xref: /openbmc/linux/net/8021q/vlan_core.c (revision db181ce0)
1 #include <linux/skbuff.h>
2 #include <linux/netdevice.h>
3 #include <linux/if_vlan.h>
4 #include <linux/netpoll.h>
5 #include <linux/export.h>
6 #include "vlan.h"
7 
8 bool vlan_do_receive(struct sk_buff **skbp)
9 {
10 	struct sk_buff *skb = *skbp;
11 	__be16 vlan_proto = skb->vlan_proto;
12 	u16 vlan_id = vlan_tx_tag_get_id(skb);
13 	struct net_device *vlan_dev;
14 	struct vlan_pcpu_stats *rx_stats;
15 
16 	vlan_dev = vlan_find_dev(skb->dev, vlan_proto, vlan_id);
17 	if (!vlan_dev)
18 		return false;
19 
20 	skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
21 	if (unlikely(!skb))
22 		return false;
23 
24 	skb->dev = vlan_dev;
25 	if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
26 		/* Our lower layer thinks this is not local, let's make sure.
27 		 * This allows the VLAN to have a different MAC than the
28 		 * underlying device, and still route correctly. */
29 		if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
30 			skb->pkt_type = PACKET_HOST;
31 	}
32 
33 	if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
34 		unsigned int offset = skb->data - skb_mac_header(skb);
35 
36 		/*
37 		 * vlan_insert_tag expect skb->data pointing to mac header.
38 		 * So change skb->data before calling it and change back to
39 		 * original position later
40 		 */
41 		skb_push(skb, offset);
42 		skb = *skbp = vlan_insert_tag(skb, skb->vlan_proto,
43 					      skb->vlan_tci);
44 		if (!skb)
45 			return false;
46 		skb_pull(skb, offset + VLAN_HLEN);
47 		skb_reset_mac_len(skb);
48 	}
49 
50 	skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
51 	skb->vlan_tci = 0;
52 
53 	rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
54 
55 	u64_stats_update_begin(&rx_stats->syncp);
56 	rx_stats->rx_packets++;
57 	rx_stats->rx_bytes += skb->len;
58 	if (skb->pkt_type == PACKET_MULTICAST)
59 		rx_stats->rx_multicast++;
60 	u64_stats_update_end(&rx_stats->syncp);
61 
62 	return true;
63 }
64 
65 /* Must be invoked with rcu_read_lock. */
66 struct net_device *__vlan_find_dev_deep_rcu(struct net_device *dev,
67 					__be16 vlan_proto, u16 vlan_id)
68 {
69 	struct vlan_info *vlan_info = rcu_dereference(dev->vlan_info);
70 
71 	if (vlan_info) {
72 		return vlan_group_get_device(&vlan_info->grp,
73 					     vlan_proto, vlan_id);
74 	} else {
75 		/*
76 		 * Lower devices of master uppers (bonding, team) do not have
77 		 * grp assigned to themselves. Grp is assigned to upper device
78 		 * instead.
79 		 */
80 		struct net_device *upper_dev;
81 
82 		upper_dev = netdev_master_upper_dev_get_rcu(dev);
83 		if (upper_dev)
84 			return __vlan_find_dev_deep_rcu(upper_dev,
85 						    vlan_proto, vlan_id);
86 	}
87 
88 	return NULL;
89 }
90 EXPORT_SYMBOL(__vlan_find_dev_deep_rcu);
91 
92 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
93 {
94 	struct net_device *ret = vlan_dev_priv(dev)->real_dev;
95 
96 	while (is_vlan_dev(ret))
97 		ret = vlan_dev_priv(ret)->real_dev;
98 
99 	return ret;
100 }
101 EXPORT_SYMBOL(vlan_dev_real_dev);
102 
103 u16 vlan_dev_vlan_id(const struct net_device *dev)
104 {
105 	return vlan_dev_priv(dev)->vlan_id;
106 }
107 EXPORT_SYMBOL(vlan_dev_vlan_id);
108 
109 __be16 vlan_dev_vlan_proto(const struct net_device *dev)
110 {
111 	return vlan_dev_priv(dev)->vlan_proto;
112 }
113 EXPORT_SYMBOL(vlan_dev_vlan_proto);
114 
115 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
116 {
117 	if (skb_cow(skb, skb_headroom(skb)) < 0) {
118 		kfree_skb(skb);
119 		return NULL;
120 	}
121 
122 	memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
123 	skb->mac_header += VLAN_HLEN;
124 	return skb;
125 }
126 
127 struct sk_buff *vlan_untag(struct sk_buff *skb)
