/*****************************************************************************
* nettcp.h - Network Transmission Control Protocol header file.
*
* Copyright (c) 1998 Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 98-02-02 Guy Lancaster <glanca@gesn.com>, Global Election Systems Inc.
*	Original based on ka9q and BSD codes.
* 2001-05-18 Mads Christiansen <mads@mogi.dk>, Partner Voxtream 
*       Added support for running uC/IP in a single proces and on ethernet.
******************************************************************************
* THEORY OF OPERATION
*
*****************************************************************************/

#ifndef NETTCP_H
#define NETTCP_H


/*************************
*** PUBLIC DEFINITIONS ***
**************************/
/*
 * TCP configuration. 
 */
#if ETHER_SUPPORT
#define	TCP_DEFMSS	1460		/* Default maximum TCP segment size. */
#define TCP_MINMSS  256 		/* Minimum MSS - interfaces must handle. I'm not sure about this! */
#define	TCP_DEFWND	1460		/* Default receiver window. 
                               Changed this to 1460 bytes (instead of 512) for ethernet.
                               This will allow use of a whole ethernet packet.
                               You will achieve much better performance on file transfers if this 
                               was set higher, but this might be overkill for an embedded system.
                               For better perfomance set this to 4096 and allocate more memory for the
                               buffer system. */
#endif

#if PPP_SUPPORT
#define	TCP_DEFMSS	256			/* Default maximum TCP segment size. */
#define TCP_MINMSS 256			/* Minimum MSS - interfaces must handle 296 - 40. */
#define	TCP_DEFWND	512			/* Default receiver window. */
#endif

#define	TCP_DEFRTT	500			/* Initial guess at round trip time (ms) */
#define TCP_ISSTHRESH 64*KILOBYTE-1	/* Initial slow start threshhold. */
#define TCP_DEFPORT 5000		/* Initial local port. */

#define TCP_MAXQUEUE 8			/* Maximum packets to allow in queue. */
#define TCP_MINSEG 80			/* Minimum sized segment for modified Nagle. */


/*
 * TCP Error codes.
 */
#define TCPERR_EOF -1			/* End of data. */
#define TCPERR_ALLOC -2			/* Unable to allocate a control block. */
#define TCPERR_PARAM -3			/* Invalid parameters. */
#define TCPERR_INVADDR -4		/* Invalid address. */
#define TCPERR_CONFIG -5		/* Invalid configuration. */
#define TCPERR_CONNECT -6		/* No connection. */
#define TCPERR_RESET -7			/* Connection reset received. */
#define TCPERR_TIMEOUT -8		/* Timeout on transmission. */
#define TCPERR_NETWORK -9		/* Network error - unreachable? */
#define TCPERR_PREC -10			/* IP Precedence error. */
#define TCPERR_PROTOCOL -11		/* Protocol error. */

/*
 * TCP IOCTL commands.
 */
/* Get an up status value - non-zero if connection is up. */
#define TCPCTLG_UPSTATUS 100
/* Get the bytes in the receive queue. */
#define TCPCTLG_RCVCNT 101
/*
 * Get/set the keepalive value in seconds - 0 for none.  The argument must
 * point to an int.  Note that if the connection is already established,
 * the keep alive timer won't be started until after the next transmission.
 */
#define TCPCTLG_KEEPALIVE 102
#define TCPCTLS_KEEPALIVE 103
/* Get/set the trace level.  For debugging use only. */
#define TCPCTLG_TRACELEVEL 104
#define TCPCTLS_TRACELEVEL 105


/*
 * TCP port numbers.
 */
#define	TCPPORT_ECHO		7		/* Echo data port */
#define	TCPPORT_DISCARD		9		/* Discard data port */
#define TCPPORT_TELNET		23		/* Telnet port */
#define TCPPORT_FINGER		79		/* Finger port */


/*
 * TCP option codes and lengths. 
 */
#define	TCPOPT_EOL				0
#define	TCPOPT_NOP				1
#define	TCPOPT_MAXSEG			2
#define TCPOLEN_MAXSEG			4
#define TCPOPT_WINDOW			3
#define TCPOLEN_WINDOW			3
#define TCPOPT_TIMESTAMP		8
#define TCPOLEN_TIMESTAMP		10


/************************
*** PUBLIC DATA TYPES ***
*************************/
typedef u_int32_t TCPAddress;
typedef u_int16_t TCPPort;

/* TCP statistics counters */
typedef struct TCPStats_s {
	DiagStat headLine;		/* Head line for display. */
	DiagStat curFree;		/* Current number of free control blocks. */
	DiagStat minFree;		/* Minimum number of free CB's during operation. */
	DiagStat runt;			/* Smaller than minimum size */
	DiagStat checksum;		/* TCP header checksum errors */
	DiagStat conout;		/* Outgoing connection attempts */
	DiagStat conin;			/* Incoming connection attempts */
	DiagStat resetOut;		/* Resets generated */
	DiagStat resetIn;		/* Resets received */
	DiagStat endRec;
} TCPStats;

/*
 * TCP connection states.
 */
typedef enum {
	CLOSED = 0,		/* Must be 0 */
	LISTEN = 1,
	SYN_SENT= 2,
	SYN_RECEIVED = 3,
	ESTABLISHED = 4,
	FINWAIT1 = 5,
	FINWAIT2 = 6,
	CLOSE_WAIT = 7,
	CLOSING	= 8,
	LAST_ACK = 9,
	TIME_WAIT = 10
} TCPState;


