xref: /freebsd/sys/net/bridgestp.c (revision 410556f1f10fd35b350102725fd8504c3cb0afc8)
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 	NET_EPOCH_ASSERT();
158 
159 	if (bs->bs_running == 0)
160 		return;
161 
162 	/*
163 	 * a PDU can only be sent if we have tx quota left and the
164 	 * hello timer is running.
165 	 */
166 	if (bp->bp_hello_timer.active == 0) {
167 		/* Test if it needs to be reset */
168 		bstp_hello_timer_expiry(bs, bp);
169 		return;
170 	}
171 	if (bp->bp_txcount > bs->bs_txholdcount)
172 		/* Ran out of karma */
173 		return;
174 
175 	if (bp->bp_protover == BSTP_PROTO_RSTP) {
176 		bstp_transmit_bpdu(bs, bp);
177 		bp->bp_tc_ack = 0;
178 	} else { /* STP */
179 		switch (bp->bp_role) {
180 			case BSTP_ROLE_DESIGNATED:
181 				bstp_transmit_bpdu(bs, bp);
182 				bp->bp_tc_ack = 0;
183 				break;
184 
185 			case BSTP_ROLE_ROOT:
186 				bstp_transmit_tcn(bs, bp);
187 				break;
188 		}
189 	}
190 	bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
191 	bp->bp_flags &= ~BSTP_PORT_NEWINFO;
192 }
193 
194 static void
195 bstp_transmit_bpdu(struct bstp_state *bs, struct bstp_port *bp)
196 {
197 	struct bstp_cbpdu bpdu;
198 
199 	BSTP_LOCK_ASSERT(bs);
200 
201 	bpdu.cbu_rootpri = htons(bp->bp_desg_pv.pv_root_id >> 48);
202 	PV2ADDR(bp->bp_desg_pv.pv_root_id, bpdu.cbu_rootaddr);
203 
204 	bpdu.cbu_rootpathcost = htonl(bp->bp_desg_pv.pv_cost);
205 
206 	bpdu.cbu_bridgepri = htons(bp->bp_desg_pv.pv_dbridge_id >> 48);
207 	PV2ADDR(bp->bp_desg_pv.pv_dbridge_id, bpdu.cbu_bridgeaddr);
208 
209 	bpdu.cbu_portid = htons(bp->bp_port_id);
210 	bpdu.cbu_messageage = htons(bp->bp_desg_msg_age);
211 	bpdu.cbu_maxage = htons(bp->bp_desg_max_age);
212 	bpdu.cbu_hellotime = htons(bp->bp_desg_htime);
213 	bpdu.cbu_forwarddelay = htons(bp->bp_desg_fdelay);
214 
215 	bpdu.cbu_flags = bstp_pdu_flags(bp);
216 
217 	switch (bp->bp_protover) {
218 		case BSTP_PROTO_STP:
219 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_CFG;
220 			break;
221 
222 		case BSTP_PROTO_RSTP:
223 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_RSTP;
224 			break;
225 	}
226 
227 	bstp_send_bpdu(bs, bp, &bpdu);
228 }
229 
230 static void
231 bstp_transmit_tcn(struct bstp_state *bs, struct bstp_port *bp)
232 {
233 	struct bstp_tbpdu bpdu;
234 	struct ifnet *ifp = bp->bp_ifp;
235 	struct ether_header *eh;
236 	struct mbuf *m;
237 
238 	KASSERT(bp == bs->bs_root_port, ("%s: bad root port\n", __func__));
239 
240 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
241 		return;
242 
243 	m = m_gethdr(M_NOWAIT, MT_DATA);
244 	if (m == NULL)
245 		return;
246 
247 	m->m_pkthdr.rcvif = ifp;
248 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
249 	m->m_len = m->m_pkthdr.len;
250 
251 	eh = mtod(m, struct ether_header *);
252 
253 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
254 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
255 	eh->ether_type = htons(sizeof(bpdu));
256 
257 	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
258 	bpdu.tbu_ctl = LLC_UI;
259 	bpdu.tbu_protoid = 0;
260 	bpdu.tbu_protover = 0;
261 	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
262 
263 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
264 
265 	bp->bp_txcount++;
266 	ifp->if_transmit(ifp, m);
267 }
268 
269 static void
270 bstp_decode_bpdu(struct bstp_port *bp, struct bstp_cbpdu *cpdu,
271     struct bstp_config_unit *cu)
272 {
273 	int flags;
274 
275 	cu->cu_pv.pv_root_id =
276 	    (((uint64_t)ntohs(cpdu->cbu_rootpri)) << 48) |
277 	    (((uint64_t)cpdu->cbu_rootaddr[0]) << 40) |
278 	    (((uint64_t)cpdu->cbu_rootaddr[1]) << 32) |
279 	    (((uint64_t)cpdu->cbu_rootaddr[2]) << 24) |
280 	    (((uint64_t)cpdu->cbu_rootaddr[3]) << 16) |
281 	    (((uint64_t)cpdu->cbu_rootaddr[4]) << 8) |
282 	    (((uint64_t)cpdu->cbu_rootaddr[5]) << 0);
283 
284 	cu->cu_pv.pv_dbridge_id =
285 	    (((uint64_t)ntohs(cpdu->cbu_bridgepri)) << 48) |
286 	    (((uint64_t)cpdu->cbu_bridgeaddr[0]) << 40) |
287 	    (((uint64_t)cpdu->cbu_bridgeaddr[1]) << 32) |
288 	    (((uint64_t)cpdu->cbu_bridgeaddr[2]) << 24) |
289 	    (((uint64_t)cpdu->cbu_bridgeaddr[3]) << 16) |
290 	    (((uint64_t)cpdu->cbu_bridgeaddr[4]) << 8) |
291 	    (((uint64_t)cpdu->cbu_bridgeaddr[5]) << 0);
292 
293 	cu->cu_pv.pv_cost = ntohl(cpdu->cbu_rootpathcost);
294 	cu->cu_message_age = ntohs(cpdu->cbu_messageage);
295 	cu->cu_max_age = ntohs(cpdu->cbu_maxage);
296 	cu->cu_hello_time = ntohs(cpdu->cbu_hellotime);
297 	cu->cu_forward_delay = ntohs(cpdu->cbu_forwarddelay);
298 	cu->cu_pv.pv_dport_id = ntohs(cpdu->cbu_portid);
299 	cu->cu_pv.pv_port_id = bp->bp_port_id;
300 	cu->cu_message_type = cpdu->cbu_bpdutype;
301 
302 	/* Strip off unused flags in STP mode */
303 	flags = cpdu->cbu_flags;
304 	switch (cpdu->cbu_protover) {
305 		case BSTP_PROTO_STP:
306 			flags &= BSTP_PDU_STPMASK;
307 			/* A STP BPDU explicitly conveys a Designated Port */
308 			cu->cu_role = BSTP_ROLE_DESIGNATED;
309 			break;
310 
311 		case BSTP_PROTO_RSTP:
312 			flags &= BSTP_PDU_RSTPMASK;
313 			break;
314 	}
315 
316 	cu->cu_topology_change_ack =
317 		(flags & BSTP_PDU_F_TCA) ? 1 : 0;
318 	cu->cu_proposal =
319 		(flags & BSTP_PDU_F_P) ? 1 : 0;
320 	cu->cu_agree =
321 		(flags & BSTP_PDU_F_A) ? 1 : 0;
322 	cu->cu_learning =
323 		(flags & BSTP_PDU_F_L) ? 1 : 0;
324 	cu->cu_forwarding =
325 		(flags & BSTP_PDU_F_F) ? 1 : 0;
326 	cu->cu_topology_change =
327 		(flags & BSTP_PDU_F_TC) ? 1 : 0;
328 
329 	switch ((flags & BSTP_PDU_PRMASK) >> BSTP_PDU_PRSHIFT) {
330 		case BSTP_PDU_F_ROOT:
331 			cu->cu_role = BSTP_ROLE_ROOT;
332 			break;
333 		case BSTP_PDU_F_ALT:
334 			cu->cu_role = BSTP_ROLE_ALTERNATE;
335 			break;
336 		case BSTP_PDU_F_DESG:
337 			cu->cu_role = BSTP_ROLE_DESIGNATED;
338 			break;
339 	}
340 }
341 
342 static void
343 bstp_send_bpdu(struct bstp_state *bs, struct bstp_port *bp,
344     struct bstp_cbpdu *bpdu)
345 {
346 	struct ifnet *ifp;
347 	struct mbuf *m;
348 	struct ether_header *eh;
349 
350 	BSTP_LOCK_ASSERT(bs);
351 	NET_EPOCH_ASSERT();
352 
353 	ifp = bp->bp_ifp;
354 
355 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
356 		return;
357 
358 	m = m_gethdr(M_NOWAIT, MT_DATA);
359 	if (m == NULL)
360 		return;
361 
362 	eh = mtod(m, struct ether_header *);
363 
364 	bpdu->cbu_ssap = bpdu->cbu_dsap = LLC_8021D_LSAP;
365 	bpdu->cbu_ctl = LLC_UI;
366 	bpdu->cbu_protoid = htons(BSTP_PROTO_ID);
367 
368 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
369 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
370 
371 	switch (bpdu->cbu_bpdutype) {
372 		case BSTP_MSGTYPE_CFG:
373 			bpdu->cbu_protover = BSTP_PROTO_STP;
374 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_STP_LEN;
375 			eh->ether_type = htons(BSTP_BPDU_STP_LEN);
376 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
377 			    BSTP_BPDU_STP_LEN);
378 			break;
379 
380 		case BSTP_MSGTYPE_RSTP:
381 			bpdu->cbu_protover = BSTP_PROTO_RSTP;
382 			bpdu->cbu_versionlen = htons(0);
383 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_RSTP_LEN;
384 			eh->ether_type = htons(BSTP_BPDU_RSTP_LEN);
385 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
