xref: /openbmc/linux/net/bridge/br_vlan.c (revision db181ce0)
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, br->vlan_proto, 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, br->vlan_proto, 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 		struct net_bridge_port *p = v->parent.port;
97 		vlan_vid_del(p->dev, p->br->vlan_proto, vid);
98 	}
99 
100 	clear_bit(vid, v->vlan_bitmap);
101 	v->num_vlans--;
102 	if (bitmap_empty(v->vlan_bitmap, VLAN_N_VID)) {
103 		if (v->port_idx)
104 			RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
105 		else
106 			RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
107 		kfree_rcu(v, rcu);
108 	}
109 	return 0;
110 }
111 
112 static void __vlan_flush(struct net_port_vlans *v)
113 {
114 	smp_wmb();
115 	v->pvid = 0;
116 	bitmap_zero(v->vlan_bitmap, VLAN_N_VID);
117 	if (v->port_idx)
118 		RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
119 	else
120 		RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
121 	kfree_rcu(v, rcu);
122 }
123 
124 struct sk_buff *br_handle_vlan(struct net_bridge *br,
125 			       const struct net_port_vlans *pv,
126 			       struct sk_buff *skb)
127 {
128 	u16 vid;
129 
130 	if (!br->vlan_enabled)
131 		goto out;
132 
133 	/* Vlan filter table must be configured at this point.  The
134 	 * only exception is the bridge is set in promisc mode and the
135 	 * packet is destined for the bridge device.  In this case
136 	 * pass the packet as is.
137 	 */
138 	if (!pv) {
139 		if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) {
140 			goto out;
141 		} else {
142 			kfree_skb(skb);
143 			return NULL;
144 		}
145 	}
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->vlan_tci = 0;
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 	bool tagged;
164 	__be16 proto;
165 
166 	/* If VLAN filtering is disabled on the bridge, all packets are
167 	 * permitted.
168 	 */
169 	if (!br->vlan_enabled)
170 		return true;
171 
172 	/* If there are no vlan in the permitted list, all packets are
173 	 * rejected.
174 	 */
175 	if (!v)
176 		goto drop;
177 
178 	proto = br->vlan_proto;
179 
180 	/* If vlan tx offload is disabled on bridge device and frame was
181 	 * sent from vlan device on the bridge device, it does not have
182 	 * HW accelerated vlan tag.
183 	 */
184 	if (unlikely(!vlan_tx_tag_present(skb) &&
185 		     skb->protocol == proto)) {
186 		skb = vlan_untag(skb);
187 		if (unlikely(!skb))
188 			return false;
189 	}
190 
191 	if (!br_vlan_get_tag(skb, vid)) {
192 		/* Tagged frame */
193 		if (skb->vlan_proto != proto) {
194 			/* Protocol-mismatch, empty out vlan_tci for new tag */
195 			skb_push(skb, ETH_HLEN);
196 			skb = __vlan_put_tag(skb, skb->vlan_proto,
197 					     vlan_tx_tag_get(skb));
198 			if (unlikely(!skb))
199 				return false;
200 
201 			skb_pull(skb, ETH_HLEN);
202 			skb_reset_mac_len(skb);
203 			*vid = 0;
204 			tagged = false;
205 		} else {
206 			tagged = true;
207 		}
208 	} else {
209 		/* Untagged frame */
210 		tagged = false;
211 	}
212 
213 	if (!*vid) {
214 		u16 pvid = br_get_pvid(v);
215 
216 		/* Frame had a tag with VID 0 or did not have a tag.
217 		 * See if pvid is set on this port.  That tells us which
218 		 * vlan untagged or priority-tagged traffic belongs to.
219 		 */
220 		if (pvid == VLAN_N_VID)
221 			goto drop;
222 
223 		/* PVID is set on this port.  Any untagged or priority-tagged
224 		 * ingress frame is considered to belong to this vlan.
225 		 */
226 		*vid = pvid;
227 		if (likely(!tagged))
228 			/* Untagged Frame. */
229 			__vlan_hwaccel_put_tag(skb, proto, pvid);
230 		else
231 			/* Priority-tagged Frame.
232 			 * At this point, We know that skb->vlan_tci had
233 			 * VLAN_TAG_PRESENT bit and its VID field was 0x000.
234 			 * We update only VID field and preserve PCP field.
