projects/linux·blob v7.0 · refs

868 lines · 19.8 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2017-2018 Netronome Systems, Inc.
4 */
5
6#include <linux/bpf.h>
7#include <linux/bpf_verifier.h>
8#include <linux/bug.h>
9#include <linux/kdev_t.h>
10#include <linux/list.h>
11#include <linux/lockdep.h>
12#include <linux/netdevice.h>
13#include <linux/printk.h>
14#include <linux/proc_ns.h>
15#include <linux/rhashtable.h>
16#include <linux/rtnetlink.h>
17#include <linux/rwsem.h>
18#include <net/netdev_lock.h>
19#include <net/xdp.h>
20
21/* Protects offdevs, members of bpf_offload_netdev and offload members
22 * of all progs.
23 * RTNL lock cannot be taken when holding this lock.
24 */
25static DECLARE_RWSEM(bpf_devs_lock);
26
27struct bpf_offload_dev {
28 const struct bpf_prog_offload_ops *ops;
29 struct list_head netdevs;
30 void *priv;
31};
32
33struct bpf_offload_netdev {
34 struct rhash_head l;
35 struct net_device *netdev;
36 struct bpf_offload_dev *offdev; /* NULL when bound-only */
37 struct list_head progs;
38 struct list_head maps;
39 struct list_head offdev_netdevs;
40};
41
42static const struct rhashtable_params offdevs_params = {
43 .nelem_hint = 4,
44 .key_len = sizeof(struct net_device *),
45 .key_offset = offsetof(struct bpf_offload_netdev, netdev),
46 .head_offset = offsetof(struct bpf_offload_netdev, l),
47 .automatic_shrinking = true,
48};
49
50static struct rhashtable offdevs;
51
52static int bpf_dev_offload_check(struct net_device *netdev)
53{
54 if (!netdev)
55 return -EINVAL;
56 if (!netdev->netdev_ops->ndo_bpf)
57 return -EOPNOTSUPP;
58 return 0;
59}
60
61static struct bpf_offload_netdev *
62bpf_offload_find_netdev(struct net_device *netdev)
63{
64 lockdep_assert_held(&bpf_devs_lock);
65
66 return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
67}
68
69static int __bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
70 struct net_device *netdev)
71{
72 struct bpf_offload_netdev *ondev;
73 int err;
74
75 ondev = kzalloc_obj(*ondev);
76 if (!ondev)
77 return -ENOMEM;
78
79 ondev->netdev = netdev;
80 ondev->offdev = offdev;
81 INIT_LIST_HEAD(&ondev->progs);
82 INIT_LIST_HEAD(&ondev->maps);
83
84 err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params);
85 if (err) {
86 netdev_warn(netdev, "failed to register for BPF offload\n");
87 goto err_free;
88 }
89
90 if (offdev)
91 list_add(&ondev->offdev_netdevs, &offdev->netdevs);
92 return 0;
93
94err_free:
95 kfree(ondev);
96 return err;
97}
98
99static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
100{
101 struct bpf_prog_offload *offload = prog->aux->offload;
102
103 if (offload->dev_state)
104 offload->offdev->ops->destroy(prog);
105
106 list_del_init(&offload->offloads);
107 kfree(offload);
108 prog->aux->offload = NULL;
109}
110
111static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap,
112 enum bpf_netdev_command cmd)
113{
114 struct netdev_bpf data = {};
115 struct net_device *netdev;
116
117 ASSERT_RTNL();
118
119 data.command = cmd;
120 data.offmap = offmap;
121 /* Caller must make sure netdev is valid */
122 netdev = offmap->netdev;
123
124 return netdev->netdev_ops->ndo_bpf(netdev, &data);
125}
126
127static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap)
128{
129 WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE));
130 /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */
131 bpf_map_free_id(&offmap->map);
132 list_del_init(&offmap->offloads);
133 offmap->netdev = NULL;
134}
135
136static void __bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
137 struct net_device *netdev)
138{
139 struct bpf_offload_netdev *ondev, *altdev = NULL;
140 struct bpf_offloaded_map *offmap, *mtmp;
141 struct bpf_prog_offload *offload, *ptmp;
