2 * VLAN An implementation of 802.1Q VLAN tagging.
4 * Authors: Ben Greear <greearb@candelatech.com>
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.
12 #ifndef _LINUX_IF_VLAN_H_
13 #define _LINUX_IF_VLAN_H_
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>
21 #define VLAN_HLEN 4 /* The additional bytes required by VLAN
22 * (in addition to the Ethernet header)
24 #define VLAN_ETH_HLEN 18 /* Total octets in header. */
25 #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
28 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
30 #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
31 #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
34 * struct vlan_hdr - vlan header
35 * @h_vlan_TCI: priority and VLAN ID
36 * @h_vlan_encapsulated_proto: packet type ID or len
40 __be16 h_vlan_encapsulated_proto
;
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
52 unsigned char h_dest
[ETH_ALEN
];
53 unsigned char h_source
[ETH_ALEN
];
56 __be16 h_vlan_encapsulated_proto
;
59 #include <linux/skbuff.h>
61 static inline struct vlan_ethhdr
*vlan_eth_hdr(const struct sk_buff
*skb
)
63 return (struct vlan_ethhdr
*)skb_mac_header(skb
);
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
73 /* found in socket.c */
74 extern void vlan_ioctl_set(int (*hook
)(struct net
*, void __user
*));
76 static inline int is_vlan_dev(struct net_device
*dev
)
78 return dev
->priv_flags
& IFF_802_1Q_VLAN
;
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)
85 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
87 extern struct net_device
*__vlan_find_dev_deep(struct net_device
*real_dev
,
88 __be16 vlan_proto
, u16 vlan_id
);
89 extern struct net_device
*vlan_dev_real_dev(const struct net_device
*dev
);
90 extern u16
vlan_dev_vlan_id(const struct net_device
*dev
);
92 extern bool vlan_do_receive(struct sk_buff
**skb
);
93 extern struct sk_buff
*vlan_untag(struct sk_buff
*skb
);
95 extern int vlan_vid_add(struct net_device
*dev
, __be16 proto
, u16 vid
);
96 extern void vlan_vid_del(struct net_device
*dev
, __be16 proto
, u16 vid
);
98 extern int vlan_vids_add_by_dev(struct net_device
*dev
,
99 const struct net_device
*by_dev
);
100 extern void vlan_vids_del_by_dev(struct net_device
*dev
,
101 const struct net_device
*by_dev
);
103 extern bool vlan_uses_dev(const struct net_device
*dev
);
105 static inline struct net_device
*
106 __vlan_find_dev_deep(struct net_device
*real_dev
,
107 __be16 vlan_proto
, u16 vlan_id
)
112 static inline struct net_device
*vlan_dev_real_dev(const struct net_device
*dev
)
118 static inline u16
vlan_dev_vlan_id(const struct net_device
*dev
)
124 static inline bool vlan_do_receive(struct sk_buff
**skb
)
129 static inline struct sk_buff
*vlan_untag(struct sk_buff
*skb
)
134 static inline int vlan_vid_add(struct net_device
*dev
, __be16 proto
, u16 vid
)
139 static inline void vlan_vid_del(struct net_device
*dev
, __be16 proto
, u16 vid
)
143 static inline int vlan_vids_add_by_dev(struct net_device
*dev
,
144 const struct net_device
*by_dev
)
149 static inline void vlan_vids_del_by_dev(struct net_device
*dev
,
150 const struct net_device
*by_dev
)
154 static inline bool vlan_uses_dev(const struct net_device
*dev
)
160 static inline bool vlan_hw_offload_capable(netdev_features_t features
,
163 if (proto
== htons(ETH_P_8021Q
) && features
& NETIF_F_HW_VLAN_CTAG_TX
)
165 if (proto
== htons(ETH_P_8021AD
) && features
& NETIF_F_HW_VLAN_STAG_TX
)
171 * vlan_insert_tag - regular VLAN tag inserting
172 * @skb: skbuff to tag
173 * @vlan_proto: VLAN encapsulation protocol
174 * @vlan_tci: VLAN TCI to insert
176 * Inserts the VLAN tag into @skb as part of the payload
177 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
179 * Following the skb_unshare() example, in case of error, the calling function
180 * doesn't have to worry about freeing the original skb.
182 * Does not change skb->protocol so this function can be used during receive.
184 static inline struct sk_buff
*vlan_insert_tag(struct sk_buff
*skb
,
185 __be16 vlan_proto
, u16 vlan_tci
)
187 struct vlan_ethhdr
*veth
;
189 if (skb_cow_head(skb
, VLAN_HLEN
) < 0) {
193 veth
= (struct vlan_ethhdr
*)skb_push(skb
, VLAN_HLEN
);
195 /* Move the mac addresses to the beginning of the new header. */
196 memmove(skb
->data
, skb
->data
+ VLAN_HLEN
, 2 * ETH_ALEN
);
197 skb
->mac_header
-= VLAN_HLEN
;
199 /* first, the ethernet type */
200 veth
->h_vlan_proto
= vlan_proto
;
203 veth
->h_vlan_TCI
= htons(vlan_tci
);
209 * __vlan_put_tag - regular VLAN tag inserting
210 * @skb: skbuff to tag
211 * @vlan_tci: VLAN TCI to insert
213 * Inserts the VLAN tag into @skb as part of the payload
214 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
216 * Following the skb_unshare() example, in case of error, the calling function
217 * doesn't have to worry about freeing the original skb.
