xref: /titanic_51/usr/src/uts/sun4v/io/vsw_switching.c (revision a563a037ee1e9e7c39304f3775eb7327ab86b914)
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 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/errno.h>
31 #include <sys/debug.h>
32 #include <sys/time.h>
33 #include <sys/sysmacros.h>
34 #include <sys/systm.h>
35 #include <sys/user.h>
36 #include <sys/stropts.h>
37 #include <sys/stream.h>
38 #include <sys/strlog.h>
39 #include <sys/strsubr.h>
40 #include <sys/cmn_err.h>
41 #include <sys/cpu.h>
42 #include <sys/kmem.h>
43 #include <sys/conf.h>
44 #include <sys/ddi.h>
45 #include <sys/sunddi.h>
46 #include <sys/ksynch.h>
47 #include <sys/stat.h>
48 #include <sys/kstat.h>
49 #include <sys/vtrace.h>
50 #include <sys/strsun.h>
51 #include <sys/dlpi.h>
52 #include <sys/ethernet.h>
53 #include <net/if.h>
54 #include <sys/varargs.h>
55 #include <sys/machsystm.h>
56 #include <sys/modctl.h>
57 #include <sys/modhash.h>
58 #include <sys/mac.h>
59 #include <sys/mac_ether.h>
60 #include <sys/taskq.h>
61 #include <sys/note.h>
62 #include <sys/mach_descrip.h>
63 #include <sys/mac.h>
64 #include <sys/mdeg.h>
65 #include <sys/ldc.h>
66 #include <sys/vsw_fdb.h>
67 #include <sys/vsw.h>
68 #include <sys/vio_mailbox.h>
69 #include <sys/vnet_mailbox.h>
70 #include <sys/vnet_common.h>
71 #include <sys/vio_util.h>
72 #include <sys/sdt.h>
73 #include <sys/atomic.h>
74 
75 /* Switching setup routines */
76 void vsw_setup_switching_timeout(void *arg);
77 void vsw_stop_switching_timeout(vsw_t *vswp);
78 int vsw_setup_switching(vsw_t *);
79 static	int vsw_setup_layer2(vsw_t *);
80 static	int vsw_setup_layer3(vsw_t *);
81 
82 /* Switching/data transmit routines */
83 static	void vsw_switch_l2_frame(vsw_t *vswp, mblk_t *mp, int caller,
84     vsw_port_t *port, mac_resource_handle_t);
85 static	void vsw_switch_l3_frame(vsw_t *vswp, mblk_t *mp, int caller,
86     vsw_port_t *port, mac_resource_handle_t);
87 static	int vsw_forward_all(vsw_t *vswp, mblk_t *mp,
88 	int caller, vsw_port_t *port);
89 static	int vsw_forward_grp(vsw_t *vswp, mblk_t *mp,
90     int caller, vsw_port_t *port);
91 
92 /* Forwarding database (FDB) routines */
93 static	vsw_port_t *vsw_lookup_fdb(vsw_t *vswp, struct ether_header *);
94 int vsw_add_rem_mcst(vnet_mcast_msg_t *, vsw_port_t *);
95 void vsw_del_mcst_port(vsw_port_t *);
96 int vsw_add_mcst(vsw_t *, uint8_t, uint64_t, void *);
97 int vsw_del_mcst(vsw_t *, uint8_t, uint64_t, void *);
98 void vsw_del_mcst_vsw(vsw_t *);
99 int vsw_add_fdb(vsw_t *vswp, vsw_port_t *port);
100 int vsw_del_fdb(vsw_t *vswp, vsw_port_t *port);
101 
102 /* Support functions */
103 static mblk_t *vsw_dupmsgchain(mblk_t *mp);
104 static uint32_t vsw_get_same_dest_list(struct ether_header *ehp,
105     mblk_t **rhead, mblk_t **rtail, mblk_t **mpp);
106 
107 
108 /*
109  * Functions imported from other files.
110  */
111 extern mblk_t *vsw_tx_msg(vsw_t *, mblk_t *);
112 extern mcst_addr_t *vsw_del_addr(uint8_t, void *, uint64_t);
113 extern int vsw_mac_open(vsw_t *vswp);
114 extern void vsw_mac_close(vsw_t *vswp);
115 extern void vsw_mac_rx(vsw_t *vswp, mac_resource_handle_t mrh,
116     mblk_t *mp, vsw_macrx_flags_t flags);
117 extern void vsw_set_addrs(vsw_t *vswp);
118 extern int vsw_get_hw_maddr(vsw_t *);
119 extern int vsw_mac_attach(vsw_t *vswp);
120 extern int vsw_portsend(vsw_port_t *port, mblk_t *mp, mblk_t *mpt,
121 	uint32_t count);
122 
123 /*
124  * Tunables used in this file.
125  */
126 extern int vsw_setup_switching_delay;
127 
128 
129 /*
130  * Timeout routine to setup switching mode:
131  * vsw_setup_switching() is invoked from vsw_attach() or vsw_update_md_prop()
132  * initially. If it fails and the error is EAGAIN, then this timeout handler
133  * is started to retry vsw_setup_switching(). vsw_setup_switching() is retried
134  * until we successfully finish it; or the returned error is not EAGAIN.
135  */
136 void
137 vsw_setup_switching_timeout(void *arg)
138 {
139 	vsw_t		*vswp = (vsw_t *)arg;
140 	int		rv;
141 
142 	if (vswp->swtmout_enabled == B_FALSE)
143 		return;
144 
145 	rv = vsw_setup_switching(vswp);
146 
147 	if (rv == 0) {
148 		/*
149 		 * Successfully setup switching mode.
150 		 * Program unicst, mcst addrs of vsw
151 		 * interface and ports in the physdev.
152 		 */
153 		vsw_set_addrs(vswp);
154 	}
155 
156 	mutex_enter(&vswp->swtmout_lock);
157 
158 	if (rv == EAGAIN && vswp->swtmout_enabled == B_TRUE) {
159 		/*
160 		 * Reschedule timeout() if the error is EAGAIN and the
161 		 * timeout is still enabled. For errors other than EAGAIN,
162 		 * we simply return without rescheduling timeout().
163 		 */
164 		vswp->swtmout_id =
165 		    timeout(vsw_setup_switching_timeout, vswp,
166 		    (vsw_setup_switching_delay * drv_usectohz(MICROSEC)));
167 		goto exit;
168 	}
169 
170 	/* timeout handler completed */
171 	vswp->swtmout_enabled = B_FALSE;
172 	vswp->swtmout_id = 0;
173 
174 exit:
175 	mutex_exit(&vswp->swtmout_lock);
176 }
177 
178 /*
179  * Cancel the timeout handler to setup switching mode.
