Add if_bridge, which provides more advanced Ethernet bridging and 802.1d

spanning tree support.

Based on Jason Wright's bridge driver from OpenBSD, and modified by Jason R.
Thorpe in NetBSD.

Reviewed by:	mlaier, bms, green
Silence from:	-net
Approved by:	mlaier (mentor)
Obtained from:	NetBSD

1 files changed, 1174 insertions, 0 deletions

diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
new file mode 100644
index 0000000..a1a487b
--- /dev/null
+++ b/sys/net/bridgestp.c
@@ -0,0 +1,1174 @@
+/*	$NetBSD: bridgestp.c,v 1.5 2003/11/28 08:56:48 keihan Exp $	*/
+
+/*
+ * Copyright (c) 2000 Jason L. Wright (jason@thought.net)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Jason L. Wright
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * OpenBSD: bridgestp.c,v 1.5 2001/03/22 03:48:29 jason Exp
+ */
+
+/*
+ * Implementation of the spanning tree protocol as defined in
+ * ISO/IEC Final DIS 15802-3 (IEEE P802.1D/D17), May 25, 1998.
+ * (In English: IEEE 802.1D, Draft 17, 1998)
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/sockio.h>
+#include <sys/kernel.h>
+#include <sys/callout.h>
+#include <sys/proc.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/condvar.h>
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/if_types.h>
+#include <net/if_llc.h>
+#include <net/if_media.h>
+
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
+#include <netinet/if_ether.h>
+#include <net/if_bridgevar.h>
+
+#define sc_if ifb_ac.ac_if
+
+/* BPDU message types */
+#define	BSTP_MSGTYPE_CFG	0x00		/* Configuration */
+#define	BSTP_MSGTYPE_TCN	0x80		/* Topology chg notification */
+
+/* BPDU flags */
+#define	BSTP_FLAG_TC		0x01		/* Topology change */
+#define	BSTP_FLAG_TCA		0x80		/* Topology change ack */
+
+#define	BSTP_MESSAGE_AGE_INCR	(1 * 256)	/* in 256ths of a second */
+#define	BSTP_TICK_VAL		(1 * 256)	/* in 256ths of a second */
+
+/*
+ * Because BPDU's do not make nicely aligned structures, two different
+ * declarations are used: bstp_?bpdu (wire representation, packed) and
+ * bstp_*_unit (internal, nicely aligned version).
+ */
+
+/* configuration bridge protocol data unit */
+struct bstp_cbpdu {
+	uint8_t		cbu_dsap;		/* LLC: destination sap */
+	uint8_t		cbu_ssap;		/* LLC: source sap */
+	uint8_t		cbu_ctl;		/* LLC: control */
+	uint16_t	cbu_protoid;		/* protocol id */
+	uint8_t		cbu_protover;		/* protocol version */
+	uint8_t		cbu_bpdutype;		/* message type */
+	uint8_t		cbu_flags;		/* flags (below) */
+
+	/* root id */
+	uint16_t	cbu_rootpri;		/* root priority */
+	uint8_t	cbu_rootaddr[6];	/* root address */
+
+	uint32_t	cbu_rootpathcost;	/* root path cost */
+
+	/* bridge id */
+	uint16_t	cbu_bridgepri;		/* bridge priority */
+	uint8_t		cbu_bridgeaddr[6];	/* bridge address */
+
+	uint16_t	cbu_portid;		/* port id */
+	uint16_t	cbu_messageage;		/* current message age */
+	uint16_t	cbu_maxage;		/* maximum age */
+	uint16_t	cbu_hellotime;		/* hello time */
+	uint16_t	cbu_forwarddelay;	/* forwarding delay */
+} __attribute__((__packed__));
+
+/* topology change notification bridge protocol data unit */
+struct bstp_tbpdu {
+	uint8_t		tbu_dsap;		/* LLC: destination sap */
+	uint8_t		tbu_ssap;		/* LLC: source sap */
+	uint8_t		tbu_ctl;		/* LLC: control */
+	uint16_t	tbu_protoid;		/* protocol id */
+	uint8_t		tbu_protover;		/* protocol version */
+	uint8_t		tbu_bpdutype;		/* message type */
+} __attribute__((__packed__));
+
+const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
+
+void	bstp_initialize_port(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_ifupdstatus(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_enable_port(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_disable_port(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_enable_change_detection(struct bridge_iflist *);
+void	bstp_disable_change_detection(struct bridge_iflist *);
+int	bstp_root_bridge(struct bridge_softc *sc);
+int	bstp_supersedes_port_info(struct bridge_softc *,
+	    struct bridge_iflist *, struct bstp_config_unit *);
