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);
91 extern u16 vlan_dev_get_egress_qos_mask(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,
108 __be16 vlan_proto, u16 vlan_id)
113 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
119 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
125 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
131 static inline bool vlan_do_receive(struct sk_buff **skb)
136 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
141 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
146 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
150 static inline int vlan_vids_add_by_dev(struct net_device *dev,
151 const struct net_device *by_dev)
156 static inline void vlan_vids_del_by_dev(struct net_device *dev,
157 const struct net_device *by_dev)
161 static inline bool vlan_uses_dev(const struct net_device *dev)
167 static inline bool vlan_hw_offload_capable(netdev_features_t features,
170 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
172 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
178 * vlan_insert_tag - regular VLAN tag inserting
179 * @skb: skbuff to tag
180 * @vlan_proto: VLAN encapsulation protocol
181 * @vlan_tci: VLAN TCI to insert
183 * Inserts the VLAN tag into @skb as part of the payload
184 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
186 * Following the skb_unshare() example, in case of error, the calling function
187 * doesn't have to worry about freeing the original skb.
189 * Does not change skb->protocol so this function can be used during receive.
191 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
192 __be16 vlan_proto, u16 vlan_tci)
194 struct vlan_ethhdr *veth;
196 if (skb_cow_head(skb, VLAN_HLEN) < 0) {
200 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
202 /* Move the mac addresses to the beginning of the new header. */
203 memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
204 skb->mac_header -= VLAN_HLEN;
206 /* first, the ethernet type */
207 veth->h_vlan_proto = vlan_proto;
210 veth->h_vlan_TCI = htons(vlan_tci);
216 * __vlan_put_tag - regular VLAN tag inserting
217 * @skb: skbuff to tag
218 * @vlan_tci: VLAN TCI to insert
220 * Inserts the VLAN tag into @skb as part of the payload
221 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
223 * Following the skb_unshare() example, in case of error, the calling function
224 * doesn't have to worry about freeing the original skb.
226 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb,
227 __be16 vlan_proto, u16 vlan_tci)
229 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
231 skb->protocol = vlan_proto;
236 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
237 * @skb: skbuff to tag
238 * @vlan_proto: VLAN encapsulation protocol
239 * @vlan_tci: VLAN TCI to insert
241 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
243 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
247 skb->vlan_proto = vlan_proto;
248 skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
253 * vlan_put_tag - inserts VLAN tag according to device features
254 * @skb: skbuff to tag
255 * @vlan_tci: VLAN TCI to insert
257 * Assumes skb->dev is the target that will xmit this frame.
258 * Returns a VLAN tagged skb.
260 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb,
261 __be16 vlan_proto, u16 vlan_tci)
263 if (vlan_hw_offload_capable(skb->dev->features, vlan_proto)) {
264 return __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
266 return __vlan_put_tag(skb, vlan_proto, vlan_tci);
271 * __vlan_get_tag - get the VLAN ID that is part of the payload
272 * @skb: skbuff to query
273 * @vlan_tci: buffer to store vlaue
275 * Returns error if the skb is not of VLAN type
277 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
279 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
281 if (veth->h_vlan_proto != htons(ETH_P_8021Q) &&
282 veth->h_vlan_proto != htons(ETH_P_8021AD))
285 *vlan_tci = ntohs(veth->h_vlan_TCI);
290 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
291 * @skb: skbuff to query
292 * @vlan_tci: buffer to store vlaue
294 * Returns error if @skb->vlan_tci is not set correctly
296 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
299 if (vlan_tx_tag_present(skb)) {
300 *vlan_tci = vlan_tx_tag_get(skb);
308 #define HAVE_VLAN_GET_TAG
311 * vlan_get_tag - get the VLAN ID from the skb
312 * @skb: skbuff to query
313 * @vlan_tci: buffer to store vlaue
315 * Returns error if the skb is not VLAN tagged
317 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
319 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
320 return __vlan_hwaccel_get_tag(skb, vlan_tci);
322 return __vlan_get_tag(skb, vlan_tci);
327 * vlan_get_protocol - get protocol EtherType.
328 * @skb: skbuff to query
330 * Returns the EtherType of the packet, regardless of whether it is
331 * vlan encapsulated (normal or hardware accelerated) or not.
333 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
337 if (vlan_tx_tag_present(skb) ||
338 skb->protocol != cpu_to_be16(ETH_P_8021Q))
339 protocol = skb->protocol;
341 __be16 proto, *protop;
342 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
343 h_vlan_encapsulated_proto),
344 sizeof(proto), &proto);
352 static inline void vlan_set_encap_proto(struct sk_buff *skb,
353 struct vlan_hdr *vhdr)
356 unsigned short *rawp;
359 * Was a VLAN packet, grab the encapsulated protocol, which the layer
360 * three protocols care about.
363 proto = vhdr->h_vlan_encapsulated_proto;
364 if (ntohs(proto) >= ETH_P_802_3_MIN) {
365 skb->protocol = proto;
369 rawp = (unsigned short *)(vhdr + 1);
372 * This is a magic hack to spot IPX packets. Older Novell
373 * breaks the protocol design and runs IPX over 802.3 without
374 * an 802.2 LLC layer. We look for FFFF which isn't a used
375 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
376 * but does for the rest.
378 skb->protocol = htons(ETH_P_802_3);
383 skb->protocol = htons(ETH_P_802_2);
385 #endif /* !(_LINUX_IF_VLAN_H_) */