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 #ifndef _LINUX_IF_VLAN_H_
13 #define _LINUX_IF_VLAN_H_
14
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>
20
21 #define VLAN_HLEN 4 /* The additional bytes required by VLAN
22 * (in addition to the Ethernet header)
23 */
24 #define VLAN_ETH_HLEN 18 /* Total octets in header. */
25 #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
26
27 /*
28 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
29 */
30 #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
31 #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
32
33 #define VLAN_MAX_DEPTH 8 /* Max. number of nested VLAN tags parsed */
34
35 /*
36 * struct vlan_hdr - vlan header
37 * @h_vlan_TCI: priority and VLAN ID
38 * @h_vlan_encapsulated_proto: packet type ID or len
39 */
40 struct vlan_hdr {
41 __be16 h_vlan_TCI;
42 __be16 h_vlan_encapsulated_proto;
43 };
44
45 /**
46 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
47 * @h_dest: destination ethernet address
48 * @h_source: source ethernet address
49 * @h_vlan_proto: ethernet protocol
50 * @h_vlan_TCI: priority and VLAN ID
51 * @h_vlan_encapsulated_proto: packet type ID or len
52 */
53 struct vlan_ethhdr {
54 unsigned char h_dest[ETH_ALEN];
55 unsigned char h_source[ETH_ALEN];
56 __be16 h_vlan_proto;
57 __be16 h_vlan_TCI;
58 __be16 h_vlan_encapsulated_proto;
59 };
60
61 #include <linux/skbuff.h>
62
vlan_eth_hdr(const struct sk_buff * skb)63 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
64 {
65 return (struct vlan_ethhdr *)skb_mac_header(skb);
66 }
67
68 #define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
69 #define VLAN_PRIO_SHIFT 13
70 #define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */
71 #define VLAN_TAG_PRESENT VLAN_CFI_MASK
72 #define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
73 #define VLAN_N_VID 4096
74
75 /* found in socket.c */
76 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
77
is_vlan_dev(const struct net_device * dev)78 static inline bool is_vlan_dev(const struct net_device *dev)
79 {
80 return dev->priv_flags & IFF_802_1Q_VLAN;
81 }
82
83 #define skb_vlan_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
84 #define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
85 #define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK)
86 #define skb_vlan_tag_get_prio(__skb) ((__skb)->vlan_tci & VLAN_PRIO_MASK)
87
vlan_get_rx_ctag_filter_info(struct net_device * dev)88 static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
89 {
90 ASSERT_RTNL();
91 return notifier_to_errno(call_netdevice_notifiers(NETDEV_CVLAN_FILTER_PUSH_INFO, dev));
92 }
93
vlan_drop_rx_ctag_filter_info(struct net_device * dev)94 static inline void vlan_drop_rx_ctag_filter_info(struct net_device *dev)
95 {
96 ASSERT_RTNL();
97 call_netdevice_notifiers(NETDEV_CVLAN_FILTER_DROP_INFO, dev);
98 }
99
vlan_get_rx_stag_filter_info(struct net_device * dev)100 static inline int vlan_get_rx_stag_filter_info(struct net_device *dev)
101 {
102 ASSERT_RTNL();
103 return notifier_to_errno(call_netdevice_notifiers(NETDEV_SVLAN_FILTER_PUSH_INFO, dev));
104 }
105
vlan_drop_rx_stag_filter_info(struct net_device * dev)106 static inline void vlan_drop_rx_stag_filter_info(struct net_device *dev)
107 {
108 ASSERT_RTNL();
109 call_netdevice_notifiers(NETDEV_SVLAN_FILTER_DROP_INFO, dev);
110 }
111
112 /**
113 * struct vlan_pcpu_stats - VLAN percpu rx/tx stats
114 * @rx_packets: number of received packets
115 * @rx_bytes: number of received bytes
116 * @rx_multicast: number of received multicast packets
117 * @tx_packets: number of transmitted packets
118 * @tx_bytes: number of transmitted bytes
119 * @syncp: synchronization point for 64bit counters
120 * @rx_errors: number of rx errors
121 * @tx_dropped: number of tx drops
122 */
123 struct vlan_pcpu_stats {
124 u64 rx_packets;
125 u64 rx_bytes;
126 u64 rx_multicast;
127 u64 tx_packets;
128 u64 tx_bytes;
129 struct u64_stats_sync syncp;
