xref: /freebsd/sys/net/if_vlan.c (revision acd3428b7d3e94cef0e1881c868cb4b131d4ff41)
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 #include "opt_vlan.h"
46 
47 #include <sys/param.h>
48 #include <sys/kernel.h>
49 #include <sys/lock.h>
50 #include <sys/malloc.h>
51 #include <sys/mbuf.h>
52 #include <sys/module.h>
53 #include <sys/rwlock.h>
54 #include <sys/queue.h>
55 #include <sys/socket.h>
56 #include <sys/sockio.h>
57 #include <sys/sysctl.h>
58 #include <sys/systm.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_arp.h>
65 #include <net/if_dl.h>
66 #include <net/if_types.h>
67 #include <net/if_vlan_var.h>
68 
69 #ifdef INET
70 #include <netinet/in.h>
71 #include <netinet/if_ether.h>
72 #endif
73 
74 #define VLANNAME	"vlan"
75 #define	VLAN_DEF_HWIDTH	4
76 #define	VLAN_IFFLAGS	(IFF_BROADCAST | IFF_MULTICAST)
77 
78 LIST_HEAD(ifvlanhead, ifvlan);
79 
80 struct ifvlantrunk {
81 	struct	ifnet   *parent;	/* parent interface of this trunk */
82 	struct	rwlock	rw;
83 #ifdef VLAN_ARRAY
84 #define	VLAN_ARRAY_SIZE	(EVL_VLID_MASK + 1)
85 	struct	ifvlan	*vlans[VLAN_ARRAY_SIZE]; /* static table */
86 #else
87 	struct	ifvlanhead *hash;	/* dynamic hash-list table */
88 	uint16_t	hmask;
89 	uint16_t	hwidth;
90 #endif
91 	int		refcnt;
92 	LIST_ENTRY(ifvlantrunk) trunk_entry;
93 };
94 static LIST_HEAD(, ifvlantrunk) trunk_list;
95 
96 struct vlan_mc_entry {
97 	struct ether_addr		mc_addr;
98 	SLIST_ENTRY(vlan_mc_entry)	mc_entries;
99 };
100 
101 struct	ifvlan {
102 	struct	ifvlantrunk *ifv_trunk;
103 	struct	ifnet *ifv_ifp;
104 #define	TRUNK(ifv)	((ifv)->ifv_trunk)
105 #define	PARENT(ifv)	((ifv)->ifv_trunk->parent)
106 	int	ifv_pflags;	/* special flags we have set on parent */
107 	struct	ifv_linkmib {
108 		int	ifvm_encaplen;	/* encapsulation length */
109 		int	ifvm_mtufudge;	/* MTU fudged by this much */
110 		int	ifvm_mintu;	/* min transmission unit */
111 		uint16_t ifvm_proto;	/* encapsulation ethertype */
112 		uint16_t ifvm_tag;	/* tag to apply on packets leaving if */
113 	}	ifv_mib;
114 	SLIST_HEAD(, vlan_mc_entry) vlan_mc_listhead;
115 	LIST_ENTRY(ifvlan) ifv_list;
116 };
117 #define	ifv_proto	ifv_mib.ifvm_proto
118 #define	ifv_tag		ifv_mib.ifvm_tag
119 #define	ifv_encaplen	ifv_mib.ifvm_encaplen
120 #define	ifv_mtufudge	ifv_mib.ifvm_mtufudge
121 #define	ifv_mintu	ifv_mib.ifvm_mintu
122 
123 /* Special flags we should propagate to parent. */
124 static struct {
125 	int flag;
126 	int (*func)(struct ifnet *, int);
127 } vlan_pflags[] = {
128 	{IFF_PROMISC, ifpromisc},
129 	{IFF_ALLMULTI, if_allmulti},
130 	{0, NULL}
131 };
132 
133 SYSCTL_DECL(_net_link);
134 SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN");
135 SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency");
136 
137 static int soft_pad = 0;
138 SYSCTL_INT(_net_link_vlan, OID_AUTO, soft_pad, CTLFLAG_RW, &soft_pad, 0,
139 	   "pad short frames before tagging");
140 
141 static MALLOC_DEFINE(M_VLAN, VLANNAME, "802.1Q Virtual LAN Interface");
142 
143 static eventhandler_tag ifdetach_tag;
144 
145 /*
146  * We have a global mutex, that is used to serialize configuration
147  * changes and isn't used in normal packet delivery.
148  *
149  * We also have a per-trunk rwlock, that is locked shared on packet
150  * processing and exclusive when configuration is changed.
151  *
152  * The VLAN_ARRAY substitutes the dynamic hash with a static array
153  * with 4096 entries. In theory this can give a boost in processing,
154  * however on practice it does not. Probably this is because array
155  * is too big to fit into CPU cache.
156  */
157 static struct mtx ifv_mtx;
158 #define	VLAN_LOCK_INIT()	mtx_init(&ifv_mtx, "vlan_global", NULL, MTX_DEF)
159 #define	VLAN_LOCK_DESTROY()	mtx_destroy(&ifv_mtx)
160 #define	VLAN_LOCK_ASSERT()	mtx_assert(&ifv_mtx, MA_OWNED)
161 #define	VLAN_LOCK()		mtx_lock(&ifv_mtx)
162 #define	VLAN_UNLOCK()		mtx_unlock(&ifv_mtx)
163 #define	TRUNK_LOCK_INIT(trunk)	rw_init(&(trunk)->rw, VLANNAME)
164 #define	TRUNK_LOCK_DESTROY(trunk) rw_destroy(&(trunk)->rw)
165 #define	TRUNK_LOCK(trunk)	rw_wlock(&(trunk)->rw)
166 #define	TRUNK_UNLOCK(trunk)	rw_wunlock(&(trunk)->rw)
167 #define	TRUNK_LOCK_ASSERT(trunk) rw_assert(&(trunk)->rw, RA_WLOCKED)
168 #define	TRUNK_RLOCK(trunk)	rw_rlock(&(trunk)->rw)
169 #define	TRUNK_RUNLOCK(trunk)	rw_runlock(&(trunk)->rw)
170 #define	TRUNK_LOCK_RASSERT(trunk) rw_assert(&(trunk)->rw, RA_RLOCKED)
171 
172 #ifndef VLAN_ARRAY
173 static	void vlan_inithash(struct ifvlantrunk *trunk);
174 static	void vlan_freehash(struct ifvlantrunk *trunk);
175 static	int vlan_inshash(struct ifvlantrunk *trunk, struct ifvlan *ifv);
176 static	int vlan_remhash(struct ifvlantrunk *trunk, struct ifvlan *ifv);
177 static	void vlan_growhash(struct ifvlantrunk *trunk, int howmuch);
178 static __inline struct ifvlan * vlan_gethash(struct ifvlantrunk *trunk,
179 	uint16_t tag);
180 #endif
181 static	void trunk_destroy(struct ifvlantrunk *trunk);
182 
183 static	void vlan_start(struct ifnet *ifp);
184 static	void vlan_init(void *foo);
185 static	void vlan_input(struct ifnet *ifp, struct mbuf *m);
186 static	int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr);
187 static	int vlan_setflag(struct ifnet *ifp, int flag, int status,
188     int (*func)(struct ifnet *, int));
189 static	int vlan_setflags(struct ifnet *ifp, int status);
190 static	int vlan_setmulti(struct ifnet *ifp);
191 static	int vlan_unconfig(struct ifnet *ifp);
192 static	int vlan_unconfig_locked(struct ifnet *ifp);
193 static	int vlan_config(struct ifvlan *ifv, struct ifnet *p, uint16_t tag);
194 static	void vlan_link_state(struct ifnet *ifp, int link);
195 static	void vlan_capabilities(struct ifvlan *ifv);
196 static	void vlan_trunk_capabilities(struct ifnet *ifp);
197 
198 static	struct ifnet *vlan_clone_match_ethertag(struct if_clone *,
199     const char *, int *);
200 static	int vlan_clone_match(struct if_clone *, const char *);
201 static	int vlan_clone_create(struct if_clone *, char *, size_t, caddr_t);
202 static	int vlan_clone_destroy(struct if_clone *, struct ifnet *);
203 
204 static	void vlan_ifdetach(void *arg, struct ifnet *ifp);
205 
206 static	struct if_clone vlan_cloner = IFC_CLONE_INITIALIZER(VLANNAME, NULL,
207     IF_MAXUNIT, NULL, vlan_clone_match, vlan_clone_create, vlan_clone_destroy);
208 
209 #ifndef VLAN_ARRAY
210 #define HASH(n, m)	((((n) >> 8) ^ ((n) >> 4) ^ (n)) & (m))
211 
212 static void
213 vlan_inithash(struct ifvlantrunk *trunk)
214 {
215 	int i, n;
216 
217 	/*
218 	 * The trunk must not be locked here since we call malloc(M_WAITOK).