386 			    BSTP_BPDU_RSTP_LEN);
387 			break;
388 
389 		default:
390 			panic("not implemented");
391 	}
392 	m->m_pkthdr.rcvif = ifp;
393 	m->m_len = m->m_pkthdr.len;
394 
395 	bp->bp_txcount++;
396 	ifp->if_transmit(ifp, m);
397 }
398 
399 static int
400 bstp_pdu_flags(struct bstp_port *bp)
401 {
402 	int flags = 0;
403 
404 	if (bp->bp_proposing && bp->bp_state != BSTP_IFSTATE_FORWARDING)
405 		flags |= BSTP_PDU_F_P;
406 
407 	if (bp->bp_agree)
408 		flags |= BSTP_PDU_F_A;
409 
410 	if (bp->bp_tc_timer.active)
411 		flags |= BSTP_PDU_F_TC;
412 
413 	if (bp->bp_tc_ack)
414 		flags |= BSTP_PDU_F_TCA;
415 
416 	switch (bp->bp_state) {
417 		case BSTP_IFSTATE_LEARNING:
418 			flags |= BSTP_PDU_F_L;
419 			break;
420 
421 		case BSTP_IFSTATE_FORWARDING:
422 			flags |= (BSTP_PDU_F_L | BSTP_PDU_F_F);
423 			break;
424 	}
425 
426 	switch (bp->bp_role) {
427 		case BSTP_ROLE_ROOT:
428 			flags |=
429 				(BSTP_PDU_F_ROOT << BSTP_PDU_PRSHIFT);
430 			break;
431 
432 		case BSTP_ROLE_ALTERNATE:
433 		case BSTP_ROLE_BACKUP:	/* fall through */
434 			flags |=
435 				(BSTP_PDU_F_ALT << BSTP_PDU_PRSHIFT);
436 			break;
437 
438 		case BSTP_ROLE_DESIGNATED:
439 			flags |=
440 				(BSTP_PDU_F_DESG << BSTP_PDU_PRSHIFT);
441 			break;
442 	}
443 
444 	/* Strip off unused flags in either mode */
445 	switch (bp->bp_protover) {
446 		case BSTP_PROTO_STP:
447 			flags &= BSTP_PDU_STPMASK;
448 			break;
449 		case BSTP_PROTO_RSTP:
450 			flags &= BSTP_PDU_RSTPMASK;
451 			break;
452 	}
453 	return (flags);
454 }
455 
456 void
457 bstp_input(struct bstp_port *bp, struct ifnet *ifp, struct mbuf *m)
458 {
459 	struct bstp_state *bs = bp->bp_bs;
460 	struct ether_header *eh;
461 	struct bstp_tbpdu tpdu;
462 	uint16_t len;
463 
464 	if (bp->bp_active == 0) {
465 		m_freem(m);
466 		return;
467 	}
468 
469 	BSTP_LOCK(bs);
470 
471 	eh = mtod(m, struct ether_header *);
472 
473 	len = ntohs(eh->ether_type);
474 	if (len < sizeof(tpdu))
475 		goto out;
476 
477 	m_adj(m, ETHER_HDR_LEN);
478 
479 	if (m->m_pkthdr.len > len)
480 		m_adj(m, len - m->m_pkthdr.len);
481 	if (m->m_len < sizeof(tpdu) &&
482 	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
483 		goto out;
484 
485 	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
486 
487 	/* basic packet checks */
488 	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
489 	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
490 	    tpdu.tbu_ctl != LLC_UI)
491 		goto out;
492 	if (tpdu.tbu_protoid != BSTP_PROTO_ID)
493 		goto out;
494 
495 	/*
496 	 * We can treat later versions of the PDU as the same as the maximum
497 	 * version we implement. All additional parameters/flags are ignored.
498 	 */
499 	if (tpdu.tbu_protover > BSTP_PROTO_MAX)
500 		tpdu.tbu_protover = BSTP_PROTO_MAX;
501 
502 	if (tpdu.tbu_protover != bp->bp_protover) {
503 		/*
504 		 * Wait for the migration delay timer to expire before changing
505 		 * protocol version to avoid flip-flops.
506 		 */
507 		if (bp->bp_flags & BSTP_PORT_CANMIGRATE)
508 			bstp_set_port_proto(bp, tpdu.tbu_protover);
509 		else
510 			goto out;
511 	}
512 
513 	/* Clear operedge upon receiving a PDU on the port */
514 	bp->bp_operedge = 0;
515 	bstp_timer_start(&bp->bp_edge_delay_timer,
516 	    BSTP_DEFAULT_MIGRATE_DELAY);
517 
518 	switch (tpdu.tbu_protover) {
519 		case BSTP_PROTO_STP:
520 			bstp_received_stp(bs, bp, &m, &tpdu);
521 			break;
522 
523 		case BSTP_PROTO_RSTP:
524 			bstp_received_rstp(bs, bp, &m, &tpdu);
525 			break;
526 	}
527 out:
528 	BSTP_UNLOCK(bs);
529 	if (m)
530 		m_freem(m);
531 }
532 
533 static void
534 bstp_received_stp(struct bstp_state *bs, struct bstp_port *bp,
535     struct mbuf **mp, struct bstp_tbpdu *tpdu)
536 {
537 	struct bstp_cbpdu cpdu;
538 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
539 	struct bstp_tcn_unit tu;
540 
541 	switch (tpdu->tbu_bpdutype) {
542 	case BSTP_MSGTYPE_TCN:
543 		tu.tu_message_type = tpdu->tbu_bpdutype;
544 		bstp_received_tcn(bs, bp, &tu);
545 		break;
546 	case BSTP_MSGTYPE_CFG:
547 		if ((*mp)->m_len < BSTP_BPDU_STP_LEN &&
548 		    (*mp = m_pullup(*mp, BSTP_BPDU_STP_LEN)) == NULL)
549 			return;
550 		memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_STP_LEN);
551 
552 		bstp_decode_bpdu(bp, &cpdu, cu);
553 		bstp_received_bpdu(bs, bp, cu);
554 		break;
555 	}
556 }
557 
558 static void
559 bstp_received_rstp(struct bstp_state *bs, struct bstp_port *bp,
560     struct mbuf **mp, struct bstp_tbpdu *tpdu)
561 {
562 	struct bstp_cbpdu cpdu;
563 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
564 
565 	if (tpdu->tbu_bpdutype != BSTP_MSGTYPE_RSTP)
566 		return;
567 
568 	if ((*mp)->m_len < BSTP_BPDU_RSTP_LEN &&
569 	    (*mp = m_pullup(*mp, BSTP_BPDU_RSTP_LEN)) == NULL)
570 		return;
571 	memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_RSTP_LEN);
572 
573 	bstp_decode_bpdu(bp, &cpdu, cu);
574 	bstp_received_bpdu(bs, bp, cu);
575 }
576 
577 static void
578 bstp_received_tcn(struct bstp_state *bs, struct bstp_port *bp,
579     struct bstp_tcn_unit *tcn)
580 {
581 	bp->bp_rcvdtcn = 1;
582 	bstp_update_tc(bp);
583 }
584 
585 static void
586 bstp_received_bpdu(struct bstp_state *bs, struct bstp_port *bp,
587     struct bstp_config_unit *cu)
588 {
589 	int type;
590 
591 	BSTP_LOCK_ASSERT(bs);
592 
593 	/* We need to have transitioned to INFO_MINE before proceeding */
594 	switch (bp->bp_infois) {
595 		case BSTP_INFO_DISABLED:
596 		case BSTP_INFO_AGED:
597 			return;
598 	}
599 
600 	type = bstp_pdu_rcvtype(bp, cu);
601 
602 	switch (type) {
603 		case BSTP_PDU_SUPERIOR:
604 			bs->bs_allsynced = 0;
605 			bp->bp_agreed = 0;
606 			bp->bp_proposing = 0;
607 
608 			if (cu->cu_proposal && cu->cu_forwarding == 0)
609 				bp->bp_proposed = 1;
610 			if (cu->cu_topology_change)
611 				bp->bp_rcvdtc = 1;
612 			if (cu->cu_topology_change_ack)
613 				bp->bp_rcvdtca = 1;
614 
615 			if (bp->bp_agree &&
616 			    !bstp_pdu_bettersame(bp, BSTP_INFO_RECEIVED))
617 				bp->bp_agree = 0;
618 
619 			/* copy the received priority and timers to the port */
620 			bp->bp_port_pv = cu->cu_pv;
621 			bp->bp_port_msg_age = cu->cu_message_age;
622 			bp->bp_port_max_age = cu->cu_max_age;
623 			bp->bp_port_fdelay = cu->cu_forward_delay;
624 			bp->bp_port_htime =
625 				(cu->cu_hello_time > BSTP_MIN_HELLO_TIME ?
626 				 cu->cu_hello_time : BSTP_MIN_HELLO_TIME);
627 
628 			/* set expiry for the new info */
629 			bstp_set_timer_msgage(bp);
630 
631 			bp->bp_infois = BSTP_INFO_RECEIVED;
632 			bstp_assign_roles(bs);
633 			break;
634 
635 		case BSTP_PDU_REPEATED:
636 			if (cu->cu_proposal && cu->cu_forwarding == 0)
637 				bp->bp_proposed = 1;
638 			if (cu->cu_topology_change)
639 				bp->bp_rcvdtc = 1;
640 			if (cu->cu_topology_change_ack)
641 				bp->bp_rcvdtca = 1;
642 
643 			/* rearm the age timer */
644 			bstp_set_timer_msgage(bp);
645 			break;
646 
647 		case BSTP_PDU_INFERIOR:
648 			if (cu->cu_learning) {
649 				bp->bp_agreed = 1;
650 				bp->bp_proposing = 0;
651 			}
652 			break;
653 
654 		case BSTP_PDU_INFERIORALT:
655 			/*
656 			 * only point to point links are allowed fast
657 			 * transitions to forwarding.
