xref: /illumos-gate/usr/src/uts/common/io/bridge.c (revision 598f4ceed9327d2d6c2325dd67cae3aa06f7fea6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * This module implements a STREAMS driver that provides layer-two (Ethernet)
29  * bridging functionality.  The STREAMS interface is used to provide
30  * observability (snoop/wireshark) and control, but not for interface plumbing.
31  */
32 
33 #include <sys/types.h>
34 #include <sys/bitmap.h>
35 #include <sys/cmn_err.h>
36 #include <sys/conf.h>
37 #include <sys/ddi.h>
38 #include <sys/errno.h>
39 #include <sys/kstat.h>
40 #include <sys/modctl.h>
41 #include <sys/note.h>
42 #include <sys/param.h>
43 #include <sys/policy.h>
44 #include <sys/sdt.h>
45 #include <sys/stat.h>
46 #include <sys/stream.h>
47 #include <sys/stropts.h>
48 #include <sys/strsun.h>
49 #include <sys/sunddi.h>
50 #include <sys/sysmacros.h>
51 #include <sys/systm.h>
52 #include <sys/time.h>
53 #include <sys/dlpi.h>
54 #include <sys/dls.h>
55 #include <sys/mac_ether.h>
56 #include <sys/mac_provider.h>
57 #include <sys/mac_client_priv.h>
58 #include <sys/mac_impl.h>
59 #include <sys/vlan.h>
60 #include <net/bridge.h>
61 #include <net/bridge_impl.h>
62 #include <net/trill.h>
63 #include <sys/dld_ioc.h>
64 
65 /*
66  * Locks and reference counts: object lifetime and design.
67  *
68  * bridge_mac_t
69  *   Bridge mac (snoop) instances are in bmac_list, which is protected by
70  *   bmac_rwlock.  They're allocated by bmac_alloc and freed by bridge_timer().
71  *   Every bridge_inst_t has a single bridge_mac_t, but when bridge_inst_t goes
72  *   away, the bridge_mac_t remains until either all of the users go away
73  *   (detected by a timer) or until the instance is picked up again by the same
74  *   bridge starting back up.
75  *
76  * bridge_inst_t
77  *   Bridge instances are in inst_list, which is protected by inst_lock.
78  *   They're allocated by inst_alloc() and freed by inst_free().  After
79  *   allocation, an instance is placed in inst_list, and the reference count is
80  *   incremented to represent this.  That reference is decremented when the
81  *   BIF_SHUTDOWN flag is set, and no new increments may occur.  When the last
82  *   reference is freed, the instance is removed from the list.
83  *
84  *   Bridge instances have lists of links and an AVL tree of forwarding
85  *   entries.  Each of these structures holds one reference on the bridge
86  *   instance.  These lists and tree are protected by bi_rwlock.
87  *
88  * bridge_stream_t
89  *   Bridge streams are allocated by stream_alloc() and freed by stream_free().
90  *   These streams are created when "bridged" opens /dev/bridgectl, and are
91  *   used to create new bridge instances (via BRIOC_NEWBRIDGE) and control the
92  *   links on the bridge.  When a stream closes, the bridge instance created is
93  *   destroyed.  There's at most one bridge instance for a given control
94  *   stream.
95  *
96  * bridge_link_t
97  *   Links are allocated by bridge_add_link() and freed by link_free().  The
98  *   bi_links list holds a reference to the link.  When the BLF_DELETED flag is
99  *   set, that reference is dropped.  The link isn't removed from the list
100  *   until the last reference drops.  Each forwarding entry that uses a given
101  *   link holds a reference, as does each thread transmitting a packet via the
102  *   link.  The MAC layer calls in via bridge_ref_cb() to hold a reference on
103  *   a link when transmitting.
104  *
105  *   It's important that once BLF_DELETED is set, there's no way for the
106  *   reference count to increase again.  If it can, then the link may be
107  *   double-freed.  The BLF_FREED flag is intended for use with assertions to
108  *   guard against this in testing.
109  *
110  * bridge_fwd_t
111  *   Bridge forwarding entries are allocated by bridge_recv_cb() and freed by
112  *   fwd_free().  The bi_fwd AVL tree holds one reference to the entry.  Unlike
113  *   other data structures, the reference is dropped when the entry is removed
114  *   from the tree by fwd_delete(), and the BFF_INTREE flag is removed.  Each
115  *   thread that's forwarding a packet to a known destination holds a reference
116  *   to a forwarding entry.
117  *
118  * TRILL notes:
119  *
120  *   The TRILL module does all of its I/O through bridging.  It uses references
121  *   on the bridge_inst_t and bridge_link_t structures, and has seven entry
122  *   points and four callbacks.  One entry point is for setting the callbacks
123  *   (bridge_trill_register_cb).  There are four entry points for taking bridge
124  *   and link references (bridge_trill_{br,ln}{ref,unref}).  The final two
125  *   entry points are for decapsulated packets from TRILL (bridge_trill_decaps)
126  *   that need to be bridged locally, and for TRILL-encapsulated output packets
127  *   (bridge_trill_output).
128  *
129  *   The four callbacks comprise two notification functions for bridges and
130  *   links being deleted, one function for raw received TRILL packets, and one
131  *   for bridge output to non-local TRILL destinations (tunnel entry).
132  */
133 
134 /*
135  * Ethernet reserved multicast addresses for TRILL; used also in TRILL module.
136  */
137 const uint8_t all_isis_rbridges[] = ALL_ISIS_RBRIDGES;
138 static const uint8_t all_esadi_rbridges[] = ALL_ESADI_RBRIDGES;
139 const uint8_t bridge_group_address[] = BRIDGE_GROUP_ADDRESS;
140 
141 static const char *inst_kstats_list[] = { KSINST_NAMES };
142 static const char *link_kstats_list[] = { KSLINK_NAMES };
143 
144 #define	KREF(p, m, vn)	p->m.vn.value.ui64
145 #define	KINCR(p, m, vn)	++KREF(p, m, vn)
146 #define	KDECR(p, m, vn)	--KREF(p, m, vn)
147 
148 #define	KIPINCR(p, vn)	KINCR(p, bi_kstats, vn)
149 #define	KIPDECR(p, vn)	KDECR(p, bi_kstats, vn)
150 #define	KLPINCR(p, vn)	KINCR(p, bl_kstats, vn)
151 
152 #define	KIINCR(vn)	KIPINCR(bip, vn)
153 #define	KIDECR(vn)	KIPDECR(bip, vn)
154 #define	KLINCR(vn)	KLPINCR(blp, vn)
155 
156 #define	Dim(x)		(sizeof (x) / sizeof (*(x)))
157 
158 /* Amount of overhead added when encapsulating with VLAN headers */
159 #define	VLAN_INCR	(sizeof (struct ether_vlan_header) -	\
160 			sizeof (struct ether_header))
161 
162 static dev_info_t *bridge_dev_info;
163 static major_t bridge_major;
164 static ddi_taskq_t *bridge_taskq;
165 
166 /*
167  * These are the bridge instance management data structures.  The mutex lock
168  * protects the list of bridge instances.  A reference count is then used on
169  * each instance to determine when to free it.  We use mac_minor_hold() to
170  * allocate minor_t values, which are used both for self-cloning /dev/net/
171  * device nodes as well as client streams.  Minor node 0 is reserved for the
172  * allocation control node.
173  */
174 static list_t inst_list;
175 static kcondvar_t inst_cv;		/* Allows us to wait for shutdown */
176 static kmutex_t inst_lock;
177 
178 static krwlock_t bmac_rwlock;
179 static list_t bmac_list;
180 
181 /* Wait for taskq entries that use STREAMS */
182 static kcondvar_t stream_ref_cv;
183 static kmutex_t stream_ref_lock;
184 
185 static timeout_id_t bridge_timerid;
186 static clock_t bridge_scan_interval;
187 static clock_t bridge_fwd_age;
188 
189 static bridge_inst_t *bridge_find_name(const char *);
190 static void bridge_timer(void *);
191 static void bridge_unref(bridge_inst_t *);
192 
193 static const uint8_t zero_addr[ETHERADDRL] = { 0 };
194 
195 /* Global TRILL linkage */
196 static trill_recv_pkt_t trill_recv_fn;
197 static trill_encap_pkt_t trill_encap_fn;
198 static trill_br_dstr_t trill_brdstr_fn;
199 static trill_ln_dstr_t trill_lndstr_fn;
200 
201 /* special settings to accommodate DLD flow control; see dld_str.c */
202 static struct module_info bridge_dld_modinfo = {
203 	0,			/* mi_idnum */
204 	BRIDGE_DEV_NAME,	/* mi_idname */
205 	0,			/* mi_minpsz */
206 	INFPSZ,			/* mi_maxpsz */
207 	1,			/* mi_hiwat */
208 	0			/* mi_lowat */
209 };
210 
211 static struct qinit bridge_dld_rinit = {
212 	NULL,			/* qi_putp */
213 	NULL,			/* qi_srvp */
214 	dld_open,		/* qi_qopen */
215 	dld_close,		/* qi_qclose */
216 	NULL,			/* qi_qadmin */
217 	&bridge_dld_modinfo,	/* qi_minfo */
218 	NULL			/* qi_mstat */
219 };
220 
221 static struct qinit bridge_dld_winit = {
222 	(int (*)())dld_wput,	/* qi_putp */
223 	(int (*)())dld_wsrv,	/* qi_srvp */
224 	NULL,			/* qi_qopen */
225 	NULL,			/* qi_qclose */
226 	NULL,			/* qi_qadmin */
227 	&bridge_dld_modinfo,	/* qi_minfo */
228 	NULL			/* qi_mstat */
229 };
230 
231 static int bridge_ioc_listfwd(void *, intptr_t, int, cred_t *, int *);
232 
233 /* GLDv3 control ioctls used by Bridging */
234 static dld_ioc_info_t bridge_ioc_list[] = {
235 	{BRIDGE_IOC_LISTFWD, DLDCOPYINOUT, sizeof (bridge_listfwd_t),
236 	    bridge_ioc_listfwd, NULL},
237 };
238 
239 /*
240  * Given a bridge mac pointer, get a ref-held pointer to the corresponding
241  * bridge instance, if any.  We must hold the global bmac_rwlock so that
242  * bm_inst doesn't slide out from under us.
243  */
244 static bridge_inst_t *
245 mac_to_inst(const bridge_mac_t *bmp)
246 {
247 	bridge_inst_t *bip;
248 
249 	rw_enter(&bmac_rwlock, RW_READER);
250 	if ((bip = bmp->bm_inst) != NULL)
251 		atomic_inc_uint(&bip->bi_refs);
252 	rw_exit(&bmac_rwlock);
253 	return (bip);
254 }
255 
256 static void
257 link_sdu_fail(bridge_link_t *blp, boolean_t failed, mblk_t **mlist)
258 {
259 	mblk_t *mp;
260 	bridge_ctl_t *bcp;
261 	bridge_link_t *blcmp;
262 	bridge_inst_t *bip;
263 	bridge_mac_t *bmp;
264 
265 	if (failed) {
266 		if (blp->bl_flags & BLF_SDUFAIL)
267 			return;
268 		blp->bl_flags |= BLF_SDUFAIL;
269 	} else {
270 		if (!(blp->bl_flags & BLF_SDUFAIL))
271 			return;
272 		blp->bl_flags &= ~BLF_SDUFAIL;
273 	}
274 
275 	/*
276 	 * If this link is otherwise up, then check if there are any other
277 	 * non-failed non-down links.  If not, then we control the state of the
278 	 * whole bridge.
279 	 */
280 	bip = blp->bl_inst;
281 	bmp = bip->bi_mac;
282 	if (blp->bl_linkstate != LINK_STATE_DOWN) {
283 		for (blcmp = list_head(&bip->bi_links); blcmp != NULL;
284 		    blcmp = list_next(&bip->bi_links, blcmp)) {
285 			if (blp != blcmp &&
286 			    !(blcmp->bl_flags & (BLF_DELETED|BLF_SDUFAIL)) &&
287 			    blcmp->bl_linkstate != LINK_STATE_DOWN)
288 				break;
289 		}
290 		if (blcmp == NULL) {
291 			bmp->bm_linkstate = failed ? LINK_STATE_DOWN :
292 			    LINK_STATE_UP;
293 			mac_link_redo(bmp->bm_mh, bmp->bm_linkstate);
294 		}
295 	}
296 
297 	/*
298 	 * If we're becoming failed, then the link's current true state needs
299 	 * to be reflected upwards to this link's clients.  If we're becoming
300 	 * unfailed, then we get the state of the bridge instead on all
301 	 * clients.
302 	 */
303 	if (failed) {
304 		if (bmp->bm_linkstate != blp->bl_linkstate)
305 			mac_link_redo(blp->bl_mh, blp->bl_linkstate);
306 	} else {
307 		mac_link_redo(blp->bl_mh, bmp->bm_linkstate);
308 	}
309 
310 	/* get the current mblk we're going to send up */
311 	if ((mp = blp->bl_lfailmp) == NULL &&
312 	    (mp = allocb(sizeof (bridge_ctl_t), BPRI_MED)) == NULL)
313 		return;
314 
315 	/* get a new one for next time */
316 	blp->bl_lfailmp = allocb(sizeof (bridge_ctl_t), BPRI_MED);
317 
318 	/* if none for next time, then report only failures */
319 	if (blp->bl_lfailmp == NULL && !failed) {
320 		blp->bl_lfailmp = mp;
321 		return;
322 	}
323 
324 	/* LINTED: alignment */
325 	bcp = (bridge_ctl_t *)mp->b_rptr;
326 	bcp->bc_linkid = blp->bl_linkid;
327 	bcp->bc_failed = failed;
328 	mp->b_wptr = (uchar_t *)(bcp + 1);
329 	mp->b_next = *mlist;
330 	*mlist = mp;
331 }
332 
333 /*
334  * Send control messages (link SDU changes) using the stream to the
335  * bridge instance daemon.
336  */
337 static void
338 send_up_messages(bridge_inst_t *bip, mblk_t *mp)
339 {
340 	mblk_t *mnext;
341 	queue_t *rq;
342 
343 	rq = bip->bi_control->bs_wq;
344 	rq = OTHERQ(rq);
345 	while (mp != NULL) {
346 		mnext = mp->b_next;
347 		mp->b_next = NULL;
348 		putnext(rq, mp);
349 		mp = mnext;
350 	}
351 }
352 
353 /* ARGSUSED */
354 static int
355 bridge_m_getstat(void *arg, uint_t stat, uint64_t *val)
356 {
357 	return (ENOTSUP);
358 }
359 
360 static int
361 bridge_m_start(void *arg)
362 {
363 	bridge_mac_t *bmp = arg;
364 
365 	bmp->bm_flags |= BMF_STARTED;
366 	return (0);
367 }
368 
369 static void
370 bridge_m_stop(void *arg)
371 {
372 	bridge_mac_t *bmp = arg;
373 
374 	bmp->bm_flags &= ~BMF_STARTED;
375 }
376 
377 /* ARGSUSED */
378 static int
379 bridge_m_setpromisc(void *arg, boolean_t on)
380 {
381 	return (0);
382 }
383 
384 /* ARGSUSED */
385 static int
386 bridge_m_multicst(void *arg, boolean_t add, const uint8_t *mca)
387 {
388 	return (0);
389 }
390 
391 /* ARGSUSED */
392 static int
393 bridge_m_unicst(void *arg, const uint8_t *macaddr)
394 {
395 	return (ENOTSUP);
396 }
397 
398 static mblk_t *
399 bridge_m_tx(void *arg, mblk_t *mp)
400 {
401 	_NOTE(ARGUNUSED(arg));
402 	freemsgchain(mp);
403 	return (NULL);
404 }
405 
406 /* ARGSUSED */
407 static int
408 bridge_ioc_listfwd(void *karg, intptr_t arg, int mode, cred_t *cred, int *rvalp)
409 {
410 	bridge_listfwd_t *blf = karg;
411 	bridge_inst_t *bip;
412 	bridge_fwd_t *bfp, match;
413 	avl_index_t where;
414 
415 	bip = bridge_find_name(blf->blf_name);
416 	if (bip == NULL)
417 		return (ENOENT);
418 
419 	bcopy(blf->blf_dest, match.bf_dest, ETHERADDRL);
420 	match.bf_flags |= BFF_VLANLOCAL;
421 	rw_enter(&bip->bi_rwlock, RW_READER);
422 	if ((bfp = avl_find(&bip->bi_fwd, &match, &where)) == NULL)
423 		bfp = avl_nearest(&bip->bi_fwd, where, AVL_AFTER);
424 	else
425 		bfp = AVL_NEXT(&bip->bi_fwd, bfp);
426 	if (bfp == NULL) {
427 		bzero(blf, sizeof (*blf));
428 	} else {
429 		bcopy(bfp->bf_dest, blf->blf_dest, ETHERADDRL);
430 		blf->blf_trill_nick = bfp->bf_trill_nick;
431 		blf->blf_ms_age =
432 		    drv_hztousec(ddi_get_lbolt() - bfp->bf_lastheard) / 1000;
433 		blf->blf_is_local =
434 		    (bfp->bf_flags & BFF_LOCALADDR) != 0;
435 		blf->blf_linkid = bfp->bf_links[0]->bl_linkid;
436 	}
437 	rw_exit(&bip->bi_rwlock);
438 	bridge_unref(bip);
439 	return (0);
440 }
441 
442 static int
443 bridge_m_setprop(void *arg, const char *pr_name, mac_prop_id_t pr_num,
444     uint_t pr_valsize, const void *pr_val)
445 {
446 	bridge_mac_t *bmp = arg;
447 	bridge_inst_t *bip;
448 	bridge_link_t *blp;
449 	int err;
450 	uint_t maxsdu;
451 	mblk_t *mlist;
452 
453 	_NOTE(ARGUNUSED(pr_name));
454 	switch (pr_num) {
455 	case MAC_PROP_MTU:
456 		if (pr_valsize < sizeof (bmp->bm_maxsdu)) {
457 			err = EINVAL;
458 			break;
459 		}
460 		(void) bcopy(pr_val, &maxsdu, sizeof (maxsdu));
461 		if (maxsdu == bmp->bm_maxsdu) {
462 			err = 0;
463 		} else if ((bip = mac_to_inst(bmp)) == NULL) {
464 			err = ENXIO;
465 		} else {
466 			rw_enter(&bip->bi_rwlock, RW_WRITER);
467 			mlist = NULL;
468 			for (blp = list_head(&bip->bi_links); blp != NULL;
469 			    blp = list_next(&bip->bi_links, blp)) {
470 				if (blp->bl_flags & BLF_DELETED)
471 					continue;
472 				if (blp->bl_maxsdu == maxsdu)
473 					link_sdu_fail(blp, B_FALSE, &mlist);
474 				else if (blp->bl_maxsdu == bmp->bm_maxsdu)
475 					link_sdu_fail(blp, B_TRUE, &mlist);
476 			}
477 			rw_exit(&bip->bi_rwlock);
478 			bmp->bm_maxsdu = maxsdu;
479 			(void) mac_maxsdu_update(bmp->bm_mh, maxsdu);
480 			send_up_messages(bip, mlist);
481 			bridge_unref(bip);
482 			err = 0;
483 		}
484 		break;
485 
486 	default:
487 		err = ENOTSUP;
488 		break;
489 	}
490 	return (err);
491 }
492 
493 static int
494 bridge_m_getprop(void *arg, const char *pr_name, mac_prop_id_t pr_num,
495     uint_t pr_valsize, void *pr_val)
496 {
497 	bridge_mac_t *bmp = arg;
498 	int err = 0;
499 
500 	_NOTE(ARGUNUSED(pr_name));
501 	switch (pr_num) {
502 	case MAC_PROP_STATUS:
503 		ASSERT(pr_valsize >= sizeof (bmp->bm_linkstate));
504 		bcopy(&bmp->bm_linkstate, pr_val, sizeof (&bmp->bm_linkstate));
505 		break;
506 
507 	default:
508 		err = ENOTSUP;
509 		break;
510 	}
511 	return (err);
512 }
513 
514 static void
515 bridge_m_propinfo(void *arg, const char *pr_name, mac_prop_id_t pr_num,
516     mac_prop_info_handle_t prh)
517 {
518 	bridge_mac_t *bmp = arg;
519 
520 	_NOTE(ARGUNUSED(pr_name));
521 
522 	switch (pr_num) {
523 	case MAC_PROP_MTU:
524 		mac_prop_info_set_range_uint32(prh, bmp->bm_maxsdu,
525 		    bmp->bm_maxsdu);
526 		break;
527 	case MAC_PROP_STATUS:
528 		mac_prop_info_set_perm(prh, MAC_PROP_PERM_READ);
529 		break;
530 	}
531 }
532 
533 static mac_callbacks_t bridge_m_callbacks = {
534 	MC_SETPROP | MC_GETPROP | MC_PROPINFO,
535 	bridge_m_getstat,
536 	bridge_m_start,
537 	bridge_m_stop,
538 	bridge_m_setpromisc,
539 	bridge_m_multicst,
540 	bridge_m_unicst,
541 	bridge_m_tx,
542 	NULL,	/* reserved */
543 	NULL,	/* ioctl */
544 	NULL,	/* getcapab */
545 	NULL,	/* open */
546 	NULL,	/* close */
547 	bridge_m_setprop,
548 	bridge_m_getprop,
549 	bridge_m_propinfo
550 };
551 
552 /*
553  * Create kstats from a list.