219 	 * It is OK in case this function is called before the trunk struct
220 	 * gets hooked up and becomes visible from other threads.
221 	 */
222 
223 	KASSERT(trunk->hwidth == 0 && trunk->hash == NULL,
224 	    ("%s: hash already initialized", __func__));
225 
226 	trunk->hwidth = VLAN_DEF_HWIDTH;
227 	n = 1 << trunk->hwidth;
228 	trunk->hmask = n - 1;
229 	trunk->hash = malloc(sizeof(struct ifvlanhead) * n, M_VLAN, M_WAITOK);
230 	for (i = 0; i < n; i++)
231 		LIST_INIT(&trunk->hash[i]);
232 }
233 
234 static void
235 vlan_freehash(struct ifvlantrunk *trunk)
236 {
237 #ifdef INVARIANTS
238 	int i;
239 
240 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
241 	for (i = 0; i < (1 << trunk->hwidth); i++)
242 		KASSERT(LIST_EMPTY(&trunk->hash[i]),
243 		    ("%s: hash table not empty", __func__));
244 #endif
245 	free(trunk->hash, M_VLAN);
246 	trunk->hash = NULL;
247 	trunk->hwidth = trunk->hmask = 0;
248 }
249 
250 static int
251 vlan_inshash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
252 {
253 	int i, b;
254 	struct ifvlan *ifv2;
255 
256 	TRUNK_LOCK_ASSERT(trunk);
257 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
258 
259 	b = 1 << trunk->hwidth;
260 	i = HASH(ifv->ifv_tag, trunk->hmask);
261 	LIST_FOREACH(ifv2, &trunk->hash[i], ifv_list)
262 		if (ifv->ifv_tag == ifv2->ifv_tag)
263 			return (EEXIST);
264 
265 	/*
266 	 * Grow the hash when the number of vlans exceeds half of the number of
267 	 * hash buckets squared. This will make the average linked-list length
268 	 * buckets/2.
269 	 */
270 	if (trunk->refcnt > (b * b) / 2) {
271 		vlan_growhash(trunk, 1);
272 		i = HASH(ifv->ifv_tag, trunk->hmask);
273 	}
274 	LIST_INSERT_HEAD(&trunk->hash[i], ifv, ifv_list);
275 	trunk->refcnt++;
276 
277 	return (0);
278 }
279 
280 static int
281 vlan_remhash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
282 {
283 	int i, b;
284 	struct ifvlan *ifv2;
285 
286 	TRUNK_LOCK_ASSERT(trunk);
287 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
288 
289 	b = 1 << trunk->hwidth;
290 	i = HASH(ifv->ifv_tag, trunk->hmask);
291 	LIST_FOREACH(ifv2, &trunk->hash[i], ifv_list)
292 		if (ifv2 == ifv) {
293 			trunk->refcnt--;
294 			LIST_REMOVE(ifv2, ifv_list);
295 			if (trunk->refcnt < (b * b) / 2)
296 				vlan_growhash(trunk, -1);
297 			return (0);
298 		}
299 
300 	panic("%s: vlan not found\n", __func__);
301 	return (ENOENT); /*NOTREACHED*/
302 }
303 
304 /*
305  * Grow the hash larger or smaller if memory permits.
306  */
307 static void
308 vlan_growhash(struct ifvlantrunk *trunk, int howmuch)
309 {
310 
311 	struct ifvlan *ifv;
312 	struct ifvlanhead *hash2;
313 	int hwidth2, i, j, n, n2;
314 
315 	TRUNK_LOCK_ASSERT(trunk);
316 	KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
317 
318 	if (howmuch == 0) {
319 		/* Harmless yet obvious coding error */
320 		printf("%s: howmuch is 0\n", __func__);
321 		return;
322 	}
323 
324 	hwidth2 = trunk->hwidth + howmuch;
325 	n = 1 << trunk->hwidth;
326 	n2 = 1 << hwidth2;
327 	/* Do not shrink the table below the default */
328 	if (hwidth2 < VLAN_DEF_HWIDTH)
329 		return;
330 
331 	/* M_NOWAIT because we're called with trunk mutex held */
332 	hash2 = malloc(sizeof(struct ifvlanhead) * n2, M_VLAN, M_NOWAIT);
333 	if (hash2 == NULL) {
334 		printf("%s: out of memory -- hash size not changed\n",
335 		    __func__);
336 		return;		/* We can live with the old hash table */
337 	}
338 	for (j = 0; j < n2; j++)
339 		LIST_INIT(&hash2[j]);
340 	for (i = 0; i < n; i++)
341 		while (!LIST_EMPTY(&trunk->hash[i])) {
342 			ifv = LIST_FIRST(&trunk->hash[i]);
343 			LIST_REMOVE(ifv, ifv_list);
344 			j = HASH(ifv->ifv_tag, n2 - 1);
345 			LIST_INSERT_HEAD(&hash2[j], ifv, ifv_list);
346 		}
347 	free(trunk->hash, M_VLAN);
348 	trunk->hash = hash2;
349 	trunk->hwidth = hwidth2;
350 	trunk->hmask = n2 - 1;
351 }
352 
353 static __inline struct ifvlan *
354 vlan_gethash(struct ifvlantrunk *trunk, uint16_t tag)
355 {
356 	struct ifvlan *ifv;
357 
358 	TRUNK_LOCK_RASSERT(trunk);
359 
360 	LIST_FOREACH(ifv, &trunk->hash[HASH(tag, trunk->hmask)], ifv_list)
361 		if (ifv->ifv_tag == tag)
362 			return (ifv);
363 	return (NULL);
364 }
365 
366 #if 0
367 /* Debugging code to view the hashtables. */
368 static void
369 vlan_dumphash(struct ifvlantrunk *trunk)
370 {
371 	int i;
372 	struct ifvlan *ifv;
373 
374 	for (i = 0; i < (1 << trunk->hwidth); i++) {
375 		printf("%d: ", i);
376 		LIST_FOREACH(ifv, &trunk->hash[i], ifv_list)
377 			printf("%s ", ifv->ifv_ifp->if_xname);
378 		printf("\n");
379 	}
380 }
381 #endif /* 0 */
382 #endif /* !VLAN_ARRAY */
383 
384 static void
385 trunk_destroy(struct ifvlantrunk *trunk)
386 {
387 	VLAN_LOCK_ASSERT();
388 
389 	TRUNK_LOCK(trunk);
390 #ifndef VLAN_ARRAY
391 	vlan_freehash(trunk);
392 #endif
393 	trunk->parent->if_vlantrunk = NULL;
394 	LIST_REMOVE(trunk, trunk_entry);
395 	TRUNK_UNLOCK(trunk);
396 	TRUNK_LOCK_DESTROY(trunk);
397 	free(trunk, M_VLAN);
398 }
399 
400 /*
401  * Program our multicast filter. What we're actually doing is
402  * programming the multicast filter of the parent. This has the
403  * side effect of causing the parent interface to receive multicast
404  * traffic that it doesn't really want, which ends up being discarded
405  * later by the upper protocol layers. Unfortunately, there's no way
406  * to avoid this: there really is only one physical interface.
