xref: /openbmc/linux/net/bridge/br_vlan.c (revision 1c2f87c2)
1 #include <linux/kernel.h>
2 #include <linux/netdevice.h>
3 #include <linux/rtnetlink.h>
4 #include <linux/slab.h>
5 
6 #include "br_private.h"
7 
8 static void __vlan_add_pvid(struct net_port_vlans *v, u16 vid)
9 {
10 	if (v->pvid == vid)
11 		return;
12 
13 	smp_wmb();
14 	v->pvid = vid;
15 }
16 
17 static void __vlan_delete_pvid(struct net_port_vlans *v, u16 vid)
18 {
19 	if (v->pvid != vid)
20 		return;
21 
22 	smp_wmb();
23 	v->pvid = 0;
24 }
25 
26 static void __vlan_add_flags(struct net_port_vlans *v, u16 vid, u16 flags)
27 {
28 	if (flags & BRIDGE_VLAN_INFO_PVID)
29 		__vlan_add_pvid(v, vid);
30 
31 	if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
32 		set_bit(vid, v->untagged_bitmap);
33 }
34 
35 static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
36 {
37 	struct net_bridge_port *p = NULL;
38 	struct net_bridge *br;
39 	struct net_device *dev;
40 	int err;
41 
42 	if (test_bit(vid, v->vlan_bitmap)) {
43 		__vlan_add_flags(v, vid, flags);
44 		return 0;
45 	}
46 
47 	if (v->port_idx) {
48 		p = v->parent.port;
49 		br = p->br;
50 		dev = p->dev;
51 	} else {
52 		br = v->parent.br;
53 		dev = br->dev;
54 	}
55 
56 	if (p) {
57 		/* Add VLAN to the device filter if it is supported.
58 		 * Stricly speaking, this is not necessary now, since
59 		 * devices are made promiscuous by the bridge, but if
60 		 * that ever changes this code will allow tagged
61 		 * traffic to enter the bridge.
62 		 */
63 		err = vlan_vid_add(dev, htons(ETH_P_8021Q), vid);
64 		if (err)
65 			return err;
66 	}
67 
68 	err = br_fdb_insert(br, p, dev->dev_addr, vid);
69 	if (err) {
70 		br_err(br, "failed insert local address into bridge "
71 		       "forwarding table\n");
72 		goto out_filt;
73 	}
74 
75 	set_bit(vid, v->vlan_bitmap);
76 	v->num_vlans++;
77 	__vlan_add_flags(v, vid, flags);
78 
79 	return 0;
80 
81 out_filt:
82 	if (p)
83 		vlan_vid_del(dev, htons(ETH_P_8021Q), vid);
84 	return err;
85 }
86 
87 static int __vlan_del(struct net_port_vlans *v, u16 vid)
88 {
89 	if (!test_bit(vid, v->vlan_bitmap))
90 		return -EINVAL;
91 
92 	__vlan_delete_pvid(v, vid);
93 	clear_bit(vid, v->untagged_bitmap);
94 
95 	if (v->port_idx)
96 		vlan_vid_del(v->parent.port->dev, htons(ETH_P_8021Q), vid);
97 
98 	clear_bit(vid, v->vlan_bitmap);
99 	v->num_vlans--;
100 	if (bitmap_empty(v->vlan_bitmap, VLAN_N_VID)) {
101 		if (v->port_idx)
102 			RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
103 		else
104 			RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
105 		kfree_rcu(v, rcu);
106 	}
107 	return 0;
108 }
109 
110 static void __vlan_flush(struct net_port_vlans *v)
111 {
112 	smp_wmb();
113 	v->pvid = 0;
114 	bitmap_zero(v->vlan_bitmap, VLAN_N_VID);
115 	if (v->port_idx)
116 		RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
117 	else
118 		RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
119 	kfree_rcu(v, rcu);
120 }
121 
122 struct sk_buff *br_handle_vlan(struct net_bridge *br,
123 			       const struct net_port_vlans *pv,
124 			       struct sk_buff *skb)
125 {
126 	u16 vid;
127 
128 	if (!br->vlan_enabled)
129 		goto out;
130 
131 	/* Vlan filter table must be configured at this point.  The
132 	 * only exception is the bridge is set in promisc mode and the
133 	 * packet is destined for the bridge device.  In this case
134 	 * pass the packet as is.
