xref: /netbsd-src/sys/net/if_vlan.c (revision f3b496ec9be495acbb17756f05d342b6b7b495e9)
1 /*	$NetBSD: if_vlan.c,v 1.49 2006/07/23 22:06:13 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran, and by Jason R. Thorpe of Zembu Labs, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright 1998 Massachusetts Institute of Technology
41  *
42  * Permission to use, copy, modify, and distribute this software and
43  * its documentation for any purpose and without fee is hereby
44  * granted, provided that both the above copyright notice and this
45  * permission notice appear in all copies, that both the above
46  * copyright notice and this permission notice appear in all
47  * supporting documentation, and that the name of M.I.T. not be used
48  * in advertising or publicity pertaining to distribution of the
49  * software without specific, written prior permission.  M.I.T. makes
50  * no representations about the suitability of this software for any
51  * purpose.  It is provided "as is" without express or implied
52  * warranty.
53  *
54  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
55  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
56  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
57  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
58  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
59  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
60  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
61  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
62  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
63  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
64  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  * from FreeBSD: if_vlan.c,v 1.16 2000/03/26 15:21:40 charnier Exp
68  * via OpenBSD: if_vlan.c,v 1.4 2000/05/15 19:15:00 chris Exp
69  */
70 
71 /*
72  * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.  Might be
73  * extended some day to also handle IEEE 802.1P priority tagging.  This is
74  * sort of sneaky in the implementation, since we need to pretend to be
75  * enough of an Ethernet implementation to make ARP work.  The way we do
76  * this is by telling everyone that we are an Ethernet interface, and then
77  * catch the packets that ether_output() left on our output queue when it
78  * calls if_start(), rewrite them for use by the real outgoing interface,
79  * and ask it to send them.
80  *
81  * TODO:
82  *
83  *	- Need some way to notify vlan interfaces when the parent
84  *	  interface changes MTU.
85  */
86 
87 #include <sys/cdefs.h>
88 __KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.49 2006/07/23 22:06:13 ad Exp $");
89 
90 #include "opt_inet.h"
91 #include "bpfilter.h"
92 
93 #include <sys/param.h>
94 #include <sys/kernel.h>
95 #include <sys/mbuf.h>
96 #include <sys/queue.h>
97 #include <sys/socket.h>
98 #include <sys/sockio.h>
99 #include <sys/systm.h>
100 #include <sys/proc.h>
101 #include <sys/kauth.h>
102 
103 #if NBPFILTER > 0
104 #include <net/bpf.h>
105 #endif
106 #include <net/if.h>
107 #include <net/if_dl.h>
108 #include <net/if_types.h>
109 #include <net/if_ether.h>
110 #include <net/if_vlanvar.h>
111 
112 #ifdef INET
113 #include <netinet/in.h>
114 #include <netinet/if_inarp.h>
115 #endif
116 
117 struct vlan_mc_entry {
118 	LIST_ENTRY(vlan_mc_entry)	mc_entries;
119 	/*
120 	 * A key to identify this entry.  The mc_addr below can't be
121 	 * used since multiple sockaddr may mapped into the same
122 	 * ether_multi (e.g., AF_UNSPEC).
