xref: /linux/net/8021q/vlan_core.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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, bool last_handler)
9 {
10 	struct sk_buff *skb = *skbp;
11 	u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK;
12 	struct net_device *vlan_dev;
13 	struct vlan_pcpu_stats *rx_stats;
14 
15 	vlan_dev = vlan_find_dev(skb->dev, vlan_id);
16 	if (!vlan_dev) {
17 		/* Only the last call to vlan_do_receive() should change
18 		 * pkt_type to PACKET_OTHERHOST
19 		 */
20 		if (vlan_id && last_handler)
21 			skb->pkt_type = PACKET_OTHERHOST;
22 		return false;
23 	}
24 
25 	skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
26 	if (unlikely(!skb))
27 		return false;
28 
29 	skb->dev = vlan_dev;
30 	if (skb->pkt_type == PACKET_OTHERHOST) {
31 		/* Our lower layer thinks this is not local, let's make sure.
32 		 * This allows the VLAN to have a different MAC than the
33 		 * underlying device, and still route correctly. */
34 		if (ether_addr_equal(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
35 			skb->pkt_type = PACKET_HOST;
36 	}
37 
38 	if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
39 		unsigned int offset = skb->data - skb_mac_header(skb);
40 
41 		/*
42 		 * vlan_insert_tag expect skb->data pointing to mac header.
43 		 * So change skb->data before calling it and change back to
44 		 * original position later
45 		 */
46 		skb_push(skb, offset);
47 		skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci);
48 		if (!skb)
49 			return false;
50 		skb_pull(skb, offset + VLAN_HLEN);
51 		skb_reset_mac_len(skb);
52 	}
53 
54 	skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
55 	skb->vlan_tci = 0;
56 
57 	rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
58 
59 	u64_stats_update_begin(&rx_stats->syncp);
60 	rx_stats->rx_packets++;
61 	rx_stats->rx_bytes += skb->len;
62 	if (skb->pkt_type == PACKET_MULTICAST)
63 		rx_stats->rx_multicast++;
64 	u64_stats_update_end(&rx_stats->syncp);
65 
66 	return true;
67 }
68 
69 /* Must be invoked with rcu_read_lock or with RTNL. */
70 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
71 					u16 vlan_id)
72 {
73 	struct vlan_info *vlan_info = rcu_dereference_rtnl(real_dev->vlan_info);
74 
75 	if (vlan_info) {
76 		return vlan_group_get_device(&vlan_info->grp, vlan_id);
77 	} else {
78 		/*
79 		 * Bonding slaves do not have grp assigned to themselves.
80 		 * Grp is assigned to bonding master instead.
81 		 */
82 		if (netif_is_bond_slave(real_dev))
83 			return __vlan_find_dev_deep(real_dev->master, vlan_id);
84 	}
85 
86 	return NULL;
87 }
88 EXPORT_SYMBOL(__vlan_find_dev_deep);
89 
90 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
91 {
92 	return vlan_dev_priv(dev)->real_dev;
93 }
94 EXPORT_SYMBOL(vlan_dev_real_dev);
95 
96 u16 vlan_dev_vlan_id(const struct net_device *dev)
97 {
98 	return vlan_dev_priv(dev)->vlan_id;
99 }
100 EXPORT_SYMBOL(vlan_dev_vlan_id);
101 
102 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
103 {
104 	if (skb_cow(skb, skb_headroom(skb)) < 0)
105 		return NULL;
106 	memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
107 	skb->mac_header += VLAN_HLEN;
108 	skb_reset_mac_len(skb);
109 	return skb;
110 }
111 
