The branch stable/14 has been updated by tuexen:
URL:
https://cgit.FreeBSD.org/src/commit/?id=b7b48ba8420f6203ac7165b6b07c62929bb759e8
commit b7b48ba8420f6203ac7165b6b07c62929bb759e8
Author: Michael Tuexen <tue...@freebsd.org>
AuthorDate: 2025-10-02 06:57:14 +0000
Commit: Michael Tuexen <tue...@freebsd.org>
CommitDate: 2025-10-05 13:19:37 +0000
tcp: keep SYN-cache entry when sending of challenge ACK fails
Don't drop a SYN-cache entry just because a challenge ACK couldn't
be sent. This might only be a temporary failure.
Reviewed by: Nick Banks, glebius, jtl
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D52840
(cherry picked from commit 7841b44f8491d69c75207d0f3a1eb34501d99edd)
---
sys/netinet/tcp_syncache.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/sys/netinet/tcp_syncache.c b/sys/netinet/tcp_syncache.c
index 012240f46ffb..ce2ab29f4008 100644
--- a/sys/netinet/tcp_syncache.c
+++ b/sys/netinet/tcp_syncache.c
@@ -130,7 +130,7 @@ static void syncache_drop(struct syncache *, struct
syncache_head *);
static void syncache_free(struct syncache *);
static void syncache_insert(struct syncache *, struct syncache_head *);
static int syncache_respond(struct syncache *, const struct mbuf *, int);
-static int syncache_send_challenge_ack(struct syncache *, struct mbuf *);
+static void syncache_send_challenge_ack(struct syncache *, struct mbuf *);
static struct socket *syncache_socket(struct syncache *, struct socket *,
struct mbuf *m);
static void syncache_timeout(struct syncache *sc, struct syncache_head
*sch,
@@ -703,10 +703,7 @@ syncache_chkrst(struct in_conninfo *inc, struct tcphdr
*th, struct mbuf *m,
"sending challenge ACK\n",
s, __func__,
th->th_seq, sc->sc_irs + 1, sc->sc_wnd);
- if (syncache_send_challenge_ack(sc, m) != 0) {
- syncache_drop(sc, sch);
- TCPSTAT_INC(tcps_sc_dropped);
- }
+ syncache_send_challenge_ack(sc, m);
}
} else {
if ((s = tcp_log_addrs(inc, th, NULL, NULL)))
@@ -2062,22 +2059,16 @@ syncache_respond(struct syncache *sc, const struct mbuf
*m0, int flags)
return (error);
}
-static int
+static void
syncache_send_challenge_ack(struct syncache *sc, struct mbuf *m)
{
- int error;
-
if (tcp_challenge_ack_check(&sc->sc_challenge_ack_end,
&sc->sc_challenge_ack_cnt)) {
- error = syncache_respond(sc, m, TH_ACK);
- if (error == 0) {
+ if (syncache_respond(sc, m, TH_ACK) == 0) {
TCPSTAT_INC(tcps_sndacks);
TCPSTAT_INC(tcps_sndtotal);
}
- } else {
- error = 0;
}
- return (error);
}
/*
