X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Modules%2FIPStack%2Ftcp.c;h=50eacbc64a33fcaff1d0ac4da6ed1eabc46d84c2;hb=a200e721cb12cbfdb09e32089bd31b4ad84baa67;hp=e7cded3eb02d006b844db57f9f231de58645bfae;hpb=4e2291b425621d70278b1d38c644aaa2715300ce;p=tpg%2Facess2.git

diff --git a/Modules/IPStack/tcp.c b/Modules/IPStack/tcp.c
index e7cded3e..50eacbc6 100644
--- a/Modules/IPStack/tcp.c
+++ b/Modules/IPStack/tcp.c
@@ -2,13 +2,20 @@
  * Acess2 IP Stack
  * - TCP Handling
  */
+#define DEBUG	1
 #include "ipstack.h"
 #include "ipv4.h"
 #include "tcp.h"
 
+#define USE_SELECT	1
+
 #define TCP_MIN_DYNPORT	0xC000
 #define TCP_MAX_HALFOPEN	1024	// Should be enough
 
+#define TCP_MAX_PACKET_SIZE	1024
+#define TCP_WINDOW_SIZE	0x2000
+#define TCP_RECIEVE_BUFFER_SIZE	0x4000
+
 // === PROTOTYPES ===
 void	TCP_Initialise();
 void	TCP_StartConnection(tTCPConnection *Conn);
@@ -23,7 +30,7 @@ Uint16	TCP_GetUnusedPort();
 // --- Server
 tVFS_Node	*TCP_Server_Init(tInterface *Interface);
 char	*TCP_Server_ReadDir(tVFS_Node *Node, int Pos);
-tVFS_Node	*TCP_Server_FindDir(tVFS_Node *Node, char *Name);
+tVFS_Node	*TCP_Server_FindDir(tVFS_Node *Node, const char *Name);
  int	TCP_Server_IOCtl(tVFS_Node *Node, int ID, void *Data);
 void	TCP_Server_Close(tVFS_Node *Node);
 // --- Client
@@ -32,6 +39,8 @@ Uint64	TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buff
 Uint64	TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  int	TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data);
 void	TCP_Client_Close(tVFS_Node *Node);
+// --- Helpers
+ int	WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue);
 
 // === TEMPLATES ===
 tSocketFile	gTCP_ServerFile = {NULL, "tcps", TCP_Server_Init};
@@ -39,9 +48,9 @@ tSocketFile	gTCP_ClientFile = {NULL, "tcpc", TCP_Client_Init};
 
 // === GLOBALS ===
  int	giTCP_NumHalfopen = 0;
-tSpinlock	glTCP_Listeners;
+tShortSpinlock	glTCP_Listeners;
 tTCPListener	*gTCP_Listeners;
-tSpinlock	glTCP_OutbountCons;
+tShortSpinlock	glTCP_OutbountCons;
 tTCPConnection	*gTCP_OutbountCons;
 Uint32	gaTCP_PortBitmap[0x800];
  int	giTCP_NextOutPort = TCP_MIN_DYNPORT;
@@ -59,28 +68,6 @@ void TCP_Initialise()
 	IPv4_RegisterCallback(IP4PROT_TCP, TCP_GetPacket);
 }
 
-/**
- * \brief Open a connection to another host using TCP
- * \param Conn	Connection structure
- */
-void TCP_StartConnection(tTCPConnection *Conn)
-{
-	tTCPHeader	hdr;
-
-	hdr.SourcePort = Conn->LocalPort;
-	hdr.DestPort = Conn->RemotePort;
-	Conn->NextSequenceSend = rand();
-	hdr.SequenceNumber = Conn->NextSequenceSend;
-	hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
-	hdr.Flags = TCP_FLAG_SYN;
-	hdr.WindowSize = 0xFFFF;	// Max
-	hdr.Checksum = 0;	// TODO
-	hdr.UrgentPointer = 0;
-	
-	TCP_SendPacket( Conn, sizeof(tTCPHeader), &hdr );
-	return ;
-}
-
 /**
  * \brief Sends a packet from the specified connection, calculating the checksums
  * \param Conn	Connection
@@ -96,12 +83,12 @@ void TCP_SendPacket( tTCPConnection *Conn, size_t Length, tTCPHeader *Data )
 	case 4:	// Append IPv4 Pseudo Header
 		buflen = 4 + 4 + 4 + ((Length+1)&~1);
 		buf = malloc( buflen );
-		buf[0] = Conn->Interface->IP4.Address.L;
+		buf[0] = ((tIPv4*)Conn->Interface->Address)->L;
 		buf[1] = Conn->RemoteIP.v4.L;
 		buf[2] = (htons(Length)<<16) | (6<<8) | 0;
 		Data->Checksum = 0;
 		memcpy( &buf[3], Data, Length );
-		Data->Checksum = IPv4_Checksum( buf, buflen );
+		Data->Checksum = htons( IPv4_Checksum( buf, buflen ) );
 		free(buf);
 		IPv4_SendPacket(Conn->Interface, Conn->RemoteIP.v4, IP4PROT_TCP, 0, Length, Data);
 		break;
@@ -121,27 +108,30 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 	tTCPListener	*srv;
 	tTCPConnection	*conn;
 