123 	 */
124 	union {
125 		struct ether_multi	*mcu_enm;
126 	} mc_u;
127 	struct sockaddr_storage		mc_addr;
128 };
129 
130 #define	mc_enm		mc_u.mcu_enm
131 
132 struct ifvlan {
133 	union {
134 		struct ethercom ifvu_ec;
135 	} ifv_u;
136 	struct ifnet *ifv_p;	/* parent interface of this vlan */
137 	struct ifv_linkmib {
138 		const struct vlan_multisw *ifvm_msw;
139 		int	ifvm_encaplen;	/* encapsulation length */
140 		int	ifvm_mtufudge;	/* MTU fudged by this much */
141 		int	ifvm_mintu;	/* min transmission unit */
142 		u_int16_t ifvm_proto;	/* encapsulation ethertype */
143 		u_int16_t ifvm_tag;	/* tag to apply on packets */
144 	} ifv_mib;
145 	LIST_HEAD(__vlan_mchead, vlan_mc_entry) ifv_mc_listhead;
146 	LIST_ENTRY(ifvlan) ifv_list;
147 	int ifv_flags;
148 };
149 
150 #define	IFVF_PROMISC	0x01		/* promiscuous mode enabled */
151 
152 #define	ifv_ec		ifv_u.ifvu_ec
153 
154 #define	ifv_if		ifv_ec.ec_if
155 
156 #define	ifv_msw		ifv_mib.ifvm_msw
157 #define	ifv_encaplen	ifv_mib.ifvm_encaplen
158 #define	ifv_mtufudge	ifv_mib.ifvm_mtufudge
159 #define	ifv_mintu	ifv_mib.ifvm_mintu
160 #define	ifv_tag		ifv_mib.ifvm_tag
161 
162 struct vlan_multisw {
163 	int	(*vmsw_addmulti)(struct ifvlan *, struct ifreq *);
164 	int	(*vmsw_delmulti)(struct ifvlan *, struct ifreq *);
165 	void	(*vmsw_purgemulti)(struct ifvlan *);
166 };
167 
168 static int	vlan_ether_addmulti(struct ifvlan *, struct ifreq *);
169 static int	vlan_ether_delmulti(struct ifvlan *, struct ifreq *);
170 static void	vlan_ether_purgemulti(struct ifvlan *);
171 
172 const struct vlan_multisw vlan_ether_multisw = {
173 	vlan_ether_addmulti,
174 	vlan_ether_delmulti,
175 	vlan_ether_purgemulti,
176 };
177 
178 static int	vlan_clone_create(struct if_clone *, int);
179 static int	vlan_clone_destroy(struct ifnet *);
180 static int	vlan_config(struct ifvlan *, struct ifnet *);
181 static int	vlan_ioctl(struct ifnet *, u_long, caddr_t);
182 static void	vlan_start(struct ifnet *);
183 static void	vlan_unconfig(struct ifnet *);
184 
185 void		vlanattach(int);
186 
187 /* XXX This should be a hash table with the tag as the basis of the key. */
188 static LIST_HEAD(, ifvlan) ifv_list;
189 
190 struct if_clone vlan_cloner =
191     IF_CLONE_INITIALIZER("vlan", vlan_clone_create, vlan_clone_destroy);
192 
193 /* Used to pad ethernet frames with < ETHER_MIN_LEN bytes */
194 static char vlan_zero_pad_buff[ETHER_MIN_LEN];
195 
196 void
197 vlanattach(int n)
198 {
199 
200 	LIST_INIT(&ifv_list);
201 	if_clone_attach(&vlan_cloner);
202 }
203 
204 static void
205 vlan_reset_linkname(struct ifnet *ifp)
206 {
207 
208 	/*
209 	 * We start out with a "802.1Q VLAN" type and zero-length
210 	 * addresses.  When we attach to a parent interface, we
211 	 * inherit its type, address length, address, and data link
212 	 * type.
213 	 */
214 
215 	ifp->if_type = IFT_L2VLAN;
216 	ifp->if_addrlen = 0;
217 	ifp->if_dlt = DLT_NULL;
218 	if_alloc_sadl(ifp);
219 }
220 
221 static int
222 vlan_clone_create(struct if_clone *ifc, int unit)
223 {
224 	struct ifvlan *ifv;
225 	struct ifnet *ifp;
226 	int s;
227 
228 	ifv = malloc(sizeof(struct ifvlan), M_DEVBUF, M_WAITOK);
229 	memset(ifv, 0, sizeof(struct ifvlan));
230 	ifp = &ifv->ifv_if;
231 	LIST_INIT(&ifv->ifv_mc_listhead);
232 
233 	s = splnet();
234 	LIST_INSERT_HEAD(&ifv_list, ifv, ifv_list);
235 	splx(s);
236 
237 	snprintf(ifp->if_xname, sizeof(ifp->if_xname), "%s%d", ifc->ifc_name,
238 	    unit);
239 	ifp->if_softc = ifv;
240 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
241 	ifp->if_start = vlan_start;
242 	ifp->if_ioctl = vlan_ioctl;
243 	IFQ_SET_READY(&ifp->if_snd);
244 
245 	if_attach(ifp);
246 	vlan_reset_linkname(ifp);
247 
248 	return (0);
249 }
250 
251 static int
252 vlan_clone_destroy(struct ifnet *ifp)
253 {
254 	struct ifvlan *ifv = ifp->if_softc;
255 	int s;
256 
257 	s = splnet();
258 	LIST_REMOVE(ifv, ifv_list);
259 	vlan_unconfig(ifp);
260 	splx(s);
261 
262 	if_detach(ifp);
263 	free(ifv, M_DEVBUF);
264 
265 	return (0);
266 }
267 
268 /*
269  * Configure a VLAN interface.  Must be called at splnet().
