xref: /freebsd/sys/net/bridgestp.c (revision a9148abd9da5db2f1c682fb17bed791845fc41c9)
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/callout.h>
47 #include <sys/module.h>
48 #include <sys/proc.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/taskqueue.h>
52 #include <sys/vimage.h>
53 
54 #include <net/if.h>
55 #include <net/if_dl.h>
56 #include <net/if_types.h>
57 #include <net/if_llc.h>
58 #include <net/if_media.h>
59 
60 #include <netinet/in.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/in_var.h>
63 #include <netinet/if_ether.h>
64 #include <net/bridgestp.h>
65 
66 #ifdef	BRIDGESTP_DEBUG
67 #define	DPRINTF(fmt, arg...)	printf("bstp: " fmt, ##arg)
68 #else
69 #define	DPRINTF(fmt, arg...)
70 #endif
71 
72 #define	PV2ADDR(pv, eaddr)	do {		\
73 	eaddr[0] = pv >> 40;			\
74 	eaddr[1] = pv >> 32;			\
75 	eaddr[2] = pv >> 24;			\
76 	eaddr[3] = pv >> 16;			\
77 	eaddr[4] = pv >> 8;			\
78 	eaddr[5] = pv >> 0;			\
79 } while (0)
80 
81 #define	INFO_BETTER	1
82 #define	INFO_SAME	0
83 #define	INFO_WORSE	-1
84 
85 const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
86 
87 LIST_HEAD(, bstp_state) bstp_list;
88 static struct mtx	bstp_list_mtx;
89 
90 static void	bstp_transmit(struct bstp_state *, struct bstp_port *);
91 static void	bstp_transmit_bpdu(struct bstp_state *, struct bstp_port *);
92 static void	bstp_transmit_tcn(struct bstp_state *, struct bstp_port *);
93 static void	bstp_decode_bpdu(struct bstp_port *, struct bstp_cbpdu *,
94 		    struct bstp_config_unit *);
95 static void	bstp_send_bpdu(struct bstp_state *, struct bstp_port *,
96 		    struct bstp_cbpdu *);
97 static void	bstp_enqueue(struct ifnet *, struct mbuf *);
98 static int	bstp_pdu_flags(struct bstp_port *);
99 static void	bstp_received_stp(struct bstp_state *, struct bstp_port *,
100 		    struct mbuf **, struct bstp_tbpdu *);
101 static void	bstp_received_rstp(struct bstp_state *, struct bstp_port *,
102 		    struct mbuf **, struct bstp_tbpdu *);
103 static void	bstp_received_tcn(struct bstp_state *, struct bstp_port *,
104 		    struct bstp_tcn_unit *);
105 static void	bstp_received_bpdu(struct bstp_state *, struct bstp_port *,
106 		    struct bstp_config_unit *);
107 static int	bstp_pdu_rcvtype(struct bstp_port *, struct bstp_config_unit *);
108 static int	bstp_pdu_bettersame(struct bstp_port *, int);
109 static int	bstp_info_cmp(struct bstp_pri_vector *,
110 		    struct bstp_pri_vector *);
111 static int	bstp_info_superior(struct bstp_pri_vector *,
112 		    struct bstp_pri_vector *);
113 static void	bstp_assign_roles(struct bstp_state *);
114 static void	bstp_update_roles(struct bstp_state *, struct bstp_port *);
115 static void	bstp_update_state(struct bstp_state *, struct bstp_port *);
116 static void	bstp_update_tc(struct bstp_port *);
117 static void	bstp_update_info(struct bstp_port *);
118 static void	bstp_set_other_tcprop(struct bstp_port *);
119 static void	bstp_set_all_reroot(struct bstp_state *);
120 static void	bstp_set_all_sync(struct bstp_state *);
121 static void	bstp_set_port_state(struct bstp_port *, int);
122 static void	bstp_set_port_role(struct bstp_port *, int);
123 static void	bstp_set_port_proto(struct bstp_port *, int);
124 static void	bstp_set_port_tc(struct bstp_port *, int);
125 static void	bstp_set_timer_tc(struct bstp_port *);
126 static void	bstp_set_timer_msgage(struct bstp_port *);
127 static int	bstp_rerooted(struct bstp_state *, struct bstp_port *);
128 static uint32_t	bstp_calc_path_cost(struct bstp_port *);
129 static void	bstp_notify_state(void *, int);
130 static void	bstp_notify_rtage(void *, int);
131 static void	bstp_ifupdstatus(struct bstp_state *, struct bstp_port *);
132 static void	bstp_enable_port(struct bstp_state *, struct bstp_port *);
133 static void	bstp_disable_port(struct bstp_state *, struct bstp_port *);
134 static void	bstp_tick(void *);
135 static void	bstp_timer_start(struct bstp_timer *, uint16_t);
136 static void	bstp_timer_stop(struct bstp_timer *);
137 static void	bstp_timer_latch(struct bstp_timer *);
138 static int	bstp_timer_expired(struct bstp_timer *);
139 static void	bstp_hello_timer_expiry(struct bstp_state *,
140 		    struct bstp_port *);
141 static void	bstp_message_age_expiry(struct bstp_state *,
142 		    struct bstp_port *);
143 static void	bstp_migrate_delay_expiry(struct bstp_state *,
144 		    struct bstp_port *);
145 static void	bstp_edge_delay_expiry(struct bstp_state *,
146 		    struct bstp_port *);
147 static int	bstp_addr_cmp(const uint8_t *, const uint8_t *);
148 static int	bstp_same_bridgeid(uint64_t, uint64_t);
149 static void	bstp_reinit(struct bstp_state *);
150 
151 static void
152 bstp_transmit(struct bstp_state *bs, struct bstp_port *bp)
153 {
154 	if (bs->bs_running == 0)
155 		return;
156 
157 	/*
158 	 * a PDU can only be sent if we have tx quota left and the
159 	 * hello timer is running.
160 	 */
161 	if (bp->bp_hello_timer.active == 0) {
162 		/* Test if it needs to be reset */
163 		bstp_hello_timer_expiry(bs, bp);
164 		return;
165 	}
166 	if (bp->bp_txcount > bs->bs_txholdcount)
167 		/* Ran out of karma */
168 		return;
169 
170 	if (bp->bp_protover == BSTP_PROTO_RSTP) {
171 		bstp_transmit_bpdu(bs, bp);
172 		bp->bp_tc_ack = 0;
173 	} else { /* STP */
174 		switch (bp->bp_role) {
175 			case BSTP_ROLE_DESIGNATED:
176 				bstp_transmit_bpdu(bs, bp);
177 				bp->bp_tc_ack = 0;
178 				break;
179 
180 			case BSTP_ROLE_ROOT:
181 				bstp_transmit_tcn(bs, bp);
182 				break;
183 		}
184 	}
185 	bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
186 	bp->bp_flags &= ~BSTP_PORT_NEWINFO;
187 }
188 
189 static void
190 bstp_transmit_bpdu(struct bstp_state *bs, struct bstp_port *bp)
191 {
192 	struct bstp_cbpdu bpdu;
193 
194 	BSTP_LOCK_ASSERT(bs);
195 
196 	bpdu.cbu_rootpri = htons(bp->bp_desg_pv.pv_root_id >> 48);
197 	PV2ADDR(bp->bp_desg_pv.pv_root_id, bpdu.cbu_rootaddr);
198 
199 	bpdu.cbu_rootpathcost = htonl(bp->bp_desg_pv.pv_cost);
200 
201 	bpdu.cbu_bridgepri = htons(bp->bp_desg_pv.pv_dbridge_id >> 48);
202 	PV2ADDR(bp->bp_desg_pv.pv_dbridge_id, bpdu.cbu_bridgeaddr);
203 
204 	bpdu.cbu_portid = htons(bp->bp_port_id);
205 	bpdu.cbu_messageage = htons(bp->bp_desg_msg_age);
206 	bpdu.cbu_maxage = htons(bp->bp_desg_max_age);
207 	bpdu.cbu_hellotime = htons(bp->bp_desg_htime);
208 	bpdu.cbu_forwarddelay = htons(bp->bp_desg_fdelay);
209 
210 	bpdu.cbu_flags = bstp_pdu_flags(bp);
211 
212 	switch (bp->bp_protover) {
213 		case BSTP_PROTO_STP:
214 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_CFG;
215 			break;
216 
217 		case BSTP_PROTO_RSTP:
218 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_RSTP;
219 			break;
220 	}
221 
222 	bstp_send_bpdu(bs, bp, &bpdu);
223 }
224 
225 static void
226 bstp_transmit_tcn(struct bstp_state *bs, struct bstp_port *bp)
227 {
228 	struct bstp_tbpdu bpdu;
229 	struct ifnet *ifp = bp->bp_ifp;
230 	struct ether_header *eh;
231 	struct mbuf *m;
232 
233 	KASSERT(bp == bs->bs_root_port, ("%s: bad root port\n", __func__));
234 
235 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
236 		return;
237 
238 	MGETHDR(m, M_DONTWAIT, MT_DATA);
239 	if (m == NULL)
240 		return;
241 
242 	m->m_pkthdr.rcvif = ifp;
243 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
244 	m->m_len = m->m_pkthdr.len;
245 
246 	eh = mtod(m, struct ether_header *);
247 
248 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
249 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
