xref: /netbsd-src/sys/net/if_vlan.c (revision aa73cae19608873cc4d1f712c4a0f8f8435f1ffa)
1 /*	$NetBSD: if_vlan.c,v 1.44 2005/02/26 22:45:09 perry Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran, and by Jason R. Thorpe of Zembu Labs, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright 1998 Massachusetts Institute of Technology
41  *
42  * Permission to use, copy, modify, and distribute this software and
43  * its documentation for any purpose and without fee is hereby
44  * granted, provided that both the above copyright notice and this
45  * permission notice appear in all copies, that both the above
46  * copyright notice and this permission notice appear in all
47  * supporting documentation, and that the name of M.I.T. not be used
48  * in advertising or publicity pertaining to distribution of the
49  * software without specific, written prior permission.  M.I.T. makes
50  * no representations about the suitability of this software for any
51  * purpose.  It is provided "as is" without express or implied
52  * warranty.
53  *
54  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
55  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
56  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
57  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
58  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
59  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
60  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
61  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
62  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
63  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
64  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  * from FreeBSD: if_vlan.c,v 1.16 2000/03/26 15:21:40 charnier Exp
68  * via OpenBSD: if_vlan.c,v 1.4 2000/05/15 19:15:00 chris Exp
69  */
70 
71 /*
72  * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.  Might be
73  * extended some day to also handle IEEE 802.1P priority tagging.  This is
74  * sort of sneaky in the implementation, since we need to pretend to be
75  * enough of an Ethernet implementation to make ARP work.  The way we do
76  * this is by telling everyone that we are an Ethernet interface, and then
77  * catch the packets that ether_output() left on our output queue when it
78  * calls if_start(), rewrite them for use by the real outgoing interface,
79  * and ask it to send them.
80  *
81  * TODO:
82  *
83  *	- Need some way to notify vlan interfaces when the parent
84  *	  interface changes MTU.
85  */
86 
87 #include <sys/cdefs.h>
88 __KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.44 2005/02/26 22:45:09 perry Exp $");
89 
90 #include "opt_inet.h"
91 #include "bpfilter.h"
92 
93 #include <sys/param.h>
94 #include <sys/kernel.h>
95 #include <sys/mbuf.h>
96 #include <sys/queue.h>
97 #include <sys/socket.h>
98 #include <sys/sockio.h>
99 #include <sys/systm.h>
100 #include <sys/proc.h>
101 
102 #if NBPFILTER > 0
103 #include <net/bpf.h>
104 #endif
105 #include <net/if.h>
106 #include <net/if_dl.h>
107 #include <net/if_types.h>
108 #include <net/if_ether.h>
109 #include <net/if_vlanvar.h>
110 
111 #ifdef INET
112 #include <netinet/in.h>
113 #include <netinet/if_inarp.h>
114 #endif
115 
116 struct vlan_mc_entry {
117 	LIST_ENTRY(vlan_mc_entry)	mc_entries;
118 	/*
119 	 * A key to identify this entry.  The mc_addr below can't be
120 	 * used since multiple sockaddr may mapped into the same
121 	 * ether_multi (e.g., AF_UNSPEC).