554  */
555 static kstat_t *
556 kstat_setup(kstat_named_t *knt, const char **names, int nstat,
557     const char *unitname)
558 {
559 	kstat_t *ksp;
560 	int i;
561 
562 	for (i = 0; i < nstat; i++)
563 		kstat_named_init(&knt[i], names[i], KSTAT_DATA_UINT64);
564 
565 	ksp = kstat_create_zone(BRIDGE_DEV_NAME, 0, unitname, "net",
566 	    KSTAT_TYPE_NAMED, nstat, KSTAT_FLAG_VIRTUAL, GLOBAL_ZONEID);
567 	if (ksp != NULL) {
568 		ksp->ks_data = knt;
569 		kstat_install(ksp);
570 	}
571 	return (ksp);
572 }
573 
574 /*
575  * Find an existing bridge_mac_t structure or allocate a new one for the given
576  * bridge instance.  This creates the mac driver instance that snoop can use.
577  */
578 static int
579 bmac_alloc(bridge_inst_t *bip, bridge_mac_t **bmacp)
580 {
581 	bridge_mac_t *bmp, *bnew;
582 	mac_register_t *mac;
583 	int err;
584 
585 	*bmacp = NULL;
586 	if ((mac = mac_alloc(MAC_VERSION)) == NULL)
587 		return (EINVAL);
588 
589 	bnew = kmem_zalloc(sizeof (*bnew), KM_SLEEP);
590 
591 	rw_enter(&bmac_rwlock, RW_WRITER);
592 	for (bmp = list_head(&bmac_list); bmp != NULL;
593 	    bmp = list_next(&bmac_list, bmp)) {
594 		if (strcmp(bip->bi_name, bmp->bm_name) == 0) {
595 			ASSERT(bmp->bm_inst == NULL);
596 			bmp->bm_inst = bip;
597 			rw_exit(&bmac_rwlock);
598 			kmem_free(bnew, sizeof (*bnew));
599 			mac_free(mac);
600 			*bmacp = bmp;
601 			return (0);
602 		}
603 	}
604 
605 	mac->m_type_ident = MAC_PLUGIN_IDENT_ETHER;
606 	mac->m_driver = bnew;
607 	mac->m_dip = bridge_dev_info;
608 	mac->m_instance = (uint_t)-1;
609 	mac->m_src_addr = (uint8_t *)zero_addr;
610 	mac->m_callbacks = &bridge_m_callbacks;
611 
612 	/*
613 	 * Note that the SDU limits are irrelevant, as nobody transmits on the
614 	 * bridge node itself.  It's mainly for monitoring but we allow
615 	 * setting the bridge MTU for quick transition of all links part of the
616 	 * bridge to a new MTU.
617 	 */
618 	mac->m_min_sdu = 1;
619 	mac->m_max_sdu = 1500;
620 	err = mac_register(mac, &bnew->bm_mh);
621 	mac_free(mac);
622 	if (err != 0) {
623 		rw_exit(&bmac_rwlock);
624 		kmem_free(bnew, sizeof (*bnew));
625 		return (err);
626 	}
627 
628 	bnew->bm_inst = bip;
629 	(void) strcpy(bnew->bm_name, bip->bi_name);
630 	if (list_is_empty(&bmac_list)) {
631 		bridge_timerid = timeout(bridge_timer, NULL,
632 		    bridge_scan_interval);
633 	}
634 	list_insert_tail(&bmac_list, bnew);
635 	rw_exit(&bmac_rwlock);
636 
637 	/*
638 	 * Mark the MAC as unable to go "active" so that only passive clients
639 	 * (such as snoop) can bind to it.
640 	 */
641 	mac_no_active(bnew->bm_mh);
642 	*bmacp = bnew;
643 	return (0);
644 }
645 
646 /*
647  * Disconnect the given bridge_mac_t from its bridge instance.  The bridge
648  * instance is going away.  The mac instance can't go away until the clients
649  * are gone (see bridge_timer).
650  */
651 static void
652 bmac_disconnect(bridge_mac_t *bmp)
653 {
654 	bridge_inst_t *bip;
655 
656 	bmp->bm_linkstate = LINK_STATE_DOWN;
657 	mac_link_redo(bmp->bm_mh, LINK_STATE_DOWN);
658 
659 	rw_enter(&bmac_rwlock, RW_READER);
660 	bip = bmp->bm_inst;
661 	bip->bi_mac = NULL;
662 	bmp->bm_inst = NULL;
663 	rw_exit(&bmac_rwlock);
664 }
665 
666 /* This is used by the avl trees to sort forwarding table entries */
667 static int
668 fwd_compare(const void *addr1, const void *addr2)
669 {
670 	const bridge_fwd_t *fwd1 = addr1;
671 	const bridge_fwd_t *fwd2 = addr2;
672 	int diff = memcmp(fwd1->bf_dest, fwd2->bf_dest, ETHERADDRL);
673 
674 	if (diff != 0)
675 		return (diff > 0 ? 1 : -1);
676 
677 	if ((fwd1->bf_flags ^ fwd2->bf_flags) & BFF_VLANLOCAL) {
678 		if (fwd1->bf_vlanid > fwd2->bf_vlanid)
679 			return (1);
680 		else if (fwd1->bf_vlanid < fwd2->bf_vlanid)
681 			return (-1);
682 	}
683 	return (0);
684 }
685 
686 static void
687 inst_free(bridge_inst_t *bip)
688 {
689 	ASSERT(bip->bi_mac == NULL);
690 	rw_destroy(&bip->bi_rwlock);
691 	list_destroy(&bip->bi_links);
692 	cv_destroy(&bip->bi_linkwait);
693 	avl_destroy(&bip->bi_fwd);
694 	if (bip->bi_ksp != NULL)
695 		kstat_delete(bip->bi_ksp);
696 	kmem_free(bip, sizeof (*bip));
697 }
698 
699 static bridge_inst_t *
700 inst_alloc(const char *bridge)
701 {
702 	bridge_inst_t *bip;
703 
704 	bip = kmem_zalloc(sizeof (*bip), KM_SLEEP);
705 	bip->bi_refs = 1;
706 	(void) strcpy(bip->bi_name, bridge);
707 	rw_init(&bip->bi_rwlock, NULL, RW_DRIVER, NULL);
708 	list_create(&bip->bi_links, sizeof (bridge_link_t),
709 	    offsetof(bridge_link_t, bl_node));
710 	cv_init(&bip->bi_linkwait, NULL, CV_DRIVER, NULL);
711 	avl_create(&bip->bi_fwd, fwd_compare, sizeof (bridge_fwd_t),
712 	    offsetof(bridge_fwd_t, bf_node));
713 	return (bip);
714 }
715 
716 static bridge_inst_t *
717 bridge_find_name(const char *bridge)
718 {
719 	bridge_inst_t *bip;
720 
721 	mutex_enter(&inst_lock);
722 	for (bip = list_head(&inst_list); bip != NULL;
723 	    bip = list_next(&inst_list, bip)) {
724 		if (!(bip->bi_flags & BIF_SHUTDOWN) &&
725 		    strcmp(bridge, bip->bi_name) == 0) {
726 			atomic_inc_uint(&bip->bi_refs);
727 			break;
728 		}
729 	}
730 	mutex_exit(&inst_lock);
731 
732 	return (bip);
733 }
734 
735 static int
736 bridge_create(datalink_id_t linkid, const char *bridge, bridge_inst_t **bipc,
737     cred_t *cred)
738 {
739 	bridge_inst_t *bip, *bipnew;
740 	bridge_mac_t *bmp = NULL;
741 	int err;
742 
743 	*bipc = NULL;
744 	bipnew = inst_alloc(bridge);
745 
746 	mutex_enter(&inst_lock);
747 lookup_retry:
748 	for (bip = list_head(&inst_list); bip != NULL;
749 	    bip = list_next(&inst_list, bip)) {
750 		if (strcmp(bridge, bip->bi_name) == 0)
751 			break;
752 	}
753 
754 	/* This should not take long; if it does, we've got a design problem */
755 	if (bip != NULL && (bip->bi_flags & BIF_SHUTDOWN)) {
756 		cv_wait(&inst_cv, &inst_lock);
757 		goto lookup_retry;
758 	}
759 
760 	if (bip == NULL) {
761 		bip = bipnew;
762 		bipnew = NULL;
763 		list_insert_tail(&inst_list, bip);
764 	}
765 
766 	mutex_exit(&inst_lock);
767 	if (bipnew != NULL) {
768 		inst_free(bipnew);
769 		return (EEXIST);
770 	}
771 
772 	bip->bi_ksp = kstat_setup((kstat_named_t *)&bip->bi_kstats,
773 	    inst_kstats_list, Dim(inst_kstats_list), bip->bi_name);
774 
775 	err = bmac_alloc(bip, &bmp);
776 	if ((bip->bi_mac = bmp) == NULL)
777 		goto fail_create;
778 
779 	/*
780 	 * bm_inst is set, so the timer cannot yank the DLS rug from under us.
781 	 * No extra locking is needed here.
782 	 */
783 	if (!(bmp->bm_flags & BMF_DLS)) {
784 		err = dls_devnet_create(bmp->bm_mh, linkid, crgetzoneid(cred));
785 		if (err != 0)
786 			goto fail_create;
787 		bmp->bm_flags |= BMF_DLS;
788 	}
789 
790 	bip->bi_dev = makedevice(bridge_major, mac_minor(bmp->bm_mh));
791 	*bipc = bip;
792 	return (0);
793 
794 fail_create:
795 	ASSERT(bip->bi_trilldata == NULL);
796 	bip->bi_flags |= BIF_SHUTDOWN;
797 	bridge_unref(bip);
798 	return (err);
799 }
800 
801 static void
802 bridge_unref(bridge_inst_t *bip)
803 {
804 	if (atomic_dec_uint_nv(&bip->bi_refs) == 0) {
805 		ASSERT(bip->bi_flags & BIF_SHUTDOWN);
806 		/* free up mac for reuse before leaving global list */
807 		if (bip->bi_mac != NULL)
808 			bmac_disconnect(bip->bi_mac);
809 		mutex_enter(&inst_lock);
810 		list_remove(&inst_list, bip);
811 		cv_broadcast(&inst_cv);
812 		mutex_exit(&inst_lock);
813 		inst_free(bip);
814 	}
815 }
816 
817 /*
818  * Stream instances are used only for allocating bridges and serving as a
819  * control node.  They serve no data-handling function.
820  */
821 static bridge_stream_t *
822 stream_alloc(void)
823 {
824 	bridge_stream_t *bsp;
825 	minor_t mn;
826 
827 	if ((mn = mac_minor_hold(B_FALSE)) == 0)
828 		return (NULL);
829 	bsp = kmem_zalloc(sizeof (*bsp), KM_SLEEP);
830 	bsp->bs_minor = mn;
831 	return (bsp);
832 }
833 
834 static void
835 stream_free(bridge_stream_t *bsp)
836 {
837 	mac_minor_rele(bsp->bs_minor);
838 	kmem_free(bsp, sizeof (*bsp));
839 }
840 
841 /* Reference hold/release functions for STREAMS-related taskq */
842 static void
843 stream_ref(bridge_stream_t *bsp)
844 {
845 	mutex_enter(&stream_ref_lock);
846 	bsp->bs_taskq_cnt++;
847 	mutex_exit(&stream_ref_lock);
848 }
849 
850 static void
851 stream_unref(bridge_stream_t *bsp)
852 {
853 	mutex_enter(&stream_ref_lock);
854 	if (--bsp->bs_taskq_cnt == 0)
855 		cv_broadcast(&stream_ref_cv);
856 	mutex_exit(&stream_ref_lock);
857 }
858 
859 static void
860 link_free(bridge_link_t *blp)
861 {
862 	bridge_inst_t *bip = blp->bl_inst;
863 
864 	ASSERT(!(blp->bl_flags & BLF_FREED));
865 	blp->bl_flags |= BLF_FREED;
866 	if (blp->bl_ksp != NULL)
867 		kstat_delete(blp->bl_ksp);
868 	if (blp->bl_lfailmp != NULL)
869 		freeb(blp->bl_lfailmp);
870 	cv_destroy(&blp->bl_trillwait);
871 	mutex_destroy(&blp->bl_trilllock);
872 	kmem_free(blp, sizeof (*blp));
873 	/* Don't unreference the bridge until the MAC is closed */
874 	bridge_unref(bip);
875 }
876 
877 static void
878 link_unref(bridge_link_t *blp)
879 {
880 	if (atomic_dec_uint_nv(&blp->bl_refs) == 0) {
881 		bridge_inst_t *bip = blp->bl_inst;
882 
883 		ASSERT(blp->bl_flags & BLF_DELETED);
884 		rw_enter(&bip->bi_rwlock, RW_WRITER);
885 		if (blp->bl_flags & BLF_LINK_ADDED)
886 			list_remove(&bip->bi_links, blp);
887 		rw_exit(&bip->bi_rwlock);
888 		if (bip->bi_trilldata != NULL && list_is_empty(&bip->bi_links))
889 			cv_broadcast(&bip->bi_linkwait);
890 		link_free(blp);
891 	}
892 }
893 
894 static bridge_fwd_t *
895 fwd_alloc(const uint8_t *addr, uint_t nlinks, uint16_t nick)
896 {
897 	bridge_fwd_t *bfp;
898 
899 	bfp = kmem_zalloc(sizeof (*bfp) + (nlinks * sizeof (bridge_link_t *)),
900 	    KM_NOSLEEP);
901 	if (bfp != NULL) {
902 		bcopy(addr, bfp->bf_dest, ETHERADDRL);
903 		bfp->bf_lastheard = ddi_get_lbolt();
904 		bfp->bf_maxlinks = nlinks;
905 		bfp->bf_links = (bridge_link_t **)(bfp + 1);
906 		bfp->bf_trill_nick = nick;
907 	}
908 	return (bfp);
909 }
910 
911 static bridge_fwd_t *
912 fwd_find(bridge_inst_t *bip, const uint8_t *addr, uint16_t vlanid)
913 {
914 	bridge_fwd_t *bfp, *vbfp;
915 	bridge_fwd_t match;
916 
917 	bcopy(addr, match.bf_dest, ETHERADDRL);
918 	match.bf_flags = 0;
919 	rw_enter(&bip->bi_rwlock, RW_READER);
920 	if ((bfp = avl_find(&bip->bi_fwd, &match, NULL)) != NULL) {
921 		if (bfp->bf_vlanid != vlanid && bfp->bf_vcnt > 0) {
922 			match.bf_vlanid = vlanid;
923 			match.bf_flags = BFF_VLANLOCAL;
924 			vbfp = avl_find(&bip->bi_fwd, &match, NULL);
925 			if (vbfp != NULL)
926 				bfp = vbfp;
927 		}
928 		atomic_inc_uint(&bfp->bf_refs);
929 	}
930 	rw_exit(&bip->bi_rwlock);
931 	return (bfp);
932 }
933 
934 static void
935 fwd_free(bridge_fwd_t *bfp)
936 {
937 	uint_t i;
938 	bridge_inst_t *bip = bfp->bf_links[0]->bl_inst;
939 
940 	KIDECR(bki_count);
941 	for (i = 0; i < bfp->bf_nlinks; i++)
942 		link_unref(bfp->bf_links[i]);
943 	kmem_free(bfp,
944 	    sizeof (*bfp) + bfp->bf_maxlinks * sizeof (bridge_link_t *));
945 }
946 
947 static void
948 fwd_unref(bridge_fwd_t *bfp)
949 {
950 	if (atomic_dec_uint_nv(&bfp->bf_refs) == 0) {
951 		ASSERT(!(bfp->bf_flags & BFF_INTREE));
952 		fwd_free(bfp);
953 	}
954 }
955 
956 static void
957 fwd_delete(bridge_fwd_t *bfp)
958 {
959 	bridge_inst_t *bip;
960 	bridge_fwd_t *bfpzero;
961 
962 	if (bfp->bf_flags & BFF_INTREE) {
963 		ASSERT(bfp->bf_nlinks > 0);
964 		bip = bfp->bf_links[0]->bl_inst;
965 		rw_enter(&bip->bi_rwlock, RW_WRITER);
966 		/* Another thread could beat us to this */
967 		if (bfp->bf_flags & BFF_INTREE) {
968 			avl_remove(&bip->bi_fwd, bfp);
969 			bfp->bf_flags &= ~BFF_INTREE;
970 			if (bfp->bf_flags & BFF_VLANLOCAL) {
971 				bfp->bf_flags &= ~BFF_VLANLOCAL;
972 				bfpzero = avl_find(&bip->bi_fwd, bfp, NULL);
973 				if (bfpzero != NULL && bfpzero->bf_vcnt > 0)
974 					bfpzero->bf_vcnt--;
975 			}
976 			rw_exit(&bip->bi_rwlock);
977 			fwd_unref(bfp);		/* no longer in avl tree */
978 		} else {
979 			rw_exit(&bip->bi_rwlock);
980 		}
981 	}
982 }
983 
984 static boolean_t
985 fwd_insert(bridge_inst_t *bip, bridge_fwd_t *bfp)
986 {
987 	avl_index_t idx;
988 	boolean_t retv;
989 
990 	rw_enter(&bip->bi_rwlock, RW_WRITER);
991 	if (!(bip->bi_flags & BIF_SHUTDOWN) &&
992 	    avl_numnodes(&bip->bi_fwd) < bip->bi_tablemax &&
993 	    avl_find(&bip->bi_fwd, bfp, &idx) == NULL) {
994 		avl_insert(&bip->bi_fwd, bfp, idx);
995 		bfp->bf_flags |= BFF_INTREE;
996 		atomic_inc_uint(&bfp->bf_refs);	/* avl entry */
997 		retv = B_TRUE;
998 	} else {
999 		retv = B_FALSE;
1000 	}
1001 	rw_exit(&bip->bi_rwlock);
1002 	return (retv);
1003 }
1004 
1005 static void
1006 fwd_update_local(bridge_link_t *blp, const uint8_t *oldaddr,
1007     const uint8_t *newaddr)
1008 {
1009 	bridge_inst_t *bip = blp->bl_inst;
1010 	bridge_fwd_t *bfp, *bfnew;
1011 	bridge_fwd_t match;
1012 	avl_index_t idx;
1013 	boolean_t drop_ref = B_FALSE;
1014 
1015 	if (bcmp(oldaddr, newaddr, ETHERADDRL) == 0)
1016 		return;
1017 
1018 	if (bcmp(oldaddr, zero_addr, ETHERADDRL) == 0)
1019 		goto no_old_addr;
1020 
1021 	/*
1022 	 * Find the previous entry, and remove our link from it.
