xref: /freebsd/sys/net/bridgestp.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 /*	$NetBSD: bridgestp.c,v 1.5 2003/11/28 08:56:48 keihan Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
5  *
6  * Copyright (c) 2000 Jason L. Wright (jason@thought.net)
7  * Copyright (c) 2006 Andrew Thompson (thompsa@FreeBSD.org)
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
23  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
28  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  *
31  * OpenBSD: bridgestp.c,v 1.5 2001/03/22 03:48:29 jason Exp
32  */
33 
34 /*
35  * Implementation of the spanning tree protocol as defined in
36  * ISO/IEC 802.1D-2004, June 9, 2004.
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
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/malloc.h>
49 #include <sys/callout.h>
50 #include <sys/module.h>
51 #include <sys/proc.h>
52 #include <sys/lock.h>
53 #include <sys/mutex.h>
54 #include <sys/taskqueue.h>
55 
56 #include <net/if.h>
57 #include <net/if_var.h>
58 #include <net/if_dl.h>
59 #include <net/if_types.h>
60 #include <net/if_llc.h>
61 #include <net/if_media.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...)	(void)0
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(void *, int);
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_dectest(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 	m = m_gethdr(M_NOWAIT, 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 	m = m_gethdr(M_NOWAIT, 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 void
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;
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 }
529 
530 static void
531 bstp_received_stp(struct bstp_state *bs, struct bstp_port *bp,
532     struct mbuf **mp, struct bstp_tbpdu *tpdu)
533 {
534 	struct bstp_cbpdu cpdu;
535 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
536 	struct bstp_tcn_unit tu;
537 
538 	switch (tpdu->tbu_bpdutype) {
539 	case BSTP_MSGTYPE_TCN:
540 		tu.tu_message_type = tpdu->tbu_bpdutype;
541 		bstp_received_tcn(bs, bp, &tu);
542 		break;
543 	case BSTP_MSGTYPE_CFG:
544 		if ((*mp)->m_len < BSTP_BPDU_STP_LEN &&
545 		    (*mp = m_pullup(*mp, BSTP_BPDU_STP_LEN)) == NULL)
546 			return;
547 		memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_STP_LEN);
548 
549 		bstp_decode_bpdu(bp, &cpdu, cu);
550 		bstp_received_bpdu(bs, bp, cu);
551 		break;
552 	}
553 }
554 
555 static void
556 bstp_received_rstp(struct bstp_state *bs, struct bstp_port *bp,
557     struct mbuf **mp, struct bstp_tbpdu *tpdu)
558 {
559 	struct bstp_cbpdu cpdu;
560 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
561 
562 	if (tpdu->tbu_bpdutype != BSTP_MSGTYPE_RSTP)
563 		return;
564 
565 	if ((*mp)->m_len < BSTP_BPDU_RSTP_LEN &&
566 	    (*mp = m_pullup(*mp, BSTP_BPDU_RSTP_LEN)) == NULL)
567 		return;
568 	memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_RSTP_LEN);
569 
570 	bstp_decode_bpdu(bp, &cpdu, cu);
571 	bstp_received_bpdu(bs, bp, cu);
572 }
573 
574 static void
575 bstp_received_tcn(struct bstp_state *bs, struct bstp_port *bp,
576     struct bstp_tcn_unit *tcn)
577 {
578 	bp->bp_rcvdtcn = 1;
579 	bstp_update_tc(bp);
580 }
581 
582 static void
583 bstp_received_bpdu(struct bstp_state *bs, struct bstp_port *bp,
584     struct bstp_config_unit *cu)
585 {
586 	int type;
587 
588 	BSTP_LOCK_ASSERT(bs);
589 
590 	/* We need to have transitioned to INFO_MINE before proceeding */
591 	switch (bp->bp_infois) {
592 		case BSTP_INFO_DISABLED:
593 		case BSTP_INFO_AGED:
594 			return;
595 	}
596 
597 	type = bstp_pdu_rcvtype(bp, cu);
598 
599 	switch (type) {
600 		case BSTP_PDU_SUPERIOR:
601 			bs->bs_allsynced = 0;
602 			bp->bp_agreed = 0;
603 			bp->bp_proposing = 0;
604 
605 			if (cu->cu_proposal && cu->cu_forwarding == 0)
606 				bp->bp_proposed = 1;
607 			if (cu->cu_topology_change)
608 				bp->bp_rcvdtc = 1;
609 			if (cu->cu_topology_change_ack)
610 				bp->bp_rcvdtca = 1;
611 
612 			if (bp->bp_agree &&
613 			    !bstp_pdu_bettersame(bp, BSTP_INFO_RECEIVED))
614 				bp->bp_agree = 0;
615 
616 			/* copy the received priority and timers to the port */
617 			bp->bp_port_pv = cu->cu_pv;
618 			bp->bp_port_msg_age = cu->cu_message_age;
619 			bp->bp_port_max_age = cu->cu_max_age;
620 			bp->bp_port_fdelay = cu->cu_forward_delay;
621 			bp->bp_port_htime =
622 				(cu->cu_hello_time > BSTP_MIN_HELLO_TIME ?
623 				 cu->cu_hello_time : BSTP_MIN_HELLO_TIME);
624 
625 			/* set expiry for the new info */
626 			bstp_set_timer_msgage(bp);
627 
628 			bp->bp_infois = BSTP_INFO_RECEIVED;
629 			bstp_assign_roles(bs);
630 			break;
631 
632 		case BSTP_PDU_REPEATED:
633 			if (cu->cu_proposal && cu->cu_forwarding == 0)
634 				bp->bp_proposed = 1;
635 			if (cu->cu_topology_change)
636 				bp->bp_rcvdtc = 1;
637 			if (cu->cu_topology_change_ack)
638 				bp->bp_rcvdtca = 1;
639 
640 			/* rearm the age timer */
641 			bstp_set_timer_msgage(bp);
642 			break;
643 
644 		case BSTP_PDU_INFERIOR:
645 			if (cu->cu_learning) {
646 				bp->bp_agreed = 1;
647 				bp->bp_proposing = 0;
648 			}
649 			break;
650 
651 		case BSTP_PDU_INFERIORALT:
652 			/*
653 			 * only point to point links are allowed fast
654 			 * transitions to forwarding.
655 			 */
656 			if (cu->cu_agree && bp->bp_ptp_link) {
657 				bp->bp_agreed = 1;
658 				bp->bp_proposing = 0;
659 			} else
660 				bp->bp_agreed = 0;
661 
662 			if (cu->cu_topology_change)
663 				bp->bp_rcvdtc = 1;
664 			if (cu->cu_topology_change_ack)
665 				bp->bp_rcvdtca = 1;
666 			break;
667 
668 		case BSTP_PDU_OTHER:
669 			return;	/* do nothing */
670 	}
671 	/* update the state machines with the new data */
672 	bstp_update_state(bs, bp);
673 }
674 
675 static int
676 bstp_pdu_rcvtype(struct bstp_port *bp, struct bstp_config_unit *cu)
677 {
678 	int type;
679 
680 	/* default return type */
681 	type = BSTP_PDU_OTHER;
682 
683 	switch (cu->cu_role) {
684 	case BSTP_ROLE_DESIGNATED:
685 		if (bstp_info_superior(&bp->bp_port_pv, &cu->cu_pv))
686 			/* bpdu priority is superior */
687 			type = BSTP_PDU_SUPERIOR;
688 		else if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) ==
689 		    INFO_SAME) {
690 			if (bp->bp_port_msg_age != cu->cu_message_age ||
691 			    bp->bp_port_max_age != cu->cu_max_age ||
692 			    bp->bp_port_fdelay != cu->cu_forward_delay ||
693 			    bp->bp_port_htime != cu->cu_hello_time)
694 				/* bpdu priority is equal and timers differ */
695 				type = BSTP_PDU_SUPERIOR;
696 			else
697 				/* bpdu is equal */
698 				type = BSTP_PDU_REPEATED;
699 		} else
700 			/* bpdu priority is worse */
701 			type = BSTP_PDU_INFERIOR;
702 
703 		break;
704 
705 	case BSTP_ROLE_ROOT:
706 	case BSTP_ROLE_ALTERNATE:
707 	case BSTP_ROLE_BACKUP:
708 		if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) <= INFO_SAME)
709 			/*
710 			 * not a designated port and priority is the same or
711 			 * worse
712 			 */
713 			type = BSTP_PDU_INFERIORALT;
714 		break;
715 	}
716 
717 	return (type);
718 }
719 
720 static int
721 bstp_pdu_bettersame(struct bstp_port *bp, int newinfo)
722 {
723 	if (newinfo == BSTP_INFO_RECEIVED &&
724 	    bp->bp_infois == BSTP_INFO_RECEIVED &&
725 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_msg_cu.cu_pv) >= INFO_SAME)
726 		return (1);
727 
728 	if (newinfo == BSTP_INFO_MINE &&
729 	    bp->bp_infois == BSTP_INFO_MINE &&
730 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_desg_pv) >= INFO_SAME)
731 		return (1);
732 
733 	return (0);
734 }
735 
736 static int
737 bstp_info_cmp(struct bstp_pri_vector *pv,
738     struct bstp_pri_vector *cpv)
739 {
740 	if (cpv->pv_root_id < pv->pv_root_id)
741 		return (INFO_BETTER);
742 	if (cpv->pv_root_id > pv->pv_root_id)
743 		return (INFO_WORSE);
744 
745 	if (cpv->pv_cost < pv->pv_cost)
746 		return (INFO_BETTER);
747 	if (cpv->pv_cost > pv->pv_cost)
748 		return (INFO_WORSE);
749 
750 	if (cpv->pv_dbridge_id < pv->pv_dbridge_id)
751 		return (INFO_BETTER);
752 	if (cpv->pv_dbridge_id > pv->pv_dbridge_id)
753 		return (INFO_WORSE);
754 
755 	if (cpv->pv_dport_id < pv->pv_dport_id)
756 		return (INFO_BETTER);
757 	if (cpv->pv_dport_id > pv->pv_dport_id)
758 		return (INFO_WORSE);
759 
760 	return (INFO_SAME);
761 }
762 
763 /*
764  * This message priority vector is superior to the port priority vector and
765  * will replace it if, and only if, the message priority vector is better than
766  * the port priority vector, or the message has been transmitted from the same
767  * designated bridge and designated port as the port priority vector.