+int	bstp_designated_port(struct bridge_softc *, struct bridge_iflist *);
+int	bstp_designated_for_some_port(struct bridge_softc *);
+void	bstp_transmit_config(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_transmit_tcn(struct bridge_softc *);
+void	bstp_received_config_bpdu(struct bridge_softc *,
+	    struct bridge_iflist *, struct bstp_config_unit *);
+void	bstp_received_tcn_bpdu(struct bridge_softc *, struct bridge_iflist *,
+	    struct bstp_tcn_unit *);
+void	bstp_record_config_information(struct bridge_softc *,
+	    struct bridge_iflist *, struct bstp_config_unit *);
+void	bstp_record_config_timeout_values(struct bridge_softc *,
+	    struct bstp_config_unit *);
+void	bstp_config_bpdu_generation(struct bridge_softc *);
+void	bstp_send_config_bpdu(struct bridge_softc *, struct bridge_iflist *,
+	    struct bstp_config_unit *);
+void	bstp_configuration_update(struct bridge_softc *);
+void	bstp_root_selection(struct bridge_softc *);
+void	bstp_designated_port_selection(struct bridge_softc *);
+void	bstp_become_designated_port(struct bridge_softc *,
+	    struct bridge_iflist *);
+void	bstp_port_state_selection(struct bridge_softc *);
+void	bstp_make_forwarding(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_make_blocking(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_set_port_state(struct bridge_iflist *, uint8_t);
+void	bstp_set_bridge_priority(struct bridge_softc *, uint64_t);
+void	bstp_set_port_priority(struct bridge_softc *, struct bridge_iflist *,
+	    uint16_t);
+void	bstp_set_path_cost(struct bridge_softc *, struct bridge_iflist *,
+	    uint32_t);
+void	bstp_topology_change_detection(struct bridge_softc *);
+void	bstp_topology_change_acknowledged(struct bridge_softc *);
+void	bstp_acknowledge_topology_change(struct bridge_softc *,
+	    struct bridge_iflist *);
+
+void	bstp_tick(void *);
+void	bstp_timer_start(struct bridge_timer *, uint16_t);
+void	bstp_timer_stop(struct bridge_timer *);
+int	bstp_timer_expired(struct bridge_timer *, uint16_t);
+
+void	bstp_hold_timer_expiry(struct bridge_softc *, struct bridge_iflist *);
+void	bstp_message_age_timer_expiry(struct bridge_softc *,
+	    struct bridge_iflist *);
+void	bstp_forward_delay_timer_expiry(struct bridge_softc *,
+	    struct bridge_iflist *);
+void	bstp_topology_change_timer_expiry(struct bridge_softc *);
+void	bstp_tcn_timer_expiry(struct bridge_softc *);
+void	bstp_hello_timer_expiry(struct bridge_softc *);
+
+void
+bstp_transmit_config(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	if (bif->bif_hold_timer.active) {
+		bif->bif_config_pending = 1;
+		return;
+	}
+
+	bif->bif_config_bpdu.cu_message_type = BSTP_MSGTYPE_CFG;
+	bif->bif_config_bpdu.cu_rootid = sc->sc_designated_root;
+	bif->bif_config_bpdu.cu_root_path_cost = sc->sc_root_path_cost;
+	bif->bif_config_bpdu.cu_bridge_id = sc->sc_bridge_id;
+	bif->bif_config_bpdu.cu_port_id = bif->bif_port_id;
+
+	if (bstp_root_bridge(sc))
+		bif->bif_config_bpdu.cu_message_age = 0;
+	else
+		bif->bif_config_bpdu.cu_message_age =
+		    sc->sc_root_port->bif_message_age_timer.value +
+		    BSTP_MESSAGE_AGE_INCR;
+
+	bif->bif_config_bpdu.cu_max_age = sc->sc_max_age;
+	bif->bif_config_bpdu.cu_hello_time = sc->sc_hello_time;
+	bif->bif_config_bpdu.cu_forward_delay = sc->sc_forward_delay;
+	bif->bif_config_bpdu.cu_topology_change_acknowledgment
+	    = bif->bif_topology_change_acknowledge;
+	bif->bif_config_bpdu.cu_topology_change = sc->sc_topology_change;
+
+	if (bif->bif_config_bpdu.cu_message_age < sc->sc_max_age) {
+		bif->bif_topology_change_acknowledge = 0;
+		bif->bif_config_pending = 0;
+		bstp_send_config_bpdu(sc, bif, &bif->bif_config_bpdu);
+		bstp_timer_start(&bif->bif_hold_timer, 0);
+	}
+}
+
+void
+bstp_send_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
+    struct bstp_config_unit *cu)
+{
+	struct ifnet *ifp;
+	struct mbuf *m;
+	struct ether_header *eh;
+	struct bstp_cbpdu bpdu;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	ifp = bif->bif_ifp;