130 u32 rx_errors;
131 u32 tx_dropped;
132 };
133
134 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
135
136 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
137 __be16 vlan_proto, u16 vlan_id);
138 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
139 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
140 extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
141
142 /**
143 * struct vlan_priority_tci_mapping - vlan egress priority mappings
144 * @priority: skb priority
145 * @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
146 * @next: pointer to next struct
147 */
148 struct vlan_priority_tci_mapping {
149 u32 priority;
150 u16 vlan_qos;
151 struct vlan_priority_tci_mapping *next;
152 };
153
154 struct proc_dir_entry;
155 struct netpoll;
156
157 /**
158 * struct vlan_dev_priv - VLAN private device data
159 * @nr_ingress_mappings: number of ingress priority mappings
160 * @ingress_priority_map: ingress priority mappings
161 * @nr_egress_mappings: number of egress priority mappings
162 * @egress_priority_map: hash of egress priority mappings
163 * @vlan_proto: VLAN encapsulation protocol
164 * @vlan_id: VLAN identifier
165 * @flags: device flags
166 * @real_dev: underlying netdevice
167 * @real_dev_addr: address of underlying netdevice
168 * @dent: proc dir entry
169 * @vlan_pcpu_stats: ptr to percpu rx stats
170 */
171 struct vlan_dev_priv {
172 unsigned int nr_ingress_mappings;
173 u32 ingress_priority_map[8];
174 unsigned int nr_egress_mappings;
175 struct vlan_priority_tci_mapping *egress_priority_map[16];
176
177 __be16 vlan_proto;
178 u16 vlan_id;
179 u16 flags;
180
181 struct net_device *real_dev;
182 unsigned char real_dev_addr[ETH_ALEN];
183
184 struct proc_dir_entry *dent;
185 struct vlan_pcpu_stats __percpu *vlan_pcpu_stats;
186 #ifdef CONFIG_NET_POLL_CONTROLLER
187 struct netpoll *netpoll;
188 #endif
189 unsigned int nest_level;
190 };
191
vlan_dev_priv(const struct net_device * dev)192 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
193 {
194 return netdev_priv(dev);
195 }
196
197 static inline u16
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)198 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
199 {
200 struct vlan_priority_tci_mapping *mp;
201
202 smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
203
204 mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
205 while (mp) {
206 if (mp->priority == skprio) {
207 return mp->vlan_qos; /* This should already be shifted
208 * to mask correctly with the
209 * VLAN's TCI */
210 }
211 mp = mp->next;
212 }
213 return 0;
214 }
215
216 extern bool vlan_do_receive(struct sk_buff **skb);
217
218 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
219 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
220
221 extern int vlan_vids_add_by_dev(struct net_device *dev,
222 const struct net_device *by_dev);
223 extern void vlan_vids_del_by_dev(struct net_device *dev,
224 const struct net_device *by_dev);
225
226 extern bool vlan_uses_dev(const struct net_device *dev);
227
vlan_get_encap_level(struct net_device * dev)228 static inline int vlan_get_encap_level(struct net_device *dev)
229 {
230 BUG_ON(!is_vlan_dev(dev));
231 return vlan_dev_priv(dev)->nest_level;
232 }
233 #else
234 static inline struct net_device *
__vlan_find_dev_deep_rcu(struct net_device * real_dev,__be16 vlan_proto,u16 vlan_id)235 __vlan_find_dev_deep_rcu(struct net_device *real_dev,
236 __be16 vlan_proto, u16 vlan_id)
237 {
238 return NULL;
239 }
240
vlan_dev_real_dev(const struct net_device * dev)241 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
242 {
243 BUG();
244 return NULL;
245 }
246
vlan_dev_vlan_id(const struct net_device * dev)247 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
248 {
249 BUG();
250 return 0;
251 }
252
vlan_dev_vlan_proto(const struct net_device * dev)253 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
254 {
255 BUG();
256 return 0;
257 }
