Add a new address cache type called sticky. On an interface marked sticky any

address learned by the bridge is made permanent, the address will not age out
and most importantly will not migrate to another interface.

This can be used to stop mac address poisoning or clients roaming in much the
same way as static entries without the hassle of preloading the table.

4 files changed, 55 insertions, 19 deletions

diff --git a/sbin/ifconfig/ifbridge.c b/sbin/ifconfig/ifbridge.c
index 3f708b2c2eb8..1100aab26b86 100644
--- a/sbin/ifconfig/ifbridge.c
+++ b/sbin/ifconfig/ifbridge.c
@@ -321,6 +321,20 @@ unsetbridge_learn(const char *val, int d, int s, const struct afswtch *afp)
 }
 
 static void
+setbridge_sticky(const char *val, int d, int s, const struct afswtch *afp)
+{
+
+	do_bridgeflag(s, val, IFBIF_STICKY,  1);
+}
+
+static void
+unsetbridge_sticky(const char *val, int d, int s, const struct afswtch *afp)
+{
+
+	do_bridgeflag(s, val, IFBIF_STICKY,  0);
+}
+
+static void
 setbridge_span(const char *val, int d, int s, const struct afswtch *afp)
 {
 	struct ifbreq req;
@@ -639,6 +653,8 @@ static struct cmd bridge_cmds[] = {
 	DEF_CMD_ARG("-discover",	unsetbridge_discover),
 	DEF_CMD_ARG("learn",		setbridge_learn),
 	DEF_CMD_ARG("-learn",		unsetbridge_learn),
+	DEF_CMD_ARG("sticky",		setbridge_sticky),
+	DEF_CMD_ARG("-sticky",		unsetbridge_sticky),
 	DEF_CMD_ARG("span",		setbridge_span),
 	DEF_CMD_ARG("-span",		unsetbridge_span),
 	DEF_CMD_ARG("stp",		setbridge_stp),
diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index 0221909bc605..018a0fae7650 100644
--- a/sbin/ifconfig/ifconfig.8
+++ b/sbin/ifconfig/ifconfig.8
@@ -1245,6 +1245,18 @@ This is the default for all interfaces added to a bridge.
 Clear the
 .Dq learning
 attribute on a member interface.
+.It Cm sticky Ar interface
+Mark an interface as a
+.Dq sticky
+interface.
+Dynamically learned address entries are treated at static once entered into
+the cache.
+Sticky entries are never aged out of the cache or replaced, even if the
+address is seen on a different interface.
+.It Cm -sticky Ar interface
+Clear the
+.Dq sticky
+attribute on a member interface.
 .It Cm span Ar interface
 Add the interface named by
 .Ar interface
diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index 83866eea081a..edf38311f10b 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -250,7 +250,7 @@ static void	bridge_broadcast(struct bridge_softc *, struct ifnet *,
 static void	bridge_span(struct bridge_softc *, struct mbuf *);
 
 static int	bridge_rtupdate(struct bridge_softc *, const uint8_t *,
-		    struct ifnet *, int, uint8_t);
+		    struct bridge_iflist *, int, uint8_t);
 static struct ifnet *bridge_rtlookup(struct bridge_softc *, const uint8_t *);
 static void	bridge_rttrim(struct bridge_softc *);
 static void	bridge_rtage(struct bridge_softc *);
@@ -1194,7 +1194,7 @@ bridge_ioctl_saddr(struct bridge_softc *sc, void *arg)
 	if (bif == NULL)
 		return (ENOENT);
 
-	error = bridge_rtupdate(sc, req->ifba_dst, bif->bif_ifp, 1,
+	error = bridge_rtupdate(sc, req->ifba_dst, bif, 1,
 	    req->ifba_flags);
 
 	return (error);
@@ -1901,7 +1901,7 @@ 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,
-		    src_if, 0, IFBAF_DYNAMIC);
+		    bif, 0, IFBAF_DYNAMIC);
 	}
 
 	if ((bif->bif_flags & IFBIF_STP) != 0 &&
@@ -2014,7 +2014,7 @@ static struct mbuf *
 bridge_input(struct ifnet *ifp, struct mbuf *m)
 {
 	struct bridge_softc *sc = ifp->if_bridge;
-	struct bridge_iflist *bif;
+	struct bridge_iflist *bif, *bif2;
 	struct ifnet *bifp;
 	struct ether_header *eh;
 	struct mbuf *mc, *mc2;
@@ -2058,7 +2058,7 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 		/* Note where to send the reply to */
 		if (bif->bif_flags & IFBIF_LEARNING)
 			(void) bridge_rtupdate(sc,
-			    eh->ether_shost, ifp, 0, IFBAF_DYNAMIC);
+			    eh->ether_shost, bif, 0, IFBAF_DYNAMIC);
 
