4f6ede752a37d969bad8aea8d654c1f6a08e19cc
[linux-2.6.git] / net / 8021q / vlan_dev.c
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 & 1) {
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         build_vlan_header = ((VLAN_DEV_INFO(dev)->flags & 1) == 0);
354
355         if (build_vlan_header) {
356                 vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);
357
358                 /* build the four bytes that make this a VLAN header. */
359
360                 /* Now, construct the second two bytes. This field looks something
361                  * like:
362                  * usr_priority: 3 bits  (high bits)
363                  * CFI           1 bit
364                  * VLAN ID       12 bits (low bits)
365                  *
366                  */
367                 veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
368                 veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
369
370                 vhdr->h_vlan_TCI = htons(veth_TCI);
371
372                 /*
373                  *  Set the protocol type.
374                  *  For a packet of type ETH_P_802_3 we put the length in here instead.
375                  *  It is up to the 802.2 layer to carry protocol information.
376                  */
377
378                 if (type != ETH_P_802_3) {
379                         vhdr->h_vlan_encapsulated_proto = htons(type);
380                 } else {
381                         vhdr->h_vlan_encapsulated_proto = htons(len);
382                 }
383
384                 skb->protocol = htons(ETH_P_8021Q);
385                 skb_reset_network_header(skb);
386         }
387
388         /* Before delegating work to the lower layer, enter our MAC-address */
389         if (saddr == NULL)
390                 saddr = dev->dev_addr;
391
392         dev = VLAN_DEV_INFO(dev)->real_dev;
393
394         /* MPLS can send us skbuffs w/out enough space.  This check will grow the
395          * skb if it doesn't have enough headroom.  Not a beautiful solution, so
396          * I'll tick a counter so that users can know it's happening...  If they
397          * care...
398          */
399
400         /* NOTE:  This may still break if the underlying device is not the final
401          * device (and thus there are more headers to add...)  It should work for
402          * good-ole-ethernet though.
403          */
404         if (skb_headroom(skb) < dev->hard_header_len) {
405                 struct sk_buff *sk_tmp = skb;
406                 skb = skb_realloc_headroom(sk_tmp, dev->hard_header_len);
407                 kfree_skb(sk_tmp);
408                 if (skb == NULL) {
409                         struct net_device_stats *stats = vlan_dev_get_stats(vdev);
410                         stats->tx_dropped++;
411                         return -ENOMEM;
412                 }
413                 VLAN_DEV_INFO(vdev)->cnt_inc_headroom_on_tx++;
414 #ifdef VLAN_DEBUG
415                 printk(VLAN_DBG "%s: %s: had to grow skb.\n", __FUNCTION__, vdev->name);
416 #endif
417         }
418
419         if (build_vlan_header) {
420                 /* Now make the underlying real hard header */
421                 rc = dev->hard_header(skb, dev, ETH_P_8021Q, daddr, saddr, len + VLAN_HLEN);
422
423                 if (rc > 0) {
424                         rc += VLAN_HLEN;
425                 } else if (rc < 0) {
426                         rc -= VLAN_HLEN;
427                 }
428         } else {
429                 /* If here, then we'll just make a normal looking ethernet frame,
430                  * but, the hard_start_xmit method will insert the tag (it has to
431                  * be able to do this for bridged and other skbs that don't come
432                  * down the protocol stack in an orderly manner.
433                  */
434                 rc = dev->hard_header(skb, dev, type, daddr, saddr, len);
435         }
436
437         return rc;
438 }
439
440 int vlan_dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
441 {
442         struct net_device_stats *stats = vlan_dev_get_stats(dev);
443         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)(skb->data);
444
445         /* Handle non-VLAN frames if they are sent to us, for example by DHCP.
446          *
447          * NOTE: THIS ASSUMES DIX ETHERNET, SPECIFICALLY NOT SUPPORTING
448          * OTHER THINGS LIKE FDDI/TokenRing/802.3 SNAPs...
