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 */
35 struct 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 */
48 struct 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
60 static 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 */
68 static 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 */
80 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
81
82 static 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
93 static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
94 {
95 ASSERT_RTNL();
96 return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev));
97 }
98
99 static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev)
100 {
101 ASSERT_RTNL();
102 call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev);
103 }
104
105 static inline int vlan_get_rx_stag_filter_info(struct net_device *dev)
106 {
107 ASSERT_RTNL();
108 return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev));
109 }
110
111 static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev)
112 {
113 ASSERT_RTNL();
114 call_netdevice_notifiers(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 */
128 struct 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
141 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
142 __be16 vlan_proto, u16 vlan_id);
143 extern int vlan_for_each(struct net_device *dev,
144 int (*action)(struct net_device *dev, int vid,
145 void *arg), void *arg);
146 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
147 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
148 extern __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 */
156 struct vlan_priority_tci_mapping {
157 u32 priority;
158 u16 vlan_qos;
159 struct vlan_priority_tci_mapping *next;
160 };
161
162 struct proc_dir_entry;
163 struct 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 */
180 struct vlan_dev_priv {
181 unsigned int nr_ingress_mappings;
182 u32 ingress_priority_map[8];
183 unsigned int nr_egress_mappings;
184 struct vlan_priority_tci_mapping *egress_priority_map[16];
185
186 __be16 vlan_proto;
187 u16 vlan_id;
188 u16 flags;
189
190 struct net_device *real_dev;
191 netdevice_tracker dev_tracker;
192
193 unsigned char real_dev_addr[ETH_ALEN];
194
195 struct proc_dir_entry *dent;
196 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats;
197 #ifdef CONFIG_NET_POLL_CONTROLLER
198 struct netpoll *netpoll;
199 #endif
200 };
201
202 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
203 {
204 return netdev_priv(dev);
205 }
206
207 static inline u16
208 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
209 {
210 struct vlan_priority_tci_mapping *mp;
211
212 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
213
214 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
215 while (mp) {
216 if (mp->priority == skprio) {
217 return mp->vlan_qos; /* This should already be shifted
218 * to mask correctly with the
219 * VLAN's TCI */
220 }
221 mp = mp->next;
222 }
223 return 0;
224 }
225
226 extern bool vlan_do_receive(struct sk_buff **skb);
227
228 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
229 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
230
231 extern int vlan_vids_add_by_dev(struct net_device *dev,
232 const struct net_device *by_dev);
233 extern void vlan_vids_del_by_dev(struct net_device *dev,
234 const struct net_device *by_dev);
235
236 extern bool vlan_uses_dev(const struct net_device *dev);
237
238 #else
239 static inline struct net_device *
240 __vlan_find_dev_deep_rcu(struct net_device *real_dev,
241 __be16 vlan_proto, u16 vlan_id)
242 {
243 return NULL;
244 }
245
246 static inline int
247 vlan_for_each(struct net_device *dev,
248 int (*action)(struct net_device *dev, int vid, void *arg),
249 void *arg)
250 {
251 return 0;
252 }
253
254 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
255 {
256 BUG();
257 return NULL;
258 }
259
260 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
261 {
262 BUG();
263 return 0;
264 }
265
266 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
267 {
268 BUG();
269 return 0;
270 }
271
272 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
273 u32 skprio)
274 {
275 return 0;
276 }
277
278 static inline bool vlan_do_receive(struct sk_buff **skb)
279 {
280 return false;
281 }
282
283 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
284 {
285 return 0;
286 }
287
288 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
289 {
290 }
291
292 static inline int vlan_vids_add_by_dev(struct net_device *dev,
293 const struct net_device *by_dev)
294 {
295 return 0;
296 }
297
298 static inline void vlan_vids_del_by_dev(struct net_device *dev,
299 const struct net_device *by_dev)
300 {
301 }
302
303 static inline bool vlan_uses_dev(const struct net_device *dev)
304 {
305 return false;
306 }
307 #endif
308
309 /**
310 * eth_type_vlan - check for valid vlan ether type.
311 * @ethertype: ether type to check
312 *
313 * Returns true if the ether type is a vlan ether type.
314 */
315 static inline bool eth_type_vlan(__be16 ethertype)
316 {
317 switch (ethertype) {
318 case htons(ETH_P_8021Q):
319 case htons(ETH_P_8021AD):
320 return true;
321 default:
322 return false;
323 }
324 }
325
326 static inline bool vlan_hw_offload_capable(netdev_features_t features,
327 __be16 proto)
328 {
329 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
330 return true;
331 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
332 return true;
333 return false;
334 }
335
336 /**
337 * __vlan_insert_inner_tag - inner VLAN tag inserting
338 * @skb: skbuff to tag
339 * @vlan_proto: VLAN encapsulation protocol
340 * @vlan_tci: VLAN TCI to insert
341 * @mac_len: MAC header length including outer vlan headers
342 *
343 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
344 * Returns error if skb_cow_head fails.
345 *
346 * Does not change skb->protocol so this function can be used during receive.
