xref: /openbmc/linux/net/bridge/br_vlan.c (revision 37be287c)
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 tagged.
150 	 */
151 	br_vlan_get_tag(skb, &vid);
152 	if (test_bit(vid, pv->untagged_bitmap))
153 		skb = br_vlan_untag(skb);
154 
155 out:
156 	return skb;
157 }
158 
159 /* Called under RCU */
160 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
161 			struct sk_buff *skb, u16 *vid)
162 {
163 	int err;
164 
165 	/* If VLAN filtering is disabled on the bridge, all packets are
166 	 * permitted.
167 	 */
168 	if (!br->vlan_enabled)
169 		return true;
170 
171 	/* If there are no vlan in the permitted list, all packets are
172 	 * rejected.
173 	 */
174 	if (!v)
175 		return false;
176 
177 	err = br_vlan_get_tag(skb, vid);
178 	if (!*vid) {
179 		u16 pvid = br_get_pvid(v);
180 
181 		/* Frame had a tag with VID 0 or did not have a tag.
182 		 * See if pvid is set on this port.  That tells us which
183 		 * vlan untagged or priority-tagged traffic belongs to.
184 		 */
185 		if (pvid == VLAN_N_VID)
186 			return false;
187 
188 		/* PVID is set on this port.  Any untagged or priority-tagged
189 		 * ingress frame is considered to belong to this vlan.
190 		 */
191 		*vid = pvid;
192 		if (likely(err))
193 			/* Untagged Frame. */
194 			__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
195 		else
196 			/* Priority-tagged Frame.
197 			 * At this point, We know that skb->vlan_tci had
198 			 * VLAN_TAG_PRESENT bit and its VID field was 0x000.
199 			 * We update only VID field and preserve PCP field.
200 			 */
201 			skb->vlan_tci |= pvid;
202 
203 		return true;
204 	}
205 
206 	/* Frame had a valid vlan tag.  See if vlan is allowed */
207 	if (test_bit(*vid, v->vlan_bitmap))
208 		return true;
209 
210 	return false;
211 }
212 
213 /* Called under RCU. */
214 bool br_allowed_egress(struct net_bridge *br,
215 		       const struct net_port_vlans *v,
216 		       const struct sk_buff *skb)
217 {
218 	u16 vid;
219 
220 	if (!br->vlan_enabled)
221 		return true;
222 
223 	if (!v)
224 		return false;
225 
226 	br_vlan_get_tag(skb, &vid);
227 	if (test_bit(vid, v->vlan_bitmap))
228 		return true;
229 
230 	return false;
231 }
232 
233 /* Must be protected by RTNL.
234  * Must be called with vid in range from 1 to 4094 inclusive.
235  */
236 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
237 {
238 	struct net_port_vlans *pv = NULL;
239 	int err;
240 
241 	ASSERT_RTNL();
242 
243 	pv = rtnl_dereference(br->vlan_info);
244 	if (pv)
245 		return __vlan_add(pv, vid, flags);
246 
247 	/* Create port vlan infomration
248 	 */
249 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
250 	if (!pv)
251 		return -ENOMEM;
252 
253 	pv->parent.br = br;
254 	err = __vlan_add(pv, vid, flags);
255 	if (err)
256 		goto out;
257 
258 	rcu_assign_pointer(br->vlan_info, pv);
259 	return 0;
260 out:
261 	kfree(pv);
262 	return err;
263 }
264 
265 /* Must be protected by RTNL.
266  * Must be called with vid in range from 1 to 4094 inclusive.
267  */
268 int br_vlan_delete(struct net_bridge *br, u16 vid)
269 {
270 	struct net_port_vlans *pv;
271 
272 	ASSERT_RTNL();
273 
274 	pv = rtnl_dereference(br->vlan_info);
275 	if (!pv)
276 		return -EINVAL;
277 
278 	spin_lock_bh(&br->hash_lock);
279 	fdb_delete_by_addr(br, br->dev->dev_addr, vid);
280 	spin_unlock_bh(&br->hash_lock);
281 
282 	__vlan_del(pv, vid);
283 	return 0;
284 }
285 
286 void br_vlan_flush(struct net_bridge *br)
287 {
288 	struct net_port_vlans *pv;
289 
290 	ASSERT_RTNL();
291 	pv = rtnl_dereference(br->vlan_info);
292 	if (!pv)
293 		return;
294 
295 	__vlan_flush(pv);
296 }
297 
298 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
299 {
300 	if (!rtnl_trylock())
301 		return restart_syscall();
302 
303 	if (br->vlan_enabled == val)
304 		goto unlock;
305 
306 	br->vlan_enabled = val;
307 
308 unlock:
309 	rtnl_unlock();
310 	return 0;
311 }
312 
313 /* Must be protected by RTNL.
314  * Must be called with vid in range from 1 to 4094 inclusive.
315  */
316 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
317 {
318 	struct net_port_vlans *pv = NULL;
319 	int err;
320 
321 	ASSERT_RTNL();
322 
323 	pv = rtnl_dereference(port->vlan_info);
324 	if (pv)
325 		return __vlan_add(pv, vid, flags);
326 
327 	/* Create port vlan infomration
328 	 */
329 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
330 	if (!pv) {
331 		err = -ENOMEM;
332 		goto clean_up;
333 	}
334 
335 	pv->port_idx = port->port_no;
336 	pv->parent.port = port;
337 	err = __vlan_add(pv, vid, flags);
338 	if (err)
339 		goto clean_up;
340 
341 	rcu_assign_pointer(port->vlan_info, pv);
342 	return 0;
343 
344 clean_up:
345 	kfree(pv);
346 	return err;
347 }
348 
349 /* Must be protected by RTNL.
350  * Must be called with vid in range from 1 to 4094 inclusive.
351  */
352 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
353 {
354 	struct net_port_vlans *pv;
355 
356 	ASSERT_RTNL();
357 
358 	pv = rtnl_dereference(port->vlan_info);
359 	if (!pv)
360 		return -EINVAL;
361 
362 	spin_lock_bh(&port->br->hash_lock);
363 	fdb_delete_by_addr(port->br, port->dev->dev_addr, vid);
364 	spin_unlock_bh(&port->br->hash_lock);
365 
366 	return __vlan_del(pv, vid);
367 }
368 
369 void nbp_vlan_flush(struct net_bridge_port *port)
370 {
371 	struct net_port_vlans *pv;
372 	u16 vid;
373 
374 	ASSERT_RTNL();
375 
376 	pv = rtnl_dereference(port->vlan_info);
377 	if (!pv)
378 		return;
379 
380 	for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
381 		vlan_vid_del(port->dev, htons(ETH_P_8021Q), vid);
382 
383 	__vlan_flush(pv);
384 }
385 
386 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
387 {
388 	struct net_port_vlans *pv;
389 	bool found = false;
390 
391 	rcu_read_lock();
392 	pv = rcu_dereference(port->vlan_info);
393 
394 	if (!pv)
395 		goto out;
396 
397 	if (test_bit(vid, pv->vlan_bitmap))
398 		found = true;
399 
400 out:
401 	rcu_read_unlock();
402 	return found;
403 }
404