From 1a9be79712301e20fcea43efea0745b6d6b7ffd2 Mon Sep 17 00:00:00 2001
From: jan <jan@openbsd.org>
Date: Sun, 9 Jun 2024 16:25:27 +0000
Subject: [PATCH] Introduce IFCAP_VLAN_HWOFFLOAD for vio(4).

Add IFCAP_VLAN_HWOFFLOAD to signal hardware like vio(4) can handle
checksum or TSO offloading with inline VLAN tags.

tested by Mark Patruck, sf@ and bluhm@

ok sf@ and bluhm@
---
 sbin/ifconfig/ifconfig.8 |  7 +++++--
 sbin/ifconfig/ifconfig.c |  4 ++--
 sys/dev/pv/if_vio.c      |  8 ++++++--
 sys/net/if.h             |  3 ++-
 sys/net/if_vlan.c        | 10 +++++++---
 5 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index bc92b15c567..121bb1e8f75 100644
--- a/sbin/ifconfig/ifconfig.8
+++ b/sbin/ifconfig/ifconfig.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ifconfig.8,v 1.399 2024/01/11 17:22:04 jan Exp $
+.\"	$OpenBSD: ifconfig.8,v 1.400 2024/06/09 16:25:27 jan Exp $
 .\"	$NetBSD: ifconfig.8,v 1.11 1996/01/04 21:27:29 pk Exp $
 .\"     $FreeBSD: ifconfig.8,v 1.16 1998/02/01 07:03:29 steve Exp $
 .\"
@@ -31,7 +31,7 @@
 .\"
 .\"     @(#)ifconfig.8	8.4 (Berkeley) 6/1/94
 .\"
-.Dd $Mdocdate: January 11 2024 $
+.Dd $Mdocdate: June 9 2024 $
 .Dt IFCONFIG 8
 .Os
 .Sh NAME
@@ -294,6 +294,9 @@ tag.
 On transmit, the device can add the
 .Xr vlan 4
 tag.
+.It Sy VLAN_HWOFFLOAD
+On transmit, the device can handle checksum or TSO offload without
+.Sy VLAN_HWTAGGING .
 .It Sy WOL
 The device supports Wake on LAN (WoL).
 .It Sy hardmtu
diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
index 2c257a430a2..3e44dce7120 100644
--- a/sbin/ifconfig/ifconfig.c
+++ b/sbin/ifconfig/ifconfig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ifconfig.c,v 1.472 2024/05/18 02:44:22 jsg Exp $	*/
+/*	$OpenBSD: ifconfig.c,v 1.473 2024/06/09 16:25:27 jan Exp $	*/
 /*	$NetBSD: ifconfig.c,v 1.40 1997/10/01 02:19:43 enami Exp $	*/
 
 /*
@@ -125,7 +125,7 @@
 
 #define HWFEATURESBITS							\
 	"\024\1CSUM_IPv4\2CSUM_TCPv4\3CSUM_UDPv4"			\
-	"\5VLAN_MTU\6VLAN_HWTAGGING\10CSUM_TCPv6"			\
+	"\5VLAN_MTU\6VLAN_HWTAGGING\7VLAN_HWOFFLOAD\10CSUM_TCPv6"	\
 	"\11CSUM_UDPv6\15TSOv4\16TSOv6\17LRO\20WOL"
 
 struct ifencap {
diff --git a/sys/dev/pv/if_vio.c b/sys/dev/pv/if_vio.c
index 8ce83ed0575..9451796816f 100644
--- a/sys/dev/pv/if_vio.c
+++ b/sys/dev/pv/if_vio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vio.c,v 1.37 2024/06/04 09:51:52 jan Exp $	*/
+/*	$OpenBSD: if_vio.c,v 1.38 2024/06/09 16:25:28 jan Exp $	*/
 
