xref: /freebsd/sys/net/bridgestp.c (revision acd3428b7d3e94cef0e1881c868cb4b131d4ff41)
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 
53 #include <net/if.h>
54 #include <net/if_dl.h>
55 #include <net/if_types.h>
56 #include <net/if_llc.h>
57 #include <net/if_media.h>
58 
59 #include <netinet/in.h>
60 #include <netinet/in_systm.h>
61 #include <netinet/in_var.h>
62 #include <netinet/if_ether.h>
63 #include <net/bridgestp.h>
64 
65 #ifdef	BRIDGESTP_DEBUG
66 #define	DPRINTF(fmt, arg...)	printf("bstp: " fmt, ##arg)
67 #else
68 #define	DPRINTF(fmt, arg...)
69 #endif
70 
71 #define	PV2ADDR(pv, eaddr)	do {		\
72 	eaddr[0] = pv >> 40;			\
73 	eaddr[1] = pv >> 32;			\
74 	eaddr[2] = pv >> 24;			\
75 	eaddr[3] = pv >> 16;			\
76 	eaddr[4] = pv >> 8;			\
77 	eaddr[5] = pv >> 0;			\
78 } while (0)
79 
80 #define	INFO_BETTER	1
81 #define	INFO_SAME	0
82 #define	INFO_WORSE	-1
83 
84 const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
85 
86 LIST_HEAD(, bstp_state) bstp_list;
87 static struct mtx	bstp_list_mtx;
88 
89 static void	bstp_transmit(struct bstp_state *, struct bstp_port *);
90 static void	bstp_transmit_bpdu(struct bstp_state *, struct bstp_port *);
91 static void	bstp_transmit_tcn(struct bstp_state *, struct bstp_port *);
92 static void	bstp_decode_bpdu(struct bstp_port *, struct bstp_cbpdu *,
93 		    struct bstp_config_unit *);
94 static void	bstp_send_bpdu(struct bstp_state *, struct bstp_port *,
95 		    struct bstp_cbpdu *);
96 static void	bstp_enqueue(struct ifnet *, struct mbuf *);
97 static int	bstp_pdu_flags(struct bstp_port *);
98 static void	bstp_received_stp(struct bstp_state *, struct bstp_port *,
99 		    struct mbuf **, struct bstp_tbpdu *);
100 static void	bstp_received_rstp(struct bstp_state *, struct bstp_port *,
101 		    struct mbuf **, struct bstp_tbpdu *);
102 static void	bstp_received_tcn(struct bstp_state *, struct bstp_port *,
103 		    struct bstp_tcn_unit *);
104 static void	bstp_received_bpdu(struct bstp_state *, struct bstp_port *,
105 		    struct bstp_config_unit *);
106 static int	bstp_pdu_rcvtype(struct bstp_port *, struct bstp_config_unit *);
107 static int	bstp_pdu_bettersame(struct bstp_port *, int);
108 static int	bstp_info_cmp(struct bstp_pri_vector *,
109 		    struct bstp_pri_vector *);
110 static int	bstp_info_superior(struct bstp_pri_vector *,
111 		    struct bstp_pri_vector *);
112 static void	bstp_assign_roles(struct bstp_state *);
113 static void	bstp_update_roles(struct bstp_state *, struct bstp_port *);
114 static void	bstp_update_state(struct bstp_state *, struct bstp_port *);
115 static void	bstp_update_tc(struct bstp_port *);
116 static void	bstp_update_info(struct bstp_port *);
117 static void	bstp_set_other_tcprop(struct bstp_port *);
118 static void	bstp_set_all_reroot(struct bstp_state *);
119 static void	bstp_set_all_sync(struct bstp_state *);
120 static void	bstp_set_port_state(struct bstp_port *, int);
121 static void	bstp_set_port_role(struct bstp_port *, int);
122 static void	bstp_set_port_proto(struct bstp_port *, int);
123 static void	bstp_set_port_tc(struct bstp_port *, int);
124 static void	bstp_set_timer_tc(struct bstp_port *);
125 static void	bstp_set_timer_msgage(struct bstp_port *);
126 static int	bstp_rerooted(struct bstp_state *, struct bstp_port *);
127 static uint32_t	bstp_calc_path_cost(struct bstp_port *);
128 static void	bstp_notify_state(void *, int);
129 static void	bstp_notify_rtage(void *, int);
130 static void	bstp_ifupdstatus(struct bstp_state *, struct bstp_port *);
131 static void	bstp_enable_port(struct bstp_state *, struct bstp_port *);
132 static void	bstp_disable_port(struct bstp_state *, struct bstp_port *);
133 static void	bstp_tick(void *);
134 static void	bstp_timer_start(struct bstp_timer *, uint16_t);
135 static void	bstp_timer_stop(struct bstp_timer *);
136 static void	bstp_timer_latch(struct bstp_timer *);
137 static int	bstp_timer_expired(struct bstp_timer *);
138 static void	bstp_hello_timer_expiry(struct bstp_state *,
139 		    struct bstp_port *);
140 static void	bstp_message_age_expiry(struct bstp_state *,
141 		    struct bstp_port *);
142 static void	bstp_migrate_delay_expiry(struct bstp_state *,
143 		    struct bstp_port *);
144 static void	bstp_edge_delay_expiry(struct bstp_state *,
145 		    struct bstp_port *);
146 static int	bstp_addr_cmp(const uint8_t *, const uint8_t *);
147 static int	bstp_same_bridgeid(uint64_t, uint64_t);
148 static void	bstp_reinit(struct bstp_state *);
149 static void	bstp_stop_locked(struct bstp_state *);
150 
151 static void
152 bstp_transmit(struct bstp_state *bs, struct bstp_port *bp)
153 {
154 	/*
155 	 * a PDU can only be sent if we have tx quota left and the
156 	 * hello timer is running.
157 	 */
158 	if (bp->bp_hello_timer.active == 0) {
159 		/* Test if it needs to be reset */
160 		bstp_hello_timer_expiry(bs, bp);
161 		return;
162 	}
163 	if (bp->bp_txcount > bs->bs_txholdcount)
164 		/* Ran out of karma */
165 		return;
166 
167 	if (bp->bp_protover == BSTP_PROTO_RSTP) {
168 		bstp_transmit_bpdu(bs, bp);
169 		bp->bp_tc_ack = 0;
170 	} else { /* STP */
171 		switch (bp->bp_role) {
172 			case BSTP_ROLE_DESIGNATED:
173 				bstp_transmit_bpdu(bs, bp);
174 				bp->bp_tc_ack = 0;
175 				break;
176 
177 			case BSTP_ROLE_ROOT:
178 				bstp_transmit_tcn(bs, bp);
179 				break;
180 		}
181 	}
182 	bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
183 	bp->bp_flags &= ~BSTP_PORT_NEWINFO;
184 }
185 
186 static void
187 bstp_transmit_bpdu(struct bstp_state *bs, struct bstp_port *bp)
188 {
189 	struct bstp_cbpdu bpdu;
190 
191 	BSTP_LOCK_ASSERT(bs);
192 
193 	bpdu.cbu_rootpri = htons(bp->bp_desg_pv.pv_root_id >> 48);
194 	PV2ADDR(bp->bp_desg_pv.pv_root_id, bpdu.cbu_rootaddr);
195 
196 	bpdu.cbu_rootpathcost = htonl(bp->bp_desg_pv.pv_cost);
197 
198 	bpdu.cbu_bridgepri = htons(bp->bp_desg_pv.pv_dbridge_id >> 48);
199 	PV2ADDR(bp->bp_desg_pv.pv_dbridge_id, bpdu.cbu_bridgeaddr);
200 
201 	bpdu.cbu_portid = htons(bp->bp_port_id);
202 	bpdu.cbu_messageage = htons(bp->bp_desg_msg_age);
203 	bpdu.cbu_maxage = htons(bp->bp_desg_max_age);
204 	bpdu.cbu_hellotime = htons(bp->bp_desg_htime);
205 	bpdu.cbu_forwarddelay = htons(bp->bp_desg_fdelay);
206 
207 	bpdu.cbu_flags = bstp_pdu_flags(bp);
208 
209 	switch (bp->bp_protover) {
210 		case BSTP_PROTO_STP:
211 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_CFG;
212 			break;
213 
214 		case BSTP_PROTO_RSTP:
215 			bpdu.cbu_bpdutype = BSTP_MSGTYPE_RSTP;
216 			break;
217 	}
218 
219 	bstp_send_bpdu(bs, bp, &bpdu);
220 }
221 
222 static void
223 bstp_transmit_tcn(struct bstp_state *bs, struct bstp_port *bp)
224 {
225 	struct bstp_tbpdu bpdu;
226 	struct ifnet *ifp = bp->bp_ifp;
227 	struct ether_header *eh;
228 	struct mbuf *m;
229 
230 	KASSERT(bp == bs->bs_root_port, ("%s: bad root port\n", __func__));
231 
232 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
233 		return;
234 
235 	MGETHDR(m, M_DONTWAIT, MT_DATA);
236 	if (m == NULL)
237 		return;
238 
239 	m->m_pkthdr.rcvif = ifp;
240 	m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
241 	m->m_len = m->m_pkthdr.len;
242 
243 	eh = mtod(m, struct ether_header *);
244 
245 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
246 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
247 	eh->ether_type = htons(sizeof(bpdu));
248 
