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  1/*
  2 * net/switchdev/switchdev.c - Switch device API
  3 * Copyright (c) 2014-2015 Jiri Pirko <jiri@resnulli.us>
  4 * Copyright (c) 2014-2015 Scott Feldman <sfeldma@gmail.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License, or
  9 * (at your option) any later version.
 10 */
 11
 12#include <linux/kernel.h>
 13#include <linux/types.h>
 14#include <linux/init.h>
 15#include <linux/mutex.h>
 16#include <linux/notifier.h>
 17#include <linux/netdevice.h>
 18#include <linux/etherdevice.h>
 19#include <linux/if_bridge.h>
 20#include <linux/list.h>
 21#include <linux/workqueue.h>
 22#include <linux/if_vlan.h>
 23#include <linux/rtnetlink.h>
 24#include <net/switchdev.h>
 25
 26/**
 27 *	switchdev_trans_item_enqueue - Enqueue data item to transaction queue
 28 *
 29 *	@trans: transaction
 30 *	@data: pointer to data being queued
 31 *	@destructor: data destructor
 32 *	@tritem: transaction item being queued
 33 *
 34 *	Enqeueue data item to transaction queue. tritem is typically placed in
 35 *	cointainter pointed at by data pointer. Destructor is called on
 36 *	transaction abort and after successful commit phase in case
 37 *	the caller did not dequeue the item before.
 38 */
 39void switchdev_trans_item_enqueue(struct switchdev_trans *trans,
 40				  void *data, void (*destructor)(void const *),
 41				  struct switchdev_trans_item *tritem)
 42{
 43	tritem->data = data;
 44	tritem->destructor = destructor;
 45	list_add_tail(&tritem->list, &trans->item_list);
 46}
 47EXPORT_SYMBOL_GPL(switchdev_trans_item_enqueue);
 48
 49static struct switchdev_trans_item *
 50__switchdev_trans_item_dequeue(struct switchdev_trans *trans)
 51{
 52	struct switchdev_trans_item *tritem;
 53
 54	if (list_empty(&trans->item_list))
 55		return NULL;
 56	tritem = list_first_entry(&trans->item_list,
 57				  struct switchdev_trans_item, list);
 58	list_del(&tritem->list);
 59	return tritem;
 60}
 61
 62/**
 63 *	switchdev_trans_item_dequeue - Dequeue data item from transaction queue
 64 *
 65 *	@trans: transaction
 66 */
 67void *switchdev_trans_item_dequeue(struct switchdev_trans *trans)
 68{
 69	struct switchdev_trans_item *tritem;
 70
 71	tritem = __switchdev_trans_item_dequeue(trans);
 72	BUG_ON(!tritem);
 73	return tritem->data;
 74}
 75EXPORT_SYMBOL_GPL(switchdev_trans_item_dequeue);
 76
 77static void switchdev_trans_init(struct switchdev_trans *trans)
 78{
 79	INIT_LIST_HEAD(&trans->item_list);
 80}
 81
 82static void switchdev_trans_items_destroy(struct switchdev_trans *trans)
 83{
 84	struct switchdev_trans_item *tritem;
 85
 86	while ((tritem = __switchdev_trans_item_dequeue(trans)))
 87		tritem->destructor(tritem->data);
 88}
 89
 90static void switchdev_trans_items_warn_destroy(struct net_device *dev,
 91					       struct switchdev_trans *trans)
 92{
 93	WARN(!list_empty(&trans->item_list), "%s: transaction item queue is not empty.\n",
 94	     dev->name);
 95	switchdev_trans_items_destroy(trans);
 96}
 97
 98static LIST_HEAD(deferred);
 99static DEFINE_SPINLOCK(deferred_lock);
100
101typedef void switchdev_deferred_func_t(struct net_device *dev,
102				       const void *data);
103
104struct switchdev_deferred_item {
105	struct list_head list;
106	struct net_device *dev;
107	switchdev_deferred_func_t *func;
108	unsigned long data[0];
109};
110
111static struct switchdev_deferred_item *switchdev_deferred_dequeue(void)
112{
113	struct switchdev_deferred_item *dfitem;
114
115	spin_lock_bh(&deferred_lock);
116	if (list_empty(&deferred)) {
117		dfitem = NULL;
118		goto unlock;
119	}
120	dfitem = list_first_entry(&deferred,
121				  struct switchdev_deferred_item, list);
122	list_del(&dfitem->list);
123unlock:
124	spin_unlock_bh(&deferred_lock);
125	return dfitem;
126}
127
128/**
129 *	switchdev_deferred_process - Process ops in deferred queue
130 *
131 *	Called to flush the ops currently queued in deferred ops queue.
