774
 775         // Mark (now saved) bytes as invalid
 776         // - Align index
 777         while(index % 8 && length > 0)
 778         {
 779                 Connection->FuturePacketData[index] = 0;
 780                 Connection->FuturePacketValidBytes[index/8] &= ~(1 << (index%8));
 781                 index ++;
 782                 if(index > TCP_WINDOW_SIZE)
 783                         index -= TCP_WINDOW_SIZE;
 784                 length --;
 785         }
 786         while( length > 7 )
 787         {
 788                 Connection->FuturePacketData[index] = 0;
 789                 Connection->FuturePacketValidBytes[index/8] = 0;
 790                 length -= 8;
 791                 index += 8;
 792                 if(index > TCP_WINDOW_SIZE)
 793                         index -= TCP_WINDOW_SIZE;
 794         }
 795         while(length)
 796         {
 797                 Connection->FuturePacketData[index] = 0;
 798                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
 799                 index ++;
 800                 if(index > TCP_WINDOW_SIZE)
 801                         index -= TCP_WINDOW_SIZE;
 802                 length --;
 803         }
 804
 805         #else
 806         tTCPStoredPacket        *pkt;
 807         for(;;)
 808         {
 809                 SHORTLOCK( &Connection->lFuturePackets );
 810
 811                 // Clear out duplicates from cache
 812                 // - If a packet has just been recieved, and it is expected, then
 813                 //   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
 814                 //   packets in cache that are smaller than the next expected
 815                 //   are now defunct.
 816                 pkt = Connection->FuturePackets;
 817                 while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
 818                 {
 819                         tTCPStoredPacket        *next = pkt->Next;
 820                         free(pkt);
 821                         pkt = next;
 822                 }
 823
 824                 // If there's no packets left in cache, stop looking
 825                 if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
 826                         SHORTREL( &Connection->lFuturePackets );
 827                         return;
 828                 }
 829
 830                 // Delete packet from future list
 831                 Connection->FuturePackets = pkt->Next;
 832
 833                 // Release list
 834                 SHORTREL( &Connection->lFuturePackets );
 835
 836                 // Looks like we found one
 837                 TCP_INT_AppendRecieved(Connection, pkt->Data, pkt->Length);
 838                 if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
 839                         Connection->HighestSequenceRcvd += pkt->Length;
 840                 Connection->NextSequenceRcv += pkt->Length;
 841                 free(pkt);
 842         }
 843         #endif
 844 }
 845
 846 void TCP_int_SendDelayedACK(void *ConnPtr)
 847 {
 848         TCP_INT_SendACK(ConnPtr, "DACK Timeout");
 849 }
 850
 851 void TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason)
 852 {
 853         tTCPHeader      hdr;
 854         // ACK Packet
 855         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
 856         hdr.DestPort = htons(Connection->RemotePort);
 857         hdr.SourcePort = htons(Connection->LocalPort);
 858         hdr.AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
 859         hdr.SequenceNumber = htonl(Connection->NextSequenceSend);
 860         hdr.WindowSize = htons(TCP_WINDOW_SIZE);
 861         hdr.Flags = TCP_FLAG_ACK;       // TODO: Determine if SYN is wanted too
 862         hdr.Checksum = 0;       // TODO: Checksum
 863         hdr.UrgentPointer = 0;
 864         Log_Debug("TCP", "Sending ACK for 0x%08x (%s)", Connection->NextSequenceRcv, Reason);
 865         TCP_SendPacket( Connection, &hdr, 0, NULL );
 866         //Connection->NextSequenceSend ++;
 867         Connection->LastACKSequence = Connection->NextSequenceRcv;
 868 }
 869
 870 /**
 871  * \fn Uint16 TCP_GetUnusedPort()
 872  * \brief Gets an unused port and allocates it
 873  */
 874 Uint16 TCP_GetUnusedPort()
 875 {
 876         Uint16  ret;
 877
 878         // Get Next outbound port
 879         ret = giTCP_NextOutPort++;
 880         while( gaTCP_PortBitmap[ret/32] & (1UL << (ret%32)) )
 881         {
 882                 ret ++;
 883                 giTCP_NextOutPort++;
 884                 if(giTCP_NextOutPort == 0x10000) {
 885                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 886                 }
 887         }
 888
 889         // Mark the new port as used