768  */
769 static int
770 bstp_info_superior(struct bstp_pri_vector *pv,
771     struct bstp_pri_vector *cpv)
772 {
773 	if (bstp_info_cmp(pv, cpv) == INFO_BETTER ||
774 	    (bstp_same_bridgeid(pv->pv_dbridge_id, cpv->pv_dbridge_id) &&
775 	    (cpv->pv_dport_id & 0xfff) == (pv->pv_dport_id & 0xfff)))
776 		return (1);
777 	return (0);
778 }
779 
780 static void
781 bstp_assign_roles(struct bstp_state *bs)
782 {
783 	struct bstp_port *bp, *rbp = NULL;
784 	struct bstp_pri_vector pv;
785 
786 	/* default to our priority vector */
787 	bs->bs_root_pv = bs->bs_bridge_pv;
788 	bs->bs_root_msg_age = 0;
789 	bs->bs_root_max_age = bs->bs_bridge_max_age;
790 	bs->bs_root_fdelay = bs->bs_bridge_fdelay;
791 	bs->bs_root_htime = bs->bs_bridge_htime;
792 	bs->bs_root_port = NULL;
793 
794 	/* check if any received info supersedes us */
795 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
796 		if (bp->bp_infois != BSTP_INFO_RECEIVED)
797 			continue;
798 
799 		pv = bp->bp_port_pv;
800 		pv.pv_cost += bp->bp_path_cost;
801 
802 		/*
803 		 * The root priority vector is the best of the set comprising
804 		 * the bridge priority vector plus all root path priority
805 		 * vectors whose bridge address is not equal to us.
806 		 */
807 		if (bstp_same_bridgeid(pv.pv_dbridge_id,
808 		    bs->bs_bridge_pv.pv_dbridge_id) == 0 &&
809 		    bstp_info_cmp(&bs->bs_root_pv, &pv) == INFO_BETTER) {
810 			/* the port vector replaces the root */
811 			bs->bs_root_pv = pv;
812 			bs->bs_root_msg_age = bp->bp_port_msg_age +
813 			    BSTP_MESSAGE_AGE_INCR;
814 			bs->bs_root_max_age = bp->bp_port_max_age;
815 			bs->bs_root_fdelay = bp->bp_port_fdelay;
816 			bs->bs_root_htime = bp->bp_port_htime;
817 			rbp = bp;
818 		}
819 	}
820 
821 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
822 		/* calculate the port designated vector */
823 		bp->bp_desg_pv.pv_root_id = bs->bs_root_pv.pv_root_id;
824 		bp->bp_desg_pv.pv_cost = bs->bs_root_pv.pv_cost;
825 		bp->bp_desg_pv.pv_dbridge_id = bs->bs_bridge_pv.pv_dbridge_id;
826 		bp->bp_desg_pv.pv_dport_id = bp->bp_port_id;
827 		bp->bp_desg_pv.pv_port_id = bp->bp_port_id;
828 
829 		/* calculate designated times */
830 		bp->bp_desg_msg_age = bs->bs_root_msg_age;
831 		bp->bp_desg_max_age = bs->bs_root_max_age;
832 		bp->bp_desg_fdelay = bs->bs_root_fdelay;
833 		bp->bp_desg_htime = bs->bs_bridge_htime;
834 
835 		switch (bp->bp_infois) {
836 		case BSTP_INFO_DISABLED:
837 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
838 			break;
839 
840 		case BSTP_INFO_AGED:
841 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
842 			bstp_update_info(bp);
843 			break;
844 
845 		case BSTP_INFO_MINE:
846 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
847 			/* update the port info if stale */
848 			if (bstp_info_cmp(&bp->bp_port_pv,
849 			    &bp->bp_desg_pv) != INFO_SAME ||
850 			    (rbp != NULL &&
851 			    (bp->bp_port_msg_age != rbp->bp_port_msg_age ||
852 			    bp->bp_port_max_age != rbp->bp_port_max_age ||
853 			    bp->bp_port_fdelay != rbp->bp_port_fdelay ||
854 			    bp->bp_port_htime != rbp->bp_port_htime)))
855 				bstp_update_info(bp);
856 			break;
857 
858 		case BSTP_INFO_RECEIVED:
859 			if (bp == rbp) {
860 				/*
861 				 * root priority is derived from this
862 				 * port, make it the root port.
863 				 */
864 				bstp_set_port_role(bp, BSTP_ROLE_ROOT);
865 				bs->bs_root_port = bp;
866 			} else if (bstp_info_cmp(&bp->bp_port_pv,
867 				    &bp->bp_desg_pv) == INFO_BETTER) {
868 				/*
869 				 * the port priority is lower than the root
870 				 * port.
871 				 */
872 				bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
873 				bstp_update_info(bp);
874 			} else {
875 				if (bstp_same_bridgeid(
876 				    bp->bp_port_pv.pv_dbridge_id,
877 				    bs->bs_bridge_pv.pv_dbridge_id)) {
878 					/*
879 					 * the designated bridge refers to
880 					 * another port on this bridge.
881 					 */
882 					bstp_set_port_role(bp,
883 					    BSTP_ROLE_BACKUP);
884 				} else {
885 					/*
886 					 * the port is an inferior path to the
887 					 * root bridge.
