Usermode/libc - Fix strchr and strrchr behavior
[tpg/acess2.git] / 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        100
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_IPError(tInterface *Interface, tIPErrorMode Mode, const void *Address, int Length, const void *Buffer);
32  int    TCP_INT_HandleServerPacket(tInterface *Interface, tTCPListener *Server, const void *Address, tTCPHeader *Header, size_t Length);
33  int    TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length);
34 int     TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length);
35 void    TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection);
36 void    TCP_int_SendDelayedACK(void *ConnPtr);
37 void    TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason);
38 Uint16  TCP_GetUnusedPort();
39  int    TCP_AllocatePort(Uint16 Port);
40  int    TCP_DeallocatePort(Uint16 Port);
41 tTCPConnection  *TCP_int_CreateConnection(tInterface *Interface, enum eTCPConnectionState State);
42 void    TCP_int_FreeTCB(tTCPConnection *Connection);
43 // --- Server
44 tVFS_Node       *TCP_Server_Init(tInterface *Interface);
45  int    TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Name[FILENAME_MAX]);
46 tVFS_Node       *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags);
47  int    TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
48 void    TCP_Server_Close(tVFS_Node *Node);
49 // --- Client
50 tVFS_Node       *TCP_Client_Init(tInterface *Interface);
51 size_t  TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags);
52 size_t  TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags);
53  int    TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
54 void    TCP_Client_Close(tVFS_Node *Node);
55 // --- Helpers
56  int    WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
57 Uint32  GetRelative(Uint32 Base, Uint32 Value);
58
59 // === TEMPLATES ===
60 tSocketFile     gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
61 tSocketFile     gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
62 tVFS_NodeType   gTCP_ServerNodeType = {
63         .TypeName = "TCP Server",
64         .ReadDir = TCP_Server_ReadDir,
65         .FindDir = TCP_Server_FindDir,
66         .IOCtl   = TCP_Server_IOCtl,
67         .Close   = TCP_Server_Close
68         };
69 tVFS_NodeType   gTCP_ClientNodeType = {
70         .TypeName = "TCP Client/Connection",
71         .Flags = VFS_NODETYPEFLAG_STREAM,
72         .Read  = TCP_Client_Read,
73         .Write = TCP_Client_Write,
74         .IOCtl = TCP_Client_IOCtl,
75         .Close = TCP_Client_Close
76         };
77
78 // === GLOBALS ===
79  int    giTCP_NumHalfopen = 0;
80 tShortSpinlock  glTCP_Listeners;
81 tTCPListener    *gTCP_Listeners;
82 tShortSpinlock  glTCP_OutbountCons;
83 tTCPConnection  *gTCP_OutbountCons;
84 Uint32  gaTCP_PortBitmap[0x800];
85  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
86
87 // === CODE ===
88 /**
89  * \brief Initialise the TCP Layer
90  * 
91  * Registers the client and server files and the GetPacket callback
92  */
93 void TCP_Initialise(void)
94 {
95         giTCP_NextOutPort += rand()%128;
96         IPStack_AddFile(&gTCP_ServerFile);
97         IPStack_AddFile(&gTCP_ClientFile);
98         IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket, TCP_IPError);
99         IPv6_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
100 }
101
102 /**
103  * \brief Sends a packet from the specified connection, calculating the checksums
104  * \param Conn  Connection
105  * \param Length        Length of data
106  * \param Data  Packet data (cast as a TCP Header)
107  */
108 void TCP_SendPacket( tTCPConnection *Conn, tTCPHeader *Header, size_t Length, const void *Data )
109 {
110         TCP_int_SendPacket(Conn->Interface, &Conn->RemoteIP, Header, Length, Data);
111 }
112
113 Uint16 TCP_int_CalculateChecksum(int AddrType, const void *LAddr, const void *RAddr,
114         size_t HeaderLength, const tTCPHeader *Header, size_t DataLength, const void *Data)
115 {
116         size_t packlen = HeaderLength + DataLength;
117         Uint16  checksum[3];
118
119         switch(AddrType)
120         {
121         case 4: {
122                 Uint32  buf[3];
123                 buf[0] = ((tIPv4*)LAddr)->L;
124                 buf[1] = ((tIPv4*)RAddr)->L;
125                 buf[2] = htonl( (packlen) | (IP4PROT_TCP<<16) | (0<<24) );
126                 checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
127                 break; }
128         case 6: {
129                 Uint32  buf[4+4+1+1];
130                 memcpy(&buf[0], LAddr, 16);
131                 memcpy(&buf[4], RAddr, 16);
132                 buf[8] = htonl(packlen);
133                 buf[9] = htonl(IP4PROT_TCP);
134                 checksum[0] = htons( ~IPv4_Checksum(buf, sizeof(buf)) );        // Partial checksum
135                 break; }
136         default:
137                 return 0;
138         }
139         checksum[1] = htons( ~IPv4_Checksum(Header, HeaderLength) );
140         checksum[2] = htons( ~IPv4_Checksum(Data, DataLength) );
141
142         return htons( IPv4_Checksum(checksum, sizeof(checksum)) );
143 }
144
145 void TCP_int_SendPacket(tInterface *Interface, const void *Dest, tTCPHeader *Header, size_t Length, const void *Data )
146 {
147         tIPStackBuffer  *buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
148         if( Length > 0 )
149                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
150         IPStack_Buffer_AppendSubBuffer(buffer, sizeof(*Header), 0, Header, NULL, NULL);
151
152         #if TCP_DEBUG
153         Log_Log("TCP", "TCP_int_SendPacket: <Local>:%i to [%s]:%i (%i data), Flags = %s%s%s%s%s%s%s%s",
154                 ntohs(Header->SourcePort),
155                 IPStack_PrintAddress(Interface->Type, Dest),
156                 ntohs(Header->DestPort),
157                 Length,
158                 (Header->Flags & TCP_FLAG_CWR) ? "CWR " : "",
159                 (Header->Flags & TCP_FLAG_ECE) ? "ECE " : "",
160                 (Header->Flags & TCP_FLAG_URG) ? "URG " : "",
161                 (Header->Flags & TCP_FLAG_ACK) ? "ACK " : "",
162                 (Header->Flags & TCP_FLAG_PSH) ? "PSH " : "",
163                 (Header->Flags & TCP_FLAG_RST) ? "RST " : "",
164                 (Header->Flags & TCP_FLAG_SYN) ? "SYN " : "",
165                 (Header->Flags & TCP_FLAG_FIN) ? "FIN " : ""
166                 );
167         #endif
168
169         Header->Checksum = 0;
170         Header->Checksum = TCP_int_CalculateChecksum(Interface->Type, Interface->Address, Dest,
171                 sizeof(tTCPHeader), Header, Length, Data);
172         
173         // TODO: Fragment packet
174         
175         switch( Interface->Type )
176         {
177         case 4:
178                 IPv4_SendPacket(Interface, *(tIPv4*)Dest, IP4PROT_TCP, 0, buffer);
179                 break;
180         case 6:
181                 IPv6_SendPacket(Interface, *(tIPv6*)Dest, IP4PROT_TCP, buffer);
182                 break;
183         }
184 }
185
186 void TCP_int_SendRSTTo(tInterface *Interface, const void *Address, size_t Length, const tTCPHeader *Header)
187 {
188         tTCPHeader      out_hdr = {0};
189         
190         out_hdr.DataOffset = (sizeof(out_hdr)/4) << 4;
191         out_hdr.DestPort = Header->SourcePort;
192         out_hdr.SourcePort = Header->DestPort;
193
194         size_t  data_len = Length - (Header->DataOffset>>4)*4;
195         out_hdr.AcknowlegementNumber = htonl( ntohl(Header->SequenceNumber) + data_len );
196         if( Header->Flags & TCP_FLAG_ACK ) {
197                 out_hdr.Flags = TCP_FLAG_RST;
198                 out_hdr.SequenceNumber = Header->AcknowlegementNumber;
199         }
200         else {
201                 out_hdr.Flags = TCP_FLAG_RST|TCP_FLAG_ACK;
202                 out_hdr.SequenceNumber = 0;
203         }
204         TCP_int_SendPacket(Interface, Address, &out_hdr, 0, NULL);
205 }
206
207 /**
