tcp_var.h

KPIT GNU Tools is a set of GNU development tools for Renesas microcontrollers.

#define rmx_taop(r)	((struct rmxp_tao *)(r).rmx_filler)

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

/*
 * The smoothed round-trip time and estimated variance
 * are stored as fixed point numbers scaled by the values below.
 * For convenience, these scales are also used in smoothing the average
 * (smoothed = (1/scale)sample + ((scale-1)/scale)smoothed).
 * With these scales, srtt has 3 bits to the right of the binary point,
 * and thus an "ALPHA" of 0.875.  rttvar has 2 bits to the right of the
 * binary point, and is smoothed with an ALPHA of 0.75.
 */
#define	TCP_RTT_SCALE		32	/* multiplier for srtt; 3 bits frac. */
#define	TCP_RTT_SHIFT		5	/* shift for srtt; 3 bits frac. */
#define	TCP_RTTVAR_SCALE	16	/* multiplier for rttvar; 2 bits */
#define	TCP_RTTVAR_SHIFT	4	/* shift for rttvar; 2 bits */
#define	TCP_DELTA_SHIFT		2	/* see tcp_input.c */

/*
 * The initial retransmission should happen at rtt + 4 * rttvar.
 * Because of the way we do the smoothing, srtt and rttvar
 * will each average +1/2 tick of bias.  When we compute
 * the retransmit timer, we want 1/2 tick of rounding and
 * 1 extra tick because of +-1/2 tick uncertainty in the
 * firing of the timer.  The bias will give us exactly the
 * 1.5 tick we need.  But, because the bias is
 * statistical, we have to test that we don't drop below
 * the minimum feasible timer (which is 2 ticks).
 * This version of the macro adapted from a paper by Lawrence
 * Brakmo and Larry Peterson which outlines a problem caused
 * by insufficient precision in the original implementation,
 * which results in inappropriately large RTO values for very
 * fast networks.
 */
#define	TCP_REXMTVAL(tp) \
	max((tp)->t_rttmin, (((tp)->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT))  \
	  + (tp)->t_rttvar) >> TCP_DELTA_SHIFT)

/*
 * TCP statistics.
 * Many of these should be kept per connection,
 * but that's inconvenient at the moment.
 */
struct	tcpstat {
	u_long	tcps_connattempt;	/* connections initiated */
	u_long	tcps_accepts;		/* connections accepted */
	u_long	tcps_connects;		/* connections established */
	u_long	tcps_drops;		/* connections dropped */
	u_long	tcps_conndrops;		/* embryonic connections dropped */
	u_long	tcps_closed;		/* conn. closed (includes drops) */
	u_long	tcps_segstimed;		/* segs where we tried to get rtt */
	u_long	tcps_rttupdated;	/* times we succeeded */
	u_long	tcps_delack;		/* delayed acks sent */
	u_long	tcps_timeoutdrop;	/* conn. dropped in rxmt timeout */
	u_long	tcps_rexmttimeo;	/* retransmit timeouts */
	u_long	tcps_persisttimeo;	/* persist timeouts */
	u_long	tcps_keeptimeo;		/* keepalive timeouts */
	u_long	tcps_keepprobe;		/* keepalive probes sent */
	u_long	tcps_keepdrops;		/* connections dropped in keepalive */

	u_long	tcps_sndtotal;		/* total packets sent */
	u_long	tcps_sndpack;		/* data packets sent */
	u_long	tcps_sndbyte;		/* data bytes sent */
	u_long	tcps_sndrexmitpack;	/* data packets retransmitted */
	u_long	tcps_sndrexmitbyte;	/* data bytes retransmitted */
	u_long	tcps_sndacks;		/* ack-only packets sent */
	u_long	tcps_sndprobe;		/* window probes sent */
	u_long	tcps_sndurg;		/* packets sent with URG only */
	u_long	tcps_sndwinup;		/* window update-only packets sent */
	u_long	tcps_sndctrl;		/* control (SYN|FIN|RST) packets sent */

