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bridgestp.c revision 1.7.12.1
      1 /*	$NetBSD: bridgestp.c,v 1.7.12.1 2006/05/24 15:50:43 tron 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 1.7.12.1 2006/05/24 15:50:43 tron 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;
    359 	struct ether_header *eh;
    360 	struct mbuf *m;
    361 	int s;
    362 
    363 	KASSERT(bif != NULL);
    364 	ifp = bif->bif_ifp;
    365 	if ((ifp->if_flags & IFF_RUNNING) == 0)
    366 		return;
    367 
    368 	MGETHDR(m, M_DONTWAIT, MT_DATA);
    369 	if (m == NULL)
    370 		return;
    371 
    372 	m->m_pkthdr.rcvif = ifp;
    373 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
    374 	m->m_len = m->m_pkthdr.len;
    375 
    376 	eh = mtod(m, struct ether_header *);
    377 
    378 	memcpy(eh->ether_shost, LLADDR(ifp->if_sadl), ETHER_ADDR_LEN);
    379 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
    380 	eh->ether_type = htons(sizeof(bpdu));
    381 
    382 	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
    383 	bpdu.tbu_ctl = LLC_UI;
    384 	bpdu.tbu_protoid = 0;
    385 	bpdu.tbu_protover = 0;
    386 	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
    387 
    388 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
    389 
    390 	s = splnet();
    391 	bridge_enqueue(sc, ifp, m, 0);
    392 	splx(s);
    393 }
    394 
    395 void
    396 bstp_configuration_update(struct bridge_softc *sc)
    397 {
    398 	bstp_root_selection(sc);
    399 	bstp_designated_port_selection(sc);
    400 }
    401 
    402 void
    403 bstp_root_selection(struct bridge_softc *sc)
    404 {
    405 	struct bridge_iflist *root_port = NULL, *bif;
    406 
    407 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    408 		if ((bif->bif_flags & IFBIF_STP) == 0)
    409 			continue;
    410 		if (bstp_designated_port(sc, bif))
    411 			continue;
    412 		if (bif->bif_state == BSTP_IFSTATE_DISABLED)
    413 			continue;
    414 		if (bif->bif_designated_root >= sc->sc_bridge_id)
    415 			continue;
    416 		if (root_port == NULL)
    417 			goto set_port;
    418 
    419 		if (bif->bif_designated_root < root_port->bif_designated_root)
    420 			goto set_port;
    421 		if (bif->bif_designated_root > root_port->bif_designated_root)
    422 			continue;
    423 
    424 		if ((bif->bif_designated_cost + bif->bif_path_cost) <
    425 		    (root_port->bif_designated_cost + root_port->bif_path_cost))
    426 			goto set_port;
    427 		if ((bif->bif_designated_cost + bif->bif_path_cost) >
    428 		    (root_port->bif_designated_cost + root_port->bif_path_cost))
    429 			continue;
    430 
    431 		if (bif->bif_designated_bridge <
    432 		    root_port->bif_designated_bridge)
    433 			goto set_port;
    434 		if (bif->bif_designated_bridge >
    435 		    root_port->bif_designated_bridge)
    436 			continue;
    437 
    438 		if (bif->bif_designated_port < root_port->bif_designated_port)
    439 			goto set_port;
    440 		if (bif->bif_designated_port > root_port->bif_designated_port)
    441 			continue;
    442 
    443 		if (bif->bif_port_id >= root_port->bif_port_id)
    444 			continue;
    445 set_port:
