xref: /openbmc/linux/net/bridge/br_vlan.c (revision 930beb5a)
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_assign_pointer(v->parent.port->vlan_info, NULL);
103 		else
104 			rcu_assign_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_assign_pointer(v->parent.port->vlan_info, NULL);
117 	else
118 		rcu_assign_pointer(v->parent.br->vlan_info, NULL);
119 	kfree_rcu(v, rcu);
120 }
121 
122 /* Strip the tag from the packet.  Will return skb with tci set 0.  */
123 static struct sk_buff *br_vlan_untag(struct sk_buff *skb)
124 {
125 	if (skb->protocol != htons(ETH_P_8021Q)) {
126 		skb->vlan_tci = 0;
127 		return skb;
128 	}
129 
130 	skb->vlan_tci = 0;
131 	skb = vlan_untag(skb);
132 	if (skb)
133 		skb->vlan_tci = 0;
134 
135 	return skb;
136 }
137 
138 struct sk_buff *br_handle_vlan(struct net_bridge *br,
139 			       const struct net_port_vlans *pv,
140 			       struct sk_buff *skb)
141 {
142 	u16 vid;
143 
144 	if (!br->vlan_enabled)
145 		goto out;
146 
147 	/* At this point, we know that the frame was filtered and contains
148 	 * a valid vlan id.  If the vlan id is set in the untagged bitmap,
149 	 * send untagged; otherwise, send taged.
150 	 */
151 	br_vlan_get_tag(skb, &vid);
152 	if (test_bit(vid, pv->untagged_bitmap))
153 		skb = br_vlan_untag(skb);
154 	else {
155 		/* Egress policy says "send tagged".  If output device
156 		 * is the  bridge, we need to add the VLAN header
157 		 * ourselves since we'll be going through the RX path.
158 		 * Sending to ports puts the frame on the TX path and
159 		 * we let dev_hard_start_xmit() add the header.
160 		 */
161 		if (skb->protocol != htons(ETH_P_8021Q) &&
162 		    pv->port_idx == 0) {
163 			/* vlan_put_tag expects skb->data to point to
164 			 * mac header.
165 			 */
166 			skb_push(skb, ETH_HLEN);
167 			skb = __vlan_put_tag(skb, skb->vlan_proto, skb->vlan_tci);
168 			if (!skb)
169 				goto out;
170 			/* put skb->data back to where it was */
171 			skb_pull(skb, ETH_HLEN);
172 			skb->vlan_tci = 0;
173 		}
174 	}
175 
176 out:
177 	return skb;
178 }
179 
180 /* Called under RCU */
181 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
182 			struct sk_buff *skb, u16 *vid)
183 {
184 	int err;
185 
186 	/* If VLAN filtering is disabled on the bridge, all packets are
187 	 * permitted.
188 	 */
189 	if (!br->vlan_enabled)
190 		return true;
191 
192 	/* If there are no vlan in the permitted list, all packets are
193 	 * rejected.
194 	 */
195 	if (!v)
196 		return false;
197 
198 	err = br_vlan_get_tag(skb, vid);
199 	if (!*vid) {
200 		u16 pvid = br_get_pvid(v);
201 
202 		/* Frame had a tag with VID 0 or did not have a tag.
203 		 * See if pvid is set on this port.  That tells us which
204 		 * vlan untagged or priority-tagged traffic belongs to.
205 		 */
206 		if (pvid == VLAN_N_VID)
207 			return false;
208 
209 		/* PVID is set on this port.  Any untagged or priority-tagged
210 		 * ingress frame is considered to belong to this vlan.
211 		 */
212 		*vid = pvid;
213 		if (likely(err))
214 			/* Untagged Frame. */
215 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
216 		else
217 			/* Priority-tagged Frame.
218 			 * At this point, We know that skb->vlan_tci had
219 			 * VLAN_TAG_PRESENT bit and its VID field was 0x000.
220 			 * We update only VID field and preserve PCP field.
221 			 */
222 			skb->vlan_tci |= pvid;
223 
224 		return true;
225 	}
226 
227 	/* Frame had a valid vlan tag.  See if vlan is allowed */
228 	if (test_bit(*vid, v->vlan_bitmap))
229 		return true;
230 
231 	return false;
232 }
233 
234 /* Called under RCU. */
235 bool br_allowed_egress(struct net_bridge *br,
236 		       const struct net_port_vlans *v,
237 		       const struct sk_buff *skb)
238 {
239 	u16 vid;
240 
241 	if (!br->vlan_enabled)
242 		return true;
243 
244 	if (!v)
245 		return false;
246 
247 	br_vlan_get_tag(skb, &vid);
248 	if (test_bit(vid, v->vlan_bitmap))
249 		return true;
250 
251 	return false;
252 }
253 
254 /* Must be protected by RTNL.
