xref: /freebsd/sys/net/if_vlan.c (revision 6356dba0b403daa023dec24559ab1f8e602e4f14)
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_vlan.h"
45 
46 #include <sys/param.h>
47 #include <sys/kernel.h>
48 #include <sys/lock.h>
49 #include <sys/malloc.h>
50 #include <sys/mbuf.h>
51 #include <sys/module.h>
52 #include <sys/rwlock.h>
53 #include <sys/queue.h>
54 #include <sys/socket.h>
55 #include <sys/sockio.h>
56 #include <sys/sysctl.h>
57 #include <sys/systm.h>
58 #include <sys/vimage.h>
59 
60 #include <net/bpf.h>
61 #include <net/ethernet.h>
62 #include <net/if.h>
63 #include <net/if_clone.h>
64 #include <net/if_dl.h>
65 #include <net/if_types.h>
66 #include <net/if_vlan_var.h>
67 
68 #define VLANNAME	"vlan"
69 #define	VLAN_DEF_HWIDTH	4
70 #define	VLAN_IFFLAGS	(IFF_BROADCAST | IFF_MULTICAST)
71 
72 #define	UP_AND_RUNNING(ifp) \
73     ((ifp)->if_flags & IFF_UP && (ifp)->if_drv_flags & IFF_DRV_RUNNING)
74 
75 LIST_HEAD(ifvlanhead, ifvlan);
76 
77 struct ifvlantrunk {
78 	struct	ifnet   *parent;	/* parent interface of this trunk */
79 	struct	rwlock	rw;
80 #ifdef VLAN_ARRAY
81 #define	VLAN_ARRAY_SIZE	(EVL_VLID_MASK + 1)
82 	struct	ifvlan	*vlans[VLAN_ARRAY_SIZE]; /* static table */
83 #else
84 	struct	ifvlanhead *hash;	/* dynamic hash-list table */
85 	uint16_t	hmask;
86 	uint16_t	hwidth;
87 #endif
88 	int		refcnt;
89 };
90 
91 struct vlan_mc_entry {
92 	struct ether_addr		mc_addr;
93 	SLIST_ENTRY(vlan_mc_entry)	mc_entries;
94 };
95 
96 struct	ifvlan {
97 	struct	ifvlantrunk *ifv_trunk;
98 	struct	ifnet *ifv_ifp;
99 #define	TRUNK(ifv)	((ifv)->ifv_trunk)
100 #define	PARENT(ifv)	((ifv)->ifv_trunk->parent)
101 	int	ifv_pflags;	/* special flags we have set on parent */
102 	struct	ifv_linkmib {
103 		int	ifvm_encaplen;	/* encapsulation length */
104 		int	ifvm_mtufudge;	/* MTU fudged by this much */
105 		int	ifvm_mintu;	/* min transmission unit */
106 		uint16_t ifvm_proto;	/* encapsulation ethertype */
107 		uint16_t ifvm_tag;	/* tag to apply on packets leaving if */
108 	}	ifv_mib;
109 	SLIST_HEAD(, vlan_mc_entry) vlan_mc_listhead;
110 #ifndef VLAN_ARRAY
111 	LIST_ENTRY(ifvlan) ifv_list;
112 #endif
113 };
114 #define	ifv_proto	ifv_mib.ifvm_proto
115 #define	ifv_tag		ifv_mib.ifvm_tag
116 #define	ifv_encaplen	ifv_mib.ifvm_encaplen
117 #define	ifv_mtufudge	ifv_mib.ifvm_mtufudge
118 #define	ifv_mintu	ifv_mib.ifvm_mintu
119 
120 /* Special flags we should propagate to parent. */
121 static struct {
122 	int flag;
123 	int (*func)(struct ifnet *, int);
124 } vlan_pflags[] = {
125 	{IFF_PROMISC, ifpromisc},
126 	{IFF_ALLMULTI, if_allmulti},
127 	{0, NULL}
128 };
129 
130 SYSCTL_DECL(_net_link);
131 SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN");
132 SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency");
133 
134 static int soft_pad = 0;
135 SYSCTL_INT(_net_link_vlan, OID_AUTO, soft_pad, CTLFLAG_RW, &soft_pad, 0,
136 	   "pad short frames before tagging");
137 
138 static MALLOC_DEFINE(M_VLAN, VLANNAME, "802.1Q Virtual LAN Interface");
139 
140 static eventhandler_tag ifdetach_tag;
141 
142 /*
143  * We have a global mutex, that is used to serialize configuration
144  * changes and isn't used in normal packet delivery.
145  *
146  * We also have a per-trunk rwlock, that is locked shared on packet
147  * processing and exclusive when configuration is changed.
148  *
149  * The VLAN_ARRAY substitutes the dynamic hash with a static array
150  * with 4096 entries. In theory this can give a boost in processing,
151  * however on practice it does not. Probably this is because array
152  * is too big to fit into CPU cache.