208  * \brief Handles a packet from the IP Layer
209  * \param Interface     Interface the packet arrived from
210  * \param Address       Pointer to the addres structure
211  * \param Length        Size of packet in bytes
212  * \param Buffer        Packet data
213  */
214 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
215 {
216         tTCPHeader      *hdr = Buffer;
217
218         #if TCP_DEBUG
219         Log_Log("TCP", "TCP_GetPacket: <Local>:%i from [%s]:%i, Flags = %s%s%s%s%s%s%s%s",
220                 ntohs(hdr->DestPort),
221                 IPStack_PrintAddress(Interface->Type, Address),
222                 ntohs(hdr->SourcePort),
223                 (hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
224                 (hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
225                 (hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
226                 (hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
227                 (hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
228                 (hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
229                 (hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
230                 (hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
231                 );
232         #endif
233
234         if( Length > (hdr->DataOffset >> 4)*4 )
235         {
236                 LOG("SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
237 #if HEXDUMP_INCOMING
238                 Debug_HexDump(
239                         "TCP_GetPacket: Packet Data = ",
240                         (Uint8*)hdr + (hdr->DataOffset >> 4)*4,
241                         Length - (hdr->DataOffset >> 4)*4
242                         );
243 #endif
244         }
245
246         // Check Servers
247         for( tTCPListener *srv = gTCP_Listeners; srv; srv = srv->Next )
248         {
249                 // Check if the server is active
250                 if(srv->Port == 0)      continue;
251                 // Check the interface
252                 if(srv->Interface && srv->Interface != Interface)       continue;
253                 // Check the destination port
254                 if(srv->Port != htons(hdr->DestPort))   continue;
255                 
256                 Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
257                 // Is this in an established connection?
258                 for( tTCPConnection *conn = srv->Connections; conn; conn = conn->Next )
259                 {
260                         // Check that it is coming in on the same interface
261                         if(conn->Interface != Interface)        continue;
262                         // Check Source Port
263                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
264                         // Check Source IP
265                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
266                                 continue ;
267
268                         Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
269                         // We have a response!
270                         if( TCP_INT_HandleConnectionPacket(conn, hdr, Length) == 0 )
271                                 return;
272                         break ;
273                 }
274
275                 TCP_INT_HandleServerPacket(Interface, srv, Address, hdr, Length);
276                 return ;
277         }
278
279         // Check Open Connections
280         {
281                 for( tTCPConnection *conn = gTCP_OutbountCons; conn; conn = conn->Next )
282                 {
283                         // Check that it is coming in on the same interface
284                         if(conn->Interface != Interface)        continue;
285
286                         // Check Source Port
287                         if(conn->RemotePort != ntohs(hdr->SourcePort))  continue;
288
289                         // Check Source IP
290                         if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
291                                 continue ;
292
293                         // Handle or fall through
294                         if( TCP_INT_HandleConnectionPacket(conn, hdr, Length) == 0 )
295                                 return ;
296                         break;
297                 }
298         }
299         
300         Log_Log("TCP", "TCP_GetPacket: No Match");
301         // If not a RST, send a RST
302         if( !(hdr->Flags & TCP_FLAG_RST) )
303         {
304                 TCP_int_SendRSTTo(Interface, Address, Length, hdr);
305         }
306 }
307
308 void TCP_IPError(tInterface *Interface, tIPErrorMode Mode, const void *Address, int Length, const void *Buffer)
309 {
310         if( Length < sizeof(tTCPHeader) )       return ;
311         
312         const tTCPHeader        *hdr = Buffer;
313         
314         // TODO: Handle errors for server connections
315         
316         for( tTCPConnection *conn = gTCP_OutbountCons; conn; conn = conn->Next )
317         {
318                 if(conn->Interface != Interface)
319                         continue;
320                 if(conn->RemotePort != ntohs(hdr->SourcePort))
321                         continue;
322                 if( IPStack_CompareAddress(conn->Interface->Type, &conn->RemoteIP, Address, -1) == 0 )
323                         continue ;
324                 
325                 // Mark an error on the interface
326                 VFS_MarkError(&conn->Node, 1);
327                 return ;
328         }
329 }
330
331 /*
332  * Handle packets in LISTEN state
333  */
334 int TCP_INT_HandleServerPacket(tInterface *Interface, tTCPListener *Server, const void *Address, tTCPHeader *Header, size_t Length)
335 {
336         if( Header->Flags & TCP_FLAG_RST ) {
337                 LOG("RST, ignore");
338                 return 0;
339         }
340         else if( Header->Flags & TCP_FLAG_ACK ) {
341                 LOG("ACK, send RST");
342                 TCP_int_SendRSTTo(Interface, Address, Length, Header);
343                 return 0;
344         }
345         else if( !(Header->Flags & TCP_FLAG_SYN) ) {
346                 LOG("Other, ignore");
347                 return 0;
348         }
349         
350         Log_Log("TCP", "TCP_GetPacket: Opening Connection");
351         
352         // TODO: Check security (a TCP Option)
353         // TODO: Check SEG.PRC 
354         // TODO: Check for halfopen max
355         
356         tTCPConnection *conn = TCP_int_CreateConnection(Interface, TCP_ST_SYN_RCVD);
357         conn->LocalPort = Server->Port;
358         conn->RemotePort = ntohs(Header->SourcePort);
359         
360         switch(Interface->Type)
361         {
362         case 4: conn->RemoteIP.v4 = *(tIPv4*)Address;   break;
363         case 6: conn->RemoteIP.v6 = *(tIPv6*)Address;   break;
364         default:        ASSERTC(Interface->Type,==,4);  return 0;
365         }
366         
367         conn->NextSequenceRcv = ntohl( Header->SequenceNumber ) + 1;
368         conn->HighestSequenceRcvd = conn->NextSequenceRcv;
369         conn->NextSequenceSend = rand();
370         conn->LastACKSequence = ntohl( Header->SequenceNumber );
371         
372         conn->Node.ImplInt = Server->NextID ++;
373         conn->Node.Size = -1;
374         
375         // Hmm... Theoretically, this lock will never have to wait,
376         // as the interface is locked to the watching thread, and this
377         // runs in the watching thread. But, it's a good idea to have
378         // it, just in case
379         // Oh, wait, there is a case where a wildcard can be used
380         // (Server->Interface == NULL) so having the lock is a good idea
381         SHORTLOCK(&Server->lConnections);
382         conn->Server = Server;
383         conn->Prev = Server->ConnectionsTail;
384         if(Server->Connections) {
385                 ASSERT(Server->ConnectionsTail);
386                 Server->ConnectionsTail->Next = conn;