658 			 */
659 			if (cu->cu_agree && bp->bp_ptp_link) {
660 				bp->bp_agreed = 1;
661 				bp->bp_proposing = 0;
662 			} else
663 				bp->bp_agreed = 0;
664 
665 			if (cu->cu_topology_change)
666 				bp->bp_rcvdtc = 1;
667 			if (cu->cu_topology_change_ack)
668 				bp->bp_rcvdtca = 1;
669 			break;
670 
671 		case BSTP_PDU_OTHER:
672 			return;	/* do nothing */
673 	}
674 	/* update the state machines with the new data */
675 	bstp_update_state(bs, bp);
676 }
677 
678 static int
679 bstp_pdu_rcvtype(struct bstp_port *bp, struct bstp_config_unit *cu)
680 {
681 	int type;
682 
683 	/* default return type */
684 	type = BSTP_PDU_OTHER;
685 
686 	switch (cu->cu_role) {
687 	case BSTP_ROLE_DESIGNATED:
688 		if (bstp_info_superior(&bp->bp_port_pv, &cu->cu_pv))
689 			/* bpdu priority is superior */
690 			type = BSTP_PDU_SUPERIOR;
691 		else if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) ==
692 		    INFO_SAME) {
693 			if (bp->bp_port_msg_age != cu->cu_message_age ||
694 			    bp->bp_port_max_age != cu->cu_max_age ||
695 			    bp->bp_port_fdelay != cu->cu_forward_delay ||
696 			    bp->bp_port_htime != cu->cu_hello_time)
697 				/* bpdu priority is equal and timers differ */
698 				type = BSTP_PDU_SUPERIOR;
699 			else
700 				/* bpdu is equal */
701 				type = BSTP_PDU_REPEATED;
702 		} else
703 			/* bpdu priority is worse */
704 			type = BSTP_PDU_INFERIOR;
705 
706 		break;
707 
708 	case BSTP_ROLE_ROOT:
709 	case BSTP_ROLE_ALTERNATE:
710 	case BSTP_ROLE_BACKUP:
711 		if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) <= INFO_SAME)
712 			/*
713 			 * not a designated port and priority is the same or
714 			 * worse
715 			 */
716 			type = BSTP_PDU_INFERIORALT;
717 		break;
718 	}
719 
720 	return (type);
721 }
722 
723 static int
724 bstp_pdu_bettersame(struct bstp_port *bp, int newinfo)
725 {
726 	if (newinfo == BSTP_INFO_RECEIVED &&
727 	    bp->bp_infois == BSTP_INFO_RECEIVED &&
728 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_msg_cu.cu_pv) >= INFO_SAME)
729 		return (1);
730 
731 	if (newinfo == BSTP_INFO_MINE &&
732 	    bp->bp_infois == BSTP_INFO_MINE &&
733 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_desg_pv) >= INFO_SAME)
734 		return (1);
735 
736 	return (0);
737 }
738 
739 static int
740 bstp_info_cmp(struct bstp_pri_vector *pv,
741     struct bstp_pri_vector *cpv)
742 {
743 	if (cpv->pv_root_id < pv->pv_root_id)
744 		return (INFO_BETTER);
745 	if (cpv->pv_root_id > pv->pv_root_id)
746 		return (INFO_WORSE);
747 
748 	if (cpv->pv_cost < pv->pv_cost)
749 		return (INFO_BETTER);
750 	if (cpv->pv_cost > pv->pv_cost)
751 		return (INFO_WORSE);
752 
753 	if (cpv->pv_dbridge_id < pv->pv_dbridge_id)
754 		return (INFO_BETTER);
755 	if (cpv->pv_dbridge_id > pv->pv_dbridge_id)
756 		return (INFO_WORSE);
757 
758 	if (cpv->pv_dport_id < pv->pv_dport_id)
759 		return (INFO_BETTER);
760 	if (cpv->pv_dport_id > pv->pv_dport_id)
761 		return (INFO_WORSE);
762 
763 	return (INFO_SAME);
764 }
765 
766 /*
767  * This message priority vector is superior to the port priority vector and
768  * will replace it if, and only if, the message priority vector is better than
769  * the port priority vector, or the message has been transmitted from the same
770  * designated bridge and designated port as the port priority vector.
771  */
772 static int
773 bstp_info_superior(struct bstp_pri_vector *pv,
774     struct bstp_pri_vector *cpv)
775 {
776 	if (bstp_info_cmp(pv, cpv) == INFO_BETTER ||
777 	    (bstp_same_bridgeid(pv->pv_dbridge_id, cpv->pv_dbridge_id) &&
778 	    (cpv->pv_dport_id & 0xfff) == (pv->pv_dport_id & 0xfff)))
779 		return (1);
780 	return (0);
781 }
782 
783 static void
784 bstp_assign_roles(struct bstp_state *bs)
785 {
786 	struct bstp_port *bp, *rbp = NULL;
787 	struct bstp_pri_vector pv;
788 
789 	/* default to our priority vector */
790 	bs->bs_root_pv = bs->bs_bridge_pv;
791 	bs->bs_root_msg_age = 0;
792 	bs->bs_root_max_age = bs->bs_bridge_max_age;
793 	bs->bs_root_fdelay = bs->bs_bridge_fdelay;
794 	bs->bs_root_htime = bs->bs_bridge_htime;
795 	bs->bs_root_port = NULL;
796 
797 	/* check if any received info supersedes us */
798 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
799 		if (bp->bp_infois != BSTP_INFO_RECEIVED)
800 			continue;
801 
802 		pv = bp->bp_port_pv;
803 		pv.pv_cost += bp->bp_path_cost;
804 
805 		/*
806 		 * The root priority vector is the best of the set comprising
807 		 * the bridge priority vector plus all root path priority
808 		 * vectors whose bridge address is not equal to us.
809 		 */
810 		if (bstp_same_bridgeid(pv.pv_dbridge_id,
811 		    bs->bs_bridge_pv.pv_dbridge_id) == 0 &&
812 		    bstp_info_cmp(&bs->bs_root_pv, &pv) == INFO_BETTER) {
813 			/* the port vector replaces the root */
814 			bs->bs_root_pv = pv;
815 			bs->bs_root_msg_age = bp->bp_port_msg_age +
816 			    BSTP_MESSAGE_AGE_INCR;
817 			bs->bs_root_max_age = bp->bp_port_max_age;
818 			bs->bs_root_fdelay = bp->bp_port_fdelay;
819 			bs->bs_root_htime = bp->bp_port_htime;
820 			rbp = bp;
821 		}
822 	}
823 
824 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
825 		/* calculate the port designated vector */
826 		bp->bp_desg_pv.pv_root_id = bs->bs_root_pv.pv_root_id;
827 		bp->bp_desg_pv.pv_cost = bs->bs_root_pv.pv_cost;
828 		bp->bp_desg_pv.pv_dbridge_id = bs->bs_bridge_pv.pv_dbridge_id;
829 		bp->bp_desg_pv.pv_dport_id = bp->bp_port_id;
830 		bp->bp_desg_pv.pv_port_id = bp->bp_port_id;
831 
832 		/* calculate designated times */
833 		bp->bp_desg_msg_age = bs->bs_root_msg_age;
834 		bp->bp_desg_max_age = bs->bs_root_max_age;
835 		bp->bp_desg_fdelay = bs->bs_root_fdelay;
836 		bp->bp_desg_htime = bs->bs_bridge_htime;
837 
838 		switch (bp->bp_infois) {
839 		case BSTP_INFO_DISABLED:
840 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
841 			break;
842 
843 		case BSTP_INFO_AGED:
844 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
845 			bstp_update_info(bp);
846 			break;
847 
848 		case BSTP_INFO_MINE:
849 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
850 			/* update the port info if stale */
851 			if (bstp_info_cmp(&bp->bp_port_pv,
852 			    &bp->bp_desg_pv) != INFO_SAME ||
853 			    (rbp != NULL &&
854 			    (bp->bp_port_msg_age != rbp->bp_port_msg_age ||
855 			    bp->bp_port_max_age != rbp->bp_port_max_age ||
856 			    bp->bp_port_fdelay != rbp->bp_port_fdelay ||
857 			    bp->bp_port_htime != rbp->bp_port_htime)))
858 				bstp_update_info(bp);
859 			break;
860 
861 		case BSTP_INFO_RECEIVED:
862 			if (bp == rbp) {
863 				/*
864 				 * root priority is derived from this
865 				 * port, make it the root port.
866 				 */
867 				bstp_set_port_role(bp, BSTP_ROLE_ROOT);
868 				bs->bs_root_port = bp;
869 			} else if (bstp_info_cmp(&bp->bp_port_pv,
870 				    &bp->bp_desg_pv) == INFO_BETTER) {
871 				/*
872 				 * the port priority is lower than the root
873 				 * port.
874 				 */
875 				bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
876 				bstp_update_info(bp);
877 			} else {
878 				if (bstp_same_bridgeid(
879 				    bp->bp_port_pv.pv_dbridge_id,
880 				    bs->bs_bridge_pv.pv_dbridge_id)) {
881 					/*
882 					 * the designated bridge refers to
883 					 * another port on this bridge.
884 					 */
885 					bstp_set_port_role(bp,
886 					    BSTP_ROLE_BACKUP);
887 				} else {
888 					/*
889 					 * the port is an inferior path to the
890 					 * root bridge.