449          */
450
451         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
452                 int orig_headroom = skb_headroom(skb);
453                 unsigned short veth_TCI;
454
455                 /* This is not a VLAN frame...but we can fix that! */
456                 VLAN_DEV_INFO(dev)->cnt_encap_on_xmit++;
457
458 #ifdef VLAN_DEBUG
459                 printk(VLAN_DBG "%s: proto to encap: 0x%hx (hbo)\n",
460                         __FUNCTION__, htons(veth->h_vlan_proto));
461 #endif
462                 /* Construct the second two bytes. This field looks something
463                  * like:
464                  * usr_priority: 3 bits  (high bits)
465                  * CFI           1 bit
466                  * VLAN ID       12 bits (low bits)
467                  */
468                 veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
469                 veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
470
471                 skb = __vlan_put_tag(skb, veth_TCI);
472                 if (!skb) {
473                         stats->tx_dropped++;
474                         return 0;
475                 }
476
477                 if (orig_headroom < VLAN_HLEN) {
478                         VLAN_DEV_INFO(dev)->cnt_inc_headroom_on_tx++;
479                 }
480         }
481
482 #ifdef VLAN_DEBUG
483         printk(VLAN_DBG "%s: about to send skb: %p to dev: %s\n",
484                 __FUNCTION__, skb, skb->dev->name);
485         printk(VLAN_DBG "  %2hx.%2hx.%2hx.%2xh.%2hx.%2hx %2hx.%2hx.%2hx.%2hx.%2hx.%2hx %4hx %4hx %4hx\n",
486                veth->h_dest[0], veth->h_dest[1], veth->h_dest[2], veth->h_dest[3], veth->h_dest[4], veth->h_dest[5],
487                veth->h_source[0], veth->h_source[1], veth->h_source[2], veth->h_source[3], veth->h_source[4], veth->h_source[5],
488                veth->h_vlan_proto, veth->h_vlan_TCI, veth->h_vlan_encapsulated_proto);
489 #endif
490
491         stats->tx_packets++; /* for statics only */
492         stats->tx_bytes += skb->len;
493
494         skb->dev = VLAN_DEV_INFO(dev)->real_dev;
495         dev_queue_xmit(skb);
496
497         return 0;
498 }
499
500 int vlan_dev_hwaccel_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
501 {
502         struct net_device_stats *stats = vlan_dev_get_stats(dev);
503         unsigned short veth_TCI;
504
505         /* Construct the second two bytes. This field looks something
506          * like:
507          * usr_priority: 3 bits  (high bits)
508          * CFI           1 bit
509          * VLAN ID       12 bits (low bits)
510          */
511         veth_TCI = VLAN_DEV_INFO(dev)->vlan_id;
512         veth_TCI |= vlan_dev_get_egress_qos_mask(dev, skb);
513         skb = __vlan_hwaccel_put_tag(skb, veth_TCI);
514
515         stats->tx_packets++;
516         stats->tx_bytes += skb->len;
517
518         skb->dev = VLAN_DEV_INFO(dev)->real_dev;
519         dev_queue_xmit(skb);
520
521         return 0;
522 }
523
524 int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
525 {
526         /* TODO: gotta make sure the underlying layer can handle it,
527          * maybe an IFF_VLAN_CAPABLE flag for devices?