+
+	if ((ifp->if_flags & IFF_RUNNING) == 0)
+		return;
+
+	MGETHDR(m, M_DONTWAIT, MT_DATA);
+	if (m == NULL)
+		return;
+
+	eh = mtod(m, struct ether_header *);
+
+	m->m_pkthdr.rcvif = ifp;
+	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
+	m->m_len = m->m_pkthdr.len;
+
+	bpdu.cbu_ssap = bpdu.cbu_dsap = LLC_8021D_LSAP;
+	bpdu.cbu_ctl = LLC_UI;
+	bpdu.cbu_protoid = htons(0);
+	bpdu.cbu_protover = 0;
+	bpdu.cbu_bpdutype = cu->cu_message_type;
+	bpdu.cbu_flags = (cu->cu_topology_change ? BSTP_FLAG_TC : 0) |
+	    (cu->cu_topology_change_acknowledgment ? BSTP_FLAG_TCA : 0);
+
+	bpdu.cbu_rootpri = htons(cu->cu_rootid >> 48);
+	bpdu.cbu_rootaddr[0] = cu->cu_rootid >> 40;
+	bpdu.cbu_rootaddr[1] = cu->cu_rootid >> 32;
+	bpdu.cbu_rootaddr[2] = cu->cu_rootid >> 24;
+	bpdu.cbu_rootaddr[3] = cu->cu_rootid >> 16;
+	bpdu.cbu_rootaddr[4] = cu->cu_rootid >> 8;
+	bpdu.cbu_rootaddr[5] = cu->cu_rootid >> 0;
+
+	bpdu.cbu_rootpathcost = htonl(cu->cu_root_path_cost);
+
+	bpdu.cbu_bridgepri = htons(cu->cu_rootid >> 48);
+	bpdu.cbu_bridgeaddr[0] = cu->cu_rootid >> 40;
+	bpdu.cbu_bridgeaddr[1] = cu->cu_rootid >> 32;
+	bpdu.cbu_bridgeaddr[2] = cu->cu_rootid >> 24;
+	bpdu.cbu_bridgeaddr[3] = cu->cu_rootid >> 16;
+	bpdu.cbu_bridgeaddr[4] = cu->cu_rootid >> 8;
+	bpdu.cbu_bridgeaddr[5] = cu->cu_rootid >> 0;
+
+	bpdu.cbu_portid = htons(cu->cu_port_id);
+	bpdu.cbu_messageage = htons(cu->cu_message_age);
+	bpdu.cbu_maxage = htons(cu->cu_max_age);
+	bpdu.cbu_hellotime = htons(cu->cu_hello_time);
+	bpdu.cbu_forwarddelay = htons(cu->cu_forward_delay);
+
+	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
+	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
+	eh->ether_type = htons(sizeof(bpdu));
+
+	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
+
+	/* XXX: safe here?!? */
+	BRIDGE_UNLOCK(sc);
+	bridge_enqueue(sc, ifp, m, 0);
+	BRIDGE_LOCK(sc);
+}
+
+int
+bstp_root_bridge(struct bridge_softc *sc)
+{
+	return (sc->sc_designated_root == sc->sc_bridge_id);
+}
+
+int
+bstp_supersedes_port_info(struct bridge_softc *sc, struct bridge_iflist *bif,
+    struct bstp_config_unit *cu)
+{
+	if (cu->cu_rootid < bif->bif_designated_root)
+		return (1);
+	if (cu->cu_rootid > bif->bif_designated_root)
+		return (0);
+
+	if (cu->cu_root_path_cost < bif->bif_designated_cost)
+		return (1);
+	if (cu->cu_root_path_cost > bif->bif_designated_cost)
+		return (0);
+
+	if (cu->cu_bridge_id < bif->bif_designated_bridge)
+		return (1);
+	if (cu->cu_bridge_id > bif->bif_designated_bridge)
+		return (0);
+
+	if (sc->sc_bridge_id != cu->cu_bridge_id)
+		return (1);
+	if (cu->cu_port_id <= bif->bif_designated_port)
+		return (1);
+	return (0);
+}
+
+void
+bstp_record_config_information(struct bridge_softc *sc,
+    struct bridge_iflist *bif, struct bstp_config_unit *cu)
+{
+	bif->bif_designated_root = cu->cu_rootid;
+	bif->bif_designated_cost = cu->cu_root_path_cost;
+	bif->bif_designated_bridge = cu->cu_bridge_id;
+	bif->bif_designated_port = cu->cu_port_id;
+	bstp_timer_start(&bif->bif_message_age_timer, cu->cu_message_age);
+}
+
+void
+bstp_record_config_timeout_values(struct bridge_softc *sc,
+    struct bstp_config_unit *config)
+{
+	sc->sc_max_age = config->cu_max_age;
+	sc->sc_hello_time = config->cu_hello_time;
+	sc->sc_forward_delay = config->cu_forward_delay;
+	sc->sc_topology_change = config->cu_topology_change;
+}
+
+void
+bstp_config_bpdu_generation(struct bridge_softc *sc)
+{
+	struct bridge_iflist *bif;
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bstp_designated_port(sc, bif) &&
+		    (bif->bif_state != BSTP_IFSTATE_DISABLED))
+			bstp_transmit_config(sc, bif);
+	}
+}
+
+int
+bstp_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	return ((bif->bif_designated_bridge == sc->sc_bridge_id)
+	    && (bif->bif_designated_port == bif->bif_port_id));
+}
+
+void
+bstp_transmit_tcn(struct bridge_softc *sc)
+{
+	struct bstp_tbpdu bpdu;
+	struct bridge_iflist *bif = sc->sc_root_port;
+	struct ifnet *ifp = bif->bif_ifp;
+	struct ether_header *eh;
