1/*
2 * VLAN An implementation of 802.1Q VLAN tagging.
3 *
4 * Authors: Ben Greear <greearb@candelatech.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 */
12#ifndef _LINUX_IF_VLAN_H_
13#define _LINUX_IF_VLAN_H_
14
15#include <linux/netdevice.h>
16#include <linux/etherdevice.h>
17#include <linux/rtnetlink.h>
18#include <linux/bug.h>
19#include <uapi/linux/if_vlan.h>
20
21#define VLAN_HLEN 4 /* The additional bytes required by VLAN
22 * (in addition to the Ethernet header)
23 */
24#define VLAN_ETH_HLEN 18 /* Total octets in header. */
25#define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
26
27/*
28 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
29 */
30#define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
31#define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
32
33/*
34 * struct vlan_hdr - vlan header
35 * @h_vlan_TCI: priority and VLAN ID
36 * @h_vlan_encapsulated_proto: packet type ID or len
37 */
38struct vlan_hdr {
39 __be16 h_vlan_TCI;
40 __be16 h_vlan_encapsulated_proto;
41};
42
43/**
44 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
45 * @h_dest: destination ethernet address
46 * @h_source: source ethernet address
47 * @h_vlan_proto: ethernet protocol
48 * @h_vlan_TCI: priority and VLAN ID
49 * @h_vlan_encapsulated_proto: packet type ID or len
50 */
51struct vlan_ethhdr {
52 unsigned char h_dest[ETH_ALEN];
53 unsigned char h_source[ETH_ALEN];
54 __be16 h_vlan_proto;
55 __be16 h_vlan_TCI;
56 __be16 h_vlan_encapsulated_proto;
57};
58
59#include <linux/skbuff.h>
60
61static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
62{
63 return (struct vlan_ethhdr *)skb_mac_header(skb);
64}
65
66#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
67#define VLAN_PRIO_SHIFT 13
68#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator / Drop Eligible Indicator */
69#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
70#define VLAN_N_VID 4096
71
72/* found in socket.c */
73extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
74
75static inline bool is_vlan_dev(const struct net_device *dev)
76{
77 return dev->priv_flags & IFF_802_1Q_VLAN;
78}
79
80#define skb_vlan_tag_present(__skb) ((__skb)->vlan_present)
81#define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci)
82#define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK)
83#define skb_vlan_tag_get_cfi(__skb) (!!((__skb)->vlan_tci & VLAN_CFI_MASK))
84#define skb_vlan_tag_get_prio(__skb) (((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT)
85
86static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
87{
88 ASSERT_RTNL();
89 return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev));
90}
91
92static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev)
93{
94 ASSERT_RTNL();
95 call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev);
96}
97
98static inline int vlan_get_rx_stag_filter_info(struct net_device *dev)
99{
100 ASSERT_RTNL();
101 return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev));
102}
103
104static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev)
105{
106 ASSERT_RTNL();
107 call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev);
108}
109
110/**
111 * struct vlan_pcpu_stats - VLAN percpu rx/tx stats
112 * @rx_packets: number of received packets
113 * @rx_bytes: number of received bytes
114 * @rx_multicast: number of received multicast packets
115 * @tx_packets: number of transmitted packets
116 * @tx_bytes: number of transmitted bytes
117 * @syncp: synchronization point for 64bit counters
118 * @rx_errors: number of rx errors
119 * @tx_dropped: number of tx drops
120 */
121struct vlan_pcpu_stats {
122 u64 rx_packets;
123 u64 rx_bytes;
124 u64 rx_multicast;
125 u64 tx_packets;
126 u64 tx_bytes;
127 struct u64_stats_sync syncp;
128 u32 rx_errors;
129 u32 tx_dropped;
130};
131
132#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
133
134extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
135 __be16 vlan_proto, u16 vlan_id);
136extern int vlan_for_each(struct net_device *dev,
137 int (*action)(struct net_device *dev, int vid,
138 void *arg), void *arg);
139extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
140extern u16 vlan_dev_vlan_id(const struct net_device *dev);
141extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
142
143/**
