xref: /freebsd/sys/net/bridgestp.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
1 /*	$NetBSD: bridgestp.c,v 1.5 2003/11/28 08:56:48 keihan Exp $	*/
2 
3 /*
4  * Copyright (c) 2000 Jason L. Wright (jason@thought.net)
5  * Copyright (c) 2006 Andrew Thompson (thompsa@FreeBSD.org)
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
26  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  *
29  * OpenBSD: bridgestp.c,v 1.5 2001/03/22 03:48:29 jason Exp
30  */
31 
32 /*
33  * Implementation of the spanning tree protocol as defined in
34  * ISO/IEC 802.1D-2004, June 9, 2004.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "opt_route.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/mbuf.h>
45 #include <sys/socket.h>
46 #include <sys/sockio.h>
47 #include <sys/kernel.h>
48 #include <sys/callout.h>
49 #include <sys/module.h>
50 #include <sys/proc.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/taskqueue.h>
54 #include <sys/vimage.h>
55 
56 #include <net/if.h>
57 #include <net/if_dl.h>
58 #include <net/if_types.h>
59 #include <net/if_llc.h>
60 #include <net/if_media.h>
61 #include <net/route.h>
62 #include <net/vnet.h>
63 
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #include <netinet/in_var.h>
67 #include <netinet/if_ether.h>
68 #include <net/bridgestp.h>
69 
70 #ifdef	BRIDGESTP_DEBUG
71 #define	DPRINTF(fmt, arg...)	printf("bstp: " fmt, ##arg)
72 #else
73 #define	DPRINTF(fmt, arg...)
74 #endif
75 
76 #define	PV2ADDR(pv, eaddr)	do {		\
77 	eaddr[0] = pv >> 40;			\
78 	eaddr[1] = pv >> 32;			\
79 	eaddr[2] = pv >> 24;			\
80 	eaddr[3] = pv >> 16;			\
81 	eaddr[4] = pv >> 8;			\
82 	eaddr[5] = pv >> 0;			\
83 } while (0)
84 
85 #define	INFO_BETTER	1
86 #define	INFO_SAME	0
87 #define	INFO_WORSE	-1
88 
89 const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
90 
91 LIST_HEAD(, bstp_state) bstp_list;
92 static struct mtx	bstp_list_mtx;
93 
94 static void	bstp_transmit(struct bstp_state *, struct bstp_port *);
95 static void	bstp_transmit_bpdu(struct bstp_state *, struct bstp_port *);
96 static void	bstp_transmit_tcn(struct bstp_state *, struct bstp_port *);
97 static void	bstp_decode_bpdu(struct bstp_port *, struct bstp_cbpdu *,
98 		    struct bstp_config_unit *);
99 static void	bstp_send_bpdu(struct bstp_state *, struct bstp_port *,
100 		    struct bstp_cbpdu *);
101 static int	bstp_pdu_flags(struct bstp_port *);
102 static void	bstp_received_stp(struct bstp_state *, struct bstp_port *,
103 		    struct mbuf **, struct bstp_tbpdu *);
104 static void	bstp_received_rstp(struct bstp_state *, struct bstp_port *,
105 		    struct mbuf **, struct bstp_tbpdu *);
106 static void	bstp_received_tcn(struct bstp_state *, struct bstp_port *,
107 		    struct bstp_tcn_unit *);
108 static void	bstp_received_bpdu(struct bstp_state *, struct bstp_port *,
109 		    struct bstp_config_unit *);
110 static int	bstp_pdu_rcvtype(struct bstp_port *, struct bstp_config_unit *);
111 static int	bstp_pdu_bettersame(struct bstp_port *, int);
112 static int	bstp_info_cmp(struct bstp_pri_vector *,
113 		    struct bstp_pri_vector *);
114 static int	bstp_info_superior(struct bstp_pri_vector *,
115 		    struct bstp_pri_vector *);
116 static void	bstp_assign_roles(struct bstp_state *);
117 static void	bstp_update_roles(struct bstp_state *, struct bstp_port *);
118 static void	bstp_update_state(struct bstp_state *, struct bstp_port *);
119 static void	bstp_update_tc(struct bstp_port *);
120 static void	bstp_update_info(struct bstp_port *);
121 static void	bstp_set_other_tcprop(struct bstp_port *);
122 static void	bstp_set_all_reroot(struct bstp_state *);
123 static void	bstp_set_all_sync(struct bstp_state *);
124 static void	bstp_set_port_state(struct bstp_port *, int);
125 static void	bstp_set_port_role(struct bstp_port *, int);
126 static void	bstp_set_port_proto(struct bstp_port *, int);
127 static void	bstp_set_port_tc(struct bstp_port *, int);
128 static void	bstp_set_timer_tc(struct bstp_port *);
129 static void	bstp_set_timer_msgage(struct bstp_port *);
130 static int	bstp_rerooted(struct bstp_state *, struct bstp_port *);
131 static uint32_t	bstp_calc_path_cost(struct bstp_port *);
132 static void	bstp_notify_state(void *, int);
133 static void	bstp_notify_rtage(void *, int);
134 static void	bstp_ifupdstatus(struct bstp_state *, struct bstp_port *);
135 static void	bstp_enable_port(struct bstp_state *, struct bstp_port *);
136 static void	bstp_disable_port(struct bstp_state *, struct bstp_port *);
137 static void	bstp_tick(void *);
138 static void	bstp_timer_start(struct bstp_timer *, uint16_t);
139 static void	bstp_timer_stop(struct bstp_timer *);
140 static void	bstp_timer_latch(struct bstp_timer *);
141 static int	bstp_timer_expired(struct bstp_timer *);
142 static void	bstp_hello_timer_expiry(struct bstp_state *,
143 		    struct bstp_port *);
144 static void	bstp_message_age_expiry(struct bstp_state *,
145 		    struct bstp_port *);
146 static void	bstp_migrate_delay_expiry(struct bstp_state *,
147 		    struct bstp_port *);
148 static void	bstp_edge_delay_expiry(struct bstp_state *,
149 		    struct bstp_port *);
150 static int	bstp_addr_cmp(const uint8_t *, const uint8_t *);
151 static int	bstp_same_bridgeid(uint64_t, uint64_t);
152 static void	bstp_reinit(struct bstp_state *);
153 
154 static void
155 bstp_transmit(struct bstp_state *bs, struct bstp_port *bp)
156 {
157 	if (bs->bs_running == 0)
158 		return;
159 
160 	/*
161 	 * a PDU can only be sent if we have tx quota left and the
162 	 * hello timer is running.
163 	 */
164 	if (bp->bp_hello_timer.active == 0) {
165 		/* Test if it needs to be reset */
166 		bstp_hello_timer_expiry(bs, bp);
167 		return;
168 	}
169 	if (bp->bp_txcount > bs->bs_txholdcount)
170 		/* Ran out of karma */
171 		return;
172 
173 	if (bp->bp_protover == BSTP_PROTO_RSTP) {
174 		bstp_transmit_bpdu(bs, bp);
175 		bp->bp_tc_ack = 0;
176 	} else { /* STP */
177 		switch (bp->bp_role) {
178 			case BSTP_ROLE_DESIGNATED:
179 				bstp_transmit_bpdu(bs, bp);
180 				bp->bp_tc_ack = 0;
181 				break;
182 
183 			case BSTP_ROLE_ROOT:
184 				bstp_transmit_tcn(bs, bp);
185 				break;
186 		}
187 	}
188 	bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
189 	bp->bp_flags &= ~BSTP_PORT_NEWINFO;
190 }
191 
192 static void
193 bstp_transmit_bpdu(struct bstp_state *bs, struct bstp_port *bp)
194 {
195 	struct bstp_cbpdu bpdu;
196 
197 	BSTP_LOCK_ASSERT(bs);
198 
199 	bpdu.cbu_rootpri = htons(bp->bp_desg_pv.pv_root_id >> 48);
200 	PV2ADDR(bp->bp_desg_pv.pv_root_id, bpdu.cbu_rootaddr);
201 
202 	bpdu.cbu_rootpathcost = htonl(bp->bp_desg_pv.pv_cost);
203 
204 	bpdu.cbu_bridgepri = htons(bp->bp_desg_pv.pv_dbridge_id >> 48);
205 	PV2ADDR(bp->bp_desg_pv.pv_dbridge_id, bpdu.cbu_bridgeaddr);
206 
207 	bpdu.cbu_portid = htons(bp->bp_port_id);
208 	bpdu.cbu_messageage = htons(bp->bp_desg_msg_age);
209 	bpdu.cbu_maxage = htons(bp->bp_desg_max_age);
210 	bpdu.cbu_hellotime = htons(bp->bp_desg_htime);
211 	bpdu.cbu_forwarddelay = htons(bp->bp_desg_fdelay);
212 
213 	bpdu.cbu_flags = bstp_pdu_flags(bp);
214 
215 	switch (bp->bp_protover) {
216 		case BSTP_PROTO_STP:
217 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_CFG;
218 			break;
219 
220 		case BSTP_PROTO_RSTP:
221 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_RSTP;
222 			break;
223 	}
224 
225 	bstp_send_bpdu(bs, bp, &bpdu);
226 }
227 
228 static void
229 bstp_transmit_tcn(struct bstp_state *bs, struct bstp_port *bp)
230 {
231 	struct bstp_tbpdu bpdu;
232 	struct ifnet *ifp = bp->bp_ifp;
233 	struct ether_header *eh;
234 	struct mbuf *m;
235 
236 	KASSERT(bp == bs->bs_root_port, ("%s: bad root port\n", __func__));