347 */
348 static inline int __vlan_insert_inner_tag(struct sk_buff *skb,
349 __be16 vlan_proto, u16 vlan_tci,
350 unsigned int mac_len)
351 {
352 struct vlan_ethhdr *veth;
353
354 if (skb_cow_head(skb, VLAN_HLEN) < 0)
355 return -ENOMEM;
356
357 skb_push(skb, VLAN_HLEN);
358
359 /* Move the mac header sans proto to the beginning of the new header. */
360 if (likely(mac_len > ETH_TLEN))
361 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
362 if (skb_mac_header_was_set(skb))
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 */
397 static 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. This might change skb->head.
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 */
418 static 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. This might change skb->head.
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 */
447 static 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. This might change skb->head.
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 */
465 static 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 */
481 static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
482 {
483 skb->vlan_all = 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 */
493 static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src)
494 {
495 dst->vlan_all = src->vlan_all;
496 }
497
498 /*
499 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
500 * @skb: skbuff to tag
501 *
502 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
503 *
504 * Following the skb_unshare() example, in case of error, the calling function
505 * doesn't have to worry about freeing the original skb.
506 */
507 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
508 {
509 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
510 skb_vlan_tag_get(skb));
511 if (likely(skb))
512 __vlan_hwaccel_clear_tag(skb);
513 return skb;
514 }
515
516 /**
517 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
518 * @skb: skbuff to tag
519 * @vlan_proto: VLAN encapsulation protocol
520 * @vlan_tci: VLAN TCI to insert
521 *
522 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
523 */
524 static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
525 __be16 vlan_proto, u16 vlan_tci)
526 {
527 skb->vlan_proto = vlan_proto;
528 skb->vlan_tci = vlan_tci;
529 }
530
531 /**
532 * __vlan_get_tag - get the VLAN ID that is part of the payload
533 * @skb: skbuff to query
534 * @vlan_tci: buffer to store value
535 *
536 * Returns error if the skb is not of VLAN type
537 */
538 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
539 {
540 struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb);
541
542 if (!eth_type_vlan(veth->h_vlan_proto))
543 return -ENODATA;
544
545 *vlan_tci = ntohs(veth->h_vlan_TCI);
546 return 0;
547 }
548
549 /**
550 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
551 * @skb: skbuff to query
552 * @vlan_tci: buffer to store value
553 *
554 * Returns error if @skb->vlan_tci is not set correctly
555 */
556 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
557 u16 *vlan_tci)
558 {
559 if (skb_vlan_tag_present(skb)) {
560 *vlan_tci = skb_vlan_tag_get(skb);
561 return 0;
562 } else {
563 *vlan_tci = 0;
564 return -ENODATA;
565 }
566 }
567
568 /**
569 * vlan_get_tag - get the VLAN ID from the skb
570 * @skb: skbuff to query
571 * @vlan_tci: buffer to store value
572 *
573 * Returns error if the skb is not VLAN tagged
574 */
575 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
576 {
577 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
578 return __vlan_hwaccel_get_tag(skb, vlan_tci);
579 } else {
580 return __vlan_get_tag(skb, vlan_tci);
581 }
582 }
583
584 /**
585 * vlan_get_protocol - get protocol EtherType.
586 * @skb: skbuff to query
587 * @type: first vlan protocol
588 * @depth: buffer to store length of eth and vlan tags in bytes
589 *
590 * Returns the EtherType of the packet, regardless of whether it is
591 * vlan encapsulated (normal or hardware accelerated) or not.
592 */
593 static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type,
594 int *depth)
595 {
596 unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH;
597
598 /* if type is 802.1Q/AD then the header should already be
599 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
600 * ETH_HLEN otherwise
601 */
602 if (eth_type_vlan(type)) {
603 if (vlan_depth) {
604 if (WARN_ON(vlan_depth < VLAN_HLEN))
605 return 0;
606 vlan_depth -= VLAN_HLEN;
607 } else {
608 vlan_depth = ETH_HLEN;
609 }
610 do {
611 struct vlan_hdr vhdr, *vh;
612
613 vh = skb_header_pointer(skb, vlan_depth, sizeof(vhdr), &vhdr);
614 if (unlikely(!vh || !--parse_depth))
615 return 0;
616
617 type = vh->h_vlan_encapsulated_proto;
618 vlan_depth += VLAN_HLEN;
619 } while (eth_type_vlan(type));
620 }
621
622 if (depth)
623 *depth = vlan_depth;
624
625 return type;
626 }
627
628 /**
629 * vlan_get_protocol - get protocol EtherType.
630 * @skb: skbuff to query
631 *
632 * Returns the EtherType of the packet, regardless of whether it is
633 * vlan encapsulated (normal or hardware accelerated) or not.
