xref: /openbmc/linux/net/8021q/vlan_core.c (revision ee89bd6b)
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_tci & VLAN_VID_MASK;
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 (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(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(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(upper_dev,
85 						    vlan_proto, vlan_id);
86 	}
87 
88 	return NULL;
89 }
90 EXPORT_SYMBOL(__vlan_find_dev_deep);
91 
92 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
93 {
94 	return vlan_dev_priv(dev)->real_dev;
95 }
96 EXPORT_SYMBOL(vlan_dev_real_dev);
97 
98 u16 vlan_dev_vlan_id(const struct net_device *dev)
99 {
100 	return vlan_dev_priv(dev)->vlan_id;
101 }
102 EXPORT_SYMBOL(vlan_dev_vlan_id);
103 
104 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
105 {
106 	if (skb_cow(skb, skb_headroom(skb)) < 0)
107 		return NULL;
108 	memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
109 	skb->mac_header += VLAN_HLEN;
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, skb->protocol, 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 	skb_reset_mac_len(skb);
144 
145 	return skb;
146 
147 err_free:
148 	kfree_skb(skb);
149 	return NULL;
150 }
151 EXPORT_SYMBOL(vlan_untag);
152 
153 
154 /*
155  * vlan info and vid list
156  */
157 
158 static void vlan_group_free(struct vlan_group *grp)
159 {
160 	int i, j;
161 
162 	for (i = 0; i < VLAN_PROTO_NUM; i++)
163 		for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
164 			kfree(grp->vlan_devices_arrays[i][j]);
165 }
166 
167 static void vlan_info_free(struct vlan_info *vlan_info)
168 {
169 	vlan_group_free(&vlan_info->grp);
170 	kfree(vlan_info);
171 }
172 
173 static void vlan_info_rcu_free(struct rcu_head *rcu)
174 {
175 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
176 }
177 
178 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
179 {
180 	struct vlan_info *vlan_info;
181 
182 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
183 	if (!vlan_info)
184 		return NULL;
185 
186 	vlan_info->real_dev = dev;
187 	INIT_LIST_HEAD(&vlan_info->vid_list);
188 	return vlan_info;
189 }
190 
191 struct vlan_vid_info {
192 	struct list_head list;
193 	__be16 proto;
194 	u16 vid;
195 	int refcount;
196 };
197 
198 static bool vlan_hw_filter_capable(const struct net_device *dev,
199 				     const struct vlan_vid_info *vid_info)
200 {
201 	if (vid_info->proto == htons(ETH_P_8021Q) &&
202 	    dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
203 		return true;
204 	if (vid_info->proto == htons(ETH_P_8021AD) &&
205 	    dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
206 		return true;
207 	return false;
208 }
209 
210 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
211 					       __be16 proto, u16 vid)
212 {
213 	struct vlan_vid_info *vid_info;
214 
215 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
216 		if (vid_info->proto == proto && vid_info->vid == vid)
217 			return vid_info;
218 	}
219 	return NULL;
220 }
221 
222 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
223 {
224 	struct vlan_vid_info *vid_info;
225 
226 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
227 	if (!vid_info)
228 		return NULL;
229 	vid_info->proto = proto;
230 	vid_info->vid = vid;
231 
232 	return vid_info;
233 }
234 
235 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
236 			  struct vlan_vid_info **pvid_info)
237 {
238 	struct net_device *dev = vlan_info->real_dev;
239 	const struct net_device_ops *ops = dev->netdev_ops;
240 	struct vlan_vid_info *vid_info;
241 	int err;
242 
243 	vid_info = vlan_vid_info_alloc(proto, vid);
244 	if (!vid_info)
245 		return -ENOMEM;
246 
247 	if (vlan_hw_filter_capable(dev, vid_info)) {
248 		err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
249 		if (err) {
250 			kfree(vid_info);
251 			return err;