387         }
388         else {
389                 ASSERT(!Server->ConnectionsTail);
390                 Server->Connections = conn;
391         }
392         Server->ConnectionsTail = conn;
393         if(!Server->NewConnections)
394                 Server->NewConnections = conn;
395         VFS_MarkAvaliable( &Server->Node, 1 );
396         SHORTREL(&Server->lConnections);
397         Semaphore_Signal(&Server->WaitingConnections, 1);
398
399         // Send the SYN ACK
400         Header->Flags = TCP_FLAG_ACK|TCP_FLAG_SYN;
401         Header->AcknowlegementNumber = htonl(conn->NextSequenceRcv);
402         Header->SequenceNumber = htonl(conn->NextSequenceSend);
403         Header->DestPort = Header->SourcePort;
404         Header->SourcePort = htons(Server->Port);
405         Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
406         TCP_SendPacket( conn, Header, 0, NULL );
407         conn->NextSequenceSend ++;
408         return 0;
409 }
410
411 /**
412  * \brief Handles a packet sent to a specific connection
413  * \param Connection    TCP Connection pointer
414  * \param Header        TCP Packet pointer
415  * \param Length        Length of the packet
416  */
417 int TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Header, int Length)
418 {
419          int    dataLen;
420         Uint32  sequence_num;
421         
422         // Silently drop once finished
423         // TODO: Check if this needs to be here
424         if( Connection->State == TCP_ST_FINISHED ) {
425                 Log_Log("TCP", "Packet ignored - connection finnished");
426                 return 1;
427         }
428         if( Connection->State == TCP_ST_FORCE_CLOSE ) {
429                 Log_Log("TCP", "Packet ignored - connection reset");
430                 return 1;
431         }
432         
433         // Syncronise sequence values
434         if(Header->Flags & TCP_FLAG_SYN) {
435                 // TODO: What if the packet also has data?
436                 if( Connection->LastACKSequence != Connection->NextSequenceRcv )
437                         TCP_INT_SendACK(Connection, "SYN");
438                 Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
439                 // TODO: Process HighestSequenceRcvd
440                 // HACK!
441                 if( Connection->HighestSequenceRcvd == 0 )
442                         Connection->HighestSequenceRcvd = Connection->NextSequenceRcv;
443                 Connection->LastACKSequence = Connection->NextSequenceRcv;
444         }
445         
446         // Ackowledge a sent packet
447         if(Header->Flags & TCP_FLAG_ACK) {
448                 // TODO: Process an ACKed Packet
449                 LOG("Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
450         }
451         
452         // Get length of data
453         dataLen = Length - (Header->DataOffset>>4)*4;
454         LOG("dataLen = %i", dataLen);
455         #if TCP_DEBUG
456         Log_Debug("TCP", "State %i, dataLen = %x", Connection->State, dataLen);
457         #endif
458         
459         // 
460         // State Machine
461         //
462         switch( Connection->State )
463         {
464         // Pre-init connection?
465         case TCP_ST_CLOSED:
466                 Log_Log("TCP", "Packets to a closed connection?!");
467                 break;
468         
469         // --- Init States ---
470         // SYN sent, expecting SYN-ACK Connection Opening
471         case TCP_ST_SYN_SENT:
472                 if( Header->Flags & TCP_FLAG_SYN )
473                 {
474                         if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
475                                 Connection->HighestSequenceRcvd ++;
476                         Connection->NextSequenceRcv ++;
477                         
478                         if( Header->Flags & TCP_FLAG_ACK )
479                         {       
480                                 Log_Log("TCP", "ACKing SYN-ACK");
481                                 Connection->State = TCP_ST_ESTABLISHED;
482                                 VFS_MarkFull(&Connection->Node, 0);
483                                 TCP_INT_SendACK(Connection, "SYN-ACK");
484                         }
485                         else
486                         {
487                                 Log_Log("TCP", "ACKing SYN");
488                                 Connection->State = TCP_ST_SYN_RCVD;
489                                 TCP_INT_SendACK(Connection, "SYN");
490                         }
491                 }
492                 break;
493         
494         // SYN-ACK sent, expecting ACK
495         case TCP_ST_SYN_RCVD:
496                 if( Header->Flags & TCP_FLAG_RST )
497                 {
498                         Log_Log("TCP", "RST Received, closing");
499                         Connection->State = TCP_ST_FORCE_CLOSE;
500                         VFS_MarkError(&Connection->Node, 1);
501                         return 0;
502                 }
503                 if( Header->Flags & TCP_FLAG_ACK )
504                 {
505                         // TODO: Handle max half-open limit
506                         Log_Log("TCP", "Connection fully opened");
507                         Connection->State = TCP_ST_ESTABLISHED;
508                         VFS_MarkFull(&Connection->Node, 0);
509                 }
510                 break;
511                 
512         // --- Established State ---
513         case TCP_ST_ESTABLISHED:
514                 // - Handle State changes
515                 //
516                 if( Header->Flags & TCP_FLAG_RST )
517                 {
518                         Log_Log("TCP", "Conn %p closed, received RST");
519                         // Error outstanding transactions
520                         Connection->State = TCP_ST_FORCE_CLOSE;
521                         VFS_MarkError(&Connection->Node, 1);
522                         return 0;
523                 }
524                 if( Header->Flags & TCP_FLAG_FIN ) {
525                         Log_Log("TCP", "Conn %p closed, recieved FIN", Connection);
526                         VFS_MarkError(&Connection->Node, 1);
527                         Connection->NextSequenceRcv ++;
528                         TCP_INT_SendACK(Connection, "FIN Received");
529                         Connection->State = TCP_ST_CLOSE_WAIT;
530                         // CLOSE WAIT requires the client to close
531                         return 0;
532                 }
533         
534                 // Check for an empty packet
535                 if(dataLen == 0) {
536                         if( Header->Flags == TCP_FLAG_ACK )
537                         {
538                                 Log_Log("TCP", "ACK only packet");
539                                 return 0;
540                         }
541                         // TODO: Is this right? (empty packet counts as one byte)
542                         if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
543                                 Connection->HighestSequenceRcvd ++;
544                         Connection->NextSequenceRcv ++;
545                         Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
546                         TCP_INT_SendACK(Connection, "Empty");
547                         return 0;
548                 }
549                 
550                 // NOTES:
551                 // Flags
552                 //    PSH - Has Data?
553                 // /NOTES
554                 
555                 sequence_num = ntohl(Header->SequenceNumber);
556                 
557                 LOG("0x%08x <= 0x%08x < 0x%08x",
558                         Connection->NextSequenceRcv,
559                         ntohl(Header->SequenceNumber),
560                         Connection->NextSequenceRcv + TCP_WINDOW_SIZE
561                         );
562                 
563                 // Is this packet the next expected packet?
