xref: /titanic_50/usr/src/uts/common/io/mac/mac_bcast.c (revision bdb9230ac765cb7af3fc1f4119caf2c5720dceb3)
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  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/types.h>
27 #include <sys/sysmacros.h>
28 #include <sys/conf.h>
29 #include <sys/cmn_err.h>
30 #include <sys/list.h>
31 #include <sys/kmem.h>
32 #include <sys/stream.h>
33 #include <sys/modctl.h>
34 #include <sys/ddi.h>
35 #include <sys/sunddi.h>
36 #include <sys/atomic.h>
37 #include <sys/stat.h>
38 #include <sys/modhash.h>
39 #include <sys/strsubr.h>
40 #include <sys/strsun.h>
41 #include <sys/sdt.h>
42 #include <sys/mac.h>
43 #include <sys/mac_impl.h>
44 #include <sys/mac_client_impl.h>
45 #include <sys/mac_client_priv.h>
46 #include <sys/mac_flow_impl.h>
47 
48 /*
49  * Broadcast and multicast traffic must be distributed to the MAC clients
50  * that are defined on top of the same MAC. The set of
51  * destinations to which a multicast packet must be sent is a subset
52  * of all MAC clients defined on top of the MAC. A MAC client can be member
53  * of more than one such subset.
54  *
55  * To accomodate these requirements, we introduce broadcast groups.
56  * A broadcast group is associated with a broadcast or multicast
57  * address. The members of a broadcast group consist of the MAC clients
58  * that should received copies of packets sent to the address
59  * associated with the group, and are defined on top of the
60  * same MAC.
61  *
62  * The broadcast groups defined on top of a MAC are chained,
63  * hanging off the mac_impl_t. The broadcast group id's are
64  * unique globally (tracked by mac_bcast_id).
65  */
66 
67 /*
68  * The same MAC client may be added for different <addr,vid> tuple,
69  * we maintain a ref count for the number of times it has been added
70  * to account for deleting the MAC client from the group.
71  */
72 typedef struct mac_bcast_grp_mcip_s {
73 	mac_client_impl_t	*mgb_client;
74 	int			mgb_client_ref;
75 } mac_bcast_grp_mcip_t;
76 
77 typedef struct mac_bcast_grp_s {			/* Protected by */
78 	struct mac_bcast_grp_s	*mbg_next;		/* SL */
79 	void			*mbg_addr;		/* SL */
80 	uint16_t		mbg_vid;		/* SL */
81 	mac_impl_t		*mbg_mac_impl;		/* WO */
82 	mac_addrtype_t		mbg_addrtype;		/* WO */
83 	flow_entry_t		*mbg_flow_ent;		/* WO */
84 	mac_bcast_grp_mcip_t	*mbg_clients;		/* mi_rw_lock */
85 	uint_t			mbg_nclients;		/* mi_rw_lock */
86 	uint_t			mbg_nclients_alloc;	/* SL */
87 	uint64_t		mbg_clients_gen;	/* mi_rw_lock */
88 	uint32_t		mbg_id;			/* atomic */
89 } mac_bcast_grp_t;
90 
91 static kmem_cache_t *mac_bcast_grp_cache;
92 static uint32_t mac_bcast_id = 0;
93 
94 void
95 mac_bcast_init(void)
96 {
97 	mac_bcast_grp_cache = kmem_cache_create("mac_bcast_grp_cache",
98 	    sizeof (mac_bcast_grp_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
99 }
100 
101 void
102 mac_bcast_fini(void)
103 {
104 	kmem_cache_destroy(mac_bcast_grp_cache);
105 }
106 
107 mac_impl_t *
108 mac_bcast_grp_mip(void *grp)
109 {
110 	mac_bcast_grp_t *bcast_grp = grp;
111 
112 	return (bcast_grp->mbg_mac_impl);
113 }
114 
115 /*
116  * Free the specific broadcast group. Invoked when the last reference
117  * to the group is released.
118  */
119 void
120 mac_bcast_grp_free(void *bcast_grp)
121 {
122 	mac_bcast_grp_t	*grp = bcast_grp;
123 	mac_impl_t *mip = grp->mbg_mac_impl;
124 
125 	ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
126 
127 	ASSERT(grp->mbg_addr != NULL);
128 	kmem_free(grp->mbg_addr, mip->mi_type->mt_addr_length);
129 	kmem_free(grp->mbg_clients,
130 	    grp->mbg_nclients_alloc * sizeof (mac_bcast_grp_mcip_t));
131 	mip->mi_bcast_ngrps--;
132 	kmem_cache_free(mac_bcast_grp_cache, grp);
133 }
134 
135 /*
136  * arg1: broadcast group
137  * arg2: sender MAC client if it is being sent by a MAC client,
138  * NULL if it was received from the wire.