237 
238 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
239 		return;
240 
241 	MGETHDR(m, M_DONTWAIT, MT_DATA);
242 	if (m == NULL)
243 		return;
244 
245 	m->m_pkthdr.rcvif = ifp;
246 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
247 	m->m_len = m->m_pkthdr.len;
248 
249 	eh = mtod(m, struct ether_header *);
250 
251 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
252 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
253 	eh->ether_type = htons(sizeof(bpdu));
254 
255 	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
256 	bpdu.tbu_ctl = LLC_UI;
257 	bpdu.tbu_protoid = 0;
258 	bpdu.tbu_protover = 0;
259 	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
260 
261 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
262 
263 	bp->bp_txcount++;
264 	ifp->if_transmit(ifp, m);
265 }
266 
267 static void
268 bstp_decode_bpdu(struct bstp_port *bp, struct bstp_cbpdu *cpdu,
269     struct bstp_config_unit *cu)
270 {
271 	int flags;
272 
273 	cu->cu_pv.pv_root_id =
274 	    (((uint64_t)ntohs(cpdu->cbu_rootpri)) << 48) |
275 	    (((uint64_t)cpdu->cbu_rootaddr[0]) << 40) |
276 	    (((uint64_t)cpdu->cbu_rootaddr[1]) << 32) |
277 	    (((uint64_t)cpdu->cbu_rootaddr[2]) << 24) |
278 	    (((uint64_t)cpdu->cbu_rootaddr[3]) << 16) |
279 	    (((uint64_t)cpdu->cbu_rootaddr[4]) << 8) |
280 	    (((uint64_t)cpdu->cbu_rootaddr[5]) << 0);
281 
282 	cu->cu_pv.pv_dbridge_id =
283 	    (((uint64_t)ntohs(cpdu->cbu_bridgepri)) << 48) |
284 	    (((uint64_t)cpdu->cbu_bridgeaddr[0]) << 40) |
285 	    (((uint64_t)cpdu->cbu_bridgeaddr[1]) << 32) |
286 	    (((uint64_t)cpdu->cbu_bridgeaddr[2]) << 24) |
287 	    (((uint64_t)cpdu->cbu_bridgeaddr[3]) << 16) |
288 	    (((uint64_t)cpdu->cbu_bridgeaddr[4]) << 8) |
289 	    (((uint64_t)cpdu->cbu_bridgeaddr[5]) << 0);
290 
291 	cu->cu_pv.pv_cost = ntohl(cpdu->cbu_rootpathcost);
292 	cu->cu_message_age = ntohs(cpdu->cbu_messageage);
293 	cu->cu_max_age = ntohs(cpdu->cbu_maxage);
294 	cu->cu_hello_time = ntohs(cpdu->cbu_hellotime);
295 	cu->cu_forward_delay = ntohs(cpdu->cbu_forwarddelay);
296 	cu->cu_pv.pv_dport_id = ntohs(cpdu->cbu_portid);
297 	cu->cu_pv.pv_port_id = bp->bp_port_id;
298 	cu->cu_message_type = cpdu->cbu_bpdutype;
299 
300 	/* Strip off unused flags in STP mode */
301 	flags = cpdu->cbu_flags;
302 	switch (cpdu->cbu_protover) {
303 		case BSTP_PROTO_STP:
304 			flags &= BSTP_PDU_STPMASK;
305 			/* A STP BPDU explicitly conveys a Designated Port */
306 			cu->cu_role = BSTP_ROLE_DESIGNATED;
307 			break;
308 
309 		case BSTP_PROTO_RSTP:
310 			flags &= BSTP_PDU_RSTPMASK;
311 			break;
312 	}
313 
314 	cu->cu_topology_change_ack =
315 		(flags & BSTP_PDU_F_TCA) ? 1 : 0;
316 	cu->cu_proposal =
317 		(flags & BSTP_PDU_F_P) ? 1 : 0;
318 	cu->cu_agree =
319 		(flags & BSTP_PDU_F_A) ? 1 : 0;
320 	cu->cu_learning =
321 		(flags & BSTP_PDU_F_L) ? 1 : 0;
322 	cu->cu_forwarding =
323 		(flags & BSTP_PDU_F_F) ? 1 : 0;
324 	cu->cu_topology_change =
325 		(flags & BSTP_PDU_F_TC) ? 1 : 0;
326 
327 	switch ((flags & BSTP_PDU_PRMASK) >> BSTP_PDU_PRSHIFT) {
328 		case BSTP_PDU_F_ROOT:
329 			cu->cu_role = BSTP_ROLE_ROOT;
330 			break;
331 		case BSTP_PDU_F_ALT:
332 			cu->cu_role = BSTP_ROLE_ALTERNATE;
333 			break;
334 		case BSTP_PDU_F_DESG:
335 			cu->cu_role = BSTP_ROLE_DESIGNATED;
336 			break;
337 	}
338 }
339 
340 static void
341 bstp_send_bpdu(struct bstp_state *bs, struct bstp_port *bp,
342     struct bstp_cbpdu *bpdu)
343 {
344 	struct ifnet *ifp;
345 	struct mbuf *m;
346 	struct ether_header *eh;
347 
348 	BSTP_LOCK_ASSERT(bs);
349 
350 	ifp = bp->bp_ifp;
351 
352 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
353 		return;
354 
355 	MGETHDR(m, M_DONTWAIT, MT_DATA);
356 	if (m == NULL)
357 		return;
358 
359 	eh = mtod(m, struct ether_header *);
360 
361 	bpdu->cbu_ssap = bpdu->cbu_dsap = LLC_8021D_LSAP;
362 	bpdu->cbu_ctl = LLC_UI;
363 	bpdu->cbu_protoid = htons(BSTP_PROTO_ID);
364 
365 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
366 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
367 
368 	switch (bpdu->cbu_bpdutype) {
369 		case BSTP_MSGTYPE_CFG:
370 			bpdu->cbu_protover = BSTP_PROTO_STP;
371 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_STP_LEN;
372 			eh->ether_type = htons(BSTP_BPDU_STP_LEN);
373 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
374 			    BSTP_BPDU_STP_LEN);
375 			break;
376 
377 		case BSTP_MSGTYPE_RSTP:
378 			bpdu->cbu_protover = BSTP_PROTO_RSTP;
379 			bpdu->cbu_versionlen = htons(0);
380 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_RSTP_LEN;
381 			eh->ether_type = htons(BSTP_BPDU_RSTP_LEN);
382 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
383 			    BSTP_BPDU_RSTP_LEN);
384 			break;
385 
386 		default:
387 			panic("not implemented");
388 	}
389 	m->m_pkthdr.rcvif = ifp;
390 	m->m_len = m->m_pkthdr.len;
391 
392 	bp->bp_txcount++;
393 	ifp->if_transmit(ifp, m);
394 }
395 
396 static int
397 bstp_pdu_flags(struct bstp_port *bp)
398 {
399 	int flags = 0;
400 
401 	if (bp->bp_proposing && bp->bp_state != BSTP_IFSTATE_FORWARDING)
402 		flags |= BSTP_PDU_F_P;
403 
404 	if (bp->bp_agree)
405 		flags |= BSTP_PDU_F_A;
406 
407 	if (bp->bp_tc_timer.active)
408 		flags |= BSTP_PDU_F_TC;
409 
410 	if (bp->bp_tc_ack)
411 		flags |= BSTP_PDU_F_TCA;
412 
413 	switch (bp->bp_state) {
414 		case BSTP_IFSTATE_LEARNING:
415 			flags |= BSTP_PDU_F_L;
416 			break;
417 
418 		case BSTP_IFSTATE_FORWARDING:
419 			flags |= (BSTP_PDU_F_L | BSTP_PDU_F_F);
420 			break;
421 	}
422 
423 	switch (bp->bp_role) {
424 		case BSTP_ROLE_ROOT:
425 			flags |=
426 				(BSTP_PDU_F_ROOT << BSTP_PDU_PRSHIFT);
427 			break;
428 
429 		case BSTP_ROLE_ALTERNATE:
430 		case BSTP_ROLE_BACKUP:	/* fall through */
431 			flags |=
432 				(BSTP_PDU_F_ALT << BSTP_PDU_PRSHIFT);
433 			break;
434 
435 		case BSTP_ROLE_DESIGNATED:
436 			flags |=
437 				(BSTP_PDU_F_DESG << BSTP_PDU_PRSHIFT);
438 			break;
439 	}
440 
441 	/* Strip off unused flags in either mode */
442 	switch (bp->bp_protover) {
443 		case BSTP_PROTO_STP:
444 			flags &= BSTP_PDU_STPMASK;
445 			break;
446 		case BSTP_PROTO_RSTP:
447 			flags &= BSTP_PDU_RSTPMASK;
448 			break;
449 	}
450 	return (flags);
451 }
452 
453 struct mbuf *
454 bstp_input(struct bstp_port *bp, struct ifnet *ifp, struct mbuf *m)
455 {
456 	struct bstp_state *bs = bp->bp_bs;
457 	struct ether_header *eh;
458 	struct bstp_tbpdu tpdu;
459 	uint16_t len;
460 
461 	if (bp->bp_active == 0) {
462 		m_freem(m);
463 		return (NULL);
464 	}
465 
466 	BSTP_LOCK(bs);
467 
468 	eh = mtod(m, struct ether_header *);
469 
470 	len = ntohs(eh->ether_type);
471 	if (len < sizeof(tpdu))
472 		goto out;
473 
474 	m_adj(m, ETHER_HDR_LEN);
475 
476 	if (m->m_pkthdr.len > len)
477 		m_adj(m, len - m->m_pkthdr.len);
478 	if (m->m_len < sizeof(tpdu) &&
479 	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
480 		goto out;
481 
482 	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
483 
484 	/* basic packet checks */
485 	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
486 	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
487 	    tpdu.tbu_ctl != LLC_UI)
488 		goto out;
489 	if (tpdu.tbu_protoid != BSTP_PROTO_ID)
490 		goto out;
491 
492 	/*
493 	 * We can treat later versions of the PDU as the same as the maximum
494 	 * version we implement. All additional parameters/flags are ignored.
495 	 */
496 	if (tpdu.tbu_protover > BSTP_PROTO_MAX)
497 		tpdu.tbu_protover = BSTP_PROTO_MAX;
498 
499 	if (tpdu.tbu_protover != bp->bp_protover) {
500 		/*
501 		 * Wait for the migration delay timer to expire before changing
502 		 * protocol version to avoid flip-flops.
