/*      $NetBSD: bridgestp.c,v 1.5 2003/11/28 08:56:48 keihan Exp $     */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2000 Jason L. Wright (jason@thought.net)
 * Copyright (c) 2006 Andrew Thompson (thompsa@FreeBSD.org)
 * 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.
 *
 * 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 802.1D-2004, June 9, 2004.
 */

#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/malloc.h>
#include <sys/callout.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/taskqueue.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_llc.h>
#include <net/if_media.h>
#include <net/if_bridgevar.h>
#include <net/vnet.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#include <net/bridgestp.h>

#ifdef  BRIDGESTP_DEBUG
#define DPRINTF(fmt, arg...)    printf("bstp: " fmt, ##arg)
#else
#define DPRINTF(fmt, arg...)    (void)0
#endif

#define PV2ADDR(pv, eaddr)      do {            \
        eaddr[0] = pv >> 40;                    \
        eaddr[1] = pv >> 32;                    \
        eaddr[2] = pv >> 24;                    \
        eaddr[3] = pv >> 16;                    \
        eaddr[4] = pv >> 8;                     \
        eaddr[5] = pv >> 0;                     \
} while (0)

#define INFO_BETTER     1
#define INFO_SAME       0
#define INFO_WORSE      -1

const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };

LIST_HEAD(, bstp_state) bstp_list = LIST_HEAD_INITIALIZER(bstp_list);
static struct mtx       bstp_list_mtx;

static void     bstp_transmit(struct bstp_state *, struct bstp_port *);
static void     bstp_transmit_bpdu(struct bstp_state *, struct bstp_port *);
static void     bstp_transmit_tcn(struct bstp_state *, struct bstp_port *);
static void     bstp_decode_bpdu(struct bstp_port *, struct bstp_cbpdu *,
                    struct bstp_config_unit *);
static void     bstp_send_bpdu(struct bstp_state *, struct bstp_port *,
                    struct bstp_cbpdu *);
static int      bstp_pdu_flags(struct bstp_port *);
static void     bstp_received_stp(struct bstp_state *, struct bstp_port *,
                    struct mbuf **, struct bstp_tbpdu *);
static void     bstp_received_rstp(struct bstp_state *, struct bstp_port *,
                    struct mbuf **, struct bstp_tbpdu *);
static void     bstp_received_tcn(struct bstp_state *, struct bstp_port *,
                    struct bstp_tcn_unit *);
static void     bstp_received_bpdu(struct bstp_state *, struct bstp_port *,
                    struct bstp_config_unit *);
static int      bstp_pdu_rcvtype(struct bstp_port *, struct bstp_config_unit *);
static int      bstp_pdu_bettersame(struct bstp_port *, int);
static int      bstp_info_cmp(struct bstp_pri_vector *,
                    struct bstp_pri_vector *);
static int      bstp_info_superior(struct bstp_pri_vector *,
                    struct bstp_pri_vector *);
static void     bstp_assign_roles(struct bstp_state *);
static void     bstp_update_roles(struct bstp_state *, struct bstp_port *);
static void     bstp_update_state(struct bstp_state *, struct bstp_port *);
static void     bstp_update_tc(struct bstp_port *);
static void     bstp_update_info(struct bstp_port *);
static void     bstp_set_other_tcprop(struct bstp_port *);
static void     bstp_set_all_reroot(struct bstp_state *);
static void     bstp_set_all_sync(struct bstp_state *);
static void     bstp_set_port_state(struct bstp_port *, int);
static void     bstp_set_port_role(struct bstp_port *, int);
static void     bstp_set_port_proto(struct bstp_port *, int);
static void     bstp_set_port_tc(struct bstp_port *, int);
static void     bstp_set_timer_tc(struct bstp_port *);
static void     bstp_set_timer_msgage(struct bstp_port *);
static int      bstp_rerooted(struct bstp_state *, struct bstp_port *);
static uint32_t bstp_calc_path_cost(struct bstp_port *);
static void     bstp_notify_state(void *, int);
static void     bstp_notify_rtage(void *, int);
static void     bstp_ifupdstatus(void *, int);
static void     bstp_enable_port(struct bstp_state *, struct bstp_port *);
static void     bstp_disable_port(struct bstp_state *, struct bstp_port *);
static void     bstp_tick(void *);
static void     bstp_timer_start(struct bstp_timer *, uint16_t);
static void     bstp_timer_stop(struct bstp_timer *);
static void     bstp_timer_latch(struct bstp_timer *);
static int      bstp_timer_dectest(struct bstp_timer *);
static void     bstp_hello_timer_expiry(struct bstp_state *,
                    struct bstp_port *);
static void     bstp_message_age_expiry(struct bstp_state *,
                    struct bstp_port *);
static void     bstp_migrate_delay_expiry(struct bstp_state *,
                    struct bstp_port *);
static void     bstp_edge_delay_expiry(struct bstp_state *,
                    struct bstp_port *);
static int      bstp_addr_cmp(const uint8_t *, const uint8_t *);
static int      bstp_same_bridgeid(uint64_t, uint64_t);
static void     bstp_reinit(struct bstp_state *);

static void
bstp_transmit(struct bstp_state *bs, struct bstp_port *bp)
{
        NET_EPOCH_ASSERT();

        if (bs->bs_running == 0)
                return;

        /*
         * a PDU can only be sent if we have tx quota left and the
         * hello timer is running.
         */
        if (bp->bp_hello_timer.active == 0) {
                /* Test if it needs to be reset */
                bstp_hello_timer_expiry(bs, bp);
                return;
        }
        if (bp->bp_txcount > bs->bs_txholdcount)
                /* Ran out of karma */
                return;

        if (bp->bp_protover == BSTP_PROTO_RSTP) {
                bstp_transmit_bpdu(bs, bp);
                bp->bp_tc_ack = 0;
        } else { /* STP */
                switch (bp->bp_role) {
                        case BSTP_ROLE_DESIGNATED:
                                bstp_transmit_bpdu(bs, bp);
                                bp->bp_tc_ack = 0;
                                break;

                        case BSTP_ROLE_ROOT:
                                bstp_transmit_tcn(bs, bp);
                                break;
                }
        }
        bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
        bp->bp_flags &= ~BSTP_PORT_NEWINFO;
}

static void
bstp_transmit_bpdu(struct bstp_state *bs, struct bstp_port *bp)
{
        struct bstp_cbpdu bpdu;

        BSTP_LOCK_ASSERT(bs);

        bpdu.cbu_rootpri = htons(bp->bp_desg_pv.pv_root_id >> 48);
        PV2ADDR(bp->bp_desg_pv.pv_root_id, bpdu.cbu_rootaddr);

        bpdu.cbu_rootpathcost = htonl(bp->bp_desg_pv.pv_cost);

        bpdu.cbu_bridgepri = htons(bp->bp_desg_pv.pv_dbridge_id >> 48);
        PV2ADDR(bp->bp_desg_pv.pv_dbridge_id, bpdu.cbu_bridgeaddr);

        bpdu.cbu_portid = htons(bp->bp_port_id);
        bpdu.cbu_messageage = htons(bp->bp_desg_msg_age);
        bpdu.cbu_maxage = htons(bp->bp_desg_max_age);
        bpdu.cbu_hellotime = htons(bp->bp_desg_htime);
        bpdu.cbu_forwarddelay = htons(bp->bp_desg_fdelay);

        bpdu.cbu_flags = bstp_pdu_flags(bp);

        switch (bp->bp_protover) {
                case BSTP_PROTO_STP:
                        bpdu.cbu_bpdutype = BSTP_MSGTYPE_CFG;
                        break;

                case BSTP_PROTO_RSTP:
                        bpdu.cbu_bpdutype = BSTP_MSGTYPE_RSTP;
                        break;
        }

        bstp_send_bpdu(bs, bp, &bpdu);
}

static void
bstp_transmit_tcn(struct bstp_state *bs, struct bstp_port *bp)
{
        struct bstp_tbpdu bpdu;
        struct ifnet *ifp = bp->bp_ifp;
        struct ether_header *eh;
        struct mbuf *m;

        KASSERT(bp == bs->bs_root_port, ("%s: bad root port\n", __func__));

        if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
                return;

        m = m_gethdr(M_NOWAIT, 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));

        bp->bp_txcount++;
        ifp->if_transmit(ifp, m);
}

static void
bstp_decode_bpdu(struct bstp_port *bp, struct bstp_cbpdu *cpdu,
    struct bstp_config_unit *cu)
{
        int flags;

        cu->cu_pv.pv_root_id =
            (((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_pv.pv_dbridge_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_pv.pv_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_pv.pv_dport_id = ntohs(cpdu->cbu_portid);
        cu->cu_pv.pv_port_id = bp->bp_port_id;
        cu->cu_message_type = cpdu->cbu_bpdutype;

