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
vlan_eth_hdr(const struct sk_buff * skb)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 #define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
66 #define VLAN_PRIO_SHIFT 13
67 #define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator / Drop Eligible Indicator */
68 #define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
69 #define VLAN_N_VID 4096
70
71 /* found in socket.c */
72 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
73
is_vlan_dev(const struct net_device * dev)74 static inline bool is_vlan_dev(const struct net_device *dev)
75 {
76 return dev->priv_flags & IFF_802_1Q_VLAN;
77 }
78
79 #define skb_vlan_tag_present(__skb) (!!(__skb)->vlan_all)
80 #define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci)
81 #define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK)
82 #define skb_vlan_tag_get_cfi(__skb) (!!((__skb)->vlan_tci & VLAN_CFI_MASK))
83 #define skb_vlan_tag_get_prio(__skb) (((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT)
84
vlan_get_rx_ctag_filter_info(struct net_device * dev)85 static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
86 {
87 ASSERT_RTNL();
88 return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev));
89 }
90
vlan_drop_rx_ctag_filter_info(struct net_device * dev)91 static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev)
92 {
93 ASSERT_RTNL();
94 call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev);
95 }
96
vlan_get_rx_stag_filter_info(struct net_device * dev)97 static inline int vlan_get_rx_stag_filter_info(struct net_device *dev)
98 {
99 ASSERT_RTNL();
100 return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev));
101 }
102
vlan_drop_rx_stag_filter_info(struct net_device * dev)103 static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev)
104 {
105 ASSERT_RTNL();
106 call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev);
107 }
108
109 /**
110 * struct vlan_pcpu_stats - VLAN percpu rx/tx stats
111 * @rx_packets: number of received packets
112 * @rx_bytes: number of received bytes
113 * @rx_multicast: number of received multicast packets
114 * @tx_packets: number of transmitted packets
115 * @tx_bytes: number of transmitted bytes
116 * @syncp: synchronization point for 64bit counters
117 * @rx_errors: number of rx errors
118 * @tx_dropped: number of tx drops
119 */
120 struct vlan_pcpu_stats {
121 u64_stats_t rx_packets;
122 u64_stats_t rx_bytes;
123 u64_stats_t rx_multicast;
124 u64_stats_t tx_packets;
125 u64_stats_t tx_bytes;
126 struct u64_stats_sync syncp;
127 u32 rx_errors;
128 u32 tx_dropped;
129 };
130
131 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
132
133 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
134 __be16 vlan_proto, u16 vlan_id);
135 extern int vlan_for_each(struct net_device *dev,
136 int (*action)(struct net_device *dev, int vid,
137 void *arg), void *arg);
138 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
139 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
140 extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
141
142 /**
143 * struct vlan_priority_tci_mapping - vlan egress priority mappings
144 * @priority: skb priority
145 * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
146 * @next: pointer to next struct
147 */
148 struct vlan_priority_tci_mapping {
149 u32 priority;
150 u16 vlan_qos;
151 struct vlan_priority_tci_mapping *next;
152 };
153
154 struct proc_dir_entry;
155 struct netpoll;
156
157 /**
158 * struct vlan_dev_priv - VLAN private device data
159 * @nr_ingress_mappings: number of ingress priority mappings
160 * @ingress_priority_map: ingress priority mappings
161 * @nr_egress_mappings: number of egress priority mappings
162 * @egress_priority_map: hash of egress priority mappings
163 * @vlan_proto: VLAN encapsulation protocol
164 * @vlan_id: VLAN identifier
165 * @flags: device flags
166 * @real_dev: underlying netdevice
167 * @dev_tracker: refcount tracker for @real_dev reference
168 * @real_dev_addr: address of underlying netdevice
169 * @dent: proc dir entry
170 * @vlan_pcpu_stats: ptr to percpu rx stats
171 */
172 struct 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 netdevice_tracker dev_tracker;
184
185 unsigned char real_dev_addr[ETH_ALEN];
186
187 struct proc_dir_entry *dent;
188 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats;
189 #ifdef CONFIG_NET_POLL_CONTROLLER
190 struct netpoll *netpoll;