1023 	 */
1024 	bcopy(oldaddr, match.bf_dest, ETHERADDRL);
1025 	rw_enter(&bip->bi_rwlock, RW_WRITER);
1026 	if ((bfp = avl_find(&bip->bi_fwd, &match, NULL)) != NULL) {
1027 		int i;
1028 
1029 		/*
1030 		 * See if we're in the list, and remove if so.
1031 		 */
1032 		for (i = 0; i < bfp->bf_nlinks; i++) {
1033 			if (bfp->bf_links[i] == blp) {
1034 				/*
1035 				 * We assume writes are atomic, so no special
1036 				 * MT handling is needed.  The list length is
1037 				 * decremented first, and then we remove
1038 				 * entries.
1039 				 */
1040 				bfp->bf_nlinks--;
1041 				for (; i < bfp->bf_nlinks; i++)
1042 					bfp->bf_links[i] = bfp->bf_links[i + 1];
1043 				drop_ref = B_TRUE;
1044 				break;
1045 			}
1046 		}
1047 		/* If no more links, then remove and free up */
1048 		if (bfp->bf_nlinks == 0) {
1049 			avl_remove(&bip->bi_fwd, bfp);
1050 			bfp->bf_flags &= ~BFF_INTREE;
1051 		} else {
1052 			bfp = NULL;
1053 		}
1054 	}
1055 	rw_exit(&bip->bi_rwlock);
1056 	if (bfp != NULL)
1057 		fwd_unref(bfp);		/* no longer in avl tree */
1058 
1059 	/*
1060 	 * Now get the new link address and add this link to the list.  The
1061 	 * list should be of length 1 unless the user has configured multiple
1062 	 * NICs with the same address.  (That's an incorrect configuration, but
1063 	 * we support it anyway.)
1064 	 */
1065 no_old_addr:
1066 	bfp = NULL;
1067 	if ((bip->bi_flags & BIF_SHUTDOWN) ||
1068 	    bcmp(newaddr, zero_addr, ETHERADDRL) == 0)
1069 		goto no_new_addr;
1070 
1071 	bcopy(newaddr, match.bf_dest, ETHERADDRL);
1072 	rw_enter(&bip->bi_rwlock, RW_WRITER);
1073 	if ((bfp = avl_find(&bip->bi_fwd, &match, &idx)) == NULL) {
1074 		bfnew = fwd_alloc(newaddr, 1, RBRIDGE_NICKNAME_NONE);
1075 		if (bfnew != NULL)
1076 			KIINCR(bki_count);
1077 	} else if (bfp->bf_nlinks < bfp->bf_maxlinks) {
1078 		/* special case: link fits in existing entry */
1079 		bfnew = bfp;
1080 	} else {
1081 		bfnew = fwd_alloc(newaddr, bfp->bf_nlinks + 1,
1082 		    RBRIDGE_NICKNAME_NONE);
1083 		if (bfnew != NULL) {
1084 			KIINCR(bki_count);
1085 			avl_remove(&bip->bi_fwd, bfp);
1086 			bfp->bf_flags &= ~BFF_INTREE;
1087 			bfnew->bf_nlinks = bfp->bf_nlinks;
1088 			bcopy(bfp->bf_links, bfnew->bf_links,
1089 			    bfp->bf_nlinks * sizeof (bfp));
1090 			/* reset the idx value due to removal above */
1091 			(void) avl_find(&bip->bi_fwd, &match, &idx);
1092 		}
1093 	}
1094 
1095 	if (bfnew != NULL) {
1096 		bfnew->bf_links[bfnew->bf_nlinks++] = blp;
1097 		if (drop_ref)
1098 			drop_ref = B_FALSE;
1099 		else
1100 			atomic_inc_uint(&blp->bl_refs);	/* bf_links entry */
1101 
1102 		if (bfnew != bfp) {
1103 			/* local addresses are not subject to table limits */
1104 			avl_insert(&bip->bi_fwd, bfnew, idx);
1105 			bfnew->bf_flags |= (BFF_INTREE | BFF_LOCALADDR);
1106 			atomic_inc_uint(&bfnew->bf_refs);	/* avl entry */
1107 		}
1108 	}
1109 	rw_exit(&bip->bi_rwlock);
1110 
1111 no_new_addr:
1112 	/*
1113 	 * If we found an existing entry and we replaced it with a new one,
1114 	 * then drop the table reference from the old one.  We removed it from
1115 	 * the AVL tree above.
1116 	 */
1117 	if (bfnew != NULL && bfp != NULL && bfnew != bfp)
1118 		fwd_unref(bfp);
1119 
1120 	/* Account for removed entry. */
1121 	if (drop_ref)
1122 		link_unref(blp);
1123 }
1124 
1125 static void
1126 bridge_new_unicst(bridge_link_t *blp)
1127 {
1128 	uint8_t new_mac[ETHERADDRL];
1129 
1130 	mac_unicast_primary_get(blp->bl_mh, new_mac);
1131 	fwd_update_local(blp, blp->bl_local_mac, new_mac);
1132 	bcopy(new_mac, blp->bl_local_mac, ETHERADDRL);
1133 }
1134 
1135 /*
1136  * We must shut down a link prior to freeing it, and doing that requires
1137  * blocking to wait for running MAC threads while holding a reference.  This is
1138  * run from a taskq to accomplish proper link shutdown followed by reference
1139  * drop.
1140  */
1141 static void
1142 link_shutdown(void *arg)
1143 {
1144 	bridge_link_t *blp = arg;
1145 	mac_handle_t mh = blp->bl_mh;
1146 	bridge_inst_t *bip;
1147 	bridge_fwd_t *bfp, *bfnext;
1148 	avl_tree_t fwd_scavenge;
1149 	int i;
1150 
1151 	/*
1152 	 * This link is being destroyed.  Notify TRILL now that it's no longer
1153 	 * possible to send packets.  Data packets may still arrive until TRILL
1154 	 * calls bridge_trill_lnunref.
1155 	 */
1156 	if (blp->bl_trilldata != NULL)
1157 		trill_lndstr_fn(blp->bl_trilldata, blp);
1158 
1159 	if (blp->bl_flags & BLF_PROM_ADDED)
1160 		(void) mac_promisc_remove(blp->bl_mphp);
1161 
1162 	if (blp->bl_flags & BLF_SET_BRIDGE)
1163 		mac_bridge_clear(mh, (mac_handle_t)blp);
1164 
1165 	if (blp->bl_flags & BLF_MARGIN_ADDED) {
1166 		(void) mac_notify_remove(blp->bl_mnh, B_TRUE);
1167 		(void) mac_margin_remove(mh, blp->bl_margin);
1168 	}
1169 
1170 	/* Tell the clients the real link state when we leave */
1171 	mac_link_redo(blp->bl_mh,
1172 	    mac_stat_get(blp->bl_mh, MAC_STAT_LOWLINK_STATE));
1173 
1174 	/* Destroy all of the forwarding entries related to this link */
1175 	avl_create(&fwd_scavenge, fwd_compare, sizeof (bridge_fwd_t),
1176 	    offsetof(bridge_fwd_t, bf_node));
1177 	bip = blp->bl_inst;
1178 	rw_enter(&bip->bi_rwlock, RW_WRITER);
1179 	bfnext = avl_first(&bip->bi_fwd);
1180 	while ((bfp = bfnext) != NULL) {
1181 		bfnext = AVL_NEXT(&bip->bi_fwd, bfp);
1182 		for (i = 0; i < bfp->bf_nlinks; i++) {
1183 			if (bfp->bf_links[i] == blp)
1184 				break;
1185 		}
1186 		if (i >= bfp->bf_nlinks)
1187 			continue;
1188 		if (bfp->bf_nlinks > 1) {
1189 			/* note that this can't be the last reference */
1190 			link_unref(blp);
1191 			bfp->bf_nlinks--;
1192 			for (; i < bfp->bf_nlinks; i++)
1193 				bfp->bf_links[i] = bfp->bf_links[i + 1];
1194 		} else {
1195 			ASSERT(bfp->bf_flags & BFF_INTREE);
1196 			avl_remove(&bip->bi_fwd, bfp);
1197 			bfp->bf_flags &= ~BFF_INTREE;
1198 			avl_add(&fwd_scavenge, bfp);
1199 		}
1200 	}
1201 	rw_exit(&bip->bi_rwlock);
1202 	bfnext = avl_first(&fwd_scavenge);
1203 	while ((bfp = bfnext) != NULL) {
1204 		bfnext = AVL_NEXT(&fwd_scavenge, bfp);
1205 		avl_remove(&fwd_scavenge, bfp);
1206 		fwd_unref(bfp);
1207 	}
1208 	avl_destroy(&fwd_scavenge);
1209 
1210 	if (blp->bl_flags & BLF_CLIENT_OPEN)
1211 		mac_client_close(blp->bl_mch, 0);
1212 
1213 	mac_close(mh);
1214 
1215 	/*
1216 	 * We are now completely removed from the active list, so drop the
1217 	 * reference (see bridge_add_link).
1218 	 */
1219 	link_unref(blp);
1220 }
1221 
1222 static void
1223 shutdown_inst(bridge_inst_t *bip)
1224 {
1225 	bridge_link_t *blp, *blnext;
1226 	bridge_fwd_t *bfp;
1227 
1228 	mutex_enter(&inst_lock);
1229 	if (bip->bi_flags & BIF_SHUTDOWN) {
1230 		mutex_exit(&inst_lock);
1231 		return;
1232 	}
1233 
1234 	/*
1235 	 * Once on the inst_list, the bridge instance must not leave that list
1236 	 * without having the shutdown flag set first.  When the shutdown flag
1237 	 * is set, we own the list reference, so we must drop it before
1238 	 * returning.
1239 	 */
1240 	bip->bi_flags |= BIF_SHUTDOWN;
1241 	mutex_exit(&inst_lock);
1242 
1243 	bip->bi_control = NULL;
1244 
1245 	rw_enter(&bip->bi_rwlock, RW_READER);
1246 	blnext = list_head(&bip->bi_links);
1247 	while ((blp = blnext) != NULL) {
1248 		blnext = list_next(&bip->bi_links, blp);
1249 		if (!(blp->bl_flags & BLF_DELETED)) {
1250 			blp->bl_flags |= BLF_DELETED;
1251 			(void) ddi_taskq_dispatch(bridge_taskq, link_shutdown,
1252 			    blp, DDI_SLEEP);
1253 		}
1254 	}
1255 	while ((bfp = avl_first(&bip->bi_fwd)) != NULL) {
1256 		atomic_inc_uint(&bfp->bf_refs);
1257 		rw_exit(&bip->bi_rwlock);
1258 		fwd_delete(bfp);
1259 		fwd_unref(bfp);
1260 		rw_enter(&bip->bi_rwlock, RW_READER);
1261 	}
1262 	rw_exit(&bip->bi_rwlock);
1263 
1264 	/*
1265 	 * This bridge is being destroyed.  Notify TRILL once all of the
1266 	 * links are all gone.
1267 	 */
1268 	mutex_enter(&inst_lock);
1269 	while (bip->bi_trilldata != NULL && !list_is_empty(&bip->bi_links))
1270 		cv_wait(&bip->bi_linkwait, &inst_lock);
1271 	mutex_exit(&inst_lock);
1272 	if (bip->bi_trilldata != NULL)
1273 		trill_brdstr_fn(bip->bi_trilldata, bip);
1274 
1275 	bridge_unref(bip);
1276 }
1277 
1278 /*
1279  * This is called once by the TRILL module when it starts up.  It just sets the
1280  * global TRILL callback function pointers -- data transmit/receive and bridge
1281  * and link destroy notification.  There's only one TRILL module, so only one
1282  * registration is needed.
1283  *
1284  * TRILL should call this function with NULL pointers before unloading.  It
1285  * must not do so before dropping all references to bridges and links.  We
1286  * assert that this is true on debug builds.
1287  */
1288 void
1289 bridge_trill_register_cb(trill_recv_pkt_t recv_fn, trill_encap_pkt_t encap_fn,
1290     trill_br_dstr_t brdstr_fn, trill_ln_dstr_t lndstr_fn)
1291 {
1292 #ifdef DEBUG
1293 	if (recv_fn == NULL && trill_recv_fn != NULL) {
1294 		bridge_inst_t *bip;
1295 		bridge_link_t *blp;
1296 
1297 		mutex_enter(&inst_lock);
1298 		for (bip = list_head(&inst_list); bip != NULL;
1299 		    bip = list_next(&inst_list, bip)) {
1300 			ASSERT(bip->bi_trilldata == NULL);
1301 			rw_enter(&bip->bi_rwlock, RW_READER);
1302 			for (blp = list_head(&bip->bi_links); blp != NULL;
1303 			    blp = list_next(&bip->bi_links, blp)) {
1304 				ASSERT(blp->bl_trilldata == NULL);
1305 			}
1306 			rw_exit(&bip->bi_rwlock);
1307 		}
1308 		mutex_exit(&inst_lock);
1309 	}
1310 #endif
1311 	trill_recv_fn = recv_fn;
1312 	trill_encap_fn = encap_fn;
1313 	trill_brdstr_fn = brdstr_fn;
1314 	trill_lndstr_fn = lndstr_fn;
1315 }
1316 
1317 /*
1318  * This registers the TRILL instance pointer with a bridge.  Before this
1319  * pointer is set, the forwarding, TRILL receive, and bridge destructor
1320  * functions won't be called.
1321  *
1322  * TRILL holds a reference on a bridge with this call.  It must free the
1323  * reference by calling the unregister function below.
1324  */
1325 bridge_inst_t *
1326 bridge_trill_brref(const char *bname, void *ptr)
1327 {
1328 	char bridge[MAXLINKNAMELEN];
1329 	bridge_inst_t *bip;
1330 
1331 	(void) snprintf(bridge, MAXLINKNAMELEN, "%s0", bname);
1332 	bip = bridge_find_name(bridge);
1333 	if (bip != NULL) {
1334 		ASSERT(bip->bi_trilldata == NULL && ptr != NULL);
1335 		bip->bi_trilldata = ptr;
1336 	}
1337 	return (bip);
1338 }
1339 
1340 void
1341 bridge_trill_brunref(bridge_inst_t *bip)
1342 {
1343 	ASSERT(bip->bi_trilldata != NULL);
1344 	bip->bi_trilldata = NULL;
1345 	bridge_unref(bip);
1346 }
1347 
1348 /*
1349  * TRILL calls this function when referencing a particular link on a bridge.
1350  *
1351  * It holds a reference on the link, so TRILL must clear out the reference when
1352  * it's done with the link (on unbinding).
