summaryrefslogtreecommitdiffstats
path: root/include/linux/if_vlan.h
blob: cdcbafa9b39a0a80082d9c2c9123edae798142a4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
/*
 * VLAN		An implementation of 802.1Q VLAN tagging.
 *
 * Authors:	Ben Greear <greearb@candelatech.com>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 */
#ifndef _LINUX_IF_VLAN_H_
#define _LINUX_IF_VLAN_H_

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <linux/bug.h>
#include <uapi/linux/if_vlan.h>

#define VLAN_HLEN	4		/* The additional bytes required by VLAN
					 * (in addition to the Ethernet header)
					 */
#define VLAN_ETH_HLEN	18		/* Total octets in header.	 */
#define VLAN_ETH_ZLEN	64		/* Min. octets in frame sans FCS */

/*
 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
 */
#define VLAN_ETH_DATA_LEN	1500	/* Max. octets in payload	 */
#define VLAN_ETH_FRAME_LEN	1518	/* Max. octets in frame sans FCS */

/*
 * 	struct vlan_hdr - vlan header
 * 	@h_vlan_TCI: priority and VLAN ID
 *	@h_vlan_encapsulated_proto: packet type ID or len
 */
struct vlan_hdr {
	__be16	h_vlan_TCI;
	__be16	h_vlan_encapsulated_proto;
};

/**
 *	struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
 *	@h_dest: destination ethernet address
 *	@h_source: source ethernet address
 *	@h_vlan_proto: ethernet protocol
 *	@h_vlan_TCI: priority and VLAN ID
 *	@h_vlan_encapsulated_proto: packet type ID or len
 */
struct vlan_ethhdr {
	unsigned char	h_dest[ETH_ALEN];
	unsigned char	h_source[ETH_ALEN];
	__be16		h_vlan_proto;
	__be16		h_vlan_TCI;
	__be16		h_vlan_encapsulated_proto;
};

#include <linux/skbuff.h>

static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
{
	return (struct vlan_ethhdr *)skb_mac_header(skb);
}

#define VLAN_PRIO_MASK		0xe000 /* Priority Code Point */
#define VLAN_PRIO_SHIFT		13
#define VLAN_CFI_MASK		0x1000 /* Canonical Format Indicator */
#define VLAN_TAG_PRESENT	VLAN_CFI_MASK
#define VLAN_VID_MASK		0x0fff /* VLAN Identifier */
#define VLAN_N_VID		4096

/* found in socket.c */
extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));

static inline int is_vlan_dev(struct net_device *dev)
{
        return dev->priv_flags & IFF_802_1Q_VLAN;
}

#define vlan_tx_tag_present(__skb)	((__skb)->vlan_tci & VLAN_TAG_PRESENT)
#define vlan_tx_nonzero_tag_present(__skb) \
	(vlan_tx_tag_present(__skb) && ((__skb)->vlan_tci & VLAN_VID_MASK))
#define vlan_tx_tag_get(__skb)		((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)

#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)

extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
					       __be16 vlan_proto, u16 vlan_id);
extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
extern u16 vlan_dev_vlan_id(const struct net_device *dev);

extern bool vlan_do_receive(struct sk_buff **skb);
extern struct sk_buff *vlan_untag(struct sk_buff *skb);

extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);

extern int vlan_vids_add_by_dev(struct net_device *dev,
				const struct net_device *by_dev);
extern void vlan_vids_del_by_dev(struct net_device *dev,
				 const struct net_device *by_dev);

extern bool vlan_uses_dev(const struct net_device *dev);
#else
static inline struct net_device *
__vlan_find_dev_deep(struct net_device *real_dev,
		     __be16 vlan_proto, u16 vlan_id)
{
	return NULL;
}

static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
{
	BUG();
	return NULL;
}

static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
{
	BUG();
	return 0;
}

static inline bool vlan_do_receive(struct sk_buff **skb)
{
	return false;
}

static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
{
	return skb;
}

static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
{
	return 0;
}

static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
{
}

static inline int vlan_vids_add_by_dev(struct net_device *dev,
				       const struct net_device *by_dev)
{
	return 0;
}

static inline void vlan_vids_del_by_dev(struct net_device *dev,
					const struct net_device *by_dev)
{
}

static inline bool vlan_uses_dev(const struct net_device *dev)
{
	return false;
}
#endif

static inline bool vlan_hw_offload_capable(netdev_features_t features,
					   __be16 proto)
{
	if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
		return true;
	if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
		return true;
	return false;
}

/**
 * vlan_insert_tag - regular VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 *
 * Inserts the VLAN tag into @skb as part of the payload
 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 *
 * Following the skb_unshare() example, in case of error, the calling function
 * doesn't have to worry about freeing the original skb.
 *
 * Does not change skb->protocol so this function can be used during receive.
 */
static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
					      __be16 vlan_proto, u16 vlan_tci)
{
	struct vlan_ethhdr *veth;

	if (skb_cow_head(skb, VLAN_HLEN) < 0) {
		kfree_skb(skb);
		return NULL;
	}
	veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);