249 	bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
250 	bpdu.tbu_ctl = LLC_UI;
251 	bpdu.tbu_protoid = 0;
252 	bpdu.tbu_protover = 0;
253 	bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
254 
255 	memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
256 
257 	bp->bp_txcount++;
258 	bstp_enqueue(ifp, m);
259 }
260 
261 static void
262 bstp_decode_bpdu(struct bstp_port *bp, struct bstp_cbpdu *cpdu,
263     struct bstp_config_unit *cu)
264 {
265 	int flags;
266 
267 	cu->cu_pv.pv_root_id =
268 	    (((uint64_t)ntohs(cpdu->cbu_rootpri)) << 48) |
269 	    (((uint64_t)cpdu->cbu_rootaddr[0]) << 40) |
270 	    (((uint64_t)cpdu->cbu_rootaddr[1]) << 32) |
271 	    (((uint64_t)cpdu->cbu_rootaddr[2]) << 24) |
272 	    (((uint64_t)cpdu->cbu_rootaddr[3]) << 16) |
273 	    (((uint64_t)cpdu->cbu_rootaddr[4]) << 8) |
274 	    (((uint64_t)cpdu->cbu_rootaddr[5]) << 0);
275 
276 	cu->cu_pv.pv_dbridge_id =
277 	    (((uint64_t)ntohs(cpdu->cbu_bridgepri)) << 48) |
278 	    (((uint64_t)cpdu->cbu_bridgeaddr[0]) << 40) |
279 	    (((uint64_t)cpdu->cbu_bridgeaddr[1]) << 32) |
280 	    (((uint64_t)cpdu->cbu_bridgeaddr[2]) << 24) |
281 	    (((uint64_t)cpdu->cbu_bridgeaddr[3]) << 16) |
282 	    (((uint64_t)cpdu->cbu_bridgeaddr[4]) << 8) |
283 	    (((uint64_t)cpdu->cbu_bridgeaddr[5]) << 0);
284 
285 	cu->cu_pv.pv_cost = ntohl(cpdu->cbu_rootpathcost);
286 	cu->cu_message_age = ntohs(cpdu->cbu_messageage);
287 	cu->cu_max_age = ntohs(cpdu->cbu_maxage);
288 	cu->cu_hello_time = ntohs(cpdu->cbu_hellotime);
289 	cu->cu_forward_delay = ntohs(cpdu->cbu_forwarddelay);
290 	cu->cu_pv.pv_dport_id = ntohs(cpdu->cbu_portid);
291 	cu->cu_pv.pv_port_id = bp->bp_port_id;
292 	cu->cu_message_type = cpdu->cbu_bpdutype;
293 
294 	/* Strip off unused flags in STP mode */
295 	flags = cpdu->cbu_flags;
296 	switch (cpdu->cbu_protover) {
297 		case BSTP_PROTO_STP:
298 			flags &= BSTP_PDU_STPMASK;
299 			/* A STP BPDU explicitly conveys a Designated Port */
300 			cu->cu_role = BSTP_ROLE_DESIGNATED;
301 			break;
302 
303 		case BSTP_PROTO_RSTP:
304 			flags &= BSTP_PDU_RSTPMASK;
305 			break;
306 	}
307 
308 	cu->cu_topology_change_ack =
309 		(flags & BSTP_PDU_F_TCA) ? 1 : 0;
310 	cu->cu_proposal =
311 		(flags & BSTP_PDU_F_P) ? 1 : 0;
312 	cu->cu_agree =
313 		(flags & BSTP_PDU_F_A) ? 1 : 0;
314 	cu->cu_learning =
315 		(flags & BSTP_PDU_F_L) ? 1 : 0;
316 	cu->cu_forwarding =
317 		(flags & BSTP_PDU_F_F) ? 1 : 0;
318 	cu->cu_topology_change =
319 		(flags & BSTP_PDU_F_TC) ? 1 : 0;
320 
321 	switch ((flags & BSTP_PDU_PRMASK) >> BSTP_PDU_PRSHIFT) {
322 		case BSTP_PDU_F_ROOT:
323 			cu->cu_role = BSTP_ROLE_ROOT;
324 			break;
325 		case BSTP_PDU_F_ALT:
326 			cu->cu_role = BSTP_ROLE_ALTERNATE;
327 			break;
328 		case BSTP_PDU_F_DESG:
329 			cu->cu_role = BSTP_ROLE_DESIGNATED;
330 			break;
331 	}
332 }
333 
334 static void
335 bstp_send_bpdu(struct bstp_state *bs, struct bstp_port *bp,
336     struct bstp_cbpdu *bpdu)
337 {
338 	struct ifnet *ifp;
339 	struct mbuf *m;
340 	struct ether_header *eh;
341 
342 	BSTP_LOCK_ASSERT(bs);
343 
344 	ifp = bp->bp_ifp;
345 
346 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
347 		return;
348 
349 	MGETHDR(m, M_DONTWAIT, MT_DATA);
350 	if (m == NULL)
351 		return;
352 
353 	eh = mtod(m, struct ether_header *);
354 
355 	bpdu->cbu_ssap = bpdu->cbu_dsap = LLC_8021D_LSAP;
356 	bpdu->cbu_ctl = LLC_UI;
357 	bpdu->cbu_protoid = htons(BSTP_PROTO_ID);
358 
359 	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
360 	memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
361 
362 	switch (bpdu->cbu_bpdutype) {
363 		case BSTP_MSGTYPE_CFG:
364 			bpdu->cbu_protover = BSTP_PROTO_STP;
365 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_STP_LEN;
366 			eh->ether_type = htons(BSTP_BPDU_STP_LEN);
367 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
368 			    BSTP_BPDU_STP_LEN);
369 			break;
370 
371 		case BSTP_MSGTYPE_RSTP:
372 			bpdu->cbu_protover = BSTP_PROTO_RSTP;
373 			bpdu->cbu_versionlen = htons(0);
374 			m->m_pkthdr.len = sizeof(*eh) + BSTP_BPDU_RSTP_LEN;
375 			eh->ether_type = htons(BSTP_BPDU_RSTP_LEN);
376 			memcpy(mtod(m, caddr_t) + sizeof(*eh), bpdu,
377 			    BSTP_BPDU_RSTP_LEN);
378 			break;
379 
380 		default:
381 			panic("not implemented");
382 	}
383 	m->m_pkthdr.rcvif = ifp;
384 	m->m_len = m->m_pkthdr.len;
385 
386 	bp->bp_txcount++;
387 	bstp_enqueue(ifp, m);
388 }
389 
390 static void
391 bstp_enqueue(struct ifnet *dst_ifp, struct mbuf *m)
392 {
393 	int err = 0;
394 
395 	IFQ_ENQUEUE(&dst_ifp->if_snd, m, err);
396 
397 	if ((dst_ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0)
398 		(*dst_ifp->if_start)(dst_ifp);
399 }
400 
401 static int
402 bstp_pdu_flags(struct bstp_port *bp)
403 {
404 	int flags = 0;
405 
406 	if (bp->bp_proposing && bp->bp_state != BSTP_IFSTATE_FORWARDING)
407 		flags |= BSTP_PDU_F_P;
408 
409 	if (bp->bp_agree)
410 		flags |= BSTP_PDU_F_A;
411 
412 	if (bp->bp_tc_timer.active)
413 		flags |= BSTP_PDU_F_TC;
414 
415 	if (bp->bp_tc_ack)
416 		flags |= BSTP_PDU_F_TCA;
417 
418 	switch (bp->bp_state) {
419 		case BSTP_IFSTATE_LEARNING:
420 			flags |= BSTP_PDU_F_L;
421 			break;
422 
423 		case BSTP_IFSTATE_FORWARDING:
424 			flags |= (BSTP_PDU_F_L | BSTP_PDU_F_F);
425 			break;
426 	}
427 
428 	switch (bp->bp_role) {
429 		case BSTP_ROLE_ROOT:
430 			flags |=
431 				(BSTP_PDU_F_ROOT << BSTP_PDU_PRSHIFT);
432 			break;
433 
434 		case BSTP_ROLE_ALTERNATE:
435 		case BSTP_ROLE_BACKUP:	/* fall through */
436 			flags |=
437 				(BSTP_PDU_F_ALT << BSTP_PDU_PRSHIFT);
438 			break;
439 
440 		case BSTP_ROLE_DESIGNATED:
441 			flags |=
442 				(BSTP_PDU_F_DESG << BSTP_PDU_PRSHIFT);
443 			break;
444 	}
445 
446 	/* Strip off unused flags in either mode */
447 	switch (bp->bp_protover) {
448 		case BSTP_PROTO_STP:
449 			flags &= BSTP_PDU_STPMASK;
450 			break;
451 		case BSTP_PROTO_RSTP:
452 			flags &= BSTP_PDU_RSTPMASK;
453 			break;
454 	}
455 	return (flags);
456 }
457 
458 struct mbuf *
459 bstp_input(struct bstp_port *bp, struct ifnet *ifp, struct mbuf *m)
460 {
461 	struct bstp_state *bs = bp->bp_bs;
462 	struct ether_header *eh;
463 	struct bstp_tbpdu tpdu;
464 	uint16_t len;
465 
466 	if (bp->bp_active == 0) {
467 		m_freem(m);
468 		return (NULL);
469 	}
470 
471 	BSTP_LOCK(bs);
472 
473 	eh = mtod(m, struct ether_header *);
474 
475 	len = ntohs(eh->ether_type);
476 	if (len < sizeof(tpdu))
477 		goto out;
478 
479 	m_adj(m, ETHER_HDR_LEN);
480 
481 	if (m->m_pkthdr.len > len)
482 		m_adj(m, len - m->m_pkthdr.len);
483 	if (m->m_len < sizeof(tpdu) &&
484 	    (m = m_pullup(m, sizeof(tpdu))) == NULL)
485 		goto out;
486 
487 	memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
488 
489 	/* basic packet checks */
490 	if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
491 	    tpdu.tbu_ssap != LLC_8021D_LSAP ||
492 	    tpdu.tbu_ctl != LLC_UI)
493 		goto out;
494 	if (tpdu.tbu_protoid != BSTP_PROTO_ID)
495 		goto out;
496 
497 	/*
498 	 * We can treat later versions of the PDU as the same as the maximum
499 	 * version we implement. All additional parameters/flags are ignored.
500 	 */
501 	if (tpdu.tbu_protover > BSTP_PROTO_MAX)
502 		tpdu.tbu_protover = BSTP_PROTO_MAX;
503 
504 	if (tpdu.tbu_protover != bp->bp_protover) {
505 		/*
506 		 * Wait for the migration delay timer to expire before changing
507 		 * protocol version to avoid flip-flops.