        /* Strip off unused flags in STP mode */
        flags = cpdu->cbu_flags;
        switch (cpdu->cbu_protover) {
                case BSTP_PROTO_STP:
                        flags &= BSTP_PDU_STPMASK;
                        /* A STP BPDU explicitly conveys a Designated Port */
                        cu->cu_role = BSTP_ROLE_DESIGNATED;
                        break;

                case BSTP_PROTO_RSTP:
                        flags &= BSTP_PDU_RSTPMASK;
                        break;
        }

        cu->cu_topology_change_ack =
                (flags & BSTP_PDU_F_TCA) ? 1 : 0;
        cu->cu_proposal =
                (flags & BSTP_PDU_F_P) ? 1 : 0;
        cu->cu_agree =
                (flags & BSTP_PDU_F_A) ? 1 : 0;
        cu->cu_learning =
                (flags & BSTP_PDU_F_L) ? 1 : 0;
        cu->cu_forwarding =
                (flags & BSTP_PDU_F_F) ? 1 : 0;
        cu->cu_topology_change =
                (flags & BSTP_PDU_F_TC) ? 1 : 0;

        switch ((flags & BSTP_PDU_PRMASK) >> BSTP_PDU_PRSHIFT) {
                case BSTP_PDU_F_ROOT:
                        cu->cu_role = BSTP_ROLE_ROOT;
                        break;
                case BSTP_PDU_F_ALT:
                        cu->cu_role = BSTP_ROLE_ALTERNATE;
                        break;
                case BSTP_PDU_F_DESG:
                        cu->cu_role = BSTP_ROLE_DESIGNATED;
                        break;
        }
}

static void
bstp_send_bpdu(struct bstp_state *bs, struct bstp_port *bp,
    struct bstp_cbpdu *bpdu)
{
        struct ifnet *ifp;
        struct mbuf *m;
        struct ether_header *eh;

        BSTP_LOCK_ASSERT(bs);
        NET_EPOCH_ASSERT();

        ifp = bp->bp_ifp;

        if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
                return;

        m = m_gethdr(M_NOWAIT, MT_DATA);
        if (m == NULL)
                return;

        eh = mtod(m, struct ether_header *);

        bpdu->cbu_ssap = bpdu->cbu_dsap = LLC_8021D_LSAP;
        bpdu->cbu_ctl = LLC_UI;
        bpdu->cbu_protoid = htons(BSTP_PROTO_ID);

        memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
        memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);

        switch (bpdu->cbu_bpdutype) {
                case BSTP_MSGTYPE_CFG:
                        bpdu->cbu_protover = BSTP_PROTO_STP;
                        m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_STP_LEN;
                        eh->ether_type = htons(BSTP_BPDU_STP_LEN);
                        memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
                            BSTP_BPDU_STP_LEN);
                        break;

                case BSTP_MSGTYPE_RSTP:
                        bpdu->cbu_protover = BSTP_PROTO_RSTP;
                        bpdu->cbu_versionlen = htons(0);
                        m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_RSTP_LEN;
                        eh->ether_type = htons(BSTP_BPDU_RSTP_LEN);
                        memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
                            BSTP_BPDU_RSTP_LEN);
                        break;

                default:
                        panic("not implemented");
        }
        m->m_pkthdr.rcvif = ifp;
        m->m_len = m->m_pkthdr.len;

        bp->bp_txcount++;
        ifp->if_transmit(ifp, m);
}

static int
bstp_pdu_flags(struct bstp_port *bp)
{
        int flags = 0;

        if (bp->bp_proposing && bp->bp_state != BSTP_IFSTATE_FORWARDING)
                flags |= BSTP_PDU_F_P;

        if (bp->bp_agree)
                flags |= BSTP_PDU_F_A;

        if (bp->bp_tc_timer.active)
                flags |= BSTP_PDU_F_TC;

        if (bp->bp_tc_ack)
                flags |= BSTP_PDU_F_TCA;

        switch (bp->bp_state) {
                case BSTP_IFSTATE_LEARNING:
                        flags |= BSTP_PDU_F_L;
                        break;

                case BSTP_IFSTATE_FORWARDING:
                        flags |= (BSTP_PDU_F_L | BSTP_PDU_F_F);
                        break;
        }

        switch (bp->bp_role) {
                case BSTP_ROLE_ROOT:
                        flags |=
                                (BSTP_PDU_F_ROOT << BSTP_PDU_PRSHIFT);
                        break;

                case BSTP_ROLE_ALTERNATE:
                case BSTP_ROLE_BACKUP:  /* fall through */
                        flags |=
                                (BSTP_PDU_F_ALT << BSTP_PDU_PRSHIFT);
                        break;

                case BSTP_ROLE_DESIGNATED:
                        flags |=
                                (BSTP_PDU_F_DESG << BSTP_PDU_PRSHIFT);
                        break;
        }

        /* Strip off unused flags in either mode */
        switch (bp->bp_protover) {
                case BSTP_PROTO_STP:
                        flags &= BSTP_PDU_STPMASK;
                        break;
                case BSTP_PROTO_RSTP:
                        flags &= BSTP_PDU_RSTPMASK;
                        break;
        }
        return (flags);
}

void
bstp_input(struct bstp_port *bp, struct ifnet *ifp, struct mbuf *m)
{
        struct bstp_state *bs = bp->bp_bs;
        struct ether_header *eh;
        struct bstp_tbpdu tpdu;
        uint16_t len;

        if (bp->bp_active == 0) {
                m_freem(m);
                return;
        }

        BSTP_LOCK(bs);

        eh = mtod(m, struct ether_header *);

        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));

        /* basic packet checks */
        if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
            tpdu.tbu_ssap != LLC_8021D_LSAP ||
            tpdu.tbu_ctl != LLC_UI)
                goto out;
        if (tpdu.tbu_protoid != BSTP_PROTO_ID)
                goto out;

        /*
         * We can treat later versions of the PDU as the same as the maximum
         * version we implement. All additional parameters/flags are ignored.
         */
        if (tpdu.tbu_protover > BSTP_PROTO_MAX)
                tpdu.tbu_protover = BSTP_PROTO_MAX;

        if (tpdu.tbu_protover != bp->bp_protover) {
                /*
                 * Wait for the migration delay timer to expire before changing
                 * protocol version to avoid flip-flops.
                 */
                if (bp->bp_flags & BSTP_PORT_CANMIGRATE)
                        bstp_set_port_proto(bp, tpdu.tbu_protover);
                else
                        goto out;
        }

        /* Clear operedge upon receiving a PDU on the port */
        bp->bp_operedge = 0;
        bstp_timer_start(&bp->bp_edge_delay_timer,
            BSTP_DEFAULT_MIGRATE_DELAY);

        switch (tpdu.tbu_protover) {
                case BSTP_PROTO_STP:
                        bstp_received_stp(bs, bp, &m, &tpdu);
                        break;

                case BSTP_PROTO_RSTP:
                        bstp_received_rstp(bs, bp, &m, &tpdu);
                        break;
        }
out:
        BSTP_UNLOCK(bs);
        if (m)
                m_freem(m);
}

static void
bstp_received_stp(struct bstp_state *bs, struct bstp_port *bp,
    struct mbuf **mp, struct bstp_tbpdu *tpdu)
{
        struct bstp_cbpdu cpdu;
        struct bstp_config_unit *cu = &bp->bp_msg_cu;
        struct bstp_tcn_unit tu;

        switch (tpdu->tbu_bpdutype) {
        case BSTP_MSGTYPE_TCN:
                tu.tu_message_type = tpdu->tbu_bpdutype;
                bstp_received_tcn(bs, bp, &tu);
                break;
        case BSTP_MSGTYPE_CFG:
                if ((*mp)->m_len < BSTP_BPDU_STP_LEN &&
                    (*mp = m_pullup(*mp, BSTP_BPDU_STP_LEN)) == NULL)
                        return;
                memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_STP_LEN);

                bstp_decode_bpdu(bp, &cpdu, cu);
                bstp_received_bpdu(bs, bp, cu);
                break;
        }
}

static void
bstp_received_rstp(struct bstp_state *bs, struct bstp_port *bp,
    struct mbuf **mp, struct bstp_tbpdu *tpdu)
{
        struct bstp_cbpdu cpdu;
        struct bstp_config_unit *cu = &bp->bp_msg_cu;

        if (tpdu->tbu_bpdutype != BSTP_MSGTYPE_RSTP)
                return;

        if ((*mp)->m_len < BSTP_BPDU_RSTP_LEN &&
            (*mp = m_pullup(*mp, BSTP_BPDU_RSTP_LEN)) == NULL)
                return;
        memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_RSTP_LEN);

        bstp_decode_bpdu(bp, &cpdu, cu);
        bstp_received_bpdu(bs, bp, cu);
}

static void
bstp_received_tcn(struct bstp_state *bs, struct bstp_port *bp,
    struct bstp_tcn_unit *tcn)
{
        bp->bp_rcvdtcn = 1;
        bstp_update_tc(bp);
}

static void
bstp_received_bpdu(struct bstp_state *bs, struct bstp_port *bp,
    struct bstp_config_unit *cu)
{
        int type;

        BSTP_LOCK_ASSERT(bs);

        /* We need to have transitioned to INFO_MINE before proceeding */
        switch (bp->bp_infois) {
                case BSTP_INFO_DISABLED:
                case BSTP_INFO_AGED:
                        return;
        }