191 #endif
192 };
193
vlan_dev_priv(const struct net_device * dev)194 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
195 {
196 return netdev_priv(dev);
197 }
198
199 static inline u16
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)200 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
201 {
202 struct vlan_priority_tci_mapping *mp;
203
204 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
205
206 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
207 while (mp) {
208 if (mp->priority == skprio) {
209 return mp->vlan_qos; /* This should already be shifted
210 * to mask correctly with the
211 * VLAN's TCI */
212 }
213 mp = mp->next;
214 }
215 return 0;
216 }
217
218 extern bool vlan_do_receive(struct sk_buff **skb);
219
220 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
221 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
222
223 extern int vlan_vids_add_by_dev(struct net_device *dev,
224 const struct net_device *by_dev);
225 extern void vlan_vids_del_by_dev(struct net_device *dev,
226 const struct net_device *by_dev);
227
228 extern bool vlan_uses_dev(const struct net_device *dev);
229
230 #else
231 static inline struct net_device *
__vlan_find_dev_deep_rcu(struct net_device * real_dev,__be16 vlan_proto,u16 vlan_id)232 __vlan_find_dev_deep_rcu(struct net_device *real_dev,
233 __be16 vlan_proto, u16 vlan_id)
234 {
235 return NULL;
236 }
237
238 static inline int
vlan_for_each(struct net_device * dev,int (* action)(struct net_device * dev,int vid,void * arg),void * arg)239 vlan_for_each(struct net_device *dev,
240 int (*action)(struct net_device *dev, int vid, void *arg),
241 void *arg)
242 {
243 return 0;
244 }
245
vlan_dev_real_dev(const struct net_device * dev)246 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
247 {
248 BUG();
249 return NULL;
250 }
251
vlan_dev_vlan_id(const struct net_device * dev)252 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
253 {
254 BUG();
255 return 0;
256 }
257
vlan_dev_vlan_proto(const struct net_device * dev)258 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
259 {
260 BUG();
261 return 0;
262 }
263
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)264 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
265 u32 skprio)
266 {
267 return 0;
268 }
269
vlan_do_receive(struct sk_buff ** skb)270 static inline bool vlan_do_receive(struct sk_buff **skb)
271 {
272 return false;
273 }
274
vlan_vid_add(struct net_device * dev,__be16 proto,u16 vid)275 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
276 {
277 return 0;
278 }
279
vlan_vid_del(struct net_device * dev,__be16 proto,u16 vid)280 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
281 {
282 }
283
vlan_vids_add_by_dev(struct net_device * dev,const struct net_device * by_dev)284 static inline int vlan_vids_add_by_dev(struct net_device *dev,
285 const struct net_device *by_dev)
286 {
287 return 0;
288 }
289
vlan_vids_del_by_dev(struct net_device * dev,const struct net_device * by_dev)290 static inline void vlan_vids_del_by_dev(struct net_device *dev,
291 const struct net_device *by_dev)
292 {
293 }
294
vlan_uses_dev(const struct net_device * dev)295 static inline bool vlan_uses_dev(const struct net_device *dev)
296 {
297 return false;
298 }
299 #endif
300
301 /**
302 * eth_type_vlan - check for valid vlan ether type.
303 * @ethertype: ether type to check
304 *
305 * Returns true if the ether type is a vlan ether type.
306 */
eth_type_vlan(__be16 ethertype)307 static inline bool eth_type_vlan(__be16 ethertype)
308 {
309 switch (ethertype) {
310 case htons(ETH_P_8021Q):
311 case htons(ETH_P_8021AD):
312 return true;
313 default:
314 return false;
315 }
316 }
317
vlan_hw_offload_capable(netdev_features_t features,__be16 proto)318 static inline bool vlan_hw_offload_capable(netdev_features_t features,
319 __be16 proto)
320 {
321 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
322 return true;
323 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
324 return true;
325 return false;
326 }
327
328 /**
329 * __vlan_insert_inner_tag - inner VLAN tag inserting
330 * @skb: skbuff to tag
331 * @vlan_proto: VLAN encapsulation protocol
332 * @vlan_tci: VLAN TCI to insert
333 * @mac_len: MAC header length including outer vlan headers
334 *
335 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
336 * Returns error if skb_cow_head fails.
337 *
338 * Does not change skb->protocol so this function can be used during receive.
