The branch main has been updated by tuexen:
URL:
https://cgit.FreeBSD.org/src/commit/?id=c3fc0db3bc50df18a724e6e6b12ea4e060fd9255
commit c3fc0db3bc50df18a724e6e6b12ea4e060fd9255
Author: Michael Tuexen <tue...@freebsd.org>
AuthorDate: 2025-06-27 20:47:21 +0000
Commit: Michael Tuexen <tue...@freebsd.org>
CommitDate: 2025-06-27 20:47:21 +0000
tcp: set net.inet.tcp.nolocaltimewait to 0 and deprecate it
Set the default value of the sysctl-variable
net.inet.tcp.nolocaltimewait to 0. This will make the behavior
compliant with RFC 9293.
Furthermore document that using the sysctl-variable is deprecated
and will be removed in FreeBSD 16.
Reviewed by: glebius, Peter Lei
Relnotes: yes
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D5106
---
share/man/man4/tcp.4 | 14 ++++++++++----
sys/netinet/tcp_timewait.c | 24 +++++++++++++++++++++---
2 files changed, 31 insertions(+), 7 deletions(-)
diff --git a/share/man/man4/tcp.4 b/share/man/man4/tcp.4
index f19b6cb2ae14..fcfda42908d8 100644
--- a/share/man/man4/tcp.4
+++ b/share/man/man4/tcp.4
@@ -31,7 +31,7 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.Dd June 26, 2025
+.Dd June 27, 2025
.Dt TCP 4
.Os
.Sh NAME
@@ -785,8 +785,8 @@ The Maximum Segment Lifetime, in milliseconds, for a packet
when both endpoints
are local.
.Va msl_local
is only used if
-.Va nolocaltimewait
-is zero.
+.Va nolocaltimewait ,
+which is deprecated, is zero.
.It Va mssdflt
The default value used for the TCP Maximum Segment Size
.Pq Dq MSS
@@ -798,10 +798,16 @@ application limited and the network bandwidth is not
utilized completely.
That prevents self-inflicted packet losses once the application starts to
transmit data at a higher speed.
.It Va nolocaltimewait
-Suppress creation of TCP
+Suppress the creation of TCP
.Dv TIME_WAIT
states for connections in
which both endpoints are local.
+The default is 0.
+.Va nolocaltimewait
+is deprecated and will be removed in
+.Fx 16 .
+.Va msl_local
+can be used instead.
.It Va path_mtu_discovery
Enable Path MTU Discovery.
.It Va pcbcount
diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c
index 08673ddd1152..7c6c55909215 100644
--- a/sys/netinet/tcp_timewait.c
+++ b/sys/netinet/tcp_timewait.c
@@ -87,10 +87,28 @@
#include <security/mac/mac_framework.h>
-VNET_DEFINE_STATIC(bool, nolocaltimewait) = true;
+VNET_DEFINE_STATIC(bool, nolocaltimewait) = false;
#define V_nolocaltimewait VNET(nolocaltimewait)
-SYSCTL_BOOL(_net_inet_tcp, OID_AUTO, nolocaltimewait,
- CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nolocaltimewait), 0,
+
+static int
+sysctl_net_inet_tcp_nolocaltimewait(SYSCTL_HANDLER_ARGS)
+{
+ int error;
+ bool new;
+
+ new = V_nolocaltimewait;
+ error = sysctl_handle_bool(oidp, &new, 0, req);
+ if (error == 0 && req->newptr) {
+ V_nolocaltimewait = new;
+ gone_in(16, "net.inet.tcp.nolocaltimewait is obsolete."
+ " Use net.inet.tcp.local_msl instead.\n");
+ }
+ return (error);
+}
+
+SYSCTL_PROC(_net_inet_tcp, OID_AUTO, nolocaltimewait,
+ CTLFLAG_VNET | CTLFLAG_RW | CTLTYPE_U8,
+ &VNET_NAME(nolocaltimewait), 0, sysctl_net_inet_tcp_nolocaltimewait, "CU",
"Do not create TCP TIME_WAIT state for local connections");
static u_int
