summaryrefslogtreecommitdiffstats
path: root/net/8021q/vlan_dev.c
blob: f2a8750bbf1d7555633c1b2562883dcd02b800bc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
/* -*- linux-c -*-
 * INET		802.1Q VLAN
 *		Ethernet-type device handling.
 *
 * Authors:	Ben Greear <greearb@candelatech.com>
 *              Please send support related email to: vlan@scry.wanfear.com
 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
 * 
 * Fixes:       Mar 22 2001: Martin Bokaemper <mbokaemper@unispherenetworks.com>
 *                - reset skb->pkt_type on incoming packets when MAC was changed
 *                - see that changed MAC is saddr for outgoing packets
 *              Oct 20, 2001:  Ard van Breeman:
 *                - Fix MC-list, finally.
 *                - Flush MC-list on VLAN destroy.
 *                
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/in.h>
#include <linux/init.h>
#include <asm/uaccess.h> /* for copy_from_user */
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <net/datalink.h>
#include <net/p8022.h>
#include <net/arp.h>

#include "vlan.h"
#include "vlanproc.h"
#include <linux/if_vlan.h>
#include <net/ip.h>

/*
 *	Rebuild the Ethernet MAC header. This is called after an ARP
 *	(or in future other address resolution) has completed on this
 *	sk_buff. We now let ARP fill in the other fields.
 *
 *	This routine CANNOT use cached dst->neigh!
 *	Really, it is used only when dst->neigh is wrong.
 *
 * TODO:  This needs a checkup, I'm ignorant here. --BLG
 */
int vlan_dev_rebuild_header(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);

	switch (veth->h_vlan_encapsulated_proto) {
#ifdef CONFIG_INET
	case __constant_htons(ETH_P_IP):

		/* TODO:  Confirm this will work with VLAN headers... */
		return arp_find(veth->h_dest, skb);
#endif	
	default:
		printk(VLAN_DBG
		       "%s: unable to resolve type %X addresses.\n", 
		       dev->name, (int)veth->h_vlan_encapsulated_proto);
	 
		memcpy(veth->h_source, dev->dev_addr, ETH_ALEN);
		break;
	};

	return 0;
}

static inline struct sk_buff *vlan_check_reorder_header(struct sk_buff *skb)
{
	if (VLAN_DEV_INFO(skb->dev)->flags & 1) {
		if (skb_shared(skb) || skb_cloned(skb)) {
			struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
			kfree_skb(skb);
			skb = nskb;
		}
		if (skb) {
			/* Lifted from Gleb's VLAN code... */
			memmove(skb->data - ETH_HLEN,
				skb->data - VLAN_ETH_HLEN, 12);
			skb->mac.raw += VLAN_HLEN;
		}
	}

	return skb;
}

/*
 *	Determine the packet's protocol ID. The rule here is that we 
 *	assume 802.3 if the type field is short enough to be a length.
 *	This is normal practice and works for any 'now in use' protocol.
 *
 *  Also, at this point we assume that we ARE dealing exclusively with
 *  VLAN packets, or packets that should be made into VLAN packets based
 *  on a default VLAN ID.
 *
 *  NOTE:  Should be similar to ethernet/eth.c.
 *
 *  SANITY NOTE:  This method is called when a packet is moving up the stack
 *                towards userland.  To get here, it would have already passed
 *                through the ethernet/eth.c eth_type_trans() method.
 *  SANITY NOTE 2: We are referencing to the VLAN_HDR frields, which MAY be
 *                 stored UNALIGNED in the memory.  RISC systems don't like
 *                 such cases very much...
 *  SANITY NOTE 2a:  According to Dave Miller & Alexey, it will always be aligned,
 *                 so there doesn't need to be any of the unaligned stuff.  It has
 *                 been commented out now...  --Ben
 *
 */
int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
                  struct packet_type* ptype, struct net_device *orig_dev)
{
	unsigned char *rawp = NULL;
	struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data);
	unsigned short vid;
	struct net_device_stats *stats;
	unsigned short vlan_TCI;
	__be16 proto;

	/* vlan_TCI = ntohs(get_unaligned(&vhdr->h_vlan_TCI)); */
	vlan_TCI = ntohs(vhdr->h_vlan_TCI);

	vid = (vlan_TCI & VLAN_VID_MASK);

#ifdef VLAN_DEBUG
	printk(VLAN_DBG "%s: skb: %p vlan_id: %hx\n",
		__FUNCTION__, skb, vid);
#endif

