xref: /linux/net/8021q/vlan_core.c (revision 3c4fc7bf4c9e66fe71abcbf93f62f4ddb89b7f15)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/skbuff.h>
3 #include <linux/netdevice.h>
4 #include <linux/if_vlan.h>
5 #include <linux/netpoll.h>
6 #include <linux/export.h>
7 #include <net/gro.h>
8 #include "vlan.h"
9 
10 bool vlan_do_receive(struct sk_buff **skbp)
11 {
12 	struct sk_buff *skb = *skbp;
13 	__be16 vlan_proto = skb->vlan_proto;
14 	u16 vlan_id = skb_vlan_tag_get_id(skb);
15 	struct net_device *vlan_dev;
16 	struct vlan_pcpu_stats *rx_stats;
17 
18 	vlan_dev = vlan_find_dev(skb->dev, vlan_proto, vlan_id);
19 	if (!vlan_dev)
20 		return false;
21 
22 	skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
23 	if (unlikely(!skb))
24 		return false;
25 
26 	if (unlikely(!(vlan_dev->flags & IFF_UP))) {
27 		kfree_skb(skb);
28 		*skbp = NULL;
29 		return false;
30 	}
31 
32 	skb->dev = vlan_dev;
33 	if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
34 		/* Our lower layer thinks this is not local, let's make sure.
35 		 * This allows the VLAN to have a different MAC than the
36 		 * underlying device, and still route correctly. */
37 		if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
38 			skb->pkt_type = PACKET_HOST;
39 	}
40 
41 	if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR) &&
42 	    !netif_is_macvlan_port(vlan_dev) &&
43 	    !netif_is_bridge_port(vlan_dev)) {
44 		unsigned int offset = skb->data - skb_mac_header(skb);
45 
46 		/*
47 		 * vlan_insert_tag expect skb->data pointing to mac header.
48 		 * So change skb->data before calling it and change back to
49 		 * original position later
50 		 */
51 		skb_push(skb, offset);
52 		skb = *skbp = vlan_insert_inner_tag(skb, skb->vlan_proto,
53 						    skb->vlan_tci, skb->mac_len);
54 		if (!skb)
55 			return false;
56 		skb_pull(skb, offset + VLAN_HLEN);
57 		skb_reset_mac_len(skb);
58 	}
59 
60 	skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
61 	__vlan_hwaccel_clear_tag(skb);
62 
63 	rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
64 
65 	u64_stats_update_begin(&rx_stats->syncp);
66 	u64_stats_inc(&rx_stats->rx_packets);
67 	u64_stats_add(&rx_stats->rx_bytes, skb->len);
68 	if (skb->pkt_type == PACKET_MULTICAST)
69 		u64_stats_inc(&rx_stats->rx_multicast);
70 	u64_stats_update_end(&rx_stats->syncp);
71 
72 	return true;
73 }
74 
75 /* Must be invoked with rcu_read_lock. */
76 struct net_device *__vlan_find_dev_deep_rcu(struct net_device *dev,
77 					__be16 vlan_proto, u16 vlan_id)
78 {
79 	struct vlan_info *vlan_info = rcu_dereference(dev->vlan_info);
80 
81 	if (vlan_info) {
82 		return vlan_group_get_device(&vlan_info->grp,
83 					     vlan_proto, vlan_id);
84 	} else {
85 		/*
86 		 * Lower devices of master uppers (bonding, team) do not have
87 		 * grp assigned to themselves. Grp is assigned to upper device
88 		 * instead.