528          */
529         if (VLAN_DEV_INFO(dev)->real_dev->mtu < new_mtu)
530                 return -ERANGE;
531
532         dev->mtu = new_mtu;
533
534         return 0;
535 }
536
537 void vlan_dev_set_ingress_priority(const struct net_device *dev,
538                                    u32 skb_prio, short vlan_prio)
539 {
540         struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
541
542         if (vlan->ingress_priority_map[vlan_prio & 0x7] && !skb_prio)
543                 vlan->nr_ingress_mappings--;
544         else if (!vlan->ingress_priority_map[vlan_prio & 0x7] && skb_prio)
545                 vlan->nr_ingress_mappings++;
546
547         vlan->ingress_priority_map[vlan_prio & 0x7] = skb_prio;
548 }
549
550 int vlan_dev_set_egress_priority(const struct net_device *dev,
551                                  u32 skb_prio, short vlan_prio)
552 {
553         struct vlan_dev_info *vlan = VLAN_DEV_INFO(dev);
554         struct vlan_priority_tci_mapping *mp = NULL;
555         struct vlan_priority_tci_mapping *np;
556         u32 vlan_qos = (vlan_prio << 13) & 0xE000;
557
558         /* See if a priority mapping exists.. */
559         mp = vlan->egress_priority_map[skb_prio & 0xF];
560         while (mp) {
561                 if (mp->priority == skb_prio) {
562                         if (mp->vlan_qos && !vlan_qos)
563                                 vlan->nr_egress_mappings--;
564                         else if (!mp->vlan_qos && vlan_qos)
565                                 vlan->nr_egress_mappings++;
566                         mp->vlan_qos = vlan_qos;
567                         return 0;
568                 }
569                 mp = mp->next;
570         }
571
572         /* Create a new mapping then. */
573         mp = vlan->egress_priority_map[skb_prio & 0xF];
574         np = kmalloc(sizeof(struct vlan_priority_tci_mapping), GFP_KERNEL);
575         if (!np)
576                 return -ENOBUFS;
577
578         np->next = mp;
579         np->priority = skb_prio;
580         np->vlan_qos = vlan_qos;
581         vlan->egress_priority_map[skb_prio & 0xF] = np;
582         if (vlan_qos)
583                 vlan->nr_egress_mappings++;
584         return 0;
585 }
586
587 /* Flags are defined in the vlan_dev_info class in include/linux/if_vlan.h file. */
588 int vlan_dev_set_vlan_flag(const struct net_device *dev,
589                            u32 flag, short flag_val)
590 {
591         /* verify flag is supported */
592         if (flag == 1) {
593                 if (flag_val) {
594                         VLAN_DEV_INFO(dev)->flags |= 1;
595                 } else {
596                         VLAN_DEV_INFO(dev)->flags &= ~1;
597                 }
598                 return 0;
599         }
600         printk(KERN_ERR "%s: flag %i is not valid.\n", __FUNCTION__, flag);
601         return -EINVAL;
602 }
603
604 void vlan_dev_get_realdev_name(const struct net_device *dev, char *result)
605 {
606         strncpy(result, VLAN_DEV_INFO(dev)->real_dev->name, 23);
607 }
608
609 void vlan_dev_get_vid(const struct net_device *dev, unsigned short *result)
610 {
611         *result = VLAN_DEV_INFO(dev)->vlan_id;
612 }
613
614 int vlan_dev_set_mac_address(struct net_device *dev, void *addr_struct_p)
615 {
616         struct sockaddr *addr = (struct sockaddr *)(addr_struct_p);
617         int i;
618
619         if (netif_running(dev))
620                 return -EBUSY;
621
622         memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
623
624         printk("%s: Setting MAC address to ", dev->name);
625         for (i = 0; i < 6; i++)
626                 printk(" %2.2x", dev->dev_addr[i]);
627         printk(".\n");
628
629         if (memcmp(VLAN_DEV_INFO(dev)->real_dev->dev_addr,
630                    dev->dev_addr,
631                    dev->addr_len) != 0) {
632                 if (!(VLAN_DEV_INFO(dev)->real_dev->flags & IFF_PROMISC)) {
633                         int flgs = VLAN_DEV_INFO(dev)->real_dev->flags;
634
635                         /* Increment our in-use promiscuity counter */
636                         dev_set_promiscuity(VLAN_DEV_INFO(dev)->real_dev, 1);
637
638                         /* Make PROMISC visible to the user. */
639                         flgs |= IFF_PROMISC;
640                         printk("VLAN (%s):  Setting underlying device (%s) to promiscious mode.\n",
641                                dev->name, VLAN_DEV_INFO(dev)->real_dev->name);
642                         dev_change_flags(VLAN_DEV_INFO(dev)->real_dev, flgs);
643                 }
644         } else {
645                 printk("VLAN (%s):  Underlying device (%s) has same MAC, not checking promiscious mode.\n",
646                        dev->name, VLAN_DEV_INFO(dev)->real_dev->name);
647         }
648
649         return 0;
650 }
651
652 static inline int vlan_dmi_equals(struct dev_mc_list *dmi1,
653                                   struct dev_mc_list *dmi2)
654 {
655         return ((dmi1->dmi_addrlen == dmi2->dmi_addrlen) &&
656                 (memcmp(dmi1->dmi_addr, dmi2->dmi_addr, dmi1->dmi_addrlen) == 0));
657 }
658
659 /** dmi is a single entry into a dev_mc_list, a single node.  mc_list is
660  *  an entire list, and we'll iterate through it.