339 */
__vlan_insert_inner_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci,unsigned int mac_len)340 static inline int __vlan_insert_inner_tag(struct sk_buff *skb,
341 __be16 vlan_proto, u16 vlan_tci,
342 unsigned int mac_len)
343 {
344 struct vlan_ethhdr *veth;
345
346 if (skb_cow_head(skb, VLAN_HLEN) < 0)
347 return -ENOMEM;
348
349 skb_push(skb, VLAN_HLEN);
350
351 /* Move the mac header sans proto to the beginning of the new header. */
352 if (likely(mac_len > ETH_TLEN))
353 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
354 skb->mac_header -= VLAN_HLEN;
355
356 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN);
357
358 /* first, the ethernet type */
359 if (likely(mac_len >= ETH_TLEN)) {
360 /* h_vlan_encapsulated_proto should already be populated, and
361 * skb->data has space for h_vlan_proto
362 */
363 veth->h_vlan_proto = vlan_proto;
364 } else {
365 /* h_vlan_encapsulated_proto should not be populated, and
366 * skb->data has no space for h_vlan_proto
367 */
368 veth->h_vlan_encapsulated_proto = skb->protocol;
369 }
370
371 /* now, the TCI */
372 veth->h_vlan_TCI = htons(vlan_tci);
373
374 return 0;
375 }
376
377 /**
378 * __vlan_insert_tag - regular VLAN tag inserting
379 * @skb: skbuff to tag
380 * @vlan_proto: VLAN encapsulation protocol
381 * @vlan_tci: VLAN TCI to insert
382 *
383 * Inserts the VLAN tag into @skb as part of the payload
384 * Returns error if skb_cow_head fails.
385 *
386 * Does not change skb->protocol so this function can be used during receive.
387 */
__vlan_insert_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)388 static inline int __vlan_insert_tag(struct sk_buff *skb,
389 __be16 vlan_proto, u16 vlan_tci)
390 {
391 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
392 }
393
394 /**
395 * vlan_insert_inner_tag - inner VLAN tag inserting
396 * @skb: skbuff to tag
397 * @vlan_proto: VLAN encapsulation protocol
398 * @vlan_tci: VLAN TCI to insert
399 * @mac_len: MAC header length including outer vlan headers
400 *
401 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
402 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
403 *
404 * Following the skb_unshare() example, in case of error, the calling function
405 * doesn't have to worry about freeing the original skb.
406 *
407 * Does not change skb->protocol so this function can be used during receive.
408 */
vlan_insert_inner_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci,unsigned int mac_len)409 static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb,
410 __be16 vlan_proto,
411 u16 vlan_tci,
412 unsigned int mac_len)
413 {
414 int err;
415
416 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len);
417 if (err) {
418 dev_kfree_skb_any(skb);
419 return NULL;
420 }
421 return skb;
422 }
423
424 /**
425 * vlan_insert_tag - regular VLAN tag inserting
426 * @skb: skbuff to tag
427 * @vlan_proto: VLAN encapsulation protocol
428 * @vlan_tci: VLAN TCI to insert
429 *
430 * Inserts the VLAN tag into @skb as part of the payload
431 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
432 *
433 * Following the skb_unshare() example, in case of error, the calling function
434 * doesn't have to worry about freeing the original skb.
435 *
436 * Does not change skb->protocol so this function can be used during receive.
437 */
vlan_insert_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)438 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
439 __be16 vlan_proto, u16 vlan_tci)
440 {
441 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
442 }
443
444 /**
445 * vlan_insert_tag_set_proto - regular VLAN tag inserting
446 * @skb: skbuff to tag
447 * @vlan_proto: VLAN encapsulation protocol
448 * @vlan_tci: VLAN TCI to insert
449 *
450 * Inserts the VLAN tag into @skb as part of the payload
451 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
452 *
453 * Following the skb_unshare() example, in case of error, the calling function
454 * doesn't have to worry about freeing the original skb.
455 */
vlan_insert_tag_set_proto(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)456 static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
457 __be16 vlan_proto,
458 u16 vlan_tci)
459 {
460 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
461 if (skb)
462 skb->protocol = vlan_proto;
463 return skb;
464 }
465
466 /**
467 * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info
468 * @skb: skbuff to clear
469 *
470 * Clears the VLAN information from @skb
471 */
__vlan_hwaccel_clear_tag(struct sk_buff * skb)472 static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
473 {
474 skb->vlan_all = 0;
475 }
476
477 /**
478 * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb
479 * @dst: skbuff to copy to
480 * @src: skbuff to copy from
481 *
482 * Copies VLAN information from @src to @dst (for branchless code)
483 */
__vlan_hwaccel_copy_tag(struct sk_buff * dst,const struct sk_buff * src)484 static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src)
485 {
486 dst->vlan_all = src->vlan_all;
487 }
488
489 /*
490 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
491 * @skb: skbuff to tag
492 *
493 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
494 *
495 * Following the skb_unshare() example, in case of error, the calling function
496 * doesn't have to worry about freeing the original skb.
