xref: /openbmc/linux/net/8021q/vlan_dev.c (revision 22246614)
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: netdev@vger.kernel.org
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 static 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 		pr_debug("%s: unable to resolve type %X addresses.\n",
64 			 dev->name, ntohs(veth->h_vlan_encapsulated_proto));
65 
66 		memcpy(veth->h_source, dev->dev_addr, ETH_ALEN);
67 		break;
68 	}
69 
70 	return 0;
71 }
72 
73 static inline struct sk_buff *vlan_check_reorder_header(struct sk_buff *skb)
74 {
75 	if (vlan_dev_info(skb->dev)->flags & VLAN_FLAG_REORDER_HDR) {
76 		if (skb_shared(skb) || skb_cloned(skb)) {
77 			struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
78 			kfree_skb(skb);
79 			skb = nskb;
80 		}
81 		if (skb) {
82 			/* Lifted from Gleb's VLAN code... */
83 			memmove(skb->data - ETH_HLEN,
84 				skb->data - VLAN_ETH_HLEN, 12);
85 			skb->mac_header += VLAN_HLEN;
86 		}
87 	}
88 
89 	return skb;
90 }
91 
92 static inline void vlan_set_encap_proto(struct sk_buff *skb,
93 		struct vlan_hdr *vhdr)
94 {
95 	__be16 proto;
96 	unsigned char *rawp;
97 
98 	/*
99 	 * Was a VLAN packet, grab the encapsulated protocol, which the layer
100 	 * three protocols care about.
101 	 */
102 
103 	proto = vhdr->h_vlan_encapsulated_proto;
104 	if (ntohs(proto) >= 1536) {
105 		skb->protocol = proto;
106 		return;
107 	}
108 
109 	rawp = skb->data;
110 	if (*(unsigned short *)rawp == 0xFFFF)
111 		/*
112 		 * This is a magic hack to spot IPX packets. Older Novell
113 		 * breaks the protocol design and runs IPX over 802.3 without
114 		 * an 802.2 LLC layer. We look for FFFF which isn't a used
115 		 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
116 		 * but does for the rest.
117 		 */
118 		skb->protocol = htons(ETH_P_802_3);
119 	else
120 		/*
121 		 * Real 802.2 LLC
122 		 */
123 		skb->protocol = htons(ETH_P_802_2);
124 }
125 
126 /*
127  *	Determine the packet's protocol ID. The rule here is that we
128  *	assume 802.3 if the type field is short enough to be a length.
129  *	This is normal practice and works for any 'now in use' protocol.
130  *
131  *  Also, at this point we assume that we ARE dealing exclusively with
132  *  VLAN packets, or packets that should be made into VLAN packets based
133  *  on a default VLAN ID.
134  *
135  *  NOTE:  Should be similar to ethernet/eth.c.
136  *
137  *  SANITY NOTE:  This method is called when a packet is moving up the stack
138  *                towards userland.  To get here, it would have already passed
139  *                through the ethernet/eth.c eth_type_trans() method.
140  *  SANITY NOTE 2: We are referencing to the VLAN_HDR frields, which MAY be
141  *                 stored UNALIGNED in the memory.  RISC systems don't like
142  *                 such cases very much...
143  *  SANITY NOTE 2a: According to Dave Miller & Alexey, it will always be
144  *  		    aligned, so there doesn't need to be any of the unaligned
145  *  		    stuff.  It has been commented out now...  --Ben
146  *
147  */
148 int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
149 		  struct packet_type *ptype, struct net_device *orig_dev)
150 {
151 	struct vlan_hdr *vhdr;
152 	unsigned short vid;
153 	struct net_device_stats *stats;
154 	unsigned short vlan_TCI;
155 
156 	skb = skb_share_check(skb, GFP_ATOMIC);
157 	if (skb == NULL)
158 		goto err_free;
159 
160 	if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
161 		goto err_free;
162 
163 	vhdr = (struct vlan_hdr *)skb->data;
164 	vlan_TCI = ntohs(vhdr->h_vlan_TCI);
165 	vid = (vlan_TCI & VLAN_VID_MASK);
166 
167 	rcu_read_lock();
168 	skb->dev = __find_vlan_dev(dev, vid);
169 	if (!skb->dev) {
170 		pr_debug("%s: ERROR: No net_device for VID: %u on dev: %s\n",
171 			 __func__, (unsigned int)vid, dev->name);
172 		goto err_unlock;
173 	}
174 
175 	skb->dev->last_rx = jiffies;
176 
177 	stats = &skb->dev->stats;
178 	stats->rx_packets++;
179 	stats->rx_bytes += skb->len;
180 
181 	skb_pull_rcsum(skb, VLAN_HLEN);
182 
183 	skb->priority = vlan_get_ingress_priority(skb->dev,
184 						  ntohs(vhdr->h_vlan_TCI));
185 
186 	pr_debug("%s: priority: %u for TCI: %hu\n",
187 		 __func__, skb->priority, ntohs(vhdr->h_vlan_TCI));
188 
189 	switch (skb->pkt_type) {
190 	case PACKET_BROADCAST: /* Yeah, stats collect these together.. */
191 		/* stats->broadcast ++; // no such counter :-( */
192 		break;
193 
194 	case PACKET_MULTICAST:
195 		stats->multicast++;
196 		break;
197 
198 	case PACKET_OTHERHOST:
199 		/* Our lower layer thinks this is not local, let's make sure.