180  */
181 void
182 vsw_stop_switching_timeout(vsw_t *vswp)
183 {
184 	timeout_id_t tid;
185 
186 	mutex_enter(&vswp->swtmout_lock);
187 
188 	tid = vswp->swtmout_id;
189 
190 	if (tid != 0) {
191 		/* signal timeout handler to stop */
192 		vswp->swtmout_enabled = B_FALSE;
193 		vswp->swtmout_id = 0;
194 		mutex_exit(&vswp->swtmout_lock);
195 
196 		(void) untimeout(tid);
197 	} else {
198 		mutex_exit(&vswp->swtmout_lock);
199 	}
200 
201 	(void) atomic_swap_32(&vswp->switching_setup_done, B_FALSE);
202 
203 	mutex_enter(&vswp->mac_lock);
204 	vswp->mac_open_retries = 0;
205 	mutex_exit(&vswp->mac_lock);
206 }
207 
208 /*
209  * Setup the required switching mode.
210  * This routine is invoked from vsw_attach() or vsw_update_md_prop()
211  * initially. If it fails and the error is EAGAIN, then a timeout handler
212  * is started to retry vsw_setup_switching(), until it successfully finishes;
213  * or the returned error is not EAGAIN.
214  *
215  * Returns:
216  *  0 on success.
217  *  EAGAIN if retry is needed.
218  *  1 on all other failures.
219  */
220 int
221 vsw_setup_switching(vsw_t *vswp)
222 {
223 	int	i, rv = 1;
224 
225 	D1(vswp, "%s: enter", __func__);
226 
227 	/*
228 	 * Select best switching mode.
229 	 * Note that we start from the saved smode_idx. This is done as
230 	 * this routine can be called from the timeout handler to retry
231 	 * setting up a specific mode. Currently only the function which
232 	 * sets up layer2/promisc mode returns EAGAIN if the underlying
233 	 * physical device is not available yet, causing retries.
234 	 */
235 	for (i = vswp->smode_idx; i < vswp->smode_num; i++) {
236 		vswp->smode_idx = i;
237 		switch (vswp->smode[i]) {
238 		case VSW_LAYER2:
239 		case VSW_LAYER2_PROMISC:
240 			rv = vsw_setup_layer2(vswp);
241 			break;
242 
243 		case VSW_LAYER3:
244 			rv = vsw_setup_layer3(vswp);
245 			break;
246 
247 		default:
248 			DERR(vswp, "unknown switch mode");
249 			break;
250 		}
251 
252 		if ((rv == 0) || (rv == EAGAIN))
253 			break;
254 
255 		/* all other errors(rv != 0): continue & select the next mode */
256 		rv = 1;
257 	}
258 
259 	if (rv && (rv != EAGAIN)) {
260 		cmn_err(CE_WARN, "!vsw%d: Unable to setup specified "
261 		    "switching mode", vswp->instance);
262 	} else if (rv == 0) {
263 		(void) atomic_swap_32(&vswp->switching_setup_done, B_TRUE);
264 	}
265 
266 	D2(vswp, "%s: Operating in mode %d", __func__,
267 	    vswp->smode[vswp->smode_idx]);
268 
269 	D1(vswp, "%s: exit", __func__);
270 
271 	return (rv);
272 }
273 
274 /*
275  * Setup for layer 2 switching.
276  *
277  * Returns:
278  *  0 on success.
279  *  EAGAIN if retry is needed.
280  *  EIO on all other failures.
281  */
282 static int
283 vsw_setup_layer2(vsw_t *vswp)
284 {
285 	int	rv;
286 
287 	D1(vswp, "%s: enter", __func__);
288 
289 	vswp->vsw_switch_frame = vsw_switch_l2_frame;
290 
291 	rv = strlen(vswp->physname);
292 	if (rv == 0) {
293 		/*
294 		 * Physical device name is NULL, which is
295 		 * required for layer 2.
296 		 */
297 		cmn_err(CE_WARN, "!vsw%d: no physical device name specified",
298 		    vswp->instance);
299 		return (EIO);
300 	}
301 
302 	mutex_enter(&vswp->mac_lock);
303 
304 	rv = vsw_mac_open(vswp);
305 	if (rv != 0) {
306 		if (rv != EAGAIN) {
307 			cmn_err(CE_WARN, "!vsw%d: Unable to open physical "
308 			    "device: %s\n", vswp->instance, vswp->physname);
309 		}
310 		mutex_exit(&vswp->mac_lock);
311 		return (rv);
312 	}
313 
314 	if (vswp->smode[vswp->smode_idx] == VSW_LAYER2) {
315 		/*
316 		 * Verify that underlying device can support multiple
317 		 * unicast mac addresses.
318 		 */
319 		rv = vsw_get_hw_maddr(vswp);
320 		if (rv != 0) {
321 			goto exit_error;
322 		}
323 	}
324 
325 	/*
326 	 * Attempt to link into the MAC layer so we can get
327 	 * and send packets out over the physical adapter.
328 	 */
329 	rv = vsw_mac_attach(vswp);
330 	if (rv != 0) {
331 		/*
332 		 * Registration with the MAC layer has failed,
333 		 * so return error so that can fall back to next
334 		 * prefered switching method.
335 		 */
336 		cmn_err(CE_WARN, "!vsw%d: Unable to setup physical device: "
337 		    "%s\n", vswp->instance, vswp->physname);
338 		goto exit_error;
339 	}
340 
341 	D1(vswp, "%s: exit", __func__);
342 
343 	mutex_exit(&vswp->mac_lock);
344 	return (0);
345 
346 exit_error:
347 	vsw_mac_close(vswp);
348 	mutex_exit(&vswp->mac_lock);
349 	return (EIO);
350 }
351 
352 static int
353 vsw_setup_layer3(vsw_t *vswp)
354 {
355 	D1(vswp, "%s: enter", __func__);
356 
357 	D2(vswp, "%s: operating in layer 3 mode", __func__);
358 	vswp->vsw_switch_frame = vsw_switch_l3_frame;
359 
360 	D1(vswp, "%s: exit", __func__);
361 
362 	return (0);
363 }
364 
365 /*
366  * Switch the given ethernet frame when operating in layer 2 mode.