132 *	rtnl_lock must be held.
133 */
134void switchdev_deferred_process(void)
135{
136	struct switchdev_deferred_item *dfitem;
137
138	ASSERT_RTNL();
139
140	while ((dfitem = switchdev_deferred_dequeue())) {
141		dfitem->func(dfitem->dev, dfitem->data);
142		dev_put(dfitem->dev);
143		kfree(dfitem);
144	}
145}
146EXPORT_SYMBOL_GPL(switchdev_deferred_process);
147
148static void switchdev_deferred_process_work(struct work_struct *work)
149{
150	rtnl_lock();
151	switchdev_deferred_process();
152	rtnl_unlock();
153}
154
155static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);
156
157static int switchdev_deferred_enqueue(struct net_device *dev,
158				      const void *data, size_t data_len,
159				      switchdev_deferred_func_t *func)
160{
161	struct switchdev_deferred_item *dfitem;
162
163	dfitem = kmalloc(sizeof(*dfitem) + data_len, GFP_ATOMIC);
164	if (!dfitem)
165		return -ENOMEM;
166	dfitem->dev = dev;
167	dfitem->func = func;
168	memcpy(dfitem->data, data, data_len);
169	dev_hold(dev);
170	spin_lock_bh(&deferred_lock);
171	list_add_tail(&dfitem->list, &deferred);
172	spin_unlock_bh(&deferred_lock);
173	schedule_work(&deferred_process_work);
174	return 0;
175}
176
177/**
178 *	switchdev_port_attr_get - Get port attribute
179 *
180 *	@dev: port device
181 *	@attr: attribute to get
182 */
183int switchdev_port_attr_get(struct net_device *dev, struct switchdev_attr *attr)
184{
185	const struct switchdev_ops *ops = dev->switchdev_ops;
186	struct net_device *lower_dev;
187	struct list_head *iter;
188	struct switchdev_attr first = {
189		.id = SWITCHDEV_ATTR_ID_UNDEFINED
190	};
191	int err = -EOPNOTSUPP;
192
193	if (ops && ops->switchdev_port_attr_get)
194		return ops->switchdev_port_attr_get(dev, attr);
195
196	if (attr->flags & SWITCHDEV_F_NO_RECURSE)
197		return err;
198
199	/* Switch device port(s) may be stacked under
200	 * bond/team/vlan dev, so recurse down to get attr on
201	 * each port.  Return -ENODATA if attr values don't
202	 * compare across ports.
203	 */
204
205	netdev_for_each_lower_dev(dev, lower_dev, iter) {
206		err = switchdev_port_attr_get(lower_dev, attr);
207		if (err)
208			break;
209		if (first.id == SWITCHDEV_ATTR_ID_UNDEFINED)
210			first = *attr;
211		else if (memcmp(&first, attr, sizeof(*attr)))
212			return -ENODATA;
213	}
214
215	return err;
216}
217EXPORT_SYMBOL_GPL(switchdev_port_attr_get);
218
219static int __switchdev_port_attr_set(struct net_device *dev,
220				     const struct switchdev_attr *attr,
221				     struct switchdev_trans *trans)
222{
223	const struct switchdev_ops *ops = dev->switchdev_ops;
224	struct net_device *lower_dev;
225	struct list_head *iter;
226	int err = -EOPNOTSUPP;
227
228	if (ops && ops->switchdev_port_attr_set) {
229		err = ops->switchdev_port_attr_set(dev, attr, trans);
230		goto done;
231	}
232
233	if (attr->flags & SWITCHDEV_F_NO_RECURSE)
234		goto done;
235
236	/* Switch device port(s) may be stacked under
237	 * bond/team/vlan dev, so recurse down to set attr on
238	 * each port.
