xref: /openbmc/linux/net/8021q/vlan_core.c (revision b60a5b8d)
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 "vlan.h"
8 
9 bool vlan_do_receive(struct sk_buff **skbp)
10 {
11 	struct sk_buff *skb = *skbp;
12 	__be16 vlan_proto = skb->vlan_proto;
13 	u16 vlan_id = skb_vlan_tag_get_id(skb);
14 	struct net_device *vlan_dev;
15 	struct vlan_pcpu_stats *rx_stats;
16 
17 	vlan_dev = vlan_find_dev(skb->dev, vlan_proto, vlan_id);
18 	if (!vlan_dev)
19 		return false;
20 
21 	skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
22 	if (unlikely(!skb))
23 		return false;
24 
25 	if (unlikely(!(vlan_dev->flags & IFF_UP))) {
26 		kfree_skb(skb);
27 		*skbp = NULL;
28 		return false;
29 	}
30 
31 	skb->dev = vlan_dev;
32 	if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
33 		/* Our lower layer thinks this is not local, let's make sure.
34 		 * This allows the VLAN to have a different MAC than the
35 		 * underlying device, and still route correctly. */
36 		if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
37 			skb->pkt_type = PACKET_HOST;
38 	}
39 
40 	if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR) &&
41 	    !netif_is_macvlan_port(vlan_dev) &&
42 	    !netif_is_bridge_port(vlan_dev)) {
43 		unsigned int offset = skb->data - skb_mac_header(skb);
44 
45 		/*
46 		 * vlan_insert_tag expect skb->data pointing to mac header.
47 		 * So change skb->data before calling it and change back to
48 		 * original position later
49 		 */
50 		skb_push(skb, offset);
51 		skb = *skbp = vlan_insert_inner_tag(skb, skb->vlan_proto,
52 						    skb->vlan_tci, skb->mac_len);
53 		if (!skb)
54 			return false;
55 		skb_pull(skb, offset + VLAN_HLEN);
56 		skb_reset_mac_len(skb);
57 	}
58 
59 	skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
60 	__vlan_hwaccel_clear_tag(skb);
61 
62 	rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
63 
64 	u64_stats_update_begin(&rx_stats->syncp);
65 	rx_stats->rx_packets++;
66 	rx_stats->rx_bytes += skb->len;
67 	if (skb->pkt_type == PACKET_MULTICAST)
68 		rx_stats->rx_multicast++;
69 	u64_stats_update_end(&rx_stats->syncp);
70 
71 	return true;
72 }
73 
74 /* Must be invoked with rcu_read_lock. */
75 struct net_device *__vlan_find_dev_deep_rcu(struct net_device *dev,
76 					__be16 vlan_proto, u16 vlan_id)
77 {
78 	struct vlan_info *vlan_info = rcu_dereference(dev->vlan_info);
79 
80 	if (vlan_info) {
81 		return vlan_group_get_device(&vlan_info->grp,
82 					     vlan_proto, vlan_id);
83 	} else {
84 		/*
85 		 * Lower devices of master uppers (bonding, team) do not have
86 		 * grp assigned to themselves. Grp is assigned to upper device
87 		 * instead.