250 	eh->ether_type = htons(sizeof(bpdu));
251 
252 	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
253 	bpdu.tbu_ctl = LLC_UI;
254 	bpdu.tbu_protoid = 0;
255 	bpdu.tbu_protover = 0;
256 	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
257 
258 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
259 
260 	bp->bp_txcount++;
261 	bstp_enqueue(ifp, m);
262 }
263 
264 static void
265 bstp_decode_bpdu(struct bstp_port *bp, struct bstp_cbpdu *cpdu,
266     struct bstp_config_unit *cu)
267 {
268 	int flags;
269 
270 	cu->cu_pv.pv_root_id =
271 	    (((uint64_t)ntohs(cpdu->cbu_rootpri)) << 48) |
272 	    (((uint64_t)cpdu->cbu_rootaddr[0]) << 40) |
273 	    (((uint64_t)cpdu->cbu_rootaddr[1]) << 32) |
274 	    (((uint64_t)cpdu->cbu_rootaddr[2]) << 24) |
275 	    (((uint64_t)cpdu->cbu_rootaddr[3]) << 16) |
276 	    (((uint64_t)cpdu->cbu_rootaddr[4]) << 8) |
277 	    (((uint64_t)cpdu->cbu_rootaddr[5]) << 0);
278 
279 	cu->cu_pv.pv_dbridge_id =
280 	    (((uint64_t)ntohs(cpdu->cbu_bridgepri)) << 48) |
281 	    (((uint64_t)cpdu->cbu_bridgeaddr[0]) << 40) |
282 	    (((uint64_t)cpdu->cbu_bridgeaddr[1]) << 32) |
283 	    (((uint64_t)cpdu->cbu_bridgeaddr[2]) << 24) |
284 	    (((uint64_t)cpdu->cbu_bridgeaddr[3]) << 16) |
285 	    (((uint64_t)cpdu->cbu_bridgeaddr[4]) << 8) |
286 	    (((uint64_t)cpdu->cbu_bridgeaddr[5]) << 0);
287 
288 	cu->cu_pv.pv_cost = ntohl(cpdu->cbu_rootpathcost);
289 	cu->cu_message_age = ntohs(cpdu->cbu_messageage);
290 	cu->cu_max_age = ntohs(cpdu->cbu_maxage);
291 	cu->cu_hello_time = ntohs(cpdu->cbu_hellotime);
292 	cu->cu_forward_delay = ntohs(cpdu->cbu_forwarddelay);
293 	cu->cu_pv.pv_dport_id = ntohs(cpdu->cbu_portid);
294 	cu->cu_pv.pv_port_id = bp->bp_port_id;
295 	cu->cu_message_type = cpdu->cbu_bpdutype;
296 
297 	/* Strip off unused flags in STP mode */
298 	flags = cpdu->cbu_flags;
299 	switch (cpdu->cbu_protover) {
300 		case BSTP_PROTO_STP:
301 			flags &= BSTP_PDU_STPMASK;
302 			/* A STP BPDU explicitly conveys a Designated Port */
303 			cu->cu_role = BSTP_ROLE_DESIGNATED;
304 			break;
305 
306 		case BSTP_PROTO_RSTP:
307 			flags &= BSTP_PDU_RSTPMASK;
308 			break;
309 	}
310 
311 	cu->cu_topology_change_ack =
312 		(flags & BSTP_PDU_F_TCA) ? 1 : 0;
313 	cu->cu_proposal =
314 		(flags & BSTP_PDU_F_P) ? 1 : 0;
315 	cu->cu_agree =
316 		(flags & BSTP_PDU_F_A) ? 1 : 0;
317 	cu->cu_learning =
318 		(flags & BSTP_PDU_F_L) ? 1 : 0;
319 	cu->cu_forwarding =
320 		(flags & BSTP_PDU_F_F) ? 1 : 0;
321 	cu->cu_topology_change =
322 		(flags & BSTP_PDU_F_TC) ? 1 : 0;
323 
324 	switch ((flags & BSTP_PDU_PRMASK) >> BSTP_PDU_PRSHIFT) {
325 		case BSTP_PDU_F_ROOT:
326 			cu->cu_role = BSTP_ROLE_ROOT;
327 			break;
328 		case BSTP_PDU_F_ALT:
329 			cu->cu_role = BSTP_ROLE_ALTERNATE;
330 			break;
331 		case BSTP_PDU_F_DESG:
332 			cu->cu_role = BSTP_ROLE_DESIGNATED;
333 			break;
334 	}
335 }
336 
337 static void
338 bstp_send_bpdu(struct bstp_state *bs, struct bstp_port *bp,
339     struct bstp_cbpdu *bpdu)
340 {
341 	struct ifnet *ifp;
342 	struct mbuf *m;
343 	struct ether_header *eh;
344 
345 	BSTP_LOCK_ASSERT(bs);
346 
347 	ifp = bp->bp_ifp;
348 
349 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
350 		return;
351 
352 	MGETHDR(m, M_DONTWAIT, MT_DATA);
353 	if (m == NULL)
354 		return;
355 
356 	eh = mtod(m, struct ether_header *);
357 
358 	bpdu->cbu_ssap = bpdu->cbu_dsap = LLC_8021D_LSAP;
359 	bpdu->cbu_ctl = LLC_UI;
360 	bpdu->cbu_protoid = htons(BSTP_PROTO_ID);
361 
362 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
363 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
364 
365 	switch (bpdu->cbu_bpdutype) {
366 		case BSTP_MSGTYPE_CFG:
367 			bpdu->cbu_protover = BSTP_PROTO_STP;
368 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_STP_LEN;
369 			eh->ether_type = htons(BSTP_BPDU_STP_LEN);
370 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
371 			    BSTP_BPDU_STP_LEN);
372 			break;
373 
374 		case BSTP_MSGTYPE_RSTP:
375 			bpdu->cbu_protover = BSTP_PROTO_RSTP;
376 			bpdu->cbu_versionlen = htons(0);
377 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_RSTP_LEN;
378 			eh->ether_type = htons(BSTP_BPDU_RSTP_LEN);
379 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
380 			    BSTP_BPDU_RSTP_LEN);
381 			break;
382 
383 		default:
384 			panic("not implemented");
385 	}
386 	m->m_pkthdr.rcvif = ifp;
387 	m->m_len = m->m_pkthdr.len;
388 
389 	bp->bp_txcount++;
390 	bstp_enqueue(ifp, m);
391 }
392 
393 static void
394 bstp_enqueue(struct ifnet *dst_ifp, struct mbuf *m)
395 {
396 	int err = 0;
397 
398 	IFQ_ENQUEUE(&dst_ifp->if_snd, m, err);
399 
400 	if ((dst_ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0)
401 		(*dst_ifp->if_start)(dst_ifp);
402 }
403 
404 static int
405 bstp_pdu_flags(struct bstp_port *bp)
406 {
407 	int flags = 0;
408 
409 	if (bp->bp_proposing && bp->bp_state != BSTP_IFSTATE_FORWARDING)
410 		flags |= BSTP_PDU_F_P;
411 
412 	if (bp->bp_agree)
413 		flags |= BSTP_PDU_F_A;
414 
415 	if (bp->bp_tc_timer.active)
416 		flags |= BSTP_PDU_F_TC;
417 
418 	if (bp->bp_tc_ack)
419 		flags |= BSTP_PDU_F_TCA;
420 
421 	switch (bp->bp_state) {
422 		case BSTP_IFSTATE_LEARNING:
423 			flags |= BSTP_PDU_F_L;
424 			break;
425 
426 		case BSTP_IFSTATE_FORWARDING:
427 			flags |= (BSTP_PDU_F_L | BSTP_PDU_F_F);
428 			break;
429 	}
430 
431 	switch (bp->bp_role) {
432 		case BSTP_ROLE_ROOT:
433 			flags |=
434 				(BSTP_PDU_F_ROOT << BSTP_PDU_PRSHIFT);
435 			break;
436 
437 		case BSTP_ROLE_ALTERNATE:
438 		case BSTP_ROLE_BACKUP:	/* fall through */
439 			flags |=
440 				(BSTP_PDU_F_ALT << BSTP_PDU_PRSHIFT);
441 			break;
442 
443 		case BSTP_ROLE_DESIGNATED:
444 			flags |=
445 				(BSTP_PDU_F_DESG << BSTP_PDU_PRSHIFT);
446 			break;
447 	}
448 
449 	/* Strip off unused flags in either mode */
450 	switch (bp->bp_protover) {
451 		case BSTP_PROTO_STP:
452 			flags &= BSTP_PDU_STPMASK;
453 			break;
454 		case BSTP_PROTO_RSTP:
455 			flags &= BSTP_PDU_RSTPMASK;
456 			break;
457 	}
458 	return (flags);
459 }
460 
461 struct mbuf *
462 bstp_input(struct bstp_port *bp, struct ifnet *ifp, struct mbuf *m)
463 {
464 	struct bstp_state *bs = bp->bp_bs;
465 	struct ether_header *eh;
466 	struct bstp_tbpdu tpdu;
467 	uint16_t len;
468 
469 	if (bp->bp_active == 0) {
470 		m_freem(m);
471 		return (NULL);
472 	}
473 
474 	BSTP_LOCK(bs);
475 
476 	eh = mtod(m, struct ether_header *);
477 
478 	len = ntohs(eh->ether_type);
479 	if (len < sizeof(tpdu))
480 		goto out;
481 
482 	m_adj(m, ETHER_HDR_LEN);
483 
484 	if (m->m_pkthdr.len > len)
485 		m_adj(m, len - m->m_pkthdr.len);
486 	if (m->m_len < sizeof(tpdu) &&
487 	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
488 		goto out;
489 
490 	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
491 
492 	/* basic packet checks */
493 	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
494 	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
495 	    tpdu.tbu_ctl != LLC_UI)
496 		goto out;
497 	if (tpdu.tbu_protoid != BSTP_PROTO_ID)
498 		goto out;
499 
500 	/*
501 	 * We can treat later versions of the PDU as the same as the maximum
502 	 * version we implement. All additional parameters/flags are ignored.
503 	 */
504 	if (tpdu.tbu_protover > BSTP_PROTO_MAX)
505 		tpdu.tbu_protover = BSTP_PROTO_MAX;
506 
507 	if (tpdu.tbu_protover != bp->bp_protover) {
508 		/*
509 		 * Wait for the migration delay timer to expire before changing
510 		 * protocol version to avoid flip-flops.