122 	 */
123 	union {
124 		struct ether_multi	*mcu_enm;
125 	} mc_u;
126 	struct sockaddr_storage		mc_addr;
127 };
128 
129 #define	mc_enm		mc_u.mcu_enm
130 
131 struct ifvlan {
132 	union {
133 		struct ethercom ifvu_ec;
134 	} ifv_u;
135 	struct ifnet *ifv_p;	/* parent interface of this vlan */
136 	struct ifv_linkmib {
137 		const struct vlan_multisw *ifvm_msw;
138 		int	ifvm_encaplen;	/* encapsulation length */
139 		int	ifvm_mtufudge;	/* MTU fudged by this much */
140 		int	ifvm_mintu;	/* min transmission unit */
141 		u_int16_t ifvm_proto;	/* encapsulation ethertype */
142 		u_int16_t ifvm_tag;	/* tag to apply on packets */
143 	} ifv_mib;
144 	LIST_HEAD(__vlan_mchead, vlan_mc_entry) ifv_mc_listhead;
145 	LIST_ENTRY(ifvlan) ifv_list;
146 	int ifv_flags;
147 };
148 
149 #define	IFVF_PROMISC	0x01		/* promiscuous mode enabled */
150 
151 #define	ifv_ec		ifv_u.ifvu_ec
152 
153 #define	ifv_if		ifv_ec.ec_if
154 
155 #define	ifv_msw		ifv_mib.ifvm_msw
156 #define	ifv_encaplen	ifv_mib.ifvm_encaplen
157 #define	ifv_mtufudge	ifv_mib.ifvm_mtufudge
158 #define	ifv_mintu	ifv_mib.ifvm_mintu
159 #define	ifv_tag		ifv_mib.ifvm_tag
160 
161 struct vlan_multisw {
162 	int	(*vmsw_addmulti)(struct ifvlan *, struct ifreq *);
163 	int	(*vmsw_delmulti)(struct ifvlan *, struct ifreq *);
164 	void	(*vmsw_purgemulti)(struct ifvlan *);
165 };
166 
167 static int	vlan_ether_addmulti(struct ifvlan *, struct ifreq *);
168 static int	vlan_ether_delmulti(struct ifvlan *, struct ifreq *);
169 static void	vlan_ether_purgemulti(struct ifvlan *);
170 
171 const struct vlan_multisw vlan_ether_multisw = {
172 	vlan_ether_addmulti,
173 	vlan_ether_delmulti,
174 	vlan_ether_purgemulti,
175 };
176 
177 static int	vlan_clone_create(struct if_clone *, int);
178 static int	vlan_clone_destroy(struct ifnet *);
179 static int	vlan_config(struct ifvlan *, struct ifnet *);
180 static int	vlan_ioctl(struct ifnet *, u_long, caddr_t);
181 static void	vlan_start(struct ifnet *);
182 static void	vlan_unconfig(struct ifnet *);
183 
184 void		vlanattach(int);
185 
186 /* XXX This should be a hash table with the tag as the basis of the key. */
187 static LIST_HEAD(, ifvlan) ifv_list;
188 
189 struct if_clone vlan_cloner =
190     IF_CLONE_INITIALIZER("vlan", vlan_clone_create, vlan_clone_destroy);
191 
192 /* Used to pad ethernet frames with < ETHER_MIN_LEN bytes */
193 static char vlan_zero_pad_buff[ETHER_MIN_LEN];
194 
195 void
196 vlanattach(int n)
197 {
198 
199 	LIST_INIT(&ifv_list);
200 	if_clone_attach(&vlan_cloner);
201 }
202 
203 static void
204 vlan_reset_linkname(struct ifnet *ifp)
205 {
206 
207 	/*
208 	 * We start out with a "802.1Q VLAN" type and zero-length
209 	 * addresses.  When we attach to a parent interface, we
210 	 * inherit its type, address length, address, and data link
211 	 * type.
212 	 */
213 
214 	ifp->if_type = IFT_L2VLAN;
215 	ifp->if_addrlen = 0;
216 	ifp->if_dlt = DLT_NULL;
217 	if_alloc_sadl(ifp);
218 }
219 
220 static int
221 vlan_clone_create(struct if_clone *ifc, int unit)
222 {
223 	struct ifvlan *ifv;
224 	struct ifnet *ifp;
225 	int s;
226 
227 	ifv = malloc(sizeof(struct ifvlan), M_DEVBUF, M_WAITOK);
228 	memset(ifv, 0, sizeof(struct ifvlan));
229 	ifp = &ifv->ifv_if;
230 	LIST_INIT(&ifv->ifv_mc_listhead);
231 
232 	s = splnet();
233 	LIST_INSERT_HEAD(&ifv_list, ifv, ifv_list);
234 	splx(s);
235 
236 	snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d", ifc->ifc_name,
237 	    unit);
238 	ifp->if_softc = ifv;
239 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
240 	ifp->if_start = vlan_start;
241 	ifp->if_ioctl = vlan_ioctl;
242 	IFQ_SET_READY(&ifp->if_snd);
243 
244 	if_attach(ifp);
245 	vlan_reset_linkname(ifp);
246 
247 	return (0);
248 }
249 
250 static int
251 vlan_clone_destroy(struct ifnet *ifp)
252 {
253 	struct ifvlan *ifv = ifp->if_softc;
254 	int s;
255 
256 	s = splnet();
257 	LIST_REMOVE(ifv, ifv_list);
258 	vlan_unconfig(ifp);
259 	splx(s);
260 
261 	if_detach(ifp);
262 	free(ifv, M_DEVBUF);
263 
264 	return (0);
265 }
266 
267 /*
268  * Configure a VLAN interface.  Must be called at splnet().
