xref: /freebsd/sys/net/bridgestp.c (revision 1c05a6ea6b849ff95e539c31adea887c644a6a01)
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 <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/callout.h>
48 #include <sys/module.h>
49 #include <sys/proc.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/taskqueue.h>
53 
54 #include <net/if.h>
55 #include <net/if_var.h>
56 #include <net/if_dl.h>
57 #include <net/if_types.h>
58 #include <net/if_llc.h>
59 #include <net/if_media.h>
60 #include <net/vnet.h>
61 
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/in_var.h>
65 #include <netinet/if_ether.h>
66 #include <net/bridgestp.h>
67 
68 #ifdef	BRIDGESTP_DEBUG
69 #define	DPRINTF(fmt, arg...)	printf("bstp: " fmt, ##arg)
70 #else
71 #define	DPRINTF(fmt, arg...)	(void)0
72 #endif
73 
74 #define	PV2ADDR(pv, eaddr)	do {		\
75 	eaddr[0] = pv >> 40;			\
76 	eaddr[1] = pv >> 32;			\
77 	eaddr[2] = pv >> 24;			\
78 	eaddr[3] = pv >> 16;			\
79 	eaddr[4] = pv >> 8;			\
80 	eaddr[5] = pv >> 0;			\
81 } while (0)
82 
83 #define	INFO_BETTER	1
84 #define	INFO_SAME	0
85 #define	INFO_WORSE	-1
86 
87 const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
88 
89 LIST_HEAD(, bstp_state) bstp_list;
90 static struct mtx	bstp_list_mtx;
91 
92 static void	bstp_transmit(struct bstp_state *, struct bstp_port *);
93 static void	bstp_transmit_bpdu(struct bstp_state *, struct bstp_port *);
94 static void	bstp_transmit_tcn(struct bstp_state *, struct bstp_port *);
95 static void	bstp_decode_bpdu(struct bstp_port *, struct bstp_cbpdu *,
96 		    struct bstp_config_unit *);
97 static void	bstp_send_bpdu(struct bstp_state *, struct bstp_port *,
98 		    struct bstp_cbpdu *);
99 static int	bstp_pdu_flags(struct bstp_port *);
100 static void	bstp_received_stp(struct bstp_state *, struct bstp_port *,
101 		    struct mbuf **, struct bstp_tbpdu *);
102 static void	bstp_received_rstp(struct bstp_state *, struct bstp_port *,
103 		    struct mbuf **, struct bstp_tbpdu *);
104 static void	bstp_received_tcn(struct bstp_state *, struct bstp_port *,
105 		    struct bstp_tcn_unit *);
106 static void	bstp_received_bpdu(struct bstp_state *, struct bstp_port *,
107 		    struct bstp_config_unit *);
108 static int	bstp_pdu_rcvtype(struct bstp_port *, struct bstp_config_unit *);
109 static int	bstp_pdu_bettersame(struct bstp_port *, int);
110 static int	bstp_info_cmp(struct bstp_pri_vector *,
111 		    struct bstp_pri_vector *);
112 static int	bstp_info_superior(struct bstp_pri_vector *,
113 		    struct bstp_pri_vector *);
114 static void	bstp_assign_roles(struct bstp_state *);
115 static void	bstp_update_roles(struct bstp_state *, struct bstp_port *);
116 static void	bstp_update_state(struct bstp_state *, struct bstp_port *);
117 static void	bstp_update_tc(struct bstp_port *);
118 static void	bstp_update_info(struct bstp_port *);
119 static void	bstp_set_other_tcprop(struct bstp_port *);
120 static void	bstp_set_all_reroot(struct bstp_state *);
121 static void	bstp_set_all_sync(struct bstp_state *);
122 static void	bstp_set_port_state(struct bstp_port *, int);
123 static void	bstp_set_port_role(struct bstp_port *, int);
124 static void	bstp_set_port_proto(struct bstp_port *, int);
125 static void	bstp_set_port_tc(struct bstp_port *, int);
126 static void	bstp_set_timer_tc(struct bstp_port *);
127 static void	bstp_set_timer_msgage(struct bstp_port *);
128 static int	bstp_rerooted(struct bstp_state *, struct bstp_port *);
129 static uint32_t	bstp_calc_path_cost(struct bstp_port *);
130 static void	bstp_notify_state(void *, int);
131 static void	bstp_notify_rtage(void *, int);
132 static void	bstp_ifupdstatus(void *, int);
133 static void	bstp_enable_port(struct bstp_state *, struct bstp_port *);
134 static void	bstp_disable_port(struct bstp_state *, struct bstp_port *);
135 static void	bstp_tick(void *);
136 static void	bstp_timer_start(struct bstp_timer *, uint16_t);
137 static void	bstp_timer_stop(struct bstp_timer *);
138 static void	bstp_timer_latch(struct bstp_timer *);
139 static int	bstp_timer_dectest(struct bstp_timer *);
140 static void	bstp_hello_timer_expiry(struct bstp_state *,
141 		    struct bstp_port *);
142 static void	bstp_message_age_expiry(struct bstp_state *,
143 		    struct bstp_port *);
144 static void	bstp_migrate_delay_expiry(struct bstp_state *,
145 		    struct bstp_port *);
146 static void	bstp_edge_delay_expiry(struct bstp_state *,
147 		    struct bstp_port *);
148 static int	bstp_addr_cmp(const uint8_t *, const uint8_t *);
149 static int	bstp_same_bridgeid(uint64_t, uint64_t);
150 static void	bstp_reinit(struct bstp_state *);
151 
152 static void
153 bstp_transmit(struct bstp_state *bs, struct bstp_port *bp)
154 {
155 	if (bs->bs_running == 0)
156 		return;
157 
158 	/*
159 	 * a PDU can only be sent if we have tx quota left and the
160 	 * hello timer is running.
161 	 */
162 	if (bp->bp_hello_timer.active == 0) {
163 		/* Test if it needs to be reset */
164 		bstp_hello_timer_expiry(bs, bp);
165 		return;
166 	}
167 	if (bp->bp_txcount > bs->bs_txholdcount)
168 		/* Ran out of karma */
169 		return;
170 
171 	if (bp->bp_protover == BSTP_PROTO_RSTP) {
172 		bstp_transmit_bpdu(bs, bp);
173 		bp->bp_tc_ack = 0;
174 	} else { /* STP */
175 		switch (bp->bp_role) {
176 			case BSTP_ROLE_DESIGNATED:
177 				bstp_transmit_bpdu(bs, bp);
178 				bp->bp_tc_ack = 0;
179 				break;
180 
181 			case BSTP_ROLE_ROOT:
182 				bstp_transmit_tcn(bs, bp);
183 				break;
184 		}
185 	}
186 	bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
187 	bp->bp_flags &= ~BSTP_PORT_NEWINFO;
188 }
189 
190 static void
191 bstp_transmit_bpdu(struct bstp_state *bs, struct bstp_port *bp)
192 {
193 	struct bstp_cbpdu bpdu;
194 
195 	BSTP_LOCK_ASSERT(bs);
196 
197 	bpdu.cbu_rootpri = htons(bp->bp_desg_pv.pv_root_id >> 48);
198 	PV2ADDR(bp->bp_desg_pv.pv_root_id, bpdu.cbu_rootaddr);
199 
200 	bpdu.cbu_rootpathcost = htonl(bp->bp_desg_pv.pv_cost);
201 
202 	bpdu.cbu_bridgepri = htons(bp->bp_desg_pv.pv_dbridge_id >> 48);
203 	PV2ADDR(bp->bp_desg_pv.pv_dbridge_id, bpdu.cbu_bridgeaddr);
204 
205 	bpdu.cbu_portid = htons(bp->bp_port_id);
206 	bpdu.cbu_messageage = htons(bp->bp_desg_msg_age);
207 	bpdu.cbu_maxage = htons(bp->bp_desg_max_age);
208 	bpdu.cbu_hellotime = htons(bp->bp_desg_htime);
209 	bpdu.cbu_forwarddelay = htons(bp->bp_desg_fdelay);
210 
211 	bpdu.cbu_flags = bstp_pdu_flags(bp);
212 
213 	switch (bp->bp_protover) {
214 		case BSTP_PROTO_STP:
215 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_CFG;
216 			break;
217 
218 		case BSTP_PROTO_RSTP:
219 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_RSTP;
220 			break;
221 	}
222 
223 	bstp_send_bpdu(bs, bp, &bpdu);
224 }
225 
226 static void
227 bstp_transmit_tcn(struct bstp_state *bs, struct bstp_port *bp)
228 {
229 	struct bstp_tbpdu bpdu;
230 	struct ifnet *ifp = bp->bp_ifp;
231 	struct ether_header *eh;
232 	struct mbuf *m;
233 
234 	KASSERT(bp == bs->bs_root_port, ("%s: bad root port\n", __func__));
235 
236 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
237 		return;
238 
239 	m = m_gethdr(M_NOWAIT, MT_DATA);
240 	if (m == NULL)
241 		return;
242 
243 	m->m_pkthdr.rcvif = ifp;
244 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
245 	m->m_len = m->m_pkthdr.len;
246 
247 	eh = mtod(m, struct ether_header *);
248 
249 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
250 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
251 	eh->ether_type = htons(sizeof(bpdu));
252 
253 	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
254 	bpdu.tbu_ctl = LLC_UI;
255 	bpdu.tbu_protoid = 0;
256 	bpdu.tbu_protover = 0;
257 	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
258 
259 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
260 
261 	bp->bp_txcount++;
262 	ifp->if_transmit(ifp, m);
263 }
264 
265 static void
266 bstp_decode_bpdu(struct bstp_port *bp, struct bstp_cbpdu *cpdu,
267     struct bstp_config_unit *cu)
268 {
269 	int flags;
270 
271 	cu->cu_pv.pv_root_id =
272 	    (((uint64_t)ntohs(cpdu->cbu_rootpri)) << 48) |
273 	    (((uint64_t)cpdu->cbu_rootaddr[0]) << 40) |
274 	    (((uint64_t)cpdu->cbu_rootaddr[1]) << 32) |
275 	    (((uint64_t)cpdu->cbu_rootaddr[2]) << 24) |
276 	    (((uint64_t)cpdu->cbu_rootaddr[3]) << 16) |
277 	    (((uint64_t)cpdu->cbu_rootaddr[4]) << 8) |
278 	    (((uint64_t)cpdu->cbu_rootaddr[5]) << 0);
279 
280 	cu->cu_pv.pv_dbridge_id =
281 	    (((uint64_t)ntohs(cpdu->cbu_bridgepri)) << 48) |
282 	    (((uint64_t)cpdu->cbu_bridgeaddr[0]) << 40) |
283 	    (((uint64_t)cpdu->cbu_bridgeaddr[1]) << 32) |
284 	    (((uint64_t)cpdu->cbu_bridgeaddr[2]) << 24) |
285 	    (((uint64_t)cpdu->cbu_bridgeaddr[3]) << 16) |
286 	    (((uint64_t)cpdu->cbu_bridgeaddr[4]) << 8) |
287 	    (((uint64_t)cpdu->cbu_bridgeaddr[5]) << 0);
288 
289 	cu->cu_pv.pv_cost = ntohl(cpdu->cbu_rootpathcost);
290 	cu->cu_message_age = ntohs(cpdu->cbu_messageage);
291 	cu->cu_max_age = ntohs(cpdu->cbu_maxage);
292 	cu->cu_hello_time = ntohs(cpdu->cbu_hellotime);