 890         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 891
 892         return ret;
 893 }
 894
 895 /**
 896  * \fn int TCP_AllocatePort(Uint16 Port)
 897  * \brief Marks a port as used
 898  */
 899 int TCP_AllocatePort(Uint16 Port)
 900 {
 901         // Check if the port has already been allocated
 902         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 903                 return 0;
 904
 905         // Allocate
 906         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 907
 908         return 1;
 909 }
 910
 911 /**
 912  * \fn int TCP_DeallocatePort(Uint16 Port)
 913  * \brief Marks a port as unused
 914  */
 915 int TCP_DeallocatePort(Uint16 Port)
 916 {
 917         // Check if the port has already been allocated
 918         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 919                 return 0;
 920
 921         // Allocate
 922         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 923
 924         return 1;
 925 }
 926
 927 tTCPConnection *TCP_int_CreateConnection(tInterface *Interface, enum eTCPConnectionState State)
 928 {
 929         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
 930
 931         conn->State = State;
 932         conn->Interface = Interface;
 933         conn->LocalPort = -1;
 934         conn->RemotePort = -1;
 935
 936         conn->Node.ReferenceCount = 1;
 937         conn->Node.ImplPtr = conn;
 938         conn->Node.NumACLs = 1;
 939         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
 940         conn->Node.Type = &gTCP_ClientNodeType;
 941         conn->Node.BufferFull = 1;      // Cleared when connection opens
 942
 943         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
 944         #if 0
 945         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
 946         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
 947         #endif
 948
 949         #if CACHE_FUTURE_PACKETS_IN_BYTES
 950         // Future recieved data (ahead of the expected sequence number)
 951         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
 952         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
 953         #endif
 954
 955         conn->DeferredACKTimer = Time_AllocateTimer( TCP_int_SendDelayedACK, conn);
 956         return conn;
 957 }
 958
 959 // --- Server
 960 tVFS_Node *TCP_Server_Init(tInterface *Interface)
 961 {
 962         tTCPListener    *srv;
 963
 964         srv = calloc( 1, sizeof(tTCPListener) );
 965
 966         if( srv == NULL ) {
 967                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 968                 return NULL;
 969         }
 970
 971         srv->Interface = Interface;
 972         srv->Port = 0;
 973         srv->NextID = 0;
 974         srv->Connections = NULL;
 975         srv->ConnectionsTail = NULL;
 976         srv->NewConnections = NULL;
 977         srv->Next = NULL;
 978         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 979         srv->Node.Size = -1;
 980         srv->Node.ImplPtr = srv;
 981         srv->Node.NumACLs = 1;
 982         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
 983         srv->Node.Type = &gTCP_ServerNodeType;
 984
 985         SHORTLOCK(&glTCP_Listeners);
 986         srv->Next = gTCP_Listeners;
 987         gTCP_Listeners = srv;
 988         SHORTREL(&glTCP_Listeners);
 989
 990         return &srv->Node;
 991 }
 992
 993 /**
 994  * \brief Wait for a new connection and return the connection ID
 995  * \note Blocks until a new connection is made
 996  * \param Node  Server node
 997  * \param Pos   Position (ignored)
 998  */
 999 int TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Dest[FILENAME_MAX])
1000 {
1001         tTCPListener    *srv = Node->ImplPtr;
1002         tTCPConnection  *conn;
1003
1004         ENTER("pNode iPos", Node, Pos);
1005
1006         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
1007         Semaphore_Wait( &srv->WaitingConnections, 1 );
1008
1009         SHORTLOCK(&srv->lConnections);
1010         // Increment the new list (the current connection is still on the
1011         // normal list)
1012         conn = srv->NewConnections;
1013         srv->NewConnections = conn->Next;
1014
1015         if( srv->NewConnections == NULL )
1016                 VFS_MarkAvaliable( Node, 0 );
1017
1018         SHORTREL( &srv->lConnections );
1019
1020         LOG("conn = %p", conn);
1021         LOG("srv->Connections = %p", srv->Connections);
1022         LOG("srv->NewConnections = %p", srv->NewConnections);
1023         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
1024
1025         itoa(Dest, conn->Node.ImplInt, 16, 8, '0');
1026         Log_Log("TCP", "Thread %i got connection '%s'", Threads_GetTID(), Dest);
