From 3bee481639dcca8122cced273d77900d0123871d Mon Sep 17 00:00:00 2001
From: jan <jan@openbsd.org>
Date: Tue, 28 Jun 2022 09:41:24 +0000
Subject: [PATCH] ifconfig(8) return "Not supported" if you try to configure
 tso on a non-tso supported interface.

pointed out by bluhm@

OK bluhm@
---
 sys/net/if.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sys/net/if.c b/sys/net/if.c
index 8a29aec0f03..0493f1b113a 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.655 2022/06/28 08:01:40 mvs Exp $	*/
+/*	$OpenBSD: if.c,v 1.656 2022/06/28 09:41:24 jan Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -2054,6 +2054,10 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct proc *p)
 			}
 
 			splx(s);
+		} else if (!ISSET(ifp->if_capabilities, IFCAP_TSO) &&
+		    ISSET(ifr->ifr_flags, IFXF_TSO)) {
+			ifr->ifr_flags &= ~IFXF_TSO;
+			error = ENOTSUP;
 		}
 #endif
 
-- 
2.20.1