564                 if( sequence_num == Connection->NextSequenceRcv )
565                 {
566                          int    rv;
567                         // Ooh, Goodie! Add it to the recieved list
568                         rv = TCP_INT_AppendRecieved(Connection,
569                                 (Uint8*)Header + (Header->DataOffset>>4)*4,
570                                 dataLen
571                                 );
572                         if(rv != 0) {
573                                 Log_Notice("TCP", "TCP_INT_AppendRecieved rv %i", rv);
574                                 break;
575                         }
576                         LOG("0x%08x += %i", Connection->NextSequenceRcv, dataLen);
577                         if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
578                                 Connection->HighestSequenceRcvd += dataLen;
579                         Connection->NextSequenceRcv += dataLen;
580                         
581                         // TODO: This should be moved out of the watcher thread,
582                         // so that a single lost packet on one connection doesn't cause
583                         // all connections on the interface to lag.
584                         // - Meh, no real issue, as the cache shouldn't be that large
585                         TCP_INT_UpdateRecievedFromFuture(Connection);
586
587                         #if 1
588                         // - Only send an ACK if we've had a burst
589                         Uint32  bytes_since_last_ack = Connection->NextSequenceRcv - Connection->LastACKSequence;
590                         LOG("bytes_since_last_ack = 0x%x", bytes_since_last_ack);
591                         if( bytes_since_last_ack > TCP_DACK_THRESHOLD )
592                         {
593                                 TCP_INT_SendACK(Connection, "DACK Burst");
594                                 // - Extend TCP deferred ACK timer
595                                 Time_RemoveTimer(Connection->DeferredACKTimer);
596                         }
597                         // - Schedule the deferred ACK timer (if already scheduled, this is a NOP)
598                         Time_ScheduleTimer(Connection->DeferredACKTimer, TCP_DACK_TIMEOUT);
599                         #else
600                         TCP_INT_SendACK(Connection, "RX");
601                         #endif
602                 }
603                 // Check if the packet is in window
604                 else if( sequence_num - Connection->NextSequenceRcv < TCP_WINDOW_SIZE )
605                 {
606                         Uint8   *dataptr = (Uint8*)Header + (Header->DataOffset>>4)*4;
607                         Uint32  index = sequence_num % TCP_WINDOW_SIZE;
608                         Uint32  max = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
609                         if( !(Connection->FuturePacketValidBytes[index/8] & (1 << (index%8))) )
610                                 TCP_INT_SendACK(Connection, "Lost packet");
611                         for( int i = 0; i < dataLen; i ++ )
612                         {
613                                 Connection->FuturePacketValidBytes[index/8] |= 1 << (index%8);
614                                 Connection->FuturePacketData[index] = dataptr[i];
615                                 // Do a wrap increment
616                                 index ++;
617                                 if(index == TCP_WINDOW_SIZE)    index = 0;
618                                 if(index == max)        break;
619                         }
620                         Uint32  rel_highest = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
621                         Uint32  rel_this = index - Connection->NextSequenceRcv;
622                         LOG("Updating highest this(0x%x) > highest(%x)", rel_this, rel_highest);
623                         if( rel_this > rel_highest )
624                         {
625                                 Connection->HighestSequenceRcvd = index;
626                         }
627                 }
628                 // Badly out of sequence packet
629                 else
630                 {
631                         Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
632                                 sequence_num, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
633                         // Spec says we should send an empty ACK with the current state
634                         TCP_INT_SendACK(Connection, "Bad Seq");
635                 }
636                 break;
637         
638         // --- Remote close states
639         case TCP_ST_CLOSE_WAIT:
640                 
641                 // Ignore everything, CLOSE_WAIT is terminated by the client
642                 Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
643                 
644                 break;
645         
646         // LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
647         case TCP_ST_LAST_ACK:
648                 if( Header->Flags & TCP_FLAG_ACK )
649                 {
650                         Connection->State = TCP_ST_FINISHED;    // Connection completed
651                         Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
652                         TCP_int_FreeTCB(Connection);
653                 }
654                 break;
655         
656         // --- Local close States
657         case TCP_ST_FIN_WAIT1:
658                 if( Header->Flags & TCP_FLAG_FIN )
659                 {
660                         Connection->State = TCP_ST_CLOSING;
661                         Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
662                         VFS_MarkError(&Connection->Node, 1);
663                         
664                         TCP_INT_SendACK(Connection, "FINWAIT-1 FIN");
665                         break ;
666                 }
667                 
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_FIN_WAIT2;
672                         Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
673                         VFS_MarkError(&Connection->Node, 1);
674                         return 0;
675                 }
676                 break;
677         
678         case TCP_ST_FIN_WAIT2:
679                 if( Header->Flags & TCP_FLAG_FIN )
680                 {
681                         Connection->State = TCP_ST_TIME_WAIT;
682                         Log_Debug("TCP", "Conn %p FINWAIT-2 -> TIME WAIT", Connection);
683                         TCP_INT_SendACK(Connection, "FINWAIT-2 FIN");
684                 }
685                 break;
686         
687         case TCP_ST_CLOSING:
688                 // TODO: Make sure that the packet is actually ACKing the FIN
689                 if( Header->Flags & TCP_FLAG_ACK )
690                 {
691                         Connection->State = TCP_ST_TIME_WAIT;
692                         Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
693                         VFS_MarkError(&Connection->Node, 1);
694                         return 0;
695                 }
696                 break;
697         
698         // --- Closed (or near closed) states) ---
699         case TCP_ST_TIME_WAIT:
700                 Log_Log("TCP", "Packets on Time-Wait, ignored");
701                 break;
702         
703         case TCP_ST_FINISHED:
704                 Log_Log("TCP", "Packets when CLOSED, ignoring");
705                 break;
706         case TCP_ST_FORCE_CLOSE:
707                 Log_Log("TCP", "Packets when force CLOSED, ignoring");
708                 return 1;
709         
710         //default:
711         //      Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
712         //      break;
713         }
714         
715         return 0;
716         
717 }
718
719 /**
720  * \brief Appends a packet to the recieved list
721  * \param Connection    Connection structure
722  * \param Data  Packet contents
723  * \param Length        Length of \a Data
724  */
725 int TCP_INT_AppendRecieved(tTCPConnection *Connection, const void *Data, size_t Length)
726 {
727         Mutex_Acquire( &Connection->lRecievedPackets );
728
729         if(Connection->RecievedBuffer->Length + Length > Connection->RecievedBuffer->Space )
730         {
731                 VFS_MarkAvaliable(&Connection->Node, 1);
732                 Log_Error("TCP", "Buffer filled, packet dropped (:%i) - %i + %i > %i",
733                         Connection->LocalPort, Connection->RecievedBuffer->Length, Length,
734                         Connection->RecievedBuffer->Space
735                         );
736                 Mutex_Release( &Connection->lRecievedPackets );
737                 return 1;
738         }
739         
740         RingBuffer_Write( Connection->RecievedBuffer, Data, Length );
741
742         VFS_MarkAvaliable(&Connection->Node, 1);
743         
744         Mutex_Release( &Connection->lRecievedPackets );
745         return 0;
746 }
747
748 /**
749  * \brief Updates the connections recieved list from the future list
750  * \param Connection    Connection structure
751  * 
752  * Updates the recieved packets list with packets from the future (out 
753  * of order) packets list that are now able to be added in direct
754  * sequence.