1027         LEAVE('i', 0);
1028         return 0;
1029 }
1030
1031 /**
1032  * \brief Gets a client connection node
1033  * \param Node  Server node
1034  * \param Name  Hexadecimal ID of the node
1035  */
1036 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags)
1037 {
1038         tTCPConnection  *conn;
1039         tTCPListener    *srv = Node->ImplPtr;
1040         char    tmp[9];
1041          int    id = atoi(Name);
1042
1043         ENTER("pNode sName", Node, Name);
1044
1045         // Check for a non-empty name
1046         if( Name[0] )
1047         {
1048                 // Sanity Check
1049                 itoa(tmp, id, 16, 8, '0');
1050                 if(strcmp(tmp, Name) != 0) {
1051                         LOG("'%s' != '%s' (%08x)", Name, tmp, id);
1052                         LEAVE('n');
1053                         return NULL;
1054                 }
1055
1056                 Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
1057                 Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
1058                 Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
1059
1060                 // Search
1061                 SHORTLOCK( &srv->lConnections );
1062                 for(conn = srv->Connections;
1063                         conn;
1064                         conn = conn->Next)
1065                 {
1066                         LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
1067                         if(conn->Node.ImplInt == id)    break;
1068                 }
1069                 SHORTREL( &srv->lConnections );
1070
1071                 // If not found, ret NULL
1072                 if(!conn) {
1073                         LOG("Connection %i not found", id);
1074                         LEAVE('n');
1075                         return NULL;
1076                 }
1077         }
1078         // Empty Name - Check for a new connection and if it's there, open it
1079         else
1080         {
1081                 SHORTLOCK( &srv->lConnections );
1082                 conn = srv->NewConnections;
1083                 if( conn != NULL )
1084                         srv->NewConnections = conn->Next;
1085                 VFS_MarkAvaliable( Node, srv->NewConnections != NULL );
1086                 SHORTREL( &srv->lConnections );
1087                 if( !conn ) {
1088                         LOG("No new connections");
1089                         LEAVE('n');
1090                         return NULL;
1091                 }
1092         }
1093
1094         // Return node
1095         LEAVE('p', &conn->Node);
1096         return &conn->Node;
1097 }
1098
1099 /**
1100  * \brief Handle IOCtl calls
1101  */
1102 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
1103 {
1104         tTCPListener    *srv = Node->ImplPtr;
1105
1106         switch(ID)
1107         {
1108         case 4: // Get/Set Port
1109                 if(!Data)       // Get Port
1110                         return srv->Port;
1111
1112                 if(srv->Port)   // Wait, you can't CHANGE the port
1113                         return -1;
1114
1115                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
1116                         return -1;
1117
1118                 // Permissions check
1119                 if(Threads_GetUID() != 0
1120                 && *(Uint16*)Data != 0
1121                 && *(Uint16*)Data < 1024)
1122                         return -1;
1123
1124                 // TODO: Check if a port is in use
1125
1126                 // Set Port
1127                 srv->Port = *(Uint16*)Data;
1128                 if(srv->Port == 0)      // Allocate a random port
1129                         srv->Port = TCP_GetUnusedPort();
1130                 else    // Else, mark this as used
1131                         TCP_AllocatePort(srv->Port);
1132
1133                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
1134
1135                 return srv->Port;
1136         }
1137         return 0;
1138 }
1139
1140 void TCP_Server_Close(tVFS_Node *Node)
1141 {
1142         free(Node->ImplPtr);
1143 }
1144
1145 // --- Client
1146 /**
1147  * \brief Create a client node
1148  */
1149 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1150 {
1151         tTCPConnection  *conn = TCP_int_CreateConnection(Interface, TCP_ST_CLOSED);
1152
1153         SHORTLOCK(&glTCP_OutbountCons);
1154         conn->Next = gTCP_OutbountCons;
1155         gTCP_OutbountCons = conn;
1156         SHORTREL(&glTCP_OutbountCons);
1157
1158         return &conn->Node;
1159 }
1160
1161 /**
1162  * \brief Wait for a packet and return it
1163  * \note If \a Length is smaller than the size of the packet, the rest
1164  *       of the packet's data will be discarded.