293 	cu->cu_forward_delay = ntohs(cpdu->cbu_forwarddelay);
294 	cu->cu_pv.pv_dport_id = ntohs(cpdu->cbu_portid);
295 	cu->cu_pv.pv_port_id = bp->bp_port_id;
296 	cu->cu_message_type = cpdu->cbu_bpdutype;
297 
298 	/* Strip off unused flags in STP mode */
299 	flags = cpdu->cbu_flags;
300 	switch (cpdu->cbu_protover) {
301 		case BSTP_PROTO_STP:
302 			flags &= BSTP_PDU_STPMASK;
303 			/* A STP BPDU explicitly conveys a Designated Port */
304 			cu->cu_role = BSTP_ROLE_DESIGNATED;
305 			break;
306 
307 		case BSTP_PROTO_RSTP:
308 			flags &= BSTP_PDU_RSTPMASK;
309 			break;
310 	}
311 
312 	cu->cu_topology_change_ack =
313 		(flags & BSTP_PDU_F_TCA) ? 1 : 0;
314 	cu->cu_proposal =
315 		(flags & BSTP_PDU_F_P) ? 1 : 0;
316 	cu->cu_agree =
317 		(flags & BSTP_PDU_F_A) ? 1 : 0;
318 	cu->cu_learning =
319 		(flags & BSTP_PDU_F_L) ? 1 : 0;
320 	cu->cu_forwarding =
321 		(flags & BSTP_PDU_F_F) ? 1 : 0;
322 	cu->cu_topology_change =
323 		(flags & BSTP_PDU_F_TC) ? 1 : 0;
324 
325 	switch ((flags & BSTP_PDU_PRMASK) >> BSTP_PDU_PRSHIFT) {
326 		case BSTP_PDU_F_ROOT:
327 			cu->cu_role = BSTP_ROLE_ROOT;
328 			break;
329 		case BSTP_PDU_F_ALT:
330 			cu->cu_role = BSTP_ROLE_ALTERNATE;
331 			break;
332 		case BSTP_PDU_F_DESG:
333 			cu->cu_role = BSTP_ROLE_DESIGNATED;
334 			break;
335 	}
336 }
337 
338 static void
339 bstp_send_bpdu(struct bstp_state *bs, struct bstp_port *bp,
340     struct bstp_cbpdu *bpdu)
341 {
342 	struct ifnet *ifp;
343 	struct mbuf *m;
344 	struct ether_header *eh;
345 
346 	BSTP_LOCK_ASSERT(bs);
347 
348 	ifp = bp->bp_ifp;
349 
350 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
351 		return;
352 
353 	m = m_gethdr(M_NOWAIT, MT_DATA);
354 	if (m == NULL)
355 		return;
356 
357 	eh = mtod(m, struct ether_header *);
358 
359 	bpdu->cbu_ssap = bpdu->cbu_dsap = LLC_8021D_LSAP;
360 	bpdu->cbu_ctl = LLC_UI;
361 	bpdu->cbu_protoid = htons(BSTP_PROTO_ID);
362 
363 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
364 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
365 
366 	switch (bpdu->cbu_bpdutype) {
367 		case BSTP_MSGTYPE_CFG:
368 			bpdu->cbu_protover = BSTP_PROTO_STP;
369 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_STP_LEN;
370 			eh->ether_type = htons(BSTP_BPDU_STP_LEN);
371 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
372 			    BSTP_BPDU_STP_LEN);
373 			break;
374 
375 		case BSTP_MSGTYPE_RSTP:
376 			bpdu->cbu_protover = BSTP_PROTO_RSTP;
377 			bpdu->cbu_versionlen = htons(0);
378 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_RSTP_LEN;
379 			eh->ether_type = htons(BSTP_BPDU_RSTP_LEN);
380 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
381 			    BSTP_BPDU_RSTP_LEN);
382 			break;
383 
384 		default:
385 			panic("not implemented");
386 	}
387 	m->m_pkthdr.rcvif = ifp;
388 	m->m_len = m->m_pkthdr.len;
389 
390 	bp->bp_txcount++;
391 	ifp->if_transmit(ifp, m);
392 }
393 
394 static int
395 bstp_pdu_flags(struct bstp_port *bp)
396 {
397 	int flags = 0;
398 
399 	if (bp->bp_proposing && bp->bp_state != BSTP_IFSTATE_FORWARDING)
400 		flags |= BSTP_PDU_F_P;
401 
402 	if (bp->bp_agree)
403 		flags |= BSTP_PDU_F_A;
404 
405 	if (bp->bp_tc_timer.active)
406 		flags |= BSTP_PDU_F_TC;
407 
408 	if (bp->bp_tc_ack)
409 		flags |= BSTP_PDU_F_TCA;
410 
411 	switch (bp->bp_state) {
412 		case BSTP_IFSTATE_LEARNING:
413 			flags |= BSTP_PDU_F_L;
414 			break;
415 
416 		case BSTP_IFSTATE_FORWARDING:
417 			flags |= (BSTP_PDU_F_L | BSTP_PDU_F_F);
418 			break;
419 	}
420 
421 	switch (bp->bp_role) {
422 		case BSTP_ROLE_ROOT:
423 			flags |=
424 				(BSTP_PDU_F_ROOT << BSTP_PDU_PRSHIFT);
425 			break;
426 
427 		case BSTP_ROLE_ALTERNATE:
428 		case BSTP_ROLE_BACKUP:	/* fall through */
429 			flags |=
430 				(BSTP_PDU_F_ALT << BSTP_PDU_PRSHIFT);
431 			break;
432 
433 		case BSTP_ROLE_DESIGNATED:
434 			flags |=
435 				(BSTP_PDU_F_DESG << BSTP_PDU_PRSHIFT);
436 			break;
437 	}
438 
439 	/* Strip off unused flags in either mode */
440 	switch (bp->bp_protover) {
441 		case BSTP_PROTO_STP:
442 			flags &= BSTP_PDU_STPMASK;
443 			break;
444 		case BSTP_PROTO_RSTP:
445 			flags &= BSTP_PDU_RSTPMASK;
446 			break;
447 	}
448 	return (flags);
449 }
450 
451 void
452 bstp_input(struct bstp_port *bp, struct ifnet *ifp, struct mbuf *m)
453 {
454 	struct bstp_state *bs = bp->bp_bs;
455 	struct ether_header *eh;
456 	struct bstp_tbpdu tpdu;
457 	uint16_t len;
458 
459 	if (bp->bp_active == 0) {
460 		m_freem(m);
461 		return;
462 	}
463 
464 	BSTP_LOCK(bs);
465 
466 	eh = mtod(m, struct ether_header *);
467 
468 	len = ntohs(eh->ether_type);
469 	if (len < sizeof(tpdu))
470 		goto out;
471 
472 	m_adj(m, ETHER_HDR_LEN);
473 
474 	if (m->m_pkthdr.len > len)
475 		m_adj(m, len - m->m_pkthdr.len);
476 	if (m->m_len < sizeof(tpdu) &&
477 	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
478 		goto out;
479 
480 	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
481 
482 	/* basic packet checks */
483 	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
484 	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
485 	    tpdu.tbu_ctl != LLC_UI)
486 		goto out;
487 	if (tpdu.tbu_protoid != BSTP_PROTO_ID)
488 		goto out;
489 
490 	/*
491 	 * We can treat later versions of the PDU as the same as the maximum
492 	 * version we implement. All additional parameters/flags are ignored.
493 	 */
494 	if (tpdu.tbu_protover > BSTP_PROTO_MAX)
495 		tpdu.tbu_protover = BSTP_PROTO_MAX;
496 
497 	if (tpdu.tbu_protover != bp->bp_protover) {
498 		/*
499 		 * Wait for the migration delay timer to expire before changing
500 		 * protocol version to avoid flip-flops.
501 		 */
502 		if (bp->bp_flags & BSTP_PORT_CANMIGRATE)
503 			bstp_set_port_proto(bp, tpdu.tbu_protover);
504 		else
505 			goto out;
506 	}
507 
508 	/* Clear operedge upon receiving a PDU on the port */
509 	bp->bp_operedge = 0;
510 	bstp_timer_start(&bp->bp_edge_delay_timer,
511 	    BSTP_DEFAULT_MIGRATE_DELAY);
512 
513 	switch (tpdu.tbu_protover) {
514 		case BSTP_PROTO_STP:
515 			bstp_received_stp(bs, bp, &m, &tpdu);
516 			break;
517 
518 		case BSTP_PROTO_RSTP:
519 			bstp_received_rstp(bs, bp, &m, &tpdu);
520 			break;
521 	}
522 out:
523 	BSTP_UNLOCK(bs);
524 	if (m)
525 		m_freem(m);
526 }
527 
528 static void
529 bstp_received_stp(struct bstp_state *bs, struct bstp_port *bp,
530     struct mbuf **mp, struct bstp_tbpdu *tpdu)
531 {
532 	struct bstp_cbpdu cpdu;
533 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
534 	struct bstp_tcn_unit tu;
535 
536 	switch (tpdu->tbu_bpdutype) {
537 	case BSTP_MSGTYPE_TCN:
538 		tu.tu_message_type = tpdu->tbu_bpdutype;
539 		bstp_received_tcn(bs, bp, &tu);
540 		break;
541 	case BSTP_MSGTYPE_CFG:
542 		if ((*mp)->m_len < BSTP_BPDU_STP_LEN &&
543 		    (*mp = m_pullup(*mp, BSTP_BPDU_STP_LEN)) == NULL)
544 			return;
545 		memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_STP_LEN);
546 
547 		bstp_decode_bpdu(bp, &cpdu, cu);
548 		bstp_received_bpdu(bs, bp, cu);
549 		break;
550 	}
551 }
552 
553 static void
554 bstp_received_rstp(struct bstp_state *bs, struct bstp_port *bp,
555     struct mbuf **mp, struct bstp_tbpdu *tpdu)
556 {
557 	struct bstp_cbpdu cpdu;
558 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
559 
560 	if (tpdu->tbu_bpdutype != BSTP_MSGTYPE_RSTP)
561 		return;
562 
563 	if ((*mp)->m_len < BSTP_BPDU_RSTP_LEN &&
564 	    (*mp = m_pullup(*mp, BSTP_BPDU_RSTP_LEN)) == NULL)
565 		return;
566 	memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_RSTP_LEN);
567 
568 	bstp_decode_bpdu(bp, &cpdu, cu);
569 	bstp_received_bpdu(bs, bp, cu);
570 }
571 
572 static void
573 bstp_received_tcn(struct bstp_state *bs, struct bstp_port *bp,
574     struct bstp_tcn_unit *tcn)
575 {
576 	bp->bp_rcvdtcn = 1;
577 	bstp_update_tc(bp);
578 }
579 
580 static void
581 bstp_received_bpdu(struct bstp_state *bs, struct bstp_port *bp,
582     struct bstp_config_unit *cu)
583 {
584 	int type;
585 
586 	BSTP_LOCK_ASSERT(bs);
587 
588 	/* We need to have transitioned to INFO_MINE before proceeding */
589 	switch (bp->bp_infois) {
590 		case BSTP_INFO_DISABLED:
591 		case BSTP_INFO_AGED:
592 			return;
593 	}
594 
595 	type = bstp_pdu_rcvtype(bp, cu);
596 
597 	switch (type) {
598 		case BSTP_PDU_SUPERIOR:
599 			bs->bs_allsynced = 0;
600 			bp->bp_agreed = 0;
601 			bp->bp_proposing = 0;
602 
603 			if (cu->cu_proposal && cu->cu_forwarding == 0)
604 				bp->bp_proposed = 1;
605 			if (cu->cu_topology_change)
606 				bp->bp_rcvdtc = 1;
607 			if (cu->cu_topology_change_ack)
608 				bp->bp_rcvdtca = 1;
609 
610 			if (bp->bp_agree &&
611 			    !bstp_pdu_bettersame(bp, BSTP_INFO_RECEIVED))
612 				bp->bp_agree = 0;
613 
614 			/* copy the received priority and timers to the port */
615 			bp->bp_port_pv = cu->cu_pv;
616 			bp->bp_port_msg_age = cu->cu_message_age;
617 			bp->bp_port_max_age = cu->cu_max_age;
618 			bp->bp_port_fdelay = cu->cu_forward_delay;
619 			bp->bp_port_htime =
620 				(cu->cu_hello_time > BSTP_MIN_HELLO_TIME ?