511 		 */
512 		if (bp->bp_flags & BSTP_PORT_CANMIGRATE)
513 			bstp_set_port_proto(bp, tpdu.tbu_protover);
514 		else
515 			goto out;
516 	}
517 
518 	/* Clear operedge upon receiving a PDU on the port */
519 	bp->bp_operedge = 0;
520 	bstp_timer_start(&bp->bp_edge_delay_timer,
521 	    BSTP_DEFAULT_MIGRATE_DELAY);
522 
523 	switch (tpdu.tbu_protover) {
524 		case BSTP_PROTO_STP:
525 			bstp_received_stp(bs, bp, &m, &tpdu);
526 			break;
527 
528 		case BSTP_PROTO_RSTP:
529 			bstp_received_rstp(bs, bp, &m, &tpdu);
530 			break;
531 	}
532 out:
533 	BSTP_UNLOCK(bs);
534 	if (m)
535 		m_freem(m);
536 	return (NULL);
537 }
538 
539 static void
540 bstp_received_stp(struct bstp_state *bs, struct bstp_port *bp,
541     struct mbuf **mp, struct bstp_tbpdu *tpdu)
542 {
543 	struct bstp_cbpdu cpdu;
544 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
545 	struct bstp_tcn_unit tu;
546 
547 	switch (tpdu->tbu_bpdutype) {
548 	case BSTP_MSGTYPE_TCN:
549 		tu.tu_message_type = tpdu->tbu_bpdutype;
550 		bstp_received_tcn(bs, bp, &tu);
551 		break;
552 	case BSTP_MSGTYPE_CFG:
553 		if ((*mp)->m_len < BSTP_BPDU_STP_LEN &&
554 		    (*mp = m_pullup(*mp, BSTP_BPDU_STP_LEN)) == NULL)
555 			return;
556 		memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_STP_LEN);
557 
558 		bstp_decode_bpdu(bp, &cpdu, cu);
559 		bstp_received_bpdu(bs, bp, cu);
560 		break;
561 	}
562 }
563 
564 static void
565 bstp_received_rstp(struct bstp_state *bs, struct bstp_port *bp,
566     struct mbuf **mp, struct bstp_tbpdu *tpdu)
567 {
568 	struct bstp_cbpdu cpdu;
569 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
570 
571 	if (tpdu->tbu_bpdutype != BSTP_MSGTYPE_RSTP)
572 		return;
573 
574 	if ((*mp)->m_len < BSTP_BPDU_RSTP_LEN &&
575 	    (*mp = m_pullup(*mp, BSTP_BPDU_RSTP_LEN)) == NULL)
576 		return;
577 	memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_RSTP_LEN);
578 
579 	bstp_decode_bpdu(bp, &cpdu, cu);
580 	bstp_received_bpdu(bs, bp, cu);
581 }
582 
583 static void
584 bstp_received_tcn(struct bstp_state *bs, struct bstp_port *bp,
585     struct bstp_tcn_unit *tcn)
586 {
587 	bp->bp_rcvdtcn = 1;
588 	bstp_update_tc(bp);
589 }
590 
591 static void
592 bstp_received_bpdu(struct bstp_state *bs, struct bstp_port *bp,
593     struct bstp_config_unit *cu)
594 {
595 	int type;
596 
597 	BSTP_LOCK_ASSERT(bs);
598 
599 	/* We need to have transitioned to INFO_MINE before proceeding */
600 	switch (bp->bp_infois) {
601 		case BSTP_INFO_DISABLED:
602 		case BSTP_INFO_AGED:
603 			return;
604 	}
605 
606 	type = bstp_pdu_rcvtype(bp, cu);
607 
608 	switch (type) {
609 		case BSTP_PDU_SUPERIOR:
610 			bs->bs_allsynced = 0;
611 			bp->bp_agreed = 0;
612 			bp->bp_proposing = 0;
613 
614 			if (cu->cu_proposal && cu->cu_forwarding == 0)
615 				bp->bp_proposed = 1;
616 			if (cu->cu_topology_change)
617 				bp->bp_rcvdtc = 1;
618 			if (cu->cu_topology_change_ack)
619 				bp->bp_rcvdtca = 1;
620 
621 			if (bp->bp_agree &&
622 			    !bstp_pdu_bettersame(bp, BSTP_INFO_RECEIVED))
623 				bp->bp_agree = 0;
624 
625 			/* copy the received priority and timers to the port */
626 			bp->bp_port_pv = cu->cu_pv;
627 			bp->bp_port_msg_age = cu->cu_message_age;
628 			bp->bp_port_max_age = cu->cu_max_age;
629 			bp->bp_port_fdelay = cu->cu_forward_delay;
630 			bp->bp_port_htime =
631 				(cu->cu_hello_time > BSTP_MIN_HELLO_TIME ?
632 				 cu->cu_hello_time : BSTP_MIN_HELLO_TIME);
633 
634 			/* set expiry for the new info */
635 			bstp_set_timer_msgage(bp);
636 
637 			bp->bp_infois = BSTP_INFO_RECEIVED;
638 			bstp_assign_roles(bs);
639 			break;
640 
641 		case BSTP_PDU_REPEATED:
642 			if (cu->cu_proposal && cu->cu_forwarding == 0)
643 				bp->bp_proposed = 1;
644 			if (cu->cu_topology_change)
645 				bp->bp_rcvdtc = 1;
646 			if (cu->cu_topology_change_ack)
647 				bp->bp_rcvdtca = 1;
648 
649 			/* rearm the age timer */
650 			bstp_set_timer_msgage(bp);
651 			break;
652 
653 		case BSTP_PDU_INFERIOR:
654 			if (cu->cu_learning) {
655 				bp->bp_agreed = 1;
656 				bp->bp_proposing = 0;
657 			}
658 			break;
659 
660 		case BSTP_PDU_INFERIORALT:
661 			/*
662 			 * only point to point links are allowed fast
663 			 * transitions to forwarding.
664 			 */
665 			if (cu->cu_agree && bp->bp_ptp_link) {
666 				bp->bp_agreed = 1;
667 				bp->bp_proposing = 0;
668 			} else
669 				bp->bp_agreed = 0;
670 
671 			if (cu->cu_topology_change)
672 				bp->bp_rcvdtc = 1;
673 			if (cu->cu_topology_change_ack)
674 				bp->bp_rcvdtca = 1;
675 			break;
676 
677 		case BSTP_PDU_OTHER:
678 			return;	/* do nothing */
679 	}
680 	/* update the state machines with the new data */
681 	bstp_update_state(bs, bp);
682 }
683 
684 static int
685 bstp_pdu_rcvtype(struct bstp_port *bp, struct bstp_config_unit *cu)
686 {
687 	int type;
688 
689 	/* default return type */
690 	type = BSTP_PDU_OTHER;
691 
692 	switch (cu->cu_role) {
693 	case BSTP_ROLE_DESIGNATED:
694 		if (bstp_info_superior(&bp->bp_port_pv, &cu->cu_pv))
695 			/* bpdu priority is superior */
696 			type = BSTP_PDU_SUPERIOR;
697 		else if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) ==
698 		    INFO_SAME) {
699 			if (bp->bp_port_msg_age != cu->cu_message_age ||
700 			    bp->bp_port_max_age != cu->cu_max_age ||
701 			    bp->bp_port_fdelay != cu->cu_forward_delay ||
702 			    bp->bp_port_htime != cu->cu_hello_time)
703 				/* bpdu priority is equal and timers differ */
704 				type = BSTP_PDU_SUPERIOR;
705 			else
706 				/* bpdu is equal */
707 				type = BSTP_PDU_REPEATED;
708 		} else
709 			/* bpdu priority is worse */
710 			type = BSTP_PDU_INFERIOR;
711 
712 		break;
713 
714 	case BSTP_ROLE_ROOT:
715 	case BSTP_ROLE_ALTERNATE:
716 	case BSTP_ROLE_BACKUP:
717 		if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) <= INFO_SAME)
718 			/*
719 			 * not a designated port and priority is the same or
720 			 * worse
721 			 */
722 			type = BSTP_PDU_INFERIORALT;
723 		break;
724 	}
725 
726 	return (type);
727 }
728 
729 static int
730 bstp_pdu_bettersame(struct bstp_port *bp, int newinfo)
731 {
732 	if (newinfo == BSTP_INFO_RECEIVED &&
733 	    bp->bp_infois == BSTP_INFO_RECEIVED &&
734 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_msg_cu.cu_pv) >= INFO_SAME)
735 		return (1);
736 
737 	if (newinfo == BSTP_INFO_MINE &&
738 	    bp->bp_infois == BSTP_INFO_MINE &&
739 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_desg_pv) >= INFO_SAME)
740 		return (1);
741 
742 	return (0);
743 }
744 
745 static int
746 bstp_info_cmp(struct bstp_pri_vector *pv,
747     struct bstp_pri_vector *cpv)
748 {
749 	if (cpv->pv_root_id < pv->pv_root_id)
750 		return (INFO_BETTER);
751 	if (cpv->pv_root_id > pv->pv_root_id)
752 		return (INFO_WORSE);
753 
754 	if (cpv->pv_cost < pv->pv_cost)
755 		return (INFO_BETTER);
756 	if (cpv->pv_cost > pv->pv_cost)
757 		return (INFO_WORSE);
758 
759 	if (cpv->pv_dbridge_id < pv->pv_dbridge_id)
760 		return (INFO_BETTER);
761 	if (cpv->pv_dbridge_id > pv->pv_dbridge_id)
762 		return (INFO_WORSE);
763 
764 	if (cpv->pv_dport_id < pv->pv_dport_id)
765 		return (INFO_BETTER);
766 	if (cpv->pv_dport_id > pv->pv_dport_id)
767 		return (INFO_WORSE);
768 
769 	return (INFO_SAME);
770 }
771 
772 /*
773  * This message priority vector is superior to the port priority vector and
774  * will replace it if, and only if, the message priority vector is better than
775  * the port priority vector, or the message has been transmitted from the same
776  * designated bridge and designated port as the port priority vector.
777  */
778 static int
779 bstp_info_superior(struct bstp_pri_vector *pv,
780     struct bstp_pri_vector *cpv)
781 {
782 	if (bstp_info_cmp(pv, cpv) == INFO_BETTER ||
783 	    (bstp_same_bridgeid(pv->pv_dbridge_id, cpv->pv_dbridge_id) &&
784 	    (cpv->pv_dport_id & 0xfff) == (pv->pv_dport_id & 0xfff)))
785 		return (1);
786 	return (0);
787 }
788 
789 static void
790 bstp_assign_roles(struct bstp_state *bs)
791 {
792 	struct bstp_port *bp, *rbp = NULL;
793 	struct bstp_pri_vector pv;
794 
795 	/* default to our priority vector */
796 	bs->bs_root_pv = bs->bs_bridge_pv;
797 	bs->bs_root_msg_age = 0;
798 	bs->bs_root_max_age = bs->bs_bridge_max_age;
799 	bs->bs_root_fdelay = bs->bs_bridge_fdelay;
800 	bs->bs_root_htime = bs->bs_bridge_htime;
801 	bs->bs_root_port = NULL;
802 
803 	/* check if any recieved info supersedes us */
804 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
805 		if (bp->bp_infois != BSTP_INFO_RECEIVED)
806 			continue;
807 
808 		pv = bp->bp_port_pv;
809 		pv.pv_cost += bp->bp_path_cost;
810 
811 		/*
812 		 * The root priority vector is the best of the set comprising
813 		 * the bridge priority vector plus all root path priority
814 		 * vectors whose bridge address is not equal to us.
815 		 */
816 		if (bstp_same_bridgeid(pv.pv_dbridge_id,
817 		    bs->bs_bridge_pv.pv_dbridge_id) == 0 &&
818 		    bstp_info_cmp(&bs->bs_root_pv, &pv) == INFO_BETTER) {
819 			/* the port vector replaces the root */
820 			bs->bs_root_pv = pv;
821 			bs->bs_root_msg_age = bp->bp_port_msg_age +
822 			    BSTP_MESSAGE_AGE_INCR;
823 			bs->bs_root_max_age = bp->bp_port_max_age;
824 			bs->bs_root_fdelay = bp->bp_port_fdelay;
825 			bs->bs_root_htime = bp->bp_port_htime;
826 			rbp = bp;
827 		}
828 	}
829 
830 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
831 		/* calculate the port designated vector */
832 		bp->bp_desg_pv.pv_root_id = bs->bs_root_pv.pv_root_id;
833 		bp->bp_desg_pv.pv_cost = bs->bs_root_pv.pv_cost;
834 		bp->bp_desg_pv.pv_dbridge_id = bs->bs_bridge_pv.pv_dbridge_id;
835 		bp->bp_desg_pv.pv_dport_id = bp->bp_port_id;
836 		bp->bp_desg_pv.pv_port_id = bp->bp_port_id;
837 
838 		/* calculate designated times */
839 		bp->bp_desg_msg_age = bs->bs_root_msg_age;
840 		bp->bp_desg_max_age = bs->bs_root_max_age;
841 		bp->bp_desg_fdelay = bs->bs_root_fdelay;
842 		bp->bp_desg_htime = bs->bs_bridge_htime;
843 
844 
845 		switch (bp->bp_infois) {
846 		case BSTP_INFO_DISABLED:
847 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
848 			break;
849 
850 		case BSTP_INFO_AGED:
851 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
852 			bstp_update_info(bp);
853 			break;
854 
855 		case BSTP_INFO_MINE:
856 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
857 			/* update the port info if stale */
858 			if (bstp_info_cmp(&bp->bp_port_pv,
859 			    &bp->bp_desg_pv) != INFO_SAME ||
860 			    (rbp != NULL &&
861 			    (bp->bp_port_msg_age != rbp->bp_port_msg_age ||
862 			    bp->bp_port_max_age != rbp->bp_port_max_age ||
863 			    bp->bp_port_fdelay != rbp->bp_port_fdelay ||
864 			    bp->bp_port_htime != rbp->bp_port_htime)))
865 				bstp_update_info(bp);
866 			break;
867 
868 		case BSTP_INFO_RECEIVED:
869 			if (bp == rbp) {
870 				/*
871 				 * root priority is derived from this
872 				 * port, make it the root port.
