GNU Linux-libre 4.19.211-gnu1
[releases.git] / net / switchdev / switchdev.c
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  */
39 void 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 }
47 EXPORT_SYMBOL_GPL(switchdev_trans_item_enqueue);
48
49 static 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  */
67 void *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 }
75 EXPORT_SYMBOL_GPL(switchdev_trans_item_dequeue);
76
77 static void switchdev_trans_init(struct switchdev_trans *trans)
78 {
79         INIT_LIST_HEAD(&trans->item_list);
80 }
81
82 static 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
90 static 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
98 static LIST_HEAD(deferred);
99 static DEFINE_SPINLOCK(deferred_lock);
100
101 typedef void switchdev_deferred_func_t(struct net_device *dev,
102                                        const void *data);
103
104 struct 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
111 static 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);
123 unlock:
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  */
134 void 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 }
146 EXPORT_SYMBOL_GPL(switchdev_deferred_process);
147
148 static void switchdev_deferred_process_work(struct work_struct *work)
149 {
150         rtnl_lock();
151         switchdev_deferred_process();
152         rtnl_unlock();
153 }
154
155 static DECLARE_WORK(deferred_process_work, switchdev_deferred_process_work);
156
157 static 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  */
183 int 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 }
217 EXPORT_SYMBOL_GPL(switchdev_port_attr_get);
218
219 static 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
247 done:
248         if (err == -EOPNOTSUPP && attr->flags & SWITCHDEV_F_SKIP_EOPNOTSUPP)
249                 err = 0;
250
251         return err;
252 }
253
254 static 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
297 static 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
311 static 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  */
331 int 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 }
339 EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
340
341 static 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
356 static 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
382 static 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
426 static 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
440 static 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  */
461 int 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 }
469 EXPORT_SYMBOL_GPL(switchdev_port_obj_add);
470
471 static 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
496 static 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
510 static 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  */
527 int 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 }
535 EXPORT_SYMBOL_GPL(switchdev_port_obj_del);
536
537 static 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  */
545 int register_switchdev_notifier(struct notifier_block *nb)
546 {
547         return atomic_notifier_chain_register(&switchdev_notif_chain, nb);
548 }
549 EXPORT_SYMBOL_GPL(register_switchdev_notifier);
550
551 /**
552  *      unregister_switchdev_notifier - Unregister notifier
553  *      @nb: notifier_block
554  *
555  *      Unregister switch device notifier.
556  */
557 int unregister_switchdev_notifier(struct notifier_block *nb)
558 {
559         return atomic_notifier_chain_unregister(&switchdev_notif_chain, nb);
560 }
561 EXPORT_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  */
571 int 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 }
577 EXPORT_SYMBOL_GPL(call_switchdev_notifiers);
578
579 bool 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 }
597 EXPORT_SYMBOL_GPL(switchdev_port_same_parent_id);