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47#include <linux/bpf.h>
48#include <net/xdp.h>
49#include <linux/filter.h>
50#include <trace/events/xdp.h>
51
52#define DEV_CREATE_FLAG_MASK \
53 (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
54
55struct xdp_dev_bulk_queue {
56 struct xdp_frame *q[DEV_MAP_BULK_SIZE];
57 struct list_head flush_node;
58 struct net_device *dev;
59 struct net_device *dev_rx;
60 unsigned int count;
61};
62
63struct bpf_dtab_netdev {
64 struct net_device *dev;
65 struct hlist_node index_hlist;
66 struct bpf_dtab *dtab;
67 struct bpf_prog *xdp_prog;
68 struct rcu_head rcu;
69 unsigned int idx;
70 struct bpf_devmap_val val;
71};
72
73struct bpf_dtab {
74 struct bpf_map map;
75 struct bpf_dtab_netdev **netdev_map;
76 struct list_head list;
77
78
79 struct hlist_head *dev_index_head;
80 spinlock_t index_lock;
81 unsigned int items;
82 u32 n_buckets;
83};
84
85static DEFINE_PER_CPU(struct list_head, dev_flush_list);
86static DEFINE_SPINLOCK(dev_map_lock);
87static LIST_HEAD(dev_map_list);
88
89static struct hlist_head *dev_map_create_hash(unsigned int entries,
90 int numa_node)
91{
92 int i;
93 struct hlist_head *hash;
94
95 hash = bpf_map_area_alloc(entries * sizeof(*hash), numa_node);
96 if (hash != NULL)
97 for (i = 0; i < entries; i++)
98 INIT_HLIST_HEAD(&hash[i]);
99
100 return hash;
101}
102
103static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
104 int idx)
105{
106 return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)];
107}
108
109static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
110{
111 u32 valsize = attr->value_size;
112 u64 cost = 0;
113 int err;
114
115
116
117
118
119 if (attr->max_entries == 0 || attr->key_size != 4 ||
120 (valsize != offsetofend(struct bpf_devmap_val, ifindex) &&
121 valsize != offsetofend(struct bpf_devmap_val, bpf_prog.fd)) ||
122 attr->map_flags & ~DEV_CREATE_FLAG_MASK)
123 return -EINVAL;
124
125
126
127
128 attr->map_flags |= BPF_F_RDONLY_PROG;
129
130
131 bpf_map_init_from_attr(&dtab->map, attr);
132
133 if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
134 dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
135
136 if (!dtab->n_buckets)
137 return -EINVAL;
138 cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
139 } else {
140 cost += (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
141 }
142
143
144 err = bpf_map_charge_init(&dtab->map.memory, cost);
145 if (err)
146 return -EINVAL;
147
148 if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
149 dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets,
150 dtab->map.numa_node);
151 if (!dtab->dev_index_head)
152 goto free_charge;
153
154 spin_lock_init(&dtab->index_lock);
155 } else {
156 dtab->netdev_map = bpf_map_area_alloc(dtab->map.max_entries *
157 sizeof(struct bpf_dtab_netdev *),
158 dtab->map.numa_node);
159 if (!dtab->netdev_map)
160 goto free_charge;
161 }
162
163 return 0;
164
165free_charge:
166 bpf_map_charge_finish(&dtab->map.memory);
167 return -ENOMEM;
168}
169
170static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
171{
172 struct bpf_dtab *dtab;
173 int err;
174
175 if (!capable(CAP_NET_ADMIN))
176 return ERR_PTR(-EPERM);
177
