xref: /freebsd/sys/net/if_vlan.c (revision d429ea332342fcb98d27a350d0c4944bf9aec3f9)
1 /*-
2  * Copyright 1998 Massachusetts Institute of Technology
3  *
4  * Permission to use, copy, modify, and distribute this software and
5  * its documentation for any purpose and without fee is hereby
6  * granted, provided that both the above copyright notice and this
7  * permission notice appear in all copies, that both the above
8  * copyright notice and this permission notice appear in all
9  * supporting documentation, and that the name of M.I.T. not be used
10  * in advertising or publicity pertaining to distribution of the
11  * software without specific, written prior permission.  M.I.T. makes
12  * no representations about the suitability of this software for any
13  * purpose.  It is provided "as is" without express or implied
14  * warranty.
15  *
16  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 /*
33  * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.
34  * Might be extended some day to also handle IEEE 802.1p priority
35  * tagging.  This is sort of sneaky in the implementation, since
36  * we need to pretend to be enough of an Ethernet implementation
37  * to make arp work.  The way we do this is by telling everyone
38  * that we are an Ethernet, and then catch the packets that
39  * ether_output() left on our output queue when it calls
40  * if_start(), rewrite them for use by the real outgoing interface,
41  * and ask it to send them.
42  */
43 
44 #include "opt_inet.h"
45 
46 #include <sys/param.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/module.h>
51 #include <sys/queue.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54 #include <sys/sysctl.h>
55 #include <sys/systm.h>
56 
57 #include <net/bpf.h>
58 #include <net/ethernet.h>
59 #include <net/if.h>
60 #include <net/if_clone.h>
61 #include <net/if_arp.h>
62 #include <net/if_dl.h>
63 #include <net/if_types.h>
64 #include <net/if_vlan_var.h>
65 
66 #ifdef INET
67 #include <netinet/in.h>
68 #include <netinet/if_ether.h>
69 #endif
70 
71 #define VLANNAME	"vlan"
72 
73 struct vlan_mc_entry {
74 	struct ether_addr		mc_addr;
75 	SLIST_ENTRY(vlan_mc_entry)	mc_entries;
76 };
77 
78 struct	ifvlan {
79 	struct	ifnet *ifv_ifp;
80 	struct	ifnet *ifv_p;	/* parent inteface of this vlan */
81 	struct	ifv_linkmib {
82 		int	ifvm_parent;
83 		int	ifvm_encaplen;	/* encapsulation length */
84 		int	ifvm_mtufudge;	/* MTU fudged by this much */
85 		int	ifvm_mintu;	/* min transmission unit */
86 		u_int16_t ifvm_proto; /* encapsulation ethertype */
87 		u_int16_t ifvm_tag; /* tag to apply on packets leaving if */
88 	}	ifv_mib;
89 	SLIST_HEAD(__vlan_mchead, vlan_mc_entry)	vlan_mc_listhead;
90 	LIST_ENTRY(ifvlan) ifv_list;
91 	int	ifv_flags;
92 };
93 #define	ifv_tag	ifv_mib.ifvm_tag
94 #define	ifv_encaplen	ifv_mib.ifvm_encaplen
95 #define	ifv_mtufudge	ifv_mib.ifvm_mtufudge
96 #define	ifv_mintu	ifv_mib.ifvm_mintu
97 
98 #define	IFVF_PROMISC	0x01		/* promiscuous mode enabled */
99 
100 SYSCTL_DECL(_net_link);
101 SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN");
102 SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency");
103 
104 static MALLOC_DEFINE(M_VLAN, VLANNAME, "802.1Q Virtual LAN Interface");
105 static LIST_HEAD(, ifvlan) ifv_list;
106 
107 /*
108  * Locking: one lock is used to guard both the ifv_list and modification
109  * to vlan data structures.  We are rather conservative here; probably
110  * more than necessary.
