xref: /linux/net/8021q/vlan_dev.c (revision 8b4a40809e5330c9da5d20107d693d92d73b31dc)
1 /* -*- linux-c -*-
2  * INET		802.1Q VLAN
3  *		Ethernet-type device handling.
4  *
5  * Authors:	Ben Greear <greearb@candelatech.com>
6  *              Please send support related email to: vlan@scry.wanfear.com
7  *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
8  *
9  * Fixes:       Mar 22 2001: Martin Bokaemper <mbokaemper@unispherenetworks.com>
10  *                - reset skb->pkt_type on incoming packets when MAC was changed
11  *                - see that changed MAC is saddr for outgoing packets
12  *              Oct 20, 2001:  Ard van Breeman:
13  *                - Fix MC-list, finally.
14  *                - Flush MC-list on VLAN destroy.
15  *
16  *
17  *		This program is free software; you can redistribute it and/or
18  *		modify it under the terms of the GNU General Public License
19  *		as published by the Free Software Foundation; either version
20  *		2 of the License, or (at your option) any later version.
21  */
22 
23 #include <linux/module.h>
24 #include <linux/mm.h>
25 #include <linux/in.h>
26 #include <linux/init.h>
27 #include <asm/uaccess.h> /* for copy_from_user */
28 #include <linux/skbuff.h>
29 #include <linux/netdevice.h>
30 #include <linux/etherdevice.h>
31 #include <net/datalink.h>
32 #include <net/p8022.h>
33 #include <net/arp.h>
34 
35 #include "vlan.h"
36 #include "vlanproc.h"
37 #include <linux/if_vlan.h>
38 #include <net/ip.h>
39 
40 /*
41  *	Rebuild the Ethernet MAC header. This is called after an ARP
42  *	(or in future other address resolution) has completed on this
43  *	sk_buff. We now let ARP fill in the other fields.
44  *
45  *	This routine CANNOT use cached dst->neigh!
46  *	Really, it is used only when dst->neigh is wrong.
47  *
48  * TODO:  This needs a checkup, I'm ignorant here. --BLG
49  */
50 int vlan_dev_rebuild_header(struct sk_buff *skb)
51 {
52 	struct net_device *dev = skb->dev;
53 	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
54 
55 	switch (veth->h_vlan_encapsulated_proto) {
56 #ifdef CONFIG_INET
57 	case __constant_htons(ETH_P_IP):
58 
59 		/* TODO:  Confirm this will work with VLAN headers... */
60 		return arp_find(veth->h_dest, skb);
61 #endif
62 	default:
63 		printk(VLAN_DBG
64 		       "%s: unable to resolve type %X addresses.\n",
65 		       dev->name, ntohs(veth->h_vlan_encapsulated_proto));
66 
67 		memcpy(veth->h_source, dev->dev_addr, ETH_ALEN);
68 		break;
69 	}
70 
71 	return 0;
72 }
73 
74 static inline struct sk_buff *vlan_check_reorder_header(struct sk_buff *skb)
75 {
76 	if (VLAN_DEV_INFO(skb->dev)->flags & VLAN_FLAG_REORDER_HDR) {
77 		if (skb_shared(skb) || skb_cloned(skb)) {
78 			struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
79 			kfree_skb(skb);
80 			skb = nskb;
81 		}
82 		if (skb) {
83 			/* Lifted from Gleb's VLAN code... */
84 			memmove(skb->data - ETH_HLEN,
85 				skb->data - VLAN_ETH_HLEN, 12);
86 			skb->mac_header += VLAN_HLEN;
87 		}
88 	}
89 
90 	return skb;
91 }
92 
93 /*
94  *	Determine the packet's protocol ID. The rule here is that we
95  *	assume 802.3 if the type field is short enough to be a length.
96  *	This is normal practice and works for any 'now in use' protocol.
97  *
98  *  Also, at this point we assume that we ARE dealing exclusively with
99  *  VLAN packets, or packets that should be made into VLAN packets based
100  *  on a default VLAN ID.