178 dtab = kzalloc(sizeof(*dtab), GFP_USER);
179 if (!dtab)
180 return ERR_PTR(-ENOMEM);
181
182 err = dev_map_init_map(dtab, attr);
183 if (err) {
184 kfree(dtab);
185 return ERR_PTR(err);
186 }
187
188 spin_lock(&dev_map_lock);
189 list_add_tail_rcu(&dtab->list, &dev_map_list);
190 spin_unlock(&dev_map_lock);
191
192 return &dtab->map;
193}
194
195static void dev_map_free(struct bpf_map *map)
196{
197 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
198 int i;
199
200
201
202
203
204
205
206
207
208
209
210 spin_lock(&dev_map_lock);
211 list_del_rcu(&dtab->list);
212 spin_unlock(&dev_map_lock);
213
214 bpf_clear_redirect_map(map);
215 synchronize_rcu();
216
217
218 rcu_barrier();
219
220 if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
221 for (i = 0; i < dtab->n_buckets; i++) {
222 struct bpf_dtab_netdev *dev;
223 struct hlist_head *head;
224 struct hlist_node *next;
225
226 head = dev_map_index_hash(dtab, i);
227
228 hlist_for_each_entry_safe(dev, next, head, index_hlist) {
229 hlist_del_rcu(&dev->index_hlist);
230 if (dev->xdp_prog)
231 bpf_prog_put(dev->xdp_prog);
232 dev_put(dev->dev);
233 kfree(dev);
234 }
235 }
236
237 bpf_map_area_free(dtab->dev_index_head);
238 } else {
239 for (i = 0; i < dtab->map.max_entries; i++) {
240 struct bpf_dtab_netdev *dev;
241
242 dev = dtab->netdev_map[i];
243 if (!dev)
244 continue;
245
246 if (dev->xdp_prog)
247 bpf_prog_put(dev->xdp_prog);
248 dev_put(dev->dev);
249 kfree(dev);
250 }
251
252 bpf_map_area_free(dtab->netdev_map);
253 }
254
255 kfree(dtab);
256}
257
258static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
259{
260 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
261 u32 index = key ? *(u32 *)key : U32_MAX;
262 u32 *next = next_key;
263
264 if (index >= dtab->map.max_entries) {
265 *next = 0;
266 return 0;
267 }
268
269 if (index == dtab->map.max_entries - 1)
270 return -ENOENT;
271 *next = index + 1;
272 return 0;
273}
274
275struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
276{
277 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
278 struct hlist_head *head = dev_map_index_hash(dtab, key);
279 struct bpf_dtab_netdev *dev;
280
281 hlist_for_each_entry_rcu(dev, head, index_hlist,
282 lockdep_is_held(&dtab->index_lock))
283 if (dev->idx == key)
284 return dev;
285
286 return NULL;
287}
288
289static int dev_map_hash_get_next_key(struct bpf_map *map, void *key,
290 void *next_key)
291{
292 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
293 u32 idx, *next = next_key;
294 struct bpf_dtab_netdev *dev, *next_dev;
295 struct hlist_head *head;
296 int i = 0;
297
298 if (!key)
299 goto find_first;
300
301 idx = *(u32 *)key;
302
303 dev = __dev_map_hash_lookup_elem(map, idx);
304 if (!dev)
305 goto find_first;
306
307 next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&dev->index_hlist)),
308 struct bpf_dtab_netdev, index_hlist);
309
310 if (next_dev) {
311 *next = next_dev->idx;
312 return 0;
313 }
314
315 i = idx & (dtab->n_buckets - 1);
316 i++;
317
318 find_first:
319 for (; i < dtab->n_buckets; i++) {
320 head = dev_map_index_hash(dtab, i);
321
322 next_dev = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