128 {
129 	struct vlan_hdr *vhdr;
130 	u16 vlan_tci;
131 
132 	if (unlikely(vlan_tx_tag_present(skb))) {
133 		/* vlan_tci is already set-up so leave this for another time */
134 		return skb;
135 	}
136 
137 	skb = skb_share_check(skb, GFP_ATOMIC);
138 	if (unlikely(!skb))
139 		goto err_free;
140 
141 	if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
142 		goto err_free;
143 
144 	vhdr = (struct vlan_hdr *) skb->data;
145 	vlan_tci = ntohs(vhdr->h_vlan_TCI);
146 	__vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
147 
148 	skb_pull_rcsum(skb, VLAN_HLEN);
149 	vlan_set_encap_proto(skb, vhdr);
150 
151 	skb = vlan_reorder_header(skb);
152 	if (unlikely(!skb))
153 		goto err_free;
154 
155 	skb_reset_network_header(skb);
156 	skb_reset_transport_header(skb);
157 	skb_reset_mac_len(skb);
158 
159 	return skb;
160 
161 err_free:
162 	kfree_skb(skb);
163 	return NULL;
164 }
165 EXPORT_SYMBOL(vlan_untag);
166 
167 
168 /*
169  * vlan info and vid list
170  */
171 
172 static void vlan_group_free(struct vlan_group *grp)
173 {
174 	int i, j;
175 
176 	for (i = 0; i < VLAN_PROTO_NUM; i++)
177 		for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
178 			kfree(grp->vlan_devices_arrays[i][j]);
179 }
180 
181 static void vlan_info_free(struct vlan_info *vlan_info)
182 {
183 	vlan_group_free(&vlan_info->grp);
184 	kfree(vlan_info);
185 }
186 
187 static void vlan_info_rcu_free(struct rcu_head *rcu)
188 {
189 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
190 }
191 
192 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
193 {
194 	struct vlan_info *vlan_info;
195 
196 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
197 	if (!vlan_info)
198 		return NULL;
199 
200 	vlan_info->real_dev = dev;
201 	INIT_LIST_HEAD(&vlan_info->vid_list);
202 	return vlan_info;
203 }
204 
205 struct vlan_vid_info {
206 	struct list_head list;
207 	__be16 proto;
208 	u16 vid;
209 	int refcount;
210 };
211 
212 static bool vlan_hw_filter_capable(const struct net_device *dev,
213 				     const struct vlan_vid_info *vid_info)
214 {
215 	if (vid_info->proto == htons(ETH_P_8021Q) &&
216 	    dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
217 		return true;
218 	if (vid_info->proto == htons(ETH_P_8021AD) &&
219 	    dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
220 		return true;
221 	return false;
222 }
223 
224 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
225 					       __be16 proto, u16 vid)
226 {
227 	struct vlan_vid_info *vid_info;
228 
229 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
230 		if (vid_info->proto == proto && vid_info->vid == vid)
231 			return vid_info;
232 	}
233 	return NULL;
234 }
235 
236 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
237 {
238 	struct vlan_vid_info *vid_info;
239 
240 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
241 	if (!vid_info)
242 		return NULL;
243 	vid_info->proto = proto;
244 	vid_info->vid = vid;
245 
246 	return vid_info;
247 }
248 
249 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
250 			  struct vlan_vid_info **pvid_info)
251 {
252 	struct net_device *dev = vlan_info->real_dev;
253 	const struct net_device_ops *ops = dev->netdev_ops;
254 	struct vlan_vid_info *vid_info;
255 	int err;
256 
257 	vid_info = vlan_vid_info_alloc(proto, vid);
258 	if (!vid_info)
259 		return -ENOMEM;
260 
261 	if (vlan_hw_filter_capable(dev, vid_info)) {
262 		err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
263 		if (err) {
264 			kfree(vid_info);
265 			return err;
266 		}
267 	}
268 	list_add(&vid_info->list, &vlan_info->vid_list);
269 	vlan_info->nr_vids++;
270 	*pvid_info = vid_info;
271 	return 0;
272 }
273 
