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 */
69#define VLAN_TAG_PRESENT VLAN_CFI_MASK
70#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
71#define VLAN_N_VID 4096
72
73/* found in socket.c */
74extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
75
76static inline bool is_vlan_dev(const struct net_device *dev)
77{
78 return dev->priv_flags & IFF_802_1Q_VLAN;
79}
80
81#define skb_vlan_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
82#define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
83#define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK)
84#define skb_vlan_tag_get_prio(__skb) ((__skb)->vlan_tci & VLAN_PRIO_MASK)
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 struct net_device *vlan_dev_real_dev(const struct net_device *dev);
137extern u16 vlan_dev_vlan_id(const struct net_device *dev);
138extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
139
140/**
141 * struct vlan_priority_tci_mapping - vlan egress priority mappings
142 * @priority: skb priority
143 * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
144 * @next: pointer to next struct
145 */
146struct vlan_priority_tci_mapping {
147 u32 priority;
148 u16 vlan_qos;
149 struct vlan_priority_tci_mapping *next;
150};
151
152struct proc_dir_entry;
153struct netpoll;
154
155/**
156 * struct vlan_dev_priv - VLAN private device data
157 * @nr_ingress_mappings: number of ingress priority mappings
158 * @ingress_priority_map: ingress priority mappings
159 * @nr_egress_mappings: number of egress priority mappings
160 * @egress_priority_map: hash of egress priority mappings
161 * @vlan_proto: VLAN encapsulation protocol
162 * @vlan_id: VLAN identifier
163 * @flags: device flags
164 * @real_dev: underlying netdevice
165 * @real_dev_addr: address of underlying netdevice
166 * @dent: proc dir entry
167 * @vlan_pcpu_stats: ptr to percpu rx stats
168 */
169struct vlan_dev_priv {
170 unsigned int nr_ingress_mappings;
171 u32 ingress_priority_map[8];
172 unsigned int nr_egress_mappings;
173 struct vlan_priority_tci_mapping *egress_priority_map[16];
174
175 __be16 vlan_proto;
176 u16 vlan_id;
177 u16 flags;
178
179 struct net_device *real_dev;
180 unsigned char real_dev_addr[ETH_ALEN];
181
182 struct proc_dir_entry *dent;
183 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats;
184#ifdef CONFIG_NET_POLL_CONTROLLER
185 struct netpoll *netpoll;
186#endif
187 unsigned int nest_level;
188};
189
190static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
191{
192 return netdev_priv(dev);
193}
194
195static inline u16
196vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
197{
198 struct vlan_priority_tci_mapping *mp;
199
200 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
201
202 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
203 while (mp) {
204 if (mp->priority == skprio) {
205 return mp->vlan_qos; /* This should already be shifted
206 * to mask correctly with the
207 * VLAN's TCI */
208 }
209 mp = mp->next;
210 }
211 return 0;
212}
213
214extern bool vlan_do_receive(struct sk_buff **skb);
215
216extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
217extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
218
219extern int vlan_vids_add_by_dev(struct net_device *dev,
220 const struct net_device *by_dev);
221extern void vlan_vids_del_by_dev(struct net_device *dev,
222 const struct net_device *by_dev);
223
224extern bool vlan_uses_dev(const struct net_device *dev);
225
226static inline int vlan_get_encap_level(struct net_device *dev)
227{
228 BUG_ON(!is_vlan_dev(dev));
229 return vlan_dev_priv(dev)->nest_level;
230}
231#else
232static inline struct net_device *
233__vlan_find_dev_deep_rcu(struct net_device *real_dev,
234 __be16 vlan_proto, u16 vlan_id)
235{
236 return NULL;
237}
238
239static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
240{
241 BUG();
242 return NULL;
243}
244
245static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
246{
247 BUG();
248 return 0;
249}
250
251static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
252{
253 BUG();
254 return 0;
255}
256
257static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
258 u32 skprio)
259{
260 return 0;
261}
262
263static inline bool vlan_do_receive(struct sk_buff **skb)
264{
265 return false;
266}
267
268static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
269{
270 return 0;
271}
272
273static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
274{
275}
276
277static inline int vlan_vids_add_by_dev(struct net_device *dev,
278 const struct net_device *by_dev)
279{
280 return 0;
281}
282
283static inline void vlan_vids_del_by_dev(struct net_device *dev,
284 const struct net_device *by_dev)
285{
286}
287
288static inline bool vlan_uses_dev(const struct net_device *dev)
289{
290 return false;
291}
292static inline int vlan_get_encap_level(struct net_device *dev)
293{
294 BUG();
295 return 0;
296}
297#endif
298
299/**
300 * eth_type_vlan - check for valid vlan ether type.