	/* Ok, we will find the correct VLAN device, strip the header,
	 * and then go on as usual.
	 */

	/* We have 12 bits of vlan ID.
	 *
	 * We must not drop allow preempt until we hold a
	 * reference to the device (netif_rx does that) or we
	 * fail.
	 */

	rcu_read_lock();
	skb->dev = __find_vlan_dev(dev, vid);
	if (!skb->dev) {
		rcu_read_unlock();

#ifdef VLAN_DEBUG
		printk(VLAN_DBG "%s: ERROR: No net_device for VID: %i on dev: %s [%i]\n",
			__FUNCTION__, (unsigned int)(vid), dev->name, dev->ifindex);
#endif
		kfree_skb(skb);
		return -1;
	}

	skb->dev->last_rx = jiffies;

	/* Bump the rx counters for the VLAN device. */
	stats = vlan_dev_get_stats(skb->dev);
	stats->rx_packets++;
	stats->rx_bytes += skb->len;

	skb_pull(skb, VLAN_HLEN); /* take off the VLAN header (4 bytes currently) */

	/* Need to correct hardware checksum */
	skb_postpull_rcsum(skb, vhdr, VLAN_HLEN);

	/* Ok, lets check to make sure the device (dev) we
	 * came in on is what this VLAN is attached to.
	 */

	if (dev != VLAN_DEV_INFO(skb->dev)->real_dev) {
		rcu_read_unlock();

#ifdef VLAN_DEBUG
		printk(VLAN_DBG "%s: dropping skb: %p because came in on wrong device, dev: %s  real_dev: %s, skb_dev: %s\n",
			__FUNCTION__, skb, dev->name, 
			VLAN_DEV_INFO(skb->dev)->real_dev->name, 
			skb->dev->name);
#endif
		kfree_skb(skb);
		stats->rx_errors++;
		return -1;
	}

	/*
	 * Deal with ingress priority mapping.
	 */
	skb->priority = vlan_get_ingress_priority(skb->dev, ntohs(vhdr->h_vlan_TCI));

#ifdef VLAN_DEBUG
	printk(VLAN_DBG "%s: priority: %lu  for TCI: %hu (hbo)\n",
		__FUNCTION__, (unsigned long)(skb->priority), 
		ntohs(vhdr->h_vlan_TCI));
#endif

	/* The ethernet driver already did the pkt_type calculations
	 * for us...
	 */
	switch (skb->pkt_type) {
	case PACKET_BROADCAST: /* Yeah, stats collect these together.. */
		// stats->broadcast ++; // no such counter :-(
		break;

	case PACKET_MULTICAST:
		stats->multicast++;
		break;

	case PACKET_OTHERHOST: 
		/* Our lower layer thinks this is not local, let's make sure.
		 * This allows the VLAN to have a different MAC than the underlying
		 * device, and still route correctly.
		 */
		if (memcmp(eth_hdr(skb)->h_dest, skb->dev->dev_addr, ETH_ALEN) == 0) {
			/* It is for our (changed) MAC-address! */
			skb->pkt_type = PACKET_HOST;
		}
		break;
	default:
		break;
	};

	/*  Was a VLAN packet, grab the encapsulated protocol, which the layer
	 * three protocols care about.
	 */
	/* proto = get_unaligned(&vhdr->h_vlan_encapsulated_proto); */
	proto = vhdr->h_vlan_encapsulated_proto;

	skb->protocol = proto;
	if (ntohs(proto) >= 1536) {
		/* place it back on the queue to be handled by
		 * true layer 3 protocols.
		 */

		/* See if we are configured to re-write the VLAN header
		 * to make it look like ethernet...
		 */
		skb = vlan_check_reorder_header(skb);

		/* Can be null if skb-clone fails when re-ordering */
		if (skb) {
			netif_rx(skb);
		} else {
			/* TODO:  Add a more specific counter here. */
			stats->rx_errors++;
		}
		rcu_read_unlock();
		return 0;
	}

	rawp = skb->data;

	/*
	 * This is a magic hack to spot IPX packets. Older Novell breaks
	 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
	 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
	 * won't work for fault tolerant netware but does for the rest.
	 */
	if (*(unsigned short *)rawp == 0xFFFF) {
		skb->protocol = __constant_htons(ETH_P_802_3);
		/* place it back on the queue to be handled by true layer 3 protocols.
		 */

