Add a bridge interface flag called PRIVATE where any private port can not

communicate with another private port.

All unicast/broadcast/multicast layer2 traffic is blocked so it works much the
same way as using firewall rules but scales better and is generally easier as
firewall packages usually do not allow ARP blocking.

An example usage would be having a number of customers on separate vlans
bridged with a server network. All the vlans are marked private, they can all
communicate with the server network unhindered, but can not exchange any
traffic whatsoever with each other.

Approved by:	re (rwatson)

1 files changed, 37 insertions, 33 deletions

diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index 3f0cabf..6c96cbb 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -243,7 +243,8 @@ static void	bridge_enqueue(struct bridge_softc *, struct ifnet *,
 		    struct mbuf *);
 static void	bridge_rtdelete(struct bridge_softc *, struct ifnet *ifp, int);
 
-static void	bridge_forward(struct bridge_softc *, struct mbuf *m);
+static void	bridge_forward(struct bridge_softc *, struct bridge_iflist *,
+		    struct mbuf *m);
 
 static void	bridge_timer(void *);
 
@@ -1873,9 +1874,10 @@ bridge_start(struct ifnet *ifp)
  *	NOTE: Releases the lock on return.
  */
 static void
-bridge_forward(struct bridge_softc *sc, struct mbuf *m)
+bridge_forward(struct bridge_softc *sc, struct bridge_iflist *sbif,
+    struct mbuf *m)
 {
-	struct bridge_iflist *bif;
+	struct bridge_iflist *dbif;
 	struct ifnet *src_if, *dst_if, *ifp;
 	struct ether_header *eh;
 	uint16_t vlan;
@@ -1887,19 +1889,8 @@ bridge_forward(struct bridge_softc *sc, struct mbuf *m)
 	sc->sc_ifp->if_ibytes += m->m_pkthdr.len;
 	vlan = VLANTAGOF(m);
 
-	/*
-	 * Look up the bridge_iflist.
-	 */
-	bif = bridge_lookup_member_if(sc, src_if);
-	if (bif == NULL) {
-		/* Interface is not a bridge member (anymore?) */
-		BRIDGE_UNLOCK(sc);
-		m_freem(m);
-		return;
-	}
-
-	if ((bif->bif_flags & IFBIF_STP) &&
-	    bif->bif_stp.bp_state == BSTP_IFSTATE_DISCARDING) {
+	if ((sbif->bif_flags & IFBIF_STP) &&
+	    sbif->bif_stp.bp_state == BSTP_IFSTATE_DISCARDING) {
 		BRIDGE_UNLOCK(sc);
 		m_freem(m);
 		return;
@@ -1912,7 +1903,7 @@ bridge_forward(struct bridge_softc *sc, struct mbuf *m)
 	 * address is valid and not multicast, record
 	 * the address.
 	 */
-	if ((bif->bif_flags & IFBIF_LEARNING) != 0 &&
+	if ((sbif->bif_flags & IFBIF_LEARNING) != 0 &&
 	    ETHER_IS_MULTICAST(eh->ether_shost) == 0 &&
 	    (eh->ether_shost[0] == 0 &&
 	     eh->ether_shost[1] == 0 &&
@@ -1921,11 +1912,11 @@ bridge_forward(struct bridge_softc *sc, struct mbuf *m)
 	     eh->ether_shost[4] == 0 &&
 	     eh->ether_shost[5] == 0) == 0) {
 		(void) bridge_rtupdate(sc, eh->ether_shost, vlan,
-		    bif, 0, IFBAF_DYNAMIC);
+		    sbif, 0, IFBAF_DYNAMIC);
 	}
 