 /*
  * Copyright (c) 2012 Stefan Fritsch, Alexander Fiveg.
@@ -604,7 +604,11 @@ vio_attach(struct device *parent, struct device *self, void *aux)
 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
 	ifp->if_start = vio_start;
 	ifp->if_ioctl = vio_ioctl;
-	ifp->if_capabilities = IFCAP_VLAN_MTU;
+	ifp->if_capabilities = 0;
+#if NVLAN > 0
+	ifp->if_capabilities |= IFCAP_VLAN_MTU;
+	ifp->if_capabilities |= IFCAP_VLAN_HWOFFLOAD;
+#endif
 	if (virtio_has_feature(vsc, VIRTIO_NET_F_CSUM))
 		ifp->if_capabilities |= IFCAP_CSUM_TCPv4|IFCAP_CSUM_UDPv4|
 		    IFCAP_CSUM_TCPv6|IFCAP_CSUM_UDPv6;
diff --git a/sys/net/if.h b/sys/net/if.h
index ae50958ee5a..8552fff022c 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.h,v 1.216 2024/04/11 15:08:18 bluhm Exp $	*/
+/*	$OpenBSD: if.h,v 1.217 2024/06/09 16:25:28 jan Exp $	*/
 /*	$NetBSD: if.h,v 1.23 1996/05/07 02:40:27 thorpej Exp $	*/
 
 /*
@@ -249,6 +249,7 @@ struct if_status_description {
 #define	IFCAP_CSUM_UDPv4	0x00000004	/* can do IPv4/UDP csum */
 #define	IFCAP_VLAN_MTU		0x00000010	/* VLAN-compatible MTU */
 #define	IFCAP_VLAN_HWTAGGING	0x00000020	/* hardware VLAN tag support */
+#define	IFCAP_VLAN_HWOFFLOAD	0x00000040	/* hw offload w/ inline tag */
 #define	IFCAP_CSUM_TCPv6	0x00000080	/* can do IPv6/TCP checksums */
 #define	IFCAP_CSUM_UDPv6	0x00000100	/* can do IPv6/UDP checksums */
 #define	IFCAP_TSOv4		0x00001000	/* IPv4/TCP segment offload */
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 9915a94390c..9a0414f1bc6 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vlan.c,v 1.218 2023/12/23 10:52:54 bluhm Exp $	*/
+/*	$OpenBSD: if_vlan.c,v 1.219 2024/06/09 16:25:28 jan Exp $	*/
 
 /*
  * Copyright 1998 Massachusetts Institute of Technology
@@ -523,7 +523,7 @@ vlan_up(struct vlan_softc *sc)
 	/*
 	 * Note: In cases like vio(4) and em(4) where the offsets of the
 	 * csum can be freely defined, we could actually do csum offload
-	 * for VLAN and QINQ packets.
+	 * for QINQ packets.
 	 */
 	if (sc->sc_type != ETHERTYPE_VLAN) {
 		/*
@@ -531,10 +531,14 @@ vlan_up(struct vlan_softc *sc)
 		 * ethernet type (0x8100).
 		 */
 		ifp->if_capabilities = 0;
-	} else if (ISSET(ifp0->if_capabilities, IFCAP_VLAN_HWTAGGING)) {
+	} else if (ISSET(ifp0->if_capabilities, IFCAP_VLAN_HWTAGGING) ||
+	    ISSET(ifp0->if_capabilities, IFCAP_VLAN_HWOFFLOAD)) {
 		/*
 		 * Chips that can do hardware-assisted VLAN encapsulation, can
 		 * calculate the correct checksum for VLAN tagged packets.
+		 *
+		 * Hardware which does checksum offloading, but not VLAN tag
+		 * injection, have to set IFCAP_VLAN_HWOFFLOAD.
 		 */
 		ifp->if_capabilities = ifp0->if_capabilities &
 		    (IFCAP_CSUM_MASK | IFCAP_TSOv4 | IFCAP_TSOv6);
-- 
2.20.1