200 		 * This allows the VLAN to have a different MAC than the
201 		 * underlying device, and still route correctly.
202 		 */
203 		if (!compare_ether_addr(eth_hdr(skb)->h_dest,
204 					skb->dev->dev_addr))
205 			skb->pkt_type = PACKET_HOST;
206 		break;
207 	default:
208 		break;
209 	}
210 
211 	vlan_set_encap_proto(skb, vhdr);
212 
213 	skb = vlan_check_reorder_header(skb);
214 	if (!skb) {
215 		stats->rx_errors++;
216 		goto err_unlock;
217 	}
218 
219 	netif_rx(skb);
220 	rcu_read_unlock();
221 	return NET_RX_SUCCESS;
222 
223 err_unlock:
224 	rcu_read_unlock();
225 err_free:
226 	kfree_skb(skb);
227 	return NET_RX_DROP;
228 }
229 
230 static inline unsigned short
231 vlan_dev_get_egress_qos_mask(struct net_device *dev, struct sk_buff *skb)
232 {
233 	struct vlan_priority_tci_mapping *mp;
234 
235 	mp = vlan_dev_info(dev)->egress_priority_map[(skb->priority & 0xF)];
236 	while (mp) {
237 		if (mp->priority == skb->priority) {
238 			return mp->vlan_qos; /* This should already be shifted
239 					      * to mask correctly with the
240 					      * VLAN's TCI */
241 		}
242 		mp = mp->next;
243 	}
244 	return 0;
245 }
246 
247 /*
248  *	Create the VLAN header for an arbitrary protocol layer
249  *
250  *	saddr=NULL	means use device source address
251  *	daddr=NULL	means leave destination address (eg unresolved arp)
252  *
253  *  This is called when the SKB is moving down the stack towards the
254  *  physical devices.
255  */
256 static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
257 				unsigned short type,
258 				const void *daddr, const void *saddr,
259 				unsigned int len)
260 {
261 	struct vlan_hdr *vhdr;
262 	unsigned short veth_TCI = 0;
263 	int rc = 0;
264 	int build_vlan_header = 0;
265 	struct net_device *vdev = dev;
266 
267 	pr_debug("%s: skb: %p type: %hx len: %u vlan_id: %hx, daddr: %p\n",
268 		 __func__, skb, type, len, vlan_dev_info(dev)->vlan_id,
269 		 daddr);
270 
271 	/* build vlan header only if re_order_header flag is NOT set.  This
272 	 * fixes some programs that get confused when they see a VLAN device
273 	 * sending a frame that is VLAN encoded (the consensus is that the VLAN
274 	 * device should look completely like an Ethernet device when the
275 	 * REORDER_HEADER flag is set)	The drawback to this is some extra
276 	 * header shuffling in the hard_start_xmit.  Users can turn off this
277 	 * REORDER behaviour with the vconfig tool.
278 	 */
279 	if (!(vlan_dev_info(dev)->flags & VLAN_FLAG_REORDER_HDR))
280 		build_vlan_header = 1;
281 
282 	if (build_vlan_header) {
283 		vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);
284 
285 		/* build the four bytes that make this a VLAN header. */
286 
287 		/* Now, construct the second two bytes. This field looks
288 		 * something like:
289 		 * usr_priority: 3 bits	 (high bits)
290 		 * CFI		 1 bit
291 		 * VLAN ID	 12 bits (low bits)
292 		 *
293 		 */
294 		veth_TCI = vlan_dev_info(dev)->vlan_id;
295 		veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
296 
297 		vhdr->h_vlan_TCI = htons(veth_TCI);
298 
299 		/*
300 		 *  Set the protocol type. For a packet of type ETH_P_802_3 we
301 		 *  put the length in here instead. It is up to the 802.2
302 		 *  layer to carry protocol information.