270  */
271 static int
272 vlan_config(struct ifvlan *ifv, struct ifnet *p)
273 {
274 	struct ifnet *ifp = &ifv->ifv_if;
275 	int error;
276 
277 	if (ifv->ifv_p != NULL)
278 		return (EBUSY);
279 
280 	switch (p->if_type) {
281 	case IFT_ETHER:
282 	    {
283 		struct ethercom *ec = (void *) p;
284 
285 		ifv->ifv_msw = &vlan_ether_multisw;
286 		ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN;
287 		ifv->ifv_mintu = ETHERMIN;
288 
289 		/*
290 		 * If the parent supports the VLAN_MTU capability,
291 		 * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames,
292 		 * enable it.
293 		 */
294 		if (ec->ec_nvlans++ == 0 &&
295 		    (ec->ec_capabilities & ETHERCAP_VLAN_MTU) != 0) {
296 			/*
297 			 * Enable Tx/Rx of VLAN-sized frames.
298 			 */
299 			ec->ec_capenable |= ETHERCAP_VLAN_MTU;
300 			if (p->if_flags & IFF_UP) {
301 				struct ifreq ifr;
302 
303 				ifr.ifr_flags = p->if_flags;
304 				error = (*p->if_ioctl)(p, SIOCSIFFLAGS,
305 				    (caddr_t) &ifr);
306 				if (error) {
307 					if (ec->ec_nvlans-- == 1)
308 						ec->ec_capenable &=
309 						    ~ETHERCAP_VLAN_MTU;
310 					return (error);
311 				}
312 			}
313 			ifv->ifv_mtufudge = 0;
314 		} else if ((ec->ec_capabilities & ETHERCAP_VLAN_MTU) == 0) {
315 			/*
316 			 * Fudge the MTU by the encapsulation size.  This
317 			 * makes us incompatible with strictly compliant
318 			 * 802.1Q implementations, but allows us to use
319 			 * the feature with other NetBSD implementations,
320 			 * which might still be useful.
321 			 */
322 			ifv->ifv_mtufudge = ifv->ifv_encaplen;
323 		}
324 
325 		/*
326 		 * If the parent interface can do hardware-assisted
327 		 * VLAN encapsulation, then propagate its hardware-
328 		 * assisted checksumming flags.
329 		 */
330 		if (ec->ec_capabilities & ETHERCAP_VLAN_HWTAGGING)
331 			ifp->if_capabilities = p->if_capabilities &
332 			    (IFCAP_CSUM_IPv4_Tx|IFCAP_CSUM_IPv4_Rx|
333 			     IFCAP_CSUM_TCPv4_Tx|IFCAP_CSUM_TCPv4_Rx|
334 			     IFCAP_CSUM_UDPv4_Tx|IFCAP_CSUM_UDPv4_Rx|
335 			     IFCAP_CSUM_TCPv6_Tx|IFCAP_CSUM_TCPv6_Rx|
336 			     IFCAP_CSUM_UDPv6_Tx|IFCAP_CSUM_UDPv6_Rx);
337 
338 		/*
339 		 * We inherit the parent's Ethernet address.
340 		 */
341 		ether_ifattach(ifp, LLADDR(p->if_sadl));
342 		ifp->if_hdrlen = sizeof(struct ether_vlan_header); /* XXX? */
343 		break;
344 	    }
345 
346 	default:
347 		return (EPROTONOSUPPORT);
348 	}
349 
350 	ifv->ifv_p = p;
351 	ifv->ifv_if.if_mtu = p->if_mtu - ifv->ifv_mtufudge;
352 	ifv->ifv_if.if_flags = p->if_flags &
353 	    (IFF_UP | IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
354 
355 	/*
356 	 * Inherit the if_type from the parent.  This allows us
357 	 * to participate in bridges of that type.