111  */
112 static struct mtx ifv_mtx;
113 #define	VLAN_LOCK_INIT()	mtx_init(&ifv_mtx, VLANNAME, NULL, MTX_DEF)
114 #define	VLAN_LOCK_DESTROY()	mtx_destroy(&ifv_mtx)
115 #define	VLAN_LOCK_ASSERT()	mtx_assert(&ifv_mtx, MA_OWNED)
116 #define	VLAN_LOCK()	mtx_lock(&ifv_mtx)
117 #define	VLAN_UNLOCK()	mtx_unlock(&ifv_mtx)
118 
119 static	void vlan_start(struct ifnet *ifp);
120 static	void vlan_ifinit(void *foo);
121 static	void vlan_input(struct ifnet *ifp, struct mbuf *m);
122 static	int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr);
123 static	int vlan_setmulti(struct ifnet *ifp);
124 static	int vlan_unconfig(struct ifnet *ifp);
125 static	int vlan_config(struct ifvlan *ifv, struct ifnet *p);
126 static	void vlan_link_state(struct ifnet *ifp, int link);
127 static	int vlan_set_promisc(struct ifnet *ifp);
128 
129 static	struct ifnet *vlan_clone_match_ethertag(struct if_clone *,
130     const char *, int *);
131 static	int vlan_clone_match(struct if_clone *, const char *);
132 static	int vlan_clone_create(struct if_clone *, char *, size_t);
133 static	int vlan_clone_destroy(struct if_clone *, struct ifnet *);
134 
135 static	struct if_clone vlan_cloner = IFC_CLONE_INITIALIZER(VLANNAME, NULL,
136     IF_MAXUNIT, NULL, vlan_clone_match, vlan_clone_create, vlan_clone_destroy);
137 
138 /*
139  * Program our multicast filter. What we're actually doing is
140  * programming the multicast filter of the parent. This has the
141  * side effect of causing the parent interface to receive multicast
142  * traffic that it doesn't really want, which ends up being discarded
143  * later by the upper protocol layers. Unfortunately, there's no way
144  * to avoid this: there really is only one physical interface.
145  *
146  * XXX: There is a possible race here if more than one thread is
147  *      modifying the multicast state of the vlan interface at the same time.
148  */
149 static int
150 vlan_setmulti(struct ifnet *ifp)
151 {
152 	struct ifnet		*ifp_p;
153 	struct ifmultiaddr	*ifma, *rifma = NULL;
154 	struct ifvlan		*sc;
155 	struct vlan_mc_entry	*mc = NULL;
156 	struct sockaddr_dl	sdl;
157 	int			error;
158 
159 	/*VLAN_LOCK_ASSERT();*/
160 
161 	/* Find the parent. */
162 	sc = ifp->if_softc;
163 	ifp_p = sc->ifv_p;
164 
165 	/*
166 	 * If we don't have a parent, just remember the membership for
167 	 * when we do.
168 	 */
169 	if (ifp_p == NULL)
170 		return (0);
171 
172 	bzero((char *)&sdl, sizeof(sdl));
173 	sdl.sdl_len = sizeof(sdl);
174 	sdl.sdl_family = AF_LINK;
175 	sdl.sdl_index = ifp_p->if_index;
176 	sdl.sdl_type = IFT_ETHER;
177 	sdl.sdl_alen = ETHER_ADDR_LEN;
178 
179 	/* First, remove any existing filter entries. */
180 	while (SLIST_FIRST(&sc->vlan_mc_listhead) != NULL) {
181 		mc = SLIST_FIRST(&sc->vlan_mc_listhead);
182 		bcopy((char *)&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN);
183 		error = if_delmulti(ifp_p, (struct sockaddr *)&sdl);
184 		if (error)
185 			return (error);
186 		SLIST_REMOVE_HEAD(&sc->vlan_mc_listhead, mc_entries);
187 		free(mc, M_VLAN);
188 	}
189 
190 	/* Now program new ones. */
191 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
192 		if (ifma->ifma_addr->sa_family != AF_LINK)
193 			continue;
194 		mc = malloc(sizeof(struct vlan_mc_entry), M_VLAN, M_NOWAIT);
195 		if (mc == NULL)
196 			return (ENOMEM);
197 		bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
198 		    (char *)&mc->mc_addr, ETHER_ADDR_LEN);
199 		SLIST_INSERT_HEAD(&sc->vlan_mc_listhead, mc, mc_entries);
200 		bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
201 		    LLADDR(&sdl), ETHER_ADDR_LEN);
202 		error = if_addmulti(ifp_p, (struct sockaddr *)&sdl, &rifma);
203 		if (error)
204 			return (error);
205 	}
206 
207 	return (0);
208 }
209 
210 /*
211  * VLAN support can be loaded as a module.  The only place in the
212  * system that's intimately aware of this is ether_input.  We hook
213  * into this code through vlan_input_p which is defined there and
214  * set here.  Noone else in the system should be aware of this so
215  * we use an explicit reference here.
216  *
217  * NB: Noone should ever need to check if vlan_input_p is null or
218  *     not.  This is because interfaces have a count of the number
219  *     of active vlans (if_nvlans) and this should never be bumped
220  *     except by vlan_config--which is in this module so therefore
221  *     the module must be loaded and vlan_input_p must be non-NULL.
