1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * VLAN An implementation of 802.1Q VLAN tagging.
4 *
5 * Authors: Ben Greear <greearb@candelatech.com>
6 */
7#ifndef _LINUX_IF_VLAN_H_
8#define _LINUX_IF_VLAN_H_
9
10#include <linux/netdevice.h>
11#include <linux/etherdevice.h>
12#include <linux/rtnetlink.h>
13#include <linux/bug.h>
14#include <uapi/linux/if_vlan.h>
15
16#define VLAN_HLEN 4 /* The additional bytes required by VLAN
17 * (in addition to the Ethernet header)
18 */
19#define VLAN_ETH_HLEN 18 /* Total octets in header. */
20#define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
21
22/*
23 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
24 */
25#define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
26#define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
27
28#define VLAN_MAX_DEPTH 8 /* Max. number of nested VLAN tags parsed */
29
30/*
31 * struct vlan_hdr - vlan header
32 * @h_vlan_TCI: priority and VLAN ID
33 * @h_vlan_encapsulated_proto: packet type ID or len
34 */
35struct vlan_hdr {
36 __be16 h_vlan_TCI;
37 __be16 h_vlan_encapsulated_proto;
38};
39
40/**
41 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
42 * @h_dest: destination ethernet address
43 * @h_source: source ethernet address
44 * @h_vlan_proto: ethernet protocol
45 * @h_vlan_TCI: priority and VLAN ID
46 * @h_vlan_encapsulated_proto: packet type ID or len
47 */
48struct vlan_ethhdr {
49 struct_group(addrs,
50 unsigned char h_dest[ETH_ALEN];
51 unsigned char h_source[ETH_ALEN];
52 );
53 __be16 h_vlan_proto;
54 __be16 h_vlan_TCI;
55 __be16 h_vlan_encapsulated_proto;
56};
57
58#include <linux/skbuff.h>
59
60static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
61{
62 return (struct vlan_ethhdr *)skb_mac_header(skb);
63}
64
65/* Prefer this version in TX path, instead of
66 * skb_reset_mac_header() + vlan_eth_hdr()
67 */
68static inline struct vlan_ethhdr *skb_vlan_eth_hdr(const struct sk_buff *skb)
69{
70 return (struct vlan_ethhdr *)skb->data;
71}
72
73#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
74#define VLAN_PRIO_SHIFT 13
75#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator / Drop Eligible Indicator */
76#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
77#define VLAN_N_VID 4096
78
79/* found in socket.c */
80extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
81
82static inline bool is_vlan_dev(const struct net_device *dev)
83{
84 return dev->priv_flags & IFF_802_1Q_VLAN;
85}
86
87#define skb_vlan_tag_present(__skb) (!!(__skb)->vlan_all)
88#define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci)
89#define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK)
90#define skb_vlan_tag_get_cfi(__skb) (!!((__skb)->vlan_tci & VLAN_CFI_MASK))
91#define skb_vlan_tag_get_prio(__skb) (((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT)
92
93static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
94{
95 ASSERT_RTNL();
96 return notifier_to_errno(ret: call_netdevice_notifiers(val: NETDEV_CVLAN_FILTER_PUSH_INFO, dev));
97}
98
99static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev)
100{
101 ASSERT_RTNL();
102 call_netdevice_notifiers(val: NETDEV_CVLAN_FILTER_DROP_INFO, dev);
103}
104
105static inline int vlan_get_rx_stag_filter_info(struct net_device *dev)
106{
107 ASSERT_RTNL();
108 return notifier_to_errno(ret: call_netdevice_notifiers(val: NETDEV_SVLAN_FILTER_PUSH_INFO, dev));
109}
110
111static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev)
112{
113 ASSERT_RTNL();
114 call_netdevice_notifiers(val: NETDEV_SVLAN_FILTER_DROP_INFO, dev);
115}
116
117/**
118 * struct vlan_pcpu_stats - VLAN percpu rx/tx stats
119 * @rx_packets: number of received packets
120 * @rx_bytes: number of received bytes
121 * @rx_multicast: number of received multicast packets
122 * @tx_packets: number of transmitted packets
123 * @tx_bytes: number of transmitted bytes
124 * @syncp: synchronization point for 64bit counters
125 * @rx_errors: number of rx errors
126 * @tx_dropped: number of tx drops
127 */
128struct vlan_pcpu_stats {
129 u64_stats_t rx_packets;
130 u64_stats_t rx_bytes;
131 u64_stats_t rx_multicast;
132 u64_stats_t tx_packets;
133 u64_stats_t tx_bytes;
134 struct u64_stats_sync syncp;
135 u32 rx_errors;
136 u32 tx_dropped;
137};
138
139#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
140
141extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
142 __be16 vlan_proto, u16 vlan_id);
143extern int vlan_for_each(struct net_device *dev,