1353  */
1354 bridge_link_t *
1355 bridge_trill_lnref(bridge_inst_t *bip, datalink_id_t linkid, void *ptr)
1356 {
1357 	bridge_link_t *blp;
1358 
1359 	ASSERT(ptr != NULL);
1360 	rw_enter(&bip->bi_rwlock, RW_READER);
1361 	for (blp = list_head(&bip->bi_links); blp != NULL;
1362 	    blp = list_next(&bip->bi_links, blp)) {
1363 		if (!(blp->bl_flags & BLF_DELETED) &&
1364 		    blp->bl_linkid == linkid && blp->bl_trilldata == NULL) {
1365 			blp->bl_trilldata = ptr;
1366 			blp->bl_flags &= ~BLF_TRILLACTIVE;
1367 			(void) memset(blp->bl_afs, 0, sizeof (blp->bl_afs));
1368 			atomic_inc_uint(&blp->bl_refs);
1369 			break;
1370 		}
1371 	}
1372 	rw_exit(&bip->bi_rwlock);
1373 	return (blp);
1374 }
1375 
1376 void
1377 bridge_trill_lnunref(bridge_link_t *blp)
1378 {
1379 	mutex_enter(&blp->bl_trilllock);
1380 	ASSERT(blp->bl_trilldata != NULL);
1381 	blp->bl_trilldata = NULL;
1382 	blp->bl_flags &= ~BLF_TRILLACTIVE;
1383 	while (blp->bl_trillthreads > 0)
1384 		cv_wait(&blp->bl_trillwait, &blp->bl_trilllock);
1385 	mutex_exit(&blp->bl_trilllock);
1386 	(void) memset(blp->bl_afs, 0xff, sizeof (blp->bl_afs));
1387 	link_unref(blp);
1388 }
1389 
1390 /*
1391  * This periodic timer performs three functions:
1392  *  1. It scans the list of learned forwarding entries, and removes ones that
1393  *     haven't been heard from in a while.  The time limit is backed down if
1394  *     we're above the configured table limit.
1395  *  2. It walks the links and decays away the bl_learns counter.
1396  *  3. It scans the observability node entries looking for ones that can be
1397  *     freed up.
1398  */
1399 /* ARGSUSED */
1400 static void
1401 bridge_timer(void *arg)
1402 {
1403 	bridge_inst_t *bip;
1404 	bridge_fwd_t *bfp, *bfnext;
1405 	bridge_mac_t *bmp, *bmnext;
1406 	bridge_link_t *blp;
1407 	int err;
1408 	datalink_id_t tmpid;
1409 	avl_tree_t fwd_scavenge;
1410 	clock_t age_limit;
1411 	uint32_t ldecay;
1412 
1413 	avl_create(&fwd_scavenge, fwd_compare, sizeof (bridge_fwd_t),
1414 	    offsetof(bridge_fwd_t, bf_node));
1415 	mutex_enter(&inst_lock);
1416 	for (bip = list_head(&inst_list); bip != NULL;
1417 	    bip = list_next(&inst_list, bip)) {
1418 		if (bip->bi_flags & BIF_SHUTDOWN)
1419 			continue;
1420 		rw_enter(&bip->bi_rwlock, RW_WRITER);
1421 		/* compute scaled maximum age based on table limit */
1422 		if (avl_numnodes(&bip->bi_fwd) > bip->bi_tablemax)
1423 			bip->bi_tshift++;
1424 		else
1425 			bip->bi_tshift = 0;
1426 		if ((age_limit = bridge_fwd_age >> bip->bi_tshift) == 0) {
1427 			if (bip->bi_tshift != 0)
1428 				bip->bi_tshift--;
1429 			age_limit = 1;
1430 		}
1431 		bfnext = avl_first(&bip->bi_fwd);
1432 		while ((bfp = bfnext) != NULL) {
1433 			bfnext = AVL_NEXT(&bip->bi_fwd, bfp);
1434 			if (!(bfp->bf_flags & BFF_LOCALADDR) &&
1435 			    (ddi_get_lbolt() - bfp->bf_lastheard) > age_limit) {
1436 				ASSERT(bfp->bf_flags & BFF_INTREE);
1437 				avl_remove(&bip->bi_fwd, bfp);
1438 				bfp->bf_flags &= ~BFF_INTREE;
1439 				avl_add(&fwd_scavenge, bfp);
1440 			}
1441 		}
1442 		for (blp = list_head(&bip->bi_links); blp != NULL;
1443 		    blp = list_next(&bip->bi_links, blp)) {
1444 			ldecay = mac_get_ldecay(blp->bl_mh);
1445 			if (ldecay >= blp->bl_learns)
1446 				blp->bl_learns = 0;
1447 			else
1448 				atomic_add_int(&blp->bl_learns, -(int)ldecay);
1449 		}
1450 		rw_exit(&bip->bi_rwlock);
1451 		bfnext = avl_first(&fwd_scavenge);
1452 		while ((bfp = bfnext) != NULL) {
1453 			bfnext = AVL_NEXT(&fwd_scavenge, bfp);
1454 			avl_remove(&fwd_scavenge, bfp);
1455 			KIINCR(bki_expire);
1456 			fwd_unref(bfp);	/* drop tree reference */
1457 		}
1458 	}
1459 	mutex_exit(&inst_lock);
1460 	avl_destroy(&fwd_scavenge);
1461 
1462 	/*
1463 	 * Scan the bridge_mac_t entries and try to free up the ones that are
1464 	 * no longer active.  This must be done by polling, as neither DLS nor
1465 	 * MAC provides a driver any sort of positive control over clients.
1466 	 */
1467 	rw_enter(&bmac_rwlock, RW_WRITER);
1468 	bmnext = list_head(&bmac_list);
1469 	while ((bmp = bmnext) != NULL) {
1470 		bmnext = list_next(&bmac_list, bmp);
1471 
1472 		/* ignore active bridges */
1473 		if (bmp->bm_inst != NULL)
1474 			continue;
1475 
1476 		if (bmp->bm_flags & BMF_DLS) {
1477 			err = dls_devnet_destroy(bmp->bm_mh, &tmpid, B_FALSE);
1478 			ASSERT(err == 0 || err == EBUSY);
1479 			if (err == 0)
1480 				bmp->bm_flags &= ~BMF_DLS;
1481 		}
1482 
1483 		if (!(bmp->bm_flags & BMF_DLS)) {
1484 			err = mac_unregister(bmp->bm_mh);
1485 			ASSERT(err == 0 || err == EBUSY);
1486 			if (err == 0) {
1487 				list_remove(&bmac_list, bmp);
1488 				kmem_free(bmp, sizeof (*bmp));
1489 			}
1490 		}
1491 	}
1492 	if (list_is_empty(&bmac_list)) {
1493 		bridge_timerid = 0;
1494 	} else {
1495 		bridge_timerid = timeout(bridge_timer, NULL,
1496 		    bridge_scan_interval);
1497 	}
1498 	rw_exit(&bmac_rwlock);
1499 }
1500 
1501 static int
1502 bridge_open(queue_t *rq, dev_t *devp, int oflag, int sflag, cred_t *credp)
1503 {
1504 	bridge_stream_t	*bsp;
1505 
1506 	if (rq->q_ptr != NULL)
1507 		return (0);
1508 
1509 	if (sflag & MODOPEN)
1510 		return (EINVAL);
1511 
1512 	/*
1513 	 * Check the minor node number being opened.  This tells us which
1514 	 * bridge instance the user wants.
1515 	 */
1516 	if (getminor(*devp) != 0) {
1517 		/*
1518 		 * This is a regular DLPI stream for snoop or the like.
1519 		 * Redirect it through DLD.
1520 		 */
1521 		rq->q_qinfo = &bridge_dld_rinit;
1522 		OTHERQ(rq)->q_qinfo = &bridge_dld_winit;
1523 		return (dld_open(rq, devp, oflag, sflag, credp));
1524 	} else {
1525 		/*
1526 		 * Allocate the bridge control stream structure.
1527 		 */
1528 		if ((bsp = stream_alloc()) == NULL)
1529 			return (ENOSR);
1530 		rq->q_ptr = WR(rq)->q_ptr = (caddr_t)bsp;
1531 		bsp->bs_wq = WR(rq);
1532 		*devp = makedevice(getmajor(*devp), bsp->bs_minor);
1533 		qprocson(rq);
1534 		return (0);
1535 	}
1536 }
1537 
1538 /*
1539  * This is used only for bridge control streams.  DLPI goes through dld
1540  * instead.
1541  */
1542 static int
1543 bridge_close(queue_t *rq)
1544 {
1545 	bridge_stream_t	*bsp = rq->q_ptr;
1546 	bridge_inst_t *bip;
1547 
1548 	/*
1549 	 * Wait for any stray taskq (add/delete link) entries related to this
1550 	 * stream to leave the system.
1551 	 */
1552 	mutex_enter(&stream_ref_lock);
1553 	while (bsp->bs_taskq_cnt != 0)
1554 		cv_wait(&stream_ref_cv, &stream_ref_lock);
1555 	mutex_exit(&stream_ref_lock);
1556 
1557 	qprocsoff(rq);
1558 	if ((bip = bsp->bs_inst) != NULL)
1559 		shutdown_inst(bip);
1560 	rq->q_ptr = WR(rq)->q_ptr = NULL;
1561 	stream_free(bsp);
1562 	if (bip != NULL)
1563 		bridge_unref(bip);
1564 
1565 	return (0);
1566 }
1567 
1568 static void
1569 bridge_learn(bridge_link_t *blp, const uint8_t *saddr, uint16_t ingress_nick,
1570     uint16_t vlanid)
1571 {
1572 	bridge_inst_t *bip = blp->bl_inst;
1573 	bridge_fwd_t *bfp, *bfpnew;
1574 	int i;
1575 	boolean_t replaced = B_FALSE;
1576 
1577 	/* Ignore multi-destination address used as source; it's nonsense. */
1578 	if (*saddr & 1)
1579 		return;
1580 
1581 	/*
1582 	 * If the source is known, then check whether it belongs on this link.
1583 	 * If not, and this isn't a fixed local address, then we've detected a
1584 	 * move.  If it's not known, learn it.
1585 	 */
1586 	if ((bfp = fwd_find(bip, saddr, vlanid)) != NULL) {
1587 		/*
1588 		 * If the packet has a fixed local source address, then there's
1589 		 * nothing we can learn.  We must quit.  If this was a received
1590 		 * packet, then the sender has stolen our address, but there's
1591 		 * nothing we can do.  If it's a transmitted packet, then
1592 		 * that's the normal case.
1593 		 */
1594 		if (bfp->bf_flags & BFF_LOCALADDR) {
1595 			fwd_unref(bfp);
1596 			return;
1597 		}
1598 
1599 		/*
1600 		 * Check if the link (and TRILL sender, if any) being used is
1601 		 * among the ones registered for this address.  If so, then
1602 		 * this is information that we already know.
1603 		 */
1604 		if (bfp->bf_trill_nick == ingress_nick) {
1605 			for (i = 0; i < bfp->bf_nlinks; i++) {
1606 				if (bfp->bf_links[i] == blp) {
1607 					bfp->bf_lastheard = ddi_get_lbolt();
1608 					fwd_unref(bfp);
1609 					return;
1610 				}
1611 			}
1612 		}
1613 	}
1614 
1615 	/*
1616 	 * Note that we intentionally "unlearn" things that appear to be under
1617 	 * attack on this link.  The forwarding cache is a negative thing for
1618 	 * security -- it disables reachability as a performance optimization
1619 	 * -- so leaving out entries optimizes for success and defends against
1620 	 * the attack.  Thus, the bare increment without a check in the delete
1621 	 * code above is right.  (And it's ok if we skid over the limit a
1622 	 * little, so there's no syncronization needed on the test.)
1623 	 */
1624 	if (blp->bl_learns >= mac_get_llimit(blp->bl_mh)) {
1625 		if (bfp != NULL) {
1626 			if (bfp->bf_vcnt == 0)
1627 				fwd_delete(bfp);
1628 			fwd_unref(bfp);
1629 		}
1630 		return;
1631 	}
1632 
1633 	atomic_inc_uint(&blp->bl_learns);
1634 
1635 	if ((bfpnew = fwd_alloc(saddr, 1, ingress_nick)) == NULL) {
1636 		if (bfp != NULL)
1637 			fwd_unref(bfp);
1638 		return;
1639 	}
1640 	KIINCR(bki_count);
1641 
1642 	if (bfp != NULL) {
1643 		/*
1644 		 * If this is a new destination for the same VLAN, then delete
1645 		 * so that we can update.  If it's a different VLAN, then we're
1646 		 * not going to delete the original.  Split off instead into an
1647 		 * IVL entry.
1648 		 */
1649 		if (bfp->bf_vlanid == vlanid) {
1650 			/* save the count of IVL duplicates */
1651 			bfpnew->bf_vcnt = bfp->bf_vcnt;
1652 
1653 			/* entry deletes count as learning events */
1654 			atomic_inc_uint(&blp->bl_learns);
1655 
1656 			/* destroy and create anew; node moved */
1657 			fwd_delete(bfp);
1658 			replaced = B_TRUE;
1659 			KIINCR(bki_moved);
1660 		} else {
1661 			bfp->bf_vcnt++;
1662 			bfpnew->bf_flags |= BFF_VLANLOCAL;
1663 		}
1664 		fwd_unref(bfp);
1665 	}
1666 	bfpnew->bf_links[0] = blp;
1667 	bfpnew->bf_nlinks = 1;
1668 	atomic_inc_uint(&blp->bl_refs);	/* bf_links entry */
1669 	if (!fwd_insert(bip, bfpnew))
1670 		fwd_free(bfpnew);
1671 	else if (!replaced)
1672 		KIINCR(bki_source);
1673 }
1674 
1675 /*
1676  * Process the VLAN headers for output on a given link.  There are several
1677  * cases (noting that we don't map VLANs):
1678  *   1. The input packet is good as it is; either
1679  *	a. It has no tag, and output has same PVID
1680  *	b. It has a non-zero priority-only tag for PVID, and b_band is same
1681  *	c. It has a tag with VLAN different from PVID, and b_band is same
1682  *   2. The tag must change: non-zero b_band is different from tag priority
1683  *   3. The packet has a tag and should not (VLAN same as PVID, b_band zero)
1684  *   4. The packet has no tag and needs one:
1685  *      a. VLAN ID same as PVID, but b_band is non-zero
1686  *      b. VLAN ID different from PVID
1687  * We exclude case 1 first, then modify the packet.  Note that output packets
1688  * get a priority set by the mblk, not by the header, because QoS in bridging
1689  * requires priority recalculation at each node.
1690  *
1691  * The passed-in tci is the "impossible" value 0xFFFF when no tag is present.
1692  */
1693 static mblk_t *
1694 reform_vlan_header(mblk_t *mp, uint16_t vlanid, uint16_t tci, uint16_t pvid)
1695 {
1696 	boolean_t source_has_tag = (tci != 0xFFFF);
1697 	mblk_t *mpcopy;
1698 	size_t mlen, minlen;
1699 	struct ether_vlan_header *evh;
1700 	int pri;
1701 
1702 	/* This helps centralize error handling in the caller. */
1703 	if (mp == NULL)
1704 		return (mp);
1705 
1706 	/* No forwarded packet can have hardware checksum enabled */
1707 	DB_CKSUMFLAGS(mp) = 0;
1708 
1709 	/* Get the no-modification cases out of the way first */
1710 	if (!source_has_tag && vlanid == pvid)		/* 1a */
1711 		return (mp);
1712 
1713 	pri = VLAN_PRI(tci);
1714 	if (source_has_tag && mp->b_band == pri) {
1715 		if (vlanid != pvid)			/* 1c */
1716 			return (mp);
1717 		if (pri != 0 && VLAN_ID(tci) == 0)	/* 1b */
1718 			return (mp);
1719 	}
1720 
1721 	/*
1722 	 * We now know that we must modify the packet.  Prepare for that.  Note
1723 	 * that if a tag is present, the caller has already done a pullup for
1724 	 * the VLAN header, so we're good to go.
1725 	 */
1726 	if (MBLKL(mp) < sizeof (struct ether_header)) {
1727 		mpcopy = msgpullup(mp, sizeof (struct ether_header));
1728 		if (mpcopy == NULL) {
1729 			freemsg(mp);
1730 			return (NULL);
1731 		}
1732 		mp = mpcopy;
1733 	}
1734 	if (DB_REF(mp) > 1 || !IS_P2ALIGNED(mp->b_rptr, sizeof (uint16_t)) ||
1735 	    (!source_has_tag && MBLKTAIL(mp) < VLAN_INCR)) {
1736 		minlen = mlen = MBLKL(mp);
1737 		if (!source_has_tag)
1738 			minlen += VLAN_INCR;
1739 		ASSERT(minlen >= sizeof (struct ether_vlan_header));
1740 		/*
1741 		 * We're willing to copy some data to avoid fragmentation, but
1742 		 * not a lot.
1743 		 */
1744 		if (minlen > 256)
1745 			minlen = sizeof (struct ether_vlan_header);
1746 		mpcopy = allocb(minlen, BPRI_MED);
1747 		if (mpcopy == NULL) {
1748 			freemsg(mp);
1749 			return (NULL);
1750 		}
1751 		if (mlen <= minlen) {
1752 			/* We toss the first mblk when we can. */
1753 			bcopy(mp->b_rptr, mpcopy->b_rptr, mlen);
1754 			mpcopy->b_wptr += mlen;
1755 			mpcopy->b_cont = mp->b_cont;
1756 			freeb(mp);
1757 		} else {
1758 			/* If not, then just copy what we need */
1759 			if (!source_has_tag)
1760 				minlen = sizeof (struct ether_header);
1761 			bcopy(mp->b_rptr, mpcopy->b_rptr, minlen);
1762 			mpcopy->b_wptr += minlen;
1763 			mpcopy->b_cont = mp;
1764 			mp->b_rptr += minlen;
1765 		}
1766 		mp = mpcopy;
1767 	}
1768 
1769 	/* LINTED: pointer alignment */
1770 	evh = (struct ether_vlan_header *)mp->b_rptr;
1771 	if (source_has_tag) {
1772 		if (mp->b_band == 0 && vlanid == pvid) {	/* 3 */
1773 			evh->ether_tpid = evh->ether_type;
1774 			mlen = MBLKL(mp);
1775 			if (mlen > sizeof (struct ether_vlan_header))
1776 				ovbcopy(mp->b_rptr +
1777 				    sizeof (struct ether_vlan_header),
1778 				    mp->b_rptr + sizeof (struct ether_header),
1779 				    mlen - sizeof (struct ether_vlan_header));
1780 			mp->b_wptr -= VLAN_INCR;
1781 		} else {					/* 2 */
1782 			if (vlanid == pvid)
1783 				vlanid = VLAN_ID_NONE;
1784 			tci = VLAN_TCI(mp->b_band, ETHER_CFI, vlanid);
1785 			evh->ether_tci = htons(tci);
1786 		}
1787 	} else {
1788 		/* case 4: no header present, but one is needed */
1789 		mlen = MBLKL(mp);
1790 		if (mlen > sizeof (struct ether_header))
1791 			ovbcopy(mp->b_rptr + sizeof (struct ether_header),
1792 			    mp->b_rptr + sizeof (struct ether_vlan_header),
1793 			    mlen - sizeof (struct ether_header));
1794 		mp->b_wptr += VLAN_INCR;
1795 		ASSERT(mp->b_wptr <= DB_LIM(mp));
1796 		if (vlanid == pvid)
1797 			vlanid = VLAN_ID_NONE;
1798 		tci = VLAN_TCI(mp->b_band, ETHER_CFI, vlanid);
1799 		evh->ether_type = evh->ether_tpid;
1800 		evh->ether_tpid = htons(ETHERTYPE_VLAN);
1801 		evh->ether_tci = htons(tci);
1802 	}
1803 	return (mp);
1804 }
1805 
1806 /* Record VLAN information and strip header if requested . */
1807 static void
1808 update_header(mblk_t *mp, mac_header_info_t *hdr_info, boolean_t striphdr)
1809 {
1810 	if (hdr_info->mhi_bindsap == ETHERTYPE_VLAN) {
1811 		struct ether_vlan_header *evhp;
1812 		uint16_t ether_type;
1813 
1814 		/* LINTED: alignment */
1815 		evhp = (struct ether_vlan_header *)mp->b_rptr;
1816 		hdr_info->mhi_istagged = B_TRUE;
1817 		hdr_info->mhi_tci = ntohs(evhp->ether_tci);
1818 		if (striphdr) {
1819 			/*
1820 			 * For VLAN tagged frames update the ether_type
1821 			 * in hdr_info before stripping the header.