	u_long	tcps_rcvtotal;		/* total packets received */
	u_long	tcps_rcvpack;		/* packets received in sequence */
	u_long	tcps_rcvbyte;		/* bytes received in sequence */
	u_long	tcps_rcvbadsum;		/* packets received with ccksum errs */
	u_long	tcps_rcvbadoff;		/* packets received with bad offset */
	u_long	tcps_rcvmemdrop;	/* packets dropped for lack of memory */
	u_long	tcps_rcvshort;		/* packets received too short */
	u_long	tcps_rcvduppack;	/* duplicate-only packets received */
	u_long	tcps_rcvdupbyte;	/* duplicate-only bytes received */
	u_long	tcps_rcvpartduppack;	/* packets with some duplicate data */
	u_long	tcps_rcvpartdupbyte;	/* dup. bytes in part-dup. packets */
	u_long	tcps_rcvoopack;		/* out-of-order packets received */
	u_long	tcps_rcvoobyte;		/* out-of-order bytes received */
	u_long	tcps_rcvpackafterwin;	/* packets with data after window */
	u_long	tcps_rcvbyteafterwin;	/* bytes rcvd after window */
	u_long	tcps_rcvafterclose;	/* packets rcvd after "close" */
	u_long	tcps_rcvwinprobe;	/* rcvd window probe packets */
	u_long	tcps_rcvdupack;		/* rcvd duplicate acks */
	u_long	tcps_rcvacktoomuch;	/* rcvd acks for unsent data */
	u_long	tcps_rcvackpack;	/* rcvd ack packets */
	u_long	tcps_rcvackbyte;	/* bytes acked by rcvd acks */
	u_long	tcps_rcvwinupd;		/* rcvd window update packets */
	u_long	tcps_pawsdrop;		/* segments dropped due to PAWS */
	u_long	tcps_predack;		/* times hdr predict ok for acks */
	u_long	tcps_preddat;		/* times hdr predict ok for data pkts */
	u_long	tcps_pcbcachemiss;
	u_long	tcps_cachedrtt;		/* times cached RTT in route updated */
	u_long	tcps_cachedrttvar;	/* times cached rttvar updated */
	u_long	tcps_cachedssthresh;	/* times cached ssthresh updated */
	u_long	tcps_usedrtt;		/* times RTT initialized from route */
	u_long	tcps_usedrttvar;	/* times RTTVAR initialized from rt */
	u_long	tcps_usedssthresh;	/* times ssthresh initialized from rt*/
	u_long	tcps_persistdrop;	/* timeout in persist state */
	u_long	tcps_badsyn;		/* bogus SYN, e.g. premature ACK */
	u_long	tcps_mturesent;		/* resends due to MTU discovery */
	u_long	tcps_listendrop;	/* listen queue overflows */

	u_long	tcps_sc_added;		/* entry added to syncache */
	u_long	tcps_sc_retransmitted;	/* syncache entry was retransmitted */
	u_long	tcps_sc_dupsyn;		/* duplicate SYN packet */
	u_long	tcps_sc_dropped;	/* could not reply to packet */
	u_long	tcps_sc_completed;	/* successful extraction of entry */
	u_long	tcps_sc_bucketoverflow;	/* syncache per-bucket limit hit */
	u_long	tcps_sc_cacheoverflow;	/* syncache cache limit hit */
	u_long	tcps_sc_reset;		/* RST removed entry from syncache */
	u_long	tcps_sc_stale;		/* timed out or listen socket gone */
	u_long	tcps_sc_aborted;	/* syncache entry aborted */
	u_long	tcps_sc_badack;		/* removed due to bad ACK */
	u_long	tcps_sc_unreach;	/* ICMP unreachable received */
	u_long	tcps_sc_zonefail;	/* zalloc() failed */
	u_long	tcps_sc_sendcookie;	/* SYN cookie sent */
	u_long	tcps_sc_recvcookie;	/* SYN cookie received */
};

/*
 * TCB structure exported to user-land via sysctl(3).
 * Evil hack: declare only if in_pcb.h and sys/socketvar.h have been
 * included.  Not all of our clients do.
 */
#if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
struct	xtcpcb {
	size_t	xt_len;
	struct	inpcb	xt_inp;
	struct	tcpcb	xt_tp;
	struct	xsocket	xt_socket;
	u_quad_t	xt_alignment_hack;
};
#endif