255  * Must be called with vid in range from 1 to 4094 inclusive.
256  */
257 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
258 {
259 	struct net_port_vlans *pv = NULL;
260 	int err;
261 
262 	ASSERT_RTNL();
263 
264 	pv = rtnl_dereference(br->vlan_info);
265 	if (pv)
266 		return __vlan_add(pv, vid, flags);
267 
268 	/* Create port vlan infomration
269 	 */
270 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
271 	if (!pv)
272 		return -ENOMEM;
273 
274 	pv->parent.br = br;
275 	err = __vlan_add(pv, vid, flags);
276 	if (err)
277 		goto out;
278 
279 	rcu_assign_pointer(br->vlan_info, pv);
280 	return 0;
281 out:
282 	kfree(pv);
283 	return err;
284 }
285 
286 /* Must be protected by RTNL.
287  * Must be called with vid in range from 1 to 4094 inclusive.
288  */
289 int br_vlan_delete(struct net_bridge *br, u16 vid)
290 {
291 	struct net_port_vlans *pv;
292 
293 	ASSERT_RTNL();
294 
295 	pv = rtnl_dereference(br->vlan_info);
296 	if (!pv)
297 		return -EINVAL;
298 
299 	spin_lock_bh(&br->hash_lock);
300 	fdb_delete_by_addr(br, br->dev->dev_addr, vid);
301 	spin_unlock_bh(&br->hash_lock);
302 
303 	__vlan_del(pv, vid);
304 	return 0;
305 }
306 
307 void br_vlan_flush(struct net_bridge *br)
308 {
309 	struct net_port_vlans *pv;
310 
311 	ASSERT_RTNL();
312 	pv = rtnl_dereference(br->vlan_info);
313 	if (!pv)
314 		return;
315 
316 	__vlan_flush(pv);
317 }
318 
319 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
320 {
321 	if (!rtnl_trylock())
322 		return restart_syscall();
323 
324 	if (br->vlan_enabled == val)
325 		goto unlock;
326 
327 	br->vlan_enabled = val;
328 
329 unlock:
330 	rtnl_unlock();
331 	return 0;
332 }
333 
334 /* Must be protected by RTNL.
335  * Must be called with vid in range from 1 to 4094 inclusive.
336  */
337 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
338 {
339 	struct net_port_vlans *pv = NULL;
340 	int err;
341 
342 	ASSERT_RTNL();
343 
344 	pv = rtnl_dereference(port->vlan_info);
345 	if (pv)
346 		return __vlan_add(pv, vid, flags);
347 
348 	/* Create port vlan infomration
349 	 */
350 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
351 	if (!pv) {
352 		err = -ENOMEM;
353 		goto clean_up;
354 	}
355 
356 	pv->port_idx = port->port_no;
357 	pv->parent.port = port;
358 	err = __vlan_add(pv, vid, flags);
359 	if (err)
360 		goto clean_up;
361 
362 	rcu_assign_pointer(port->vlan_info, pv);
363 	return 0;
364 
365 clean_up:
366 	kfree(pv);
367 	return err;
368 }
369 
370 /* Must be protected by RTNL.
371  * Must be called with vid in range from 1 to 4094 inclusive.
372  */
373 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
374 {
375 	struct net_port_vlans *pv;
376 
377 	ASSERT_RTNL();
378 
379 	pv = rtnl_dereference(port->vlan_info);
380 	if (!pv)
381 		return -EINVAL;
382 
383 	spin_lock_bh(&port->br->hash_lock);
384 	fdb_delete_by_addr(port->br, port->dev->dev_addr, vid);
385 	spin_unlock_bh(&port->br->hash_lock);
386 
387 	return __vlan_del(pv, vid);
388 }
389 
390 void nbp_vlan_flush(struct net_bridge_port *port)
391 {
392 	struct net_port_vlans *pv;
393 	u16 vid;
394 
395 	ASSERT_RTNL();
396 
397 	pv = rtnl_dereference(port->vlan_info);
398 	if (!pv)
399 		return;
400 
401 	for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
402 		vlan_vid_del(port->dev, htons(ETH_P_8021Q), vid);
403 
404 	__vlan_flush(pv);
405 }
406 
407 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
408 {
409 	struct net_port_vlans *pv;
410 	bool found = false;
411 
412 	rcu_read_lock();
413 	pv = rcu_dereference(port->vlan_info);
414 
415 	if (!pv)
416 		goto out;
417 
418 	if (test_bit(vid, pv->vlan_bitmap))
419 		found = true;
420 
421 out:
422 	rcu_read_unlock();
423 	return found;
424 }
425