1165  */
1166 size_t TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
1167 {
1168         tTCPConnection  *conn = Node->ImplPtr;
1169         size_t  len;
1170
1171         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1172         LOG("conn = %p {State:%i}", conn, conn->State);
1173
1174         // If the connection has been closed (state > ST_OPEN) then clear
1175         // any stale data in the buffer (until it is empty (until it is empty))
1176         if( conn->State > TCP_ST_OPEN )
1177         {
1178                 Mutex_Acquire( &conn->lRecievedPackets );
1179                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1180                 Mutex_Release( &conn->lRecievedPackets );
1181
1182                 if( len == 0 ) {
1183                         VFS_MarkAvaliable(Node, 0);
1184                         errno = 0;
1185                         LEAVE('i', -1);
1186                         return -1;
1187                 }
1188
1189                 LEAVE('i', len);
1190                 return len;
1191         }
1192
1193         // Wait
1194         {
1195                 tTime   *timeout = NULL;
1196                 tTime   timeout_zero = 0;
1197                 if( Flags & VFS_IOFLAG_NOBLOCK )
1198                         timeout = &timeout_zero;
1199                 if( !VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, timeout, "TCP_Client_Read") ) {
1200                         errno = EWOULDBLOCK;
1201                         LEAVE('i', -1);
1202                         return -1;
1203                 }
1204         }
1205
1206         // Lock list and read as much as possible (up to `Length`)
1207         Mutex_Acquire( &conn->lRecievedPackets );
1208         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1209
1210         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1211                 LOG("Marking as none avaliable (len = %i)", len);
1212                 VFS_MarkAvaliable(Node, 0);
1213         }
1214
1215         // Release the lock (we don't need it any more)
1216         Mutex_Release( &conn->lRecievedPackets );
1217
1218         LEAVE('i', len);
1219         return len;
1220 }
1221
1222 /**
1223  * \brief Send a data packet on a connection
1224  */
1225 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, const void *Data)
1226 {
1227         char    buf[sizeof(tTCPHeader)+Length];
1228         tTCPHeader      *packet = (void*)buf;
1229
1230         // - Stop Delayed ACK timer (as this data packet ACKs)
1231         Time_RemoveTimer(Connection->DeferredACKTimer);
1232
1233         packet->SourcePort = htons(Connection->LocalPort);
1234         packet->DestPort = htons(Connection->RemotePort);
1235         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1236         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1237
1238         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1239         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1240         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1241         packet->UrgentPointer = 0;
1242
1243         memcpy(packet->Options, Data, Length);
1244
1245         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1246 #if HEXDUMP_OUTGOING
1247         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1248 #endif
1249
1250         TCP_SendPacket( Connection, packet, Length, Data );
1251
1252         Connection->NextSequenceSend += Length;
1253 }
1254
1255 /**
1256  * \brief Send some bytes on a connection
1257  */
1258 size_t TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
1259 {
1260         tTCPConnection  *conn = Node->ImplPtr;
1261         size_t  rem = Length;
1262
1263         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1264
1265 //      #if DEBUG
1266 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1267 //              Buffer, Length);
1268 //      #endif
1269
1270         // Don't allow a write to a closed connection
1271         if( conn->State > TCP_ST_OPEN ) {
1272                 VFS_MarkError(Node, 1);
1273                 errno = 0;
