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bridgestp.c revision 1.4
      1 /*	$NetBSD: bridgestp.c,v 1.4 2003/09/16 17:39:12 jdc Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2000 Jason L. Wright (jason (at) thought.net)
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *      This product includes software developed by Jason L. Wright
     18  * 4. The name of the author may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     24  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     25  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     26  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     27  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     29  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
     30  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  *
     33  * OpenBSD: bridgestp.c,v 1.5 2001/03/22 03:48:29 jason Exp
     34  */
     35 
     36 /*
     37  * Implementation of the spanning tree protocol as defined in
     38  * ISO/IEC Final DIS 15802-3 (IEEE P802.1D/D17), May 25, 1998.
     39  * (In English: IEEE 802.1D, Draft 17, 1998)
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: bridgestp.c,v 1.4 2003/09/16 17:39:12 jdc Exp $");
     44 
     45 #include <sys/param.h>
     46 #include <sys/systm.h>
     47 #include <sys/mbuf.h>
     48 #include <sys/socket.h>
     49 #include <sys/ioctl.h>
     50 #include <sys/device.h>
     51 #include <sys/kernel.h>
     52 #include <sys/callout.h>
     53 
     54 #include <net/if.h>
     55 #include <net/if_dl.h>
     56 #include <net/if_types.h>
     57 #include <net/if_llc.h>
     58 
     59 #include <net/if_ether.h>
     60 #include <net/if_bridgevar.h>
     61 
     62 /* BPDU message types */
     63 #define	BSTP_MSGTYPE_CFG	0x00		/* Configuration */
     64 #define	BSTP_MSGTYPE_TCN	0x80		/* Topology chg notification */
     65 
     66 /* BPDU flags */
     67 #define	BSTP_FLAG_TC		0x01		/* Topology change */
     68 #define	BSTP_FLAG_TCA		0x80		/* Topology change ack */
     69 
     70 #define	BSTP_MESSAGE_AGE_INCR	(1 * 256)	/* in 256ths of a second */
     71 #define	BSTP_TICK_VAL		(1 * 256)	/* in 256ths of a second */
     72 
     73 /*
     74  * Because BPDU's do not make nicely aligned structures, two different
     75  * declarations are used: bstp_?bpdu (wire representation, packed) and
     76  * bstp_*_unit (internal, nicely aligned version).
     77  */
     78 
     79 /* configuration bridge protocol data unit */
     80 struct bstp_cbpdu {
     81 	uint8_t		cbu_dsap;		/* LLC: destination sap */
     82 	uint8_t		cbu_ssap;		/* LLC: source sap */
     83 	uint8_t		cbu_ctl;		/* LLC: control */
     84 	uint16_t	cbu_protoid;		/* protocol id */
     85 	uint8_t		cbu_protover;		/* protocol version */
     86 	uint8_t		cbu_bpdutype;		/* message type */
     87 	uint8_t		cbu_flags;		/* flags (below) */
     88 
     89 	/* root id */
     90 	uint16_t	cbu_rootpri;		/* root priority */
     91 	uint8_t	cbu_rootaddr[6];	/* root address */
     92 
     93 	uint32_t	cbu_rootpathcost;	/* root path cost */
     94 
     95 	/* bridge id */
     96 	uint16_t	cbu_bridgepri;		/* bridge priority */
     97 	uint8_t		cbu_bridgeaddr[6];	/* bridge address */
     98 
     99 	uint16_t	cbu_portid;		/* port id */
    100 	uint16_t	cbu_messageage;		/* current message age */
    101 	uint16_t	cbu_maxage;		/* maximum age */
    102 	uint16_t	cbu_hellotime;		/* hello time */
    103 	uint16_t	cbu_forwarddelay;	/* forwarding delay */
    104 } __attribute__((__packed__));
    105 
    106 /* topology change notification bridge protocol data unit */
    107 struct bstp_tbpdu {
    108 	uint8_t		tbu_dsap;		/* LLC: destination sap */
    109 	uint8_t		tbu_ssap;		/* LLC: source sap */
    110 	uint8_t		tbu_ctl;		/* LLC: control */
    111 	uint16_t	tbu_protoid;		/* protocol id */
    112 	uint8_t		tbu_protover;		/* protocol version */
    113 	uint8_t		tbu_bpdutype;		/* message type */
    114 } __attribute__((__packed__));
    115 
    116 const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
    117 
    118 void	bstp_initialize_port(struct bridge_softc *, struct bridge_iflist *);
    119 void	bstp_ifupdstatus(struct bridge_softc *, struct bridge_iflist *);
    120 void	bstp_enable_port(struct bridge_softc *, struct bridge_iflist *);
    121 void	bstp_disable_port(struct bridge_softc *, struct bridge_iflist *);
    122 void	bstp_enable_change_detection(struct bridge_iflist *);
    123 void	bstp_disable_change_detection(struct bridge_iflist *);
    124 int	bstp_root_bridge(struct bridge_softc *sc);
    125 int	bstp_supersedes_port_info(struct bridge_softc *,
    126 	    struct bridge_iflist *, struct bstp_config_unit *);
    127 int	bstp_designated_port(struct bridge_softc *, struct bridge_iflist *);
    128 int	bstp_designated_for_some_port(struct bridge_softc *);
    129 void	bstp_transmit_config(struct bridge_softc *, struct bridge_iflist *);