755  */
756 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
757 {
758         // Calculate length of contiguous bytes
759         const size_t    length = Connection->HighestSequenceRcvd - Connection->NextSequenceRcv;
760         Uint32  index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
761         size_t  runlength = length;
762         LOG("HSR=0x%x,NSR=0x%x", Connection->HighestSequenceRcvd, Connection->NextSequenceRcv);
763         if( Connection->HighestSequenceRcvd == Connection->NextSequenceRcv )
764         {
765                 return ;
766         }
767         LOG("length=%u, index=0x%x", length, index);
768         for( int i = 0; i < length; i ++ )
769         {
770                  int    bit = index % 8;
771                 Uint8   bitfield_byte = Connection->FuturePacketValidBytes[index / 8];
772                 if( (bitfield_byte & (1 << bit)) == 0 ) {
773                         runlength = i;
774                         LOG("Hit missing, break");
775                         break;
776                 }
777
778                 if( bitfield_byte == 0xFF ) {
779                          int    inc = 8 - bit;
780                         i += inc - 1;
781                         index += inc;
782                 }
783                 else {
784                         index ++;
785                 }
786                 if(index > TCP_WINDOW_SIZE)
787                         index -= TCP_WINDOW_SIZE;
788         }
789         
790         index = Connection->NextSequenceRcv % TCP_WINDOW_SIZE;
791         Connection->NextSequenceRcv += runlength;
792         
793         // Write data to to the ring buffer
794         if( TCP_WINDOW_SIZE - index > runlength )
795         {
796                 // Simple case
797                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, runlength );
798         }
799         else
800         {
801                  int    endLen = TCP_WINDOW_SIZE - index;
802                 // 2-part case
803                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData + index, endLen );
804                 RingBuffer_Write( Connection->RecievedBuffer, Connection->FuturePacketData, endLen - runlength );
805         }
806         
807         // Mark (now saved) bytes as invalid
808         // - Align index
809         while(index % 8 && runlength > 0)
810         {
811                 Connection->FuturePacketData[index] = 0;
812                 Connection->FuturePacketValidBytes[index/8] &= ~(1 << (index%8));
813                 index ++;
814                 if(index > TCP_WINDOW_SIZE)
815                         index -= TCP_WINDOW_SIZE;
816                 runlength --;
817         }
818         while( runlength > 7 )
819         {
820                 Connection->FuturePacketData[index] = 0;
821                 Connection->FuturePacketValidBytes[index/8] = 0;
822                 runlength -= 8;
823                 index += 8;
824                 if(index > TCP_WINDOW_SIZE)
825                         index -= TCP_WINDOW_SIZE;
826         }
827         while( runlength > 0)
828         {
829                 Connection->FuturePacketData[index] = 0;
830                 Connection->FuturePacketData[index/8] &= ~(1 << (index%8));
831                 index ++;
832                 if(index > TCP_WINDOW_SIZE)
833                         index -= TCP_WINDOW_SIZE;
834                 runlength --;
835         }
836 }
837
838 void TCP_int_SendDelayedACK(void *ConnPtr)
839 {
840         TCP_INT_SendACK(ConnPtr, "DACK Timeout");
841 }
842
843 void TCP_INT_SendACK(tTCPConnection *Connection, const char *Reason)
844 {
845         tTCPHeader      hdr;
846         // ACK Packet
847         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
848         hdr.DestPort = htons(Connection->RemotePort);
849         hdr.SourcePort = htons(Connection->LocalPort);
850         hdr.AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
851         hdr.SequenceNumber = htonl(Connection->NextSequenceSend);
852         hdr.WindowSize = htons(TCP_WINDOW_SIZE);
853         hdr.Flags = TCP_FLAG_ACK;       // TODO: Determine if SYN is wanted too
854         hdr.Checksum = 0;       // TODO: Checksum
855         hdr.UrgentPointer = 0;
856         Log_Debug("TCP", "Sending ACK for 0x%08x (%s)", Connection->NextSequenceRcv, Reason);
857         TCP_SendPacket( Connection, &hdr, 0, NULL );
858         //Connection->NextSequenceSend ++;
859         Connection->LastACKSequence = Connection->NextSequenceRcv;
860 }
861
862 /**
863  * \fn Uint16 TCP_GetUnusedPort()
864  * \brief Gets an unused port and allocates it
865  */
866 Uint16 TCP_GetUnusedPort()
867 {
868         Uint16  ret;
869
870         // Get Next outbound port
871         ret = giTCP_NextOutPort++;
872         while( gaTCP_PortBitmap[ret/32] & (1UL << (ret%32)) )
873         {
874                 ret ++;
875                 giTCP_NextOutPort++;
876                 if(giTCP_NextOutPort == 0x10000) {
877                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
878                 }
879         }
880
881         // Mark the new port as used
882         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
883
884         return ret;
885 }
886
887 /**
888  * \fn int TCP_AllocatePort(Uint16 Port)
889  * \brief Marks a port as used
890  */
891 int TCP_AllocatePort(Uint16 Port)
892 {
893         // Check if the port has already been allocated
894         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
895                 return 0;
896
897         // Allocate
898         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
899
900         return 1;
901 }
902
903 /**
904  * \fn int TCP_DeallocatePort(Uint16 Port)
905  * \brief Marks a port as unused
906  */
907 int TCP_DeallocatePort(Uint16 Port)
908 {
909         // Check if the port has already been allocated
910         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
911                 return 0;
912
913         // Allocate
914         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
915
916         return 1;
917 }
918
919 tTCPConnection *TCP_int_CreateConnection(tInterface *Interface, enum eTCPConnectionState State)
920 {
921         tTCPConnection  *conn = calloc( sizeof(tTCPConnection) + TCP_WINDOW_SIZE + TCP_WINDOW_SIZE/8, 1 );
922
923         conn->State = State;
924         conn->Interface = Interface;
925         conn->LocalPort = -1;
926         conn->RemotePort = -1;
927
928         conn->Node.Size = -1;
929         conn->Node.ReferenceCount = 1;
930         conn->Node.ImplPtr = conn;
931         conn->Node.NumACLs = 1;
932         conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
933         conn->Node.Type = &gTCP_ClientNodeType;
934         conn->Node.BufferFull = 1;      // Cleared when connection opens
935
936         conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
937         #if 0
938         conn->SentBuffer = RingBuffer_Create( TCP_SEND_BUFFER_SIZE );
939         Semaphore_Init(conn->SentBufferSpace, 0, TCP_SEND_BUFFER_SIZE, "TCP SentBuffer", conn->Name);
940         #endif
941         
942         conn->HighestSequenceRcvd = 0;
943         #if CACHE_FUTURE_PACKETS_IN_BYTES
944         // Future recieved data (ahead of the expected sequence number)
945         conn->FuturePacketData = (Uint8*)conn + sizeof(tTCPConnection);
946         conn->FuturePacketValidBytes = conn->FuturePacketData + TCP_WINDOW_SIZE;
947         #endif
948
949         conn->DeferredACKTimer = Time_AllocateTimer( TCP_int_SendDelayedACK, conn);
950         return conn;
951 }
952
953 void TCP_int_FreeTCB(tTCPConnection *Connection)
954 {
955         ASSERTC(Connection->State, ==, TCP_ST_FINISHED);
956         ASSERTC(Connection->Node.ReferenceCount, ==, 0);
957
958         if( Connection->Server )
959         {
960                 tTCPListener    *srv = Connection->Server;
961                 SHORTLOCK(&srv->lConnections);
962                 if(Connection->Prev)
963                         Connection->Prev->Next = Connection->Next;
964                 else
965                         srv->Connections = Connection->Next;
966                 if(Connection->Next)
967                         Connection->Next->Prev = Connection->Prev;
968                 else {
969                         ASSERT(srv->ConnectionsTail == Connection);