139  */
140 void
141 mac_bcast_send(void *arg1, void *arg2, mblk_t *mp_chain, boolean_t is_loopback)
142 {
143 	mac_bcast_grp_t *grp = arg1;
144 	mac_client_impl_t *src_mcip = arg2, *dst_mcip;
145 	mac_impl_t *mip = grp->mbg_mac_impl;
146 	uint64_t gen;
147 	uint_t i;
148 	mblk_t *mp_chain1;
149 	flow_entry_t	*flent;
150 	int err;
151 
152 	rw_enter(&mip->mi_rw_lock, RW_READER);
153 
154 	/*
155 	 * Pass a copy of the mp chain to every MAC client except the sender
156 	 * MAC client, if the packet was not received from the underlying NIC.
157 	 *
158 	 * The broadcast group lock should not be held across calls to
159 	 * the flow's callback function, since the same group could
160 	 * potentially be accessed from the same context. When the lock
161 	 * is reacquired, changes to the broadcast group while the lock
162 	 * was released are caught using a generation counter incremented
163 	 * each time the list of MAC clients associated with the broadcast
164 	 * group is changed.
165 	 */
166 	for (i = 0; i < grp->mbg_nclients_alloc; i++) {
167 		dst_mcip = grp->mbg_clients[i].mgb_client;
168 		if (dst_mcip == NULL)
169 			continue;
170 		flent = dst_mcip->mci_flent;
171 		if (flent == NULL || dst_mcip == src_mcip) {
172 			/*
173 			 * Don't send a copy of the packet back to
174 			 * its sender.
175 			 */
176 			continue;
177 		}
178 
179 		/*
180 		 * It is important to hold a reference on the
181 		 * flow_ent here.
182 		 */
183 		if ((mp_chain1 = mac_copymsgchain_cksum(mp_chain)) == NULL)
184 			break;
185 		/*
186 		 * Fix the checksum for packets originating
187 		 * from the local machine.
188 		 */
189 		if ((src_mcip != NULL) &&
190 		    (mp_chain1 = mac_fix_cksum(mp_chain1)) == NULL)
191 			break;
192 
193 		FLOW_TRY_REFHOLD(flent, err);
194 		if (err != 0) {
195 			freemsgchain(mp_chain1);
196 			continue;
197 		}
198 
199 		gen = grp->mbg_clients_gen;
200 
201 		rw_exit(&mip->mi_rw_lock);
202 
203 		DTRACE_PROBE4(mac__bcast__send__to, mac_client_impl_t *,
204 		    src_mcip, flow_fn_t, dst_mcip->mci_flent->fe_cb_fn,
205 		    void *, dst_mcip->mci_flent->fe_cb_arg1,
206 		    void *, dst_mcip->mci_flent->fe_cb_arg2);
207 
208 		(dst_mcip->mci_flent->fe_cb_fn)(dst_mcip->mci_flent->fe_cb_arg1,
209 		    dst_mcip->mci_flent->fe_cb_arg2, mp_chain1, is_loopback);
210 		FLOW_REFRELE(flent);
211 
212 		rw_enter(&mip->mi_rw_lock, RW_READER);
213 
214 		/* update stats */
215 		if (grp->mbg_addrtype == MAC_ADDRTYPE_MULTICAST)
216 			dst_mcip->mci_stat_multircv++;
217 		else
218 			dst_mcip->mci_stat_brdcstrcv++;
219 
220 		if (grp->mbg_clients_gen != gen) {
221 			/*
222 			 * The list of MAC clients associated with the group
223 			 * was changed while the lock was released.
224 			 * Give up on the current packet.
225 			 */
226 			rw_exit(&mip->mi_rw_lock);
227 			freemsgchain(mp_chain);
228 			return;
229 		}
230 	}
231 	rw_exit(&mip->mi_rw_lock);
232 
233 	if (src_mcip != NULL) {
234 		/*
235 		 * The packet was sent from one of the MAC clients,
236 		 * so we need to send a copy of the packet to the
237 		 * underlying NIC so that it can be sent on the wire.