142
143 ASSERT_RTNL();
144
145 ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params);
146 if (WARN_ON(!ondev))
147 return;
148
149 WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params));
150
151 /* Try to move the objects to another netdev of the device */
152 if (offdev) {
153 list_del(&ondev->offdev_netdevs);
154 altdev = list_first_entry_or_null(&offdev->netdevs,
155 struct bpf_offload_netdev,
156 offdev_netdevs);
157 }
158
159 if (altdev) {
160 list_for_each_entry(offload, &ondev->progs, offloads)
161 offload->netdev = altdev->netdev;
162 list_splice_init(&ondev->progs, &altdev->progs);
163
164 list_for_each_entry(offmap, &ondev->maps, offloads)
165 offmap->netdev = altdev->netdev;
166 list_splice_init(&ondev->maps, &altdev->maps);
167 } else {
168 list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads)
169 __bpf_prog_offload_destroy(offload->prog);
170 list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads)
171 __bpf_map_offload_destroy(offmap);
172 }
173
174 WARN_ON(!list_empty(&ondev->progs));
175 WARN_ON(!list_empty(&ondev->maps));
176 kfree(ondev);
177}
178
179static int __bpf_prog_dev_bound_init(struct bpf_prog *prog, struct net_device *netdev)
180{
181 struct bpf_offload_netdev *ondev;
182 struct bpf_prog_offload *offload;
183 int err;
184
185 offload = kzalloc_obj(*offload, GFP_USER);
186 if (!offload)
187 return -ENOMEM;
188
189 offload->prog = prog;
190 offload->netdev = netdev;
191
192 ondev = bpf_offload_find_netdev(offload->netdev);
193 /* When program is offloaded require presence of "true"
194 * bpf_offload_netdev, avoid the one created for !ondev case below.
195 */
196 if (bpf_prog_is_offloaded(prog->aux) && (!ondev || !ondev->offdev)) {
197 err = -EINVAL;
198 goto err_free;
199 }
200 if (!ondev) {
201 /* When only binding to the device, explicitly
202 * create an entry in the hashtable.
203 */
204 err = __bpf_offload_dev_netdev_register(NULL, offload->netdev);
205 if (err)
206 goto err_free;
207 ondev = bpf_offload_find_netdev(offload->netdev);
208 }
209 offload->offdev = ondev->offdev;
210 prog->aux->offload = offload;
211 list_add_tail(&offload->offloads, &ondev->progs);
212
213 return 0;
214err_free:
215 kfree(offload);
216 return err;
217}
218
219int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr)
220{
221 struct net_device *netdev;
222 int err;
223
224 if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
225 attr->prog_type != BPF_PROG_TYPE_XDP)
226 return -EINVAL;
227
228 if (attr->prog_flags & ~(BPF_F_XDP_DEV_BOUND_ONLY | BPF_F_XDP_HAS_FRAGS))
229 return -EINVAL;
230
231 /* Frags are allowed only if program is dev-bound-only, but not
232 * if it is requesting bpf offload.
233 */
234 if (attr->prog_flags & BPF_F_XDP_HAS_FRAGS &&
235 !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY))
236 return -EINVAL;
237
238 if (attr->prog_type == BPF_PROG_TYPE_SCHED_CLS &&
239 attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY)
240 return -EINVAL;
241
242 netdev = dev_get_by_index(current->nsproxy->net_ns, attr->prog_ifindex);
243 if (!netdev)
244 return -EINVAL;
245
246 err = bpf_dev_offload_check(netdev);
247 if (err)
248 goto out;
249
250 prog->aux->offload_requested = !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY);
251
252 down_write(&bpf_devs_lock);
253 err = __bpf_prog_dev_bound_init(prog, netdev);
254 up_write(&bpf_devs_lock);
255
256out:
257 dev_put(netdev);
258 return err;
259}
260
261int bpf_prog_dev_bound_inherit(struct bpf_prog *new_prog, struct bpf_prog *old_prog)
262{
263 int err;
264
265 if (!bpf_prog_is_dev_bound(old_prog->aux))
266 return 0;
267
268 if (bpf_prog_is_offloaded(old_prog->aux))
269 return -EINVAL;
270