-	Log_Log("TCP", "SourcePort = %i, DestPort = %i",
+	Log_Log("TCP", "TCP_GetPacket: SourcePort = %i, DestPort = %i",
 		ntohs(hdr->SourcePort), ntohs(hdr->DestPort));
-	Log_Log("TCP", "SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
-	Log_Log("TCP", "AcknowlegementNumber = 0x%x", ntohl(hdr->AcknowlegementNumber));
-	Log_Log("TCP", "DataOffset = %i", hdr->DataOffset >> 4);
-	Log_Log("TCP", "Flags = {");
-	Log_Log("TCP", "  CWR = %B, ECE = %B",
-		!!(hdr->Flags & TCP_FLAG_CWR), !!(hdr->Flags & TCP_FLAG_ECE));
-	Log_Log("TCP", "  URG = %B, ACK = %B",
-		!!(hdr->Flags & TCP_FLAG_URG), !!(hdr->Flags & TCP_FLAG_ACK));
-	Log_Log("TCP", "  PSH = %B, RST = %B",
-		!!(hdr->Flags & TCP_FLAG_PSH), !!(hdr->Flags & TCP_FLAG_RST));
-	Log_Log("TCP", "  SYN = %B, FIN = %B",
-		!!(hdr->Flags & TCP_FLAG_SYN), !!(hdr->Flags & TCP_FLAG_FIN));
-	Log_Log("TCP", "}");
-	Log_Log("TCP", "WindowSize = %i", htons(hdr->WindowSize));
-	Log_Log("TCP", "Checksum = 0x%x", htons(hdr->Checksum));
-	Log_Log("TCP", "UrgentPointer = 0x%x", htons(hdr->UrgentPointer));
+/*
+	Log_Log("TCP", "TCP_GetPacket: SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
+	Log_Log("TCP", "TCP_GetPacket: AcknowlegementNumber = 0x%x", ntohl(hdr->AcknowlegementNumber));
+	Log_Log("TCP", "TCP_GetPacket: DataOffset = %i", hdr->DataOffset >> 4);
+	Log_Log("TCP", "TCP_GetPacket: WindowSize = %i", htons(hdr->WindowSize));
+	Log_Log("TCP", "TCP_GetPacket: Checksum = 0x%x", htons(hdr->Checksum));
+	Log_Log("TCP", "TCP_GetPacket: UrgentPointer = 0x%x", htons(hdr->UrgentPointer));
+*/
+	Log_Log("TCP", "TCP_GetPacket: Flags = %s%s%s%s%s%s%s%s",
+		(hdr->Flags & TCP_FLAG_CWR) ? "CWR " : "",
+		(hdr->Flags & TCP_FLAG_ECE) ? "ECE " : "",
+		(hdr->Flags & TCP_FLAG_URG) ? "URG " : "",
+		(hdr->Flags & TCP_FLAG_ACK) ? "ACK " : "",
+		(hdr->Flags & TCP_FLAG_PSH) ? "PSH " : "",
+		(hdr->Flags & TCP_FLAG_RST) ? "RST " : "",
+		(hdr->Flags & TCP_FLAG_SYN) ? "SYN " : "",
+		(hdr->Flags & TCP_FLAG_FIN) ? "FIN " : ""
+		);
 
 	if( Length > (hdr->DataOffset >> 4)*4 )
 	{
+		Log_Log("TCP", "TCP_GetPacket: SequenceNumber = 0x%x", ntohl(hdr->SequenceNumber));
 		Debug_HexDump(
 			"[TCP  ] Packet Data = ",
 			(Uint8*)hdr + (hdr->DataOffset >> 4)*4,
@@ -160,17 +150,17 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 			// Check the destination port
 			if(srv->Port != htons(hdr->DestPort))	continue;
 			
-			Log_Log("TCP", "Matches server %p", srv);
+			Log_Log("TCP", "TCP_GetPacket: Matches server %p", srv);
 			// Is this in an established connection?
 			for( conn = srv->Connections; conn; conn = conn->Next )
 			{
-				Log_Log("TCP", "conn->Interface(%p) == Interface(%p)",
+				Log_Log("TCP", "TCP_GetPacket: conn->Interface(%p) == Interface(%p)",
 					conn->Interface, Interface);
 				// Check that it is coming in on the same interface
 				if(conn->Interface != Interface)	continue;
 
 				// Check Source Port
-				Log_Log("TCP", "conn->RemotePort(%i) == hdr->SourcePort(%i)",
+				Log_Log("TCP", "TCP_GetPacket: conn->RemotePort(%i) == hdr->SourcePort(%i)",
 					conn->RemotePort, ntohs(hdr->SourcePort));
 				if(conn->RemotePort != ntohs(hdr->SourcePort))	continue;
 
@@ -180,24 +170,24 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 				if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
 					continue;
 
-				Log_Log("TCP", "Matches connection %p", conn);
+				Log_Log("TCP", "TCP_GetPacket: Matches connection %p", conn);
 				// We have a response!
 				TCP_INT_HandleConnectionPacket(conn, hdr, Length);
 
 				return;
 			}
 
-			Log_Log("TCP", "Opening Connection");
+			Log_Log("TCP", "TCP_GetPacket: Opening Connection");
 			// Open a new connection (well, check that it's a SYN)
 			if(hdr->Flags != TCP_FLAG_SYN) {
-				Log_Log("TCP", "Packet is not a SYN");
+				Log_Log("TCP", "TCP_GetPacket: Packet is not a SYN");
 				return ;
 			}
 			
 			// TODO: Check for halfopen max
 			
 			conn = calloc(1, sizeof(tTCPConnection));
-			conn->State = TCP_ST_HALFOPEN;
+			conn->State = TCP_ST_SYN_RCVD;
 			conn->LocalPort = srv->Port;
 			conn->RemotePort = ntohs(hdr->SourcePort);
 			conn->Interface = Interface;
@@ -208,12 +198,15 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 			case 6:	conn->RemoteIP.v6 = *(tIPv6*)Address;	break;
 			}
 			
+			conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
+			
 			conn->NextSequenceRcv = ntohl( hdr->SequenceNumber ) + 1;
 			conn->NextSequenceSend = rand();
 			
 			// Create node
 			conn->Node.NumACLs = 1;
 			conn->Node.ACLs = &gVFS_ACL_EveryoneRW;
+			conn->Node.ImplPtr = conn;
 			conn->Node.ImplInt = srv->NextID ++;
 			conn->Node.Read = TCP_Client_Read;
 			conn->Node.Write = TCP_Client_Write;
@@ -225,7 +218,7 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 			// it, just in case
 			// Oh, wait, there is a case where a wildcard can be used
 			// (srv->Interface == NULL) so having the lock is a good idea
-			LOCK(&srv->lConnections);
+			SHORTLOCK(&srv->lConnections);
 			if( !srv->Connections )
 				srv->Connections = conn;
 			else
@@ -233,7 +226,7 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 			srv->ConnectionsTail = conn;
 			if(!srv->NewConnections)
 				srv->NewConnections = conn;
-			RELEASE(&srv->lConnections);
+			SHORTREL(&srv->lConnections);
 
