xref: /openbmc/linux/net/8021q/vlan_core.c (revision afb46f79)
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(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 	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 		return NULL;
119 	memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
120 	skb->mac_header += VLAN_HLEN;
121 	return skb;
122 }
123 
124 struct sk_buff *vlan_untag(struct sk_buff *skb)
125 {
126 	struct vlan_hdr *vhdr;
127 	u16 vlan_tci;
128 
129 	if (unlikely(vlan_tx_tag_present(skb))) {
130 		/* vlan_tci is already set-up so leave this for another time */
131 		return skb;
132 	}
133 
134 	skb = skb_share_check(skb, GFP_ATOMIC);
135 	if (unlikely(!skb))
136 		goto err_free;
137 
138 	if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
139 		goto err_free;
140 
141 	vhdr = (struct vlan_hdr *) skb->data;
142 	vlan_tci = ntohs(vhdr->h_vlan_TCI);
143 	__vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
144 
145 	skb_pull_rcsum(skb, VLAN_HLEN);
146 	vlan_set_encap_proto(skb, vhdr);
147 
148 	skb = vlan_reorder_header(skb);
149 	if (unlikely(!skb))
150 		goto err_free;
151 
152 	skb_reset_network_header(skb);
153 	skb_reset_transport_header(skb);
154 	skb_reset_mac_len(skb);
155 
156 	return skb;
157 
158 err_free:
159 	kfree_skb(skb);
160 	return NULL;
161 }
162 EXPORT_SYMBOL(vlan_untag);
163 
164 
165 /*
166  * vlan info and vid list
167  */
168 
169 static void vlan_group_free(struct vlan_group *grp)
170 {
171 	int i, j;
172 
173 	for (i = 0; i < VLAN_PROTO_NUM; i++)
174 		for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
175 			kfree(grp->vlan_devices_arrays[i][j]);
176 }
177 
178 static void vlan_info_free(struct vlan_info *vlan_info)
179 {
180 	vlan_group_free(&vlan_info->grp);
181 	kfree(vlan_info);
182 }
183 
184 static void vlan_info_rcu_free(struct rcu_head *rcu)
185 {
186 	vlan_info_free(container_of(rcu, struct vlan_info, rcu));
187 }
188 
189 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
190 {
191 	struct vlan_info *vlan_info;
192 
193 	vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
194 	if (!vlan_info)
195 		return NULL;
196 
197 	vlan_info->real_dev = dev;
198 	INIT_LIST_HEAD(&vlan_info->vid_list);
199 	return vlan_info;
200 }
201 
202 struct vlan_vid_info {
203 	struct list_head list;
204 	__be16 proto;
205 	u16 vid;
206 	int refcount;
207 };
208 
209 static bool vlan_hw_filter_capable(const struct net_device *dev,
210 				     const struct vlan_vid_info *vid_info)
211 {
212 	if (vid_info->proto == htons(ETH_P_8021Q) &&
213 	    dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
214 		return true;
215 	if (vid_info->proto == htons(ETH_P_8021AD) &&
216 	    dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
217 		return true;
218 	return false;
219 }
220 
221 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
222 					       __be16 proto, u16 vid)
223 {
224 	struct vlan_vid_info *vid_info;
225 
226 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
227 		if (vid_info->proto == proto && vid_info->vid == vid)
228 			return vid_info;
229 	}
230 	return NULL;
231 }
232 
233 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
234 {
235 	struct vlan_vid_info *vid_info;
236 
237 	vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
238 	if (!vid_info)
239 		return NULL;
240 	vid_info->proto = proto;
241 	vid_info->vid = vid;
242 
243 	return vid_info;
244 }
245 
246 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
247 			  struct vlan_vid_info **pvid_info)
248 {
249 	struct net_device *dev = vlan_info->real_dev;
250 	const struct net_device_ops *ops = dev->netdev_ops;
251 	struct vlan_vid_info *vid_info;
252 	int err;
253 
254 	vid_info = vlan_vid_info_alloc(proto, vid);
255 	if (!vid_info)
256 		return -ENOMEM;
257 
258 	if (vlan_hw_filter_capable(dev, vid_info)) {
259 		err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
260 		if (err) {
