bridging vlan problem

[Andrew Thompson]

Hi,


This problem has always existed but now in RELENG_7+ since the vlan tag
is always stripped on the incoming packet its a little more obvious.

The bridging output function puts the mbuf directly on the interfaces
send queue so only network cards with VLAN_HWTAGGING will properly
re-tag any outgoing vlan frames.

The attached patch fixes this as well as putting the common vlan
encapsulation code in to ether_vlanencap().

Any comments please, I want to commit this soon so I have more chance of
getting it into 7.0


Andrew
-------------- next part --------------
Index: ethernet.h
===================================================================
RCS file: /home/ncvs/src/sys/net/ethernet.h,v
retrieving revision 1.32
diff -u -p -r1.32 ethernet.h
--- ethernet.h	29 May 2007 12:40:45 -0000	1.32
+++ ethernet.h	16 Oct 2007 01:18:28 -0000
@@ -386,6 +386,7 @@ extern	int  ether_output_frame(struct if
 extern	char *ether_sprintf(const u_int8_t *);
 void	ether_vlan_mtap(struct bpf_if *, struct mbuf *,
 	    void *, u_int);
+struct mbuf * ether_vlanencap(struct mbuf *, int);
 
 #else /* _KERNEL */
 
Index: if_bridge.c
===================================================================
RCS file: /home/ncvs/src/sys/net/if_bridge.c,v
retrieving revision 1.103
diff -u -p -r1.103 if_bridge.c
--- if_bridge.c	16 Sep 2007 21:09:15 -0000	1.103
+++ if_bridge.c	16 Oct 2007 04:03:43 -0000
@@ -1653,7 +1653,23 @@ bridge_enqueue(struct bridge_softc *sc, 
 	for (; m; m = m0) {
 		m0 = m->m_nextpkt;
 		m->m_nextpkt = NULL;
-		
+
+		/*
+		 * If underlying interface can not do VLAN tag insertion itself
+		 * then attach a packet tag that holds it.
+		 */
+		if ((m->m_flags & M_VLANTAG) &&
+		    (dst_ifp->if_capenable & IFCAP_VLAN_HWTAGGING) == 0) {
+			m = ether_vlanencap(m, m->m_pkthdr.ether_vtag);
+			if (m == NULL) {
+				if_printf(dst_ifp,
+				    "unable to prepend VLAN header\n");
+				dst_ifp->if_oerrors++;
+				continue;
+			}
+			m->m_flags &= ~M_VLANTAG;
+		}
+
 		if (err == 0)
 			IFQ_ENQUEUE(&dst_ifp->if_snd, m, err);
 	}
Index: if_ethersubr.c
===================================================================
RCS file: /home/ncvs/src/sys/net/if_ethersubr.c,v
retrieving revision 1.236
diff -u -p -r1.236 if_ethersubr.c
--- if_ethersubr.c	14 Sep 2007 06:57:28 -0000	1.236
+++ if_ethersubr.c	16 Oct 2007 04:03:58 -0000
@@ -1249,5 +1249,33 @@ ether_vlan_mtap(struct bpf_if *bp, struc
 	m->m_data -= sizeof(struct ether_header);
 }
 
+struct mbuf *
+ether_vlanencap(struct mbuf *m, int tag)
+{
+	struct ether_vlan_header *evl;
+
+	M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_DONTWAIT);
+	if (m == NULL)
+		return (NULL);
+	/* M_PREPEND takes care of m_len, m_pkthdr.len for us */
+
+	if (m->m_len < sizeof(*evl)) {
+		m = m_pullup(m, sizeof(*evl));
+		if (m == NULL)
+			return (NULL);
+	}
+
+	/*
+	 * Transform the Ethernet header into an Ethernet header
+	 * with 802.1Q encapsulation.
+	 */
+	evl = mtod(m, struct ether_vlan_header *);
+	bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN,
+	    (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN);
+	evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
+	evl->evl_tag = htons(tag);
+	return (m);
+}
+
 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
 MODULE_VERSION(ether, 1);
Index: if_vlan.c
===================================================================
RCS file: /home/ncvs/src/sys/net/if_vlan.c,v
retrieving revision 1.124
diff -u -p -r1.124 if_vlan.c
--- if_vlan.c	19 Mar 2007 18:01:39 -0000	1.124
+++ if_vlan.c	16 Oct 2007 04:03:50 -0000
@@ -850,40 +850,13 @@ vlan_start(struct ifnet *ifp)
 			m->m_pkthdr.ether_vtag = ifv->ifv_tag;
 			m->m_flags |= M_VLANTAG;
 		} else {
-			struct ether_vlan_header *evl;
-
-			M_PREPEND(m, ifv->ifv_encaplen, M_DONTWAIT);
+			m = ether_vlanencap(m, ifv->ifv_tag);
 			if (m == NULL) {
 				if_printf(ifp,
 				    "unable to prepend VLAN header\n");
 				ifp->if_oerrors++;
 				continue;
 			}
-			/* M_PREPEND takes care of m_len, m_pkthdr.len for us */
-
-			if (m->m_len < sizeof(*evl)) {
-				m = m_pullup(m, sizeof(*evl));
-				if (m == NULL) {
-					if_printf(ifp,
-					    "cannot pullup VLAN header\n");
-					ifp->if_oerrors++;
-					continue;
-				}
-			}
-
-			/*
-			 * Transform the Ethernet header into an Ethernet header
-			 * with 802.1Q encapsulation.
-			 */
-			evl = mtod(m, struct ether_vlan_header *);
-			bcopy((char *)evl + ifv->ifv_encaplen,
-			      (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN);
-			evl->evl_encap_proto = htons(ifv->ifv_proto);
-			evl->evl_tag = htons(ifv->ifv_tag);
-#ifdef DEBUG
-			printf("%s: %*D\n", __func__, (int)sizeof(*evl),
-			    (unsigned char *)evl, ":");
-#endif
 		}
 
 		/*