888 					 */
889 					bstp_set_port_role(bp,
890 					    BSTP_ROLE_ALTERNATE);
891 				}
892 			}
893 			break;
894 		}
895 	}
896 }
897 
898 static void
899 bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
900 {
901 	struct bstp_port *bp2;
902 	int synced;
903 
904 	BSTP_LOCK_ASSERT(bs);
905 
906 	/* check if all the ports have syncronised again */
907 	if (!bs->bs_allsynced) {
908 		synced = 1;
909 		LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
910 			if (!(bp2->bp_synced ||
911 			     bp2->bp_role == BSTP_ROLE_ROOT)) {
912 				synced = 0;
913 				break;
914 			}
915 		}
916 		bs->bs_allsynced = synced;
917 	}
918 
919 	bstp_update_roles(bs, bp);
920 	bstp_update_tc(bp);
921 }
922 
923 static void
924 bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
925 {
926 	switch (bp->bp_role) {
927 	case BSTP_ROLE_DISABLED:
928 		/* Clear any flags if set */
929 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
930 			bp->bp_sync = 0;
931 			bp->bp_synced = 1;
932 			bp->bp_reroot = 0;
933 		}
934 		break;
935 
936 	case BSTP_ROLE_ALTERNATE:
937 	case BSTP_ROLE_BACKUP:
938 		if ((bs->bs_allsynced && !bp->bp_agree) ||
939 		    (bp->bp_proposed && bp->bp_agree)) {
940 			bp->bp_proposed = 0;
941 			bp->bp_agree = 1;
942 			bp->bp_flags |= BSTP_PORT_NEWINFO;
943 			DPRINTF("%s -> ALTERNATE_AGREED\n",
944 			    bp->bp_ifp->if_xname);
945 		}
946 
947 		if (bp->bp_proposed && !bp->bp_agree) {
948 			bstp_set_all_sync(bs);
949 			bp->bp_proposed = 0;
950 			DPRINTF("%s -> ALTERNATE_PROPOSED\n",
951 			    bp->bp_ifp->if_xname);
952 		}
953 
954 		/* Clear any flags if set */
955 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
956 			bp->bp_sync = 0;
957 			bp->bp_synced = 1;
958 			bp->bp_reroot = 0;
959 			DPRINTF("%s -> ALTERNATE_PORT\n", bp->bp_ifp->if_xname);
960 		}
961 		break;
962 
963 	case BSTP_ROLE_ROOT:
964 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING && !bp->bp_reroot) {
965 			bstp_set_all_reroot(bs);
966 			DPRINTF("%s -> ROOT_REROOT\n", bp->bp_ifp->if_xname);
967 		}
968 
969 		if ((bs->bs_allsynced && !bp->bp_agree) ||
970 		    (bp->bp_proposed && bp->bp_agree)) {
971 			bp->bp_proposed = 0;
972 			bp->bp_sync = 0;
973 			bp->bp_agree = 1;
974 			bp->bp_flags |= BSTP_PORT_NEWINFO;
975 			DPRINTF("%s -> ROOT_AGREED\n", bp->bp_ifp->if_xname);
976 		}
977 
978 		if (bp->bp_proposed && !bp->bp_agree) {
979 			bstp_set_all_sync(bs);
980 			bp->bp_proposed = 0;
981 			DPRINTF("%s -> ROOT_PROPOSED\n", bp->bp_ifp->if_xname);
982 		}
983 
984 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
985 		    (bp->bp_forward_delay_timer.active == 0 ||
986 		    (bstp_rerooted(bs, bp) &&
987 		    bp->bp_recent_backup_timer.active == 0 &&
988 		    bp->bp_protover == BSTP_PROTO_RSTP))) {
989 			switch (bp->bp_state) {
990 			case BSTP_IFSTATE_DISCARDING:
991 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
992 				break;
993 			case BSTP_IFSTATE_LEARNING:
994 				bstp_set_port_state(bp,
995 				    BSTP_IFSTATE_FORWARDING);
996 				break;
997 			}
998 		}
999 
1000 		if (bp->bp_state == BSTP_IFSTATE_FORWARDING && bp->bp_reroot) {
1001 			bp->bp_reroot = 0;
1002 			DPRINTF("%s -> ROOT_REROOTED\n", bp->bp_ifp->if_xname);
1003 		}
1004 		break;
1005 
1006 	case BSTP_ROLE_DESIGNATED:
1007 		if (bp->bp_recent_root_timer.active == 0 && bp->bp_reroot) {
1008 			bp->bp_reroot = 0;
1009 			DPRINTF("%s -> DESIGNATED_RETIRED\n",
1010 			    bp->bp_ifp->if_xname);
1011 		}
1012 
1013 		if ((bp->bp_state == BSTP_IFSTATE_DISCARDING &&
1014 		    !bp->bp_synced) || (bp->bp_agreed && !bp->bp_synced) ||
1015 		    (bp->bp_operedge && !bp->bp_synced) ||
1016 		    (bp->bp_sync && bp->bp_synced)) {
1017 			bstp_timer_stop(&bp->bp_recent_root_timer);
1018 			bp->bp_synced = 1;
1019 			bp->bp_sync = 0;
1020 			DPRINTF("%s -> DESIGNATED_SYNCED\n",
1021 			    bp->bp_ifp->if_xname);
1022 		}
1023 
1024 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1025 		    !bp->bp_agreed && !bp->bp_proposing &&
1026 		    !bp->bp_operedge) {
1027 			bp->bp_proposing = 1;
1028 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1029 			bstp_timer_start(&bp->bp_edge_delay_timer,
1030 			    (bp->bp_ptp_link ? BSTP_DEFAULT_MIGRATE_DELAY :
1031 			     bp->bp_desg_max_age));
1032 			DPRINTF("%s -> DESIGNATED_PROPOSE\n",
1033 			    bp->bp_ifp->if_xname);
1034 		}
1035 
1036 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1037 		    (bp->bp_forward_delay_timer.active == 0 || bp->bp_agreed ||
1038 		    bp->bp_operedge) &&
1039 		    (bp->bp_recent_root_timer.active == 0 || !bp->bp_reroot) &&
1040 		    !bp->bp_sync) {
1041 			if (bp->bp_agreed)
1042 				DPRINTF("%s -> AGREED\n", bp->bp_ifp->if_xname);
1043 			/*
1044 			 * If agreed|operedge then go straight to forwarding,
1045 			 * otherwise follow discard -> learn -> forward.
1046 			 */
1047 			if (bp->bp_agreed || bp->bp_operedge ||
1048 			    bp->bp_state == BSTP_IFSTATE_LEARNING) {
1049 				bstp_set_port_state(bp,
1050 				    BSTP_IFSTATE_FORWARDING);
1051 				bp->bp_agreed = bp->bp_protover;
1052 			} else if (bp->bp_state == BSTP_IFSTATE_DISCARDING)
1053 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
1054 		}
1055 
1056 		if (((bp->bp_sync && !bp->bp_synced) ||
1057 		    (bp->bp_reroot && bp->bp_recent_root_timer.active) ||
1058 		    (bp->bp_flags & BSTP_PORT_DISPUTED)) && !bp->bp_operedge &&
1059 		    bp->bp_state != BSTP_IFSTATE_DISCARDING) {
1060 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1061 			bp->bp_flags &= ~BSTP_PORT_DISPUTED;
1062 			bstp_timer_start(&bp->bp_forward_delay_timer,
1063 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1064 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1065 			DPRINTF("%s -> DESIGNATED_DISCARD\n",
1066 			    bp->bp_ifp->if_xname);
1067 		}
1068 		break;
1069 	}
1070 
1071 	if (bp->bp_flags & BSTP_PORT_NEWINFO)
1072 		bstp_transmit(bs, bp);
1073 }
1074 
1075 static void
1076 bstp_update_tc(struct bstp_port *bp)
1077 {
1078 	switch (bp->bp_tcstate) {
1079 		case BSTP_TCSTATE_ACTIVE:
1080 			if ((bp->bp_role != BSTP_ROLE_DESIGNATED &&
1081 			    bp->bp_role != BSTP_ROLE_ROOT) || bp->bp_operedge)
1082 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1083 
1084 			if (bp->bp_rcvdtcn)
1085 				bstp_set_port_tc(bp, BSTP_TCSTATE_TCN);
1086 			if (bp->bp_rcvdtc)
1087 				bstp_set_port_tc(bp, BSTP_TCSTATE_TC);
1088 
1089 			if (bp->bp_tc_prop && !bp->bp_operedge)
1090 				bstp_set_port_tc(bp, BSTP_TCSTATE_PROPAG);
1091 
1092 			if (bp->bp_rcvdtca)