301 * @ethertype: ether type to check
302 *
303 * Returns true if the ether type is a vlan ether type.
304 */
305static inline bool eth_type_vlan(__be16 ethertype)
306{
307 switch (ethertype) {
308 case htons(ETH_P_8021Q):
309 case htons(ETH_P_8021AD):
310 return true;
311 default:
312 return false;
313 }
314}
315
316static inline bool vlan_hw_offload_capable(netdev_features_t features,
317 __be16 proto)
318{
319 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
320 return true;
321 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
322 return true;
323 return false;
324}
325
326/**
327 * __vlan_insert_inner_tag - inner VLAN tag inserting
328 * @skb: skbuff to tag
329 * @vlan_proto: VLAN encapsulation protocol
330 * @vlan_tci: VLAN TCI to insert
331 * @mac_len: MAC header length including outer vlan headers
332 *
333 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
334 * Returns error if skb_cow_head fails.
335 *
336 * Does not change skb->protocol so this function can be used during receive.
337 */
338static inline int __vlan_insert_inner_tag(struct sk_buff *skb,
339 __be16 vlan_proto, u16 vlan_tci,
340 unsigned int mac_len)
341{
342 struct vlan_ethhdr *veth;
343
344 if (skb_cow_head(skb, VLAN_HLEN) < 0)
345 return -ENOMEM;
346
347 skb_push(skb, VLAN_HLEN);
348
349 /* Move the mac header sans proto to the beginning of the new header. */
350 if (likely(mac_len > ETH_TLEN))
351 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
352 skb->mac_header -= VLAN_HLEN;
353
354 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN);
355
356 /* first, the ethernet type */
357 if (likely(mac_len >= ETH_TLEN)) {
358 /* h_vlan_encapsulated_proto should already be populated, and
359 * skb->data has space for h_vlan_proto
360 */
361 veth->h_vlan_proto = vlan_proto;
362 } else {
363 /* h_vlan_encapsulated_proto should not be populated, and
364 * skb->data has no space for h_vlan_proto
365 */
366 veth->h_vlan_encapsulated_proto = skb->protocol;
367 }
368
369 /* now, the TCI */
370 veth->h_vlan_TCI = htons(vlan_tci);
371
372 return 0;
373}
374
375/**
376 * __vlan_insert_tag - regular VLAN tag inserting
377 * @skb: skbuff to tag
378 * @vlan_proto: VLAN encapsulation protocol
379 * @vlan_tci: VLAN TCI to insert
380 *
381 * Inserts the VLAN tag into @skb as part of the payload
382 * Returns error if skb_cow_head fails.
383 *
384 * Does not change skb->protocol so this function can be used during receive.
385 */
386static inline int __vlan_insert_tag(struct sk_buff *skb,
387 __be16 vlan_proto, u16 vlan_tci)
388{
389 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
390}
391
392/**
393 * vlan_insert_inner_tag - inner VLAN tag inserting
394 * @skb: skbuff to tag
395 * @vlan_proto: VLAN encapsulation protocol
396 * @vlan_tci: VLAN TCI to insert
397 * @mac_len: MAC header length including outer vlan headers
398 *
399 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
400 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
401 *
402 * Following the skb_unshare() example, in case of error, the calling function
403 * doesn't have to worry about freeing the original skb.
404 *
405 * Does not change skb->protocol so this function can be used during receive.
406 */
407static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb,
408 __be16 vlan_proto,
409 u16 vlan_tci,
410 unsigned int mac_len)
411{
412 int err;
413
414 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len);
415 if (err) {
416 dev_kfree_skb_any(skb);
417 return NULL;
418 }
419 return skb;
420}
421
422/**
423 * vlan_insert_tag - regular VLAN tag inserting
424 * @skb: skbuff to tag
425 * @vlan_proto: VLAN encapsulation protocol
426 * @vlan_tci: VLAN TCI to insert
427 *
428 * Inserts the VLAN tag into @skb as part of the payload
429 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
430 *
431 * Following the skb_unshare() example, in case of error, the calling function
432 * doesn't have to worry about freeing the original skb.