891 					 */
892 					bstp_set_port_role(bp,
893 					    BSTP_ROLE_ALTERNATE);
894 				}
895 			}
896 			break;
897 		}
898 	}
899 }
900 
901 static void
902 bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
903 {
904 	struct bstp_port *bp2;
905 	int synced;
906 
907 	BSTP_LOCK_ASSERT(bs);
908 
909 	/* check if all the ports have syncronised again */
910 	if (!bs->bs_allsynced) {
911 		synced = 1;
912 		LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
913 			if (!(bp2->bp_synced ||
914 			     bp2->bp_role == BSTP_ROLE_ROOT)) {
915 				synced = 0;
916 				break;
917 			}
918 		}
919 		bs->bs_allsynced = synced;
920 	}
921 
922 	bstp_update_roles(bs, bp);
923 	bstp_update_tc(bp);
924 }
925 
926 static void
927 bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
928 {
929 	NET_EPOCH_ASSERT();
930 
931 	switch (bp->bp_role) {
932 	case BSTP_ROLE_DISABLED:
933 		/* Clear any flags if set */
934 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
935 			bp->bp_sync = 0;
936 			bp->bp_synced = 1;
937 			bp->bp_reroot = 0;
938 		}
939 		break;
940 
941 	case BSTP_ROLE_ALTERNATE:
942 	case BSTP_ROLE_BACKUP:
943 		if ((bs->bs_allsynced && !bp->bp_agree) ||
944 		    (bp->bp_proposed && bp->bp_agree)) {
945 			bp->bp_proposed = 0;
946 			bp->bp_agree = 1;
947 			bp->bp_flags |= BSTP_PORT_NEWINFO;
948 			DPRINTF("%s -> ALTERNATE_AGREED\n",
949 			    bp->bp_ifp->if_xname);
950 		}
951 
952 		if (bp->bp_proposed && !bp->bp_agree) {
953 			bstp_set_all_sync(bs);
954 			bp->bp_proposed = 0;
955 			DPRINTF("%s -> ALTERNATE_PROPOSED\n",
956 			    bp->bp_ifp->if_xname);
957 		}
958 
959 		/* Clear any flags if set */
960 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
961 			bp->bp_sync = 0;
962 			bp->bp_synced = 1;
963 			bp->bp_reroot = 0;
964 			DPRINTF("%s -> ALTERNATE_PORT\n", bp->bp_ifp->if_xname);
965 		}
966 		break;
967 
968 	case BSTP_ROLE_ROOT:
969 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING && !bp->bp_reroot) {
970 			bstp_set_all_reroot(bs);
971 			DPRINTF("%s -> ROOT_REROOT\n", bp->bp_ifp->if_xname);
972 		}
973 
974 		if ((bs->bs_allsynced && !bp->bp_agree) ||
975 		    (bp->bp_proposed && bp->bp_agree)) {
976 			bp->bp_proposed = 0;
977 			bp->bp_sync = 0;
978 			bp->bp_agree = 1;
979 			bp->bp_flags |= BSTP_PORT_NEWINFO;
980 			DPRINTF("%s -> ROOT_AGREED\n", bp->bp_ifp->if_xname);
981 		}
982 
983 		if (bp->bp_proposed && !bp->bp_agree) {
984 			bstp_set_all_sync(bs);
985 			bp->bp_proposed = 0;
986 			DPRINTF("%s -> ROOT_PROPOSED\n", bp->bp_ifp->if_xname);
987 		}
988 
989 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
990 		    (bp->bp_forward_delay_timer.active == 0 ||
991 		    (bstp_rerooted(bs, bp) &&
992 		    bp->bp_recent_backup_timer.active == 0 &&
993 		    bp->bp_protover == BSTP_PROTO_RSTP))) {
994 			switch (bp->bp_state) {
995 			case BSTP_IFSTATE_DISCARDING:
996 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
997 				break;
998 			case BSTP_IFSTATE_LEARNING:
999 				bstp_set_port_state(bp,
1000 				    BSTP_IFSTATE_FORWARDING);
1001 				break;
1002 			}
1003 		}
1004 
1005 		if (bp->bp_state == BSTP_IFSTATE_FORWARDING && bp->bp_reroot) {
1006 			bp->bp_reroot = 0;
1007 			DPRINTF("%s -> ROOT_REROOTED\n", bp->bp_ifp->if_xname);
1008 		}
1009 		break;
1010 
1011 	case BSTP_ROLE_DESIGNATED:
1012 		if (bp->bp_recent_root_timer.active == 0 && bp->bp_reroot) {
1013 			bp->bp_reroot = 0;
1014 			DPRINTF("%s -> DESIGNATED_RETIRED\n",
1015 			    bp->bp_ifp->if_xname);
1016 		}
1017 
1018 		if ((bp->bp_state == BSTP_IFSTATE_DISCARDING &&
1019 		    !bp->bp_synced) || (bp->bp_agreed && !bp->bp_synced) ||
1020 		    (bp->bp_operedge && !bp->bp_synced) ||
1021 		    (bp->bp_sync && bp->bp_synced)) {
1022 			bstp_timer_stop(&bp->bp_recent_root_timer);
1023 			bp->bp_synced = 1;
1024 			bp->bp_sync = 0;
1025 			DPRINTF("%s -> DESIGNATED_SYNCED\n",
1026 			    bp->bp_ifp->if_xname);
1027 		}
1028 
1029 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1030 		    !bp->bp_agreed && !bp->bp_proposing &&
1031 		    !bp->bp_operedge) {
1032 			bp->bp_proposing = 1;
1033 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1034 			bstp_timer_start(&bp->bp_edge_delay_timer,
1035 			    (bp->bp_ptp_link ? BSTP_DEFAULT_MIGRATE_DELAY :
1036 			     bp->bp_desg_max_age));
1037 			DPRINTF("%s -> DESIGNATED_PROPOSE\n",
1038 			    bp->bp_ifp->if_xname);
1039 		}
1040 
1041 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1042 		    (bp->bp_forward_delay_timer.active == 0 || bp->bp_agreed ||
1043 		    bp->bp_operedge) &&
1044 		    (bp->bp_recent_root_timer.active == 0 || !bp->bp_reroot) &&
1045 		    !bp->bp_sync) {
1046 			if (bp->bp_agreed)
1047 				DPRINTF("%s -> AGREED\n", bp->bp_ifp->if_xname);
1048 			/*
1049 			 * If agreed|operedge then go straight to forwarding,
1050 			 * otherwise follow discard -> learn -> forward.
1051 			 */
1052 			if (bp->bp_agreed || bp->bp_operedge ||
1053 			    bp->bp_state == BSTP_IFSTATE_LEARNING) {
1054 				bstp_set_port_state(bp,
1055 				    BSTP_IFSTATE_FORWARDING);
1056 				bp->bp_agreed = bp->bp_protover;
1057 			} else if (bp->bp_state == BSTP_IFSTATE_DISCARDING)
1058 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
1059 		}
1060 
1061 		if (((bp->bp_sync && !bp->bp_synced) ||
1062 		    (bp->bp_reroot && bp->bp_recent_root_timer.active) ||
1063 		    (bp->bp_flags & BSTP_PORT_DISPUTED)) && !bp->bp_operedge &&
1064 		    bp->bp_state != BSTP_IFSTATE_DISCARDING) {
1065 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1066 			bp->bp_flags &= ~BSTP_PORT_DISPUTED;
1067 			bstp_timer_start(&bp->bp_forward_delay_timer,
1068 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1069 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1070 			DPRINTF("%s -> DESIGNATED_DISCARD\n",
1071 			    bp->bp_ifp->if_xname);
1072 		}
1073 		break;
1074 	}
1075 
1076 	if (bp->bp_flags & BSTP_PORT_NEWINFO)
1077 		bstp_transmit(bs, bp);
1078 }
1079 
1080 static void
1081 bstp_update_tc(struct bstp_port *bp)
1082 {
1083 	switch (bp->bp_tcstate) {
1084 		case BSTP_TCSTATE_ACTIVE:
1085 			if ((bp->bp_role != BSTP_ROLE_DESIGNATED &&
1086 			    bp->bp_role != BSTP_ROLE_ROOT) || bp->bp_operedge)
1087 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1088 
1089 			if (bp->bp_rcvdtcn)
1090 				bstp_set_port_tc(bp, BSTP_TCSTATE_TCN);
1091 			if (bp->bp_rcvdtc)
1092 				bstp_set_port_tc(bp, BSTP_TCSTATE_TC);
1093 
1094 			if (bp->bp_tc_prop && !bp->bp_operedge)
1095 				bstp_set_port_tc(bp, BSTP_TCSTATE_PROPAG);
1096 
1097 			if (bp->bp_rcvdtca)
1098 				bstp_set_port_tc(bp, BSTP_TCSTATE_ACK);
1099 			break;
1100 
1101 		case BSTP_TCSTATE_INACTIVE:
1102 			if ((bp->bp_state == BSTP_IFSTATE_LEARNING ||
1103 			    bp->bp_state == BSTP_IFSTATE_FORWARDING) &&
1104 			    bp->bp_fdbflush == 0)
1105 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1106 			break;
1107 
1108 		case BSTP_TCSTATE_LEARNING:
1109 			if (bp->bp_rcvdtc || bp->bp_rcvdtcn || bp->bp_rcvdtca ||
1110 			    bp->bp_tc_prop)
1111 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1112 			else if (bp->bp_role != BSTP_ROLE_DESIGNATED &&
1113 				 bp->bp_role != BSTP_ROLE_ROOT &&
1114 				 bp->bp_state == BSTP_IFSTATE_DISCARDING)
1115 				bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1116 
1117 			if ((bp->bp_role == BSTP_ROLE_DESIGNATED ||
1118 			    bp->bp_role == BSTP_ROLE_ROOT) &&
1119 			    bp->bp_state == BSTP_IFSTATE_FORWARDING &&
1120 			    !bp->bp_operedge)
1121 				bstp_set_port_tc(bp, BSTP_TCSTATE_DETECTED);
1122 			break;
1123 
1124 		/* these are transient states and go straight back to ACTIVE */
1125 		case BSTP_TCSTATE_DETECTED:
1126 		case BSTP_TCSTATE_TCN:
1127 		case BSTP_TCSTATE_TC:
1128 		case BSTP_TCSTATE_PROPAG:
1129 		case BSTP_TCSTATE_ACK:
1130 			DPRINTF("Invalid TC state for %s\n",
1131 			    bp->bp_ifp->if_xname);
1132 			break;
1133 	}
1134 
1135 }
1136 
1137 static void
1138 bstp_update_info(struct bstp_port *bp)
1139 {
1140 	struct bstp_state *bs = bp->bp_bs;
1141 
1142 	bp->bp_proposing = 0;
1143 	bp->bp_proposed = 0;
1144 
1145 	if (bp->bp_agreed && !bstp_pdu_bettersame(bp, BSTP_INFO_MINE))
1146 		bp->bp_agreed = 0;