        /* range checks */
        if (cu->cu_message_age >= cu->cu_max_age) {
                return;
        }
        if (cu->cu_max_age < BSTP_MIN_MAX_AGE ||
            cu->cu_max_age > BSTP_MAX_MAX_AGE) {
                return;
        }
        if (cu->cu_forward_delay < BSTP_MIN_FORWARD_DELAY ||
            cu->cu_forward_delay > BSTP_MAX_FORWARD_DELAY) {
                return;
        }
        if (cu->cu_hello_time < BSTP_MIN_HELLO_TIME ||
            cu->cu_hello_time > BSTP_MAX_HELLO_TIME) {
                return;
        }

        type = bstp_pdu_rcvtype(bp, cu);

        switch (type) {
                case BSTP_PDU_SUPERIOR:
                        bs->bs_allsynced = 0;
                        bp->bp_agreed = 0;
                        bp->bp_proposing = 0;

                        if (cu->cu_proposal && cu->cu_forwarding == 0)
                                bp->bp_proposed = 1;
                        if (cu->cu_topology_change)
                                bp->bp_rcvdtc = 1;
                        if (cu->cu_topology_change_ack)
                                bp->bp_rcvdtca = 1;

                        if (bp->bp_agree &&
                            !bstp_pdu_bettersame(bp, BSTP_INFO_RECEIVED))
                                bp->bp_agree = 0;

                        /* copy the received priority and timers to the port */
                        bp->bp_port_pv = cu->cu_pv;
                        bp->bp_port_msg_age = cu->cu_message_age;
                        bp->bp_port_max_age = cu->cu_max_age;
                        bp->bp_port_fdelay = cu->cu_forward_delay;
                        bp->bp_port_htime =
                                (cu->cu_hello_time > BSTP_MIN_HELLO_TIME ?
                                 cu->cu_hello_time : BSTP_MIN_HELLO_TIME);

                        /* set expiry for the new info */
                        bstp_set_timer_msgage(bp);

                        bp->bp_infois = BSTP_INFO_RECEIVED;
                        bstp_assign_roles(bs);
                        break;

                case BSTP_PDU_REPEATED:
                        if (cu->cu_proposal && cu->cu_forwarding == 0)
                                bp->bp_proposed = 1;
                        if (cu->cu_topology_change)
                                bp->bp_rcvdtc = 1;
                        if (cu->cu_topology_change_ack)
                                bp->bp_rcvdtca = 1;

                        /* rearm the age timer */
                        bstp_set_timer_msgage(bp);
                        break;

                case BSTP_PDU_INFERIOR:
                        if (cu->cu_learning) {
                                bp->bp_agreed = 1;
                                bp->bp_proposing = 0;
                        }
                        break;

                case BSTP_PDU_INFERIORALT:
                        /*
                         * only point to point links are allowed fast
                         * transitions to forwarding.
                         */
                        if (cu->cu_agree && bp->bp_ptp_link) {
                                bp->bp_agreed = 1;
                                bp->bp_proposing = 0;
                        } else
                                bp->bp_agreed = 0;

                        if (cu->cu_topology_change)
                                bp->bp_rcvdtc = 1;
                        if (cu->cu_topology_change_ack)
                                bp->bp_rcvdtca = 1;
                        break;

                case BSTP_PDU_OTHER:
                        return; /* do nothing */
        }
        /* update the state machines with the new data */
        bstp_update_state(bs, bp);
}

static int
bstp_pdu_rcvtype(struct bstp_port *bp, struct bstp_config_unit *cu)
{
        int type;

        /* default return type */
        type = BSTP_PDU_OTHER;

        switch (cu->cu_role) {
        case BSTP_ROLE_DESIGNATED:
                if (bstp_info_superior(&bp->bp_port_pv, &cu->cu_pv))
                        /* bpdu priority is superior */
                        type = BSTP_PDU_SUPERIOR;
                else if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) ==
                    INFO_SAME) {
                        if (bp->bp_port_msg_age != cu->cu_message_age ||
                            bp->bp_port_max_age != cu->cu_max_age ||
                            bp->bp_port_fdelay != cu->cu_forward_delay ||
                            bp->bp_port_htime != cu->cu_hello_time)
                                /* bpdu priority is equal and timers differ */
                                type = BSTP_PDU_SUPERIOR;
                        else
                                /* bpdu is equal */
                                type = BSTP_PDU_REPEATED;
                } else
                        /* bpdu priority is worse */
                        type = BSTP_PDU_INFERIOR;

                break;

        case BSTP_ROLE_ROOT:
        case BSTP_ROLE_ALTERNATE:
        case BSTP_ROLE_BACKUP:
                if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) <= INFO_SAME)
                        /*
                         * not a designated port and priority is the same or
                         * worse
                         */
                        type = BSTP_PDU_INFERIORALT;
                break;
        }

        return (type);
}

static int
bstp_pdu_bettersame(struct bstp_port *bp, int newinfo)
{
        if (newinfo == BSTP_INFO_RECEIVED &&
            bp->bp_infois == BSTP_INFO_RECEIVED &&
            bstp_info_cmp(&bp->bp_port_pv, &bp->bp_msg_cu.cu_pv) >= INFO_SAME)
                return (1);

        if (newinfo == BSTP_INFO_MINE &&
            bp->bp_infois == BSTP_INFO_MINE &&
            bstp_info_cmp(&bp->bp_port_pv, &bp->bp_desg_pv) >= INFO_SAME)
                return (1);

        return (0);
}

static int
bstp_info_cmp(struct bstp_pri_vector *pv,
    struct bstp_pri_vector *cpv)
{
        if (cpv->pv_root_id < pv->pv_root_id)
                return (INFO_BETTER);
        if (cpv->pv_root_id > pv->pv_root_id)
                return (INFO_WORSE);

        if (cpv->pv_cost < pv->pv_cost)
                return (INFO_BETTER);
        if (cpv->pv_cost > pv->pv_cost)
                return (INFO_WORSE);

        if (cpv->pv_dbridge_id < pv->pv_dbridge_id)
                return (INFO_BETTER);
        if (cpv->pv_dbridge_id > pv->pv_dbridge_id)
                return (INFO_WORSE);

        if (cpv->pv_dport_id < pv->pv_dport_id)
                return (INFO_BETTER);
        if (cpv->pv_dport_id > pv->pv_dport_id)
                return (INFO_WORSE);

        return (INFO_SAME);
}

/*
 * This message priority vector is superior to the port priority vector and
 * will replace it if, and only if, the message priority vector is better than
 * the port priority vector, or the message has been transmitted from the same
 * designated bridge and designated port as the port priority vector.
 */
static int
bstp_info_superior(struct bstp_pri_vector *pv,
    struct bstp_pri_vector *cpv)
{
        if (bstp_info_cmp(pv, cpv) == INFO_BETTER ||
            (bstp_same_bridgeid(pv->pv_dbridge_id, cpv->pv_dbridge_id) &&
            (cpv->pv_dport_id & 0xfff) == (pv->pv_dport_id & 0xfff)))
                return (1);
        return (0);
}

static void
bstp_assign_roles(struct bstp_state *bs)
{
        struct bstp_port *bp, *rbp = NULL;
        struct bstp_pri_vector pv;

        /* default to our priority vector */
        bs->bs_root_pv = bs->bs_bridge_pv;
        bs->bs_root_msg_age = 0;
        bs->bs_root_max_age = bs->bs_bridge_max_age;
        bs->bs_root_fdelay = bs->bs_bridge_fdelay;
        bs->bs_root_htime = bs->bs_bridge_htime;
        bs->bs_root_port = NULL;

        /* check if any received info supersedes us */
        LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                if (bp->bp_infois != BSTP_INFO_RECEIVED)
                        continue;

                pv = bp->bp_port_pv;
                pv.pv_cost += bp->bp_path_cost;

                /*
                 * The root priority vector is the best of the set comprising
                 * the bridge priority vector plus all root path priority
                 * vectors whose bridge address is not equal to us.
                 */
                if (bstp_same_bridgeid(pv.pv_dbridge_id,
                    bs->bs_bridge_pv.pv_dbridge_id) == 0 &&
                    bstp_info_cmp(&bs->bs_root_pv, &pv) == INFO_BETTER) {
                        /* the port vector replaces the root */
                        bs->bs_root_pv = pv;
                        bs->bs_root_msg_age = bp->bp_port_msg_age +
                            BSTP_MESSAGE_AGE_INCR;
                        bs->bs_root_max_age = bp->bp_port_max_age;
                        bs->bs_root_fdelay = bp->bp_port_fdelay;
                        bs->bs_root_htime = bp->bp_port_htime;
                        rbp = bp;
                }
        }

        LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                /* calculate the port designated vector */
                bp->bp_desg_pv.pv_root_id = bs->bs_root_pv.pv_root_id;
                bp->bp_desg_pv.pv_cost = bs->bs_root_pv.pv_cost;
                bp->bp_desg_pv.pv_dbridge_id = bs->bs_bridge_pv.pv_dbridge_id;
                bp->bp_desg_pv.pv_dport_id = bp->bp_port_id;
                bp->bp_desg_pv.pv_port_id = bp->bp_port_id;