407  *
408  * XXX: There is a possible race here if more than one thread is
409  *      modifying the multicast state of the vlan interface at the same time.
410  */
411 static int
412 vlan_setmulti(struct ifnet *ifp)
413 {
414 	struct ifnet		*ifp_p;
415 	struct ifmultiaddr	*ifma, *rifma = NULL;
416 	struct ifvlan		*sc;
417 	struct vlan_mc_entry	*mc = NULL;
418 	struct sockaddr_dl	sdl;
419 	int			error;
420 
421 	/*VLAN_LOCK_ASSERT();*/
422 
423 	/* Find the parent. */
424 	sc = ifp->if_softc;
425 	ifp_p = PARENT(sc);
426 
427 	bzero((char *)&sdl, sizeof(sdl));
428 	sdl.sdl_len = sizeof(sdl);
429 	sdl.sdl_family = AF_LINK;
430 	sdl.sdl_index = ifp_p->if_index;
431 	sdl.sdl_type = IFT_ETHER;
432 	sdl.sdl_alen = ETHER_ADDR_LEN;
433 
434 	/* First, remove any existing filter entries. */
435 	while (SLIST_FIRST(&sc->vlan_mc_listhead) != NULL) {
436 		mc = SLIST_FIRST(&sc->vlan_mc_listhead);
437 		bcopy((char *)&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN);
438 		error = if_delmulti(ifp_p, (struct sockaddr *)&sdl);
439 		if (error)
440 			return (error);
441 		SLIST_REMOVE_HEAD(&sc->vlan_mc_listhead, mc_entries);
442 		free(mc, M_VLAN);
443 	}
444 
445 	/* Now program new ones. */
446 	TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
447 		if (ifma->ifma_addr->sa_family != AF_LINK)
448 			continue;
449 		mc = malloc(sizeof(struct vlan_mc_entry), M_VLAN, M_NOWAIT);
450 		if (mc == NULL)
451 			return (ENOMEM);
452 		bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
453 		    (char *)&mc->mc_addr, ETHER_ADDR_LEN);
454 		SLIST_INSERT_HEAD(&sc->vlan_mc_listhead, mc, mc_entries);
455 		bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
456 		    LLADDR(&sdl), ETHER_ADDR_LEN);
457 		error = if_addmulti(ifp_p, (struct sockaddr *)&sdl, &rifma);
458 		if (error)
459 			return (error);
460 	}
461 
462 	return (0);
463 }
464 
465 /*
466  * A handler for network interface departure events.
467  * Track departure of trunks here so that we don't access invalid
468  * pointers or whatever if a trunk is ripped from under us, e.g.,
469  * by ejecting its hot-plug card.
470  */
471 static void
472 vlan_ifdetach(void *arg __unused, struct ifnet *ifp)
473 {
474 	struct ifvlan *ifv;
475 	int i;
476 
477 	/*
478 	 * Check if it's a trunk interface first of all
479 	 * to avoid needless locking.
480 	 */
481 	if (ifp->if_vlantrunk == NULL)
482 		return;
483 
484 	VLAN_LOCK();
485 	/*
486 	 * OK, it's a trunk.  Loop over and detach all vlan's on it.
487 	 * Check trunk pointer after each vlan_unconfig() as it will
488 	 * free it and set to NULL after the last vlan was detached.
489 	 */
490 #ifdef VLAN_ARRAY
491 	for (i = 0; i < VLAN_ARRAY_SIZE; i++)
492 		if ((ifv = ifp->if_vlantrunk->vlans[i])) {
493 			vlan_unconfig_locked(ifv->ifv_ifp);
494 			if (ifp->if_vlantrunk == NULL)
495 				break;
496 		}
497 #else /* VLAN_ARRAY */
498 restart:
499 	for (i = 0; i < (1 << ifp->if_vlantrunk->hwidth); i++)
500 		if ((ifv = LIST_FIRST(&ifp->if_vlantrunk->hash[i]))) {
501 			vlan_unconfig_locked(ifv->ifv_ifp);
502 			if (ifp->if_vlantrunk)
503 				goto restart;	/* trunk->hwidth can change */
504 			else
505 				break;
506 		}
507 #endif /* VLAN_ARRAY */
508 	/* Trunk should have been destroyed in vlan_unconfig(). */
509 	KASSERT(ifp->if_vlantrunk == NULL, ("%s: purge failed", __func__));
510 	VLAN_UNLOCK();
511 }
512 
513 /*
514  * VLAN support can be loaded as a module.  The only place in the
515  * system that's intimately aware of this is ether_input.  We hook
516  * into this code through vlan_input_p which is defined there and
517  * set here.  Noone else in the system should be aware of this so
518  * we use an explicit reference here.