269  */
270 static int
271 vlan_config(struct ifvlan *ifv, struct ifnet *p)
272 {
273 	struct ifnet *ifp = &ifv->ifv_if;
274 	int error;
275 
276 	if (ifv->ifv_p != NULL)
277 		return (EBUSY);
278 
279 	switch (p->if_type) {
280 	case IFT_ETHER:
281 	    {
282 		struct ethercom *ec = (void *) p;
283 
284 		ifv->ifv_msw = &vlan_ether_multisw;
285 		ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN;
286 		ifv->ifv_mintu = ETHERMIN;
287 
288 		/*
289 		 * If the parent supports the VLAN_MTU capability,
290 		 * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames,
291 		 * enable it.
292 		 */
293 		if (ec->ec_nvlans++ == 0 &&
294 		    (ec->ec_capabilities & ETHERCAP_VLAN_MTU) != 0) {
295 			/*
296 			 * Enable Tx/Rx of VLAN-sized frames.
297 			 */
298 			ec->ec_capenable |= ETHERCAP_VLAN_MTU;
299 			if (p->if_flags & IFF_UP) {
300 				struct ifreq ifr;
301 
302 				ifr.ifr_flags = p->if_flags;
303 				error = (*p->if_ioctl)(p, SIOCSIFFLAGS,
304 				    (caddr_t) &ifr);
305 				if (error) {
306 					if (ec->ec_nvlans-- == 1)
307 						ec->ec_capenable &=
308 						    ~ETHERCAP_VLAN_MTU;
309 					return (error);
310 				}
311 			}
312 			ifv->ifv_mtufudge = 0;
313 		} else if ((ec->ec_capabilities & ETHERCAP_VLAN_MTU) == 0) {
314 			/*
315 			 * Fudge the MTU by the encapsulation size.  This
316 			 * makes us incompatible with strictly compliant
317 			 * 802.1Q implementations, but allows us to use
318 			 * the feature with other NetBSD implementations,
319 			 * which might still be useful.
320 			 */
321 			ifv->ifv_mtufudge = ifv->ifv_encaplen;
322 		}
323 
324 		/*
325 		 * If the parent interface can do hardware-assisted
326 		 * VLAN encapsulation, then propagate its hardware-
327 		 * assisted checksumming flags.
328 		 */
329 		if (ec->ec_capabilities & ETHERCAP_VLAN_HWTAGGING)
330 			ifp->if_capabilities = p->if_capabilities &
331 			    (IFCAP_CSUM_IPv4|IFCAP_CSUM_TCPv4|
332 			     IFCAP_CSUM_UDPv4|IFCAP_CSUM_TCPv6|
333 			     IFCAP_CSUM_UDPv6);
334 
335 		/*
336 		 * We inherit the parent's Ethernet address.
337 		 */
338 		ether_ifattach(ifp, LLADDR(p->if_sadl));
339 		ifp->if_hdrlen = sizeof(struct ether_vlan_header); /* XXX? */
340 		break;
341 	    }
342 
343 	default:
344 		return (EPROTONOSUPPORT);
345 	}
346 
347 	ifv->ifv_p = p;
348 	ifv->ifv_if.if_mtu = p->if_mtu - ifv->ifv_mtufudge;
349 	ifv->ifv_if.if_flags = p->if_flags &
350 	    (IFF_UP | IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
351 
352 	/*
353 	 * Inherit the if_type from the parent.  This allows us
354 	 * to participate in bridges of that type.
355 	 */
356 	ifv->ifv_if.if_type = p->if_type;
357 
358 	return (0);
359 }
360 
361 /*
362  * Unconfigure a VLAN interface.  Must be called at splnet().