101  *
102  *  NOTE:  Should be similar to ethernet/eth.c.
103  *
104  *  SANITY NOTE:  This method is called when a packet is moving up the stack
105  *                towards userland.  To get here, it would have already passed
106  *                through the ethernet/eth.c eth_type_trans() method.
107  *  SANITY NOTE 2: We are referencing to the VLAN_HDR frields, which MAY be
108  *                 stored UNALIGNED in the memory.  RISC systems don't like
109  *                 such cases very much...
110  *  SANITY NOTE 2a:  According to Dave Miller & Alexey, it will always be aligned,
111  *                 so there doesn't need to be any of the unaligned stuff.  It has
112  *                 been commented out now...  --Ben
113  *
114  */
115 int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
116 		  struct packet_type* ptype, struct net_device *orig_dev)
117 {
118 	unsigned char *rawp = NULL;
119 	struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data);
120 	unsigned short vid;
121 	struct net_device_stats *stats;
122 	unsigned short vlan_TCI;
123 	__be16 proto;
124 
125 	/* vlan_TCI = ntohs(get_unaligned(&vhdr->h_vlan_TCI)); */
126 	vlan_TCI = ntohs(vhdr->h_vlan_TCI);
127 
128 	vid = (vlan_TCI & VLAN_VID_MASK);
129 
130 #ifdef VLAN_DEBUG
131 	printk(VLAN_DBG "%s: skb: %p vlan_id: %hx\n",
132 		__FUNCTION__, skb, vid);
133 #endif
134 
135 	/* Ok, we will find the correct VLAN device, strip the header,
136 	 * and then go on as usual.
137 	 */
138 
139 	/* We have 12 bits of vlan ID.
140 	 *
141 	 * We must not drop allow preempt until we hold a
142 	 * reference to the device (netif_rx does that) or we
143 	 * fail.
144 	 */
145 
146 	rcu_read_lock();
147 	skb->dev = __find_vlan_dev(dev, vid);
148 	if (!skb->dev) {
149 		rcu_read_unlock();
150 
151 #ifdef VLAN_DEBUG
152 		printk(VLAN_DBG "%s: ERROR: No net_device for VID: %i on dev: %s [%i]\n",
153 			__FUNCTION__, (unsigned int)(vid), dev->name, dev->ifindex);
154 #endif
155 		kfree_skb(skb);
156 		return -1;
157 	}
158 
159 	skb->dev->last_rx = jiffies;
160 
161 	/* Bump the rx counters for the VLAN device. */
162 	stats = vlan_dev_get_stats(skb->dev);
163 	stats->rx_packets++;
164 	stats->rx_bytes += skb->len;
165 
166 	/* Take off the VLAN header (4 bytes currently) */
167 	skb_pull_rcsum(skb, VLAN_HLEN);
168 
169 	/* Ok, lets check to make sure the device (dev) we
170 	 * came in on is what this VLAN is attached to.
171 	 */
172 
173 	if (dev != VLAN_DEV_INFO(skb->dev)->real_dev) {
174 		rcu_read_unlock();
175 
176 #ifdef VLAN_DEBUG
177 		printk(VLAN_DBG "%s: dropping skb: %p because came in on wrong device, dev: %s  real_dev: %s, skb_dev: %s\n",
178 			__FUNCTION__, skb, dev->name,
179 			VLAN_DEV_INFO(skb->dev)->real_dev->name,
180 			skb->dev->name);
181 #endif
182 		kfree_skb(skb);
183 		stats->rx_errors++;
184 		return -1;
185 	}
186 
187 	/*
188 	 * Deal with ingress priority mapping.
