/*
	tcp.h
	
	TCP protocol header
	
	Copyright 1999, Be Incorporated, All Rights Reserved.
*/

/*
 * portions of this file are:
 */
/*
 * Copyright (c) 1982, 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND 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 REGENTS OR 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.
 *
 */

#ifndef H_NETINET_TCP
#define H_NETINET_TCP

#include <OS.h>
#include <ByteOrder.h>

typedef uint32 tcp_seq;

/*
 * TCP header.
 * Per RFC 793, September, 1981.
 */
typedef struct tcphdr {
        uint16 th_sport;               /* source port */
        uint16 th_dport;               /* destination port */
        tcp_seq th_seq;                 /* sequence number */
        uint32 th_ack;                 /* acknowledgement number */
#if BYTE_ORDER == LITTLE_ENDIAN
        uint8  th_x2 :4,                /* (unused) */
               th_off:4;               /* data offset */
#endif
#if BYTE_ORDER == BIG_ENDIAN
        uint8  th_off:4,               /* data offset */
               th_x2 :4;                /* (unused) */
#endif
        uint8  th_flags;
#define TH_FIN  0x01
#define TH_SYN  0x02
#define TH_RST  0x04
#define TH_PUSH 0x08
#define TH_ACK  0x10
#define TH_URG  0x20
#define TH_FLAGS (TH_FIN|TH_SYN|TH_RST|TH_ACK|TH_URG)

        uint16 th_win;                 /* window */
        uint16 th_sum;                 /* checksum */
        uint16 th_urp;                 /* urgent pointer */
} tcphdr_t;



#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_SACK_PERMITTED 		4               /* Experimental */
#define    TCPOLEN_SACK_PERMITTED   2
#define TCPOPT_SACK            		5               /* Experimental */
#define TCPOPT_TIMESTAMP        	8
#define    TCPOLEN_TIMESTAMP        10
#define    TCPOLEN_TSTAMP_APPA      (TCPOLEN_TIMESTAMP+2) /* appendix A */
#define    TCPOPT_TSTAMP_HDR            \
    (TCPOPT_NOP<<24|TCPOPT_NOP<<16|TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)



/*
 * Default maximum segment size for TCP.
 * With an IP MSS of 576, this is 536,
 * but 512 is probably more convenient.
 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
 */
#define TCP_MSS						512
	
#define TCP_MAXWIN      			65535   /* largest value for (unscaled) window */
#define TCP_MAX_WINSHIFT	        14      /* maximum window shift */
	
#define TCP_MAXHLEN     			(0xf<<2)        /* max length of header in bytes */
#define TCP_MAXOLEN     			(TCP_MAXHLEN - sizeof(struct tcphdr))
                                        /* max space left for options */

/*
 * User-settable options (used with setsockopt).
 */
#define TCP_NODELAY     			0x01    /* don't delay send to coalesce packets */
#define TCP_MAXSEG      			0x02    /* set maximum segment size */
#define TCP_NOPUSH      			0x04    /* don't push last block of write */
#define TCP_NOOPT					0x08	/* don't use options */
#define TCP_MAXRT      				0x10    /* time in seconds until connection is broken after retransmit */

#endif