 			// Send the SYN ACK
 			hdr->Flags |= TCP_FLAG_ACK;
@@ -243,7 +236,7 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 			hdr->SourcePort = htons(srv->Port);
 			hdr->DataOffset = (sizeof(tTCPHeader)/4) << 4;
 			TCP_SendPacket( conn, sizeof(tTCPHeader), hdr );
-
+			conn->NextSequenceSend ++;
 			return ;
 		}
 	}
@@ -270,7 +263,7 @@ void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffe
 		}
 	}
 	
-	Log_Log("TCP", "No Match");
+	Log_Log("TCP", "TCP_GetPacket: No Match");
 }
 
 /**
@@ -284,78 +277,291 @@ void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Head
 	tTCPStoredPacket	*pkt;
 	 int	dataLen;
 	
-	Connection->State = TCP_ST_OPEN;
-	if(Header->Flags & TCP_FLAG_SYN) {
-		Connection->NextSequenceRcv = Header->SequenceNumber + 1;
+	// Silently drop once finished
+	// TODO: Check if this needs to be here
+	if( Connection->State == TCP_ST_FINISHED ) {
+		Log_Log("TCP", "Packet ignored - connection finnished");
+		return ;
 	}
 	
-	// Get length of data
-	dataLen = Length - (Header->DataOffset>>4)*4;
-	Log_Log("TCP", "HandleConnectionPacket - dataLen = %i", dataLen);
+	// Syncronise sequence values
+	if(Header->Flags & TCP_FLAG_SYN) {
+		// TODO: What if the packet also has data?
+		Connection->NextSequenceRcv = ntohl(Header->SequenceNumber);
+	}
 	
+	// Ackowledge a sent packet
 	if(Header->Flags & TCP_FLAG_ACK) {
 		// TODO: Process an ACKed Packet
-		Log_Log("TCP", "Conn %p, Packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
+		Log_Log("TCP", "Conn %p, Sent packet 0x%x ACKed", Connection, Header->AcknowlegementNumber);
 	}
 	
-	if(dataLen == 0)	return ;
+	// Get length of data
+	dataLen = Length - (Header->DataOffset>>4)*4;
+	Log_Log("TCP", "HandleConnectionPacket - dataLen = %i", dataLen);
 	
-	// NOTES:
-	// Flags
-	//    PSH - Has Data?
-	// /NOTES
+	// 
+	// State Machine
+	//
+	switch( Connection->State )
+	{
+	// Pre-init conneciton?
+	case TCP_ST_CLOSED:
+		Log_Log("TCP", "Packets to a closed connection?!");
+		break;
 	
-	// Allocate and fill cached packet
-	pkt = malloc( dataLen + sizeof(tTCPStoredPacket) );
-	pkt->Next = NULL;
-	pkt->Sequence = ntohl(Header->SequenceNumber);
-	pkt->Length = dataLen;
-	memcpy(pkt->Data, (Uint8*)Header + (Header->DataOffset>>4)*4, dataLen);
+	// --- Init States ---
+	// SYN sent, expecting SYN-ACK Connection Opening
+	case TCP_ST_SYN_SENT:
+		if( Header->Flags & TCP_FLAG_SYN )
+		{
+			Connection->NextSequenceRcv ++;
+			Header->DestPort = Header->SourcePort;
+			Header->SourcePort = htons(Connection->LocalPort);
+			Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
+			Header->SequenceNumber = htonl(Connection->NextSequenceSend);
+			Header->WindowSize = htons(TCP_WINDOW_SIZE);
+			Header->Flags = TCP_FLAG_ACK;
+			Header->DataOffset = (sizeof(tTCPHeader)/4) << 4;
+			TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
+			
+			if( Header->Flags & TCP_FLAG_ACK )
+			{	
+				Log_Log("TCP", "ACKing SYN-ACK");
+				Connection->State = TCP_ST_OPEN;
+			}
+			else
+			{
+				Log_Log("TCP", "ACKing SYN");
+				Connection->State = TCP_ST_SYN_RCVD;
+			}
+		}
+		break;
 	
-	// Is this packet the next expected packet?
-	if( pkt->Sequence != Connection->NextSequenceRcv )
-	{
-		tTCPStoredPacket	*tmp, *prev = NULL;
+	// SYN-ACK sent, expecting ACK
+	case TCP_ST_SYN_RCVD:
+		if( Header->Flags & TCP_FLAG_ACK )
+		{
+			// TODO: Handle max half-open limit
+			Connection->State = TCP_ST_OPEN;
+			Log_Log("TCP", "Connection fully opened");
+		}
+		break;
+		
+	// --- Established State ---
+	case TCP_ST_OPEN:
+		// - Handle State changes
+		//
+		if( Header->Flags & TCP_FLAG_FIN ) {
+			Log_Log("TCP", "Conn %p closed, recieved FIN, acknowledging", Connection);
+			VFS_MarkError(&Connection->Node, 1);
+			Connection->State = TCP_ST_CLOSE_WAIT;
+			// CLOSE WAIT requires the client to close (or does it?)
+			#if 0
+			
+			#endif
+		}
+	
+		// Check for an empty packet
+		if(dataLen == 0) {
+			if( Header->Flags != TCP_FLAG_ACK )
+			{
+				Connection->NextSequenceRcv ++;	// TODO: Is this right? (empty packet counts as one byte)
+				Log_Log("TCP", "Empty Packet, inc and ACK the current sequence number");
+			}
+			else
+				Log_Log("TCP", "Empty Packet, just ACKing the current sequence number");
+			Header->DestPort = Header->SourcePort;
+			Header->SourcePort = htons(Connection->LocalPort);
+			Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
+			Header->SequenceNumber = htonl(Connection->NextSequenceSend);
+			Header->Flags |= TCP_FLAG_ACK;
+			TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
+			return ;
+		}
+		
+		// NOTES:
+		// Flags
+		//    PSH - Has Data?
+		// /NOTES
 		