621 				 cu->cu_hello_time : BSTP_MIN_HELLO_TIME);
622 
623 			/* set expiry for the new info */
624 			bstp_set_timer_msgage(bp);
625 
626 			bp->bp_infois = BSTP_INFO_RECEIVED;
627 			bstp_assign_roles(bs);
628 			break;
629 
630 		case BSTP_PDU_REPEATED:
631 			if (cu->cu_proposal && cu->cu_forwarding == 0)
632 				bp->bp_proposed = 1;
633 			if (cu->cu_topology_change)
634 				bp->bp_rcvdtc = 1;
635 			if (cu->cu_topology_change_ack)
636 				bp->bp_rcvdtca = 1;
637 
638 			/* rearm the age timer */
639 			bstp_set_timer_msgage(bp);
640 			break;
641 
642 		case BSTP_PDU_INFERIOR:
643 			if (cu->cu_learning) {
644 				bp->bp_agreed = 1;
645 				bp->bp_proposing = 0;
646 			}
647 			break;
648 
649 		case BSTP_PDU_INFERIORALT:
650 			/*
651 			 * only point to point links are allowed fast
652 			 * transitions to forwarding.
653 			 */
654 			if (cu->cu_agree && bp->bp_ptp_link) {
655 				bp->bp_agreed = 1;
656 				bp->bp_proposing = 0;
657 			} else
658 				bp->bp_agreed = 0;
659 
660 			if (cu->cu_topology_change)
661 				bp->bp_rcvdtc = 1;
662 			if (cu->cu_topology_change_ack)
663 				bp->bp_rcvdtca = 1;
664 			break;
665 
666 		case BSTP_PDU_OTHER:
667 			return;	/* do nothing */
668 	}
669 	/* update the state machines with the new data */
670 	bstp_update_state(bs, bp);
671 }
672 
673 static int
674 bstp_pdu_rcvtype(struct bstp_port *bp, struct bstp_config_unit *cu)
675 {
676 	int type;
677 
678 	/* default return type */
679 	type = BSTP_PDU_OTHER;
680 
681 	switch (cu->cu_role) {
682 	case BSTP_ROLE_DESIGNATED:
683 		if (bstp_info_superior(&bp->bp_port_pv, &cu->cu_pv))
684 			/* bpdu priority is superior */
685 			type = BSTP_PDU_SUPERIOR;
686 		else if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) ==
687 		    INFO_SAME) {
688 			if (bp->bp_port_msg_age != cu->cu_message_age ||
689 			    bp->bp_port_max_age != cu->cu_max_age ||
690 			    bp->bp_port_fdelay != cu->cu_forward_delay ||
691 			    bp->bp_port_htime != cu->cu_hello_time)
692 				/* bpdu priority is equal and timers differ */
693 				type = BSTP_PDU_SUPERIOR;
694 			else
695 				/* bpdu is equal */
696 				type = BSTP_PDU_REPEATED;
697 		} else
698 			/* bpdu priority is worse */
699 			type = BSTP_PDU_INFERIOR;
700 
701 		break;
702 
703 	case BSTP_ROLE_ROOT:
704 	case BSTP_ROLE_ALTERNATE:
705 	case BSTP_ROLE_BACKUP:
706 		if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) <= INFO_SAME)
707 			/*
708 			 * not a designated port and priority is the same or
709 			 * worse
710 			 */
711 			type = BSTP_PDU_INFERIORALT;
712 		break;
713 	}
714 
715 	return (type);
716 }
717 
718 static int
719 bstp_pdu_bettersame(struct bstp_port *bp, int newinfo)
720 {
721 	if (newinfo == BSTP_INFO_RECEIVED &&
722 	    bp->bp_infois == BSTP_INFO_RECEIVED &&
723 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_msg_cu.cu_pv) >= INFO_SAME)
724 		return (1);
725 
726 	if (newinfo == BSTP_INFO_MINE &&
727 	    bp->bp_infois == BSTP_INFO_MINE &&
728 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_desg_pv) >= INFO_SAME)
729 		return (1);
730 
731 	return (0);
732 }
733 
734 static int
735 bstp_info_cmp(struct bstp_pri_vector *pv,
736     struct bstp_pri_vector *cpv)
737 {
738 	if (cpv->pv_root_id < pv->pv_root_id)
739 		return (INFO_BETTER);
740 	if (cpv->pv_root_id > pv->pv_root_id)
741 		return (INFO_WORSE);
742 
743 	if (cpv->pv_cost < pv->pv_cost)
744 		return (INFO_BETTER);
745 	if (cpv->pv_cost > pv->pv_cost)
746 		return (INFO_WORSE);
747 
748 	if (cpv->pv_dbridge_id < pv->pv_dbridge_id)
749 		return (INFO_BETTER);
750 	if (cpv->pv_dbridge_id > pv->pv_dbridge_id)
751 		return (INFO_WORSE);
752 
753 	if (cpv->pv_dport_id < pv->pv_dport_id)
754 		return (INFO_BETTER);
755 	if (cpv->pv_dport_id > pv->pv_dport_id)
756 		return (INFO_WORSE);
757 
758 	return (INFO_SAME);
759 }
760 
761 /*
762  * This message priority vector is superior to the port priority vector and
763  * will replace it if, and only if, the message priority vector is better than
764  * the port priority vector, or the message has been transmitted from the same
765  * designated bridge and designated port as the port priority vector.
766  */
767 static int
768 bstp_info_superior(struct bstp_pri_vector *pv,
769     struct bstp_pri_vector *cpv)
770 {
771 	if (bstp_info_cmp(pv, cpv) == INFO_BETTER ||
772 	    (bstp_same_bridgeid(pv->pv_dbridge_id, cpv->pv_dbridge_id) &&
773 	    (cpv->pv_dport_id & 0xfff) == (pv->pv_dport_id & 0xfff)))
774 		return (1);
775 	return (0);
776 }
777 
778 static void
779 bstp_assign_roles(struct bstp_state *bs)
780 {
781 	struct bstp_port *bp, *rbp = NULL;
782 	struct bstp_pri_vector pv;
783 
784 	/* default to our priority vector */
785 	bs->bs_root_pv = bs->bs_bridge_pv;
786 	bs->bs_root_msg_age = 0;
787 	bs->bs_root_max_age = bs->bs_bridge_max_age;
788 	bs->bs_root_fdelay = bs->bs_bridge_fdelay;
789 	bs->bs_root_htime = bs->bs_bridge_htime;
790 	bs->bs_root_port = NULL;
791 
792 	/* check if any received info supersedes us */
793 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
794 		if (bp->bp_infois != BSTP_INFO_RECEIVED)
795 			continue;
796 
797 		pv = bp->bp_port_pv;
798 		pv.pv_cost += bp->bp_path_cost;
799 
800 		/*
801 		 * The root priority vector is the best of the set comprising
802 		 * the bridge priority vector plus all root path priority
803 		 * vectors whose bridge address is not equal to us.
804 		 */
805 		if (bstp_same_bridgeid(pv.pv_dbridge_id,
806 		    bs->bs_bridge_pv.pv_dbridge_id) == 0 &&
807 		    bstp_info_cmp(&bs->bs_root_pv, &pv) == INFO_BETTER) {
808 			/* the port vector replaces the root */
809 			bs->bs_root_pv = pv;
810 			bs->bs_root_msg_age = bp->bp_port_msg_age +
811 			    BSTP_MESSAGE_AGE_INCR;
812 			bs->bs_root_max_age = bp->bp_port_max_age;
813 			bs->bs_root_fdelay = bp->bp_port_fdelay;
814 			bs->bs_root_htime = bp->bp_port_htime;
815 			rbp = bp;
816 		}
817 	}
818 
819 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
820 		/* calculate the port designated vector */
821 		bp->bp_desg_pv.pv_root_id = bs->bs_root_pv.pv_root_id;
822 		bp->bp_desg_pv.pv_cost = bs->bs_root_pv.pv_cost;
823 		bp->bp_desg_pv.pv_dbridge_id = bs->bs_bridge_pv.pv_dbridge_id;
824 		bp->bp_desg_pv.pv_dport_id = bp->bp_port_id;
825 		bp->bp_desg_pv.pv_port_id = bp->bp_port_id;
826 
827 		/* calculate designated times */
828 		bp->bp_desg_msg_age = bs->bs_root_msg_age;
829 		bp->bp_desg_max_age = bs->bs_root_max_age;
830 		bp->bp_desg_fdelay = bs->bs_root_fdelay;
831 		bp->bp_desg_htime = bs->bs_bridge_htime;
832 
833 
834 		switch (bp->bp_infois) {
835 		case BSTP_INFO_DISABLED:
836 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
837 			break;
838 
839 		case BSTP_INFO_AGED:
840 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
841 			bstp_update_info(bp);
842 			break;
843 
844 		case BSTP_INFO_MINE:
845 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
846 			/* update the port info if stale */
847 			if (bstp_info_cmp(&bp->bp_port_pv,
848 			    &bp->bp_desg_pv) != INFO_SAME ||
849 			    (rbp != NULL &&
850 			    (bp->bp_port_msg_age != rbp->bp_port_msg_age ||
851 			    bp->bp_port_max_age != rbp->bp_port_max_age ||
852 			    bp->bp_port_fdelay != rbp->bp_port_fdelay ||
853 			    bp->bp_port_htime != rbp->bp_port_htime)))
854 				bstp_update_info(bp);
855 			break;
856 
857 		case BSTP_INFO_RECEIVED:
858 			if (bp == rbp) {
859 				/*
860 				 * root priority is derived from this
861 				 * port, make it the root port.