873 				 */
874 				bstp_set_port_role(bp, BSTP_ROLE_ROOT);
875 				bs->bs_root_port = bp;
876 			} else if (bstp_info_cmp(&bp->bp_port_pv,
877 				    &bp->bp_desg_pv) == INFO_BETTER) {
878 				/*
879 				 * the port priority is lower than the root
880 				 * port.
881 				 */
882 				bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
883 				bstp_update_info(bp);
884 			} else {
885 				if (bstp_same_bridgeid(
886 				    bp->bp_port_pv.pv_dbridge_id,
887 				    bs->bs_bridge_pv.pv_dbridge_id)) {
888 					/*
889 					 * the designated bridge refers to
890 					 * another port on this bridge.
891 					 */
892 					bstp_set_port_role(bp,
893 					    BSTP_ROLE_BACKUP);
894 				} else {
895 					/*
896 					 * the port is an inferior path to the
897 					 * root bridge.
898 					 */
899 					bstp_set_port_role(bp,
900 					    BSTP_ROLE_ALTERNATE);
901 				}
902 			}
903 			break;
904 		}
905 	}
906 }
907 
908 static void
909 bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
910 {
911 	struct bstp_port *bp2;
912 	int synced;
913 
914 	BSTP_LOCK_ASSERT(bs);
915 
916 	/* check if all the ports have syncronised again */
917 	if (!bs->bs_allsynced) {
918 		synced = 1;
919 		LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
920 			if (!(bp2->bp_synced ||
921 			     bp2->bp_role == BSTP_ROLE_ROOT)) {
922 				synced = 0;
923 				break;
924 			}
925 		}
926 		bs->bs_allsynced = synced;
927 	}
928 
929 	bstp_update_roles(bs, bp);
930 	bstp_update_tc(bp);
931 }
932 
933 static void
934 bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
935 {
936 	switch (bp->bp_role) {
937 	case BSTP_ROLE_DISABLED:
938 		/* Clear any flags if set */
939 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
940 			bp->bp_sync = 0;
941 			bp->bp_synced = 1;
942 			bp->bp_reroot = 0;
943 		}
944 		break;
945 
946 	case BSTP_ROLE_ALTERNATE:
947 	case BSTP_ROLE_BACKUP:
948 		if ((bs->bs_allsynced && !bp->bp_agree) ||
949 		    (bp->bp_proposed && bp->bp_agree)) {
950 			bp->bp_proposed = 0;
951 			bp->bp_agree = 1;
952 			bp->bp_flags |= BSTP_PORT_NEWINFO;
953 			DPRINTF("%s -> ALTERNATE_AGREED\n",
954 			    bp->bp_ifp->if_xname);
955 		}
956 
957 		if (bp->bp_proposed && !bp->bp_agree) {
958 			bstp_set_all_sync(bs);
959 			bp->bp_proposed = 0;
960 			DPRINTF("%s -> ALTERNATE_PROPOSED\n",
961 			    bp->bp_ifp->if_xname);
962 		}
963 
964 		/* Clear any flags if set */
965 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
966 			bp->bp_sync = 0;
967 			bp->bp_synced = 1;
968 			bp->bp_reroot = 0;
969 			DPRINTF("%s -> ALTERNATE_PORT\n", bp->bp_ifp->if_xname);
970 		}
971 		break;
972 
973 	case BSTP_ROLE_ROOT:
974 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING && !bp->bp_reroot) {
975 			bstp_set_all_reroot(bs);
976 			DPRINTF("%s -> ROOT_REROOT\n", bp->bp_ifp->if_xname);
977 		}
978 
979 		if ((bs->bs_allsynced && !bp->bp_agree) ||
980 		    (bp->bp_proposed && bp->bp_agree)) {
981 			bp->bp_proposed = 0;
982 			bp->bp_sync = 0;
983 			bp->bp_agree = 1;
984 			bp->bp_flags |= BSTP_PORT_NEWINFO;
985 			DPRINTF("%s -> ROOT_AGREED\n", bp->bp_ifp->if_xname);
986 		}
987 
988 		if (bp->bp_proposed && !bp->bp_agree) {
989 			bstp_set_all_sync(bs);
990 			bp->bp_proposed = 0;
991 			DPRINTF("%s -> ROOT_PROPOSED\n", bp->bp_ifp->if_xname);
992 		}
993 
994 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
995 		    (bp->bp_forward_delay_timer.active == 0 ||
996 		    (bstp_rerooted(bs, bp) &&
997 		    bp->bp_recent_backup_timer.active == 0 &&
998 		    bp->bp_protover == BSTP_PROTO_RSTP))) {
999 			switch (bp->bp_state) {
1000 			case BSTP_IFSTATE_DISCARDING:
1001 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
1002 				break;
1003 			case BSTP_IFSTATE_LEARNING:
1004 				bstp_set_port_state(bp,
1005 				    BSTP_IFSTATE_FORWARDING);
1006 				break;
1007 			}
1008 		}
1009 
1010 		if (bp->bp_state == BSTP_IFSTATE_FORWARDING && bp->bp_reroot) {
1011 			bp->bp_reroot = 0;
1012 			DPRINTF("%s -> ROOT_REROOTED\n", bp->bp_ifp->if_xname);
1013 		}
1014 		break;
1015 
1016 	case BSTP_ROLE_DESIGNATED:
1017 		if (bp->bp_recent_root_timer.active == 0 && bp->bp_reroot) {
1018 			bp->bp_reroot = 0;
1019 			DPRINTF("%s -> DESIGNATED_RETIRED\n",
1020 			    bp->bp_ifp->if_xname);
1021 		}
1022 
1023 		if ((bp->bp_state == BSTP_IFSTATE_DISCARDING &&
1024 		    !bp->bp_synced) || (bp->bp_agreed && !bp->bp_synced) ||
1025 		    (bp->bp_operedge && !bp->bp_synced) ||
1026 		    (bp->bp_sync && bp->bp_synced)) {
1027 			bstp_timer_stop(&bp->bp_recent_root_timer);
1028 			bp->bp_synced = 1;
1029 			bp->bp_sync = 0;
1030 			DPRINTF("%s -> DESIGNATED_SYNCED\n",
1031 			    bp->bp_ifp->if_xname);
1032 		}
1033 
1034 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1035 		    !bp->bp_agreed && !bp->bp_proposing &&
1036 		    !bp->bp_operedge) {
1037 			bp->bp_proposing = 1;
1038 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1039 			bstp_timer_start(&bp->bp_edge_delay_timer,
1040 			    (bp->bp_ptp_link ? BSTP_DEFAULT_MIGRATE_DELAY :
1041 			     bp->bp_desg_max_age));
1042 			DPRINTF("%s -> DESIGNATED_PROPOSE\n",
1043 			    bp->bp_ifp->if_xname);
1044 		}
1045 
1046 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1047 		    (bp->bp_forward_delay_timer.active == 0 || bp->bp_agreed ||
1048 		    bp->bp_operedge) &&
1049 		    (bp->bp_recent_root_timer.active == 0 || !bp->bp_reroot) &&
1050 		    !bp->bp_sync) {
1051 			if (bp->bp_agreed)
1052 				DPRINTF("%s -> AGREED\n", bp->bp_ifp->if_xname);
1053 			/*
1054 			 * If agreed|operedge then go straight to forwarding,
1055 			 * otherwise follow discard -> learn -> forward.