508 		 */
509 		if (bp->bp_flags & BSTP_PORT_CANMIGRATE)
510 			bstp_set_port_proto(bp, tpdu.tbu_protover);
511 		else
512 			goto out;
513 	}
514 
515 	/* Clear operedge upon receiving a PDU on the port */
516 	bp->bp_operedge = 0;
517 	bstp_timer_start(&bp->bp_edge_delay_timer,
518 	    BSTP_DEFAULT_MIGRATE_DELAY);
519 
520 	switch (tpdu.tbu_protover) {
521 		case BSTP_PROTO_STP:
522 			bstp_received_stp(bs, bp, &m, &tpdu);
523 			break;
524 
525 		case BSTP_PROTO_RSTP:
526 			bstp_received_rstp(bs, bp, &m, &tpdu);
527 			break;
528 	}
529 out:
530 	BSTP_UNLOCK(bs);
531 	if (m)
532 		m_freem(m);
533 	return (NULL);
534 }
535 
536 static void
537 bstp_received_stp(struct bstp_state *bs, struct bstp_port *bp,
538     struct mbuf **mp, struct bstp_tbpdu *tpdu)
539 {
540 	struct bstp_cbpdu cpdu;
541 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
542 	struct bstp_tcn_unit tu;
543 
544 	switch (tpdu->tbu_bpdutype) {
545 	case BSTP_MSGTYPE_TCN:
546 		tu.tu_message_type = tpdu->tbu_bpdutype;
547 		bstp_received_tcn(bs, bp, &tu);
548 		break;
549 	case BSTP_MSGTYPE_CFG:
550 		if ((*mp)->m_len < BSTP_BPDU_STP_LEN &&
551 		    (*mp = m_pullup(*mp, BSTP_BPDU_STP_LEN)) == NULL)
552 			return;
553 		memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_STP_LEN);
554 
555 		bstp_decode_bpdu(bp, &cpdu, cu);
556 		bstp_received_bpdu(bs, bp, cu);
557 		break;
558 	}
559 }
560 
561 static void
562 bstp_received_rstp(struct bstp_state *bs, struct bstp_port *bp,
563     struct mbuf **mp, struct bstp_tbpdu *tpdu)
564 {
565 	struct bstp_cbpdu cpdu;
566 	struct bstp_config_unit *cu = &bp->bp_msg_cu;
567 
568 	if (tpdu->tbu_bpdutype != BSTP_MSGTYPE_RSTP)
569 		return;
570 
571 	if ((*mp)->m_len < BSTP_BPDU_RSTP_LEN &&
572 	    (*mp = m_pullup(*mp, BSTP_BPDU_RSTP_LEN)) == NULL)
573 		return;
574 	memcpy(&cpdu, mtod(*mp, caddr_t), BSTP_BPDU_RSTP_LEN);
575 
576 	bstp_decode_bpdu(bp, &cpdu, cu);
577 	bstp_received_bpdu(bs, bp, cu);
578 }
579 
580 static void
581 bstp_received_tcn(struct bstp_state *bs, struct bstp_port *bp,
582     struct bstp_tcn_unit *tcn)
583 {
584 	bp->bp_rcvdtcn = 1;
585 	bstp_update_tc(bp);
586 }
587 
588 static void
589 bstp_received_bpdu(struct bstp_state *bs, struct bstp_port *bp,
590     struct bstp_config_unit *cu)
591 {
592 	int type;
593 
594 	BSTP_LOCK_ASSERT(bs);
595 
596 	/* We need to have transitioned to INFO_MINE before proceeding */
597 	switch (bp->bp_infois) {
598 		case BSTP_INFO_DISABLED:
599 		case BSTP_INFO_AGED:
600 			return;
601 	}
602 
603 	type = bstp_pdu_rcvtype(bp, cu);
604 
605 	switch (type) {
606 		case BSTP_PDU_SUPERIOR:
607 			bs->bs_allsynced = 0;
608 			bp->bp_agreed = 0;
609 			bp->bp_proposing = 0;
610 
611 			if (cu->cu_proposal && cu->cu_forwarding == 0)
612 				bp->bp_proposed = 1;
613 			if (cu->cu_topology_change)
614 				bp->bp_rcvdtc = 1;
615 			if (cu->cu_topology_change_ack)
616 				bp->bp_rcvdtca = 1;
617 
618 			if (bp->bp_agree &&
619 			    !bstp_pdu_bettersame(bp, BSTP_INFO_RECIEVED))
620 				bp->bp_agree = 0;
621 
622 			/* copy the received priority and timers to the port */
623 			bp->bp_port_pv = cu->cu_pv;
624 			bp->bp_port_msg_age = cu->cu_message_age;
625 			bp->bp_port_max_age = cu->cu_max_age;
626 			bp->bp_port_fdelay = cu->cu_forward_delay;
627 			bp->bp_port_htime =
628 				(cu->cu_hello_time > BSTP_MIN_HELLO_TIME ?
629 				 cu->cu_hello_time : BSTP_MIN_HELLO_TIME);
630 
631 			/* set expiry for the new info */
632 			bstp_set_timer_msgage(bp);
633 
634 			bp->bp_infois = BSTP_INFO_RECIEVED;
635 			bstp_assign_roles(bs);
636 			break;
637 
638 		case BSTP_PDU_REPEATED:
639 			if (cu->cu_proposal && cu->cu_forwarding == 0)
640 				bp->bp_proposed = 1;
641 			if (cu->cu_topology_change)
642 				bp->bp_rcvdtc = 1;
643 			if (cu->cu_topology_change_ack)
644 				bp->bp_rcvdtca = 1;
645 
646 			/* rearm the age timer */
647 			bstp_set_timer_msgage(bp);
648 			break;
649 
650 		case BSTP_PDU_INFERIOR:
651 			if (cu->cu_learning) {
652 				bp->bp_agreed = 1;
653 				bp->bp_proposing = 0;
654 			}
655 			break;
656 
657 		case BSTP_PDU_INFERIORALT:
658 			/*
659 			 * only point to point links are allowed fast
660 			 * transitions to forwarding.
661 			 */
662 			if (cu->cu_agree && bp->bp_p2p_link) {
663 				bp->bp_agreed = 1;
664 				bp->bp_proposing = 0;
665 			} else
666 				bp->bp_agreed = 0;
667 
668 			if (cu->cu_topology_change)
669 				bp->bp_rcvdtc = 1;
670 			if (cu->cu_topology_change_ack)
671 				bp->bp_rcvdtca = 1;
672 			break;
673 
674 		case BSTP_PDU_OTHER:
675 			return;	/* do nothing */
676 	}
677 	/* update the state machines with the new data */
678 	bstp_update_state(bs, bp);
679 }
680 
681 static int
682 bstp_pdu_rcvtype(struct bstp_port *bp, struct bstp_config_unit *cu)
683 {
684 	int type;
685 
686 	/* default return type */
687 	type = BSTP_PDU_OTHER;
688 
689 	switch (cu->cu_role) {
690 	case BSTP_ROLE_DESIGNATED:
691 		if (bstp_info_superior(&bp->bp_port_pv, &cu->cu_pv))
692 			/* bpdu priority is superior */
693 			type = BSTP_PDU_SUPERIOR;
694 		else if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) ==
695 		    INFO_SAME) {
696 			if (bp->bp_port_msg_age != cu->cu_message_age ||
697 			    bp->bp_port_max_age != cu->cu_max_age ||
698 			    bp->bp_port_fdelay != cu->cu_forward_delay ||
699 			    bp->bp_port_htime != cu->cu_hello_time)
700 				/* bpdu priority is equal and timers differ */
701 				type = BSTP_PDU_SUPERIOR;
702 			else
703 				/* bpdu is equal */
704 				type = BSTP_PDU_REPEATED;
705 		} else
706 			/* bpdu priority is worse */
707 			type = BSTP_PDU_INFERIOR;
708 
709 		break;
710 
711 	case BSTP_ROLE_ROOT:
712 	case BSTP_ROLE_ALTERNATE:
713 	case BSTP_ROLE_BACKUP:
714 		if (bstp_info_cmp(&bp->bp_port_pv, &cu->cu_pv) <= INFO_SAME)
715 			/*
716 			 * not a designated port and priority is the same or
717 			 * worse
718 			 */
719 			type = BSTP_PDU_INFERIORALT;
720 		break;
721 	}
722 
723 	return (type);
724 }
725 
726 static int
727 bstp_pdu_bettersame(struct bstp_port *bp, int newinfo)
728 {
729 	if (newinfo == BSTP_INFO_RECIEVED &&
730 	    bp->bp_infois == BSTP_INFO_RECIEVED &&
731 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_msg_cu.cu_pv) >= INFO_SAME)
732 		return (1);
733 
734 	if (newinfo == BSTP_INFO_MINE &&
735 	    bp->bp_infois == BSTP_INFO_MINE &&
736 	    bstp_info_cmp(&bp->bp_port_pv, &bp->bp_desg_pv) >= INFO_SAME)
737 		return (1);
738 
739 	return (0);
740 }
741 
742 static int
743 bstp_info_cmp(struct bstp_pri_vector *pv,
744     struct bstp_pri_vector *cpv)
745 {
746 	if (cpv->pv_root_id < pv->pv_root_id)
747 		return (INFO_BETTER);
748 	if (cpv->pv_root_id > pv->pv_root_id)
749 		return (INFO_WORSE);
750 
751 	if (cpv->pv_cost < pv->pv_cost)
752 		return (INFO_BETTER);
753 	if (cpv->pv_cost > pv->pv_cost)
754 		return (INFO_WORSE);
755 
756 	if (cpv->pv_dbridge_id < pv->pv_dbridge_id)
757 		return (INFO_BETTER);
758 	if (cpv->pv_dbridge_id > pv->pv_dbridge_id)
759 		return (INFO_WORSE);
760 
761 	if (cpv->pv_dport_id < pv->pv_dport_id)
762 		return (INFO_BETTER);
763 	if (cpv->pv_dport_id > pv->pv_dport_id)
764 		return (INFO_WORSE);
765 
766 	return (INFO_SAME);
767 }
768 
769 /*
770  * This message priority vector is superior to the port priority vector and
771  * will replace it if, and only if, the message priority vector is better than
772  * the port priority vector, or the message has been transmitted from the same
773  * designated bridge and designated port as the port priority vector.
774  */
775 static int
776 bstp_info_superior(struct bstp_pri_vector *pv,
777     struct bstp_pri_vector *cpv)
778 {
779 	if (bstp_info_cmp(pv, cpv) == INFO_BETTER ||
780 	    (bstp_same_bridgeid(pv->pv_dbridge_id, cpv->pv_dbridge_id) &&
781 	    (cpv->pv_dport_id & 0xfff) == (pv->pv_dport_id & 0xfff)))
782 		return (1);
783 	return (0);
784 }
785 
786 static void
787 bstp_assign_roles(struct bstp_state *bs)
788 {
789 	struct bstp_port *bp, *rbp = NULL;
790 	struct bstp_pri_vector pv;
791 
792 	/* default to our priority vector */
793 	bs->bs_root_pv = bs->bs_bridge_pv;
794 	bs->bs_root_msg_age = 0;
795 	bs->bs_root_max_age = bs->bs_bridge_max_age;
796 	bs->bs_root_fdelay = bs->bs_bridge_fdelay;
797 	bs->bs_root_htime = bs->bs_bridge_htime;
798 	bs->bs_root_port = NULL;
799 
800 	/* check if any recieved info supersedes us */
801 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
802 		if (bp->bp_infois != BSTP_INFO_RECIEVED)
803 			continue;
804 
805 		pv = bp->bp_port_pv;
806 		pv.pv_cost += bp->bp_path_cost;
807 
808 		/*
809 		 * The root priority vector is the best of the set comprising
810 		 * the bridge priority vector plus all root path priority
811 		 * vectors whose bridge address is not equal to us.
