xref: /openbmc/linux/net/8021q/vlan_core.c (revision 63dc02bd)
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 (!compare_ether_addr(eth_hdr(skb)->h_dest,
35 					vlan_dev->dev_addr))
36 			skb->pkt_type = PACKET_HOST;
37 	}
38 
39 	if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
40 		unsigned int offset = skb->data - skb_mac_header(skb);
41 
42 		/*
43 		 * vlan_insert_tag expect skb->data pointing to mac header.
44 		 * So change skb->data before calling it and change back to
45 		 * original position later
46 		 */
47 		skb_push(skb, offset);
48 		skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci);
49 		if (!skb)
50 			return false;
51 		skb_pull(skb, offset + VLAN_HLEN);
52 		skb_reset_mac_len(skb);
53 	}
54 
55 	skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
56 	skb->vlan_tci = 0;
57 
58 	rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
59 
60 	u64_stats_update_begin(&rx_stats->syncp);
61 	rx_stats->rx_packets++;
62 	rx_stats->rx_bytes += skb->len;
63 	if (skb->pkt_type == PACKET_MULTICAST)
64 		rx_stats->rx_multicast++;
65 	u64_stats_update_end(&rx_stats->syncp);
66 
67 	return true;
68 }
69 
70 /* Must be invoked with rcu_read_lock or with RTNL. */
71 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
72 					u16 vlan_id)
73 {
74 	struct vlan_info *vlan_info = rcu_dereference_rtnl(real_dev->vlan_info);
75 
76 	if (vlan_info) {
77 		return vlan_group_get_device(&vlan_info->grp, vlan_id);
78 	} else {
79 		/*
80 		 * Bonding slaves do not have grp assigned to themselves.
81 		 * Grp is assigned to bonding master instead.
82 		 */
83 		if (netif_is_bond_slave(real_dev))
84 			return __vlan_find_dev_deep(real_dev->master, vlan_id);
85 	}
86 
87 	return NULL;
88 }
89 EXPORT_SYMBOL(__vlan_find_dev_deep);
90 
91 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
92 {
93 	return vlan_dev_priv(dev)->real_dev;
94 }
95 EXPORT_SYMBOL(vlan_dev_real_dev);
96 
97 u16 vlan_dev_vlan_id(const struct net_device *dev)
98 {
99 	return vlan_dev_priv(dev)->vlan_id;
100 }
101 EXPORT_SYMBOL(vlan_dev_vlan_id);
102 
103 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
104 {
105 	if (skb_cow(skb, skb_headroom(skb)) < 0)
106 		return NULL;
107 	memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
108 	skb->mac_header += VLAN_HLEN;
109 	skb_reset_mac_len(skb);
110 	return skb;
111 }
112 
113 struct sk_buff *vlan_untag(struct sk_buff *skb)
114 {
115 	struct vlan_hdr *vhdr;
116 	u16 vlan_tci;
117 
118 	if (unlikely(vlan_tx_tag_present(skb))) {
119 		/* vlan_tci is already set-up so leave this for another time */
120 		return skb;
121 	}
122 
123 	skb = skb_share_check(skb, GFP_ATOMIC);
124 	if (unlikely(!skb))
125 		goto err_free;
126 
127 	if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
128 		goto err_free;
129 
130 	vhdr = (struct vlan_hdr *) skb->data;
131 	vlan_tci = ntohs(vhdr->h_vlan_TCI);
132 	__vlan_hwaccel_put_tag(skb, vlan_tci);
133 
134 	skb_pull_rcsum(skb, VLAN_HLEN);
135 	vlan_set_encap_proto(skb, vhdr);
136 
137 	skb = vlan_reorder_header(skb);
138 	if (unlikely(!skb))
139 		goto err_free;
140 
141 	skb_reset_network_header(skb);
142 	skb_reset_transport_header(skb);
143 	return skb;
144 
145 err_free:
146 	kfree_skb(skb);
147 	return NULL;
148 }
149 
150 
151 /*
152  * vlan info and vid list
153  */
154 
155 static void vlan_group_free(struct vlan_group *grp)
156 {
157 	int i;
158 
159 	for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
160 		kfree(grp->vlan_devices_arrays[i]);
161 }
162 
163 static void vlan_info_free(struct vlan_info *vlan_info)
164 {
165 	vlan_group_free(&vlan_info->grp);
166 	kfree(vlan_info);
167 }
168 
169 static void vlan_info_rcu_free(struct rcu_head *rcu)
170 {
171 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
172 }
173 
174 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
175 {
176 	struct vlan_info *vlan_info;
177 
178 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
179 	if (!vlan_info)
180 		return NULL;
181 
182 	vlan_info->real_dev = dev;
183 	INIT_LIST_HEAD(&vlan_info->vid_list);
184 	return vlan_info;
185 }
186 
187 struct vlan_vid_info {
188 	struct list_head list;
189 	unsigned short vid;
190 	int refcount;
191 };
192 
193 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
194 					       unsigned short vid)
195 {
196 	struct vlan_vid_info *vid_info;
197 