1056 			 */
1057 			if (bp->bp_agreed || bp->bp_operedge ||
1058 			    bp->bp_state == BSTP_IFSTATE_LEARNING) {
1059 				bstp_set_port_state(bp,
1060 				    BSTP_IFSTATE_FORWARDING);
1061 				bp->bp_agreed = bp->bp_protover;
1062 			} else if (bp->bp_state == BSTP_IFSTATE_DISCARDING)
1063 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
1064 		}
1065 
1066 		if (((bp->bp_sync && !bp->bp_synced) ||
1067 		    (bp->bp_reroot && bp->bp_recent_root_timer.active) ||
1068 		    (bp->bp_flags & BSTP_PORT_DISPUTED)) && !bp->bp_operedge &&
1069 		    bp->bp_state != BSTP_IFSTATE_DISCARDING) {
1070 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1071 			bp->bp_flags &= ~BSTP_PORT_DISPUTED;
1072 			bstp_timer_start(&bp->bp_forward_delay_timer,
1073 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1074 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1075 			DPRINTF("%s -> DESIGNATED_DISCARD\n",
1076 			    bp->bp_ifp->if_xname);
1077 		}
1078 		break;
1079 	}
1080 
1081 	if (bp->bp_flags & BSTP_PORT_NEWINFO)
1082 		bstp_transmit(bs, bp);
1083 }
1084 
1085 static void
1086 bstp_update_tc(struct bstp_port *bp)
1087 {
1088 	switch (bp->bp_tcstate) {
1089 		case BSTP_TCSTATE_ACTIVE:
1090 			if ((bp->bp_role != BSTP_ROLE_DESIGNATED &&
1091 			    bp->bp_role != BSTP_ROLE_ROOT) || bp->bp_operedge)
1092 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1093 
1094 			if (bp->bp_rcvdtcn)
1095 				bstp_set_port_tc(bp, BSTP_TCSTATE_TCN);
1096 			if (bp->bp_rcvdtc)
1097 				bstp_set_port_tc(bp, BSTP_TCSTATE_TC);
1098 
1099 			if (bp->bp_tc_prop && !bp->bp_operedge)
1100 				bstp_set_port_tc(bp, BSTP_TCSTATE_PROPAG);
1101 
1102 			if (bp->bp_rcvdtca)
1103 				bstp_set_port_tc(bp, BSTP_TCSTATE_ACK);
1104 			break;
1105 
1106 		case BSTP_TCSTATE_INACTIVE:
1107 			if ((bp->bp_state == BSTP_IFSTATE_LEARNING ||
1108 			    bp->bp_state == BSTP_IFSTATE_FORWARDING) &&
1109 			    bp->bp_fdbflush == 0)
1110 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1111 			break;
1112 
1113 		case BSTP_TCSTATE_LEARNING:
1114 			if (bp->bp_rcvdtc || bp->bp_rcvdtcn || bp->bp_rcvdtca ||
1115 			    bp->bp_tc_prop)
1116 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1117 			else if (bp->bp_role != BSTP_ROLE_DESIGNATED &&
1118 				 bp->bp_role != BSTP_ROLE_ROOT &&
1119 				 bp->bp_state == BSTP_IFSTATE_DISCARDING)
1120 				bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1121 
1122 			if ((bp->bp_role == BSTP_ROLE_DESIGNATED ||
1123 			    bp->bp_role == BSTP_ROLE_ROOT) &&
1124 			    bp->bp_state == BSTP_IFSTATE_FORWARDING &&
1125 			    !bp->bp_operedge)
1126 				bstp_set_port_tc(bp, BSTP_TCSTATE_DETECTED);
1127 			break;
1128 
1129 		/* these are transient states and go straight back to ACTIVE */
1130 		case BSTP_TCSTATE_DETECTED:
1131 		case BSTP_TCSTATE_TCN:
1132 		case BSTP_TCSTATE_TC:
1133 		case BSTP_TCSTATE_PROPAG:
1134 		case BSTP_TCSTATE_ACK:
1135 			DPRINTF("Invalid TC state for %s\n",
1136 			    bp->bp_ifp->if_xname);
1137 			break;
1138 	}
1139 
1140 }
1141 
1142 static void
1143 bstp_update_info(struct bstp_port *bp)
1144 {
1145 	struct bstp_state *bs = bp->bp_bs;
1146 
1147 	bp->bp_proposing = 0;
1148 	bp->bp_proposed = 0;
1149 
1150 	if (bp->bp_agreed && !bstp_pdu_bettersame(bp, BSTP_INFO_MINE))
1151 		bp->bp_agreed = 0;
1152 
1153 	if (bp->bp_synced && !bp->bp_agreed) {
1154 		bp->bp_synced = 0;
1155 		bs->bs_allsynced = 0;
1156 	}
1157 
1158 	/* copy the designated pv to the port */
1159 	bp->bp_port_pv = bp->bp_desg_pv;
1160 	bp->bp_port_msg_age = bp->bp_desg_msg_age;
1161 	bp->bp_port_max_age = bp->bp_desg_max_age;
1162 	bp->bp_port_fdelay = bp->bp_desg_fdelay;
1163 	bp->bp_port_htime = bp->bp_desg_htime;
1164 	bp->bp_infois = BSTP_INFO_MINE;
1165 
1166 	/* Set transmit flag but do not immediately send */
1167 	bp->bp_flags |= BSTP_PORT_NEWINFO;
1168 }
1169 
1170 /* set tcprop on every port other than the caller */
1171 static void
1172 bstp_set_other_tcprop(struct bstp_port *bp)
1173 {
1174 	struct bstp_state *bs = bp->bp_bs;
1175 	struct bstp_port *bp2;
1176 
1177 	BSTP_LOCK_ASSERT(bs);
1178 
1179 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1180 		if (bp2 == bp)
1181 			continue;
1182 		bp2->bp_tc_prop = 1;
1183 	}
1184 }
1185 
1186 static void
1187 bstp_set_all_reroot(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_reroot = 1;
1195 }
1196 
1197 static void
1198 bstp_set_all_sync(struct bstp_state *bs)
1199 {
1200 	struct bstp_port *bp;
1201 
1202 	BSTP_LOCK_ASSERT(bs);
1203 
1204 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1205 		bp->bp_sync = 1;
1206 		bp->bp_synced = 0;	/* Not explicit in spec */
1207 	}
1208 
1209 	bs->bs_allsynced = 0;
1210 }
1211 
1212 static void
1213 bstp_set_port_state(struct bstp_port *bp, int state)
1214 {
1215 	if (bp->bp_state == state)
1216 		return;
1217 
1218 	bp->bp_state = state;
1219 
1220 	switch (bp->bp_state) {
1221 		case BSTP_IFSTATE_DISCARDING:
1222 			DPRINTF("state changed to DISCARDING on %s\n",
1223 			    bp->bp_ifp->if_xname);
1224 			break;
1225 
1226 		case BSTP_IFSTATE_LEARNING:
1227 			DPRINTF("state changed to LEARNING on %s\n",
1228 			    bp->bp_ifp->if_xname);
1229 
1230 			bstp_timer_start(&bp->bp_forward_delay_timer,
1231 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1232 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1233 			break;
1234 
1235 		case BSTP_IFSTATE_FORWARDING:
1236 			DPRINTF("state changed to FORWARDING on %s\n",
1237 			    bp->bp_ifp->if_xname);
1238 
1239 			bstp_timer_stop(&bp->bp_forward_delay_timer);
1240 			/* Record that we enabled forwarding */
1241 			bp->bp_forward_transitions++;
1242 			break;
1243 	}
1244 
1245 	/* notify the parent bridge */
1246 	taskqueue_enqueue(taskqueue_swi, &bp->bp_statetask);
1247 }
1248 
1249 static void
1250 bstp_set_port_role(struct bstp_port *bp, int role)
1251 {
1252 	struct bstp_state *bs = bp->bp_bs;
1253 
1254 	if (bp->bp_role == role)
1255 		return;
1256 
1257 	/* perform pre-change tasks */
1258 	switch (bp->bp_role) {
1259 		case BSTP_ROLE_DISABLED:
1260 			bstp_timer_start(&bp->bp_forward_delay_timer,
1261 			    bp->bp_desg_max_age);
1262 			break;
1263 
1264 		case BSTP_ROLE_BACKUP:
1265 			bstp_timer_start(&bp->bp_recent_backup_timer,
1266 			    bp->bp_desg_htime * 2);
1267 			/* fall through */
1268 		case BSTP_ROLE_ALTERNATE:
1269 			bstp_timer_start(&bp->bp_forward_delay_timer,
1270 			    bp->bp_desg_fdelay);
1271 			bp->bp_sync = 0;
1272 			bp->bp_synced = 1;
1273 			bp->bp_reroot = 0;
1274 			break;
1275 
1276 		case BSTP_ROLE_ROOT:
1277 			bstp_timer_start(&bp->bp_recent_root_timer,
1278 			    BSTP_DEFAULT_FORWARD_DELAY);
1279 			break;
1280 	}
1281 
1282 	bp->bp_role = role;
1283 	/* clear values not carried between roles */
1284 	bp->bp_proposing = 0;
1285 	bs->bs_allsynced = 0;
1286 
1287 	/* initialise the new role */
1288 	switch (bp->bp_role) {
1289 		case BSTP_ROLE_DISABLED:
1290 		case BSTP_ROLE_ALTERNATE:
1291 		case BSTP_ROLE_BACKUP:
1292 			DPRINTF("%s role -> ALT/BACK/DISABLED\n",
1293 			    bp->bp_ifp->if_xname);
1294 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1295 			bstp_timer_stop(&bp->bp_recent_root_timer);
1296 			bstp_timer_latch(&bp->bp_forward_delay_timer);
1297 			bp->bp_sync = 0;
1298 			bp->bp_synced = 1;
1299 			bp->bp_reroot = 0;
1300 			break;
1301 
1302 		case BSTP_ROLE_ROOT:
1303 			DPRINTF("%s role -> ROOT\n",
1304 			    bp->bp_ifp->if_xname);
1305 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1306 			bstp_timer_latch(&bp->bp_recent_root_timer);
1307 			bp->bp_proposing = 0;
1308 			break;
1309 
1310 		case BSTP_ROLE_DESIGNATED:
1311 			DPRINTF("%s role -> DESIGNATED\n",
1312 			    bp->bp_ifp->if_xname);
1313 			bstp_timer_start(&bp->bp_hello_timer,
1314 			    bp->bp_desg_htime);
1315 			bp->bp_agree = 0;
1316 			break;
1317 	}
1318 
1319 	/* let the TC state know that the role changed */
1320 	bstp_update_tc(bp);
1321 }
1322 
1323 static void
1324 bstp_set_port_proto(struct bstp_port *bp, int proto)
1325 {
1326 	struct bstp_state *bs = bp->bp_bs;
1327 
1328 	/* supported protocol versions */
1329 	switch (proto) {
1330 		case BSTP_PROTO_STP:
1331 			/* we can downgrade protocols only */
1332 			bstp_timer_stop(&bp->bp_migrate_delay_timer);
1333 			/* clear unsupported features */
1334 			bp->bp_operedge = 0;
1335 			/* STP compat mode only uses 16 bits of the 32 */
1336 			if (bp->bp_path_cost > 65535)
1337 				bp->bp_path_cost = 65535;
1338 			break;
1339 
1340 		case BSTP_PROTO_RSTP:
1341 			bstp_timer_start(&bp->bp_migrate_delay_timer,
1342 			    bs->bs_migration_delay);
1343 			break;
1344 
1345 		default:
1346 			DPRINTF("Unsupported STP version %d\n", proto);
1347 			return;
1348 	}
1349 
1350 	bp->bp_protover = proto;
1351 	bp->bp_flags &= ~BSTP_PORT_CANMIGRATE;
1352 }
1353 
1354 static void
1355 bstp_set_port_tc(struct bstp_port *bp, int state)
1356 {
1357 	struct bstp_state *bs = bp->bp_bs;
1358 
1359 	bp->bp_tcstate = state;
1360 
