1 /*
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 */
19 struct hlist_node;
20
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23
24 #define VLAN_HLEN 4 /* The additional bytes (on top of the Ethernet header)
25 * that VLAN requires.
26 */
27 #define VLAN_ETH_ALEN 6 /* Octets in one ethernet addr */
28 #define VLAN_ETH_HLEN 18 /* Total octets in header. */
29 #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
30
31 /*
32 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
33 */
34 #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
35 #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
36
37 /*
38 * struct vlan_hdr - vlan header
39 * @h_vlan_TCI: priority and VLAN ID
40 * @h_vlan_encapsulated_proto: packet type ID or len
41 */
42 struct vlan_hdr {
43 __be16 h_vlan_TCI;
44 __be16 h_vlan_encapsulated_proto;
45 };
46
47 /**
48 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
49 * @h_dest: destination ethernet address
50 * @h_source: source ethernet address
51 * @h_vlan_proto: ethernet protocol (always 0x8100)
52 * @h_vlan_TCI: priority and VLAN ID
53 * @h_vlan_encapsulated_proto: packet type ID or len
54 */
55 struct vlan_ethhdr {
56 unsigned char h_dest[ETH_ALEN];
57 unsigned char h_source[ETH_ALEN];
58 __be16 h_vlan_proto;
59 __be16 h_vlan_TCI;
60 __be16 h_vlan_encapsulated_proto;
61 };
62
63 #include <linux/skbuff.h>
64
65 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
66 {
67 return (struct vlan_ethhdr *)skb_mac_header(skb);
68 }
69
70 #define VLAN_VID_MASK 0xfff
71
72 /* found in socket.c */
73 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
74
75 /* if this changes, algorithm will have to be reworked because this
76 * depends on completely exhausting the VLAN identifier space. Thus
77 * it gives constant time look-up, but in many cases it wastes memory.
78 */
79 #define VLAN_GROUP_ARRAY_LEN 4096
80 #define VLAN_GROUP_ARRAY_SPLIT_PARTS 8
81 #define VLAN_GROUP_ARRAY_PART_LEN (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
82
83 struct vlan_group {
84 int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
85 unsigned int nr_vlans;
86 struct hlist_node hlist; /* linked list */
87 struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
88 struct rcu_head rcu;
89 };
90
91 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
92 unsigned int vlan_id)
93 {
94 struct net_device **array;
95 array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
96 return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN];
97 }
98
99 static inline void vlan_group_set_device(struct vlan_group *vg,
100 unsigned int vlan_id,
101 struct net_device *dev)
102 {
103 struct net_device **array;
104 if (!vg)
105 return;
106 array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
107 array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
108 }
109
110 struct vlan_priority_tci_mapping {
111 u32 priority;
112 unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
113 * at provisioning time.
114 * ((skb->priority << 13) & 0xE000)
115 */
116 struct vlan_priority_tci_mapping *next;
117 };
118
119 /* Holds information that makes sense if this device is a VLAN device. */
120 struct vlan_dev_info {
121 /** This will be the mapping that correlates skb->priority to
122 * 3 bits of VLAN QOS tags...