358 	 */
359 	ifv->ifv_if.if_type = p->if_type;
360 
361 	return (0);
362 }
363 
364 /*
365  * Unconfigure a VLAN interface.  Must be called at splnet().
366  */
367 static void
368 vlan_unconfig(struct ifnet *ifp)
369 {
370 	struct ifvlan *ifv = ifp->if_softc;
371 
372 	if (ifv->ifv_p == NULL)
373 		return;
374 
375 	/*
376  	 * Since the interface is being unconfigured, we need to empty the
377 	 * list of multicast groups that we may have joined while we were
378 	 * alive and remove them from the parent's list also.
379 	 */
380 	(*ifv->ifv_msw->vmsw_purgemulti)(ifv);
381 
382 	/* Disconnect from parent. */
383 	switch (ifv->ifv_p->if_type) {
384 	case IFT_ETHER:
385 	    {
386 		struct ethercom *ec = (void *) ifv->ifv_p;
387 
388 		if (ec->ec_nvlans-- == 1) {
389 			/*
390 			 * Disable Tx/Rx of VLAN-sized frames.
391 			 */
392 			ec->ec_capenable &= ~ETHERCAP_VLAN_MTU;
393 			if (ifv->ifv_p->if_flags & IFF_UP) {
394 				struct ifreq ifr;
395 
396 				ifr.ifr_flags = ifv->ifv_p->if_flags;
397 				(void) (*ifv->ifv_p->if_ioctl)(ifv->ifv_p,
398 				    SIOCSIFFLAGS, (caddr_t) &ifr);
399 			}
400 		}
401 
402 		ether_ifdetach(ifp);
403 		vlan_reset_linkname(ifp);
404 		break;
405 	    }
406 
407 #ifdef DIAGNOSTIC
408 	default:
409 		panic("vlan_unconfig: impossible");
410 #endif
411 	}
412 
413 	ifv->ifv_p = NULL;
414 	ifv->ifv_if.if_mtu = 0;
415 	ifv->ifv_flags = 0;
416 
417 	if_down(ifp);
418 	ifp->if_flags &= ~(IFF_UP|IFF_RUNNING);
419 	ifp->if_capabilities = 0;
420 }
421 
422 /*
423  * Called when a parent interface is detaching; destroy any VLAN
424  * configuration for the parent interface.
425  */
426 void
427 vlan_ifdetach(struct ifnet *p)
428 {
429 	struct ifvlan *ifv;
430 	int s;
431 
432 	s = splnet();
433 
434 	for (ifv = LIST_FIRST(&ifv_list); ifv != NULL;
435 	     ifv = LIST_NEXT(ifv, ifv_list)) {
436 		if (ifv->ifv_p == p)
437 			vlan_unconfig(&ifv->ifv_if);
438 	}
439 
440 	splx(s);
441 }
442 
443 static int
444 vlan_set_promisc(struct ifnet *ifp)
445 {
446 	struct ifvlan *ifv = ifp->if_softc;
447 	int error = 0;
448 
449 	if ((ifp->if_flags & IFF_PROMISC) != 0) {
450 		if ((ifv->ifv_flags & IFVF_PROMISC) == 0) {
451 			error = ifpromisc(ifv->ifv_p, 1);
452 			if (error == 0)
453 				ifv->ifv_flags |= IFVF_PROMISC;
454 		}
455 	} else {
456 		if ((ifv->ifv_flags & IFVF_PROMISC) != 0) {
457 			error = ifpromisc(ifv->ifv_p, 0);
458 			if (error == 0)
459 				ifv->ifv_flags &= ~IFVF_PROMISC;
460 		}
461 	}
462 
463 	return (error);
464 }
465 
466 static int
467 vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
468 {
469 	struct lwp *l = curlwp;	/* XXX */
470 	struct ifvlan *ifv = ifp->if_softc;
471 	struct ifaddr *ifa = (struct ifaddr *) data;
472 	struct ifreq *ifr = (struct ifreq *) data;
473 	struct ifnet *pr;
474 	struct vlanreq vlr;
475 	struct sockaddr *sa;
476 	int s, error = 0;
477 
478 	s = splnet();
479 
480 	switch (cmd) {
481 	case SIOCSIFADDR:
482 		if (ifv->ifv_p != NULL) {
483 			ifp->if_flags |= IFF_UP;
484 