    130 void	bstp_transmit_tcn(struct bridge_softc *);
    131 void	bstp_received_config_bpdu(struct bridge_softc *,
    132 	    struct bridge_iflist *, struct bstp_config_unit *);
    133 void	bstp_received_tcn_bpdu(struct bridge_softc *, struct bridge_iflist *,
    134 	    struct bstp_tcn_unit *);
    135 void	bstp_record_config_information(struct bridge_softc *,
    136 	    struct bridge_iflist *, struct bstp_config_unit *);
    137 void	bstp_record_config_timeout_values(struct bridge_softc *,
    138 	    struct bstp_config_unit *);
    139 void	bstp_config_bpdu_generation(struct bridge_softc *);
    140 void	bstp_send_config_bpdu(struct bridge_softc *, struct bridge_iflist *,
    141 	    struct bstp_config_unit *);
    142 void	bstp_configuration_update(struct bridge_softc *);
    143 void	bstp_root_selection(struct bridge_softc *);
    144 void	bstp_designated_port_selection(struct bridge_softc *);
    145 void	bstp_become_designated_port(struct bridge_softc *,
    146 	    struct bridge_iflist *);
    147 void	bstp_port_state_selection(struct bridge_softc *);
    148 void	bstp_make_forwarding(struct bridge_softc *, struct bridge_iflist *);
    149 void	bstp_make_blocking(struct bridge_softc *, struct bridge_iflist *);
    150 void	bstp_set_port_state(struct bridge_iflist *, uint8_t);
    151 void	bstp_set_bridge_priority(struct bridge_softc *, uint64_t);
    152 void	bstp_set_port_priority(struct bridge_softc *, struct bridge_iflist *,
    153 	    uint16_t);
    154 void	bstp_set_path_cost(struct bridge_softc *, struct bridge_iflist *,
    155 	    uint32_t);
    156 void	bstp_topology_change_detection(struct bridge_softc *);
    157 void	bstp_topology_change_acknowledged(struct bridge_softc *);
    158 void	bstp_acknowledge_topology_change(struct bridge_softc *,
    159 	    struct bridge_iflist *);
    160 
    161 void	bstp_tick(void *);
    162 void	bstp_timer_start(struct bridge_timer *, uint16_t);
    163 void	bstp_timer_stop(struct bridge_timer *);
    164 int	bstp_timer_expired(struct bridge_timer *, uint16_t);
    165 
    166 void	bstp_hold_timer_expiry(struct bridge_softc *, struct bridge_iflist *);
    167 void	bstp_message_age_timer_expiry(struct bridge_softc *,
    168 	    struct bridge_iflist *);
    169 void	bstp_forward_delay_timer_expiry(struct bridge_softc *,
    170 	    struct bridge_iflist *);
    171 void	bstp_topology_change_timer_expiry(struct bridge_softc *);
    172 void	bstp_tcn_timer_expiry(struct bridge_softc *);
    173 void	bstp_hello_timer_expiry(struct bridge_softc *);
    174 
    175 void
    176 bstp_transmit_config(struct bridge_softc *sc, struct bridge_iflist *bif)
    177 {
    178 	if (bif->bif_hold_timer.active) {
    179 		bif->bif_config_pending = 1;
    180 		return;
    181 	}
    182 
    183 	bif->bif_config_bpdu.cu_message_type = BSTP_MSGTYPE_CFG;
    184 	bif->bif_config_bpdu.cu_rootid = sc->sc_designated_root;
    185 	bif->bif_config_bpdu.cu_root_path_cost = sc->sc_root_path_cost;
    186 	bif->bif_config_bpdu.cu_bridge_id = sc->sc_bridge_id;
    187 	bif->bif_config_bpdu.cu_port_id = bif->bif_port_id;
    188 
    189 	if (bstp_root_bridge(sc))
    190 		bif->bif_config_bpdu.cu_message_age = 0;
    191 	else
    192 		bif->bif_config_bpdu.cu_message_age =
    193 		    sc->sc_root_port->bif_message_age_timer.value +
    194 		    BSTP_MESSAGE_AGE_INCR;
    195 
    196 	bif->bif_config_bpdu.cu_max_age = sc->sc_max_age;
    197 	bif->bif_config_bpdu.cu_hello_time = sc->sc_hello_time;
    198 	bif->bif_config_bpdu.cu_forward_delay = sc->sc_forward_delay;
    199 	bif->bif_config_bpdu.cu_topology_change_acknowledgment
    200 	    = bif->bif_topology_change_acknowledge;
    201 	bif->bif_config_bpdu.cu_topology_change = sc->sc_topology_change;
    202 
    203 	if (bif->bif_config_bpdu.cu_message_age < sc->sc_max_age) {
    204 		bif->bif_topology_change_acknowledge = 0;
    205 		bif->bif_config_pending = 0;
    206 		bstp_send_config_bpdu(sc, bif, &bif->bif_config_bpdu);
    207 		bstp_timer_start(&bif->bif_hold_timer, 0);
    208 	}
    209 }
    210 
    211 void
    212 bstp_send_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
    213     struct bstp_config_unit *cu)
    214 {
    215 	struct ifnet *ifp;
    216 	struct mbuf *m;
    217 	struct ether_header *eh;
    218 	struct bstp_cbpdu bpdu;
    219 	int s;
    220 
    221 	ifp = bif->bif_ifp;
    222 
    223 	if ((ifp->if_flags & IFF_RUNNING) == 0)
    224 		return;
    225 
    226 	MGETHDR(m, M_DONTWAIT, MT_DATA);
    227 	if (m == NULL)
    228 		return;
    229 
    230 	eh = mtod(m, struct ether_header *);
    231 
    232 	m->m_pkthdr.rcvif = ifp;
    233 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
    234 	m->m_len = m->m_pkthdr.len;
    235 
    236 	bpdu.cbu_ssap = bpdu.cbu_dsap = LLC_8021D_LSAP;
    237 	bpdu.cbu_ctl = LLC_UI;
    238 	bpdu.cbu_protoid = htons(0);
    239 	bpdu.cbu_protover = 0;
    240 	bpdu.cbu_bpdutype = cu->cu_message_type;