363  */
364 static void
365 vlan_unconfig(struct ifnet *ifp)
366 {
367 	struct ifvlan *ifv = ifp->if_softc;
368 
369 	if (ifv->ifv_p == NULL)
370 		return;
371 
372 	/*
373  	 * Since the interface is being unconfigured, we need to empty the
374 	 * list of multicast groups that we may have joined while we were
375 	 * alive and remove them from the parent's list also.
376 	 */
377 	(*ifv->ifv_msw->vmsw_purgemulti)(ifv);
378 
379 	/* Disconnect from parent. */
380 	switch (ifv->ifv_p->if_type) {
381 	case IFT_ETHER:
382 	    {
383 		struct ethercom *ec = (void *) ifv->ifv_p;
384 
385 		if (ec->ec_nvlans-- == 1) {
386 			/*
387 			 * Disable Tx/Rx of VLAN-sized frames.
388 			 */
389 			ec->ec_capenable &= ~ETHERCAP_VLAN_MTU;
390 			if (ifv->ifv_p->if_flags & IFF_UP) {
391 				struct ifreq ifr;
392 
393 				ifr.ifr_flags = ifv->ifv_p->if_flags;
394 				(void) (*ifv->ifv_p->if_ioctl)(ifv->ifv_p,
395 				    SIOCSIFFLAGS, (caddr_t) &ifr);
396 			}
397 		}
398 
399 		ether_ifdetach(ifp);
400 		vlan_reset_linkname(ifp);
401 		break;
402 	    }
403 
404 #ifdef DIAGNOSTIC
405 	default:
406 		panic("vlan_unconfig: impossible");
407 #endif
408 	}
409 
410 	ifv->ifv_p = NULL;
411 	ifv->ifv_if.if_mtu = 0;
412 	ifv->ifv_flags = 0;
413 
414 	if_down(ifp);
415 	ifp->if_flags &= ~(IFF_UP|IFF_RUNNING);
416 	ifp->if_capabilities = 0;
417 }
418 
419 /*
420  * Called when a parent interface is detaching; destroy any VLAN
421  * configuration for the parent interface.
422  */
423 void
424 vlan_ifdetach(struct ifnet *p)
425 {
426 	struct ifvlan *ifv;
427 	int s;
428 
429 	s = splnet();
430 
431 	for (ifv = LIST_FIRST(&ifv_list); ifv != NULL;
432 	     ifv = LIST_NEXT(ifv, ifv_list)) {
433 		if (ifv->ifv_p == p)
434 			vlan_unconfig(&ifv->ifv_if);
435 	}
436 
437 	splx(s);
438 }
439 
440 static int
441 vlan_set_promisc(struct ifnet *ifp)
442 {
443 	struct ifvlan *ifv = ifp->if_softc;
444 	int error = 0;
445 
446 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
447 		if ((ifv->ifv_flags & IFVF_PROMISC) == 0) {
448 			error = ifpromisc(ifv->ifv_p, 1);
449 			if (error == 0)
450 				ifv->ifv_flags |= IFVF_PROMISC;
451 		}
452 	} else {
453 		if ((ifv->ifv_flags & IFVF_PROMISC) != 0) {
454 			error = ifpromisc(ifv->ifv_p, 0);
455 			if (error == 0)
456 				ifv->ifv_flags &= ~IFVF_PROMISC;
457 		}
458 	}
459 
460 	return (error);
461 }
462 
463 static int
464 vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
465 {
466 	struct proc *p = curproc;	/* XXX */
467 	struct ifvlan *ifv = ifp->if_softc;
468 	struct ifaddr *ifa = (struct ifaddr *) data;
469 	struct ifreq *ifr = (struct ifreq *) data;
470 	struct ifnet *pr;
471 	struct vlanreq vlr;
472 	struct sockaddr *sa;
473 	int s, error = 0;
474 
475 	s = splnet();
476 
477 	switch (cmd) {
478 	case SIOCSIFADDR:
479 		if (ifv->ifv_p != NULL) {
480 			ifp->if_flags |= IFF_UP;
481 
482 			switch (ifa->ifa_addr->sa_family) {
483 #ifdef INET
