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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 /*
34  * 	struct vlan_hdr - vlan header
35  * 	@h_vlan_TCI: priority and VLAN ID
36  *	@h_vlan_encapsulated_proto: packet type ID or len
37  */
38 struct vlan_hdr {
39 	__be16	h_vlan_TCI;
40 	__be16	h_vlan_encapsulated_proto;
41 };
42 
43 /**
44  *	struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
45  *	@h_dest: destination ethernet address
46  *	@h_source: source ethernet address
47  *	@h_vlan_proto: ethernet protocol
48  *	@h_vlan_TCI: priority and VLAN ID
49  *	@h_vlan_encapsulated_proto: packet type ID or len
50  */
51 struct vlan_ethhdr {
52 	unsigned char	h_dest[ETH_ALEN];
53 	unsigned char	h_source[ETH_ALEN];
54 	__be16		h_vlan_proto;
55 	__be16		h_vlan_TCI;
56 	__be16		h_vlan_encapsulated_proto;
57 };
58 
59 #include <linux/skbuff.h>
60 
vlan_eth_hdr(const struct sk_buff * skb)61 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
62 {
63 	return (struct vlan_ethhdr *)skb_mac_header(skb);
64 }
65 
66 #define VLAN_PRIO_MASK		0xe000 /* Priority Code Point */
67 #define VLAN_PRIO_SHIFT		13
68 #define VLAN_CFI_MASK		0x1000 /* Canonical Format Indicator */
69 #define VLAN_TAG_PRESENT	VLAN_CFI_MASK
70 #define VLAN_VID_MASK		0x0fff /* VLAN Identifier */
71 #define VLAN_N_VID		4096
72 
73 /* found in socket.c */
74 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
75 
is_vlan_dev(struct net_device * dev)76 static inline bool is_vlan_dev(struct net_device *dev)
77 {
78         return dev->priv_flags & IFF_802_1Q_VLAN;
79 }
80 
81 #define vlan_tx_tag_present(__skb)	((__skb)->vlan_tci & VLAN_TAG_PRESENT)
82 #define vlan_tx_tag_get(__skb)		((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
83 #define vlan_tx_tag_get_id(__skb)	((__skb)->vlan_tci & VLAN_VID_MASK)
84 
85 /**
86  *	struct vlan_pcpu_stats - VLAN percpu rx/tx stats
87  *	@rx_packets: number of received packets
88  *	@rx_bytes: number of received bytes
89  *	@rx_multicast: number of received multicast packets
90  *	@tx_packets: number of transmitted packets
91  *	@tx_bytes: number of transmitted bytes
92  *	@syncp: synchronization point for 64bit counters
93  *	@rx_errors: number of rx errors
94  *	@tx_dropped: number of tx drops
95  */
96 struct vlan_pcpu_stats {
97 	u64			rx_packets;
98 	u64			rx_bytes;
99 	u64			rx_multicast;
100 	u64			tx_packets;
101 	u64			tx_bytes;
102 	struct u64_stats_sync	syncp;
103 	u32			rx_errors;
104 	u32			tx_dropped;
105 };
106 
107 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
108 
109 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
110 					       __be16 vlan_proto, u16 vlan_id);
111 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
112 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
113 extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
114 
115 /**
116  *	struct vlan_priority_tci_mapping - vlan egress priority mappings
117  *	@priority: skb priority
118  *	@vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
119  *	@next: pointer to next struct
120  */
121 struct vlan_priority_tci_mapping {
122 	u32					priority;
123 	u16					vlan_qos;
124 	struct vlan_priority_tci_mapping	*next;
125 };
126 
127 struct proc_dir_entry;
128 struct netpoll;
129 
130 /**
131  *	struct vlan_dev_priv - VLAN private device data
132  *	@nr_ingress_mappings: number of ingress priority mappings
133  *	@ingress_priority_map: ingress priority mappings
134  *	@nr_egress_mappings: number of egress priority mappings
135  *	@egress_priority_map: hash of egress priority mappings
136  *	@vlan_proto: VLAN encapsulation protocol
137  *	@vlan_id: VLAN identifier
138  *	@flags: device flags
139  *	@real_dev: underlying netdevice
140  *	@real_dev_addr: address of underlying netdevice
141  *	@dent: proc dir entry
142  *	@vlan_pcpu_stats: ptr to percpu rx stats
143  */
144 struct vlan_dev_priv {
145 	unsigned int				nr_ingress_mappings;
146 	u32					ingress_priority_map[8];
147 	unsigned int				nr_egress_mappings;
148 	struct vlan_priority_tci_mapping	*egress_priority_map[16];
149 
150 	__be16					vlan_proto;
151 	u16					vlan_id;
152 	u16					flags;
153 
154 	struct net_device			*real_dev;
155 	unsigned char				real_dev_addr[ETH_ALEN];
156 
157 	struct proc_dir_entry			*dent;
158 	struct vlan_pcpu_stats __percpu		*vlan_pcpu_stats;
159 #ifdef CONFIG_NET_POLL_CONTROLLER