1822 			 */
1823 			ether_type = ntohs(evhp->ether_type);
1824 			hdr_info->mhi_origsap = ether_type;
1825 			hdr_info->mhi_bindsap = (ether_type > ETHERMTU) ?
1826 			    ether_type : DLS_SAP_LLC;
1827 			mp->b_rptr = (uchar_t *)(evhp + 1);
1828 		}
1829 	} else {
1830 		hdr_info->mhi_istagged = B_FALSE;
1831 		hdr_info->mhi_tci = VLAN_ID_NONE;
1832 		if (striphdr)
1833 			mp->b_rptr += sizeof (struct ether_header);
1834 	}
1835 }
1836 
1837 /*
1838  * Return B_TRUE if we're allowed to send on this link with the given VLAN ID.
1839  */
1840 static boolean_t
1841 bridge_can_send(bridge_link_t *blp, uint16_t vlanid)
1842 {
1843 	ASSERT(vlanid != VLAN_ID_NONE);
1844 	if (blp->bl_flags & BLF_DELETED)
1845 		return (B_FALSE);
1846 	if (blp->bl_trilldata == NULL && blp->bl_state != BLS_FORWARDING)
1847 		return (B_FALSE);
1848 	return (BRIDGE_VLAN_ISSET(blp, vlanid) && BRIDGE_AF_ISSET(blp, vlanid));
1849 }
1850 
1851 /*
1852  * This function scans the bridge forwarding tables in order to forward a given
1853  * packet.  If the packet either doesn't need forwarding (the current link is
1854  * correct) or the current link needs a copy as well, then the packet is
1855  * returned to the caller.
1856  *
1857  * If a packet has been decapsulated from TRILL, then it must *NOT* reenter a
1858  * TRILL tunnel.  If the destination points there, then drop instead.
1859  */
1860 static mblk_t *
1861 bridge_forward(bridge_link_t *blp, mac_header_info_t *hdr_info, mblk_t *mp,
1862     uint16_t vlanid, uint16_t tci, boolean_t from_trill, boolean_t is_xmit)
1863 {
1864 	mblk_t *mpsend, *mpcopy;
1865 	bridge_inst_t *bip = blp->bl_inst;
1866 	bridge_link_t *blpsend, *blpnext;
1867 	bridge_fwd_t *bfp;
1868 	uint_t i;
1869 	boolean_t selfseen = B_FALSE;
1870 	void *tdp;
1871 	const uint8_t *daddr = hdr_info->mhi_daddr;
1872 
1873 	/*
1874 	 * Check for the IEEE "reserved" multicast addresses.  Messages sent to
1875 	 * these addresses are used for link-local control (STP and pause), and
1876 	 * are never forwarded or redirected.
1877 	 */
1878 	if (daddr[0] == 1 && daddr[1] == 0x80 && daddr[2] == 0xc2 &&
1879 	    daddr[3] == 0 && daddr[4] == 0 && (daddr[5] & 0xf0) == 0) {
1880 		if (from_trill) {
1881 			freemsg(mp);
1882 			mp = NULL;
1883 		}
1884 		return (mp);
1885 	}
1886 
1887 	if ((bfp = fwd_find(bip, daddr, vlanid)) != NULL) {
1888 
1889 		/*
1890 		 * If trill indicates a destination for this node, then it's
1891 		 * clearly not intended for local delivery.  We must tell TRILL
1892 		 * to encapsulate, as long as we didn't just decapsulate it.
1893 		 */
1894 		if (bfp->bf_trill_nick != RBRIDGE_NICKNAME_NONE) {
1895 			/*
1896 			 * Error case: can't reencapsulate if the protocols are
1897 			 * working correctly.
1898 			 */
1899 			if (from_trill) {
1900 				freemsg(mp);
1901 				return (NULL);
1902 			}
1903 			mutex_enter(&blp->bl_trilllock);
1904 			if ((tdp = blp->bl_trilldata) != NULL) {
1905 				blp->bl_trillthreads++;
1906 				mutex_exit(&blp->bl_trilllock);
1907 				update_header(mp, hdr_info, B_FALSE);
1908 				if (is_xmit)
1909 					mp = mac_fix_cksum(mp);
1910 				/* all trill data frames have Inner.VLAN */
1911 				mp = reform_vlan_header(mp, vlanid, tci, 0);
1912 				if (mp == NULL) {
1913 					KIINCR(bki_drops);
1914 					fwd_unref(bfp);
1915 					return (NULL);
1916 				}
1917 				trill_encap_fn(tdp, blp, hdr_info, mp,
1918 				    bfp->bf_trill_nick);
1919 				mutex_enter(&blp->bl_trilllock);
1920 				if (--blp->bl_trillthreads == 0 &&
1921 				    blp->bl_trilldata == NULL)
1922 					cv_broadcast(&blp->bl_trillwait);
1923 			}
1924 			mutex_exit(&blp->bl_trilllock);
1925 
1926 			/* if TRILL has been disabled, then kill this stray */
1927 			if (tdp == NULL) {
1928 				freemsg(mp);
1929 				fwd_delete(bfp);
1930 			}
1931 			fwd_unref(bfp);
1932 			return (NULL);
1933 		}
1934 
1935 		/* find first link we can send on */
1936 		for (i = 0; i < bfp->bf_nlinks; i++) {
1937 			blpsend = bfp->bf_links[i];
1938 			if (blpsend == blp)
1939 				selfseen = B_TRUE;
1940 			else if (bridge_can_send(blpsend, vlanid))
1941 				break;
1942 		}
1943 
1944 		while (i < bfp->bf_nlinks) {
1945 			blpsend = bfp->bf_links[i];
1946 			for (i++; i < bfp->bf_nlinks; i++) {
1947 				blpnext = bfp->bf_links[i];
1948 				if (blpnext == blp)
1949 					selfseen = B_TRUE;
1950 				else if (bridge_can_send(blpnext, vlanid))
1951 					break;
1952 			}
1953 			if (i == bfp->bf_nlinks && !selfseen) {
1954 				mpsend = mp;
1955 				mp = NULL;
1956 			} else {
1957 				mpsend = copymsg(mp);
1958 			}
1959 
1960 			if (!from_trill && is_xmit)
1961 				mpsend = mac_fix_cksum(mpsend);
1962 
1963 			mpsend = reform_vlan_header(mpsend, vlanid, tci,
1964 			    blpsend->bl_pvid);
1965 			if (mpsend == NULL) {
1966 				KIINCR(bki_drops);
1967 				continue;
1968 			}
1969 
1970 			KIINCR(bki_forwards);
1971 			/*
1972 			 * No need to bump up the link reference count, as
1973 			 * the forwarding entry itself holds a reference to
1974 			 * the link.
1975 			 */
1976 			if (bfp->bf_flags & BFF_LOCALADDR) {
1977 				mac_rx_common(blpsend->bl_mh, NULL, mpsend);
1978 			} else {
1979 				KLPINCR(blpsend, bkl_xmit);
1980 				MAC_RING_TX(blpsend->bl_mh, NULL, mpsend,
1981 				    mpsend);
1982 				freemsg(mpsend);
1983 			}
1984 		}
1985 		/*
1986 		 * Handle a special case: if we're transmitting to the original
1987 		 * link, then check whether the localaddr flag is set.  If it
1988 		 * is, then receive instead.  This doesn't happen with ordinary
1989 		 * bridging, but does happen often with TRILL decapsulation.
1990 		 */
1991 		if (mp != NULL && is_xmit && (bfp->bf_flags & BFF_LOCALADDR)) {
1992 			mac_rx_common(blp->bl_mh, NULL, mp);
1993 			mp = NULL;
1994 		}
1995 		fwd_unref(bfp);
1996 	} else {
1997 		/*
1998 		 * TRILL has two cases to handle.  If the packet is off the
1999 		 * wire (not from TRILL), then we need to send up into the
2000 		 * TRILL module to have the distribution tree computed.  If the
2001 		 * packet is from TRILL (decapsulated), then we're part of the
2002 		 * distribution tree, and we need to copy the packet on member
2003 		 * interfaces.
2004 		 *
2005 		 * Thus, the from TRILL case is identical to the STP case.
2006 		 */
2007 		if (!from_trill && blp->bl_trilldata != NULL) {
2008 			mutex_enter(&blp->bl_trilllock);
2009 			if ((tdp = blp->bl_trilldata) != NULL) {
2010 				blp->bl_trillthreads++;
2011 				mutex_exit(&blp->bl_trilllock);
2012 				if ((mpsend = copymsg(mp)) != NULL) {
2013 					update_header(mpsend,
2014 					    hdr_info, B_FALSE);
2015 					/*
2016 					 * all trill data frames have
2017 					 * Inner.VLAN
2018 					 */
2019 					mpsend = reform_vlan_header(mpsend,
2020 					    vlanid, tci, 0);
2021 					if (mpsend == NULL) {
2022 						KIINCR(bki_drops);
2023 					} else {
2024 						trill_encap_fn(tdp, blp,
2025 						    hdr_info, mpsend,
2026 						    RBRIDGE_NICKNAME_NONE);
2027 					}
2028 				}
2029 				mutex_enter(&blp->bl_trilllock);
2030 				if (--blp->bl_trillthreads == 0 &&
2031 				    blp->bl_trilldata == NULL)
2032 					cv_broadcast(&blp->bl_trillwait);
2033 			}
2034 			mutex_exit(&blp->bl_trilllock);
2035 		}
2036 
2037 		/*
2038 		 * This is an unknown destination, so flood.
2039 		 */
2040 		rw_enter(&bip->bi_rwlock, RW_READER);
2041 		for (blpnext = list_head(&bip->bi_links); blpnext != NULL;
2042 		    blpnext = list_next(&bip->bi_links, blpnext)) {
2043 			if (blpnext == blp)
2044 				selfseen = B_TRUE;
2045 			else if (bridge_can_send(blpnext, vlanid))
2046 				break;
2047 		}
2048 		if (blpnext != NULL)
2049 			atomic_inc_uint(&blpnext->bl_refs);
2050 		rw_exit(&bip->bi_rwlock);
2051 		while ((blpsend = blpnext) != NULL) {
2052 			rw_enter(&bip->bi_rwlock, RW_READER);
2053 			for (blpnext = list_next(&bip->bi_links, blpsend);
2054 			    blpnext != NULL;
2055 			    blpnext = list_next(&bip->bi_links, blpnext)) {
2056 				if (blpnext == blp)
2057 					selfseen = B_TRUE;
2058 				else if (bridge_can_send(blpnext, vlanid))
2059 					break;
2060 			}
2061 			if (blpnext != NULL)
2062 				atomic_inc_uint(&blpnext->bl_refs);
2063 			rw_exit(&bip->bi_rwlock);
2064 			if (blpnext == NULL && !selfseen) {
2065 				mpsend = mp;
2066 				mp = NULL;
2067 			} else {
2068 				mpsend = copymsg(mp);
2069 			}
2070 
2071 			if (!from_trill && is_xmit)
2072 				mpsend = mac_fix_cksum(mpsend);
2073 
2074 			mpsend = reform_vlan_header(mpsend, vlanid, tci,
2075 			    blpsend->bl_pvid);
2076 			if (mpsend == NULL) {
2077 				KIINCR(bki_drops);
2078 				continue;
2079 			}
2080 
2081 			if (hdr_info->mhi_dsttype == MAC_ADDRTYPE_UNICAST)
2082 				KIINCR(bki_unknown);
2083 			else
2084 				KIINCR(bki_mbcast);
2085 			KLPINCR(blpsend, bkl_xmit);
2086 			if ((mpcopy = copymsg(mpsend)) != NULL)
2087 				mac_rx_common(blpsend->bl_mh, NULL, mpcopy);
2088 			MAC_RING_TX(blpsend->bl_mh, NULL, mpsend, mpsend);
2089 			freemsg(mpsend);
2090 			link_unref(blpsend);
2091 		}
2092 	}
2093 
2094 	/*
2095 	 * At this point, if np is non-NULL, it means that the caller needs to
2096 	 * continue on the selected link.
2097 	 */
2098 	return (mp);
2099 }
2100 
2101 /*
2102  * Extract and validate the VLAN information for a given packet.  This checks
2103  * conformance with the rules for use of the PVID on the link, and for the
2104  * allowed (configured) VLAN set.
2105  *
2106  * Returns B_TRUE if the packet passes, B_FALSE if it fails.
2107  */
2108 static boolean_t
2109 bridge_get_vlan(bridge_link_t *blp, mac_header_info_t *hdr_info, mblk_t *mp,
2110     uint16_t *vlanidp, uint16_t *tcip)
2111 {
2112 	uint16_t tci, vlanid;
2113 
2114 	if (hdr_info->mhi_bindsap == ETHERTYPE_VLAN) {
2115 		ptrdiff_t tpos = offsetof(struct ether_vlan_header, ether_tci);
2116 		ptrdiff_t mlen;
2117 
2118 		/*
2119 		 * Extract the VLAN ID information, regardless of alignment,
2120 		 * and without a pullup.  This isn't attractive, but we do this
2121 		 * to avoid having to deal with the pointers stashed in
2122 		 * hdr_info moving around or having the caller deal with a new
2123 		 * mblk_t pointer.
2124 		 */
2125 		while (mp != NULL) {
2126 			mlen = MBLKL(mp);
2127 			if (mlen > tpos && mlen > 0)
2128 				break;
2129 			tpos -= mlen;
2130 			mp = mp->b_cont;
2131 		}
2132 		if (mp == NULL)
2133 			return (B_FALSE);
2134 		tci = mp->b_rptr[tpos] << 8;
2135 		if (++tpos >= mlen) {
2136 			do {
2137 				mp = mp->b_cont;
2138 			} while (mp != NULL && MBLKL(mp) == 0);
2139 			if (mp == NULL)
2140 				return (B_FALSE);
2141 			tpos = 0;
2142 		}
2143 		tci |= mp->b_rptr[tpos];
2144 
2145 		vlanid = VLAN_ID(tci);
2146 		if (VLAN_CFI(tci) != ETHER_CFI || vlanid > VLAN_ID_MAX)
2147 			return (B_FALSE);
2148 		if (vlanid == VLAN_ID_NONE || vlanid == blp->bl_pvid)
2149 			goto input_no_vlan;
2150 		if (!BRIDGE_VLAN_ISSET(blp, vlanid))
2151 			return (B_FALSE);
2152 	} else {
2153 		tci = 0xFFFF;
2154 input_no_vlan:
2155 		/*
2156 		 * If PVID is set to zero, then untagged traffic is not
2157 		 * supported here.  Do not learn or forward.
2158 		 */
2159 		if ((vlanid = blp->bl_pvid) == VLAN_ID_NONE)
2160 			return (B_FALSE);
2161 	}
2162 
2163 	*tcip = tci;
2164 	*vlanidp = vlanid;
2165 	return (B_TRUE);
2166 }
2167 
2168 /*
2169  * Handle MAC notifications.
2170  */
2171 static void
2172 bridge_notify_cb(void *arg, mac_notify_type_t note_type)
2173 {
2174 	bridge_link_t *blp = arg;
2175 
2176 	switch (note_type) {
2177 	case MAC_NOTE_UNICST:
2178 		bridge_new_unicst(blp);
2179 		break;
2180 
2181 	case MAC_NOTE_SDU_SIZE: {
2182 		uint_t maxsdu;
2183 		bridge_inst_t *bip = blp->bl_inst;
2184 		bridge_mac_t *bmp = bip->bi_mac;
2185 		boolean_t notify = B_FALSE;
2186 		mblk_t *mlist = NULL;
2187 
2188 		mac_sdu_get(blp->bl_mh, NULL, &maxsdu);
2189 		rw_enter(&bip->bi_rwlock, RW_READER);
2190 		if (list_prev(&bip->bi_links, blp) == NULL &&
2191 		    list_next(&bip->bi_links, blp) == NULL) {
2192 			notify = (maxsdu != bmp->bm_maxsdu);
2193 			bmp->bm_maxsdu = maxsdu;
2194 		}
2195 		blp->bl_maxsdu = maxsdu;
2196 		if (maxsdu != bmp->bm_maxsdu)
2197 			link_sdu_fail(blp, B_TRUE, &mlist);
2198 		else if (notify)
2199 			(void) mac_maxsdu_update(bmp->bm_mh, maxsdu);
2200 		rw_exit(&bip->bi_rwlock);
2201 		send_up_messages(bip, mlist);
2202 		break;
2203 	}
2204 	}
2205 }
2206 
2207 /*
2208  * This is called by the MAC layer.  As with the transmit side, we're right in
2209  * the data path for all I/O on this port, so if we don't need to forward this
2210  * packet anywhere, we have to send it upwards via mac_rx_common.
2211  */
2212 static void
2213 bridge_recv_cb(mac_handle_t mh, mac_resource_handle_t rsrc, mblk_t *mpnext)
2214 {
2215 	mblk_t *mp, *mpcopy;
2216 	bridge_link_t *blp = (bridge_link_t *)mh;
2217 	bridge_inst_t *bip = blp->bl_inst;
2218 	bridge_mac_t *bmp = bip->bi_mac;
2219 	mac_header_info_t hdr_info;
2220 	uint16_t vlanid, tci;
2221 	boolean_t trillmode = B_FALSE;
2222 
2223 	KIINCR(bki_recv);
2224 	KLINCR(bkl_recv);
2225 
2226 	/*
2227 	 * Regardless of state, check for inbound TRILL packets when TRILL is
2228 	 * active.  These are pulled out of band and sent for TRILL handling.