519  */
520 extern	void (*vlan_input_p)(struct ifnet *, struct mbuf *);
521 
522 /* For if_link_state_change() eyes only... */
523 extern	void (*vlan_link_state_p)(struct ifnet *, int);
524 
525 static int
526 vlan_modevent(module_t mod, int type, void *data)
527 {
528 
529 	switch (type) {
530 	case MOD_LOAD:
531 		ifdetach_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
532 		    vlan_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
533 		if (ifdetach_tag == NULL)
534 			return (ENOMEM);
535 		LIST_INIT(&trunk_list);
536 		VLAN_LOCK_INIT();
537 		vlan_input_p = vlan_input;
538 		vlan_link_state_p = vlan_link_state;
539 		vlan_trunk_cap_p = vlan_trunk_capabilities;
540 		if_clone_attach(&vlan_cloner);
541 		break;
542 	case MOD_UNLOAD:
543 	    {
544 		struct ifvlantrunk *trunk, *trunk1;
545 
546 		if_clone_detach(&vlan_cloner);
547 		EVENTHANDLER_DEREGISTER(ifnet_departure_event, ifdetach_tag);
548 		vlan_input_p = NULL;
549 		vlan_link_state_p = NULL;
550 		vlan_trunk_cap_p = NULL;
551 		VLAN_LOCK();
552 		LIST_FOREACH_SAFE(trunk, &trunk_list, trunk_entry, trunk1)
553 			trunk_destroy(trunk);
554 		VLAN_UNLOCK();
555 		VLAN_LOCK_DESTROY();
556 		break;
557 	    }
558 	default:
559 		return (EOPNOTSUPP);
560 	}
561 	return (0);
562 }
563 
564 static moduledata_t vlan_mod = {
565 	"if_vlan",
566 	vlan_modevent,
567 	0
568 };
569 
570 DECLARE_MODULE(if_vlan, vlan_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
571 MODULE_VERSION(if_vlan, 3);
572 MODULE_DEPEND(if_vlan, miibus, 1, 1, 1);
573 
574 static struct ifnet *
575 vlan_clone_match_ethertag(struct if_clone *ifc, const char *name, int *tag)
576 {
577 	const char *cp;
578 	struct ifnet *ifp;
579 	int t = 0;
580 
581 	/* Check for <etherif>.<vlan> style interface names. */
582 	IFNET_RLOCK();
583 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
584 		if (ifp->if_type != IFT_ETHER)
585 			continue;
586 		if (strncmp(ifp->if_xname, name, strlen(ifp->if_xname)) != 0)
587 			continue;
588 		cp = name + strlen(ifp->if_xname);
589 		if (*cp != '.')
590 			continue;
591 		for(; *cp != '\0'; cp++) {
592 			if (*cp < '0' || *cp > '9')
593 				continue;
594 			t = (t * 10) + (*cp - '0');
595 		}
596 		if (tag != NULL)
597 			*tag = t;
598 		break;
599 	}
600 	IFNET_RUNLOCK();
601 
602 	return (ifp);
603 }
604 
605 static int
606 vlan_clone_match(struct if_clone *ifc, const char *name)
607 {
608 	const char *cp;
609 
610 	if (vlan_clone_match_ethertag(ifc, name, NULL) != NULL)
611 		return (1);
612 
613 	if (strncmp(VLANNAME, name, strlen(VLANNAME)) != 0)
614 		return (0);
615 	for (cp = name + 4; *cp != '\0'; cp++) {
616 		if (*cp < '0' || *cp > '9')
617 			return (0);
618 	}
619 
620 	return (1);
621 }
622 
623 static int
624 vlan_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
625 {
626 	char *dp;
627 	int wildcard;
628 	int unit;
629 	int error;
630 	int tag;
631 	int ethertag;
632 	struct ifvlan *ifv;
633 	struct ifnet *ifp;
634 	struct ifnet *p;
635 	struct vlanreq vlr;
636 	static const u_char eaddr[6];	/* 00:00:00:00:00:00 */
637 
638 	/*
639 	 * There are 3 (ugh) ways to specify the cloned device:
640 	 * o pass a parameter block with the clone request.
641 	 * o specify parameters in the text of the clone device name
642 	 * o specify no parameters and get an unattached device that
643 	 *   must be configured separately.
644 	 * The first technique is preferred; the latter two are
645 	 * supported for backwards compatibilty.
646 	 */
647 	if (params) {
648 		error = copyin(params, &vlr, sizeof(vlr));
649 		if (error)
650 			return error;
651 		p = ifunit(vlr.vlr_parent);
652 		if (p == NULL)
653 			return ENXIO;
654 		/*
655 		 * Don't let the caller set up a VLAN tag with
656 		 * anything except VLID bits.
657 		 */
658 		if (vlr.vlr_tag & ~EVL_VLID_MASK)
659 			return (EINVAL);
660 		error = ifc_name2unit(name, &unit);
661 		if (error != 0)
662 			return (error);
663 
664 		ethertag = 1;
665 		tag = vlr.vlr_tag;
666 		wildcard = (unit < 0);
667 	} else if ((p = vlan_clone_match_ethertag(ifc, name, &tag)) != NULL) {
668 		ethertag = 1;
669 		unit = -1;
670 		wildcard = 0;
671 
672 		/*
673 		 * Don't let the caller set up a VLAN tag with
674 		 * anything except VLID bits.
675 		 */
676 		if (tag & ~EVL_VLID_MASK)
677 			return (EINVAL);
678 	} else {
679 		ethertag = 0;
680 
681 		error = ifc_name2unit(name, &unit);
682 		if (error != 0)
683 			return (error);
684 
685 		wildcard = (unit < 0);
686 	}
687 
688 	error = ifc_alloc_unit(ifc, &unit);
689 	if (error != 0)
690 		return (error);
691 
692 	/* In the wildcard case, we need to update the name. */
693 	if (wildcard) {
694 		for (dp = name; *dp != '\0'; dp++);
695 		if (snprintf(dp, len - (dp-name), "%d", unit) >
696 		    len - (dp-name) - 1) {
697 			panic("%s: interface name too long", __func__);
698 		}
699 	}
700 
701 	ifv = malloc(sizeof(struct ifvlan), M_VLAN, M_WAITOK | M_ZERO);
702 	ifp = ifv->ifv_ifp = if_alloc(IFT_ETHER);
703 	if (ifp == NULL) {
704 		ifc_free_unit(ifc, unit);
705 		free(ifv, M_VLAN);
706 		return (ENOSPC);
707 	}
708 	SLIST_INIT(&ifv->vlan_mc_listhead);
709 
710 	ifp->if_softc = ifv;
711 	/*
712 	 * Set the name manually rather than using if_initname because
713 	 * we don't conform to the default naming convention for interfaces.
714 	 */
715 	strlcpy(ifp->if_xname, name, IFNAMSIZ);
716 	ifp->if_dname = ifc->ifc_name;
717 	ifp->if_dunit = unit;
718 	/* NB: flags are not set here */
719 	ifp->if_linkmib = &ifv->ifv_mib;
720 	ifp->if_linkmiblen = sizeof(ifv->ifv_mib);
721 	/* NB: mtu is not set here */
722 
723 	ifp->if_init = vlan_init;
724 	ifp->if_start = vlan_start;
725 	ifp->if_ioctl = vlan_ioctl;
726 	ifp->if_snd.ifq_maxlen = ifqmaxlen;
727 	ifp->if_flags = VLAN_IFFLAGS;
728 	ether_ifattach(ifp, eaddr);
729 	/* Now undo some of the damage... */
730 	ifp->if_baudrate = 0;
731 	ifp->if_type = IFT_L2VLAN;
732 	ifp->if_hdrlen = ETHER_VLAN_ENCAP_LEN;
733 
734 	if (ethertag) {
735 		error = vlan_config(ifv, p, tag);
736 		if (error != 0) {
737 			/*
738 			 * Since we've partialy failed, we need to back
739 			 * out all the way, otherwise userland could get
740 			 * confused.  Thus, we destroy the interface.