367  *
368  * vswp: pointer to the vsw instance
369  * mp: pointer to chain of ethernet frame(s) to be switched
370  * caller: identifies the source of this frame as:
371  * 		1. VSW_VNETPORT - a vsw port (connected to a vnet).
372  *		2. VSW_PHYSDEV - the physical ethernet device
373  *		3. VSW_LOCALDEV - vsw configured as a virtual interface
374  * arg: argument provided by the caller.
375  *		1. for VNETPORT - pointer to the corresponding vsw_port_t.
376  *		2. for PHYSDEV - NULL
377  *		3. for LOCALDEV - pointer to to this vsw_t(self)
378  */
379 void
380 vsw_switch_l2_frame(vsw_t *vswp, mblk_t *mp, int caller,
381 			vsw_port_t *arg, mac_resource_handle_t mrh)
382 {
383 	struct ether_header	*ehp;
384 	vsw_port_t		*port = NULL;
385 	mblk_t			*bp, *ret_m;
386 	mblk_t			*mpt = NULL;
387 	uint32_t		count;
388 	vsw_port_list_t		*plist = &vswp->plist;
389 
390 	D1(vswp, "%s: enter (caller %d)", __func__, caller);
391 
392 	/*
393 	 * PERF: rather than breaking up the chain here, scan it
394 	 * to find all mblks heading to same destination and then
395 	 * pass that sub-chain to the lower transmit functions.
396 	 */
397 
398 	/* process the chain of packets */
399 	bp = mp;
400 	while (bp) {
401 		ehp = (struct ether_header *)bp->b_rptr;
402 		count = vsw_get_same_dest_list(ehp, &mp, &mpt, &bp);
403 		ASSERT(count != 0);
404 
405 		D2(vswp, "%s: mblk data buffer %lld : actual data size %lld",
406 		    __func__, MBLKSIZE(mp), MBLKL(mp));
407 
408 		if (ether_cmp(&ehp->ether_dhost, &vswp->if_addr) == 0) {
409 			/*
410 			 * If destination is VSW_LOCALDEV (vsw as an eth
411 			 * interface) and if the device is up & running,
412 			 * send the packet up the stack on this host.
413 			 * If the virtual interface is down, drop the packet.
414 			 */
415 			if (caller != VSW_LOCALDEV) {
416 				vsw_mac_rx(vswp, mrh, mp, VSW_MACRX_FREEMSG);
417 			} else {
418 				freemsgchain(mp);
419 			}
420 			continue;
421 		}
422 
423 		READ_ENTER(&plist->lockrw);
424 		port = vsw_lookup_fdb(vswp, ehp);
425 		if (port) {
426 			/*
427 			 * Mark the port as in-use before releasing the lockrw.
428 			 */
429 			VSW_PORT_REFHOLD(port);
430 			RW_EXIT(&plist->lockrw);
431 
432 			/*
433 			 * If plumbed and in promisc mode then copy msg
434 			 * and send up the stack.
435 			 */
436 			vsw_mac_rx(vswp, mrh, mp,
437 			    VSW_MACRX_PROMISC | VSW_MACRX_COPYMSG);
438 
439 			/*
440 			 * If the destination is in FDB, the packet
441 			 * should be forwarded to the correponding
442 			 * vsw_port (connected to a vnet device -
443 			 * VSW_VNETPORT)
444 			 */
445 			(void) vsw_portsend(port, mp, mpt, count);
446 
447 			/*
448 			 * Decrement use count in port.
449 			 */
450 			VSW_PORT_REFRELE(port);
451 		} else {
452 			RW_EXIT(&plist->lockrw);
453 			/*
454 			 * Destination not in FDB.
455 			 *
456 			 * If the destination is broadcast or
457 			 * multicast forward the packet to all
458 			 * (VNETPORTs, PHYSDEV, LOCALDEV),
459 			 * except the caller.
460 			 */
461 			if (IS_BROADCAST(ehp)) {
462 				D2(vswp, "%s: BROADCAST pkt", __func__);
463 				(void) vsw_forward_all(vswp, mp, caller, arg);
464 			} else if (IS_MULTICAST(ehp)) {
465 				D2(vswp, "%s: MULTICAST pkt", __func__);
466 				(void) vsw_forward_grp(vswp, mp, caller, arg);
467 			} else {
468 				/*
469 				 * If the destination is unicast, and came
470 				 * from either a logical network device or
471 				 * the switch itself when it is plumbed, then
472 				 * send it out on the physical device and also
473 				 * up the stack if the logical interface is
474 				 * in promiscious mode.
475 				 *
476 				 * NOTE:  The assumption here is that if we
477 				 * cannot find the destination in our fdb, its
478 				 * a unicast address, and came from either a
479 				 * vnet or down the stack (when plumbed) it
480 				 * must be destinded for an ethernet device
481 				 * outside our ldoms.
482 				 */
483 				if (caller == VSW_VNETPORT) {
484 					/* promisc check copy etc */
485 					vsw_mac_rx(vswp, mrh, mp,
486 					    VSW_MACRX_PROMISC |
487 					    VSW_MACRX_COPYMSG);
488 
489 					if ((ret_m = vsw_tx_msg(vswp, mp))
490 					    != NULL) {
491 						DERR(vswp, "%s: drop mblks to "
492 						    "phys dev", __func__);
493 						freemsgchain(ret_m);
494 					}
495 
496 				} else if (caller == VSW_PHYSDEV) {
497 					/*
498 					 * Pkt seen because card in promisc
499 					 * mode. Send up stack if plumbed in
500 					 * promisc mode, else drop it.
501 					 */
502 					vsw_mac_rx(vswp, mrh, mp,
503 					    VSW_MACRX_PROMISC |
504 					    VSW_MACRX_FREEMSG);
505 
506 				} else if (caller == VSW_LOCALDEV) {
507 					/*
508 					 * Pkt came down the stack, send out
509 					 * over physical device.
510 					 */
511 					if ((ret_m = vsw_tx_msg(vswp, mp))
512 					    != NULL) {
513 						DERR(vswp, "%s: drop mblks to "
514 						    "phys dev", __func__);
515 						freemsgchain(ret_m);
516 					}
517 				}
518 			}
519 		}
520 	}
521 	D1(vswp, "%s: exit\n", __func__);
522 }
523 
524 /*
525  * Switch ethernet frame when in layer 3 mode (i.e. using IP
526  * layer to do the routing).
527  *
528  * There is a large amount of overlap between this function and
529  * vsw_switch_l2_frame. At some stage we need to revisit and refactor
530  * both these functions.