144 * struct vlan_priority_tci_mapping - vlan egress priority mappings
145 * @priority: skb priority
146 * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
147 * @next: pointer to next struct
148 */
149struct vlan_priority_tci_mapping {
150 u32 priority;
151 u16 vlan_qos;
152 struct vlan_priority_tci_mapping *next;
153};
154
155struct proc_dir_entry;
156struct netpoll;
157
158/**
159 * struct vlan_dev_priv - VLAN private device data
160 * @nr_ingress_mappings: number of ingress priority mappings
161 * @ingress_priority_map: ingress priority mappings
162 * @nr_egress_mappings: number of egress priority mappings
163 * @egress_priority_map: hash of egress priority mappings
164 * @vlan_proto: VLAN encapsulation protocol
165 * @vlan_id: VLAN identifier
166 * @flags: device flags
167 * @real_dev: underlying netdevice
168 * @real_dev_addr: address of underlying netdevice
169 * @dent: proc dir entry
170 * @vlan_pcpu_stats: ptr to percpu rx stats
171 */
172struct vlan_dev_priv {
173 unsigned int nr_ingress_mappings;
174 u32 ingress_priority_map[8];
175 unsigned int nr_egress_mappings;
176 struct vlan_priority_tci_mapping *egress_priority_map[16];
177
178 __be16 vlan_proto;
179 u16 vlan_id;
180 u16 flags;
181
182 struct net_device *real_dev;
183 unsigned char real_dev_addr[ETH_ALEN];
184
185 struct proc_dir_entry *dent;
186 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats;
187#ifdef CONFIG_NET_POLL_CONTROLLER
188 struct netpoll *netpoll;
189#endif
190 unsigned int nest_level;
191};
192
193static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
194{
195 return netdev_priv(dev);
196}
197
198static inline u16
199vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
200{
201 struct vlan_priority_tci_mapping *mp;
202
203 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
204
205 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
206 while (mp) {
207 if (mp->priority == skprio) {
208 return mp->vlan_qos; /* This should already be shifted
209 * to mask correctly with the
210 * VLAN's TCI */
211 }
212 mp = mp->next;
213 }
214 return 0;
215}
216
217extern bool vlan_do_receive(struct sk_buff **skb);
218
219extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
220extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
221
222extern int vlan_vids_add_by_dev(struct net_device *dev,
223 const struct net_device *by_dev);
224extern void vlan_vids_del_by_dev(struct net_device *dev,
225 const struct net_device *by_dev);
226
227extern bool vlan_uses_dev(const struct net_device *dev);
228
229static inline int vlan_get_encap_level(struct net_device *dev)
230{
231 BUG_ON(!is_vlan_dev(dev));
232 return vlan_dev_priv(dev)->nest_level;
233}
234#else
235static inline struct net_device *
236__vlan_find_dev_deep_rcu(struct net_device *real_dev,
237 __be16 vlan_proto, u16 vlan_id)
238{
239 return NULL;
240}
241
242static inline int
243vlan_for_each(struct net_device *dev,
244 int (*action)(struct net_device *dev, int vid, void *arg),
245 void *arg)
246{
247 return 0;
248}
249
250static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
251{
252 BUG();
253 return NULL;
254}
255
256static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
257{
258 BUG();
259 return 0;
260}
261
262static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
263{
264 BUG();
265 return 0;
266}
267
268static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
269 u32 skprio)
270{
271 return 0;
272}
273
274static inline bool vlan_do_receive(struct sk_buff **skb)
275{
276 return false;
277}
278
279static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
280{
281 return 0;
282}
283
284static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
285{
286}
287
288static inline int vlan_vids_add_by_dev(struct net_device *dev,
289 const struct net_device *by_dev)
290{
291 return 0;
292}
293
294static inline void vlan_vids_del_by_dev(struct net_device *dev,
295 const struct net_device *by_dev)
296{
297}
298
299static inline bool vlan_uses_dev(const struct net_device *dev)
300{
301 return false;
302}
303static inline int vlan_get_encap_level(struct net_device *dev)
304{
305 BUG();
306 return 0;
307}
308#endif
309
310/**
311 * eth_type_vlan - check for valid vlan ether type.
312 * @ethertype: ether type to check
313 *
314 * Returns true if the ether type is a vlan ether type.