153  */
154 static struct mtx ifv_mtx;
155 #define	VLAN_LOCK_INIT()	mtx_init(&ifv_mtx, "vlan_global", NULL, MTX_DEF)
156 #define	VLAN_LOCK_DESTROY()	mtx_destroy(&ifv_mtx)
157 #define	VLAN_LOCK_ASSERT()	mtx_assert(&ifv_mtx, MA_OWNED)
158 #define	VLAN_LOCK()		mtx_lock(&ifv_mtx)
159 #define	VLAN_UNLOCK()		mtx_unlock(&ifv_mtx)
160 #define	TRUNK_LOCK_INIT(trunk)	rw_init(&(trunk)->rw, VLANNAME)
161 #define	TRUNK_LOCK_DESTROY(trunk) rw_destroy(&(trunk)->rw)
162 #define	TRUNK_LOCK(trunk)	rw_wlock(&(trunk)->rw)
163 #define	TRUNK_UNLOCK(trunk)	rw_wunlock(&(trunk)->rw)
164 #define	TRUNK_LOCK_ASSERT(trunk) rw_assert(&(trunk)->rw, RA_WLOCKED)
165 #define	TRUNK_RLOCK(trunk)	rw_rlock(&(trunk)->rw)
166 #define	TRUNK_RUNLOCK(trunk)	rw_runlock(&(trunk)->rw)
167 #define	TRUNK_LOCK_RASSERT(trunk) rw_assert(&(trunk)->rw, RA_RLOCKED)
168 
169 #ifndef VLAN_ARRAY
170 static	void vlan_inithash(struct ifvlantrunk *trunk);
171 static	void vlan_freehash(struct ifvlantrunk *trunk);
172 static	int vlan_inshash(struct ifvlantrunk *trunk, struct ifvlan *ifv);
173 static	int vlan_remhash(struct ifvlantrunk *trunk, struct ifvlan *ifv);
174 static	void vlan_growhash(struct ifvlantrunk *trunk, int howmuch);
175 static __inline struct ifvlan * vlan_gethash(struct ifvlantrunk *trunk,
176 	uint16_t tag);
177 #endif
178 static	void trunk_destroy(struct ifvlantrunk *trunk);
179 
180 static	void vlan_start(struct ifnet *ifp);
181 static	void vlan_init(void *foo);
182 static	void vlan_input(struct ifnet *ifp, struct mbuf *m);
183 static	int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr);
184 static	int vlan_setflag(struct ifnet *ifp, int flag, int status,
185     int (*func)(struct ifnet *, int));
186 static	int vlan_setflags(struct ifnet *ifp, int status);
187 static	int vlan_setmulti(struct ifnet *ifp);
188 static	int vlan_unconfig(struct ifnet *ifp);
189 static	int vlan_unconfig_locked(struct ifnet *ifp);
190 static	int vlan_config(struct ifvlan *ifv, struct ifnet *p, uint16_t tag);
191 static	void vlan_link_state(struct ifnet *ifp, int link);
192 static	void vlan_capabilities(struct ifvlan *ifv);
193 static	void vlan_trunk_capabilities(struct ifnet *ifp);
194 
195 static	struct ifnet *vlan_clone_match_ethertag(struct if_clone *,
196     const char *, int *);
197 static	int vlan_clone_match(struct if_clone *, const char *);
198 static	int vlan_clone_create(struct if_clone *, char *, size_t, caddr_t);
199 static	int vlan_clone_destroy(struct if_clone *, struct ifnet *);
200 
201 static	void vlan_ifdetach(void *arg, struct ifnet *ifp);
202 
203 static	struct if_clone vlan_cloner = IFC_CLONE_INITIALIZER(VLANNAME, NULL,
204     IF_MAXUNIT, NULL, vlan_clone_match, vlan_clone_create, vlan_clone_destroy);
205 
206 #ifndef VLAN_ARRAY
207 #define HASH(n, m)	((((n) >> 8) ^ ((n) >> 4) ^ (n)) & (m))
208 
209 static void
210 vlan_inithash(struct ifvlantrunk *trunk)
211 {
212 	int i, n;
213 
214 	/*
215 	 * The trunk must not be locked here since we call malloc(M_WAITOK).
216 	 * It is OK in case this function is called before the trunk struct
217 	 * gets hooked up and becomes visible from other threads.
218 	 */
219 
220 	KASSERT(trunk->hwidth == 0 && trunk->hash == NULL,
221 	    ("%s: hash already initialized", __func__));
222 
223 	trunk->hwidth = VLAN_DEF_HWIDTH;
224 	n = 1 << trunk->hwidth;
225 	trunk->hmask = n - 1;
226 	trunk->hash = malloc(sizeof(struct ifvlanhead) * n, M_VLAN, M_WAITOK);
227 	for (i = 0; i < n; i++)
228 		LIST_INIT(&trunk->hash[i]);
229 }
230 
231 static void
232 vlan_freehash(struct ifvlantrunk *trunk)
233 {
234 #ifdef INVARIANTS
235 	int i;
236 
237 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
238 	for (i = 0; i < (1 << trunk->hwidth); i++)
239 		KASSERT(LIST_EMPTY(&trunk->hash[i]),
240 		    ("%s: hash table not empty", __func__));
241 #endif
242 	free(trunk->hash, M_VLAN);
243 	trunk->hash = NULL;
244 	trunk->hwidth = trunk->hmask = 0;
245 }
246 
247 static int
248 vlan_inshash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
249 {
250 	int i, b;
251 	struct ifvlan *ifv2;
252 
253 	TRUNK_LOCK_ASSERT(trunk);
254 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
255 
256 	b = 1 << trunk->hwidth;
257 	i = HASH(ifv->ifv_tag, trunk->hmask);
258 	LIST_FOREACH(ifv2, &trunk->hash[i], ifv_list)
259 		if (ifv->ifv_tag == ifv2->ifv_tag)
260 			return (EEXIST);
261 
262 	/*
263 	 * Grow the hash when the number of vlans exceeds half of the number of
264 	 * hash buckets squared. This will make the average linked-list length
265 	 * buckets/2.
266 	 */
267 	if (trunk->refcnt > (b * b) / 2) {
268 		vlan_growhash(trunk, 1);
269 		i = HASH(ifv->ifv_tag, trunk->hmask);
270 	}
271 	LIST_INSERT_HEAD(&trunk->hash[i], ifv, ifv_list);
272 	trunk->refcnt++;
273 
274 	return (0);
275 }
276 
277 static int
278 vlan_remhash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
279 {
280 	int i, b;
281 	struct ifvlan *ifv2;
282 
283 	TRUNK_LOCK_ASSERT(trunk);
284 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
285 
286 	b = 1 << trunk->hwidth;
287 	i = HASH(ifv->ifv_tag, trunk->hmask);
288 	LIST_FOREACH(ifv2, &trunk->hash[i], ifv_list)
289 		if (ifv2 == ifv) {
290 			trunk->refcnt--;
291 			LIST_REMOVE(ifv2, ifv_list);
292 			if (trunk->refcnt < (b * b) / 2)
293 				vlan_growhash(trunk, -1);
294 			return (0);
295 		}
296 
297 	panic("%s: vlan not found\n", __func__);
298 	return (ENOENT); /*NOTREACHED*/
299 }
300 
301 /*
302  * Grow the hash larger or smaller if memory permits.