970                         srv->ConnectionsTail = Connection->Prev;
971                 }
972                 SHORTREL(&srv->lConnections);
973         }
974         else
975         {
976                 SHORTLOCK(&glTCP_OutbountCons);
977                 if(Connection->Prev)
978                         Connection->Prev->Next = Connection->Next;
979                 else
980                         gTCP_OutbountCons = Connection->Next;
981                 if(Connection->Next)
982                         Connection->Next->Prev = Connection->Prev;
983                 else
984                         ;
985                 SHORTREL(&glTCP_OutbountCons);
986         }
987
988         RingBuffer_Free(Connection->RecievedBuffer);
989         Time_FreeTimer(Connection->DeferredACKTimer);
990         // TODO: Force VFS to close handles? (they should all be closed);
991         free(Connection);
992 }
993
994 // --- Server
995 tVFS_Node *TCP_Server_Init(tInterface *Interface)
996 {
997         tTCPListener    *srv;
998         
999         srv = calloc( 1, sizeof(tTCPListener) );
1000
1001         if( srv == NULL ) {
1002                 Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
1003                 return NULL;
1004         }
1005
1006         srv->Interface = Interface;
1007         srv->Port = 0;
1008         srv->NextID = 0;
1009         srv->Connections = NULL;
1010         srv->ConnectionsTail = NULL;
1011         srv->NewConnections = NULL;
1012         srv->Next = NULL;
1013         srv->Node.Flags = VFS_FFLAG_DIRECTORY;
1014         srv->Node.Size = -1;
1015         srv->Node.ImplPtr = srv;
1016         srv->Node.NumACLs = 1;
1017         srv->Node.ACLs = &gVFS_ACL_EveryoneRW;
1018         srv->Node.Type = &gTCP_ServerNodeType;
1019
1020         SHORTLOCK(&glTCP_Listeners);
1021         srv->Next = gTCP_Listeners;
1022         gTCP_Listeners = srv;
1023         SHORTREL(&glTCP_Listeners);
1024
1025         return &srv->Node;
1026 }
1027
1028 /**
1029  * \brief Wait for a new connection and return the connection ID
1030  * \note Blocks until a new connection is made
1031  * \param Node  Server node
1032  * \param Pos   Position (ignored)
1033  */
1034 int TCP_Server_ReadDir(tVFS_Node *Node, int Pos, char Dest[FILENAME_MAX])
1035 {
1036         tTCPListener    *srv = Node->ImplPtr;
1037         tTCPConnection  *conn;
1038         
1039         ENTER("pNode iPos", Node, Pos);
1040
1041         Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
1042         Semaphore_Wait( &srv->WaitingConnections, 1 );
1043         
1044         SHORTLOCK(&srv->lConnections);
1045         // Increment the new list (the current connection is still on the 
1046         // normal list)
1047         conn = srv->NewConnections;
1048         srv->NewConnections = conn->Next;
1049
1050         if( srv->NewConnections == NULL )
1051                 VFS_MarkAvaliable( Node, 0 );
1052         
1053         SHORTREL( &srv->lConnections );
1054         
1055         LOG("conn = %p", conn);
1056         LOG("srv->Connections = %p", srv->Connections);
1057         LOG("srv->NewConnections = %p", srv->NewConnections);
1058         LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
1059
1060         itoa(Dest, conn->Node.ImplInt, 16, 8, '0');
1061         Log_Log("TCP", "Thread %i got connection '%s'", Threads_GetTID(), Dest);
1062         LEAVE('i', 0);
1063         return 0;
1064 }
1065
1066 /**
1067  * \brief Gets a client connection node
1068  * \param Node  Server node
1069  * \param Name  Hexadecimal ID of the node
1070  */
1071 tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name, Uint Flags)
1072 {
1073         tTCPConnection  *conn;
1074         tTCPListener    *srv = Node->ImplPtr;
1075         char    tmp[9];
1076          int    id = atoi(Name);
1077         
1078         ENTER("pNode sName", Node, Name);
1079
1080         // Check for a non-empty name
1081         if( Name[0] ) 
1082         {       
1083                 // Sanity Check
1084                 itoa(tmp, id, 16, 8, '0');
1085                 if(strcmp(tmp, Name) != 0) {
1086                         LOG("'%s' != '%s' (%08x)", Name, tmp, id);
1087                         LEAVE('n');
1088                         return NULL;
1089                 }
1090                 
1091                 Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
1092                 Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
1093                 Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
1094                 
1095                 // Search
1096                 SHORTLOCK( &srv->lConnections );
1097                 for(conn = srv->Connections;
1098                         conn;
1099                         conn = conn->Next)
1100                 {
1101                         LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
1102                         if(conn->Node.ImplInt == id)    break;
1103                 }
1104                 SHORTREL( &srv->lConnections );
1105
1106                 // If not found, ret NULL
1107                 if(!conn) {
1108                         LOG("Connection %i not found", id);
1109                         LEAVE('n');
1110                         return NULL;
1111                 }
1112         }
1113         // Empty Name - Check for a new connection and if it's there, open it
1114         else
1115         {
1116                 SHORTLOCK( &srv->lConnections );
1117                 conn = srv->NewConnections;
1118                 if( conn != NULL )
1119                         srv->NewConnections = conn->Next;
1120                 VFS_MarkAvaliable( Node, srv->NewConnections != NULL );
1121                 SHORTREL( &srv->lConnections );
1122                 if( !conn ) {
1123                         LOG("No new connections");
1124                         LEAVE('n');
1125                         return NULL;
1126                 }
1127         }
1128                 
1129         // Return node
1130         LEAVE('p', &conn->Node);
1131         return &conn->Node;
1132 }
1133
1134 /**
1135  * \brief Handle IOCtl calls
1136  */
1137 int TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data)
1138 {
1139         tTCPListener    *srv = Node->ImplPtr;
1140
1141         switch(ID)
1142         {
1143         case 4: // Get/Set Port
1144                 if(!Data)       // Get Port
1145                         return srv->Port;
1146
1147                 if(srv->Port)   // Wait, you can't CHANGE the port
1148                         return -1;
1149
1150                 if(!CheckMem(Data, sizeof(Uint16)))     // Sanity check
1151                         return -1;
1152
1153                 // Permissions check
1154                 if(Threads_GetUID() != 0
1155                 && *(Uint16*)Data != 0
1156                 && *(Uint16*)Data < 1024)
1157                         return -1;
1158
1159                 // TODO: Check if a port is in use
1160
1161                 // Set Port
1162                 srv->Port = *(Uint16*)Data;
1163                 if(srv->Port == 0)      // Allocate a random port
1164                         srv->Port = TCP_GetUnusedPort();
1165                 else    // Else, mark this as used
1166                         TCP_AllocatePort(srv->Port);
1167                 
1168                 Log_Log("TCP", "Server %p listening on port %i", srv, srv->Port);
1169                 
1170                 return srv->Port;
1171         }
1172         return 0;
1173 }
1174
1175 void TCP_Server_Close(tVFS_Node *Node)
1176 {
1177         free(Node->ImplPtr);
1178 }
1179
1180 // --- Client
1181 /**
1182  * \brief Create a client node
1183  */
1184 tVFS_Node *TCP_Client_Init(tInterface *Interface)
1185 {
1186         tTCPConnection  *conn = TCP_int_CreateConnection(Interface, TCP_ST_CLOSED);
1187
1188         SHORTLOCK(&glTCP_OutbountCons);
1189         conn->Server = NULL;
1190         conn->Prev = NULL;
1191         conn->Next = gTCP_OutbountCons;
1192         if(gTCP_OutbountCons)
1193                 gTCP_OutbountCons->Prev = conn;
1194         gTCP_OutbountCons = conn;
1195         SHORTREL(&glTCP_OutbountCons);
1196
1197         return &conn->Node;
1198 }
1199
1200 /**
1201  * \brief Wait for a packet and return it
1202  * \note If \a Length is smaller than the size of the packet, the rest
1203  *       of the packet's data will be discarded.