812 		 */
813 		if (bstp_same_bridgeid(pv.pv_dbridge_id,
814 		    bs->bs_bridge_pv.pv_dbridge_id) == 0 &&
815 		    bstp_info_cmp(&bs->bs_root_pv, &pv) == INFO_BETTER) {
816 			/* the port vector replaces the root */
817 			bs->bs_root_pv = pv;
818 			bs->bs_root_msg_age = bp->bp_port_msg_age +
819 			    BSTP_MESSAGE_AGE_INCR;
820 			bs->bs_root_max_age = bp->bp_port_max_age;
821 			bs->bs_root_fdelay = bp->bp_port_fdelay;
822 			bs->bs_root_htime = bp->bp_port_htime;
823 			rbp = bp;
824 		}
825 	}
826 
827 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
828 		/* calculate the port designated vector */
829 		bp->bp_desg_pv.pv_root_id = bs->bs_root_pv.pv_root_id;
830 		bp->bp_desg_pv.pv_cost = bs->bs_root_pv.pv_cost;
831 		bp->bp_desg_pv.pv_dbridge_id = bs->bs_bridge_pv.pv_dbridge_id;
832 		bp->bp_desg_pv.pv_dport_id = bp->bp_port_id;
833 		bp->bp_desg_pv.pv_port_id = bp->bp_port_id;
834 
835 		/* calculate designated times */
836 		bp->bp_desg_msg_age = bs->bs_root_msg_age;
837 		bp->bp_desg_max_age = bs->bs_root_max_age;
838 		bp->bp_desg_fdelay = bs->bs_root_fdelay;
839 		bp->bp_desg_htime = bs->bs_bridge_htime;
840 
841 
842 		switch (bp->bp_infois) {
843 		case BSTP_INFO_DISABLED:
844 			bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
845 			break;
846 
847 		case BSTP_INFO_AGED:
848 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
849 			bstp_update_info(bp);
850 			break;
851 
852 		case BSTP_INFO_MINE:
853 			bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
854 			/* update the port info if stale */
855 			if (bstp_info_cmp(&bp->bp_port_pv,
856 			    &bp->bp_desg_pv) != INFO_SAME ||
857 			    (rbp != NULL &&
858 			    (bp->bp_port_msg_age != rbp->bp_port_msg_age ||
859 			    bp->bp_port_max_age != rbp->bp_port_max_age ||
860 			    bp->bp_port_fdelay != rbp->bp_port_fdelay ||
861 			    bp->bp_port_htime != rbp->bp_port_htime)))
862 				bstp_update_info(bp);
863 			break;
864 
865 		case BSTP_INFO_RECIEVED:
866 			if (bp == rbp) {
867 				/*
868 				 * root priority is derived from this
869 				 * port, make it the root port.
870 				 */
871 				bstp_set_port_role(bp, BSTP_ROLE_ROOT);
872 				bs->bs_root_port = bp;
873 			} else if (bstp_info_cmp(&bp->bp_port_pv,
874 				    &bp->bp_desg_pv) == INFO_BETTER) {
875 				/*
876 				 * the port priority is lower than the root
877 				 * port.
878 				 */
879 				bstp_set_port_role(bp, BSTP_ROLE_DESIGNATED);
880 				bstp_update_info(bp);
881 			} else {
882 				if (bstp_same_bridgeid(
883 				    bp->bp_port_pv.pv_dbridge_id,
884 				    bs->bs_bridge_pv.pv_dbridge_id)) {
885 					/*
886 					 * the designated bridge refers to
887 					 * another port on this bridge.
888 					 */
889 					bstp_set_port_role(bp,
890 					    BSTP_ROLE_BACKUP);
891 				} else {
892 					/*
893 					 * the port is an inferior path to the
894 					 * root bridge.
895 					 */
896 					bstp_set_port_role(bp,
897 					    BSTP_ROLE_ALTERNATE);
898 				}
899 			}
900 			break;
901 		}
902 	}
903 }
904 
905 static void
906 bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
907 {
908 	struct bstp_port *bp2;
909 	int synced;
910 
911 	BSTP_LOCK_ASSERT(bs);
912 
913 	/* check if all the ports have syncronised again */
914 	if (!bs->bs_allsynced) {
915 		synced = 1;
916 		LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
917 			if (!(bp->bp_synced ||
918 			     bp->bp_role == BSTP_ROLE_ROOT)) {
919 				synced = 0;
920 				break;
921 			}
922 		}
923 		bs->bs_allsynced = synced;
924 	}
925 
926 	bstp_update_roles(bs, bp);
927 	bstp_update_tc(bp);
928 }
929 
930 static void
931 bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
932 {
933 	switch (bp->bp_role) {
934 	case BSTP_ROLE_DISABLED:
935 		/* Clear any flags if set */
936 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
937 			bp->bp_sync = 0;
938 			bp->bp_synced = 1;
939 			bp->bp_reroot = 0;
940 		}
941 		break;
942 
943 	case BSTP_ROLE_ALTERNATE:
944 	case BSTP_ROLE_BACKUP:
945 		if ((bs->bs_allsynced && !bp->bp_agree) ||
946 		    (bp->bp_proposed && bp->bp_agree)) {
947 			bp->bp_proposed = 0;
948 			bp->bp_agree = 1;
949 			bp->bp_flags |= BSTP_PORT_NEWINFO;
950 			DPRINTF("%s -> ALTERNATE_AGREED\n",
951 			    bp->bp_ifp->if_xname);
952 		}
953 
954 		if (bp->bp_proposed && !bp->bp_agree) {
955 			bstp_set_all_sync(bs);
956 			bp->bp_proposed = 0;
957 			DPRINTF("%s -> ALTERNATE_PROPOSED\n",
958 			    bp->bp_ifp->if_xname);
959 		}
960 
961 		/* Clear any flags if set */
962 		if (bp->bp_sync || !bp->bp_synced || bp->bp_reroot) {
963 			bp->bp_sync = 0;
964 			bp->bp_synced = 1;
965 			bp->bp_reroot = 0;
966 			DPRINTF("%s -> ALTERNATE_PORT\n", bp->bp_ifp->if_xname);
967 		}
968 		break;
969 
970 	case BSTP_ROLE_ROOT:
971 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING && !bp->bp_reroot) {
972 			bstp_set_all_reroot(bs);
973 			DPRINTF("%s -> ROOT_REROOT\n", bp->bp_ifp->if_xname);
974 		}
975 
976 		if ((bs->bs_allsynced && !bp->bp_agree) ||
977 		    (bp->bp_proposed && bp->bp_agree)) {
978 			bp->bp_proposed = 0;
979 			bp->bp_sync = 0;
980 			bp->bp_agree = 1;
981 			bp->bp_flags |= BSTP_PORT_NEWINFO;
982 			DPRINTF("%s -> ROOT_AGREED\n", bp->bp_ifp->if_xname);
983 		}
984 
985 		if (bp->bp_proposed && !bp->bp_agree) {
986 			bstp_set_all_sync(bs);
987 			bp->bp_proposed = 0;
988 			DPRINTF("%s -> ROOT_PROPOSED\n", bp->bp_ifp->if_xname);
989 		}
990 
991 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
992 		    (bp->bp_forward_delay_timer.active == 0 ||
993 		    (bstp_rerooted(bs, bp) &&
994 		    bp->bp_recent_backup_timer.active == 0 &&
995 		    bp->bp_protover == BSTP_PROTO_RSTP))) {
996 			switch (bp->bp_state) {
997 			case BSTP_IFSTATE_DISCARDING:
998 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
999 				break;
1000 			case BSTP_IFSTATE_LEARNING:
1001 				bstp_set_port_state(bp,
1002 				    BSTP_IFSTATE_FORWARDING);
1003 				break;
1004 			}
1005 		}
1006 
1007 		if (bp->bp_state == BSTP_IFSTATE_FORWARDING && bp->bp_reroot) {
1008 			bp->bp_reroot = 0;
1009 			DPRINTF("%s -> ROOT_REROOTED\n", bp->bp_ifp->if_xname);
1010 		}
1011 		break;
1012 
1013 	case BSTP_ROLE_DESIGNATED:
1014 		if (bp->bp_recent_root_timer.active == 0 && bp->bp_reroot) {
1015 			bp->bp_reroot = 0;
1016 			DPRINTF("%s -> DESIGNATED_RETIRED\n",
1017 			    bp->bp_ifp->if_xname);
1018 		}
1019 
1020 		if ((bp->bp_state == BSTP_IFSTATE_DISCARDING &&
1021 		    !bp->bp_synced) || (bp->bp_agreed && !bp->bp_synced) ||
1022 		    (bp->bp_operedge && !bp->bp_synced) ||
1023 		    (bp->bp_sync && bp->bp_synced)) {
1024 			bstp_timer_stop(&bp->bp_recent_root_timer);
1025 			bp->bp_synced = 1;
1026 			bp->bp_sync = 0;
1027 			DPRINTF("%s -> DESIGNATED_SYNCED\n",
1028 			    bp->bp_ifp->if_xname);
1029 		}
1030 
1031 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1032 		    !bp->bp_agreed && !bp->bp_proposing &&
1033 		    !bp->bp_operedge) {
1034 			bp->bp_proposing = 1;
1035 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1036 			bstp_timer_start(&bp->bp_edge_delay_timer,
1037 			    (bp->bp_p2p_link ? BSTP_DEFAULT_MIGRATE_DELAY :
1038 			     bp->bp_desg_max_age));
1039 			DPRINTF("%s -> DESIGNATED_PROPOSE\n",
1040 			    bp->bp_ifp->if_xname);
1041 		}
1042 
1043 		if (bp->bp_state != BSTP_IFSTATE_FORWARDING &&
1044 		    (bp->bp_forward_delay_timer.active == 0 || bp->bp_agreed ||
1045 		    bp->bp_operedge) &&
1046 		    (bp->bp_recent_root_timer.active == 0 || !bp->bp_reroot) &&
1047 		    !bp->bp_sync) {
1048 			if (bp->bp_agreed)
1049 				DPRINTF("%s -> AGREED\n", bp->bp_ifp->if_xname);
1050 			/*
1051 			 * If agreed|operedge then go straight to forwarding,
1052 			 * otherwise follow discard -> learn -> forward.