303  */
304 static void
305 vlan_growhash(struct ifvlantrunk *trunk, int howmuch)
306 {
307 	struct ifvlan *ifv;
308 	struct ifvlanhead *hash2;
309 	int hwidth2, i, j, n, n2;
310 
311 	TRUNK_LOCK_ASSERT(trunk);
312 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
313 
314 	if (howmuch == 0) {
315 		/* Harmless yet obvious coding error */
316 		printf("%s: howmuch is 0\n", __func__);
317 		return;
318 	}
319 
320 	hwidth2 = trunk->hwidth + howmuch;
321 	n = 1 << trunk->hwidth;
322 	n2 = 1 << hwidth2;
323 	/* Do not shrink the table below the default */
324 	if (hwidth2 < VLAN_DEF_HWIDTH)
325 		return;
326 
327 	/* M_NOWAIT because we're called with trunk mutex held */
328 	hash2 = malloc(sizeof(struct ifvlanhead) * n2, M_VLAN, M_NOWAIT);
329 	if (hash2 == NULL) {
330 		printf("%s: out of memory -- hash size not changed\n",
331 		    __func__);
332 		return;		/* We can live with the old hash table */
333 	}
334 	for (j = 0; j < n2; j++)
335 		LIST_INIT(&hash2[j]);
336 	for (i = 0; i < n; i++)
337 		while ((ifv = LIST_FIRST(&trunk->hash[i])) != NULL) {
338 			LIST_REMOVE(ifv, ifv_list);
339 			j = HASH(ifv->ifv_tag, n2 - 1);
340 			LIST_INSERT_HEAD(&hash2[j], ifv, ifv_list);
341 		}
342 	free(trunk->hash, M_VLAN);
343 	trunk->hash = hash2;
344 	trunk->hwidth = hwidth2;
345 	trunk->hmask = n2 - 1;
346 
347 	if (bootverbose)
348 		if_printf(trunk->parent,
349 		    "VLAN hash table resized from %d to %d buckets\n", n, n2);
350 }
351 
352 static __inline struct ifvlan *
353 vlan_gethash(struct ifvlantrunk *trunk, uint16_t tag)
354 {
355 	struct ifvlan *ifv;
356 
357 	TRUNK_LOCK_RASSERT(trunk);
358 
359 	LIST_FOREACH(ifv, &trunk->hash[HASH(tag, trunk->hmask)], ifv_list)
360 		if (ifv->ifv_tag == tag)
361 			return (ifv);
362 	return (NULL);
363 }
364 
365 #if 0
366 /* Debugging code to view the hashtables. */
367 static void
368 vlan_dumphash(struct ifvlantrunk *trunk)
369 {
370 	int i;
371 	struct ifvlan *ifv;
372 
373 	for (i = 0; i < (1 << trunk->hwidth); i++) {
374 		printf("%d: ", i);
375 		LIST_FOREACH(ifv, &trunk->hash[i], ifv_list)
376 			printf("%s ", ifv->ifv_ifp->if_xname);
377 		printf("\n");
378 	}
379 }
380 #endif /* 0 */
381 #endif /* !VLAN_ARRAY */
382 
383 static void
384 trunk_destroy(struct ifvlantrunk *trunk)
385 {
386 	VLAN_LOCK_ASSERT();
387 
388 	TRUNK_LOCK(trunk);
389 #ifndef VLAN_ARRAY
390 	vlan_freehash(trunk);
391 #endif
392 	trunk->parent->if_vlantrunk = NULL;
393 	TRUNK_UNLOCK(trunk);
394 	TRUNK_LOCK_DESTROY(trunk);
395 	free(trunk, M_VLAN);
396 }
397 
398 /*
399  * Program our multicast filter. What we're actually doing is
400  * programming the multicast filter of the parent. This has the
401  * side effect of causing the parent interface to receive multicast
402  * traffic that it doesn't really want, which ends up being discarded
403  * later by the upper protocol layers. Unfortunately, there's no way
404  * to avoid this: there really is only one physical interface.
405  *
406  * XXX: There is a possible race here if more than one thread is
407  *      modifying the multicast state of the vlan interface at the same time.
408  */
409 static int
410 vlan_setmulti(struct ifnet *ifp)
411 {
412 	struct ifnet		*ifp_p;
413 	struct ifmultiaddr	*ifma, *rifma = NULL;
414 	struct ifvlan		*sc;
415 	struct vlan_mc_entry	*mc;
416 	struct sockaddr_dl	sdl;
417 	int			error;
418 
419 	/*VLAN_LOCK_ASSERT();*/
420 
421 	/* Find the parent. */
422 	sc = ifp->if_softc;
423 	ifp_p = PARENT(sc);
424 
425 	bzero((char *)&sdl, sizeof(sdl));
426 	sdl.sdl_len = sizeof(sdl);
427 	sdl.sdl_family = AF_LINK;
428 	sdl.sdl_index = ifp_p->if_index;
429 	sdl.sdl_type = IFT_ETHER;
430 	sdl.sdl_alen = ETHER_ADDR_LEN;
431 
432 	/* First, remove any existing filter entries. */
433 	while ((mc = SLIST_FIRST(&sc->vlan_mc_listhead)) != NULL) {
434 		bcopy((char *)&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN);
435 		error = if_delmulti(ifp_p, (struct sockaddr *)&sdl);
436 		if (error)
437 			return (error);
438 		SLIST_REMOVE_HEAD(&sc->vlan_mc_listhead, mc_entries);
439 		free(mc, M_VLAN);
440 	}
441 
442 	/* Now program new ones. */
443 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
444 		if (ifma->ifma_addr->sa_family != AF_LINK)
445 			continue;
446 		mc = malloc(sizeof(struct vlan_mc_entry), M_VLAN, M_NOWAIT);
447 		if (mc == NULL)
448 			return (ENOMEM);
449 		bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
450 		    (char *)&mc->mc_addr, ETHER_ADDR_LEN);
451 		SLIST_INSERT_HEAD(&sc->vlan_mc_listhead, mc, mc_entries);
452 		bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
453 		    LLADDR(&sdl), ETHER_ADDR_LEN);
454 		error = if_addmulti(ifp_p, (struct sockaddr *)&sdl, &rifma);
455 		if (error)
456 			return (error);
457 	}
458 
459 	return (0);
460 }
461 
462 /*
463  * A handler for network interface departure events.
464  * Track departure of trunks here so that we don't access invalid
465  * pointers or whatever if a trunk is ripped from under us, e.g.,
466  * by ejecting its hot-plug card.
467  */
468 static void
469 vlan_ifdetach(void *arg __unused, struct ifnet *ifp)
470 {
471 	struct ifvlan *ifv;
472 	int i;
473 
474 	/*
475 	 * Check if it's a trunk interface first of all
476 	 * to avoid needless locking.
477 	 */
478 	if (ifp->if_vlantrunk == NULL)
479 		return;
480 
481 	VLAN_LOCK();
482 	/*
483 	 * OK, it's a trunk.  Loop over and detach all vlan's on it.
484 	 * Check trunk pointer after each vlan_unconfig() as it will
485 	 * free it and set to NULL after the last vlan was detached.
486 	 */
487 #ifdef VLAN_ARRAY
488 	for (i = 0; i < VLAN_ARRAY_SIZE; i++)
489 		if ((ifv = ifp->if_vlantrunk->vlans[i])) {
490 			vlan_unconfig_locked(ifv->ifv_ifp);
491 			if (ifp->if_vlantrunk == NULL)
492 				break;
493 		}
494 #else /* VLAN_ARRAY */
495 restart:
496 	for (i = 0; i < (1 << ifp->if_vlantrunk->hwidth); i++)
497 		if ((ifv = LIST_FIRST(&ifp->if_vlantrunk->hash[i]))) {
498 			vlan_unconfig_locked(ifv->ifv_ifp);
499 			if (ifp->if_vlantrunk)
500 				goto restart;	/* trunk->hwidth can change */
501 			else
502 				break;
503 		}
504 #endif /* VLAN_ARRAY */
505 	/* Trunk should have been destroyed in vlan_unconfig(). */
506 	KASSERT(ifp->if_vlantrunk == NULL, ("%s: purge failed", __func__));
507 	VLAN_UNLOCK();
508 }
509 
510 /*
511  * VLAN support can be loaded as a module.  The only place in the
512  * system that's intimately aware of this is ether_input.  We hook
513  * into this code through vlan_input_p which is defined there and
514  * set here.  Noone else in the system should be aware of this so
515  * we use an explicit reference here.