1093 				bstp_set_port_tc(bp, BSTP_TCSTATE_ACK);
1094 			break;
1095 
1096 		case BSTP_TCSTATE_INACTIVE:
1097 			if ((bp->bp_state == BSTP_IFSTATE_LEARNING ||
1098 			    bp->bp_state == BSTP_IFSTATE_FORWARDING) &&
1099 			    bp->bp_fdbflush == 0)
1100 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1101 			break;
1102 
1103 		case BSTP_TCSTATE_LEARNING:
1104 			if (bp->bp_rcvdtc || bp->bp_rcvdtcn || bp->bp_rcvdtca ||
1105 			    bp->bp_tc_prop)
1106 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1107 			else if (bp->bp_role != BSTP_ROLE_DESIGNATED &&
1108 				 bp->bp_role != BSTP_ROLE_ROOT &&
1109 				 bp->bp_state == BSTP_IFSTATE_DISCARDING)
1110 				bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1111 
1112 			if ((bp->bp_role == BSTP_ROLE_DESIGNATED ||
1113 			    bp->bp_role == BSTP_ROLE_ROOT) &&
1114 			    bp->bp_state == BSTP_IFSTATE_FORWARDING &&
1115 			    !bp->bp_operedge)
1116 				bstp_set_port_tc(bp, BSTP_TCSTATE_DETECTED);
1117 			break;
1118 
1119 		/* these are transient states and go straight back to ACTIVE */
1120 		case BSTP_TCSTATE_DETECTED:
1121 		case BSTP_TCSTATE_TCN:
1122 		case BSTP_TCSTATE_TC:
1123 		case BSTP_TCSTATE_PROPAG:
1124 		case BSTP_TCSTATE_ACK:
1125 			DPRINTF("Invalid TC state for %s\n",
1126 			    bp->bp_ifp->if_xname);
1127 			break;
1128 	}
1129 
1130 }
1131 
1132 static void
1133 bstp_update_info(struct bstp_port *bp)
1134 {
1135 	struct bstp_state *bs = bp->bp_bs;
1136 
1137 	bp->bp_proposing = 0;
1138 	bp->bp_proposed = 0;
1139 
1140 	if (bp->bp_agreed && !bstp_pdu_bettersame(bp, BSTP_INFO_MINE))
1141 		bp->bp_agreed = 0;
1142 
1143 	if (bp->bp_synced && !bp->bp_agreed) {
1144 		bp->bp_synced = 0;
1145 		bs->bs_allsynced = 0;
1146 	}
1147 
1148 	/* copy the designated pv to the port */
1149 	bp->bp_port_pv = bp->bp_desg_pv;
1150 	bp->bp_port_msg_age = bp->bp_desg_msg_age;
1151 	bp->bp_port_max_age = bp->bp_desg_max_age;
1152 	bp->bp_port_fdelay = bp->bp_desg_fdelay;
1153 	bp->bp_port_htime = bp->bp_desg_htime;
1154 	bp->bp_infois = BSTP_INFO_MINE;
1155 
1156 	/* Set transmit flag but do not immediately send */
1157 	bp->bp_flags |= BSTP_PORT_NEWINFO;
1158 }
1159 
1160 /* set tcprop on every port other than the caller */
1161 static void
1162 bstp_set_other_tcprop(struct bstp_port *bp)
1163 {
1164 	struct bstp_state *bs = bp->bp_bs;
1165 	struct bstp_port *bp2;
1166 
1167 	BSTP_LOCK_ASSERT(bs);
1168 
1169 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1170 		if (bp2 == bp)
1171 			continue;
1172 		bp2->bp_tc_prop = 1;
1173 	}
1174 }
1175 
1176 static void
1177 bstp_set_all_reroot(struct bstp_state *bs)
1178 {
1179 	struct bstp_port *bp;
1180 
1181 	BSTP_LOCK_ASSERT(bs);
1182 
1183 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1184 		bp->bp_reroot = 1;
1185 }
1186 
1187 static void
1188 bstp_set_all_sync(struct bstp_state *bs)
1189 {
1190 	struct bstp_port *bp;
1191 
1192 	BSTP_LOCK_ASSERT(bs);
1193 
1194 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1195 		bp->bp_sync = 1;
1196 		bp->bp_synced = 0;	/* Not explicit in spec */
1197 	}
1198 
1199 	bs->bs_allsynced = 0;
1200 }
1201 
1202 static void
1203 bstp_set_port_state(struct bstp_port *bp, int state)
1204 {
1205 	if (bp->bp_state == state)
1206 		return;
1207 
1208 	bp->bp_state = state;
1209 
1210 	switch (bp->bp_state) {
1211 		case BSTP_IFSTATE_DISCARDING:
1212 			DPRINTF("state changed to DISCARDING on %s\n",
1213 			    bp->bp_ifp->if_xname);
1214 			break;
1215 
1216 		case BSTP_IFSTATE_LEARNING:
1217 			DPRINTF("state changed to LEARNING on %s\n",
1218 			    bp->bp_ifp->if_xname);
1219 
1220 			bstp_timer_start(&bp->bp_forward_delay_timer,
1221 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1222 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1223 			break;
1224 
1225 		case BSTP_IFSTATE_FORWARDING:
1226 			DPRINTF("state changed to FORWARDING on %s\n",
1227 			    bp->bp_ifp->if_xname);
1228 
1229 			bstp_timer_stop(&bp->bp_forward_delay_timer);
1230 			/* Record that we enabled forwarding */
1231 			bp->bp_forward_transitions++;
1232 			break;
1233 	}
1234 
1235 	/* notify the parent bridge */
1236 	taskqueue_enqueue(taskqueue_swi, &bp->bp_statetask);
1237 }
1238 
1239 static void
1240 bstp_set_port_role(struct bstp_port *bp, int role)
1241 {
1242 	struct bstp_state *bs = bp->bp_bs;
1243 
1244 	if (bp->bp_role == role)
1245 		return;
1246 
1247 	/* perform pre-change tasks */
1248 	switch (bp->bp_role) {
1249 		case BSTP_ROLE_DISABLED:
1250 			bstp_timer_start(&bp->bp_forward_delay_timer,
1251 			    bp->bp_desg_max_age);
1252 			break;
1253 
1254 		case BSTP_ROLE_BACKUP:
1255 			bstp_timer_start(&bp->bp_recent_backup_timer,
1256 			    bp->bp_desg_htime * 2);
1257 			/* fall through */
1258 		case BSTP_ROLE_ALTERNATE:
1259 			bstp_timer_start(&bp->bp_forward_delay_timer,
1260 			    bp->bp_desg_fdelay);
1261 			bp->bp_sync = 0;
1262 			bp->bp_synced = 1;
1263 			bp->bp_reroot = 0;
1264 			break;
1265 
1266 		case BSTP_ROLE_ROOT:
1267 			bstp_timer_start(&bp->bp_recent_root_timer,
1268 			    BSTP_DEFAULT_FORWARD_DELAY);
1269 			break;
1270 	}
1271 
1272 	bp->bp_role = role;
1273 	/* clear values not carried between roles */
1274 	bp->bp_proposing = 0;
1275 	bs->bs_allsynced = 0;
1276 
1277 	/* initialise the new role */
1278 	switch (bp->bp_role) {
1279 		case BSTP_ROLE_DISABLED:
1280 		case BSTP_ROLE_ALTERNATE:
1281 		case BSTP_ROLE_BACKUP:
1282 			DPRINTF("%s role -> ALT/BACK/DISABLED\n",
1283 			    bp->bp_ifp->if_xname);
1284 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1285 			bstp_timer_stop(&bp->bp_recent_root_timer);
1286 			bstp_timer_latch(&bp->bp_forward_delay_timer);
1287 			bp->bp_sync = 0;
1288 			bp->bp_synced = 1;
1289 			bp->bp_reroot = 0;
1290 			break;
1291 
1292 		case BSTP_ROLE_ROOT:
1293 			DPRINTF("%s role -> ROOT\n",
1294 			    bp->bp_ifp->if_xname);
1295 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1296 			bstp_timer_latch(&bp->bp_recent_root_timer);
1297 			bp->bp_proposing = 0;
1298 			break;
1299 
1300 		case BSTP_ROLE_DESIGNATED:
1301 			DPRINTF("%s role -> DESIGNATED\n",
1302 			    bp->bp_ifp->if_xname);
1303 			bstp_timer_start(&bp->bp_hello_timer,
1304 			    bp->bp_desg_htime);
1305 			bp->bp_agree = 0;
1306 			break;
1307 	}
1308 
1309 	/* let the TC state know that the role changed */
1310 	bstp_update_tc(bp);
1311 }
1312 
1313 static void
1314 bstp_set_port_proto(struct bstp_port *bp, int proto)
1315 {
1316 	struct bstp_state *bs = bp->bp_bs;
1317 
1318 	/* supported protocol versions */