323 struct bpf_dtab_netdev,
324 index_hlist);
325 if (next_dev) {
326 *next = next_dev->idx;
327 return 0;
328 }
329 }
330
331 return -ENOENT;
332}
333
334bool dev_map_can_have_prog(struct bpf_map *map)
335{
336 if ((map->map_type == BPF_MAP_TYPE_DEVMAP ||
337 map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) &&
338 map->value_size != offsetofend(struct bpf_devmap_val, ifindex))
339 return true;
340
341 return false;
342}
343
344static int bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags)
345{
346 struct net_device *dev = bq->dev;
347 int sent = 0, drops = 0, err = 0;
348 int i;
349
350 if (unlikely(!bq->count))
351 return 0;
352
353 for (i = 0; i < bq->count; i++) {
354 struct xdp_frame *xdpf = bq->q[i];
355
356 prefetch(xdpf);
357 }
358
359 sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, flags);
360 if (sent < 0) {
361 err = sent;
362 sent = 0;
363 goto error;
364 }
365 drops = bq->count - sent;
366out:
367 bq->count = 0;
368
369 trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, drops, err);
370 bq->dev_rx = NULL;
371 __list_del_clearprev(&bq->flush_node);
372 return 0;
373error:
374
375
376
377 for (i = 0; i < bq->count; i++) {
378 struct xdp_frame *xdpf = bq->q[i];
379
380 xdp_return_frame_rx_napi(xdpf);
381 drops++;
382 }
383 goto out;
384}
385
386
387
388
389
390
391
392
393
394
395
396void __dev_flush(void)
397{
398 struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
399 struct xdp_dev_bulk_queue *bq, *tmp;
400
401 list_for_each_entry_safe(bq, tmp, flush_list, flush_node)
402 bq_xmit_all(bq, XDP_XMIT_FLUSH);
403}
404
405
406
407
408
409struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
410{
411 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
412 struct bpf_dtab_netdev *obj;
413
414 if (key >= map->max_entries)
415 return NULL;
416
417 obj = READ_ONCE(dtab->netdev_map[key]);
418 return obj;
419}
420
421
422
423
424static int bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf,
425 struct net_device *dev_rx)
426{
427 struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
428 struct xdp_dev_bulk_queue *bq = this_cpu_ptr(dev->xdp_bulkq);
429
430 if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
431 bq_xmit_all(bq, 0);
432
433
434
435
436
437 if (!bq->dev_rx)
438 bq->dev_rx = dev_rx;
439
440 bq->q[bq->count++] = xdpf;
441
442 if (!bq->flush_node.prev)
443 list_add(&bq->flush_node, flush_list);
444
445 return 0;
446}
447
448static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
449 struct net_device *dev_rx)
450{
451 struct xdp_frame *xdpf;
452 int err;
453
454 if (!dev->netdev_ops->ndo_xdp_xmit)
455 return -EOPNOTSUPP;
456
457 err = xdp_ok_fwd_dev(dev, xdp->data_end - xdp->data);
458 if (unlikely(err))
459 return err;
460
461 xdpf = xdp_convert_buff_to_frame(xdp);
462 if (unlikely(!xdpf))
463 return -EOVERFLOW;
464
465 return bq_enqueue(dev, xdpf, dev_rx);
466}
467
468static struct xdp_buff *dev_map_run_prog(struct net_device *dev,
469 struct xdp_buff *xdp,
470 struct bpf_prog *xdp_prog)
471{
472 struct xdp_txq_info txq = { .dev = dev };
473 u32 act;
474
475 xdp_set_data_meta_invalid(xdp);
476 xdp->txq = &txq;
477
478 act = bpf_prog_run_xdp(xdp_prog, xdp);
479 switch (act) {
