upstream: Fix calculation of initial bandwidth limits. Account for

written bytes before the initial timer check so that the first buffer written
is accounted.  Set the threshold after which the timer is checked such that
the limit starts being computed as soon as possible, ie after the second
buffer is written.  This prevents an initial burst of traffic and provides a
more accurate bandwidth limit.  bz#2927, ok djm.

OpenBSD-Commit-ID: ff3ef76e4e43040ec198c2718d5682c36b255cb6

1 files changed, 4 insertions, 5 deletions

diff --git a/misc.c b/misc.c
index dd74c8d45..275e68141 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.134 2018/11/16 03:26:01 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.135 2018/12/07 04:36:09 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -1335,11 +1335,11 @@ bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
 {
 	bw->buflen = buflen;
 	bw->rate = kbps;
-	bw->thresh = bw->rate;
+	bw->thresh = buflen;
 	bw->lamt = 0;
 	timerclear(&bw->bwstart);
 	timerclear(&bw->bwend);
-}	
+}
 
 /* Callback from read/write loop to insert bandwidth-limiting delays */
 void
@@ -1348,12 +1348,11 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
 	u_int64_t waitlen;
 	struct timespec ts, rm;
 
+	bw->lamt += read_len;
 	if (!timerisset(&bw->bwstart)) {
 		monotime_tv(&bw->bwstart);
 		return;
 	}
-
-	bw->lamt += read_len;
 	if (bw->lamt < bw->thresh)
 		return;