271 new_prog->aux->dev_bound = old_prog->aux->dev_bound;
272 new_prog->aux->offload_requested = old_prog->aux->offload_requested;
273
274 down_write(&bpf_devs_lock);
275 if (!old_prog->aux->offload) {
276 err = -EINVAL;
277 goto out;
278 }
279
280 err = __bpf_prog_dev_bound_init(new_prog, old_prog->aux->offload->netdev);
281
282out:
283 up_write(&bpf_devs_lock);
284 return err;
285}
286
287int bpf_prog_offload_verifier_prep(struct bpf_prog *prog)
288{
289 struct bpf_prog_offload *offload;
290 int ret = -ENODEV;
291
292 down_read(&bpf_devs_lock);
293 offload = prog->aux->offload;
294 if (offload) {
295 ret = offload->offdev->ops->prepare(prog);
296 offload->dev_state = !ret;
297 }
298 up_read(&bpf_devs_lock);
299
300 return ret;
301}
302
303int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
304 int insn_idx, int prev_insn_idx)
305{
306 struct bpf_prog_offload *offload;
307 int ret = -ENODEV;
308
309 down_read(&bpf_devs_lock);
310 offload = env->prog->aux->offload;
311 if (offload)
312 ret = offload->offdev->ops->insn_hook(env, insn_idx,
313 prev_insn_idx);
314 up_read(&bpf_devs_lock);
315
316 return ret;
317}
318
319int bpf_prog_offload_finalize(struct bpf_verifier_env *env)
320{
321 struct bpf_prog_offload *offload;
322 int ret = -ENODEV;
323
324 down_read(&bpf_devs_lock);
325 offload = env->prog->aux->offload;
326 if (offload) {
327 if (offload->offdev->ops->finalize)
328 ret = offload->offdev->ops->finalize(env);
329 else
330 ret = 0;
331 }
332 up_read(&bpf_devs_lock);
333
334 return ret;
335}
336
337void
338bpf_prog_offload_replace_insn(struct bpf_verifier_env *env, u32 off,
339 struct bpf_insn *insn)
340{
341 const struct bpf_prog_offload_ops *ops;
342 struct bpf_prog_offload *offload;
343 int ret = -EOPNOTSUPP;
344
345 down_read(&bpf_devs_lock);
346 offload = env->prog->aux->offload;
347 if (offload) {
348 ops = offload->offdev->ops;
349 if (!offload->opt_failed && ops->replace_insn)
350 ret = ops->replace_insn(env, off, insn);
351 offload->opt_failed |= ret;
352 }
353 up_read(&bpf_devs_lock);
354}
355
356void
357bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt)
358{
359 struct bpf_prog_offload *offload;
360 int ret = -EOPNOTSUPP;
361
362 down_read(&bpf_devs_lock);
363 offload = env->prog->aux->offload;
364 if (offload) {
365 if (!offload->opt_failed && offload->offdev->ops->remove_insns)
366 ret = offload->offdev->ops->remove_insns(env, off, cnt);
367 offload->opt_failed |= ret;
368 }
369 up_read(&bpf_devs_lock);
370}
371
372void bpf_prog_dev_bound_destroy(struct bpf_prog *prog)
373{
374 struct bpf_offload_netdev *ondev;
375 struct net_device *netdev;
376
377 rtnl_lock();
378 down_write(&bpf_devs_lock);
379 if (prog->aux->offload) {
380 list_del_init(&prog->aux->offload->offloads);
381
382 netdev = prog->aux->offload->netdev;
383 __bpf_prog_offload_destroy(prog);
384
385 ondev = bpf_offload_find_netdev(netdev);
386 if (!ondev->offdev && list_empty(&ondev->progs))
387 __bpf_offload_dev_netdev_unregister(NULL, netdev);
388 }
389 up_write(&bpf_devs_lock);
390 rtnl_unlock();
391}
392
393static int bpf_prog_offload_translate(struct bpf_prog *prog)
394{
395 struct bpf_prog_offload *offload;
396 int ret = -ENODEV;
397
398 down_read(&bpf_devs_lock);
399 offload = prog->aux->offload;
400 if (offload)
401 ret = offload->offdev->ops->translate(prog);
402 up_read(&bpf_devs_lock);
403
404 return ret;
405}
406
407static unsigned int bpf_prog_warn_on_exec(const void *ctx,
408 const struct bpf_insn *insn)
409{
410 WARN(1, "attempt to execute device eBPF program on the host!");
411 return 0;
412}
413
414int bpf_prog_offload_compile(struct bpf_prog *prog)
415{
416 prog->bpf_func = bpf_prog_warn_on_exec;
417
418 return bpf_prog_offload_translate(prog);
419}
420