135 	 */
136 	if (!pv) {
137 		if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) {
138 			goto out;
139 		} else {
140 			kfree_skb(skb);
141 			return NULL;
142 		}
143 	}
144 
145 	/* At this point, we know that the frame was filtered and contains
146 	 * a valid vlan id.  If the vlan id is set in the untagged bitmap,
147 	 * send untagged; otherwise, send tagged.
148 	 */
149 	br_vlan_get_tag(skb, &vid);
150 	if (test_bit(vid, pv->untagged_bitmap))
151 		skb->vlan_tci = 0;
152 
153 out:
154 	return skb;
155 }
156 
157 /* Called under RCU */
158 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
159 			struct sk_buff *skb, u16 *vid)
160 {
161 	int err;
162 
163 	/* If VLAN filtering is disabled on the bridge, all packets are
164 	 * permitted.
165 	 */
166 	if (!br->vlan_enabled)
167 		return true;
168 
169 	/* If there are no vlan in the permitted list, all packets are
170 	 * rejected.
171 	 */
172 	if (!v)
173 		goto drop;
174 
175 	/* If vlan tx offload is disabled on bridge device and frame was
176 	 * sent from vlan device on the bridge device, it does not have
177 	 * HW accelerated vlan tag.
178 	 */
179 	if (unlikely(!vlan_tx_tag_present(skb) &&
180 		     (skb->protocol == htons(ETH_P_8021Q) ||
181 		      skb->protocol == htons(ETH_P_8021AD)))) {
182 		skb = vlan_untag(skb);
183 		if (unlikely(!skb))
184 			return false;
185 	}
186 
187 	err = br_vlan_get_tag(skb, vid);
188 	if (!*vid) {
189 		u16 pvid = br_get_pvid(v);
190 
191 		/* Frame had a tag with VID 0 or did not have a tag.
192 		 * See if pvid is set on this port.  That tells us which
193 		 * vlan untagged or priority-tagged traffic belongs to.
194 		 */
195 		if (pvid == VLAN_N_VID)
196 			goto drop;
197 
198 		/* PVID is set on this port.  Any untagged or priority-tagged
199 		 * ingress frame is considered to belong to this vlan.
200 		 */
201 		*vid = pvid;
202 		if (likely(err))
203 			/* Untagged Frame. */
204 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
205 		else
206 			/* Priority-tagged Frame.
207 			 * At this point, We know that skb->vlan_tci had
208 			 * VLAN_TAG_PRESENT bit and its VID field was 0x000.
209 			 * We update only VID field and preserve PCP field.
210 			 */
211 			skb->vlan_tci |= pvid;
212 
213 		return true;
214 	}
215 
216 	/* Frame had a valid vlan tag.  See if vlan is allowed */
217 	if (test_bit(*vid, v->vlan_bitmap))
218 		return true;
219 drop:
220 	kfree_skb(skb);
221 	return false;
222 }
223 
224 /* Called under RCU. */
225 bool br_allowed_egress(struct net_bridge *br,
226 		       const struct net_port_vlans *v,
227 		       const struct sk_buff *skb)
228 {
229 	u16 vid;
230 
231 	if (!br->vlan_enabled)
232 		return true;
233 
234 	if (!v)
235 		return false;
236 
237 	br_vlan_get_tag(skb, &vid);
238 	if (test_bit(vid, v->vlan_bitmap))
239 		return true;
240 
241 	return false;
242 }
243 
244 /* Must be protected by RTNL.
245  * Must be called with vid in range from 1 to 4094 inclusive.
246  */
247 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
248 {
249 	struct net_port_vlans *pv = NULL;
250 	int err;
251 
252 	ASSERT_RTNL();
253 
254 	pv = rtnl_dereference(br->vlan_info);
255 	if (pv)
256 		return __vlan_add(pv, vid, flags);
257 
258 	/* Create port vlan infomration
259 	 */
260 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
261 	if (!pv)
262 		return -ENOMEM;
263 
264 	pv->parent.br = br;
265 	err = __vlan_add(pv, vid, flags);
266 	if (err)
267 		goto out;
268 
269 	rcu_assign_pointer(br->vlan_info, pv);
270 	return 0;
271 out:
272 	kfree(pv);
273 	return err;
274 }
275 
276 /* Must be protected by RTNL.