497 */
__vlan_hwaccel_push_inside(struct sk_buff * skb)498 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
499 {
500 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
501 skb_vlan_tag_get(skb));
502 if (likely(skb))
503 __vlan_hwaccel_clear_tag(skb);
504 return skb;
505 }
506
507 /**
508 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
509 * @skb: skbuff to tag
510 * @vlan_proto: VLAN encapsulation protocol
511 * @vlan_tci: VLAN TCI to insert
512 *
513 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
514 */
__vlan_hwaccel_put_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)515 static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
516 __be16 vlan_proto, u16 vlan_tci)
517 {
518 skb->vlan_proto = vlan_proto;
519 skb->vlan_tci = vlan_tci;
520 }
521
522 /**
523 * __vlan_get_tag - get the VLAN ID that is part of the payload
524 * @skb: skbuff to query
525 * @vlan_tci: buffer to store value
526 *
527 * Returns error if the skb is not of VLAN type
528 */
__vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)529 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
530 {
531 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
532
533 if (!eth_type_vlan(veth->h_vlan_proto))
534 return -EINVAL;
535
536 *vlan_tci = ntohs(veth->h_vlan_TCI);
537 return 0;
538 }
539
540 /**
541 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
542 * @skb: skbuff to query
543 * @vlan_tci: buffer to store value
544 *
545 * Returns error if @skb->vlan_tci is not set correctly
546 */
__vlan_hwaccel_get_tag(const struct sk_buff * skb,u16 * vlan_tci)547 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
548 u16 *vlan_tci)
549 {
550 if (skb_vlan_tag_present(skb)) {
551 *vlan_tci = skb_vlan_tag_get(skb);
552 return 0;
553 } else {
554 *vlan_tci = 0;
555 return -EINVAL;
556 }
557 }
558
559 /**
560 * vlan_get_tag - get the VLAN ID from the skb
561 * @skb: skbuff to query
562 * @vlan_tci: buffer to store value
563 *
564 * Returns error if the skb is not VLAN tagged
565 */
vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)566 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
567 {
568 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
569 return __vlan_hwaccel_get_tag(skb, vlan_tci);
570 } else {
571 return __vlan_get_tag(skb, vlan_tci);
572 }
573 }
574
575 /**
576 * vlan_get_protocol - get protocol EtherType.
577 * @skb: skbuff to query
578 * @type: first vlan protocol
579 * @depth: buffer to store length of eth and vlan tags in bytes
580 *
581 * Returns the EtherType of the packet, regardless of whether it is
582 * vlan encapsulated (normal or hardware accelerated) or not.
583 */
__vlan_get_protocol(const struct sk_buff * skb,__be16 type,int * depth)584 static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type,
585 int *depth)
586 {
587 unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH;
588
589 /* if type is 802.1Q/AD then the header should already be
590 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
591 * ETH_HLEN otherwise
592 */
593 if (eth_type_vlan(type)) {
594 if (vlan_depth) {
595 if (WARN_ON(vlan_depth < VLAN_HLEN))
596 return 0;
597 vlan_depth -= VLAN_HLEN;
598 } else {
599 vlan_depth = ETH_HLEN;
600 }
601 do {
602 struct vlan_hdr vhdr, *vh;
603
604 vh = skb_header_pointer(skb, vlan_depth, sizeof(vhdr), &vhdr);
605 if (unlikely(!vh || !--parse_depth))
606 return 0;
607
608 type = vh->h_vlan_encapsulated_proto;
609 vlan_depth += VLAN_HLEN;
610 } while (eth_type_vlan(type));
611 }
612
613 if (depth)
614 *depth = vlan_depth;
615
616 return type;
617 }
618
619 /**
620 * vlan_get_protocol - get protocol EtherType.
621 * @skb: skbuff to query
622 *
623 * Returns the EtherType of the packet, regardless of whether it is
624 * vlan encapsulated (normal or hardware accelerated) or not.
625 */
vlan_get_protocol(const struct sk_buff * skb)626 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
627 {
628 return __vlan_get_protocol(skb, skb->protocol, NULL);
629 }
630
631 /* A getter for the SKB protocol field which will handle VLAN tags consistently
632 * whether VLAN acceleration is enabled or not.