160 	struct netpoll				*netpoll;
161 #endif
162 	unsigned int				nest_level;
163 };
164 
vlan_dev_priv(const struct net_device * dev)165 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
166 {
167 	return netdev_priv(dev);
168 }
169 
170 static inline u16
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)171 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
172 {
173 	struct vlan_priority_tci_mapping *mp;
174 
175 	smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
176 
177 	mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
178 	while (mp) {
179 		if (mp->priority == skprio) {
180 			return mp->vlan_qos; /* This should already be shifted
181 					      * to mask correctly with the
182 					      * VLAN's TCI */
183 		}
184 		mp = mp->next;
185 	}
186 	return 0;
187 }
188 
189 extern bool vlan_do_receive(struct sk_buff **skb);
190 
191 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
192 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
193 
194 extern int vlan_vids_add_by_dev(struct net_device *dev,
195 				const struct net_device *by_dev);
196 extern void vlan_vids_del_by_dev(struct net_device *dev,
197 				 const struct net_device *by_dev);
198 
199 extern bool vlan_uses_dev(const struct net_device *dev);
200 
vlan_get_encap_level(struct net_device * dev)201 static inline int vlan_get_encap_level(struct net_device *dev)
202 {
203 	BUG_ON(!is_vlan_dev(dev));
204 	return vlan_dev_priv(dev)->nest_level;
205 }
206 #else
207 static inline struct net_device *
__vlan_find_dev_deep_rcu(struct net_device * real_dev,__be16 vlan_proto,u16 vlan_id)208 __vlan_find_dev_deep_rcu(struct net_device *real_dev,
209 		     __be16 vlan_proto, u16 vlan_id)
210 {
211 	return NULL;
212 }
213 
vlan_dev_real_dev(const struct net_device * dev)214 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
215 {
216 	BUG();
217 	return NULL;
218 }
219 
vlan_dev_vlan_id(const struct net_device * dev)220 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
221 {
222 	BUG();
223 	return 0;
224 }
225 
vlan_dev_vlan_proto(const struct net_device * dev)226 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
227 {
228 	BUG();
229 	return 0;
230 }
231 
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)232 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
233 					       u32 skprio)
234 {
235 	return 0;
236 }
237 
vlan_do_receive(struct sk_buff ** skb)238 static inline bool vlan_do_receive(struct sk_buff **skb)
239 {
240 	return false;
241 }
242 
vlan_vid_add(struct net_device * dev,__be16 proto,u16 vid)243 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
244 {
245 	return 0;
246 }
247 
vlan_vid_del(struct net_device * dev,__be16 proto,u16 vid)248 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
249 {
250 }
251 
vlan_vids_add_by_dev(struct net_device * dev,const struct net_device * by_dev)252 static inline int vlan_vids_add_by_dev(struct net_device *dev,
253 				       const struct net_device *by_dev)
254 {
255 	return 0;
256 }
257 
vlan_vids_del_by_dev(struct net_device * dev,const struct net_device * by_dev)258 static inline void vlan_vids_del_by_dev(struct net_device *dev,
259 					const struct net_device *by_dev)
260 {
261 }
262 
vlan_uses_dev(const struct net_device * dev)263 static inline bool vlan_uses_dev(const struct net_device *dev)
264 {
265 	return false;
266 }
vlan_get_encap_level(struct net_device * dev)267 static inline int vlan_get_encap_level(struct net_device *dev)
268 {
269 	BUG();
270 	return 0;
271 }
272 #endif
273 
vlan_hw_offload_capable(netdev_features_t features,__be16 proto)274 static inline bool vlan_hw_offload_capable(netdev_features_t features,
275 					   __be16 proto)
276 {
277 	if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
278 		return true;
279 	if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
280 		return true;
281 	return false;
282 }
283 
284 /**
285  * vlan_insert_tag - regular VLAN tag inserting
286  * @skb: skbuff to tag
287  * @vlan_proto: VLAN encapsulation protocol
288  * @vlan_tci: VLAN TCI to insert
289  *
290  * Inserts the VLAN tag into @skb as part of the payload
291  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
292  *
293  * Following the skb_unshare() example, in case of error, the calling function
294  * doesn't have to worry about freeing the original skb.