144 int (*action)(struct net_device *dev, int vid,
145 void *arg), void *arg);
146extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
147extern u16 vlan_dev_vlan_id(const struct net_device *dev);
148extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
149
150/**
151 * struct vlan_priority_tci_mapping - vlan egress priority mappings
152 * @priority: skb priority
153 * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
154 * @next: pointer to next struct
155 */
156struct vlan_priority_tci_mapping {
157 u32 priority;
158 u16 vlan_qos;
159 struct vlan_priority_tci_mapping *next;
160};
161
162struct proc_dir_entry;
163struct netpoll;
164
165/**
166 * struct vlan_dev_priv - VLAN private device data
167 * @nr_ingress_mappings: number of ingress priority mappings
168 * @ingress_priority_map: ingress priority mappings
169 * @nr_egress_mappings: number of egress priority mappings
170 * @egress_priority_map: hash of egress priority mappings
171 * @vlan_proto: VLAN encapsulation protocol
172 * @vlan_id: VLAN identifier
173 * @flags: device flags
174 * @real_dev: underlying netdevice
175 * @dev_tracker: refcount tracker for @real_dev reference
176 * @real_dev_addr: address of underlying netdevice
177 * @dent: proc dir entry
178 * @vlan_pcpu_stats: ptr to percpu rx stats
179 * @netpoll: netpoll instance "propagated" down to @real_dev
180 */
181struct vlan_dev_priv {
182 unsigned int nr_ingress_mappings;
183 u32 ingress_priority_map[8];
184 unsigned int nr_egress_mappings;
185 struct vlan_priority_tci_mapping *egress_priority_map[16];
186
187 __be16 vlan_proto;
188 u16 vlan_id;
189 u16 flags;
190
191 struct net_device *real_dev;
192 netdevice_tracker dev_tracker;
193
194 unsigned char real_dev_addr[ETH_ALEN];
195
196 struct proc_dir_entry *dent;
197 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats;
198#ifdef CONFIG_NET_POLL_CONTROLLER
199 struct netpoll *netpoll;
200#endif
201};
202
203static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
204{
205 return netdev_priv(dev);
206}
207
208static inline u16
209vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
210{
211 struct vlan_priority_tci_mapping *mp;
212
213 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
214
215 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
216 while (mp) {
217 if (mp->priority == skprio) {
218 return mp->vlan_qos; /* This should already be shifted
219 * to mask correctly with the
220 * VLAN's TCI */
221 }
222 mp = mp->next;
223 }
224 return 0;
225}
226
227extern bool vlan_do_receive(struct sk_buff **skb);
228
229extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
230extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
231
232extern int vlan_vids_add_by_dev(struct net_device *dev,
233 const struct net_device *by_dev);
234extern void vlan_vids_del_by_dev(struct net_device *dev,
235 const struct net_device *by_dev);
236
237extern bool vlan_uses_dev(const struct net_device *dev);
238
239#else
240static inline struct net_device *
241__vlan_find_dev_deep_rcu(struct net_device *real_dev,
242 __be16 vlan_proto, u16 vlan_id)
243{
244 return NULL;
245}
246
247static inline int
248vlan_for_each(struct net_device *dev,
249 int (*action)(struct net_device *dev, int vid, void *arg),
250 void *arg)
251{
252 return 0;
253}
254
255static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
256{
257 BUG();
258 return NULL;
259}
260
261static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
262{
263 BUG();
264 return 0;
265}
266
267static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
268{
269 BUG();
270 return 0;
271}
272
273static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
274 u32 skprio)
275{
276 return 0;
277}
278
279static inline bool vlan_do_receive(struct sk_buff **skb)
280{
281 return false;
282}
283
284static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
285{
286 return 0;
287}
288
289static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
290{
291}
292
293static inline int vlan_vids_add_by_dev(struct net_device *dev,
294 const struct net_device *by_dev)
295{
296 return 0;
297}
298
299static inline void vlan_vids_del_by_dev(struct net_device *dev,
300 const struct net_device *by_dev)
301{
302}
303
304static inline bool vlan_uses_dev(const struct net_device *dev)
305{
306 return false;
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 * Does not change skb->protocol so this function can be used during receive.
346 *
347 * Returns: error if skb_cow_head fails.