123 */
124 unsigned int nr_ingress_mappings;
125 u32 ingress_priority_map[8];
126
127 unsigned int nr_egress_mappings;
128 struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
129
130 unsigned short vlan_id; /* The VLAN Identifier for this interface. */
131 unsigned short flags; /* (1 << 0) re_order_header This option will cause the
132 * VLAN code to move around the ethernet header on
133 * ingress to make the skb look **exactly** like it
134 * came in from an ethernet port. This destroys some of
135 * the VLAN information in the skb, but it fixes programs
136 * like DHCP that use packet-filtering and don't understand
137 * 802.1Q
138 */
139 struct net_device *real_dev; /* the underlying device/interface */
140 unsigned char real_dev_addr[ETH_ALEN];
141 struct proc_dir_entry *dent; /* Holds the proc data */
142 unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
143 unsigned long cnt_encap_on_xmit; /* How many times did we have to encapsulate the skb on TX. */
144 };
145
146 static inline struct vlan_dev_info *vlan_dev_info(const struct net_device *dev)
147 {
148 return netdev_priv(dev);
149 }
150
151 /* inline functions */
152 static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
153 unsigned short vlan_tag)
154 {
155 struct vlan_dev_info *vip = vlan_dev_info(dev);
156
157 return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
158 }
159
160 /* VLAN tx hw acceleration helpers. */
161 struct vlan_skb_tx_cookie {
162 u32 magic;
163 u32 vlan_tag;
164 };
165
166 #define VLAN_TX_COOKIE_MAGIC 0x564c414e /* "VLAN" in ascii. */
167 #define VLAN_TX_SKB_CB(__skb) ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
168 #define vlan_tx_tag_present(__skb) \
169 (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
170 #define vlan_tx_tag_get(__skb) (VLAN_TX_SKB_CB(__skb)->vlan_tag)
171
172 /* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
173 static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
174 struct vlan_group *grp,
175 unsigned short vlan_tag, int polling)
176 {
177 struct net_device_stats *stats;
178
179 if (skb_bond_should_drop(skb)) {
180 dev_kfree_skb_any(skb);
181 return NET_RX_DROP;
182 }
183
184 skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);
185 if (skb->dev == NULL) {
186 dev_kfree_skb_any(skb);
187
188 /* Not NET_RX_DROP, this is not being dropped
189 * due to congestion.
190 */
191 return 0;
192 }
193
194 skb->dev->last_rx = jiffies;
195
196 stats = &skb->dev->stats;
197 stats->rx_packets++;
198 stats->rx_bytes += skb->len;
199
200 skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
201 switch (skb->pkt_type) {
202 case PACKET_BROADCAST:
203 break;
204
205 case PACKET_MULTICAST:
206 stats->multicast++;
207 break;
208
209 case PACKET_OTHERHOST:
210 /* Our lower layer thinks this is not local, let's make sure.
211 * This allows the VLAN to have a different MAC than the underlying
212 * device, and still route correctly.
213 */
214 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
215 skb->dev->dev_addr))
216 skb->pkt_type = PACKET_HOST;
217 break;
218 };
219
220 return (polling ? netif_receive_skb(skb) : netif_rx(skb));
221 }
222
223 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
224 struct vlan_group *grp,
225 unsigned short vlan_tag)
226 {
227 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
228 }
229
230 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
231 struct vlan_group *grp,
232 unsigned short vlan_tag)
233 {
234 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
235 }
236
237 /**
238 * __vlan_put_tag - regular VLAN tag inserting
239 * @skb: skbuff to tag
240 * @tag: VLAN tag to insert
241 *
242 * Inserts the VLAN tag into @skb as part of the payload
243 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
244 *
245 * Following the skb_unshare() example, in case of error, the calling function
246 * doesn't have to worry about freeing the original skb.
247 */
248 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
249 {
250 struct vlan_ethhdr *veth;
251
252 if (skb_headroom(skb) < VLAN_HLEN) {
253 struct sk_buff *sk_tmp = skb;
254 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
255 kfree_skb(sk_tmp);
256 if (!skb) {
257 printk(KERN_ERR "vlan: failed to realloc headroom\n");
258 return NULL;
259 }
260 } else {
261 skb = skb_unshare(skb, GFP_ATOMIC);
262 if (!skb) {
263 printk(KERN_ERR "vlan: failed to unshare skbuff\n");
264 return NULL;
265 }
266 }
267
268 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
269
270 /* Move the mac addresses to the beginning of the new header. */
271 memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
272
273 /* first, the ethernet type */
274 veth->h_vlan_proto = htons(ETH_P_8021Q);
275
276 /* now, the tag */
277 veth->h_vlan_TCI = htons(tag);
278
279 skb->protocol = htons(ETH_P_8021Q);
280 skb->mac_header -= VLAN_HLEN;
281 skb->network_header -= VLAN_HLEN;
282
283 return skb;
284 }
285
286 /**
287 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
288 * @skb: skbuff to tag
289 * @tag: VLAN tag to insert
290 *
291 * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
292 */
293 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
294 {
295 struct vlan_skb_tx_cookie *cookie;
296
297 cookie = VLAN_TX_SKB_CB(skb);
298 cookie->magic = VLAN_TX_COOKIE_MAGIC;
299 cookie->vlan_tag = tag;
300
301 return skb;
302 }
303
304 #define HAVE_VLAN_PUT_TAG
305
306 /**
307 * vlan_put_tag - inserts VLAN tag according to device features
308 * @skb: skbuff to tag
309 * @tag: VLAN tag to insert
310 *
311 * Assumes skb->dev is the target that will xmit this frame.