	/* Move the mac addresses to the beginning of the new header. */
	memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
	skb->mac_header -= VLAN_HLEN;

	/* first, the ethernet type */
	veth->h_vlan_proto = vlan_proto;

	/* now, the TCI */
	veth->h_vlan_TCI = htons(vlan_tci);

	return skb;
}

/**
 * __vlan_put_tag - regular VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_tci: VLAN TCI to insert
 *
 * Inserts the VLAN tag into @skb as part of the payload
 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 *
 * Following the skb_unshare() example, in case of error, the calling function
 * doesn't have to worry about freeing the original skb.
 */
static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb,
					     __be16 vlan_proto, u16 vlan_tci)
{
	skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
	if (skb)
		skb->protocol = vlan_proto;
	return skb;
}

/**
 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 * @skb: skbuff to tag
 * @vlan_proto: VLAN encapsulation protocol
 * @vlan_tci: VLAN TCI to insert
 *
 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 */
static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
						     __be16 vlan_proto,
						     u16 vlan_tci)
{
	skb->vlan_proto = vlan_proto;
	skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
	return skb;
}

/**
 * vlan_put_tag - inserts VLAN tag according to device features
 * @skb: skbuff to tag
 * @vlan_tci: VLAN TCI to insert
 *
 * Assumes skb->dev is the target that will xmit this frame.
 * Returns a VLAN tagged skb.
 */
static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb,
					   __be16 vlan_proto, u16 vlan_tci)
{
	if (vlan_hw_offload_capable(skb->dev->features, vlan_proto)) {
		return __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
	} else {
		return __vlan_put_tag(skb, vlan_proto, vlan_tci);
	}
}

/**
 * __vlan_get_tag - get the VLAN ID that is part of the payload
 * @skb: skbuff to query
 * @vlan_tci: buffer to store vlaue
 *
 * Returns error if the skb is not of VLAN type
 */
static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
{
	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;

	if (veth->h_vlan_proto != htons(ETH_P_8021Q) &&
	    veth->h_vlan_proto != htons(ETH_P_8021AD))
		return -EINVAL;

	*vlan_tci = ntohs(veth->h_vlan_TCI);
	return 0;
}

/**
 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 * @skb: skbuff to query
 * @vlan_tci: buffer to store vlaue
 *
 * Returns error if @skb->vlan_tci is not set correctly
 */
static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
					 u16 *vlan_tci)
{
	if (vlan_tx_tag_present(skb)) {
		*vlan_tci = vlan_tx_tag_get(skb);
		return 0;
	} else {
		*vlan_tci = 0;
		return -EINVAL;
	}
}

#define HAVE_VLAN_GET_TAG

/**
 * vlan_get_tag - get the VLAN ID from the skb
 * @skb: skbuff to query
 * @vlan_tci: buffer to store vlaue
 *
 * Returns error if the skb is not VLAN tagged
 */
static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
{
	if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
		return __vlan_hwaccel_get_tag(skb, vlan_tci);
	} else {
		return __vlan_get_tag(skb, vlan_tci);
	}
}

/**
 * vlan_get_protocol - get protocol EtherType.
 * @skb: skbuff to query
 *
 * Returns the EtherType of the packet, regardless of whether it is
 * vlan encapsulated (normal or hardware accelerated) or not.
 */
static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
{
	__be16 protocol = 0;

	if (vlan_tx_tag_present(skb) ||
	     skb->protocol != cpu_to_be16(ETH_P_8021Q))
		protocol = skb->protocol;
	else {
		__be16 proto, *protop;
		protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
						h_vlan_encapsulated_proto),
						sizeof(proto), &proto);
		if (likely(protop))
			protocol = *protop;
	}

	return protocol;
}

static inline void vlan_set_encap_proto(struct sk_buff *skb,
					struct vlan_hdr *vhdr)
{
	__be16 proto;
	unsigned short *rawp;

	/*
	 * Was a VLAN packet, grab the encapsulated protocol, which the layer
	 * three protocols care about.
	 */

	proto = vhdr->h_vlan_encapsulated_proto;
	if (ntohs(proto) >= ETH_P_802_3_MIN) {
		skb->protocol = proto;
		return;
	}

	rawp = (unsigned short *)(vhdr + 1);
	if (*rawp == 0xFFFF)
		/*
		 * This is a magic hack to spot IPX packets. Older Novell
		 * breaks the protocol design and runs IPX over 802.3 without
		 * an 802.2 LLC layer. We look for FFFF which isn't a used
		 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
		 * but does for the rest.
		 */
		skb->protocol = htons(ETH_P_802_3);
	else
		/*
		 * Real 802.2 LLC
		 */
		skb->protocol = htons(ETH_P_802_2);
}
#endif /* !(_LINUX_IF_VLAN_H_) */