238 		 */
239 		mblk_t *rest;
240 
241 		src_mcip->mci_stat_multixmt++;
242 		src_mcip->mci_stat_brdcstxmt++;
243 
244 		rest = MAC_RING_TX_DEFAULT(mip, mp_chain);
245 		if (rest != NULL)
246 			freemsgchain(rest);
247 	} else {
248 		freemsgchain(mp_chain);
249 	}
250 }
251 
252 /*
253  * Add the specified MAC client to the group corresponding to the specified
254  * broadcast or multicast address.
255  * Return 0 on success, or an errno value on failure.
256  */
257 int
258 mac_bcast_add(mac_client_impl_t *mcip, const uint8_t *addr, uint16_t vid,
259     mac_addrtype_t addrtype)
260 {
261 	mac_impl_t 		*mip = mcip->mci_mip;
262 	mac_bcast_grp_t		*grp = NULL, **last_grp;
263 	size_t			addr_len = mip->mi_type->mt_addr_length;
264 	int			rc = 0;
265 	int			i, index = -1;
266 	mac_mcast_addrs_t	**prev_mi_addr = NULL;
267 	mac_mcast_addrs_t	**prev_mci_addr = NULL;
268 
269 	ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
270 
271 	ASSERT(addrtype == MAC_ADDRTYPE_MULTICAST ||
272 	    addrtype == MAC_ADDRTYPE_BROADCAST);
273 
274 	/*
275 	 * Add the MAC client to the list of MAC clients associated
276 	 * with the group.
277 	 */
278 	if (addrtype == MAC_ADDRTYPE_MULTICAST) {
279 		mac_mcast_addrs_t	*maddr;
280 
281 		/*
282 		 * In case of a driver (say aggr), we need this information
283 		 * on a per MAC instance basis.
284 		 */
285 		prev_mi_addr = &mip->mi_mcast_addrs;
286 		for (maddr = *prev_mi_addr; maddr != NULL;
287 		    prev_mi_addr = &maddr->mma_next, maddr = maddr->mma_next) {
288 			if (bcmp(maddr->mma_addr, addr, addr_len) == 0)
289 				break;
290 		}
291 		if (maddr == NULL) {
292 			/*
293 			 * For multicast addresses, have the underlying MAC
294 			 * join the corresponding multicast group.
295 			 */
296 			rc = mip->mi_multicst(mip->mi_driver, B_TRUE, addr);
297 			if (rc != 0)
298 				return (rc);
299 			maddr = kmem_zalloc(sizeof (mac_mcast_addrs_t),
300 			    KM_SLEEP);
301 			bcopy(addr, maddr->mma_addr, addr_len);
302 			*prev_mi_addr = maddr;
303 		} else {
304 			prev_mi_addr = NULL;
305 		}
306 		maddr->mma_ref++;
307 
308 		/*
309 		 * We maintain a separate list for each MAC client. Get
310 		 * the entry or add, if it is not present.
311 		 */
312 		prev_mci_addr = &mcip->mci_mcast_addrs;
313 		for (maddr = *prev_mci_addr; maddr != NULL;
314 		    prev_mci_addr = &maddr->mma_next, maddr = maddr->mma_next) {
315 			if (bcmp(maddr->mma_addr, addr, addr_len) == 0)
316 				break;
317 		}
318 		if (maddr == NULL) {
319 			maddr = kmem_zalloc(sizeof (mac_mcast_addrs_t),
320 			    KM_SLEEP);
321 			bcopy(addr, maddr->mma_addr, addr_len);
322 			*prev_mci_addr = maddr;
323 		} else {
324 			prev_mci_addr = NULL;
325 		}
326 		maddr->mma_ref++;
327 	}
328 
329 	/* The list is protected by the perimeter */
330 	last_grp = &mip->mi_bcast_grp;
331 	for (grp = *last_grp; grp != NULL;
332 	    last_grp = &grp->mbg_next, grp = grp->mbg_next) {
333 		if (bcmp(grp->mbg_addr, addr, addr_len) == 0 &&
334 		    grp->mbg_vid == vid)
335 			break;
336 	}
337 
338 	if (grp == NULL) {
339 		/*
340 		 * The group does not yet exist, create it.
341 		 */
342 		flow_desc_t flow_desc;
343 		char flow_name[MAXFLOWNAMELEN];
344 
345 		grp = kmem_cache_alloc(mac_bcast_grp_cache, KM_SLEEP);
346 		bzero(grp, sizeof (mac_bcast_grp_t));
347 		grp->mbg_next = NULL;
348 		grp->mbg_mac_impl = mip;
349 
350 		DTRACE_PROBE1(mac__bcast__add__new__group, mac_bcast_grp_t *,
351 		    grp);
352 
353 		grp->mbg_addr = kmem_zalloc(addr_len, KM_SLEEP);
354 		bcopy(addr, grp->mbg_addr, addr_len);
355 		grp->mbg_addrtype = addrtype;
356 		grp->mbg_vid = vid;
357 
358 		/*
359 		 * Add a new flow to the underlying MAC.
