xref: /freebsd/sys/netgraph/ng_vlan.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2003 IPNET Internet Communication Company
5  * Copyright (c) 2011 - 2012 Rozhuk Ivan <rozhuk.im@gmail.com>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * Author: Ruslan Ermilov <ru@FreeBSD.org>
30  */
31 
32 #include <sys/param.h>
33 #include <sys/errno.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/mbuf.h>
37 #include <sys/queue.h>
38 #include <sys/socket.h>
39 #include <sys/systm.h>
40 
41 #include <net/ethernet.h>
42 #include <net/if.h>
43 #include <net/if_vlan_var.h>
44 
45 #include <netgraph/ng_message.h>
46 #include <netgraph/ng_parse.h>
47 #include <netgraph/ng_vlan.h>
48 #include <netgraph/netgraph.h>
49 
50 struct ng_vlan_private {
51 	hook_p		downstream_hook;
52 	hook_p		nomatch_hook;
53 	uint32_t	decap_enable;
54 	uint32_t	encap_enable;
55 	uint16_t	encap_proto;
56 	hook_p		vlan_hook[(EVL_VLID_MASK + 1)];
57 };
58 typedef struct ng_vlan_private *priv_p;
59 
60 #define	ETHER_VLAN_HDR_LEN (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN)
61 #define	VLAN_TAG_MASK	0xFFFF
62 #define	HOOK_VLAN_TAG_SET_MASK ((uintptr_t)((~0) & ~(VLAN_TAG_MASK)))
63 #define	IS_HOOK_VLAN_SET(hdata) \
64 	    ((((uintptr_t)hdata) & HOOK_VLAN_TAG_SET_MASK) == HOOK_VLAN_TAG_SET_MASK)
65 
66 static ng_constructor_t	ng_vlan_constructor;
67 static ng_rcvmsg_t	ng_vlan_rcvmsg;
68 static ng_shutdown_t	ng_vlan_shutdown;
69 static ng_newhook_t	ng_vlan_newhook;
70 static ng_rcvdata_t	ng_vlan_rcvdata;
71 static ng_disconnect_t	ng_vlan_disconnect;
72 
73 /* Parse type for struct ng_vlan_filter. */
74 static const struct ng_parse_struct_field ng_vlan_filter_fields[] =
75 	NG_VLAN_FILTER_FIELDS;
76 static const struct ng_parse_type ng_vlan_filter_type = {
77 	&ng_parse_struct_type,
78 	&ng_vlan_filter_fields
79 };
80 
81 static int
82 ng_vlan_getTableLength(const struct ng_parse_type *type,
83     const u_char *start, const u_char *buf)
84 {
85 	const struct ng_vlan_table *const table =
86 	    (const struct ng_vlan_table *)(buf - sizeof(u_int32_t));
87 
88 	return table->n;
89 }
90 
91 /* Parse type for struct ng_vlan_table. */
92 static const struct ng_parse_array_info ng_vlan_table_array_info = {
93 	&ng_vlan_filter_type,
94 	ng_vlan_getTableLength
95 };
96 static const struct ng_parse_type ng_vlan_table_array_type = {
97 	&ng_parse_array_type,
98 	&ng_vlan_table_array_info
99 };
100 static const struct ng_parse_struct_field ng_vlan_table_fields[] =
101 	NG_VLAN_TABLE_FIELDS;
102 static const struct ng_parse_type ng_vlan_table_type = {
103 	&ng_parse_struct_type,
104 	&ng_vlan_table_fields
105 };
106 
107 /* List of commands and how to convert arguments to/from ASCII. */
108 static const struct ng_cmdlist ng_vlan_cmdlist[] = {
109 	{
110 	  NGM_VLAN_COOKIE,
111 	  NGM_VLAN_ADD_FILTER,
112 	  "addfilter",