1147 
1148 	if (bp->bp_synced && !bp->bp_agreed) {
1149 		bp->bp_synced = 0;
1150 		bs->bs_allsynced = 0;
1151 	}
1152 
1153 	/* copy the designated pv to the port */
1154 	bp->bp_port_pv = bp->bp_desg_pv;
1155 	bp->bp_port_msg_age = bp->bp_desg_msg_age;
1156 	bp->bp_port_max_age = bp->bp_desg_max_age;
1157 	bp->bp_port_fdelay = bp->bp_desg_fdelay;
1158 	bp->bp_port_htime = bp->bp_desg_htime;
1159 	bp->bp_infois = BSTP_INFO_MINE;
1160 
1161 	/* Set transmit flag but do not immediately send */
1162 	bp->bp_flags |= BSTP_PORT_NEWINFO;
1163 }
1164 
1165 /* set tcprop on every port other than the caller */
1166 static void
1167 bstp_set_other_tcprop(struct bstp_port *bp)
1168 {
1169 	struct bstp_state *bs = bp->bp_bs;
1170 	struct bstp_port *bp2;
1171 
1172 	BSTP_LOCK_ASSERT(bs);
1173 
1174 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1175 		if (bp2 == bp)
1176 			continue;
1177 		bp2->bp_tc_prop = 1;
1178 	}
1179 }
1180 
1181 static void
1182 bstp_set_all_reroot(struct bstp_state *bs)
1183 {
1184 	struct bstp_port *bp;
1185 
1186 	BSTP_LOCK_ASSERT(bs);
1187 
1188 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1189 		bp->bp_reroot = 1;
1190 }
1191 
1192 static void
1193 bstp_set_all_sync(struct bstp_state *bs)
1194 {
1195 	struct bstp_port *bp;
1196 
1197 	BSTP_LOCK_ASSERT(bs);
1198 
1199 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1200 		bp->bp_sync = 1;
1201 		bp->bp_synced = 0;	/* Not explicit in spec */
1202 	}
1203 
1204 	bs->bs_allsynced = 0;
1205 }
1206 
1207 static void
1208 bstp_set_port_state(struct bstp_port *bp, int state)
1209 {
1210 	if (bp->bp_state == state)
1211 		return;
1212 
1213 	bp->bp_state = state;
1214 
1215 	switch (bp->bp_state) {
1216 		case BSTP_IFSTATE_DISCARDING:
1217 			DPRINTF("state changed to DISCARDING on %s\n",
1218 			    bp->bp_ifp->if_xname);
1219 			break;
1220 
1221 		case BSTP_IFSTATE_LEARNING:
1222 			DPRINTF("state changed to LEARNING on %s\n",
1223 			    bp->bp_ifp->if_xname);
1224 
1225 			bstp_timer_start(&bp->bp_forward_delay_timer,
1226 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1227 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1228 			break;
1229 
1230 		case BSTP_IFSTATE_FORWARDING:
1231 			DPRINTF("state changed to FORWARDING on %s\n",
1232 			    bp->bp_ifp->if_xname);
1233 
1234 			bstp_timer_stop(&bp->bp_forward_delay_timer);
1235 			/* Record that we enabled forwarding */
1236 			bp->bp_forward_transitions++;
1237 			break;
1238 	}
1239 
1240 	/* notify the parent bridge */
1241 	taskqueue_enqueue(taskqueue_swi, &bp->bp_statetask);
1242 }
1243 
1244 static void
1245 bstp_set_port_role(struct bstp_port *bp, int role)
1246 {
1247 	struct bstp_state *bs = bp->bp_bs;
1248 
1249 	if (bp->bp_role == role)
1250 		return;
1251 
1252 	/* perform pre-change tasks */
1253 	switch (bp->bp_role) {
1254 		case BSTP_ROLE_DISABLED:
1255 			bstp_timer_start(&bp->bp_forward_delay_timer,
1256 			    bp->bp_desg_max_age);
1257 			break;
1258 
1259 		case BSTP_ROLE_BACKUP:
1260 			bstp_timer_start(&bp->bp_recent_backup_timer,
1261 			    bp->bp_desg_htime * 2);
1262 			/* fall through */
1263 		case BSTP_ROLE_ALTERNATE:
1264 			bstp_timer_start(&bp->bp_forward_delay_timer,
1265 			    bp->bp_desg_fdelay);
1266 			bp->bp_sync = 0;
1267 			bp->bp_synced = 1;
1268 			bp->bp_reroot = 0;
1269 			break;
1270 
1271 		case BSTP_ROLE_ROOT:
1272 			bstp_timer_start(&bp->bp_recent_root_timer,
1273 			    BSTP_DEFAULT_FORWARD_DELAY);
1274 			break;
1275 	}
1276 
1277 	bp->bp_role = role;
1278 	/* clear values not carried between roles */
1279 	bp->bp_proposing = 0;
1280 	bs->bs_allsynced = 0;
1281 
1282 	/* initialise the new role */
1283 	switch (bp->bp_role) {
1284 		case BSTP_ROLE_DISABLED:
1285 		case BSTP_ROLE_ALTERNATE:
1286 		case BSTP_ROLE_BACKUP:
1287 			DPRINTF("%s role -> ALT/BACK/DISABLED\n",
1288 			    bp->bp_ifp->if_xname);
1289 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1290 			bstp_timer_stop(&bp->bp_recent_root_timer);
1291 			bstp_timer_latch(&bp->bp_forward_delay_timer);
1292 			bp->bp_sync = 0;
1293 			bp->bp_synced = 1;
1294 			bp->bp_reroot = 0;
1295 			break;
1296 
1297 		case BSTP_ROLE_ROOT:
1298 			DPRINTF("%s role -> ROOT\n",
1299 			    bp->bp_ifp->if_xname);
1300 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1301 			bstp_timer_latch(&bp->bp_recent_root_timer);
1302 			bp->bp_proposing = 0;
1303 			break;
1304 
1305 		case BSTP_ROLE_DESIGNATED:
1306 			DPRINTF("%s role -> DESIGNATED\n",
1307 			    bp->bp_ifp->if_xname);
1308 			bstp_timer_start(&bp->bp_hello_timer,
1309 			    bp->bp_desg_htime);
1310 			bp->bp_agree = 0;
1311 			break;
1312 	}
1313 
1314 	/* let the TC state know that the role changed */
1315 	bstp_update_tc(bp);
1316 }
1317 
1318 static void
1319 bstp_set_port_proto(struct bstp_port *bp, int proto)
1320 {
1321 	struct bstp_state *bs = bp->bp_bs;
1322 
1323 	/* supported protocol versions */
1324 	switch (proto) {
1325 		case BSTP_PROTO_STP:
1326 			/* we can downgrade protocols only */
1327 			bstp_timer_stop(&bp->bp_migrate_delay_timer);
1328 			/* clear unsupported features */
1329 			bp->bp_operedge = 0;
1330 			/* STP compat mode only uses 16 bits of the 32 */
1331 			if (bp->bp_path_cost > 65535)
1332 				bp->bp_path_cost = 65535;
1333 			break;
1334 
1335 		case BSTP_PROTO_RSTP:
1336 			bstp_timer_start(&bp->bp_migrate_delay_timer,
1337 			    bs->bs_migration_delay);
1338 			break;
1339 
1340 		default:
1341 			DPRINTF("Unsupported STP version %d\n", proto);
1342 			return;
1343 	}
1344 
1345 	bp->bp_protover = proto;
1346 	bp->bp_flags &= ~BSTP_PORT_CANMIGRATE;
1347 }
1348 
1349 static void
1350 bstp_set_port_tc(struct bstp_port *bp, int state)
1351 {
1352 	struct bstp_state *bs = bp->bp_bs;
1353 
1354 	bp->bp_tcstate = state;
1355 
1356 	/* initialise the new state */
1357 	switch (bp->bp_tcstate) {
1358 		case BSTP_TCSTATE_ACTIVE:
1359 			DPRINTF("%s -> TC_ACTIVE\n", bp->bp_ifp->if_xname);
1360 			/* nothing to do */
1361 			break;
1362 
1363 		case BSTP_TCSTATE_INACTIVE:
1364 			bstp_timer_stop(&bp->bp_tc_timer);
1365 			/* flush routes on the parent bridge */
1366 			bp->bp_fdbflush = 1;
1367 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1368 			bp->bp_tc_ack = 0;
1369 			DPRINTF("%s -> TC_INACTIVE\n", bp->bp_ifp->if_xname);
1370 			break;
1371 
1372 		case BSTP_TCSTATE_LEARNING:
1373 			bp->bp_rcvdtc = 0;
1374 			bp->bp_rcvdtcn = 0;
1375 			bp->bp_rcvdtca = 0;
1376 			bp->bp_tc_prop = 0;
1377 			DPRINTF("%s -> TC_LEARNING\n", bp->bp_ifp->if_xname);
1378 			break;
1379 
1380 		case BSTP_TCSTATE_DETECTED:
1381 			bstp_set_timer_tc(bp);
1382 			bstp_set_other_tcprop(bp);
1383 			/* send out notification */
1384 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1385 			bstp_transmit(bs, bp);
1386 			getmicrotime(&bs->bs_last_tc_time);
1387 			DPRINTF("%s -> TC_DETECTED\n", bp->bp_ifp->if_xname);
1388 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1389 			break;
1390 
1391 		case BSTP_TCSTATE_TCN:
1392 			bstp_set_timer_tc(bp);
1393 			DPRINTF("%s -> TC_TCN\n", bp->bp_ifp->if_xname);
1394 			/* fall through */
1395 		case BSTP_TCSTATE_TC:
1396 			bp->bp_rcvdtc = 0;
1397 			bp->bp_rcvdtcn = 0;
1398 			if (bp->bp_role == BSTP_ROLE_DESIGNATED)
1399 				bp->bp_tc_ack = 1;
1400 
1401 			bstp_set_other_tcprop(bp);
1402 			DPRINTF("%s -> TC_TC\n", bp->bp_ifp->if_xname);
1403 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1404 			break;
1405 
1406 		case BSTP_TCSTATE_PROPAG:
1407 			/* flush routes on the parent bridge */
1408 			bp->bp_fdbflush = 1;
1409 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1410 			bp->bp_tc_prop = 0;
1411 			bstp_set_timer_tc(bp);
1412 			DPRINTF("%s -> TC_PROPAG\n", bp->bp_ifp->if_xname);
1413 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1414 			break;
1415 
1416 		case BSTP_TCSTATE_ACK:
1417 			bstp_timer_stop(&bp->bp_tc_timer);
1418 			bp->bp_rcvdtca = 0;
1419 			DPRINTF("%s -> TC_ACK\n", bp->bp_ifp->if_xname);
1420 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1421 			break;
1422 	}
1423 }
1424 
1425 static void
1426 bstp_set_timer_tc(struct bstp_port *bp)
1427 {
