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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
13#ifndef _LINUX_IF_VLAN_H_
14#define _LINUX_IF_VLAN_H_
15
16#ifdef __KERNEL__
17
18/* externally defined structs */
19struct vlan_group;
20struct net_device;
21struct packet_type;
22struct vlan_collection;
23struct vlan_dev_info;
24struct hlist_node;
25
26#include <linux/proc_fs.h> /* for proc_dir_entry */
27#include <linux/netdevice.h>
28
29#define VLAN_HLEN 4 /* The additional bytes (on top of the Ethernet header)
30 * that VLAN requires.
31 */
32#define VLAN_ETH_ALEN 6 /* Octets in one ethernet addr */
33#define VLAN_ETH_HLEN 18 /* Total octets in header. */
34#define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
35
36/*
37 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
38 */
39#define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
40#define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
41
42struct vlan_ethhdr {
43 unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
44 unsigned char h_source[ETH_ALEN]; /* source ether addr */
45 unsigned short h_vlan_proto; /* Should always be 0x8100 */
46 unsigned short h_vlan_TCI; /* Encapsulates priority and VLAN ID */
47 unsigned short h_vlan_encapsulated_proto; /* packet type ID field (or len) */
48};
49
50#include <linux/skbuff.h>
51
52static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
53{
54 return (struct vlan_ethhdr *)skb->mac.raw;
55}
56
57struct vlan_hdr {
58 unsigned short h_vlan_TCI; /* Encapsulates priority and VLAN ID */
59 unsigned short h_vlan_encapsulated_proto; /* packet type ID field (or len) */
60};
61
62#define VLAN_VID_MASK 0xfff
63
64/* found in socket.c */
65extern void vlan_ioctl_set(int (*hook)(void __user *));
66
67#define VLAN_NAME "vlan"
68
69/* if this changes, algorithm will have to be reworked because this
70 * depends on completely exhausting the VLAN identifier space. Thus
71 * it gives constant time look-up, but in many cases it wastes memory.
72 */
73#define VLAN_GROUP_ARRAY_LEN 4096
74
75struct vlan_group {
76 int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
77 struct hlist_node hlist; /* linked list */
78 struct net_device *vlan_devices[VLAN_GROUP_ARRAY_LEN];
79 struct rcu_head rcu;
80};
81
82struct vlan_priority_tci_mapping {
83 unsigned long priority;
84 unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
85 * at provisioning time.
86 * ((skb->priority << 13) & 0xE000)
87 */
88 struct vlan_priority_tci_mapping *next;
89};
90
91/* Holds information that makes sense if this device is a VLAN device. */
92struct vlan_dev_info {
93 /** This will be the mapping that correlates skb->priority to
94 * 3 bits of VLAN QOS tags...
95 */
96 unsigned long ingress_priority_map[8];
97 struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
98
99 unsigned short vlan_id; /* The VLAN Identifier for this interface. */
100 unsigned short flags; /* (1 << 0) re_order_header This option will cause the
101 * VLAN code to move around the ethernet header on
102 * ingress to make the skb look **exactly** like it
103 * came in from an ethernet port. This destroys some of
104 * the VLAN information in the skb, but it fixes programs
105 * like DHCP that use packet-filtering and don't understand
106 * 802.1Q
107 */
108 struct dev_mc_list *old_mc_list; /* old multi-cast list for the VLAN interface..
109 * we save this so we can tell what changes were
110 * made, in order to feed the right changes down
111 * to the real hardware...