    241 	bpdu.cbu_flags = (cu->cu_topology_change ? BSTP_FLAG_TC : 0) |
    242 	    (cu->cu_topology_change_acknowledgment ? BSTP_FLAG_TCA : 0);
    243 
    244 	bpdu.cbu_rootpri = htons(cu->cu_rootid >> 48);
    245 	bpdu.cbu_rootaddr[0] = cu->cu_rootid >> 40;
    246 	bpdu.cbu_rootaddr[1] = cu->cu_rootid >> 32;
    247 	bpdu.cbu_rootaddr[2] = cu->cu_rootid >> 24;
    248 	bpdu.cbu_rootaddr[3] = cu->cu_rootid >> 16;
    249 	bpdu.cbu_rootaddr[4] = cu->cu_rootid >> 8;
    250 	bpdu.cbu_rootaddr[5] = cu->cu_rootid >> 0;
    251 
    252 	bpdu.cbu_rootpathcost = htonl(cu->cu_root_path_cost);
    253 
    254 	bpdu.cbu_bridgepri = htons(cu->cu_rootid >> 48);
    255 	bpdu.cbu_bridgeaddr[0] = cu->cu_rootid >> 40;
    256 	bpdu.cbu_bridgeaddr[1] = cu->cu_rootid >> 32;
    257 	bpdu.cbu_bridgeaddr[2] = cu->cu_rootid >> 24;
    258 	bpdu.cbu_bridgeaddr[3] = cu->cu_rootid >> 16;
    259 	bpdu.cbu_bridgeaddr[4] = cu->cu_rootid >> 8;
    260 	bpdu.cbu_bridgeaddr[5] = cu->cu_rootid >> 0;
    261 
    262 	bpdu.cbu_portid = htons(cu->cu_port_id);
    263 	bpdu.cbu_messageage = htons(cu->cu_message_age);
    264 	bpdu.cbu_maxage = htons(cu->cu_max_age);
    265 	bpdu.cbu_hellotime = htons(cu->cu_hello_time);
    266 	bpdu.cbu_forwarddelay = htons(cu->cu_forward_delay);
    267 
    268 	memcpy(eh->ether_shost, LLADDR(ifp->if_sadl), ETHER_ADDR_LEN);
    269 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
    270 	eh->ether_type = htons(sizeof(bpdu));
    271 
    272 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
    273 
    274 	s = splnet();
    275 	bridge_enqueue(sc, ifp, m, 0);
    276 	splx(s);
    277 }
    278 
    279 int
    280 bstp_root_bridge(struct bridge_softc *sc)
    281 {
    282 	return (sc->sc_designated_root == sc->sc_bridge_id);
    283 }
    284 
    285 int
    286 bstp_supersedes_port_info(struct bridge_softc *sc, struct bridge_iflist *bif,
    287     struct bstp_config_unit *cu)
    288 {
    289 	if (cu->cu_rootid < bif->bif_designated_root)
    290 		return (1);
    291 	if (cu->cu_rootid > bif->bif_designated_root)
    292 		return (0);
    293 
    294 	if (cu->cu_root_path_cost < bif->bif_designated_cost)
    295 		return (1);
    296 	if (cu->cu_root_path_cost > bif->bif_designated_cost)
    297 		return (0);
    298 
    299 	if (cu->cu_bridge_id < bif->bif_designated_bridge)
    300 		return (1);
    301 	if (cu->cu_bridge_id > bif->bif_designated_bridge)
    302 		return (0);
    303 
    304 	if (sc->sc_bridge_id != cu->cu_bridge_id)
    305 		return (1);
    306 	if (cu->cu_port_id <= bif->bif_designated_port)
    307 		return (1);
    308 	return (0);
    309 }
    310 
    311 void
    312 bstp_record_config_information(struct bridge_softc *sc,
    313     struct bridge_iflist *bif, struct bstp_config_unit *cu)
    314 {
    315 	bif->bif_designated_root = cu->cu_rootid;
    316 	bif->bif_designated_cost = cu->cu_root_path_cost;
    317 	bif->bif_designated_bridge = cu->cu_bridge_id;
    318 	bif->bif_designated_port = cu->cu_port_id;
    319 	bstp_timer_start(&bif->bif_message_age_timer, cu->cu_message_age);
    320 }
    321 
    322 void
    323 bstp_record_config_timeout_values(struct bridge_softc *sc,
    324     struct bstp_config_unit *config)
    325 {
    326 	sc->sc_max_age = config->cu_max_age;
    327 	sc->sc_hello_time = config->cu_hello_time;
    328 	sc->sc_forward_delay = config->cu_forward_delay;
    329 	sc->sc_topology_change = config->cu_topology_change;
    330 }
    331 
    332 void
    333 bstp_config_bpdu_generation(struct bridge_softc *sc)
    334 {
    335 	struct bridge_iflist *bif;
    336 
    337 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    338 		if ((bif->bif_flags & IFBIF_STP) == 0)
    339 			continue;
    340 		if (bstp_designated_port(sc, bif) &&
    341 		    (bif->bif_state != BSTP_IFSTATE_DISABLED))
    342 			bstp_transmit_config(sc, bif);
    343 	}
    344 }
    345 
    346 int
    347 bstp_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    348 {
    349 	return ((bif->bif_designated_bridge == sc->sc_bridge_id)
    350 	    && (bif->bif_designated_port == bif->bif_port_id));
    351 }
    352 
    353 void
    354 bstp_transmit_tcn(struct bridge_softc *sc)
    355 {
    356 	struct bstp_tbpdu bpdu;
    357 	struct bridge_iflist *bif = sc->sc_root_port;
    358 	struct ifnet *ifp = bif->bif_ifp;
    359 	struct ether_header *eh;
    360 	struct mbuf *m;
    361 	int s;
    362 
    363 	if ((ifp->if_flags & IFF_RUNNING) == 0)
    364 		return;
    365 
    366 	MGETHDR(m, M_DONTWAIT, MT_DATA);
    367 	if (m == NULL)
    368 		return;
    369 
    370 	m->m_pkthdr.rcvif = ifp;
    371 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
    372 	m->m_len = m->m_pkthdr.len;
    373 
    374 	eh = mtod(m, struct ether_header *);
    375 
    376 	memcpy(eh->ether_shost, LLADDR(ifp->if_sadl), ETHER_ADDR_LEN);
    377 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
