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 (always 0x8100)
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_nonzero_tag_present(__skb) \
83 (vlan_tx_tag_present(__skb) && ((__skb)->vlan_tci & VLAN_VID_MASK))
84 #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
86 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
88 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
89 __be16 vlan_proto, u16 vlan_id);
90 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
91 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
93 extern bool vlan_do_receive(struct sk_buff **skb);
94 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
96 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
97 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
99 extern int vlan_vids_add_by_dev(struct net_device *dev,
100 const struct net_device *by_dev);
101 extern void vlan_vids_del_by_dev(struct net_device *dev,
102 const struct net_device *by_dev);
104 extern bool vlan_uses_dev(const struct net_device *dev);
106 static inline struct net_device *
107 __vlan_find_dev_deep(struct net_device *real_dev, 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, unsigned short vid)
139 static inline void vlan_vid_del(struct net_device *dev, unsigned short 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;
245 #define HAVE_VLAN_PUT_TAG
248 * vlan_put_tag - inserts VLAN tag according to device features
249 * @skb: skbuff to tag
250 * @vlan_tci: VLAN TCI to insert
252 * Assumes skb->dev is the target that will xmit this frame.
253 * Returns a VLAN tagged skb.
255 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb,
256 __be16 vlan_proto, u16 vlan_tci)
258 if (vlan_hw_offload_capable(skb->dev->features, vlan_proto)) {
259 return __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
261 return __vlan_put_tag(skb, vlan_proto, vlan_tci);
266 * __vlan_get_tag - get the VLAN ID that is part of the payload
267 * @skb: skbuff to query
268 * @vlan_tci: buffer to store vlaue
270 * Returns error if the skb is not of VLAN type
272 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
274 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
276 if (veth->h_vlan_proto != htons(ETH_P_8021Q) &&
277 veth->h_vlan_proto != htons(ETH_P_8021AD))
280 *vlan_tci = ntohs(veth->h_vlan_TCI);
285 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
286 * @skb: skbuff to query
287 * @vlan_tci: buffer to store vlaue
289 * Returns error if @skb->vlan_tci is not set correctly
291 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
294 if (vlan_tx_tag_present(skb)) {
295 *vlan_tci = vlan_tx_tag_get(skb);
303 #define HAVE_VLAN_GET_TAG
306 * vlan_get_tag - get the VLAN ID from the skb
307 * @skb: skbuff to query
308 * @vlan_tci: buffer to store vlaue
310 * Returns error if the skb is not VLAN tagged
312 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
314 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
315 return __vlan_hwaccel_get_tag(skb, vlan_tci);
317 return __vlan_get_tag(skb, vlan_tci);
322 * vlan_get_protocol - get protocol EtherType.
323 * @skb: skbuff to query
325 * Returns the EtherType of the packet, regardless of whether it is
326 * vlan encapsulated (normal or hardware accelerated) or not.
328 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
332 if (vlan_tx_tag_present(skb) ||
333 skb->protocol != cpu_to_be16(ETH_P_8021Q))
334 protocol = skb->protocol;
336 __be16 proto, *protop;
337 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
338 h_vlan_encapsulated_proto),
339 sizeof(proto), &proto);
347 static inline void vlan_set_encap_proto(struct sk_buff *skb,
348 struct vlan_hdr *vhdr)
351 unsigned short *rawp;
354 * Was a VLAN packet, grab the encapsulated protocol, which the layer
355 * three protocols care about.
358 proto = vhdr->h_vlan_encapsulated_proto;
359 if (ntohs(proto) >= ETH_P_802_3_MIN) {
360 skb->protocol = proto;
364 rawp = (unsigned short *)(vhdr + 1);
367 * This is a magic hack to spot IPX packets. Older Novell
368 * breaks the protocol design and runs IPX over 802.3 without
369 * an 802.2 LLC layer. We look for FFFF which isn't a used
370 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
371 * but does for the rest.
373 skb->protocol = htons(ETH_P_802_3);
378 skb->protocol = htons(ETH_P_802_2);
380 #endif /* !(_LINUX_IF_VLAN_H_) */