235 			 */
236 			skb->vlan_tci |= pvid;
237 
238 		return true;
239 	}
240 
241 	/* Frame had a valid vlan tag.  See if vlan is allowed */
242 	if (test_bit(*vid, v->vlan_bitmap))
243 		return true;
244 drop:
245 	kfree_skb(skb);
246 	return false;
247 }
248 
249 /* Called under RCU. */
250 bool br_allowed_egress(struct net_bridge *br,
251 		       const struct net_port_vlans *v,
252 		       const struct sk_buff *skb)
253 {
254 	u16 vid;
255 
256 	if (!br->vlan_enabled)
257 		return true;
258 
259 	if (!v)
260 		return false;
261 
262 	br_vlan_get_tag(skb, &vid);
263 	if (test_bit(vid, v->vlan_bitmap))
264 		return true;
265 
266 	return false;
267 }
268 
269 /* Called under RCU */
270 bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
271 {
272 	struct net_bridge *br = p->br;
273 	struct net_port_vlans *v;
274 
275 	if (!br->vlan_enabled)
276 		return true;
277 
278 	v = rcu_dereference(p->vlan_info);
279 	if (!v)
280 		return false;
281 
282 	if (!br_vlan_get_tag(skb, vid) && skb->vlan_proto != br->vlan_proto)
283 		*vid = 0;
284 
285 	if (!*vid) {
286 		*vid = br_get_pvid(v);
287 		if (*vid == VLAN_N_VID)
288 			return false;
289 
290 		return true;
291 	}
292 
293 	if (test_bit(*vid, v->vlan_bitmap))
294 		return true;
295 
296 	return false;
297 }
298 
299 /* Must be protected by RTNL.
300  * Must be called with vid in range from 1 to 4094 inclusive.
301  */
302 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
303 {
304 	struct net_port_vlans *pv = NULL;
305 	int err;
306 
307 	ASSERT_RTNL();
308 
309 	pv = rtnl_dereference(br->vlan_info);
310 	if (pv)
311 		return __vlan_add(pv, vid, flags);
312 
313 	/* Create port vlan infomration
314 	 */
315 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
316 	if (!pv)
317 		return -ENOMEM;
318 
319 	pv->parent.br = br;
320 	err = __vlan_add(pv, vid, flags);
321 	if (err)
322 		goto out;
323 
324 	rcu_assign_pointer(br->vlan_info, pv);
325 	return 0;
326 out:
327 	kfree(pv);
328 	return err;
329 }
330 
331 /* Must be protected by RTNL.
332  * Must be called with vid in range from 1 to 4094 inclusive.
333  */
334 int br_vlan_delete(struct net_bridge *br, u16 vid)
335 {
336 	struct net_port_vlans *pv;
337 
338 	ASSERT_RTNL();
339 
340 	pv = rtnl_dereference(br->vlan_info);
341 	if (!pv)
342 		return -EINVAL;
343 
344 	br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
345 
346 	__vlan_del(pv, vid);
347 	return 0;
348 }
349 
350 void br_vlan_flush(struct net_bridge *br)
351 {
352 	struct net_port_vlans *pv;
353 
354 	ASSERT_RTNL();
355 	pv = rtnl_dereference(br->vlan_info);
356 	if (!pv)
357 		return;
358 
359 	__vlan_flush(pv);
360 }
361 
362 bool br_vlan_find(struct net_bridge *br, u16 vid)
363 {
364 	struct net_port_vlans *pv;
365 	bool found = false;
366 
367 	rcu_read_lock();
368 	pv = rcu_dereference(br->vlan_info);
369 
370 	if (!pv)
371 		goto out;
372 
373 	if (test_bit(vid, pv->vlan_bitmap))
374 		found = true;
375 
376 out:
377 	rcu_read_unlock();
378 	return found;
379 }
380 
381 /* Must be protected by RTNL. */
382 static void recalculate_group_addr(struct net_bridge *br)
383 {
384 	if (br->group_addr_set)
385 		return;
386 
387 	spin_lock_bh(&br->lock);
388 	if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q)) {
389 		/* Bridge Group Address */
390 		br->group_addr[5] = 0x00;
391 	} else { /* vlan_enabled && ETH_P_8021AD */
392 		/* Provider Bridge Group Address */
393 		br->group_addr[5] = 0x08;
394 	}
395 	spin_unlock_bh(&br->lock);
396 }
397 
398 /* Must be protected by RTNL. */
399 void br_recalculate_fwd_mask(struct net_bridge *br)
400 {
401 	if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q))
402 		br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
403 	else /* vlan_enabled && ETH_P_8021AD */
404 		br->group_fwd_mask_required = BR_GROUPFWD_8021AD &
405 					      ~(1u << br->group_addr[5]);
406 }
407 
408 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
409 {
410 	if (!rtnl_trylock())
411 		return restart_syscall();
412 