2229 	 */
2230 	if (blp->bl_trilldata != NULL) {
2231 		void *tdp;
2232 		mblk_t *newhead;
2233 		mblk_t *tail = NULL;
2234 
2235 		mutex_enter(&blp->bl_trilllock);
2236 		if ((tdp = blp->bl_trilldata) != NULL) {
2237 			blp->bl_trillthreads++;
2238 			mutex_exit(&blp->bl_trilllock);
2239 			trillmode = B_TRUE;
2240 			newhead = mpnext;
2241 			while ((mp = mpnext) != NULL) {
2242 				boolean_t raw_isis, bridge_group;
2243 
2244 				mpnext = mp->b_next;
2245 
2246 				/*
2247 				 * If the header isn't readable, then leave on
2248 				 * the list and continue.
2249 				 */
2250 				if (mac_header_info(blp->bl_mh, mp,
2251 				    &hdr_info) != 0) {
2252 					tail = mp;
2253 					continue;
2254 				}
2255 
2256 				/*
2257 				 * The TRILL document specifies that, on
2258 				 * Ethernet alone, IS-IS packets arrive with
2259 				 * LLC rather than Ethertype, and using a
2260 				 * specific destination address.  We must check
2261 				 * for that here.  Also, we need to give BPDUs
2262 				 * to TRILL for processing.
2263 				 */
2264 				raw_isis = bridge_group = B_FALSE;
2265 				if (hdr_info.mhi_dsttype ==
2266 				    MAC_ADDRTYPE_MULTICAST) {
2267 					if (memcmp(hdr_info.mhi_daddr,
2268 					    all_isis_rbridges, ETHERADDRL) == 0)
2269 						raw_isis = B_TRUE;
2270 					else if (memcmp(hdr_info.mhi_daddr,
2271 					    bridge_group_address, ETHERADDRL) ==
2272 					    0)
2273 						bridge_group = B_TRUE;
2274 				}
2275 				if (!raw_isis && !bridge_group &&
2276 				    hdr_info.mhi_bindsap != ETHERTYPE_TRILL &&
2277 				    (hdr_info.mhi_bindsap != ETHERTYPE_VLAN ||
2278 				    /* LINTED: alignment */
2279 				    ((struct ether_vlan_header *)mp->b_rptr)->
2280 				    ether_type != htons(ETHERTYPE_TRILL))) {
2281 					tail = mp;
2282 					continue;
2283 				}
2284 
2285 				/*
2286 				 * We've got TRILL input.  Remove from the list
2287 				 * and send up through the TRILL module.  (Send
2288 				 * a copy through promiscuous receive just to
2289 				 * support snooping on TRILL.  Order isn't
2290 				 * preserved strictly, but that doesn't matter
2291 				 * here.)
2292 				 */
2293 				if (tail != NULL)
2294 					tail->b_next = mpnext;
2295 				mp->b_next = NULL;
2296 				if (mp == newhead)
2297 					newhead = mpnext;
2298 				mac_trill_snoop(blp->bl_mh, mp);
2299 				update_header(mp, &hdr_info, B_TRUE);
2300 				/*
2301 				 * On raw IS-IS and BPDU frames, we have to
2302 				 * make sure that the length is trimmed
2303 				 * properly.  We use origsap in order to cope
2304 				 * with jumbograms for IS-IS.  (Regular mac
2305 				 * can't.)
2306 				 */
2307 				if (raw_isis || bridge_group) {
2308 					size_t msglen = msgdsize(mp);
2309 
2310 					if (msglen > hdr_info.mhi_origsap) {
2311 						(void) adjmsg(mp,
2312 						    hdr_info.mhi_origsap -
2313 						    msglen);
2314 					} else if (msglen <
2315 					    hdr_info.mhi_origsap) {
2316 						freemsg(mp);
2317 						continue;
2318 					}
2319 				}
2320 				trill_recv_fn(tdp, blp, rsrc, mp, &hdr_info);
2321 			}
2322 			mpnext = newhead;
2323 			mutex_enter(&blp->bl_trilllock);
2324 			if (--blp->bl_trillthreads == 0 &&
2325 			    blp->bl_trilldata == NULL)
2326 				cv_broadcast(&blp->bl_trillwait);
2327 		}
2328 		mutex_exit(&blp->bl_trilllock);
2329 		if (mpnext == NULL)
2330 			return;
2331 	}
2332 
2333 	/*
2334 	 * If this is a TRILL RBridge, then just check whether this link is
2335 	 * used at all for forwarding.  If not, then we're done.
2336 	 */
2337 	if (trillmode) {
2338 		if (!(blp->bl_flags & BLF_TRILLACTIVE) ||
2339 		    (blp->bl_flags & BLF_SDUFAIL)) {
2340 			mac_rx_common(blp->bl_mh, rsrc, mpnext);
2341 			return;
2342 		}
2343 	} else {
2344 		/*
2345 		 * For regular (STP) bridges, if we're in blocking or listening
2346 		 * state, then do nothing.  We don't learn or forward until
2347 		 * told to do so.
2348 		 */
2349 		if (blp->bl_state == BLS_BLOCKLISTEN) {
2350 			mac_rx_common(blp->bl_mh, rsrc, mpnext);
2351 			return;
2352 		}
2353 	}
2354 
2355 	/*
2356 	 * Send a copy of the message chain up to the observability node users.
2357 	 * For TRILL, we must obey the VLAN AF rules, so we go packet-by-
2358 	 * packet.
2359 	 */
2360 	if (!trillmode && blp->bl_state == BLS_FORWARDING &&
2361 	    (bmp->bm_flags & BMF_STARTED) &&
2362 	    (mp = copymsgchain(mpnext)) != NULL) {
2363 		mac_rx(bmp->bm_mh, NULL, mp);
2364 	}
2365 
2366 	/*
2367 	 * We must be in learning or forwarding state, or using TRILL on a link
2368 	 * with one or more VLANs active.  For each packet in the list, process
2369 	 * the source address, and then attempt to forward.
2370 	 */
2371 	while ((mp = mpnext) != NULL) {
2372 		mpnext = mp->b_next;
2373 		mp->b_next = NULL;
2374 
2375 		/*
2376 		 * If we can't decode the header or if the header specifies a
2377 		 * multicast source address (impossible!), then don't bother
2378 		 * learning or forwarding, but go ahead and forward up the
2379 		 * stack for subsequent processing.
2380 		 */
2381 		if (mac_header_info(blp->bl_mh, mp, &hdr_info) != 0 ||
2382 		    (hdr_info.mhi_saddr[0] & 1) != 0) {
2383 			KIINCR(bki_drops);
2384 			KLINCR(bkl_drops);
2385 			mac_rx_common(blp->bl_mh, rsrc, mp);
2386 			continue;
2387 		}
2388 
2389 		/*
2390 		 * Extract and validate the VLAN ID for this packet.
2391 		 */
2392 		if (!bridge_get_vlan(blp, &hdr_info, mp, &vlanid, &tci) ||
2393 		    !BRIDGE_AF_ISSET(blp, vlanid)) {
2394 			mac_rx_common(blp->bl_mh, rsrc, mp);
2395 			continue;
2396 		}
2397 
2398 		if (trillmode) {
2399 			/*
2400 			 * Special test required by TRILL document: must
2401 			 * discard frames with outer address set to ESADI.
2402 			 */
2403 			if (memcmp(hdr_info.mhi_daddr, all_esadi_rbridges,
2404 			    ETHERADDRL) == 0) {
2405 				mac_rx_common(blp->bl_mh, rsrc, mp);
2406 				continue;
2407 			}
2408 
2409 			/*
2410 			 * If we're in TRILL mode, then the call above to get
2411 			 * the VLAN ID has also checked that we're the
2412 			 * appointed forwarder, so report that we're handling
2413 			 * this packet to any observability node users.
2414 			 */
2415 			if ((bmp->bm_flags & BMF_STARTED) &&
2416 			    (mpcopy = copymsg(mp)) != NULL)
2417 				mac_rx(bmp->bm_mh, NULL, mpcopy);
2418 		}
2419 
2420 		/*
2421 		 * First process the source address and learn from it.  For
2422 		 * TRILL, we learn only if we're the appointed forwarder.
2423 		 */
2424 		bridge_learn(blp, hdr_info.mhi_saddr, RBRIDGE_NICKNAME_NONE,
2425 		    vlanid);
2426 
2427 		/*
2428 		 * Now check whether we're forwarding and look up the
2429 		 * destination.  If we can forward, do so.
2430 		 */
2431 		if (trillmode || blp->bl_state == BLS_FORWARDING) {
2432 			mp = bridge_forward(blp, &hdr_info, mp, vlanid, tci,
2433 			    B_FALSE, B_FALSE);
2434 		}
2435 		if (mp != NULL)
2436 			mac_rx_common(blp->bl_mh, rsrc, mp);
2437 	}
2438 }
2439 
2440 
2441 /* ARGSUSED */
2442 static mblk_t *
2443 bridge_xmit_cb(mac_handle_t mh, mac_ring_handle_t rh, mblk_t *mpnext)
2444 {
2445 	bridge_link_t *blp = (bridge_link_t *)mh;
2446 	bridge_inst_t *bip = blp->bl_inst;
2447 	bridge_mac_t *bmp = bip->bi_mac;
2448 	mac_header_info_t hdr_info;
2449 	uint16_t vlanid, tci;
2450 	mblk_t *mp, *mpcopy;
2451 	boolean_t trillmode;
2452 
2453 	trillmode = blp->bl_trilldata != NULL;
2454 
2455 	/*
2456 	 * If we're using STP and we're in blocking or listening state, or if
2457 	 * we're using TRILL and no VLANs are active, then behave as though the
2458 	 * bridge isn't here at all, and send on the local link alone.
2459 	 */
2460 	if ((!trillmode && blp->bl_state == BLS_BLOCKLISTEN) ||
2461 	    (trillmode &&
2462 	    (!(blp->bl_flags & BLF_TRILLACTIVE) ||
2463 	    (blp->bl_flags & BLF_SDUFAIL)))) {
2464 		KIINCR(bki_sent);
2465 		KLINCR(bkl_xmit);
2466 		MAC_RING_TX(blp->bl_mh, rh, mpnext, mp);
2467 		return (mp);
2468 	}
2469 
2470 	/*
2471 	 * Send a copy of the message up to the observability node users.
2472 	 * TRILL needs to check on a packet-by-packet basis.
2473 	 */
2474 	if (!trillmode && blp->bl_state == BLS_FORWARDING &&
2475 	    (bmp->bm_flags & BMF_STARTED) &&
2476 	    (mp = copymsgchain(mpnext)) != NULL) {
2477 		mac_rx(bmp->bm_mh, NULL, mp);
2478 	}
2479 
2480 	while ((mp = mpnext) != NULL) {
2481 		mpnext = mp->b_next;
2482 		mp->b_next = NULL;
2483 
2484 		if (mac_header_info(blp->bl_mh, mp, &hdr_info) != 0) {
2485 			freemsg(mp);
2486 			continue;
2487 		}
2488 
2489 		/*
2490 		 * Extract and validate the VLAN ID for this packet.
2491 		 */
2492 		if (!bridge_get_vlan(blp, &hdr_info, mp, &vlanid, &tci) ||
2493 		    !BRIDGE_AF_ISSET(blp, vlanid)) {
2494 			freemsg(mp);
2495 			continue;
2496 		}
2497 
2498 		/*
2499 		 * If we're using TRILL, then we've now validated that we're
2500 		 * the forwarder for this VLAN, so go ahead and let
2501 		 * observability node users know about the packet.
2502 		 */
2503 		if (trillmode && (bmp->bm_flags & BMF_STARTED) &&
2504 		    (mpcopy = copymsg(mp)) != NULL) {
2505 			mac_rx(bmp->bm_mh, NULL, mpcopy);
2506 		}
2507 
2508 		/*
2509 		 * We have to learn from our own transmitted packets, because
2510 		 * there may be a Solaris DLPI raw sender (who can specify his
2511 		 * own source address) using promiscuous mode for receive.  The
2512 		 * mac layer information won't (and can't) tell us everything
2513 		 * we need to know.
2514 		 */
2515 		bridge_learn(blp, hdr_info.mhi_saddr, RBRIDGE_NICKNAME_NONE,
2516 		    vlanid);
2517 
2518 		/* attempt forwarding */
2519 		if (trillmode || blp->bl_state == BLS_FORWARDING) {
2520 			mp = bridge_forward(blp, &hdr_info, mp, vlanid, tci,
2521 			    B_FALSE, B_TRUE);
2522 		}
2523 		if (mp != NULL) {
2524 			MAC_RING_TX(blp->bl_mh, rh, mp, mp);
2525 			if (mp == NULL) {
2526 				KIINCR(bki_sent);
2527 				KLINCR(bkl_xmit);
2528 			}
2529 		}
2530 		/*
2531 		 * If we get stuck, then stop.  Don't let the user's output
2532 		 * packets get out of order.  (More importantly: don't try to
2533 		 * bridge the same packet multiple times if flow control is
2534 		 * asserted.)
2535 		 */
2536 		if (mp != NULL) {
2537 			mp->b_next = mpnext;
2538 			break;
2539 		}
2540 	}
2541 	return (mp);
2542 }
2543 
2544 /*
2545  * This is called by TRILL when it decapsulates an packet, and we must forward
2546  * locally.  On failure, we just drop.
2547  *
2548  * Note that the ingress_nick reported by TRILL must not represent this local
2549  * node.
2550  */
2551 void
2552 bridge_trill_decaps(bridge_link_t *blp, mblk_t *mp, uint16_t ingress_nick)
2553 {
2554 	mac_header_info_t hdr_info;
2555 	uint16_t vlanid, tci;
2556 	bridge_inst_t *bip = blp->bl_inst;	/* used by macros */
2557 	mblk_t *mpcopy;
2558 
2559 	if (mac_header_info(blp->bl_mh, mp, &hdr_info) != 0) {
2560 		freemsg(mp);
2561 		return;
2562 	}
2563 
2564 	/* Extract VLAN ID for this packet. */
2565 	if (hdr_info.mhi_bindsap == ETHERTYPE_VLAN) {
2566 		struct ether_vlan_header *evhp;
2567 
2568 		/* LINTED: alignment */
2569 		evhp = (struct ether_vlan_header *)mp->b_rptr;
2570 		tci = ntohs(evhp->ether_tci);
2571 		vlanid = VLAN_ID(tci);
2572 	} else {
2573 		/* Inner VLAN headers are required in TRILL data packets */
2574 		DTRACE_PROBE3(bridge__trill__decaps__novlan, bridge_link_t *,
2575 		    blp, mblk_t *, mp, uint16_t, ingress_nick);
2576 		freemsg(mp);
2577 		return;
2578 	}
2579 
2580 	/* Learn the location of this sender in the RBridge network */
2581 	bridge_learn(blp, hdr_info.mhi_saddr, ingress_nick, vlanid);
2582 
2583 	/* attempt forwarding */
2584 	mp = bridge_forward(blp, &hdr_info, mp, vlanid, tci, B_TRUE, B_TRUE);
2585 	if (mp != NULL) {
2586 		if (bridge_can_send(blp, vlanid)) {
2587 			/* Deliver a copy locally as well */
2588 			if ((mpcopy = copymsg(mp)) != NULL)
2589 				mac_rx_common(blp->bl_mh, NULL, mpcopy);
2590 			MAC_RING_TX(blp->bl_mh, NULL, mp, mp);
2591 		}
2592 		if (mp == NULL) {
2593 			KIINCR(bki_sent);
2594 			KLINCR(bkl_xmit);
2595 		} else {
2596 			freemsg(mp);
2597 		}
2598 	}
2599 }
2600 
2601 /*
2602  * This function is used by TRILL _only_ to transmit TRILL-encapsulated
2603  * packets.  It sends on a single underlying link and does not bridge.
2604  */
2605 mblk_t *
2606 bridge_trill_output(bridge_link_t *blp, mblk_t *mp)
2607 {
2608 	bridge_inst_t *bip = blp->bl_inst;	/* used by macros */
2609 
2610 	mac_trill_snoop(blp->bl_mh, mp);
2611 	MAC_RING_TX(blp->bl_mh, NULL, mp, mp);
2612 	if (mp == NULL) {
2613 		KIINCR(bki_sent);
2614 		KLINCR(bkl_xmit);
2615 	}
2616 	return (mp);
2617 }
2618 
2619 /*
2620  * Set the "appointed forwarder" flag array for this link.  TRILL controls
2621  * forwarding on a VLAN basis.  The "trillactive" flag is an optimization for
2622  * the forwarder.
2623  */
2624 void
2625 bridge_trill_setvlans(bridge_link_t *blp, const uint8_t *arr)
2626 {
2627 	int i;
2628 	uint_t newflags = 0;
2629 
2630 	for (i = 0; i < BRIDGE_VLAN_ARR_SIZE; i++) {
2631 		if ((blp->bl_afs[i] = arr[i]) != 0)
2632 			newflags = BLF_TRILLACTIVE;
2633 	}
2634 	blp->bl_flags = (blp->bl_flags & ~BLF_TRILLACTIVE) | newflags;
2635 }
2636 
2637 void
2638 bridge_trill_flush(bridge_link_t *blp, uint16_t vlan, boolean_t dotrill)
2639 {
2640 	bridge_inst_t *bip = blp->bl_inst;
2641 	bridge_fwd_t *bfp, *bfnext;
2642 	avl_tree_t fwd_scavenge;
2643 	int i;
2644 
2645 	_NOTE(ARGUNUSED(vlan));
2646 
2647 	avl_create(&fwd_scavenge, fwd_compare, sizeof (bridge_fwd_t),
2648 	    offsetof(bridge_fwd_t, bf_node));
2649 	rw_enter(&bip->bi_rwlock, RW_WRITER);
2650 	bfnext = avl_first(&bip->bi_fwd);
2651 	while ((bfp = bfnext) != NULL) {
2652 		bfnext = AVL_NEXT(&bip->bi_fwd, bfp);
2653 		if (bfp->bf_flags & BFF_LOCALADDR)
2654 			continue;
2655 		if (dotrill) {
2656 			/* port doesn't matter if we're flushing TRILL */
2657 			if (bfp->bf_trill_nick == RBRIDGE_NICKNAME_NONE)
2658 				continue;
2659 		} else {
2660 			if (bfp->bf_trill_nick != RBRIDGE_NICKNAME_NONE)
2661 				continue;
2662 			for (i = 0; i < bfp->bf_nlinks; i++) {
2663 				if (bfp->bf_links[i] == blp)
2664 					break;
2665 			}
2666 			if (i >= bfp->bf_nlinks)
2667 				continue;
2668 		}
2669 		ASSERT(bfp->bf_flags & BFF_INTREE);
2670 		avl_remove(&bip->bi_fwd, bfp);
2671 		bfp->bf_flags &= ~BFF_INTREE;
2672 		avl_add(&fwd_scavenge, bfp);
2673 	}
2674 	rw_exit(&bip->bi_rwlock);
2675 	bfnext = avl_first(&fwd_scavenge);
2676 	while ((bfp = bfnext) != NULL) {
2677 		bfnext = AVL_NEXT(&fwd_scavenge, bfp);
2678 		avl_remove(&fwd_scavenge, bfp);
2679 		fwd_unref(bfp);
2680 	}
2681 	avl_destroy(&fwd_scavenge);
2682 }
2683 
2684 /*
2685  * Let the mac module take or drop a reference to a bridge link.  When this is
2686  * called, the mac module is holding the mi_bridge_lock, so the link cannot be
2687  * in the process of entering or leaving a bridge.