516  */
517 extern	void (*vlan_input_p)(struct ifnet *, struct mbuf *);
518 
519 /* For if_link_state_change() eyes only... */
520 extern	void (*vlan_link_state_p)(struct ifnet *, int);
521 
522 static int
523 vlan_modevent(module_t mod, int type, void *data)
524 {
525 
526 	switch (type) {
527 	case MOD_LOAD:
528 		ifdetach_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
529 		    vlan_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
530 		if (ifdetach_tag == NULL)
531 			return (ENOMEM);
532 		VLAN_LOCK_INIT();
533 		vlan_input_p = vlan_input;
534 		vlan_link_state_p = vlan_link_state;
535 		vlan_trunk_cap_p = vlan_trunk_capabilities;
536 		if_clone_attach(&vlan_cloner);
537 		if (bootverbose)
538 			printf("vlan: initialized, using "
539 #ifdef VLAN_ARRAY
540 			       "full-size arrays"
541 #else
542 			       "hash tables with chaining"
543 #endif
544 
545 			       "\n");
546 		break;
547 	case MOD_UNLOAD:
548 		if_clone_detach(&vlan_cloner);
549 		EVENTHANDLER_DEREGISTER(ifnet_departure_event, ifdetach_tag);
550 		vlan_input_p = NULL;
551 		vlan_link_state_p = NULL;
552 		vlan_trunk_cap_p = NULL;
553 		VLAN_LOCK_DESTROY();
554 		if (bootverbose)
555 			printf("vlan: unloaded\n");
556 		break;
557 	default:
558 		return (EOPNOTSUPP);
559 	}
560 	return (0);
561 }
562 
563 static moduledata_t vlan_mod = {
564 	"if_vlan",
565 	vlan_modevent,
566 	0
567 };
568 
569 DECLARE_MODULE(if_vlan, vlan_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
570 MODULE_VERSION(if_vlan, 3);
571 MODULE_DEPEND(if_vlan, miibus, 1, 1, 1);
572 
573 static struct ifnet *
574 vlan_clone_match_ethertag(struct if_clone *ifc, const char *name, int *tag)
575 {
576 	const char *cp;
577 	struct ifnet *ifp;
578 	int t = 0;
579 
580 	/* Check for <etherif>.<vlan> style interface names. */
581 	IFNET_RLOCK();
582 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
583 		if (ifp->if_type != IFT_ETHER)
584 			continue;
585 		if (strncmp(ifp->if_xname, name, strlen(ifp->if_xname)) != 0)
586 			continue;
587 		cp = name + strlen(ifp->if_xname);
588 		if (*cp != '.')
589 			continue;
590 		for(; *cp != '\0'; cp++) {
591 			if (*cp < '0' || *cp > '9')
592 				continue;
593 			t = (t * 10) + (*cp - '0');
594 		}
595 		if (tag != NULL)
596 			*tag = t;
597 		break;
598 	}
599 	IFNET_RUNLOCK();
600 
601 	return (ifp);
602 }
603 
604 static int
605 vlan_clone_match(struct if_clone *ifc, const char *name)
606 {
607 	const char *cp;
608 
609 	if (vlan_clone_match_ethertag(ifc, name, NULL) != NULL)
610 		return (1);
611 
612 	if (strncmp(VLANNAME, name, strlen(VLANNAME)) != 0)
613 		return (0);
614 	for (cp = name + 4; *cp != '\0'; cp++) {
615 		if (*cp < '0' || *cp > '9')
616 			return (0);
617 	}
618 
619 	return (1);
620 }
621 
622 static int
623 vlan_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
624 {
625 	char *dp;
626 	int wildcard;
627 	int unit;
628 	int error;
629 	int tag;
630 	int ethertag;
631 	struct ifvlan *ifv;
632 	struct ifnet *ifp;
633 	struct ifnet *p;
634 	struct vlanreq vlr;
635 	static const u_char eaddr[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */
636 
637 	/*
638 	 * There are 3 (ugh) ways to specify the cloned device:
639 	 * o pass a parameter block with the clone request.
640 	 * o specify parameters in the text of the clone device name
641 	 * o specify no parameters and get an unattached device that
642 	 *   must be configured separately.
643 	 * The first technique is preferred; the latter two are
644 	 * supported for backwards compatibilty.
645 	 */
646 	if (params) {
647 		error = copyin(params, &vlr, sizeof(vlr));
648 		if (error)
649 			return error;
650 		p = ifunit(vlr.vlr_parent);
651 		if (p == NULL)
652 			return ENXIO;
653 		/*
654 		 * Don't let the caller set up a VLAN tag with
655 		 * anything except VLID bits.
656 		 */
657 		if (vlr.vlr_tag & ~EVL_VLID_MASK)
658 			return (EINVAL);
659 		error = ifc_name2unit(name, &unit);
660 		if (error != 0)
661 			return (error);
662 
663 		ethertag = 1;
664 		tag = vlr.vlr_tag;
665 		wildcard = (unit < 0);
666 	} else if ((p = vlan_clone_match_ethertag(ifc, name, &tag)) != NULL) {
667 		ethertag = 1;
668 		unit = -1;
669 		wildcard = 0;
670 
671 		/*
672 		 * Don't let the caller set up a VLAN tag with
673 		 * anything except VLID bits.
674 		 */
675 		if (tag & ~EVL_VLID_MASK)
676 			return (EINVAL);
677 	} else {
678 		ethertag = 0;
679 
680 		error = ifc_name2unit(name, &unit);
681 		if (error != 0)
682 			return (error);
683 
684 		wildcard = (unit < 0);
685 	}
686 
687 	error = ifc_alloc_unit(ifc, &unit);
688 	if (error != 0)
689 		return (error);
690 
691 	/* In the wildcard case, we need to update the name. */
692 	if (wildcard) {
693 		for (dp = name; *dp != '\0'; dp++);
694 		if (snprintf(dp, len - (dp-name), "%d", unit) >
695 		    len - (dp-name) - 1) {
696 			panic("%s: interface name too long", __func__);
697 		}
698 	}
699 
700 	ifv = malloc(sizeof(struct ifvlan), M_VLAN, M_WAITOK | M_ZERO);
701 	ifp = ifv->ifv_ifp = if_alloc(IFT_ETHER);
702 	if (ifp == NULL) {
703 		ifc_free_unit(ifc, unit);
704 		free(ifv, M_VLAN);
705 		return (ENOSPC);
706 	}
707 	SLIST_INIT(&ifv->vlan_mc_listhead);
708 
709 	ifp->if_softc = ifv;
710 	/*
711 	 * Set the name manually rather than using if_initname because
712 	 * we don't conform to the default naming convention for interfaces.