303 		 */
304 
305 		if (type != ETH_P_802_3)
306 			vhdr->h_vlan_encapsulated_proto = htons(type);
307 		else
308 			vhdr->h_vlan_encapsulated_proto = htons(len);
309 
310 		skb->protocol = htons(ETH_P_8021Q);
311 		skb_reset_network_header(skb);
312 	}
313 
314 	/* Before delegating work to the lower layer, enter our MAC-address */
315 	if (saddr == NULL)
316 		saddr = dev->dev_addr;
317 
318 	dev = vlan_dev_info(dev)->real_dev;
319 
320 	/* MPLS can send us skbuffs w/out enough space.	This check will grow
321 	 * the skb if it doesn't have enough headroom. Not a beautiful solution,
322 	 * so I'll tick a counter so that users can know it's happening...
323 	 * If they care...
324 	 */
325 
326 	/* NOTE: This may still break if the underlying device is not the final
327 	 * device (and thus there are more headers to add...) It should work for
328 	 * good-ole-ethernet though.
329 	 */
330 	if (skb_headroom(skb) < dev->hard_header_len) {
331 		struct sk_buff *sk_tmp = skb;
332 		skb = skb_realloc_headroom(sk_tmp, dev->hard_header_len);
333 		kfree_skb(sk_tmp);
334 		if (skb == NULL) {
335 			struct net_device_stats *stats = &vdev->stats;
336 			stats->tx_dropped++;
337 			return -ENOMEM;
338 		}
339 		vlan_dev_info(vdev)->cnt_inc_headroom_on_tx++;
340 		pr_debug("%s: %s: had to grow skb\n", __func__, vdev->name);
341 	}
342 
343 	if (build_vlan_header) {
344 		/* Now make the underlying real hard header */
345 		rc = dev_hard_header(skb, dev, ETH_P_8021Q, daddr, saddr,
346 				     len + VLAN_HLEN);
347 		if (rc > 0)
348 			rc += VLAN_HLEN;
349 		else if (rc < 0)
350 			rc -= VLAN_HLEN;
351 	} else
352 		/* If here, then we'll just make a normal looking ethernet
353 		 * frame, but, the hard_start_xmit method will insert the tag
354 		 * (it has to be able to do this for bridged and other skbs
355 		 * that don't come down the protocol stack in an orderly manner.
356 		 */
357 		rc = dev_hard_header(skb, dev, type, daddr, saddr, len);
358 
359 	return rc;
360 }
361 
362 static int vlan_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
363 {
364 	struct net_device_stats *stats = &dev->stats;
365 	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
366 
367 	/* Handle non-VLAN frames if they are sent to us, for example by DHCP.
368 	 *
369 	 * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING
370 	 * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
371 	 */
372 
373 	if (veth->h_vlan_proto != htons(ETH_P_8021Q) ||
374 		vlan_dev_info(dev)->flags & VLAN_FLAG_REORDER_HDR) {
375 		int orig_headroom = skb_headroom(skb);
376 		unsigned short veth_TCI;
377 
378 		/* This is not a VLAN frame...but we can fix that! */
379 		vlan_dev_info(dev)->cnt_encap_on_xmit++;
380 
381 		pr_debug("%s: proto to encap: 0x%hx\n",
382 			 __func__, ntohs(veth->h_vlan_proto));
383 		/* Construct the second two bytes. This field looks something
384 		 * like:
385 		 * usr_priority: 3 bits	 (high bits)
386 		 * CFI		 1 bit
387 		 * VLAN ID	 12 bits (low bits)
388 		 */
389 		veth_TCI = vlan_dev_info(dev)->vlan_id;
390 		veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
391 
392 		skb = __vlan_put_tag(skb, veth_TCI);
393 		if (!skb) {
394 			stats->tx_dropped++;
395 			return 0;
396 		}
397 
398 		if (orig_headroom < VLAN_HLEN)
399 			vlan_dev_info(dev)->cnt_inc_headroom_on_tx++;
400 	}
401 
402 	pr_debug("%s: about to send skb: %p to dev: %s\n",
403 		__func__, skb, skb->dev->name);
404 	pr_debug("  " MAC_FMT " " MAC_FMT " %4hx %4hx %4hx\n",
405 		 veth->h_dest[0], veth->h_dest[1], veth->h_dest[2],
406 		 veth->h_dest[3], veth->h_dest[4], veth->h_dest[5],