2688  */
2689 static void
2690 bridge_ref_cb(mac_handle_t mh, boolean_t hold)
2691 {
2692 	bridge_link_t *blp = (bridge_link_t *)mh;
2693 
2694 	if (hold)
2695 		atomic_inc_uint(&blp->bl_refs);
2696 	else
2697 		link_unref(blp);
2698 }
2699 
2700 /*
2701  * Handle link state changes reported by the mac layer.  This acts as a filter
2702  * for link state changes: if a link is reporting down, but there are other
2703  * links still up on the bridge, then the state is changed to "up."  When the
2704  * last link goes down, all are marked down, and when the first link goes up,
2705  * all are marked up.  (Recursion is avoided by the use of the "redo" function.)
2706  *
2707  * We treat unknown as equivalent to "up."
2708  */
2709 static link_state_t
2710 bridge_ls_cb(mac_handle_t mh, link_state_t newls)
2711 {
2712 	bridge_link_t *blp = (bridge_link_t *)mh;
2713 	bridge_link_t *blcmp;
2714 	bridge_inst_t *bip;
2715 	bridge_mac_t *bmp;
2716 
2717 	if (newls != LINK_STATE_DOWN && blp->bl_linkstate != LINK_STATE_DOWN ||
2718 	    (blp->bl_flags & (BLF_DELETED|BLF_SDUFAIL))) {
2719 		blp->bl_linkstate = newls;
2720 		return (newls);
2721 	}
2722 
2723 	/*
2724 	 * Scan first to see if there are any other non-down links.  If there
2725 	 * are, then we're done.  Otherwise, if all others are down, then the
2726 	 * state of this link is the state of the bridge.
2727 	 */
2728 	bip = blp->bl_inst;
2729 	rw_enter(&bip->bi_rwlock, RW_WRITER);
2730 	for (blcmp = list_head(&bip->bi_links); blcmp != NULL;
2731 	    blcmp = list_next(&bip->bi_links, blcmp)) {
2732 		if (blcmp != blp &&
2733 		    !(blcmp->bl_flags & (BLF_DELETED|BLF_SDUFAIL)) &&
2734 		    blcmp->bl_linkstate != LINK_STATE_DOWN)
2735 			break;
2736 	}
2737 
2738 	if (blcmp != NULL) {
2739 		/*
2740 		 * If there are other links that are considered up, then tell
2741 		 * the caller that the link is actually still up, regardless of
2742 		 * this link's underlying state.
2743 		 */
2744 		blp->bl_linkstate = newls;
2745 		newls = LINK_STATE_UP;
2746 	} else if (blp->bl_linkstate != newls) {
2747 		/*
2748 		 * If we've found no other 'up' links, and this link has
2749 		 * changed state, then report the new state of the bridge to
2750 		 * all other clients.
2751 		 */
2752 		blp->bl_linkstate = newls;
2753 		for (blcmp = list_head(&bip->bi_links); blcmp != NULL;
2754 		    blcmp = list_next(&bip->bi_links, blcmp)) {
2755 			if (blcmp != blp && !(blcmp->bl_flags & BLF_DELETED))
2756 				mac_link_redo(blcmp->bl_mh, newls);
2757 		}
2758 		bmp = bip->bi_mac;
2759 		if ((bmp->bm_linkstate = newls) != LINK_STATE_DOWN)
2760 			bmp->bm_linkstate = LINK_STATE_UP;
2761 		mac_link_redo(bmp->bm_mh, bmp->bm_linkstate);
2762 	}
2763 	rw_exit(&bip->bi_rwlock);
2764 	return (newls);
2765 }
2766 
2767 static void
2768 bridge_add_link(void *arg)
2769 {
2770 	mblk_t *mp = arg;
2771 	bridge_stream_t *bsp;
2772 	bridge_inst_t *bip, *bipt;
2773 	bridge_mac_t *bmp;
2774 	datalink_id_t linkid;
2775 	int err;
2776 	mac_handle_t mh;
2777 	uint_t maxsdu;
2778 	bridge_link_t *blp = NULL, *blpt;
2779 	const mac_info_t *mip;
2780 	boolean_t macopen = B_FALSE;
2781 	char linkname[MAXLINKNAMELEN];
2782 	char kstatname[KSTAT_STRLEN];
2783 	int i;
2784 	link_state_t linkstate;
2785 	mblk_t *mlist;
2786 
2787 	bsp = (bridge_stream_t *)mp->b_next;
2788 	mp->b_next = NULL;
2789 	bip = bsp->bs_inst;
2790 	/* LINTED: alignment */
2791 	linkid = *(datalink_id_t *)mp->b_cont->b_rptr;
2792 
2793 	/*
2794 	 * First make sure that there is no other bridge that has this link.
2795 	 * We don't want to overlap operations from two bridges; the MAC layer
2796 	 * supports only one bridge on a given MAC at a time.
2797 	 *
2798 	 * We rely on the fact that there's just one taskq thread for the
2799 	 * bridging module: once we've checked for a duplicate, we can drop the
2800 	 * lock, because no other thread could possibly be adding another link
2801 	 * until we're done.
2802 	 */
2803 	mutex_enter(&inst_lock);
2804 	for (bipt = list_head(&inst_list); bipt != NULL;
2805 	    bipt = list_next(&inst_list, bipt)) {
2806 		rw_enter(&bipt->bi_rwlock, RW_READER);
2807 		for (blpt = list_head(&bipt->bi_links); blpt != NULL;
2808 		    blpt = list_next(&bipt->bi_links, blpt)) {
2809 			if (linkid == blpt->bl_linkid)
2810 				break;
2811 		}
2812 		rw_exit(&bipt->bi_rwlock);
2813 		if (blpt != NULL)
2814 			break;
2815 	}
2816 	mutex_exit(&inst_lock);
2817 	if (bipt != NULL) {
2818 		err = EBUSY;
2819 		goto fail;
2820 	}
2821 
2822 	if ((err = mac_open_by_linkid(linkid, &mh)) != 0)
2823 		goto fail;
2824 	macopen = B_TRUE;
2825 
2826 	/* we bridge only Ethernet */
2827 	mip = mac_info(mh);
2828 	if (mip->mi_media != DL_ETHER) {
2829 		err = ENOTSUP;
2830 		goto fail;
2831 	}
2832 
2833 	/*
2834 	 * Get the current maximum SDU on this interface.  If there are other
2835 	 * links on the bridge, then this one must match, or it errors out.
2836 	 * Otherwise, the first link becomes the standard for the new bridge.
2837 	 */
2838 	mac_sdu_get(mh, NULL, &maxsdu);
2839 	bmp = bip->bi_mac;
2840 	if (list_is_empty(&bip->bi_links)) {
2841 		bmp->bm_maxsdu = maxsdu;
2842 		(void) mac_maxsdu_update(bmp->bm_mh, maxsdu);
2843 	}
2844 
2845 	/* figure the kstat name; also used as the mac client name */
2846 	i = MBLKL(mp->b_cont) - sizeof (datalink_id_t);
2847 	if (i < 0 || i >= MAXLINKNAMELEN)
2848 		i = MAXLINKNAMELEN - 1;
2849 	bcopy(mp->b_cont->b_rptr + sizeof (datalink_id_t), linkname, i);
2850 	linkname[i] = '\0';
2851 	(void) snprintf(kstatname, sizeof (kstatname), "%s-%s", bip->bi_name,
2852 	    linkname);
2853 
2854 	if ((blp = kmem_zalloc(sizeof (*blp), KM_NOSLEEP)) == NULL) {
2855 		err = ENOMEM;
2856 		goto fail;
2857 	}
2858 	blp->bl_lfailmp = allocb(sizeof (bridge_ctl_t), BPRI_MED);
2859 	if (blp->bl_lfailmp == NULL) {
2860 		kmem_free(blp, sizeof (*blp));
2861 		blp = NULL;
2862 		err = ENOMEM;
2863 		goto fail;
2864 	}
2865 
2866 	blp->bl_refs = 1;
2867 	atomic_inc_uint(&bip->bi_refs);
2868 	blp->bl_inst = bip;
2869 	blp->bl_mh = mh;
2870 	blp->bl_linkid = linkid;
2871 	blp->bl_maxsdu = maxsdu;
2872 	cv_init(&blp->bl_trillwait, NULL, CV_DRIVER, NULL);
2873 	mutex_init(&blp->bl_trilllock, NULL, MUTEX_DRIVER, NULL);
2874 	(void) memset(blp->bl_afs, 0xff, sizeof (blp->bl_afs));
2875 
2876 	err = mac_client_open(mh, &blp->bl_mch, kstatname, 0);
2877 	if (err != 0)
2878 		goto fail;
2879 	blp->bl_flags |= BLF_CLIENT_OPEN;
2880 
2881 	err = mac_margin_add(mh, &blp->bl_margin, B_TRUE);
2882 	if (err != 0)
2883 		goto fail;
2884 	blp->bl_flags |= BLF_MARGIN_ADDED;
2885 
2886 	blp->bl_mnh = mac_notify_add(mh, bridge_notify_cb, blp);
2887 
2888 	/* Enable Bridging on the link */
2889 	err = mac_bridge_set(mh, (mac_handle_t)blp);
2890 	if (err != 0)
2891 		goto fail;
2892 	blp->bl_flags |= BLF_SET_BRIDGE;
2893 
2894 	err = mac_promisc_add(blp->bl_mch, MAC_CLIENT_PROMISC_ALL, NULL,
2895 	    blp, &blp->bl_mphp, MAC_PROMISC_FLAGS_NO_TX_LOOP);
2896 	if (err != 0)
2897 		goto fail;
2898 	blp->bl_flags |= BLF_PROM_ADDED;
2899 
2900 	bridge_new_unicst(blp);
2901 
2902 	blp->bl_ksp = kstat_setup((kstat_named_t *)&blp->bl_kstats,
2903 	    link_kstats_list, Dim(link_kstats_list), kstatname);
2904 
2905 	/*
2906 	 * The link holds a reference to the bridge instance, so that the
2907 	 * instance can't go away before the link is freed.  The insertion into
2908 	 * bi_links holds a reference on the link (reference set to 1 above).
2909 	 * When marking as removed from bi_links (BLF_DELETED), drop the
2910 	 * reference on the link. When freeing the link, drop the reference on
2911 	 * the instance. BLF_LINK_ADDED tracks link insertion in bi_links list.
2912 	 */
2913 	rw_enter(&bip->bi_rwlock, RW_WRITER);
2914 	list_insert_tail(&bip->bi_links, blp);
2915 	blp->bl_flags |= BLF_LINK_ADDED;
2916 
2917 	/*
2918 	 * If the new link is no good on this bridge, then let the daemon know
2919 	 * about the problem.
2920 	 */
2921 	mlist = NULL;
2922 	if (maxsdu != bmp->bm_maxsdu)
2923 		link_sdu_fail(blp, B_TRUE, &mlist);
2924 	rw_exit(&bip->bi_rwlock);
2925 	send_up_messages(bip, mlist);
2926 
2927 	/*
2928 	 * Trigger a link state update so that if this link is the first one
2929 	 * "up" in the bridge, then we notify everyone.  This triggers a trip
2930 	 * through bridge_ls_cb.
2931 	 */
2932 	linkstate = mac_stat_get(mh, MAC_STAT_LOWLINK_STATE);
2933 	blp->bl_linkstate = LINK_STATE_DOWN;
2934 	mac_link_update(mh, linkstate);
2935 
2936 	/*
2937 	 * We now need to report back to the stream that invoked us, and then
2938 	 * drop the reference on the stream that we're holding.
2939 	 */
2940 	miocack(bsp->bs_wq, mp, 0, 0);
2941 	stream_unref(bsp);
2942 	return;
2943 
2944 fail:
2945 	if (blp == NULL) {
2946 		if (macopen)
2947 			mac_close(mh);
2948 	} else {
2949 		link_shutdown(blp);
2950 	}
2951 	miocnak(bsp->bs_wq, mp, 0, err);
2952 	stream_unref(bsp);
2953 }
2954 
2955 static void
2956 bridge_rem_link(void *arg)
2957 {
2958 	mblk_t *mp = arg;
2959 	bridge_stream_t *bsp;
2960 	bridge_inst_t *bip;
2961 	bridge_mac_t *bmp;
2962 	datalink_id_t linkid;
2963 	bridge_link_t *blp, *blsave;
2964 	boolean_t found;
2965 	mblk_t *mlist;
2966 
2967 	bsp = (bridge_stream_t *)mp->b_next;
2968 	mp->b_next = NULL;
2969 	bip = bsp->bs_inst;
2970 	/* LINTED: alignment */
2971 	linkid = *(datalink_id_t *)mp->b_cont->b_rptr;
2972 
2973 	/*
2974 	 * We become reader here so that we can loop over the other links and
2975 	 * deliver link up/down notification.
2976 	 */
2977 	rw_enter(&bip->bi_rwlock, RW_READER);
2978 	found = B_FALSE;
2979 	for (blp = list_head(&bip->bi_links); blp != NULL;
2980 	    blp = list_next(&bip->bi_links, blp)) {
2981 		if (blp->bl_linkid == linkid &&
2982 		    !(blp->bl_flags & BLF_DELETED)) {
2983 			blp->bl_flags |= BLF_DELETED;
2984 			(void) ddi_taskq_dispatch(bridge_taskq, link_shutdown,
2985 			    blp, DDI_SLEEP);
2986 			found = B_TRUE;
2987 			break;
2988 		}
2989 	}
2990 
2991 	/*
2992 	 * Check if this link is up and the remainder of the links are all
2993 	 * down.
2994 	 */
2995 	if (blp != NULL && blp->bl_linkstate != LINK_STATE_DOWN) {
2996 		for (blp = list_head(&bip->bi_links); blp != NULL;
2997 		    blp = list_next(&bip->bi_links, blp)) {
2998 			if (blp->bl_linkstate != LINK_STATE_DOWN &&
2999 			    !(blp->bl_flags & (BLF_DELETED|BLF_SDUFAIL)))
3000 				break;
3001 		}
3002 		if (blp == NULL) {
3003 			for (blp = list_head(&bip->bi_links); blp != NULL;
3004 			    blp = list_next(&bip->bi_links, blp)) {
3005 				if (!(blp->bl_flags & BLF_DELETED))
3006 					mac_link_redo(blp->bl_mh,
3007 					    LINK_STATE_DOWN);
3008 			}
3009 			bmp = bip->bi_mac;
3010 			bmp->bm_linkstate = LINK_STATE_DOWN;
3011 			mac_link_redo(bmp->bm_mh, LINK_STATE_DOWN);
3012 		}
3013 	}
3014 
3015 	/*
3016 	 * Check if there's just one working link left on the bridge.  If so,
3017 	 * then that link is now authoritative for bridge MTU.
3018 	 */
3019 	blsave = NULL;
3020 	for (blp = list_head(&bip->bi_links); blp != NULL;
3021 	    blp = list_next(&bip->bi_links, blp)) {
3022 		if (!(blp->bl_flags & BLF_DELETED)) {
3023 			if (blsave == NULL)
3024 				blsave = blp;
3025 			else
3026 				break;
3027 		}
3028 	}
3029 	mlist = NULL;
3030 	bmp = bip->bi_mac;
3031 	if (blsave != NULL && blp == NULL &&
3032 	    blsave->bl_maxsdu != bmp->bm_maxsdu) {
3033 		bmp->bm_maxsdu = blsave->bl_maxsdu;
3034 		(void) mac_maxsdu_update(bmp->bm_mh, blsave->bl_maxsdu);
3035 		link_sdu_fail(blsave, B_FALSE, &mlist);
3036 	}
3037 	rw_exit(&bip->bi_rwlock);
3038 	send_up_messages(bip, mlist);
3039 
3040 	if (found)
3041 		miocack(bsp->bs_wq, mp, 0, 0);
3042 	else
3043 		miocnak(bsp->bs_wq, mp, 0, ENOENT);
3044 	stream_unref(bsp);
3045 }
3046 
3047 /*
3048  * This function intentionally returns with bi_rwlock held; it is intended for
3049  * quick checks and updates.
3050  */
3051 static bridge_link_t *
3052 enter_link(bridge_inst_t *bip, datalink_id_t linkid)
3053 {
3054 	bridge_link_t *blp;
3055 
3056 	rw_enter(&bip->bi_rwlock, RW_READER);
3057 	for (blp = list_head(&bip->bi_links); blp != NULL;
3058 	    blp = list_next(&bip->bi_links, blp)) {
3059 		if (blp->bl_linkid == linkid && !(blp->bl_flags & BLF_DELETED))
3060 			break;
3061 	}
3062 	return (blp);
3063 }
3064 
3065 static void
3066 bridge_ioctl(queue_t *wq, mblk_t *mp)
3067 {
3068 	bridge_stream_t *bsp = wq->q_ptr;
3069 	bridge_inst_t *bip;
3070 	struct iocblk *iop;
3071 	int rc = EINVAL;
3072 	int len = 0;
3073 	bridge_link_t *blp;
3074 	cred_t *cr;
3075 
3076 	/* LINTED: alignment */
3077 	iop = (struct iocblk *)mp->b_rptr;
3078 
3079 	/*
3080 	 * For now, all of the bridge ioctls are privileged.