112 */
113 int old_allmulti; /* similar to above. */
114 int old_promiscuity; /* similar to above. */
115 struct net_device *real_dev; /* the underlying device/interface */
116 struct proc_dir_entry *dent; /* Holds the proc data */
117 unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
118 unsigned long cnt_encap_on_xmit; /* How many times did we have to encapsulate the skb on TX. */
119 struct net_device_stats dev_stats; /* Device stats (rx-bytes, tx-pkts, etc...) */
120};
121
122#define VLAN_DEV_INFO(x) ((struct vlan_dev_info *)(x->priv))
123
124/* inline functions */
125
126static inline struct net_device_stats *vlan_dev_get_stats(struct net_device *dev)
127{
128 return &(VLAN_DEV_INFO(dev)->dev_stats);
129}
130
131static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
132 unsigned short vlan_tag)
133{
134 struct vlan_dev_info *vip = VLAN_DEV_INFO(dev);
135
136 return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
137}
138
139/* VLAN tx hw acceleration helpers. */
140struct vlan_skb_tx_cookie {
141 u32 magic;
142 u32 vlan_tag;
143};
144
145#define VLAN_TX_COOKIE_MAGIC 0x564c414e /* "VLAN" in ascii. */
146#define VLAN_TX_SKB_CB(__skb) ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
147#define vlan_tx_tag_present(__skb) \
148 (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
149#define vlan_tx_tag_get(__skb) (VLAN_TX_SKB_CB(__skb)->vlan_tag)
150
151/* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
152static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
153 struct vlan_group *grp,
154 unsigned short vlan_tag, int polling)
155{
156 struct net_device_stats *stats;
157
158 skb->real_dev = skb->dev;
159 skb->dev = grp->vlan_devices[vlan_tag & VLAN_VID_MASK];
160 if (skb->dev == NULL) {
161 dev_kfree_skb_any(skb);
162
163 /* Not NET_RX_DROP, this is not being dropped
164 * due to congestion.
165 */
166 return 0;
167 }
168
169 skb->dev->last_rx = jiffies;
170
171 stats = vlan_dev_get_stats(skb->dev);
172 stats->rx_packets++;
173 stats->rx_bytes += skb->len;
174
175 skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
176 switch (skb->pkt_type) {
177 case PACKET_BROADCAST:
178 break;
179
180 case PACKET_MULTICAST:
181 stats->multicast++;
182 break;
183
184 case PACKET_OTHERHOST:
185 /* Our lower layer thinks this is not local, let's make sure.
186 * This allows the VLAN to have a different MAC than the underlying
187 * device, and still route correctly.
188 */
189 if (!memcmp(eth_hdr(skb)->h_dest, skb->dev->dev_addr, ETH_ALEN))
190 skb->pkt_type = PACKET_HOST;
191 break;
192 };
193
194 return (polling ? netif_receive_skb(skb) : netif_rx(skb));
195}
196
197static inline int vlan_hwaccel_rx(struct sk_buff *skb,
198 struct vlan_group *grp,
199 unsigned short vlan_tag)
200{
201 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
202}
203
204static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
205 struct vlan_group *grp,
206 unsigned short vlan_tag)
207{
208 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
209}
210
211/**
212 * __vlan_put_tag - regular VLAN tag inserting
213 * @skb: skbuff to tag
214 * @tag: VLAN tag to insert
215 *
216 * Inserts the VLAN tag into @skb as part of the payload
217 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
218 *
219 * Following the skb_unshare() example, in case of error, the calling function
220 * doesn't have to worry about freeing the original skb.