    446 		root_port = bif;
    447 	}
    448 
    449 	sc->sc_root_port = root_port;
    450 	if (root_port == NULL) {
    451 		sc->sc_designated_root = sc->sc_bridge_id;
    452 		sc->sc_root_path_cost = 0;
    453 	} else {
    454 		sc->sc_designated_root = root_port->bif_designated_root;
    455 		sc->sc_root_path_cost = root_port->bif_designated_cost +
    456 		    root_port->bif_path_cost;
    457 	}
    458 }
    459 
    460 void
    461 bstp_designated_port_selection(struct bridge_softc *sc)
    462 {
    463 	struct bridge_iflist *bif;
    464 
    465 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    466 		if ((bif->bif_flags & IFBIF_STP) == 0)
    467 			continue;
    468 		if (bstp_designated_port(sc, bif))
    469 			goto designated;
    470 		if (bif->bif_designated_root != sc->sc_designated_root)
    471 			goto designated;
    472 
    473 		if (sc->sc_root_path_cost < bif->bif_designated_cost)
    474 			goto designated;
    475 		if (sc->sc_root_path_cost > bif->bif_designated_cost)
    476 			continue;
    477 
    478 		if (sc->sc_bridge_id < bif->bif_designated_bridge)
    479 			goto designated;
    480 		if (sc->sc_bridge_id > bif->bif_designated_bridge)
    481 			continue;
    482 
    483 		if (bif->bif_port_id > bif->bif_designated_port)
    484 			continue;
    485 designated:
    486 		bstp_become_designated_port(sc, bif);
    487 	}
    488 }
    489 
    490 void
    491 bstp_become_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    492 {
    493 	bif->bif_designated_root = sc->sc_designated_root;
    494 	bif->bif_designated_cost = sc->sc_root_path_cost;
    495 	bif->bif_designated_bridge = sc->sc_bridge_id;
    496 	bif->bif_designated_port = bif->bif_port_id;
    497 }
    498 
    499 void
    500 bstp_port_state_selection(struct bridge_softc *sc)
    501 {
    502 	struct bridge_iflist *bif;
    503 
    504 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    505 		if ((bif->bif_flags & IFBIF_STP) == 0)
    506 			continue;
    507 		if (bif == sc->sc_root_port) {
    508 			bif->bif_config_pending = 0;
    509 			bif->bif_topology_change_acknowledge = 0;
    510 			bstp_make_forwarding(sc, bif);
    511 		} else if (bstp_designated_port(sc, bif)) {
    512 			bstp_timer_stop(&bif->bif_message_age_timer);
    513 			bstp_make_forwarding(sc, bif);
    514 		} else {
    515 			bif->bif_config_pending = 0;
    516 			bif->bif_topology_change_acknowledge = 0;
    517 			bstp_make_blocking(sc, bif);
    518 		}
    519 	}
    520 }
    521 
    522 void
    523 bstp_make_forwarding(struct bridge_softc *sc, struct bridge_iflist *bif)
    524 {
    525 	if (bif->bif_state == BSTP_IFSTATE_BLOCKING) {
    526 		bstp_set_port_state(bif, BSTP_IFSTATE_LISTENING);
    527 		bstp_timer_start(&bif->bif_forward_delay_timer, 0);
    528 	}
    529 }
    530 
    531 void
    532 bstp_make_blocking(struct bridge_softc *sc, struct bridge_iflist *bif)
    533 {
    534 	if ((bif->bif_state != BSTP_IFSTATE_DISABLED) &&
    535 	    (bif->bif_state != BSTP_IFSTATE_BLOCKING)) {
    536 		if ((bif->bif_state == BSTP_IFSTATE_FORWARDING) ||
    537 		    (bif->bif_state == BSTP_IFSTATE_LEARNING)) {
    538 			if (bif->bif_change_detection_enabled) {