503 		 */
504 		if (bp->bp_flags & BSTP_PORT_CANMIGRATE)
505 			bstp_set_port_proto(bp, tpdu.tbu_protover);
506 		else
507 			goto out;
508 	}
509 
510 	/* Clear operedge upon receiving a PDU on the port */
511 	bp->bp_operedge = 0;
512 	bstp_timer_start(&bp->bp_edge_delay_timer,
513 	    BSTP_DEFAULT_MIGRATE_DELAY);
514 
515 	switch (tpdu.tbu_protover) {
516 		case BSTP_PROTO_STP:
517 			bstp_received_stp(bs, bp, &m, &tpdu);
518 			break;
519 
520 		case BSTP_PROTO_RSTP:
521 			bstp_received_rstp(bs, bp, &m, &tpdu);
522 			break;
523 	}
524 out:
525 	BSTP_UNLOCK(bs);
526 	if (m)
527 		m_freem(m);
528 	return (NULL);
529 }
530 
531 static void
532 bstp_received_stp(struct bstp_state *bs, struct bstp_port *bp,
533     struct mbuf **mp, struct bstp_tbpdu *tpdu)
534 {
535 	struct bstp_cbpdu cpdu;
536 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
537 	struct bstp_tcn_unit tu;
538 
539 	switch (tpdu->tbu_bpdutype) {
540 	case BSTP_MSGTYPE_TCN:
541 		tu.tu_message_type = tpdu->tbu_bpdutype;
542 		bstp_received_tcn(bs, bp, &tu);
543 		break;
544 	case BSTP_MSGTYPE_CFG:
545 		if ((*mp)->m_len < BSTP_BPDU_STP_LEN &&
546 		    (*mp = m_pullup(*mp, BSTP_BPDU_STP_LEN)) == NULL)
547 			return;
548 		memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_STP_LEN);
549 
550 		bstp_decode_bpdu(bp, &cpdu, cu);
551 		bstp_received_bpdu(bs, bp, cu);
552 		break;
553 	}
554 }
555 
556 static void
557 bstp_received_rstp(struct bstp_state *bs, struct bstp_port *bp,
558     struct mbuf **mp, struct bstp_tbpdu *tpdu)
559 {
560 	struct bstp_cbpdu cpdu;
561 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
562 
563 	if (tpdu->tbu_bpdutype != BSTP_MSGTYPE_RSTP)
564 		return;
565 
566 	if ((*mp)->m_len < BSTP_BPDU_RSTP_LEN &&
567 	    (*mp = m_pullup(*mp, BSTP_BPDU_RSTP_LEN)) == NULL)
568 		return;
569 	memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_RSTP_LEN);
570 
571 	bstp_decode_bpdu(bp, &cpdu, cu);
572 	bstp_received_bpdu(bs, bp, cu);
573 }
574 
575 static void
576 bstp_received_tcn(struct bstp_state *bs, struct bstp_port *bp,
577     struct bstp_tcn_unit *tcn)
578 {
579 	bp->bp_rcvdtcn = 1;
580 	bstp_update_tc(bp);
581 }
582 
583 static void
584 bstp_received_bpdu(struct bstp_state *bs, struct bstp_port *bp,
585     struct bstp_config_unit *cu)
586 {
587 	int type;
588 
589 	BSTP_LOCK_ASSERT(bs);
590 
591 	/* We need to have transitioned to INFO_MINE before proceeding */
592 	switch (bp->bp_infois) {
593 		case BSTP_INFO_DISABLED:
594 		case BSTP_INFO_AGED:
595 			return;
596 	}
597 
598 	type = bstp_pdu_rcvtype(bp, cu);
599 
600 	switch (type) {
601 		case BSTP_PDU_SUPERIOR:
602 			bs->bs_allsynced = 0;
603 			bp->bp_agreed = 0;
604 			bp->bp_proposing = 0;
605 
606 			if (cu->cu_proposal && cu->cu_forwarding == 0)
607 				bp->bp_proposed = 1;
608 			if (cu->cu_topology_change)
609 				bp->bp_rcvdtc = 1;
610 			if (cu->cu_topology_change_ack)
611 				bp->bp_rcvdtca = 1;
612 
613 			if (bp->bp_agree &&
614 			    !bstp_pdu_bettersame(bp, BSTP_INFO_RECEIVED))
615 				bp->bp_agree = 0;
616 
617 			/* copy the received priority and timers to the port */
618 			bp->bp_port_pv = cu->cu_pv;
619 			bp->bp_port_msg_age = cu->cu_message_age;
620 			bp->bp_port_max_age = cu->cu_max_age;
621 			bp->bp_port_fdelay = cu->cu_forward_delay;
622 			bp->bp_port_htime =
623 				(cu->cu_hello_time > BSTP_MIN_HELLO_TIME ?
624 				 cu->cu_hello_time : BSTP_MIN_HELLO_TIME);
625 
626 			/* set expiry for the new info */
627 			bstp_set_timer_msgage(bp);
628 
629 			bp->bp_infois = BSTP_INFO_RECEIVED;
630 			bstp_assign_roles(bs);
631 			break;
632 
633 		case BSTP_PDU_REPEATED:
634 			if (cu->cu_proposal && cu->cu_forwarding == 0)
635 				bp->bp_proposed = 1;
636 			if (cu->cu_topology_change)
637 				bp->bp_rcvdtc = 1;
638 			if (cu->cu_topology_change_ack)
639 				bp->bp_rcvdtca = 1;
640 
641 			/* rearm the age timer */
642 			bstp_set_timer_msgage(bp);
643 			break;
644 
645 		case BSTP_PDU_INFERIOR:
646 			if (cu->cu_learning) {
647 				bp->bp_agreed = 1;
648 				bp->bp_proposing = 0;
649 			}
650 			break;
651 
652 		case BSTP_PDU_INFERIORALT:
653 			/*
654 			 * only point to point links are allowed fast
655 			 * transitions to forwarding.
656 			 */
657 			if (cu->cu_agree && bp->bp_ptp_link) {
658 				bp->bp_agreed = 1;
659 				bp->bp_proposing = 0;
660 			} else
661 				bp->bp_agreed = 0;
662 
663 			if (cu->cu_topology_change)
664 				bp->bp_rcvdtc = 1;
665 			if (cu->cu_topology_change_ack)
666 				bp->bp_rcvdtca = 1;
667 			break;
668 
669 		case BSTP_PDU_OTHER:
670 			return;	/* do nothing */
671 	}
672 	/* update the state machines with the new data */
673 	bstp_update_state(bs, bp);
674 }
675 
676 static int
677 bstp_pdu_rcvtype(struct bstp_port *bp, struct bstp_config_unit *cu)
678 {
679 	int type;
680 
681 	/* default return type */
682 	type = BSTP_PDU_OTHER;
683 
684 	switch (cu->cu_role) {
685 	case BSTP_ROLE_DESIGNATED:
686 		if (bstp_info_superior(&bp->bp_port_pv, &cu->cu_pv))
687 			/* bpdu priority is superior */
688 			type = BSTP_PDU_SUPERIOR;
689 		else if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) ==
690 		    INFO_SAME) {
691 			if (bp->bp_port_msg_age != cu->cu_message_age ||
692 			    bp->bp_port_max_age != cu->cu_max_age ||
693 			    bp->bp_port_fdelay != cu->cu_forward_delay ||
694 			    bp->bp_port_htime != cu->cu_hello_time)
695 				/* bpdu priority is equal and timers differ */
696 				type = BSTP_PDU_SUPERIOR;
697 			else
698 				/* bpdu is equal */
699 				type = BSTP_PDU_REPEATED;
700 		} else
701 			/* bpdu priority is worse */
702 			type = BSTP_PDU_INFERIOR;
703 
704 		break;
705 
706 	case BSTP_ROLE_ROOT:
707 	case BSTP_ROLE_ALTERNATE:
708 	case BSTP_ROLE_BACKUP:
709 		if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) <= INFO_SAME)
710 			/*
711 			 * not a designated port and priority is the same or
712 			 * worse
713 			 */
714 			type = BSTP_PDU_INFERIORALT;
715 		break;
716 	}
717 
718 	return (type);
719 }
720 
721 static int
722 bstp_pdu_bettersame(struct bstp_port *bp, int newinfo)
723 {
724 	if (newinfo == BSTP_INFO_RECEIVED &&
725 	    bp->bp_infois == BSTP_INFO_RECEIVED &&
726 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_msg_cu.cu_pv) >= INFO_SAME)
727 		return (1);
728 
729 	if (newinfo == BSTP_INFO_MINE &&
730 	    bp->bp_infois == BSTP_INFO_MINE &&
731 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_desg_pv) >= INFO_SAME)
732 		return (1);
733 
734 	return (0);
735 }
736 
737 static int
738 bstp_info_cmp(struct bstp_pri_vector *pv,
739     struct bstp_pri_vector *cpv)
740 {
741 	if (cpv->pv_root_id < pv->pv_root_id)
742 		return (INFO_BETTER);
743 	if (cpv->pv_root_id > pv->pv_root_id)
744 		return (INFO_WORSE);
745 
746 	if (cpv->pv_cost < pv->pv_cost)
747 		return (INFO_BETTER);
748 	if (cpv->pv_cost > pv->pv_cost)
749 		return (INFO_WORSE);
750 
751 	if (cpv->pv_dbridge_id < pv->pv_dbridge_id)
752 		return (INFO_BETTER);
753 	if (cpv->pv_dbridge_id > pv->pv_dbridge_id)
754 		return (INFO_WORSE);
755 
756 	if (cpv->pv_dport_id < pv->pv_dport_id)
757 		return (INFO_BETTER);
758 	if (cpv->pv_dport_id > pv->pv_dport_id)
759 		return (INFO_WORSE);
760 
761 	return (INFO_SAME);
762 }
763 
764 /*
765  * This message priority vector is superior to the port priority vector and
766  * will replace it if, and only if, the message priority vector is better than
767  * the port priority vector, or the message has been transmitted from the same
768  * designated bridge and designated port as the port priority vector.
769  */
770 static int
771 bstp_info_superior(struct bstp_pri_vector *pv,
772     struct bstp_pri_vector *cpv)
773 {
774 	if (bstp_info_cmp(pv, cpv) == INFO_BETTER ||
775 	    (bstp_same_bridgeid(pv->pv_dbridge_id, cpv->pv_dbridge_id) &&
776 	    (cpv->pv_dport_id & 0xfff) == (pv->pv_dport_id & 0xfff)))
777 		return (1);
778 	return (0);
779 }
780 
781 static void
782 bstp_assign_roles(struct bstp_state *bs)
783 {
784 	struct bstp_port *bp, *rbp = NULL;
785 	struct bstp_pri_vector pv;
786 
787 	/* default to our priority vector */
788 	bs->bs_root_pv = bs->bs_bridge_pv;
789 	bs->bs_root_msg_age = 0;
790 	bs->bs_root_max_age = bs->bs_bridge_max_age;
791 	bs->bs_root_fdelay = bs->bs_bridge_fdelay;
792 	bs->bs_root_htime = bs->bs_bridge_htime;
793 	bs->bs_root_port = NULL;
794 
795 	/* check if any recieved info supersedes us */
796 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
797 		if (bp->bp_infois != BSTP_INFO_RECEIVED)
798 			continue;
799 
800 		pv = bp->bp_port_pv;
801 		pv.pv_cost += bp->bp_path_cost;
802 
803 		/*
804 		 * The root priority vector is the best of the set comprising
805 		 * the bridge priority vector plus all root path priority
806 		 * vectors whose bridge address is not equal to us.