219 static inline struct sk_buff
*__vlan_put_tag(struct sk_buff
*skb
,
220 __be16 vlan_proto
, u16 vlan_tci
)
222 skb
= vlan_insert_tag(skb
, vlan_proto
, vlan_tci
);
224 skb
->protocol
= vlan_proto
;
229 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
230 * @skb: skbuff to tag
231 * @vlan_proto: VLAN encapsulation protocol
232 * @vlan_tci: VLAN TCI to insert
234 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
236 static inline struct sk_buff
*__vlan_hwaccel_put_tag(struct sk_buff
*skb
,
240 skb
->vlan_proto
= vlan_proto
;
241 skb
->vlan_tci
= VLAN_TAG_PRESENT
| vlan_tci
;
246 * vlan_put_tag - inserts VLAN tag according to device features
247 * @skb: skbuff to tag
248 * @vlan_tci: VLAN TCI to insert
250 * Assumes skb->dev is the target that will xmit this frame.
251 * Returns a VLAN tagged skb.
253 static inline struct sk_buff
*vlan_put_tag(struct sk_buff
*skb
,
254 __be16 vlan_proto
, u16 vlan_tci
)
256 if (vlan_hw_offload_capable(skb
->dev
->features
, vlan_proto
)) {
257 return __vlan_hwaccel_put_tag(skb
, vlan_proto
, vlan_tci
);
259 return __vlan_put_tag(skb
, vlan_proto
, vlan_tci
);
264 * __vlan_get_tag - get the VLAN ID that is part of the payload
265 * @skb: skbuff to query
266 * @vlan_tci: buffer to store vlaue
268 * Returns error if the skb is not of VLAN type
270 static inline int __vlan_get_tag(const struct sk_buff
*skb
, u16
*vlan_tci
)
272 struct vlan_ethhdr
*veth
= (struct vlan_ethhdr
*)skb
->data
;
274 if (veth
->h_vlan_proto
!= htons(ETH_P_8021Q
) &&
275 veth
->h_vlan_proto
!= htons(ETH_P_8021AD
))
278 *vlan_tci
= ntohs(veth
->h_vlan_TCI
);
283 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
284 * @skb: skbuff to query
285 * @vlan_tci: buffer to store vlaue
287 * Returns error if @skb->vlan_tci is not set correctly
289 static inline int __vlan_hwaccel_get_tag(const struct sk_buff
*skb
,
292 if (vlan_tx_tag_present(skb
)) {
293 *vlan_tci
= vlan_tx_tag_get(skb
);
301 #define HAVE_VLAN_GET_TAG
304 * vlan_get_tag - get the VLAN ID from the skb
305 * @skb: skbuff to query
306 * @vlan_tci: buffer to store vlaue
308 * Returns error if the skb is not VLAN tagged
310 static inline int vlan_get_tag(const struct sk_buff
*skb
, u16
*vlan_tci
)
312 if (skb
->dev
->features
& NETIF_F_HW_VLAN_CTAG_TX
) {
313 return __vlan_hwaccel_get_tag(skb
, vlan_tci
);
315 return __vlan_get_tag(skb
, vlan_tci
);
320 * vlan_get_protocol - get protocol EtherType.
321 * @skb: skbuff to query
323 * Returns the EtherType of the packet, regardless of whether it is
324 * vlan encapsulated (normal or hardware accelerated) or not.
326 static inline __be16
vlan_get_protocol(const struct sk_buff
*skb
)
330 if (vlan_tx_tag_present(skb
) ||
331 skb
->protocol
!= cpu_to_be16(ETH_P_8021Q
))
332 protocol
= skb
->protocol
;
334 __be16 proto
, *protop
;
335 protop
= skb_header_pointer(skb
, offsetof(struct vlan_ethhdr
,
336 h_vlan_encapsulated_proto
),
337 sizeof(proto
), &proto
);
345 static inline void vlan_set_encap_proto(struct sk_buff
*skb
,
346 struct vlan_hdr
*vhdr
)
349 unsigned short *rawp
;
352 * Was a VLAN packet, grab the encapsulated protocol, which the layer
353 * three protocols care about.
356 proto
= vhdr
->h_vlan_encapsulated_proto
;
357 if (ntohs(proto
) >= ETH_P_802_3_MIN
) {
358 skb
->protocol
= proto
;
362 rawp
= (unsigned short *)(vhdr
+ 1);
365 * This is a magic hack to spot IPX packets. Older Novell
366 * breaks the protocol design and runs IPX over 802.3 without
367 * an 802.2 LLC layer. We look for FFFF which isn't a used
368 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
369 * but does for the rest.
371 skb
->protocol
= htons(ETH_P_802_3
);
376 skb
->protocol
= htons(ETH_P_802_2
);
378 #endif /* !(_LINUX_IF_VLAN_H_) */