		/* See if we are configured to re-write the VLAN header
		 * to make it look like ethernet...
		 */
		skb = vlan_check_reorder_header(skb);

		/* Can be null if skb-clone fails when re-ordering */
		if (skb) {
			netif_rx(skb);
		} else {
			/* TODO:  Add a more specific counter here. */
			stats->rx_errors++;
		}
		rcu_read_unlock();
		return 0;
	}

	/*
	 *	Real 802.2 LLC
	 */
	skb->protocol = __constant_htons(ETH_P_802_2);
	/* place it back on the queue to be handled by upper layer protocols.
	 */

	/* See if we are configured to re-write the VLAN header
	 * to make it look like ethernet...
	 */
	skb = vlan_check_reorder_header(skb);

	/* Can be null if skb-clone fails when re-ordering */
	if (skb) {
		netif_rx(skb);
	} else {
		/* TODO:  Add a more specific counter here. */
		stats->rx_errors++;
	}
	rcu_read_unlock();
	return 0;
}

static inline unsigned short vlan_dev_get_egress_qos_mask(struct net_device* dev,
							  struct sk_buff* skb)
{
	struct vlan_priority_tci_mapping *mp =
		VLAN_DEV_INFO(dev)->egress_priority_map[(skb->priority & 0xF)];

	while (mp) {
		if (mp->priority == skb->priority) {
			return mp->vlan_qos; /* This should already be shifted to mask
					      * correctly with the VLAN's TCI
					      */
		}
		mp = mp->next;
	}
	return 0;
}

/*
 *	Create the VLAN header for an arbitrary protocol layer 
 *
 *	saddr=NULL	means use device source address
 *	daddr=NULL	means leave destination address (eg unresolved arp)
 *
 *  This is called when the SKB is moving down the stack towards the
 *  physical devices.
 */
int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
                         unsigned short type, void *daddr, void *saddr,
                         unsigned len)
{
	struct vlan_hdr *vhdr;
	unsigned short veth_TCI = 0;
	int rc = 0;
	int build_vlan_header = 0;
	struct net_device *vdev = dev; /* save this for the bottom of the method */

#ifdef VLAN_DEBUG
	printk(VLAN_DBG "%s: skb: %p type: %hx len: %x vlan_id: %hx, daddr: %p\n",
		__FUNCTION__, skb, type, len, VLAN_DEV_INFO(dev)->vlan_id, daddr);
#endif

	/* build vlan header only if re_order_header flag is NOT set.  This
	 * fixes some programs that get confused when they see a VLAN device
	 * sending a frame that is VLAN encoded (the consensus is that the VLAN
	 * device should look completely like an Ethernet device when the
	 * REORDER_HEADER flag is set)	The drawback to this is some extra 
	 * header shuffling in the hard_start_xmit.  Users can turn off this
	 * REORDER behaviour with the vconfig tool.
	 */
	build_vlan_header = ((VLAN_DEV_INFO(dev)->flags & 1) == 0);

	if (build_vlan_header) {
		vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);

		/* build the four bytes that make this a VLAN header. */

		/* Now, construct the second two bytes. This field looks something
		 * like:
		 * usr_priority: 3 bits	 (high bits)
		 * CFI		 1 bit
		 * VLAN ID	 12 bits (low bits)
		 *
		 */
		veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
		veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);

		vhdr->h_vlan_TCI = htons(veth_TCI);

		/*
		 *  Set the protocol type.
		 *  For a packet of type ETH_P_802_3 we put the length in here instead.
		 *  It is up to the 802.2 layer to carry protocol information.
		 */

		if (type != ETH_P_802_3) {
			vhdr->h_vlan_encapsulated_proto = htons(type);
		} else {
			vhdr->h_vlan_encapsulated_proto = htons(len);
		}
	}

	/* Before delegating work to the lower layer, enter our MAC-address */
	if (saddr == NULL)
		saddr = dev->dev_addr;

	dev = VLAN_DEV_INFO(dev)->real_dev;

	/* MPLS can send us skbuffs w/out enough space.	 This check will grow the
	 * skb if it doesn't have enough headroom.  Not a beautiful solution, so
	 * I'll tick a counter so that users can know it's happening...	 If they
	 * care...
	 */