1361 	/* initialise the new state */
1362 	switch (bp->bp_tcstate) {
1363 		case BSTP_TCSTATE_ACTIVE:
1364 			DPRINTF("%s -> TC_ACTIVE\n", bp->bp_ifp->if_xname);
1365 			/* nothing to do */
1366 			break;
1367 
1368 		case BSTP_TCSTATE_INACTIVE:
1369 			bstp_timer_stop(&bp->bp_tc_timer);
1370 			/* flush routes on the parent bridge */
1371 			bp->bp_fdbflush = 1;
1372 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1373 			bp->bp_tc_ack = 0;
1374 			DPRINTF("%s -> TC_INACTIVE\n", bp->bp_ifp->if_xname);
1375 			break;
1376 
1377 		case BSTP_TCSTATE_LEARNING:
1378 			bp->bp_rcvdtc = 0;
1379 			bp->bp_rcvdtcn = 0;
1380 			bp->bp_rcvdtca = 0;
1381 			bp->bp_tc_prop = 0;
1382 			DPRINTF("%s -> TC_LEARNING\n", bp->bp_ifp->if_xname);
1383 			break;
1384 
1385 		case BSTP_TCSTATE_DETECTED:
1386 			bstp_set_timer_tc(bp);
1387 			bstp_set_other_tcprop(bp);
1388 			/* send out notification */
1389 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1390 			bstp_transmit(bs, bp);
1391 			getmicrotime(&bs->bs_last_tc_time);
1392 			DPRINTF("%s -> TC_DETECTED\n", bp->bp_ifp->if_xname);
1393 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1394 			break;
1395 
1396 		case BSTP_TCSTATE_TCN:
1397 			bstp_set_timer_tc(bp);
1398 			DPRINTF("%s -> TC_TCN\n", bp->bp_ifp->if_xname);
1399 			/* fall through */
1400 		case BSTP_TCSTATE_TC:
1401 			bp->bp_rcvdtc = 0;
1402 			bp->bp_rcvdtcn = 0;
1403 			if (bp->bp_role == BSTP_ROLE_DESIGNATED)
1404 				bp->bp_tc_ack = 1;
1405 
1406 			bstp_set_other_tcprop(bp);
1407 			DPRINTF("%s -> TC_TC\n", bp->bp_ifp->if_xname);
1408 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1409 			break;
1410 
1411 		case BSTP_TCSTATE_PROPAG:
1412 			/* flush routes on the parent bridge */
1413 			bp->bp_fdbflush = 1;
1414 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1415 			bp->bp_tc_prop = 0;
1416 			bstp_set_timer_tc(bp);
1417 			DPRINTF("%s -> TC_PROPAG\n", bp->bp_ifp->if_xname);
1418 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1419 			break;
1420 
1421 		case BSTP_TCSTATE_ACK:
1422 			bstp_timer_stop(&bp->bp_tc_timer);
1423 			bp->bp_rcvdtca = 0;
1424 			DPRINTF("%s -> TC_ACK\n", bp->bp_ifp->if_xname);
1425 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1426 			break;
1427 	}
1428 }
1429 
1430 static void
1431 bstp_set_timer_tc(struct bstp_port *bp)
1432 {
1433 	struct bstp_state *bs = bp->bp_bs;
1434 
1435 	if (bp->bp_tc_timer.active)
1436 		return;
1437 
1438 	switch (bp->bp_protover) {
1439 		case BSTP_PROTO_RSTP:
1440 			bstp_timer_start(&bp->bp_tc_timer,
1441 			    bp->bp_desg_htime + BSTP_TICK_VAL);
1442 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1443 			break;
1444 
1445 		case BSTP_PROTO_STP:
1446 			bstp_timer_start(&bp->bp_tc_timer,
1447 			    bs->bs_root_max_age + bs->bs_root_fdelay);
1448 			break;
1449 	}
1450 }
1451 
1452 static void
1453 bstp_set_timer_msgage(struct bstp_port *bp)
1454 {
1455 	if (bp->bp_port_msg_age + BSTP_MESSAGE_AGE_INCR <=
1456 	    bp->bp_port_max_age) {
1457 		bstp_timer_start(&bp->bp_message_age_timer,
1458 		    bp->bp_port_htime * 3);
1459 	} else
1460 		/* expires immediately */
1461 		bstp_timer_start(&bp->bp_message_age_timer, 0);
1462 }
1463 
1464 static int
1465 bstp_rerooted(struct bstp_state *bs, struct bstp_port *bp)
1466 {
1467 	struct bstp_port *bp2;
1468 	int rr_set = 0;
1469 
1470 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1471 		if (bp2 == bp)
1472 			continue;
1473 		if (bp2->bp_recent_root_timer.active) {
1474 			rr_set = 1;
1475 			break;
1476 		}
1477 	}
1478 	return (!rr_set);
1479 }
1480 
1481 int
1482 bstp_set_htime(struct bstp_state *bs, int t)
1483 {
1484 	/* convert seconds to ticks */
1485 	t *=  BSTP_TICK_VAL;
1486 
1487 	/* value can only be changed in leagacy stp mode */
1488 	if (bs->bs_protover != BSTP_PROTO_STP)
1489 		return (EPERM);
1490 
1491 	if (t < BSTP_MIN_HELLO_TIME || t > BSTP_MAX_HELLO_TIME)
1492 		return (EINVAL);
1493 
1494 	BSTP_LOCK(bs);
1495 	bs->bs_bridge_htime = t;
1496 	bstp_reinit(bs);
1497 	BSTP_UNLOCK(bs);
1498 	return (0);
1499 }
1500 
1501 int
1502 bstp_set_fdelay(struct bstp_state *bs, int t)
1503 {
1504 	/* convert seconds to ticks */
1505 	t *= BSTP_TICK_VAL;
1506 
1507 	if (t < BSTP_MIN_FORWARD_DELAY || t > BSTP_MAX_FORWARD_DELAY)
1508 		return (EINVAL);
1509 
1510 	BSTP_LOCK(bs);
1511 	bs->bs_bridge_fdelay = t;
1512 	bstp_reinit(bs);
1513 	BSTP_UNLOCK(bs);
1514 	return (0);
1515 }
1516 
1517 int
1518 bstp_set_maxage(struct bstp_state *bs, int t)
1519 {
1520 	/* convert seconds to ticks */
1521 	t *= BSTP_TICK_VAL;
1522 
1523 	if (t < BSTP_MIN_MAX_AGE || t > BSTP_MAX_MAX_AGE)
1524 		return (EINVAL);
1525 
1526 	BSTP_LOCK(bs);
1527 	bs->bs_bridge_max_age = t;
1528 	bstp_reinit(bs);
1529 	BSTP_UNLOCK(bs);
1530 	return (0);
1531 }
1532 
1533 int
1534 bstp_set_holdcount(struct bstp_state *bs, int count)
1535 {
1536 	struct bstp_port *bp;
1537 
1538 	if (count < BSTP_MIN_HOLD_COUNT ||
1539 	    count > BSTP_MAX_HOLD_COUNT)
1540 		return (EINVAL);
1541 
1542 	BSTP_LOCK(bs);
1543 	bs->bs_txholdcount = count;
1544 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1545 		bp->bp_txcount = 0;
1546 	BSTP_UNLOCK(bs);
1547 	return (0);
1548 }
1549 
1550 int
1551 bstp_set_protocol(struct bstp_state *bs, int proto)
1552 {
1553 	struct bstp_port *bp;
1554 
1555 	switch (proto) {
1556 		/* Supported protocol versions */
1557 		case BSTP_PROTO_STP:
1558 		case BSTP_PROTO_RSTP:
1559 			break;
1560 
1561 		default:
1562 			return (EINVAL);
1563 	}
1564 
1565 	BSTP_LOCK(bs);
1566 	bs->bs_protover = proto;
1567 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
1568 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1569 		/* reinit state */
1570 		bp->bp_infois = BSTP_INFO_DISABLED;
1571 		bp->bp_txcount = 0;
1572 		bstp_set_port_proto(bp, bs->bs_protover);
1573 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
1574 		bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1575 		bstp_timer_stop(&bp->bp_recent_backup_timer);
1576 	}
1577 	bstp_reinit(bs);
1578 	BSTP_UNLOCK(bs);
1579 	return (0);
1580 }
1581 
1582 int
1583 bstp_set_priority(struct bstp_state *bs, int pri)
1584 {
1585 	if (pri < 0 || pri > BSTP_MAX_PRIORITY)
1586 		return (EINVAL);
1587 
1588 	/* Limit to steps of 4096 */
1589 	pri -= pri % 4096;
1590 
1591 	BSTP_LOCK(bs);
1592 	bs->bs_bridge_priority = pri;
1593 	bstp_reinit(bs);
1594 	BSTP_UNLOCK(bs);
1595 	return (0);
1596 }
1597 
1598 int
1599 bstp_set_port_priority(struct bstp_port *bp, int pri)
1600 {
1601 	struct bstp_state *bs = bp->bp_bs;
1602 
1603 	if (pri < 0 || pri > BSTP_MAX_PORT_PRIORITY)
1604 		return (EINVAL);
1605 
1606 	/* Limit to steps of 16 */
1607 	pri -= pri % 16;
1608 
1609 	BSTP_LOCK(bs);
1610 	bp->bp_priority = pri;
1611 	bstp_reinit(bs);
1612 	BSTP_UNLOCK(bs);
1613 	return (0);
1614 }
1615 
1616 int
1617 bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
1618 {
1619 	struct bstp_state *bs = bp->bp_bs;
1620 
1621 	if (path_cost > BSTP_MAX_PATH_COST)
1622 		return (EINVAL);
1623 
1624 	/* STP compat mode only uses 16 bits of the 32 */
1625 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1626 		path_cost = 65535;
1627 
1628 	BSTP_LOCK(bs);
1629 
1630 	if (path_cost == 0) {	/* use auto */
1631 		bp->bp_flags &= ~BSTP_PORT_ADMCOST;
1632 		bp->bp_path_cost = bstp_calc_path_cost(bp);
1633 	} else {
1634 		bp->bp_path_cost = path_cost;
1635 		bp->bp_flags |= BSTP_PORT_ADMCOST;
1636 	}
1637 	bstp_reinit(bs);
1638 	BSTP_UNLOCK(bs);
1639 	return (0);
1640 }
1641 
1642 int
1643 bstp_set_edge(struct bstp_port *bp, int set)
1644 {
1645 	struct bstp_state *bs = bp->bp_bs;
1646 
1647 	BSTP_LOCK(bs);
1648 	if ((bp->bp_operedge = set) == 0)
1649 		bp->bp_flags &= ~BSTP_PORT_ADMEDGE;
1650 	else
1651 		bp->bp_flags |= BSTP_PORT_ADMEDGE;
1652 	BSTP_UNLOCK(bs);
1653 	return (0);
1654 }
1655 
1656 int
1657 bstp_set_autoedge(struct bstp_port *bp, int set)
1658 {
1659 	struct bstp_state *bs = bp->bp_bs;
1660 
1661 	BSTP_LOCK(bs);
1662 	if (set) {
1663 		bp->bp_flags |= BSTP_PORT_AUTOEDGE;
1664 		/* we may be able to transition straight to edge */
1665 		if (bp->bp_edge_delay_timer.active == 0)
1666 			bstp_edge_delay_expiry(bs, bp);
1667 	} else
1668 		bp->bp_flags &= ~BSTP_PORT_AUTOEDGE;
1669 	BSTP_UNLOCK(bs);
1670 	return (0);
1671 }
1672 
1673 int
1674 bstp_set_ptp(struct bstp_port *bp, int set)
1675 {
1676 	struct bstp_state *bs = bp->bp_bs;
1677 
1678 	BSTP_LOCK(bs);
1679 	bp->bp_ptp_link = set;
1680 	BSTP_UNLOCK(bs);
1681 	return (0);
1682 }
1683 
1684 int
1685 bstp_set_autoptp(struct bstp_port *bp, int set)
1686 {
1687 	struct bstp_state *bs = bp->bp_bs;
1688 
1689 	BSTP_LOCK(bs);
1690 	if (set) {
1691 		bp->bp_flags |= BSTP_PORT_AUTOPTP;
1692 		if (bp->bp_role != BSTP_ROLE_DISABLED)
1693 			bstp_ifupdstatus(bs, bp);
1694 	} else
1695 		bp->bp_flags &= ~BSTP_PORT_AUTOPTP;
1696 	BSTP_UNLOCK(bs);
1697 	return (0);
1698 }
1699 
1700 /*
1701  * Calculate the path cost according to the link speed.