239	 */
240
241	netdev_for_each_lower_dev(dev, lower_dev, iter) {
242		err = __switchdev_port_attr_set(lower_dev, attr, trans);
243		if (err)
244			break;
245	}
246
247done:
248	if (err == -EOPNOTSUPP && attr->flags & SWITCHDEV_F_SKIP_EOPNOTSUPP)
249		err = 0;
250
251	return err;
252}
253
254static int switchdev_port_attr_set_now(struct net_device *dev,
255				       const struct switchdev_attr *attr)
256{
257	struct switchdev_trans trans;
258	int err;
259
260	switchdev_trans_init(&trans);
261
262	/* Phase I: prepare for attr set. Driver/device should fail
263	 * here if there are going to be issues in the commit phase,
264	 * such as lack of resources or support.  The driver/device
265	 * should reserve resources needed for the commit phase here,
266	 * but should not commit the attr.
267	 */
268
269	trans.ph_prepare = true;
270	err = __switchdev_port_attr_set(dev, attr, &trans);
271	if (err) {
272		/* Prepare phase failed: abort the transaction.  Any
273		 * resources reserved in the prepare phase are
274		 * released.
275		 */
276
277		if (err != -EOPNOTSUPP)
278			switchdev_trans_items_destroy(&trans);
279
280		return err;
281	}
282
283	/* Phase II: commit attr set.  This cannot fail as a fault
284	 * of driver/device.  If it does, it's a bug in the driver/device
285	 * because the driver said everythings was OK in phase I.
286	 */
287
288	trans.ph_prepare = false;
289	err = __switchdev_port_attr_set(dev, attr, &trans);
290	WARN(err, "%s: Commit of attribute (id=%d) failed.\n",
291	     dev->name, attr->id);
292	switchdev_trans_items_warn_destroy(dev, &trans);
293
294	return err;
295}
296
297static void switchdev_port_attr_set_deferred(struct net_device *dev,
298					     const void *data)
299{
300	const struct switchdev_attr *attr = data;
301	int err;
302
303	err = switchdev_port_attr_set_now(dev, attr);
304	if (err && err != -EOPNOTSUPP)
305		netdev_err(dev, "failed (err=%d) to set attribute (id=%d)\n",
306			   err, attr->id);
307	if (attr->complete)
308		attr->complete(dev, err, attr->complete_priv);
309}
310
311static int switchdev_port_attr_set_defer(struct net_device *dev,
312					 const struct switchdev_attr *attr)
313{
314	return switchdev_deferred_enqueue(dev, attr, sizeof(*attr),
315					  switchdev_port_attr_set_deferred);
316}
317
318/**
319 *	switchdev_port_attr_set - Set port attribute
320 *
321 *	@dev: port device
322 *	@attr: attribute to set
323 *
324 *	Use a 2-phase prepare-commit transaction model to ensure
325 *	system is not left in a partially updated state due to
326 *	failure from driver/device.
327 *
328 *	rtnl_lock must be held and must not be in atomic section,
329 *	in case SWITCHDEV_F_DEFER flag is not set.
330 */
331int switchdev_port_attr_set(struct net_device *dev,
332			    const struct switchdev_attr *attr)
333{
334	if (attr->flags & SWITCHDEV_F_DEFER)
335		return switchdev_port_attr_set_defer(dev, attr);
336	ASSERT_RTNL();
337	return switchdev_port_attr_set_now(dev, attr);
338}
339EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
340
341static size_t switchdev_obj_size(const struct switchdev_obj *obj)
342{
343	switch (obj->id) {
344	case SWITCHDEV_OBJ_ID_PORT_VLAN:
345		return sizeof(struct switchdev_obj_port_vlan);
346	case SWITCHDEV_OBJ_ID_PORT_MDB:
347		return sizeof(struct switchdev_obj_port_mdb);
348	case SWITCHDEV_OBJ_ID_HOST_MDB:
349		return sizeof(struct switchdev_obj_port_mdb);
350	default:
351		BUG();
352	}
353	return 0;
354}
355
356static int __switchdev_port_obj_add(struct net_device *dev,
357				    const struct switchdev_obj *obj,
358				    struct switchdev_trans *trans)
359{
360	const struct switchdev_ops *ops = dev->switchdev_ops;
361	struct net_device *lower_dev;
362	struct list_head *iter;
363	int err = -EOPNOTSUPP;
364
365	if (ops && ops->switchdev_port_obj_add)
366		return ops->switchdev_port_obj_add(dev, obj, trans);
367
368	/* Switch device port(s) may be stacked under
369	 * bond/team/vlan dev, so recurse down to add object on
370	 * each port.