189 	 */
190 	skb->priority = vlan_get_ingress_priority(skb->dev, ntohs(vhdr->h_vlan_TCI));
191 
192 #ifdef VLAN_DEBUG
193 	printk(VLAN_DBG "%s: priority: %lu  for TCI: %hu (hbo)\n",
194 		__FUNCTION__, (unsigned long)(skb->priority),
195 		ntohs(vhdr->h_vlan_TCI));
196 #endif
197 
198 	/* The ethernet driver already did the pkt_type calculations
199 	 * for us...
200 	 */
201 	switch (skb->pkt_type) {
202 	case PACKET_BROADCAST: /* Yeah, stats collect these together.. */
203 		// stats->broadcast ++; // no such counter :-(
204 		break;
205 
206 	case PACKET_MULTICAST:
207 		stats->multicast++;
208 		break;
209 
210 	case PACKET_OTHERHOST:
211 		/* Our lower layer thinks this is not local, let's make sure.
212 		 * This allows the VLAN to have a different MAC than the underlying
213 		 * device, and still route correctly.
214 		 */
215 		if (!compare_ether_addr(eth_hdr(skb)->h_dest, skb->dev->dev_addr)) {
216 			/* It is for our (changed) MAC-address! */
217 			skb->pkt_type = PACKET_HOST;
218 		}
219 		break;
220 	default:
221 		break;
222 	}
223 
224 	/*  Was a VLAN packet, grab the encapsulated protocol, which the layer
225 	 * three protocols care about.
226 	 */
227 	/* proto = get_unaligned(&vhdr->h_vlan_encapsulated_proto); */
228 	proto = vhdr->h_vlan_encapsulated_proto;
229 
230 	skb->protocol = proto;
231 	if (ntohs(proto) >= 1536) {
232 		/* place it back on the queue to be handled by
233 		 * true layer 3 protocols.
234 		 */
235 
236 		/* See if we are configured to re-write the VLAN header
237 		 * to make it look like ethernet...
238 		 */
239 		skb = vlan_check_reorder_header(skb);
240 
241 		/* Can be null if skb-clone fails when re-ordering */
242 		if (skb) {
243 			netif_rx(skb);
244 		} else {
245 			/* TODO:  Add a more specific counter here. */
246 			stats->rx_errors++;
247 		}
248 		rcu_read_unlock();
249 		return 0;
250 	}
251 
252 	rawp = skb->data;
253 
254 	/*
255 	 * This is a magic hack to spot IPX packets. Older Novell breaks
256 	 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
257 	 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
258 	 * won't work for fault tolerant netware but does for the rest.
259 	 */
260 	if (*(unsigned short *)rawp == 0xFFFF) {
261 		skb->protocol = htons(ETH_P_802_3);
262 		/* place it back on the queue to be handled by true layer 3 protocols.
263 		 */
264 
265 		/* See if we are configured to re-write the VLAN header
266 		 * to make it look like ethernet...
267 		 */
268 		skb = vlan_check_reorder_header(skb);
269 
270 		/* Can be null if skb-clone fails when re-ordering */
271 		if (skb) {
272 			netif_rx(skb);
273 		} else {
274 			/* TODO:  Add a more specific counter here. */
275 			stats->rx_errors++;
276 		}
277 		rcu_read_unlock();
278 		return 0;
279 	}
280 
281 	/*
282 	 *	Real 802.2 LLC
283 	 */
284 	skb->protocol = htons(ETH_P_802_2);
285 	/* place it back on the queue to be handled by upper layer protocols.
286 	 */
287 
288 	/* See if we are configured to re-write the VLAN header
289 	 * to make it look like ethernet...