315 */
316static inline bool eth_type_vlan(__be16 ethertype)
317{
318 switch (ethertype) {
319 case htons(ETH_P_8021Q):
320 case htons(ETH_P_8021AD):
321 return true;
322 default:
323 return false;
324 }
325}
326
327static inline bool vlan_hw_offload_capable(netdev_features_t features,
328 __be16 proto)
329{
330 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
331 return true;
332 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
333 return true;
334 return false;
335}
336
337/**
338 * __vlan_insert_inner_tag - inner VLAN tag inserting
339 * @skb: skbuff to tag
340 * @vlan_proto: VLAN encapsulation protocol
341 * @vlan_tci: VLAN TCI to insert
342 * @mac_len: MAC header length including outer vlan headers
343 *
344 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
345 * Returns error if skb_cow_head fails.
346 *
347 * Does not change skb->protocol so this function can be used during receive.
348 */
349static inline int __vlan_insert_inner_tag(struct sk_buff *skb,
350 __be16 vlan_proto, u16 vlan_tci,
351 unsigned int mac_len)
352{
353 struct vlan_ethhdr *veth;
354
355 if (skb_cow_head(skb, VLAN_HLEN) < 0)
356 return -ENOMEM;
357
358 skb_push(skb, VLAN_HLEN);
359
360 /* Move the mac header sans proto to the beginning of the new header. */
361 if (likely(mac_len > ETH_TLEN))
362 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
363 skb->mac_header -= VLAN_HLEN;
364
365 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN);
366
367 /* first, the ethernet type */
368 if (likely(mac_len >= ETH_TLEN)) {
369 /* h_vlan_encapsulated_proto should already be populated, and
370 * skb->data has space for h_vlan_proto
371 */
372 veth->h_vlan_proto = vlan_proto;
373 } else {
374 /* h_vlan_encapsulated_proto should not be populated, and
375 * skb->data has no space for h_vlan_proto
376 */
377 veth->h_vlan_encapsulated_proto = skb->protocol;
378 }
379
380 /* now, the TCI */
381 veth->h_vlan_TCI = htons(vlan_tci);
382
383 return 0;
384}
385
386/**
387 * __vlan_insert_tag - regular VLAN tag inserting
388 * @skb: skbuff to tag
389 * @vlan_proto: VLAN encapsulation protocol
390 * @vlan_tci: VLAN TCI to insert
391 *
392 * Inserts the VLAN tag into @skb as part of the payload
393 * Returns error if skb_cow_head fails.
394 *
395 * Does not change skb->protocol so this function can be used during receive.
396 */
397static inline int __vlan_insert_tag(struct sk_buff *skb,
398 __be16 vlan_proto, u16 vlan_tci)
399{
400 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
401}
402
403/**
404 * vlan_insert_inner_tag - inner VLAN tag inserting
405 * @skb: skbuff to tag
406 * @vlan_proto: VLAN encapsulation protocol
407 * @vlan_tci: VLAN TCI to insert
408 * @mac_len: MAC header length including outer vlan headers
409 *
410 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
411 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
412 *
413 * Following the skb_unshare() example, in case of error, the calling function
414 * doesn't have to worry about freeing the original skb.
415 *
416 * Does not change skb->protocol so this function can be used during receive.
417 */
418static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb,
419 __be16 vlan_proto,
420 u16 vlan_tci,
421 unsigned int mac_len)
422{
423 int err;
424
425 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len);
426 if (err) {
427 dev_kfree_skb_any(skb);
428 return NULL;
429 }
430 return skb;
431}
432
433/**
434 * vlan_insert_tag - regular VLAN tag inserting
435 * @skb: skbuff to tag
436 * @vlan_proto: VLAN encapsulation protocol
437 * @vlan_tci: VLAN TCI to insert
438 *
439 * Inserts the VLAN tag into @skb as part of the payload
440 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
441 *
442 * Following the skb_unshare() example, in case of error, the calling function
443 * doesn't have to worry about freeing the original skb.
444 *
445 * Does not change skb->protocol so this function can be used during receive.
446 */
447static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
448 __be16 vlan_proto, u16 vlan_tci)
449{
450 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
451}
452
453/**
454 * vlan_insert_tag_set_proto - regular VLAN tag inserting
455 * @skb: skbuff to tag
456 * @vlan_proto: VLAN encapsulation protocol
457 * @vlan_tci: VLAN TCI to insert
458 *
459 * Inserts the VLAN tag into @skb as part of the payload
460 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
461 *
462 * Following the skb_unshare() example, in case of error, the calling function
463 * doesn't have to worry about freeing the original skb.