807 		 */
808 		if (bstp_same_bridgeid(pv.pv_dbridge_id,
809 		    bs->bs_bridge_pv.pv_dbridge_id) == 0 &&
810 		    bstp_info_cmp(&bs->bs_root_pv, &pv) == INFO_BETTER) {
811 			/* the port vector replaces the root */
812 			bs->bs_root_pv = pv;
813 			bs->bs_root_msg_age = bp->bp_port_msg_age +
814 			    BSTP_MESSAGE_AGE_INCR;
815 			bs->bs_root_max_age = bp->bp_port_max_age;
816 			bs->bs_root_fdelay = bp->bp_port_fdelay;
817 			bs->bs_root_htime = bp->bp_port_htime;
818 			rbp = bp;
819 		}
820 	}
821 
822 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
823 		/* calculate the port designated vector */
824 		bp->bp_desg_pv.pv_root_id = bs->bs_root_pv.pv_root_id;
825 		bp->bp_desg_pv.pv_cost = bs->bs_root_pv.pv_cost;
826 		bp->bp_desg_pv.pv_dbridge_id = bs->bs_bridge_pv.pv_dbridge_id;
827 		bp->bp_desg_pv.pv_dport_id = bp->bp_port_id;
828 		bp->bp_desg_pv.pv_port_id = bp->bp_port_id;
829 
830 		/* calculate designated times */
831 		bp->bp_desg_msg_age = bs->bs_root_msg_age;
832 		bp->bp_desg_max_age = bs->bs_root_max_age;
833 		bp->bp_desg_fdelay = bs->bs_root_fdelay;
834 		bp->bp_desg_htime = bs->bs_bridge_htime;
835 
836 
837 		switch (bp->bp_infois) {
838 		case BSTP_INFO_DISABLED:
839 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
840 			break;
841 
842 		case BSTP_INFO_AGED:
843 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
844 			bstp_update_info(bp);
845 			break;
846 
847 		case BSTP_INFO_MINE:
848 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
849 			/* update the port info if stale */
850 			if (bstp_info_cmp(&bp->bp_port_pv,
851 			    &bp->bp_desg_pv) != INFO_SAME ||
852 			    (rbp != NULL &&
853 			    (bp->bp_port_msg_age != rbp->bp_port_msg_age ||
854 			    bp->bp_port_max_age != rbp->bp_port_max_age ||
855 			    bp->bp_port_fdelay != rbp->bp_port_fdelay ||
856 			    bp->bp_port_htime != rbp->bp_port_htime)))
857 				bstp_update_info(bp);
858 			break;
859 
860 		case BSTP_INFO_RECEIVED:
861 			if (bp == rbp) {
862 				/*
863 				 * root priority is derived from this
864 				 * port, make it the root port.
865 				 */
866 				bstp_set_port_role(bp, BSTP_ROLE_ROOT);
867 				bs->bs_root_port = bp;
868 			} else if (bstp_info_cmp(&bp->bp_port_pv,
869 				    &bp->bp_desg_pv) == INFO_BETTER) {
870 				/*
871 				 * the port priority is lower than the root
872 				 * port.
873 				 */
874 				bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
875 				bstp_update_info(bp);
876 			} else {
877 				if (bstp_same_bridgeid(
878 				    bp->bp_port_pv.pv_dbridge_id,
879 				    bs->bs_bridge_pv.pv_dbridge_id)) {
880 					/*
881 					 * the designated bridge refers to
882 					 * another port on this bridge.
883 					 */
884 					bstp_set_port_role(bp,
885 					    BSTP_ROLE_BACKUP);
886 				} else {
887 					/*
888 					 * the port is an inferior path to the
889 					 * root bridge.
890 					 */
891 					bstp_set_port_role(bp,
892 					    BSTP_ROLE_ALTERNATE);
893 				}
894 			}
895 			break;
896 		}
897 	}
898 }
899 
900 static void
901 bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
902 {
903 	struct bstp_port *bp2;
904 	int synced;
905 
906 	BSTP_LOCK_ASSERT(bs);
907 
908 	/* check if all the ports have syncronised again */
909 	if (!bs->bs_allsynced) {
910 		synced = 1;
911 		LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
912 			if (!(bp2->bp_synced ||
913 			     bp2->bp_role == BSTP_ROLE_ROOT)) {
914 				synced = 0;
915 				break;
916 			}
917 		}
918 		bs->bs_allsynced = synced;
919 	}
920 
921 	bstp_update_roles(bs, bp);
922 	bstp_update_tc(bp);
923 }
924 
925 static void
926 bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
927 {
928 	switch (bp->bp_role) {
929 	case BSTP_ROLE_DISABLED:
930 		/* Clear any flags if set */
931 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
932 			bp->bp_sync = 0;
933 			bp->bp_synced = 1;
934 			bp->bp_reroot = 0;
935 		}
936 		break;
937 
938 	case BSTP_ROLE_ALTERNATE:
939 	case BSTP_ROLE_BACKUP:
940 		if ((bs->bs_allsynced && !bp->bp_agree) ||
941 		    (bp->bp_proposed && bp->bp_agree)) {
942 			bp->bp_proposed = 0;
943 			bp->bp_agree = 1;
944 			bp->bp_flags |= BSTP_PORT_NEWINFO;
945 			DPRINTF("%s -> ALTERNATE_AGREED\n",
946 			    bp->bp_ifp->if_xname);
947 		}
948 
949 		if (bp->bp_proposed && !bp->bp_agree) {
950 			bstp_set_all_sync(bs);
951 			bp->bp_proposed = 0;
952 			DPRINTF("%s -> ALTERNATE_PROPOSED\n",
953 			    bp->bp_ifp->if_xname);
954 		}
955 
956 		/* Clear any flags if set */
957 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
958 			bp->bp_sync = 0;
959 			bp->bp_synced = 1;
960 			bp->bp_reroot = 0;
961 			DPRINTF("%s -> ALTERNATE_PORT\n", bp->bp_ifp->if_xname);
962 		}
963 		break;
964 
965 	case BSTP_ROLE_ROOT:
966 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING && !bp->bp_reroot) {
967 			bstp_set_all_reroot(bs);
968 			DPRINTF("%s -> ROOT_REROOT\n", bp->bp_ifp->if_xname);
969 		}
970 
971 		if ((bs->bs_allsynced && !bp->bp_agree) ||
972 		    (bp->bp_proposed && bp->bp_agree)) {
973 			bp->bp_proposed = 0;
974 			bp->bp_sync = 0;
975 			bp->bp_agree = 1;
976 			bp->bp_flags |= BSTP_PORT_NEWINFO;
977 			DPRINTF("%s -> ROOT_AGREED\n", bp->bp_ifp->if_xname);
978 		}
979 
980 		if (bp->bp_proposed && !bp->bp_agree) {
981 			bstp_set_all_sync(bs);
982 			bp->bp_proposed = 0;
983 			DPRINTF("%s -> ROOT_PROPOSED\n", bp->bp_ifp->if_xname);
984 		}
985 
986 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
987 		    (bp->bp_forward_delay_timer.active == 0 ||
988 		    (bstp_rerooted(bs, bp) &&
989 		    bp->bp_recent_backup_timer.active == 0 &&
990 		    bp->bp_protover == BSTP_PROTO_RSTP))) {
991 			switch (bp->bp_state) {
992 			case BSTP_IFSTATE_DISCARDING:
993 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
994 				break;
995 			case BSTP_IFSTATE_LEARNING:
996 				bstp_set_port_state(bp,
997 				    BSTP_IFSTATE_FORWARDING);
998 				break;
999 			}
1000 		}
1001 
1002 		if (bp->bp_state == BSTP_IFSTATE_FORWARDING && bp->bp_reroot) {
1003 			bp->bp_reroot = 0;
1004 			DPRINTF("%s -> ROOT_REROOTED\n", bp->bp_ifp->if_xname);
1005 		}
1006 		break;
1007 
1008 	case BSTP_ROLE_DESIGNATED:
1009 		if (bp->bp_recent_root_timer.active == 0 && bp->bp_reroot) {
1010 			bp->bp_reroot = 0;
1011 			DPRINTF("%s -> DESIGNATED_RETIRED\n",
1012 			    bp->bp_ifp->if_xname);
1013 		}
1014 
1015 		if ((bp->bp_state == BSTP_IFSTATE_DISCARDING &&
1016 		    !bp->bp_synced) || (bp->bp_agreed && !bp->bp_synced) ||
1017 		    (bp->bp_operedge && !bp->bp_synced) ||
1018 		    (bp->bp_sync && bp->bp_synced)) {
1019 			bstp_timer_stop(&bp->bp_recent_root_timer);
1020 			bp->bp_synced = 1;
1021 			bp->bp_sync = 0;
1022 			DPRINTF("%s -> DESIGNATED_SYNCED\n",
1023 			    bp->bp_ifp->if_xname);
1024 		}
1025 
1026 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1027 		    !bp->bp_agreed && !bp->bp_proposing &&
1028 		    !bp->bp_operedge) {
1029 			bp->bp_proposing = 1;
1030 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1031 			bstp_timer_start(&bp->bp_edge_delay_timer,
1032 			    (bp->bp_ptp_link ? BSTP_DEFAULT_MIGRATE_DELAY :
1033 			     bp->bp_desg_max_age));
1034 			DPRINTF("%s -> DESIGNATED_PROPOSE\n",
1035 			    bp->bp_ifp->if_xname);
1036 		}
1037 
1038 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1039 		    (bp->bp_forward_delay_timer.active == 0 || bp->bp_agreed ||
1040 		    bp->bp_operedge) &&
1041 		    (bp->bp_recent_root_timer.active == 0 || !bp->bp_reroot) &&
1042 		    !bp->bp_sync) {
1043 			if (bp->bp_agreed)
1044 				DPRINTF("%s -> AGREED\n", bp->bp_ifp->if_xname);
1045 			/*
1046 			 * If agreed|operedge then go straight to forwarding,
1047 			 * otherwise follow discard -> learn -> forward.
