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