1428 	struct bstp_state *bs = bp->bp_bs;
1429 
1430 	if (bp->bp_tc_timer.active)
1431 		return;
1432 
1433 	switch (bp->bp_protover) {
1434 		case BSTP_PROTO_RSTP:
1435 			bstp_timer_start(&bp->bp_tc_timer,
1436 			    bp->bp_desg_htime + BSTP_TICK_VAL);
1437 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1438 			break;
1439 
1440 		case BSTP_PROTO_STP:
1441 			bstp_timer_start(&bp->bp_tc_timer,
1442 			    bs->bs_root_max_age + bs->bs_root_fdelay);
1443 			break;
1444 	}
1445 }
1446 
1447 static void
1448 bstp_set_timer_msgage(struct bstp_port *bp)
1449 {
1450 	if (bp->bp_port_msg_age + BSTP_MESSAGE_AGE_INCR <=
1451 	    bp->bp_port_max_age) {
1452 		bstp_timer_start(&bp->bp_message_age_timer,
1453 		    bp->bp_port_htime * 3);
1454 	} else
1455 		/* expires immediately */
1456 		bstp_timer_start(&bp->bp_message_age_timer, 0);
1457 }
1458 
1459 static int
1460 bstp_rerooted(struct bstp_state *bs, struct bstp_port *bp)
1461 {
1462 	struct bstp_port *bp2;
1463 	int rr_set = 0;
1464 
1465 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1466 		if (bp2 == bp)
1467 			continue;
1468 		if (bp2->bp_recent_root_timer.active) {
1469 			rr_set = 1;
1470 			break;
1471 		}
1472 	}
1473 	return (!rr_set);
1474 }
1475 
1476 int
1477 bstp_set_htime(struct bstp_state *bs, int t)
1478 {
1479 	/* convert seconds to ticks */
1480 	t *=  BSTP_TICK_VAL;
1481 
1482 	/* value can only be changed in leagacy stp mode */
1483 	if (bs->bs_protover != BSTP_PROTO_STP)
1484 		return (EPERM);
1485 
1486 	if (t < BSTP_MIN_HELLO_TIME || t > BSTP_MAX_HELLO_TIME)
1487 		return (EINVAL);
1488 
1489 	BSTP_LOCK(bs);
1490 	bs->bs_bridge_htime = t;
1491 	bstp_reinit(bs);
1492 	BSTP_UNLOCK(bs);
1493 	return (0);
1494 }
1495 
1496 int
1497 bstp_set_fdelay(struct bstp_state *bs, int t)
1498 {
1499 	/* convert seconds to ticks */
1500 	t *= BSTP_TICK_VAL;
1501 
1502 	if (t < BSTP_MIN_FORWARD_DELAY || t > BSTP_MAX_FORWARD_DELAY)
1503 		return (EINVAL);
1504 
1505 	BSTP_LOCK(bs);
1506 	bs->bs_bridge_fdelay = t;
1507 	bstp_reinit(bs);
1508 	BSTP_UNLOCK(bs);
1509 	return (0);
1510 }
1511 
1512 int
1513 bstp_set_maxage(struct bstp_state *bs, int t)
1514 {
1515 	/* convert seconds to ticks */
1516 	t *= BSTP_TICK_VAL;
1517 
1518 	if (t < BSTP_MIN_MAX_AGE || t > BSTP_MAX_MAX_AGE)
1519 		return (EINVAL);
1520 
1521 	BSTP_LOCK(bs);
1522 	bs->bs_bridge_max_age = t;
1523 	bstp_reinit(bs);
1524 	BSTP_UNLOCK(bs);
1525 	return (0);
1526 }
1527 
1528 int
1529 bstp_set_holdcount(struct bstp_state *bs, int count)
1530 {
1531 	struct bstp_port *bp;
1532 
1533 	if (count < BSTP_MIN_HOLD_COUNT ||
1534 	    count > BSTP_MAX_HOLD_COUNT)
1535 		return (EINVAL);
1536 
1537 	BSTP_LOCK(bs);
1538 	bs->bs_txholdcount = count;
1539 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1540 		bp->bp_txcount = 0;
1541 	BSTP_UNLOCK(bs);
1542 	return (0);
1543 }
1544 
1545 int
1546 bstp_set_protocol(struct bstp_state *bs, int proto)
1547 {
1548 	struct bstp_port *bp;
1549 
1550 	switch (proto) {
1551 		/* Supported protocol versions */
1552 		case BSTP_PROTO_STP:
1553 		case BSTP_PROTO_RSTP:
1554 			break;
1555 
1556 		default:
1557 			return (EINVAL);
1558 	}
1559 
1560 	BSTP_LOCK(bs);
1561 	bs->bs_protover = proto;
1562 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
1563 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1564 		/* reinit state */
1565 		bp->bp_infois = BSTP_INFO_DISABLED;
1566 		bp->bp_txcount = 0;
1567 		bstp_set_port_proto(bp, bs->bs_protover);
1568 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
1569 		bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1570 		bstp_timer_stop(&bp->bp_recent_backup_timer);
1571 	}
1572 	bstp_reinit(bs);
1573 	BSTP_UNLOCK(bs);
1574 	return (0);
1575 }
1576 
1577 int
1578 bstp_set_priority(struct bstp_state *bs, int pri)
1579 {
1580 	if (pri < 0 || pri > BSTP_MAX_PRIORITY)
1581 		return (EINVAL);
1582 
1583 	/* Limit to steps of 4096 */
1584 	pri -= pri % 4096;
1585 
1586 	BSTP_LOCK(bs);
1587 	bs->bs_bridge_priority = pri;
1588 	bstp_reinit(bs);
1589 	BSTP_UNLOCK(bs);
1590 	return (0);
1591 }
1592 
1593 int
1594 bstp_set_port_priority(struct bstp_port *bp, int pri)
1595 {
1596 	struct bstp_state *bs = bp->bp_bs;
1597 
1598 	if (pri < 0 || pri > BSTP_MAX_PORT_PRIORITY)
1599 		return (EINVAL);
1600 
1601 	/* Limit to steps of 16 */
1602 	pri -= pri % 16;
1603 
1604 	BSTP_LOCK(bs);
1605 	bp->bp_priority = pri;
1606 	bstp_reinit(bs);
1607 	BSTP_UNLOCK(bs);
1608 	return (0);
1609 }
1610 
1611 int
1612 bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
1613 {
1614 	struct bstp_state *bs = bp->bp_bs;
1615 
1616 	if (path_cost > BSTP_MAX_PATH_COST)
1617 		return (EINVAL);
1618 
1619 	/* STP compat mode only uses 16 bits of the 32 */
1620 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1621 		path_cost = 65535;
1622 
1623 	BSTP_LOCK(bs);
1624 
1625 	if (path_cost == 0) {	/* use auto */
1626 		bp->bp_flags &= ~BSTP_PORT_ADMCOST;
1627 		bp->bp_path_cost = bstp_calc_path_cost(bp);
1628 	} else {
1629 		bp->bp_path_cost = path_cost;
1630 		bp->bp_flags |= BSTP_PORT_ADMCOST;
1631 	}
1632 	bstp_reinit(bs);
1633 	BSTP_UNLOCK(bs);
1634 	return (0);
1635 }
1636 
1637 int
1638 bstp_set_edge(struct bstp_port *bp, int set)
1639 {
1640 	struct bstp_state *bs = bp->bp_bs;
1641 
1642 	BSTP_LOCK(bs);
1643 	if ((bp->bp_operedge = set) == 0)
1644 		bp->bp_flags &= ~BSTP_PORT_ADMEDGE;
1645 	else
1646 		bp->bp_flags |= BSTP_PORT_ADMEDGE;
1647 	BSTP_UNLOCK(bs);
1648 	return (0);
1649 }
1650 
1651 int
1652 bstp_set_autoedge(struct bstp_port *bp, int set)
1653 {
1654 	struct bstp_state *bs = bp->bp_bs;
1655 
1656 	BSTP_LOCK(bs);
1657 	if (set) {
1658 		bp->bp_flags |= BSTP_PORT_AUTOEDGE;
1659 		/* we may be able to transition straight to edge */
1660 		if (bp->bp_edge_delay_timer.active == 0)
1661 			bstp_edge_delay_expiry(bs, bp);
1662 	} else
1663 		bp->bp_flags &= ~BSTP_PORT_AUTOEDGE;
1664 	BSTP_UNLOCK(bs);
1665 	return (0);
1666 }
1667 
1668 int
1669 bstp_set_ptp(struct bstp_port *bp, int set)
1670 {
1671 	struct bstp_state *bs = bp->bp_bs;
1672 
1673 	BSTP_LOCK(bs);
1674 	bp->bp_ptp_link = set;
1675 	BSTP_UNLOCK(bs);
1676 	return (0);
1677 }
1678 
1679 int
1680 bstp_set_autoptp(struct bstp_port *bp, int set)
1681 {
1682 	struct bstp_state *bs = bp->bp_bs;
1683 
1684 	BSTP_LOCK(bs);
1685 	if (set) {
1686 		bp->bp_flags |= BSTP_PORT_AUTOPTP;
1687 		if (bp->bp_role != BSTP_ROLE_DISABLED)
1688 			taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
1689 	} else
1690 		bp->bp_flags &= ~BSTP_PORT_AUTOPTP;
1691 	BSTP_UNLOCK(bs);
1692 	return (0);
1693 }
1694 
1695 /*
1696  * Calculate the path cost according to the link speed.
1697  */
1698 static uint32_t
1699 bstp_calc_path_cost(struct bstp_port *bp)
1700 {
1701 	struct ifnet *ifp = bp->bp_ifp;
1702 	uint32_t path_cost;
1703 
1704 	/* If the priority has been manually set then retain the value */
1705 	if (bp->bp_flags & BSTP_PORT_ADMCOST)
1706 		return bp->bp_path_cost;
1707 
1708 	if (ifp->if_link_state == LINK_STATE_DOWN) {
1709 		/* Recalc when the link comes up again */
1710 		bp->bp_flags |= BSTP_PORT_PNDCOST;
1711 		return (BSTP_DEFAULT_PATH_COST);
1712 	}
1713 
1714 	if (ifp->if_baudrate < 1000)
1715 		return (BSTP_DEFAULT_PATH_COST);
1716 
1717  	/* formula from section 17.14, IEEE Std 802.1D-2004 */
1718 	path_cost = 20000000000ULL / (ifp->if_baudrate / 1000);
1719 
1720 	if (path_cost > BSTP_MAX_PATH_COST)
1721 		path_cost = BSTP_MAX_PATH_COST;
1722 
1723 	/* STP compat mode only uses 16 bits of the 32 */
1724 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1725 		path_cost = 65535;
1726 
1727 	return (path_cost);
1728 }
1729 
1730 /*
1731  * Notify the bridge that a port state has changed, we need to do this from a
1732  * taskqueue to avoid a LOR.
1733  */
1734 static void
1735 bstp_notify_state(void *arg, int pending)
1736 {
1737 	struct bstp_port *bp = (struct bstp_port *)arg;
1738 	struct bstp_state *bs = bp->bp_bs;
1739 
1740 	if (bp->bp_active == 1 && bs->bs_state_cb != NULL)
1741 		(*bs->bs_state_cb)(bp->bp_ifp, bp->bp_state);
1742 }
1743 
1744 /*
1745  * Flush the routes on the bridge port, we need to do this from a
1746  * taskqueue to avoid a LOR.