112 struct sk_buff *vlan_untag(struct sk_buff *skb)
113 {
114 	struct vlan_hdr *vhdr;
115 	u16 vlan_tci;
116 
117 	if (unlikely(vlan_tx_tag_present(skb))) {
118 		/* vlan_tci is already set-up so leave this for another time */
119 		return skb;
120 	}
121 
122 	skb = skb_share_check(skb, GFP_ATOMIC);
123 	if (unlikely(!skb))
124 		goto err_free;
125 
126 	if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
127 		goto err_free;
128 
129 	vhdr = (struct vlan_hdr *) skb->data;
130 	vlan_tci = ntohs(vhdr->h_vlan_TCI);
131 	__vlan_hwaccel_put_tag(skb, vlan_tci);
132 
133 	skb_pull_rcsum(skb, VLAN_HLEN);
134 	vlan_set_encap_proto(skb, vhdr);
135 
136 	skb = vlan_reorder_header(skb);
137 	if (unlikely(!skb))
138 		goto err_free;
139 
140 	skb_reset_network_header(skb);
141 	skb_reset_transport_header(skb);
142 	return skb;
143 
144 err_free:
145 	kfree_skb(skb);
146 	return NULL;
147 }
148 
149 
150 /*
151  * vlan info and vid list
152  */
153 
154 static void vlan_group_free(struct vlan_group *grp)
155 {
156 	int i;
157 
158 	for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
159 		kfree(grp->vlan_devices_arrays[i]);
160 }
161 
162 static void vlan_info_free(struct vlan_info *vlan_info)
163 {
164 	vlan_group_free(&vlan_info->grp);
165 	kfree(vlan_info);
166 }
167 
168 static void vlan_info_rcu_free(struct rcu_head *rcu)
169 {
170 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
171 }
172 
173 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
174 {
175 	struct vlan_info *vlan_info;
176 
177 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
178 	if (!vlan_info)
179 		return NULL;
180 
181 	vlan_info->real_dev = dev;
182 	INIT_LIST_HEAD(&vlan_info->vid_list);
183 	return vlan_info;
184 }
185 
186 struct vlan_vid_info {
187 	struct list_head list;
188 	unsigned short vid;
189 	int refcount;
190 };
191 
192 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
193 					       unsigned short vid)
194 {
195 	struct vlan_vid_info *vid_info;
196 
197 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
198 		if (vid_info->vid == vid)
199 			return vid_info;
200 	}
201 	return NULL;
202 }
203 
204 static struct vlan_vid_info *vlan_vid_info_alloc(unsigned short vid)
205 {
206 	struct vlan_vid_info *vid_info;
207 
208 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
209 	if (!vid_info)
210 		return NULL;
211 	vid_info->vid = vid;
212 
213 	return vid_info;
214 }
215 
216 static int __vlan_vid_add(struct vlan_info *vlan_info, unsigned short vid,
217 			  struct vlan_vid_info **pvid_info)
218 {
219 	struct net_device *dev = vlan_info->real_dev;
220 	const struct net_device_ops *ops = dev->netdev_ops;
221 	struct vlan_vid_info *vid_info;
222 	int err;
223 
224 	vid_info = vlan_vid_info_alloc(vid);
225 	if (!vid_info)
226 		return -ENOMEM;
227 
228 	if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
229 	    ops->ndo_vlan_rx_add_vid) {
230 		err =  ops->ndo_vlan_rx_add_vid(dev, vid);
231 		if (err) {
232 			kfree(vid_info);
233 			return err;
234 		}
235 	}
236 	list_add(&vid_info->list, &vlan_info->vid_list);
237 	vlan_info->nr_vids++;
238 	*pvid_info = vid_info;
239 	return 0;
240 }
241 
242 int vlan_vid_add(struct net_device *dev, unsigned short vid)
243 {
244 	struct vlan_info *vlan_info;