1048 			 */
1049 			if (bp->bp_agreed || bp->bp_operedge ||
1050 			    bp->bp_state == BSTP_IFSTATE_LEARNING) {
1051 				bstp_set_port_state(bp,
1052 				    BSTP_IFSTATE_FORWARDING);
1053 				bp->bp_agreed = bp->bp_protover;
1054 			} else if (bp->bp_state == BSTP_IFSTATE_DISCARDING)
1055 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
1056 		}
1057 
1058 		if (((bp->bp_sync && !bp->bp_synced) ||
1059 		    (bp->bp_reroot && bp->bp_recent_root_timer.active) ||
1060 		    (bp->bp_flags & BSTP_PORT_DISPUTED)) && !bp->bp_operedge &&
1061 		    bp->bp_state != BSTP_IFSTATE_DISCARDING) {
1062 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1063 			bp->bp_flags &= ~BSTP_PORT_DISPUTED;
1064 			bstp_timer_start(&bp->bp_forward_delay_timer,
1065 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1066 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1067 			DPRINTF("%s -> DESIGNATED_DISCARD\n",
1068 			    bp->bp_ifp->if_xname);
1069 		}
1070 		break;
1071 	}
1072 
1073 	if (bp->bp_flags & BSTP_PORT_NEWINFO)
1074 		bstp_transmit(bs, bp);
1075 }
1076 
1077 static void
1078 bstp_update_tc(struct bstp_port *bp)
1079 {
1080 	switch (bp->bp_tcstate) {
1081 		case BSTP_TCSTATE_ACTIVE:
1082 			if ((bp->bp_role != BSTP_ROLE_DESIGNATED &&
1083 			    bp->bp_role != BSTP_ROLE_ROOT) || bp->bp_operedge)
1084 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1085 
1086 			if (bp->bp_rcvdtcn)
1087 				bstp_set_port_tc(bp, BSTP_TCSTATE_TCN);
1088 			if (bp->bp_rcvdtc)
1089 				bstp_set_port_tc(bp, BSTP_TCSTATE_TC);
1090 
1091 			if (bp->bp_tc_prop && !bp->bp_operedge)
1092 				bstp_set_port_tc(bp, BSTP_TCSTATE_PROPAG);
1093 
1094 			if (bp->bp_rcvdtca)
1095 				bstp_set_port_tc(bp, BSTP_TCSTATE_ACK);
1096 			break;
1097 
1098 		case BSTP_TCSTATE_INACTIVE:
1099 			if ((bp->bp_state == BSTP_IFSTATE_LEARNING ||
1100 			    bp->bp_state == BSTP_IFSTATE_FORWARDING) &&
1101 			    bp->bp_fdbflush == 0)
1102 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1103 			break;
1104 
1105 		case BSTP_TCSTATE_LEARNING:
1106 			if (bp->bp_rcvdtc || bp->bp_rcvdtcn || bp->bp_rcvdtca ||
1107 			    bp->bp_tc_prop)
1108 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1109 			else if (bp->bp_role != BSTP_ROLE_DESIGNATED &&
1110 				 bp->bp_role != BSTP_ROLE_ROOT &&
1111 				 bp->bp_state == BSTP_IFSTATE_DISCARDING)
1112 				bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1113 
1114 			if ((bp->bp_role == BSTP_ROLE_DESIGNATED ||
1115 			    bp->bp_role == BSTP_ROLE_ROOT) &&
1116 			    bp->bp_state == BSTP_IFSTATE_FORWARDING &&
1117 			    !bp->bp_operedge)
1118 				bstp_set_port_tc(bp, BSTP_TCSTATE_DETECTED);
1119 			break;
1120 
1121 		/* these are transient states and go straight back to ACTIVE */
1122 		case BSTP_TCSTATE_DETECTED:
1123 		case BSTP_TCSTATE_TCN:
1124 		case BSTP_TCSTATE_TC:
1125 		case BSTP_TCSTATE_PROPAG:
1126 		case BSTP_TCSTATE_ACK:
1127 			DPRINTF("Invalid TC state for %s\n",
1128 			    bp->bp_ifp->if_xname);
1129 			break;
1130 	}
1131 
1132 }
1133 
1134 static void
1135 bstp_update_info(struct bstp_port *bp)
1136 {
1137 	struct bstp_state *bs = bp->bp_bs;
1138 
1139 	bp->bp_proposing = 0;
1140 	bp->bp_proposed = 0;
1141 
1142 	if (bp->bp_agreed && !bstp_pdu_bettersame(bp, BSTP_INFO_MINE))
1143 		bp->bp_agreed = 0;
1144 
1145 	if (bp->bp_synced && !bp->bp_agreed) {
1146 		bp->bp_synced = 0;
1147 		bs->bs_allsynced = 0;
1148 	}
1149 
1150 	/* copy the designated pv to the port */
1151 	bp->bp_port_pv = bp->bp_desg_pv;
1152 	bp->bp_port_msg_age = bp->bp_desg_msg_age;
1153 	bp->bp_port_max_age = bp->bp_desg_max_age;
1154 	bp->bp_port_fdelay = bp->bp_desg_fdelay;
1155 	bp->bp_port_htime = bp->bp_desg_htime;
1156 	bp->bp_infois = BSTP_INFO_MINE;
1157 
1158 	/* Set transmit flag but do not immediately send */
1159 	bp->bp_flags |= BSTP_PORT_NEWINFO;
1160 }
1161 
1162 /* set tcprop on every port other than the caller */
1163 static void
1164 bstp_set_other_tcprop(struct bstp_port *bp)
1165 {
1166 	struct bstp_state *bs = bp->bp_bs;
1167 	struct bstp_port *bp2;
1168 
1169 	BSTP_LOCK_ASSERT(bs);
1170 
1171 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1172 		if (bp2 == bp)
1173 			continue;
1174 		bp2->bp_tc_prop = 1;
1175 	}
1176 }
1177 
1178 static void
1179 bstp_set_all_reroot(struct bstp_state *bs)
1180 {
1181 	struct bstp_port *bp;
1182 
1183 	BSTP_LOCK_ASSERT(bs);
1184 
1185 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1186 		bp->bp_reroot = 1;
1187 }
1188 
1189 static void
1190 bstp_set_all_sync(struct bstp_state *bs)
1191 {
1192 	struct bstp_port *bp;
1193 
1194 	BSTP_LOCK_ASSERT(bs);
1195 
1196 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1197 		bp->bp_sync = 1;
1198 		bp->bp_synced = 0;	/* Not explicit in spec */
1199 	}
1200 
1201 	bs->bs_allsynced = 0;
1202 }
1203 
1204 static void
1205 bstp_set_port_state(struct bstp_port *bp, int state)
1206 {
1207 	if (bp->bp_state == state)
1208 		return;
1209 
1210 	bp->bp_state = state;
1211 
1212 	switch (bp->bp_state) {
1213 		case BSTP_IFSTATE_DISCARDING:
1214 			DPRINTF("state changed to DISCARDING on %s\n",
1215 			    bp->bp_ifp->if_xname);
1216 			break;
1217 
1218 		case BSTP_IFSTATE_LEARNING:
1219 			DPRINTF("state changed to LEARNING on %s\n",
1220 			    bp->bp_ifp->if_xname);
1221 
1222 			bstp_timer_start(&bp->bp_forward_delay_timer,
1223 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1224 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1225 			break;
1226 
1227 		case BSTP_IFSTATE_FORWARDING:
1228 			DPRINTF("state changed to FORWARDING on %s\n",
1229 			    bp->bp_ifp->if_xname);
1230 
1231 			bstp_timer_stop(&bp->bp_forward_delay_timer);
1232 			/* Record that we enabled forwarding */
1233 			bp->bp_forward_transitions++;
1234 			break;
1235 	}
1236 
1237 	/* notify the parent bridge */
1238 	taskqueue_enqueue(taskqueue_swi, &bp->bp_statetask);
1239 }
1240 
1241 static void
1242 bstp_set_port_role(struct bstp_port *bp, int role)
1243 {
1244 	struct bstp_state *bs = bp->bp_bs;
1245 
1246 	if (bp->bp_role == role)
1247 		return;
1248 
1249 	/* perform pre-change tasks */
1250 	switch (bp->bp_role) {
1251 		case BSTP_ROLE_DISABLED:
1252 			bstp_timer_start(&bp->bp_forward_delay_timer,
1253 			    bp->bp_desg_max_age);
1254 			break;
1255 
1256 		case BSTP_ROLE_BACKUP:
1257 			bstp_timer_start(&bp->bp_recent_backup_timer,
1258 			    bp->bp_desg_htime * 2);
1259 			/* fall through */
1260 		case BSTP_ROLE_ALTERNATE:
1261 			bstp_timer_start(&bp->bp_forward_delay_timer,
1262 			    bp->bp_desg_fdelay);
1263 			bp->bp_sync = 0;
1264 			bp->bp_synced = 1;
1265 			bp->bp_reroot = 0;
1266 			break;
1267 
1268 		case BSTP_ROLE_ROOT:
1269 			bstp_timer_start(&bp->bp_recent_root_timer,
1270 			    BSTP_DEFAULT_FORWARD_DELAY);
1271 			break;
1272 	}
1273 
1274 	bp->bp_role = role;
1275 	/* clear values not carried between roles */
1276 	bp->bp_proposing = 0;
1277 	bs->bs_allsynced = 0;
1278 
1279 	/* initialise the new role */
1280 	switch (bp->bp_role) {
1281 		case BSTP_ROLE_DISABLED:
1282 		case BSTP_ROLE_ALTERNATE:
1283 		case BSTP_ROLE_BACKUP:
1284 			DPRINTF("%s role -> ALT/BACK/DISABLED\n",
1285 			    bp->bp_ifp->if_xname);
1286 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1287 			bstp_timer_stop(&bp->bp_recent_root_timer);
1288 			bstp_timer_latch(&bp->bp_forward_delay_timer);
1289 			bp->bp_sync = 0;
1290 			bp->bp_synced = 1;
1291 			bp->bp_reroot = 0;
1292 			break;
1293 
1294 		case BSTP_ROLE_ROOT:
1295 			DPRINTF("%s role -> ROOT\n",
1296 			    bp->bp_ifp->if_xname);
1297 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1298 			bstp_timer_latch(&bp->bp_recent_root_timer);
1299 			bp->bp_proposing = 0;
1300 			break;
1301 
1302 		case BSTP_ROLE_DESIGNATED:
1303 			DPRINTF("%s role -> DESIGNATED\n",
1304 			    bp->bp_ifp->if_xname);
1305 			bstp_timer_start(&bp->bp_hello_timer,
1306 			    bp->bp_desg_htime);
1307 			bp->bp_agree = 0;
1308 			break;
1309 	}
1310 
1311 	/* let the TC state know that the role changed */
1312 	bstp_update_tc(bp);
1313 }
1314 
1315 static void
1316 bstp_set_port_proto(struct bstp_port *bp, int proto)
1317 {
1318 	struct bstp_state *bs = bp->bp_bs;
1319 
1320 	/* supported protocol versions */
1321 	switch (proto) {
1322 		case BSTP_PROTO_STP:
1323 			/* we can downgrade protocols only */
1324 			bstp_timer_stop(&bp->bp_migrate_delay_timer);
1325 			/* clear unsupported features */
1326 			bp->bp_operedge = 0;
1327 			/* STP compat mode only uses 16 bits of the 32 */
1328 			if (bp->bp_path_cost > 65535)
1329 				bp->bp_path_cost = 65535;
1330 			break;
1331 
1332 		case BSTP_PROTO_RSTP:
1333 			bstp_timer_start(&bp->bp_migrate_delay_timer,
1334 			    bs->bs_migration_delay);
1335 			break;
1336 
1337 		default:
1338 			DPRINTF("Unsupported STP version %d\n", proto);
1339 			return;
1340 	}
1341 
1342 	bp->bp_protover = proto;
1343 	bp->bp_flags &= ~BSTP_PORT_CANMIGRATE;
1344 }
1345 
1346 static void
1347 bstp_set_port_tc(struct bstp_port *bp, int state)
1348 {
1349 	struct bstp_state *bs = bp->bp_bs;