531  */
532 void
533 vsw_switch_l3_frame(vsw_t *vswp, mblk_t *mp, int caller,
534 			vsw_port_t *arg, mac_resource_handle_t mrh)
535 {
536 	struct ether_header	*ehp;
537 	vsw_port_t		*port = NULL;
538 	mblk_t			*bp = NULL;
539 	mblk_t			*mpt;
540 	uint32_t		count;
541 	vsw_port_list_t		*plist = &vswp->plist;
542 
543 	D1(vswp, "%s: enter (caller %d)", __func__, caller);
544 
545 	/*
546 	 * In layer 3 mode should only ever be switching packets
547 	 * between IP layer and vnet devices. So make sure thats
548 	 * who is invoking us.
549 	 */
550 	if ((caller != VSW_LOCALDEV) && (caller != VSW_VNETPORT)) {
551 		DERR(vswp, "%s: unexpected caller (%d)", __func__, caller);
552 		freemsgchain(mp);
553 		return;
554 	}
555 
556 	/* process the chain of packets */
557 	bp = mp;
558 	while (bp) {
559 		ehp = (struct ether_header *)bp->b_rptr;
560 		count = vsw_get_same_dest_list(ehp, &mp, &mpt, &bp);
561 		ASSERT(count != 0);
562 
563 		D2(vswp, "%s: mblk data buffer %lld : actual data size %lld",
564 		    __func__, MBLKSIZE(mp), MBLKL(mp));
565 
566 		READ_ENTER(&plist->lockrw);
567 		port = vsw_lookup_fdb(vswp, ehp);
568 		if (port) {
569 			/*
570 			 * Mark the port as in-use before releasing the lockrw.
571 			 */
572 			VSW_PORT_REFHOLD(port);
573 			RW_EXIT(&plist->lockrw);
574 
575 			D2(vswp, "%s: sending to target port", __func__);
576 			(void) vsw_portsend(port, mp, mpt, count);
577 
578 			/*
579 			 * Decrement ref count.
580 			 */
581 			VSW_PORT_REFRELE(port);
582 		} else {
583 			RW_EXIT(&plist->lockrw);
584 			/*
585 			 * Destination not in FDB
586 			 *
587 			 * If the destination is broadcast or
588 			 * multicast forward the packet to all
589 			 * (VNETPORTs, PHYSDEV, LOCALDEV),
590 			 * except the caller.
591 			 */
592 			if (IS_BROADCAST(ehp)) {
593 				D2(vswp, "%s: BROADCAST pkt", __func__);
594 				(void) vsw_forward_all(vswp, mp, caller, arg);
595 			} else if (IS_MULTICAST(ehp)) {
596 				D2(vswp, "%s: MULTICAST pkt", __func__);
597 				(void) vsw_forward_grp(vswp, mp, caller, arg);
598 			} else {
599 				/*
600 				 * Unicast pkt from vnet that we don't have
601 				 * an FDB entry for, so must be destinded for
602 				 * the outside world. Attempt to send up to the
603 				 * IP layer to allow it to deal with it.
604 				 */
605 				if (caller == VSW_VNETPORT) {
606 					vsw_mac_rx(vswp, mrh,
607 					    mp, VSW_MACRX_FREEMSG);
608 				}
609 			}
610 		}
611 	}
612 
613 	D1(vswp, "%s: exit", __func__);
614 }
615 
616 /*
617  * Forward the ethernet frame to all ports (VNETPORTs, PHYSDEV, LOCALDEV),
618  * except the caller (port on which frame arrived).
619  */
620 static int
621 vsw_forward_all(vsw_t *vswp, mblk_t *mp, int caller, vsw_port_t *arg)
622 {
623 	vsw_port_list_t	*plist = &vswp->plist;
624 	vsw_port_t	*portp;
625 	mblk_t		*nmp = NULL;
626 	mblk_t		*ret_m = NULL;
627 	int		skip_port = 0;
628 
629 	D1(vswp, "vsw_forward_all: enter\n");
630 
631 	/*
632 	 * Broadcast message from inside ldoms so send to outside
633 	 * world if in either of layer 2 modes.
634 	 */
635 	if (((vswp->smode[vswp->smode_idx] == VSW_LAYER2) ||
636 	    (vswp->smode[vswp->smode_idx] == VSW_LAYER2_PROMISC)) &&
637 	    ((caller == VSW_LOCALDEV) || (caller == VSW_VNETPORT))) {
638 
639 		nmp = vsw_dupmsgchain(mp);
640 		if (nmp) {
641 			if ((ret_m = vsw_tx_msg(vswp, nmp)) != NULL) {
642 				DERR(vswp, "%s: dropping pkt(s) "
643 				    "consisting of %ld bytes of data for"
644 				    " physical device", __func__, MBLKL(ret_m));
645 				freemsgchain(ret_m);
646 			}
647 		}
648 	}
649 
650 	if (caller == VSW_VNETPORT)
651 		skip_port = 1;
652 
653 	/*
654 	 * Broadcast message from other vnet (layer 2 or 3) or outside
655 	 * world (layer 2 only), send up stack if plumbed.
656 	 */
657 	if ((caller == VSW_PHYSDEV) || (caller == VSW_VNETPORT)) {
658 		vsw_mac_rx(vswp, NULL, mp, VSW_MACRX_COPYMSG);
659 	}
660 
661 	/* send it to all VNETPORTs */
662 	READ_ENTER(&plist->lockrw);
663 	for (portp = plist->head; portp != NULL; portp = portp->p_next) {
664 		D2(vswp, "vsw_forward_all: port %d", portp->p_instance);
665 		/*
666 		 * Caution ! - don't reorder these two checks as arg
667 		 * will be NULL if the caller is PHYSDEV. skip_port is
668 		 * only set if caller is VNETPORT.
669 		 */
670 		if ((skip_port) && (portp == arg)) {
671 			continue;
672 		} else {
673 			nmp = vsw_dupmsgchain(mp);
674 			if (nmp) {
675 				mblk_t	*mpt = nmp;
676 				uint32_t count = 1;
677 
678 				/* Find tail */
679 				while (mpt->b_next != NULL) {
680 					mpt = mpt->b_next;
681 					count++;
682 				}
683 				/*
684 				 * The plist->lockrw is protecting the
685 				 * portp from getting destroyed here.
686 				 * So, no ref_cnt is incremented here.