                /* calculate designated times */
                bp->bp_desg_msg_age = bs->bs_root_msg_age;
                bp->bp_desg_max_age = bs->bs_root_max_age;
                bp->bp_desg_fdelay = bs->bs_root_fdelay;
                bp->bp_desg_htime = bs->bs_bridge_htime;

                switch (bp->bp_infois) {
                case BSTP_INFO_DISABLED:
                        bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
                        break;

                case BSTP_INFO_AGED:
                        bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
                        bstp_update_info(bp);
                        break;

                case BSTP_INFO_MINE:
                        bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
                        /* update the port info if stale */
                        if (bstp_info_cmp(&bp->bp_port_pv,
                            &bp->bp_desg_pv) != INFO_SAME ||
                            (rbp != NULL &&
                            (bp->bp_port_msg_age != rbp->bp_port_msg_age ||
                            bp->bp_port_max_age != rbp->bp_port_max_age ||
                            bp->bp_port_fdelay != rbp->bp_port_fdelay ||
                            bp->bp_port_htime != rbp->bp_port_htime)))
                                bstp_update_info(bp);
                        break;

                case BSTP_INFO_RECEIVED:
                        if (bp == rbp) {
                                /*
                                 * root priority is derived from this
                                 * port, make it the root port.
                                 */
                                bstp_set_port_role(bp, BSTP_ROLE_ROOT);
                                bs->bs_root_port = bp;
                        } else if (bstp_info_cmp(&bp->bp_port_pv,
                                    &bp->bp_desg_pv) == INFO_BETTER) {
                                /*
                                 * the port priority is lower than the root
                                 * port.
                                 */
                                bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
                                bstp_update_info(bp);
                        } else {
                                if (bstp_same_bridgeid(
                                    bp->bp_port_pv.pv_dbridge_id,
                                    bs->bs_bridge_pv.pv_dbridge_id)) {
                                        /*
                                         * the designated bridge refers to
                                         * another port on this bridge.
                                         */
                                        bstp_set_port_role(bp,
                                            BSTP_ROLE_BACKUP);
                                } else {
                                        /*
                                         * the port is an inferior path to the
                                         * root bridge.
                                         */
                                        bstp_set_port_role(bp,
                                            BSTP_ROLE_ALTERNATE);
                                }
                        }
                        break;
                }
        }
}

static void
bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
{
        struct bstp_port *bp2;
        int synced;

        BSTP_LOCK_ASSERT(bs);

        /* check if all the ports have syncronised again */
        if (!bs->bs_allsynced) {
                synced = 1;
                LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
                        if (!(bp2->bp_synced ||
                             bp2->bp_role == BSTP_ROLE_ROOT)) {
                                synced = 0;
                                break;
                        }
                }
                bs->bs_allsynced = synced;
        }

        bstp_update_roles(bs, bp);
        bstp_update_tc(bp);
}

static void
bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
{
        NET_EPOCH_ASSERT();

        switch (bp->bp_role) {
        case BSTP_ROLE_DISABLED:
                /* Clear any flags if set */
                if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
                        bp->bp_sync = 0;
                        bp->bp_synced = 1;
                        bp->bp_reroot = 0;
                }
                break;

        case BSTP_ROLE_ALTERNATE:
        case BSTP_ROLE_BACKUP:
                if ((bs->bs_allsynced && !bp->bp_agree) ||
                    (bp->bp_proposed && bp->bp_agree)) {
                        bp->bp_proposed = 0;
                        bp->bp_agree = 1;
                        bp->bp_flags |= BSTP_PORT_NEWINFO;
                        DPRINTF("%s -> ALTERNATE_AGREED\n",
                            bp->bp_ifp->if_xname);
                }

                if (bp->bp_proposed && !bp->bp_agree) {
                        bstp_set_all_sync(bs);
                        bp->bp_proposed = 0;
                        DPRINTF("%s -> ALTERNATE_PROPOSED\n",
                            bp->bp_ifp->if_xname);
                }

                /* Clear any flags if set */
                if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
                        bp->bp_sync = 0;
                        bp->bp_synced = 1;
                        bp->bp_reroot = 0;
                        DPRINTF("%s -> ALTERNATE_PORT\n", bp->bp_ifp->if_xname);
                }
                break;

        case BSTP_ROLE_ROOT:
                if (bp->bp_state != BSTP_IFSTATE_FORWARDING && !bp->bp_reroot) {
                        bstp_set_all_reroot(bs);
                        DPRINTF("%s -> ROOT_REROOT\n", bp->bp_ifp->if_xname);
                }

                if ((bs->bs_allsynced && !bp->bp_agree) ||
                    (bp->bp_proposed && bp->bp_agree)) {
                        bp->bp_proposed = 0;
                        bp->bp_sync = 0;
                        bp->bp_agree = 1;
                        bp->bp_flags |= BSTP_PORT_NEWINFO;
                        DPRINTF("%s -> ROOT_AGREED\n", bp->bp_ifp->if_xname);
                }

                if (bp->bp_proposed && !bp->bp_agree) {
                        bstp_set_all_sync(bs);
                        bp->bp_proposed = 0;
                        DPRINTF("%s -> ROOT_PROPOSED\n", bp->bp_ifp->if_xname);
                }

                if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
                    (bp->bp_forward_delay_timer.active == 0 ||
                    (bstp_rerooted(bs, bp) &&
                    bp->bp_recent_backup_timer.active == 0 &&
                    bp->bp_protover == BSTP_PROTO_RSTP))) {
                        switch (bp->bp_state) {
                        case BSTP_IFSTATE_DISCARDING:
                                bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
                                break;
                        case BSTP_IFSTATE_LEARNING:
                                bstp_set_port_state(bp,
                                    BSTP_IFSTATE_FORWARDING);
                                break;
                        }
                }

                if (bp->bp_state == BSTP_IFSTATE_FORWARDING && bp->bp_reroot) {
                        bp->bp_reroot = 0;
                        DPRINTF("%s -> ROOT_REROOTED\n", bp->bp_ifp->if_xname);
                }
                break;

        case BSTP_ROLE_DESIGNATED:
                if (bp->bp_recent_root_timer.active == 0 && bp->bp_reroot) {
                        bp->bp_reroot = 0;
                        DPRINTF("%s -> DESIGNATED_RETIRED\n",
                            bp->bp_ifp->if_xname);
                }

                if ((bp->bp_state == BSTP_IFSTATE_DISCARDING &&
                    !bp->bp_synced) || (bp->bp_agreed && !bp->bp_synced) ||
                    (bp->bp_operedge && !bp->bp_synced) ||
                    (bp->bp_sync && bp->bp_synced)) {
                        bstp_timer_stop(&bp->bp_recent_root_timer);
                        bp->bp_synced = 1;
                        bp->bp_sync = 0;
                        DPRINTF("%s -> DESIGNATED_SYNCED\n",
                            bp->bp_ifp->if_xname);
                }

                if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
                    !bp->bp_agreed && !bp->bp_proposing &&
                    !bp->bp_operedge) {
                        bp->bp_proposing = 1;
                        bp->bp_flags |= BSTP_PORT_NEWINFO;
                        bstp_timer_start(&bp->bp_edge_delay_timer,
                            (bp->bp_ptp_link ? BSTP_DEFAULT_MIGRATE_DELAY :
                             bp->bp_desg_max_age));
                        DPRINTF("%s -> DESIGNATED_PROPOSE\n",
                            bp->bp_ifp->if_xname);
                }

                if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
                    (bp->bp_forward_delay_timer.active == 0 || bp->bp_agreed ||
                    bp->bp_operedge) &&
                    (bp->bp_recent_root_timer.active == 0 || !bp->bp_reroot) &&
                    !bp->bp_sync) {
                        if (bp->bp_agreed)
                                DPRINTF("%s -> AGREED\n", bp->bp_ifp->if_xname);
                        /*
                         * If agreed|operedge then go straight to forwarding,
                         * otherwise follow discard -> learn -> forward.
                         */
                        if (bp->bp_agreed || bp->bp_operedge ||
                            bp->bp_state == BSTP_IFSTATE_LEARNING) {
                                bstp_set_port_state(bp,
                                    BSTP_IFSTATE_FORWARDING);
                                bp->bp_agreed = bp->bp_protover;
                        } else if (bp->bp_state == BSTP_IFSTATE_DISCARDING)
                                bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
                }

                if (((bp->bp_sync && !bp->bp_synced) ||
                    (bp->bp_reroot && bp->bp_recent_root_timer.active) ||
                    (bp->bp_flags & BSTP_PORT_DISPUTED)) && !bp->bp_operedge &&
                    bp->bp_state != BSTP_IFSTATE_DISCARDING) {
                        bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
                        bp->bp_flags &= ~BSTP_PORT_DISPUTED;
                        bstp_timer_start(&bp->bp_forward_delay_timer,
                            bp->bp_protover == BSTP_PROTO_RSTP ?
                            bp->bp_desg_htime : bp->bp_desg_fdelay);
                        DPRINTF("%s -> DESIGNATED_DISCARD\n",
                            bp->bp_ifp->if_xname);
                }
                break;
        }

        if (bp->bp_flags & BSTP_PORT_NEWINFO)
                bstp_transmit(bs, bp);
}

static void
bstp_update_tc(struct bstp_port *bp)
{
        switch (bp->bp_tcstate) {
                case BSTP_TCSTATE_ACTIVE:
                        if ((bp->bp_role != BSTP_ROLE_DESIGNATED &&
                            bp->bp_role != BSTP_ROLE_ROOT) || bp->bp_operedge)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);