+	struct mbuf *m;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	if ((ifp->if_flags & IFF_RUNNING) == 0)
+		return;
+
+	MGETHDR(m, M_DONTWAIT, MT_DATA);
+	if (m == NULL)
+		return;
+
+	m->m_pkthdr.rcvif = ifp;
+	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
+	m->m_len = m->m_pkthdr.len;
+
+	eh = mtod(m, struct ether_header *);
+
+	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
+	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
+	eh->ether_type = htons(sizeof(bpdu));
+
+	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
+	bpdu.tbu_ctl = LLC_UI;
+	bpdu.tbu_protoid = 0;
+	bpdu.tbu_protover = 0;
+	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
+
+	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
+
+	/* XXX: safe here?!? */
+	BRIDGE_UNLOCK(sc);
+	bridge_enqueue(sc, ifp, m, 0);
+	BRIDGE_LOCK(sc);
+}
+
+void
+bstp_configuration_update(struct bridge_softc *sc)
+{
+	BRIDGE_LOCK_ASSERT(sc);
+
+	bstp_root_selection(sc);
+	bstp_designated_port_selection(sc);
+}
+
+void
+bstp_root_selection(struct bridge_softc *sc)
+{
+	struct bridge_iflist *root_port = NULL, *bif;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bstp_designated_port(sc, bif))
+			continue;
+		if (bif->bif_state == BSTP_IFSTATE_DISABLED)
+			continue;
+		if (bif->bif_designated_root >= sc->sc_bridge_id)
+			continue;
+		if (root_port == NULL)
+			goto set_port;
+
+		if (bif->bif_designated_root < root_port->bif_designated_root)
+			goto set_port;
+		if (bif->bif_designated_root > root_port->bif_designated_root)
+			continue;
+
+		if ((bif->bif_designated_cost + bif->bif_path_cost) <
+		    (root_port->bif_designated_cost + root_port->bif_path_cost))
+			goto set_port;
+		if ((bif->bif_designated_cost + bif->bif_path_cost) >
+		    (root_port->bif_designated_cost + root_port->bif_path_cost))
+			continue;
+
+		if (bif->bif_designated_bridge <
+		    root_port->bif_designated_bridge)
+			goto set_port;
+		if (bif->bif_designated_bridge >
+		    root_port->bif_designated_bridge)
+			continue;
+
+		if (bif->bif_designated_port < root_port->bif_designated_port)
+			goto set_port;
+		if (bif->bif_designated_port > root_port->bif_designated_port)
+			continue;
+
+		if (bif->bif_port_id >= root_port->bif_port_id)
+			continue;
+set_port:
+		root_port = bif;
+	}
+
+	sc->sc_root_port = root_port;
+	if (root_port == NULL) {
+		sc->sc_designated_root = sc->sc_bridge_id;
+		sc->sc_root_path_cost = 0;
+	} else {
+		sc->sc_designated_root = root_port->bif_designated_root;
+		sc->sc_root_path_cost = root_port->bif_designated_cost +
+		    root_port->bif_path_cost;
+	}
+}
+
+void
+bstp_designated_port_selection(struct bridge_softc *sc)
+{
+	struct bridge_iflist *bif;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bstp_designated_port(sc, bif))
+			goto designated;
+		if (bif->bif_designated_root != sc->sc_designated_root)
+			goto designated;
+
+		if (sc->sc_root_path_cost < bif->bif_designated_cost)
+			goto designated;
+		if (sc->sc_root_path_cost > bif->bif_designated_cost)
+			continue;
+
+		if (sc->sc_bridge_id < bif->bif_designated_bridge)
+			goto designated;
+		if (sc->sc_bridge_id > bif->bif_designated_bridge)
+			continue;
+
+		if (bif->bif_port_id > bif->bif_designated_port)
+			continue;
+designated:
+		bstp_become_designated_port(sc, bif);
+	}
+}
+
+void
+bstp_become_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	bif->bif_designated_root = sc->sc_designated_root;
+	bif->bif_designated_cost = sc->sc_root_path_cost;
+	bif->bif_designated_bridge = sc->sc_bridge_id;
+	bif->bif_designated_port = bif->bif_port_id;
+}
+
+void
+bstp_port_state_selection(struct bridge_softc *sc)
+{
+	struct bridge_iflist *bif;
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bif == sc->sc_root_port) {
+			bif->bif_config_pending = 0;
+			bif->bif_topology_change_acknowledge = 0;
+			bstp_make_forwarding(sc, bif);
+		} else if (bstp_designated_port(sc, bif)) {
+			bstp_timer_stop(&bif->bif_message_age_timer);
+			bstp_make_forwarding(sc, bif);