290 	 */
291 	skb = vlan_check_reorder_header(skb);
292 
293 	/* Can be null if skb-clone fails when re-ordering */
294 	if (skb) {
295 		netif_rx(skb);
296 	} else {
297 		/* TODO:  Add a more specific counter here. */
298 		stats->rx_errors++;
299 	}
300 	rcu_read_unlock();
301 	return 0;
302 }
303 
304 static inline unsigned short vlan_dev_get_egress_qos_mask(struct net_device* dev,
305 							  struct sk_buff* skb)
306 {
307 	struct vlan_priority_tci_mapping *mp =
308 		VLAN_DEV_INFO(dev)->egress_priority_map[(skb->priority & 0xF)];
309 
310 	while (mp) {
311 		if (mp->priority == skb->priority) {
312 			return mp->vlan_qos; /* This should already be shifted to mask
313 					      * correctly with the VLAN's TCI
314 					      */
315 		}
316 		mp = mp->next;
317 	}
318 	return 0;
319 }
320 
321 /*
322  *	Create the VLAN header for an arbitrary protocol layer
323  *
324  *	saddr=NULL	means use device source address
325  *	daddr=NULL	means leave destination address (eg unresolved arp)
326  *
327  *  This is called when the SKB is moving down the stack towards the
328  *  physical devices.
329  */
330 int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
331 			 unsigned short type, void *daddr, void *saddr,
332 			 unsigned len)
333 {
334 	struct vlan_hdr *vhdr;
335 	unsigned short veth_TCI = 0;
336 	int rc = 0;
337 	int build_vlan_header = 0;
338 	struct net_device *vdev = dev; /* save this for the bottom of the method */
339 
340 #ifdef VLAN_DEBUG
341 	printk(VLAN_DBG "%s: skb: %p type: %hx len: %x vlan_id: %hx, daddr: %p\n",
342 		__FUNCTION__, skb, type, len, VLAN_DEV_INFO(dev)->vlan_id, daddr);
343 #endif
344 
345 	/* build vlan header only if re_order_header flag is NOT set.  This
346 	 * fixes some programs that get confused when they see a VLAN device
347 	 * sending a frame that is VLAN encoded (the consensus is that the VLAN
348 	 * device should look completely like an Ethernet device when the
349 	 * REORDER_HEADER flag is set)	The drawback to this is some extra
350 	 * header shuffling in the hard_start_xmit.  Users can turn off this
351 	 * REORDER behaviour with the vconfig tool.
352 	 */
353 	if (!(VLAN_DEV_INFO(dev)->flags & VLAN_FLAG_REORDER_HDR))
354 		build_vlan_header = 1;
355 
356 	if (build_vlan_header) {
357 		vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);
358 
359 		/* build the four bytes that make this a VLAN header. */
360 
361 		/* Now, construct the second two bytes. This field looks something
362 		 * like:
363 		 * usr_priority: 3 bits	 (high bits)
364 		 * CFI		 1 bit
365 		 * VLAN ID	 12 bits (low bits)
366 		 *
367 		 */
368 		veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
369 		veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
370 
371 		vhdr->h_vlan_TCI = htons(veth_TCI);
372 
373 		/*
374 		 *  Set the protocol type.
375 		 *  For a packet of type ETH_P_802_3 we put the length in here instead.
376 		 *  It is up to the 802.2 layer to carry protocol information.
377 		 */
378 
379 		if (type != ETH_P_802_3) {
380 			vhdr->h_vlan_encapsulated_proto = htons(type);
381 		} else {
382 			vhdr->h_vlan_encapsulated_proto = htons(len);
383 		}
384 
385 		skb->protocol = htons(ETH_P_8021Q);
386 		skb_reset_network_header(skb);
387 	}
388 
389 	/* Before delegating work to the lower layer, enter our MAC-address */
390 	if (saddr == NULL)
391 		saddr = dev->dev_addr;
392 
393 	dev = VLAN_DEV_INFO(dev)->real_dev;
394 
395 	/* MPLS can send us skbuffs w/out enough space.	 This check will grow the
396 	 * skb if it doesn't have enough headroom.  Not a beautiful solution, so
397 	 * I'll tick a counter so that users can know it's happening...	 If they
398 	 * care...
399 	 */
400 
401 	/* NOTE:  This may still break if the underlying device is not the final
402 	 * device (and thus there are more headers to add...)  It should work for
403 	 * good-ole-ethernet though.