1319 	switch (proto) {
1320 		case BSTP_PROTO_STP:
1321 			/* we can downgrade protocols only */
1322 			bstp_timer_stop(&bp->bp_migrate_delay_timer);
1323 			/* clear unsupported features */
1324 			bp->bp_operedge = 0;
1325 			/* STP compat mode only uses 16 bits of the 32 */
1326 			if (bp->bp_path_cost > 65535)
1327 				bp->bp_path_cost = 65535;
1328 			break;
1329 
1330 		case BSTP_PROTO_RSTP:
1331 			bstp_timer_start(&bp->bp_migrate_delay_timer,
1332 			    bs->bs_migration_delay);
1333 			break;
1334 
1335 		default:
1336 			DPRINTF("Unsupported STP version %d\n", proto);
1337 			return;
1338 	}
1339 
1340 	bp->bp_protover = proto;
1341 	bp->bp_flags &= ~BSTP_PORT_CANMIGRATE;
1342 }
1343 
1344 static void
1345 bstp_set_port_tc(struct bstp_port *bp, int state)
1346 {
1347 	struct bstp_state *bs = bp->bp_bs;
1348 
1349 	bp->bp_tcstate = state;
1350 
1351 	/* initialise the new state */
1352 	switch (bp->bp_tcstate) {
1353 		case BSTP_TCSTATE_ACTIVE:
1354 			DPRINTF("%s -> TC_ACTIVE\n", bp->bp_ifp->if_xname);
1355 			/* nothing to do */
1356 			break;
1357 
1358 		case BSTP_TCSTATE_INACTIVE:
1359 			bstp_timer_stop(&bp->bp_tc_timer);
1360 			/* flush routes on the parent bridge */
1361 			bp->bp_fdbflush = 1;
1362 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1363 			bp->bp_tc_ack = 0;
1364 			DPRINTF("%s -> TC_INACTIVE\n", bp->bp_ifp->if_xname);
1365 			break;
1366 
1367 		case BSTP_TCSTATE_LEARNING:
1368 			bp->bp_rcvdtc = 0;
1369 			bp->bp_rcvdtcn = 0;
1370 			bp->bp_rcvdtca = 0;
1371 			bp->bp_tc_prop = 0;
1372 			DPRINTF("%s -> TC_LEARNING\n", bp->bp_ifp->if_xname);
1373 			break;
1374 
1375 		case BSTP_TCSTATE_DETECTED:
1376 			bstp_set_timer_tc(bp);
1377 			bstp_set_other_tcprop(bp);
1378 			/* send out notification */
1379 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1380 			bstp_transmit(bs, bp);
1381 			getmicrotime(&bs->bs_last_tc_time);
1382 			DPRINTF("%s -> TC_DETECTED\n", bp->bp_ifp->if_xname);
1383 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1384 			break;
1385 
1386 		case BSTP_TCSTATE_TCN:
1387 			bstp_set_timer_tc(bp);
1388 			DPRINTF("%s -> TC_TCN\n", bp->bp_ifp->if_xname);
1389 			/* fall through */
1390 		case BSTP_TCSTATE_TC:
1391 			bp->bp_rcvdtc = 0;
1392 			bp->bp_rcvdtcn = 0;
1393 			if (bp->bp_role == BSTP_ROLE_DESIGNATED)
1394 				bp->bp_tc_ack = 1;
1395 
1396 			bstp_set_other_tcprop(bp);
1397 			DPRINTF("%s -> TC_TC\n", bp->bp_ifp->if_xname);
1398 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1399 			break;
1400 
1401 		case BSTP_TCSTATE_PROPAG:
1402 			/* flush routes on the parent bridge */
1403 			bp->bp_fdbflush = 1;
1404 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1405 			bp->bp_tc_prop = 0;
1406 			bstp_set_timer_tc(bp);
1407 			DPRINTF("%s -> TC_PROPAG\n", bp->bp_ifp->if_xname);
1408 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1409 			break;
1410 
1411 		case BSTP_TCSTATE_ACK:
1412 			bstp_timer_stop(&bp->bp_tc_timer);
1413 			bp->bp_rcvdtca = 0;
1414 			DPRINTF("%s -> TC_ACK\n", bp->bp_ifp->if_xname);
1415 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1416 			break;
1417 	}
1418 }
1419 
1420 static void
1421 bstp_set_timer_tc(struct bstp_port *bp)
1422 {
1423 	struct bstp_state *bs = bp->bp_bs;
1424 
1425 	if (bp->bp_tc_timer.active)
1426 		return;
1427 
1428 	switch (bp->bp_protover) {
1429 		case BSTP_PROTO_RSTP:
1430 			bstp_timer_start(&bp->bp_tc_timer,
1431 			    bp->bp_desg_htime + BSTP_TICK_VAL);
1432 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1433 			break;
1434 
1435 		case BSTP_PROTO_STP:
1436 			bstp_timer_start(&bp->bp_tc_timer,
1437 			    bs->bs_root_max_age + bs->bs_root_fdelay);
1438 			break;
1439 	}
1440 }
1441 
1442 static void
1443 bstp_set_timer_msgage(struct bstp_port *bp)
1444 {
1445 	if (bp->bp_port_msg_age + BSTP_MESSAGE_AGE_INCR <=
1446 	    bp->bp_port_max_age) {
1447 		bstp_timer_start(&bp->bp_message_age_timer,
1448 		    bp->bp_port_htime * 3);
1449 	} else
1450 		/* expires immediately */
1451 		bstp_timer_start(&bp->bp_message_age_timer, 0);
1452 }
1453 
1454 static int
1455 bstp_rerooted(struct bstp_state *bs, struct bstp_port *bp)
1456 {
1457 	struct bstp_port *bp2;
1458 	int rr_set = 0;
1459 
1460 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1461 		if (bp2 == bp)
1462 			continue;
1463 		if (bp2->bp_recent_root_timer.active) {
1464 			rr_set = 1;
1465 			break;
1466 		}
1467 	}
1468 	return (!rr_set);
1469 }
1470 
1471 int
1472 bstp_set_htime(struct bstp_state *bs, int t)
1473 {
1474 	/* convert seconds to ticks */
1475 	t *=  BSTP_TICK_VAL;
1476 
1477 	/* value can only be changed in leagacy stp mode */
1478 	if (bs->bs_protover != BSTP_PROTO_STP)
1479 		return (EPERM);
1480 
1481 	if (t < BSTP_MIN_HELLO_TIME || t > BSTP_MAX_HELLO_TIME)
1482 		return (EINVAL);
1483 
1484 	BSTP_LOCK(bs);
1485 	bs->bs_bridge_htime = t;
1486 	bstp_reinit(bs);
1487 	BSTP_UNLOCK(bs);
1488 	return (0);
1489 }
1490 
1491 int
1492 bstp_set_fdelay(struct bstp_state *bs, int t)
1493 {
1494 	/* convert seconds to ticks */
1495 	t *= BSTP_TICK_VAL;
1496 
1497 	if (t < BSTP_MIN_FORWARD_DELAY || t > BSTP_MAX_FORWARD_DELAY)
1498 		return (EINVAL);
1499 
1500 	BSTP_LOCK(bs);
1501 	bs->bs_bridge_fdelay = t;
1502 	bstp_reinit(bs);
1503 	BSTP_UNLOCK(bs);
1504 	return (0);
1505 }
1506 
1507 int
1508 bstp_set_maxage(struct bstp_state *bs, int t)
1509 {
1510 	/* convert seconds to ticks */
1511 	t *= BSTP_TICK_VAL;
1512 
1513 	if (t < BSTP_MIN_MAX_AGE || t > BSTP_MAX_MAX_AGE)
1514 		return (EINVAL);
1515 
1516 	BSTP_LOCK(bs);
1517 	bs->bs_bridge_max_age = t;
1518 	bstp_reinit(bs);
1519 	BSTP_UNLOCK(bs);
1520 	return (0);
1521 }
1522 
1523 int
1524 bstp_set_holdcount(struct bstp_state *bs, int count)
1525 {
1526 	struct bstp_port *bp;
1527 
1528 	if (count < BSTP_MIN_HOLD_COUNT ||
1529 	    count > BSTP_MAX_HOLD_COUNT)
1530 		return (EINVAL);
1531 
1532 	BSTP_LOCK(bs);
1533 	bs->bs_txholdcount = count;
1534 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1535 		bp->bp_txcount = 0;
1536 	BSTP_UNLOCK(bs);
1537 	return (0);
1538 }
1539 
1540 int
1541 bstp_set_protocol(struct bstp_state *bs, int proto)
1542 {
1543 	struct bstp_port *bp;
1544 
1545 	switch (proto) {
1546 		/* Supported protocol versions */
1547 		case BSTP_PROTO_STP:
1548 		case BSTP_PROTO_RSTP:
1549 			break;
1550 
1551 		default:
1552 			return (EINVAL);
1553 	}
1554 
1555 	BSTP_LOCK(bs);
1556 	bs->bs_protover = proto;
1557 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
