From: jan@openbsd.org
Subject: trunk/aggr(4): turn off lro if bridged
To: tech@openbsd.org
Date: Fri, 3 May 2024 21:32:05 +0200

Hi,

When aggr(4) or trunk(4) attaches to bridged, they have to forward the
turn off LRO call to there trunkports.  I don't find a way to do this
like the existing code for vlan(4) and friends.  Thus, I have to
introduce a new ioctl for this kind of action.

With this diff a user no longer needs to disable tcplro manually when
working with bridged trunk(4) or aggr(4) interfaces.

ok?

bye,
Jan

Index: net/if.c
===================================================================
RCS file: /cvs/src/sys/net/if.c,v
diff -u -p -r1.718 if.c
--- net/if.c	6 Feb 2024 00:18:53 -0000	1.718
+++ net/if.c	3 May 2024 18:31:40 -0000
@@ -140,6 +140,10 @@
 
 #include <sys/device.h>
 
+#include <crypto/siphash.h>
+#include <net/if_media.h>
+#include <net/if_trunk.h>
+
 void	if_attachsetup(struct ifnet *);
 void	if_attach_common(struct ifnet *);
 void	if_remove(struct ifnet *);
@@ -3247,6 +3251,10 @@ ifsetlro(struct ifnet *ifp, int on)
 	int s = splnet();
 	struct if_parent parent;
 
+	/*
+	 * Forward ifsetlro() call to parents of bpe(4), gre(4), pfsync(4),
+	 * vlan(4) and vxlan(4).
+	 */
 	memset(&parent, 0, sizeof(parent));
 	if ((*ifp->if_ioctl)(ifp, SIOCGIFPARENT, (caddr_t)&parent) != -1) {
 		struct ifnet *ifp0 = if_unit(parent.ifp_parent);
@@ -3256,6 +3264,11 @@ ifsetlro(struct ifnet *ifp, int on)
 			if_put(ifp0);
 		}
 	}
+
+	/*
+	 * Forward ifsetlro() call to all trunkports of trunk(4) and aggr(4).
+	 */
+	(*ifp->if_ioctl)(ifp, SIOCSTRUNKPORTLRO, (caddr_t)&on);
 
 	if (!ISSET(ifp->if_capabilities, IFCAP_LRO)) {
 		error = ENOTSUP;
Index: net/if_aggr.c
===================================================================
RCS file: /cvs/src/sys/net/if_aggr.c,v
diff -u -p -r1.45 if_aggr.c
--- net/if_aggr.c	18 Mar 2024 06:14:50 -0000	1.45
+++ net/if_aggr.c	3 May 2024 19:18:27 -0000
@@ -833,6 +833,7 @@ aggr_ioctl(struct ifnet *ifp, u_long cmd
 {
 	struct aggr_softc *sc = ifp->if_softc;
 	struct ifreq *ifr = (struct ifreq *)data;
+	struct aggr_port *p;
 	int error = 0;
 
 	if (sc->sc_dead)
@@ -897,6 +898,10 @@ aggr_ioctl(struct ifnet *ifp, u_long cmd
 
 		error = aggr_add_port(sc, (struct trunk_reqport *)data);
 		break;
+	case SIOCSTRUNKPORTLRO:
+		TAILQ_FOREACH(p, &sc->sc_ports, p_entry)
+			ifsetlro(p->p_ifp0, *(int *)data);
+		break;
 	case SIOCSTRUNKDELPORT:
 		error = suser(curproc);
 		if (error != 0)
@@ -1184,6 +1189,10 @@ aggr_add_port(struct aggr_softc *sc, con
 		if (error != 0)
 			goto unmtu;
 	}
+
+	/* Turn off LRO if we are bridged. */
+	if (ether_brport_isset(ifp))
+		ifsetlro(ifp0, 0);
 
 	TAILQ_FOREACH(ma, &sc->sc_multiaddrs, m_entry) {
 		if (aggr_multi(sc, p, ma, SIOCADDMULTI) != 0) {
Index: net/if_trunk.c
===================================================================
RCS file: /cvs/src/sys/net/if_trunk.c,v
diff -u -p -r1.154 if_trunk.c
--- net/if_trunk.c	23 Dec 2023 10:52:54 -0000	1.154
+++ net/if_trunk.c	3 May 2024 19:12:59 -0000
@@ -334,6 +334,10 @@ trunk_port_create(struct trunk_softc *tr
 		}
 	}
 
+	/* Turn off LRO if we are bridged. */
+	if (ether_brport_isset(&tr->tr_ac.ac_if))
+		ifsetlro(ifp, 0);
+
 	/* Change the interface type */
 	tp->tp_iftype = ifp->if_type;
 	ifp->if_type = IFT_IEEE8023ADLAG;
@@ -783,6 +787,10 @@ trunk_ioctl(struct ifnet *ifp, u_long cm
 				    tro->to_lacpopts.lacp_ifqprio;
 				break;
 		}
+		break;
+	case SIOCSTRUNKPORTLRO:
+		SLIST_FOREACH(tp, &tr->tr_ports, tp_entries)
+			ifsetlro(tp->tp_if, *(int *)data);
 		break;
 	case SIOCGTRUNKPORT:
 		if (rp->rp_portname[0] == '\0' ||
Index: net/if_trunk.h
===================================================================
RCS file: /cvs/src/sys/net/if_trunk.h,v
diff -u -p -r1.30 if_trunk.h
--- net/if_trunk.h	22 Jul 2020 02:16:02 -0000	1.30
+++ net/if_trunk.h	3 May 2024 18:14:28 -0000
@@ -150,6 +150,7 @@ struct trunk_opts {
 
 #define SIOCGTRUNKOPTS		_IOWR('i', 145, struct trunk_opts)
 #define SIOCSTRUNKOPTS		 _IOW('i', 146, struct trunk_opts)
+#define SIOCSTRUNKPORTLRO	 _IOW('i', 147, int)
 
 #ifdef _KERNEL
 /*