407 		 veth->h_source[0], veth->h_source[1], veth->h_source[2],
408 		 veth->h_source[3], veth->h_source[4], veth->h_source[5],
409 		 veth->h_vlan_proto, veth->h_vlan_TCI,
410 		 veth->h_vlan_encapsulated_proto);
411 
412 	stats->tx_packets++; /* for statics only */
413 	stats->tx_bytes += skb->len;
414 
415 	skb->dev = vlan_dev_info(dev)->real_dev;
416 	dev_queue_xmit(skb);
417 
418 	return 0;
419 }
420 
421 static int vlan_dev_hwaccel_hard_start_xmit(struct sk_buff *skb,
422 					    struct net_device *dev)
423 {
424 	struct net_device_stats *stats = &dev->stats;
425 	unsigned short veth_TCI;
426 
427 	/* Construct the second two bytes. This field looks something
428 	 * like:
429 	 * usr_priority: 3 bits	 (high bits)
430 	 * CFI		 1 bit
431 	 * VLAN ID	 12 bits (low bits)
432 	 */
433 	veth_TCI = vlan_dev_info(dev)->vlan_id;
434 	veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
435 	skb = __vlan_hwaccel_put_tag(skb, veth_TCI);
436 
437 	stats->tx_packets++;
438 	stats->tx_bytes += skb->len;
439 
440 	skb->dev = vlan_dev_info(dev)->real_dev;
441 	dev_queue_xmit(skb);
442 
443 	return 0;
444 }
445 
446 static int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
447 {
448 	/* TODO: gotta make sure the underlying layer can handle it,
449 	 * maybe an IFF_VLAN_CAPABLE flag for devices?
450 	 */
451 	if (vlan_dev_info(dev)->real_dev->mtu < new_mtu)
452 		return -ERANGE;
453 
454 	dev->mtu = new_mtu;
455 
456 	return 0;
457 }
458 
459 void vlan_dev_set_ingress_priority(const struct net_device *dev,
460 				   u32 skb_prio, short vlan_prio)
461 {
462 	struct vlan_dev_info *vlan = vlan_dev_info(dev);
463 
464 	if (vlan->ingress_priority_map[vlan_prio & 0x7] && !skb_prio)
465 		vlan->nr_ingress_mappings--;
466 	else if (!vlan->ingress_priority_map[vlan_prio & 0x7] && skb_prio)
467 		vlan->nr_ingress_mappings++;
468 
469 	vlan->ingress_priority_map[vlan_prio & 0x7] = skb_prio;
470 }
471 
472 int vlan_dev_set_egress_priority(const struct net_device *dev,
473 				 u32 skb_prio, short vlan_prio)
474 {
475 	struct vlan_dev_info *vlan = vlan_dev_info(dev);
476 	struct vlan_priority_tci_mapping *mp = NULL;
477 	struct vlan_priority_tci_mapping *np;
478 	u32 vlan_qos = (vlan_prio << 13) & 0xE000;
479 
480 	/* See if a priority mapping exists.. */
481 	mp = vlan->egress_priority_map[skb_prio & 0xF];
482 	while (mp) {
483 		if (mp->priority == skb_prio) {
484 			if (mp->vlan_qos && !vlan_qos)
485 				vlan->nr_egress_mappings--;
486 			else if (!mp->vlan_qos && vlan_qos)
487 				vlan->nr_egress_mappings++;
488 			mp->vlan_qos = vlan_qos;
489 			return 0;
490 		}
491 		mp = mp->next;
492 	}
493 
494 	/* Create a new mapping then. */
495 	mp = vlan->egress_priority_map[skb_prio & 0xF];
496 	np = kmalloc(sizeof(struct vlan_priority_tci_mapping), GFP_KERNEL);
497 	if (!np)
498 		return -ENOBUFS;
499 
500 	np->next = mp;
501 	np->priority = skb_prio;
502 	np->vlan_qos = vlan_qos;
503 	vlan->egress_priority_map[skb_prio & 0xF] = np;
504 	if (vlan_qos)
505 		vlan->nr_egress_mappings++;
506 	return 0;
507 }
508 
509 /* Flags are defined in the vlan_flags enum in include/linux/if_vlan.h file. */
510 int vlan_dev_set_vlan_flag(const struct net_device *dev,
511 			   u32 flag, short flag_val)
512 {
513 	/* verify flag is supported */
514 	if (flag == VLAN_FLAG_REORDER_HDR) {
515 		if (flag_val)
516 			vlan_dev_info(dev)->flags |= VLAN_FLAG_REORDER_HDR;
517 		else
518 			vlan_dev_info(dev)->flags &= ~VLAN_FLAG_REORDER_HDR;
519 		return 0;
520 	}
521 	return -EINVAL;
522 }
523 
