1 /*
2  * VLAN		An implementation of 802.1Q VLAN tagging.
3  *
4  * Authors:	Ben Greear <greearb@candelatech.com>
5  *
6  *		This program is free software; you can redistribute it and/or
7  *		modify it under the terms of the GNU General Public License
8  *		as published by the Free Software Foundation; either version
9  *		2 of the License, or (at your option) any later version.
10  *
11  */
12 #ifndef _LINUX_IF_VLAN_H_
13 #define _LINUX_IF_VLAN_H_
14 
15 #include <linux/netdevice.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/bug.h>
19 #include <uapi/linux/if_vlan.h>
20 
21 #define VLAN_HLEN	4		/* The additional bytes required by VLAN
22 					 * (in addition to the Ethernet header)
23 					 */
24 #define VLAN_ETH_HLEN	18		/* Total octets in header.	 */
25 #define VLAN_ETH_ZLEN	64		/* Min. octets in frame sans FCS */
26 
27 /*
28  * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
29  */
30 #define VLAN_ETH_DATA_LEN	1500	/* Max. octets in payload	 */
31 #define VLAN_ETH_FRAME_LEN	1518	/* Max. octets in frame sans FCS */
32 
33 #define VLAN_MAX_DEPTH	8		/* Max. number of nested VLAN tags parsed */
34 
35 /*
36  * 	struct vlan_hdr - vlan header
37  * 	@h_vlan_TCI: priority and VLAN ID
38  *	@h_vlan_encapsulated_proto: packet type ID or len
39  */
40 struct vlan_hdr {
41 	__be16	h_vlan_TCI;
42 	__be16	h_vlan_encapsulated_proto;
43 };
44 
45 /**
46  *	struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
47  *	@h_dest: destination ethernet address
48  *	@h_source: source ethernet address
49  *	@h_vlan_proto: ethernet protocol
50  *	@h_vlan_TCI: priority and VLAN ID
51  *	@h_vlan_encapsulated_proto: packet type ID or len
52  */
53 struct vlan_ethhdr {
54 	unsigned char	h_dest[ETH_ALEN];
55 	unsigned char	h_source[ETH_ALEN];
56 	__be16		h_vlan_proto;
57 	__be16		h_vlan_TCI;
58 	__be16		h_vlan_encapsulated_proto;
59 };
60 
61 #include <linux/skbuff.h>
62 
vlan_eth_hdr(const struct sk_buff * skb)63 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
64 {
65 	return (struct vlan_ethhdr *)skb_mac_header(skb);
66 }
67 
68 #define VLAN_PRIO_MASK		0xe000 /* Priority Code Point */
69 #define VLAN_PRIO_SHIFT		13
70 #define VLAN_CFI_MASK		0x1000 /* Canonical Format Indicator */
71 #define VLAN_TAG_PRESENT	VLAN_CFI_MASK
72 #define VLAN_VID_MASK		0x0fff /* VLAN Identifier */
73 #define VLAN_N_VID		4096
74 
75 /* found in socket.c */
76 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
77 
is_vlan_dev(const struct net_device * dev)78 static inline bool is_vlan_dev(const struct net_device *dev)
79 {
80         return dev->priv_flags & IFF_802_1Q_VLAN;
81 }
82 
83 #define skb_vlan_tag_present(__skb)	((__skb)->vlan_tci & VLAN_TAG_PRESENT)
84 #define skb_vlan_tag_get(__skb)		((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
85 #define skb_vlan_tag_get_id(__skb)	((__skb)->vlan_tci & VLAN_VID_MASK)
86 #define skb_vlan_tag_get_prio(__skb)	((__skb)->vlan_tci & VLAN_PRIO_MASK)
87 
vlan_get_rx_ctag_filter_info(struct net_device * dev)88 static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
89 {
90 	ASSERT_RTNL();
91 	return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev));
92 }
93 
vlan_drop_rx_ctag_filter_info(struct net_device * dev)94 static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev)
95 {
96 	ASSERT_RTNL();
97 	call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev);
98 }
99 
vlan_get_rx_stag_filter_info(struct net_device * dev)100 static inline int vlan_get_rx_stag_filter_info(struct net_device *dev)
101 {
102 	ASSERT_RTNL();
103 	return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev));
104 }
105 
vlan_drop_rx_stag_filter_info(struct net_device * dev)106 static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev)
107 {
108 	ASSERT_RTNL();
109 	call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev);
110 }
111 
112 /**
113  *	struct vlan_pcpu_stats - VLAN percpu rx/tx stats
114  *	@rx_packets: number of received packets
115  *	@rx_bytes: number of received bytes
116  *	@rx_multicast: number of received multicast packets
117  *	@tx_packets: number of transmitted packets
118  *	@tx_bytes: number of transmitted bytes
119  *	@syncp: synchronization point for 64bit counters
120  *	@rx_errors: number of rx errors
121  *	@tx_dropped: number of tx drops
122  */
123 struct vlan_pcpu_stats {
124 	u64			rx_packets;
125 	u64			rx_bytes;
126 	u64			rx_multicast;
127 	u64			tx_packets;
128 	u64			tx_bytes;
129 	struct u64_stats_sync	syncp;
130 	u32			rx_errors;
131 	u32			tx_dropped;
132 };
133 
134 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
135 
136 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