484 			case AF_INET:
485 				arp_ifinit(ifp, ifa);
486 				break;
487 #endif
488 			default:
489 				break;
490 			}
491 		} else {
492 			error = EINVAL;
493 		}
494 		break;
495 
496 	case SIOCGIFADDR:
497 		sa = (struct sockaddr *)&ifr->ifr_data;
498 		memcpy(sa->sa_data, LLADDR(ifp->if_sadl), ifp->if_addrlen);
499 		break;
500 
501 	case SIOCSIFMTU:
502 		if (ifv->ifv_p != NULL) {
503 			if (ifr->ifr_mtu >
504 			     (ifv->ifv_p->if_mtu - ifv->ifv_mtufudge) ||
505 			    ifr->ifr_mtu <
506 			     (ifv->ifv_mintu - ifv->ifv_mtufudge))
507 				error = EINVAL;
508 			else
509 				ifp->if_mtu = ifr->ifr_mtu;
510 		} else
511 			error = EINVAL;
512 		break;
513 
514 	case SIOCSETVLAN:
515 		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
516 			break;
517 		if ((error = copyin(ifr->ifr_data, &vlr, sizeof(vlr))) != 0)
518 			break;
519 		if (vlr.vlr_parent[0] == '\0') {
520 			vlan_unconfig(ifp);
521 			break;
522 		}
523 		if (vlr.vlr_tag != EVL_VLANOFTAG(vlr.vlr_tag)) {
524 			error = EINVAL;		 /* check for valid tag */
525 			break;
526 		}
527 		if ((pr = ifunit(vlr.vlr_parent)) == 0) {
528 			error = ENOENT;
529 			break;
530 		}
531 		if ((error = vlan_config(ifv, pr)) != 0)
532 			break;
533 		ifv->ifv_tag = vlr.vlr_tag;
534 		ifp->if_flags |= IFF_RUNNING;
535 
536 		/* Update promiscuous mode, if necessary. */
537 		vlan_set_promisc(ifp);
538 		break;
539 
540 	case SIOCGETVLAN:
541 		memset(&vlr, 0, sizeof(vlr));
542 		if (ifv->ifv_p != NULL) {
543 			snprintf(vlr.vlr_parent, sizeof(vlr.vlr_parent), "%s",
544 			    ifv->ifv_p->if_xname);
545 			vlr.vlr_tag = ifv->ifv_tag;
546 		}
547 		error = copyout(&vlr, ifr->ifr_data, sizeof(vlr));
548 		break;
549 
550 	case SIOCSIFFLAGS:
551 		/*
552 		 * For promiscuous mode, we enable promiscuous mode on
553 		 * the parent if we need promiscuous on the VLAN interface.
554 		 */
555 		if (ifv->ifv_p != NULL)
556 			error = vlan_set_promisc(ifp);
557 		break;
558 
559 	case SIOCADDMULTI:
560 		error = (ifv->ifv_p != NULL) ?
561 		    (*ifv->ifv_msw->vmsw_addmulti)(ifv, ifr) : EINVAL;
562 		break;
563 
564 	case SIOCDELMULTI:
565 		error = (ifv->ifv_p != NULL) ?
566 		    (*ifv->ifv_msw->vmsw_delmulti)(ifv, ifr) : EINVAL;
567 		break;
568 
569 	default:
570 		error = EINVAL;
571 	}
572 
573 	splx(s);
574 
575 	return (error);
576 }
577 
578 static int
579 vlan_ether_addmulti(struct ifvlan *ifv, struct ifreq *ifr)
580 {
581 	struct vlan_mc_entry *mc;
582 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
583 	int error;
584 
585 	if (ifr->ifr_addr.sa_len > sizeof(struct sockaddr_storage))
586 		return (EINVAL);
587 
588 	error = ether_addmulti(ifr, &ifv->ifv_ec);
589 	if (error != ENETRESET)
590 		return (error);
591 
592 	/*
593 	 * This is new multicast address.  We have to tell parent
594 	 * about it.  Also, remember this multicast address so that
595 	 * we can delete them on unconfigure.