1053 			 */
1054 			if (bp->bp_agreed || bp->bp_operedge ||
1055 			    bp->bp_state == BSTP_IFSTATE_LEARNING) {
1056 				bstp_set_port_state(bp,
1057 				    BSTP_IFSTATE_FORWARDING);
1058 				bp->bp_agreed = bp->bp_protover;
1059 			} else if (bp->bp_state == BSTP_IFSTATE_DISCARDING)
1060 				bstp_set_port_state(bp, BSTP_IFSTATE_LEARNING);
1061 		}
1062 
1063 		if (((bp->bp_sync && !bp->bp_synced) ||
1064 		    (bp->bp_reroot && bp->bp_recent_root_timer.active) ||
1065 		    (bp->bp_flags & BSTP_PORT_DISPUTED)) && !bp->bp_operedge &&
1066 		    bp->bp_state != BSTP_IFSTATE_DISCARDING) {
1067 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1068 			bp->bp_flags &= ~BSTP_PORT_DISPUTED;
1069 			bstp_timer_start(&bp->bp_forward_delay_timer,
1070 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1071 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1072 			DPRINTF("%s -> DESIGNATED_DISCARD\n",
1073 			    bp->bp_ifp->if_xname);
1074 		}
1075 		break;
1076 	}
1077 
1078 	if (bp->bp_flags & BSTP_PORT_NEWINFO)
1079 		bstp_transmit(bs, bp);
1080 }
1081 
1082 static void
1083 bstp_update_tc(struct bstp_port *bp)
1084 {
1085 	switch (bp->bp_tcstate) {
1086 		case BSTP_TCSTATE_ACTIVE:
1087 			if ((bp->bp_role != BSTP_ROLE_DESIGNATED &&
1088 			    bp->bp_role != BSTP_ROLE_ROOT) || bp->bp_operedge)
1089 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1090 
1091 			if (bp->bp_rcvdtcn)
1092 				bstp_set_port_tc(bp, BSTP_TCSTATE_TCN);
1093 			if (bp->bp_rcvdtc)
1094 				bstp_set_port_tc(bp, BSTP_TCSTATE_TC);
1095 
1096 			if (bp->bp_tc_prop && !bp->bp_operedge)
1097 				bstp_set_port_tc(bp, BSTP_TCSTATE_PROPAG);
1098 
1099 			if (bp->bp_rcvdtca)
1100 				bstp_set_port_tc(bp, BSTP_TCSTATE_ACK);
1101 			break;
1102 
1103 		case BSTP_TCSTATE_INACTIVE:
1104 			if ((bp->bp_state == BSTP_IFSTATE_LEARNING ||
1105 			    bp->bp_state == BSTP_IFSTATE_FORWARDING) &&
1106 			    bp->bp_fdbflush == 0)
1107 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1108 			break;
1109 
1110 		case BSTP_TCSTATE_LEARNING:
1111 			if (bp->bp_rcvdtc || bp->bp_rcvdtcn || bp->bp_rcvdtca ||
1112 			    bp->bp_tc_prop)
1113 				bstp_set_port_tc(bp, BSTP_TCSTATE_LEARNING);
1114 			else if (bp->bp_role != BSTP_ROLE_DESIGNATED &&
1115 				 bp->bp_role != BSTP_ROLE_ROOT &&
1116 				 bp->bp_state == BSTP_IFSTATE_DISCARDING)
1117 				bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1118 
1119 			if ((bp->bp_role == BSTP_ROLE_DESIGNATED ||
1120 			    bp->bp_role == BSTP_ROLE_ROOT) &&
1121 			    bp->bp_state == BSTP_IFSTATE_FORWARDING &&
1122 			    !bp->bp_operedge)
1123 				bstp_set_port_tc(bp, BSTP_TCSTATE_DETECTED);
1124 			break;
1125 
1126 		/* these are transient states and go straight back to ACTIVE */
1127 		case BSTP_TCSTATE_DETECTED:
1128 		case BSTP_TCSTATE_TCN:
1129 		case BSTP_TCSTATE_TC:
1130 		case BSTP_TCSTATE_PROPAG:
1131 		case BSTP_TCSTATE_ACK:
1132 			DPRINTF("Invalid TC state for %s\n",
1133 			    bp->bp_ifp->if_xname);
1134 			break;
1135 	}
1136 
1137 }
1138 
1139 static void
1140 bstp_update_info(struct bstp_port *bp)
1141 {
1142 	struct bstp_state *bs = bp->bp_bs;
1143 
1144 	bp->bp_proposing = 0;
1145 	bp->bp_proposed = 0;
1146 
1147 	if (bp->bp_agreed && !bstp_pdu_bettersame(bp, BSTP_INFO_MINE))
1148 		bp->bp_agreed = 0;
1149 
1150 	if (bp->bp_synced && !bp->bp_agreed) {
1151 		bp->bp_synced = 0;
1152 		bs->bs_allsynced = 0;
1153 	}
1154 
1155 	/* copy the designated pv to the port */
1156 	bp->bp_port_pv = bp->bp_desg_pv;
1157 	bp->bp_port_msg_age = bp->bp_desg_msg_age;
1158 	bp->bp_port_max_age = bp->bp_desg_max_age;
1159 	bp->bp_port_fdelay = bp->bp_desg_fdelay;
1160 	bp->bp_port_htime = bp->bp_desg_htime;
1161 	bp->bp_infois = BSTP_INFO_MINE;
1162 
1163 	/* Set transmit flag but do not immediately send */
1164 	bp->bp_flags |= BSTP_PORT_NEWINFO;
1165 }
1166 
1167 /* set tcprop on every port other than the caller */
1168 static void
1169 bstp_set_other_tcprop(struct bstp_port *bp)
1170 {
1171 	struct bstp_state *bs = bp->bp_bs;
1172 	struct bstp_port *bp2;
1173 
1174 	BSTP_LOCK_ASSERT(bs);
1175 
1176 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1177 		if (bp2 == bp)
1178 			continue;
1179 		bp->bp_tc_prop = 1;
1180 	}
1181 }
1182 
1183 static void
1184 bstp_set_all_reroot(struct bstp_state *bs)
1185 {
1186 	struct bstp_port *bp;
1187 
1188 	BSTP_LOCK_ASSERT(bs);
1189 
1190 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1191 		bp->bp_reroot = 1;
1192 }
1193 
1194 static void
1195 bstp_set_all_sync(struct bstp_state *bs)
1196 {
1197 	struct bstp_port *bp;
1198 
1199 	BSTP_LOCK_ASSERT(bs);
1200 
1201 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1202 		bp->bp_sync = 1;
1203 		bp->bp_synced = 0;	/* Not explicit in spec */
1204 	}
1205 
1206 	bs->bs_allsynced = 0;
1207 }
1208 
1209 static void
1210 bstp_set_port_state(struct bstp_port *bp, int state)
1211 {
1212 	if (bp->bp_state == state)
1213 		return;
1214 
1215 	bp->bp_state = state;
1216 
1217 	switch (bp->bp_state) {
1218 		case BSTP_IFSTATE_DISCARDING:
1219 			DPRINTF("state changed to DISCARDING on %s\n",
1220 			    bp->bp_ifp->if_xname);
1221 			break;
1222 
1223 		case BSTP_IFSTATE_LEARNING:
1224 			DPRINTF("state changed to LEARNING on %s\n",
1225 			    bp->bp_ifp->if_xname);
1226 
1227 			bstp_timer_start(&bp->bp_forward_delay_timer,
1228 			    bp->bp_protover == BSTP_PROTO_RSTP ?
1229 			    bp->bp_desg_htime : bp->bp_desg_fdelay);
1230 			break;
1231 
1232 		case BSTP_IFSTATE_FORWARDING:
1233 			DPRINTF("state changed to FORWARDING on %s\n",
1234 			    bp->bp_ifp->if_xname);
1235 
1236 			bstp_timer_stop(&bp->bp_forward_delay_timer);
1237 			/* Record that we enabled forwarding */
1238 			bp->bp_forward_transitions++;
1239 			break;
1240 	}
1241 
1242 	/* notify the parent bridge */
1243 	taskqueue_enqueue(taskqueue_swi, &bp->bp_statetask);
1244 }
1245 
1246 static void
1247 bstp_set_port_role(struct bstp_port *bp, int role)
1248 {
1249 	struct bstp_state *bs = bp->bp_bs;
1250 
1251 	if (bp->bp_role == role)
1252 		return;
1253 
1254 	/* perform pre-change tasks */
1255 	switch (bp->bp_role) {
1256 		case BSTP_ROLE_DISABLED:
1257 			bstp_timer_start(&bp->bp_forward_delay_timer,
1258 			    bp->bp_desg_max_age);
1259 			break;
1260 
1261 		case BSTP_ROLE_BACKUP:
1262 			bstp_timer_start(&bp->bp_recent_backup_timer,
1263 			    bp->bp_desg_htime * 2);
1264 			/* fall through */
1265 		case BSTP_ROLE_ALTERNATE:
1266 			bstp_timer_start(&bp->bp_forward_delay_timer,
1267 			    bp->bp_desg_fdelay);
1268 			bp->bp_sync = 0;
1269 			bp->bp_synced = 1;
1270 			bp->bp_reroot = 0;
1271 			break;
1272 
1273 		case BSTP_ROLE_ROOT:
1274 			bstp_timer_start(&bp->bp_recent_root_timer,
1275 			    BSTP_DEFAULT_FORWARD_DELAY);
1276 			break;
1277 	}
1278 
1279 	bp->bp_role = role;
1280 	/* clear values not carried between roles */
1281 	bp->bp_proposing = 0;
1282 	bs->bs_allsynced = 0;
1283 
1284 	/* initialise the new role */
1285 	switch (bp->bp_role) {
1286 		case BSTP_ROLE_DISABLED:
1287 		case BSTP_ROLE_ALTERNATE:
1288 		case BSTP_ROLE_BACKUP:
1289 			DPRINTF("%s role -> ALT/BACK/DISABLED\n",
1290 			    bp->bp_ifp->if_xname);
1291 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1292 			bstp_timer_stop(&bp->bp_recent_root_timer);
1293 			bstp_timer_latch(&bp->bp_forward_delay_timer);
1294 			bp->bp_sync = 0;
1295 			bp->bp_synced = 1;
1296 			bp->bp_reroot = 0;
1297 			break;
1298 
1299 		case BSTP_ROLE_ROOT:
1300 			DPRINTF("%s role -> ROOT\n",
1301 			    bp->bp_ifp->if_xname);
1302 			bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1303 			bstp_timer_latch(&bp->bp_recent_root_timer);
1304 			bp->bp_proposing = 0;
1305 			break;
1306 
1307 		case BSTP_ROLE_DESIGNATED:
1308 			DPRINTF("%s role -> DESIGNATED\n",
1309 			    bp->bp_ifp->if_xname);
1310 			bstp_timer_start(&bp->bp_hello_timer,
1311 			    bp->bp_desg_htime);
1312 			bp->bp_agree = 0;
1313 			break;
1314 	}
1315 
1316 	/* let the TC state know that the role changed */
1317 	bstp_update_tc(bp);
1318 }
1319 
1320 static void
1321 bstp_set_port_proto(struct bstp_port *bp, int proto)
1322 {
1323 	struct bstp_state *bs = bp->bp_bs;
1324 
1325 	/* supported protocol versions */
1326 	switch (proto) {
1327 		case BSTP_PROTO_STP:
1328 			/* we can downgrade protocols only */
1329 			bstp_timer_stop(&bp->bp_migrate_delay_timer);
1330 			/* clear unsupported features */
1331 			bp->bp_operedge = 0;
1332 			break;
1333 
1334 		case BSTP_PROTO_RSTP:
1335 			bstp_timer_start(&bp->bp_migrate_delay_timer,