312 * Returns a VLAN tagged skb.
313 */
314 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
315 {
316 if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
317 return __vlan_hwaccel_put_tag(skb, tag);
318 } else {
319 return __vlan_put_tag(skb, tag);
320 }
321 }
322
323 /**
324 * __vlan_get_tag - get the VLAN ID that is part of the payload
325 * @skb: skbuff to query
326 * @tag: buffer to store vlaue
327 *
328 * Returns error if the skb is not of VLAN type
329 */
330 static inline int __vlan_get_tag(const struct sk_buff *skb, unsigned short *tag)
331 {
332 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
333
334 if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
335 return -EINVAL;
336 }
337
338 *tag = ntohs(veth->h_vlan_TCI);
339
340 return 0;
341 }
342
343 /**
344 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
345 * @skb: skbuff to query
346 * @tag: buffer to store vlaue
347 *
348 * Returns error if @skb->cb[] is not set correctly
349 */
350 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
351 unsigned short *tag)
352 {
353 struct vlan_skb_tx_cookie *cookie;
354
355 cookie = VLAN_TX_SKB_CB(skb);
356 if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
357 *tag = cookie->vlan_tag;
358 return 0;
359 } else {
360 *tag = 0;
361 return -EINVAL;
362 }
363 }
364
365 #define HAVE_VLAN_GET_TAG
366
367 /**
368 * vlan_get_tag - get the VLAN ID from the skb
369 * @skb: skbuff to query
370 * @tag: buffer to store vlaue
371 *
372 * Returns error if the skb is not VLAN tagged
373 */
374 static inline int vlan_get_tag(const struct sk_buff *skb, unsigned short *tag)
375 {
376 if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
377 return __vlan_hwaccel_get_tag(skb, tag);
378 } else {
379 return __vlan_get_tag(skb, tag);
380 }
381 }
382
383 #endif /* __KERNEL__ */
384
385 /* VLAN IOCTLs are found in sockios.h */
386
387 /* Passed in vlan_ioctl_args structure to determine behaviour. */
388 enum vlan_ioctl_cmds {
389 ADD_VLAN_CMD,
390 DEL_VLAN_CMD,
391 SET_VLAN_INGRESS_PRIORITY_CMD,
392 SET_VLAN_EGRESS_PRIORITY_CMD,
393 GET_VLAN_INGRESS_PRIORITY_CMD,
394 GET_VLAN_EGRESS_PRIORITY_CMD,
395 SET_VLAN_NAME_TYPE_CMD,
396 SET_VLAN_FLAG_CMD,
397 GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
398 GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
399 };
400
401 enum vlan_flags {
402 VLAN_FLAG_REORDER_HDR = 0x1,
403 };
404
405 enum vlan_name_types {
406 VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */
407 VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */
408 VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */
409 VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */
410 VLAN_NAME_TYPE_HIGHEST
411 };
412
413 struct vlan_ioctl_args {
414 int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
415 char device1[24];
416
417 union {
418 char device2[24];
419 int VID;
420 unsigned int skb_priority;
421 unsigned int name_type;
422 unsigned int bind_type;
423 unsigned int flag; /* Matches vlan_dev_info flags */
424 } u;
425
426 short vlan_qos;
427 };
428
429 #endif /* !(_LINUX_IF_VLAN_H_) */
430
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