svn commit: r344368 - head/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Wed Feb 20 18:03:43 2019
New Revision: 344368
URL: https://svnweb.freebsd.org/changeset/base/344368

Log:
  Reduce the TCP initial retransmission timeout from 3 seconds to
  1 second as allowed by RFC 6298.
  
  Reviewed by:		kbowling@, Richard Scheffenegger
  Sponsored by:		Netflix, Inc.
  Differential Revision:	https://reviews.freebsd.org/D18941

Modified:
  head/sys/netinet/tcp_syncache.c
  head/sys/netinet/tcp_timer.h

Modified: head/sys/netinet/tcp_syncache.c
==============================================================================
--- head/sys/netinet/tcp_syncache.c	Wed Feb 20 17:56:38 2019	(r344367)
+++ head/sys/netinet/tcp_syncache.c	Wed Feb 20 18:03:43 2019	(r344368)
@@ -159,7 +159,7 @@ static int	 syncookie_cmp(struct in_conninfo *inc, str
  *                  tcp_backoff[1] +
  *                  tcp_backoff[2] +
  *                  tcp_backoff[3]) + 3 * tcp_rexmit_slop,
- * 3000 ms * (1 + 2 + 4 + 8) +  3 * 200 ms = 45600 ms,
+ * 1000 ms * (1 + 2 + 4 + 8) +  3 * 200 ms = 15600 ms,
  * the odds are that the user has given up attempting to connect by then.
  */
 #define SYNCACHE_MAXREXMTS		3

Modified: head/sys/netinet/tcp_timer.h
==============================================================================
--- head/sys/netinet/tcp_timer.h	Wed Feb 20 17:56:38 2019	(r344367)
+++ head/sys/netinet/tcp_timer.h	Wed Feb 20 18:03:43 2019	(r344368)
@@ -77,7 +77,7 @@
 #define	TCPTV_MSL	( 30*hz)		/* max seg lifetime (hah!) */
 #define	TCPTV_SRTTBASE	0			/* base roundtrip time;
 						   if 0, no idea yet */
-#define	TCPTV_RTOBASE	(  3*hz)		/* assumed RTO if no info */
+#define	TCPTV_RTOBASE	(  1*hz)		/* assumed RTO if no info */
 
 #define	TCPTV_PERSMIN	(  5*hz)		/* minimum persist interval */
 #define	TCPTV_PERSMAX	( 60*hz)		/* maximum persist interval */