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 if (skb_mac_header_was_set(skb))
364 skb->mac_header -= VLAN_HLEN;
365
366 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN);
367
368 /* first, the ethernet type */
369 if (likely(mac_len >= ETH_TLEN)) {
370 /* h_vlan_encapsulated_proto should already be populated, and
371 * skb->data has space for h_vlan_proto
372 */
373 veth->h_vlan_proto = vlan_proto;
374 } else {
375 /* h_vlan_encapsulated_proto should not be populated, and
376 * skb->data has no space for h_vlan_proto
377 */
378 veth->h_vlan_encapsulated_proto = skb->protocol;
379 }
380
381 /* now, the TCI */
382 veth->h_vlan_TCI = htons(vlan_tci);
383
384 return 0;
385}
386
387/**
388 * __vlan_insert_tag - regular VLAN tag inserting
389 * @skb: skbuff to tag
390 * @vlan_proto: VLAN encapsulation protocol
391 * @vlan_tci: VLAN TCI to insert
392 *
393 * Inserts the VLAN tag into @skb as part of the payload
394 * Does not change skb->protocol so this function can be used during receive.
395 *
396 * Returns: error if skb_cow_head fails.
397 */
398static inline int __vlan_insert_tag(struct sk_buff *skb,
399 __be16 vlan_proto, u16 vlan_tci)
400{
401 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
402}
403
404/**
405 * vlan_insert_inner_tag - inner VLAN tag inserting
406 * @skb: skbuff to tag
407 * @vlan_proto: VLAN encapsulation protocol
408 * @vlan_tci: VLAN TCI to insert
409 * @mac_len: MAC header length including outer vlan headers
410 *
411 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
412 * Returns a VLAN tagged skb. This might change skb->head.
413 *
414 * Following the skb_unshare() example, in case of error, the calling function
415 * doesn't have to worry about freeing the original skb.
416 *
417 * Does not change skb->protocol so this function can be used during receive.
418 *
419 * Return: modified @skb on success, NULL on error (@skb is freed).
420 */
421static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb,
422 __be16 vlan_proto,
423 u16 vlan_tci,
424 unsigned int mac_len)
425{
426 int err;
427
428 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len);
429 if (err) {
430 dev_kfree_skb_any(skb);
431 return NULL;
432 }
433 return skb;
434}
435
436/**
437 * vlan_insert_tag - regular VLAN tag inserting
438 * @skb: skbuff to tag
439 * @vlan_proto: VLAN encapsulation protocol
440 * @vlan_tci: VLAN TCI to insert
441 *
442 * Inserts the VLAN tag into @skb as part of the payload
443 * Returns a VLAN tagged skb. This might change skb->head.
444 *
445 * Following the skb_unshare() example, in case of error, the calling function
446 * doesn't have to worry about freeing the original skb.
447 *
448 * Does not change skb->protocol so this function can be used during receive.
449 *
450 * Return: modified @skb on success, NULL on error (@skb is freed).
451 */
452static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
453 __be16 vlan_proto, u16 vlan_tci)
454{
455 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
456}
457
458/**
459 * vlan_insert_tag_set_proto - regular VLAN tag inserting
460 * @skb: skbuff to tag
461 * @vlan_proto: VLAN encapsulation protocol
462 * @vlan_tci: VLAN TCI to insert
463 *
464 * Inserts the VLAN tag into @skb as part of the payload
465 * Returns a VLAN tagged skb. This might change skb->head.
466 *
467 * Following the skb_unshare() example, in case of error, the calling function
468 * doesn't have to worry about freeing the original skb.
469 *
470 * Return: modified @skb on success, NULL on error (@skb is freed).
471 */
472static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
473 __be16 vlan_proto,
474 u16 vlan_tci)
475{
476 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
477 if (skb)
478 skb->protocol = vlan_proto;
479 return skb;
480}
481
482/**
483 * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info
484 * @skb: skbuff to clear
485 *
486 * Clears the VLAN information from @skb
487 */
488static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
489{
490 skb->vlan_all = 0;
491}
492
493/**
494 * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb
495 * @dst: skbuff to copy to
496 * @src: skbuff to copy from
497 *
498 * Copies VLAN information from @src to @dst (for branchless code)
499 */
500static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src)
501{
502 dst->vlan_all = src->vlan_all;
503}
504
505/*
506 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
507 * @skb: skbuff to tag
508 *
509 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
510 *
511 * Following the skb_unshare() example, in case of error, the calling function
512 * doesn't have to worry about freeing the original skb.