421struct ns_get_path_bpf_prog_args {
422 struct bpf_prog *prog;
423 struct bpf_prog_info *info;
424};
425
426static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
427{
428 struct ns_get_path_bpf_prog_args *args = private_data;
429 struct bpf_prog_aux *aux = args->prog->aux;
430 struct ns_common *ns;
431 struct net *net;
432
433 rtnl_lock();
434 down_read(&bpf_devs_lock);
435
436 if (aux->offload) {
437 args->info->ifindex = aux->offload->netdev->ifindex;
438 net = dev_net(aux->offload->netdev);
439 get_net(net);
440 ns = &net->ns;
441 } else {
442 args->info->ifindex = 0;
443 ns = NULL;
444 }
445
446 up_read(&bpf_devs_lock);
447 rtnl_unlock();
448
449 return ns;
450}
451
452int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
453 struct bpf_prog *prog)
454{
455 struct ns_get_path_bpf_prog_args args = {
456 .prog = prog,
457 .info = info,
458 };
459 struct bpf_prog_aux *aux = prog->aux;
460 struct inode *ns_inode;
461 struct path ns_path;
462 char __user *uinsns;
463 int res;
464 u32 ulen;
465
466 res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
467 if (res) {
468 if (!info->ifindex)
469 return -ENODEV;
470 return res;
471 }
472
473 down_read(&bpf_devs_lock);
474
475 if (!aux->offload) {
476 up_read(&bpf_devs_lock);
477 return -ENODEV;
478 }
479
480 ulen = info->jited_prog_len;
481 info->jited_prog_len = aux->offload->jited_len;
482 if (info->jited_prog_len && ulen) {
483 uinsns = u64_to_user_ptr(info->jited_prog_insns);
484 ulen = min_t(u32, info->jited_prog_len, ulen);
485 if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
486 up_read(&bpf_devs_lock);
487 return -EFAULT;
488 }
489 }
490
491 up_read(&bpf_devs_lock);
492
493 ns_inode = ns_path.dentry->d_inode;
494 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
495 info->netns_ino = ns_inode->i_ino;
496 path_put(&ns_path);
497
498 return 0;
499}
500
501const struct bpf_prog_ops bpf_offload_prog_ops = {
502};
503
504struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
505{
506 struct net *net = current->nsproxy->net_ns;
507 struct bpf_offload_netdev *ondev;
508 struct bpf_offloaded_map *offmap;
509 int err;
510
511 if (!capable(CAP_SYS_ADMIN))
512 return ERR_PTR(-EPERM);
513 if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
514 attr->map_type != BPF_MAP_TYPE_HASH)
515 return ERR_PTR(-EINVAL);
516
517 offmap = bpf_map_area_alloc(sizeof(*offmap), NUMA_NO_NODE);
518 if (!offmap)
519 return ERR_PTR(-ENOMEM);
520
521 bpf_map_init_from_attr(&offmap->map, attr);
522 rtnl_lock();
523 offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
524 err = bpf_dev_offload_check(offmap->netdev);
525 if (err)
526 goto err_unlock_rtnl;
527
528 netdev_lock_ops(offmap->netdev);
529 down_write(&bpf_devs_lock);
530
531 ondev = bpf_offload_find_netdev(offmap->netdev);
532 if (!ondev) {
533 err = -EINVAL;
534 goto err_unlock;
535 }
536
537 err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
538 if (err)
539 goto err_unlock;
540
541 list_add_tail(&offmap->offloads, &ondev->maps);
542 up_write(&bpf_devs_lock);
543 netdev_unlock_ops(offmap->netdev);
544 rtnl_unlock();
545
546 return &offmap->map;
547
548err_unlock:
549 up_write(&bpf_devs_lock);
550 netdev_unlock_ops(offmap->netdev);
551err_unlock_rtnl:
552 rtnl_unlock();
553 bpf_map_area_free(offmap);
554 return ERR_PTR(err);
555}
556
557void bpf_map_offload_map_free(struct bpf_map *map)
558{
559 struct bpf_offloaded_map *offmap = map_to_offmap(map);
560
561 rtnl_lock();
562 down_write(&bpf_devs_lock);
563 if (offmap->netdev)
564 __bpf_map_offload_destroy(offmap);
565 up_write(&bpf_devs_lock);
566 rtnl_unlock();
567
568 bpf_map_area_free(offmap);
569}
570
571u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
572{