222  */
223 extern	void (*vlan_input_p)(struct ifnet *, struct mbuf *);
224 
225 /* For if_link_state_change() eyes only... */
226 extern	void (*vlan_link_state_p)(struct ifnet *, int);
227 
228 static int
229 vlan_modevent(module_t mod, int type, void *data)
230 {
231 
232 	switch (type) {
233 	case MOD_LOAD:
234 		LIST_INIT(&ifv_list);
235 		VLAN_LOCK_INIT();
236 		vlan_input_p = vlan_input;
237 		vlan_link_state_p = vlan_link_state;
238 		if_clone_attach(&vlan_cloner);
239 		break;
240 	case MOD_UNLOAD:
241 		if_clone_detach(&vlan_cloner);
242 		vlan_input_p = NULL;
243 		vlan_link_state_p = NULL;
244 		while (!LIST_EMPTY(&ifv_list))
245 			vlan_clone_destroy(&vlan_cloner,
246 			    LIST_FIRST(&ifv_list)->ifv_ifp);
247 		VLAN_LOCK_DESTROY();
248 		break;
249 	default:
250 		return (EOPNOTSUPP);
251 	}
252 	return (0);
253 }
254 
255 static moduledata_t vlan_mod = {
256 	"if_vlan",
257 	vlan_modevent,
258 	0
259 };
260 
261 DECLARE_MODULE(if_vlan, vlan_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
262 MODULE_DEPEND(if_vlan, miibus, 1, 1, 1);
263 
264 static struct ifnet *
265 vlan_clone_match_ethertag(struct if_clone *ifc, const char *name, int *tag)
266 {
267 	const char *cp;
268 	struct ifnet *ifp;
269 	int t = 0;
270 
271 	/* Check for <etherif>.<vlan> style interface names. */
272 	IFNET_RLOCK();
273 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
274 		if (ifp->if_type != IFT_ETHER)
275 			continue;
276 		if (strncmp(ifp->if_xname, name, strlen(ifp->if_xname)) != 0)
277 			continue;
278 		cp = name + strlen(ifp->if_xname);
279 		if (*cp != '.')
280 			continue;
281 		for(; *cp != '\0'; cp++) {
282 			if (*cp < '0' || *cp > '9')
283 				continue;
284 			t = (t * 10) + (*cp - '0');
285 		}
286 		if (tag != NULL)
287 			*tag = t;
288 		break;
289 	}
290 	IFNET_RUNLOCK();
291 
292 	return (ifp);
293 }
294 
295 static int
296 vlan_clone_match(struct if_clone *ifc, const char *name)
297 {
298 	const char *cp;
299 
300 	if (vlan_clone_match_ethertag(ifc, name, NULL) != NULL)
301 		return (1);
302 
303 	if (strncmp(VLANNAME, name, strlen(VLANNAME)) != 0)
304 		return (0);
305 	for (cp = name + 4; *cp != '\0'; cp++) {
306 		if (*cp < '0' || *cp > '9')
307 			return (0);
308 	}
309 
310 	return (1);
311 }
312 
313 static int
314 vlan_clone_create(struct if_clone *ifc, char *name, size_t len)
315 {
316 	char *dp;
317 	int wildcard;
318 	int unit;
319 	int error;
320 	int tag;
321 	int ethertag;
322 	struct ifvlan *ifv;
323 	struct ifnet *ifp;
324 	struct ifnet *p;
325 	u_char eaddr[6] = {0,0,0,0,0,0};
326 
327 	if ((p = vlan_clone_match_ethertag(ifc, name, &tag)) != NULL) {
328 		ethertag = 1;
329 		unit = -1;
330 		wildcard = 0;
331 
332 		/*
333 		 * Don't let the caller set up a VLAN tag with
334 		 * anything except VLID bits.
335 		 */
336 		if (tag & ~EVL_VLID_MASK)
337 			return (EINVAL);
338 	} else {
339 		ethertag = 0;
340 
341 		error = ifc_name2unit(name, &unit);
342 		if (error != 0)
343 			return (error);
344 
345 		wildcard = (unit < 0);
346 	}
347 
348 	error = ifc_alloc_unit(ifc, &unit);
349 	if (error != 0)
350 		return (error);
351 
352 	/* In the wildcard case, we need to update the name. */
353 	if (wildcard) {
354 		for (dp = name; *dp != '\0'; dp++);
355 		if (snprintf(dp, len - (dp-name), "%d", unit) >
356 		    len - (dp-name) - 1) {
357 			panic("%s: interface name too long", __func__);
358 		}
359 	}
360 
361 	ifv = malloc(sizeof(struct ifvlan), M_VLAN, M_WAITOK | M_ZERO);
362 	ifp = ifv->ifv_ifp = if_alloc(IFT_ETHER);
363 	if (ifp == NULL) {
364 		ifc_free_unit(ifc, unit);
365 		free(ifv, M_VLAN);
366 		return (ENOSPC);
367 	}
368 	SLIST_INIT(&ifv->vlan_mc_listhead);
369 
370 	ifp->if_softc = ifv;
371 	/*
372 	 * Set the name manually rather than using if_initname because
373 	 * we don't conform to the default naming convention for interfaces.
