[newlib-cygwin] tcp: Add hystart-plus to cc_newreno and rack.

[newlib-cygwin] tcp: Add hystart-plus to cc_newreno and rack.

[Sebastian Huber]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=0464f26db0c35b01281c5189b35d4388b49507f5

commit 0464f26db0c35b01281c5189b35d4388b49507f5
Author: Randall Stewart <rrs@FreeBSD.org>
Date:   Fri Oct 22 07:10:28 2021 -0400

    tcp: Add hystart-plus to cc_newreno and rack.
    
    TCP Hystart draft version -03:
    https://datatracker.ietf.org/doc/html/draft-ietf-tcpm-hystartplusplus
    
    Is a new version of hystart that allows one to carefully exit slow start if the RTT
    spikes too much. The newer version has a slower-slow-start so to speak that then
    kicks in for five round trips. To see if you exited too early, if not into congestion avoidance.
    This commit will add that feature to our newreno CC and add the needed bits in rack to
    be able to enable it.
    
    Reviewed by: tuexen
    Sponsored by: Netflix Inc.
    Differential Revision:  https://reviews.freebsd.org/D32373

Diff:
---
 newlib/libc/sys/rtems/include/netinet/tcp.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/newlib/libc/sys/rtems/include/netinet/tcp.h b/newlib/libc/sys/rtems/include/netinet/tcp.h
index 29c1e376c..e7c47e85b 100644
--- a/newlib/libc/sys/rtems/include/netinet/tcp.h
+++ b/newlib/libc/sys/rtems/include/netinet/tcp.h
@@ -310,7 +310,7 @@ struct tcphdr {
 #define TCP_RACK_PACING_BETA_ECN 1139	/* Changing the beta for ecn with pacing */
 #define TCP_RACK_TIMER_SLOP 1140	/* Set or get the timer slop used */
 #define TCP_RACK_DSACK_OPT 1141		/* How do we setup rack timer DSACK options bit 1/2 */
-
+#define TCP_RACK_ENABLE_HYSTART 1142	/* Do we allow hystart in the CC modules */
 /* Start of reserved space for third-party user-settable options. */
 #define	TCP_VENDOR	SO_VENDOR