485 			switch (ifa->ifa_addr->sa_family) {
486 #ifdef INET
487 			case AF_INET:
488 				arp_ifinit(ifp, ifa);
489 				break;
490 #endif
491 			default:
492 				break;
493 			}
494 		} else {
495 			error = EINVAL;
496 		}
497 		break;
498 
499 	case SIOCGIFADDR:
500 		sa = (struct sockaddr *)&ifr->ifr_data;
501 		memcpy(sa->sa_data, LLADDR(ifp->if_sadl), ifp->if_addrlen);
502 		break;
503 
504 	case SIOCSIFMTU:
505 		if (ifv->ifv_p != NULL) {
506 			if (ifr->ifr_mtu >
507 			     (ifv->ifv_p->if_mtu - ifv->ifv_mtufudge) ||
508 			    ifr->ifr_mtu <
509 			     (ifv->ifv_mintu - ifv->ifv_mtufudge))
510 				error = EINVAL;
511 			else
512 				ifp->if_mtu = ifr->ifr_mtu;
513 		} else
514 			error = EINVAL;
515 		break;
516 
517 	case SIOCSETVLAN:
518 		if ((error = kauth_authorize_generic(l->l_cred,
519 		    KAUTH_GENERIC_ISSUSER, &l->l_acflag)) != 0)
520 			break;
521 		if ((error = copyin(ifr->ifr_data, &vlr, sizeof(vlr))) != 0)
522 			break;
523 		if (vlr.vlr_parent[0] == '\0') {
524 			vlan_unconfig(ifp);
525 			break;
526 		}
527 		if (vlr.vlr_tag != EVL_VLANOFTAG(vlr.vlr_tag)) {
528 			error = EINVAL;		 /* check for valid tag */
529 			break;
530 		}
531 		if ((pr = ifunit(vlr.vlr_parent)) == 0) {
532 			error = ENOENT;
533 			break;
534 		}
535 		if ((error = vlan_config(ifv, pr)) != 0)
536 			break;
537 		ifv->ifv_tag = vlr.vlr_tag;
538 		ifp->if_flags |= IFF_RUNNING;
539 
540 		/* Update promiscuous mode, if necessary. */
541 		vlan_set_promisc(ifp);
542 		break;
543 
544 	case SIOCGETVLAN:
545 		memset(&vlr, 0, sizeof(vlr));
546 		if (ifv->ifv_p != NULL) {
547 			snprintf(vlr.vlr_parent, sizeof(vlr.vlr_parent), "%s",
548 			    ifv->ifv_p->if_xname);
549 			vlr.vlr_tag = ifv->ifv_tag;
550 		}
551 		error = copyout(&vlr, ifr->ifr_data, sizeof(vlr));
552 		break;
553 
554 	case SIOCSIFFLAGS:
555 		/*
556 		 * For promiscuous mode, we enable promiscuous mode on
557 		 * the parent if we need promiscuous on the VLAN interface.
558 		 */
559 		if (ifv->ifv_p != NULL)
560 			error = vlan_set_promisc(ifp);
561 		break;
562 
563 	case SIOCADDMULTI:
564 		error = (ifv->ifv_p != NULL) ?
565 		    (*ifv->ifv_msw->vmsw_addmulti)(ifv, ifr) : EINVAL;
566 		break;
567 
568 	case SIOCDELMULTI:
569 		error = (ifv->ifv_p != NULL) ?
570 		    (*ifv->ifv_msw->vmsw_delmulti)(ifv, ifr) : EINVAL;
571 		break;
572 
573 	default:
574 		error = EINVAL;
575 	}
576 
577 	splx(s);
578 
579 	return (error);
580 }
581 
582 static int
583 vlan_ether_addmulti(struct ifvlan *ifv, struct ifreq *ifr)
584 {
585 	struct vlan_mc_entry *mc;
586 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
587 	int error;
588 
589 	if (ifr->ifr_addr.sa_len > sizeof(struct sockaddr_storage))
590 		return (EINVAL);
591 
592 	error = ether_addmulti(ifr, &ifv->ifv_ec);
593 	if (error != ENETRESET)
594 		return (error);
595 
596 	/*
597 	 * This is new multicast address.  We have to tell parent
598 	 * about it.  Also, remember this multicast address so that
599 	 * we can delete them on unconfigure.