1204  */
1205 size_t TCP_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer, Uint Flags)
1206 {
1207         tTCPConnection  *conn = Node->ImplPtr;
1208         size_t  len;
1209         
1210         ENTER("pNode XOffset xLength pBuffer", Node, Offset, Length, Buffer);
1211         LOG("conn = %p {State:%i}", conn, conn->State);
1212         
1213         // If the connection has been closed (state > ST_OPEN) then clear
1214         // any stale data in the buffer (until it is empty (until it is empty))
1215         if( conn->State > TCP_ST_ESTABLISHED )
1216         {
1217                 LOG("Connection closed");
1218                 Mutex_Acquire( &conn->lRecievedPackets );
1219                 len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1220                 Mutex_Release( &conn->lRecievedPackets );
1221                 
1222                 if( len == 0 ) {
1223                         VFS_MarkAvaliable(Node, 0);
1224                         errno = 0;
1225                         LEAVE('i', -1);
1226                         return -1;
1227                 }
1228                 
1229                 LEAVE('i', len);
1230                 return len;
1231         }
1232         
1233         // Wait
1234         {
1235                 tTime   *timeout = NULL;
1236                 tTime   timeout_zero = 0;
1237                 if( Flags & VFS_IOFLAG_NOBLOCK )
1238                         timeout = &timeout_zero;
1239                 if( !VFS_SelectNode(Node, VFS_SELECT_READ|VFS_SELECT_ERROR, timeout, "TCP_Client_Read") ) {
1240                         errno = EWOULDBLOCK;
1241                         LEAVE('i', -1);
1242                         return -1;
1243                 }
1244         }
1245         
1246         // Lock list and read as much as possible (up to `Length`)
1247         Mutex_Acquire( &conn->lRecievedPackets );
1248         len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
1249         
1250         if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
1251                 LOG("Marking as none avaliable (len = %i)", len);
1252                 VFS_MarkAvaliable(Node, 0);
1253         }
1254                 
1255         // Release the lock (we don't need it any more)
1256         Mutex_Release( &conn->lRecievedPackets );
1257
1258         LEAVE('i', len);
1259         return len;
1260 }
1261
1262 /**
1263  * \brief Send a data packet on a connection
1264  */
1265 void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, const void *Data)
1266 {
1267         char    buf[sizeof(tTCPHeader)+Length];
1268         tTCPHeader      *packet = (void*)buf;
1269
1270         // - Stop Delayed ACK timer (as this data packet ACKs)
1271         Time_RemoveTimer(Connection->DeferredACKTimer);
1272
1273         // TODO: Don't exceed window size
1274         
1275         packet->SourcePort = htons(Connection->LocalPort);
1276         packet->DestPort = htons(Connection->RemotePort);
1277         packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
1278         packet->WindowSize = htons(TCP_WINDOW_SIZE);
1279         
1280         packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
1281         packet->SequenceNumber = htonl(Connection->NextSequenceSend);
1282         packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;      // Hey, ACK if you can!
1283         packet->UrgentPointer = 0;
1284         
1285         memcpy(packet->Options, Data, Length);
1286         
1287         Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
1288 #if HEXDUMP_OUTGOING
1289         Debug_HexDump("TCP_INT_SendDataPacket: Data = ", Data, Length);
1290 #endif
1291         
1292         TCP_SendPacket( Connection, packet, Length, Data );
1293         
1294         // TODO: Start a retransmit time (if data is not ACKed in x seconds, send again)
1295         
1296         Connection->NextSequenceSend += Length;
1297 }
1298
1299 /**
1300  * \brief Send some bytes on a connection
1301  */
1302 size_t TCP_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer, Uint Flags)
1303 {
1304         tTCPConnection  *conn = Node->ImplPtr;
1305         size_t  rem = Length;
1306         
1307         ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
1308         
1309 //      #if DEBUG
1310 //      Debug_HexDump("TCP_Client_Write: Buffer = ",
1311 //              Buffer, Length);
1312 //      #endif
1313         
1314         // Don't allow a write to a closed connection
1315         if( conn->State > TCP_ST_ESTABLISHED ) {
1316                 VFS_MarkError(Node, 1);
1317                 errno = 0;
1318                 LEAVE('i', -1);
1319                 return -1;
1320         }
1321         
1322         // Wait
1323         {
1324                 tTime   *timeout = NULL;
1325                 tTime   timeout_zero = 0;
1326                 if( Flags & VFS_IOFLAG_NOBLOCK )
1327                         timeout = &timeout_zero;
1328                 if( !VFS_SelectNode(Node, VFS_SELECT_WRITE|VFS_SELECT_ERROR, timeout, "TCP_Client_Write") ) {
1329                         errno = EWOULDBLOCK;
1330                         LEAVE('i', -1);
1331                         return -1;
1332                 }
1333         }
1334         
1335         do
1336         {
1337                  int    len = (rem < TCP_MAX_PACKET_SIZE) ? rem : TCP_MAX_PACKET_SIZE;
1338                 
1339                 #if 0
1340                 // Wait for space in the buffer
1341                 Semaphore_Signal( &Connection->SentBufferSpace, len );
1342                 
1343                 // Save data to buffer (and update the length read by the ammount written)
1344                 len = RingBuffer_Write( &Connection->SentBuffer, Buffer, len);
1345                 #endif
1346                 
1347                 // Send packet
1348                 TCP_INT_SendDataPacket(conn, len, Buffer);
1349                 
1350                 Buffer += len;
1351                 rem -= len;
1352         } while( rem > 0 );
1353         
1354         LEAVE('i', Length);
1355         return Length;
1356 }
1357
1358 /**
1359  * \brief Open a connection to another host using TCP
1360  * \param Conn  Connection structure
1361  */
1362 void TCP_StartConnection(tTCPConnection *Conn)
1363 {
1364         tTCPHeader      hdr = {0};
1365
1366         Conn->State = TCP_ST_SYN_SENT;
1367
1368         hdr.SourcePort = htons(Conn->LocalPort);
1369         hdr.DestPort = htons(Conn->RemotePort);
1370         Conn->NextSequenceSend = rand();
1371         hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
1372         hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
1373         hdr.Flags = TCP_FLAG_SYN;
1374         hdr.WindowSize = htons(TCP_WINDOW_SIZE);        // Max
1375         hdr.Checksum = 0;       // TODO