433 *
434 * Does not change skb->protocol so this function can be used during receive.
435 */
436static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
437 __be16 vlan_proto, u16 vlan_tci)
438{
439 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
440}
441
442/**
443 * vlan_insert_tag_set_proto - regular VLAN tag inserting
444 * @skb: skbuff to tag
445 * @vlan_proto: VLAN encapsulation protocol
446 * @vlan_tci: VLAN TCI to insert
447 *
448 * Inserts the VLAN tag into @skb as part of the payload
449 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
450 *
451 * Following the skb_unshare() example, in case of error, the calling function
452 * doesn't have to worry about freeing the original skb.
453 */
454static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
455 __be16 vlan_proto,
456 u16 vlan_tci)
457{
458 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
459 if (skb)
460 skb->protocol = vlan_proto;
461 return skb;
462}
463
464/*
465 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
466 * @skb: skbuff to tag
467 *
468 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
469 *
470 * Following the skb_unshare() example, in case of error, the calling function
471 * doesn't have to worry about freeing the original skb.
472 */
473static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
474{
475 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
476 skb_vlan_tag_get(skb));
477 if (likely(skb))
478 skb->vlan_tci = 0;
479 return skb;
480}
481
482/**
483 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
484 * @skb: skbuff to tag
485 * @vlan_proto: VLAN encapsulation protocol
486 * @vlan_tci: VLAN TCI to insert
487 *
488 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
489 */
490static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
491 __be16 vlan_proto, u16 vlan_tci)
492{
493 skb->vlan_proto = vlan_proto;
494 skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
495}
496
497/**
498 * __vlan_get_tag - get the VLAN ID that is part of the payload
499 * @skb: skbuff to query
500 * @vlan_tci: buffer to store value
501 *
502 * Returns error if the skb is not of VLAN type
503 */
504static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
505{
506 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
507
508 if (!eth_type_vlan(veth->h_vlan_proto))
509 return -EINVAL;
510
511 *vlan_tci = ntohs(veth->h_vlan_TCI);
512 return 0;
513}
514
515/**
516 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
517 * @skb: skbuff to query
518 * @vlan_tci: buffer to store value
519 *
520 * Returns error if @skb->vlan_tci is not set correctly
521 */
522static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
523 u16 *vlan_tci)
524{
525 if (skb_vlan_tag_present(skb)) {
526 *vlan_tci = skb_vlan_tag_get(skb);
527 return 0;
528 } else {
529 *vlan_tci = 0;
530 return -EINVAL;
531 }
532}
533
534#define HAVE_VLAN_GET_TAG
535
536/**
537 * vlan_get_tag - get the VLAN ID from the skb
538 * @skb: skbuff to query
539 * @vlan_tci: buffer to store value
540 *
541 * Returns error if the skb is not VLAN tagged
542 */
543static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
544{
545 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
546 return __vlan_hwaccel_get_tag(skb, vlan_tci);
547 } else {
548 return __vlan_get_tag(skb, vlan_tci);
549 }
550}
551
552/**
553 * vlan_get_protocol - get protocol EtherType.
554 * @skb: skbuff to query
555 * @type: first vlan protocol
556 * @depth: buffer to store length of eth and vlan tags in bytes
557 *
558 * Returns the EtherType of the packet, regardless of whether it is
559 * vlan encapsulated (normal or hardware accelerated) or not.
560 */
561static inline __be16 __vlan_get_protocol(struct sk_buff *skb, __be16 type,
562 int *depth)
563{
564 unsigned int vlan_depth = skb->mac_len;
565
566 /* if type is 802.1Q/AD then the header should already be
567 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
568 * ETH_HLEN otherwise
569 */
570 if (eth_type_vlan(type)) {
571 if (vlan_depth) {
572 if (WARN_ON(vlan_depth < VLAN_HLEN))
573 return 0;
574 vlan_depth -= VLAN_HLEN;
575 } else {
576 vlan_depth = ETH_HLEN;
577 }
578 do {
579 struct vlan_hdr *vh;
580
581 if (unlikely(!pskb_may_pull(skb,
582 vlan_depth + VLAN_HLEN)))
583 return 0;
584
585 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
586 type = vh->h_vlan_encapsulated_proto;
587 vlan_depth += VLAN_HLEN;
588 } while (eth_type_vlan(type));
589 }
590
591 if (depth)
592 *depth = vlan_depth;
593
594 return type;
595}
596
597/**
598 * vlan_get_protocol - get protocol EtherType.