374 	 */
375 	strlcpy(ifp->if_xname, name, IFNAMSIZ);
376 	ifp->if_dname = ifc->ifc_name;
377 	ifp->if_dunit = unit;
378 	/* NB: flags are not set here */
379 	ifp->if_linkmib = &ifv->ifv_mib;
380 	ifp->if_linkmiblen = sizeof(ifv->ifv_mib);
381 	/* NB: mtu is not set here */
382 
383 	ifp->if_init = vlan_ifinit;
384 	ifp->if_start = vlan_start;
385 	ifp->if_ioctl = vlan_ioctl;
386 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
387 	ether_ifattach(ifp, eaddr);
388 	/* Now undo some of the damage... */
389 	ifp->if_baudrate = 0;
390 	ifp->if_type = IFT_L2VLAN;
391 	ifp->if_hdrlen = ETHER_VLAN_ENCAP_LEN;
392 
393 	VLAN_LOCK();
394 	LIST_INSERT_HEAD(&ifv_list, ifv, ifv_list);
395 	VLAN_UNLOCK();
396 
397 	if (ethertag) {
398 		VLAN_LOCK();
399 		error = vlan_config(ifv, p);
400 		if (error != 0) {
401 			/*
402 			 * Since we've partialy failed, we need to back
403 			 * out all the way, otherwise userland could get
404 			 * confused.  Thus, we destroy the interface.
405 			 */
406 			LIST_REMOVE(ifv, ifv_list);
407 			vlan_unconfig(ifp);
408 			VLAN_UNLOCK();
409 			ether_ifdetach(ifp);
410 			if_free_type(ifp, IFT_ETHER);
411 			free(ifv, M_VLAN);
412 
413 			return (error);
414 		}
415 		ifv->ifv_tag = tag;
416 		ifp->if_flags |= IFF_RUNNING;
417 		VLAN_UNLOCK();
418 
419 		/* Update promiscuous mode, if necessary. */
420 		vlan_set_promisc(ifp);
421 	}
422 
423 	return (0);
424 }
425 
426 static int
427 vlan_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
428 {
429 	int unit;
430 	struct ifvlan *ifv = ifp->if_softc;
431 
432 	unit = ifp->if_dunit;
433 
434 	VLAN_LOCK();
435 	LIST_REMOVE(ifv, ifv_list);
436 	vlan_unconfig(ifp);
437 	VLAN_UNLOCK();
438 
439 	ether_ifdetach(ifp);
440 	if_free(ifp);
441 
442 	free(ifv, M_VLAN);
443 
444 	ifc_free_unit(ifc, unit);
445 
446 	return (0);
447 }
448 
449 /*
450  * The ifp->if_init entry point for vlan(4) is a no-op.
451  */
452 static void
453 vlan_ifinit(void *foo)
454 {
455 
456 }
457 
458 static void
459 vlan_start(struct ifnet *ifp)
460 {
461 	struct ifvlan *ifv;
462 	struct ifnet *p;
463 	struct ether_vlan_header *evl;
464 	struct mbuf *m;
465 	int error;
466 
467 	ifv = ifp->if_softc;
468 	p = ifv->ifv_p;
469 
470 	ifp->if_flags |= IFF_OACTIVE;
471 	for (;;) {
472 		IF_DEQUEUE(&ifp->if_snd, m);
473 		if (m == 0)
474 			break;
475 		BPF_MTAP(ifp, m);
476 
477 		/*
478 		 * Do not run parent's if_start() if the parent is not up,
479 		 * or parent's driver will cause a system crash.
480 		 */
481 		if ((p->if_flags & (IFF_UP | IFF_RUNNING)) !=
482 					(IFF_UP | IFF_RUNNING)) {
483 			m_freem(m);
484 			ifp->if_collisions++;
485 			continue;
486 		}
487 
488 		/*
489 		 * If underlying interface can do VLAN tag insertion itself,
490 		 * just pass the packet along. However, we need some way to
491 		 * tell the interface where the packet came from so that it
492 		 * knows how to find the VLAN tag to use, so we attach a
493 		 * packet tag that holds it.