	/* NOTE:  This may still break if the underlying device is not the final
	 * device (and thus there are more headers to add...)  It should work for
	 * good-ole-ethernet though.
	 */
	if (skb_headroom(skb) < dev->hard_header_len) {
		struct sk_buff *sk_tmp = skb;
		skb = skb_realloc_headroom(sk_tmp, dev->hard_header_len);
		kfree_skb(sk_tmp);
		if (skb == NULL) {
			struct net_device_stats *stats = vlan_dev_get_stats(vdev);
			stats->tx_dropped++;
			return -ENOMEM;
		}
		VLAN_DEV_INFO(vdev)->cnt_inc_headroom_on_tx++;
#ifdef VLAN_DEBUG
		printk(VLAN_DBG "%s: %s: had to grow skb.\n", __FUNCTION__, vdev->name);
#endif
	}

	if (build_vlan_header) {
		/* Now make the underlying real hard header */
		rc = dev->hard_header(skb, dev, ETH_P_8021Q, daddr, saddr, len + VLAN_HLEN);

		if (rc > 0) {
			rc += VLAN_HLEN;
		} else if (rc < 0) {
			rc -= VLAN_HLEN;
		}
	} else {
		/* If here, then we'll just make a normal looking ethernet frame,
		 * but, the hard_start_xmit method will insert the tag (it has to
		 * be able to do this for bridged and other skbs that don't come
		 * down the protocol stack in an orderly manner.
		 */
		rc = dev->hard_header(skb, dev, type, daddr, saddr, len);
	}

	return rc;
}

int vlan_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct net_device_stats *stats = vlan_dev_get_stats(dev);
	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);

	/* Handle non-VLAN frames if they are sent to us, for example by DHCP.
	 *
	 * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING
	 * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
	 */

	if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
		int orig_headroom = skb_headroom(skb);
		unsigned short veth_TCI;

		/* This is not a VLAN frame...but we can fix that! */
		VLAN_DEV_INFO(dev)->cnt_encap_on_xmit++;

#ifdef VLAN_DEBUG
		printk(VLAN_DBG "%s: proto to encap: 0x%hx (hbo)\n",
			__FUNCTION__, htons(veth->h_vlan_proto));
#endif
		/* Construct the second two bytes. This field looks something
		 * like:
		 * usr_priority: 3 bits	 (high bits)
		 * CFI		 1 bit
		 * VLAN ID	 12 bits (low bits)
		 */
		veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
		veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);

		skb = __vlan_put_tag(skb, veth_TCI);
		if (!skb) {
			stats->tx_dropped++;
			return 0;
		}

		if (orig_headroom < VLAN_HLEN) {
			VLAN_DEV_INFO(dev)->cnt_inc_headroom_on_tx++;
		}
	}

#ifdef VLAN_DEBUG
	printk(VLAN_DBG "%s: about to send skb: %p to dev: %s\n",
		__FUNCTION__, skb, skb->dev->name);
	printk(VLAN_DBG "  %2hx.%2hx.%2hx.%2xh.%2hx.%2hx %2hx.%2hx.%2hx.%2hx.%2hx.%2hx %4hx %4hx %4hx\n",
	       veth->h_dest[0], veth->h_dest[1], veth->h_dest[2], veth->h_dest[3], veth->h_dest[4], veth->h_dest[5],
	       veth->h_source[0], veth->h_source[1], veth->h_source[2], veth->h_source[3], veth->h_source[4], veth->h_source[5],
	       veth->h_vlan_proto, veth->h_vlan_TCI, veth->h_vlan_encapsulated_proto);
#endif

	stats->tx_packets++; /* for statics only */
	stats->tx_bytes += skb->len;

	skb->dev = VLAN_DEV_INFO(dev)->real_dev;
	dev_queue_xmit(skb);

	return 0;
}

int vlan_dev_hwaccel_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct net_device_stats *stats = vlan_dev_get_stats(dev);
	unsigned short veth_TCI;