    539 				bstp_topology_change_detection(sc);
    540 			}
    541 		}
    542 		bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
    543 		bstp_timer_stop(&bif->bif_forward_delay_timer);
    544 	}
    545 }
    546 
    547 void
    548 bstp_set_port_state(struct bridge_iflist *bif, uint8_t state)
    549 {
    550 	bif->bif_state = state;
    551 }
    552 
    553 void
    554 bstp_topology_change_detection(struct bridge_softc *sc)
    555 {
    556 	if (bstp_root_bridge(sc)) {
    557 		sc->sc_topology_change = 1;
    558 		bstp_timer_start(&sc->sc_topology_change_timer, 0);
    559 	} else if (!sc->sc_topology_change_detected) {
    560 		bstp_transmit_tcn(sc);
    561 		bstp_timer_start(&sc->sc_tcn_timer, 0);
    562 	}
    563 	sc->sc_topology_change_detected = 1;
    564 }
    565 
    566 void
    567 bstp_topology_change_acknowledged(struct bridge_softc *sc)
    568 {
    569 	sc->sc_topology_change_detected = 0;
    570 	bstp_timer_stop(&sc->sc_tcn_timer);
    571 }
    572 
    573 void
    574 bstp_acknowledge_topology_change(struct bridge_softc *sc,
    575     struct bridge_iflist *bif)
    576 {
    577 	bif->bif_topology_change_acknowledge = 1;
    578 	bstp_transmit_config(sc, bif);
    579 }
    580 
    581 struct mbuf *
    582 bstp_input(struct ifnet *ifp, struct mbuf *m)
    583 {
    584 	struct bridge_softc *sc = ifp->if_bridge;
    585 	struct bridge_iflist *bif = NULL;
    586 	struct ether_header *eh;
    587 	struct bstp_tbpdu tpdu;
    588 	struct bstp_cbpdu cpdu;
    589 	struct bstp_config_unit cu;
    590 	struct bstp_tcn_unit tu;
    591 	uint16_t len;
    592 
    593 	eh = mtod(m, struct ether_header *);
    594 
    595 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    596 		if ((bif->bif_flags & IFBIF_STP) == 0)
    597 			continue;
    598 		if (bif->bif_ifp == ifp)
    599 			break;
    600 	}
    601 	if (bif == NULL)
    602 		goto out;
    603 
    604 	len = ntohs(eh->ether_type);
    605 	if (len < sizeof(tpdu))
    606 		goto out;
    607 
    608 	m_adj(m, ETHER_HDR_LEN);
    609 
    610 	if (m->m_pkthdr.len > len)
    611 		m_adj(m, len - m->m_pkthdr.len);
    612 	if (m->m_len < sizeof(tpdu) &&
    613 	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
    614 		goto out;
    615 
    616 	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
    617 
    618 	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
    619 	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
    620 	    tpdu.tbu_ctl != LLC_UI)
    621 		goto out;
    622 	if (tpdu.tbu_protoid != 0 || tpdu.tbu_protover != 0)
    623 		goto out;
    624 
    625 	switch (tpdu.tbu_bpdutype) {
    626 	case BSTP_MSGTYPE_TCN:
    627 		tu.tu_message_type = tpdu.tbu_bpdutype;
    628 		bstp_received_tcn_bpdu(sc, bif, &tu);
    629 		break;
    630 	case BSTP_MSGTYPE_CFG:
    631 		if (m->m_len < sizeof(cpdu) &&
    632 		    (m = m_pullup(m, sizeof(cpdu))) == NULL)
    633 			goto out;
    634 		memcpy(&cpdu, mtod(m, caddr_t), sizeof(cpdu));
    635 
    636 		cu.cu_rootid =
    637 		    (((uint64_t)ntohs(cpdu.cbu_rootpri)) << 48) |
    638 		    (((uint64_t)cpdu.cbu_rootaddr[0]) << 40) |
    639 		    (((uint64_t)cpdu.cbu_rootaddr[1]) << 32) |