360 		 */
361 		bzero(&flow_desc, sizeof (flow_desc));
362 		bcopy(addr, &flow_desc.fd_dst_mac, addr_len);
363 		flow_desc.fd_mac_len = (uint32_t)addr_len;
364 
365 		flow_desc.fd_mask = FLOW_LINK_DST;
366 		if (vid != 0) {
367 			flow_desc.fd_vid = vid;
368 			flow_desc.fd_mask |= FLOW_LINK_VID;
369 		}
370 
371 		grp->mbg_id = atomic_add_32_nv(&mac_bcast_id, 1);
372 		(void) sprintf(flow_name,
373 		    "mac/%s/mcast%d", mip->mi_name, grp->mbg_id);
374 
375 		rc = mac_flow_create(&flow_desc, NULL, flow_name,
376 		    grp, FLOW_MCAST, &grp->mbg_flow_ent);
377 		if (rc != 0) {
378 			kmem_free(grp->mbg_addr, addr_len);
379 			kmem_cache_free(mac_bcast_grp_cache, grp);
380 			goto fail;
381 		}
382 		grp->mbg_flow_ent->fe_mbg = grp;
383 		mip->mi_bcast_ngrps++;
384 
385 		/*
386 		 * Initial creation reference on the flow. This is released
387 		 * in the corresponding delete action i_mac_bcast_delete()
388 		 */
389 		FLOW_REFHOLD(grp->mbg_flow_ent);
390 
391 		/*
392 		 * When the multicast and broadcast packet is received
393 		 * by the underlying NIC, mac_rx_classify() will invoke
394 		 * mac_bcast_send() with arg2=NULL, which will cause
395 		 * mac_bcast_send() to send a copy of the packet(s)
396 		 * to every MAC client opened on top of the underlying MAC.
397 		 *
398 		 * When the mac_bcast_send() function is invoked from
399 		 * the transmit path of a MAC client, it will specify the
400 		 * transmitting MAC client as the arg2 value, which will
401 		 * allow mac_bcast_send() to skip that MAC client and not
402 		 * send it a copy of the packet.
403 		 *
404 		 * We program the classifier to dispatch matching broadcast
405 		 * packets to mac_bcast_send().
406 		 */
407 
408 		grp->mbg_flow_ent->fe_cb_fn = mac_bcast_send;
409 		grp->mbg_flow_ent->fe_cb_arg1 = grp;
410 		grp->mbg_flow_ent->fe_cb_arg2 = NULL;
411 
412 		rc = mac_flow_add(mip->mi_flow_tab, grp->mbg_flow_ent);
413 		if (rc != 0) {
414 			FLOW_FINAL_REFRELE(grp->mbg_flow_ent);
415 			goto fail;
416 		}
417 
418 		*last_grp = grp;
419 	}
420 
421 	ASSERT(grp->mbg_addrtype == addrtype);
422 
423 	/*
424 	 * Add the MAC client to the list of MAC clients associated
425 	 * with the group.
426 	 */
427 	rw_enter(&mip->mi_rw_lock, RW_WRITER);
428 	for (i = 0; i < grp->mbg_nclients_alloc; i++) {
429 		/*
430 		 * The MAC client was already added, say when we have
431 		 * different unicast addresses with the same vid.
432 		 * Just increment the ref and we are done.