513 */
514static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
515{
516 skb = vlan_insert_tag_set_proto(skb, vlan_proto: skb->vlan_proto,
517 skb_vlan_tag_get(skb));
518 if (likely(skb))
519 __vlan_hwaccel_clear_tag(skb);
520 return skb;
521}
522
523/**
524 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
525 * @skb: skbuff to tag
526 * @vlan_proto: VLAN encapsulation protocol
527 * @vlan_tci: VLAN TCI to insert
528 *
529 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
530 */
531static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
532 __be16 vlan_proto, u16 vlan_tci)
533{
534 skb->vlan_proto = vlan_proto;
535 skb->vlan_tci = vlan_tci;
536}
537
538/**
539 * __vlan_get_tag - get the VLAN ID that is part of the payload
540 * @skb: skbuff to query
541 * @vlan_tci: buffer to store value
542 *
543 * Returns: error if the skb is not of VLAN type
544 */
545static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
546{
547 struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb);
548
549 if (!eth_type_vlan(ethertype: veth->h_vlan_proto))
550 return -ENODATA;
551
552 *vlan_tci = ntohs(veth->h_vlan_TCI);
553 return 0;
554}
555
556/**
557 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
558 * @skb: skbuff to query
559 * @vlan_tci: buffer to store value
560 *
561 * Returns: error if @skb->vlan_tci is not set correctly
562 */
563static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
564 u16 *vlan_tci)
565{
566 if (skb_vlan_tag_present(skb)) {
567 *vlan_tci = skb_vlan_tag_get(skb);
568 return 0;
569 } else {
570 *vlan_tci = 0;
571 return -ENODATA;
572 }
573}
574
575/**
576 * vlan_get_tag - get the VLAN ID from the skb
577 * @skb: skbuff to query
578 * @vlan_tci: buffer to store value
579 *
580 * Returns: error if the skb is not VLAN tagged
581 */
582static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
583{
584 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
585 return __vlan_hwaccel_get_tag(skb, vlan_tci);
586 } else {
587 return __vlan_get_tag(skb, vlan_tci);
588 }
589}
590
591/**
592 * __vlan_get_protocol_offset() - get protocol EtherType.
593 * @skb: skbuff to query
594 * @type: first vlan protocol
595 * @mac_offset: MAC offset
596 * @depth: buffer to store length of eth and vlan tags in bytes
597 *
598 * Returns: the EtherType of the packet, regardless of whether it is
599 * vlan encapsulated (normal or hardware accelerated) or not.
600 */
601static inline __be16 __vlan_get_protocol_offset(const struct sk_buff *skb,
602 __be16 type,
603 int mac_offset,
604 int *depth)
605{
606 unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH;
607
608 /* if type is 802.1Q/AD then the header should already be
609 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
610 * ETH_HLEN otherwise
611 */
612 if (eth_type_vlan(ethertype: type)) {
613 if (vlan_depth) {
614 if (WARN_ON(vlan_depth < VLAN_HLEN))
615 return 0;
616 vlan_depth -= VLAN_HLEN;
617 } else {
618 vlan_depth = ETH_HLEN;
619 }
620 do {
621 struct vlan_hdr vhdr, *vh;
622
623 vh = skb_header_pointer(skb, offset: mac_offset + vlan_depth,
624 len: sizeof(vhdr), buffer: &vhdr);
625 if (unlikely(!vh || !--parse_depth))
626 return 0;
627
628 type = vh->h_vlan_encapsulated_proto;
629 vlan_depth += VLAN_HLEN;
630 } while (eth_type_vlan(ethertype: type));
631 }
632
633 if (depth)
634 *depth = vlan_depth;
635
636 return type;
637}
638
639static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type,
640 int *depth)
641{
642 return __vlan_get_protocol_offset(skb, type, mac_offset: 0, depth);
643}
644
645/**
646 * vlan_get_protocol - get protocol EtherType.
647 * @skb: skbuff to query
648 *
649 * Returns: the EtherType of the packet, regardless of whether it is
650 * vlan encapsulated (normal or hardware accelerated) or not.
651 */
652static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
653{
654 return __vlan_get_protocol(skb, type: skb->protocol, NULL);
655}
656
657/* This version of __vlan_get_protocol() also pulls mac header in skb->head */
658static inline __be16 vlan_get_protocol_and_depth(struct sk_buff *skb,
659 __be16 type, int *depth)
660{
661 int maclen;
662
663 type = __vlan_get_protocol(skb, type, depth: &maclen);
664
665 if (type) {
666 if (!pskb_may_pull(skb, len: maclen))
667 type = 0;
668 else if (depth)
669 *depth = maclen;
670 }
671 return type;
672}
673
674/* A getter for the SKB protocol field which will handle VLAN tags consistently
675 * whether VLAN acceleration is enabled or not.