862 				 */
863 				bstp_set_port_role(bp, BSTP_ROLE_ROOT);
864 				bs->bs_root_port = bp;
865 			} else if (bstp_info_cmp(&bp->bp_port_pv,
866 				    &bp->bp_desg_pv) == INFO_BETTER) {
867 				/*
868 				 * the port priority is lower than the root
869 				 * port.
870 				 */
871 				bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
872 				bstp_update_info(bp);
873 			} else {
874 				if (bstp_same_bridgeid(
875 				    bp->bp_port_pv.pv_dbridge_id,
876 				    bs->bs_bridge_pv.pv_dbridge_id)) {
877 					/*
878 					 * the designated bridge refers to
879 					 * another port on this bridge.
880 					 */
881 					bstp_set_port_role(bp,
882 					    BSTP_ROLE_BACKUP);
883 				} else {
884 					/*
885 					 * the port is an inferior path to the
886 					 * root bridge.
887 					 */
888 					bstp_set_port_role(bp,
889 					    BSTP_ROLE_ALTERNATE);
890 				}
891 			}
892 			break;
893 		}
894 	}
895 }
896 
897 static void
898 bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
899 {
900 	struct bstp_port *bp2;
901 	int synced;
902 
903 	BSTP_LOCK_ASSERT(bs);
904 
905 	/* check if all the ports have syncronised again */
906 	if (!bs->bs_allsynced) {
907 		synced = 1;
908 		LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
909 			if (!(bp2->bp_synced ||
910 			     bp2->bp_role == BSTP_ROLE_ROOT)) {
911 				synced = 0;
912 				break;
913 			}
914 		}
915 		bs->bs_allsynced = synced;
916 	}
917 
918 	bstp_update_roles(bs, bp);
919 	bstp_update_tc(bp);
920 }
921 
922 static void
923 bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
924 {
925 	switch (bp->bp_role) {
926 	case BSTP_ROLE_DISABLED:
927 		/* Clear any flags if set */
928 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
929 			bp->bp_sync = 0;
930 			bp->bp_synced = 1;
931 			bp->bp_reroot = 0;
932 		}
933 		break;
934 
935 	case BSTP_ROLE_ALTERNATE:
936 	case BSTP_ROLE_BACKUP:
937 		if ((bs->bs_allsynced && !bp->bp_agree) ||
938 		    (bp->bp_proposed && bp->bp_agree)) {
939 			bp->bp_proposed = 0;
940 			bp->bp_agree = 1;
941 			bp->bp_flags |= BSTP_PORT_NEWINFO;
942 			DPRINTF("%s -> ALTERNATE_AGREED\n",
943 			    bp->bp_ifp->if_xname);
944 		}
945 
946 		if (bp->bp_proposed && !bp->bp_agree) {
947 			bstp_set_all_sync(bs);
948 			bp->bp_proposed = 0;
949 			DPRINTF("%s -> ALTERNATE_PROPOSED\n",
950 			    bp->bp_ifp->if_xname);
951 		}
952 
953 		/* Clear any flags if set */
954 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
955 			bp->bp_sync = 0;
956 			bp->bp_synced = 1;
957 			bp->bp_reroot = 0;
958 			DPRINTF("%s -> ALTERNATE_PORT\n", bp->bp_ifp->if_xname);
959 		}
960 		break;
961 
962 	case BSTP_ROLE_ROOT:
963 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING && !bp->bp_reroot) {
964 			bstp_set_all_reroot(bs);
965 			DPRINTF("%s -> ROOT_REROOT\n", bp->bp_ifp->if_xname);
966 		}
967 
968 		if ((bs->bs_allsynced && !bp->bp_agree) ||
969 		    (bp->bp_proposed && bp->bp_agree)) {
970 			bp->bp_proposed = 0;
971 			bp->bp_sync = 0;
972 			bp->bp_agree = 1;
973 			bp->bp_flags |= BSTP_PORT_NEWINFO;
974 			DPRINTF("%s -> ROOT_AGREED\n", bp->bp_ifp->if_xname);
975 		}
976 
977 		if (bp->bp_proposed && !bp->bp_agree) {
978 			bstp_set_all_sync(bs);
979 			bp->bp_proposed = 0;
980 			DPRINTF("%s -> ROOT_PROPOSED\n", bp->bp_ifp->if_xname);
981 		}
982 
983 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
984 		    (bp->bp_forward_delay_timer.active == 0 ||
985 		    (bstp_rerooted(bs, bp) &&
986 		    bp->bp_recent_backup_timer.active == 0 &&
987 		    bp->bp_protover == BSTP_PROTO_RSTP))) {
988 			switch (bp->bp_state) {
989 			case BSTP_IFSTATE_DISCARDING:
990 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
991 				break;
992 			case BSTP_IFSTATE_LEARNING:
993 				bstp_set_port_state(bp,
994 				    BSTP_IFSTATE_FORWARDING);
995 				break;
996 			}
997 		}
998 
999 		if (bp->bp_state == BSTP_IFSTATE_FORWARDING && bp->bp_reroot) {
1000 			bp->bp_reroot = 0;
1001 			DPRINTF("%s -> ROOT_REROOTED\n", bp->bp_ifp->if_xname);
1002 		}
1003 		break;
1004 
1005 	case BSTP_ROLE_DESIGNATED:
1006 		if (bp->bp_recent_root_timer.active == 0 && bp->bp_reroot) {
1007 			bp->bp_reroot = 0;
1008 			DPRINTF("%s -> DESIGNATED_RETIRED\n",
1009 			    bp->bp_ifp->if_xname);
1010 		}
1011 
1012 		if ((bp->bp_state == BSTP_IFSTATE_DISCARDING &&
1013 		    !bp->bp_synced) || (bp->bp_agreed && !bp->bp_synced) ||
1014 		    (bp->bp_operedge && !bp->bp_synced) ||
1015 		    (bp->bp_sync && bp->bp_synced)) {
1016 			bstp_timer_stop(&bp->bp_recent_root_timer);
1017 			bp->bp_synced = 1;
1018 			bp->bp_sync = 0;
1019 			DPRINTF("%s -> DESIGNATED_SYNCED\n",
1020 			    bp->bp_ifp->if_xname);
1021 		}
1022 
1023 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1024 		    !bp->bp_agreed && !bp->bp_proposing &&
1025 		    !bp->bp_operedge) {
1026 			bp->bp_proposing = 1;
1027 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1028 			bstp_timer_start(&bp->bp_edge_delay_timer,
1029 			    (bp->bp_ptp_link ? BSTP_DEFAULT_MIGRATE_DELAY :
1030 			     bp->bp_desg_max_age));
1031 			DPRINTF("%s -> DESIGNATED_PROPOSE\n",
1032 			    bp->bp_ifp->if_xname);
1033 		}
1034 
1035 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1036 		    (bp->bp_forward_delay_timer.active == 0 || bp->bp_agreed ||
1037 		    bp->bp_operedge) &&
1038 		    (bp->bp_recent_root_timer.active == 0 || !bp->bp_reroot) &&
1039 		    !bp->bp_sync) {
1040 			if (bp->bp_agreed)
1041 				DPRINTF("%s -> AGREED\n", bp->bp_ifp->if_xname);
1042 			/*
1043 			 * If agreed|operedge then go straight to forwarding,
1044 			 * otherwise follow discard -> learn -> forward.