113 	  &ng_vlan_filter_type,
114 	  NULL
115 	},
116 	{
117 	  NGM_VLAN_COOKIE,
118 	  NGM_VLAN_DEL_FILTER,
119 	  "delfilter",
120 	  &ng_parse_hookbuf_type,
121 	  NULL
122 	},
123 	{
124 	  NGM_VLAN_COOKIE,
125 	  NGM_VLAN_GET_TABLE,
126 	  "gettable",
127 	  NULL,
128 	  &ng_vlan_table_type
129 	},
130 	{
131 	  NGM_VLAN_COOKIE,
132 	  NGM_VLAN_DEL_VID_FLT,
133 	  "delvidflt",
134 	  &ng_parse_uint16_type,
135 	  NULL
136 	},
137 	{
138 	  NGM_VLAN_COOKIE,
139 	  NGM_VLAN_GET_DECAP,
140 	  "getdecap",
141 	  NULL,
142 	  &ng_parse_hint32_type
143 	},
144 	{
145 	  NGM_VLAN_COOKIE,
146 	  NGM_VLAN_SET_DECAP,
147 	  "setdecap",
148 	  &ng_parse_hint32_type,
149 	  NULL
150 	},
151 	{
152 	  NGM_VLAN_COOKIE,
153 	  NGM_VLAN_GET_ENCAP,
154 	  "getencap",
155 	  NULL,
156 	  &ng_parse_hint32_type
157 	},
158 	{
159 	  NGM_VLAN_COOKIE,
160 	  NGM_VLAN_SET_ENCAP,
161 	  "setencap",
162 	  &ng_parse_hint32_type,
163 	  NULL
164 	},
165 	{
166 	  NGM_VLAN_COOKIE,
167 	  NGM_VLAN_GET_ENCAP_PROTO,
168 	  "getencapproto",
169 	  NULL,
170 	  &ng_parse_hint16_type
171 	},
172 	{
173 	  NGM_VLAN_COOKIE,
174 	  NGM_VLAN_SET_ENCAP_PROTO,
175 	  "setencapproto",
176 	  &ng_parse_hint16_type,
177 	  NULL
178 	},
179 	{ 0 }
180 };
181 
182 static struct ng_type ng_vlan_typestruct = {
183 	.version =	NG_ABI_VERSION,
184 	.name =		NG_VLAN_NODE_TYPE,
185 	.constructor =	ng_vlan_constructor,
186 	.rcvmsg =	ng_vlan_rcvmsg,
187 	.shutdown =	ng_vlan_shutdown,
188 	.newhook =	ng_vlan_newhook,
189 	.rcvdata =	ng_vlan_rcvdata,
190 	.disconnect =	ng_vlan_disconnect,
191 	.cmdlist =	ng_vlan_cmdlist,
192 };
193 NETGRAPH_INIT(vlan, &ng_vlan_typestruct);
194 
195 /*
196  * Helper functions.
197  */
198 
199 static __inline int
200 m_chk(struct mbuf **mp, int len)
201 {
202 
203 	if ((*mp)->m_pkthdr.len < len) {
204 		m_freem((*mp));
205 		(*mp) = NULL;
206 		return (EINVAL);
207 	}
208 	if ((*mp)->m_len < len && ((*mp) = m_pullup((*mp), len)) == NULL)
209 		return (ENOBUFS);
210 
211 	return (0);
212 }
213 
214 /*
215  * Netgraph node functions.
216  */
217 
218 static int
219 ng_vlan_constructor(node_p node)
220 {
221 	priv_p priv;
222 
223 	priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
224 	priv->decap_enable = 0;
225 	priv->encap_enable = VLAN_ENCAP_FROM_FILTER;
226 	priv->encap_proto = htons(ETHERTYPE_VLAN);
227 	NG_NODE_SET_PRIVATE(node, priv);
228 	return (0);
229 }
230 
231 static int
232 ng_vlan_newhook(node_p node, hook_p hook, const char *name)
233 {
234 	const priv_p priv = NG_NODE_PRIVATE(node);
235 
236 	if (strcmp(name, NG_VLAN_HOOK_DOWNSTREAM) == 0)
237 		priv->downstream_hook = hook;
238 	else if (strcmp(name, NG_VLAN_HOOK_NOMATCH) == 0)
239 		priv->nomatch_hook = hook;
240 	else {
241 		/*
242 		 * Any other hook name is valid and can
243 		 * later be associated with a filter rule.