	/* Construct the second two bytes. This field looks something
	 * like:
	 * usr_priority: 3 bits	 (high bits)
	 * CFI		 1 bit
	 * VLAN ID	 12 bits (low bits)
	 */
	veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
	veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
	skb = __vlan_hwaccel_put_tag(skb, veth_TCI);

	stats->tx_packets++;
	stats->tx_bytes += skb->len;

	skb->dev = VLAN_DEV_INFO(dev)->real_dev;
	dev_queue_xmit(skb);

	return 0;
}

int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
{
	/* TODO: gotta make sure the underlying layer can handle it,
	 * maybe an IFF_VLAN_CAPABLE flag for devices?
	 */
	if (VLAN_DEV_INFO(dev)->real_dev->mtu < new_mtu)
		return -ERANGE;

	dev->mtu = new_mtu;

	return 0;
}

int vlan_dev_set_ingress_priority(char *dev_name, __u32 skb_prio, short vlan_prio)
{
	struct net_device *dev = dev_get_by_name(dev_name);

	if (dev) {
		if (dev->priv_flags & IFF_802_1Q_VLAN) {
			/* see if a priority mapping exists.. */
			VLAN_DEV_INFO(dev)->ingress_priority_map[vlan_prio & 0x7] = skb_prio;
			dev_put(dev);
			return 0;
		}

		dev_put(dev);
	}
	return -EINVAL;
}

int vlan_dev_set_egress_priority(char *dev_name, __u32 skb_prio, short vlan_prio)
{
	struct net_device *dev = dev_get_by_name(dev_name);
	struct vlan_priority_tci_mapping *mp = NULL;
	struct vlan_priority_tci_mapping *np;
   
	if (dev) {
		if (dev->priv_flags & IFF_802_1Q_VLAN) {
			/* See if a priority mapping exists.. */
			mp = VLAN_DEV_INFO(dev)->egress_priority_map[skb_prio & 0xF];
			while (mp) {
				if (mp->priority == skb_prio) {
					mp->vlan_qos = ((vlan_prio << 13) & 0xE000);
					dev_put(dev);
					return 0;
				}
				mp = mp->next;
			}

			/* Create a new mapping then. */
			mp = VLAN_DEV_INFO(dev)->egress_priority_map[skb_prio & 0xF];
			np = kmalloc(sizeof(struct vlan_priority_tci_mapping), GFP_KERNEL);
			if (np) {
				np->next = mp;
				np->priority = skb_prio;
				np->vlan_qos = ((vlan_prio << 13) & 0xE000);
				VLAN_DEV_INFO(dev)->egress_priority_map[skb_prio & 0xF] = np;
				dev_put(dev);
				return 0;
			} else {
				dev_put(dev);
				return -ENOBUFS;
			}
		}
		dev_put(dev);
	}
	return -EINVAL;
}

/* Flags are defined in the vlan_dev_info class in include/linux/if_vlan.h file. */
int vlan_dev_set_vlan_flag(char *dev_name, __u32 flag, short flag_val)
{
	struct net_device *dev = dev_get_by_name(dev_name);

	if (dev) {
		if (dev->priv_flags & IFF_802_1Q_VLAN) {
			/* verify flag is supported */
			if (flag == 1) {
				if (flag_val) {
					VLAN_DEV_INFO(dev)->flags |= 1;
				} else {
					VLAN_DEV_INFO(dev)->flags &= ~1;
				}
				dev_put(dev);
				return 0;
			} else {
				printk(KERN_ERR  "%s: flag %i is not valid.\n",
					__FUNCTION__, (int)(flag));
				dev_put(dev);
				return -EINVAL;
			}
		} else {
			printk(KERN_ERR 
			       "%s: %s is not a vlan device, priv_flags: %hX.\n",
			       __FUNCTION__, dev->name, dev->priv_flags);
			dev_put(dev);
		}
	} else {
		printk(KERN_ERR  "%s: Could not find device: %s\n", 
			__FUNCTION__, dev_name);
	}

	return -EINVAL;
}


int vlan_dev_get_realdev_name(const char *dev_name, char* result)
{
	struct net_device *dev = dev_get_by_name(dev_name);
	int rv = 0;
	if (dev) {
		if (dev->priv_flags & IFF_802_1Q_VLAN) {
			strncpy(result, VLAN_DEV_INFO(dev)->real_dev->name, 23);
			rv = 0;
		} else {
			rv = -EINVAL;
		}
		dev_put(dev);
	} else {
		rv = -ENODEV;
	}
	return rv;
}

int vlan_dev_get_vid(const char *dev_name, unsigned short* result)
{
	struct net_device *dev = dev_get_by_name(dev_name);
	int rv = 0;
	if (dev) {
		if (dev->priv_flags & IFF_802_1Q_VLAN) {
			*result = VLAN_DEV_INFO(dev)->vlan_id;
			rv = 0;
		} else {
			rv = -EINVAL;
		}
		dev_put(dev);
	} else {
		rv = -ENODEV;
	}
	return rv;
}