1274                 LEAVE('i', -1);
1275                 return -1;
1276         }
1277
1278         // Wait
1279         {
1280                 tTime   *timeout = NULL;
1281                 tTime   timeout_zero = 0;
1282                 if( Flags & VFS_IOFLAG_NOBLOCK )
1283                         timeout = &timeout_zero;
1284                 if( !VFS_SelectNode(Node, VFS_SELECT_WRITE|VFS_SELECT_ERROR, timeout, "TCP_Client_Write") ) {
1285                         errno = EWOULDBLOCK;
1286                         LEAVE('i', -1);
1287                         return -1;
1288                 }
1289         }
1290
1291         do
1292         {
1293                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1294
1295                 #if 0
1296                 // Wait for space in the buffer
1297                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1298
1299                 // Save data to buffer (and update the length read by the ammount written)
1300                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1301                 #endif
1302
1303                 // Send packet
1304                 TCP_INT_SendDataPacket(conn, len, Buffer);
1305
1306                 Buffer += len;
1307                 rem -= len;
1308         } while( rem > 0 );
1309
1310         LEAVE('i', Length);
1311         return Length;
1312 }
1313
1314 /**
1315  * \brief Open a connection to another host using TCP
1316  * \param Conn  Connection structure
1317  */
1318 void TCP_StartConnection(tTCPConnection *Conn)
1319 {
1320         tTCPHeader      hdr = {0};
1321
1322         Conn->State = TCP_ST_SYN_SENT;
1323
1324         hdr.SourcePort = htons(Conn->LocalPort);
1325         hdr.DestPort = htons(Conn->RemotePort);
1326         Conn->NextSequenceSend = rand();
1327         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1328         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1329         hdr.Flags = TCP_FLAG_SYN;
1330         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1331         hdr.Checksum = 0;       // TODO
1332
1333         TCP_SendPacket( Conn, &hdr, 0, NULL );
1334
1335         Conn->NextSequenceSend ++;
1336         Conn->State = TCP_ST_SYN_SENT;
1337
1338         return ;
1339 }
1340
1341 /**
1342  * \brief Control a client socket
1343  */
1344 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1345 {
1346         tTCPConnection  *conn = Node->ImplPtr;
1347
1348         ENTER("pNode iID pData", Node, ID, Data);
1349
1350         switch(ID)
1351         {
1352         case 4: // Get/Set local port
1353                 if(!Data)
1354                         LEAVE_RET('i', conn->LocalPort);
1355                 if(conn->State != TCP_ST_CLOSED)
1356                         LEAVE_RET('i', -1);
1357                 if(!CheckMem(Data, sizeof(Uint16)))
1358                         LEAVE_RET('i', -1);
1359
1360                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1361                         LEAVE_RET('i', -1);
1362
1363                 conn->LocalPort = *(Uint16*)Data;
1364                 LEAVE_RET('i', conn->LocalPort);
1365
1366         case 5: // Get/Set remote port
1367                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1368                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1369                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1370                 conn->RemotePort = *(Uint16*)Data;
1371                 LEAVE_RET('i', conn->RemotePort);
1372
1373         case 6: // Set Remote IP
1374                 if( conn->State != TCP_ST_CLOSED )
1375                         LEAVE_RET('i', -1);
1376                 if( conn->Interface->Type == 4 )
1377                 {
1378                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1379                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1380                 }
1381                 else if( conn->Interface->Type == 6 )
1382                 {
1383                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1384                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1385                 }