1045 			 */
1046 			if (bp->bp_agreed || bp->bp_operedge ||
1047 			    bp->bp_state == BSTP_IFSTATE_LEARNING) {
1048 				bstp_set_port_state(bp,
1049 				    BSTP_IFSTATE_FORWARDING);
1050 				bp->bp_agreed = bp->bp_protover;
1051 			} else if (bp->bp_state == BSTP_IFSTATE_DISCARDING)
1052 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
1053 		}
1054 
1055 		if (((bp->bp_sync && !bp->bp_synced) ||
1056 		    (bp->bp_reroot && bp->bp_recent_root_timer.active) ||
1057 		    (bp->bp_flags & BSTP_PORT_DISPUTED)) && !bp->bp_operedge &&
1058 		    bp->bp_state != BSTP_IFSTATE_DISCARDING) {
1059 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1060 			bp->bp_flags &= ~BSTP_PORT_DISPUTED;
1061 			bstp_timer_start(&bp->bp_forward_delay_timer,
1062 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1063 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1064 			DPRINTF("%s -> DESIGNATED_DISCARD\n",
1065 			    bp->bp_ifp->if_xname);
1066 		}
1067 		break;
1068 	}
1069 
1070 	if (bp->bp_flags & BSTP_PORT_NEWINFO)
1071 		bstp_transmit(bs, bp);
1072 }
1073 
1074 static void
1075 bstp_update_tc(struct bstp_port *bp)
1076 {
1077 	switch (bp->bp_tcstate) {
1078 		case BSTP_TCSTATE_ACTIVE:
1079 			if ((bp->bp_role != BSTP_ROLE_DESIGNATED &&
1080 			    bp->bp_role != BSTP_ROLE_ROOT) || bp->bp_operedge)
1081 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1082 
1083 			if (bp->bp_rcvdtcn)
1084 				bstp_set_port_tc(bp, BSTP_TCSTATE_TCN);
1085 			if (bp->bp_rcvdtc)
1086 				bstp_set_port_tc(bp, BSTP_TCSTATE_TC);
1087 
1088 			if (bp->bp_tc_prop && !bp->bp_operedge)
1089 				bstp_set_port_tc(bp, BSTP_TCSTATE_PROPAG);
1090 
1091 			if (bp->bp_rcvdtca)
1092 				bstp_set_port_tc(bp, BSTP_TCSTATE_ACK);
1093 			break;
1094 
1095 		case BSTP_TCSTATE_INACTIVE:
1096 			if ((bp->bp_state == BSTP_IFSTATE_LEARNING ||
1097 			    bp->bp_state == BSTP_IFSTATE_FORWARDING) &&
1098 			    bp->bp_fdbflush == 0)
1099 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1100 			break;
1101 
1102 		case BSTP_TCSTATE_LEARNING:
1103 			if (bp->bp_rcvdtc || bp->bp_rcvdtcn || bp->bp_rcvdtca ||
1104 			    bp->bp_tc_prop)
1105 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1106 			else if (bp->bp_role != BSTP_ROLE_DESIGNATED &&
1107 				 bp->bp_role != BSTP_ROLE_ROOT &&
1108 				 bp->bp_state == BSTP_IFSTATE_DISCARDING)
1109 				bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1110 
1111 			if ((bp->bp_role == BSTP_ROLE_DESIGNATED ||
1112 			    bp->bp_role == BSTP_ROLE_ROOT) &&
1113 			    bp->bp_state == BSTP_IFSTATE_FORWARDING &&
1114 			    !bp->bp_operedge)
1115 				bstp_set_port_tc(bp, BSTP_TCSTATE_DETECTED);
1116 			break;
1117 
1118 		/* these are transient states and go straight back to ACTIVE */
1119 		case BSTP_TCSTATE_DETECTED:
1120 		case BSTP_TCSTATE_TCN:
1121 		case BSTP_TCSTATE_TC:
1122 		case BSTP_TCSTATE_PROPAG:
1123 		case BSTP_TCSTATE_ACK:
1124 			DPRINTF("Invalid TC state for %s\n",
1125 			    bp->bp_ifp->if_xname);
1126 			break;
1127 	}
1128 
1129 }
1130 
1131 static void
1132 bstp_update_info(struct bstp_port *bp)
1133 {
1134 	struct bstp_state *bs = bp->bp_bs;
1135 
1136 	bp->bp_proposing = 0;
1137 	bp->bp_proposed = 0;
1138 
1139 	if (bp->bp_agreed && !bstp_pdu_bettersame(bp, BSTP_INFO_MINE))
1140 		bp->bp_agreed = 0;
1141 
1142 	if (bp->bp_synced && !bp->bp_agreed) {
1143 		bp->bp_synced = 0;
1144 		bs->bs_allsynced = 0;
1145 	}
1146 
1147 	/* copy the designated pv to the port */
1148 	bp->bp_port_pv = bp->bp_desg_pv;
1149 	bp->bp_port_msg_age = bp->bp_desg_msg_age;
1150 	bp->bp_port_max_age = bp->bp_desg_max_age;
1151 	bp->bp_port_fdelay = bp->bp_desg_fdelay;
1152 	bp->bp_port_htime = bp->bp_desg_htime;
1153 	bp->bp_infois = BSTP_INFO_MINE;
1154 
1155 	/* Set transmit flag but do not immediately send */
1156 	bp->bp_flags |= BSTP_PORT_NEWINFO;
1157 }
1158 
1159 /* set tcprop on every port other than the caller */
1160 static void
1161 bstp_set_other_tcprop(struct bstp_port *bp)
1162 {
1163 	struct bstp_state *bs = bp->bp_bs;
1164 	struct bstp_port *bp2;
1165 
1166 	BSTP_LOCK_ASSERT(bs);
1167 
1168 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1169 		if (bp2 == bp)
1170 			continue;
1171 		bp2->bp_tc_prop = 1;
1172 	}
1173 }
1174 
1175 static void
1176 bstp_set_all_reroot(struct bstp_state *bs)
1177 {
1178 	struct bstp_port *bp;
1179 
1180 	BSTP_LOCK_ASSERT(bs);
1181 
1182 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1183 		bp->bp_reroot = 1;
1184 }
1185 
1186 static void
1187 bstp_set_all_sync(struct bstp_state *bs)
1188 {
1189 	struct bstp_port *bp;
1190 
1191 	BSTP_LOCK_ASSERT(bs);
1192 
1193 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1194 		bp->bp_sync = 1;
1195 		bp->bp_synced = 0;	/* Not explicit in spec */
1196 	}
1197 
1198 	bs->bs_allsynced = 0;
1199 }
1200 
1201 static void
1202 bstp_set_port_state(struct bstp_port *bp, int state)
1203 {
1204 	if (bp->bp_state == state)
1205 		return;
1206 
1207 	bp->bp_state = state;
1208 
1209 	switch (bp->bp_state) {
1210 		case BSTP_IFSTATE_DISCARDING:
1211 			DPRINTF("state changed to DISCARDING on %s\n",
1212 			    bp->bp_ifp->if_xname);
1213 			break;
1214 
1215 		case BSTP_IFSTATE_LEARNING:
1216 			DPRINTF("state changed to LEARNING on %s\n",
1217 			    bp->bp_ifp->if_xname);
1218 
1219 			bstp_timer_start(&bp->bp_forward_delay_timer,
1220 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1221 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1222 			break;
1223 
1224 		case BSTP_IFSTATE_FORWARDING:
1225 			DPRINTF("state changed to FORWARDING on %s\n",
1226 			    bp->bp_ifp->if_xname);
1227 
1228 			bstp_timer_stop(&bp->bp_forward_delay_timer);
1229 			/* Record that we enabled forwarding */
1230 			bp->bp_forward_transitions++;
1231 			break;
1232 	}
1233 
1234 	/* notify the parent bridge */
1235 	taskqueue_enqueue(taskqueue_swi, &bp->bp_statetask);
1236 }
1237 
1238 static void
1239 bstp_set_port_role(struct bstp_port *bp, int role)
1240 {
1241 	struct bstp_state *bs = bp->bp_bs;
1242 
1243 	if (bp->bp_role == role)
1244 		return;
1245 
1246 	/* perform pre-change tasks */
1247 	switch (bp->bp_role) {
1248 		case BSTP_ROLE_DISABLED:
1249 			bstp_timer_start(&bp->bp_forward_delay_timer,
1250 			    bp->bp_desg_max_age);
1251 			break;
1252 
1253 		case BSTP_ROLE_BACKUP:
1254 			bstp_timer_start(&bp->bp_recent_backup_timer,
1255 			    bp->bp_desg_htime * 2);
1256 			/* fall through */
1257 		case BSTP_ROLE_ALTERNATE:
1258 			bstp_timer_start(&bp->bp_forward_delay_timer,
1259 			    bp->bp_desg_fdelay);
1260 			bp->bp_sync = 0;
1261 			bp->bp_synced = 1;
1262 			bp->bp_reroot = 0;
1263 			break;
1264 
1265 		case BSTP_ROLE_ROOT:
1266 			bstp_timer_start(&bp->bp_recent_root_timer,
1267 			    BSTP_DEFAULT_FORWARD_DELAY);
1268 			break;
1269 	}
1270 
1271 	bp->bp_role = role;
1272 	/* clear values not carried between roles */
1273 	bp->bp_proposing = 0;
1274 	bs->bs_allsynced = 0;
1275 
1276 	/* initialise the new role */
1277 	switch (bp->bp_role) {
1278 		case BSTP_ROLE_DISABLED:
1279 		case BSTP_ROLE_ALTERNATE:
1280 		case BSTP_ROLE_BACKUP:
1281 			DPRINTF("%s role -> ALT/BACK/DISABLED\n",
1282 			    bp->bp_ifp->if_xname);
1283 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1284 			bstp_timer_stop(&bp->bp_recent_root_timer);
1285 			bstp_timer_latch(&bp->bp_forward_delay_timer);
1286 			bp->bp_sync = 0;
1287 			bp->bp_synced = 1;
1288 			bp->bp_reroot = 0;
1289 			break;
1290 
1291 		case BSTP_ROLE_ROOT:
1292 			DPRINTF("%s role -> ROOT\n",
1293 			    bp->bp_ifp->if_xname);
1294 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1295 			bstp_timer_latch(&bp->bp_recent_root_timer);
1296 			bp->bp_proposing = 0;
1297 			break;
1298 
1299 		case BSTP_ROLE_DESIGNATED:
1300 			DPRINTF("%s role -> DESIGNATED\n",
1301 			    bp->bp_ifp->if_xname);
1302 			bstp_timer_start(&bp->bp_hello_timer,
1303 			    bp->bp_desg_htime);
1304 			bp->bp_agree = 0;
1305 			break;
1306 	}
1307 
1308 	/* let the TC state know that the role changed */
1309 	bstp_update_tc(bp);
1310 }
1311 
1312 static void
1313 bstp_set_port_proto(struct bstp_port *bp, int proto)
1314 {
1315 	struct bstp_state *bs = bp->bp_bs;
1316 
1317 	/* supported protocol versions */
1318 	switch (proto) {
1319 		case BSTP_PROTO_STP:
1320 			/* we can downgrade protocols only */
1321 			bstp_timer_stop(&bp->bp_migrate_delay_timer);
1322 			/* clear unsupported features */
1323 			bp->bp_operedge = 0;
1324 			/* STP compat mode only uses 16 bits of the 32 */
1325 			if (bp->bp_path_cost > 65535)
1326 				bp->bp_path_cost = 65535;
1327 			break;
1328 
1329 		case BSTP_PROTO_RSTP:
1330 			bstp_timer_start(&bp->bp_migrate_delay_timer,
1331 			    bs->bs_migration_delay);
1332 			break;
1333 
1334 		default:
1335 			DPRINTF("Unsupported STP version %d\n", proto);
1336 			return;
1337 	}
1338 
1339 	bp->bp_protover = proto;
1340 	bp->bp_flags &= ~BSTP_PORT_CANMIGRATE;
1341 }
1342 
1343 static void
1344 bstp_set_port_tc(struct bstp_port *bp, int state)
1345 {
1346 	struct bstp_state *bs = bp->bp_bs;