-		Log_Log("TCP", "Out of sequence packet (0x%08x != 0x%08x)",
-			pkt->Sequence, Connection->NextSequenceRcv);
+		// Allocate and fill cached packet
+		pkt = malloc( sizeof(tTCPStoredPacket) + dataLen );
+		pkt->Next = NULL;
+		pkt->Sequence = ntohl(Header->SequenceNumber);
+		pkt->Length = dataLen;
+		memcpy(pkt->Data, (Uint8*)Header + (Header->DataOffset>>4)*4, dataLen);
 		
-		// No? Well, let's cache it and look at it later
-		LOCK( &Connection->lFuturePackets );
-		for(tmp = Connection->FuturePackets;
-			tmp;
-			prev = tmp, tmp = tmp->Next)
+		Log_Log("TCP", "0x%08x <= 0x%08x < 0x%08x",
+			Connection->NextSequenceRcv,
+			pkt->Sequence,
+			Connection->NextSequenceRcv + TCP_WINDOW_SIZE
+			);
+		
+		// Is this packet the next expected packet?
+		if( pkt->Sequence == Connection->NextSequenceRcv )
 		{
-			if(tmp->Sequence > pkt->Sequence)	break;
-		}
-		if(prev)
-			prev->Next = pkt;
-		else
-			Connection->FuturePackets = pkt;
-		pkt->Next = tmp;
-		RELEASE( &Connection->lFuturePackets );
-	}
-	else
-	{
-		// Ooh, Goodie! Add it to the recieved list
-		TCP_INT_AppendRecieved(Connection, pkt);
-		if(dataLen)
+			// Ooh, Goodie! Add it to the recieved list
+			TCP_INT_AppendRecieved(Connection, pkt);
+			free(pkt);
+			Log_Log("TCP", "0x%08x += %i", Connection->NextSequenceRcv, dataLen);
 			Connection->NextSequenceRcv += dataLen;
+			
+			// TODO: This should be moved out of the watcher thread,
+			// so that a single lost packet on one connection doesn't cause
+			// all connections on the interface to lag.
+			TCP_INT_UpdateRecievedFromFuture(Connection);
+		
+			// ACK Packet
+			Header->DestPort = Header->SourcePort;
+			Header->SourcePort = htons(Connection->LocalPort);
+			Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
+			Header->SequenceNumber = htonl(Connection->NextSequenceSend);
+			Header->WindowSize = htons(TCP_WINDOW_SIZE);
+			Header->Flags &= TCP_FLAG_SYN;	// Eliminate all flags save for SYN
+			Header->Flags |= TCP_FLAG_ACK;	// Add ACK
+			Log_Log("TCP", "Sending ACK for 0x%08x", Connection->NextSequenceRcv);
+			TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
+			//Connection->NextSequenceSend ++;
+		}
+		// Check if the packet is in window
+		else if( WrapBetween(Connection->NextSequenceRcv, pkt->Sequence, Connection->NextSequenceRcv+TCP_WINDOW_SIZE, 0xFFFFFFFF) )
+		{
+			tTCPStoredPacket	*tmp, *prev = NULL;
+			
+			Log_Log("TCP", "We missed a packet, caching",
+				pkt->Sequence, Connection->NextSequenceRcv);
+			
+			// No? Well, let's cache it and look at it later
+			SHORTLOCK( &Connection->lFuturePackets );
+			for(tmp = Connection->FuturePackets;
+				tmp;
+				prev = tmp, tmp = tmp->Next)
+			{
+				if(tmp->Sequence >= pkt->Sequence)	break;
+			}
+			
+			// Add if before first, or sequences don't match 
+			if( !tmp || tmp->Sequence != pkt->Sequence )
+			{
+				if(prev)
+					prev->Next = pkt;
+				else
+					Connection->FuturePackets = pkt;
+				pkt->Next = tmp;
+			}
+			// Replace if larger
+			else if(pkt->Length > tmp->Length)
+			{
+				if(prev)
+					prev->Next = pkt;
+				pkt->Next = tmp->Next;
+				free(tmp);
+			}
+			else
+			{
+				free(pkt);
+			}
+			SHORTREL( &Connection->lFuturePackets );
+		}
+		// Badly out of sequence packet
 		else
-			Connection->NextSequenceRcv += 1;
+		{
+			Log_Log("TCP", "Fully out of sequence packet (0x%08x not between 0x%08x and 0x%08x), dropped",
+				pkt->Sequence, Connection->NextSequenceRcv, Connection->NextSequenceRcv+TCP_WINDOW_SIZE);
+			free(pkt);
+			// TODO: Spec says we should send an empty ACK with the current state
+		}
+		break;
+	
+	// --- Remote close states
+	case TCP_ST_CLOSE_WAIT:
+		
+		// Ignore everything, CLOSE_WAIT is terminated by the client
+		Log_Debug("TCP", "CLOSE WAIT - Ignoring packets");
+		
+		break;
+	
+	// LAST-ACK - Waiting for the ACK of FIN (from CLOSE WAIT)
+	case TCP_ST_LAST_ACK:
+		if( Header->Flags & TCP_FLAG_ACK )
+		{
+			Connection->State = TCP_ST_FINISHED;	// Connection completed
+			Log_Log("TCP", "LAST-ACK to CLOSED - Connection remote closed");
+			// TODO: Destrory the TCB
+		}
+		break;
+	
+	// --- Local close States
+	case TCP_ST_FIN_WAIT1:
+		if( Header->Flags & TCP_FLAG_FIN )
+		{
+			Connection->State = TCP_ST_CLOSING;
+			Log_Debug("TCP", "Conn %p closed, sent FIN and recieved FIN", Connection);
+			VFS_MarkError(&Connection->Node, 1);
+			
+			// ACK Packet
+			Header->DestPort = Header->SourcePort;
+			Header->SourcePort = htons(Connection->LocalPort);
+			Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
+			Header->SequenceNumber = htonl(Connection->NextSequenceSend);
+			Header->WindowSize = htons(TCP_WINDOW_SIZE);
+			Header->Flags = TCP_FLAG_ACK;
+			TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
+			break ;
+		}
 		