258
vlan_dev_get_egress_qos_mask(struct net_device * dev,u32 skprio)259 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
260 u32 skprio)
261 {
262 return 0;
263 }
264
vlan_do_receive(struct sk_buff ** skb)265 static inline bool vlan_do_receive(struct sk_buff **skb)
266 {
267 return false;
268 }
269
vlan_vid_add(struct net_device * dev,__be16 proto,u16 vid)270 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
271 {
272 return 0;
273 }
274
vlan_vid_del(struct net_device * dev,__be16 proto,u16 vid)275 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
276 {
277 }
278
vlan_vids_add_by_dev(struct net_device * dev,const struct net_device * by_dev)279 static inline int vlan_vids_add_by_dev(struct net_device *dev,
280 const struct net_device *by_dev)
281 {
282 return 0;
283 }
284
vlan_vids_del_by_dev(struct net_device * dev,const struct net_device * by_dev)285 static inline void vlan_vids_del_by_dev(struct net_device *dev,
286 const struct net_device *by_dev)
287 {
288 }
289
vlan_uses_dev(const struct net_device * dev)290 static inline bool vlan_uses_dev(const struct net_device *dev)
291 {
292 return false;
293 }
vlan_get_encap_level(struct net_device * dev)294 static inline int vlan_get_encap_level(struct net_device *dev)
295 {
296 BUG();
297 return 0;
298 }
299 #endif
300
301 /**
302 * eth_type_vlan - check for valid vlan ether type.
303 * @ethertype: ether type to check
304 *
305 * Returns true if the ether type is a vlan ether type.
306 */
eth_type_vlan(__be16 ethertype)307 static inline bool eth_type_vlan(__be16 ethertype)
308 {
309 switch (ethertype) {
310 case htons(ETH_P_8021Q):
311 case htons(ETH_P_8021AD):
312 return true;
313 default:
314 return false;
315 }
316 }
317
vlan_hw_offload_capable(netdev_features_t features,__be16 proto)318 static inline bool vlan_hw_offload_capable(netdev_features_t features,
319 __be16 proto)
320 {
321 if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
322 return true;
323 if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
324 return true;
325 return false;
326 }
327
328 /**
329 * __vlan_insert_inner_tag - inner VLAN tag inserting
330 * @skb: skbuff to tag
331 * @vlan_proto: VLAN encapsulation protocol
332 * @vlan_tci: VLAN TCI to insert
333 * @mac_len: MAC header length including outer vlan headers
334 *
335 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
336 * Returns error if skb_cow_head fails.
337 *
338 * Does not change skb->protocol so this function can be used during receive.
339 */
__vlan_insert_inner_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci,unsigned int mac_len)340 static inline int __vlan_insert_inner_tag(struct sk_buff *skb,
341 __be16 vlan_proto, u16 vlan_tci,
342 unsigned int mac_len)
343 {
344 struct vlan_ethhdr *veth;
345
346 if (skb_cow_head(skb, VLAN_HLEN) < 0)
347 return -ENOMEM;
348
349 skb_push(skb, VLAN_HLEN);
350
351 /* Move the mac header sans proto to the beginning of the new header. */
352 if (likely(mac_len > ETH_TLEN))
353 memmove(skb->data, skb->data + VLAN_HLEN, mac_len - ETH_TLEN);
354 skb->mac_header -= VLAN_HLEN;
355
356 veth = (struct vlan_ethhdr *)(skb->data + mac_len - ETH_HLEN);
357
358 /* first, the ethernet type */
359 if (likely(mac_len >= ETH_TLEN)) {
360 /* h_vlan_encapsulated_proto should already be populated, and
361 * skb->data has space for h_vlan_proto
362 */
363 veth->h_vlan_proto = vlan_proto;
364 } else {
365 /* h_vlan_encapsulated_proto should not be populated, and
366 * skb->data has no space for h_vlan_proto
367 */
368 veth->h_vlan_encapsulated_proto = skb->protocol;
369 }
370
371 /* now, the TCI */
372 veth->h_vlan_TCI = htons(vlan_tci);
373
374 return 0;
375 }
376
377 /**
378 * __vlan_insert_tag - regular VLAN tag inserting
379 * @skb: skbuff to tag
380 * @vlan_proto: VLAN encapsulation protocol
381 * @vlan_tci: VLAN TCI to insert
382 *
383 * Inserts the VLAN tag into @skb as part of the payload
384 * Returns error if skb_cow_head fails.
