git: 32cc4beb0a8c - main - tcp: retire TF_SENTSYN

The branch main has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=32cc4beb0a8c3cadc0de4c255ba512fd7b196607

commit 32cc4beb0a8c3cadc0de4c255ba512fd7b196607
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2026-04-03 19:22:11 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2026-04-03 19:22:11 +0000

    tcp: retire TF_SENTSYN
    
    This TF_-flag is only used in the RACK stack and not really needed.
    So replace it, since glebius@ needs a TF_ flag and right now all
    of them are taken.
    No functional change intended.
    
    Reviewed by:            rrs, glebius, rscheff, Nick Banks
    Sponsored by:           Netflix, Inc.
    Differential Revision:  https://reviews.freebsd.org/D56025
---
 sys/netinet/tcp_stacks/rack.c | 4 +---
 sys/netinet/tcp_var.h         | 4 ++--
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c
index 78b0026a8c5d..2e3fcc7a9762 100644
--- a/sys/netinet/tcp_stacks/rack.c
+++ b/sys/netinet/tcp_stacks/rack.c
@@ -22106,10 +22106,8 @@ out:
 		 * Now for special SYN/FIN handling.
 		 */
 		if (flags & (TH_SYN | TH_FIN)) {
-			if ((flags & TH_SYN) &&
-			    ((tp->t_flags & TF_SENTSYN) == 0)) {
+			if ((flags & TH_SYN) != 0 && tp->snd_max == tp->iss) {
 				tp->snd_max++;
-				tp->t_flags |= TF_SENTSYN;
 			}
 			if ((flags & TH_FIN) &&
 			    ((tp->t_flags & TF_SENTFIN) == 0)) {
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index a3a42b68c26b..95c4e4c52ba0 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -789,7 +789,7 @@ tcp_packets_this_ack(struct tcpcb *tp, tcp_seq ack)
 #define	TF_TSO		0x01000000	/* TSO enabled on this connection */
 #define	TF_TOE		0x02000000	/* this connection is offloaded */
 #define	TF_CLOSED	0x04000000	/* close(2) called on socket */
-#define TF_SENTSYN      0x08000000      /* At least one syn has been sent */
+#define	TF_UNUSED	0x08000000	/* was TF_SENTSYN */
 #define	TF_LRD		0x10000000	/* Lost Retransmission Detection */
 #define	TF_CONGRECOVERY	0x20000000	/* congestion recovery mode */
 #define	TF_WASCRECOVERY	0x40000000	/* was in congestion recovery */
@@ -803,7 +803,7 @@ tcp_packets_this_ack(struct tcpcb *tp, tcp_seq ack)
     "\15TF_NOPUSH\16TF_PREVVALID\17TF_WAKESOR\20TF_GPUTINPROG" \
     "\21TF_MORETOCOME\22TF_SONOTCONN\23TF_LASTIDLE\24TF_RXWIN0SENT" \
     "\25TF_FASTRECOVERY\26TF_WASFRECOVERY\27TF_SIGNATURE\30TF_FORCEDATA" \
-    "\31TF_TSO\32TF_TOE\33TF_CLOSED\34TF_SENTSYN" \
+    "\31TF_TSO\32TF_TOE\33TF_CLOSED\34TF_UNUSED" \
     "\35TF_LRD\36TF_CONGRECOVERY\37TF_WASCRECOVERY\40TF_FASTOPEN"
 
 #define	IN_FASTRECOVERY(t_flags)	(t_flags & TF_FASTRECOVERY)