464 */
465static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
466 __be16 vlan_proto,
467 u16 vlan_tci)
468{
469 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
470 if (skb)
471 skb->protocol = vlan_proto;
472 return skb;
473}
474
475/**
476 * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info
477 * @skb: skbuff to clear
478 *
479 * Clears the VLAN information from @skb
480 */
481static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
482{
483 skb->vlan_present = 0;
484}
485
486/**
487 * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb
488 * @dst: skbuff to copy to
489 * @src: skbuff to copy from
490 *
491 * Copies VLAN information from @src to @dst (for branchless code)
492 */
493static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src)
494{
495 dst->vlan_present = src->vlan_present;
496 dst->vlan_proto = src->vlan_proto;
497 dst->vlan_tci = src->vlan_tci;
498}
499
500/*
501 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
502 * @skb: skbuff to tag
503 *
504 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
505 *
506 * Following the skb_unshare() example, in case of error, the calling function
507 * doesn't have to worry about freeing the original skb.
508 */
509static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
510{
511 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
512 skb_vlan_tag_get(skb));
513 if (likely(skb))
514 __vlan_hwaccel_clear_tag(skb);
515 return skb;
516}
517
518/**
519 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
520 * @skb: skbuff to tag
521 * @vlan_proto: VLAN encapsulation protocol
522 * @vlan_tci: VLAN TCI to insert
523 *
524 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
525 */
526static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
527 __be16 vlan_proto, u16 vlan_tci)
528{
529 skb->vlan_proto = vlan_proto;
530 skb->vlan_tci = vlan_tci;
531 skb->vlan_present = 1;
532}
533
534/**
535 * __vlan_get_tag - get the VLAN ID that is part of the payload
536 * @skb: skbuff to query
537 * @vlan_tci: buffer to store value
538 *
539 * Returns error if the skb is not of VLAN type
540 */
541static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
542{
543 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
544
545 if (!eth_type_vlan(veth->h_vlan_proto))
546 return -EINVAL;
547
548 *vlan_tci = ntohs(veth->h_vlan_TCI);
549 return 0;
550}
551
552/**
553 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
554 * @skb: skbuff to query
555 * @vlan_tci: buffer to store value
556 *
557 * Returns error if @skb->vlan_tci is not set correctly
558 */
559static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
560 u16 *vlan_tci)
561{
562 if (skb_vlan_tag_present(skb)) {
563 *vlan_tci = skb_vlan_tag_get(skb);
564 return 0;
565 } else {
566 *vlan_tci = 0;
567 return -EINVAL;
568 }
569}
570
571/**
572 * vlan_get_tag - get the VLAN ID from the skb
573 * @skb: skbuff to query
574 * @vlan_tci: buffer to store value
575 *
576 * Returns error if the skb is not VLAN tagged
577 */
578static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
579{
580 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
581 return __vlan_hwaccel_get_tag(skb, vlan_tci);
582 } else {
583 return __vlan_get_tag(skb, vlan_tci);
584 }
585}
586
587/**
588 * vlan_get_protocol - get protocol EtherType.
589 * @skb: skbuff to query
590 * @type: first vlan protocol
591 * @depth: buffer to store length of eth and vlan tags in bytes
592 *
593 * Returns the EtherType of the packet, regardless of whether it is
594 * vlan encapsulated (normal or hardware accelerated) or not.
595 */
596static inline __be16 __vlan_get_protocol(struct sk_buff *skb, __be16 type,
597 int *depth)
598{
599 unsigned int vlan_depth = skb->mac_len;
600
601 /* if type is 802.1Q/AD then the header should already be
602 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
603 * ETH_HLEN otherwise
604 */
605 if (eth_type_vlan(type)) {
606 if (vlan_depth) {
607 if (WARN_ON(vlan_depth < VLAN_HLEN))
608 return 0;
609 vlan_depth -= VLAN_HLEN;
610 } else {
611 vlan_depth = ETH_HLEN;
612 }
613 do {
614 struct vlan_hdr *vh;
615
616 if (unlikely(!pskb_may_pull(skb,
617 vlan_depth + VLAN_HLEN)))
618 return 0;
619
620 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
621 type = vh->h_vlan_encapsulated_proto;
622 vlan_depth += VLAN_HLEN;
623 } while (eth_type_vlan(type));
624 }
625
626 if (depth)
627 *depth = vlan_depth;
628
629 return type;
630}
631
632/**
633 * vlan_get_protocol - get protocol EtherType.