596 	 */
597 	MALLOC(mc, struct vlan_mc_entry *, sizeof(struct vlan_mc_entry),
598 	    M_DEVBUF, M_NOWAIT);
599 	if (mc == NULL) {
600 		error = ENOMEM;
601 		goto alloc_failed;
602 	}
603 
604 	/*
605 	 * As ether_addmulti() returns ENETRESET, following two
606 	 * statement shouldn't fail.
607 	 */
608 	(void)ether_multiaddr(&ifr->ifr_addr, addrlo, addrhi);
609 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &ifv->ifv_ec, mc->mc_enm);
610 	memcpy(&mc->mc_addr, &ifr->ifr_addr, ifr->ifr_addr.sa_len);
611 	LIST_INSERT_HEAD(&ifv->ifv_mc_listhead, mc, mc_entries);
612 
613 	error = (*ifv->ifv_p->if_ioctl)(ifv->ifv_p, SIOCADDMULTI,
614 	    (caddr_t)ifr);
615 	if (error != 0)
616 		goto ioctl_failed;
617 	return (error);
618 
619  ioctl_failed:
620 	LIST_REMOVE(mc, mc_entries);
621 	FREE(mc, M_DEVBUF);
622  alloc_failed:
623 	(void)ether_delmulti(ifr, &ifv->ifv_ec);
624 	return (error);
625 }
626 
627 static int
628 vlan_ether_delmulti(struct ifvlan *ifv, struct ifreq *ifr)
629 {
630 	struct ether_multi *enm;
631 	struct vlan_mc_entry *mc;
632 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
633 	int error;
634 
635 	/*
636 	 * Find a key to lookup vlan_mc_entry.  We have to do this
637 	 * before calling ether_delmulti for obvious reason.
638 	 */
639 	if ((error = ether_multiaddr(&ifr->ifr_addr, addrlo, addrhi)) != 0)
640 		return (error);
641 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &ifv->ifv_ec, enm);
642 
643 	error = ether_delmulti(ifr, &ifv->ifv_ec);
644 	if (error != ENETRESET)
645 		return (error);
646 
647 	/* We no longer use this multicast address.  Tell parent so. */
648 	error = (*ifv->ifv_p->if_ioctl)(ifv->ifv_p, SIOCDELMULTI,
649 	    (caddr_t)ifr);
650 	if (error == 0) {
651 		/* And forget about this address. */
652 		for (mc = LIST_FIRST(&ifv->ifv_mc_listhead); mc != NULL;
653 		    mc = LIST_NEXT(mc, mc_entries)) {
654 			if (mc->mc_enm == enm) {
655 				LIST_REMOVE(mc, mc_entries);
656 				FREE(mc, M_DEVBUF);
657 				break;
658 			}
659 		}
660 		KASSERT(mc != NULL);
661 	} else
662 		(void)ether_addmulti(ifr, &ifv->ifv_ec);
663 	return (error);
664 }
665 
666 /*
667  * Delete any multicast address we have asked to add from parent
668  * interface.  Called when the vlan is being unconfigured.
669  */
670 static void
671 vlan_ether_purgemulti(struct ifvlan *ifv)
672 {
673 	struct ifnet *ifp = ifv->ifv_p;		/* Parent. */
674 	struct vlan_mc_entry *mc;
675 	union {
676 		struct ifreq ifreq;
677 		struct {
678 			char ifr_name[IFNAMSIZ];
679 			struct sockaddr_storage ifr_ss;
680 		} ifreq_storage;
681 	} ifreq;
682 	struct ifreq *ifr = &ifreq.ifreq;
683 
684 	memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
685 	while ((mc = LIST_FIRST(&ifv->ifv_mc_listhead)) != NULL) {
686 		memcpy(&ifr->ifr_addr, &mc->mc_addr, mc->mc_addr.ss_len);
687 		(void)(*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)ifr);
688 		LIST_REMOVE(mc, mc_entries);
689 		FREE(mc, M_DEVBUF);
690 	}
691 }
692 
693 static void
694 vlan_start(struct ifnet *ifp)
695 {
696 	struct ifvlan *ifv = ifp->if_softc;
697 	struct ifnet *p = ifv->ifv_p;
698 	struct ethercom *ec = (void *) ifv->ifv_p;
699 	struct mbuf *m;
700 	int error;
701 	ALTQ_DECL(struct altq_pktattr pktattr;)
702 
703 	ifp->if_flags |= IFF_OACTIVE;
704 
705 	for (;;) {
706 		IFQ_DEQUEUE(&ifp->if_snd, m);
707 		if (m == NULL)
708 			break;
709 
710 #ifdef ALTQ
711 		/*
712 		 * If ALTQ is enabled on the parent interface, do
713 		 * classification; the queueing discipline might
714 		 * not require classification, but might require
715 		 * the address family/header pointer in the pktattr.