int vlan_dev_set_mac_address(struct net_device *dev, void *addr_struct_p)
{
	struct sockaddr *addr = (struct sockaddr *)(addr_struct_p);
	int i;

	if (netif_running(dev))
		return -EBUSY;

	memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);

	printk("%s: Setting MAC address to ", dev->name);
	for (i = 0; i < 6; i++)
		printk(" %2.2x", dev->dev_addr[i]);
	printk(".\n");

	if (memcmp(VLAN_DEV_INFO(dev)->real_dev->dev_addr,
		   dev->dev_addr,
		   dev->addr_len) != 0) {
		if (!(VLAN_DEV_INFO(dev)->real_dev->flags & IFF_PROMISC)) {
			int flgs = VLAN_DEV_INFO(dev)->real_dev->flags;

			/* Increment our in-use promiscuity counter */
			dev_set_promiscuity(VLAN_DEV_INFO(dev)->real_dev, 1);

			/* Make PROMISC visible to the user. */
			flgs |= IFF_PROMISC;
			printk("VLAN (%s):  Setting underlying device (%s) to promiscious mode.\n",
			       dev->name, VLAN_DEV_INFO(dev)->real_dev->name);
			dev_change_flags(VLAN_DEV_INFO(dev)->real_dev, flgs);
		}
	} else {
		printk("VLAN (%s):  Underlying device (%s) has same MAC, not checking promiscious mode.\n",
		       dev->name, VLAN_DEV_INFO(dev)->real_dev->name);
	}

	return 0;
}

static inline int vlan_dmi_equals(struct dev_mc_list *dmi1,
                                  struct dev_mc_list *dmi2)
{
	return ((dmi1->dmi_addrlen == dmi2->dmi_addrlen) &&
		(memcmp(dmi1->dmi_addr, dmi2->dmi_addr, dmi1->dmi_addrlen) == 0));
}

/** dmi is a single entry into a dev_mc_list, a single node.  mc_list is
 *  an entire list, and we'll iterate through it.
 */
static int vlan_should_add_mc(struct dev_mc_list *dmi, struct dev_mc_list *mc_list)
{
	struct dev_mc_list *idmi;

	for (idmi = mc_list; idmi != NULL; ) {
		if (vlan_dmi_equals(dmi, idmi)) {
			if (dmi->dmi_users > idmi->dmi_users)
				return 1;
			else
				return 0;
		} else {
			idmi = idmi->next;
		}
	}

	return 1;
}

static inline void vlan_destroy_mc_list(struct dev_mc_list *mc_list)
{
	struct dev_mc_list *dmi = mc_list;
	struct dev_mc_list *next;

	while(dmi) {
		next = dmi->next;
		kfree(dmi);
		dmi = next;
	}
}

static void vlan_copy_mc_list(struct dev_mc_list *mc_list, struct vlan_dev_info *vlan_info)
{
	struct dev_mc_list *dmi, *new_dmi;

	vlan_destroy_mc_list(vlan_info->old_mc_list);
	vlan_info->old_mc_list = NULL;

	for (dmi = mc_list; dmi != NULL; dmi = dmi->next) {
		new_dmi = kmalloc(sizeof(*new_dmi), GFP_ATOMIC);
		if (new_dmi == NULL) {
			printk(KERN_ERR "vlan: cannot allocate memory. "
			       "Multicast may not work properly from now.\n");
			return;
		}

		/* Copy whole structure, then make new 'next' pointer */
		*new_dmi = *dmi;
		new_dmi->next = vlan_info->old_mc_list;
		vlan_info->old_mc_list = new_dmi;
	}
}

static void vlan_flush_mc_list(struct net_device *dev)
{
	struct dev_mc_list *dmi = dev->mc_list;

	while (dmi) {
		printk(KERN_DEBUG "%s: del %.2x:%.2x:%.2x:%.2x:%.2x:%.2x mcast address from vlan interface\n",
		       dev->name,
		       dmi->dmi_addr[0],
		       dmi->dmi_addr[1],
		       dmi->dmi_addr[2],
		       dmi->dmi_addr[3],
		       dmi->dmi_addr[4],
		       dmi->dmi_addr[5]);
		dev_mc_delete(dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
		dmi = dev->mc_list;
	}