404 	 */
405 	if (skb_headroom(skb) < dev->hard_header_len) {
406 		struct sk_buff *sk_tmp = skb;
407 		skb = skb_realloc_headroom(sk_tmp, dev->hard_header_len);
408 		kfree_skb(sk_tmp);
409 		if (skb == NULL) {
410 			struct net_device_stats *stats = vlan_dev_get_stats(vdev);
411 			stats->tx_dropped++;
412 			return -ENOMEM;
413 		}
414 		VLAN_DEV_INFO(vdev)->cnt_inc_headroom_on_tx++;
415 #ifdef VLAN_DEBUG
416 		printk(VLAN_DBG "%s: %s: had to grow skb.\n", __FUNCTION__, vdev->name);
417 #endif
418 	}
419 
420 	if (build_vlan_header) {
421 		/* Now make the underlying real hard header */
422 		rc = dev->hard_header(skb, dev, ETH_P_8021Q, daddr, saddr, len + VLAN_HLEN);
423 
424 		if (rc > 0) {
425 			rc += VLAN_HLEN;
426 		} else if (rc < 0) {
427 			rc -= VLAN_HLEN;
428 		}
429 	} else {
430 		/* If here, then we'll just make a normal looking ethernet frame,
431 		 * but, the hard_start_xmit method will insert the tag (it has to
432 		 * be able to do this for bridged and other skbs that don't come
433 		 * down the protocol stack in an orderly manner.
434 		 */
435 		rc = dev->hard_header(skb, dev, type, daddr, saddr, len);
436 	}
437 
438 	return rc;
439 }
440 
441 int vlan_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
442 {
443 	struct net_device_stats *stats = vlan_dev_get_stats(dev);
444 	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
445 
446 	/* Handle non-VLAN frames if they are sent to us, for example by DHCP.
447 	 *
448 	 * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING
449 	 * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
450 	 */
451 
452 	if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
453 		int orig_headroom = skb_headroom(skb);
454 		unsigned short veth_TCI;
455 
456 		/* This is not a VLAN frame...but we can fix that! */
457 		VLAN_DEV_INFO(dev)->cnt_encap_on_xmit++;
458 
459 #ifdef VLAN_DEBUG
460 		printk(VLAN_DBG "%s: proto to encap: 0x%hx (hbo)\n",
461 			__FUNCTION__, htons(veth->h_vlan_proto));
462 #endif
463 		/* Construct the second two bytes. This field looks something
464 		 * like:
465 		 * usr_priority: 3 bits	 (high bits)
466 		 * CFI		 1 bit
467 		 * VLAN ID	 12 bits (low bits)
468 		 */
469 		veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
470 		veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
471 
472 		skb = __vlan_put_tag(skb, veth_TCI);
473 		if (!skb) {
474 			stats->tx_dropped++;
475 			return 0;
476 		}
477 
478 		if (orig_headroom < VLAN_HLEN) {
479 			VLAN_DEV_INFO(dev)->cnt_inc_headroom_on_tx++;
480 		}
481 	}
482 
483 #ifdef VLAN_DEBUG
484 	printk(VLAN_DBG "%s: about to send skb: %p to dev: %s\n",
485 		__FUNCTION__, skb, skb->dev->name);
486 	printk(VLAN_DBG "  %2hx.%2hx.%2hx.%2xh.%2hx.%2hx %2hx.%2hx.%2hx.%2hx.%2hx.%2hx %4hx %4hx %4hx\n",
487 	       veth->h_dest[0], veth->h_dest[1], veth->h_dest[2], veth->h_dest[3], veth->h_dest[4], veth->h_dest[5],
488 	       veth->h_source[0], veth->h_source[1], veth->h_source[2], veth->h_source[3], veth->h_source[4], veth->h_source[5],
489 	       veth->h_vlan_proto, veth->h_vlan_TCI, veth->h_vlan_encapsulated_proto);
490 #endif
491 
492 	stats->tx_packets++; /* for statics only */
493 	stats->tx_bytes += skb->len;
494 
495 	skb->dev = VLAN_DEV_INFO(dev)->real_dev;
496 	dev_queue_xmit(skb);
497 
498 	return 0;
499 }
500 
501 int vlan_dev_hwaccel_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
502 {
503 	struct net_device_stats *stats = vlan_dev_get_stats(dev);
504 	unsigned short veth_TCI;
505 
506 	/* Construct the second two bytes. This field looks something
507 	 * like:
508 	 * usr_priority: 3 bits	 (high bits)
509 	 * CFI		 1 bit
510 	 * VLAN ID	 12 bits (low bits)
511 	 */
512 	veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
513 	veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
514 	skb = __vlan_hwaccel_put_tag(skb, veth_TCI);
515 
516 	stats->tx_packets++;
517 	stats->tx_bytes += skb->len;
518 
519 	skb->dev = VLAN_DEV_INFO(dev)->real_dev;
520 	dev_queue_xmit(skb);
521 
522 	return 0;
523 }
524 
525 int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
526 {
527 	/* TODO: gotta make sure the underlying layer can handle it,
528 	 * maybe an IFF_VLAN_CAPABLE flag for devices?