1347 
1348 	bp->bp_tcstate = state;
1349 
1350 	/* initialise the new state */
1351 	switch (bp->bp_tcstate) {
1352 		case BSTP_TCSTATE_ACTIVE:
1353 			DPRINTF("%s -> TC_ACTIVE\n", bp->bp_ifp->if_xname);
1354 			/* nothing to do */
1355 			break;
1356 
1357 		case BSTP_TCSTATE_INACTIVE:
1358 			bstp_timer_stop(&bp->bp_tc_timer);
1359 			/* flush routes on the parent bridge */
1360 			bp->bp_fdbflush = 1;
1361 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1362 			bp->bp_tc_ack = 0;
1363 			DPRINTF("%s -> TC_INACTIVE\n", bp->bp_ifp->if_xname);
1364 			break;
1365 
1366 		case BSTP_TCSTATE_LEARNING:
1367 			bp->bp_rcvdtc = 0;
1368 			bp->bp_rcvdtcn = 0;
1369 			bp->bp_rcvdtca = 0;
1370 			bp->bp_tc_prop = 0;
1371 			DPRINTF("%s -> TC_LEARNING\n", bp->bp_ifp->if_xname);
1372 			break;
1373 
1374 		case BSTP_TCSTATE_DETECTED:
1375 			bstp_set_timer_tc(bp);
1376 			bstp_set_other_tcprop(bp);
1377 			/* send out notification */
1378 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1379 			bstp_transmit(bs, bp);
1380 			getmicrotime(&bs->bs_last_tc_time);
1381 			DPRINTF("%s -> TC_DETECTED\n", bp->bp_ifp->if_xname);
1382 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1383 			break;
1384 
1385 		case BSTP_TCSTATE_TCN:
1386 			bstp_set_timer_tc(bp);
1387 			DPRINTF("%s -> TC_TCN\n", bp->bp_ifp->if_xname);
1388 			/* fall through */
1389 		case BSTP_TCSTATE_TC:
1390 			bp->bp_rcvdtc = 0;
1391 			bp->bp_rcvdtcn = 0;
1392 			if (bp->bp_role == BSTP_ROLE_DESIGNATED)
1393 				bp->bp_tc_ack = 1;
1394 
1395 			bstp_set_other_tcprop(bp);
1396 			DPRINTF("%s -> TC_TC\n", bp->bp_ifp->if_xname);
1397 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1398 			break;
1399 
1400 		case BSTP_TCSTATE_PROPAG:
1401 			/* flush routes on the parent bridge */
1402 			bp->bp_fdbflush = 1;
1403 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1404 			bp->bp_tc_prop = 0;
1405 			bstp_set_timer_tc(bp);
1406 			DPRINTF("%s -> TC_PROPAG\n", bp->bp_ifp->if_xname);
1407 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1408 			break;
1409 
1410 		case BSTP_TCSTATE_ACK:
1411 			bstp_timer_stop(&bp->bp_tc_timer);
1412 			bp->bp_rcvdtca = 0;
1413 			DPRINTF("%s -> TC_ACK\n", bp->bp_ifp->if_xname);
1414 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1415 			break;
1416 	}
1417 }
1418 
1419 static void
1420 bstp_set_timer_tc(struct bstp_port *bp)
1421 {
1422 	struct bstp_state *bs = bp->bp_bs;
1423 
1424 	if (bp->bp_tc_timer.active)
1425 		return;
1426 
1427 	switch (bp->bp_protover) {
1428 		case BSTP_PROTO_RSTP:
1429 			bstp_timer_start(&bp->bp_tc_timer,
1430 			    bp->bp_desg_htime + BSTP_TICK_VAL);
1431 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1432 			break;
1433 
1434 		case BSTP_PROTO_STP:
1435 			bstp_timer_start(&bp->bp_tc_timer,
1436 			    bs->bs_root_max_age + bs->bs_root_fdelay);
1437 			break;
1438 	}
1439 }
1440 
1441 static void
1442 bstp_set_timer_msgage(struct bstp_port *bp)
1443 {
1444 	if (bp->bp_port_msg_age + BSTP_MESSAGE_AGE_INCR <=
1445 	    bp->bp_port_max_age) {
1446 		bstp_timer_start(&bp->bp_message_age_timer,
1447 		    bp->bp_port_htime * 3);
1448 	} else
1449 		/* expires immediately */
1450 		bstp_timer_start(&bp->bp_message_age_timer, 0);
1451 }
1452 
1453 static int
1454 bstp_rerooted(struct bstp_state *bs, struct bstp_port *bp)
1455 {
1456 	struct bstp_port *bp2;
1457 	int rr_set = 0;
1458 
1459 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1460 		if (bp2 == bp)
1461 			continue;
1462 		if (bp2->bp_recent_root_timer.active) {
1463 			rr_set = 1;
1464 			break;
1465 		}
1466 	}
1467 	return (!rr_set);
1468 }
1469 
1470 int
1471 bstp_set_htime(struct bstp_state *bs, int t)
1472 {
1473 	/* convert seconds to ticks */
1474 	t *=  BSTP_TICK_VAL;
1475 
1476 	/* value can only be changed in leagacy stp mode */
1477 	if (bs->bs_protover != BSTP_PROTO_STP)
1478 		return (EPERM);
1479 
1480 	if (t < BSTP_MIN_HELLO_TIME || t > BSTP_MAX_HELLO_TIME)
1481 		return (EINVAL);
1482 
1483 	BSTP_LOCK(bs);
1484 	bs->bs_bridge_htime = t;
1485 	bstp_reinit(bs);
1486 	BSTP_UNLOCK(bs);
1487 	return (0);
1488 }
1489 
1490 int
1491 bstp_set_fdelay(struct bstp_state *bs, int t)
1492 {
1493 	/* convert seconds to ticks */
1494 	t *= BSTP_TICK_VAL;
1495 
1496 	if (t < BSTP_MIN_FORWARD_DELAY || t > BSTP_MAX_FORWARD_DELAY)
1497 		return (EINVAL);
1498 
1499 	BSTP_LOCK(bs);
1500 	bs->bs_bridge_fdelay = t;
1501 	bstp_reinit(bs);
1502 	BSTP_UNLOCK(bs);
1503 	return (0);
1504 }
1505 
1506 int
1507 bstp_set_maxage(struct bstp_state *bs, int t)
1508 {
1509 	/* convert seconds to ticks */
1510 	t *= BSTP_TICK_VAL;
1511 
1512 	if (t < BSTP_MIN_MAX_AGE || t > BSTP_MAX_MAX_AGE)
1513 		return (EINVAL);
1514 
1515 	BSTP_LOCK(bs);
1516 	bs->bs_bridge_max_age = t;
1517 	bstp_reinit(bs);
1518 	BSTP_UNLOCK(bs);
1519 	return (0);
1520 }
1521 
1522 int
1523 bstp_set_holdcount(struct bstp_state *bs, int count)
1524 {
1525 	struct bstp_port *bp;
1526 
1527 	if (count < BSTP_MIN_HOLD_COUNT ||
1528 	    count > BSTP_MAX_HOLD_COUNT)
1529 		return (EINVAL);
1530 
1531 	BSTP_LOCK(bs);
1532 	bs->bs_txholdcount = count;
1533 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1534 		bp->bp_txcount = 0;
1535 	BSTP_UNLOCK(bs);
1536 	return (0);
1537 }
1538 
1539 int
1540 bstp_set_protocol(struct bstp_state *bs, int proto)
1541 {
1542 	struct bstp_port *bp;
1543 
1544 	switch (proto) {
1545 		/* Supported protocol versions */
1546 		case BSTP_PROTO_STP:
1547 		case BSTP_PROTO_RSTP:
1548 			break;
1549 
1550 		default:
1551 			return (EINVAL);
1552 	}
1553 
1554 	BSTP_LOCK(bs);
1555 	bs->bs_protover = proto;
1556 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
1557 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1558 		/* reinit state */
1559 		bp->bp_infois = BSTP_INFO_DISABLED;
1560 		bp->bp_txcount = 0;
1561 		bstp_set_port_proto(bp, bs->bs_protover);
1562 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
1563 		bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1564 		bstp_timer_stop(&bp->bp_recent_backup_timer);
1565 	}
1566 	bstp_reinit(bs);
1567 	BSTP_UNLOCK(bs);
1568 	return (0);
1569 }
1570 
1571 int
1572 bstp_set_priority(struct bstp_state *bs, int pri)
1573 {
1574 	if (pri < 0 || pri > BSTP_MAX_PRIORITY)
1575 		return (EINVAL);
1576 
1577 	/* Limit to steps of 4096 */
1578 	pri -= pri % 4096;
1579 
1580 	BSTP_LOCK(bs);
1581 	bs->bs_bridge_priority = pri;
1582 	bstp_reinit(bs);
1583 	BSTP_UNLOCK(bs);
1584 	return (0);
1585 }
1586 
1587 int
1588 bstp_set_port_priority(struct bstp_port *bp, int pri)
1589 {
1590 	struct bstp_state *bs = bp->bp_bs;
1591 
1592 	if (pri < 0 || pri > BSTP_MAX_PORT_PRIORITY)
1593 		return (EINVAL);
1594 
1595 	/* Limit to steps of 16 */
1596 	pri -= pri % 16;
1597 
1598 	BSTP_LOCK(bs);
1599 	bp->bp_priority = pri;
1600 	bstp_reinit(bs);
1601 	BSTP_UNLOCK(bs);
1602 	return (0);
1603 }
1604 
1605 int
1606 bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
1607 {
1608 	struct bstp_state *bs = bp->bp_bs;
1609 
1610 	if (path_cost > BSTP_MAX_PATH_COST)
1611 		return (EINVAL);
1612 
1613 	/* STP compat mode only uses 16 bits of the 32 */
1614 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1615 		path_cost = 65535;
1616 
1617 	BSTP_LOCK(bs);
1618 
1619 	if (path_cost == 0) {	/* use auto */
1620 		bp->bp_flags &= ~BSTP_PORT_ADMCOST;
1621 		bp->bp_path_cost = bstp_calc_path_cost(bp);
1622 	} else {
1623 		bp->bp_path_cost = path_cost;
1624 		bp->bp_flags |= BSTP_PORT_ADMCOST;
1625 	}
1626 	bstp_reinit(bs);
1627 	BSTP_UNLOCK(bs);
1628 	return (0);
1629 }
1630 
1631 int
1632 bstp_set_edge(struct bstp_port *bp, int set)
1633 {
1634 	struct bstp_state *bs = bp->bp_bs;
1635 
1636 	BSTP_LOCK(bs);
1637 	if ((bp->bp_operedge = set) == 0)
1638 		bp->bp_flags &= ~BSTP_PORT_ADMEDGE;
1639 	else
1640 		bp->bp_flags |= BSTP_PORT_ADMEDGE;
1641 	BSTP_UNLOCK(bs);
1642 	return (0);
1643 }
1644 
1645 int
1646 bstp_set_autoedge(struct bstp_port *bp, int set)
1647 {
1648 	struct bstp_state *bs = bp->bp_bs;
1649 
1650 	BSTP_LOCK(bs);
1651 	if (set) {
1652 		bp->bp_flags |= BSTP_PORT_AUTOEDGE;
1653 		/* we may be able to transition straight to edge */
1654 		if (bp->bp_edge_delay_timer.active == 0)
1655 			bstp_edge_delay_expiry(bs, bp);
1656 	} else
1657 		bp->bp_flags &= ~BSTP_PORT_AUTOEDGE;
1658 	BSTP_UNLOCK(bs);
1659 	return (0);
1660 }
1661 
1662 int
1663 bstp_set_ptp(struct bstp_port *bp, int set)
1664 {
1665 	struct bstp_state *bs = bp->bp_bs;
1666 
1667 	BSTP_LOCK(bs);
1668 	bp->bp_ptp_link = set;
1669 	BSTP_UNLOCK(bs);
1670 	return (0);
1671 }
1672 
1673 int
1674 bstp_set_autoptp(struct bstp_port *bp, int set)
1675 {
1676 	struct bstp_state *bs = bp->bp_bs;
1677 
1678 	BSTP_LOCK(bs);
1679 	if (set) {
1680 		bp->bp_flags |= BSTP_PORT_AUTOPTP;
1681 		if (bp->bp_role != BSTP_ROLE_DISABLED)
1682 			taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
1683 	} else
1684 		bp->bp_flags &= ~BSTP_PORT_AUTOPTP;
1685 	BSTP_UNLOCK(bs);
1686 	return (0);
1687 }
1688 
1689 /*
1690  * Calculate the path cost according to the link speed.