599 * @skb: skbuff to query
600 *
601 * Returns the EtherType of the packet, regardless of whether it is
602 * vlan encapsulated (normal or hardware accelerated) or not.
603 */
604static inline __be16 vlan_get_protocol(struct sk_buff *skb)
605{
606 return __vlan_get_protocol(skb, skb->protocol, NULL);
607}
608
609static inline void vlan_set_encap_proto(struct sk_buff *skb,
610 struct vlan_hdr *vhdr)
611{
612 __be16 proto;
613 unsigned short *rawp;
614
615 /*
616 * Was a VLAN packet, grab the encapsulated protocol, which the layer
617 * three protocols care about.
618 */
619
620 proto = vhdr->h_vlan_encapsulated_proto;
621 if (eth_proto_is_802_3(proto)) {
622 skb->protocol = proto;
623 return;
624 }
625
626 rawp = (unsigned short *)(vhdr + 1);
627 if (*rawp == 0xFFFF)
628 /*
629 * This is a magic hack to spot IPX packets. Older Novell
630 * breaks the protocol design and runs IPX over 802.3 without
631 * an 802.2 LLC layer. We look for FFFF which isn't a used
632 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
633 * but does for the rest.
634 */
635 skb->protocol = htons(ETH_P_802_3);
636 else
637 /*
638 * Real 802.2 LLC
639 */
640 skb->protocol = htons(ETH_P_802_2);
641}
642
643/**
644 * skb_vlan_tagged - check if skb is vlan tagged.
645 * @skb: skbuff to query
646 *
647 * Returns true if the skb is tagged, regardless of whether it is hardware
648 * accelerated or not.
649 */
650static inline bool skb_vlan_tagged(const struct sk_buff *skb)
651{
652 if (!skb_vlan_tag_present(skb) &&
653 likely(!eth_type_vlan(skb->protocol)))
654 return false;
655
656 return true;
657}
658
659/**
660 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
661 * @skb: skbuff to query
662 *
663 * Returns true if the skb is tagged with multiple vlan headers, regardless
664 * of whether it is hardware accelerated or not.
665 */
666static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
667{
668 __be16 protocol = skb->protocol;
669
670 if (!skb_vlan_tag_present(skb)) {
671 struct vlan_ethhdr *veh;
672
673 if (likely(!eth_type_vlan(protocol)))
674 return false;
675
676 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
677 return false;
678
679 veh = (struct vlan_ethhdr *)skb->data;
680 protocol = veh->h_vlan_encapsulated_proto;
681 }
682
683 if (!eth_type_vlan(protocol))
684 return false;
685
686 return true;
687}
688
689/**
690 * vlan_features_check - drop unsafe features for skb with multiple tags.
691 * @skb: skbuff to query
692 * @features: features to be checked
693 *
694 * Returns features without unsafe ones if the skb has multiple tags.
695 */
696static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
697 netdev_features_t features)
698{
699 if (skb_vlan_tagged_multi(skb)) {
700 /* In the case of multi-tagged packets, use a direct mask
701 * instead of using netdev_interesect_features(), to make
702 * sure that only devices supporting NETIF_F_HW_CSUM will
703 * have checksum offloading support.
704 */
705 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
706 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
707 NETIF_F_HW_VLAN_STAG_TX;
708 }
709
710 return features;
711}
712
713/**
714 * compare_vlan_header - Compare two vlan headers
715 * @h1: Pointer to vlan header
716 * @h2: Pointer to vlan header
717 *
718 * Compare two vlan headers, returns 0 if equal.
719 *
720 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
721 */
722static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
723 const struct vlan_hdr *h2)
724{
725#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
726 return *(u32 *)h1 ^ *(u32 *)h2;
727#else
728 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
729 ((__force u32)h1->h_vlan_encapsulated_proto ^
730 (__force u32)h2->h_vlan_encapsulated_proto);
731#endif
732}
733#endif /* !(_LINUX_IF_VLAN_H_) */
734