716 		 */
717 		if (ALTQ_IS_ENABLED(&p->if_snd)) {
718 			switch (p->if_type) {
719 			case IFT_ETHER:
720 				altq_etherclassify(&p->if_snd, m, &pktattr);
721 				break;
722 #ifdef DIAGNOSTIC
723 			default:
724 				panic("vlan_start: impossible (altq)");
725 #endif
726 			}
727 		}
728 #endif /* ALTQ */
729 
730 #if NBPFILTER > 0
731 		if (ifp->if_bpf)
732 			bpf_mtap(ifp->if_bpf, m);
733 #endif
734 		/*
735 		 * If the parent can insert the tag itself, just mark
736 		 * the tag in the mbuf header.
737 		 */
738 		if (ec->ec_capabilities & ETHERCAP_VLAN_HWTAGGING) {
739 			struct m_tag *mtag;
740 
741 			mtag = m_tag_get(PACKET_TAG_VLAN, sizeof(u_int),
742 			    M_NOWAIT);
743 			if (mtag == NULL) {
744 				ifp->if_oerrors++;
745 				m_freem(m);
746 				continue;
747 			}
748 			*(u_int *)(mtag + 1) = ifv->ifv_tag;
749 			m_tag_prepend(m, mtag);
750 		} else {
751 			/*
752 			 * insert the tag ourselves
753 			 */
754 			M_PREPEND(m, ifv->ifv_encaplen, M_DONTWAIT);
755 			if (m == NULL) {
756 				printf("%s: unable to prepend encap header",
757 				    ifv->ifv_p->if_xname);
758 				ifp->if_oerrors++;
759 				continue;
760 			}
761 
762 			switch (p->if_type) {
763 			case IFT_ETHER:
764 			    {
765 				struct ether_vlan_header *evl;
766 
767 				if (m->m_len < sizeof(struct ether_vlan_header))
768 					m = m_pullup(m,
769 					    sizeof(struct ether_vlan_header));
770 				if (m == NULL) {
771 					printf("%s: unable to pullup encap "
772 					    "header", ifv->ifv_p->if_xname);
773 					ifp->if_oerrors++;
774 					continue;
775 				}
776 
777 				/*
778 				 * Transform the Ethernet header into an
779 				 * Ethernet header with 802.1Q encapsulation.
780 				 */
781 				memmove(mtod(m, caddr_t),
782 				    mtod(m, caddr_t) + ifv->ifv_encaplen,
783 				    sizeof(struct ether_header));
784 				evl = mtod(m, struct ether_vlan_header *);
785 				evl->evl_proto = evl->evl_encap_proto;
786 				evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
787 				evl->evl_tag = htons(ifv->ifv_tag);
788 
789 				/*
790 				 * To cater for VLAN-aware layer 2 ethernet
791 				 * switches which may need to strip the tag
792 				 * before forwarding the packet, make sure
793 				 * the packet+tag is at least 68 bytes long.
794 				 * This is necessary because our parent will
795 				 * only pad to 64 bytes (ETHER_MIN_LEN) and
796 				 * some switches will not pad by themselves
797 				 * after deleting a tag.
798 				 */
799 				if (m->m_pkthdr.len <
800 				    (ETHER_MIN_LEN + ETHER_VLAN_ENCAP_LEN)) {
801 					m_copyback(m, m->m_pkthdr.len,
802 					    (ETHER_MIN_LEN +
803 					     ETHER_VLAN_ENCAP_LEN) -
804 					     m->m_pkthdr.len,
805 					    vlan_zero_pad_buff);
806 				}
807 				break;
808 			    }
809 
810 #ifdef DIAGNOSTIC
811 			default:
812 				panic("vlan_start: impossible");
813 #endif
814 			}
815 		}
816 
817 		/*
818 		 * Send it, precisely as the parent's output routine
819 		 * would have.  We are already running at splnet.
