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    Length: 4541 (0x11bd)
    Types: TextFile
    Notes: UNIX file
    Names: »tcp_var.h«

└─⟦8c4f54e61⟧ Bits:30004068/disk2.imd Interactive TCP/IP v.1.2
└─⟦8c4f54e61⟧ UNIX Filesystem
    └─⟦this⟧ »hb/new/usr/include/netinet/tcp_var.h« 

TextFile

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)tcp_var.h	2.3 - 90/01/11
 */

#ifndef _h_TCP_VAR 
#define _h_TCP_VAR 
#ident "@(#)tcp_var.h	2.3 - 90/01/11"

/*
 * Kernel variables for tcp.
 */

/*
 * Tcp control block, one per tcp; fields:
 */
struct tcpcb {
	mblk_t	*seg_next;	/* sequencing queue */
	mblk_t	*seg_prev;
	mblk_t  *t_mblk;	/* mblk for this pcb */
	short	t_state;		/* state of this connection */
	short	t_timer[TCPT_NTIMERS];	/* tcp timers */
	short	t_rxtshift;		/* log(2) of rexmt exp. backoff */
	short   t_rxtcur;		/*current retansmit value*/
	short   t_dupacks;		/*consecutive dup acks recd*/
	short	t_sflags;	/* flags for stream management */
#define TFS_DISCONN	0x01	/* disconnect has been requested */
#define TFS_CLOSED	0x02	/* the stream has been closed - release */
#define TFS_UBLOCKED	0x04	/* upstream has been flow controlled */
#define TFS_SCANNED	0x08	/* has been scanned in tcplrsrv */
#define TFS_DBLOCKED	0x10	/* upstream's write queue blocked */
#define TFS_ESTABLISH	0x20	/* in process of establishing connection */
	mblk_t *t_tcpopt;		/* tcp options */
	u_short	t_maxseg;		/* maximum segment size */
	char	t_force;		/* 1 if forcing out a byte */
	u_char	t_flags;
#define	TF_ACKNOW	0x01		/* ack peer immediately */
#define	TF_DELACK	0x02		/* ack, but try to delay it */
#define	TF_NODELAY	0x04		/* don't delay packets to coalesce */
#define	TF_NOOPT	0x08		/* don't use tcp options */
#define	TF_SENTFIN	0x10		/* have sent FIN */
#define TF_DRAIN	0x20
	mblk_t		 *t_template;	/* skeletal packet for transmit */
	struct	inpcb *t_inpcb;		/* back pointer to internet pcb */
/*
 * The following fields are used as in the protocol specification.
 * See RFC783, Dec. 1981, page 21.
 */
/* send sequence variables */
	tcp_seq	snd_una;		/* send unacknowledged */
	tcp_seq	snd_nxt;		/* send next */
	tcp_seq	snd_up;			/* send urgent pointer */
	tcp_seq	snd_wl1;		/* window update seg seq number */
	tcp_seq	snd_wl2;		/* window update seg ack number */
	tcp_seq	iss;			/* initial send sequence number */
	u_short	snd_wnd;		/* send window */
/* receive sequence variables */
	u_short	rcv_wnd;		/* receive window */
	tcp_seq	rcv_nxt;		/* receive next */
	tcp_seq	rcv_up;			/* receive urgent pointer */
	tcp_seq	irs;			/* initial receive sequence number */
/*
 * Additional variables for this implementation.
 */
/* receive variables */
	tcp_seq	rcv_adv;		/* advertised window */
/* retransmit variables */
	tcp_seq	snd_max;		/* highest sequence number sent
					 * used to recognize retransmits
					 */
/* congestion control (for source quench) */
	u_short	snd_cwnd;		/* congestion-controlled window */
	u_short	snd_ssthresh;		/* snd_cwnd size threshhold for
				         * slow start exponential to
					 * linear switch */
/* transmit timing stuff 
 * srtt snf rttvar are stored as fixed point; for convience in smoothing,
 * srtt has 3 bits to the right of the binary point, rttvar has 2.
 * "Variance" is actually smoothed difference.
 */
	short	t_idle;			/* inactivity time */
	short	t_rtt;			/* round trip time */
	u_short max_rcvd;		/* most peer has sent into window */
	tcp_seq	t_rtseq;		/* sequence number being timed */
#ifdef OLDHBTCP
	long	t_srtt;			/* smoothed round-trip time */
#else
	short	t_srtt;			/* smoothed round-trip time */
	short	t_rttvar;		/* variance in round trip time*/
#endif /*OLDHBTCP*/
	u_short	max_sndwnd;		/* largest window peer has offered */
/* out-of-band data */
	char	t_oobflags;		/* have some */
	char	t_iobc;			/* input character */
#define	TCPOOB_HAVEDATA	0x01
#define	TCPOOB_HADDATA	0x02
#define TCPOOB_RFCFORM  0x10	/* follow RFC961 interpretation */
#define TCPOOB_SEGMENT  0x20	/* try to get all data, not just last */
				/* this isn't entirely meaningful given */
				/* that only the "end" is provided */
};

#define	intotcpcb(ip)	((struct tcpcb *) ((mblk_t *)(ip)->inp_ppcb)->b_rptr)
#define	sototcpcb(so)	(intotcpcb(sotoinpcb(so)))

#ifndef IP_MAXPACKET
#define IP_MAXPACKET	65535
#endif
struct	tcpstat {
	int	tcps_badsum;
	int	tcps_badoff;
	int	tcps_hdrops;
	int	tcps_badsegs;
	int	tcps_unack;
};

#ifdef KERNEL
extern struct	inpcb tcb;		/* head of queue of active tcpcb's */
extern struct	tcpstat tcpstat;	/* tcp statistics */
extern mblk_t  *tcp_template();
extern struct	tcpcb *tcp_close(), *tcp_drop();
extern struct	tcpcb *tcp_timers(), *tcp_disconnect(), *tcp_usrclosed();
#endif
#endif /* _h_TCP_VAR  */