1558 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1559 		/* reinit state */
1560 		bp->bp_infois = BSTP_INFO_DISABLED;
1561 		bp->bp_txcount = 0;
1562 		bstp_set_port_proto(bp, bs->bs_protover);
1563 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
1564 		bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1565 		bstp_timer_stop(&bp->bp_recent_backup_timer);
1566 	}
1567 	bstp_reinit(bs);
1568 	BSTP_UNLOCK(bs);
1569 	return (0);
1570 }
1571 
1572 int
1573 bstp_set_priority(struct bstp_state *bs, int pri)
1574 {
1575 	if (pri < 0 || pri > BSTP_MAX_PRIORITY)
1576 		return (EINVAL);
1577 
1578 	/* Limit to steps of 4096 */
1579 	pri -= pri % 4096;
1580 
1581 	BSTP_LOCK(bs);
1582 	bs->bs_bridge_priority = pri;
1583 	bstp_reinit(bs);
1584 	BSTP_UNLOCK(bs);
1585 	return (0);
1586 }
1587 
1588 int
1589 bstp_set_port_priority(struct bstp_port *bp, int pri)
1590 {
1591 	struct bstp_state *bs = bp->bp_bs;
1592 
1593 	if (pri < 0 || pri > BSTP_MAX_PORT_PRIORITY)
1594 		return (EINVAL);
1595 
1596 	/* Limit to steps of 16 */
1597 	pri -= pri % 16;
1598 
1599 	BSTP_LOCK(bs);
1600 	bp->bp_priority = pri;
1601 	bstp_reinit(bs);
1602 	BSTP_UNLOCK(bs);
1603 	return (0);
1604 }
1605 
1606 int
1607 bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
1608 {
1609 	struct bstp_state *bs = bp->bp_bs;
1610 
1611 	if (path_cost > BSTP_MAX_PATH_COST)
1612 		return (EINVAL);
1613 
1614 	/* STP compat mode only uses 16 bits of the 32 */
1615 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1616 		path_cost = 65535;
1617 
1618 	BSTP_LOCK(bs);
1619 
1620 	if (path_cost == 0) {	/* use auto */
1621 		bp->bp_flags &= ~BSTP_PORT_ADMCOST;
1622 		bp->bp_path_cost = bstp_calc_path_cost(bp);
1623 	} else {
1624 		bp->bp_path_cost = path_cost;
1625 		bp->bp_flags |= BSTP_PORT_ADMCOST;
1626 	}
1627 	bstp_reinit(bs);
1628 	BSTP_UNLOCK(bs);
1629 	return (0);
1630 }
1631 
1632 int
1633 bstp_set_edge(struct bstp_port *bp, int set)
1634 {
1635 	struct bstp_state *bs = bp->bp_bs;
1636 
1637 	BSTP_LOCK(bs);
1638 	if ((bp->bp_operedge = set) == 0)
1639 		bp->bp_flags &= ~BSTP_PORT_ADMEDGE;
1640 	else
1641 		bp->bp_flags |= BSTP_PORT_ADMEDGE;
1642 	BSTP_UNLOCK(bs);
1643 	return (0);
1644 }
1645 
1646 int
1647 bstp_set_autoedge(struct bstp_port *bp, int set)
1648 {
1649 	struct bstp_state *bs = bp->bp_bs;
1650 
1651 	BSTP_LOCK(bs);
1652 	if (set) {
1653 		bp->bp_flags |= BSTP_PORT_AUTOEDGE;
1654 		/* we may be able to transition straight to edge */
1655 		if (bp->bp_edge_delay_timer.active == 0)
1656 			bstp_edge_delay_expiry(bs, bp);
1657 	} else
1658 		bp->bp_flags &= ~BSTP_PORT_AUTOEDGE;
1659 	BSTP_UNLOCK(bs);
1660 	return (0);
1661 }
1662 
1663 int
1664 bstp_set_ptp(struct bstp_port *bp, int set)
1665 {
1666 	struct bstp_state *bs = bp->bp_bs;
1667 
1668 	BSTP_LOCK(bs);
1669 	bp->bp_ptp_link = set;
1670 	BSTP_UNLOCK(bs);
1671 	return (0);
1672 }
1673 
1674 int
1675 bstp_set_autoptp(struct bstp_port *bp, int set)
1676 {
1677 	struct bstp_state *bs = bp->bp_bs;
1678 
1679 	BSTP_LOCK(bs);
1680 	if (set) {
1681 		bp->bp_flags |= BSTP_PORT_AUTOPTP;
1682 		if (bp->bp_role != BSTP_ROLE_DISABLED)
1683 			taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
1684 	} else
1685 		bp->bp_flags &= ~BSTP_PORT_AUTOPTP;
1686 	BSTP_UNLOCK(bs);
1687 	return (0);
1688 }
1689 
1690 /*
1691  * Calculate the path cost according to the link speed.
1692  */
1693 static uint32_t
1694 bstp_calc_path_cost(struct bstp_port *bp)
1695 {
1696 	struct ifnet *ifp = bp->bp_ifp;
1697 	uint32_t path_cost;
1698 
1699 	/* If the priority has been manually set then retain the value */
1700 	if (bp->bp_flags & BSTP_PORT_ADMCOST)
1701 		return bp->bp_path_cost;
1702 
1703 	if (ifp->if_link_state == LINK_STATE_DOWN) {
1704 		/* Recalc when the link comes up again */
1705 		bp->bp_flags |= BSTP_PORT_PNDCOST;
1706 		return (BSTP_DEFAULT_PATH_COST);
1707 	}
1708 
1709 	if (ifp->if_baudrate < 1000)
1710 		return (BSTP_DEFAULT_PATH_COST);
1711 
1712  	/* formula from section 17.14, IEEE Std 802.1D-2004 */
1713 	path_cost = 20000000000ULL / (ifp->if_baudrate / 1000);
1714 
1715 	if (path_cost > BSTP_MAX_PATH_COST)
1716 		path_cost = BSTP_MAX_PATH_COST;
1717 
1718 	/* STP compat mode only uses 16 bits of the 32 */
1719 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1720 		path_cost = 65535;
1721 
1722 	return (path_cost);
1723 }
1724 
1725 /*
1726  * Notify the bridge that a port state has changed, we need to do this from a
1727  * taskqueue to avoid a LOR.
1728  */
1729 static void
1730 bstp_notify_state(void *arg, int pending)
1731 {
1732 	struct bstp_port *bp = (struct bstp_port *)arg;
1733 	struct bstp_state *bs = bp->bp_bs;
1734 
1735 	if (bp->bp_active == 1 && bs->bs_state_cb != NULL)
1736 		(*bs->bs_state_cb)(bp->bp_ifp, bp->bp_state);
1737 }
1738 
1739 /*
1740  * Flush the routes on the bridge port, we need to do this from a
1741  * taskqueue to avoid a LOR.
1742  */
1743 static void
1744 bstp_notify_rtage(void *arg, int pending)
1745 {
1746 	struct bstp_port *bp = (struct bstp_port *)arg;
1747 	struct bstp_state *bs = bp->bp_bs;
1748 	int age = 0;
1749 
1750 	BSTP_LOCK(bs);
1751 	switch (bp->bp_protover) {
1752 		case BSTP_PROTO_STP:
1753 			/* convert to seconds */
1754 			age = bp->bp_desg_fdelay / BSTP_TICK_VAL;
1755 			break;
1756 
1757 		case BSTP_PROTO_RSTP:
1758 			age = 0;
1759 			break;
1760 	}
1761 	BSTP_UNLOCK(bs);
1762 
1763 	if (bp->bp_active == 1 && bs->bs_rtage_cb != NULL)
1764 		(*bs->bs_rtage_cb)(bp->bp_ifp, age);
1765 
1766 	/* flush is complete */
1767 	BSTP_LOCK(bs);
1768 	bp->bp_fdbflush = 0;
1769 	BSTP_UNLOCK(bs);
1770 }
1771 
1772 void
1773 bstp_linkstate(struct bstp_port *bp)
1774 {
1775 	struct bstp_state *bs = bp->bp_bs;
1776 
1777 	if (!bp->bp_active)
1778 		return;
1779 
1780 	bstp_ifupdstatus(bp, 0);
1781 	BSTP_LOCK(bs);
1782 	bstp_update_state(bs, bp);
1783 	BSTP_UNLOCK(bs);
1784 }
1785 
1786 static void
1787 bstp_ifupdstatus(void *arg, int pending)
1788 {
1789 	struct bstp_port *bp = (struct bstp_port *)arg;
1790 	struct bstp_state *bs = bp->bp_bs;
1791 	struct ifnet *ifp = bp->bp_ifp;
1792 	struct ifmediareq ifmr;
1793 	int error, changed;
1794 
1795 	if (!bp->bp_active)
1796 		return;
1797 
1798 	bzero((char *)&ifmr, sizeof(ifmr));
1799 	error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);
1800 
1801 	BSTP_LOCK(bs);
1802 	changed = 0;
1803 	if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1804 		if (ifmr.ifm_status & IFM_ACTIVE) {
1805 			/* A full-duplex link is assumed to be point to point */