    378 	eh->ether_type = htons(sizeof(bpdu));
    379 
    380 	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
    381 	bpdu.tbu_ctl = LLC_UI;
    382 	bpdu.tbu_protoid = 0;
    383 	bpdu.tbu_protover = 0;
    384 	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
    385 
    386 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
    387 
    388 	s = splnet();
    389 	bridge_enqueue(sc, ifp, m, 0);
    390 	splx(s);
    391 }
    392 
    393 void
    394 bstp_configuration_update(struct bridge_softc *sc)
    395 {
    396 	bstp_root_selection(sc);
    397 	bstp_designated_port_selection(sc);
    398 }
    399 
    400 void
    401 bstp_root_selection(struct bridge_softc *sc)
    402 {
    403 	struct bridge_iflist *root_port = NULL, *bif;
    404 
    405 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    406 		if ((bif->bif_flags & IFBIF_STP) == 0)
    407 			continue;
    408 		if (bstp_designated_port(sc, bif))
    409 			continue;
    410 		if (bif->bif_state == BSTP_IFSTATE_DISABLED)
    411 			continue;
    412 		if (bif->bif_designated_root >= sc->sc_bridge_id)
    413 			continue;
    414 		if (root_port == NULL)
    415 			goto set_port;
    416 
    417 		if (bif->bif_designated_root < root_port->bif_designated_root)
    418 			goto set_port;
    419 		if (bif->bif_designated_root > root_port->bif_designated_root)
    420 			continue;
    421 
    422 		if ((bif->bif_designated_cost + bif->bif_path_cost) <
    423 		    (root_port->bif_designated_cost + root_port->bif_path_cost))
    424 			goto set_port;
    425 		if ((bif->bif_designated_cost + bif->bif_path_cost) >
    426 		    (root_port->bif_designated_cost + root_port->bif_path_cost))
    427 			continue;
    428 
    429 		if (bif->bif_designated_bridge <
    430 		    root_port->bif_designated_bridge)
    431 			goto set_port;
    432 		if (bif->bif_designated_bridge >
    433 		    root_port->bif_designated_bridge)
    434 			continue;
    435 
    436 		if (bif->bif_designated_port < root_port->bif_designated_port)
    437 			goto set_port;
    438 		if (bif->bif_designated_port > root_port->bif_designated_port)
    439 			continue;
    440 
    441 		if (bif->bif_port_id >= root_port->bif_port_id)
    442 			continue;
    443 set_port:
    444 		root_port = bif;
    445 	}
    446 
    447 	sc->sc_root_port = root_port;
    448 	if (root_port == NULL) {
    449 		sc->sc_designated_root = sc->sc_bridge_id;
    450 		sc->sc_root_path_cost = 0;
    451 	} else {
    452 		sc->sc_designated_root = root_port->bif_designated_root;
    453 		sc->sc_root_path_cost = root_port->bif_designated_cost +
    454 		    root_port->bif_path_cost;
    455 	}
    456 }
    457 
    458 void
    459 bstp_designated_port_selection(struct bridge_softc *sc)
    460 {
    461 	struct bridge_iflist *bif;
    462 
    463 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    464 		if ((bif->bif_flags & IFBIF_STP) == 0)
    465 			continue;
    466 		if (bstp_designated_port(sc, bif))
    467 			goto designated;
    468 		if (bif->bif_designated_root != sc->sc_designated_root)
    469 			goto designated;
    470 
    471 		if (sc->sc_root_path_cost < bif->bif_designated_cost)
    472 			goto designated;
    473 		if (sc->sc_root_path_cost > bif->bif_designated_cost)
    474 			continue;
    475 
    476 		if (sc->sc_bridge_id < bif->bif_designated_bridge)
    477 			goto designated;
    478 		if (sc->sc_bridge_id > bif->bif_designated_bridge)
    479 			continue;
    480 
    481 		if (bif->bif_port_id > bif->bif_designated_port)
    482 			continue;
    483 designated:
    484 		bstp_become_designated_port(sc, bif);
    485 	}
    486 }
    487 
    488 void
    489 bstp_become_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    490 {
    491 	bif->bif_designated_root = sc->sc_designated_root;
    492 	bif->bif_designated_cost = sc->sc_root_path_cost;
    493 	bif->bif_designated_bridge = sc->sc_bridge_id;
    494 	bif->bif_designated_port = bif->bif_port_id;
    495 }
    496 
    497 void
    498 bstp_port_state_selection(struct bridge_softc *sc)
    499 {
    500 	struct bridge_iflist *bif;
    501 
    502 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    503 		if ((bif->bif_flags & IFBIF_STP) == 0)
    504 			continue;
    505 		if (bif == sc->sc_root_port) {
    506 			bif->bif_config_pending = 0;
    507 			bif->bif_topology_change_acknowledge = 0;
    508 			bstp_make_forwarding(sc, bif);
    509 		} else if (bstp_designated_port(sc, bif)) {
    510 			bstp_timer_stop(&bif->bif_message_age_timer);
    511 			bstp_make_forwarding(sc, bif);
    512 		} else {
    513 			bif->bif_config_pending = 0;
    514 			bif->bif_topology_change_acknowledge = 0;
    515 			bstp_make_blocking(sc, bif);
    516 		}
    517 	}
    518 }
    519 
    520 void
    521 bstp_make_forwarding(struct bridge_softc *sc, struct bridge_iflist *bif)
    522 {