480 case XDP_PASS:
481 return xdp;
482 case XDP_DROP:
483 break;
484 default:
485 bpf_warn_invalid_xdp_action(act);
486 fallthrough;
487 case XDP_ABORTED:
488 trace_xdp_exception(dev, xdp_prog, act);
489 break;
490 }
491
492 xdp_return_buff(xdp);
493 return NULL;
494}
495
496int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
497 struct net_device *dev_rx)
498{
499 return __xdp_enqueue(dev, xdp, dev_rx);
500}
501
502int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
503 struct net_device *dev_rx)
504{
505 struct net_device *dev = dst->dev;
506
507 if (dst->xdp_prog) {
508 xdp = dev_map_run_prog(dev, xdp, dst->xdp_prog);
509 if (!xdp)
510 return 0;
511 }
512 return __xdp_enqueue(dev, xdp, dev_rx);
513}
514
515int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
516 struct bpf_prog *xdp_prog)
517{
518 int err;
519
520 err = xdp_ok_fwd_dev(dst->dev, skb->len);
521 if (unlikely(err))
522 return err;
523 skb->dev = dst->dev;
524 generic_xdp_tx(skb, xdp_prog);
525
526 return 0;
527}
528
529static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
530{
531 struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key);
532
533 return obj ? &obj->val : NULL;
534}
535
536static void *dev_map_hash_lookup_elem(struct bpf_map *map, void *key)
537{
538 struct bpf_dtab_netdev *obj = __dev_map_hash_lookup_elem(map,
539 *(u32 *)key);
540 return obj ? &obj->val : NULL;
541}
542
543static void __dev_map_entry_free(struct rcu_head *rcu)
544{
545 struct bpf_dtab_netdev *dev;
546
547 dev = container_of(rcu, struct bpf_dtab_netdev, rcu);
548 if (dev->xdp_prog)
549 bpf_prog_put(dev->xdp_prog);
550 dev_put(dev->dev);
551 kfree(dev);
552}
553
554static int dev_map_delete_elem(struct bpf_map *map, void *key)
555{
556 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
557 struct bpf_dtab_netdev *old_dev;
558 int k = *(u32 *)key;
559
560 if (k >= map->max_entries)
561 return -EINVAL;
562
563
564
565
566
567
568
569
570 old_dev = xchg(&dtab->netdev_map[k], NULL);
571 if (old_dev)
572 call_rcu(&old_dev->rcu, __dev_map_entry_free);
573 return 0;
574}
575
576static int dev_map_hash_delete_elem(struct bpf_map *map, void *key)
577{
578 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
579 struct bpf_dtab_netdev *old_dev;
580 int k = *(u32 *)key;
581 unsigned long flags;
582 int ret = -ENOENT;
583
584 spin_lock_irqsave(&dtab->index_lock, flags);
585
586 old_dev = __dev_map_hash_lookup_elem(map, k);
587 if (old_dev) {
588 dtab->items--;
589 hlist_del_init_rcu(&old_dev->index_hlist);
590 call_rcu(&old_dev->rcu, __dev_map_entry_free);
591 ret = 0;
592 }
593 spin_unlock_irqrestore(&dtab->index_lock, flags);
594
595 return ret;
596}
597
598static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
599 struct bpf_dtab *dtab,
600 struct bpf_devmap_val *val,
601 unsigned int idx)
602{
603 struct bpf_prog *prog = NULL;
604 struct bpf_dtab_netdev *dev;
605
606 dev = kmalloc_node(sizeof(*dev), GFP_ATOMIC | __GFP_NOWARN,
607 dtab->map.numa_node);
608 if (!dev)
609 return ERR_PTR(-ENOMEM);
610
611 dev->dev = dev_get_by_index(net, val->ifindex);
612 if (!dev->dev)
613 goto err_out;
614
615 if (val->bpf_prog.fd > 0) {