261 			kfree(vid_info);
262 			return err;
263 		}
264 	}
265 	list_add(&vid_info->list, &vlan_info->vid_list);
266 	vlan_info->nr_vids++;
267 	*pvid_info = vid_info;
268 	return 0;
269 }
270 
271 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
272 {
273 	struct vlan_info *vlan_info;
274 	struct vlan_vid_info *vid_info;
275 	bool vlan_info_created = false;
276 	int err;
277 
278 	ASSERT_RTNL();
279 
280 	vlan_info = rtnl_dereference(dev->vlan_info);
281 	if (!vlan_info) {
282 		vlan_info = vlan_info_alloc(dev);
283 		if (!vlan_info)
284 			return -ENOMEM;
285 		vlan_info_created = true;
286 	}
287 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
288 	if (!vid_info) {
289 		err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
290 		if (err)
291 			goto out_free_vlan_info;
292 	}
293 	vid_info->refcount++;
294 
295 	if (vlan_info_created)
296 		rcu_assign_pointer(dev->vlan_info, vlan_info);
297 
298 	return 0;
299 
300 out_free_vlan_info:
301 	if (vlan_info_created)
302 		kfree(vlan_info);
303 	return err;
304 }
305 EXPORT_SYMBOL(vlan_vid_add);
306 
307 static void __vlan_vid_del(struct vlan_info *vlan_info,
308 			   struct vlan_vid_info *vid_info)
309 {
310 	struct net_device *dev = vlan_info->real_dev;
311 	const struct net_device_ops *ops = dev->netdev_ops;
312 	__be16 proto = vid_info->proto;
313 	u16 vid = vid_info->vid;
314 	int err;
315 
316 	if (vlan_hw_filter_capable(dev, vid_info)) {
317 		err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
318 		if (err) {
319 			pr_warn("failed to kill vid %04x/%d for device %s\n",
320 				proto, vid, dev->name);
321 		}
322 	}
323 	list_del(&vid_info->list);
324 	kfree(vid_info);
325 	vlan_info->nr_vids--;
326 }
327 
328 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
329 {
330 	struct vlan_info *vlan_info;
331 	struct vlan_vid_info *vid_info;
332 
333 	ASSERT_RTNL();
334 
335 	vlan_info = rtnl_dereference(dev->vlan_info);
336 	if (!vlan_info)
337 		return;
338 
339 	vid_info = vlan_vid_info_get(vlan_info, proto, vid);
340 	if (!vid_info)
341 		return;
342 	vid_info->refcount--;
343 	if (vid_info->refcount == 0) {
344 		__vlan_vid_del(vlan_info, vid_info);
345 		if (vlan_info->nr_vids == 0) {
346 			RCU_INIT_POINTER(dev->vlan_info, NULL);
347 			call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
348 		}
349 	}
350 }
351 EXPORT_SYMBOL(vlan_vid_del);
352 
353 int vlan_vids_add_by_dev(struct net_device *dev,
354 			 const struct net_device *by_dev)
355 {
356 	struct vlan_vid_info *vid_info;
357 	struct vlan_info *vlan_info;
358 	int err;
359 
360 	ASSERT_RTNL();
361 
362 	vlan_info = rtnl_dereference(by_dev->vlan_info);
363 	if (!vlan_info)
364 		return 0;
365 
366 	list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
367 		err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
368 		if (err)
369 			goto unwind;
370 	}
371 	return 0;
372 
373 unwind:
374 	list_for_each_entry_continue_reverse(vid_info,
375 					     &vlan_info->vid_list,
376 					     list) {
377 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
378 	}
379 
380 	return err;
381 }
382 EXPORT_SYMBOL(vlan_vids_add_by_dev);
383 
384 void vlan_vids_del_by_dev(struct net_device *dev,
385 			  const struct net_device *by_dev)
386 {
387 	struct vlan_vid_info *vid_info;
388 	struct vlan_info *vlan_info;
389 
390 	ASSERT_RTNL();
391 
392 	vlan_info = rtnl_dereference(by_dev->vlan_info);
393 	if (!vlan_info)
394 		return;
395 
396 	list_for_each_entry(vid_info, &vlan_info->vid_list, list)
397 		vlan_vid_del(dev, vid_info->proto, vid_info->vid);
398 }
399 EXPORT_SYMBOL(vlan_vids_del_by_dev);
400 
401 bool vlan_uses_dev(const struct net_device *dev)
402 {
403 	struct vlan_info *vlan_info;
404 
405 	ASSERT_RTNL();
406 
407 	vlan_info = rtnl_dereference(dev->vlan_info);
408 	if (!vlan_info)
409 		return false;
410 	return vlan_info->grp.nr_vlan_devs ? true : false;
411 }
412 EXPORT_SYMBOL(vlan_uses_dev);
413