    640 		    (((uint64_t)cpdu.cbu_rootaddr[2]) << 24) |
    641 		    (((uint64_t)cpdu.cbu_rootaddr[3]) << 16) |
    642 		    (((uint64_t)cpdu.cbu_rootaddr[4]) << 8) |
    643 		    (((uint64_t)cpdu.cbu_rootaddr[5]) << 0);
    644 
    645 		cu.cu_bridge_id =
    646 		    (((uint64_t)ntohs(cpdu.cbu_bridgepri)) << 48) |
    647 		    (((uint64_t)cpdu.cbu_bridgeaddr[0]) << 40) |
    648 		    (((uint64_t)cpdu.cbu_bridgeaddr[1]) << 32) |
    649 		    (((uint64_t)cpdu.cbu_bridgeaddr[2]) << 24) |
    650 		    (((uint64_t)cpdu.cbu_bridgeaddr[3]) << 16) |
    651 		    (((uint64_t)cpdu.cbu_bridgeaddr[4]) << 8) |
    652 		    (((uint64_t)cpdu.cbu_bridgeaddr[5]) << 0);
    653 
    654 		cu.cu_root_path_cost = ntohl(cpdu.cbu_rootpathcost);
    655 		cu.cu_message_age = ntohs(cpdu.cbu_messageage);
    656 		cu.cu_max_age = ntohs(cpdu.cbu_maxage);
    657 		cu.cu_hello_time = ntohs(cpdu.cbu_hellotime);
    658 		cu.cu_forward_delay = ntohs(cpdu.cbu_forwarddelay);
    659 		cu.cu_port_id = ntohs(cpdu.cbu_portid);
    660 		cu.cu_message_type = cpdu.cbu_bpdutype;
    661 		cu.cu_topology_change_acknowledgment =
    662 		    (cpdu.cbu_flags & BSTP_FLAG_TCA) ? 1 : 0;
    663 		cu.cu_topology_change =
    664 		    (cpdu.cbu_flags & BSTP_FLAG_TC) ? 1 : 0;
    665 		bstp_received_config_bpdu(sc, bif, &cu);
    666 		break;
    667 	default:
    668 		goto out;
    669 	}
    670 
    671  out:
    672 	if (m)
    673 		m_freem(m);
    674 	return (NULL);
    675 }
    676 
    677 void
    678 bstp_received_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
    679     struct bstp_config_unit *cu)
    680 {
    681 	int root;
    682 
    683 	root = bstp_root_bridge(sc);
    684 
    685 	if (bif->bif_state != BSTP_IFSTATE_DISABLED) {
    686 		if (bstp_supersedes_port_info(sc, bif, cu)) {
    687 			bstp_record_config_information(sc, bif, cu);
    688 			bstp_configuration_update(sc);
    689 			bstp_port_state_selection(sc);
    690 
    691 			if ((bstp_root_bridge(sc) == 0) && root) {
    692 				bstp_timer_stop(&sc->sc_hello_timer);
    693 
    694 				if (sc->sc_topology_change_detected) {
    695 					bstp_timer_stop(
    696 					    &sc->sc_topology_change_timer);
    697 					bstp_transmit_tcn(sc);
    698 					bstp_timer_start(&sc->sc_tcn_timer, 0);
    699 				}
    700 			}
    701 
    702 			if (bif == sc->sc_root_port) {
    703 				bstp_record_config_timeout_values(sc, cu);
    704 				bstp_config_bpdu_generation(sc);
    705 
    706 				if (cu->cu_topology_change_acknowledgment)
    707 					bstp_topology_change_acknowledged(sc);
    708 			}
    709 		} else if (bstp_designated_port(sc, bif))
    710 			bstp_transmit_config(sc, bif);
    711 	}
    712 }
    713 
    714 void
    715 bstp_received_tcn_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
    716     struct bstp_tcn_unit *tcn)
    717 {
    718 	if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
    719 	    bstp_designated_port(sc, bif)) {
    720 		bstp_topology_change_detection(sc);
    721 		bstp_acknowledge_topology_change(sc, bif);
    722 	}
    723 }
    724 
    725 void
    726 bstp_hello_timer_expiry(struct bridge_softc *sc)
    727 {