634 * @skb: skbuff to query
635 *
636 * Returns the EtherType of the packet, regardless of whether it is
637 * vlan encapsulated (normal or hardware accelerated) or not.
638 */
639static inline __be16 vlan_get_protocol(struct sk_buff *skb)
640{
641 return __vlan_get_protocol(skb, skb->protocol, NULL);
642}
643
644static inline void vlan_set_encap_proto(struct sk_buff *skb,
645 struct vlan_hdr *vhdr)
646{
647 __be16 proto;
648 unsigned short *rawp;
649
650 /*
651 * Was a VLAN packet, grab the encapsulated protocol, which the layer
652 * three protocols care about.
653 */
654
655 proto = vhdr->h_vlan_encapsulated_proto;
656 if (eth_proto_is_802_3(proto)) {
657 skb->protocol = proto;
658 return;
659 }
660
661 rawp = (unsigned short *)(vhdr + 1);
662 if (*rawp == 0xFFFF)
663 /*
664 * This is a magic hack to spot IPX packets. Older Novell
665 * breaks the protocol design and runs IPX over 802.3 without
666 * an 802.2 LLC layer. We look for FFFF which isn't a used
667 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
668 * but does for the rest.
669 */
670 skb->protocol = htons(ETH_P_802_3);
671 else
672 /*
673 * Real 802.2 LLC
674 */
675 skb->protocol = htons(ETH_P_802_2);
676}
677
678/**
679 * skb_vlan_tagged - check if skb is vlan tagged.
680 * @skb: skbuff to query
681 *
682 * Returns true if the skb is tagged, regardless of whether it is hardware
683 * accelerated or not.
684 */
685static inline bool skb_vlan_tagged(const struct sk_buff *skb)
686{
687 if (!skb_vlan_tag_present(skb) &&
688 likely(!eth_type_vlan(skb->protocol)))
689 return false;
690
691 return true;
692}
693
694/**
695 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
696 * @skb: skbuff to query
697 *
698 * Returns true if the skb is tagged with multiple vlan headers, regardless
699 * of whether it is hardware accelerated or not.
700 */
701static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
702{
703 __be16 protocol = skb->protocol;
704
705 if (!skb_vlan_tag_present(skb)) {
706 struct vlan_ethhdr *veh;
707
708 if (likely(!eth_type_vlan(protocol)))
709 return false;
710
711 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
712 return false;
713
714 veh = (struct vlan_ethhdr *)skb->data;
715 protocol = veh->h_vlan_encapsulated_proto;
716 }
717
718 if (!eth_type_vlan(protocol))
719 return false;
720
721 return true;
722}
723
724/**
725 * vlan_features_check - drop unsafe features for skb with multiple tags.
726 * @skb: skbuff to query
727 * @features: features to be checked
728 *
729 * Returns features without unsafe ones if the skb has multiple tags.
730 */
731static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
732 netdev_features_t features)
733{
734 if (skb_vlan_tagged_multi(skb)) {
735 /* In the case of multi-tagged packets, use a direct mask
736 * instead of using netdev_interesect_features(), to make
737 * sure that only devices supporting NETIF_F_HW_CSUM will
738 * have checksum offloading support.
739 */
740 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
741 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
742 NETIF_F_HW_VLAN_STAG_TX;
743 }
744
745 return features;
746}
747
748/**
749 * compare_vlan_header - Compare two vlan headers
750 * @h1: Pointer to vlan header
751 * @h2: Pointer to vlan header
752 *
753 * Compare two vlan headers, returns 0 if equal.
754 *
755 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
756 */
757static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
758 const struct vlan_hdr *h2)
759{
760#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
761 return *(u32 *)h1 ^ *(u32 *)h2;
762#else
763 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
764 ((__force u32)h1->h_vlan_encapsulated_proto ^
765 (__force u32)h2->h_vlan_encapsulated_proto);
766#endif
767}
768#endif /* !(_LINUX_IF_VLAN_H_) */
769