713 	 */
714 	strlcpy(ifp->if_xname, name, IFNAMSIZ);
715 	ifp->if_dname = ifc->ifc_name;
716 	ifp->if_dunit = unit;
717 	/* NB: flags are not set here */
718 	ifp->if_linkmib = &ifv->ifv_mib;
719 	ifp->if_linkmiblen = sizeof(ifv->ifv_mib);
720 	/* NB: mtu is not set here */
721 
722 	ifp->if_init = vlan_init;
723 	ifp->if_start = vlan_start;
724 	ifp->if_ioctl = vlan_ioctl;
725 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
726 	ifp->if_flags = VLAN_IFFLAGS;
727 	ether_ifattach(ifp, eaddr);
728 	/* Now undo some of the damage... */
729 	ifp->if_baudrate = 0;
730 	ifp->if_type = IFT_L2VLAN;
731 	ifp->if_hdrlen = ETHER_VLAN_ENCAP_LEN;
732 
733 	if (ethertag) {
734 		error = vlan_config(ifv, p, tag);
735 		if (error != 0) {
736 			/*
737 			 * Since we've partialy failed, we need to back
738 			 * out all the way, otherwise userland could get
739 			 * confused.  Thus, we destroy the interface.
740 			 */
741 			ether_ifdetach(ifp);
742 			vlan_unconfig(ifp);
743 			if_free_type(ifp, IFT_ETHER);
744 			free(ifv, M_VLAN);
745 
746 			return (error);
747 		}
748 
749 		/* Update flags on the parent, if necessary. */
750 		vlan_setflags(ifp, 1);
751 	}
752 
753 	return (0);
754 }
755 
756 static int
757 vlan_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
758 {
759 	struct ifvlan *ifv = ifp->if_softc;
760 	int unit = ifp->if_dunit;
761 
762 	ether_ifdetach(ifp);	/* first, remove it from system-wide lists */
763 	vlan_unconfig(ifp);	/* now it can be unconfigured and freed */
764 	if_free_type(ifp, IFT_ETHER);
765 	free(ifv, M_VLAN);
766 	ifc_free_unit(ifc, unit);
767 
768 	return (0);
769 }
770 
771 /*
772  * The ifp->if_init entry point for vlan(4) is a no-op.
773  */
774 static void
775 vlan_init(void *foo __unused)
776 {
777 }
778 
779 /*
780  * The if_start method for vlan(4) interface. It doesn't
781  * raises the IFF_DRV_OACTIVE flag, since it is called
782  * only from IFQ_HANDOFF() macro in ether_output_frame().
783  * If the interface queue is full, and vlan_start() is
784  * not called, the queue would never get emptied and
785  * interface would stall forever.
786  */
787 static void
788 vlan_start(struct ifnet *ifp)
789 {
790 	struct ifvlan *ifv;
791 	struct ifnet *p;
792 	struct mbuf *m;
793 	int error;
794 
795 	ifv = ifp->if_softc;
796 	p = PARENT(ifv);
797 
798 	for (;;) {
799 		IF_DEQUEUE(&ifp->if_snd, m);
800 		if (m == NULL)
801 			break;
802 		BPF_MTAP(ifp, m);
803 
804 		/*
805 		 * Do not run parent's if_start() if the parent is not up,
806 		 * or parent's driver will cause a system crash.
807 		 */
808 		if (!UP_AND_RUNNING(p)) {
809 			m_freem(m);
810 			ifp->if_collisions++;
811 			continue;
812 		}
813 
814 		/*
815 		 * Pad the frame to the minimum size allowed if told to.
816 		 * This option is in accord with IEEE Std 802.1Q, 2003 Ed.,
817 		 * paragraph C.4.4.3.b.  It can help to work around buggy
818 		 * bridges that violate paragraph C.4.4.3.a from the same
819 		 * document, i.e., fail to pad short frames after untagging.
820 		 * E.g., a tagged frame 66 bytes long (incl. FCS) is OK, but
821 		 * untagging it will produce a 62-byte frame, which is a runt
822 		 * and requires padding.  There are VLAN-enabled network
823 		 * devices that just discard such runts instead or mishandle
824 		 * them somehow.
825 		 */
826 		if (soft_pad) {
827 			static char pad[8];	/* just zeros */
828 			int n;
829 
830 			for (n = ETHERMIN + ETHER_HDR_LEN - m->m_pkthdr.len;
831 			     n > 0; n -= sizeof(pad))
832 				if (!m_append(m, min(n, sizeof(pad)), pad))
833 					break;
834 
835 			if (n > 0) {
836 				if_printf(ifp, "cannot pad short frame\n");
837 				ifp->if_oerrors++;
838 				m_freem(m);
839 				continue;
840 			}
841 		}
842 
843 		/*
844 		 * If underlying interface can do VLAN tag insertion itself,
845 		 * just pass the packet along. However, we need some way to
846 		 * tell the interface where the packet came from so that it
847 		 * knows how to find the VLAN tag to use, so we attach a
848 		 * packet tag that holds it.
849 		 */
850 		if (p->if_capenable & IFCAP_VLAN_HWTAGGING) {
851 			m->m_pkthdr.ether_vtag = ifv->ifv_tag;
852 			m->m_flags |= M_VLANTAG;
853 		} else {
854 			m = ether_vlanencap(m, ifv->ifv_tag);
855 			if (m == NULL) {
856 				if_printf(ifp,
857 				    "unable to prepend VLAN header\n");
858 				ifp->if_oerrors++;
859 				continue;
860 			}
861 		}
862 
863 		/*
864 		 * Send it, precisely as ether_output() would have.
865 		 * We are already running at splimp.
866 		 */
867 		IFQ_HANDOFF(p, m, error);
868 		if (!error)
869 			ifp->if_opackets++;
870 		else
871 			ifp->if_oerrors++;
872 	}
873 }
874 
875 static void
876 vlan_input(struct ifnet *ifp, struct mbuf *m)
877 {
878 	struct ifvlantrunk *trunk = ifp->if_vlantrunk;
879 	struct ifvlan *ifv;
880 	uint16_t tag;
881 
882 	KASSERT(trunk != NULL, ("%s: no trunk", __func__));
883 
884 	if (m->m_flags & M_VLANTAG) {
885 		/*
886 		 * Packet is tagged, but m contains a normal
887 		 * Ethernet frame; the tag is stored out-of-band.
888 		 */
889 		tag = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
890 		m->m_flags &= ~M_VLANTAG;
891 	} else {
892 		struct ether_vlan_header *evl;
893 
894 		/*
895 		 * Packet is tagged in-band as specified by 802.1q.