433 		 */
434 		if (grp->mbg_clients[i].mgb_client == mcip) {
435 			grp->mbg_clients[i].mgb_client_ref++;
436 			rw_exit(&mip->mi_rw_lock);
437 			return (0);
438 		} else if (grp->mbg_clients[i].mgb_client == NULL &&
439 		    index == -1) {
440 			index = i;
441 		}
442 	}
443 	if (grp->mbg_nclients_alloc == grp->mbg_nclients) {
444 		mac_bcast_grp_mcip_t	*new_clients;
445 		uint_t			new_size = grp->mbg_nclients+1;
446 
447 		new_clients = kmem_zalloc(new_size *
448 		    sizeof (mac_bcast_grp_mcip_t), KM_SLEEP);
449 
450 		if (grp->mbg_nclients > 0) {
451 			ASSERT(grp->mbg_clients != NULL);
452 			bcopy(grp->mbg_clients, new_clients, grp->mbg_nclients *
453 			    sizeof (mac_bcast_grp_mcip_t));
454 			kmem_free(grp->mbg_clients, grp->mbg_nclients *
455 			    sizeof (mac_bcast_grp_mcip_t));
456 		}
457 
458 		grp->mbg_clients = new_clients;
459 		grp->mbg_nclients_alloc = new_size;
460 		index = new_size - 1;
461 	}
462 
463 	ASSERT(index != -1);
464 	grp->mbg_clients[index].mgb_client = mcip;
465 	grp->mbg_clients[index].mgb_client_ref = 1;
466 	grp->mbg_nclients++;
467 	/*
468 	 * Since we're adding to the list of MAC clients using that group,
469 	 * kick the generation count, which will allow mac_bcast_send()
470 	 * to detect that condition after re-acquiring the lock.
471 	 */
472 	grp->mbg_clients_gen++;
473 	rw_exit(&mip->mi_rw_lock);
474 	return (0);
475 
476 fail:
477 	if (prev_mi_addr != NULL) {
478 		kmem_free(*prev_mi_addr, sizeof (mac_mcast_addrs_t));
479 		*prev_mi_addr = NULL;
480 		(void) mip->mi_multicst(mip->mi_driver, B_FALSE, addr);
481 	}
482 	if (prev_mci_addr != NULL) {
483 		kmem_free(*prev_mci_addr, sizeof (mac_mcast_addrs_t));
484 		*prev_mci_addr = NULL;
485 	}
486 	return (rc);
487 }
488 
489 /*
490  * Remove the specified MAC client from the group corresponding to
491  * the specific broadcast or multicast address.
492  *
493  * Note: mac_bcast_delete() calls  mac_remove_flow() which
494  * will call cv_wait for fe_refcnt to drop to 0. So this function
495  * should not be called from interrupt or STREAMS context.
496  */
497 void
498 mac_bcast_delete(mac_client_impl_t *mcip, const uint8_t *addr, uint16_t vid)
499 {
500 	mac_impl_t *mip = mcip->mci_mip;
501 	mac_bcast_grp_t *grp = NULL, **prev;
502 	size_t addr_len = mip->mi_type->mt_addr_length;
503 	flow_entry_t *flent;
504 	uint_t i;
505 	mac_mcast_addrs_t	*maddr = NULL;
506 	mac_mcast_addrs_t	**mprev;
507 
508 	ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
509 
510 	/* find the broadcast group. The list is protected by the perimeter */
511 	prev = &mip->mi_bcast_grp;
512 	for (grp = mip->mi_bcast_grp; grp != NULL; prev = &grp->mbg_next,
513 	    grp = grp->mbg_next) {
514 		if (bcmp(grp->mbg_addr, addr, addr_len) == 0 &&
515 		    grp->mbg_vid == vid)
516 			break;
517 	}
518 	ASSERT(grp != NULL);
519 
520 	/*
521 	 * Remove the MAC client from the list of MAC clients associated
522 	 * with that broadcast group.
523 	 *
524 	 * We mark the mbg_clients[] location corresponding to the removed MAC
525 	 * client NULL and reuse that location when we add a new MAC client.
526 	 */
527 
528 	rw_enter(&mip->mi_rw_lock, RW_WRITER);
529 
530 	for (i = 0; i < grp->mbg_nclients_alloc; i++) {
531 		if (grp->mbg_clients[i].mgb_client == mcip)
532 			break;
533 	}
534 
535 	ASSERT(i < grp->mbg_nclients_alloc);
536 	/*
537 	 * If there are more references to this MAC client, then we let
538 	 * it remain till it goes to 0.
539 	 */
540 	if (--grp->mbg_clients[i].mgb_client_ref > 0)
541 		goto update_maddr;
542 
543 	grp->mbg_clients[i].mgb_client = NULL;
544 	grp->mbg_clients[i].mgb_client_ref = 0;
545 
546 	/*
547 	 * Since we're removing from the list of MAC clients using that group,
548 	 * kick the generation count, which will allow mac_bcast_send()
549 	 * to detect that condition.
550 	 */
551 	grp->mbg_clients_gen++;
552 
553 	if (--grp->mbg_nclients == 0) {
554 		/*
555 		 * The last MAC client of the group was just removed.
556 		 * Unlink the current group from the list of groups
557 		 * defined on top of the underlying NIC. The group
558 		 * structure will stay around until the last reference
559 		 * is dropped.