    523 	if (bif->bif_state == BSTP_IFSTATE_BLOCKING) {
    524 		bstp_set_port_state(bif, BSTP_IFSTATE_LISTENING);
    525 		bstp_timer_start(&bif->bif_forward_delay_timer, 0);
    526 	}
    527 }
    528 
    529 void
    530 bstp_make_blocking(struct bridge_softc *sc, struct bridge_iflist *bif)
    531 {
    532 	if ((bif->bif_state != BSTP_IFSTATE_DISABLED) &&
    533 	    (bif->bif_state != BSTP_IFSTATE_BLOCKING)) {
    534 		if ((bif->bif_state == BSTP_IFSTATE_FORWARDING) ||
    535 		    (bif->bif_state == BSTP_IFSTATE_LEARNING)) {
    536 			if (bif->bif_change_detection_enabled) {
    537 				bstp_topology_change_detection(sc);
    538 			}
    539 		}
    540 		bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
    541 		bstp_timer_stop(&bif->bif_forward_delay_timer);
    542 	}
    543 }
    544 
    545 void
    546 bstp_set_port_state(struct bridge_iflist *bif, uint8_t state)
    547 {
    548 	bif->bif_state = state;
    549 }
    550 
    551 void
    552 bstp_topology_change_detection(struct bridge_softc *sc)
    553 {
    554 	if (bstp_root_bridge(sc)) {
    555 		sc->sc_topology_change = 1;
    556 		bstp_timer_start(&sc->sc_topology_change_timer, 0);
    557 	} else if (!sc->sc_topology_change_detected) {
    558 		bstp_transmit_tcn(sc);
    559 		bstp_timer_start(&sc->sc_tcn_timer, 0);
    560 	}
    561 	sc->sc_topology_change_detected = 1;
    562 }
    563 
    564 void
    565 bstp_topology_change_acknowledged(struct bridge_softc *sc)
    566 {
    567 	sc->sc_topology_change_detected = 0;
    568 	bstp_timer_stop(&sc->sc_tcn_timer);
    569 }
    570 
    571 void
    572 bstp_acknowledge_topology_change(struct bridge_softc *sc,
    573     struct bridge_iflist *bif)
    574 {
    575 	bif->bif_topology_change_acknowledge = 1;
    576 	bstp_transmit_config(sc, bif);
    577 }
    578 
    579 struct mbuf *
    580 bstp_input(struct ifnet *ifp, struct mbuf *m)
    581 {
    582 	struct bridge_softc *sc = ifp->if_bridge;
    583 	struct bridge_iflist *bif = NULL;
    584 	struct ether_header *eh;
    585 	struct bstp_tbpdu tpdu;
    586 	struct bstp_cbpdu cpdu;
    587 	struct bstp_config_unit cu;
    588 	struct bstp_tcn_unit tu;
    589 	uint16_t len;
    590 
    591 	eh = mtod(m, struct ether_header *);
    592 
    593 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    594 		if ((bif->bif_flags & IFBIF_STP) == 0)
    595 			continue;
    596 		if (bif->bif_ifp == ifp)
    597 			break;
    598 	}
    599 	if (bif == NULL)
    600 		goto out;
    601 
    602 	len = ntohs(eh->ether_type);
    603 	if (len < sizeof(tpdu))
    604 		goto out;
    605 
    606 	m_adj(m, ETHER_HDR_LEN);
    607 
    608 	if (m->m_pkthdr.len > len)
    609 		m_adj(m, len - m->m_pkthdr.len);
    610 	if (m->m_len < sizeof(tpdu) &&
    611 	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
    612 		goto out;
    613 
    614 	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
    615 
    616 	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
    617 	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
    618 	    tpdu.tbu_ctl != LLC_UI)
    619 		goto out;
    620 	if (tpdu.tbu_protoid != 0 || tpdu.tbu_protover != 0)
    621 		goto out;
    622 
    623 	switch (tpdu.tbu_bpdutype) {
    624 	case BSTP_MSGTYPE_TCN:
    625 		tu.tu_message_type = tpdu.tbu_bpdutype;
    626 		bstp_received_tcn_bpdu(sc, bif, &tu);
    627 		break;
    628 	case BSTP_MSGTYPE_CFG:
    629 		if (m->m_len < sizeof(cpdu) &&
    630 		    (m = m_pullup(m, sizeof(cpdu))) == NULL)
    631 			goto out;
    632 		memcpy(&cpdu, mtod(m, caddr_t), sizeof(cpdu));
    633 
    634 		cu.cu_rootid =
    635 		    (((uint64_t)ntohs(cpdu.cbu_rootpri)) << 48) |
    636 		    (((uint64_t)cpdu.cbu_rootaddr[0]) << 40) |
    637 		    (((uint64_t)cpdu.cbu_rootaddr[1]) << 32) |
    638 		    (((uint64_t)cpdu.cbu_rootaddr[2]) << 24) |
    639 		    (((uint64_t)cpdu.cbu_rootaddr[3]) << 16) |
    640 		    (((uint64_t)cpdu.cbu_rootaddr[4]) << 8) |
    641 		    (((uint64_t)cpdu.cbu_rootaddr[5]) << 0);
    642 
    643 		cu.cu_bridge_id =
    644 		    (((uint64_t)ntohs(cpdu.cbu_bridgepri)) << 48) |
    645 		    (((uint64_t)cpdu.cbu_bridgeaddr[0]) << 40) |
    646 		    (((uint64_t)cpdu.cbu_bridgeaddr[1]) << 32) |
    647 		    (((uint64_t)cpdu.cbu_bridgeaddr[2]) << 24) |
    648 		    (((uint64_t)cpdu.cbu_bridgeaddr[3]) << 16) |
    649 		    (((uint64_t)cpdu.cbu_bridgeaddr[4]) << 8) |
    650 		    (((uint64_t)cpdu.cbu_bridgeaddr[5]) << 0);
    651 
    652 		cu.cu_root_path_cost = ntohl(cpdu.cbu_rootpathcost);
    653 		cu.cu_message_age = ntohs(cpdu.cbu_messageage);
    654 		cu.cu_max_age = ntohs(cpdu.cbu_maxage);
    655 		cu.cu_hello_time = ntohs(cpdu.cbu_hellotime);
    656 		cu.cu_forward_delay = ntohs(cpdu.cbu_forwarddelay);
    657 		cu.cu_port_id = ntohs(cpdu.cbu_portid);
    658 		cu.cu_message_type = cpdu.cbu_bpdutype;
    659 		cu.cu_topology_change_acknowledgment =
    660 		    (cpdu.cbu_flags & BSTP_FLAG_TCA) ? 1 : 0;