1336 			    bs->bs_migration_delay);
1337 			break;
1338 
1339 		default:
1340 			DPRINTF("Unsupported STP version %d\n", proto);
1341 			return;
1342 	}
1343 
1344 	bp->bp_protover = proto;
1345 	bp->bp_flags &= ~BSTP_PORT_CANMIGRATE;
1346 }
1347 
1348 static void
1349 bstp_set_port_tc(struct bstp_port *bp, int state)
1350 {
1351 	struct bstp_state *bs = bp->bp_bs;
1352 
1353 	bp->bp_tcstate = state;
1354 
1355 	/* initialise the new state */
1356 	switch (bp->bp_tcstate) {
1357 		case BSTP_TCSTATE_ACTIVE:
1358 			DPRINTF("%s -> TC_ACTIVE\n", bp->bp_ifp->if_xname);
1359 			/* nothing to do */
1360 			break;
1361 
1362 		case BSTP_TCSTATE_INACTIVE:
1363 			bstp_timer_stop(&bp->bp_tc_timer);
1364 			/* flush routes on the parent bridge */
1365 			bp->bp_fdbflush = 1;
1366 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1367 			bp->bp_tc_ack = 0;
1368 			DPRINTF("%s -> TC_INACTIVE\n", bp->bp_ifp->if_xname);
1369 			break;
1370 
1371 		case BSTP_TCSTATE_LEARNING:
1372 			bp->bp_rcvdtc = 0;
1373 			bp->bp_rcvdtcn = 0;
1374 			bp->bp_rcvdtca = 0;
1375 			bp->bp_tc_prop = 0;
1376 			DPRINTF("%s -> TC_LEARNING\n", bp->bp_ifp->if_xname);
1377 			break;
1378 
1379 		case BSTP_TCSTATE_DETECTED:
1380 			bstp_set_timer_tc(bp);
1381 			bstp_set_other_tcprop(bp);
1382 			/* send out notification */
1383 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1384 			bstp_transmit(bs, bp);
1385 			getmicrotime(&bs->bs_last_tc_time);
1386 			DPRINTF("%s -> TC_DETECTED\n", bp->bp_ifp->if_xname);
1387 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1388 			break;
1389 
1390 		case BSTP_TCSTATE_TCN:
1391 			bstp_set_timer_tc(bp);
1392 			DPRINTF("%s -> TC_TCN\n", bp->bp_ifp->if_xname);
1393 			/* fall through */
1394 		case BSTP_TCSTATE_TC:
1395 			bp->bp_rcvdtc = 0;
1396 			bp->bp_rcvdtcn = 0;
1397 			if (bp->bp_role == BSTP_ROLE_DESIGNATED)
1398 				bp->bp_tc_ack = 1;
1399 
1400 			bstp_set_other_tcprop(bp);
1401 			DPRINTF("%s -> TC_TC\n", bp->bp_ifp->if_xname);
1402 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1403 			break;
1404 
1405 		case BSTP_TCSTATE_PROPAG:
1406 			/* flush routes on the parent bridge */
1407 			bp->bp_fdbflush = 1;
1408 			taskqueue_enqueue(taskqueue_swi, &bp->bp_rtagetask);
1409 			bp->bp_tc_prop = 0;
1410 			bstp_set_timer_tc(bp);
1411 			DPRINTF("%s -> TC_PROPAG\n", bp->bp_ifp->if_xname);
1412 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1413 			break;
1414 
1415 		case BSTP_TCSTATE_ACK:
1416 			bstp_timer_stop(&bp->bp_tc_timer);
1417 			bp->bp_rcvdtca = 0;
1418 			DPRINTF("%s -> TC_ACK\n", bp->bp_ifp->if_xname);
1419 			bp->bp_tcstate = BSTP_TCSTATE_ACTIVE; /* UCT */
1420 			break;
1421 	}
1422 }
1423 
1424 static void
1425 bstp_set_timer_tc(struct bstp_port *bp)
1426 {
1427 	struct bstp_state *bs = bp->bp_bs;
1428 
1429 	if (bp->bp_tc_timer.active)
1430 		return;
1431 
1432 	switch (bp->bp_protover) {
1433 		case BSTP_PROTO_RSTP:
1434 			bstp_timer_start(&bp->bp_tc_timer,
1435 			    bp->bp_desg_htime + BSTP_TICK_VAL);
1436 			bp->bp_flags |= BSTP_PORT_NEWINFO;
1437 			break;
1438 
1439 		case BSTP_PROTO_STP:
1440 			bstp_timer_start(&bp->bp_tc_timer,
1441 			    bs->bs_root_max_age + bs->bs_root_fdelay);
1442 			break;
1443 	}
1444 }
1445 
1446 static void
1447 bstp_set_timer_msgage(struct bstp_port *bp)
1448 {
1449 	if (bp->bp_port_msg_age + BSTP_MESSAGE_AGE_INCR <=
1450 	    bp->bp_port_max_age) {
1451 		bstp_timer_start(&bp->bp_message_age_timer,
1452 		    bp->bp_port_htime * 3);
1453 	} else
1454 		/* expires immediately */
1455 		bstp_timer_start(&bp->bp_message_age_timer, 0);
1456 }
1457 
1458 static int
1459 bstp_rerooted(struct bstp_state *bs, struct bstp_port *bp)
1460 {
1461 	struct bstp_port *bp2;
1462 	int rr_set = 0;
1463 
1464 	LIST_FOREACH(bp2, &bs->bs_bplist, bp_next) {
1465 		if (bp2 == bp)
1466 			continue;
1467 		if (bp2->bp_recent_root_timer.active) {
1468 			rr_set = 1;
1469 			break;
1470 		}
1471 	}
1472 	return (!rr_set);
1473 }
1474 
1475 int
1476 bstp_set_htime(struct bstp_state *bs, int t)
1477 {
1478 	/* convert seconds to ticks */
1479 	t *=  BSTP_TICK_VAL;
1480 
1481 	/* value can only be changed in leagacy stp mode */
1482 	if (bs->bs_protover != BSTP_PROTO_STP)
1483 		return (EPERM);
1484 
1485 	if (t < BSTP_MIN_HELLO_TIME || t > BSTP_MAX_HELLO_TIME)
1486 		return (EINVAL);
1487 
1488 	BSTP_LOCK(bs);
1489 	bs->bs_bridge_htime = t;
1490 	bstp_reinit(bs);
1491 	BSTP_UNLOCK(bs);
1492 	return (0);
1493 }
1494 
1495 int
1496 bstp_set_fdelay(struct bstp_state *bs, int t)
1497 {
1498 	/* convert seconds to ticks */
1499 	t *= BSTP_TICK_VAL;
1500 
1501 	if (t < BSTP_MIN_FORWARD_DELAY || t > BSTP_MAX_FORWARD_DELAY)
1502 		return (EINVAL);
1503 
1504 	BSTP_LOCK(bs);
1505 	bs->bs_bridge_fdelay = t;
1506 	bstp_reinit(bs);
1507 	BSTP_UNLOCK(bs);
1508 	return (0);
1509 }
1510 
1511 int
1512 bstp_set_maxage(struct bstp_state *bs, int t)
1513 {
1514 	/* convert seconds to ticks */
1515 	t *= BSTP_TICK_VAL;
1516 
1517 	if (t < BSTP_MIN_MAX_AGE || t > BSTP_MAX_MAX_AGE)
1518 		return (EINVAL);
1519 
1520 	BSTP_LOCK(bs);
1521 	bs->bs_bridge_max_age = t;
1522 	bstp_reinit(bs);
1523 	BSTP_UNLOCK(bs);
1524 	return (0);
1525 }
1526 
1527 int
1528 bstp_set_holdcount(struct bstp_state *bs, int count)
1529 {
1530 	struct bstp_port *bp;
1531 
1532 	if (count < BSTP_MIN_HOLD_COUNT ||
1533 	    count > BSTP_MAX_HOLD_COUNT)
1534 		return (EINVAL);
1535 
1536 	BSTP_LOCK(bs);
1537 	bs->bs_txholdcount = count;
1538 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1539 		bp->bp_txcount = 0;
1540 	BSTP_UNLOCK(bs);
1541 	return (0);
1542 }
1543 
1544 int
1545 bstp_set_protocol(struct bstp_state *bs, int proto)
1546 {
1547 	struct bstp_port *bp;
1548 
1549 	switch (proto) {
1550 		/* Supported protocol versions */
1551 		case BSTP_PROTO_STP:
1552 		case BSTP_PROTO_RSTP:
1553 			break;
1554 
1555 		default:
1556 			return (EINVAL);
1557 	}
1558 
1559 	BSTP_LOCK(bs);
1560 	bs->bs_protover = proto;
1561 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
1562 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1563 		/* reinit state */
1564 		bp->bp_infois = BSTP_INFO_DISABLED;
1565 		bp->bp_txcount = 0;
1566 		bstp_set_port_proto(bp, bs->bs_protover);
1567 		bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
1568 		bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
1569 		bstp_timer_stop(&bp->bp_recent_backup_timer);
1570 	}
1571 	bstp_reinit(bs);
1572 	BSTP_UNLOCK(bs);
1573 	return (0);
1574 }
1575 
1576 int
1577 bstp_set_priority(struct bstp_state *bs, int pri)
1578 {
1579 	if (pri < 0 || pri > BSTP_MAX_PRIORITY)
1580 		return (EINVAL);
1581 
1582 	/* Limit to steps of 4096 */
1583 	pri -= pri % 4096;
1584 
1585 	BSTP_LOCK(bs);
1586 	bs->bs_bridge_priority = pri;
1587 	bstp_reinit(bs);
1588 	BSTP_UNLOCK(bs);
1589 	return (0);
1590 }
1591 
1592 int
1593 bstp_set_port_priority(struct bstp_port *bp, int pri)
1594 {
1595 	struct bstp_state *bs = bp->bp_bs;
1596 
1597 	if (pri < 0 || pri > BSTP_MAX_PORT_PRIORITY)
1598 		return (EINVAL);
1599 
1600 	/* Limit to steps of 16 */
1601 	pri -= pri % 16;
1602 
1603 	BSTP_LOCK(bs);
1604 	bp->bp_priority = pri;
1605 	bstp_reinit(bs);
1606 	BSTP_UNLOCK(bs);
1607 	return (0);
1608 }
1609 
1610 int
1611 bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
1612 {
1613 	struct bstp_state *bs = bp->bp_bs;
1614 
1615 	if (path_cost > BSTP_MAX_PATH_COST)
1616 		return (EINVAL);
1617 
1618 	BSTP_LOCK(bs);
1619 
1620 	if (path_cost == 0) {	/* use auto */
1621 		bp->bp_flags &= ~BSTP_PORT_ADMCOST;
1622 		bp->bp_path_cost = bstp_calc_path_cost(bp);
1623 	} else {
1624 		bp->bp_path_cost = path_cost;
1625 		bp->bp_flags |= BSTP_PORT_ADMCOST;
1626 	}
1627 	bstp_reinit(bs);
1628 	BSTP_UNLOCK(bs);
1629 	return (0);
1630 }
1631 
1632 int
1633 bstp_set_edge(struct bstp_port *bp, int set)
1634 {
1635 	struct bstp_state *bs = bp->bp_bs;
1636 
1637 	BSTP_LOCK(bs);
1638 	bp->bp_operedge = set;
1639 	BSTP_UNLOCK(bs);
1640 	return (0);
1641 }
1642 
1643 int
1644 bstp_set_autoedge(struct bstp_port *bp, int set)
1645 {
1646 	struct bstp_state *bs = bp->bp_bs;
1647 
1648 	BSTP_LOCK(bs);
1649 	if (set) {
1650 		bp->bp_flags |= BSTP_PORT_AUTOEDGE;
1651 		/* we may be able to transition straight to edge */
1652 		if (bp->bp_edge_delay_timer.active == 0)
1653 			bstp_edge_delay_expiry(bs, bp);
1654 	} else
1655 		bp->bp_flags &= ~BSTP_PORT_AUTOEDGE;
1656 	BSTP_UNLOCK(bs);
1657 	return (0);
1658 }
1659 /*
1660  * Calculate the path cost according to the link speed.