    728 	bstp_config_bpdu_generation(sc);
    729 	bstp_timer_start(&sc->sc_hello_timer, 0);
    730 }
    731 
    732 void
    733 bstp_message_age_timer_expiry(struct bridge_softc *sc,
    734     struct bridge_iflist *bif)
    735 {
    736 	int root;
    737 
    738 	root = bstp_root_bridge(sc);
    739 	bstp_become_designated_port(sc, bif);
    740 	bstp_configuration_update(sc);
    741 	bstp_port_state_selection(sc);
    742 
    743 	if ((bstp_root_bridge(sc)) && (root == 0)) {
    744 		sc->sc_max_age = sc->sc_bridge_max_age;
    745 		sc->sc_hello_time = sc->sc_bridge_hello_time;
    746 		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    747 
    748 		bstp_topology_change_detection(sc);
    749 		bstp_timer_stop(&sc->sc_tcn_timer);
    750 		bstp_config_bpdu_generation(sc);
    751 		bstp_timer_start(&sc->sc_hello_timer, 0);
    752 	}
    753 }
    754 
    755 void
    756 bstp_forward_delay_timer_expiry(struct bridge_softc *sc,
    757     struct bridge_iflist *bif)
    758 {
    759 	if (bif->bif_state == BSTP_IFSTATE_LISTENING) {
    760 		bstp_set_port_state(bif, BSTP_IFSTATE_LEARNING);
    761 		bstp_timer_start(&bif->bif_forward_delay_timer, 0);
    762 	} else if (bif->bif_state == BSTP_IFSTATE_LEARNING) {
    763 		bstp_set_port_state(bif, BSTP_IFSTATE_FORWARDING);
    764 		if (bstp_designated_for_some_port(sc) &&
    765 		    bif->bif_change_detection_enabled)
    766 			bstp_topology_change_detection(sc);
    767 	}
    768 }
    769 
    770 int
    771 bstp_designated_for_some_port(struct bridge_softc *sc)
    772 {
    773 
    774 	struct bridge_iflist *bif;
    775 
    776 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    777 		if ((bif->bif_flags & IFBIF_STP) == 0)
    778 			continue;
    779 		if (bif->bif_designated_bridge == sc->sc_bridge_id)
    780 			return (1);
    781 	}
    782 	return (0);
    783 }
    784 
    785 void
    786 bstp_tcn_timer_expiry(struct bridge_softc *sc)
    787 {
    788 	bstp_transmit_tcn(sc);
    789 	bstp_timer_start(&sc->sc_tcn_timer, 0);
    790 }
    791 
    792 void
    793 bstp_topology_change_timer_expiry(struct bridge_softc *sc)
    794 {
    795 	sc->sc_topology_change_detected = 0;
    796 	sc->sc_topology_change = 0;
    797 }
    798 
    799 void
    800 bstp_hold_timer_expiry(struct bridge_softc *sc, struct bridge_iflist *bif)
    801 {
    802 	if (bif->bif_config_pending)
    803 		bstp_transmit_config(sc, bif);
    804 }
    805 
    806 void
    807 bstp_initialization(struct bridge_softc *sc)
    808 {
    809 	struct bridge_iflist *bif, *mif;
    810 
    811 	mif = NULL;
    812 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    813 		if ((bif->bif_flags & IFBIF_STP) == 0)
    814 			continue;
    815 		if (bif->bif_ifp->if_type != IFT_ETHER)
    816 			continue;
    817 		bif->bif_port_id = (bif->bif_priority << 8) |
    818 		    (bif->bif_ifp->if_index & 0xff);
    819 
    820 		if (mif == NULL) {
    821 			mif = bif;
    822 			continue;
    823 		}
    824 		if (memcmp(LLADDR(bif->bif_ifp->if_sadl),
    825 		    LLADDR(mif->bif_ifp->if_sadl), ETHER_ADDR_LEN) < 0) {
    826 			mif = bif;
    827 			continue;
    828 		}
    829 	}
    830 	if (mif == NULL) {