494 		 */
495 		if (p->if_capenable & IFCAP_VLAN_HWTAGGING) {
496 			struct m_tag *mtag = m_tag_alloc(MTAG_VLAN,
497 							 MTAG_VLAN_TAG,
498 							 sizeof(u_int),
499 							 M_NOWAIT);
500 			if (mtag == NULL) {
501 				ifp->if_oerrors++;
502 				m_freem(m);
503 				continue;
504 			}
505 			*(u_int*)(mtag + 1) = ifv->ifv_tag;
506 			m_tag_prepend(m, mtag);
507 		} else {
508 			M_PREPEND(m, ifv->ifv_encaplen, M_DONTWAIT);
509 			if (m == NULL) {
510 				if_printf(ifp,
511 				    "unable to prepend VLAN header\n");
512 				ifp->if_oerrors++;
513 				continue;
514 			}
515 			/* M_PREPEND takes care of m_len, m_pkthdr.len for us */
516 
517 			if (m->m_len < sizeof(*evl)) {
518 				m = m_pullup(m, sizeof(*evl));
519 				if (m == NULL) {
520 					if_printf(ifp,
521 					    "cannot pullup VLAN header\n");
522 					ifp->if_oerrors++;
523 					continue;
524 				}
525 			}
526 
527 			/*
528 			 * Transform the Ethernet header into an Ethernet header
529 			 * with 802.1Q encapsulation.
530 			 */
531 			bcopy(mtod(m, char *) + ifv->ifv_encaplen,
532 			      mtod(m, char *), ETHER_HDR_LEN);
533 			evl = mtod(m, struct ether_vlan_header *);
534 			evl->evl_proto = evl->evl_encap_proto;
535 			evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
536 			evl->evl_tag = htons(ifv->ifv_tag);
537 #ifdef DEBUG
538 			printf("vlan_start: %*D\n", (int)sizeof(*evl),
539 			    (unsigned char *)evl, ":");
540 #endif
541 		}
542 
543 		/*
544 		 * Send it, precisely as ether_output() would have.
545 		 * We are already running at splimp.
546 		 */
547 		IFQ_HANDOFF(p, m, error);
548 		if (!error)
549 			ifp->if_opackets++;
550 		else
551 			ifp->if_oerrors++;
552 	}
553 	ifp->if_flags &= ~IFF_OACTIVE;
554 }
555 
556 static void
557 vlan_input(struct ifnet *ifp, struct mbuf *m)
558 {
559 	struct ether_vlan_header *evl;
560 	struct ifvlan *ifv;
561 	struct m_tag *mtag;
562 	u_int tag;
563 
564 	mtag = m_tag_locate(m, MTAG_VLAN, MTAG_VLAN_TAG, NULL);
565 	if (mtag != NULL) {
566 		/*
567 		 * Packet is tagged, m contains a normal
568 		 * Ethernet frame; the tag is stored out-of-band.
569 		 */
570 		tag = EVL_VLANOFTAG(VLAN_TAG_VALUE(mtag));
571 		m_tag_delete(m, mtag);
572 		m->m_flags &= ~M_VLANTAG;
573 	} else {
574 		switch (ifp->if_type) {
575 		case IFT_ETHER:
576 			if (m->m_len < sizeof(*evl) &&
577 			    (m = m_pullup(m, sizeof(*evl))) == NULL) {
578 				if_printf(ifp, "cannot pullup VLAN header\n");
579 				return;
580 			}
581 			evl = mtod(m, struct ether_vlan_header *);
582 			KASSERT(ntohs(evl->evl_encap_proto) == ETHERTYPE_VLAN,
583 				("vlan_input: bad encapsulated protocols (%u)",
584 				 ntohs(evl->evl_encap_proto)));
585 
586 			tag = EVL_VLANOFTAG(ntohs(evl->evl_tag));
587 
588 			/*
589 			 * Restore the original ethertype.  We'll remove
590 			 * the encapsulation after we've found the vlan
591 			 * interface corresponding to the tag.
592 			 */
593 			evl->evl_encap_proto = evl->evl_proto;
594 			break;
595 		default:
596 			tag = (u_int) -1;
597 #ifdef DIAGNOSTIC
598 			panic("vlan_input: unsupported if type %u",
599 			    ifp->if_type);
600 #endif
601 			break;
602 		}
603 	}
604 
605 	VLAN_LOCK();
606 	LIST_FOREACH(ifv, &ifv_list, ifv_list)
607 		if (ifp == ifv->ifv_p && tag == ifv->ifv_tag)
608 			break;
609 
610 	if (ifv == NULL || (ifv->ifv_ifp->if_flags & IFF_UP) == 0) {
611 		VLAN_UNLOCK();
612 		m_freem(m);
613 		ifp->if_noproto++;
614 #ifdef DEBUG
615 		printf("vlan_input: tag %d, no interface\n", tag);
616 #endif
617 		return;
618 	}
619 	VLAN_UNLOCK();		/* XXX extend below? */
620 #ifdef DEBUG
621 	printf("vlan_input: tag %d, parent %s\n", tag, ifv->ifv_p->if_xname);
622 #endif
623 
624 	if (mtag == NULL) {
625 		/*
626 		 * Packet had an in-line encapsulation header;
627 		 * remove it.  The original header has already
628 		 * been fixed up above.