1350 
1351 	bp->bp_tcstate = state;
1352 
1353 	/* initialise the new state */
1354 	switch (bp->bp_tcstate) {
1355 		case BSTP_TCSTATE_ACTIVE:
1356 			DPRINTF("%s -> TC_ACTIVE\n", bp->bp_ifp->if_xname);
1357 			/* nothing to do */
1358 			break;
1359 
1360 		case BSTP_TCSTATE_INACTIVE:
1361 			bstp_timer_stop(&bp->bp_tc_timer);
1362 			/* flush routes on the parent bridge */
1363 			bp->bp_fdbflush = 1;
1364 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1365 			bp->bp_tc_ack = 0;
1366 			DPRINTF("%s -> TC_INACTIVE\n", bp->bp_ifp->if_xname);
1367 			break;
1368 
1369 		case BSTP_TCSTATE_LEARNING:
1370 			bp->bp_rcvdtc = 0;
1371 			bp->bp_rcvdtcn = 0;
1372 			bp->bp_rcvdtca = 0;
1373 			bp->bp_tc_prop = 0;
1374 			DPRINTF("%s -> TC_LEARNING\n", bp->bp_ifp->if_xname);
1375 			break;
1376 
1377 		case BSTP_TCSTATE_DETECTED:
1378 			bstp_set_timer_tc(bp);
1379 			bstp_set_other_tcprop(bp);
1380 			/* send out notification */
1381 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1382 			bstp_transmit(bs, bp);
1383 			getmicrotime(&bs->bs_last_tc_time);
1384 			DPRINTF("%s -> TC_DETECTED\n", bp->bp_ifp->if_xname);
1385 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1386 			break;
1387 
1388 		case BSTP_TCSTATE_TCN:
1389 			bstp_set_timer_tc(bp);
1390 			DPRINTF("%s -> TC_TCN\n", bp->bp_ifp->if_xname);
1391 			/* fall through */
1392 		case BSTP_TCSTATE_TC:
1393 			bp->bp_rcvdtc = 0;
1394 			bp->bp_rcvdtcn = 0;
1395 			if (bp->bp_role == BSTP_ROLE_DESIGNATED)
1396 				bp->bp_tc_ack = 1;
1397 
1398 			bstp_set_other_tcprop(bp);
1399 			DPRINTF("%s -> TC_TC\n", bp->bp_ifp->if_xname);
1400 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1401 			break;
1402 
1403 		case BSTP_TCSTATE_PROPAG:
1404 			/* flush routes on the parent bridge */
1405 			bp->bp_fdbflush = 1;
1406 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1407 			bp->bp_tc_prop = 0;
1408 			bstp_set_timer_tc(bp);
1409 			DPRINTF("%s -> TC_PROPAG\n", bp->bp_ifp->if_xname);
1410 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1411 			break;
1412 
1413 		case BSTP_TCSTATE_ACK:
1414 			bstp_timer_stop(&bp->bp_tc_timer);
1415 			bp->bp_rcvdtca = 0;
1416 			DPRINTF("%s -> TC_ACK\n", bp->bp_ifp->if_xname);
1417 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1418 			break;
1419 	}
1420 }
1421 
1422 static void
1423 bstp_set_timer_tc(struct bstp_port *bp)
1424 {
1425 	struct bstp_state *bs = bp->bp_bs;
1426 
1427 	if (bp->bp_tc_timer.active)
1428 		return;
1429 
1430 	switch (bp->bp_protover) {
1431 		case BSTP_PROTO_RSTP:
1432 			bstp_timer_start(&bp->bp_tc_timer,
1433 			    bp->bp_desg_htime + BSTP_TICK_VAL);
1434 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1435 			break;
1436 
1437 		case BSTP_PROTO_STP:
1438 			bstp_timer_start(&bp->bp_tc_timer,
1439 			    bs->bs_root_max_age + bs->bs_root_fdelay);
1440 			break;
1441 	}
1442 }
1443 
1444 static void
1445 bstp_set_timer_msgage(struct bstp_port *bp)
1446 {
1447 	if (bp->bp_port_msg_age + BSTP_MESSAGE_AGE_INCR <=
1448 	    bp->bp_port_max_age) {
1449 		bstp_timer_start(&bp->bp_message_age_timer,
1450 		    bp->bp_port_htime * 3);
1451 	} else
1452 		/* expires immediately */
1453 		bstp_timer_start(&bp->bp_message_age_timer, 0);
1454 }
1455 
1456 static int
1457 bstp_rerooted(struct bstp_state *bs, struct bstp_port *bp)
1458 {
1459 	struct bstp_port *bp2;
1460 	int rr_set = 0;
1461 
1462 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1463 		if (bp2 == bp)
1464 			continue;
1465 		if (bp2->bp_recent_root_timer.active) {
1466 			rr_set = 1;
1467 			break;
1468 		}
1469 	}
1470 	return (!rr_set);
1471 }
1472 
1473 int
1474 bstp_set_htime(struct bstp_state *bs, int t)
1475 {
1476 	/* convert seconds to ticks */
1477 	t *=  BSTP_TICK_VAL;
1478 
1479 	/* value can only be changed in leagacy stp mode */
1480 	if (bs->bs_protover != BSTP_PROTO_STP)
1481 		return (EPERM);
1482 
1483 	if (t < BSTP_MIN_HELLO_TIME || t > BSTP_MAX_HELLO_TIME)
1484 		return (EINVAL);
1485 
1486 	BSTP_LOCK(bs);
1487 	bs->bs_bridge_htime = t;
1488 	bstp_reinit(bs);
1489 	BSTP_UNLOCK(bs);
1490 	return (0);
1491 }
1492 
1493 int
1494 bstp_set_fdelay(struct bstp_state *bs, int t)
1495 {
1496 	/* convert seconds to ticks */
1497 	t *= BSTP_TICK_VAL;
1498 
1499 	if (t < BSTP_MIN_FORWARD_DELAY || t > BSTP_MAX_FORWARD_DELAY)
1500 		return (EINVAL);
1501 
1502 	BSTP_LOCK(bs);
1503 	bs->bs_bridge_fdelay = t;
1504 	bstp_reinit(bs);
1505 	BSTP_UNLOCK(bs);
1506 	return (0);
1507 }
1508 
1509 int
1510 bstp_set_maxage(struct bstp_state *bs, int t)
1511 {
1512 	/* convert seconds to ticks */
1513 	t *= BSTP_TICK_VAL;
1514 
1515 	if (t < BSTP_MIN_MAX_AGE || t > BSTP_MAX_MAX_AGE)
1516 		return (EINVAL);
1517 
1518 	BSTP_LOCK(bs);
1519 	bs->bs_bridge_max_age = t;
1520 	bstp_reinit(bs);
1521 	BSTP_UNLOCK(bs);
1522 	return (0);
1523 }
1524 
1525 int
1526 bstp_set_holdcount(struct bstp_state *bs, int count)
1527 {
1528 	struct bstp_port *bp;
1529 
1530 	if (count < BSTP_MIN_HOLD_COUNT ||
1531 	    count > BSTP_MAX_HOLD_COUNT)
1532 		return (EINVAL);
1533 
1534 	BSTP_LOCK(bs);
1535 	bs->bs_txholdcount = count;
1536 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1537 		bp->bp_txcount = 0;
1538 	BSTP_UNLOCK(bs);
1539 	return (0);
1540 }
1541 
1542 int
1543 bstp_set_protocol(struct bstp_state *bs, int proto)
1544 {
1545 	struct bstp_port *bp;
1546 
1547 	switch (proto) {
1548 		/* Supported protocol versions */
1549 		case BSTP_PROTO_STP:
1550 		case BSTP_PROTO_RSTP:
1551 			break;
1552 
1553 		default:
1554 			return (EINVAL);
1555 	}
1556 
1557 	BSTP_LOCK(bs);
1558 	bs->bs_protover = proto;
1559 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
1560 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1561 		/* reinit state */
1562 		bp->bp_infois = BSTP_INFO_DISABLED;
1563 		bp->bp_txcount = 0;
1564 		bstp_set_port_proto(bp, bs->bs_protover);
1565 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
1566 		bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1567 		bstp_timer_stop(&bp->bp_recent_backup_timer);
1568 	}
1569 	bstp_reinit(bs);
1570 	BSTP_UNLOCK(bs);
1571 	return (0);
1572 }
1573 
1574 int
1575 bstp_set_priority(struct bstp_state *bs, int pri)
1576 {
1577 	if (pri < 0 || pri > BSTP_MAX_PRIORITY)
1578 		return (EINVAL);
1579 
1580 	/* Limit to steps of 4096 */
1581 	pri -= pri % 4096;
1582 
1583 	BSTP_LOCK(bs);
1584 	bs->bs_bridge_priority = pri;
1585 	bstp_reinit(bs);
1586 	BSTP_UNLOCK(bs);
1587 	return (0);
1588 }
1589 
1590 int
1591 bstp_set_port_priority(struct bstp_port *bp, int pri)
1592 {
1593 	struct bstp_state *bs = bp->bp_bs;
1594 
1595 	if (pri < 0 || pri > BSTP_MAX_PORT_PRIORITY)
1596 		return (EINVAL);
1597 
1598 	/* Limit to steps of 16 */
1599 	pri -= pri % 16;
1600 
1601 	BSTP_LOCK(bs);
1602 	bp->bp_priority = pri;
1603 	bstp_reinit(bs);
1604 	BSTP_UNLOCK(bs);
1605 	return (0);
1606 }
1607 
1608 int
1609 bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
1610 {
1611 	struct bstp_state *bs = bp->bp_bs;
1612 
1613 	if (path_cost > BSTP_MAX_PATH_COST)
1614 		return (EINVAL);
1615 
1616 	/* STP compat mode only uses 16 bits of the 32 */
1617 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1618 		path_cost = 65535;
1619 
1620 	BSTP_LOCK(bs);
1621 
1622 	if (path_cost == 0) {	/* use auto */
1623 		bp->bp_flags &= ~BSTP_PORT_ADMCOST;
1624 		bp->bp_path_cost = bstp_calc_path_cost(bp);
1625 	} else {
1626 		bp->bp_path_cost = path_cost;
1627 		bp->bp_flags |= BSTP_PORT_ADMCOST;
1628 	}
1629 	bstp_reinit(bs);
1630 	BSTP_UNLOCK(bs);
1631 	return (0);
1632 }
1633 
1634 int
1635 bstp_set_edge(struct bstp_port *bp, int set)
1636 {
1637 	struct bstp_state *bs = bp->bp_bs;
1638 
1639 	BSTP_LOCK(bs);
1640 	if ((bp->bp_operedge = set) == 0)
1641 		bp->bp_flags &= ~BSTP_PORT_ADMEDGE;
1642 	else
1643 		bp->bp_flags |= BSTP_PORT_ADMEDGE;
1644 	BSTP_UNLOCK(bs);
1645 	return (0);
1646 }
1647 
1648 int
1649 bstp_set_autoedge(struct bstp_port *bp, int set)
1650 {
1651 	struct bstp_state *bs = bp->bp_bs;
1652 
1653 	BSTP_LOCK(bs);
1654 	if (set) {
1655 		bp->bp_flags |= BSTP_PORT_AUTOEDGE;
1656 		/* we may be able to transition straight to edge */
1657 		if (bp->bp_edge_delay_timer.active == 0)
1658 			bstp_edge_delay_expiry(bs, bp);
1659 	} else
1660 		bp->bp_flags &= ~BSTP_PORT_AUTOEDGE;
1661 	BSTP_UNLOCK(bs);
1662 	return (0);
1663 }
1664 
1665 int
1666 bstp_set_ptp(struct bstp_port *bp, int set)
1667 {
1668 	struct bstp_state *bs = bp->bp_bs;
1669 
1670 	BSTP_LOCK(bs);
1671 	bp->bp_ptp_link = set;
1672 	BSTP_UNLOCK(bs);
1673 	return (0);
1674 }
1675 
1676 int
1677 bstp_set_autoptp(struct bstp_port *bp, int set)
1678 {
1679 	struct bstp_state *bs = bp->bp_bs;
1680 
1681 	BSTP_LOCK(bs);
1682 	if (set) {
1683 		bp->bp_flags |= BSTP_PORT_AUTOPTP;
1684 		if (bp->bp_role != BSTP_ROLE_DISABLED)
1685 			bstp_ifupdstatus(bs, bp);
1686 	} else
1687 		bp->bp_flags &= ~BSTP_PORT_AUTOPTP;
1688 	BSTP_UNLOCK(bs);
1689 	return (0);
1690 }
1691 
1692 /*
1693  * Calculate the path cost according to the link speed.