                        if (bp->bp_rcvdtcn)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_TCN);
                        if (bp->bp_rcvdtc)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_TC);

                        if (bp->bp_tc_prop && !bp->bp_operedge)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_PROPAG);

                        if (bp->bp_rcvdtca)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_ACK);
                        break;

                case BSTP_TCSTATE_INACTIVE:
                        if ((bp->bp_state == BSTP_IFSTATE_LEARNING ||
                            bp->bp_state == BSTP_IFSTATE_FORWARDING) &&
                            bp->bp_fdbflush == 0)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
                        break;

                case BSTP_TCSTATE_LEARNING:
                        if (bp->bp_rcvdtc || bp->bp_rcvdtcn || bp->bp_rcvdtca ||
                            bp->bp_tc_prop)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
                        else if (bp->bp_role != BSTP_ROLE_DESIGNATED &&
                                 bp->bp_role != BSTP_ROLE_ROOT &&
                                 bp->bp_state == BSTP_IFSTATE_DISCARDING)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);

                        if ((bp->bp_role == BSTP_ROLE_DESIGNATED ||
                            bp->bp_role == BSTP_ROLE_ROOT) &&
                            bp->bp_state == BSTP_IFSTATE_FORWARDING &&
                            !bp->bp_operedge)
                                bstp_set_port_tc(bp, BSTP_TCSTATE_DETECTED);
                        break;

                /* these are transient states and go straight back to ACTIVE */
                case BSTP_TCSTATE_DETECTED:
                case BSTP_TCSTATE_TCN:
                case BSTP_TCSTATE_TC:
                case BSTP_TCSTATE_PROPAG:
                case BSTP_TCSTATE_ACK:
                        DPRINTF("Invalid TC state for %s\n",
                            bp->bp_ifp->if_xname);
                        break;
        }

}

static void
bstp_update_info(struct bstp_port *bp)
{
        struct bstp_state *bs = bp->bp_bs;

        bp->bp_proposing = 0;
        bp->bp_proposed = 0;

        if (bp->bp_agreed && !bstp_pdu_bettersame(bp, BSTP_INFO_MINE))
                bp->bp_agreed = 0;

        if (bp->bp_synced && !bp->bp_agreed) {
                bp->bp_synced = 0;
                bs->bs_allsynced = 0;
        }

        /* copy the designated pv to the port */
        bp->bp_port_pv = bp->bp_desg_pv;
        bp->bp_port_msg_age = bp->bp_desg_msg_age;
        bp->bp_port_max_age = bp->bp_desg_max_age;
        bp->bp_port_fdelay = bp->bp_desg_fdelay;
        bp->bp_port_htime = bp->bp_desg_htime;
        bp->bp_infois = BSTP_INFO_MINE;

        /* Set transmit flag but do not immediately send */
        bp->bp_flags |= BSTP_PORT_NEWINFO;
}

/* set tcprop on every port other than the caller */
static void
bstp_set_other_tcprop(struct bstp_port *bp)
{
        struct bstp_state *bs = bp->bp_bs;
        struct bstp_port *bp2;

        BSTP_LOCK_ASSERT(bs);

        LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
                if (bp2 == bp)
                        continue;
                bp2->bp_tc_prop = 1;
        }
}

static void
bstp_set_all_reroot(struct bstp_state *bs)
{
        struct bstp_port *bp;

        BSTP_LOCK_ASSERT(bs);

        LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
                bp->bp_reroot = 1;
}

static void
bstp_set_all_sync(struct bstp_state *bs)
{
        struct bstp_port *bp;

        BSTP_LOCK_ASSERT(bs);

        LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                bp->bp_sync = 1;
                bp->bp_synced = 0;      /* Not explicit in spec */
        }

        bs->bs_allsynced = 0;
}

static void
bstp_set_port_state(struct bstp_port *bp, int state)
{
        if (bp->bp_state == state)
                return;

        bp->bp_state = state;

        switch (bp->bp_state) {
                case BSTP_IFSTATE_DISCARDING:
                        DPRINTF("state changed to DISCARDING on %s\n",
                            bp->bp_ifp->if_xname);
                        break;

                case BSTP_IFSTATE_LEARNING:
                        DPRINTF("state changed to LEARNING on %s\n",
                            bp->bp_ifp->if_xname);

                        bstp_timer_start(&bp->bp_forward_delay_timer,
                            bp->bp_protover == BSTP_PROTO_RSTP ?
                            bp->bp_desg_htime : bp->bp_desg_fdelay);
                        break;

                case BSTP_IFSTATE_FORWARDING:
                        DPRINTF("state changed to FORWARDING on %s\n",
                            bp->bp_ifp->if_xname);

                        bstp_timer_stop(&bp->bp_forward_delay_timer);
                        /* Record that we enabled forwarding */
                        bp->bp_forward_transitions++;
                        break;
        }

        /* notify the parent bridge */
        taskqueue_enqueue(taskqueue_swi, &bp->bp_statetask);
}

static void
bstp_set_port_role(struct bstp_port *bp, int role)
{
        struct bstp_state *bs = bp->bp_bs;

        if (bp->bp_role == role)
                return;

        /* perform pre-change tasks */
        switch (bp->bp_role) {
                case BSTP_ROLE_DISABLED:
                        bstp_timer_start(&bp->bp_forward_delay_timer,
                            bp->bp_desg_max_age);
                        break;

                case BSTP_ROLE_BACKUP:
                        bstp_timer_start(&bp->bp_recent_backup_timer,
                            bp->bp_desg_htime * 2);
                        /* fall through */
                case BSTP_ROLE_ALTERNATE:
                        bstp_timer_start(&bp->bp_forward_delay_timer,
                            bp->bp_desg_fdelay);
                        bp->bp_sync = 0;
                        bp->bp_synced = 1;
                        bp->bp_reroot = 0;
                        break;

                case BSTP_ROLE_ROOT:
                        bstp_timer_start(&bp->bp_recent_root_timer,
                            BSTP_DEFAULT_FORWARD_DELAY);
                        break;
        }

        bp->bp_role = role;
        /* clear values not carried between roles */
        bp->bp_proposing = 0;
        bs->bs_allsynced = 0;

        /* initialise the new role */
        switch (bp->bp_role) {
                case BSTP_ROLE_DISABLED:
                case BSTP_ROLE_ALTERNATE:
                case BSTP_ROLE_BACKUP:
                        DPRINTF("%s role -> ALT/BACK/DISABLED\n",
                            bp->bp_ifp->if_xname);
                        bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
                        bstp_timer_stop(&bp->bp_recent_root_timer);
                        bstp_timer_latch(&bp->bp_forward_delay_timer);
                        bp->bp_sync = 0;
                        bp->bp_synced = 1;
                        bp->bp_reroot = 0;
                        break;

                case BSTP_ROLE_ROOT:
                        DPRINTF("%s role -> ROOT\n",
                            bp->bp_ifp->if_xname);
                        bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
                        bstp_timer_latch(&bp->bp_recent_root_timer);
                        bp->bp_proposing = 0;
                        break;

                case BSTP_ROLE_DESIGNATED:
                        DPRINTF("%s role -> DESIGNATED\n",
                            bp->bp_ifp->if_xname);
                        bstp_timer_start(&bp->bp_hello_timer,
                            bp->bp_desg_htime);
                        bp->bp_agree = 0;
                        break;
        }

        /* let the TC state know that the role changed */
        bstp_update_tc(bp);
}

static void
bstp_set_port_proto(struct bstp_port *bp, int proto)
{
        struct bstp_state *bs = bp->bp_bs;

        /* supported protocol versions */
        switch (proto) {
                case BSTP_PROTO_STP:
                        /* we can downgrade protocols only */
                        bstp_timer_stop(&bp->bp_migrate_delay_timer);
                        /* clear unsupported features */
                        bp->bp_operedge = 0;
                        /* STP compat mode only uses 16 bits of the 32 */
                        if (bp->bp_path_cost > 65535)
                                bp->bp_path_cost = 65535;
                        break;

                case BSTP_PROTO_RSTP:
                        bstp_timer_start(&bp->bp_migrate_delay_timer,
                            bs->bs_migration_delay);
                        break;

                default:
                        DPRINTF("Unsupported STP version %d\n", proto);
                        return;
        }

        bp->bp_protover = proto;
        bp->bp_flags &= ~BSTP_PORT_CANMIGRATE;
}

static void
bstp_set_port_tc(struct bstp_port *bp, int state)
{
        struct bstp_state *bs = bp->bp_bs;

        bp->bp_tcstate = state;