661  */
662 static int vlan_should_add_mc(struct dev_mc_list *dmi, struct dev_mc_list *mc_list)
663 {
664         struct dev_mc_list *idmi;
665
666         for (idmi = mc_list; idmi != NULL; ) {
667                 if (vlan_dmi_equals(dmi, idmi)) {
668                         if (dmi->dmi_users > idmi->dmi_users)
669                                 return 1;
670                         else
671                                 return 0;
672                 } else {
673                         idmi = idmi->next;
674                 }
675         }
676
677         return 1;
678 }
679
680 static inline void vlan_destroy_mc_list(struct dev_mc_list *mc_list)
681 {
682         struct dev_mc_list *dmi = mc_list;
683         struct dev_mc_list *next;
684
685         while(dmi) {
686                 next = dmi->next;
687                 kfree(dmi);
688                 dmi = next;
689         }
690 }
691
692 static void vlan_copy_mc_list(struct dev_mc_list *mc_list, struct vlan_dev_info *vlan_info)
693 {
694         struct dev_mc_list *dmi, *new_dmi;
695
696         vlan_destroy_mc_list(vlan_info->old_mc_list);
697         vlan_info->old_mc_list = NULL;
698
699         for (dmi = mc_list; dmi != NULL; dmi = dmi->next) {
700                 new_dmi = kmalloc(sizeof(*new_dmi), GFP_ATOMIC);
701                 if (new_dmi == NULL) {
702                         printk(KERN_ERR "vlan: cannot allocate memory. "
703                                "Multicast may not work properly from now.\n");
704                         return;
705                 }
706
707                 /* Copy whole structure, then make new 'next' pointer */
708                 *new_dmi = *dmi;
709                 new_dmi->next = vlan_info->old_mc_list;
710                 vlan_info->old_mc_list = new_dmi;
711         }
712 }
713
714 static void vlan_flush_mc_list(struct net_device *dev)
715 {
716         struct dev_mc_list *dmi = dev->mc_list;
717
718         while (dmi) {
719                 printk(KERN_DEBUG "%s: del %.2x:%.2x:%.2x:%.2x:%.2x:%.2x mcast address from vlan interface\n",
720                        dev->name,
721                        dmi->dmi_addr[0],
722                        dmi->dmi_addr[1],
723                        dmi->dmi_addr[2],
724                        dmi->dmi_addr[3],
725                        dmi->dmi_addr[4],
726                        dmi->dmi_addr[5]);
727                 dev_mc_delete(dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
728                 dmi = dev->mc_list;
729         }
730
731         /* dev->mc_list is NULL by the time we get here. */
732         vlan_destroy_mc_list(VLAN_DEV_INFO(dev)->old_mc_list);
733         VLAN_DEV_INFO(dev)->old_mc_list = NULL;
734 }
735
736 int vlan_dev_open(struct net_device *dev)
737 {
738         if (!(VLAN_DEV_INFO(dev)->real_dev->flags & IFF_UP))
739                 return -ENETDOWN;
740
741         return 0;
742 }
743
744 int vlan_dev_stop(struct net_device *dev)
745 {
746         vlan_flush_mc_list(dev);
747         return 0;
748 }
749
750 int vlan_dev_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
751 {
752         struct net_device *real_dev = VLAN_DEV_INFO(dev)->real_dev;
753         struct ifreq ifrr;
754         int err = -EOPNOTSUPP;
755
756         strncpy(ifrr.ifr_name, real_dev->name, IFNAMSIZ);
757         ifrr.ifr_ifru = ifr->ifr_ifru;
758
759         switch(cmd) {
760         case SIOCGMIIPHY:
761         case SIOCGMIIREG:
762         case SIOCSMIIREG:
763                 if (real_dev->do_ioctl && netif_device_present(real_dev))
764                         err = real_dev->do_ioctl(real_dev, &ifrr, cmd);
765                 break;
766
767         case SIOCETHTOOL:
768                 err = dev_ethtool(&ifrr);
769         }
770
771         if (!err)
772                 ifr->ifr_ifru = ifrr.ifr_ifru;