1691  */
1692 static uint32_t
1693 bstp_calc_path_cost(struct bstp_port *bp)
1694 {
1695 	struct ifnet *ifp = bp->bp_ifp;
1696 	uint32_t path_cost;
1697 
1698 	/* If the priority has been manually set then retain the value */
1699 	if (bp->bp_flags & BSTP_PORT_ADMCOST)
1700 		return bp->bp_path_cost;
1701 
1702 	if (ifp->if_link_state == LINK_STATE_DOWN) {
1703 		/* Recalc when the link comes up again */
1704 		bp->bp_flags |= BSTP_PORT_PNDCOST;
1705 		return (BSTP_DEFAULT_PATH_COST);
1706 	}
1707 
1708 	if (ifp->if_baudrate < 1000)
1709 		return (BSTP_DEFAULT_PATH_COST);
1710 
1711  	/* formula from section 17.14, IEEE Std 802.1D-2004 */
1712 	path_cost = 20000000000ULL / (ifp->if_baudrate / 1000);
1713 
1714 	if (path_cost > BSTP_MAX_PATH_COST)
1715 		path_cost = BSTP_MAX_PATH_COST;
1716 
1717 	/* STP compat mode only uses 16 bits of the 32 */
1718 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1719 		path_cost = 65535;
1720 
1721 	return (path_cost);
1722 }
1723 
1724 /*
1725  * Notify the bridge that a port state has changed, we need to do this from a
1726  * taskqueue to avoid a LOR.
1727  */
1728 static void
1729 bstp_notify_state(void *arg, int pending)
1730 {
1731 	struct bstp_port *bp = (struct bstp_port *)arg;
1732 	struct bstp_state *bs = bp->bp_bs;
1733 
1734 	if (bp->bp_active == 1 && bs->bs_state_cb != NULL)
1735 		(*bs->bs_state_cb)(bp->bp_ifp, bp->bp_state);
1736 }
1737 
1738 /*
1739  * Flush the routes on the bridge port, we need to do this from a
1740  * taskqueue to avoid a LOR.
1741  */
1742 static void
1743 bstp_notify_rtage(void *arg, int pending)
1744 {
1745 	struct bstp_port *bp = (struct bstp_port *)arg;
1746 	struct bstp_state *bs = bp->bp_bs;
1747 	int age = 0;
1748 
1749 	BSTP_LOCK(bs);
1750 	switch (bp->bp_protover) {
1751 		case BSTP_PROTO_STP:
1752 			/* convert to seconds */
1753 			age = bp->bp_desg_fdelay / BSTP_TICK_VAL;
1754 			break;
1755 
1756 		case BSTP_PROTO_RSTP:
1757 			age = 0;
1758 			break;
1759 	}
1760 	BSTP_UNLOCK(bs);
1761 
1762 	if (bp->bp_active == 1 && bs->bs_rtage_cb != NULL)
1763 		(*bs->bs_rtage_cb)(bp->bp_ifp, age);
1764 
1765 	/* flush is complete */
1766 	BSTP_LOCK(bs);
1767 	bp->bp_fdbflush = 0;
1768 	BSTP_UNLOCK(bs);
1769 }
1770 
1771 void
1772 bstp_linkstate(struct bstp_port *bp)
1773 {
1774 	struct bstp_state *bs = bp->bp_bs;
1775 
1776 	if (!bp->bp_active)
1777 		return;
1778 
1779 	bstp_ifupdstatus(bp, 0);
1780 	BSTP_LOCK(bs);
1781 	bstp_update_state(bs, bp);
1782 	BSTP_UNLOCK(bs);
1783 }
1784 
1785 static void
1786 bstp_ifupdstatus(void *arg, int pending)
1787 {
1788 	struct bstp_port *bp = (struct bstp_port *)arg;
1789 	struct bstp_state *bs = bp->bp_bs;
1790 	struct ifnet *ifp = bp->bp_ifp;
1791 	struct ifmediareq ifmr;
1792 	int error, changed;
1793 
1794 	if (!bp->bp_active)
1795 		return;
1796 
1797 	bzero((char *)&ifmr, sizeof(ifmr));
1798 	error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);
1799 
1800 	BSTP_LOCK(bs);
1801 	changed = 0;
1802 	if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1803 		if (ifmr.ifm_status & IFM_ACTIVE) {
1804 			/* A full-duplex link is assumed to be point to point */
1805 			if (bp->bp_flags & BSTP_PORT_AUTOPTP) {
1806 				int fdx;
1807 
1808 				fdx = ifmr.ifm_active & IFM_FDX ? 1 : 0;
1809 				if (bp->bp_ptp_link ^ fdx) {
1810 					bp->bp_ptp_link = fdx;
1811 					changed = 1;
1812 				}
1813 			}
1814 
1815 			/* Calc the cost if the link was down previously */
1816 			if (bp->bp_flags & BSTP_PORT_PNDCOST) {
1817 				uint32_t cost;
1818 
1819 				cost = bstp_calc_path_cost(bp);
1820 				if (bp->bp_path_cost != cost) {
1821 					bp->bp_path_cost = cost;
1822 					changed = 1;
1823 				}
1824 				bp->bp_flags &= ~BSTP_PORT_PNDCOST;
1825 			}
1826 
1827 			if (bp->bp_role == BSTP_ROLE_DISABLED) {
1828 				bstp_enable_port(bs, bp);
1829 				changed = 1;
1830 			}
1831 		} else {
1832 			if (bp->bp_role != BSTP_ROLE_DISABLED) {
1833 				bstp_disable_port(bs, bp);
1834 				changed = 1;
1835 				if ((bp->bp_flags & BSTP_PORT_ADMEDGE) &&
1836 				    bp->bp_protover == BSTP_PROTO_RSTP)
1837 					bp->bp_operedge = 1;
1838 			}
1839 		}
1840 	} else if (bp->bp_infois != BSTP_INFO_DISABLED) {
1841 		bstp_disable_port(bs, bp);
1842 		changed = 1;
1843 	}
1844 	if (changed)
1845 		bstp_assign_roles(bs);
1846 	BSTP_UNLOCK(bs);
1847 }
1848 
1849 static void
1850 bstp_enable_port(struct bstp_state *bs, struct bstp_port *bp)
1851 {
1852 	bp->bp_infois = BSTP_INFO_AGED;
1853 }
1854 
1855 static void
1856 bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
1857 {
1858 	bp->bp_infois = BSTP_INFO_DISABLED;
1859 }
1860 
1861 static void
1862 bstp_tick(void *arg)
1863 {
1864 	struct bstp_state *bs = arg;
1865 	struct bstp_port *bp;
1866 
1867 	BSTP_LOCK_ASSERT(bs);
1868 
1869 	if (bs->bs_running == 0)
1870 		return;
1871 
1872 	CURVNET_SET(bs->bs_vnet);
1873 
1874 	/* poll link events on interfaces that do not support linkstate */
1875 	if (bstp_timer_dectest(&bs->bs_link_timer)) {
1876 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1877 			if (!(bp->bp_ifp->if_capabilities & IFCAP_LINKSTATE))
1878 				taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
1879 		}
1880 		bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
1881 	}
1882 
1883 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1884 		/* no events need to happen for these */
1885 		bstp_timer_dectest(&bp->bp_tc_timer);
1886 		bstp_timer_dectest(&bp->bp_recent_root_timer);
1887 		bstp_timer_dectest(&bp->bp_forward_delay_timer);
1888 		bstp_timer_dectest(&bp->bp_recent_backup_timer);
1889 
1890 		if (bstp_timer_dectest(&bp->bp_hello_timer))
1891 			bstp_hello_timer_expiry(bs, bp);
1892 
1893 		if (bstp_timer_dectest(&bp->bp_message_age_timer))
1894 			bstp_message_age_expiry(bs, bp);
1895 
1896 		if (bstp_timer_dectest(&bp->bp_migrate_delay_timer))
1897 			bstp_migrate_delay_expiry(bs, bp);
1898 
1899 		if (bstp_timer_dectest(&bp->bp_edge_delay_timer))
1900 			bstp_edge_delay_expiry(bs, bp);
1901 
1902 		/* update the various state machines for the port */
1903 		bstp_update_state(bs, bp);
1904 
1905 		if (bp->bp_txcount > 0)
1906 			bp->bp_txcount--;
1907 	}
1908 
1909 	CURVNET_RESTORE();
1910 
1911 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
1912 }
1913 
1914 static void
1915 bstp_timer_start(struct bstp_timer *t, uint16_t v)
1916 {
1917 	t->value = v;
1918 	t->active = 1;
1919 	t->latched = 0;
1920 }
1921 
1922 static void
1923 bstp_timer_stop(struct bstp_timer *t)
1924 {
1925 	t->value = 0;
1926 	t->active = 0;
1927 	t->latched = 0;
1928 }
1929 
1930 static void
1931 bstp_timer_latch(struct bstp_timer *t)
1932 {
1933 	t->latched = 1;
1934 	t->active = 1;
1935 }
1936 
1937 static int
1938 bstp_timer_dectest(struct bstp_timer *t)
1939 {
1940 	if (t->active == 0 || t->latched)
1941 		return (0);
1942 	t->value -= BSTP_TICK_VAL;
1943 	if (t->value <= 0) {
1944 		bstp_timer_stop(t);
1945 		return (1);
1946 	}
1947 	return (0);
1948 }
1949 
1950 static void
1951 bstp_hello_timer_expiry(struct bstp_state *bs, struct bstp_port *bp)
1952 {
1953 	if ((bp->bp_flags & BSTP_PORT_NEWINFO) ||
1954 	    bp->bp_role == BSTP_ROLE_DESIGNATED ||
1955 	    (bp->bp_role == BSTP_ROLE_ROOT &&
1956 	     bp->bp_tc_timer.active == 1)) {
1957 		bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
1958 		bp->bp_flags |= BSTP_PORT_NEWINFO;
1959 		bstp_transmit(bs, bp);
1960 	}
1961 }
1962 
1963 static void
1964 bstp_message_age_expiry(struct bstp_state *bs, struct bstp_port *bp)
1965 {
1966 	if (bp->bp_infois == BSTP_INFO_RECEIVED) {
1967 		bp->bp_infois = BSTP_INFO_AGED;
1968 		bstp_assign_roles(bs);
1969 		DPRINTF("aged info on %s\n", bp->bp_ifp->if_xname);
1970 	}
1971 }
1972 
1973 static void
1974 bstp_migrate_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1975 {
1976 	bp->bp_flags |= BSTP_PORT_CANMIGRATE;
1977 }
1978 
1979 static void
1980 bstp_edge_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1981 {
1982 	if ((bp->bp_flags & BSTP_PORT_AUTOEDGE) &&
1983 	    bp->bp_protover == BSTP_PROTO_RSTP && bp->bp_proposing &&
1984 	    bp->bp_role == BSTP_ROLE_DESIGNATED) {
1985 		bp->bp_operedge = 1;
1986 		DPRINTF("%s -> edge port\n", bp->bp_ifp->if_xname);
1987 	}
1988 }
1989 
1990 static int
1991 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
1992 {
1993 	int i, d;
1994 
1995 	for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
1996 		d = ((int)a[i]) - ((int)b[i]);
1997 	}
1998 
1999 	return (d);
2000 }
2001 
2002 /*
2003  * compare the bridge address component of the bridgeid
2004  */
2005 static int
2006 bstp_same_bridgeid(uint64_t id1, uint64_t id2)
2007 {
2008 	u_char addr1[ETHER_ADDR_LEN];
2009 	u_char addr2[ETHER_ADDR_LEN];
2010 
2011 	PV2ADDR(id1, addr1);
2012 	PV2ADDR(id2, addr2);
2013 
2014 	if (bstp_addr_cmp(addr1, addr2) == 0)
2015 		return (1);
2016 
2017 	return (0);
2018 }
2019 
2020 void
2021 bstp_reinit(struct bstp_state *bs)
2022 {
2023 	struct bstp_port *bp;
2024 	struct ifnet *ifp, *mif;
2025 	u_char *e_addr;
2026 	void *bridgeptr;
2027 	static const u_char llzero[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */
2028 
2029 	BSTP_LOCK_ASSERT(bs);
2030 
2031 	if (LIST_EMPTY(&bs->bs_bplist))
2032 		goto disablestp;
2033 
2034 	mif = NULL;
2035 	bridgeptr = LIST_FIRST(&bs->bs_bplist)->bp_ifp->if_bridge;
2036 	KASSERT(bridgeptr != NULL, ("Invalid bridge pointer"));
2037 	/*
2038 	 * Search through the Ethernet adapters and find the one with the
2039 	 * lowest value. Make sure the adapter which we take the MAC address
2040 	 * from is part of this bridge, so we can have more than one independent
2041 	 * bridges in the same STP domain.