244 		 */
245 	}
246 	NG_HOOK_SET_PRIVATE(hook, NULL);
247 	return (0);
248 }
249 
250 static int
251 ng_vlan_rcvmsg(node_p node, item_p item, hook_p lasthook)
252 {
253 	const priv_p priv = NG_NODE_PRIVATE(node);
254 	struct ng_mesg *msg, *resp = NULL;
255 	struct ng_vlan_filter *vf;
256 	hook_p hook;
257 	struct ng_vlan_table *t;
258 	uintptr_t hook_data;
259 	int i, vlan_count;
260 	uint16_t vid;
261 	int error = 0;
262 
263 	NGI_GET_MSG(item, msg);
264 	/* Deal with message according to cookie and command. */
265 	switch (msg->header.typecookie) {
266 	case NGM_VLAN_COOKIE:
267 		switch (msg->header.cmd) {
268 		case NGM_VLAN_ADD_FILTER:
269 			/* Check that message is long enough. */
270 			if (msg->header.arglen != sizeof(*vf)) {
271 				error = EINVAL;
272 				break;
273 			}
274 			vf = (struct ng_vlan_filter *)msg->data;
275 			/* Sanity check the VLAN ID value. */
276 #ifdef	NG_VLAN_USE_OLD_VLAN_NAME
277 			if (vf->vid == 0 && vf->vid != vf->vlan) {
278 				vf->vid = vf->vlan;
279 			} else if (vf->vid != 0 && vf->vlan != 0 &&
280 			    vf->vid != vf->vlan) {
281 				error = EINVAL;
282 				break;
283 			}
284 #endif
285 			if (vf->vid & ~EVL_VLID_MASK ||
286 			    vf->pcp & ~7 ||
287 			    vf->cfi & ~1) {
288 				error = EINVAL;
289 				break;
290 			}
291 			/* Check that a referenced hook exists. */
292 			hook = ng_findhook(node, vf->hook_name);
293 			if (hook == NULL) {
294 				error = ENOENT;
295 				break;
296 			}
297 			/* And is not one of the special hooks. */
298 			if (hook == priv->downstream_hook ||
299 			    hook == priv->nomatch_hook) {
300 				error = EINVAL;
301 				break;
302 			}
303 			/* And is not already in service. */
304 			if (IS_HOOK_VLAN_SET(NG_HOOK_PRIVATE(hook))) {
305 				error = EEXIST;
306 				break;
307 			}
308 			/* Check we don't already trap this VLAN. */
309 			if (priv->vlan_hook[vf->vid] != NULL) {
310 				error = EEXIST;
311 				break;
312 			}
313 			/* Link vlan and hook together. */
314 			NG_HOOK_SET_PRIVATE(hook,
315 			    (void *)(HOOK_VLAN_TAG_SET_MASK |
316 			    EVL_MAKETAG(vf->vid, vf->pcp, vf->cfi)));
317 			priv->vlan_hook[vf->vid] = hook;
318 			break;
319 		case NGM_VLAN_DEL_FILTER:
320 			/* Check that message is long enough. */
321 			if (msg->header.arglen != NG_HOOKSIZ) {
322 				error = EINVAL;
323 				break;
324 			}
325 			/* Check that hook exists and is active. */
326 			hook = ng_findhook(node, (char *)msg->data);
327 			if (hook == NULL) {
328 				error = ENOENT;
329 				break;
330 			}
331 			hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
332 			if (IS_HOOK_VLAN_SET(hook_data) == 0) {
333 				error = ENOENT;
334 				break;
335 			}
336 
337 			KASSERT(priv->vlan_hook[EVL_VLANOFTAG(hook_data)] == hook,
338 			    ("%s: NGM_VLAN_DEL_FILTER: Invalid VID for Hook = %s\n",
339 			    __func__, (char *)msg->data));
340 
341 			/* Purge a rule that refers to this hook. */
342 			priv->vlan_hook[EVL_VLANOFTAG(hook_data)] = NULL;
343 			NG_HOOK_SET_PRIVATE(hook, NULL);
344 			break;
345 		case NGM_VLAN_DEL_VID_FLT:
346 			/* Check that message is long enough. */
347 			if (msg->header.arglen != sizeof(uint16_t)) {
348 				error = EINVAL;
349 				break;
350 			}
351 			vid = (*((uint16_t *)msg->data));
352 			/* Sanity check the VLAN ID value. */
353 			if (vid & ~EVL_VLID_MASK) {
354 				error = EINVAL;
355 				break;
356 			}
357 			/* Check that hook exists and is active. */
358 			hook = priv->vlan_hook[vid];
359 			if (hook == NULL) {
360 				error = ENOENT;
361 				break;
362 			}