3081 	 */
3082 	if ((cr = msg_getcred(mp, NULL)) == NULL)
3083 		cr = iop->ioc_cr;
3084 	if (cr != NULL && secpolicy_net_config(cr, B_FALSE) != 0) {
3085 		miocnak(wq, mp, 0, EPERM);
3086 		return;
3087 	}
3088 
3089 	switch (iop->ioc_cmd) {
3090 	case BRIOC_NEWBRIDGE: {
3091 		bridge_newbridge_t *bnb;
3092 
3093 		if (bsp->bs_inst != NULL ||
3094 		    (rc = miocpullup(mp, sizeof (bridge_newbridge_t))) != 0)
3095 			break;
3096 		/* LINTED: alignment */
3097 		bnb = (bridge_newbridge_t *)mp->b_cont->b_rptr;
3098 		bnb->bnb_name[MAXNAMELEN-1] = '\0';
3099 		rc = bridge_create(bnb->bnb_linkid, bnb->bnb_name, &bip, cr);
3100 		if (rc != 0)
3101 			break;
3102 
3103 		rw_enter(&bip->bi_rwlock, RW_WRITER);
3104 		if (bip->bi_control != NULL) {
3105 			rw_exit(&bip->bi_rwlock);
3106 			bridge_unref(bip);
3107 			rc = EBUSY;
3108 		} else {
3109 			atomic_inc_uint(&bip->bi_refs);
3110 			bsp->bs_inst = bip;	/* stream holds reference */
3111 			bip->bi_control = bsp;
3112 			rw_exit(&bip->bi_rwlock);
3113 			rc = 0;
3114 		}
3115 		break;
3116 	}
3117 
3118 	case BRIOC_ADDLINK:
3119 		if ((bip = bsp->bs_inst) == NULL ||
3120 		    (rc = miocpullup(mp, sizeof (datalink_id_t))) != 0)
3121 			break;
3122 		/*
3123 		 * We cannot perform the action in this thread, because we're
3124 		 * not in process context, and we may already be holding
3125 		 * MAC-related locks.  Place the request on taskq.
3126 		 */
3127 		mp->b_next = (mblk_t *)bsp;
3128 		stream_ref(bsp);
3129 		(void) ddi_taskq_dispatch(bridge_taskq, bridge_add_link, mp,
3130 		    DDI_SLEEP);
3131 		return;
3132 
3133 	case BRIOC_REMLINK:
3134 		if ((bip = bsp->bs_inst) == NULL ||
3135 		    (rc = miocpullup(mp, sizeof (datalink_id_t))) != 0)
3136 			break;
3137 		/*
3138 		 * We cannot perform the action in this thread, because we're
3139 		 * not in process context, and we may already be holding
3140 		 * MAC-related locks.  Place the request on taskq.
3141 		 */
3142 		mp->b_next = (mblk_t *)bsp;
3143 		stream_ref(bsp);
3144 		(void) ddi_taskq_dispatch(bridge_taskq, bridge_rem_link, mp,
3145 		    DDI_SLEEP);
3146 		return;
3147 
3148 	case BRIOC_SETSTATE: {
3149 		bridge_setstate_t *bss;
3150 
3151 		if ((bip = bsp->bs_inst) == NULL ||
3152 		    (rc = miocpullup(mp, sizeof (*bss))) != 0)
3153 			break;
3154 		/* LINTED: alignment */
3155 		bss = (bridge_setstate_t *)mp->b_cont->b_rptr;
3156 		if ((blp = enter_link(bip, bss->bss_linkid)) == NULL) {
3157 			rc = ENOENT;
3158 		} else {
3159 			rc = 0;
3160 			blp->bl_state = bss->bss_state;
3161 		}
3162 		rw_exit(&bip->bi_rwlock);
3163 		break;
3164 	}
3165 
3166 	case BRIOC_SETPVID: {
3167 		bridge_setpvid_t *bsv;
3168 
3169 		if ((bip = bsp->bs_inst) == NULL ||
3170 		    (rc = miocpullup(mp, sizeof (*bsv))) != 0)
3171 			break;
3172 		/* LINTED: alignment */
3173 		bsv = (bridge_setpvid_t *)mp->b_cont->b_rptr;
3174 		if (bsv->bsv_vlan > VLAN_ID_MAX)
3175 			break;
3176 		if ((blp = enter_link(bip, bsv->bsv_linkid)) == NULL) {
3177 			rc = ENOENT;
3178 		} else if (blp->bl_pvid == bsv->bsv_vlan) {
3179 			rc = 0;
3180 		} else {
3181 			rc = 0;
3182 			BRIDGE_VLAN_CLR(blp, blp->bl_pvid);
3183 			blp->bl_pvid = bsv->bsv_vlan;
3184 			if (blp->bl_pvid != 0)
3185 				BRIDGE_VLAN_SET(blp, blp->bl_pvid);
3186 		}
3187 		rw_exit(&bip->bi_rwlock);
3188 		break;
3189 	}
3190 
3191 	case BRIOC_VLANENAB: {
3192 		bridge_vlanenab_t *bve;
3193 
3194 		if ((bip = bsp->bs_inst) == NULL ||
3195 		    (rc = miocpullup(mp, sizeof (*bve))) != 0)
3196 			break;
3197 		/* LINTED: alignment */
3198 		bve = (bridge_vlanenab_t *)mp->b_cont->b_rptr;
3199 		if (bve->bve_vlan > VLAN_ID_MAX)
3200 			break;
3201 		if ((blp = enter_link(bip, bve->bve_linkid)) == NULL) {
3202 			rc = ENOENT;
3203 		} else {
3204 			rc = 0;
3205 			/* special case: vlan 0 means "all" */
3206 			if (bve->bve_vlan == 0) {
3207 				(void) memset(blp->bl_vlans,
3208 				    bve->bve_onoff ? ~0 : 0,
3209 				    sizeof (blp->bl_vlans));
3210 				BRIDGE_VLAN_CLR(blp, 0);
3211 				if (blp->bl_pvid != 0)
3212 					BRIDGE_VLAN_SET(blp, blp->bl_pvid);
3213 			} else if (bve->bve_vlan == blp->bl_pvid) {
3214 				rc = EINVAL;
3215 			} else if (bve->bve_onoff) {
3216 				BRIDGE_VLAN_SET(blp, bve->bve_vlan);
3217 			} else {
3218 				BRIDGE_VLAN_CLR(blp, bve->bve_vlan);
3219 			}
3220 		}
3221 		rw_exit(&bip->bi_rwlock);
3222 		break;
3223 	}
3224 
3225 	case BRIOC_FLUSHFWD: {
3226 		bridge_flushfwd_t *bff;
3227 		bridge_fwd_t *bfp, *bfnext;
3228 		avl_tree_t fwd_scavenge;
3229 		int i;
3230 
3231 		if ((bip = bsp->bs_inst) == NULL ||
3232 		    (rc = miocpullup(mp, sizeof (*bff))) != 0)
3233 			break;
3234 		/* LINTED: alignment */
3235 		bff = (bridge_flushfwd_t *)mp->b_cont->b_rptr;
3236 		rw_enter(&bip->bi_rwlock, RW_WRITER);
3237 		/* This case means "all" */
3238 		if (bff->bff_linkid == DATALINK_INVALID_LINKID) {
3239 			blp = NULL;
3240 		} else {
3241 			for (blp = list_head(&bip->bi_links); blp != NULL;
3242 			    blp = list_next(&bip->bi_links, blp)) {
3243 				if (blp->bl_linkid == bff->bff_linkid &&
3244 				    !(blp->bl_flags & BLF_DELETED))
3245 					break;
3246 			}
3247 			if (blp == NULL) {
3248 				rc = ENOENT;
3249 				rw_exit(&bip->bi_rwlock);
3250 				break;
3251 			}
3252 		}
3253 		avl_create(&fwd_scavenge, fwd_compare, sizeof (bridge_fwd_t),
3254 		    offsetof(bridge_fwd_t, bf_node));
3255 		bfnext = avl_first(&bip->bi_fwd);
3256 		while ((bfp = bfnext) != NULL) {
3257 			bfnext = AVL_NEXT(&bip->bi_fwd, bfp);
3258 			if (bfp->bf_flags & BFF_LOCALADDR)
3259 				continue;
3260 			if (blp != NULL) {
3261 				for (i = 0; i < bfp->bf_maxlinks; i++) {
3262 					if (bfp->bf_links[i] == blp)
3263 						break;
3264 				}
3265 				/*
3266 				 * If the link is there and we're excluding,
3267 				 * then skip.  If the link is not there and
3268 				 * we're doing only that link, then skip.
3269 				 */
3270 				if ((i < bfp->bf_maxlinks) == bff->bff_exclude)
3271 					continue;
3272 			}
3273 			ASSERT(bfp->bf_flags & BFF_INTREE);
3274 			avl_remove(&bip->bi_fwd, bfp);
3275 			bfp->bf_flags &= ~BFF_INTREE;
3276 			avl_add(&fwd_scavenge, bfp);
3277 		}
3278 		rw_exit(&bip->bi_rwlock);
3279 		bfnext = avl_first(&fwd_scavenge);
3280 		while ((bfp = bfnext) != NULL) {
3281 			bfnext = AVL_NEXT(&fwd_scavenge, bfp);
3282 			avl_remove(&fwd_scavenge, bfp);
3283 			fwd_unref(bfp);	/* drop tree reference */
3284 		}
3285 		avl_destroy(&fwd_scavenge);
3286 		break;
3287 	}
3288 
3289 	case BRIOC_TABLEMAX:
3290 		if ((bip = bsp->bs_inst) == NULL ||
3291 		    (rc = miocpullup(mp, sizeof (uint32_t))) != 0)
3292 			break;
3293 		/* LINTED: alignment */
3294 		bip->bi_tablemax = *(uint32_t *)mp->b_cont->b_rptr;
3295 		break;
3296 	}
3297 
3298 	if (rc == 0)
3299 		miocack(wq, mp, len, 0);
3300 	else
3301 		miocnak(wq, mp, 0, rc);
3302 }
3303 
3304 static void
3305 bridge_wput(queue_t *wq, mblk_t *mp)
3306 {
3307 	switch (DB_TYPE(mp)) {
3308 	case M_IOCTL:
3309 		bridge_ioctl(wq, mp);
3310 		break;
3311 	case M_FLUSH:
3312 		if (*mp->b_rptr & FLUSHW)
3313 			*mp->b_rptr &= ~FLUSHW;
3314 		if (*mp->b_rptr & FLUSHR)
3315 			qreply(wq, mp);
3316 		else
3317 			freemsg(mp);
3318 		break;
3319 	default:
3320 		freemsg(mp);
3321 		break;
3322 	}
3323 }
3324 
3325 /*
3326  * This function allocates the main data structures for the bridge driver and
3327  * connects us into devfs.
3328  */
3329 static void
3330 bridge_inst_init(void)
3331 {
3332 	bridge_scan_interval = 5 * drv_usectohz(1000000);
3333 	bridge_fwd_age = 25 * drv_usectohz(1000000);
3334 
3335 	rw_init(&bmac_rwlock, NULL, RW_DRIVER, NULL);
3336 	list_create(&bmac_list, sizeof (bridge_mac_t),
3337 	    offsetof(bridge_mac_t, bm_node));
3338 	list_create(&inst_list, sizeof (bridge_inst_t),
3339 	    offsetof(bridge_inst_t, bi_node));
3340 	cv_init(&inst_cv, NULL, CV_DRIVER, NULL);
3341 	mutex_init(&inst_lock, NULL, MUTEX_DRIVER, NULL);
3342 	cv_init(&stream_ref_cv, NULL, CV_DRIVER, NULL);
3343 	mutex_init(&stream_ref_lock, NULL, MUTEX_DRIVER, NULL);
3344 
3345 	mac_bridge_vectors(bridge_xmit_cb, bridge_recv_cb, bridge_ref_cb,
3346 	    bridge_ls_cb);
3347 }
3348 
3349 /*
3350  * This function disconnects from devfs and destroys all data structures in
3351  * preparation for unload.  It's assumed that there are no active bridge
3352  * references left at this point.
3353  */
3354 static void
3355 bridge_inst_fini(void)
3356 {
3357 	mac_bridge_vectors(NULL, NULL, NULL, NULL);
3358 	if (bridge_timerid != 0)
3359 		(void) untimeout(bridge_timerid);
3360 	rw_destroy(&bmac_rwlock);
3361 	list_destroy(&bmac_list);
3362 	list_destroy(&inst_list);
3363 	cv_destroy(&inst_cv);
3364 	mutex_destroy(&inst_lock);
3365 	cv_destroy(&stream_ref_cv);
3366 	mutex_destroy(&stream_ref_lock);
3367 }
3368 
3369 /*
3370  * bridge_attach()
3371  *
3372  * Description:
3373  *    Attach bridge driver to the system.
3374  */
3375 static int
3376 bridge_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
3377 {
3378 	if (cmd != DDI_ATTACH)
3379 		return (DDI_FAILURE);
3380 
3381 	if (ddi_create_minor_node(dip, BRIDGE_CTL, S_IFCHR, 0, DDI_PSEUDO,
3382 	    CLONE_DEV) == DDI_FAILURE) {
3383 		return (DDI_FAILURE);
3384 	}
3385 
3386 	if (dld_ioc_register(BRIDGE_IOC, bridge_ioc_list,
3387 	    DLDIOCCNT(bridge_ioc_list)) != 0) {
3388 		ddi_remove_minor_node(dip, BRIDGE_CTL);
3389 		return (DDI_FAILURE);
3390 	}
3391 
3392 	bridge_dev_info = dip;
3393 	bridge_major = ddi_driver_major(dip);
3394 	bridge_taskq = ddi_taskq_create(dip, BRIDGE_DEV_NAME, 1,
3395 	    TASKQ_DEFAULTPRI, 0);
3396 	return (DDI_SUCCESS);
3397 }
3398 
3399 /*
3400  * bridge_detach()
3401  *
3402  * Description:
3403  *    Detach an interface to the system.
3404  */
3405 static int
3406 bridge_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
3407 {
3408 	if (cmd != DDI_DETACH)
3409 		return (DDI_FAILURE);
3410 
3411 	ddi_remove_minor_node(dip, NULL);
3412 	ddi_taskq_destroy(bridge_taskq);
3413 	bridge_dev_info = NULL;
3414 	return (DDI_SUCCESS);
3415 }
3416 
3417 /*
3418  * bridge_info()
3419  *
3420  * Description:
3421  *    Translate "dev_t" to a pointer to the associated "dev_info_t".
3422  */
3423 /* ARGSUSED */
3424 static int
3425 bridge_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
3426 	void **result)
3427 {
3428 	int	rc;
3429 
3430 	switch (infocmd) {
3431 	case DDI_INFO_DEVT2DEVINFO:
3432 		if (bridge_dev_info == NULL) {
3433 			rc = DDI_FAILURE;
3434 		} else {
3435 			*result = (void *)bridge_dev_info;
3436 			rc = DDI_SUCCESS;
3437 		}
3438 		break;
3439 	case DDI_INFO_DEVT2INSTANCE:
3440 		*result = NULL;
3441 		rc = DDI_SUCCESS;
3442 		break;
3443 	default:
3444 		rc = DDI_FAILURE;
3445 		break;
3446 	}
3447 	return (rc);
3448 }
3449 
3450 static struct module_info bridge_modinfo = {
3451 	2105,			/* mi_idnum */
3452 	BRIDGE_DEV_NAME,	/* mi_idname */
3453 	0,			/* mi_minpsz */
3454 	16384,			/* mi_maxpsz */
3455 	65536,			/* mi_hiwat */
3456 	128			/* mi_lowat */
3457 };
3458 
3459 static struct qinit bridge_rinit = {
3460 	NULL,			/* qi_putp */
3461 	NULL,			/* qi_srvp */
3462 	bridge_open,		/* qi_qopen */
3463 	bridge_close,		/* qi_qclose */
3464 	NULL,			/* qi_qadmin */
3465 	&bridge_modinfo,	/* qi_minfo */
3466 	NULL			/* qi_mstat */
3467 };
3468 
3469 static struct qinit bridge_winit = {
3470 	(int (*)())bridge_wput, /* qi_putp */
3471 	NULL,			/* qi_srvp */
3472 	NULL,			/* qi_qopen */
3473 	NULL,			/* qi_qclose */
3474 	NULL,			/* qi_qadmin */
3475 	&bridge_modinfo,	/* qi_minfo */
3476 	NULL			/* qi_mstat */
3477 };
3478 
3479 static struct streamtab bridge_tab = {
3480 	&bridge_rinit,	/* st_rdinit */
3481 	&bridge_winit	/* st_wrinit */
3482 };
3483 
3484 /* No STREAMS perimeters; we do all our own locking */
3485 DDI_DEFINE_STREAM_OPS(bridge_ops, nulldev, nulldev, bridge_attach,
3486     bridge_detach, nodev, bridge_info, D_NEW | D_MP, &bridge_tab,
3487     ddi_quiesce_not_supported);
3488 
3489 static struct modldrv modldrv = {
3490 	&mod_driverops,
3491 	"bridging driver",
3492 	&bridge_ops
3493 };
3494 
3495 static struct modlinkage modlinkage = {
3496 	MODREV_1,
3497 	(void *)&modldrv,
3498 	NULL
3499 };
3500 
3501 int
3502 _init(void)
3503 {
3504 	int retv;
3505 
3506 	mac_init_ops(NULL, BRIDGE_DEV_NAME);
3507 	bridge_inst_init();
3508 	if ((retv = mod_install(&modlinkage)) != 0)
3509 		bridge_inst_fini();
3510 	return (retv);
3511 }
3512 
3513 int
3514 _fini(void)
3515 {
3516 	int retv;
3517 
3518 	rw_enter(&bmac_rwlock, RW_READER);
3519 	retv = list_is_empty(&bmac_list) ? 0 : EBUSY;
3520 	rw_exit(&bmac_rwlock);
3521 	if (retv == 0 &&
3522 	    (retv = mod_remove(&modlinkage)) == 0)
3523 		bridge_inst_fini();
3524 	return (retv);
3525 }
3526 
3527 int
3528 _info(struct modinfo *modinfop)
3529 {
3530 	return (mod_info(&modlinkage, modinfop));
3531 }
3532