1747  */
1748 static void
1749 bstp_notify_rtage(void *arg, int pending)
1750 {
1751 	struct bstp_port *bp = (struct bstp_port *)arg;
1752 	struct bstp_state *bs = bp->bp_bs;
1753 	int age = 0;
1754 
1755 	BSTP_LOCK(bs);
1756 	switch (bp->bp_protover) {
1757 		case BSTP_PROTO_STP:
1758 			/* convert to seconds */
1759 			age = bp->bp_desg_fdelay / BSTP_TICK_VAL;
1760 			break;
1761 
1762 		case BSTP_PROTO_RSTP:
1763 			age = 0;
1764 			break;
1765 	}
1766 	BSTP_UNLOCK(bs);
1767 
1768 	if (bp->bp_active == 1 && bs->bs_rtage_cb != NULL)
1769 		(*bs->bs_rtage_cb)(bp->bp_ifp, age);
1770 
1771 	/* flush is complete */
1772 	BSTP_LOCK(bs);
1773 	bp->bp_fdbflush = 0;
1774 	BSTP_UNLOCK(bs);
1775 }
1776 
1777 void
1778 bstp_linkstate(struct bstp_port *bp)
1779 {
1780 	struct bstp_state *bs = bp->bp_bs;
1781 
1782 	if (!bp->bp_active)
1783 		return;
1784 
1785 	bstp_ifupdstatus(bp, 0);
1786 	BSTP_LOCK(bs);
1787 	bstp_update_state(bs, bp);
1788 	BSTP_UNLOCK(bs);
1789 }
1790 
1791 static void
1792 bstp_ifupdstatus(void *arg, int pending)
1793 {
1794 	struct bstp_port *bp = (struct bstp_port *)arg;
1795 	struct bstp_state *bs = bp->bp_bs;
1796 	struct ifnet *ifp = bp->bp_ifp;
1797 	struct ifmediareq ifmr;
1798 	int error, changed;
1799 
1800 	if (!bp->bp_active)
1801 		return;
1802 
1803 	bzero((char *)&ifmr, sizeof(ifmr));
1804 	error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);
1805 
1806 	BSTP_LOCK(bs);
1807 	changed = 0;
1808 	if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1809 		if (ifmr.ifm_status & IFM_ACTIVE) {
1810 			/* A full-duplex link is assumed to be point to point */
1811 			if (bp->bp_flags & BSTP_PORT_AUTOPTP) {
1812 				int fdx;
1813 
1814 				fdx = ifmr.ifm_active & IFM_FDX ? 1 : 0;
1815 				if (bp->bp_ptp_link ^ fdx) {
1816 					bp->bp_ptp_link = fdx;
1817 					changed = 1;
1818 				}
1819 			}
1820 
1821 			/* Calc the cost if the link was down previously */
1822 			if (bp->bp_flags & BSTP_PORT_PNDCOST) {
1823 				uint32_t cost;
1824 
1825 				cost = bstp_calc_path_cost(bp);
1826 				if (bp->bp_path_cost != cost) {
1827 					bp->bp_path_cost = cost;
1828 					changed = 1;
1829 				}
1830 				bp->bp_flags &= ~BSTP_PORT_PNDCOST;
1831 			}
1832 
1833 			if (bp->bp_role == BSTP_ROLE_DISABLED) {
1834 				bstp_enable_port(bs, bp);
1835 				changed = 1;
1836 			}
1837 		} else {
1838 			if (bp->bp_role != BSTP_ROLE_DISABLED) {
1839 				bstp_disable_port(bs, bp);
1840 				changed = 1;
1841 				if ((bp->bp_flags & BSTP_PORT_ADMEDGE) &&
1842 				    bp->bp_protover == BSTP_PROTO_RSTP)
1843 					bp->bp_operedge = 1;
1844 			}
1845 		}
1846 	} else if (bp->bp_infois != BSTP_INFO_DISABLED) {
1847 		bstp_disable_port(bs, bp);
1848 		changed = 1;
1849 	}
1850 	if (changed)
1851 		bstp_assign_roles(bs);
1852 	BSTP_UNLOCK(bs);
1853 }
1854 
1855 static void
1856 bstp_enable_port(struct bstp_state *bs, struct bstp_port *bp)
1857 {
1858 	bp->bp_infois = BSTP_INFO_AGED;
1859 }
1860 
1861 static void
1862 bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
1863 {
1864 	bp->bp_infois = BSTP_INFO_DISABLED;
1865 }
1866 
1867 static void
1868 bstp_tick(void *arg)
1869 {
1870 	struct epoch_tracker et;
1871 	struct bstp_state *bs = arg;
1872 	struct bstp_port *bp;
1873 
1874 	BSTP_LOCK_ASSERT(bs);
1875 
1876 	if (bs->bs_running == 0)
1877 		return;
1878 
1879 	NET_EPOCH_ENTER(et);
1880 	CURVNET_SET(bs->bs_vnet);
1881 
1882 	/* poll link events on interfaces that do not support linkstate */
1883 	if (bstp_timer_dectest(&bs->bs_link_timer)) {
1884 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1885 			if (!(bp->bp_ifp->if_capabilities & IFCAP_LINKSTATE))
1886 				taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
1887 		}
1888 		bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
1889 	}
1890 
1891 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1892 		/* no events need to happen for these */
1893 		bstp_timer_dectest(&bp->bp_tc_timer);
1894 		bstp_timer_dectest(&bp->bp_recent_root_timer);
1895 		bstp_timer_dectest(&bp->bp_forward_delay_timer);
1896 		bstp_timer_dectest(&bp->bp_recent_backup_timer);
1897 
1898 		if (bstp_timer_dectest(&bp->bp_hello_timer))
1899 			bstp_hello_timer_expiry(bs, bp);
1900 
1901 		if (bstp_timer_dectest(&bp->bp_message_age_timer))
1902 			bstp_message_age_expiry(bs, bp);
1903 
1904 		if (bstp_timer_dectest(&bp->bp_migrate_delay_timer))
1905 			bstp_migrate_delay_expiry(bs, bp);
1906 
1907 		if (bstp_timer_dectest(&bp->bp_edge_delay_timer))
1908 			bstp_edge_delay_expiry(bs, bp);
1909 
1910 		/* update the various state machines for the port */
1911 		bstp_update_state(bs, bp);
1912 
1913 		if (bp->bp_txcount > 0)
1914 			bp->bp_txcount--;
1915 	}
1916 
1917 	CURVNET_RESTORE();
1918 	NET_EPOCH_EXIT(et);
1919 
1920 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
1921 }
1922 
1923 static void
1924 bstp_timer_start(struct bstp_timer *t, uint16_t v)
1925 {
1926 	t->value = v;
1927 	t->active = 1;
1928 	t->latched = 0;
1929 }
1930 
1931 static void
1932 bstp_timer_stop(struct bstp_timer *t)
1933 {
1934 	t->value = 0;
1935 	t->active = 0;
1936 	t->latched = 0;
1937 }
1938 
1939 static void
1940 bstp_timer_latch(struct bstp_timer *t)
1941 {
1942 	t->latched = 1;
1943 	t->active = 1;
1944 }
1945 
1946 static int
1947 bstp_timer_dectest(struct bstp_timer *t)
1948 {
1949 	if (t->active == 0 || t->latched)
1950 		return (0);
1951 	t->value -= BSTP_TICK_VAL;
1952 	if (t->value <= 0) {
1953 		bstp_timer_stop(t);
1954 		return (1);
1955 	}
1956 	return (0);
1957 }
1958 
1959 static void
1960 bstp_hello_timer_expiry(struct bstp_state *bs, struct bstp_port *bp)
1961 {
1962 	if ((bp->bp_flags & BSTP_PORT_NEWINFO) ||
1963 	    bp->bp_role == BSTP_ROLE_DESIGNATED ||
1964 	    (bp->bp_role == BSTP_ROLE_ROOT &&
1965 	     bp->bp_tc_timer.active == 1)) {
1966 		bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
1967 		bp->bp_flags |= BSTP_PORT_NEWINFO;
1968 		bstp_transmit(bs, bp);
1969 	}
1970 }
1971 
1972 static void
1973 bstp_message_age_expiry(struct bstp_state *bs, struct bstp_port *bp)
1974 {
1975 	if (bp->bp_infois == BSTP_INFO_RECEIVED) {
1976 		bp->bp_infois = BSTP_INFO_AGED;
1977 		bstp_assign_roles(bs);
1978 		DPRINTF("aged info on %s\n", bp->bp_ifp->if_xname);
1979 	}
1980 }
1981 
1982 static void
1983 bstp_migrate_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1984 {
1985 	bp->bp_flags |= BSTP_PORT_CANMIGRATE;
1986 }
1987 
1988 static void
1989 bstp_edge_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1990 {
1991 	if ((bp->bp_flags & BSTP_PORT_AUTOEDGE) &&
1992 	    bp->bp_protover == BSTP_PROTO_RSTP && bp->bp_proposing &&
1993 	    bp->bp_role == BSTP_ROLE_DESIGNATED) {
1994 		bp->bp_operedge = 1;
1995 		DPRINTF("%s -> edge port\n", bp->bp_ifp->if_xname);
1996 	}
1997 }
1998 
1999 static int
2000 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
2001 {
2002 	int i, d;
2003 
2004 	for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
2005 		d = ((int)a[i]) - ((int)b[i]);
2006 	}
2007 
2008 	return (d);
2009 }
2010 
2011 /*
2012  * compare the bridge address component of the bridgeid
2013  */
2014 static int
2015 bstp_same_bridgeid(uint64_t id1, uint64_t id2)
2016 {
2017 	u_char addr1[ETHER_ADDR_LEN];
2018 	u_char addr2[ETHER_ADDR_LEN];
2019 
2020 	PV2ADDR(id1, addr1);
2021 	PV2ADDR(id2, addr2);
2022 
2023 	if (bstp_addr_cmp(addr1, addr2) == 0)
2024 		return (1);
2025 
2026 	return (0);
2027 }
2028 
2029 void
2030 bstp_reinit(struct bstp_state *bs)
2031 {
2032 	struct epoch_tracker et;
2033 	struct bstp_port *bp;
2034 	struct ifnet *ifp, *mif;
2035 	u_char *e_addr;
2036 	void *bridgeptr;
2037 	static const u_char llzero[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */
2038 
2039 	BSTP_LOCK_ASSERT(bs);
2040 
2041 	if (LIST_EMPTY(&bs->bs_bplist))
2042 		goto disablestp;
2043 
2044 	mif = NULL;
2045 	bridgeptr = LIST_FIRST(&bs->bs_bplist)->bp_ifp->if_bridge;
2046 	KASSERT(bridgeptr != NULL, ("Invalid bridge pointer"));
2047 	/*
2048 	 * Search through the Ethernet adapters and find the one with the
2049 	 * lowest value. Make sure the adapter which we take the MAC address
2050 	 * from is part of this bridge, so we can have more than one independent
2051 	 * bridges in the same STP domain.