-		// TODO: This should be moved out of the watcher thread,
-		// so that a single lost packet on one connection doesn't cause
-		// all connections on the interface to lag.
-		TCP_INT_UpdateRecievedFromFuture(Connection);
-	
-		// TODO: Check ACK code validity
-		Header->AcknowlegementNumber = ntohl(pkt->Sequence) + dataLen;
-		Header->SequenceNumber = ntohl(Connection->NextSequenceSend);
-		Header->Flags &= TCP_FLAG_SYN;
-		Header->Flags = TCP_FLAG_ACK;
-		TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
+		// TODO: Make sure that the packet is actually ACKing the FIN
+		if( Header->Flags & TCP_FLAG_ACK )
+		{
+			Connection->State = TCP_ST_FIN_WAIT2;
+			Log_Debug("TCP", "Conn %p closed, sent FIN ACKed", Connection);
+			VFS_MarkError(&Connection->Node, 1);
+			return ;
+		}
+		break;
+	
+	case TCP_ST_FIN_WAIT2:
+		if( Header->Flags & TCP_FLAG_FIN )
+		{
+			Connection->State = TCP_ST_TIME_WAIT;
+			Log_Debug("TCP", "FIN sent and recieved, ACKing and going into TIME WAIT %p FINWAIT-2 -> TIME WAIT", Connection);
+			// Send ACK
+			Header->DestPort = Header->SourcePort;
+			Header->SourcePort = htons(Connection->LocalPort);
+			Header->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
+			Header->SequenceNumber = htonl(Connection->NextSequenceSend);
+			Header->WindowSize = htons(TCP_WINDOW_SIZE);
+			Header->Flags = TCP_FLAG_ACK;
+			TCP_SendPacket( Connection, sizeof(tTCPHeader), Header );
+		}
+		break;
+	
+	case TCP_ST_CLOSING:
+		// TODO: Make sure that the packet is actually ACKing the FIN
+		if( Header->Flags & TCP_FLAG_ACK )
+		{
+			Connection->State = TCP_ST_TIME_WAIT;
+			Log_Debug("TCP", "Conn %p CLOSING -> TIME WAIT", Connection);
+			VFS_MarkError(&Connection->Node, 1);
+			return ;
+		}
+		break;
+	
+	// --- Closed (or near closed) states) ---
+	case TCP_ST_TIME_WAIT:
+		Log_Log("TCP", "Packets on Time-Wait, ignored");
+		break;
+	
+	case TCP_ST_FINISHED:
+		Log_Log("TCP", "Packets when CLOSED, ignoring");
+		break;
+	
+	//default:
+	//	Log_Warning("TCP", "Unhandled TCP state %i", Connection->State);
+	//	break;
 	}
+	
 }
 
 /**
@@ -365,18 +571,23 @@ void TCP_INT_HandleConnectionPacket(tTCPConnection *Connection, tTCPHeader *Head
  */
 void TCP_INT_AppendRecieved(tTCPConnection *Connection, tTCPStoredPacket *Pkt)
 {
-	LOCK( &Connection->lRecievedPackets );
-	if(Connection->RecievedPackets)
-	{
-		Connection->RecievedPacketsTail->Next = Pkt;
-		Connection->RecievedPacketsTail = Pkt;
-	}
-	else
+	Mutex_Acquire( &Connection->lRecievedPackets );
+	if(Connection->RecievedBuffer->Length + Pkt->Length > Connection->RecievedBuffer->Space )
 	{
-		Connection->RecievedPackets = Pkt;
-		Connection->RecievedPacketsTail = Pkt;
+		Log_Error("TCP", "Buffer filled, packet dropped (%s)",
+		//	TCP_INT_DumpConnection(Connection)
+			""
+			);
+		return ;
 	}
-	RELEASE( &Connection->lRecievedPackets );
+	
+	RingBuffer_Write( Connection->RecievedBuffer, Pkt->Data, Pkt->Length );
+
+	#if USE_SELECT
+	VFS_MarkAvaliable(&Connection->Node, 1);
+	#endif
+	
+	Mutex_Release( &Connection->lRecievedPackets );
 }
 
 /**
@@ -389,34 +600,40 @@ void TCP_INT_AppendRecieved(tTCPConnection *Connection, tTCPStoredPacket *Pkt)
  */
 void TCP_INT_UpdateRecievedFromFuture(tTCPConnection *Connection)
 {
-	tTCPStoredPacket	*pkt, *prev;
+	tTCPStoredPacket	*pkt;
 	for(;;)
 	{
-		prev = NULL;
-		// Look for the next expected packet in the cache.
-		LOCK( &Connection->lFuturePackets );
-		for(pkt = Connection->FuturePackets;
-			pkt && pkt->Sequence < Connection->NextSequenceRcv;
-			prev = pkt, pkt = pkt->Next);
+		SHORTLOCK( &Connection->lFuturePackets );
+		
+		// Clear out duplicates from cache
+		// - If a packet has just been recieved, and it is expected, then
+		//   (since NextSequenceRcv = rcvd->Sequence + rcvd->Length) all
+		//   packets in cache that are smaller than the next expected
+		//   are now defunct.
+		pkt = Connection->FuturePackets;
+		while(pkt && pkt->Sequence < Connection->NextSequenceRcv)
+		{
+			tTCPStoredPacket	*next = pkt->Next;
+			free(pkt);
+			pkt = next;
+		}
 		
-		// If we can't find the expected next packet, stop looking
+		// If there's no packets left in cache, stop looking
 		if(!pkt || pkt->Sequence > Connection->NextSequenceRcv) {
-			RELEASE( &Connection->lFuturePackets );
+			SHORTREL( &Connection->lFuturePackets );
 			return;
 		}
 		
 		// Delete packet from future list
-		if(prev)
-			prev->Next = pkt->Next;
-		else
-			Connection->FuturePackets = pkt->Next;
+		Connection->FuturePackets = pkt->Next;
 		
 		// Release list
-		RELEASE( &Connection->lFuturePackets );
+		SHORTREL( &Connection->lFuturePackets );
 		
 		// Looks like we found one
 		TCP_INT_AppendRecieved(Connection, pkt);
-		Connection->NextSequenceRcv ++;
+		Connection->NextSequenceRcv += pkt->Length;
+		free(pkt);
 	}
 }
 