1694  */
1695 static uint32_t
1696 bstp_calc_path_cost(struct bstp_port *bp)
1697 {
1698 	struct ifnet *ifp = bp->bp_ifp;
1699 	uint32_t path_cost;
1700 
1701 	/* If the priority has been manually set then retain the value */
1702 	if (bp->bp_flags & BSTP_PORT_ADMCOST)
1703 		return bp->bp_path_cost;
1704 
1705 	if (ifp->if_link_state == LINK_STATE_DOWN) {
1706 		/* Recalc when the link comes up again */
1707 		bp->bp_flags |= BSTP_PORT_PNDCOST;
1708 		return (BSTP_DEFAULT_PATH_COST);
1709 	}
1710 
1711 	if (ifp->if_baudrate < 1000)
1712 		return (BSTP_DEFAULT_PATH_COST);
1713 
1714  	/* formula from section 17.14, IEEE Std 802.1D-2004 */
1715 	path_cost = 20000000000ULL / (ifp->if_baudrate / 1000);
1716 
1717 	if (path_cost > BSTP_MAX_PATH_COST)
1718 		path_cost = BSTP_MAX_PATH_COST;
1719 
1720 	/* STP compat mode only uses 16 bits of the 32 */
1721 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1722 		path_cost = 65535;
1723 
1724 	return (path_cost);
1725 }
1726 
1727 /*
1728  * Notify the bridge that a port state has changed, we need to do this from a
1729  * taskqueue to avoid a LOR.
1730  */
1731 static void
1732 bstp_notify_state(void *arg, int pending)
1733 {
1734 	struct bstp_port *bp = (struct bstp_port *)arg;
1735 	struct bstp_state *bs = bp->bp_bs;
1736 
1737 	if (bp->bp_active == 1 && bs->bs_state_cb != NULL)
1738 		(*bs->bs_state_cb)(bp->bp_ifp, bp->bp_state);
1739 }
1740 
1741 /*
1742  * Flush the routes on the bridge port, we need to do this from a
1743  * taskqueue to avoid a LOR.
1744  */
1745 static void
1746 bstp_notify_rtage(void *arg, int pending)
1747 {
1748 	struct bstp_port *bp = (struct bstp_port *)arg;
1749 	struct bstp_state *bs = bp->bp_bs;
1750 	int age = 0;
1751 
1752 	BSTP_LOCK(bs);
1753 	switch (bp->bp_protover) {
1754 		case BSTP_PROTO_STP:
1755 			/* convert to seconds */
1756 			age = bp->bp_desg_fdelay / BSTP_TICK_VAL;
1757 			break;
1758 
1759 		case BSTP_PROTO_RSTP:
1760 			age = 0;
1761 			break;
1762 	}
1763 	BSTP_UNLOCK(bs);
1764 
1765 	if (bp->bp_active == 1 && bs->bs_rtage_cb != NULL)
1766 		(*bs->bs_rtage_cb)(bp->bp_ifp, age);
1767 
1768 	/* flush is complete */
1769 	BSTP_LOCK(bs);
1770 	bp->bp_fdbflush = 0;
1771 	BSTP_UNLOCK(bs);
1772 }
1773 
1774 void
1775 bstp_linkstate(struct ifnet *ifp, int state)
1776 {
1777 	struct bstp_state *bs;
1778 	struct bstp_port *bp;
1779 
1780 	/* search for the stp port */
1781 	mtx_lock(&bstp_list_mtx);
1782 	LIST_FOREACH(bs, &bstp_list, bs_list) {
1783 		BSTP_LOCK(bs);
1784 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1785 			if (bp->bp_ifp == ifp) {
1786 				bstp_ifupdstatus(bs, bp);
1787 				bstp_update_state(bs, bp);
1788 				/* it only exists once so return */
1789 				BSTP_UNLOCK(bs);
1790 				mtx_unlock(&bstp_list_mtx);
1791 				return;
1792 			}
1793 		}
1794 		BSTP_UNLOCK(bs);
1795 	}
1796 	mtx_unlock(&bstp_list_mtx);
1797 }
1798 
1799 static void
1800 bstp_ifupdstatus(struct bstp_state *bs, struct bstp_port *bp)
1801 {
1802 	struct ifnet *ifp = bp->bp_ifp;
1803 	struct ifmediareq ifmr;
1804 	int error = 0;
1805 
1806 	BSTP_LOCK_ASSERT(bs);
1807 
1808 	bzero((char *)&ifmr, sizeof(ifmr));
1809 	error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);
1810 
1811 	if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1812 		if (ifmr.ifm_status & IFM_ACTIVE) {
1813 			/* A full-duplex link is assumed to be point to point */
1814 			if (bp->bp_flags & BSTP_PORT_AUTOPTP) {
1815 				bp->bp_ptp_link =
1816 				    ifmr.ifm_active & IFM_FDX ? 1 : 0;
1817 			}
1818 
1819 			/* Calc the cost if the link was down previously */
1820 			if (bp->bp_flags & BSTP_PORT_PNDCOST) {
1821 				bp->bp_path_cost = bstp_calc_path_cost(bp);
1822 				bp->bp_flags &= ~BSTP_PORT_PNDCOST;
1823 			}
1824 
1825 			if (bp->bp_role == BSTP_ROLE_DISABLED)
1826 				bstp_enable_port(bs, bp);
1827 		} else {
1828 			if (bp->bp_role != BSTP_ROLE_DISABLED) {
1829 				bstp_disable_port(bs, bp);
1830 				if ((bp->bp_flags & BSTP_PORT_ADMEDGE) &&
1831 				    bp->bp_protover == BSTP_PROTO_RSTP)
1832 					bp->bp_operedge = 1;
1833 			}
1834 		}
1835 		return;
1836 	}
1837 
1838 	if (bp->bp_infois != BSTP_INFO_DISABLED)
1839 		bstp_disable_port(bs, bp);
1840 }
1841 
1842 static void
1843 bstp_enable_port(struct bstp_state *bs, struct bstp_port *bp)
1844 {
1845 	bp->bp_infois = BSTP_INFO_AGED;
1846 	bstp_assign_roles(bs);
1847 }
1848 
1849 static void
1850 bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
1851 {
1852 	bp->bp_infois = BSTP_INFO_DISABLED;
1853 	bstp_assign_roles(bs);
1854 }
1855 
1856 static void
1857 bstp_tick(void *arg)
1858 {
1859 	struct bstp_state *bs = arg;
1860 	struct bstp_port *bp;
1861 
1862 	BSTP_LOCK_ASSERT(bs);
1863 
1864 	if (bs->bs_running == 0)
1865 		return;
1866 
1867 	/* slow timer to catch missed link events */
1868 	if (bstp_timer_expired(&bs->bs_link_timer)) {
1869 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1870 			bstp_ifupdstatus(bs, bp);
1871 		bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
1872 	}
1873 
1874 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1875 		/* no events need to happen for these */
1876 		bstp_timer_expired(&bp->bp_tc_timer);
1877 		bstp_timer_expired(&bp->bp_recent_root_timer);
1878 		bstp_timer_expired(&bp->bp_forward_delay_timer);
1879 		bstp_timer_expired(&bp->bp_recent_backup_timer);
1880 
1881 		if (bstp_timer_expired(&bp->bp_hello_timer))
1882 			bstp_hello_timer_expiry(bs, bp);
1883 
1884 		if (bstp_timer_expired(&bp->bp_message_age_timer))
1885 			bstp_message_age_expiry(bs, bp);
1886 
1887 		if (bstp_timer_expired(&bp->bp_migrate_delay_timer))
1888 			bstp_migrate_delay_expiry(bs, bp);
1889 
1890 		if (bstp_timer_expired(&bp->bp_edge_delay_timer))
1891 			bstp_edge_delay_expiry(bs, bp);
1892 
1893 		/* update the various state machines for the port */
1894 		bstp_update_state(bs, bp);
1895 
1896 		if (bp->bp_txcount > 0)
1897 			bp->bp_txcount--;
1898 	}
1899 
1900 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
1901 }
1902 
1903 static void
1904 bstp_timer_start(struct bstp_timer *t, uint16_t v)
1905 {
1906 	t->value = v;
1907 	t->active = 1;
1908 	t->latched = 0;
1909 }
1910 
1911 static void
1912 bstp_timer_stop(struct bstp_timer *t)
1913 {
1914 	t->value = 0;
1915 	t->active = 0;
1916 	t->latched = 0;
1917 }
1918 
1919 static void
1920 bstp_timer_latch(struct bstp_timer *t)
1921 {
1922 	t->latched = 1;
1923 	t->active = 1;
1924 }
1925 
1926 static int
1927 bstp_timer_expired(struct bstp_timer *t)
1928 {
1929 	if (t->active == 0 || t->latched)
1930 		return (0);
1931 	t->value -= BSTP_TICK_VAL;
1932 	if (t->value <= 0) {
1933 		bstp_timer_stop(t);
1934 		return (1);
1935 	}
1936 	return (0);
1937 }
1938 
1939 static void
1940 bstp_hello_timer_expiry(struct bstp_state *bs, struct bstp_port *bp)
1941 {
1942 	if ((bp->bp_flags & BSTP_PORT_NEWINFO) ||
1943 	    bp->bp_role == BSTP_ROLE_DESIGNATED ||
1944 	    (bp->bp_role == BSTP_ROLE_ROOT &&
1945 	     bp->bp_tc_timer.active == 1)) {
1946 		bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
1947 		bp->bp_flags |= BSTP_PORT_NEWINFO;
1948 		bstp_transmit(bs, bp);
1949 	}
1950 }
1951 
1952 static void
1953 bstp_message_age_expiry(struct bstp_state *bs, struct bstp_port *bp)
1954 {
1955 	if (bp->bp_infois == BSTP_INFO_RECEIVED) {
1956 		bp->bp_infois = BSTP_INFO_AGED;
1957 		bstp_assign_roles(bs);
1958 		DPRINTF("aged info on %s\n", bp->bp_ifp->if_xname);
1959 	}
1960 }
1961 
1962 static void
1963 bstp_migrate_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1964 {
1965 	bp->bp_flags |= BSTP_PORT_CANMIGRATE;
1966 }
1967 
1968 static void
1969 bstp_edge_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1970 {
1971 	if ((bp->bp_flags & BSTP_PORT_AUTOEDGE) &&
1972 	    bp->bp_protover == BSTP_PROTO_RSTP && bp->bp_proposing &&
1973 	    bp->bp_role == BSTP_ROLE_DESIGNATED) {
1974 		bp->bp_operedge = 1;
1975 		DPRINTF("%s -> edge port\n", bp->bp_ifp->if_xname);
1976 	}
1977 }
1978 
1979 static int
1980 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
1981 {
1982 	int i, d;
1983 
1984 	for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
1985 		d = ((int)a[i]) - ((int)b[i]);
1986 	}
1987 
1988 	return (d);
1989 }
1990 
1991 /*
1992  * compare the bridge address component of the bridgeid
1993  */
1994 static int
1995 bstp_same_bridgeid(uint64_t id1, uint64_t id2)
1996 {
1997 	u_char addr1[ETHER_ADDR_LEN];
1998 	u_char addr2[ETHER_ADDR_LEN];
1999 
2000 	PV2ADDR(id1, addr1);
2001 	PV2ADDR(id2, addr2);
2002 
2003 	if (bstp_addr_cmp(addr1, addr2) == 0)
2004 		return (1);
2005 
2006 	return (0);
2007 }
2008 
2009 void
2010 bstp_reinit(struct bstp_state *bs)
2011 {
2012 	INIT_VNET_NET(curvnet);
2013 	struct bstp_port *bp;
2014 	struct ifnet *ifp, *mif;
2015 	u_char *e_addr;
2016 	static const u_char llzero[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */
2017 
2018 	BSTP_LOCK_ASSERT(bs);
2019 
2020 	mif = NULL;
2021 	/*
2022 	 * Search through the Ethernet adapters and find the one with the
2023 	 * lowest value. The adapter which we take the MAC address from does
2024 	 * not need to be part of the bridge, it just needs to be a unique
2025 	 * value.