+		} else {
+			bif->bif_config_pending = 0;
+			bif->bif_topology_change_acknowledge = 0;
+			bstp_make_blocking(sc, bif);
+		}
+	}
+}
+
+void
+bstp_make_forwarding(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	if (bif->bif_state == BSTP_IFSTATE_BLOCKING) {
+		bstp_set_port_state(bif, BSTP_IFSTATE_LISTENING);
+		bstp_timer_start(&bif->bif_forward_delay_timer, 0);
+	}
+}
+
+void
+bstp_make_blocking(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	BRIDGE_LOCK_ASSERT(sc);
+
+	if ((bif->bif_state != BSTP_IFSTATE_DISABLED) &&
+	    (bif->bif_state != BSTP_IFSTATE_BLOCKING)) {
+		if ((bif->bif_state == BSTP_IFSTATE_FORWARDING) ||
+		    (bif->bif_state == BSTP_IFSTATE_LEARNING)) {
+			if (bif->bif_change_detection_enabled) {
+				bstp_topology_change_detection(sc);
+			}
+		}
+		bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
+		bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
+		bstp_timer_stop(&bif->bif_forward_delay_timer);
+	}
+}
+
+void
+bstp_set_port_state(struct bridge_iflist *bif, uint8_t state)
+{
+	bif->bif_state = state;
+}
+
+void
+bstp_topology_change_detection(struct bridge_softc *sc)
+{
+	if (bstp_root_bridge(sc)) {
+		sc->sc_topology_change = 1;
+		bstp_timer_start(&sc->sc_topology_change_timer, 0);
+	} else if (!sc->sc_topology_change_detected) {
+		bstp_transmit_tcn(sc);
+		bstp_timer_start(&sc->sc_tcn_timer, 0);
+	}
+	sc->sc_topology_change_detected = 1;
+}
+
+void
+bstp_topology_change_acknowledged(struct bridge_softc *sc)
+{
+	sc->sc_topology_change_detected = 0;
+	bstp_timer_stop(&sc->sc_tcn_timer);
+}
+
+void
+bstp_acknowledge_topology_change(struct bridge_softc *sc,
+    struct bridge_iflist *bif)
+{
+	bif->bif_topology_change_acknowledge = 1;
+	bstp_transmit_config(sc, bif);
+}
+
+struct mbuf *
+bstp_input(struct ifnet *ifp, struct mbuf *m)
+{
+	struct bridge_softc *sc = ifp->if_bridge;
+	struct bridge_iflist *bif = NULL;
+	struct ether_header *eh;
+	struct bstp_tbpdu tpdu;
+	struct bstp_cbpdu cpdu;
+	struct bstp_config_unit cu;
+	struct bstp_tcn_unit tu;
+	uint16_t len;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	eh = mtod(m, struct ether_header *);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bif->bif_ifp == ifp)
+			break;
+	}
+	if (bif == NULL)
+		goto out;
+
+	len = ntohs(eh->ether_type);
+	if (len < sizeof(tpdu))
+		goto out;
+
+	m_adj(m, ETHER_HDR_LEN);
+
+	if (m->m_pkthdr.len > len)
+		m_adj(m, len - m->m_pkthdr.len);
+	if (m->m_len < sizeof(tpdu) &&
+	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
+		goto out;
+
+	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
+
+	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
+	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
+	    tpdu.tbu_ctl != LLC_UI)
+		goto out;
+	if (tpdu.tbu_protoid != 0 || tpdu.tbu_protover != 0)
+		goto out;
+
+	switch (tpdu.tbu_bpdutype) {
+	case BSTP_MSGTYPE_TCN:
+		tu.tu_message_type = tpdu.tbu_bpdutype;
+		bstp_received_tcn_bpdu(sc, bif, &tu);
+		break;
+	case BSTP_MSGTYPE_CFG:
+		if (m->m_len < sizeof(cpdu) &&
+		    (m = m_pullup(m, sizeof(cpdu))) == NULL)
+			goto out;
+		memcpy(&cpdu, mtod(m, caddr_t), sizeof(cpdu));
+
+		cu.cu_rootid =
+		    (((uint64_t)ntohs(cpdu.cbu_rootpri)) << 48) |
+		    (((uint64_t)cpdu.cbu_rootaddr[0]) << 40) |
+		    (((uint64_t)cpdu.cbu_rootaddr[1]) << 32) |
+		    (((uint64_t)cpdu.cbu_rootaddr[2]) << 24) |
+		    (((uint64_t)cpdu.cbu_rootaddr[3]) << 16) |
+		    (((uint64_t)cpdu.cbu_rootaddr[4]) << 8) |
+		    (((uint64_t)cpdu.cbu_rootaddr[5]) << 0);
+
+		cu.cu_bridge_id =
+		    (((uint64_t)ntohs(cpdu.cbu_bridgepri)) << 48) |
+		    (((uint64_t)cpdu.cbu_bridgeaddr[0]) << 40) |
+		    (((uint64_t)cpdu.cbu_bridgeaddr[1]) << 32) |
+		    (((uint64_t)cpdu.cbu_bridgeaddr[2]) << 24) |
+		    (((uint64_t)cpdu.cbu_bridgeaddr[3]) << 16) |
+		    (((uint64_t)cpdu.cbu_bridgeaddr[4]) << 8) |
+		    (((uint64_t)cpdu.cbu_bridgeaddr[5]) << 0);
+
+		cu.cu_root_path_cost = ntohl(cpdu.cbu_rootpathcost);
+		cu.cu_message_age = ntohs(cpdu.cbu_messageage);
