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