741 			 */
742 			ether_ifdetach(ifp);
743 			vlan_unconfig(ifp);
744 			if_free_type(ifp, IFT_ETHER);
745 			free(ifv, M_VLAN);
746 
747 			return (error);
748 		}
749 
750 		/* Update flags on the parent, if necessary. */
751 		vlan_setflags(ifp, 1);
752 	}
753 
754 	return (0);
755 }
756 
757 static int
758 vlan_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
759 {
760 	struct ifvlan *ifv = ifp->if_softc;
761 	int unit = ifp->if_dunit;
762 
763 	ether_ifdetach(ifp);	/* first, remove it from system-wide lists */
764 	vlan_unconfig(ifp);	/* now it can be unconfigured and freed */
765 	if_free_type(ifp, IFT_ETHER);
766 	free(ifv, M_VLAN);
767 	ifc_free_unit(ifc, unit);
768 
769 	return (0);
770 }
771 
772 /*
773  * The ifp->if_init entry point for vlan(4) is a no-op.
774  */
775 static void
776 vlan_init(void *foo __unused)
777 {
778 }
779 
780 /*
781  * The if_start method for vlan(4) interface. It doesn't
782  * raises the IFF_DRV_OACTIVE flag, since it is called
783  * only from IFQ_HANDOFF() macro in ether_output_frame().
784  * If the interface queue is full, and vlan_start() is
785  * not called, the queue would never get emptied and
786  * interface would stall forever.
787  */
788 static void
789 vlan_start(struct ifnet *ifp)
790 {
791 	struct ifvlan *ifv;
792 	struct ifnet *p;
793 	struct mbuf *m;
794 	int error;
795 
796 	ifv = ifp->if_softc;
797 	p = PARENT(ifv);
798 
799 	for (;;) {
800 		IF_DEQUEUE(&ifp->if_snd, m);
801 		if (m == 0)
802 			break;
803 		BPF_MTAP(ifp, m);
804 
805 		/*
806 		 * Do not run parent's if_start() if the parent is not up,
807 		 * or parent's driver will cause a system crash.
808 		 */
809 		if (!((p->if_flags & IFF_UP) &&
810 		    (p->if_drv_flags & IFF_DRV_RUNNING))) {
811 			m_freem(m);
812 			ifp->if_collisions++;
813 			continue;
814 		}
815 
816 		/*
817 		 * Pad the frame to the minimum size allowed if told to.
818 		 * This option is in accord with IEEE Std 802.1Q, 2003 Ed.,
819 		 * paragraph C.4.4.3.b.  It can help to work around buggy
820 		 * bridges that violate paragraph C.4.4.3.a from the same
821 		 * document, i.e., fail to pad short frames after untagging.
822 		 * E.g., a tagged frame 66 bytes long (incl. FCS) is OK, but
823 		 * untagging it will produce a 62-byte frame, which is a runt
824 		 * and requires padding.  There are VLAN-enabled network
825 		 * devices that just discard such runts instead or mishandle
826 		 * them somehow.
827 		 */
828 		if (soft_pad) {
829 			static char pad[8];	/* just zeros */
830 			int n;
831 
832 			for (n = ETHERMIN + ETHER_HDR_LEN - m->m_pkthdr.len;
833 			     n > 0; n -= sizeof(pad))
834 				if (!m_append(m, min(n, sizeof(pad)), pad))
835 					break;
836 
837 			if (n > 0) {
838 				if_printf(ifp, "cannot pad short frame\n");
839 				ifp->if_oerrors++;
840 				m_freem(m);
841 				continue;
842 			}
843 		}
844 
845 		/*
846 		 * If underlying interface can do VLAN tag insertion itself,
847 		 * just pass the packet along. However, we need some way to
848 		 * tell the interface where the packet came from so that it
849 		 * knows how to find the VLAN tag to use, so we attach a
850 		 * packet tag that holds it.
851 		 */
852 		if (p->if_capenable & IFCAP_VLAN_HWTAGGING) {
853 			m->m_pkthdr.ether_vtag = ifv->ifv_tag;
854 			m->m_flags |= M_VLANTAG;
855 		} else {
856 			struct ether_vlan_header *evl;
857 
858 			M_PREPEND(m, ifv->ifv_encaplen, M_DONTWAIT);
859 			if (m == NULL) {
860 				if_printf(ifp,
861 				    "unable to prepend VLAN header\n");
862 				ifp->if_oerrors++;
863 				continue;
864 			}
865 			/* M_PREPEND takes care of m_len, m_pkthdr.len for us */
866 
867 			if (m->m_len < sizeof(*evl)) {
868 				m = m_pullup(m, sizeof(*evl));
869 				if (m == NULL) {
870 					if_printf(ifp,
871 					    "cannot pullup VLAN header\n");
872 					ifp->if_oerrors++;
873 					continue;
874 				}
875 			}
876 
877 			/*
878 			 * Transform the Ethernet header into an Ethernet header
879 			 * with 802.1Q encapsulation.
880 			 */
881 			bcopy(mtod(m, char *) + ifv->ifv_encaplen,
882 			      mtod(m, char *), ETHER_HDR_LEN);
883 			evl = mtod(m, struct ether_vlan_header *);
884 			evl->evl_proto = evl->evl_encap_proto;
885 			evl->evl_encap_proto = htons(ifv->ifv_proto);
886 			evl->evl_tag = htons(ifv->ifv_tag);
887 #ifdef DEBUG
888 			printf("%s: %*D\n", __func__, (int)sizeof(*evl),
889 			    (unsigned char *)evl, ":");
890 #endif
891 		}
892 
893 		/*
894 		 * Send it, precisely as ether_output() would have.
895 		 * We are already running at splimp.
896 		 */
897 		IFQ_HANDOFF(p, m, error);
898 		if (!error)
899 			ifp->if_opackets++;
900 		else
901 			ifp->if_oerrors++;
902 	}
903 }
904 
905 static void
906 vlan_input(struct ifnet *ifp, struct mbuf *m)
907 {
908 	struct ifvlantrunk *trunk = ifp->if_vlantrunk;
909 	struct ifvlan *ifv;
910 	int inenc = 0;
911 	uint16_t tag;
912 
913 	KASSERT(trunk != NULL, ("%s: no trunk", __func__));
914 
915 	if (m->m_flags & M_VLANTAG) {
916 		/*
917 		 * Packet is tagged, but m contains a normal
918 		 * Ethernet frame; the tag is stored out-of-band.
919 		 */
920 		tag = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
921 		m->m_flags &= ~M_VLANTAG;
922 	} else {
923 		struct ether_vlan_header *evl;
924 
925 		/*
926 		 * Packet is tagged in-band as specified by 802.1q.