600 	 */
601 	MALLOC(mc, struct vlan_mc_entry *, sizeof(struct vlan_mc_entry),
602 	    M_DEVBUF, M_NOWAIT);
603 	if (mc == NULL) {
604 		error = ENOMEM;
605 		goto alloc_failed;
606 	}
607 
608 	/*
609 	 * As ether_addmulti() returns ENETRESET, following two
610 	 * statement shouldn't fail.
611 	 */
612 	(void)ether_multiaddr(&ifr->ifr_addr, addrlo, addrhi);
613 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &ifv->ifv_ec, mc->mc_enm);
614 	memcpy(&mc->mc_addr, &ifr->ifr_addr, ifr->ifr_addr.sa_len);
615 	LIST_INSERT_HEAD(&ifv->ifv_mc_listhead, mc, mc_entries);
616 
617 	error = (*ifv->ifv_p->if_ioctl)(ifv->ifv_p, SIOCADDMULTI,
618 	    (caddr_t)ifr);
619 	if (error != 0)
620 		goto ioctl_failed;
621 	return (error);
622 
623  ioctl_failed:
624 	LIST_REMOVE(mc, mc_entries);
625 	FREE(mc, M_DEVBUF);
626  alloc_failed:
627 	(void)ether_delmulti(ifr, &ifv->ifv_ec);
628 	return (error);
629 }
630 
631 static int
632 vlan_ether_delmulti(struct ifvlan *ifv, struct ifreq *ifr)
633 {
634 	struct ether_multi *enm;
635 	struct vlan_mc_entry *mc;
636 	u_int8_t addrlo[ETHER_ADDR_LEN], addrhi[ETHER_ADDR_LEN];
637 	int error;
638 
639 	/*
640 	 * Find a key to lookup vlan_mc_entry.  We have to do this
641 	 * before calling ether_delmulti for obvious reason.
642 	 */
643 	if ((error = ether_multiaddr(&ifr->ifr_addr, addrlo, addrhi)) != 0)
644 		return (error);
645 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &ifv->ifv_ec, enm);
646 
647 	error = ether_delmulti(ifr, &ifv->ifv_ec);
648 	if (error != ENETRESET)
649 		return (error);
650 
651 	/* We no longer use this multicast address.  Tell parent so. */
652 	error = (*ifv->ifv_p->if_ioctl)(ifv->ifv_p, SIOCDELMULTI,
653 	    (caddr_t)ifr);
654 	if (error == 0) {
655 		/* And forget about this address. */
656 		for (mc = LIST_FIRST(&ifv->ifv_mc_listhead); mc != NULL;
657 		    mc = LIST_NEXT(mc, mc_entries)) {
658 			if (mc->mc_enm == enm) {
659 				LIST_REMOVE(mc, mc_entries);
660 				FREE(mc, M_DEVBUF);
661 				break;
662 			}
663 		}
664 		KASSERT(mc != NULL);
665 	} else
666 		(void)ether_addmulti(ifr, &ifv->ifv_ec);
667 	return (error);
668 }
669 
670 /*
671  * Delete any multicast address we have asked to add from parent
672  * interface.  Called when the vlan is being unconfigured.
673  */
674 static void
675 vlan_ether_purgemulti(struct ifvlan *ifv)
676 {
677 	struct ifnet *ifp = ifv->ifv_p;		/* Parent. */
678 	struct vlan_mc_entry *mc;
679 	union {
680 		struct ifreq ifreq;
681 		struct {
682 			char ifr_name[IFNAMSIZ];
683 			struct sockaddr_storage ifr_ss;
684 		} ifreq_storage;
685 	} ifreq;
686 	struct ifreq *ifr = &ifreq.ifreq;
687 
688 	memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
689 	while ((mc = LIST_FIRST(&ifv->ifv_mc_listhead)) != NULL) {
690 		memcpy(&ifr->ifr_addr, &mc->mc_addr, mc->mc_addr.ss_len);
691 		(void)(*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)ifr);
692 		LIST_REMOVE(mc, mc_entries);
693 		FREE(mc, M_DEVBUF);
694 	}
695 }
696 
697 static void
698 vlan_start(struct ifnet *ifp)
699 {
700 	struct ifvlan *ifv = ifp->if_softc;
701 	struct ifnet *p = ifv->ifv_p;
702 	struct ethercom *ec = (void *) ifv->ifv_p;
703 	struct mbuf *m;
704 	int error;
705 	ALTQ_DECL(struct altq_pktattr pktattr;)
706 
707 	ifp->if_flags |= IFF_OACTIVE;
708 
709 	for (;;) {
710 		IFQ_DEQUEUE(&ifp->if_snd, m);
711 		if (m == NULL)
712 			break;
713 
714 #ifdef ALTQ
715 		/*
716 		 * If ALTQ is enabled on the parent interface, do
717 		 * classification; the queueing discipline might
718 		 * not require classification, but might require
719 		 * the address family/header pointer in the pktattr.
