initial import of NetBSD tree

1 files changed, 124 insertions, 0 deletions

diff --git a/sys/netns/spp_timer.h b/sys/netns/spp_timer.h
new file mode 100644
index 00000000000..533c555e396
--- /dev/null
+++ b/sys/netns/spp_timer.h
@@ -0,0 +1,124 @@
+/*	$NetBSD: spp_timer.h,v 1.6 1995/03/26 20:36:22 jtc Exp $	*/
+
+/*
+ * Copyright (c) 1982, 1986, 1988, 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.
+ *
+ *	@(#)spp_timer.h	8.1 (Berkeley) 6/10/93
+ */
+
+/*
+ * Definitions of the SPP timers.  These timers are counted
+ * down PR_SLOWHZ times a second.
+ */
+#define	SPPT_NTIMERS	4
+
+#define	SPPT_REXMT	0		/* retransmit */
+#define	SPPT_PERSIST	1		/* retransmit persistance */
+#define	SPPT_KEEP	2		/* keep alive */
+#define	SPPT_2MSL	3		/* 2*msl quiet time timer */
+
+/*
+ * The SPPT_REXMT timer is used to force retransmissions.
+ * The SPP has the SPPT_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 SPPT_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 SPPT_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 SPPT_PERSMIN time intervals,
+ * but no more frequently than the current estimate of round-trip
+ * packet time.  The SPPT_PERSIST timer is cleared whenever we receive
+ * a window update from the peer.
+ *
+ * The SPPT_KEEP timer is used to keep connections alive.  If an
+ * connection is idle (no segments received) for SPPTV_KEEP amount of time,
+ * but not yet established, then we drop the connection.  If the connection
+ * is established, then 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 SPPT_KEEP
+ * initiated segments we cannot elicit a response from a peer in SPPT_MAXIDLE
+ * amount of time, then we drop the connection.
+ */
+
+#define	SPP_TTL		30		/* default time to live for SPP segs */
+/*
+ * Time constants.
+ */
+#define	SPPTV_MSL	( 15*PR_SLOWHZ)		/* max seg lifetime */
+#define	SPPTV_SRTTBASE	0			/* base roundtrip time;
+						   if 0, no idea yet */
+#define	SPPTV_SRTTDFLT	(  3*PR_SLOWHZ)		/* assumed RTT if no info */
+
+#define	SPPTV_PERSMIN	(  5*PR_SLOWHZ)		/* retransmit persistance */
+#define	SPPTV_PERSMAX	( 60*PR_SLOWHZ)		/* maximum persist interval */
+
+#define	SPPTV_KEEP	( 75*PR_SLOWHZ)		/* keep alive - 75 secs */
+#define	SPPTV_MAXIDLE	(  8*SPPTV_KEEP)	/* maximum allowable idle
+						   time before drop conn */
+
+#define	SPPTV_MIN	(  1*PR_SLOWHZ)		/* minimum allowable value */
+#define	SPPTV_REXMTMAX	( 64*PR_SLOWHZ)		/* max allowable REXMT value */
+
+#define	SPP_LINGERTIME	120			/* linger at most 2 minutes */
+
+#define	SPP_MAXRXTSHIFT	12			/* maximum retransmits */
+
+#ifdef	SPPTIMERS
+char *spptimers[] =
+    { "REXMT", "PERSIST", "KEEP", "2MSL" };
+#endif
+
+/*
+ * Force a time value to be in a certain range.
+ */
+#define	SPPT_RANGESET(tv, value, tvmin, tvmax) { \
+	(tv) = (value); \
+	if ((tv) < (tvmin)) \
+		(tv) = (tvmin); \
+	else if ((tv) > (tvmax)) \
+		(tv) = (tvmax); \
+}
+
+#ifdef _KERNEL
+extern int spp_backoff[];
+#endif