@@ -484,8 +701,6 @@ tVFS_Node *TCP_Server_Init(tInterface *Interface)
 	
 	srv = malloc( sizeof(tTCPListener) );
 
-	Log_Debug("TCP", "srv = %p", srv);
-
 	if( srv == NULL ) {
 		Log_Warning("TCP", "malloc failed for listener (%i) bytes", sizeof(tTCPListener));
 		return NULL;
@@ -495,6 +710,8 @@ tVFS_Node *TCP_Server_Init(tInterface *Interface)
 	srv->Port = 0;
 	srv->NextID = 0;
 	srv->Connections = NULL;
+	srv->ConnectionsTail = NULL;
+	srv->NewConnections = NULL;
 	srv->Next = NULL;
 	srv->Node.Flags = VFS_FFLAG_DIRECTORY;
 	srv->Node.Size = -1;
@@ -506,10 +723,10 @@ tVFS_Node *TCP_Server_Init(tInterface *Interface)
 	srv->Node.IOCtl = TCP_Server_IOCtl;
 	srv->Node.Close = TCP_Server_Close;
 
-	LOCK(&glTCP_Listeners);
+	SHORTLOCK(&glTCP_Listeners);
 	srv->Next = gTCP_Listeners;
 	gTCP_Listeners = srv;
-	RELEASE(&glTCP_Listeners);
+	SHORTREL(&glTCP_Listeners);
 
 	return &srv->Node;
 }
@@ -525,28 +742,36 @@ char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
 	tTCPListener	*srv = Node->ImplPtr;
 	tTCPConnection	*conn;
 	char	*ret;
+	
+	ENTER("pNode iPos", Node, Pos);
 
 	Log_Log("TCP", "Thread %i waiting for a connection", Threads_GetTID());
 	for(;;)
 	{
-		LOCK( &srv->lConnections );
+		SHORTLOCK( &srv->lConnections );
 		if( srv->NewConnections != NULL )	break;
-		RELEASE( &srv->lConnections );
-		Threads_Yield();
+		SHORTREL( &srv->lConnections );
+		Threads_Yield();	// TODO: Sleep until poked
 		continue;
 	}
 	
 
 	// Increment the new list (the current connection is still on the 
-	// normal list
+	// normal list)
 	conn = srv->NewConnections;
 	srv->NewConnections = conn->Next;
 	
-	RELEASE( &srv->lConnections );
+	SHORTREL( &srv->lConnections );
+	
+	LOG("conn = %p", conn);
+	LOG("srv->Connections = %p", srv->Connections);
+	LOG("srv->NewConnections = %p", srv->NewConnections);
+	LOG("srv->ConnectionsTail = %p", srv->ConnectionsTail);
 
 	ret = malloc(9);
-	itoa(ret, Node->ImplInt, 16, 8, '0');
-	Log("TCP_Server_ReadDir: RETURN '%s'", ret);
+	itoa(ret, conn->Node.ImplInt, 16, 8, '0');
+	Log_Log("TCP", "Thread %i got '%s'", Threads_GetTID(), ret);
+	LEAVE('s', ret);
 	return ret;
 }
 
@@ -555,28 +780,47 @@ char *TCP_Server_ReadDir(tVFS_Node *Node, int Pos)
  * \param Node	Server node
  * \param Name	Hexadecimal ID of the node
  */
-tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, char *Name)
+tVFS_Node *TCP_Server_FindDir(tVFS_Node *Node, const char *Name)
 {
 	tTCPConnection	*conn;
 	tTCPListener	*srv = Node->ImplPtr;
 	char	tmp[9];
 	 int	id = atoi(Name);
 	
+	ENTER("pNode sName", Node, Name);
+	
 	// Sanity Check
 	itoa(tmp, id, 16, 8, '0');
-	if(strcmp(tmp, Name) != 0)	return NULL;
+	if(strcmp(tmp, Name) != 0) {
+		LOG("'%s' != '%s' (%08x)", Name, tmp, id);
+		LEAVE('n');
+		return NULL;
+	}
+	
+	Log_Debug("TCP", "srv->Connections = %p", srv->Connections);
+	Log_Debug("TCP", "srv->NewConnections = %p", srv->NewConnections);
+	Log_Debug("TCP", "srv->ConnectionsTail = %p", srv->ConnectionsTail);
 	
 	// Search
-	LOCK( &srv->lConnections );
+	SHORTLOCK( &srv->lConnections );
 	for(conn = srv->Connections;
-		conn && conn->Node.ImplInt != id;
-		conn = conn->Next);
-	RELEASE( &srv->lConnections );
+		conn;
+		conn = conn->Next)
+	{
+		LOG("conn->Node.ImplInt = %i", conn->Node.ImplInt);
+		if(conn->Node.ImplInt == id)	break;
+	}
+	SHORTREL( &srv->lConnections );
 	
 	// If not found, ret NULL
-	if(!conn)	return NULL;
+	if(!conn) {
+		LOG("Connection %i not found", id);
+		LEAVE('n');
+		return NULL;
+	}
 	
 	// Return node
+	LEAVE('p', &conn->Node);
 	return &conn->Node;
 }
 
@@ -636,8 +880,8 @@ tVFS_Node *TCP_Client_Init(tInterface *Interface)
 
 	conn->State = TCP_ST_CLOSED;
 	conn->Interface = Interface;
-	conn->LocalPort = 0;
-	conn->RemotePort = 0;
+	conn->LocalPort = -1;
+	conn->RemotePort = -1;
 	memset( &conn->RemoteIP, 0, sizeof(conn->RemoteIP) );
 
 	conn->Node.ImplPtr = conn;
@@ -648,10 +892,12 @@ tVFS_Node *TCP_Client_Init(tInterface *Interface)
 	conn->Node.IOCtl = TCP_Client_IOCtl;
 	conn->Node.Close = TCP_Client_Close;
 