1702  */
1703 static uint32_t
1704 bstp_calc_path_cost(struct bstp_port *bp)
1705 {
1706 	struct ifnet *ifp = bp->bp_ifp;
1707 	uint32_t path_cost;
1708 
1709 	/* If the priority has been manually set then retain the value */
1710 	if (bp->bp_flags & BSTP_PORT_ADMCOST)
1711 		return bp->bp_path_cost;
1712 
1713 	if (ifp->if_link_state == LINK_STATE_DOWN) {
1714 		/* Recalc when the link comes up again */
1715 		bp->bp_flags |= BSTP_PORT_PNDCOST;
1716 		return (BSTP_DEFAULT_PATH_COST);
1717 	}
1718 
1719 	if (ifp->if_baudrate < 1000)
1720 		return (BSTP_DEFAULT_PATH_COST);
1721 
1722  	/* formula from section 17.14, IEEE Std 802.1D-2004 */
1723 	path_cost = 20000000000ULL / (ifp->if_baudrate / 1000);
1724 
1725 	if (path_cost > BSTP_MAX_PATH_COST)
1726 		path_cost = BSTP_MAX_PATH_COST;
1727 
1728 	/* STP compat mode only uses 16 bits of the 32 */
1729 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1730 		path_cost = 65535;
1731 
1732 	return (path_cost);
1733 }
1734 
1735 /*
1736  * Notify the bridge that a port state has changed, we need to do this from a
1737  * taskqueue to avoid a LOR.
1738  */
1739 static void
1740 bstp_notify_state(void *arg, int pending)
1741 {
1742 	struct bstp_port *bp = (struct bstp_port *)arg;
1743 	struct bstp_state *bs = bp->bp_bs;
1744 
1745 	if (bp->bp_active == 1 && bs->bs_state_cb != NULL)
1746 		(*bs->bs_state_cb)(bp->bp_ifp, bp->bp_state);
1747 }
1748 
1749 /*
1750  * Flush the routes on the bridge port, we need to do this from a
1751  * taskqueue to avoid a LOR.
1752  */
1753 static void
1754 bstp_notify_rtage(void *arg, int pending)
1755 {
1756 	struct bstp_port *bp = (struct bstp_port *)arg;
1757 	struct bstp_state *bs = bp->bp_bs;
1758 	int age = 0;
1759 
1760 	BSTP_LOCK(bs);
1761 	switch (bp->bp_protover) {
1762 		case BSTP_PROTO_STP:
1763 			/* convert to seconds */
1764 			age = bp->bp_desg_fdelay / BSTP_TICK_VAL;
1765 			break;
1766 
1767 		case BSTP_PROTO_RSTP:
1768 			age = 0;
1769 			break;
1770 	}
1771 	BSTP_UNLOCK(bs);
1772 
1773 	if (bp->bp_active == 1 && bs->bs_rtage_cb != NULL)
1774 		(*bs->bs_rtage_cb)(bp->bp_ifp, age);
1775 
1776 	/* flush is complete */
1777 	BSTP_LOCK(bs);
1778 	bp->bp_fdbflush = 0;
1779 	BSTP_UNLOCK(bs);
1780 }
1781 
1782 void
1783 bstp_linkstate(struct ifnet *ifp, int state)
1784 {
1785 	struct bstp_state *bs;
1786 	struct bstp_port *bp;
1787 
1788 	/* search for the stp port */
1789 	mtx_lock(&bstp_list_mtx);
1790 	LIST_FOREACH(bs, &bstp_list, bs_list) {
1791 		BSTP_LOCK(bs);
1792 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1793 			if (bp->bp_ifp == ifp) {
1794 				bstp_ifupdstatus(bs, bp);
1795 				bstp_update_state(bs, bp);
1796 				/* it only exists once so return */
1797 				BSTP_UNLOCK(bs);
1798 				mtx_unlock(&bstp_list_mtx);
1799 				return;
1800 			}
1801 		}
1802 		BSTP_UNLOCK(bs);
1803 	}
1804 	mtx_unlock(&bstp_list_mtx);
1805 }
1806 
1807 static void
1808 bstp_ifupdstatus(struct bstp_state *bs, struct bstp_port *bp)
1809 {
1810 	struct ifnet *ifp = bp->bp_ifp;
1811 	struct ifmediareq ifmr;
1812 	int error = 0;
1813 
1814 	BSTP_LOCK_ASSERT(bs);
1815 
1816 	bzero((char *)&ifmr, sizeof(ifmr));
1817 	error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);
1818 
1819 	if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1820 		if (ifmr.ifm_status & IFM_ACTIVE) {
1821 			/* A full-duplex link is assumed to be point to point */
1822 			if (bp->bp_flags & BSTP_PORT_AUTOPTP) {
1823 				bp->bp_ptp_link =
1824 				    ifmr.ifm_active & IFM_FDX ? 1 : 0;
1825 			}
1826 
1827 			/* Calc the cost if the link was down previously */
1828 			if (bp->bp_flags & BSTP_PORT_PNDCOST) {
1829 				bp->bp_path_cost = bstp_calc_path_cost(bp);
1830 				bp->bp_flags &= ~BSTP_PORT_PNDCOST;
1831 			}
1832 
1833 			if (bp->bp_role == BSTP_ROLE_DISABLED)
1834 				bstp_enable_port(bs, bp);
1835 		} else {
1836 			if (bp->bp_role != BSTP_ROLE_DISABLED) {
1837 				bstp_disable_port(bs, bp);
1838 				if ((bp->bp_flags & BSTP_PORT_ADMEDGE) &&
1839 				    bp->bp_protover == BSTP_PROTO_RSTP)
1840 					bp->bp_operedge = 1;
1841 			}
1842 		}
1843 		return;
1844 	}
1845 
1846 	if (bp->bp_infois != BSTP_INFO_DISABLED)
1847 		bstp_disable_port(bs, bp);
1848 }
1849 
1850 static void
1851 bstp_enable_port(struct bstp_state *bs, struct bstp_port *bp)
1852 {
1853 	bp->bp_infois = BSTP_INFO_AGED;
1854 	bstp_assign_roles(bs);
1855 }
1856 
1857 static void
1858 bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
1859 {
1860 	bp->bp_infois = BSTP_INFO_DISABLED;
1861 	bstp_assign_roles(bs);
1862 }
1863 
1864 static void
1865 bstp_tick(void *arg)
1866 {
1867 	struct bstp_state *bs = arg;
1868 	struct bstp_port *bp;
1869 
1870 	BSTP_LOCK_ASSERT(bs);
1871 
1872 	if (bs->bs_running == 0)
1873 		return;
1874 
1875 	/* slow timer to catch missed link events */
1876 	if (bstp_timer_expired(&bs->bs_link_timer)) {
1877 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1878 			bstp_ifupdstatus(bs, bp);
1879 		bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
1880 	}
1881 
1882 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1883 		/* no events need to happen for these */
1884 		bstp_timer_expired(&bp->bp_tc_timer);
1885 		bstp_timer_expired(&bp->bp_recent_root_timer);
1886 		bstp_timer_expired(&bp->bp_forward_delay_timer);
1887 		bstp_timer_expired(&bp->bp_recent_backup_timer);
1888 
1889 		if (bstp_timer_expired(&bp->bp_hello_timer))
1890 			bstp_hello_timer_expiry(bs, bp);
1891 
1892 		if (bstp_timer_expired(&bp->bp_message_age_timer))
1893 			bstp_message_age_expiry(bs, bp);
1894 
1895 		if (bstp_timer_expired(&bp->bp_migrate_delay_timer))
1896 			bstp_migrate_delay_expiry(bs, bp);
1897 
1898 		if (bstp_timer_expired(&bp->bp_edge_delay_timer))
1899 			bstp_edge_delay_expiry(bs, bp);
1900 
1901 		/* update the various state machines for the port */
1902 		bstp_update_state(bs, bp);
1903 
1904 		if (bp->bp_txcount > 0)
1905 			bp->bp_txcount--;
1906 	}
1907 
1908 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
1909 }
1910 
1911 static void
1912 bstp_timer_start(struct bstp_timer *t, uint16_t v)
1913 {
1914 	t->value = v;
1915 	t->active = 1;
1916 	t->latched = 0;
1917 }
1918 
1919 static void
1920 bstp_timer_stop(struct bstp_timer *t)
1921 {
1922 	t->value = 0;
1923 	t->active = 0;
1924 	t->latched = 0;
1925 }
1926 
1927 static void
1928 bstp_timer_latch(struct bstp_timer *t)
1929 {
1930 	t->latched = 1;
1931 	t->active = 1;
1932 }
1933 
1934 static int
1935 bstp_timer_expired(struct bstp_timer *t)
1936 {
1937 	if (t->active == 0 || t->latched)
1938 		return (0);
1939 	t->value -= BSTP_TICK_VAL;
1940 	if (t->value <= 0) {
1941 		bstp_timer_stop(t);
1942 		return (1);
1943 	}
1944 	return (0);
1945 }
1946 
1947 static void
1948 bstp_hello_timer_expiry(struct bstp_state *bs, struct bstp_port *bp)
1949 {
1950 	if ((bp->bp_flags & BSTP_PORT_NEWINFO) ||
1951 	    bp->bp_role == BSTP_ROLE_DESIGNATED ||
1952 	    (bp->bp_role == BSTP_ROLE_ROOT &&
1953 	     bp->bp_tc_timer.active == 1)) {
1954 		bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
1955 		bp->bp_flags |= BSTP_PORT_NEWINFO;
1956 		bstp_transmit(bs, bp);
1957 	}
1958 }
1959 
1960 static void
1961 bstp_message_age_expiry(struct bstp_state *bs, struct bstp_port *bp)
1962 {
1963 	if (bp->bp_infois == BSTP_INFO_RECEIVED) {
1964 		bp->bp_infois = BSTP_INFO_AGED;
1965 		bstp_assign_roles(bs);
1966 		DPRINTF("aged info on %s\n", bp->bp_ifp->if_xname);
1967 	}
1968 }
1969 
1970 static void
1971 bstp_migrate_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1972 {
1973 	bp->bp_flags |= BSTP_PORT_CANMIGRATE;
1974 }
1975 
1976 static void
1977 bstp_edge_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1978 {
1979 	if ((bp->bp_flags & BSTP_PORT_AUTOEDGE) &&
1980 	    bp->bp_protover == BSTP_PROTO_RSTP && bp->bp_proposing &&
1981 	    bp->bp_role == BSTP_ROLE_DESIGNATED) {
1982 		bp->bp_operedge = 1;
1983 		DPRINTF("%s -> edge port\n", bp->bp_ifp->if_xname);
1984 	}
1985 }
1986 
1987 static int
1988 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
1989 {
1990 	int i, d;
1991 
1992 	for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
1993 		d = ((int)a[i]) - ((int)b[i]);
1994 	}
1995 
1996 	return (d);
1997 }
1998 
1999 /*
2000  * compare the bridge address component of the bridgeid
2001  */
2002 static int
2003 bstp_same_bridgeid(uint64_t id1, uint64_t id2)
2004 {
2005 	u_char addr1[ETHER_ADDR_LEN];
2006 	u_char addr2[ETHER_ADDR_LEN];
2007 
2008 	PV2ADDR(id1, addr1);
2009 	PV2ADDR(id2, addr2);
2010 
2011 	if (bstp_addr_cmp(addr1, addr2) == 0)
2012 		return (1);
2013 
2014 	return (0);
2015 }
2016 
2017 void
2018 bstp_reinit(struct bstp_state *bs)
2019 {
2020 	INIT_VNET_NET(curvnet);
2021 	struct bstp_port *bp;
2022 	struct ifnet *ifp, *mif;
2023 	u_char *e_addr;
2024 	static const u_char llzero[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */
2025 
2026 	BSTP_LOCK_ASSERT(bs);
2027 
2028 	mif = NULL;
2029 	/*
2030 	 * Search through the Ethernet adapters and find the one with the
2031 	 * lowest value. The adapter which we take the MAC address from does
2032 	 * not need to be part of the bridge, it just needs to be a unique
2033 	 * value.
