OpenSolaris Launch

1 files changed, 117 insertions, 0 deletions

diff --git a/usr/src/uts/common/netinet/tcp_timer.h b/usr/src/uts/common/netinet/tcp_timer.h
new file mode 100644
index 0000000000..e19bb3ce85
--- /dev/null
+++ b/usr/src/uts/common/netinet/tcp_timer.h
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+/*
+ * Copyright (c) 1982, 1986 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ */
+
+/*
+ * Definitions of the TCP timers.  These timers are counted
+ * down PR_SLOWHZ times a second.
+ */
+
+#ifndef	_NETINET_TCP_TIMER_H
+#define	_NETINET_TCP_TIMER_H
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+/* tcp_timer.h 1.13 89/06/16 SMI; from UCB 7.6 6/29/88 */
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#define	TCPT_NTIMERS	4
+
+#define	TCPT_REXMT	0		/* retransmit */
+#define	TCPT_PERSIST	1		/* retransmit persistance */
+#define	TCPT_KEEP	2		/* keep alive */
+#define	TCPT_2MSL	3		/* 2*msl quiet time timer */
+
+/*
+ * The TCPT_REXMT timer is used to force retransmissions.
+ * The TCP has the TCPT_REXMT timer set whenever segments
+ * have been sent for which ACKs are expected but not yet
+ * received.  If an ACK is received which advances tp->snd_una,
+ * then the retransmit timer is cleared (if there are no more
+ * outstanding segments) or reset to the base value (if there
+ * are more ACKs expected).  Whenever the retransmit timer goes off,
+ * we retransmit one unacknowledged segment, and do a backoff
+ * on the retransmit timer.
+ *
+ * The TCPT_PERSIST timer is used to keep window size information
+ * flowing even if the window goes shut.  If all previous transmissions
+ * have been acknowledged (so that there are no retransmissions in progress),
+ * and the window is too small to bother sending anything, then we start
+ * the TCPT_PERSIST timer.  When it expires, if the window is nonzero,
+ * we go to transmit state.  Otherwise, at intervals send a single byte
+ * into the peer's window to force him to update our window information.
+ * We do this at most as often as TCPT_PERSMIN time intervals,
+ * but no more frequently than the current estimate of round-trip
+ * packet time.  The TCPT_PERSIST timer is cleared whenever we receive
+ * a window update from the peer.
+ *
+ * The TCPT_KEEP timer is used to keep connections alive.  If a
+ * connection is idle (no segments received) for TCPTV_KEEP_INIT amount of time,
+ * but not yet established, then we drop the connection.  Once the connection
+ * is established, if the connection is idle for TCPTV_KEEP_IDLE time
+ * (and keepalives have been enabled on the socket), we begin to probe
+ * the connection.  We force the peer to send us a segment by sending:
+ *	<SEQ=SND.UNA-1><ACK=RCV.NXT><CTL=ACK>
+ * This segment is (deliberately) outside the window, and should elicit
+ * an ack segment in response from the peer.  If, despite the TCPT_KEEP
+ * initiated segments we cannot elicit a response from a peer in TCPT_MAXIDLE
+ * amount of time probing, then we drop the connection.
+ */
+
+#define	TCP_TTL		60		/* default time to live for TCP segs */
+/*
+ * Time constants.
+ */
+#define	TCPTV_MSL	(30*PR_SLOWHZ)		/* max seg lifetime (hah!) */
+#define	TCPTV_SRTTBASE	0			/* base roundtrip time; */
+						/* if 0, no idea yet */
+#define	TCPTV_SRTTDFLT	(3*PR_SLOWHZ)		/* assumed RTT if no info */
+
+#define	TCPTV_PERSMIN	(5*PR_SLOWHZ)		/* retransmit persistance */
+#define	TCPTV_PERSMAX	(60*PR_SLOWHZ)		/* maximum persist interval */
+
+#define	TCPTV_KEEP_INIT	(75*PR_SLOWHZ)		/* initial connect keep alive */
+#define	TCPTV_KEEP_IDLE	(120*60*PR_SLOWHZ)	/* dflt time before probing */
+#define	TCPTV_KEEPINTVL	(75*PR_SLOWHZ)		/* default probe interval */
+#define	TCPTV_KEEPCNT	8			/* max probes before drop */
+
+#define	TCPTV_MIN	(1*PR_SLOWHZ)		/* minimum allowable value */
+#define	TCPTV_REXMTMAX	(64*PR_SLOWHZ)		/* max allowable REXMT value */
+
+#define	TCP_LINGERTIME	120			/* linger at most 2 minutes */
+
+#define	TCP_MAXRXTSHIFT	12			/* maximum retransmits */
+
+#ifdef	TCPTIMERS
+char *tcptimers[] =
+	{ "REXMT", "PERSIST", "KEEP", "2MSL" };
+#endif
+
+/*
+ * Force a time value to be in a certain range.
+ */
+#define	TCPT_RANGESET(tv, value, tvmin, tvmax) { \
+	(tv) = (value); \
+	if ((tv) < (tvmin)) \
+		(tv) = (tvmin); \
+	else if ((tv) > (tvmax)) \
+		(tv) = (tvmax); \
+}
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _NETINET_TCP_TIMER_H */