    661 		cu.cu_topology_change =
    662 		    (cpdu.cbu_flags & BSTP_FLAG_TC) ? 1 : 0;
    663 		bstp_received_config_bpdu(sc, bif, &cu);
    664 		break;
    665 	default:
    666 		goto out;
    667 	}
    668 
    669  out:
    670 	if (m)
    671 		m_freem(m);
    672 	return (NULL);
    673 }
    674 
    675 void
    676 bstp_received_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
    677     struct bstp_config_unit *cu)
    678 {
    679 	int root;
    680 
    681 	root = bstp_root_bridge(sc);
    682 
    683 	if (bif->bif_state != BSTP_IFSTATE_DISABLED) {
    684 		if (bstp_supersedes_port_info(sc, bif, cu)) {
    685 			bstp_record_config_information(sc, bif, cu);
    686 			bstp_configuration_update(sc);
    687 			bstp_port_state_selection(sc);
    688 
    689 			if ((bstp_root_bridge(sc) == 0) && root) {
    690 				bstp_timer_stop(&sc->sc_hello_timer);
    691 
    692 				if (sc->sc_topology_change_detected) {
    693 					bstp_timer_stop(
    694 					    &sc->sc_topology_change_timer);
    695 					bstp_transmit_tcn(sc);
    696 					bstp_timer_start(&sc->sc_tcn_timer, 0);
    697 				}
    698 			}
    699 
    700 			if (bif == sc->sc_root_port) {
    701 				bstp_record_config_timeout_values(sc, cu);
    702 				bstp_config_bpdu_generation(sc);
    703 
    704 				if (cu->cu_topology_change_acknowledgment)
    705 					bstp_topology_change_acknowledged(sc);
    706 			}
    707 		} else if (bstp_designated_port(sc, bif))
    708 			bstp_transmit_config(sc, bif);
    709 	}
    710 }
    711 
    712 void
    713 bstp_received_tcn_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
    714     struct bstp_tcn_unit *tcn)
    715 {
    716 	if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
    717 	    bstp_designated_port(sc, bif)) {
    718 		bstp_topology_change_detection(sc);
    719 		bstp_acknowledge_topology_change(sc, bif);
    720 	}
    721 }
    722 
    723 void
    724 bstp_hello_timer_expiry(struct bridge_softc *sc)
    725 {
    726 	bstp_config_bpdu_generation(sc);
    727 	bstp_timer_start(&sc->sc_hello_timer, 0);
    728 }
    729 
    730 void
    731 bstp_message_age_timer_expiry(struct bridge_softc *sc,
    732     struct bridge_iflist *bif)
    733 {
    734 	int root;
    735 
    736 	root = bstp_root_bridge(sc);
    737 	bstp_become_designated_port(sc, bif);
    738 	bstp_configuration_update(sc);
    739 	bstp_port_state_selection(sc);
    740 
    741 	if ((bstp_root_bridge(sc)) && (root == 0)) {
    742 		sc->sc_max_age = sc->sc_bridge_max_age;
    743 		sc->sc_hello_time = sc->sc_bridge_hello_time;
    744 		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    745 
    746 		bstp_topology_change_detection(sc);
    747 		bstp_timer_stop(&sc->sc_tcn_timer);
    748 		bstp_config_bpdu_generation(sc);
    749 		bstp_timer_start(&sc->sc_hello_timer, 0);
    750 	}
    751 }
    752 
    753 void
    754 bstp_forward_delay_timer_expiry(struct bridge_softc *sc,
    755     struct bridge_iflist *bif)
    756 {
    757 	if (bif->bif_state == BSTP_IFSTATE_LISTENING) {
    758 		bstp_set_port_state(bif, BSTP_IFSTATE_LEARNING);
    759 		bstp_timer_start(&bif->bif_forward_delay_timer, 0);
    760 	} else if (bif->bif_state == BSTP_IFSTATE_LEARNING) {
    761 		bstp_set_port_state(bif, BSTP_IFSTATE_FORWARDING);
    762 		if (bstp_designated_for_some_port(sc) &&
    763 		    bif->bif_change_detection_enabled)
    764 			bstp_topology_change_detection(sc);
    765 	}
    766 }
    767 
    768 int
    769 bstp_designated_for_some_port(struct bridge_softc *sc)
    770 {
    771 
    772 	struct bridge_iflist *bif;
    773 
    774 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    775 		if ((bif->bif_flags & IFBIF_STP) == 0)
    776 			continue;
    777 		if (bif->bif_designated_bridge == sc->sc_bridge_id)
    778 			return (1);
    779 	}
    780 	return (0);
    781 }
    782 
    783 void
    784 bstp_tcn_timer_expiry(struct bridge_softc *sc)
    785 {
    786 	bstp_transmit_tcn(sc);
    787 	bstp_timer_start(&sc->sc_tcn_timer, 0);
    788 }
    789 
    790 void
    791 bstp_topology_change_timer_expiry(struct bridge_softc *sc)
    792 {
    793 	sc->sc_topology_change_detected = 0;
    794 	sc->sc_topology_change = 0;
    795 }
    796 
    797 void
    798 bstp_hold_timer_expiry(struct bridge_softc *sc, struct bridge_iflist *bif)
    799 {
    800 	if (bif->bif_config_pending)
    801 		bstp_transmit_config(sc, bif);
    802 }
    803 
    804 void
    805 bstp_initialization(struct bridge_softc *sc)
    806 {
    807 	struct bridge_iflist *bif, *mif;
    808 
    809 	mif = NULL;
    810 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    811 		if ((bif->bif_flags & IFBIF_STP) == 0)
    812 			continue;
    813 		if (bif->bif_ifp->if_type != IFT_ETHER)
    814 			continue;
    815 		bif->bif_port_id = (bif->bif_priority << 8) |
    816 		    (bif->bif_ifp->if_index & 0xff);