88 		 */
89 		struct net_device *upper_dev;
90 
91 		upper_dev = netdev_master_upper_dev_get_rcu(dev);
92 		if (upper_dev)
93 			return __vlan_find_dev_deep_rcu(upper_dev,
94 						    vlan_proto, vlan_id);
95 	}
96 
97 	return NULL;
98 }
99 EXPORT_SYMBOL(__vlan_find_dev_deep_rcu);
100 
101 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
102 {
103 	struct net_device *ret = vlan_dev_priv(dev)->real_dev;
104 
105 	while (is_vlan_dev(ret))
106 		ret = vlan_dev_priv(ret)->real_dev;
107 
108 	return ret;
109 }
110 EXPORT_SYMBOL(vlan_dev_real_dev);
111 
112 u16 vlan_dev_vlan_id(const struct net_device *dev)
113 {
114 	return vlan_dev_priv(dev)->vlan_id;
115 }
116 EXPORT_SYMBOL(vlan_dev_vlan_id);
117 
118 __be16 vlan_dev_vlan_proto(const struct net_device *dev)
119 {
120 	return vlan_dev_priv(dev)->vlan_proto;
121 }
122 EXPORT_SYMBOL(vlan_dev_vlan_proto);
123 
124 /*
125  * vlan info and vid list
126  */
127 
128 static void vlan_group_free(struct vlan_group *grp)
129 {
130 	int i, j;
131 
132 	for (i = 0; i < VLAN_PROTO_NUM; i++)
133 		for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
134 			kfree(grp->vlan_devices_arrays[i][j]);
135 }
136 
137 static void vlan_info_free(struct vlan_info *vlan_info)
138 {
139 	vlan_group_free(&vlan_info->grp);
140 	kfree(vlan_info);
141 }
142 
143 static void vlan_info_rcu_free(struct rcu_head *rcu)
144 {
145 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
146 }
147 
148 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
149 {
150 	struct vlan_info *vlan_info;
151 
152 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
153 	if (!vlan_info)
154 		return NULL;
155 
156 	vlan_info->real_dev = dev;
157 	INIT_LIST_HEAD(&vlan_info->vid_list);
158 	return vlan_info;
159 }
160 
161 struct vlan_vid_info {
162 	struct list_head list;
163 	__be16 proto;
164 	u16 vid;
165 	int refcount;
166 };
167 
168 static bool vlan_hw_filter_capable(const struct net_device *dev, __be16 proto)
169 {
170 	if (proto == htons(ETH_P_8021Q) &&
171 	    dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
172 		return true;
173 	if (proto == htons(ETH_P_8021AD) &&
174 	    dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
175 		return true;
176 	return false;
177 }
178 
179 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
180 					       __be16 proto, u16 vid)
181 {
182 	struct vlan_vid_info *vid_info;
183 
184 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
185 		if (vid_info->proto == proto && vid_info->vid == vid)
186 			return vid_info;
187 	}
188 	return NULL;
189 }
190 
191 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
192 {
193 	struct vlan_vid_info *vid_info;
194 
195 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
196 	if (!vid_info)
197 		return NULL;
198 	vid_info->proto = proto;
199 	vid_info->vid = vid;
200 
201 	return vid_info;
202 }
203 
204 static int vlan_add_rx_filter_info(struct net_device *dev, __be16 proto, u16 vid)
205 {
206 	if (!vlan_hw_filter_capable(dev, proto))
207 		return 0;
208 
209 	if (netif_device_present(dev))
210 		return dev->netdev_ops->ndo_vlan_rx_add_vid(dev, proto, vid);
211 	else
212 		return -ENODEV;
213 }
214 
215 static int vlan_kill_rx_filter_info(struct net_device *dev, __be16 proto, u16 vid)
216 {
217 	if (!vlan_hw_filter_capable(dev, proto))
218 		return 0;
219 
220 	if (netif_device_present(dev))
221 		return dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
222 	else
223 		return -ENODEV;
224 }
225 
226 int vlan_for_each(struct net_device *dev,
227 		  int (*action)(struct net_device *dev, int vid, void *arg),
228 		  void *arg)
229 {
230 	struct vlan_vid_info *vid_info;
231 	struct vlan_info *vlan_info;
232 	struct net_device *vdev;
233 	int ret;
234 
235 	ASSERT_RTNL();
236 
237 	vlan_info = rtnl_dereference(dev->vlan_info);
238 	if (!vlan_info)
239 		return 0;
240 
241 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
242 		vdev = vlan_group_get_device(&vlan_info->grp, vid_info->proto,
243 					     vid_info->vid);
244 		ret = action(vdev, vid_info->vid, arg);
245 		if (ret)
246 			return ret;