        /* initialise the new state */
        switch (bp->bp_tcstate) {
                case BSTP_TCSTATE_ACTIVE:
                        DPRINTF("%s -> TC_ACTIVE\n", bp->bp_ifp->if_xname);
                        /* nothing to do */
                        break;

                case BSTP_TCSTATE_INACTIVE:
                        bstp_timer_stop(&bp->bp_tc_timer);
                        /* flush routes on the parent bridge */
                        bp->bp_fdbflush = 1;
                        taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
                        bp->bp_tc_ack = 0;
                        DPRINTF("%s -> TC_INACTIVE\n", bp->bp_ifp->if_xname);
                        break;

                case BSTP_TCSTATE_LEARNING:
                        bp->bp_rcvdtc = 0;
                        bp->bp_rcvdtcn = 0;
                        bp->bp_rcvdtca = 0;
                        bp->bp_tc_prop = 0;
                        DPRINTF("%s -> TC_LEARNING\n", bp->bp_ifp->if_xname);
                        break;

                case BSTP_TCSTATE_DETECTED:
                        bstp_set_timer_tc(bp);
                        bstp_set_other_tcprop(bp);
                        /* send out notification */
                        bp->bp_flags |= BSTP_PORT_NEWINFO;
                        bstp_transmit(bs, bp);
                        getmicrotime(&bs->bs_last_tc_time);
                        DPRINTF("%s -> TC_DETECTED\n", bp->bp_ifp->if_xname);
                        bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
                        break;

                case BSTP_TCSTATE_TCN:
                        bstp_set_timer_tc(bp);
                        DPRINTF("%s -> TC_TCN\n", bp->bp_ifp->if_xname);
                        /* fall through */
                case BSTP_TCSTATE_TC:
                        bp->bp_rcvdtc = 0;
                        bp->bp_rcvdtcn = 0;
                        if (bp->bp_role == BSTP_ROLE_DESIGNATED)
                                bp->bp_tc_ack = 1;

                        bstp_set_other_tcprop(bp);
                        DPRINTF("%s -> TC_TC\n", bp->bp_ifp->if_xname);
                        bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
                        break;

                case BSTP_TCSTATE_PROPAG:
                        /* flush routes on the parent bridge */
                        bp->bp_fdbflush = 1;
                        taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
                        bp->bp_tc_prop = 0;
                        bstp_set_timer_tc(bp);
                        DPRINTF("%s -> TC_PROPAG\n", bp->bp_ifp->if_xname);
                        bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
                        break;

                case BSTP_TCSTATE_ACK:
                        bstp_timer_stop(&bp->bp_tc_timer);
                        bp->bp_rcvdtca = 0;
                        DPRINTF("%s -> TC_ACK\n", bp->bp_ifp->if_xname);
                        bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
                        break;
        }
}

static void
bstp_set_timer_tc(struct bstp_port *bp)
{
        struct bstp_state *bs = bp->bp_bs;

        if (bp->bp_tc_timer.active)
                return;

        switch (bp->bp_protover) {
                case BSTP_PROTO_RSTP:
                        bstp_timer_start(&bp->bp_tc_timer,
                            bp->bp_desg_htime + BSTP_TICK_VAL);
                        bp->bp_flags |= BSTP_PORT_NEWINFO;
                        break;

                case BSTP_PROTO_STP:
                        bstp_timer_start(&bp->bp_tc_timer,
                            bs->bs_root_max_age + bs->bs_root_fdelay);
                        break;
        }
}

static void
bstp_set_timer_msgage(struct bstp_port *bp)
{
        if (bp->bp_port_msg_age + BSTP_MESSAGE_AGE_INCR <=
            bp->bp_port_max_age) {
                bstp_timer_start(&bp->bp_message_age_timer,
                    bp->bp_port_htime * 3);
        } else
                /* expires immediately */
                bstp_timer_start(&bp->bp_message_age_timer, 0);
}

static int
bstp_rerooted(struct bstp_state *bs, struct bstp_port *bp)
{
        struct bstp_port *bp2;
        int rr_set = 0;

        LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
                if (bp2 == bp)
                        continue;
                if (bp2->bp_recent_root_timer.active) {
                        rr_set = 1;
                        break;
                }
        }
        return (!rr_set);
}

int
bstp_set_htime(struct bstp_state *bs, int t)
{
        /* convert seconds to ticks */
        t *=  BSTP_TICK_VAL;

        /* value can only be changed in leagacy stp mode */
        if (bs->bs_protover != BSTP_PROTO_STP)
                return (EPERM);

        if (t < BSTP_MIN_HELLO_TIME || t > BSTP_MAX_HELLO_TIME)
                return (EINVAL);

        BSTP_LOCK(bs);
        bs->bs_bridge_htime = t;
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_fdelay(struct bstp_state *bs, int t)
{
        /* convert seconds to ticks */
        t *= BSTP_TICK_VAL;

        if (t < BSTP_MIN_FORWARD_DELAY || t > BSTP_MAX_FORWARD_DELAY)
                return (EINVAL);

        BSTP_LOCK(bs);
        bs->bs_bridge_fdelay = t;
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_maxage(struct bstp_state *bs, int t)
{
        /* convert seconds to ticks */
        t *= BSTP_TICK_VAL;

        if (t < BSTP_MIN_MAX_AGE || t > BSTP_MAX_MAX_AGE)
                return (EINVAL);

        BSTP_LOCK(bs);
        bs->bs_bridge_max_age = t;
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_holdcount(struct bstp_state *bs, int count)
{
        struct bstp_port *bp;

        if (count < BSTP_MIN_HOLD_COUNT ||
            count > BSTP_MAX_HOLD_COUNT)
                return (EINVAL);

        BSTP_LOCK(bs);
        bs->bs_txholdcount = count;
        LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
                bp->bp_txcount = 0;
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_protocol(struct bstp_state *bs, int proto)
{
        struct bstp_port *bp;

        switch (proto) {
                /* Supported protocol versions */
                case BSTP_PROTO_STP:
                case BSTP_PROTO_RSTP:
                        break;

                default:
                        return (EINVAL);
        }

        BSTP_LOCK(bs);
        bs->bs_protover = proto;
        bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
        LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                /* reinit state */
                bp->bp_infois = BSTP_INFO_DISABLED;
                bp->bp_txcount = 0;
                bstp_set_port_proto(bp, bs->bs_protover);
                bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
                bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
                bstp_timer_stop(&bp->bp_recent_backup_timer);
        }
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_priority(struct bstp_state *bs, int pri)
{
        if (pri < 0 || pri > BSTP_MAX_PRIORITY)
                return (EINVAL);

        /* Limit to steps of 4096 */
        pri -= pri % 4096;

        BSTP_LOCK(bs);
        bs->bs_bridge_priority = pri;
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_port_priority(struct bstp_port *bp, int pri)
{
        struct bstp_state *bs = bp->bp_bs;

        if (pri < 0 || pri > BSTP_MAX_PORT_PRIORITY)
                return (EINVAL);

        /* Limit to steps of 16 */
        pri -= pri % 16;

        BSTP_LOCK(bs);
        bp->bp_priority = pri;
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
{
        struct bstp_state *bs = bp->bp_bs;

        if (path_cost > BSTP_MAX_PATH_COST)
                return (EINVAL);

        /* STP compat mode only uses 16 bits of the 32 */
        if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
                path_cost = 65535;

        BSTP_LOCK(bs);

        if (path_cost == 0) {   /* use auto */
                bp->bp_flags &= ~BSTP_PORT_ADMCOST;
                bp->bp_path_cost = bstp_calc_path_cost(bp);
        } else {
                bp->bp_path_cost = path_cost;
                bp->bp_flags |= BSTP_PORT_ADMCOST;
        }
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_edge(struct bstp_port *bp, int set)
{
        struct bstp_state *bs = bp->bp_bs;

        BSTP_LOCK(bs);
        if ((bp->bp_operedge = set) == 0)
                bp->bp_flags &= ~BSTP_PORT_ADMEDGE;
        else
                bp->bp_flags |= BSTP_PORT_ADMEDGE;
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_autoedge(struct bstp_port *bp, int set)
{
        struct bstp_state *bs = bp->bp_bs;

        BSTP_LOCK(bs);
        if (set) {
                bp->bp_flags |= BSTP_PORT_AUTOEDGE;
                /* we may be able to transition straight to edge */
                if (bp->bp_edge_delay_timer.active == 0)
                        bstp_edge_delay_expiry(bs, bp);
        } else
                bp->bp_flags &= ~BSTP_PORT_AUTOEDGE;
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_ptp(struct bstp_port *bp, int set)
{
        struct bstp_state *bs = bp->bp_bs;

        BSTP_LOCK(bs);
        bp->bp_ptp_link = set;
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_set_autoptp(struct bstp_port *bp, int set)
{
        struct bstp_state *bs = bp->bp_bs;

        BSTP_LOCK(bs);
        if (set) {
                bp->bp_flags |= BSTP_PORT_AUTOPTP;
                if (bp->bp_role != BSTP_ROLE_DISABLED)
                        taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
        } else
                bp->bp_flags &= ~BSTP_PORT_AUTOPTP;
        BSTP_UNLOCK(bs);
        return (0);
}

/*
 * Calculate the path cost according to the link speed.
 */
static uint32_t
bstp_calc_path_cost(struct bstp_port *bp)
{
        struct ifnet *ifp = bp->bp_ifp;
        uint32_t path_cost;