633 */
skb_protocol(const struct sk_buff * skb,bool skip_vlan)634 static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan)
635 {
636 if (!skip_vlan)
637 /* VLAN acceleration strips the VLAN header from the skb and
638 * moves it to skb->vlan_proto
639 */
640 return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol;
641
642 return vlan_get_protocol(skb);
643 }
644
vlan_set_encap_proto(struct sk_buff * skb,struct vlan_hdr * vhdr)645 static inline void vlan_set_encap_proto(struct sk_buff *skb,
646 struct vlan_hdr *vhdr)
647 {
648 __be16 proto;
649 unsigned short *rawp;
650
651 /*
652 * Was a VLAN packet, grab the encapsulated protocol, which the layer
653 * three protocols care about.
654 */
655
656 proto = vhdr->h_vlan_encapsulated_proto;
657 if (eth_proto_is_802_3(proto)) {
658 skb->protocol = proto;
659 return;
660 }
661
662 rawp = (unsigned short *)(vhdr + 1);
663 if (*rawp == 0xFFFF)
664 /*
665 * This is a magic hack to spot IPX packets. Older Novell
666 * breaks the protocol design and runs IPX over 802.3 without
667 * an 802.2 LLC layer. We look for FFFF which isn't a used
668 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
669 * but does for the rest.
670 */
671 skb->protocol = htons(ETH_P_802_3);
672 else
673 /*
674 * Real 802.2 LLC
675 */
676 skb->protocol = htons(ETH_P_802_2);
677 }
678
679 /**
680 * skb_vlan_tagged - check if skb is vlan tagged.
681 * @skb: skbuff to query
682 *
683 * Returns true if the skb is tagged, regardless of whether it is hardware
684 * accelerated or not.
685 */
skb_vlan_tagged(const struct sk_buff * skb)686 static inline bool skb_vlan_tagged(const struct sk_buff *skb)
687 {
688 if (!skb_vlan_tag_present(skb) &&
689 likely(!eth_type_vlan(skb->protocol)))
690 return false;
691
692 return true;
693 }
694
695 /**
696 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
697 * @skb: skbuff to query
698 *
699 * Returns true if the skb is tagged with multiple vlan headers, regardless
700 * of whether it is hardware accelerated or not.
701 */
skb_vlan_tagged_multi(struct sk_buff * skb)702 static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
703 {
704 __be16 protocol = skb->protocol;
705
706 if (!skb_vlan_tag_present(skb)) {
707 struct vlan_ethhdr *veh;
708
709 if (likely(!eth_type_vlan(protocol)))
710 return false;
711
712 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
713 return false;
714
715 veh = (struct vlan_ethhdr *)skb->data;
716 protocol = veh->h_vlan_encapsulated_proto;
717 }
718
719 if (!eth_type_vlan(protocol))
720 return false;
721
722 return true;
723 }
724
725 /**
726 * vlan_features_check - drop unsafe features for skb with multiple tags.
727 * @skb: skbuff to query
728 * @features: features to be checked
729 *
730 * Returns features without unsafe ones if the skb has multiple tags.
731 */
vlan_features_check(struct sk_buff * skb,netdev_features_t features)732 static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
733 netdev_features_t features)
734 {
735 if (skb_vlan_tagged_multi(skb)) {
736 /* In the case of multi-tagged packets, use a direct mask
737 * instead of using netdev_interesect_features(), to make
738 * sure that only devices supporting NETIF_F_HW_CSUM will
739 * have checksum offloading support.
740 */
741 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
742 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
743 NETIF_F_HW_VLAN_STAG_TX;
744 }
745
746 return features;
747 }
748
749 /**
750 * compare_vlan_header - Compare two vlan headers
751 * @h1: Pointer to vlan header
752 * @h2: Pointer to vlan header
753 *
754 * Compare two vlan headers, returns 0 if equal.
755 *
756 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
757 */
compare_vlan_header(const struct vlan_hdr * h1,const struct vlan_hdr * h2)758 static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
759 const struct vlan_hdr *h2)
760 {
761 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
762 return *(u32 *)h1 ^ *(u32 *)h2;
763 #else
764 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
765 ((__force u32)h1->h_vlan_encapsulated_proto ^
766 (__force u32)h2->h_vlan_encapsulated_proto);
767 #endif
768 }
769 #endif /* !(_LINUX_IF_VLAN_H_) */
770