+		cu.cu_max_age = ntohs(cpdu.cbu_maxage);
+		cu.cu_hello_time = ntohs(cpdu.cbu_hellotime);
+		cu.cu_forward_delay = ntohs(cpdu.cbu_forwarddelay);
+		cu.cu_port_id = ntohs(cpdu.cbu_portid);
+		cu.cu_message_type = cpdu.cbu_bpdutype;
+		cu.cu_topology_change_acknowledgment =
+		    (cpdu.cbu_flags & BSTP_FLAG_TCA) ? 1 : 0;
+		cu.cu_topology_change =
+		    (cpdu.cbu_flags & BSTP_FLAG_TC) ? 1 : 0;
+		bstp_received_config_bpdu(sc, bif, &cu);
+		break;
+	default:
+		goto out;
+	}
+
+ out:
+	if (m)
+		m_freem(m);
+	return (NULL);
+}
+
+void
+bstp_received_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
+    struct bstp_config_unit *cu)
+{
+	int root;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	root = bstp_root_bridge(sc);
+
+	if (bif->bif_state != BSTP_IFSTATE_DISABLED) {
+		if (bstp_supersedes_port_info(sc, bif, cu)) {
+			bstp_record_config_information(sc, bif, cu);
+			bstp_configuration_update(sc);
+			bstp_port_state_selection(sc);
+
+			if ((bstp_root_bridge(sc) == 0) && root) {
+				bstp_timer_stop(&sc->sc_hello_timer);
+
+				if (sc->sc_topology_change_detected) {
+					bstp_timer_stop(
+					    &sc->sc_topology_change_timer);
+					bstp_transmit_tcn(sc);
+					bstp_timer_start(&sc->sc_tcn_timer, 0);
+				}
+			}
+
+			if (bif == sc->sc_root_port) {
+				bstp_record_config_timeout_values(sc, cu);
+				bstp_config_bpdu_generation(sc);
+
+				if (cu->cu_topology_change_acknowledgment)
+					bstp_topology_change_acknowledged(sc);
+			}
+		} else if (bstp_designated_port(sc, bif))
+			bstp_transmit_config(sc, bif);
+	}
+}
+
+void
+bstp_received_tcn_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
+    struct bstp_tcn_unit *tcn)
+{
+	if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
+	    bstp_designated_port(sc, bif)) {
+		bstp_topology_change_detection(sc);
+		bstp_acknowledge_topology_change(sc, bif);
+	}
+}
+
+void
+bstp_hello_timer_expiry(struct bridge_softc *sc)
+{
+	bstp_config_bpdu_generation(sc);
+	bstp_timer_start(&sc->sc_hello_timer, 0);
+}
+
+void
+bstp_message_age_timer_expiry(struct bridge_softc *sc,
+    struct bridge_iflist *bif)
+{
+	int root;
+
+	root = bstp_root_bridge(sc);
+	bstp_become_designated_port(sc, bif);
+	bstp_configuration_update(sc);
+	bstp_port_state_selection(sc);
+
+	if ((bstp_root_bridge(sc)) && (root == 0)) {
+		sc->sc_max_age = sc->sc_bridge_max_age;
+		sc->sc_hello_time = sc->sc_bridge_hello_time;
+		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
+
+		bstp_topology_change_detection(sc);
+		bstp_timer_stop(&sc->sc_tcn_timer);
+		bstp_config_bpdu_generation(sc);
+		bstp_timer_start(&sc->sc_hello_timer, 0);
+	}
+}
+
+void
+bstp_forward_delay_timer_expiry(struct bridge_softc *sc,
+    struct bridge_iflist *bif)
+{
+	if (bif->bif_state == BSTP_IFSTATE_LISTENING) {
+		bstp_set_port_state(bif, BSTP_IFSTATE_LEARNING);
+		bstp_timer_start(&bif->bif_forward_delay_timer, 0);
+	} else if (bif->bif_state == BSTP_IFSTATE_LEARNING) {
+		bstp_set_port_state(bif, BSTP_IFSTATE_FORWARDING);
+		if (bstp_designated_for_some_port(sc) &&
+		    bif->bif_change_detection_enabled)
+			bstp_topology_change_detection(sc);
+	}
+}
+
+int
+bstp_designated_for_some_port(struct bridge_softc *sc)
+{
+
+	struct bridge_iflist *bif;
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bif->bif_designated_bridge == sc->sc_bridge_id)
+			return (1);
+	}
+	return (0);
+}
+
+void
+bstp_tcn_timer_expiry(struct bridge_softc *sc)
+{
+	bstp_transmit_tcn(sc);
+	bstp_timer_start(&sc->sc_tcn_timer, 0);
+}
+
+void
+bstp_topology_change_timer_expiry(struct bridge_softc *sc)
+{
+	sc->sc_topology_change_detected = 0;
+	sc->sc_topology_change = 0;
+}
+
+void
+bstp_hold_timer_expiry(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	if (bif->bif_config_pending)
+		bstp_transmit_config(sc, bif);
+}
+
+void
+bstp_initialization(struct bridge_softc *sc)
+{
+	struct bridge_iflist *bif, *mif;
+
+	mif = NULL;
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bif->bif_ifp->if_type != IFT_ETHER)