363 			hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
364 			if (IS_HOOK_VLAN_SET(hook_data) == 0) {
365 				error = ENOENT;
366 				break;
367 			}
368 
369 			KASSERT(EVL_VLANOFTAG(hook_data) == vid,
370 			    ("%s: NGM_VLAN_DEL_VID_FLT:"
371 			    " Invalid VID Hook = %us, must be: %us\n",
372 			    __func__, (uint16_t )EVL_VLANOFTAG(hook_data),
373 			    vid));
374 
375 			/* Purge a rule that refers to this hook. */
376 			priv->vlan_hook[vid] = NULL;
377 			NG_HOOK_SET_PRIVATE(hook, NULL);
378 			break;
379 		case NGM_VLAN_GET_TABLE:
380 			/* Calculate vlans. */
381 			vlan_count = 0;
382 			for (i = 0; i < (EVL_VLID_MASK + 1); i ++) {
383 				if (priv->vlan_hook[i] != NULL &&
384 				    NG_HOOK_IS_VALID(priv->vlan_hook[i]))
385 					vlan_count ++;
386 			}
387 
388 			/* Allocate memory for response. */
389 			NG_MKRESPONSE(resp, msg, sizeof(*t) +
390 			    vlan_count * sizeof(*t->filter), M_NOWAIT);
391 			if (resp == NULL) {
392 				error = ENOMEM;
393 				break;
394 			}
395 
396 			/* Pack data to response. */
397 			t = (struct ng_vlan_table *)resp->data;
398 			t->n = 0;
399 			vf = &t->filter[0];
400 			for (i = 0; i < (EVL_VLID_MASK + 1); i ++) {
401 				hook = priv->vlan_hook[i];
402 				if (hook == NULL || NG_HOOK_NOT_VALID(hook))
403 					continue;
404 				hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
405 				if (IS_HOOK_VLAN_SET(hook_data) == 0)
406 					continue;
407 
408 				KASSERT(EVL_VLANOFTAG(hook_data) == i,
409 				    ("%s: NGM_VLAN_GET_TABLE:"
410 				    " hook %s VID = %us, must be: %i\n",
411 				    __func__, NG_HOOK_NAME(hook),
412 				    (uint16_t)EVL_VLANOFTAG(hook_data), i));
413 
414 #ifdef	NG_VLAN_USE_OLD_VLAN_NAME
415 				vf->vlan = i;
416 #endif
417 				vf->vid = i;
418 				vf->pcp = EVL_PRIOFTAG(hook_data);
419 				vf->cfi = EVL_CFIOFTAG(hook_data);
420 				strncpy(vf->hook_name,
421 				    NG_HOOK_NAME(hook), NG_HOOKSIZ);
422 				vf ++;
423 				t->n ++;
424 			}
425 			break;
426 		case NGM_VLAN_GET_DECAP:
427 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
428 			if (resp == NULL) {
429 				error = ENOMEM;
430 				break;
431 			}
432 			(*((uint32_t *)resp->data)) = priv->decap_enable;
433 			break;
434 		case NGM_VLAN_SET_DECAP:
435 			if (msg->header.arglen != sizeof(uint32_t)) {
436 				error = EINVAL;
437 				break;
438 			}
439 			priv->decap_enable = (*((uint32_t *)msg->data));
440 			break;
441 		case NGM_VLAN_GET_ENCAP:
442 			NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
443 			if (resp == NULL) {
444 				error = ENOMEM;
445 				break;
446 			}
447 			(*((uint32_t *)resp->data)) = priv->encap_enable;
448 			break;
449 		case NGM_VLAN_SET_ENCAP:
450 			if (msg->header.arglen != sizeof(uint32_t)) {
451 				error = EINVAL;
452 				break;
453 			}
454 			priv->encap_enable = (*((uint32_t *)msg->data));
455 			break;
456 		case NGM_VLAN_GET_ENCAP_PROTO:
457 			NG_MKRESPONSE(resp, msg, sizeof(uint16_t), M_NOWAIT);
458 			if (resp == NULL) {
459 				error = ENOMEM;
460 				break;
461 			}
462 			(*((uint16_t *)resp->data)) = ntohs(priv->encap_proto);
463 			break;
464 		case NGM_VLAN_SET_ENCAP_PROTO:
465 			if (msg->header.arglen != sizeof(uint16_t)) {
466 				error = EINVAL;
467 				break;
468 			}
469 			priv->encap_proto = htons((*((uint16_t *)msg->data)));
470 			break;
471 		default: /* Unknown command. */
472 			error = EINVAL;
473 			break;
474 		}
475 		break;
476 	case NGM_FLOW_COOKIE:
477 	    {
478 		struct ng_mesg *copy;
479 
480 		/*
481 		 * Flow control messages should come only
482 		 * from downstream.