529 	 */
530 	if (VLAN_DEV_INFO(dev)->real_dev->mtu < new_mtu)
531 		return -ERANGE;
532 
533 	dev->mtu = new_mtu;
534 
535 	return 0;
536 }
537 
538 void vlan_dev_set_ingress_priority(const struct net_device *dev,
539 				   u32 skb_prio, short vlan_prio)
540 {
541 	struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
542 
543 	if (vlan->ingress_priority_map[vlan_prio & 0x7] && !skb_prio)
544 		vlan->nr_ingress_mappings--;
545 	else if (!vlan->ingress_priority_map[vlan_prio & 0x7] && skb_prio)
546 		vlan->nr_ingress_mappings++;
547 
548 	vlan->ingress_priority_map[vlan_prio & 0x7] = skb_prio;
549 }
550 
551 int vlan_dev_set_egress_priority(const struct net_device *dev,
552 				 u32 skb_prio, short vlan_prio)
553 {
554 	struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
555 	struct vlan_priority_tci_mapping *mp = NULL;
556 	struct vlan_priority_tci_mapping *np;
557 	u32 vlan_qos = (vlan_prio << 13) & 0xE000;
558 
559 	/* See if a priority mapping exists.. */
560 	mp = vlan->egress_priority_map[skb_prio & 0xF];
561 	while (mp) {
562 		if (mp->priority == skb_prio) {
563 			if (mp->vlan_qos && !vlan_qos)
564 				vlan->nr_egress_mappings--;
565 			else if (!mp->vlan_qos && vlan_qos)
566 				vlan->nr_egress_mappings++;
567 			mp->vlan_qos = vlan_qos;
568 			return 0;
569 		}
570 		mp = mp->next;
571 	}
572 
573 	/* Create a new mapping then. */
574 	mp = vlan->egress_priority_map[skb_prio & 0xF];
575 	np = kmalloc(sizeof(struct vlan_priority_tci_mapping), GFP_KERNEL);
576 	if (!np)
577 		return -ENOBUFS;
578 
579 	np->next = mp;
580 	np->priority = skb_prio;
581 	np->vlan_qos = vlan_qos;
582 	vlan->egress_priority_map[skb_prio & 0xF] = np;
583 	if (vlan_qos)
584 		vlan->nr_egress_mappings++;
585 	return 0;
586 }
587 
588 /* Flags are defined in the vlan_flags enum in include/linux/if_vlan.h file. */
589 int vlan_dev_set_vlan_flag(const struct net_device *dev,
590 			   u32 flag, short flag_val)
591 {
592 	/* verify flag is supported */
593 	if (flag == VLAN_FLAG_REORDER_HDR) {
594 		if (flag_val) {
595 			VLAN_DEV_INFO(dev)->flags |= VLAN_FLAG_REORDER_HDR;
596 		} else {
597 			VLAN_DEV_INFO(dev)->flags &= ~VLAN_FLAG_REORDER_HDR;
598 		}
599 		return 0;
600 	}
601 	printk(KERN_ERR "%s: flag %i is not valid.\n", __FUNCTION__, flag);
602 	return -EINVAL;
603 }
604 
605 void vlan_dev_get_realdev_name(const struct net_device *dev, char *result)
606 {
607 	strncpy(result, VLAN_DEV_INFO(dev)->real_dev->name, 23);
608 }
609 