295  *
296  * Does not change skb->protocol so this function can be used during receive.
297  */
vlan_insert_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)298 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
299 					      __be16 vlan_proto, u16 vlan_tci)
300 {
301 	struct vlan_ethhdr *veth;
302 
303 	if (skb_cow_head(skb, VLAN_HLEN) < 0) {
304 		dev_kfree_skb_any(skb);
305 		return NULL;
306 	}
307 	veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
308 
309 	/* Move the mac addresses to the beginning of the new header. */
310 	memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
311 	skb->mac_header -= VLAN_HLEN;
312 
313 	/* first, the ethernet type */
314 	veth->h_vlan_proto = vlan_proto;
315 
316 	/* now, the TCI */
317 	veth->h_vlan_TCI = htons(vlan_tci);
318 
319 	return skb;
320 }
321 
322 /**
323  * vlan_insert_tag_set_proto - regular VLAN tag inserting
324  * @skb: skbuff to tag
325  * @vlan_proto: VLAN encapsulation protocol
326  * @vlan_tci: VLAN TCI to insert
327  *
328  * Inserts the VLAN tag into @skb as part of the payload
329  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
330  *
331  * Following the skb_unshare() example, in case of error, the calling function
332  * doesn't have to worry about freeing the original skb.
333  */
vlan_insert_tag_set_proto(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)334 static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
335 							__be16 vlan_proto,
336 							u16 vlan_tci)
337 {
338 	skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
339 	if (skb)
340 		skb->protocol = vlan_proto;
341 	return skb;
342 }
343 
344 /*
345  * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
346  * @skb: skbuff to tag
347  *
348  * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
349  *
350  * Following the skb_unshare() example, in case of error, the calling function
351  * doesn't have to worry about freeing the original skb.
352  */
__vlan_hwaccel_push_inside(struct sk_buff * skb)353 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
354 {
355 	skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
356 					vlan_tx_tag_get(skb));
357 	if (likely(skb))
358 		skb->vlan_tci = 0;
359 	return skb;
360 }
361 /*
362  * vlan_hwaccel_push_inside - pushes vlan tag to the payload
363  * @skb: skbuff to tag
364  *
365  * Checks is tag is present in @skb->vlan_tci and if it is, it pushes the
366  * VLAN tag from @skb->vlan_tci inside to the payload.
367  *
368  * Following the skb_unshare() example, in case of error, the calling function
369  * doesn't have to worry about freeing the original skb.