2042 	 */
2043 	IFNET_RLOCK_NOSLEEP();
2044 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2045 		if (ifp->if_type != IFT_ETHER)
2046 			continue;	/* Not Ethernet */
2047 
2048 		if (ifp->if_bridge != bridgeptr)
2049 			continue;	/* Not part of our bridge */
2050 
2051 		if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
2052 			continue;	/* No mac address set */
2053 
2054 		if (mif == NULL) {
2055 			mif = ifp;
2056 			continue;
2057 		}
2058 		if (bstp_addr_cmp(IF_LLADDR(ifp), IF_LLADDR(mif)) < 0) {
2059 			mif = ifp;
2060 			continue;
2061 		}
2062 	}
2063 	IFNET_RUNLOCK_NOSLEEP();
2064 	if (mif == NULL)
2065 		goto disablestp;
2066 
2067 	e_addr = IF_LLADDR(mif);
2068 	bs->bs_bridge_pv.pv_dbridge_id =
2069 	    (((uint64_t)bs->bs_bridge_priority) << 48) |
2070 	    (((uint64_t)e_addr[0]) << 40) |
2071 	    (((uint64_t)e_addr[1]) << 32) |
2072 	    (((uint64_t)e_addr[2]) << 24) |
2073 	    (((uint64_t)e_addr[3]) << 16) |
2074 	    (((uint64_t)e_addr[4]) << 8) |
2075 	    (((uint64_t)e_addr[5]));
2076 
2077 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2078 	bs->bs_bridge_pv.pv_cost = 0;
2079 	bs->bs_bridge_pv.pv_dport_id = 0;
2080 	bs->bs_bridge_pv.pv_port_id = 0;
2081 
2082 	if (bs->bs_running && callout_pending(&bs->bs_bstpcallout) == 0)
2083 		callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2084 
2085 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2086 		bp->bp_port_id = (bp->bp_priority << 8) |
2087 		    (bp->bp_ifp->if_index  & 0xfff);
2088 		taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
2089 	}
2090 
2091 	bstp_assign_roles(bs);
2092 	bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
2093 	return;
2094 
2095 disablestp:
2096 	/* Set the bridge and root id (lower bits) to zero */
2097 	bs->bs_bridge_pv.pv_dbridge_id =
2098 	    ((uint64_t)bs->bs_bridge_priority) << 48;
2099 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2100 	bs->bs_root_pv = bs->bs_bridge_pv;
2101 	/* Disable any remaining ports, they will have no MAC address */
2102 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2103 		bp->bp_infois = BSTP_INFO_DISABLED;
2104 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2105 	}
2106 	callout_stop(&bs->bs_bstpcallout);
2107 }
2108 
2109 static int
2110 bstp_modevent(module_t mod, int type, void *data)
2111 {
2112 	switch (type) {
2113 	case MOD_LOAD:
2114 		mtx_init(&bstp_list_mtx, "bridgestp list", NULL, MTX_DEF);
2115 		LIST_INIT(&bstp_list);
2116 		break;
2117 	case MOD_UNLOAD:
2118 		mtx_destroy(&bstp_list_mtx);
2119 		break;
2120 	default:
2121 		return (EOPNOTSUPP);
2122 	}
2123 	return (0);
2124 }
2125 
2126 static moduledata_t bstp_mod = {
2127 	"bridgestp",
2128 	bstp_modevent,
2129 	0
2130 };
2131 
2132 DECLARE_MODULE(bridgestp, bstp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2133 MODULE_VERSION(bridgestp, 1);
2134 
2135 void
2136 bstp_attach(struct bstp_state *bs, struct bstp_cb_ops *cb)
2137 {
2138 	BSTP_LOCK_INIT(bs);
2139 	callout_init_mtx(&bs->bs_bstpcallout, &bs->bs_mtx, 0);
2140 	LIST_INIT(&bs->bs_bplist);
2141 
2142 	bs->bs_bridge_max_age = BSTP_DEFAULT_MAX_AGE;
2143 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
2144 	bs->bs_bridge_fdelay = BSTP_DEFAULT_FORWARD_DELAY;
2145 	bs->bs_bridge_priority = BSTP_DEFAULT_BRIDGE_PRIORITY;
2146 	bs->bs_hold_time = BSTP_DEFAULT_HOLD_TIME;
2147 	bs->bs_migration_delay = BSTP_DEFAULT_MIGRATE_DELAY;
2148 	bs->bs_txholdcount = BSTP_DEFAULT_HOLD_COUNT;
2149 	bs->bs_protover = BSTP_PROTO_RSTP;
2150 	bs->bs_state_cb = cb->bcb_state;
2151 	bs->bs_rtage_cb = cb->bcb_rtage;
2152 	bs->bs_vnet = curvnet;
2153 
2154 	getmicrotime(&bs->bs_last_tc_time);
2155 
2156 	mtx_lock(&bstp_list_mtx);
2157 	LIST_INSERT_HEAD(&bstp_list, bs, bs_list);
2158 	mtx_unlock(&bstp_list_mtx);
2159 }
2160 
2161 void
2162 bstp_detach(struct bstp_state *bs)
2163 {
2164 	KASSERT(LIST_EMPTY(&bs->bs_bplist), ("bstp still active"));
2165 
2166 	mtx_lock(&bstp_list_mtx);
2167 	LIST_REMOVE(bs, bs_list);
2168 	mtx_unlock(&bstp_list_mtx);
2169 	callout_drain(&bs->bs_bstpcallout);
2170 	BSTP_LOCK_DESTROY(bs);
2171 }
2172 
2173 void
2174 bstp_init(struct bstp_state *bs)
2175 {
2176 	BSTP_LOCK(bs);
2177 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2178 	bs->bs_running = 1;
2179 	bstp_reinit(bs);
2180 	BSTP_UNLOCK(bs);
2181 }
2182 
2183 void
2184 bstp_stop(struct bstp_state *bs)
2185 {
2186 	struct bstp_port *bp;
2187 
2188 	BSTP_LOCK(bs);
2189 
2190 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
2191 		bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2192 
2193 	bs->bs_running = 0;
2194 	callout_stop(&bs->bs_bstpcallout);
2195 	BSTP_UNLOCK(bs);
2196 }
2197 
2198 int
2199 bstp_create(struct bstp_state *bs, struct bstp_port *bp, struct ifnet *ifp)
2200 {
2201 	bzero(bp, sizeof(struct bstp_port));
2202 
2203 	BSTP_LOCK(bs);
2204 	bp->bp_ifp = ifp;
2205 	bp->bp_bs = bs;
2206 	bp->bp_priority = BSTP_DEFAULT_PORT_PRIORITY;
2207 	TASK_INIT(&bp->bp_statetask, 0, bstp_notify_state, bp);
2208 	TASK_INIT(&bp->bp_rtagetask, 0, bstp_notify_rtage, bp);
2209 	TASK_INIT(&bp->bp_mediatask, 0, bstp_ifupdstatus, bp);
2210 
2211 	/* Init state */
2212 	bp->bp_infois = BSTP_INFO_DISABLED;
2213 	bp->bp_flags = BSTP_PORT_AUTOEDGE|BSTP_PORT_AUTOPTP;
2214 	bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2215 	bstp_set_port_proto(bp, bs->bs_protover);
2216 	bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2217 	bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
2218 	bp->bp_path_cost = bstp_calc_path_cost(bp);
2219 	BSTP_UNLOCK(bs);
2220 	return (0);
2221 }
2222 
2223 int
2224 bstp_enable(struct bstp_port *bp)
2225 {
2226 	struct bstp_state *bs = bp->bp_bs;
2227 	struct ifnet *ifp = bp->bp_ifp;
2228 
2229 	KASSERT(bp->bp_active == 0, ("already a bstp member"));
2230 
2231 	switch (ifp->if_type) {
2232 		case IFT_ETHER:	/* These can do spanning tree. */
2233 			break;
2234 		default:
2235 			/* Nothing else can. */
2236 			return (EINVAL);
2237 	}
2238 
2239 	BSTP_LOCK(bs);
2240 	LIST_INSERT_HEAD(&bs->bs_bplist, bp, bp_next);
2241 	bp->bp_active = 1;
2242 	bp->bp_flags |= BSTP_PORT_NEWINFO;
2243 	bstp_reinit(bs);
2244 	bstp_update_roles(bs, bp);
2245 	BSTP_UNLOCK(bs);
2246 	return (0);
2247 }
2248 
2249 void
2250 bstp_disable(struct bstp_port *bp)
2251 {
2252 	struct bstp_state *bs = bp->bp_bs;
2253 
2254 	KASSERT(bp->bp_active == 1, ("not a bstp member"));
2255 
2256 	BSTP_LOCK(bs);
2257 	bstp_disable_port(bs, bp);
2258 	LIST_REMOVE(bp, bp_next);
2259 	bp->bp_active = 0;
2260 	bstp_reinit(bs);
2261 	BSTP_UNLOCK(bs);
2262 }
2263 
2264 /*
2265  * The bstp_port structure is about to be freed by the parent bridge.
2266  */
2267 void
2268 bstp_destroy(struct bstp_port *bp)
2269 {
2270 	KASSERT(bp->bp_active == 0, ("port is still attached"));
2271 	taskqueue_drain(taskqueue_swi, &bp->bp_statetask);
2272 	taskqueue_drain(taskqueue_swi, &bp->bp_rtagetask);
2273 	taskqueue_drain(taskqueue_swi, &bp->bp_mediatask);
2274 }
2275