687 				 */
688 				(void) vsw_portsend(portp, nmp, mpt, count);
689 			} else {
690 				DERR(vswp, "vsw_forward_all: nmp NULL");
691 			}
692 		}
693 	}
694 	RW_EXIT(&plist->lockrw);
695 
696 	freemsgchain(mp);
697 
698 	D1(vswp, "vsw_forward_all: exit\n");
699 	return (0);
700 }
701 
702 /*
703  * Forward pkts to any devices or interfaces which have registered
704  * an interest in them (i.e. multicast groups).
705  */
706 static int
707 vsw_forward_grp(vsw_t *vswp, mblk_t *mp, int caller, vsw_port_t *arg)
708 {
709 	struct ether_header	*ehp = (struct ether_header *)mp->b_rptr;
710 	mfdb_ent_t		*entp = NULL;
711 	mfdb_ent_t		*tpp = NULL;
712 	vsw_port_t 		*port;
713 	uint64_t		key = 0;
714 	mblk_t			*nmp = NULL;
715 	mblk_t			*ret_m = NULL;
716 	boolean_t		check_if = B_TRUE;
717 
718 	/*
719 	 * Convert address to hash table key
720 	 */
721 	KEY_HASH(key, ehp->ether_dhost);
722 
723 	D1(vswp, "%s: key 0x%llx", __func__, key);
724 
725 	/*
726 	 * If pkt came from either a vnet or down the stack (if we are
727 	 * plumbed) and we are in layer 2 mode, then we send the pkt out
728 	 * over the physical adapter, and then check to see if any other
729 	 * vnets are interested in it.
730 	 */
731 	if (((vswp->smode[vswp->smode_idx] == VSW_LAYER2) ||
732 	    (vswp->smode[vswp->smode_idx] == VSW_LAYER2_PROMISC)) &&
733 	    ((caller == VSW_VNETPORT) || (caller == VSW_LOCALDEV))) {
734 		nmp = vsw_dupmsgchain(mp);
735 		if (nmp) {
736 			if ((ret_m = vsw_tx_msg(vswp, nmp)) != NULL) {
737 				DERR(vswp, "%s: dropping pkt(s) consisting of "
738 				    "%ld bytes of data for physical device",
739 				    __func__, MBLKL(ret_m));
740 				freemsgchain(ret_m);
741 			}
742 		}
743 	}
744 
745 	READ_ENTER(&vswp->mfdbrw);
746 	if (mod_hash_find(vswp->mfdb, (mod_hash_key_t)key,
747 	    (mod_hash_val_t *)&entp) != 0) {
748 		D3(vswp, "%s: no table entry found for addr 0x%llx",
749 		    __func__, key);
750 	} else {
751 		/*
752 		 * Send to list of devices associated with this address...
753 		 */
754 		for (tpp = entp; tpp != NULL; tpp = tpp->nextp) {
755 
756 			/* dont send to ourselves */
757 			if ((caller == VSW_VNETPORT) &&
758 			    (tpp->d_addr == (void *)arg)) {
759 				port = (vsw_port_t *)tpp->d_addr;
760 				D3(vswp, "%s: not sending to ourselves"
761 				    " : port %d", __func__, port->p_instance);
762 				continue;
763 
764 			} else if ((caller == VSW_LOCALDEV) &&
765 			    (tpp->d_type == VSW_LOCALDEV)) {
766 				D2(vswp, "%s: not sending back up stack",
767 				    __func__);
768 				continue;
769 			}
770 
771 			if (tpp->d_type == VSW_VNETPORT) {
772 				port = (vsw_port_t *)tpp->d_addr;
773 				D3(vswp, "%s: sending to port %ld for addr "
774 				    "0x%llx", __func__, port->p_instance, key);
775 
776 				nmp = vsw_dupmsgchain(mp);
777 				if (nmp) {
778 					mblk_t	*mpt = nmp;
779 					uint32_t count = 1;
780 
781 					/* Find tail */
782 					while (mpt->b_next != NULL) {
783 						mpt = mpt->b_next;
784 						count++;
785 					}
786 					/*
787 					 * The vswp->mfdbrw is protecting the
788 					 * portp from getting destroyed here.
789 					 * So, no ref_cnt is incremented here.
790 					 */
791 					(void) vsw_portsend(port, nmp, mpt,
792 					    count);
793 				}
794 			} else {
795 				vsw_mac_rx(vswp, NULL,
796 				    mp, VSW_MACRX_COPYMSG);
797 				D2(vswp, "%s: sending up stack"
798 				    " for addr 0x%llx", __func__, key);
799 				check_if = B_FALSE;
800 			}
801 		}
802 	}
803 
804 	RW_EXIT(&vswp->mfdbrw);
805 
806 	/*
807 	 * If the pkt came from either a vnet or from physical device,
808 	 * and if we havent already sent the pkt up the stack then we
809 	 * check now if we can/should (i.e. the interface is plumbed
810 	 * and in promisc mode).
811 	 */
812 	if ((check_if) &&
813 	    ((caller == VSW_VNETPORT) || (caller == VSW_PHYSDEV))) {
814 		vsw_mac_rx(vswp, NULL, mp,
815 		    VSW_MACRX_PROMISC | VSW_MACRX_COPYMSG);
816 	}
817 
818 	freemsgchain(mp);
819 
820 	D1(vswp, "%s: exit", __func__);
821 
822 	return (0);
823 }
824 
825 /*
826  * Add an entry into FDB, for the given mac address and port_id.
827  * Returns 0 on success, 1 on failure.
828  *
829  * Lock protecting FDB must be held by calling process.
830  */
831 int
832 vsw_add_fdb(vsw_t *vswp, vsw_port_t *port)
833 {
834 	uint64_t	addr = 0;
835 
836 	D1(vswp, "%s: enter", __func__);
837 
838 	KEY_HASH(addr, port->p_macaddr);
839 
840 	D2(vswp, "%s: key = 0x%llx", __func__, addr);
841 
842 	/*
843 	 * Note: duplicate keys will be rejected by mod_hash.
844 	 */
845 	if (mod_hash_insert(vswp->fdb, (mod_hash_key_t)addr,
846 	    (mod_hash_val_t)port) != 0) {
847 		DERR(vswp, "%s: unable to add entry into fdb.", __func__);
848 		return (1);
849 	}
850 
851 	D1(vswp, "%s: exit", __func__);
852 	return (0);
853 }
854 
855 /*
856  * Remove an entry from FDB.
857  * Returns 0 on success, 1 on failure.