629 		 */
630 		bcopy(mtod(m, caddr_t),
631 		      mtod(m, caddr_t) + ETHER_VLAN_ENCAP_LEN,
632 		      ETHER_HDR_LEN);
633 		m_adj(m, ETHER_VLAN_ENCAP_LEN);
634 	}
635 
636 	m->m_pkthdr.rcvif = ifv->ifv_ifp;
637 	ifv->ifv_ifp->if_ipackets++;
638 
639 	/* Pass it back through the parent's input routine. */
640 	(*ifp->if_input)(ifv->ifv_ifp, m);
641 }
642 
643 static int
644 vlan_config(struct ifvlan *ifv, struct ifnet *p)
645 {
646 	struct ifaddr *ifa1, *ifa2;
647 	struct sockaddr_dl *sdl1, *sdl2;
648 
649 	VLAN_LOCK_ASSERT();
650 
651 	if (p->if_data.ifi_type != IFT_ETHER)
652 		return (EPROTONOSUPPORT);
653 	if (ifv->ifv_p)
654 		return (EBUSY);
655 
656 	ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN;
657 	ifv->ifv_mintu = ETHERMIN;
658 	ifv->ifv_flags = 0;
659 
660 	/*
661 	 * The active VLAN counter on the parent is used
662 	 * at various places to see if there is a vlan(4)
663 	 * attached to this physical interface.
664 	 */
665 	p->if_nvlans++;
666 
667 	/*
668 	 * If the parent supports the VLAN_MTU capability,
669 	 * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames,
670 	 * use it.
671 	 */
672 	if (p->if_capenable & IFCAP_VLAN_MTU) {
673 		/*
674 		 * No need to fudge the MTU since the parent can
675 		 * handle extended frames.
676 		 */
677 		ifv->ifv_mtufudge = 0;
678 	} else {
679 		/*
680 		 * Fudge the MTU by the encapsulation size.  This
681 		 * makes us incompatible with strictly compliant
682 		 * 802.1Q implementations, but allows us to use
683 		 * the feature with other NetBSD implementations,
684 		 * which might still be useful.
685 		 */
686 		ifv->ifv_mtufudge = ifv->ifv_encaplen;
687 	}
688 
689 	ifv->ifv_p = p;
690 	ifv->ifv_ifp->if_mtu = p->if_mtu - ifv->ifv_mtufudge;
691 	/*
692 	 * Copy only a selected subset of flags from the parent.
693 	 * Other flags are none of our business.
694 	 */
695 	ifv->ifv_ifp->if_flags = (p->if_flags &
696 	    (IFF_BROADCAST | IFF_MULTICAST | IFF_SIMPLEX | IFF_POINTOPOINT));
697 	ifv->ifv_ifp->if_link_state = p->if_link_state;
698 
699 #if 0
700 	/*
701 	 * Not ready yet.  We need notification from the parent
702 	 * when hw checksumming flags in its if_capenable change.
703 	 * Flags set in if_capabilities only are useless.
704 	 */
705 	/*
706 	 * If the parent interface can do hardware-assisted
707 	 * VLAN encapsulation, then propagate its hardware-
708 	 * assisted checksumming flags.
709 	 */
710 	if (p->if_capabilities & IFCAP_VLAN_HWTAGGING)
711 		ifv->ifv_ifpif_capabilities |= p->if_capabilities & IFCAP_HWCSUM;
712 #endif
713 
714 	/*
715 	 * Set up our ``Ethernet address'' to reflect the underlying
716 	 * physical interface's.
717 	 */
718 	ifa1 = ifaddr_byindex(ifv->ifv_ifp->if_index);
719 	ifa2 = ifaddr_byindex(p->if_index);
720 	sdl1 = (struct sockaddr_dl *)ifa1->ifa_addr;
721 	sdl2 = (struct sockaddr_dl *)ifa2->ifa_addr;
722 	sdl1->sdl_type = IFT_ETHER;
723 	sdl1->sdl_alen = ETHER_ADDR_LEN;
724 	bcopy(LLADDR(sdl2), LLADDR(sdl1), ETHER_ADDR_LEN);
725 	bcopy(LLADDR(sdl2), IFP2ENADDR(ifv->ifv_ifp), ETHER_ADDR_LEN);
726 
727 	/*
728 	 * Configure multicast addresses that may already be
729 	 * joined on the vlan device.