483 		 */
484 
485 		if (lasthook == NULL)
486 			break;
487 		if (lasthook != priv->downstream_hook)
488 			break;
489 		/* Broadcast the event to all uplinks. */
490 		for (i = 0; i < (EVL_VLID_MASK + 1); i ++) {
491 			if (priv->vlan_hook[i] == NULL)
492 				continue;
493 
494 			NG_COPYMESSAGE(copy, msg, M_NOWAIT);
495 			if (copy == NULL)
496 				continue;
497 			NG_SEND_MSG_HOOK(error, node, copy,
498 			    priv->vlan_hook[i], 0);
499 		}
500 		break;
501 	    }
502 	default: /* Unknown type cookie. */
503 		error = EINVAL;
504 		break;
505 	}
506 	NG_RESPOND_MSG(error, node, item, resp);
507 	NG_FREE_MSG(msg);
508 	return (error);
509 }
510 
511 static int
512 ng_vlan_rcvdata(hook_p hook, item_p item)
513 {
514 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
515 	struct ether_header *eh;
516 	struct ether_vlan_header *evl;
517 	int error;
518 	uintptr_t hook_data;
519 	uint16_t vid, eth_vtag;
520 	struct mbuf *m;
521 	hook_p dst_hook;
522 
523 	NGI_GET_M(item, m);
524 
525 	/* Make sure we have an entire header. */
526 	error = m_chk(&m, ETHER_HDR_LEN);
527 	if (error != 0)
528 		goto mchk_err;
529 
530 	eh = mtod(m, struct ether_header *);
531 	if (hook == priv->downstream_hook) {
532 		/*
533 		 * If from downstream, select between a match hook
534 		 * or the nomatch hook.
535 		 */
536 
537 		dst_hook = priv->nomatch_hook;
538 
539 		/* Skip packets without tag. */
540 		if ((m->m_flags & M_VLANTAG) == 0 &&
541 		    eh->ether_type != priv->encap_proto) {
542 			if (dst_hook == NULL)
543 				goto net_down;
544 			goto send_packet;
545 		}
546 
547 		/* Process packets with tag. */
548 		if (m->m_flags & M_VLANTAG) {
549 			/*
550 			 * Packet is tagged, m contains a normal
551 			 * Ethernet frame; tag is stored out-of-band.
552 			 */
553 			evl = NULL;
554 			vid = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
555 		} else { /* eh->ether_type == priv->encap_proto */
556 			error = m_chk(&m, ETHER_VLAN_HDR_LEN);
557 			if (error != 0)
558 				goto mchk_err;
559 			evl = mtod(m, struct ether_vlan_header *);
560 			vid = EVL_VLANOFTAG(ntohs(evl->evl_tag));
561 		}
562 
563 		if (priv->vlan_hook[vid] != NULL) {
564 			/*
565 			 * VLAN filter: always remove vlan tags and
566 			 * decapsulate packet.
567 			 */
568 			dst_hook = priv->vlan_hook[vid];
569 			if (evl == NULL) { /* m->m_flags & M_VLANTAG */
570 				m->m_pkthdr.ether_vtag = 0;
571 				m->m_flags &= ~M_VLANTAG;
572 				goto send_packet;
573 			}
574 		} else { /* nomatch_hook */
575 			if (dst_hook == NULL)
576 				goto net_down;
577 			if (evl == NULL || priv->decap_enable == 0)
578 				goto send_packet;
579 			/* Save tag out-of-band. */
580 			m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag);
581 			m->m_flags |= M_VLANTAG;
582 		}
583 
584 		/*
585 		 * Decapsulate:
586 		 * TPID = ether type encap
587 		 * Move DstMAC and SrcMAC to ETHER_TYPE.
588 		 * Before:
589 		 *  [dmac] [smac] [TPID] [PCP/CFI/VID] [ether_type] [payload]
590 		 *  |-----------| >>>>>>>>>>>>>>>>>>>> |--------------------|
591 		 * After:
592 		 *  [free space ] [dmac] [smac] [ether_type] [payload]
593 		 *                |-----------| |--------------------|
594 		 */
595 		bcopy((char *)evl, ((char *)evl + ETHER_VLAN_ENCAP_LEN),
596 		    (ETHER_ADDR_LEN * 2));
597 		m_adj(m, ETHER_VLAN_ENCAP_LEN);
598 	} else {
599 		/*
600 		 * It is heading towards the downstream.