858  */
859 int
860 vsw_del_fdb(vsw_t *vswp, vsw_port_t *port)
861 {
862 	uint64_t	addr = 0;
863 
864 	D1(vswp, "%s: enter", __func__);
865 
866 	KEY_HASH(addr, port->p_macaddr);
867 
868 	D2(vswp, "%s: key = 0x%llx", __func__, addr);
869 
870 	(void) mod_hash_destroy(vswp->fdb, (mod_hash_val_t)addr);
871 
872 	D1(vswp, "%s: enter", __func__);
873 
874 	return (0);
875 }
876 
877 /*
878  * Search fdb for a given mac address.
879  * Returns pointer to the entry if found, else returns NULL.
880  */
881 static vsw_port_t *
882 vsw_lookup_fdb(vsw_t *vswp, struct ether_header *ehp)
883 {
884 	uint64_t	key = 0;
885 	vsw_port_t	*port = NULL;
886 
887 	D1(vswp, "%s: enter", __func__);
888 
889 	KEY_HASH(key, ehp->ether_dhost);
890 
891 	D2(vswp, "%s: key = 0x%llx", __func__, key);
892 
893 	if (mod_hash_find(vswp->fdb, (mod_hash_key_t)key,
894 	    (mod_hash_val_t *)&port) != 0) {
895 		D2(vswp, "%s: no port found", __func__);
896 		return (NULL);
897 	}
898 
899 	D1(vswp, "%s: exit", __func__);
900 
901 	return (port);
902 }
903 
904 /*
905  * Add or remove multicast address(es).
906  *
907  * Returns 0 on success, 1 on failure.
908  */
909 int
910 vsw_add_rem_mcst(vnet_mcast_msg_t *mcst_pkt, vsw_port_t *port)
911 {
912 	mcst_addr_t		*mcst_p = NULL;
913 	vsw_t			*vswp = port->p_vswp;
914 	uint64_t		addr = 0x0;
915 	int			i;
916 
917 	D1(vswp, "%s: enter", __func__);
918 
919 	D2(vswp, "%s: %d addresses", __func__, mcst_pkt->count);
920 
921 	for (i = 0; i < mcst_pkt->count; i++) {
922 		/*
923 		 * Convert address into form that can be used
924 		 * as hash table key.
925 		 */
926 		KEY_HASH(addr, mcst_pkt->mca[i]);
927 
928 		/*
929 		 * Add or delete the specified address/port combination.
930 		 */
931 		if (mcst_pkt->set == 0x1) {
932 			D3(vswp, "%s: adding multicast address 0x%llx for "
933 			    "port %ld", __func__, addr, port->p_instance);
934 			if (vsw_add_mcst(vswp, VSW_VNETPORT, addr, port) == 0) {
935 				/*
936 				 * Update the list of multicast
937 				 * addresses contained within the
938 				 * port structure to include this new
939 				 * one.
940 				 */
941 				mcst_p = kmem_zalloc(sizeof (mcst_addr_t),
942 				    KM_NOSLEEP);
943 				if (mcst_p == NULL) {
944 					DERR(vswp, "%s: unable to alloc mem",
945 					    __func__);
946 					(void) vsw_del_mcst(vswp,
947 					    VSW_VNETPORT, addr, port);
948 					return (1);
949 				}
950 
951 				mcst_p->nextp = NULL;
952 				mcst_p->addr = addr;
953 				ether_copy(&mcst_pkt->mca[i], &mcst_p->mca);
954 
955 				/*
956 				 * Program the address into HW. If the addr
957 				 * has already been programmed then the MAC
958 				 * just increments a ref counter (which is
959 				 * used when the address is being deleted)
960 				 */
961 				mutex_enter(&vswp->mac_lock);
962 				if (vswp->mh != NULL) {
963 					if (mac_multicst_add(vswp->mh,
964 					    (uchar_t *)&mcst_pkt->mca[i])) {
965 						mutex_exit(&vswp->mac_lock);
966 						cmn_err(CE_WARN, "!vsw%d: "
967 						    "unable to add multicast "
968 						    "address: %s\n",
969 						    vswp->instance,
970 						    ether_sprintf((void *)
971 						    &mcst_p->mca));
972 						(void) vsw_del_mcst(vswp,
973 						    VSW_VNETPORT, addr, port);
974 						kmem_free(mcst_p,
975 						    sizeof (*mcst_p));
976 						return (1);
977 					}
978 					mcst_p->mac_added = B_TRUE;
979 				}
980 				mutex_exit(&vswp->mac_lock);
981 
982 				mutex_enter(&port->mca_lock);
983 				mcst_p->nextp = port->mcap;
984 				port->mcap = mcst_p;
985 				mutex_exit(&port->mca_lock);
986 
987 			} else {
988 				DERR(vswp, "%s: error adding multicast "
989 				    "address 0x%llx for port %ld",
990 				    __func__, addr, port->p_instance);
991 				return (1);
992 			}
993 		} else {
994 			/*
995 			 * Delete an entry from the multicast hash
996 			 * table and update the address list
997 			 * appropriately.
998 			 */
999 			if (vsw_del_mcst(vswp, VSW_VNETPORT, addr, port) == 0) {
1000 				D3(vswp, "%s: deleting multicast address "
1001 				    "0x%llx for port %ld", __func__, addr,
1002 				    port->p_instance);
1003 
1004 				mcst_p = vsw_del_addr(VSW_VNETPORT, port, addr);
1005 				ASSERT(mcst_p != NULL);
1006 
1007 				/*
1008 				 * Remove the address from HW. The address
1009 				 * will actually only be removed once the ref
1010 				 * count within the MAC layer has dropped to
1011 				 * zero. I.e. we can safely call this fn even
1012 				 * if other ports are interested in this
1013 				 * address.
1014 				 */
1015 				mutex_enter(&vswp->mac_lock);
1016 				if (vswp->mh != NULL && mcst_p->mac_added) {
1017 					if (mac_multicst_remove(vswp->mh,
1018 					    (uchar_t *)&mcst_pkt->mca[i])) {
1019 						mutex_exit(&vswp->mac_lock);
1020 						cmn_err(CE_WARN, "!vsw%d: "
1021 						    "unable to remove mcast "
1022 						    "address: %s\n",
1023 						    vswp->instance,
1024 						    ether_sprintf((void *)
1025 						    &mcst_p->mca));
1026 						kmem_free(mcst_p,
1027 						    sizeof (*mcst_p));
1028 						return (1);
1029 					}
1030 					mcst_p->mac_added = B_FALSE;
1031 				}
1032 				mutex_exit(&vswp->mac_lock);
1033 				kmem_free(mcst_p, sizeof (*mcst_p));
1034 
1035 			} else {
1036 				DERR(vswp, "%s: error deleting multicast "
1037 				    "addr 0x%llx for port %ld",
1038 				    __func__, addr, port->p_instance);
1039 				return (1);
1040 			}
1041 		}
1042 	}
1043 	D1(vswp, "%s: exit", __func__);
1044 	return (0);
1045 }
1046 
1047 /*
1048  * Add a new multicast entry.