+			continue;
+		bif->bif_port_id = (bif->bif_priority << 8) |
+		    (bif->bif_ifp->if_index & 0xff);
+
+		if (mif == NULL) {
+			mif = bif;
+			continue;
+		}
+		if (memcmp(IF_LLADDR(bif->bif_ifp),
+		    IF_LLADDR(mif->bif_ifp), ETHER_ADDR_LEN) < 0) {
+			mif = bif;
+			continue;
+		}
+	}
+	if (mif == NULL) {
+		bstp_stop(sc);
+		return;
+	}
+
+	sc->sc_bridge_id =
+	    (((uint64_t)sc->sc_bridge_priority) << 48) |
+	    (((uint64_t)IF_LLADDR(mif->bif_ifp)[0]) << 40) |
+	    (((uint64_t)IF_LLADDR(mif->bif_ifp)[1]) << 32) |
+	    (IF_LLADDR(mif->bif_ifp)[2] << 24) |
+	    (IF_LLADDR(mif->bif_ifp)[3] << 16) |
+	    (IF_LLADDR(mif->bif_ifp)[4] << 8) |
+	    (IF_LLADDR(mif->bif_ifp)[5]);
+
+	sc->sc_designated_root = sc->sc_bridge_id;
+	sc->sc_root_path_cost = 0;
+	sc->sc_root_port = NULL;
+
+	sc->sc_max_age = sc->sc_bridge_max_age;
+	sc->sc_hello_time = sc->sc_bridge_hello_time;
+	sc->sc_forward_delay = sc->sc_bridge_forward_delay;
+	sc->sc_topology_change_detected = 0;
+	sc->sc_topology_change = 0;
+	bstp_timer_stop(&sc->sc_tcn_timer);
+	bstp_timer_stop(&sc->sc_topology_change_timer);
+
+	if (callout_pending(&sc->sc_bstpcallout) == 0)
+		callout_reset(&sc->sc_bstpcallout, hz,
+		    bstp_tick, sc);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if (bif->bif_flags & IFBIF_STP)
+			bstp_enable_port(sc, bif);
+		else
+			bstp_disable_port(sc, bif);
+	}
+
+	bstp_port_state_selection(sc);
+	bstp_config_bpdu_generation(sc);
+	bstp_timer_start(&sc->sc_hello_timer, 0);
+}
+
+void
+bstp_stop(struct bridge_softc *sc)
+{
+	struct bridge_iflist *bif;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
+		bstp_timer_stop(&bif->bif_hold_timer);
+		bstp_timer_stop(&bif->bif_message_age_timer);
+		bstp_timer_stop(&bif->bif_forward_delay_timer);
+	}
+
+	callout_stop(&sc->sc_bstpcallout);
+
+	bstp_timer_stop(&sc->sc_topology_change_timer);
+	bstp_timer_stop(&sc->sc_tcn_timer);
+	bstp_timer_stop(&sc->sc_hello_timer);
+
+}
+
+void
+bstp_initialize_port(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	bstp_become_designated_port(sc, bif);
+	bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
+	bif->bif_topology_change_acknowledge = 0;
+	bif->bif_config_pending = 0;
+	bif->bif_change_detection_enabled = 1;
+	bstp_timer_stop(&bif->bif_message_age_timer);
+	bstp_timer_stop(&bif->bif_forward_delay_timer);
+	bstp_timer_stop(&bif->bif_hold_timer);
+}
+
+void
+bstp_enable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	bstp_initialize_port(sc, bif);
+	bstp_port_state_selection(sc);
+}
+
+void
+bstp_disable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	int root;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	root = bstp_root_bridge(sc);
+	bstp_become_designated_port(sc, bif);
+	bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
+	bif->bif_topology_change_acknowledge = 0;
+	bif->bif_config_pending = 0;
+	bstp_timer_stop(&bif->bif_message_age_timer);
+	bstp_timer_stop(&bif->bif_forward_delay_timer);
+	bstp_configuration_update(sc);
+	bstp_port_state_selection(sc);
+	bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
+
+	if (bstp_root_bridge(sc) && (root == 0)) {
+		sc->sc_max_age = sc->sc_bridge_max_age;
+		sc->sc_hello_time = sc->sc_bridge_hello_time;
+		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
+
+		bstp_topology_change_detection(sc);
+		bstp_timer_stop(&sc->sc_tcn_timer);
+		bstp_config_bpdu_generation(sc);
+		bstp_timer_start(&sc->sc_hello_timer, 0);
+	}
+}
+
+void
+bstp_set_bridge_priority(struct bridge_softc *sc, uint64_t new_bridge_id)
+{
+	struct bridge_iflist *bif;
+	int root;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	root = bstp_root_bridge(sc);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bstp_designated_port(sc, bif))
+			bif->bif_designated_bridge = new_bridge_id;
+	}
+
+	sc->sc_bridge_id = new_bridge_id;
+
+	bstp_configuration_update(sc);
+	bstp_port_state_selection(sc);
+
+	if (bstp_root_bridge(sc) && (root == 0)) {
+		sc->sc_max_age = sc->sc_bridge_max_age;
