git: 873f8376015c - stable/13 - rack: unbreak TCP fast open for the client side

[Michael Tuexen]

The branch stable/13 has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=873f8376015c12febec3619976a8c30fbead4ad6

commit 873f8376015c12febec3619976a8c30fbead4ad6
Author:     Michael Tuexen <tuexen at FreeBSD.org>
AuthorDate: 2021-03-05 14:57:26 +0000
Commit:     Michael Tuexen <tuexen at FreeBSD.org>
CommitDate: 2021-03-08 12:27:30 +0000

    rack: unbreak TCP fast open for the client side
    
    Allow sending user data on the SYN segment.
    
    Reviewed by:            rrs
    Differential Revision:  https://reviews.freebsd.org/D29082
    Sponsored by:           Netflix, Inc.
    
    (cherry picked from commit 705d06b289e9821439b7b694d766cad75bc064e5)
---
 sys/netinet/tcp_stacks/rack.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c
index 4d1a4cc8a0eb..104468bee53b 100644
--- a/sys/netinet/tcp_stacks/rack.c
+++ b/sys/netinet/tcp_stacks/rack.c
@@ -12297,7 +12297,8 @@ again:
 	 * If sack_rxmit is true we are retransmitting from the scoreboard
 	 * in which case len is already set.
 	 */
-	if ((sack_rxmit == 0) && TCPS_HAVEESTABLISHED(tp->t_state)) {
+	if ((sack_rxmit == 0) &&
+	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
 		uint32_t avail;
 
 		avail = sbavail(sb);