927 		 */
928 		inenc = 1;
929 		switch (ifp->if_type) {
930 		case IFT_ETHER:
931 			if (m->m_len < sizeof(*evl) &&
932 			    (m = m_pullup(m, sizeof(*evl))) == NULL) {
933 				if_printf(ifp, "cannot pullup VLAN header\n");
934 				return;
935 			}
936 			evl = mtod(m, struct ether_vlan_header *);
937 			tag = EVL_VLANOFTAG(ntohs(evl->evl_tag));
938 
939 			/*
940 			 * Restore the original ethertype.  We'll remove
941 			 * the encapsulation after we've found the vlan
942 			 * interface corresponding to the tag.
943 			 */
944 			evl->evl_encap_proto = evl->evl_proto;
945 			break;
946 		default:
947 #ifdef INVARIANTS
948 			panic("%s: %s has unsupported if_type %u",
949 			      __func__, ifp->if_xname, ifp->if_type);
950 #endif
951 			m_freem(m);
952 			ifp->if_noproto++;
953 			return;
954 		}
955 	}
956 
957 	TRUNK_RLOCK(trunk);
958 #ifdef VLAN_ARRAY
959 	ifv = trunk->vlans[tag];
960 #else
961 	ifv = vlan_gethash(trunk, tag);
962 #endif
963 	if (ifv == NULL || (ifv->ifv_ifp->if_flags & IFF_UP) == 0) {
964 		TRUNK_RUNLOCK(trunk);
965 		m_freem(m);
966 		ifp->if_noproto++;
967 		return;
968 	}
969 	TRUNK_RUNLOCK(trunk);
970 
971 	if (inenc) {
972 		/*
973 		 * Packet had an in-line encapsulation header;
974 		 * remove it.  The original header has already
975 		 * been fixed up above.
976 		 */
977 		bcopy(mtod(m, caddr_t),
978 		      mtod(m, caddr_t) + ETHER_VLAN_ENCAP_LEN,
979 		      ETHER_HDR_LEN);
980 		m_adj(m, ETHER_VLAN_ENCAP_LEN);
981 	}
982 
983 	m->m_pkthdr.rcvif = ifv->ifv_ifp;
984 	ifv->ifv_ifp->if_ipackets++;
985 
986 	/* Pass it back through the parent's input routine. */
987 	(*ifp->if_input)(ifv->ifv_ifp, m);
988 }
989 
990 static int
991 vlan_config(struct ifvlan *ifv, struct ifnet *p, uint16_t tag)
992 {
993 	struct ifvlantrunk *trunk;
994 	struct ifnet *ifp;
995 	int error = 0;
996 
997 	/* VID numbers 0x0 and 0xFFF are reserved */
998 	if (tag == 0 || tag == 0xFFF)
999 		return (EINVAL);
1000 	if (p->if_type != IFT_ETHER)
1001 		return (EPROTONOSUPPORT);
1002 	if ((p->if_flags & VLAN_IFFLAGS) != VLAN_IFFLAGS)
1003 		return (EPROTONOSUPPORT);
1004 	if (ifv->ifv_trunk)
1005 		return (EBUSY);
1006 
1007 	if (p->if_vlantrunk == NULL) {
1008 		trunk = malloc(sizeof(struct ifvlantrunk),
1009 		    M_VLAN, M_WAITOK | M_ZERO);
1010 #ifndef VLAN_ARRAY
1011 		vlan_inithash(trunk);
1012 #endif
1013 		VLAN_LOCK();
1014 		if (p->if_vlantrunk != NULL) {
1015 			/* A race that that is very unlikely to be hit. */
1016 #ifndef VLAN_ARRAY
1017 			vlan_freehash(trunk);
1018 #endif
1019 			free(trunk, M_VLAN);
1020 			goto exists;
1021 		}
1022 		TRUNK_LOCK_INIT(trunk);
1023 		LIST_INSERT_HEAD(&trunk_list, trunk, trunk_entry);
1024 		TRUNK_LOCK(trunk);
1025 		p->if_vlantrunk = trunk;
1026 		trunk->parent = p;
1027 	} else {
1028 		VLAN_LOCK();
1029 exists:
1030 		trunk = p->if_vlantrunk;
1031 		TRUNK_LOCK(trunk);
1032 	}
1033 
1034 	ifv->ifv_tag = tag;	/* must set this before vlan_inshash() */
1035 #ifdef VLAN_ARRAY
1036 	if (trunk->vlans[tag] != NULL) {
1037 		error = EEXIST;
1038 		goto done;
1039 	}
1040 	trunk->vlans[tag] = ifv;
1041 	trunk->refcnt++;
1042 #else
1043 	error = vlan_inshash(trunk, ifv);
1044 	if (error)
1045 		goto done;
1046 #endif
1047 	ifv->ifv_proto = ETHERTYPE_VLAN;
1048 	ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN;
1049 	ifv->ifv_mintu = ETHERMIN;
1050 	ifv->ifv_pflags = 0;
1051 
1052 	/*
1053 	 * If the parent supports the VLAN_MTU capability,
1054 	 * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames,
1055 	 * use it.
1056 	 */
1057 	if (p->if_capenable & IFCAP_VLAN_MTU) {
1058 		/*
1059 		 * No need to fudge the MTU since the parent can
1060 		 * handle extended frames.
1061 		 */
1062 		ifv->ifv_mtufudge = 0;
1063 	} else {
1064 		/*
1065 		 * Fudge the MTU by the encapsulation size.  This
1066 		 * makes us incompatible with strictly compliant
1067 		 * 802.1Q implementations, but allows us to use
1068 		 * the feature with other NetBSD implementations,
1069 		 * which might still be useful.
1070 		 */
1071 		ifv->ifv_mtufudge = ifv->ifv_encaplen;
1072 	}
1073 
1074 	ifv->ifv_trunk = trunk;
1075 	ifp = ifv->ifv_ifp;
1076 	ifp->if_mtu = p->if_mtu - ifv->ifv_mtufudge;
1077 	ifp->if_baudrate = p->if_baudrate;
1078 	/*
1079 	 * Copy only a selected subset of flags from the parent.
1080 	 * Other flags are none of our business.
1081 	 */
1082 #define VLAN_COPY_FLAGS (IFF_SIMPLEX)
1083 	ifp->if_flags &= ~VLAN_COPY_FLAGS;
1084 	ifp->if_flags |= p->if_flags & VLAN_COPY_FLAGS;
1085 #undef VLAN_COPY_FLAGS
1086 
1087 	ifp->if_link_state = p->if_link_state;
1088 
1089 	vlan_capabilities(ifv);
1090 
1091 	/*
1092 	 * Set up our ``Ethernet address'' to reflect the underlying
1093 	 * physical interface's.
1094 	 */
1095 	bcopy(IF_LLADDR(p), IF_LLADDR(ifp), ETHER_ADDR_LEN);
1096 
1097 	/*
1098 	 * Configure multicast addresses that may already be
1099 	 * joined on the vlan device.