820 		 */
821 		IFQ_ENQUEUE(&p->if_snd, m, &pktattr, error);
822 		if (error) {
823 			/* mbuf is already freed */
824 			ifp->if_oerrors++;
825 			continue;
826 		}
827 
828 		ifp->if_opackets++;
829 		if ((p->if_flags & (IFF_RUNNING|IFF_OACTIVE)) == IFF_RUNNING)
830 			(*p->if_start)(p);
831 	}
832 
833 	ifp->if_flags &= ~IFF_OACTIVE;
834 }
835 
836 /*
837  * Given an Ethernet frame, find a valid vlan interface corresponding to the
838  * given source interface and tag, then run the real packet through the
839  * parent's input routine.
840  */
841 void
842 vlan_input(struct ifnet *ifp, struct mbuf *m)
843 {
844 	struct ifvlan *ifv;
845 	u_int tag;
846 	struct m_tag *mtag;
847 
848 	mtag = m_tag_find(m, PACKET_TAG_VLAN, NULL);
849 	if (mtag != NULL) {
850 		/* m contains a normal ethernet frame, the tag is in mtag */
851 		tag = *(u_int *)(mtag + 1);
852 		m_tag_delete(m, mtag);
853 	} else {
854 		switch (ifp->if_type) {
855 		case IFT_ETHER:
856 		    {
857 			struct ether_vlan_header *evl;
858 
859 			if (m->m_len < sizeof(struct ether_vlan_header) &&
860 			    (m = m_pullup(m,
861 			     sizeof(struct ether_vlan_header))) == NULL) {
862 				printf("%s: no memory for VLAN header, "
863 				    "dropping packet.\n", ifp->if_xname);
864 				return;
865 			}
866 			evl = mtod(m, struct ether_vlan_header *);
867 			KASSERT(ntohs(evl->evl_encap_proto) == ETHERTYPE_VLAN);
868 
869 			tag = EVL_VLANOFTAG(ntohs(evl->evl_tag));
870 
871 			/*
872 			 * Restore the original ethertype.  We'll remove
873 			 * the encapsulation after we've found the vlan
874 			 * interface corresponding to the tag.
875 			 */
876 			evl->evl_encap_proto = evl->evl_proto;
877 			break;
878 		    }
879 
880 		default:
881 			tag = (u_int) -1;	/* XXX GCC */
882 #ifdef DIAGNOSTIC
883 			panic("vlan_input: impossible");
884 #endif
885 		}
886 	}
887 
888 	for (ifv = LIST_FIRST(&ifv_list); ifv != NULL;
889 	    ifv = LIST_NEXT(ifv, ifv_list))
890 		if (ifp == ifv->ifv_p && tag == ifv->ifv_tag)
891 			break;
892 
893 	if (ifv == NULL ||
894 	    (ifv->ifv_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
895 	     (IFF_UP|IFF_RUNNING)) {
896 		m_freem(m);
897 		ifp->if_noproto++;
898 		return;
899 	}
900 
901 	/*
902 	 * Now, remove the encapsulation header.  The original
903 	 * header has already been fixed up above.
904 	 */
905 	if (mtag == NULL) {
906 		memmove(mtod(m, caddr_t) + ifv->ifv_encaplen,
907 		    mtod(m, caddr_t), sizeof(struct ether_header));
908 		m_adj(m, ifv->ifv_encaplen);
909 	}
910 
911 	m->m_pkthdr.rcvif = &ifv->ifv_if;
912 	ifv->ifv_if.if_ipackets++;
913 
914 #if NBPFILTER > 0
915 	if (ifv->ifv_if.if_bpf)
916 		bpf_mtap(ifv->ifv_if.if_bpf, m);
917 #endif
918 
919 	/* Pass it back through the parent's input routine. */
920 	(*ifp->if_input)(&ifv->ifv_if, m);
921 }
922