/*
 * Names for TCP sysctl objects
 */
#define	TCPCTL_DO_RFC1323	1	/* use RFC-1323 extensions */
#define	TCPCTL_DO_RFC1644	2	/* use RFC-1644 extensions */
#define	TCPCTL_MSSDFLT		3	/* MSS default */
#define TCPCTL_STATS		4	/* statistics (read-only) */
#define	TCPCTL_RTTDFLT		5	/* default RTT estimate */
#define	TCPCTL_KEEPIDLE		6	/* keepalive idle timer */
#define	TCPCTL_KEEPINTVL	7	/* interval to send keepalives */
#define	TCPCTL_SENDSPACE	8	/* send buffer space */
#define	TCPCTL_RECVSPACE	9	/* receive buffer space */
#define	TCPCTL_KEEPINIT		10	/* timeout for establishing syn */
#define	TCPCTL_PCBLIST		11	/* list of all outstanding PCBs */
#define	TCPCTL_DELACKTIME	12	/* time before sending delayed ACK */
#define	TCPCTL_V6MSSDFLT	13	/* MSS default for IPv6 */
#define	TCPCTL_MAXID		14

#define TCPCTL_NAMES { \
	{ 0, 0 }, \
	{ "rfc1323", CTLTYPE_INT }, \
	{ "rfc1644", CTLTYPE_INT }, \
	{ "mssdflt", CTLTYPE_INT }, \
	{ "stats", CTLTYPE_STRUCT }, \
	{ "rttdflt", CTLTYPE_INT }, \
	{ "keepidle", CTLTYPE_INT }, \
	{ "keepintvl", CTLTYPE_INT }, \
	{ "sendspace", CTLTYPE_INT }, \
	{ "recvspace", CTLTYPE_INT }, \
	{ "keepinit", CTLTYPE_INT }, \
	{ "pcblist", CTLTYPE_STRUCT }, \
	{ "delacktime", CTLTYPE_INT }, \
	{ "v6mssdflt", CTLTYPE_INT }, \
}


#ifdef _KERNEL
#ifdef SYSCTL_DECL
SYSCTL_DECL(_net_inet_tcp);
#endif

extern	struct inpcbhead tcb;		/* head of queue of active tcpcb's */
extern	struct inpcbinfo tcbinfo;
extern	struct tcpstat tcpstat;	/* tcp statistics */
extern	int tcp_mssdflt;	/* XXX */
extern	int tcp_delack_enabled;
extern	int tcp_do_newreno;
extern	int ss_fltsz;
extern	int ss_fltsz_local;

void	 tcp_canceltimers(struct tcpcb *);
struct tcpcb *
	 tcp_close(struct tcpcb *);
void	 tcp_ctlinput(int, struct sockaddr *, void *);
int	 tcp_ctloutput(struct socket *, struct sockopt *);
struct tcpcb *
	 tcp_drop(struct tcpcb *, int);
void	 tcp_drain(void);
void	 tcp_fasttimo(void);
struct rmxp_tao *
	 tcp_gettaocache(struct in_conninfo *);
void	 tcp_init(void);
void	 tcp_input(struct mbuf *, int);
void	 tcp_mss(struct tcpcb *, int);
int	 tcp_mssopt(struct tcpcb *);
void	 tcp_drop_syn_sent(struct inpcb *, int);
void	 tcp_mtudisc(struct inpcb *, int);
struct tcpcb *
	 tcp_newtcpcb(struct inpcb *);
int	 tcp_output(struct tcpcb *);
void	 tcp_quench(struct inpcb *, int);
void	 tcp_respond(struct tcpcb *, void *,
	    struct tcphdr *, struct mbuf *, tcp_seq, tcp_seq, int);
struct rtentry *
	 tcp_rtlookup(struct in_conninfo *);
void	 tcp_setpersist(struct tcpcb *);
void	 tcp_slowtimo(void);
struct tcptemp *
	 tcp_maketemplate(struct tcpcb *);
void	 tcp_fillheaders(struct tcpcb *, void *, void *);
struct tcpcb *
	 tcp_timers(struct tcpcb *, int);
void	 tcp_trace(int, int, struct tcpcb *, void *, struct tcphdr *, int);
void	 syncache_init(void);
void	 syncache_unreach(struct in_conninfo *, struct tcphdr *);
int	 syncache_expand(struct in_conninfo *, struct tcphdr *,
	     struct socket **, struct mbuf *);
int	 syncache_add(struct in_conninfo *, struct tcpopt *,
	     struct tcphdr *, struct socket **, struct mbuf *);
void	 syncache_chkrst(struct in_conninfo *, struct tcphdr *);
void	 syncache_badack(struct in_conninfo *);

extern	struct pr_usrreqs tcp_usrreqs;
extern	u_long tcp_sendspace;
extern	u_long tcp_recvspace;
tcp_seq tcp_new_isn(struct tcpcb *);

#endif /* _KERNEL */

#endif /* _NETINET_TCP_VAR_H_ */