    817 
    818 		if (mif == NULL) {
    819 			mif = bif;
    820 			continue;
    821 		}
    822 		if (memcmp(LLADDR(bif->bif_ifp->if_sadl),
    823 		    LLADDR(mif->bif_ifp->if_sadl), ETHER_ADDR_LEN) < 0) {
    824 			mif = bif;
    825 			continue;
    826 		}
    827 	}
    828 	if (mif == NULL) {
    829 		bstp_stop(sc);
    830 		return;
    831 	}
    832 
    833 	sc->sc_bridge_id =
    834 	    (((uint64_t)sc->sc_bridge_priority) << 48) |
    835 	    (((uint64_t)LLADDR(mif->bif_ifp->if_sadl)[0]) << 40) |
    836 	    (((uint64_t)LLADDR(mif->bif_ifp->if_sadl)[1]) << 32) |
    837 	    (LLADDR(mif->bif_ifp->if_sadl)[2] << 24) |
    838 	    (LLADDR(mif->bif_ifp->if_sadl)[3] << 16) |
    839 	    (LLADDR(mif->bif_ifp->if_sadl)[4] << 8) |
    840 	    (LLADDR(mif->bif_ifp->if_sadl)[5]);
    841 
    842 	sc->sc_designated_root = sc->sc_bridge_id;
    843 	sc->sc_root_path_cost = 0;
    844 	sc->sc_root_port = NULL;
    845 
    846 	sc->sc_max_age = sc->sc_bridge_max_age;
    847 	sc->sc_hello_time = sc->sc_bridge_hello_time;
    848 	sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    849 	sc->sc_topology_change_detected = 0;
    850 	sc->sc_topology_change = 0;
    851 	bstp_timer_stop(&sc->sc_tcn_timer);
    852 	bstp_timer_stop(&sc->sc_topology_change_timer);
    853 
    854 	if (callout_pending(&sc->sc_bstpcallout) == 0)
    855 		callout_reset(&sc->sc_bstpcallout, hz,
    856 		    bstp_tick, sc);
    857 
    858 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    859 		if (bif->bif_flags & IFBIF_STP)
    860 			bstp_enable_port(sc, bif);
    861 		else
    862 			bstp_disable_port(sc, bif);
    863 	}
    864 
    865 	bstp_port_state_selection(sc);
    866 	bstp_config_bpdu_generation(sc);
    867 	bstp_timer_start(&sc->sc_hello_timer, 0);
    868 }
    869 
    870 void
    871 bstp_stop(struct bridge_softc *sc)
    872 {
    873 	struct bridge_iflist *bif;
    874 
    875 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    876 		bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
    877 		bstp_timer_stop(&bif->bif_hold_timer);
    878 		bstp_timer_stop(&bif->bif_message_age_timer);
    879 		bstp_timer_stop(&bif->bif_forward_delay_timer);
    880 	}
    881 
    882 	callout_stop(&sc->sc_bstpcallout);
    883 
    884 	bstp_timer_stop(&sc->sc_topology_change_timer);
    885 	bstp_timer_stop(&sc->sc_tcn_timer);
    886 	bstp_timer_stop(&sc->sc_hello_timer);
    887 
    888 }
    889 
    890 void
    891 bstp_initialize_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    892 {
    893 	bstp_become_designated_port(sc, bif);
    894 	bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
    895 	bif->bif_topology_change_acknowledge = 0;
    896 	bif->bif_config_pending = 0;
    897 	bif->bif_change_detection_enabled = 1;
    898 	bstp_timer_stop(&bif->bif_message_age_timer);
    899 	bstp_timer_stop(&bif->bif_forward_delay_timer);
    900 	bstp_timer_stop(&bif->bif_hold_timer);
    901 }
    902 
    903 void
    904 bstp_enable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    905 {
    906 	bstp_initialize_port(sc, bif);
    907 	bstp_port_state_selection(sc);
    908 }
    909 
    910 void
    911 bstp_disable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    912 {
    913 	int root;
    914 
    915 	root = bstp_root_bridge(sc);
    916 	bstp_become_designated_port(sc, bif);
    917 	bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
    918 	bif->bif_topology_change_acknowledge = 0;
    919 	bif->bif_config_pending = 0;
    920 	bstp_timer_stop(&bif->bif_message_age_timer);
    921 	bstp_timer_stop(&bif->bif_forward_delay_timer);
    922 	bstp_configuration_update(sc);
    923 	bstp_port_state_selection(sc);
    924 
    925 	if (bstp_root_bridge(sc) && (root == 0)) {
    926 		sc->sc_max_age = sc->sc_bridge_max_age;
    927 		sc->sc_hello_time = sc->sc_bridge_hello_time;
    928 		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    929 
    930 		bstp_topology_change_detection(sc);
    931 		bstp_timer_stop(&sc->sc_tcn_timer);
    932 		bstp_config_bpdu_generation(sc);
    933 		bstp_timer_start(&sc->sc_hello_timer, 0);
    934 	}
    935 }
    936 
    937 void
    938 bstp_set_bridge_priority(struct bridge_softc *sc, uint64_t new_bridge_id)
    939 {
    940 	struct bridge_iflist *bif;
    941 	int root;
    942 
    943 	root = bstp_root_bridge(sc);
    944 
    945 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    946 		if ((bif->bif_flags & IFBIF_STP) == 0)
    947 			continue;
    948 		if (bstp_designated_port(sc, bif))
    949 			bif->bif_designated_bridge = new_bridge_id;
    950 	}
    951 
    952 	sc->sc_bridge_id = new_bridge_id;
    953 
    954 	bstp_configuration_update(sc);
    955 	bstp_port_state_selection(sc);
    956 
    957 	if (bstp_root_bridge(sc) && (root == 0)) {
    958 		sc->sc_max_age = sc->sc_bridge_max_age;
    959 		sc->sc_hello_time = sc->sc_bridge_hello_time;