89 		 */
90 		struct net_device *upper_dev;
91 
92 		upper_dev = netdev_master_upper_dev_get_rcu(dev);
93 		if (upper_dev)
94 			return __vlan_find_dev_deep_rcu(upper_dev,
95 						    vlan_proto, vlan_id);
96 	}
97 
98 	return NULL;
99 }
100 EXPORT_SYMBOL(__vlan_find_dev_deep_rcu);
101 
102 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
103 {
104 	struct net_device *ret = vlan_dev_priv(dev)->real_dev;
105 
106 	while (is_vlan_dev(ret))
107 		ret = vlan_dev_priv(ret)->real_dev;
108 
109 	return ret;
110 }
111 EXPORT_SYMBOL(vlan_dev_real_dev);
112 
113 u16 vlan_dev_vlan_id(const struct net_device *dev)
114 {
115 	return vlan_dev_priv(dev)->vlan_id;
116 }
117 EXPORT_SYMBOL(vlan_dev_vlan_id);
118 
119 __be16 vlan_dev_vlan_proto(const struct net_device *dev)
120 {
121 	return vlan_dev_priv(dev)->vlan_proto;
122 }
123 EXPORT_SYMBOL(vlan_dev_vlan_proto);
124 
125 /*
126  * vlan info and vid list
127  */
128 
129 static void vlan_group_free(struct vlan_group *grp)
130 {
131 	int i, j;
132 
133 	for (i = 0; i < VLAN_PROTO_NUM; i++)
134 		for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
135 			kfree(grp->vlan_devices_arrays[i][j]);
136 }
137 
138 static void vlan_info_free(struct vlan_info *vlan_info)
139 {
140 	vlan_group_free(&vlan_info->grp);
141 	kfree(vlan_info);
142 }
143 
144 static void vlan_info_rcu_free(struct rcu_head *rcu)
145 {
146 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
147 }
148 
149 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
150 {
151 	struct vlan_info *vlan_info;
152 
153 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
154 	if (!vlan_info)
155 		return NULL;
156 
157 	vlan_info->real_dev = dev;
158 	INIT_LIST_HEAD(&vlan_info->vid_list);
159 	return vlan_info;
160 }
161 
162 struct vlan_vid_info {
163 	struct list_head list;
164 	__be16 proto;
165 	u16 vid;
166 	int refcount;
167 };
168 
169 static bool vlan_hw_filter_capable(const struct net_device *dev, __be16 proto)
170 {
171 	if (proto == htons(ETH_P_8021Q) &&
172 	    dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
173 		return true;
174 	if (proto == htons(ETH_P_8021AD) &&
175 	    dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
176 		return true;
177 	return false;
178 }
179 
180 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
181 					       __be16 proto, u16 vid)
182 {
183 	struct vlan_vid_info *vid_info;
184 
185 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
186 		if (vid_info->proto == proto && vid_info->vid == vid)
187 			return vid_info;
188 	}
189 	return NULL;
190 }
191 
192 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
193 {
194 	struct vlan_vid_info *vid_info;
195 
196 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
197 	if (!vid_info)
198 		return NULL;
199 	vid_info->proto = proto;
200 	vid_info->vid = vid;
201 
202 	return vid_info;
203 }
204 
205 static int vlan_add_rx_filter_info(struct net_device *dev, __be16 proto, u16 vid)
206 {
207 	if (!vlan_hw_filter_capable(dev, proto))
208 		return 0;
209 
210 	if (netif_device_present(dev))
211 		return dev->netdev_ops->ndo_vlan_rx_add_vid(dev, proto, vid);
212 	else
213 		return -ENODEV;
214 }
215 
216 static int vlan_kill_rx_filter_info(struct net_device *dev, __be16 proto, u16 vid)
217 {
218 	if (!vlan_hw_filter_capable(dev, proto))
219 		return 0;
220 
221 	if (netif_device_present(dev))
222 		return dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
223 	else
224 		return -ENODEV;
225 }
226 
227 int vlan_for_each(struct net_device *dev,
228 		  int (*action)(struct net_device *dev, int vid, void *arg),
229 		  void *arg)
230 {
231 	struct vlan_vid_info *vid_info;
232 	struct vlan_info *vlan_info;
233 	struct net_device *vdev;
234 	int ret;
235 
236 	ASSERT_RTNL();
237 
238 	vlan_info = rtnl_dereference(dev->vlan_info);
239 	if (!vlan_info)
240 		return 0;
241 
242 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
243 		vdev = vlan_group_get_device(&vlan_info->grp, vid_info->proto,
244 					     vid_info->vid);
245 		ret = action(vdev, vid_info->vid, arg);