773
774         return err;
775 }
776
777 /** Taken from Gleb + Lennert's VLAN code, and modified... */
778 void vlan_dev_set_multicast_list(struct net_device *vlan_dev)
779 {
780         struct dev_mc_list *dmi;
781         struct net_device *real_dev;
782         int inc;
783
784         if (vlan_dev && (vlan_dev->priv_flags & IFF_802_1Q_VLAN)) {
785                 /* Then it's a real vlan device, as far as we can tell.. */
786                 real_dev = VLAN_DEV_INFO(vlan_dev)->real_dev;
787
788                 /* compare the current promiscuity to the last promisc we had.. */
789                 inc = vlan_dev->promiscuity - VLAN_DEV_INFO(vlan_dev)->old_promiscuity;
790                 if (inc) {
791                         printk(KERN_INFO "%s: dev_set_promiscuity(master, %d)\n",
792                                vlan_dev->name, inc);
793                         dev_set_promiscuity(real_dev, inc); /* found in dev.c */
794                         VLAN_DEV_INFO(vlan_dev)->old_promiscuity = vlan_dev->promiscuity;
795                 }
796
797                 inc = vlan_dev->allmulti - VLAN_DEV_INFO(vlan_dev)->old_allmulti;
798                 if (inc) {
799                         printk(KERN_INFO "%s: dev_set_allmulti(master, %d)\n",
800                                vlan_dev->name, inc);
801                         dev_set_allmulti(real_dev, inc); /* dev.c */
802                         VLAN_DEV_INFO(vlan_dev)->old_allmulti = vlan_dev->allmulti;
803                 }
804
805                 /* looking for addresses to add to master's list */
806                 for (dmi = vlan_dev->mc_list; dmi != NULL; dmi = dmi->next) {
807                         if (vlan_should_add_mc(dmi, VLAN_DEV_INFO(vlan_dev)->old_mc_list)) {
808                                 dev_mc_add(real_dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
809                                 printk(KERN_DEBUG "%s: add %.2x:%.2x:%.2x:%.2x:%.2x:%.2x mcast address to master interface\n",
810                                        vlan_dev->name,
811                                        dmi->dmi_addr[0],
812                                        dmi->dmi_addr[1],
813                                        dmi->dmi_addr[2],
814                                        dmi->dmi_addr[3],
815                                        dmi->dmi_addr[4],
816                                        dmi->dmi_addr[5]);
817                         }
818                 }
819
820                 /* looking for addresses to delete from master's list */
821                 for (dmi = VLAN_DEV_INFO(vlan_dev)->old_mc_list; dmi != NULL; dmi = dmi->next) {
822                         if (vlan_should_add_mc(dmi, vlan_dev->mc_list)) {
823                                 /* if we think we should add it to the new list, then we should really
824                                  * delete it from the real list on the underlying device.
825                                  */
826                                 dev_mc_delete(real_dev, dmi->dmi_addr, dmi->dmi_addrlen, 0);
827                                 printk(KERN_DEBUG "%s: del %.2x:%.2x:%.2x:%.2x:%.2x:%.2x mcast address from master interface\n",
828                                        vlan_dev->name,
829                                        dmi->dmi_addr[0],
830                                        dmi->dmi_addr[1],
831                                        dmi->dmi_addr[2],
832                                        dmi->dmi_addr[3],
833                                        dmi->dmi_addr[4],
834                                        dmi->dmi_addr[5]);
835                         }
836                 }
837
838                 /* save multicast list */
839                 vlan_copy_mc_list(vlan_dev->mc_list, VLAN_DEV_INFO(vlan_dev));
840         }
841 }