371	 */
372
373	netdev_for_each_lower_dev(dev, lower_dev, iter) {
374		err = __switchdev_port_obj_add(lower_dev, obj, trans);
375		if (err)
376			break;
377	}
378
379	return err;
380}
381
382static int switchdev_port_obj_add_now(struct net_device *dev,
383				      const struct switchdev_obj *obj)
384{
385	struct switchdev_trans trans;
386	int err;
387
388	ASSERT_RTNL();
389
390	switchdev_trans_init(&trans);
391
392	/* Phase I: prepare for obj add. Driver/device should fail
393	 * here if there are going to be issues in the commit phase,
394	 * such as lack of resources or support.  The driver/device
395	 * should reserve resources needed for the commit phase here,
396	 * but should not commit the obj.
397	 */
398
399	trans.ph_prepare = true;
400	err = __switchdev_port_obj_add(dev, obj, &trans);
401	if (err) {
402		/* Prepare phase failed: abort the transaction.  Any
403		 * resources reserved in the prepare phase are
404		 * released.
405		 */
406
407		if (err != -EOPNOTSUPP)
408			switchdev_trans_items_destroy(&trans);
409
410		return err;
411	}
412
413	/* Phase II: commit obj add.  This cannot fail as a fault
414	 * of driver/device.  If it does, it's a bug in the driver/device
415	 * because the driver said everythings was OK in phase I.
416	 */
417
418	trans.ph_prepare = false;
419	err = __switchdev_port_obj_add(dev, obj, &trans);
420	WARN(err, "%s: Commit of object (id=%d) failed.\n", dev->name, obj->id);
421	switchdev_trans_items_warn_destroy(dev, &trans);
422
423	return err;
424}
425
426static void switchdev_port_obj_add_deferred(struct net_device *dev,
427					    const void *data)
428{
429	const struct switchdev_obj *obj = data;
430	int err;
431
432	err = switchdev_port_obj_add_now(dev, obj);
433	if (err && err != -EOPNOTSUPP)
434		netdev_err(dev, "failed (err=%d) to add object (id=%d)\n",
435			   err, obj->id);
436	if (obj->complete)
437		obj->complete(dev, err, obj->complete_priv);
438}
439
440static int switchdev_port_obj_add_defer(struct net_device *dev,
441					const struct switchdev_obj *obj)
442{
443	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
444					  switchdev_port_obj_add_deferred);
445}
446
447/**
448 *	switchdev_port_obj_add - Add port object
449 *
450 *	@dev: port device
451 *	@id: object ID
452 *	@obj: object to add
453 *
454 *	Use a 2-phase prepare-commit transaction model to ensure
455 *	system is not left in a partially updated state due to
456 *	failure from driver/device.
457 *
458 *	rtnl_lock must be held and must not be in atomic section,
459 *	in case SWITCHDEV_F_DEFER flag is not set.
460 */
461int switchdev_port_obj_add(struct net_device *dev,
462			   const struct switchdev_obj *obj)
463{
464	if (obj->flags & SWITCHDEV_F_DEFER)
465		return switchdev_port_obj_add_defer(dev, obj);
466	ASSERT_RTNL();
467	return switchdev_port_obj_add_now(dev, obj);
468}
469EXPORT_SYMBOL_GPL(switchdev_port_obj_add);
470
471static int switchdev_port_obj_del_now(struct net_device *dev,
472				      const struct switchdev_obj *obj)
473{
474	const struct switchdev_ops *ops = dev->switchdev_ops;
475	struct net_device *lower_dev;
476	struct list_head *iter;
477	int err = -EOPNOTSUPP;
478
479	if (ops && ops->switchdev_port_obj_del)
480		return ops->switchdev_port_obj_del(dev, obj);
481
482	/* Switch device port(s) may be stacked under
483	 * bond/team/vlan dev, so recurse down to delete object on
484	 * each port.