246 		if (ret)
247 			return ret;
248 	}
249 
250 	return 0;
251 }
252 EXPORT_SYMBOL(vlan_for_each);
253 
254 int vlan_filter_push_vids(struct vlan_info *vlan_info, __be16 proto)
255 {
256 	struct net_device *real_dev = vlan_info->real_dev;
257 	struct vlan_vid_info *vlan_vid_info;
258 	int err;
259 
260 	list_for_each_entry(vlan_vid_info, &vlan_info->vid_list, list) {
261 		if (vlan_vid_info->proto == proto) {
262 			err = vlan_add_rx_filter_info(real_dev, proto,
263 						      vlan_vid_info->vid);
264 			if (err)
265 				goto unwind;
266 		}
267 	}
268 
269 	return 0;
270 
271 unwind:
272 	list_for_each_entry_continue_reverse(vlan_vid_info,
273 					     &vlan_info->vid_list, list) {
274 		if (vlan_vid_info->proto == proto)
275 			vlan_kill_rx_filter_info(real_dev, proto,
276 						 vlan_vid_info->vid);
277 	}
278 
279 	return err;
280 }
281 EXPORT_SYMBOL(vlan_filter_push_vids);
282 
283 void vlan_filter_drop_vids(struct vlan_info *vlan_info, __be16 proto)
284 {
285 	struct vlan_vid_info *vlan_vid_info;
286 
287 	list_for_each_entry(vlan_vid_info, &vlan_info->vid_list, list)
288 		if (vlan_vid_info->proto == proto)
289 			vlan_kill_rx_filter_info(vlan_info->real_dev,
290 						 vlan_vid_info->proto,
291 						 vlan_vid_info->vid);
292 }
293 EXPORT_SYMBOL(vlan_filter_drop_vids);
294 
295 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
296 			  struct vlan_vid_info **pvid_info)
297 {
298 	struct net_device *dev = vlan_info->real_dev;
299 	struct vlan_vid_info *vid_info;
300 	int err;
301 
302 	vid_info = vlan_vid_info_alloc(proto, vid);
303 	if (!vid_info)
304 		return -ENOMEM;
305 
306 	err = vlan_add_rx_filter_info(dev, proto, vid);
307 	if (err) {
308 		kfree(vid_info);
309 		return err;
310 	}
311 
312 	list_add(&vid_info->list, &vlan_info->vid_list);
313 	vlan_info->nr_vids++;
314 	*pvid_info = vid_info;
315 	return 0;
316 }
317 
318 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
319 {
320 	struct vlan_info *vlan_info;
321 	struct vlan_vid_info *vid_info;
322 	bool vlan_info_created = false;
323 	int err;
324 
325 	ASSERT_RTNL();
326 
327 	vlan_info = rtnl_dereference(dev->vlan_info);
328 	if (!vlan_info) {
329 		vlan_info = vlan_info_alloc(dev);
330 		if (!vlan_info)
331 			return -ENOMEM;
332 		vlan_info_created = true;
333 	}
334 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
335 	if (!vid_info) {
336 		err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
337 		if (err)
338 			goto out_free_vlan_info;
339 	}
340 	vid_info->refcount++;
341 
342 	if (vlan_info_created)
343 		rcu_assign_pointer(dev->vlan_info, vlan_info);
344 
345 	return 0;
346 
347 out_free_vlan_info:
348 	if (vlan_info_created)
349 		kfree(vlan_info);
350 	return err;
351 }
352 EXPORT_SYMBOL(vlan_vid_add);
353 
354 static void __vlan_vid_del(struct vlan_info *vlan_info,
355 			   struct vlan_vid_info *vid_info)
356 {
357 	struct net_device *dev = vlan_info->real_dev;
358 	__be16 proto = vid_info->proto;
359 	u16 vid = vid_info->vid;
360 	int err;
361 
362 	err = vlan_kill_rx_filter_info(dev, proto, vid);
363 	if (err && dev->reg_state != NETREG_UNREGISTERING)
364 		netdev_warn(dev, "failed to kill vid %04x/%d\n", proto, vid);
365 
366 	list_del(&vid_info->list);
367 	kfree(vid_info);
368 	vlan_info->nr_vids--;
369 }
370 
371 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
372 {
373 	struct vlan_info *vlan_info;
374 	struct vlan_vid_info *vid_info;
375 
376 	ASSERT_RTNL();
377 
378 	vlan_info = rtnl_dereference(dev->vlan_info);
379 	if (!vlan_info)
380 		return;
381 
382 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
383 	if (!vid_info)
384 		return;
385 	vid_info->refcount--;
386 	if (vid_info->refcount == 0) {
387 		__vlan_vid_del(vlan_info, vid_info);
388 		if (vlan_info->nr_vids == 0) {
389 			RCU_INIT_POINTER(dev->vlan_info, NULL);
390 			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
391 		}
392 	}
393 }
394 EXPORT_SYMBOL(vlan_vid_del);
395 
396 int vlan_vids_add_by_dev(struct net_device *dev,
397 			 const struct net_device *by_dev)