274 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
275 {
276 	struct vlan_info *vlan_info;
277 	struct vlan_vid_info *vid_info;
278 	bool vlan_info_created = false;
279 	int err;
280 
281 	ASSERT_RTNL();
282 
283 	vlan_info = rtnl_dereference(dev->vlan_info);
284 	if (!vlan_info) {
285 		vlan_info = vlan_info_alloc(dev);
286 		if (!vlan_info)
287 			return -ENOMEM;
288 		vlan_info_created = true;
289 	}
290 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
291 	if (!vid_info) {
292 		err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
293 		if (err)
294 			goto out_free_vlan_info;
295 	}
296 	vid_info->refcount++;
297 
298 	if (vlan_info_created)
299 		rcu_assign_pointer(dev->vlan_info, vlan_info);
300 
301 	return 0;
302 
303 out_free_vlan_info:
304 	if (vlan_info_created)
305 		kfree(vlan_info);
306 	return err;
307 }
308 EXPORT_SYMBOL(vlan_vid_add);
309 
310 static void __vlan_vid_del(struct vlan_info *vlan_info,
311 			   struct vlan_vid_info *vid_info)
312 {
313 	struct net_device *dev = vlan_info->real_dev;
314 	const struct net_device_ops *ops = dev->netdev_ops;
315 	__be16 proto = vid_info->proto;
316 	u16 vid = vid_info->vid;
317 	int err;
318 
319 	if (vlan_hw_filter_capable(dev, vid_info)) {
320 		err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
321 		if (err) {
322 			pr_warn("failed to kill vid %04x/%d for device %s\n",
323 				proto, vid, dev->name);
324 		}
325 	}
326 	list_del(&vid_info->list);
327 	kfree(vid_info);
328 	vlan_info->nr_vids--;
329 }
330 
331 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
332 {
333 	struct vlan_info *vlan_info;
334 	struct vlan_vid_info *vid_info;
335 
336 	ASSERT_RTNL();
337 
338 	vlan_info = rtnl_dereference(dev->vlan_info);
339 	if (!vlan_info)
340 		return;
341 
342 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
343 	if (!vid_info)
344 		return;
345 	vid_info->refcount--;
346 	if (vid_info->refcount == 0) {
347 		__vlan_vid_del(vlan_info, vid_info);
348 		if (vlan_info->nr_vids == 0) {
349 			RCU_INIT_POINTER(dev->vlan_info, NULL);
350 			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
351 		}
352 	}
353 }
354 EXPORT_SYMBOL(vlan_vid_del);
355 
356 int vlan_vids_add_by_dev(struct net_device *dev,
357 			 const struct net_device *by_dev)
358 {
359 	struct vlan_vid_info *vid_info;
360 	struct vlan_info *vlan_info;
361 	int err;
362 
363 	ASSERT_RTNL();
364 
365 	vlan_info = rtnl_dereference(by_dev->vlan_info);
366 	if (!vlan_info)
367 		return 0;
368 
369 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
370 		err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
371 		if (err)
372 			goto unwind;
373 	}
374 	return 0;
375 
376 unwind:
377 	list_for_each_entry_continue_reverse(vid_info,
378 					     &vlan_info->vid_list,
379 					     list) {
380 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
381 	}
382 
383 	return err;
384 }
385 EXPORT_SYMBOL(vlan_vids_add_by_dev);
386 
387 void vlan_vids_del_by_dev(struct net_device *dev,
388 			  const struct net_device *by_dev)
389 {
390 	struct vlan_vid_info *vid_info;
391 	struct vlan_info *vlan_info;
392 
393 	ASSERT_RTNL();
394 
395 	vlan_info = rtnl_dereference(by_dev->vlan_info);
396 	if (!vlan_info)
397 		return;
398 
399 	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
400 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
401 }
402 EXPORT_SYMBOL(vlan_vids_del_by_dev);
403 
404 bool vlan_uses_dev(const struct net_device *dev)
405 {
406 	struct vlan_info *vlan_info;
407 
408 	ASSERT_RTNL();
409 
410 	vlan_info = rtnl_dereference(dev->vlan_info);
411 	if (!vlan_info)
412 		return false;
413 	return vlan_info->grp.nr_vlan_devs ? true : false;
414 }
415 EXPORT_SYMBOL(vlan_uses_dev);
416