    831 		bstp_stop(sc);
    832 		return;
    833 	}
    834 
    835 	sc->sc_bridge_id =
    836 	    (((uint64_t)sc->sc_bridge_priority) << 48) |
    837 	    (((uint64_t)LLADDR(mif->bif_ifp->if_sadl)[0]) << 40) |
    838 	    (((uint64_t)LLADDR(mif->bif_ifp->if_sadl)[1]) << 32) |
    839 	    (LLADDR(mif->bif_ifp->if_sadl)[2] << 24) |
    840 	    (LLADDR(mif->bif_ifp->if_sadl)[3] << 16) |
    841 	    (LLADDR(mif->bif_ifp->if_sadl)[4] << 8) |
    842 	    (LLADDR(mif->bif_ifp->if_sadl)[5]);
    843 
    844 	sc->sc_designated_root = sc->sc_bridge_id;
    845 	sc->sc_root_path_cost = 0;
    846 	sc->sc_root_port = NULL;
    847 
    848 	sc->sc_max_age = sc->sc_bridge_max_age;
    849 	sc->sc_hello_time = sc->sc_bridge_hello_time;
    850 	sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    851 	sc->sc_topology_change_detected = 0;
    852 	sc->sc_topology_change = 0;
    853 	bstp_timer_stop(&sc->sc_tcn_timer);
    854 	bstp_timer_stop(&sc->sc_topology_change_timer);
    855 
    856 	if (callout_pending(&sc->sc_bstpcallout) == 0)
    857 		callout_reset(&sc->sc_bstpcallout, hz,
    858 		    bstp_tick, sc);
    859 
    860 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    861 		if (bif->bif_flags & IFBIF_STP)
    862 			bstp_enable_port(sc, bif);
    863 		else
    864 			bstp_disable_port(sc, bif);
    865 	}
    866 
    867 	bstp_port_state_selection(sc);
    868 	bstp_config_bpdu_generation(sc);
    869 	bstp_timer_start(&sc->sc_hello_timer, 0);
    870 }
    871 
    872 void
    873 bstp_stop(struct bridge_softc *sc)
    874 {
    875 	struct bridge_iflist *bif;
    876 
    877 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    878 		bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
    879 		bstp_timer_stop(&bif->bif_hold_timer);
    880 		bstp_timer_stop(&bif->bif_message_age_timer);
    881 		bstp_timer_stop(&bif->bif_forward_delay_timer);
    882 	}
    883 
    884 	callout_stop(&sc->sc_bstpcallout);
    885 
    886 	bstp_timer_stop(&sc->sc_topology_change_timer);
    887 	bstp_timer_stop(&sc->sc_tcn_timer);
    888 	bstp_timer_stop(&sc->sc_hello_timer);
    889 
    890 }
    891 
    892 void
    893 bstp_initialize_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    894 {
    895 	bstp_become_designated_port(sc, bif);
    896 	bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
    897 	bif->bif_topology_change_acknowledge = 0;
    898 	bif->bif_config_pending = 0;
    899 	bif->bif_change_detection_enabled = 1;
    900 	bstp_timer_stop(&bif->bif_message_age_timer);
    901 	bstp_timer_stop(&bif->bif_forward_delay_timer);
    902 	bstp_timer_stop(&bif->bif_hold_timer);
    903 }
    904 
    905 void
    906 bstp_enable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    907 {
    908 	bstp_initialize_port(sc, bif);
    909 	bstp_port_state_selection(sc);
    910 }
    911 
    912 void
    913 bstp_disable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
    914 {
    915 	int root;
    916 
    917 	root = bstp_root_bridge(sc);
    918 	bstp_become_designated_port(sc, bif);
    919 	bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
    920 	bif->bif_topology_change_acknowledge = 0;