385 *
386 * Does not change skb->protocol so this function can be used during receive.
387 */
__vlan_insert_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)388 static inline int __vlan_insert_tag(struct sk_buff *skb,
389 __be16 vlan_proto, u16 vlan_tci)
390 {
391 return __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
392 }
393
394 /**
395 * vlan_insert_inner_tag - inner VLAN tag inserting
396 * @skb: skbuff to tag
397 * @vlan_proto: VLAN encapsulation protocol
398 * @vlan_tci: VLAN TCI to insert
399 * @mac_len: MAC header length including outer vlan headers
400 *
401 * Inserts the VLAN tag into @skb as part of the payload at offset mac_len
402 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
403 *
404 * Following the skb_unshare() example, in case of error, the calling function
405 * doesn't have to worry about freeing the original skb.
406 *
407 * Does not change skb->protocol so this function can be used during receive.
408 */
vlan_insert_inner_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci,unsigned int mac_len)409 static inline struct sk_buff *vlan_insert_inner_tag(struct sk_buff *skb,
410 __be16 vlan_proto,
411 u16 vlan_tci,
412 unsigned int mac_len)
413 {
414 int err;
415
416 err = __vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, mac_len);
417 if (err) {
418 dev_kfree_skb_any(skb);
419 return NULL;
420 }
421 return skb;
422 }
423
424 /**
425 * vlan_insert_tag - regular VLAN tag inserting
426 * @skb: skbuff to tag
427 * @vlan_proto: VLAN encapsulation protocol
428 * @vlan_tci: VLAN TCI to insert
429 *
430 * Inserts the VLAN tag into @skb as part of the payload
431 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
432 *
433 * Following the skb_unshare() example, in case of error, the calling function
434 * doesn't have to worry about freeing the original skb.
435 *
436 * Does not change skb->protocol so this function can be used during receive.
437 */
vlan_insert_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)438 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
439 __be16 vlan_proto, u16 vlan_tci)
440 {
441 return vlan_insert_inner_tag(skb, vlan_proto, vlan_tci, ETH_HLEN);
442 }
443
444 /**
445 * vlan_insert_tag_set_proto - regular VLAN tag inserting
446 * @skb: skbuff to tag
447 * @vlan_proto: VLAN encapsulation protocol
448 * @vlan_tci: VLAN TCI to insert
449 *
450 * Inserts the VLAN tag into @skb as part of the payload
451 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
452 *
453 * Following the skb_unshare() example, in case of error, the calling function
454 * doesn't have to worry about freeing the original skb.
455 */
vlan_insert_tag_set_proto(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)456 static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
457 __be16 vlan_proto,
458 u16 vlan_tci)
459 {
460 skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
461 if (skb)
462 skb->protocol = vlan_proto;
463 return skb;
464 }
465
466 /*
467 * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
468 * @skb: skbuff to tag
469 *
470 * Pushes the VLAN tag from @skb->vlan_tci inside to the payload.
471 *
472 * Following the skb_unshare() example, in case of error, the calling function
473 * doesn't have to worry about freeing the original skb.