398 {
399 	struct vlan_vid_info *vid_info;
400 	struct vlan_info *vlan_info;
401 	int err;
402 
403 	ASSERT_RTNL();
404 
405 	vlan_info = rtnl_dereference(by_dev->vlan_info);
406 	if (!vlan_info)
407 		return 0;
408 
409 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
410 		err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
411 		if (err)
412 			goto unwind;
413 	}
414 	return 0;
415 
416 unwind:
417 	list_for_each_entry_continue_reverse(vid_info,
418 					     &vlan_info->vid_list,
419 					     list) {
420 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
421 	}
422 
423 	return err;
424 }
425 EXPORT_SYMBOL(vlan_vids_add_by_dev);
426 
427 void vlan_vids_del_by_dev(struct net_device *dev,
428 			  const struct net_device *by_dev)
429 {
430 	struct vlan_vid_info *vid_info;
431 	struct vlan_info *vlan_info;
432 
433 	ASSERT_RTNL();
434 
435 	vlan_info = rtnl_dereference(by_dev->vlan_info);
436 	if (!vlan_info)
437 		return;
438 
439 	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
440 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
441 }
442 EXPORT_SYMBOL(vlan_vids_del_by_dev);
443 
444 bool vlan_uses_dev(const struct net_device *dev)
445 {
446 	struct vlan_info *vlan_info;
447 
448 	ASSERT_RTNL();
449 
450 	vlan_info = rtnl_dereference(dev->vlan_info);
451 	if (!vlan_info)
452 		return false;
453 	return vlan_info->grp.nr_vlan_devs ? true : false;
454 }
455 EXPORT_SYMBOL(vlan_uses_dev);
456 
457 static struct sk_buff *vlan_gro_receive(struct list_head *head,
458 					struct sk_buff *skb)
459 {
460 	const struct packet_offload *ptype;
461 	unsigned int hlen, off_vlan;
462 	struct sk_buff *pp = NULL;
463 	struct vlan_hdr *vhdr;
464 	struct sk_buff *p;
465 	__be16 type;
466 	int flush = 1;
467 
468 	off_vlan = skb_gro_offset(skb);
469 	hlen = off_vlan + sizeof(*vhdr);
470 	vhdr = skb_gro_header_fast(skb, off_vlan);
471 	if (skb_gro_header_hard(skb, hlen)) {
472 		vhdr = skb_gro_header_slow(skb, hlen, off_vlan);
473 		if (unlikely(!vhdr))
474 			goto out;
475 	}
476 
477 	type = vhdr->h_vlan_encapsulated_proto;
478 
479 	ptype = gro_find_receive_by_type(type);
480 	if (!ptype)
481 		goto out;
482 
483 	flush = 0;
484 
485 	list_for_each_entry(p, head, list) {
486 		struct vlan_hdr *vhdr2;
487 
488 		if (!NAPI_GRO_CB(p)->same_flow)
489 			continue;
490 
491 		vhdr2 = (struct vlan_hdr *)(p->data + off_vlan);
492 		if (compare_vlan_header(vhdr, vhdr2))
493 			NAPI_GRO_CB(p)->same_flow = 0;
494 	}
495 
496 	skb_gro_pull(skb, sizeof(*vhdr));
497 	skb_gro_postpull_rcsum(skb, vhdr, sizeof(*vhdr));
498 
499 	pp = indirect_call_gro_receive_inet(ptype->callbacks.gro_receive,
500 					    ipv6_gro_receive, inet_gro_receive,
501 					    head, skb);
502 
503 out:
504 	skb_gro_flush_final(skb, pp, flush);
505 
506 	return pp;
507 }
508 
509 static int vlan_gro_complete(struct sk_buff *skb, int nhoff)
510 {
511 	struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data + nhoff);
512 	__be16 type = vhdr->h_vlan_encapsulated_proto;
513 	struct packet_offload *ptype;
514 	int err = -ENOENT;
515 
516 	ptype = gro_find_complete_by_type(type);
517 	if (ptype)
518 		err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
519 					 ipv6_gro_complete, inet_gro_complete,
520 					 skb, nhoff + sizeof(*vhdr));
521 
522 	return err;
523 }
524 
525 static struct packet_offload vlan_packet_offloads[] __read_mostly = {
526 	{
527 		.type = cpu_to_be16(ETH_P_8021Q),
528 		.priority = 10,
529 		.callbacks = {
530 			.gro_receive = vlan_gro_receive,
531 			.gro_complete = vlan_gro_complete,
532 		},
533 	},
534 	{
535 		.type = cpu_to_be16(ETH_P_8021AD),
536 		.priority = 10,
537 		.callbacks = {
538 			.gro_receive = vlan_gro_receive,
539 			.gro_complete = vlan_gro_complete,
540 		},
541 	},
542 };
543 
544 static int __init vlan_offload_init(void)
545 {
546 	unsigned int i;
547 
548 	for (i = 0; i < ARRAY_SIZE(vlan_packet_offloads); i++)
549 		dev_add_offload(&vlan_packet_offloads[i]);
550 
551 	return 0;
552 }
553 
554 fs_initcall(vlan_offload_init);
555