137 					       __be16 vlan_proto, u16 vlan_id);
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  *	@real_dev_addr: address of underlying netdevice
168  *	@dent: proc dir entry
169  *	@vlan_pcpu_stats: ptr to percpu rx stats
170  */
171 struct vlan_dev_priv {
172 	unsigned int				nr_ingress_mappings;
173 	u32					ingress_priority_map[8];
174 	unsigned int				nr_egress_mappings;
175 	struct vlan_priority_tci_mapping	*egress_priority_map[16];
176 
177 	__be16					vlan_proto;
178 	u16					vlan_id;
179 	u16					flags;
180 
181 	struct net_device			*real_dev;
182 	unsigned char				real_dev_addr[ETH_ALEN];
183 
184 	struct proc_dir_entry			*dent;
185 	struct vlan_pcpu_stats __percpu		*vlan_pcpu_stats;
186 #ifdef CONFIG_NET_POLL_CONTROLLER
187 	struct netpoll				*netpoll;
188 #endif
189 	unsigned int				nest_level;
190 };
191 
vlan_dev_priv(const struct net_device * dev)192 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
193 {
194 	return netdev_priv(dev);
195 }
196 
197 static inline u16
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)198 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
199 {
200 	struct vlan_priority_tci_mapping *mp;
201 
202 	smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
203 
204 	mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
205 	while (mp) {
206 		if (mp->priority == skprio) {
207 			return mp->vlan_qos; /* This should already be shifted
208 					      * to mask correctly with the
209 					      * VLAN's TCI */
210 		}
211 		mp = mp->next;
212 	}
213 	return 0;
214 }
215 
216 extern bool vlan_do_receive(struct sk_buff **skb);
217 
218 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
219 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
220 
221 extern int vlan_vids_add_by_dev(struct net_device *dev,
222 				const struct net_device *by_dev);
223 extern void vlan_vids_del_by_dev(struct net_device *dev,
224 				 const struct net_device *by_dev);
225 
226 extern bool vlan_uses_dev(const struct net_device *dev);
227 
vlan_get_encap_level(struct net_device * dev)228 static inline int vlan_get_encap_level(struct net_device *dev)
229 {
230 	BUG_ON(!is_vlan_dev(dev));
231 	return vlan_dev_priv(dev)->nest_level;
232 }
233 #else
234 static inline struct net_device *
__vlan_find_dev_deep_rcu(struct net_device * real_dev,__be16 vlan_proto,u16 vlan_id)235 __vlan_find_dev_deep_rcu(struct net_device *real_dev,
236 		     __be16 vlan_proto, u16 vlan_id)
237 {
238 	return NULL;
239 }
240 
vlan_dev_real_dev(const struct net_device * dev)241 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
242 {
243 	BUG();
244 	return NULL;
245 }
246 
vlan_dev_vlan_id(const struct net_device * dev)247 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
248 {
249 	BUG();
250 	return 0;
251 }
252 
vlan_dev_vlan_proto(const struct net_device * dev)253 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
254 {
255 	BUG();
256 	return 0;
257 }
258 
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)259 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
260 					       u32 skprio)
261 {
262 	return 0;
263 }
264 
vlan_do_receive(struct sk_buff ** skb)265 static inline bool vlan_do_receive(struct sk_buff **skb)
266 {
267 	return false;
268 }
269 
vlan_vid_add(struct net_device * dev,__be16 proto,u16 vid)270 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
271 {
272 	return 0;
273 }
274 
vlan_vid_del(struct net_device * dev,__be16 proto,u16 vid)275 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
276 {
277 }
278 
vlan_vids_add_by_dev(struct net_device * dev,const struct net_device * by_dev)279 static inline int vlan_vids_add_by_dev(struct net_device *dev,
280 				       const struct net_device *by_dev)
281 {
282 	return 0;
283 }
284 
vlan_vids_del_by_dev(struct net_device * dev,const struct net_device * by_dev)285 static inline void vlan_vids_del_by_dev(struct net_device *dev,
286 					const struct net_device *by_dev)
287 {
288 }
289 
vlan_uses_dev(const struct net_device * dev)290 static inline bool vlan_uses_dev(const struct net_device *dev)
291 {
292 	return false;
293 }
vlan_get_encap_level(struct net_device * dev)294 static inline int vlan_get_encap_level(struct net_device *dev)
295 {
296 	BUG();
297 	return 0;
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_push_inside - pushes vlan tag to the payload
468  * @skb: skbuff to tag
469  *
470  * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
471  *
472  * Following the skb_unshare() example, in case of error, the calling function
473  * doesn't have to worry about freeing the original skb.