601 		 * If from nomatch, pass it unmodified.
602 		 * Otherwise, do the VLAN encapsulation.
603 		 */
604 		dst_hook = priv->downstream_hook;
605 		if (dst_hook == NULL)
606 			goto net_down;
607 		if (hook != priv->nomatch_hook) {/* Filter hook. */
608 			hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
609 			if (IS_HOOK_VLAN_SET(hook_data) == 0) {
610 				/*
611 				 * Packet from hook not in filter
612 				 * call addfilter for this hook to fix.
613 				 */
614 				error = EOPNOTSUPP;
615 				goto drop;
616 			}
617 			eth_vtag = (hook_data & VLAN_TAG_MASK);
618 			if ((priv->encap_enable & VLAN_ENCAP_FROM_FILTER) == 0) {
619 				/* Just set packet header tag and send. */
620 				m->m_flags |= M_VLANTAG;
621 				m->m_pkthdr.ether_vtag = eth_vtag;
622 				goto send_packet;
623 			}
624 		} else { /* nomatch_hook */
625 			if ((priv->encap_enable & VLAN_ENCAP_FROM_NOMATCH) == 0 ||
626 			    (m->m_flags & M_VLANTAG) == 0)
627 				goto send_packet;
628 			/* Encapsulate tagged packet. */
629 			eth_vtag = m->m_pkthdr.ether_vtag;
630 			m->m_pkthdr.ether_vtag = 0;
631 			m->m_flags &= ~M_VLANTAG;
632 		}
633 
634 		/*
635 		 * Transform the Ethernet header into an Ethernet header
636 		 * with 802.1Q encapsulation.
637 		 * Mod of: ether_vlanencap.
638 		 *
639 		 * TPID = ether type encap
640 		 * Move DstMAC and SrcMAC from ETHER_TYPE.
641 		 * Before:
642 		 *  [free space ] [dmac] [smac] [ether_type] [payload]
643 		 *  <<<<<<<<<<<<< |-----------| |--------------------|
644 		 * After:
645 		 *  [dmac] [smac] [TPID] [PCP/CFI/VID] [ether_type] [payload]
646 		 *  |-----------| |-- inserted tag --| |--------------------|
647 		 */
648 		M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_NOWAIT);
649 		if (m == NULL)
650 			error = ENOMEM;
651 		else
652 			error = m_chk(&m, ETHER_VLAN_HDR_LEN);
653 		if (error != 0)
654 			goto mchk_err;
655 
656 		evl = mtod(m, struct ether_vlan_header *);
657 		bcopy(((char *)evl + ETHER_VLAN_ENCAP_LEN),
658 		    (char *)evl, (ETHER_ADDR_LEN * 2));
659 		evl->evl_encap_proto = priv->encap_proto;
660 		evl->evl_tag = htons(eth_vtag);
661 	}
662 
663 send_packet:
664 	NG_FWD_NEW_DATA(error, item, dst_hook, m);
665 	return (error);
666 net_down:
667 	error = ENETDOWN;
668 drop:
669 	m_freem(m);
670 mchk_err:
671 	NG_FREE_ITEM(item);
672 	return (error);
673 }
674 
675 static int
676 ng_vlan_shutdown(node_p node)
677 {
678 	const priv_p priv = NG_NODE_PRIVATE(node);
679 
680 	NG_NODE_SET_PRIVATE(node, NULL);
681 	NG_NODE_UNREF(node);
682 	free(priv, M_NETGRAPH);
683 	return (0);
684 }
685 
686 static int
687 ng_vlan_disconnect(hook_p hook)
688 {
689 	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
690 	uintptr_t hook_data;
691 
692 	if (hook == priv->downstream_hook)
693 		priv->downstream_hook = NULL;
694 	else if (hook == priv->nomatch_hook)
695 		priv->nomatch_hook = NULL;
696 	else {
697 		/* Purge a rule that refers to this hook. */
698 		hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
699 		if (IS_HOOK_VLAN_SET(hook_data))
700 			priv->vlan_hook[EVL_VLANOFTAG(hook_data)] = NULL;
701 	}
702 	NG_HOOK_SET_PRIVATE(hook, NULL);
703 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
704 	    (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
705 		ng_rmnode_self(NG_HOOK_NODE(hook));
706 	return (0);
707 }
708