From 779e0d38dc9dbdfb6adab8e543c360bcf2d2756f Mon Sep 17 00:00:00 2001
From: jan <jan@openbsd.org>
Date: Fri, 21 Apr 2023 14:31:41 +0000
Subject: [PATCH] vlan(4) inherits TSO flags

tested by Hrvoje Popovski

with tweaks from bluhm and claudio

encouraged from deraadt
ok bluhm
---
 sys/net/if.c          |  7 ++++++-
 sys/net/if_vlan.c     | 32 +++++++++++++++++++++++++++++++-
 sys/net/if_vlan_var.h |  3 ++-
 3 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/sys/net/if.c b/sys/net/if.c
index e25fe1c03ac..b53416655e9 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.690 2023/04/18 22:01:24 mvs Exp $	*/
+/*	$OpenBSD: if.c,v 1.691 2023/04/21 14:31:41 jan Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -92,6 +92,7 @@
 #include <net/if.h>
 #include <net/if_dl.h>
 #include <net/if_types.h>
+#include <net/if_vlan_var.h>
 #include <net/route.h>
 #include <net/netisr.h>
 
@@ -3149,6 +3150,10 @@ ifsettso(struct ifnet *ifp, int on)
 	else
 		goto out;
 
+	/* Change TSO flag also on attached vlan(4)/svlan(4) interfaces. */
+	vlan_flags_from_parent(ifp, IFXF_TSO);
+
+	/* restart interface */
 	if (ISSET(ifp->if_flags, IFF_UP)) {
 		/* go down for a moment... */
 		CLR(ifp->if_flags, IFF_UP);
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 07a302b3832..7d3bef9a548 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vlan.c,v 1.211 2023/02/02 13:28:31 claudio Exp $	*/
+/*	$OpenBSD: if_vlan.c,v 1.212 2023/04/21 14:31:41 jan Exp $	*/
 
 /*
  * Copyright 1998 Massachusetts Institute of Technology
@@ -941,6 +941,9 @@ vlan_set_parent(struct vlan_softc *sc, const char *parent)
 	if (!ISSET(sc->sc_flags, IFVF_LLADDR))
 		if_setlladdr(ifp, LLADDR(ifp0->if_sadl));
 
+	/* Inherit flags from parent interface. */
+	vlan_flags_from_parent(ifp0, IFXF_TSO);
+
 put:
 	if_put(ifp0);
 	return (error);
@@ -962,6 +965,33 @@ vlan_del_parent(struct vlan_softc *sc)
 	return (0);
 }
 
+void
+vlan_flags_from_parent(struct ifnet *ifp0, int flags)
+{
+	struct ifnet *ifp;
+	struct vlan_softc *sc;
+
+	TAILQ_FOREACH(ifp, &ifnetlist, if_list) {
+		if ((sc = ifp->if_softc) == NULL)
+			continue;
+
+		if (sc->sc_type != ETHERTYPE_VLAN &&
+		    sc->sc_type != ETHERTYPE_QINQ)
+			continue;
+
+		/* vlan and tso only works with hw tagging */
+		if (!ISSET(ifp0->if_capabilities, IFCAP_VLAN_HWTAGGING))
+			CLR(flags, IFXF_TSO);
+
+		if (sc->sc_ifidx0 == ifp0->if_index) {
+			if (ISSET(ifp0->if_xflags, flags))
+				SET(ifp->if_xflags, flags);
+			else
+				CLR(ifp->if_xflags, flags);
+		}
+	}
+}
+
 int
 vlan_set_compat(struct ifnet *ifp, struct ifreq *ifr)
 {
diff --git a/sys/net/if_vlan_var.h b/sys/net/if_vlan_var.h
index 401701ea055..1e4e57bc7bf 100644
--- a/sys/net/if_vlan_var.h
+++ b/sys/net/if_vlan_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vlan_var.h,v 1.43 2021/08/19 10:22:00 dlg Exp $	*/
+/*	$OpenBSD: if_vlan_var.h,v 1.44 2023/04/21 14:31:41 jan Exp $	*/
 
 /*
  * Copyright 1998 Massachusetts Institute of Technology
@@ -49,6 +49,7 @@ struct	vlanreq {
 #ifdef _KERNEL
 struct mbuf	*vlan_input(struct ifnet *, struct mbuf *, unsigned int *);
 struct mbuf	*vlan_inject(struct mbuf *, uint16_t, uint16_t);
+void		 vlan_flags_from_parent(struct ifnet *, int);
 #endif /* _KERNEL */
 
 #endif /* _NET_IF_VLAN_VAR_H_ */
-- 
2.20.1