1386                 LEAVE_RET('i', 0);
1387
1388         case 7: // Connect
1389                 if(conn->LocalPort == 0xFFFF)
1390                         conn->LocalPort = TCP_GetUnusedPort();
1391                 if(conn->RemotePort == -1)
1392                         LEAVE_RET('i', 0);
1393
1394                 {
1395                         tTime   timeout = conn->Interface->TimeoutDelay;
1396
1397                         TCP_StartConnection(conn);
1398                         VFS_SelectNode(&conn->Node, VFS_SELECT_WRITE, &timeout, "TCP Connection");
1399                         if( conn->State == TCP_ST_SYN_SENT )
1400                                 LEAVE_RET('i', 0);
1401                 }
1402
1403                 LEAVE_RET('i', 1);
1404
1405         // Get recieve buffer length
1406         case 8:
1407                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1408         }
1409
1410         return 0;
1411 }
1412
1413 void TCP_Client_Close(tVFS_Node *Node)
1414 {
1415         tTCPConnection  *conn = Node->ImplPtr;
1416         tTCPHeader      packet;
1417
1418         ENTER("pNode", Node);
1419
1420         ASSERT(Node->ReferenceCount != 0);
1421
1422         if( Node->ReferenceCount > 1 ) {
1423                 Node->ReferenceCount --;
1424                 LOG("Dereference only");
1425                 LEAVE('-');
1426                 return ;
1427         }
1428
1429         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
1430         {
1431                 packet.SourcePort = htons(conn->LocalPort);
1432                 packet.DestPort = htons(conn->RemotePort);
1433                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1434                 packet.WindowSize = TCP_WINDOW_SIZE;
1435
1436                 packet.AcknowlegementNumber = 0;
1437                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1438                 packet.Flags = TCP_FLAG_FIN;
1439
1440                 TCP_SendPacket( conn, &packet, 0, NULL );
1441         }
1442
1443         switch( conn->State )
1444         {
1445         case TCP_ST_CLOSED:
1446                 Log_Warning("TCP", "Closing connection that was never opened");
1447                 break;
1448         case TCP_ST_CLOSE_WAIT:
1449                 conn->State = TCP_ST_LAST_ACK;
1450                 break;
1451         case TCP_ST_OPEN:
1452                 conn->State = TCP_ST_FIN_WAIT1;
1453                 while( conn->State == TCP_ST_FIN_WAIT1 )        Threads_Yield();
1454                 break;
1455         default:
1456                 Log_Warning("TCP", "Unhandled connection state %i in TCP_Client_Close",
1457                         conn->State);
1458                 break;
1459         }
1460
1461         Time_RemoveTimer(conn->DeferredACKTimer);
1462         Time_FreeTimer(conn->DeferredACKTimer);
1463         free(conn);
1464
1465         LEAVE('-');
1466 }
1467
1468 /**
1469  * \brief Checks if a value is between two others (after taking into account wrapping)
1470  */
1471 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1472 {
1473         if( MaxValue < 0xFFFFFFFF )
1474         {
1475                 Lower %= MaxValue + 1;
1476                 Value %= MaxValue + 1;
1477                 Higher %= MaxValue + 1;
1478         }
1479
1480         // Simple Case, no wrap ?
1481         //       Lower Value Higher
1482         // | ... + ... + ... + ... |
1483
1484         if( Lower < Higher ) {
1485                 return Lower < Value && Value < Higher;
1486         }
1487         // Higher has wrapped below lower
1488
1489         // Value > Lower ?
1490         //       Higher Lower Value
1491         // | ... +  ... + ... + ... |
1492         if( Value > Lower ) {
1493                 return 1;
1494         }
1495
1496         // Value < Higher ?
1497         //       Value Higher Lower
1498         // | ... + ... +  ... + ... |
1499         if( Value < Higher ) {
1500                 return 1;
1501         }
1502
1503         return 0;
1504 }