1806 			if (bp->bp_flags & BSTP_PORT_AUTOPTP) {
1807 				int fdx;
1808 
1809 				fdx = ifmr.ifm_active & IFM_FDX ? 1 : 0;
1810 				if (bp->bp_ptp_link ^ fdx) {
1811 					bp->bp_ptp_link = fdx;
1812 					changed = 1;
1813 				}
1814 			}
1815 
1816 			/* Calc the cost if the link was down previously */
1817 			if (bp->bp_flags & BSTP_PORT_PNDCOST) {
1818 				uint32_t cost;
1819 
1820 				cost = bstp_calc_path_cost(bp);
1821 				if (bp->bp_path_cost != cost) {
1822 					bp->bp_path_cost = cost;
1823 					changed = 1;
1824 				}
1825 				bp->bp_flags &= ~BSTP_PORT_PNDCOST;
1826 			}
1827 
1828 			if (bp->bp_role == BSTP_ROLE_DISABLED) {
1829 				bstp_enable_port(bs, bp);
1830 				changed = 1;
1831 			}
1832 		} else {
1833 			if (bp->bp_role != BSTP_ROLE_DISABLED) {
1834 				bstp_disable_port(bs, bp);
1835 				changed = 1;
1836 				if ((bp->bp_flags & BSTP_PORT_ADMEDGE) &&
1837 				    bp->bp_protover == BSTP_PROTO_RSTP)
1838 					bp->bp_operedge = 1;
1839 			}
1840 		}
1841 	} else if (bp->bp_infois != BSTP_INFO_DISABLED) {
1842 		bstp_disable_port(bs, bp);
1843 		changed = 1;
1844 	}
1845 	if (changed)
1846 		bstp_assign_roles(bs);
1847 	BSTP_UNLOCK(bs);
1848 }
1849 
1850 static void
1851 bstp_enable_port(struct bstp_state *bs, struct bstp_port *bp)
1852 {
1853 	bp->bp_infois = BSTP_INFO_AGED;
1854 }
1855 
1856 static void
1857 bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
1858 {
1859 	bp->bp_infois = BSTP_INFO_DISABLED;
1860 }
1861 
1862 static void
1863 bstp_tick(void *arg)
1864 {
1865 	struct bstp_state *bs = arg;
1866 	struct bstp_port *bp;
1867 
1868 	BSTP_LOCK_ASSERT(bs);
1869 
1870 	if (bs->bs_running == 0)
1871 		return;
1872 
1873 	CURVNET_SET(bs->bs_vnet);
1874 
1875 	/* poll link events on interfaces that do not support linkstate */
1876 	if (bstp_timer_dectest(&bs->bs_link_timer)) {
1877 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1878 			if (!(bp->bp_ifp->if_capabilities & IFCAP_LINKSTATE))
1879 				taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
1880 		}
1881 		bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
1882 	}
1883 
1884 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1885 		/* no events need to happen for these */
1886 		bstp_timer_dectest(&bp->bp_tc_timer);
1887 		bstp_timer_dectest(&bp->bp_recent_root_timer);
1888 		bstp_timer_dectest(&bp->bp_forward_delay_timer);
1889 		bstp_timer_dectest(&bp->bp_recent_backup_timer);
1890 
1891 		if (bstp_timer_dectest(&bp->bp_hello_timer))
1892 			bstp_hello_timer_expiry(bs, bp);
1893 
1894 		if (bstp_timer_dectest(&bp->bp_message_age_timer))
1895 			bstp_message_age_expiry(bs, bp);
1896 
1897 		if (bstp_timer_dectest(&bp->bp_migrate_delay_timer))
1898 			bstp_migrate_delay_expiry(bs, bp);
1899 
1900 		if (bstp_timer_dectest(&bp->bp_edge_delay_timer))
1901 			bstp_edge_delay_expiry(bs, bp);
1902 
1903 		/* update the various state machines for the port */
1904 		bstp_update_state(bs, bp);
1905 
1906 		if (bp->bp_txcount > 0)
1907 			bp->bp_txcount--;
1908 	}
1909 
1910 	CURVNET_RESTORE();
1911 
1912 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
1913 }
1914 
1915 static void
1916 bstp_timer_start(struct bstp_timer *t, uint16_t v)
1917 {
1918 	t->value = v;
1919 	t->active = 1;
1920 	t->latched = 0;
1921 }
1922 
1923 static void
1924 bstp_timer_stop(struct bstp_timer *t)
1925 {
1926 	t->value = 0;
1927 	t->active = 0;
1928 	t->latched = 0;
1929 }
1930 
1931 static void
1932 bstp_timer_latch(struct bstp_timer *t)
1933 {
1934 	t->latched = 1;
1935 	t->active = 1;
1936 }
1937 
1938 static int
1939 bstp_timer_dectest(struct bstp_timer *t)
1940 {
1941 	if (t->active == 0 || t->latched)
1942 		return (0);
1943 	t->value -= BSTP_TICK_VAL;
1944 	if (t->value <= 0) {
1945 		bstp_timer_stop(t);
1946 		return (1);
1947 	}
1948 	return (0);
1949 }
1950 
1951 static void
1952 bstp_hello_timer_expiry(struct bstp_state *bs, struct bstp_port *bp)
1953 {
1954 	if ((bp->bp_flags & BSTP_PORT_NEWINFO) ||
1955 	    bp->bp_role == BSTP_ROLE_DESIGNATED ||
1956 	    (bp->bp_role == BSTP_ROLE_ROOT &&
1957 	     bp->bp_tc_timer.active == 1)) {
1958 		bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
1959 		bp->bp_flags |= BSTP_PORT_NEWINFO;
1960 		bstp_transmit(bs, bp);
1961 	}
1962 }
1963 
1964 static void
1965 bstp_message_age_expiry(struct bstp_state *bs, struct bstp_port *bp)
1966 {
1967 	if (bp->bp_infois == BSTP_INFO_RECEIVED) {
1968 		bp->bp_infois = BSTP_INFO_AGED;
1969 		bstp_assign_roles(bs);
1970 		DPRINTF("aged info on %s\n", bp->bp_ifp->if_xname);
1971 	}
1972 }
1973 
1974 static void
1975 bstp_migrate_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1976 {
1977 	bp->bp_flags |= BSTP_PORT_CANMIGRATE;
1978 }
1979 
1980 static void
1981 bstp_edge_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1982 {
1983 	if ((bp->bp_flags & BSTP_PORT_AUTOEDGE) &&
1984 	    bp->bp_protover == BSTP_PROTO_RSTP && bp->bp_proposing &&
1985 	    bp->bp_role == BSTP_ROLE_DESIGNATED) {
1986 		bp->bp_operedge = 1;
1987 		DPRINTF("%s -> edge port\n", bp->bp_ifp->if_xname);
1988 	}
1989 }
1990 
1991 static int
1992 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
1993 {
1994 	int i, d;
1995 
1996 	for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
1997 		d = ((int)a[i]) - ((int)b[i]);
1998 	}
1999 
2000 	return (d);
2001 }
2002 
2003 /*
2004  * compare the bridge address component of the bridgeid
2005  */
2006 static int
2007 bstp_same_bridgeid(uint64_t id1, uint64_t id2)
2008 {
2009 	u_char addr1[ETHER_ADDR_LEN];
2010 	u_char addr2[ETHER_ADDR_LEN];
2011 
2012 	PV2ADDR(id1, addr1);
2013 	PV2ADDR(id2, addr2);
2014 
2015 	if (bstp_addr_cmp(addr1, addr2) == 0)
2016 		return (1);
2017 
2018 	return (0);
2019 }
2020 
2021 void
2022 bstp_reinit(struct bstp_state *bs)
2023 {
2024 	struct epoch_tracker et;
2025 	struct bstp_port *bp;
2026 	struct ifnet *ifp, *mif;
2027 	u_char *e_addr;
2028 	void *bridgeptr;
2029 	static const u_char llzero[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */
2030 
2031 	BSTP_LOCK_ASSERT(bs);
2032 
2033 	if (LIST_EMPTY(&bs->bs_bplist))
2034 		goto disablestp;
2035 
2036 	mif = NULL;
2037 	bridgeptr = LIST_FIRST(&bs->bs_bplist)->bp_ifp->if_bridge;
2038 	KASSERT(bridgeptr != NULL, ("Invalid bridge pointer"));
2039 	/*
2040 	 * Search through the Ethernet adapters and find the one with the
2041 	 * lowest value. Make sure the adapter which we take the MAC address
2042 	 * from is part of this bridge, so we can have more than one independent
2043 	 * bridges in the same STP domain.