2026 	 */
2027 	IFNET_RLOCK();
2028 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2029 		if (ifp->if_type != IFT_ETHER)
2030 			continue;
2031 
2032 		if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
2033 			continue;
2034 
2035 		if (mif == NULL) {
2036 			mif = ifp;
2037 			continue;
2038 		}
2039 		if (bstp_addr_cmp(IF_LLADDR(ifp), IF_LLADDR(mif)) < 0) {
2040 			mif = ifp;
2041 			continue;
2042 		}
2043 	}
2044 	IFNET_RUNLOCK();
2045 
2046 	if (LIST_EMPTY(&bs->bs_bplist) || mif == NULL) {
2047 		/* Set the bridge and root id (lower bits) to zero */
2048 		bs->bs_bridge_pv.pv_dbridge_id =
2049 		    ((uint64_t)bs->bs_bridge_priority) << 48;
2050 		bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2051 		bs->bs_root_pv = bs->bs_bridge_pv;
2052 		/* Disable any remaining ports, they will have no MAC address */
2053 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2054 			bp->bp_infois = BSTP_INFO_DISABLED;
2055 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2056 		}
2057 		callout_stop(&bs->bs_bstpcallout);
2058 		return;
2059 	}
2060 
2061 	e_addr = IF_LLADDR(mif);
2062 	bs->bs_bridge_pv.pv_dbridge_id =
2063 	    (((uint64_t)bs->bs_bridge_priority) << 48) |
2064 	    (((uint64_t)e_addr[0]) << 40) |
2065 	    (((uint64_t)e_addr[1]) << 32) |
2066 	    (((uint64_t)e_addr[2]) << 24) |
2067 	    (((uint64_t)e_addr[3]) << 16) |
2068 	    (((uint64_t)e_addr[4]) << 8) |
2069 	    (((uint64_t)e_addr[5]));
2070 
2071 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2072 	bs->bs_bridge_pv.pv_cost = 0;
2073 	bs->bs_bridge_pv.pv_dport_id = 0;
2074 	bs->bs_bridge_pv.pv_port_id = 0;
2075 
2076 	if (bs->bs_running && callout_pending(&bs->bs_bstpcallout) == 0)
2077 		callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2078 
2079 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2080 		bp->bp_port_id = (bp->bp_priority << 8) |
2081 		    (bp->bp_ifp->if_index  & 0xfff);
2082 		bstp_ifupdstatus(bs, bp);
2083 	}
2084 
2085 	bstp_assign_roles(bs);
2086 	bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
2087 }
2088 
2089 static int
2090 bstp_modevent(module_t mod, int type, void *data)
2091 {
2092 	switch (type) {
2093 	case MOD_LOAD:
2094 		mtx_init(&bstp_list_mtx, "bridgestp list", NULL, MTX_DEF);
2095 		LIST_INIT(&bstp_list);
2096 		bstp_linkstate_p = bstp_linkstate;
2097 		break;
2098 	case MOD_UNLOAD:
2099 		bstp_linkstate_p = NULL;
2100 		mtx_destroy(&bstp_list_mtx);
2101 		break;
2102 	default:
2103 		return (EOPNOTSUPP);
2104 	}
2105 	return (0);
2106 }
2107 
2108 static moduledata_t bstp_mod = {
2109 	"bridgestp",
2110 	bstp_modevent,
2111 	0
2112 };
2113 
2114 DECLARE_MODULE(bridgestp, bstp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2115 MODULE_VERSION(bridgestp, 1);
2116 
2117 void
2118 bstp_attach(struct bstp_state *bs, struct bstp_cb_ops *cb)
2119 {
2120 	BSTP_LOCK_INIT(bs);
2121 	callout_init_mtx(&bs->bs_bstpcallout, &bs->bs_mtx, 0);
2122 	LIST_INIT(&bs->bs_bplist);
2123 
2124 	bs->bs_bridge_max_age = BSTP_DEFAULT_MAX_AGE;
2125 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
2126 	bs->bs_bridge_fdelay = BSTP_DEFAULT_FORWARD_DELAY;
2127 	bs->bs_bridge_priority = BSTP_DEFAULT_BRIDGE_PRIORITY;
2128 	bs->bs_hold_time = BSTP_DEFAULT_HOLD_TIME;
2129 	bs->bs_migration_delay = BSTP_DEFAULT_MIGRATE_DELAY;
2130 	bs->bs_txholdcount = BSTP_DEFAULT_HOLD_COUNT;
2131 	bs->bs_protover = BSTP_PROTO_RSTP;
2132 	bs->bs_state_cb = cb->bcb_state;
2133 	bs->bs_rtage_cb = cb->bcb_rtage;
2134 
2135 	getmicrotime(&bs->bs_last_tc_time);
2136 
2137 	mtx_lock(&bstp_list_mtx);
2138 	LIST_INSERT_HEAD(&bstp_list, bs, bs_list);
2139 	mtx_unlock(&bstp_list_mtx);
2140 }
2141 
2142 void
2143 bstp_detach(struct bstp_state *bs)
2144 {
2145 	KASSERT(LIST_EMPTY(&bs->bs_bplist), ("bstp still active"));
2146 
2147 	mtx_lock(&bstp_list_mtx);
2148 	LIST_REMOVE(bs, bs_list);
2149 	mtx_unlock(&bstp_list_mtx);
2150 	callout_drain(&bs->bs_bstpcallout);
2151 	BSTP_LOCK_DESTROY(bs);
2152 }
2153 
2154 void
2155 bstp_init(struct bstp_state *bs)
2156 {
2157 	BSTP_LOCK(bs);
2158 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2159 	bs->bs_running = 1;
2160 	bstp_reinit(bs);
2161 	BSTP_UNLOCK(bs);
2162 }
2163 
2164 void
2165 bstp_stop(struct bstp_state *bs)
2166 {
2167 	struct bstp_port *bp;
2168 
2169 	BSTP_LOCK(bs);
2170 
2171 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
2172 		bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2173 
2174 	bs->bs_running = 0;
2175 	callout_stop(&bs->bs_bstpcallout);
2176 	BSTP_UNLOCK(bs);
2177 }
2178 
2179 int
2180 bstp_create(struct bstp_state *bs, struct bstp_port *bp, struct ifnet *ifp)
2181 {
2182 	bzero(bp, sizeof(struct bstp_port));
2183 
2184 	BSTP_LOCK(bs);
2185 	bp->bp_ifp = ifp;
2186 	bp->bp_bs = bs;
2187 	bp->bp_priority = BSTP_DEFAULT_PORT_PRIORITY;
2188 	TASK_INIT(&bp->bp_statetask, 0, bstp_notify_state, bp);
2189 	TASK_INIT(&bp->bp_rtagetask, 0, bstp_notify_rtage, bp);
2190 
2191 	/* Init state */
2192 	bp->bp_infois = BSTP_INFO_DISABLED;
2193 	bp->bp_flags = BSTP_PORT_AUTOEDGE|BSTP_PORT_AUTOPTP;
2194 	bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2195 	bstp_set_port_proto(bp, bs->bs_protover);
2196 	bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2197 	bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
2198 	bp->bp_path_cost = bstp_calc_path_cost(bp);
2199 	BSTP_UNLOCK(bs);
2200 	return (0);
2201 }
2202 
2203 int
2204 bstp_enable(struct bstp_port *bp)
2205 {
2206 	struct bstp_state *bs = bp->bp_bs;
2207 	struct ifnet *ifp = bp->bp_ifp;
2208 
2209 	KASSERT(bp->bp_active == 0, ("already a bstp member"));
2210 
2211 	switch (ifp->if_type) {
2212 		case IFT_ETHER:	/* These can do spanning tree. */
2213 			break;
2214 		default:
2215 			/* Nothing else can. */
2216 			return (EINVAL);
2217 	}
2218 
2219 	BSTP_LOCK(bs);
2220 	LIST_INSERT_HEAD(&bs->bs_bplist, bp, bp_next);
2221 	bp->bp_active = 1;
2222 	bp->bp_flags |= BSTP_PORT_NEWINFO;
2223 	bstp_reinit(bs);
2224 	bstp_update_roles(bs, bp);
2225 	BSTP_UNLOCK(bs);
2226 	return (0);
2227 }
2228 
2229 void
2230 bstp_disable(struct bstp_port *bp)
2231 {
2232 	struct bstp_state *bs = bp->bp_bs;
2233 
2234 	KASSERT(bp->bp_active == 1, ("not a bstp member"));
2235 
2236 	BSTP_LOCK(bs);
2237 	bstp_disable_port(bs, bp);
2238 	LIST_REMOVE(bp, bp_next);
2239 	bp->bp_active = 0;
2240 	bstp_reinit(bs);
2241 	BSTP_UNLOCK(bs);
2242 }
2243 
2244 /*
2245  * The bstp_port structure is about to be freed by the parent bridge.
2246  */
2247 void
2248 bstp_destroy(struct bstp_port *bp)
2249 {
2250 	KASSERT(bp->bp_active == 0, ("port is still attached"));
2251 	taskqueue_drain(taskqueue_swi, &bp->bp_statetask);
2252 	taskqueue_drain(taskqueue_swi, &bp->bp_rtagetask);
2253 }
2254