1049  *
1050  * Search hash table based on address. If match found then
1051  * update associated val (which is chain of ports), otherwise
1052  * create new key/val (addr/port) pair and insert into table.
1053  */
1054 int
1055 vsw_add_mcst(vsw_t *vswp, uint8_t devtype, uint64_t addr, void *arg)
1056 {
1057 	int		dup = 0;
1058 	int		rv = 0;
1059 	mfdb_ent_t	*ment = NULL;
1060 	mfdb_ent_t	*tmp_ent = NULL;
1061 	mfdb_ent_t	*new_ent = NULL;
1062 	void		*tgt = NULL;
1063 
1064 	if (devtype == VSW_VNETPORT) {
1065 		/*
1066 		 * Being invoked from a vnet.
1067 		 */
1068 		ASSERT(arg != NULL);
1069 		tgt = arg;
1070 		D2(NULL, "%s: port %d : address 0x%llx", __func__,
1071 		    ((vsw_port_t *)arg)->p_instance, addr);
1072 	} else {
1073 		/*
1074 		 * We are being invoked via the m_multicst mac entry
1075 		 * point.
1076 		 */
1077 		D2(NULL, "%s: address 0x%llx", __func__, addr);
1078 		tgt = (void *)vswp;
1079 	}
1080 
1081 	WRITE_ENTER(&vswp->mfdbrw);
1082 	if (mod_hash_find(vswp->mfdb, (mod_hash_key_t)addr,
1083 	    (mod_hash_val_t *)&ment) != 0) {
1084 
1085 		/* address not currently in table */
1086 		ment = kmem_alloc(sizeof (mfdb_ent_t), KM_SLEEP);
1087 		ment->d_addr = (void *)tgt;
1088 		ment->d_type = devtype;
1089 		ment->nextp = NULL;
1090 
1091 		if (mod_hash_insert(vswp->mfdb, (mod_hash_key_t)addr,
1092 		    (mod_hash_val_t)ment) != 0) {
1093 			DERR(vswp, "%s: hash table insertion failed", __func__);
1094 			kmem_free(ment, sizeof (mfdb_ent_t));
1095 			rv = 1;
1096 		} else {
1097 			D2(vswp, "%s: added initial entry for 0x%llx to "
1098 			    "table", __func__, addr);
1099 		}
1100 	} else {
1101 		/*
1102 		 * Address in table. Check to see if specified port
1103 		 * is already associated with the address. If not add
1104 		 * it now.
1105 		 */
1106 		tmp_ent = ment;
1107 		while (tmp_ent != NULL) {
1108 			if (tmp_ent->d_addr == (void *)tgt) {
1109 				if (devtype == VSW_VNETPORT) {
1110 					DERR(vswp, "%s: duplicate port entry "
1111 					    "found for portid %ld and key "
1112 					    "0x%llx", __func__,
1113 					    ((vsw_port_t *)arg)->p_instance,
1114 					    addr);
1115 				} else {
1116 					DERR(vswp, "%s: duplicate entry found"
1117 					    "for key 0x%llx", __func__, addr);
1118 				}
1119 				rv = 1;
1120 				dup = 1;
1121 				break;
1122 			}
1123 			tmp_ent = tmp_ent->nextp;
1124 		}
1125 
1126 		/*
1127 		 * Port not on list so add it to end now.
1128 		 */
1129 		if (0 == dup) {
1130 			D2(vswp, "%s: added entry for 0x%llx to table",
1131 			    __func__, addr);
1132 			new_ent = kmem_alloc(sizeof (mfdb_ent_t), KM_SLEEP);
1133 			new_ent->d_addr = (void *)tgt;
1134 			new_ent->d_type = devtype;
1135 			new_ent->nextp = NULL;
1136 
1137 			tmp_ent = ment;
1138 			while (tmp_ent->nextp != NULL)
1139 				tmp_ent = tmp_ent->nextp;
1140 
1141 			tmp_ent->nextp = new_ent;
1142 		}
1143 	}
1144 
1145 	RW_EXIT(&vswp->mfdbrw);
1146 	return (rv);
1147 }
1148 
1149 /*
1150  * Remove a multicast entry from the hashtable.
1151  *
1152  * Search hash table based on address. If match found, scan
1153  * list of ports associated with address. If specified port
1154  * found remove it from list.
1155  */
1156 int
1157 vsw_del_mcst(vsw_t *vswp, uint8_t devtype, uint64_t addr, void *arg)
1158 {
1159 	mfdb_ent_t	*ment = NULL;
1160 	mfdb_ent_t	*curr_p, *prev_p;
1161 	void		*tgt = NULL;
1162 
1163 	D1(vswp, "%s: enter", __func__);
1164 
1165 	if (devtype == VSW_VNETPORT) {
1166 		tgt = (vsw_port_t *)arg;
1167 		D2(vswp, "%s: removing port %d from mFDB for address"
1168 		    " 0x%llx", __func__, ((vsw_port_t *)tgt)->p_instance, addr);
1169 	} else {
1170 		D2(vswp, "%s: removing entry", __func__);
1171 		tgt = (void *)vswp;
1172 	}
1173 
1174 	WRITE_ENTER(&vswp->mfdbrw);
1175 	if (mod_hash_find(vswp->mfdb, (mod_hash_key_t)addr,
1176 	    (mod_hash_val_t *)&ment) != 0) {
1177 		D2(vswp, "%s: address 0x%llx not in table", __func__, addr);
1178 		RW_EXIT(&vswp->mfdbrw);
1179 		return (1);
1180 	}
1181 
1182 	prev_p = curr_p = ment;
1183 
1184 	while (curr_p != NULL) {
1185 		if (curr_p->d_addr == (void *)tgt) {
1186 			if (devtype == VSW_VNETPORT) {
1187 				D2(vswp, "%s: port %d found", __func__,
1188 				    ((vsw_port_t *)tgt)->p_instance);
1189 			} else {
1190 				D2(vswp, "%s: instance found", __func__);
1191 			}
1192 
1193 			if (prev_p == curr_p) {
1194 				/*
1195 				 * head of list, if no other element is in
1196 				 * list then destroy this entry, otherwise
1197 				 * just replace it with updated value.