1100 	 */
1101 	(void)vlan_setmulti(ifp); /* XXX: VLAN lock held */
1102 
1103 	/* We are ready for operation now. */
1104 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1105 done:
1106 	TRUNK_UNLOCK(trunk);
1107 	VLAN_UNLOCK();
1108 
1109 	return (error);
1110 }
1111 
1112 static int
1113 vlan_unconfig(struct ifnet *ifp)
1114 {
1115 	int ret;
1116 
1117 	VLAN_LOCK();
1118 	ret = vlan_unconfig_locked(ifp);
1119 	VLAN_UNLOCK();
1120 	return (ret);
1121 }
1122 
1123 static int
1124 vlan_unconfig_locked(struct ifnet *ifp)
1125 {
1126 	struct ifvlantrunk *trunk;
1127 	struct vlan_mc_entry *mc;
1128 	struct ifvlan *ifv;
1129 	int error;
1130 
1131 	VLAN_LOCK_ASSERT();
1132 
1133 	ifv = ifp->if_softc;
1134 	trunk = ifv->ifv_trunk;
1135 
1136 	if (trunk) {
1137 		struct sockaddr_dl sdl;
1138 		struct ifnet *p = trunk->parent;
1139 
1140 		TRUNK_LOCK(trunk);
1141 
1142 		/*
1143 		 * Since the interface is being unconfigured, we need to
1144 		 * empty the list of multicast groups that we may have joined
1145 		 * while we were alive from the parent's list.
1146 		 */
1147 		bzero((char *)&sdl, sizeof(sdl));
1148 		sdl.sdl_len = sizeof(sdl);
1149 		sdl.sdl_family = AF_LINK;
1150 		sdl.sdl_index = p->if_index;
1151 		sdl.sdl_type = IFT_ETHER;
1152 		sdl.sdl_alen = ETHER_ADDR_LEN;
1153 
1154 		while(SLIST_FIRST(&ifv->vlan_mc_listhead) != NULL) {
1155 			mc = SLIST_FIRST(&ifv->vlan_mc_listhead);
1156 			bcopy((char *)&mc->mc_addr, LLADDR(&sdl),
1157 			    ETHER_ADDR_LEN);
1158 			error = if_delmulti(p, (struct sockaddr *)&sdl);
1159 			if (error)
1160 				return (error);
1161 			SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
1162 			free(mc, M_VLAN);
1163 		}
1164 
1165 		vlan_setflags(ifp, 0); /* clear special flags on parent */
1166 #ifdef VLAN_ARRAY
1167 		trunk->vlans[ifv->ifv_tag] = NULL;
1168 		trunk->refcnt--;
1169 #else
1170 		vlan_remhash(trunk, ifv);
1171 #endif
1172 		ifv->ifv_trunk = NULL;
1173 
1174 		/*
1175 		 * Check if we were the last.
1176 		 */
1177 		if (trunk->refcnt == 0) {
1178 			trunk->parent->if_vlantrunk = NULL;
1179 			/*
1180 			 * XXXGL: If some ithread has already entered
1181 			 * vlan_input() and is now blocked on the trunk
1182 			 * lock, then it should preempt us right after
1183 			 * unlock and finish its work. Then we will acquire
1184 			 * lock again in trunk_destroy().
1185 			 */
1186 			TRUNK_UNLOCK(trunk);
1187 			trunk_destroy(trunk);
1188 		} else
1189 			TRUNK_UNLOCK(trunk);
1190 	}
1191 
1192 	/* Disconnect from parent. */
1193 	if (ifv->ifv_pflags)
1194 		if_printf(ifp, "%s: ifv_pflags unclean\n", __func__);
1195 	ifp->if_mtu = ETHERMTU;
1196 	ifp->if_link_state = LINK_STATE_UNKNOWN;
1197 	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1198 
1199 	return (0);
1200 }
1201 
1202 /* Handle a reference counted flag that should be set on the parent as well */
1203 static int
1204 vlan_setflag(struct ifnet *ifp, int flag, int status,
1205 	     int (*func)(struct ifnet *, int))
1206 {
1207 	struct ifvlan *ifv;
1208 	int error;
1209 
1210 	/* XXX VLAN_LOCK_ASSERT(); */
1211 
1212 	ifv = ifp->if_softc;
1213 	status = status ? (ifp->if_flags & flag) : 0;
1214 	/* Now "status" contains the flag value or 0 */
1215 
1216 	/*
1217 	 * See if recorded parent's status is different from what
1218 	 * we want it to be.  If it is, flip it.  We record parent's
1219 	 * status in ifv_pflags so that we won't clear parent's flag
1220 	 * we haven't set.  In fact, we don't clear or set parent's
1221 	 * flags directly, but get or release references to them.
1222 	 * That's why we can be sure that recorded flags still are
1223 	 * in accord with actual parent's flags.
1224 	 */
1225 	if (status != (ifv->ifv_pflags & flag)) {
1226 		error = (*func)(PARENT(ifv), status);
1227 		if (error)
1228 			return (error);
1229 		ifv->ifv_pflags &= ~flag;
1230 		ifv->ifv_pflags |= status;
1231 	}
1232 	return (0);
1233 }
1234 
1235 /*
1236  * Handle IFF_* flags that require certain changes on the parent:
1237  * if "status" is true, update parent's flags respective to our if_flags;
1238  * if "status" is false, forcedly clear the flags set on parent.
1239  */
1240 static int
1241 vlan_setflags(struct ifnet *ifp, int status)
1242 {
1243 	int error, i;
1244 
1245 	for (i = 0; vlan_pflags[i].flag; i++) {
1246 		error = vlan_setflag(ifp, vlan_pflags[i].flag,
1247 				     status, vlan_pflags[i].func);
1248 		if (error)
1249 			return (error);
1250 	}
1251 	return (0);
1252 }
1253 
1254 /* Inform all vlans that their parent has changed link state */
1255 static void
1256 vlan_link_state(struct ifnet *ifp, int link)
1257 {
1258 	struct ifvlantrunk *trunk = ifp->if_vlantrunk;
1259 	struct ifvlan *ifv;
1260 	int i;
1261 
1262 	TRUNK_LOCK(trunk);
1263 #ifdef VLAN_ARRAY
1264 	for (i = 0; i < VLAN_ARRAY_SIZE; i++)
1265 		if (trunk->vlans[i] != NULL) {
1266 			ifv = trunk->vlans[i];
1267 #else
1268 	for (i = 0; i < (1 << trunk->hwidth); i++)
1269 		LIST_FOREACH(ifv, &trunk->hash[i], ifv_list) {
1270 #endif
1271 			ifv->ifv_ifp->if_baudrate = trunk->parent->if_baudrate;
1272 			if_link_state_change(ifv->ifv_ifp,
1273 			    trunk->parent->if_link_state);
1274 		}
1275 	TRUNK_UNLOCK(trunk);
1276 }
1277 
1278 static void
1279 vlan_capabilities(struct ifvlan *ifv)
1280 {
1281 	struct ifnet *p = PARENT(ifv);
1282 	struct ifnet *ifp = ifv->ifv_ifp;
1283 
1284 	TRUNK_LOCK_ASSERT(TRUNK(ifv));
1285 
1286 	/*
1287 	 * If the parent interface can do checksum offloading
1288 	 * on VLANs, then propagate its hardware-assisted
1289 	 * checksumming flags. Also assert that checksum
1290 	 * offloading requires hardware VLAN tagging.