474  */
__vlan_hwaccel_push_inside(struct sk_buff * skb)475 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
476 {
477 	skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
478 					skb_vlan_tag_get(skb));
479 	if (likely(skb))
480 		skb->vlan_tci = 0;
481 	return skb;
482 }
483 
484 /**
485  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
486  * @skb: skbuff to tag
487  * @vlan_proto: VLAN encapsulation protocol
488  * @vlan_tci: VLAN TCI to insert
489  *
490  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
491  */
__vlan_hwaccel_put_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)492 static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
493 					  __be16 vlan_proto, u16 vlan_tci)
494 {
495 	skb->vlan_proto = vlan_proto;
496 	skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
497 }
498 
499 /**
500  * __vlan_get_tag - get the VLAN ID that is part of the payload
501  * @skb: skbuff to query
502  * @vlan_tci: buffer to store value
503  *
504  * Returns error if the skb is not of VLAN type
505  */
__vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)506 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
507 {
508 	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
509 
510 	if (!eth_type_vlan(veth->h_vlan_proto))
511 		return -EINVAL;
512 
513 	*vlan_tci = ntohs(veth->h_vlan_TCI);
514 	return 0;
515 }
516 
517 /**
518  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
519  * @skb: skbuff to query
520  * @vlan_tci: buffer to store value
521  *
522  * Returns error if @skb->vlan_tci is not set correctly
523  */
__vlan_hwaccel_get_tag(const struct sk_buff * skb,u16 * vlan_tci)524 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
525 					 u16 *vlan_tci)
526 {
527 	if (skb_vlan_tag_present(skb)) {
528 		*vlan_tci = skb_vlan_tag_get(skb);
529 		return 0;
530 	} else {
531 		*vlan_tci = 0;
532 		return -EINVAL;
533 	}
534 }
535 
536 #define HAVE_VLAN_GET_TAG
537 
538 /**
539  * vlan_get_tag - get the VLAN ID from the skb
540  * @skb: skbuff to query
541  * @vlan_tci: buffer to store value
542  *
543  * Returns error if the skb is not VLAN tagged
544  */
vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)545 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
546 {
547 	if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
548 		return __vlan_hwaccel_get_tag(skb, vlan_tci);
549 	} else {
550 		return __vlan_get_tag(skb, vlan_tci);
551 	}
552 }
553 
554 /**
555  * vlan_get_protocol - get protocol EtherType.
556  * @skb: skbuff to query
557  * @type: first vlan protocol
558  * @depth: buffer to store length of eth and vlan tags in bytes
559  *
560  * Returns the EtherType of the packet, regardless of whether it is
561  * vlan encapsulated (normal or hardware accelerated) or not.
562  */
__vlan_get_protocol(const struct sk_buff * skb,__be16 type,int * depth)563 static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type,
564 					 int *depth)
565 {
566 	unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH;
567 
568 	/* if type is 802.1Q/AD then the header should already be
569 	 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
570 	 * ETH_HLEN otherwise
571 	 */
572 	if (eth_type_vlan(type)) {
573 		if (vlan_depth) {
574 			if (WARN_ON(vlan_depth < VLAN_HLEN))
575 				return 0;
576 			vlan_depth -= VLAN_HLEN;
577 		} else {
578 			vlan_depth = ETH_HLEN;
579 		}
580 		do {
581 			struct vlan_hdr vhdr, *vh;
582 
583 			vh = skb_header_pointer(skb, vlan_depth, sizeof(vhdr), &vhdr);
584 			if (unlikely(!vh || !--parse_depth))
585 				return 0;
586 
587 			type = vh->h_vlan_encapsulated_proto;
588 			vlan_depth += VLAN_HLEN;
589 		} while (eth_type_vlan(type));
590 	}
591 
592 	if (depth)
593 		*depth = vlan_depth;
594 
595 	return type;
596 }
597 
598 /**
599  * vlan_get_protocol - get protocol EtherType.
600  * @skb: skbuff to query
601  *
602  * Returns the EtherType of the packet, regardless of whether it is
603  * vlan encapsulated (normal or hardware accelerated) or not.
604  */
vlan_get_protocol(const struct sk_buff * skb)605 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
606 {
607 	return __vlan_get_protocol(skb, skb->protocol, NULL);
608 }
609 
610 /* A getter for the SKB protocol field which will handle VLAN tags consistently
611  * whether VLAN acceleration is enabled or not.