896 		 */
897 		switch (ifp->if_type) {
898 		case IFT_ETHER:
899 			if (m->m_len < sizeof(*evl) &&
900 			    (m = m_pullup(m, sizeof(*evl))) == NULL) {
901 				if_printf(ifp, "cannot pullup VLAN header\n");
902 				return;
903 			}
904 			evl = mtod(m, struct ether_vlan_header *);
905 			tag = EVL_VLANOFTAG(ntohs(evl->evl_tag));
906 
907 			/*
908 			 * Remove the 802.1q header by copying the Ethernet
909 			 * addresses over it and adjusting the beginning of
910 			 * the data in the mbuf.  The encapsulated Ethernet
911 			 * type field is already in place.
912 			 */
913 			bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN,
914 			      ETHER_HDR_LEN - ETHER_TYPE_LEN);
915 			m_adj(m, ETHER_VLAN_ENCAP_LEN);
916 			break;
917 
918 		default:
919 #ifdef INVARIANTS
920 			panic("%s: %s has unsupported if_type %u",
921 			      __func__, ifp->if_xname, ifp->if_type);
922 #endif
923 			m_freem(m);
924 			ifp->if_noproto++;
925 			return;
926 		}
927 	}
928 
929 	TRUNK_RLOCK(trunk);
930 #ifdef VLAN_ARRAY
931 	ifv = trunk->vlans[tag];
932 #else
933 	ifv = vlan_gethash(trunk, tag);
934 #endif
935 	if (ifv == NULL || !UP_AND_RUNNING(ifv->ifv_ifp)) {
936 		TRUNK_RUNLOCK(trunk);
937 		m_freem(m);
938 		ifp->if_noproto++;
939 		return;
940 	}
941 	TRUNK_RUNLOCK(trunk);
942 
943 	m->m_pkthdr.rcvif = ifv->ifv_ifp;
944 	ifv->ifv_ifp->if_ipackets++;
945 
946 	/* Pass it back through the parent's input routine. */
947 	(*ifp->if_input)(ifv->ifv_ifp, m);
948 }
949 
950 static int
951 vlan_config(struct ifvlan *ifv, struct ifnet *p, uint16_t tag)
952 {
953 	struct ifvlantrunk *trunk;
954 	struct ifnet *ifp;
955 	int error = 0;
956 
957 	/* VID numbers 0x0 and 0xFFF are reserved */
958 	if (tag == 0 || tag == 0xFFF)
959 		return (EINVAL);
960 	if (p->if_type != IFT_ETHER)
961 		return (EPROTONOSUPPORT);
962 	if ((p->if_flags & VLAN_IFFLAGS) != VLAN_IFFLAGS)
963 		return (EPROTONOSUPPORT);
964 	if (ifv->ifv_trunk)
965 		return (EBUSY);
966 
967 	if (p->if_vlantrunk == NULL) {
968 		trunk = malloc(sizeof(struct ifvlantrunk),
969 		    M_VLAN, M_WAITOK | M_ZERO);
970 #ifndef VLAN_ARRAY
971 		vlan_inithash(trunk);
972 #endif
973 		VLAN_LOCK();
974 		if (p->if_vlantrunk != NULL) {
975 			/* A race that that is very unlikely to be hit. */
976 #ifndef VLAN_ARRAY
977 			vlan_freehash(trunk);
978 #endif
979 			free(trunk, M_VLAN);
980 			goto exists;
981 		}
982 		TRUNK_LOCK_INIT(trunk);
983 		TRUNK_LOCK(trunk);
984 		p->if_vlantrunk = trunk;
985 		trunk->parent = p;
986 	} else {
987 		VLAN_LOCK();
988 exists:
989 		trunk = p->if_vlantrunk;
990 		TRUNK_LOCK(trunk);
991 	}
992 
993 	ifv->ifv_tag = tag;	/* must set this before vlan_inshash() */
994 #ifdef VLAN_ARRAY
995 	if (trunk->vlans[tag] != NULL) {
996 		error = EEXIST;
997 		goto done;
998 	}
999 	trunk->vlans[tag] = ifv;
1000 	trunk->refcnt++;
1001 #else
1002 	error = vlan_inshash(trunk, ifv);
1003 	if (error)
1004 		goto done;
1005 #endif
1006 	ifv->ifv_proto = ETHERTYPE_VLAN;
1007 	ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN;
1008 	ifv->ifv_mintu = ETHERMIN;
1009 	ifv->ifv_pflags = 0;
1010 
1011 	/*
1012 	 * If the parent supports the VLAN_MTU capability,
1013 	 * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames,
1014 	 * use it.
1015 	 */
1016 	if (p->if_capenable & IFCAP_VLAN_MTU) {
1017 		/*
1018 		 * No need to fudge the MTU since the parent can
1019 		 * handle extended frames.
1020 		 */
1021 		ifv->ifv_mtufudge = 0;
1022 	} else {
1023 		/*
1024 		 * Fudge the MTU by the encapsulation size.  This
1025 		 * makes us incompatible with strictly compliant
1026 		 * 802.1Q implementations, but allows us to use
1027 		 * the feature with other NetBSD implementations,
1028 		 * which might still be useful.
1029 		 */
1030 		ifv->ifv_mtufudge = ifv->ifv_encaplen;
1031 	}
1032 
1033 	ifv->ifv_trunk = trunk;
1034 	ifp = ifv->ifv_ifp;
1035 	ifp->if_mtu = p->if_mtu - ifv->ifv_mtufudge;
1036 	ifp->if_baudrate = p->if_baudrate;
1037 	/*
1038 	 * Copy only a selected subset of flags from the parent.
1039 	 * Other flags are none of our business.
1040 	 */
1041 #define VLAN_COPY_FLAGS (IFF_SIMPLEX)
1042 	ifp->if_flags &= ~VLAN_COPY_FLAGS;
1043 	ifp->if_flags |= p->if_flags & VLAN_COPY_FLAGS;
1044 #undef VLAN_COPY_FLAGS
1045 
1046 	ifp->if_link_state = p->if_link_state;
1047 
1048 	vlan_capabilities(ifv);
1049 
1050 	/*
1051 	 * Set up our ``Ethernet address'' to reflect the underlying
1052 	 * physical interface's.
1053 	 */
1054 	bcopy(IF_LLADDR(p), IF_LLADDR(ifp), ETHER_ADDR_LEN);
1055 
1056 	/*
1057 	 * Configure multicast addresses that may already be
1058 	 * joined on the vlan device.
