xref: /linux/net/8021q/vlan_core.c (revision 9cfc5c90ad38c8fc11bfd39de42a107da00871ba)
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 = skb_vlan_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 /*
116  * vlan info and vid list
117  */
118 
119 static void vlan_group_free(struct vlan_group *grp)
120 {
121 	int i, j;
122 
123 	for (i = 0; i < VLAN_PROTO_NUM; i++)
124 		for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
125 			kfree(grp->vlan_devices_arrays[i][j]);
126 }
127 
128 static void vlan_info_free(struct vlan_info *vlan_info)
129 {
130 	vlan_group_free(&vlan_info->grp);
131 	kfree(vlan_info);
132 }
133 
134 static void vlan_info_rcu_free(struct rcu_head *rcu)
135 {
136 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
137 }
138 
139 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
140 {
141 	struct vlan_info *vlan_info;
142 
143 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
144 	if (!vlan_info)
145 		return NULL;
146 
147 	vlan_info->real_dev = dev;
148 	INIT_LIST_HEAD(&vlan_info->vid_list);
149 	return vlan_info;
150 }
151 
152 struct vlan_vid_info {
153 	struct list_head list;
154 	__be16 proto;
155 	u16 vid;
156 	int refcount;
157 };
158 
159 static bool vlan_hw_filter_capable(const struct net_device *dev,
160 				     const struct vlan_vid_info *vid_info)
161 {
162 	if (vid_info->proto == htons(ETH_P_8021Q) &&
163 	    dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
164 		return true;
165 	if (vid_info->proto == htons(ETH_P_8021AD) &&
166 	    dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
167 		return true;
168 	return false;
169 }
170 
171 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
172 					       __be16 proto, u16 vid)
173 {
174 	struct vlan_vid_info *vid_info;
175 
176 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
177 		if (vid_info->proto == proto && vid_info->vid == vid)
178 			return vid_info;
179 	}
180 	return NULL;
181 }
182 
183 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
184 {
185 	struct vlan_vid_info *vid_info;
186 
187 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
188 	if (!vid_info)
189 		return NULL;
190 	vid_info->proto = proto;
191 	vid_info->vid = vid;
192 
193 	return vid_info;
194 }
195 
196 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
197 			  struct vlan_vid_info **pvid_info)
198 {
199 	struct net_device *dev = vlan_info->real_dev;
200 	const struct net_device_ops *ops = dev->netdev_ops;
201 	struct vlan_vid_info *vid_info;
202 	int err;
203 
204 	vid_info = vlan_vid_info_alloc(proto, vid);
205 	if (!vid_info)
206 		return -ENOMEM;
207 
208 	if (vlan_hw_filter_capable(dev, vid_info)) {
209 		if (netif_device_present(dev))
210 			err = ops->ndo_vlan_rx_add_vid(dev, proto, vid);
211 		else
212 			err = -ENODEV;
213 		if (err) {
214 			kfree(vid_info);
215 			return err;
216 		}
217 	}
218 	list_add(&vid_info->list, &vlan_info->vid_list);
219 	vlan_info->nr_vids++;
220 	*pvid_info = vid_info;
221 	return 0;
222 }
223 
224 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
225 {
226 	struct vlan_info *vlan_info;
227 	struct vlan_vid_info *vid_info;
228 	bool vlan_info_created = false;
229 	int err;
230 
231 	ASSERT_RTNL();
232 
233 	vlan_info = rtnl_dereference(dev->vlan_info);
234 	if (!vlan_info) {
235 		vlan_info = vlan_info_alloc(dev);
236 		if (!vlan_info)
237 			return -ENOMEM;
238 		vlan_info_created = true;
239 	}
240 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
241 	if (!vid_info) {
242 		err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
243 		if (err)
244 			goto out_free_vlan_info;
245 	}
246 	vid_info->refcount++;
247 
248 	if (vlan_info_created)
249 		rcu_assign_pointer(dev->vlan_info, vlan_info);
250 
251 	return 0;
252 
253 out_free_vlan_info:
254 	if (vlan_info_created)
255 		kfree(vlan_info);
256 	return err;
257 }
258 EXPORT_SYMBOL(vlan_vid_add);
259 
260 static void __vlan_vid_del(struct vlan_info *vlan_info,
261 			   struct vlan_vid_info *vid_info)
262 {
263 	struct net_device *dev = vlan_info->real_dev;
264 	const struct net_device_ops *ops = dev->netdev_ops;
265 	__be16 proto = vid_info->proto;
266 	u16 vid = vid_info->vid;
267 	int err;
268 
269 	if (vlan_hw_filter_capable(dev, vid_info)) {
270 		if (netif_device_present(dev))
271 			err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
272 		else
273 			err = -ENODEV;
274 		if (err) {
275 			pr_warn("failed to kill vid %04x/%d for device %s\n",
276 				proto, vid, dev->name);
277 		}
278 	}
279 	list_del(&vid_info->list);
280 	kfree(vid_info);
281 	vlan_info->nr_vids--;
282 }
283 
284 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
285 {
286 	struct vlan_info *vlan_info;
287 	struct vlan_vid_info *vid_info;
288 
289 	ASSERT_RTNL();
290 
291 	vlan_info = rtnl_dereference(dev->vlan_info);
292 	if (!vlan_info)
293 		return;
294 
295 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
296 	if (!vid_info)
297 		return;
298 	vid_info->refcount--;
299 	if (vid_info->refcount == 0) {
300 		__vlan_vid_del(vlan_info, vid_info);
301 		if (vlan_info->nr_vids == 0) {
302 			RCU_INIT_POINTER(dev->vlan_info, NULL);
303 			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
304 		}
305 	}
306 }
307 EXPORT_SYMBOL(vlan_vid_del);
308 
309 int vlan_vids_add_by_dev(struct net_device *dev,
310 			 const struct net_device *by_dev)
311 {
312 	struct vlan_vid_info *vid_info;
313 	struct vlan_info *vlan_info;
314 	int err;
315 
316 	ASSERT_RTNL();
317 
318 	vlan_info = rtnl_dereference(by_dev->vlan_info);
319 	if (!vlan_info)
320 		return 0;
321 
322 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
323 		err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
324 		if (err)
325 			goto unwind;
326 	}
327 	return 0;
328 
329 unwind:
330 	list_for_each_entry_continue_reverse(vid_info,
331 					     &vlan_info->vid_list,
332 					     list) {
333 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
334 	}
335 
336 	return err;
337 }
338 EXPORT_SYMBOL(vlan_vids_add_by_dev);
339 
340 void vlan_vids_del_by_dev(struct net_device *dev,
341 			  const struct net_device *by_dev)
342 {
343 	struct vlan_vid_info *vid_info;
344 	struct vlan_info *vlan_info;
345 
346 	ASSERT_RTNL();
347 
348 	vlan_info = rtnl_dereference(by_dev->vlan_info);
349 	if (!vlan_info)
350 		return;
351 
352 	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
353 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
354 }
355 EXPORT_SYMBOL(vlan_vids_del_by_dev);
356 
357 bool vlan_uses_dev(const struct net_device *dev)
358 {
359 	struct vlan_info *vlan_info;
360 
361 	ASSERT_RTNL();
362 
363 	vlan_info = rtnl_dereference(dev->vlan_info);
364 	if (!vlan_info)
365 		return false;
366 	return vlan_info->grp.nr_vlan_devs ? true : false;
367 }
368 EXPORT_SYMBOL(vlan_uses_dev);
369