413 	if (br->vlan_enabled == val)
414 		goto unlock;
415 
416 	br->vlan_enabled = val;
417 	br_manage_promisc(br);
418 	recalculate_group_addr(br);
419 	br_recalculate_fwd_mask(br);
420 
421 unlock:
422 	rtnl_unlock();
423 	return 0;
424 }
425 
426 int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
427 {
428 	int err = 0;
429 	struct net_bridge_port *p;
430 	struct net_port_vlans *pv;
431 	__be16 proto, oldproto;
432 	u16 vid, errvid;
433 
434 	if (val != ETH_P_8021Q && val != ETH_P_8021AD)
435 		return -EPROTONOSUPPORT;
436 
437 	if (!rtnl_trylock())
438 		return restart_syscall();
439 
440 	proto = htons(val);
441 	if (br->vlan_proto == proto)
442 		goto unlock;
443 
444 	/* Add VLANs for the new proto to the device filter. */
445 	list_for_each_entry(p, &br->port_list, list) {
446 		pv = rtnl_dereference(p->vlan_info);
447 		if (!pv)
448 			continue;
449 
450 		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
451 			err = vlan_vid_add(p->dev, proto, vid);
452 			if (err)
453 				goto err_filt;
454 		}
455 	}
456 
457 	oldproto = br->vlan_proto;
458 	br->vlan_proto = proto;
459 
460 	recalculate_group_addr(br);
461 	br_recalculate_fwd_mask(br);
462 
463 	/* Delete VLANs for the old proto from the device filter. */
464 	list_for_each_entry(p, &br->port_list, list) {
465 		pv = rtnl_dereference(p->vlan_info);
466 		if (!pv)
467 			continue;
468 
469 		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
470 			vlan_vid_del(p->dev, oldproto, vid);
471 	}
472 
473 unlock:
474 	rtnl_unlock();
475 	return err;
476 
477 err_filt:
478 	errvid = vid;
479 	for_each_set_bit(vid, pv->vlan_bitmap, errvid)
480 		vlan_vid_del(p->dev, proto, vid);
481 
482 	list_for_each_entry_continue_reverse(p, &br->port_list, list) {
483 		pv = rtnl_dereference(p->vlan_info);
484 		if (!pv)
485 			continue;
486 
487 		for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
488 			vlan_vid_del(p->dev, proto, vid);
489 	}
490 
491 	goto unlock;
492 }
493 
494 void br_vlan_init(struct net_bridge *br)
495 {
496 	br->vlan_proto = htons(ETH_P_8021Q);
497 }
498 
499 /* Must be protected by RTNL.
500  * Must be called with vid in range from 1 to 4094 inclusive.
501  */
502 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
503 {
504 	struct net_port_vlans *pv = NULL;
505 	int err;
506 
507 	ASSERT_RTNL();
508 
509 	pv = rtnl_dereference(port->vlan_info);
510 	if (pv)
511 		return __vlan_add(pv, vid, flags);
512 
513 	/* Create port vlan infomration
514 	 */
515 	pv = kzalloc(sizeof(*pv), GFP_KERNEL);
516 	if (!pv) {
517 		err = -ENOMEM;
518 		goto clean_up;
519 	}
520 
521 	pv->port_idx = port->port_no;
522 	pv->parent.port = port;
523 	err = __vlan_add(pv, vid, flags);
524 	if (err)
525 		goto clean_up;
526 
527 	rcu_assign_pointer(port->vlan_info, pv);
528 	return 0;
529 
530 clean_up:
531 	kfree(pv);
532 	return err;
533 }
534 
535 /* Must be protected by RTNL.
536  * Must be called with vid in range from 1 to 4094 inclusive.
537  */
538 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
539 {
540 	struct net_port_vlans *pv;
541 
542 	ASSERT_RTNL();
543 
544 	pv = rtnl_dereference(port->vlan_info);
545 	if (!pv)
546 		return -EINVAL;
547 
548 	br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
549 
550 	return __vlan_del(pv, vid);
551 }
552 
553 void nbp_vlan_flush(struct net_bridge_port *port)
554 {
555 	struct net_port_vlans *pv;
556 	u16 vid;
557 
558 	ASSERT_RTNL();
559 
560 	pv = rtnl_dereference(port->vlan_info);
561 	if (!pv)
562 		return;
563 
564 	for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
565 		vlan_vid_del(port->dev, port->br->vlan_proto, vid);
566 
567 	__vlan_flush(pv);
568 }
569 
570 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
571 {
572 	struct net_port_vlans *pv;
573 	bool found = false;
574 
575 	rcu_read_lock();
576 	pv = rcu_dereference(port->vlan_info);
577 
578 	if (!pv)
579 		goto out;
580 
581 	if (test_bit(vid, pv->vlan_bitmap))
582 		found = true;
583 
584 out:
585 	rcu_read_unlock();
586 	return found;
587 }
588