        /* If the priority has been manually set then retain the value */
        if (bp->bp_flags & BSTP_PORT_ADMCOST)
                return bp->bp_path_cost;

        if (ifp->if_link_state == LINK_STATE_DOWN) {
                /* Recalc when the link comes up again */
                bp->bp_flags |= BSTP_PORT_PNDCOST;
                return (BSTP_DEFAULT_PATH_COST);
        }

        if (ifp->if_baudrate < 1000)
                return (BSTP_DEFAULT_PATH_COST);

        /* formula from section 17.14, IEEE Std 802.1D-2004 */
        path_cost = 20000000000ULL / (ifp->if_baudrate / 1000);

        if (path_cost > BSTP_MAX_PATH_COST)
                path_cost = BSTP_MAX_PATH_COST;

        /* STP compat mode only uses 16 bits of the 32 */
        if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
                path_cost = 65535;

        return (path_cost);
}

/*
 * Notify the bridge that a port state has changed, we need to do this from a
 * taskqueue to avoid a LOR.
 */
static void
bstp_notify_state(void *arg, int pending)
{
        struct bstp_port *bp = (struct bstp_port *)arg;
        struct bstp_state *bs = bp->bp_bs;

        if (bp->bp_active == 1 && bs->bs_state_cb != NULL)
                (*bs->bs_state_cb)(bp->bp_ifp, bp->bp_state);
}

/*
 * Flush the routes on the bridge port, we need to do this from a
 * taskqueue to avoid a LOR.
 */
static void
bstp_notify_rtage(void *arg, int pending)
{
        struct bstp_port *bp = (struct bstp_port *)arg;
        struct bstp_state *bs = bp->bp_bs;
        int age = 0;

        BSTP_LOCK(bs);
        switch (bp->bp_protover) {
                case BSTP_PROTO_STP:
                        /* convert to seconds */
                        age = bp->bp_desg_fdelay / BSTP_TICK_VAL;
                        break;

                case BSTP_PROTO_RSTP:
                        age = 0;
                        break;
        }
        BSTP_UNLOCK(bs);

        if (bp->bp_active == 1 && bs->bs_rtage_cb != NULL)
                (*bs->bs_rtage_cb)(bp->bp_ifp, age);

        /* flush is complete */
        BSTP_LOCK(bs);
        bp->bp_fdbflush = 0;
        BSTP_UNLOCK(bs);
}

void
bstp_linkstate(struct bstp_port *bp)
{
        struct bstp_state *bs = bp->bp_bs;

        if (!bp->bp_active)
                return;

        bstp_ifupdstatus(bp, 0);
        BSTP_LOCK(bs);
        bstp_update_state(bs, bp);
        BSTP_UNLOCK(bs);
}

static void
bstp_ifupdstatus(void *arg, int pending)
{
        struct bstp_port *bp = (struct bstp_port *)arg;
        struct bstp_state *bs = bp->bp_bs;
        struct ifnet *ifp = bp->bp_ifp;
        struct ifmediareq ifmr;
        int error, changed;

        if (!bp->bp_active)
                return;

        bzero((char *)&ifmr, sizeof(ifmr));
        error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);

        BSTP_LOCK(bs);
        changed = 0;
        if ((error == 0) && (ifp->if_flags & IFF_UP)) {
                if (ifmr.ifm_status & IFM_ACTIVE) {
                        /* A full-duplex link is assumed to be point to point */
                        if (bp->bp_flags & BSTP_PORT_AUTOPTP) {
                                int fdx;

                                fdx = ifmr.ifm_active & IFM_FDX ? 1 : 0;
                                if (bp->bp_ptp_link ^ fdx) {
                                        bp->bp_ptp_link = fdx;
                                        changed = 1;
                                }
                        }

                        /* Calc the cost if the link was down previously */
                        if (bp->bp_flags & BSTP_PORT_PNDCOST) {
                                uint32_t cost;

                                cost = bstp_calc_path_cost(bp);
                                if (bp->bp_path_cost != cost) {
                                        bp->bp_path_cost = cost;
                                        changed = 1;
                                }
                                bp->bp_flags &= ~BSTP_PORT_PNDCOST;
                        }

                        if (bp->bp_role == BSTP_ROLE_DISABLED) {
                                bstp_enable_port(bs, bp);
                                changed = 1;
                        }
                } else {
                        if (bp->bp_role != BSTP_ROLE_DISABLED) {
                                bstp_disable_port(bs, bp);
                                changed = 1;
                                if ((bp->bp_flags & BSTP_PORT_ADMEDGE) &&
                                    bp->bp_protover == BSTP_PROTO_RSTP)
                                        bp->bp_operedge = 1;
                        }
                }
        } else if (bp->bp_infois != BSTP_INFO_DISABLED) {
                bstp_disable_port(bs, bp);
                changed = 1;
        }
        if (changed)
                bstp_assign_roles(bs);
        BSTP_UNLOCK(bs);
}

static void
bstp_enable_port(struct bstp_state *bs, struct bstp_port *bp)
{
        bp->bp_infois = BSTP_INFO_AGED;
}

static void
bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
{
        bp->bp_infois = BSTP_INFO_DISABLED;
}

static void
bstp_tick(void *arg)
{
        struct epoch_tracker et;
        struct bstp_state *bs = arg;
        struct bstp_port *bp;

        BSTP_LOCK_ASSERT(bs);

        if (bs->bs_running == 0)
                return;

        NET_EPOCH_ENTER(et);
        CURVNET_SET(bs->bs_vnet);

        /* poll link events on interfaces that do not support linkstate */
        if (bstp_timer_dectest(&bs->bs_link_timer)) {
                LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                        if (!(bp->bp_ifp->if_capabilities & IFCAP_LINKSTATE))
                                taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
                }
                bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
        }

        LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                /* no events need to happen for these */
                bstp_timer_dectest(&bp->bp_tc_timer);
                bstp_timer_dectest(&bp->bp_recent_root_timer);
                bstp_timer_dectest(&bp->bp_forward_delay_timer);
                bstp_timer_dectest(&bp->bp_recent_backup_timer);

                if (bstp_timer_dectest(&bp->bp_hello_timer))
                        bstp_hello_timer_expiry(bs, bp);

                if (bstp_timer_dectest(&bp->bp_message_age_timer))
                        bstp_message_age_expiry(bs, bp);

                if (bstp_timer_dectest(&bp->bp_migrate_delay_timer))
                        bstp_migrate_delay_expiry(bs, bp);

                if (bstp_timer_dectest(&bp->bp_edge_delay_timer))
                        bstp_edge_delay_expiry(bs, bp);

                /* update the various state machines for the port */
                bstp_update_state(bs, bp);

                if (bp->bp_txcount > 0)
                        bp->bp_txcount--;
        }

        CURVNET_RESTORE();
        NET_EPOCH_EXIT(et);

        callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
}

static void
bstp_timer_start(struct bstp_timer *t, uint16_t v)
{
        t->value = v;
        t->active = 1;
        t->latched = 0;
}

static void
bstp_timer_stop(struct bstp_timer *t)
{
        t->value = 0;
        t->active = 0;
        t->latched = 0;
}

static void
bstp_timer_latch(struct bstp_timer *t)
{
        t->latched = 1;
        t->active = 1;
}

static int
bstp_timer_dectest(struct bstp_timer *t)
{
        if (t->active == 0 || t->latched)
                return (0);
        t->value -= BSTP_TICK_VAL;
        if (t->value <= 0) {
                bstp_timer_stop(t);
                return (1);
        }
        return (0);
}

static void
bstp_hello_timer_expiry(struct bstp_state *bs, struct bstp_port *bp)
{
        if ((bp->bp_flags & BSTP_PORT_NEWINFO) ||
            bp->bp_role == BSTP_ROLE_DESIGNATED ||
            (bp->bp_role == BSTP_ROLE_ROOT &&
             bp->bp_tc_timer.active == 1)) {
                bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
                bp->bp_flags |= BSTP_PORT_NEWINFO;
                bstp_transmit(bs, bp);
        }
}

static void
bstp_message_age_expiry(struct bstp_state *bs, struct bstp_port *bp)
{
        if (bp->bp_infois == BSTP_INFO_RECEIVED) {
                bp->bp_infois = BSTP_INFO_AGED;
                bstp_assign_roles(bs);
                DPRINTF("aged info on %s\n", bp->bp_ifp->if_xname);
        }
}

static void
bstp_migrate_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
{
        bp->bp_flags |= BSTP_PORT_CANMIGRATE;
}

static void
bstp_edge_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
{
        if ((bp->bp_flags & BSTP_PORT_AUTOEDGE) &&
            bp->bp_protover == BSTP_PROTO_RSTP && bp->bp_proposing &&
            bp->bp_role == BSTP_ROLE_DESIGNATED) {
                bp->bp_operedge = 1;
                DPRINTF("%s -> edge port\n", bp->bp_ifp->if_xname);
        }
}

static int
bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
{
        int i, d;

        for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
                d = ((int)a[i]) - ((int)b[i]);
        }

        return (d);
}

/*
 * compare the bridge address component of the bridgeid
 */
static int
bstp_same_bridgeid(uint64_t id1, uint64_t id2)
{
        u_char addr1[ETHER_ADDR_LEN];
        u_char addr2[ETHER_ADDR_LEN];