    921 	bif->bif_config_pending = 0;
    922 	bstp_timer_stop(&bif->bif_message_age_timer);
    923 	bstp_timer_stop(&bif->bif_forward_delay_timer);
    924 	bstp_configuration_update(sc);
    925 	bstp_port_state_selection(sc);
    926 
    927 	if (bstp_root_bridge(sc) && (root == 0)) {
    928 		sc->sc_max_age = sc->sc_bridge_max_age;
    929 		sc->sc_hello_time = sc->sc_bridge_hello_time;
    930 		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    931 
    932 		bstp_topology_change_detection(sc);
    933 		bstp_timer_stop(&sc->sc_tcn_timer);
    934 		bstp_config_bpdu_generation(sc);
    935 		bstp_timer_start(&sc->sc_hello_timer, 0);
    936 	}
    937 }
    938 
    939 void
    940 bstp_set_bridge_priority(struct bridge_softc *sc, uint64_t new_bridge_id)
    941 {
    942 	struct bridge_iflist *bif;
    943 	int root;
    944 
    945 	root = bstp_root_bridge(sc);
    946 
    947 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
    948 		if ((bif->bif_flags & IFBIF_STP) == 0)
    949 			continue;
    950 		if (bstp_designated_port(sc, bif))
    951 			bif->bif_designated_bridge = new_bridge_id;
    952 	}
    953 
    954 	sc->sc_bridge_id = new_bridge_id;
    955 
    956 	bstp_configuration_update(sc);
    957 	bstp_port_state_selection(sc);
    958 
    959 	if (bstp_root_bridge(sc) && (root == 0)) {
    960 		sc->sc_max_age = sc->sc_bridge_max_age;
    961 		sc->sc_hello_time = sc->sc_bridge_hello_time;
    962 		sc->sc_forward_delay = sc->sc_bridge_forward_delay;
    963 
    964 		bstp_topology_change_detection(sc);
    965 		bstp_timer_stop(&sc->sc_tcn_timer);
    966 		bstp_config_bpdu_generation(sc);
    967 		bstp_timer_start(&sc->sc_hello_timer, 0);
    968 	}
    969 }
    970 
    971 void
    972 bstp_set_port_priority(struct bridge_softc *sc, struct bridge_iflist *bif,
    973     uint16_t new_port_id)
    974 {
    975 	if (bstp_designated_port(sc, bif))
    976 		bif->bif_designated_port = new_port_id;
    977 
    978 	bif->bif_port_id = new_port_id;
    979 
    980 	if ((sc->sc_bridge_id == bif->bif_designated_bridge) &&
    981 	    (bif->bif_port_id < bif->bif_designated_port)) {
    982 		bstp_become_designated_port(sc, bif);
    983 		bstp_port_state_selection(sc);
    984 	}
    985 }
    986 
    987 void
    988 bstp_set_path_cost(struct bridge_softc *sc, struct bridge_iflist *bif,
    989     uint32_t path_cost)
    990 {
    991 	bif->bif_path_cost = path_cost;
    992 	bstp_configuration_update(sc);
    993 	bstp_port_state_selection(sc);
    994 }
    995 
    996 void
    997 bstp_enable_change_detection(struct bridge_iflist *bif)
    998 {
    999 	bif->bif_change_detection_enabled = 1;
   1000 }
   1001 
   1002 void
   1003 bstp_disable_change_detection(struct bridge_iflist *bif)
   1004 {
   1005 	bif->bif_change_detection_enabled = 0;
   1006 }
   1007 
   1008 void
   1009 bstp_ifupdstatus(struct bridge_softc *sc, struct bridge_iflist *bif)
   1010 {
   1011 	struct ifnet *ifp = bif->bif_ifp;
   1012 
   1013 	if (ifp->if_flags & IFF_UP) {
   1014 	 	switch (ifp->if_link_state) {
   1015 		case LINK_STATE_UNKNOWN:
   1016 			/*
   1017 			 * Just enable the port if the link state is
   1018 			 * unknown.