277  * Must be called with vid in range from 1 to 4094 inclusive.
278  */
279 int br_vlan_delete(struct net_bridge *br, u16 vid)
280 {
281 	struct net_port_vlans *pv;
282 
283 	ASSERT_RTNL();
284 
285 	pv = rtnl_dereference(br->vlan_info);
286 	if (!pv)
287 		return -EINVAL;
288 
289 	br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
290 
291 	__vlan_del(pv, vid);
292 	return 0;
293 }
294 
295 void br_vlan_flush(struct net_bridge *br)
296 {
297 	struct net_port_vlans *pv;
298 
299 	ASSERT_RTNL();
300 	pv = rtnl_dereference(br->vlan_info);
301 	if (!pv)
302 		return;
303 
304 	__vlan_flush(pv);
305 }
306 
307 bool br_vlan_find(struct net_bridge *br, u16 vid)
308 {
309 	struct net_port_vlans *pv;
310 	bool found = false;
311 
312 	rcu_read_lock();
313 	pv = rcu_dereference(br->vlan_info);
314 
315 	if (!pv)
316 		goto out;
317 
318 	if (test_bit(vid, pv->vlan_bitmap))
319 		found = true;
320 
321 out:
322 	rcu_read_unlock();
323 	return found;
324 }
325 
326 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
327 {
328 	if (!rtnl_trylock())
329 		return restart_syscall();
330 
331 	if (br->vlan_enabled == val)
332 		goto unlock;
333 
334 	br->vlan_enabled = val;
335 
336 unlock:
337 	rtnl_unlock();
338 	return 0;
339 }
340 
341 /* Must be protected by RTNL.
342  * Must be called with vid in range from 1 to 4094 inclusive.
343  */
344 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
345 {
346 	struct net_port_vlans *pv = NULL;
347 	int err;
348 
349 	ASSERT_RTNL();
350 
351 	pv = rtnl_dereference(port->vlan_info);
352 	if (pv)
353 		return __vlan_add(pv, vid, flags);
354 
355 	/* Create port vlan infomration
356 	 */
357 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
358 	if (!pv) {
359 		err = -ENOMEM;
360 		goto clean_up;
361 	}
362 
363 	pv->port_idx = port->port_no;
364 	pv->parent.port = port;
365 	err = __vlan_add(pv, vid, flags);
366 	if (err)
367 		goto clean_up;
368 
369 	rcu_assign_pointer(port->vlan_info, pv);
370 	return 0;
371 
372 clean_up:
373 	kfree(pv);
374 	return err;
375 }
376 
377 /* Must be protected by RTNL.
378  * Must be called with vid in range from 1 to 4094 inclusive.
379  */
380 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
381 {
382 	struct net_port_vlans *pv;
383 
384 	ASSERT_RTNL();
385 
386 	pv = rtnl_dereference(port->vlan_info);
387 	if (!pv)
388 		return -EINVAL;
389 
390 	br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
391 
392 	return __vlan_del(pv, vid);
393 }
394 
395 void nbp_vlan_flush(struct net_bridge_port *port)
396 {
397 	struct net_port_vlans *pv;
398 	u16 vid;
399 
400 	ASSERT_RTNL();
401 
402 	pv = rtnl_dereference(port->vlan_info);
403 	if (!pv)
404 		return;
405 
406 	for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
407 		vlan_vid_del(port->dev, htons(ETH_P_8021Q), vid);
408 
409 	__vlan_flush(pv);
410 }
411 
412 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
413 {
414 	struct net_port_vlans *pv;
415 	bool found = false;
416 
417 	rcu_read_lock();
418 	pv = rcu_dereference(port->vlan_info);
419 
420 	if (!pv)
421 		goto out;
422 
423 	if (test_bit(vid, pv->vlan_bitmap))
424 		found = true;
425 
426 out:
427 	rcu_read_unlock();
428 	return found;
429 }
430