#

/* Struct which keeps info on round trip delay times.
 Used to compute time between retransmits;
 retranmits times are computed to nearest second */

#define NTT	10

struct ttime {
	struct ttseq	*tt_begin;	/* Ptr to tt_list[0] */
	struct ttseq	*tt_end;	/* Ptr to tt_list[NTT] */
	struct ttseq	*tt_first;	/* First unacked seqno */
	struct ttseq	*tt_next;	/* Loc. for next seqno/sndtime */
	struct ttseq {
			long	tt_seqno;
			long	tt_sndtime;
			long	tt_acktime;
			} tt_list[NTT];
	};

#define RETRANSTIME	3	/* Initial retransmit time */
#define NTRANS		20	/* No. times to retransmit */
#define LONGSLEEP	255

#define MAXDATA		512	/* Max rcv/send segment data - must be
				<= MAXINET - (IPHSIZ + TCPHSIZ) */

struct tcb {
	int	t_state;
	int	t_flags;
	long	t_urgseq;	/* Seqno for end of urgent data */
	int	t_maxdata;	/* Max. tcp data we will send/rcv */
	int	t_maxsdata;	/* Max. tcp data to send on connection */
	long	t_iss;		/* Initial send sequence no. */
	long	t_snxt;		/* Next send seq. no. */
	long	t_suna;		/* Highest send seqno wh. has been acked */
	short	t_swnd;		/* Send window */
	long	t_swseq;	/* Seqno when send wnd updated */
	long	t_swack;	/* Ackno when send wnd updated */
	long	t_irs;		/* Initial rcv sequence no. */
	long	t_rnxt;		/* Next rcv seq. no. */
	int	t_rwnd;		/* Rcv window */
	long	t_rlast;	/* Last expected rcv seq. no. */
	long	t_acktime;	/* Set first time decide to send ACK */
	long	t_fintime;	/* Set when rcv FIN */
	long	t_sndtime;	/* Set when update t_suna or retransmit */
	int	t_ntrans;	/* No. times retransmitted */
	int	t_retrans;	/* Current retransmit time in seconds */
	struct ttime	t_ttime;/* Data to compute retrans time */
	struct tcp_phdr	t_phdr;	/* Tcp pseudo-header */
	struct net_hdr	t_net;	
	struct inet_hdr	t_inet;
	struct tcp_hdr	t_tcp;
	char		t_data[MAXDATA];
	};

/* Tcb Flags */
#define URGF	01

/* Tcb state bits */
#define LISTEN		0
#define SYN_SENT	01
#define SYN_ACK		02
#define SYN_RCVD	04
#define FIN_SENT	010
#define FIN_ACK		020
#define FIN_RCVD	040
#define CLOSED2		0100

#define OPEN		(SYN_SENT|SYN_ACK|SYN_RCVD)
#define CLOSED		(FIN_SENT|FIN_ACK|FIN_RCVD)


#define NBUF		8		/* No. rcv buffers */

#define NETDATA		(NETHSIZ + IPHSIZ + MAXINET)

struct rcvpkt {
	struct item	rp_que;
	short		rp_len;
	long		rp_seqno;	/* Adjusted begin seqno */
	short		rp_dlen;	/* Amt. of legit. segment data */
	char		*rp_datp;	/* Ptr to next char to give to user */
	char		*rp_date;	/* Ptr to last + 1 char for user */
	struct net_hdr	rp_net;
	struct inet_hdr	rp_inet;
	char		rp_data[MAXINET];
	};

#define RCVPKTSIZ	sizeof(struct rcvpkt)

#define NSBUFF	2000

struct sndcbuf {
	short		sb_flags;
	short		sb_len;
	char		*sb_datp;	/* Loc. of first char for tcp */
	char		*sb_date;	/* Loc. of last char for tcp */
	long		sb_seqno;	/* Sequence no. of sb_datp */
	int		sb_urg;		/* Offset from sb_seqno for end
					   of urgent data - 0 if no urgent 
					   data */
	char		*sb_bbuff;	/* Begin addr of sb_data */
	char		*sb_ebuff;	/* End addr + 1 of sb_data */
	char		sb_data[NSBUFF];
	};

#define SNDCBUFSIZ	sizeof(struct sndcbuf)

/* sndcbuf flags */
#define SNDSYN	01
#define SNDFIN	02

/* Statistics */
#define WEIO	1	/* Net write err 5 */
#define WREFUSE	2	/* Net write err 13 */
#define WERR	3	/* Other net write error */
#define NERR	4

struct stats {
	long	s_rpkt;		/* No. pkts read */
	long	s_spkt;		/* No. pkts sent */
	short	s_rercv;	/* No. pkts w. some dupe data */
	short	s_resnd;	/* No. times retransmit */
	short	s_badord;	/* No. pkts rcved w. out of order data */
	short	s_errs[NERR];
	};

extern struct tcb	tcb;
extern struct rcvpkt	buff[NBUF];
extern struct sndcbuf	sndcbuf;
extern struct stats	stats;
extern struct que	frq, rseqq, rwaitq;