221 */
222static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
223{
224 struct vlan_ethhdr *veth;
225
226 if (skb_headroom(skb) < VLAN_HLEN) {
227 struct sk_buff *sk_tmp = skb;
228 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
229 kfree_skb(sk_tmp);
230 if (!skb) {
231 printk(KERN_ERR "vlan: failed to realloc headroom\n");
232 return NULL;
233 }
234 } else {
235 skb = skb_unshare(skb, GFP_ATOMIC);
236 if (!skb) {
237 printk(KERN_ERR "vlan: failed to unshare skbuff\n");
238 return NULL;
239 }
240 }
241
242 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
243
244 /* Move the mac addresses to the beginning of the new header. */
245 memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
246
247 /* first, the ethernet type */
248 veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
249
250 /* now, the tag */
251 veth->h_vlan_TCI = htons(tag);
252
253 skb->protocol = __constant_htons(ETH_P_8021Q);
254 skb->mac.raw -= VLAN_HLEN;
255 skb->nh.raw -= VLAN_HLEN;
256
257 return skb;
258}
259
260/**
261 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
262 * @skb: skbuff to tag
263 * @tag: VLAN tag to insert
264 *
265 * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
266 */
267static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
268{
269 struct vlan_skb_tx_cookie *cookie;
270
271 cookie = VLAN_TX_SKB_CB(skb);
272 cookie->magic = VLAN_TX_COOKIE_MAGIC;
273 cookie->vlan_tag = tag;
274
275 return skb;
276}
277
278#define HAVE_VLAN_PUT_TAG
279
280/**
281 * vlan_put_tag - inserts VLAN tag according to device features
282 * @skb: skbuff to tag
283 * @tag: VLAN tag to insert
284 *
285 * Assumes skb->dev is the target that will xmit this frame.
286 * Returns a VLAN tagged skb.
287 */
288static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
289{
290 if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
291 return __vlan_hwaccel_put_tag(skb, tag);
292 } else {
293 return __vlan_put_tag(skb, tag);
294 }
295}
296
297/**
298 * __vlan_get_tag - get the VLAN ID that is part of the payload
299 * @skb: skbuff to query
300 * @tag: buffer to store vlaue
301 *
302 * Returns error if the skb is not of VLAN type
303 */
304static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
305{
306 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
307
308 if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
309 return -EINVAL;
310 }
311
312 *tag = ntohs(veth->h_vlan_TCI);
313
314 return 0;
315}
316
317/**
318 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
319 * @skb: skbuff to query
320 * @tag: buffer to store vlaue
321 *
322 * Returns error if @skb->cb[] is not set correctly
323 */
324static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag)
325{
326 struct vlan_skb_tx_cookie *cookie;
327
328 cookie = VLAN_TX_SKB_CB(skb);
329 if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
330 *tag = cookie->vlan_tag;
331 return 0;
332 } else {
333 *tag = 0;
334 return -EINVAL;
335 }
336}
337
338#define HAVE_VLAN_GET_TAG
339
340/**
341 * vlan_get_tag - get the VLAN ID from the skb
342 * @skb: skbuff to query
343 * @tag: buffer to store vlaue
344 *
345 * Returns error if the skb is not VLAN tagged
346 */
347static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
348{
349 if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
350 return __vlan_hwaccel_get_tag(skb, tag);
351 } else {
352 return __vlan_get_tag(skb, tag);
353 }
354}
355
356#endif /* __KERNEL__ */
357
358/* VLAN IOCTLs are found in sockios.h */
359
360/* Passed in vlan_ioctl_args structure to determine behaviour. */
361enum vlan_ioctl_cmds {
362 ADD_VLAN_CMD,
363 DEL_VLAN_CMD,
364 SET_VLAN_INGRESS_PRIORITY_CMD,
365 SET_VLAN_EGRESS_PRIORITY_CMD,
366 GET_VLAN_INGRESS_PRIORITY_CMD,
367 GET_VLAN_EGRESS_PRIORITY_CMD,
368 SET_VLAN_NAME_TYPE_CMD,
369 SET_VLAN_FLAG_CMD,
370 GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
371 GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
372};
373
374enum vlan_name_types {
375 VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */
376 VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */
377 VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */
378 VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */
379 VLAN_NAME_TYPE_HIGHEST
380};
381
382struct vlan_ioctl_args {
383 int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
384 char device1[24];
385
386 union {
387 char device2[24];
388 int VID;
389 unsigned int skb_priority;
390 unsigned int name_type;
391 unsigned int bind_type;
392 unsigned int flag; /* Matches vlan_dev_info flags */
393 } u;
394
395 short vlan_qos;
396};
397
398#endif /* !(_LINUX_IF_VLAN_H_) */