1376         
1377         TCP_SendPacket( Conn, &hdr, 0, NULL );
1378         
1379         Conn->NextSequenceSend ++;
1380         Conn->State = TCP_ST_SYN_SENT;
1381
1382         return ;
1383 }
1384
1385 /**
1386  * \brief Control a client socket
1387  */
1388 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
1389 {
1390         tTCPConnection  *conn = Node->ImplPtr;
1391         
1392         ENTER("pNode iID pData", Node, ID, Data);
1393
1394         switch(ID)
1395         {
1396         case 4: // Get/Set local port
1397                 if(!Data)
1398                         LEAVE_RET('i', conn->LocalPort);
1399                 if(conn->State != TCP_ST_CLOSED)
1400                         LEAVE_RET('i', -1);
1401                 if(!CheckMem(Data, sizeof(Uint16)))
1402                         LEAVE_RET('i', -1);
1403
1404                 if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
1405                         LEAVE_RET('i', -1);
1406
1407                 conn->LocalPort = *(Uint16*)Data;
1408                 LEAVE_RET('i', conn->LocalPort);
1409
1410         case 5: // Get/Set remote port
1411                 if(!Data)       LEAVE_RET('i', conn->RemotePort);
1412                 if(conn->State != TCP_ST_CLOSED)        LEAVE_RET('i', -1);
1413                 if(!CheckMem(Data, sizeof(Uint16)))     LEAVE_RET('i', -1);
1414                 conn->RemotePort = *(Uint16*)Data;
1415                 LEAVE_RET('i', conn->RemotePort);
1416
1417         case 6: // Set Remote IP
1418                 if( conn->State != TCP_ST_CLOSED )
1419                         LEAVE_RET('i', -1);
1420                 if( conn->Interface->Type == 4 )
1421                 {
1422                         if(!CheckMem(Data, sizeof(tIPv4)))      LEAVE_RET('i', -1);
1423                         conn->RemoteIP.v4 = *(tIPv4*)Data;
1424                 }
1425                 else if( conn->Interface->Type == 6 )
1426                 {
1427                         if(!CheckMem(Data, sizeof(tIPv6)))      LEAVE_RET('i', -1);
1428                         conn->RemoteIP.v6 = *(tIPv6*)Data;
1429                 }
1430                 LEAVE_RET('i', 0);
1431
1432         case 7: // Connect
1433                 if(conn->LocalPort == 0xFFFF)
1434                         conn->LocalPort = TCP_GetUnusedPort();
1435                 if(conn->RemotePort == -1)
1436                         LEAVE_RET('i', 0);
1437
1438                 {
1439                         tTime   timeout = conn->Interface->TimeoutDelay;
1440         
1441                         TCP_StartConnection(conn);
1442                         VFS_SelectNode(&conn->Node, VFS_SELECT_WRITE, &timeout, "TCP Connection");
1443                         if( conn->State == TCP_ST_SYN_SENT )
1444                                 LEAVE_RET('i', 0);
1445                 }
1446
1447                 LEAVE_RET('i', 1);
1448         
1449         // Get recieve buffer length
1450         case 8:
1451                 LEAVE_RET('i', conn->RecievedBuffer->Length);
1452         }
1453
1454         return 0;
1455 }
1456
1457 void TCP_Client_Close(tVFS_Node *Node)
1458 {
1459         tTCPConnection  *conn = Node->ImplPtr;
1460         tTCPHeader      packet;
1461         
1462         ENTER("pNode", Node);
1463         
1464         ASSERT(Node->ReferenceCount != 0);
1465
1466         if( Node->ReferenceCount > 1 ) {
1467                 Node->ReferenceCount --;
1468                 LOG("Dereference only");
1469                 LEAVE('-');
1470                 return ;
1471         }
1472         Node->ReferenceCount --;
1473         
1474         if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_ESTABLISHED )
1475         {
1476                 packet.SourcePort = htons(conn->LocalPort);
1477                 packet.DestPort = htons(conn->RemotePort);
1478                 packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
1479                 packet.WindowSize = TCP_WINDOW_SIZE;
1480                 
1481                 packet.AcknowlegementNumber = 0;
1482                 packet.SequenceNumber = htonl(conn->NextSequenceSend);
1483                 packet.Flags = TCP_FLAG_FIN;
1484                 
1485                 TCP_SendPacket( conn, &packet, 0, NULL );
1486         }
1487         
1488         Time_RemoveTimer(conn->DeferredACKTimer);
1489         
1490         switch( conn->State )
1491         {
1492         case TCP_ST_CLOSED:
1493                 Log_Warning("TCP", "Closing connection that was never opened");
1494                 TCP_int_FreeTCB(conn);
1495                 break;
1496         case TCP_ST_FORCE_CLOSE:
1497                 conn->State = TCP_ST_FINISHED;
1498                 TCP_int_FreeTCB(conn);
1499                 break;
1500         case TCP_ST_CLOSE_WAIT:
1501                 conn->State = TCP_ST_LAST_ACK;
1502                 break;
1503         case TCP_ST_ESTABLISHED:
1504                 conn->State = TCP_ST_FIN_WAIT1;
1505                 while( conn->State == TCP_ST_FIN_WAIT1 )
1506                         Threads_Yield();
1507                 // No free, freed after TIME_WAIT
1508                 break;
1509         default:
1510                 Log_Warning("TCP", "Unhandled connection state %i in TCP_Client_Close",
1511                         conn->State);
1512                 break;
1513         }
1514         
1515         LEAVE('-');
1516 }
1517
1518 /**
1519  * \brief Checks if a value is between two others (after taking into account wrapping)
1520  */
1521 int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
1522 {
1523         if( MaxValue < 0xFFFFFFFF )
1524         {
1525                 Lower %= MaxValue + 1;
1526                 Value %= MaxValue + 1;
1527                 Higher %= MaxValue + 1;
1528         }
1529         
1530         // Simple Case, no wrap ?
1531         //       Lower Value Higher
1532         // | ... + ... + ... + ... |
1533
1534         if( Lower < Higher ) {
1535                 return Lower < Value && Value < Higher;
1536         }
1537         // Higher has wrapped below lower
1538         
1539         // Value > Lower ?
1540         //       Higher Lower Value
1541         // | ... +  ... + ... + ... |
1542         if( Value > Lower ) {
1543                 return 1;
1544         }
1545         
1546         // Value < Higher ?
1547         //       Value Higher Lower
1548         // | ... + ... +  ... + ... |
1549         if( Value < Higher ) {
1550                 return 1;
1551         }
1552         
1553         return 0;
1554 }
1555 Uint32 GetRelative(Uint32 Base, Uint32 Value)
1556 {
1557         if( Value < Base )
1558                 return Value - Base + 0xFFFFFFFF;
1559         else
1560                 return Value - Base;
1561 }

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