-	LOCK(&glTCP_OutbountCons);
+	conn->RecievedBuffer = RingBuffer_Create( TCP_RECIEVE_BUFFER_SIZE );
+
+	SHORTLOCK(&glTCP_OutbountCons);
 	conn->Next = gTCP_OutbountCons;
 	gTCP_OutbountCons = conn;
-	RELEASE(&glTCP_OutbountCons);
+	SHORTREL(&glTCP_OutbountCons);
 
 	return &conn->Node;
 }
@@ -664,46 +910,136 @@ tVFS_Node *TCP_Client_Init(tInterface *Interface)
 Uint64 TCP_Client_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 {
 	tTCPConnection	*conn = Node->ImplPtr;
-	tTCPStoredPacket	*pkt;
+	size_t	len;
 	
-	Log("TCP_Client_Read: (Length=%i)", Length);
+	ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
+	LOG("conn = %p {State:%i}", conn, conn->State);
 	
 	// Check if connection is open
-	if( conn->State != TCP_ST_OPEN )	return 0;
+	while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
+		Threads_Yield();
 	
-	// Poll packets
-	for(;;)
-	{		
-		// Lock list and check if there is a packet
-		LOCK( &conn->lRecievedPackets );
-		if( conn->RecievedPackets == NULL ) {
-			// If not, release the lock, yield and try again
-			RELEASE( &conn->lRecievedPackets );
-			Threads_Yield();
-			continue;
-		}
-		
-		// Get packet pointer
-		pkt = conn->RecievedPackets;
-		conn->RecievedPackets = pkt->Next;
-		// Release the lock (we don't need it any more)
-		RELEASE( &conn->lRecievedPackets );
-		
-		Log("TCP_Client_Read: pkt->Length = %i", pkt->Length);
+	if( conn->State != TCP_ST_OPEN )
+	{
+		Mutex_Acquire( &conn->lRecievedPackets );
+		len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
+		Mutex_Release( &conn->lRecievedPackets );
 		
-		// Copy Data
-		if(Length > pkt->Length)	Length = pkt->Length;
-		memcpy(Buffer, pkt->Data, Length);
+		if( len == 0 ) {
+			VFS_MarkAvaliable(Node, 0);
+			LEAVE('i', -1);
+			return -1;
+		}
 		
-		// Free packet and return
-		free(pkt);
-		return Length;
+		LEAVE('i', len);
+		return len;
+	}
+	
+	// Wait
+	VFS_SelectNode(Node, VFS_SELECT_READ, NULL, "TCP_Client_Read");
+	
+	// Lock list and read
+	Mutex_Acquire( &conn->lRecievedPackets );
+	
+	// Attempt to read all `Length` bytes
+	len = RingBuffer_Read( Buffer, conn->RecievedBuffer, Length );
+	
+	if( len == 0 || conn->RecievedBuffer->Length == 0 ) {
+		LOG("Marking as none avaliable (len = %i)", len);
+		VFS_MarkAvaliable(Node, 0);
 	}
+		
+	// Release the lock (we don't need it any more)
+	Mutex_Release( &conn->lRecievedPackets );
+
+	LEAVE('i', len);
+	return len;
 }
 
+/**
+ * \brief Send a data packet on a connection
+ */
+void TCP_INT_SendDataPacket(tTCPConnection *Connection, size_t Length, void *Data)
+{
+	char	buf[sizeof(tTCPHeader)+Length];
+	tTCPHeader	*packet = (void*)buf;
+	
+	packet->SourcePort = htons(Connection->LocalPort);
+	packet->DestPort = htons(Connection->RemotePort);
+	packet->DataOffset = (sizeof(tTCPHeader)/4)*16;
+	packet->WindowSize = TCP_WINDOW_SIZE;
+	
+	packet->AcknowlegementNumber = htonl(Connection->NextSequenceRcv);
+	packet->SequenceNumber = htonl(Connection->NextSequenceSend);
+	packet->Flags = TCP_FLAG_PSH|TCP_FLAG_ACK;	// Hey, ACK if you can!
+	
+	memcpy(packet->Options, Data, Length);
+	
+	Log_Debug("TCP", "Send sequence 0x%08x", Connection->NextSequenceSend);
+	Debug_HexDump("[TCP     ] TCP_INT_SendDataPacket: Data = ",
+		Data, Length);
+	
+	TCP_SendPacket( Connection, sizeof(tTCPHeader)+Length, packet );
+	
+	Connection->NextSequenceSend += Length;
+}
+
+/**
+ * \brief Send some bytes on a connection
+ */
 Uint64 TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 {
-	return 0;
+	tTCPConnection	*conn = Node->ImplPtr;
+	size_t	rem = Length;
+	
+	ENTER("pNode XOffset XLength pBuffer", Node, Offset, Length, Buffer);
+	
+	// Check if connection is open
+	while( conn->State == TCP_ST_SYN_RCVD || conn->State == TCP_ST_SYN_SENT )
+		Threads_Yield();
+	
+	if( conn->State != TCP_ST_OPEN ) {
+		VFS_MarkError(Node, 1);
+		LEAVE('i', -1);
+		return -1;
+	}
+	
+	while( rem > TCP_MAX_PACKET_SIZE )
+	{
+		TCP_INT_SendDataPacket(conn, TCP_MAX_PACKET_SIZE, Buffer);
+		Buffer += TCP_MAX_PACKET_SIZE;
+	}
+	
+	TCP_INT_SendDataPacket(conn, rem, Buffer);
+	
+	LEAVE('i', Length);
+	return Length;
+}
+
+/**
+ * \brief Open a connection to another host using TCP
+ * \param Conn	Connection structure
+ */
+void TCP_StartConnection(tTCPConnection *Conn)
+{
+	tTCPHeader	hdr = {0};
+
+	Conn->State = TCP_ST_SYN_SENT;
+
+	hdr.SourcePort = htons(Conn->LocalPort);
+	hdr.DestPort = htons(Conn->RemotePort);
+	Conn->NextSequenceSend = rand();
+	hdr.SequenceNumber = htonl(Conn->NextSequenceSend);
+	hdr.DataOffset = (sizeof(tTCPHeader)/4) << 4;
+	hdr.Flags = TCP_FLAG_SYN;
+	hdr.WindowSize = htons(TCP_WINDOW_SIZE);	// Max
+	hdr.Checksum = 0;	// TODO
+	
+	TCP_SendPacket( Conn, sizeof(tTCPHeader), &hdr );
+	
+	Conn->NextSequenceSend ++;
+	Conn->State = TCP_ST_SYN_SENT;
+	return ;
 }
 