634 */
635 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
636 {
637 return __vlan_get_protocol(skb, skb->protocol, NULL);
638 }
639
640 /* This version of __vlan_get_protocol() also pulls mac header in skb->head */
641 static inline __be16 vlan_get_protocol_and_depth(struct sk_buff *skb,
642 __be16 type, int *depth)
643 {
644 int maclen;
645
646 type = __vlan_get_protocol(skb, type, &maclen);
647
648 if (type) {
649 if (!pskb_may_pull(skb, maclen))
650 type = 0;
651 else if (depth)
652 *depth = maclen;
653 }
654 return type;
655 }
656
657 /* A getter for the SKB protocol field which will handle VLAN tags consistently
658 * whether VLAN acceleration is enabled or not.
659 */
660 static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan)
661 {
662 if (!skip_vlan)
663 /* VLAN acceleration strips the VLAN header from the skb and
664 * moves it to skb->vlan_proto
665 */
666 return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol;
667
668 return vlan_get_protocol(skb);
669 }
670
671 static inline void vlan_set_encap_proto(struct sk_buff *skb,
672 struct vlan_hdr *vhdr)
673 {
674 __be16 proto;
675 unsigned short *rawp;
676
677 /*
678 * Was a VLAN packet, grab the encapsulated protocol, which the layer
679 * three protocols care about.
680 */
681
682 proto = vhdr->h_vlan_encapsulated_proto;
683 if (eth_proto_is_802_3(proto)) {
684 skb->protocol = proto;
685 return;
686 }
687
688 rawp = (unsigned short *)(vhdr + 1);
689 if (*rawp == 0xFFFF)
690 /*
691 * This is a magic hack to spot IPX packets. Older Novell
692 * breaks the protocol design and runs IPX over 802.3 without
693 * an 802.2 LLC layer. We look for FFFF which isn't a used
694 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
695 * but does for the rest.
696 */
697 skb->protocol = htons(ETH_P_802_3);
698 else
699 /*
700 * Real 802.2 LLC
701 */
702 skb->protocol = htons(ETH_P_802_2);
703 }
704
705 /**
706 * vlan_remove_tag - remove outer VLAN tag from payload
707 * @skb: skbuff to remove tag from
708 * @vlan_tci: buffer to store value
709 *
710 * Expects the skb to contain a VLAN tag in the payload, and to have skb->data
711 * pointing at the MAC header.
712 *
713 * Returns a new pointer to skb->data, or NULL on failure to pull.
714 */
715 static inline void *vlan_remove_tag(struct sk_buff *skb, u16 *vlan_tci)
716 {
717 struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
718
719 *vlan_tci = ntohs(vhdr->h_vlan_TCI);
720
721 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
722 vlan_set_encap_proto(skb, vhdr);
723 return __skb_pull(skb, VLAN_HLEN);
724 }
725
726 /**
727 * skb_vlan_tagged - check if skb is vlan tagged.
728 * @skb: skbuff to query
729 *
730 * Returns true if the skb is tagged, regardless of whether it is hardware
731 * accelerated or not.
732 */
733 static inline bool skb_vlan_tagged(const struct sk_buff *skb)
734 {
735 if (!skb_vlan_tag_present(skb) &&
736 likely(!eth_type_vlan(skb->protocol)))
737 return false;
738
739 return true;
740 }
741
742 /**
743 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
744 * @skb: skbuff to query
745 *
746 * Returns true if the skb is tagged with multiple vlan headers, regardless
747 * of whether it is hardware accelerated or not.
748 */
749 static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
750 {
751 __be16 protocol = skb->protocol;
752
753 if (!skb_vlan_tag_present(skb)) {
754 struct vlan_ethhdr *veh;
755
756 if (likely(!eth_type_vlan(protocol)))
757 return false;
758
759 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
760 return false;
761
762 veh = skb_vlan_eth_hdr(skb);
763 protocol = veh->h_vlan_encapsulated_proto;
764 }
765
766 if (!eth_type_vlan(protocol))
767 return false;
768
769 return true;
770 }
771
772 /**
773 * vlan_features_check - drop unsafe features for skb with multiple tags.
774 * @skb: skbuff to query
775 * @features: features to be checked
776 *
777 * Returns features without unsafe ones if the skb has multiple tags.
778 */
779 static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
780 netdev_features_t features)
781 {
782 if (skb_vlan_tagged_multi(skb)) {
783 /* In the case of multi-tagged packets, use a direct mask
784 * instead of using netdev_interesect_features(), to make
785 * sure that only devices supporting NETIF_F_HW_CSUM will
786 * have checksum offloading support.
787 */
788 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
789 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
790 NETIF_F_HW_VLAN_STAG_TX;
791 }
792
793 return features;
794 }
795
796 /**
797 * compare_vlan_header - Compare two vlan headers
798 * @h1: Pointer to vlan header
799 * @h2: Pointer to vlan header
800 *
801 * Compare two vlan headers, returns 0 if equal.
802 *
803 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
804 */
805 static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
806 const struct vlan_hdr *h2)
807 {
808 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
809 return *(u32 *)h1 ^ *(u32 *)h2;
810 #else
811 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
812 ((__force u32)h1->h_vlan_encapsulated_proto ^
813 (__force u32)h2->h_vlan_encapsulated_proto);
814 #endif
815 }
816 #endif /* !(_LINUX_IF_VLAN_H_) */
817
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