730 	 */
731 	(void)vlan_setmulti(ifv->ifv_ifp); /* XXX: VLAN lock held */
732 
733 	return (0);
734 }
735 
736 static int
737 vlan_unconfig(struct ifnet *ifp)
738 {
739 	struct ifaddr *ifa;
740 	struct sockaddr_dl *sdl;
741 	struct vlan_mc_entry *mc;
742 	struct ifvlan *ifv;
743 	struct ifnet *p;
744 	int error;
745 
746 	VLAN_LOCK_ASSERT();
747 
748 	ifv = ifp->if_softc;
749 	p = ifv->ifv_p;
750 
751 	if (p) {
752 		struct sockaddr_dl sdl;
753 
754 		/*
755 		 * Since the interface is being unconfigured, we need to
756 		 * empty the list of multicast groups that we may have joined
757 		 * while we were alive from the parent's list.
758 		 */
759 		bzero((char *)&sdl, sizeof(sdl));
760 		sdl.sdl_len = sizeof(sdl);
761 		sdl.sdl_family = AF_LINK;
762 		sdl.sdl_index = p->if_index;
763 		sdl.sdl_type = IFT_ETHER;
764 		sdl.sdl_alen = ETHER_ADDR_LEN;
765 
766 		while(SLIST_FIRST(&ifv->vlan_mc_listhead) != NULL) {
767 			mc = SLIST_FIRST(&ifv->vlan_mc_listhead);
768 			bcopy((char *)&mc->mc_addr, LLADDR(&sdl),
769 			    ETHER_ADDR_LEN);
770 			error = if_delmulti(p, (struct sockaddr *)&sdl);
771 			if (error)
772 				return (error);
773 			SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
774 			free(mc, M_VLAN);
775 		}
776 
777 		p->if_nvlans--;
778 	}
779 
780 	/* Disconnect from parent. */
781 	ifv->ifv_p = NULL;
782 	ifv->ifv_ifp->if_mtu = ETHERMTU;		/* XXX why not 0? */
783 	ifv->ifv_flags = 0;
784 	ifv->ifv_ifp->if_link_state = LINK_STATE_UNKNOWN;
785 
786 	/* Clear our MAC address. */
787 	ifa = ifaddr_byindex(ifv->ifv_ifp->if_index);
788 	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
789 	sdl->sdl_type = IFT_ETHER;
790 	sdl->sdl_alen = ETHER_ADDR_LEN;
791 	bzero(LLADDR(sdl), ETHER_ADDR_LEN);
792 	bzero(IFP2ENADDR(ifv->ifv_ifp), ETHER_ADDR_LEN);
793 
794 	return (0);
795 }
796 
797 static int
798 vlan_set_promisc(struct ifnet *ifp)
799 {
800 	struct ifvlan *ifv = ifp->if_softc;
801 	int error = 0;
802 
803 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
804 		if ((ifv->ifv_flags & IFVF_PROMISC) == 0) {
805 			error = ifpromisc(ifv->ifv_p, 1);
806 			if (error == 0)
807 				ifv->ifv_flags |= IFVF_PROMISC;
808 		}
809 	} else {
810 		if ((ifv->ifv_flags & IFVF_PROMISC) != 0) {
811 			error = ifpromisc(ifv->ifv_p, 0);
812 			if (error == 0)
813 				ifv->ifv_flags &= ~IFVF_PROMISC;
814 		}
815 	}
816 
817 	return (error);
818 }
819 
820 /* Inform all vlans that their parent has changed link state */
821 static void
822 vlan_link_state(struct ifnet *ifp, int link)
823 {
824 	struct ifvlan *ifv;
825 
826 	VLAN_LOCK();
827 	LIST_FOREACH(ifv, &ifv_list, ifv_list) {
828 		if (ifv->ifv_p == ifp)
829 			if_link_state_change(ifv->ifv_ifp,
830 			    ifv->ifv_p->if_link_state);
831 	}
832 	VLAN_UNLOCK();
833 }
834 
835 static int
836 vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
837 {
838 	struct ifaddr *ifa;
839 	struct ifnet *p;
840 	struct ifreq *ifr;
841 	struct ifvlan *ifv;
842 	struct vlanreq vlr;
843 	int error = 0;
844 
845 	ifr = (struct ifreq *)data;
846 	ifa = (struct ifaddr *)data;
847 	ifv = ifp->if_softc;
848 
849 	switch (cmd) {
850 	case SIOCSIFADDR:
851 		ifp->if_flags |= IFF_UP;
852 
853 		switch (ifa->ifa_addr->sa_family) {