1661  */
1662 static uint32_t
1663 bstp_calc_path_cost(struct bstp_port *bp)
1664 {
1665 	struct ifnet *ifp = bp->bp_ifp;
1666 	uint32_t path_cost;
1667 
1668 	/* If the priority has been manually set then retain the value */
1669 	if (bp->bp_flags & BSTP_PORT_ADMCOST)
1670 		return bp->bp_path_cost;
1671 
1672 	if (ifp->if_baudrate < 1000)
1673 		return (BSTP_DEFAULT_PATH_COST);
1674 
1675  	/* formula from section 17.14, IEEE Std 802.1D-2004 */
1676 	path_cost = 20000000000 / (ifp->if_baudrate / 1000);
1677 
1678 	if (path_cost > BSTP_MAX_PATH_COST)
1679 		path_cost = BSTP_MAX_PATH_COST;
1680 
1681 	/* STP compat mode only uses 16 bits of the 32 */
1682 	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
1683 		path_cost = 65535;
1684 
1685 	return (path_cost);
1686 }
1687 
1688 /*
1689  * Notify the bridge that a port state has changed, we need to do this from a
1690  * taskqueue to avoid a LOR.
1691  */
1692 static void
1693 bstp_notify_state(void *arg, int pending)
1694 {
1695 	struct bstp_port *bp = (struct bstp_port *)arg;
1696 	struct bstp_state *bs = bp->bp_bs;
1697 
1698 	if (bp->bp_active == 1 && bs->bs_state_cb != NULL)
1699 		(*bs->bs_state_cb)(bp->bp_ifp, bp->bp_state);
1700 }
1701 
1702 /*
1703  * Flush the routes on the bridge port, we need to do this from a
1704  * taskqueue to avoid a LOR.
1705  */
1706 static void
1707 bstp_notify_rtage(void *arg, int pending)
1708 {
1709 	struct bstp_port *bp = (struct bstp_port *)arg;
1710 	struct bstp_state *bs = bp->bp_bs;
1711 	int age = 0;
1712 
1713 	BSTP_LOCK(bs);
1714 	switch (bp->bp_protover) {
1715 		case BSTP_PROTO_STP:
1716 			/* convert to seconds */
1717 			age = bp->bp_desg_fdelay / BSTP_TICK_VAL;
1718 			break;
1719 
1720 		case BSTP_PROTO_RSTP:
1721 			age = 0;
1722 			break;
1723 	}
1724 	BSTP_UNLOCK(bs);
1725 
1726 	if (bp->bp_active == 1 && bs->bs_rtage_cb != NULL)
1727 		(*bs->bs_rtage_cb)(bp->bp_ifp, age);
1728 
1729 	/* flush is complete */
1730 	BSTP_LOCK(bs);
1731 	bp->bp_fdbflush = 0;
1732 	BSTP_UNLOCK(bs);
1733 }
1734 
1735 void
1736 bstp_linkstate(struct ifnet *ifp, int state)
1737 {
1738 	struct bstp_state *bs;
1739 	struct bstp_port *bp;
1740 
1741 	/* search for the stp port */
1742 	mtx_lock(&bstp_list_mtx);
1743 	LIST_FOREACH(bs, &bstp_list, bs_list) {
1744 		BSTP_LOCK(bs);
1745 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1746 			if (bp->bp_ifp == ifp) {
1747 				bstp_ifupdstatus(bs, bp);
1748 				/* it only exists once so return */
1749 				BSTP_UNLOCK(bs);
1750 				mtx_unlock(&bstp_list_mtx);
1751 				return;
1752 			}
1753 		}
1754 		BSTP_UNLOCK(bs);
1755 	}
1756 	mtx_unlock(&bstp_list_mtx);
1757 }
1758 
1759 static void
1760 bstp_ifupdstatus(struct bstp_state *bs, struct bstp_port *bp)
1761 {
1762 	struct ifnet *ifp = bp->bp_ifp;
1763 	struct ifmediareq ifmr;
1764 	int error = 0;
1765 
1766 	BSTP_LOCK_ASSERT(bs);
1767 
1768 	bzero((char *)&ifmr, sizeof(ifmr));
1769 	error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr);
1770 
1771 	if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1772 		if (ifmr.ifm_status & IFM_ACTIVE) {
1773 			/* A full-duplex link is assumed to be point to point */
1774 			bp->bp_p2p_link = ifmr.ifm_active & IFM_FDX ? 1 : 0;
1775 
1776 			if (bp->bp_role == BSTP_ROLE_DISABLED)
1777 				bstp_enable_port(bs, bp);
1778 		} else {
1779 			if (bp->bp_role != BSTP_ROLE_DISABLED)
1780 				bstp_disable_port(bs, bp);
1781 		}
1782 		return;
1783 	}
1784 
1785 	if (bp->bp_infois != BSTP_INFO_DISABLED)
1786 		bstp_disable_port(bs, bp);
1787 }
1788 
1789 static void
1790 bstp_enable_port(struct bstp_state *bs, struct bstp_port *bp)
1791 {
1792 	bp->bp_infois = BSTP_INFO_AGED;
1793 	bstp_assign_roles(bs);
1794 }
1795 
1796 static void
1797 bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
1798 {
1799 	bp->bp_infois = BSTP_INFO_DISABLED;
1800 	bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
1801 	bstp_assign_roles(bs);
1802 }
1803 
1804 static void
1805 bstp_tick(void *arg)
1806 {
1807 	struct bstp_state *bs = arg;
1808 	struct bstp_port *bp;
1809 
1810 	BSTP_LOCK_ASSERT(bs);
1811 
1812 	/* slow timer to catch missed link events */
1813 	if (bstp_timer_expired(&bs->bs_link_timer)) {
1814 		LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1815 			bstp_ifupdstatus(bs, bp);
1816 		bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
1817 	}
1818 
1819 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1820 		/* no events need to happen for these */
1821 		bstp_timer_expired(&bp->bp_tc_timer);
1822 		bstp_timer_expired(&bp->bp_recent_root_timer);
1823 		bstp_timer_expired(&bp->bp_forward_delay_timer);
1824 		bstp_timer_expired(&bp->bp_recent_backup_timer);
1825 
1826 		if (bstp_timer_expired(&bp->bp_hello_timer))
1827 			bstp_hello_timer_expiry(bs, bp);
1828 
1829 		if (bstp_timer_expired(&bp->bp_message_age_timer))
1830 			bstp_message_age_expiry(bs, bp);
1831 
1832 		if (bstp_timer_expired(&bp->bp_migrate_delay_timer))
1833 			bstp_migrate_delay_expiry(bs, bp);
1834 
1835 		if (bstp_timer_expired(&bp->bp_edge_delay_timer))
1836 			bstp_edge_delay_expiry(bs, bp);
1837 
1838 		/* update the various state machines for the port */
1839 		bstp_update_state(bs, bp);
1840 
1841 		if (bp->bp_txcount > 0)
1842 			bp->bp_txcount--;
1843 	}
1844 
1845 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
1846 }
1847 
1848 static void
1849 bstp_timer_start(struct bstp_timer *t, uint16_t v)
1850 {
1851 	t->value = v;
1852 	t->active = 1;
1853 	t->latched = 0;
1854 }
1855 
1856 static void
1857 bstp_timer_stop(struct bstp_timer *t)
1858 {
1859 	t->value = 0;
1860 	t->active = 0;
1861 	t->latched = 0;
1862 }
1863 
1864 static void
1865 bstp_timer_latch(struct bstp_timer *t)
1866 {
1867 	t->latched = 1;
1868 	t->active = 1;
1869 }
1870 
1871 static int
1872 bstp_timer_expired(struct bstp_timer *t)
1873 {
1874 	if (t->active == 0 || t->latched)
1875 		return (0);
1876 	t->value -= BSTP_TICK_VAL;
1877 	if (t->value <= 0) {
1878 		bstp_timer_stop(t);
1879 		return (1);
1880 	}
1881 	return (0);
1882 }
1883 
1884 static void
1885 bstp_hello_timer_expiry(struct bstp_state *bs, struct bstp_port *bp)
1886 {
1887 	if ((bp->bp_flags & BSTP_PORT_NEWINFO) ||
1888 	    bp->bp_role == BSTP_ROLE_DESIGNATED ||
1889 	    (bp->bp_role == BSTP_ROLE_ROOT &&
1890 	     bp->bp_tc_timer.active == 1)) {
1891 		bstp_timer_start(&bp->bp_hello_timer, bp->bp_desg_htime);
1892 		bp->bp_flags |= BSTP_PORT_NEWINFO;
1893 		bstp_transmit(bs, bp);
1894 	}
1895 }
1896 
1897 static void
1898 bstp_message_age_expiry(struct bstp_state *bs, struct bstp_port *bp)
1899 {
1900 	if (bp->bp_infois == BSTP_INFO_RECIEVED) {
1901 		bp->bp_infois = BSTP_INFO_AGED;
1902 		bstp_assign_roles(bs);
1903 		DPRINTF("aged info on %s\n", bp->bp_ifp->if_xname);
1904 	}
1905 }
1906 
1907 static void
1908 bstp_migrate_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1909 {
1910 	bp->bp_flags |= BSTP_PORT_CANMIGRATE;
1911 }
1912 
1913 static void