474 */
__vlan_hwaccel_push_inside(struct sk_buff * skb)475 static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
476 {
477 skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
478 skb_vlan_tag_get(skb));
479 if (likely(skb))
480 skb->vlan_tci = 0;
481 return skb;
482 }
483
484 /**
485 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
486 * @skb: skbuff to tag
487 * @vlan_proto: VLAN encapsulation protocol
488 * @vlan_tci: VLAN TCI to insert
489 *
490 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
491 */
__vlan_hwaccel_put_tag(struct sk_buff * skb,__be16 vlan_proto,u16 vlan_tci)492 static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
493 __be16 vlan_proto, u16 vlan_tci)
494 {
495 skb->vlan_proto = vlan_proto;
496 skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
497 }
498
499 /**
500 * __vlan_get_tag - get the VLAN ID that is part of the payload
501 * @skb: skbuff to query
502 * @vlan_tci: buffer to store value
503 *
504 * Returns error if the skb is not of VLAN type
505 */
__vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)506 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
507 {
508 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
509
510 if (!eth_type_vlan(veth->h_vlan_proto))
511 return -EINVAL;
512
513 *vlan_tci = ntohs(veth->h_vlan_TCI);
514 return 0;
515 }
516
517 /**
518 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
519 * @skb: skbuff to query
520 * @vlan_tci: buffer to store value
521 *
522 * Returns error if @skb->vlan_tci is not set correctly
523 */
__vlan_hwaccel_get_tag(const struct sk_buff * skb,u16 * vlan_tci)524 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
525 u16 *vlan_tci)
526 {
527 if (skb_vlan_tag_present(skb)) {
528 *vlan_tci = skb_vlan_tag_get(skb);
529 return 0;
530 } else {
531 *vlan_tci = 0;
532 return -EINVAL;
533 }
534 }
535
536 #define HAVE_VLAN_GET_TAG
537
538 /**
539 * vlan_get_tag - get the VLAN ID from the skb
540 * @skb: skbuff to query
541 * @vlan_tci: buffer to store value
542 *
543 * Returns error if the skb is not VLAN tagged
544 */
vlan_get_tag(const struct sk_buff * skb,u16 * vlan_tci)545 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
546 {
547 if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
548 return __vlan_hwaccel_get_tag(skb, vlan_tci);
549 } else {
550 return __vlan_get_tag(skb, vlan_tci);
551 }
552 }
553
554 /**
555 * vlan_get_protocol - get protocol EtherType.
556 * @skb: skbuff to query
557 * @type: first vlan protocol
558 * @depth: buffer to store length of eth and vlan tags in bytes
559 *
560 * Returns the EtherType of the packet, regardless of whether it is
561 * vlan encapsulated (normal or hardware accelerated) or not.
562 */
__vlan_get_protocol(const struct sk_buff * skb,__be16 type,int * depth)563 static inline __be16 __vlan_get_protocol(const struct sk_buff *skb, __be16 type,
564 int *depth)
565 {
566 unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH;
567
568 /* if type is 802.1Q/AD then the header should already be
569 * present at mac_len - VLAN_HLEN (if mac_len > 0), or at
570 * ETH_HLEN otherwise
571 */
572 if (eth_type_vlan(type)) {
573 if (vlan_depth) {
574 if (WARN_ON(vlan_depth < VLAN_HLEN))
575 return 0;
576 vlan_depth -= VLAN_HLEN;
577 } else {
578 vlan_depth = ETH_HLEN;
579 }
580 do {
581 struct vlan_hdr vhdr, *vh;
582
583 vh = skb_header_pointer(skb, vlan_depth, sizeof(vhdr), &vhdr);
584 if (unlikely(!vh || !--parse_depth))
585 return 0;
586
587 type = vh->h_vlan_encapsulated_proto;
588 vlan_depth += VLAN_HLEN;
589 } while (eth_type_vlan(type));
590 }
591
592 if (depth)
593 *depth = vlan_depth;
594
595 return type;
596 }
597
598 /**
599 * vlan_get_protocol - get protocol EtherType.
600 * @skb: skbuff to query
601 *
602 * Returns the EtherType of the packet, regardless of whether it is
603 * vlan encapsulated (normal or hardware accelerated) or not.
604 */
vlan_get_protocol(const struct sk_buff * skb)605 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
606 {
607 return __vlan_get_protocol(skb, skb->protocol, NULL);
608 }
609
610 /* A getter for the SKB protocol field which will handle VLAN tags consistently
611 * whether VLAN acceleration is enabled or not.
612 */
skb_protocol(const struct sk_buff * skb,bool skip_vlan)613 static inline __be16 skb_protocol(const struct sk_buff *skb, bool skip_vlan)
614 {
615 if (!skip_vlan)
616 /* VLAN acceleration strips the VLAN header from the skb and
617 * moves it to skb->vlan_proto
618 */
619 return skb_vlan_tag_present(skb) ? skb->vlan_proto : skb->protocol;
620
621 return vlan_get_protocol(skb);
622 }
623
vlan_set_encap_proto(struct sk_buff * skb,struct vlan_hdr * vhdr)624 static inline void vlan_set_encap_proto(struct sk_buff *skb,
625 struct vlan_hdr *vhdr)
626 {
627 __be16 proto;
628 unsigned short *rawp;
629
630 /*
631 * Was a VLAN packet, grab the encapsulated protocol, which the layer
632 * three protocols care about.