1291 	 */
1292 	if (p->if_capabilities & IFCAP_VLAN_HWCSUM)
1293 		ifp->if_capabilities = p->if_capabilities & IFCAP_HWCSUM;
1294 
1295 	if (p->if_capenable & IFCAP_VLAN_HWCSUM &&
1296 	    p->if_capenable & IFCAP_VLAN_HWTAGGING) {
1297 		ifp->if_capenable = p->if_capenable & IFCAP_HWCSUM;
1298 		ifp->if_hwassist = p->if_hwassist;
1299 	} else {
1300 		ifp->if_capenable = 0;
1301 		ifp->if_hwassist = 0;
1302 	}
1303 }
1304 
1305 static void
1306 vlan_trunk_capabilities(struct ifnet *ifp)
1307 {
1308 	struct ifvlantrunk *trunk = ifp->if_vlantrunk;
1309 	struct ifvlan *ifv;
1310 	int i;
1311 
1312 	TRUNK_LOCK(trunk);
1313 #ifdef VLAN_ARRAY
1314 	for (i = 0; i < VLAN_ARRAY_SIZE; i++)
1315 		if (trunk->vlans[i] != NULL) {
1316 			ifv = trunk->vlans[i];
1317 #else
1318 	for (i = 0; i < (1 << trunk->hwidth); i++) {
1319 		LIST_FOREACH(ifv, &trunk->hash[i], ifv_list)
1320 #endif
1321 			vlan_capabilities(ifv);
1322 	}
1323 	TRUNK_UNLOCK(trunk);
1324 }
1325 
1326 static int
1327 vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1328 {
1329 	struct ifaddr *ifa;
1330 	struct ifnet *p;
1331 	struct ifreq *ifr;
1332 	struct ifvlan *ifv;
1333 	struct vlanreq vlr;
1334 	int error = 0;
1335 
1336 	ifr = (struct ifreq *)data;
1337 	ifa = (struct ifaddr *)data;
1338 	ifv = ifp->if_softc;
1339 
1340 	switch (cmd) {
1341 	case SIOCSIFADDR:
1342 		ifp->if_flags |= IFF_UP;
1343 
1344 		switch (ifa->ifa_addr->sa_family) {
1345 #ifdef INET
1346 		case AF_INET:
1347 			arp_ifinit(ifv->ifv_ifp, ifa);
1348 			break;
1349 #endif
1350 		default:
1351 			break;
1352 		}
1353 		break;
1354 
1355 	case SIOCGIFADDR:
1356 		{
1357 			struct sockaddr *sa;
1358 
1359 			sa = (struct sockaddr *) &ifr->ifr_data;
1360 			bcopy(IF_LLADDR(ifp), (caddr_t)sa->sa_data,
1361 			    ETHER_ADDR_LEN);
1362 		}
1363 		break;
1364 
1365 	case SIOCGIFMEDIA:
1366 		VLAN_LOCK();
1367 		if (TRUNK(ifv) != NULL) {
1368 			error = (*PARENT(ifv)->if_ioctl)(PARENT(ifv),
1369 					SIOCGIFMEDIA, data);
1370 			VLAN_UNLOCK();
1371 			/* Limit the result to the parent's current config. */
1372 			if (error == 0) {
1373 				struct ifmediareq *ifmr;
1374 
1375 				ifmr = (struct ifmediareq *)data;
1376 				if (ifmr->ifm_count >= 1 && ifmr->ifm_ulist) {
1377 					ifmr->ifm_count = 1;
1378 					error = copyout(&ifmr->ifm_current,
1379 						ifmr->ifm_ulist,
1380 						sizeof(int));
1381 				}
1382 			}
1383 		} else {
1384 			VLAN_UNLOCK();
1385 			error = EINVAL;
1386 		}
1387 		break;
1388 
1389 	case SIOCSIFMEDIA:
1390 		error = EINVAL;
1391 		break;
1392 
1393 	case SIOCSIFMTU:
1394 		/*
1395 		 * Set the interface MTU.
1396 		 */
1397 		VLAN_LOCK();
1398 		if (TRUNK(ifv) != NULL) {
1399 			if (ifr->ifr_mtu >
1400 			     (PARENT(ifv)->if_mtu - ifv->ifv_mtufudge) ||
1401 			    ifr->ifr_mtu <
1402 			     (ifv->ifv_mintu - ifv->ifv_mtufudge))
1403 				error = EINVAL;
1404 			else
1405 				ifp->if_mtu = ifr->ifr_mtu;
1406 		} else
1407 			error = EINVAL;
1408 		VLAN_UNLOCK();
1409 		break;
1410 
1411 	case SIOCSETVLAN:
1412 		error = copyin(ifr->ifr_data, &vlr, sizeof(vlr));
1413 		if (error)
1414 			break;
1415 		if (vlr.vlr_parent[0] == '\0') {
1416 			vlan_unconfig(ifp);
1417 			break;
1418 		}
1419 		p = ifunit(vlr.vlr_parent);
1420 		if (p == 0) {
1421 			error = ENOENT;
1422 			break;
1423 		}
1424 		/*
1425 		 * Don't let the caller set up a VLAN tag with
1426 		 * anything except VLID bits.
1427 		 */
1428 		if (vlr.vlr_tag & ~EVL_VLID_MASK) {
1429 			error = EINVAL;
1430 			break;
1431 		}
1432 		error = vlan_config(ifv, p, vlr.vlr_tag);
1433 		if (error)
1434 			break;
1435 
1436 		/* Update flags on the parent, if necessary. */
1437 		vlan_setflags(ifp, 1);
1438 		break;
1439 
1440 	case SIOCGETVLAN:
1441 		bzero(&vlr, sizeof(vlr));
1442 		VLAN_LOCK();
1443 		if (TRUNK(ifv) != NULL) {
1444 			strlcpy(vlr.vlr_parent, PARENT(ifv)->if_xname,
1445 			    sizeof(vlr.vlr_parent));
1446 			vlr.vlr_tag = ifv->ifv_tag;
1447 		}
1448 		VLAN_UNLOCK();
1449 		error = copyout(&vlr, ifr->ifr_data, sizeof(vlr));
1450 		break;
1451 
1452 	case SIOCSIFFLAGS:
1453 		/*
1454 		 * We should propagate selected flags to the parent,
1455 		 * e.g., promiscuous mode.
1456 		 */
1457 		if (TRUNK(ifv) != NULL)
1458 			error = vlan_setflags(ifp, 1);
1459 		break;
1460 
1461 	case SIOCADDMULTI:
1462 	case SIOCDELMULTI:
1463 		/*
1464 		 * If we don't have a parent, just remember the membership for
1465 		 * when we do.
1466 		 */
1467 		if (TRUNK(ifv) != NULL)
1468 			error = vlan_setmulti(ifp);
1469 		break;
1470 
1471 	default:
1472 		error = EINVAL;
1473 	}
1474 
1475 	return (error);
1476 }
1477