616 prog = bpf_prog_get_type_dev(val->bpf_prog.fd,
617 BPF_PROG_TYPE_XDP, false);
618 if (IS_ERR(prog))
619 goto err_put_dev;
620 if (prog->expected_attach_type != BPF_XDP_DEVMAP)
621 goto err_put_prog;
622 }
623
624 dev->idx = idx;
625 dev->dtab = dtab;
626 if (prog) {
627 dev->xdp_prog = prog;
628 dev->val.bpf_prog.id = prog->aux->id;
629 } else {
630 dev->xdp_prog = NULL;
631 dev->val.bpf_prog.id = 0;
632 }
633 dev->val.ifindex = val->ifindex;
634
635 return dev;
636err_put_prog:
637 bpf_prog_put(prog);
638err_put_dev:
639 dev_put(dev->dev);
640err_out:
641 kfree(dev);
642 return ERR_PTR(-EINVAL);
643}
644
645static int __dev_map_update_elem(struct net *net, struct bpf_map *map,
646 void *key, void *value, u64 map_flags)
647{
648 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
649 struct bpf_dtab_netdev *dev, *old_dev;
650 struct bpf_devmap_val val = {};
651 u32 i = *(u32 *)key;
652
653 if (unlikely(map_flags > BPF_EXIST))
654 return -EINVAL;
655 if (unlikely(i >= dtab->map.max_entries))
656 return -E2BIG;
657 if (unlikely(map_flags == BPF_NOEXIST))
658 return -EEXIST;
659
660
661 memcpy(&val, value, map->value_size);
662
663 if (!val.ifindex) {
664 dev = NULL;
665
666 if (val.bpf_prog.fd > 0)
667 return -EINVAL;
668 } else {
669 dev = __dev_map_alloc_node(net, dtab, &val, i);
670 if (IS_ERR(dev))
671 return PTR_ERR(dev);
672 }
673
674
675
676
677
678 old_dev = xchg(&dtab->netdev_map[i], dev);
679 if (old_dev)
680 call_rcu(&old_dev->rcu, __dev_map_entry_free);
681
682 return 0;
683}
684
685static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
686 u64 map_flags)
687{
688 return __dev_map_update_elem(current->nsproxy->net_ns,
689 map, key, value, map_flags);
690}
691
692static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map,
693 void *key, void *value, u64 map_flags)
694{
695 struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
696 struct bpf_dtab_netdev *dev, *old_dev;
697 struct bpf_devmap_val val = {};
698 u32 idx = *(u32 *)key;
699 unsigned long flags;
700 int err = -EEXIST;
701
702
703 memcpy(&val, value, map->value_size);
704
705 if (unlikely(map_flags > BPF_EXIST || !val.ifindex))
706 return -EINVAL;
707
708 spin_lock_irqsave(&dtab->index_lock, flags);
709
710 old_dev = __dev_map_hash_lookup_elem(map, idx);
711 if (old_dev && (map_flags & BPF_NOEXIST))
712 goto out_err;
713
714 dev = __dev_map_alloc_node(net, dtab, &val, idx);
715 if (IS_ERR(dev)) {
716 err = PTR_ERR(dev);
717 goto out_err;
718 }
719
720 if (old_dev) {
721 hlist_del_rcu(&old_dev->index_hlist);
722 } else {
723 if (dtab->items >= dtab->map.max_entries) {
724 spin_unlock_irqrestore(&dtab->index_lock, flags);
725 call_rcu(&dev->rcu, __dev_map_entry_free);
726 return -E2BIG;
727 }
728 dtab->items++;
729 }
730
731 hlist_add_head_rcu(&dev->index_hlist,
732 dev_map_index_hash(dtab, idx));
733 spin_unlock_irqrestore(&dtab->index_lock, flags);
734
735 if (old_dev)
736 call_rcu(&old_dev->rcu, __dev_map_entry_free);
737
738 return 0;
739
740out_err:
741 spin_unlock_irqrestore(&dtab->index_lock, flags);
742 return err;
743}
744
745static int dev_map_hash_update_elem(struct bpf_map *map, void *key, void *value,
746 u64 map_flags)
747{