720 		 */
721 		if (ALTQ_IS_ENABLED(&p->if_snd)) {
722 			switch (p->if_type) {
723 			case IFT_ETHER:
724 				altq_etherclassify(&p->if_snd, m, &pktattr);
725 				break;
726 #ifdef DIAGNOSTIC
727 			default:
728 				panic("vlan_start: impossible (altq)");
729 #endif
730 			}
731 		}
732 #endif /* ALTQ */
733 
734 #if NBPFILTER > 0
735 		if (ifp->if_bpf)
736 			bpf_mtap(ifp->if_bpf, m);
737 #endif
738 		/*
739 		 * If the parent can insert the tag itself, just mark
740 		 * the tag in the mbuf header.
741 		 */
742 		if (ec->ec_capabilities & ETHERCAP_VLAN_HWTAGGING) {
743 			struct m_tag *mtag;
744 
745 			mtag = m_tag_get(PACKET_TAG_VLAN, sizeof(u_int),
746 			    M_NOWAIT);
747 			if (mtag == NULL) {
748 				ifp->if_oerrors++;
749 				m_freem(m);
750 				continue;
751 			}
752 			*(u_int *)(mtag + 1) = ifv->ifv_tag;
753 			m_tag_prepend(m, mtag);
754 		} else {
755 			/*
756 			 * insert the tag ourselves
757 			 */
758 			M_PREPEND(m, ifv->ifv_encaplen, M_DONTWAIT);
759 			if (m == NULL) {
760 				printf("%s: unable to prepend encap header",
761 				    ifv->ifv_p->if_xname);
762 				ifp->if_oerrors++;
763 				continue;
764 			}
765 
766 			switch (p->if_type) {
767 			case IFT_ETHER:
768 			    {
769 				struct ether_vlan_header *evl;
770 
771 				if (m->m_len < sizeof(struct ether_vlan_header))
772 					m = m_pullup(m,
773 					    sizeof(struct ether_vlan_header));
774 				if (m == NULL) {
775 					printf("%s: unable to pullup encap "
776 					    "header", ifv->ifv_p->if_xname);
777 					ifp->if_oerrors++;
778 					continue;
779 				}
780 
781 				/*
782 				 * Transform the Ethernet header into an
783 				 * Ethernet header with 802.1Q encapsulation.
784 				 */
785 				memmove(mtod(m, caddr_t),
786 				    mtod(m, caddr_t) + ifv->ifv_encaplen,
787 				    sizeof(struct ether_header));
788 				evl = mtod(m, struct ether_vlan_header *);
789 				evl->evl_proto = evl->evl_encap_proto;
790 				evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
791 				evl->evl_tag = htons(ifv->ifv_tag);
792 
793 				/*
794 				 * To cater for VLAN-aware layer 2 ethernet
795 				 * switches which may need to strip the tag
796 				 * before forwarding the packet, make sure
797 				 * the packet+tag is at least 68 bytes long.
798 				 * This is necessary because our parent will
799 				 * only pad to 64 bytes (ETHER_MIN_LEN) and
800 				 * some switches will not pad by themselves
801 				 * after deleting a tag.
802 				 */
803 				if (m->m_pkthdr.len <
804 				    (ETHER_MIN_LEN + ETHER_VLAN_ENCAP_LEN)) {
805 					m_copyback(m, m->m_pkthdr.len,
806 					    (ETHER_MIN_LEN +
807 					     ETHER_VLAN_ENCAP_LEN) -
808 					     m->m_pkthdr.len,
809 					    vlan_zero_pad_buff);
810 				}
811 				break;
812 			    }
813 
814 #ifdef DIAGNOSTIC
815 			default:
816 				panic("vlan_start: impossible");
817 #endif
818 			}
819 		}
820 
821 		/*
822 		 * Send it, precisely as the parent's output routine
823 		 * would have.  We are already running at splnet.