610 void vlan_dev_get_vid(const struct net_device *dev, unsigned short *result)
611 {
612 	*result = VLAN_DEV_INFO(dev)->vlan_id;
613 }
614 
615 int vlan_dev_open(struct net_device *dev)
616 {
617 	struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
618 	struct net_device *real_dev = vlan->real_dev;
619 	int err;
620 
621 	if (!(real_dev->flags & IFF_UP))
622 		return -ENETDOWN;
623 
624 	if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr)) {
625 		err = dev_unicast_add(real_dev, dev->dev_addr, ETH_ALEN);
626 		if (err < 0)
627 			return err;
628 	}
629 	memcpy(vlan->real_dev_addr, real_dev->dev_addr, ETH_ALEN);
630 
631 	if (dev->flags & IFF_ALLMULTI)
632 		dev_set_allmulti(real_dev, 1);
633 	if (dev->flags & IFF_PROMISC)
634 		dev_set_promiscuity(real_dev, 1);
635 
636 	return 0;
637 }
638 
639 int vlan_dev_stop(struct net_device *dev)
640 {
641 	struct net_device *real_dev = VLAN_DEV_INFO(dev)->real_dev;
642 
643 	dev_mc_unsync(real_dev, dev);
644 	if (dev->flags & IFF_ALLMULTI)
645 		dev_set_allmulti(real_dev, -1);
646 	if (dev->flags & IFF_PROMISC)
647 		dev_set_promiscuity(real_dev, -1);
648 
649 	if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
650 		dev_unicast_delete(real_dev, dev->dev_addr, dev->addr_len);
651 
652 	return 0;
653 }
654 
655 int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
656 {
657 	struct net_device *real_dev = VLAN_DEV_INFO(dev)->real_dev;
658 	struct ifreq ifrr;
659 	int err = -EOPNOTSUPP;
660 
661 	strncpy(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
662 	ifrr.ifr_ifru = ifr->ifr_ifru;
663 
664 	switch(cmd) {
665 	case SIOCGMIIPHY:
666 	case SIOCGMIIREG:
667 	case SIOCSMIIREG:
668 		if (real_dev->do_ioctl && netif_device_present(real_dev))
669 			err = real_dev->do_ioctl(real_dev, &ifrr, cmd);
670 		break;
671 
672 	case SIOCETHTOOL:
673 		err = dev_ethtool(&ifrr);
674 	}
675 
676 	if (!err)
677 		ifr->ifr_ifru = ifrr.ifr_ifru;
678 
679 	return err;
680 }
681 
682 void vlan_change_rx_flags(struct net_device *dev, int change)
683 {
684 	struct net_device *real_dev = VLAN_DEV_INFO(dev)->real_dev;
685 
686 	if (change & IFF_ALLMULTI)
687 		dev_set_allmulti(real_dev, dev->flags & IFF_ALLMULTI ? 1 : -1);
688 	if (change & IFF_PROMISC)
689 		dev_set_promiscuity(real_dev, dev->flags & IFF_PROMISC ? 1 : -1);
690 }
691 
692 /** Taken from Gleb + Lennert's VLAN code, and modified... */
693 void vlan_dev_set_multicast_list(struct net_device *vlan_dev)
694 {
695 	dev_mc_sync(VLAN_DEV_INFO(vlan_dev)->real_dev, vlan_dev);
696 }
697