   1019 			 */
   1020 			if (bif->bif_state == BSTP_IFSTATE_DISABLED)
   1021 				bstp_enable_port(sc, bif);
   1022 			break;
   1023 
   1024 		case LINK_STATE_UP:
   1025 			if (bif->bif_state == BSTP_IFSTATE_DISABLED)
   1026 				bstp_enable_port(sc, bif);
   1027 			break;
   1028 
   1029 		case LINK_STATE_DOWN:
   1030 			if (bif->bif_state != BSTP_IFSTATE_DISABLED)
   1031 				bstp_disable_port(sc, bif);
   1032 			break;
   1033 		}
   1034 		return;
   1035 	}
   1036 
   1037 	if (bif->bif_state != BSTP_IFSTATE_DISABLED)
   1038 		bstp_disable_port(sc, bif);
   1039 }
   1040 
   1041 void
   1042 bstp_tick(void *arg)
   1043 {
   1044 	struct bridge_softc *sc = arg;
   1045 	struct bridge_iflist *bif;
   1046 	int s;
   1047 
   1048 	s = splnet();
   1049 
   1050 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
   1051 		if ((bif->bif_flags & IFBIF_STP) == 0)
   1052 			continue;
   1053 		/*
   1054 		 * XXX This can cause a lag in "link does away"
   1055 		 * XXX and "spanning tree gets updated".  We need
   1056 		 * XXX come sort of callback from the link state
   1057 		 * XXX update code to kick spanning tree.
   1058 		 * XXX --thorpej (at) NetBSD.org
   1059 		 */
   1060 		bstp_ifupdstatus(sc, bif);
   1061 	}
   1062 
   1063 	if (bstp_timer_expired(&sc->sc_hello_timer, sc->sc_hello_time))
   1064 		bstp_hello_timer_expiry(sc);
   1065 
   1066 	if (bstp_timer_expired(&sc->sc_tcn_timer, sc->sc_bridge_hello_time))
   1067 		bstp_tcn_timer_expiry(sc);
   1068 
   1069 	if (bstp_timer_expired(&sc->sc_topology_change_timer,
   1070 	    sc->sc_topology_change_time))
   1071 		bstp_topology_change_timer_expiry(sc);
   1072 
   1073 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
   1074 		if ((bif->bif_flags & IFBIF_STP) == 0)
   1075 			continue;
   1076 		if (bstp_timer_expired(&bif->bif_message_age_timer,
   1077 		    sc->sc_max_age))
   1078 			bstp_message_age_timer_expiry(sc, bif);
   1079 	}
   1080 
   1081 	LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
   1082 		if ((bif->bif_flags & IFBIF_STP) == 0)
   1083 			continue;
   1084 		if (bstp_timer_expired(&bif->bif_forward_delay_timer,
   1085 		    sc->sc_forward_delay))
   1086 			bstp_forward_delay_timer_expiry(sc, bif);
   1087 
   1088 		if (bstp_timer_expired(&bif->bif_hold_timer,
   1089 		    sc->sc_hold_time))
   1090 			bstp_hold_timer_expiry(sc, bif);
   1091 	}
   1092 
   1093 	if (sc->sc_if.if_flags & IFF_RUNNING)
   1094 		callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
   1095 
   1096 	splx(s);
   1097 }
   1098 
   1099 void
   1100 bstp_timer_start(struct bridge_timer *t, uint16_t v)
   1101 {
   1102 	t->value = v;
   1103 	t->active = 1;
   1104 }
   1105 
   1106 void
   1107 bstp_timer_stop(struct bridge_timer *t)
   1108 {
   1109 	t->value = 0;
   1110 	t->active = 0;
   1111 }
   1112 
   1113 int
   1114 bstp_timer_expired(struct bridge_timer *t, uint16_t v)
   1115 {
   1116 	if (t->active == 0)
   1117 		return (0);
   1118 	t->value += BSTP_TICK_VAL;
   1119 	if (t->value >= v) {
   1120 		bstp_timer_stop(t);
   1121 		return (1);
   1122 	}
   1123 	return (0);
   1124 
   1125 }
   1126