824 		 */
825 		IFQ_ENQUEUE(&p->if_snd, m, &pktattr, error);
826 		if (error) {
827 			/* mbuf is already freed */
828 			ifp->if_oerrors++;
829 			continue;
830 		}
831 
832 		ifp->if_opackets++;
833 		if ((p->if_flags & (IFF_RUNNING|IFF_OACTIVE)) == IFF_RUNNING)
834 			(*p->if_start)(p);
835 	}
836 
837 	ifp->if_flags &= ~IFF_OACTIVE;
838 }
839 
840 /*
841  * Given an Ethernet frame, find a valid vlan interface corresponding to the
842  * given source interface and tag, then run the real packet through the
843  * parent's input routine.
844  */
845 void
846 vlan_input(struct ifnet *ifp, struct mbuf *m)
847 {
848 	struct ifvlan *ifv;
849 	u_int tag;
850 	struct m_tag *mtag;
851 
852 	mtag = m_tag_find(m, PACKET_TAG_VLAN, NULL);
853 	if (mtag != NULL) {
854 		/* m contains a normal ethernet frame, the tag is in mtag */
855 		tag = EVL_VLANOFTAG(*(u_int *)(mtag + 1));
856 		m_tag_delete(m, mtag);
857 	} else {
858 		switch (ifp->if_type) {
859 		case IFT_ETHER:
860 		    {
861 			struct ether_vlan_header *evl;
862 
863 			if (m->m_len < sizeof(struct ether_vlan_header) &&
864 			    (m = m_pullup(m,
865 			     sizeof(struct ether_vlan_header))) == NULL) {
866 				printf("%s: no memory for VLAN header, "
867 				    "dropping packet.\n", ifp->if_xname);
868 				return;
869 			}
870 			evl = mtod(m, struct ether_vlan_header *);
871 			KASSERT(ntohs(evl->evl_encap_proto) == ETHERTYPE_VLAN);
872 
873 			tag = EVL_VLANOFTAG(ntohs(evl->evl_tag));
874 
875 			/*
876 			 * Restore the original ethertype.  We'll remove
877 			 * the encapsulation after we've found the vlan
878 			 * interface corresponding to the tag.
879 			 */
880 			evl->evl_encap_proto = evl->evl_proto;
881 			break;
882 		    }
883 
884 		default:
885 			tag = (u_int) -1;	/* XXX GCC */
886 #ifdef DIAGNOSTIC
887 			panic("vlan_input: impossible");
888 #endif
889 		}
890 	}
891 
892 	for (ifv = LIST_FIRST(&ifv_list); ifv != NULL;
893 	    ifv = LIST_NEXT(ifv, ifv_list))
894 		if (ifp == ifv->ifv_p && tag == ifv->ifv_tag)
895 			break;
896 
897 	if (ifv == NULL ||
898 	    (ifv->ifv_if.if_flags & (IFF_UP|IFF_RUNNING)) !=
899 	     (IFF_UP|IFF_RUNNING)) {
900 		m_freem(m);
901 		ifp->if_noproto++;
902 		return;
903 	}
904 
905 	/*
906 	 * Now, remove the encapsulation header.  The original
907 	 * header has already been fixed up above.
908 	 */
909 	if (mtag == NULL) {
910 		memmove(mtod(m, caddr_t) + ifv->ifv_encaplen,
911 		    mtod(m, caddr_t), sizeof(struct ether_header));
912 		m_adj(m, ifv->ifv_encaplen);
913 	}
914 
915 	m->m_pkthdr.rcvif = &ifv->ifv_if;
916 	ifv->ifv_if.if_ipackets++;
917 
918 #if NBPFILTER > 0
919 	if (ifv->ifv_if.if_bpf)
920 		bpf_mtap(ifv->ifv_if.if_bpf, m);
921 #endif
922 
923 	/* Pass it back through the parent's input routine. */
924 	(*ifp->if_input)(&ifv->ifv_if, m);
925 }
926