198 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
199 		if (vid_info->vid == vid)
200 			return vid_info;
201 	}
202 	return NULL;
203 }
204 
205 static struct vlan_vid_info *vlan_vid_info_alloc(unsigned short vid)
206 {
207 	struct vlan_vid_info *vid_info;
208 
209 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
210 	if (!vid_info)
211 		return NULL;
212 	vid_info->vid = vid;
213 
214 	return vid_info;
215 }
216 
217 static int __vlan_vid_add(struct vlan_info *vlan_info, unsigned short vid,
218 			  struct vlan_vid_info **pvid_info)
219 {
220 	struct net_device *dev = vlan_info->real_dev;
221 	const struct net_device_ops *ops = dev->netdev_ops;
222 	struct vlan_vid_info *vid_info;
223 	int err;
224 
225 	vid_info = vlan_vid_info_alloc(vid);
226 	if (!vid_info)
227 		return -ENOMEM;
228 
229 	if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
230 	    ops->ndo_vlan_rx_add_vid) {
231 		err =  ops->ndo_vlan_rx_add_vid(dev, vid);
232 		if (err) {
233 			kfree(vid_info);
234 			return err;
235 		}
236 	}
237 	list_add(&vid_info->list, &vlan_info->vid_list);
238 	vlan_info->nr_vids++;
239 	*pvid_info = vid_info;
240 	return 0;
241 }
242 
243 int vlan_vid_add(struct net_device *dev, unsigned short vid)
244 {
245 	struct vlan_info *vlan_info;
246 	struct vlan_vid_info *vid_info;
247 	bool vlan_info_created = false;
248 	int err;
249 
250 	ASSERT_RTNL();
251 
252 	vlan_info = rtnl_dereference(dev->vlan_info);
253 	if (!vlan_info) {
254 		vlan_info = vlan_info_alloc(dev);
255 		if (!vlan_info)
256 			return -ENOMEM;
257 		vlan_info_created = true;
258 	}
259 	vid_info = vlan_vid_info_get(vlan_info, vid);
260 	if (!vid_info) {
261 		err = __vlan_vid_add(vlan_info, vid, &vid_info);
262 		if (err)
263 			goto out_free_vlan_info;
264 	}
265 	vid_info->refcount++;
266 
267 	if (vlan_info_created)
268 		rcu_assign_pointer(dev->vlan_info, vlan_info);
269 
270 	return 0;
271 
272 out_free_vlan_info:
273 	if (vlan_info_created)
274 		kfree(vlan_info);
275 	return err;
276 }
277 EXPORT_SYMBOL(vlan_vid_add);
278 
279 static void __vlan_vid_del(struct vlan_info *vlan_info,
280 			   struct vlan_vid_info *vid_info)
281 {
282 	struct net_device *dev = vlan_info->real_dev;
283 	const struct net_device_ops *ops = dev->netdev_ops;
284 	unsigned short vid = vid_info->vid;
285 	int err;
286 
287 	if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
288 	     ops->ndo_vlan_rx_kill_vid) {
289 		err = ops->ndo_vlan_rx_kill_vid(dev, vid);
290 		if (err) {
291 			pr_warn("failed to kill vid %d for device %s\n",
292 				vid, dev->name);
293 		}
294 	}
295 	list_del(&vid_info->list);
296 	kfree(vid_info);
297 	vlan_info->nr_vids--;
298 }
299 
300 void vlan_vid_del(struct net_device *dev, unsigned short vid)
301 {
302 	struct vlan_info *vlan_info;
303 	struct vlan_vid_info *vid_info;
304 
305 	ASSERT_RTNL();
306 
307 	vlan_info = rtnl_dereference(dev->vlan_info);
308 	if (!vlan_info)
309 		return;
310 
311 	vid_info = vlan_vid_info_get(vlan_info, vid);
312 	if (!vid_info)
313 		return;
314 	vid_info->refcount--;
315 	if (vid_info->refcount == 0) {
316 		__vlan_vid_del(vlan_info, vid_info);
317 		if (vlan_info->nr_vids == 0) {
318 			RCU_INIT_POINTER(dev->vlan_info, NULL);
319 			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
320 		}
321 	}
322 }
323 EXPORT_SYMBOL(vlan_vid_del);
324 
325 int vlan_vids_add_by_dev(struct net_device *dev,
326 			 const struct net_device *by_dev)
327 {
328 	struct vlan_vid_info *vid_info;
329 	struct vlan_info *vlan_info;
330 	int err;
331 
332 	ASSERT_RTNL();
333 
334 	vlan_info = rtnl_dereference(by_dev->vlan_info);
335 	if (!vlan_info)
336 		return 0;
337 
338 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
339 		err = vlan_vid_add(dev, vid_info->vid);
340 		if (err)
341 			goto unwind;
342 	}
343 	return 0;
344 
345 unwind:
346 	list_for_each_entry_continue_reverse(vid_info,
347 					     &vlan_info->vid_list,
348 					     list) {
349 		vlan_vid_del(dev, vid_info->vid);
350 	}
351 
352 	return err;
353 }
354 EXPORT_SYMBOL(vlan_vids_add_by_dev);
355 
356 void vlan_vids_del_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 
362 	ASSERT_RTNL();
363 
364 	vlan_info = rtnl_dereference(by_dev->vlan_info);
365 	if (!vlan_info)
366 		return;
367 
368 	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
369 		vlan_vid_del(dev, vid_info->vid);
370 }
371 EXPORT_SYMBOL(vlan_vids_del_by_dev);
372