573 /* The memory dynamically allocated in netdev dev_ops is not counted */
574 return sizeof(struct bpf_offloaded_map);
575}
576
577int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
578{
579 struct bpf_offloaded_map *offmap = map_to_offmap(map);
580 int ret = -ENODEV;
581
582 down_read(&bpf_devs_lock);
583 if (offmap->netdev)
584 ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
585 up_read(&bpf_devs_lock);
586
587 return ret;
588}
589
590int bpf_map_offload_update_elem(struct bpf_map *map,
591 void *key, void *value, u64 flags)
592{
593 struct bpf_offloaded_map *offmap = map_to_offmap(map);
594 int ret = -ENODEV;
595
596 if (unlikely(flags > BPF_EXIST))
597 return -EINVAL;
598
599 down_read(&bpf_devs_lock);
600 if (offmap->netdev)
601 ret = offmap->dev_ops->map_update_elem(offmap, key, value,
602 flags);
603 up_read(&bpf_devs_lock);
604
605 return ret;
606}
607
608int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
609{
610 struct bpf_offloaded_map *offmap = map_to_offmap(map);
611 int ret = -ENODEV;
612
613 down_read(&bpf_devs_lock);
614 if (offmap->netdev)
615 ret = offmap->dev_ops->map_delete_elem(offmap, key);
616 up_read(&bpf_devs_lock);
617
618 return ret;
619}
620
621int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
622{
623 struct bpf_offloaded_map *offmap = map_to_offmap(map);
624 int ret = -ENODEV;
625
626 down_read(&bpf_devs_lock);
627 if (offmap->netdev)
628 ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
629 up_read(&bpf_devs_lock);
630
631 return ret;
632}
633
634struct ns_get_path_bpf_map_args {
635 struct bpf_offloaded_map *offmap;
636 struct bpf_map_info *info;
637};
638
639static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
640{
641 struct ns_get_path_bpf_map_args *args = private_data;
642 struct ns_common *ns;
643 struct net *net;
644
645 rtnl_lock();
646 down_read(&bpf_devs_lock);
647
648 if (args->offmap->netdev) {
649 args->info->ifindex = args->offmap->netdev->ifindex;
650 net = dev_net(args->offmap->netdev);
651 get_net(net);
652 ns = &net->ns;
653 } else {
654 args->info->ifindex = 0;
655 ns = NULL;
656 }
657
658 up_read(&bpf_devs_lock);
659 rtnl_unlock();
660
661 return ns;
662}
663
664int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
665{
666 struct ns_get_path_bpf_map_args args = {
667 .offmap = map_to_offmap(map),
668 .info = info,
669 };
670 struct inode *ns_inode;
671 struct path ns_path;
672 int res;
673
674 res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
675 if (res) {
676 if (!info->ifindex)
677 return -ENODEV;
678 return res;
679 }
680
681 ns_inode = ns_path.dentry->d_inode;
682 info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
683 info->netns_ino = ns_inode->i_ino;
684 path_put(&ns_path);
685
686 return 0;
687}
688
689static bool __bpf_offload_dev_match(struct bpf_prog *prog,
690 struct net_device *netdev)
691{
692 struct bpf_offload_netdev *ondev1, *ondev2;
693 struct bpf_prog_offload *offload;
694
695 if (!bpf_prog_is_dev_bound(prog->aux))
696 return false;
697
698 offload = prog->aux->offload;
699 if (!offload)
700 return false;
701 if (offload->netdev == netdev)
702 return true;
703
704 ondev1 = bpf_offload_find_netdev(offload->netdev);
705 ondev2 = bpf_offload_find_netdev(netdev);
706
707 return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
708}
709
710bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
711{
712 bool ret;
713
714 down_read(&bpf_devs_lock);
715 ret = __bpf_offload_dev_match(prog, netdev);
716 up_read(&bpf_devs_lock);
717
718 return ret;
719}
720EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
721
722bool bpf_prog_dev_bound_match(const struct bpf_prog *lhs, const struct bpf_prog *rhs)
723{
724 bool ret;
725