        PV2ADDR(id1, addr1);
        PV2ADDR(id2, addr2);

        if (bstp_addr_cmp(addr1, addr2) == 0)
                return (1);

        return (0);
}

void
bstp_reinit(struct bstp_state *bs)
{
        struct epoch_tracker et;
        struct bstp_port *bp;
        struct ifnet *ifp, *mif;
        u_char *e_addr;
        void *bridgeptr;
        static const u_char llzero[ETHER_ADDR_LEN];     /* 00:00:00:00:00:00 */

        BSTP_LOCK_ASSERT(bs);

        if (LIST_EMPTY(&bs->bs_bplist))
                goto disablestp;

        mif = NULL;
        bridgeptr = LIST_FIRST(&bs->bs_bplist)->bp_ifp->if_bridge;
        KASSERT(bridgeptr != NULL, ("Invalid bridge pointer"));
        KASSERT(bridge_same_p != NULL, ("if_bridge not loaded"));
        /*
         * Search through the Ethernet adapters and find the one with the
         * lowest value. Make sure the adapter which we take the MAC address
         * from is part of this bridge, so we can have more than one independent
         * bridges in the same STP domain.
         */
        NET_EPOCH_ENTER(et);
        CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
                if (ifp->if_type != IFT_ETHER && ifp->if_type != IFT_L2VLAN)
                        continue;       /* Not Ethernet */

                if (!bridge_same_p(ifp->if_bridge, bridgeptr))
                        continue;       /* Not part of our bridge */

                if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
                        continue;       /* No mac address set */

                if (mif == NULL) {
                        mif = ifp;
                        continue;
                }
                if (bstp_addr_cmp(IF_LLADDR(ifp), IF_LLADDR(mif)) < 0) {
                        mif = ifp;
                        continue;
                }
        }
        NET_EPOCH_EXIT(et);
        if (mif == NULL)
                goto disablestp;

        e_addr = IF_LLADDR(mif);
        bs->bs_bridge_pv.pv_dbridge_id =
            (((uint64_t)bs->bs_bridge_priority) << 48) |
            (((uint64_t)e_addr[0]) << 40) |
            (((uint64_t)e_addr[1]) << 32) |
            (((uint64_t)e_addr[2]) << 24) |
            (((uint64_t)e_addr[3]) << 16) |
            (((uint64_t)e_addr[4]) << 8) |
            (((uint64_t)e_addr[5]));

        bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
        bs->bs_bridge_pv.pv_cost = 0;
        bs->bs_bridge_pv.pv_dport_id = 0;
        bs->bs_bridge_pv.pv_port_id = 0;

        if (bs->bs_running && callout_pending(&bs->bs_bstpcallout) == 0)
                callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);

        LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                bp->bp_port_id = (bp->bp_priority << 8) |
                    (bp->bp_ifp->if_index  & 0xfff);
                taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
        }

        bstp_assign_roles(bs);
        bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
        return;

disablestp:
        /* Set the bridge and root id (lower bits) to zero */
        bs->bs_bridge_pv.pv_dbridge_id =
            ((uint64_t)bs->bs_bridge_priority) << 48;
        bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
        bs->bs_root_pv = bs->bs_bridge_pv;
        /* Disable any remaining ports, they will have no MAC address */
        LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
                bp->bp_infois = BSTP_INFO_DISABLED;
                bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
        }
        callout_stop(&bs->bs_bstpcallout);
}

static int
bstp_modevent(module_t mod, int type, void *data)
{
        switch (type) {
        case MOD_LOAD:
                mtx_init(&bstp_list_mtx, "bridgestp list", NULL, MTX_DEF);
                break;
        case MOD_UNLOAD:
                mtx_destroy(&bstp_list_mtx);
                break;
        default:
                return (EOPNOTSUPP);
        }
        return (0);
}

static moduledata_t bstp_mod = {
        "bridgestp",
        bstp_modevent,
        0
};

DECLARE_MODULE(bridgestp, bstp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(bridgestp, 1);

void
bstp_attach(struct bstp_state *bs, struct bstp_cb_ops *cb)
{
        BSTP_LOCK_INIT(bs);
        callout_init_mtx(&bs->bs_bstpcallout, &bs->bs_mtx, 0);
        LIST_INIT(&bs->bs_bplist);

        bs->bs_bridge_max_age = BSTP_DEFAULT_MAX_AGE;
        bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
        bs->bs_bridge_fdelay = BSTP_DEFAULT_FORWARD_DELAY;
        bs->bs_bridge_priority = BSTP_DEFAULT_BRIDGE_PRIORITY;
        bs->bs_hold_time = BSTP_DEFAULT_HOLD_TIME;
        bs->bs_migration_delay = BSTP_DEFAULT_MIGRATE_DELAY;
        bs->bs_txholdcount = BSTP_DEFAULT_HOLD_COUNT;
        bs->bs_protover = BSTP_PROTO_RSTP;
        bs->bs_state_cb = cb->bcb_state;
        bs->bs_rtage_cb = cb->bcb_rtage;
        bs->bs_vnet = curvnet;

        getmicrotime(&bs->bs_last_tc_time);

        mtx_lock(&bstp_list_mtx);
        LIST_INSERT_HEAD(&bstp_list, bs, bs_list);
        mtx_unlock(&bstp_list_mtx);
}

void
bstp_detach(struct bstp_state *bs)
{
        KASSERT(LIST_EMPTY(&bs->bs_bplist), ("bstp still active"));

        mtx_lock(&bstp_list_mtx);
        LIST_REMOVE(bs, bs_list);
        mtx_unlock(&bstp_list_mtx);
        callout_drain(&bs->bs_bstpcallout);
        BSTP_LOCK_DESTROY(bs);
}

void
bstp_init(struct bstp_state *bs)
{
        BSTP_LOCK(bs);
        callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
        bs->bs_running = 1;
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
}

void
bstp_stop(struct bstp_state *bs)
{
        struct bstp_port *bp;

        BSTP_LOCK(bs);

        LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
                bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);

        bs->bs_running = 0;
        callout_stop(&bs->bs_bstpcallout);
        BSTP_UNLOCK(bs);
}

int
bstp_create(struct bstp_state *bs, struct bstp_port *bp, struct ifnet *ifp)
{
        bzero(bp, sizeof(struct bstp_port));

        BSTP_LOCK(bs);
        bp->bp_ifp = ifp;
        bp->bp_bs = bs;
        bp->bp_priority = BSTP_DEFAULT_PORT_PRIORITY;
        TASK_INIT(&bp->bp_statetask, 0, bstp_notify_state, bp);
        TASK_INIT(&bp->bp_rtagetask, 0, bstp_notify_rtage, bp);
        TASK_INIT(&bp->bp_mediatask, 0, bstp_ifupdstatus, bp);

        /* Init state */
        bp->bp_infois = BSTP_INFO_DISABLED;
        bp->bp_flags = BSTP_PORT_AUTOEDGE|BSTP_PORT_AUTOPTP;
        bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
        bstp_set_port_proto(bp, bs->bs_protover);
        bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
        bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
        bp->bp_path_cost = bstp_calc_path_cost(bp);
        BSTP_UNLOCK(bs);
        return (0);
}

int
bstp_enable(struct bstp_port *bp)
{
        struct bstp_state *bs = bp->bp_bs;
        struct ifnet *ifp = bp->bp_ifp;

        KASSERT(bp->bp_active == 0, ("already a bstp member"));
        NET_EPOCH_ASSERT(); /* Because bstp_update_roles() causes traffic. */

        switch (ifp->if_type) {
                case IFT_ETHER: /* These can do spanning tree. */
                case IFT_L2VLAN:
                        break;
                default:
                        /* Nothing else can. */
                        return (EINVAL);
        }

        BSTP_LOCK(bs);
        LIST_INSERT_HEAD(&bs->bs_bplist, bp, bp_next);
        bp->bp_active = 1;
        bp->bp_flags |= BSTP_PORT_NEWINFO;
        bstp_reinit(bs);
        bstp_update_roles(bs, bp);
        BSTP_UNLOCK(bs);
        return (0);
}

void
bstp_disable(struct bstp_port *bp)
{
        struct bstp_state *bs = bp->bp_bs;

        KASSERT(bp->bp_active == 1, ("not a bstp member"));

        BSTP_LOCK(bs);
        bstp_disable_port(bs, bp);
        LIST_REMOVE(bp, bp_next);
        bp->bp_active = 0;
        bstp_reinit(bs);
        BSTP_UNLOCK(bs);
}

/*
 * The bstp_port structure is about to be freed by the parent bridge.
 */
void
bstp_destroy(struct bstp_port *bp)
{
        KASSERT(bp->bp_active == 0, ("port is still attached"));
        taskqueue_drain(taskqueue_swi, &bp->bp_statetask);
        taskqueue_drain(taskqueue_swi, &bp->bp_rtagetask);
        taskqueue_drain(taskqueue_swi, &bp->bp_mediatask);

        if (bp->bp_bs->bs_root_port == bp)
                bstp_assign_roles(bp->bp_bs);
}