	/* dev->mc_list is NULL by the time we get here. */
	vlan_destroy_mc_list(VLAN_DEV_INFO(dev)->old_mc_list);
	VLAN_DEV_INFO(dev)->old_mc_list = NULL;
}

int vlan_dev_open(struct net_device *dev)
{
	if (!(VLAN_DEV_INFO(dev)->real_dev->flags & IFF_UP))
		return -ENETDOWN;

	return 0;
}

int vlan_dev_stop(struct net_device *dev)
{
	vlan_flush_mc_list(dev);
	return 0;
}

int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	struct net_device *real_dev = VLAN_DEV_INFO(dev)->real_dev;
	struct ifreq ifrr;
	int err = -EOPNOTSUPP;

	strncpy(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
	ifrr.ifr_ifru = ifr->ifr_ifru;

	switch(cmd) {
	case SIOCGMIIPHY:
	case SIOCGMIIREG:
	case SIOCSMIIREG:
		if (real_dev->do_ioctl && netif_device_present(real_dev)) 
			err = real_dev->do_ioctl(real_dev, &ifrr, cmd);
		break;

	case SIOCETHTOOL:
		err = dev_ethtool(&ifrr);
	}

	if (!err) 
		ifr->ifr_ifru = ifrr.ifr_ifru;

	return err;
}

/** Taken from Gleb + Lennert's VLAN code, and modified... */
void vlan_dev_set_multicast_list(struct net_device *vlan_dev)
{
	struct dev_mc_list *dmi;
	struct net_device *real_dev;
	int inc;

	if (vlan_dev && (vlan_dev->priv_flags & IFF_802_1Q_VLAN)) {
		/* Then it's a real vlan device, as far as we can tell.. */
		real_dev = VLAN_DEV_INFO(vlan_dev)->real_dev;

		/* compare the current promiscuity to the last promisc we had.. */
		inc = vlan_dev->promiscuity - VLAN_DEV_INFO(vlan_dev)->old_promiscuity;
		if (inc) {
			printk(KERN_INFO "%s: dev_set_promiscuity(master, %d)\n",
			       vlan_dev->name, inc);
			dev_set_promiscuity(real_dev, inc); /* found in dev.c */
			VLAN_DEV_INFO(vlan_dev)->old_promiscuity = vlan_dev->promiscuity;
		}

		inc = vlan_dev->allmulti - VLAN_DEV_INFO(vlan_dev)->old_allmulti;
		if (inc) {
			printk(KERN_INFO "%s: dev_set_allmulti(master, %d)\n",
			       vlan_dev->name, inc);
			dev_set_allmulti(real_dev, inc); /* dev.c */
			VLAN_DEV_INFO(vlan_dev)->old_allmulti = vlan_dev->allmulti;
		}

		/* looking for addresses to add to master's list */
		for (dmi = vlan_dev->mc_list; dmi != NULL; dmi = dmi->next) {
			if (vlan_should_add_mc(dmi, VLAN_DEV_INFO(vlan_dev)->old_mc_list)) {
				dev_mc_add(real_dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
				printk(KERN_DEBUG "%s: add %.2x:%.2x:%.2x:%.2x:%.2x:%.2x mcast address to master interface\n",
				       vlan_dev->name,
				       dmi->dmi_addr[0],
				       dmi->dmi_addr[1],
				       dmi->dmi_addr[2],
				       dmi->dmi_addr[3],
				       dmi->dmi_addr[4],
				       dmi->dmi_addr[5]);
			}
		}

		/* looking for addresses to delete from master's list */
		for (dmi = VLAN_DEV_INFO(vlan_dev)->old_mc_list; dmi != NULL; dmi = dmi->next) {
			if (vlan_should_add_mc(dmi, vlan_dev->mc_list)) {
				/* if we think we should add it to the new list, then we should really
				 * delete it from the real list on the underlying device.
				 */
				dev_mc_delete(real_dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
				printk(KERN_DEBUG "%s: del %.2x:%.2x:%.2x:%.2x:%.2x:%.2x mcast address from master interface\n",
				       vlan_dev->name,
				       dmi->dmi_addr[0],
				       dmi->dmi_addr[1],
				       dmi->dmi_addr[2],
				       dmi->dmi_addr[3],
				       dmi->dmi_addr[4],
				       dmi->dmi_addr[5]);
			}
		}

		/* save multicast list */
		vlan_copy_mc_list(vlan_dev->mc_list, VLAN_DEV_INFO(vlan_dev));
	}
}