252 		}
253 	}
254 	list_add(&vid_info->list, &vlan_info->vid_list);
255 	vlan_info->nr_vids++;
256 	*pvid_info = vid_info;
257 	return 0;
258 }
259 
260 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
261 {
262 	struct vlan_info *vlan_info;
263 	struct vlan_vid_info *vid_info;
264 	bool vlan_info_created = false;
265 	int err;
266 
267 	ASSERT_RTNL();
268 
269 	vlan_info = rtnl_dereference(dev->vlan_info);
270 	if (!vlan_info) {
271 		vlan_info = vlan_info_alloc(dev);
272 		if (!vlan_info)
273 			return -ENOMEM;
274 		vlan_info_created = true;
275 	}
276 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
277 	if (!vid_info) {
278 		err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
279 		if (err)
280 			goto out_free_vlan_info;
281 	}
282 	vid_info->refcount++;
283 
284 	if (vlan_info_created)
285 		rcu_assign_pointer(dev->vlan_info, vlan_info);
286 
287 	return 0;
288 
289 out_free_vlan_info:
290 	if (vlan_info_created)
291 		kfree(vlan_info);
292 	return err;
293 }
294 EXPORT_SYMBOL(vlan_vid_add);
295 
296 static void __vlan_vid_del(struct vlan_info *vlan_info,
297 			   struct vlan_vid_info *vid_info)
298 {
299 	struct net_device *dev = vlan_info->real_dev;
300 	const struct net_device_ops *ops = dev->netdev_ops;
301 	__be16 proto = vid_info->proto;
302 	u16 vid = vid_info->vid;
303 	int err;
304 
305 	if (vlan_hw_filter_capable(dev, vid_info)) {
306 		err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
307 		if (err) {
308 			pr_warn("failed to kill vid %04x/%d for device %s\n",
309 				proto, vid, dev->name);
310 		}
311 	}
312 	list_del(&vid_info->list);
313 	kfree(vid_info);
314 	vlan_info->nr_vids--;
315 }
316 
317 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
318 {
319 	struct vlan_info *vlan_info;
320 	struct vlan_vid_info *vid_info;
321 
322 	ASSERT_RTNL();
323 
324 	vlan_info = rtnl_dereference(dev->vlan_info);
325 	if (!vlan_info)
326 		return;
327 
328 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
329 	if (!vid_info)
330 		return;
331 	vid_info->refcount--;
332 	if (vid_info->refcount == 0) {
333 		__vlan_vid_del(vlan_info, vid_info);
334 		if (vlan_info->nr_vids == 0) {
335 			RCU_INIT_POINTER(dev->vlan_info, NULL);
336 			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
337 		}
338 	}
339 }
340 EXPORT_SYMBOL(vlan_vid_del);
341 
342 int vlan_vids_add_by_dev(struct net_device *dev,
343 			 const struct net_device *by_dev)
344 {
345 	struct vlan_vid_info *vid_info;
346 	struct vlan_info *vlan_info;
347 	int err;
348 
349 	ASSERT_RTNL();
350 
351 	vlan_info = rtnl_dereference(by_dev->vlan_info);
352 	if (!vlan_info)
353 		return 0;
354 
355 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
356 		err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
357 		if (err)
358 			goto unwind;
359 	}
360 	return 0;
361 
362 unwind:
363 	list_for_each_entry_continue_reverse(vid_info,
364 					     &vlan_info->vid_list,
365 					     list) {
366 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
367 	}
368 
369 	return err;
370 }
371 EXPORT_SYMBOL(vlan_vids_add_by_dev);
372 
373 void vlan_vids_del_by_dev(struct net_device *dev,
374 			  const struct net_device *by_dev)
375 {
376 	struct vlan_vid_info *vid_info;
377 	struct vlan_info *vlan_info;
378 
379 	ASSERT_RTNL();
380 
381 	vlan_info = rtnl_dereference(by_dev->vlan_info);
382 	if (!vlan_info)
383 		return;
384 
385 	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
386 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
387 }
388 EXPORT_SYMBOL(vlan_vids_del_by_dev);
389 
390 bool vlan_uses_dev(const struct net_device *dev)
391 {
392 	struct vlan_info *vlan_info;
393 
394 	ASSERT_RTNL();
395 
396 	vlan_info = rtnl_dereference(dev->vlan_info);
397 	if (!vlan_info)
398 		return false;
399 	return vlan_info->grp.nr_vlan_devs ? true : false;
400 }
401 EXPORT_SYMBOL(vlan_uses_dev);
402