633 */
634
635 proto = vhdr->h_vlan_encapsulated_proto;
636 if (eth_proto_is_802_3(proto)) {
637 skb->protocol = proto;
638 return;
639 }
640
641 rawp = (unsigned short *)(vhdr + 1);
642 if (*rawp == 0xFFFF)
643 /*
644 * This is a magic hack to spot IPX packets. Older Novell
645 * breaks the protocol design and runs IPX over 802.3 without
646 * an 802.2 LLC layer. We look for FFFF which isn't a used
647 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
648 * but does for the rest.
649 */
650 skb->protocol = htons(ETH_P_802_3);
651 else
652 /*
653 * Real 802.2 LLC
654 */
655 skb->protocol = htons(ETH_P_802_2);
656 }
657
658 /**
659 * skb_vlan_tagged - check if skb is vlan tagged.
660 * @skb: skbuff to query
661 *
662 * Returns true if the skb is tagged, regardless of whether it is hardware
663 * accelerated or not.
664 */
skb_vlan_tagged(const struct sk_buff * skb)665 static inline bool skb_vlan_tagged(const struct sk_buff *skb)
666 {
667 if (!skb_vlan_tag_present(skb) &&
668 likely(!eth_type_vlan(skb->protocol)))
669 return false;
670
671 return true;
672 }
673
674 /**
675 * skb_vlan_tagged_multi - check if skb is vlan tagged with multiple headers.
676 * @skb: skbuff to query
677 *
678 * Returns true if the skb is tagged with multiple vlan headers, regardless
679 * of whether it is hardware accelerated or not.
680 */
skb_vlan_tagged_multi(struct sk_buff * skb)681 static inline bool skb_vlan_tagged_multi(struct sk_buff *skb)
682 {
683 __be16 protocol = skb->protocol;
684
685 if (!skb_vlan_tag_present(skb)) {
686 struct vlan_ethhdr *veh;
687
688 if (likely(!eth_type_vlan(protocol)))
689 return false;
690
691 if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
692 return false;
693
694 veh = (struct vlan_ethhdr *)skb->data;
695 protocol = veh->h_vlan_encapsulated_proto;
696 }
697
698 if (!eth_type_vlan(protocol))
699 return false;
700
701 return true;
702 }
703
704 /**
705 * vlan_features_check - drop unsafe features for skb with multiple tags.
706 * @skb: skbuff to query
707 * @features: features to be checked
708 *
709 * Returns features without unsafe ones if the skb has multiple tags.
710 */
vlan_features_check(struct sk_buff * skb,netdev_features_t features)711 static inline netdev_features_t vlan_features_check(struct sk_buff *skb,
712 netdev_features_t features)
713 {
714 if (skb_vlan_tagged_multi(skb)) {
715 /* In the case of multi-tagged packets, use a direct mask
716 * instead of using netdev_interesect_features(), to make
717 * sure that only devices supporting NETIF_F_HW_CSUM will
718 * have checksum offloading support.
719 */
720 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_HW_CSUM |
721 NETIF_F_FRAGLIST | NETIF_F_HW_VLAN_CTAG_TX |
722 NETIF_F_HW_VLAN_STAG_TX;
723 }
724
725 return features;
726 }
727
728 /**
729 * compare_vlan_header - Compare two vlan headers
730 * @h1: Pointer to vlan header
731 * @h2: Pointer to vlan header
732 *
733 * Compare two vlan headers, returns 0 if equal.
734 *
735 * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
736 */
compare_vlan_header(const struct vlan_hdr * h1,const struct vlan_hdr * h2)737 static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
738 const struct vlan_hdr *h2)
739 {
740 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
741 return *(u32 *)h1 ^ *(u32 *)h2;
742 #else
743 return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
744 ((__force u32)h1->h_vlan_encapsulated_proto ^
745 (__force u32)h2->h_vlan_encapsulated_proto);
746 #endif
747 }
748 #endif /* !(_LINUX_IF_VLAN_H_) */
749