 		/* Mark the packet as arriving on the bridge interface */
 		m->m_pkthdr.rcvif = bifp;
@@ -2140,31 +2140,31 @@ bridge_input(struct ifnet *ifp, struct mbuf *m)
 	/*
 	 * Unicast.  Make sure it's not for us.
 	 */
-	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
-		if (bif->bif_ifp->if_type == IFT_GIF)
+	LIST_FOREACH(bif2, &sc->sc_iflist, bif_next) {
+		if (bif2->bif_ifp->if_type == IFT_GIF)
 			continue;
 		/* It is destined for us. */
-		if (memcmp(IF_LLADDR(bif->bif_ifp), eh->ether_dhost,
+		if (memcmp(IF_LLADDR(bif2->bif_ifp), eh->ether_dhost,
 		    ETHER_ADDR_LEN) == 0
 #ifdef DEV_CARP
-		    || (bif->bif_ifp->if_carp 
-			&& carp_forus(bif->bif_ifp->if_carp, eh->ether_dhost))
+		    || (bif2->bif_ifp->if_carp 
+			&& carp_forus(bif2->bif_ifp->if_carp, eh->ether_dhost))
 #endif
 		    ) {
 			if (bif->bif_flags & IFBIF_LEARNING)
 				(void) bridge_rtupdate(sc,
-				    eh->ether_shost, ifp, 0, IFBAF_DYNAMIC);
-			m->m_pkthdr.rcvif = bif->bif_ifp;
+				    eh->ether_shost, bif, 0, IFBAF_DYNAMIC);
+			m->m_pkthdr.rcvif = bif2->bif_ifp;
 			BRIDGE_UNLOCK(sc);
 			return (m);
 		}
 
 		/* We just received a packet that we sent out. */
-		if (memcmp(IF_LLADDR(bif->bif_ifp), eh->ether_shost,
+		if (memcmp(IF_LLADDR(bif2->bif_ifp), eh->ether_shost,
 		    ETHER_ADDR_LEN) == 0
 #ifdef DEV_CARP
-		    || (bif->bif_ifp->if_carp 
-			&& carp_forus(bif->bif_ifp->if_carp, eh->ether_shost))
+		    || (bif2->bif_ifp->if_carp 
+			&& carp_forus(bif2->bif_ifp->if_carp, eh->ether_shost))
 #endif
 		    ) {
 			BRIDGE_UNLOCK(sc);
@@ -2315,9 +2315,10 @@ bridge_span(struct bridge_softc *sc, struct mbuf *m)
  */
 static int
 bridge_rtupdate(struct bridge_softc *sc, const uint8_t *dst,
-    struct ifnet *dst_if, int setflags, uint8_t flags)
+    struct bridge_iflist *bif, int setflags, uint8_t flags)
 {
 	struct bridge_rtnode *brt;
+	struct ifnet *dst_if = bif->bif_ifp;
 	int error;
 
 	BRIDGE_LOCK_ASSERT(sc);
@@ -2341,7 +2342,12 @@ bridge_rtupdate(struct bridge_softc *sc, const uint8_t *dst,
 		if (brt == NULL)
 			return (ENOMEM);
 
-		brt->brt_flags = IFBAF_DYNAMIC;
+		if (bif->bif_flags & IFBIF_STICKY)
+			brt->brt_flags = IFBAF_STICKY;
+		else
+			brt->brt_flags = IFBAF_DYNAMIC;
+
+		brt->brt_ifp = dst_if;
 		memcpy(brt->brt_addr, dst, ETHER_ADDR_LEN);
 
 		if ((error = bridge_rtnode_insert(sc, brt)) != 0) {
diff --git a/sys/net/if_bridgevar.h b/sys/net/if_bridgevar.h
index ff805266afb6..a5241b912eb5 100644
--- a/sys/net/if_bridgevar.h
+++ b/sys/net/if_bridgevar.h
@@ -140,8 +140,9 @@ struct ifbreq {
 #define	IFBIF_DISCOVER		0x02	/* if sends packets w/ unknown dest. */
 #define	IFBIF_STP		0x04	/* if participates in spanning tree */
 #define	IFBIF_SPAN		0x08	/* if is a span port */
+#define	IFBIF_STICKY		0x10	/* if learned addresses stick */
 
-#define	IFBIFBITS	"\020\1LEARNING\2DISCOVER\3STP\4SPAN"
+#define	IFBIFBITS	"\020\1LEARNING\2DISCOVER\3STP\4SPAN\5STICKY"
 
 /* BRDGFLUSH */
 #define	IFBF_FLUSHDYN		0x00	/* flush learned addresses only */
@@ -173,8 +174,9 @@ struct ifbareq {
 #define	IFBAF_TYPEMASK	0x03	/* address type mask */
 #define	IFBAF_DYNAMIC	0x00	/* dynamically learned address */
 #define	IFBAF_STATIC	0x01	/* static address */
+#define	IFBAF_STICKY	0x02	/* sticky address */
 
-#define	IFBAFBITS	"\020\1STATIC"
+#define	IFBAFBITS	"\020\1STATIC\2STICKY"
 
 /*
  * Address list structure.