1198 				 */
1199 				ment = curr_p->nextp;
1200 				if (ment == NULL) {
1201 					(void) mod_hash_destroy(vswp->mfdb,
1202 					    (mod_hash_val_t)addr);
1203 				} else {
1204 					(void) mod_hash_replace(vswp->mfdb,
1205 					    (mod_hash_key_t)addr,
1206 					    (mod_hash_val_t)ment);
1207 				}
1208 			} else {
1209 				/*
1210 				 * Not head of list, no need to do
1211 				 * replacement, just adjust list pointers.
1212 				 */
1213 				prev_p->nextp = curr_p->nextp;
1214 			}
1215 			break;
1216 		}
1217 
1218 		prev_p = curr_p;
1219 		curr_p = curr_p->nextp;
1220 	}
1221 
1222 	RW_EXIT(&vswp->mfdbrw);
1223 
1224 	D1(vswp, "%s: exit", __func__);
1225 
1226 	if (curr_p == NULL)
1227 		return (1);
1228 	kmem_free(curr_p, sizeof (mfdb_ent_t));
1229 	return (0);
1230 }
1231 
1232 /*
1233  * Port is being deleted, but has registered an interest in one
1234  * or more multicast groups. Using the list of addresses maintained
1235  * within the port structure find the appropriate entry in the hash
1236  * table and remove this port from the list of interested ports.
1237  */
1238 void
1239 vsw_del_mcst_port(vsw_port_t *port)
1240 {
1241 	mcst_addr_t	*mcap = NULL;
1242 	vsw_t		*vswp = port->p_vswp;
1243 
1244 	D1(vswp, "%s: enter", __func__);
1245 
1246 	mutex_enter(&port->mca_lock);
1247 
1248 	while ((mcap = port->mcap) != NULL) {
1249 
1250 		port->mcap = mcap->nextp;
1251 
1252 		mutex_exit(&port->mca_lock);
1253 
1254 		(void) vsw_del_mcst(vswp, VSW_VNETPORT,
1255 		    mcap->addr, port);
1256 
1257 		/*
1258 		 * Remove the address from HW. The address
1259 		 * will actually only be removed once the ref
1260 		 * count within the MAC layer has dropped to
1261 		 * zero. I.e. we can safely call this fn even
1262 		 * if other ports are interested in this
1263 		 * address.
1264 		 */
1265 		mutex_enter(&vswp->mac_lock);
1266 		if (vswp->mh != NULL && mcap->mac_added) {
1267 			(void) mac_multicst_remove(vswp->mh,
1268 			    (uchar_t *)&mcap->mca);
1269 		}
1270 		mutex_exit(&vswp->mac_lock);
1271 
1272 		kmem_free(mcap, sizeof (*mcap));
1273 
1274 		mutex_enter(&port->mca_lock);
1275 
1276 	}
1277 
1278 	mutex_exit(&port->mca_lock);
1279 
1280 	D1(vswp, "%s: exit", __func__);
1281 }
1282 
1283 /*
1284  * This vsw instance is detaching, but has registered an interest in one
1285  * or more multicast groups. Using the list of addresses maintained
1286  * within the vsw structure find the appropriate entry in the hash
1287  * table and remove this instance from the list of interested ports.
1288  */
1289 void
1290 vsw_del_mcst_vsw(vsw_t *vswp)
1291 {
1292 	mcst_addr_t	*next_p = NULL;
1293 
1294 	D1(vswp, "%s: enter", __func__);
1295 
1296 	mutex_enter(&vswp->mca_lock);
1297 
1298 	while (vswp->mcap != NULL) {
1299 		DERR(vswp, "%s: deleting addr 0x%llx",
1300 		    __func__, vswp->mcap->addr);
1301 		(void) vsw_del_mcst(vswp, VSW_LOCALDEV, vswp->mcap->addr, NULL);
1302 
1303 		next_p = vswp->mcap->nextp;
1304 		kmem_free(vswp->mcap, sizeof (mcst_addr_t));
1305 		vswp->mcap = next_p;
1306 	}
1307 
1308 	vswp->mcap = NULL;
1309 	mutex_exit(&vswp->mca_lock);
1310 
1311 	D1(vswp, "%s: exit", __func__);
1312 }
1313 
1314 static uint32_t
1315 vsw_get_same_dest_list(struct ether_header *ehp,
1316     mblk_t **rhead, mblk_t **rtail, mblk_t **mpp)
1317 {
1318 	uint32_t		count = 0;
1319 	mblk_t			*bp;
1320 	mblk_t			*nbp;
1321 	mblk_t			*head = NULL;
1322 	mblk_t			*tail = NULL;
1323 	mblk_t			*prev = NULL;
1324 	struct ether_header	*behp;
1325 
1326 	/* process the chain of packets */
1327 	bp = *mpp;
1328 	while (bp) {
1329 		nbp = bp->b_next;
1330 		behp = (struct ether_header *)bp->b_rptr;
1331 		bp->b_prev = NULL;
1332 		if (ether_cmp(&ehp->ether_dhost, &behp->ether_dhost) == 0) {
1333 			if (prev == NULL) {
1334 				*mpp = nbp;
1335 			} else {
1336 				prev->b_next = nbp;
1337 			}
1338 			bp->b_next =  NULL;
1339 			if (head == NULL) {
1340 				head = tail = bp;
1341 			} else {
1342 				tail->b_next = bp;
1343 				tail = bp;
1344 			}
1345 			count++;
1346 		} else {
1347 			prev = bp;
1348 		}
1349 		bp = nbp;
1350 	}
1351 	*rhead = head;
1352 	*rtail = tail;
1353 	DTRACE_PROBE1(vsw_same_dest, int, count);
1354 	return (count);
1355 }
1356 
1357 static mblk_t *
1358 vsw_dupmsgchain(mblk_t *mp)
1359 {
1360 	mblk_t	*nmp = NULL;
1361 	mblk_t	**nmpp = &nmp;
1362 
1363 	for (; mp != NULL; mp = mp->b_next) {
1364 		if ((*nmpp = dupmsg(mp)) == NULL) {
1365 			freemsgchain(nmp);
1366 			return (NULL);
1367 		}
1368 
1369 		nmpp = &((*nmpp)->b_next);
1370 	}
1371 
1372 	return (nmp);
1373 }
1374