524 void vlan_dev_get_realdev_name(const struct net_device *dev, char *result)
525 {
526 	strncpy(result, vlan_dev_info(dev)->real_dev->name, 23);
527 }
528 
529 void vlan_dev_get_vid(const struct net_device *dev, unsigned short *result)
530 {
531 	*result = vlan_dev_info(dev)->vlan_id;
532 }
533 
534 static int vlan_dev_open(struct net_device *dev)
535 {
536 	struct vlan_dev_info *vlan = vlan_dev_info(dev);
537 	struct net_device *real_dev = vlan->real_dev;
538 	int err;
539 
540 	if (!(real_dev->flags & IFF_UP))
541 		return -ENETDOWN;
542 
543 	if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr)) {
544 		err = dev_unicast_add(real_dev, dev->dev_addr, ETH_ALEN);
545 		if (err < 0)
546 			return err;
547 	}
548 	memcpy(vlan->real_dev_addr, real_dev->dev_addr, ETH_ALEN);
549 
550 	if (dev->flags & IFF_ALLMULTI)
551 		dev_set_allmulti(real_dev, 1);
552 	if (dev->flags & IFF_PROMISC)
553 		dev_set_promiscuity(real_dev, 1);
554 
555 	return 0;
556 }
557 
558 static int vlan_dev_stop(struct net_device *dev)
559 {
560 	struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
561 
562 	dev_mc_unsync(real_dev, dev);
563 	dev_unicast_unsync(real_dev, dev);
564 	if (dev->flags & IFF_ALLMULTI)
565 		dev_set_allmulti(real_dev, -1);
566 	if (dev->flags & IFF_PROMISC)
567 		dev_set_promiscuity(real_dev, -1);
568 
569 	if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
570 		dev_unicast_delete(real_dev, dev->dev_addr, dev->addr_len);
571 
572 	return 0;
573 }
574 
575 static int vlan_dev_set_mac_address(struct net_device *dev, void *p)
576 {
577 	struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
578 	struct sockaddr *addr = p;
579 	int err;
580 
581 	if (!is_valid_ether_addr(addr->sa_data))
582 		return -EADDRNOTAVAIL;
583 
584 	if (!(dev->flags & IFF_UP))
585 		goto out;
586 
587 	if (compare_ether_addr(addr->sa_data, real_dev->dev_addr)) {
588 		err = dev_unicast_add(real_dev, addr->sa_data, ETH_ALEN);
589 		if (err < 0)
590 			return err;
591 	}
592 
593 	if (compare_ether_addr(dev->dev_addr, real_dev->dev_addr))
594 		dev_unicast_delete(real_dev, dev->dev_addr, ETH_ALEN);
595 
596 out:
597 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
598 	return 0;
599 }
600 
601 static int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
602 {
603 	struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
604 	struct ifreq ifrr;
605 	int err = -EOPNOTSUPP;
606 
607 	strncpy(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
608 	ifrr.ifr_ifru = ifr->ifr_ifru;
609 
610 	switch (cmd) {
611 	case SIOCGMIIPHY:
612 	case SIOCGMIIREG:
613 	case SIOCSMIIREG:
614 		if (real_dev->do_ioctl && netif_device_present(real_dev))
615 			err = real_dev->do_ioctl(real_dev, &ifrr, cmd);
616 		break;
617 	}
618 
619 	if (!err)
620 		ifr->ifr_ifru = ifrr.ifr_ifru;
621 
622 	return err;
623 }
624 
625 static void vlan_dev_change_rx_flags(struct net_device *dev, int change)
626 {
627 	struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
628 
629 	if (change & IFF_ALLMULTI)
630 		dev_set_allmulti(real_dev, dev->flags & IFF_ALLMULTI ? 1 : -1);
631 	if (change & IFF_PROMISC)
632 		dev_set_promiscuity(real_dev, dev->flags & IFF_PROMISC ? 1 : -1);
633 }
634 
635 static void vlan_dev_set_rx_mode(struct net_device *vlan_dev)
636 {
637 	dev_mc_sync(vlan_dev_info(vlan_dev)->real_dev, vlan_dev);
638 	dev_unicast_sync(vlan_dev_info(vlan_dev)->real_dev, vlan_dev);
639 }
640 
641 /*
642  * vlan network devices have devices nesting below it, and are a special
643  * "super class" of normal network devices; split their locks off into a
644  * separate class since they always nest.