748 return __dev_map_hash_update_elem(current->nsproxy->net_ns,
749 map, key, value, map_flags);
750}
751
752const struct bpf_map_ops dev_map_ops = {
753 .map_alloc = dev_map_alloc,
754 .map_free = dev_map_free,
755 .map_get_next_key = dev_map_get_next_key,
756 .map_lookup_elem = dev_map_lookup_elem,
757 .map_update_elem = dev_map_update_elem,
758 .map_delete_elem = dev_map_delete_elem,
759 .map_check_btf = map_check_no_btf,
760};
761
762const struct bpf_map_ops dev_map_hash_ops = {
763 .map_alloc = dev_map_alloc,
764 .map_free = dev_map_free,
765 .map_get_next_key = dev_map_hash_get_next_key,
766 .map_lookup_elem = dev_map_hash_lookup_elem,
767 .map_update_elem = dev_map_hash_update_elem,
768 .map_delete_elem = dev_map_hash_delete_elem,
769 .map_check_btf = map_check_no_btf,
770};
771
772static void dev_map_hash_remove_netdev(struct bpf_dtab *dtab,
773 struct net_device *netdev)
774{
775 unsigned long flags;
776 u32 i;
777
778 spin_lock_irqsave(&dtab->index_lock, flags);
779 for (i = 0; i < dtab->n_buckets; i++) {
780 struct bpf_dtab_netdev *dev;
781 struct hlist_head *head;
782 struct hlist_node *next;
783
784 head = dev_map_index_hash(dtab, i);
785
786 hlist_for_each_entry_safe(dev, next, head, index_hlist) {
787 if (netdev != dev->dev)
788 continue;
789
790 dtab->items--;
791 hlist_del_rcu(&dev->index_hlist);
792 call_rcu(&dev->rcu, __dev_map_entry_free);
793 }
794 }
795 spin_unlock_irqrestore(&dtab->index_lock, flags);
796}
797
798static int dev_map_notification(struct notifier_block *notifier,
799 ulong event, void *ptr)
800{
801 struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
802 struct bpf_dtab *dtab;
803 int i, cpu;
804
805 switch (event) {
806 case NETDEV_REGISTER:
807 if (!netdev->netdev_ops->ndo_xdp_xmit || netdev->xdp_bulkq)
808 break;
809
810
811 netdev->xdp_bulkq =
812 __alloc_percpu_gfp(sizeof(struct xdp_dev_bulk_queue),
813 sizeof(void *), GFP_ATOMIC);
814 if (!netdev->xdp_bulkq)
815 return NOTIFY_BAD;
816
817 for_each_possible_cpu(cpu)
818 per_cpu_ptr(netdev->xdp_bulkq, cpu)->dev = netdev;
819 break;
820 case NETDEV_UNREGISTER:
821
822
823
824
825
826 rcu_read_lock();
827 list_for_each_entry_rcu(dtab, &dev_map_list, list) {
828 if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
829 dev_map_hash_remove_netdev(dtab, netdev);
830 continue;
831 }
832
833 for (i = 0; i < dtab->map.max_entries; i++) {
834 struct bpf_dtab_netdev *dev, *odev;
835
836 dev = READ_ONCE(dtab->netdev_map[i]);
837 if (!dev || netdev != dev->dev)
838 continue;
839 odev = cmpxchg(&dtab->netdev_map[i], dev, NULL);
840 if (dev == odev)
841 call_rcu(&dev->rcu,
842 __dev_map_entry_free);
843 }
844 }
845 rcu_read_unlock();
846 break;
847 default:
848 break;
849 }
850 return NOTIFY_OK;
851}
852
853static struct notifier_block dev_map_notifier = {
854 .notifier_call = dev_map_notification,
855};
856
857static int __init dev_map_init(void)
858{
859 int cpu;
860
861
862 BUILD_BUG_ON(offsetof(struct bpf_dtab_netdev, dev) !=
863 offsetof(struct _bpf_dtab_netdev, dev));
864 register_netdevice_notifier(&dev_map_notifier);
865
866 for_each_possible_cpu(cpu)
867 INIT_LIST_HEAD(&per_cpu(dev_flush_list, cpu));
868 return 0;
869}
870
871subsys_initcall(dev_map_init);
872