370  */
vlan_hwaccel_push_inside(struct sk_buff * skb)371 static inline struct sk_buff *vlan_hwaccel_push_inside(struct sk_buff *skb)
372 {
373 	if (vlan_tx_tag_present(skb))
374 		skb = __vlan_hwaccel_push_inside(skb);
375 	return skb;
376 }
377 
378 /**
379  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
380  * @skb: skbuff to tag
381  * @vlan_proto: VLAN encapsulation protocol
382  * @vlan_tci: VLAN TCI to insert
383  *
384  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
385  */
__vlan_hwaccel_put_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)386 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
387 						     __be16 vlan_proto,
388 						     u16 vlan_tci)
389 {
390 	skb->vlan_proto = vlan_proto;
391 	skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
392 	return skb;
393 }
394 
395 /**
396  * __vlan_get_tag - get the VLAN ID that is part of the payload
397  * @skb: skbuff to query
398  * @vlan_tci: buffer to store vlaue
399  *
400  * Returns error if the skb is not of VLAN type
401  */
__vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)402 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
403 {
404 	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
405 
406 	if (veth->h_vlan_proto != htons(ETH_P_8021Q) &&
407 	    veth->h_vlan_proto != htons(ETH_P_8021AD))
408 		return -EINVAL;
409 
410 	*vlan_tci = ntohs(veth->h_vlan_TCI);
411 	return 0;
412 }
413 
414 /**
415  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
416  * @skb: skbuff to query
417  * @vlan_tci: buffer to store vlaue
418  *
419  * Returns error if @skb->vlan_tci is not set correctly
420  */
__vlan_hwaccel_get_tag(const struct sk_buff * skb,u16 * vlan_tci)421 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
422 					 u16 *vlan_tci)
423 {
424 	if (vlan_tx_tag_present(skb)) {
425 		*vlan_tci = vlan_tx_tag_get(skb);
426 		return 0;
427 	} else {
428 		*vlan_tci = 0;
429 		return -EINVAL;
430 	}
431 }
432 
433 #define HAVE_VLAN_GET_TAG
434 
435 /**
436  * vlan_get_tag - get the VLAN ID from the skb
437  * @skb: skbuff to query
438  * @vlan_tci: buffer to store vlaue
439  *
440  * Returns error if the skb is not VLAN tagged
441  */
vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)442 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
443 {
444 	if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
445 		return __vlan_hwaccel_get_tag(skb, vlan_tci);
446 	} else {
447 		return __vlan_get_tag(skb, vlan_tci);
448 	}
449 }
450 
451 /**
452  * vlan_get_protocol - get protocol EtherType.
453  * @skb: skbuff to query
454  *
455  * Returns the EtherType of the packet, regardless of whether it is
456  * vlan encapsulated (normal or hardware accelerated) or not.
457  */
vlan_get_protocol(const struct sk_buff * skb)458 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
459 {
460 	__be16 protocol = 0;
461 
462 	if (vlan_tx_tag_present(skb) ||
463 	     skb->protocol != cpu_to_be16(ETH_P_8021Q))
464 		protocol = skb->protocol;
465 	else {
466 		__be16 proto, *protop;
467 		protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
468 						h_vlan_encapsulated_proto),
469 						sizeof(proto), &proto);
470 		if (likely(protop))
471 			protocol = *protop;
472 	}
473 
474 	return protocol;
475 }
476 
vlan_set_encap_proto(struct sk_buff * skb,struct vlan_hdr * vhdr)477 static inline void vlan_set_encap_proto(struct sk_buff *skb,
478 					struct vlan_hdr *vhdr)
479 {
480 	__be16 proto;
481 	unsigned short *rawp;
482 
483 	/*
484 	 * Was a VLAN packet, grab the encapsulated protocol, which the layer
485 	 * three protocols care about.
486 	 */
487 
488 	proto = vhdr->h_vlan_encapsulated_proto;
489 	if (ntohs(proto) >= ETH_P_802_3_MIN) {
490 		skb->protocol = proto;
491 		return;
492 	}
493 
494 	rawp = (unsigned short *)(vhdr + 1);
495 	if (*rawp == 0xFFFF)
496 		/*
497 		 * This is a magic hack to spot IPX packets. Older Novell
498 		 * breaks the protocol design and runs IPX over 802.3 without
499 		 * an 802.2 LLC layer. We look for FFFF which isn't a used
500 		 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
501 		 * but does for the rest.
502 		 */
503 		skb->protocol = htons(ETH_P_802_3);
504 	else
505 		/*
506 		 * Real 802.2 LLC
507 		 */
508 		skb->protocol = htons(ETH_P_802_2);
509 }
510 
511 #endif /* !(_LINUX_IF_VLAN_H_) */
512