1059 	 */
1060 	(void)vlan_setmulti(ifp); /* XXX: VLAN lock held */
1061 
1062 	/* We are ready for operation now. */
1063 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1064 done:
1065 	TRUNK_UNLOCK(trunk);
1066 	if (error == 0)
1067 		EVENTHANDLER_INVOKE(vlan_config, p, ifv->ifv_tag);
1068 	VLAN_UNLOCK();
1069 
1070 	return (error);
1071 }
1072 
1073 static int
1074 vlan_unconfig(struct ifnet *ifp)
1075 {
1076 	int ret;
1077 
1078 	VLAN_LOCK();
1079 	ret = vlan_unconfig_locked(ifp);
1080 	VLAN_UNLOCK();
1081 	return (ret);
1082 }
1083 
1084 static int
1085 vlan_unconfig_locked(struct ifnet *ifp)
1086 {
1087 	struct ifvlantrunk *trunk;
1088 	struct vlan_mc_entry *mc;
1089 	struct ifvlan *ifv;
1090 	struct ifnet  *parent;
1091 	int error;
1092 
1093 	VLAN_LOCK_ASSERT();
1094 
1095 	ifv = ifp->if_softc;
1096 	trunk = ifv->ifv_trunk;
1097 	parent = PARENT(ifv);
1098 
1099 	if (trunk) {
1100 		struct sockaddr_dl sdl;
1101 		struct ifnet *p = trunk->parent;
1102 
1103 		TRUNK_LOCK(trunk);
1104 
1105 		/*
1106 		 * Since the interface is being unconfigured, we need to
1107 		 * empty the list of multicast groups that we may have joined
1108 		 * while we were alive from the parent's list.
1109 		 */
1110 		bzero((char *)&sdl, sizeof(sdl));
1111 		sdl.sdl_len = sizeof(sdl);
1112 		sdl.sdl_family = AF_LINK;
1113 		sdl.sdl_index = p->if_index;
1114 		sdl.sdl_type = IFT_ETHER;
1115 		sdl.sdl_alen = ETHER_ADDR_LEN;
1116 
1117 		while ((mc = SLIST_FIRST(&ifv->vlan_mc_listhead)) != NULL) {
1118 			bcopy((char *)&mc->mc_addr, LLADDR(&sdl),
1119 			    ETHER_ADDR_LEN);
1120 			error = if_delmulti(p, (struct sockaddr *)&sdl);
1121 			if (error)
1122 				return (error);
1123 			SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
1124 			free(mc, M_VLAN);
1125 		}
1126 
1127 		vlan_setflags(ifp, 0); /* clear special flags on parent */
1128 #ifdef VLAN_ARRAY
1129 		trunk->vlans[ifv->ifv_tag] = NULL;
1130 		trunk->refcnt--;
1131 #else
1132 		vlan_remhash(trunk, ifv);
1133 #endif
1134 		ifv->ifv_trunk = NULL;
1135 
1136 		/*
1137 		 * Check if we were the last.
1138 		 */
1139 		if (trunk->refcnt == 0) {
1140 			trunk->parent->if_vlantrunk = NULL;
1141 			/*
1142 			 * XXXGL: If some ithread has already entered
1143 			 * vlan_input() and is now blocked on the trunk
1144 			 * lock, then it should preempt us right after
1145 			 * unlock and finish its work. Then we will acquire
1146 			 * lock again in trunk_destroy().
1147 			 */
1148 			TRUNK_UNLOCK(trunk);
1149 			trunk_destroy(trunk);
1150 		} else
1151 			TRUNK_UNLOCK(trunk);
1152 	}
1153 
1154 	/* Disconnect from parent. */
1155 	if (ifv->ifv_pflags)
1156 		if_printf(ifp, "%s: ifv_pflags unclean\n", __func__);
1157 	ifp->if_mtu = ETHERMTU;
1158 	ifp->if_link_state = LINK_STATE_UNKNOWN;
1159 	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1160 
1161 	EVENTHANDLER_INVOKE(vlan_unconfig, parent, ifv->ifv_tag);
1162 
1163 	return (0);
1164 }
1165 
1166 /* Handle a reference counted flag that should be set on the parent as well */
1167 static int
1168 vlan_setflag(struct ifnet *ifp, int flag, int status,
1169 	     int (*func)(struct ifnet *, int))
1170 {
1171 	struct ifvlan *ifv;
1172 	int error;
1173 
1174 	/* XXX VLAN_LOCK_ASSERT(); */
1175 
1176 	ifv = ifp->if_softc;
1177 	status = status ? (ifp->if_flags & flag) : 0;
1178 	/* Now "status" contains the flag value or 0 */
1179 
1180 	/*
1181 	 * See if recorded parent's status is different from what
1182 	 * we want it to be.  If it is, flip it.  We record parent's
1183 	 * status in ifv_pflags so that we won't clear parent's flag
1184 	 * we haven't set.  In fact, we don't clear or set parent's
1185 	 * flags directly, but get or release references to them.
1186 	 * That's why we can be sure that recorded flags still are
1187 	 * in accord with actual parent's flags.
1188 	 */
1189 	if (status != (ifv->ifv_pflags & flag)) {
1190 		error = (*func)(PARENT(ifv), status);
1191 		if (error)
1192 			return (error);
1193 		ifv->ifv_pflags &= ~flag;
1194 		ifv->ifv_pflags |= status;
1195 	}
1196 	return (0);
1197 }
1198 
1199 /*
1200  * Handle IFF_* flags that require certain changes on the parent:
1201  * if "status" is true, update parent's flags respective to our if_flags;
1202  * if "status" is false, forcedly clear the flags set on parent.
1203  */
1204 static int
1205 vlan_setflags(struct ifnet *ifp, int status)
1206 {
1207 	int error, i;
1208 
1209 	for (i = 0; vlan_pflags[i].flag; i++) {
1210 		error = vlan_setflag(ifp, vlan_pflags[i].flag,
1211 				     status, vlan_pflags[i].func);
1212 		if (error)
1213 			return (error);
1214 	}
1215 	return (0);
1216 }
1217 
1218 /* Inform all vlans that their parent has changed link state */
1219 static void
1220 vlan_link_state(struct ifnet *ifp, int link)
1221 {
1222 	struct ifvlantrunk *trunk = ifp->if_vlantrunk;
1223 	struct ifvlan *ifv;
1224 	int i;
1225 
1226 	TRUNK_LOCK(trunk);
1227 #ifdef VLAN_ARRAY
1228 	for (i = 0; i < VLAN_ARRAY_SIZE; i++)
1229 		if (trunk->vlans[i] != NULL) {
1230 			ifv = trunk->vlans[i];
1231 #else
1232 	for (i = 0; i < (1 << trunk->hwidth); i++)
1233 		LIST_FOREACH(ifv, &trunk->hash[i], ifv_list) {
1234 #endif
1235 			ifv->ifv_ifp->if_baudrate = trunk->parent->if_baudrate;
1236 			if_link_state_change(ifv->ifv_ifp,
1237 			    trunk->parent->if_link_state);
1238 		}
1239 	TRUNK_UNLOCK(trunk);
1240 }
1241 
1242 static void
1243 vlan_capabilities(struct ifvlan *ifv)
1244 {
1245 	struct ifnet *p = PARENT(ifv);
1246 	struct ifnet *ifp = ifv->ifv_ifp;
1247 
1248 	TRUNK_LOCK_ASSERT(TRUNK(ifv));
1249 
1250 	/*
1251 	 * If the parent interface can do checksum offloading
1252 	 * on VLANs, then propagate its hardware-assisted
1253 	 * checksumming flags. Also assert that checksum
1254 	 * offloading requires hardware VLAN tagging.