726 if (bpf_prog_is_offloaded(lhs->aux) != bpf_prog_is_offloaded(rhs->aux))
727 return false;
728
729 down_read(&bpf_devs_lock);
730 ret = lhs->aux->offload && rhs->aux->offload &&
731 lhs->aux->offload->netdev &&
732 lhs->aux->offload->netdev == rhs->aux->offload->netdev;
733 up_read(&bpf_devs_lock);
734
735 return ret;
736}
737
738bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
739{
740 struct bpf_offloaded_map *offmap;
741 bool ret;
742
743 if (!bpf_map_is_offloaded(map))
744 return bpf_map_offload_neutral(map);
745 offmap = map_to_offmap(map);
746
747 down_read(&bpf_devs_lock);
748 ret = __bpf_offload_dev_match(prog, offmap->netdev);
749 up_read(&bpf_devs_lock);
750
751 return ret;
752}
753
754int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev,
755 struct net_device *netdev)
756{
757 int err;
758
759 down_write(&bpf_devs_lock);
760 err = __bpf_offload_dev_netdev_register(offdev, netdev);
761 up_write(&bpf_devs_lock);
762 return err;
763}
764EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register);
765
766void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev,
767 struct net_device *netdev)
768{
769 down_write(&bpf_devs_lock);
770 __bpf_offload_dev_netdev_unregister(offdev, netdev);
771 up_write(&bpf_devs_lock);
772}
773EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
774
775struct bpf_offload_dev *
776bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv)
777{
778 struct bpf_offload_dev *offdev;
779
780 offdev = kzalloc_obj(*offdev);
781 if (!offdev)
782 return ERR_PTR(-ENOMEM);
783
784 offdev->ops = ops;
785 offdev->priv = priv;
786 INIT_LIST_HEAD(&offdev->netdevs);
787
788 return offdev;
789}
790EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
791
792void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
793{
794 WARN_ON(!list_empty(&offdev->netdevs));
795 kfree(offdev);
796}
797EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);
798
799void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev)
800{
801 return offdev->priv;
802}
803EXPORT_SYMBOL_GPL(bpf_offload_dev_priv);
804
805void bpf_dev_bound_netdev_unregister(struct net_device *dev)
806{
807 struct bpf_offload_netdev *ondev;
808
809 ASSERT_RTNL();
810
811 down_write(&bpf_devs_lock);
812 ondev = bpf_offload_find_netdev(dev);
813 if (ondev && !ondev->offdev)
814 __bpf_offload_dev_netdev_unregister(NULL, ondev->netdev);
815 up_write(&bpf_devs_lock);
816}
817
818int bpf_dev_bound_kfunc_check(struct bpf_verifier_log *log,
819 struct bpf_prog_aux *prog_aux)
820{
821 if (!bpf_prog_is_dev_bound(prog_aux)) {
822 bpf_log(log, "metadata kfuncs require device-bound program\n");
823 return -EINVAL;
824 }
825
826 if (bpf_prog_is_offloaded(prog_aux)) {
827 bpf_log(log, "metadata kfuncs can't be offloaded\n");
828 return -EINVAL;
829 }
830
831 return 0;
832}
833
834void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id)
835{
836 const struct xdp_metadata_ops *ops;
837 void *p = NULL;
838
839 /* We don't hold bpf_devs_lock while resolving several
840 * kfuncs and can race with the unregister_netdevice().
841 * We rely on bpf_dev_bound_match() check at attach
842 * to render this program unusable.
843 */
844 down_read(&bpf_devs_lock);
845 if (!prog->aux->offload)
846 goto out;
847
848 ops = prog->aux->offload->netdev->xdp_metadata_ops;
849 if (!ops)
850 goto out;
851
852#define XDP_METADATA_KFUNC(name, _, __, xmo) \
853 if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo;
854 XDP_METADATA_KFUNC_xxx
855#undef XDP_METADATA_KFUNC
856
857out:
858 up_read(&bpf_devs_lock);
859
860 return p;
861}
862
863static int __init bpf_offload_init(void)
864{
865 return rhashtable_init(&offdevs, &offdevs_params);
866}
867
868core_initcall(bpf_offload_init);