2034 	 */
2035 	IFNET_RLOCK();
2036 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2037 		if (ifp->if_type != IFT_ETHER)
2038 			continue;
2039 
2040 		if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
2041 			continue;
2042 
2043 		if (mif == NULL) {
2044 			mif = ifp;
2045 			continue;
2046 		}
2047 		if (bstp_addr_cmp(IF_LLADDR(ifp), IF_LLADDR(mif)) < 0) {
2048 			mif = ifp;
2049 			continue;
2050 		}
2051 	}
2052 	IFNET_RUNLOCK();
2053 
2054 	if (LIST_EMPTY(&bs->bs_bplist) || mif == NULL) {
2055 		/* Set the bridge and root id (lower bits) to zero */
2056 		bs->bs_bridge_pv.pv_dbridge_id =
2057 		    ((uint64_t)bs->bs_bridge_priority) << 48;
2058 		bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2059 		bs->bs_root_pv = bs->bs_bridge_pv;
2060 		/* Disable any remaining ports, they will have no MAC address */
2061 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2062 			bp->bp_infois = BSTP_INFO_DISABLED;
2063 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2064 		}
2065 		callout_stop(&bs->bs_bstpcallout);
2066 		return;
2067 	}
2068 
2069 	e_addr = IF_LLADDR(mif);
2070 	bs->bs_bridge_pv.pv_dbridge_id =
2071 	    (((uint64_t)bs->bs_bridge_priority) << 48) |
2072 	    (((uint64_t)e_addr[0]) << 40) |
2073 	    (((uint64_t)e_addr[1]) << 32) |
2074 	    (((uint64_t)e_addr[2]) << 24) |
2075 	    (((uint64_t)e_addr[3]) << 16) |
2076 	    (((uint64_t)e_addr[4]) << 8) |
2077 	    (((uint64_t)e_addr[5]));
2078 
2079 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
2080 	bs->bs_bridge_pv.pv_cost = 0;
2081 	bs->bs_bridge_pv.pv_dport_id = 0;
2082 	bs->bs_bridge_pv.pv_port_id = 0;
2083 
2084 	if (bs->bs_running && callout_pending(&bs->bs_bstpcallout) == 0)
2085 		callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2086 
2087 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
2088 		bp->bp_port_id = (bp->bp_priority << 8) |
2089 		    (bp->bp_ifp->if_index  & 0xfff);
2090 		bstp_ifupdstatus(bs, bp);
2091 	}
2092 
2093 	bstp_assign_roles(bs);
2094 	bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
2095 }
2096 
2097 static int
2098 bstp_modevent(module_t mod, int type, void *data)
2099 {
2100 	switch (type) {
2101 	case MOD_LOAD:
2102 		mtx_init(&bstp_list_mtx, "bridgestp list", NULL, MTX_DEF);
2103 		LIST_INIT(&bstp_list);
2104 		bstp_linkstate_p = bstp_linkstate;
2105 		break;
2106 	case MOD_UNLOAD:
2107 		bstp_linkstate_p = NULL;
2108 		mtx_destroy(&bstp_list_mtx);
2109 		break;
2110 	default:
2111 		return (EOPNOTSUPP);
2112 	}
2113 	return (0);
2114 }
2115 
2116 static moduledata_t bstp_mod = {
2117 	"bridgestp",
2118 	bstp_modevent,
2119 	0
2120 };
2121 
2122 DECLARE_MODULE(bridgestp, bstp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2123 MODULE_VERSION(bridgestp, 1);
2124 
2125 void
2126 bstp_attach(struct bstp_state *bs, struct bstp_cb_ops *cb)
2127 {
2128 	BSTP_LOCK_INIT(bs);
2129 	callout_init_mtx(&bs->bs_bstpcallout, &bs->bs_mtx, 0);
2130 	LIST_INIT(&bs->bs_bplist);
2131 
2132 	bs->bs_bridge_max_age = BSTP_DEFAULT_MAX_AGE;
2133 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
2134 	bs->bs_bridge_fdelay = BSTP_DEFAULT_FORWARD_DELAY;
2135 	bs->bs_bridge_priority = BSTP_DEFAULT_BRIDGE_PRIORITY;
2136 	bs->bs_hold_time = BSTP_DEFAULT_HOLD_TIME;
2137 	bs->bs_migration_delay = BSTP_DEFAULT_MIGRATE_DELAY;
2138 	bs->bs_txholdcount = BSTP_DEFAULT_HOLD_COUNT;
2139 	bs->bs_protover = BSTP_PROTO_RSTP;
2140 	bs->bs_state_cb = cb->bcb_state;
2141 	bs->bs_rtage_cb = cb->bcb_rtage;
2142 
2143 	getmicrotime(&bs->bs_last_tc_time);
2144 
2145 	mtx_lock(&bstp_list_mtx);
2146 	LIST_INSERT_HEAD(&bstp_list, bs, bs_list);
2147 	mtx_unlock(&bstp_list_mtx);
2148 }
2149 
2150 void
2151 bstp_detach(struct bstp_state *bs)
2152 {
2153 	KASSERT(LIST_EMPTY(&bs->bs_bplist), ("bstp still active"));
2154 
2155 	mtx_lock(&bstp_list_mtx);
2156 	LIST_REMOVE(bs, bs_list);
2157 	mtx_unlock(&bstp_list_mtx);
2158 	callout_drain(&bs->bs_bstpcallout);
2159 	BSTP_LOCK_DESTROY(bs);
2160 }
2161 
2162 void
2163 bstp_init(struct bstp_state *bs)
2164 {
2165 	BSTP_LOCK(bs);
2166 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2167 	bs->bs_running = 1;
2168 	bstp_reinit(bs);
2169 	BSTP_UNLOCK(bs);
2170 }
2171 
2172 void
2173 bstp_stop(struct bstp_state *bs)
2174 {
2175 	struct bstp_port *bp;
2176 
2177 	BSTP_LOCK(bs);
2178 
2179 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
2180 		bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2181 
2182 	bs->bs_running = 0;
2183 	callout_stop(&bs->bs_bstpcallout);
2184 	BSTP_UNLOCK(bs);
2185 }
2186 
2187 int
2188 bstp_create(struct bstp_state *bs, struct bstp_port *bp, struct ifnet *ifp)
2189 {
2190 	bzero(bp, sizeof(struct bstp_port));
2191 
2192 	BSTP_LOCK(bs);
2193 	bp->bp_ifp = ifp;
2194 	bp->bp_bs = bs;
2195 	bp->bp_priority = BSTP_DEFAULT_PORT_PRIORITY;
2196 	TASK_INIT(&bp->bp_statetask, 0, bstp_notify_state, bp);
2197 	TASK_INIT(&bp->bp_rtagetask, 0, bstp_notify_rtage, bp);
2198 
2199 	/* Init state */
2200 	bp->bp_infois = BSTP_INFO_DISABLED;
2201 	bp->bp_flags = BSTP_PORT_AUTOEDGE|BSTP_PORT_AUTOPTP;
2202 	bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2203 	bstp_set_port_proto(bp, bs->bs_protover);
2204 	bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2205 	bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
2206 	bp->bp_path_cost = bstp_calc_path_cost(bp);
2207 	BSTP_UNLOCK(bs);
2208 	return (0);
2209 }
2210 
2211 int
2212 bstp_enable(struct bstp_port *bp)
2213 {
2214 	struct bstp_state *bs = bp->bp_bs;
2215 	struct ifnet *ifp = bp->bp_ifp;
2216 
2217 	KASSERT(bp->bp_active == 0, ("already a bstp member"));
2218 
2219 	switch (ifp->if_type) {
2220 		case IFT_ETHER:	/* These can do spanning tree. */
2221 			break;
2222 		default:
2223 			/* Nothing else can. */
2224 			return (EINVAL);
2225 	}
2226 
2227 	BSTP_LOCK(bs);
2228 	LIST_INSERT_HEAD(&bs->bs_bplist, bp, bp_next);
2229 	bp->bp_active = 1;
2230 	bp->bp_flags |= BSTP_PORT_NEWINFO;
2231 	bstp_reinit(bs);
2232 	bstp_update_roles(bs, bp);
2233 	BSTP_UNLOCK(bs);
2234 	return (0);
2235 }
2236 
2237 void
2238 bstp_disable(struct bstp_port *bp)
2239 {
2240 	struct bstp_state *bs = bp->bp_bs;
2241 
2242 	KASSERT(bp->bp_active == 1, ("not a bstp member"));
2243 
2244 	BSTP_LOCK(bs);
2245 	bstp_disable_port(bs, bp);
2246 	LIST_REMOVE(bp, bp_next);
2247 	bp->bp_active = 0;
2248 	bstp_reinit(bs);
2249 	BSTP_UNLOCK(bs);
2250 }
2251 
2252 /*
2253  * The bstp_port structure is about to be freed by the parent bridge.
2254  */
2255 void
2256 bstp_destroy(struct bstp_port *bp)
2257 {
2258 	KASSERT(bp->bp_active == 0, ("port is still attached"));
2259 	taskqueue_drain(taskqueue_swi, &bp->bp_statetask);
2260 	taskqueue_drain(taskqueue_swi, &bp->bp_rtagetask);
2261 }
2262