645  */
646 static struct lock_class_key vlan_netdev_xmit_lock_key;
647 
648 static const struct header_ops vlan_header_ops = {
649 	.create	 = vlan_dev_hard_header,
650 	.rebuild = vlan_dev_rebuild_header,
651 	.parse	 = eth_header_parse,
652 };
653 
654 static int vlan_dev_init(struct net_device *dev)
655 {
656 	struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
657 	int subclass = 0;
658 
659 	/* IFF_BROADCAST|IFF_MULTICAST; ??? */
660 	dev->flags  = real_dev->flags & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI);
661 	dev->iflink = real_dev->ifindex;
662 	dev->state  = (real_dev->state & ((1<<__LINK_STATE_NOCARRIER) |
663 					  (1<<__LINK_STATE_DORMANT))) |
664 		      (1<<__LINK_STATE_PRESENT);
665 
666 	/* ipv6 shared card related stuff */
667 	dev->dev_id = real_dev->dev_id;
668 
669 	if (is_zero_ether_addr(dev->dev_addr))
670 		memcpy(dev->dev_addr, real_dev->dev_addr, dev->addr_len);
671 	if (is_zero_ether_addr(dev->broadcast))
672 		memcpy(dev->broadcast, real_dev->broadcast, dev->addr_len);
673 
674 	if (real_dev->features & NETIF_F_HW_VLAN_TX) {
675 		dev->header_ops      = real_dev->header_ops;
676 		dev->hard_header_len = real_dev->hard_header_len;
677 		dev->hard_start_xmit = vlan_dev_hwaccel_hard_start_xmit;
678 	} else {
679 		dev->header_ops      = &vlan_header_ops;
680 		dev->hard_header_len = real_dev->hard_header_len + VLAN_HLEN;
681 		dev->hard_start_xmit = vlan_dev_hard_start_xmit;
682 	}
683 
684 	if (real_dev->priv_flags & IFF_802_1Q_VLAN)
685 		subclass = 1;
686 
687 	lockdep_set_class_and_subclass(&dev->_xmit_lock,
688 				&vlan_netdev_xmit_lock_key, subclass);
689 	return 0;
690 }
691 
692 static void vlan_dev_uninit(struct net_device *dev)
693 {
694 	struct vlan_priority_tci_mapping *pm;
695 	struct vlan_dev_info *vlan = vlan_dev_info(dev);
696 	int i;
697 
698 	for (i = 0; i < ARRAY_SIZE(vlan->egress_priority_map); i++) {
699 		while ((pm = vlan->egress_priority_map[i]) != NULL) {
700 			vlan->egress_priority_map[i] = pm->next;
701 			kfree(pm);
702 		}
703 	}
704 }
705 
706 void vlan_setup(struct net_device *dev)
707 {
708 	ether_setup(dev);
709 
710 	dev->priv_flags		|= IFF_802_1Q_VLAN;
711 	dev->tx_queue_len	= 0;
712 
713 	dev->change_mtu		= vlan_dev_change_mtu;
714 	dev->init		= vlan_dev_init;
715 	dev->uninit		= vlan_dev_uninit;
716 	dev->open		= vlan_dev_open;
717 	dev->stop		= vlan_dev_stop;
718 	dev->set_mac_address	= vlan_dev_set_mac_address;
719 	dev->set_rx_mode	= vlan_dev_set_rx_mode;
720 	dev->set_multicast_list	= vlan_dev_set_rx_mode;
721 	dev->change_rx_flags	= vlan_dev_change_rx_flags;
722 	dev->do_ioctl		= vlan_dev_ioctl;
723 	dev->destructor		= free_netdev;
724 
725 	memset(dev->broadcast, 0, ETH_ALEN);
726 }
727