854 #ifdef INET
855 		case AF_INET:
856 			arp_ifinit(ifv->ifv_ifp, ifa);
857 			break;
858 #endif
859 		default:
860 			break;
861 		}
862 		break;
863 
864 	case SIOCGIFADDR:
865 		{
866 			struct sockaddr *sa;
867 
868 			sa = (struct sockaddr *) &ifr->ifr_data;
869 			bcopy(IFP2ENADDR(ifp), (caddr_t)sa->sa_data,
870 			    ETHER_ADDR_LEN);
871 		}
872 		break;
873 
874 	case SIOCGIFMEDIA:
875 		VLAN_LOCK();
876 		if (ifv->ifv_p != NULL) {
877 			error = (*ifv->ifv_p->if_ioctl)(ifv->ifv_p,
878 					SIOCGIFMEDIA, data);
879 			VLAN_UNLOCK();
880 			/* Limit the result to the parent's current config. */
881 			if (error == 0) {
882 				struct ifmediareq *ifmr;
883 
884 				ifmr = (struct ifmediareq *)data;
885 				if (ifmr->ifm_count >= 1 && ifmr->ifm_ulist) {
886 					ifmr->ifm_count = 1;
887 					error = copyout(&ifmr->ifm_current,
888 						ifmr->ifm_ulist,
889 						sizeof(int));
890 				}
891 			}
892 		} else {
893 			VLAN_UNLOCK();
894 			error = EINVAL;
895 		}
896 		break;
897 
898 	case SIOCSIFMEDIA:
899 		error = EINVAL;
900 		break;
901 
902 	case SIOCSIFMTU:
903 		/*
904 		 * Set the interface MTU.
905 		 */
906 		VLAN_LOCK();
907 		if (ifv->ifv_p != NULL) {
908 			if (ifr->ifr_mtu >
909 			     (ifv->ifv_p->if_mtu - ifv->ifv_mtufudge) ||
910 			    ifr->ifr_mtu <
911 			     (ifv->ifv_mintu - ifv->ifv_mtufudge))
912 				error = EINVAL;
913 			else
914 				ifp->if_mtu = ifr->ifr_mtu;
915 		} else
916 			error = EINVAL;
917 		VLAN_UNLOCK();
918 		break;
919 
920 	case SIOCSETVLAN:
921 		error = copyin(ifr->ifr_data, &vlr, sizeof(vlr));
922 		if (error)
923 			break;
924 		if (vlr.vlr_parent[0] == '\0') {
925 			VLAN_LOCK();
926 			vlan_unconfig(ifp);
927 			if (ifp->if_flags & IFF_UP)
928 				if_down(ifp);
929 			ifp->if_flags &= ~IFF_RUNNING;
930 			VLAN_UNLOCK();
931 			break;
932 		}
933 		p = ifunit(vlr.vlr_parent);
934 		if (p == 0) {
935 			error = ENOENT;
936 			break;
937 		}
938 		/*
939 		 * Don't let the caller set up a VLAN tag with
940 		 * anything except VLID bits.
941 		 */
942 		if (vlr.vlr_tag & ~EVL_VLID_MASK) {
943 			error = EINVAL;
944 			break;
945 		}
946 		VLAN_LOCK();
947 		error = vlan_config(ifv, p);
948 		if (error) {
949 			VLAN_UNLOCK();
950 			break;
951 		}
952 		ifv->ifv_tag = vlr.vlr_tag;
953 		ifp->if_flags |= IFF_RUNNING;
954 		VLAN_UNLOCK();
955 
956 		/* Update promiscuous mode, if necessary. */
957 		vlan_set_promisc(ifp);
958 		break;
959 
960 	case SIOCGETVLAN:
961 		bzero(&vlr, sizeof(vlr));
962 		VLAN_LOCK();
963 		if (ifv->ifv_p) {
964 			strlcpy(vlr.vlr_parent, ifv->ifv_p->if_xname,
965 			    sizeof(vlr.vlr_parent));
966 			vlr.vlr_tag = ifv->ifv_tag;
967 		}
968 		VLAN_UNLOCK();
969 		error = copyout(&vlr, ifr->ifr_data, sizeof(vlr));
970 		break;
971 
972 	case SIOCSIFFLAGS:
973 		/*
974 		 * For promiscuous mode, we enable promiscuous mode on
975 		 * the parent if we need promiscuous on the VLAN interface.
976 		 */
977 		if (ifv->ifv_p != NULL)
978 			error = vlan_set_promisc(ifp);
979 		break;
980 
981 	case SIOCADDMULTI:
982 	case SIOCDELMULTI:
983 		/*VLAN_LOCK();*/
984 		error = vlan_setmulti(ifp);
985 		/*VLAN_UNLOCK();*/
986 		break;
987 	default:
988 		error = EINVAL;
989 	}
990 
991 	return (error);
992 }
993