+		sc->sc_hello_time = sc->sc_bridge_hello_time;
+		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
+
+		bstp_topology_change_detection(sc);
+		bstp_timer_stop(&sc->sc_tcn_timer);
+		bstp_config_bpdu_generation(sc);
+		bstp_timer_start(&sc->sc_hello_timer, 0);
+	}
+}
+
+void
+bstp_set_port_priority(struct bridge_softc *sc, struct bridge_iflist *bif,
+    uint16_t new_port_id)
+{
+	if (bstp_designated_port(sc, bif))
+		bif->bif_designated_port = new_port_id;
+
+	bif->bif_port_id = new_port_id;
+
+	if ((sc->sc_bridge_id == bif->bif_designated_bridge) &&
+	    (bif->bif_port_id < bif->bif_designated_port)) {
+		bstp_become_designated_port(sc, bif);
+		bstp_port_state_selection(sc);
+	}
+}
+
+void
+bstp_set_path_cost(struct bridge_softc *sc, struct bridge_iflist *bif,
+    uint32_t path_cost)
+{
+	bif->bif_path_cost = path_cost;
+	bstp_configuration_update(sc);
+	bstp_port_state_selection(sc);
+}
+
+void
+bstp_enable_change_detection(struct bridge_iflist *bif)
+{
+	bif->bif_change_detection_enabled = 1;
+}
+
+void
+bstp_disable_change_detection(struct bridge_iflist *bif)
+{
+	bif->bif_change_detection_enabled = 0;
+}
+
+void
+bstp_linkstate(struct ifnet *ifp, int state)
+{
+	struct bridge_softc *sc;
+	struct bridge_iflist *bif;
+
+	sc = ifp->if_bridge;
+	BRIDGE_LOCK(sc);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+
+		if (bif->bif_ifp == ifp) {
+			bstp_ifupdstatus(sc, bif);
+			break;
+		}
+	}
+
+	BRIDGE_UNLOCK(sc);
+}
+
+void
+bstp_ifupdstatus(struct bridge_softc *sc, struct bridge_iflist *bif)
+{
+	struct ifnet *ifp = bif->bif_ifp;
+	struct ifmediareq ifmr;
+	int error = 0;
+
+	BRIDGE_LOCK_ASSERT(sc);
+
+	bzero((char *)&ifmr, sizeof(ifmr));
+	error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);
+
+	if ((error == 0) && (ifp->if_flags & IFF_UP)) {
+	 	if (ifmr.ifm_status & IFM_ACTIVE) {
+			if (bif->bif_state == BSTP_IFSTATE_DISABLED)
+				bstp_enable_port(sc, bif);
+
+		} else {
+			if (bif->bif_state != BSTP_IFSTATE_DISABLED)
+				bstp_disable_port(sc, bif);
+		}
+		return;
+	}
+
+	if (bif->bif_state != BSTP_IFSTATE_DISABLED)
+		bstp_disable_port(sc, bif);
+}
+
+void
+bstp_tick(void *arg)
+{
+	struct bridge_softc *sc = arg;
+	struct bridge_iflist *bif;
+
+	BRIDGE_LOCK(sc);
+
+#if 0
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		/*
+		 * XXX This can cause a lag in "link does away"
+		 * XXX and "spanning tree gets updated".  We need
+		 * XXX come sort of callback from the link state
+		 * XXX update code to kick spanning tree.
+		 * XXX --thorpej@NetBSD.org
+		 */
+		bstp_ifupdstatus(sc, bif);
+	}
+#endif
+
+	if (bstp_timer_expired(&sc->sc_hello_timer, sc->sc_hello_time))
+		bstp_hello_timer_expiry(sc);
+
+	if (bstp_timer_expired(&sc->sc_tcn_timer, sc->sc_bridge_hello_time))
+		bstp_tcn_timer_expiry(sc);
+
+	if (bstp_timer_expired(&sc->sc_topology_change_timer,
+	    sc->sc_topology_change_time))
+		bstp_topology_change_timer_expiry(sc);
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bstp_timer_expired(&bif->bif_message_age_timer,
+		    sc->sc_max_age))
+			bstp_message_age_timer_expiry(sc, bif);
+	}
+
+	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
+		if ((bif->bif_flags & IFBIF_STP) == 0)
+			continue;
+		if (bstp_timer_expired(&bif->bif_forward_delay_timer,
+		    sc->sc_forward_delay))
+			bstp_forward_delay_timer_expiry(sc, bif);
+
+		if (bstp_timer_expired(&bif->bif_hold_timer,
+		    sc->sc_hold_time))
+			bstp_hold_timer_expiry(sc, bif);
+	}
+
+	if (sc->sc_if.if_flags & IFF_RUNNING)
+		callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
+
+	BRIDGE_UNLOCK(sc);
+}
+
+void
+bstp_timer_start(struct bridge_timer *t, uint16_t v)
+{
+	t->value = v;
+	t->active = 1;
+}
+
+void
+bstp_timer_stop(struct bridge_timer *t)
+{
+	t->value = 0;
+	t->active = 0;
+}
+
+int
+bstp_timer_expired(struct bridge_timer *t, uint16_t v)
+{
+	if (t->active == 0)
+		return (0);
+	t->value += BSTP_TICK_VAL;
+	if (t->value >= v) {
+		bstp_timer_stop(t);
+		return (1);
+	}
+	return (0);
+
+}