676 */
677static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan)
678{
679 if (!skip_vlan)
680 /* VLAN acceleration strips the VLAN header from the skb and
681 * moves it to skb->vlan_proto
682 */
683 return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol;
684
685 return vlan_get_protocol(skb);
686}
687
688static inline void vlan_set_encap_proto(struct sk_buff *skb,
689 struct vlan_hdr *vhdr)
690{
691 __be16 proto;
692 unsigned short *rawp;
693
694 /*
695 * Was a VLAN packet, grab the encapsulated protocol, which the layer
696 * three protocols care about.
697 */
698
699 proto = vhdr->h_vlan_encapsulated_proto;
700 if (eth_proto_is_802_3(proto)) {
701 skb->protocol = proto;
702 return;
703 }
704
705 rawp = (unsigned short *)(vhdr + 1);
706 if (*rawp == 0xFFFF)
707 /*
708 * This is a magic hack to spot IPX packets. Older Novell
709 * breaks the protocol design and runs IPX over 802.3 without
710 * an 802.2 LLC layer. We look for FFFF which isn't a used
711 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
712 * but does for the rest.
713 */
714 skb->protocol = htons(ETH_P_802_3);
715 else
716 /*
717 * Real 802.2 LLC
718 */
719 skb->protocol = htons(ETH_P_802_2);
720}
721
722/**
723 * vlan_remove_tag - remove outer VLAN tag from payload
724 * @skb: skbuff to remove tag from
725 * @vlan_tci: buffer to store value
726 *
727 * Expects the skb to contain a VLAN tag in the payload, and to have skb->data
728 * pointing at the MAC header.
729 *
730 * Returns: a new pointer to skb->data, or NULL on failure to pull.
731 */
732static inline void *vlan_remove_tag(struct sk_buff *skb, u16 *vlan_tci)
733{
734 struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
735
736 *vlan_tci = ntohs(vhdr->h_vlan_TCI);
737
738 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
739 vlan_set_encap_proto(skb, vhdr);
740 return __skb_pull(skb, VLAN_HLEN);
741}
742
743/**
744 * skb_vlan_tagged - check if skb is vlan tagged.
745 * @skb: skbuff to query
746 *
747 * Returns: true if the skb is tagged, regardless of whether it is hardware
748 * accelerated or not.
749 */
750static inline bool skb_vlan_tagged(const struct sk_buff *skb)
751{
752 if (!skb_vlan_tag_present(skb) &&
753 likely(!eth_type_vlan(skb->protocol)))
754 return false;
755
756 return true;
757}
758
759/**
760 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
761 * @skb: skbuff to query
762 *
763 * Returns: true if the skb is tagged with multiple vlan headers, regardless
764 * of whether it is hardware accelerated or not.
765 */
766static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
767{
768 __be16 protocol = skb->protocol;
769
770 if (!skb_vlan_tag_present(skb)) {
771 struct vlan_ethhdr *veh;
772
773 if (likely(!eth_type_vlan(protocol)))
774 return false;
775
776 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
777 return false;
778
779 veh = skb_vlan_eth_hdr(skb);
780 protocol = veh->h_vlan_encapsulated_proto;
781 }
782
783 if (!eth_type_vlan(ethertype: protocol))
784 return false;
785
786 return true;
787}
788
789/**
790 * vlan_features_check - drop unsafe features for skb with multiple tags.
791 * @skb: skbuff to query
792 * @features: features to be checked
793 *
794 * Returns: features without unsafe ones if the skb has multiple tags.
795 */
796static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
797 netdev_features_t features)
798{
799 if (skb_vlan_tagged_multi(skb)) {
800 /* In the case of multi-tagged packets, use a direct mask
801 * instead of using netdev_interesect_features(), to make
802 * sure that only devices supporting NETIF_F_HW_CSUM will
803 * have checksum offloading support.
804 */
805 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
806 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
807 NETIF_F_HW_VLAN_STAG_TX;
808 }
809
810 return features;
811}
812
813/**
814 * compare_vlan_header - Compare two vlan headers
815 * @h1: Pointer to vlan header
816 * @h2: Pointer to vlan header
817 *
818 * Compare two vlan headers.
819 *
820 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
821 *
822 * Return: 0 if equal, arbitrary non-zero value if not equal.
823 */
824static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
825 const struct vlan_hdr *h2)
826{
827#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
828 return *(u32 *)h1 ^ *(u32 *)h2;
829#else
830 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
831 ((__force u32)h1->h_vlan_encapsulated_proto ^
832 (__force u32)h2->h_vlan_encapsulated_proto);
833#endif
834}
835#endif /* !(_LINUX_IF_VLAN_H_) */
836

source code of linux/include/linux/if_vlan.h

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