485	 */
486
487	netdev_for_each_lower_dev(dev, lower_dev, iter) {
488		err = switchdev_port_obj_del_now(lower_dev, obj);
489		if (err)
490			break;
491	}
492
493	return err;
494}
495
496static void switchdev_port_obj_del_deferred(struct net_device *dev,
497					    const void *data)
498{
499	const struct switchdev_obj *obj = data;
500	int err;
501
502	err = switchdev_port_obj_del_now(dev, obj);
503	if (err && err != -EOPNOTSUPP)
504		netdev_err(dev, "failed (err=%d) to del object (id=%d)\n",
505			   err, obj->id);
506	if (obj->complete)
507		obj->complete(dev, err, obj->complete_priv);
508}
509
510static int switchdev_port_obj_del_defer(struct net_device *dev,
511					const struct switchdev_obj *obj)
512{
513	return switchdev_deferred_enqueue(dev, obj, switchdev_obj_size(obj),
514					  switchdev_port_obj_del_deferred);
515}
516
517/**
518 *	switchdev_port_obj_del - Delete port object
519 *
520 *	@dev: port device
521 *	@id: object ID
522 *	@obj: object to delete
523 *
524 *	rtnl_lock must be held and must not be in atomic section,
525 *	in case SWITCHDEV_F_DEFER flag is not set.
526 */
527int switchdev_port_obj_del(struct net_device *dev,
528			   const struct switchdev_obj *obj)
529{
530	if (obj->flags & SWITCHDEV_F_DEFER)
531		return switchdev_port_obj_del_defer(dev, obj);
532	ASSERT_RTNL();
533	return switchdev_port_obj_del_now(dev, obj);
534}
535EXPORT_SYMBOL_GPL(switchdev_port_obj_del);
536
537static ATOMIC_NOTIFIER_HEAD(switchdev_notif_chain);
538
539/**
540 *	register_switchdev_notifier - Register notifier
541 *	@nb: notifier_block
542 *
543 *	Register switch device notifier.
544 */
545int register_switchdev_notifier(struct notifier_block *nb)
546{
547	return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
548}
549EXPORT_SYMBOL_GPL(register_switchdev_notifier);
550
551/**
552 *	unregister_switchdev_notifier - Unregister notifier
553 *	@nb: notifier_block
554 *
555 *	Unregister switch device notifier.
556 */
557int unregister_switchdev_notifier(struct notifier_block *nb)
558{
559	return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
560}
561EXPORT_SYMBOL_GPL(unregister_switchdev_notifier);
562
563/**
564 *	call_switchdev_notifiers - Call notifiers
565 *	@val: value passed unmodified to notifier function
566 *	@dev: port device
567 *	@info: notifier information data
568 *
569 *	Call all network notifier blocks.
570 */
571int call_switchdev_notifiers(unsigned long val, struct net_device *dev,
572			     struct switchdev_notifier_info *info)
573{
574	info->dev = dev;
575	return atomic_notifier_call_chain(&switchdev_notif_chain, val, info);
576}
577EXPORT_SYMBOL_GPL(call_switchdev_notifiers);
578
579bool switchdev_port_same_parent_id(struct net_device *a,
580				   struct net_device *b)
581{
582	struct switchdev_attr a_attr = {
583		.orig_dev = a,
584		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
585	};
586	struct switchdev_attr b_attr = {
587		.orig_dev = b,
588		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
589	};
590
591	if (switchdev_port_attr_get(a, &a_attr) ||
592	    switchdev_port_attr_get(b, &b_attr))
593		return false;
594
595	return netdev_phys_item_id_same(&a_attr.u.ppid, &b_attr.u.ppid);
596}
597EXPORT_SYMBOL_GPL(switchdev_port_same_parent_id);