1255 	 */
1256 	if (p->if_capabilities & IFCAP_VLAN_HWCSUM)
1257 		ifp->if_capabilities = p->if_capabilities & IFCAP_HWCSUM;
1258 
1259 	if (p->if_capenable & IFCAP_VLAN_HWCSUM &&
1260 	    p->if_capenable & IFCAP_VLAN_HWTAGGING) {
1261 		ifp->if_capenable = p->if_capenable & IFCAP_HWCSUM;
1262 		ifp->if_hwassist = p->if_hwassist;
1263 	} else {
1264 		ifp->if_capenable = 0;
1265 		ifp->if_hwassist = 0;
1266 	}
1267 }
1268 
1269 static void
1270 vlan_trunk_capabilities(struct ifnet *ifp)
1271 {
1272 	struct ifvlantrunk *trunk = ifp->if_vlantrunk;
1273 	struct ifvlan *ifv;
1274 	int i;
1275 
1276 	TRUNK_LOCK(trunk);
1277 #ifdef VLAN_ARRAY
1278 	for (i = 0; i < VLAN_ARRAY_SIZE; i++)
1279 		if (trunk->vlans[i] != NULL) {
1280 			ifv = trunk->vlans[i];
1281 #else
1282 	for (i = 0; i < (1 << trunk->hwidth); i++) {
1283 		LIST_FOREACH(ifv, &trunk->hash[i], ifv_list)
1284 #endif
1285 			vlan_capabilities(ifv);
1286 	}
1287 	TRUNK_UNLOCK(trunk);
1288 }
1289 
1290 static int
1291 vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1292 {
1293 	struct ifaddr *ifa;
1294 	struct ifnet *p;
1295 	struct ifreq *ifr;
1296 	struct ifvlan *ifv;
1297 	struct vlanreq vlr;
1298 	int error = 0;
1299 
1300 	ifr = (struct ifreq *)data;
1301 	ifa = (struct ifaddr *)data;
1302 	ifv = ifp->if_softc;
1303 
1304 	switch (cmd) {
1305 	case SIOCGIFMEDIA:
1306 		VLAN_LOCK();
1307 		if (TRUNK(ifv) != NULL) {
1308 			error = (*PARENT(ifv)->if_ioctl)(PARENT(ifv),
1309 					SIOCGIFMEDIA, data);
1310 			VLAN_UNLOCK();
1311 			/* Limit the result to the parent's current config. */
1312 			if (error == 0) {
1313 				struct ifmediareq *ifmr;
1314 
1315 				ifmr = (struct ifmediareq *)data;
1316 				if (ifmr->ifm_count >= 1 && ifmr->ifm_ulist) {
1317 					ifmr->ifm_count = 1;
1318 					error = copyout(&ifmr->ifm_current,
1319 						ifmr->ifm_ulist,
1320 						sizeof(int));
1321 				}
1322 			}
1323 		} else {
1324 			VLAN_UNLOCK();
1325 			error = EINVAL;
1326 		}
1327 		break;
1328 
1329 	case SIOCSIFMEDIA:
1330 		error = EINVAL;
1331 		break;
1332 
1333 	case SIOCSIFMTU:
1334 		/*
1335 		 * Set the interface MTU.
1336 		 */
1337 		VLAN_LOCK();
1338 		if (TRUNK(ifv) != NULL) {
1339 			if (ifr->ifr_mtu >
1340 			     (PARENT(ifv)->if_mtu - ifv->ifv_mtufudge) ||
1341 			    ifr->ifr_mtu <
1342 			     (ifv->ifv_mintu - ifv->ifv_mtufudge))
1343 				error = EINVAL;
1344 			else
1345 				ifp->if_mtu = ifr->ifr_mtu;
1346 		} else
1347 			error = EINVAL;
1348 		VLAN_UNLOCK();
1349 		break;
1350 
1351 	case SIOCSETVLAN:
1352 		error = copyin(ifr->ifr_data, &vlr, sizeof(vlr));
1353 		if (error)
1354 			break;
1355 		if (vlr.vlr_parent[0] == '\0') {
1356 			vlan_unconfig(ifp);
1357 			break;
1358 		}
1359 		p = ifunit(vlr.vlr_parent);
1360 		if (p == 0) {
1361 			error = ENOENT;
1362 			break;
1363 		}
1364 		/*
1365 		 * Don't let the caller set up a VLAN tag with
1366 		 * anything except VLID bits.
1367 		 */
1368 		if (vlr.vlr_tag & ~EVL_VLID_MASK) {
1369 			error = EINVAL;
1370 			break;
1371 		}
1372 		error = vlan_config(ifv, p, vlr.vlr_tag);
1373 		if (error)
1374 			break;
1375 
1376 		/* Update flags on the parent, if necessary. */
1377 		vlan_setflags(ifp, 1);
1378 		break;
1379 
1380 	case SIOCGETVLAN:
1381 		bzero(&vlr, sizeof(vlr));
1382 		VLAN_LOCK();
1383 		if (TRUNK(ifv) != NULL) {
1384 			strlcpy(vlr.vlr_parent, PARENT(ifv)->if_xname,
1385 			    sizeof(vlr.vlr_parent));
1386 			vlr.vlr_tag = ifv->ifv_tag;
1387 		}
1388 		VLAN_UNLOCK();
1389 		error = copyout(&vlr, ifr->ifr_data, sizeof(vlr));
1390 		break;
1391 
1392 	case SIOCSIFFLAGS:
1393 		/*
1394 		 * We should propagate selected flags to the parent,
1395 		 * e.g., promiscuous mode.
1396 		 */
1397 		if (TRUNK(ifv) != NULL)
1398 			error = vlan_setflags(ifp, 1);
1399 		break;
1400 
1401 	case SIOCADDMULTI:
1402 	case SIOCDELMULTI:
1403 		/*
1404 		 * If we don't have a parent, just remember the membership for
1405 		 * when we do.
1406 		 */
1407 		if (TRUNK(ifv) != NULL)
1408 			error = vlan_setmulti(ifp);
1409 		break;
1410 
1411 	default:
1412 		error = ether_ioctl(ifp, cmd, data);
1413 	}
1414 
1415 	return (error);
1416 }
1417