2052 	 */
2053 	NET_EPOCH_ENTER(et);
2054 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2055 		if (ifp->if_type != IFT_ETHER && ifp->if_type != IFT_L2VLAN)
2056 			continue;	/* Not Ethernet */
2057 
2058 		if (ifp->if_bridge != bridgeptr)
2059 			continue;	/* Not part of our bridge */
2060 
2061 		if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
2062 			continue;	/* No mac address set */
2063 
2064 		if (mif == NULL) {
2065 			mif = ifp;
2066 			continue;
2067 		}
2068 		if (bstp_addr_cmp(IF_LLADDR(ifp), IF_LLADDR(mif)) < 0) {
2069 			mif = ifp;
2070 			continue;
2071 		}
2072 	}
2073 	NET_EPOCH_EXIT(et);
2074 	if (mif == NULL)
2075 		goto disablestp;
2076 
2077 	e_addr = IF_LLADDR(mif);
2078 	bs->bs_bridge_pv.pv_dbridge_id =
2079 	    (((uint64_t)bs->bs_bridge_priority) << 48) |
2080 	    (((uint64_t)e_addr[0]) << 40) |
2081 	    (((uint64_t)e_addr[1]) << 32) |
2082 	    (((uint64_t)e_addr[2]) << 24) |
2083 	    (((uint64_t)e_addr[3]) << 16) |
2084 	    (((uint64_t)e_addr[4]) << 8) |
2085 	    (((uint64_t)e_addr[5]));
2086 
2087 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2088 	bs->bs_bridge_pv.pv_cost = 0;
2089 	bs->bs_bridge_pv.pv_dport_id = 0;
2090 	bs->bs_bridge_pv.pv_port_id = 0;
2091 
2092 	if (bs->bs_running && callout_pending(&bs->bs_bstpcallout) == 0)
2093 		callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2094 
2095 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2096 		bp->bp_port_id = (bp->bp_priority << 8) |
2097 		    (bp->bp_ifp->if_index  & 0xfff);
2098 		taskqueue_enqueue(taskqueue_swi, &bp->bp_mediatask);
2099 	}
2100 
2101 	bstp_assign_roles(bs);
2102 	bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
2103 	return;
2104 
2105 disablestp:
2106 	/* Set the bridge and root id (lower bits) to zero */
2107 	bs->bs_bridge_pv.pv_dbridge_id =
2108 	    ((uint64_t)bs->bs_bridge_priority) << 48;
2109 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2110 	bs->bs_root_pv = bs->bs_bridge_pv;
2111 	/* Disable any remaining ports, they will have no MAC address */
2112 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2113 		bp->bp_infois = BSTP_INFO_DISABLED;
2114 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2115 	}
2116 	callout_stop(&bs->bs_bstpcallout);
2117 }
2118 
2119 static int
2120 bstp_modevent(module_t mod, int type, void *data)
2121 {
2122 	switch (type) {
2123 	case MOD_LOAD:
2124 		mtx_init(&bstp_list_mtx, "bridgestp list", NULL, MTX_DEF);
2125 		LIST_INIT(&bstp_list);
2126 		break;
2127 	case MOD_UNLOAD:
2128 		mtx_destroy(&bstp_list_mtx);
2129 		break;
2130 	default:
2131 		return (EOPNOTSUPP);
2132 	}
2133 	return (0);
2134 }
2135 
2136 static moduledata_t bstp_mod = {
2137 	"bridgestp",
2138 	bstp_modevent,
2139 	0
2140 };
2141 
2142 DECLARE_MODULE(bridgestp, bstp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2143 MODULE_VERSION(bridgestp, 1);
2144 
2145 void
2146 bstp_attach(struct bstp_state *bs, struct bstp_cb_ops *cb)
2147 {
2148 	BSTP_LOCK_INIT(bs);
2149 	callout_init_mtx(&bs->bs_bstpcallout, &bs->bs_mtx, 0);
2150 	LIST_INIT(&bs->bs_bplist);
2151 
2152 	bs->bs_bridge_max_age = BSTP_DEFAULT_MAX_AGE;
2153 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
2154 	bs->bs_bridge_fdelay = BSTP_DEFAULT_FORWARD_DELAY;
2155 	bs->bs_bridge_priority = BSTP_DEFAULT_BRIDGE_PRIORITY;
2156 	bs->bs_hold_time = BSTP_DEFAULT_HOLD_TIME;
2157 	bs->bs_migration_delay = BSTP_DEFAULT_MIGRATE_DELAY;
2158 	bs->bs_txholdcount = BSTP_DEFAULT_HOLD_COUNT;
2159 	bs->bs_protover = BSTP_PROTO_RSTP;
2160 	bs->bs_state_cb = cb->bcb_state;
2161 	bs->bs_rtage_cb = cb->bcb_rtage;
2162 	bs->bs_vnet = curvnet;
2163 
2164 	getmicrotime(&bs->bs_last_tc_time);
2165 
2166 	mtx_lock(&bstp_list_mtx);
2167 	LIST_INSERT_HEAD(&bstp_list, bs, bs_list);
2168 	mtx_unlock(&bstp_list_mtx);
2169 }
2170 
2171 void
2172 bstp_detach(struct bstp_state *bs)
2173 {
2174 	KASSERT(LIST_EMPTY(&bs->bs_bplist), ("bstp still active"));
2175 
2176 	mtx_lock(&bstp_list_mtx);
2177 	LIST_REMOVE(bs, bs_list);
2178 	mtx_unlock(&bstp_list_mtx);
2179 	callout_drain(&bs->bs_bstpcallout);
2180 	BSTP_LOCK_DESTROY(bs);
2181 }
2182 
2183 void
2184 bstp_init(struct bstp_state *bs)
2185 {
2186 	BSTP_LOCK(bs);
2187 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2188 	bs->bs_running = 1;
2189 	bstp_reinit(bs);
2190 	BSTP_UNLOCK(bs);
2191 }
2192 
2193 void
2194 bstp_stop(struct bstp_state *bs)
2195 {
2196 	struct bstp_port *bp;
2197 
2198 	BSTP_LOCK(bs);
2199 
2200 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
2201 		bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2202 
2203 	bs->bs_running = 0;
2204 	callout_stop(&bs->bs_bstpcallout);
2205 	BSTP_UNLOCK(bs);
2206 }
2207 
2208 int
2209 bstp_create(struct bstp_state *bs, struct bstp_port *bp, struct ifnet *ifp)
2210 {
2211 	bzero(bp, sizeof(struct bstp_port));
2212 
2213 	BSTP_LOCK(bs);
2214 	bp->bp_ifp = ifp;
2215 	bp->bp_bs = bs;
2216 	bp->bp_priority = BSTP_DEFAULT_PORT_PRIORITY;
2217 	TASK_INIT(&bp->bp_statetask, 0, bstp_notify_state, bp);
2218 	TASK_INIT(&bp->bp_rtagetask, 0, bstp_notify_rtage, bp);
2219 	TASK_INIT(&bp->bp_mediatask, 0, bstp_ifupdstatus, bp);
2220 
2221 	/* Init state */
2222 	bp->bp_infois = BSTP_INFO_DISABLED;
2223 	bp->bp_flags = BSTP_PORT_AUTOEDGE|BSTP_PORT_AUTOPTP;
2224 	bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2225 	bstp_set_port_proto(bp, bs->bs_protover);
2226 	bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2227 	bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
2228 	bp->bp_path_cost = bstp_calc_path_cost(bp);
2229 	BSTP_UNLOCK(bs);
2230 	return (0);
2231 }
2232 
2233 int
2234 bstp_enable(struct bstp_port *bp)
2235 {
2236 	struct bstp_state *bs = bp->bp_bs;
2237 	struct ifnet *ifp = bp->bp_ifp;
2238 
2239 	KASSERT(bp->bp_active == 0, ("already a bstp member"));
2240 	NET_EPOCH_ASSERT(); /* Because bstp_update_roles() causes traffic. */
2241 
2242 	switch (ifp->if_type) {
2243 		case IFT_ETHER:	/* These can do spanning tree. */
2244 		case IFT_L2VLAN:
2245 			break;
2246 		default:
2247 			/* Nothing else can. */
2248 			return (EINVAL);
2249 	}
2250 
2251 	BSTP_LOCK(bs);
2252 	LIST_INSERT_HEAD(&bs->bs_bplist, bp, bp_next);
2253 	bp->bp_active = 1;
2254 	bp->bp_flags |= BSTP_PORT_NEWINFO;
2255 	bstp_reinit(bs);
2256 	bstp_update_roles(bs, bp);
2257 	BSTP_UNLOCK(bs);
2258 	return (0);
2259 }
2260 
2261 void
2262 bstp_disable(struct bstp_port *bp)
2263 {
2264 	struct bstp_state *bs = bp->bp_bs;
2265 
2266 	KASSERT(bp->bp_active == 1, ("not a bstp member"));
2267 
2268 	BSTP_LOCK(bs);
2269 	bstp_disable_port(bs, bp);
2270 	LIST_REMOVE(bp, bp_next);
2271 	bp->bp_active = 0;
2272 	bstp_reinit(bs);
2273 	BSTP_UNLOCK(bs);
2274 }
2275 
2276 /*
2277  * The bstp_port structure is about to be freed by the parent bridge.
2278  */
2279 void
2280 bstp_destroy(struct bstp_port *bp)
2281 {
2282 	KASSERT(bp->bp_active == 0, ("port is still attached"));
2283 	taskqueue_drain(taskqueue_swi, &bp->bp_statetask);
2284 	taskqueue_drain(taskqueue_swi, &bp->bp_rtagetask);
2285 	taskqueue_drain(taskqueue_swi, &bp->bp_mediatask);
2286 
2287 	if (bp->bp_bs->bs_root_port == bp)
2288 		bstp_assign_roles(bp->bp_bs);
2289 }
2290