 /**
@@ -712,53 +1048,59 @@ Uint64 TCP_Client_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buf
 int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
 {
 	tTCPConnection	*conn = Node->ImplPtr;
+	
+	ENTER("pNode iID pData", Node, ID, Data);
 
 	switch(ID)
 	{
 	case 4:	// Get/Set local port
 		if(!Data)
-			return conn->LocalPort;
+			LEAVE_RET('i', conn->LocalPort);
 		if(conn->State != TCP_ST_CLOSED)
-			return -1;
+			LEAVE_RET('i', -1);
 		if(!CheckMem(Data, sizeof(Uint16)))
-			return -1;
+			LEAVE_RET('i', -1);
 
 		if(Threads_GetUID() != 0 && *(Uint16*)Data < 1024)
-			return -1;
+			LEAVE_RET('i', -1);
 
 		conn->LocalPort = *(Uint16*)Data;
-		return 0;
+		LEAVE_RET('i', conn->LocalPort);
 
 	case 5:	// Get/Set remote port
-		if(!Data)	return conn->RemotePort;
-		if(conn->State != TCP_ST_CLOSED)	return -1;
-		if(!CheckMem(Data, sizeof(Uint16)))	return -1;
+		if(!Data)	LEAVE_RET('i', conn->RemotePort);
+		if(conn->State != TCP_ST_CLOSED)	LEAVE_RET('i', -1);
+		if(!CheckMem(Data, sizeof(Uint16)))	LEAVE_RET('i', -1);
 		conn->RemotePort = *(Uint16*)Data;
-		return 0;
+		LEAVE_RET('i', conn->RemotePort);
 
 	case 6:	// Set Remote IP
 		if( conn->State != TCP_ST_CLOSED )
-			return -1;
+			LEAVE_RET('i', -1);
 		if( conn->Interface->Type == 4 )
 		{
-			if(!CheckMem(Data, sizeof(tIPv4)))	return -1;
+			if(!CheckMem(Data, sizeof(tIPv4)))	LEAVE_RET('i', -1);
 			conn->RemoteIP.v4 = *(tIPv4*)Data;
 		}
 		else if( conn->Interface->Type == 6 )
 		{
-			if(!CheckMem(Data, sizeof(tIPv6)))	return -1;
+			if(!CheckMem(Data, sizeof(tIPv6)))	LEAVE_RET('i', -1);
 			conn->RemoteIP.v6 = *(tIPv6*)Data;
 		}
-		return 0;
+		LEAVE_RET('i', 0);
 
 	case 7:	// Connect
-		if(conn->LocalPort == -1)
+		if(conn->LocalPort == 0xFFFF)
 			conn->LocalPort = TCP_GetUnusedPort();
 		if(conn->RemotePort == -1)
-			return 0;
+			LEAVE_RET('i', 0);
 
 		TCP_StartConnection(conn);
-		return 1;
+		LEAVE_RET('i', 1);
+	
+	// Get recieve buffer length
+	case 8:
+		LEAVE_RET('i', conn->RecievedBuffer->Length);
 	}
 
 	return 0;
@@ -766,5 +1108,78 @@ int TCP_Client_IOCtl(tVFS_Node *Node, int ID, void *Data)
 
 void TCP_Client_Close(tVFS_Node *Node)
 {
-	free(Node->ImplPtr);
+	tTCPConnection	*conn = Node->ImplPtr;
+	tTCPHeader	packet;
+	
+	ENTER("pNode", Node);
+	
+	if( conn->State == TCP_ST_CLOSE_WAIT || conn->State == TCP_ST_OPEN )
+	{
+		packet.SourcePort = htons(conn->LocalPort);
+		packet.DestPort = htons(conn->RemotePort);
+		packet.DataOffset = (sizeof(tTCPHeader)/4)*16;
+		packet.WindowSize = TCP_WINDOW_SIZE;
+		
+		packet.AcknowlegementNumber = 0;
+		packet.SequenceNumber = htonl(conn->NextSequenceSend);
+		packet.Flags = TCP_FLAG_FIN|TCP_FLAG_ACK;
+		
+		TCP_SendPacket( conn, sizeof(tTCPHeader), &packet );
+	}
+	
+	switch( conn->State )
+	{
+	case TCP_ST_CLOSE_WAIT:
+		conn->State = TCP_ST_CLOSED;
+		break;
+	case TCP_ST_OPEN:
+		conn->State = TCP_ST_FIN_WAIT1;
+		while( conn->State == TCP_ST_FIN_WAIT1 )	Threads_Yield();
+		break;
+	default:
+		Log_Warning("TCP", "Unhandled connection state in TCP_Client_Close");
+		break;
+	}
+	
+	free(conn);
+	
+	LEAVE('-');
+}
+
+/**
+ * \brief Checks if a value is between two others (after taking into account wrapping)
+ */
+int WrapBetween(Uint32 Lower, Uint32 Value, Uint32 Higher, Uint32 MaxValue)
+{
+	if( MaxValue < 0xFFFFFFFF )
+	{
+		Lower %= MaxValue + 1;
+		Value %= MaxValue + 1;
+		Higher %= MaxValue + 1;
+	}
+	
+	// Simple Case, no wrap ?
+	//       Lower Value Higher
+	// | ... + ... + ... + ... |
+
+	if( Lower < Higher ) {
+		return Lower < Value && Value < Higher;
+	}
+	// Higher has wrapped below lower
+	
+	// Value > Lower ?
+	//       Higher Lower Value
+	// | ... +  ... + ... + ... |
+	if( Value > Lower ) {
+		return 1;
+	}
+	
+	// Value < Higher ?
+	//       Value Higher Lower
+	// | ... + ... +  ... + ... |
+	if( Value < Higher ) {
+		return 1;
+	}
+	
+	return 0;
 }