247 	}
248 
249 	return 0;
250 }
251 EXPORT_SYMBOL(vlan_for_each);
252 
253 int vlan_filter_push_vids(struct vlan_info *vlan_info, __be16 proto)
254 {
255 	struct net_device *real_dev = vlan_info->real_dev;
256 	struct vlan_vid_info *vlan_vid_info;
257 	int err;
258 
259 	list_for_each_entry(vlan_vid_info, &vlan_info->vid_list, list) {
260 		if (vlan_vid_info->proto == proto) {
261 			err = vlan_add_rx_filter_info(real_dev, proto,
262 						      vlan_vid_info->vid);
263 			if (err)
264 				goto unwind;
265 		}
266 	}
267 
268 	return 0;
269 
270 unwind:
271 	list_for_each_entry_continue_reverse(vlan_vid_info,
272 					     &vlan_info->vid_list, list) {
273 		if (vlan_vid_info->proto == proto)
274 			vlan_kill_rx_filter_info(real_dev, proto,
275 						 vlan_vid_info->vid);
276 	}
277 
278 	return err;
279 }
280 EXPORT_SYMBOL(vlan_filter_push_vids);
281 
282 void vlan_filter_drop_vids(struct vlan_info *vlan_info, __be16 proto)
283 {
284 	struct vlan_vid_info *vlan_vid_info;
285 
286 	list_for_each_entry(vlan_vid_info, &vlan_info->vid_list, list)
287 		if (vlan_vid_info->proto == proto)
288 			vlan_kill_rx_filter_info(vlan_info->real_dev,
289 						 vlan_vid_info->proto,
290 						 vlan_vid_info->vid);
291 }
292 EXPORT_SYMBOL(vlan_filter_drop_vids);
293 
294 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
295 			  struct vlan_vid_info **pvid_info)
296 {
297 	struct net_device *dev = vlan_info->real_dev;
298 	struct vlan_vid_info *vid_info;
299 	int err;
300 
301 	vid_info = vlan_vid_info_alloc(proto, vid);
302 	if (!vid_info)
303 		return -ENOMEM;
304 
305 	err = vlan_add_rx_filter_info(dev, proto, vid);
306 	if (err) {
307 		kfree(vid_info);
308 		return err;
309 	}
310 
311 	list_add(&vid_info->list, &vlan_info->vid_list);
312 	vlan_info->nr_vids++;
313 	*pvid_info = vid_info;
314 	return 0;
315 }
316 
317 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
318 {
319 	struct vlan_info *vlan_info;
320 	struct vlan_vid_info *vid_info;
321 	bool vlan_info_created = false;
322 	int err;
323 
324 	ASSERT_RTNL();
325 
326 	vlan_info = rtnl_dereference(dev->vlan_info);
327 	if (!vlan_info) {
328 		vlan_info = vlan_info_alloc(dev);
329 		if (!vlan_info)
330 			return -ENOMEM;
331 		vlan_info_created = true;
332 	}
333 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
334 	if (!vid_info) {
335 		err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
336 		if (err)
337 			goto out_free_vlan_info;
338 	}
339 	vid_info->refcount++;
340 
341 	if (vlan_info_created)
342 		rcu_assign_pointer(dev->vlan_info, vlan_info);
343 
344 	return 0;
345 
346 out_free_vlan_info:
347 	if (vlan_info_created)
348 		kfree(vlan_info);
349 	return err;
350 }
351 EXPORT_SYMBOL(vlan_vid_add);
352 
353 static void __vlan_vid_del(struct vlan_info *vlan_info,
354 			   struct vlan_vid_info *vid_info)
355 {
356 	struct net_device *dev = vlan_info->real_dev;
357 	__be16 proto = vid_info->proto;
358 	u16 vid = vid_info->vid;
359 	int err;
360 
361 	err = vlan_kill_rx_filter_info(dev, proto, vid);
362 	if (err)
363 		pr_warn("failed to kill vid %04x/%d for device %s\n",
364 			proto, vid, dev->name);
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 	rcu_read_lock();
480 	ptype = gro_find_receive_by_type(type);
481 	if (!ptype)
482 		goto out_unlock;
483 
484 	flush = 0;
485 
486 	list_for_each_entry(p, head, list) {
487 		struct vlan_hdr *vhdr2;
488 
489 		if (!NAPI_GRO_CB(p)->same_flow)
490 			continue;
491 
492 		vhdr2 = (struct vlan_hdr *)(p->data + off_vlan);
493 		if (compare_vlan_header(vhdr, vhdr2))
494 			NAPI_GRO_CB(p)->same_flow = 0;
495 	}
496 
497 	skb_gro_pull(skb, sizeof(*vhdr));
498 	skb_gro_postpull_rcsum(skb, vhdr, sizeof(*vhdr));
499 	pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
500 
501 out_unlock:
502 	rcu_read_unlock();
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 	rcu_read_lock();
517 	ptype = gro_find_complete_by_type(type);
518 	if (ptype)
519 		err = ptype->callbacks.gro_complete(skb, nhoff + sizeof(*vhdr));
520 
521 	rcu_read_unlock();
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