612  */
skb_protocol(const struct sk_buff * skb,bool skip_vlan)613 static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan)
614 {
615 	if (!skip_vlan)
616 		/* VLAN acceleration strips the VLAN header from the skb and
617 		 * moves it to skb->vlan_proto
618 		 */
619 		return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol;
620 
621 	return vlan_get_protocol(skb);
622 }
623 
vlan_set_encap_proto(struct sk_buff * skb,struct vlan_hdr * vhdr)624 static inline void vlan_set_encap_proto(struct sk_buff *skb,
625 					struct vlan_hdr *vhdr)
626 {
627 	__be16 proto;
628 	unsigned short *rawp;
629 
630 	/*
631 	 * Was a VLAN packet, grab the encapsulated protocol, which the layer
632 	 * three protocols care about.
633 	 */
634 
635 	proto = vhdr->h_vlan_encapsulated_proto;
636 	if (eth_proto_is_802_3(proto)) {
637 		skb->protocol = proto;
638 		return;
639 	}
640 
641 	rawp = (unsigned short *)(vhdr + 1);
642 	if (*rawp == 0xFFFF)
643 		/*
644 		 * This is a magic hack to spot IPX packets. Older Novell
645 		 * breaks the protocol design and runs IPX over 802.3 without
646 		 * an 802.2 LLC layer. We look for FFFF which isn't a used
647 		 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
648 		 * but does for the rest.
649 		 */
650 		skb->protocol = htons(ETH_P_802_3);
651 	else
652 		/*
653 		 * Real 802.2 LLC
654 		 */
655 		skb->protocol = htons(ETH_P_802_2);
656 }
657 
658 /**
659  * skb_vlan_tagged - check if skb is vlan tagged.
660  * @skb: skbuff to query
661  *
662  * Returns true if the skb is tagged, regardless of whether it is hardware
663  * accelerated or not.
664  */
skb_vlan_tagged(const struct sk_buff * skb)665 static inline bool skb_vlan_tagged(const struct sk_buff *skb)
666 {
667 	if (!skb_vlan_tag_present(skb) &&
668 	    likely(!eth_type_vlan(skb->protocol)))
669 		return false;
670 
671 	return true;
672 }
673 
674 /**
675  * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
676  * @skb: skbuff to query
677  *
678  * Returns true if the skb is tagged with multiple vlan headers, regardless
679  * of whether it is hardware accelerated or not.
680  */
skb_vlan_tagged_multi(struct sk_buff * skb)681 static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
682 {
683 	__be16 protocol = skb->protocol;
684 
685 	if (!skb_vlan_tag_present(skb)) {
686 		struct vlan_ethhdr *veh;
687 
688 		if (likely(!eth_type_vlan(protocol)))
689 			return false;
690 
691 		if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
692 			return false;
693 
694 		veh = (struct vlan_ethhdr *)skb->data;
695 		protocol = veh->h_vlan_encapsulated_proto;
696 	}
697 
698 	if (!eth_type_vlan(protocol))
699 		return false;
700 
701 	return true;
702 }
703 
704 /**
705  * vlan_features_check - drop unsafe features for skb with multiple tags.
706  * @skb: skbuff to query
707  * @features: features to be checked
708  *
709  * Returns features without unsafe ones if the skb has multiple tags.
710  */
vlan_features_check(struct sk_buff * skb,netdev_features_t features)711 static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
712 						    netdev_features_t features)
713 {
714 	if (skb_vlan_tagged_multi(skb)) {
715 		/* In the case of multi-tagged packets, use a direct mask
716 		 * instead of using netdev_interesect_features(), to make
717 		 * sure that only devices supporting NETIF_F_HW_CSUM will
718 		 * have checksum offloading support.
719 		 */
720 		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
721 			    NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
722 			    NETIF_F_HW_VLAN_STAG_TX;
723 	}
724 
725 	return features;
726 }
727 
728 /**
729  * compare_vlan_header - Compare two vlan headers
730  * @h1: Pointer to vlan header
731  * @h2: Pointer to vlan header
732  *
733  * Compare two vlan headers, returns 0 if equal.
734  *
735  * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
736  */
compare_vlan_header(const struct vlan_hdr * h1,const struct vlan_hdr * h2)737 static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
738 						const struct vlan_hdr *h2)
739 {
740 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
741 	return *(u32 *)h1 ^ *(u32 *)h2;
742 #else
743 	return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
744 	       ((__force u32)h1->h_vlan_encapsulated_proto ^
745 		(__force u32)h2->h_vlan_encapsulated_proto);
746 #endif
747 }
748 #endif /* !(_LINUX_IF_VLAN_H_) */
749