    960 		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    961 
    962 		bstp_topology_change_detection(sc);
    963 		bstp_timer_stop(&sc->sc_tcn_timer);
    964 		bstp_config_bpdu_generation(sc);
    965 		bstp_timer_start(&sc->sc_hello_timer, 0);
    966 	}
    967 }
    968 
    969 void
    970 bstp_set_port_priority(struct bridge_softc *sc, struct bridge_iflist *bif,
    971     uint16_t new_port_id)
    972 {
    973 	if (bstp_designated_port(sc, bif))
    974 		bif->bif_designated_port = new_port_id;
    975 
    976 	bif->bif_port_id = new_port_id;
    977 
    978 	if ((sc->sc_bridge_id == bif->bif_designated_bridge) &&
    979 	    (bif->bif_port_id < bif->bif_designated_port)) {
    980 		bstp_become_designated_port(sc, bif);
    981 		bstp_port_state_selection(sc);
    982 	}
    983 }
    984 
    985 void
    986 bstp_set_path_cost(struct bridge_softc *sc, struct bridge_iflist *bif,
    987     uint32_t path_cost)
    988 {
    989 	bif->bif_path_cost = path_cost;
    990 	bstp_configuration_update(sc);
    991 	bstp_port_state_selection(sc);
    992 }
    993 
    994 void
    995 bstp_enable_change_detection(struct bridge_iflist *bif)
    996 {
    997 	bif->bif_change_detection_enabled = 1;
    998 }
    999 
   1000 void
   1001 bstp_disable_change_detection(struct bridge_iflist *bif)
   1002 {
   1003 	bif->bif_change_detection_enabled = 0;
   1004 }
   1005 
   1006 void
   1007 bstp_ifupdstatus(struct bridge_softc *sc, struct bridge_iflist *bif)
   1008 {
   1009 	struct ifnet *ifp = bif->bif_ifp;
   1010 
   1011 	if (ifp->if_flags & IFF_UP) {
   1012 	 	switch (ifp->if_link_state) {
   1013 		case LINK_STATE_UNKNOWN:
   1014 			/*
   1015 			 * Just enable the port if the link state is
   1016 			 * unknown.
   1017 			 */
   1018 			if (bif->bif_state == BSTP_IFSTATE_DISABLED)
   1019 				bstp_enable_port(sc, bif);
   1020 			break;
   1021 
   1022 		case LINK_STATE_UP:
   1023 			if (bif->bif_state == BSTP_IFSTATE_DISABLED)
   1024 				bstp_enable_port(sc, bif);
   1025 			break;
   1026 
   1027 		case LINK_STATE_DOWN:
   1028 			if (bif->bif_state != BSTP_IFSTATE_DISABLED)
   1029 				bstp_disable_port(sc, bif);
   1030 			break;
   1031 		}
   1032 		return;
   1033 	}
   1034 
   1035 	if (bif->bif_state != BSTP_IFSTATE_DISABLED)
   1036 		bstp_disable_port(sc, bif);
   1037 }
   1038 
   1039 void
   1040 bstp_tick(void *arg)
   1041 {
   1042 	struct bridge_softc *sc = arg;
   1043 	struct bridge_iflist *bif;
   1044 	int s;
   1045 
   1046 	s = splnet();
   1047 
   1048 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
   1049 		if ((bif->bif_flags & IFBIF_STP) == 0)
   1050 			continue;
   1051 		/*
   1052 		 * XXX This can cause a lag in "link does away"
   1053 		 * XXX and "spanning tree gets updated".  We need
   1054 		 * XXX come sort of callback from the link state
   1055 		 * XXX update code to kick spanning tree.
   1056 		 * XXX --thorpej (at) netbsd.org
   1057 		 */
   1058 		bstp_ifupdstatus(sc, bif);
   1059 	}
   1060 
   1061 	if (bstp_timer_expired(&sc->sc_hello_timer, sc->sc_hello_time))
   1062 		bstp_hello_timer_expiry(sc);
   1063 
   1064 	if (bstp_timer_expired(&sc->sc_tcn_timer, sc->sc_bridge_hello_time))
   1065 		bstp_tcn_timer_expiry(sc);
   1066 
   1067 	if (bstp_timer_expired(&sc->sc_topology_change_timer,
   1068 	    sc->sc_topology_change_time))
   1069 		bstp_topology_change_timer_expiry(sc);
   1070 
   1071 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
   1072 		if ((bif->bif_flags & IFBIF_STP) == 0)
   1073 			continue;
   1074 		if (bstp_timer_expired(&bif->bif_message_age_timer,
   1075 		    sc->sc_max_age))
   1076 			bstp_message_age_timer_expiry(sc, bif);
   1077 	}
   1078 
   1079 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
   1080 		if ((bif->bif_flags & IFBIF_STP) == 0)
   1081 			continue;
   1082 		if (bstp_timer_expired(&bif->bif_forward_delay_timer,
   1083 		    sc->sc_forward_delay))
   1084 			bstp_forward_delay_timer_expiry(sc, bif);
   1085 
   1086 		if (bstp_timer_expired(&bif->bif_hold_timer,
   1087 		    sc->sc_hold_time))
   1088 			bstp_hold_timer_expiry(sc, bif);
   1089 	}
   1090 
   1091 	if (sc->sc_if.if_flags & IFF_RUNNING)
   1092 		callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
   1093 
   1094 	splx(s);
   1095 }
   1096 
   1097 void
   1098 bstp_timer_start(struct bridge_timer *t, uint16_t v)
   1099 {
   1100 	t->value = v;
   1101 	t->active = 1;
   1102 }
   1103 
   1104 void
   1105 bstp_timer_stop(struct bridge_timer *t)
   1106 {
   1107 	t->value = 0;
   1108 	t->active = 0;
   1109 }
   1110 
   1111 int
   1112 bstp_timer_expired(struct bridge_timer *t, uint16_t v)
   1113 {
   1114 	if (t->active == 0)
   1115 		return (0);
   1116 	t->value += BSTP_TICK_VAL;
   1117 	if (t->value >= v) {
   1118 		bstp_timer_stop(t);
   1119 		return (1);
   1120 	}
   1121 	return (0);
   1122 
   1123 }
   1124