-	if ((bif->bif_flags & IFBIF_STP) != 0 &&
-	    bif->bif_stp.bp_state == BSTP_IFSTATE_LEARNING) {
+	if ((sbif->bif_flags & IFBIF_STP) != 0 &&
+	    sbif->bif_stp.bp_state == BSTP_IFSTATE_LEARNING) {
 		m_freem(m);
 		BRIDGE_UNLOCK(sc);
 		return;
@@ -1993,16 +1984,23 @@ bridge_forward(struct bridge_softc *sc, struct mbuf *m)
 		m_freem(m);
 		return;
 	}
-	bif = bridge_lookup_member_if(sc, dst_if);
-	if (bif == NULL) {
+	dbif = bridge_lookup_member_if(sc, dst_if);
+	if (dbif == NULL) {
 		/* Not a member of the bridge (anymore?) */
 		BRIDGE_UNLOCK(sc);
 		m_freem(m);
 		return;
 	}
 
-	if ((bif->bif_flags & IFBIF_STP) &&
-	    bif->bif_stp.bp_state == BSTP_IFSTATE_DISCARDING) {
+	/* Private segments can not talk to each other */
+	if (sbif->bif_flags & dbif->bif_flags & IFBIF_PRIVATE) {
+		BRIDGE_UNLOCK(sc);
+		m_freem(m);
+		return;
+	}
+
+	if ((dbif->bif_flags & IFBIF_STP) &&
+	    dbif->bif_stp.bp_state == BSTP_IFSTATE_DISCARDING) {
 		BRIDGE_UNLOCK(sc);
 		m_freem(m);
 		return;
@@ -2122,7 +2120,7 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 		}
 
 		/* Perform the bridge forwarding function with the copy. */
-		bridge_forward(sc, mc);
+		bridge_forward(sc, bif, mc);
 
 		/*
 		 * Reinject the mbuf as arriving on the bridge so we have a
@@ -2210,7 +2208,7 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 #undef GRAB_OUR_PACKETS
 
 	/* Perform the bridge forwarding function. */
-	bridge_forward(sc, m);
+	bridge_forward(sc, bif, m);
 
 	return (NULL);
 }
@@ -2228,11 +2226,13 @@ static void
 bridge_broadcast(struct bridge_softc *sc, struct ifnet *src_if,
     struct mbuf *m, int runfilt)
 {
-	struct bridge_iflist *bif;
+	struct bridge_iflist *dbif, *sbif;
 	struct mbuf *mc;
 	struct ifnet *dst_if;
 	int error = 0, used = 0, i;
 
+	sbif = bridge_lookup_member_if(sc, src_if);
+
 	BRIDGE_LOCK2REF(sc, error);
 	if (error) {
 		m_freem(m);
@@ -2251,23 +2251,27 @@ bridge_broadcast(struct bridge_softc *sc, struct ifnet *src_if,
 			goto out;
 	}
 
-	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
-		dst_if = bif->bif_ifp;
+	LIST_FOREACH(dbif, &sc->sc_iflist, bif_next) {
+		dst_if = dbif->bif_ifp;
 		if (dst_if == src_if)
 			continue;
 
-		if ((bif->bif_flags & IFBIF_STP) &&
-		    bif->bif_stp.bp_state == BSTP_IFSTATE_DISCARDING)
+		/* Private segments can not talk to each other */
+		if (sbif && (sbif->bif_flags & dbif->bif_flags & IFBIF_PRIVATE))
+			continue;
+
+		if ((dbif->bif_flags & IFBIF_STP) &&
+		    dbif->bif_stp.bp_state == BSTP_IFSTATE_DISCARDING)
 			continue;
 
-		if ((bif->bif_flags & IFBIF_DISCOVER) == 0 &&
+		if ((dbif->bif_flags & IFBIF_DISCOVER) == 0 &&
 		    (m->m_flags & (M_BCAST|M_MCAST)) == 0)
 			continue;
 
 		if ((dst_if->if_drv_flags & IFF_DRV_RUNNING) == 0)
 			continue;
 
-		if (LIST_NEXT(bif, bif_next) == NULL) {
+		if (LIST_NEXT(dbif, bif_next) == NULL) {
 			mc = m;
 			used = 1;
 		} else {