560 		 */
561 		*prev = grp->mbg_next;
562 	}
563 update_maddr:
564 	rw_exit(&mip->mi_rw_lock);
565 
566 	if (grp->mbg_addrtype == MAC_ADDRTYPE_MULTICAST) {
567 		mprev = &mcip->mci_mcast_addrs;
568 		for (maddr = mcip->mci_mcast_addrs; maddr != NULL;
569 		    mprev = &maddr->mma_next, maddr = maddr->mma_next) {
570 			if (bcmp(grp->mbg_addr, maddr->mma_addr,
571 			    mip->mi_type->mt_addr_length) == 0)
572 				break;
573 		}
574 		ASSERT(maddr != NULL);
575 		if (--maddr->mma_ref == 0) {
576 			*mprev = maddr->mma_next;
577 			maddr->mma_next = NULL;
578 			kmem_free(maddr, sizeof (mac_mcast_addrs_t));
579 		}
580 
581 		mprev = &mip->mi_mcast_addrs;
582 		for (maddr = mip->mi_mcast_addrs; maddr != NULL;
583 		    mprev = &maddr->mma_next, maddr = maddr->mma_next) {
584 			if (bcmp(grp->mbg_addr, maddr->mma_addr,
585 			    mip->mi_type->mt_addr_length) == 0)
586 				break;
587 		}
588 		ASSERT(maddr != NULL);
589 		if (--maddr->mma_ref == 0) {
590 			(void) mip->mi_multicst(mip->mi_driver, B_FALSE, addr);
591 			*mprev = maddr->mma_next;
592 			maddr->mma_next = NULL;
593 			kmem_free(maddr, sizeof (mac_mcast_addrs_t));
594 		}
595 	}
596 
597 	/*
598 	 * If the group itself is being removed, remove the
599 	 * corresponding flow from the underlying NIC.
600 	 */
601 	flent = grp->mbg_flow_ent;
602 	if (grp->mbg_nclients == 0) {
603 		mac_flow_remove(mip->mi_flow_tab, flent, B_FALSE);
604 		mac_flow_wait(flent, FLOW_DRIVER_UPCALL);
605 		FLOW_FINAL_REFRELE(flent);
606 	}
607 }
608 
609 /*
610  * This will be called by a driver, such as aggr, when a port is added/removed
611  * to add/remove the port to/from all the multcast addresses for that aggr.
612  */
613 void
614 mac_bcast_refresh(mac_impl_t *mip, mac_multicst_t refresh_fn, void *arg,
615     boolean_t add)
616 {
617 	mac_mcast_addrs_t *grp, *next;
618 
619 	ASSERT(refresh_fn != NULL);
620 
621 	ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
622 
623 	/*
624 	 * Walk the multicast address list and call the refresh function for
625 	 * each address.
626 	 */
627 
628 	for (grp = mip->mi_mcast_addrs; grp != NULL; grp = next) {
629 		/*
630 		 * Save the next pointer just in case the refresh
631 		 * function's action causes the group entry to be
632 		 * freed.
633 		 * We won't be adding to this list as part of the
634 		 * refresh.
635 		 */
636 		next = grp->mma_next;
637 		refresh_fn(arg, add, grp->mma_addr);
638 	}
639 }
640 
641 /*
642  * Walk the MAC client's multicast address list and add/remove the addr/vid
643  * ('arg' is 'flent') to all the addresses.
644  */
645 void
646 mac_client_bcast_refresh(mac_client_impl_t *mcip, mac_multicst_t refresh_fn,
647     void *arg, boolean_t add)
648 {
649 	mac_mcast_addrs_t *grp, *next;
650 	mac_impl_t		*mip = mcip->mci_mip;
651 
652 	ASSERT(refresh_fn != NULL);
653 
654 	ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
655 	/*
656 	 * Walk the multicast address list and call the refresh function for
657 	 * each address.
658 	 * Broadcast addresses are not added or removed through the multicast
659 	 * entry points, so don't include them as part of the refresh.
660 	 */
661 	for (grp = mcip->mci_mcast_addrs; grp != NULL; grp = next) {
662 		/*
663 		 * Save the next pointer just in case the refresh
664 		 * function's action causes the group entry to be
665 		 * freed.
666 		 * We won't be adding to this list as part of the
667 		 * refresh.
668 		 */
669 		next = grp->mma_next;
670 		refresh_fn(arg, add, grp->mma_addr);
671 	}
672 }
673