2044 	 */
2045 	NET_EPOCH_ENTER(et);
2046 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2047 		if (ifp->if_type != IFT_ETHER)
2048 			continue;	/* Not Ethernet */
2049 
2050 		if (ifp->if_bridge != bridgeptr)
2051 			continue;	/* Not part of our bridge */
2052 
2053 		if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
2054 			continue;	/* No mac address set */
2055 
2056 		if (mif == NULL) {
2057 			mif = ifp;
2058 			continue;
2059 		}
2060 		if (bstp_addr_cmp(IF_LLADDR(ifp), IF_LLADDR(mif)) < 0) {
2061 			mif = ifp;
2062 			continue;
2063 		}
2064 	}
2065 	NET_EPOCH_EXIT(et);
2066 	if (mif == NULL)
2067 		goto disablestp;
2068 
2069 	e_addr = IF_LLADDR(mif);
2070 	bs->bs_bridge_pv.pv_dbridge_id =
2071 	    (((uint64_t)bs->bs_bridge_priority) << 48) |
2072 	    (((uint64_t)e_addr[0]) << 40) |
2073 	    (((uint64_t)e_addr[1]) << 32) |
2074 	    (((uint64_t)e_addr[2]) << 24) |
2075 	    (((uint64_t)e_addr[3]) << 16) |
2076 	    (((uint64_t)e_addr[4]) << 8) |
2077 	    (((uint64_t)e_addr[5]));
2078 
2079 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2080 	bs->bs_bridge_pv.pv_cost = 0;
2081 	bs->bs_bridge_pv.pv_dport_id = 0;
2082 	bs->bs_bridge_pv.pv_port_id = 0;
2083 
2084 	if (bs->bs_running && callout_pending(&bs->bs_bstpcallout) == 0)
2085 		callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2086 
2087 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2088 		bp->bp_port_id = (bp->bp_priority << 8) |
2089 		    (bp->bp_ifp->if_index  & 0xfff);
2090 		taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
2091 	}
2092 
2093 	bstp_assign_roles(bs);
2094 	bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
2095 	return;
2096 
2097 disablestp:
2098 	/* Set the bridge and root id (lower bits) to zero */
2099 	bs->bs_bridge_pv.pv_dbridge_id =
2100 	    ((uint64_t)bs->bs_bridge_priority) << 48;
2101 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2102 	bs->bs_root_pv = bs->bs_bridge_pv;
2103 	/* Disable any remaining ports, they will have no MAC address */
2104 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2105 		bp->bp_infois = BSTP_INFO_DISABLED;
2106 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2107 	}
2108 	callout_stop(&bs->bs_bstpcallout);
2109 }
2110 
2111 static int
2112 bstp_modevent(module_t mod, int type, void *data)
2113 {
2114 	switch (type) {
2115 	case MOD_LOAD:
2116 		mtx_init(&bstp_list_mtx, "bridgestp list", NULL, MTX_DEF);
2117 		LIST_INIT(&bstp_list);
2118 		break;
2119 	case MOD_UNLOAD:
2120 		mtx_destroy(&bstp_list_mtx);
2121 		break;
2122 	default:
2123 		return (EOPNOTSUPP);
2124 	}
2125 	return (0);
2126 }
2127 
2128 static moduledata_t bstp_mod = {
2129 	"bridgestp",
2130 	bstp_modevent,
2131 	0
2132 };
2133 
2134 DECLARE_MODULE(bridgestp, bstp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2135 MODULE_VERSION(bridgestp, 1);
2136 
2137 void
2138 bstp_attach(struct bstp_state *bs, struct bstp_cb_ops *cb)
2139 {
2140 	BSTP_LOCK_INIT(bs);
2141 	callout_init_mtx(&bs->bs_bstpcallout, &bs->bs_mtx, 0);
2142 	LIST_INIT(&bs->bs_bplist);
2143 
2144 	bs->bs_bridge_max_age = BSTP_DEFAULT_MAX_AGE;
2145 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
2146 	bs->bs_bridge_fdelay = BSTP_DEFAULT_FORWARD_DELAY;
2147 	bs->bs_bridge_priority = BSTP_DEFAULT_BRIDGE_PRIORITY;
2148 	bs->bs_hold_time = BSTP_DEFAULT_HOLD_TIME;
2149 	bs->bs_migration_delay = BSTP_DEFAULT_MIGRATE_DELAY;
2150 	bs->bs_txholdcount = BSTP_DEFAULT_HOLD_COUNT;
2151 	bs->bs_protover = BSTP_PROTO_RSTP;
2152 	bs->bs_state_cb = cb->bcb_state;
2153 	bs->bs_rtage_cb = cb->bcb_rtage;
2154 	bs->bs_vnet = curvnet;
2155 
2156 	getmicrotime(&bs->bs_last_tc_time);
2157 
2158 	mtx_lock(&bstp_list_mtx);
2159 	LIST_INSERT_HEAD(&bstp_list, bs, bs_list);
2160 	mtx_unlock(&bstp_list_mtx);
2161 }
2162 
2163 void
2164 bstp_detach(struct bstp_state *bs)
2165 {
2166 	KASSERT(LIST_EMPTY(&bs->bs_bplist), ("bstp still active"));
2167 
2168 	mtx_lock(&bstp_list_mtx);
2169 	LIST_REMOVE(bs, bs_list);
2170 	mtx_unlock(&bstp_list_mtx);
2171 	callout_drain(&bs->bs_bstpcallout);
2172 	BSTP_LOCK_DESTROY(bs);
2173 }
2174 
2175 void
2176 bstp_init(struct bstp_state *bs)
2177 {
2178 	BSTP_LOCK(bs);
2179 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2180 	bs->bs_running = 1;
2181 	bstp_reinit(bs);
2182 	BSTP_UNLOCK(bs);
2183 }
2184 
2185 void
2186 bstp_stop(struct bstp_state *bs)
2187 {
2188 	struct bstp_port *bp;
2189 
2190 	BSTP_LOCK(bs);
2191 
2192 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
2193 		bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2194 
2195 	bs->bs_running = 0;
2196 	callout_stop(&bs->bs_bstpcallout);
2197 	BSTP_UNLOCK(bs);
2198 }
2199 
2200 int
2201 bstp_create(struct bstp_state *bs, struct bstp_port *bp, struct ifnet *ifp)
2202 {
2203 	bzero(bp, sizeof(struct bstp_port));
2204 
2205 	BSTP_LOCK(bs);
2206 	bp->bp_ifp = ifp;
2207 	bp->bp_bs = bs;
2208 	bp->bp_priority = BSTP_DEFAULT_PORT_PRIORITY;
2209 	TASK_INIT(&bp->bp_statetask, 0, bstp_notify_state, bp);
2210 	TASK_INIT(&bp->bp_rtagetask, 0, bstp_notify_rtage, bp);
2211 	TASK_INIT(&bp->bp_mediatask, 0, bstp_ifupdstatus, bp);
2212 
2213 	/* Init state */
2214 	bp->bp_infois = BSTP_INFO_DISABLED;
2215 	bp->bp_flags = BSTP_PORT_AUTOEDGE|BSTP_PORT_AUTOPTP;
2216 	bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2217 	bstp_set_port_proto(bp, bs->bs_protover);
2218 	bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2219 	bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
2220 	bp->bp_path_cost = bstp_calc_path_cost(bp);
2221 	BSTP_UNLOCK(bs);
2222 	return (0);
2223 }
2224 
2225 int
2226 bstp_enable(struct bstp_port *bp)
2227 {
2228 	struct bstp_state *bs = bp->bp_bs;
2229 	struct ifnet *ifp = bp->bp_ifp;
2230 
2231 	KASSERT(bp->bp_active == 0, ("already a bstp member"));
2232 
2233 	switch (ifp->if_type) {
2234 		case IFT_ETHER:	/* These can do spanning tree. */
2235 			break;
2236 		default:
2237 			/* Nothing else can. */
2238 			return (EINVAL);
2239 	}
2240 
2241 	BSTP_LOCK(bs);
2242 	LIST_INSERT_HEAD(&bs->bs_bplist, bp, bp_next);
2243 	bp->bp_active = 1;
2244 	bp->bp_flags |= BSTP_PORT_NEWINFO;
2245 	bstp_reinit(bs);
2246 	bstp_update_roles(bs, bp);
2247 	BSTP_UNLOCK(bs);
2248 	return (0);
2249 }
2250 
2251 void
2252 bstp_disable(struct bstp_port *bp)
2253 {
2254 	struct bstp_state *bs = bp->bp_bs;
2255 
2256 	KASSERT(bp->bp_active == 1, ("not a bstp member"));
2257 
2258 	BSTP_LOCK(bs);
2259 	bstp_disable_port(bs, bp);
2260 	LIST_REMOVE(bp, bp_next);
2261 	bp->bp_active = 0;
2262 	bstp_reinit(bs);
2263 	BSTP_UNLOCK(bs);
2264 }
2265 
2266 /*
2267  * The bstp_port structure is about to be freed by the parent bridge.
2268  */
2269 void
2270 bstp_destroy(struct bstp_port *bp)
2271 {
2272 	KASSERT(bp->bp_active == 0, ("port is still attached"));
2273 	taskqueue_drain(taskqueue_swi, &bp->bp_statetask);
2274 	taskqueue_drain(taskqueue_swi, &bp->bp_rtagetask);
2275 	taskqueue_drain(taskqueue_swi, &bp->bp_mediatask);
2276 
2277 	if (bp->bp_bs->bs_root_port == bp)
2278 		bstp_assign_roles(bp->bp_bs);
2279 }
2280