245 	struct vlan_vid_info *vid_info;
246 	bool vlan_info_created = false;
247 	int err;
248 
249 	ASSERT_RTNL();
250 
251 	vlan_info = rtnl_dereference(dev->vlan_info);
252 	if (!vlan_info) {
253 		vlan_info = vlan_info_alloc(dev);
254 		if (!vlan_info)
255 			return -ENOMEM;
256 		vlan_info_created = true;
257 	}
258 	vid_info = vlan_vid_info_get(vlan_info, vid);
259 	if (!vid_info) {
260 		err = __vlan_vid_add(vlan_info, vid, &vid_info);
261 		if (err)
262 			goto out_free_vlan_info;
263 	}
264 	vid_info->refcount++;
265 
266 	if (vlan_info_created)
267 		rcu_assign_pointer(dev->vlan_info, vlan_info);
268 
269 	return 0;
270 
271 out_free_vlan_info:
272 	if (vlan_info_created)
273 		kfree(vlan_info);
274 	return err;
275 }
276 EXPORT_SYMBOL(vlan_vid_add);
277 
278 static void __vlan_vid_del(struct vlan_info *vlan_info,
279 			   struct vlan_vid_info *vid_info)
280 {
281 	struct net_device *dev = vlan_info->real_dev;
282 	const struct net_device_ops *ops = dev->netdev_ops;
283 	unsigned short vid = vid_info->vid;
284 	int err;
285 
286 	if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
287 	     ops->ndo_vlan_rx_kill_vid) {
288 		err = ops->ndo_vlan_rx_kill_vid(dev, vid);
289 		if (err) {
290 			pr_warn("failed to kill vid %d for device %s\n",
291 				vid, dev->name);
292 		}
293 	}
294 	list_del(&vid_info->list);
295 	kfree(vid_info);
296 	vlan_info->nr_vids--;
297 }
298 
299 void vlan_vid_del(struct net_device *dev, unsigned short vid)
300 {
301 	struct vlan_info *vlan_info;
302 	struct vlan_vid_info *vid_info;
303 
304 	ASSERT_RTNL();
305 
306 	vlan_info = rtnl_dereference(dev->vlan_info);
307 	if (!vlan_info)
308 		return;
309 
310 	vid_info = vlan_vid_info_get(vlan_info, vid);
311 	if (!vid_info)
312 		return;
313 	vid_info->refcount--;
314 	if (vid_info->refcount == 0) {
315 		__vlan_vid_del(vlan_info, vid_info);
316 		if (vlan_info->nr_vids == 0) {
317 			RCU_INIT_POINTER(dev->vlan_info, NULL);
318 			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
319 		}
320 	}
321 }
322 EXPORT_SYMBOL(vlan_vid_del);
323 
324 int vlan_vids_add_by_dev(struct net_device *dev,
325 			 const struct net_device *by_dev)
326 {
327 	struct vlan_vid_info *vid_info;
328 	struct vlan_info *vlan_info;
329 	int err;
330 
331 	ASSERT_RTNL();
332 
333 	vlan_info = rtnl_dereference(by_dev->vlan_info);
334 	if (!vlan_info)
335 		return 0;
336 
337 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
338 		err = vlan_vid_add(dev, vid_info->vid);
339 		if (err)
340 			goto unwind;
341 	}
342 	return 0;
343 
344 unwind:
345 	list_for_each_entry_continue_reverse(vid_info,
346 					     &vlan_info->vid_list,
347 					     list) {
348 		vlan_vid_del(dev, vid_info->vid);
349 	}
350 
351 	return err;
352 }
353 EXPORT_SYMBOL(vlan_vids_add_by_dev);
354 
355 void vlan_vids_del_by_dev(struct net_device *dev,
356 			  const struct net_device *by_dev)
357 {
358 	struct vlan_vid_info *vid_info;
359 	struct vlan_info *vlan_info;
360 
361 	ASSERT_RTNL();
362 
363 	vlan_info = rtnl_dereference(by_dev->vlan_info);
364 	if (!vlan_info)
365 		return;
366 
367 	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
368 		vlan_vid_del(dev, vid_info->vid);
369 }
370 EXPORT_SYMBOL(vlan_vids_del_by_dev);
371