1914 bstp_edge_delay_expiry(struct bstp_state *bs, struct bstp_port *bp)
1915 {
1916 	if ((bp->bp_flags & BSTP_PORT_AUTOEDGE) &&
1917 	    bp->bp_protover == BSTP_PROTO_RSTP && bp->bp_proposing &&
1918 	    bp->bp_role == BSTP_ROLE_DESIGNATED)
1919 		bp->bp_operedge = 1;
1920 }
1921 
1922 static int
1923 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
1924 {
1925 	int i, d;
1926 
1927 	for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
1928 		d = ((int)a[i]) - ((int)b[i]);
1929 	}
1930 
1931 	return (d);
1932 }
1933 
1934 /*
1935  * compare the bridge address component of the bridgeid
1936  */
1937 static int
1938 bstp_same_bridgeid(uint64_t id1, uint64_t id2)
1939 {
1940 	u_char addr1[ETHER_ADDR_LEN];
1941 	u_char addr2[ETHER_ADDR_LEN];
1942 
1943 	PV2ADDR(id1, addr1);
1944 	PV2ADDR(id2, addr2);
1945 
1946 	if (bstp_addr_cmp(addr1, addr2) == 0)
1947 		return (1);
1948 
1949 	return (0);
1950 }
1951 
1952 void
1953 bstp_reinit(struct bstp_state *bs)
1954 {
1955 	struct bstp_port *bp, *mbp;
1956 	u_char *e_addr;
1957 
1958 	BSTP_LOCK_ASSERT(bs);
1959 
1960 	mbp = NULL;
1961 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next) {
1962 		bp->bp_port_id = (bp->bp_priority << 8) |
1963 		    (bp->bp_ifp->if_index  & 0xfff);
1964 
1965 		if (mbp == NULL) {
1966 			mbp = bp;
1967 			continue;
1968 		}
1969 		if (bstp_addr_cmp(IF_LLADDR(bp->bp_ifp),
1970 		    IF_LLADDR(mbp->bp_ifp)) < 0) {
1971 			mbp = bp;
1972 			continue;
1973 		}
1974 	}
1975 	if (mbp == NULL) {
1976 		bstp_stop_locked(bs);
1977 		return;
1978 	}
1979 
1980 	e_addr = IF_LLADDR(mbp->bp_ifp);
1981 	bs->bs_bridge_pv.pv_dbridge_id =
1982 	    (((uint64_t)bs->bs_bridge_priority) << 48) |
1983 	    (((uint64_t)e_addr[0]) << 40) |
1984 	    (((uint64_t)e_addr[1]) << 32) |
1985 	    (((uint64_t)e_addr[2]) << 24) |
1986 	    (((uint64_t)e_addr[3]) << 16) |
1987 	    (((uint64_t)e_addr[4]) << 8) |
1988 	    (((uint64_t)e_addr[5]));
1989 
1990 	bs->bs_bridge_pv.pv_root_id = bs->bs_bridge_pv.pv_dbridge_id;
1991 	bs->bs_bridge_pv.pv_cost = 0;
1992 	bs->bs_bridge_pv.pv_dport_id = 0;
1993 	bs->bs_bridge_pv.pv_port_id = 0;
1994 
1995 	if (callout_pending(&bs->bs_bstpcallout) == 0)
1996 		callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
1997 
1998 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
1999 		bstp_ifupdstatus(bs, bp);
2000 
2001 	getmicrotime(&bs->bs_last_tc_time);
2002 	bstp_assign_roles(bs);
2003 	bstp_timer_start(&bs->bs_link_timer, BSTP_LINK_TIMER);
2004 }
2005 
2006 static int
2007 bstp_modevent(module_t mod, int type, void *data)
2008 {
2009 	switch (type) {
2010 	case MOD_LOAD:
2011 		mtx_init(&bstp_list_mtx, "bridgestp list", NULL, MTX_DEF);
2012 		LIST_INIT(&bstp_list);
2013 		bstp_linkstate_p = bstp_linkstate;
2014 		break;
2015 	case MOD_UNLOAD:
2016 		mtx_destroy(&bstp_list_mtx);
2017 		break;
2018 	default:
2019 		return (EOPNOTSUPP);
2020 	}
2021 	return (0);
2022 }
2023 
2024 static moduledata_t bstp_mod = {
2025 	"bridgestp",
2026 	bstp_modevent,
2027 	0
2028 };
2029 
2030 DECLARE_MODULE(bridgestp, bstp_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
2031 MODULE_VERSION(bridgestp, 1);
2032 
2033 void
2034 bstp_attach(struct bstp_state *bs, bstp_state_cb_t state_callback,
2035     bstp_rtage_cb_t rtage_callback)
2036 {
2037 	BSTP_LOCK_INIT(bs);
2038 	callout_init_mtx(&bs->bs_bstpcallout, &bs->bs_mtx, 0);
2039 	LIST_INIT(&bs->bs_bplist);
2040 
2041 	bs->bs_bridge_max_age = BSTP_DEFAULT_MAX_AGE;
2042 	bs->bs_bridge_htime = BSTP_DEFAULT_HELLO_TIME;
2043 	bs->bs_bridge_fdelay = BSTP_DEFAULT_FORWARD_DELAY;
2044 	bs->bs_bridge_priority = BSTP_DEFAULT_BRIDGE_PRIORITY;
2045 	bs->bs_hold_time = BSTP_DEFAULT_HOLD_TIME;
2046 	bs->bs_migration_delay = BSTP_DEFAULT_MIGRATE_DELAY;
2047 	bs->bs_txholdcount = BSTP_DEFAULT_HOLD_COUNT;
2048 	bs->bs_protover = BSTP_PROTO_RSTP;
2049 	bs->bs_state_cb = state_callback;
2050 	bs->bs_rtage_cb = rtage_callback;
2051 
2052 	getmicrotime(&bs->bs_last_tc_time);
2053 
2054 	mtx_lock(&bstp_list_mtx);
2055 	LIST_INSERT_HEAD(&bstp_list, bs, bs_list);
2056 	mtx_unlock(&bstp_list_mtx);
2057 }
2058 
2059 void
2060 bstp_detach(struct bstp_state *bs)
2061 {
2062 	KASSERT(LIST_EMPTY(&bs->bs_bplist), ("bstp still active"));
2063 
2064 	mtx_lock(&bstp_list_mtx);
2065 	LIST_REMOVE(bs, bs_list);
2066 	mtx_unlock(&bstp_list_mtx);
2067 	BSTP_LOCK_DESTROY(bs);
2068 }
2069 
2070 void
2071 bstp_init(struct bstp_state *bs)
2072 {
2073 	BSTP_LOCK(bs);
2074 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
2075 	bstp_reinit(bs);
2076 	BSTP_UNLOCK(bs);
2077 }
2078 
2079 void
2080 bstp_stop(struct bstp_state *bs)
2081 {
2082 	BSTP_LOCK(bs);
2083 	bstp_stop_locked(bs);
2084 	BSTP_UNLOCK(bs);
2085 }
2086 
2087 static void
2088 bstp_stop_locked(struct bstp_state *bs)
2089 {
2090 	struct bstp_port *bp;
2091 
2092 	BSTP_LOCK_ASSERT(bs);
2093 
2094 	LIST_FOREACH(bp, &bs->bs_bplist, bp_next)
2095 		bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2096 
2097 	callout_drain(&bs->bs_bstpcallout);
2098 	callout_stop(&bs->bs_bstpcallout);
2099 }
2100 
2101 int
2102 bstp_add(struct bstp_state *bs, struct bstp_port *bp, struct ifnet *ifp)
2103 {
2104 	KASSERT(bp->bp_active == 0, ("already a bstp member"));
2105 
2106 	switch (ifp->if_type) {
2107 		case IFT_ETHER:	/* These can do spanning tree. */
2108 			break;
2109 		default:
2110 			/* Nothing else can. */
2111 			return (EINVAL);
2112 	}
2113 
2114 	bzero(bp, sizeof(struct bstp_port));
2115 
2116 	BSTP_LOCK(bs);
2117 	bp->bp_ifp = ifp;
2118 	bp->bp_bs = bs;
2119 	bp->bp_priority = BSTP_DEFAULT_PORT_PRIORITY;
2120 	bp->bp_txcount = 0;
2121 	TASK_INIT(&bp->bp_statetask, 0, bstp_notify_state, bp);
2122 	TASK_INIT(&bp->bp_rtagetask, 0, bstp_notify_rtage, bp);
2123 
2124 	/* Init state */
2125 	bp->bp_infois = BSTP_INFO_DISABLED;
2126 	bp->bp_flags = BSTP_PORT_AUTOEDGE;
2127 	bstp_set_port_state(bp, BSTP_IFSTATE_DISCARDING);
2128 	bstp_set_port_proto(bp, bs->bs_protover);
2129 	bstp_set_port_role(bp, BSTP_ROLE_DISABLED);
2130 	bstp_set_port_tc(bp, BSTP_TCSTATE_INACTIVE);
2131 	bp->bp_path_cost = bstp_calc_path_cost(bp);
2132 
2133 	LIST_INSERT_HEAD(&bs->bs_bplist, bp, bp_next);
2134 
2135 	bp->bp_active = 1;
2136 	bp->bp_flags |= BSTP_PORT_NEWINFO;
2137 	bstp_reinit(bs);
2138 	bstp_update_roles(bs, bp);
2139 	BSTP_UNLOCK(bs);
2140 	return (0);
2141 }
2142 
2143 void
2144 bstp_delete(struct bstp_port *bp)
2145 {
2146 	struct bstp_state *bs = bp->bp_bs;
2147 
2148 	KASSERT(bp->bp_active == 1, ("not a bstp member"));
2149 
2150 	BSTP_LOCK(bs);
2151 	LIST_REMOVE(bp, bp_next);
2152 	bp->bp_bs = NULL;
2153 	bp->bp_active = 0;
2154 	bstp_reinit(bs);
2155 	BSTP_UNLOCK(bs);
2156 }
2157 
2158 /*
2159  * The bstp_port structure is about to be freed by the parent bridge.
2160  */
2161 void
2162 bstp_drain(struct bstp_port *bp)
2163 {
2164 	KASSERT(bp->bp_active == 0, ("port is still attached"));
2165 	taskqueue_drain(taskqueue_swi, &bp->bp_statetask);
2166 	taskqueue_drain(taskqueue_swi, &bp->bp_rtagetask);
2167 }
2168