/* TCB state labels (for debugging.) */
extern char *tcbStates[];


/*****************************
*** PUBLIC DATA STRUCTURES ***
*****************************/
//extern const DevDef tcpdef;		/* The TCP connection interface. */

#if STATS_SUPPORT > 0
extern TCPStats tcpStats;
#endif


/***********************
*** PUBLIC FUNCTIONS ***
************************/

/*
 * Initialize the TCP subsystem.
 */
void tcpInit(void);

/* 
 * Return a new TCP descriptor on success or an error code (negative) on 
 * failure. 
 */

#if ONETASK_SUPPORT > 0
  int tcpOpen(
    void (*receiveEvent)(int, u_long),               
    void (*transmitEvent)(int, u_long),              
    void (*stateEvent)(int, TCPState, TCPState)      
  );
#else
int tcpOpen(void);
#endif

/* 
 * Close a TCP connection and release the descriptor. 
 * Any outstanding packets in the queues are dropped.
 * Return 0 on success, an error code on failure. 
 */
int tcpClose(u_int td);

/*
 * Bind an IP address and port number in the sockaddr structure as our
 * address on a TCP connection.
 * Note: Currently the IP address must equal ourAddress since that is all
 * that ipDispatch() will recognize.
 * Return 0 on success, an error code on failure.
 */
int tcpBind(u_int td, struct sockaddr_in *myAddr);

/*
 * Establish a connection with a remote host.  Unless tcpBind() has been called,
 * the local IP address and port number are generated automatically.  
 * tcpConnect() blocks until the connection request either succeeds or fails.
 * tcpConnectMs() blocks up to the specified number of milliseconds.  
 * tcpConnectJiffy() blocks up to the specified number of Jiffies (OS timer 
 * ticks).
 * Return 0 on success, an error code on failure.
 */
#define tcpConnect(td, remoteAddr, tos) \
	tcpConnectJiffy(td, remoteAddr, tos, 0)
#define tcpConnectMs(td, remoteAddr, tos, t) \
	tcpConnectJiffy(td, remoteAddr, tos, (t + MSPERJIFFY - 1) / MSPERJIFFY)
int tcpConnectJiffy(u_int td, const struct sockaddr_in *remoteAddr, u_char tos, u_int timeout);

/*
 * tcpDisconnect - Tell the peer that we will not be sending any more data
 * (i.e. perform a half close on a connection).  tcpRead() will then
 * wait until the connection closes.
 * Return 0 when the peer acknowledges our message or an error code on
 * failure.
 */
int tcpDisconnect(u_int td);

/*
 * Set the number of backLog connections which will be queued to be picked up
 * by calls to accept.  Without this call, no connection will be opened until
 * tcpAccept() or tcpConnect() is called.
 * Return 0 on success, an error code on failure.
 */
int tcpListen(u_int td, int backLog);

/*
 * Pick up a connection opened by a remote host.  tcpBind() must be used to
 * specify the local address and port number for the connection.  Unless 
 * tcpListen() has been called, no connection will be accepted until this
 * is called.
 * Return a new TCP descriptor for the opened connection on success, an
 * error code on failure.
 */
#define tcpAccept(td, peerAddr) \
	tcpAcceptJiffy(td, peerAddr, 0)
#define tcpAcceptMs(td, peerAddr, t) \
	tcpReadJiffy(td, peerAddr, (t + MSPERJIFFY - 1) / MSPERJIFFY)
int tcpAcceptJiffy(u_int td, struct sockaddr_in *peerAddr, u_int timeout);

/*
 * Read from a connected TCP connection.  tcpRead() blocks until at least
 * one character is read or an error occurs.  tcpReadMs() blocks at most
 * the specified number of milliseconds.  tcpReadJiffy() blocks at most
 * the specified number of Jiffies (OS timer ticks).
 * Return the number of bytes read on success or timeout, an error code on
 * failure. 
 */
int tcpRead(u_int td, void *s, u_int len);
#define tcpReadMs(td, s, len, t) \
	tcpReadJiffy(td, s, len, (t + MSPERJIFFY - 1) / MSPERJIFFY)
int tcpReadJiffy(u_int td, void *s, u_int len, u_int timeout);

/*
 * Write to a connected TCP connection.  tcpWrite() blocks until all bytes
 * have been queued or an error occurs.  tcpWriteMs() blocks at most the
 * specified number of milliseconds.  tcpWriteJiffy() blocks at most the
 * specified number of Jiffies (OS timer ticks).
 * Return the number of bytes written on success or timeout, an error code
 * on failure.
 */
int tcpWrite(u_int td, const void *s, u_int n);
#define tcpWriteMs(td, s, n, t) \
	tcpWriteJiffy(td, s, n, (t + MSPERJIFFY - 1) / MSPERJIFFY)
int tcpWriteJiffy(u_int td, const void *s, u_int n, u_int timeout);

/*
 * tcpWait - Wait for the connection to be closed.  Normally this will be
 * done after a disconnect before trying to reuse the TCB.  This will fail
 * if the connection is not closing.
 * Returns 0 on success or an error code if the connection is not
 * closing.
 */
int tcpWait(u_int td);

/* 
 * Receive an incoming datagram.  This is called from IP.
 */
void tcpInput(NBuf *inBuf, u_int ipHeadLen);

/* 
 * Get and set parameters for the given connection.
 * Return 0 on success, an error code on failure. 
 */
int  tcpIOCtl(u_int td, int cmd, void *arg);

#endif